| /* |
| * 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 "ctree.h" |
| #include "disk-io.h" |
| #include "transaction.h" |
| #include "print-tree.h" |
| #include "locking.h" |
| |
| static int split_node(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int level); |
| static int split_leaf(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *ins_key, |
| struct btrfs_path *path, int data_size, int extend); |
| static int push_node_left(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *dst, |
| struct extent_buffer *src, int empty); |
| static int balance_node_right(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *dst_buf, |
| struct extent_buffer *src_buf); |
| static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct btrfs_path *path, int level, int slot); |
| |
| inline void btrfs_init_path(struct btrfs_path *p) |
| { |
| memset(p, 0, sizeof(*p)); |
| } |
| |
| struct btrfs_path *btrfs_alloc_path(void) |
| { |
| struct btrfs_path *path; |
| path = kmem_cache_alloc(btrfs_path_cachep, GFP_NOFS); |
| if (path) { |
| btrfs_init_path(path); |
| path->reada = 1; |
| } |
| return path; |
| } |
| |
| void btrfs_free_path(struct btrfs_path *p) |
| { |
| btrfs_release_path(NULL, p); |
| kmem_cache_free(btrfs_path_cachep, p); |
| } |
| |
| void noinline btrfs_release_path(struct btrfs_root *root, struct btrfs_path *p) |
| { |
| int i; |
| |
| for (i = 0; i < BTRFS_MAX_LEVEL; i++) { |
| p->slots[i] = 0; |
| if (!p->nodes[i]) |
| continue; |
| if (p->locks[i]) { |
| btrfs_tree_unlock(p->nodes[i]); |
| p->locks[i] = 0; |
| } |
| free_extent_buffer(p->nodes[i]); |
| p->nodes[i] = NULL; |
| } |
| } |
| |
| struct extent_buffer *btrfs_root_node(struct btrfs_root *root) |
| { |
| struct extent_buffer *eb; |
| spin_lock(&root->node_lock); |
| eb = root->node; |
| extent_buffer_get(eb); |
| spin_unlock(&root->node_lock); |
| return eb; |
| } |
| |
| struct extent_buffer *btrfs_lock_root_node(struct btrfs_root *root) |
| { |
| struct extent_buffer *eb; |
| |
| while(1) { |
| eb = btrfs_root_node(root); |
| btrfs_tree_lock(eb); |
| |
| spin_lock(&root->node_lock); |
| if (eb == root->node) { |
| spin_unlock(&root->node_lock); |
| break; |
| } |
| spin_unlock(&root->node_lock); |
| |
| btrfs_tree_unlock(eb); |
| free_extent_buffer(eb); |
| } |
| return eb; |
| } |
| |
| static void add_root_to_dirty_list(struct btrfs_root *root) |
| { |
| if (root->track_dirty && list_empty(&root->dirty_list)) { |
| list_add(&root->dirty_list, |
| &root->fs_info->dirty_cowonly_roots); |
| } |
| } |
| |
| int btrfs_copy_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| struct extent_buffer **cow_ret, u64 new_root_objectid) |
| { |
| struct extent_buffer *cow; |
| u32 nritems; |
| int ret = 0; |
| int level; |
| struct btrfs_key first_key; |
| struct btrfs_root *new_root; |
| |
| new_root = kmalloc(sizeof(*new_root), GFP_NOFS); |
| if (!new_root) |
| return -ENOMEM; |
| |
| memcpy(new_root, root, sizeof(*new_root)); |
| new_root->root_key.objectid = new_root_objectid; |
| |
| WARN_ON(root->ref_cows && trans->transid != |
| root->fs_info->running_transaction->transid); |
| WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
| |
| level = btrfs_header_level(buf); |
| nritems = btrfs_header_nritems(buf); |
| if (nritems) { |
| if (level == 0) |
| btrfs_item_key_to_cpu(buf, &first_key, 0); |
| else |
| btrfs_node_key_to_cpu(buf, &first_key, 0); |
| } else { |
| first_key.objectid = 0; |
| } |
| cow = btrfs_alloc_free_block(trans, new_root, buf->len, |
| new_root_objectid, |
| trans->transid, first_key.objectid, |
| level, buf->start, 0); |
| if (IS_ERR(cow)) { |
| kfree(new_root); |
| return PTR_ERR(cow); |
| } |
| |
| copy_extent_buffer(cow, buf, 0, 0, cow->len); |
| btrfs_set_header_bytenr(cow, cow->start); |
| btrfs_set_header_generation(cow, trans->transid); |
| btrfs_set_header_owner(cow, new_root_objectid); |
| btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN); |
| |
| WARN_ON(btrfs_header_generation(buf) > trans->transid); |
| ret = btrfs_inc_ref(trans, new_root, buf, 0); |
| kfree(new_root); |
| |
| if (ret) |
| return ret; |
| |
| btrfs_mark_buffer_dirty(cow); |
| *cow_ret = cow; |
| return 0; |
| } |
| |
| int noinline __btrfs_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *buf, |
| struct extent_buffer *parent, int parent_slot, |
| struct extent_buffer **cow_ret, |
| u64 search_start, u64 empty_size, |
| u64 prealloc_dest) |
| { |
| u64 root_gen; |
| struct extent_buffer *cow; |
| u32 nritems; |
| int ret = 0; |
| int different_trans = 0; |
| int level; |
| int unlock_orig = 0; |
| struct btrfs_key first_key; |
| |
| if (*cow_ret == buf) |
| unlock_orig = 1; |
| |
| WARN_ON(!btrfs_tree_locked(buf)); |
| |
| if (root->ref_cows) { |
| root_gen = trans->transid; |
| } else { |
| root_gen = 0; |
| } |
| WARN_ON(root->ref_cows && trans->transid != |
| root->fs_info->running_transaction->transid); |
| WARN_ON(root->ref_cows && trans->transid != root->last_trans); |
| |
| level = btrfs_header_level(buf); |
| nritems = btrfs_header_nritems(buf); |
| if (nritems) { |
| if (level == 0) |
| btrfs_item_key_to_cpu(buf, &first_key, 0); |
| else |
| btrfs_node_key_to_cpu(buf, &first_key, 0); |
| } else { |
| first_key.objectid = 0; |
| } |
| if (prealloc_dest) { |
| struct btrfs_key ins; |
| |
| ins.objectid = prealloc_dest; |
| ins.offset = buf->len; |
| ins.type = BTRFS_EXTENT_ITEM_KEY; |
| |
| ret = btrfs_alloc_reserved_extent(trans, root, |
| root->root_key.objectid, |
| root_gen, level, |
| first_key.objectid, |
| &ins); |
| BUG_ON(ret); |
| cow = btrfs_init_new_buffer(trans, root, prealloc_dest, |
| buf->len); |
| } else { |
| cow = btrfs_alloc_free_block(trans, root, buf->len, |
| root->root_key.objectid, |
| root_gen, first_key.objectid, |
| level, search_start, empty_size); |
| } |
| if (IS_ERR(cow)) |
| return PTR_ERR(cow); |
| |
| copy_extent_buffer(cow, buf, 0, 0, cow->len); |
| btrfs_set_header_bytenr(cow, cow->start); |
| btrfs_set_header_generation(cow, trans->transid); |
| btrfs_set_header_owner(cow, root->root_key.objectid); |
| btrfs_clear_header_flag(cow, BTRFS_HEADER_FLAG_WRITTEN); |
| |
| WARN_ON(btrfs_header_generation(buf) > trans->transid); |
| if (btrfs_header_generation(buf) != trans->transid) { |
| different_trans = 1; |
| ret = btrfs_inc_ref(trans, root, buf, 1); |
| if (ret) |
| return ret; |
| } else { |
| clean_tree_block(trans, root, buf); |
| } |
| |
| if (buf == root->node) { |
| WARN_ON(parent && parent != buf); |
| root_gen = btrfs_header_generation(buf); |
| |
| spin_lock(&root->node_lock); |
| root->node = cow; |
| extent_buffer_get(cow); |
| spin_unlock(&root->node_lock); |
| |
| if (buf != root->commit_root) { |
| btrfs_free_extent(trans, root, buf->start, |
| buf->len, root->root_key.objectid, |
| root_gen, 0, 0, 1); |
| } |
| free_extent_buffer(buf); |
| add_root_to_dirty_list(root); |
| } else { |
| root_gen = btrfs_header_generation(parent); |
| btrfs_set_node_blockptr(parent, parent_slot, |
| cow->start); |
| WARN_ON(trans->transid == 0); |
| btrfs_set_node_ptr_generation(parent, parent_slot, |
| trans->transid); |
| btrfs_mark_buffer_dirty(parent); |
| WARN_ON(btrfs_header_generation(parent) != trans->transid); |
| btrfs_free_extent(trans, root, buf->start, buf->len, |
| btrfs_header_owner(parent), root_gen, |
| 0, 0, 1); |
| } |
| if (unlock_orig) |
| btrfs_tree_unlock(buf); |
| free_extent_buffer(buf); |
| btrfs_mark_buffer_dirty(cow); |
| *cow_ret = cow; |
| return 0; |
| } |
| |
| int noinline btrfs_cow_block(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *buf, |
| struct extent_buffer *parent, int parent_slot, |
| struct extent_buffer **cow_ret, u64 prealloc_dest) |
| { |
| u64 search_start; |
| u64 header_trans; |
| int ret; |
| |
| if (trans->transaction != root->fs_info->running_transaction) { |
| printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, |
| root->fs_info->running_transaction->transid); |
| WARN_ON(1); |
| } |
| if (trans->transid != root->fs_info->generation) { |
| printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, |
| root->fs_info->generation); |
| WARN_ON(1); |
| } |
| |
| header_trans = btrfs_header_generation(buf); |
| spin_lock(&root->fs_info->hash_lock); |
| if (header_trans == trans->transid && |
| !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { |
| *cow_ret = buf; |
| spin_unlock(&root->fs_info->hash_lock); |
| WARN_ON(prealloc_dest); |
| return 0; |
| } |
| spin_unlock(&root->fs_info->hash_lock); |
| search_start = buf->start & ~((u64)(1024 * 1024 * 1024) - 1); |
| ret = __btrfs_cow_block(trans, root, buf, parent, |
| parent_slot, cow_ret, search_start, 0, |
| prealloc_dest); |
| return ret; |
| } |
| |
| static int close_blocks(u64 blocknr, u64 other, u32 blocksize) |
| { |
| if (blocknr < other && other - (blocknr + blocksize) < 32768) |
| return 1; |
| if (blocknr > other && blocknr - (other + blocksize) < 32768) |
| return 1; |
| return 0; |
| } |
| |
| /* |
| * compare two keys in a memcmp fashion |
| */ |
| static int comp_keys(struct btrfs_disk_key *disk, struct btrfs_key *k2) |
| { |
| struct btrfs_key k1; |
| |
| btrfs_disk_key_to_cpu(&k1, disk); |
| |
| if (k1.objectid > k2->objectid) |
| return 1; |
| if (k1.objectid < k2->objectid) |
| return -1; |
| if (k1.type > k2->type) |
| return 1; |
| if (k1.type < k2->type) |
| return -1; |
| if (k1.offset > k2->offset) |
| return 1; |
| if (k1.offset < k2->offset) |
| return -1; |
| return 0; |
| } |
| |
| |
| int btrfs_realloc_node(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *parent, |
| int start_slot, int cache_only, u64 *last_ret, |
| struct btrfs_key *progress) |
| { |
| struct extent_buffer *cur; |
| u64 blocknr; |
| u64 gen; |
| u64 search_start = *last_ret; |
| u64 last_block = 0; |
| u64 other; |
| u32 parent_nritems; |
| int end_slot; |
| int i; |
| int err = 0; |
| int parent_level; |
| int uptodate; |
| u32 blocksize; |
| int progress_passed = 0; |
| struct btrfs_disk_key disk_key; |
| |
| parent_level = btrfs_header_level(parent); |
| if (cache_only && parent_level != 1) |
| return 0; |
| |
| if (trans->transaction != root->fs_info->running_transaction) { |
| printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, |
| root->fs_info->running_transaction->transid); |
| WARN_ON(1); |
| } |
| if (trans->transid != root->fs_info->generation) { |
| printk(KERN_CRIT "trans %Lu running %Lu\n", trans->transid, |
| root->fs_info->generation); |
| WARN_ON(1); |
| } |
| |
| parent_nritems = btrfs_header_nritems(parent); |
| blocksize = btrfs_level_size(root, parent_level - 1); |
| end_slot = parent_nritems; |
| |
| if (parent_nritems == 1) |
| return 0; |
| |
| for (i = start_slot; i < end_slot; i++) { |
| int close = 1; |
| |
| if (!parent->map_token) { |
| map_extent_buffer(parent, |
| btrfs_node_key_ptr_offset(i), |
| sizeof(struct btrfs_key_ptr), |
| &parent->map_token, &parent->kaddr, |
| &parent->map_start, &parent->map_len, |
| KM_USER1); |
| } |
| btrfs_node_key(parent, &disk_key, i); |
| if (!progress_passed && comp_keys(&disk_key, progress) < 0) |
| continue; |
| |
| progress_passed = 1; |
| blocknr = btrfs_node_blockptr(parent, i); |
| gen = btrfs_node_ptr_generation(parent, i); |
| if (last_block == 0) |
| last_block = blocknr; |
| |
| if (i > 0) { |
| other = btrfs_node_blockptr(parent, i - 1); |
| close = close_blocks(blocknr, other, blocksize); |
| } |
| if (!close && i < end_slot - 2) { |
