| /* |
| * Copyright (C) 2007 Oracle. All rights reserved. |
| * |
| * This program is free software; you can redistribute it and/or |
| * modify it under the terms of the GNU General Public |
| * License v2 as published by the Free Software Foundation. |
| * |
| * This program is distributed in the hope that it will be useful, |
| * but WITHOUT ANY WARRANTY; without even the implied warranty of |
| * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU |
| * General Public License for more details. |
| * |
| * You should have received a copy of the GNU General Public |
| * License along with this program; if not, write to the |
| * Free Software Foundation, Inc., 59 Temple Place - Suite 330, |
| * Boston, MA 021110-1307, USA. |
| */ |
| #include <linux/sched.h> |
| #include <linux/pagemap.h> |
| #include <linux/writeback.h> |
| #include <linux/blkdev.h> |
| #include <linux/sort.h> |
| #include <linux/rcupdate.h> |
| #include <linux/kthread.h> |
| #include <linux/slab.h> |
| #include <linux/ratelimit.h> |
| #include <linux/percpu_counter.h> |
| #include "hash.h" |
| #include "tree-log.h" |
| #include "disk-io.h" |
| #include "print-tree.h" |
| #include "volumes.h" |
| #include "raid56.h" |
| #include "locking.h" |
| #include "free-space-cache.h" |
| #include "math.h" |
| #include "sysfs.h" |
| #include "qgroup.h" |
| |
| #undef SCRAMBLE_DELAYED_REFS |
| |
| /* |
| * control flags for do_chunk_alloc's force field |
| * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk |
| * if we really need one. |
| * |
| * CHUNK_ALLOC_LIMITED means to only try and allocate one |
| * if we have very few chunks already allocated. This is |
| * used as part of the clustering code to help make sure |
| * we have a good pool of storage to cluster in, without |
| * filling the FS with empty chunks |
| * |
| * CHUNK_ALLOC_FORCE means it must try to allocate one |
| * |
| */ |
| enum { |
| CHUNK_ALLOC_NO_FORCE = 0, |
| CHUNK_ALLOC_LIMITED = 1, |
| CHUNK_ALLOC_FORCE = 2, |
| }; |
| |
| /* |
| * Control how reservations are dealt with. |
| * |
| * RESERVE_FREE - freeing a reservation. |
| * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for |
| * ENOSPC accounting |
| * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update |
| * bytes_may_use as the ENOSPC accounting is done elsewhere |
| */ |
| enum { |
| RESERVE_FREE = 0, |
| RESERVE_ALLOC = 1, |
| RESERVE_ALLOC_NO_ACCOUNT = 2, |
| }; |
| |
| static int update_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr, |
| u64 num_bytes, int alloc); |
| static int __btrfs_free_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, u64 parent, |
| u64 root_objectid, u64 owner_objectid, |
| u64 owner_offset, int refs_to_drop, |
| struct btrfs_delayed_extent_op *extra_op); |
| static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, |
| struct extent_buffer *leaf, |
| struct btrfs_extent_item *ei); |
| static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 parent, u64 root_objectid, |
| u64 flags, u64 owner, u64 offset, |
| struct btrfs_key *ins, int ref_mod); |
| static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 parent, u64 root_objectid, |
| u64 flags, struct btrfs_disk_key *key, |
| int level, struct btrfs_key *ins, |
| int no_quota); |
| static int do_chunk_alloc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *extent_root, u64 flags, |
| int force); |
| static int find_next_key(struct btrfs_path *path, int level, |
| struct btrfs_key *key); |
| static void dump_space_info(struct btrfs_space_info *info, u64 bytes, |
| int dump_block_groups); |
| static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache, |
| u64 num_bytes, int reserve, |
| int delalloc); |
| static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, |
| u64 num_bytes); |
| int btrfs_pin_extent(struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, int reserved); |
| |
| static noinline int |
| block_group_cache_done(struct btrfs_block_group_cache *cache) |
| { |
| smp_mb(); |
| return cache->cached == BTRFS_CACHE_FINISHED || |
| cache->cached == BTRFS_CACHE_ERROR; |
| } |
| |
| static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) |
| { |
| return (cache->flags & bits) == bits; |
| } |
| |
| static void btrfs_get_block_group(struct btrfs_block_group_cache *cache) |
| { |
| atomic_inc(&cache->count); |
| } |
| |
| void btrfs_put_block_group(struct btrfs_block_group_cache *cache) |
| { |
| if (atomic_dec_and_test(&cache->count)) { |
| WARN_ON(cache->pinned > 0); |
| WARN_ON(cache->reserved > 0); |
| kfree(cache->free_space_ctl); |
| kfree(cache); |
| } |
| } |
| |
| /* |
| * this adds the block group to the fs_info rb tree for the block group |
| * cache |
| */ |
| static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct rb_node **p; |
| struct rb_node *parent = NULL; |
| struct btrfs_block_group_cache *cache; |
| |
| spin_lock(&info->block_group_cache_lock); |
| p = &info->block_group_cache_tree.rb_node; |
| |
| while (*p) { |
| parent = *p; |
| cache = rb_entry(parent, struct btrfs_block_group_cache, |
| cache_node); |
| if (block_group->key.objectid < cache->key.objectid) { |
| p = &(*p)->rb_left; |
| } else if (block_group->key.objectid > cache->key.objectid) { |
| p = &(*p)->rb_right; |
| } else { |
| spin_unlock(&info->block_group_cache_lock); |
| return -EEXIST; |
| } |
| } |
| |
| rb_link_node(&block_group->cache_node, parent, p); |
| rb_insert_color(&block_group->cache_node, |
| &info->block_group_cache_tree); |
| |
| if (info->first_logical_byte > block_group->key.objectid) |
| info->first_logical_byte = block_group->key.objectid; |
| |
| spin_unlock(&info->block_group_cache_lock); |
| |
| return 0; |
| } |
| |
| /* |
| * This will return the block group at or after bytenr if contains is 0, else |
| * it will return the block group that contains the bytenr |
| */ |
| static struct btrfs_block_group_cache * |
| block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, |
| int contains) |
| { |
| struct btrfs_block_group_cache *cache, *ret = NULL; |
| struct rb_node *n; |
| u64 end, start; |
| |
| spin_lock(&info->block_group_cache_lock); |
| n = info->block_group_cache_tree.rb_node; |
| |
| while (n) { |
| cache = rb_entry(n, struct btrfs_block_group_cache, |
| cache_node); |
| end = cache->key.objectid + cache->key.offset - 1; |
| start = cache->key.objectid; |
| |
| if (bytenr < start) { |
| if (!contains && (!ret || start < ret->key.objectid)) |
| ret = cache; |
| n = n->rb_left; |
| } else if (bytenr > start) { |
| if (contains && bytenr <= end) { |
| ret = cache; |
| break; |
| } |
| n = n->rb_right; |
| } else { |
| ret = cache; |
| break; |
| } |
| } |
| if (ret) { |
| btrfs_get_block_group(ret); |
| if (bytenr == 0 && info->first_logical_byte > ret->key.objectid) |
| info->first_logical_byte = ret->key.objectid; |
| } |
| spin_unlock(&info->block_group_cache_lock); |
| |
| return ret; |
| } |
| |
| static int add_excluded_extent(struct btrfs_root *root, |
| u64 start, u64 num_bytes) |
| { |
| u64 end = start + num_bytes - 1; |
| set_extent_bits(&root->fs_info->freed_extents[0], |
| start, end, EXTENT_UPTODATE, GFP_NOFS); |
| set_extent_bits(&root->fs_info->freed_extents[1], |
| start, end, EXTENT_UPTODATE, GFP_NOFS); |
| return 0; |
| } |
| |
| static void free_excluded_extents(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache) |
| { |
| u64 start, end; |
| |
| start = cache->key.objectid; |
| end = start + cache->key.offset - 1; |
| |
| clear_extent_bits(&root->fs_info->freed_extents[0], |
| start, end, EXTENT_UPTODATE, GFP_NOFS); |
| clear_extent_bits(&root->fs_info->freed_extents[1], |
| start, end, EXTENT_UPTODATE, GFP_NOFS); |
| } |
| |
| static int exclude_super_stripes(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache) |
| { |
| u64 bytenr; |
| u64 *logical; |
| int stripe_len; |
| int i, nr, ret; |
| |
| if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) { |
| stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid; |
| cache->bytes_super += stripe_len; |
| ret = add_excluded_extent(root, cache->key.objectid, |
| stripe_len); |
| if (ret) |
| return ret; |
| } |
| |
| for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { |
| bytenr = btrfs_sb_offset(i); |
| ret = btrfs_rmap_block(&root->fs_info->mapping_tree, |
| cache->key.objectid, bytenr, |
| 0, &logical, &nr, &stripe_len); |
| if (ret) |
| return ret; |
| |
| while (nr--) { |
| u64 start, len; |
| |
| if (logical[nr] > cache->key.objectid + |
| cache->key.offset) |
| continue; |
| |
| if (logical[nr] + stripe_len <= cache->key.objectid) |
| continue; |
| |
| start = logical[nr]; |
| if (start < cache->key.objectid) { |
| start = cache->key.objectid; |
| len = (logical[nr] + stripe_len) - start; |
| } else { |
| len = min_t(u64, stripe_len, |
| cache->key.objectid + |
| cache->key.offset - start); |
| } |
| |
| cache->bytes_super += len; |
| ret = add_excluded_extent(root, start, len); |
| if (ret) { |
| kfree(logical); |
| return ret; |
| } |
| } |
| |
| kfree(logical); |
| } |
| return 0; |
| } |
| |
| static struct btrfs_caching_control * |
| get_caching_control(struct btrfs_block_group_cache *cache) |
| { |
| struct btrfs_caching_control *ctl; |
| |
| spin_lock(&cache->lock); |
| if (!cache->caching_ctl) { |
| spin_unlock(&cache->lock); |
| return NULL; |
| } |
| |
| ctl = cache->caching_ctl; |
| atomic_inc(&ctl->count); |
| spin_unlock(&cache->lock); |
| return ctl; |
| } |
| |
| static void put_caching_control(struct btrfs_caching_control *ctl) |
| { |
| if (atomic_dec_and_test(&ctl->count)) |
| kfree(ctl); |
| } |
| |
| /* |
| * this is only called by cache_block_group, since we could have freed extents |
| * we need to check the pinned_extents for any extents that can't be used yet |
| * since their free space will be released as soon as the transaction commits. |
| */ |
| static u64 add_new_free_space(struct btrfs_block_group_cache *block_group, |
| struct btrfs_fs_info *info, u64 start, u64 end) |
| { |
| u64 extent_start, extent_end, size, total_added = 0; |
| int ret; |
| |
| while (start < end) { |
| ret = find_first_extent_bit(info->pinned_extents, start, |
| &extent_start, &extent_end, |
| EXTENT_DIRTY | EXTENT_UPTODATE, |
| NULL); |
| if (ret) |
| break; |
| |
| if (extent_start <= start) { |
| start = extent_end + 1; |
| } else if (extent_start > start && extent_start < end) { |
| size = extent_start - start; |
| total_added += size; |
| ret = btrfs_add_free_space(block_group, start, |
| size); |
| BUG_ON(ret); /* -ENOMEM or logic error */ |
| start = extent_end + 1; |
| } else { |
| break; |
| } |
| } |
| |
| if (start < end) { |
| size = end - start; |
| total_added += size; |
| ret = btrfs_add_free_space(block_group, start, size); |
| BUG_ON(ret); /* -ENOMEM or logic error */ |
| } |
| |
| return total_added; |
| } |
| |
| static noinline void caching_thread(struct btrfs_work *work) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_caching_control *caching_ctl; |
| struct btrfs_root *extent_root; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| u64 total_found = 0; |
| u64 last = 0; |
| u32 nritems; |
| int ret = -ENOMEM; |
| |
| caching_ctl = container_of(work, struct btrfs_caching_control, work); |
| block_group = caching_ctl->block_group; |
| fs_info = block_group->fs_info; |
| extent_root = fs_info->extent_root; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| goto out; |
| |
| last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); |
| |
| /* |
| * We don't want to deadlock with somebody trying to allocate a new |
| * extent for the extent root while also trying to search the extent |
| * root to add free space. So we skip locking and search the commit |
| * root, since its read-only |
| */ |
| path->skip_locking = 1; |
| path->search_commit_root = 1; |
| path->reada = 1; |
| |
| key.objectid = last; |
| key.offset = 0; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| again: |
| mutex_lock(&caching_ctl->mutex); |
| /* need to make sure the commit_root doesn't disappear */ |
| down_read(&fs_info->commit_root_sem); |
| |
| next: |
| ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| if (ret < 0) |
| goto err; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| |
| while (1) { |
| if (btrfs_fs_closing(fs_info) > 1) { |
| last = (u64)-1; |
| break; |
| } |
| |
| if (path->slots[0] < nritems) { |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| } else { |
| ret = find_next_key(path, 0, &key); |
| if (ret) |
| break; |
| |
| if (need_resched() || |
| rwsem_is_contended(&fs_info->commit_root_sem)) { |
| caching_ctl->progress = last; |
| btrfs_release_path(path); |
| up_read(&fs_info->commit_root_sem); |
| mutex_unlock(&caching_ctl->mutex); |
| cond_resched(); |
| goto again; |
| } |
| |
| ret = btrfs_next_leaf(extent_root, path); |
| if (ret < 0) |
| goto err; |
| if (ret) |
| break; |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| continue; |
| } |
| |
| if (key.objectid < last) { |
| key.objectid = last; |
| key.offset = 0; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| caching_ctl->progress = last; |
| btrfs_release_path(path); |
| goto next; |
| } |
| |
| if (key.objectid < block_group->key.objectid) { |
| path->slots[0]++; |
| continue; |
| } |
| |
| if (key.objectid >= block_group->key.objectid + |
| block_group->key.offset) |
| break; |
| |
| if (key.type == BTRFS_EXTENT_ITEM_KEY || |
| key.type == BTRFS_METADATA_ITEM_KEY) { |
| total_found += add_new_free_space(block_group, |
| fs_info, last, |
| key.objectid); |
| if (key.type == BTRFS_METADATA_ITEM_KEY) |
| last = key.objectid + |
| fs_info->tree_root->nodesize; |
| else |
| last = key.objectid + key.offset; |
| |
| if (total_found > (1024 * 1024 * 2)) { |
| total_found = 0; |
| wake_up(&caching_ctl->wait); |
| } |
| } |
| path->slots[0]++; |
| } |
| ret = 0; |
| |
| total_found += add_new_free_space(block_group, fs_info, last, |
| block_group->key.objectid + |
| block_group->key.offset); |
| caching_ctl->progress = (u64)-1; |
| |
| spin_lock(&block_group->lock); |
| block_group->caching_ctl = NULL; |
| block_group->cached = BTRFS_CACHE_FINISHED; |
| spin_unlock(&block_group->lock); |
| |
| err: |
| btrfs_free_path(path); |
| up_read(&fs_info->commit_root_sem); |
| |
| free_excluded_extents(extent_root, block_group); |
| |
| mutex_unlock(&caching_ctl->mutex); |
| out: |
| if (ret) { |
| spin_lock(&block_group->lock); |
| block_group->caching_ctl = NULL; |
| block_group->cached = BTRFS_CACHE_ERROR; |
| spin_unlock(&block_group->lock); |
| } |
| wake_up(&caching_ctl->wait); |
| |
| put_caching_control(caching_ctl); |
| btrfs_put_block_group(block_group); |
| } |
| |
| static int cache_block_group(struct btrfs_block_group_cache *cache, |
| int load_cache_only) |
| { |
| DEFINE_WAIT(wait); |
| struct btrfs_fs_info *fs_info = cache->fs_info; |
| struct btrfs_caching_control *caching_ctl; |
| int ret = 0; |
| |
| caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS); |
| if (!caching_ctl) |
| return -ENOMEM; |
| |
| INIT_LIST_HEAD(&caching_ctl->list); |
| mutex_init(&caching_ctl->mutex); |
| init_waitqueue_head(&caching_ctl->wait); |
| caching_ctl->block_group = cache; |
| caching_ctl->progress = cache->key.objectid; |
| atomic_set(&caching_ctl->count, 1); |
| btrfs_init_work(&caching_ctl->work, btrfs_cache_helper, |
| caching_thread, NULL, NULL); |
| |
| spin_lock(&cache->lock); |
| /* |
| * This should be a rare occasion, but this could happen I think in the |
| * case where one thread starts to load the space cache info, and then |
| * some other thread starts a transaction commit which tries to do an |
| * allocation while the other thread is still loading the space cache |
| * info. The previous loop should have kept us from choosing this block |
| * group, but if we've moved to the state where we will wait on caching |
| * block groups we need to first check if we're doing a fast load here, |
| * so we can wait for it to finish, otherwise we could end up allocating |
| * from a block group who's cache gets evicted for one reason or |
| * another. |
| */ |
| while (cache->cached == BTRFS_CACHE_FAST) { |
| struct btrfs_caching_control *ctl; |
| |
| ctl = cache->caching_ctl; |
| atomic_inc(&ctl->count); |
| prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE); |
| spin_unlock(&cache->lock); |
| |
| schedule(); |
| |
| finish_wait(&ctl->wait, &wait); |
| put_caching_control(ctl); |
| spin_lock(&cache->lock); |
| } |
| |
| if (cache->cached != BTRFS_CACHE_NO) { |
| spin_unlock(&cache->lock); |
| kfree(caching_ctl); |
| return 0; |
| } |
| WARN_ON(cache->caching_ctl); |
| cache->caching_ctl = caching_ctl; |
| cache->cached = BTRFS_CACHE_FAST; |
| spin_unlock(&cache->lock); |
| |
| if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) { |
| mutex_lock(&caching_ctl->mutex); |
| ret = load_free_space_cache(fs_info, cache); |
| |
| spin_lock(&cache->lock); |
| if (ret == 1) { |
| cache->caching_ctl = NULL; |
| cache->cached = BTRFS_CACHE_FINISHED; |
| cache->last_byte_to_unpin = (u64)-1; |
| caching_ctl->progress = (u64)-1; |
| } else { |
| if (load_cache_only) { |
| cache->caching_ctl = NULL; |
| cache->cached = BTRFS_CACHE_NO; |
| } else { |
| cache->cached = BTRFS_CACHE_STARTED; |
| cache->has_caching_ctl = 1; |
| } |
| } |
| spin_unlock(&cache->lock); |
| mutex_unlock(&caching_ctl->mutex); |
| |
| wake_up(&caching_ctl->wait); |
| if (ret == 1) { |
| put_caching_control(caching_ctl); |
| free_excluded_extents(fs_info->extent_root, cache); |
| return 0; |
| } |
| } else { |
| /* |
| * We are not going to do the fast caching, set cached to the |
| * appropriate value and wakeup any waiters. |
| */ |
| spin_lock(&cache->lock); |
| if (load_cache_only) { |
| cache->caching_ctl = NULL; |
| cache->cached = BTRFS_CACHE_NO; |
| } else { |
| cache->cached = BTRFS_CACHE_STARTED; |
| cache->has_caching_ctl = 1; |
| } |
| spin_unlock(&cache->lock); |
| wake_up(&caching_ctl->wait); |
| } |
| |
| if (load_cache_only) { |
| put_caching_control(caching_ctl); |
| return 0; |
| } |
| |
| down_write(&fs_info->commit_root_sem); |
| atomic_inc(&caching_ctl->count); |
| list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); |
| up_write(&fs_info->commit_root_sem); |
| |
| btrfs_get_block_group(cache); |
| |
| btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work); |
| |
| return ret; |
| } |
| |
| /* |
| * return the block group that starts at or after bytenr |
| */ |
| static struct btrfs_block_group_cache * |
| btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr) |
| { |
| struct btrfs_block_group_cache *cache; |
| |
| cache = block_group_cache_tree_search(info, bytenr, 0); |
| |
| return cache; |
| } |
| |
| /* |
| * return the block group that contains the given bytenr |
| */ |
| struct btrfs_block_group_cache *btrfs_lookup_block_group( |
| struct btrfs_fs_info *info, |
| u64 bytenr) |
| { |
| struct btrfs_block_group_cache *cache; |
| |
| cache = block_group_cache_tree_search(info, bytenr, 1); |
| |
| return cache; |
| } |
| |
| static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, |
| u64 flags) |
| { |
| struct list_head *head = &info->space_info; |
| struct btrfs_space_info *found; |
| |
| flags &= BTRFS_BLOCK_GROUP_TYPE_MASK; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(found, head, list) { |
| if (found->flags & flags) { |
| rcu_read_unlock(); |
| return found; |
| } |
| } |
| rcu_read_unlock(); |
| return NULL; |
| } |
| |
| /* |
| * after adding space to the filesystem, we need to clear the full flags |
| * on all the space infos. |
| */ |
| void btrfs_clear_space_info_full(struct btrfs_fs_info *info) |
| { |
| struct list_head *head = &info->space_info; |
| struct btrfs_space_info *found; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(found, head, list) |
| found->full = 0; |
| rcu_read_unlock(); |
| } |
| |
| /* simple helper to search for an existing data extent at a given offset */ |
| int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len) |
| { |
| int ret; |
| struct btrfs_key key; |
| struct btrfs_path *path; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| key.objectid = start; |
| key.offset = len; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, |
| 0, 0); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * helper function to lookup reference count and flags of a tree block. |
| * |
| * the head node for delayed ref is used to store the sum of all the |
| * reference count modifications queued up in the rbtree. the head |
| * node may also store the extent flags to set. This way you can check |
| * to see what the reference count and extent flags would be if all of |
| * the delayed refs are not processed. |
| */ |
| int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr, |
| u64 offset, int metadata, u64 *refs, u64 *flags) |
| { |
| struct btrfs_delayed_ref_head *head; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| struct btrfs_path *path; |
| struct btrfs_extent_item *ei; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| u32 item_size; |
| u64 num_refs; |
| u64 extent_flags; |
| int ret; |
| |
| /* |
| * If we don't have skinny metadata, don't bother doing anything |
| * different |
| */ |
| if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) { |
| offset = root->nodesize; |
| metadata = 0; |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| if (!trans) { |
| path->skip_locking = 1; |
| path->search_commit_root = 1; |
| } |
| |
| search_again: |
| key.objectid = bytenr; |
| key.offset = offset; |
| if (metadata) |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| else |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| ret = btrfs_search_slot(trans, root->fs_info->extent_root, |
| &key, path, 0, 0); |
| if (ret < 0) |
| goto out_free; |
| |
| if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) { |
| if (path->slots[0]) { |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| path->slots[0]); |
| if (key.objectid == bytenr && |
| key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == root->nodesize) |
| ret = 0; |
| } |
| } |
| |
| if (ret == 0) { |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| if (item_size >= sizeof(*ei)) { |
| ei = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_item); |
| num_refs = btrfs_extent_refs(leaf, ei); |
| extent_flags = btrfs_extent_flags(leaf, ei); |
| } else { |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| struct btrfs_extent_item_v0 *ei0; |
| BUG_ON(item_size != sizeof(*ei0)); |
| ei0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_item_v0); |
| num_refs = btrfs_extent_refs_v0(leaf, ei0); |
| /* FIXME: this isn't correct for data */ |
| extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| #else |
| BUG(); |
| #endif |
| } |
| BUG_ON(num_refs == 0); |
| } else { |
| num_refs = 0; |
| extent_flags = 0; |
| ret = 0; |
| } |
| |
| if (!trans) |
| goto out; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| spin_lock(&delayed_refs->lock); |
| head = btrfs_find_delayed_ref_head(trans, bytenr); |
| if (head) { |
| if (!mutex_trylock(&head->mutex)) { |
| atomic_inc(&head->node.refs); |
| spin_unlock(&delayed_refs->lock); |
| |
| btrfs_release_path(path); |
| |
| /* |
| * Mutex was contended, block until it's released and try |
| * again |
| */ |
| mutex_lock(&head->mutex); |
| mutex_unlock(&head->mutex); |
| btrfs_put_delayed_ref(&head->node); |
| goto search_again; |
| } |
| spin_lock(&head->lock); |
| if (head->extent_op && head->extent_op->update_flags) |
| extent_flags |= head->extent_op->flags_to_set; |
| else |
| BUG_ON(num_refs == 0); |
| |
| num_refs += head->node.ref_mod; |
| spin_unlock(&head->lock); |
| mutex_unlock(&head->mutex); |
| } |
| spin_unlock(&delayed_refs->lock); |
| out: |
| WARN_ON(num_refs == 0); |
| if (refs) |
| *refs = num_refs; |
| if (flags) |
| *flags = extent_flags; |
| out_free: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * Back reference rules. Back refs have three main goals: |
| * |
| * 1) differentiate between all holders of references to an extent so that |
| * when a reference is dropped we can make sure it was a valid reference |
| * before freeing the extent. |
| * |
| * 2) Provide enough information to quickly find the holders of an extent |
| * if we notice a given block is corrupted or bad. |
| * |
| * 3) Make it easy to migrate blocks for FS shrinking or storage pool |
| * maintenance. This is actually the same as #2, but with a slightly |
| * different use case. |
| * |
| * There are two kinds of back refs. The implicit back refs is optimized |
| * for pointers in non-shared tree blocks. For a given pointer in a block, |
| * back refs of this kind provide information about the block's owner tree |
| * and the pointer's key. These information allow us to find the block by |
| * b-tree searching. The full back refs is for pointers in tree blocks not |
| * referenced by their owner trees. The location of tree block is recorded |
| * in the back refs. Actually the full back refs is generic, and can be |
| * used in all cases the implicit back refs is used. The major shortcoming |
| * of the full back refs is its overhead. Every time a tree block gets |
| * COWed, we have to update back refs entry for all pointers in it. |
| * |
| * For a newly allocated tree block, we use implicit back refs for |
| * pointers in it. This means most tree related operations only involve |
| * implicit back refs. For a tree block created in old transaction, the |
| * only way to drop a reference to it is COW it. So we can detect the |
| * event that tree block loses its owner tree's reference and do the |
| * back refs conversion. |
| * |
| * When a tree block is COW'd through a tree, there are four cases: |
| * |
| * The reference count of the block is one and the tree is the block's |
| * owner tree. Nothing to do in this case. |
| * |
| * The reference count of the block is one and the tree is not the |
| * block's owner tree. In this case, full back refs is used for pointers |
| * in the block. Remove these full back refs, add implicit back refs for |
| * every pointers in the new block. |
| * |
| * The reference count of the block is greater than one and the tree is |
| * the block's owner tree. In this case, implicit back refs is used for |
| * pointers in the block. Add full back refs for every pointers in the |
| * block, increase lower level extents' reference counts. The original |
| * implicit back refs are entailed to the new block. |
| * |
| * The reference count of the block is greater than one and the tree is |
| * not the block's owner tree. Add implicit back refs for every pointer in |
| * the new block, increase lower level extents' reference count. |
| * |
| * Back Reference Key composing: |
| * |
| * The key objectid corresponds to the first byte in the extent, |
| * The key type is used to differentiate between types of back refs. |
| * There are different meanings of the key offset for different types |
| * of back refs. |
| * |
| * File extents can be referenced by: |
| * |
| * - multiple snapshots, subvolumes, or different generations in one subvol |
| * - different files inside a single subvolume |
| * - different offsets inside a file (bookend extents in file.c) |
| * |
| * The extent ref structure for the implicit back refs has fields for: |
| * |
| * - Objectid of the subvolume root |
| * - objectid of the file holding the reference |
| * - original offset in the file |
| * - how many bookend extents |
| * |
| * The key offset for the implicit back refs is hash of the first |
| * three fields. |
| * |
| * The extent ref structure for the full back refs has field for: |
| * |
| * - number of pointers in the tree leaf |
| * |
| * The key offset for the implicit back refs is the first byte of |
| * the tree leaf |
| * |
| * When a file extent is allocated, The implicit back refs is used. |
| * the fields are filled in: |
| * |
| * (root_key.objectid, inode objectid, offset in file, 1) |
| * |
| * When a file extent is removed file truncation, we find the |
| * corresponding implicit back refs and check the following fields: |
| * |
| * (btrfs_header_owner(leaf), inode objectid, offset in file) |
| * |
| * Btree extents can be referenced by: |
| * |
| * - Different subvolumes |
| * |
| * Both the implicit back refs and the full back refs for tree blocks |
| * only consist of key. The key offset for the implicit back refs is |
| * objectid of block's owner tree. The key offset for the full back refs |
| * is the first byte of parent block. |
| * |
| * When implicit back refs is used, information about the lowest key and |
| * level of the tree block are required. These information are stored in |
| * tree block info structure. |
| */ |
| |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| static int convert_extent_item_v0(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 owner, u32 extra_size) |
| { |
| struct btrfs_extent_item *item; |
| struct btrfs_extent_item_v0 *ei0; |
| struct btrfs_extent_ref_v0 *ref0; |
| struct btrfs_tree_block_info *bi; |
| struct extent_buffer *leaf; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| u32 new_size = sizeof(*item); |
| u64 refs; |
| int ret; |
| |
| leaf = path->nodes[0]; |
| BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0)); |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| ei0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_item_v0); |
| refs = btrfs_extent_refs_v0(leaf, ei0); |
| |
| if (owner == (u64)-1) { |
| while (1) { |
| if (path->slots[0] >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret > 0); /* Corruption */ |
| leaf = path->nodes[0]; |
| } |
| btrfs_item_key_to_cpu(leaf, &found_key, |
| path->slots[0]); |
| BUG_ON(key.objectid != found_key.objectid); |
| if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) { |
| path->slots[0]++; |
| continue; |
| } |
| ref0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_ref_v0); |
| owner = btrfs_ref_objectid_v0(leaf, ref0); |
| break; |
| } |
| } |
| btrfs_release_path(path); |
| |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) |
| new_size += sizeof(*bi); |
| |
| new_size -= sizeof(*ei0); |
| ret = btrfs_search_slot(trans, root, &key, path, |
| new_size + extra_size, 1); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret); /* Corruption */ |
| |
| btrfs_extend_item(root, path, new_size); |
| |
| leaf = path->nodes[0]; |
| item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| btrfs_set_extent_refs(leaf, item, refs); |
| /* FIXME: get real generation */ |
| btrfs_set_extent_generation(leaf, item, 0); |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| btrfs_set_extent_flags(leaf, item, |
| BTRFS_EXTENT_FLAG_TREE_BLOCK | |
| BTRFS_BLOCK_FLAG_FULL_BACKREF); |
| bi = (struct btrfs_tree_block_info *)(item + 1); |
| /* FIXME: get first key of the block */ |
| memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi)); |
| btrfs_set_tree_block_level(leaf, bi, (int)owner); |
| } else { |
| btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA); |
| } |
| btrfs_mark_buffer_dirty(leaf); |
| return 0; |
| } |
| #endif |
| |
| static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset) |
| { |
| u32 high_crc = ~(u32)0; |
| u32 low_crc = ~(u32)0; |
| __le64 lenum; |
| |
| lenum = cpu_to_le64(root_objectid); |
| high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum)); |
| lenum = cpu_to_le64(owner); |
| low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); |
| lenum = cpu_to_le64(offset); |
| low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); |
| |
| return ((u64)high_crc << 31) ^ (u64)low_crc; |
| } |
| |
| static u64 hash_extent_data_ref_item(struct extent_buffer *leaf, |
| struct btrfs_extent_data_ref *ref) |
| { |
| return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref), |
| btrfs_extent_data_ref_objectid(leaf, ref), |
| btrfs_extent_data_ref_offset(leaf, ref)); |
| } |
| |
| static int match_extent_data_ref(struct extent_buffer *leaf, |
| struct btrfs_extent_data_ref *ref, |
| u64 root_objectid, u64 owner, u64 offset) |
| { |
| if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid || |
| btrfs_extent_data_ref_objectid(leaf, ref) != owner || |
| btrfs_extent_data_ref_offset(leaf, ref) != offset) |
| return 0; |
| return 1; |
| } |
| |
| static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 parent, |
| u64 root_objectid, |
| u64 owner, u64 offset) |
| { |
| struct btrfs_key key; |
| struct btrfs_extent_data_ref *ref; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| int ret; |
| int recow; |
| int err = -ENOENT; |
| |
| key.objectid = bytenr; |
| if (parent) { |
| key.type = BTRFS_SHARED_DATA_REF_KEY; |
| key.offset = parent; |
| } else { |
| key.type = BTRFS_EXTENT_DATA_REF_KEY; |
| key.offset = hash_extent_data_ref(root_objectid, |
| owner, offset); |
| } |
| again: |
| recow = 0; |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret < 0) { |
| err = ret; |
| goto fail; |
| } |
| |
| if (parent) { |
| if (!ret) |
| return 0; |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| key.type = BTRFS_EXTENT_REF_V0_KEY; |
| btrfs_release_path(path); |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret < 0) { |
| err = ret; |
| goto fail; |
| } |
| if (!ret) |
| return 0; |
| #endif |
| goto fail; |
| } |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| while (1) { |
| if (path->slots[0] >= nritems) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| err = ret; |
| if (ret) |
| goto fail; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| recow = 1; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid != bytenr || |
| key.type != BTRFS_EXTENT_DATA_REF_KEY) |
| goto fail; |
| |
| ref = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_data_ref); |
| |
| if (match_extent_data_ref(leaf, ref, root_objectid, |
| owner, offset)) { |
| if (recow) { |
| btrfs_release_path(path); |
| goto again; |
| } |
| err = 0; |
| break; |
| } |
| path->slots[0]++; |
| } |
| fail: |
| return err; |
| } |
| |
| static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 parent, |
| u64 root_objectid, u64 owner, |
| u64 offset, int refs_to_add) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| u32 size; |
| u32 num_refs; |
| int ret; |
| |
| key.objectid = bytenr; |
| if (parent) { |
| key.type = BTRFS_SHARED_DATA_REF_KEY; |
| key.offset = parent; |
| size = sizeof(struct btrfs_shared_data_ref); |
| } else { |
| key.type = BTRFS_EXTENT_DATA_REF_KEY; |
| key.offset = hash_extent_data_ref(root_objectid, |
| owner, offset); |
| size = sizeof(struct btrfs_extent_data_ref); |
| } |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, size); |
| if (ret && ret != -EEXIST) |
| goto fail; |
| |
| leaf = path->nodes[0]; |
| if (parent) { |
| struct btrfs_shared_data_ref *ref; |
| ref = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_shared_data_ref); |
| if (ret == 0) { |
| btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add); |
| } else { |
| num_refs = btrfs_shared_data_ref_count(leaf, ref); |
| num_refs += refs_to_add; |
| btrfs_set_shared_data_ref_count(leaf, ref, num_refs); |
| } |
| } else { |
| struct btrfs_extent_data_ref *ref; |
| while (ret == -EEXIST) { |
| ref = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_data_ref); |
| if (match_extent_data_ref(leaf, ref, root_objectid, |
| owner, offset)) |
| break; |
| btrfs_release_path(path); |
| key.offset++; |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| size); |
| if (ret && ret != -EEXIST) |
| goto fail; |
| |
| leaf = path->nodes[0]; |
| } |
| ref = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_data_ref); |
| if (ret == 0) { |
| btrfs_set_extent_data_ref_root(leaf, ref, |
| root_objectid); |
| btrfs_set_extent_data_ref_objectid(leaf, ref, owner); |
| btrfs_set_extent_data_ref_offset(leaf, ref, offset); |
| btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add); |
| } else { |
| num_refs = btrfs_extent_data_ref_count(leaf, ref); |
| num_refs += refs_to_add; |
| btrfs_set_extent_data_ref_count(leaf, ref, num_refs); |
| } |
| } |
| btrfs_mark_buffer_dirty(leaf); |
| ret = 0; |
| fail: |
| btrfs_release_path(path); |
| return ret; |
| } |
| |
| static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| int refs_to_drop, int *last_ref) |
| { |
| struct btrfs_key key; |
| struct btrfs_extent_data_ref *ref1 = NULL; |
| struct btrfs_shared_data_ref *ref2 = NULL; |
| struct extent_buffer *leaf; |
| u32 num_refs = 0; |
| int ret = 0; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| |
| if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| ref1 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_data_ref); |
| num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| ref2 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_shared_data_ref); |
| num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| struct btrfs_extent_ref_v0 *ref0; |
| ref0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_ref_v0); |
| num_refs = btrfs_ref_count_v0(leaf, ref0); |
