| /* |
| * 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/crc32c.h> |
| #include <linux/pagemap.h> |
| #include "hash.h" |
| #include "ctree.h" |
| #include "disk-io.h" |
| #include "print-tree.h" |
| #include "transaction.h" |
| #include "volumes.h" |
| |
| #define BLOCK_GROUP_DATA EXTENT_WRITEBACK |
| #define BLOCK_GROUP_METADATA EXTENT_UPTODATE |
| #define BLOCK_GROUP_SYSTEM EXTENT_NEW |
| |
| #define BLOCK_GROUP_DIRTY EXTENT_DIRTY |
| |
| static int finish_current_insert(struct btrfs_trans_handle *trans, struct |
| btrfs_root *extent_root); |
| static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
| btrfs_root *extent_root); |
| int btrfs_make_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytes_used, |
| u64 type, u64 chunk_tree, u64 chunk_objectid, |
| u64 size); |
| |
| |
| static int cache_block_group(struct btrfs_root *root, |
| struct btrfs_block_group_cache *block_group) |
| { |
| struct btrfs_path *path; |
| int ret; |
| struct btrfs_key key; |
| struct extent_buffer *leaf; |
| struct extent_io_tree *free_space_cache; |
| int slot; |
| u64 last = 0; |
| u64 hole_size; |
| u64 first_free; |
| int found = 0; |
| |
| if (!block_group) |
| return 0; |
| |
| root = root->fs_info->extent_root; |
| free_space_cache = &root->fs_info->free_space_cache; |
| |
| if (block_group->cached) |
| return 0; |
| |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->reada = 2; |
| first_free = block_group->key.objectid; |
| key.objectid = block_group->key.objectid; |
| key.offset = 0; |
| btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| return ret; |
| ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); |
| if (ret < 0) |
| return ret; |
| if (ret == 0) { |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); |
| if (key.objectid + key.offset > first_free) |
| first_free = key.objectid + key.offset; |
| } |
| while(1) { |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| if (slot >= btrfs_header_nritems(leaf)) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| goto err; |
| if (ret == 0) { |
| continue; |
| } else { |
| break; |
| } |
| } |
| btrfs_item_key_to_cpu(leaf, &key, slot); |
| if (key.objectid < block_group->key.objectid) { |
| goto next; |
| } |
| if (key.objectid >= block_group->key.objectid + |
| block_group->key.offset) { |
| break; |
| } |
| |
| if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { |
| if (!found) { |
| last = first_free; |
| found = 1; |
| } |
| if (key.objectid > last) { |
| hole_size = key.objectid - last; |
| set_extent_dirty(free_space_cache, last, |
| last + hole_size - 1, |
| GFP_NOFS); |
| } |
| last = key.objectid + key.offset; |
| } |
| next: |
| path->slots[0]++; |
| } |
| |
| if (!found) |
| last = first_free; |
| if (block_group->key.objectid + |
| block_group->key.offset > last) { |
| hole_size = block_group->key.objectid + |
| block_group->key.offset - last; |
| set_extent_dirty(free_space_cache, last, |
| last + hole_size - 1, GFP_NOFS); |
| } |
| block_group->cached = 1; |
| err: |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| struct btrfs_block_group_cache *btrfs_lookup_block_group(struct |
| btrfs_fs_info *info, |
| u64 bytenr) |
| { |
| struct extent_io_tree *block_group_cache; |
| struct btrfs_block_group_cache *block_group = NULL; |
| u64 ptr; |
| u64 start; |
| u64 end; |
| int ret; |
| |
| block_group_cache = &info->block_group_cache; |
| ret = find_first_extent_bit(block_group_cache, |
| bytenr, &start, &end, |
| BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | |
| BLOCK_GROUP_SYSTEM); |
| if (ret) { |
| return NULL; |
| } |
| ret = get_state_private(block_group_cache, start, &ptr); |
| if (ret) |
| return NULL; |
| |
| block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| if (block_group->key.objectid <= bytenr && bytenr < |
| block_group->key.objectid + block_group->key.offset) |
| return block_group; |
| return NULL; |
| } |
| |
| static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) |
| { |
| return (cache->flags & bits); |
| } |
| |
| static int noinline find_search_start(struct btrfs_root *root, |
| struct btrfs_block_group_cache **cache_ret, |
| u64 *start_ret, int num, int data) |
| { |
| int ret; |
| struct btrfs_block_group_cache *cache = *cache_ret; |
| struct extent_io_tree *free_space_cache; |
| struct extent_state *state; |
| u64 last; |
| u64 start = 0; |
| u64 cache_miss = 0; |
| u64 total_fs_bytes; |
| u64 search_start = *start_ret; |
| int wrapped = 0; |
| |
| if (!cache) |
| goto out; |
| total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); |
| free_space_cache = &root->fs_info->free_space_cache; |
| |
| again: |
| ret = cache_block_group(root, cache); |
| if (ret) |
| goto out; |
| |
| last = max(search_start, cache->key.objectid); |
| if (!block_group_bits(cache, data)) { |
| goto new_group; |
| } |
| |
| spin_lock_irq(&free_space_cache->lock); |
| state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY); |
| while(1) { |
| if (!state) { |
| if (!cache_miss) |
| cache_miss = last; |
| spin_unlock_irq(&free_space_cache->lock); |
| goto new_group; |
| } |
| |
| start = max(last, state->start); |
| last = state->end + 1; |
| if (last - start < num) { |
| if (last == cache->key.objectid + cache->key.offset) |
| cache_miss = start; |
| do { |
| state = extent_state_next(state); |
| } while(state && !(state->state & EXTENT_DIRTY)); |
| continue; |
| } |
| spin_unlock_irq(&free_space_cache->lock); |
| if (start + num > cache->key.objectid + cache->key.offset) |
| goto new_group; |
| if (start + num > total_fs_bytes) |
| goto new_group; |
| *start_ret = start; |
| return 0; |
| } out: |
| cache = btrfs_lookup_block_group(root->fs_info, search_start); |
| if (!cache) { |
| printk("Unable to find block group for %Lu\n", search_start); |
| WARN_ON(1); |
| } |
| return -ENOSPC; |
| |
| new_group: |
| last = cache->key.objectid + cache->key.offset; |
| wrapped: |
| cache = btrfs_lookup_block_group(root->fs_info, last); |
| if (!cache || cache->key.objectid >= total_fs_bytes) { |
| no_cache: |
| if (!wrapped) { |
| wrapped = 1; |
| last = search_start; |
| goto wrapped; |
| } |
| goto out; |
| } |
| if (cache_miss && !cache->cached) { |
| cache_block_group(root, cache); |
| last = cache_miss; |
| cache = btrfs_lookup_block_group(root->fs_info, last); |
| } |
| cache = btrfs_find_block_group(root, cache, last, data, 0); |
| if (!cache) |
| goto no_cache; |
| *cache_ret = cache; |
| cache_miss = 0; |
| goto again; |
| } |
| |
| static u64 div_factor(u64 num, int factor) |
| { |
| if (factor == 10) |
| return num; |
| num *= factor; |
| do_div(num, 10); |
| return num; |
| } |
| |
| static int block_group_state_bits(u64 flags) |
| { |
| int bits = 0; |
| if (flags & BTRFS_BLOCK_GROUP_DATA) |
| bits |= BLOCK_GROUP_DATA; |
| if (flags & BTRFS_BLOCK_GROUP_METADATA) |
| bits |= BLOCK_GROUP_METADATA; |
| if (flags & BTRFS_BLOCK_GROUP_SYSTEM) |
| bits |= BLOCK_GROUP_SYSTEM; |
| return bits; |
| } |
| |
| struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, |
| struct btrfs_block_group_cache |
| *hint, u64 search_start, |
| int data, int owner) |
| { |
| struct btrfs_block_group_cache *cache; |
| struct extent_io_tree *block_group_cache; |
| struct btrfs_block_group_cache *found_group = NULL; |
| struct btrfs_fs_info *info = root->fs_info; |
| u64 used; |
| u64 last = 0; |
| u64 hint_last; |
| u64 start; |
| u64 end; |
| u64 free_check; |
| u64 ptr; |
| u64 total_fs_bytes; |
| int bit; |
| int ret; |
| int full_search = 0; |
| int factor = 8; |
| |
| block_group_cache = &info->block_group_cache; |
| total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); |
| |
| if (!owner) |
| factor = 8; |
| |
| bit = block_group_state_bits(data); |
| |
| if (search_start && search_start < total_fs_bytes) { |
| struct btrfs_block_group_cache *shint; |
| shint = btrfs_lookup_block_group(info, search_start); |
| if (shint && block_group_bits(shint, data)) { |
| used = btrfs_block_group_used(&shint->item); |
| if (used + shint->pinned < |
| div_factor(shint->key.offset, factor)) { |
| return shint; |
| } |
| } |
| } |
| if (hint && block_group_bits(hint, data) && |
| hint->key.objectid < total_fs_bytes) { |
| used = btrfs_block_group_used(&hint->item); |
| if (used + hint->pinned < |
| div_factor(hint->key.offset, factor)) { |
| return hint; |
| } |
| last = hint->key.objectid + hint->key.offset; |
| hint_last = last; |
| } else { |
| if (hint) |
| hint_last = max(hint->key.objectid, search_start); |
| else |
| hint_last = search_start; |
| |
| if (hint_last >= total_fs_bytes) |
| hint_last = search_start; |
| last = hint_last; |
| } |
| again: |
| while(1) { |
| ret = find_first_extent_bit(block_group_cache, last, |
| &start, &end, bit); |
| if (ret) |
| break; |
| |
| ret = get_state_private(block_group_cache, start, &ptr); |
| if (ret) |
| break; |
| |
| cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| last = cache->key.objectid + cache->key.offset; |
| used = btrfs_block_group_used(&cache->item); |
| |
| if (cache->key.objectid > total_fs_bytes) |
| break; |
| |
| if (full_search) |
| free_check = cache->key.offset; |
| else |
| free_check = div_factor(cache->key.offset, factor); |
| |
| if (used + cache->pinned < free_check) { |