| other = btrfs_node_blockptr(parent, i + 1); |
| close = close_blocks(blocknr, other, blocksize); |
| } |
| if (close) { |
| last_block = blocknr; |
| continue; |
| } |
| if (parent->map_token) { |
| unmap_extent_buffer(parent, parent->map_token, |
| KM_USER1); |
| parent->map_token = NULL; |
| } |
| |
| cur = btrfs_find_tree_block(root, blocknr, blocksize); |
| if (cur) |
| uptodate = btrfs_buffer_uptodate(cur, gen); |
| else |
| uptodate = 0; |
| if (!cur || !uptodate) { |
| if (cache_only) { |
| free_extent_buffer(cur); |
| continue; |
| } |
| if (!cur) { |
| cur = read_tree_block(root, blocknr, |
| blocksize, gen); |
| } else if (!uptodate) { |
| btrfs_read_buffer(cur, gen); |
| } |
| } |
| if (search_start == 0) |
| search_start = last_block; |
| |
| btrfs_tree_lock(cur); |
| err = __btrfs_cow_block(trans, root, cur, parent, i, |
| &cur, search_start, |
| min(16 * blocksize, |
| (end_slot - i) * blocksize), 0); |
| if (err) { |
| btrfs_tree_unlock(cur); |
| free_extent_buffer(cur); |
| break; |
| } |
| search_start = cur->start; |
| last_block = cur->start; |
| *last_ret = search_start; |
| btrfs_tree_unlock(cur); |
| free_extent_buffer(cur); |
| } |
| if (parent->map_token) { |
| unmap_extent_buffer(parent, parent->map_token, |
| KM_USER1); |
| parent->map_token = NULL; |
| } |
| return err; |
| } |
| |
| /* |
| * The leaf data grows from end-to-front in the node. |
| * this returns the address of the start of the last item, |
| * which is the stop of the leaf data stack |
| */ |
| static inline unsigned int leaf_data_end(struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| { |
| u32 nr = btrfs_header_nritems(leaf); |
| if (nr == 0) |
| return BTRFS_LEAF_DATA_SIZE(root); |
| return btrfs_item_offset_nr(leaf, nr - 1); |
| } |
| |
| static int check_node(struct btrfs_root *root, struct btrfs_path *path, |
| int level) |
| { |
| struct extent_buffer *parent = NULL; |
| struct extent_buffer *node = path->nodes[level]; |
| struct btrfs_disk_key parent_key; |
| struct btrfs_disk_key node_key; |
| int parent_slot; |
| int slot; |
| struct btrfs_key cpukey; |
| u32 nritems = btrfs_header_nritems(node); |
| |
| if (path->nodes[level + 1]) |
| parent = path->nodes[level + 1]; |
| |
| slot = path->slots[level]; |
| BUG_ON(nritems == 0); |
| if (parent) { |
| parent_slot = path->slots[level + 1]; |
| btrfs_node_key(parent, &parent_key, parent_slot); |
| btrfs_node_key(node, &node_key, 0); |
| BUG_ON(memcmp(&parent_key, &node_key, |
| sizeof(struct btrfs_disk_key))); |
| BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
| btrfs_header_bytenr(node)); |
| } |
| BUG_ON(nritems > BTRFS_NODEPTRS_PER_BLOCK(root)); |
| if (slot != 0) { |
| btrfs_node_key_to_cpu(node, &cpukey, slot - 1); |
| btrfs_node_key(node, &node_key, slot); |
| BUG_ON(comp_keys(&node_key, &cpukey) <= 0); |
| } |
| if (slot < nritems - 1) { |
| btrfs_node_key_to_cpu(node, &cpukey, slot + 1); |
| btrfs_node_key(node, &node_key, slot); |
| BUG_ON(comp_keys(&node_key, &cpukey) >= 0); |
| } |
| return 0; |
| } |
| |
| static int check_leaf(struct btrfs_root *root, struct btrfs_path *path, |
| int level) |
| { |
| struct extent_buffer *leaf = path->nodes[level]; |
| struct extent_buffer *parent = NULL; |
| int parent_slot; |
| struct btrfs_key cpukey; |
| struct btrfs_disk_key parent_key; |
| struct btrfs_disk_key leaf_key; |
| int slot = path->slots[0]; |
| |
| u32 nritems = btrfs_header_nritems(leaf); |
| |
| if (path->nodes[level + 1]) |
| parent = path->nodes[level + 1]; |
| |
| if (nritems == 0) |
| return 0; |
| |
| if (parent) { |
| parent_slot = path->slots[level + 1]; |
| btrfs_node_key(parent, &parent_key, parent_slot); |
| btrfs_item_key(leaf, &leaf_key, 0); |
| |
| BUG_ON(memcmp(&parent_key, &leaf_key, |
| sizeof(struct btrfs_disk_key))); |
| BUG_ON(btrfs_node_blockptr(parent, parent_slot) != |
| btrfs_header_bytenr(leaf)); |
| } |
| #if 0 |
| for (i = 0; nritems > 1 && i < nritems - 2; i++) { |
| btrfs_item_key_to_cpu(leaf, &cpukey, i + 1); |
| btrfs_item_key(leaf, &leaf_key, i); |
| if (comp_keys(&leaf_key, &cpukey) >= 0) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d offset bad key\n", i); |
| BUG_ON(1); |
| } |
| if (btrfs_item_offset_nr(leaf, i) != |
| btrfs_item_end_nr(leaf, i + 1)) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d offset bad\n", i); |
| BUG_ON(1); |
| } |
| if (i == 0) { |
| if (btrfs_item_offset_nr(leaf, i) + |
| btrfs_item_size_nr(leaf, i) != |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d first offset bad\n", i); |
| BUG_ON(1); |
| } |
| } |
| } |
| if (nritems > 0) { |
| if (btrfs_item_size_nr(leaf, nritems - 1) > 4096) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d bad size \n", nritems - 1); |
| BUG_ON(1); |
| } |
| } |
| #endif |
| if (slot != 0 && slot < nritems - 1) { |
| btrfs_item_key(leaf, &leaf_key, slot); |
| btrfs_item_key_to_cpu(leaf, &cpukey, slot - 1); |
| if (comp_keys(&leaf_key, &cpukey) <= 0) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d offset bad key\n", slot); |
| BUG_ON(1); |
| } |
| if (btrfs_item_offset_nr(leaf, slot - 1) != |
| btrfs_item_end_nr(leaf, slot)) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d offset bad\n", slot); |
| BUG_ON(1); |
| } |
| } |
| if (slot < nritems - 1) { |
| btrfs_item_key(leaf, &leaf_key, slot); |
| btrfs_item_key_to_cpu(leaf, &cpukey, slot + 1); |
| BUG_ON(comp_keys(&leaf_key, &cpukey) >= 0); |
| if (btrfs_item_offset_nr(leaf, slot) != |
| btrfs_item_end_nr(leaf, slot + 1)) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d offset bad\n", slot); |
| BUG_ON(1); |
| } |
| } |
| BUG_ON(btrfs_item_offset_nr(leaf, 0) + |
| btrfs_item_size_nr(leaf, 0) != BTRFS_LEAF_DATA_SIZE(root)); |
| return 0; |
| } |
| |
| static int noinline check_block(struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| u64 found_start; |
| return 0; |
| if (btrfs_header_level(path->nodes[level]) != level) |
| printk("warning: bad level %Lu wanted %d found %d\n", |
| path->nodes[level]->start, level, |
| btrfs_header_level(path->nodes[level])); |
| found_start = btrfs_header_bytenr(path->nodes[level]); |
| if (found_start != path->nodes[level]->start) { |
| printk("warning: bad bytentr %Lu found %Lu\n", |
| path->nodes[level]->start, found_start); |
| } |
| #if 0 |
| struct extent_buffer *buf = path->nodes[level]; |
| |
| if (memcmp_extent_buffer(buf, root->fs_info->fsid, |
| (unsigned long)btrfs_header_fsid(buf), |
| BTRFS_FSID_SIZE)) { |
| printk("warning bad block %Lu\n", buf->start); |
| return 1; |
| } |
| #endif |
| if (level == 0) |
| return check_leaf(root, path, level); |
| return check_node(root, path, level); |
| } |
| |
| /* |
| * search for key in the extent_buffer. The items start at offset p, |
| * and they are item_size apart. There are 'max' items in p. |
| * |
| * the slot in the array is returned via slot, and it points to |
| * the place where you would insert key if it is not found in |
| * the array. |
| * |
| * slot may point to max if the key is bigger than all of the keys |
| */ |
| static noinline int generic_bin_search(struct extent_buffer *eb, |
| unsigned long p, |
| int item_size, struct btrfs_key *key, |
| int max, int *slot) |
| { |
| int low = 0; |
| int high = max; |
| int mid; |
| int ret; |
| struct btrfs_disk_key *tmp = NULL; |
| struct btrfs_disk_key unaligned; |
| unsigned long offset; |
| char *map_token = NULL; |
| char *kaddr = NULL; |
| unsigned long map_start = 0; |
| unsigned long map_len = 0; |
| int err; |
| |
| while(low < high) { |
| mid = (low + high) / 2; |
| offset = p + mid * item_size; |
| |
| if (!map_token || offset < map_start || |
| (offset + sizeof(struct btrfs_disk_key)) > |
| map_start + map_len) { |
| if (map_token) { |
| unmap_extent_buffer(eb, map_token, KM_USER0); |
| map_token = NULL; |
| } |
| err = map_extent_buffer(eb, offset, |
| sizeof(struct btrfs_disk_key), |
| &map_token, &kaddr, |
| &map_start, &map_len, KM_USER0); |
| |
| if (!err) { |
| tmp = (struct btrfs_disk_key *)(kaddr + offset - |
| map_start); |
| } else { |
| read_extent_buffer(eb, &unaligned, |
| offset, sizeof(unaligned)); |
| tmp = &unaligned; |
| } |
| |
| } else { |
| tmp = (struct btrfs_disk_key *)(kaddr + offset - |
| map_start); |
| } |
| ret = comp_keys(tmp, key); |
| |
| if (ret < 0) |
| low = mid + 1; |
| else if (ret > 0) |
| high = mid; |
| else { |
| *slot = mid; |
| if (map_token) |
| unmap_extent_buffer(eb, map_token, KM_USER0); |
| return 0; |
| } |
| } |
| *slot = low; |
| if (map_token) |
| unmap_extent_buffer(eb, map_token, KM_USER0); |
| return 1; |
| } |
| |
| /* |
| * simple bin_search frontend that does the right thing for |
| * leaves vs nodes |
| */ |
| static int bin_search(struct extent_buffer *eb, struct btrfs_key *key, |
| int level, int *slot) |
| { |
| if (level == 0) { |
| return generic_bin_search(eb, |
| offsetof(struct btrfs_leaf, items), |
| sizeof(struct btrfs_item), |
| key, btrfs_header_nritems(eb), |
| slot); |
| } else { |
| return generic_bin_search(eb, |
| offsetof(struct btrfs_node, ptrs), |
| sizeof(struct btrfs_key_ptr), |
| key, btrfs_header_nritems(eb), |
| slot); |
| } |
| return -1; |
| } |
| |
| static noinline struct extent_buffer *read_node_slot(struct btrfs_root *root, |
| struct extent_buffer *parent, int slot) |
| { |
| int level = btrfs_header_level(parent); |
| if (slot < 0) |
| return NULL; |
| if (slot >= btrfs_header_nritems(parent)) |
| return NULL; |
| |
| BUG_ON(level == 0); |
| |
| return read_tree_block(root, btrfs_node_blockptr(parent, slot), |
| btrfs_level_size(root, level - 1), |
| btrfs_node_ptr_generation(parent, slot)); |
| } |
| |
| static noinline int balance_level(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| struct extent_buffer *right = NULL; |
| struct extent_buffer *mid; |
| struct extent_buffer *left = NULL; |
| struct extent_buffer *parent = NULL; |
| int ret = 0; |
| int wret; |
| int pslot; |
| int orig_slot = path->slots[level]; |
| int err_on_enospc = 0; |
| u64 orig_ptr; |
| |
| if (level == 0) |
| return 0; |
| |
| mid = path->nodes[level]; |
| WARN_ON(!path->locks[level]); |
| WARN_ON(btrfs_header_generation(mid) != trans->transid); |
| |
| orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
| |
| if (level < BTRFS_MAX_LEVEL - 1) |
| parent = path->nodes[level + 1]; |
| pslot = path->slots[level + 1]; |
| |
| /* |
| * deal with the case where there is only one pointer in the root |
| * by promoting the node below to a root |
| */ |
| if (!parent) { |
| struct extent_buffer *child; |
| |
| if (btrfs_header_nritems(mid) != 1) |
| return 0; |
| |
| /* promote the child to a root */ |
| child = read_node_slot(root, mid, 0); |
| btrfs_tree_lock(child); |
| BUG_ON(!child); |
| ret = btrfs_cow_block(trans, root, child, mid, 0, &child, 0); |
| BUG_ON(ret); |
| |
| spin_lock(&root->node_lock); |
| root->node = child; |
| spin_unlock(&root->node_lock); |
| |
| add_root_to_dirty_list(root); |
| btrfs_tree_unlock(child); |
| path->locks[level] = 0; |
| path->nodes[level] = NULL; |
| clean_tree_block(trans, root, mid); |
| btrfs_tree_unlock(mid); |
| /* once for the path */ |
| free_extent_buffer(mid); |
| ret = btrfs_free_extent(trans, root, mid->start, mid->len, |
| root->root_key.objectid, |
| btrfs_header_generation(mid), 0, 0, 1); |
| /* once for the root ptr */ |
| free_extent_buffer(mid); |
| return ret; |
| } |
| if (btrfs_header_nritems(mid) > |
| BTRFS_NODEPTRS_PER_BLOCK(root) / 4) |