| #endif |
| } else { |
| BUG(); |
| } |
| |
| BUG_ON(num_refs < refs_to_drop); |
| num_refs -= refs_to_drop; |
| |
| if (num_refs == 0) { |
| ret = btrfs_del_item(trans, root, path); |
| *last_ref = 1; |
| } else { |
| if (key.type == BTRFS_EXTENT_DATA_REF_KEY) |
| btrfs_set_extent_data_ref_count(leaf, ref1, num_refs); |
| else if (key.type == BTRFS_SHARED_DATA_REF_KEY) |
| btrfs_set_shared_data_ref_count(leaf, ref2, num_refs); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| else { |
| struct btrfs_extent_ref_v0 *ref0; |
| ref0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_ref_v0); |
| btrfs_set_ref_count_v0(leaf, ref0, num_refs); |
| } |
| #endif |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| return ret; |
| } |
| |
| static noinline u32 extent_data_ref_count(struct btrfs_path *path, |
| struct btrfs_extent_inline_ref *iref) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_data_ref *ref1; |
| struct btrfs_shared_data_ref *ref2; |
| u32 num_refs = 0; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (iref) { |
| if (btrfs_extent_inline_ref_type(leaf, iref) == |
| BTRFS_EXTENT_DATA_REF_KEY) { |
| ref1 = (struct btrfs_extent_data_ref *)(&iref->offset); |
| num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| } else { |
| ref2 = (struct btrfs_shared_data_ref *)(iref + 1); |
| num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| } |
| } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { |
| ref1 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_data_ref); |
| num_refs = btrfs_extent_data_ref_count(leaf, ref1); |
| } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { |
| ref2 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_shared_data_ref); |
| num_refs = btrfs_shared_data_ref_count(leaf, ref2); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) { |
| struct btrfs_extent_ref_v0 *ref0; |
| ref0 = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_ref_v0); |
| num_refs = btrfs_ref_count_v0(leaf, ref0); |
| #endif |
| } else { |
| WARN_ON(1); |
| } |
| return num_refs; |
| } |
| |
| static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 parent, |
| u64 root_objectid) |
| { |
| struct btrfs_key key; |
| int ret; |
| |
| key.objectid = bytenr; |
| if (parent) { |
| key.type = BTRFS_SHARED_BLOCK_REF_KEY; |
| key.offset = parent; |
| } else { |
| key.type = BTRFS_TREE_BLOCK_REF_KEY; |
| key.offset = root_objectid; |
| } |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) |
| ret = -ENOENT; |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (ret == -ENOENT && parent) { |
| btrfs_release_path(path); |
| key.type = BTRFS_EXTENT_REF_V0_KEY; |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) |
| ret = -ENOENT; |
| } |
| #endif |
| return ret; |
| } |
| |
| static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 parent, |
| u64 root_objectid) |
| { |
| struct btrfs_key key; |
| int ret; |
| |
| key.objectid = bytenr; |
| if (parent) { |
| key.type = BTRFS_SHARED_BLOCK_REF_KEY; |
| key.offset = parent; |
| } else { |
| key.type = BTRFS_TREE_BLOCK_REF_KEY; |
| key.offset = root_objectid; |
| } |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, 0); |
| btrfs_release_path(path); |
| return ret; |
| } |
| |
| static inline int extent_ref_type(u64 parent, u64 owner) |
| { |
| int type; |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| if (parent > 0) |
| type = BTRFS_SHARED_BLOCK_REF_KEY; |
| else |
| type = BTRFS_TREE_BLOCK_REF_KEY; |
| } else { |
| if (parent > 0) |
| type = BTRFS_SHARED_DATA_REF_KEY; |
| else |
| type = BTRFS_EXTENT_DATA_REF_KEY; |
| } |
| return type; |
| } |
| |
| static int find_next_key(struct btrfs_path *path, int level, |
| struct btrfs_key *key) |
| |
| { |
| for (; level < BTRFS_MAX_LEVEL; level++) { |
| if (!path->nodes[level]) |
| break; |
| if (path->slots[level] + 1 >= |
| btrfs_header_nritems(path->nodes[level])) |
| continue; |
| if (level == 0) |
| btrfs_item_key_to_cpu(path->nodes[level], key, |
| path->slots[level] + 1); |
| else |
| btrfs_node_key_to_cpu(path->nodes[level], key, |
| path->slots[level] + 1); |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * look for inline back ref. if back ref is found, *ref_ret is set |
| * to the address of inline back ref, and 0 is returned. |
| * |
| * if back ref isn't found, *ref_ret is set to the address where it |
| * should be inserted, and -ENOENT is returned. |
| * |
| * if insert is true and there are too many inline back refs, the path |
| * points to the extent item, and -EAGAIN is returned. |
| * |
| * NOTE: inline back refs are ordered in the same way that back ref |
| * items in the tree are ordered. |
| */ |
| static noinline_for_stack |
| int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_extent_inline_ref **ref_ret, |
| u64 bytenr, u64 num_bytes, |
| u64 parent, u64 root_objectid, |
| u64 owner, u64 offset, int insert) |
| { |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_item *ei; |
| struct btrfs_extent_inline_ref *iref; |
| u64 flags; |
| u64 item_size; |
| unsigned long ptr; |
| unsigned long end; |
| int extra_size; |
| int type; |
| int want; |
| int ret; |
| int err = 0; |
| bool skinny_metadata = btrfs_fs_incompat(root->fs_info, |
| SKINNY_METADATA); |
| |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = num_bytes; |
| |
| want = extent_ref_type(parent, owner); |
| if (insert) { |
| extra_size = btrfs_extent_inline_ref_size(want); |
| path->keep_locks = 1; |
| } else |
| extra_size = -1; |
| |
| /* |
| * Owner is our parent level, so we can just add one to get the level |
| * for the block we are interested in. |
| */ |
| if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) { |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| key.offset = owner; |
| } |
| |
| again: |
| ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| |
| /* |
| * We may be a newly converted file system which still has the old fat |
| * extent entries for metadata, so try and see if we have one of those. |
| */ |
| if (ret > 0 && skinny_metadata) { |
| skinny_metadata = false; |
| if (path->slots[0]) { |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| path->slots[0]); |
| if (key.objectid == bytenr && |
| key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == num_bytes) |
| ret = 0; |
| } |
| if (ret) { |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = num_bytes; |
| btrfs_release_path(path); |
| goto again; |
| } |
| } |
| |
| if (ret && !insert) { |
| err = -ENOENT; |
| goto out; |
| } else if (WARN_ON(ret)) { |
| err = -EIO; |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| if (!insert) { |
| err = -ENOENT; |
| goto out; |
| } |
| ret = convert_extent_item_v0(trans, root, path, owner, |
| extra_size); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| } |
| #endif |
| BUG_ON(item_size < sizeof(*ei)); |
| |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| flags = btrfs_extent_flags(leaf, ei); |
| |
| ptr = (unsigned long)(ei + 1); |
| end = (unsigned long)ei + item_size; |
| |
| if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) { |
| ptr += sizeof(struct btrfs_tree_block_info); |
| BUG_ON(ptr > end); |
| } |
| |
| err = -ENOENT; |
| while (1) { |
| if (ptr >= end) { |
| WARN_ON(ptr > end); |
| break; |
| } |
| iref = (struct btrfs_extent_inline_ref *)ptr; |
| type = btrfs_extent_inline_ref_type(leaf, iref); |
| if (want < type) |
| break; |
| if (want > type) { |
| ptr += btrfs_extent_inline_ref_size(type); |
| continue; |
| } |
| |
| if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| struct btrfs_extent_data_ref *dref; |
| dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| if (match_extent_data_ref(leaf, dref, root_objectid, |
| owner, offset)) { |
| err = 0; |
| break; |
| } |
| if (hash_extent_data_ref_item(leaf, dref) < |
| hash_extent_data_ref(root_objectid, owner, offset)) |
| break; |
| } else { |
| u64 ref_offset; |
| ref_offset = btrfs_extent_inline_ref_offset(leaf, iref); |
| if (parent > 0) { |
| if (parent == ref_offset) { |
| err = 0; |
| break; |
| } |
| if (ref_offset < parent) |
| break; |
| } else { |
| if (root_objectid == ref_offset) { |
| err = 0; |
| break; |
| } |
| if (ref_offset < root_objectid) |
| break; |
| } |
| } |
| ptr += btrfs_extent_inline_ref_size(type); |
| } |
| if (err == -ENOENT && insert) { |
| if (item_size + extra_size >= |
| BTRFS_MAX_EXTENT_ITEM_SIZE(root)) { |
| err = -EAGAIN; |
| goto out; |
| } |
| /* |
| * To add new inline back ref, we have to make sure |
| * there is no corresponding back ref item. |
| * For simplicity, we just do not add new inline back |
| * ref if there is any kind of item for this block |
| */ |
| if (find_next_key(path, 0, &key) == 0 && |
| key.objectid == bytenr && |
| key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| err = -EAGAIN; |
| goto out; |
| } |
| } |
| *ref_ret = (struct btrfs_extent_inline_ref *)ptr; |
| out: |
| if (insert) { |
| path->keep_locks = 0; |
| btrfs_unlock_up_safe(path, 1); |
| } |
| return err; |
| } |
| |
| /* |
| * helper to add new inline back ref |
| */ |
| static noinline_for_stack |
| void setup_inline_extent_backref(struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_extent_inline_ref *iref, |
| u64 parent, u64 root_objectid, |
| u64 owner, u64 offset, int refs_to_add, |
| struct btrfs_delayed_extent_op *extent_op) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_extent_item *ei; |
| unsigned long ptr; |
| unsigned long end; |
| unsigned long item_offset; |
| u64 refs; |
| int size; |
| int type; |
| |
| leaf = path->nodes[0]; |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| item_offset = (unsigned long)iref - (unsigned long)ei; |
| |
| type = extent_ref_type(parent, owner); |
| size = btrfs_extent_inline_ref_size(type); |
| |
| btrfs_extend_item(root, path, size); |
| |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| refs = btrfs_extent_refs(leaf, ei); |
| refs += refs_to_add; |
| btrfs_set_extent_refs(leaf, ei, refs); |
| if (extent_op) |
| __run_delayed_extent_op(extent_op, leaf, ei); |
| |
| ptr = (unsigned long)ei + item_offset; |
| end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]); |
| if (ptr < end - size) |
| memmove_extent_buffer(leaf, ptr + size, ptr, |
| end - size - ptr); |
| |
| iref = (struct btrfs_extent_inline_ref *)ptr; |
| btrfs_set_extent_inline_ref_type(leaf, iref, type); |
| if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| struct btrfs_extent_data_ref *dref; |
| dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| btrfs_set_extent_data_ref_root(leaf, dref, root_objectid); |
| btrfs_set_extent_data_ref_objectid(leaf, dref, owner); |
| btrfs_set_extent_data_ref_offset(leaf, dref, offset); |
| btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add); |
| } else if (type == BTRFS_SHARED_DATA_REF_KEY) { |
| struct btrfs_shared_data_ref *sref; |
| sref = (struct btrfs_shared_data_ref *)(iref + 1); |
| btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add); |
| btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) { |
| btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| } else { |
| btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); |
| } |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| |
| static int lookup_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_extent_inline_ref **ref_ret, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 root_objectid, u64 owner, u64 offset) |
| { |
| int ret; |
| |
| ret = lookup_inline_extent_backref(trans, root, path, ref_ret, |
| bytenr, num_bytes, parent, |
| root_objectid, owner, offset, 0); |
| if (ret != -ENOENT) |
| return ret; |
| |
| btrfs_release_path(path); |
| *ref_ret = NULL; |
| |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| ret = lookup_tree_block_ref(trans, root, path, bytenr, parent, |
| root_objectid); |
| } else { |
| ret = lookup_extent_data_ref(trans, root, path, bytenr, parent, |
| root_objectid, owner, offset); |
| } |
| return ret; |
| } |
| |
| /* |
| * helper to update/remove inline back ref |
| */ |
| static noinline_for_stack |
| void update_inline_extent_backref(struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_extent_inline_ref *iref, |
| int refs_to_mod, |
| struct btrfs_delayed_extent_op *extent_op, |
| int *last_ref) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_extent_item *ei; |
| struct btrfs_extent_data_ref *dref = NULL; |
| struct btrfs_shared_data_ref *sref = NULL; |
| unsigned long ptr; |
| unsigned long end; |
| u32 item_size; |
| int size; |
| int type; |
| u64 refs; |
| |
| leaf = path->nodes[0]; |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| refs = btrfs_extent_refs(leaf, ei); |
| WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0); |
| refs += refs_to_mod; |
| btrfs_set_extent_refs(leaf, ei, refs); |
| if (extent_op) |
| __run_delayed_extent_op(extent_op, leaf, ei); |
| |
| type = btrfs_extent_inline_ref_type(leaf, iref); |
| |
| if (type == BTRFS_EXTENT_DATA_REF_KEY) { |
| dref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| refs = btrfs_extent_data_ref_count(leaf, dref); |
| } else if (type == BTRFS_SHARED_DATA_REF_KEY) { |
| sref = (struct btrfs_shared_data_ref *)(iref + 1); |
| refs = btrfs_shared_data_ref_count(leaf, sref); |
| } else { |
| refs = 1; |
| BUG_ON(refs_to_mod != -1); |
| } |
| |
| BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod); |
| refs += refs_to_mod; |
| |
| if (refs > 0) { |
| if (type == BTRFS_EXTENT_DATA_REF_KEY) |
| btrfs_set_extent_data_ref_count(leaf, dref, refs); |
| else |
| btrfs_set_shared_data_ref_count(leaf, sref, refs); |
| } else { |
| *last_ref = 1; |
| size = btrfs_extent_inline_ref_size(type); |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| ptr = (unsigned long)iref; |
| end = (unsigned long)ei + item_size; |
| if (ptr + size < end) |
| memmove_extent_buffer(leaf, ptr, ptr + size, |
| end - ptr - size); |
| item_size -= size; |
| btrfs_truncate_item(root, path, item_size, 1); |
| } |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| |
| static noinline_for_stack |
| int insert_inline_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 root_objectid, u64 owner, |
| u64 offset, int refs_to_add, |
| struct btrfs_delayed_extent_op *extent_op) |
| { |
| struct btrfs_extent_inline_ref *iref; |
| int ret; |
| |
| ret = lookup_inline_extent_backref(trans, root, path, &iref, |
| bytenr, num_bytes, parent, |
| root_objectid, owner, offset, 1); |
| if (ret == 0) { |
| BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID); |
| update_inline_extent_backref(root, path, iref, |
| refs_to_add, extent_op, NULL); |
| } else if (ret == -ENOENT) { |
| setup_inline_extent_backref(root, path, iref, parent, |
| root_objectid, owner, offset, |
| refs_to_add, extent_op); |
| ret = 0; |
| } |
| return ret; |
| } |
| |
| static int insert_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 bytenr, u64 parent, u64 root_objectid, |
| u64 owner, u64 offset, int refs_to_add) |
| { |
| int ret; |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| BUG_ON(refs_to_add != 1); |
| ret = insert_tree_block_ref(trans, root, path, bytenr, |
| parent, root_objectid); |
| } else { |
| ret = insert_extent_data_ref(trans, root, path, bytenr, |
| parent, root_objectid, |
| owner, offset, refs_to_add); |
| } |
| return ret; |
| } |
| |
| static int remove_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_extent_inline_ref *iref, |
| int refs_to_drop, int is_data, int *last_ref) |
| { |
| int ret = 0; |
| |
| BUG_ON(!is_data && refs_to_drop != 1); |
| if (iref) { |
| update_inline_extent_backref(root, path, iref, |
| -refs_to_drop, NULL, last_ref); |
| } else if (is_data) { |
| ret = remove_extent_data_ref(trans, root, path, refs_to_drop, |
| last_ref); |
| } else { |
| *last_ref = 1; |
| ret = btrfs_del_item(trans, root, path); |
| } |
| return ret; |
| } |
| |
| #define in_range(b, first, len) ((b) >= (first) && (b) < (first) + (len)) |
| static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, |
| u64 *discarded_bytes) |
| { |
| int j, ret = 0; |
| u64 bytes_left, end; |
| u64 aligned_start = ALIGN(start, 1 << 9); |
| |
| if (WARN_ON(start != aligned_start)) { |
| len -= aligned_start - start; |
| len = round_down(len, 1 << 9); |
| start = aligned_start; |
| } |
| |
| *discarded_bytes = 0; |
| |
| if (!len) |
| return 0; |
| |
| end = start + len; |
| bytes_left = len; |
| |
| /* Skip any superblocks on this device. */ |
| for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) { |
| u64 sb_start = btrfs_sb_offset(j); |
| u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE; |
| u64 size = sb_start - start; |
| |
| if (!in_range(sb_start, start, bytes_left) && |
| !in_range(sb_end, start, bytes_left) && |
| !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE)) |
| continue; |
| |
| /* |
| * Superblock spans beginning of range. Adjust start and |
| * try again. |
| */ |
| if (sb_start <= start) { |
| start += sb_end - start; |
| if (start > end) { |
| bytes_left = 0; |
| break; |
| } |
| bytes_left = end - start; |
| continue; |
| } |
| |
| if (size) { |
| ret = blkdev_issue_discard(bdev, start >> 9, size >> 9, |
| GFP_NOFS, 0); |
| if (!ret) |
| *discarded_bytes += size; |
| else if (ret != -EOPNOTSUPP) |
| return ret; |
| } |
| |
| start = sb_end; |
| if (start > end) { |
| bytes_left = 0; |
| break; |
| } |
| bytes_left = end - start; |
| } |
| |
| if (bytes_left) { |
| ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9, |
| GFP_NOFS, 0); |
| if (!ret) |
| *discarded_bytes += bytes_left; |
| } |
| return ret; |
| } |
| |
| int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, |
| u64 num_bytes, u64 *actual_bytes) |
| { |
| int ret; |
| u64 discarded_bytes = 0; |
| struct btrfs_bio *bbio = NULL; |
| |
| |
| /* Tell the block device(s) that the sectors can be discarded */ |
| ret = btrfs_map_block(root->fs_info, REQ_DISCARD, |
| bytenr, &num_bytes, &bbio, 0); |
| /* Error condition is -ENOMEM */ |
| if (!ret) { |
| struct btrfs_bio_stripe *stripe = bbio->stripes; |
| int i; |
| |
| |
| for (i = 0; i < bbio->num_stripes; i++, stripe++) { |
| u64 bytes; |
| if (!stripe->dev->can_discard) |
| continue; |
| |
| ret = btrfs_issue_discard(stripe->dev->bdev, |
| stripe->physical, |
| stripe->length, |
| &bytes); |
| if (!ret) |
| discarded_bytes += bytes; |
| else if (ret != -EOPNOTSUPP) |
| break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */ |
| |
| /* |
| * Just in case we get back EOPNOTSUPP for some reason, |
| * just ignore the return value so we don't screw up |
| * people calling discard_extent. |
| */ |
| ret = 0; |
| } |
| btrfs_put_bbio(bbio); |
| } |
| |
| if (actual_bytes) |
| *actual_bytes = discarded_bytes; |
| |
| |
| if (ret == -EOPNOTSUPP) |
| ret = 0; |
| return ret; |
| } |
| |
| /* Can return -ENOMEM */ |
| int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, u64 parent, |
| u64 root_objectid, u64 owner, u64 offset, |
| int no_quota) |
| { |
| int ret; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID && |
| root_objectid == BTRFS_TREE_LOG_OBJECTID); |
| |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr, |
| num_bytes, |
| parent, root_objectid, (int)owner, |
| BTRFS_ADD_DELAYED_REF, NULL, no_quota); |
| } else { |
| ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, |
| num_bytes, |
| parent, root_objectid, owner, offset, |
| BTRFS_ADD_DELAYED_REF, NULL, no_quota); |
| } |
| return ret; |
| } |
| |
| static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, |
| u64 parent, u64 root_objectid, |
| u64 owner, u64 offset, int refs_to_add, |
| struct btrfs_delayed_extent_op *extent_op) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_item *item; |
| struct btrfs_key key; |
| u64 bytenr = node->bytenr; |
| u64 num_bytes = node->num_bytes; |
| u64 refs; |
| int ret; |
| int no_quota = node->no_quota; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled) |
| no_quota = 1; |
| |
| path->reada = 1; |
| path->leave_spinning = 1; |
| /* this will setup the path even if it fails to insert the back ref */ |
| ret = insert_inline_extent_backref(trans, fs_info->extent_root, path, |
| bytenr, num_bytes, parent, |
| root_objectid, owner, offset, |
| refs_to_add, extent_op); |
| if ((ret < 0 && ret != -EAGAIN) || !ret) |
| goto out; |
| |
| /* |
| * Ok we had -EAGAIN which means we didn't have space to insert and |
| * inline extent ref, so just update the reference count and add a |
| * normal backref. |
| */ |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| refs = btrfs_extent_refs(leaf, item); |
| btrfs_set_extent_refs(leaf, item, refs + refs_to_add); |
| if (extent_op) |
| __run_delayed_extent_op(extent_op, leaf, item); |
| |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_release_path(path); |
| |
| path->reada = 1; |
| path->leave_spinning = 1; |
| /* now insert the actual backref */ |
| ret = insert_extent_backref(trans, root->fs_info->extent_root, |
| path, bytenr, parent, root_objectid, |
| owner, offset, refs_to_add); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| static int run_delayed_data_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, |
| struct btrfs_delayed_extent_op *extent_op, |
| int insert_reserved) |
| { |
| int ret = 0; |
| struct btrfs_delayed_data_ref *ref; |
| struct btrfs_key ins; |
| u64 parent = 0; |
| u64 ref_root = 0; |
| u64 flags = 0; |
| |
| ins.objectid = node->bytenr; |
| ins.offset = node->num_bytes; |
| ins.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| ref = btrfs_delayed_node_to_data_ref(node); |
| trace_run_delayed_data_ref(node, ref, node->action); |
| |
| if (node->type == BTRFS_SHARED_DATA_REF_KEY) |
| parent = ref->parent; |
| ref_root = ref->root; |
| |
| if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { |
| if (extent_op) |
| flags |= extent_op->flags_to_set; |
| ret = alloc_reserved_file_extent(trans, root, |
| parent, ref_root, flags, |
| ref->objectid, ref->offset, |
| &ins, node->ref_mod); |
| } else if (node->action == BTRFS_ADD_DELAYED_REF) { |
| ret = __btrfs_inc_extent_ref(trans, root, node, parent, |
| ref_root, ref->objectid, |
| ref->offset, node->ref_mod, |
| extent_op); |
| } else if (node->action == BTRFS_DROP_DELAYED_REF) { |
| ret = __btrfs_free_extent(trans, root, node, parent, |
| ref_root, ref->objectid, |
| ref->offset, node->ref_mod, |
| extent_op); |
| } else { |
| BUG(); |
| } |
| return ret; |
| } |
| |
| static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, |
| struct extent_buffer *leaf, |
| struct btrfs_extent_item *ei) |
| { |
| u64 flags = btrfs_extent_flags(leaf, ei); |
| if (extent_op->update_flags) { |
| flags |= extent_op->flags_to_set; |
| btrfs_set_extent_flags(leaf, ei, flags); |
| } |
| |
| if (extent_op->update_key) { |
| struct btrfs_tree_block_info *bi; |
| BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| btrfs_set_tree_block_key(leaf, bi, &extent_op->key); |
| } |
| } |
| |
| static int run_delayed_extent_op(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, |
| struct btrfs_delayed_extent_op *extent_op) |
| { |
| struct btrfs_key key; |
| struct btrfs_path *path; |
| struct btrfs_extent_item *ei; |
| struct extent_buffer *leaf; |
| u32 item_size; |
| int ret; |
| int err = 0; |
| int metadata = !extent_op->is_data; |
| |
| if (trans->aborted) |
| return 0; |
| |
| if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) |
| metadata = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| key.objectid = node->bytenr; |
| |
| if (metadata) { |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| key.offset = extent_op->level; |
| } else { |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = node->num_bytes; |
| } |
| |
| again: |
| path->reada = 1; |
| path->leave_spinning = 1; |
| ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, |
| path, 0, 1); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| if (ret > 0) { |
| if (metadata) { |
| if (path->slots[0] > 0) { |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| path->slots[0]); |
| if (key.objectid == node->bytenr && |
| key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == node->num_bytes) |
| ret = 0; |
| } |
| if (ret > 0) { |
| btrfs_release_path(path); |
| metadata = 0; |
| |
| key.objectid = node->bytenr; |
| key.offset = node->num_bytes; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| goto again; |
| } |
| } else { |
| err = -EIO; |
| goto out; |
| } |
| } |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| ret = convert_extent_item_v0(trans, root->fs_info->extent_root, |
| path, (u64)-1, 0); |
| if (ret < 0) { |
| err = ret; |
| goto out; |
| } |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| } |
| #endif |
| BUG_ON(item_size < sizeof(*ei)); |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| __run_delayed_extent_op(extent_op, leaf, ei); |
| |
| btrfs_mark_buffer_dirty(leaf); |
| out: |
| btrfs_free_path(path); |
| return err; |
| } |
| |
| static int run_delayed_tree_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, |
| struct btrfs_delayed_extent_op *extent_op, |
| int insert_reserved) |
| { |
| int ret = 0; |
| struct btrfs_delayed_tree_ref *ref; |
| struct btrfs_key ins; |
| u64 parent = 0; |
| u64 ref_root = 0; |
| bool skinny_metadata = btrfs_fs_incompat(root->fs_info, |
| SKINNY_METADATA); |
| |
| ref = btrfs_delayed_node_to_tree_ref(node); |
| trace_run_delayed_tree_ref(node, ref, node->action); |
| |
| if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) |
| parent = ref->parent; |
| ref_root = ref->root; |
| |
| ins.objectid = node->bytenr; |
| if (skinny_metadata) { |
| ins.offset = ref->level; |
| ins.type = BTRFS_METADATA_ITEM_KEY; |
| } else { |
| ins.offset = node->num_bytes; |
| ins.type = BTRFS_EXTENT_ITEM_KEY; |
| } |
| |
| BUG_ON(node->ref_mod != 1); |
| if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { |
| BUG_ON(!extent_op || !extent_op->update_flags); |
| ret = alloc_reserved_tree_block(trans, root, |
| parent, ref_root, |
| extent_op->flags_to_set, |
| &extent_op->key, |
| ref->level, &ins, |
| node->no_quota); |
| } else if (node->action == BTRFS_ADD_DELAYED_REF) { |
| ret = __btrfs_inc_extent_ref(trans, root, node, |
| parent, ref_root, |
| ref->level, 0, 1, |
| extent_op); |
| } else if (node->action == BTRFS_DROP_DELAYED_REF) { |
| ret = __btrfs_free_extent(trans, root, node, |
| parent, ref_root, |
| ref->level, 0, 1, extent_op); |
| } else { |
| BUG(); |
| } |
| return ret; |
| } |
| |
| /* helper function to actually process a single delayed ref entry */ |
| static int run_one_delayed_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, |
| struct btrfs_delayed_extent_op *extent_op, |
| int insert_reserved) |
| { |
| int ret = 0; |
| |
| if (trans->aborted) { |
| if (insert_reserved) |
| btrfs_pin_extent(root, node->bytenr, |
| node->num_bytes, 1); |
| return 0; |
| } |
| |
| if (btrfs_delayed_ref_is_head(node)) { |
| struct btrfs_delayed_ref_head *head; |
| /* |
| * we've hit the end of the chain and we were supposed |
| * to insert this extent into the tree. But, it got |
| * deleted before we ever needed to insert it, so all |
| * we have to do is clean up the accounting |
| */ |
| BUG_ON(extent_op); |
| head = btrfs_delayed_node_to_head(node); |
| trace_run_delayed_ref_head(node, head, node->action); |
| |
| if (insert_reserved) { |
| btrfs_pin_extent(root, node->bytenr, |
| node->num_bytes, 1); |
| if (head->is_data) { |
| ret = btrfs_del_csums(trans, root, |
| node->bytenr, |
| node->num_bytes); |
| } |
| } |
| return ret; |
| } |
| |
| if (node->type == BTRFS_TREE_BLOCK_REF_KEY || |
| node->type == BTRFS_SHARED_BLOCK_REF_KEY) |
| ret = run_delayed_tree_ref(trans, root, node, extent_op, |
| insert_reserved); |
| else if (node->type == BTRFS_EXTENT_DATA_REF_KEY || |
| node->type == BTRFS_SHARED_DATA_REF_KEY) |
| ret = run_delayed_data_ref(trans, root, node, extent_op, |
| insert_reserved); |
| else |
| BUG(); |
| return ret; |
| } |
| |
| static inline struct btrfs_delayed_ref_node * |
| select_delayed_ref(struct btrfs_delayed_ref_head *head) |
| { |
| struct btrfs_delayed_ref_node *ref; |
| |
| if (list_empty(&head->ref_list)) |
| return NULL; |
| |
| /* |
| * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first. |
| * This is to prevent a ref count from going down to zero, which deletes |
| * the extent item from the extent tree, when there still are references |
| * to add, which would fail because they would not find the extent item. |
| */ |
| list_for_each_entry(ref, &head->ref_list, list) { |
| if (ref->action == BTRFS_ADD_DELAYED_REF) |
| return ref; |
| } |
| |
| return list_entry(head->ref_list.next, struct btrfs_delayed_ref_node, |
| list); |
| } |
| |
| /* |
| * Returns 0 on success or if called with an already aborted transaction. |
| * Returns -ENOMEM or -EIO on failure and will abort the transaction. |
| */ |
| static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| unsigned long nr) |
| { |
| struct btrfs_delayed_ref_root *delayed_refs; |
| struct btrfs_delayed_ref_node *ref; |
| struct btrfs_delayed_ref_head *locked_ref = NULL; |
| struct btrfs_delayed_extent_op *extent_op; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| ktime_t start = ktime_get(); |
| int ret; |
| unsigned long count = 0; |
| unsigned long actual_count = 0; |
| int must_insert_reserved = 0; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| while (1) { |
| if (!locked_ref) { |
| if (count >= nr) |
| break; |
| |
| spin_lock(&delayed_refs->lock); |
| locked_ref = btrfs_select_ref_head(trans); |
| if (!locked_ref) { |
| spin_unlock(&delayed_refs->lock); |
| break; |
| } |
| |
| /* grab the lock that says we are going to process |
| * all the refs for this head */ |
| ret = btrfs_delayed_ref_lock(trans, locked_ref); |
| spin_unlock(&delayed_refs->lock); |
| /* |
| * we may have dropped the spin lock to get the head |
| * mutex lock, and that might have given someone else |
| * time to free the head. If that's true, it has been |
| * removed from our list and we can move on. |
| */ |
| if (ret == -EAGAIN) { |
| locked_ref = NULL; |
| count++; |
| continue; |
| } |
| } |
| |
| spin_lock(&locked_ref->lock); |
| |
| /* |
| * locked_ref is the head node, so we have to go one |
| * node back for any delayed ref updates |
| */ |
| ref = select_delayed_ref(locked_ref); |
| |
| if (ref && ref->seq && |
| btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) { |
| spin_unlock(&locked_ref->lock); |
| btrfs_delayed_ref_unlock(locked_ref); |
| spin_lock(&delayed_refs->lock); |
| locked_ref->processing = 0; |
| delayed_refs->num_heads_ready++; |
| spin_unlock(&delayed_refs->lock); |
| locked_ref = NULL; |
| cond_resched(); |
| count++; |
| continue; |
| } |
| |
| /* |
| * record the must insert reserved flag before we |
| * drop the spin lock. |
| */ |
| must_insert_reserved = locked_ref->must_insert_reserved; |
| locked_ref->must_insert_reserved = 0; |
| |
| extent_op = locked_ref->extent_op; |
| locked_ref->extent_op = NULL; |
| |
| if (!ref) { |
| |
| |
| /* All delayed refs have been processed, Go ahead |
| * and send the head node to run_one_delayed_ref, |
| * so that any accounting fixes can happen |
| */ |
| ref = &locked_ref->node; |
| |
| if (extent_op && must_insert_reserved) { |
| btrfs_free_delayed_extent_op(extent_op); |
| extent_op = NULL; |
| } |
| |
| if (extent_op) { |
| spin_unlock(&locked_ref->lock); |
| ret = run_delayed_extent_op(trans, root, |
| ref, extent_op); |
| btrfs_free_delayed_extent_op(extent_op); |
| |
| if (ret) { |
| /* |
| * Need to reset must_insert_reserved if |
| * there was an error so the abort stuff |
| * can cleanup the reserved space |
| * properly. |
| */ |
| if (must_insert_reserved) |
| locked_ref->must_insert_reserved = 1; |
| locked_ref->processing = 0; |
| btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); |
| btrfs_delayed_ref_unlock(locked_ref); |
| return ret; |
| } |
| continue; |
| } |
| |
| /* |
| * Need to drop our head ref lock and re-aqcuire the |
| * delayed ref lock and then re-check to make sure |
| * nobody got added. |
| */ |
| spin_unlock(&locked_ref->lock); |
| spin_lock(&delayed_refs->lock); |
| spin_lock(&locked_ref->lock); |
| if (!list_empty(&locked_ref->ref_list) || |
| locked_ref->extent_op) { |
| spin_unlock(&locked_ref->lock); |
| spin_unlock(&delayed_refs->lock); |
| continue; |
| } |
| ref->in_tree = 0; |
| delayed_refs->num_heads--; |
| rb_erase(&locked_ref->href_node, |
| &delayed_refs->href_root); |
| spin_unlock(&delayed_refs->lock); |
| } else { |
| actual_count++; |
| ref->in_tree = 0; |
| list_del(&ref->list); |
| } |
| atomic_dec(&delayed_refs->num_entries); |
| |
| if (!btrfs_delayed_ref_is_head(ref)) { |
| /* |
| * when we play the delayed ref, also correct the |
| * ref_mod on head |
| */ |
| switch (ref->action) { |
| case BTRFS_ADD_DELAYED_REF: |
| case BTRFS_ADD_DELAYED_EXTENT: |
| locked_ref->node.ref_mod -= ref->ref_mod; |
| break; |
| case BTRFS_DROP_DELAYED_REF: |
| locked_ref->node.ref_mod += ref->ref_mod; |
| break; |
| default: |
| WARN_ON(1); |
| } |
| } |
| spin_unlock(&locked_ref->lock); |
| |
| ret = run_one_delayed_ref(trans, root, ref, extent_op, |
| must_insert_reserved); |
| |
| btrfs_free_delayed_extent_op(extent_op); |
| if (ret) { |
| locked_ref->processing = 0; |
| btrfs_delayed_ref_unlock(locked_ref); |
| btrfs_put_delayed_ref(ref); |
| btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret); |
| return ret; |
| } |
| |
| /* |
| * If this node is a head, that means all the refs in this head |
| * have been dealt with, and we will pick the next head to deal |
| * with, so we must unlock the head and drop it from the cluster |
| * list before we release it. |
| */ |
| if (btrfs_delayed_ref_is_head(ref)) { |
| if (locked_ref->is_data && |
| locked_ref->total_ref_mod < 0) { |
| spin_lock(&delayed_refs->lock); |
| delayed_refs->pending_csums -= ref->num_bytes; |
| spin_unlock(&delayed_refs->lock); |
| } |
| btrfs_delayed_ref_unlock(locked_ref); |
| locked_ref = NULL; |
| } |
| btrfs_put_delayed_ref(ref); |
| count++; |
| cond_resched(); |
| } |
| |
| /* |
| * We don't want to include ref heads since we can have empty ref heads |
| * and those will drastically skew our runtime down since we just do |
| * accounting, no actual extent tree updates. |
| */ |
| if (actual_count > 0) { |
| u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start)); |
| u64 avg; |
| |
| /* |
| * We weigh the current average higher than our current runtime |
| * to avoid large swings in the average. |
| */ |
| spin_lock(&delayed_refs->lock); |
| avg = fs_info->avg_delayed_ref_runtime * 3 + runtime; |
| fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */ |
| spin_unlock(&delayed_refs->lock); |
| } |
| return 0; |
| } |
| |
| #ifdef SCRAMBLE_DELAYED_REFS |
| /* |
| * Normally delayed refs get processed in ascending bytenr order. This |
| * correlates in most cases to the order added. To expose dependencies on this |
| * order, we start to process the tree in the middle instead of the beginning |
| */ |
| static u64 find_middle(struct rb_root *root) |
| { |
| struct rb_node *n = root->rb_node; |
| struct btrfs_delayed_ref_node *entry; |
| int alt = 1; |
| u64 middle; |
| u64 first = 0, last = 0; |
| |
| n = rb_first(root); |
| if (n) { |
| entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| first = entry->bytenr; |
| } |
| n = rb_last(root); |
| if (n) { |
| entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| last = entry->bytenr; |
| } |
| n = root->rb_node; |
| |
| while (n) { |
| entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); |
| WARN_ON(!entry->in_tree); |
| |
| middle = entry->bytenr; |
| |
| if (alt) |
| n = n->rb_left; |
| else |
| n = n->rb_right; |
| |
| alt = 1 - alt; |
| } |
| return middle; |
| } |
| #endif |
| |
| static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads) |
| { |
| u64 num_bytes; |
| |
| num_bytes = heads * (sizeof(struct btrfs_extent_item) + |
| sizeof(struct btrfs_extent_inline_ref)); |
| if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) |
| num_bytes += heads * sizeof(struct btrfs_tree_block_info); |
| |
| /* |
| * We don't ever fill up leaves all the way so multiply by 2 just to be |
| * closer to what we're really going to want to ouse. |
| */ |
| return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root)); |
| } |
| |
| /* |
| * Takes the number of bytes to be csumm'ed and figures out how many leaves it |
| * would require to store the csums for that many bytes. |
| */ |
| u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes) |
| { |
| u64 csum_size; |
| u64 num_csums_per_leaf; |
| u64 num_csums; |
| |
| csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item); |
| num_csums_per_leaf = div64_u64(csum_size, |
| (u64)btrfs_super_csum_size(root->fs_info->super_copy)); |
| num_csums = div64_u64(csum_bytes, root->sectorsize); |
| num_csums += num_csums_per_leaf - 1; |
| num_csums = div64_u64(num_csums, num_csums_per_leaf); |