| found_group = cache; |
| goto found; |
| } |
| cond_resched(); |
| } |
| if (!full_search) { |
| last = search_start; |
| full_search = 1; |
| goto again; |
| } |
| found: |
| return found_group; |
| } |
| |
| static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation, |
| u64 owner, u64 owner_offset) |
| { |
| u32 high_crc = ~(u32)0; |
| u32 low_crc = ~(u32)0; |
| __le64 lenum; |
| |
| lenum = cpu_to_le64(root_objectid); |
| high_crc = crc32c(high_crc, &lenum, sizeof(lenum)); |
| lenum = cpu_to_le64(ref_generation); |
| low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); |
| if (owner >= BTRFS_FIRST_FREE_OBJECTID) { |
| lenum = cpu_to_le64(owner); |
| low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); |
| lenum = cpu_to_le64(owner_offset); |
| low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); |
| } |
| return ((u64)high_crc << 32) | (u64)low_crc; |
| } |
| |
| static int match_extent_ref(struct extent_buffer *leaf, |
| struct btrfs_extent_ref *disk_ref, |
| struct btrfs_extent_ref *cpu_ref) |
| { |
| int ret; |
| int len; |
| |
| if (cpu_ref->objectid) |
| len = sizeof(*cpu_ref); |
| else |
| len = 2 * sizeof(u64); |
| ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref, |
| len); |
| return ret == 0; |
| } |
| |
| static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, u64 bytenr, |
| u64 root_objectid, |
| u64 ref_generation, u64 owner, |
| u64 owner_offset, int del) |
| { |
| u64 hash; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct btrfs_extent_ref ref; |
| struct extent_buffer *leaf; |
| struct btrfs_extent_ref *disk_ref; |
| int ret; |
| int ret2; |
| |
| btrfs_set_stack_ref_root(&ref, root_objectid); |
| btrfs_set_stack_ref_generation(&ref, ref_generation); |
| btrfs_set_stack_ref_objectid(&ref, owner); |
| btrfs_set_stack_ref_offset(&ref, owner_offset); |
| |
| hash = hash_extent_ref(root_objectid, ref_generation, owner, |
| owner_offset); |
| key.offset = hash; |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_REF_KEY; |
| |
| while (1) { |
| ret = btrfs_search_slot(trans, root, &key, path, |
| del ? -1 : 0, del); |
| if (ret < 0) |
| goto out; |
| leaf = path->nodes[0]; |
| if (ret != 0) { |
| u32 nritems = btrfs_header_nritems(leaf); |
| if (path->slots[0] >= nritems) { |
| ret2 = btrfs_next_leaf(root, path); |
| if (ret2) |
| goto out; |
| leaf = path->nodes[0]; |
| } |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid != bytenr || |
| found_key.type != BTRFS_EXTENT_REF_KEY) |
| goto out; |
| key.offset = found_key.offset; |
| if (del) { |
| btrfs_release_path(root, path); |
| continue; |
| } |
| } |
| disk_ref = btrfs_item_ptr(path->nodes[0], |
| path->slots[0], |
| struct btrfs_extent_ref); |
| if (match_extent_ref(path->nodes[0], disk_ref, &ref)) { |
| ret = 0; |
| goto out; |
| } |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| key.offset = found_key.offset + 1; |
| btrfs_release_path(root, path); |
| } |
| out: |
| 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. |
| * |
| * File extents can be referenced by: |
| * |
| * - multiple snapshots, subvolumes, or different generations in one subvol |
| * - different files inside a single subvolume (in theory, not implemented yet) |
| * - different offsets inside a file (bookend extents in file.c) |
| * |
| * The extent ref structure has fields for: |
| * |
| * - Objectid of the subvolume root |
| * - Generation number of the tree holding the reference |
| * - objectid of the file holding the reference |
| * - offset in the file corresponding to the key holding the reference |
| * |
| * When a file extent is allocated the fields are filled in: |
| * (root_key.objectid, trans->transid, inode objectid, offset in file) |
| * |
| * When a leaf is cow'd new references are added for every file extent found |
| * in the leaf. It looks the same as the create case, but trans->transid |
| * will be different when the block is cow'd. |
| * |
| * (root_key.objectid, trans->transid, inode objectid, offset in file) |
| * |
| * When a file extent is removed either during snapshot deletion or file |
| * truncation, the corresponding back reference is found |
| * by searching for: |
| * |
| * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), |
| * inode objectid, offset in file) |
| * |
| * Btree extents can be referenced by: |
| * |
| * - Different subvolumes |
| * - Different generations of the same subvolume |
| * |
| * Storing sufficient information for a full reverse mapping of a btree |
| * block would require storing the lowest key of the block in the backref, |
| * and it would require updating that lowest key either before write out or |
| * every time it changed. Instead, the objectid of the lowest key is stored |
| * along with the level of the tree block. This provides a hint |
| * about where in the btree the block can be found. Searches through the |
| * btree only need to look for a pointer to that block, so they stop one |
| * level higher than the level recorded in the backref. |
| * |
| * Some btrees do not do reference counting on their extents. These |
| * include the extent tree and the tree of tree roots. Backrefs for these |
| * trees always have a generation of zero. |
| * |
| * When a tree block is created, back references are inserted: |
| * |
| * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid) |
| * |
| * When a tree block is cow'd in a reference counted root, |
| * new back references are added for all the blocks it points to. |
| * These are of the form (trans->transid will have increased since creation): |
| * |
| * (root->root_key.objectid, trans->transid, level, lowest_key_objectid) |
| * |
| * Because the lowest_key_objectid and the level are just hints |
| * they are not used when backrefs are deleted. When a backref is deleted: |
| * |
| * if backref was for a tree root: |
| * root_objectid = root->root_key.objectid |
| * else |
| * root_objectid = btrfs_header_owner(parent) |
| * |
| * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0) |
| * |
| * Back Reference Key hashing: |
| * |
| * Back references have four fields, each 64 bits long. Unfortunately, |
| * This is hashed into a single 64 bit number and placed into the key offset. |
| * The key objectid corresponds to the first byte in the extent, and the |
| * key type is set to BTRFS_EXTENT_REF_KEY |
| */ |
| int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, u64 bytenr, |
| u64 root_objectid, u64 ref_generation, |
| u64 owner, u64 owner_offset) |
| { |
| u64 hash; |
| struct btrfs_key key; |
| struct btrfs_extent_ref ref; |
| struct btrfs_extent_ref *disk_ref; |
| int ret; |
| |
| btrfs_set_stack_ref_root(&ref, root_objectid); |
| btrfs_set_stack_ref_generation(&ref, ref_generation); |
| btrfs_set_stack_ref_objectid(&ref, owner); |
| btrfs_set_stack_ref_offset(&ref, owner_offset); |
| |
| hash = hash_extent_ref(root_objectid, ref_generation, owner, |
| owner_offset); |
| key.offset = hash; |
| key.objectid = bytenr; |
| key.type = BTRFS_EXTENT_REF_KEY; |
| |
| ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref)); |
| while (ret == -EEXIST) { |
| disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_ref); |
| if (match_extent_ref(path->nodes[0], disk_ref, &ref)) |
| goto out; |
| key.offset++; |
| btrfs_release_path(root, path); |
| ret = btrfs_insert_empty_item(trans, root, path, &key, |
| sizeof(ref)); |
| } |
| if (ret) |
| goto out; |
| disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_ref); |
| write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref, |
| sizeof(ref)); |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| out: |
| btrfs_release_path(root, path); |
| return ret; |
| } |
| |
| int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, |
| u64 root_objectid, u64 ref_generation, |
| u64 owner, u64 owner_offset) |
| { |
| struct btrfs_path *path; |
| int ret; |
| struct btrfs_key key; |
| struct extent_buffer *l; |
| struct btrfs_extent_item *item; |
| u32 refs; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->reada = 0; |
| key.objectid = bytenr; |
| btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| key.offset = num_bytes; |
| ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
| 0, 1); |
| if (ret < 0) |
| return ret; |
| if (ret != 0) { |
| BUG(); |
| } |
| BUG_ON(ret != 0); |
| l = path->nodes[0]; |
| item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); |
| refs = btrfs_extent_refs(l, item); |
| btrfs_set_extent_refs(l, item, refs + 1); |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| |
| btrfs_release_path(root->fs_info->extent_root, path); |
| |
| path->reada = 0; |
| ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root, |
| path, bytenr, root_objectid, |
| ref_generation, owner, owner_offset); |
| BUG_ON(ret); |
| finish_current_insert(trans, root->fs_info->extent_root); |
| del_pending_extents(trans, root->fs_info->extent_root); |
| |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| int btrfs_extent_post_op(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| finish_current_insert(trans, root->fs_info->extent_root); |
| del_pending_extents(trans, root->fs_info->extent_root); |
| return 0; |
| } |
| |
| static int lookup_extent_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytenr, |
