// SPDX-License-Identifier: GPL-2.0 /* * Copyright (C) 2007 Oracle. All rights reserved. */ #include #include #include #include #include #include #include #include #include #include #include #include #include #include "tree-log.h" #include "disk-io.h" #include "print-tree.h" #include "volumes.h" #include "raid56.h" #include "locking.h" #include "free-space-cache.h" #include "free-space-tree.h" #include "math.h" #include "sysfs.h" #include "qgroup.h" #include "ref-verify.h" #include "space-info.h" #include "block-rsv.h" #include "delalloc-space.h" #include "block-group.h" #undef SCRAMBLE_DELAYED_REFS static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, u64 parent, u64 root_objectid, u64 owner_objectid, u64 owner_offset, int refs_to_drop, struct btrfs_delayed_extent_op *extra_op); static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, struct extent_buffer *leaf, struct btrfs_extent_item *ei); static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, u64 parent, u64 root_objectid, u64 flags, u64 owner, u64 offset, struct btrfs_key *ins, int ref_mod); static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op); static int find_next_key(struct btrfs_path *path, int level, struct btrfs_key *key); static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) { return (cache->flags & bits) == bits; } /* * this adds the block group to the fs_info rb tree for the block group * cache */ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, struct btrfs_block_group_cache *block_group) { struct rb_node **p; struct rb_node *parent = NULL; struct btrfs_block_group_cache *cache; spin_lock(&info->block_group_cache_lock); p = &info->block_group_cache_tree.rb_node; while (*p) { parent = *p; cache = rb_entry(parent, struct btrfs_block_group_cache, cache_node); if (block_group->key.objectid < cache->key.objectid) { p = &(*p)->rb_left; } else if (block_group->key.objectid > cache->key.objectid) { p = &(*p)->rb_right; } else { spin_unlock(&info->block_group_cache_lock); return -EEXIST; } } rb_link_node(&block_group->cache_node, parent, p); rb_insert_color(&block_group->cache_node, &info->block_group_cache_tree); if (info->first_logical_byte > block_group->key.objectid) info->first_logical_byte = block_group->key.objectid; spin_unlock(&info->block_group_cache_lock); return 0; } int btrfs_add_excluded_extent(struct btrfs_fs_info *fs_info, u64 start, u64 num_bytes) { u64 end = start + num_bytes - 1; set_extent_bits(&fs_info->freed_extents[0], start, end, EXTENT_UPTODATE); set_extent_bits(&fs_info->freed_extents[1], start, end, EXTENT_UPTODATE); return 0; } void btrfs_free_excluded_extents(struct btrfs_block_group_cache *cache) { struct btrfs_fs_info *fs_info = cache->fs_info; u64 start, end; start = cache->key.objectid; end = start + cache->key.offset - 1; clear_extent_bits(&fs_info->freed_extents[0], start, end, EXTENT_UPTODATE); clear_extent_bits(&fs_info->freed_extents[1], start, end, EXTENT_UPTODATE); } static int exclude_super_stripes(struct btrfs_block_group_cache *cache) { struct btrfs_fs_info *fs_info = cache->fs_info; u64 bytenr; u64 *logical; int stripe_len; int i, nr, ret; if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) { stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid; cache->bytes_super += stripe_len; ret = btrfs_add_excluded_extent(fs_info, cache->key.objectid, stripe_len); if (ret) return ret; } for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); ret = btrfs_rmap_block(fs_info, cache->key.objectid, bytenr, &logical, &nr, &stripe_len); if (ret) return ret; while (nr--) { u64 start, len; if (logical[nr] > cache->key.objectid + cache->key.offset) continue; if (logical[nr] + stripe_len <= cache->key.objectid) continue; start = logical[nr]; if (start < cache->key.objectid) { start = cache->key.objectid; len = (logical[nr] + stripe_len) - start; } else { len = min_t(u64, stripe_len, cache->key.objectid + cache->key.offset - start); } cache->bytes_super += len; ret = btrfs_add_excluded_extent(fs_info, start, len); if (ret) { kfree(logical); return ret; } } kfree(logical); } return 0; } struct btrfs_caching_control *btrfs_get_caching_control( struct btrfs_block_group_cache *cache) { struct btrfs_caching_control *ctl; spin_lock(&cache->lock); if (!cache->caching_ctl) { spin_unlock(&cache->lock); return NULL; } ctl = cache->caching_ctl; refcount_inc(&ctl->count); spin_unlock(&cache->lock); return ctl; } void btrfs_put_caching_control(struct btrfs_caching_control *ctl) { if (refcount_dec_and_test(&ctl->count)) kfree(ctl); } #ifdef CONFIG_BTRFS_DEBUG void btrfs_fragment_free_space(struct btrfs_block_group_cache *block_group) { struct btrfs_fs_info *fs_info = block_group->fs_info; u64 start = block_group->key.objectid; u64 len = block_group->key.offset; u64 chunk = block_group->flags & BTRFS_BLOCK_GROUP_METADATA ? fs_info->nodesize : fs_info->sectorsize; u64 step = chunk << 1; while (len > chunk) { btrfs_remove_free_space(block_group, start, chunk); start += step; if (len < step) len = 0; else len -= step; } } #endif /* * This is only called by btrfs_cache_block_group, since we could have freed * extents we need to check the pinned_extents for any extents that can't be * used yet since their free space will be released as soon as the transaction * commits. */ u64 add_new_free_space(struct btrfs_block_group_cache *block_group, u64 start, u64 end) { struct btrfs_fs_info *info = block_group->fs_info; u64 extent_start, extent_end, size, total_added = 0; int ret; while (start < end) { ret = find_first_extent_bit(info->pinned_extents, start, &extent_start, &extent_end, EXTENT_DIRTY | EXTENT_UPTODATE, NULL); if (ret) break; if (extent_start <= start) { start = extent_end + 1; } else if (extent_start > start && extent_start < end) { size = extent_start - start; total_added += size; ret = btrfs_add_free_space(block_group, start, size); BUG_ON(ret); /* -ENOMEM or logic error */ start = extent_end + 1; } else { break; } } if (start < end) { size = end - start; total_added += size; ret = btrfs_add_free_space(block_group, start, size); BUG_ON(ret); /* -ENOMEM or logic error */ } return total_added; } static int load_extent_tree_free(struct btrfs_caching_control *caching_ctl) { struct btrfs_block_group_cache *block_group = caching_ctl->block_group; struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_root *extent_root = fs_info->extent_root; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_key key; u64 total_found = 0; u64 last = 0; u32 nritems; int ret; bool wakeup = true; path = btrfs_alloc_path(); if (!path) return -ENOMEM; last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); #ifdef CONFIG_BTRFS_DEBUG /* * If we're fragmenting we don't want to make anybody think we can * allocate from this block group until we've had a chance to fragment * the free space. */ if (btrfs_should_fragment_free_space(block_group)) wakeup = false; #endif /* * We don't want to deadlock with somebody trying to allocate a new * extent for the extent root while also trying to search the extent * root to add free space. So we skip locking and search the commit * root, since its read-only */ path->skip_locking = 1; path->search_commit_root = 1; path->reada = READA_FORWARD; key.objectid = last; key.offset = 0; key.type = BTRFS_EXTENT_ITEM_KEY; next: ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); while (1) { if (btrfs_fs_closing(fs_info) > 1) { last = (u64)-1; break; } if (path->slots[0] < nritems) { btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); } else { ret = btrfs_find_next_key(extent_root, path, &key, 0, 0); if (ret) break; if (need_resched() || rwsem_is_contended(&fs_info->commit_root_sem)) { if (wakeup) caching_ctl->progress = last; btrfs_release_path(path); up_read(&fs_info->commit_root_sem); mutex_unlock(&caching_ctl->mutex); cond_resched(); mutex_lock(&caching_ctl->mutex); down_read(&fs_info->commit_root_sem); goto next; } ret = btrfs_next_leaf(extent_root, path); if (ret < 0) goto out; if (ret) break; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); continue; } if (key.objectid < last) { key.objectid = last; key.offset = 0; key.type = BTRFS_EXTENT_ITEM_KEY; if (wakeup) caching_ctl->progress = last; btrfs_release_path(path); goto next; } if (key.objectid < block_group->key.objectid) { path->slots[0]++; continue; } if (key.objectid >= block_group->key.objectid + block_group->key.offset) break; if (key.type == BTRFS_EXTENT_ITEM_KEY || key.type == BTRFS_METADATA_ITEM_KEY) { total_found += add_new_free_space(block_group, last, key.objectid); if (key.type == BTRFS_METADATA_ITEM_KEY) last = key.objectid + fs_info->nodesize; else last = key.objectid + key.offset; if (total_found > CACHING_CTL_WAKE_UP) { total_found = 0; if (wakeup) wake_up(&caching_ctl->wait); } } path->slots[0]++; } ret = 0; total_found += add_new_free_space(block_group, last, block_group->key.objectid + block_group->key.offset); caching_ctl->progress = (u64)-1; out: btrfs_free_path(path); return ret; } static noinline void caching_thread(struct btrfs_work *work) { struct btrfs_block_group_cache *block_group; struct btrfs_fs_info *fs_info; struct btrfs_caching_control *caching_ctl; int ret; caching_ctl = container_of(work, struct btrfs_caching_control, work); block_group = caching_ctl->block_group; fs_info = block_group->fs_info; mutex_lock(&caching_ctl->mutex); down_read(&fs_info->commit_root_sem); if (btrfs_fs_compat_ro(fs_info, FREE_SPACE_TREE)) ret = load_free_space_tree(caching_ctl); else ret = load_extent_tree_free(caching_ctl); spin_lock(&block_group->lock); block_group->caching_ctl = NULL; block_group->cached = ret ? BTRFS_CACHE_ERROR : BTRFS_CACHE_FINISHED; spin_unlock(&block_group->lock); #ifdef CONFIG_BTRFS_DEBUG if (btrfs_should_fragment_free_space(block_group)) { u64 bytes_used; spin_lock(&block_group->space_info->lock); spin_lock(&block_group->lock); bytes_used = block_group->key.offset - btrfs_block_group_used(&block_group->item); block_group->space_info->bytes_used += bytes_used >> 1; spin_unlock(&block_group->lock); spin_unlock(&block_group->space_info->lock); btrfs_fragment_free_space(block_group); } #endif caching_ctl->progress = (u64)-1; up_read(&fs_info->commit_root_sem); btrfs_free_excluded_extents(block_group); mutex_unlock(&caching_ctl->mutex); wake_up(&caching_ctl->wait); btrfs_put_caching_control(caching_ctl); btrfs_put_block_group(block_group); } int btrfs_cache_block_group(struct btrfs_block_group_cache *cache, int load_cache_only) { DEFINE_WAIT(wait); struct btrfs_fs_info *fs_info = cache->fs_info; struct btrfs_caching_control *caching_ctl; int ret = 0; caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS); if (!caching_ctl) return -ENOMEM; INIT_LIST_HEAD(&caching_ctl->list); mutex_init(&caching_ctl->mutex); init_waitqueue_head(&caching_ctl->wait); caching_ctl->block_group = cache; caching_ctl->progress = cache->key.objectid; refcount_set(&caching_ctl->count, 1); btrfs_init_work(&caching_ctl->work, btrfs_cache_helper, caching_thread, NULL, NULL); spin_lock(&cache->lock); /* * This should be a rare occasion, but this could happen I think in the * case where one thread starts to load the space cache info, and then * some other thread starts a transaction commit which tries to do an * allocation while the other thread is still loading the space cache * info. The previous loop should have kept us from choosing this block * group, but if we've moved to the state where we will wait on caching * block groups we need to first check if we're doing a fast load here, * so we can wait for it to finish, otherwise we could end up allocating * from a block group who's cache gets evicted for one reason or * another. */ while (cache->cached == BTRFS_CACHE_FAST) { struct btrfs_caching_control *ctl; ctl = cache->caching_ctl; refcount_inc(&ctl->count); prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE); spin_unlock(&cache->lock); schedule(); finish_wait(&ctl->wait, &wait); btrfs_put_caching_control(ctl); spin_lock(&cache->lock); } if (cache->cached != BTRFS_CACHE_NO) { spin_unlock(&cache->lock); kfree(caching_ctl); return 0; } WARN_ON(cache->caching_ctl); cache->caching_ctl = caching_ctl; cache->cached = BTRFS_CACHE_FAST; spin_unlock(&cache->lock); if (btrfs_test_opt(fs_info, SPACE_CACHE)) { mutex_lock(&caching_ctl->mutex); ret = load_free_space_cache(cache); spin_lock(&cache->lock); if (ret == 1) { cache->caching_ctl = NULL; cache->cached = BTRFS_CACHE_FINISHED; cache->last_byte_to_unpin = (u64)-1; caching_ctl->progress = (u64)-1; } else { if (load_cache_only) { cache->caching_ctl = NULL; cache->cached = BTRFS_CACHE_NO; } else { cache->cached = BTRFS_CACHE_STARTED; cache->has_caching_ctl = 1; } } spin_unlock(&cache->lock); #ifdef CONFIG_BTRFS_DEBUG if (ret == 1 && btrfs_should_fragment_free_space(cache)) { u64 bytes_used; spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); bytes_used = cache->key.offset - btrfs_block_group_used(&cache->item); cache->space_info->bytes_used += bytes_used >> 1; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); btrfs_fragment_free_space(cache); } #endif mutex_unlock(&caching_ctl->mutex); wake_up(&caching_ctl->wait); if (ret == 1) { btrfs_put_caching_control(caching_ctl); btrfs_free_excluded_extents(cache); return 0; } } else { /* * We're either using the free space tree or no caching at all. * Set cached to the appropriate value and wakeup any waiters. */ spin_lock(&cache->lock); if (load_cache_only) { cache->caching_ctl = NULL; cache->cached = BTRFS_CACHE_NO; } else { cache->cached = BTRFS_CACHE_STARTED; cache->has_caching_ctl = 1; } spin_unlock(&cache->lock); wake_up(&caching_ctl->wait); } if (load_cache_only) { btrfs_put_caching_control(caching_ctl); return 0; } down_write(&fs_info->commit_root_sem); refcount_inc(&caching_ctl->count); list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); up_write(&fs_info->commit_root_sem); btrfs_get_block_group(cache); btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work); return ret; } static u64 generic_ref_to_space_flags(struct btrfs_ref *ref) { if (ref->type == BTRFS_REF_METADATA) { if (ref->tree_ref.root == BTRFS_CHUNK_TREE_OBJECTID) return BTRFS_BLOCK_GROUP_SYSTEM; else return BTRFS_BLOCK_GROUP_METADATA; } return BTRFS_BLOCK_GROUP_DATA; } static void add_pinned_bytes(struct btrfs_fs_info *fs_info, struct btrfs_ref *ref) { struct btrfs_space_info *space_info; u64 flags = generic_ref_to_space_flags(ref); space_info = btrfs_find_space_info(fs_info, flags); ASSERT(space_info); percpu_counter_add_batch(&space_info->total_bytes_pinned, ref->len, BTRFS_TOTAL_BYTES_PINNED_BATCH); } static void sub_pinned_bytes(struct btrfs_fs_info *fs_info, struct btrfs_ref *ref) { struct btrfs_space_info *space_info; u64 flags = generic_ref_to_space_flags(ref); space_info = btrfs_find_space_info(fs_info, flags); ASSERT(space_info); percpu_counter_add_batch(&space_info->total_bytes_pinned, -ref->len, BTRFS_TOTAL_BYTES_PINNED_BATCH); } /* simple helper to search for an existing data extent at a given offset */ int btrfs_lookup_data_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len) { int ret; struct btrfs_key key; struct btrfs_path *path; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = start; key.offset = len; key.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_search_slot(NULL, fs_info->extent_root, &key, path, 0, 0); btrfs_free_path(path); return ret; } /* * helper function to lookup reference count and flags of a tree block. * * the head node for delayed ref is used to store the sum of all the * reference count modifications queued up in the rbtree. the head * node may also store the extent flags to set. This way you can check * to see what the reference count and extent flags would be if all of * the delayed refs are not processed. */ int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans, struct btrfs_fs_info *fs_info, u64 bytenr, u64 offset, int metadata, u64 *refs, u64 *flags) { struct btrfs_delayed_ref_head *head; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_path *path; struct btrfs_extent_item *ei; struct extent_buffer *leaf; struct btrfs_key key; u32 item_size; u64 num_refs; u64 extent_flags; int ret; /* * If we don't have skinny metadata, don't bother doing anything * different */ if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) { offset = fs_info->nodesize; metadata = 0; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (!trans) { path->skip_locking = 1; path->search_commit_root = 1; } search_again: key.objectid = bytenr; key.offset = offset; if (metadata) key.type = BTRFS_METADATA_ITEM_KEY; else key.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 0); if (ret < 0) goto out_free; if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) { if (path->slots[0]) { path->slots[0]--; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid == bytenr && key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == fs_info->nodesize) ret = 0; } } if (ret == 0) { leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); if (item_size >= sizeof(*ei)) { ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); num_refs = btrfs_extent_refs(leaf, ei); extent_flags = btrfs_extent_flags(leaf, ei); } else { ret = -EINVAL; btrfs_print_v0_err(fs_info); if (trans) btrfs_abort_transaction(trans, ret); else btrfs_handle_fs_error(fs_info, ret, NULL); goto out_free; } BUG_ON(num_refs == 0); } else { num_refs = 0; extent_flags = 0; ret = 0; } if (!trans) goto out; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); if (head) { if (!mutex_trylock(&head->mutex)) { refcount_inc(&head->refs); spin_unlock(&delayed_refs->lock); btrfs_release_path(path); /* * Mutex was contended, block until it's released and try * again */ mutex_lock(&head->mutex); mutex_unlock(&head->mutex); btrfs_put_delayed_ref_head(head); goto search_again; } spin_lock(&head->lock); if (head->extent_op && head->extent_op->update_flags) extent_flags |= head->extent_op->flags_to_set; else BUG_ON(num_refs == 0); num_refs += head->ref_mod; spin_unlock(&head->lock); mutex_unlock(&head->mutex); } spin_unlock(&delayed_refs->lock); out: WARN_ON(num_refs == 0); if (refs) *refs = num_refs; if (flags) *flags = extent_flags; out_free: btrfs_free_path(path); return ret; } /* * Back reference rules. Back refs have three main goals: * * 1) differentiate between all holders of references to an extent so that * when a reference is dropped we can make sure it was a valid reference * before freeing the extent. * * 2) Provide enough information to quickly find the holders of an extent * if we notice a given block is corrupted or bad. * * 3) Make it easy to migrate blocks for FS shrinking or storage pool * maintenance. This is actually the same as #2, but with a slightly * different use case. * * There are two kinds of back refs. The implicit back refs is optimized * for pointers in non-shared tree blocks. For a given pointer in a block, * back refs of this kind provide information about the block's owner tree * and the pointer's key. These information allow us to find the block by * b-tree searching. The full back refs is for pointers in tree blocks not * referenced by their owner trees. The location of tree block is recorded * in the back refs. Actually the full back refs is generic, and can be * used in all cases the implicit back refs is used. The major shortcoming * of the full back refs is its overhead. Every time a tree block gets * COWed, we have to update back refs entry for all pointers in it. * * For a newly allocated tree block, we use implicit back refs for * pointers in it. This means most tree related operations only involve * implicit back refs. For a tree block created in old transaction, the * only way to drop a reference to it is COW it. So we can detect the * event that tree block loses its owner tree's reference and do the * back refs conversion. * * When a tree block is COWed through a tree, there are four cases: * * The reference count of the block is one and the tree is the block's * owner tree. Nothing to do in this case. * * The reference count of the block is one and the tree is not the * block's owner tree. In this case, full back refs is used for pointers * in the block. Remove these full back refs, add implicit back refs for * every pointers in the new block. * * The reference count of the block is greater than one and the tree is * the block's owner tree. In this case, implicit back refs is used for * pointers in the block. Add full back refs for every pointers in the * block, increase lower level extents' reference counts. The original * implicit back refs are entailed to the new block. * * The reference count of the block is greater than one and the tree is * not the block's owner tree. Add implicit back refs for every pointer in * the new block, increase lower level extents' reference count. * * Back Reference Key composing: * * The key objectid corresponds to the first byte in the extent, * The key type is used to differentiate between types of back refs. * There are different meanings of the key offset for different types * of back refs. * * File extents can be referenced by: * * - multiple snapshots, subvolumes, or different generations in one subvol * - different files inside a single subvolume * - different offsets inside a file (bookend extents in file.c) * * The extent ref structure for the implicit back refs has fields for: * * - Objectid of the subvolume root * - objectid of the file holding the reference * - original offset in the file * - how many bookend extents * * The key offset for the implicit back refs is hash of the first * three fields. * * The extent ref structure for the full back refs has field for: * * - number of pointers in the tree leaf * * The key offset for the implicit back refs is the first byte of * the tree leaf * * When a file extent is allocated, The implicit back refs is used. * the fields are filled in: * * (root_key.objectid, inode objectid, offset in file, 1) * * When a file extent is removed file truncation, we find the * corresponding implicit back refs and check the following fields: * * (btrfs_header_owner(leaf), inode objectid, offset in file) * * Btree extents can be referenced by: * * - Different subvolumes * * Both the implicit back refs and the full back refs for tree blocks * only consist of key. The key offset for the implicit back refs is * objectid of block's owner tree. The key offset for the full back refs * is the first byte of parent block. * * When implicit back refs is used, information about the lowest key and * level of the tree block are required. These information are stored in * tree block info structure. */ /* * is_data == BTRFS_REF_TYPE_BLOCK, tree block type is required, * is_data == BTRFS_REF_TYPE_DATA, data type is requiried, * is_data == BTRFS_REF_TYPE_ANY, either type is OK. */ int btrfs_get_extent_inline_ref_type(const struct extent_buffer *eb, struct btrfs_extent_inline_ref *iref, enum btrfs_inline_ref_type is_data) { int type = btrfs_extent_inline_ref_type(eb, iref); u64 offset = btrfs_extent_inline_ref_offset(eb, iref); if (type == BTRFS_TREE_BLOCK_REF_KEY || type == BTRFS_SHARED_BLOCK_REF_KEY || type == BTRFS_SHARED_DATA_REF_KEY || type == BTRFS_EXTENT_DATA_REF_KEY) { if (is_data == BTRFS_REF_TYPE_BLOCK) { if (type == BTRFS_TREE_BLOCK_REF_KEY) return type; if (type == BTRFS_SHARED_BLOCK_REF_KEY) { ASSERT(eb->fs_info); /* * Every shared one has parent tree * block, which must be aligned to * nodesize. */ if (offset && IS_ALIGNED(offset, eb->fs_info->nodesize)) return type; } } else if (is_data == BTRFS_REF_TYPE_DATA) { if (type == BTRFS_EXTENT_DATA_REF_KEY) return type; if (type == BTRFS_SHARED_DATA_REF_KEY) { ASSERT(eb->fs_info); /* * Every shared one has parent tree * block, which must be aligned to * nodesize. */ if (offset && IS_ALIGNED(offset, eb->fs_info->nodesize)) return type; } } else { ASSERT(is_data == BTRFS_REF_TYPE_ANY); return type; } } btrfs_print_leaf((struct extent_buffer *)eb); btrfs_err(eb->fs_info, "eb %llu invalid extent inline ref type %d", eb->start, type); WARN_ON(1); return BTRFS_REF_TYPE_INVALID; } static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset) { u32 high_crc = ~(u32)0; u32 low_crc = ~(u32)0; __le64 lenum; lenum = cpu_to_le64(root_objectid); high_crc = btrfs_crc32c(high_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(owner); low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(offset); low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); return ((u64)high_crc << 31) ^ (u64)low_crc; } static u64 hash_extent_data_ref_item(struct extent_buffer *leaf, struct btrfs_extent_data_ref *ref) { return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref), btrfs_extent_data_ref_objectid(leaf, ref), btrfs_extent_data_ref_offset(leaf, ref)); } static int match_extent_data_ref(struct extent_buffer *leaf, struct btrfs_extent_data_ref *ref, u64 root_objectid, u64 owner, u64 offset) { if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid || btrfs_extent_data_ref_objectid(leaf, ref) != owner || btrfs_extent_data_ref_offset(leaf, ref) != offset) return 0; return 1; } static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset) { struct btrfs_root *root = trans->fs_info->extent_root; struct btrfs_key key; struct btrfs_extent_data_ref *ref; struct extent_buffer *leaf; u32 nritems; int ret; int recow; int err = -ENOENT; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_DATA_REF_KEY; key.offset = parent; } else { key.type = BTRFS_EXTENT_DATA_REF_KEY; key.offset = hash_extent_data_ref(root_objectid, owner, offset); } again: recow = 0; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) { err = ret; goto fail; } if (parent) { if (!ret) return 0; goto fail; } leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); while (1) { if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) err = ret; if (ret) goto fail; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); recow = 1; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != bytenr || key.type != BTRFS_EXTENT_DATA_REF_KEY) goto fail; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); if (match_extent_data_ref(leaf, ref, root_objectid, owner, offset)) { if (recow) { btrfs_release_path(path); goto again; } err = 0; break; } path->slots[0]++; } fail: return err; } static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add) { struct btrfs_root *root = trans->fs_info->extent_root; struct btrfs_key key; struct extent_buffer *leaf; u32 size; u32 num_refs; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_DATA_REF_KEY; key.offset = parent; size = sizeof(struct btrfs_shared_data_ref); } else { key.type = BTRFS_EXTENT_DATA_REF_KEY; key.offset = hash_extent_data_ref(root_objectid, owner, offset); size = sizeof(struct btrfs_extent_data_ref); } ret = btrfs_insert_empty_item(trans, root, path, &key, size); if (ret && ret != -EEXIST) goto fail; leaf = path->nodes[0]; if (parent) { struct btrfs_shared_data_ref *ref; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); if (ret == 0) { btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add); } else { num_refs = btrfs_shared_data_ref_count(leaf, ref); num_refs += refs_to_add; btrfs_set_shared_data_ref_count(leaf, ref, num_refs); } } else { struct btrfs_extent_data_ref *ref; while (ret == -EEXIST) { ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); if (match_extent_data_ref(leaf, ref, root_objectid, owner, offset)) break; btrfs_release_path(path); key.offset++; ret = btrfs_insert_empty_item(trans, root, path, &key, size); if (ret && ret != -EEXIST) goto fail; leaf = path->nodes[0]; } ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); if (ret == 0) { btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); btrfs_set_extent_data_ref_objectid(leaf, ref, owner); btrfs_set_extent_data_ref_offset(leaf, ref, offset); btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add); } else { num_refs = btrfs_extent_data_ref_count(leaf, ref); num_refs += refs_to_add; btrfs_set_extent_data_ref_count(leaf, ref, num_refs); } } btrfs_mark_buffer_dirty(leaf); ret = 0; fail: btrfs_release_path(path); return ret; } static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_path *path, int refs_to_drop, int *last_ref) { struct btrfs_key key; struct btrfs_extent_data_ref *ref1 = NULL; struct btrfs_shared_data_ref *ref2 = NULL; struct extent_buffer *leaf; u32 num_refs = 0; int ret = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { ref2 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); num_refs = btrfs_shared_data_ref_count(leaf, ref2); } else if (unlikely(key.type == BTRFS_EXTENT_REF_V0_KEY)) { btrfs_print_v0_err(trans->fs_info); btrfs_abort_transaction(trans, -EINVAL); return -EINVAL; } else { BUG(); } BUG_ON(num_refs < refs_to_drop); num_refs -= refs_to_drop; if (num_refs == 0) { ret = btrfs_del_item(trans, trans->fs_info->extent_root, path); *last_ref = 1; } else { if (key.type == BTRFS_EXTENT_DATA_REF_KEY) btrfs_set_extent_data_ref_count(leaf, ref1, num_refs); else if (key.type == BTRFS_SHARED_DATA_REF_KEY) btrfs_set_shared_data_ref_count(leaf, ref2, num_refs); btrfs_mark_buffer_dirty(leaf); } return ret; } static noinline u32 extent_data_ref_count(struct btrfs_path *path, struct btrfs_extent_inline_ref *iref) { struct btrfs_key key; struct extent_buffer *leaf; struct btrfs_extent_data_ref *ref1; struct btrfs_shared_data_ref *ref2; u32 num_refs = 0; int type; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); BUG_ON(key.type == BTRFS_EXTENT_REF_V0_KEY); if (iref) { /* * If type is invalid, we should have bailed out earlier than * this call. */ type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA); ASSERT(type != BTRFS_REF_TYPE_INVALID); if (type == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = (struct btrfs_extent_data_ref *)(&iref->offset); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else { ref2 = (struct btrfs_shared_data_ref *)(iref + 1); num_refs = btrfs_shared_data_ref_count(leaf, ref2); } } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { ref2 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); num_refs = btrfs_shared_data_ref_count(leaf, ref2); } else { WARN_ON(1); } return num_refs; } static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid) { struct btrfs_root *root = trans->fs_info->extent_root; struct btrfs_key key; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_BLOCK_REF_KEY; key.offset = parent; } else { key.type = BTRFS_TREE_BLOCK_REF_KEY; key.offset = root_objectid; } ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -ENOENT; return ret; } static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid) { struct btrfs_key key; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_BLOCK_REF_KEY; key.offset = parent; } else { key.type = BTRFS_TREE_BLOCK_REF_KEY; key.offset = root_objectid; } ret = btrfs_insert_empty_item(trans, trans->fs_info->extent_root, path, &key, 0); btrfs_release_path(path); return ret; } static inline int extent_ref_type(u64 parent, u64 owner) { int type; if (owner < BTRFS_FIRST_FREE_OBJECTID) { if (parent > 0) type = BTRFS_SHARED_BLOCK_REF_KEY; else type = BTRFS_TREE_BLOCK_REF_KEY; } else { if (parent > 0) type = BTRFS_SHARED_DATA_REF_KEY; else type = BTRFS_EXTENT_DATA_REF_KEY; } return type; } static int find_next_key(struct btrfs_path *path, int level, struct btrfs_key *key) { for (; level < BTRFS_MAX_LEVEL; level++) { if (!path->nodes[level]) break; if (path->slots[level] + 1 >= btrfs_header_nritems(path->nodes[level])) continue; if (level == 0) btrfs_item_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); else btrfs_node_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); return 0; } return 1; } /* * look for inline back ref. if back ref is found, *ref_ret is set * to the address of inline back ref, and 0 is returned. * * if back ref isn't found, *ref_ret is set to the address where it * should be inserted, and -ENOENT is returned. * * if insert is true and there are too many inline back refs, the path * points to the extent item, and -EAGAIN is returned. * * NOTE: inline back refs are ordered in the same way that back ref * items in the tree are ordered. */ static noinline_for_stack int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_path *path, struct btrfs_extent_inline_ref **ref_ret, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset, int insert) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root = fs_info->extent_root; struct btrfs_key key; struct extent_buffer *leaf; struct btrfs_extent_item *ei; struct btrfs_extent_inline_ref *iref; u64 flags; u64 item_size; unsigned long ptr; unsigned long end; int extra_size; int type; int want; int ret; int err = 0; bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); int needed; key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; want = extent_ref_type(parent, owner); if (insert) { extra_size = btrfs_extent_inline_ref_size(want); path->keep_locks = 1; } else extra_size = -1; /* * Owner is our level, so we can just add one to get the level for the * block we are interested in. */ if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) { key.type = BTRFS_METADATA_ITEM_KEY; key.offset = owner; } again: ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1); if (ret < 0) { err = ret; goto out; } /* * We may be a newly converted file system which still has the old fat * extent entries for metadata, so try and see if we have one of those. */ if (ret > 0 && skinny_metadata) { skinny_metadata = false; if (path->slots[0]) { path->slots[0]--; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid == bytenr && key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == num_bytes) ret = 0; } if (ret) { key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; btrfs_release_path(path); goto again; } } if (ret && !insert) { err = -ENOENT; goto out; } else if (WARN_ON(ret)) { err = -EIO; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); if (unlikely(item_size < sizeof(*ei))) { err = -EINVAL; btrfs_print_v0_err(fs_info); btrfs_abort_transaction(trans, err); goto out; } ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); flags = btrfs_extent_flags(leaf, ei); ptr = (unsigned long)(ei + 1); end = (unsigned long)ei + item_size; if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK && !skinny_metadata) { ptr += sizeof(struct btrfs_tree_block_info); BUG_ON(ptr > end); } if (owner >= BTRFS_FIRST_FREE_OBJECTID) needed = BTRFS_REF_TYPE_DATA; else needed = BTRFS_REF_TYPE_BLOCK; err = -ENOENT; while (1) { if (ptr >= end) { WARN_ON(ptr > end); break; } iref = (struct btrfs_extent_inline_ref *)ptr; type = btrfs_get_extent_inline_ref_type(leaf, iref, needed); if (type == BTRFS_REF_TYPE_INVALID) { err = -EUCLEAN; goto out; } if (want < type) break; if (want > type) { ptr += btrfs_extent_inline_ref_size(type); continue; } if (type == BTRFS_EXTENT_DATA_REF_KEY) { struct btrfs_extent_data_ref *dref; dref = (struct btrfs_extent_data_ref *)(&iref->offset); if (match_extent_data_ref(leaf, dref, root_objectid, owner, offset)) { err = 0; break; } if (hash_extent_data_ref_item(leaf, dref) < hash_extent_data_ref(root_objectid, owner, offset)) break; } else { u64 ref_offset; ref_offset = btrfs_extent_inline_ref_offset(leaf, iref); if (parent > 0) { if (parent == ref_offset) { err = 0; break; } if (ref_offset < parent) break; } else { if (root_objectid == ref_offset) { err = 0; break; } if (ref_offset < root_objectid) break; } } ptr += btrfs_extent_inline_ref_size(type); } if (err == -ENOENT && insert) { if (item_size + extra_size >= BTRFS_MAX_EXTENT_ITEM_SIZE(root)) { err = -EAGAIN; goto out; } /* * To add new inline back ref, we have to make sure * there is no corresponding back ref item. * For simplicity, we just do not add new inline back * ref if there is any kind of item for this block */ if (find_next_key(path, 0, &key) == 0 && key.objectid == bytenr && key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) { err = -EAGAIN; goto out; } } *ref_ret = (struct btrfs_extent_inline_ref *)ptr; out: if (insert) { path->keep_locks = 0; btrfs_unlock_up_safe(path, 1); } return err; } /* * helper to add new inline back ref */ static noinline_for_stack void setup_inline_extent_backref(struct btrfs_fs_info *fs_info, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct extent_buffer *leaf; struct btrfs_extent_item *ei; unsigned long ptr; unsigned long end; unsigned long item_offset; u64 refs; int size; int type; leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); item_offset = (unsigned long)iref - (unsigned long)ei; type = extent_ref_type(parent, owner); size = btrfs_extent_inline_ref_size(type); btrfs_extend_item(path, size); ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, ei); refs += refs_to_add; btrfs_set_extent_refs(leaf, ei, refs); if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); ptr = (unsigned long)ei + item_offset; end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]); if (ptr < end - size) memmove_extent_buffer(leaf, ptr + size, ptr, end - size - ptr); iref = (struct btrfs_extent_inline_ref *)ptr; btrfs_set_extent_inline_ref_type(leaf, iref, type); if (type == BTRFS_EXTENT_DATA_REF_KEY) { struct btrfs_extent_data_ref *dref; dref = (struct btrfs_extent_data_ref *)(&iref->offset); btrfs_set_extent_data_ref_root(leaf, dref, root_objectid); btrfs_set_extent_data_ref_objectid(leaf, dref, owner); btrfs_set_extent_data_ref_offset(leaf, dref, offset); btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add); } else if (type == BTRFS_SHARED_DATA_REF_KEY) { struct btrfs_shared_data_ref *sref; sref = (struct btrfs_shared_data_ref *)(iref + 1); btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add); btrfs_set_extent_inline_ref_offset(leaf, iref, parent); } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) { btrfs_set_extent_inline_ref_offset(leaf, iref, parent); } else { btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); } btrfs_mark_buffer_dirty(leaf); } static int lookup_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_path *path, struct btrfs_extent_inline_ref **ref_ret, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset) { int ret; ret = lookup_inline_extent_backref(trans, path, ref_ret, bytenr, num_bytes, parent, root_objectid, owner, offset, 0); if (ret != -ENOENT) return ret; btrfs_release_path(path); *ref_ret = NULL; if (owner < BTRFS_FIRST_FREE_OBJECTID) { ret = lookup_tree_block_ref(trans, path, bytenr, parent, root_objectid); } else { ret = lookup_extent_data_ref(trans, path, bytenr, parent, root_objectid, owner, offset); } return ret; } /* * helper to update/remove inline back ref */ static noinline_for_stack void update_inline_extent_backref(struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, int refs_to_mod, struct btrfs_delayed_extent_op *extent_op, int *last_ref) { struct extent_buffer *leaf = path->nodes[0]; struct btrfs_extent_item *ei; struct btrfs_extent_data_ref *dref = NULL; struct btrfs_shared_data_ref *sref = NULL; unsigned long ptr; unsigned long end; u32 item_size; int size; int type; u64 refs; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, ei); WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0); refs += refs_to_mod; btrfs_set_extent_refs(leaf, ei, refs); if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); /* * If type is invalid, we should have bailed out after * lookup_inline_extent_backref(). */ type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_ANY); ASSERT(type != BTRFS_REF_TYPE_INVALID); if (type == BTRFS_EXTENT_DATA_REF_KEY) { dref = (struct btrfs_extent_data_ref *)(&iref->offset); refs = btrfs_extent_data_ref_count(leaf, dref); } else if (type == BTRFS_SHARED_DATA_REF_KEY) { sref = (struct btrfs_shared_data_ref *)(iref + 1); refs = btrfs_shared_data_ref_count(leaf, sref); } else { refs = 1; BUG_ON(refs_to_mod != -1); } BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod); refs += refs_to_mod; if (refs > 0) { if (type == BTRFS_EXTENT_DATA_REF_KEY) btrfs_set_extent_data_ref_count(leaf, dref, refs); else btrfs_set_shared_data_ref_count(leaf, sref, refs); } else { *last_ref = 1; size = btrfs_extent_inline_ref_size(type); item_size = btrfs_item_size_nr(leaf, path->slots[0]); ptr = (unsigned long)iref; end = (unsigned long)ei + item_size; if (ptr + size < end) memmove_extent_buffer(leaf, ptr, ptr + size, end - ptr - size); item_size -= size; btrfs_truncate_item(path, item_size, 1); } btrfs_mark_buffer_dirty(leaf); } static noinline_for_stack int insert_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_extent_inline_ref *iref; int ret; ret = lookup_inline_extent_backref(trans, path, &iref, bytenr, num_bytes, parent, root_objectid, owner, offset, 1); if (ret == 0) { BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID); update_inline_extent_backref(path, iref, refs_to_add, extent_op, NULL); } else if (ret == -ENOENT) { setup_inline_extent_backref(trans->fs_info, path, iref, parent, root_objectid, owner, offset, refs_to_add, extent_op); ret = 0; } return ret; } static int insert_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add) { int ret; if (owner < BTRFS_FIRST_FREE_OBJECTID) { BUG_ON(refs_to_add != 1); ret = insert_tree_block_ref(trans, path, bytenr, parent, root_objectid); } else { ret = insert_extent_data_ref(trans, path, bytenr, parent, root_objectid, owner, offset, refs_to_add); } return ret; } static int remove_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, int refs_to_drop, int is_data, int *last_ref) { int ret = 0; BUG_ON(!is_data && refs_to_drop != 1); if (iref) { update_inline_extent_backref(path, iref, -refs_to_drop, NULL, last_ref); } else if (is_data) { ret = remove_extent_data_ref(trans, path, refs_to_drop, last_ref); } else { *last_ref = 1; ret = btrfs_del_item(trans, trans->fs_info->extent_root, path); } return ret; } static int btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len, u64 *discarded_bytes) { int j, ret = 0; u64 bytes_left, end; u64 aligned_start = ALIGN(start, 1 << 9); if (WARN_ON(start != aligned_start)) { len -= aligned_start - start; len = round_down(len, 1 << 9); start = aligned_start; } *discarded_bytes = 0; if (!len) return 0; end = start + len; bytes_left = len; /* Skip any superblocks on this device. */ for (j = 0; j < BTRFS_SUPER_MIRROR_MAX; j++) { u64 sb_start = btrfs_sb_offset(j); u64 sb_end = sb_start + BTRFS_SUPER_INFO_SIZE; u64 size = sb_start - start; if (!in_range(sb_start, start, bytes_left) && !in_range(sb_end, start, bytes_left) && !in_range(start, sb_start, BTRFS_SUPER_INFO_SIZE)) continue; /* * Superblock spans beginning of range. Adjust start and * try again. */ if (sb_start <= start) { start += sb_end - start; if (start > end) { bytes_left = 0; break; } bytes_left = end - start; continue; } if (size) { ret = blkdev_issue_discard(bdev, start >> 9, size >> 9, GFP_NOFS, 0); if (!ret) *discarded_bytes += size; else if (ret != -EOPNOTSUPP) return ret; } start = sb_end; if (start > end) { bytes_left = 0; break; } bytes_left = end - start; } if (bytes_left) { ret = blkdev_issue_discard(bdev, start >> 9, bytes_left >> 9, GFP_NOFS, 0); if (!ret) *discarded_bytes += bytes_left; } return ret; } int btrfs_discard_extent(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes, u64 *actual_bytes) { int ret; u64 discarded_bytes = 0; struct btrfs_bio *bbio = NULL; /* * Avoid races with device replace and make sure our bbio has devices * associated to its stripes that don't go away while we are discarding. */ btrfs_bio_counter_inc_blocked(fs_info); /* Tell the block device(s) that the sectors can be discarded */ ret = btrfs_map_block(fs_info, BTRFS_MAP_DISCARD, bytenr, &num_bytes, &bbio, 0); /* Error condition is -ENOMEM */ if (!ret) { struct btrfs_bio_stripe *stripe = bbio->stripes; int i; for (i = 0; i < bbio->num_stripes; i++, stripe++) { u64 bytes; struct request_queue *req_q; if (!stripe->dev->bdev) { ASSERT(btrfs_test_opt(fs_info, DEGRADED)); continue; } req_q = bdev_get_queue(stripe->dev->bdev); if (!blk_queue_discard(req_q)) continue; ret = btrfs_issue_discard(stripe->dev->bdev, stripe->physical, stripe->length, &bytes); if (!ret) discarded_bytes += bytes; else if (ret != -EOPNOTSUPP) break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */ /* * Just in case we get back EOPNOTSUPP for some reason, * just ignore the return value so we don't screw up * people calling discard_extent. */ ret = 0; } btrfs_put_bbio(bbio); } btrfs_bio_counter_dec(fs_info); if (actual_bytes) *actual_bytes = discarded_bytes; if (ret == -EOPNOTSUPP) ret = 0; return ret; } /* Can return -ENOMEM */ int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_ref *generic_ref) { struct btrfs_fs_info *fs_info = trans->fs_info; int old_ref_mod, new_ref_mod; int ret; ASSERT(generic_ref->type != BTRFS_REF_NOT_SET && generic_ref->action); BUG_ON(generic_ref->type == BTRFS_REF_METADATA && generic_ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID); if (generic_ref->type == BTRFS_REF_METADATA) ret = btrfs_add_delayed_tree_ref(trans, generic_ref, NULL, &old_ref_mod, &new_ref_mod); else ret = btrfs_add_delayed_data_ref(trans, generic_ref, 0, &old_ref_mod, &new_ref_mod); btrfs_ref_tree_mod(fs_info, generic_ref); if (ret == 0 && old_ref_mod < 0 && new_ref_mod >= 0) sub_pinned_bytes(fs_info, generic_ref); return ret; } /* * __btrfs_inc_extent_ref - insert backreference for a given extent * * @trans: Handle of transaction * * @node: The delayed ref node used to get the bytenr/length for * extent whose references are incremented. * * @parent: If this is a shared extent (BTRFS_SHARED_DATA_REF_KEY/ * BTRFS_SHARED_BLOCK_REF_KEY) then it holds the logical * bytenr of the parent block. Since new extents are always * created with indirect references, this will only be the case * when relocating a shared extent. In that case, root_objectid * will be BTRFS_TREE_RELOC_OBJECTID. Otheriwse, parent must * be 0 * * @root_objectid: The id of the root where this modification has originated, * this can be either one of the well-known metadata trees or * the subvolume id which references this extent. * * @owner: For data extents it is the inode number of the owning file. * For metadata extents this parameter holds the level in the * tree of the extent. * * @offset: For metadata extents the offset is ignored and is currently * always passed as 0. For data extents it is the fileoffset * this extent belongs to. * * @refs_to_add Number of references to add * * @extent_op Pointer to a structure, holding information necessary when * updating a tree block's flags * */ static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_extent_item *item; struct btrfs_key key; u64 bytenr = node->bytenr; u64 num_bytes = node->num_bytes; u64 refs; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; path->leave_spinning = 1; /* this will setup the path even if it fails to insert the back ref */ ret = insert_inline_extent_backref(trans, path, bytenr, num_bytes, parent, root_objectid, owner, offset, refs_to_add, extent_op); if ((ret < 0 && ret != -EAGAIN) || !ret) goto out; /* * Ok we had -EAGAIN which means we didn't have space to insert and * inline extent ref, so just update the reference count and add a * normal backref. */ leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, item); btrfs_set_extent_refs(leaf, item, refs + refs_to_add); if (extent_op) __run_delayed_extent_op(extent_op, leaf, item); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(path); path->reada = READA_FORWARD; path->leave_spinning = 1; /* now insert the actual backref */ ret = insert_extent_backref(trans, path, bytenr, parent, root_objectid, owner, offset, refs_to_add); if (ret) btrfs_abort_transaction(trans, ret); out: btrfs_free_path(path); return ret; } static int run_delayed_data_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret = 0; struct btrfs_delayed_data_ref *ref; struct btrfs_key ins; u64 parent = 0; u64 ref_root = 0; u64 flags = 0; ins.objectid = node->bytenr; ins.offset = node->num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ref = btrfs_delayed_node_to_data_ref(node); trace_run_delayed_data_ref(trans->fs_info, node, ref, node->action); if (node->type == BTRFS_SHARED_DATA_REF_KEY) parent = ref->parent; ref_root = ref->root; if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { if (extent_op) flags |= extent_op->flags_to_set; ret = alloc_reserved_file_extent(trans, parent, ref_root, flags, ref->objectid, ref->offset, &ins, node->ref_mod); } else if (node->action == BTRFS_ADD_DELAYED_REF) { ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root, ref->objectid, ref->offset, node->ref_mod, extent_op); } else if (node->action == BTRFS_DROP_DELAYED_REF) { ret = __btrfs_free_extent(trans, node, parent, ref_root, ref->objectid, ref->offset, node->ref_mod, extent_op); } else { BUG(); } return ret; } static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, struct extent_buffer *leaf, struct btrfs_extent_item *ei) { u64 flags = btrfs_extent_flags(leaf, ei); if (extent_op->update_flags) { flags |= extent_op->flags_to_set; btrfs_set_extent_flags(leaf, ei, flags); } if (extent_op->update_key) { struct btrfs_tree_block_info *bi; BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); bi = (struct btrfs_tree_block_info *)(ei + 1); btrfs_set_tree_block_key(leaf, bi, &extent_op->key); } } static int run_delayed_extent_op(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_key key; struct btrfs_path *path; struct btrfs_extent_item *ei; struct extent_buffer *leaf; u32 item_size; int ret; int err = 0; int metadata = !extent_op->is_data; if (trans->aborted) return 0; if (metadata && !btrfs_fs_incompat(fs_info, SKINNY_METADATA)) metadata = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = head->bytenr; if (metadata) { key.type = BTRFS_METADATA_ITEM_KEY; key.offset = extent_op->level; } else { key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = head->num_bytes; } again: path->reada = READA_FORWARD; path->leave_spinning = 1; ret = btrfs_search_slot(trans, fs_info->extent_root, &key, path, 0, 1); if (ret < 0) { err = ret; goto out; } if (ret > 0) { if (metadata) { if (path->slots[0] > 0) { path->slots[0]--; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid == head->bytenr && key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == head->num_bytes) ret = 0; } if (ret > 0) { btrfs_release_path(path); metadata = 0; key.objectid = head->bytenr; key.offset = head->num_bytes; key.type = BTRFS_EXTENT_ITEM_KEY; goto again; } } else { err = -EIO; goto out; } } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); if (unlikely(item_size < sizeof(*ei))) { err = -EINVAL; btrfs_print_v0_err(fs_info); btrfs_abort_transaction(trans, err); goto out; } ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); __run_delayed_extent_op(extent_op, leaf, ei); btrfs_mark_buffer_dirty(leaf); out: btrfs_free_path(path); return err; } static int run_delayed_tree_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret = 0; struct btrfs_delayed_tree_ref *ref; u64 parent = 0; u64 ref_root = 0; ref = btrfs_delayed_node_to_tree_ref(node); trace_run_delayed_tree_ref(trans->fs_info, node, ref, node->action); if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) parent = ref->parent; ref_root = ref->root; if (node->ref_mod != 1) { btrfs_err(trans->fs_info, "btree block(%llu) has %d references rather than 1: action %d ref_root %llu parent %llu", node->bytenr, node->ref_mod, node->action, ref_root, parent); return -EIO; } if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { BUG_ON(!extent_op || !extent_op->update_flags); ret = alloc_reserved_tree_block(trans, node, extent_op); } else if (node->action == BTRFS_ADD_DELAYED_REF) { ret = __btrfs_inc_extent_ref(trans, node, parent, ref_root, ref->level, 0, 1, extent_op); } else if (node->action == BTRFS_DROP_DELAYED_REF) { ret = __btrfs_free_extent(trans, node, parent, ref_root, ref->level, 0, 1, extent_op); } else { BUG(); } return ret; } /* helper function to actually process a single delayed ref entry */ static int run_one_delayed_ref(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret = 0; if (trans->aborted) { if (insert_reserved) btrfs_pin_extent(trans->fs_info, node->bytenr, node->num_bytes, 1); return 0; } if (node->type == BTRFS_TREE_BLOCK_REF_KEY || node->type == BTRFS_SHARED_BLOCK_REF_KEY) ret = run_delayed_tree_ref(trans, node, extent_op, insert_reserved); else if (node->type == BTRFS_EXTENT_DATA_REF_KEY || node->type == BTRFS_SHARED_DATA_REF_KEY) ret = run_delayed_data_ref(trans, node, extent_op, insert_reserved); else BUG(); if (ret && insert_reserved) btrfs_pin_extent(trans->fs_info, node->bytenr, node->num_bytes, 1); return ret; } static inline struct btrfs_delayed_ref_node * select_delayed_ref(struct btrfs_delayed_ref_head *head) { struct btrfs_delayed_ref_node *ref; if (RB_EMPTY_ROOT(&head->ref_tree.rb_root)) return NULL; /* * Select a delayed ref of type BTRFS_ADD_DELAYED_REF first. * This is to prevent a ref count from going down to zero, which deletes * the extent item from the extent tree, when there still are references * to add, which would fail because they would not find the extent item. */ if (!list_empty(&head->ref_add_list)) return list_first_entry(&head->ref_add_list, struct btrfs_delayed_ref_node, add_list); ref = rb_entry(rb_first_cached(&head->ref_tree), struct btrfs_delayed_ref_node, ref_node); ASSERT(list_empty(&ref->add_list)); return ref; } static void unselect_delayed_ref_head(struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head) { spin_lock(&delayed_refs->lock); head->processing = 0; delayed_refs->num_heads_ready++; spin_unlock(&delayed_refs->lock); btrfs_delayed_ref_unlock(head); } static struct btrfs_delayed_extent_op *cleanup_extent_op( struct btrfs_delayed_ref_head *head) { struct btrfs_delayed_extent_op *extent_op = head->extent_op; if (!extent_op) return NULL; if (head->must_insert_reserved) { head->extent_op = NULL; btrfs_free_delayed_extent_op(extent_op); return NULL; } return extent_op; } static int run_and_cleanup_extent_op(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head) { struct btrfs_delayed_extent_op *extent_op; int ret; extent_op = cleanup_extent_op(head); if (!extent_op) return 0; head->extent_op = NULL; spin_unlock(&head->lock); ret = run_delayed_extent_op(trans, head, extent_op); btrfs_free_delayed_extent_op(extent_op); return ret ? ret : 1; } void btrfs_cleanup_ref_head_accounting(struct btrfs_fs_info *fs_info, struct btrfs_delayed_ref_root *delayed_refs, struct btrfs_delayed_ref_head *head) { int nr_items = 1; /* Dropping this ref head update. */ if (head->total_ref_mod < 0) { struct btrfs_space_info *space_info; u64 flags; if (head->is_data) flags = BTRFS_BLOCK_GROUP_DATA; else if (head->is_system) flags = BTRFS_BLOCK_GROUP_SYSTEM; else flags = BTRFS_BLOCK_GROUP_METADATA; space_info = btrfs_find_space_info(fs_info, flags); ASSERT(space_info); percpu_counter_add_batch(&space_info->total_bytes_pinned, -head->num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH); /* * We had csum deletions accounted for in our delayed refs