/* * Copyright (C) 2007 Oracle. All rights reserved. * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public * License v2 as published by the Free Software Foundation. * * This program is distributed in the hope that it will be useful, * but WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public * License along with this program; if not, write to the * Free Software Foundation, Inc., 59 Temple Place - Suite 330, * Boston, MA 021110-1307, USA. */ #include #include #include #include #include #include #include #include "compat.h" #include "hash.h" #include "ctree.h" #include "disk-io.h" #include "print-tree.h" #include "transaction.h" #include "volumes.h" #include "locking.h" #include "free-space-cache.h" static int update_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, int alloc, int mark_free); static int update_reserved_extents(struct btrfs_block_group_cache *cache, u64 num_bytes, int reserve); static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner_objectid, u64 owner_offset, int refs_to_drop, struct btrfs_delayed_extent_op *extra_op); static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, struct extent_buffer *leaf, struct btrfs_extent_item *ei); static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 parent, u64 root_objectid, u64 flags, u64 owner, u64 offset, struct btrfs_key *ins, int ref_mod); static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 parent, u64 root_objectid, u64 flags, struct btrfs_disk_key *key, int level, struct btrfs_key *ins); static int do_chunk_alloc(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, u64 alloc_bytes, u64 flags, int force); static int pin_down_bytes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 num_bytes, int is_data, int reserved, struct extent_buffer **must_clean); static int find_next_key(struct btrfs_path *path, int level, struct btrfs_key *key); static void dump_space_info(struct btrfs_space_info *info, u64 bytes, int dump_block_groups); static noinline int block_group_cache_done(struct btrfs_block_group_cache *cache) { smp_mb(); return cache->cached == BTRFS_CACHE_FINISHED; } static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) { return (cache->flags & bits) == bits; } void btrfs_get_block_group(struct btrfs_block_group_cache *cache) { atomic_inc(&cache->count); } void btrfs_put_block_group(struct btrfs_block_group_cache *cache) { if (atomic_dec_and_test(&cache->count)) kfree(cache); } /* * this adds the block group to the fs_info rb tree for the block group * cache */ static int btrfs_add_block_group_cache(struct btrfs_fs_info *info, struct btrfs_block_group_cache *block_group) { struct rb_node **p; struct rb_node *parent = NULL; struct btrfs_block_group_cache *cache; spin_lock(&info->block_group_cache_lock); p = &info->block_group_cache_tree.rb_node; while (*p) { parent = *p; cache = rb_entry(parent, struct btrfs_block_group_cache, cache_node); if (block_group->key.objectid < cache->key.objectid) { p = &(*p)->rb_left; } else if (block_group->key.objectid > cache->key.objectid) { p = &(*p)->rb_right; } else { spin_unlock(&info->block_group_cache_lock); return -EEXIST; } } rb_link_node(&block_group->cache_node, parent, p); rb_insert_color(&block_group->cache_node, &info->block_group_cache_tree); spin_unlock(&info->block_group_cache_lock); return 0; } /* * This will return the block group at or after bytenr if contains is 0, else * it will return the block group that contains the bytenr */ static struct btrfs_block_group_cache * block_group_cache_tree_search(struct btrfs_fs_info *info, u64 bytenr, int contains) { struct btrfs_block_group_cache *cache, *ret = NULL; struct rb_node *n; u64 end, start; spin_lock(&info->block_group_cache_lock); n = info->block_group_cache_tree.rb_node; while (n) { cache = rb_entry(n, struct btrfs_block_group_cache, cache_node); end = cache->key.objectid + cache->key.offset - 1; start = cache->key.objectid; if (bytenr < start) { if (!contains && (!ret || start < ret->key.objectid)) ret = cache; n = n->rb_left; } else if (bytenr > start) { if (contains && bytenr <= end) { ret = cache; break; } n = n->rb_right; } else { ret = cache; break; } } if (ret) btrfs_get_block_group(ret); spin_unlock(&info->block_group_cache_lock); return ret; } static int add_excluded_extent(struct btrfs_root *root, u64 start, u64 num_bytes) { u64 end = start + num_bytes - 1; set_extent_bits(&root->fs_info->freed_extents[0], start, end, EXTENT_UPTODATE, GFP_NOFS); set_extent_bits(&root->fs_info->freed_extents[1], start, end, EXTENT_UPTODATE, GFP_NOFS); return 0; } static void free_excluded_extents(struct btrfs_root *root, struct btrfs_block_group_cache *cache) { u64 start, end; start = cache->key.objectid; end = start + cache->key.offset - 1; clear_extent_bits(&root->fs_info->freed_extents[0], start, end, EXTENT_UPTODATE, GFP_NOFS); clear_extent_bits(&root->fs_info->freed_extents[1], start, end, EXTENT_UPTODATE, GFP_NOFS); } static int exclude_super_stripes(struct btrfs_root *root, struct btrfs_block_group_cache *cache) { u64 bytenr; u64 *logical; int stripe_len; int i, nr, ret; if (cache->key.objectid < BTRFS_SUPER_INFO_OFFSET) { stripe_len = BTRFS_SUPER_INFO_OFFSET - cache->key.objectid; cache->bytes_super += stripe_len; ret = add_excluded_extent(root, cache->key.objectid, stripe_len); BUG_ON(ret); } for (i = 0; i < BTRFS_SUPER_MIRROR_MAX; i++) { bytenr = btrfs_sb_offset(i); ret = btrfs_rmap_block(&root->fs_info->mapping_tree, cache->key.objectid, bytenr, 0, &logical, &nr, &stripe_len); BUG_ON(ret); while (nr--) { cache->bytes_super += stripe_len; ret = add_excluded_extent(root, logical[nr], stripe_len); BUG_ON(ret); } kfree(logical); } return 0; } static struct btrfs_caching_control * get_caching_control(struct btrfs_block_group_cache *cache) { struct btrfs_caching_control *ctl; spin_lock(&cache->lock); if (cache->cached != BTRFS_CACHE_STARTED) { spin_unlock(&cache->lock); return NULL; } ctl = cache->caching_ctl; atomic_inc(&ctl->count); spin_unlock(&cache->lock); return ctl; } static void put_caching_control(struct btrfs_caching_control *ctl) { if (atomic_dec_and_test(&ctl->count)) kfree(ctl); } /* * this is only called by cache_block_group, since we could have freed extents * we need to check the pinned_extents for any extents that can't be used yet * since their free space will be released as soon as the transaction commits. */ static u64 add_new_free_space(struct btrfs_block_group_cache *block_group, struct btrfs_fs_info *info, u64 start, u64 end) { u64 extent_start, extent_end, size, total_added = 0; int ret; while (start < end) { ret = find_first_extent_bit(info->pinned_extents, start, &extent_start, &extent_end, EXTENT_DIRTY | EXTENT_UPTODATE); 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); 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); } return total_added; } static int caching_kthread(void *data) { struct btrfs_block_group_cache *block_group = data; struct btrfs_fs_info *fs_info = block_group->fs_info; struct btrfs_caching_control *caching_ctl = block_group->caching_ctl; 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 = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; exclude_super_stripes(extent_root, block_group); spin_lock(&block_group->space_info->lock); block_group->space_info->bytes_super += block_group->bytes_super; spin_unlock(&block_group->space_info->lock); last = max_t(u64, block_group->key.objectid, BTRFS_SUPER_INFO_OFFSET); /* * We don't want to deadlock with somebody trying to allocate a new * extent for the extent root while also trying to search the extent * root to add free space. So we skip locking and search the commit * root, since its read-only */ path->skip_locking = 1; path->search_commit_root = 1; path->reada = 2; key.objectid = last; key.offset = 0; key.type = BTRFS_EXTENT_ITEM_KEY; again: mutex_lock(&caching_ctl->mutex); /* need to make sure the commit_root doesn't disappear */ down_read(&fs_info->extent_commit_sem); ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto err; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); while (1) { smp_mb(); if (fs_info->closing > 1) { last = (u64)-1; break; } if (path->slots[0] < nritems) { btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); } else { ret = find_next_key(path, 0, &key); if (ret) break; caching_ctl->progress = last; btrfs_release_path(extent_root, path); up_read(&fs_info->extent_commit_sem); mutex_unlock(&caching_ctl->mutex); if (btrfs_transaction_in_commit(fs_info)) schedule_timeout(1); else cond_resched(); goto again; } 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) { total_found += add_new_free_space(block_group, fs_info, last, key.objectid); last = key.objectid + key.offset; if (total_found > (1024 * 1024 * 2)) { total_found = 0; wake_up(&caching_ctl->wait); } } path->slots[0]++; } ret = 0; total_found += add_new_free_space(block_group, fs_info, last, block_group->key.objectid + block_group->key.offset); caching_ctl->progress = (u64)-1; spin_lock(&block_group->lock); block_group->caching_ctl = NULL; block_group->cached = BTRFS_CACHE_FINISHED; spin_unlock(&block_group->lock); err: btrfs_free_path(path); up_read(&fs_info->extent_commit_sem); free_excluded_extents(extent_root, block_group); mutex_unlock(&caching_ctl->mutex); wake_up(&caching_ctl->wait); put_caching_control(caching_ctl); atomic_dec(&block_group->space_info->caching_threads); btrfs_put_block_group(block_group); return 0; } static int cache_block_group(struct btrfs_block_group_cache *cache) { struct btrfs_fs_info *fs_info = cache->fs_info; struct btrfs_caching_control *caching_ctl; struct task_struct *tsk; int ret = 0; smp_mb(); if (cache->cached != BTRFS_CACHE_NO) return 0; caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_KERNEL); BUG_ON(!caching_ctl); 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; /* one for caching kthread, one for caching block group list */ atomic_set(&caching_ctl->count, 2); spin_lock(&cache->lock); if (cache->cached != BTRFS_CACHE_NO) { spin_unlock(&cache->lock); kfree(caching_ctl); return 0; } cache->caching_ctl = caching_ctl; cache->cached = BTRFS_CACHE_STARTED; spin_unlock(&cache->lock); down_write(&fs_info->extent_commit_sem); list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); up_write(&fs_info->extent_commit_sem); atomic_inc(&cache->space_info->caching_threads); btrfs_get_block_group(cache); tsk = kthread_run(caching_kthread, cache, "btrfs-cache-%llu\n", cache->key.objectid); if (IS_ERR(tsk)) { ret = PTR_ERR(tsk); printk(KERN_ERR "error running thread %d\n", ret); BUG(); } return ret; } /* * return the block group that starts at or after bytenr */ static struct btrfs_block_group_cache * btrfs_lookup_first_block_group(struct btrfs_fs_info *info, u64 bytenr) { struct btrfs_block_group_cache *cache; cache = block_group_cache_tree_search(info, bytenr, 0); return cache; } /* * return the block group that contains the given bytenr */ struct btrfs_block_group_cache *btrfs_lookup_block_group( struct btrfs_fs_info *info, u64 bytenr) { struct btrfs_block_group_cache *cache; cache = block_group_cache_tree_search(info, bytenr, 1); return cache; } static struct btrfs_space_info *__find_space_info(struct btrfs_fs_info *info, u64 flags) { struct list_head *head = &info->space_info; struct btrfs_space_info *found; rcu_read_lock(); list_for_each_entry_rcu(found, head, list) { if (found->flags == flags) { rcu_read_unlock(); return found; } } rcu_read_unlock(); return NULL; } /* * after adding space to the filesystem, we need to clear the full flags * on all the space infos. */ void btrfs_clear_space_info_full(struct btrfs_fs_info *info) { struct list_head *head = &info->space_info; struct btrfs_space_info *found; rcu_read_lock(); list_for_each_entry_rcu(found, head, list) found->full = 0; rcu_read_unlock(); } static u64 div_factor(u64 num, int factor) { if (factor == 10) return num; num *= factor; do_div(num, 10); return num; } u64 btrfs_find_block_group(struct btrfs_root *root, u64 search_start, u64 search_hint, int owner) { struct btrfs_block_group_cache *cache; u64 used; u64 last = max(search_hint, search_start); u64 group_start = 0; int full_search = 0; int factor = 9; int wrapped = 0; again: while (1) { cache = btrfs_lookup_first_block_group(root->fs_info, last); if (!cache) break; spin_lock(&cache->lock); last = cache->key.objectid + cache->key.offset; used = btrfs_block_group_used(&cache->item); if ((full_search || !cache->ro) && block_group_bits(cache, BTRFS_BLOCK_GROUP_METADATA)) { if (used + cache->pinned + cache->reserved < div_factor(cache->key.offset, factor)) { group_start = cache->key.objectid; spin_unlock(&cache->lock); btrfs_put_block_group(cache); goto found; } } spin_unlock(&cache->lock); btrfs_put_block_group(cache); cond_resched(); } if (!wrapped) { last = search_start; wrapped = 1; goto again; } if (!full_search && factor < 10) { last = search_start; full_search = 1; factor = 10; goto again; } found: return group_start; } /* simple helper to search for an existing extent at a given offset */ int btrfs_lookup_extent(struct btrfs_root *root, u64 start, u64 len) { int ret; struct btrfs_key key; struct btrfs_path *path; path = btrfs_alloc_path(); BUG_ON(!path); key.objectid = start; key.offset = len; btrfs_set_key_type(&key, BTRFS_EXTENT_ITEM_KEY); ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, 0, 0); btrfs_free_path(path); return ret; } /* * Back reference rules. Back refs have three main goals: * * 1) differentiate between all holders of references to an extent so that * when a reference is dropped we can make sure it was a valid reference * before freeing the extent. * * 2) Provide enough information to quickly find the holders of an extent * if we notice a given block is corrupted or bad. * * 3) Make it easy to migrate blocks for FS shrinking or storage pool * maintenance. This is actually the same as #2, but with a slightly * different use case. * * There are two kinds of back refs. The implicit back refs is optimized * for pointers in non-shared tree blocks. For a given pointer in a block, * back refs of this kind provide information about the block's owner tree * and the pointer's key. These information allow us to find the block by * b-tree searching. The full back refs is for pointers in tree blocks not * referenced by their owner trees. The location of tree block is recorded * in the back refs. Actually the full back refs is generic, and can be * used in all cases the implicit back refs is used. The major shortcoming * of the full back refs is its overhead. Every time a tree block gets * COWed, we have to update back refs entry for all pointers in it. * * For a newly allocated tree block, we use implicit back refs for * pointers in it. This means most tree related operations only involve * implicit back refs. For a tree block created in old transaction, the * only way to drop a reference to it is COW it. So we can detect the * event that tree block loses its owner tree's reference and do the * back refs conversion. * * When a tree block is COW'd through a tree, there are four cases: * * The reference count of the block is one and the tree is the block's * owner tree. Nothing to do in this case. * * The reference count of the block is one and the tree is not the * block's owner tree. In this case, full back refs is used for pointers * in the block. Remove these full back refs, add implicit back refs for * every pointers in the new block. * * The reference count of the block is greater than one and the tree is * the block's owner tree. In this case, implicit back refs is used for * pointers in the block. Add full back refs for every pointers in the * block, increase lower level extents' reference counts. The original * implicit back refs are entailed to the new block. * * The reference count of the block is greater than one and the tree is * not the block's owner tree. Add implicit back refs for every pointer in * the new block, increase lower level extents' reference count. * * Back Reference Key composing: * * The key objectid corresponds to the first byte in the extent, * The key type is used to differentiate between types of back refs. * There are different meanings of the key offset for different types * of back refs. * * File extents can be referenced by: * * - multiple snapshots, subvolumes, or different generations in one subvol * - different files inside a single subvolume * - different offsets inside a file (bookend extents in file.c) * * The extent ref structure for the implicit back refs has fields for: * * - Objectid of the subvolume root * - objectid of the file holding the reference * - original offset in the file * - how many bookend extents * * The key offset for the implicit back refs is hash of the first * three fields. * * The extent ref structure for the full back refs has field for: * * - number of pointers in the tree leaf * * The key offset for the implicit back refs is the first byte of * the tree leaf * * When a file extent is allocated, The implicit back refs is used. * the fields are filled in: * * (root_key.objectid, inode objectid, offset in file, 1) * * When a file extent is removed file truncation, we find the * corresponding implicit back refs and check the following fields: * * (btrfs_header_owner(leaf), inode objectid, offset in file) * * Btree extents can be referenced by: * * - Different subvolumes * * Both the implicit back refs and the full back refs for tree blocks * only consist of key. The key offset for the implicit back refs is * objectid of block's owner tree. The key offset for the full back refs * is the first byte of parent block. * * When implicit back refs is used, information about the lowest key and * level of the tree block are required. These information are stored in * tree block info structure. */ #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 static int convert_extent_item_v0(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 owner, u32 extra_size) { struct btrfs_extent_item *item; struct btrfs_extent_item_v0 *ei0; struct btrfs_extent_ref_v0 *ref0; struct btrfs_tree_block_info *bi; struct extent_buffer *leaf; struct btrfs_key key; struct btrfs_key found_key; u32 new_size = sizeof(*item); u64 refs; int ret; leaf = path->nodes[0]; BUG_ON(btrfs_item_size_nr(leaf, path->slots[0]) != sizeof(*ei0)); btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); ei0 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item_v0); refs = btrfs_extent_refs_v0(leaf, ei0); if (owner == (u64)-1) { while (1) { if (path->slots[0] >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret < 0) return ret; BUG_ON(ret > 0); leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); BUG_ON(key.objectid != found_key.objectid); if (found_key.type != BTRFS_EXTENT_REF_V0_KEY) { path->slots[0]++; continue; } ref0 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref_v0); owner = btrfs_ref_objectid_v0(leaf, ref0); break; } } btrfs_release_path(root, path); if (owner < BTRFS_FIRST_FREE_OBJECTID) new_size += sizeof(*bi); new_size -= sizeof(*ei0); ret = btrfs_search_slot(trans, root, &key, path, new_size + extra_size, 1); if (ret < 0) return ret; BUG_ON(ret); ret = btrfs_extend_item(trans, root, path, new_size); BUG_ON(ret); leaf = path->nodes[0]; item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); btrfs_set_extent_refs(leaf, item, refs); /* FIXME: get real generation */ btrfs_set_extent_generation(leaf, item, 0); if (owner < BTRFS_FIRST_FREE_OBJECTID) { btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_TREE_BLOCK | BTRFS_BLOCK_FLAG_FULL_BACKREF); bi = (struct btrfs_tree_block_info *)(item + 1); /* FIXME: get first key of the block */ memset_extent_buffer(leaf, 0, (unsigned long)bi, sizeof(*bi)); btrfs_set_tree_block_level(leaf, bi, (int)owner); } else { btrfs_set_extent_flags(leaf, item, BTRFS_EXTENT_FLAG_DATA); } btrfs_mark_buffer_dirty(leaf); return 0; } #endif static u64 hash_extent_data_ref(u64 root_objectid, u64 owner, u64 offset) { u32 high_crc = ~(u32)0; u32 low_crc = ~(u32)0; __le64 lenum; lenum = cpu_to_le64(root_objectid); high_crc = crc32c(high_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(owner); low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); lenum = cpu_to_le64(offset); low_crc = crc32c(low_crc, &lenum, sizeof(lenum)); return ((u64)high_crc << 31) ^ (u64)low_crc; } static u64 hash_extent_data_ref_item(struct extent_buffer *leaf, struct btrfs_extent_data_ref *ref) { return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref), btrfs_extent_data_ref_objectid(leaf, ref), btrfs_extent_data_ref_offset(leaf, ref)); } static int match_extent_data_ref(struct extent_buffer *leaf, struct btrfs_extent_data_ref *ref, u64 root_objectid, u64 owner, u64 offset) { if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid || btrfs_extent_data_ref_objectid(leaf, ref) != owner || btrfs_extent_data_ref_offset(leaf, ref) != offset) return 0; return 1; } static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset) { struct btrfs_key key; struct btrfs_extent_data_ref *ref; struct extent_buffer *leaf; u32 nritems; int ret; int recow; int err = -ENOENT; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_DATA_REF_KEY; key.offset = parent; } else { key.type = BTRFS_EXTENT_DATA_REF_KEY; key.offset = hash_extent_data_ref(root_objectid, owner, offset); } again: recow = 0; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) { err = ret; goto fail; } if (parent) { if (!ret) return 0; #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 key.type = BTRFS_EXTENT_REF_V0_KEY; btrfs_release_path(root, path); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret < 0) { err = ret; goto fail; } if (!ret) return 0; #endif goto fail; } leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); while (1) { if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) err = ret; if (ret) goto fail; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); recow = 1; } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != bytenr || key.type != BTRFS_EXTENT_DATA_REF_KEY) goto fail; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); if (match_extent_data_ref(leaf, ref, root_objectid, owner, offset)) { if (recow) { btrfs_release_path(root, path); goto again; } err = 0; break; } path->slots[0]++; } fail: return err; } static noinline int insert_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add) { struct btrfs_key key; struct extent_buffer *leaf; u32 size; u32 num_refs; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_DATA_REF_KEY; key.offset = parent; size = sizeof(struct btrfs_shared_data_ref); } else { key.type = BTRFS_EXTENT_DATA_REF_KEY; key.offset = hash_extent_data_ref(root_objectid, owner, offset); size = sizeof(struct btrfs_extent_data_ref); } ret = btrfs_insert_empty_item(trans, root, path, &key, size); if (ret && ret != -EEXIST) goto fail; leaf = path->nodes[0]; if (parent) { struct btrfs_shared_data_ref *ref; ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); if (ret == 0) { btrfs_set_shared_data_ref_count(leaf, ref, refs_to_add); } else { num_refs = btrfs_shared_data_ref_count(leaf, ref); num_refs += refs_to_add; btrfs_set_shared_data_ref_count(leaf, ref, num_refs); } } else { struct btrfs_extent_data_ref *ref; while (ret == -EEXIST) { ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); if (match_extent_data_ref(leaf, ref, root_objectid, owner, offset)) break; btrfs_release_path(root, 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(root, path); return ret; } static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, int refs_to_drop) { struct btrfs_key key; struct btrfs_extent_data_ref *ref1 = NULL; struct btrfs_shared_data_ref *ref2 = NULL; struct extent_buffer *leaf; u32 num_refs = 0; int ret = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { ref2 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); num_refs = btrfs_shared_data_ref_count(leaf, ref2); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) { struct btrfs_extent_ref_v0 *ref0; ref0 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref_v0); num_refs = btrfs_ref_count_v0(leaf, ref0); #endif } else { BUG(); } BUG_ON(num_refs < refs_to_drop); num_refs -= refs_to_drop; if (num_refs == 0) { ret = btrfs_del_item(trans, root, path); } else { if (key.type == BTRFS_EXTENT_DATA_REF_KEY) btrfs_set_extent_data_ref_count(leaf, ref1, num_refs); else if (key.type == BTRFS_SHARED_DATA_REF_KEY) btrfs_set_shared_data_ref_count(leaf, ref2, num_refs); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 else { struct btrfs_extent_ref_v0 *ref0; ref0 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref_v0); btrfs_set_ref_count_v0(leaf, ref0, num_refs); } #endif btrfs_mark_buffer_dirty(leaf); } return ret; } static noinline u32 extent_data_ref_count(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref) { struct btrfs_key key; struct extent_buffer *leaf; struct btrfs_extent_data_ref *ref1; struct btrfs_shared_data_ref *ref2; u32 num_refs = 0; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (iref) { if (btrfs_extent_inline_ref_type(leaf, iref) == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = (struct btrfs_extent_data_ref *)(&iref->offset); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else { ref2 = (struct btrfs_shared_data_ref *)(iref + 1); num_refs = btrfs_shared_data_ref_count(leaf, ref2); } } else if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { ref1 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_data_ref); num_refs = btrfs_extent_data_ref_count(leaf, ref1); } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { ref2 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_shared_data_ref); num_refs = btrfs_shared_data_ref_count(leaf, ref2); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 } else if (key.type == BTRFS_EXTENT_REF_V0_KEY) { struct btrfs_extent_ref_v0 *ref0; ref0 = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref_v0); num_refs = btrfs_ref_count_v0(leaf, ref0); #endif } else { WARN_ON(1); } return num_refs; } static noinline int lookup_tree_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid) { struct btrfs_key key; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_BLOCK_REF_KEY; key.offset = parent; } else { key.type = BTRFS_TREE_BLOCK_REF_KEY; key.offset = root_objectid; } ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -ENOENT; #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 if (ret == -ENOENT && parent) { btrfs_release_path(root, path); key.type = BTRFS_EXTENT_REF_V0_KEY; ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -ENOENT; } #endif return ret; } static noinline int insert_tree_block_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid) { struct btrfs_key key; int ret; key.objectid = bytenr; if (parent) { key.type = BTRFS_SHARED_BLOCK_REF_KEY; key.offset = parent; } else { key.type = BTRFS_TREE_BLOCK_REF_KEY; key.offset = root_objectid; } ret = btrfs_insert_empty_item(trans, root, path, &key, 0); btrfs_release_path(root, path); return ret; } static inline int extent_ref_type(u64 parent, u64 owner) { int type; if (owner < BTRFS_FIRST_FREE_OBJECTID) { if (parent > 0) type = BTRFS_SHARED_BLOCK_REF_KEY; else type = BTRFS_TREE_BLOCK_REF_KEY; } else { if (parent > 0) type = BTRFS_SHARED_DATA_REF_KEY; else type = BTRFS_EXTENT_DATA_REF_KEY; } return type; } static int find_next_key(struct btrfs_path *path, int level, struct btrfs_key *key) { for (; level < BTRFS_MAX_LEVEL; level++) { if (!path->nodes[level]) break; if (path->slots[level] + 1 >= btrfs_header_nritems(path->nodes[level])) continue; if (level == 0) btrfs_item_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); else btrfs_node_key_to_cpu(path->nodes[level], key, path->slots[level] + 1); return 0; } return 1; } /* * look for inline back ref. if back ref is found, *ref_ret is set * to the address of inline back ref, and 0 is returned. * * if back ref isn't found, *ref_ret is set to the address where it * should be inserted, and -ENOENT is returned. * * if insert is true and there are too many inline back refs, the path * points to the extent item, and -EAGAIN is returned. * * NOTE: inline back refs are ordered in the same way that back ref * items in the tree are ordered. */ static noinline_for_stack int lookup_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref **ref_ret, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset, int insert) { struct btrfs_key key; struct extent_buffer *leaf; struct btrfs_extent_item *ei; struct btrfs_extent_inline_ref *iref; u64 flags; u64 item_size; unsigned long ptr; unsigned long end; int extra_size; int type; int want; int ret; int err = 0; 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; ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1); if (ret < 0) { err = ret; goto out; } BUG_ON(ret); leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 if (item_size < sizeof(*ei)) { if (!insert) { err = -ENOENT; goto out; } ret = convert_extent_item_v0(trans, root, path, owner, extra_size); if (ret < 0) { err = ret; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); } #endif BUG_ON(item_size < sizeof(*ei)); ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); flags = btrfs_extent_flags(leaf, ei); ptr = (unsigned long)(ei + 1); end = (unsigned long)ei + item_size; if (flags & BTRFS_EXTENT_FLAG_TREE_BLOCK) { ptr += sizeof(struct btrfs_tree_block_info); BUG_ON(ptr > end); } else { BUG_ON(!(flags & BTRFS_EXTENT_FLAG_DATA)); } err = -ENOENT; while (1) { if (ptr >= end) { WARN_ON(ptr > end); break; } iref = (struct btrfs_extent_inline_ref *)ptr; type = btrfs_extent_inline_ref_type(leaf, iref); if (want < type) break; if (want > type) { ptr += btrfs_extent_inline_ref_size(type); continue; } if (type == BTRFS_EXTENT_DATA_REF_KEY) { struct btrfs_extent_data_ref *dref; dref = (struct btrfs_extent_data_ref *)(&iref->offset); if (match_extent_data_ref(leaf, dref, root_objectid, owner, offset)) { err = 0; break; } if (hash_extent_data_ref_item(leaf, dref) < hash_extent_data_ref(root_objectid, owner, offset)) break; } else { u64 ref_offset; ref_offset = btrfs_extent_inline_ref_offset(leaf, iref); if (parent > 0) { if (parent == ref_offset) { err = 0; break; } if (ref_offset < parent) break; } else { if (root_objectid == ref_offset) { err = 0; break; } if (ref_offset < root_objectid) break; } } ptr += btrfs_extent_inline_ref_size(type); } if (err == -ENOENT && insert) { if (item_size + extra_size >= BTRFS_MAX_EXTENT_ITEM_SIZE(root)) { err = -EAGAIN; goto out; } /* * To add new inline back ref, we have to make sure * there is no corresponding back ref item. * For simplicity, we just do not add new inline back * ref if there is any kind of item for this block */ if (find_next_key(path, 0, &key) == 0 && key.objectid == bytenr && key.type < BTRFS_BLOCK_GROUP_ITEM_KEY) { err = -EAGAIN; goto out; } } *ref_ret = (struct btrfs_extent_inline_ref *)ptr; out: if (insert) { path->keep_locks = 0; btrfs_unlock_up_safe(path, 1); } return err; } /* * helper to add new inline back ref */ static noinline_for_stack int setup_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct extent_buffer *leaf; struct btrfs_extent_item *ei; unsigned long ptr; unsigned long end; unsigned long item_offset; u64 refs; int size; int type; int ret; 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); ret = btrfs_extend_item(trans, root, path, size); BUG_ON(ret); 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); return 0; } static int lookup_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref **ref_ret, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset) { int ret; ret = lookup_inline_extent_backref(trans, root, path, ref_ret, bytenr, num_bytes, parent, root_objectid, owner, offset, 0); if (ret != -ENOENT) return ret; btrfs_release_path(root, path); *ref_ret = NULL; if (owner < BTRFS_FIRST_FREE_OBJECTID) { ret = lookup_tree_block_ref(trans, root, path, bytenr, parent, root_objectid); } else { ret = lookup_extent_data_ref(trans, root, path, bytenr, parent, root_objectid, owner, offset); } return ret; } /* * helper to update/remove inline back ref */ static noinline_for_stack int update_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, int refs_to_mod, struct btrfs_delayed_extent_op *extent_op) { struct extent_buffer *leaf; struct btrfs_extent_item *ei; struct btrfs_extent_data_ref *dref = NULL; struct btrfs_shared_data_ref *sref = NULL; unsigned long ptr; unsigned long end; u32 item_size; int size; int type; int ret; u64 refs; leaf = path->nodes[0]; ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); refs = btrfs_extent_refs(leaf, ei); WARN_ON(refs_to_mod < 0 && refs + refs_to_mod <= 0); refs += refs_to_mod; btrfs_set_extent_refs(leaf, ei, refs); if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); type = btrfs_extent_inline_ref_type(leaf, iref); if (type == BTRFS_EXTENT_DATA_REF_KEY) { dref = (struct btrfs_extent_data_ref *)(&iref->offset); refs = btrfs_extent_data_ref_count(leaf, dref); } else if (type == BTRFS_SHARED_DATA_REF_KEY) { sref = (struct btrfs_shared_data_ref *)(iref + 1); refs = btrfs_shared_data_ref_count(leaf, sref); } else { refs = 1; BUG_ON(refs_to_mod != -1); } BUG_ON(refs_to_mod < 0 && refs < -refs_to_mod); refs += refs_to_mod; if (refs > 0) { if (type == BTRFS_EXTENT_DATA_REF_KEY) btrfs_set_extent_data_ref_count(leaf, dref, refs); else btrfs_set_shared_data_ref_count(leaf, sref, refs); } else { 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; ret = btrfs_truncate_item(trans, root, path, item_size, 1); BUG_ON(ret); } btrfs_mark_buffer_dirty(leaf); return 0; } static noinline_for_stack int insert_inline_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_extent_inline_ref *iref; int ret; ret = lookup_inline_extent_backref(trans, root, path, &iref, bytenr, num_bytes, parent, root_objectid, owner, offset, 1); if (ret == 0) { BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID); ret = update_inline_extent_backref(trans, root, path, iref, refs_to_add, extent_op); } else if (ret == -ENOENT) { ret = setup_inline_extent_backref(trans, root, path, iref, parent, root_objectid, owner, offset, refs_to_add, extent_op); } return ret; } static int insert_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add) { int ret; if (owner < BTRFS_FIRST_FREE_OBJECTID) { BUG_ON(refs_to_add != 1); ret = insert_tree_block_ref(trans, root, path, bytenr, parent, root_objectid); } else { ret = insert_extent_data_ref(trans, root, path, bytenr, parent, root_objectid, owner, offset, refs_to_add); } return ret; } static int remove_extent_backref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_extent_inline_ref *iref, int refs_to_drop, int is_data) { int ret; BUG_ON(!is_data && refs_to_drop != 1); if (iref) { ret = update_inline_extent_backref(trans, root, path, iref, -refs_to_drop, NULL); } else if (is_data) { ret = remove_extent_data_ref(trans, root, path, refs_to_drop); } else { ret = btrfs_del_item(trans, root, path); } return ret; } static void btrfs_issue_discard(struct block_device *bdev, u64 start, u64 len) { blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_KERNEL, DISCARD_FL_BARRIER); } static int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, u64 num_bytes) { int ret; u64 map_length = num_bytes; struct btrfs_multi_bio *multi = NULL; if (!btrfs_test_opt(root, DISCARD)) return 0; /* Tell the block device(s) that the sectors can be discarded */ ret = btrfs_map_block(&root->fs_info->mapping_tree, READ, bytenr, &map_length, &multi, 0); if (!ret) { struct btrfs_bio_stripe *stripe = multi->stripes; int i; if (map_length > num_bytes) map_length = num_bytes; for (i = 0; i < multi->num_stripes; i++, stripe++) { btrfs_issue_discard(stripe->dev->bdev, stripe->physical, map_length); } kfree(multi); } return ret; } int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset) { int ret; BUG_ON(owner < BTRFS_FIRST_FREE_OBJECTID && root_objectid == BTRFS_TREE_LOG_OBJECTID); if (owner < BTRFS_FIRST_FREE_OBJECTID) { ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes, parent, root_objectid, (int)owner, BTRFS_ADD_DELAYED_REF, NULL); } else { ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes, parent, root_objectid, owner, offset, BTRFS_ADD_DELAYED_REF, NULL); } return ret; } static int __btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset, int refs_to_add, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_path *path; struct extent_buffer *leaf; struct btrfs_extent_item *item; u64 refs; int ret; int err = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 1; path->leave_spinning = 1; /* this will setup the path even if it fails to insert the back ref */ ret = insert_inline_extent_backref(trans, root->fs_info->extent_root, path, bytenr, num_bytes, parent, root_objectid, owner, offset, refs_to_add, extent_op); if (ret == 0) goto out; if (ret != -EAGAIN) { err = ret; goto out; } leaf = path->nodes[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(root->fs_info->extent_root, path); path->reada = 1; path->leave_spinning = 1; /* now insert the actual backref */ ret = insert_extent_backref(trans, root->fs_info->extent_root, path, bytenr, parent, root_objectid, owner, offset, refs_to_add); BUG_ON(ret); out: btrfs_free_path(path); return err; } static int run_delayed_data_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret = 0; struct btrfs_delayed_data_ref *ref; struct btrfs_key ins; u64 parent = 0; u64 ref_root = 0; u64 flags = 0; ins.objectid = node->bytenr; ins.offset = node->num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ref = btrfs_delayed_node_to_data_ref(node); if (node->type == BTRFS_SHARED_DATA_REF_KEY) parent = ref->parent; else ref_root = ref->root; if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { if (extent_op) { BUG_ON(extent_op->update_key); flags |= extent_op->flags_to_set; } ret = alloc_reserved_file_extent(trans, root, parent, ref_root, flags, ref->objectid, ref->offset, &ins, node->ref_mod); } else if (node->action == BTRFS_ADD_DELAYED_REF) { ret = __btrfs_inc_extent_ref(trans, root, node->bytenr, node->num_bytes, parent, ref_root, ref->objectid, ref->offset, node->ref_mod, extent_op); } else if (node->action == BTRFS_DROP_DELAYED_REF) { ret = __btrfs_free_extent(trans, root, node->bytenr, node->num_bytes, parent, ref_root, ref->objectid, ref->offset, node->ref_mod, extent_op); } else { BUG(); } return ret; } static void __run_delayed_extent_op(struct btrfs_delayed_extent_op *extent_op, struct extent_buffer *leaf, struct btrfs_extent_item *ei) { u64 flags = btrfs_extent_flags(leaf, ei); if (extent_op->update_flags) { flags |= extent_op->flags_to_set; btrfs_set_extent_flags(leaf, ei, flags); } if (extent_op->update_key) { struct btrfs_tree_block_info *bi; BUG_ON(!(flags & BTRFS_EXTENT_FLAG_TREE_BLOCK)); bi = (struct btrfs_tree_block_info *)(ei + 1); btrfs_set_tree_block_key(leaf, bi, &extent_op->key); } } static int run_delayed_extent_op(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_key key; struct btrfs_path *path; struct btrfs_extent_item *ei; struct extent_buffer *leaf; u32 item_size; int ret; int err = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; key.objectid = node->bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = node->num_bytes; path->reada = 1; path->leave_spinning = 1; ret = btrfs_search_slot(trans, root->fs_info->extent_root, &key, path, 0, 1); if (ret < 0) { err = ret; goto out; } if (ret > 0) { err = -EIO; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 if (item_size < sizeof(*ei)) { ret = convert_extent_item_v0(trans, root->fs_info->extent_root, path, (u64)-1, 0); if (ret < 0) { err = ret; goto out; } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, path->slots[0]); } #endif BUG_ON(item_size < sizeof(*ei)); ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); __run_delayed_extent_op(extent_op, leaf, ei); btrfs_mark_buffer_dirty(leaf); out: btrfs_free_path(path); return err; } static int run_delayed_tree_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret = 0; struct btrfs_delayed_tree_ref *ref; struct btrfs_key ins; u64 parent = 0; u64 ref_root = 0; ins.objectid = node->bytenr; ins.offset = node->num_bytes; ins.type = BTRFS_EXTENT_ITEM_KEY; ref = btrfs_delayed_node_to_tree_ref(node); if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) parent = ref->parent; else ref_root = ref->root; BUG_ON(node->ref_mod != 1); if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { BUG_ON(!extent_op || !extent_op->update_flags || !extent_op->update_key); ret = alloc_reserved_tree_block(trans, root, parent, ref_root, extent_op->flags_to_set, &extent_op->key, ref->level, &ins); } else if (node->action == BTRFS_ADD_DELAYED_REF) { ret = __btrfs_inc_extent_ref(trans, root, node->bytenr, node->num_bytes, parent, ref_root, ref->level, 0, 1, extent_op); } else if (node->action == BTRFS_DROP_DELAYED_REF) { ret = __btrfs_free_extent(trans, root, node->bytenr, node->num_bytes, parent, ref_root, ref->level, 0, 1, extent_op); } else { BUG(); } return ret; } /* helper function to actually process a single delayed ref entry */ static int run_one_delayed_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_delayed_ref_node *node, struct btrfs_delayed_extent_op *extent_op, int insert_reserved) { int ret; if (btrfs_delayed_ref_is_head(node)) { struct btrfs_delayed_ref_head *head; /* * we've hit the end of the chain and we were supposed * to insert this extent into the tree. But, it got * deleted before we ever needed to insert it, so all * we have to do is clean up the accounting */ BUG_ON(extent_op); head = btrfs_delayed_node_to_head(node); if (insert_reserved) { int mark_free = 0; struct extent_buffer *must_clean = NULL; ret = pin_down_bytes(trans, root, NULL, node->bytenr, node->num_bytes, head->is_data, 1, &must_clean); if (ret > 0) mark_free = 1; if (must_clean) { clean_tree_block(NULL, root, must_clean); btrfs_tree_unlock(must_clean); free_extent_buffer(must_clean); } if (head->is_data) { ret = btrfs_del_csums(trans, root, node->bytenr, node->num_bytes); BUG_ON(ret); } if (mark_free) { ret = btrfs_free_reserved_extent(root, node->bytenr, node->num_bytes); BUG_ON(ret); } } mutex_unlock(&head->mutex); return 0; } if (node->type == BTRFS_TREE_BLOCK_REF_KEY || node->type == BTRFS_SHARED_BLOCK_REF_KEY) ret = run_delayed_tree_ref(trans, root, node, extent_op, insert_reserved); else if (node->type == BTRFS_EXTENT_DATA_REF_KEY || node->type == BTRFS_SHARED_DATA_REF_KEY) ret = run_delayed_data_ref(trans, root, node, extent_op, insert_reserved); else BUG(); return ret; } static noinline struct btrfs_delayed_ref_node * select_delayed_ref(struct btrfs_delayed_ref_head *head) { struct rb_node *node; struct btrfs_delayed_ref_node *ref; int action = BTRFS_ADD_DELAYED_REF; again: /* * select delayed ref of type BTRFS_ADD_DELAYED_REF first. * this prevents ref count from going down to zero when * there still are pending delayed ref. */ node = rb_prev(&head->node.rb_node); while (1) { if (!node) break; ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); if (ref->bytenr != head->node.bytenr) break; if (ref->action == action) return ref; node = rb_prev(node); } if (action == BTRFS_ADD_DELAYED_REF) { action = BTRFS_DROP_DELAYED_REF; goto again; } return NULL; } static noinline int run_clustered_refs(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct list_head *cluster) { struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_node *ref; struct btrfs_delayed_ref_head *locked_ref = NULL; struct btrfs_delayed_extent_op *extent_op; int ret; int count = 0; int must_insert_reserved = 0; delayed_refs = &trans->transaction->delayed_refs; while (1) { if (!locked_ref) { /* pick a new head ref from the cluster list */ if (list_empty(cluster)) break; locked_ref = list_entry(cluster->next, struct btrfs_delayed_ref_head, cluster); /* grab the lock that says we are going to process * all the refs for this head */ ret = btrfs_delayed_ref_lock(trans, locked_ref); /* * we may have dropped the spin lock to get the head * mutex lock, and that might have given someone else * time to free the head. If that's true, it has been * removed from our list and we can move on. */ if (ret == -EAGAIN) { locked_ref = NULL; count++; continue; } } /* * 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; /* * locked_ref is the head node, so we have to go one * node back for any delayed ref updates */ ref = select_delayed_ref(locked_ref); if (!ref) { /* All delayed refs have been processed, Go ahead * and send the head node to run_one_delayed_ref, * so that any accounting fixes can happen */ ref = &locked_ref->node; if (extent_op && must_insert_reserved) { kfree(extent_op); extent_op = NULL; } if (extent_op) { spin_unlock(&delayed_refs->lock); ret = run_delayed_extent_op(trans, root, ref, extent_op); BUG_ON(ret); kfree(extent_op); cond_resched(); spin_lock(&delayed_refs->lock); continue; } list_del_init(&locked_ref->cluster); locked_ref = NULL; } ref->in_tree = 0; rb_erase(&ref->rb_node, &delayed_refs->root); delayed_refs->num_entries--; spin_unlock(&delayed_refs->lock); ret = run_one_delayed_ref(trans, root, ref, extent_op, must_insert_reserved); BUG_ON(ret); btrfs_put_delayed_ref(ref); kfree(extent_op); count++; cond_resched(); spin_lock(&delayed_refs->lock); } return count; } /* * 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. */ int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, struct btrfs_root *root, unsigned long count) { struct rb_node *node; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_node *ref; struct list_head cluster; int ret; int run_all = count == (unsigned long)-1; int run_most = 0; if (root == root->fs_info->extent_root) root = root->fs_info->tree_root; delayed_refs = &trans->transaction->delayed_refs; INIT_LIST_HEAD(&cluster); again: spin_lock(&delayed_refs->lock); if (count == 0) { count = delayed_refs->num_entries * 2; run_most = 1; } while (1) { if (!