| return 0; |
| |
| if (btrfs_header_nritems(mid) < 2) |
| err_on_enospc = 1; |
| |
| left = read_node_slot(root, parent, pslot - 1); |
| if (left) { |
| btrfs_tree_lock(left); |
| wret = btrfs_cow_block(trans, root, left, |
| parent, pslot - 1, &left, 0); |
| if (wret) { |
| ret = wret; |
| goto enospc; |
| } |
| } |
| right = read_node_slot(root, parent, pslot + 1); |
| if (right) { |
| btrfs_tree_lock(right); |
| wret = btrfs_cow_block(trans, root, right, |
| parent, pslot + 1, &right, 0); |
| if (wret) { |
| ret = wret; |
| goto enospc; |
| } |
| } |
| |
| /* first, try to make some room in the middle buffer */ |
| if (left) { |
| orig_slot += btrfs_header_nritems(left); |
| wret = push_node_left(trans, root, left, mid, 1); |
| if (wret < 0) |
| ret = wret; |
| if (btrfs_header_nritems(mid) < 2) |
| err_on_enospc = 1; |
| } |
| |
| /* |
| * then try to empty the right most buffer into the middle |
| */ |
| if (right) { |
| wret = push_node_left(trans, root, mid, right, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| if (btrfs_header_nritems(right) == 0) { |
| u64 bytenr = right->start; |
| u64 generation = btrfs_header_generation(parent); |
| u32 blocksize = right->len; |
| |
| clean_tree_block(trans, root, right); |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| right = NULL; |
| wret = del_ptr(trans, root, path, level + 1, pslot + |
| 1); |
| if (wret) |
| ret = wret; |
| wret = btrfs_free_extent(trans, root, bytenr, |
| blocksize, |
| btrfs_header_owner(parent), |
| generation, 0, 0, 1); |
| if (wret) |
| ret = wret; |
| } else { |
| struct btrfs_disk_key right_key; |
| btrfs_node_key(right, &right_key, 0); |
| btrfs_set_node_key(parent, &right_key, pslot + 1); |
| btrfs_mark_buffer_dirty(parent); |
| } |
| } |
| if (btrfs_header_nritems(mid) == 1) { |
| /* |
| * we're not allowed to leave a node with one item in the |
| * tree during a delete. A deletion from lower in the tree |
| * could try to delete the only pointer in this node. |
| * So, pull some keys from the left. |
| * There has to be a left pointer at this point because |
| * otherwise we would have pulled some pointers from the |
| * right |
| */ |
| BUG_ON(!left); |
| wret = balance_node_right(trans, root, mid, left); |
| if (wret < 0) { |
| ret = wret; |
| goto enospc; |
| } |
| if (wret == 1) { |
| wret = push_node_left(trans, root, left, mid, 1); |
| if (wret < 0) |
| ret = wret; |
| } |
| BUG_ON(wret == 1); |
| } |
| if (btrfs_header_nritems(mid) == 0) { |
| /* we've managed to empty the middle node, drop it */ |
| u64 root_gen = btrfs_header_generation(parent); |
| u64 bytenr = mid->start; |
| u32 blocksize = mid->len; |
| |
| clean_tree_block(trans, root, mid); |
| btrfs_tree_unlock(mid); |
| free_extent_buffer(mid); |
| mid = NULL; |
| wret = del_ptr(trans, root, path, level + 1, pslot); |
| if (wret) |
| ret = wret; |
| wret = btrfs_free_extent(trans, root, bytenr, blocksize, |
| btrfs_header_owner(parent), |
| root_gen, 0, 0, 1); |
| if (wret) |
| ret = wret; |
| } else { |
| /* update the parent key to reflect our changes */ |
| struct btrfs_disk_key mid_key; |
| btrfs_node_key(mid, &mid_key, 0); |
| btrfs_set_node_key(parent, &mid_key, pslot); |
| btrfs_mark_buffer_dirty(parent); |
| } |
| |
| /* update the path */ |
| if (left) { |
| if (btrfs_header_nritems(left) > orig_slot) { |
| extent_buffer_get(left); |
| /* left was locked after cow */ |
| path->nodes[level] = left; |
| path->slots[level + 1] -= 1; |
| path->slots[level] = orig_slot; |
| if (mid) { |
| btrfs_tree_unlock(mid); |
| free_extent_buffer(mid); |
| } |
| } else { |
| orig_slot -= btrfs_header_nritems(left); |
| path->slots[level] = orig_slot; |
| } |
| } |
| /* double check we haven't messed things up */ |
| check_block(root, path, level); |
| if (orig_ptr != |
| btrfs_node_blockptr(path->nodes[level], path->slots[level])) |
| BUG(); |
| enospc: |
| if (right) { |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| } |
| if (left) { |
| if (path->nodes[level] != left) |
| btrfs_tree_unlock(left); |
| free_extent_buffer(left); |
| } |
| return ret; |
| } |
| |
| /* returns zero if the push worked, non-zero otherwise */ |
| static int noinline push_nodes_for_insert(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| struct extent_buffer *right = NULL; |
| struct extent_buffer *mid; |
| struct extent_buffer *left = NULL; |
| struct extent_buffer *parent = NULL; |
| int ret = 0; |
| int wret; |
| int pslot; |
| int orig_slot = path->slots[level]; |
| u64 orig_ptr; |
| |
| if (level == 0) |
| return 1; |
| |
| mid = path->nodes[level]; |
| WARN_ON(btrfs_header_generation(mid) != trans->transid); |
| orig_ptr = btrfs_node_blockptr(mid, orig_slot); |
| |
| if (level < BTRFS_MAX_LEVEL - 1) |
| parent = path->nodes[level + 1]; |
| pslot = path->slots[level + 1]; |
| |
| if (!parent) |
| return 1; |
| |
| left = read_node_slot(root, parent, pslot - 1); |
| |
| /* first, try to make some room in the middle buffer */ |
| if (left) { |
| u32 left_nr; |
| |
| btrfs_tree_lock(left); |
| left_nr = btrfs_header_nritems(left); |
| if (left_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
| wret = 1; |
| } else { |
| ret = btrfs_cow_block(trans, root, left, parent, |
| pslot - 1, &left, 0); |
| if (ret) |
| wret = 1; |
| else { |
| wret = push_node_left(trans, root, |
| left, mid, 0); |
| } |
| } |
| if (wret < 0) |
| ret = wret; |
| if (wret == 0) { |
| struct btrfs_disk_key disk_key; |
| orig_slot += left_nr; |
| btrfs_node_key(mid, &disk_key, 0); |
| btrfs_set_node_key(parent, &disk_key, pslot); |
| btrfs_mark_buffer_dirty(parent); |
| if (btrfs_header_nritems(left) > orig_slot) { |
| path->nodes[level] = left; |
| path->slots[level + 1] -= 1; |
| path->slots[level] = orig_slot; |
| btrfs_tree_unlock(mid); |
| free_extent_buffer(mid); |
| } else { |
| orig_slot -= |
| btrfs_header_nritems(left); |
| path->slots[level] = orig_slot; |
| btrfs_tree_unlock(left); |
| free_extent_buffer(left); |
| } |
| return 0; |
| } |
| btrfs_tree_unlock(left); |
| free_extent_buffer(left); |
| } |
| right = read_node_slot(root, parent, pslot + 1); |
| |
| /* |
| * then try to empty the right most buffer into the middle |
| */ |
| if (right) { |
| u32 right_nr; |
| btrfs_tree_lock(right); |
| right_nr = btrfs_header_nritems(right); |
| if (right_nr >= BTRFS_NODEPTRS_PER_BLOCK(root) - 1) { |
| wret = 1; |
| } else { |
| ret = btrfs_cow_block(trans, root, right, |
| parent, pslot + 1, |
| &right, 0); |
| if (ret) |
| wret = 1; |
| else { |
| wret = balance_node_right(trans, root, |
| right, mid); |
| } |
| } |
| if (wret < 0) |
| ret = wret; |
| if (wret == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_node_key(right, &disk_key, 0); |
| btrfs_set_node_key(parent, &disk_key, pslot + 1); |
| btrfs_mark_buffer_dirty(parent); |
| |
| if (btrfs_header_nritems(mid) <= orig_slot) { |
| path->nodes[level] = right; |
| path->slots[level + 1] += 1; |
| path->slots[level] = orig_slot - |
| btrfs_header_nritems(mid); |
| btrfs_tree_unlock(mid); |
| free_extent_buffer(mid); |
| } else { |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| } |
| return 0; |
| } |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| } |
| return 1; |
| } |
| |
| /* |
| * readahead one full node of leaves |
| */ |
| static noinline void reada_for_search(struct btrfs_root *root, |
| struct btrfs_path *path, |
| int level, int slot, u64 objectid) |
| { |
| struct extent_buffer *node; |
| struct btrfs_disk_key disk_key; |
| u32 nritems; |
| u64 search; |
| u64 lowest_read; |
| u64 highest_read; |
| u64 nread = 0; |
| int direction = path->reada; |
| struct extent_buffer *eb; |
| u32 nr; |
| u32 blocksize; |
| u32 nscan = 0; |
| |
| if (level != 1) |
| return; |
| |
| if (!path->nodes[level]) |
| return; |
| |
| node = path->nodes[level]; |
| |
| search = btrfs_node_blockptr(node, slot); |
| blocksize = btrfs_level_size(root, level - 1); |
| eb = btrfs_find_tree_block(root, search, blocksize); |
| if (eb) { |
| free_extent_buffer(eb); |
| return; |
| } |
| |
| highest_read = search; |
| lowest_read = search; |
| |
| nritems = btrfs_header_nritems(node); |
| nr = slot; |
| while(1) { |
| if (direction < 0) { |
| if (nr == 0) |
| break; |
| nr--; |
| } else if (direction > 0) { |
| nr++; |
| if (nr >= nritems) |
| break; |
| } |
| if (path->reada < 0 && objectid) { |
| btrfs_node_key(node, &disk_key, nr); |
| if (btrfs_disk_key_objectid(&disk_key) != objectid) |
| break; |
| } |
| search = btrfs_node_blockptr(node, nr); |
| if ((search >= lowest_read && search <= highest_read) || |
| (search < lowest_read && lowest_read - search <= 32768) || |
| (search > highest_read && search - highest_read <= 32768)) { |
| readahead_tree_block(root, search, blocksize, |
| btrfs_node_ptr_generation(node, nr)); |
| nread += blocksize; |
| } |
| nscan++; |
| if (path->reada < 2 && (nread > (256 * 1024) || nscan > 32)) |
| break; |
| if(nread > (1024 * 1024) || nscan > 128) |
| break; |
| |
| if (search < lowest_read) |
| lowest_read = search; |
| if (search > highest_read) |
| highest_read = search; |
| } |
| } |
| |
| static noinline void unlock_up(struct btrfs_path *path, int level, |
| int lowest_unlock) |
| { |
| int i; |
| int skip_level = level; |
| int no_skips = 0; |
| struct extent_buffer *t; |
| |
| for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
| if (!path->nodes[i]) |
| break; |
| if (!path->locks[i]) |
| break; |
| if (!no_skips && path->slots[i] == 0) { |
| skip_level = i + 1; |
| continue; |
| } |
| if (!no_skips && path->keep_locks) { |
| u32 nritems; |
| t = path->nodes[i]; |
| nritems = btrfs_header_nritems(t); |
| if (nritems < 1 || path->slots[i] >= nritems - 1) { |
| skip_level = i + 1; |
| continue; |
| } |
| } |
| if (skip_level < i && i >= lowest_unlock) |
| no_skips = 1; |
| |
| t = path->nodes[i]; |
| if (i >= lowest_unlock && i > skip_level && path->locks[i]) { |
| btrfs_tree_unlock(t); |
| path->locks[i] = 0; |
| } |
| } |
| } |
| |
| /* |
| * look for key in the tree. path is filled in with nodes along the way |
| * if key is found, we return zero and you can find the item in the leaf |
| * level of the path (level 0) |
| * |
| * If the key isn't found, the path points to the slot where it should |
| * be inserted, and 1 is returned. If there are other errors during the |
| * search a negative error number is returned. |
| * |
| * if ins_len > 0, nodes and leaves will be split as we walk down the |
| * tree. if ins_len < 0, nodes will be merged as we walk down the tree (if |
| * possible) |
| */ |
| int btrfs_search_slot(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *key, struct btrfs_path *p, int |
| ins_len, int cow) |
| { |
| struct extent_buffer *b; |
| struct extent_buffer *tmp; |
| int slot; |
| int ret; |
| int level; |
| int should_reada = p->reada; |
| int lowest_unlock = 1; |
| int blocksize; |
| u8 lowest_level = 0; |
| u64 blocknr; |
| u64 gen; |
| struct btrfs_key prealloc_block; |
| |
| lowest_level = p->lowest_level; |
| WARN_ON(lowest_level && ins_len); |
| WARN_ON(p->nodes[0] != NULL); |
| WARN_ON(cow && root == root->fs_info->extent_root && |
| !mutex_is_locked(&root->fs_info->alloc_mutex)); |
| if (ins_len < 0) |
| lowest_unlock = 2; |
| |
| prealloc_block.objectid = 0; |
| |
| again: |
| if (p->skip_locking) |
| b = btrfs_root_node(root); |
| else |
| b = btrfs_lock_root_node(root); |
| |
| while (b) { |
