/* * 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 #include #include #include "hash.h" #include "crc32c.h" #include "ctree.h" #include "disk-io.h" #include "print-tree.h" #include "transaction.h" #include "volumes.h" #include "locking.h" #include "ref-cache.h" #define BLOCK_GROUP_DATA EXTENT_WRITEBACK #define BLOCK_GROUP_METADATA EXTENT_UPTODATE #define BLOCK_GROUP_SYSTEM EXTENT_NEW #define BLOCK_GROUP_DIRTY EXTENT_DIRTY static int finish_current_insert(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root); static int del_pending_extents(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root); static struct btrfs_block_group_cache * __btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *hint, u64 search_start, int data, int owner); void maybe_lock_mutex(struct btrfs_root *root) { if (root != root->fs_info->extent_root && root != root->fs_info->chunk_root && root != root->fs_info->dev_root) { mutex_lock(&root->fs_info->alloc_mutex); } } void maybe_unlock_mutex(struct btrfs_root *root) { if (root != root->fs_info->extent_root && root != root->fs_info->chunk_root && root != root->fs_info->dev_root) { mutex_unlock(&root->fs_info->alloc_mutex); } } static int cache_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *block_group) { struct btrfs_path *path; int ret; struct btrfs_key key; struct extent_buffer *leaf; struct extent_io_tree *free_space_cache; int slot; u64 last = 0; u64 hole_size; u64 first_free; int found = 0; if (!block_group) return 0; root = root->fs_info->extent_root; free_space_cache = &root->fs_info->free_space_cache; if (block_group->cached) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 2; /* * we get into deadlocks with paths held by callers of this function. * since the alloc_mutex is protecting things right now, just * skip the locking here */ path->skip_locking = 1; first_free = block_group->key.objectid; key.objectid = block_group->key.objectid; key.offset = 0; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) return ret; ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); if (ret < 0) return ret; if (ret == 0) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid + key.offset > first_free) first_free = key.objectid + key.offset; } while(1) { leaf = path->nodes[0]; slot = path->slots[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto err; if (ret == 0) { continue; } else { break; } } btrfs_item_key_to_cpu(leaf, &key, slot); if (key.objectid < block_group->key.objectid) { goto next; } if (key.objectid >= block_group->key.objectid + block_group->key.offset) { break; } if (btrfs_key_type(&key) == BTRFS_EXTENT_ITEM_KEY) { if (!found) { last = first_free; found = 1; } if (key.objectid > last) { hole_size = key.objectid - last; set_extent_dirty(free_space_cache, last, last + hole_size - 1, GFP_NOFS); } last = key.objectid + key.offset; } next: path->slots[0]++; } if (!found) last = first_free; if (block_group->key.objectid + block_group->key.offset > last) { hole_size = block_group->key.objectid + block_group->key.offset - last; set_extent_dirty(free_space_cache, last, last + hole_size - 1, GFP_NOFS); } block_group->cached = 1; err: btrfs_free_path(path); return 0; } struct btrfs_block_group_cache *btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr) { struct extent_io_tree *block_group_cache; struct btrfs_block_group_cache *block_group = NULL; u64 ptr; u64 start; u64 end; int ret; bytenr = max_t(u64, bytenr, BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); block_group_cache = &info->block_group_cache; ret = find_first_extent_bit(block_group_cache, bytenr, &start, &end, BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | BLOCK_GROUP_SYSTEM); if (ret) { return NULL; } ret = get_state_private(block_group_cache, start, &ptr); if (ret) return NULL; block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr; return block_group; } struct btrfs_block_group_cache *btrfs_lookup_block_group(struct btrfs_fs_info *info, u64 bytenr) { struct extent_io_tree *block_group_cache; struct btrfs_block_group_cache *block_group = NULL; u64 ptr; u64 start; u64 end; int ret; bytenr = max_t(u64, bytenr, BTRFS_SUPER_INFO_OFFSET + BTRFS_SUPER_INFO_SIZE); block_group_cache = &info->block_group_cache; ret = find_first_extent_bit(block_group_cache, bytenr, &start, &end, BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | BLOCK_GROUP_SYSTEM); if (ret) { return NULL; } ret = get_state_private(block_group_cache, start, &ptr); if (ret) return NULL; block_group = (struct btrfs_block_group_cache *)(unsigned long)ptr; if (block_group->key.objectid <= bytenr && bytenr < block_group->key.objectid + block_group->key.offset) return block_group; return NULL; } static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) { return (cache->flags & bits) == bits; } static int noinline find_search_start(struct btrfs_root *root, struct btrfs_block_group_cache **cache_ret, u64 *start_ret, u64 num, int data) { int ret; struct btrfs_block_group_cache *cache = *cache_ret; struct extent_io_tree *free_space_cache; struct extent_state *state; u64 last; u64 start = 0; u64 cache_miss = 0; u64 total_fs_bytes; u64 search_start = *start_ret; int wrapped = 0; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); total_fs_bytes = btrfs_super_total_bytes(&root->fs_info->super_copy); free_space_cache = &root->fs_info->free_space_cache; if (!cache) goto out; again: ret = cache_block_group(root, cache); if (ret) { goto out; } last = max(search_start, cache->key.objectid); if (!block_group_bits(cache, data) || cache->ro) goto new_group; spin_lock_irq(&free_space_cache->lock); state = find_first_extent_bit_state(free_space_cache, last, EXTENT_DIRTY); while(1) { if (!state) { if (!cache_miss) cache_miss = last; spin_unlock_irq(&free_space_cache->lock); goto new_group; } start = max(last, state->start); last = state->end + 1; if (last - start < num) { do { state = extent_state_next(state); } while(state && !(state->state & EXTENT_DIRTY)); continue; } spin_unlock_irq(&free_space_cache->lock); if (cache->ro) { goto new_group; } if (start + num > cache->key.objectid + cache->key.offset) goto new_group; if (!block_group_bits(cache, data)) { printk("block group bits don't match %Lu %d\n", cache->flags, data); } *start_ret = start; return 0; } out: cache = btrfs_lookup_block_group(root->fs_info, search_start); if (!cache) { printk("Unable to find block group for %Lu\n", search_start); WARN_ON(1); } return -ENOSPC; new_group: last = cache->key.objectid + cache->key.offset; wrapped: cache = btrfs_lookup_first_block_group(root->fs_info, last); if (!cache || cache->key.objectid >= total_fs_bytes) { no_cache: if (!wrapped) { wrapped = 1; last = search_start; goto wrapped; } goto out; } if (cache_miss && !cache->cached) { cache_block_group(root, cache); last = cache_miss; cache = btrfs_lookup_first_block_group(root->fs_info, last); } cache_miss = 0; cache = btrfs_find_block_group(root, cache, last, data, 0); if (!cache) goto no_cache; *cache_ret = cache; goto again; } static u64 div_factor(u64 num, int factor) { if (factor == 10) return num; num *= factor; do_div(num, 10); return num; } static int block_group_state_bits(u64 flags) { int bits = 0; if (flags & BTRFS_BLOCK_GROUP_DATA) bits |= BLOCK_GROUP_DATA; if (flags & BTRFS_BLOCK_GROUP_METADATA) bits |= BLOCK_GROUP_METADATA; if (flags & BTRFS_BLOCK_GROUP_SYSTEM) bits |= BLOCK_GROUP_SYSTEM; return bits; } static struct btrfs_block_group_cache * __btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *hint, u64 search_start, int data, int owner) { struct btrfs_block_group_cache *cache; struct extent_io_tree *block_group_cache; struct btrfs_block_group_cache *found_group = NULL; struct btrfs_fs_info *info = root->fs_info; u64 used; u64 last = 0; u64 start; u64 end; u64 free_check; u64 ptr; int bit; int ret; int full_search = 0; int factor = 10; int wrapped = 0; block_group_cache = &info->block_group_cache; if (data & BTRFS_BLOCK_GROUP_METADATA) factor = 9; bit = block_group_state_bits(data); if (search_start) { struct btrfs_block_group_cache *shint; shint = btrfs_lookup_first_block_group(info, search_start); if (shint && block_group_bits(shint, data) && !shint->ro) { spin_lock(&shint->lock); used = btrfs_block_group_used(&shint->item); if (used + shint->pinned < div_factor(shint->key.offset, factor)) { spin_unlock(&shint->lock); return shint; } spin_unlock(&shint->lock); } } if (hint && !hint->ro && block_group_bits(hint, data)) { spin_lock(&hint->lock); used = btrfs_block_group_used(&hint->item); if (used + hint->pinned < div_factor(hint->key.offset, factor)) { spin_unlock(&hint->lock); return hint; } spin_unlock(&hint->lock); last = hint->key.objectid + hint->key.offset; } else { if (hint) last = max(hint->key.objectid, search_start); else last = search_start; } again: while(1) { ret = find_first_extent_bit(block_group_cache, last, &start, &end, bit); if (ret) break; ret = get_state_private(block_group_cache, start, &ptr); if (ret) { last = end + 1; continue; } cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; spin_lock(&cache->lock); last = cache->key.objectid + cache->key.offset; used = btrfs_block_group_used(&cache->item); if (!cache->ro && block_group_bits(cache, data)) { free_check = div_factor(cache->key.offset, factor); if (used + cache->pinned < free_check) { found_group = cache; spin_unlock(&cache->lock); goto found; } } spin_unlock(&cache->lock); cond_resched(); } if (!wrapped) { last = search_start; wrapped = 1; goto again; } if (!full_search && factor < 10) { last = search_start; full_search = 1; factor = 10; goto again; } found: return found_group; } struct btrfs_block_group_cache *btrfs_find_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *hint, u64 search_start, int data, int owner) { struct btrfs_block_group_cache *ret; ret = __btrfs_find_block_group(root, hint, search_start, data, owner); return ret; } static u64 hash_extent_ref(u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset) { u32 high_crc = ~(u32)0; u32 low_crc = ~(u32)0; __le64 lenum; lenum = cpu_to_le64(root_objectid); high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(ref_generation); low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); if (owner >= BTRFS_FIRST_FREE_OBJECTID) { lenum = cpu_to_le64(owner); low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(owner_offset); low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); } return ((u64)high_crc << 32) | (u64)low_crc; } static int match_extent_ref(struct extent_buffer *leaf, struct btrfs_extent_ref *disk_ref, struct btrfs_extent_ref *cpu_ref) { int ret; int len; if (cpu_ref->objectid) len = sizeof(*cpu_ref); else len = 2 * sizeof(u64); ret = memcmp_extent_buffer(leaf, cpu_ref, (unsigned long)disk_ref, len); return ret == 0; } static int noinline lookup_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset, int del) { u64 hash; struct btrfs_key key; struct btrfs_key found_key; struct btrfs_extent_ref ref; struct extent_buffer *leaf; struct btrfs_extent_ref *disk_ref; int ret; int ret2; btrfs_set_stack_ref_root(&ref, root_objectid); btrfs_set_stack_ref_generation(&ref, ref_generation); btrfs_set_stack_ref_objectid(&ref, owner); btrfs_set_stack_ref_offset(&ref, owner_offset); hash = hash_extent_ref(root_objectid, ref_generation, owner, owner_offset); key.offset = hash; key.objectid = bytenr; key.type = BTRFS_EXTENT_REF_KEY; while (1) { ret = btrfs_search_slot(trans, root, &key, path, del ? -1 : 0, del); if (ret < 0) goto out; leaf = path->nodes[0]; if (ret != 0) { u32 nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret2 = btrfs_next_leaf(root, path); if (ret2) goto out; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != bytenr || found_key.type != BTRFS_EXTENT_REF_KEY) goto out; key.offset = found_key.offset; if (del) { btrfs_release_path(root, path); continue; } } disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_ref); if (match_extent_ref(path->nodes[0], disk_ref, &ref)) { ret = 0; goto out; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); key.offset = found_key.offset + 1; btrfs_release_path(root, path); } out: return ret; } /* * Back reference rules. Back refs have three main goals: * * 1) differentiate between all holders of references to an extent so that * when a reference is dropped we can make sure it was a valid reference * before freeing the extent. * * 2) Provide enough information to quickly find the holders of an extent * if we notice a given block is corrupted or bad. * * 3) Make it easy to migrate blocks for FS shrinking or storage pool * maintenance. This is actually the same as #2, but with a slightly * different use case. * * File extents can be referenced by: * * - multiple snapshots, subvolumes, or different generations in one subvol * - different files inside a single subvolume (in theory, not implemented yet) * - different offsets inside a file (bookend extents in file.c) * * The extent ref structure has fields for: * * - Objectid of the subvolume root * - Generation number of the tree holding the reference * - objectid of the file holding the reference * - offset in the file corresponding to the key holding the reference * * When a file extent is allocated the fields are filled in: * (root_key.objectid, trans->transid, inode objectid, offset in file) * * When a leaf is cow'd new references are added for every file extent found * in the leaf. It looks the same as the create case, but trans->transid * will be different when the block is cow'd. * * (root_key.objectid, trans->transid, inode objectid, offset in file) * * When a file extent is removed either during snapshot deletion or file * truncation, the corresponding back reference is found * by searching for: * * (btrfs_header_owner(leaf), btrfs_header_generation(leaf), * inode objectid, offset in file) * * Btree extents can be referenced by: * * - Different subvolumes * - Different generations of the same subvolume * * Storing sufficient information for a full reverse mapping of a btree * block would require storing the lowest key of the block in the backref, * and it would require updating that lowest key either before write out or * every time it changed. Instead, the objectid of the lowest key is stored * along with the level of the tree block. This provides a hint * about where in the btree the block can be found. Searches through the * btree only need to look for a pointer to that block, so they stop one * level higher than the level recorded in the backref. * * Some btrees do not do reference counting on their extents. These * include the extent tree and the tree of tree roots. Backrefs for these * trees always have a generation of zero. * * When a tree block is created, back references are inserted: * * (root->root_key.objectid, trans->transid or zero, level, lowest_key_objectid) * * When a tree block is cow'd in a reference counted root, * new back references are added for all the blocks it points to. * These are of the form (trans->transid will have increased since creation): * * (root->root_key.objectid, trans->transid, level, lowest_key_objectid) * * Because the lowest_key_objectid and the level are just hints * they are not used when backrefs are deleted. When a backref is deleted: * * if backref was for a tree root: * root_objectid = root->root_key.objectid * else * root_objectid = btrfs_header_owner(parent) * * (root_objectid, btrfs_header_generation(parent) or zero, 0, 0) * * Back Reference Key hashing: * * Back references have four fields, each 64 bits long. Unfortunately, * This is hashed into a single 64 bit number and placed into the key offset. * The key objectid corresponds to the first byte in the extent, and the * key type is set to BTRFS_EXTENT_REF_KEY */ int btrfs_insert_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset) { u64 hash; struct btrfs_key key; struct btrfs_extent_ref ref; struct btrfs_extent_ref *disk_ref; int ret; btrfs_set_stack_ref_root(&ref, root_objectid); btrfs_set_stack_ref_generation(&ref, ref_generation); btrfs_set_stack_ref_objectid(&ref, owner); btrfs_set_stack_ref_offset(&ref, owner_offset); hash = hash_extent_ref(root_objectid, ref_generation, owner, owner_offset); key.offset = hash; key.objectid = bytenr; key.type = BTRFS_EXTENT_REF_KEY; ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref)); while (ret == -EEXIST) { disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_ref); if (match_extent_ref(path->nodes[0], disk_ref, &ref)) goto out; key.offset++; btrfs_release_path(root, path); ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(ref)); } if (ret) goto out; disk_ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_ref); write_extent_buffer(path->nodes[0], &ref, (unsigned long)disk_ref, sizeof(ref)); btrfs_mark_buffer_dirty(path->nodes[0]); out: btrfs_release_path(root, path); return ret; } static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset) { struct btrfs_path *path; int ret; struct btrfs_key key; struct extent_buffer *l; struct btrfs_extent_item *item; u32 refs; WARN_ON(num_bytes < root->sectorsize); path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 1; key.objectid = bytenr; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); key.offset = num_bytes; ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, 0, 1); if (ret < 0) return ret; if (ret != 0) { BUG(); } BUG_ON(ret != 0); l = path->nodes[0]; item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(l, item); btrfs_set_extent_refs(l, item, refs + 1); btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_release_path(root->fs_info->extent_root, path); path->reada = 1; ret = btrfs_insert_extent_backref(trans, root->fs_info->extent_root, path, bytenr, root_objectid, ref_generation, owner, owner_offset); BUG_ON(ret); finish_current_insert(trans, root->fs_info->extent_root); del_pending_extents(trans, root->fs_info->extent_root); btrfs_free_path(path); return 0; } int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset) { int ret; mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_inc_extent_ref(trans, root, bytenr, num_bytes, root_objectid, ref_generation, owner, owner_offset); mutex_unlock(&root->fs_info->alloc_mutex); return ret; } int btrfs_extent_post_op(struct btrfs_trans_handle *trans, struct btrfs_root *root) { finish_current_insert(trans, root->fs_info->extent_root); del_pending_extents(trans, root->fs_info->extent_root); return 0; } static int lookup_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u32 *refs) { struct btrfs_path *path; int ret; struct btrfs_key key; struct extent_buffer *l; struct btrfs_extent_item *item; WARN_ON(num_bytes < root->sectorsize); path = btrfs_alloc_path(); path->reada = 1; key.objectid = bytenr; key.offset = num_bytes; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, 0, 0); if (ret < 0) goto out; if (ret != 0) { btrfs_print_leaf(root, path->nodes[0]); printk("failed to find block number %Lu\n", bytenr); BUG(); } l = path->nodes[0]; item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); *refs = btrfs_extent_refs(l, item); out: btrfs_free_path(path); return 0; } u32 btrfs_count_snapshots_in_path(struct btrfs_root *root, struct btrfs_path *count_path, u64 expected_owner, u64 first_extent) { struct btrfs_root *extent_root = root->fs_info->extent_root; struct btrfs_path *path; u64 bytenr; u64 found_objectid; u64 found_owner; u64 root_objectid = root->root_key.objectid; u32 total_count = 0; u32 extent_refs; u32 cur_count; u32 nritems; int ret; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *l; struct btrfs_extent_item *item; struct btrfs_extent_ref *ref_item; int level = -1; /* FIXME, needs locking */ BUG(); mutex_lock(&root->fs_info->alloc_mutex); path = btrfs_alloc_path(); again: if (level == -1) bytenr = first_extent; else bytenr = count_path->nodes[level]->start; cur_count = 0; key.objectid = bytenr; key.offset = 0; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(ret == 0); l = path->nodes[0]; btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); if (found_key.objectid != bytenr || found_key.type != BTRFS_EXTENT_ITEM_KEY) { goto out; } item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_item); extent_refs = btrfs_extent_refs(l, item); while (1) { l = path->nodes[0]; nritems = btrfs_header_nritems(l); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(extent_root, path); if (ret == 0) continue; break; } btrfs_item_key_to_cpu(l, &found_key, path->slots[0]); if (found_key.objectid != bytenr) break; if (found_key.type != BTRFS_EXTENT_REF_KEY) { path->slots[0]++; continue; } cur_count++; ref_item = btrfs_item_ptr(l, path->slots[0], struct btrfs_extent_ref); found_objectid = btrfs_ref_root(l, ref_item); if (found_objectid != root_objectid) { total_count = 2; goto out; } if (level == -1) { found_owner = btrfs_ref_objectid(l, ref_item); if (found_owner != expected_owner) { total_count = 2; goto out; } /* * nasty. we don't count a reference held by * the running transaction. This allows nodatacow * to avoid cow most of the time */ if (found_owner >= BTRFS_FIRST_FREE_OBJECTID && btrfs_ref_generation(l, ref_item) == root->fs_info->generation) { extent_refs--; } } total_count = 1; path->slots[0]++; } /* * if there is more than one reference against a data extent, * we have to assume the other ref is another snapshot */ if (level == -1 && extent_refs > 1) { total_count = 2; goto out; } if (cur_count == 0) { total_count = 0; goto out; } if (level >= 0 && root->node == count_path->nodes[level]) goto out; level++; btrfs_release_path(root, path); goto again; out: btrfs_free_path(path); mutex_unlock(&root->fs_info->alloc_mutex); return total_count; } int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int cache_ref) { u64 bytenr; u32 nritems; struct btrfs_key key; struct btrfs_file_extent_item *fi; int i; int level; int ret; int faili; int nr_file_extents = 0; if (!root->ref_cows) return 0; level = btrfs_header_level(buf); nritems = btrfs_header_nritems(buf); for (i = 0; i < nritems; i++) { cond_resched(); if (level == 0) { u64 disk_bytenr; btrfs_item_key_to_cpu(buf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (disk_bytenr == 0) continue; if (buf != root->commit_root) nr_file_extents++; mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_inc_extent_ref(trans, root, disk_bytenr, btrfs_file_extent_disk_num_bytes(buf, fi), root->root_key.objectid, trans->transid, key.objectid, key.offset); mutex_unlock(&root->fs_info->alloc_mutex); if (ret) { faili = i; WARN_ON(1); goto fail; } } else { bytenr = btrfs_node_blockptr(buf, i); btrfs_node_key_to_cpu(buf, &key, i); mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_inc_extent_ref(trans, root, bytenr, btrfs_level_size(root, level - 1), root->root_key.objectid, trans->transid, level - 1, key.objectid); mutex_unlock(&root->fs_info->alloc_mutex); if (ret) { faili = i; WARN_ON(1); goto fail; } } } /* cache orignal leaf block's references */ if (level == 0 && cache_ref && buf != root->commit_root) { struct btrfs_leaf_ref *ref; struct btrfs_extent_info *info; ref = btrfs_alloc_leaf_ref(nr_file_extents); if (!ref) { WARN_ON(1); goto out; } btrfs_item_key_to_cpu(buf, &ref->key, 0); ref->bytenr = buf->start; ref->owner = btrfs_header_owner(buf); ref->generation = btrfs_header_generation(buf); ref->nritems = nr_file_extents; info = ref->extents; for (i = 0; nr_file_extents > 0 && i < nritems; i++) { u64 disk_bytenr; btrfs_item_key_to_cpu(buf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (disk_bytenr == 0) continue; info->bytenr = disk_bytenr; info->num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); info->objectid = key.objectid; info->offset = key.offset; info++; } BUG_ON(!root->ref_tree); ret = btrfs_add_leaf_ref(root, ref); WARN_ON(ret); btrfs_free_leaf_ref(ref); } out: return 0; fail: WARN_ON(1); #if 0 for (i =0; i < faili; i++) { if (level == 0) { u64 disk_bytenr; btrfs_item_key_to_cpu(buf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (disk_bytenr == 0) continue; err = btrfs_free_extent(trans, root, disk_bytenr, btrfs_file_extent_disk_num_bytes(buf, fi), 0); BUG_ON(err); } else { bytenr = btrfs_node_blockptr(buf, i); err = btrfs_free_extent(trans, root, bytenr, btrfs_level_size(root, level - 1), 0); BUG_ON(err); } } #endif return ret; } static int write_one_cache_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_block_group_cache *cache) { int ret; int pending_ret; struct btrfs_root *extent_root = root->fs_info->extent_root; unsigned long bi; struct extent_buffer *leaf; ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); if (ret < 0) goto fail; BUG_ON(ret); leaf = path->nodes[0]; bi = btrfs_item_ptr_offset(leaf, path->slots[0]); write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(extent_root, path); fail: finish_current_insert(trans, extent_root); pending_ret = del_pending_extents(trans, extent_root); if (ret) return ret; if (pending_ret) return pending_ret; return 0; } int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct extent_io_tree *block_group_cache; struct btrfs_block_group_cache *cache; int ret; int err = 0; int werr = 0; struct btrfs_path *path; u64 last = 0; u64 start; u64 end; u64 ptr; block_group_cache = &root->fs_info->block_group_cache; path = btrfs_alloc_path(); if (!path) return -ENOMEM; mutex_lock(&root->fs_info->alloc_mutex); while(1) { ret = find_first_extent_bit(block_group_cache, last, &start, &end, BLOCK_GROUP_DIRTY); if (ret) break; last = end + 1; ret = get_state_private(block_group_cache, start, &ptr); if (ret) break; cache = (struct btrfs_block_group_cache *)(unsigned long)ptr; err = write_one_cache_group(trans, root, path, cache); /* * if we fail to write the cache group, we want * to keep it marked dirty in hopes that a later * write will work */ if (err) { werr = err; continue; } clear_extent_bits(block_group_cache, start, end, BLOCK_GROUP_DIRTY, GFP_NOFS); } btrfs_free_path(path); mutex_unlock(&root->fs_info->alloc_mutex); return werr; } static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, u64 flags) { struct list_head *head = &info->space_info; struct list_head *cur; struct btrfs_space_info *found; list_for_each(cur, head) { found = list_entry(cur, struct btrfs_space_info, list); if (found->flags == flags) return found; } return NULL; } static int update_space_info(struct btrfs_fs_info *info, u64 flags, u64 total_bytes, u64 bytes_used, struct btrfs_space_info **space_info) { struct btrfs_space_info *found; found = __find_space_info(info, flags); if (found) { found->total_bytes += total_bytes; found->bytes_used += bytes_used; found->full = 0; WARN_ON(found->total_bytes < found->bytes_used); *space_info = found; return 0; } found = kmalloc(sizeof(*found), GFP_NOFS); if (!found) return -ENOMEM; list_add(&found->list, &info->space_info); found->flags = flags; found->total_bytes = total_bytes; found->bytes_used = bytes_used; found->bytes_pinned = 0; found->full = 0; found->force_alloc = 0; *space_info = found; return 0; } static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) { u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_DUP); if (extra_flags) { if (flags & BTRFS_BLOCK_GROUP_DATA) fs_info->avail_data_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_METADATA) fs_info->avail_metadata_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_SYSTEM) fs_info->avail_system_alloc_bits |= extra_flags; } } static u64 reduce_alloc_profile(struct btrfs_root *root, u64 flags) { u64 num_devices = root->fs_info->fs_devices->num_devices; if (num_devices == 1) flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); if (num_devices < 4) flags &= ~BTRFS_BLOCK_GROUP_RAID10; if ((flags & BTRFS_BLOCK_GROUP_DUP) && (flags & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))) { flags &= ~BTRFS_BLOCK_GROUP_DUP; } if ((flags & BTRFS_BLOCK_GROUP_RAID1) && (flags & BTRFS_BLOCK_GROUP_RAID10)) { flags &= ~BTRFS_BLOCK_GROUP_RAID1; } if ((flags & BTRFS_BLOCK_GROUP_RAID0) && ((flags & BTRFS_BLOCK_GROUP_RAID1) | (flags & BTRFS_BLOCK_GROUP_RAID10) | (flags & BTRFS_BLOCK_GROUP_DUP))) flags &= ~BTRFS_BLOCK_GROUP_RAID0; return flags; } static int do_chunk_alloc(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, u64 alloc_bytes, u64 flags, int force) { struct btrfs_space_info *space_info; u64 thresh; u64 start; u64 num_bytes; int ret; flags = reduce_alloc_profile(extent_root, flags); space_info = __find_space_info(extent_root->fs_info, flags); if (!space_info) { ret = update_space_info(extent_root->fs_info, flags, 0, 0, &space_info); BUG_ON(ret); } BUG_ON(!space_info); if (space_info->force_alloc) { force = 1; space_info->force_alloc = 0; } if (space_info->full) goto out; thresh = div_factor(space_info->total_bytes, 6); if (!force && (space_info->bytes_used + space_info->bytes_pinned + alloc_bytes) < thresh) goto out; mutex_lock(&extent_root->fs_info->chunk_mutex); ret = btrfs_alloc_chunk(trans, extent_root, &start, &num_bytes, flags); if (ret == -ENOSPC) { printk("space info full %Lu\n", flags); space_info->full = 1; goto out_unlock; } BUG_ON(ret); ret = btrfs_make_block_group(trans, extent_root, 0, flags, BTRFS_FIRST_CHUNK_TREE_OBJECTID, start, num_bytes); BUG_ON(ret); out_unlock: mutex_unlock(&extent_root->fs_info->chunk_mutex); out: return 0; } static int update_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, int alloc, int mark_free) { struct btrfs_block_group_cache *cache; struct btrfs_fs_info *info = root->fs_info; u64 total = num_bytes; u64 old_val; u64 byte_in_group; u64 start; u64 end; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); while(total) { cache = btrfs_lookup_block_group(info, bytenr); if (!cache) { return -1; } byte_in_group = bytenr - cache->key.objectid; WARN_ON(byte_in_group > cache->key.offset); start = cache->key.objectid; end = start + cache->key.offset - 1; set_extent_bits(&info->block_group_cache, start, end, BLOCK_GROUP_DIRTY, GFP_NOFS); spin_lock(&cache->lock); old_val = btrfs_block_group_used(&cache->item); num_bytes = min(total, cache->key.offset - byte_in_group); if (alloc) { old_val += num_bytes; cache->space_info->bytes_used += num_bytes; btrfs_set_block_group_used(&cache->item, old_val); spin_unlock(&cache->lock); } else { old_val -= num_bytes; cache->space_info->bytes_used -= num_bytes; btrfs_set_block_group_used(&cache->item, old_val); spin_unlock(&cache->lock); if (mark_free) { set_extent_dirty(&info->free_space_cache, bytenr, bytenr + num_bytes - 1, GFP_NOFS); } } total -= num_bytes; bytenr += num_bytes; } return 0; } static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) { u64 start; u64 end; int ret; ret = find_first_extent_bit(&root->fs_info->block_group_cache, search_start, &start, &end, BLOCK_GROUP_DATA | BLOCK_GROUP_METADATA | BLOCK_GROUP_SYSTEM); if (ret) return 0; return start; } static int update_pinned_extents(struct btrfs_root *root, u64 bytenr, u64 num, int pin) { u64 len; struct btrfs_block_group_cache *cache; struct btrfs_fs_info *fs_info = root->fs_info; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); if (pin) { set_extent_dirty(&fs_info->pinned_extents, bytenr, bytenr + num - 