rsv, * we need to drop the csum leaves for this update from our * delayed_refs_rsv. */ if (head->is_data) { spin_lock(&delayed_refs->lock); delayed_refs->pending_csums -= head->num_bytes; spin_unlock(&delayed_refs->lock); nr_items += btrfs_csum_bytes_to_leaves(fs_info, head->num_bytes); } } btrfs_delayed_refs_rsv_release(fs_info, nr_items); } static int cleanup_ref_head(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *head) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_ref_root *delayed_refs; int ret; delayed_refs = &trans->transaction->delayed_refs; ret = run_and_cleanup_extent_op(trans, head); if (ret < 0) { unselect_delayed_ref_head(delayed_refs, head); btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); return ret; } else if (ret) { return ret; } /* * Need to drop our head ref lock and re-acquire the delayed ref lock * and then re-check to make sure nobody got added. */ spin_unlock(&head->lock); spin_lock(&delayed_refs->lock); spin_lock(&head->lock); if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root) || head->extent_op) { spin_unlock(&head->lock); spin_unlock(&delayed_refs->lock); return 1; } btrfs_delete_ref_head(delayed_refs, head); spin_unlock(&head->lock); spin_unlock(&delayed_refs->lock); if (head->must_insert_reserved) { btrfs_pin_extent(fs_info, head->bytenr, head->num_bytes, 1); if (head->is_data) { ret = btrfs_del_csums(trans, fs_info, head->bytenr, head->num_bytes); } } btrfs_cleanup_ref_head_accounting(fs_info, delayed_refs, head); trace_run_delayed_ref_head(fs_info, head, 0); btrfs_delayed_ref_unlock(head); btrfs_put_delayed_ref_head(head); return 0; } static struct btrfs_delayed_ref_head *btrfs_obtain_ref_head( struct btrfs_trans_handle *trans) { struct btrfs_delayed_ref_root *delayed_refs = &trans->transaction->delayed_refs; struct btrfs_delayed_ref_head *head = NULL; int ret; spin_lock(&delayed_refs->lock); head = btrfs_select_ref_head(delayed_refs); if (!head) { spin_unlock(&delayed_refs->lock); return head; } /* * Grab the lock that says we are going to process all the refs for * this head */ ret = btrfs_delayed_ref_lock(delayed_refs, head); spin_unlock(&delayed_refs->lock); /* * We may have dropped the spin lock to get the head mutex lock, and * that might have given someone else time to free the head. If that's * true, it has been removed from our list and we can move on. */ if (ret == -EAGAIN) head = ERR_PTR(-EAGAIN); return head; } static int btrfs_run_delayed_refs_for_head(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_head *locked_ref, unsigned long *run_refs) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_extent_op *extent_op; struct btrfs_delayed_ref_node *ref; int must_insert_reserved = 0; int ret; delayed_refs = &trans->transaction->delayed_refs; lockdep_assert_held(&locked_ref->mutex); lockdep_assert_held(&locked_ref->lock); while ((ref = select_delayed_ref(locked_ref))) { if (ref->seq && btrfs_check_delayed_seq(fs_info, ref->seq)) { spin_unlock(&locked_ref->lock); unselect_delayed_ref_head(delayed_refs, locked_ref); return -EAGAIN; } (*run_refs)++; ref->in_tree = 0; rb_erase_cached(&ref->ref_node, &locked_ref->ref_tree); RB_CLEAR_NODE(&ref->ref_node); if (!list_empty(&ref->add_list)) list_del(&ref->add_list); /* * When we play the delayed ref, also correct the ref_mod on * head */ switch (ref->action) { case BTRFS_ADD_DELAYED_REF: case BTRFS_ADD_DELAYED_EXTENT: locked_ref->ref_mod -= ref->ref_mod; break; case BTRFS_DROP_DELAYED_REF: locked_ref->ref_mod += ref->ref_mod; break; default: WARN_ON(1); } atomic_dec(&delayed_refs->num_entries); /* * Record the must_insert_reserved flag before we drop the * spin lock. */ must_insert_reserved = locked_ref->must_insert_reserved; locked_ref->must_insert_reserved = 0; extent_op = locked_ref->extent_op; locked_ref->extent_op = NULL; spin_unlock(&locked_ref->lock); ret = run_one_delayed_ref(trans, ref, extent_op, must_insert_reserved); btrfs_free_delayed_extent_op(extent_op); if (ret) { unselect_delayed_ref_head(delayed_refs, locked_ref); btrfs_put_delayed_ref(ref); btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret); return ret; } btrfs_put_delayed_ref(ref); cond_resched(); spin_lock(&locked_ref->lock); btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref); } return 0; } /* * Returns 0 on success or if called with an already aborted transaction. * Returns -ENOMEM or -EIO on failure and will abort the transaction. */ static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, unsigned long nr) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_head *locked_ref = NULL; ktime_t start = ktime_get(); int ret; unsigned long count = 0; unsigned long actual_count = 0; delayed_refs = &trans->transaction->delayed_refs; do { if (!locked_ref) { locked_ref = btrfs_obtain_ref_head(trans); if (IS_ERR_OR_NULL(locked_ref)) { if (PTR_ERR(locked_ref) == -EAGAIN) { continue; } else { break; } } count++; } /* * We need to try and merge add/drops of the same ref since we * can run into issues with relocate dropping the implicit ref * and then it being added back again before the drop can * finish. If we merged anything we need to re-loop so we can * get a good ref. * Or we can get node references of the same type that weren't * merged when created due to bumps in the tree mod seq, and * we need to merge them to prevent adding an inline extent * backref before dropping it (triggering a BUG_ON at * insert_inline_extent_backref()). */ spin_lock(&locked_ref->lock); btrfs_merge_delayed_refs(trans, delayed_refs, locked_ref); ret = btrfs_run_delayed_refs_for_head(trans, locked_ref, &actual_count); if (ret < 0 && ret != -EAGAIN) { /* * Error, btrfs_run_delayed_refs_for_head already * unlocked everything so just bail out */ return ret; } else if (!ret) { /* * Success, perform the usual cleanup of a processed * head */ ret = cleanup_ref_head(trans, locked_ref); if (ret > 0 ) { /* We dropped our lock, we need to loop. */ ret = 0; continue; } else if (ret) { return ret; } } /* * Either success case or btrfs_run_delayed_refs_for_head * returned -EAGAIN, meaning we need to select another head */ locked_ref = NULL; cond_resched(); } while ((nr != -1 && count < nr) || locked_ref); /* * We don't want to include ref heads since we can have empty ref heads * and those will drastically skew our runtime down since we just do * accounting, no actual extent tree updates. */ if (actual_count > 0) { u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start)); u64 avg; /* * We weigh the current average higher than our current runtime * to avoid large swings in the average. */ spin_lock(&delayed_refs->lock); avg = fs_info->avg_delayed_ref_runtime * 3 + runtime; fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */ spin_unlock(&delayed_refs->lock); } return 0; } #ifdef SCRAMBLE_DELAYED_REFS /* * Normally delayed refs get processed in ascending bytenr order. This * correlates in most cases to the order added. To expose dependencies on this * order, we start to process the tree in the middle instead of the beginning */ static u64 find_middle(struct rb_root *root) { struct rb_node *n = root->rb_node; struct btrfs_delayed_ref_node *entry; int alt = 1; u64 middle; u64 first = 0, last = 0; n = rb_first(root); if (n) { entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); first = entry->bytenr; } n = rb_last(root); if (n) { entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); last = entry->bytenr; } n = root->rb_node; while (n) { entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); WARN_ON(!entry->in_tree); middle = entry->bytenr; if (alt) n = n->rb_left; else n = n->rb_right; alt = 1 - alt; } return middle; } #endif static inline u64 heads_to_leaves(struct btrfs_fs_info *fs_info, u64 heads) { u64 num_bytes; num_bytes = heads * (sizeof(struct btrfs_extent_item) + sizeof(struct btrfs_extent_inline_ref)); if (!btrfs_fs_incompat(fs_info, SKINNY_METADATA)) num_bytes += heads * sizeof(struct btrfs_tree_block_info); /* * We don't ever fill up leaves all the way so multiply by 2 just to be * closer to what we're really going to want to use. */ return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(fs_info)); } /* * Takes the number of bytes to be csumm'ed and figures out how many leaves it * would require to store the csums for that many bytes. */ u64 btrfs_csum_bytes_to_leaves(struct btrfs_fs_info *fs_info, u64 csum_bytes) { u64 csum_size; u64 num_csums_per_leaf; u64 num_csums; csum_size = BTRFS_MAX_ITEM_SIZE(fs_info); num_csums_per_leaf = div64_u64(csum_size, (u64)btrfs_super_csum_size(fs_info->super_copy)); num_csums = div64_u64(csum_bytes, fs_info->sectorsize); num_csums += num_csums_per_leaf - 1; num_csums = div64_u64(num_csums, num_csums_per_leaf); return num_csums; } /* * this starts processing the delayed reference count updates and * extent insertions we have queued up so far. count can be * 0, which means to process everything in the tree at the start * of the run (but not newly added entries), or it can be some target * number you'd like to process. * * Returns 0 on success or if called with an aborted transaction * Returns <0 on error and aborts the transaction */ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, unsigned long count) { struct btrfs_fs_info *fs_info = trans->fs_info; struct rb_node *node; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_head *head; int ret; int run_all = count == (unsigned long)-1; /* We'll clean this up in btrfs_cleanup_transaction */ if (trans->aborted) return 0; if (test_bit(BTRFS_FS_CREATING_FREE_SPACE_TREE, &fs_info->flags)) return 0; delayed_refs = &trans->transaction->delayed_refs; if (count == 0) count = atomic_read(&delayed_refs->num_entries) * 2; again: #ifdef SCRAMBLE_DELAYED_REFS delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); #endif ret = __btrfs_run_delayed_refs(trans, count); if (ret < 0) { btrfs_abort_transaction(trans, ret); return ret; } if (run_all) { btrfs_create_pending_block_groups(trans); spin_lock(&delayed_refs->lock); node = rb_first_cached(&delayed_refs->href_root); if (!node) { spin_unlock(&delayed_refs->lock); goto out; } head = rb_entry(node, struct btrfs_delayed_ref_head, href_node); refcount_inc(&head->refs); spin_unlock(&delayed_refs->lock); /* Mutex was contended, block until it's released and retry. */ mutex_lock(&head->mutex); mutex_unlock(&head->mutex); btrfs_put_delayed_ref_head(head); cond_resched(); goto again; } out: return 0; } int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, u64 flags, int level, int is_data) { struct btrfs_delayed_extent_op *extent_op; int ret; extent_op = btrfs_alloc_delayed_extent_op(); if (!extent_op) return -ENOMEM; extent_op->flags_to_set = flags; extent_op->update_flags = true; extent_op->update_key = false; extent_op->is_data = is_data ? true : false; extent_op->level = level; ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op); if (ret) btrfs_free_delayed_extent_op(extent_op); return ret; } static noinline int check_delayed_ref(struct btrfs_root *root, struct btrfs_path *path, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_delayed_ref_head *head; struct btrfs_delayed_ref_node *ref; struct btrfs_delayed_data_ref *data_ref; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_transaction *cur_trans; struct rb_node *node; int ret = 0; spin_lock(&root->fs_info->trans_lock); cur_trans = root->fs_info->running_transaction; if (cur_trans) refcount_inc(&cur_trans->use_count); spin_unlock(&root->fs_info->trans_lock); if (!cur_trans) return 0; delayed_refs = &cur_trans->delayed_refs; spin_lock(&delayed_refs->lock); head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); if (!head) { spin_unlock(&delayed_refs->lock); btrfs_put_transaction(cur_trans); return 0; } if (!mutex_trylock(&head->mutex)) { refcount_inc(&head->refs); spin_unlock(&delayed_refs->lock); btrfs_release_path(path); /* * Mutex was contended, block until it's released and let * caller try again */ mutex_lock(&head->mutex); mutex_unlock(&head->mutex); btrfs_put_delayed_ref_head(head); btrfs_put_transaction(cur_trans); return -EAGAIN; } spin_unlock(&delayed_refs->lock); spin_lock(&head->lock); /* * XXX: We should replace this with a proper search function in the * future. */ for (node = rb_first_cached(&head->ref_tree); node; node = rb_next(node)) { ref = rb_entry(node, struct btrfs_delayed_ref_node, ref_node); /* If it's a shared ref we know a cross reference exists */ if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) { ret = 1; break; } data_ref = btrfs_delayed_node_to_data_ref(ref); /* * If our ref doesn't match the one we're currently looking at * then we have a cross reference. */ if (data_ref->root != root->root_key.objectid || data_ref->objectid != objectid || data_ref->offset != offset) { ret = 1; break; } } spin_unlock(&head->lock); mutex_unlock(&head->mutex); btrfs_put_transaction(cur_trans); return ret; } static noinline int check_committed_ref(struct btrfs_root *root, struct btrfs_path *path, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_root *extent_root = fs_info->extent_root; struct extent_buffer *leaf; struct btrfs_extent_data_ref *ref; struct btrfs_extent_inline_ref *iref; struct btrfs_extent_item *ei; struct btrfs_key key; u32 item_size; int type; int ret; key.objectid = bytenr; key.offset = (u64)-1; key.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(ret == 0); /* Corruption */ ret = -ENOENT; if (path->slots[0] == 0) goto out; path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY) goto out; ret = 1; item_size = btrfs_item_size_nr(leaf, path->slots[0]); ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); if (item_size != sizeof(*ei) + btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY)) goto out; if (btrfs_extent_generation(leaf, ei) <= btrfs_root_last_snapshot(&root->root_item)) goto out; iref = (struct btrfs_extent_inline_ref *)(ei + 1); type = btrfs_get_extent_inline_ref_type(leaf, iref, BTRFS_REF_TYPE_DATA); if (type != BTRFS_EXTENT_DATA_REF_KEY) goto out; ref = (struct btrfs_extent_data_ref *)(&iref->offset); if (btrfs_extent_refs(leaf, ei) != btrfs_extent_data_ref_count(leaf, ref) || btrfs_extent_data_ref_root(leaf, ref) != root->root_key.objectid || btrfs_extent_data_ref_objectid(leaf, ref) != objectid || btrfs_extent_data_ref_offset(leaf, ref) != offset) goto out; ret = 0; out: return ret; } int btrfs_cross_ref_exist(struct btrfs_root *root, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_path *path; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; do { ret = check_committed_ref(root, path, objectid, offset, bytenr); if (ret && ret != -ENOENT) goto out; ret = check_delayed_ref(root, path, objectid, offset, bytenr); } while (ret == -EAGAIN); out: btrfs_free_path(path); if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) WARN_ON(ret > 0); return ret; } static int __btrfs_mod_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref, int inc) { struct btrfs_fs_info *fs_info = root->fs_info; u64 bytenr; u64 num_bytes; u64 parent; u64 ref_root; u32 nritems; struct btrfs_key key; struct btrfs_file_extent_item *fi; struct btrfs_ref generic_ref = { 0 }; bool for_reloc = btrfs_header_flag(buf, BTRFS_HEADER_FLAG_RELOC); int i; int action; int level; int ret = 0; if (btrfs_is_testing(fs_info)) return 0; ref_root = btrfs_header_owner(buf); nritems = btrfs_header_nritems(buf); level = btrfs_header_level(buf); if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0) return 0; if (full_backref) parent = buf->start; else parent = 0; if (inc) action = BTRFS_ADD_DELAYED_REF; else action = BTRFS_DROP_DELAYED_REF; for (i = 0; i < nritems; i++) { if (level == 0) { btrfs_item_key_to_cpu(buf, &key, i); if (key.type != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (bytenr == 0) continue; num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); key.offset -= btrfs_file_extent_offset(buf, fi); btrfs_init_generic_ref(&generic_ref, action, bytenr, num_bytes, parent); generic_ref.real_root = root->root_key.objectid; btrfs_init_data_ref(&generic_ref, ref_root, key.objectid, key.offset); generic_ref.skip_qgroup = for_reloc; if (inc) ret = btrfs_inc_extent_ref(trans, &generic_ref); else ret = btrfs_free_extent(trans, &generic_ref); if (ret) goto fail; } else { bytenr = btrfs_node_blockptr(buf, i); num_bytes = fs_info->nodesize; btrfs_init_generic_ref(&generic_ref, action, bytenr, num_bytes, parent); generic_ref.real_root = root->root_key.objectid; btrfs_init_tree_ref(&generic_ref, level - 1, ref_root); generic_ref.skip_qgroup = for_reloc; if (inc) ret = btrfs_inc_extent_ref(trans, &generic_ref); else ret = btrfs_free_extent(trans, &generic_ref); if (ret) goto fail; } } return 0; fail: return ret; } int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref) { return __btrfs_mod_ref(trans, root, buf, full_backref, 1); } int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref) { return __btrfs_mod_ref(trans, root, buf, full_backref, 0); } static int write_one_cache_group(struct btrfs_trans_handle *trans, struct btrfs_path *path, struct btrfs_block_group_cache *cache) { struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_root *extent_root = fs_info->extent_root; unsigned long bi; struct extent_buffer *leaf; ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); if (ret) { if (ret > 0) ret = -ENOENT; goto fail; } leaf = path->nodes[0]; bi = btrfs_item_ptr_offset(leaf, path->slots[0]); write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); btrfs_mark_buffer_dirty(leaf); fail: btrfs_release_path(path); return ret; } static int cache_save_setup(struct btrfs_block_group_cache *block_group, struct btrfs_trans_handle *trans, struct btrfs_path *path) { struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_root *root = fs_info->tree_root; struct inode *inode = NULL; struct extent_changeset *data_reserved = NULL; u64 alloc_hint = 0; int dcs = BTRFS_DC_ERROR; u64 num_pages = 0; int retries = 0; int ret = 0; /* * If this block group is smaller than 100 megs don't bother caching the * block group. */ if (block_group->key.offset < (100 * SZ_1M)) { spin_lock(&block_group->lock); block_group->disk_cache_state = BTRFS_DC_WRITTEN; spin_unlock(&block_group->lock); return 0; } if (trans->aborted) return 0; again: inode = lookup_free_space_inode(block_group, path); if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { ret = PTR_ERR(inode); btrfs_release_path(path); goto out; } if (IS_ERR(inode)) { BUG_ON(retries); retries++; if (block_group->ro) goto out_free; ret = create_free_space_inode(trans, block_group, path); if (ret) goto out_free; goto again; } /* * We want to set the generation to 0, that way if anything goes wrong * from here on out we know not to trust this cache when we load up next * time. */ BTRFS_I(inode)->generation = 0; ret = btrfs_update_inode(trans, root, inode); if (ret) { /* * So theoretically we could recover from this, simply set the * super cache generation to 0 so we know to invalidate the * cache, but then we'd have to keep track of the block groups * that fail this way so we know we _have_ to reset this cache * before the next commit or risk reading stale cache. So to * limit our exposure to horrible edge cases lets just abort the * transaction, this only happens in really bad situations * anyway. */ btrfs_abort_transaction(trans, ret); goto out_put; } WARN_ON(ret); /* We've already setup this transaction, go ahead and exit */ if (block_group->cache_generation == trans->transid && i_size_read(inode)) { dcs = BTRFS_DC_SETUP; goto out_put; } if (i_size_read(inode) > 0) { ret = btrfs_check_trunc_cache_free_space(fs_info, &fs_info->global_block_rsv); if (ret) goto out_put; ret = btrfs_truncate_free_space_cache(trans, NULL, inode); if (ret) goto out_put; } spin_lock(&block_group->lock); if (block_group->cached != BTRFS_CACHE_FINISHED || !btrfs_test_opt(fs_info, SPACE_CACHE)) { /* * don't bother trying to write stuff out _if_ * a) we're not cached, * b) we're with nospace_cache mount option, * c) we're with v2 space_cache (FREE_SPACE_TREE). */ dcs = BTRFS_DC_WRITTEN; spin_unlock(&block_group->lock); goto out_put; } spin_unlock(&block_group->lock); /* * We hit an ENOSPC when setting up the cache in this transaction, just * skip doing the setup, we've already cleared the cache so we're safe. */ if (test_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags)) { ret = -ENOSPC; goto out_put; } /* * Try to preallocate enough space based on how big the block group is. * Keep in mind this has to include any pinned space which could end up * taking up quite a bit since it's not folded into the other space * cache. */ num_pages = div_u64(block_group->key.offset, SZ_256M); if (!num_pages) num_pages = 1; num_pages *= 16; num_pages *= PAGE_SIZE; ret = btrfs_check_data_free_space(inode, &data_reserved, 0, num_pages); if (ret) goto out_put; ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages, num_pages, num_pages, &alloc_hint); /* * Our cache requires contiguous chunks so that we don't modify a bunch * of metadata or split extents when writing the cache out, which means * we can enospc if we are heavily fragmented in addition to just normal * out of space conditions. So if we hit this just skip setting up any * other block groups for this transaction, maybe we'll unpin enough * space the next time around. */ if (!ret) dcs = BTRFS_DC_SETUP; else if (ret == -ENOSPC) set_bit(BTRFS_TRANS_CACHE_ENOSPC, &trans->transaction->flags); out_put: iput(inode); out_free: btrfs_release_path(path); out: spin_lock(&block_group->lock); if (!ret && dcs == BTRFS_DC_SETUP) block_group->cache_generation = trans->transid; block_group->disk_cache_state = dcs; spin_unlock(&block_group->lock); extent_changeset_free(data_reserved); return ret; } int btrfs_setup_space_cache(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *cache, *tmp; struct btrfs_transaction *cur_trans = trans->transaction; struct btrfs_path *path; if (list_empty(&cur_trans->dirty_bgs) || !btrfs_test_opt(fs_info, SPACE_CACHE)) return 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* Could add new block groups, use _safe just in case */ list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs, dirty_list) { if (cache->disk_cache_state == BTRFS_DC_CLEAR) cache_save_setup(cache, trans, path); } btrfs_free_path(path); return 0; } /* * transaction commit does final block group cache writeback during a * critical section where nothing is allowed to change the FS. This is * required in order for the cache to actually match the block group, * but can introduce a lot of latency into the commit. * * So, btrfs_start_dirty_block_groups is here to kick off block group * cache IO. There's a chance we'll have to redo some of it if the * block group changes again during the commit, but it greatly reduces * the commit latency by getting rid of the easy block groups while * we're still allowing others to join the commit. */ int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *cache; struct btrfs_transaction *cur_trans = trans->transaction; int ret = 0; int should_put; struct btrfs_path *path = NULL; LIST_HEAD(dirty); struct list_head *io = &cur_trans->io_bgs; int num_started = 0; int loops = 0; spin_lock(&cur_trans->dirty_bgs_lock); if (list_empty(&cur_trans->dirty_bgs)) { spin_unlock(&cur_trans->dirty_bgs_lock); return 0; } list_splice_init(&cur_trans->dirty_bgs, &dirty); spin_unlock(&cur_trans->dirty_bgs_lock); again: /* * make sure all the block groups on our dirty list actually * exist */ btrfs_create_pending_block_groups(trans); if (!path) { path = btrfs_alloc_path(); if (!path) return -ENOMEM; } /* * cache_write_mutex is here only to save us from balance or automatic * removal of empty block groups deleting this block group while we are * writing out the cache */ mutex_lock(&trans->transaction->cache_write_mutex); while (!list_empty(&dirty)) { bool drop_reserve = true; cache = list_first_entry(&dirty, struct btrfs_block_group_cache, dirty_list); /* * this can happen if something re-dirties a block * group that is already under IO. Just wait for it to * finish and then do it all again */ if (!list_empty(&cache->io_list)) { list_del_init(&cache->io_list); btrfs_wait_cache_io(trans, cache, path); btrfs_put_block_group(cache); } /* * btrfs_wait_cache_io uses the cache->dirty_list to decide * if it should update the cache_state. Don't delete * until after we wait. * * Since we're not running in the commit critical section * we need the dirty_bgs_lock to protect from update_block_group */ spin_lock(&cur_trans->dirty_bgs_lock); list_del_init(&cache->dirty_list); spin_unlock(&cur_trans->dirty_bgs_lock); should_put = 1; cache_save_setup(cache, trans, path); if (cache->disk_cache_state == BTRFS_DC_SETUP) { cache->io_ctl.inode = NULL; ret = btrfs_write_out_cache(trans, cache, path); if (ret == 0 && cache->io_ctl.inode) { num_started++; should_put = 0; /* * The cache_write_mutex is protecting the * io_list, also refer to the definition of * btrfs_transaction::io_bgs for more details */ list_add_tail(&cache->io_list, io); } else { /* * if we failed to write the cache, the * generation will be bad and life goes on */ ret = 0; } } if (!ret) { ret = write_one_cache_group(trans, path, cache); /* * Our block group might still be attached to the list * of new block groups in the transaction handle of some * other task (struct btrfs_trans_handle->new_bgs). This * means its block group item isn't yet in the extent * tree. If this happens ignore the error, as we will * try again later in the critical section of the * transaction commit. */ if (ret == -ENOENT) { ret = 0; spin_lock(&cur_trans->dirty_bgs_lock); if (list_empty(&cache->dirty_list)) { list_add_tail(&cache->dirty_list, &cur_trans->dirty_bgs); btrfs_get_block_group(cache); drop_reserve = false; } spin_unlock(&cur_trans->dirty_bgs_lock); } else if (ret) { btrfs_abort_transaction(trans, ret); } } /* if it's not on the io list, we need to put the block group */ if (should_put) btrfs_put_block_group(cache); if (drop_reserve) btrfs_delayed_refs_rsv_release(fs_info, 1); if (ret) break; /* * Avoid blocking other tasks for too long. It might even save * us from writing caches for block groups that are going to be * removed. */ mutex_unlock(&trans->transaction->cache_write_mutex); mutex_lock(&trans->transaction->cache_write_mutex); } mutex_unlock(&trans->transaction->cache_write_mutex); /* * go through delayed refs for all the stuff we've just kicked off * and then loop back (just once) */ ret = btrfs_run_delayed_refs(trans, 0); if (!ret && loops == 0) { loops++; spin_lock(&cur_trans->dirty_bgs_lock); list_splice_init(&cur_trans->dirty_bgs, &dirty); /* * dirty_bgs_lock protects us from concurrent block group * deletes too (not just cache_write_mutex). */ if (!list_empty(&dirty)) { spin_unlock(&cur_trans->dirty_bgs_lock); goto again; } spin_unlock(&cur_trans->dirty_bgs_lock); } else if (ret < 0) { btrfs_cleanup_dirty_bgs(cur_trans, fs_info); } btrfs_free_path(path); return ret; } int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *cache; struct btrfs_transaction *cur_trans = trans->transaction; int ret = 0; int should_put; struct btrfs_path *path; struct list_head *io = &cur_trans->io_bgs; int num_started = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; /* * Even though we are in the critical section of the transaction commit, * we can still have concurrent tasks adding elements to this * transaction's list of dirty block groups. These tasks correspond to * endio free space workers started when writeback