| level = btrfs_header_level(b); |
| |
| /* |
| * setup the path here so we can release it under lock |
| * contention with the cow code |
| */ |
| p->nodes[level] = b; |
| if (!p->skip_locking) |
| p->locks[level] = 1; |
| |
| if (cow) { |
| int wret; |
| |
| /* is a cow on this block not required */ |
| spin_lock(&root->fs_info->hash_lock); |
| if (btrfs_header_generation(b) == trans->transid && |
| !btrfs_header_flag(b, BTRFS_HEADER_FLAG_WRITTEN)) { |
| spin_unlock(&root->fs_info->hash_lock); |
| goto cow_done; |
| } |
| spin_unlock(&root->fs_info->hash_lock); |
| |
| /* ok, we have to cow, is our old prealloc the right |
| * size? |
| */ |
| if (prealloc_block.objectid && |
| prealloc_block.offset != b->len) { |
| btrfs_free_reserved_extent(root, |
| prealloc_block.objectid, |
| prealloc_block.offset); |
| prealloc_block.objectid = 0; |
| } |
| |
| /* |
| * for higher level blocks, try not to allocate blocks |
| * with the block and the parent locks held. |
| */ |
| if (level > 1 && !prealloc_block.objectid && |
| btrfs_path_lock_waiting(p, level)) { |
| u32 size = b->len; |
| u64 hint = b->start; |
| |
| btrfs_release_path(root, p); |
| ret = btrfs_reserve_extent(trans, root, |
| size, size, 0, |
| hint, (u64)-1, |
| &prealloc_block, 0); |
| BUG_ON(ret); |
| goto again; |
| } |
| |
| wret = btrfs_cow_block(trans, root, b, |
| p->nodes[level + 1], |
| p->slots[level + 1], |
| &b, prealloc_block.objectid); |
| prealloc_block.objectid = 0; |
| if (wret) { |
| free_extent_buffer(b); |
| ret = wret; |
| goto done; |
| } |
| } |
| cow_done: |
| BUG_ON(!cow && ins_len); |
| if (level != btrfs_header_level(b)) |
| WARN_ON(1); |
| level = btrfs_header_level(b); |
| |
| p->nodes[level] = b; |
| if (!p->skip_locking) |
| p->locks[level] = 1; |
| |
| ret = check_block(root, p, level); |
| if (ret) { |
| ret = -1; |
| goto done; |
| } |
| |
| ret = bin_search(b, key, level, &slot); |
| if (level != 0) { |
| if (ret && slot > 0) |
| slot -= 1; |
| p->slots[level] = slot; |
| if (ins_len > 0 && btrfs_header_nritems(b) >= |
| BTRFS_NODEPTRS_PER_BLOCK(root) - 3) { |
| int sret = split_node(trans, root, p, level); |
| BUG_ON(sret > 0); |
| if (sret) { |
| ret = sret; |
| goto done; |
| } |
| b = p->nodes[level]; |
| slot = p->slots[level]; |
| } else if (ins_len < 0) { |
| int sret = balance_level(trans, root, p, |
| level); |
| if (sret) { |
| ret = sret; |
| goto done; |
| } |
| b = p->nodes[level]; |
| if (!b) { |
| btrfs_release_path(NULL, p); |
| goto again; |
| } |
| slot = p->slots[level]; |
| BUG_ON(btrfs_header_nritems(b) == 1); |
| } |
| unlock_up(p, level, lowest_unlock); |
| |
| /* this is only true while dropping a snapshot */ |
| if (level == lowest_level) { |
| break; |
| } |
| |
| blocknr = btrfs_node_blockptr(b, slot); |
| gen = btrfs_node_ptr_generation(b, slot); |
| blocksize = btrfs_level_size(root, level - 1); |
| |
| tmp = btrfs_find_tree_block(root, blocknr, blocksize); |
| if (tmp && btrfs_buffer_uptodate(tmp, gen)) { |
| b = tmp; |
| } else { |
| /* |
| * reduce lock contention at high levels |
| * of the btree by dropping locks before |
| * we read. |
| */ |
| if (level > 1) { |
| btrfs_release_path(NULL, p); |
| if (tmp) |
| free_extent_buffer(tmp); |
| if (should_reada) |
| reada_for_search(root, p, |
| level, slot, |
| key->objectid); |
| |
| tmp = read_tree_block(root, blocknr, |
| blocksize, gen); |
| if (tmp) |
| free_extent_buffer(tmp); |
| goto again; |
| } else { |
| if (tmp) |
| free_extent_buffer(tmp); |
| if (should_reada) |
| reada_for_search(root, p, |
| level, slot, |
| key->objectid); |
| b = read_node_slot(root, b, slot); |
| } |
| } |
| if (!p->skip_locking) |
| btrfs_tree_lock(b); |
| } else { |
| p->slots[level] = slot; |
| if (ins_len > 0 && btrfs_leaf_free_space(root, b) < |
| sizeof(struct btrfs_item) + ins_len) { |
| int sret = split_leaf(trans, root, key, |
| p, ins_len, ret == 0); |
| BUG_ON(sret > 0); |
| if (sret) { |
| ret = sret; |
| goto done; |
| } |
| } |
| unlock_up(p, level, lowest_unlock); |
| goto done; |
| } |
| } |
| ret = 1; |
| done: |
| if (prealloc_block.objectid) { |
| btrfs_free_reserved_extent(root, |
| prealloc_block.objectid, |
| prealloc_block.offset); |
| } |
| |
| return ret; |
| } |
| |
| /* |
| * adjust the pointers going up the tree, starting at level |
| * making sure the right key of each node is points to 'key'. |
| * This is used after shifting pointers to the left, so it stops |
| * fixing up pointers when a given leaf/node is not in slot 0 of the |
| * higher levels |
| * |
| * If this fails to write a tree block, it returns -1, but continues |
| * fixing up the blocks in ram so the tree is consistent. |
| */ |
| static int fixup_low_keys(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct btrfs_path *path, |
| struct btrfs_disk_key *key, int level) |
| { |
| int i; |
| int ret = 0; |
| struct extent_buffer *t; |
| |
| for (i = level; i < BTRFS_MAX_LEVEL; i++) { |
| int tslot = path->slots[i]; |
| if (!path->nodes[i]) |
| break; |
| t = path->nodes[i]; |
| btrfs_set_node_key(t, key, tslot); |
| btrfs_mark_buffer_dirty(path->nodes[i]); |
| if (tslot != 0) |
| break; |
| } |
| return ret; |
| } |
| |
| /* |
| * try to push data from one node into the next node left in the |
| * tree. |
| * |
| * returns 0 if some ptrs were pushed left, < 0 if there was some horrible |
| * error, and > 0 if there was no room in the left hand block. |
| */ |
| static int push_node_left(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct extent_buffer *dst, |
| struct extent_buffer *src, int empty) |
| { |
| int push_items = 0; |
| int src_nritems; |
| int dst_nritems; |
| int ret = 0; |
| |
| src_nritems = btrfs_header_nritems(src); |
| dst_nritems = btrfs_header_nritems(dst); |
| push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
| WARN_ON(btrfs_header_generation(src) != trans->transid); |
| WARN_ON(btrfs_header_generation(dst) != trans->transid); |
| |
| if (!empty && src_nritems <= 8) |
| return 1; |
| |
| if (push_items <= 0) { |
| return 1; |
| } |
| |
| if (empty) { |
| push_items = min(src_nritems, push_items); |
| if (push_items < src_nritems) { |
| /* leave at least 8 pointers in the node if |
| * we aren't going to empty it |
| */ |
| if (src_nritems - push_items < 8) { |
| if (push_items <= 8) |
| return 1; |
| push_items -= 8; |
| } |
| } |
| } else |
| push_items = min(src_nritems - 8, push_items); |
| |
| copy_extent_buffer(dst, src, |
| btrfs_node_key_ptr_offset(dst_nritems), |
| btrfs_node_key_ptr_offset(0), |
| push_items * sizeof(struct btrfs_key_ptr)); |
| |
| if (push_items < src_nritems) { |
| memmove_extent_buffer(src, btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(push_items), |
| (src_nritems - push_items) * |
| sizeof(struct btrfs_key_ptr)); |
| } |
| btrfs_set_header_nritems(src, src_nritems - push_items); |
| btrfs_set_header_nritems(dst, dst_nritems + push_items); |
| btrfs_mark_buffer_dirty(src); |
| btrfs_mark_buffer_dirty(dst); |
| return ret; |
| } |
| |
| /* |
| * try to push data from one node into the next node right in the |
| * tree. |
| * |
| * returns 0 if some ptrs were pushed, < 0 if there was some horrible |
| * error, and > 0 if there was no room in the right hand block. |
| * |
| * this will only push up to 1/2 the contents of the left node over |
| */ |
| static int balance_node_right(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct extent_buffer *dst, |
| struct extent_buffer *src) |
| { |
| int push_items = 0; |
| int max_push; |
| int src_nritems; |
| int dst_nritems; |
| int ret = 0; |
| |
| WARN_ON(btrfs_header_generation(src) != trans->transid); |
| WARN_ON(btrfs_header_generation(dst) != trans->transid); |
| |
| src_nritems = btrfs_header_nritems(src); |
| dst_nritems = btrfs_header_nritems(dst); |
| push_items = BTRFS_NODEPTRS_PER_BLOCK(root) - dst_nritems; |
| if (push_items <= 0) { |
| return 1; |
| } |
| |
| if (src_nritems < 4) { |
| return 1; |
| } |
| |
| max_push = src_nritems / 2 + 1; |
| /* don't try to empty the node */ |
| if (max_push >= src_nritems) { |
| return 1; |
| } |
| |
| if (max_push < push_items) |
| push_items = max_push; |
| |
| memmove_extent_buffer(dst, btrfs_node_key_ptr_offset(push_items), |
| btrfs_node_key_ptr_offset(0), |
| (dst_nritems) * |
| sizeof(struct btrfs_key_ptr)); |
| |
| copy_extent_buffer(dst, src, |
| btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(src_nritems - push_items), |
| push_items * sizeof(struct btrfs_key_ptr)); |
| |
| btrfs_set_header_nritems(src, src_nritems - push_items); |
| btrfs_set_header_nritems(dst, dst_nritems + push_items); |
| |
| btrfs_mark_buffer_dirty(src); |
| btrfs_mark_buffer_dirty(dst); |
| return ret; |
| } |
| |
| /* |
| * helper function to insert a new root level in the tree. |
| * A new node is allocated, and a single item is inserted to |
| * point to the existing root |
| * |
| * returns zero on success or < 0 on failure. |
| */ |
| static int noinline insert_new_root(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| u64 root_gen; |
| u64 lower_gen; |
| struct extent_buffer *lower; |
| struct extent_buffer *c; |
| struct extent_buffer *old; |
| struct btrfs_disk_key lower_key; |
| |
| BUG_ON(path->nodes[level]); |
| BUG_ON(path->nodes[level-1] != root->node); |
| |
| if (root->ref_cows) |
| root_gen = trans->transid; |
| else |
| root_gen = 0; |
| |
| lower = path->nodes[level-1]; |
| if (level == 1) |
| btrfs_item_key(lower, &lower_key, 0); |
| else |
| btrfs_node_key(lower, &lower_key, 0); |
| |
| c = btrfs_alloc_free_block(trans, root, root->nodesize, |
| root->root_key.objectid, |
| root_gen, le64_to_cpu(lower_key.objectid), |
| level, root->node->start, 0); |
| if (IS_ERR(c)) |
| return PTR_ERR(c); |
| |
| memset_extent_buffer(c, 0, 0, root->nodesize); |
| btrfs_set_header_nritems(c, 1); |
| btrfs_set_header_level(c, level); |
| btrfs_set_header_bytenr(c, c->start); |
| btrfs_set_header_generation(c, trans->transid); |
| btrfs_set_header_owner(c, root->root_key.objectid); |
| |
| write_extent_buffer(c, root->fs_info->fsid, |
| (unsigned long)btrfs_header_fsid(c), |
| BTRFS_FSID_SIZE); |
| |
| write_extent_buffer(c, root->fs_info->chunk_tree_uuid, |
| (unsigned long)btrfs_header_chunk_tree_uuid(c), |
| BTRFS_UUID_SIZE); |
| |
| btrfs_set_node_key(c, &lower_key, 0); |
| btrfs_set_node_blockptr(c, 0, lower->start); |
| lower_gen = btrfs_header_generation(lower); |
| WARN_ON(lower_gen == 0); |
| |
| btrfs_set_node_ptr_generation(c, 0, lower_gen); |
| |
| btrfs_mark_buffer_dirty(c); |
| |
| spin_lock(&root->node_lock); |
| old = root->node; |
| root->node = c; |
| spin_unlock(&root->node_lock); |
| |
| /* the super has an extra ref to root->node */ |
| free_extent_buffer(old); |
| |
| add_root_to_dirty_list(root); |
| extent_buffer_get(c); |
| path->nodes[level] = c; |
| path->locks[level] = 1; |
| path->slots[level] = 0; |
| |
| if (root->ref_cows && lower_gen != trans->transid) { |
| struct btrfs_path *back_path = btrfs_alloc_path(); |
| int ret; |
| mutex_lock(&root->fs_info->alloc_mutex); |
| ret = btrfs_insert_extent_backref(trans, |
| root->fs_info->extent_root, |
| path, lower->start, |
| root->root_key.objectid, |
| trans->transid, 0, 0); |
| BUG_ON(ret); |
| mutex_unlock(&root->fs_info->alloc_mutex); |
| btrfs_free_path(back_path); |
| } |
| return 0; |
| } |
| |
| /* |
| * worker function to insert a single pointer in a node. |