1, GFP_NOFS); } else { clear_extent_dirty(&fs_info->pinned_extents, bytenr, bytenr + num - 1, GFP_NOFS); } while (num > 0) { cache = btrfs_lookup_block_group(fs_info, bytenr); if (!cache) { u64 first = first_logical_byte(root, bytenr); WARN_ON(first < bytenr); len = min(first - bytenr, num); } else { len = min(num, cache->key.offset - (bytenr - cache->key.objectid)); } if (pin) { if (cache) { spin_lock(&cache->lock); cache->pinned += len; cache->space_info->bytes_pinned += len; spin_unlock(&cache->lock); } fs_info->total_pinned += len; } else { if (cache) { spin_lock(&cache->lock); cache->pinned -= len; cache->space_info->bytes_pinned -= len; spin_unlock(&cache->lock); } fs_info->total_pinned -= len; } bytenr += len; num -= len; } return 0; } int btrfs_copy_pinned(struct btrfs_root *root, struct extent_io_tree *copy) { u64 last = 0; u64 start; u64 end; struct extent_io_tree *pinned_extents = &root->fs_info->pinned_extents; int ret; while(1) { ret = find_first_extent_bit(pinned_extents, last, &start, &end, EXTENT_DIRTY); if (ret) break; set_extent_dirty(copy, start, end, GFP_NOFS); last = end + 1; } return 0; } int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_io_tree *unpin) { u64 start; u64 end; int ret; struct extent_io_tree *free_space_cache; free_space_cache = &root->fs_info->free_space_cache; mutex_lock(&root->fs_info->alloc_mutex); while(1) { ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY); if (ret) break; update_pinned_extents(root, start, end + 1 - start, 0); clear_extent_dirty(unpin, start, end, GFP_NOFS); set_extent_dirty(free_space_cache, start, end, GFP_NOFS); if (need_resched()) { mutex_unlock(&root->fs_info->alloc_mutex); cond_resched(); mutex_lock(&root->fs_info->alloc_mutex); } } mutex_unlock(&root->fs_info->alloc_mutex); return 0; } static int finish_current_insert(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root) { u64 start; u64 end; struct btrfs_fs_info *info = extent_root->fs_info; struct extent_buffer *eb; struct btrfs_path *path; struct btrfs_key ins; struct btrfs_disk_key first; struct btrfs_extent_item extent_item; int ret; int level; int err = 0; WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); btrfs_set_stack_extent_refs(&extent_item, 1); btrfs_set_key_type(&ins, BTRFS_EXTENT_ITEM_KEY); path = btrfs_alloc_path(); while(1) { ret = find_first_extent_bit(&info->extent_ins, 0, &start, &end, EXTENT_LOCKED); if (ret) break; ins.objectid = start; ins.offset = end + 1 - start; err = btrfs_insert_item(trans, extent_root, &ins, &extent_item, sizeof(extent_item)); clear_extent_bits(&info->extent_ins, start, end, EXTENT_LOCKED, GFP_NOFS); eb = btrfs_find_tree_block(extent_root, ins.objectid, ins.offset); if (!btrfs_buffer_uptodate(eb, trans->transid)) { mutex_unlock(&extent_root->fs_info->alloc_mutex); btrfs_read_buffer(eb, trans->transid); mutex_lock(&extent_root->fs_info->alloc_mutex); } btrfs_tree_lock(eb); level = btrfs_header_level(eb); if (level == 0) { btrfs_item_key(eb, &first, 0); } else { btrfs_node_key(eb, &first, 0); } btrfs_tree_unlock(eb); free_extent_buffer(eb); /* * the first key is just a hint, so the race we've created * against reading it is fine */ err = btrfs_insert_extent_backref(trans, extent_root, path, start, extent_root->root_key.objectid, 0, level, btrfs_disk_key_objectid(&first)); BUG_ON(err); if (need_resched()) { mutex_unlock(&extent_root->fs_info->alloc_mutex); cond_resched(); mutex_lock(&extent_root->fs_info->alloc_mutex); } } btrfs_free_path(path); return 0; } static int pin_down_bytes(struct btrfs_root *root, u64 bytenr, u32 num_bytes, int pending) { int err = 0; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); if (!pending) { struct extent_buffer *buf; buf = btrfs_find_tree_block(root, bytenr, num_bytes); if (buf) { if (btrfs_buffer_uptodate(buf, 0) && btrfs_try_tree_lock(buf)) { u64 transid = root->fs_info->running_transaction->transid; u64 header_transid = btrfs_header_generation(buf); if (header_transid == transid && !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { clean_tree_block(NULL, root, buf); btrfs_tree_unlock(buf); free_extent_buffer(buf); return 1; } btrfs_tree_unlock(buf); } free_extent_buffer(buf); } update_pinned_extents(root, bytenr, num_bytes, 1); } else { set_extent_bits(&root->fs_info->pending_del, bytenr, bytenr + num_bytes - 1, EXTENT_LOCKED, GFP_NOFS); } BUG_ON(err < 0); return 0; } /* * remove an extent from the root, returns 0 on success */ static int __free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 root_objectid, u64 ref_generation, u64 owner_objectid, u64 owner_offset, int pin, int mark_free) { struct btrfs_path *path; struct btrfs_key key; struct btrfs_fs_info *info = root->fs_info; struct btrfs_root *extent_root = info->extent_root; struct extent_buffer *leaf; int ret; int extent_slot = 0; int found_extent = 0; int num_to_del = 1; struct btrfs_extent_item *ei; u32 refs; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); key.objectid = bytenr; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); key.offset = num_bytes; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 1; ret = lookup_extent_backref(trans, extent_root, path, bytenr, root_objectid, ref_generation, owner_objectid, owner_offset, 1); if (ret == 0) { struct btrfs_key found_key; extent_slot = path->slots[0]; while(extent_slot > 0) { extent_slot--; btrfs_item_key_to_cpu(path->nodes[0], &found_key, extent_slot); if (found_key.objectid != bytenr) break; if (found_key.type == BTRFS_EXTENT_ITEM_KEY && found_key.offset == num_bytes) { found_extent = 1; break; } if (path->slots[0] - extent_slot > 5) break; } if (!found_extent) ret = btrfs_del_item(trans, extent_root, path); } else { btrfs_print_leaf(extent_root, path->nodes[0]); WARN_ON(1); printk("Unable to find ref byte nr %Lu root %Lu " " gen %Lu owner %Lu offset %Lu\n", bytenr, root_objectid, ref_generation, owner_objectid, owner_offset); } if (!found_extent) { btrfs_release_path(extent_root, path); ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); if (ret < 0) return ret; BUG_ON(ret); extent_slot = path->slots[0]; } leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, ei); BUG_ON(refs == 0); refs -= 1; btrfs_set_extent_refs(leaf, ei, refs); btrfs_mark_buffer_dirty(leaf); if (refs == 0 && found_extent && path->slots[0] == extent_slot + 1) { /* if the back ref and the extent are next to each other * they get deleted below in one shot */ path->slots[0] = extent_slot; num_to_del = 2; } else if (found_extent) { /* otherwise delete the extent back ref */ ret = btrfs_del_item(trans, extent_root, path); BUG_ON(ret); /* if refs are 0, we need to setup the path for deletion */ if (refs == 0) { btrfs_release_path(extent_root, path); ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); if (ret < 0) return ret; BUG_ON(ret); } } if (refs == 0) { u64 super_used; u64 root_used; if (pin) { ret = pin_down_bytes(root, bytenr, num_bytes, 0); if (ret > 0) mark_free = 1; BUG_ON(ret < 0); } /* block accounting for super block */ spin_lock_irq(&info->delalloc_lock); super_used = btrfs_super_bytes_used(&info->super_copy); btrfs_set_super_bytes_used(&info->super_copy, super_used - num_bytes); spin_unlock_irq(&info->delalloc_lock); /* block accounting for root item */ root_used = btrfs_root_used(&root->root_item); btrfs_set_root_used(&root->root_item, root_used - num_bytes); ret = btrfs_del_items(trans, extent_root, path, path->slots[0], num_to_del); if (ret) { return ret; } ret = update_block_group(trans, root, bytenr, num_bytes, 0, mark_free); BUG_ON(ret); } btrfs_free_path(path); finish_current_insert(trans, extent_root); return ret; } /* * find all the blocks marked as pending in the radix tree and remove * them from the extent map */ static int del_pending_extents(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root) { int ret; int err = 0; u64 start; u64 end; struct extent_io_tree *pending_del; struct extent_io_tree *pinned_extents; WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); pending_del = &extent_root->fs_info->pending_del; pinned_extents = &extent_root->fs_info->pinned_extents; while(1) { ret = find_first_extent_bit(pending_del, 0, &start, &end, EXTENT_LOCKED); if (ret) break; clear_extent_bits(pending_del, start, end, EXTENT_LOCKED, GFP_NOFS); if (!test_range_bit(&extent_root->fs_info->extent_ins, start, end, EXTENT_LOCKED, 0)) { update_pinned_extents(extent_root, start, end + 1 - start, 1); ret = __free_extent(trans, extent_root, start, end + 1 - start, extent_root->root_key.objectid, 0, 0, 0, 0, 0); } else { clear_extent_bits(&extent_root->fs_info->extent_ins, start, end, EXTENT_LOCKED, GFP_NOFS); } if (ret) err = ret; if (need_resched()) { mutex_unlock(&extent_root->fs_info->alloc_mutex); cond_resched(); mutex_lock(&extent_root->fs_info->alloc_mutex); } } return err; } /* * remove an extent from the root, returns 0 on success */ static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 root_objectid, u64 ref_generation, u64 owner_objectid, u64 owner_offset, int pin) { struct btrfs_root *extent_root = root->fs_info->extent_root; int pending_ret; int ret; WARN_ON(num_bytes < root->sectorsize); if (!root->ref_cows) ref_generation = 0; if (root == extent_root) { pin_down_bytes(root, bytenr, num_bytes, 1); return 0; } ret = __free_extent(trans, root, bytenr, num_bytes, root_objectid, ref_generation, owner_objectid, owner_offset, pin, pin == 0); finish_current_insert(trans, root->fs_info->extent_root); pending_ret = del_pending_extents(trans, root->fs_info->extent_root); return ret ? ret : pending_ret; } int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 root_objectid, u64 ref_generation, u64 owner_objectid, u64 owner_offset, int pin) { int ret; maybe_lock_mutex(root); ret = __btrfs_free_extent(trans, root, bytenr, num_bytes, root_objectid, ref_generation, owner_objectid, owner_offset, pin); maybe_unlock_mutex(root); return ret; } static u64 stripe_align(struct btrfs_root *root, u64 val) { u64 mask = ((u64)root->stripesize - 1); u64 ret = (val + mask) & ~mask; return ret; } /* * walks the btree of allocated extents and find a hole of a given size. * The key ins is changed to record the hole: * ins->objectid == block start * ins->flags = BTRFS_EXTENT_ITEM_KEY * ins->offset == number of blocks * Any available blocks before search_start are skipped. */ static int noinline