diff options
Diffstat (limited to 'kernel/fs/btrfs/extent-tree.c')
| -rw-r--r-- | kernel/fs/btrfs/extent-tree.c | 10174 |
1 files changed, 10174 insertions, 0 deletions
diff --git a/kernel/fs/btrfs/extent-tree.c b/kernel/fs/btrfs/extent-tree.c new file mode 100644 index 000000000..0ec3acd14 --- /dev/null +++ b/kernel/fs/btrfs/extent-tree.c @@ -0,0 +1,10174 @@ +/* + * Copyright (C) 2007 Oracle. All rights reserved. + * + * This program is free software; you can redistribute it and/or + * modify it under the terms of the GNU General Public + * License v2 as published by the Free Software Foundation. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * General Public License for more details. + * + * You should have received a copy of the GNU General Public + * License along with this program; if not, write to the + * Free Software Foundation, Inc., 59 Temple Place - Suite 330, + * Boston, MA 021110-1307, USA. + */ +#include <linux/sched.h> +#include <linux/pagemap.h> +#include <linux/writeback.h> +#include <linux/blkdev.h> +#include <linux/sort.h> +#include <linux/rcupdate.h> +#include <linux/kthread.h> +#include <linux/slab.h> +#include <linux/ratelimit.h> +#include <linux/percpu_counter.h> +#include "hash.h" +#include "tree-log.h" +#include "disk-io.h" +#include "print-tree.h" +#include "volumes.h" +#include "raid56.h" +#include "locking.h" +#include "free-space-cache.h" +#include "math.h" +#include "sysfs.h" +#include "qgroup.h" + +#undef SCRAMBLE_DELAYED_REFS + +/* + * control flags for do_chunk_alloc's force field + * CHUNK_ALLOC_NO_FORCE means to only allocate a chunk + * if we really need one. + * + * CHUNK_ALLOC_LIMITED means to only try and allocate one + * if we have very few chunks already allocated. This is + * used as part of the clustering code to help make sure + * we have a good pool of storage to cluster in, without + * filling the FS with empty chunks + * + * CHUNK_ALLOC_FORCE means it must try to allocate one + * + */ +enum { + CHUNK_ALLOC_NO_FORCE = 0, + CHUNK_ALLOC_LIMITED = 1, + CHUNK_ALLOC_FORCE = 2, +}; + +/* + * Control how reservations are dealt with. + * + * RESERVE_FREE - freeing a reservation. + * RESERVE_ALLOC - allocating space and we need to update bytes_may_use for + * ENOSPC accounting + * RESERVE_ALLOC_NO_ACCOUNT - allocating space and we should not update + * bytes_may_use as the ENOSPC accounting is done elsewhere + */ +enum { + RESERVE_FREE = 0, + RESERVE_ALLOC = 1, + RESERVE_ALLOC_NO_ACCOUNT = 2, +}; + +static int update_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 num_bytes, int alloc); +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, + int no_quota); +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, + int no_quota); +static int do_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 flags, + int force); +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 int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache, + u64 num_bytes, int reserve, + int delalloc); +static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, + u64 num_bytes); +int btrfs_pin_extent(struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int reserved); + +static noinline int +block_group_cache_done(struct btrfs_block_group_cache *cache) +{ + smp_mb(); + return cache->cached == BTRFS_CACHE_FINISHED || + cache->cached == BTRFS_CACHE_ERROR; +} + +static int block_group_bits(struct btrfs_block_group_cache *cache, u64 bits) +{ + return (cache->flags & bits) == bits; +} + +static 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)) { + WARN_ON(cache->pinned > 0); + WARN_ON(cache->reserved > 0); + kfree(cache->free_space_ctl); + 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); + + if (info->first_logical_byte > block_group->key.objectid) + info->first_logical_byte = block_group->key.objectid; + + spin_unlock(&info->block_group_cache_lock); + + return 0; +} + +/* + * 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); + if (bytenr == 0 && info->first_logical_byte > ret->key.objectid) + info->first_logical_byte = ret->key.objectid; + } + 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); + if (ret) + return 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); + if (ret) + return ret; + + while (nr--) { + u64 start, len; + + if (logical[nr] > cache->key.objectid + + cache->key.offset) + continue; + + if (logical[nr] + stripe_len <= cache->key.objectid) + continue; + + start = logical[nr]; + if (start < cache->key.objectid) { + start = cache->key.objectid; + len = (logical[nr] + stripe_len) - start; + } else { + len = min_t(u64, stripe_len, + cache->key.objectid + + cache->key.offset - start); + } + + cache->bytes_super += len; + ret = add_excluded_extent(root, start, len); + if (ret) { + kfree(logical); + return 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->caching_ctl) { + 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, + NULL); + if (ret) + break; + + if (extent_start <= start) { + start = extent_end + 1; + } else if (extent_start > start && extent_start < end) { + size = extent_start - start; + total_added += size; + ret = btrfs_add_free_space(block_group, start, + size); + BUG_ON(ret); /* -ENOMEM or logic error */ + start = extent_end + 1; + } else { + break; + } + } + + if (start < end) { + size = end - start; + total_added += size; + ret = btrfs_add_free_space(block_group, start, size); + BUG_ON(ret); /* -ENOMEM or logic error */ + } + + return total_added; +} + +static noinline void caching_thread(struct btrfs_work *work) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_fs_info *fs_info; + struct btrfs_caching_control *caching_ctl; + struct btrfs_root *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 = -ENOMEM; + + caching_ctl = container_of(work, struct btrfs_caching_control, work); + block_group = caching_ctl->block_group; + fs_info = block_group->fs_info; + extent_root = fs_info->extent_root; + + path = btrfs_alloc_path(); + if (!path) + goto out; + + 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 = 1; + + 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->commit_root_sem); + +next: + 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) { + if (btrfs_fs_closing(fs_info) > 1) { + last = (u64)-1; + break; + } + + if (path->slots[0] < nritems) { + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + } else { + ret = find_next_key(path, 0, &key); + if (ret) + break; + + if (need_resched() || + rwsem_is_contended(&fs_info->commit_root_sem)) { + caching_ctl->progress = last; + btrfs_release_path(path); + up_read(&fs_info->commit_root_sem); + mutex_unlock(&caching_ctl->mutex); + cond_resched(); + goto again; + } + + ret = btrfs_next_leaf(extent_root, path); + if (ret < 0) + goto err; + if (ret) + break; + leaf = path->nodes[0]; + nritems = btrfs_header_nritems(leaf); + continue; + } + + if (key.objectid < last) { + key.objectid = last; + key.offset = 0; + key.type = BTRFS_EXTENT_ITEM_KEY; + + caching_ctl->progress = last; + btrfs_release_path(path); + goto next; + } + + if (key.objectid < block_group->key.objectid) { + path->slots[0]++; + continue; + } + + if (key.objectid >= block_group->key.objectid + + block_group->key.offset) + break; + + if (key.type == BTRFS_EXTENT_ITEM_KEY || + key.type == BTRFS_METADATA_ITEM_KEY) { + total_found += add_new_free_space(block_group, + fs_info, last, + key.objectid); + if (key.type == BTRFS_METADATA_ITEM_KEY) + last = key.objectid + + fs_info->tree_root->nodesize; + else + 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->commit_root_sem); + + free_excluded_extents(extent_root, block_group); + + mutex_unlock(&caching_ctl->mutex); +out: + if (ret) { + spin_lock(&block_group->lock); + block_group->caching_ctl = NULL; + block_group->cached = BTRFS_CACHE_ERROR; + spin_unlock(&block_group->lock); + } + wake_up(&caching_ctl->wait); + + put_caching_control(caching_ctl); + btrfs_put_block_group(block_group); +} + +static int cache_block_group(struct btrfs_block_group_cache *cache, + int load_cache_only) +{ + DEFINE_WAIT(wait); + struct btrfs_fs_info *fs_info = cache->fs_info; + struct btrfs_caching_control *caching_ctl; + int ret = 0; + + caching_ctl = kzalloc(sizeof(*caching_ctl), GFP_NOFS); + if (!caching_ctl) + return -ENOMEM; + + INIT_LIST_HEAD(&caching_ctl->list); + mutex_init(&caching_ctl->mutex); + init_waitqueue_head(&caching_ctl->wait); + caching_ctl->block_group = cache; + caching_ctl->progress = cache->key.objectid; + atomic_set(&caching_ctl->count, 1); + btrfs_init_work(&caching_ctl->work, btrfs_cache_helper, + caching_thread, NULL, NULL); + + spin_lock(&cache->lock); + /* + * This should be a rare occasion, but this could happen I think in the + * case where one thread starts to load the space cache info, and then + * some other thread starts a transaction commit which tries to do an + * allocation while the other thread is still loading the space cache + * info. The previous loop should have kept us from choosing this block + * group, but if we've moved to the state where we will wait on caching + * block groups we need to first check if we're doing a fast load here, + * so we can wait for it to finish, otherwise we could end up allocating + * from a block group who's cache gets evicted for one reason or + * another. + */ + while (cache->cached == BTRFS_CACHE_FAST) { + struct btrfs_caching_control *ctl; + + ctl = cache->caching_ctl; + atomic_inc(&ctl->count); + prepare_to_wait(&ctl->wait, &wait, TASK_UNINTERRUPTIBLE); + spin_unlock(&cache->lock); + + schedule(); + + finish_wait(&ctl->wait, &wait); + put_caching_control(ctl); + spin_lock(&cache->lock); + } + + if (cache->cached != BTRFS_CACHE_NO) { + spin_unlock(&cache->lock); + kfree(caching_ctl); + return 0; + } + WARN_ON(cache->caching_ctl); + cache->caching_ctl = caching_ctl; + cache->cached = BTRFS_CACHE_FAST; + spin_unlock(&cache->lock); + + if (fs_info->mount_opt & BTRFS_MOUNT_SPACE_CACHE) { + mutex_lock(&caching_ctl->mutex); + ret = load_free_space_cache(fs_info, cache); + + spin_lock(&cache->lock); + if (ret == 1) { + cache->caching_ctl = NULL; + cache->cached = BTRFS_CACHE_FINISHED; + cache->last_byte_to_unpin = (u64)-1; + caching_ctl->progress = (u64)-1; + } else { + if (load_cache_only) { + cache->caching_ctl = NULL; + cache->cached = BTRFS_CACHE_NO; + } else { + cache->cached = BTRFS_CACHE_STARTED; + cache->has_caching_ctl = 1; + } + } + spin_unlock(&cache->lock); + mutex_unlock(&caching_ctl->mutex); + + wake_up(&caching_ctl->wait); + if (ret == 1) { + put_caching_control(caching_ctl); + free_excluded_extents(fs_info->extent_root, cache); + return 0; + } + } else { + /* + * We are not going to do the fast caching, set cached to the + * appropriate value and wakeup any waiters. + */ + spin_lock(&cache->lock); + if (load_cache_only) { + cache->caching_ctl = NULL; + cache->cached = BTRFS_CACHE_NO; + } else { + cache->cached = BTRFS_CACHE_STARTED; + cache->has_caching_ctl = 1; + } + spin_unlock(&cache->lock); + wake_up(&caching_ctl->wait); + } + + if (load_cache_only) { + put_caching_control(caching_ctl); + return 0; + } + + down_write(&fs_info->commit_root_sem); + atomic_inc(&caching_ctl->count); + list_add_tail(&caching_ctl->list, &fs_info->caching_block_groups); + up_write(&fs_info->commit_root_sem); + + btrfs_get_block_group(cache); + + btrfs_queue_work(fs_info->caching_workers, &caching_ctl->work); + + return ret; +} + +/* + * 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; + + flags &= BTRFS_BLOCK_GROUP_TYPE_MASK; + + 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(); +} + +/* simple helper to search for an existing data extent at a given offset */ +int btrfs_lookup_data_extent(struct btrfs_root *root, u64 start, u64 len) +{ + int ret; + struct btrfs_key key; + struct btrfs_path *path; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = start; + key.offset = len; + key.type = BTRFS_EXTENT_ITEM_KEY; + ret = btrfs_search_slot(NULL, root->fs_info->extent_root, &key, path, + 0, 0); + btrfs_free_path(path); + return ret; +} + +/* + * helper function to lookup reference count and flags of a tree block. + * + * the head node for delayed ref is used to store the sum of all the + * reference count modifications queued up in the rbtree. the head + * node may also store the extent flags to set. This way you can check + * to see what the reference count and extent flags would be if all of + * the delayed refs are not processed. + */ +int btrfs_lookup_extent_info(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 offset, int metadata, u64 *refs, u64 *flags) +{ + struct btrfs_delayed_ref_head *head; + struct btrfs_delayed_ref_root *delayed_refs; + struct btrfs_path *path; + struct btrfs_extent_item *ei; + struct extent_buffer *leaf; + struct btrfs_key key; + u32 item_size; + u64 num_refs; + u64 extent_flags; + int ret; + + /* + * If we don't have skinny metadata, don't bother doing anything + * different + */ + if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) { + offset = root->nodesize; + metadata = 0; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + if (!trans) { + path->skip_locking = 1; + path->search_commit_root = 1; + } + +search_again: + key.objectid = bytenr; + key.offset = offset; + if (metadata) + key.type = BTRFS_METADATA_ITEM_KEY; + else + key.type = BTRFS_EXTENT_ITEM_KEY; + + ret = btrfs_search_slot(trans, root->fs_info->extent_root, + &key, path, 