| return num_csums; |
| } |
| |
| int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_block_rsv *global_rsv; |
| u64 num_heads = trans->transaction->delayed_refs.num_heads_ready; |
| u64 csum_bytes = trans->transaction->delayed_refs.pending_csums; |
| u64 num_dirty_bgs = trans->transaction->num_dirty_bgs; |
| u64 num_bytes, num_dirty_bgs_bytes; |
| int ret = 0; |
| |
| num_bytes = btrfs_calc_trans_metadata_size(root, 1); |
| num_heads = heads_to_leaves(root, num_heads); |
| if (num_heads > 1) |
| num_bytes += (num_heads - 1) * root->nodesize; |
| num_bytes <<= 1; |
| num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize; |
| num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root, |
| num_dirty_bgs); |
| global_rsv = &root->fs_info->global_block_rsv; |
| |
| /* |
| * If we can't allocate any more chunks lets make sure we have _lots_ of |
| * wiggle room since running delayed refs can create more delayed refs. |
| */ |
| if (global_rsv->space_info->full) { |
| num_dirty_bgs_bytes <<= 1; |
| num_bytes <<= 1; |
| } |
| |
| spin_lock(&global_rsv->lock); |
| if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes) |
| ret = 1; |
| spin_unlock(&global_rsv->lock); |
| return ret; |
| } |
| |
| int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u64 num_entries = |
| atomic_read(&trans->transaction->delayed_refs.num_entries); |
| u64 avg_runtime; |
| u64 val; |
| |
| smp_mb(); |
| avg_runtime = fs_info->avg_delayed_ref_runtime; |
| val = num_entries * avg_runtime; |
| if (num_entries * avg_runtime >= NSEC_PER_SEC) |
| return 1; |
| if (val >= NSEC_PER_SEC / 2) |
| return 2; |
| |
| return btrfs_check_space_for_delayed_refs(trans, root); |
| } |
| |
| struct async_delayed_refs { |
| struct btrfs_root *root; |
| int count; |
| int error; |
| int sync; |
| struct completion wait; |
| struct btrfs_work work; |
| }; |
| |
| static void delayed_ref_async_start(struct btrfs_work *work) |
| { |
| struct async_delayed_refs *async; |
| struct btrfs_trans_handle *trans; |
| int ret; |
| |
| async = container_of(work, struct async_delayed_refs, work); |
| |
| trans = btrfs_join_transaction(async->root); |
| if (IS_ERR(trans)) { |
| async->error = PTR_ERR(trans); |
| goto done; |
| } |
| |
| /* |
| * trans->sync means that when we call end_transaciton, we won't |
| * wait on delayed refs |
| */ |
| trans->sync = true; |
| ret = btrfs_run_delayed_refs(trans, async->root, async->count); |
| if (ret) |
| async->error = ret; |
| |
| ret = btrfs_end_transaction(trans, async->root); |
| if (ret && !async->error) |
| async->error = ret; |
| done: |
| if (async->sync) |
| complete(&async->wait); |
| else |
| kfree(async); |
| } |
| |
| int btrfs_async_run_delayed_refs(struct btrfs_root *root, |
| unsigned long count, int wait) |
| { |
| struct async_delayed_refs *async; |
| int ret; |
| |
| async = kmalloc(sizeof(*async), GFP_NOFS); |
| if (!async) |
| return -ENOMEM; |
| |
| async->root = root->fs_info->tree_root; |
| async->count = count; |
| async->error = 0; |
| if (wait) |
| async->sync = 1; |
| else |
| async->sync = 0; |
| init_completion(&async->wait); |
| |
| btrfs_init_work(&async->work, btrfs_extent_refs_helper, |
| delayed_ref_async_start, NULL, NULL); |
| |
| btrfs_queue_work(root->fs_info->extent_workers, &async->work); |
| |
| if (wait) { |
| wait_for_completion(&async->wait); |
| ret = async->error; |
| kfree(async); |
| return ret; |
| } |
| return 0; |
| } |
| |
| /* |
| * this starts processing the delayed reference count updates and |
| * extent insertions we have queued up so far. count can be |
| * 0, which means to process everything in the tree at the start |
| * of the run (but not newly added entries), or it can be some target |
| * number you'd like to process. |
| * |
| * Returns 0 on success or if called with an aborted transaction |
| * Returns <0 on error and aborts the transaction |
| */ |
| int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, unsigned long count) |
| { |
| struct rb_node *node; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| struct btrfs_delayed_ref_head *head; |
| int ret; |
| int run_all = count == (unsigned long)-1; |
| bool can_flush_pending_bgs = trans->can_flush_pending_bgs; |
| |
| /* We'll clean this up in btrfs_cleanup_transaction */ |
| if (trans->aborted) |
| return 0; |
| |
| if (root == root->fs_info->extent_root) |
| root = root->fs_info->tree_root; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| if (count == 0) |
| count = atomic_read(&delayed_refs->num_entries) * 2; |
| |
| again: |
| #ifdef SCRAMBLE_DELAYED_REFS |
| delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); |
| #endif |
| trans->can_flush_pending_bgs = false; |
| ret = __btrfs_run_delayed_refs(trans, root, count); |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, root, ret); |
| return ret; |
| } |
| |
| if (run_all) { |
| if (!list_empty(&trans->new_bgs)) |
| btrfs_create_pending_block_groups(trans, root); |
| |
| spin_lock(&delayed_refs->lock); |
| node = rb_first(&delayed_refs->href_root); |
| if (!node) { |
| spin_unlock(&delayed_refs->lock); |
| goto out; |
| } |
| count = (unsigned long)-1; |
| |
| while (node) { |
| head = rb_entry(node, struct btrfs_delayed_ref_head, |
| href_node); |
| if (btrfs_delayed_ref_is_head(&head->node)) { |
| struct btrfs_delayed_ref_node *ref; |
| |
| ref = &head->node; |
| atomic_inc(&ref->refs); |
| |
| spin_unlock(&delayed_refs->lock); |
| /* |
| * Mutex was contended, block until it's |
| * released and try again |
| */ |
| mutex_lock(&head->mutex); |
| mutex_unlock(&head->mutex); |
| |
| btrfs_put_delayed_ref(ref); |
| cond_resched(); |
| goto again; |
| } else { |
| WARN_ON(1); |
| } |
| node = rb_next(node); |
| } |
| spin_unlock(&delayed_refs->lock); |
| cond_resched(); |
| goto again; |
| } |
| out: |
| assert_qgroups_uptodate(trans); |
| trans->can_flush_pending_bgs = can_flush_pending_bgs; |
| return 0; |
| } |
| |
| int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, u64 flags, |
| int level, int is_data) |
| { |
| struct btrfs_delayed_extent_op *extent_op; |
| int ret; |
| |
| extent_op = btrfs_alloc_delayed_extent_op(); |
| if (!extent_op) |
| return -ENOMEM; |
| |
| extent_op->flags_to_set = flags; |
| extent_op->update_flags = 1; |
| extent_op->update_key = 0; |
| extent_op->is_data = is_data ? 1 : 0; |
| extent_op->level = level; |
| |
| ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr, |
| num_bytes, extent_op); |
| if (ret) |
| btrfs_free_delayed_extent_op(extent_op); |
| return ret; |
| } |
| |
| static noinline int check_delayed_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 objectid, u64 offset, u64 bytenr) |
| { |
| struct btrfs_delayed_ref_head *head; |
| struct btrfs_delayed_ref_node *ref; |
| struct btrfs_delayed_data_ref *data_ref; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| int ret = 0; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| spin_lock(&delayed_refs->lock); |
| head = btrfs_find_delayed_ref_head(trans, bytenr); |
| if (!head) { |
| spin_unlock(&delayed_refs->lock); |
| return 0; |
| } |
| |
| if (!mutex_trylock(&head->mutex)) { |
| atomic_inc(&head->node.refs); |
| spin_unlock(&delayed_refs->lock); |
| |
| btrfs_release_path(path); |
| |
| /* |
| * Mutex was contended, block until it's released and let |
| * caller try again |
| */ |
| mutex_lock(&head->mutex); |
| mutex_unlock(&head->mutex); |
| btrfs_put_delayed_ref(&head->node); |
| return -EAGAIN; |
| } |
| spin_unlock(&delayed_refs->lock); |
| |
| spin_lock(&head->lock); |
| list_for_each_entry(ref, &head->ref_list, list) { |
| /* If it's a shared ref we know a cross reference exists */ |
| if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) { |
| ret = 1; |
| break; |
| } |
| |
| data_ref = btrfs_delayed_node_to_data_ref(ref); |
| |
| /* |
| * If our ref doesn't match the one we're currently looking at |
| * then we have a cross reference. |
| */ |
| if (data_ref->root != root->root_key.objectid || |
| data_ref->objectid != objectid || |
| data_ref->offset != offset) { |
| ret = 1; |
| break; |
| } |
| } |
| spin_unlock(&head->lock); |
| mutex_unlock(&head->mutex); |
| return ret; |
| } |
| |
| static noinline int check_committed_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u64 objectid, u64 offset, u64 bytenr) |
| { |
| struct btrfs_root *extent_root = root->fs_info->extent_root; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_data_ref *ref; |
| struct btrfs_extent_inline_ref *iref; |
| struct btrfs_extent_item *ei; |
| struct btrfs_key key; |
| u32 item_size; |
| int ret; |
| |
| key.objectid = bytenr; |
| key.offset = (u64)-1; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| BUG_ON(ret == 0); /* Corruption */ |
| |
| ret = -ENOENT; |
| if (path->slots[0] == 0) |
| goto out; |
| |
| path->slots[0]--; |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| |
| if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY) |
| goto out; |
| |
| ret = 1; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); |
| goto out; |
| } |
| #endif |
| ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); |
| |
| if (item_size != sizeof(*ei) + |
| btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY)) |
| goto out; |
| |
| if (btrfs_extent_generation(leaf, ei) <= |
| btrfs_root_last_snapshot(&root->root_item)) |
| goto out; |
| |
| iref = (struct btrfs_extent_inline_ref *)(ei + 1); |
| if (btrfs_extent_inline_ref_type(leaf, iref) != |
| BTRFS_EXTENT_DATA_REF_KEY) |
| goto out; |
| |
| ref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| if (btrfs_extent_refs(leaf, ei) != |
| btrfs_extent_data_ref_count(leaf, ref) || |
| btrfs_extent_data_ref_root(leaf, ref) != |
| root->root_key.objectid || |
| btrfs_extent_data_ref_objectid(leaf, ref) != objectid || |
| btrfs_extent_data_ref_offset(leaf, ref) != offset) |
| goto out; |
| |
| ret = 0; |
| out: |
| return ret; |
| } |
| |
| int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 objectid, u64 offset, u64 bytenr) |
| { |
| struct btrfs_path *path; |
| int ret; |
| int ret2; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOENT; |
| |
| do { |
| ret = check_committed_ref(trans, root, path, objectid, |
| offset, bytenr); |
| if (ret && ret != -ENOENT) |
| goto out; |
| |
| ret2 = check_delayed_ref(trans, root, path, objectid, |
| offset, bytenr); |
| } while (ret2 == -EAGAIN); |
| |
| if (ret2 && ret2 != -ENOENT) { |
| ret = ret2; |
| goto out; |
| } |
| |
| if (ret != -ENOENT || ret2 != -ENOENT) |
| ret = 0; |
| out: |
| btrfs_free_path(path); |
| if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) |
| WARN_ON(ret > 0); |
| return ret; |
| } |
| |
| static int __btrfs_mod_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| int full_backref, int inc) |
| { |
| u64 bytenr; |
| u64 num_bytes; |
| u64 parent; |
| u64 ref_root; |
| u32 nritems; |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| int i; |
| int level; |
| int ret = 0; |
| int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *, |
| u64, u64, u64, u64, u64, u64, int); |
| |
| |
| if (btrfs_test_is_dummy_root(root)) |
| return 0; |
| |
| ref_root = btrfs_header_owner(buf); |
| nritems = btrfs_header_nritems(buf); |
| level = btrfs_header_level(buf); |
| |
| if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0) |
| return 0; |
| |
| if (inc) |
| process_func = btrfs_inc_extent_ref; |
| else |
| process_func = btrfs_free_extent; |
| |
| if (full_backref) |
| parent = buf->start; |
| else |
| parent = 0; |
| |
| for (i = 0; i < nritems; i++) { |
| if (level == 0) { |
| btrfs_item_key_to_cpu(buf, &key, i); |
| if (key.type != BTRFS_EXTENT_DATA_KEY) |
| continue; |
| fi = btrfs_item_ptr(buf, i, |
| struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(buf, fi) == |
| BTRFS_FILE_EXTENT_INLINE) |
| continue; |
| bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| if (bytenr == 0) |
| continue; |
| |
| num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); |
| key.offset -= btrfs_file_extent_offset(buf, fi); |
| ret = process_func(trans, root, bytenr, num_bytes, |
| parent, ref_root, key.objectid, |
| key.offset, 1); |
| if (ret) |
| goto fail; |
| } else { |
| bytenr = btrfs_node_blockptr(buf, i); |
| num_bytes = root->nodesize; |
| ret = process_func(trans, root, bytenr, num_bytes, |
| parent, ref_root, level - 1, 0, |
| 1); |
| if (ret) |
| goto fail; |
| } |
| } |
| return 0; |
| fail: |
| return ret; |
| } |
| |
| int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct extent_buffer *buf, int full_backref) |
| { |
| return __btrfs_mod_ref(trans, root, buf, full_backref, 1); |
| } |
| |
| int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct extent_buffer *buf, int full_backref) |
| { |
| return __btrfs_mod_ref(trans, root, buf, full_backref, 0); |
| } |
| |
| static int write_one_cache_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_block_group_cache *cache) |
| { |
| int ret; |
| struct btrfs_root *extent_root = root->fs_info->extent_root; |
| unsigned long bi; |
| struct extent_buffer *leaf; |
| |
| ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); |
| if (ret) { |
| if (ret > 0) |
| ret = -ENOENT; |
| goto fail; |
| } |
| |
| leaf = path->nodes[0]; |
| bi = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); |
| btrfs_mark_buffer_dirty(leaf); |
| fail: |
| btrfs_release_path(path); |
| return ret; |
| |
| } |
| |
| static struct btrfs_block_group_cache * |
| next_block_group(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache) |
| { |
| struct rb_node *node; |
| |
| spin_lock(&root->fs_info->block_group_cache_lock); |
| |
| /* If our block group was removed, we need a full search. */ |
| if (RB_EMPTY_NODE(&cache->cache_node)) { |
| const u64 next_bytenr = cache->key.objectid + cache->key.offset; |
| |
| spin_unlock(&root->fs_info->block_group_cache_lock); |
| btrfs_put_block_group(cache); |
| cache = btrfs_lookup_first_block_group(root->fs_info, |
| next_bytenr); |
| return cache; |
| } |
| node = rb_next(&cache->cache_node); |
| btrfs_put_block_group(cache); |
| if (node) { |
| cache = rb_entry(node, struct btrfs_block_group_cache, |
| cache_node); |
| btrfs_get_block_group(cache); |
| } else |
| cache = NULL; |
| spin_unlock(&root->fs_info->block_group_cache_lock); |
| return cache; |
| } |
| |
| static int cache_save_setup(struct btrfs_block_group_cache *block_group, |
| struct btrfs_trans_handle *trans, |
| struct btrfs_path *path) |
| { |
| struct btrfs_root *root = block_group->fs_info->tree_root; |
| struct inode *inode = NULL; |
| u64 alloc_hint = 0; |
| int dcs = BTRFS_DC_ERROR; |
| u64 num_pages = 0; |
| int retries = 0; |
| int ret = 0; |
| |
| /* |
| * If this block group is smaller than 100 megs don't bother caching the |
| * block group. |
| */ |
| if (block_group->key.offset < (100 * 1024 * 1024)) { |
| spin_lock(&block_group->lock); |
| block_group->disk_cache_state = BTRFS_DC_WRITTEN; |
| spin_unlock(&block_group->lock); |
| return 0; |
| } |
| |
| if (trans->aborted) |
| return 0; |
| again: |
| inode = lookup_free_space_inode(root, block_group, path); |
| if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { |
| ret = PTR_ERR(inode); |
| btrfs_release_path(path); |
| goto out; |
| } |
| |
| if (IS_ERR(inode)) { |
| BUG_ON(retries); |
| retries++; |
| |
| if (block_group->ro) |
| goto out_free; |
| |
| ret = create_free_space_inode(root, trans, block_group, path); |
| if (ret) |
| goto out_free; |
| goto again; |
| } |
| |
| /* We've already setup this transaction, go ahead and exit */ |
| if (block_group->cache_generation == trans->transid && |
| i_size_read(inode)) { |
| dcs = BTRFS_DC_SETUP; |
| goto out_put; |
| } |
| |
| /* |
| * We want to set the generation to 0, that way if anything goes wrong |
| * from here on out we know not to trust this cache when we load up next |
| * time. |
| */ |
| BTRFS_I(inode)->generation = 0; |
| ret = btrfs_update_inode(trans, root, inode); |
| if (ret) { |
| /* |
| * So theoretically we could recover from this, simply set the |
| * super cache generation to 0 so we know to invalidate the |
| * cache, but then we'd have to keep track of the block groups |
| * that fail this way so we know we _have_ to reset this cache |
| * before the next commit or risk reading stale cache. So to |
| * limit our exposure to horrible edge cases lets just abort the |
| * transaction, this only happens in really bad situations |
| * anyway. |
| */ |
| btrfs_abort_transaction(trans, root, ret); |
| goto out_put; |
| } |
| WARN_ON(ret); |
| |
| if (i_size_read(inode) > 0) { |
| ret = btrfs_check_trunc_cache_free_space(root, |
| &root->fs_info->global_block_rsv); |
| if (ret) |
| goto out_put; |
| |
| ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode); |
| if (ret) |
| goto out_put; |
| } |
| |
| spin_lock(&block_group->lock); |
| if (block_group->cached != BTRFS_CACHE_FINISHED || |
| !btrfs_test_opt(root, SPACE_CACHE)) { |
| /* |
| * don't bother trying to write stuff out _if_ |
| * a) we're not cached, |
| * b) we're with nospace_cache mount option. |
| */ |
| dcs = BTRFS_DC_WRITTEN; |
| spin_unlock(&block_group->lock); |
| goto out_put; |
| } |
| spin_unlock(&block_group->lock); |
| |
| /* |
| * Try to preallocate enough space based on how big the block group is. |
| * Keep in mind this has to include any pinned space which could end up |
| * taking up quite a bit since it's not folded into the other space |
| * cache. |
| */ |
| num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024); |
| if (!num_pages) |
| num_pages = 1; |
| |
| num_pages *= 16; |
| num_pages *= PAGE_CACHE_SIZE; |
| |
| ret = btrfs_check_data_free_space(inode, num_pages, num_pages); |
| if (ret) |
| goto out_put; |
| |
| ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages, |
| num_pages, num_pages, |
| &alloc_hint); |
| if (!ret) |
| dcs = BTRFS_DC_SETUP; |
| btrfs_free_reserved_data_space(inode, num_pages); |
| |
| out_put: |
| iput(inode); |
| out_free: |
| btrfs_release_path(path); |
| out: |
| spin_lock(&block_group->lock); |
| if (!ret && dcs == BTRFS_DC_SETUP) |
| block_group->cache_generation = trans->transid; |
| block_group->disk_cache_state = dcs; |
| spin_unlock(&block_group->lock); |
| |
| return ret; |
| } |
| |
| int btrfs_setup_space_cache(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_block_group_cache *cache, *tmp; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| struct btrfs_path *path; |
| |
| if (list_empty(&cur_trans->dirty_bgs) || |
| !btrfs_test_opt(root, SPACE_CACHE)) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* Could add new block groups, use _safe just in case */ |
| list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs, |
| dirty_list) { |
| if (cache->disk_cache_state == BTRFS_DC_CLEAR) |
| cache_save_setup(cache, trans, path); |
| } |
| |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| /* |
| * transaction commit does final block group cache writeback during a |
| * critical section where nothing is allowed to change the FS. This is |
| * required in order for the cache to actually match the block group, |
| * but can introduce a lot of latency into the commit. |
| * |
| * So, btrfs_start_dirty_block_groups is here to kick off block group |
| * cache IO. There's a chance we'll have to redo some of it if the |
| * block group changes again during the commit, but it greatly reduces |
| * the commit latency by getting rid of the easy block groups while |
| * we're still allowing others to join the commit. |
| */ |
| int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| int ret = 0; |
| int should_put; |
| struct btrfs_path *path = NULL; |
| LIST_HEAD(dirty); |
| struct list_head *io = &cur_trans->io_bgs; |
| int num_started = 0; |
| int loops = 0; |
| |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| if (list_empty(&cur_trans->dirty_bgs)) { |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| return 0; |
| } |
| list_splice_init(&cur_trans->dirty_bgs, &dirty); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| |
| again: |
| /* |
| * make sure all the block groups on our dirty list actually |
| * exist |
| */ |
| btrfs_create_pending_block_groups(trans, root); |
| |
| if (!path) { |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| } |
| |
| /* |
| * cache_write_mutex is here only to save us from balance or automatic |
| * removal of empty block groups deleting this block group while we are |
| * writing out the cache |
| */ |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| while (!list_empty(&dirty)) { |
| cache = list_first_entry(&dirty, |
| struct btrfs_block_group_cache, |
| dirty_list); |
| /* |
| * this can happen if something re-dirties a block |
| * group that is already under IO. Just wait for it to |
| * finish and then do it all again |
| */ |
| if (!list_empty(&cache->io_list)) { |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(root, trans, cache, |
| &cache->io_ctl, path, |
| cache->key.objectid); |
| btrfs_put_block_group(cache); |
| } |
| |
| |
| /* |
| * btrfs_wait_cache_io uses the cache->dirty_list to decide |
| * if it should update the cache_state. Don't delete |
| * until after we wait. |
| * |
| * Since we're not running in the commit critical section |
| * we need the dirty_bgs_lock to protect from update_block_group |
| */ |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| list_del_init(&cache->dirty_list); |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| |
| should_put = 1; |
| |
| cache_save_setup(cache, trans, path); |
| |
| if (cache->disk_cache_state == BTRFS_DC_SETUP) { |
| cache->io_ctl.inode = NULL; |
| ret = btrfs_write_out_cache(root, trans, cache, path); |
| if (ret == 0 && cache->io_ctl.inode) { |
| num_started++; |
| should_put = 0; |
| |
| /* |
| * the cache_write_mutex is protecting |
| * the io_list |
| */ |
| list_add_tail(&cache->io_list, io); |
| } else { |
| /* |
| * if we failed to write the cache, the |
| * generation will be bad and life goes on |
| */ |
| ret = 0; |
| } |
| } |
| if (!ret) { |
| ret = write_one_cache_group(trans, root, path, cache); |
| /* |
| * Our block group might still be attached to the list |
| * of new block groups in the transaction handle of some |
| * other task (struct btrfs_trans_handle->new_bgs). This |
| * means its block group item isn't yet in the extent |
| * tree. If this happens ignore the error, as we will |
| * try again later in the critical section of the |
| * transaction commit. |
| */ |
| if (ret == -ENOENT) { |
| ret = 0; |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| if (list_empty(&cache->dirty_list)) { |
| list_add_tail(&cache->dirty_list, |
| &cur_trans->dirty_bgs); |
| btrfs_get_block_group(cache); |
| } |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| } else if (ret) { |
| btrfs_abort_transaction(trans, root, ret); |
| } |
| } |
| |
| /* if its not on the io list, we need to put the block group */ |
| if (should_put) |
| btrfs_put_block_group(cache); |
| |
| if (ret) |
| break; |
| |
| /* |
| * Avoid blocking other tasks for too long. It might even save |
| * us from writing caches for block groups that are going to be |
| * removed. |
| */ |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| } |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| |
| /* |
| * go through delayed refs for all the stuff we've just kicked off |
| * and then loop back (just once) |
| */ |
| ret = btrfs_run_delayed_refs(trans, root, 0); |
| if (!ret && loops == 0) { |
| loops++; |
| spin_lock(&cur_trans->dirty_bgs_lock); |
| list_splice_init(&cur_trans->dirty_bgs, &dirty); |
| /* |
| * dirty_bgs_lock protects us from concurrent block group |
| * deletes too (not just cache_write_mutex). |
| */ |
| if (!list_empty(&dirty)) { |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| goto again; |
| } |
| spin_unlock(&cur_trans->dirty_bgs_lock); |
| } |
| |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_transaction *cur_trans = trans->transaction; |
| int ret = 0; |
| int should_put; |
| struct btrfs_path *path; |
| struct list_head *io = &cur_trans->io_bgs; |
| int num_started = 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* |
| * We don't need the lock here since we are protected by the transaction |
| * commit. We want to do the cache_save_setup first and then run the |
| * delayed refs to make sure we have the best chance at doing this all |
| * in one shot. |
| */ |
| while (!list_empty(&cur_trans->dirty_bgs)) { |
| cache = list_first_entry(&cur_trans->dirty_bgs, |
| struct btrfs_block_group_cache, |
| dirty_list); |
| |
| /* |
| * this can happen if cache_save_setup re-dirties a block |
| * group that is already under IO. Just wait for it to |
| * finish and then do it all again |
| */ |
| if (!list_empty(&cache->io_list)) { |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(root, trans, cache, |
| &cache->io_ctl, path, |
| cache->key.objectid); |
| btrfs_put_block_group(cache); |
| } |
| |
| /* |
| * don't remove from the dirty list until after we've waited |
| * on any pending IO |
| */ |
| list_del_init(&cache->dirty_list); |
| should_put = 1; |
| |
| cache_save_setup(cache, trans, path); |
| |
| if (!ret) |
| ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1); |
| |
| if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) { |
| cache->io_ctl.inode = NULL; |
| ret = btrfs_write_out_cache(root, trans, cache, path); |
| if (ret == 0 && cache->io_ctl.inode) { |
| num_started++; |
| should_put = 0; |
| list_add_tail(&cache->io_list, io); |
| } else { |
| /* |
| * if we failed to write the cache, the |
| * generation will be bad and life goes on |
| */ |
| ret = 0; |
| } |
| } |
| if (!ret) { |
| ret = write_one_cache_group(trans, root, path, cache); |
| if (ret) |
| btrfs_abort_transaction(trans, root, ret); |
| } |
| |
| /* if its not on the io list, we need to put the block group */ |
| if (should_put) |
| btrfs_put_block_group(cache); |
| } |
| |
| while (!list_empty(io)) { |
| cache = list_first_entry(io, struct btrfs_block_group_cache, |
| io_list); |
| list_del_init(&cache->io_list); |
| btrfs_wait_cache_io(root, trans, cache, |
| &cache->io_ctl, path, cache->key.objectid); |
| btrfs_put_block_group(cache); |
| } |
| |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr) |
| { |
| struct btrfs_block_group_cache *block_group; |
| int readonly = 0; |
| |
| block_group = btrfs_lookup_block_group(root->fs_info, bytenr); |
| if (!block_group || block_group->ro) |
| readonly = 1; |
| if (block_group) |
| btrfs_put_block_group(block_group); |
| return readonly; |
| } |
| |
| static const char *alloc_name(u64 flags) |
| { |
| switch (flags) { |
| case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA: |
| return "mixed"; |
| case BTRFS_BLOCK_GROUP_METADATA: |
| return "metadata"; |
| case BTRFS_BLOCK_GROUP_DATA: |
| return "data"; |
| case BTRFS_BLOCK_GROUP_SYSTEM: |
| return "system"; |
| default: |
| WARN_ON(1); |
| return "invalid-combination"; |
| }; |
| } |
| |
| static int update_space_info(struct btrfs_fs_info *info, u64 flags, |
| u64 total_bytes, u64 bytes_used, |
| struct btrfs_space_info **space_info) |
| { |
| struct btrfs_space_info *found; |
| int i; |
| int factor; |
| int ret; |
| |
| if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| factor = 2; |
| else |
| factor = 1; |
| |
| found = __find_space_info(info, flags); |
| if (found) { |
| spin_lock(&found->lock); |
| found->total_bytes += total_bytes; |
| found->disk_total += total_bytes * factor; |
| found->bytes_used += bytes_used; |
| found->disk_used += bytes_used * factor; |
| if (total_bytes > 0) |
| found->full = 0; |
| spin_unlock(&found->lock); |
| *space_info = found; |
| return 0; |
| } |
| found = kzalloc(sizeof(*found), GFP_NOFS); |
| if (!found) |
| return -ENOMEM; |
| |
| ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL); |
| if (ret) { |
| kfree(found); |
| return ret; |
| } |
| |
| for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) |
| INIT_LIST_HEAD(&found->block_groups[i]); |
| init_rwsem(&found->groups_sem); |
| spin_lock_init(&found->lock); |
| found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; |
| found->total_bytes = total_bytes; |
| found->disk_total = total_bytes * factor; |
| found->bytes_used = bytes_used; |
| found->disk_used = bytes_used * factor; |
| found->bytes_pinned = 0; |
| found->bytes_reserved = 0; |
| found->bytes_readonly = 0; |
| found->bytes_may_use = 0; |
| found->full = 0; |
| found->force_alloc = CHUNK_ALLOC_NO_FORCE; |
| found->chunk_alloc = 0; |
| found->flush = 0; |
| init_waitqueue_head(&found->wait); |
| INIT_LIST_HEAD(&found->ro_bgs); |
| |
| ret = kobject_init_and_add(&found->kobj, &space_info_ktype, |
| info->space_info_kobj, "%s", |
| alloc_name(found->flags)); |
| if (ret) { |
| kfree(found); |
| return ret; |
| } |
| |
| *space_info = found; |
| list_add_rcu(&found->list, &info->space_info); |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| info->data_sinfo = found; |
| |
| return ret; |
| } |
| |
| static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| u64 extra_flags = chunk_to_extended(flags) & |
| BTRFS_EXTENDED_PROFILE_MASK; |
| |
| write_seqlock(&fs_info->profiles_lock); |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| fs_info->avail_data_alloc_bits |= extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| fs_info->avail_metadata_alloc_bits |= extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| fs_info->avail_system_alloc_bits |= extra_flags; |
| write_sequnlock(&fs_info->profiles_lock); |
| } |
| |
| /* |
| * returns target flags in extended format or 0 if restripe for this |
| * chunk_type is not in progress |
| * |
| * should be called with either volume_mutex or balance_lock held |
| */ |
| static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| struct btrfs_balance_control *bctl = fs_info->balance_ctl; |
| u64 target = 0; |
| |
| if (!bctl) |
| return 0; |
| |
| if (flags & BTRFS_BLOCK_GROUP_DATA && |
| bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target; |
| } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM && |
| bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target; |
| } else if (flags & BTRFS_BLOCK_GROUP_METADATA && |
| bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) { |
| target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target; |
| } |
| |
| return target; |
| } |
| |
| /* |
| * @flags: available profiles in extended format (see ctree.h) |
| * |
| * Returns reduced profile in chunk format. If profile changing is in |
| * progress (either running or paused) picks the target profile (if it's |
| * already available), otherwise falls back to plain reducing. |
| */ |
| static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) |
| { |
| u64 num_devices = root->fs_info->fs_devices->rw_devices; |
| u64 target; |
| u64 tmp; |
| |
| /* |
| * see if restripe for this chunk_type is in progress, if so |
| * try to reduce to the target profile |
| */ |
| spin_lock(&root->fs_info->balance_lock); |
| target = get_restripe_target(root->fs_info, flags); |
| if (target) { |
| /* pick target profile only if it's already available */ |
| if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) { |
| spin_unlock(&root->fs_info->balance_lock); |
| return extended_to_chunk(target); |
| } |
| } |
| spin_unlock(&root->fs_info->balance_lock); |
| |
| /* First, mask out the RAID levels which aren't possible */ |
| if (num_devices == 1) |
| flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 | |
| BTRFS_BLOCK_GROUP_RAID5); |
| if (num_devices < 3) |
| flags &= ~BTRFS_BLOCK_GROUP_RAID6; |
| if (num_devices < 4) |
| flags &= ~BTRFS_BLOCK_GROUP_RAID10; |
| |
| tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 | |
| BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 | |
| BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10); |
| flags &= ~tmp; |
| |
| if (tmp & BTRFS_BLOCK_GROUP_RAID6) |
| tmp = BTRFS_BLOCK_GROUP_RAID6; |
| else if (tmp & BTRFS_BLOCK_GROUP_RAID5) |
| tmp = BTRFS_BLOCK_GROUP_RAID5; |
| else if (tmp & BTRFS_BLOCK_GROUP_RAID10) |
| tmp = BTRFS_BLOCK_GROUP_RAID10; |
| else if (tmp & BTRFS_BLOCK_GROUP_RAID1) |
| tmp = BTRFS_BLOCK_GROUP_RAID1; |
| else if (tmp & BTRFS_BLOCK_GROUP_RAID0) |
| tmp = BTRFS_BLOCK_GROUP_RAID0; |
| |
| return extended_to_chunk(flags | tmp); |
| } |
| |
| static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags) |
| { |
| unsigned seq; |
| u64 flags; |
| |
| do { |
| flags = orig_flags; |
| seq = read_seqbegin(&root->fs_info->profiles_lock); |
| |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| flags |= root->fs_info->avail_data_alloc_bits; |
| else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| flags |= root->fs_info->avail_system_alloc_bits; |
| else if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| flags |= root->fs_info->avail_metadata_alloc_bits; |
| } while (read_seqretry(&root->fs_info->profiles_lock, seq)); |
| |
| return btrfs_reduce_alloc_profile(root, flags); |
| } |
| |
| u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data) |
| { |
| u64 flags; |
| u64 ret; |
| |
| if (data) |
| flags = BTRFS_BLOCK_GROUP_DATA; |
| else if (root == root->fs_info->chunk_root) |
| flags = BTRFS_BLOCK_GROUP_SYSTEM; |
| else |
| flags = BTRFS_BLOCK_GROUP_METADATA; |
| |
| ret = get_alloc_profile(root, flags); |
| return ret; |
| } |
| |
| /* |
| * This will check the space that the inode allocates from to make sure we have |
| * enough space for bytes. |
| */ |
| int btrfs_check_data_free_space(struct inode *inode, u64 bytes, u64 write_bytes) |
| { |
| struct btrfs_space_info *data_sinfo; |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| u64 used; |
| int ret = 0; |
| int need_commit = 2; |
| int have_pinned_space; |
| |
| /* make sure bytes are sectorsize aligned */ |
| bytes = ALIGN(bytes, root->sectorsize); |
| |
| if (btrfs_is_free_space_inode(inode)) { |
| need_commit = 0; |
| ASSERT(current->journal_info); |
| } |
| |
| data_sinfo = fs_info->data_sinfo; |
| if (!data_sinfo) |
| goto alloc; |
| |
| again: |
| /* make sure we have enough space to handle the data first */ |
| spin_lock(&data_sinfo->lock); |
| used = data_sinfo->bytes_used + data_sinfo->bytes_reserved + |
| data_sinfo->bytes_pinned + data_sinfo->bytes_readonly + |
| data_sinfo->bytes_may_use; |
| |
| if (used + bytes > data_sinfo->total_bytes) { |
| struct btrfs_trans_handle *trans; |
| |
| /* |
| * if we don't have enough free bytes in this space then we need |
| * to alloc a new chunk. |
| */ |
| if (!data_sinfo->full) { |
| u64 alloc_target; |
| |
| data_sinfo->force_alloc = CHUNK_ALLOC_FORCE; |
| spin_unlock(&data_sinfo->lock); |
| alloc: |
| alloc_target = btrfs_get_alloc_profile(root, 1); |
| /* |
| * It is ugly that we don't call nolock join |
| * transaction for the free space inode case here. |
| * But it is safe because we only do the data space |
| * reservation for the free space cache in the |
| * transaction context, the common join transaction |
| * just increase the counter of the current transaction |
| * handler, doesn't try to acquire the trans_lock of |
| * the fs. |
| */ |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| alloc_target, |
| CHUNK_ALLOC_NO_FORCE); |
| btrfs_end_transaction(trans, root); |
| if (ret < 0) { |
| if (ret != -ENOSPC) |
| return ret; |
| else { |
| have_pinned_space = 1; |
| goto commit_trans; |
| } |
| } |
| |
| if (!data_sinfo) |
| data_sinfo = fs_info->data_sinfo; |
| |
| goto again; |
| } |
| |
| /* |
| * If we don't have enough pinned space to deal with this |
| * allocation, and no removed chunk in current transaction, |
| * don't bother committing the transaction. |
| */ |
| have_pinned_space = percpu_counter_compare( |
| &data_sinfo->total_bytes_pinned, |
| used + bytes - data_sinfo->total_bytes); |
| spin_unlock(&data_sinfo->lock); |
| |
| /* commit the current transaction and try again */ |
| commit_trans: |
| if (need_commit && |
| !atomic_read(&root->fs_info->open_ioctl_trans)) { |
| need_commit--; |
| |
| if (need_commit > 0) |
| btrfs_wait_ordered_roots(fs_info, -1); |
| |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| if (have_pinned_space >= 0 || |
| trans->transaction->have_free_bgs || |
| need_commit > 0) { |
| ret = btrfs_commit_transaction(trans, root); |
| if (ret) |
| return ret; |
| /* |
| * make sure that all running delayed iput are |
| * done |
| */ |
| down_write(&root->fs_info->delayed_iput_sem); |
| up_write(&root->fs_info->delayed_iput_sem); |
| goto again; |
| } else { |
| btrfs_end_transaction(trans, root); |
| } |
| } |
| |
| trace_btrfs_space_reservation(root->fs_info, |
| "space_info:enospc", |
| data_sinfo->flags, bytes, 1); |
| return -ENOSPC; |
| } |
| ret = btrfs_qgroup_reserve(root, write_bytes); |
| if (ret) |
| goto out; |
| data_sinfo->bytes_may_use += bytes; |
| trace_btrfs_space_reservation(root->fs_info, "space_info", |
| data_sinfo->flags, bytes, 1); |
| out: |
| spin_unlock(&data_sinfo->lock); |
| |
| return ret; |