finishes for a * space cache, which run inode.c:btrfs_finish_ordered_io(), and can * allocate new block groups as a result of COWing nodes of the root * tree when updating the free space inode. The writeback for the space * caches is triggered by an earlier call to * btrfs_start_dirty_block_groups() and iterations of the following * loop. * Also we want to do the cache_save_setup first and then run the * delayed refs to make sure we have the best chance at doing this all * in one shot. */ spin_lock(&cur_trans->dirty_bgs_lock); while (!list_empty(&cur_trans->dirty_bgs)) { cache = list_first_entry(&cur_trans->dirty_bgs, struct btrfs_block_group_cache, dirty_list); /* * this can happen if cache_save_setup re-dirties a block * group that is already under IO. Just wait for it to * finish and then do it all again */ if (!list_empty(&cache->io_list)) { spin_unlock(&cur_trans->dirty_bgs_lock); list_del_init(&cache->io_list); btrfs_wait_cache_io(trans, cache, path); btrfs_put_block_group(cache); spin_lock(&cur_trans->dirty_bgs_lock); } /* * don't remove from the dirty list until after we've waited * on any pending IO */ list_del_init(&cache->dirty_list); spin_unlock(&cur_trans->dirty_bgs_lock); should_put = 1; cache_save_setup(cache, trans, path); if (!ret) ret = btrfs_run_delayed_refs(trans, (unsigned long) -1); if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) { cache->io_ctl.inode = NULL; ret = btrfs_write_out_cache(trans, cache, path); if (ret == 0 && cache->io_ctl.inode) { num_started++; should_put = 0; list_add_tail(&cache->io_list, io); } else { /* * if we failed to write the cache, the * generation will be bad and life goes on */ ret = 0; } } if (!ret) { ret = write_one_cache_group(trans, path, cache); /* * One of the free space endio workers might have * created a new block group while updating a free space * cache's inode (at inode.c:btrfs_finish_ordered_io()) * and hasn't released its transaction handle yet, in * which case the new block group is still attached to * its transaction handle and its creation has not * finished yet (no block group item in the extent tree * yet, etc). If this is the case, wait for all free * space endio workers to finish and retry. This is a * a very rare case so no need for a more efficient and * complex approach. */ if (ret == -ENOENT) { wait_event(cur_trans->writer_wait, atomic_read(&cur_trans->num_writers) == 1); ret = write_one_cache_group(trans, path, cache); } if (ret) btrfs_abort_transaction(trans, ret); } /* if its not on the io list, we need to put the block group */ if (should_put) btrfs_put_block_group(cache); btrfs_delayed_refs_rsv_release(fs_info, 1); spin_lock(&cur_trans->dirty_bgs_lock); } spin_unlock(&cur_trans->dirty_bgs_lock); /* * Refer to the definition of io_bgs member for details why it's safe * to use it without any locking */ while (!list_empty(io)) { cache = list_first_entry(io, struct btrfs_block_group_cache, io_list); list_del_init(&cache->io_list); btrfs_wait_cache_io(trans, cache, path); btrfs_put_block_group(cache); } btrfs_free_path(path); return ret; } int btrfs_extent_readonly(struct btrfs_fs_info *fs_info, u64 bytenr) { struct btrfs_block_group_cache *block_group; int readonly = 0; block_group = btrfs_lookup_block_group(fs_info, bytenr); if (!block_group || block_group->ro) readonly = 1; if (block_group) btrfs_put_block_group(block_group); return readonly; } static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) { u64 extra_flags = chunk_to_extended(flags) & BTRFS_EXTENDED_PROFILE_MASK; write_seqlock(&fs_info->profiles_lock); if (flags & BTRFS_BLOCK_GROUP_DATA) fs_info->avail_data_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_METADATA) fs_info->avail_metadata_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_SYSTEM) fs_info->avail_system_alloc_bits |= extra_flags; write_sequnlock(&fs_info->profiles_lock); } /* * returns target flags in extended format or 0 if restripe for this * chunk_type is not in progress * * should be called with balance_lock held */ static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags) { struct btrfs_balance_control *bctl = fs_info->balance_ctl; u64 target = 0; if (!bctl) return 0; if (flags & BTRFS_BLOCK_GROUP_DATA && bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) { target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target; } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM && bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) { target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target; } else if (flags & BTRFS_BLOCK_GROUP_METADATA && bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) { target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target; } return target; } /* * @flags: available profiles in extended format (see ctree.h) * * Returns reduced profile in chunk format. If profile changing is in * progress (either running or paused) picks the target profile (if it's * already available), otherwise falls back to plain reducing. */ static u64 btrfs_reduce_alloc_profile(struct btrfs_fs_info *fs_info, u64 flags) { u64 num_devices = fs_info->fs_devices->rw_devices; u64 target; u64 raid_type; u64 allowed = 0; /* * see if restripe for this chunk_type is in progress, if so * try to reduce to the target profile */ spin_lock(&fs_info->balance_lock); target = get_restripe_target(fs_info, flags); if (target) { /* pick target profile only if it's already available */ if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) { spin_unlock(&fs_info->balance_lock); return extended_to_chunk(target); } } spin_unlock(&fs_info->balance_lock); /* First, mask out the RAID levels which aren't possible */ for (raid_type = 0; raid_type < BTRFS_NR_RAID_TYPES; raid_type++) { if (num_devices >= btrfs_raid_array[raid_type].devs_min) allowed |= btrfs_raid_array[raid_type].bg_flag; } allowed &= flags; if (allowed & BTRFS_BLOCK_GROUP_RAID6) allowed = BTRFS_BLOCK_GROUP_RAID6; else if (allowed & BTRFS_BLOCK_GROUP_RAID5) allowed = BTRFS_BLOCK_GROUP_RAID5; else if (allowed & BTRFS_BLOCK_GROUP_RAID10) allowed = BTRFS_BLOCK_GROUP_RAID10; else if (allowed & BTRFS_BLOCK_GROUP_RAID1) allowed = BTRFS_BLOCK_GROUP_RAID1; else if (allowed & BTRFS_BLOCK_GROUP_RAID0) allowed = BTRFS_BLOCK_GROUP_RAID0; flags &= ~BTRFS_BLOCK_GROUP_PROFILE_MASK; return extended_to_chunk(flags | allowed); } static u64 get_alloc_profile(struct btrfs_fs_info *fs_info, u64 orig_flags) { unsigned seq; u64 flags; do { flags = orig_flags; seq = read_seqbegin(&fs_info->profiles_lock); if (flags & BTRFS_BLOCK_GROUP_DATA) flags |= fs_info->avail_data_alloc_bits; else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) flags |= fs_info->avail_system_alloc_bits; else if (flags & BTRFS_BLOCK_GROUP_METADATA) flags |= fs_info->avail_metadata_alloc_bits; } while (read_seqretry(&fs_info->profiles_lock, seq)); return btrfs_reduce_alloc_profile(fs_info, flags); } static u64 get_alloc_profile_by_root(struct btrfs_root *root, int data) { struct btrfs_fs_info *fs_info = root->fs_info; u64 flags; u64 ret; if (data) flags = BTRFS_BLOCK_GROUP_DATA; else if (root == fs_info->chunk_root) flags = BTRFS_BLOCK_GROUP_SYSTEM; else flags = BTRFS_BLOCK_GROUP_METADATA; ret = get_alloc_profile(fs_info, flags); return ret; } u64 btrfs_data_alloc_profile(struct btrfs_fs_info *fs_info) { return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_DATA); } u64 btrfs_metadata_alloc_profile(struct btrfs_fs_info *fs_info) { return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_METADATA); } u64 btrfs_system_alloc_profile(struct btrfs_fs_info *fs_info) { return get_alloc_profile(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); } static void force_metadata_allocation(struct btrfs_fs_info *info) { struct list_head *head = &info->space_info; struct btrfs_space_info *found; rcu_read_lock(); list_for_each_entry_rcu(found, head, list) { if (found->flags & BTRFS_BLOCK_GROUP_METADATA) found->force_alloc = CHUNK_ALLOC_FORCE; } rcu_read_unlock(); } static int should_alloc_chunk(struct btrfs_fs_info *fs_info, struct btrfs_space_info *sinfo, int force) { u64 bytes_used = btrfs_space_info_used(sinfo, false); u64 thresh; if (force == CHUNK_ALLOC_FORCE) return 1; /* * in limited mode, we want to have some free space up to * about 1% of the FS size. */ if (force == CHUNK_ALLOC_LIMITED) { thresh = btrfs_super_total_bytes(fs_info->super_copy); thresh = max_t(u64, SZ_64M, div_factor_fine(thresh, 1)); if (sinfo->total_bytes - bytes_used < thresh) return 1; } if (bytes_used + SZ_2M < div_factor(sinfo->total_bytes, 8)) return 0; return 1; } static u64 get_profile_num_devs(struct btrfs_fs_info *fs_info, u64 type) { u64 num_dev; num_dev = btrfs_raid_array[btrfs_bg_flags_to_raid_index(type)].devs_max; if (!num_dev) num_dev = fs_info->fs_devices->rw_devices; return num_dev; } /* * If @is_allocation is true, reserve space in the system space info necessary * for allocating a chunk, otherwise if it's false, reserve space necessary for * removing a chunk. */ void check_system_chunk(struct btrfs_trans_handle *trans, u64 type) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_space_info *info; u64 left; u64 thresh; int ret = 0; u64 num_devs; /* * Needed because we can end up allocating a system chunk and for an * atomic and race free space reservation in the chunk block reserve. */ lockdep_assert_held(&fs_info->chunk_mutex); info = btrfs_find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); spin_lock(&info->lock); left = info->total_bytes - btrfs_space_info_used(info, true); spin_unlock(&info->lock); num_devs = get_profile_num_devs(fs_info, type); /* num_devs device items to update and 1 chunk item to add or remove */ thresh = btrfs_calc_trunc_metadata_size(fs_info, num_devs) + btrfs_calc_trans_metadata_size(fs_info, 1); if (left < thresh && btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { btrfs_info(fs_info, "left=%llu, need=%llu, flags=%llu", left, thresh, type); btrfs_dump_space_info(fs_info, info, 0, 0); } if (left < thresh) { u64 flags = btrfs_system_alloc_profile(fs_info); /* * Ignore failure to create system chunk. We might end up not * needing it, as we might not need to COW all nodes/leafs from * the paths we visit in the chunk tree (they were already COWed * or created in the current transaction for example). */ ret = btrfs_alloc_chunk(trans, flags); } if (!ret) { ret = btrfs_block_rsv_add(fs_info->chunk_root, &fs_info->chunk_block_rsv, thresh, BTRFS_RESERVE_NO_FLUSH); if (!ret) trans->chunk_bytes_reserved += thresh; } } /* * If force is CHUNK_ALLOC_FORCE: * - return 1 if it successfully allocates a chunk, * - return errors including -ENOSPC otherwise. * If force is NOT CHUNK_ALLOC_FORCE: * - return 0 if it doesn't need to allocate a new chunk, * - return 1 if it successfully allocates a chunk, * - return errors including -ENOSPC otherwise. */ int btrfs_chunk_alloc(struct btrfs_trans_handle *trans, u64 flags, enum btrfs_chunk_alloc_enum force) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_space_info *space_info; bool wait_for_alloc = false; bool should_alloc = false; int ret = 0; /* Don't re-enter if we're already allocating a chunk */ if (trans->allocating_chunk) return -ENOSPC; space_info = btrfs_find_space_info(fs_info, flags); ASSERT(space_info); do { spin_lock(&space_info->lock); if (force < space_info->force_alloc) force = space_info->force_alloc; should_alloc = should_alloc_chunk(fs_info, space_info, force); if (space_info->full) { /* No more free physical space */ if (should_alloc) ret = -ENOSPC; else ret = 0; spin_unlock(&space_info->lock); return ret; } else if (!should_alloc) { spin_unlock(&space_info->lock); return 0; } else if (space_info->chunk_alloc) { /* * Someone is already allocating, so we need to block * until this someone is finished and then loop to * recheck if we should continue with our allocation * attempt. */ wait_for_alloc = true; spin_unlock(&space_info->lock); mutex_lock(&fs_info->chunk_mutex); mutex_unlock(&fs_info->chunk_mutex); } else { /* Proceed with allocation */ space_info->chunk_alloc = 1; wait_for_alloc = false; spin_unlock(&space_info->lock); } cond_resched(); } while (wait_for_alloc); mutex_lock(&fs_info->chunk_mutex); trans->allocating_chunk = true; /* * If we have mixed data/metadata chunks we want to make sure we keep * allocating mixed chunks instead of individual chunks. */ if (btrfs_mixed_space_info(space_info)) flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA); /* * if we're doing a data chunk, go ahead and make sure that * we keep a reasonable number of metadata chunks allocated in the * FS as well. */ if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) { fs_info->data_chunk_allocations++; if (!(fs_info->data_chunk_allocations % fs_info->metadata_ratio)) force_metadata_allocation(fs_info); } /* * Check if we have enough space in SYSTEM chunk because we may need * to update devices. */ check_system_chunk(trans, flags); ret = btrfs_alloc_chunk(trans, flags); trans->allocating_chunk = false; spin_lock(&space_info->lock); if (ret < 0) { if (ret == -ENOSPC) space_info->full = 1; else goto out; } else { ret = 1; space_info->max_extent_size = 0; } space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; out: space_info->chunk_alloc = 0; spin_unlock(&space_info->lock); mutex_unlock(&fs_info->chunk_mutex); /* * When we allocate a new chunk we reserve space in the chunk block * reserve to make sure we can COW nodes/leafs in the chunk tree or * add new nodes/leafs to it if we end up needing to do it when * inserting the chunk item and updating device items as part of the * second phase of chunk allocation, performed by * btrfs_finish_chunk_alloc(). So make sure we don't accumulate a * large number of new block groups to create in our transaction * handle's new_bgs list to avoid exhausting the chunk block reserve * in extreme cases - like having a single transaction create many new * block groups when starting to write out the free space caches of all * the block groups that were made dirty during the lifetime of the * transaction. */ if (trans->chunk_bytes_reserved >= (u64)SZ_2M) btrfs_create_pending_block_groups(trans); return ret; } static int update_block_group(struct btrfs_trans_handle *trans, u64 bytenr, u64 num_bytes, int alloc) { struct btrfs_fs_info *info = trans->fs_info; struct btrfs_block_group_cache *cache = NULL; u64 total = num_bytes; u64 old_val; u64 byte_in_group; int factor; int ret = 0; /* block accounting for super block */ spin_lock(&info->delalloc_root_lock); old_val = btrfs_super_bytes_used(info->super_copy); if (alloc) old_val += num_bytes; else old_val -= num_bytes; btrfs_set_super_bytes_used(info->super_copy, old_val); spin_unlock(&info->delalloc_root_lock); while (total) { cache = btrfs_lookup_block_group(info, bytenr); if (!cache) { ret = -ENOENT; break; } factor = btrfs_bg_type_to_factor(cache->flags); /* * If this block group has free space cache written out, we * need to make sure to load it if we are removing space. This * is because we need the unpinning stage to actually add the * space back to the block group, otherwise we will leak space. */ if (!alloc && cache->cached == BTRFS_CACHE_NO) btrfs_cache_block_group(cache, 1); byte_in_group = bytenr - cache->key.objectid; WARN_ON(byte_in_group > cache->key.offset); spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); if (btrfs_test_opt(info, SPACE_CACHE) && cache->disk_cache_state < BTRFS_DC_CLEAR) cache->disk_cache_state = BTRFS_DC_CLEAR; old_val = btrfs_block_group_used(&cache->item); num_bytes = min(total, cache->key.offset - byte_in_group); if (alloc) { old_val += num_bytes; btrfs_set_block_group_used(&cache->item, old_val); cache->reserved -= num_bytes; cache->space_info->bytes_reserved -= num_bytes; cache->space_info->bytes_used += num_bytes; cache->space_info->disk_used += num_bytes * factor; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); } else { old_val -= num_bytes; btrfs_set_block_group_used(&cache->item, old_val); cache->pinned += num_bytes; btrfs_space_info_update_bytes_pinned(info, cache->space_info, num_bytes); cache->space_info->bytes_used -= num_bytes; cache->space_info->disk_used -= num_bytes * factor; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); trace_btrfs_space_reservation(info, "pinned", cache->space_info->flags, num_bytes, 1); percpu_counter_add_batch(&cache->space_info->total_bytes_pinned, num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH); set_extent_dirty(info->pinned_extents, bytenr, bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL); } spin_lock(&trans->transaction->dirty_bgs_lock); if (list_empty(&cache->dirty_list)) { list_add_tail(&cache->dirty_list, &trans->transaction->dirty_bgs); trans->delayed_ref_updates++; btrfs_get_block_group(cache); } spin_unlock(&trans->transaction->dirty_bgs_lock); /* * No longer have used bytes in this block group, queue it for * deletion. We do this after adding the block group to the * dirty list to avoid races between cleaner kthread and space * cache writeout. */ if (!alloc && old_val == 0) btrfs_mark_bg_unused(cache); btrfs_put_block_group(cache); total -= num_bytes; bytenr += num_bytes; } /* Modified block groups are accounted for in the delayed_refs_rsv. */ btrfs_update_delayed_refs_rsv(trans); return ret; } static u64 first_logical_byte(struct btrfs_fs_info *fs_info, u64 search_start) { struct btrfs_block_group_cache *cache; u64 bytenr; spin_lock(&fs_info->block_group_cache_lock); bytenr = fs_info->first_logical_byte; spin_unlock(&fs_info->block_group_cache_lock); if (bytenr < (u64)-1) return bytenr; cache = btrfs_lookup_first_block_group(fs_info, search_start); if (!cache) return 0; bytenr = cache->key.objectid; btrfs_put_block_group(cache); return bytenr; } static int pin_down_extent(struct btrfs_block_group_cache *cache, u64 bytenr, u64 num_bytes, int reserved) { struct btrfs_fs_info *fs_info = cache->fs_info; spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->pinned += num_bytes; btrfs_space_info_update_bytes_pinned(fs_info, cache->space_info, num_bytes); if (reserved) { cache->reserved -= num_bytes; cache->space_info->bytes_reserved -= num_bytes; } spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); trace_btrfs_space_reservation(fs_info, "pinned", cache->space_info->flags, num_bytes, 1); percpu_counter_add_batch(&cache->space_info->total_bytes_pinned, num_bytes, BTRFS_TOTAL_BYTES_PINNED_BATCH); set_extent_dirty(fs_info->pinned_extents, bytenr, bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL); return 0; } /* * this function must be called within transaction */ int btrfs_pin_extent(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes, int reserved) { struct btrfs_block_group_cache *cache; cache = btrfs_lookup_block_group(fs_info, bytenr); BUG_ON(!cache); /* Logic error */ pin_down_extent(cache, bytenr, num_bytes, reserved); btrfs_put_block_group(cache); return 0; } /* * this function must be called within transaction */ int btrfs_pin_extent_for_log_replay(struct btrfs_fs_info *fs_info, u64 bytenr, u64 num_bytes) { struct btrfs_block_group_cache *cache; int ret; cache = btrfs_lookup_block_group(fs_info, bytenr); if (!cache) return -EINVAL; /* * pull in the free space cache (if any) so that our pin * removes the free space from the cache. We have load_only set * to one because the slow code to read in the free extents does check * the pinned extents. */ btrfs_cache_block_group(cache, 1); pin_down_extent(cache, bytenr, num_bytes, 0); /* remove us from the free space cache (if we're there at all) */ ret = btrfs_remove_free_space(cache, bytenr, num_bytes); btrfs_put_block_group(cache); return ret; } static int __exclude_logged_extent(struct btrfs_fs_info *fs_info, u64 start, u64 num_bytes) { int ret; struct btrfs_block_group_cache *block_group; struct btrfs_caching_control *caching_ctl; block_group = btrfs_lookup_block_group(fs_info, start); if (!block_group) return -EINVAL; btrfs_cache_block_group(block_group, 0); caching_ctl = btrfs_get_caching_control(block_group); if (!caching_ctl) { /* Logic error */ BUG_ON(!btrfs_block_group_cache_done(block_group)); ret = btrfs_remove_free_space(block_group, start, num_bytes); } else { mutex_lock(&caching_ctl->mutex); if (start >= caching_ctl->progress) { ret = btrfs_add_excluded_extent(fs_info, start, num_bytes); } else if (start + num_bytes <= caching_ctl->progress) { ret = btrfs_remove_free_space(block_group, start, num_bytes); } else { num_bytes = caching_ctl->progress - start; ret = btrfs_remove_free_space(block_group, start, num_bytes); if (ret) goto out_lock; num_bytes = (start + num_bytes) - caching_ctl->progress; start = caching_ctl->progress; ret = btrfs_add_excluded_extent(fs_info, start, num_bytes); } out_lock: mutex_unlock(&caching_ctl->mutex); btrfs_put_caching_control(caching_ctl); } btrfs_put_block_group(block_group); return ret; } int btrfs_exclude_logged_extents(struct extent_buffer *eb) { struct btrfs_fs_info *fs_info = eb->fs_info; struct btrfs_file_extent_item *item; struct btrfs_key key; int found_type; int i; int ret = 0; if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) return 0; for (i = 0; i < btrfs_header_nritems(eb); i++) { btrfs_item_key_to_cpu(eb, &key, i); if (key.type != BTRFS_EXTENT_DATA_KEY) continue; item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); found_type = btrfs_file_extent_type(eb, item); if (found_type == BTRFS_FILE_EXTENT_INLINE) continue; if (btrfs_file_extent_disk_bytenr(eb, item) == 0) continue; key.objectid = btrfs_file_extent_disk_bytenr(eb, item); key.offset = btrfs_file_extent_disk_num_bytes(eb, item); ret = __exclude_logged_extent(fs_info, key.objectid, key.offset); if (ret) break; } return ret; } static void btrfs_inc_block_group_reservations(struct btrfs_block_group_cache *bg) { atomic_inc(&bg->reservations); } /** * btrfs_add_reserved_bytes - update the block_group and space info counters * @cache: The cache we are manipulating * @ram_bytes: The number of bytes of file content, and will be same to * @num_bytes except for the compress path. * @num_bytes: The number of bytes in question * @delalloc: The blocks are allocated for the delalloc write * * This is called by the allocator when it reserves space. If this is a * reservation and the block group has become read only we cannot make the * reservation and return -EAGAIN, otherwise this function always succeeds. */ static int btrfs_add_reserved_bytes(struct btrfs_block_group_cache *cache, u64 ram_bytes, u64 num_bytes, int delalloc) { struct btrfs_space_info *space_info = cache->space_info; int ret = 0; spin_lock(&space_info->lock); spin_lock(&cache->lock); if (cache->ro) { ret = -EAGAIN; } else { cache->reserved += num_bytes; space_info->bytes_reserved += num_bytes; btrfs_space_info_update_bytes_may_use(cache->fs_info, space_info, -ram_bytes); if (delalloc) cache->delalloc_bytes += num_bytes; } spin_unlock(&cache->lock); spin_unlock(&space_info->lock); return ret; } /** * btrfs_free_reserved_bytes - update the block_group and space info counters * @cache: The cache we are manipulating * @num_bytes: The number of bytes in question * @delalloc: The blocks are allocated for the delalloc write * * This is called by somebody who is freeing space that was never actually used * on disk. For example if you reserve some space for a new leaf in transaction * A and before transaction A commits you free that leaf, you call this with * reserve set to 0 in order to clear the reservation. */ static void btrfs_free_reserved_bytes(struct btrfs_block_group_cache *cache, u64 num_bytes, int delalloc) { struct btrfs_space_info *space_info = cache->space_info; spin_lock(&space_info->lock); spin_lock(&cache->lock); if (cache->ro) space_info->bytes_readonly += num_bytes; cache->reserved -= num_bytes; space_info->bytes_reserved -= num_bytes; space_info->max_extent_size = 0; if (delalloc) cache->delalloc_bytes -= num_bytes; spin_unlock(&cache->lock); spin_unlock(&space_info->lock); } void btrfs_prepare_extent_commit(struct btrfs_fs_info *fs_info) { struct btrfs_caching_control *next; struct btrfs_caching_control *caching_ctl; struct btrfs_block_group_cache *cache; down_write(&fs_info->commit_root_sem); list_for_each_entry_safe(caching_ctl, next, &fs_info->caching_block_groups, list) { cache = caching_ctl->block_group; if (btrfs_block_group_cache_done(cache)) { cache->last_byte_to_unpin = (u64)-1; list_del_init(&caching_ctl->list); btrfs_put_caching_control(caching_ctl); } else { cache->last_byte_to_unpin = caching_ctl->progress; } } if (fs_info->pinned_extents == &fs_info->freed_extents[0]) fs_info->pinned_extents = &fs_info->freed_extents[1]; else fs_info->pinned_extents = &fs_info->freed_extents[0]; up_write(&fs_info->commit_root_sem); btrfs_update_global_block_rsv(fs_info); } /* * Returns the free cluster for the given space info and sets empty_cluster to * what it should be based on the mount options. */ static struct btrfs_free_cluster * fetch_cluster_info(struct btrfs_fs_info *fs_info, struct btrfs_space_info *space_info, u64 *empty_cluster) { struct btrfs_free_cluster *ret = NULL; *empty_cluster = 0; if (btrfs_mixed_space_info(space_info)) return ret; if (space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { ret = &fs_info->meta_alloc_cluster; if (btrfs_test_opt(fs_info, SSD)) *empty_cluster = SZ_2M; else *empty_cluster = SZ_64K; } else if ((space_info->flags & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(fs_info, SSD_SPREAD)) { *empty_cluster = SZ_2M; ret = &fs_info->data_alloc_cluster; } return ret; } static int unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end, const bool return_free_space) { struct btrfs_block_group_cache *cache = NULL; struct btrfs_space_info *space_info; struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; struct btrfs_free_cluster *cluster = NULL; u64 len; u64 total_unpinned = 0; u64 empty_cluster = 0; bool readonly; while (start <= end) { readonly = false; if (!cache || start >= cache->key.objectid + cache->key.offset) { if (cache) btrfs_put_block_group(cache); total_unpinned = 0; cache = btrfs_lookup_block_group(fs_info, start); BUG_ON(!cache); /* Logic error */ cluster = fetch_cluster_info(fs_info, cache->space_info, &empty_cluster); empty_cluster <<= 1; } len = cache->key.objectid + cache->key.offset - start; len = min(len, end + 1 - start); if (start < cache->last_byte_to_unpin) { len = min(len, cache->last_byte_to_unpin - start); if (return_free_space) btrfs_add_free_space(cache, start, len); } start += len; total_unpinned += len; space_info = cache->space_info; /* * If this space cluster has been marked as fragmented and we've * unpinned enough in this block group to potentially allow a * cluster to be created inside of it go ahead and clear the * fragmented check. */ if (cluster && cluster->fragmented && total_unpinned > empty_cluster) { spin_lock(&cluster->lock); cluster->fragmented = 0; spin_unlock(&cluster->lock); } spin_lock(&space_info->lock); spin_lock(&cache->lock); cache->pinned -= len; btrfs_space_info_update_bytes_pinned(fs_info, space_info, -len); trace_btrfs_space_reservation(fs_info, "pinned", space_info->flags, len, 0); space_info->max_extent_size = 0; percpu_counter_add_batch(&space_info->total_bytes_pinned, -len, BTRFS_TOTAL_BYTES_PINNED_BATCH); if (cache->ro) { space_info->bytes_readonly += len; readonly = true; } spin_unlock(&cache->lock); if (!readonly && return_free_space && global_rsv->space_info == space_info) { u64 to_add = len; spin_lock(&global_rsv->lock); if (!global_rsv->full) { to_add = min(len, global_rsv->size - global_rsv->reserved); global_rsv->reserved += to_add; btrfs_space_info_update_bytes_may_use(fs_info, space_info, to_add); if (global_rsv->reserved >= global_rsv->size) global_rsv->full = 1; trace_btrfs_space_reservation(fs_info, "space_info", space_info->flags, to_add, 1); len -= to_add; } spin_unlock(&global_rsv->lock); /* Add to any tickets we may have */ if (len) btrfs_space_info_add_new_bytes(fs_info, space_info, len); } spin_unlock(&space_info->lock); } if (cache) btrfs_put_block_group(cache); return 0; } int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *block_group, *tmp; struct list_head *deleted_bgs; struct extent_io_tree *unpin; u64 start; u64 end; int ret; if (fs_info->pinned_extents == &fs_info->freed_extents[0]) unpin = &fs_info->freed_extents[1]; else unpin = &fs_info->freed_extents[0]; while (!trans->aborted) { struct extent_state *cached_state = NULL; mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY, &cached_state); if (ret) { mutex_unlock(&fs_info->unused_bg_unpin_mutex); break; } if (btrfs_test_opt(fs_info, DISCARD)) ret = btrfs_discard_extent(fs_info, start, end + 1 - start, NULL); clear_extent_dirty(unpin, start, end, &cached_state); unpin_extent_range(fs_info, start, end, true); mutex_unlock(&fs_info->unused_bg_unpin_mutex); free_extent_state(cached_state); cond_resched(); } /* * Transaction is finished. We don't need the lock anymore. We * do need to clean up the block groups in case of a transaction * abort. */ deleted_bgs = &trans->transaction->deleted_bgs; list_for_each_entry_safe(block_group, tmp, deleted_bgs, bg_list) { u64 trimmed = 0; ret = -EROFS; if (!trans->aborted) ret = btrfs_discard_extent(fs_info, block_group->key.objectid, block_group->key.offset, &trimmed); list_del_init(&block_group->bg_list); btrfs_put_block_group_trimming(block_group); btrfs_put_block_group(block_group); if (ret) { const char *errstr = btrfs_decode_error(ret); btrfs_warn(fs_info, "discard failed while removing blockgroup: errno=%d %s", ret, errstr); } } return 0; } static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, u64 parent, u64 root_objectid, u64 owner_objectid, u64 owner_offset, int refs_to_drop, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_fs_info *info = trans->fs_info; struct btrfs_key key; struct btrfs_path *path; struct btrfs_root *extent_root = info->extent_root; struct extent_buffer *leaf; struct btrfs_extent_item *ei; struct btrfs_extent_inline_ref *iref; int ret; int is_data; int extent_slot = 0; int found_extent = 0; int num_to_del = 1; u32 item_size; u64 refs; u64 bytenr = node->bytenr; u64 num_bytes = node->num_bytes; int last_ref = 0; bool skinny_metadata = btrfs_fs_incompat(info, SKINNY_METADATA); path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; path->leave_spinning = 1; is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID; BUG_ON(!is_data && refs_to_drop != 1); if (is_data) skinny_metadata = false; ret = lookup_extent_backref(trans, path, &iref, bytenr, num_bytes, parent, root_objectid, owner_objectid, owner_offset); if (ret == 0) { extent_slot = path->slots[0]; while (extent_slot >= 0) { btrfs_item_key_to_cpu(path->nodes[0], &key, extent_slot); if (key.objectid != bytenr) break; if (key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == num_bytes) { found_extent = 1; break; } if (key.type == BTRFS_METADATA_ITEM_KEY && key.offset == owner_objectid) { found_extent = 1; break; } if (path->slots[0] - extent_slot > 5) break; extent_slot--; } if (!found_extent) { BUG_ON(iref); ret = remove_extent_backref(trans, path, NULL, refs_to_drop, is_data, &last_ref); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } btrfs_release_path(path); path->leave_spinning = 1; key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; if (!is_data && skinny_metadata) { key.type = BTRFS_METADATA_ITEM_KEY; key.offset = owner_objectid; } ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); if (ret > 0 && skinny_metadata && path->slots[0]) { /* * Couldn't find our skinny metadata item, * see if we have ye olde extent item. */ path->slots[0]--; btrfs_item_key_to_cpu(path->nodes[0], &key, path->slots[0]); if (key.objectid == bytenr && key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == num_bytes) ret = 0; } if (ret > 0 && skinny_metadata) { skinny_metadata = false; key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; btrfs_release_path(path); ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); } if (ret) { btrfs_err(info, "umm, got %d back from search, was looking for %llu", ret, bytenr); if (ret > 0) btrfs_print_leaf(path->nodes[0]); } if (ret < 0) { btrfs_abort_transaction(trans, ret); goto out; } extent_slot = path->slots[0]; } } else if (WARN_ON(ret == -ENOENT)) { btrfs_print_leaf(path->nodes[0]); btrfs_err(info, "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu", bytenr, parent, root_objectid, owner_objectid, owner_offset); btrfs_abort_transaction(trans, ret); goto out; } else { btrfs_abort_transaction(trans, ret); goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, extent_slot); if (unlikely(item_size < sizeof(*ei))) { ret = -EINVAL; btrfs_print_v0_err(info); btrfs_abort_transaction(trans, ret); goto out; } ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item); if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID && key.type == BTRFS_EXTENT_ITEM_KEY) { struct btrfs_tree_block_info *bi; BUG_ON(item_size < sizeof(*ei) + sizeof(*bi)); bi = (struct btrfs_tree_block_info *)(ei + 1); WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi)); } refs = btrfs_extent_refs(leaf, ei); if (refs < refs_to_drop) { btrfs_err(info, "trying to drop %d refs but we only have %Lu for bytenr %Lu", refs_to_drop, refs, bytenr); ret = -EINVAL; btrfs_abort_transaction(trans, ret); goto out; } refs -= refs_to_drop; if (refs > 0) { if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); /* * In the case of inline back ref, reference count will * be updated by remove_extent_backref */ if (iref) { BUG_ON(!found_extent); } else { btrfs_set_extent_refs(leaf, ei, refs); btrfs_mark_buffer_dirty(leaf); } if (found_extent) { ret = remove_extent_backref(trans, path, iref, refs_to_drop, is_data, &last_ref); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } } } else { if (found_extent) { BUG_ON(is_data && refs_to_drop != extent_data_ref_count(path, iref)); if (iref) { BUG_ON(path->slots[0] != extent_slot); } else { BUG_ON(path->slots[0] != extent_slot + 1); path->slots[0] = extent_slot; num_to_del = 2; } } last_ref = 1; ret = btrfs_del_items(trans, extent_root, path, path->slots[0], num_to_del); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } btrfs_release_path(path); if (is_data) { ret = btrfs_del_csums(trans, info, bytenr, num_bytes); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } } ret = add_to_free_space_tree(trans, bytenr, num_bytes); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } ret = update_block_group(trans, bytenr, num_bytes, 0); if (ret) { btrfs_abort_transaction(trans, ret); goto out; } } btrfs_release_path(path); out: btrfs_free_path(path); return ret; } /* * when we free an block, it is possible (and likely) that we free the last * delayed ref for that extent as well. This searches the delayed ref tree for * a given extent, and if there are no other delayed refs to be processed, it * removes it from the tree. */ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, u64 bytenr) { struct btrfs_delayed_ref_head *head; struct btrfs_delayed_ref_root *delayed_refs; int ret = 0; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); head = btrfs_find_delayed_ref_head(delayed_refs, bytenr); if (!head) goto out_delayed_unlock; spin_lock(&head->lock); if (!RB_EMPTY_ROOT(&head->ref_tree.rb_root)) goto out; if (cleanup_extent_op(head) != NULL) goto out; /* * waiting for the lock here would deadlock. If someone else has it * locked they are already in the process of dropping it anyway */ if (!mutex_trylock(&head->mutex)) goto out; btrfs_delete_ref_head(delayed_refs, head); head->processing = 0; spin_unlock(&head->lock); spin_unlock(&delayed_refs->lock); BUG_ON(head->extent_op); if (head->must_insert_reserved) ret = 1; btrfs_cleanup_ref_head_accounting(trans->fs_info, delayed_refs, head); mutex_unlock(&head->mutex); btrfs_put_delayed_ref_head(head); return ret; out: spin_unlock(&head->lock); out_delayed_unlock: spin_unlock(&delayed_refs->lock); return 0; } void btrfs_free_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, u64 parent, int last_ref) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_ref generic_ref = { 0 }; int pin = 1; int ret; btrfs_init_generic_ref(&generic_ref, BTRFS_DROP_DELAYED_REF, buf->start, buf->len, parent); btrfs_init_tree_ref(&generic_ref, btrfs_header_level(buf), root->root_key.objectid); if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { int old_ref_mod, new_ref_mod; btrfs_ref_tree_mod(fs_info, &generic_ref); ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, NULL, &old_ref_mod, &new_ref_mod); BUG_ON(ret); /* -ENOMEM */ pin = old_ref_mod >= 0 && new_ref_mod < 0; } if (last_ref && btrfs_header_generation(buf) == trans->transid) { struct btrfs_block_group_cache *cache; if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { ret = check_ref_cleanup(trans, buf->start); if (!ret) goto out; } pin = 0; cache = btrfs_lookup_block_group(fs_info, buf->start); if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { pin_down_extent(cache, buf->start, buf->len, 1); btrfs_put_block_group(cache); goto out; } WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)); btrfs_add_free_space(cache, buf->start, buf->len); btrfs_free_reserved_bytes(cache, buf->len, 0); btrfs_put_block_group(cache); trace_btrfs_reserved_extent_free(fs_info, buf->start, buf->len); } out: if (pin) add_pinned_bytes(fs_info, &generic_ref); if (last_ref) { /* * Deleting the buffer, clear the corrupt flag since it doesn't * matter anymore. */ clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); } } /* Can return -ENOMEM */ int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_ref *ref) { struct btrfs_fs_info *fs_info = trans->fs_info; int old_ref_mod, new_ref_mod; int ret; if (btrfs_is_testing(fs_info)) return 0; /* * tree log blocks never actually go into the extent allocation * tree, just update pinning info and exit early. */ if ((ref->type == BTRFS_REF_METADATA && ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) || (ref->type == BTRFS_REF_DATA && ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID)) { /* unlocks the pinned mutex */ btrfs_pin_extent(fs_info, ref->bytenr, ref->len, 1); old_ref_mod = new_ref_mod = 0; ret = 0; } else if (ref->type == BTRFS_REF_METADATA) { ret = btrfs_add_delayed_tree_ref(trans, ref, NULL, &old_ref_mod, &new_ref_mod); } else { ret = btrfs_add_delayed_data_ref(trans, ref, 0, &old_ref_mod, &new_ref_mod); } if (!((ref->type == BTRFS_REF_METADATA && ref->tree_ref.root == BTRFS_TREE_LOG_OBJECTID) || (ref->type == BTRFS_REF_DATA && ref->data_ref.ref_root == BTRFS_TREE_LOG_OBJECTID))) btrfs_ref_tree_mod(fs_info, ref); if (ret == 0 && old_ref_mod >= 0 && new_ref_mod < 0) add_pinned_bytes(fs_info, ref); return ret; } /* * when we wait for progress in the block group caching, its because * our allocation attempt failed at least once. So, we must sleep * and let some progress happen before we try again. * * This function will sleep at least once waiting for new free space to * show up, and then it will check the block group free space numbers * for our min num_bytes. Another option is to have it go ahead * and look in the rbtree for a free extent of a given size, but this * is a good start. * * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using * any of the information in this block group. */ void btrfs_wait_block_group_cache_progress(struct btrfs_block_group_cache *cache, u64 num_bytes) { struct btrfs_caching_control *caching_ctl; caching_ctl = btrfs_get_caching_control(cache); if (!caching_ctl) return; wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache) || (cache->free_space_ctl->free_space >= num_bytes)); btrfs_put_caching_control(caching_ctl); } int btrfs_wait_block_group_cache_done(struct btrfs_block_group_cache *cache) { struct btrfs_caching_control *caching_ctl; int ret = 0; caching_ctl = btrfs_get_caching_control(cache); if (!caching_ctl) return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0; wait_event(caching_ctl->wait, btrfs_block_group_cache_done(cache)); if (cache->cached == BTRFS_CACHE_ERROR) ret = -EIO; btrfs_put_caching_control(caching_ctl); return ret; } enum btrfs_loop_type { LOOP_CACHING_NOWAIT, LOOP_CACHING_WAIT, LOOP_ALLOC_CHUNK, LOOP_NO_EMPTY_SIZE, }; static inline void btrfs_lock_block_group(struct btrfs_block_group_cache *cache, int delalloc) { if (delalloc) down_read(&cache->data_rwsem); } static inline void btrfs_grab_block_group(struct btrfs_block_group_cache *cache, int delalloc) { btrfs_get_block_group(cache); if (delalloc) down_read(&cache->data_rwsem); } static struct btrfs_block_group_cache * btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, struct btrfs_free_cluster *cluster, int delalloc) { struct btrfs_block_group_cache *used_bg = NULL; spin_lock(&cluster->refill_lock); while (1) { used_bg = cluster->block_group; if (!used_bg) return NULL; if (used_bg == block_group) return used_bg; btrfs_get_block_group(used_bg); if (!delalloc) return used_bg; if (down_read_trylock(&used_bg->data_rwsem)) return used_bg; spin_unlock(&cluster->refill_lock); /* We should only have one-level nested. */ down_read_nested(&used_bg->data_rwsem, SINGLE_DEPTH_NESTING); spin_lock(&cluster->refill_lock); if (used_bg == cluster->block_group) return used_bg; up_read(&used_bg->data_rwsem); btrfs_put_block_group(used_bg); } } static inline void btrfs_release_block_group(struct btrfs_block_group_cache *cache, int delalloc) { if (delalloc) up_read(&cache->data_rwsem); btrfs_put_block_group(cache); } /* * Structure used internally for find_free_extent() function. Wraps needed * parameters. */ struct find_free_extent_ctl { /* Basic allocation info */ u64 ram_bytes; u64 num_bytes; u64 empty_size; u64 flags; int delalloc; /* Where to start the search inside the bg */ u64 search_start; /* For clustered allocation */ u64 empty_cluster; bool have_caching_bg; bool orig_have_caching_bg; /* RAID index, converted from flags */ int index; /* * Current loop number, check find_free_extent_update_loop() for details */ int loop; /* * Whether we're refilling a cluster, if true we need to re-search * current block group but don't try to refill the cluster again. */ bool retry_clustered; /* * Whether we're updating free space cache, if true we need to re-search * current block group but don't try updating free space cache again. */ bool retry_unclustered; /* If current block group is cached */ int cached; /* Max contiguous hole found */ u64 max_extent_size; /* Total free space from free space cache, not always contiguous */ u64 total_free_space; /* Found result */ u64 found_offset; }; /* * Helper function for find_free_extent(). * * Return -ENOENT to inform caller that we need fallback to unclustered mode. * Return -EAGAIN to inform caller that we need to re-search this block group * Return >0 to inform caller that we find nothing * Return 0 means we have found a location and set ffe_ctl->found_offset. */ static int find_free_extent_clustered(struct btrfs_block_group_cache *bg, struct btrfs_free_cluster *last_ptr, struct find_free_extent_ctl *ffe_ctl, struct btrfs_block_group_cache **cluster_bg_ret) { struct btrfs_block_group_cache *cluster_bg; u64 aligned_cluster; u64 offset; int ret; cluster_bg = btrfs_lock_cluster(bg, last_ptr, ffe_ctl->delalloc); if (!cluster_bg) goto refill_cluster; if (cluster_bg != bg && (cluster_bg->ro || !block_group_bits(cluster_bg, ffe_ctl->flags))) goto release_cluster; offset = btrfs_alloc_from_cluster(cluster_bg, last_ptr, ffe_ctl->num_bytes, cluster_bg->key.objectid, &ffe_ctl->max_extent_size); if (offset) { /* We have a block, we're done */ spin_unlock(&last_ptr->refill_lock); trace_btrfs_reserve_extent_cluster(cluster_bg, ffe_ctl->search_start, ffe_ctl->num_bytes); *cluster_bg_ret = cluster_bg; ffe_ctl->found_offset = offset; return 0; } WARN_ON(last_ptr->block_group != cluster_bg); release_cluster: /* * If we are on LOOP_NO_EMPTY_SIZE, we can't set up a new clusters, so * lets just skip it and let the allocator find whatever block it can * find. If we reach this point, we will have tried the cluster * allocator plenty of times and not have found anything, so we are * likely way too fragmented for the clustering stuff to find anything. * * However, if the cluster is taken from the current block group, * release the cluster first, so that we stand a better chance of * succeeding in the unclustered allocation. */ if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE && cluster_bg != bg) { spin_unlock(&last_ptr->refill_lock); btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc); return -ENOENT; } /* This cluster didn't work out, free it and start over */ btrfs_return_cluster_to_free_space(NULL, last_ptr); if (cluster_bg != bg) btrfs_release_block_group(cluster_bg, ffe_ctl->delalloc); refill_cluster: if (ffe_ctl->loop >= LOOP_NO_EMPTY_SIZE) { spin_unlock(&last_ptr->refill_lock); return -ENOENT; } aligned_cluster = max_t(u64, ffe_ctl->empty_cluster + ffe_ctl->empty_size, bg->full_stripe_len); ret = btrfs_find_space_cluster(bg, last_ptr, ffe_ctl->search_start, ffe_ctl->num_bytes, aligned_cluster); if (ret == 0) { /* Now pull our allocation out of this cluster */ offset = btrfs_alloc_from_cluster(bg, last_ptr, ffe_ctl->num_bytes, ffe_ctl->search_start, &ffe_ctl->max_extent_size); if (offset) { /* We found one, proceed */ spin_unlock(&last_ptr->refill_lock); trace_btrfs_reserve_extent_cluster(bg, ffe_ctl->search_start, ffe_ctl->num_bytes); ffe_ctl->found_offset = offset; return 0; } } else if (!ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT && !ffe_ctl->retry_clustered) { spin_unlock(&last_ptr->refill_lock); ffe_ctl->retry_clustered = true; btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes + ffe_ctl->empty_cluster + ffe_ctl->empty_size); return -EAGAIN; } /* * At this point we either didn't find a cluster or we weren't able to * allocate a block from our cluster. Free the cluster we've been * trying to use, and go to the next block group. */ btrfs_return_cluster_to_free_space(NULL, last_ptr); spin_unlock(&last_ptr->refill_lock); return 1; } /* * Return >0 to inform caller that we find nothing * Return 0 when we found an free extent and set ffe_ctrl->found_offset * Return -EAGAIN to inform caller that we need to re-search this block group */ static int find_free_extent_unclustered(struct btrfs_block_group_cache *bg, struct btrfs_free_cluster *last_ptr, struct find_free_extent_ctl *ffe_ctl) { u64 offset; /* * We are doing an unclustered allocation, set the fragmented flag so * we don't bother trying to setup a cluster again until we get more * space. */ if (unlikely(last_ptr)) { spin_lock(&last_ptr->lock); last_ptr->fragmented = 1; spin_unlock(&last_ptr->lock); } if (ffe_ctl->cached) { struct btrfs_free_space_ctl *free_space_ctl; free_space_ctl = bg->free_space_ctl; spin_lock(&free_space_ctl->tree_lock); if (free_space_ctl->free_space < ffe_ctl->num_bytes + ffe_ctl->empty_cluster + ffe_ctl->empty_size) { ffe_ctl->total_free_space = max_t(u64, ffe_ctl->total_free_space, free_space_ctl->free_space); spin_unlock(&free_space_ctl->tree_lock); return 1; } spin_unlock(&free_space_ctl->tree_lock); } offset = btrfs_find_space_for_alloc(bg, ffe_ctl->search_start, ffe_ctl->num_bytes, ffe_ctl->empty_size, &ffe_ctl->max_extent_size); /* * If we didn't find a chunk, and we haven't failed on this block group * before, and this block group is in the middle of caching and we are * ok with waiting, then go ahead and wait for progress to be made, and * set @retry_unclustered to true. * * If @retry_unclustered is true then we've already waited on this * block group once and should move on to the next block group. */ if (!offset && !ffe_ctl->retry_unclustered && !ffe_ctl->cached && ffe_ctl->loop > LOOP_CACHING_NOWAIT) { btrfs_wait_block_group_cache_progress(bg, ffe_ctl->num_bytes + ffe_ctl->empty_size); ffe_ctl->retry_unclustered = true; return -EAGAIN; } else if (!offset) { return 1; } ffe_ctl->found_offset = offset; return 0; } /* * Return >0 means caller needs to re-search for free extent * Return 0 means we have the needed free extent. * Return <0 means we failed to locate any free extent. */ static int find_free_extent_update_loop(struct btrfs_fs_info *fs_info, struct btrfs_free_cluster *last_ptr, struct btrfs_key *ins, struct find_free_extent_ctl *ffe_ctl, int full_search, bool use_cluster) { struct btrfs_root *root = fs_info->extent_root; int ret; if ((ffe_ctl->loop == LOOP_CACHING_NOWAIT) && ffe_ctl->have_caching_bg && !ffe_ctl->orig_have_caching_bg) ffe_ctl->orig_have_caching_bg = true; if (!ins->objectid && ffe_ctl->loop >= LOOP_CACHING_WAIT && ffe_ctl->have_caching_bg) return 1; if (!ins->objectid && ++(ffe_ctl->index) < BTRFS_NR_RAID_TYPES) return 1; if (ins->objectid) { if (!use_cluster && last_ptr) { spin_lock(&last_ptr->lock); last_ptr->window_start = ins->objectid; spin_unlock(&last_ptr->lock); } return 0; } /* * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking * caching kthreads as we move along * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching * LOOP_ALLOC_CHUNK, force a chunk allocation and try again * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try * again */ if (ffe_ctl->loop < LOOP_NO_EMPTY_SIZE) { ffe_ctl->index = 0; if (ffe_ctl->loop == LOOP_CACHING_NOWAIT) { /* * We want to skip the LOOP_CACHING_WAIT step if we * don't have any uncached bgs and we've already done a * full search through. */ if (ffe_ctl->orig_have_caching_bg || !full_search) ffe_ctl->loop = LOOP_CACHING_WAIT; else ffe_ctl->loop = LOOP_ALLOC_CHUNK; } else { ffe_ctl->loop++; } if (ffe_ctl->loop == LOOP_ALLOC_CHUNK) { struct btrfs_trans_handle *trans; int exist = 0; trans = current->journal_info; if (trans) exist = 1; else trans = btrfs_join_transaction(root); if (IS_ERR(trans)) { ret = PTR_ERR(trans); return ret; } ret = btrfs_chunk_alloc(trans, ffe_ctl->flags, CHUNK_ALLOC_FORCE); /* * If we can't allocate a new chunk we've already looped * through at least once, move on to the NO_EMPTY_SIZE * case. */ if (ret == -ENOSPC) ffe_ctl->loop = LOOP_NO_EMPTY_SIZE; /* Do not bail out on ENOSPC since we can do more. */ if (ret < 0 && ret != -ENOSPC) btrfs_abort_transaction(trans, ret); else ret = 0; if (!exist) btrfs_end_transaction(trans); if (ret) return ret; } if (ffe_ctl->loop == LOOP_NO_EMPTY_SIZE) { /* * Don't loop again if we already have no empty_size and * no empty_cluster. */ if (ffe_ctl->empty_size == 0 && ffe_ctl->empty_cluster == 0) return -ENOSPC; ffe_ctl->empty_size = 0; ffe_ctl->empty_cluster = 0; } return 1; } return -ENOSPC; } /* * walks the btree of allocated extents and find a hole of a given size. * The key ins is changed to record the hole: * ins->objectid == start position * ins->flags = BTRFS_EXTENT_ITEM_KEY * ins->offset == the size of the hole. * Any available blocks before search_start are skipped. * * If there is no suitable free space, we will record the max size of * the free space extent currently. * * The overall logic and call chain: * * find_free_extent() * |- Iterate through all block groups * | |- Get a valid block group * | |- Try to do clustered allocation in that block group * | |- Try to do unclustered allocation in that block group * | |- Check if the result is valid * | | |- If valid, then exit * | |- Jump to next block group * | * |- Push harder to find free extents * |- If not found, re-iterate all block groups */ static noinline int find_free_extent(struct btrfs_fs_info *fs_info, u64 ram_bytes, u64 num_bytes, u64 empty_size, u64 hint_byte, struct btrfs_key *ins, u64 flags, int delalloc) { int ret = 0; struct btrfs_free_cluster *last_ptr = NULL; struct btrfs_block_group_cache *block_group = NULL; struct find_free_extent_ctl ffe_ctl = {0}; struct btrfs_space_info *space_info; bool use_cluster = true; bool full_search = false; WARN_ON(num_bytes < fs_info->sectorsize); ffe_ctl.ram_bytes = ram_bytes; ffe_ctl.num_bytes = num_bytes; ffe_ctl.empty_size = empty_size; ffe_ctl.flags = flags; ffe_ctl.search_start = 0; ffe_ctl.retry_clustered = false; ffe_ctl.retry_unclustered = false; ffe_ctl.delalloc = delalloc; ffe_ctl.index = btrfs_bg_flags_to_raid_index(flags); ffe_ctl.have_caching_bg = false; ffe_ctl.orig_have_caching_bg = false; ffe_ctl.found_offset = 0; ins->type = BTRFS_EXTENT_ITEM_KEY; ins->objectid = 0; ins->offset = 0; trace_find_free_extent(fs_info, num_bytes, empty_size, flags); space_info = btrfs_find_space_info(fs_info, flags); if (!space_info) { btrfs_err(fs_info, "No space info for %llu", flags); return -ENOSPC; } /* * If our free space is heavily fragmented we may not be able to make * big contiguous allocations, so instead of doing the expensive search * for free space, simply return ENOSPC with our max_extent_size so we * can go ahead and search for a more manageable chunk. * * If our max_extent_size is large enough for our allocation simply * disable clustering since we will likely not be able to find enough * space to create a cluster and induce latency trying. */ if (unlikely(space_info->max_extent_size)) { spin_lock(&space_info->lock); if (space_info->max_extent_size && num_bytes > space_info->max_extent_size) { ins->offset = space_info->max_extent_size; spin_unlock(&space_info->lock); return -ENOSPC; } else if (space_info->max_extent_size) { use_cluster = false; } spin_unlock(&space_info->lock); } last_ptr = fetch_cluster_info(fs_info, space_info, &ffe_ctl.empty_cluster); if (last_ptr) { spin_lock(&last_ptr->lock); if (last_ptr->block_group) hint_byte = last_ptr->window_start; if (last_ptr->fragmented) { /* * We still set window_start so we can keep track of the * last place we found an allocation to try and save * some time. */ hint_byte = last_ptr->window_start; use_cluster = false; } spin_unlock(&last_ptr->lock); } ffe_ctl.search_start = max(ffe_ctl.search_start, first_logical_byte(fs_info, 0)); ffe_ctl.search_start = max(ffe_ctl.search_start, hint_byte); if (ffe_ctl.search_start == hint_byte) { block_group = btrfs_lookup_block_group(fs_info, ffe_ctl.search_start); /* * we don't want to use the block group if it doesn't match our * allocation bits, or if its not cached. * * However if we are re-searching with an ideal block group * picked out then we don't care that the block group is cached. */ if (block_group && block_group_bits(block_group, flags) && block_group->cached != BTRFS_CACHE_NO) { down_read(&space_info->groups_sem); if (list_empty(&block_group->list) || block_group->ro) { /* * someone is removing this block group, * we can't jump into the have_block_group * target because our list pointers are not * valid */ btrfs_put_block_group(block_group); up_read(&space_info->groups_sem); } else { ffe_ctl.index = btrfs_bg_flags_to_raid_index( block_group->flags); btrfs_lock_block_group(block_group, delalloc); goto have_block_group; } } else if (block_group) { btrfs_put_block_group(block_group); } } search: ffe_ctl.have_caching_bg = false; if (ffe_ctl.index == btrfs_bg_flags_to_raid_index(flags) || ffe_ctl.index == 0) full_search = true; down_read(&space_info->groups_sem); list_for_each_entry(block_group, &space_info->block_groups[ffe_ctl.index], list) { /* If the block group is read-only, we can skip it entirely. */ if (unlikely(block_group->ro)) continue; btrfs_grab_block_group(block_group, delalloc); ffe_ctl.search_start = block_group->key.objectid; /* * this can happen if we end up cycling through all the * raid types, but we want to make sure we only allocate * for the proper type. */ if (!block_group_bits(block_group, flags)) { u64 extra = BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID56_MASK | BTRFS_BLOCK_GROUP_RAID10; /* * if they asked for extra copies and this block group * doesn't provide them, bail. This does allow us to * fill raid0 from raid1. */ if ((flags & extra) && !