find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *orig_root, u64 num_bytes, u64 empty_size, u64 search_start, u64 search_end, u64 hint_byte, struct btrfs_key *ins, u64 exclude_start, u64 exclude_nr, int data) { int ret; u64 orig_search_start; struct btrfs_root * root = orig_root->fs_info->extent_root; struct btrfs_fs_info *info = root->fs_info; u64 total_needed = num_bytes; u64 *last_ptr = NULL; struct btrfs_block_group_cache *block_group; int full_scan = 0; int wrapped = 0; int chunk_alloc_done = 0; int empty_cluster = 2 * 1024 * 1024; int allowed_chunk_alloc = 0; WARN_ON(num_bytes < root->sectorsize); btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); if (orig_root->ref_cows || empty_size) allowed_chunk_alloc = 1; if (data & BTRFS_BLOCK_GROUP_METADATA) { last_ptr = &root->fs_info->last_alloc; empty_cluster = 256 * 1024; } if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) { last_ptr = &root->fs_info->last_data_alloc; } if (last_ptr) { if (*last_ptr) hint_byte = *last_ptr; else { empty_size += empty_cluster; } } search_start = max(search_start, first_logical_byte(root, 0)); orig_search_start = search_start; if (search_end == (u64)-1) search_end = btrfs_super_total_bytes(&info->super_copy); if (hint_byte) { block_group = btrfs_lookup_first_block_group(info, hint_byte); if (!block_group) hint_byte = search_start; block_group = btrfs_find_block_group(root, block_group, hint_byte, data, 1); if (last_ptr && *last_ptr == 0 && block_group) hint_byte = block_group->key.objectid; } else { block_group = btrfs_find_block_group(root, trans->block_group, search_start, data, 1); } search_start = max(search_start, hint_byte); total_needed += empty_size; check_failed: if (!block_group) { block_group = btrfs_lookup_first_block_group(info, search_start); if (!block_group) block_group = btrfs_lookup_first_block_group(info, orig_search_start); } if (full_scan && !chunk_alloc_done) { if (allowed_chunk_alloc) { do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024, data, 1); allowed_chunk_alloc = 0; } else if (block_group && block_group_bits(block_group, data)) { block_group->space_info->force_alloc = 1; } chunk_alloc_done = 1; } ret = find_search_start(root, &block_group, &search_start, total_needed, data); if (ret == -ENOSPC && last_ptr && *last_ptr) { *last_ptr = 0; block_group = btrfs_lookup_first_block_group(info, orig_search_start); search_start = orig_search_start; ret = find_search_start(root, &block_group, &search_start, total_needed, data); } if (ret == -ENOSPC) goto enospc; if (ret) goto error; if (last_ptr && *last_ptr && search_start != *last_ptr) { *last_ptr = 0; if (!empty_size) { empty_size += empty_cluster; total_needed += empty_size; } block_group = btrfs_lookup_first_block_group(info, orig_search_start); search_start = orig_search_start; ret = find_search_start(root, &block_group, &search_start, total_needed, data); if (ret == -ENOSPC) goto enospc; if (ret) goto error; } search_start = stripe_align(root, search_start); ins->objectid = search_start; ins->offset = num_bytes; if (ins->objectid + num_bytes >= search_end) goto enospc; if (ins->objectid + num_bytes > block_group->key.objectid + block_group->key.offset) { search_start = block_group->key.objectid + block_group->key.offset; goto new_group; } if (test_range_bit(&info->extent_ins, ins->objectid, ins->objectid + num_bytes -1, EXTENT_LOCKED, 0)) { search_start = ins->objectid + num_bytes; goto new_group; } if (test_range_bit(&info->pinned_extents, ins->objectid, ins->objectid + num_bytes -1, EXTENT_DIRTY, 0)) { search_start = ins->objectid + num_bytes; goto new_group; } if (exclude_nr > 0 && (ins->objectid + num_bytes > exclude_start && ins->objectid < exclude_start + exclude_nr)) { search_start = exclude_start + exclude_nr; goto new_group; } if (!(data & BTRFS_BLOCK_GROUP_DATA)) { block_group = btrfs_lookup_block_group(info, ins->objectid); if (block_group) trans->block_group = block_group; } ins->offset = num_bytes; if (last_ptr) { *last_ptr = ins->objectid + ins->offset; if (*last_ptr == btrfs_super_total_bytes(&root->fs_info->super_copy)) { *last_ptr = 0; } } return 0; new_group: if (search_start + num_bytes >= search_end) { enospc: search_start = orig_search_start; if (full_scan) { ret = -ENOSPC; goto error; } if (wrapped) { if (!full_scan) total_needed -= empty_size; full_scan = 1; } else wrapped = 1; } block_group = btrfs_lookup_first_block_group(info, search_start); cond_resched(); block_group = btrfs_find_block_group(root, block_group, search_start, data, 0); goto check_failed; error: return ret; } static int __btrfs_reserve_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 min_alloc_size, u64 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins, u64 data) { int ret; u64 search_start = 0; u64 alloc_profile; struct btrfs_fs_info *info = root->fs_info; if (data) { alloc_profile = info->avail_data_alloc_bits & info->data_alloc_profile; data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; } else if (root == root->fs_info->chunk_root) { alloc_profile = info->avail_system_alloc_bits & info->system_alloc_profile; data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; } else { alloc_profile = info->avail_metadata_alloc_bits & info->metadata_alloc_profile; data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; } again: data = reduce_alloc_profile(root, data); /* * the only place that sets empty_size is btrfs_realloc_node, which * is not called recursively on allocations */ if (empty_size || root->ref_cows) { if (!(data & BTRFS_BLOCK_GROUP_METADATA)) { ret = do_chunk_alloc(trans, root->fs_info->extent_root, 2 * 1024 * 1024, BTRFS_BLOCK_GROUP_METADATA | (info->metadata_alloc_profile & info->avail_metadata_alloc_bits), 0); BUG_ON(ret); } ret = do_chunk_alloc(trans, root->fs_info->extent_root, num_bytes + 2 * 1024 * 1024, data, 0); BUG_ON(ret); } WARN_ON(num_bytes < root->sectorsize); ret = find_free_extent(trans, root, num_bytes, empty_size, search_start, search_end, hint_byte, ins, trans->alloc_exclude_start, trans->alloc_exclude_nr, data); if (ret == -ENOSPC && num_bytes > min_alloc_size) { num_bytes = num_bytes >> 1; num_bytes = max(num_bytes, min_alloc_size); do_chunk_alloc(trans, root->fs_info->extent_root, num_bytes, data, 1); goto again; } if (ret) { printk("allocation failed flags %Lu\n", data); BUG(); } clear_extent_dirty(&root->fs_info->free_space_cache, ins->objectid, ins->objectid + ins->offset - 1, GFP_NOFS); return 0; } int btrfs_reserve_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 min_alloc_size, u64 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins, u64 data) { int ret; maybe_lock_mutex(root); ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, empty_size, hint_byte, search_end, ins, data); maybe_unlock_mutex(root); return ret; } static int __btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset, struct btrfs_key *ins) { int ret; int pending_ret; u64 super_used; u64 root_used; u64 num_bytes = ins->offset; u32 sizes[2]; struct btrfs_fs_info *info = root->fs_info; struct btrfs_root *extent_root = info->extent_root; struct btrfs_extent_item *extent_item; struct btrfs_extent_ref *ref; struct btrfs_path *path; struct btrfs_key keys[2]; /* block accounting for super block */ spin_lock_irq(&info->delalloc_lock); super_used = btrfs_super_bytes_used(&info->super_copy); btrfs_set_super_bytes_used(&info->super_copy, super_used + num_bytes); spin_unlock_irq(&info->delalloc_lock); /* block accounting for root item */ root_used = btrfs_root_used(&root->root_item); btrfs_set_root_used(&root->root_item, root_used + num_bytes); if (root == extent_root) { set_extent_bits(&root->fs_info->extent_ins, ins->objectid, ins->objectid + ins->offset - 1, EXTENT_LOCKED, GFP_NOFS); goto update_block; } memcpy(&keys[0], ins, sizeof(*ins)); keys[1].offset = hash_extent_ref(root_objectid, ref_generation, owner, owner_offset); keys[1].objectid = ins->objectid; keys[1].type = BTRFS_EXTENT_REF_KEY; sizes[0] = sizeof(*extent_item); sizes[1] = sizeof(*ref); path = btrfs_alloc_path(); BUG_ON(!path); ret = btrfs_insert_empty_items(trans, extent_root, path, keys, sizes, 2); BUG_ON(ret); extent_item = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_item); btrfs_set_extent_refs(path->nodes[0], extent_item, 1); ref = btrfs_item_ptr(path->nodes[0], path->slots[0] + 1, struct btrfs_extent_ref); btrfs_set_ref_root(path->nodes[0], ref, root_objectid); btrfs_set_ref_generation(path->nodes[0], ref, ref_generation); btrfs_set_ref_objectid(path->nodes[0], ref, owner); btrfs_set_ref_offset(path->nodes[0], ref, owner_offset); btrfs_mark_buffer_dirty(path->nodes[0]); trans->alloc_exclude_start = 0; trans->alloc_exclude_nr = 0; btrfs_free_path(path); finish_current_insert(trans, extent_root); pending_ret = del_pending_extents(trans, extent_root); if (ret) goto out; if (pending_ret) { ret = pending_ret; goto out; } update_block: ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); if (ret) { printk("update block group failed for %Lu %Lu\n", ins->objectid, ins->offset); BUG(); } out: return ret; } int btrfs_alloc_reserved_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset, struct btrfs_key *ins) { int ret; maybe_lock_mutex(root); ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid, ref_generation, owner, owner_offset, ins); maybe_unlock_mutex(root); return ret; } /* * finds a free extent and does all the dirty work required for allocation * returns the key for the extent through ins, and a tree buffer for * the first block of the extent through buf. * * returns 0 if everything worked, non-zero otherwise. */ int btrfs_alloc_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 min_alloc_size, u64 root_objectid, u64 ref_generation, u64 owner, u64 owner_offset, u64 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins, u64 data) { int ret; maybe_lock_mutex(root); ret = __btrfs_reserve_extent(trans, root, num_bytes, min_alloc_size, empty_size, hint_byte, search_end, ins, data); BUG_ON(ret); ret = __btrfs_alloc_reserved_extent(trans, root, root_objectid, ref_generation, owner, owner_offset, ins); BUG_ON(ret); maybe_unlock_mutex(root); return ret; } /* * helper function to allocate a block for a given tree * returns the tree buffer or NULL. */ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u32 blocksize, u64 root_objectid, u64 ref_generation, u64 