| } |
| |
| /* |
| * Called if we need to clear a data reservation for this inode. |
| */ |
| void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct btrfs_space_info *data_sinfo; |
| |
| /* make sure bytes are sectorsize aligned */ |
| bytes = ALIGN(bytes, root->sectorsize); |
| |
| data_sinfo = root->fs_info->data_sinfo; |
| spin_lock(&data_sinfo->lock); |
| WARN_ON(data_sinfo->bytes_may_use < bytes); |
| data_sinfo->bytes_may_use -= bytes; |
| trace_btrfs_space_reservation(root->fs_info, "space_info", |
| data_sinfo->flags, bytes, 0); |
| spin_unlock(&data_sinfo->lock); |
| } |
| |
| static void force_metadata_allocation(struct btrfs_fs_info *info) |
| { |
| struct list_head *head = &info->space_info; |
| struct btrfs_space_info *found; |
| |
| rcu_read_lock(); |
| list_for_each_entry_rcu(found, head, list) { |
| if (found->flags & BTRFS_BLOCK_GROUP_METADATA) |
| found->force_alloc = CHUNK_ALLOC_FORCE; |
| } |
| rcu_read_unlock(); |
| } |
| |
| static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) |
| { |
| return (global->size << 1); |
| } |
| |
| static int should_alloc_chunk(struct btrfs_root *root, |
| struct btrfs_space_info *sinfo, int force) |
| { |
| struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; |
| u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; |
| u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; |
| u64 thresh; |
| |
| if (force == CHUNK_ALLOC_FORCE) |
| return 1; |
| |
| /* |
| * We need to take into account the global rsv because for all intents |
| * and purposes it's used space. Don't worry about locking the |
| * global_rsv, it doesn't change except when the transaction commits. |
| */ |
| if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA) |
| num_allocated += calc_global_rsv_need_space(global_rsv); |
| |
| /* |
| * in limited mode, we want to have some free space up to |
| * about 1% of the FS size. |
| */ |
| if (force == CHUNK_ALLOC_LIMITED) { |
| thresh = btrfs_super_total_bytes(root->fs_info->super_copy); |
| thresh = max_t(u64, 64 * 1024 * 1024, |
| div_factor_fine(thresh, 1)); |
| |
| if (num_bytes - num_allocated < thresh) |
| return 1; |
| } |
| |
| if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8)) |
| return 0; |
| return 1; |
| } |
| |
| static u64 get_profile_num_devs(struct btrfs_root *root, u64 type) |
| { |
| u64 num_dev; |
| |
| if (type & (BTRFS_BLOCK_GROUP_RAID10 | |
| BTRFS_BLOCK_GROUP_RAID0 | |
| BTRFS_BLOCK_GROUP_RAID5 | |
| BTRFS_BLOCK_GROUP_RAID6)) |
| num_dev = root->fs_info->fs_devices->rw_devices; |
| else if (type & BTRFS_BLOCK_GROUP_RAID1) |
| num_dev = 2; |
| else |
| num_dev = 1; /* DUP or single */ |
| |
| return num_dev; |
| } |
| |
| /* |
| * If @is_allocation is true, reserve space in the system space info necessary |
| * for allocating a chunk, otherwise if it's false, reserve space necessary for |
| * removing a chunk. |
| */ |
| void check_system_chunk(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 type) |
| { |
| struct btrfs_space_info *info; |
| u64 left; |
| u64 thresh; |
| int ret = 0; |
| u64 num_devs; |
| |
| /* |
| * Needed because we can end up allocating a system chunk and for an |
| * atomic and race free space reservation in the chunk block reserve. |
| */ |
| ASSERT(mutex_is_locked(&root->fs_info->chunk_mutex)); |
| |
| info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM); |
| spin_lock(&info->lock); |
| left = info->total_bytes - info->bytes_used - info->bytes_pinned - |
| info->bytes_reserved - info->bytes_readonly - |
| info->bytes_may_use; |
| spin_unlock(&info->lock); |
| |
| num_devs = get_profile_num_devs(root, type); |
| |
| /* num_devs device items to update and 1 chunk item to add or remove */ |
| thresh = btrfs_calc_trunc_metadata_size(root, num_devs) + |
| btrfs_calc_trans_metadata_size(root, 1); |
| |
| if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) { |
| btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu", |
| left, thresh, type); |
| dump_space_info(info, 0, 0); |
| } |
| |
| if (left < thresh) { |
| u64 flags; |
| |
| flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0); |
| /* |
| * Ignore failure to create system chunk. We might end up not |
| * needing it, as we might not need to COW all nodes/leafs from |
| * the paths we visit in the chunk tree (they were already COWed |
| * or created in the current transaction for example). |
| */ |
| ret = btrfs_alloc_chunk(trans, root, flags); |
| } |
| |
| if (!ret) { |
| ret = btrfs_block_rsv_add(root->fs_info->chunk_root, |
| &root->fs_info->chunk_block_rsv, |
| thresh, BTRFS_RESERVE_NO_FLUSH); |
| if (!ret) |
| trans->chunk_bytes_reserved += thresh; |
| } |
| } |
| |
| static int do_chunk_alloc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *extent_root, u64 flags, int force) |
| { |
| struct btrfs_space_info *space_info; |
| struct btrfs_fs_info *fs_info = extent_root->fs_info; |
| int wait_for_alloc = 0; |
| int ret = 0; |
| |
| /* Don't re-enter if we're already allocating a chunk */ |
| if (trans->allocating_chunk) |
| return -ENOSPC; |
| |
| space_info = __find_space_info(extent_root->fs_info, flags); |
| if (!space_info) { |
| ret = update_space_info(extent_root->fs_info, flags, |
| 0, 0, &space_info); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| BUG_ON(!space_info); /* Logic error */ |
| |
| again: |
| spin_lock(&space_info->lock); |
| if (force < space_info->force_alloc) |
| force = space_info->force_alloc; |
| if (space_info->full) { |
| if (should_alloc_chunk(extent_root, space_info, force)) |
| ret = -ENOSPC; |
| else |
| ret = 0; |
| spin_unlock(&space_info->lock); |
| return ret; |
| } |
| |
| if (!should_alloc_chunk(extent_root, space_info, force)) { |
| spin_unlock(&space_info->lock); |
| return 0; |
| } else if (space_info->chunk_alloc) { |
| wait_for_alloc = 1; |
| } else { |
| space_info->chunk_alloc = 1; |
| } |
| |
| spin_unlock(&space_info->lock); |
| |
| mutex_lock(&fs_info->chunk_mutex); |
| |
| /* |
| * The chunk_mutex is held throughout the entirety of a chunk |
| * allocation, so once we've acquired the chunk_mutex we know that the |
| * other guy is done and we need to recheck and see if we should |
| * allocate. |
| */ |
| if (wait_for_alloc) { |
| mutex_unlock(&fs_info->chunk_mutex); |
| wait_for_alloc = 0; |
| goto again; |
| } |
| |
| trans->allocating_chunk = true; |
| |
| /* |
| * If we have mixed data/metadata chunks we want to make sure we keep |
| * allocating mixed chunks instead of individual chunks. |
| */ |
| if (btrfs_mixed_space_info(space_info)) |
| flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA); |
| |
| /* |
| * if we're doing a data chunk, go ahead and make sure that |
| * we keep a reasonable number of metadata chunks allocated in the |
| * FS as well. |
| */ |
| if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) { |
| fs_info->data_chunk_allocations++; |
| if (!(fs_info->data_chunk_allocations % |
| fs_info->metadata_ratio)) |
| force_metadata_allocation(fs_info); |
| } |
| |
| /* |
| * Check if we have enough space in SYSTEM chunk because we may need |
| * to update devices. |
| */ |
| check_system_chunk(trans, extent_root, flags); |
| |
| ret = btrfs_alloc_chunk(trans, extent_root, flags); |
| trans->allocating_chunk = false; |
| |
| spin_lock(&space_info->lock); |
| if (ret < 0 && ret != -ENOSPC) |
| goto out; |
| if (ret) |
| space_info->full = 1; |
| else |
| ret = 1; |
| |
| space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; |
| out: |
| space_info->chunk_alloc = 0; |
| spin_unlock(&space_info->lock); |
| mutex_unlock(&fs_info->chunk_mutex); |
| /* |
| * When we allocate a new chunk we reserve space in the chunk block |
| * reserve to make sure we can COW nodes/leafs in the chunk tree or |
| * add new nodes/leafs to it if we end up needing to do it when |
| * inserting the chunk item and updating device items as part of the |
| * second phase of chunk allocation, performed by |
| * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a |
| * large number of new block groups to create in our transaction |
| * handle's new_bgs list to avoid exhausting the chunk block reserve |
| * in extreme cases - like having a single transaction create many new |
| * block groups when starting to write out the free space caches of all |
| * the block groups that were made dirty during the lifetime of the |
| * transaction. |
| */ |
| if (trans->can_flush_pending_bgs && |
| trans->chunk_bytes_reserved >= (2 * 1024 * 1024ull)) { |
| btrfs_create_pending_block_groups(trans, trans->root); |
| btrfs_trans_release_chunk_metadata(trans); |
| } |
| return ret; |
| } |
| |
| static int can_overcommit(struct btrfs_root *root, |
| struct btrfs_space_info *space_info, u64 bytes, |
| enum btrfs_reserve_flush_enum flush) |
| { |
| struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; |
| u64 profile = btrfs_get_alloc_profile(root, 0); |
| u64 space_size; |
| u64 avail; |
| u64 used; |
| |
| used = space_info->bytes_used + space_info->bytes_reserved + |
| space_info->bytes_pinned + space_info->bytes_readonly; |
| |
| /* |
| * We only want to allow over committing if we have lots of actual space |
| * free, but if we don't have enough space to handle the global reserve |
| * space then we could end up having a real enospc problem when trying |
| * to allocate a chunk or some other such important allocation. |
| */ |
| spin_lock(&global_rsv->lock); |
| space_size = calc_global_rsv_need_space(global_rsv); |
| spin_unlock(&global_rsv->lock); |
| if (used + space_size >= space_info->total_bytes) |
| return 0; |
| |
| used += space_info->bytes_may_use; |
| |
| spin_lock(&root->fs_info->free_chunk_lock); |
| avail = root->fs_info->free_chunk_space; |
| spin_unlock(&root->fs_info->free_chunk_lock); |
| |
| /* |
| * If we have dup, raid1 or raid10 then only half of the free |
| * space is actually useable. For raid56, the space info used |
| * doesn't include the parity drive, so we don't have to |
| * change the math |
| */ |
| if (profile & (BTRFS_BLOCK_GROUP_DUP | |
| BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| avail >>= 1; |
| |
| /* |
| * If we aren't flushing all things, let us overcommit up to |
| * 1/2th of the space. If we can flush, don't let us overcommit |
| * too much, let it overcommit up to 1/8 of the space. |
| */ |
| if (flush == BTRFS_RESERVE_FLUSH_ALL) |
| avail >>= 3; |
| else |
| avail >>= 1; |
| |
| if (used + bytes < space_info->total_bytes + avail) |
| return 1; |
| return 0; |
| } |
| |
| static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root, |
| unsigned long nr_pages, int nr_items) |
| { |
| struct super_block *sb = root->fs_info->sb; |
| |
| if (down_read_trylock(&sb->s_umount)) { |
| writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE); |
| up_read(&sb->s_umount); |
| } else { |
| /* |
| * We needn't worry the filesystem going from r/w to r/o though |
| * we don't acquire ->s_umount mutex, because the filesystem |
| * should guarantee the delalloc inodes list be empty after |
| * the filesystem is readonly(all dirty pages are written to |
| * the disk). |
| */ |
| btrfs_start_delalloc_roots(root->fs_info, 0, nr_items); |
| if (!current->journal_info) |
| btrfs_wait_ordered_roots(root->fs_info, nr_items); |
| } |
| } |
| |
| static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim) |
| { |
| u64 bytes; |
| int nr; |
| |
| bytes = btrfs_calc_trans_metadata_size(root, 1); |
| nr = (int)div64_u64(to_reclaim, bytes); |
| if (!nr) |
| nr = 1; |
| return nr; |
| } |
| |
| #define EXTENT_SIZE_PER_ITEM (256 * 1024) |
| |
| /* |
| * shrink metadata reservation for delalloc |
| */ |
| static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, |
| bool wait_ordered) |
| { |
| struct btrfs_block_rsv *block_rsv; |
| struct btrfs_space_info *space_info; |
| struct btrfs_trans_handle *trans; |
| u64 delalloc_bytes; |
| u64 max_reclaim; |
| long time_left; |
| unsigned long nr_pages; |
| int loops; |
| int items; |
| enum btrfs_reserve_flush_enum flush; |
| |
| /* Calc the number of the pages we need flush for space reservation */ |
| items = calc_reclaim_items_nr(root, to_reclaim); |
| to_reclaim = items * EXTENT_SIZE_PER_ITEM; |
| |
| trans = (struct btrfs_trans_handle *)current->journal_info; |
| block_rsv = &root->fs_info->delalloc_block_rsv; |
| space_info = block_rsv->space_info; |
| |
| delalloc_bytes = percpu_counter_sum_positive( |
| &root->fs_info->delalloc_bytes); |
| if (delalloc_bytes == 0) { |
| if (trans) |
| return; |
| if (wait_ordered) |
| btrfs_wait_ordered_roots(root->fs_info, items); |
| return; |
| } |
| |
| loops = 0; |
| while (delalloc_bytes && loops < 3) { |
| max_reclaim = min(delalloc_bytes, to_reclaim); |
| nr_pages = max_reclaim >> PAGE_CACHE_SHIFT; |
| btrfs_writeback_inodes_sb_nr(root, nr_pages, items); |
| /* |
| * We need to wait for the async pages to actually start before |
| * we do anything. |
| */ |
| max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages); |
| if (!max_reclaim) |
| goto skip_async; |
| |
| if (max_reclaim <= nr_pages) |
| max_reclaim = 0; |
| else |
| max_reclaim -= nr_pages; |
| |
| wait_event(root->fs_info->async_submit_wait, |
| atomic_read(&root->fs_info->async_delalloc_pages) <= |
| (int)max_reclaim); |
| skip_async: |
| if (!trans) |
| flush = BTRFS_RESERVE_FLUSH_ALL; |
| else |
| flush = BTRFS_RESERVE_NO_FLUSH; |
| spin_lock(&space_info->lock); |
| if (can_overcommit(root, space_info, orig, flush)) { |
| spin_unlock(&space_info->lock); |
| break; |
| } |
| spin_unlock(&space_info->lock); |
| |
| loops++; |
| if (wait_ordered && !trans) { |
| btrfs_wait_ordered_roots(root->fs_info, items); |
| } else { |
| time_left = schedule_timeout_killable(1); |
| if (time_left) |
| break; |
| } |
| delalloc_bytes = percpu_counter_sum_positive( |
| &root->fs_info->delalloc_bytes); |
| } |
| } |
| |
| /** |
| * maybe_commit_transaction - possibly commit the transaction if its ok to |
| * @root - the root we're allocating for |
| * @bytes - the number of bytes we want to reserve |
| * @force - force the commit |
| * |
| * This will check to make sure that committing the transaction will actually |
| * get us somewhere and then commit the transaction if it does. Otherwise it |
| * will return -ENOSPC. |
| */ |
| static int may_commit_transaction(struct btrfs_root *root, |
| struct btrfs_space_info *space_info, |
| u64 bytes, int force) |
| { |
| struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv; |
| struct btrfs_trans_handle *trans; |
| |
| trans = (struct btrfs_trans_handle *)current->journal_info; |
| if (trans) |
| return -EAGAIN; |
| |
| if (force) |
| goto commit; |
| |
| /* See if there is enough pinned space to make this reservation */ |
| if (percpu_counter_compare(&space_info->total_bytes_pinned, |
| bytes) >= 0) |
| goto commit; |
| |
| /* |
| * See if there is some space in the delayed insertion reservation for |
| * this reservation. |
| */ |
| if (space_info != delayed_rsv->space_info) |
| return -ENOSPC; |
| |
| spin_lock(&delayed_rsv->lock); |
| if (percpu_counter_compare(&space_info->total_bytes_pinned, |
| bytes - delayed_rsv->size) >= 0) { |
| spin_unlock(&delayed_rsv->lock); |
| return -ENOSPC; |
| } |
| spin_unlock(&delayed_rsv->lock); |
| |
| commit: |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) |
| return -ENOSPC; |
| |
| return btrfs_commit_transaction(trans, root); |
| } |
| |
| enum flush_state { |
| FLUSH_DELAYED_ITEMS_NR = 1, |
| FLUSH_DELAYED_ITEMS = 2, |
| FLUSH_DELALLOC = 3, |
| FLUSH_DELALLOC_WAIT = 4, |
| ALLOC_CHUNK = 5, |
| COMMIT_TRANS = 6, |
| }; |
| |
| static int flush_space(struct btrfs_root *root, |
| struct btrfs_space_info *space_info, u64 num_bytes, |
| u64 orig_bytes, int state) |
| { |
| struct btrfs_trans_handle *trans; |
| int nr; |
| int ret = 0; |
| |
| switch (state) { |
| case FLUSH_DELAYED_ITEMS_NR: |
| case FLUSH_DELAYED_ITEMS: |
| if (state == FLUSH_DELAYED_ITEMS_NR) |
| nr = calc_reclaim_items_nr(root, num_bytes) * 2; |
| else |
| nr = -1; |
| |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| break; |
| } |
| ret = btrfs_run_delayed_items_nr(trans, root, nr); |
| btrfs_end_transaction(trans, root); |
| break; |
| case FLUSH_DELALLOC: |
| case FLUSH_DELALLOC_WAIT: |
| shrink_delalloc(root, num_bytes * 2, orig_bytes, |
| state == FLUSH_DELALLOC_WAIT); |
| break; |
| case ALLOC_CHUNK: |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| break; |
| } |
| ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| btrfs_get_alloc_profile(root, 0), |
| CHUNK_ALLOC_NO_FORCE); |
| btrfs_end_transaction(trans, root); |
| if (ret == -ENOSPC) |
| ret = 0; |
| break; |
| case COMMIT_TRANS: |
| ret = may_commit_transaction(root, space_info, orig_bytes, 0); |
| break; |
| default: |
| ret = -ENOSPC; |
| break; |
| } |
| |
| return ret; |
| } |
| |
| static inline u64 |
| btrfs_calc_reclaim_metadata_size(struct btrfs_root *root, |
| struct btrfs_space_info *space_info) |
| { |
| u64 used; |
| u64 expected; |
| u64 to_reclaim; |
| |
| to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024, |
| 16 * 1024 * 1024); |
| spin_lock(&space_info->lock); |
| if (can_overcommit(root, space_info, to_reclaim, |
| BTRFS_RESERVE_FLUSH_ALL)) { |
| to_reclaim = 0; |
| goto out; |
| } |
| |
| used = space_info->bytes_used + space_info->bytes_reserved + |
| space_info->bytes_pinned + space_info->bytes_readonly + |
| space_info->bytes_may_use; |
| if (can_overcommit(root, space_info, 1024 * 1024, |
| BTRFS_RESERVE_FLUSH_ALL)) |
| expected = div_factor_fine(space_info->total_bytes, 95); |
| else |
| expected = div_factor_fine(space_info->total_bytes, 90); |
| |
| if (used > expected) |
| to_reclaim = used - expected; |
| else |
| to_reclaim = 0; |
| to_reclaim = min(to_reclaim, space_info->bytes_may_use + |
| space_info->bytes_reserved); |
| out: |
| spin_unlock(&space_info->lock); |
| |
| return to_reclaim; |
| } |
| |
| static inline int need_do_async_reclaim(struct btrfs_space_info *space_info, |
| struct btrfs_fs_info *fs_info, u64 used) |
| { |
| u64 thresh = div_factor_fine(space_info->total_bytes, 98); |
| |
| /* If we're just plain full then async reclaim just slows us down. */ |
| if (space_info->bytes_used >= thresh) |
| return 0; |
| |
| return (used >= thresh && !btrfs_fs_closing(fs_info) && |
| !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); |
| } |
| |
| static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info, |
| struct btrfs_fs_info *fs_info, |
| int flush_state) |
| { |
| u64 used; |
| |
| spin_lock(&space_info->lock); |
| /* |
| * We run out of space and have not got any free space via flush_space, |
| * so don't bother doing async reclaim. |
| */ |
| if (flush_state > COMMIT_TRANS && space_info->full) { |
| spin_unlock(&space_info->lock); |
| return 0; |
| } |
| |
| used = space_info->bytes_used + space_info->bytes_reserved + |
| space_info->bytes_pinned + space_info->bytes_readonly + |
| space_info->bytes_may_use; |
| if (need_do_async_reclaim(space_info, fs_info, used)) { |
| spin_unlock(&space_info->lock); |
| return 1; |
| } |
| spin_unlock(&space_info->lock); |
| |
| return 0; |
| } |
| |
| static void btrfs_async_reclaim_metadata_space(struct work_struct *work) |
| { |
| struct btrfs_fs_info *fs_info; |
| struct btrfs_space_info *space_info; |
| u64 to_reclaim; |
| int flush_state; |
| |
| fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); |
| space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); |
| |
| to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root, |
| space_info); |
| if (!to_reclaim) |
| return; |
| |
| flush_state = FLUSH_DELAYED_ITEMS_NR; |
| do { |
| flush_space(fs_info->fs_root, space_info, to_reclaim, |
| to_reclaim, flush_state); |
| flush_state++; |
| if (!btrfs_need_do_async_reclaim(space_info, fs_info, |
| flush_state)) |
| return; |
| } while (flush_state < COMMIT_TRANS); |
| } |
| |
| void btrfs_init_async_reclaim_work(struct work_struct *work) |
| { |
| INIT_WORK(work, btrfs_async_reclaim_metadata_space); |
| } |
| |
| /** |
| * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space |
| * @root - the root we're allocating for |
| * @block_rsv - the block_rsv we're allocating for |
| * @orig_bytes - the number of bytes we want |
| * @flush - whether or not we can flush to make our reservation |
| * |
| * This will reserve orgi_bytes number of bytes from the space info associated |
| * with the block_rsv. If there is not enough space it will make an attempt to |
| * flush out space to make room. It will do this by flushing delalloc if |
| * possible or committing the transaction. If flush is 0 then no attempts to |
| * regain reservations will be made and this will fail if there is not enough |
| * space already. |
| */ |
| static int reserve_metadata_bytes(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, |
| u64 orig_bytes, |
| enum btrfs_reserve_flush_enum flush) |
| { |
| struct btrfs_space_info *space_info = block_rsv->space_info; |
| u64 used; |
| u64 num_bytes = orig_bytes; |
| int flush_state = FLUSH_DELAYED_ITEMS_NR; |
| int ret = 0; |
| bool flushing = false; |
| |
| again: |
| ret = 0; |
| spin_lock(&space_info->lock); |
| /* |
| * We only want to wait if somebody other than us is flushing and we |
| * are actually allowed to flush all things. |
| */ |
| while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing && |
| space_info->flush) { |
| spin_unlock(&space_info->lock); |
| /* |
| * If we have a trans handle we can't wait because the flusher |
| * may have to commit the transaction, which would mean we would |
| * deadlock since we are waiting for the flusher to finish, but |
| * hold the current transaction open. |
| */ |
| if (current->journal_info) |
| return -EAGAIN; |
| ret = wait_event_killable(space_info->wait, !space_info->flush); |
| /* Must have been killed, return */ |
| if (ret) |
| return -EINTR; |
| |
| spin_lock(&space_info->lock); |
| } |
| |
| ret = -ENOSPC; |
| used = space_info->bytes_used + space_info->bytes_reserved + |
| space_info->bytes_pinned + space_info->bytes_readonly + |
| space_info->bytes_may_use; |
| |
| /* |
| * The idea here is that we've not already over-reserved the block group |
| * then we can go ahead and save our reservation first and then start |
| * flushing if we need to. Otherwise if we've already overcommitted |
| * lets start flushing stuff first and then come back and try to make |
| * our reservation. |
| */ |
| if (used <= space_info->total_bytes) { |
| if (used + orig_bytes <= space_info->total_bytes) { |
| space_info->bytes_may_use += orig_bytes; |
| trace_btrfs_space_reservation(root->fs_info, |
| "space_info", space_info->flags, orig_bytes, 1); |
| ret = 0; |
| } else { |
| /* |
| * Ok set num_bytes to orig_bytes since we aren't |
| * overocmmitted, this way we only try and reclaim what |
| * we need. |
| */ |
| num_bytes = orig_bytes; |
| } |
| } else { |
| /* |
| * Ok we're over committed, set num_bytes to the overcommitted |
| * amount plus the amount of bytes that we need for this |
| * reservation. |
| */ |
| num_bytes = used - space_info->total_bytes + |
| (orig_bytes * 2); |
| } |
| |
| if (ret && can_overcommit(root, space_info, orig_bytes, flush)) { |
| space_info->bytes_may_use += orig_bytes; |
| trace_btrfs_space_reservation(root->fs_info, "space_info", |
| space_info->flags, orig_bytes, |
| 1); |
| ret = 0; |
| } |
| |
| /* |
| * Couldn't make our reservation, save our place so while we're trying |
| * to reclaim space we can actually use it instead of somebody else |
| * stealing it from us. |
| * |
| * We make the other tasks wait for the flush only when we can flush |
| * all things. |
| */ |
| if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { |
| flushing = true; |
| space_info->flush = 1; |
| } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| used += orig_bytes; |
| /* |
| * We will do the space reservation dance during log replay, |
| * which means we won't have fs_info->fs_root set, so don't do |
| * the async reclaim as we will panic. |
| */ |
| if (!root->fs_info->log_root_recovering && |
| need_do_async_reclaim(space_info, root->fs_info, used) && |
| !work_busy(&root->fs_info->async_reclaim_work)) |
| queue_work(system_unbound_wq, |
| &root->fs_info->async_reclaim_work); |
| } |
| spin_unlock(&space_info->lock); |
| |
| if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) |
| goto out; |
| |
| ret = flush_space(root, space_info, num_bytes, orig_bytes, |
| flush_state); |
| flush_state++; |
| |
| /* |
| * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock |
| * would happen. So skip delalloc flush. |
| */ |
| if (flush == BTRFS_RESERVE_FLUSH_LIMIT && |
| (flush_state == FLUSH_DELALLOC || |
| flush_state == FLUSH_DELALLOC_WAIT)) |
| flush_state = ALLOC_CHUNK; |
| |
| if (!ret) |
| goto again; |
| else if (flush == BTRFS_RESERVE_FLUSH_LIMIT && |
| flush_state < COMMIT_TRANS) |
| goto again; |
| else if (flush == BTRFS_RESERVE_FLUSH_ALL && |
| flush_state <= COMMIT_TRANS) |
| goto again; |
| |
| out: |
| if (ret == -ENOSPC && |
| unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) { |
| struct btrfs_block_rsv *global_rsv = |
| &root->fs_info->global_block_rsv; |
| |
| if (block_rsv != global_rsv && |
| !block_rsv_use_bytes(global_rsv, orig_bytes)) |
| ret = 0; |
| } |
| if (ret == -ENOSPC) |
| trace_btrfs_space_reservation(root->fs_info, |
| "space_info:enospc", |
| space_info->flags, orig_bytes, 1); |
| if (flushing) { |
| spin_lock(&space_info->lock); |
| space_info->flush = 0; |
| wake_up_all(&space_info->wait); |
| spin_unlock(&space_info->lock); |
| } |
| return ret; |
| } |
| |
| static struct btrfs_block_rsv *get_block_rsv( |
| const struct btrfs_trans_handle *trans, |
| const struct btrfs_root *root) |
| { |
| struct btrfs_block_rsv *block_rsv = NULL; |
| |
| if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) |
| block_rsv = trans->block_rsv; |
| |
| if (root == root->fs_info->csum_root && trans->adding_csums) |
| block_rsv = trans->block_rsv; |
| |
| if (root == root->fs_info->uuid_root) |
| block_rsv = trans->block_rsv; |
| |
| if (!block_rsv) |
| block_rsv = root->block_rsv; |
| |
| if (!block_rsv) |
| block_rsv = &root->fs_info->empty_block_rsv; |
| |
| return block_rsv; |
| } |
| |
| static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, |
| u64 num_bytes) |
| { |
| int ret = -ENOSPC; |
| spin_lock(&block_rsv->lock); |
| if (block_rsv->reserved >= num_bytes) { |
| block_rsv->reserved -= num_bytes; |
| if (block_rsv->reserved < block_rsv->size) |
| block_rsv->full = 0; |
| ret = 0; |
| } |
| spin_unlock(&block_rsv->lock); |
| return ret; |
| } |
| |
| static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv, |
| u64 num_bytes, int update_size) |
| { |
| spin_lock(&block_rsv->lock); |
| block_rsv->reserved += num_bytes; |
| if (update_size) |
| block_rsv->size += num_bytes; |
| else if (block_rsv->reserved >= block_rsv->size) |
| block_rsv->full = 1; |
| spin_unlock(&block_rsv->lock); |
| } |
| |
| int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info, |
| struct btrfs_block_rsv *dest, u64 num_bytes, |
| int min_factor) |
| { |
| struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; |
| u64 min_bytes; |
| |
| if (global_rsv->space_info != dest->space_info) |
| return -ENOSPC; |
| |
| spin_lock(&global_rsv->lock); |
| min_bytes = div_factor(global_rsv->size, min_factor); |
| if (global_rsv->reserved < min_bytes + num_bytes) { |
| spin_unlock(&global_rsv->lock); |
| return -ENOSPC; |
| } |
| global_rsv->reserved -= num_bytes; |
| if (global_rsv->reserved < global_rsv->size) |
| global_rsv->full = 0; |
| spin_unlock(&global_rsv->lock); |
| |
| block_rsv_add_bytes(dest, num_bytes, 1); |
| return 0; |
| } |
| |
| static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info, |
| struct btrfs_block_rsv *block_rsv, |
| struct btrfs_block_rsv *dest, u64 num_bytes) |
| { |
| struct btrfs_space_info *space_info = block_rsv->space_info; |
| |
| spin_lock(&block_rsv->lock); |
| if (num_bytes == (u64)-1) |
| num_bytes = block_rsv->size; |
| block_rsv->size -= num_bytes; |
| if (block_rsv->reserved >= block_rsv->size) { |
| num_bytes = block_rsv->reserved - block_rsv->size; |
| block_rsv->reserved = block_rsv->size; |
| block_rsv->full = 1; |
| } else { |
| num_bytes = 0; |
| } |
| spin_unlock(&block_rsv->lock); |
| |
| if (num_bytes > 0) { |
| if (dest) { |
| spin_lock(&dest->lock); |
| if (!dest->full) { |
| u64 bytes_to_add; |
| |
| bytes_to_add = dest->size - dest->reserved; |
| bytes_to_add = min(num_bytes, bytes_to_add); |
| dest->reserved += bytes_to_add; |
| if (dest->reserved >= dest->size) |
| dest->full = 1; |
| num_bytes -= bytes_to_add; |
| } |
| spin_unlock(&dest->lock); |
| } |
| if (num_bytes) { |
| spin_lock(&space_info->lock); |
| space_info->bytes_may_use -= num_bytes; |
| trace_btrfs_space_reservation(fs_info, "space_info", |
| space_info->flags, num_bytes, 0); |
| spin_unlock(&space_info->lock); |
| } |
| } |
| } |
| |
| static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src, |
| struct btrfs_block_rsv *dst, u64 num_bytes) |
| { |
| int ret; |
| |
| ret = block_rsv_use_bytes(src, num_bytes); |
| if (ret) |
| return ret; |
| |
| block_rsv_add_bytes(dst, num_bytes, 1); |
| return 0; |
| } |
| |
| void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type) |
| { |
| memset(rsv, 0, sizeof(*rsv)); |
| spin_lock_init(&rsv->lock); |
| rsv->type = type; |
| } |
| |
| struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root, |
| unsigned short type) |
| { |
| struct btrfs_block_rsv *block_rsv; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS); |
| if (!block_rsv) |
| return NULL; |
| |
| btrfs_init_block_rsv(block_rsv, type); |
| block_rsv->space_info = __find_space_info(fs_info, |
| BTRFS_BLOCK_GROUP_METADATA); |
| return block_rsv; |
| } |
| |
| void btrfs_free_block_rsv(struct btrfs_root *root, |
| struct btrfs_block_rsv *rsv) |
| { |
| if (!rsv) |
| return; |
| btrfs_block_rsv_release(root, rsv, (u64)-1); |
| kfree(rsv); |
| } |
| |
| void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv) |
| { |
| kfree(rsv); |
| } |
| |
| int btrfs_block_rsv_add(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, u64 num_bytes, |
| enum btrfs_reserve_flush_enum flush) |
| { |
| int ret; |
| |
| if (num_bytes == 0) |
| return 0; |
| |
| ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); |
| if (!ret) { |
| block_rsv_add_bytes(block_rsv, num_bytes, 1); |
| return 0; |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_block_rsv_check(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, int min_factor) |
| { |
| u64 num_bytes = 0; |
| int ret = -ENOSPC; |
| |
| if (!block_rsv) |
| return 0; |
| |
| spin_lock(&block_rsv->lock); |
| num_bytes = div_factor(block_rsv->size, min_factor); |
| if (block_rsv->reserved >= num_bytes) |
| ret = 0; |
| spin_unlock(&block_rsv->lock); |
| |
| return ret; |
| } |
| |
| int btrfs_block_rsv_refill(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, u64 min_reserved, |
| enum btrfs_reserve_flush_enum flush) |
| { |
| u64 num_bytes = 0; |
| int ret = -ENOSPC; |
| |
| if (!block_rsv) |
| return 0; |
| |
| spin_lock(&block_rsv->lock); |
| num_bytes = min_reserved; |
| if (block_rsv->reserved >= num_bytes) |
| ret = 0; |
| else |
| num_bytes -= block_rsv->reserved; |
| spin_unlock(&block_rsv->lock); |
| |
| if (!ret) |
| return 0; |
| |
| ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); |
| if (!ret) { |
| block_rsv_add_bytes(block_rsv, num_bytes, 0); |
| return 0; |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv, |
| struct btrfs_block_rsv *dst_rsv, |
| u64 num_bytes) |
| { |
| return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes); |
| } |
| |
| void btrfs_block_rsv_release(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, |
| u64 num_bytes) |
| { |
| struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; |
| if (global_rsv == block_rsv || |
| block_rsv->space_info != global_rsv->space_info) |
| global_rsv = NULL; |
| block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv, |
| num_bytes); |
| } |
| |
| /* |
| * helper to calculate size of global block reservation. |
| * the desired value is sum of space used by extent tree, |
| * checksum tree and root tree |
| */ |
| static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_space_info *sinfo; |
| u64 num_bytes; |
| u64 meta_used; |
| u64 data_used; |
| int csum_size = btrfs_super_csum_size(fs_info->super_copy); |
| |
| sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA); |
| spin_lock(&sinfo->lock); |
| data_used = sinfo->bytes_used; |
| spin_unlock(&sinfo->lock); |
| |
| sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); |
| spin_lock(&sinfo->lock); |
| if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) |
| data_used = 0; |
| meta_used = sinfo->bytes_used; |
| spin_unlock(&sinfo->lock); |
| |
| num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) * |
| csum_size * 2; |
| num_bytes += div_u64(data_used + meta_used, 50); |
| |
| if (num_bytes * 3 > meta_used) |
| num_bytes = div_u64(meta_used, 3); |
| |
| return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10); |
| } |
| |
| static void update_global_block_rsv(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; |
| struct btrfs_space_info *sinfo = block_rsv->space_info; |
| u64 num_bytes; |
| |
| num_bytes = calc_global_metadata_size(fs_info); |
| |
| spin_lock(&sinfo->lock); |
| spin_lock(&block_rsv->lock); |
| |
| block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024); |
| |
| num_bytes = sinfo->bytes_used + sinfo->bytes_pinned + |
| sinfo->bytes_reserved + sinfo->bytes_readonly + |
| sinfo->bytes_may_use; |
| |
| if (sinfo->total_bytes > num_bytes) { |
| num_bytes = sinfo->total_bytes - num_bytes; |
| block_rsv->reserved += num_bytes; |
| sinfo->bytes_may_use += num_bytes; |
| trace_btrfs_space_reservation(fs_info, "space_info", |
| sinfo->flags, num_bytes, 1); |
| } |
| |
| if (block_rsv->reserved >= block_rsv->size) { |
| num_bytes = block_rsv->reserved - block_rsv->size; |
| sinfo->bytes_may_use -= num_bytes; |
| trace_btrfs_space_reservation(fs_info, "space_info", |
| sinfo->flags, num_bytes, 0); |
| block_rsv->reserved = block_rsv->size; |
| block_rsv->full = 1; |
| } |
| |
| spin_unlock(&block_rsv->lock); |
| spin_unlock(&sinfo->lock); |
| } |
| |
| static void init_global_block_rsv(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_space_info *space_info; |
| |
| space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); |
| fs_info->chunk_block_rsv.space_info = space_info; |
| |
| space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); |
| fs_info->global_block_rsv.space_info = space_info; |
| fs_info->delalloc_block_rsv.space_info = space_info; |
| fs_info->trans_block_rsv.space_info = space_info; |
| fs_info->empty_block_rsv.space_info = space_info; |
| fs_info->delayed_block_rsv.space_info = space_info; |
| |
| fs_info->extent_root->block_rsv = &fs_info->global_block_rsv; |
| fs_info->csum_root->block_rsv = &fs_info->global_block_rsv; |
| fs_info->dev_root->block_rsv = &fs_info->global_block_rsv; |
| fs_info->tree_root->block_rsv = &fs_info->global_block_rsv; |
| if (fs_info->quota_root) |
| fs_info->quota_root->block_rsv = &fs_info->global_block_rsv; |
| fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv; |
| |
| update_global_block_rsv(fs_info); |
| } |
| |
| static void release_global_block_rsv(struct btrfs_fs_info *fs_info) |
| { |
| block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL, |
| (u64)-1); |
| WARN_ON(fs_info->delalloc_block_rsv.size > 0); |
| WARN_ON(fs_info->delalloc_block_rsv.reserved > 0); |
| WARN_ON(fs_info->trans_block_rsv.size > 0); |
| WARN_ON(fs_info->trans_block_rsv.reserved > 0); |
| WARN_ON(fs_info->chunk_block_rsv.size > 0); |
| WARN_ON(fs_info->chunk_block_rsv.reserved > 0); |
| WARN_ON(fs_info->delayed_block_rsv.size > 0); |
| WARN_ON(fs_info->delayed_block_rsv.reserved > 0); |
| } |
| |
| void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| if (!trans->block_rsv) |
| return; |
| |
| if (!trans->bytes_reserved) |
| return; |
| |
| trace_btrfs_space_reservation(root->fs_info, "transaction", |
| trans->transid, trans->bytes_reserved, 0); |
| btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved); |
| trans->bytes_reserved = 0; |
| } |
| |
| /* |
| * To be called after all the new block groups attached to the transaction |
| * handle have been created (btrfs_create_pending_block_groups()). |
| */ |
| void btrfs_trans_release_chunk_metadata(struct btrfs_trans_handle *trans) |
| { |
| struct btrfs_fs_info *fs_info = trans->root->fs_info; |
| |
| if (!trans->chunk_bytes_reserved) |
| return; |
| |
| WARN_ON_ONCE(!list_empty(&trans->new_bgs)); |
| |
| block_rsv_release_bytes(fs_info, &fs_info->chunk_block_rsv, NULL, |
| trans->chunk_bytes_reserved); |
| trans->chunk_bytes_reserved = 0; |
| } |
| |
| /* Can only return 0 or -ENOSPC */ |