0, 0); + if (ret < 0) + goto out_free; + + if (ret > 0 && metadata && key.type == BTRFS_METADATA_ITEM_KEY) { + if (path->slots[0]) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid == bytenr && + key.type == BTRFS_EXTENT_ITEM_KEY && + key.offset == root->nodesize) + ret = 0; + } + } + + if (ret == 0) { + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + if (item_size >= sizeof(*ei)) { + ei = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_item); + num_refs = btrfs_extent_refs(leaf, ei); + extent_flags = btrfs_extent_flags(leaf, ei); + } else { +#ifdef BTRFS_COMPAT_EXTENT_TREE_V0 + struct btrfs_extent_item_v0 *ei0; + BUG_ON(item_size != sizeof(*ei0)); + ei0 = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_item_v0); + num_refs = btrfs_extent_refs_v0(leaf, ei0); + /* FIXME: this isn't correct for data */ + extent_flags = BTRFS_BLOCK_FLAG_FULL_BACKREF; +#else + BUG(); +#endif + } + BUG_ON(num_refs == 0); + } else { + num_refs = 0; + extent_flags = 0; + ret = 0; + } + + if (!trans) + goto out; + + delayed_refs = &trans->transaction->delayed_refs; + spin_lock(&delayed_refs->lock); + head = btrfs_find_delayed_ref_head(trans, bytenr); + if (head) { + if (!mutex_trylock(&head->mutex)) { + atomic_inc(&head->node.refs); + spin_unlock(&delayed_refs->lock); + + btrfs_release_path(path); + + /* + * Mutex was contended, block until it's released and try + * again + */ + mutex_lock(&head->mutex); + mutex_unlock(&head->mutex); + btrfs_put_delayed_ref(&head->node); + goto search_again; + } + spin_lock(&head->lock); + if (head->extent_op && head->extent_op->update_flags) + extent_flags |= head->extent_op->flags_to_set; + else + BUG_ON(num_refs == 0); + + num_refs += head->node.ref_mod; + spin_unlock(&head->lock); + mutex_unlock(&head->mutex); + } + spin_unlock(&delayed_refs->lock); +out: + WARN_ON(num_refs == 0); + if (refs) + *refs = num_refs; + if (flags) + *flags = extent_flags; +out_free: + btrfs_free_path(path); + return ret; +} + +/* + * Back reference rules. Back refs have three main goals: + * + * 1) differentiate between all holders of references to an extent so that + * when a reference is dropped we can make sure it was a valid reference + * before freeing the extent. + * + * 2) Provide enough information to quickly find the holders of an extent + * if we notice a given block is corrupted or bad. + * + * 3) Make it easy to migrate blocks for FS shrinking or storage pool + * maintenance. This is actually the same as #2, but with a slightly + * different use case. + * + * There are two kinds of back refs. The implicit back refs is optimized + * for pointers in non-shared tree blocks. For a given pointer in a block, + * back refs of this kind provide information about the block's owner tree + * and the pointer's key. These information allow us to find the block by + * b-tree searching. The full back refs is for pointers in tree blocks not + * referenced by their owner trees. The location of tree block is recorded + * in the back refs. Actually the full back refs is generic, and can be + * used in all cases the implicit back refs is used. The major shortcoming + * of the full back refs is its overhead. Every time a tree block gets + * COWed, we have to update back refs entry for all pointers in it. + * + * For a newly allocated tree block, we use implicit back refs for + * pointers in it. This means most tree related operations only involve + * implicit back refs. For a tree block created in old transaction, the + * only way to drop a reference to it is COW it. So we can detect the + * event that tree block loses its owner tree's reference and do the + * back refs conversion. + * + * When a tree block is 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); /* Corruption */ + 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(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); /* Corruption */ + + btrfs_extend_item(root, path, new_size); + + 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 = btrfs_crc32c(high_crc, &lenum, sizeof(lenum)); + lenum = cpu_to_le64(owner); + low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); + lenum = cpu_to_le64(offset); + low_crc = btrfs_crc32c(low_crc, &lenum, sizeof(lenum)); + + return ((u64)high_crc << 31) ^ (u64)low_crc; +} + +static u64 hash_extent_data_ref_item(struct extent_buffer *leaf, + struct btrfs_extent_data_ref *ref) +{ + return hash_extent_data_ref(btrfs_extent_data_ref_root(leaf, ref), + btrfs_extent_data_ref_objectid(leaf, ref), + btrfs_extent_data_ref_offset(leaf, ref)); +} + +static int match_extent_data_ref(struct extent_buffer *leaf, + struct btrfs_extent_data_ref *ref, + u64 root_objectid, u64 owner, u64 offset) +{ + if (btrfs_extent_data_ref_root(leaf, ref) != root_objectid || + btrfs_extent_data_ref_objectid(leaf, ref) != owner || + btrfs_extent_data_ref_offset(leaf, ref) != offset) + return 0; + return 1; +} + +static noinline int lookup_extent_data_ref(struct btrfs_trans_handle *trans, + struct btrfs_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(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(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(path); + key.offset++; + ret = btrfs_insert_empty_item(trans, root, path, &key, + size); + if (ret && ret != -EEXIST) + goto fail; + + leaf = path->nodes[0]; + } + ref = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_data_ref); + if (ret == 0) { + btrfs_set_extent_data_ref_root(leaf, ref, + root_objectid); + btrfs_set_extent_data_ref_objectid(leaf, ref, owner); + btrfs_set_extent_data_ref_offset(leaf, ref, offset); + btrfs_set_extent_data_ref_count(leaf, ref, refs_to_add); + } else { + num_refs = btrfs_extent_data_ref_count(leaf, ref); + num_refs += refs_to_add; + btrfs_set_extent_data_ref_count(leaf, ref, num_refs); + } + } + btrfs_mark_buffer_dirty(leaf); + ret = 0; +fail: + btrfs_release_path(path); + return ret; +} + +static noinline int remove_extent_data_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + int refs_to_drop, int *last_ref) +{ + struct btrfs_key key; + struct btrfs_extent_data_ref *ref1 = NULL; + struct btrfs_shared_data_ref *ref2 = NULL; + struct extent_buffer *leaf; + u32 num_refs = 0; + int ret = 0; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + if (key.type == BTRFS_EXTENT_DATA_REF_KEY) { + ref1 = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_data_ref); + num_refs = btrfs_extent_data_ref_count(leaf, ref1); + } else if (key.type == BTRFS_SHARED_DATA_REF_KEY) { + ref2 = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_shared_data_ref); + num_refs = btrfs_shared_data_ref_count(leaf, ref2); +#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); + *last_ref = 1; + } else { + if (key.type == BTRFS_EXTENT_DATA_REF_KEY) + btrfs_set_extent_data_ref_count(leaf, ref1, num_refs); + else if (key.type == BTRFS_SHARED_DATA_REF_KEY) + btrfs_set_shared_data_ref_count(leaf, ref2, num_refs); +#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(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(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; + bool skinny_metadata = btrfs_fs_incompat(root->fs_info, + SKINNY_METADATA); + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = num_bytes; + + want = extent_ref_type(parent, owner); + if (insert) { + extra_size = btrfs_extent_inline_ref_size(want); + path->keep_locks = 1; + } else + extra_size = -1; + + /* + * Owner is our parent level, so we can just add one to get the level + * for the block we are interested in. + */ + if (skinny_metadata && owner < BTRFS_FIRST_FREE_OBJECTID) { + key.type = BTRFS_METADATA_ITEM_KEY; + key.offset = owner; + } + +again: + ret = btrfs_search_slot(trans, root, &key, path, extra_size, 1); + if (ret < 0) { + err = ret; + goto out; + } + + /* + * We may be a newly converted file system which still has the old fat + * extent entries for metadata, so try and see if we have one of those. + */ + if (ret > 0 && skinny_metadata) { + skinny_metadata = false; + if (path->slots[0]) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid == bytenr && + key.type == BTRFS_EXTENT_ITEM_KEY && + key.offset == num_bytes) + ret = 0; + } + if (ret) { + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = num_bytes; + btrfs_release_path(path); + goto again; + } + } + + if (ret && !insert) { + err = -ENOENT; + goto out; + } else if (WARN_ON(ret)) { + err = -EIO; + goto out; + } + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); +#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 && !skinny_metadata) { + ptr += sizeof(struct btrfs_tree_block_info); + BUG_ON(ptr > end); + } + + 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 +void setup_inline_extent_backref(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; + + leaf = path->nodes[0]; + ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); + item_offset = (unsigned long)iref - (unsigned long)ei; + + type = extent_ref_type(parent, owner); + size = btrfs_extent_inline_ref_size(type); + + btrfs_extend_item(root, path, size); + + ei = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); + refs = btrfs_extent_refs(leaf, ei); + refs += refs_to_add; + btrfs_set_extent_refs(leaf, ei, refs); + if (extent_op) + __run_delayed_extent_op(extent_op, leaf, ei); + + ptr = (unsigned long)ei + item_offset; + end = (unsigned long)ei + btrfs_item_size_nr(leaf, path->slots[0]); + if (ptr < end - size) + memmove_extent_buffer(leaf, ptr + size, ptr, + end - size - ptr); + + iref = (struct btrfs_extent_inline_ref *)ptr; + btrfs_set_extent_inline_ref_type(leaf, iref, type); + if (type == BTRFS_EXTENT_DATA_REF_KEY) { + struct btrfs_extent_data_ref *dref; + dref = (struct btrfs_extent_data_ref *)(&iref->offset); + btrfs_set_extent_data_ref_root(leaf, dref, root_objectid); + btrfs_set_extent_data_ref_objectid(leaf, dref, owner); + btrfs_set_extent_data_ref_offset(leaf, dref, offset); + btrfs_set_extent_data_ref_count(leaf, dref, refs_to_add); + } else if (type == BTRFS_SHARED_DATA_REF_KEY) { + struct btrfs_shared_data_ref *sref; + sref = (struct btrfs_shared_data_ref *)(iref + 1); + btrfs_set_shared_data_ref_count(leaf, sref, refs_to_add); + btrfs_set_extent_inline_ref_offset(leaf, iref, parent); + } else if (type == BTRFS_SHARED_BLOCK_REF_KEY) { + btrfs_set_extent_inline_ref_offset(leaf, iref, parent); + } else { + btrfs_set_extent_inline_ref_offset(leaf, iref, root_objectid); + } + btrfs_mark_buffer_dirty(leaf); +} + +static int lookup_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_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(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 +void update_inline_extent_backref(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, + int *last_ref) +{ + 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; + 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 { + *last_ref = 1; + size = btrfs_extent_inline_ref_size(type); + item_size = btrfs_item_size_nr(leaf, path->slots[0]); + ptr = (unsigned long)iref; + end = (unsigned long)ei + item_size; + if (ptr + size < end) + memmove_extent_buffer(leaf, ptr, ptr + size, + end - ptr - size); + item_size -= size; + btrfs_truncate_item(root, path, item_size, 1); + } + btrfs_mark_buffer_dirty(leaf); +} + +static noinline_for_stack +int insert_inline_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_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); + update_inline_extent_backref(root, path, iref, + refs_to_add, extent_op, NULL); + } else if (ret == -ENOENT) { + setup_inline_extent_backref(root, path, iref, parent, + root_objectid, owner, offset, + refs_to_add, extent_op); + ret = 0; + } + return ret; +} + +static int insert_extent_backref(struct btrfs_trans_handle *trans, + struct btrfs_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 *last_ref) +{ + int ret = 0; + + BUG_ON(!is_data && refs_to_drop != 1); + if (iref) { + update_inline_extent_backref(root, path, iref, + -refs_to_drop, NULL, last_ref); + } else if (is_data) { + ret = remove_extent_data_ref(trans, root, path, refs_to_drop, + last_ref); + } else { + *last_ref = 1; + ret = btrfs_del_item(trans, root, path); + } + return ret; +} + +static int btrfs_issue_discard(struct block_device *bdev, + u64 start, u64 len) +{ + return blkdev_issue_discard(bdev, start >> 9, len >> 9, GFP_NOFS, 0); +} + +int btrfs_discard_extent(struct btrfs_root *root, u64 bytenr, + u64 num_bytes, u64 *actual_bytes) +{ + int ret; + u64 discarded_bytes = 0; + struct btrfs_bio *bbio = NULL; + + + /* Tell the block device(s) that the sectors can be discarded */ + ret = btrfs_map_block(root->fs_info, REQ_DISCARD, + bytenr, &num_bytes, &bbio, 0); + /* Error condition is -ENOMEM */ + if (!ret) { + struct btrfs_bio_stripe *stripe = bbio->stripes; + int i; + + + for (i = 0; i < bbio->num_stripes; i++, stripe++) { + if (!stripe->dev->can_discard) + continue; + + ret = btrfs_issue_discard(stripe->dev->bdev, + stripe->physical, + stripe->length); + if (!ret) + discarded_bytes += stripe->length; + else if (ret != -EOPNOTSUPP) + break; /* Logic errors or -ENOMEM, or -EIO but I don't know how that could happen JDM */ + + /* + * Just in case we get back EOPNOTSUPP for some reason, + * just ignore the return value so we don't screw up + * people calling discard_extent. + */ + ret = 0; + } + btrfs_put_bbio(bbio); + } + + if (actual_bytes) + *actual_bytes = discarded_bytes; + + + if (ret == -EOPNOTSUPP) + ret = 0; + return ret; +} + +/* Can return -ENOMEM */ +int btrfs_inc_extent_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, + u64 root_objectid, u64 owner, u64 offset, + int no_quota) +{ + int ret; + struct btrfs_fs_info *fs_info = root->fs_info; + + 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(fs_info, trans, bytenr, + num_bytes, + parent, root_objectid, (int)owner, + BTRFS_ADD_DELAYED_REF, NULL, no_quota); + } else { + ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, + num_bytes, + parent, root_objectid, owner, offset, + BTRFS_ADD_DELAYED_REF, NULL, no_quota); + } + 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, + int no_quota, + struct btrfs_delayed_extent_op *extent_op) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_path *path; + struct extent_buffer *leaf; + struct btrfs_extent_item *item; + struct btrfs_key key; + u64 refs; + int ret; + enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_ADD_EXCL; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + if (!is_fstree(root_objectid) || !root->fs_info->quota_enabled) + no_quota = 1; + + 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, fs_info->extent_root, path, + bytenr, num_bytes, parent, + root_objectid, owner, offset, + refs_to_add, extent_op); + if ((ret < 0 && ret != -EAGAIN) || (!ret && no_quota)) + goto out; + /* + * Ok we were able to insert an inline extent and it appears to be a new + * reference, deal with the qgroup accounting. + */ + if (!ret && !no_quota) { + ASSERT(root->fs_info->quota_enabled); + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_item); + if (btrfs_extent_refs(leaf, item) > (u64)refs_to_add) + type = BTRFS_QGROUP_OPER_ADD_SHARED; + btrfs_release_path(path); + + ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid, + bytenr, num_bytes, type, 0); + goto out; + } + + /* + * Ok we had -EAGAIN which means we didn't have space to insert and + * inline extent ref, so just update the reference count and add a + * normal backref. + */ + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + item = btrfs_item_ptr(leaf, path->slots[0], struct btrfs_extent_item); + refs = btrfs_extent_refs(leaf, item); + if (refs) + type = BTRFS_QGROUP_OPER_ADD_SHARED; + btrfs_set_extent_refs(leaf, item, refs + refs_to_add); + if (extent_op) + __run_delayed_extent_op(extent_op, leaf, item); + + btrfs_mark_buffer_dirty(leaf); + btrfs_release_path(path); + + if (!no_quota) { + ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid, + bytenr, num_bytes, type, 0); + if (ret) + goto out; + } + + 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); + if (ret) + btrfs_abort_transaction(trans, root, ret); +out: + btrfs_free_path(path); + return ret; +} + +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); + trace_run_delayed_data_ref(node, ref, node->action); + + if (node->type == BTRFS_SHARED_DATA_REF_KEY) + parent = ref->parent; + ref_root = ref->root; + + if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { + if (extent_op) + flags |= extent_op->flags_to_set; + ret = alloc_reserved_file_extent(trans, 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, + node->no_quota, 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, node->no_quota); + } 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; + int metadata = !extent_op->is_data; + + if (trans->aborted) + return 0; + + if (metadata && !btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) + metadata = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + key.objectid = node->bytenr; + + if (metadata) { + key.type = BTRFS_METADATA_ITEM_KEY; + key.offset = extent_op->level; + } else { + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = node->num_bytes; + } + +again: + 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) { + if (metadata) { + if (path->slots[0] > 0) { + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid == node->bytenr && + key.type == BTRFS_EXTENT_ITEM_KEY && + key.offset == node->num_bytes) + ret = 0; + } + if (ret > 0) { + btrfs_release_path(path); + metadata = 0; + + key.objectid = node->bytenr; + key.offset = node->num_bytes; + key.type = BTRFS_EXTENT_ITEM_KEY; + goto again; + } + } else { + err = -EIO; + goto out; + } + } + + leaf = path->nodes[0]; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); +#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; + bool skinny_metadata = btrfs_fs_incompat(root->fs_info, + SKINNY_METADATA); + + ref = btrfs_delayed_node_to_tree_ref(node); + trace_run_delayed_tree_ref(node, ref, node->action); + + if (node->type == BTRFS_SHARED_BLOCK_REF_KEY) + parent = ref->parent; + ref_root = ref->root; + + ins.objectid = node->bytenr; + if (skinny_metadata) { + ins.offset = ref->level; + ins.type = BTRFS_METADATA_ITEM_KEY; + } else { + ins.offset = node->num_bytes; + ins.type = BTRFS_EXTENT_ITEM_KEY; + } + + BUG_ON(node->ref_mod != 1); + if (node->action == BTRFS_ADD_DELAYED_REF && insert_reserved) { + BUG_ON(!extent_op || !extent_op->update_flags); + ret = alloc_reserved_tree_block(trans, root, + parent, ref_root, + extent_op->flags_to_set, + &extent_op->key, + ref->level, &ins, + node->no_quota); + } 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, node->no_quota, + 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, + node->no_quota); + } 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 = 0; + + if (trans->aborted) { + if (insert_reserved) + btrfs_pin_extent(root, node->bytenr, + node->num_bytes, 1); + return 0; + } + + 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); + trace_run_delayed_ref_head(node, head, node->action); + + if (insert_reserved) { + btrfs_pin_extent(root, node->bytenr, + node->num_bytes, 1); + if (head->is_data) { + ret = btrfs_del_csums(trans, root, + node->bytenr, + node->num_bytes); + } + } + return ret; + } + + 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, *last = NULL;; + + /* + * 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_first(&head->ref_root); + while (node) { + ref = rb_entry(node, struct btrfs_delayed_ref_node, + rb_node); + if (ref->action == BTRFS_ADD_DELAYED_REF) + return ref; + else if (last == NULL) + last = ref; + node = rb_next(node); + } + return last; +} + +/* + * Returns 0 on success or if called with an already aborted transaction. + * Returns -ENOMEM or -EIO on failure and will abort the transaction. + */ +static noinline int __btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + unsigned long nr) +{ + 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; + struct btrfs_fs_info *fs_info = root->fs_info; + ktime_t start = ktime_get(); + int ret; + unsigned long count = 0; + unsigned long actual_count = 0; + int must_insert_reserved = 0; + + delayed_refs = &trans->transaction->delayed_refs; + while (1) { + if (!locked_ref) { + if (count >= nr) + break; + + spin_lock(&delayed_refs->lock); + locked_ref = btrfs_select_ref_head(trans); + if (!locked_ref) { + spin_unlock(&delayed_refs->lock); + break; + } + + /* grab the lock that says we are going to process + * all the refs for this head */ + ret = btrfs_delayed_ref_lock(trans, locked_ref); + spin_unlock(&delayed_refs->lock); + /* + * we may have dropped the spin lock to get the head + * mutex lock, and that might have given someone else + * time to free the head. If that's true, it has been + * removed from our list and we can move on. + */ + if (ret == -EAGAIN) { + locked_ref = NULL; + count++; + continue; + } + } + + /* + * We need to try and merge add/drops of the same ref since we + * can run into issues with relocate dropping the implicit ref + * and then it being added back again before the drop can + * finish. If we merged anything we need to re-loop so we can + * get a good ref. + */ + spin_lock(&locked_ref->lock); + btrfs_merge_delayed_refs(trans, fs_info, delayed_refs, + locked_ref); + + /* + * 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 && ref->seq && + btrfs_check_delayed_seq(fs_info, delayed_refs, ref->seq)) { + spin_unlock(&locked_ref->lock); + btrfs_delayed_ref_unlock(locked_ref); + spin_lock(&delayed_refs->lock); + locked_ref->processing = 0; + delayed_refs->num_heads_ready++; + spin_unlock(&delayed_refs->lock); + locked_ref = NULL; + cond_resched(); + 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; + + 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) { + btrfs_free_delayed_extent_op(extent_op); + extent_op = NULL; + } + + if (extent_op) { + spin_unlock(&locked_ref->lock); + ret = run_delayed_extent_op(trans, root, + ref, extent_op); + btrfs_free_delayed_extent_op(extent_op); + + if (ret) { + /* + * Need to reset must_insert_reserved if + * there was an error so the abort stuff + * can cleanup the reserved space + * properly. + */ + if (must_insert_reserved) + locked_ref->must_insert_reserved = 1; + locked_ref->processing = 0; + btrfs_debug(fs_info, "run_delayed_extent_op returned %d", ret); + btrfs_delayed_ref_unlock(locked_ref); + return ret; + } + continue; + } + + /* + * Need to drop our head ref lock and re-aqcuire the + * delayed ref lock and then re-check to make sure + * nobody got added. + */ + spin_unlock(&locked_ref->lock); + spin_lock(&delayed_refs->lock); + spin_lock(&locked_ref->lock); + if (rb_first(&locked_ref->ref_root) || + locked_ref->extent_op) { + spin_unlock(&locked_ref->lock); + spin_unlock(&delayed_refs->lock); + continue; + } + ref->in_tree = 0; + delayed_refs->num_heads--; + rb_erase(&locked_ref->href_node, + &delayed_refs->href_root); + spin_unlock(&delayed_refs->lock); + } else { + actual_count++; + ref->in_tree = 0; + rb_erase(&ref->rb_node, &locked_ref->ref_root); + } + atomic_dec(&delayed_refs->num_entries); + + if (!btrfs_delayed_ref_is_head(ref)) { + /* + * when we play the delayed ref, also correct the + * ref_mod on head + */ + switch (ref->action) { + case BTRFS_ADD_DELAYED_REF: + case BTRFS_ADD_DELAYED_EXTENT: + locked_ref->node.ref_mod -= ref->ref_mod; + break; + case BTRFS_DROP_DELAYED_REF: + locked_ref->node.ref_mod += ref->ref_mod; + break; + default: + WARN_ON(1); + } + } + spin_unlock(&locked_ref->lock); + + ret = run_one_delayed_ref(trans, root, ref, extent_op, + must_insert_reserved); + + btrfs_free_delayed_extent_op(extent_op); + if (ret) { + locked_ref->processing = 0; + btrfs_delayed_ref_unlock(locked_ref); + btrfs_put_delayed_ref(ref); + btrfs_debug(fs_info, "run_one_delayed_ref returned %d", ret); + return ret; + } + + /* + * If this node is a head, that means all the refs in this head + * have been dealt with, and we will pick the next head to deal + * with, so we must unlock the head and drop it from the cluster + * list before we release it. + */ + if (btrfs_delayed_ref_is_head(ref)) { + if (locked_ref->is_data && + locked_ref->total_ref_mod < 0) { + spin_lock(&delayed_refs->lock); + delayed_refs->pending_csums -= ref->num_bytes; + spin_unlock(&delayed_refs->lock); + } + btrfs_delayed_ref_unlock(locked_ref); + locked_ref = NULL; + } + btrfs_put_delayed_ref(ref); + count++; + cond_resched(); + } + + /* + * We don't want to include ref heads since we can have empty ref heads + * and those will drastically skew our runtime down since we just do + * accounting, no actual extent tree updates. + */ + if (actual_count > 0) { + u64 runtime = ktime_to_ns(ktime_sub(ktime_get(), start)); + u64 avg; + + /* + * We weigh the current average higher than our current runtime + * to avoid large swings in the average. + */ + spin_lock(&delayed_refs->lock); + avg = fs_info->avg_delayed_ref_runtime * 3 + runtime; + fs_info->avg_delayed_ref_runtime = avg >> 2; /* div by 4 */ + spin_unlock(&delayed_refs->lock); + } + return 0; +} + +#ifdef SCRAMBLE_DELAYED_REFS +/* + * Normally delayed refs get processed in ascending bytenr order. This + * correlates in most cases to the order added. To expose dependencies on this + * order, we start to process the tree in the middle instead of the beginning + */ +static u64 find_middle(struct rb_root *root) +{ + struct rb_node *n = root->rb_node; + struct btrfs_delayed_ref_node *entry; + int alt = 1; + u64 middle; + u64 first = 0, last = 0; + + n = rb_first(root); + if (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + first = entry->bytenr; + } + n = rb_last(root); + if (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + last = entry->bytenr; + } + n = root->rb_node; + + while (n) { + entry = rb_entry(n, struct btrfs_delayed_ref_node, rb_node); + WARN_ON(!entry->in_tree); + + middle = entry->bytenr; + + if (alt) + n = n->rb_left; + else + n = n->rb_right; + + alt = 1 - alt; + } + return middle; +} +#endif + +static inline u64 heads_to_leaves(struct btrfs_root *root, u64 heads) +{ + u64 num_bytes; + + num_bytes = heads * (sizeof(struct btrfs_extent_item) + + sizeof(struct btrfs_extent_inline_ref)); + if (!btrfs_fs_incompat(root->fs_info, SKINNY_METADATA)) + num_bytes += heads * sizeof(struct btrfs_tree_block_info); + + /* + * We don't ever fill up leaves all the way so multiply by 2 just to be + * closer to what we're really going to want to ouse. + */ + return div_u64(num_bytes, BTRFS_LEAF_DATA_SIZE(root)); +} + +/* + * Takes the number of bytes to be csumm'ed and figures out how many leaves it + * would require to store the csums for that many bytes. + */ +u64 btrfs_csum_bytes_to_leaves(struct btrfs_root *root, u64 