| u64 num_bytes, u32 *refs) |
| { |
| struct btrfs_path *path; |
| int ret; |
| struct btrfs_key key; |
| struct extent_buffer *l; |
| struct btrfs_extent_item *item; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| path = btrfs_alloc_path(); |
| path->reada = 0; |
| key.objectid = bytenr; |
| key.offset = num_bytes; |
| btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, |
| 0, 0); |
| if (ret < 0) |
| goto out; |
| if (ret != 0) { |
| btrfs_print_leaf(root, path->nodes[0]); |
| printk("failed to find block number %Lu\n", bytenr); |
| BUG(); |
| } |
| l = path->nodes[0]; |
| item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); |
| *refs = btrfs_extent_refs(l, item); |
| out: |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| u32 btrfs_count_snapshots_in_path(struct btrfs_root *root, |
| struct btrfs_path *count_path, |
| u64 first_extent) |
| { |
| struct btrfs_root *extent_root = root->fs_info->extent_root; |
| struct btrfs_path *path; |
| u64 bytenr; |
| u64 found_objectid; |
| u64 root_objectid = root->root_key.objectid; |
| u32 total_count = 0; |
| u32 cur_count; |
| u32 nritems; |
| int ret; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct extent_buffer *l; |
| struct btrfs_extent_item *item; |
| struct btrfs_extent_ref *ref_item; |
| int level = -1; |
| |
| path = btrfs_alloc_path(); |
| again: |
| if (level == -1) |
| bytenr = first_extent; |
| else |
| bytenr = count_path->nodes[level]->start; |
| |
| cur_count = 0; |
| key.objectid = bytenr; |
| key.offset = 0; |
| |
| btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| BUG_ON(ret == 0); |
| |
| l = path->nodes[0]; |
| btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); |
| |
| if (found_key.objectid != bytenr || |
| found_key.type != BTRFS_EXTENT_ITEM_KEY) { |
| goto out; |
| } |
| |
| item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); |
| while (1) { |
| l = path->nodes[0]; |
| nritems = btrfs_header_nritems(l); |
| if (path->slots[0] >= nritems) { |
| ret = btrfs_next_leaf(extent_root, path); |
| if (ret == 0) |
| continue; |
| break; |
| } |
| btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); |
| if (found_key.objectid != bytenr) |
| break; |
| |
| if (found_key.type != BTRFS_EXTENT_REF_KEY) { |
| path->slots[0]++; |
| continue; |
| } |
| |
| cur_count++; |
| ref_item = btrfs_item_ptr(l, path->slots[0], |
| struct btrfs_extent_ref); |
| found_objectid = btrfs_ref_root(l, ref_item); |
| |
| if (found_objectid != root_objectid) { |
| total_count = 2; |
| goto out; |
| } |
| total_count = 1; |
| path->slots[0]++; |
| } |
| if (cur_count == 0) { |
| total_count = 0; |
| goto out; |
| } |
| if (level >= 0 && root->node == count_path->nodes[level]) |
| goto out; |
| level++; |
| btrfs_release_path(root, path); |
| goto again; |
| |
| out: |
| btrfs_free_path(path); |
| return total_count; |
| } |
| int btrfs_inc_root_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 owner_objectid) |
| { |
| u64 generation; |
| u64 key_objectid; |
| u64 level; |
| u32 nritems; |
| struct btrfs_disk_key disk_key; |
| |
| level = btrfs_header_level(root->node); |
| generation = trans->transid; |
| nritems = btrfs_header_nritems(root->node); |
| if (nritems > 0) { |
| if (level == 0) |
| btrfs_item_key(root->node, &disk_key, 0); |
| else |
| btrfs_node_key(root->node, &disk_key, 0); |
| key_objectid = btrfs_disk_key_objectid(&disk_key); |
| } else { |
| key_objectid = 0; |
| } |
| return btrfs_inc_extent_ref(trans, root, root->node->start, |
| root->node->len, owner_objectid, |
| generation, level, key_objectid); |
| } |
| |
| int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct extent_buffer *buf) |
| { |
| u64 bytenr; |
| u32 nritems; |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| int i; |
| int level; |
| int ret; |
| int faili; |
| |
| if (!root->ref_cows) |
| return 0; |
| |
| level = btrfs_header_level(buf); |
| nritems = btrfs_header_nritems(buf); |
| for (i = 0; i < nritems; i++) { |
| if (level == 0) { |
| u64 disk_bytenr; |
| btrfs_item_key_to_cpu(buf, &key, i); |
| if (btrfs_key_type(&key) != 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; |
| disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| if (disk_bytenr == 0) |
| continue; |
| ret = btrfs_inc_extent_ref(trans, root, disk_bytenr, |
| btrfs_file_extent_disk_num_bytes(buf, fi), |
| root->root_key.objectid, trans->transid, |
| key.objectid, key.offset); |
| if (ret) { |
| faili = i; |
| goto fail; |
| } |
| } else { |
| bytenr = btrfs_node_blockptr(buf, i); |
| btrfs_node_key_to_cpu(buf, &key, i); |
| ret = btrfs_inc_extent_ref(trans, root, bytenr, |
| btrfs_level_size(root, level - 1), |
| root->root_key.objectid, |
| trans->transid, |
| level - 1, key.objectid); |
| if (ret) { |
| faili = i; |
| goto fail; |
| } |
| } |
| } |
| return 0; |
| fail: |
| WARN_ON(1); |
| #if 0 |
| for (i =0; i < faili; i++) { |
| if (level == 0) { |
| u64 disk_bytenr; |
| btrfs_item_key_to_cpu(buf, &key, i); |
| if (btrfs_key_type(&key) != 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; |
| disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); |
| if (disk_bytenr == 0) |
| continue; |
| err = btrfs_free_extent(trans, root, disk_bytenr, |
| btrfs_file_extent_disk_num_bytes(buf, |
| fi), 0); |
| BUG_ON(err); |
| } else { |
| bytenr = btrfs_node_blockptr(buf, i); |
| err = btrfs_free_extent(trans, root, bytenr, |
| btrfs_level_size(root, level - 1), 0); |
| BUG_ON(err); |
| } |
| } |
| #endif |
| return ret; |
| } |
| |
| 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; |
| int pending_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 < 0) |
| goto fail; |
| BUG_ON(ret); |
| |
| 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); |
| btrfs_release_path(extent_root, path); |
| fail: |
| finish_current_insert(trans, extent_root); |
| pending_ret = del_pending_extents(trans, extent_root); |
| if (ret) |
| return ret; |
| if (pending_ret) |
| return pending_ret; |
| return 0; |
| |
| } |
| |
| int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root) |
| { |
| struct extent_io_tree *block_group_cache; |
| struct btrfs_block_group_cache *cache; |
| int ret; |
| int err = 0; |
| int werr = 0; |
| struct btrfs_path *path; |
| u64 last = 0; |
| u64 start; |
| u64 end; |
| u64 ptr; |
| |
| block_group_cache = &root->fs_info->block_group_cache; |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| while(1) { |
| ret = find_first_extent_bit(block_group_cache, last, |
| &start, &end, BLOCK_GROUP_DIRTY); |
| if (ret) |
| break; |
| |
| last = end + 1; |
| ret = get_state_private(block_group_cache, start, &ptr); |
| if (ret) |
| break; |
| |
| cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; |
| err = write_one_cache_group(trans, root, |
| path, cache); |
| /* |
| * if we fail to write the cache group, we want |
| * to keep it marked dirty in hopes that a later |
| * write will work |
| */ |
| if (err) { |
| werr = err; |
| continue; |
| } |
| clear_extent_bits(block_group_cache, start, end, |
| BLOCK_GROUP_DIRTY, GFP_NOFS); |
| } |
| btrfs_free_path(path); |
| return werr; |
| } |
| |
| static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, |
| u64 flags) |
| { |
| struct list_head *head = &info->space_info; |
| struct list_head *cur; |
| struct btrfs_space_info *found; |
| list_for_each(cur, head) { |
| found = list_entry(cur, struct btrfs_space_info, list); |
| if (found->flags == flags) |
| return found; |
| } |
| return NULL; |
| |
| } |
| |
| static int do_chunk_alloc(struct btrfs_trans_handle *trans, |
| struct btrfs_root *extent_root, u64 alloc_bytes, |
| u64 flags) |
| { |
| struct btrfs_space_info *space_info; |
| u64 thresh; |
| u64 start; |
| u64 num_bytes; |
| int ret; |
| |
| space_info = __find_space_info(extent_root->fs_info, flags); |
| BUG_ON(!space_info); |
| |
| if (space_info->full) |
| return 0; |
| |
| thresh = div_factor(space_info->total_bytes, 7); |
| if ((space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) < |
| thresh) |
| return 0; |
| |
| ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags); |
| if (ret == -ENOSPC) { |
| printk("space info full %Lu\n", flags); |
| space_info->full = 1; |
| return 0; |
| } |
| |
| BUG_ON(ret); |
| |
| ret = btrfs_make_block_group(trans, extent_root, 0, flags, |
| extent_root->fs_info->chunk_root->root_key.objectid, |
| start, num_bytes); |
| BUG_ON(ret); |
| return 0; |
| } |
| |
| static int update_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 bytenr, u64 num_bytes, int alloc, |
| int mark_free) |
| { |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_fs_info *info = root->fs_info; |
| u64 total = num_bytes; |
| u64 old_val; |
| u64 byte_in_group; |
| u64 start; |
| u64 end; |
| |
| while(total) { |
| cache = btrfs_lookup_block_group(info, bytenr); |
| if (!cache) { |
| return -1; |
| } |
| byte_in_group = bytenr - cache->key.objectid; |
| WARN_ON(byte_in_group > cache->key.offset); |
| start = cache->key.objectid; |
| end = start + cache->key.offset - 1; |
| set_extent_bits(&info->block_group_cache, start, end, |
| BLOCK_GROUP_DIRTY, GFP_NOFS); |
| |
| old_val = btrfs_block_group_used(&cache->item); |
| num_bytes = min(total, cache->key.offset - byte_in_group); |