| int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans, |
| struct inode *inode) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root); |
| struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv; |
| |
| /* |
| * We need to hold space in order to delete our orphan item once we've |
| * added it, so this takes the reservation so we can release it later |
| * when we are truly done with the orphan item. |
| */ |
| u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1); |
| trace_btrfs_space_reservation(root->fs_info, "orphan", |
| btrfs_ino(inode), num_bytes, 1); |
| return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes); |
| } |
| |
| void btrfs_orphan_release_metadata(struct inode *inode) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1); |
| trace_btrfs_space_reservation(root->fs_info, "orphan", |
| btrfs_ino(inode), num_bytes, 0); |
| btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes); |
| } |
| |
| /* |
| * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation |
| * root: the root of the parent directory |
| * rsv: block reservation |
| * items: the number of items that we need do reservation |
| * qgroup_reserved: used to return the reserved size in qgroup |
| * |
| * This function is used to reserve the space for snapshot/subvolume |
| * creation and deletion. Those operations are different with the |
| * common file/directory operations, they change two fs/file trees |
| * and root tree, the number of items that the qgroup reserves is |
| * different with the free space reservation. So we can not use |
| * the space reseravtion mechanism in start_transaction(). |
| */ |
| int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, |
| struct btrfs_block_rsv *rsv, |
| int items, |
| u64 *qgroup_reserved, |
| bool use_global_rsv) |
| { |
| u64 num_bytes; |
| int ret; |
| struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; |
| |
| if (root->fs_info->quota_enabled) { |
| /* One for parent inode, two for dir entries */ |
| num_bytes = 3 * root->nodesize; |
| ret = btrfs_qgroup_reserve(root, num_bytes); |
| if (ret) |
| return ret; |
| } else { |
| num_bytes = 0; |
| } |
| |
| *qgroup_reserved = num_bytes; |
| |
| num_bytes = btrfs_calc_trans_metadata_size(root, items); |
| rsv->space_info = __find_space_info(root->fs_info, |
| BTRFS_BLOCK_GROUP_METADATA); |
| ret = btrfs_block_rsv_add(root, rsv, num_bytes, |
| BTRFS_RESERVE_FLUSH_ALL); |
| |
| if (ret == -ENOSPC && use_global_rsv) |
| ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes); |
| |
| if (ret) { |
| if (*qgroup_reserved) |
| btrfs_qgroup_free(root, *qgroup_reserved); |
| } |
| |
| return ret; |
| } |
| |
| void btrfs_subvolume_release_metadata(struct btrfs_root *root, |
| struct btrfs_block_rsv *rsv, |
| u64 qgroup_reserved) |
| { |
| btrfs_block_rsv_release(root, rsv, (u64)-1); |
| } |
| |
| /** |
| * drop_outstanding_extent - drop an outstanding extent |
| * @inode: the inode we're dropping the extent for |
| * @num_bytes: the number of bytes we're relaseing. |
| * |
| * This is called when we are freeing up an outstanding extent, either called |
| * after an error or after an extent is written. This will return the number of |
| * reserved extents that need to be freed. This must be called with |
| * BTRFS_I(inode)->lock held. |
| */ |
| static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes) |
| { |
| unsigned drop_inode_space = 0; |
| unsigned dropped_extents = 0; |
| unsigned num_extents = 0; |
| |
| num_extents = (unsigned)div64_u64(num_bytes + |
| BTRFS_MAX_EXTENT_SIZE - 1, |
| BTRFS_MAX_EXTENT_SIZE); |
| ASSERT(num_extents); |
| ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents); |
| BTRFS_I(inode)->outstanding_extents -= num_extents; |
| |
| if (BTRFS_I(inode)->outstanding_extents == 0 && |
| test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED, |
| &BTRFS_I(inode)->runtime_flags)) |
| drop_inode_space = 1; |
| |
| /* |
| * If we have more or the same amount of outsanding extents than we have |
| * reserved then we need to leave the reserved extents count alone. |
| */ |
| if (BTRFS_I(inode)->outstanding_extents >= |
| BTRFS_I(inode)->reserved_extents) |
| return drop_inode_space; |
| |
| dropped_extents = BTRFS_I(inode)->reserved_extents - |
| BTRFS_I(inode)->outstanding_extents; |
| BTRFS_I(inode)->reserved_extents -= dropped_extents; |
| return dropped_extents + drop_inode_space; |
| } |
| |
| /** |
| * calc_csum_metadata_size - return the amount of metada space that must be |
| * reserved/free'd for the given bytes. |
| * @inode: the inode we're manipulating |
| * @num_bytes: the number of bytes in question |
| * @reserve: 1 if we are reserving space, 0 if we are freeing space |
| * |
| * This adjusts the number of csum_bytes in the inode and then returns the |
| * correct amount of metadata that must either be reserved or freed. We |
| * calculate how many checksums we can fit into one leaf and then divide the |
| * number of bytes that will need to be checksumed by this value to figure out |
| * how many checksums will be required. If we are adding bytes then the number |
| * may go up and we will return the number of additional bytes that must be |
| * reserved. If it is going down we will return the number of bytes that must |
| * be freed. |
| * |
| * This must be called with BTRFS_I(inode)->lock held. |
| */ |
| static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes, |
| int reserve) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| u64 old_csums, num_csums; |
| |
| if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM && |
| BTRFS_I(inode)->csum_bytes == 0) |
| return 0; |
| |
| old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes); |
| if (reserve) |
| BTRFS_I(inode)->csum_bytes += num_bytes; |
| else |
| BTRFS_I(inode)->csum_bytes -= num_bytes; |
| num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes); |
| |
| /* No change, no need to reserve more */ |
| if (old_csums == num_csums) |
| return 0; |
| |
| if (reserve) |
| return btrfs_calc_trans_metadata_size(root, |
| num_csums - old_csums); |
| |
| return btrfs_calc_trans_metadata_size(root, old_csums - num_csums); |
| } |
| |
| int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv; |
| u64 to_reserve = 0; |
| u64 csum_bytes; |
| unsigned nr_extents = 0; |
| int extra_reserve = 0; |
| enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL; |
| int ret = 0; |
| bool delalloc_lock = true; |
| u64 to_free = 0; |
| unsigned dropped; |
| |
| /* If we are a free space inode we need to not flush since we will be in |
| * the middle of a transaction commit. We also don't need the delalloc |
| * mutex since we won't race with anybody. We need this mostly to make |
| * lockdep shut its filthy mouth. |
| */ |
| if (btrfs_is_free_space_inode(inode)) { |
| flush = BTRFS_RESERVE_NO_FLUSH; |
| delalloc_lock = false; |
| } |
| |
| if (flush != BTRFS_RESERVE_NO_FLUSH && |
| btrfs_transaction_in_commit(root->fs_info)) |
| schedule_timeout(1); |
| |
| if (delalloc_lock) |
| mutex_lock(&BTRFS_I(inode)->delalloc_mutex); |
| |
| num_bytes = ALIGN(num_bytes, root->sectorsize); |
| |
| spin_lock(&BTRFS_I(inode)->lock); |
| nr_extents = (unsigned)div64_u64(num_bytes + |
| BTRFS_MAX_EXTENT_SIZE - 1, |
| BTRFS_MAX_EXTENT_SIZE); |
| BTRFS_I(inode)->outstanding_extents += nr_extents; |
| nr_extents = 0; |
| |
| if (BTRFS_I(inode)->outstanding_extents > |
| BTRFS_I(inode)->reserved_extents) |
| nr_extents = BTRFS_I(inode)->outstanding_extents - |
| BTRFS_I(inode)->reserved_extents; |
| |
| /* |
| * Add an item to reserve for updating the inode when we complete the |
| * delalloc io. |
| */ |
| if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED, |
| &BTRFS_I(inode)->runtime_flags)) { |
| nr_extents++; |
| extra_reserve = 1; |
| } |
| |
| to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents); |
| to_reserve += calc_csum_metadata_size(inode, num_bytes, 1); |
| csum_bytes = BTRFS_I(inode)->csum_bytes; |
| spin_unlock(&BTRFS_I(inode)->lock); |
| |
| if (root->fs_info->quota_enabled) { |
| ret = btrfs_qgroup_reserve(root, nr_extents * root->nodesize); |
| if (ret) |
| goto out_fail; |
| } |
| |
| ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush); |
| if (unlikely(ret)) { |
| if (root->fs_info->quota_enabled) |
| btrfs_qgroup_free(root, nr_extents * root->nodesize); |
| goto out_fail; |
| } |
| |
| spin_lock(&BTRFS_I(inode)->lock); |
| if (extra_reserve) { |
| set_bit(BTRFS_INODE_DELALLOC_META_RESERVED, |
| &BTRFS_I(inode)->runtime_flags); |
| nr_extents--; |
| } |
| BTRFS_I(inode)->reserved_extents += nr_extents; |
| spin_unlock(&BTRFS_I(inode)->lock); |
| |
| if (delalloc_lock) |
| mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); |
| |
| if (to_reserve) |
| trace_btrfs_space_reservation(root->fs_info, "delalloc", |
| btrfs_ino(inode), to_reserve, 1); |
| block_rsv_add_bytes(block_rsv, to_reserve, 1); |
| |
| return 0; |
| |
| out_fail: |
| spin_lock(&BTRFS_I(inode)->lock); |
| dropped = drop_outstanding_extent(inode, num_bytes); |
| /* |
| * If the inodes csum_bytes is the same as the original |
| * csum_bytes then we know we haven't raced with any free()ers |
| * so we can just reduce our inodes csum bytes and carry on. |
| */ |
| if (BTRFS_I(inode)->csum_bytes == csum_bytes) { |
| calc_csum_metadata_size(inode, num_bytes, 0); |
| } else { |
| u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes; |
| u64 bytes; |
| |
| /* |
| * This is tricky, but first we need to figure out how much we |
| * free'd from any free-ers that occured during this |
| * reservation, so we reset ->csum_bytes to the csum_bytes |
| * before we dropped our lock, and then call the free for the |
| * number of bytes that were freed while we were trying our |
| * reservation. |
| */ |
| bytes = csum_bytes - BTRFS_I(inode)->csum_bytes; |
| BTRFS_I(inode)->csum_bytes = csum_bytes; |
| to_free = calc_csum_metadata_size(inode, bytes, 0); |
| |
| |
| /* |
| * Now we need to see how much we would have freed had we not |
| * been making this reservation and our ->csum_bytes were not |
| * artificially inflated. |
| */ |
| BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes; |
| bytes = csum_bytes - orig_csum_bytes; |
| bytes = calc_csum_metadata_size(inode, bytes, 0); |
| |
| /* |
| * Now reset ->csum_bytes to what it should be. If bytes is |
| * more than to_free then we would have free'd more space had we |
| * not had an artificially high ->csum_bytes, so we need to free |
| * the remainder. If bytes is the same or less then we don't |
| * need to do anything, the other free-ers did the correct |
| * thing. |
| */ |
| BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes; |
| if (bytes > to_free) |
| to_free = bytes - to_free; |
| else |
| to_free = 0; |
| } |
| spin_unlock(&BTRFS_I(inode)->lock); |
| if (dropped) |
| to_free += btrfs_calc_trans_metadata_size(root, dropped); |
| |
| if (to_free) { |
| btrfs_block_rsv_release(root, block_rsv, to_free); |
| trace_btrfs_space_reservation(root->fs_info, "delalloc", |
| btrfs_ino(inode), to_free, 0); |
| } |
| if (delalloc_lock) |
| mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); |
| return ret; |
| } |
| |
| /** |
| * btrfs_delalloc_release_metadata - release a metadata reservation for an inode |
| * @inode: the inode to release the reservation for |
| * @num_bytes: the number of bytes we're releasing |
| * |
| * This will release the metadata reservation for an inode. This can be called |
| * once we complete IO for a given set of bytes to release their metadata |
| * reservations. |
| */ |
| void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes) |
| { |
| struct btrfs_root *root = BTRFS_I(inode)->root; |
| u64 to_free = 0; |
| unsigned dropped; |
| |
| num_bytes = ALIGN(num_bytes, root->sectorsize); |
| spin_lock(&BTRFS_I(inode)->lock); |
| dropped = drop_outstanding_extent(inode, num_bytes); |
| |
| if (num_bytes) |
| to_free = calc_csum_metadata_size(inode, num_bytes, 0); |
| spin_unlock(&BTRFS_I(inode)->lock); |
| if (dropped > 0) |
| to_free += btrfs_calc_trans_metadata_size(root, dropped); |
| |
| if (btrfs_test_is_dummy_root(root)) |
| return; |
| |
| trace_btrfs_space_reservation(root->fs_info, "delalloc", |
| btrfs_ino(inode), to_free, 0); |
| |
| btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv, |
| to_free); |
| } |
| |
| /** |
| * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc |
| * @inode: inode we're writing to |
| * @num_bytes: the number of bytes we want to allocate |
| * |
| * This will do the following things |
| * |
| * o reserve space in the data space info for num_bytes |
| * o reserve space in the metadata space info based on number of outstanding |
| * extents and how much csums will be needed |
| * o add to the inodes ->delalloc_bytes |
| * o add it to the fs_info's delalloc inodes list. |
| * |
| * This will return 0 for success and -ENOSPC if there is no space left. |
| */ |
| int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes) |
| { |
| int ret; |
| |
| ret = btrfs_check_data_free_space(inode, num_bytes, num_bytes); |
| if (ret) |
| return ret; |
| |
| ret = btrfs_delalloc_reserve_metadata(inode, num_bytes); |
| if (ret) { |
| btrfs_free_reserved_data_space(inode, num_bytes); |
| return ret; |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * btrfs_delalloc_release_space - release data and metadata space for delalloc |
| * @inode: inode we're releasing space for |
| * @num_bytes: the number of bytes we want to free up |
| * |
| * This must be matched with a call to btrfs_delalloc_reserve_space. This is |
| * called in the case that we don't need the metadata AND data reservations |
| * anymore. So if there is an error or we insert an inline extent. |
| * |
| * This function will release the metadata space that was not used and will |
| * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes |
| * list if there are no delalloc bytes left. |
| */ |
| void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes) |
| { |
| btrfs_delalloc_release_metadata(inode, num_bytes); |
| btrfs_free_reserved_data_space(inode, num_bytes); |
| } |
| |
| static int update_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr, |
| u64 num_bytes, int alloc) |
| { |
| struct btrfs_block_group_cache *cache = NULL; |
| struct btrfs_fs_info *info = root->fs_info; |
| u64 total = num_bytes; |
| u64 old_val; |
| u64 byte_in_group; |
| int factor; |
| |
| /* block accounting for super block */ |
| spin_lock(&info->delalloc_root_lock); |
| old_val = btrfs_super_bytes_used(info->super_copy); |
| if (alloc) |
| old_val += num_bytes; |
| else |
| old_val -= num_bytes; |
| btrfs_set_super_bytes_used(info->super_copy, old_val); |
| spin_unlock(&info->delalloc_root_lock); |
| |
| while (total) { |
| cache = btrfs_lookup_block_group(info, bytenr); |
| if (!cache) |
| return -ENOENT; |
| if (cache->flags & (BTRFS_BLOCK_GROUP_DUP | |
| BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| factor = 2; |
| else |
| factor = 1; |
| /* |
| * If this block group has free space cache written out, we |
| * need to make sure to load it if we are removing space. This |
| * is because we need the unpinning stage to actually add the |
| * space back to the block group, otherwise we will leak space. |
| */ |
| if (!alloc && cache->cached == BTRFS_CACHE_NO) |
| cache_block_group(cache, 1); |
| |
| byte_in_group = bytenr - cache->key.objectid; |
| WARN_ON(byte_in_group > cache->key.offset); |
| |
| spin_lock(&cache->space_info->lock); |
| spin_lock(&cache->lock); |
| |
| if (btrfs_test_opt(root, SPACE_CACHE) && |
| cache->disk_cache_state < BTRFS_DC_CLEAR) |
| cache->disk_cache_state = BTRFS_DC_CLEAR; |
| |
| old_val = btrfs_block_group_used(&cache->item); |
| num_bytes = min(total, cache->key.offset - byte_in_group); |
| if (alloc) { |
| old_val += num_bytes; |
| btrfs_set_block_group_used(&cache->item, old_val); |
| cache->reserved -= num_bytes; |
| cache->space_info->bytes_reserved -= num_bytes; |
| cache->space_info->bytes_used += num_bytes; |
| cache->space_info->disk_used += num_bytes * factor; |
| spin_unlock(&cache->lock); |
| spin_unlock(&cache->space_info->lock); |
| } else { |
| old_val -= num_bytes; |
| btrfs_set_block_group_used(&cache->item, old_val); |
| cache->pinned += num_bytes; |
| cache->space_info->bytes_pinned += num_bytes; |
| cache->space_info->bytes_used -= num_bytes; |
| cache->space_info->disk_used -= num_bytes * factor; |
| spin_unlock(&cache->lock); |
| spin_unlock(&cache->space_info->lock); |
| |
| set_extent_dirty(info->pinned_extents, |
| bytenr, bytenr + num_bytes - 1, |
| GFP_NOFS | __GFP_NOFAIL); |
| /* |
| * No longer have used bytes in this block group, queue |
| * it for deletion. |
| */ |
| if (old_val == 0) { |
| spin_lock(&info->unused_bgs_lock); |
| if (list_empty(&cache->bg_list)) { |
| btrfs_get_block_group(cache); |
| list_add_tail(&cache->bg_list, |
| &info->unused_bgs); |
| } |
| spin_unlock(&info->unused_bgs_lock); |
| } |
| } |
| |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| if (list_empty(&cache->dirty_list)) { |
| list_add_tail(&cache->dirty_list, |
| &trans->transaction->dirty_bgs); |
| trans->transaction->num_dirty_bgs++; |
| btrfs_get_block_group(cache); |
| } |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| |
| btrfs_put_block_group(cache); |
| total -= num_bytes; |
| bytenr += num_bytes; |
| } |
| return 0; |
| } |
| |
| static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) |
| { |
| struct btrfs_block_group_cache *cache; |
| u64 bytenr; |
| |
| spin_lock(&root->fs_info->block_group_cache_lock); |
| bytenr = root->fs_info->first_logical_byte; |
| spin_unlock(&root->fs_info->block_group_cache_lock); |
| |
| if (bytenr < (u64)-1) |
| return bytenr; |
| |
| cache = btrfs_lookup_first_block_group(root->fs_info, search_start); |
| if (!cache) |
| return 0; |
| |
| bytenr = cache->key.objectid; |
| btrfs_put_block_group(cache); |
| |
| return bytenr; |
| } |
| |
| static int pin_down_extent(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache, |
| u64 bytenr, u64 num_bytes, int reserved) |
| { |
| spin_lock(&cache->space_info->lock); |
| spin_lock(&cache->lock); |
| cache->pinned += num_bytes; |
| cache->space_info->bytes_pinned += num_bytes; |
| if (reserved) { |
| cache->reserved -= num_bytes; |
| cache->space_info->bytes_reserved -= num_bytes; |
| } |
| spin_unlock(&cache->lock); |
| spin_unlock(&cache->space_info->lock); |
| |
| set_extent_dirty(root->fs_info->pinned_extents, bytenr, |
| bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL); |
| if (reserved) |
| trace_btrfs_reserved_extent_free(root, bytenr, num_bytes); |
| return 0; |
| } |
| |
| /* |
| * this function must be called within transaction |
| */ |
| int btrfs_pin_extent(struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, int reserved) |
| { |
| struct btrfs_block_group_cache *cache; |
| |
| cache = btrfs_lookup_block_group(root->fs_info, bytenr); |
| BUG_ON(!cache); /* Logic error */ |
| |
| pin_down_extent(root, cache, bytenr, num_bytes, reserved); |
| |
| btrfs_put_block_group(cache); |
| return 0; |
| } |
| |
| /* |
| * this function must be called within transaction |
| */ |
| int btrfs_pin_extent_for_log_replay(struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes) |
| { |
| struct btrfs_block_group_cache *cache; |
| int ret; |
| |
| cache = btrfs_lookup_block_group(root->fs_info, bytenr); |
| if (!cache) |
| return -EINVAL; |
| |
| /* |
| * pull in the free space cache (if any) so that our pin |
| * removes the free space from the cache. We have load_only set |
| * to one because the slow code to read in the free extents does check |
| * the pinned extents. |
| */ |
| cache_block_group(cache, 1); |
| |
| pin_down_extent(root, cache, bytenr, num_bytes, 0); |
| |
| /* remove us from the free space cache (if we're there at all) */ |
| ret = btrfs_remove_free_space(cache, bytenr, num_bytes); |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| |
| static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes) |
| { |
| int ret; |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_caching_control *caching_ctl; |
| |
| block_group = btrfs_lookup_block_group(root->fs_info, start); |
| if (!block_group) |
| return -EINVAL; |
| |
| cache_block_group(block_group, 0); |
| caching_ctl = get_caching_control(block_group); |
| |
| if (!caching_ctl) { |
| /* Logic error */ |
| BUG_ON(!block_group_cache_done(block_group)); |
| ret = btrfs_remove_free_space(block_group, start, num_bytes); |
| } else { |
| mutex_lock(&caching_ctl->mutex); |
| |
| if (start >= caching_ctl->progress) { |
| ret = add_excluded_extent(root, start, num_bytes); |
| } else if (start + num_bytes <= caching_ctl->progress) { |
| ret = btrfs_remove_free_space(block_group, |
| start, num_bytes); |
| } else { |
| num_bytes = caching_ctl->progress - start; |
| ret = btrfs_remove_free_space(block_group, |
| start, num_bytes); |
| if (ret) |
| goto out_lock; |
| |
| num_bytes = (start + num_bytes) - |
| caching_ctl->progress; |
| start = caching_ctl->progress; |
| ret = add_excluded_extent(root, start, num_bytes); |
| } |
| out_lock: |
| mutex_unlock(&caching_ctl->mutex); |
| put_caching_control(caching_ctl); |
| } |
| btrfs_put_block_group(block_group); |
| return ret; |
| } |
| |
| int btrfs_exclude_logged_extents(struct btrfs_root *log, |
| struct extent_buffer *eb) |
| { |
| struct btrfs_file_extent_item *item; |
| struct btrfs_key key; |
| int found_type; |
| int i; |
| |
| if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS)) |
| return 0; |
| |
| for (i = 0; i < btrfs_header_nritems(eb); i++) { |
| btrfs_item_key_to_cpu(eb, &key, i); |
| if (key.type != BTRFS_EXTENT_DATA_KEY) |
| continue; |
| item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); |
| found_type = btrfs_file_extent_type(eb, item); |
| if (found_type == BTRFS_FILE_EXTENT_INLINE) |
| continue; |
| if (btrfs_file_extent_disk_bytenr(eb, item) == 0) |
| continue; |
| key.objectid = btrfs_file_extent_disk_bytenr(eb, item); |
| key.offset = btrfs_file_extent_disk_num_bytes(eb, item); |
| __exclude_logged_extent(log, key.objectid, key.offset); |
| } |
| |
| return 0; |
| } |
| |
| /** |
| * btrfs_update_reserved_bytes - update the block_group and space info counters |
| * @cache: The cache we are manipulating |
| * @num_bytes: The number of bytes in question |
| * @reserve: One of the reservation enums |
| * @delalloc: The blocks are allocated for the delalloc write |
| * |
| * This is called by the allocator when it reserves space, or by somebody who is |
| * freeing space that was never actually used on disk. For example if you |
| * reserve some space for a new leaf in transaction A and before transaction A |
| * commits you free that leaf, you call this with reserve set to 0 in order to |
| * clear the reservation. |
| * |
| * Metadata reservations should be called with RESERVE_ALLOC so we do the proper |
| * ENOSPC accounting. For data we handle the reservation through clearing the |
| * delalloc bits in the io_tree. We have to do this since we could end up |
| * allocating less disk space for the amount of data we have reserved in the |
| * case of compression. |
| * |
| * If this is a reservation and the block group has become read only we cannot |
| * make the reservation and return -EAGAIN, otherwise this function always |
| * succeeds. |
| */ |
| static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache, |
| u64 num_bytes, int reserve, int delalloc) |
| { |
| struct btrfs_space_info *space_info = cache->space_info; |
| int ret = 0; |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&cache->lock); |
| if (reserve != RESERVE_FREE) { |
| if (cache->ro) { |
| ret = -EAGAIN; |
| } else { |
| cache->reserved += num_bytes; |
| space_info->bytes_reserved += num_bytes; |
| if (reserve == RESERVE_ALLOC) { |
| trace_btrfs_space_reservation(cache->fs_info, |
| "space_info", space_info->flags, |
| num_bytes, 0); |
| space_info->bytes_may_use -= num_bytes; |
| } |
| |
| if (delalloc) |
| cache->delalloc_bytes += num_bytes; |
| } |
| } else { |
| if (cache->ro) |
| space_info->bytes_readonly += num_bytes; |
| cache->reserved -= num_bytes; |
| space_info->bytes_reserved -= num_bytes; |
| |
| if (delalloc) |
| cache->delalloc_bytes -= num_bytes; |
| } |
| spin_unlock(&cache->lock); |
| spin_unlock(&space_info->lock); |
| return ret; |
| } |
| |
| void btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_caching_control *next; |
| struct btrfs_caching_control *caching_ctl; |
| struct btrfs_block_group_cache *cache; |
| |
| down_write(&fs_info->commit_root_sem); |
| |
| list_for_each_entry_safe(caching_ctl, next, |
| &fs_info->caching_block_groups, list) { |
| cache = caching_ctl->block_group; |
| if (block_group_cache_done(cache)) { |
| cache->last_byte_to_unpin = (u64)-1; |
| list_del_init(&caching_ctl->list); |
| put_caching_control(caching_ctl); |
| } else { |
| cache->last_byte_to_unpin = caching_ctl->progress; |
| } |
| } |
| |
| if (fs_info->pinned_extents == &fs_info->freed_extents[0]) |
| fs_info->pinned_extents = &fs_info->freed_extents[1]; |
| else |
| fs_info->pinned_extents = &fs_info->freed_extents[0]; |
| |
| up_write(&fs_info->commit_root_sem); |
| |
| update_global_block_rsv(fs_info); |
| } |
| |
| static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end, |
| const bool return_free_space) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_block_group_cache *cache = NULL; |
| struct btrfs_space_info *space_info; |
| struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; |
| u64 len; |
| bool readonly; |
| |
| while (start <= end) { |
| readonly = false; |
| if (!cache || |
| start >= cache->key.objectid + cache->key.offset) { |
| if (cache) |
| btrfs_put_block_group(cache); |
| cache = btrfs_lookup_block_group(fs_info, start); |
| BUG_ON(!cache); /* Logic error */ |
| } |
| |
| len = cache->key.objectid + cache->key.offset - start; |
| len = min(len, end + 1 - start); |
| |
| if (start < cache->last_byte_to_unpin) { |
| len = min(len, cache->last_byte_to_unpin - start); |
| if (return_free_space) |
| btrfs_add_free_space(cache, start, len); |
| } |
| |
| start += len; |
| space_info = cache->space_info; |
| |
| spin_lock(&space_info->lock); |
| spin_lock(&cache->lock); |
| cache->pinned -= len; |
| space_info->bytes_pinned -= len; |
| percpu_counter_add(&space_info->total_bytes_pinned, -len); |
| if (cache->ro) { |
| space_info->bytes_readonly += len; |
| readonly = true; |
| } |
| spin_unlock(&cache->lock); |
| if (!readonly && global_rsv->space_info == space_info) { |
| spin_lock(&global_rsv->lock); |
| if (!global_rsv->full) { |
| len = min(len, global_rsv->size - |
| global_rsv->reserved); |
| global_rsv->reserved += len; |
| space_info->bytes_may_use += len; |
| if (global_rsv->reserved >= global_rsv->size) |
| global_rsv->full = 1; |
| } |
| spin_unlock(&global_rsv->lock); |
| } |
| spin_unlock(&space_info->lock); |
| } |
| |
| if (cache) |
| btrfs_put_block_group(cache); |
| return 0; |
| } |
| |
| int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_block_group_cache *block_group, *tmp; |
| struct list_head *deleted_bgs; |
| struct extent_io_tree *unpin; |
| u64 start; |
| u64 end; |
| int ret; |
| |
| if (fs_info->pinned_extents == &fs_info->freed_extents[0]) |
| unpin = &fs_info->freed_extents[1]; |
| else |
| unpin = &fs_info->freed_extents[0]; |
| |
| while (!trans->aborted) { |
| mutex_lock(&fs_info->unused_bg_unpin_mutex); |
| ret = find_first_extent_bit(unpin, 0, &start, &end, |
| EXTENT_DIRTY, NULL); |
| if (ret) { |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| break; |
| } |
| |
| if (btrfs_test_opt(root, DISCARD)) |
| ret = btrfs_discard_extent(root, start, |
| end + 1 - start, NULL); |
| |
| clear_extent_dirty(unpin, start, end, GFP_NOFS); |
| unpin_extent_range(root, start, end, true); |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| cond_resched(); |
| } |
| |
| /* |
| * Transaction is finished. We don't need the lock anymore. We |
| * do need to clean up the block groups in case of a transaction |
| * abort. |
| */ |
| deleted_bgs = &trans->transaction->deleted_bgs; |
| list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) { |
| u64 trimmed = 0; |
| |
| ret = -EROFS; |
| if (!trans->aborted) |
| ret = btrfs_discard_extent(root, |
| block_group->key.objectid, |
| block_group->key.offset, |
| &trimmed); |
| |
| list_del_init(&block_group->bg_list); |
| btrfs_put_block_group_trimming(block_group); |
| btrfs_put_block_group(block_group); |
| |
| if (ret) { |
| const char *errstr = btrfs_decode_error(ret); |
| btrfs_warn(fs_info, |
| "Discard failed while removing blockgroup: errno=%d %s\n", |
| ret, errstr); |
| } |
| } |
| |
| return 0; |
| } |
| |
| static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes, |
| u64 owner, u64 root_objectid) |
| { |
| struct btrfs_space_info *space_info; |
| u64 flags; |
| |
| if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID) |
| flags = BTRFS_BLOCK_GROUP_SYSTEM; |
| else |
| flags = BTRFS_BLOCK_GROUP_METADATA; |
| } else { |
| flags = BTRFS_BLOCK_GROUP_DATA; |
| } |
| |
| space_info = __find_space_info(fs_info, flags); |
| BUG_ON(!space_info); /* Logic bug */ |
| percpu_counter_add(&space_info->total_bytes_pinned, num_bytes); |
| } |
| |
| |
| static int __btrfs_free_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_delayed_ref_node *node, u64 parent, |
| u64 root_objectid, u64 owner_objectid, |
| u64 owner_offset, int refs_to_drop, |
| struct btrfs_delayed_extent_op *extent_op) |
| { |
| struct btrfs_key key; |
| struct btrfs_path *path; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_root *extent_root = info->extent_root; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_item *ei; |
| struct btrfs_extent_inline_ref *iref; |
| int ret; |
| int is_data; |
| int extent_slot = 0; |
| int found_extent = 0; |
| int num_to_del = 1; |
| int no_quota = node->no_quota; |
| u32 item_size; |
| u64 refs; |
| u64 bytenr = node->bytenr; |
| u64 num_bytes = node->num_bytes; |
| int last_ref = 0; |
| bool skinny_metadata = btrfs_fs_incompat(root->fs_info, |
| SKINNY_METADATA); |
| |
| if (!info->quota_enabled || !is_fstree(root_objectid)) |
| no_quota = 1; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->reada = 1; |
| path->leave_spinning = 1; |
| |
| is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID; |
| BUG_ON(!is_data && refs_to_drop != 1); |
| |
| if (is_data) |
| skinny_metadata = 0; |
| |
| ret = lookup_extent_backref(trans, extent_root, path, &iref, |
| bytenr, num_bytes, parent, |
| root_objectid, owner_objectid, |
| owner_offset); |
| if (ret == 0) { |
| extent_slot = path->slots[0]; |
| while (extent_slot >= 0) { |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| extent_slot); |
| if (key.objectid != bytenr) |
| break; |
| if (key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == num_bytes) { |
| found_extent = 1; |
| break; |
| } |
| if (key.type == BTRFS_METADATA_ITEM_KEY && |
| key.offset == owner_objectid) { |
| found_extent = 1; |
| break; |
| } |
| if (path->slots[0] - extent_slot > 5) |
| break; |
| extent_slot--; |
| } |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| item_size = btrfs_item_size_nr(path->nodes[0], extent_slot); |
| if (found_extent && item_size < sizeof(*ei)) |
| found_extent = 0; |
| #endif |
| if (!found_extent) { |
| BUG_ON(iref); |
| ret = remove_extent_backref(trans, extent_root, path, |
| NULL, refs_to_drop, |
| is_data, &last_ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| btrfs_release_path(path); |
| path->leave_spinning = 1; |
| |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = num_bytes; |
| |
| if (!is_data && skinny_metadata) { |
| key.type = BTRFS_METADATA_ITEM_KEY; |
| key.offset = owner_objectid; |
| } |
| |
| ret = btrfs_search_slot(trans, extent_root, |
| &key, path, -1, 1); |
| if (ret > 0 && skinny_metadata && path->slots[0]) { |
| /* |
| * Couldn't find our skinny metadata item, |
| * see if we have ye olde extent item. |
| */ |
| path->slots[0]--; |
| btrfs_item_key_to_cpu(path->nodes[0], &key, |
| path->slots[0]); |
| if (key.objectid == bytenr && |
| key.type == BTRFS_EXTENT_ITEM_KEY && |
| key.offset == num_bytes) |
| ret = 0; |
| } |
| |
| if (ret > 0 && skinny_metadata) { |
| skinny_metadata = false; |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = num_bytes; |
| btrfs_release_path(path); |
| ret = btrfs_search_slot(trans, extent_root, |
| &key, path, -1, 1); |
| } |
| |
| if (ret) { |
| btrfs_err(info, "umm, got %d back from search, was looking for %llu", |
| ret, bytenr); |
| if (ret > 0) |
| btrfs_print_leaf(extent_root, |
| path->nodes[0]); |
| } |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| extent_slot = path->slots[0]; |
| } |
| } else if (WARN_ON(ret == -ENOENT)) { |
| btrfs_print_leaf(extent_root, path->nodes[0]); |
| btrfs_err(info, |
| "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu", |
| bytenr, parent, root_objectid, owner_objectid, |
| owner_offset); |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } else { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, extent_slot); |
| #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 |
| if (item_size < sizeof(*ei)) { |
| BUG_ON(found_extent || extent_slot != path->slots[0]); |
| ret = convert_extent_item_v0(trans, extent_root, path, |
| owner_objectid, 0); |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| |
| btrfs_release_path(path); |
| path->leave_spinning = 1; |
| |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_ITEM_KEY; |
| key.offset = num_bytes; |
| |
| ret = btrfs_search_slot(trans, extent_root, &key, path, |
| -1, 1); |
| if (ret) { |
| btrfs_err(info, "umm, got %d back from search, was looking for %llu", |
| ret, bytenr); |
| btrfs_print_leaf(extent_root, path->nodes[0]); |
| } |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| |
| extent_slot = path->slots[0]; |
| leaf = path->nodes[0]; |
| item_size = btrfs_item_size_nr(leaf, extent_slot); |
| } |
| #endif |
| BUG_ON(item_size < sizeof(*ei)); |
| ei = btrfs_item_ptr(leaf, extent_slot, |
| struct btrfs_extent_item); |
| if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID && |
| key.type == BTRFS_EXTENT_ITEM_KEY) { |
| struct btrfs_tree_block_info *bi; |
| BUG_ON(item_size < sizeof(*ei) + sizeof(*bi)); |
| bi = (struct btrfs_tree_block_info *)(ei + 1); |
| WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi)); |
| } |
| |
| refs = btrfs_extent_refs(leaf, ei); |
| if (refs < refs_to_drop) { |
| btrfs_err(info, "trying to drop %d refs but we only have %Lu " |
| "for bytenr %Lu", refs_to_drop, refs, bytenr); |
| ret = -EINVAL; |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| refs -= refs_to_drop; |
| |
| if (refs > 0) { |
| if (extent_op) |
| __run_delayed_extent_op(extent_op, leaf, ei); |
| /* |
| * In the case of inline back ref, reference count will |
| * be updated by remove_extent_backref |
| */ |
| if (iref) { |
| BUG_ON(!found_extent); |
| } else { |
| btrfs_set_extent_refs(leaf, ei, refs); |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| if (found_extent) { |
| ret = remove_extent_backref(trans, extent_root, path, |
| iref, refs_to_drop, |
| is_data, &last_ref); |
| if (ret) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| } |
| add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid, |
| root_objectid); |
| } else { |
| if (found_extent) { |
| BUG_ON(is_data && refs_to_drop != |
| extent_data_ref_count(path, iref)); |
| if (iref) { |
| BUG_ON(path->slots[0] != extent_slot); |
| } else { |
| BUG_ON(path->slots[0] != extent_slot + 1); |
| path->slots[0] = extent_slot; |
| num_to_del = 2; |
| } |
| } |
| |
| last_ref = 1; |
| ret = btrfs_del_items(trans, extent_root, path, path->slots[0], |
| num_to_del); |
| if (ret) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| btrfs_release_path(path); |
| |
| if (is_data) { |
| ret = btrfs_del_csums(trans, root, bytenr, num_bytes); |
| if (ret) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| } |
| |
| ret = update_block_group(trans, root, bytenr, num_bytes, 0); |
| if (ret) { |
| btrfs_abort_transaction(trans, extent_root, ret); |
| goto out; |
| } |
| } |
| btrfs_release_path(path); |
| |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * when we free an block, it is possible (and likely) that we free the last |
| * delayed ref for that extent as well. This searches the delayed ref tree for |
| * a given extent, and if there are no other delayed refs to be processed, it |
| * removes it from the tree. |
| */ |
| static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr) |
| { |
| struct btrfs_delayed_ref_head *head; |
| struct btrfs_delayed_ref_root *delayed_refs; |
| int ret = 0; |
| |
| delayed_refs = &trans->transaction->delayed_refs; |
| spin_lock(&delayed_refs->lock); |
| head = btrfs_find_delayed_ref_head(trans, bytenr); |
| if (!head) |
| goto out_delayed_unlock; |
| |