csum_bytes) +{ + u64 csum_size; + u64 num_csums_per_leaf; + u64 num_csums; + + csum_size = BTRFS_LEAF_DATA_SIZE(root) - sizeof(struct btrfs_item); + num_csums_per_leaf = div64_u64(csum_size, + (u64)btrfs_super_csum_size(root->fs_info->super_copy)); + num_csums = div64_u64(csum_bytes, root->sectorsize); + num_csums += num_csums_per_leaf - 1; + num_csums = div64_u64(num_csums, num_csums_per_leaf); + return num_csums; +} + +int btrfs_check_space_for_delayed_refs(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_rsv *global_rsv; + u64 num_heads = trans->transaction->delayed_refs.num_heads_ready; + u64 csum_bytes = trans->transaction->delayed_refs.pending_csums; + u64 num_dirty_bgs = trans->transaction->num_dirty_bgs; + u64 num_bytes, num_dirty_bgs_bytes; + int ret = 0; + + num_bytes = btrfs_calc_trans_metadata_size(root, 1); + num_heads = heads_to_leaves(root, num_heads); + if (num_heads > 1) + num_bytes += (num_heads - 1) * root->nodesize; + num_bytes <<= 1; + num_bytes += btrfs_csum_bytes_to_leaves(root, csum_bytes) * root->nodesize; + num_dirty_bgs_bytes = btrfs_calc_trans_metadata_size(root, + num_dirty_bgs); + global_rsv = &root->fs_info->global_block_rsv; + + /* + * If we can't allocate any more chunks lets make sure we have _lots_ of + * wiggle room since running delayed refs can create more delayed refs. + */ + if (global_rsv->space_info->full) { + num_dirty_bgs_bytes <<= 1; + num_bytes <<= 1; + } + + spin_lock(&global_rsv->lock); + if (global_rsv->reserved <= num_bytes + num_dirty_bgs_bytes) + ret = 1; + spin_unlock(&global_rsv->lock); + return ret; +} + +int btrfs_should_throttle_delayed_refs(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + u64 num_entries = + atomic_read(&trans->transaction->delayed_refs.num_entries); + u64 avg_runtime; + u64 val; + + smp_mb(); + avg_runtime = fs_info->avg_delayed_ref_runtime; + val = num_entries * avg_runtime; + if (num_entries * avg_runtime >= NSEC_PER_SEC) + return 1; + if (val >= NSEC_PER_SEC / 2) + return 2; + + return btrfs_check_space_for_delayed_refs(trans, root); +} + +struct async_delayed_refs { + struct btrfs_root *root; + int count; + int error; + int sync; + struct completion wait; + struct btrfs_work work; +}; + +static void delayed_ref_async_start(struct btrfs_work *work) +{ + struct async_delayed_refs *async; + struct btrfs_trans_handle *trans; + int ret; + + async = container_of(work, struct async_delayed_refs, work); + + trans = btrfs_join_transaction(async->root); + if (IS_ERR(trans)) { + async->error = PTR_ERR(trans); + goto done; + } + + /* + * trans->sync means that when we call end_transaciton, we won't + * wait on delayed refs + */ + trans->sync = true; + ret = btrfs_run_delayed_refs(trans, async->root, async->count); + if (ret) + async->error = ret; + + ret = btrfs_end_transaction(trans, async->root); + if (ret && !async->error) + async->error = ret; +done: + if (async->sync) + complete(&async->wait); + else + kfree(async); +} + +int btrfs_async_run_delayed_refs(struct btrfs_root *root, + unsigned long count, int wait) +{ + struct async_delayed_refs *async; + int ret; + + async = kmalloc(sizeof(*async), GFP_NOFS); + if (!async) + return -ENOMEM; + + async->root = root->fs_info->tree_root; + async->count = count; + async->error = 0; + if (wait) + async->sync = 1; + else + async->sync = 0; + init_completion(&async->wait); + + btrfs_init_work(&async->work, btrfs_extent_refs_helper, + delayed_ref_async_start, NULL, NULL); + + btrfs_queue_work(root->fs_info->extent_workers, &async->work); + + if (wait) { + wait_for_completion(&async->wait); + ret = async->error; + kfree(async); + return ret; + } + return 0; +} + +/* + * this starts processing the delayed reference count updates and + * extent insertions we have queued up so far. count can be + * 0, which means to process everything in the tree at the start + * of the run (but not newly added entries), or it can be some target + * number you'd like to process. + * + * Returns 0 on success or if called with an aborted transaction + * Returns <0 on error and aborts the transaction + */ +int btrfs_run_delayed_refs(struct btrfs_trans_handle *trans, + struct btrfs_root *root, unsigned long count) +{ + struct rb_node *node; + struct btrfs_delayed_ref_root *delayed_refs; + struct btrfs_delayed_ref_head *head; + int ret; + int run_all = count == (unsigned long)-1; + + /* We'll clean this up in btrfs_cleanup_transaction */ + if (trans->aborted) + return 0; + + if (root == root->fs_info->extent_root) + root = root->fs_info->tree_root; + + delayed_refs = &trans->transaction->delayed_refs; + if (count == 0) + count = atomic_read(&delayed_refs->num_entries) * 2; + +again: +#ifdef SCRAMBLE_DELAYED_REFS + delayed_refs->run_delayed_start = find_middle(&delayed_refs->root); +#endif + ret = __btrfs_run_delayed_refs(trans, root, count); + if (ret < 0) { + btrfs_abort_transaction(trans, root, ret); + return ret; + } + + if (run_all) { + if (!list_empty(&trans->new_bgs)) + btrfs_create_pending_block_groups(trans, root); + + spin_lock(&delayed_refs->lock); + node = rb_first(&delayed_refs->href_root); + if (!node) { + spin_unlock(&delayed_refs->lock); + goto out; + } + count = (unsigned long)-1; + + while (node) { + head = rb_entry(node, struct btrfs_delayed_ref_head, + href_node); + if (btrfs_delayed_ref_is_head(&head->node)) { + struct btrfs_delayed_ref_node *ref; + + ref = &head->node; + atomic_inc(&ref->refs); + + spin_unlock(&delayed_refs->lock); + /* + * Mutex was contended, block until it's + * released and try again + */ + mutex_lock(&head->mutex); + mutex_unlock(&head->mutex); + + btrfs_put_delayed_ref(ref); + cond_resched(); + goto again; + } else { + WARN_ON(1); + } + node = rb_next(node); + } + spin_unlock(&delayed_refs->lock); + cond_resched(); + goto again; + } +out: + ret = btrfs_delayed_qgroup_accounting(trans, root->fs_info); + if (ret) + return ret; + assert_qgroups_uptodate(trans); + 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 level, int is_data) +{ + struct btrfs_delayed_extent_op *extent_op; + int ret; + + extent_op = btrfs_alloc_delayed_extent_op(); + if (!extent_op) + return -ENOMEM; + + extent_op->flags_to_set = flags; + extent_op->update_flags = 1; + extent_op->update_key = 0; + extent_op->is_data = is_data ? 1 : 0; + extent_op->level = level; + + ret = btrfs_add_delayed_extent_op(root->fs_info, trans, bytenr, + num_bytes, extent_op); + if (ret) + btrfs_free_delayed_extent_op(extent_op); + return ret; +} + +static noinline int check_delayed_ref(struct btrfs_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; + + delayed_refs = &trans->transaction->delayed_refs; + spin_lock(&delayed_refs->lock); + head = btrfs_find_delayed_ref_head(trans, bytenr); + if (!head) { + spin_unlock(&delayed_refs->lock); + return 0; + } + + if (!mutex_trylock(&head->mutex)) { + atomic_inc(&head->node.refs); + spin_unlock(&delayed_refs->lock); + + btrfs_release_path(path); + + /* + * Mutex was contended, block until it's released and let + * caller try again + */ + mutex_lock(&head->mutex); + mutex_unlock(&head->mutex); + btrfs_put_delayed_ref(&head->node); + return -EAGAIN; + } + spin_unlock(&delayed_refs->lock); + + spin_lock(&head->lock); + node = rb_first(&head->ref_root); + while (node) { + ref = rb_entry(node, struct btrfs_delayed_ref_node, rb_node); + node = rb_next(node); + + /* If it's a shared ref we know a cross reference exists */ + if (ref->type != BTRFS_EXTENT_DATA_REF_KEY) { + ret = 1; + break; + } + + data_ref = btrfs_delayed_node_to_data_ref(ref); + + /* + * If our ref doesn't match the one we're currently looking at + * then we have a cross reference. + */ + if (data_ref->root != root->root_key.objectid || + data_ref->objectid != objectid || + data_ref->offset != offset) { + ret = 1; + break; + } + } + spin_unlock(&head->lock); + mutex_unlock(&head->mutex); + 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); /* Corruption */ + + ret = -ENOENT; + if (path->slots[0] == 0) + goto out; + + path->slots[0]--; + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &key, path->slots[0]); + + if (key.objectid != bytenr || key.type != BTRFS_EXTENT_ITEM_KEY) + goto out; + + ret = 1; + item_size = btrfs_item_size_nr(leaf, path->slots[0]); +#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); + if (root->root_key.objectid == BTRFS_DATA_RELOC_TREE_OBJECTID) + WARN_ON(ret > 0); + return ret; +} + +static int __btrfs_mod_ref(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf, + int full_backref, int inc) +{ + 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, int); + + + if (btrfs_test_is_dummy_root(root)) + return 0; + + ref_root = btrfs_header_owner(buf); + nritems = btrfs_header_nritems(buf); + level = btrfs_header_level(buf); + + if (!test_bit(BTRFS_ROOT_REF_COWS, &root->state) && level == 0) + return 0; + + if (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 (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + fi = btrfs_item_ptr(buf, i, + struct btrfs_file_extent_item); + if (btrfs_file_extent_type(buf, fi) == + BTRFS_FILE_EXTENT_INLINE) + continue; + bytenr = btrfs_file_extent_disk_bytenr(buf, fi); + if (bytenr == 0) + continue; + + num_bytes = btrfs_file_extent_disk_num_bytes(buf, fi); + key.offset -= btrfs_file_extent_offset(buf, fi); + ret = process_func(trans, root, bytenr, num_bytes, + parent, ref_root, key.objectid, + key.offset, 1); + if (ret) + goto fail; + } else { + bytenr = btrfs_node_blockptr(buf, i); + num_bytes = root->nodesize; + ret = process_func(trans, root, bytenr, num_bytes, + parent, ref_root, level - 1, 0, + 1); + if (ret) + goto fail; + } + } + return 0; +fail: + return ret; +} + +int btrfs_inc_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *buf, int full_backref) +{ + return __btrfs_mod_ref(trans, root, buf, full_backref, 1); +} + +int btrfs_dec_ref(struct btrfs_trans_handle *trans, struct btrfs_root *root, + struct extent_buffer *buf, int full_backref) +{ + return __btrfs_mod_ref(trans, root, buf, full_backref, 0); +} + +static int write_one_cache_group(struct btrfs_trans_handle *trans, + struct btrfs_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) { + if (ret > 0) + ret = -ENOENT; + goto fail; + } + + leaf = path->nodes[0]; + bi = btrfs_item_ptr_offset(leaf, path->slots[0]); + write_extent_buffer(leaf, &cache->item, bi, sizeof(cache->item)); + btrfs_mark_buffer_dirty(leaf); +fail: + btrfs_release_path(path); + return ret; + +} + +static 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); + + /* If our block group was removed, we need a full search. */ + if (RB_EMPTY_NODE(&cache->cache_node)) { + const u64 next_bytenr = cache->key.objectid + cache->key.offset; + + spin_unlock(&root->fs_info->block_group_cache_lock); + btrfs_put_block_group(cache); + cache = btrfs_lookup_first_block_group(root->fs_info, + next_bytenr); + return cache; + } + 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; +} + +static int cache_save_setup(struct btrfs_block_group_cache *block_group, + struct btrfs_trans_handle *trans, + struct btrfs_path *path) +{ + struct btrfs_root *root = block_group->fs_info->tree_root; + struct inode *inode = NULL; + u64 alloc_hint = 0; + int dcs = BTRFS_DC_ERROR; + u64 num_pages = 0; + int retries = 0; + int ret = 0; + + /* + * If this block group is smaller than 100 megs don't bother caching the + * block group. + */ + if (block_group->key.offset < (100 * 1024 * 1024)) { + spin_lock(&block_group->lock); + block_group->disk_cache_state = BTRFS_DC_WRITTEN; + spin_unlock(&block_group->lock); + return 0; + } + + if (trans->aborted) + return 0; +again: + inode = lookup_free_space_inode(root, block_group, path); + if (IS_ERR(inode) && PTR_ERR(inode) != -ENOENT) { + ret = PTR_ERR(inode); + btrfs_release_path(path); + goto out; + } + + if (IS_ERR(inode)) { + BUG_ON(retries); + retries++; + + if (block_group->ro) + goto out_free; + + ret = create_free_space_inode(root, trans, block_group, path); + if (ret) + goto out_free; + goto again; + } + + /* We've already setup this transaction, go ahead and exit */ + if (block_group->cache_generation == trans->transid && + i_size_read(inode)) { + dcs = BTRFS_DC_SETUP; + goto out_put; + } + + /* + * We want to set the generation to 0, that way if anything goes wrong + * from here on out we know not to trust this cache when we load up next + * time. + */ + BTRFS_I(inode)->generation = 0; + ret = btrfs_update_inode(trans, root, inode); + if (ret) { + /* + * So theoretically we could recover from this, simply set the + * super cache generation to 0 so we know to invalidate the + * cache, but then we'd have to keep track of the block groups + * that fail this way so we know we _have_ to reset this cache + * before the next commit or risk reading stale cache. So to + * limit our exposure to horrible edge cases lets just abort the + * transaction, this only happens in really bad situations + * anyway. + */ + btrfs_abort_transaction(trans, root, ret); + goto out_put; + } + WARN_ON(ret); + + if (i_size_read(inode) > 0) { + ret = btrfs_check_trunc_cache_free_space(root, + &root->fs_info->global_block_rsv); + if (ret) + goto out_put; + + ret = btrfs_truncate_free_space_cache(root, trans, NULL, inode); + if (ret) + goto out_put; + } + + spin_lock(&block_group->lock); + if (block_group->cached != BTRFS_CACHE_FINISHED || + !btrfs_test_opt(root, SPACE_CACHE)) { + /* + * don't