| if (alloc) { |
| old_val += num_bytes; |
| cache->space_info->bytes_used += num_bytes; |
| } else { |
| old_val -= num_bytes; |
| cache->space_info->bytes_used -= num_bytes; |
| if (mark_free) { |
| set_extent_dirty(&info->free_space_cache, |
| bytenr, bytenr + num_bytes - 1, |
| GFP_NOFS); |
| } |
| } |
| btrfs_set_block_group_used(&cache->item, old_val); |
| total -= num_bytes; |
| bytenr += num_bytes; |
| } |
| return 0; |
| } |
| |
| static int update_pinned_extents(struct btrfs_root *root, |
| u64 bytenr, u64 num, int pin) |
| { |
| u64 len; |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_fs_info *fs_info = root->fs_info; |
| |
| if (pin) { |
| set_extent_dirty(&fs_info->pinned_extents, |
| bytenr, bytenr + num - 1, GFP_NOFS); |
| } else { |
| clear_extent_dirty(&fs_info->pinned_extents, |
| bytenr, bytenr + num - 1, GFP_NOFS); |
| } |
| while (num > 0) { |
| cache = btrfs_lookup_block_group(fs_info, bytenr); |
| WARN_ON(!cache); |
| len = min(num, cache->key.offset - |
| (bytenr - cache->key.objectid)); |
| if (pin) { |
| cache->pinned += len; |
| cache->space_info->bytes_pinned += len; |
| fs_info->total_pinned += len; |
| } else { |
| cache->pinned -= len; |
| cache->space_info->bytes_pinned -= len; |
| fs_info->total_pinned -= len; |
| } |
| bytenr += len; |
| num -= len; |
| } |
| return 0; |
| } |
| |
| int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) |
| { |
| u64 last = 0; |
| u64 start; |
| u64 end; |
| struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; |
| int ret; |
| |
| while(1) { |
| ret = find_first_extent_bit(pinned_extents, last, |
| &start, &end, EXTENT_DIRTY); |
| if (ret) |
| break; |
| set_extent_dirty(copy, start, end, GFP_NOFS); |
| last = end + 1; |
| } |
| return 0; |
| } |
| |
| int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_io_tree *unpin) |
| { |
| u64 start; |
| u64 end; |
| int ret; |
| struct extent_io_tree *free_space_cache; |
| free_space_cache = &root->fs_info->free_space_cache; |
| |
| while(1) { |
| ret = find_first_extent_bit(unpin, 0, &start, &end, |
| EXTENT_DIRTY); |
| if (ret) |
| break; |
| update_pinned_extents(root, start, end + 1 - start, 0); |
| clear_extent_dirty(unpin, start, end, GFP_NOFS); |
| set_extent_dirty(free_space_cache, start, end, GFP_NOFS); |
| } |
| return 0; |
| } |
| |
| static int finish_current_insert(struct btrfs_trans_handle *trans, |
| struct btrfs_root *extent_root) |
| { |
| u64 start; |
| u64 end; |
| struct btrfs_fs_info *info = extent_root->fs_info; |
| struct extent_buffer *eb; |
| struct btrfs_path *path; |
| struct btrfs_key ins; |
| struct btrfs_disk_key first; |
| struct btrfs_extent_item extent_item; |
| int ret; |
| int level; |
| int err = 0; |
| |
| btrfs_set_stack_extent_refs(&extent_item, 1); |
| btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); |
| path = btrfs_alloc_path(); |
| |
| while(1) { |
| ret = find_first_extent_bit(&info->extent_ins, 0, &start, |
| &end, EXTENT_LOCKED); |
| if (ret) |
| break; |
| |
| ins.objectid = start; |
| ins.offset = end + 1 - start; |
| err = btrfs_insert_item(trans, extent_root, &ins, |
| &extent_item, sizeof(extent_item)); |
| clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED, |
| GFP_NOFS); |
| eb = read_tree_block(extent_root, ins.objectid, ins.offset); |
| level = btrfs_header_level(eb); |
| if (level == 0) { |
| btrfs_item_key(eb, &first, 0); |
| } else { |
| btrfs_node_key(eb, &first, 0); |
| } |
| err = btrfs_insert_extent_backref(trans, extent_root, path, |
| start, extent_root->root_key.objectid, |
| 0, level, |
| btrfs_disk_key_objectid(&first)); |
| BUG_ON(err); |
| free_extent_buffer(eb); |
| } |
| btrfs_free_path(path); |
| return 0; |
| } |
| |
| static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes, |
| int pending) |
| { |
| int err = 0; |
| struct extent_buffer *buf; |
| |
| if (!pending) { |
| buf = btrfs_find_tree_block(root, bytenr, num_bytes); |
| if (buf) { |
| if (btrfs_buffer_uptodate(buf)) { |
| u64 transid = |
| root->fs_info->running_transaction->transid; |
| u64 header_transid = |
| btrfs_header_generation(buf); |
| if (header_transid == transid) { |
| clean_tree_block(NULL, root, buf); |
| free_extent_buffer(buf); |
| return 1; |
| } |
| } |
| free_extent_buffer(buf); |
| } |
| update_pinned_extents(root, bytenr, num_bytes, 1); |
| } else { |
| set_extent_bits(&root->fs_info->pending_del, |
| bytenr, bytenr + num_bytes - 1, |
| EXTENT_LOCKED, GFP_NOFS); |
| } |
| BUG_ON(err < 0); |
| return 0; |
| } |
| |
| /* |
| * remove an extent from the root, returns 0 on success |
| */ |
| static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, u64 bytenr, u64 num_bytes, |
| u64 root_objectid, u64 ref_generation, |
| u64 owner_objectid, u64 owner_offset, int pin, |
| int mark_free) |
| { |
| struct btrfs_path *path; |
| struct btrfs_key key; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_root *extent_root = info->extent_root; |
| struct extent_buffer *leaf; |
| int ret; |
| int extent_slot = 0; |
| int found_extent = 0; |
| int num_to_del = 1; |
| struct btrfs_extent_item *ei; |
| u32 refs; |
| |
| key.objectid = bytenr; |
| btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); |
| key.offset = num_bytes; |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| path->reada = 0; |
| ret = lookup_extent_backref(trans, extent_root, path, |
| bytenr, root_objectid, |
| ref_generation, |
| owner_objectid, owner_offset, 1); |
| if (ret == 0) { |
| struct btrfs_key found_key; |
| extent_slot = path->slots[0]; |
| while(extent_slot > 0) { |
| extent_slot--; |
| btrfs_item_key_to_cpu(path->nodes[0], &found_key, |
| extent_slot); |
| if (found_key.objectid != bytenr) |
| break; |
| if (found_key.type == BTRFS_EXTENT_ITEM_KEY && |
| found_key.offset == num_bytes) { |
| found_extent = 1; |
| break; |
| } |
| if (path->slots[0] - extent_slot > 5) |
| break; |
| } |
| if (!found_extent) |
| ret = btrfs_del_item(trans, extent_root, path); |
| } else { |
| btrfs_print_leaf(extent_root, path->nodes[0]); |
| WARN_ON(1); |
| printk("Unable to find ref byte nr %Lu root %Lu " |
| " gen %Lu owner %Lu offset %Lu\n", bytenr, |
| root_objectid, ref_generation, owner_objectid, |
| owner_offset); |
| } |
| if (!found_extent) { |
| btrfs_release_path(extent_root, path); |
| ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret); |
| extent_slot = path->slots[0]; |
| } |
| |
| leaf = path->nodes[0]; |
| ei = btrfs_item_ptr(leaf, extent_slot, |
| struct btrfs_extent_item); |
| refs = btrfs_extent_refs(leaf, ei); |
| BUG_ON(refs == 0); |
| refs -= 1; |
| btrfs_set_extent_refs(leaf, ei, refs); |
| |
| btrfs_mark_buffer_dirty(leaf); |
| |
| if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) { |
| /* if the back ref and the extent are next to each other |
| * they get deleted below in one shot |
| */ |
| path->slots[0] = extent_slot; |
| num_to_del = 2; |
| } else if (found_extent) { |
| /* otherwise delete the extent back ref */ |
| ret = btrfs_del_item(trans, extent_root, path); |
| BUG_ON(ret); |
| /* if refs are 0, we need to setup the path for deletion */ |
| if (refs == 0) { |
| btrfs_release_path(extent_root, path); |
| ret = btrfs_search_slot(trans, extent_root, &key, path, |
| -1, 1); |
| if (ret < 0) |
| return ret; |
| BUG_ON(ret); |
| } |
| } |
| |
| if (refs == 0) { |
| u64 super_used; |
| u64 root_used; |
| |
| if (pin) { |
| ret = pin_down_bytes(root, bytenr, num_bytes, 0); |
| if (ret > 0) |
| mark_free = 1; |
| BUG_ON(ret < 0); |
| } |
| |
| /* block accounting for super block */ |
| super_used = btrfs_super_bytes_used(&info->super_copy); |
| btrfs_set_super_bytes_used(&info->super_copy, |
| super_used - num_bytes); |
| |
| /* block accounting for root item */ |
| root_used = btrfs_root_used(&root->root_item); |
| btrfs_set_root_used(&root->root_item, |
| root_used - num_bytes); |
| ret = btrfs_del_items(trans, extent_root, path, path->slots[0], |
| num_to_del); |
| if (ret) { |
| return ret; |
| } |
| ret = update_block_group(trans, root, bytenr, num_bytes, 0, |
| mark_free); |
| BUG_ON(ret); |
| } |
| btrfs_free_path(path); |
| finish_current_insert(trans, extent_root); |
| return ret; |
| } |
| |
| /* |
| * find all the blocks marked as pending in the radix tree and remove |
| * them from the extent map |
| */ |
| static int del_pending_extents(struct btrfs_trans_handle *trans, struct |
| btrfs_root *extent_root) |
| { |
| int ret; |
| int err = 0; |
| u64 start; |
| u64 end; |
| struct extent_io_tree *pending_del; |
| struct extent_io_tree *pinned_extents; |
| |
| pending_del = &extent_root->fs_info->pending_del; |
| pinned_extents = &extent_root->fs_info->pinned_extents; |
| |
| while(1) { |
| ret = find_first_extent_bit(pending_del, 0, &start, &end, |
| EXTENT_LOCKED); |
| if (ret) |
| break; |
| update_pinned_extents(extent_root, start, end + 1 - start, 1); |
| clear_extent_bits(pending_del, start, end, EXTENT_LOCKED, |
| GFP_NOFS); |
| ret = __free_extent(trans, extent_root, |
| start, end + 1 - start, |
| extent_root->root_key.objectid, |
| 0, 0, 0, 0, 0); |
| if (ret) |
| err = ret; |
| } |
| return err; |
| } |
| |
| /* |
| * remove an extent from the root, returns 0 on success |
| */ |
| int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, u64 bytenr, u64 num_bytes, |