| spin_lock(&head->lock); |
| if (!list_empty(&head->ref_list)) |
| goto out; |
| |
| if (head->extent_op) { |
| if (!head->must_insert_reserved) |
| goto out; |
| btrfs_free_delayed_extent_op(head->extent_op); |
| head->extent_op = NULL; |
| } |
| |
| /* |
| * waiting for the lock here would deadlock. If someone else has it |
| * locked they are already in the process of dropping it anyway |
| */ |
| if (!mutex_trylock(&head->mutex)) |
| goto out; |
| |
| /* |
| * at this point we have a head with no other entries. Go |
| * ahead and process it. |
| */ |
| head->node.in_tree = 0; |
| rb_erase(&head->href_node, &delayed_refs->href_root); |
| |
| atomic_dec(&delayed_refs->num_entries); |
| |
| /* |
| * we don't take a ref on the node because we're removing it from the |
| * tree, so we just steal the ref the tree was holding. |
| */ |
| delayed_refs->num_heads--; |
| if (head->processing == 0) |
| delayed_refs->num_heads_ready--; |
| head->processing = 0; |
| spin_unlock(&head->lock); |
| spin_unlock(&delayed_refs->lock); |
| |
| BUG_ON(head->extent_op); |
| if (head->must_insert_reserved) |
| ret = 1; |
| |
| mutex_unlock(&head->mutex); |
| btrfs_put_delayed_ref(&head->node); |
| return ret; |
| out: |
| spin_unlock(&head->lock); |
| |
| out_delayed_unlock: |
| spin_unlock(&delayed_refs->lock); |
| return 0; |
| } |
| |
| void btrfs_free_tree_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| u64 parent, int last_ref) |
| { |
| int pin = 1; |
| int ret; |
| |
| if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { |
| ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, |
| buf->start, buf->len, |
| parent, root->root_key.objectid, |
| btrfs_header_level(buf), |
| BTRFS_DROP_DELAYED_REF, NULL, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| |
| if (!last_ref) |
| return; |
| |
| if (btrfs_header_generation(buf) == trans->transid) { |
| struct btrfs_block_group_cache *cache; |
| |
| if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { |
| ret = check_ref_cleanup(trans, root, buf->start); |
| if (!ret) |
| goto out; |
| } |
| |
| cache = btrfs_lookup_block_group(root->fs_info, buf->start); |
| |
| if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { |
| pin_down_extent(root, cache, buf->start, buf->len, 1); |
| btrfs_put_block_group(cache); |
| goto out; |
| } |
| |
| WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)); |
| |
| btrfs_add_free_space(cache, buf->start, buf->len); |
| btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0); |
| btrfs_put_block_group(cache); |
| trace_btrfs_reserved_extent_free(root, buf->start, buf->len); |
| pin = 0; |
| } |
| out: |
| if (pin) |
| add_pinned_bytes(root->fs_info, buf->len, |
| btrfs_header_level(buf), |
| root->root_key.objectid); |
| |
| /* |
| * Deleting the buffer, clear the corrupt flag since it doesn't matter |
| * anymore. |
| */ |
| clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); |
| } |
| |
| /* Can return -ENOMEM */ |
| int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, |
| u64 owner, u64 offset, int no_quota) |
| { |
| int ret; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| if (btrfs_test_is_dummy_root(root)) |
| return 0; |
| |
| add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid); |
| |
| /* |
| * tree log blocks never actually go into the extent allocation |
| * tree, just update pinning info and exit early. |
| */ |
| if (root_objectid == BTRFS_TREE_LOG_OBJECTID) { |
| WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID); |
| /* unlocks the pinned mutex */ |
| btrfs_pin_extent(root, bytenr, num_bytes, 1); |
| ret = 0; |
| } else if (owner < BTRFS_FIRST_FREE_OBJECTID) { |
| ret = btrfs_add_delayed_tree_ref(fs_info, trans, bytenr, |
| num_bytes, |
| parent, root_objectid, (int)owner, |
| BTRFS_DROP_DELAYED_REF, NULL, no_quota); |
| } else { |
| ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, |
| num_bytes, |
| parent, root_objectid, owner, |
| offset, BTRFS_DROP_DELAYED_REF, |
| NULL, no_quota); |
| } |
| return ret; |
| } |
| |
| /* |
| * when we wait for progress in the block group caching, its because |
| * our allocation attempt failed at least once. So, we must sleep |
| * and let some progress happen before we try again. |
| * |
| * This function will sleep at least once waiting for new free space to |
| * show up, and then it will check the block group free space numbers |
| * for our min num_bytes. Another option is to have it go ahead |
| * and look in the rbtree for a free extent of a given size, but this |
| * is a good start. |
| * |
| * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using |
| * any of the information in this block group. |
| */ |
| static noinline void |
| wait_block_group_cache_progress(struct btrfs_block_group_cache *cache, |
| u64 num_bytes) |
| { |
| struct btrfs_caching_control *caching_ctl; |
| |
| caching_ctl = get_caching_control(cache); |
| if (!caching_ctl) |
| return; |
| |
| wait_event(caching_ctl->wait, block_group_cache_done(cache) || |
| (cache->free_space_ctl->free_space >= num_bytes)); |
| |
| put_caching_control(caching_ctl); |
| } |
| |
| static noinline int |
| wait_block_group_cache_done(struct btrfs_block_group_cache *cache) |
| { |
| struct btrfs_caching_control *caching_ctl; |
| int ret = 0; |
| |
| caching_ctl = get_caching_control(cache); |
| if (!caching_ctl) |
| return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0; |
| |
| wait_event(caching_ctl->wait, block_group_cache_done(cache)); |
| if (cache->cached == BTRFS_CACHE_ERROR) |
| ret = -EIO; |
| put_caching_control(caching_ctl); |
| return ret; |
| } |
| |
| int __get_raid_index(u64 flags) |
| { |
| if (flags & BTRFS_BLOCK_GROUP_RAID10) |
| return BTRFS_RAID_RAID10; |
| else if (flags & BTRFS_BLOCK_GROUP_RAID1) |
| return BTRFS_RAID_RAID1; |
| else if (flags & BTRFS_BLOCK_GROUP_DUP) |
| return BTRFS_RAID_DUP; |
| else if (flags & BTRFS_BLOCK_GROUP_RAID0) |
| return BTRFS_RAID_RAID0; |
| else if (flags & BTRFS_BLOCK_GROUP_RAID5) |
| return BTRFS_RAID_RAID5; |
| else if (flags & BTRFS_BLOCK_GROUP_RAID6) |
| return BTRFS_RAID_RAID6; |
| |
| return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */ |
| } |
| |
| int get_block_group_index(struct btrfs_block_group_cache *cache) |
| { |
| return __get_raid_index(cache->flags); |
| } |
| |
| static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = { |
| [BTRFS_RAID_RAID10] = "raid10", |
| [BTRFS_RAID_RAID1] = "raid1", |
| [BTRFS_RAID_DUP] = "dup", |
| [BTRFS_RAID_RAID0] = "raid0", |
| [BTRFS_RAID_SINGLE] = "single", |
| [BTRFS_RAID_RAID5] = "raid5", |
| [BTRFS_RAID_RAID6] = "raid6", |
| }; |
| |
| static const char *get_raid_name(enum btrfs_raid_types type) |
| { |
| if (type >= BTRFS_NR_RAID_TYPES) |
| return NULL; |
| |
| return btrfs_raid_type_names[type]; |
| } |
| |
| enum btrfs_loop_type { |
| LOOP_CACHING_NOWAIT = 0, |
| LOOP_CACHING_WAIT = 1, |
| LOOP_ALLOC_CHUNK = 2, |
| LOOP_NO_EMPTY_SIZE = 3, |
| }; |
| |
| static inline void |
| btrfs_lock_block_group(struct btrfs_block_group_cache *cache, |
| int delalloc) |
| { |
| if (delalloc) |
| down_read(&cache->data_rwsem); |
| } |
| |
| static inline void |
| btrfs_grab_block_group(struct btrfs_block_group_cache *cache, |
| int delalloc) |
| { |
| btrfs_get_block_group(cache); |
| if (delalloc) |
| down_read(&cache->data_rwsem); |
| } |
| |
| static struct btrfs_block_group_cache * |
| btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, |
| struct btrfs_free_cluster *cluster, |
| int delalloc) |
| { |
| struct btrfs_block_group_cache *used_bg; |
| bool locked = false; |
| again: |
| spin_lock(&cluster->refill_lock); |
| if (locked) { |
| if (used_bg == cluster->block_group) |
| return used_bg; |
| |
| up_read(&used_bg->data_rwsem); |
| btrfs_put_block_group(used_bg); |
| } |
| |
| used_bg = cluster->block_group; |
| if (!used_bg) |
| return NULL; |
| |
| if (used_bg == block_group) |
| return used_bg; |
| |
| btrfs_get_block_group(used_bg); |
| |
| if (!delalloc) |
| return used_bg; |
| |
| if (down_read_trylock(&used_bg->data_rwsem)) |
| return used_bg; |
| |
| spin_unlock(&cluster->refill_lock); |
| down_read(&used_bg->data_rwsem); |
| locked = true; |
| goto again; |
| } |
| |
| static inline void |
| btrfs_release_block_group(struct btrfs_block_group_cache *cache, |
| int delalloc) |
| { |
| if (delalloc) |
| up_read(&cache->data_rwsem); |
| btrfs_put_block_group(cache); |
| } |
| |
| /* |
| * walks the btree of allocated extents and find a hole of a given size. |
| * The key ins is changed to record the hole: |
| * ins->objectid == start position |
| * ins->flags = BTRFS_EXTENT_ITEM_KEY |
| * ins->offset == the size of the hole. |
| * Any available blocks before search_start are skipped. |
| * |
| * If there is no suitable free space, we will record the max size of |
| * the free space extent currently. |
| */ |
| static noinline int find_free_extent(struct btrfs_root *orig_root, |
| u64 num_bytes, u64 empty_size, |
| u64 hint_byte, struct btrfs_key *ins, |
| u64 flags, int delalloc) |
| { |
| int ret = 0; |
| struct btrfs_root *root = orig_root->fs_info->extent_root; |
| struct btrfs_free_cluster *last_ptr = NULL; |
| struct btrfs_block_group_cache *block_group = NULL; |
| u64 search_start = 0; |
| u64 max_extent_size = 0; |
| int empty_cluster = 2 * 1024 * 1024; |
| struct btrfs_space_info *space_info; |
| int loop = 0; |
| int index = __get_raid_index(flags); |
| int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ? |
| RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC; |
| bool failed_cluster_refill = false; |
| bool failed_alloc = false; |
| bool use_cluster = true; |
| bool have_caching_bg = false; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| ins->type = BTRFS_EXTENT_ITEM_KEY; |
| ins->objectid = 0; |
| ins->offset = 0; |
| |
| trace_find_free_extent(orig_root, num_bytes, empty_size, flags); |
| |
| space_info = __find_space_info(root->fs_info, flags); |
| if (!space_info) { |
| btrfs_err(root->fs_info, "No space info for %llu", flags); |
| return -ENOSPC; |
| } |
| |
| /* |
| * If the space info is for both data and metadata it means we have a |
| * small filesystem and we can't use the clustering stuff. |
| */ |
| if (btrfs_mixed_space_info(space_info)) |
| use_cluster = false; |
| |
| if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) { |
| last_ptr = &root->fs_info->meta_alloc_cluster; |
| if (!btrfs_test_opt(root, SSD)) |
| empty_cluster = 64 * 1024; |
| } |
| |
| if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster && |
| btrfs_test_opt(root, SSD)) { |
| last_ptr = &root->fs_info->data_alloc_cluster; |
| } |
| |
| if (last_ptr) { |
| spin_lock(&last_ptr->lock); |
| if (last_ptr->block_group) |
| hint_byte = last_ptr->window_start; |
| spin_unlock(&last_ptr->lock); |
| } |
| |
| search_start = max(search_start, first_logical_byte(root, 0)); |
| search_start = max(search_start, hint_byte); |
| |
| if (!last_ptr) |
| empty_cluster = 0; |
| |
| if (search_start == hint_byte) { |
| block_group = btrfs_lookup_block_group(root->fs_info, |
| search_start); |
| /* |
| * we don't want to use the block group if it doesn't match our |
| * allocation bits, or if its not cached. |
| * |
| * However if we are re-searching with an ideal block group |
| * picked out then we don't care that the block group is cached. |
| */ |
| if (block_group && block_group_bits(block_group, flags) && |
| block_group->cached != BTRFS_CACHE_NO) { |
| down_read(&space_info->groups_sem); |
| if (list_empty(&block_group->list) || |
| block_group->ro) { |
| /* |
| * someone is removing this block group, |
| * we can't jump into the have_block_group |
| * target because our list pointers are not |
| * valid |
| */ |
| btrfs_put_block_group(block_group); |
| up_read(&space_info->groups_sem); |
| } else { |
| index = get_block_group_index(block_group); |
| btrfs_lock_block_group(block_group, delalloc); |
| goto have_block_group; |
| } |
| } else if (block_group) { |
| btrfs_put_block_group(block_group); |
| } |
| } |
| search: |
| have_caching_bg = false; |
| down_read(&space_info->groups_sem); |
| list_for_each_entry(block_group, &space_info->block_groups[index], |
| list) { |
| u64 offset; |
| int cached; |
| |
| btrfs_grab_block_group(block_group, delalloc); |
| search_start = block_group->key.objectid; |
| |
| /* |
| * this can happen if we end up cycling through all the |
| * raid types, but we want to make sure we only allocate |
| * for the proper type. |
| */ |
| if (!block_group_bits(block_group, flags)) { |
| u64 extra = BTRFS_BLOCK_GROUP_DUP | |
| BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID5 | |
| BTRFS_BLOCK_GROUP_RAID6 | |
| BTRFS_BLOCK_GROUP_RAID10; |
| |
| /* |
| * if they asked for extra copies and this block group |
| * doesn't provide them, bail. This does allow us to |
| * fill raid0 from raid1. |
| */ |
| if ((flags & extra) && !(block_group->flags & extra)) |
| goto loop; |
| } |
| |
| have_block_group: |
| cached = block_group_cache_done(block_group); |
| if (unlikely(!cached)) { |
| ret = cache_block_group(block_group, 0); |
| BUG_ON(ret < 0); |
| ret = 0; |
| } |
| |
| if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) |
| goto loop; |
| if (unlikely(block_group->ro)) |
| goto loop; |
| |
| /* |
| * Ok we want to try and use the cluster allocator, so |
| * lets look there |
| */ |
| if (last_ptr) { |
| struct btrfs_block_group_cache *used_block_group; |
| unsigned long aligned_cluster; |
| /* |
| * the refill lock keeps out other |
| * people trying to start a new cluster |
| */ |
| used_block_group = btrfs_lock_cluster(block_group, |
| last_ptr, |
| delalloc); |
| if (!used_block_group) |
| goto refill_cluster; |
| |
| if (used_block_group != block_group && |
| (used_block_group->ro || |
| !block_group_bits(used_block_group, flags))) |
| goto release_cluster; |
| |
| offset = btrfs_alloc_from_cluster(used_block_group, |
| last_ptr, |
| num_bytes, |
| used_block_group->key.objectid, |
| &max_extent_size); |
| if (offset) { |
| /* we have a block, we're done */ |
| spin_unlock(&last_ptr->refill_lock); |
| trace_btrfs_reserve_extent_cluster(root, |
| used_block_group, |
| search_start, num_bytes); |
| if (used_block_group != block_group) { |
| btrfs_release_block_group(block_group, |
| delalloc); |
| block_group = used_block_group; |
| } |
| goto checks; |
| } |
| |
| WARN_ON(last_ptr->block_group != used_block_group); |
| release_cluster: |
| /* If we are on LOOP_NO_EMPTY_SIZE, we can't |
| * set up a new clusters, so lets just skip it |
| * and let the allocator find whatever block |
| * it can find. If we reach this point, we |
| * will have tried the cluster allocator |
| * plenty of times and not have found |
| * anything, so we are likely way too |
| * fragmented for the clustering stuff to find |
| * anything. |
| * |
| * However, if the cluster is taken from the |
| * current block group, release the cluster |
| * first, so that we stand a better chance of |
| * succeeding in the unclustered |
| * allocation. */ |
| if (loop >= LOOP_NO_EMPTY_SIZE && |
| used_block_group != block_group) { |
| spin_unlock(&last_ptr->refill_lock); |
| btrfs_release_block_group(used_block_group, |
| delalloc); |
| goto unclustered_alloc; |
| } |
| |
| /* |
| * this cluster didn't work out, free it and |
| * start over |
| */ |
| btrfs_return_cluster_to_free_space(NULL, last_ptr); |
| |
| if (used_block_group != block_group) |
| btrfs_release_block_group(used_block_group, |
| delalloc); |
| refill_cluster: |
| if (loop >= LOOP_NO_EMPTY_SIZE) { |
| spin_unlock(&last_ptr->refill_lock); |
| goto unclustered_alloc; |
| } |
| |
| aligned_cluster = max_t(unsigned long, |
| empty_cluster + empty_size, |
| block_group->full_stripe_len); |
| |
| /* allocate a cluster in this block group */ |
| ret = btrfs_find_space_cluster(root, block_group, |
| last_ptr, search_start, |
| num_bytes, |
| aligned_cluster); |
| if (ret == 0) { |
| /* |
| * now pull our allocation out of this |
| * cluster |
| */ |
| offset = btrfs_alloc_from_cluster(block_group, |
| last_ptr, |
| num_bytes, |
| search_start, |
| &max_extent_size); |
| if (offset) { |
| /* we found one, proceed */ |
| spin_unlock(&last_ptr->refill_lock); |
| trace_btrfs_reserve_extent_cluster(root, |
| block_group, search_start, |
| num_bytes); |
| goto checks; |
| } |
| } else if (!cached && loop > LOOP_CACHING_NOWAIT |
| && !failed_cluster_refill) { |
| spin_unlock(&last_ptr->refill_lock); |
| |
| failed_cluster_refill = true; |
| wait_block_group_cache_progress(block_group, |
| num_bytes + empty_cluster + empty_size); |
| goto have_block_group; |
| } |
| |
| /* |
| * at this point we either didn't find a cluster |
| * or we weren't able to allocate a block from our |
| * cluster. Free the cluster we've been trying |
| * to use, and go to the next block group |
| */ |
| btrfs_return_cluster_to_free_space(NULL, last_ptr); |
| spin_unlock(&last_ptr->refill_lock); |
| goto loop; |
| } |
| |
| unclustered_alloc: |
| spin_lock(&block_group->free_space_ctl->tree_lock); |
| if (cached && |
| block_group->free_space_ctl->free_space < |
| num_bytes + empty_cluster + empty_size) { |
| if (block_group->free_space_ctl->free_space > |
| max_extent_size) |
| max_extent_size = |
| block_group->free_space_ctl->free_space; |
| spin_unlock(&block_group->free_space_ctl->tree_lock); |
| goto loop; |
| } |
| spin_unlock(&block_group->free_space_ctl->tree_lock); |
| |
| offset = btrfs_find_space_for_alloc(block_group, search_start, |
| num_bytes, empty_size, |
| &max_extent_size); |
| /* |
| * If we didn't find a chunk, and we haven't failed on this |
| * block group before, and this block group is in the middle of |
| * caching and we are ok with waiting, then go ahead and wait |
| * for progress to be made, and set failed_alloc to true. |
| * |
| * If failed_alloc is true then we've already waited on this |
| * block group once and should move on to the next block group. |
| */ |
| if (!offset && !failed_alloc && !cached && |
| loop > LOOP_CACHING_NOWAIT) { |
| wait_block_group_cache_progress(block_group, |
| num_bytes + empty_size); |
| failed_alloc = true; |
| goto have_block_group; |
| } else if (!offset) { |
| if (!cached) |
| have_caching_bg = true; |
| goto loop; |
| } |
| checks: |
| search_start = ALIGN(offset, root->stripesize); |
| |
| /* move on to the next group */ |
| if (search_start + num_bytes > |
| block_group->key.objectid + block_group->key.offset) { |
| btrfs_add_free_space(block_group, offset, num_bytes); |
| goto loop; |
| } |
| |
| if (offset < search_start) |
| btrfs_add_free_space(block_group, offset, |
| search_start - offset); |
| BUG_ON(offset > search_start); |
| |
| ret = btrfs_update_reserved_bytes(block_group, num_bytes, |
| alloc_type, delalloc); |
| if (ret == -EAGAIN) { |
| btrfs_add_free_space(block_group, offset, num_bytes); |
| goto loop; |
| } |
| |
| /* we are all good, lets return */ |
| ins->objectid = search_start; |
| ins->offset = num_bytes; |
| |
| trace_btrfs_reserve_extent(orig_root, block_group, |
| search_start, num_bytes); |
| btrfs_release_block_group(block_group, delalloc); |
| break; |
| loop: |
| failed_cluster_refill = false; |
| failed_alloc = false; |
| BUG_ON(index != get_block_group_index(block_group)); |
| btrfs_release_block_group(block_group, delalloc); |
| } |
| up_read(&space_info->groups_sem); |
| |
| if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg) |
| goto search; |
| |
| if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES) |
| goto search; |
| |
| /* |
| * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking |
| * caching kthreads as we move along |
| * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching |
| * LOOP_ALLOC_CHUNK, force a chunk allocation and try again |
| * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try |
| * again |
| */ |
| if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE) { |
| index = 0; |
| loop++; |
| if (loop == LOOP_ALLOC_CHUNK) { |
| struct btrfs_trans_handle *trans; |
| int exist = 0; |
| |
| trans = current->journal_info; |
| if (trans) |
| exist = 1; |
| else |
| trans = btrfs_join_transaction(root); |
| |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| goto out; |
| } |
| |
| ret = do_chunk_alloc(trans, root, flags, |
| CHUNK_ALLOC_FORCE); |
| /* |
| * Do not bail out on ENOSPC since we |
| * can do more things. |
| */ |
| if (ret < 0 && ret != -ENOSPC) |
| btrfs_abort_transaction(trans, |
| root, ret); |
| else |
| ret = 0; |
| if (!exist) |
| btrfs_end_transaction(trans, root); |
| if (ret) |
| goto out; |
| } |
| |
| if (loop == LOOP_NO_EMPTY_SIZE) { |
| empty_size = 0; |
| empty_cluster = 0; |
| } |
| |
| goto search; |
| } else if (!ins->objectid) { |
| ret = -ENOSPC; |
| } else if (ins->objectid) { |
| ret = 0; |
| } |
| out: |
| if (ret == -ENOSPC) |
| ins->offset = max_extent_size; |
| return ret; |
| } |
| |
| static void dump_space_info(struct btrfs_space_info *info, u64 bytes, |
| int dump_block_groups) |
| { |
| struct btrfs_block_group_cache *cache; |
| int index = 0; |
| |
| spin_lock(&info->lock); |
| printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n", |
| info->flags, |
| info->total_bytes - info->bytes_used - info->bytes_pinned - |
| info->bytes_reserved - info->bytes_readonly, |
| (info->full) ? "" : "not "); |
| printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, " |
| "reserved=%llu, may_use=%llu, readonly=%llu\n", |
| info->total_bytes, info->bytes_used, info->bytes_pinned, |
| info->bytes_reserved, info->bytes_may_use, |
| info->bytes_readonly); |
| spin_unlock(&info->lock); |
| |
| if (!dump_block_groups) |
| return; |
| |
| down_read(&info->groups_sem); |
| again: |
| list_for_each_entry(cache, &info->block_groups[index], list) { |
| spin_lock(&cache->lock); |
| printk(KERN_INFO "BTRFS: " |
| "block group %llu has %llu bytes, " |
| "%llu used %llu pinned %llu reserved %s\n", |
| cache->key.objectid, cache->key.offset, |
| btrfs_block_group_used(&cache->item), cache->pinned, |
| cache->reserved, cache->ro ? "[readonly]" : ""); |
| btrfs_dump_free_space(cache, bytes); |
| spin_unlock(&cache->lock); |
| } |
| if (++index < BTRFS_NR_RAID_TYPES) |
| goto again; |
| up_read(&info->groups_sem); |
| } |
| |
| int btrfs_reserve_extent(struct btrfs_root *root, |
| u64 num_bytes, u64 min_alloc_size, |
| u64 empty_size, u64 hint_byte, |
| struct btrfs_key *ins, int is_data, int delalloc) |
| { |
| bool final_tried = false; |
| u64 flags; |
| int ret; |
| |
| flags = btrfs_get_alloc_profile(root, is_data); |
| again: |
| WARN_ON(num_bytes < root->sectorsize); |
| ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins, |
| flags, delalloc); |
| |
| if (ret == -ENOSPC) { |
| if (!final_tried && ins->offset) { |
| num_bytes = min(num_bytes >> 1, ins->offset); |
| num_bytes = round_down(num_bytes, root->sectorsize); |
| num_bytes = max(num_bytes, min_alloc_size); |
| if (num_bytes == min_alloc_size) |
| final_tried = true; |
| goto again; |
| } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) { |
| struct btrfs_space_info *sinfo; |
| |
| sinfo = __find_space_info(root->fs_info, flags); |
| btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu", |
| flags, num_bytes); |
| if (sinfo) |
| dump_space_info(sinfo, num_bytes, 1); |
| } |
| } |
| |
| return ret; |
| } |
| |
| static int __btrfs_free_reserved_extent(struct btrfs_root *root, |
| u64 start, u64 len, |
| int pin, int delalloc) |
| { |
| struct btrfs_block_group_cache *cache; |
| int ret = 0; |
| |
| cache = btrfs_lookup_block_group(root->fs_info, start); |
| if (!cache) { |
| btrfs_err(root->fs_info, "Unable to find block group for %llu", |
| start); |
| return -ENOSPC; |
| } |
| |
| if (pin) |
| pin_down_extent(root, cache, start, len, 1); |
| else { |
| if (btrfs_test_opt(root, DISCARD)) |
| ret = btrfs_discard_extent(root, start, len, NULL); |
| btrfs_add_free_space(cache, start, len); |
| btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc); |
| } |
| |
| btrfs_put_block_group(cache); |
| |
| trace_btrfs_reserved_extent_free(root, start, len); |
| |
| return ret; |
| } |
| |
| int btrfs_free_reserved_extent(struct btrfs_root *root, |
| u64 start, u64 len, int delalloc) |
| { |
| return __btrfs_free_reserved_extent(root, start, len, 0, delalloc); |
| } |
| |
| int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root, |
| u64 start, u64 len) |
| { |
| return __btrfs_free_reserved_extent(root, start, len, 1, 0); |
| } |
| |
| static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 parent, u64 root_objectid, |
| u64 flags, u64 owner, u64 offset, |
| struct btrfs_key *ins, int ref_mod) |
| { |
| int ret; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_extent_item *extent_item; |
| struct btrfs_extent_inline_ref *iref; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| int type; |
| u32 size; |
| |
| if (parent > 0) |
| type = BTRFS_SHARED_DATA_REF_KEY; |
| else |
| type = BTRFS_EXTENT_DATA_REF_KEY; |
| |
| size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->leave_spinning = 1; |
| ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, |
| ins, size); |
| if (ret) { |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| leaf = path->nodes[0]; |
| extent_item = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_item); |
| btrfs_set_extent_refs(leaf, extent_item, ref_mod); |
| btrfs_set_extent_generation(leaf, extent_item, trans->transid); |
| btrfs_set_extent_flags(leaf, extent_item, |
| flags | BTRFS_EXTENT_FLAG_DATA); |
| |
| iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); |
| btrfs_set_extent_inline_ref_type(leaf, iref, type); |
| if (parent > 0) { |
| struct btrfs_shared_data_ref *ref; |
| ref = (struct btrfs_shared_data_ref *)(iref + 1); |
| btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| btrfs_set_shared_data_ref_count(leaf, ref, ref_mod); |
| } else { |
| struct btrfs_extent_data_ref *ref; |
| ref = (struct btrfs_extent_data_ref *)(&iref->offset); |
| btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); |
| btrfs_set_extent_data_ref_objectid(leaf, ref, owner); |
| btrfs_set_extent_data_ref_offset(leaf, ref, offset); |
| btrfs_set_extent_data_ref_count(leaf, ref, ref_mod); |
| } |
| |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| btrfs_free_path(path); |
| |
| ret = update_block_group(trans, root, ins->objectid, ins->offset, 1); |
| if (ret) { /* -ENOENT, logic error */ |
| btrfs_err(fs_info, "update block group failed for %llu %llu", |
| ins->objectid, ins->offset); |
| BUG(); |
| } |
| trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset); |
| return ret; |
| } |
| |
| static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 parent, u64 root_objectid, |
| u64 flags, struct btrfs_disk_key *key, |
| int level, struct btrfs_key *ins, |
| int no_quota) |
| { |
| int ret; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_extent_item *extent_item; |
| struct btrfs_tree_block_info *block_info; |
| struct btrfs_extent_inline_ref *iref; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| u32 size = sizeof(*extent_item) + sizeof(*iref); |
| u64 num_bytes = ins->offset; |
| bool skinny_metadata = btrfs_fs_incompat(root->fs_info, |
| SKINNY_METADATA); |
| |
| if (!skinny_metadata) |
| size += sizeof(*block_info); |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| btrfs_free_and_pin_reserved_extent(root, ins->objectid, |
| root->nodesize); |
| return -ENOMEM; |
| } |
| |
| path->leave_spinning = 1; |
| ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, |
| ins, size); |
| if (ret) { |
| btrfs_free_path(path); |
| btrfs_free_and_pin_reserved_extent(root, ins->objectid, |
| root->nodesize); |
| return ret; |
| } |
| |
| leaf = path->nodes[0]; |
| extent_item = btrfs_item_ptr(leaf, path->slots[0], |
| struct btrfs_extent_item); |
| btrfs_set_extent_refs(leaf, extent_item, 1); |
| btrfs_set_extent_generation(leaf, extent_item, trans->transid); |
| btrfs_set_extent_flags(leaf, extent_item, |
| flags | BTRFS_EXTENT_FLAG_TREE_BLOCK); |
| |
| if (skinny_metadata) { |
| iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); |
| num_bytes = root->nodesize; |
| } else { |
| block_info = (struct btrfs_tree_block_info *)(extent_item + 1); |
| btrfs_set_tree_block_key(leaf, block_info, key); |
| btrfs_set_tree_block_level(leaf, block_info, level); |
| iref = (struct btrfs_extent_inline_ref *)(block_info + 1); |
| } |
| |
| if (parent > 0) { |
| BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); |
| btrfs_set_extent_inline_ref_type(leaf, iref, |
| BTRFS_SHARED_BLOCK_REF_KEY); |
| btrfs_set_extent_inline_ref_offset(leaf, iref, parent); |
| } else { |
| btrfs_set_extent_inline_ref_type(leaf, iref, |
| BTRFS_TREE_BLOCK_REF_KEY); |
| btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); |
| } |
| |
| btrfs_mark_buffer_dirty(leaf); |
| btrfs_free_path(path); |
| |
| ret = update_block_group(trans, root, ins->objectid, root->nodesize, |
| 1); |
| if (ret) { /* -ENOENT, logic error */ |
| btrfs_err(fs_info, "update block group failed for %llu %llu", |
| ins->objectid, ins->offset); |
| BUG(); |
| } |
| |
| trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize); |
| return ret; |
| } |
| |
| int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 root_objectid, u64 owner, |
| u64 offset, struct btrfs_key *ins) |
| { |
| int ret; |
| |
| BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID); |
| |
| ret = btrfs_add_delayed_data_ref(root->fs_info, trans, ins->objectid, |
| ins->offset, 0, |
| root_objectid, owner, offset, |
| BTRFS_ADD_DELAYED_EXTENT, NULL, 0); |
| return ret; |
| } |
| |
| /* |
| * this is used by the tree logging recovery code. It records that |
| * an extent has been allocated and makes sure to clear the free |
| * space cache bits as well |
| */ |
| int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 root_objectid, u64 owner, u64 offset, |
| struct btrfs_key *ins) |
| { |
| int ret; |
| struct btrfs_block_group_cache *block_group; |
| |
| /* |
| * Mixed block groups will exclude before processing the log so we only |
| * need to do the exlude dance if this fs isn't mixed. |
| */ |
| if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) { |
| ret = __exclude_logged_extent(root, ins->objectid, ins->offset); |
| if (ret) |
| return ret; |
| } |
| |
| block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); |
| if (!block_group) |
| return -EINVAL; |
| |
| ret = btrfs_update_reserved_bytes(block_group, ins->offset, |
| RESERVE_ALLOC_NO_ACCOUNT, 0); |
| BUG_ON(ret); /* logic error */ |
| ret = alloc_reserved_file_extent(trans, root, 0, root_objectid, |
| 0, owner, offset, ins, 1); |
| btrfs_put_block_group(block_group); |
| return ret; |
| } |
| |
| static struct extent_buffer * |
| btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| u64 bytenr, int level) |
| { |
| struct extent_buffer *buf; |
| |
| buf = btrfs_find_create_tree_block(root, bytenr); |
| if (!buf) |
| return ERR_PTR(-ENOMEM); |
| btrfs_set_header_generation(buf, trans->transid); |
| btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level); |
| btrfs_tree_lock(buf); |
| clean_tree_block(trans, root->fs_info, buf); |
| clear_bit(EXTENT_BUFFER_STALE, &buf->bflags); |
| |
| btrfs_set_lock_blocking(buf); |
| btrfs_set_buffer_uptodate(buf); |
| |
| if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { |
| buf->log_index = root->log_transid % 2; |
| /* |
| * we allow two log transactions at a time, use different |
| * EXENT bit to differentiate dirty pages. |
| */ |
| if (buf->log_index == 0) |
| set_extent_dirty(&root->dirty_log_pages, buf->start, |
| buf->start + buf->len - 1, GFP_NOFS); |
| else |
| set_extent_new(&root->dirty_log_pages, buf->start, |
| buf->start + buf->len - 1, GFP_NOFS); |
| } else { |
| buf->log_index = -1; |
| set_extent_dirty(&trans->transaction->dirty_pages, buf->start, |
| buf->start + buf->len - 1, GFP_NOFS); |
| } |
| trans->blocks_used++; |
| /* this returns a buffer locked for blocking */ |
| return buf; |
| } |
| |
| static struct btrfs_block_rsv * |
| use_block_rsv(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u32 blocksize) |
| { |
| struct btrfs_block_rsv *block_rsv; |
| struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; |
| int ret; |
| bool global_updated = false; |
| |
| block_rsv = get_block_rsv(trans, root); |
| |
| if (unlikely(block_rsv->size == 0)) |
| goto try_reserve; |
| again: |
| ret = block_rsv_use_bytes(block_rsv, blocksize); |
| if (!ret) |
| return block_rsv; |
| |
| if (block_rsv->failfast) |
| return ERR_PTR(ret); |
| |
| if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) { |
| global_updated = true; |
| update_global_block_rsv(root->fs_info); |
| goto again; |
| } |
| |
| if (btrfs_test_opt(root, ENOSPC_DEBUG)) { |
| static DEFINE_RATELIMIT_STATE(_rs, |
| DEFAULT_RATELIMIT_INTERVAL * 10, |
| /*DEFAULT_RATELIMIT_BURST*/ 1); |
| if (__ratelimit(&_rs)) |
| WARN(1, KERN_DEBUG |
| "BTRFS: block rsv returned %d\n", ret); |
| } |
| try_reserve: |
| ret = reserve_metadata_bytes(root, block_rsv, blocksize, |
| BTRFS_RESERVE_NO_FLUSH); |
| if (!ret) |
| return block_rsv; |
| /* |
| * If we couldn't reserve metadata bytes try and use some from |
| * the global reserve if its space type is the same as the global |
| * reservation. |
| */ |
| if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL && |
| block_rsv->space_info == global_rsv->space_info) { |
| ret = block_rsv_use_bytes(global_rsv, blocksize); |
| if (!ret) |
| return global_rsv; |
| } |
| return ERR_PTR(ret); |
| } |
| |
| static void unuse_block_rsv(struct btrfs_fs_info *fs_info, |
| struct btrfs_block_rsv *block_rsv, u32 blocksize) |
| { |
| block_rsv_add_bytes(block_rsv, blocksize, 0); |
| block_rsv_release_bytes(fs_info, block_rsv, NULL, 0); |
| } |
| |
| /* |
| * finds a free extent and does all the dirty work required for allocation |
| * returns the tree buffer or an ERR_PTR on error. |
| */ |
| struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 parent, u64 root_objectid, |
| struct btrfs_disk_key *key, int level, |
| u64 hint, u64 empty_size) |
| { |
| struct btrfs_key ins; |
| struct btrfs_block_rsv *block_rsv; |
| struct extent_buffer *buf; |
| struct btrfs_delayed_extent_op *extent_op; |
| u64 flags = 0; |
| int ret; |
| u32 blocksize = root->nodesize; |
| bool skinny_metadata = btrfs_fs_incompat(root->fs_info, |
| SKINNY_METADATA); |
| |
| if (btrfs_test_is_dummy_root(root)) { |
| buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr, |
| level); |
| if (!IS_ERR(buf)) |
| root->alloc_bytenr += blocksize; |
| return buf; |
| } |
| |
| block_rsv = use_block_rsv(trans, root, blocksize); |
| if (IS_ERR(block_rsv)) |
| return ERR_CAST(block_rsv); |
| |
| ret = btrfs_reserve_extent(root, blocksize, blocksize, |
| empty_size, hint, &ins, 0, 0); |
| if (ret) |
| goto out_unuse; |
| |
| buf = btrfs_init_new_buffer(trans, root, ins.objectid, level); |
| if (IS_ERR(buf)) { |
| ret = PTR_ERR(buf); |
| goto out_free_reserved; |
| } |
| |
| if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) { |
| if (parent == 0) |
| parent = ins.objectid; |
| flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| } else |
| BUG_ON(parent > 0); |
| |
| if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { |
| extent_op = btrfs_alloc_delayed_extent_op(); |
| if (!extent_op) { |
| ret = -ENOMEM; |
| goto out_free_buf; |
| } |
| if (key) |
| memcpy(&extent_op->key, key, sizeof(extent_op->key)); |
| else |
| memset(&extent_op->key, 0, sizeof(extent_op->key)); |
| extent_op->flags_to_set = flags; |
| if (skinny_metadata) |
| extent_op->update_key = 0; |
| else |
| extent_op->update_key = 1; |
| extent_op->update_flags = 1; |
| extent_op->is_data = 0; |
| extent_op->level = level; |
| |
| ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, |
| ins.objectid, ins.offset, |
| parent, root_objectid, level, |
| BTRFS_ADD_DELAYED_EXTENT, |
| extent_op, 0); |
| if (ret) |
| goto out_free_delayed; |
| } |
| return buf; |
| |
| out_free_delayed: |
| btrfs_free_delayed_extent_op(extent_op); |
| out_free_buf: |
| free_extent_buffer(buf); |
| out_free_reserved: |
| btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0); |
| out_unuse: |
| unuse_block_rsv(root->fs_info, block_rsv, blocksize); |
| return ERR_PTR(ret); |
| } |
| |
| struct walk_control { |
| u64 refs[BTRFS_MAX_LEVEL]; |
| u64 flags[BTRFS_MAX_LEVEL]; |
| struct btrfs_key update_progress; |
| int stage; |
| int level; |
| int shared_level; |
| int update_ref; |
| int keep_locks; |
| int reada_slot; |
| int reada_count; |
| int for_reloc; |
| }; |
| |
| #define DROP_REFERENCE 1 |
| #define UPDATE_BACKREF 2 |
| |
| static noinline void reada_walk_down(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct walk_control *wc, |
| struct btrfs_path *path) |
| { |
| u64 bytenr; |
| u64 generation; |
| u64 refs; |
| u64 flags; |
| u32 nritems; |
| u32 blocksize; |
| struct btrfs_key key; |
| struct extent_buffer *eb; |
| int ret; |
| int slot; |