bother trying to write stuff out _if_ + * a) we're not cached, + * b) we're with nospace_cache mount option. + */ + dcs = BTRFS_DC_WRITTEN; + spin_unlock(&block_group->lock); + goto out_put; + } + spin_unlock(&block_group->lock); + + /* + * Try to preallocate enough space based on how big the block group is. + * Keep in mind this has to include any pinned space which could end up + * taking up quite a bit since it's not folded into the other space + * cache. + */ + num_pages = div_u64(block_group->key.offset, 256 * 1024 * 1024); + if (!num_pages) + num_pages = 1; + + num_pages *= 16; + num_pages *= PAGE_CACHE_SIZE; + + ret = btrfs_check_data_free_space(inode, num_pages, num_pages); + if (ret) + goto out_put; + + ret = btrfs_prealloc_file_range_trans(inode, trans, 0, 0, num_pages, + num_pages, num_pages, + &alloc_hint); + if (!ret) + dcs = BTRFS_DC_SETUP; + btrfs_free_reserved_data_space(inode, num_pages); + +out_put: + iput(inode); +out_free: + btrfs_release_path(path); +out: + spin_lock(&block_group->lock); + if (!ret && dcs == BTRFS_DC_SETUP) + block_group->cache_generation = trans->transid; + block_group->disk_cache_state = dcs; + spin_unlock(&block_group->lock); + + return ret; +} + +int btrfs_setup_space_cache(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache, *tmp; + struct btrfs_transaction *cur_trans = trans->transaction; + struct btrfs_path *path; + + if (list_empty(&cur_trans->dirty_bgs) || + !btrfs_test_opt(root, SPACE_CACHE)) + return 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* Could add new block groups, use _safe just in case */ + list_for_each_entry_safe(cache, tmp, &cur_trans->dirty_bgs, + dirty_list) { + if (cache->disk_cache_state == BTRFS_DC_CLEAR) + cache_save_setup(cache, trans, path); + } + + btrfs_free_path(path); + return 0; +} + +/* + * transaction commit does final block group cache writeback during a + * critical section where nothing is allowed to change the FS. This is + * required in order for the cache to actually match the block group, + * but can introduce a lot of latency into the commit. + * + * So, btrfs_start_dirty_block_groups is here to kick off block group + * cache IO. There's a chance we'll have to redo some of it if the + * block group changes again during the commit, but it greatly reduces + * the commit latency by getting rid of the easy block groups while + * we're still allowing others to join the commit. + */ +int btrfs_start_dirty_block_groups(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_transaction *cur_trans = trans->transaction; + int ret = 0; + int should_put; + struct btrfs_path *path = NULL; + LIST_HEAD(dirty); + struct list_head *io = &cur_trans->io_bgs; + int num_started = 0; + int loops = 0; + + spin_lock(&cur_trans->dirty_bgs_lock); + if (list_empty(&cur_trans->dirty_bgs)) { + spin_unlock(&cur_trans->dirty_bgs_lock); + return 0; + } + list_splice_init(&cur_trans->dirty_bgs, &dirty); + spin_unlock(&cur_trans->dirty_bgs_lock); + +again: + /* + * make sure all the block groups on our dirty list actually + * exist + */ + btrfs_create_pending_block_groups(trans, root); + + if (!path) { + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + } + + /* + * cache_write_mutex is here only to save us from balance or automatic + * removal of empty block groups deleting this block group while we are + * writing out the cache + */ + mutex_lock(&trans->transaction->cache_write_mutex); + while (!list_empty(&dirty)) { + cache = list_first_entry(&dirty, + struct btrfs_block_group_cache, + dirty_list); + /* + * this can happen if something re-dirties a block + * group that is already under IO. Just wait for it to + * finish and then do it all again + */ + if (!list_empty(&cache->io_list)) { + list_del_init(&cache->io_list); + btrfs_wait_cache_io(root, trans, cache, + &cache->io_ctl, path, + cache->key.objectid); + btrfs_put_block_group(cache); + } + + + /* + * btrfs_wait_cache_io uses the cache->dirty_list to decide + * if it should update the cache_state. Don't delete + * until after we wait. + * + * Since we're not running in the commit critical section + * we need the dirty_bgs_lock to protect from update_block_group + */ + spin_lock(&cur_trans->dirty_bgs_lock); + list_del_init(&cache->dirty_list); + spin_unlock(&cur_trans->dirty_bgs_lock); + + should_put = 1; + + cache_save_setup(cache, trans, path); + + if (cache->disk_cache_state == BTRFS_DC_SETUP) { + cache->io_ctl.inode = NULL; + ret = btrfs_write_out_cache(root, trans, cache, path); + if (ret == 0 && cache->io_ctl.inode) { + num_started++; + should_put = 0; + + /* + * the cache_write_mutex is protecting + * the io_list + */ + list_add_tail(&cache->io_list, io); + } else { + /* + * if we failed to write the cache, the + * generation will be bad and life goes on + */ + ret = 0; + } + } + if (!ret) { + ret = write_one_cache_group(trans, root, path, cache); + /* + * Our block group might still be attached to the list + * of new block groups in the transaction handle of some + * other task (struct btrfs_trans_handle->new_bgs). This + * means its block group item isn't yet in the extent + * tree. If this happens ignore the error, as we will + * try again later in the critical section of the + * transaction commit. + */ + if (ret == -ENOENT) { + ret = 0; + spin_lock(&cur_trans->dirty_bgs_lock); + if (list_empty(&cache->dirty_list)) { + list_add_tail(&cache->dirty_list, + &cur_trans->dirty_bgs); + btrfs_get_block_group(cache); + } + spin_unlock(&cur_trans->dirty_bgs_lock); + } else if (ret) { + btrfs_abort_transaction(trans, root, ret); + } + } + + /* if its not on the io list, we need to put the block group */ + if (should_put) + btrfs_put_block_group(cache); + + if (ret) + break; + + /* + * Avoid blocking other tasks for too long. It might even save + * us from writing caches for block groups that are going to be + * removed. + */ + mutex_unlock(&trans->transaction->cache_write_mutex); + mutex_lock(&trans->transaction->cache_write_mutex); + } + mutex_unlock(&trans->transaction->cache_write_mutex); + + /* + * go through delayed refs for all the stuff we've just kicked off + * and then loop back (just once) + */ + ret = btrfs_run_delayed_refs(trans, root, 0); + if (!ret && loops == 0) { + loops++; + spin_lock(&cur_trans->dirty_bgs_lock); + list_splice_init(&cur_trans->dirty_bgs, &dirty); + /* + * dirty_bgs_lock protects us from concurrent block group + * deletes too (not just cache_write_mutex). + */ + if (!list_empty(&dirty)) { + spin_unlock(&cur_trans->dirty_bgs_lock); + goto again; + } + spin_unlock(&cur_trans->dirty_bgs_lock); + } + + btrfs_free_path(path); + return ret; +} + +int btrfs_write_dirty_block_groups(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *cache; + struct btrfs_transaction *cur_trans = trans->transaction; + int ret = 0; + int should_put; + struct btrfs_path *path; + struct list_head *io = &cur_trans->io_bgs; + int num_started = 0; + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * We don't need the lock here since we are protected by the transaction + * commit. We want to do the cache_save_setup first and then run the + * delayed refs to make sure we have the best chance at doing this all + * in one shot. + */ + while (!list_empty(&cur_trans->dirty_bgs)) { + cache = list_first_entry(&cur_trans->dirty_bgs, + struct btrfs_block_group_cache, + dirty_list); + + /* + * this can happen if cache_save_setup re-dirties a block + * group that is already under IO. Just wait for it to + * finish and then do it all again + */ + if (!list_empty(&cache->io_list)) { + list_del_init(&cache->io_list); + btrfs_wait_cache_io(root, trans, cache, + &cache->io_ctl, path, + cache->key.objectid); + btrfs_put_block_group(cache); + } + + /* + * don't remove from the dirty list until after we've waited + * on any pending IO + */ + list_del_init(&cache->dirty_list); + should_put = 1; + + cache_save_setup(cache, trans, path); + + if (!ret) + ret = btrfs_run_delayed_refs(trans, root, (unsigned long) -1); + + if (!ret && cache->disk_cache_state == BTRFS_DC_SETUP) { + cache->io_ctl.inode = NULL; + ret = btrfs_write_out_cache(root, trans, cache, path); + if (ret == 0 && cache->io_ctl.inode) { + num_started++; + should_put = 0; + list_add_tail(&cache->io_list, io); + } else { + /* + * if we failed to write the cache, the + * generation will be bad and life goes on + */ + ret = 0; + } + } + if (!ret) { + ret = write_one_cache_group(trans, root, path, cache); + if (ret) + btrfs_abort_transaction(trans, root, ret); + } + + /* if its not on the io list, we need to put the block group */ + if (should_put) + btrfs_put_block_group(cache); + } + + while (!list_empty(io)) { + cache = list_first_entry(io, struct btrfs_block_group_cache, + io_list); + list_del_init(&cache->io_list); + btrfs_wait_cache_io(root, trans, cache, + &cache->io_ctl, path, cache->key.objectid); + btrfs_put_block_group(cache); + } + + btrfs_free_path(path); + return ret; +} + +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 const char *alloc_name(u64 flags) +{ + switch (flags) { + case BTRFS_BLOCK_GROUP_METADATA|BTRFS_BLOCK_GROUP_DATA: + return "mixed"; + case BTRFS_BLOCK_GROUP_METADATA: + return "metadata"; + case BTRFS_BLOCK_GROUP_DATA: + return "data"; + case BTRFS_BLOCK_GROUP_SYSTEM: + return "system"; + default: + WARN_ON(1); + return "invalid-combination"; + }; +} + +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; + int i; + int factor; + int ret; + + if (flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + factor = 2; + else + factor = 1; + + found = __find_space_info(info, flags); + if (found) { + spin_lock(&found->lock); + found->total_bytes += total_bytes; + found->disk_total += total_bytes * factor; + found->bytes_used += bytes_used; + found->disk_used += bytes_used * factor; + found->full = 0; + spin_unlock(&found->lock); + *space_info = found; + return 0; + } + found = kzalloc(sizeof(*found), GFP_NOFS); + if (!found) + return -ENOMEM; + + ret = percpu_counter_init(&found->total_bytes_pinned, 0, GFP_KERNEL); + if (ret) { + kfree(found); + return ret; + } + + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) + INIT_LIST_HEAD(&found->block_groups[i]); + init_rwsem(&found->groups_sem); + spin_lock_init(&found->lock); + found->flags = flags & BTRFS_BLOCK_GROUP_TYPE_MASK; + found->total_bytes = total_bytes; + found->disk_total = total_bytes * factor; + found->bytes_used = bytes_used; + found->disk_used = bytes_used * factor; + found->bytes_pinned = 0; + found->bytes_reserved = 0; + found->bytes_readonly = 0; + found->bytes_may_use = 0; + found->full = 0; + found->force_alloc = CHUNK_ALLOC_NO_FORCE; + found->chunk_alloc = 0; + found->flush = 0; + init_waitqueue_head(&found->wait); + INIT_LIST_HEAD(&found->ro_bgs); + + ret = kobject_init_and_add(&found->kobj, &space_info_ktype, + info->space_info_kobj, "%s", + alloc_name(found->flags)); + if (ret) { + kfree(found); + return ret; + } + + *space_info = found; + list_add_rcu(&found->list, &info->space_info); + if (flags & BTRFS_BLOCK_GROUP_DATA) + info->data_sinfo = found; + + return ret; +} + +static void set_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) +{ + u64 extra_flags = chunk_to_extended(flags) & + BTRFS_EXTENDED_PROFILE_MASK; + + write_seqlock(&fs_info->profiles_lock); + if (flags & BTRFS_BLOCK_GROUP_DATA) + fs_info->avail_data_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_METADATA) + fs_info->avail_metadata_alloc_bits |= extra_flags; + if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + fs_info->avail_system_alloc_bits |= extra_flags; + write_sequnlock(&fs_info->profiles_lock); +} + +/* + * returns target flags in extended format or 0 if restripe for this + * chunk_type is not in progress + * + * should be called with either volume_mutex or balance_lock held + */ +static u64 get_restripe_target(struct btrfs_fs_info *fs_info, u64 flags) +{ + struct btrfs_balance_control *bctl = fs_info->balance_ctl; + u64 target = 0; + + if (!bctl) + return 0; + + if (flags & BTRFS_BLOCK_GROUP_DATA && + bctl->data.flags & BTRFS_BALANCE_ARGS_CONVERT) { + target = BTRFS_BLOCK_GROUP_DATA | bctl->data.target; + } else if (flags & BTRFS_BLOCK_GROUP_SYSTEM && + bctl->sys.flags & BTRFS_BALANCE_ARGS_CONVERT) { + target = BTRFS_BLOCK_GROUP_SYSTEM | bctl->sys.target; + } else if (flags & BTRFS_BLOCK_GROUP_METADATA && + bctl->meta.flags & BTRFS_BALANCE_ARGS_CONVERT) { + target = BTRFS_BLOCK_GROUP_METADATA | bctl->meta.target; + } + + return target; +} + +/* + * @flags: available profiles in extended format (see ctree.h) + * + * Returns reduced profile in chunk format. If profile changing is in + * progress (either running or paused) picks the target profile (if it's + * already available), otherwise falls back to plain reducing. + */ +static u64 btrfs_reduce_alloc_profile(struct btrfs_root *root, u64 flags) +{ + u64 num_devices = root->fs_info->fs_devices->rw_devices; + u64 target; + u64 tmp; + + /* + * see if restripe for this chunk_type is in progress, if so + * try to reduce to the target profile + */ + spin_lock(&root->fs_info->balance_lock); + target = get_restripe_target(root->fs_info, flags); + if (target) { + /* pick target profile only if it's already available */ + if ((flags & target) & BTRFS_EXTENDED_PROFILE_MASK) { + spin_unlock(&root->fs_info->balance_lock); + return