| u64 root_objectid, u64 ref_generation, |
| u64 owner_objectid, u64 owner_offset, int pin) |
| { |
| struct btrfs_root *extent_root = root->fs_info->extent_root; |
| int pending_ret; |
| int ret; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| if (!root->ref_cows) |
| ref_generation = 0; |
| |
| if (root == extent_root) { |
| pin_down_bytes(root, bytenr, num_bytes, 1); |
| return 0; |
| } |
| ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid, |
| ref_generation, owner_objectid, owner_offset, |
| pin, pin == 0); |
| pending_ret = del_pending_extents(trans, root->fs_info->extent_root); |
| return ret ? ret : pending_ret; |
| } |
| |
| static u64 stripe_align(struct btrfs_root *root, u64 val) |
| { |
| u64 mask = ((u64)root->stripesize - 1); |
| u64 ret = (val + mask) & ~mask; |
| return ret; |
| } |
| |
| /* |
| * 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 == block start |
| * ins->flags = BTRFS_EXTENT_ITEM_KEY |
| * ins->offset == number of blocks |
| * Any available blocks before search_start are skipped. |
| */ |
| static int noinline find_free_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *orig_root, |
| u64 num_bytes, u64 empty_size, |
| u64 search_start, u64 search_end, |
| u64 hint_byte, struct btrfs_key *ins, |
| u64 exclude_start, u64 exclude_nr, |
| int data) |
| { |
| int ret; |
| u64 orig_search_start = search_start; |
| struct btrfs_root * root = orig_root->fs_info->extent_root; |
| struct btrfs_fs_info *info = root->fs_info; |
| u64 total_needed = num_bytes; |
| u64 *last_ptr = NULL; |
| struct btrfs_block_group_cache *block_group; |
| int full_scan = 0; |
| int wrapped = 0; |
| int empty_cluster = 2 * 1024 * 1024; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); |
| |
| if (data & BTRFS_BLOCK_GROUP_METADATA) { |
| last_ptr = &root->fs_info->last_alloc; |
| } |
| |
| if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) { |
| last_ptr = &root->fs_info->last_data_alloc; |
| } |
| |
| if (last_ptr) { |
| if (*last_ptr) |
| hint_byte = *last_ptr; |
| else { |
| empty_size += empty_cluster; |
| } |
| } |
| |
| if (search_end == (u64)-1) |
| search_end = btrfs_super_total_bytes(&info->super_copy); |
| |
| if (hint_byte) { |
| block_group = btrfs_lookup_block_group(info, hint_byte); |
| if (!block_group) |
| hint_byte = search_start; |
| block_group = btrfs_find_block_group(root, block_group, |
| hint_byte, data, 1); |
| if (last_ptr && *last_ptr == 0 && block_group) |
| hint_byte = block_group->key.objectid; |
| } else { |
| block_group = btrfs_find_block_group(root, |
| trans->block_group, |
| search_start, data, 1); |
| } |
| search_start = max(search_start, hint_byte); |
| |
| total_needed += empty_size; |
| |
| check_failed: |
| if (!block_group) { |
| block_group = btrfs_lookup_block_group(info, search_start); |
| if (!block_group) |
| block_group = btrfs_lookup_block_group(info, |
| orig_search_start); |
| } |
| ret = find_search_start(root, &block_group, &search_start, |
| total_needed, data); |
| if (ret == -ENOSPC && last_ptr && *last_ptr) { |
| *last_ptr = 0; |
| block_group = btrfs_lookup_block_group(info, |
| orig_search_start); |
| search_start = orig_search_start; |
| ret = find_search_start(root, &block_group, &search_start, |
| total_needed, data); |
| } |
| if (ret == -ENOSPC) |
| goto enospc; |
| if (ret) |
| goto error; |
| |
| if (last_ptr && *last_ptr && search_start != *last_ptr) { |
| *last_ptr = 0; |
| if (!empty_size) { |
| empty_size += empty_cluster; |
| total_needed += empty_size; |
| } |
| block_group = btrfs_lookup_block_group(info, |
| orig_search_start); |
| search_start = orig_search_start; |
| ret = find_search_start(root, &block_group, |
| &search_start, total_needed, data); |
| if (ret == -ENOSPC) |
| goto enospc; |
| if (ret) |
| goto error; |
| } |
| |
| search_start = stripe_align(root, search_start); |
| ins->objectid = search_start; |
| ins->offset = num_bytes; |
| |
| if (ins->objectid + num_bytes >= search_end) |
| goto enospc; |
| |
| if (ins->objectid + num_bytes > |
| block_group->key.objectid + block_group->key.offset) { |
| search_start = block_group->key.objectid + |
| block_group->key.offset; |
| goto new_group; |
| } |
| |
| if (test_range_bit(&info->extent_ins, ins->objectid, |
| ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) { |
| search_start = ins->objectid + num_bytes; |
| goto new_group; |
| } |
| |
| if (test_range_bit(&info->pinned_extents, ins->objectid, |
| ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) { |
| search_start = ins->objectid + num_bytes; |
| goto new_group; |
| } |
| |
| if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start && |
| ins->objectid < exclude_start + exclude_nr)) { |
| search_start = exclude_start + exclude_nr; |
| goto new_group; |
| } |
| |
| if (!(data & BTRFS_BLOCK_GROUP_DATA)) { |
| block_group = btrfs_lookup_block_group(info, ins->objectid); |
| if (block_group) |
| trans->block_group = block_group; |
| } |
| ins->offset = num_bytes; |
| if (last_ptr) { |
| *last_ptr = ins->objectid + ins->offset; |
| if (*last_ptr == |
| btrfs_super_total_bytes(&root->fs_info->super_copy)) { |
| *last_ptr = 0; |
| } |
| } |
| return 0; |
| |
| new_group: |
| if (search_start + num_bytes >= search_end) { |
| enospc: |
| search_start = orig_search_start; |
| if (full_scan) { |
| ret = -ENOSPC; |
| goto error; |
| } |
| if (wrapped) { |
| if (!full_scan) |
| total_needed -= empty_size; |
| full_scan = 1; |
| } else |
| wrapped = 1; |
| } |
| block_group = btrfs_lookup_block_group(info, search_start); |
| cond_resched(); |
| block_group = btrfs_find_block_group(root, block_group, |
| search_start, data, 0); |
| goto check_failed; |
| |
| error: |
| return ret; |
| } |
| /* |
| * finds a free extent and does all the dirty work required for allocation |
| * returns the key for the extent through ins, and a tree buffer for |
| * the first block of the extent through buf. |
| * |
| * returns 0 if everything worked, non-zero otherwise. |
| */ |
| int btrfs_alloc_extent(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u64 num_bytes, u64 root_objectid, u64 ref_generation, |
| u64 owner, u64 owner_offset, |
| u64 empty_size, u64 hint_byte, |
| u64 search_end, struct btrfs_key *ins, int data) |
| { |
| int ret; |
| int pending_ret; |
| u64 super_used; |
| u64 root_used; |
| u64 search_start = 0; |
| u64 new_hint; |
| u32 sizes[2]; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_root *extent_root = info->extent_root; |
| struct btrfs_extent_item *extent_item; |
| struct btrfs_extent_ref *ref; |
| struct btrfs_path *path; |
| struct btrfs_key keys[2]; |
| |
| if (data) { |
| data = BTRFS_BLOCK_GROUP_DATA; |
| } else if (root == root->fs_info->chunk_root) { |
| data = BTRFS_BLOCK_GROUP_SYSTEM; |
| } else { |
| data = BTRFS_BLOCK_GROUP_METADATA; |
| } |
| |
| if (root->ref_cows) { |
| if (data != BTRFS_BLOCK_GROUP_METADATA) { |
| ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| 2 * 1024 * 1024, |
| BTRFS_BLOCK_GROUP_METADATA); |
| BUG_ON(ret); |
| } |
| ret = do_chunk_alloc(trans, root->fs_info->extent_root, |
| num_bytes + 2 * 1024 * 1024, data); |
| BUG_ON(ret); |
| } |
| |
| new_hint = max(hint_byte, root->fs_info->alloc_start); |
| if (new_hint < btrfs_super_total_bytes(&info->super_copy)) |
| hint_byte = new_hint; |
| |
| WARN_ON(num_bytes < root->sectorsize); |
| ret = find_free_extent(trans, root, num_bytes, empty_size, |
| search_start, search_end, hint_byte, ins, |
| trans->alloc_exclude_start, |
| trans->alloc_exclude_nr, data); |
| BUG_ON(ret); |
| if (ret) |
| return ret; |
| |
| /* block accounting for super block */ |
| super_used = btrfs_super_bytes_used(&info->super_copy); |
| btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); |
| |
| /* block accounting for root item */ |
| root_used = btrfs_root_used(&root->root_item); |
| btrfs_set_root_used(&root->root_item, root_used + num_bytes); |
| |
| clear_extent_dirty(&root->fs_info->free_space_cache, |
| ins->objectid, ins->objectid + ins->offset - 1, |
| GFP_NOFS); |
| |
| if (root == extent_root) { |
| set_extent_bits(&root->fs_info->extent_ins, ins->objectid, |
| ins->objectid + ins->offset - 1, |
| EXTENT_LOCKED, GFP_NOFS); |
| goto update_block; |
| } |
| |
| WARN_ON(trans->alloc_exclude_nr); |
| trans->alloc_exclude_start = ins->objectid; |
| trans->alloc_exclude_nr = ins->offset; |
| |
| memcpy(&keys[0], ins, sizeof(*ins)); |
| keys[1].offset = hash_extent_ref(root_objectid, ref_generation, |
| owner, owner_offset); |
| keys[1].objectid = ins->objectid; |
| keys[1].type = BTRFS_EXTENT_REF_KEY; |
| sizes[0] = sizeof(*extent_item); |
| sizes[1] = sizeof(*ref); |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| |
| ret = btrfs_insert_empty_items(trans, extent_root, path, keys, |
| sizes, 2); |
| |
| BUG_ON(ret); |
| extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_item); |
| btrfs_set_extent_refs(path->nodes[0], extent_item, 1); |
| ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, |
| struct btrfs_extent_ref); |
| |
| btrfs_set_ref_root(path->nodes[0], ref, root_objectid); |
| btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); |
| btrfs_set_ref_objectid(path->nodes[0], ref, owner); |