(run_all || run_most) && delayed_refs->num_heads_ready < 64) break; /* * go find something we can process in the rbtree. We start at * the beginning of the tree, and then build a cluster * of refs to process starting at the first one we are able to * lock */ ret = btrfs_find_ref_cluster(trans, &cluster, delayed_refs->run_delayed_start); if (ret) break; ret = run_clustered_refs(trans, root, &cluster); BUG_ON(ret < 0); count -= min_t(unsigned long, ret, count); if (count == 0) break; } if (run_all) { node = rb_first(&delayed_refs->root); if (!node) goto out; count = (unsigned long)-1; while (node) { ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); if (btrfs_delayed_ref_is_head(ref)) { struct btrfs_delayed_ref_head *head; head = btrfs_delayed_node_to_head(ref); atomic_inc(&ref->refs); spin_unlock(&delayed_refs->lock); mutex_lock(&head->mutex); mutex_unlock(&head->mutex); btrfs_put_delayed_ref(ref); cond_resched(); goto again; } node = rb_next(node); } spin_unlock(&delayed_refs->lock); schedule_timeout(1); goto again; } out: spin_unlock(&delayed_refs->lock); return 0; } int btrfs_set_disk_extent_flags(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 flags, int is_data) { struct btrfs_delayed_extent_op *extent_op; int ret; extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); if (!extent_op) return -ENOMEM; extent_op->flags_to_set = flags; extent_op->update_flags = 1; extent_op->update_key = 0; extent_op->is_data = is_data ? 1 : 0; ret = btrfs_add_delayed_extent_op(trans, bytenr, num_bytes, extent_op); if (ret) kfree(extent_op); return ret; } static noinline int check_delayed_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_delayed_ref_head *head; struct btrfs_delayed_ref_node *ref; struct btrfs_delayed_data_ref *data_ref; struct btrfs_delayed_ref_root *delayed_refs; struct rb_node *node; int ret = 0; ret = -ENOENT; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); head = btrfs_find_delayed_ref_head(trans, bytenr); if (!head) goto out; if (!mutex_trylock(&head->mutex)) { atomic_inc(&head->node.refs); spin_unlock(&delayed_refs->lock); btrfs_release_path(root->fs_info->extent_root, path); mutex_lock(&head->mutex); mutex_unlock(&head->mutex); btrfs_put_delayed_ref(&head->node); return -EAGAIN; } node = rb_prev(&head->node.rb_node); if (!node) goto out_unlock; ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); if (ref->bytenr != bytenr) goto out_unlock; ret = 1; if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) goto out_unlock; data_ref = btrfs_delayed_node_to_data_ref(ref); node = rb_prev(node); if (node) { ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); if (ref->bytenr == bytenr) goto out_unlock; } if (data_ref->root != root->root_key.objectid || data_ref->objectid != objectid || data_ref->offset != offset) goto out_unlock; ret = 0; out_unlock: mutex_unlock(&head->mutex); out: spin_unlock(&delayed_refs->lock); return ret; } static noinline int check_committed_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_root *extent_root = root->fs_info->extent_root; struct extent_buffer *leaf; struct btrfs_extent_data_ref *ref; struct btrfs_extent_inline_ref *iref; struct btrfs_extent_item *ei; struct btrfs_key key; u32 item_size; int ret; key.objectid = bytenr; key.offset = (u64)-1; key.type = BTRFS_EXTENT_ITEM_KEY; ret = btrfs_search_slot(NULL, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(ret == 0); ret = -ENOENT; if (path->slots[0] == 0) goto out; path->slots[0]--; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY) goto out; ret = 1; item_size = btrfs_item_size_nr(leaf, path->slots[0]); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 if (item_size < sizeof(*ei)) { WARN_ON(item_size != sizeof(struct btrfs_extent_item_v0)); goto out; } #endif ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); if (item_size != sizeof(*ei) + btrfs_extent_inline_ref_size(BTRFS_EXTENT_DATA_REF_KEY)) goto out; if (btrfs_extent_generation(leaf, ei) <= btrfs_root_last_snapshot(&root->root_item)) goto out; iref = (struct btrfs_extent_inline_ref *)(ei + 1); if (btrfs_extent_inline_ref_type(leaf, iref) != BTRFS_EXTENT_DATA_REF_KEY) goto out; ref = (struct btrfs_extent_data_ref *)(&iref->offset); if (btrfs_extent_refs(leaf, ei) != btrfs_extent_data_ref_count(leaf, ref) || btrfs_extent_data_ref_root(leaf, ref) != root->root_key.objectid || btrfs_extent_data_ref_objectid(leaf, ref) != objectid || btrfs_extent_data_ref_offset(leaf, ref) != offset) goto out; ret = 0; out: return ret; } int btrfs_cross_ref_exist(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 objectid, u64 offset, u64 bytenr) { struct btrfs_path *path; int ret; int ret2; path = btrfs_alloc_path(); if (!path) return -ENOENT; do { ret = check_committed_ref(trans, root, path, objectid, offset, bytenr); if (ret && ret != -ENOENT) goto out; ret2 = check_delayed_ref(trans, root, path, objectid, offset, bytenr); } while (ret2 == -EAGAIN); if (ret2 && ret2 != -ENOENT) { ret = ret2; goto out; } if (ret != -ENOENT || ret2 != -ENOENT) ret = 0; out: btrfs_free_path(path); return ret; } #if 0 int btrfs_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, u32 nr_extents) { struct btrfs_key key; struct btrfs_file_extent_item *fi; u64 root_gen; u32 nritems; int i; int level; int ret = 0; int shared = 0; if (!root->ref_cows) return 0; if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { shared = 0; root_gen = root->root_key.offset; } else { shared = 1; root_gen = trans->transid - 1; } level = btrfs_header_level(buf); nritems = btrfs_header_nritems(buf); if (level == 0) { struct btrfs_leaf_ref *ref; struct btrfs_extent_info *info; ref = btrfs_alloc_leaf_ref(root, nr_extents); if (!ref) { ret = -ENOMEM; goto out; } ref->root_gen = root_gen; ref->bytenr = buf->start; ref->owner = btrfs_header_owner(buf); ref->generation = btrfs_header_generation(buf); ref->nritems = nr_extents; info = ref->extents; for (i = 0; nr_extents > 0 && i < nritems; i++) { u64 disk_bytenr; btrfs_item_key_to_cpu(buf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; disk_bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (disk_bytenr == 0) continue; info->bytenr = disk_bytenr; info->num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); info->objectid = key.objectid; info->offset = key.offset; info++; } ret = btrfs_add_leaf_ref(root, ref, shared); if (ret == -EEXIST && shared) { struct btrfs_leaf_ref *old; old = btrfs_lookup_leaf_ref(root, ref->bytenr); BUG_ON(!old); btrfs_remove_leaf_ref(root, old); btrfs_free_leaf_ref(root, old); ret = btrfs_add_leaf_ref(root, ref, shared); } WARN_ON(ret); btrfs_free_leaf_ref(root, ref); } out: return ret; } /* when a block goes through cow, we update the reference counts of * everything that block points to. The internal pointers of the block * can be in just about any order, and it is likely to have clusters of * things that are close together and clusters of things that are not. * * To help reduce the seeks that come with updating all of these reference * counts, sort them by byte number before actual updates are done. * * struct refsort is used to match byte number to slot in the btree block. * we sort based on the byte number and then use the slot to actually * find the item. * * struct refsort is smaller than strcut btrfs_item and smaller than * struct btrfs_key_ptr. Since we're currently limited to the page size * for a btree block, there's no way for a kmalloc of refsorts for a * single node to be bigger than a page. */ struct refsort { u64 bytenr; u32 slot; }; /* * for passing into sort() */ static int refsort_cmp(const void *a_void, const void *b_void) { const struct refsort *a = a_void; const struct refsort *b = b_void; if (a->bytenr < b->bytenr) return -1; if (a->bytenr > b->bytenr) return 1; return 0; } #endif static int __btrfs_mod_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref, int inc) { u64 bytenr; u64 num_bytes; u64 parent; u64 ref_root; u32 nritems; struct btrfs_key key; struct btrfs_file_extent_item *fi; int i; int level; int ret = 0; int (*process_func)(struct btrfs_trans_handle *, struct btrfs_root *, u64, u64, u64, u64, u64, u64); ref_root = btrfs_header_owner(buf); nritems = btrfs_header_nritems(buf); level = btrfs_header_level(buf); if (!root->ref_cows && level == 0) return 0; if (inc) process_func = btrfs_inc_extent_ref; else process_func = btrfs_free_extent; if (full_backref) parent = buf->start; else parent = 0; for (i = 0; i < nritems; i++) { if (level == 0) { btrfs_item_key_to_cpu(buf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(buf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(buf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; bytenr = btrfs_file_extent_disk_bytenr(buf, fi); if (bytenr == 0) continue; num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); key.offset -= btrfs_file_extent_offset(buf, fi); ret = process_func(trans, root, bytenr, num_bytes, parent, ref_root, key.objectid, key.offset); if (ret) goto fail; } else { bytenr = btrfs_node_blockptr(buf, i); num_bytes = btrfs_level_size(root, level - 1); ret = process_func(trans, root, bytenr, num_bytes, parent, ref_root, level - 1, 0); if (ret) goto fail; } } return 0; fail: BUG(); return ret; } int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref) { return __btrfs_mod_ref(trans, root, buf, full_backref, 1); } int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, int full_backref) { return __btrfs_mod_ref(trans, root, buf, full_backref, 0); } static int write_one_cache_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_block_group_cache *cache) { int ret; struct btrfs_root *extent_root = root->fs_info->extent_root; unsigned long bi; struct extent_buffer *leaf; ret = btrfs_search_slot(trans, extent_root, &cache->key, path, 0, 1); if (ret < 0) goto fail; BUG_ON(ret); leaf = path->nodes[0]; bi = btrfs_item_ptr_offset(leaf, path->slots[0]); write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); btrfs_mark_buffer_dirty(leaf); btrfs_release_path(extent_root, path); fail: if (ret) return ret; return 0; } static struct btrfs_block_group_cache * next_block_group(struct btrfs_root *root, struct btrfs_block_group_cache *cache) { struct rb_node *node; spin_lock(&root->fs_info->block_group_cache_lock); node = rb_next(&cache->cache_node); btrfs_put_block_group(cache); if (node) { cache = rb_entry(node, struct btrfs_block_group_cache, cache_node); btrfs_get_block_group(cache); } else cache = NULL; spin_unlock(&root->fs_info->block_group_cache_lock); return cache; } int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_block_group_cache *cache; int err = 0; struct btrfs_path *path; u64 last = 0; path = btrfs_alloc_path(); if (!path) return -ENOMEM; while (1) { if (last == 0) { err = btrfs_run_delayed_refs(trans, root, (unsigned long)-1); BUG_ON(err); } cache = btrfs_lookup_first_block_group(root->fs_info, last); while (cache) { if (cache->dirty) break; cache = next_block_group(root, cache); } if (!cache) { if (last == 0) break; last = 0; continue; } cache->dirty = 0; last = cache->key.objectid + cache->key.offset; err = write_one_cache_group(trans, root, path, cache); BUG_ON(err); btrfs_put_block_group(cache); } btrfs_free_path(path); return 0; } int btrfs_extent_readonly(struct btrfs_root *root, u64 bytenr) { struct btrfs_block_group_cache *block_group; int readonly = 0; block_group = btrfs_lookup_block_group(root->fs_info, bytenr); if (!block_group || block_group->ro) readonly = 1; if (block_group) btrfs_put_block_group(block_group); return readonly; } static int update_space_info(struct btrfs_fs_info *info, u64 flags, u64 total_bytes, u64 bytes_used, struct btrfs_space_info **space_info) { struct btrfs_space_info *found; found = __find_space_info(info, flags); if (found) { spin_lock(&found->lock); found->total_bytes += total_bytes; found->bytes_used += bytes_used; found->full = 0; spin_unlock(&found->lock); *space_info = found; return 0; } found = kzalloc(sizeof(*found), GFP_NOFS); if (!found) return -ENOMEM; INIT_LIST_HEAD(&found->block_groups); init_rwsem(&found->groups_sem); init_waitqueue_head(&found->flush_wait); init_waitqueue_head(&found->allocate_wait); spin_lock_init(&found->lock); found->flags = flags; found->total_bytes = total_bytes; found->bytes_used = bytes_used; found->bytes_pinned = 0; found->bytes_reserved = 0; found->bytes_readonly = 0; found->bytes_delalloc = 0; found->full = 0; found->force_alloc = 0; *space_info = found; list_add_rcu(&found->list, &info->space_info); atomic_set(&found->caching_threads, 0); return 0; } static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) { u64 extra_flags = flags & (BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10 | BTRFS_BLOCK_GROUP_DUP); if (extra_flags) { if (flags & BTRFS_BLOCK_GROUP_DATA) fs_info->avail_data_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_METADATA) fs_info->avail_metadata_alloc_bits |= extra_flags; if (flags & BTRFS_BLOCK_GROUP_SYSTEM) fs_info->avail_system_alloc_bits |= extra_flags; } } static void set_block_group_readonly(struct btrfs_block_group_cache *cache) { spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); if (!cache->ro) { cache->space_info->bytes_readonly += cache->key.offset - btrfs_block_group_used(&cache->item); cache->ro = 1; } spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); } u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) { u64 num_devices = root->fs_info->fs_devices->rw_devices; if (num_devices == 1) flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0); if (num_devices < 4) flags &= ~BTRFS_BLOCK_GROUP_RAID10; if ((flags & BTRFS_BLOCK_GROUP_DUP) && (flags & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10))) { flags &= ~BTRFS_BLOCK_GROUP_DUP; } if ((flags & BTRFS_BLOCK_GROUP_RAID1) && (flags & BTRFS_BLOCK_GROUP_RAID10)) { flags &= ~BTRFS_BLOCK_GROUP_RAID1; } if ((flags & BTRFS_BLOCK_GROUP_RAID0) && ((flags & BTRFS_BLOCK_GROUP_RAID1) | (flags & BTRFS_BLOCK_GROUP_RAID10) | (flags & BTRFS_BLOCK_GROUP_DUP))) flags &= ~BTRFS_BLOCK_GROUP_RAID0; return flags; } static u64 btrfs_get_alloc_profile(struct btrfs_root *root, u64 data) { struct btrfs_fs_info *info = root->fs_info; u64 alloc_profile; if (data) { alloc_profile = info->avail_data_alloc_bits & info->data_alloc_profile; data = BTRFS_BLOCK_GROUP_DATA | alloc_profile; } else if (root == root->fs_info->chunk_root) { alloc_profile = info->avail_system_alloc_bits & info->system_alloc_profile; data = BTRFS_BLOCK_GROUP_SYSTEM | alloc_profile; } else { alloc_profile = info->avail_metadata_alloc_bits & info->metadata_alloc_profile; data = BTRFS_BLOCK_GROUP_METADATA | alloc_profile; } return btrfs_reduce_alloc_profile(root, data); } void btrfs_set_inode_space_info(struct btrfs_root *root, struct inode *inode) { u64 alloc_target; alloc_target = btrfs_get_alloc_profile(root, 1); BTRFS_I(inode)->space_info = __find_space_info(root->fs_info, alloc_target); } static u64 calculate_bytes_needed(struct btrfs_root *root, int num_items) { u64 num_bytes; int level; level = BTRFS_MAX_LEVEL - 2; /* * NOTE: these calculations are absolutely the worst possible case. * This assumes that _every_ item we insert will require a new leaf, and * that the tree has grown to its maximum level size. */ /* * for every item we insert we could insert both an extent item and a * extent ref item. Then for ever item we insert, we will need to cow * both the original leaf, plus the leaf to the left and right of it. * * Unless we are talking about the extent root, then we just want the * number of items * 2, since we just need the extent item plus its ref. */ if (root == root->fs_info->extent_root) num_bytes = num_items * 2; else num_bytes = (num_items + (2 * num_items)) * 3; /* * num_bytes is total number of leaves we could need times the leaf * size, and then for every leaf we could end up cow'ing 2 nodes per * level, down to the leaf level. */ num_bytes = (num_bytes * root->leafsize) + (num_bytes * (level * 2)) * root->nodesize; return num_bytes; } /* * Unreserve metadata space for delalloc. If we have less reserved credits than * we have extents, this function does nothing. */ int btrfs_unreserve_metadata_for_delalloc(struct btrfs_root *root, struct inode *inode, int num_items) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *meta_sinfo; u64 num_bytes; u64 alloc_target; bool bug = false; /* get the space info for where the metadata will live */ alloc_target = btrfs_get_alloc_profile(root, 0); meta_sinfo = __find_space_info(info, alloc_target); num_bytes = calculate_bytes_needed(root->fs_info->extent_root, num_items); spin_lock(&meta_sinfo->lock); spin_lock(&BTRFS_I(inode)->accounting_lock); if (BTRFS_I(inode)->reserved_extents <= BTRFS_I(inode)->outstanding_extents) { spin_unlock(&BTRFS_I(inode)->accounting_lock); spin_unlock(&meta_sinfo->lock); return 0; } spin_unlock(&BTRFS_I(inode)->accounting_lock); BTRFS_I(inode)->reserved_extents -= num_items; BUG_ON(BTRFS_I(inode)->reserved_extents < 0); if (meta_sinfo->bytes_delalloc < num_bytes) { bug = true; meta_sinfo->bytes_delalloc = 0; } else { meta_sinfo->bytes_delalloc -= num_bytes; } spin_unlock(&meta_sinfo->lock); BUG_ON(bug); return 0; } static void check_force_delalloc(struct btrfs_space_info *meta_sinfo) { u64 thresh; thresh = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved + meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly + meta_sinfo->bytes_super + meta_sinfo->bytes_root + meta_sinfo->bytes_may_use; thresh = meta_sinfo->total_bytes - thresh; thresh *= 80; do_div(thresh, 100); if (thresh <= meta_sinfo->bytes_delalloc) meta_sinfo->force_delalloc = 1; else meta_sinfo->force_delalloc = 0; } struct async_flush { struct btrfs_root *root; struct btrfs_space_info *info; struct btrfs_work work; }; static noinline void flush_delalloc_async(struct btrfs_work *work) { struct async_flush *async; struct btrfs_root *root; struct btrfs_space_info *info; async = container_of(work, struct async_flush, work); root = async->root; info = async->info; btrfs_start_delalloc_inodes(root, 0); wake_up(&info->flush_wait); btrfs_wait_ordered_extents(root, 0, 0); spin_lock(&info->lock); info->flushing = 0; spin_unlock(&info->lock); wake_up(&info->flush_wait); kfree(async); } static void wait_on_flush(struct btrfs_space_info *info) { DEFINE_WAIT(wait); u64 used; while (1) { prepare_to_wait(&info->flush_wait, &wait, TASK_UNINTERRUPTIBLE); spin_lock(&info->lock); if (!info->flushing) { spin_unlock(&info->lock); break; } used = info->bytes_used + info->bytes_reserved + info->bytes_pinned + info->bytes_readonly + info->bytes_super + info->bytes_root + info->bytes_may_use + info->bytes_delalloc; if (used < info->total_bytes) { spin_unlock(&info->lock); break; } spin_unlock(&info->lock); schedule(); } finish_wait(&info->flush_wait, &wait); } static void flush_delalloc(struct btrfs_root *root, struct btrfs_space_info *info) { struct async_flush *async; bool wait = false; spin_lock(&info->lock); if (!info->flushing) info->flushing = 1; else wait = true; spin_unlock(&info->lock); if (wait) { wait_on_flush(info); return; } async = kzalloc(sizeof(*async), GFP_NOFS); if (!async) goto flush; async->root = root; async->info = info; async->work.func = flush_delalloc_async; btrfs_queue_worker(&root->fs_info->enospc_workers, &async->work); wait_on_flush(info); return; flush: btrfs_start_delalloc_inodes(root, 0); btrfs_wait_ordered_extents(root, 0, 0); spin_lock(&info->lock); info->flushing = 0; spin_unlock(&info->lock); wake_up(&info->flush_wait); } static int maybe_allocate_chunk(struct btrfs_root *root, struct btrfs_space_info *info) { struct btrfs_super_block *disk_super = &root->fs_info->super_copy; struct btrfs_trans_handle *trans; bool wait = false; int ret = 0; u64 min_metadata; u64 free_space; free_space = btrfs_super_total_bytes(disk_super); /* * we allow the metadata to grow to a max of either 10gb or 5% of the * space in the volume. */ min_metadata = min((u64)10 * 1024 * 1024 * 1024, div64_u64(free_space * 5, 100)); if (info->total_bytes >= min_metadata) { spin_unlock(&info->lock); return 0; } if (info->full) { spin_unlock(&info->lock); return 0; } if (!info->allocating_chunk) { info->force_alloc = 1; info->allocating_chunk = 1; } else { wait = true; } spin_unlock(&info->lock); if (wait) { wait_event(info->allocate_wait, !info->allocating_chunk); return 1; } trans = btrfs_start_transaction(root, 1); if (!trans) { ret = -ENOMEM; goto out; } ret = do_chunk_alloc(trans, root->fs_info->extent_root, 4096 + 2 * 1024 * 1024, info->flags, 0); btrfs_end_transaction(trans, root); if (ret) goto out; out: spin_lock(&info->lock); info->allocating_chunk = 0; spin_unlock(&info->lock); wake_up(&info->allocate_wait); if (ret) return 0; return 1; } /* * Reserve metadata space for delalloc. */ int btrfs_reserve_metadata_for_delalloc(struct btrfs_root *root, struct inode *inode, int num_items) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *meta_sinfo; u64 num_bytes; u64 used; u64 alloc_target; int flushed = 0; int force_delalloc; /* get the space info for where the metadata will live */ alloc_target = btrfs_get_alloc_profile(root, 0); meta_sinfo = __find_space_info(info, alloc_target); num_bytes = calculate_bytes_needed(root->fs_info->extent_root, num_items); again: spin_lock(&meta_sinfo->lock); force_delalloc = meta_sinfo->force_delalloc; if (unlikely(!meta_sinfo->bytes_root)) meta_sinfo->bytes_root = calculate_bytes_needed(root, 6); if (!flushed) meta_sinfo->bytes_delalloc += num_bytes; used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved + meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly + meta_sinfo->bytes_super + meta_sinfo->bytes_root + meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc; if (used > meta_sinfo->total_bytes) { flushed++; if (flushed == 1) { if (maybe_allocate_chunk(root, meta_sinfo)) goto again; flushed++; } else { spin_unlock(&meta_sinfo->lock); } if (flushed == 2) { filemap_flush(inode->i_mapping); goto again; } else if (flushed == 3) { flush_delalloc(root, meta_sinfo); goto again; } spin_lock(&meta_sinfo->lock); meta_sinfo->bytes_delalloc -= num_bytes; spin_unlock(&meta_sinfo->lock); printk(KERN_ERR "enospc, has %d, reserved %d\n", BTRFS_I(inode)->outstanding_extents, BTRFS_I(inode)->reserved_extents); dump_space_info(meta_sinfo, 0, 0); return -ENOSPC; } BTRFS_I(inode)->reserved_extents += num_items; check_force_delalloc(meta_sinfo); spin_unlock(&meta_sinfo->lock); if (!flushed && force_delalloc) filemap_flush(inode->i_mapping); return 0; } /* * unreserve num_items number of items worth of metadata space. This needs to * be paired with btrfs_reserve_metadata_space. * * NOTE: if you have the option, run this _AFTER_ you do a * btrfs_end_transaction, since btrfs_end_transaction will run delayed ref * oprations which will result in more used metadata, so we want to make sure we * can do that without issue. */ int btrfs_unreserve_metadata_space(struct btrfs_root *root, int num_items) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *meta_sinfo; u64 num_bytes; u64 alloc_target; bool bug = false; /* get the space info for where the metadata will live */ alloc_target = btrfs_get_alloc_profile(root, 0); meta_sinfo = __find_space_info(info, alloc_target); num_bytes = calculate_bytes_needed(root, num_items); spin_lock(&meta_sinfo->lock); if (meta_sinfo->bytes_may_use < num_bytes) { bug = true; meta_sinfo->bytes_may_use = 0; } else { meta_sinfo->bytes_may_use -= num_bytes; } spin_unlock(&meta_sinfo->lock); BUG_ON(bug); return 0; } /* * Reserve some metadata space for use. We'll calculate the worste case number * of bytes that would be needed to modify num_items number of items. If we * have space, fantastic, if not, you get -ENOSPC. Please call * btrfs_unreserve_metadata_space when you are done for the _SAME_ number of * items you reserved, since whatever metadata you needed should have already * been allocated. * * This will commit the transaction to make more space if we don't have enough * metadata space. THe only time we don't do this is if we're reserving space * inside of a transaction, then we will just return -ENOSPC and it is the * callers responsibility to handle it properly. */ int btrfs_reserve_metadata_space(struct btrfs_root *root, int num_items) { struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *meta_sinfo; u64 num_bytes; u64 used; u64 alloc_target; int retries = 0; /* get the space info for where the metadata will live */ alloc_target = btrfs_get_alloc_profile(root, 0); meta_sinfo = __find_space_info(info, alloc_target); num_bytes = calculate_bytes_needed(root, num_items); again: spin_lock(&meta_sinfo->lock); if (unlikely(!meta_sinfo->bytes_root)) meta_sinfo->bytes_root = calculate_bytes_needed(root, 6); if (!retries) meta_sinfo->bytes_may_use += num_bytes; used = meta_sinfo->bytes_used + meta_sinfo->bytes_reserved + meta_sinfo->bytes_pinned + meta_sinfo->bytes_readonly + meta_sinfo->bytes_super + meta_sinfo->bytes_root + meta_sinfo->bytes_may_use + meta_sinfo->bytes_delalloc; if (used > meta_sinfo->total_bytes) { retries++; if (retries == 1) { if (maybe_allocate_chunk(root, meta_sinfo)) goto again; retries++; } else { spin_unlock(&meta_sinfo->lock); } if (retries == 2) { flush_delalloc(root, meta_sinfo); goto again; } spin_lock(&meta_sinfo->lock); meta_sinfo->bytes_may_use -= num_bytes; spin_unlock(&meta_sinfo->lock); dump_space_info(meta_sinfo, 0, 0); return -ENOSPC; } check_force_delalloc(meta_sinfo); spin_unlock(&meta_sinfo->lock); return 0; } /* * This will check the space that the inode allocates from to make sure we have * enough space for bytes. */ int btrfs_check_data_free_space(struct btrfs_root *root, struct inode *inode, u64 bytes) { struct btrfs_space_info *data_sinfo; u64 used; int ret = 0, committed = 0, flushed = 0; /* make sure bytes are sectorsize aligned */ bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); data_sinfo = BTRFS_I(inode)->space_info; if (!data_sinfo) goto alloc; again: /* make sure we have enough space to handle the data first */ spin_lock(&data_sinfo->lock); used = data_sinfo->bytes_used + data_sinfo->bytes_delalloc + data_sinfo->bytes_reserved + data_sinfo->bytes_pinned + data_sinfo->bytes_readonly + data_sinfo->bytes_may_use + data_sinfo->bytes_super; if (used + bytes > data_sinfo->total_bytes) { struct btrfs_trans_handle *trans; if (!flushed) { spin_unlock(&data_sinfo->lock); flush_delalloc(root, data_sinfo); flushed = 1; goto again; } /* * if we don't have enough free bytes in this space then we need * to alloc a new chunk. */ if (!data_sinfo->full) { u64 alloc_target; data_sinfo->force_alloc = 1; spin_unlock(&data_sinfo->lock); alloc: alloc_target = btrfs_get_alloc_profile(root, 1); trans = btrfs_start_transaction(root, 1); if (!trans) return -ENOMEM; ret = do_chunk_alloc(trans, root->fs_info->extent_root, bytes + 2 * 1024 * 1024, alloc_target, 0); btrfs_end_transaction(trans, root); if (ret) return ret; if (!data_sinfo) { btrfs_set_inode_space_info(root, inode); data_sinfo = BTRFS_I(inode)->space_info; } goto again; } spin_unlock(&data_sinfo->lock); /* commit the current transaction and try again */ if (!committed && !root->fs_info->open_ioctl_trans) { committed = 1; trans = btrfs_join_transaction(root, 1); if (!trans) return -ENOMEM; ret = btrfs_commit_transaction(trans, root); if (ret) return ret; goto again; } printk(KERN_ERR "no space left, need %llu, %llu delalloc bytes" ", %llu bytes_used, %llu bytes_reserved, " "%llu bytes_pinned, %llu bytes_readonly, %llu may use " "%llu total\n", (unsigned long long)bytes, (unsigned long long)data_sinfo->bytes_delalloc, (unsigned long long)data_sinfo->bytes_used, (unsigned long long)data_sinfo->bytes_reserved, (unsigned long long)data_sinfo->bytes_pinned, (unsigned long long)data_sinfo->bytes_readonly, (unsigned long long)data_sinfo->bytes_may_use, (unsigned long long)data_sinfo->total_bytes); return -ENOSPC; } data_sinfo->bytes_may_use += bytes; BTRFS_I(inode)->reserved_bytes += bytes; spin_unlock(&data_sinfo->lock); return 0; } /* * if there was an error for whatever reason after calling * btrfs_check_data_free_space, call this so we can cleanup the counters. */ void btrfs_free_reserved_data_space(struct btrfs_root *root, struct inode *inode, u64 bytes) { struct btrfs_space_info *data_sinfo; /* make sure bytes are sectorsize aligned */ bytes = (bytes + root->sectorsize - 1) & ~((u64)root->sectorsize - 1); data_sinfo = BTRFS_I(inode)->space_info; spin_lock(&data_sinfo->lock); data_sinfo->bytes_may_use -= bytes; BTRFS_I(inode)->reserved_bytes -= bytes; spin_unlock(&data_sinfo->lock); } /* called when we are adding a delalloc extent to the inode's io_tree */ void btrfs_delalloc_reserve_space(struct btrfs_root *root, struct inode *inode, u64 bytes) { struct btrfs_space_info *data_sinfo; /* get the space info for where this inode will be storing its data */ data_sinfo = BTRFS_I(inode)->space_info; /* make sure we have enough space to handle the data first */ spin_lock(&data_sinfo->lock); data_sinfo->bytes_delalloc += bytes; /* * we are adding a delalloc extent without calling * btrfs_check_data_free_space first. This happens on a weird * writepage condition, but shouldn't hurt our accounting */ if (unlikely(bytes > BTRFS_I(inode)->reserved_bytes)) { data_sinfo->bytes_may_use -= BTRFS_I(inode)->reserved_bytes; BTRFS_I(inode)->reserved_bytes = 0; } else { data_sinfo->bytes_may_use -= bytes; BTRFS_I(inode)->reserved_bytes -= bytes; } spin_unlock(&data_sinfo->lock); } /* called when we are clearing an delalloc extent from the inode's io_tree */ void btrfs_delalloc_free_space(struct btrfs_root *root, struct inode *inode, u64 bytes) { struct btrfs_space_info *info; info = BTRFS_I(inode)->space_info; spin_lock(&info->lock); info->bytes_delalloc -= bytes; spin_unlock(&info->lock); } static void force_metadata_allocation(struct btrfs_fs_info *info) { struct list_head *head = &info->space_info; struct btrfs_space_info *found; rcu_read_lock(); list_for_each_entry_rcu(found, head, list) { if (found->flags & BTRFS_BLOCK_GROUP_METADATA) found->force_alloc = 1; } rcu_read_unlock(); } static int do_chunk_alloc(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, u64 alloc_bytes, u64 flags, int force) { struct btrfs_space_info *space_info; struct btrfs_fs_info *fs_info = extent_root->fs_info; u64 thresh; int ret = 0; mutex_lock(&fs_info->chunk_mutex); flags = btrfs_reduce_alloc_profile(extent_root, flags); space_info = __find_space_info(extent_root->fs_info, flags); if (!space_info) { ret = update_space_info(extent_root->fs_info, flags, 0, 0, &space_info); BUG_ON(ret); } BUG_ON(!space_info); spin_lock(&space_info->lock); if (space_info->force_alloc) force = 1; if (space_info->full) { spin_unlock(&space_info->lock); goto out; } thresh = space_info->total_bytes - space_info->bytes_readonly; thresh = div_factor(thresh, 8); if (!force && (space_info->bytes_used + space_info->bytes_pinned + space_info->bytes_reserved + alloc_bytes) < thresh) { spin_unlock(&space_info->lock); goto out; } spin_unlock(&space_info->lock); /* * 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); } ret = btrfs_alloc_chunk(trans, extent_root, flags); spin_lock(&space_info->lock); if (ret) space_info->full = 1; space_info->force_alloc = 0; spin_unlock(&space_info->lock); out: mutex_unlock(&extent_root->fs_info->chunk_mutex); return ret; } static int update_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, int alloc, int mark_free) { struct btrfs_block_group_cache *cache; struct btrfs_fs_info *info = root->fs_info; u64 total = num_bytes; u64 old_val; u64 byte_in_group; /* block accounting for super block */ spin_lock(&info->delalloc_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_lock); while (total) { cache = btrfs_lookup_block_group(info, bytenr); if (!cache) return -1; byte_in_group = bytenr - cache->key.objectid; WARN_ON(byte_in_group > cache->key.offset); spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->dirty = 1; 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_used += num_bytes; cache->space_info->bytes_reserved -= num_bytes; if (cache->ro) cache->space_info->bytes_readonly -= num_bytes; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); } else { old_val -= num_bytes; cache->space_info->bytes_used -= num_bytes; if (cache->ro) cache->space_info->bytes_readonly += num_bytes; btrfs_set_block_group_used(&cache->item, old_val); spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); if (mark_free) { int ret; ret = btrfs_discard_extent(root, bytenr, num_bytes); WARN_ON(ret); ret = btrfs_add_free_space(cache, bytenr, num_bytes); WARN_ON(ret); } } btrfs_put_block_group(cache); total -= num_bytes; bytenr += num_bytes; } return 0; } static u64 first_logical_byte(struct btrfs_root *root, u64 search_start) { struct btrfs_block_group_cache *cache; u64 bytenr; cache = btrfs_lookup_first_block_group(root->fs_info, search_start); if (!cache) return 0; bytenr = cache->key.objectid; btrfs_put_block_group(cache); return bytenr; } /* * this function must be called within transaction */ int btrfs_pin_extent(struct btrfs_root *root, u64 bytenr, u64 num_bytes, int reserved) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_block_group_cache *cache; cache = btrfs_lookup_block_group(fs_info, bytenr); BUG_ON(!cache); spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->pinned += num_bytes; cache->space_info->bytes_pinned += num_bytes; if (reserved) { cache->reserved -= num_bytes; cache->space_info->bytes_reserved -= num_bytes; } spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); btrfs_put_block_group(cache); set_extent_dirty(fs_info->pinned_extents, bytenr, bytenr + num_bytes - 1, GFP_NOFS); return 0; } static int update_reserved_extents(struct btrfs_block_group_cache *cache, u64 num_bytes, int reserve) { spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); if (reserve) { cache->reserved += num_bytes; cache->space_info->bytes_reserved += num_bytes; } else { cache->reserved -= num_bytes; cache->space_info->bytes_reserved -= num_bytes; } spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); return 0; } int btrfs_prepare_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_caching_control *next; struct btrfs_caching_control *caching_ctl; struct btrfs_block_group_cache *cache; down_write(&fs_info->extent_commit_sem); list_for_each_entry_safe(caching_ctl, next, &fs_info->caching_block_groups, list) { cache = caching_ctl->block_group; if (block_group_cache_done(cache)) { cache->last_byte_to_unpin = (u64)-1; list_del_init(&caching_ctl->list); put_caching_control(caching_ctl); } else { cache->last_byte_to_unpin = caching_ctl->progress; } } if (fs_info->pinned_extents == &fs_info->freed_extents[0]) fs_info->pinned_extents = &fs_info->freed_extents[1]; else fs_info->pinned_extents = &fs_info->freed_extents[0]; up_write(&fs_info->extent_commit_sem); return 0; } static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end) { struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_block_group_cache *cache = NULL; u64 len; while (start <= end) { if (!cache || start >= cache->key.objectid + cache->key.offset) { if (cache) btrfs_put_block_group(cache); cache = btrfs_lookup_block_group(fs_info, start); BUG_ON(!cache); } 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); btrfs_add_free_space(cache, start, len); } spin_lock(&cache->space_info->lock); spin_lock(&cache->lock); cache->pinned -= len; cache->space_info->bytes_pinned -= len; spin_unlock(&cache->lock); spin_unlock(&cache->space_info->lock); start += len; } if (cache) btrfs_put_block_group(cache); return 0; } int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_fs_info *fs_info = root->fs_info; struct 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 (1) { ret = find_first_extent_bit(unpin, 0, &start, &end, EXTENT_DIRTY); if (ret) break; ret = btrfs_discard_extent(root, start, end + 1 - start); clear_extent_dirty(unpin, start, end, GFP_NOFS); unpin_extent_range(root, start, end); cond_resched(); } return ret; } static int pin_down_bytes(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, u64 bytenr, u64 num_bytes, int is_data, int reserved, struct extent_buffer **must_clean) { int err = 0; struct extent_buffer *buf; if (is_data) goto pinit; /* * discard is sloooow, and so triggering discards on * individual btree blocks isn't a good plan. Just * pin everything in discard mode. */ if (btrfs_test_opt(root, DISCARD)) goto pinit; buf = btrfs_find_tree_block(root, bytenr, num_bytes); if (!buf) goto pinit; /* we can reuse a block if it hasn't been written * and it is from this transaction. We can't * reuse anything from the tree log root because * it has tiny sub-transactions. */ if (btrfs_buffer_uptodate(buf, 0) && btrfs_try_tree_lock(buf)) { u64 header_owner = btrfs_header_owner(buf); u64 header_transid = btrfs_header_generation(buf); if (header_owner != BTRFS_TREE_LOG_OBJECTID && header_transid == trans->transid && !btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { *must_clean = buf; return 1; } btrfs_tree_unlock(buf); } free_extent_buffer(buf); pinit: if (path) btrfs_set_path_blocking(path); /* unlocks the pinned mutex */ btrfs_pin_extent(root, bytenr, num_bytes, reserved); BUG_ON(err < 0); return 0; } static int __btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner_objectid, u64 owner_offset, int refs_to_drop, struct btrfs_delayed_extent_op *extent_op) { struct btrfs_key key; struct btrfs_path *path; struct btrfs_fs_info *info = root->fs_info; struct btrfs_root *extent_root = info->extent_root; struct extent_buffer *leaf; struct btrfs_extent_item *ei; struct btrfs_extent_inline_ref *iref; int ret; int is_data; int extent_slot = 0; int found_extent = 0; int num_to_del = 1; u32 item_size; u64 refs; path = btrfs_alloc_path(); if (!path) return -ENOMEM; path->reada = 1; path->leave_spinning = 1; is_data = owner_objectid >= BTRFS_FIRST_FREE_OBJECTID; BUG_ON(!is_data && refs_to_drop != 1); ret = lookup_extent_backref(trans, extent_root, path, &iref, bytenr, num_bytes, parent, root_objectid, owner_objectid, owner_offset); if (ret == 0) { extent_slot = path->slots[0]; while (extent_slot >= 0) { btrfs_item_key_to_cpu(path->nodes[0], &key, extent_slot); if (key.objectid != bytenr) break; if (key.type == BTRFS_EXTENT_ITEM_KEY && key.offset == num_bytes) { found_extent = 1; break; } if (path->slots[0] - extent_slot > 5) break; extent_slot--; } #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 item_size = btrfs_item_size_nr(path->nodes[0], extent_slot); if (found_extent && item_size < sizeof(*ei)) found_extent = 0; #endif if (!found_extent) { BUG_ON(iref); ret = remove_extent_backref(trans, extent_root, path, NULL, refs_to_drop, is_data); BUG_ON(ret); btrfs_release_path(extent_root, path); path->leave_spinning = 1; key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); if (ret) { printk(KERN_ERR "umm, got %d back from search" ", was looking for %llu\n", ret, (unsigned long long)bytenr); btrfs_print_leaf(extent_root, path->nodes[0]); } BUG_ON(ret); extent_slot = path->slots[0]; } } else { btrfs_print_leaf(extent_root, path->nodes[0]); WARN_ON(1); printk(KERN_ERR "btrfs unable to find ref byte nr %llu " "parent %llu root %llu owner %llu offset %llu\n", (unsigned long long)bytenr, (unsigned long long)parent, (unsigned long long)root_objectid, (unsigned long long)owner_objectid, (unsigned long long)owner_offset); } leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, extent_slot); #ifdef BTRFS_COMPAT_EXTENT_TREE_V0 if (item_size < sizeof(*ei)) { BUG_ON(found_extent || extent_slot != path->slots[0]); ret = convert_extent_item_v0(trans, extent_root, path, owner_objectid, 0); BUG_ON(ret < 0); btrfs_release_path(extent_root, path); path->leave_spinning = 1; key.objectid = bytenr; key.type = BTRFS_EXTENT_ITEM_KEY; key.offset = num_bytes; ret = btrfs_search_slot(trans, extent_root, &key, path, -1, 1); if (ret) { printk(KERN_ERR "umm, got %d back from search" ", was looking for %llu\n", ret, (unsigned long long)bytenr); btrfs_print_leaf(extent_root, path->nodes[0]); } BUG_ON(ret); extent_slot = path->slots[0]; leaf = path->nodes[0]; item_size = btrfs_item_size_nr(leaf, extent_slot); } #endif BUG_ON(item_size < sizeof(*ei)); ei = btrfs_item_ptr(leaf, extent_slot, struct btrfs_extent_item); if (owner_objectid < BTRFS_FIRST_FREE_OBJECTID) { 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); BUG_ON(refs < refs_to_drop); refs -= refs_to_drop; if (refs > 0) { if (extent_op) __run_delayed_extent_op(extent_op, leaf, ei); /* * In the case of inline back ref, reference count will * be updated by remove_extent_backref */ if (iref) { BUG_ON(!found_extent); } else { btrfs_set_extent_refs(leaf, ei, refs); btrfs_mark_buffer_dirty(leaf); } if (found_extent) { ret = remove_extent_backref(trans, extent_root, path, iref, refs_to_drop, is_data); BUG_ON(ret); } } else { int mark_free = 0; struct extent_buffer *must_clean = NULL; if (found_extent) { BUG_ON(is_data && refs_to_drop != extent_data_ref_count(root, 