| int nread = 0; |
| |
| if (path->slots[wc->level] < wc->reada_slot) { |
| wc->reada_count = wc->reada_count * 2 / 3; |
| wc->reada_count = max(wc->reada_count, 2); |
| } else { |
| wc->reada_count = wc->reada_count * 3 / 2; |
| wc->reada_count = min_t(int, wc->reada_count, |
| BTRFS_NODEPTRS_PER_BLOCK(root)); |
| } |
| |
| eb = path->nodes[wc->level]; |
| nritems = btrfs_header_nritems(eb); |
| blocksize = root->nodesize; |
| |
| for (slot = path->slots[wc->level]; slot < nritems; slot++) { |
| if (nread >= wc->reada_count) |
| break; |
| |
| cond_resched(); |
| bytenr = btrfs_node_blockptr(eb, slot); |
| generation = btrfs_node_ptr_generation(eb, slot); |
| |
| if (slot == path->slots[wc->level]) |
| goto reada; |
| |
| if (wc->stage == UPDATE_BACKREF && |
| generation <= root->root_key.offset) |
| continue; |
| |
| /* We don't lock the tree block, it's OK to be racy here */ |
| ret = btrfs_lookup_extent_info(trans, root, bytenr, |
| wc->level - 1, 1, &refs, |
| &flags); |
| /* We don't care about errors in readahead. */ |
| if (ret < 0) |
| continue; |
| BUG_ON(refs == 0); |
| |
| if (wc->stage == DROP_REFERENCE) { |
| if (refs == 1) |
| goto reada; |
| |
| if (wc->level == 1 && |
| (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| continue; |
| if (!wc->update_ref || |
| generation <= root->root_key.offset) |
| continue; |
| btrfs_node_key_to_cpu(eb, &key, slot); |
| ret = btrfs_comp_cpu_keys(&key, |
| &wc->update_progress); |
| if (ret < 0) |
| continue; |
| } else { |
| if (wc->level == 1 && |
| (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| continue; |
| } |
| reada: |
| readahead_tree_block(root, bytenr); |
| nread++; |
| } |
| wc->reada_slot = slot; |
| } |
| |
| /* |
| * TODO: Modify related function to add related node/leaf to dirty_extent_root, |
| * for later qgroup accounting. |
| * |
| * Current, this function does nothing. |
| */ |
| static int account_leaf_items(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *eb) |
| { |
| int nr = btrfs_header_nritems(eb); |
| int i, extent_type; |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| u64 bytenr, num_bytes; |
| |
| for (i = 0; i < nr; i++) { |
| btrfs_item_key_to_cpu(eb, &key, i); |
| |
| if (key.type != BTRFS_EXTENT_DATA_KEY) |
| continue; |
| |
| fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); |
| /* filter out non qgroup-accountable extents */ |
| extent_type = btrfs_file_extent_type(eb, fi); |
| |
| if (extent_type == BTRFS_FILE_EXTENT_INLINE) |
| continue; |
| |
| bytenr = btrfs_file_extent_disk_bytenr(eb, fi); |
| if (!bytenr) |
| continue; |
| |
| num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi); |
| } |
| return 0; |
| } |
| |
| /* |
| * Walk up the tree from the bottom, freeing leaves and any interior |
| * nodes which have had all slots visited. If a node (leaf or |
| * interior) is freed, the node above it will have it's slot |
| * incremented. The root node will never be freed. |
| * |
| * At the end of this function, we should have a path which has all |
| * slots incremented to the next position for a search. If we need to |
| * read a new node it will be NULL and the node above it will have the |
| * correct slot selected for a later read. |
| * |
| * If we increment the root nodes slot counter past the number of |
| * elements, 1 is returned to signal completion of the search. |
| */ |
| static int adjust_slots_upwards(struct btrfs_root *root, |
| struct btrfs_path *path, int root_level) |
| { |
| int level = 0; |
| int nr, slot; |
| struct extent_buffer *eb; |
| |
| if (root_level == 0) |
| return 1; |
| |
| while (level <= root_level) { |
| eb = path->nodes[level]; |
| nr = btrfs_header_nritems(eb); |
| path->slots[level]++; |
| slot = path->slots[level]; |
| if (slot >= nr || level == 0) { |
| /* |
| * Don't free the root - we will detect this |
| * condition after our loop and return a |
| * positive value for caller to stop walking the tree. |
| */ |
| if (level != root_level) { |
| btrfs_tree_unlock_rw(eb, path->locks[level]); |
| path->locks[level] = 0; |
| |
| free_extent_buffer(eb); |
| path->nodes[level] = NULL; |
| path->slots[level] = 0; |
| } |
| } else { |
| /* |
| * We have a valid slot to walk back down |
| * from. Stop here so caller can process these |
| * new nodes. |
| */ |
| break; |
| } |
| |
| level++; |
| } |
| |
| eb = path->nodes[root_level]; |
| if (path->slots[root_level] >= btrfs_header_nritems(eb)) |
| return 1; |
| |
| return 0; |
| } |
| |
| /* |
| * root_eb is the subtree root and is locked before this function is called. |
| * TODO: Modify this function to mark all (including complete shared node) |
| * to dirty_extent_root to allow it get accounted in qgroup. |
| */ |
| static int account_shared_subtree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *root_eb, |
| u64 root_gen, |
| int root_level) |
| { |
| int ret = 0; |
| int level; |
| struct extent_buffer *eb = root_eb; |
| struct btrfs_path *path = NULL; |
| |
| BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL); |
| BUG_ON(root_eb == NULL); |
| |
| if (!root->fs_info->quota_enabled) |
| return 0; |
| |
| if (!extent_buffer_uptodate(root_eb)) { |
| ret = btrfs_read_buffer(root_eb, root_gen); |
| if (ret) |
| goto out; |
| } |
| |
| if (root_level == 0) { |
| ret = account_leaf_items(trans, root, root_eb); |
| goto out; |
| } |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| /* |
| * Walk down the tree. Missing extent blocks are filled in as |
| * we go. Metadata is accounted every time we read a new |
| * extent block. |
| * |
| * When we reach a leaf, we account for file extent items in it, |
| * walk back up the tree (adjusting slot pointers as we go) |
| * and restart the search process. |
| */ |
| extent_buffer_get(root_eb); /* For path */ |
| path->nodes[root_level] = root_eb; |
| path->slots[root_level] = 0; |
| path->locks[root_level] = 0; /* so release_path doesn't try to unlock */ |
| walk_down: |
| level = root_level; |
| while (level >= 0) { |
| if (path->nodes[level] == NULL) { |
| int parent_slot; |
| u64 child_gen; |
| u64 child_bytenr; |
| |
| /* We need to get child blockptr/gen from |
| * parent before we can read it. */ |
| eb = path->nodes[level + 1]; |
| parent_slot = path->slots[level + 1]; |
| child_bytenr = btrfs_node_blockptr(eb, parent_slot); |
| child_gen = btrfs_node_ptr_generation(eb, parent_slot); |
| |
| eb = read_tree_block(root, child_bytenr, child_gen); |
| if (IS_ERR(eb)) { |
| ret = PTR_ERR(eb); |
| goto out; |
| } else if (!extent_buffer_uptodate(eb)) { |
| free_extent_buffer(eb); |
| ret = -EIO; |
| goto out; |
| } |
| |
| path->nodes[level] = eb; |
| path->slots[level] = 0; |
| |
| btrfs_tree_read_lock(eb); |
| btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); |
| path->locks[level] = BTRFS_READ_LOCK_BLOCKING; |
| } |
| |
| if (level == 0) { |
| ret = account_leaf_items(trans, root, path->nodes[level]); |
| if (ret) |
| goto out; |
| |
| /* Nonzero return here means we completed our search */ |
| ret = adjust_slots_upwards(root, path, root_level); |
| if (ret) |
| break; |
| |
| /* Restart search with new slots */ |
| goto walk_down; |
| } |
| |
| level--; |
| } |
| |
| ret = 0; |
| out: |
| btrfs_free_path(path); |
| |
| return ret; |
| } |
| |
| /* |
| * helper to process tree block while walking down the tree. |
| * |
| * when wc->stage == UPDATE_BACKREF, this function updates |
| * back refs for pointers in the block. |
| * |
| * NOTE: return value 1 means we should stop walking down. |
| */ |
| static noinline int walk_down_proc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct walk_control *wc, int lookup_info) |
| { |
| int level = wc->level; |
| struct extent_buffer *eb = path->nodes[level]; |
| u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| int ret; |
| |
| if (wc->stage == UPDATE_BACKREF && |
| btrfs_header_owner(eb) != root->root_key.objectid) |
| return 1; |
| |
| /* |
| * when reference count of tree block is 1, it won't increase |
| * again. once full backref flag is set, we never clear it. |
| */ |
| if (lookup_info && |
| ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || |
| (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) { |
| BUG_ON(!path->locks[level]); |
| ret = btrfs_lookup_extent_info(trans, root, |
| eb->start, level, 1, |
| &wc->refs[level], |
| &wc->flags[level]); |
| BUG_ON(ret == -ENOMEM); |
| if (ret) |
| return ret; |
| BUG_ON(wc->refs[level] == 0); |
| } |
| |
| if (wc->stage == DROP_REFERENCE) { |
| if (wc->refs[level] > 1) |
| return 1; |
| |
| if (path->locks[level] && !wc->keep_locks) { |
| btrfs_tree_unlock_rw(eb, path->locks[level]); |
| path->locks[level] = 0; |
| } |
| return 0; |
| } |
| |
| /* wc->stage == UPDATE_BACKREF */ |
| if (!(wc->flags[level] & flag)) { |
| BUG_ON(!path->locks[level]); |
| ret = btrfs_inc_ref(trans, root, eb, 1); |
| BUG_ON(ret); /* -ENOMEM */ |
| ret = btrfs_dec_ref(trans, root, eb, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| ret = btrfs_set_disk_extent_flags(trans, root, eb->start, |
| eb->len, flag, |
| btrfs_header_level(eb), 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| wc->flags[level] |= flag; |
| } |
| |
| /* |
| * the block is shared by multiple trees, so it's not good to |
| * keep the tree lock |
| */ |
| if (path->locks[level] && level > 0) { |
| btrfs_tree_unlock_rw(eb, path->locks[level]); |
| path->locks[level] = 0; |
| } |
| return 0; |
| } |
| |
| /* |
| * helper to process tree block pointer. |
| * |
| * when wc->stage == DROP_REFERENCE, this function checks |
| * reference count of the block pointed to. if the block |
| * is shared and we need update back refs for the subtree |
| * rooted at the block, this function changes wc->stage to |
| * UPDATE_BACKREF. if the block is shared and there is no |
| * need to update back, this function drops the reference |
| * to the block. |
| * |
| * NOTE: return value 1 means we should stop walking down. |
| */ |
| static noinline int do_walk_down(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct walk_control *wc, int *lookup_info) |
| { |
| u64 bytenr; |
| u64 generation; |
| u64 parent; |
| u32 blocksize; |
| struct btrfs_key key; |
| struct extent_buffer *next; |
| int level = wc->level; |
| int reada = 0; |
| int ret = 0; |
| bool need_account = false; |
| |
| generation = btrfs_node_ptr_generation(path->nodes[level], |
| path->slots[level]); |
| /* |
| * if the lower level block was created before the snapshot |
| * was created, we know there is no need to update back refs |
| * for the subtree |
| */ |
| if (wc->stage == UPDATE_BACKREF && |
| generation <= root->root_key.offset) { |
| *lookup_info = 1; |
| return 1; |
| } |
| |
| bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); |
| blocksize = root->nodesize; |
| |
| next = btrfs_find_tree_block(root->fs_info, bytenr); |
| if (!next) { |
| next = btrfs_find_create_tree_block(root, bytenr); |
| if (!next) |
| return -ENOMEM; |
| btrfs_set_buffer_lockdep_class(root->root_key.objectid, next, |
| level - 1); |
| reada = 1; |
| } |
| btrfs_tree_lock(next); |
| btrfs_set_lock_blocking(next); |
| |
| ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1, |
| &wc->refs[level - 1], |
| &wc->flags[level - 1]); |
| if (ret < 0) { |
| btrfs_tree_unlock(next); |
| return ret; |
| } |
| |
| if (unlikely(wc->refs[level - 1] == 0)) { |
| btrfs_err(root->fs_info, "Missing references."); |
| BUG(); |
| } |
| *lookup_info = 0; |
| |
| if (wc->stage == DROP_REFERENCE) { |
| if (wc->refs[level - 1] > 1) { |
| need_account = true; |
| if (level == 1 && |
| (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| goto skip; |
| |
| if (!wc->update_ref || |
| generation <= root->root_key.offset) |
| goto skip; |
| |
| btrfs_node_key_to_cpu(path->nodes[level], &key, |
| path->slots[level]); |
| ret = btrfs_comp_cpu_keys(&key, &wc->update_progress); |
| if (ret < 0) |
| goto skip; |
| |
| wc->stage = UPDATE_BACKREF; |
| wc->shared_level = level - 1; |
| } |
| } else { |
| if (level == 1 && |
| (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) |
| goto skip; |
| } |
| |
| if (!btrfs_buffer_uptodate(next, generation, 0)) { |
| btrfs_tree_unlock(next); |
| free_extent_buffer(next); |
| next = NULL; |
| *lookup_info = 1; |
| } |
| |
| if (!next) { |
| if (reada && level == 1) |
| reada_walk_down(trans, root, wc, path); |
| next = read_tree_block(root, bytenr, generation); |
| if (IS_ERR(next)) { |
| return PTR_ERR(next); |
| } else if (!extent_buffer_uptodate(next)) { |
| free_extent_buffer(next); |
| return -EIO; |
| } |
| btrfs_tree_lock(next); |
| btrfs_set_lock_blocking(next); |
| } |
| |
| level--; |
| BUG_ON(level != btrfs_header_level(next)); |
| path->nodes[level] = next; |
| path->slots[level] = 0; |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| wc->level = level; |
| if (wc->level == 1) |
| wc->reada_slot = 0; |
| return 0; |
| skip: |
| wc->refs[level - 1] = 0; |
| wc->flags[level - 1] = 0; |
| if (wc->stage == DROP_REFERENCE) { |
| if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { |
| parent = path->nodes[level]->start; |
| } else { |
| BUG_ON(root->root_key.objectid != |
| btrfs_header_owner(path->nodes[level])); |
| parent = 0; |
| } |
| |
| if (need_account) { |
| ret = account_shared_subtree(trans, root, next, |
| generation, level - 1); |
| if (ret) { |
| printk_ratelimited(KERN_ERR "BTRFS: %s Error " |
| "%d accounting shared subtree. Quota " |
| "is out of sync, rescan required.\n", |
| root->fs_info->sb->s_id, ret); |
| } |
| } |
| ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent, |
| root->root_key.objectid, level - 1, 0, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| } |
| btrfs_tree_unlock(next); |
| free_extent_buffer(next); |
| *lookup_info = 1; |
| return 1; |
| } |
| |
| /* |
| * helper to process tree block while walking up the tree. |
| * |
| * when wc->stage == DROP_REFERENCE, this function drops |
| * reference count on the block. |
| * |
| * when wc->stage == UPDATE_BACKREF, this function changes |
| * wc->stage back to DROP_REFERENCE if we changed wc->stage |
| * to UPDATE_BACKREF previously while processing the block. |
| * |
| * NOTE: return value 1 means we should stop walking up. |
| */ |
| static noinline int walk_up_proc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct walk_control *wc) |
| { |
| int ret; |
| int level = wc->level; |
| struct extent_buffer *eb = path->nodes[level]; |
| u64 parent = 0; |
| |
| if (wc->stage == UPDATE_BACKREF) { |
| BUG_ON(wc->shared_level < level); |
| if (level < wc->shared_level) |
| goto out; |
| |
| ret = find_next_key(path, level + 1, &wc->update_progress); |
| if (ret > 0) |
| wc->update_ref = 0; |
| |
| wc->stage = DROP_REFERENCE; |
| wc->shared_level = -1; |
| path->slots[level] = 0; |
| |
| /* |
| * check reference count again if the block isn't locked. |
| * we should start walking down the tree again if reference |
| * count is one. |
| */ |
| if (!path->locks[level]) { |
| BUG_ON(level == 0); |
| btrfs_tree_lock(eb); |
| btrfs_set_lock_blocking(eb); |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| |
| ret = btrfs_lookup_extent_info(trans, root, |
| eb->start, level, 1, |
| &wc->refs[level], |
| &wc->flags[level]); |
| if (ret < 0) { |
| btrfs_tree_unlock_rw(eb, path->locks[level]); |
| path->locks[level] = 0; |
| return ret; |
| } |
| BUG_ON(wc->refs[level] == 0); |
| if (wc->refs[level] == 1) { |
| btrfs_tree_unlock_rw(eb, path->locks[level]); |
| path->locks[level] = 0; |
| return 1; |
| } |
| } |
| } |
| |
| /* wc->stage == DROP_REFERENCE */ |
| BUG_ON(wc->refs[level] > 1 && !path->locks[level]); |
| |
| if (wc->refs[level] == 1) { |
| if (level == 0) { |
| if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| ret = btrfs_dec_ref(trans, root, eb, 1); |
| else |
| ret = btrfs_dec_ref(trans, root, eb, 0); |
| BUG_ON(ret); /* -ENOMEM */ |
| ret = account_leaf_items(trans, root, eb); |
| if (ret) { |
| printk_ratelimited(KERN_ERR "BTRFS: %s Error " |
| "%d accounting leaf items. Quota " |
| "is out of sync, rescan required.\n", |
| root->fs_info->sb->s_id, ret); |
| } |
| } |
| /* make block locked assertion in clean_tree_block happy */ |
| if (!path->locks[level] && |
| btrfs_header_generation(eb) == trans->transid) { |
| btrfs_tree_lock(eb); |
| btrfs_set_lock_blocking(eb); |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| } |
| clean_tree_block(trans, root->fs_info, eb); |
| } |
| |
| if (eb == root->node) { |
| if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| parent = eb->start; |
| else |
| BUG_ON(root->root_key.objectid != |
| btrfs_header_owner(eb)); |
| } else { |
| if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF) |
| parent = path->nodes[level + 1]->start; |
| else |
| BUG_ON(root->root_key.objectid != |
| btrfs_header_owner(path->nodes[level + 1])); |
| } |
| |
| btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1); |
| out: |
| wc->refs[level] = 0; |
| wc->flags[level] = 0; |
| return 0; |
| } |
| |
| static noinline int walk_down_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct walk_control *wc) |
| { |
| int level = wc->level; |
| int lookup_info = 1; |
| int ret; |
| |
| while (level >= 0) { |
| ret = walk_down_proc(trans, root, path, wc, lookup_info); |
| if (ret > 0) |
| break; |
| |
| if (level == 0) |
| break; |
| |
| if (path->slots[level] >= |
| btrfs_header_nritems(path->nodes[level])) |
| break; |
| |
| ret = do_walk_down(trans, root, path, wc, &lookup_info); |
| if (ret > 0) { |
| path->slots[level]++; |
| continue; |
| } else if (ret < 0) |
| return ret; |
| level = wc->level; |
| } |
| return 0; |
| } |
| |
| static noinline int walk_up_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct walk_control *wc, int max_level) |
| { |
| int level = wc->level; |
| int ret; |
| |
| path->slots[level] = btrfs_header_nritems(path->nodes[level]); |
| while (level < max_level && path->nodes[level]) { |
| wc->level = level; |
| if (path->slots[level] + 1 < |
| btrfs_header_nritems(path->nodes[level])) { |
| path->slots[level]++; |
| return 0; |
| } else { |
| ret = walk_up_proc(trans, root, path, wc); |
| if (ret > 0) |
| return 0; |
| |
| if (path->locks[level]) { |
| btrfs_tree_unlock_rw(path->nodes[level], |
| path->locks[level]); |
| path->locks[level] = 0; |
| } |
| free_extent_buffer(path->nodes[level]); |
| path->nodes[level] = NULL; |
| level++; |
| } |
| } |
| return 1; |
| } |
| |
| /* |
| * drop a subvolume tree. |
| * |
| * this function traverses the tree freeing any blocks that only |
| * referenced by the tree. |
| * |
| * when a shared tree block is found. this function decreases its |
| * reference count by one. if update_ref is true, this function |
| * also make sure backrefs for the shared block and all lower level |
| * blocks are properly updated. |
| * |
| * If called with for_reloc == 0, may exit early with -EAGAIN |
| */ |
| int btrfs_drop_snapshot(struct btrfs_root *root, |
| struct btrfs_block_rsv *block_rsv, int update_ref, |
| int for_reloc) |
| { |
| struct btrfs_path *path; |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *tree_root = root->fs_info->tree_root; |
| struct btrfs_root_item *root_item = &root->root_item; |
| struct walk_control *wc; |
| struct btrfs_key key; |
| int err = 0; |
| int ret; |
| int level; |
| bool root_dropped = false; |
| |
| btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid); |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| wc = kzalloc(sizeof(*wc), GFP_NOFS); |
| if (!wc) { |
| btrfs_free_path(path); |
| err = -ENOMEM; |
| goto out; |
| } |
| |
| trans = btrfs_start_transaction(tree_root, 0); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| goto out_free; |
| } |
| |
| if (block_rsv) |
| trans->block_rsv = block_rsv; |
| |
| if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
| level = btrfs_header_level(root->node); |
| path->nodes[level] = btrfs_lock_root_node(root); |
| btrfs_set_lock_blocking(path->nodes[level]); |
| path->slots[level] = 0; |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| memset(&wc->update_progress, 0, |
| sizeof(wc->update_progress)); |
| } else { |
| btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
| memcpy(&wc->update_progress, &key, |
| sizeof(wc->update_progress)); |
| |
| level = root_item->drop_level; |
| BUG_ON(level == 0); |
| path->lowest_level = level; |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| path->lowest_level = 0; |
| if (ret < 0) { |
| err = ret; |
| goto out_end_trans; |
| } |
| WARN_ON(ret > 0); |
| |
| /* |
| * unlock our path, this is safe because only this |
| * function is allowed to delete this snapshot |
| */ |
| btrfs_unlock_up_safe(path, 0); |
| |
| level = btrfs_header_level(root->node); |
| while (1) { |
| btrfs_tree_lock(path->nodes[level]); |
| btrfs_set_lock_blocking(path->nodes[level]); |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| |
| ret = btrfs_lookup_extent_info(trans, root, |
| path->nodes[level]->start, |
| level, 1, &wc->refs[level], |
| &wc->flags[level]); |
| if (ret < 0) { |
| err = ret; |
| goto out_end_trans; |
| } |
| BUG_ON(wc->refs[level] == 0); |
| |
| if (level == root_item->drop_level) |
| break; |
| |
| btrfs_tree_unlock(path->nodes[level]); |
| path->locks[level] = 0; |
| WARN_ON(wc->refs[level] != 1); |
| level--; |
| } |
| } |
| |
| wc->level = level; |
| wc->shared_level = -1; |
| wc->stage = DROP_REFERENCE; |
| wc->update_ref = update_ref; |
| wc->keep_locks = 0; |
| wc->for_reloc = for_reloc; |
| wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root); |
| |
| while (1) { |
| |
| ret = walk_down_tree(trans, root, path, wc); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| |
| ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL); |
| if (ret < 0) { |
| err = ret; |
| break; |
| } |
| |
| if (ret > 0) { |
| BUG_ON(wc->stage != DROP_REFERENCE); |
| break; |
| } |
| |
| if (wc->stage == DROP_REFERENCE) { |
| level = wc->level; |
| btrfs_node_key(path->nodes[level], |
| &root_item->drop_progress, |
| path->slots[level]); |
| root_item->drop_level = level; |
| } |
| |
| BUG_ON(wc->level == 0); |
| if (btrfs_should_end_transaction(trans, tree_root) || |
| (!for_reloc && btrfs_need_cleaner_sleep(root))) { |
| ret = btrfs_update_root(trans, tree_root, |
| &root->root_key, |
| root_item); |
| if (ret) { |
| btrfs_abort_transaction(trans, tree_root, ret); |
| err = ret; |
| goto out_end_trans; |
| } |
| |
| btrfs_end_transaction_throttle(trans, tree_root); |
| if (!for_reloc && btrfs_need_cleaner_sleep(root)) { |
| pr_debug("BTRFS: drop snapshot early exit\n"); |
| err = -EAGAIN; |
| goto out_free; |
| } |
| |
| trans = btrfs_start_transaction(tree_root, 0); |
| if (IS_ERR(trans)) { |
| err = PTR_ERR(trans); |
| goto out_free; |
| } |
| if (block_rsv) |
| trans->block_rsv = block_rsv; |
| } |
| } |
| btrfs_release_path(path); |
| if (err) |
| goto out_end_trans; |
| |
| ret = btrfs_del_root(trans, tree_root, &root->root_key); |
| if (ret) { |
| btrfs_abort_transaction(trans, tree_root, ret); |
| goto out_end_trans; |
| } |
| |
| if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { |
| ret = btrfs_find_root(tree_root, &root->root_key, path, |
| NULL, NULL); |
| if (ret < 0) { |
| btrfs_abort_transaction(trans, tree_root, ret); |
| err = ret; |
| goto out_end_trans; |
| } else if (ret > 0) { |
| /* if we fail to delete the orphan item this time |
| * around, it'll get picked up the next time. |
| * |
| * The most common failure here is just -ENOENT. |
| */ |
| btrfs_del_orphan_item(trans, tree_root, |
| root->root_key.objectid); |
| } |
| } |
| |
| if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) { |
| btrfs_add_dropped_root(trans, root); |
| } else { |
| free_extent_buffer(root->node); |
| free_extent_buffer(root->commit_root); |
| btrfs_put_fs_root(root); |
| } |
| root_dropped = true; |
| out_end_trans: |
| btrfs_end_transaction_throttle(trans, tree_root); |
| out_free: |
| kfree(wc); |
| btrfs_free_path(path); |
| out: |
| /* |
| * So if we need to stop dropping the snapshot for whatever reason we |
| * need to make sure to add it back to the dead root list so that we |
| * keep trying to do the work later. This also cleans up roots if we |
| * don't have it in the radix (like when we recover after a power fail |
| * or unmount) so we don't leak memory. |
| */ |
| if (!for_reloc && root_dropped == false) |
| btrfs_add_dead_root(root); |
| if (err && err != -EAGAIN) |
| btrfs_std_error(root->fs_info, err); |
| return err; |
| } |
| |
| /* |
| * drop subtree rooted at tree block 'node'. |
| * |
| * NOTE: this function will unlock and release tree block 'node' |
| * only used by relocation code |
| */ |
| int btrfs_drop_subtree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *node, |
| struct extent_buffer *parent) |
| { |
| struct btrfs_path *path; |
| struct walk_control *wc; |
| int level; |
| int parent_level; |
| int ret = 0; |
| int wret; |
| |
| BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| wc = kzalloc(sizeof(*wc), GFP_NOFS); |
| if (!wc) { |
| btrfs_free_path(path); |
| return -ENOMEM; |
| } |
| |
| btrfs_assert_tree_locked(parent); |
| parent_level = btrfs_header_level(parent); |
| extent_buffer_get(parent); |
| path->nodes[parent_level] = parent; |
| path->slots[parent_level] = btrfs_header_nritems(parent); |
| |
| btrfs_assert_tree_locked(node); |
| level = btrfs_header_level(node); |
| path->nodes[level] = node; |
| path->slots[level] = 0; |
| path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; |
| |
| wc->refs[parent_level] = 1; |
| wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF; |
| wc->level = level; |
| wc->shared_level = -1; |
| wc->stage = DROP_REFERENCE; |
| wc->update_ref = 0; |
| wc->keep_locks = 1; |
| wc->for_reloc = 1; |
| wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root); |
| |
| while (1) { |
| wret = walk_down_tree(trans, root, path, wc); |
| if (wret < 0) { |
| ret = wret; |
| break; |
| } |
| |
| wret = walk_up_tree(trans, root, path, wc, parent_level); |
| if (wret < 0) |
| ret = wret; |
| if (wret != 0) |
| break; |
| } |
| |
| kfree(wc); |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) |
| { |
| u64 num_devices; |
| u64 stripped; |
| |
| /* |
| * if restripe for this chunk_type is on pick target profile and |
| * return, otherwise do the usual balance |
| */ |
| stripped = get_restripe_target(root->fs_info, flags); |
| if (stripped) |
| return extended_to_chunk(stripped); |
| |
| num_devices = root->fs_info->fs_devices->rw_devices; |
| |
| stripped = BTRFS_BLOCK_GROUP_RAID0 | |
| BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 | |
| BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; |
| |
| if (num_devices == 1) { |
| stripped |= BTRFS_BLOCK_GROUP_DUP; |
| stripped = flags & ~stripped; |
| |
| /* turn raid0 into single device chunks */ |
| if (flags & BTRFS_BLOCK_GROUP_RAID0) |
| return stripped; |
| |
| /* turn mirroring into duplication */ |
| if (flags & (BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| return stripped | BTRFS_BLOCK_GROUP_DUP; |
| } else { |
| /* they already had raid on here, just return */ |
| if (flags & stripped) |
| return flags; |
| |
| stripped |= BTRFS_BLOCK_GROUP_DUP; |
| stripped = flags & ~stripped; |
| |
| /* switch duplicated blocks with raid1 */ |
| if (flags & BTRFS_BLOCK_GROUP_DUP) |
| return stripped | BTRFS_BLOCK_GROUP_RAID1; |
| |
| /* this is drive concat, leave it alone */ |
| } |
| |
| return flags; |
| } |
| |
| static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force) |
| { |
| struct btrfs_space_info *sinfo = cache->space_info; |
| u64 num_bytes; |
| u64 min_allocable_bytes; |
| int ret = -ENOSPC; |
| |
| /* |
| * We need some metadata space and system metadata space for |
| * allocating chunks in some corner cases until we force to set |
| * it to be readonly. |
| */ |
| if ((sinfo->flags & |
| (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) && |
| !force) |
| min_allocable_bytes = 1 * 1024 * 1024; |
| else |
| min_allocable_bytes = 0; |
| |
| spin_lock(&sinfo->lock); |
| spin_lock(&cache->lock); |
| |
| if (cache->ro) { |
| cache->ro++; |
| ret = 0; |
| goto out; |
| } |
| |
| num_bytes = cache->key.offset - cache->reserved - cache->pinned - |
| cache->bytes_super - btrfs_block_group_used(&cache->item); |
| |
| if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned + |
| sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes + |
| min_allocable_bytes <= sinfo->total_bytes) { |
| sinfo->bytes_readonly += num_bytes; |
| cache->ro++; |
| list_add_tail(&cache->ro_list, &sinfo->ro_bgs); |
| ret = 0; |
| } |
| out: |
| spin_unlock(&cache->lock); |
| spin_unlock(&sinfo->lock); |
| return ret; |
| } |
| |
| int btrfs_inc_block_group_ro(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache) |
| |
| { |
| struct btrfs_trans_handle *trans; |
| u64 alloc_flags; |
| int ret; |
| |
| again: |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) |
| return PTR_ERR(trans); |
| |
| /* |
| * we're not allowed to set block groups readonly after the dirty |
| * block groups cache has started writing. If it already started, |
| * back off and let this transaction commit |
| */ |
| mutex_lock(&root->fs_info->ro_block_group_mutex); |
| if (trans->transaction->dirty_bg_run) { |
| u64 transid = trans->transid; |
| |
| mutex_unlock(&root->fs_info->ro_block_group_mutex); |
| btrfs_end_transaction(trans, root); |
| |
| ret = btrfs_wait_for_commit(root, transid); |
| if (ret) |
| return ret; |
| goto again; |
| } |
| |
| /* |
| * if we are changing raid levels, try to allocate a corresponding |
| * block group with the new raid level. |
| */ |
| alloc_flags = update_block_group_flags(root, cache->flags); |
| if (alloc_flags != cache->flags) { |
| ret = do_chunk_alloc(trans, root, alloc_flags, |
| CHUNK_ALLOC_FORCE); |
| /* |
| * ENOSPC is allowed here, we may have enough space |
| * already allocated at the new raid level to |
| * carry on |
| */ |
| if (ret == -ENOSPC) |
| ret = 0; |
| if (ret < 0) |
| goto out; |
| } |
| |
| ret = inc_block_group_ro(cache, 0); |
| if (!ret) |
| goto out; |
| alloc_flags = get_alloc_profile(root, cache->space_info->flags); |
| ret = do_chunk_alloc(trans, root, alloc_flags, |
| CHUNK_ALLOC_FORCE); |
| if (ret < 0) |
| goto out; |
| ret = inc_block_group_ro(cache, 0); |
| out: |
| if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { |
| alloc_flags = update_block_group_flags(root, cache->flags); |
| lock_chunks(root->fs_info->chunk_root); |
| check_system_chunk(trans, root, alloc_flags); |
| unlock_chunks(root->fs_info->chunk_root); |
| } |
| mutex_unlock(&root->fs_info->ro_block_group_mutex); |
| |
| btrfs_end_transaction(trans, root); |
| return ret; |
| } |
| |
| int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 type) |
| { |
| u64 alloc_flags = get_alloc_profile(root, type); |
| return do_chunk_alloc(trans, root, alloc_flags, |
| CHUNK_ALLOC_FORCE); |
| } |
| |
| /* |
| * helper to account the unused space of all the readonly block group in the |
| * space_info. takes mirrors into account. |
| */ |
| u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo) |
| { |
| struct btrfs_block_group_cache *block_group; |
| u64 free_bytes = 0; |
| int factor; |
| |
| /* It's df, we don't care if it's racey */ |
| if (list_empty(&sinfo->ro_bgs)) |
| return 0; |
| |
| spin_lock(&sinfo->lock); |
| list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) { |
| spin_lock(&block_group->lock); |
| |
| if (!block_group->ro) { |
| spin_unlock(&block_group->lock); |
| continue; |
| } |
| |
| if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10 | |
| BTRFS_BLOCK_GROUP_DUP)) |
| factor = 2; |
| else |
| factor = 1; |
| |
| free_bytes += (block_group->key.offset - |
| btrfs_block_group_used(&block_group->item)) * |
| factor; |
| |
| spin_unlock(&block_group->lock); |
| } |
| spin_unlock(&sinfo->lock); |
| |
| return free_bytes; |
| } |
| |
| void btrfs_dec_block_group_ro(struct btrfs_root *root, |
| struct btrfs_block_group_cache *cache) |
| { |
| struct btrfs_space_info *sinfo = cache->space_info; |
| u64 num_bytes; |
| |
| BUG_ON(!cache->ro); |
| |
| spin_lock(&sinfo->lock); |
| spin_lock(&cache->lock); |
| if (!--cache->ro) { |
| num_bytes = cache->key.offset - cache->reserved - |
| cache->pinned - cache->bytes_super - |
| btrfs_block_group_used(&cache->item); |
| sinfo->bytes_readonly -= num_bytes; |
| list_del_init(&cache->ro_list); |
| } |
| spin_unlock(&cache->lock); |
| spin_unlock(&sinfo->lock); |
| } |
| |
| /* |
| * checks to see if its even possible to relocate this block group. |
| * |
| * @return - -1 if it's not a good idea to relocate this block group, 0 if its |
| * ok to go ahead and try. |
| */ |
| int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_space_info *space_info; |
| struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; |
| struct btrfs_device *device; |
| struct btrfs_trans_handle *trans; |
| u64 min_free; |
| u64 dev_min = 1; |
| u64 dev_nr = 0; |
| u64 target; |
| int index; |
| int full = 0; |
| int ret = 0; |
| |
| block_group = btrfs_lookup_block_group(root->fs_info, bytenr); |
| |
| /* odd, couldn't find the block group, leave it alone */ |
| if (!block_group) |
| return -1; |
| |
| min_free = btrfs_block_group_used(&block_group->item); |
| |
| /* no bytes used, we're good */ |
| if (!min_free) |
| goto out; |
| |
| space_info = block_group->space_info; |
| spin_lock(&space_info->lock); |
| |
| full = space_info->full; |
| |
| /* |
| * if this is the last block group we have in this space, we can't |
| * relocate it unless we're able to allocate a new chunk below. |
| * |
| * Otherwise, we need to make sure we have room in the space to handle |
| * all of the extents from this block group. If we can, we're good |
| */ |
| if ((space_info->total_bytes != block_group->key.offset) && |
| (space_info->bytes_used + space_info->bytes_reserved + |
| space_info->bytes_pinned + space_info->bytes_readonly + |
| min_free < space_info->total_bytes)) { |
| spin_unlock(&space_info->lock); |
| goto out; |
| } |
| spin_unlock(&space_info->lock); |
| |
| /* |
| * ok we don't have enough space, but maybe we have free space on our |
| * devices to allocate new chunks for relocation, so loop through our |
| * alloc devices and guess if we have enough space. if this block |
| * group is going to be restriped, run checks against the target |
| * profile instead of the current one. |
| */ |
| ret = -1; |
| |
| /* |
| * index: |
| * 0: raid10 |
| * 1: raid1 |
| * 2: dup |
| * 3: raid0 |
| * 4: single |
| */ |
| target = get_restripe_target(root->fs_info, block_group->flags); |
| if (target) { |
| index = __get_raid_index(extended_to_chunk(target)); |
| } else { |
| /* |
| * this is just a balance, so if we were marked as full |
| * we know there is no space for a new chunk |
| */ |
| if (full) |
| goto out; |
| |
| index = get_block_group_index(block_group); |
| } |
| |
| if (index == BTRFS_RAID_RAID10) { |
| dev_min = 4; |
| /* Divide by 2 */ |
| min_free >>= 1; |
| } else if (index == BTRFS_RAID_RAID1) { |
| dev_min = 2; |
| } else if (index == BTRFS_RAID_DUP) { |
| /* Multiply by 2 */ |
| min_free <<= 1; |
| } else if (index == BTRFS_RAID_RAID0) { |
| dev_min = fs_devices->rw_devices; |
| min_free = div64_u64(min_free, dev_min); |
| } |
| |
| /* We need to do this so that we can look at pending chunks */ |
| trans = btrfs_join_transaction(root); |
| if (IS_ERR(trans)) { |
| ret = PTR_ERR(trans); |
| goto out; |
| } |
| |
| mutex_lock(&root->fs_info->chunk_mutex); |
| list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { |
| u64 dev_offset; |
| |
| /* |
| * check to make sure we can actually find a chunk with enough |
| * space to fit our block group in. |
| */ |
| if (device->total_bytes > device->bytes_used + min_free && |
| !device->is_tgtdev_for_dev_replace) { |
| ret = find_free_dev_extent(trans, device, min_free, |
| &dev_offset, NULL); |
| if (!ret) |
| dev_nr++; |
| |
| if (dev_nr >= dev_min) |
| break; |
| |
| ret = -1; |
| } |
| } |
| mutex_unlock(&root->fs_info->chunk_mutex); |
| btrfs_end_transaction(trans, root); |
| out: |
| btrfs_put_block_group(block_group); |
| return ret; |
| } |
| |
| static int find_first_block_group(struct btrfs_root *root, |
| struct btrfs_path *path, struct btrfs_key *key) |
| { |
| int ret = 0; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| int slot; |
| |
| ret = btrfs_search_slot(NULL, root, key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| while (1) { |
| slot = path->slots[0]; |
| leaf = path->nodes[0]; |
| if (slot >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret == 0) |
| continue; |
| if (ret < 0) |
| goto out; |
| break; |
| } |
| btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| |
| if (found_key.objectid >= key->objectid && |
| found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| ret = 0; |
| goto out; |
| } |
| path->slots[0]++; |
| } |
| out: |