| btrfs_set_ref_offset(path->nodes[0], ref, owner_offset); |
| |
| btrfs_mark_buffer_dirty(path->nodes[0]); |
| |
| trans->alloc_exclude_start = 0; |
| trans->alloc_exclude_nr = 0; |
| btrfs_free_path(path); |
| finish_current_insert(trans, extent_root); |
| pending_ret = del_pending_extents(trans, extent_root); |
| |
| if (ret) { |
| return ret; |
| } |
| if (pending_ret) { |
| return pending_ret; |
| } |
| |
| update_block: |
| ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); |
| if (ret) { |
| printk("update block group failed for %Lu %Lu\n", |
| ins->objectid, ins->offset); |
| BUG(); |
| } |
| return 0; |
| } |
| |
| /* |
| * helper function to allocate a block for a given tree |
| * returns the tree buffer or NULL. |
| */ |
| struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u32 blocksize, |
| u64 root_objectid, u64 hint, |
| u64 empty_size) |
| { |
| u64 ref_generation; |
| |
| if (root->ref_cows) |
| ref_generation = trans->transid; |
| else |
| ref_generation = 0; |
| |
| |
| return __btrfs_alloc_free_block(trans, root, blocksize, root_objectid, |
| ref_generation, 0, 0, hint, empty_size); |
| } |
| |
| /* |
| * helper function to allocate a block for a given tree |
| * returns the tree buffer or NULL. |
| */ |
| struct extent_buffer *__btrfs_alloc_free_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| u32 blocksize, |
| u64 root_objectid, |
| u64 ref_generation, |
| u64 first_objectid, |
| int level, |
| u64 hint, |
| u64 empty_size) |
| { |
| struct btrfs_key ins; |
| int ret; |
| struct extent_buffer *buf; |
| |
| ret = btrfs_alloc_extent(trans, root, blocksize, |
| root_objectid, ref_generation, |
| level, first_objectid, empty_size, hint, |
| (u64)-1, &ins, 0); |
| if (ret) { |
| BUG_ON(ret > 0); |
| return ERR_PTR(ret); |
| } |
| buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize); |
| if (!buf) { |
| btrfs_free_extent(trans, root, ins.objectid, blocksize, |
| root->root_key.objectid, ref_generation, |
| 0, 0, 0); |
| return ERR_PTR(-ENOMEM); |
| } |
| btrfs_set_header_generation(buf, trans->transid); |
| clean_tree_block(trans, root, buf); |
| wait_on_tree_block_writeback(root, buf); |
| btrfs_set_buffer_uptodate(buf); |
| |
| if (PageDirty(buf->first_page)) { |
| printk("page %lu dirty\n", buf->first_page->index); |
| WARN_ON(1); |
| } |
| |
| set_extent_dirty(&trans->transaction->dirty_pages, buf->start, |
| buf->start + buf->len - 1, GFP_NOFS); |
| set_extent_bits(&BTRFS_I(root->fs_info->btree_inode)->io_tree, |
| buf->start, buf->start + buf->len - 1, |
| EXTENT_CSUM, GFP_NOFS); |
| buf->flags |= EXTENT_CSUM; |
| if (!btrfs_test_opt(root, SSD)) |
| btrfs_set_buffer_defrag(buf); |
| trans->blocks_used++; |
| return buf; |
| } |
| |
| static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| { |
| u64 leaf_owner; |
| u64 leaf_generation; |
| struct btrfs_key key; |
| struct btrfs_file_extent_item *fi; |
| int i; |
| int nritems; |
| int ret; |
| |
| BUG_ON(!btrfs_is_leaf(leaf)); |
| nritems = btrfs_header_nritems(leaf); |
| leaf_owner = btrfs_header_owner(leaf); |
| leaf_generation = btrfs_header_generation(leaf); |
| |
| for (i = 0; i < nritems; i++) { |
| u64 disk_bytenr; |
| |
| btrfs_item_key_to_cpu(leaf, &key, i); |
| if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) |
| continue; |
| fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); |
| if (btrfs_file_extent_type(leaf, fi) == |
| BTRFS_FILE_EXTENT_INLINE) |
| continue; |
| /* |
| * FIXME make sure to insert a trans record that |
| * repeats the snapshot del on crash |
| */ |
| disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); |
| if (disk_bytenr == 0) |
| continue; |
| ret = btrfs_free_extent(trans, root, disk_bytenr, |
| btrfs_file_extent_disk_num_bytes(leaf, fi), |
| leaf_owner, leaf_generation, |
| key.objectid, key.offset, 0); |
| BUG_ON(ret); |
| } |
| return 0; |
| } |
| |
| static void noinline reada_walk_down(struct btrfs_root *root, |
| struct extent_buffer *node, |
| int slot) |
| { |
| u64 bytenr; |
| u64 last = 0; |
| u32 nritems; |
| u32 refs; |
| u32 blocksize; |
| int ret; |
| int i; |
| int level; |
| int skipped = 0; |
| |
| nritems = btrfs_header_nritems(node); |
| level = btrfs_header_level(node); |
| if (level) |
| return; |
| |
| for (i = slot; i < nritems && skipped < 32; i++) { |
| bytenr = btrfs_node_blockptr(node, i); |
| if (last && ((bytenr > last && bytenr - last > 32 * 1024) || |
| (last > bytenr && last - bytenr > 32 * 1024))) { |
| skipped++; |
| continue; |
| } |
| blocksize = btrfs_level_size(root, level - 1); |
| if (i != slot) { |
| ret = lookup_extent_ref(NULL, root, bytenr, |
| blocksize, &refs); |
| BUG_ON(ret); |
| if (refs != 1) { |
| skipped++; |
| continue; |
| } |
| } |
| mutex_unlock(&root->fs_info->fs_mutex); |
| ret = readahead_tree_block(root, bytenr, blocksize); |
| last = bytenr + blocksize; |
| cond_resched(); |
| mutex_lock(&root->fs_info->fs_mutex); |
| if (ret) |
| break; |
| } |
| } |
| |
| /* |
| * helper function for drop_snapshot, this walks down the tree dropping ref |
| * counts as it goes. |
| */ |
| static int noinline walk_down_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int *level) |
| { |
| u64 root_owner; |
| u64 root_gen; |
| u64 bytenr; |
| struct extent_buffer *next; |
| struct extent_buffer *cur; |
| struct extent_buffer *parent; |
| u32 blocksize; |
| int ret; |
| u32 refs; |
| |
| WARN_ON(*level < 0); |
| WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| ret = lookup_extent_ref(trans, root, |
| path->nodes[*level]->start, |
| path->nodes[*level]->len, &refs); |
| BUG_ON(ret); |
| if (refs > 1) |
| goto out; |
| |
| /* |
| * walk down to the last node level and free all the leaves |
| */ |
| while(*level >= 0) { |
| WARN_ON(*level < 0); |
| WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| cur = path->nodes[*level]; |
| |
| if (btrfs_header_level(cur) != *level) |
| WARN_ON(1); |
| |
| if (path->slots[*level] >= |
| btrfs_header_nritems(cur)) |
| break; |
| if (*level == 0) { |
| ret = drop_leaf_ref(trans, root, cur); |
| BUG_ON(ret); |
| break; |
| } |
| bytenr = btrfs_node_blockptr(cur, path->slots[*level]); |
| blocksize = btrfs_level_size(root, *level - 1); |
| ret = lookup_extent_ref(trans, root, bytenr, blocksize, &refs); |
| BUG_ON(ret); |
| if (refs != 1) { |
| parent = path->nodes[*level]; |
| root_owner = btrfs_header_owner(parent); |
| root_gen = btrfs_header_generation(parent); |
| path->slots[*level]++; |
| ret = btrfs_free_extent(trans, root, bytenr, |
| blocksize, root_owner, |
| root_gen, 0, 0, 1); |
| BUG_ON(ret); |
| continue; |
| } |
| next = btrfs_find_tree_block(root, bytenr, blocksize); |
| if (!next || !btrfs_buffer_uptodate(next)) { |
| free_extent_buffer(next); |
| reada_walk_down(root, cur, path->slots[*level]); |
| mutex_unlock(&root->fs_info->fs_mutex); |
| next = read_tree_block(root, bytenr, blocksize); |
| mutex_lock(&root->fs_info->fs_mutex); |
| |
| /* we dropped the lock, check one more time */ |
| ret = lookup_extent_ref(trans, root, bytenr, |
| blocksize, &refs); |
| BUG_ON(ret); |
| if (refs != 1) { |
| parent = path->nodes[*level]; |
| root_owner = btrfs_header_owner(parent); |
| root_gen = btrfs_header_generation(parent); |
| |
| path->slots[*level]++; |
| free_extent_buffer(next); |
| ret = btrfs_free_extent(trans, root, bytenr, |
| blocksize, |
| root_owner, |
| root_gen, 0, 0, 1); |
| BUG_ON(ret); |
| continue; |
| } |
| } |
| WARN_ON(*level <= 0); |
| if (path->nodes[*level-1]) |
| free_extent_buffer(path->nodes[*level-1]); |
| path->nodes[*level-1] = next; |
| *level = btrfs_header_level(next); |
| path->slots[*level] = 0; |
| } |
| out: |
| WARN_ON(*level < 0); |
| WARN_ON(*level >= BTRFS_MAX_LEVEL); |
| |
| if (path->nodes[*level] == root->node) { |
| root_owner = root->root_key.objectid; |
| parent = path->nodes[*level]; |
| } else { |
| parent = path->nodes[*level + 1]; |
| root_owner = btrfs_header_owner(parent); |
| } |
| |
| root_gen = btrfs_header_generation(parent); |
| ret = btrfs_free_extent(trans, root, path->nodes[*level]->start, |
| path->nodes[*level]->len, |
| root_owner, root_gen, 0, 0, 1); |
| free_extent_buffer(path->nodes[*level]); |
| path->nodes[*level] = NULL; |
| *level += 1; |
| BUG_ON(ret); |
| return 0; |
| } |
| |
| /* |
| * helper for dropping snapshots. This walks back up the tree in the path |
| * to find the first node higher up where we haven't yet gone through |
| * all the slots |
| */ |
| static int noinline walk_up_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int *level) |
| { |
| u64 root_owner; |
| u64 root_gen; |
| struct btrfs_root_item *root_item = &root->root_item; |
| int i; |
| int slot; |
| int ret; |
| |
| for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { |
| slot = path->slots[i]; |
| if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { |
| struct extent_buffer *node; |
| struct btrfs_disk_key disk_key; |
| node = path->nodes[i]; |
| path->slots[i]++; |
| *level = i; |
| WARN_ON(*level == 0); |
| btrfs_node_key(node, &disk_key, path->slots[i]); |
| memcpy(&root_item->drop_progress, |
| &disk_key, sizeof(disk_key)); |
| root_item->drop_level = i; |
| return 0; |
| } else { |
| if (path->nodes[*level] == root->node) { |
| root_owner = root->root_key.objectid; |
| root_gen = |