(block_group->flags & extra)) goto loop; /* * This block group has different flags than we want. * It's possible that we have MIXED_GROUP flag but no * block group is mixed. Just skip such block group. */ btrfs_release_block_group(block_group, delalloc); continue; } have_block_group: ffe_ctl.cached = btrfs_block_group_cache_done(block_group); if (unlikely(!ffe_ctl.cached)) { ffe_ctl.have_caching_bg = true; ret = btrfs_cache_block_group(block_group, 0); BUG_ON(ret < 0); ret = 0; } if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) goto loop; /* * Ok we want to try and use the cluster allocator, so * lets look there */ if (last_ptr && use_cluster) { struct btrfs_block_group_cache *cluster_bg = NULL; ret = find_free_extent_clustered(block_group, last_ptr, &ffe_ctl, &cluster_bg); if (ret == 0) { if (cluster_bg && cluster_bg != block_group) { btrfs_release_block_group(block_group, delalloc); block_group = cluster_bg; } goto checks; } else if (ret == -EAGAIN) { goto have_block_group; } else if (ret > 0) { goto loop; } /* ret == -ENOENT case falls through */ } ret = find_free_extent_unclustered(block_group, last_ptr, &ffe_ctl); if (ret == -EAGAIN) goto have_block_group; else if (ret > 0) goto loop; /* ret == 0 case falls through */ checks: ffe_ctl.search_start = round_up(ffe_ctl.found_offset, fs_info->stripesize); /* move on to the next group */ if (ffe_ctl.search_start + num_bytes > block_group->key.objectid + block_group->key.offset) { btrfs_add_free_space(block_group, ffe_ctl.found_offset, num_bytes); goto loop; } if (ffe_ctl.found_offset < ffe_ctl.search_start) btrfs_add_free_space(block_group, ffe_ctl.found_offset, ffe_ctl.search_start - ffe_ctl.found_offset); ret = btrfs_add_reserved_bytes(block_group, ram_bytes, num_bytes, delalloc); if (ret == -EAGAIN) { btrfs_add_free_space(block_group, ffe_ctl.found_offset, num_bytes); goto loop; } btrfs_inc_block_group_reservations(block_group); /* we are all good, lets return */ ins->objectid = ffe_ctl.search_start; ins->offset = num_bytes; trace_btrfs_reserve_extent(block_group, ffe_ctl.search_start, num_bytes); btrfs_release_block_group(block_group, delalloc); break; loop: ffe_ctl.retry_clustered = false; ffe_ctl.retry_unclustered = false; BUG_ON(btrfs_bg_flags_to_raid_index(block_group->flags) != ffe_ctl.index); btrfs_release_block_group(block_group, delalloc); cond_resched(); } up_read(&space_info->groups_sem); ret = find_free_extent_update_loop(fs_info, last_ptr, ins, &ffe_ctl, full_search, use_cluster); if (ret > 0) goto search; if (ret == -ENOSPC) { /* * Use ffe_ctl->total_free_space as fallback if we can't find * any contiguous hole. */ if (!ffe_ctl.max_extent_size) ffe_ctl.max_extent_size = ffe_ctl.total_free_space; spin_lock(&space_info->lock); space_info->max_extent_size = ffe_ctl.max_extent_size; spin_unlock(&space_info->lock); ins->offset = ffe_ctl.max_extent_size; } return ret; } /* * btrfs_reserve_extent - entry point to the extent allocator. Tries to find a * hole that is at least as big as @num_bytes. * * @root - The root that will contain this extent * * @ram_bytes - The amount of space in ram that @num_bytes take. This * is used for accounting purposes. This value differs * from @num_bytes only in the case of compressed extents. * * @num_bytes - Number of bytes to allocate on-disk. * * @min_alloc_size - Indicates the minimum amount of space that the * allocator should try to satisfy. In some cases * @num_bytes may be larger than what is required and if * the filesystem is fragmented then allocation fails. * However, the presence of @min_alloc_size gives a * chance to try and satisfy the smaller allocation. * * @empty_size - A hint that you plan on doing more COW. This is the * size in bytes the allocator should try to find free * next to the block it returns. This is just a hint and * may be ignored by the allocator. * * @hint_byte - Hint to the allocator to start searching above the byte * address passed. It might be ignored. * * @ins - This key is modified to record the found hole. It will * have the following values: * ins->objectid == start position * ins->flags = BTRFS_EXTENT_ITEM_KEY * ins->offset == the size of the hole. * * @is_data - Boolean flag indicating whether an extent is * allocated for data (true) or metadata (false) * * @delalloc - Boolean flag indicating whether this allocation is for * delalloc or not. If 'true' data_rwsem of block groups * is going to be acquired. * * * Returns 0 when an allocation succeeded or < 0 when an error occurred. In * case -ENOSPC is returned then @ins->offset will contain the size of the * largest available hole the allocator managed to find. */ int btrfs_reserve_extent(struct btrfs_root *root, u64 ram_bytes, u64 num_bytes, u64 min_alloc_size, u64 empty_size, u64 hint_byte, struct btrfs_key *ins, int is_data, int delalloc) { struct btrfs_fs_info *fs_info = root->fs_info; bool final_tried = num_bytes == min_alloc_size; u64 flags; int ret; flags = get_alloc_profile_by_root(root, is_data); again: WARN_ON(num_bytes < fs_info->sectorsize); ret = find_free_extent(fs_info, ram_bytes, num_bytes, empty_size, hint_byte, ins, flags, delalloc); if (!ret && !is_data) { btrfs_dec_block_group_reservations(fs_info, ins->objectid); } else if (ret == -ENOSPC) { if (!final_tried && ins->offset) { num_bytes = min(num_bytes >> 1, ins->offset); num_bytes = round_down(num_bytes, fs_info->sectorsize); num_bytes = max(num_bytes, min_alloc_size); ram_bytes = num_bytes; if (num_bytes == min_alloc_size) final_tried = true; goto again; } else if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { struct btrfs_space_info *sinfo; sinfo = btrfs_find_space_info(fs_info, flags); btrfs_err(fs_info, "allocation failed flags %llu, wanted %llu", flags, num_bytes); if (sinfo) btrfs_dump_space_info(fs_info, sinfo, num_bytes, 1); } } return ret; } static int __btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len, int pin, int delalloc) { struct btrfs_block_group_cache *cache; int ret = 0; cache = btrfs_lookup_block_group(fs_info, start); if (!cache) { btrfs_err(fs_info, "Unable to find block group for %llu", start); return -ENOSPC; } if (pin) pin_down_extent(cache, start, len, 1); else { if (btrfs_test_opt(fs_info, DISCARD)) ret = btrfs_discard_extent(fs_info, start, len, NULL); btrfs_add_free_space(cache, start, len); btrfs_free_reserved_bytes(cache, len, delalloc); trace_btrfs_reserved_extent_free(fs_info, start, len); } btrfs_put_block_group(cache); return ret; } int btrfs_free_reserved_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len, int delalloc) { return __btrfs_free_reserved_extent(fs_info, start, len, 0, delalloc); } int btrfs_free_and_pin_reserved_extent(struct btrfs_fs_info *fs_info, u64 start, u64 len) { return __btrfs_free_reserved_extent(fs_info, start, len, 1, 0); } static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, u64 parent, u64 root_objectid, u64 flags, u64 owner, u64 offset, struct btrfs_key *ins, int ref_mod) { struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_extent_item *extent_item; struct btrfs_extent_inline_ref *iref; struct btrfs_path *path; struct extent_buffer *leaf; int type; u32 size; if (parent > 0) type = BTRFS_SHARED_DATA_REF_KEY; else type = BTRFS_EXTENT_DATA_REF_KEY; size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type); path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, ins, size); if (ret) { btrfs_free_path(path); return ret; } leaf = path->nodes[0]; extent_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); btrfs_set_extent_refs(leaf, extent_item, ref_mod); btrfs_set_extent_generation(leaf, extent_item, trans->transid); btrfs_set_extent_flags(leaf, extent_item, flags | BTRFS_EXTENT_FLAG_DATA); iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); btrfs_set_extent_inline_ref_type(leaf, iref, type); if (parent > 0) { struct btrfs_shared_data_ref *ref; ref = (struct btrfs_shared_data_ref *)(iref + 1); btrfs_set_extent_inline_ref_offset(leaf, iref, parent); btrfs_set_shared_data_ref_count(leaf, ref, ref_mod); } else { struct btrfs_extent_data_ref *ref; ref = (struct btrfs_extent_data_ref *)(&iref->offset); btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); btrfs_set_extent_data_ref_objectid(leaf, ref, owner); btrfs_set_extent_data_ref_offset(leaf, ref, offset); btrfs_set_extent_data_ref_count(leaf, ref, ref_mod); } btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_free_path(path); ret = remove_from_free_space_tree(trans, ins->objectid, ins->offset); if (ret) return ret; ret = update_block_group(trans, ins->objectid, ins->offset, 1); if (ret) { /* -ENOENT, logic error */ btrfs_err(fs_info, "update block group failed for %llu %llu", ins->objectid, ins->offset); BUG(); } trace_btrfs_reserved_extent_alloc(fs_info, ins->objectid, ins->offset); return ret; } static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_extent_item *extent_item; struct btrfs_key extent_key; struct btrfs_tree_block_info *block_info; struct btrfs_extent_inline_ref *iref; struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_delayed_tree_ref *ref; u32 size = sizeof(*extent_item) + sizeof(*iref); u64 num_bytes; u64 flags = extent_op->flags_to_set; bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); ref = btrfs_delayed_node_to_tree_ref(node); extent_key.objectid = node->bytenr; if (skinny_metadata) { extent_key.offset = ref->level; extent_key.type = BTRFS_METADATA_ITEM_KEY; num_bytes = fs_info->nodesize; } else { extent_key.offset = node->num_bytes; extent_key.type = BTRFS_EXTENT_ITEM_KEY; size += sizeof(*block_info); num_bytes = node->num_bytes; } path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, &extent_key, size); if (ret) { btrfs_free_path(path); return ret; } leaf = path->nodes[0]; extent_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); btrfs_set_extent_refs(leaf, extent_item, 1); btrfs_set_extent_generation(leaf, extent_item, trans->transid); btrfs_set_extent_flags(leaf, extent_item, flags | BTRFS_EXTENT_FLAG_TREE_BLOCK); if (skinny_metadata) { iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); } else { block_info = (struct btrfs_tree_block_info *)(extent_item + 1); btrfs_set_tree_block_key(leaf, block_info, &extent_op->key); btrfs_set_tree_block_level(leaf, block_info, ref->level); iref = (struct btrfs_extent_inline_ref *)(block_info + 1); } if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) { BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_SHARED_BLOCK_REF_KEY); btrfs_set_extent_inline_ref_offset(leaf, iref, ref->parent); } else { btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY); btrfs_set_extent_inline_ref_offset(leaf, iref, ref->root); } btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); ret = remove_from_free_space_tree(trans, extent_key.objectid, num_bytes); if (ret) return ret; ret = update_block_group(trans, extent_key.objectid, fs_info->nodesize, 1); if (ret) { /* -ENOENT, logic error */ btrfs_err(fs_info, "update block group failed for %llu %llu", extent_key.objectid, extent_key.offset); BUG(); } trace_btrfs_reserved_extent_alloc(fs_info, extent_key.objectid, fs_info->nodesize); return ret; } int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 owner, u64 offset, u64 ram_bytes, struct btrfs_key *ins) { struct btrfs_ref generic_ref = { 0 }; int ret; BUG_ON(root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID); btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT, ins->objectid, ins->offset, 0); btrfs_init_data_ref(&generic_ref, root->root_key.objectid, owner, offset); btrfs_ref_tree_mod(root->fs_info, &generic_ref); ret = btrfs_add_delayed_data_ref(trans, &generic_ref, ram_bytes, NULL, NULL); return ret; } /* * this is used by the tree logging recovery code. It records that * an extent has been allocated and makes sure to clear the free * space cache bits as well */ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, u64 root_objectid, u64 owner, u64 offset, struct btrfs_key *ins) { struct btrfs_fs_info *fs_info = trans->fs_info; int ret; struct btrfs_block_group_cache *block_group; struct btrfs_space_info *space_info; /* * Mixed block groups will exclude before processing the log so we only * need to do the exclude dance if this fs isn't mixed. */ if (!btrfs_fs_incompat(fs_info, MIXED_GROUPS)) { ret = __exclude_logged_extent(fs_info, ins->objectid, ins->offset); if (ret) return ret; } block_group = btrfs_lookup_block_group(fs_info, ins->objectid); if (!block_group) return -EINVAL; space_info = block_group->space_info; spin_lock(&space_info->lock); spin_lock(&block_group->lock); space_info->bytes_reserved += ins->offset; block_group->reserved += ins->offset; spin_unlock(&block_group->lock); spin_unlock(&space_info->lock); ret = alloc_reserved_file_extent(trans, 0, root_objectid, 0, owner, offset, ins, 1); btrfs_put_block_group(block_group); return ret; } static struct extent_buffer * btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, int level, u64 owner) { struct btrfs_fs_info *fs_info = root->fs_info; struct extent_buffer *buf; buf = btrfs_find_create_tree_block(fs_info, bytenr); if (IS_ERR(buf)) return buf; /* * Extra safety check in case the extent tree is corrupted and extent * allocator chooses to use a tree block which is already used and * locked. */ if (buf->lock_owner == current->pid) { btrfs_err_rl(fs_info, "tree block %llu owner %llu already locked by pid=%d, extent tree corruption detected", buf->start, btrfs_header_owner(buf), current->pid); free_extent_buffer(buf); return ERR_PTR(-EUCLEAN); } btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level); btrfs_tree_lock(buf); btrfs_clean_tree_block(buf); clear_bit(EXTENT_BUFFER_STALE, &buf->bflags); btrfs_set_lock_blocking_write(buf); set_extent_buffer_uptodate(buf); memzero_extent_buffer(buf, 0, sizeof(struct btrfs_header)); btrfs_set_header_level(buf, level); btrfs_set_header_bytenr(buf, buf->start); btrfs_set_header_generation(buf, trans->transid); btrfs_set_header_backref_rev(buf, BTRFS_MIXED_BACKREF_REV); btrfs_set_header_owner(buf, owner); write_extent_buffer_fsid(buf, fs_info->fs_devices->metadata_uuid); write_extent_buffer_chunk_tree_uuid(buf, fs_info->chunk_tree_uuid); if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { buf->log_index = root->log_transid % 2; /* * we allow two log transactions at a time, use different * EXTENT bit to differentiate dirty pages. */ if (buf->log_index == 0) set_extent_dirty(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); else set_extent_new(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1); } else { buf->log_index = -1; set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } trans->dirty = true; /* this returns a buffer locked for blocking */ return buf; } /* * finds a free extent and does all the dirty work required for allocation * returns the tree buffer or an ERR_PTR on error. */ struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 parent, u64 root_objectid, const struct btrfs_disk_key *key, int level, u64 hint, u64 empty_size) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_key ins; struct btrfs_block_rsv *block_rsv; struct extent_buffer *buf; struct btrfs_delayed_extent_op *extent_op; struct btrfs_ref generic_ref = { 0 }; u64 flags = 0; int ret; u32 blocksize = fs_info->nodesize; bool skinny_metadata = btrfs_fs_incompat(fs_info, SKINNY_METADATA); #ifdef CONFIG_BTRFS_FS_RUN_SANITY_TESTS if (btrfs_is_testing(fs_info)) { buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr, level, root_objectid); if (!IS_ERR(buf)) root->alloc_bytenr += blocksize; return buf; } #endif block_rsv = btrfs_use_block_rsv(trans, root, blocksize); if (IS_ERR(block_rsv)) return ERR_CAST(block_rsv); ret = btrfs_reserve_extent(root, blocksize, blocksize, blocksize, empty_size, hint, &ins, 0, 0); if (ret) goto out_unuse; buf = btrfs_init_new_buffer(trans, root, ins.objectid, level, root_objectid); if (IS_ERR(buf)) { ret = PTR_ERR(buf); goto out_free_reserved; } if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) { if (parent == 0) parent = ins.objectid; flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; } else BUG_ON(parent > 0); if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { extent_op = btrfs_alloc_delayed_extent_op(); if (!extent_op) { ret = -ENOMEM; goto out_free_buf; } if (key) memcpy(&extent_op->key, key, sizeof(extent_op->key)); else memset(&extent_op->key, 0, sizeof(extent_op->key)); extent_op->flags_to_set = flags; extent_op->update_key = skinny_metadata ? false : true; extent_op->update_flags = true; extent_op->is_data = false; extent_op->level = level; btrfs_init_generic_ref(&generic_ref, BTRFS_ADD_DELAYED_EXTENT, ins.objectid, ins.offset, parent); generic_ref.real_root = root->root_key.objectid; btrfs_init_tree_ref(&generic_ref, level, root_objectid); btrfs_ref_tree_mod(fs_info, &generic_ref); ret = btrfs_add_delayed_tree_ref(trans, &generic_ref, extent_op, NULL, NULL); if (ret) goto out_free_delayed; } return buf; out_free_delayed: btrfs_free_delayed_extent_op(extent_op); out_free_buf: free_extent_buffer(buf); out_free_reserved: btrfs_free_reserved_extent(fs_info, ins.objectid, ins.offset, 0); out_unuse: btrfs_unuse_block_rsv(fs_info, block_rsv, blocksize); return ERR_PTR(ret); } struct walk_control { u64 refs[BTRFS_MAX_LEVEL]; u64 flags[BTRFS_MAX_LEVEL]; struct btrfs_key update_progress; struct btrfs_key drop_progress; int drop_level; int stage; int level; int shared_level; int update_ref; int keep_locks; int reada_slot; int reada_count; int restarted; }; #define DROP_REFERENCE 1 #define UPDATE_BACKREF 2 static noinline void reada_walk_down(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct walk_control *wc, struct btrfs_path *path) { struct btrfs_fs_info *fs_info = root->fs_info; u64 bytenr; u64 generation; u64 refs; u64 flags; u32 nritems; struct btrfs_key key; struct extent_buffer *eb; int ret; int slot; int nread = 0; if (path->slots[wc->level] < wc->reada_slot) { wc->reada_count = wc->reada_count * 2 / 3; wc->reada_count = max(wc->reada_count, 2); } else { wc->reada_count = wc->reada_count * 3 / 2; wc->reada_count = min_t(int, wc->reada_count, BTRFS_NODEPTRS_PER_BLOCK(fs_info)); } eb = path->nodes[wc->level]; nritems = btrfs_header_nritems(eb); for (slot = path->slots[wc->level]; slot < nritems; slot++) { if (nread >= wc->reada_count) break; cond_resched(); bytenr = btrfs_node_blockptr(eb, slot); generation = btrfs_node_ptr_generation(eb, slot); if (slot == path->slots[wc->level]) goto reada; if (wc->stage == UPDATE_BACKREF && generation <= root->root_key.offset) continue; /* We don't lock the tree block, it's OK to be racy here */ ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, wc->level - 1, 1, &refs, &flags); /* We don't care about errors in readahead. */ if (ret < 0) continue; BUG_ON(refs == 0); if (wc->stage == DROP_REFERENCE) { if (refs == 1) goto reada; if (wc->level == 1 && (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) continue; if (!wc->update_ref || generation <= root->root_key.offset) continue; btrfs_node_key_to_cpu(eb, &key, slot); ret = btrfs_comp_cpu_keys(&key, &wc->update_progress); if (ret < 0) continue; } else { if (wc->level == 1 && (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) continue; } reada: readahead_tree_block(fs_info, bytenr); nread++; } wc->reada_slot = slot; } /* * helper to process tree block while walking down the tree. * * when wc->stage == UPDATE_BACKREF, this function updates * back refs for pointers in the block. * * NOTE: return value 1 means we should stop walking down. */ static noinline int walk_down_proc(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int lookup_info) { struct btrfs_fs_info *fs_info = root->fs_info; int level = wc->level; struct extent_buffer *eb = path->nodes[level]; u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF; int ret; if (wc->stage == UPDATE_BACKREF && btrfs_header_owner(eb) != root->root_key.objectid) return 1; /* * when reference count of tree block is 1, it won't increase * again. once full backref flag is set, we never clear it. */ if (lookup_info && ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) { BUG_ON(!path->locks[level]); ret = btrfs_lookup_extent_info(trans, fs_info, eb->start, level, 1, &wc->refs[level], &wc->flags[level]); BUG_ON(ret == -ENOMEM); if (ret) return ret; BUG_ON(wc->refs[level] == 0); } if (wc->stage == DROP_REFERENCE) { if (wc->refs[level] > 1) return 1; if (path->locks[level] && !wc->keep_locks) { btrfs_tree_unlock_rw(eb, path->locks[level]); path->locks[level] = 0; } return 0; } /* wc->stage == UPDATE_BACKREF */ if (!(wc->flags[level] & flag)) { BUG_ON(!path->locks[level]); ret = btrfs_inc_ref(trans, root, eb, 1); BUG_ON(ret); /* -ENOMEM */ ret = btrfs_dec_ref(trans, root, eb, 0); BUG_ON(ret); /* -ENOMEM */ ret = btrfs_set_disk_extent_flags(trans, eb->start, eb->len, flag, btrfs_header_level(eb), 0); BUG_ON(ret); /* -ENOMEM */ wc->flags[level] |= flag; } /* * the block is shared by multiple trees, so it's not good to * keep the tree lock */ if (path->locks[level] && level > 0) { btrfs_tree_unlock_rw(eb, path->locks[level]); path->locks[level] = 0; } return 0; } /* * This is used to verify a ref exists for this root to deal with a bug where we * would have a drop_progress key that hadn't been updated properly. */ static int check_ref_exists(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 parent, int level) { struct btrfs_path *path; struct btrfs_extent_inline_ref *iref; int ret; path = btrfs_alloc_path(); if (!path) return -ENOMEM; ret = lookup_extent_backref(trans, path, &iref, bytenr, root->fs_info->nodesize, parent, root->root_key.objectid, level, 0); btrfs_free_path(path); if (ret == -ENOENT) return 0; if (ret < 0) return ret; return 1; } /* * helper to process tree block pointer. * * when wc->stage == DROP_REFERENCE, this function checks * reference count of the block pointed to. if the block * is shared and we need update back refs for the subtree * rooted at the block, this function changes wc->stage to * UPDATE_BACKREF. if the block is shared and there is no * need to update back, this function drops the reference * to the block. * * NOTE: return value 1 means we should stop walking down. */ static noinline int do_walk_down(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int *lookup_info) { struct btrfs_fs_info *fs_info = root->fs_info; u64 bytenr; u64 generation; u64 parent; struct btrfs_key key; struct btrfs_key first_key; struct btrfs_ref ref = { 0 }; struct extent_buffer *next; int level = wc->level; int reada = 0; int ret = 0; bool need_account = false; generation = btrfs_node_ptr_generation(path->nodes[level], path->slots[level]); /* * if the lower level block was created before the snapshot * was created, we know there is no need to update back refs * for the subtree */ if (wc->stage == UPDATE_BACKREF && generation <= root->root_key.offset) { *lookup_info = 1; return 1; } bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); btrfs_node_key_to_cpu(path->nodes[level], &first_key, path->slots[level]); next = find_extent_buffer(fs_info, bytenr); if (!next) { next = btrfs_find_create_tree_block(fs_info, bytenr); if (IS_ERR(next)) return PTR_ERR(next); btrfs_set_buffer_lockdep_class(root->root_key.objectid, next, level - 1); reada = 1; } btrfs_tree_lock(next); btrfs_set_lock_blocking_write(next); ret = btrfs_lookup_extent_info(trans, fs_info, bytenr, level - 1, 1, &wc->refs[level - 1], &wc->flags[level - 1]); if (ret < 0) goto out_unlock; if (unlikely(wc->refs[level - 1] == 0)) { btrfs_err(fs_info, "Missing references."); ret = -EIO; goto out_unlock; } *lookup_info = 0; if (wc->stage == DROP_REFERENCE) { if (wc->refs[level - 1] > 1) { need_account = true; if (level == 1 && (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) goto skip; if (!wc->update_ref || generation <= root->root_key.offset) goto skip; btrfs_node_key_to_cpu(path->nodes[level], &key, path->slots[level]); ret = btrfs_comp_cpu_keys(&key, &wc->update_progress); if (ret < 0) goto skip; wc->stage = UPDATE_BACKREF; wc->shared_level = level - 1; } } else { if (level == 1 && (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) goto skip; } if (!btrfs_buffer_uptodate(next, generation, 0)) { btrfs_tree_unlock(next); free_extent_buffer(next); next = NULL; *lookup_info = 1; } if (!next) { if (reada && level == 1) reada_walk_down(trans, root, wc, path); next = read_tree_block(fs_info, bytenr, generation, level - 1, &first_key); if (IS_ERR(next)) { return PTR_ERR(next); } else if (!extent_buffer_uptodate(next)) { free_extent_buffer(next); return -EIO; } btrfs_tree_lock(next); btrfs_set_lock_blocking_write(next); } level--; ASSERT(level == btrfs_header_level(next)); if (level != btrfs_header_level(next)) { btrfs_err(root->fs_info, "mismatched level"); ret = -EIO; goto out_unlock; } path->nodes[level] = next; path->slots[level] = 0; path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; wc->level = level; if (wc->level == 1) wc->reada_slot = 0; return 0; skip: wc->refs[level - 1] = 0; wc->flags[level - 1] = 0; if (wc->stage == DROP_REFERENCE) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { parent = path->nodes[level]->start; } else { ASSERT(root->root_key.objectid == btrfs_header_owner(path->nodes[level])); if (root->root_key.objectid != btrfs_header_owner(path->nodes[level])) { btrfs_err(root->fs_info, "mismatched block owner"); ret = -EIO; goto out_unlock; } parent = 0; } /* * If we had a drop_progress we need to verify the refs are set * as expected. If we find our ref then we know that from here * on out everything should be correct, and we can clear the * ->restarted flag. */ if (wc->restarted) { ret = check_ref_exists(trans, root, bytenr, parent, level - 1); if (ret < 0) goto out_unlock; if (ret == 0) goto no_delete; ret = 0; wc->restarted = 0; } /* * Reloc tree doesn't contribute to qgroup numbers, and we have * already accounted them at merge time (replace_path), * thus we could skip expensive subtree trace here. */ if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID && need_account) { ret = btrfs_qgroup_trace_subtree(trans, next, generation, level - 1); if (ret) { btrfs_err_rl(fs_info, "Error %d accounting shared subtree. Quota is out of sync, rescan required.", ret); } } /* * We need to update the next key in our walk control so we can * update the drop_progress key accordingly. We don't care if * find_next_key doesn't find a key because that means we're at * the end and are going to clean up now. */ wc->drop_level = level; find_next_key(path, level, &wc->drop_progress); btrfs_init_generic_ref(&ref, BTRFS_DROP_DELAYED_REF, bytenr, fs_info->nodesize, parent); btrfs_init_tree_ref(&ref, level - 1, root->root_key.objectid); ret = btrfs_free_extent(trans, &ref); if (ret) goto out_unlock; } no_delete: *lookup_info = 1; ret = 