| return ret; |
| } |
| |
| void btrfs_put_block_group_cache(struct btrfs_fs_info *info) |
| { |
| struct btrfs_block_group_cache *block_group; |
| u64 last = 0; |
| |
| while (1) { |
| struct inode *inode; |
| |
| block_group = btrfs_lookup_first_block_group(info, last); |
| while (block_group) { |
| spin_lock(&block_group->lock); |
| if (block_group->iref) |
| break; |
| spin_unlock(&block_group->lock); |
| block_group = next_block_group(info->tree_root, |
| block_group); |
| } |
| if (!block_group) { |
| if (last == 0) |
| break; |
| last = 0; |
| continue; |
| } |
| |
| inode = block_group->inode; |
| block_group->iref = 0; |
| block_group->inode = NULL; |
| spin_unlock(&block_group->lock); |
| iput(inode); |
| last = block_group->key.objectid + block_group->key.offset; |
| btrfs_put_block_group(block_group); |
| } |
| } |
| |
| int btrfs_free_block_groups(struct btrfs_fs_info *info) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_space_info *space_info; |
| struct btrfs_caching_control *caching_ctl; |
| struct rb_node *n; |
| |
| down_write(&info->commit_root_sem); |
| while (!list_empty(&info->caching_block_groups)) { |
| caching_ctl = list_entry(info->caching_block_groups.next, |
| struct btrfs_caching_control, list); |
| list_del(&caching_ctl->list); |
| put_caching_control(caching_ctl); |
| } |
| up_write(&info->commit_root_sem); |
| |
| spin_lock(&info->unused_bgs_lock); |
| while (!list_empty(&info->unused_bgs)) { |
| block_group = list_first_entry(&info->unused_bgs, |
| struct btrfs_block_group_cache, |
| bg_list); |
| list_del_init(&block_group->bg_list); |
| btrfs_put_block_group(block_group); |
| } |
| spin_unlock(&info->unused_bgs_lock); |
| |
| spin_lock(&info->block_group_cache_lock); |
| while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { |
| block_group = rb_entry(n, struct btrfs_block_group_cache, |
| cache_node); |
| rb_erase(&block_group->cache_node, |
| &info->block_group_cache_tree); |
| RB_CLEAR_NODE(&block_group->cache_node); |
| spin_unlock(&info->block_group_cache_lock); |
| |
| down_write(&block_group->space_info->groups_sem); |
| list_del(&block_group->list); |
| up_write(&block_group->space_info->groups_sem); |
| |
| if (block_group->cached == BTRFS_CACHE_STARTED) |
| wait_block_group_cache_done(block_group); |
| |
| /* |
| * We haven't cached this block group, which means we could |
| * possibly have excluded extents on this block group. |
| */ |
| if (block_group->cached == BTRFS_CACHE_NO || |
| block_group->cached == BTRFS_CACHE_ERROR) |
| free_excluded_extents(info->extent_root, block_group); |
| |
| btrfs_remove_free_space_cache(block_group); |
| btrfs_put_block_group(block_group); |
| |
| spin_lock(&info->block_group_cache_lock); |
| } |
| spin_unlock(&info->block_group_cache_lock); |
| |
| /* now that all the block groups are freed, go through and |
| * free all the space_info structs. This is only called during |
| * the final stages of unmount, and so we know nobody is |
| * using them. We call synchronize_rcu() once before we start, |
| * just to be on the safe side. |
| */ |
| synchronize_rcu(); |
| |
| release_global_block_rsv(info); |
| |
| while (!list_empty(&info->space_info)) { |
| int i; |
| |
| space_info = list_entry(info->space_info.next, |
| struct btrfs_space_info, |
| list); |
| if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) { |
| if (WARN_ON(space_info->bytes_pinned > 0 || |
| space_info->bytes_reserved > 0 || |
| space_info->bytes_may_use > 0)) { |
| dump_space_info(space_info, 0, 0); |
| } |
| } |
| list_del(&space_info->list); |
| for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { |
| struct kobject *kobj; |
| kobj = space_info->block_group_kobjs[i]; |
| space_info->block_group_kobjs[i] = NULL; |
| if (kobj) { |
| kobject_del(kobj); |
| kobject_put(kobj); |
| } |
| } |
| kobject_del(&space_info->kobj); |
| kobject_put(&space_info->kobj); |
| } |
| return 0; |
| } |
| |
| static void __link_block_group(struct btrfs_space_info *space_info, |
| struct btrfs_block_group_cache *cache) |
| { |
| int index = get_block_group_index(cache); |
| bool first = false; |
| |
| down_write(&space_info->groups_sem); |
| if (list_empty(&space_info->block_groups[index])) |
| first = true; |
| list_add_tail(&cache->list, &space_info->block_groups[index]); |
| up_write(&space_info->groups_sem); |
| |
| if (first) { |
| struct raid_kobject *rkobj; |
| int ret; |
| |
| rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS); |
| if (!rkobj) |
| goto out_err; |
| rkobj->raid_type = index; |
| kobject_init(&rkobj->kobj, &btrfs_raid_ktype); |
| ret = kobject_add(&rkobj->kobj, &space_info->kobj, |
| "%s", get_raid_name(index)); |
| if (ret) { |
| kobject_put(&rkobj->kobj); |
| goto out_err; |
| } |
| space_info->block_group_kobjs[index] = &rkobj->kobj; |
| } |
| |
| return; |
| out_err: |
| pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n"); |
| } |
| |
| static struct btrfs_block_group_cache * |
| btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size) |
| { |
| struct btrfs_block_group_cache *cache; |
| |
| cache = kzalloc(sizeof(*cache), GFP_NOFS); |
| if (!cache) |
| return NULL; |
| |
| cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl), |
| GFP_NOFS); |
| if (!cache->free_space_ctl) { |
| kfree(cache); |
| return NULL; |
| } |
| |
| cache->key.objectid = start; |
| cache->key.offset = size; |
| cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| |
| cache->sectorsize = root->sectorsize; |
| cache->fs_info = root->fs_info; |
| cache->full_stripe_len = btrfs_full_stripe_len(root, |
| &root->fs_info->mapping_tree, |
| start); |
| atomic_set(&cache->count, 1); |
| spin_lock_init(&cache->lock); |
| init_rwsem(&cache->data_rwsem); |
| INIT_LIST_HEAD(&cache->list); |
| INIT_LIST_HEAD(&cache->cluster_list); |
| INIT_LIST_HEAD(&cache->bg_list); |
| INIT_LIST_HEAD(&cache->ro_list); |
| INIT_LIST_HEAD(&cache->dirty_list); |
| INIT_LIST_HEAD(&cache->io_list); |
| btrfs_init_free_space_ctl(cache); |
| atomic_set(&cache->trimming, 0); |
| |
| return cache; |
| } |
| |
| int btrfs_read_block_groups(struct btrfs_root *root) |
| { |
| struct btrfs_path *path; |
| int ret; |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_space_info *space_info; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| int need_clear = 0; |
| u64 cache_gen; |
| |
| root = info->extent_root; |
| key.objectid = 0; |
| key.offset = 0; |
| key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| path->reada = 1; |
| |
| cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); |
| if (btrfs_test_opt(root, SPACE_CACHE) && |
| btrfs_super_generation(root->fs_info->super_copy) != cache_gen) |
| need_clear = 1; |
| if (btrfs_test_opt(root, CLEAR_CACHE)) |
| need_clear = 1; |
| |
| while (1) { |
| ret = find_first_block_group(root, path, &key); |
| if (ret > 0) |
| break; |
| if (ret != 0) |
| goto error; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| |
| cache = btrfs_create_block_group_cache(root, found_key.objectid, |
| found_key.offset); |
| if (!cache) { |
| ret = -ENOMEM; |
| goto error; |
| } |
| |
| if (need_clear) { |
| /* |
| * When we mount with old space cache, we need to |
| * set BTRFS_DC_CLEAR and set dirty flag. |
| * |
| * a) Setting 'BTRFS_DC_CLEAR' makes sure that we |
| * truncate the old free space cache inode and |
| * setup a new one. |
| * b) Setting 'dirty flag' makes sure that we flush |
| * the new space cache info onto disk. |
| */ |
| if (btrfs_test_opt(root, SPACE_CACHE)) |
| cache->disk_cache_state = BTRFS_DC_CLEAR; |
| } |
| |
| read_extent_buffer(leaf, &cache->item, |
| btrfs_item_ptr_offset(leaf, path->slots[0]), |
| sizeof(cache->item)); |
| cache->flags = btrfs_block_group_flags(&cache->item); |
| |
| key.objectid = found_key.objectid + found_key.offset; |
| btrfs_release_path(path); |
| |
| /* |
| * We need to exclude the super stripes now so that the space |
| * info has super bytes accounted for, otherwise we'll think |
| * we have more space than we actually do. |
| */ |
| ret = exclude_super_stripes(root, cache); |
| if (ret) { |
| /* |
| * We may have excluded something, so call this just in |
| * case. |
| */ |
| free_excluded_extents(root, cache); |
| btrfs_put_block_group(cache); |
| goto error; |
| } |
| |
| /* |
| * check for two cases, either we are full, and therefore |
| * don't need to bother with the caching work since we won't |
| * find any space, or we are empty, and we can just add all |
| * the space in and be done with it. This saves us _alot_ of |
| * time, particularly in the full case. |
| */ |
| if (found_key.offset == btrfs_block_group_used(&cache->item)) { |
| cache->last_byte_to_unpin = (u64)-1; |
| cache->cached = BTRFS_CACHE_FINISHED; |
| free_excluded_extents(root, cache); |
| } else if (btrfs_block_group_used(&cache->item) == 0) { |
| cache->last_byte_to_unpin = (u64)-1; |
| cache->cached = BTRFS_CACHE_FINISHED; |
| add_new_free_space(cache, root->fs_info, |
| found_key.objectid, |
| found_key.objectid + |
| found_key.offset); |
| free_excluded_extents(root, cache); |
| } |
| |
| ret = btrfs_add_block_group_cache(root->fs_info, cache); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| btrfs_put_block_group(cache); |
| goto error; |
| } |
| |
| ret = update_space_info(info, cache->flags, found_key.offset, |
| btrfs_block_group_used(&cache->item), |
| &space_info); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| spin_lock(&info->block_group_cache_lock); |
| rb_erase(&cache->cache_node, |
| &info->block_group_cache_tree); |
| RB_CLEAR_NODE(&cache->cache_node); |
| spin_unlock(&info->block_group_cache_lock); |
| btrfs_put_block_group(cache); |
| goto error; |
| } |
| |
| cache->space_info = space_info; |
| spin_lock(&cache->space_info->lock); |
| cache->space_info->bytes_readonly += cache->bytes_super; |
| spin_unlock(&cache->space_info->lock); |
| |
| __link_block_group(space_info, cache); |
| |
| set_avail_alloc_bits(root->fs_info, cache->flags); |
| if (btrfs_chunk_readonly(root, cache->key.objectid)) { |
| inc_block_group_ro(cache, 1); |
| } else if (btrfs_block_group_used(&cache->item) == 0) { |
| spin_lock(&info->unused_bgs_lock); |
| /* Should always be true but just in case. */ |
| if (list_empty(&cache->bg_list)) { |
| btrfs_get_block_group(cache); |
| list_add_tail(&cache->bg_list, |
| &info->unused_bgs); |
| } |
| spin_unlock(&info->unused_bgs_lock); |
| } |
| } |
| |
| list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) { |
| if (!(get_alloc_profile(root, space_info->flags) & |
| (BTRFS_BLOCK_GROUP_RAID10 | |
| BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID5 | |
| BTRFS_BLOCK_GROUP_RAID6 | |
| BTRFS_BLOCK_GROUP_DUP))) |
| continue; |
| /* |
| * avoid allocating from un-mirrored block group if there are |
| * mirrored block groups. |
| */ |
| list_for_each_entry(cache, |
| &space_info->block_groups[BTRFS_RAID_RAID0], |
| list) |
| inc_block_group_ro(cache, 1); |
| list_for_each_entry(cache, |
| &space_info->block_groups[BTRFS_RAID_SINGLE], |
| list) |
| inc_block_group_ro(cache, 1); |
| } |
| |
| init_global_block_rsv(info); |
| ret = 0; |
| error: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct btrfs_block_group_cache *block_group, *tmp; |
| struct btrfs_root *extent_root = root->fs_info->extent_root; |
| struct btrfs_block_group_item item; |
| struct btrfs_key key; |
| int ret = 0; |
| bool can_flush_pending_bgs = trans->can_flush_pending_bgs; |
| |
| trans->can_flush_pending_bgs = false; |
| list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) { |
| if (ret) |
| goto next; |
| |
| spin_lock(&block_group->lock); |
| memcpy(&item, &block_group->item, sizeof(item)); |
| memcpy(&key, &block_group->key, sizeof(key)); |
| spin_unlock(&block_group->lock); |
| |
| ret = btrfs_insert_item(trans, extent_root, &key, &item, |
| sizeof(item)); |
| if (ret) |
| btrfs_abort_transaction(trans, extent_root, ret); |
| ret = btrfs_finish_chunk_alloc(trans, extent_root, |
| key.objectid, key.offset); |
| if (ret) |
| btrfs_abort_transaction(trans, extent_root, ret); |
| next: |
| list_del_init(&block_group->bg_list); |
| } |
| trans->can_flush_pending_bgs = can_flush_pending_bgs; |
| } |
| |
| int btrfs_make_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytes_used, |
| u64 type, u64 chunk_objectid, u64 chunk_offset, |
| u64 size) |
| { |
| int ret; |
| struct btrfs_root *extent_root; |
| struct btrfs_block_group_cache *cache; |
| |
| extent_root = root->fs_info->extent_root; |
| |
| btrfs_set_log_full_commit(root->fs_info, trans); |
| |
| cache = btrfs_create_block_group_cache(root, chunk_offset, size); |
| if (!cache) |
| return -ENOMEM; |
| |
| btrfs_set_block_group_used(&cache->item, bytes_used); |
| btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); |
| btrfs_set_block_group_flags(&cache->item, type); |
| |
| cache->flags = type; |
| cache->last_byte_to_unpin = (u64)-1; |
| cache->cached = BTRFS_CACHE_FINISHED; |
| ret = exclude_super_stripes(root, cache); |
| if (ret) { |
| /* |
| * We may have excluded something, so call this just in |
| * case. |
| */ |
| free_excluded_extents(root, cache); |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| |
| add_new_free_space(cache, root->fs_info, chunk_offset, |
| chunk_offset + size); |
| |
| free_excluded_extents(root, cache); |
| |
| /* |
| * Call to ensure the corresponding space_info object is created and |
| * assigned to our block group, but don't update its counters just yet. |
| * We want our bg to be added to the rbtree with its ->space_info set. |
| */ |
| ret = update_space_info(root->fs_info, cache->flags, 0, 0, |
| &cache->space_info); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| |
| ret = btrfs_add_block_group_cache(root->fs_info, cache); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| |
| /* |
| * Now that our block group has its ->space_info set and is inserted in |
| * the rbtree, update the space info's counters. |
| */ |
| ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, |
| &cache->space_info); |
| if (ret) { |
| btrfs_remove_free_space_cache(cache); |
| spin_lock(&root->fs_info->block_group_cache_lock); |
| rb_erase(&cache->cache_node, |
| &root->fs_info->block_group_cache_tree); |
| RB_CLEAR_NODE(&cache->cache_node); |
| spin_unlock(&root->fs_info->block_group_cache_lock); |
| btrfs_put_block_group(cache); |
| return ret; |
| } |
| update_global_block_rsv(root->fs_info); |
| |
| spin_lock(&cache->space_info->lock); |
| cache->space_info->bytes_readonly += cache->bytes_super; |
| spin_unlock(&cache->space_info->lock); |
| |
| __link_block_group(cache->space_info, cache); |
| |
| list_add_tail(&cache->bg_list, &trans->new_bgs); |
| |
| set_avail_alloc_bits(extent_root->fs_info, type); |
| |
| return 0; |
| } |
| |
| static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) |
| { |
| u64 extra_flags = chunk_to_extended(flags) & |
| BTRFS_EXTENDED_PROFILE_MASK; |
| |
| write_seqlock(&fs_info->profiles_lock); |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| fs_info->avail_data_alloc_bits &= ~extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| fs_info->avail_metadata_alloc_bits &= ~extra_flags; |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| fs_info->avail_system_alloc_bits &= ~extra_flags; |
| write_sequnlock(&fs_info->profiles_lock); |
| } |
| |
| int btrfs_remove_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 group_start, |
| struct extent_map *em) |
| { |
| struct btrfs_path *path; |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_free_cluster *cluster; |
| struct btrfs_root *tree_root = root->fs_info->tree_root; |
| struct btrfs_key key; |
| struct inode *inode; |
| struct kobject *kobj = NULL; |
| int ret; |
| int index; |
| int factor; |
| struct btrfs_caching_control *caching_ctl = NULL; |
| bool remove_em; |
| |
| root = root->fs_info->extent_root; |
| |
| block_group = btrfs_lookup_block_group(root->fs_info, group_start); |
| BUG_ON(!block_group); |
| BUG_ON(!block_group->ro); |
| |
| /* |
| * Free the reserved super bytes from this block group before |
| * remove it. |
| */ |
| free_excluded_extents(root, block_group); |
| |
| memcpy(&key, &block_group->key, sizeof(key)); |
| index = get_block_group_index(block_group); |
| if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP | |
| BTRFS_BLOCK_GROUP_RAID1 | |
| BTRFS_BLOCK_GROUP_RAID10)) |
| factor = 2; |
| else |
| factor = 1; |
| |
| /* make sure this block group isn't part of an allocation cluster */ |
| cluster = &root->fs_info->data_alloc_cluster; |
| spin_lock(&cluster->refill_lock); |
| btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&cluster->refill_lock); |
| |
| /* |
| * make sure this block group isn't part of a metadata |
| * allocation cluster |
| */ |
| cluster = &root->fs_info->meta_alloc_cluster; |
| spin_lock(&cluster->refill_lock); |
| btrfs_return_cluster_to_free_space(block_group, cluster); |
| spin_unlock(&cluster->refill_lock); |
| |
| path = btrfs_alloc_path(); |
| if (!path) { |
| ret = -ENOMEM; |
| goto out; |
| } |
| |
| /* |
| * get the inode first so any iput calls done for the io_list |
| * aren't the final iput (no unlinks allowed now) |
| */ |
| inode = lookup_free_space_inode(tree_root, block_group, path); |
| |
| mutex_lock(&trans->transaction->cache_write_mutex); |
| /* |
| * make sure our free spache cache IO is done before remove the |
| * free space inode |
| */ |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| if (!list_empty(&block_group->io_list)) { |
| list_del_init(&block_group->io_list); |
| |
| WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode); |
| |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| btrfs_wait_cache_io(root, trans, block_group, |
| &block_group->io_ctl, path, |
| block_group->key.objectid); |
| btrfs_put_block_group(block_group); |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| } |
| |
| if (!list_empty(&block_group->dirty_list)) { |
| list_del_init(&block_group->dirty_list); |
| btrfs_put_block_group(block_group); |
| } |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| mutex_unlock(&trans->transaction->cache_write_mutex); |
| |
| if (!IS_ERR(inode)) { |
| ret = btrfs_orphan_add(trans, inode); |
| if (ret) { |
| btrfs_add_delayed_iput(inode); |
| goto out; |
| } |
| clear_nlink(inode); |
| /* One for the block groups ref */ |
| spin_lock(&block_group->lock); |
| if (block_group->iref) { |
| block_group->iref = 0; |
| block_group->inode = NULL; |
| spin_unlock(&block_group->lock); |
| iput(inode); |
| } else { |
| spin_unlock(&block_group->lock); |
| } |
| /* One for our lookup ref */ |
| btrfs_add_delayed_iput(inode); |
| } |
| |
| key.objectid = BTRFS_FREE_SPACE_OBJECTID; |
| key.offset = block_group->key.objectid; |
| key.type = 0; |
| |
| ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); |
| if (ret < 0) |
| goto out; |
| if (ret > 0) |
| btrfs_release_path(path); |
| if (ret == 0) { |
| ret = btrfs_del_item(trans, tree_root, path); |
| if (ret) |
| goto out; |
| btrfs_release_path(path); |
| } |
| |
| spin_lock(&root->fs_info->block_group_cache_lock); |
| rb_erase(&block_group->cache_node, |
| &root->fs_info->block_group_cache_tree); |
| RB_CLEAR_NODE(&block_group->cache_node); |
| |
| if (root->fs_info->first_logical_byte == block_group->key.objectid) |
| root->fs_info->first_logical_byte = (u64)-1; |
| spin_unlock(&root->fs_info->block_group_cache_lock); |
| |
| down_write(&block_group->space_info->groups_sem); |
| /* |
| * we must use list_del_init so people can check to see if they |
| * are still on the list after taking the semaphore |
| */ |
| list_del_init(&block_group->list); |
| if (list_empty(&block_group->space_info->block_groups[index])) { |
| kobj = block_group->space_info->block_group_kobjs[index]; |
| block_group->space_info->block_group_kobjs[index] = NULL; |
| clear_avail_alloc_bits(root->fs_info, block_group->flags); |
| } |
| up_write(&block_group->space_info->groups_sem); |
| if (kobj) { |
| kobject_del(kobj); |
| kobject_put(kobj); |
| } |
| |
| if (block_group->has_caching_ctl) |
| caching_ctl = get_caching_control(block_group); |
| if (block_group->cached == BTRFS_CACHE_STARTED) |
| wait_block_group_cache_done(block_group); |
| if (block_group->has_caching_ctl) { |
| down_write(&root->fs_info->commit_root_sem); |
| if (!caching_ctl) { |
| struct btrfs_caching_control *ctl; |
| |
| list_for_each_entry(ctl, |
| &root->fs_info->caching_block_groups, list) |
| if (ctl->block_group == block_group) { |
| caching_ctl = ctl; |
| atomic_inc(&caching_ctl->count); |
| break; |
| } |
| } |
| if (caching_ctl) |
| list_del_init(&caching_ctl->list); |
| up_write(&root->fs_info->commit_root_sem); |
| if (caching_ctl) { |
| /* Once for the caching bgs list and once for us. */ |
| put_caching_control(caching_ctl); |
| put_caching_control(caching_ctl); |
| } |
| } |
| |
| spin_lock(&trans->transaction->dirty_bgs_lock); |
| if (!list_empty(&block_group->dirty_list)) { |
| WARN_ON(1); |
| } |
| if (!list_empty(&block_group->io_list)) { |
| WARN_ON(1); |
| } |
| spin_unlock(&trans->transaction->dirty_bgs_lock); |
| btrfs_remove_free_space_cache(block_group); |
| |
| spin_lock(&block_group->space_info->lock); |
| list_del_init(&block_group->ro_list); |
| |
| if (btrfs_test_opt(root, ENOSPC_DEBUG)) { |
| WARN_ON(block_group->space_info->total_bytes |
| < block_group->key.offset); |
| WARN_ON(block_group->space_info->bytes_readonly |
| < block_group->key.offset); |
| WARN_ON(block_group->space_info->disk_total |
| < block_group->key.offset * factor); |
| } |
| block_group->space_info->total_bytes -= block_group->key.offset; |
| block_group->space_info->bytes_readonly -= block_group->key.offset; |
| block_group->space_info->disk_total -= block_group->key.offset * factor; |
| |
| spin_unlock(&block_group->space_info->lock); |
| |
| memcpy(&key, &block_group->key, sizeof(key)); |
| |
| lock_chunks(root); |
| if (!list_empty(&em->list)) { |
| /* We're in the transaction->pending_chunks list. */ |
| free_extent_map(em); |
| } |
| spin_lock(&block_group->lock); |
| block_group->removed = 1; |
| /* |
| * At this point trimming can't start on this block group, because we |
| * removed the block group from the tree fs_info->block_group_cache_tree |
| * so no one can't find it anymore and even if someone already got this |
| * block group before we removed it from the rbtree, they have already |
| * incremented block_group->trimming - if they didn't, they won't find |
| * any free space entries because we already removed them all when we |
| * called btrfs_remove_free_space_cache(). |
| * |
| * And we must not remove the extent map from the fs_info->mapping_tree |
| * to prevent the same logical address range and physical device space |
| * ranges from being reused for a new block group. This is because our |
| * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is |
| * completely transactionless, so while it is trimming a range the |
| * currently running transaction might finish and a new one start, |
| * allowing for new block groups to be created that can reuse the same |
| * physical device locations unless we take this special care. |
| * |
| * There may also be an implicit trim operation if the file system |
| * is mounted with -odiscard. The same protections must remain |
| * in place until the extents have been discarded completely when |
| * the transaction commit has completed. |
| */ |
| remove_em = (atomic_read(&block_group->trimming) == 0); |
| /* |
| * Make sure a trimmer task always sees the em in the pinned_chunks list |
| * if it sees block_group->removed == 1 (needs to lock block_group->lock |
| * before checking block_group->removed). |
| */ |
| if (!remove_em) { |
| /* |
| * Our em might be in trans->transaction->pending_chunks which |
| * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks), |
| * and so is the fs_info->pinned_chunks list. |
| * |
| * So at this point we must be holding the chunk_mutex to avoid |
| * any races with chunk allocation (more specifically at |
| * volumes.c:contains_pending_extent()), to ensure it always |
| * sees the em, either in the pending_chunks list or in the |
| * pinned_chunks list. |
| */ |
| list_move_tail(&em->list, &root->fs_info->pinned_chunks); |
| } |
| spin_unlock(&block_group->lock); |
| |
| if (remove_em) { |
| struct extent_map_tree *em_tree; |
| |
| em_tree = &root->fs_info->mapping_tree.map_tree; |
| write_lock(&em_tree->lock); |
| /* |
| * The em might be in the pending_chunks list, so make sure the |
| * chunk mutex is locked, since remove_extent_mapping() will |
| * delete us from that list. |
| */ |
| remove_extent_mapping(em_tree, em); |
| write_unlock(&em_tree->lock); |
| /* once for the tree */ |
| free_extent_map(em); |
| } |
| |
| unlock_chunks(root); |
| |
| btrfs_put_block_group(block_group); |
| btrfs_put_block_group(block_group); |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret > 0) |
| ret = -EIO; |
| if (ret < 0) |
| goto out; |
| |
| ret = btrfs_del_item(trans, root, path); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * Process the unused_bgs list and remove any that don't have any allocated |
| * space inside of them. |
| */ |
| void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_block_group_cache *block_group; |
| struct btrfs_space_info *space_info; |
| struct btrfs_root *root = fs_info->extent_root; |
| struct btrfs_trans_handle *trans; |
| int ret = 0; |
| |
| if (!fs_info->open) |
| return; |
| |
| spin_lock(&fs_info->unused_bgs_lock); |
| while (!list_empty(&fs_info->unused_bgs)) { |
| u64 start, end; |
| int trimming; |
| |
| block_group = list_first_entry(&fs_info->unused_bgs, |
| struct btrfs_block_group_cache, |
| bg_list); |
| space_info = block_group->space_info; |
| list_del_init(&block_group->bg_list); |
| if (ret || btrfs_mixed_space_info(space_info)) { |
| btrfs_put_block_group(block_group); |
| continue; |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| |
| mutex_lock(&root->fs_info->delete_unused_bgs_mutex); |
| |
| /* Don't want to race with allocators so take the groups_sem */ |
| down_write(&space_info->groups_sem); |
| spin_lock(&block_group->lock); |
| if (block_group->reserved || |
| btrfs_block_group_used(&block_group->item) || |
| block_group->ro) { |
| /* |
| * We want to bail if we made new allocations or have |
| * outstanding allocations in this block group. We do |
| * the ro check in case balance is currently acting on |
| * this block group. |
| */ |
| spin_unlock(&block_group->lock); |
| up_write(&space_info->groups_sem); |
| goto next; |
| } |
| spin_unlock(&block_group->lock); |
| |
| /* We don't want to force the issue, only flip if it's ok. */ |
| ret = inc_block_group_ro(block_group, 0); |
| up_write(&space_info->groups_sem); |
| if (ret < 0) { |
| ret = 0; |
| goto next; |
| } |
| |
| /* |
| * Want to do this before we do anything else so we can recover |
| * properly if we fail to join the transaction. |
| */ |
| /* 1 for btrfs_orphan_reserve_metadata() */ |
| trans = btrfs_start_transaction(root, 1); |
| if (IS_ERR(trans)) { |
| btrfs_dec_block_group_ro(root, block_group); |
| ret = PTR_ERR(trans); |
| goto next; |
| } |
| |
| /* |
| * We could have pending pinned extents for this block group, |
| * just delete them, we don't care about them anymore. |
| */ |
| start = block_group->key.objectid; |
| end = start + block_group->key.offset - 1; |
| /* |
| * Hold the unused_bg_unpin_mutex lock to avoid racing with |
| * btrfs_finish_extent_commit(). If we are at transaction N, |
| * another task might be running finish_extent_commit() for the |
| * previous transaction N - 1, and have seen a range belonging |
| * to the block group in freed_extents[] before we were able to |
| * clear the whole block group range from freed_extents[]. This |
| * means that task can lookup for the block group after we |
| * unpinned it from freed_extents[] and removed it, leading to |
| * a BUG_ON() at btrfs_unpin_extent_range(). |
| */ |
| mutex_lock(&fs_info->unused_bg_unpin_mutex); |
| ret = clear_extent_bits(&fs_info->freed_extents[0], start, end, |
| EXTENT_DIRTY, GFP_NOFS); |
| if (ret) { |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| btrfs_dec_block_group_ro(root, block_group); |
| goto end_trans; |
| } |
| ret = clear_extent_bits(&fs_info->freed_extents[1], start, end, |
| EXTENT_DIRTY, GFP_NOFS); |
| if (ret) { |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| btrfs_dec_block_group_ro(root, block_group); |
| goto end_trans; |
| } |
| mutex_unlock(&fs_info->unused_bg_unpin_mutex); |
| |
| /* Reset pinned so btrfs_put_block_group doesn't complain */ |
| spin_lock(&space_info->lock); |
| spin_lock(&block_group->lock); |
| |
| space_info->bytes_pinned -= block_group->pinned; |
| space_info->bytes_readonly += block_group->pinned; |
| percpu_counter_add(&space_info->total_bytes_pinned, |
| -block_group->pinned); |
| block_group->pinned = 0; |
| |
| spin_unlock(&block_group->lock); |
| spin_unlock(&space_info->lock); |
| |
| /* DISCARD can flip during remount */ |
| trimming = btrfs_test_opt(root, DISCARD); |
| |
| /* Implicit trim during transaction commit. */ |
| if (trimming) |
| btrfs_get_block_group_trimming(block_group); |
| |
| /* |
| * Btrfs_remove_chunk will abort the transaction if things go |
| * horribly wrong. |
| */ |
| ret = btrfs_remove_chunk(trans, root, |
| block_group->key.objectid); |
| |
| if (ret) { |
| if (trimming) |
| btrfs_put_block_group_trimming(block_group); |
| goto end_trans; |
| } |
| |
| /* |
| * If we're not mounted with -odiscard, we can just forget |
| * about this block group. Otherwise we'll need to wait |
| * until transaction commit to do the actual discard. |
| */ |
| if (trimming) { |
| WARN_ON(!list_empty(&block_group->bg_list)); |
| spin_lock(&trans->transaction->deleted_bgs_lock); |
| list_move(&block_group->bg_list, |
| &trans->transaction->deleted_bgs); |
| spin_unlock(&trans->transaction->deleted_bgs_lock); |
| btrfs_get_block_group(block_group); |
| } |
| end_trans: |
| btrfs_end_transaction(trans, root); |
| next: |
| mutex_unlock(&root->fs_info->delete_unused_bgs_mutex); |
| btrfs_put_block_group(block_group); |
| spin_lock(&fs_info->unused_bgs_lock); |
| } |
| spin_unlock(&fs_info->unused_bgs_lock); |
| } |
| |
| int btrfs_init_space_info(struct btrfs_fs_info *fs_info) |
| { |
| struct btrfs_space_info *space_info; |
| struct btrfs_super_block *disk_super; |
| u64 features; |
| u64 flags; |
| int mixed = 0; |
| int ret; |
| |
| disk_super = fs_info->super_copy; |
| if (!btrfs_super_root(disk_super)) |
| return 1; |
| |
| features = btrfs_super_incompat_flags(disk_super); |
| if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) |
| mixed = 1; |
| |
| flags = BTRFS_BLOCK_GROUP_SYSTEM; |
| ret = update_space_info(fs_info, flags, 0, 0, &space_info); |
| if (ret) |
| goto out; |
| |
| if (mixed) { |
| flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; |
| ret = update_space_info(fs_info, flags, 0, 0, &space_info); |
| } else { |
| flags = BTRFS_BLOCK_GROUP_METADATA; |
| ret = update_space_info(fs_info, flags, 0, 0, &space_info); |
| if (ret) |
| goto out; |
| |
| flags = BTRFS_BLOCK_GROUP_DATA; |
| ret = update_space_info(fs_info, flags, 0, 0, &space_info); |
| } |
| out: |
| return ret; |
| } |
| |
| int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end) |
| { |
| return unpin_extent_range(root, start, end, false); |
| } |
| |
| /* |
| * It used to be that old block groups would be left around forever. |
| * Iterating over them would be enough to trim unused space. Since we |
| * now automatically remove them, we also need to iterate over unallocated |
| * space. |
| * |
| * We don't want a transaction for this since the discard may take a |
| * substantial amount of time. We don't require that a transaction be |
| * running, but we do need to take a running transaction into account |
| * to ensure that we're not discarding chunks that were released in |
| * the current transaction. |
| * |
| * Holding the chunks lock will prevent other threads from allocating |
| * or releasing chunks, but it won't prevent a running transaction |
| * from committing and releasing the memory that the pending chunks |
| * list head uses. For that, we need to take a reference to the |
| * transaction. |
| */ |
| static int btrfs_trim_free_extents(struct btrfs_device *device, |
| u64 minlen, u64 *trimmed) |
| { |
| u64 start = 0, len = 0; |
| int ret; |
| |
| *trimmed = 0; |
| |
| /* Not writeable = nothing to do. */ |
| if (!device->writeable) |
| return 0; |
| |
| /* No free space = nothing to do. */ |
| if (device->total_bytes <= device->bytes_used) |
| return 0; |
| |
| ret = 0; |
| |
| while (1) { |
| struct btrfs_fs_info *fs_info = device->dev_root->fs_info; |
| struct btrfs_transaction *trans; |
| u64 bytes; |
| |
| ret = mutex_lock_interruptible(&fs_info->chunk_mutex); |
| if (ret) |
| return ret; |
| |
| down_read(&fs_info->commit_root_sem); |
| |
| spin_lock(&fs_info->trans_lock); |
| trans = fs_info->running_transaction; |
| if (trans) |
| atomic_inc(&trans->use_count); |
| spin_unlock(&fs_info->trans_lock); |
| |
| ret = find_free_dev_extent_start(trans, device, minlen, start, |
| &start, &len); |
| if (trans) |
| btrfs_put_transaction(trans); |
| |
| if (ret) { |
| up_read(&fs_info->commit_root_sem); |
| mutex_unlock(&fs_info->chunk_mutex); |
| if (ret == -ENOSPC) |
| ret = 0; |
| break; |
| } |
| |
| ret = btrfs_issue_discard(device->bdev, start, len, &bytes); |
| up_read(&fs_info->commit_root_sem); |
| mutex_unlock(&fs_info->chunk_mutex); |
| |
| if (ret) |
| break; |
| |
| start += len; |
| *trimmed += bytes; |
| |
| if (fatal_signal_pending(current)) { |
| ret = -ERESTARTSYS; |
| break; |
| } |
| |
| cond_resched(); |
| } |
| |
| return ret; |
| } |
| |
| int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) |
| { |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| struct btrfs_block_group_cache *cache = NULL; |
| struct btrfs_device *device; |
| struct list_head *devices; |
| u64 group_trimmed; |
| u64 start; |
| u64 end; |
| u64 trimmed = 0; |
| u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); |
| int ret = 0; |
| |
| /* |
| * try to trim all FS space, our block group may start from non-zero. |
| */ |
| if (range->len == total_bytes) |
| cache = btrfs_lookup_first_block_group(fs_info, range->start); |
| else |
| cache = btrfs_lookup_block_group(fs_info, range->start); |
| |
| while (cache) { |
| if (cache->key.objectid >= (range->start + range->len)) { |
| btrfs_put_block_group(cache); |
| break; |
| } |
| |
| start = max(range->start, cache->key.objectid); |
| end = min(range->start + range->len, |
| cache->key.objectid + cache->key.offset); |
| |
| if (end - start >= range->minlen) { |
| if (!block_group_cache_done(cache)) { |
| ret = cache_block_group(cache, 0); |
| if (ret) { |
| btrfs_put_block_group(cache); |
| break; |
| } |
| ret = wait_block_group_cache_done(cache); |
| if (ret) { |
| btrfs_put_block_group(cache); |
| break; |
| } |
| } |
| ret = btrfs_trim_block_group(cache, |
| &group_trimmed, |
| start, |
| end, |
| range->minlen); |
| |
| trimmed += group_trimmed; |
| if (ret) { |
| btrfs_put_block_group(cache); |
| break; |
| } |
| } |
| |
| cache = next_block_group(fs_info->tree_root, cache); |
| } |
| |
| mutex_lock(&root->fs_info->fs_devices->device_list_mutex); |
| devices = &root->fs_info->fs_devices->alloc_list; |
| list_for_each_entry(device, devices, dev_alloc_list) { |
| ret = btrfs_trim_free_extents(device, range->minlen, |
| &group_trimmed); |
| if (ret) |
| break; |
| |
| trimmed += group_trimmed; |
| } |
| mutex_unlock(&root->fs_info->fs_devices->device_list_mutex); |
| |
| range->len = trimmed; |
| return ret; |
| } |
| |
| /* |
| * btrfs_{start,end}_write_no_snapshoting() are similar to |
| * mnt_{want,drop}_write(), they are used to prevent some tasks from writing |
| * data into the page cache through nocow before the subvolume is snapshoted, |
| * but flush the data into disk after the snapshot creation, or to prevent |
| * operations while snapshoting is ongoing and that cause the snapshot to be |
| * inconsistent (writes followed by expanding truncates for example). |
| */ |
| void btrfs_end_write_no_snapshoting(struct btrfs_root *root) |
| { |
| percpu_counter_dec(&root->subv_writers->counter); |
| /* |
| * Make sure counter is updated before we wake up |
| * waiters. |
| */ |
| smp_mb(); |
| if (waitqueue_active(&root->subv_writers->wait)) |
| wake_up(&root->subv_writers->wait); |
| } |
| |
| int btrfs_start_write_no_snapshoting(struct btrfs_root *root) |
| { |
| if (atomic_read(&root->will_be_snapshoted)) |
| return 0; |
| |
| percpu_counter_inc(&root->subv_writers->counter); |
| /* |
| * Make sure counter is updated before we check for snapshot creation. |
| */ |
| smp_mb(); |
| if (atomic_read(&root->will_be_snapshoted)) { |
| btrfs_end_write_no_snapshoting(root); |
| return 0; |
| } |
| return 1; |
| } |