| btrfs_header_generation(path->nodes[*level]); |
| } else { |
| struct extent_buffer *node; |
| node = path->nodes[*level + 1]; |
| root_owner = btrfs_header_owner(node); |
| root_gen = btrfs_header_generation(node); |
| } |
| ret = btrfs_free_extent(trans, root, |
| path->nodes[*level]->start, |
| path->nodes[*level]->len, |
| root_owner, root_gen, 0, 0, 1); |
| BUG_ON(ret); |
| free_extent_buffer(path->nodes[*level]); |
| path->nodes[*level] = NULL; |
| *level = i + 1; |
| } |
| } |
| return 1; |
| } |
| |
| /* |
| * drop the reference count on the tree rooted at 'snap'. This traverses |
| * the tree freeing any blocks that have a ref count of zero after being |
| * decremented. |
| */ |
| int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root) |
| { |
| int ret = 0; |
| int wret; |
| int level; |
| struct btrfs_path *path; |
| int i; |
| int orig_level; |
| struct btrfs_root_item *root_item = &root->root_item; |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| |
| level = btrfs_header_level(root->node); |
| orig_level = level; |
| if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { |
| path->nodes[level] = root->node; |
| extent_buffer_get(root->node); |
| path->slots[level] = 0; |
| } else { |
| struct btrfs_key key; |
| struct btrfs_disk_key found_key; |
| struct extent_buffer *node; |
| |
| btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); |
| level = root_item->drop_level; |
| path->lowest_level = level; |
| wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (wret < 0) { |
| ret = wret; |
| goto out; |
| } |
| node = path->nodes[level]; |
| btrfs_node_key(node, &found_key, path->slots[level]); |
| WARN_ON(memcmp(&found_key, &root_item->drop_progress, |
| sizeof(found_key))); |
| } |
| while(1) { |
| wret = walk_down_tree(trans, root, path, &level); |
| if (wret > 0) |
| break; |
| if (wret < 0) |
| ret = wret; |
| |
| wret = walk_up_tree(trans, root, path, &level); |
| if (wret > 0) |
| break; |
| if (wret < 0) |
| ret = wret; |
| ret = -EAGAIN; |
| break; |
| } |
| for (i = 0; i <= orig_level; i++) { |
| if (path->nodes[i]) { |
| free_extent_buffer(path->nodes[i]); |
| path->nodes[i] = NULL; |
| } |
| } |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_free_block_groups(struct btrfs_fs_info *info) |
| { |
| u64 start; |
| u64 end; |
| u64 ptr; |
| int ret; |
| while(1) { |
| ret = find_first_extent_bit(&info->block_group_cache, 0, |
| &start, &end, (unsigned int)-1); |
| if (ret) |
| break; |
| ret = get_state_private(&info->block_group_cache, start, &ptr); |
| if (!ret) |
| kfree((void *)(unsigned long)ptr); |
| clear_extent_bits(&info->block_group_cache, start, |
| end, (unsigned int)-1, GFP_NOFS); |
| } |
| while(1) { |
| ret = find_first_extent_bit(&info->free_space_cache, 0, |
| &start, &end, EXTENT_DIRTY); |
| if (ret) |
| break; |
| clear_extent_dirty(&info->free_space_cache, start, |
| end, GFP_NOFS); |
| } |
| return 0; |
| } |
| |
| static int noinline relocate_inode_pages(struct inode *inode, u64 start, |
| u64 len) |
| { |
| u64 page_start; |
| u64 page_end; |
| u64 delalloc_start; |
| u64 existing_delalloc; |
| unsigned long last_index; |
| unsigned long i; |
| struct page *page; |
| struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; |
| struct file_ra_state *ra; |
| |
| ra = kzalloc(sizeof(*ra), GFP_NOFS); |
| |
| mutex_lock(&inode->i_mutex); |
| i = start >> PAGE_CACHE_SHIFT; |
| last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; |
| |
| file_ra_state_init(ra, inode->i_mapping); |
| btrfs_force_ra(inode->i_mapping, ra, NULL, i, last_index); |
| kfree(ra); |
| |
| for (; i <= last_index; i++) { |
| page = grab_cache_page(inode->i_mapping, i); |
| if (!page) |
| goto out_unlock; |
| if (!PageUptodate(page)) { |
| btrfs_readpage(NULL, page); |
| lock_page(page); |
| if (!PageUptodate(page)) { |
| unlock_page(page); |
| page_cache_release(page); |
| goto out_unlock; |
| } |
| } |
| page_start = (u64)page->index << PAGE_CACHE_SHIFT; |
| page_end = page_start + PAGE_CACHE_SIZE - 1; |
| |
| lock_extent(io_tree, page_start, page_end, GFP_NOFS); |
| |
| delalloc_start = page_start; |
| existing_delalloc = count_range_bits(io_tree, |
| &delalloc_start, page_end, |
| PAGE_CACHE_SIZE, EXTENT_DELALLOC); |
| |
| set_extent_delalloc(io_tree, page_start, |
| page_end, GFP_NOFS); |
| |
| unlock_extent(io_tree, page_start, page_end, GFP_NOFS); |
| set_page_dirty(page); |
| unlock_page(page); |
| page_cache_release(page); |
| } |
| |
| out_unlock: |
| mutex_unlock(&inode->i_mutex); |
| return 0; |
| } |
| |
| /* |
| * note, this releases the path |
| */ |
| static int noinline relocate_one_reference(struct btrfs_root *extent_root, |
| struct btrfs_path *path, |
| struct btrfs_key *extent_key) |
| { |
| struct inode *inode; |
| struct btrfs_root *found_root; |
| struct btrfs_key *root_location; |
| struct btrfs_extent_ref *ref; |
| u64 ref_root; |
| u64 ref_gen; |
| u64 ref_objectid; |
| u64 ref_offset; |
| int ret; |
| |
| ref = btrfs_item_ptr(path->nodes[0], path->slots[0], |
| struct btrfs_extent_ref); |
| ref_root = btrfs_ref_root(path->nodes[0], ref); |
| ref_gen = btrfs_ref_generation(path->nodes[0], ref); |
| ref_objectid = btrfs_ref_objectid(path->nodes[0], ref); |
| ref_offset = btrfs_ref_offset(path->nodes[0], ref); |
| btrfs_release_path(extent_root, path); |
| |
| root_location = kmalloc(sizeof(*root_location), GFP_NOFS); |
| root_location->objectid = ref_root; |
| if (ref_gen == 0) |
| root_location->offset = 0; |
| else |
| root_location->offset = (u64)-1; |
| root_location->type = BTRFS_ROOT_ITEM_KEY; |
| |
| found_root = btrfs_read_fs_root_no_name(extent_root->fs_info, |
| root_location); |
| BUG_ON(!found_root); |
| kfree(root_location); |
| |
| if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) { |
| mutex_unlock(&extent_root->fs_info->fs_mutex); |
| inode = btrfs_iget_locked(extent_root->fs_info->sb, |
| ref_objectid, found_root); |
| if (inode->i_state & I_NEW) { |
| /* the inode and parent dir are two different roots */ |
| BTRFS_I(inode)->root = found_root; |
| BTRFS_I(inode)->location.objectid = ref_objectid; |
| BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; |
| BTRFS_I(inode)->location.offset = 0; |
| btrfs_read_locked_inode(inode); |
| unlock_new_inode(inode); |
| |
| } |
| /* this can happen if the reference is not against |
| * the latest version of the tree root |
| */ |
| if (is_bad_inode(inode)) { |
| mutex_lock(&extent_root->fs_info->fs_mutex); |
| goto out; |
| } |
| relocate_inode_pages(inode, ref_offset, extent_key->offset); |
| /* FIXME, data=ordered will help get rid of this */ |
| filemap_fdatawrite(inode->i_mapping); |
| iput(inode); |
| mutex_lock(&extent_root->fs_info->fs_mutex); |
| } else { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_key found_key; |
| struct extent_buffer *eb; |
| int level; |
| int i; |
| |
| trans = btrfs_start_transaction(found_root, 1); |
| eb = read_tree_block(found_root, extent_key->objectid, |
| extent_key->offset); |
| level = btrfs_header_level(eb); |
| |
| if (level == 0) |
| btrfs_item_key_to_cpu(eb, &found_key, 0); |
| else |
| btrfs_node_key_to_cpu(eb, &found_key, 0); |
| |
| free_extent_buffer(eb); |
| |
| path->lowest_level = level; |
| path->reada = 2; |
| ret = btrfs_search_slot(trans, found_root, &found_key, path, |
| 0, 1); |
| path->lowest_level = 0; |
| for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
| if (!path->nodes[i]) |
| break; |
| free_extent_buffer(path->nodes[i]); |
| path->nodes[i] = NULL; |
| } |
| btrfs_release_path(found_root, path); |
| btrfs_end_transaction(trans, found_root); |
| } |
| |
| out: |
| return 0; |
| } |
| |
| static int noinline relocate_one_extent(struct btrfs_root *extent_root, |
| struct btrfs_path *path, |
| struct btrfs_key *extent_key) |
| { |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| u32 item_size; |
| int ret = 0; |
| |
| key.objectid = extent_key->objectid; |
| key.type = BTRFS_EXTENT_REF_KEY; |
| key.offset = 0; |
| |
| while(1) { |
| ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); |
| |
| if (ret < 0) |
| goto out; |
| |
| ret = 0; |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| if (path->slots[0] == nritems) |
| goto out; |
| |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid != extent_key->objectid) |
| break; |
| |
| if (found_key.type != BTRFS_EXTENT_REF_KEY) |
| break; |
| |
| key.offset = found_key.offset + 1; |
| item_size = btrfs_item_size_nr(leaf, path->slots[0]); |
| |
| ret = relocate_one_reference(extent_root, path, extent_key); |
| if (ret) |
| goto out; |
| } |
| ret = 0; |
| out: |
| btrfs_release_path(extent_root, path); |
| return ret; |
| } |
| |
| int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 new_size) |
| { |
| struct btrfs_trans_handle *trans; |
| struct btrfs_root *tree_root = root->fs_info->tree_root; |
| struct btrfs_path *path; |
| u64 cur_byte; |
| u64 total_found; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct extent_io_tree *block_group_cache; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| int ret; |
| int progress = 0; |
| |
| btrfs_set_super_total_bytes(&info->super_copy, new_size); |
| clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1, |
| GFP_NOFS); |