first_objectid, int level, u64 hint, u64 empty_size) { struct btrfs_key ins; int ret; struct extent_buffer *buf; ret = btrfs_alloc_extent(trans, root, blocksize, blocksize, root_objectid, ref_generation, level, first_objectid, empty_size, hint, (u64)-1, &ins, 0); if (ret) { BUG_ON(ret > 0); return ERR_PTR(ret); } buf = btrfs_find_create_tree_block(root, ins.objectid, blocksize); if (!buf) { btrfs_free_extent(trans, root, ins.objectid, blocksize, root->root_key.objectid, ref_generation, 0, 0, 0); return ERR_PTR(-ENOMEM); } btrfs_set_header_generation(buf, trans->transid); btrfs_tree_lock(buf); clean_tree_block(trans, root, buf); btrfs_set_buffer_uptodate(buf); if (PageDirty(buf->first_page)) { printk("page %lu dirty\n", buf->first_page->index); WARN_ON(1); } set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); trans->blocks_used++; return buf; } static int noinline drop_leaf_ref_no_cache(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *leaf) { u64 leaf_owner; u64 leaf_generation; struct btrfs_key key; struct btrfs_file_extent_item *fi; int i; int nritems; int ret; BUG_ON(!btrfs_is_leaf(leaf)); nritems = btrfs_header_nritems(leaf); leaf_owner = btrfs_header_owner(leaf); leaf_generation = btrfs_header_generation(leaf); mutex_unlock(&root->fs_info->alloc_mutex); for (i = 0; i < nritems; i++) { u64 disk_bytenr; cond_resched(); btrfs_item_key_to_cpu(leaf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; /* * FIXME make sure to insert a trans record that * repeats the snapshot del on crash */ disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); if (disk_bytenr == 0) continue; mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_free_extent(trans, root, disk_bytenr, btrfs_file_extent_disk_num_bytes(leaf, fi), leaf_owner, leaf_generation, key.objectid, key.offset, 0); mutex_unlock(&root->fs_info->alloc_mutex); BUG_ON(ret); } mutex_lock(&root->fs_info->alloc_mutex); return 0; } static int noinline drop_leaf_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_leaf_ref *ref) { int i; int ret; struct btrfs_extent_info *info = ref->extents; mutex_unlock(&root->fs_info->alloc_mutex); for (i = 0; i < ref->nritems; i++) { mutex_lock(&root->fs_info->alloc_mutex); ret = __btrfs_free_extent(trans, root, info->bytenr, info->num_bytes, ref->owner, ref->generation, info->objectid, info->offset, 0); mutex_unlock(&root->fs_info->alloc_mutex); BUG_ON(ret); info++; } mutex_lock(&root->fs_info->alloc_mutex); return 0; } static void noinline reada_walk_down(struct btrfs_root *root, struct extent_buffer *node, int slot) { u64 bytenr; u64 last = 0; u32 nritems; u32 refs; u32 blocksize; int ret; int i; int level; int skipped = 0; nritems = btrfs_header_nritems(node); level = btrfs_header_level(node); if (level) return; for (i = slot; i < nritems && skipped < 32; i++) { bytenr = btrfs_node_blockptr(node, i); if (last && ((bytenr > last && bytenr - last > 32 * 1024) || (last > bytenr && last - bytenr > 32 * 1024))) { skipped++; continue; } blocksize = btrfs_level_size(root, level - 1); if (i != slot) { ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs); BUG_ON(ret); if (refs != 1) { skipped++; continue; } } ret = readahead_tree_block(root, bytenr, blocksize, btrfs_node_ptr_generation(node, i)); last = bytenr + blocksize; cond_resched(); if (ret) break; } } /* * we want to avoid as much random IO as we can with the alloc mutex * held, so drop the lock and do the lookup, then do it again with the * lock held. */ int drop_snap_lookup_refcount(struct btrfs_root *root, u64 start, u64 len, u32 *refs) { mutex_unlock(&root->fs_info->alloc_mutex); lookup_extent_ref(NULL, root, start, len, refs); cond_resched(); mutex_lock(&root->fs_info->alloc_mutex); return lookup_extent_ref(NULL, root, start, len, refs); } /* * helper function for drop_snapshot, this walks down the tree dropping ref * counts as it goes. */ static int noinline walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int *level) { u64 root_owner; u64 root_gen; u64 bytenr; u64 ptr_gen; struct extent_buffer *next; struct extent_buffer *cur; struct extent_buffer *parent; struct btrfs_leaf_ref *ref; u32 blocksize; int ret; u32 refs; mutex_lock(&root->fs_info->alloc_mutex); WARN_ON(*level < 0); WARN_ON(*level >= BTRFS_MAX_LEVEL); ret = drop_snap_lookup_refcount(root, path->nodes[*level]->start, path->nodes[*level]->len, &refs); BUG_ON(ret); if (refs > 1) goto out; /* * walk down to the last node level and free all the leaves */ while(*level >= 0) { WARN_ON(*level < 0); WARN_ON(*level >= BTRFS_MAX_LEVEL); cur = path->nodes[*level]; if (btrfs_header_level(cur) != *level) WARN_ON(1); if (path->slots[*level] >= btrfs_header_nritems(cur)) break; if (*level == 0) { ret = drop_leaf_ref_no_cache(trans, root, cur); BUG_ON(ret); break; } bytenr = btrfs_node_blockptr(cur, path->slots[*level]); ptr_gen = btrfs_node_ptr_generation(cur, path->slots[*level]); blocksize = btrfs_level_size(root, *level - 1); ret = drop_snap_lookup_refcount(root, bytenr, blocksize, &refs); BUG_ON(ret); if (refs != 1) { parent = path->nodes[*level]; root_owner = btrfs_header_owner(parent); root_gen = btrfs_header_generation(parent); path->slots[*level]++; ret = __btrfs_free_extent(trans, root, bytenr, blocksize, root_owner, root_gen, 0, 0, 1); BUG_ON(ret); continue; } if (*level == 1) { struct btrfs_key key; btrfs_node_key_to_cpu(cur, &key, path->slots[*level]); ref = btrfs_lookup_leaf_ref(root, &key); if (ref) { ret = drop_leaf_ref(trans, root, ref); BUG_ON(ret); btrfs_remove_leaf_ref(root, ref); btrfs_free_leaf_ref(ref); *level = 0; break; } } next = btrfs_find_tree_block(root, bytenr, blocksize); if (!next || !btrfs_buffer_uptodate(next, ptr_gen)) { free_extent_buffer(next); mutex_unlock(&root->fs_info->alloc_mutex); if (path->slots[*level] == 0) reada_walk_down(root, cur, path->slots[*level]); next = read_tree_block(root, bytenr, blocksize, ptr_gen); cond_resched(); mutex_lock(&root->fs_info->alloc_mutex); /* we've dropped the lock, double check */ ret = lookup_extent_ref(NULL, root, bytenr, blocksize, &refs); BUG_ON(ret); if (refs != 1) { parent = path->nodes[*level]; root_owner = btrfs_header_owner(parent); root_gen = btrfs_header_generation(parent); path->slots[*level]++; free_extent_buffer(next); ret = __btrfs_free_extent(trans, root, bytenr, blocksize, root_owner, root_gen, 0, 0, 1); BUG_ON(ret); continue; } } WARN_ON(*level <= 0); if (path->nodes[*level-1]) free_extent_buffer(path->nodes[*level-1]); path->nodes[*level-1] = next; *level = btrfs_header_level(next); path->slots[*level] = 0; } out: WARN_ON(*level < 0); WARN_ON(*level >= BTRFS_MAX_LEVEL); if (path->nodes[*level] == root->node) { parent = path->nodes[*level]; bytenr = path->nodes[*level]->start; } else { parent = path->nodes[*level + 1]; bytenr = btrfs_node_blockptr(parent, path->slots[*level + 1]); } blocksize = btrfs_level_size(root, *level); root_owner = btrfs_header_owner(parent); root_gen = btrfs_header_generation(parent); ret = __btrfs_free_extent(trans, root, bytenr, blocksize, root_owner, root_gen, 0, 0, 1); free_extent_buffer(path->nodes[*level]); path->nodes[*level] = NULL; *level += 1; BUG_ON(ret); mutex_unlock(&root->fs_info->alloc_mutex); cond_resched(); return 0; } /* * helper for dropping snapshots. This walks back up the tree in the path * to find the first node higher up where we haven't yet gone through * all the slots */ static int noinline walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int *level) { u64 root_owner; u64 root_gen; struct btrfs_root_item *root_item = &root->root_item; int i; int slot; int ret; for(i = *level; i < BTRFS_MAX_LEVEL - 1 && path->nodes[i]; i++) { slot = path->slots[i]; if (slot < btrfs_header_nritems(path->nodes[i]) - 1) { struct extent_buffer *node; struct btrfs_disk_key disk_key; node = path->nodes[i]; path->slots[i]++; *level = i; WARN_ON(*level == 0); btrfs_node_key(node, &disk_key, path->slots[i]); memcpy(&root_item->drop_progress, &disk_key, sizeof(disk_key)); root_item->drop_level = i; return 0; } else { if (path->nodes[*level] == root->node) { root_owner = root->root_key.objectid; root_gen = btrfs_header_generation(path->nodes[*level]); } else { struct extent_buffer *node; node = path->nodes[*level + 1]; root_owner = btrfs_header_owner(node); root_gen = btrfs_header_generation(node); } ret = btrfs_free_extent(trans, root, path->nodes[*level]->start, path->nodes[*level]->len, root_owner, root_gen, 0, 0, 1); BUG_ON(ret); free_extent_buffer(path->nodes[*level]); path->nodes[*level] = NULL; *level = i + 1; } } return 1; } /* * drop the reference count on the tree rooted at 'snap'. This traverses * the tree freeing any blocks that have a ref count of zero after being * decremented. */ int btrfs_drop_snapshot(struct btrfs_trans_handle *trans, struct btrfs_root *root) { int ret = 0; int wret; int level; struct btrfs_path *path; int i; int orig_level; struct btrfs_root_item *root_item = &root->root_item; WARN_ON(!mutex_is_locked(&root->fs_info->drop_mutex)); path = btrfs_alloc_path(); BUG_ON(!path); level = btrfs_header_level(root->node); orig_level = level; if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { path->nodes[level] = root->node; extent_buffer_get(root->node); path->slots[level] = 0; } else { struct btrfs_key key; struct btrfs_disk_key found_key; struct extent_buffer *node; btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); level = root_item->drop_level; path->lowest_level = level; wret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (wret < 0) { ret = wret; goto out; } node = path->nodes[level]; btrfs_node_key(node, &found_key, path->slots[level]); WARN_ON(memcmp(&found_key, &root_item->drop_progress, sizeof(found_key))); /* * unlock our path, this is safe because only this * function is allowed to delete this snapshot */ for (i = 0; i < BTRFS_MAX_LEVEL; i++) { if (path->nodes[i] && path->locks[i]) { path->locks[i] = 0; btrfs_tree_unlock(path->nodes[i]); } } } while(1) { wret = walk_down_tree(trans, root, path, &level); if (wret > 0) break; if (wret < 0) ret = wret; wret = walk_up_tree(trans, root, path, &level); if (wret > 0) break; if (wret < 0) ret = wret; if (trans->transaction->in_commit) { ret = -EAGAIN; break; } } for (i = 0; i <= orig_level; i++) { if (path->nodes[i]) { free_extent_buffer(path->nodes[i]); path->nodes[i] = NULL; } } out: btrfs_free_path(path); return