| * the node should have enough room for the pointer already |
| * |
| * slot and level indicate where you want the key to go, and |
| * blocknr is the block the key points to. |
| * |
| * returns zero on success and < 0 on any error |
| */ |
| static int insert_ptr(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, struct btrfs_disk_key |
| *key, u64 bytenr, int slot, int level) |
| { |
| struct extent_buffer *lower; |
| int nritems; |
| |
| BUG_ON(!path->nodes[level]); |
| lower = path->nodes[level]; |
| nritems = btrfs_header_nritems(lower); |
| if (slot > nritems) |
| BUG(); |
| if (nritems == BTRFS_NODEPTRS_PER_BLOCK(root)) |
| BUG(); |
| if (slot != nritems) { |
| memmove_extent_buffer(lower, |
| btrfs_node_key_ptr_offset(slot + 1), |
| btrfs_node_key_ptr_offset(slot), |
| (nritems - slot) * sizeof(struct btrfs_key_ptr)); |
| } |
| btrfs_set_node_key(lower, key, slot); |
| btrfs_set_node_blockptr(lower, slot, bytenr); |
| WARN_ON(trans->transid == 0); |
| btrfs_set_node_ptr_generation(lower, slot, trans->transid); |
| btrfs_set_header_nritems(lower, nritems + 1); |
| btrfs_mark_buffer_dirty(lower); |
| return 0; |
| } |
| |
| /* |
| * split the node at the specified level in path in two. |
| * The path is corrected to point to the appropriate node after the split |
| * |
| * Before splitting this tries to make some room in the node by pushing |
| * left and right, if either one works, it returns right away. |
| * |
| * returns 0 on success and < 0 on failure |
| */ |
| static noinline int split_node(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, int level) |
| { |
| u64 root_gen; |
| struct extent_buffer *c; |
| struct extent_buffer *split; |
| struct btrfs_disk_key disk_key; |
| int mid; |
| int ret; |
| int wret; |
| u32 c_nritems; |
| |
| c = path->nodes[level]; |
| WARN_ON(btrfs_header_generation(c) != trans->transid); |
| if (c == root->node) { |
| /* trying to split the root, lets make a new one */ |
| ret = insert_new_root(trans, root, path, level + 1); |
| if (ret) |
| return ret; |
| } else { |
| ret = push_nodes_for_insert(trans, root, path, level); |
| c = path->nodes[level]; |
| if (!ret && btrfs_header_nritems(c) < |
| BTRFS_NODEPTRS_PER_BLOCK(root) - 3) |
| return 0; |
| if (ret < 0) |
| return ret; |
| } |
| |
| c_nritems = btrfs_header_nritems(c); |
| if (root->ref_cows) |
| root_gen = trans->transid; |
| else |
| root_gen = 0; |
| |
| btrfs_node_key(c, &disk_key, 0); |
| split = btrfs_alloc_free_block(trans, root, root->nodesize, |
| root->root_key.objectid, |
| root_gen, |
| btrfs_disk_key_objectid(&disk_key), |
| level, c->start, 0); |
| if (IS_ERR(split)) |
| return PTR_ERR(split); |
| |
| btrfs_set_header_flags(split, btrfs_header_flags(c)); |
| btrfs_set_header_level(split, btrfs_header_level(c)); |
| btrfs_set_header_bytenr(split, split->start); |
| btrfs_set_header_generation(split, trans->transid); |
| btrfs_set_header_owner(split, root->root_key.objectid); |
| btrfs_set_header_flags(split, 0); |
| write_extent_buffer(split, root->fs_info->fsid, |
| (unsigned long)btrfs_header_fsid(split), |
| BTRFS_FSID_SIZE); |
| write_extent_buffer(split, root->fs_info->chunk_tree_uuid, |
| (unsigned long)btrfs_header_chunk_tree_uuid(split), |
| BTRFS_UUID_SIZE); |
| |
| mid = (c_nritems + 1) / 2; |
| |
| copy_extent_buffer(split, c, |
| btrfs_node_key_ptr_offset(0), |
| btrfs_node_key_ptr_offset(mid), |
| (c_nritems - mid) * sizeof(struct btrfs_key_ptr)); |
| btrfs_set_header_nritems(split, c_nritems - mid); |
| btrfs_set_header_nritems(c, mid); |
| ret = 0; |
| |
| btrfs_mark_buffer_dirty(c); |
| btrfs_mark_buffer_dirty(split); |
| |
| btrfs_node_key(split, &disk_key, 0); |
| wret = insert_ptr(trans, root, path, &disk_key, split->start, |
| path->slots[level + 1] + 1, |
| level + 1); |
| if (wret) |
| ret = wret; |
| |
| if (path->slots[level] >= mid) { |
| path->slots[level] -= mid; |
| btrfs_tree_unlock(c); |
| free_extent_buffer(c); |
| path->nodes[level] = split; |
| path->slots[level + 1] += 1; |
| } else { |
| btrfs_tree_unlock(split); |
| free_extent_buffer(split); |
| } |
| return ret; |
| } |
| |
| /* |
| * how many bytes are required to store the items in a leaf. start |
| * and nr indicate which items in the leaf to check. This totals up the |
| * space used both by the item structs and the item data |
| */ |
| static int leaf_space_used(struct extent_buffer *l, int start, int nr) |
| { |
| int data_len; |
| int nritems = btrfs_header_nritems(l); |
| int end = min(nritems, start + nr) - 1; |
| |
| if (!nr) |
| return 0; |
| data_len = btrfs_item_end_nr(l, start); |
| data_len = data_len - btrfs_item_offset_nr(l, end); |
| data_len += sizeof(struct btrfs_item) * nr; |
| WARN_ON(data_len < 0); |
| return data_len; |
| } |
| |
| /* |
| * The space between the end of the leaf items and |
| * the start of the leaf data. IOW, how much room |
| * the leaf has left for both items and data |
| */ |
| int noinline btrfs_leaf_free_space(struct btrfs_root *root, |
| struct extent_buffer *leaf) |
| { |
| int nritems = btrfs_header_nritems(leaf); |
| int ret; |
| ret = BTRFS_LEAF_DATA_SIZE(root) - leaf_space_used(leaf, 0, nritems); |
| if (ret < 0) { |
| printk("leaf free space ret %d, leaf data size %lu, used %d nritems %d\n", |
| ret, (unsigned long) BTRFS_LEAF_DATA_SIZE(root), |
| leaf_space_used(leaf, 0, nritems), nritems); |
| } |
| return ret; |
| } |
| |
| /* |
| * push some data in the path leaf to the right, trying to free up at |
| * least data_size bytes. returns zero if the push worked, nonzero otherwise |
| * |
| * returns 1 if the push failed because the other node didn't have enough |
| * room, 0 if everything worked out and < 0 if there were major errors. |
| */ |
| static int push_leaf_right(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int data_size, |
| int empty) |
| { |
| struct extent_buffer *left = path->nodes[0]; |
| struct extent_buffer *right; |
| struct extent_buffer *upper; |
| struct btrfs_disk_key disk_key; |
| int slot; |
| u32 i; |
| int free_space; |
| int push_space = 0; |
| int push_items = 0; |
| struct btrfs_item *item; |
| u32 left_nritems; |
| u32 nr; |
| u32 right_nritems; |
| u32 data_end; |
| u32 this_item_size; |
| int ret; |
| |
| slot = path->slots[1]; |
| if (!path->nodes[1]) { |
| return 1; |
| } |
| upper = path->nodes[1]; |
| if (slot >= btrfs_header_nritems(upper) - 1) |
| return 1; |
| |
| WARN_ON(!btrfs_tree_locked(path->nodes[1])); |
| |
| right = read_node_slot(root, upper, slot + 1); |
| btrfs_tree_lock(right); |
| free_space = btrfs_leaf_free_space(root, right); |
| if (free_space < data_size + sizeof(struct btrfs_item)) |
| goto out_unlock; |
| |
| /* cow and double check */ |
| ret = btrfs_cow_block(trans, root, right, upper, |
| slot + 1, &right, 0); |
| if (ret) |
| goto out_unlock; |
| |
| free_space = btrfs_leaf_free_space(root, right); |
| if (free_space < data_size + sizeof(struct btrfs_item)) |
| goto out_unlock; |
| |
| left_nritems = btrfs_header_nritems(left); |
| if (left_nritems == 0) |
| goto out_unlock; |
| |
| if (empty) |
| nr = 0; |
| else |
| nr = 1; |
| |
| i = left_nritems - 1; |
| while (i >= nr) { |
| item = btrfs_item_nr(left, i); |
| |
| if (path->slots[0] == i) |
| push_space += data_size + sizeof(*item); |
| |
| if (!left->map_token) { |
| map_extent_buffer(left, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &left->map_token, &left->kaddr, |
| &left->map_start, &left->map_len, |
| KM_USER1); |
| } |
| |
| this_item_size = btrfs_item_size(left, item); |
| if (this_item_size + sizeof(*item) + push_space > free_space) |
| break; |
| push_items++; |
| push_space += this_item_size + sizeof(*item); |
| if (i == 0) |
| break; |
| i--; |
| } |
| if (left->map_token) { |
| unmap_extent_buffer(left, left->map_token, KM_USER1); |
| left->map_token = NULL; |
| } |
| |
| if (push_items == 0) |
| goto out_unlock; |
| |
| if (!empty && push_items == left_nritems) |
| WARN_ON(1); |
| |
| /* push left to right */ |
| right_nritems = btrfs_header_nritems(right); |
| |
| push_space = btrfs_item_end_nr(left, left_nritems - push_items); |
| push_space -= leaf_data_end(root, left); |
| |
| /* make room in the right data area */ |
| data_end = leaf_data_end(root, right); |
| memmove_extent_buffer(right, |
| btrfs_leaf_data(right) + data_end - push_space, |
| btrfs_leaf_data(right) + data_end, |
| BTRFS_LEAF_DATA_SIZE(root) - data_end); |
| |
| /* copy from the left data area */ |
| copy_extent_buffer(right, left, btrfs_leaf_data(right) + |
| BTRFS_LEAF_DATA_SIZE(root) - push_space, |
| btrfs_leaf_data(left) + leaf_data_end(root, left), |
| push_space); |
| |
| memmove_extent_buffer(right, btrfs_item_nr_offset(push_items), |
| btrfs_item_nr_offset(0), |
| right_nritems * sizeof(struct btrfs_item)); |
| |
| /* copy the items from left to right */ |
| copy_extent_buffer(right, left, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(left_nritems - push_items), |
| push_items * sizeof(struct btrfs_item)); |
| |
| /* update the item pointers */ |
| right_nritems += push_items; |
| btrfs_set_header_nritems(right, right_nritems); |
| push_space = BTRFS_LEAF_DATA_SIZE(root); |
| for (i = 0; i < right_nritems; i++) { |
| item = btrfs_item_nr(right, i); |
| if (!right->map_token) { |
| map_extent_buffer(right, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &right->map_token, &right->kaddr, |
| &right->map_start, &right->map_len, |
| KM_USER1); |
| } |
| push_space -= btrfs_item_size(right, item); |
| btrfs_set_item_offset(right, item, push_space); |
| } |
| |
| if (right->map_token) { |
| unmap_extent_buffer(right, right->map_token, KM_USER1); |
| right->map_token = NULL; |
| } |
| left_nritems -= push_items; |
| btrfs_set_header_nritems(left, left_nritems); |
| |
| if (left_nritems) |
| btrfs_mark_buffer_dirty(left); |
| btrfs_mark_buffer_dirty(right); |
| |
| btrfs_item_key(right, &disk_key, 0); |
| btrfs_set_node_key(upper, &disk_key, slot + 1); |
| btrfs_mark_buffer_dirty(upper); |
| |
| /* then fixup the leaf pointer in the path */ |
| if (path->slots[0] >= left_nritems) { |
| path->slots[0] -= left_nritems; |
| if (btrfs_header_nritems(path->nodes[0]) == 0) |
| clean_tree_block(trans, root, path->nodes[0]); |
| btrfs_tree_unlock(path->nodes[0]); |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[1] += 1; |
| } else { |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| } |
| return 0; |
| |
| out_unlock: |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| return 1; |
| } |
| |
| /* |
| * push some data in the path leaf to the left, trying to free up at |
| * least data_size bytes. returns zero if the push worked, nonzero otherwise |
| */ |
| static int push_leaf_left(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_path *path, int data_size, |
| int empty) |
| { |
| struct btrfs_disk_key disk_key; |
| struct extent_buffer *right = path->nodes[0]; |
| struct extent_buffer *left; |
| int slot; |
| int i; |
| int free_space; |
| int push_space = 0; |
| int push_items = 0; |
| struct btrfs_item *item; |
| u32 old_left_nritems; |
| u32 right_nritems; |
| u32 nr; |
| int ret = 0; |
| int wret; |
| u32 this_item_size; |
| u32 old_left_item_size; |
| |
| slot = path->slots[1]; |
| if (slot == 0) |
| return 1; |
| if (!path->nodes[1]) |
| return 1; |
| |
| right_nritems = btrfs_header_nritems(right); |
| if (right_nritems == 0) { |
| return 1; |
| } |
| |