extended_to_chunk(target); + } + } + spin_unlock(&root->fs_info->balance_lock); + + /* First, mask out the RAID levels which aren't possible */ + if (num_devices == 1) + flags &= ~(BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID5); + if (num_devices < 3) + flags &= ~BTRFS_BLOCK_GROUP_RAID6; + if (num_devices < 4) + flags &= ~BTRFS_BLOCK_GROUP_RAID10; + + tmp = flags & (BTRFS_BLOCK_GROUP_DUP | BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6 | BTRFS_BLOCK_GROUP_RAID10); + flags &= ~tmp; + + if (tmp & BTRFS_BLOCK_GROUP_RAID6) + tmp = BTRFS_BLOCK_GROUP_RAID6; + else if (tmp & BTRFS_BLOCK_GROUP_RAID5) + tmp = BTRFS_BLOCK_GROUP_RAID5; + else if (tmp & BTRFS_BLOCK_GROUP_RAID10) + tmp = BTRFS_BLOCK_GROUP_RAID10; + else if (tmp & BTRFS_BLOCK_GROUP_RAID1) + tmp = BTRFS_BLOCK_GROUP_RAID1; + else if (tmp & BTRFS_BLOCK_GROUP_RAID0) + tmp = BTRFS_BLOCK_GROUP_RAID0; + + return extended_to_chunk(flags | tmp); +} + +static u64 get_alloc_profile(struct btrfs_root *root, u64 orig_flags) +{ + unsigned seq; + u64 flags; + + do { + flags = orig_flags; + seq = read_seqbegin(&root->fs_info->profiles_lock); + + if (flags & BTRFS_BLOCK_GROUP_DATA) + flags |= root->fs_info->avail_data_alloc_bits; + else if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + flags |= root->fs_info->avail_system_alloc_bits; + else if (flags & BTRFS_BLOCK_GROUP_METADATA) + flags |= root->fs_info->avail_metadata_alloc_bits; + } while (read_seqretry(&root->fs_info->profiles_lock, seq)); + + return btrfs_reduce_alloc_profile(root, flags); +} + +u64 btrfs_get_alloc_profile(struct btrfs_root *root, int data) +{ + u64 flags; + u64 ret; + + if (data) + flags = BTRFS_BLOCK_GROUP_DATA; + else if (root == root->fs_info->chunk_root) + flags = BTRFS_BLOCK_GROUP_SYSTEM; + else + flags = BTRFS_BLOCK_GROUP_METADATA; + + ret = get_alloc_profile(root, flags); + return ret; +} + +/* + * 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 inode *inode, u64 bytes, u64 write_bytes) +{ + struct btrfs_space_info *data_sinfo; + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_fs_info *fs_info = root->fs_info; + u64 used; + int ret = 0; + int need_commit = 2; + int have_pinned_space; + + /* make sure bytes are sectorsize aligned */ + bytes = ALIGN(bytes, root->sectorsize); + + if (btrfs_is_free_space_inode(inode)) { + need_commit = 0; + ASSERT(current->journal_info); + } + + data_sinfo = fs_info->data_sinfo; + 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_reserved + + data_sinfo->bytes_pinned + data_sinfo->bytes_readonly + + data_sinfo->bytes_may_use; + + if (used + bytes > data_sinfo->total_bytes) { + struct btrfs_trans_handle *trans; + + /* + * 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 = CHUNK_ALLOC_FORCE; + spin_unlock(&data_sinfo->lock); +alloc: + alloc_target = btrfs_get_alloc_profile(root, 1); + /* + * It is ugly that we don't call nolock join + * transaction for the free space inode case here. + * But it is safe because we only do the data space + * reservation for the free space cache in the + * transaction context, the common join transaction + * just increase the counter of the current transaction + * handler, doesn't try to acquire the trans_lock of + * the fs. + */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + alloc_target, + CHUNK_ALLOC_NO_FORCE); + btrfs_end_transaction(trans, root); + if (ret < 0) { + if (ret != -ENOSPC) + return ret; + else { + have_pinned_space = 1; + goto commit_trans; + } + } + + if (!data_sinfo) + data_sinfo = fs_info->data_sinfo; + + goto again; + } + + /* + * If we don't have enough pinned space to deal with this + * allocation, and no removed chunk in current transaction, + * don't bother committing the transaction. + */ + have_pinned_space = percpu_counter_compare( + &data_sinfo->total_bytes_pinned, + used + bytes - data_sinfo->total_bytes); + spin_unlock(&data_sinfo->lock); + + /* commit the current transaction and try again */ +commit_trans: + if (need_commit && + !atomic_read(&root->fs_info->open_ioctl_trans)) { + need_commit--; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + if (have_pinned_space >= 0 || + trans->transaction->have_free_bgs || + need_commit > 0) { + ret = btrfs_commit_transaction(trans, root); + if (ret) + return ret; + /* + * make sure that all running delayed iput are + * done + */ + down_write(&root->fs_info->delayed_iput_sem); + up_write(&root->fs_info->delayed_iput_sem); + goto again; + } else { + btrfs_end_transaction(trans, root); + } + } + + trace_btrfs_space_reservation(root->fs_info, + "space_info:enospc", + data_sinfo->flags, bytes, 1); + return -ENOSPC; + } + ret = btrfs_qgroup_reserve(root, write_bytes); + if (ret) + goto out; + data_sinfo->bytes_may_use += bytes; + trace_btrfs_space_reservation(root->fs_info, "space_info", + data_sinfo->flags, bytes, 1); +out: + spin_unlock(&data_sinfo->lock); + + return ret; +} + +/* + * Called if we need to clear a data reservation for this inode. + */ +void btrfs_free_reserved_data_space(struct inode *inode, u64 bytes) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_space_info *data_sinfo; + + /* make sure bytes are sectorsize aligned */ + bytes = ALIGN(bytes, root->sectorsize); + + data_sinfo = root->fs_info->data_sinfo; + spin_lock(&data_sinfo->lock); + WARN_ON(data_sinfo->bytes_may_use < bytes); + data_sinfo->bytes_may_use -= bytes; + trace_btrfs_space_reservation(root->fs_info, "space_info", + data_sinfo->flags, bytes, 0); + spin_unlock(&data_sinfo->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 = CHUNK_ALLOC_FORCE; + } + rcu_read_unlock(); +} + +static inline u64 calc_global_rsv_need_space(struct btrfs_block_rsv *global) +{ + return (global->size << 1); +} + +static int should_alloc_chunk(struct btrfs_root *root, + struct btrfs_space_info *sinfo, int force) +{ + struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; + u64 num_bytes = sinfo->total_bytes - sinfo->bytes_readonly; + u64 num_allocated = sinfo->bytes_used + sinfo->bytes_reserved; + u64 thresh; + + if (force == CHUNK_ALLOC_FORCE) + return 1; + + /* + * We need to take into account the global rsv because for all intents + * and purposes it's used space. Don't worry about locking the + * global_rsv, it doesn't change except when the transaction commits. + */ + if (sinfo->flags & BTRFS_BLOCK_GROUP_METADATA) + num_allocated += calc_global_rsv_need_space(global_rsv); + + /* + * in limited mode, we want to have some free space up to + * about 1% of the FS size. + */ + if (force == CHUNK_ALLOC_LIMITED) { + thresh = btrfs_super_total_bytes(root->fs_info->super_copy); + thresh = max_t(u64, 64 * 1024 * 1024, + div_factor_fine(thresh, 1)); + + if (num_bytes - num_allocated < thresh) + return 1; + } + + if (num_allocated + 2 * 1024 * 1024 < div_factor(num_bytes, 8)) + return 0; + return 1; +} + +static u64 get_system_chunk_thresh(struct btrfs_root *root, u64 type) +{ + u64 num_dev; + + if (type & (BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6)) + num_dev = root->fs_info->fs_devices->rw_devices; + else if (type & BTRFS_BLOCK_GROUP_RAID1) + num_dev = 2; + else + num_dev = 1; /* DUP or single */ + + /* metadata for updaing devices and chunk tree */ + return btrfs_calc_trans_metadata_size(root, num_dev + 1); +} + +static void check_system_chunk(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 type) +{ + struct btrfs_space_info *info; + u64 left; + u64 thresh; + + info = __find_space_info(root->fs_info, BTRFS_BLOCK_GROUP_SYSTEM); + spin_lock(&info->lock); + left = info->total_bytes - info->bytes_used - info->bytes_pinned - + info->bytes_reserved - info->bytes_readonly; + spin_unlock(&info->lock); + + thresh = get_system_chunk_thresh(root, type); + if (left < thresh && btrfs_test_opt(root, ENOSPC_DEBUG)) { + btrfs_info(root->fs_info, "left=%llu, need=%llu, flags=%llu", + left, thresh, type); + dump_space_info(info, 0, 0); + } + + if (left < thresh) { + u64 flags; + + flags = btrfs_get_alloc_profile(root->fs_info->chunk_root, 0); + btrfs_alloc_chunk(trans, root, flags); + } +} + +static int do_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *extent_root, u64 flags, int force) +{ + struct btrfs_space_info *space_info; + struct btrfs_fs_info *fs_info = extent_root->fs_info; + int wait_for_alloc = 0; + int ret = 0; + + /* Don't re-enter if we're already allocating a chunk */ + if (trans->allocating_chunk) + return -ENOSPC; + + 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); /* -ENOMEM */ + } + BUG_ON(!space_info); /* Logic error */ + +again: + spin_lock(&space_info->lock); + if (force < space_info->force_alloc) + force = space_info->force_alloc; + if (space_info->full) { + if (should_alloc_chunk(extent_root, space_info, force)) + ret = -ENOSPC; + else + ret = 0; + spin_unlock(&space_info->lock); + return ret; + } + + if (!should_alloc_chunk(extent_root, space_info, force)) { + spin_unlock(&space_info->lock); + return 0; + } else if (space_info->chunk_alloc) { + wait_for_alloc = 1; + } else { + space_info->chunk_alloc = 1; + } + + spin_unlock(&space_info->lock); + + mutex_lock(&fs_info->chunk_mutex); + + /* + * The chunk_mutex is held throughout the entirety of a chunk + * allocation, so once we've acquired the chunk_mutex we know that the + * other guy is done and we need to recheck and see if we should + * allocate. + */ + if (wait_for_alloc) { + mutex_unlock(&fs_info->chunk_mutex); + wait_for_alloc = 0; + goto again; + } + + trans->allocating_chunk = true; + + /* + * If we have mixed data/metadata chunks we want to make sure we keep + * allocating mixed chunks instead of individual chunks. + */ + if (btrfs_mixed_space_info(space_info)) + flags |= (BTRFS_BLOCK_GROUP_DATA | BTRFS_BLOCK_GROUP_METADATA); + + /* + * if we're doing a data chunk, go ahead and make sure that + * we keep a reasonable number of metadata chunks allocated in the + * FS as well. + */ + if (flags & BTRFS_BLOCK_GROUP_DATA && fs_info->metadata_ratio) { + fs_info->data_chunk_allocations++; + if (!(fs_info->data_chunk_allocations % + fs_info->metadata_ratio)) + force_metadata_allocation(fs_info); + } + + /* + * Check if we have enough space in SYSTEM chunk because we may need + * to update devices. + */ + check_system_chunk(trans, extent_root, flags); + + ret = btrfs_alloc_chunk(trans, extent_root, flags); + trans->allocating_chunk = false; + + spin_lock(&space_info->lock); + if (ret < 0 && ret != -ENOSPC) + goto out; + if (ret) + space_info->full = 1; + else + ret = 1; + + space_info->force_alloc = CHUNK_ALLOC_NO_FORCE; +out: + space_info->chunk_alloc = 0; + spin_unlock(&space_info->lock); + mutex_unlock(&fs_info->chunk_mutex); + return ret; +} + +static int can_overcommit(struct btrfs_root *root, + struct btrfs_space_info *space_info, u64 bytes, + enum btrfs_reserve_flush_enum flush) +{ + struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; + u64 profile = btrfs_get_alloc_profile(root, 0); + u64 space_size; + u64 avail; + u64 used; + + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly; + + /* + * We only want to allow over committing if we have lots of actual space + * free, but if we don't have enough space to handle the global reserve + * space then we could end up having a real enospc problem when trying + * to allocate a chunk or some other such important allocation. + */ + spin_lock(&global_rsv->lock); + space_size = calc_global_rsv_need_space(global_rsv); + spin_unlock(&global_rsv->lock); + if (used + space_size >= space_info->total_bytes) + return 0; + + used += space_info->bytes_may_use; + + spin_lock(&root->fs_info->free_chunk_lock); + avail = root->fs_info->free_chunk_space; + spin_unlock(&root->fs_info->free_chunk_lock); + + /* + * If we have dup, raid1 or raid10 then only half of the free + * space is actually useable. For raid56, the space info used + * doesn't include the parity drive, so we don't have to + * change the math + */ + if (profile & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + avail >>= 1; + + /* + * If we aren't flushing all things, let us overcommit up to + * 1/2th of the space. If we can flush, don't let us overcommit + * too much, let it overcommit up to 1/8 of the space. + */ + if (flush == BTRFS_RESERVE_FLUSH_ALL) + avail >>= 3; + else + avail >>= 1; + + if (used + bytes < space_info->total_bytes + avail) + return 1; + return 0; +} + +static void btrfs_writeback_inodes_sb_nr(struct btrfs_root *root, + unsigned long nr_pages, int nr_items) +{ + struct super_block *sb = root->fs_info->sb; + + if (down_read_trylock(&sb->s_umount)) { + writeback_inodes_sb_nr(sb, nr_pages, WB_REASON_FS_FREE_SPACE); + up_read(&sb->s_umount); + } else { + /* + * We needn't worry the filesystem going from r/w to r/o though + * we don't acquire ->s_umount mutex, because the filesystem + * should guarantee the delalloc inodes list be empty after + * the filesystem is readonly(all dirty pages are written to + * the disk). + */ + btrfs_start_delalloc_roots(root->fs_info, 0, nr_items); + if (!current->journal_info) + btrfs_wait_ordered_roots(root->fs_info, nr_items); + } +} + +static inline int calc_reclaim_items_nr(struct btrfs_root *root, u64 to_reclaim) +{ + u64 bytes; + int nr; + + bytes = btrfs_calc_trans_metadata_size(root, 1); + nr = (int)div64_u64(to_reclaim, bytes); + if (!nr) + nr = 1; + return nr; +} + +#define EXTENT_SIZE_PER_ITEM (256 * 1024) + +/* + * shrink metadata reservation