ret; } int btrfs_free_block_groups(struct btrfs_fs_info *info) { u64 start; u64 end; u64 ptr; int ret; mutex_lock(&info->alloc_mutex); while(1) { ret = find_first_extent_bit(&info->block_group_cache, 0, &start, &end, (unsigned int)-1); if (ret) break; ret = get_state_private(&info->block_group_cache, start, &ptr); if (!ret) kfree((void *)(unsigned long)ptr); clear_extent_bits(&info->block_group_cache, start, end, (unsigned int)-1, GFP_NOFS); } while(1) { ret = find_first_extent_bit(&info->free_space_cache, 0, &start, &end, EXTENT_DIRTY); if (ret) break; clear_extent_dirty(&info->free_space_cache, start, end, GFP_NOFS); } mutex_unlock(&info->alloc_mutex); return 0; } static unsigned long calc_ra(unsigned long start, unsigned long last, unsigned long nr) { return min(last, start + nr - 1); } static int noinline relocate_inode_pages(struct inode *inode, u64 start, u64 len) { u64 page_start; u64 page_end; unsigned long last_index; unsigned long i; struct page *page; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct file_ra_state *ra; unsigned long total_read = 0; unsigned long ra_pages; struct btrfs_ordered_extent *ordered; struct btrfs_trans_handle *trans; ra = kzalloc(sizeof(*ra), GFP_NOFS); mutex_lock(&inode->i_mutex); i = start >> PAGE_CACHE_SHIFT; last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; ra_pages = BTRFS_I(inode)->root->fs_info->bdi.ra_pages; file_ra_state_init(ra, inode->i_mapping); for (; i <= last_index; i++) { if (total_read % ra_pages == 0) { btrfs_force_ra(inode->i_mapping, ra, NULL, i, calc_ra(i, last_index, ra_pages)); } total_read++; again: if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) goto truncate_racing; page = grab_cache_page(inode->i_mapping, i); if (!page) { goto out_unlock; } if (!PageUptodate(page)) { btrfs_readpage(NULL, page); lock_page(page); if (!PageUptodate(page)) { unlock_page(page); page_cache_release(page); goto out_unlock; } } wait_on_page_writeback(page); page_start = (u64)page->index << PAGE_CACHE_SHIFT; page_end = page_start + PAGE_CACHE_SIZE - 1; lock_extent(io_tree, page_start, page_end, GFP_NOFS); ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } set_page_extent_mapped(page); set_extent_delalloc(io_tree, page_start, page_end, GFP_NOFS); set_page_dirty(page); unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); } out_unlock: /* we have to start the IO in order to get the ordered extents * instantiated. This allows the relocation to code to wait * for all the ordered extents to hit the disk. * * Otherwise, it would constantly loop over the same extents * because the old ones don't get deleted until the IO is * started */ btrfs_fdatawrite_range(inode->i_mapping, start, start + len - 1, WB_SYNC_NONE); kfree(ra); trans = btrfs_start_transaction(BTRFS_I(inode)->root, 1); if (trans) { btrfs_end_transaction(trans, BTRFS_I(inode)->root); mark_inode_dirty(inode); } mutex_unlock(&inode->i_mutex); return 0; truncate_racing: vmtruncate(inode, inode->i_size); balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_read); goto out_unlock; } /* * The back references tell us which tree holds a ref on a block, * but it is possible for the tree root field in the reference to * reflect the original root before a snapshot was made. In this * case we should search through all the children of a given root * to find potential holders of references on a block. * * Instead, we do something a little less fancy and just search * all the roots for a given key/block combination. */ static int find_root_for_ref(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key0, int level, int file_key, struct btrfs_root **found_root, u64 bytenr) { struct btrfs_key root_location; struct btrfs_root *cur_root = *found_root; struct btrfs_file_extent_item *file_extent; u64 root_search_start = BTRFS_FS_TREE_OBJECTID; u64 found_bytenr; int ret; root_location.offset = (u64)-1; root_location.type = BTRFS_ROOT_ITEM_KEY; path->lowest_level = level; path->reada = 0; while(1) { ret = btrfs_search_slot(NULL, cur_root, key0, path, 0, 0); found_bytenr = 0; if (ret == 0 && file_key) { struct extent_buffer *leaf = path->nodes[0]; file_extent = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, file_extent) == BTRFS_FILE_EXTENT_REG) { found_bytenr = btrfs_file_extent_disk_bytenr(leaf, file_extent); } } else if (!file_key) { if (path->nodes[level]) found_bytenr = path->nodes[level]->start; } btrfs_release_path(cur_root, path); if (found_bytenr == bytenr) { *found_root = cur_root; ret = 0; goto out; } ret = btrfs_search_root(root->fs_info->tree_root, root_search_start, &root_search_start); if (ret) break; root_location.objectid = root_search_start; cur_root = btrfs_read_fs_root_no_name(root->fs_info, &root_location); if (!cur_root) { ret = 1; break; } } out: path->lowest_level = 0; return ret; } /* * note, this releases the path */ static int noinline relocate_one_reference(struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key, u64 *last_file_objectid, u64 *last_file_offset, u64 *last_file_root, u64 last_extent) { struct inode *inode; struct btrfs_root *found_root; struct btrfs_key root_location; struct btrfs_key found_key; struct btrfs_extent_ref *ref; u64 ref_root; u64 ref_gen; u64 ref_objectid; u64 ref_offset; int ret; int level; WARN_ON(!mutex_is_locked(&extent_root->fs_info->alloc_mutex)); ref = btrfs_item_ptr(path->nodes[0], path->slots[0], struct btrfs_extent_ref); ref_root = btrfs_ref_root(path->nodes[0], ref); ref_gen = btrfs_ref_generation(path->nodes[0], ref); ref_objectid = btrfs_ref_objectid(path->nodes[0], ref); ref_offset = btrfs_ref_offset(path->nodes[0], ref); btrfs_release_path(extent_root, path); root_location.objectid = ref_root; if (ref_gen == 0) root_location.offset = 0; else root_location.offset = (u64)-1; root_location.type = BTRFS_ROOT_ITEM_KEY; found_root = btrfs_read_fs_root_no_name(extent_root->fs_info, &root_location); BUG_ON(!found_root); mutex_unlock(&extent_root->fs_info->alloc_mutex); if (ref_objectid >= BTRFS_FIRST_FREE_OBJECTID) { found_key.objectid = ref_objectid; found_key.type = BTRFS_EXTENT_DATA_KEY; found_key.offset = ref_offset; level = 0; if (last_extent == extent_key->objectid && *last_file_objectid == ref_objectid && *last_file_offset == ref_offset && *last_file_root == ref_root) goto out; ret = find_root_for_ref(extent_root, path, &found_key, level, 1, &found_root, extent_key->objectid); if (ret) goto out; if (last_extent == extent_key->objectid && *last_file_objectid == ref_objectid && *last_file_offset == ref_offset && *last_file_root == ref_root) goto out; inode = btrfs_iget_locked(extent_root->fs_info->sb, ref_objectid, found_root); if (inode->i_state & I_NEW) { /* the inode and parent dir are two different roots */ BTRFS_I(inode)->root = found_root; BTRFS_I(inode)->location.objectid = ref_objectid; BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; BTRFS_I(inode)->location.offset = 0; btrfs_read_locked_inode(inode); unlock_new_inode(inode); } /* this can happen if the reference is not against * the latest version of the tree root */ if (is_bad_inode(inode)) goto out; *last_file_objectid = inode->i_ino; *last_file_root = found_root->root_key.objectid; *last_file_offset = ref_offset; relocate_inode_pages(inode, ref_offset, extent_key->offset); iput(inode); } else { struct btrfs_trans_handle *trans; struct extent_buffer *eb; int needs_lock = 0; eb = read_tree_block(found_root, extent_key->objectid, extent_key->offset, 0); btrfs_tree_lock(eb); level = btrfs_header_level(eb); if (level == 0) btrfs_item_key_to_cpu(eb, &found_key, 0); else btrfs_node_key_to_cpu(eb, &found_key, 0); btrfs_tree_unlock(eb); free_extent_buffer(eb); ret = find_root_for_ref(extent_root, path, &found_key, level, 0, &found_root, extent_key->objectid); if (ret) goto out; /* * right here almost anything could happen to our key, * but that's ok. The cow below will either relocate it * or someone else will have relocated it. Either way, * it is in a different spot than it was before and * we're happy. */ trans = btrfs_start_transaction(found_root, 1); if (found_root == extent_root->fs_info->extent_root || found_root == extent_root->fs_info->chunk_root || found_root == extent_root->fs_info->dev_root) { needs_lock = 1; mutex_lock(&extent_root->fs_info->alloc_mutex); } path->lowest_level = level; path->reada = 2; ret = btrfs_search_slot(trans, found_root, &found_key, path, 0, 1); path->lowest_level = 0; btrfs_release_path(found_root, path); if (found_root == found_root->fs_info->extent_root) btrfs_extent_post_op(trans, found_root); if (needs_lock) mutex_unlock(&extent_root->fs_info->alloc_mutex); btrfs_end_transaction(trans, found_root); } out: mutex_lock(&extent_root->fs_info->alloc_mutex); return 0; } static int noinline del_extent_zero(struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key) { int ret; struct btrfs_trans_handle *trans; trans = btrfs_start_transaction(extent_root, 1); ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); if (ret > 0) { ret = -EIO; goto out; } if (ret < 0) goto out; ret = btrfs_del_item(trans, extent_root, path); out: btrfs_end_transaction(trans, extent_root); return ret; } static int noinline relocate_one_extent(struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key) { struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf; u64 last_file_objectid = 0; u64 last_file_root = 0; u64 last_file_offset = (u64)-1; u64 last_extent = 0; u32 nritems; u32 item_size; int ret = 0; if (extent_key->objectid == 0) { ret = del_extent_zero(extent_root, path, extent_key); goto out; } key.objectid = extent_key->objectid; key.type = BTRFS_EXTENT_REF_KEY; key.offset = 0; while(1) { ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; ret = 0; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); if (path->slots[0] == nritems) { ret = btrfs_next_leaf(extent_root, path); if (ret > 0) { ret = 0; goto out; } if (ret < 0) goto out; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != extent_key->objectid) { break; } if (found_key.type != BTRFS_EXTENT_REF_KEY) { break; } key.offset = found_key.offset + 1; item_size = btrfs_item_size_nr(leaf, path->slots[0]); ret = relocate_one_reference(extent_root, path, extent_key, &last_file_objectid, &last_file_offset, &last_file_root, last_extent); if (ret) goto out; last_extent = extent_key->objectid; } ret = 0; out: btrfs_release_path(extent_root, path); return ret; } static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) { u64 num_devices; u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; num_devices = root->fs_info->fs_devices->num_devices; if (num_devices == 1) { stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* turn raid0 into single device chunks */ if (flags & BTRFS_BLOCK_GROUP_RAID0) return stripped; /* turn mirroring into duplication */ if (flags & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) return stripped | BTRFS_BLOCK_GROUP_DUP; return flags; } else { /* they already had raid on here, just return */ if (flags & stripped) return flags; stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* switch duplicated blocks with raid1 */ if (flags & BTRFS_BLOCK_GROUP_DUP) return stripped | BTRFS_BLOCK_GROUP_RAID1; /* turn single device chunks into raid0 */ return stripped | BTRFS_BLOCK_GROUP_RAID0; } return flags; } int __alloc_chunk_for_shrink(struct btrfs_root *root, struct btrfs_block_group_cache *shrink_block_group, int force) { struct btrfs_trans_handle *trans; u64 new_alloc_flags; u64 calc; spin_lock(&shrink_block_group->lock); if (btrfs_block_group_used(&shrink_block_group->item) > 0) { spin_unlock(&shrink_block_group->lock); mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(root, 1); mutex_lock(&root->fs_info->alloc_mutex); spin_lock(&shrink_block_group->lock); new_alloc_flags = update_block_group_flags(root, shrink_block_group->flags); if (new_alloc_flags != shrink_block_group->flags) { calc = btrfs_block_group_used(&shrink_block_group->item); } else { calc = shrink_block_group->key.offset; } spin_unlock(&shrink_block_group->lock); do_chunk_alloc(trans, root->fs_info->extent_root, calc + 2 * 1024 * 1024, new_alloc_flags, force); mutex_unlock(&root->fs_info->alloc_mutex); btrfs_end_transaction(trans, root); mutex_lock(&root->fs_info->alloc_mutex); } else spin_unlock(&shrink_block_group->lock); return 0; } int btrfs_shrink_extent_tree(struct btrfs_root *root, u64 shrink_start) { struct btrfs_trans_handle *trans; struct btrfs_root *tree_root = root->fs_info->tree_root; struct btrfs_path *path; u64 cur_byte; u64 total_found; u64 shrink_last_byte; struct btrfs_block_group_cache *shrink_block_group; struct btrfs_fs_info *info = root->fs_info; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf; u32 nritems; int ret; int progress; mutex_lock(&root->fs_info->alloc_mutex); shrink_block_group = btrfs_lookup_block_group(root->fs_info, shrink_start); BUG_ON(!shrink_block_group); shrink_last_byte = shrink_block_group->key.objectid + shrink_block_group->key.offset; shrink_block_group->space_info->total_bytes -= shrink_block_group->key.offset; path = btrfs_alloc_path(); root = root->fs_info->extent_root; path->reada = 2; printk("btrfs relocating block group %llu flags %llu\n", (unsigned long long)shrink_start, (unsigned long long)shrink_block_group->flags); __alloc_chunk_for_shrink(root, shrink_block_group, 1); again: shrink_block_group->ro = 1; total_found = 0; progress = 0; key.objectid = shrink_start; key.offset = 0; key.type = 0; cur_byte = key.objectid; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; ret = btrfs_previous_item(root, path, 0, BTRFS_EXTENT_ITEM_KEY); if (ret < 0) goto out; if (ret == 0) { leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid + found_key.offset > shrink_start && found_key.objectid < shrink_last_byte) { cur_byte = found_key.objectid; key.objectid = cur_byte; } } btrfs_release_path(root, path); while(1) { ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); if (ret < 0) goto out; next: leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; if (ret == 1) { ret = 0; break; } leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid >= shrink_last_byte) break; if (progress && need_resched()) { memcpy(&key, &found_key, sizeof(key)); cond_resched(); btrfs_release_path(root, path); btrfs_search_slot(NULL, root, &key, path, 0, 0); progress = 0; goto next; } progress = 1; if (btrfs_key_type(&found_key) != BTRFS_EXTENT_ITEM_KEY || found_key.objectid + found_key.offset <= cur_byte) { memcpy(&key, &found_key, sizeof(key)); key.offset++; path->slots[0]++; goto next; } total_found++; cur_byte = found_key.objectid + found_key.offset; key.objectid = cur_byte; btrfs_release_path(root, path); ret = relocate_one_extent(root, path, &found_key); __alloc_chunk_for_shrink(root, shrink_block_group, 0); } btrfs_release_path(root, path); if (total_found > 0) { printk("btrfs relocate found %llu last extent was %llu\n", (unsigned long long)total_found, (unsigned long long)found_key.objectid); mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(tree_root, 1); btrfs_commit_transaction(trans, tree_root); btrfs_clean_old_snapshots(tree_root); btrfs_wait_ordered_extents(tree_root); trans = btrfs_start_transaction(tree_root, 1); btrfs_commit_transaction(trans, tree_root); mutex_lock(&root->fs_info->alloc_mutex); goto again; } /* * we've freed all the extents, now remove the block * group item from the tree */ mutex_unlock(&root->fs_info->alloc_mutex); trans = btrfs_start_transaction(root, 1); mutex_lock(&root->fs_info->alloc_mutex); memcpy(&key, &shrink_block_group->key, sizeof(key)); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -EIO; if (ret < 0) { btrfs_end_transaction(trans, root); goto out; } clear_extent_bits(&info->block_group_cache, key.objectid, key.objectid + key.offset - 1, (unsigned int)-1, GFP_NOFS); clear_extent_bits(&info->free_space_cache, key.objectid, key.objectid + key.offset - 1, (unsigned int)-1, GFP_NOFS); memset(shrink_block_group, 0, sizeof(*shrink_block_group)); kfree(shrink_block_group); btrfs_del_item(trans, root, path); btrfs_release_path(root, path); mutex_unlock(&root->fs_info->alloc_mutex); btrfs_commit_transaction(trans, root); mutex_lock(&root->fs_info->alloc_mutex); /* the code to unpin extents might set a few bits in the free * space cache for this range again */ clear_extent_bits(&info->free_space_cache, key.objectid, key.objectid + key.offset - 1, (unsigned int)-1, GFP_NOFS); out: btrfs_free_path(path); mutex_unlock(&root->fs_info->alloc_mutex); return ret; } int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key) { int ret = 0; struct btrfs_key found_key; struct extent_buffer *leaf; int slot; ret = btrfs_search_slot(NULL, root, key, path, 0, 0); if (ret < 0) goto out; while(1) { slot = path->slots[0]; leaf = path->nodes[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto out; break; } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid >= key->objectid && found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { ret = 0; goto out; } path->slots[0]++; } ret = -ENOENT; out: return ret; } int btrfs_read_block_groups(struct btrfs_root *root) { struct btrfs_path *path; int ret; int bit; struct btrfs_block_group_cache *cache; struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *space_info; struct extent_io_tree *block_group_cache; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf; block_group_cache = &info->block_group_cache; root = info->extent_root; key.objectid = 0; key.offset = 0; btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); path = btrfs_alloc_path(); if (!path) return -ENOMEM; mutex_lock(&root->fs_info->alloc_mutex); while(1) { ret = find_first_block_group(root, path, &key); if (ret > 0) { ret = 0; goto error; } if (ret != 0) goto error; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); cache = kzalloc(sizeof(*cache), GFP_NOFS); if (!cache) { ret = -ENOMEM; break; } spin_lock_init(&cache->lock); read_extent_buffer(leaf, &cache->item, btrfs_item_ptr_offset(leaf, path->slots[0]), sizeof(cache->item)); memcpy(&cache->key, &found_key, sizeof(found_key)); key.objectid = found_key.objectid + found_key.offset; btrfs_release_path(root, path); cache->flags = btrfs_block_group_flags(&cache->item); bit = 0; if (cache->flags & BTRFS_BLOCK_GROUP_DATA) { bit = BLOCK_GROUP_DATA; } else if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { bit = BLOCK_GROUP_SYSTEM; } else if (cache->flags & BTRFS_BLOCK_GROUP_METADATA) { bit = BLOCK_GROUP_METADATA; } set_avail_alloc_bits(info, cache->flags); ret = update_space_info(info, cache->flags, found_key.offset, btrfs_block_group_used(&cache->item), &space_info); BUG_ON(ret); cache->space_info = space_info; /* use EXTENT_LOCKED to prevent merging */ set_extent_bits(block_group_cache, found_key.objectid, found_key.objectid + found_key.offset - 1, EXTENT_LOCKED, GFP_NOFS); set_state_private(block_group_cache, found_key.objectid, (unsigned long)cache); set_extent_bits(block_group_cache, found_key.objectid, found_key.objectid + found_key.offset - 1, bit | EXTENT_LOCKED, GFP_NOFS); if (key.objectid >= btrfs_super_total_bytes(&info->super_copy)) break; } ret = 0; error: btrfs_free_path(path); mutex_unlock(&root->fs_info->alloc_mutex); return ret; } int btrfs_make_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytes_used, u64 type, u64 chunk_objectid, u64 chunk_offset, u64 size) { int ret; int bit = 0; struct btrfs_root *extent_root; struct btrfs_block_group_cache *cache; struct extent_io_tree *block_group_cache; WARN_ON(!mutex_is_locked(&root->fs_info->alloc_mutex)); extent_root = root->fs_info->extent_root; block_group_cache = &root->fs_info->block_group_cache; cache = kzalloc(sizeof(*cache), GFP_NOFS); BUG_ON(!cache); cache->key.objectid = chunk_offset; cache->key.offset = size; spin_lock_init(&cache->lock); btrfs_set_key_type(&cache->key, BTRFS_BLOCK_GROUP_ITEM_KEY); btrfs_set_block_group_used(&cache->item, bytes_used); btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); cache->flags = type; btrfs_set_block_group_flags(&cache->item, type); ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, &cache->space_info); BUG_ON(ret); bit = block_group_state_bits(type); set_extent_bits(block_group_cache, chunk_offset, chunk_offset + size - 1, EXTENT_LOCKED, GFP_NOFS); set_state_private(block_group_cache, chunk_offset, (unsigned long)cache); set_extent_bits(block_group_cache, chunk_offset, chunk_offset + size - 1, bit | EXTENT_LOCKED, GFP_NOFS); ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, sizeof(cache->item)); BUG_ON(ret); finish_current_insert(trans, extent_root); ret = del_pending_extents(trans, extent_root); BUG_ON(ret); set_avail_alloc_bits(extent_root->fs_info, type); return 0; }