| WARN_ON(!btrfs_tree_locked(path->nodes[1])); |
| |
| left = read_node_slot(root, path->nodes[1], slot - 1); |
| btrfs_tree_lock(left); |
| free_space = btrfs_leaf_free_space(root, left); |
| if (free_space < data_size + sizeof(struct btrfs_item)) { |
| ret = 1; |
| goto out; |
| } |
| |
| /* cow and double check */ |
| ret = btrfs_cow_block(trans, root, left, |
| path->nodes[1], slot - 1, &left, 0); |
| if (ret) { |
| /* we hit -ENOSPC, but it isn't fatal here */ |
| ret = 1; |
| goto out; |
| } |
| |
| free_space = btrfs_leaf_free_space(root, left); |
| if (free_space < data_size + sizeof(struct btrfs_item)) { |
| ret = 1; |
| goto out; |
| } |
| |
| if (empty) |
| nr = right_nritems; |
| else |
| nr = right_nritems - 1; |
| |
| for (i = 0; i < nr; i++) { |
| item = btrfs_item_nr(right, i); |
| if (!right->map_token) { |
| map_extent_buffer(right, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &right->map_token, &right->kaddr, |
| &right->map_start, &right->map_len, |
| KM_USER1); |
| } |
| |
| if (path->slots[0] == i) |
| push_space += data_size + sizeof(*item); |
| |
| this_item_size = btrfs_item_size(right, item); |
| if (this_item_size + sizeof(*item) + push_space > free_space) |
| break; |
| |
| push_items++; |
| push_space += this_item_size + sizeof(*item); |
| } |
| |
| if (right->map_token) { |
| unmap_extent_buffer(right, right->map_token, KM_USER1); |
| right->map_token = NULL; |
| } |
| |
| if (push_items == 0) { |
| ret = 1; |
| goto out; |
| } |
| if (!empty && push_items == btrfs_header_nritems(right)) |
| WARN_ON(1); |
| |
| /* push data from right to left */ |
| copy_extent_buffer(left, right, |
| btrfs_item_nr_offset(btrfs_header_nritems(left)), |
| btrfs_item_nr_offset(0), |
| push_items * sizeof(struct btrfs_item)); |
| |
| push_space = BTRFS_LEAF_DATA_SIZE(root) - |
| btrfs_item_offset_nr(right, push_items -1); |
| |
| copy_extent_buffer(left, right, btrfs_leaf_data(left) + |
| leaf_data_end(root, left) - push_space, |
| btrfs_leaf_data(right) + |
| btrfs_item_offset_nr(right, push_items - 1), |
| push_space); |
| old_left_nritems = btrfs_header_nritems(left); |
| BUG_ON(old_left_nritems < 0); |
| |
| old_left_item_size = btrfs_item_offset_nr(left, old_left_nritems - 1); |
| for (i = old_left_nritems; i < old_left_nritems + push_items; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(left, i); |
| if (!left->map_token) { |
| map_extent_buffer(left, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &left->map_token, &left->kaddr, |
| &left->map_start, &left->map_len, |
| KM_USER1); |
| } |
| |
| ioff = btrfs_item_offset(left, item); |
| btrfs_set_item_offset(left, item, |
| ioff - (BTRFS_LEAF_DATA_SIZE(root) - old_left_item_size)); |
| } |
| btrfs_set_header_nritems(left, old_left_nritems + push_items); |
| if (left->map_token) { |
| unmap_extent_buffer(left, left->map_token, KM_USER1); |
| left->map_token = NULL; |
| } |
| |
| /* fixup right node */ |
| if (push_items > right_nritems) { |
| printk("push items %d nr %u\n", push_items, right_nritems); |
| WARN_ON(1); |
| } |
| |
| if (push_items < right_nritems) { |
| push_space = btrfs_item_offset_nr(right, push_items - 1) - |
| leaf_data_end(root, right); |
| memmove_extent_buffer(right, btrfs_leaf_data(right) + |
| BTRFS_LEAF_DATA_SIZE(root) - push_space, |
| btrfs_leaf_data(right) + |
| leaf_data_end(root, right), push_space); |
| |
| memmove_extent_buffer(right, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(push_items), |
| (btrfs_header_nritems(right) - push_items) * |
| sizeof(struct btrfs_item)); |
| } |
| right_nritems -= push_items; |
| btrfs_set_header_nritems(right, right_nritems); |
| push_space = BTRFS_LEAF_DATA_SIZE(root); |
| for (i = 0; i < right_nritems; i++) { |
| item = btrfs_item_nr(right, i); |
| |
| if (!right->map_token) { |
| map_extent_buffer(right, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &right->map_token, &right->kaddr, |
| &right->map_start, &right->map_len, |
| KM_USER1); |
| } |
| |
| push_space = push_space - btrfs_item_size(right, item); |
| btrfs_set_item_offset(right, item, push_space); |
| } |
| if (right->map_token) { |
| unmap_extent_buffer(right, right->map_token, KM_USER1); |
| right->map_token = NULL; |
| } |
| |
| btrfs_mark_buffer_dirty(left); |
| if (right_nritems) |
| btrfs_mark_buffer_dirty(right); |
| |
| btrfs_item_key(right, &disk_key, 0); |
| wret = fixup_low_keys(trans, root, path, &disk_key, 1); |
| if (wret) |
| ret = wret; |
| |
| /* then fixup the leaf pointer in the path */ |
| if (path->slots[0] < push_items) { |
| path->slots[0] += old_left_nritems; |
| if (btrfs_header_nritems(path->nodes[0]) == 0) |
| clean_tree_block(trans, root, path->nodes[0]); |
| btrfs_tree_unlock(path->nodes[0]); |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = left; |
| path->slots[1] -= 1; |
| } else { |
| btrfs_tree_unlock(left); |
| free_extent_buffer(left); |
| path->slots[0] -= push_items; |
| } |
| BUG_ON(path->slots[0] < 0); |
| return ret; |
| out: |
| btrfs_tree_unlock(left); |
| free_extent_buffer(left); |
| return ret; |
| } |
| |
| /* |
| * split the path's leaf in two, making sure there is at least data_size |
| * available for the resulting leaf level of the path. |
| * |
| * returns 0 if all went well and < 0 on failure. |
| */ |
| static noinline int split_leaf(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_key *ins_key, |
| struct btrfs_path *path, int data_size, |
| int extend) |
| { |
| u64 root_gen; |
| struct extent_buffer *l; |
| u32 nritems; |
| int mid; |
| int slot; |
| struct extent_buffer *right; |
| int space_needed = data_size + sizeof(struct btrfs_item); |
| int data_copy_size; |
| int rt_data_off; |
| int i; |
| int ret = 0; |
| int wret; |
| int double_split; |
| int num_doubles = 0; |
| struct btrfs_disk_key disk_key; |
| |
| if (extend) |
| space_needed = data_size; |
| |
| if (root->ref_cows) |
| root_gen = trans->transid; |
| else |
| root_gen = 0; |
| |
| /* first try to make some room by pushing left and right */ |
| if (ins_key->type != BTRFS_DIR_ITEM_KEY) { |
| wret = push_leaf_right(trans, root, path, data_size, 0); |
| if (wret < 0) { |
| return wret; |
| } |
| if (wret) { |
| wret = push_leaf_left(trans, root, path, data_size, 0); |
| if (wret < 0) |
| return wret; |
| } |
| l = path->nodes[0]; |
| |
| /* did the pushes work? */ |
| if (btrfs_leaf_free_space(root, l) >= space_needed) |
| return 0; |
| } |
| |
| if (!path->nodes[1]) { |
| ret = insert_new_root(trans, root, path, 1); |
| if (ret) |
| return ret; |
| } |
| again: |
| double_split = 0; |
| l = path->nodes[0]; |
| slot = path->slots[0]; |
| nritems = btrfs_header_nritems(l); |
| mid = (nritems + 1)/ 2; |
| |
| btrfs_item_key(l, &disk_key, 0); |
| |
| right = btrfs_alloc_free_block(trans, root, root->leafsize, |
| root->root_key.objectid, |
| root_gen, |
| le64_to_cpu(disk_key.objectid), |
| 0, l->start, 0); |
| if (IS_ERR(right)) { |
| BUG_ON(1); |
| return PTR_ERR(right); |
| } |
| |
| memset_extent_buffer(right, 0, 0, sizeof(struct btrfs_header)); |
| btrfs_set_header_bytenr(right, right->start); |
| btrfs_set_header_generation(right, trans->transid); |
| btrfs_set_header_owner(right, root->root_key.objectid); |
| btrfs_set_header_level(right, 0); |
| write_extent_buffer(right, root->fs_info->fsid, |
| (unsigned long)btrfs_header_fsid(right), |
| BTRFS_FSID_SIZE); |
| |
| write_extent_buffer(right, root->fs_info->chunk_tree_uuid, |
| (unsigned long)btrfs_header_chunk_tree_uuid(right), |
| BTRFS_UUID_SIZE); |
| if (mid <= slot) { |
| if (nritems == 1 || |
| leaf_space_used(l, mid, nritems - mid) + space_needed > |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| if (slot >= nritems) { |
| btrfs_cpu_key_to_disk(&disk_key, ins_key); |
| btrfs_set_header_nritems(right, 0); |
| wret = insert_ptr(trans, root, path, |
| &disk_key, right->start, |
| path->slots[1] + 1, 1); |
| if (wret) |
| ret = wret; |
| |
| btrfs_tree_unlock(path->nodes[0]); |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] = 0; |
| path->slots[1] += 1; |
| btrfs_mark_buffer_dirty(right); |
| return ret; |
| } |
| mid = slot; |
| if (mid != nritems && |
| leaf_space_used(l, mid, nritems - mid) + |
| space_needed > BTRFS_LEAF_DATA_SIZE(root)) { |
| double_split = 1; |
| } |
| } |
| } else { |
| if (leaf_space_used(l, 0, mid + 1) + space_needed > |
| BTRFS_LEAF_DATA_SIZE(root)) { |
| if (!extend && slot == 0) { |
| btrfs_cpu_key_to_disk(&disk_key, ins_key); |
| btrfs_set_header_nritems(right, 0); |
| wret = insert_ptr(trans, root, path, |
| &disk_key, |
| right->start, |
| path->slots[1], 1); |
| if (wret) |
| ret = wret; |
| btrfs_tree_unlock(path->nodes[0]); |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] = 0; |
| if (path->slots[1] == 0) { |
| wret = fixup_low_keys(trans, root, |
| path, &disk_key, 1); |
| if (wret) |
| ret = wret; |
| } |
| btrfs_mark_buffer_dirty(right); |
| return ret; |
| } else if (extend && slot == 0) { |
| mid = 1; |
| } else { |
| mid = slot; |
| if (mid != nritems && |
| leaf_space_used(l, mid, nritems - mid) + |
| space_needed > BTRFS_LEAF_DATA_SIZE(root)) { |
| double_split = 1; |
| } |
| } |
| } |
| } |
| nritems = nritems - mid; |
| btrfs_set_header_nritems(right, nritems); |
| data_copy_size = btrfs_item_end_nr(l, mid) - leaf_data_end(root, l); |
| |
| copy_extent_buffer(right, l, btrfs_item_nr_offset(0), |
| btrfs_item_nr_offset(mid), |
| nritems * sizeof(struct btrfs_item)); |
| |
| copy_extent_buffer(right, l, |
| btrfs_leaf_data(right) + BTRFS_LEAF_DATA_SIZE(root) - |
| data_copy_size, btrfs_leaf_data(l) + |
| leaf_data_end(root, l), data_copy_size); |
| |
| rt_data_off = BTRFS_LEAF_DATA_SIZE(root) - |
| btrfs_item_end_nr(l, mid); |
| |
| for (i = 0; i < nritems; i++) { |
| struct btrfs_item *item = btrfs_item_nr(right, i); |
| u32 ioff; |
| |
| if (!right->map_token) { |
| map_extent_buffer(right, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &right->map_token, &right->kaddr, |
| &right->map_start, &right->map_len, |
| KM_USER1); |
| } |
| |
| ioff = btrfs_item_offset(right, item); |
| btrfs_set_item_offset(right, item, ioff + rt_data_off); |
| } |
| |
| if (right->map_token) { |
| unmap_extent_buffer(right, right->map_token, KM_USER1); |
| right->map_token = NULL; |
| } |
| |
| btrfs_set_header_nritems(l, mid); |
| ret = 0; |
| btrfs_item_key(right, &disk_key, 0); |
| wret = insert_ptr(trans, root, path, &disk_key, right->start, |
| path->slots[1] + 1, 1); |
| if (wret) |
| ret = wret; |
| |
| btrfs_mark_buffer_dirty(right); |
| btrfs_mark_buffer_dirty(l); |
| BUG_ON(path->slots[0] != slot); |
| |
| if (mid <= slot) { |
| btrfs_tree_unlock(path->nodes[0]); |
| free_extent_buffer(path->nodes[0]); |
| path->nodes[0] = right; |
| path->slots[0] -= mid; |
| path->slots[1] += 1; |
| } else { |
| btrfs_tree_unlock(right); |
| free_extent_buffer(right); |
| } |
| |
| BUG_ON(path->slots[0] < 0); |
| |
| if (double_split) { |
| BUG_ON(num_doubles != 0); |
| num_doubles++; |
| goto again; |
| } |
| return ret; |
| } |
| |
| int btrfs_truncate_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| u32 new_size, int from_end) |
| { |
| int ret = 0; |
| int slot; |
| int slot_orig; |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| u32 nritems; |
| unsigned int data_end; |
| unsigned int old_data_start; |
| unsigned int old_size; |
| unsigned int size_diff; |
| int i; |
| |
| slot_orig = path->slots[0]; |