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; } } ret = pin_down_bytes(trans, root, path, bytenr, num_bytes, is_data, 0, &must_clean); if (ret > 0) mark_free = 1; BUG_ON(ret < 0); /* * it is going to be very rare for someone to be waiting * on the block we're freeing. del_items might need to * schedule, so rather than get fancy, just force it * to blocking here */ if (must_clean) btrfs_set_lock_blocking(must_clean); ret = btrfs_del_items(trans, extent_root, path, path->slots[0], num_to_del); BUG_ON(ret); btrfs_release_path(extent_root, path); if (must_clean) { clean_tree_block(NULL, root, must_clean); btrfs_tree_unlock(must_clean); free_extent_buffer(must_clean); } if (is_data) { ret = btrfs_del_csums(trans, root, bytenr, num_bytes); BUG_ON(ret); } else { invalidate_mapping_pages(info->btree_inode->i_mapping, bytenr >> PAGE_CACHE_SHIFT, (bytenr + num_bytes - 1) >> PAGE_CACHE_SHIFT); } ret = update_block_group(trans, root, bytenr, num_bytes, 0, mark_free); BUG_ON(ret); } btrfs_free_path(path); return ret; } /* * when we free an extent, it is possible (and likely) that we free the last * delayed ref for that extent as well. This searches the delayed ref tree for * a given extent, and if there are no other delayed refs to be processed, it * removes it from the tree. */ static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr) { struct btrfs_delayed_ref_head *head; struct btrfs_delayed_ref_root *delayed_refs; struct btrfs_delayed_ref_node *ref; struct rb_node *node; int ret; delayed_refs = &trans->transaction->delayed_refs; spin_lock(&delayed_refs->lock); head = btrfs_find_delayed_ref_head(trans, bytenr); if (!head) goto out; node = rb_prev(&head->node.rb_node); if (!node) goto out; ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); /* there are still entries for this ref, we can't drop it */ if (ref->bytenr == bytenr) goto out; if (head->extent_op) { if (!head->must_insert_reserved) goto out; kfree(head->extent_op); head->extent_op = NULL; } /* * waiting for the lock here would deadlock. If someone else has it * locked they are already in the process of dropping it anyway */ if (!mutex_trylock(&head->mutex)) goto out; /* * at this point we have a head with no other entries. Go * ahead and process it. */ head->node.in_tree = 0; rb_erase(&head->node.rb_node, &delayed_refs->root); delayed_refs->num_entries--; /* * we don't take a ref on the node because we're removing it from the * tree, so we just steal the ref the tree was holding. */ delayed_refs->num_heads--; if (list_empty(&head->cluster)) delayed_refs->num_heads_ready--; list_del_init(&head->cluster); spin_unlock(&delayed_refs->lock); ret = run_one_delayed_ref(trans, root->fs_info->tree_root, &head->node, head->extent_op, head->must_insert_reserved); BUG_ON(ret); btrfs_put_delayed_ref(&head->node); return 0; out: spin_unlock(&delayed_refs->lock); return 0; } int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, u64 owner, u64 offset) { int ret; /* * tree log blocks never actually go into the extent allocation * tree, just update pinning info and exit early. */ if (root_objectid == BTRFS_TREE_LOG_OBJECTID) { WARN_ON(owner >= BTRFS_FIRST_FREE_OBJECTID); /* unlocks the pinned mutex */ btrfs_pin_extent(root, bytenr, num_bytes, 1); ret = 0; } else if (owner < BTRFS_FIRST_FREE_OBJECTID) { ret = btrfs_add_delayed_tree_ref(trans, bytenr, num_bytes, parent, root_objectid, (int)owner, BTRFS_DROP_DELAYED_REF, NULL); BUG_ON(ret); ret = check_ref_cleanup(trans, root, bytenr); BUG_ON(ret); } else { ret = btrfs_add_delayed_data_ref(trans, bytenr, num_bytes, parent, root_objectid, owner, offset, BTRFS_DROP_DELAYED_REF, NULL); BUG_ON(ret); } return ret; } int btrfs_free_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u32 blocksize, u64 parent, u64 root_objectid, int level) { u64 used; spin_lock(&root->node_lock); used = btrfs_root_used(&root->root_item) - blocksize; btrfs_set_root_used(&root->root_item, used); spin_unlock(&root->node_lock); return btrfs_free_extent(trans, root, bytenr, blocksize, parent, root_objectid, level, 0); } static u64 stripe_align(struct btrfs_root *root, u64 val) { u64 mask = ((u64)root->stripesize - 1); u64 ret = (val + mask) & ~mask; 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. */ static noinline int wait_block_group_cache_progress(struct btrfs_block_group_cache *cache, u64 num_bytes) { struct btrfs_caching_control *caching_ctl; DEFINE_WAIT(wait); caching_ctl = get_caching_control(cache); if (!caching_ctl) return 0; wait_event(caching_ctl->wait, block_group_cache_done(cache) || (cache->free_space >= num_bytes)); put_caching_control(caching_ctl); return 0; } static noinline int wait_block_group_cache_done(struct btrfs_block_group_cache *cache) { struct btrfs_caching_control *caching_ctl; DEFINE_WAIT(wait); caching_ctl = get_caching_control(cache); if (!caching_ctl) return 0; wait_event(caching_ctl->wait, block_group_cache_done(cache)); put_caching_control(caching_ctl); return 0; } enum btrfs_loop_type { LOOP_FIND_IDEAL = 0, LOOP_CACHING_NOWAIT = 1, LOOP_CACHING_WAIT = 2, LOOP_ALLOC_CHUNK = 3, LOOP_NO_EMPTY_SIZE = 4, }; /* * walks the btree of allocated extents and find a hole of a given size. * The key ins is changed to record the hole: * ins->objectid == block start * ins->flags = BTRFS_EXTENT_ITEM_KEY * ins->offset == number of blocks * Any available blocks before search_start are skipped. */ static noinline int find_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *orig_root, u64 num_bytes, u64 empty_size, u64 search_start, u64 search_end, u64 hint_byte, struct btrfs_key *ins, u64 exclude_start, u64 exclude_nr, int data) { int ret = 0; struct btrfs_root *root = orig_root->fs_info->extent_root; struct btrfs_free_cluster *last_ptr = NULL; struct btrfs_block_group_cache *block_group = NULL; int empty_cluster = 2 * 1024 * 1024; int allowed_chunk_alloc = 0; int done_chunk_alloc = 0; struct btrfs_space_info *space_info; int last_ptr_loop = 0; int loop = 0; bool found_uncached_bg = false; bool failed_cluster_refill = false; bool failed_alloc = false; u64 ideal_cache_percent = 0; u64 ideal_cache_offset = 0; WARN_ON(num_bytes < root->sectorsize); btrfs_set_key_type(ins, BTRFS_EXTENT_ITEM_KEY); ins->objectid = 0; ins->offset = 0; space_info = __find_space_info(root->fs_info, data); if (!space_info) { printk(KERN_ERR "No space info for %d\n", data); return -ENOSPC; } if (orig_root->ref_cows || empty_size) allowed_chunk_alloc = 1; if (data & BTRFS_BLOCK_GROUP_METADATA) { last_ptr = &root->fs_info->meta_alloc_cluster; if (!btrfs_test_opt(root, SSD)) empty_cluster = 64 * 1024; } if ((data & BTRFS_BLOCK_GROUP_DATA) && btrfs_test_opt(root, SSD)) { last_ptr = &root->fs_info->data_alloc_cluster; } if (last_ptr) { spin_lock(&last_ptr->lock); if (last_ptr->block_group) hint_byte = last_ptr->window_start; spin_unlock(&last_ptr->lock); } search_start = max(search_start, first_logical_byte(root, 0)); search_start = max(search_start, hint_byte); if (!last_ptr) empty_cluster = 0; if (search_start == hint_byte) { ideal_cache: block_group = btrfs_lookup_block_group(root->fs_info, search_start); /* * we don't want to use the block group if it doesn't match our * allocation bits, or if its not cached. * * However if we are re-searching with an ideal block group * picked out then we don't care that the block group is cached. */ if (block_group && block_group_bits(block_group, data) && (block_group->cached != BTRFS_CACHE_NO || search_start == ideal_cache_offset)) { 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 { goto have_block_group; } } else if (block_group) { btrfs_put_block_group(block_group); } } search: down_read(&space_info->groups_sem); list_for_each_entry(block_group, &space_info->block_groups, list) { u64 offset; int cached; btrfs_get_block_group(block_group); search_start = block_group->key.objectid; have_block_group: if (unlikely(block_group->cached == BTRFS_CACHE_NO)) { u64 free_percent; free_percent = btrfs_block_group_used(&block_group->item); free_percent *= 100; free_percent = div64_u64(free_percent, block_group->key.offset); free_percent = 100 - free_percent; if (free_percent > ideal_cache_percent && likely(!block_group->ro)) { ideal_cache_offset = block_group->key.objectid; ideal_cache_percent = free_percent; } /* * We only want to start kthread caching if we are at * the point where we will wait for caching to make * progress, or if our ideal search is over and we've * found somebody to start caching. */ if (loop > LOOP_CACHING_NOWAIT || (loop > LOOP_FIND_IDEAL && atomic_read(&space_info->caching_threads) < 2)) { ret = cache_block_group(block_group); BUG_ON(ret); } found_uncached_bg = true; /* * If loop is set for cached only, try the next block * group. */ if (loop == LOOP_FIND_IDEAL) goto loop; } cached = block_group_cache_done(block_group); if (unlikely(!cached)) found_uncached_bg = true; if (unlikely(block_group->ro)) goto loop; /* * Ok we want to try and use the cluster allocator, so lets look * there, unless we are on LOOP_NO_EMPTY_SIZE, since we will * have tried the cluster allocator plenty of times at this * point and not have found anything, so we are likely way too * fragmented for the clustering stuff to find anything, so lets * just skip it and let the allocator find whatever block it can * find */ if (last_ptr && loop < LOOP_NO_EMPTY_SIZE) { /* * the refill lock keeps out other * people trying to start a new cluster */ spin_lock(&last_ptr->refill_lock); if (last_ptr->block_group && (last_ptr->block_group->ro || !block_group_bits(last_ptr->block_group, data))) { offset = 0; goto refill_cluster; } offset = btrfs_alloc_from_cluster(block_group, last_ptr, num_bytes, search_start); if (offset) { /* we have a block, we're done */ spin_unlock(&last_ptr->refill_lock); goto checks; } spin_lock(&last_ptr->lock); /* * whoops, this cluster doesn't actually point to * this block group. Get a ref on the block * group is does point to and try again */ if (!last_ptr_loop && last_ptr->block_group && last_ptr->block_group != block_group) { btrfs_put_block_group(block_group); block_group = last_ptr->block_group; btrfs_get_block_group(block_group); spin_unlock(&last_ptr->lock); spin_unlock(&last_ptr->refill_lock); last_ptr_loop = 1; search_start = block_group->key.objectid; /* * we know this block group is properly * in the list because * btrfs_remove_block_group, drops the * cluster before it removes the block * group from the list */ goto have_block_group; } spin_unlock(&last_ptr->lock); refill_cluster: /* * this cluster didn't work out, free it and * start over */ btrfs_return_cluster_to_free_space(NULL, last_ptr); last_ptr_loop = 0; /* allocate a cluster in this block group */ ret = btrfs_find_space_cluster(trans, root, block_group, last_ptr, offset, num_bytes, empty_cluster + empty_size); if (ret == 0) { /* * now pull our allocation out of this * cluster */ offset = btrfs_alloc_from_cluster(block_group, last_ptr, num_bytes, search_start); if (offset) { /* we found one, proceed */ spin_unlock(&last_ptr->refill_lock); goto checks; } } else if (!cached && loop > LOOP_CACHING_NOWAIT && !failed_cluster_refill) { spin_unlock(&last_ptr->refill_lock); failed_cluster_refill = true; wait_block_group_cache_progress(block_group, num_bytes + empty_cluster + empty_size); goto have_block_group; } /* * at this point we either didn't find a cluster * or we weren't able to allocate a block from our * cluster. Free the cluster we've been trying * to use, and go to the next block group */ btrfs_return_cluster_to_free_space(NULL, last_ptr); spin_unlock(&last_ptr->refill_lock); goto loop; } offset = btrfs_find_space_for_alloc(block_group, search_start, num_bytes, empty_size); /* * If we didn't find a chunk, and we haven't failed on this * block group before, and this block group is in the middle of * caching and we are ok with waiting, then go ahead and wait * for progress to be made, and set failed_alloc to true. * * If failed_alloc is true then we've already waited on this * block group once and should move on to the next block group. */ if (!offset && !failed_alloc && !cached && loop > LOOP_CACHING_NOWAIT) { wait_block_group_cache_progress(block_group, num_bytes + empty_size); failed_alloc = true; goto have_block_group; } else if (!offset) { goto loop; } checks: search_start = stripe_align(root, offset); /* move on to the next group */ if (search_start + num_bytes >= search_end) { btrfs_add_free_space(block_group, offset, num_bytes); goto loop; } /* move on to the next group */ if (search_start + num_bytes > block_group->key.objectid + block_group->key.offset) { btrfs_add_free_space(block_group, offset, num_bytes); goto loop; } if (exclude_nr > 0 && (search_start + num_bytes > exclude_start && search_start < exclude_start + exclude_nr)) { search_start = exclude_start + exclude_nr; btrfs_add_free_space(block_group, offset, num_bytes); /* * if search_start is still in this block group * then we just re-search this block group */ if (search_start >= block_group->key.objectid && search_start < (block_group->key.objectid + block_group->key.offset)) goto have_block_group; goto loop; } ins->objectid = search_start; ins->offset = num_bytes; if (offset < search_start) btrfs_add_free_space(block_group, offset, search_start - offset); BUG_ON(offset > search_start); update_reserved_extents(block_group, num_bytes, 1); /* we are all good, lets return */ break; loop: failed_cluster_refill = false; failed_alloc = false; btrfs_put_block_group(block_group); } up_read(&space_info->groups_sem); /* LOOP_FIND_IDEAL, only search caching/cached bg's, and don't wait for * for them to make caching progress. Also * determine the best possible bg to cache * LOOP_CACHING_NOWAIT, search partially cached block groups, kicking * caching kthreads as we move along * LOOP_CACHING_WAIT, search everything, and wait if our bg is caching * LOOP_ALLOC_CHUNK, force a chunk allocation and try again * LOOP_NO_EMPTY_SIZE, set empty_size and empty_cluster to 0 and try * again */ if (!ins->objectid && loop < LOOP_NO_EMPTY_SIZE && (found_uncached_bg || empty_size || empty_cluster || allowed_chunk_alloc)) { if (loop == LOOP_FIND_IDEAL && found_uncached_bg) { found_uncached_bg = false; loop++; if (!ideal_cache_percent && atomic_read(&space_info->caching_threads)) goto search; /* * 1 of the following 2 things have happened so far * * 1) We found an ideal block group for caching that * is mostly full and will cache quickly, so we might * as well wait for it. * * 2) We searched for cached only and we didn't find * anything, and we didn't start any caching kthreads * either, so chances are we will loop through and * start a couple caching kthreads, and then come back * around and just wait for them. This will be slower * because we will have 2 caching kthreads reading at * the same time when we could have just started one * and waited for it to get far enough to give us an * allocation, so go ahead and go to the wait caching * loop. */ loop = LOOP_CACHING_WAIT; search_start = ideal_cache_offset; ideal_cache_percent = 0; goto ideal_cache; } else if (loop == LOOP_FIND_IDEAL) { /* * Didn't find a uncached bg, wait on anything we find * next. */ loop = LOOP_CACHING_WAIT; goto search; } if (loop < LOOP_CACHING_WAIT) { loop++; goto search; } if (loop == LOOP_ALLOC_CHUNK) { empty_size = 0; empty_cluster = 0; } if (allowed_chunk_alloc) { ret = do_chunk_alloc(trans, root, num_bytes + 2 * 1024 * 1024, data, 1); allowed_chunk_alloc = 0; done_chunk_alloc = 1; } else if (!done_chunk_alloc) { space_info->force_alloc = 1; } if (loop < LOOP_NO_EMPTY_SIZE) { loop++; goto search; } ret = -ENOSPC; } else if (!ins->objectid) { ret = -ENOSPC; } /* we found what we needed */ if (ins->objectid) { if (!(data & BTRFS_BLOCK_GROUP_DATA)) trans->block_group = block_group->key.objectid; btrfs_put_block_group(block_group); ret = 0; } return ret; } static void dump_space_info(struct btrfs_space_info *info, u64 bytes, int dump_block_groups) { struct btrfs_block_group_cache *cache; spin_lock(&info->lock); printk(KERN_INFO "space_info has %llu free, is %sfull\n", (unsigned long long)(info->total_bytes - info->bytes_used - info->bytes_pinned - info->bytes_reserved - info->bytes_super), (info->full) ? "" : "not "); printk(KERN_INFO "space_info total=%llu, pinned=%llu, delalloc=%llu," " may_use=%llu, used=%llu, root=%llu, super=%llu, reserved=%llu" "\n", (unsigned long long)info->total_bytes, (unsigned long long)info->bytes_pinned, (unsigned long long)info->bytes_delalloc, (unsigned long long)info->bytes_may_use, (unsigned long long)info->bytes_used, (unsigned long long)info->bytes_root, (unsigned long long)info->bytes_super, (unsigned long long)info->bytes_reserved); spin_unlock(&info->lock); if (!dump_block_groups) return; down_read(&info->groups_sem); list_for_each_entry(cache, &info->block_groups, list) { spin_lock(&cache->lock); printk(KERN_INFO "block group %llu has %llu bytes, %llu used " "%llu pinned %llu reserved\n", (unsigned long long)cache->key.objectid, (unsigned long long)cache->key.offset, (unsigned long long)btrfs_block_group_used(&cache->item), (unsigned long long)cache->pinned, (unsigned long long)cache->reserved); btrfs_dump_free_space(cache, bytes); spin_unlock(&cache->lock); } up_read(&info->groups_sem); } int btrfs_reserve_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 min_alloc_size, u64 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins, u64 data) { int ret; u64 search_start = 0; data = btrfs_get_alloc_profile(root, data); again: /* * the only place that sets empty_size is btrfs_realloc_node, which * is not called recursively on allocations */ if (empty_size || root->ref_cows) ret = do_chunk_alloc(trans, root->fs_info->extent_root, num_bytes + 2 * 1024 * 1024, data, 0); WARN_ON(num_bytes < root->sectorsize); ret = find_free_extent(trans, root, num_bytes, empty_size, search_start, search_end, hint_byte, ins, trans->alloc_exclude_start, trans->alloc_exclude_nr, data); if (ret == -ENOSPC && num_bytes > min_alloc_size) { num_bytes = num_bytes >> 1; num_bytes = num_bytes & ~(root->sectorsize - 1); num_bytes = max(num_bytes, min_alloc_size); do_chunk_alloc(trans, root->fs_info->extent_root, num_bytes, data, 1); goto again; } if (ret == -ENOSPC) { struct btrfs_space_info *sinfo; sinfo = __find_space_info(root->fs_info, data); printk(KERN_ERR "btrfs allocation failed flags %llu, " "wanted %llu\n", (unsigned long long)data, (unsigned long long)num_bytes); dump_space_info(sinfo, num_bytes, 1); } return ret; } int btrfs_free_reserved_extent(struct btrfs_root *root, u64 start, u64 len) { struct btrfs_block_group_cache *cache; int ret = 0; cache = btrfs_lookup_block_group(root->fs_info, start); if (!cache) { printk(KERN_ERR "Unable to find block group for %llu\n", (unsigned long long)start); return -ENOSPC; } ret = btrfs_discard_extent(root, start, len); btrfs_add_free_space(cache, start, len); update_reserved_extents(cache, len, 0); btrfs_put_block_group(cache); return ret; } static int alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 parent, u64 root_objectid, u64 flags, u64 owner, u64 offset, struct btrfs_key *ins, int ref_mod) { int ret; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_extent_item *extent_item; struct btrfs_extent_inline_ref *iref; struct btrfs_path *path; struct extent_buffer *leaf; int type; u32 size; if (parent > 0) type = BTRFS_SHARED_DATA_REF_KEY; else type = BTRFS_EXTENT_DATA_REF_KEY; size = sizeof(*extent_item) + btrfs_extent_inline_ref_size(type); path = btrfs_alloc_path(); BUG_ON(!path); path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, ins, size); BUG_ON(ret); leaf = path->nodes[0]; extent_item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); btrfs_set_extent_refs(leaf, extent_item, ref_mod); btrfs_set_extent_generation(leaf, extent_item, trans->transid); btrfs_set_extent_flags(leaf, extent_item, flags | BTRFS_EXTENT_FLAG_DATA); iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); btrfs_set_extent_inline_ref_type(leaf, iref, type); if (parent > 0) { struct btrfs_shared_data_ref *ref; ref = (struct btrfs_shared_data_ref *)(iref + 1); btrfs_set_extent_inline_ref_offset(leaf, iref, parent); btrfs_set_shared_data_ref_count(leaf, ref, ref_mod); } else { struct btrfs_extent_data_ref *ref; ref = (struct btrfs_extent_data_ref *)(&iref->offset); btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); btrfs_set_extent_data_ref_objectid(leaf, ref, owner); btrfs_set_extent_data_ref_offset(leaf, ref, offset); btrfs_set_extent_data_ref_count(leaf, ref, ref_mod); } btrfs_mark_buffer_dirty(path->nodes[0]); btrfs_free_path(path); ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); if (ret) { printk(KERN_ERR "btrfs update block group failed for %llu " "%llu\n", (unsigned long long)ins->objectid, (unsigned long long)ins->offset); BUG(); } return ret; } static int alloc_reserved_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 parent, u64 root_objectid, u64 flags, struct btrfs_disk_key *key, int level, struct btrfs_key *ins) { int ret; struct btrfs_fs_info *fs_info = root->fs_info; struct btrfs_extent_item *extent_item; struct btrfs_tree_block_info *block_info; struct btrfs_extent_inline_ref *iref; struct btrfs_path *path; struct extent_buffer *leaf; u32 size = sizeof(*extent_item) + sizeof(*block_info) + sizeof(*iref); path = btrfs_alloc_path(); BUG_ON(!path); path->leave_spinning = 1; ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, ins, size); BUG_ON(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); block_info = (struct btrfs_tree_block_info *)(extent_item + 1); btrfs_set_tree_block_key(leaf, block_info, key); btrfs_set_tree_block_level(leaf, block_info, level); iref = (struct btrfs_extent_inline_ref *)(block_info + 1); if (parent > 0) { BUG_ON(!(flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)); btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_SHARED_BLOCK_REF_KEY); btrfs_set_extent_inline_ref_offset(leaf, iref, parent); } else { btrfs_set_extent_inline_ref_type(leaf, iref, BTRFS_TREE_BLOCK_REF_KEY); btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); } btrfs_mark_buffer_dirty(leaf); btrfs_free_path(path); ret = update_block_group(trans, root, ins->objectid, ins->offset, 1, 0); if (ret) { printk(KERN_ERR "btrfs update block group failed for %llu " "%llu\n", (unsigned long long)ins->objectid, (unsigned long long)ins->offset); BUG(); } return ret; } int btrfs_alloc_reserved_file_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 root_objectid, u64 owner, u64 offset, struct btrfs_key *ins) { int ret; BUG_ON(root_objectid == BTRFS_TREE_LOG_OBJECTID); ret = btrfs_add_delayed_data_ref(trans, ins->objectid, ins->offset, 0, root_objectid, owner, offset, BTRFS_ADD_DELAYED_EXTENT, 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, struct btrfs_root *root, u64 root_objectid, u64 owner, u64 offset, struct btrfs_key *ins) { int ret; struct btrfs_block_group_cache *block_group; struct btrfs_caching_control *caching_ctl; u64 start = ins->objectid; u64 num_bytes = ins->offset; block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); cache_block_group(block_group); caching_ctl = get_caching_control(block_group); if (!caching_ctl) { BUG_ON(!block_group_cache_done(block_group)); ret = btrfs_remove_free_space(block_group, start, num_bytes); BUG_ON(ret); } else { mutex_lock(&caching_ctl->mutex); if (start >= caching_ctl->progress) { ret = add_excluded_extent(root, start, num_bytes); BUG_ON(ret); } else if (start + num_bytes <= caching_ctl->progress) { ret = btrfs_remove_free_space(block_group, start, num_bytes); BUG_ON(ret); } else { num_bytes = caching_ctl->progress - start; ret = btrfs_remove_free_space(block_group, start, num_bytes); BUG_ON(ret); start = caching_ctl->progress; num_bytes = ins->objectid + ins->offset - caching_ctl->progress; ret = add_excluded_extent(root, start, num_bytes); BUG_ON(ret); } mutex_unlock(&caching_ctl->mutex); put_caching_control(caching_ctl); } update_reserved_extents(block_group, ins->offset, 1); btrfs_put_block_group(block_group); ret = alloc_reserved_file_extent(trans, root, 0, root_objectid, 0, owner, offset, ins, 1); return ret; } /* * finds a free extent and does all the dirty work required for allocation * returns the key for the extent through ins, and a tree buffer for * the first block of the extent through buf. * * returns 0 if everything worked, non-zero otherwise. */ static int alloc_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 num_bytes, u64 parent, u64 root_objectid, struct btrfs_disk_key *key, int level, u64 empty_size, u64 hint_byte, u64 search_end, struct btrfs_key *ins) { int ret; u64 flags = 0; ret = btrfs_reserve_extent(trans, root, num_bytes, num_bytes, empty_size, hint_byte, search_end, ins, 0); if (ret) return ret; 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) { struct btrfs_delayed_extent_op *extent_op; extent_op = kmalloc(sizeof(*extent_op), GFP_NOFS); BUG_ON(!extent_op); 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 = 1; extent_op->update_flags = 1; extent_op->is_data = 0; ret = btrfs_add_delayed_tree_ref(trans, ins->objectid, ins->offset, parent, root_objectid, level, BTRFS_ADD_DELAYED_EXTENT, extent_op); BUG_ON(ret); } if (root_objectid == root->root_key.objectid) { u64 used; spin_lock(&root->node_lock); used = btrfs_root_used(&root->root_item) + num_bytes; btrfs_set_root_used(&root->root_item, used); spin_unlock(&root->node_lock); } return ret; } struct extent_buffer *btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytenr, u32 blocksize, int level) { struct extent_buffer *buf; buf = btrfs_find_create_tree_block(root, bytenr, blocksize); if (!buf) return ERR_PTR(-ENOMEM); btrfs_set_header_generation(buf, trans->transid); btrfs_set_buffer_lockdep_class(buf, level); btrfs_tree_lock(buf); clean_tree_block(trans, root, buf); btrfs_set_lock_blocking(buf); btrfs_set_buffer_uptodate(buf); if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { /* * we allow two log transactions at a time, use different * EXENT bit to differentiate dirty pages. */ if (root->log_transid % 2 == 0) set_extent_dirty(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); else set_extent_new(&root->dirty_log_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } else { set_extent_dirty(&trans->transaction->dirty_pages, buf->start, buf->start + buf->len - 1, GFP_NOFS); } trans->blocks_used++; /* this returns a buffer locked for blocking */ return buf; } /* * helper function to allocate a block for a given tree * returns the tree buffer or NULL. */ struct extent_buffer *btrfs_alloc_free_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, u32 blocksize, u64 parent, u64 root_objectid, struct btrfs_disk_key *key, int level, u64 hint, u64 empty_size) { struct btrfs_key ins; int ret; struct extent_buffer *buf; ret = alloc_tree_block(trans, root, blocksize, parent, root_objectid, key, level, empty_size, hint, (u64)-1, &ins); if (ret) { BUG_ON(ret > 0); return ERR_PTR(ret); } buf = btrfs_init_new_buffer(trans, root, ins.objectid, blocksize, level); return buf; } struct walk_control { u64 refs[BTRFS_MAX_LEVEL]; u64 flags[BTRFS_MAX_LEVEL]; struct btrfs_key update_progress; int stage; int level; int shared_level; int update_ref; int keep_locks; int reada_slot; int reada_count; }; #define DROP_REFERENCE 1 #define UPDATE_BACKREF 2 static noinline void reada_walk_down(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct walk_control *wc, struct btrfs_path *path) { u64 bytenr; u64 generation; u64 refs; u64 flags; u64 last = 0; u32 nritems; u32 blocksize; struct btrfs_key key; struct extent_buffer *eb; int ret; int slot; int nread = 0; if (path->slots[wc->level] < wc->reada_slot) { wc->reada_count = wc->reada_count * 2 / 3; wc->reada_count = max(wc->reada_count, 2); } else { wc->reada_count = wc->reada_count * 3 / 2; wc->reada_count = min_t(int, wc->reada_count, BTRFS_NODEPTRS_PER_BLOCK(root)); } eb = path->nodes[wc->level]; nritems = btrfs_header_nritems(eb); blocksize = btrfs_level_size(root, wc->level - 1); for (slot = path->slots[wc->level]; slot < nritems; slot++) { if (nread >= wc->reada_count) break; cond_resched(); bytenr = btrfs_node_blockptr(eb, slot); generation = btrfs_node_ptr_generation(eb, slot); if (slot == path->slots[wc->level]) goto reada; if (wc->stage == UPDATE_BACKREF && generation <= root->root_key.offset) continue; /* We don't lock the tree block, it's OK to be racy here */ ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize, &refs, &flags); BUG_ON(ret); 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: ret = readahead_tree_block(root, bytenr, blocksize, generation); if (ret) break; last = bytenr + blocksize; nread++; } wc->reada_slot = slot; } /* * hepler to process tree block while walking down the tree. * * when wc->stage == UPDATE_BACKREF, this function updates * back refs for pointers in the block. * * NOTE: return value 1 means we should stop walking down. */ static noinline int walk_down_proc(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int lookup_info) { int level = wc->level; struct extent_buffer *eb = path->nodes[level]; u64 flag = BTRFS_BLOCK_FLAG_FULL_BACKREF; int ret; if (wc->stage == UPDATE_BACKREF && btrfs_header_owner(eb) != root->root_key.objectid) return 1; /* * when reference count of tree block is 1, it won't increase * again. once full backref flag is set, we never clear it. */ if (lookup_info && ((wc->stage == DROP_REFERENCE && wc->refs[level] != 1) || (wc->stage == UPDATE_BACKREF && !(wc->flags[level] & flag)))) { BUG_ON(!path->locks[level]); ret = btrfs_lookup_extent_info(trans, root, eb->start, eb->len, &wc->refs[level], &wc->flags[level]); BUG_ON(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(eb); 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); ret = btrfs_dec_ref(trans, root, eb, 0); BUG_ON(ret); ret = btrfs_set_disk_extent_flags(trans, root, eb->start, eb->len, flag, 0); BUG_ON(ret); 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(eb); path->locks[level] = 0; } return 0; } /* * hepler to process tree block pointer. * * when wc->stage == DROP_REFERENCE, this function checks * reference count of the block pointed to. if the block * is shared and we need update back refs for the subtree * rooted at the block, this function changes wc->stage to * UPDATE_BACKREF. if the block is shared and there is no * need to update back, this function drops the reference * to the block. * * NOTE: return value 1 means we should stop walking down. */ static noinline int do_walk_down(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int *lookup_info) { u64 bytenr; u64 generation; u64 parent; u32 blocksize; struct btrfs_key key; struct extent_buffer *next; int level = wc->level; int reada = 0; int ret = 0; generation = btrfs_node_ptr_generation(path->nodes[level], path->slots[level]); /* * if the lower level block was created before the snapshot * was created, we know there is no need to update back refs * for the subtree */ if (wc->stage == UPDATE_BACKREF && generation <= root->root_key.offset) { *lookup_info = 1; return 1; } bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); blocksize = btrfs_level_size(root, level - 1); next = btrfs_find_tree_block(root, bytenr, blocksize); if (!next) { next = btrfs_find_create_tree_block(root, bytenr, blocksize); if (!next) return -ENOMEM; reada = 1; } btrfs_tree_lock(next); btrfs_set_lock_blocking(next); ret = btrfs_lookup_extent_info(trans, root, bytenr, blocksize, &wc->refs[level - 1], &wc->flags[level - 1]); BUG_ON(ret); BUG_ON(wc->refs[level - 1] == 0); *lookup_info = 0; if (wc->stage == DROP_REFERENCE) { if (wc->refs[level - 1] > 1) { 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)) { btrfs_tree_unlock(next); free_extent_buffer(next); next = NULL; *lookup_info = 1; } if (!next) { if (reada && level == 1) reada_walk_down(trans, root, wc, path); next = read_tree_block(root, bytenr, blocksize, generation); btrfs_tree_lock(next); btrfs_set_lock_blocking(next); } level--; BUG_ON(level != btrfs_header_level(next)); path->nodes[level] = next; path->slots[level] = 0; path->locks[level] = 1; wc->level = level; if (wc->level == 1) wc->reada_slot = 0; return 0; skip: wc->refs[level - 1] = 0; wc->flags[level - 1] = 0; if (wc->stage == DROP_REFERENCE) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { parent = path->nodes[level]->start; } else { BUG_ON(root->root_key.objectid != btrfs_header_owner(path->nodes[level])); parent = 0; } ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent, root->root_key.objectid, level - 1, 0); BUG_ON(ret); } btrfs_tree_unlock(next); free_extent_buffer(next); *lookup_info = 1; return 1; } /* * hepler to process tree block while walking up the tree. * * when wc->stage == DROP_REFERENCE, this function drops * reference count on the block. * * when wc->stage == UPDATE_BACKREF, this function changes * wc->stage back to DROP_REFERENCE if we changed wc->stage * to UPDATE_BACKREF previously while processing the block. * * NOTE: return value 1 means we should stop walking up. */ static noinline int walk_up_proc(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc) { int ret = 0; int level = wc->level; struct extent_buffer *eb = path->nodes[level]; u64 parent = 0; if (wc->stage == UPDATE_BACKREF) { BUG_ON(wc->shared_level < level); if (level < wc->shared_level) goto out; ret = find_next_key(path, level + 1, &wc->update_progress); if (ret > 0) wc->update_ref = 0; wc->stage = DROP_REFERENCE; wc->shared_level = -1; path->slots[level] = 0; /* * check reference count again if the block isn't locked. * we should start walking down the tree again if reference * count is one. */ if (!path->locks[level]) { BUG_ON(level == 0); btrfs_tree_lock(eb); btrfs_set_lock_blocking(eb); path->locks[level] = 1; ret = btrfs_lookup_extent_info(trans, root, eb->start, eb->len, &wc->refs[level], &wc->flags[level]); BUG_ON(ret); BUG_ON(wc->refs[level] == 0); if (wc->refs[level] == 1) { btrfs_tree_unlock(eb); 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); } /* make block locked assertion in clean_tree_block happy */ if (!path->locks[level] && btrfs_header_generation(eb) == trans->transid) { btrfs_tree_lock(eb); btrfs_set_lock_blocking(eb); path->locks[level] = 1; } clean_tree_block(trans, root, eb); } if (eb == root->node) { if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = eb->start; else BUG_ON(root->root_key.objectid != btrfs_header_owner(eb)); } else { if (wc->flags[level + 1] & BTRFS_BLOCK_FLAG_FULL_BACKREF) parent = path->nodes[level + 1]->start; else BUG_ON(root->root_key.objectid != btrfs_header_owner(path->nodes[level + 1])); } ret = btrfs_free_extent(trans, root, eb->start, eb->len, parent, root->root_key.objectid, level, 0); BUG_ON(ret); out: wc->refs[level] = 0; wc->flags[level] = 0; return ret; } static noinline int walk_down_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc) { int level = wc->level; int lookup_info = 1; int ret; while (level >= 0) { ret = walk_down_proc(trans, root, path, wc, lookup_info); if (ret > 0) break; if (level == 0) break; if (path->slots[level] >= btrfs_header_nritems(path->nodes[level])) break; ret = do_walk_down(trans, root, path, wc, &lookup_info); if (ret > 0) { path->slots[level]++; continue; } else if (ret < 0) return ret; level = wc->level; } return 0; } static noinline int walk_up_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct walk_control *wc, int max_level) { int level = wc->level; int ret; path->slots[level] = btrfs_header_nritems(path->nodes[level]); while (level < max_level && path->nodes[level]) { wc->level = level; if (path->slots[level] + 1 < btrfs_header_nritems(path->nodes[level])) { path->slots[level]++; return 0; } else { ret = walk_up_proc(trans, root, path, wc); if (ret > 0) return 0; if (path->locks[level]) { btrfs_tree_unlock(path->nodes[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. */ int btrfs_drop_snapshot(struct btrfs_root *root, int update_ref) { struct btrfs_path *path; struct btrfs_trans_handle *trans; struct btrfs_root *tree_root = root->fs_info->tree_root; struct btrfs_root_item *root_item = &root->root_item; struct walk_control *wc; struct btrfs_key key; int err = 0; int ret; int level; path = btrfs_alloc_path(); BUG_ON(!path); wc = kzalloc(sizeof(*wc), GFP_NOFS); BUG_ON(!wc); trans = btrfs_start_transaction(tree_root, 1); if (btrfs_disk_key_objectid(&root_item->drop_progress) == 0) { level = btrfs_header_level(root->node); path->nodes[level] = btrfs_lock_root_node(root); btrfs_set_lock_blocking(path->nodes[level]); path->slots[level] = 0; path->locks[level] = 1; 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; } WARN_ON(ret > 0); /* * unlock our path, this is safe because only this * function is allowed to delete this snapshot */ btrfs_unlock_up_safe(path, 0); level = btrfs_header_level(root->node); while (1) { btrfs_tree_lock(path->nodes[level]); btrfs_set_lock_blocking(path->nodes[level]); ret = btrfs_lookup_extent_info(trans, root, path->nodes[level]->start, path->nodes[level]->len, &wc->refs[level], &wc->flags[level]); BUG_ON(ret); BUG_ON(wc->refs[level] == 0); if (level == root_item->drop_level) break; btrfs_tree_unlock(path->nodes[level]); WARN_ON(wc->refs[level] != 1); level--; } } wc->level = level; wc->shared_level = -1; wc->stage = DROP_REFERENCE; wc->update_ref = update_ref; wc->keep_locks = 0; wc->reada_count = BTRFS_NODEPTRS_PER_BLOCK(root); while (1) { ret = walk_down_tree(trans, root, path, wc); if (ret < 0) { err = ret; break; } ret = walk_up_tree(trans, root, path, wc, BTRFS_MAX_LEVEL); if (ret < 0) { err = ret; break; } if (ret > 0) { BUG_ON(wc->stage != DROP_REFERENCE); break; } if (wc->stage == DROP_REFERENCE) { level = wc->level; btrfs_node_key(path->nodes[level], &root_item->drop_progress, path->slots[level]); root_item->drop_level = level; } BUG_ON(wc->level == 0); if (trans->transaction->in_commit || trans->transaction->delayed_refs.flushing) { ret = btrfs_update_root(trans, tree_root, &root->root_key, root_item); BUG_ON(ret); btrfs_end_transaction(trans, tree_root); trans = btrfs_start_transaction(tree_root, 1); } else { unsigned long update; update = trans->delayed_ref_updates; trans->delayed_ref_updates = 0; if (update) btrfs_run_delayed_refs(trans, tree_root, update); } } btrfs_release_path(root, path); BUG_ON(err); ret = btrfs_del_root(trans, tree_root, &root->root_key); BUG_ON(ret); if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { ret = btrfs_find_last_root(tree_root, root->root_key.objectid, NULL, NULL); BUG_ON(ret < 0); if (ret > 0) { ret = btrfs_del_orphan_item(trans, tree_root, root->root_key.objectid); BUG_ON(ret); } } if (root->in_radix) { btrfs_free_fs_root(tree_root->fs_info, root); } else { free_extent_buffer(root->node); free_extent_buffer(root->commit_root); kfree(root); } out: btrfs_end_transaction(trans, tree_root); kfree(wc); btrfs_free_path(path); return err; } /* * drop subtree rooted at tree block 'node'. * * NOTE: this function will unlock and release tree block 'node' */ int btrfs_drop_subtree(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *node, struct extent_buffer *parent) { struct btrfs_path *path; struct walk_control *wc; int level; int parent_level; int ret = 0; int wret; BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); path = btrfs_alloc_path(); BUG_ON(!path); wc = kzalloc(sizeof(*wc), GFP_NOFS); BUG_ON(!wc); 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] = 1; 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(root); while (1) { wret = walk_down_tree(trans, root, path, wc); if (wret < 0) { ret = wret; break; } wret = walk_up_tree(trans, root, path, wc, parent_level); if (wret < 0) ret = wret; if (wret != 0) break; } kfree(wc); btrfs_free_path(path); return ret; } #if 0 static unsigned long calc_ra(unsigned long start, unsigned long last, unsigned long nr) { return min(last, start + nr - 1); } static noinline int relocate_inode_pages(struct inode *inode, u64 start, u64 len) { u64 page_start; u64 page_end; unsigned long first_index; unsigned long last_index; unsigned long i; struct page *page; struct extent_io_tree *io_tree = &BTRFS_I(inode)->io_tree; struct file_ra_state *ra; struct btrfs_ordered_extent *ordered; unsigned int total_read = 0; unsigned int total_dirty = 0; int ret = 0; ra = kzalloc(sizeof(*ra), GFP_NOFS); mutex_lock(&inode->i_mutex); first_index = start >> PAGE_CACHE_SHIFT; last_index = (start + len - 1) >> PAGE_CACHE_SHIFT; /* make sure the dirty trick played by the caller work */ ret = invalidate_inode_pages2_range(inode->i_mapping, first_index, last_index); if (ret) goto out_unlock; file_ra_state_init(ra, inode->i_mapping); for (i = first_index ; i <= last_index; i++) { if (total_read % ra->ra_pages == 0) { btrfs_force_ra(inode->i_mapping, ra, NULL, i, calc_ra(i, last_index, ra->ra_pages)); } total_read++; again: if (((u64)i << PAGE_CACHE_SHIFT) > i_size_read(inode)) BUG_ON(1); page = grab_cache_page(inode->i_mapping, i); if (!page) { ret = -ENOMEM; goto out_unlock; } if (!PageUptodate(page)) { btrfs_readpage(NULL, page); lock_page(page); if (!PageUptodate(page)) { unlock_page(page); page_cache_release(page); ret = -EIO; goto out_unlock; } } wait_on_page_writeback(page); page_start = (u64)page->index << PAGE_CACHE_SHIFT; page_end = page_start + PAGE_CACHE_SIZE - 1; lock_extent(io_tree, page_start, page_end, GFP_NOFS); ordered = btrfs_lookup_ordered_extent(inode, page_start); if (ordered) { unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); goto again; } set_page_extent_mapped(page); if (i == first_index) set_extent_bits(io_tree, page_start, page_end, EXTENT_BOUNDARY, GFP_NOFS); btrfs_set_extent_delalloc(inode, page_start, page_end); set_page_dirty(page); total_dirty++; unlock_extent(io_tree, page_start, page_end, GFP_NOFS); unlock_page(page); page_cache_release(page); } out_unlock: kfree(ra); mutex_unlock(&inode->i_mutex); balance_dirty_pages_ratelimited_nr(inode->i_mapping, total_dirty); return ret; } static noinline int relocate_data_extent(struct inode *reloc_inode, struct btrfs_key *extent_key, u64 offset) { struct btrfs_root *root = BTRFS_I(reloc_inode)->root; struct extent_map_tree *em_tree = &BTRFS_I(reloc_inode)->extent_tree; struct extent_map *em; u64 start = extent_key->objectid - offset; u64 end = start + extent_key->offset - 1; em = alloc_extent_map(GFP_NOFS); BUG_ON(!em || IS_ERR(em)); em->start = start; em->len = extent_key->offset; em->block_len = extent_key->offset; em->block_start = extent_key->objectid; em->bdev = root->fs_info->fs_devices->latest_bdev; set_bit(EXTENT_FLAG_PINNED, &em->flags); /* setup extent map to cheat btrfs_readpage */ lock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); while (1) { int ret; write_lock(&em_tree->lock); ret = add_extent_mapping(em_tree, em); write_unlock(&em_tree->lock); if (ret != -EEXIST) { free_extent_map(em); break; } btrfs_drop_extent_cache(reloc_inode, start, end, 0); } unlock_extent(&BTRFS_I(reloc_inode)->io_tree, start, end, GFP_NOFS); return relocate_inode_pages(reloc_inode, start, extent_key->offset); } struct btrfs_ref_path { u64 extent_start; u64 nodes[BTRFS_MAX_LEVEL]; u64 root_objectid; u64 root_generation; u64 owner_objectid; u32 num_refs; int lowest_level; int current_level; int shared_level; struct btrfs_key node_keys[BTRFS_MAX_LEVEL]; u64 new_nodes[BTRFS_MAX_LEVEL]; }; struct disk_extent { u64 ram_bytes; u64 disk_bytenr; u64 disk_num_bytes; u64 offset; u64 