1; out_unlock: btrfs_tree_unlock(next); free_extent_buffer(next); return ret; } /* * helper to process tree block while walking up the tree. * * when wc->stage == DROP_REFERENCE, this function drops * reference count on the block. * * when wc->stage == UPDATE_BACKREF, this function changes * wc->stage back to DROP_REFERENCE if we changed wc->stage * to UPDATE_BACKREF previously while processing the block. * * NOTE: return value 1 means we should stop walking up. */ static noinline int walk_up_proc(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc) { struct btrfs_fs_info *fs_info = root->fs_info; int ret; int level = wc->level; struct extent_buffer *eb = path->nodes[level]; u64 parent = 0; if (wc->stage == UPDATE_BACKREF) { BUG_ON(wc->shared_level < level); if (level < wc->shared_level) goto out; ret = find_next_key(path, level + 1, &wc->update_progress); if (ret > 0) wc->update_ref = 0; wc->stage = DROP_REFERENCE; wc->shared_level = -1; path->slots[level] = 0; /* * check reference count again if the block isn't locked. * we should start walking down the tree again if reference * count is one. */ if (!path->locks[level]) { BUG_ON(level == 0); btrfs_tree_lock(eb); btrfs_set_lock_blocking_write(eb); path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; ret = btrfs_lookup_extent_info(trans, fs_info, eb->start, level, 1, &wc->refs[level], &wc->flags[level]); if (ret < 0) { btrfs_tree_unlock_rw(eb, path->locks[level]); path->locks[level] = 0; return ret; } BUG_ON(wc->refs[level] == 0); if (wc->refs[level] == 1) { btrfs_tree_unlock_rw(eb, path->locks[level]); path->locks[level] = 0; return 1; } } } /* wc->stage == DROP_REFERENCE */ BUG_ON(wc->refs[level] > 1 && !path->locks[level]); if (wc->refs[level] == 1) { if (level == 0) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) ret = btrfs_dec_ref(trans, root, eb, 1); else ret = btrfs_dec_ref(trans, root, eb, 0); BUG_ON(ret); /* -ENOMEM */ if (is_fstree(root->root_key.objectid)) { ret = btrfs_qgroup_trace_leaf_items(trans, eb); if (ret) { btrfs_err_rl(fs_info, "error %d accounting leaf items, quota is out of sync, rescan required", ret); } } } /* make block locked assertion in btrfs_clean_tree_block happy */ if (!path->locks[level] && btrfs_header_generation(eb) == trans->transid) { btrfs_tree_lock(eb); btrfs_set_lock_blocking_write(eb); path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; } btrfs_clean_tree_block(eb); } if (eb == root->node) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = eb->start; else if (root->root_key.objectid != btrfs_header_owner(eb)) goto owner_mismatch; } else { if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = path->nodes[level + 1]->start; else if (root->root_key.objectid != btrfs_header_owner(path->nodes[level + 1])) goto owner_mismatch; } btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1); out: wc->refs[level] = 0; wc->flags[level] = 0; return 0; owner_mismatch: btrfs_err_rl(fs_info, "unexpected tree owner, have %llu expect %llu", btrfs_header_owner(eb), root->root_key.objectid); return -EUCLEAN; } static noinline int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc) { int level = wc->level; int lookup_info = 1; int ret; while (level >= 0) { ret = walk_down_proc(trans, root, path, wc, lookup_info); if (ret > 0) break; if (level == 0) break; if (path->slots[level] >= btrfs_header_nritems(path->nodes[level])) break; ret = do_walk_down(trans, root, path, wc, &lookup_info); if (ret > 0) { path->slots[level]++; continue; } else if (ret < 0) return ret; level = wc->level; } return 0; } static noinline int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int max_level) { int level = wc->level; int ret; path->slots[level] = btrfs_header_nritems(path->nodes[level]); while (level < max_level && path->nodes[level]) { wc->level = level; if (path->slots[level] + 1 < btrfs_header_nritems(path->nodes[level])) { path->slots[level]++; return 0; } else { ret = walk_up_proc(trans, root, path, wc); if (ret > 0) return 0; if (ret < 0) return ret; if (path->locks[level]) { btrfs_tree_unlock_rw(path->nodes[level], path->locks[level]); path->locks[level] = 0; } free_extent_buffer(path->nodes[level]); path->nodes[level] = NULL; level++; } } return 1; } /* * drop a subvolume tree. * * this function traverses the tree freeing any blocks that only * referenced by the tree. * * when a shared tree block is found. this function decreases its * reference count by one. if update_ref is true, this function * also make sure backrefs for the shared block and all lower level * blocks are properly updated. * * If called with for_reloc == 0, may exit early with -EAGAIN */ int btrfs_drop_snapshot(struct btrfs_root *root, struct btrfs_block_rsv *block_rsv, int update_ref, int for_reloc) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_path *path; struct btrfs_trans_handle *trans; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_root_item *root_item = &root->root_item; struct walk_control *wc; struct btrfs_key key; int err = 0; int ret; int level; bool root_dropped = false; btrfs_debug(fs_info, "Drop subvolume %llu", root->root_key.objectid); path = btrfs_alloc_path(); if (!path) { err = -ENOMEM; goto out; } wc = kzalloc(sizeof(*wc), GFP_NOFS); if (!wc) { btrfs_free_path(path); err = -ENOMEM; goto out; } trans = btrfs_start_transaction(tree_root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out_free; } err = btrfs_run_delayed_items(trans); if (err) goto out_end_trans; if (block_rsv) trans->block_rsv = block_rsv; /* * This will help us catch people modifying the fs tree while we're * dropping it. It is unsafe to mess with the fs tree while it's being * dropped as we unlock the root node and parent nodes as we walk down * the tree, assuming nothing will change. If something does change * then we'll have stale information and drop references to blocks we've * already dropped. */ set_bit(BTRFS_ROOT_DELETING, &root->state); if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { level = btrfs_header_level(root->node); path->nodes[level] = btrfs_lock_root_node(root); btrfs_set_lock_blocking_write(path->nodes[level]); path->slots[level] = 0; path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; memset(&wc->update_progress, 0, sizeof(wc->update_progress)); } else { btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); memcpy(&wc->update_progress, &key, sizeof(wc->update_progress)); level = root_item->drop_level; BUG_ON(level == 0); path->lowest_level = level; ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); path->lowest_level = 0; if (ret < 0) { err = ret; goto out_end_trans; } WARN_ON(ret > 0); /* * unlock our path, this is safe because only this * function is allowed to delete this snapshot */ btrfs_unlock_up_safe(path, 0); level = btrfs_header_level(root->node); while (1) { btrfs_tree_lock(path->nodes[level]); btrfs_set_lock_blocking_write(path->nodes[level]); path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; ret = btrfs_lookup_extent_info(trans, fs_info, path->nodes[level]->start, level, 1, &wc->refs[level], &wc->flags[level]); if (ret < 0) { err = ret; goto out_end_trans; } BUG_ON(wc->refs[level] == 0); if (level == root_item->drop_level) break; btrfs_tree_unlock(path->nodes[level]); path->locks[level] = 0; WARN_ON(wc->refs[level] != 1); level--; } } wc->restarted = test_bit(BTRFS_ROOT_DEAD_TREE, &root->state); wc->level = level; wc->shared_level = -1; wc->stage = DROP_REFERENCE; wc->update_ref = update_ref; wc->keep_locks = 0; wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info); while (1) { ret = walk_down_tree(trans, root, path, wc); if (ret < 0) { err = ret; break; } ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL); if (ret < 0) { err = ret; break; } if (ret > 0) { BUG_ON(wc->stage != DROP_REFERENCE); break; } if (wc->stage == DROP_REFERENCE) { wc->drop_level = wc->level; btrfs_node_key_to_cpu(path->nodes[wc->drop_level], &wc->drop_progress, path->slots[wc->drop_level]); } btrfs_cpu_key_to_disk(&root_item->drop_progress, &wc->drop_progress); root_item->drop_level = wc->drop_level; BUG_ON(wc->level == 0); if (btrfs_should_end_transaction(trans) || (!for_reloc && btrfs_need_cleaner_sleep(fs_info))) { ret = btrfs_update_root(trans, tree_root, &root->root_key, root_item); if (ret) { btrfs_abort_transaction(trans, ret); err = ret; goto out_end_trans; } btrfs_end_transaction_throttle(trans); if (!for_reloc && btrfs_need_cleaner_sleep(fs_info)) { btrfs_debug(fs_info, "drop snapshot early exit"); err = -EAGAIN; goto out_free; } trans = btrfs_start_transaction(tree_root, 0); if (IS_ERR(trans)) { err = PTR_ERR(trans); goto out_free; } if (block_rsv) trans->block_rsv = block_rsv; } } btrfs_release_path(path); if (err) goto out_end_trans; ret = btrfs_del_root(trans, &root->root_key); if (ret) { btrfs_abort_transaction(trans, ret); err = ret; goto out_end_trans; } if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { ret = btrfs_find_root(tree_root, &root->root_key, path, NULL, NULL); if (ret < 0) { btrfs_abort_transaction(trans, ret); err = ret; goto out_end_trans; } else if (ret > 0) { /* if we fail to delete the orphan item this time * around, it'll get picked up the next time. * * The most common failure here is just -ENOENT. */ btrfs_del_orphan_item(trans, tree_root, root->root_key.objectid); } } if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) { btrfs_add_dropped_root(trans, root); } else { free_extent_buffer(root->node); free_extent_buffer(root->commit_root); btrfs_put_fs_root(root); } root_dropped = true; out_end_trans: btrfs_end_transaction_throttle(trans); out_free: kfree(wc); btrfs_free_path(path); out: /* * So if we need to stop dropping the snapshot for whatever reason we * need to make sure to add it back to the dead root list so that we * keep trying to do the work later. This also cleans up roots if we * don't have it in the radix (like when we recover after a power fail * or unmount) so we don't leak memory. */ if (!for_reloc && !root_dropped) btrfs_add_dead_root(root); if (err && err != -EAGAIN) btrfs_handle_fs_error(fs_info, err, NULL); return err; } /* * drop subtree rooted at tree block 'node'. * * NOTE: this function will unlock and release tree block 'node' * only used by relocation code */ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *node, struct extent_buffer *parent) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_path *path; struct walk_control *wc; int level; int parent_level; int ret = 0; int wret; BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); path = btrfs_alloc_path(); if (!path) return -ENOMEM; wc = kzalloc(sizeof(*wc), GFP_NOFS); if (!wc) { btrfs_free_path(path); return -ENOMEM; } btrfs_assert_tree_locked(parent); parent_level = btrfs_header_level(parent); extent_buffer_get(parent); path->nodes[parent_level] = parent; path->slots[parent_level] = btrfs_header_nritems(parent); btrfs_assert_tree_locked(node); level = btrfs_header_level(node); path->nodes[level] = node; path->slots[level] = 0; path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; wc->refs[parent_level] = 1; wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF; wc->level = level; wc->shared_level = -1; wc->stage = DROP_REFERENCE; wc->update_ref = 0; wc->keep_locks = 1; wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(fs_info); while (1) { wret = walk_down_tree(trans, root, path, wc); if (wret < 0) { ret = wret; break; } wret = walk_up_tree(trans, root, path, wc, parent_level); if (wret < 0) ret = wret; if (wret != 0) break; } kfree(wc); btrfs_free_path(path); return ret; } static u64 update_block_group_flags(struct btrfs_fs_info *fs_info, u64 flags) { u64 num_devices; u64 stripped; /* * if restripe for this chunk_type is on pick target profile and * return, otherwise do the usual balance */ stripped = get_restripe_target(fs_info, flags); if (stripped) return extended_to_chunk(stripped); num_devices = fs_info->fs_devices->rw_devices; stripped = BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID56_MASK | BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10; if (num_devices == 1) { stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* turn raid0 into single device chunks */ if (flags & BTRFS_BLOCK_GROUP_RAID0) return stripped; /* turn mirroring into duplication */ if (flags & (BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID10)) return stripped | BTRFS_BLOCK_GROUP_DUP; } else { /* they already had raid on here, just return */ if (flags & stripped) return flags; stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* switch duplicated blocks with raid1 */ if (flags & BTRFS_BLOCK_GROUP_DUP) return stripped | BTRFS_BLOCK_GROUP_RAID1; /* this is drive concat, leave it alone */ } return flags; } /* * Mark block group @cache read-only, so later write won't happen to block * group @cache. * * If @force is not set, this function will only mark the block group readonly * if we have enough free space (1M) in other metadata/system block groups. * If @force is not set, this function will mark the block group readonly * without checking free space. * * NOTE: This function doesn't care if other block groups can contain all the * data in this block group. That check should be done by relocation routine, * not this function. */ static int inc_block_group_ro(struct btrfs_block_group_cache *cache, int force) { struct btrfs_space_info *sinfo = cache->space_info; u64 num_bytes; u64 sinfo_used; u64 min_allocable_bytes; int ret = -ENOSPC; /* * We need some metadata space and system metadata space for * allocating chunks in some corner cases until we force to set * it to be readonly. */ if ((sinfo->flags & (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) && !force) min_allocable_bytes = SZ_1M; else min_allocable_bytes = 0; spin_lock(&sinfo->lock); spin_lock(&cache->lock); if (cache->ro) { cache->ro++; ret = 0; goto out; } num_bytes = cache->key.offset - cache->reserved - cache->pinned - cache->bytes_super - btrfs_block_group_used(&cache->item); sinfo_used = btrfs_space_info_used(sinfo, true); /* * sinfo_used + num_bytes should always <= sinfo->total_bytes. * * Here we make sure if we mark this bg RO, we still have enough * free space as buffer (if min_allocable_bytes is not 0). */ if (sinfo_used + num_bytes + min_allocable_bytes <= sinfo->total_bytes) { sinfo->bytes_readonly += num_bytes; cache->ro++; list_add_tail(&cache->ro_list, &sinfo->ro_bgs); ret = 0; } out: spin_unlock(&cache->lock); spin_unlock(&sinfo->lock); if (ret == -ENOSPC && btrfs_test_opt(cache->fs_info, ENOSPC_DEBUG)) { btrfs_info(cache->fs_info, "unable to make block group %llu ro", cache->key.objectid); btrfs_info(cache->fs_info, "sinfo_used=%llu bg_num_bytes=%llu min_allocable=%llu", sinfo_used, num_bytes, min_allocable_bytes); btrfs_dump_space_info(cache->fs_info, cache->space_info, 0, 0); } return ret; } int btrfs_inc_block_group_ro(struct btrfs_block_group_cache *cache) { struct btrfs_fs_info *fs_info = cache->fs_info; struct btrfs_trans_handle *trans; u64 alloc_flags; int ret; again: trans = btrfs_join_transaction(fs_info->extent_root); if (IS_ERR(trans)) return PTR_ERR(trans); /* * we're not allowed to set block groups readonly after the dirty * block groups cache has started writing. If it already started, * back off and let this transaction commit */ mutex_lock(&fs_info->ro_block_group_mutex); if (test_bit(BTRFS_TRANS_DIRTY_BG_RUN, &trans->transaction->flags)) { u64 transid = trans->transid; mutex_unlock(&fs_info->ro_block_group_mutex); btrfs_end_transaction(trans); ret = btrfs_wait_for_commit(fs_info, transid); if (ret) return ret; goto again; } /* * if we are changing raid levels, try to allocate a corresponding * block group with the new raid level. */ alloc_flags = update_block_group_flags(fs_info, cache->flags); if (alloc_flags != cache->flags) { ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE); /* * ENOSPC is allowed here, we may have enough space * already allocated at the new raid level to * carry on */ if (ret == -ENOSPC) ret = 0; if (ret < 0) goto out; } ret = inc_block_group_ro(cache, 0); if (!ret) goto out; alloc_flags = get_alloc_profile(fs_info, cache->space_info->flags); ret = btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE); if (ret < 0) goto out; ret = inc_block_group_ro(cache, 0); out: if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { alloc_flags = update_block_group_flags(fs_info, cache->flags); mutex_lock(&fs_info->chunk_mutex); check_system_chunk(trans, alloc_flags); mutex_unlock(&fs_info->chunk_mutex); } mutex_unlock(&fs_info->ro_block_group_mutex); btrfs_end_transaction(trans); return ret; } int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, u64 type) { u64 alloc_flags = get_alloc_profile(trans->fs_info, type); return btrfs_chunk_alloc(trans, alloc_flags, CHUNK_ALLOC_FORCE); } /* * helper to account the unused space of all the readonly block group in the * space_info. takes mirrors into account. */ u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo) { struct btrfs_block_group_cache *block_group; u64 free_bytes = 0; int factor; /* It's df, we don't care if it's racy */ if (list_empty(&sinfo->ro_bgs)) return 0; spin_lock(&sinfo->lock); list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) { spin_lock(&block_group->lock); if (!block_group->ro) { spin_unlock(&block_group->lock); continue; } factor = btrfs_bg_type_to_factor(block_group->flags); free_bytes += (block_group->key.offset - btrfs_block_group_used(&block_group->item)) * factor; spin_unlock(&block_group->lock); } spin_unlock(&sinfo->lock); return free_bytes; } void btrfs_dec_block_group_ro(struct btrfs_block_group_cache *cache) { struct btrfs_space_info *sinfo = cache->space_info; u64 num_bytes; BUG_ON(!cache->ro); spin_lock(&sinfo->lock); spin_lock(&cache->lock); if (!--cache->ro) { num_bytes = cache->key.offset - cache->reserved - cache->pinned - cache->bytes_super - btrfs_block_group_used(&cache->item); sinfo->bytes_readonly -= num_bytes; list_del_init(&cache->ro_list); } spin_unlock(&cache->lock); spin_unlock(&sinfo->lock); } static int find_first_block_group(struct btrfs_fs_info *fs_info, struct btrfs_path *path, struct btrfs_key *key) { struct btrfs_root *root = fs_info->extent_root; int ret = 0; struct btrfs_key found_key; struct extent_buffer *leaf; struct btrfs_block_group_item bg; u64 flags; 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) { struct extent_map_tree *em_tree; struct extent_map *em; em_tree = &root->fs_info->mapping_tree; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, found_key.objectid, found_key.offset); read_unlock(&em_tree->lock); if (!em) { btrfs_err(fs_info, "logical %llu len %llu found bg but no related chunk", found_key.objectid, found_key.offset); ret = -ENOENT; } else if (em->start != found_key.objectid || em->len != found_key.offset) { btrfs_err(fs_info, "block group %llu len %llu mismatch with chunk %llu len %llu", found_key.objectid, found_key.offset, em->start, em->len); ret = -EUCLEAN; } else { read_extent_buffer(leaf, &bg, btrfs_item_ptr_offset(leaf, slot), sizeof(bg)); flags = btrfs_block_group_flags(&bg) & BTRFS_BLOCK_GROUP_TYPE_MASK; if (flags != (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { btrfs_err(fs_info, "block group %llu len %llu type flags 0x%llx mismatch with chunk type flags 0x%llx", found_key.objectid, found_key.offset, flags, (BTRFS_BLOCK_GROUP_TYPE_MASK & em->map_lookup->type)); ret = -EUCLEAN; } else { ret = 0; } } free_extent_map(em); goto out; } path->slots[0]++; } out: return ret; } void btrfs_put_block_group_cache(struct btrfs_fs_info *info) { struct btrfs_block_group_cache *block_group; u64 last = 0; while (1) { struct inode *inode; block_group = btrfs_lookup_first_block_group(info, last); while (block_group) { btrfs_wait_block_group_cache_done(block_group); spin_lock(&block_group->lock); if (block_group->iref) break; spin_unlock(&block_group->lock); block_group = btrfs_next_block_group(block_group); } if (!block_group) { if (last == 0) break; last = 0; continue; } inode = block_group->inode; block_group->iref = 0; block_group->inode = NULL; spin_unlock(&block_group->lock); ASSERT(block_group->io_ctl.inode == NULL); iput(inode); last = block_group->key.objectid + block_group->key.offset; btrfs_put_block_group(block_group); } } /* * Must be called only after stopping all workers, since we could have block * group caching kthreads running, and therefore they could race with us if we * freed the block groups before stopping them. */ int btrfs_free_block_groups(struct btrfs_fs_info *info) { struct btrfs_block_group_cache *block_group; struct btrfs_space_info *space_info; struct btrfs_caching_control *caching_ctl; struct rb_node *n; down_write(&info->commit_root_sem); while (!list_empty(&info->caching_block_groups)) { caching_ctl = list_entry(info->caching_block_groups.next, struct btrfs_caching_control, list); list_del(&caching_ctl->list); btrfs_put_caching_control(caching_ctl); } up_write(&info->commit_root_sem); spin_lock(&info->unused_bgs_lock); while (!list_empty(&info->unused_bgs)) { block_group = list_first_entry(&info->unused_bgs, struct btrfs_block_group_cache, bg_list); list_del_init(&block_group->bg_list); btrfs_put_block_group(block_group); } spin_unlock(&info->unused_bgs_lock); spin_lock(&info->block_group_cache_lock); while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { block_group = rb_entry(n, struct btrfs_block_group_cache, cache_node); rb_erase(&block_group->cache_node, &info->block_group_cache_tree); RB_CLEAR_NODE(&block_group->cache_node); spin_unlock(&info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); list_del(&block_group->list); up_write(&block_group->space_info->groups_sem); /* * We haven't cached this block group, which means we could * possibly have excluded extents on this block group. */ if (block_group->cached == BTRFS_CACHE_NO || block_group->cached == BTRFS_CACHE_ERROR) btrfs_free_excluded_extents(block_group); btrfs_remove_free_space_cache(block_group); ASSERT(block_group->cached != BTRFS_CACHE_STARTED); ASSERT(list_empty(&block_group->dirty_list)); ASSERT(list_empty(&block_group->io_list)); ASSERT(list_empty(&block_group->bg_list)); ASSERT(atomic_read(&block_group->count) == 1); btrfs_put_block_group(block_group); spin_lock(&info->block_group_cache_lock); } spin_unlock(&info->block_group_cache_lock); /* now that all the block groups are freed, go through and * free all the space_info structs. This is only called during * the final stages of unmount, and so we know nobody is * using them. We call synchronize_rcu() once before we start, * just to be on the safe side. */ synchronize_rcu(); btrfs_release_global_block_rsv(info); while (!list_empty(&info->space_info)) { space_info = list_entry(info->space_info.next, struct btrfs_space_info, list); /* * Do not hide this behind enospc_debug, this is actually * important and indicates a real bug if this happens. */ if (WARN_ON(space_info->bytes_pinned > 0 || space_info->bytes_reserved > 0 || space_info->bytes_may_use > 0)) btrfs_dump_space_info(info, space_info, 0, 0); list_del(&space_info->list); btrfs_sysfs_remove_space_info(space_info); } return 0; } static void link_block_group(struct btrfs_block_group_cache *cache) { struct btrfs_space_info *space_info = cache->space_info; int index = btrfs_bg_flags_to_raid_index(cache->flags); bool first = false; down_write(&space_info->groups_sem); if (list_empty(&space_info->block_groups[index])) first = true; list_add_tail(&cache->list, &space_info->block_groups[index]); up_write(&space_info->groups_sem); if (first) btrfs_sysfs_add_block_group_type(cache); } static struct btrfs_block_group_cache * btrfs_create_block_group_cache(struct btrfs_fs_info *fs_info, u64 start, u64 size) { struct btrfs_block_group_cache *cache; cache = kzalloc(sizeof(*cache), GFP_NOFS); if (!cache) return NULL; cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl), GFP_NOFS); if (!cache->free_space_ctl) { kfree(cache); return NULL; } cache->key.objectid = start; cache->key.offset = size; cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; cache->fs_info = fs_info; cache->full_stripe_len = btrfs_full_stripe_len(fs_info, start); set_free_space_tree_thresholds(cache); atomic_set(&cache->count, 1); spin_lock_init(&cache->lock); init_rwsem(&cache->data_rwsem); INIT_LIST_HEAD(&cache->list); INIT_LIST_HEAD(&cache->cluster_list); INIT_LIST_HEAD(&cache->bg_list); INIT_LIST_HEAD(&cache->ro_list); INIT_LIST_HEAD(&cache->dirty_list); INIT_LIST_HEAD(&cache->io_list); btrfs_init_free_space_ctl(cache); atomic_set(&cache->trimming, 0); mutex_init(&cache->free_space_lock); btrfs_init_full_stripe_locks_tree(&cache->full_stripe_locks_root); return cache; } /* * Iterate all chunks and verify that each of them has the corresponding block * group */ static int check_chunk_block_group_mappings(struct btrfs_fs_info *fs_info) { struct extent_map_tree *map_tree = &fs_info->mapping_tree; struct extent_map *em; struct btrfs_block_group_cache *bg; u64 start = 0; int ret = 0; while (1) { read_lock(&map_tree->lock); /* * lookup_extent_mapping will return the first extent map * intersecting the range, so setting @len to 1 is enough to * get the first chunk. */ em = lookup_extent_mapping(map_tree, start, 1); read_unlock(&map_tree->lock); if (!em) break; bg = btrfs_lookup_block_group(fs_info, em->start); if (!bg) { btrfs_err(fs_info, "chunk start=%llu len=%llu doesn't have corresponding block group", em->start, em->len); ret = -EUCLEAN; free_extent_map(em); break; } if (bg->key.objectid != em->start || bg->key.offset != em->len || (bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK) != (em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK)) { btrfs_err(fs_info, "chunk start=%llu len=%llu flags=0x%llx doesn't match block group start=%llu len=%llu flags=0x%llx", em->start, em->len, em->map_lookup->type & BTRFS_BLOCK_GROUP_TYPE_MASK, bg->key.objectid, bg->key.offset, bg->flags & BTRFS_BLOCK_GROUP_TYPE_MASK); ret = -EUCLEAN; free_extent_map(em); btrfs_put_block_group(bg); break; } start = em->start + em->len; free_extent_map(em); btrfs_put_block_group(bg); } return ret; } int btrfs_read_block_groups(struct btrfs_fs_info *info) { struct btrfs_path *path; int ret; struct btrfs_block_group_cache *cache; struct btrfs_space_info *space_info; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf; int need_clear = 0; u64 cache_gen; u64 feature; int mixed; feature = btrfs_super_incompat_flags(info->super_copy); mixed = !!