| leaf = path->nodes[0]; |
| slot = path->slots[0]; |
| |
| old_size = btrfs_item_size_nr(leaf, slot); |
| if (old_size == new_size) |
| return 0; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| old_data_start = btrfs_item_offset_nr(leaf, slot); |
| |
| size_diff = old_size - new_size; |
| |
| BUG_ON(slot < 0); |
| BUG_ON(slot >= nritems); |
| |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| item = btrfs_item_nr(leaf, i); |
| |
| if (!leaf->map_token) { |
| map_extent_buffer(leaf, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &leaf->map_token, &leaf->kaddr, |
| &leaf->map_start, &leaf->map_len, |
| KM_USER1); |
| } |
| |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff + size_diff); |
| } |
| |
| if (leaf->map_token) { |
| unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); |
| leaf->map_token = NULL; |
| } |
| |
| /* shift the data */ |
| if (from_end) { |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + size_diff, btrfs_leaf_data(leaf) + |
| data_end, old_data_start + new_size - data_end); |
| } else { |
| struct btrfs_disk_key disk_key; |
| u64 offset; |
| |
| btrfs_item_key(leaf, &disk_key, slot); |
| |
| if (btrfs_disk_key_type(&disk_key) == BTRFS_EXTENT_DATA_KEY) { |
| unsigned long ptr; |
| struct btrfs_file_extent_item *fi; |
| |
| fi = btrfs_item_ptr(leaf, slot, |
| struct btrfs_file_extent_item); |
| fi = (struct btrfs_file_extent_item *)( |
| (unsigned long)fi - size_diff); |
| |
| if (btrfs_file_extent_type(leaf, fi) == |
| BTRFS_FILE_EXTENT_INLINE) { |
| ptr = btrfs_item_ptr_offset(leaf, slot); |
| memmove_extent_buffer(leaf, ptr, |
| (unsigned long)fi, |
| offsetof(struct btrfs_file_extent_item, |
| disk_bytenr)); |
| } |
| } |
| |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + size_diff, btrfs_leaf_data(leaf) + |
| data_end, old_data_start - data_end); |
| |
| offset = btrfs_disk_key_offset(&disk_key); |
| btrfs_set_disk_key_offset(&disk_key, offset + size_diff); |
| btrfs_set_item_key(leaf, &disk_key, slot); |
| if (slot == 0) |
| fixup_low_keys(trans, root, path, &disk_key, 1); |
| } |
| |
| item = btrfs_item_nr(leaf, slot); |
| btrfs_set_item_size(leaf, item, new_size); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| return ret; |
| } |
| |
| int btrfs_extend_item(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, struct btrfs_path *path, |
| u32 data_size) |
| { |
| int ret = 0; |
| int slot; |
| int slot_orig; |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| u32 nritems; |
| unsigned int data_end; |
| unsigned int old_data; |
| unsigned int old_size; |
| int i; |
| |
| slot_orig = path->slots[0]; |
| leaf = path->nodes[0]; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| if (btrfs_leaf_free_space(root, leaf) < data_size) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| slot = path->slots[0]; |
| old_data = btrfs_item_end_nr(leaf, slot); |
| |
| BUG_ON(slot < 0); |
| if (slot >= nritems) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d too large, nritems %d\n", slot, nritems); |
| BUG_ON(1); |
| } |
| |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| item = btrfs_item_nr(leaf, i); |
| |
| if (!leaf->map_token) { |
| map_extent_buffer(leaf, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &leaf->map_token, &leaf->kaddr, |
| &leaf->map_start, &leaf->map_len, |
| KM_USER1); |
| } |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff - data_size); |
| } |
| |
| if (leaf->map_token) { |
| unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); |
| leaf->map_token = NULL; |
| } |
| |
| /* shift the data */ |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end - data_size, btrfs_leaf_data(leaf) + |
| data_end, old_data - data_end); |
| |
| data_end = old_data; |
| old_size = btrfs_item_size_nr(leaf, slot); |
| item = btrfs_item_nr(leaf, slot); |
| btrfs_set_item_size(leaf, item, old_size + data_size); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| return ret; |
| } |
| |
| /* |
| * Given a key and some data, insert an item into the tree. |
| * This does all the path init required, making room in the tree if needed. |
| */ |
| int btrfs_insert_empty_items(struct btrfs_trans_handle *trans, |
| struct btrfs_root *root, |
| struct btrfs_path *path, |
| struct btrfs_key *cpu_key, u32 *data_size, |
| int nr) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| int ret = 0; |
| int slot; |
| int slot_orig; |
| int i; |
| u32 nritems; |
| u32 total_size = 0; |
| u32 total_data = 0; |
| unsigned int data_end; |
| struct btrfs_disk_key disk_key; |
| |
| for (i = 0; i < nr; i++) { |
| total_data += data_size[i]; |
| } |
| |
| total_size = total_data + (nr * sizeof(struct btrfs_item)); |
| ret = btrfs_search_slot(trans, root, cpu_key, path, total_size, 1); |
| if (ret == 0) |
| return -EEXIST; |
| if (ret < 0) |
| goto out; |
| |
| slot_orig = path->slots[0]; |
| leaf = path->nodes[0]; |
| |
| nritems = btrfs_header_nritems(leaf); |
| data_end = leaf_data_end(root, leaf); |
| |
| if (btrfs_leaf_free_space(root, leaf) < total_size) { |
| btrfs_print_leaf(root, leaf); |
| printk("not enough freespace need %u have %d\n", |
| total_size, btrfs_leaf_free_space(root, leaf)); |
| BUG(); |
| } |
| |
| slot = path->slots[0]; |
| BUG_ON(slot < 0); |
| |
| if (slot != nritems) { |
| unsigned int old_data = btrfs_item_end_nr(leaf, slot); |
| |
| if (old_data < data_end) { |
| btrfs_print_leaf(root, leaf); |
| printk("slot %d old_data %d data_end %d\n", |
| slot, old_data, data_end); |
| BUG_ON(1); |
| } |
| /* |
| * item0..itemN ... dataN.offset..dataN.size .. data0.size |
| */ |
| /* first correct the data pointers */ |
| WARN_ON(leaf->map_token); |
| for (i = slot; i < nritems; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(leaf, i); |
| if (!leaf->map_token) { |
| map_extent_buffer(leaf, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &leaf->map_token, &leaf->kaddr, |
| &leaf->map_start, &leaf->map_len, |
| KM_USER1); |
| } |
| |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff - total_data); |
| } |
| if (leaf->map_token) { |
| unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); |
| leaf->map_token = NULL; |
| } |
| |
| /* shift the items */ |
| memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot + nr), |
| btrfs_item_nr_offset(slot), |
| (nritems - slot) * sizeof(struct btrfs_item)); |
| |
| /* shift the data */ |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end - total_data, btrfs_leaf_data(leaf) + |
| data_end, old_data - data_end); |
| data_end = old_data; |
| } |
| |
| /* setup the item for the new data */ |
| for (i = 0; i < nr; i++) { |
| btrfs_cpu_key_to_disk(&disk_key, cpu_key + i); |
| btrfs_set_item_key(leaf, &disk_key, slot + i); |
| item = btrfs_item_nr(leaf, slot + i); |
| btrfs_set_item_offset(leaf, item, data_end - data_size[i]); |
| data_end -= data_size[i]; |
| btrfs_set_item_size(leaf, item, data_size[i]); |
| } |
| btrfs_set_header_nritems(leaf, nritems + nr); |
| btrfs_mark_buffer_dirty(leaf); |
| |
| ret = 0; |
| if (slot == 0) { |
| btrfs_cpu_key_to_disk(&disk_key, cpu_key); |
| ret = fixup_low_keys(trans, root, path, &disk_key, 1); |
| } |
| |
| if (btrfs_leaf_free_space(root, leaf) < 0) { |
| btrfs_print_leaf(root, leaf); |
| BUG(); |
| } |
| out: |
| return ret; |
| } |
| |
| /* |
| * Given a key and some data, insert an item into the tree. |
| * This does all the path init required, making room in the tree if needed. |
| */ |
| int btrfs_insert_item(struct btrfs_trans_handle *trans, struct btrfs_root |
| *root, struct btrfs_key *cpu_key, void *data, u32 |
| data_size) |
| { |
| int ret = 0; |
| struct btrfs_path *path; |
| struct extent_buffer *leaf; |
| unsigned long ptr; |
| |
| path = btrfs_alloc_path(); |
| BUG_ON(!path); |
| ret = btrfs_insert_empty_item(trans, root, path, cpu_key, data_size); |
| if (!ret) { |
| leaf = path->nodes[0]; |
| ptr = btrfs_item_ptr_offset(leaf, path->slots[0]); |
| write_extent_buffer(leaf, data, ptr, data_size); |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| btrfs_free_path(path); |
| return ret; |
| } |
| |
| /* |
| * delete the pointer from a given node. |
| * |
| * If the delete empties a node, the node is removed from the tree, |
| * continuing all the way the root if required. The root is converted into |
| * a leaf if all the nodes are emptied. |
| */ |
| static int del_ptr(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct btrfs_path *path, int level, int slot) |
| { |
| struct extent_buffer *parent = path->nodes[level]; |
| u32 nritems; |
| int ret = 0; |
| int wret; |
| |
| nritems = btrfs_header_nritems(parent); |
| if (slot != nritems -1) { |
| memmove_extent_buffer(parent, |
| btrfs_node_key_ptr_offset(slot), |
| btrfs_node_key_ptr_offset(slot + 1), |
| sizeof(struct btrfs_key_ptr) * |
| (nritems - slot - 1)); |
| } |
| nritems--; |
| btrfs_set_header_nritems(parent, nritems); |
| if (nritems == 0 && parent == root->node) { |
| BUG_ON(btrfs_header_level(root->node) != 1); |
| /* just turn the root into a leaf and break */ |
| btrfs_set_header_level(root->node, 0); |
| } else if (slot == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_node_key(parent, &disk_key, 0); |
| wret = fixup_low_keys(trans, root, path, &disk_key, level + 1); |
| if (wret) |
| ret = wret; |
| } |
| btrfs_mark_buffer_dirty(parent); |
| return ret; |
| } |
| |
| /* |
| * delete the item at the leaf level in path. If that empties |
| * the leaf, remove it from the tree |
| */ |
| int btrfs_del_items(struct btrfs_trans_handle *trans, struct btrfs_root *root, |
| struct btrfs_path *path, int slot, int nr) |
| { |
| struct extent_buffer *leaf; |
| struct btrfs_item *item; |
| int last_off; |
| int dsize = 0; |
| int ret = 0; |
| int wret; |
| int i; |
| u32 nritems; |
| |
| leaf = path->nodes[0]; |
| last_off = btrfs_item_offset_nr(leaf, slot + nr - 1); |
| |
| for (i = 0; i < nr; i++) |
| dsize += btrfs_item_size_nr(leaf, slot + i); |
| |
| nritems = btrfs_header_nritems(leaf); |
| |
| if (slot + nr != nritems) { |
| int data_end = leaf_data_end(root, leaf); |
| |
| memmove_extent_buffer(leaf, btrfs_leaf_data(leaf) + |
| data_end + dsize, |
| btrfs_leaf_data(leaf) + data_end, |
| last_off - data_end); |
| |
| for (i = slot + nr; i < nritems; i++) { |
| u32 ioff; |
| |
| item = btrfs_item_nr(leaf, i); |
| if (!leaf->map_token) { |
| map_extent_buffer(leaf, (unsigned long)item, |
| sizeof(struct btrfs_item), |
| &leaf->map_token, &leaf->kaddr, |
| &leaf->map_start, &leaf->map_len, |
| KM_USER1); |
| } |
| ioff = btrfs_item_offset(leaf, item); |
| btrfs_set_item_offset(leaf, item, ioff + dsize); |
| } |
| |
| if (leaf->map_token) { |
| unmap_extent_buffer(leaf, leaf->map_token, KM_USER1); |
| leaf->map_token = NULL; |
| } |
| |
| memmove_extent_buffer(leaf, btrfs_item_nr_offset(slot), |
| btrfs_item_nr_offset(slot + nr), |
| sizeof(struct btrfs_item) * |
| (nritems - slot - nr)); |
| } |
| btrfs_set_header_nritems(leaf, nritems - nr); |
| nritems -= nr; |
| |
| /* delete the leaf if we've emptied it */ |
| if (nritems == 0) { |
| if (leaf == root->node) { |
| btrfs_set_header_level(leaf, 0); |
| } else { |
| u64 root_gen = btrfs_header_generation(path->nodes[1]); |
| wret = del_ptr(trans, root, path, 1, path->slots[1]); |
| if (wret) |
| ret = wret; |
| wret = btrfs_free_extent(trans, root, |
| leaf->start, leaf->len, |
| btrfs_header_owner(path->nodes[1]), |
| root_gen, 0, 0, 1); |
| if (wret) |