num_bytes; u8 compression; u8 encryption; u16 other_encoding; }; static int is_cowonly_root(u64 root_objectid) { if (root_objectid == BTRFS_ROOT_TREE_OBJECTID || root_objectid == BTRFS_EXTENT_TREE_OBJECTID || root_objectid == BTRFS_CHUNK_TREE_OBJECTID || root_objectid == BTRFS_DEV_TREE_OBJECTID || root_objectid == BTRFS_TREE_LOG_OBJECTID || root_objectid == BTRFS_CSUM_TREE_OBJECTID) return 1; return 0; } static noinline int __next_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path, int first_time) { struct extent_buffer *leaf; struct btrfs_path *path; struct btrfs_extent_ref *ref; struct btrfs_key key; struct btrfs_key found_key; u64 bytenr; u32 nritems; int level; int ret = 1; path = btrfs_alloc_path(); if (!path) return -ENOMEM; if (first_time) { ref_path->lowest_level = -1; ref_path->current_level = -1; ref_path->shared_level = -1; goto walk_up; } walk_down: level = ref_path->current_level - 1; while (level >= -1) { u64 parent; if (level < ref_path->lowest_level) break; if (level >= 0) bytenr = ref_path->nodes[level]; else bytenr = ref_path->extent_start; BUG_ON(bytenr == 0); parent = ref_path->nodes[level + 1]; ref_path->nodes[level + 1] = 0; ref_path->current_level = level; BUG_ON(parent == 0); key.objectid = bytenr; key.offset = parent + 1; key.type = BTRFS_EXTENT_REF_KEY; ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); if (ret < 0) goto out; BUG_ON(ret == 0); leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(extent_root, path); if (ret < 0) goto out; if (ret > 0) goto next; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid == bytenr && found_key.type == BTRFS_EXTENT_REF_KEY) { if (level < ref_path->shared_level) ref_path->shared_level = level; goto found; } next: level--; btrfs_release_path(extent_root, path); cond_resched(); } /* reached lowest level */ ret = 1; goto out; walk_up: level = ref_path->current_level; while (level < BTRFS_MAX_LEVEL - 1) { u64 ref_objectid; if (level >= 0) bytenr = ref_path->nodes[level]; else bytenr = ref_path->extent_start; BUG_ON(bytenr == 0); key.objectid = bytenr; key.offset = 0; key.type = BTRFS_EXTENT_REF_KEY; ret = btrfs_search_slot(trans, extent_root, &key, path, 0, 0); if (ret < 0) goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(extent_root, path); if (ret < 0) goto out; if (ret > 0) { /* the extent was freed by someone */ if (ref_path->lowest_level == level) goto out; btrfs_release_path(extent_root, path); goto walk_down; } leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.objectid != bytenr || found_key.type != BTRFS_EXTENT_REF_KEY) { /* the extent was freed by someone */ if (ref_path->lowest_level == level) { ret = 1; goto out; } btrfs_release_path(extent_root, path); goto walk_down; } found: ref = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_ref); ref_objectid = btrfs_ref_objectid(leaf, ref); if (ref_objectid < BTRFS_FIRST_FREE_OBJECTID) { if (first_time) { level = (int)ref_objectid; BUG_ON(level >= BTRFS_MAX_LEVEL); ref_path->lowest_level = level; ref_path->current_level = level; ref_path->nodes[level] = bytenr; } else { WARN_ON(ref_objectid != level); } } else { WARN_ON(level != -1); } first_time = 0; if (ref_path->lowest_level == level) { ref_path->owner_objectid = ref_objectid; ref_path->num_refs = btrfs_ref_num_refs(leaf, ref); } /* * the block is tree root or the block isn't in reference * counted tree. */ if (found_key.objectid == found_key.offset || is_cowonly_root(btrfs_ref_root(leaf, ref))) { ref_path->root_objectid = btrfs_ref_root(leaf, ref); ref_path->root_generation = btrfs_ref_generation(leaf, ref); if (level < 0) { /* special reference from the tree log */ ref_path->nodes[0] = found_key.offset; ref_path->current_level = 0; } ret = 0; goto out; } level++; BUG_ON(ref_path->nodes[level] != 0); ref_path->nodes[level] = found_key.offset; ref_path->current_level = level; /* * the reference was created in the running transaction, * no need to continue walking up. */ if (btrfs_ref_generation(leaf, ref) == trans->transid) { ref_path->root_objectid = btrfs_ref_root(leaf, ref); ref_path->root_generation = btrfs_ref_generation(leaf, ref); ret = 0; goto out; } btrfs_release_path(extent_root, path); cond_resched(); } /* reached max tree level, but no tree root found. */ BUG(); out: btrfs_free_path(path); return ret; } static int btrfs_first_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path, u64 extent_start) { memset(ref_path, 0, sizeof(*ref_path)); ref_path->extent_start = extent_start; return __next_ref_path(trans, extent_root, ref_path, 1); } static int btrfs_next_ref_path(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_ref_path *ref_path) { return __next_ref_path(trans, extent_root, ref_path, 0); } static noinline int get_new_locations(struct inode *reloc_inode, struct btrfs_key *extent_key, u64 offset, int no_fragment, struct disk_extent **extents, int *nr_extents) { struct btrfs_root *root = BTRFS_I(reloc_inode)->root; struct btrfs_path *path; struct btrfs_file_extent_item *fi; struct extent_buffer *leaf; struct disk_extent *exts = *extents; struct btrfs_key found_key; u64 cur_pos; u64 last_byte; u32 nritems; int nr = 0; int max = *nr_extents; int ret; WARN_ON(!no_fragment && *extents); if (!exts) { max = 1; exts = kmalloc(sizeof(*exts) * max, GFP_NOFS); if (!exts) return -ENOMEM; } path = btrfs_alloc_path(); BUG_ON(!path); cur_pos = extent_key->objectid - offset; last_byte = extent_key->objectid + extent_key->offset; ret = btrfs_lookup_file_extent(NULL, root, path, reloc_inode->i_ino, cur_pos, 0); if (ret < 0) goto out; if (ret > 0) { ret = -ENOENT; goto out; } while (1) { leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); if (path->slots[0] >= nritems) { ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; if (ret > 0) break; leaf = path->nodes[0]; } btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); if (found_key.offset != cur_pos || found_key.type != BTRFS_EXTENT_DATA_KEY || found_key.objectid != reloc_inode->i_ino) break; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) != BTRFS_FILE_EXTENT_REG || btrfs_file_extent_disk_bytenr(leaf, fi) == 0) break; if (nr == max) { struct disk_extent *old = exts; max *= 2; exts = kzalloc(sizeof(*exts) * max, GFP_NOFS); memcpy(exts, old, sizeof(*exts) * nr); if (old != *extents) kfree(old); } exts[nr].disk_bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); exts[nr].disk_num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); exts[nr].offset = btrfs_file_extent_offset(leaf, fi); exts[nr].num_bytes = btrfs_file_extent_num_bytes(leaf, fi); exts[nr].ram_bytes = btrfs_file_extent_ram_bytes(leaf, fi); exts[nr].compression = btrfs_file_extent_compression(leaf, fi); exts[nr].encryption = btrfs_file_extent_encryption(leaf, fi); exts[nr].other_encoding = btrfs_file_extent_other_encoding(leaf, fi); BUG_ON(exts[nr].offset > 0); BUG_ON(exts[nr].compression || exts[nr].encryption); BUG_ON(exts[nr].num_bytes != exts[nr].disk_num_bytes); cur_pos += exts[nr].num_bytes; nr++; if (cur_pos + offset >= last_byte) break; if (no_fragment) { ret = 1; goto out; } path->slots[0]++; } BUG_ON(cur_pos + offset > last_byte); if (cur_pos + offset < last_byte) { ret = -ENOENT; goto out; } ret = 0; out: btrfs_free_path(path); if (ret) { if (exts != *extents) kfree(exts); } else { *extents = exts; *nr_extents = nr; } return ret; } static noinline int replace_one_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *extent_key, struct btrfs_key *leaf_key, struct btrfs_ref_path *ref_path, struct disk_extent *new_extents, int nr_extents) { struct extent_buffer *leaf; struct btrfs_file_extent_item *fi; struct inode *inode = NULL; struct btrfs_key key; u64 lock_start = 0; u64 lock_end = 0; u64 num_bytes; u64 ext_offset; u64 search_end = (u64)-1; u32 nritems; int nr_scaned = 0; int extent_locked = 0; int extent_type; int ret; memcpy(&key, leaf_key, sizeof(key)); if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { if (key.objectid < ref_path->owner_objectid || (key.objectid == ref_path->owner_objectid && key.type < BTRFS_EXTENT_DATA_KEY)) { key.objectid = ref_path->owner_objectid; key.type = BTRFS_EXTENT_DATA_KEY; key.offset = 0; } } while (1) { ret = btrfs_search_slot(trans, root, &key, path, 0, 1); if (ret < 0) goto out; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); next: if (extent_locked && ret > 0) { /* * the file extent item was modified by someone * before the extent got locked. */ unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); extent_locked = 0; } if (path->slots[0] >= nritems) { if (++nr_scaned > 2) break; BUG_ON(extent_locked); ret = btrfs_next_leaf(root, path); if (ret < 0) goto out; if (ret > 0) break; leaf = path->nodes[0]; nritems = btrfs_header_nritems(leaf); } btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS) { if ((key.objectid > ref_path->owner_objectid) || (key.objectid == ref_path->owner_objectid && key.type > BTRFS_EXTENT_DATA_KEY) || key.offset >= search_end) break; } if (inode && key.objectid != inode->i_ino) { BUG_ON(extent_locked); btrfs_release_path(root, path); mutex_unlock(&inode->i_mutex); iput(inode); inode = NULL; continue; } if (key.type != BTRFS_EXTENT_DATA_KEY) { path->slots[0]++; ret = 1; goto next; } fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); extent_type = btrfs_file_extent_type(leaf, fi); if ((extent_type != BTRFS_FILE_EXTENT_REG && extent_type != BTRFS_FILE_EXTENT_PREALLOC) || (btrfs_file_extent_disk_bytenr(leaf, fi) != extent_key->objectid)) { path->slots[0]++; ret = 1; goto next; } num_bytes = btrfs_file_extent_num_bytes(leaf, fi); ext_offset = btrfs_file_extent_offset(leaf, fi); if (search_end == (u64)-1) { search_end = key.offset - ext_offset + btrfs_file_extent_ram_bytes(leaf, fi); } if (!extent_locked) { lock_start = key.offset; lock_end = lock_start + num_bytes - 1; } else { if (lock_start > key.offset || lock_end + 1 < key.offset + num_bytes) { unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); extent_locked = 0; } } if (!inode) { btrfs_release_path(root, path); inode = btrfs_iget_locked(root->fs_info->sb, key.objectid, root); if (inode->i_state & I_NEW) { BTRFS_I(inode)->root = root; BTRFS_I(inode)->location.objectid = key.objectid; BTRFS_I(inode)->location.type = BTRFS_INODE_ITEM_KEY; BTRFS_I(inode)->location.offset = 0; btrfs_read_locked_inode(inode); unlock_new_inode(inode); } /* * some code call btrfs_commit_transaction while * holding the i_mutex, so we can't use mutex_lock * here. */ if (is_bad_inode(inode) || !mutex_trylock(&inode->i_mutex)) { iput(inode); inode = NULL; key.offset = (u64)-1; goto skip; } } if (!extent_locked) { struct btrfs_ordered_extent *ordered; btrfs_release_path(root, path); lock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); ordered = btrfs_lookup_first_ordered_extent(inode, lock_end); if (ordered && ordered->file_offset <= lock_end && ordered->file_offset + ordered->len > lock_start) { unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); btrfs_start_ordered_extent(inode, ordered, 1); btrfs_put_ordered_extent(ordered); key.offset += num_bytes; goto skip; } if (ordered) btrfs_put_ordered_extent(ordered); extent_locked = 1; continue; } if (nr_extents == 1) { /* update extent pointer in place */ btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extents[0].disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extents[0].disk_num_bytes); btrfs_mark_buffer_dirty(leaf); btrfs_drop_extent_cache(inode, key.offset, key.offset + num_bytes - 1, 0); ret = btrfs_inc_extent_ref(trans, root, new_extents[0].disk_bytenr, new_extents[0].disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); ret = btrfs_free_extent(trans, root, extent_key->objectid, extent_key->offset, leaf->start, btrfs_header_owner(leaf), btrfs_header_generation(leaf), key.objectid, 0); BUG_ON(ret); btrfs_release_path(root, path); key.offset += num_bytes; } else { BUG_ON(1); #if 0 u64 alloc_hint; u64 extent_len; int i; /* * drop old extent pointer at first, then insert the * new pointers one bye one */ btrfs_release_path(root, path); ret = btrfs_drop_extents(trans, root, inode, key.offset, key.offset + num_bytes, key.offset, &alloc_hint); BUG_ON(ret); for (i = 0; i < nr_extents; i++) { if (ext_offset >= new_extents[i].num_bytes) { ext_offset -= new_extents[i].num_bytes; continue; } extent_len = min(new_extents[i].num_bytes - ext_offset, num_bytes); ret = btrfs_insert_empty_item(trans, root, path, &key, sizeof(*fi)); BUG_ON(ret); leaf = path->nodes[0]; fi = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_file_extent_item); btrfs_set_file_extent_generation(leaf, fi, trans->transid); btrfs_set_file_extent_type(leaf, fi, BTRFS_FILE_EXTENT_REG); btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extents[i].disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extents[i].disk_num_bytes); btrfs_set_file_extent_ram_bytes(leaf, fi, new_extents[i].ram_bytes); btrfs_set_file_extent_compression(leaf, fi, new_extents[i].compression); btrfs_set_file_extent_encryption(leaf, fi, new_extents[i].encryption); btrfs_set_file_extent_other_encoding(leaf, fi, new_extents[i].other_encoding); btrfs_set_file_extent_num_bytes(leaf, fi, extent_len); ext_offset += new_extents[i].offset; btrfs_set_file_extent_offset(leaf, fi, ext_offset); btrfs_mark_buffer_dirty(leaf); btrfs_drop_extent_cache(inode, key.offset, key.offset + extent_len - 1, 0); ret = btrfs_inc_extent_ref(trans, root, new_extents[i].disk_bytenr, new_extents[i].disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); btrfs_release_path(root, path); inode_add_bytes(inode, extent_len); ext_offset = 0; num_bytes -= extent_len; key.offset += extent_len; if (num_bytes == 0) break; } BUG_ON(i >= nr_extents); #endif } if (extent_locked) { unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); extent_locked = 0; } skip: if (ref_path->owner_objectid != BTRFS_MULTIPLE_OBJECTIDS && key.offset >= search_end) break; cond_resched(); } ret = 0; out: btrfs_release_path(root, path); if (inode) { mutex_unlock(&inode->i_mutex); if (extent_locked) { unlock_extent(&BTRFS_I(inode)->io_tree, lock_start, lock_end, GFP_NOFS); } iput(inode); } return ret; } int btrfs_reloc_tree_cache_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *buf, u64 orig_start) { int level; int ret; BUG_ON(btrfs_header_generation(buf) != trans->transid); BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); level = btrfs_header_level(buf); if (level == 0) { struct btrfs_leaf_ref *ref; struct btrfs_leaf_ref *orig_ref; orig_ref = btrfs_lookup_leaf_ref(root, orig_start); if (!orig_ref) return -ENOENT; ref = btrfs_alloc_leaf_ref(root, orig_ref->nritems); if (!ref) { btrfs_free_leaf_ref(root, orig_ref); return -ENOMEM; } ref->nritems = orig_ref->nritems; memcpy(ref->extents, orig_ref->extents, sizeof(ref->extents[0]) * ref->nritems); btrfs_free_leaf_ref(root, orig_ref); ref->root_gen = trans->transid; ref->bytenr = buf->start; ref->owner = btrfs_header_owner(buf); ref->generation = btrfs_header_generation(buf); ret = btrfs_add_leaf_ref(root, ref, 0); WARN_ON(ret); btrfs_free_leaf_ref(root, ref); } return 0; } static noinline int invalidate_extent_cache(struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_block_group_cache *group, struct btrfs_root *target_root) { struct btrfs_key key; struct inode *inode = NULL; struct btrfs_file_extent_item *fi; struct extent_state *cached_state = NULL; u64 num_bytes; u64 skip_objectid = 0; u32 nritems; u32 i; nritems = btrfs_header_nritems(leaf); for (i = 0; i < nritems; i++) { btrfs_item_key_to_cpu(leaf, &key, i); if (key.objectid == skip_objectid || key.type != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; if (btrfs_file_extent_disk_bytenr(leaf, fi) == 0) continue; if (!inode || inode->i_ino != key.objectid) { iput(inode); inode = btrfs_ilookup(target_root->fs_info->sb, key.objectid, target_root, 1); } if (!inode) { skip_objectid = key.objectid; continue; } num_bytes = btrfs_file_extent_num_bytes(leaf, fi); lock_extent_bits(&BTRFS_I(inode)->io_tree, key.offset, key.offset + num_bytes - 1, 0, &cached_state, GFP_NOFS); btrfs_drop_extent_cache(inode, key.offset, key.offset + num_bytes - 1, 1); unlock_extent_cached(&BTRFS_I(inode)->io_tree, key.offset, key.offset + num_bytes - 1, &cached_state, GFP_NOFS); cond_resched(); } iput(inode); return 0; } static noinline int replace_extents_in_leaf(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct extent_buffer *leaf, struct btrfs_block_group_cache *group, struct inode *reloc_inode) { struct btrfs_key key; struct btrfs_key extent_key; struct btrfs_file_extent_item *fi; struct btrfs_leaf_ref *ref; struct disk_extent *new_extent; u64 bytenr; u64 num_bytes; u32 nritems; u32 i; int ext_index; int nr_extent; int ret; new_extent = kmalloc(sizeof(*new_extent), GFP_NOFS); BUG_ON(!new_extent); ref = btrfs_lookup_leaf_ref(root, leaf->start); BUG_ON(!ref); ext_index = -1; nritems = btrfs_header_nritems(leaf); for (i = 0; i < nritems; i++) { btrfs_item_key_to_cpu(leaf, &key, i); if (btrfs_key_type(&key) != BTRFS_EXTENT_DATA_KEY) continue; fi = btrfs_item_ptr(leaf, i, struct btrfs_file_extent_item); if (btrfs_file_extent_type(leaf, fi) == BTRFS_FILE_EXTENT_INLINE) continue; bytenr = btrfs_file_extent_disk_bytenr(leaf, fi); num_bytes = btrfs_file_extent_disk_num_bytes(leaf, fi); if (bytenr == 0) continue; ext_index++; if (bytenr >= group->key.objectid + group->key.offset || bytenr + num_bytes <= group->key.objectid) continue; extent_key.objectid = bytenr; extent_key.offset = num_bytes; extent_key.type = BTRFS_EXTENT_ITEM_KEY; nr_extent = 1; ret = get_new_locations(reloc_inode, &extent_key, group->key.objectid, 1, &new_extent, &nr_extent); if (ret > 0) continue; BUG_ON(ret < 0); BUG_ON(ref->extents[ext_index].bytenr != bytenr); BUG_ON(ref->extents[ext_index].num_bytes != num_bytes); ref->extents[ext_index].bytenr = new_extent->disk_bytenr; ref->extents[ext_index].num_bytes = new_extent->disk_num_bytes; btrfs_set_file_extent_disk_bytenr(leaf, fi, new_extent->disk_bytenr); btrfs_set_file_extent_disk_num_bytes(leaf, fi, new_extent->disk_num_bytes); btrfs_mark_buffer_dirty(leaf); ret = btrfs_inc_extent_ref(trans, root, new_extent->disk_bytenr, new_extent->disk_num_bytes, leaf->start, root->root_key.objectid, trans->transid, key.objectid); BUG_ON(ret); ret = btrfs_free_extent(trans, root, bytenr, num_bytes, leaf->start, btrfs_header_owner(leaf), btrfs_header_generation(leaf), key.objectid, 0); BUG_ON(ret); cond_resched(); } kfree(new_extent); BUG_ON(ext_index + 1 != ref->nritems); btrfs_free_leaf_ref(root, ref); return 0; } int btrfs_free_reloc_root(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_root *reloc_root; int ret; if (root->reloc_root) { reloc_root = root->reloc_root; root->reloc_root = NULL; list_add(&reloc_root->dead_list, &root->fs_info->dead_reloc_roots); btrfs_set_root_bytenr(&reloc_root->root_item, reloc_root->node->start); btrfs_set_root_level(&root->root_item, btrfs_header_level(reloc_root->node)); memset(&reloc_root->root_item.drop_progress, 0, sizeof(struct btrfs_disk_key)); reloc_root->root_item.drop_level = 0; ret = btrfs_update_root(trans, root->fs_info->tree_root, &reloc_root->root_key, &reloc_root->root_item); BUG_ON(ret); } return 0; } int btrfs_drop_dead_reloc_roots(struct btrfs_root *root) { struct btrfs_trans_handle *trans; struct btrfs_root *reloc_root; struct btrfs_root *prev_root = NULL; struct list_head dead_roots; int ret; unsigned long nr; INIT_LIST_HEAD(&dead_roots); list_splice_init(&root->fs_info->dead_reloc_roots, &dead_roots); while (!list_empty(&dead_roots)) { reloc_root = list_entry(dead_roots.prev, struct btrfs_root, dead_list); list_del_init(&reloc_root->dead_list); BUG_ON(reloc_root->commit_root != NULL); while (1) { trans = btrfs_join_transaction(root, 1); BUG_ON(!trans); mutex_lock(&root->fs_info->drop_mutex); ret = btrfs_drop_snapshot(trans, reloc_root); if (ret != -EAGAIN) break; mutex_unlock(&root->fs_info->drop_mutex); nr = trans->blocks_used; ret = btrfs_end_transaction(trans, root); BUG_ON(ret); btrfs_btree_balance_dirty(root, nr); } free_extent_buffer(reloc_root->node); ret = btrfs_del_root(trans, root->fs_info->tree_root, &reloc_root->root_key); BUG_ON(ret); mutex_unlock(&root->fs_info->drop_mutex); nr = trans->blocks_used; ret = btrfs_end_transaction(trans, root); BUG_ON(ret); btrfs_btree_balance_dirty(root, nr); kfree(prev_root); prev_root = reloc_root; } if (prev_root) { btrfs_remove_leaf_refs(prev_root, (u64)-1, 0); kfree(prev_root); } return 0; } int btrfs_add_dead_reloc_root(struct btrfs_root *root) { list_add(&root->dead_list, &root->fs_info->dead_reloc_roots); return 0; } int btrfs_cleanup_reloc_trees(struct btrfs_root *root) { struct btrfs_root *reloc_root; struct btrfs_trans_handle *trans; struct btrfs_key location; int found; int ret; mutex_lock(&root->fs_info->tree_reloc_mutex); ret = btrfs_find_dead_roots(root, BTRFS_TREE_RELOC_OBJECTID, NULL); BUG_ON(ret); found = !list_empty(&root->fs_info->dead_reloc_roots); mutex_unlock(&root->fs_info->tree_reloc_mutex); if (found) { trans = btrfs_start_transaction(root, 1); BUG_ON(!trans); ret = btrfs_commit_transaction(trans, root); BUG_ON(ret); } location.objectid = BTRFS_DATA_RELOC_TREE_OBJECTID; location.offset = (u64)-1; location.type = BTRFS_ROOT_ITEM_KEY; reloc_root = btrfs_read_fs_root_no_name(root->fs_info, &location); BUG_ON(!reloc_root); btrfs_orphan_cleanup(reloc_root); return 0; } static noinline int init_reloc_tree(struct btrfs_trans_handle *trans, struct btrfs_root *root) { struct btrfs_root *reloc_root; struct extent_buffer *eb; struct btrfs_root_item *root_item; struct btrfs_key root_key; int ret; BUG_ON(!root->ref_cows); if (root->reloc_root) return 0; root_item = kmalloc(sizeof(*root_item), GFP_NOFS); BUG_ON(!root_item); ret = btrfs_copy_root(trans, root, root->commit_root, &eb, BTRFS_TREE_RELOC_OBJECTID); BUG_ON(ret); root_key.objectid = BTRFS_TREE_RELOC_OBJECTID; root_key.offset = root->root_key.objectid; root_key.type = BTRFS_ROOT_ITEM_KEY; memcpy(root_item, &root->root_item, sizeof(root_item)); btrfs_set_root_refs(root_item, 0); btrfs_set_root_bytenr(root_item, eb->start); btrfs_set_root_level(root_item, btrfs_header_level(eb)); btrfs_set_root_generation(root_item, trans->transid); btrfs_tree_unlock(eb); free_extent_buffer(eb); ret = btrfs_insert_root(trans, root->fs_info->tree_root, &root_key, root_item); BUG_ON(ret); kfree(root_item); reloc_root = btrfs_read_fs_root_no_radix(root->fs_info->tree_root, &root_key); BUG_ON(!reloc_root); reloc_root->last_trans = trans->transid; reloc_root->commit_root = NULL; reloc_root->ref_tree = &root->fs_info->reloc_ref_tree; root->reloc_root = reloc_root; return 0; } /* * Core function of space balance. * * The idea is using reloc trees to relocate tree blocks in reference * counted roots. There is one reloc tree for each subvol, and all * reloc trees share same root key objectid. Reloc trees are snapshots * of the latest committed roots of subvols (root->commit_root). * * To relocate a tree block referenced by a subvol, there are two steps. * COW the block through subvol's reloc tree, then update block pointer * in the subvol to point to the new block. Since all reloc trees share * same root key objectid, doing special handing for tree blocks owned * by them is easy. Once a tree block has been COWed in one reloc tree, * we can use the resulting new block directly when the same block is * required to COW again through other reloc trees. By this way, relocated * tree blocks are shared between reloc trees, so they are also shared * between subvols. */ static noinline int relocate_one_path(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *first_key, struct btrfs_ref_path *ref_path, struct btrfs_block_group_cache *group, struct inode *reloc_inode) { struct btrfs_root *reloc_root; struct extent_buffer *eb = NULL; struct btrfs_key *keys; u64 *nodes; int level; int shared_level; int lowest_level = 0; int ret; if (ref_path->owner_objectid < BTRFS_FIRST_FREE_OBJECTID) lowest_level = ref_path->owner_objectid; if (!root->ref_cows) { path->lowest_level = lowest_level; ret = btrfs_search_slot(trans, root, first_key, path, 0, 1); BUG_ON(ret < 0); path->lowest_level = 0; btrfs_release_path(root, path); return 0; } mutex_lock(&root->fs_info->tree_reloc_mutex); ret = init_reloc_tree(trans, root); BUG_ON(ret); reloc_root = root->reloc_root; shared_level = ref_path->shared_level; ref_path->shared_level = BTRFS_MAX_LEVEL - 1; keys = ref_path->node_keys; nodes = ref_path->new_nodes; memset(&keys[shared_level + 1], 0, sizeof(*keys) * (BTRFS_MAX_LEVEL - shared_level - 1)); memset(&nodes[shared_level + 1], 0, sizeof(*nodes) * (BTRFS_MAX_LEVEL - shared_level - 1)); if (nodes[lowest_level] == 0) { path->lowest_level = lowest_level; ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 1); BUG_ON(ret); for (level = lowest_level; level < BTRFS_MAX_LEVEL; level++) { eb = path->nodes[level]; if (!eb || eb == reloc_root->node) break; nodes[level] = eb->start; if (level == 0) btrfs_item_key_to_cpu(eb, &keys[level], 0); else btrfs_node_key_to_cpu(eb, &keys[level], 0); } if (nodes[0] && ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { eb = path->nodes[0]; ret = replace_extents_in_leaf(trans, reloc_root, eb, group, reloc_inode); BUG_ON(ret); } btrfs_release_path(reloc_root, path); } else { ret = btrfs_merge_path(trans, reloc_root, keys, nodes, lowest_level); BUG_ON(ret); } /* * replace tree blocks in the fs tree with tree blocks in * the reloc tree. */ ret = btrfs_merge_path(trans, root, keys, nodes, lowest_level); BUG_ON(ret < 0); if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { ret = btrfs_search_slot(trans, reloc_root, first_key, path, 0, 0); BUG_ON(ret); extent_buffer_get(path->nodes[0]); eb = path->nodes[0]; btrfs_release_path(reloc_root, path); ret = invalidate_extent_cache(reloc_root, eb, group, root); BUG_ON(ret); free_extent_buffer(eb); } mutex_unlock(&root->fs_info->tree_reloc_mutex); path->lowest_level = 0; return 0; } static noinline int relocate_tree_block(struct btrfs_trans_handle *trans, struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *first_key, struct btrfs_ref_path *ref_path) { int ret; ret = relocate_one_path(trans, root, path, first_key, ref_path, NULL, NULL); BUG_ON(ret); return 0; } static noinline int del_extent_zero(struct btrfs_trans_handle *trans, struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key) { int ret; ret = btrfs_search_slot(trans, extent_root, extent_key, path, -1, 1); if (ret) goto out; ret = btrfs_del_item(trans, extent_root, path); out: btrfs_release_path(extent_root, path); return ret; } static noinline struct btrfs_root *read_ref_root(struct btrfs_fs_info *fs_info, struct btrfs_ref_path *ref_path) { struct btrfs_key root_key; root_key.objectid = ref_path->root_objectid; root_key.type = BTRFS_ROOT_ITEM_KEY; if (is_cowonly_root(ref_path->root_objectid)) root_key.offset = 0; else root_key.offset = (u64)-1; return btrfs_read_fs_root_no_name(fs_info, &root_key); } static noinline int relocate_one_extent(struct btrfs_root *extent_root, struct btrfs_path *path, struct btrfs_key *extent_key, struct btrfs_block_group_cache *group, struct inode *reloc_inode, int pass) { struct btrfs_trans_handle *trans; struct btrfs_root *found_root; struct btrfs_ref_path *ref_path = NULL; struct disk_extent *new_extents = NULL; int nr_extents = 0; int loops; int ret; int level; struct btrfs_key first_key; u64 prev_block = 0; trans = btrfs_start_transaction(extent_root, 1); BUG_ON(!trans); if (extent_key->objectid == 0) { ret = del_extent_zero(trans, extent_root, path, extent_key); goto out; } ref_path = kmalloc(sizeof(*ref_path), GFP_NOFS); if (!ref_path) { ret = -ENOMEM; goto out; } for (loops = 0; ; loops++) { if (loops == 0) { ret = btrfs_first_ref_path(trans, extent_root, ref_path, extent_key->objectid); } else { ret = btrfs_next_ref_path(trans, extent_root, ref_path); } if (ret < 0) goto out; if (ret > 0) break; if (ref_path->root_objectid == BTRFS_TREE_LOG_OBJECTID || ref_path->root_objectid == BTRFS_TREE_RELOC_OBJECTID) continue; found_root = read_ref_root(extent_root->fs_info, ref_path); BUG_ON(!found_root); /* * for reference counted tree, only process reference paths * rooted at the latest committed root. */ if (found_root->ref_cows && ref_path->root_generation != found_root->root_key.offset) continue; if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { if (pass == 0) { /* * copy data extents to new locations */ u64 group_start = group->key.objectid; ret = relocate_data_extent(reloc_inode, extent_key, group_start); if (ret < 0) goto out; break; } level = 0; } else { level = ref_path->owner_objectid; } if (prev_block != ref_path->nodes[level]) { struct extent_buffer *eb; u64 block_start = ref_path->nodes[level]; u64 block_size = btrfs_level_size(found_root, level); eb = read_tree_block(found_root, block_start, block_size, 0); btrfs_tree_lock(eb); BUG_ON(level != btrfs_header_level(eb)); if (level == 0) btrfs_item_key_to_cpu(eb, &first_key, 0); else btrfs_node_key_to_cpu(eb, &first_key, 0); btrfs_tree_unlock(eb); free_extent_buffer(eb); prev_block = block_start; } mutex_lock(&extent_root->fs_info->trans_mutex); btrfs_record_root_in_trans(found_root); mutex_unlock(&extent_root->fs_info->trans_mutex); if (ref_path->owner_objectid >= BTRFS_FIRST_FREE_OBJECTID) { /* * try to update data extent references while * keeping metadata shared between snapshots. */ if (pass == 1) { ret = relocate_one_path(trans, found_root, path, &first_key, ref_path, group, reloc_inode); if (ret < 0) goto out; continue; } /* * use fallback method to process the remaining * references. */ if (!new_extents) { u64 group_start = group->key.objectid; new_extents = kmalloc(sizeof(*new_extents), GFP_NOFS); nr_extents = 1; ret = get_new_locations(reloc_inode, extent_key, group_start, 1, &new_extents, &nr_extents); if (ret) goto out; } ret = replace_one_extent(trans, found_root, path, extent_key, &first_key, ref_path, new_extents, nr_extents); } else { ret = relocate_tree_block(trans, found_root, path, &first_key, ref_path); } if (ret < 0) goto out; } ret = 0; out: btrfs_end_transaction(trans, extent_root); kfree(new_extents); kfree(ref_path); return ret; } #endif static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) { u64 num_devices; u64 stripped = BTRFS_BLOCK_GROUP_RAID0 | BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; num_devices = root->fs_info->fs_devices->rw_devices; if (num_devices == 1) { stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* turn raid0 into single device chunks */ if (flags & BTRFS_BLOCK_GROUP_RAID0) return stripped; /* turn mirroring into duplication */ if (flags & (BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10)) return stripped | BTRFS_BLOCK_GROUP_DUP; return flags; } else { /* they already had raid on here, just return */ if (flags & stripped) return flags; stripped |= BTRFS_BLOCK_GROUP_DUP; stripped = flags & ~stripped; /* switch duplicated blocks with raid1 */ if (flags & BTRFS_BLOCK_GROUP_DUP) return stripped | BTRFS_BLOCK_GROUP_RAID1; /* turn single device chunks into raid0 */ return stripped | BTRFS_BLOCK_GROUP_RAID0; } return flags; } static int __alloc_chunk_for_shrink(struct btrfs_root *root, struct btrfs_block_group_cache *shrink_block_group, int force) { struct btrfs_trans_handle *trans; u64 new_alloc_flags; u64 calc; spin_lock(&shrink_block_group->lock); if (btrfs_block_group_used(&shrink_block_group->item) + shrink_block_group->reserved > 0) { spin_unlock(&shrink_block_group->lock); trans = btrfs_start_transaction(root, 1); spin_lock(&shrink_block_group->lock); new_alloc_flags = update_block_group_flags(root, shrink_block_group->flags); if (new_alloc_flags != shrink_block_group->flags) { calc = btrfs_block_group_used(&shrink_block_group->item); } else { calc = shrink_block_group->key.offset; } spin_unlock(&shrink_block_group->lock); do_chunk_alloc(trans, root->fs_info->extent_root, calc + 2 * 1024 * 1024, new_alloc_flags, force); btrfs_end_transaction(trans, root); } else spin_unlock(&shrink_block_group->lock); return 0; } int btrfs_prepare_block_group_relocation(struct btrfs_root *root, struct btrfs_block_group_cache *group) { __alloc_chunk_for_shrink(root, group, 1); set_block_group_readonly(group); return 0; } /* * checks to see if its even possible to relocate this block group. * * @return - -1 if it's not a good idea to relocate this block group, 0 if its * ok to go ahead and try. */ int btrfs_can_relocate(struct btrfs_root *root, u64 bytenr) { struct btrfs_block_group_cache *block_group; struct btrfs_space_info *space_info; struct btrfs_fs_devices *fs_devices = root->fs_info->fs_devices; struct btrfs_device *device; int full = 0; int ret = 0; block_group = btrfs_lookup_block_group(root->fs_info, bytenr); /* odd, couldn't find the block group, leave it alone */ if (!block_group) return -1; /* no bytes used, we're good */ if (!btrfs_block_group_used(&block_group->item)) goto out; space_info = block_group->space_info; spin_lock(&space_info->lock); full = space_info->full; /* * if this is the last block group we have in this space, we can't * relocate it unless we're able to allocate a new chunk below. * * Otherwise, we need to make sure we have room in the space to handle * all of the extents from this block group. If we can, we're good */ if ((space_info->total_bytes != block_group->key.offset) && (space_info->bytes_used + space_info->bytes_reserved + space_info->bytes_pinned + space_info->bytes_readonly + btrfs_block_group_used(&block_group->item) < space_info->total_bytes)) { spin_unlock(&space_info->lock); goto out; } spin_unlock(&space_info->lock); /* * ok we don't have enough space, but maybe we have free space on our * devices to allocate new chunks for relocation, so loop through our * alloc devices and guess if we have enough space. However, if we * were marked as full, then we know there aren't enough chunks, and we * can just return. */ ret = -1; if (full) goto out; mutex_lock(&root->fs_info->chunk_mutex); list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { u64 min_free = btrfs_block_group_used(&block_group->item); u64 dev_offset, max_avail; /* * check to make sure we can actually find a chunk with enough * space to fit our block group in. */ if (device->total_bytes > device->bytes_used + min_free) { ret = find_free_dev_extent(NULL, device, min_free, &dev_offset, &max_avail); if (!ret) break; ret = -1; } } mutex_unlock(&root->fs_info->chunk_mutex); out: btrfs_put_block_group(block_group); return ret; } static int find_first_block_group(struct btrfs_root *root, struct btrfs_path *path, struct btrfs_key *key) { int ret = 0; struct btrfs_key found_key; struct extent_buffer *leaf; int slot; ret = btrfs_search_slot(NULL, root, key, path, 0, 0); if (ret < 0) goto out; while (1) { slot = path->slots[0]; leaf = path->nodes[0]; if (slot >= btrfs_header_nritems(leaf)) { ret = btrfs_next_leaf(root, path); if (ret == 0) continue; if (ret < 0) goto out; break; } btrfs_item_key_to_cpu(leaf, &found_key, slot); if (found_key.objectid >= key->objectid && found_key.type == BTRFS_BLOCK_GROUP_ITEM_KEY) { ret = 0; goto out; } path->slots[0]++; } out: return ret; } 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->extent_commit_sem); while (!list_empty(&info->caching_block_groups)) { caching_ctl = list_entry(info->caching_block_groups.next, struct btrfs_caching_control, list); list_del(&caching_ctl->list); put_caching_control(caching_ctl); } up_write(&info->extent_commit_sem); 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); spin_unlock(&info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); list_del(&block_group->list); up_write(&block_group->space_info->groups_sem); if (block_group->cached == BTRFS_CACHE_STARTED) wait_block_group_cache_done(block_group); btrfs_remove_free_space_cache(block_group); btrfs_put_block_group(block_group); spin_lock(&info->block_group_cache_lock); } spin_unlock(&info->block_group_cache_lock); /* now that all the block groups are freed, go through and * free all the space_info structs. This is only called during * the final stages of unmount, and so we know nobody is * using them. We call synchronize_rcu() once before we start, * just to be on the safe side. */ synchronize_rcu(); while(!list_empty(&info->space_info)) { space_info = list_entry(info->space_info.next, struct btrfs_space_info, list); list_del(&space_info->list); kfree(space_info); } return 0; } int btrfs_read_block_groups(struct btrfs_root *root) { struct btrfs_path *path; int ret; struct btrfs_block_group_cache *cache; struct btrfs_fs_info *info = root->fs_info; struct btrfs_space_info *space_info; struct btrfs_key key; struct btrfs_key found_key; struct extent_buffer *leaf; root = info->extent_root; key.objectid = 0; key.offset = 0; btrfs_set_key_type(&key, BTRFS_BLOCK_GROUP_ITEM_KEY); path = btrfs_alloc_path(); if (!path) return -ENOMEM; while (1) { ret = find_first_block_group(root, path, &key); if (ret > 0) { ret = 0; goto error; } if (ret != 0) goto error; leaf = path->nodes[0]; btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); cache = kzalloc(sizeof(*cache), GFP_NOFS); if (!cache) { ret = -ENOMEM; break; } atomic_set(&cache->count, 1); spin_lock_init(&cache->lock); spin_lock_init(&cache->tree_lock); cache->fs_info = info; INIT_LIST_HEAD(&cache->list); INIT_LIST_HEAD(&cache->cluster_list); /* * we only want to have 32k of ram per block group for keeping * track of free space, and if we pass 1/2 of that we want to * start converting things over to using bitmaps */ cache->extents_thresh = ((1024 * 32) / 2) / sizeof(struct btrfs_free_space); read_extent_buffer(leaf, &cache->item, btrfs_item_ptr_offset(leaf, path->slots[0]), sizeof(cache->item)); memcpy(&cache->key, &found_key, sizeof(found_key)); key.objectid = found_key.objectid + found_key.offset; btrfs_release_path(root, path); cache->flags = btrfs_block_group_flags(&cache->item); cache->sectorsize = root->sectorsize; /* * check for two cases, either we are full, and therefore * don't need to bother with the caching work since we won't * find any space, or we are empty, and we can just add all * the space in and be done with it. This saves us _alot_ of * time, particularly in the full case. */ if (found_key.offset == btrfs_block_group_used(&cache->item)) { exclude_super_stripes(root, cache); cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; free_excluded_extents(root, cache); } else if (btrfs_block_group_used(&cache->item) == 0) { exclude_super_stripes(root, cache); cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; add_new_free_space(cache, root->fs_info, found_key.objectid, found_key.objectid + found_key.offset); free_excluded_extents(root, cache); } ret = update_space_info(info, cache->flags, found_key.offset, btrfs_block_group_used(&cache->item), &space_info); BUG_ON(ret); cache->space_info = space_info; spin_lock(&cache->space_info->lock); cache->space_info->bytes_super += cache->bytes_super; spin_unlock(&cache->space_info->lock); down_write(&space_info->groups_sem); list_add_tail(&cache->list, &space_info->block_groups); up_write(&space_info->groups_sem); ret = btrfs_add_block_group_cache(root->fs_info, cache); BUG_ON(ret); set_avail_alloc_bits(root->fs_info, cache->flags); if (btrfs_chunk_readonly(root, cache->key.objectid)) set_block_group_readonly(cache); } ret = 0; error: btrfs_free_path(path); return ret; } int btrfs_make_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 bytes_used, u64 type, u64 chunk_objectid, u64 chunk_offset, u64 size) { int ret; struct btrfs_root *extent_root; struct btrfs_block_group_cache *cache; extent_root = root->fs_info->extent_root; root->fs_info->last_trans_log_full_commit = trans->transid; cache = kzalloc(sizeof(*cache), GFP_NOFS); if (!cache) return -ENOMEM; cache->key.objectid = chunk_offset; cache->key.offset = size; cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; cache->sectorsize = root->sectorsize; /* * we only want to have 32k of ram per block group for keeping track * of free space, and if we pass 1/2 of that we want to start * converting things over to using bitmaps */ cache->extents_thresh = ((1024 * 32) / 2) / sizeof(struct btrfs_free_space); atomic_set(&cache->count, 1); spin_lock_init(&cache->lock); spin_lock_init(&cache->tree_lock); INIT_LIST_HEAD(&cache->list); INIT_LIST_HEAD(&cache->cluster_list); btrfs_set_block_group_used(&cache->item, bytes_used); btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); cache->flags = type; btrfs_set_block_group_flags(&cache->item, type); cache->last_byte_to_unpin = (u64)-1; cache->cached = BTRFS_CACHE_FINISHED; exclude_super_stripes(root, cache); add_new_free_space(cache, root->fs_info, chunk_offset, chunk_offset + size); free_excluded_extents(root, cache); ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, &cache->space_info); BUG_ON(ret); spin_lock(&cache->space_info->lock); cache->space_info->bytes_super += cache->bytes_super; spin_unlock(&cache->space_info->lock); down_write(&cache->space_info->groups_sem); list_add_tail(&cache->list, &cache->space_info->block_groups); up_write(&cache->space_info->groups_sem); ret = btrfs_add_block_group_cache(root->fs_info, cache); BUG_ON(ret); ret = btrfs_insert_item(trans, extent_root, &cache->key, &cache->item, sizeof(cache->item)); BUG_ON(ret); set_avail_alloc_bits(extent_root->fs_info, type); return 0; } int btrfs_remove_block_group(struct btrfs_trans_handle *trans, struct btrfs_root *root, u64 group_start) { struct btrfs_path *path; struct btrfs_block_group_cache *block_group; struct btrfs_free_cluster *cluster; struct btrfs_key key; int ret; root = root->fs_info->extent_root; block_group = btrfs_lookup_block_group(root->fs_info, group_start); BUG_ON(!block_group); BUG_ON(!block_group->ro); memcpy(&key, &block_group->key, sizeof(key)); /* make sure this block group isn't part of an allocation cluster */ cluster = &root->fs_info->data_alloc_cluster; spin_lock(&cluster->refill_lock); btrfs_return_cluster_to_free_space(block_group, cluster); spin_unlock(&cluster->refill_lock); /* * make sure this block group isn't part of a metadata * allocation cluster */ cluster = &root->fs_info->meta_alloc_cluster; spin_lock(&cluster->refill_lock); btrfs_return_cluster_to_free_space(block_group, cluster); spin_unlock(&cluster->refill_lock); path = btrfs_alloc_path(); BUG_ON(!path); spin_lock(&root->fs_info->block_group_cache_lock); rb_erase(&block_group->cache_node, &root->fs_info->block_group_cache_tree); spin_unlock(&root->fs_info->block_group_cache_lock); down_write(&block_group->space_info->groups_sem); /* * we must use list_del_init so people can check to see if they * are still on the list after taking the semaphore */ list_del_init(&block_group->list); up_write(&block_group->space_info->groups_sem); if (block_group->cached == BTRFS_CACHE_STARTED) wait_block_group_cache_done(block_group); btrfs_remove_free_space_cache(block_group); spin_lock(&block_group->space_info->lock); block_group->space_info->total_bytes -= block_group->key.offset; block_group->space_info->bytes_readonly -= block_group->key.offset; spin_unlock(&block_group->space_info->lock); btrfs_clear_space_info_full(root->fs_info); btrfs_put_block_group(block_group); btrfs_put_block_group(block_group); ret = btrfs_search_slot(trans, root, &key, path, -1, 1); if (ret > 0) ret = -EIO; if (ret < 0) goto out; ret = btrfs_del_item(trans, root, path); out: btrfs_free_path(path); return ret; }