(feature & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS); key.objectid = 0; key.offset = 0; key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = READA_FORWARD; cache_gen = btrfs_super_cache_generation(info->super_copy); if (btrfs_test_opt(info, SPACE_CACHE) && btrfs_super_generation(info->super_copy) != cache_gen) need_clear = 1; if (btrfs_test_opt(info, CLEAR_CACHE)) need_clear = 1; while (1) { ret = find_first_block_group(info, path, &key); if (ret > 0) break; if (ret != 0) goto error; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); cache = btrfs_create_block_group_cache(info, found_key.objectid, found_key.offset); if (!cache) { ret = -ENOMEM; goto error; } if (need_clear) { /* * When we mount with old space cache, we need to * set BTRFS_DC_CLEAR and set dirty flag. * * a) Setting 'BTRFS_DC_CLEAR' makes sure that we * truncate the old free space cache inode and * setup a new one. * b) Setting 'dirty flag' makes sure that we flush * the new space cache info onto disk. */ if (btrfs_test_opt(info, SPACE_CACHE)) cache->disk_cache_state = BTRFS_DC_CLEAR; } read_extent_buffer(leaf, &cache->item, btrfs_item_ptr_offset(leaf, path->slots[0]), sizeof(cache->item)); cache->flags = btrfs_block_group_flags(&cache->item); if (!mixed && ((cache->flags & BTRFS_BLOCK_GROUP_METADATA) && (cache->flags & BTRFS_BLOCK_GROUP_DATA))) { btrfs_err(info, "bg %llu is a mixed block group but filesystem hasn't enabled mixed block groups", cache->key.objectid); ret = -EINVAL; goto error; } key.objectid = found_key.objectid + found_key.offset; btrfs_release_path(path); /* * We need to exclude the super stripes now so that the space * info has super bytes accounted for, otherwise we'll think * we have more space than we actually do. */ ret = exclude_super_stripes(cache); if (ret) { /* * We may have excluded something, so call this just in * case. */ btrfs_free_excluded_extents(cache); btrfs_put_block_group(cache); goto error; } /* * check for two cases, either we are full, and therefore * don't need to bother with the caching work since we won't * find any space, or we are empty, and we can just add all * the space in and be done with it. This saves us _a_lot_ of * time, particularly in the full case. */ if (found_key.offset == btrfs_block_group_used(&cache->item)) { cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; btrfs_free_excluded_extents(cache); } else if (btrfs_block_group_used(&cache->item) == 0) { cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; add_new_free_space(cache, found_key.objectid, found_key.objectid + found_key.offset); btrfs_free_excluded_extents(cache); } ret = btrfs_add_block_group_cache(info, cache); if (ret) { btrfs_remove_free_space_cache(cache); btrfs_put_block_group(cache); goto error; } trace_btrfs_add_block_group(info, cache, 0); btrfs_update_space_info(info, cache->flags, found_key.offset, btrfs_block_group_used(&cache->item), cache->bytes_super, &space_info); cache->space_info = space_info; link_block_group(cache); set_avail_alloc_bits(info, cache->flags); if (btrfs_chunk_readonly(info, cache->key.objectid)) { inc_block_group_ro(cache, 1); } else if (btrfs_block_group_used(&cache->item) == 0) { ASSERT(list_empty(&cache->bg_list)); btrfs_mark_bg_unused(cache); } } list_for_each_entry_rcu(space_info, &info->space_info, list) { if (!(get_alloc_profile(info, space_info->flags) & (BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_RAID1_MASK | BTRFS_BLOCK_GROUP_RAID56_MASK | BTRFS_BLOCK_GROUP_DUP))) continue; /* * avoid allocating from un-mirrored block group if there are * mirrored block groups. */ list_for_each_entry(cache, &space_info->block_groups[BTRFS_RAID_RAID0], list) inc_block_group_ro(cache, 1); list_for_each_entry(cache, &space_info->block_groups[BTRFS_RAID_SINGLE], list) inc_block_group_ro(cache, 1); } btrfs_init_global_block_rsv(info); ret = check_chunk_block_group_mappings(info); error: btrfs_free_path(path); return ret; } void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *block_group; struct btrfs_root *extent_root = fs_info->extent_root; struct btrfs_block_group_item item; struct btrfs_key key; int ret = 0; if (!trans->can_flush_pending_bgs) return; while (!list_empty(&trans->new_bgs)) { block_group = list_first_entry(&trans->new_bgs, struct btrfs_block_group_cache, bg_list); if (ret) goto next; spin_lock(&block_group->lock); memcpy(&item, &block_group->item, sizeof(item)); memcpy(&key, &block_group->key, sizeof(key)); spin_unlock(&block_group->lock); ret = btrfs_insert_item(trans, extent_root, &key, &item, sizeof(item)); if (ret) btrfs_abort_transaction(trans, ret); ret = btrfs_finish_chunk_alloc(trans, key.objectid, key.offset); if (ret) btrfs_abort_transaction(trans, ret); add_block_group_free_space(trans, block_group); /* already aborted the transaction if it failed. */ next: btrfs_delayed_refs_rsv_release(fs_info, 1); list_del_init(&block_group->bg_list); } btrfs_trans_release_chunk_metadata(trans); } int btrfs_make_block_group(struct btrfs_trans_handle *trans, u64 bytes_used, u64 type, u64 chunk_offset, u64 size) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_block_group_cache *cache; int ret; btrfs_set_log_full_commit(trans); cache = btrfs_create_block_group_cache(fs_info, chunk_offset, size); if (!cache) return -ENOMEM; btrfs_set_block_group_used(&cache->item, bytes_used); btrfs_set_block_group_chunk_objectid(&cache->item, BTRFS_FIRST_CHUNK_TREE_OBJECTID); btrfs_set_block_group_flags(&cache->item, type); cache->flags = type; cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; cache->needs_free_space = 1; ret = exclude_super_stripes(cache); if (ret) { /* * We may have excluded something, so call this just in * case. */ btrfs_free_excluded_extents(cache); btrfs_put_block_group(cache); return ret; } add_new_free_space(cache, chunk_offset, chunk_offset + size); btrfs_free_excluded_extents(cache); #ifdef CONFIG_BTRFS_DEBUG if (btrfs_should_fragment_free_space(cache)) { u64 new_bytes_used = size - bytes_used; bytes_used += new_bytes_used >> 1; btrfs_fragment_free_space(cache); } #endif /* * Ensure the corresponding space_info object is created and * assigned to our block group. We want our bg to be added to the rbtree * with its ->space_info set. */ cache->space_info = btrfs_find_space_info(fs_info, cache->flags); ASSERT(cache->space_info); ret = btrfs_add_block_group_cache(fs_info, cache); if (ret) { btrfs_remove_free_space_cache(cache); btrfs_put_block_group(cache); return ret; } /* * Now that our block group has its ->space_info set and is inserted in * the rbtree, update the space info's counters. */ trace_btrfs_add_block_group(fs_info, cache, 1); btrfs_update_space_info(fs_info, cache->flags, size, bytes_used, cache->bytes_super, &cache->space_info); btrfs_update_global_block_rsv(fs_info); link_block_group(cache); list_add_tail(&cache->bg_list, &trans->new_bgs); trans->delayed_ref_updates++; btrfs_update_delayed_refs_rsv(trans); set_avail_alloc_bits(fs_info, type); return 0; } static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) { u64 extra_flags = chunk_to_extended(flags) & BTRFS_EXTENDED_PROFILE_MASK; write_seqlock(&fs_info->profiles_lock); if (flags & BTRFS_BLOCK_GROUP_DATA) fs_info->avail_data_alloc_bits &= ~extra_flags; if (flags & BTRFS_BLOCK_GROUP_METADATA) fs_info->avail_metadata_alloc_bits &= ~extra_flags; if (flags & BTRFS_BLOCK_GROUP_SYSTEM) fs_info->avail_system_alloc_bits &= ~extra_flags; write_sequnlock(&fs_info->profiles_lock); } /* * Clear incompat bits for the following feature(s): * * - RAID56 - in case there's neither RAID5 nor RAID6 profile block group * in the whole filesystem */ static void clear_incompat_bg_bits(struct btrfs_fs_info *fs_info, u64 flags) { if (flags & BTRFS_BLOCK_GROUP_RAID56_MASK) { struct list_head *head = &fs_info->space_info; struct btrfs_space_info *sinfo; list_for_each_entry_rcu(sinfo, head, list) { bool found = false; down_read(&sinfo->groups_sem); if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID5])) found = true; if (!list_empty(&sinfo->block_groups[BTRFS_RAID_RAID6])) found = true; up_read(&sinfo->groups_sem); if (found) return; } btrfs_clear_fs_incompat(fs_info, RAID56); } } int btrfs_remove_block_group(struct btrfs_trans_handle *trans, u64 group_start, struct extent_map *em) { struct btrfs_fs_info *fs_info = trans->fs_info; struct btrfs_root *root = fs_info->extent_root; struct btrfs_path *path; struct btrfs_block_group_cache *block_group; struct btrfs_free_cluster *cluster; struct btrfs_root *tree_root = fs_info->tree_root; struct btrfs_key key; struct inode *inode; struct kobject *kobj = NULL; int ret; int index; int factor; struct btrfs_caching_control *caching_ctl = NULL; bool remove_em; bool remove_rsv = false; block_group = btrfs_lookup_block_group(fs_info, group_start); BUG_ON(!block_group); BUG_ON(!block_group->ro); trace_btrfs_remove_block_group(block_group); /* * Free the reserved super bytes from this block group before * remove it. */ btrfs_free_excluded_extents(block_group); btrfs_free_ref_tree_range(fs_info, block_group->key.objectid, block_group->key.offset); memcpy(&key, &block_group->key, sizeof(key)); index = btrfs_bg_flags_to_raid_index(block_group->flags); factor = btrfs_bg_type_to_factor(block_group->flags); /* make sure this block group isn't part of an allocation cluster */ cluster = &fs_info->data_alloc_cluster; spin_lock(&cluster->refill_lock); btrfs_return_cluster_to_free_space(block_group, cluster); spin_unlock(&cluster->refill_lock); /* * make sure this block group isn't part of a metadata * allocation cluster */ cluster = &fs_info->meta_alloc_cluster; spin_lock(&cluster->refill_lock); btrfs_return_cluster_to_free_space(block_group, cluster); spin_unlock(&cluster->refill_lock); path = btrfs_alloc_path(); if (!path) { ret = -ENOMEM; goto out; } /* * get the inode first so any iput calls done for the io_list * aren't the final iput (no unlinks allowed now) */ inode = lookup_free_space_inode(block_group, path); mutex_lock(&trans->transaction->cache_write_mutex); /* * Make sure our free space cache IO is done before removing the * free space inode */ spin_lock(&trans->transaction->dirty_bgs_lock); if (!list_empty(&block_group->io_list)) { list_del_init(&block_group->io_list); WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode); spin_unlock(&trans->transaction->dirty_bgs_lock); btrfs_wait_cache_io(trans, block_group, path); btrfs_put_block_group(block_group); spin_lock(&trans->transaction->dirty_bgs_lock); } if (!list_empty(&block_group->dirty_list)) { list_del_init(&block_group->dirty_list); remove_rsv = true; btrfs_put_block_group(block_group); } spin_unlock(&trans->transaction->dirty_bgs_lock); mutex_unlock(&trans->transaction->cache_write_mutex); if (!IS_ERR(inode)) { ret = btrfs_orphan_add(trans, BTRFS_I(inode)); if (ret) { btrfs_add_delayed_iput(inode); goto out; } clear_nlink(inode); /* One for the block groups ref */ spin_lock(&block_group->lock); if (block_group->iref) { block_group->iref = 0; block_group->inode = NULL; spin_unlock(&block_group->lock); iput(inode); } else { spin_unlock(&block_group->lock); } /* One for our lookup ref */ btrfs_add_delayed_iput(inode); } key.objectid = BTRFS_FREE_SPACE_OBJECTID; key.offset = block_group->key.objectid; key.type = 0; ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); if (ret < 0) goto out; if (ret > 0) btrfs_release_path(path); if (ret == 0) { ret = btrfs_del_item(trans, tree_root, path); if (ret) goto out; btrfs_release_path(path); } spin_lock(&fs_info->block_group_cache_lock); rb_erase(&block_group->cache_node, &fs_info->block_group_cache_tree); RB_CLEAR_NODE(&block_group->cache_node); if (fs_info->first_logical_byte == block_group->key.objectid) fs_info->first_logical_byte = (u64)-1; spin_unlock(&fs_info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); /* * we must use list_del_init so people can check to see if they * are still on the list after taking the semaphore */ list_del_init(&block_group->list); if (list_empty(&block_group->space_info->block_groups[index])) { kobj = block_group->space_info->block_group_kobjs[index]; block_group->space_info->block_group_kobjs[index] = NULL; clear_avail_alloc_bits(fs_info, block_group->flags); } up_write(&block_group->space_info->groups_sem); clear_incompat_bg_bits(fs_info, block_group->flags); if (kobj) { kobject_del(kobj); kobject_put(kobj); } if (block_group->has_caching_ctl) caching_ctl = btrfs_get_caching_control(block_group); if (block_group->cached == BTRFS_CACHE_STARTED) btrfs_wait_block_group_cache_done(block_group); if (block_group->has_caching_ctl) { down_write(&fs_info->commit_root_sem); if (!caching_ctl) { struct btrfs_caching_control *ctl; list_for_each_entry(ctl, &fs_info->caching_block_groups, list) if (ctl->block_group == block_group) { caching_ctl = ctl; refcount_inc(&caching_ctl->count); break; } } if (caching_ctl) list_del_init(&caching_ctl->list); up_write(&fs_info->commit_root_sem); if (caching_ctl) { /* Once for the caching bgs list and once for us. */ btrfs_put_caching_control(caching_ctl); btrfs_put_caching_control(caching_ctl); } } spin_lock(&trans->transaction->dirty_bgs_lock); WARN_ON(!list_empty(&block_group->dirty_list)); WARN_ON(!list_empty(&block_group->io_list)); spin_unlock(&trans->transaction->dirty_bgs_lock); btrfs_remove_free_space_cache(block_group); spin_lock(&block_group->space_info->lock); list_del_init(&block_group->ro_list); if (btrfs_test_opt(fs_info, ENOSPC_DEBUG)) { WARN_ON(block_group->space_info->total_bytes < block_group->key.offset); WARN_ON(block_group->space_info->bytes_readonly < block_group->key.offset); WARN_ON(block_group->space_info->disk_total < block_group->key.offset * factor); } block_group->space_info->total_bytes -= block_group->key.offset; block_group->space_info->bytes_readonly -= block_group->key.offset; block_group->space_info->disk_total -= block_group->key.offset * factor; spin_unlock(&block_group->space_info->lock); memcpy(&key, &block_group->key, sizeof(key)); mutex_lock(&fs_info->chunk_mutex); spin_lock(&block_group->lock); block_group->removed = 1; /* * At this point trimming can't start on this block group, because we * removed the block group from the tree fs_info->block_group_cache_tree * so no one can't find it anymore and even if someone already got this * block group before we removed it from the rbtree, they have already * incremented block_group->trimming - if they didn't, they won't find * any free space entries because we already removed them all when we * called btrfs_remove_free_space_cache(). * * And we must not remove the extent map from the fs_info->mapping_tree * to prevent the same logical address range and physical device space * ranges from being reused for a new block group. This is because our * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is * completely transactionless, so while it is trimming a range the * currently running transaction might finish and a new one start, * allowing for new block groups to be created that can reuse the same * physical device locations unless we take this special care. * * There may also be an implicit trim operation if the file system * is mounted with -odiscard. The same protections must remain * in place until the extents have been discarded completely when * the transaction commit has completed. */ remove_em = (atomic_read(&block_group->trimming) == 0); spin_unlock(&block_group->lock); mutex_unlock(&fs_info->chunk_mutex); ret = remove_block_group_free_space(trans, block_group); if (ret) goto out; btrfs_put_block_group(block_group); btrfs_put_block_group(block_group); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -EIO; if (ret < 0) goto out; ret = btrfs_del_item(trans, root, path); if (ret) goto out; if (remove_em) { struct extent_map_tree *em_tree; em_tree = &fs_info->mapping_tree; write_lock(&em_tree->lock); remove_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); /* once for the tree */ free_extent_map(em); } out: if (remove_rsv) btrfs_delayed_refs_rsv_release(fs_info, 1); btrfs_free_path(path); return ret; } struct btrfs_trans_handle * btrfs_start_trans_remove_block_group(struct btrfs_fs_info *fs_info, const u64 chunk_offset) { struct extent_map_tree *em_tree = &fs_info->mapping_tree; struct extent_map *em; struct map_lookup *map; unsigned int num_items; read_lock(&em_tree->lock); em = lookup_extent_mapping(em_tree, chunk_offset, 1); read_unlock(&em_tree->lock); ASSERT(em && em->start == chunk_offset); /* * We need to reserve 3 + N units from the metadata space info in order * to remove a block group (done at btrfs_remove_chunk() and at * btrfs_remove_block_group()), which are used for: * * 1 unit for adding the free space inode's orphan (located in the tree * of tree roots). * 1 unit for deleting the block group item (located in the extent * tree). * 1 unit for deleting the free space item (located in tree of tree * roots). * N units for deleting N device extent items corresponding to each * stripe (located in the device tree). * * In order to remove a block group we also need to reserve units in the * system space info in order to update the chunk tree (update one or * more device items and remove one chunk item), but this is done at * btrfs_remove_chunk() through a call to check_system_chunk(). */ map = em->map_lookup; num_items = 3 + map->num_stripes; free_extent_map(em); return btrfs_start_transaction_fallback_global_rsv(fs_info->extent_root, num_items, 1); } /* * Process the unused_bgs list and remove any that don't have any allocated * space inside of them. */ void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) { struct btrfs_block_group_cache *block_group; struct btrfs_space_info *space_info; struct btrfs_trans_handle *trans; int ret = 0; if (!test_bit(BTRFS_FS_OPEN, &fs_info->flags)) return; spin_lock(&fs_info->unused_bgs_lock); while (!list_empty(&fs_info->unused_bgs)) { u64 start, end; int trimming; block_group = list_first_entry(&fs_info->unused_bgs, struct btrfs_block_group_cache, bg_list); list_del_init(&block_group->bg_list); space_info = block_group->space_info; if (ret || btrfs_mixed_space_info(space_info)) { btrfs_put_block_group(block_group); continue; } spin_unlock(&fs_info->unused_bgs_lock); mutex_lock(&fs_info->delete_unused_bgs_mutex); /* Don't want to race with allocators so take the groups_sem */ down_write(&space_info->groups_sem); spin_lock(&block_group->lock); if (block_group->reserved || block_group->pinned || btrfs_block_group_used(&block_group->item) || block_group->ro || list_is_singular(&block_group->list)) { /* * We want to bail if we made new allocations or have * outstanding allocations in this block group. We do * the ro check in case balance is currently acting on * this block group. */ trace_btrfs_skip_unused_block_group(block_group); spin_unlock(&block_group->lock); up_write(&space_info->groups_sem); goto next; } spin_unlock(&block_group->lock); /* We don't want to force the issue, only flip if it's ok. */ ret = inc_block_group_ro(block_group, 0); up_write(&space_info->groups_sem); if (ret < 0) { ret = 0; goto next; } /* * Want to do this before we do anything else so we can recover * properly if we fail to join the transaction. */ trans = btrfs_start_trans_remove_block_group(fs_info, block_group->key.objectid); if (IS_ERR(trans)) { btrfs_dec_block_group_ro(block_group); ret = PTR_ERR(trans); goto next; } /* * We could have pending pinned extents for this block group, * just delete them, we don't care about them anymore. */ start = block_group->key.objectid; end = start + block_group->key.offset - 1; /* * Hold the unused_bg_unpin_mutex lock to avoid racing with * btrfs_finish_extent_commit(). If we are at transaction N, * another task might be running finish_extent_commit() for the * previous transaction N - 1, and have seen a range belonging * to the block group in freed_extents[] before we were able to * clear the whole block group range from freed_extents[]. This * means that task can lookup for the block group after we * unpinned it from freed_extents[] and removed it, leading to * a BUG_ON() at btrfs_unpin_extent_range(). */ mutex_lock(&fs_info->unused_bg_unpin_mutex); ret = clear_extent_bits(&fs_info->freed_extents[0], start, end, EXTENT_DIRTY); if (ret) { mutex_unlock(&fs_info->unused_bg_unpin_mutex); btrfs_dec_block_group_ro(block_group); goto end_trans; } ret = clear_extent_bits(&fs_info->freed_extents[1], start, end, EXTENT_DIRTY); if (ret) { mutex_unlock(&fs_info->unused_bg_unpin_mutex); btrfs_dec_block_group_ro(block_group); goto end_trans; } mutex_unlock(&fs_info->unused_bg_unpin_mutex); /* Reset pinned so btrfs_put_block_group doesn't complain */ spin_lock(&space_info->lock); spin_lock(&block_group->lock); btrfs_space_info_update_bytes_pinned(fs_info, space_info, -block_group->pinned); space_info->bytes_readonly += block_group->pinned; percpu_counter_add_batch(&space_info->total_bytes_pinned, -block_group->pinned, BTRFS_TOTAL_BYTES_PINNED_BATCH); block_group->pinned = 0; spin_unlock(&block_group->lock); spin_unlock(&space_info->lock); /* DISCARD can flip during remount */ trimming = btrfs_test_opt(fs_info, DISCARD); /* Implicit trim during transaction commit. */ if (trimming) btrfs_get_block_group_trimming(block_group); /* * Btrfs_remove_chunk will abort the transaction if things go * horribly wrong. */ ret = btrfs_remove_chunk(trans, block_group->key.objectid); if (ret) { if (trimming) btrfs_put_block_group_trimming(block_group); goto end_trans; } /* * If we're not mounted with -odiscard, we can just forget * about this block group. Otherwise we'll need to wait * until transaction commit to do the actual discard. */ if (trimming) { spin_lock(&fs_info->unused_bgs_lock); /* * A concurrent scrub might have added us to the list * fs_info->unused_bgs, so use a list_move operation * to add the block group to the deleted_bgs list. */ list_move(&block_group->bg_list, &trans->transaction->deleted_bgs); spin_unlock(&fs_info->unused_bgs_lock); btrfs_get_block_group(block_group); } end_trans: btrfs_end_transaction(trans); next: mutex_unlock(&fs_info->delete_unused_bgs_mutex); btrfs_put_block_group(block_group); spin_lock(&fs_info->unused_bgs_lock); } spin_unlock(&fs_info->unused_bgs_lock); } int btrfs_error_unpin_extent_range(struct btrfs_fs_info *fs_info, u64 start, u64 end) { return unpin_extent_range(fs_info, start, end, false); } /* * It used to be that old block groups would be left around forever. * Iterating over them would be enough to trim unused space. Since we * now automatically remove them, we also need to iterate over unallocated * space. * * We don't want a transaction for this since the discard may take a * substantial amount of time. We don't require that a transaction be * running, but we do need to take a running transaction into account * to ensure that we're not discarding chunks that were released or * allocated in the current transaction. * * Holding the chunks lock will prevent other threads from allocating * or releasing chunks, but it won't prevent a running transaction * from committing and releasing the memory that the pending chunks * list head uses. For that, we need to take a reference to the * transaction and hold the commit root sem. We only need to hold * it while performing the free space search since we have already * held back allocations. */ static int btrfs_trim_free_extents(struct btrfs_device *device, u64 *trimmed) { u64 start = SZ_1M, len = 0, end = 0; int ret; *trimmed = 0; /* Discard not supported = nothing to do. */ if (!blk_queue_discard(bdev_get_queue(device->bdev))) return 0; /* Not writable = nothing to do. */ if (!test_bit(BTRFS_DEV_STATE_WRITEABLE, &device->dev_state)) return 0; /* No free space = nothing to do. */ if (device->total_bytes <= device->bytes_used) return 0; ret = 0; while (1) { struct btrfs_fs_info *fs_info = device->fs_info; u64 bytes; ret = mutex_lock_interruptible(&fs_info->chunk_mutex); if (ret) break; find_first_clear_extent_bit(&device->alloc_state, start, &start, &end, CHUNK_TRIMMED | CHUNK_ALLOCATED); /* Ensure we skip the reserved area in the first 1M */ start = max_t(u64, start, SZ_1M); /* * If find_first_clear_extent_bit find a range that spans the * end of the device it will set end to -1, in this case it's up * to the caller to trim the value to the size of the device. */ end = min(end, device->total_bytes - 1); len = end - start + 1; /* We didn't find any extents */ if (!len) { mutex_unlock(&fs_info->chunk_mutex); ret = 0; break; } ret = btrfs_issue_discard(device->bdev, start, len, &bytes); if (!ret) set_extent_bits(&device->alloc_state, start, start + bytes - 1, CHUNK_TRIMMED); mutex_unlock(&fs_info->chunk_mutex); if (ret) break; start += len; *trimmed += bytes; if (fatal_signal_pending(current)) { ret = -ERESTARTSYS; break; } cond_resched(); } return ret; } /* * Trim the whole filesystem by: * 1) trimming the free space in each block group * 2) trimming the unallocated space on each device * * This will also continue trimming even if a block group or device encounters * an error. The return value will be the last error, or 0 if nothing bad * happens. */ int btrfs_trim_fs(struct btrfs_fs_info *fs_info, struct fstrim_range *range) { struct btrfs_block_group_cache *cache = NULL; struct btrfs_device *device; struct list_head *devices; u64 group_trimmed; u64 range_end = U64_MAX; u64 start; u64 end; u64 trimmed = 0; u64 bg_failed = 0; u64 dev_failed = 0; int bg_ret = 0; int dev_ret = 0; int ret = 0; /* * Check range overflow if range->len is set. * The default range->len is U64_MAX. */ if (range->len != U64_MAX && check_add_overflow(range->start, range->len, &range_end)) return -EINVAL; cache = btrfs_lookup_first_block_group(fs_info, range->start); for (; cache; cache = btrfs_next_block_group(cache)) { if (cache->key.objectid >= range_end) { btrfs_put_block_group(cache); break; } start = max(range->start, cache->key.objectid); end = min(range_end, cache->key.objectid + cache->key.offset); if (end - start >= range->minlen) { if (!btrfs_block_group_cache_done(cache)) { ret = btrfs_cache_block_group(cache, 0); if (ret) { bg_failed++; bg_ret = ret; continue; } ret = btrfs_wait_block_group_cache_done(cache); if (ret) { bg_failed++; bg_ret = ret; continue; } } ret = btrfs_trim_block_group(cache, &group_trimmed, start, end, range->minlen); trimmed += group_trimmed; if (ret) { bg_failed++; bg_ret = ret; continue; } } } if (bg_failed) btrfs_warn(fs_info, "failed to trim %llu block group(s), last error %d", bg_failed, bg_ret); mutex_lock(&fs_info->fs_devices->device_list_mutex); devices = &fs_info->fs_devices->devices; list_for_each_entry(device, devices, dev_list) { ret = btrfs_trim_free_extents(device, &group_trimmed); if (ret) { dev_failed++; dev_ret = ret; break; } trimmed += group_trimmed; } mutex_unlock(&fs_info->fs_devices->device_list_mutex); if (dev_failed) btrfs_warn(fs_info, "failed to trim %llu device(s), last error %d", dev_failed, dev_ret); range->len = trimmed; if (bg_ret) return bg_ret; return dev_ret; } /* * btrfs_{start,end}_write_no_snapshotting() are similar to * mnt_{want,drop}_write(), they are used to prevent some tasks from writing * data into the page cache through nocow before the subvolume is snapshoted, * but flush the data into disk after the snapshot creation, or to prevent * operations while snapshotting is ongoing and that cause the snapshot to be * inconsistent (writes followed by expanding truncates for example). */ void btrfs_end_write_no_snapshotting(struct btrfs_root *root) { percpu_counter_dec(&root->subv_writers->counter); cond_wake_up(&root->subv_writers->wait); } int btrfs_start_write_no_snapshotting(struct btrfs_root *root) { if (atomic_read(&root->will_be_snapshotted)) return 0; percpu_counter_inc(&root->subv_writers->counter); /* * Make sure counter is updated before we check for snapshot creation. */ smp_mb(); if (atomic_read(&root->will_be_snapshotted)) { btrfs_end_write_no_snapshotting(root); return 0; } return 1; } void btrfs_wait_for_snapshot_creation(struct btrfs_root *root) { while (true) { int ret; ret = btrfs_start_write_no_snapshotting(root); if (ret) break; wait_var_event(&root->will_be_snapshotted, !atomic_read(&root->will_be_snapshotted)); } } void btrfs_mark_bg_unused(struct btrfs_block_group_cache *bg) { struct btrfs_fs_info *fs_info = bg->fs_info; spin_lock(&fs_info->unused_bgs_lock); if (list_empty(&bg->bg_list)) { btrfs_get_block_group(bg); trace_btrfs_add_unused_block_group(bg); list_add_tail(&bg->bg_list, &fs_info->unused_bgs); } spin_unlock(&fs_info->unused_bgs_lock); }