| ret = wret; |
| } |
| } else { |
| int used = leaf_space_used(leaf, 0, nritems); |
| if (slot == 0) { |
| struct btrfs_disk_key disk_key; |
| |
| btrfs_item_key(leaf, &disk_key, 0); |
| wret = fixup_low_keys(trans, root, path, |
| &disk_key, 1); |
| if (wret) |
| ret = wret; |
| } |
| |
| /* delete the leaf if it is mostly empty */ |
| if (used < BTRFS_LEAF_DATA_SIZE(root) / 4) { |
| /* push_leaf_left fixes the path. |
| * make sure the path still points to our leaf |
| * for possible call to del_ptr below |
| */ |
| slot = path->slots[1]; |
| extent_buffer_get(leaf); |
| |
| wret = push_leaf_left(trans, root, path, 1, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| |
| if (path->nodes[0] == leaf && |
| btrfs_header_nritems(leaf)) { |
| wret = push_leaf_right(trans, root, path, 1, 1); |
| if (wret < 0 && wret != -ENOSPC) |
| ret = wret; |
| } |
| |
| if (btrfs_header_nritems(leaf) == 0) { |
| u64 root_gen; |
| u64 bytenr = leaf->start; |
| u32 blocksize = leaf->len; |
| |
| root_gen = btrfs_header_generation( |
| path->nodes[1]); |
| |
| wret = del_ptr(trans, root, path, 1, slot); |
| if (wret) |
| ret = wret; |
| |
| free_extent_buffer(leaf); |
| wret = btrfs_free_extent(trans, root, bytenr, |
| blocksize, |
| btrfs_header_owner(path->nodes[1]), |
| root_gen, 0, 0, 1); |
| if (wret) |
| ret = wret; |
| } else { |
| /* if we're still in the path, make sure |
| * we're dirty. Otherwise, one of the |
| * push_leaf functions must have already |
| * dirtied this buffer |
| */ |
| if (path->nodes[0] == leaf) |
| btrfs_mark_buffer_dirty(leaf); |
| free_extent_buffer(leaf); |
| } |
| } else { |
| btrfs_mark_buffer_dirty(leaf); |
| } |
| } |
| return ret; |
| } |
| |
| /* |
| * search the tree again to find a leaf with lesser keys |
| * returns 0 if it found something or 1 if there are no lesser leaves. |
| * returns < 0 on io errors. |
| */ |
| int btrfs_prev_leaf(struct btrfs_root *root, struct btrfs_path *path) |
| { |
| struct btrfs_key key; |
| struct btrfs_disk_key found_key; |
| int ret; |
| |
| btrfs_item_key_to_cpu(path->nodes[0], &key, 0); |
| |
| if (key.offset > 0) |
| key.offset--; |
| else if (key.type > 0) |
| key.type--; |
| else if (key.objectid > 0) |
| key.objectid--; |
| else |
| return 1; |
| |
| btrfs_release_path(root, path); |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| if (ret < 0) |
| return ret; |
| btrfs_item_key(path->nodes[0], &found_key, 0); |
| ret = comp_keys(&found_key, &key); |
| if (ret < 0) |
| return 0; |
| return 1; |
| } |
| |
| /* |
| * A helper function to walk down the tree starting at min_key, and looking |
| * for nodes or leaves that are either in cache or have a minimum |
| * transaction id. This is used by the btree defrag code, but could |
| * also be used to search for blocks that have changed since a given |
| * transaction id. |
| * |
| * This does not cow, but it does stuff the starting key it finds back |
| * into min_key, so you can call btrfs_search_slot with cow=1 on the |
| * key and get a writable path. |
| * |
| * This does lock as it descends, and path->keep_locks should be set |
| * to 1 by the caller. |
| * |
| * This honors path->lowest_level to prevent descent past a given level |
| * of the tree. |
| * |
| * returns zero if something useful was found, < 0 on error and 1 if there |
| * was nothing in the tree that matched the search criteria. |
| */ |
| int btrfs_search_forward(struct btrfs_root *root, struct btrfs_key *min_key, |
| struct btrfs_key *max_key, |
| struct btrfs_path *path, int cache_only, |
| u64 min_trans) |
| { |
| struct extent_buffer *cur; |
| struct btrfs_key found_key; |
| int slot; |
| int sret; |
| u32 nritems; |
| int level; |
| int ret = 1; |
| |
| again: |
| cur = btrfs_lock_root_node(root); |
| level = btrfs_header_level(cur); |
| WARN_ON(path->nodes[level]); |
| path->nodes[level] = cur; |
| path->locks[level] = 1; |
| |
| if (btrfs_header_generation(cur) < min_trans) { |
| ret = 1; |
| goto out; |
| } |
| while(1) { |
| nritems = btrfs_header_nritems(cur); |
| level = btrfs_header_level(cur); |
| sret = bin_search(cur, min_key, level, &slot); |
| |
| /* at level = 0, we're done, setup the path and exit */ |
| if (level == 0) { |
| if (slot >= nritems) |
| goto find_next_key; |
| ret = 0; |
| path->slots[level] = slot; |
| btrfs_item_key_to_cpu(cur, &found_key, slot); |
| goto out; |
| } |
| if (sret && slot > 0) |
| slot--; |
| /* |
| * check this node pointer against the cache_only and |
| * min_trans parameters. If it isn't in cache or is too |
| * old, skip to the next one. |
| */ |
| while(slot < nritems) { |
| u64 blockptr; |
| u64 gen; |
| struct extent_buffer *tmp; |
| struct btrfs_disk_key disk_key; |
| |
| blockptr = btrfs_node_blockptr(cur, slot); |
| gen = btrfs_node_ptr_generation(cur, slot); |
| if (gen < min_trans) { |
| slot++; |
| continue; |
| } |
| if (!cache_only) |
| break; |
| |
| if (max_key) { |
| btrfs_node_key(cur, &disk_key, slot); |
| if (comp_keys(&disk_key, max_key) >= 0) { |
| ret = 1; |
| goto out; |
| } |
| } |
| |
| tmp = btrfs_find_tree_block(root, blockptr, |
| btrfs_level_size(root, level - 1)); |
| |
| if (tmp && btrfs_buffer_uptodate(tmp, gen)) { |
| free_extent_buffer(tmp); |
| break; |
| } |
| if (tmp) |
| free_extent_buffer(tmp); |
| slot++; |
| } |
| find_next_key: |
| /* |
| * we didn't find a candidate key in this node, walk forward |
| * and find another one |
| */ |
| if (slot >= nritems) { |
| path->slots[level] = slot; |
| sret = btrfs_find_next_key(root, path, min_key, level, |
| cache_only, min_trans); |
| if (sret == 0) { |
| btrfs_release_path(root, path); |
| goto again; |
| } else { |
| goto out; |
| } |
| } |
| /* save our key for returning back */ |
| btrfs_node_key_to_cpu(cur, &found_key, slot); |
| path->slots[level] = slot; |
| if (level == path->lowest_level) { |
| ret = 0; |
| unlock_up(path, level, 1); |
| goto out; |
| } |
| cur = read_node_slot(root, cur, slot); |
| |
| btrfs_tree_lock(cur); |
| path->locks[level - 1] = 1; |
| path->nodes[level - 1] = cur; |
| unlock_up(path, level, 1); |
| } |
| out: |
| if (ret == 0) |
| memcpy(min_key, &found_key, sizeof(found_key)); |
| return ret; |
| } |
| |
| /* |
| * this is similar to btrfs_next_leaf, but does not try to preserve |
| * and fixup the path. It looks for and returns the next key in the |
| * tree based on the current path and the cache_only and min_trans |
| * parameters. |
| * |
| * 0 is returned if another key is found, < 0 if there are any errors |
| * and 1 is returned if there are no higher keys in the tree |
| * |
| * path->keep_locks should be set to 1 on the search made before |
| * calling this function. |
| */ |
| int btrfs_find_next_key(struct btrfs_root *root, struct btrfs_path *path, |
| struct btrfs_key *key, int lowest_level, |
| int cache_only, u64 min_trans) |
| { |
| int level = lowest_level; |
| int slot; |
| struct extent_buffer *c; |
| |
| while(level < BTRFS_MAX_LEVEL) { |
| if (!path->nodes[level]) |
| return 1; |
| |
| slot = path->slots[level] + 1; |
| c = path->nodes[level]; |
| next: |
| if (slot >= btrfs_header_nritems(c)) { |
| level++; |
| if (level == BTRFS_MAX_LEVEL) { |
| return 1; |
| } |
| continue; |
| } |
| if (level == 0) |
| btrfs_item_key_to_cpu(c, key, slot); |
| else { |
| u64 blockptr = btrfs_node_blockptr(c, slot); |
| u64 gen = btrfs_node_ptr_generation(c, slot); |
| |
| if (cache_only) { |
| struct extent_buffer *cur; |
| cur = btrfs_find_tree_block(root, blockptr, |
| btrfs_level_size(root, level - 1)); |
| if (!cur || !btrfs_buffer_uptodate(cur, gen)) { |
| slot++; |
| if (cur) |
| free_extent_buffer(cur); |
| goto next; |
| } |
| free_extent_buffer(cur); |
| } |
| if (gen < min_trans) { |
| slot++; |
| goto next; |
| } |
| btrfs_node_key_to_cpu(c, key, slot); |
| } |
| return 0; |
| } |
| return 1; |
| } |
| |
| /* |
| * search the tree again to find a leaf with greater keys |
| * returns 0 if it found something or 1 if there are no greater leaves. |
| * returns < 0 on io errors. |
| */ |
| int btrfs_next_leaf(struct btrfs_root *root, struct btrfs_path *path) |
| { |
| int slot; |
| int level = 1; |
| struct extent_buffer *c; |
| struct extent_buffer *next = NULL; |
| struct btrfs_key key; |
| u32 nritems; |
| int ret; |
| |
| nritems = btrfs_header_nritems(path->nodes[0]); |
| if (nritems == 0) { |
| return 1; |
| } |
| |
| btrfs_item_key_to_cpu(path->nodes[0], &key, nritems - 1); |
| |
| btrfs_release_path(root, path); |
| path->keep_locks = 1; |
| ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); |
| path->keep_locks = 0; |
| |
| if (ret < 0) |
| return ret; |
| |
| nritems = btrfs_header_nritems(path->nodes[0]); |
| /* |
| * by releasing the path above we dropped all our locks. A balance |
| * could have added more items next to the key that used to be |
| * at the very end of the block. So, check again here and |
| * advance the path if there are now more items available. |
| */ |
| if (nritems > 0 && path->slots[0] < nritems - 1) { |
| path->slots[0]++; |
| goto done; |
| } |
| |
| while(level < BTRFS_MAX_LEVEL) { |
| if (!path->nodes[level]) |
| return 1; |
| |
| slot = path->slots[level] + 1; |
| c = path->nodes[level]; |
| if (slot >= btrfs_header_nritems(c)) { |
| level++; |
| if (level == BTRFS_MAX_LEVEL) { |
| return 1; |
| } |
| continue; |
| } |
| |
| if (next) { |
| btrfs_tree_unlock(next); |
| free_extent_buffer(next); |
| } |
| |
| if (level == 1 && (path->locks[1] || path->skip_locking) && |
| path->reada) |
| reada_for_search(root, path, level, slot, 0); |
| |
| next = read_node_slot(root, c, slot); |
| if (!path->skip_locking) { |
| WARN_ON(!btrfs_tree_locked(c)); |
| btrfs_tree_lock(next); |
| } |
| break; |
| } |
| path->slots[level] = slot; |
| while(1) { |
| level--; |
| c = path->nodes[level]; |
| if (path->locks[level]) |
| btrfs_tree_unlock(c); |
| free_extent_buffer(c); |
| path->nodes[level] = next; |
| path->slots[level] = 0; |
| if (!path->skip_locking) |
| path->locks[level] = 1; |
| if (!level) |
| break; |
| if (level == 1 && path->locks[1] && path->reada) |
| reada_for_search(root, path, level, slot, 0); |
| next = read_node_slot(root, next, 0); |
| if (!path->skip_locking) { |
| WARN_ON(!btrfs_tree_locked(path->nodes[level])); |
| btrfs_tree_lock(next); |
| } |
| } |
| done: |
| unlock_up(path, 0, 1); |
| return 0; |
| } |
| |
| /* |
| * this uses btrfs_prev_leaf to walk backwards in the tree, and keeps |
| * searching until it gets past min_objectid or finds an item of 'type' |
| * |
| * returns 0 if something is found, 1 if nothing was found and < 0 on error |
| */ |
| int btrfs_previous_item(struct btrfs_root *root, |
| struct btrfs_path *path, u64 min_objectid, |
| int type) |
| { |
| struct btrfs_key found_key; |
| struct extent_buffer *leaf; |
| u32 nritems; |
| int ret; |
| |
| while(1) { |
| if (path->slots[0] == 0) { |
| ret = btrfs_prev_leaf(root, path); |
| if (ret != 0) |
| return ret; |
| } else { |
| path->slots[0]--; |
| } |
| leaf = path->nodes[0]; |
| nritems = btrfs_header_nritems(leaf); |
| if (nritems == 0) |
| return 1; |
| if (path->slots[0] == nritems) |
| path->slots[0]--; |
| |
| btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); |
| if (found_key.type == type) |
| return 0; |
| if (found_key.objectid < min_objectid) |
| break; |
| if (found_key.objectid == min_objectid && |
| found_key.type < type) |
| break; |
| } |
| return 1; |
| } |