| block_group_cache = &info->block_group_cache; |
| path = btrfs_alloc_path(); |
| root = root->fs_info->extent_root; |
| path->reada = 2; |
| |
| again: |
| total_found = 0; |
| key.objectid = new_size; |
| key.offset = 0; |
| key.type = 0; |
| cur_byte = key.objectid; |
| |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); |
| if (ret < 0) |
| goto out; |
| if (ret == 0) { |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.objectid + found_key.offset > new_size) { |
| cur_byte = found_key.objectid; |
| key.objectid = cur_byte; |
| } |
| } |
| btrfs_release_path(root, path); |
| |
| while(1) { |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| next: |
| if (path->slots[0] >= nritems) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| goto out; |
| if (ret == 1) { |
| ret = 0; |
| break; |
| } |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| |
| if (progress && need_resched()) { |
| memcpy(&key, &found_key, sizeof(key)); |
| mutex_unlock(&root->fs_info->fs_mutex); |
| cond_resched(); |
| mutex_lock(&root->fs_info->fs_mutex); |
| btrfs_release_path(root, path); |
| btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| progress = 0; |
| goto next; |
| } |
| progress = 1; |
| |
| if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY || |
| found_key.objectid + found_key.offset <= cur_byte) { |
| path->slots[0]++; |
| goto next; |
| } |
| |
| total_found++; |
| cur_byte = found_key.objectid + found_key.offset; |
| key.objectid = cur_byte; |
| btrfs_release_path(root, path); |
| ret = relocate_one_extent(root, path, &found_key); |
| } |
| |
| btrfs_release_path(root, path); |
| |
| if (total_found > 0) { |
| trans = btrfs_start_transaction(tree_root, 1); |
| btrfs_commit_transaction(trans, tree_root); |
| |
| mutex_unlock(&root->fs_info->fs_mutex); |
| btrfs_clean_old_snapshots(tree_root); |
| mutex_lock(&root->fs_info->fs_mutex); |
| |
| trans = btrfs_start_transaction(tree_root, 1); |
| btrfs_commit_transaction(trans, tree_root); |
| goto again; |
| } |
| |
| trans = btrfs_start_transaction(root, 1); |
| key.objectid = new_size; |
| key.offset = 0; |
| key.type = 0; |
| while(1) { |
| u64 ptr; |
| |
| ret = btrfs_search_slot(trans, root, &key, path, -1, 1); |
| if (ret < 0) |
| goto out; |
| |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| bg_next: |
| if (path->slots[0] >= nritems) { |
| ret = btrfs_next_leaf(root, path); |
| if (ret < 0) |
| break; |
| if (ret == 1) { |
| ret = 0; |
| break; |
| } |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| |
| /* |
| * btrfs_next_leaf doesn't cow buffers, we have to |
| * do the search again |
| */ |
| memcpy(&key, &found_key, sizeof(key)); |
| btrfs_release_path(root, path); |
| goto resched_check; |
| } |
| |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (btrfs_key_type(&found_key) != BTRFS_BLOCK_GROUP_ITEM_KEY) { |
| printk("shrinker found key %Lu %u %Lu\n", |
| found_key.objectid, found_key.type, |
| found_key.offset); |
| path->slots[0]++; |
| goto bg_next; |
| } |
| ret = get_state_private(&info->block_group_cache, |
| found_key.objectid, &ptr); |
| if (!ret) |
| kfree((void *)(unsigned long)ptr); |
| |
| clear_extent_bits(&info->block_group_cache, found_key.objectid, |
| found_key.objectid + found_key.offset - 1, |
| (unsigned int)-1, GFP_NOFS); |
| |
| key.objectid = found_key.objectid + 1; |
| btrfs_del_item(trans, root, path); |
| btrfs_release_path(root, path); |
| resched_check: |
| if (need_resched()) { |
| mutex_unlock(&root->fs_info->fs_mutex); |
| cond_resched(); |
| mutex_lock(&root->fs_info->fs_mutex); |
| } |
| } |
| clear_extent_dirty(&info->free_space_cache, new_size, (u64)-1, |
| GFP_NOFS); |
| btrfs_commit_transaction(trans, root); |
| out: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_grow_extent_tree(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 new_size) |
| { |
| btrfs_set_super_total_bytes(&root->fs_info->super_copy, new_size); |
| return 0; |
| } |
| |
| int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, |
| struct btrfs_key *key) |
| { |
| int ret; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| int slot; |
| |
| ret = btrfs_search_slot(NULL, root, key, path, 0, 0); |
| if (ret < 0) |
| return ret; |
| 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 error; |
| break; |
| } |
| btrfs_item_key_to_cpu(leaf, &found_key, slot); |
| |
| if (found_key.objectid >= key->objectid && |
| found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) |
| return 0; |
| path->slots[0]++; |
| } |
| ret = -ENOENT; |
| error: |
| return ret; |
| } |
| |
| 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; |
| |
| found = __find_space_info(info, flags); |
| if (found) { |
| found->total_bytes += total_bytes; |
| found->bytes_used += bytes_used; |
| WARN_ON(found->total_bytes < found->bytes_used); |
| *space_info = found; |
| return 0; |
| } |
| found = kmalloc(sizeof(*found), GFP_NOFS); |
| if (!found) |
| return -ENOMEM; |
| |
| list_add(&found->list, &info->space_info); |
| found->flags = flags; |
| found->total_bytes = total_bytes; |
| found->bytes_used = bytes_used; |
| found->bytes_pinned = 0; |
| found->full = 0; |
| *space_info = found; |
| return 0; |
| } |
| |
| int btrfs_read_block_groups(struct btrfs_root *root) |
| { |
| struct btrfs_path *path; |
| int ret; |
| int bit; |
| struct btrfs_block_group_cache *cache; |
| struct btrfs_fs_info *info = root->fs_info; |
| struct btrfs_space_info *space_info; |
| struct extent_io_tree *block_group_cache; |
| struct btrfs_key key; |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| |
| block_group_cache = &info->block_group_cache; |
| root = info->extent_root; |
| key.objectid = 0; |
| key.offset = 0; |
| btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); |
| path = btrfs_alloc_path(); |
| if (!path) |
| return -ENOMEM; |
| |
| while(1) { |
| ret = find_first_block_group(root, path, &key); |
| if (ret > 0) { |
| ret = 0; |
| goto error; |
| } |
| if (ret != 0) |
| goto error; |
| |
| leaf = path->nodes[0]; |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| cache = kmalloc(sizeof(*cache), GFP_NOFS); |
| if (!cache) { |
| ret = -ENOMEM; |
| break; |
| } |
| |
| read_extent_buffer(leaf, &cache->item, |
| btrfs_item_ptr_offset(leaf, path->slots[0]), |
| sizeof(cache->item)); |
| memcpy(&cache->key, &found_key, sizeof(found_key)); |
| cache->cached = 0; |
| cache->pinned = 0; |
| |
| key.objectid = found_key.objectid + found_key.offset; |
| btrfs_release_path(root, path); |
| cache->flags = btrfs_block_group_flags(&cache->item); |
| bit = 0; |
| if (cache->flags & BTRFS_BLOCK_GROUP_DATA) { |
| bit = BLOCK_GROUP_DATA; |
| } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { |
| bit = BLOCK_GROUP_SYSTEM; |
| } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) { |
| bit = BLOCK_GROUP_METADATA; |
| } |
| |
| ret = update_space_info(info, cache->flags, found_key.offset, |
| btrfs_block_group_used(&cache->item), |
| &space_info); |
| BUG_ON(ret); |
| cache->space_info = space_info; |
| |
| /* use EXTENT_LOCKED to prevent merging */ |
| set_extent_bits(block_group_cache, found_key.objectid, |
| found_key.objectid + found_key.offset - 1, |
| bit | EXTENT_LOCKED, GFP_NOFS); |
| set_state_private(block_group_cache, found_key.objectid, |
| (unsigned long)cache); |
| |
| if (key.objectid >= |
| btrfs_super_total_bytes(&info->super_copy)) |
| break; |
| } |
| ret = 0; |
| error: |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| int btrfs_make_block_group(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, u64 bytes_used, |
| u64 type, u64 chunk_tree, u64 chunk_objectid, |
| u64 size) |
| { |
| int ret; |
| int bit = 0; |
| struct btrfs_root *extent_root; |
| struct btrfs_block_group_cache *cache; |
| struct extent_io_tree *block_group_cache; |
| |
| extent_root = root->fs_info->extent_root; |
| block_group_cache = &root->fs_info->block_group_cache; |
| |
| cache = kmalloc(sizeof(*cache), GFP_NOFS); |
| BUG_ON(!cache); |
| cache->key.objectid = chunk_objectid; |
| cache->key.offset = size; |
| cache->cached = 0; |
| cache->pinned = 0; |
| btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); |
| memset(&cache->item, 0, sizeof(cache->item)); |
| btrfs_set_block_group_used(&cache->item, bytes_used); |
| btrfs_set_block_group_chunk_tree(&cache->item, chunk_tree); |
| btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); |
| cache->flags = type; |
| btrfs_set_block_group_flags(&cache->item, type); |
| |
| ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, |
| &cache->space_info); |
| BUG_ON(ret); |
| |
| if (type & BTRFS_BLOCK_GROUP_DATA) { |
| bit = BLOCK_GROUP_DATA; |
| } else if (type & BTRFS_BLOCK_GROUP_SYSTEM) { |
| bit = BLOCK_GROUP_SYSTEM; |
| } else if (type & BTRFS_BLOCK_GROUP_METADATA) { |
| bit = BLOCK_GROUP_METADATA; |
| } |
| set_extent_bits(block_group_cache, chunk_objectid, |
| chunk_objectid + size - 1, |
| bit | EXTENT_LOCKED, GFP_NOFS); |
| set_state_private(block_group_cache, chunk_objectid, |
| (unsigned long)cache); |
| |
| ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, |
| sizeof(cache->item)); |
| BUG_ON(ret); |
| |
| finish_current_insert(trans, extent_root); |
| ret = del_pending_extents(trans, extent_root); |
| BUG_ON(ret); |
| return 0; |
| } |