for delalloc + */ +static void shrink_delalloc(struct btrfs_root *root, u64 to_reclaim, u64 orig, + bool wait_ordered) +{ + struct btrfs_block_rsv *block_rsv; + struct btrfs_space_info *space_info; + struct btrfs_trans_handle *trans; + u64 delalloc_bytes; + u64 max_reclaim; + long time_left; + unsigned long nr_pages; + int loops; + int items; + enum btrfs_reserve_flush_enum flush; + + /* Calc the number of the pages we need flush for space reservation */ + items = calc_reclaim_items_nr(root, to_reclaim); + to_reclaim = items * EXTENT_SIZE_PER_ITEM; + + trans = (struct btrfs_trans_handle *)current->journal_info; + block_rsv = &root->fs_info->delalloc_block_rsv; + space_info = block_rsv->space_info; + + delalloc_bytes = percpu_counter_sum_positive( + &root->fs_info->delalloc_bytes); + if (delalloc_bytes == 0) { + if (trans) + return; + if (wait_ordered) + btrfs_wait_ordered_roots(root->fs_info, items); + return; + } + + loops = 0; + while (delalloc_bytes && loops < 3) { + max_reclaim = min(delalloc_bytes, to_reclaim); + nr_pages = max_reclaim >> PAGE_CACHE_SHIFT; + btrfs_writeback_inodes_sb_nr(root, nr_pages, items); + /* + * We need to wait for the async pages to actually start before + * we do anything. + */ + max_reclaim = atomic_read(&root->fs_info->async_delalloc_pages); + if (!max_reclaim) + goto skip_async; + + if (max_reclaim <= nr_pages) + max_reclaim = 0; + else + max_reclaim -= nr_pages; + + wait_event(root->fs_info->async_submit_wait, + atomic_read(&root->fs_info->async_delalloc_pages) <= + (int)max_reclaim); +skip_async: + if (!trans) + flush = BTRFS_RESERVE_FLUSH_ALL; + else + flush = BTRFS_RESERVE_NO_FLUSH; + spin_lock(&space_info->lock); + if (can_overcommit(root, space_info, orig, flush)) { + spin_unlock(&space_info->lock); + break; + } + spin_unlock(&space_info->lock); + + loops++; + if (wait_ordered && !trans) { + btrfs_wait_ordered_roots(root->fs_info, items); + } else { + time_left = schedule_timeout_killable(1); + if (time_left) + break; + } + delalloc_bytes = percpu_counter_sum_positive( + &root->fs_info->delalloc_bytes); + } +} + +/** + * maybe_commit_transaction - possibly commit the transaction if its ok to + * @root - the root we're allocating for + * @bytes - the number of bytes we want to reserve + * @force - force the commit + * + * This will check to make sure that committing the transaction will actually + * get us somewhere and then commit the transaction if it does. Otherwise it + * will return -ENOSPC. + */ +static int may_commit_transaction(struct btrfs_root *root, + struct btrfs_space_info *space_info, + u64 bytes, int force) +{ + struct btrfs_block_rsv *delayed_rsv = &root->fs_info->delayed_block_rsv; + struct btrfs_trans_handle *trans; + + trans = (struct btrfs_trans_handle *)current->journal_info; + if (trans) + return -EAGAIN; + + if (force) + goto commit; + + /* See if there is enough pinned space to make this reservation */ + if (percpu_counter_compare(&space_info->total_bytes_pinned, + bytes) >= 0) + goto commit; + + /* + * See if there is some space in the delayed insertion reservation for + * this reservation. + */ + if (space_info != delayed_rsv->space_info) + return -ENOSPC; + + spin_lock(&delayed_rsv->lock); + if (percpu_counter_compare(&space_info->total_bytes_pinned, + bytes - delayed_rsv->size) >= 0) { + spin_unlock(&delayed_rsv->lock); + return -ENOSPC; + } + spin_unlock(&delayed_rsv->lock); + +commit: + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return -ENOSPC; + + return btrfs_commit_transaction(trans, root); +} + +enum flush_state { + FLUSH_DELAYED_ITEMS_NR = 1, + FLUSH_DELAYED_ITEMS = 2, + FLUSH_DELALLOC = 3, + FLUSH_DELALLOC_WAIT = 4, + ALLOC_CHUNK = 5, + COMMIT_TRANS = 6, +}; + +static int flush_space(struct btrfs_root *root, + struct btrfs_space_info *space_info, u64 num_bytes, + u64 orig_bytes, int state) +{ + struct btrfs_trans_handle *trans; + int nr; + int ret = 0; + + switch (state) { + case FLUSH_DELAYED_ITEMS_NR: + case FLUSH_DELAYED_ITEMS: + if (state == FLUSH_DELAYED_ITEMS_NR) + nr = calc_reclaim_items_nr(root, num_bytes) * 2; + else + nr = -1; + + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + ret = btrfs_run_delayed_items_nr(trans, root, nr); + btrfs_end_transaction(trans, root); + break; + case FLUSH_DELALLOC: + case FLUSH_DELALLOC_WAIT: + shrink_delalloc(root, num_bytes * 2, orig_bytes, + state == FLUSH_DELALLOC_WAIT); + break; + case ALLOC_CHUNK: + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + break; + } + ret = do_chunk_alloc(trans, root->fs_info->extent_root, + btrfs_get_alloc_profile(root, 0), + CHUNK_ALLOC_NO_FORCE); + btrfs_end_transaction(trans, root); + if (ret == -ENOSPC) + ret = 0; + break; + case COMMIT_TRANS: + ret = may_commit_transaction(root, space_info, orig_bytes, 0); + break; + default: + ret = -ENOSPC; + break; + } + + return ret; +} + +static inline u64 +btrfs_calc_reclaim_metadata_size(struct btrfs_root *root, + struct btrfs_space_info *space_info) +{ + u64 used; + u64 expected; + u64 to_reclaim; + + to_reclaim = min_t(u64, num_online_cpus() * 1024 * 1024, + 16 * 1024 * 1024); + spin_lock(&space_info->lock); + if (can_overcommit(root, space_info, to_reclaim, + BTRFS_RESERVE_FLUSH_ALL)) { + to_reclaim = 0; + goto out; + } + + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly + + space_info->bytes_may_use; + if (can_overcommit(root, space_info, 1024 * 1024, + BTRFS_RESERVE_FLUSH_ALL)) + expected = div_factor_fine(space_info->total_bytes, 95); + else + expected = div_factor_fine(space_info->total_bytes, 90); + + if (used > expected) + to_reclaim = used - expected; + else + to_reclaim = 0; + to_reclaim = min(to_reclaim, space_info->bytes_may_use + + space_info->bytes_reserved); +out: + spin_unlock(&space_info->lock); + + return to_reclaim; +} + +static inline int need_do_async_reclaim(struct btrfs_space_info *space_info, + struct btrfs_fs_info *fs_info, u64 used) +{ + u64 thresh = div_factor_fine(space_info->total_bytes, 98); + + /* If we're just plain full then async reclaim just slows us down. */ + if (space_info->bytes_used >= thresh) + return 0; + + return (used >= thresh && !btrfs_fs_closing(fs_info) && + !test_bit(BTRFS_FS_STATE_REMOUNTING, &fs_info->fs_state)); +} + +static int btrfs_need_do_async_reclaim(struct btrfs_space_info *space_info, + struct btrfs_fs_info *fs_info, + int flush_state) +{ + u64 used; + + spin_lock(&space_info->lock); + /* + * We run out of space and have not got any free space via flush_space, + * so don't bother doing async reclaim. + */ + if (flush_state > COMMIT_TRANS && space_info->full) { + spin_unlock(&space_info->lock); + return 0; + } + + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly + + space_info->bytes_may_use; + if (need_do_async_reclaim(space_info, fs_info, used)) { + spin_unlock(&space_info->lock); + return 1; + } + spin_unlock(&space_info->lock); + + return 0; +} + +static void btrfs_async_reclaim_metadata_space(struct work_struct *work) +{ + struct btrfs_fs_info *fs_info; + struct btrfs_space_info *space_info; + u64 to_reclaim; + int flush_state; + + fs_info = container_of(work, struct btrfs_fs_info, async_reclaim_work); + space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + + to_reclaim = btrfs_calc_reclaim_metadata_size(fs_info->fs_root, + space_info); + if (!to_reclaim) + return; + + flush_state = FLUSH_DELAYED_ITEMS_NR; + do { + flush_space(fs_info->fs_root, space_info, to_reclaim, + to_reclaim, flush_state); + flush_state++; + if (!btrfs_need_do_async_reclaim(space_info, fs_info, + flush_state)) + return; + } while (flush_state < COMMIT_TRANS); +} + +void btrfs_init_async_reclaim_work(struct work_struct *work) +{ + INIT_WORK(work, btrfs_async_reclaim_metadata_space); +} + +/** + * reserve_metadata_bytes - try to reserve bytes from the block_rsv's space + * @root - the root we're allocating for + * @block_rsv - the block_rsv we're allocating for + * @orig_bytes - the number of bytes we want + * @flush - whether or not we can flush to make our reservation + * + * This will reserve orgi_bytes number of bytes from the space info associated + * with the block_rsv. If there is not enough space it will make an attempt to + * flush out space to make room. It will do this by flushing delalloc if + * possible or committing the transaction. If flush is 0 then no attempts to + * regain reservations will be made and this will fail if there is not enough + * space already. + */ +static int reserve_metadata_bytes(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, + u64 orig_bytes, + enum btrfs_reserve_flush_enum flush) +{ + struct btrfs_space_info *space_info = block_rsv->space_info; + u64 used; + u64 num_bytes = orig_bytes; + int flush_state = FLUSH_DELAYED_ITEMS_NR; + int ret = 0; + bool flushing = false; + +again: + ret = 0; + spin_lock(&space_info->lock); + /* + * We only want to wait if somebody other than us is flushing and we + * are actually allowed to flush all things. + */ + while (flush == BTRFS_RESERVE_FLUSH_ALL && !flushing && + space_info->flush) { + spin_unlock(&space_info->lock); + /* + * If we have a trans handle we can't wait because the flusher + * may have to commit the transaction, which would mean we would + * deadlock since we are waiting for the flusher to finish, but + * hold the current transaction open. + */ + if (current->journal_info) + return -EAGAIN; + ret = wait_event_killable(space_info->wait, !space_info->flush); + /* Must have been killed, return */ + if (ret) + return -EINTR; + + spin_lock(&space_info->lock); + } + + ret = -ENOSPC; + used = space_info->bytes_used + space_info->bytes_reserved + + space_info->bytes_pinned + space_info->bytes_readonly + + space_info->bytes_may_use; + + /* + * The idea here is that we've not already over-reserved the block group + * then we can go ahead and save our reservation first and then start + * flushing if we need to. Otherwise if we've already overcommitted + * lets start flushing stuff first and then come back and try to make + * our reservation. + */ + if (used <= space_info->total_bytes) { + if (used + orig_bytes <= space_info->total_bytes) { + space_info->bytes_may_use += orig_bytes; + trace_btrfs_space_reservation(root->fs_info, + "space_info", space_info->flags, orig_bytes, 1); + ret = 0; + } else { + /* + * Ok set num_bytes to orig_bytes since we aren't + * overocmmitted, this way we only try and reclaim what + * we need. + */ + num_bytes = orig_bytes; + } + } else { + /* + * Ok we're over committed, set num_bytes to the overcommitted + * amount plus the amount of bytes that we need for this + * reservation. + */ + num_bytes = used - space_info->total_bytes + + (orig_bytes * 2); + } + + if (ret && can_overcommit(root, space_info, orig_bytes, flush)) { + space_info->bytes_may_use += orig_bytes; + trace_btrfs_space_reservation(root->fs_info, "space_info", + space_info->flags, orig_bytes, + 1); + ret = 0; + } + + /* + * Couldn't make our reservation, save our place so while we're trying + * to reclaim space we can actually use it instead of somebody else + * stealing it from us. + * + * We make the other tasks wait for the flush only when we can flush + * all things. + */ + if (ret && flush != BTRFS_RESERVE_NO_FLUSH) { + flushing = true; + space_info->flush = 1; + } else if (!ret && space_info->flags & BTRFS_BLOCK_GROUP_METADATA) { + used += orig_bytes; + /* + * We will do the space reservation dance during log replay, + * which means we won't have fs_info->fs_root set, so don't do + * the async reclaim as we will panic. + */ + if (!root->fs_info->log_root_recovering && + need_do_async_reclaim(space_info, root->fs_info, used) && + !work_busy(&root->fs_info->async_reclaim_work)) + queue_work(system_unbound_wq, + &root->fs_info->async_reclaim_work); + } + spin_unlock(&space_info->lock); + + if (!ret || flush == BTRFS_RESERVE_NO_FLUSH) + goto out; + + ret = flush_space(root, space_info, num_bytes, orig_bytes, + flush_state); + flush_state++; + + /* + * If we are FLUSH_LIMIT, we can not flush delalloc, or the deadlock + * would happen. So skip delalloc flush. + */ + if (flush == BTRFS_RESERVE_FLUSH_LIMIT && + (flush_state == FLUSH_DELALLOC || + flush_state == FLUSH_DELALLOC_WAIT)) + flush_state = ALLOC_CHUNK; + + if (!ret) + goto again; + else if (flush == BTRFS_RESERVE_FLUSH_LIMIT && + flush_state < COMMIT_TRANS) + goto again; + else if (flush == BTRFS_RESERVE_FLUSH_ALL && + flush_state <= COMMIT_TRANS) + goto again; + +out: + if (ret == -ENOSPC && + unlikely(root->orphan_cleanup_state == ORPHAN_CLEANUP_STARTED)) { + struct btrfs_block_rsv *global_rsv = + &root->fs_info->global_block_rsv; + + if (block_rsv != global_rsv && + !block_rsv_use_bytes(global_rsv, orig_bytes)) + ret = 0; + } + if (ret == -ENOSPC) + trace_btrfs_space_reservation(root->fs_info, + "space_info:enospc", + space_info->flags, orig_bytes, 1); + if (flushing) { + spin_lock(&space_info->lock); + space_info->flush = 0; + wake_up_all(&space_info->wait); + spin_unlock(&space_info->lock); + } + return ret; +} + +static struct btrfs_block_rsv *get_block_rsv( + const struct btrfs_trans_handle *trans, + const struct btrfs_root *root) +{ + struct btrfs_block_rsv *block_rsv = NULL; + + if (test_bit(BTRFS_ROOT_REF_COWS, &root->state)) + block_rsv = trans->block_rsv; + + if (root == root->fs_info->csum_root && trans->adding_csums) + block_rsv = trans->block_rsv; + + if (root == root->fs_info->uuid_root) + block_rsv = trans->block_rsv; + + if (!block_rsv) + block_rsv = root->block_rsv; + + if (!block_rsv) + block_rsv = &root->fs_info->empty_block_rsv; + + return block_rsv; +} + +static int block_rsv_use_bytes(struct btrfs_block_rsv *block_rsv, + u64 num_bytes) +{ + int ret = -ENOSPC; + spin_lock(&block_rsv->lock); + if (block_rsv->reserved >= num_bytes) { + block_rsv->reserved -= num_bytes; + if (block_rsv->reserved < block_rsv->size) + block_rsv->full = 0; + ret = 0; + } + spin_unlock(&block_rsv->lock); + return ret; +} + +static void block_rsv_add_bytes(struct btrfs_block_rsv *block_rsv, + u64 num_bytes, int update_size) +{ + spin_lock(&block_rsv->lock); + block_rsv->reserved += num_bytes; + if (update_size) + block_rsv->size += num_bytes; + else if (block_rsv->reserved >= block_rsv->size) + block_rsv->full = 1; + spin_unlock(&block_rsv->lock); +} + +int btrfs_cond_migrate_bytes(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *dest, u64 num_bytes, + int min_factor) +{ + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + u64 min_bytes; + + if (global_rsv->space_info != dest->space_info) + return -ENOSPC; + + spin_lock(&global_rsv->lock); + min_bytes = div_factor(global_rsv->size, min_factor); + if (global_rsv->reserved < min_bytes + num_bytes) { + spin_unlock(&global_rsv->lock); + return -ENOSPC; + } + global_rsv->reserved -= num_bytes; + if (global_rsv->reserved < global_rsv->size) + global_rsv->full = 0; + spin_unlock(&global_rsv->lock); + + block_rsv_add_bytes(dest, num_bytes, 1); + return 0; +} + +static void block_rsv_release_bytes(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, + struct btrfs_block_rsv *dest, u64 num_bytes) +{ + struct btrfs_space_info *space_info = block_rsv->space_info; + + spin_lock(&block_rsv->lock); + if (num_bytes == (u64)-1) + num_bytes = block_rsv->size; + block_rsv->size -= num_bytes; + if (block_rsv->reserved >= block_rsv->size) { + num_bytes = block_rsv->reserved - block_rsv->size; + block_rsv->reserved = block_rsv->size; + block_rsv->full = 1; + } else { + num_bytes = 0; + } + spin_unlock(&block_rsv->lock); + + if (num_bytes > 0) { + if (dest) { + spin_lock(&dest->lock); + if (!dest->full) { + u64 bytes_to_add; + + bytes_to_add = dest->size - dest->reserved; + bytes_to_add = min(num_bytes, bytes_to_add); + dest->reserved += bytes_to_add; + if (dest->reserved >= dest->size) + dest->full = 1; + num_bytes -= bytes_to_add; + } + spin_unlock(&dest->lock); + } + if (num_bytes) { + spin_lock(&space_info->lock); + space_info->bytes_may_use -= num_bytes; + trace_btrfs_space_reservation(fs_info, "space_info", + space_info->flags, num_bytes, 0); + spin_unlock(&space_info->lock); + } + } +} + +static int block_rsv_migrate_bytes(struct btrfs_block_rsv *src, + struct btrfs_block_rsv *dst, u64 num_bytes) +{ + int ret; + + ret = block_rsv_use_bytes(src, num_bytes); + if (ret) + return ret; + + block_rsv_add_bytes(dst, num_bytes, 1); + return 0; +} + +void btrfs_init_block_rsv(struct btrfs_block_rsv *rsv, unsigned short type) +{ + memset(rsv, 0, sizeof(*rsv)); + spin_lock_init(&rsv->lock); + rsv->type = type; +} + +struct btrfs_block_rsv *btrfs_alloc_block_rsv(struct btrfs_root *root, + unsigned short type) +{ + struct btrfs_block_rsv *block_rsv; + struct btrfs_fs_info *fs_info = root->fs_info; + + block_rsv = kmalloc(sizeof(*block_rsv), GFP_NOFS); + if (!block_rsv) + return NULL; + + btrfs_init_block_rsv(block_rsv, type); + block_rsv->space_info = __find_space_info(fs_info, + BTRFS_BLOCK_GROUP_METADATA); + return block_rsv; +} + +void btrfs_free_block_rsv(struct btrfs_root *root, + struct btrfs_block_rsv *rsv) +{ + if (!rsv) + return; + btrfs_block_rsv_release(root, rsv, (u64)-1); + kfree(rsv); +} + +void __btrfs_free_block_rsv(struct btrfs_block_rsv *rsv) +{ + kfree(rsv); +} + +int btrfs_block_rsv_add(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, u64 num_bytes, + enum btrfs_reserve_flush_enum flush) +{ + int ret; + + if (num_bytes == 0) + return 0; + + ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); + if (!ret) { + block_rsv_add_bytes(block_rsv, num_bytes, 1); + return 0; + } + + return ret; +} + +int btrfs_block_rsv_check(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, int min_factor) +{ + u64 num_bytes = 0; + int ret = -ENOSPC; + + if (!block_rsv) + return 0; + + spin_lock(&block_rsv->lock); + num_bytes = div_factor(block_rsv->size, min_factor); + if (block_rsv->reserved >= num_bytes) + ret = 0; + spin_unlock(&block_rsv->lock); + + return ret; +} + +int btrfs_block_rsv_refill(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, u64 min_reserved, + enum btrfs_reserve_flush_enum flush) +{ + u64 num_bytes = 0; + int ret = -ENOSPC; + + if (!block_rsv) + return 0; + + spin_lock(&block_rsv->lock); + num_bytes = min_reserved; + if (block_rsv->reserved >= num_bytes) + ret = 0; + else + num_bytes -= block_rsv->reserved; + spin_unlock(&block_rsv->lock); + + if (!ret) + return 0; + + ret = reserve_metadata_bytes(root, block_rsv, num_bytes, flush); + if (!ret) { + block_rsv_add_bytes(block_rsv, num_bytes, 0); + return 0; + } + + return ret; +} + +int btrfs_block_rsv_migrate(struct btrfs_block_rsv *src_rsv, + struct btrfs_block_rsv *dst_rsv, + u64 num_bytes) +{ + return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes); +} + +void btrfs_block_rsv_release(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, + u64 num_bytes) +{ + struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; + if (global_rsv == block_rsv || + block_rsv->space_info != global_rsv->space_info) + global_rsv = NULL; + block_rsv_release_bytes(root->fs_info, block_rsv, global_rsv, + num_bytes); +} + +/* + * helper to calculate size of global block reservation. + * the desired value is sum of space used by extent tree, + * checksum tree and root tree + */ +static u64 calc_global_metadata_size(struct btrfs_fs_info *fs_info) +{ + struct btrfs_space_info *sinfo; + u64 num_bytes; + u64 meta_used; + u64 data_used; + int csum_size = btrfs_super_csum_size(fs_info->super_copy); + + sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_DATA); + spin_lock(&sinfo->lock); + data_used = sinfo->bytes_used; + spin_unlock(&sinfo->lock); + + sinfo = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + spin_lock(&sinfo->lock); + if (sinfo->flags & BTRFS_BLOCK_GROUP_DATA) + data_used = 0; + meta_used = sinfo->bytes_used; + spin_unlock(&sinfo->lock); + + num_bytes = (data_used >> fs_info->sb->s_blocksize_bits) * + csum_size * 2; + num_bytes += div_u64(data_used + meta_used, 50); + + if (num_bytes * 3 > meta_used) + num_bytes = div_u64(meta_used, 3); + + return ALIGN(num_bytes, fs_info->extent_root->nodesize << 10); +} + +static void update_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + struct btrfs_block_rsv *block_rsv = &fs_info->global_block_rsv; + struct btrfs_space_info *sinfo = block_rsv->space_info; + u64 num_bytes; + + num_bytes = calc_global_metadata_size(fs_info); + + spin_lock(&sinfo->lock); + spin_lock(&block_rsv->lock); + + block_rsv->size = min_t(u64, num_bytes, 512 * 1024 * 1024); + + num_bytes = sinfo->bytes_used + sinfo->bytes_pinned + + sinfo->bytes_reserved + sinfo->bytes_readonly + + sinfo->bytes_may_use; + + if (sinfo->total_bytes > num_bytes) { + num_bytes = sinfo->total_bytes - num_bytes; + block_rsv->reserved += num_bytes; + sinfo->bytes_may_use += num_bytes; + trace_btrfs_space_reservation(fs_info, "space_info", + sinfo->flags, num_bytes, 1); + } + + if (block_rsv->reserved >= block_rsv->size) { + num_bytes = block_rsv->reserved - block_rsv->size; + sinfo->bytes_may_use -= num_bytes; + trace_btrfs_space_reservation(fs_info, "space_info", + sinfo->flags, num_bytes, 0); + block_rsv->reserved = block_rsv->size; + block_rsv->full = 1; + } + + spin_unlock(&block_rsv->lock); + spin_unlock(&sinfo->lock); +} + +static void init_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + struct btrfs_space_info *space_info; + + space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_SYSTEM); + fs_info->chunk_block_rsv.space_info = space_info; + + space_info = __find_space_info(fs_info, BTRFS_BLOCK_GROUP_METADATA); + fs_info->global_block_rsv.space_info = space_info; + fs_info->delalloc_block_rsv.space_info = space_info; + fs_info->trans_block_rsv.space_info = space_info; + fs_info->empty_block_rsv.space_info = space_info; + fs_info->delayed_block_rsv.space_info = space_info; + + fs_info->extent_root->block_rsv = &fs_info->global_block_rsv; + fs_info->csum_root->block_rsv = &fs_info->global_block_rsv; + fs_info->dev_root->block_rsv = &fs_info->global_block_rsv; + fs_info->tree_root->block_rsv = &fs_info->global_block_rsv; + if (fs_info->quota_root) + fs_info->quota_root->block_rsv = &fs_info->global_block_rsv; + fs_info->chunk_root->block_rsv = &fs_info->chunk_block_rsv; + + update_global_block_rsv(fs_info); +} + +static void release_global_block_rsv(struct btrfs_fs_info *fs_info) +{ + block_rsv_release_bytes(fs_info, &fs_info->global_block_rsv, NULL, + (u64)-1); + WARN_ON(fs_info->delalloc_block_rsv.size > 0); + WARN_ON(fs_info->delalloc_block_rsv.reserved > 0); + WARN_ON(fs_info->trans_block_rsv.size > 0); + WARN_ON(fs_info->trans_block_rsv.reserved > 0); + WARN_ON(fs_info->chunk_block_rsv.size > 0); + WARN_ON(fs_info->chunk_block_rsv.reserved > 0); + WARN_ON(fs_info->delayed_block_rsv.size > 0); + WARN_ON(fs_info->delayed_block_rsv.reserved > 0); +} + +void btrfs_trans_release_metadata(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + if (!trans->block_rsv) + return; + + if (!trans->bytes_reserved) + return; + + trace_btrfs_space_reservation(root->fs_info, "transaction", + trans->transid, trans->bytes_reserved, 0); + btrfs_block_rsv_release(root, trans->block_rsv, trans->bytes_reserved); + trans->bytes_reserved = 0; +} + +/* Can only return 0 or -ENOSPC */ +int btrfs_orphan_reserve_metadata(struct btrfs_trans_handle *trans, + struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *src_rsv = get_block_rsv(trans, root); + struct btrfs_block_rsv *dst_rsv = root->orphan_block_rsv; + + /* + * We need to hold space in order to delete our orphan item once we've + * added it, so this takes the reservation so we can release it later + * when we are truly done with the orphan item. + */ + u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1); + trace_btrfs_space_reservation(root->fs_info, "orphan", + btrfs_ino(inode), num_bytes, 1); + return block_rsv_migrate_bytes(src_rsv, dst_rsv, num_bytes); +} + +void btrfs_orphan_release_metadata(struct inode *inode) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 num_bytes = btrfs_calc_trans_metadata_size(root, 1); + trace_btrfs_space_reservation(root->fs_info, "orphan", + btrfs_ino(inode), num_bytes, 0); + btrfs_block_rsv_release(root, root->orphan_block_rsv, num_bytes); +} + +/* + * btrfs_subvolume_reserve_metadata() - reserve space for subvolume operation + * root: the root of the parent directory + * rsv: block reservation + * items: the number of items that we need do reservation + * qgroup_reserved: used to return the reserved size in qgroup + * + * This function is used to reserve the space for snapshot/subvolume + * creation and deletion. Those operations are different with the + * common file/directory operations, they change two fs/file trees + * and root tree, the number of items that the qgroup reserves is + * different with the free space reservation. So we can not use + * the space reseravtion mechanism in start_transaction(). + */ +int btrfs_subvolume_reserve_metadata(struct btrfs_root *root, + struct btrfs_block_rsv *rsv, + int items, + u64 *qgroup_reserved, + bool use_global_rsv) +{ + u64 num_bytes; + int ret; + struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; + + if (root->fs_info->quota_enabled) { + /* One for parent inode, two for dir entries */ + num_bytes = 3 * root->nodesize; + ret = btrfs_qgroup_reserve(root, num_bytes); + if (ret) + return ret; + } else { + num_bytes = 0; + } + + *qgroup_reserved = num_bytes; + + num_bytes = btrfs_calc_trans_metadata_size(root, items); + rsv->space_info = __find_space_info(root->fs_info, + BTRFS_BLOCK_GROUP_METADATA); + ret = btrfs_block_rsv_add(root, rsv, num_bytes, + BTRFS_RESERVE_FLUSH_ALL); + + if (ret == -ENOSPC && use_global_rsv) + ret = btrfs_block_rsv_migrate(global_rsv, rsv, num_bytes); + + if (ret) { + if (*qgroup_reserved) + btrfs_qgroup_free(root, *qgroup_reserved); + } + + return ret; +} + +void btrfs_subvolume_release_metadata(struct btrfs_root *root, + struct btrfs_block_rsv *rsv, + u64 qgroup_reserved) +{ + btrfs_block_rsv_release(root, rsv, (u64)-1); +} + +/** + * drop_outstanding_extent - drop an outstanding extent + * @inode: the inode we're dropping the extent for + * @num_bytes: the number of bytes we're relaseing. + * + * This is called when we are freeing up an outstanding extent, either called + * after an error or after an extent is written. This will return the number of + * reserved extents that need to be freed. This must be called with + * BTRFS_I(inode)->lock held. + */ +static unsigned drop_outstanding_extent(struct inode *inode, u64 num_bytes) +{ + unsigned drop_inode_space = 0; + unsigned dropped_extents = 0; + unsigned num_extents = 0; + + num_extents = (unsigned)div64_u64(num_bytes + + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + ASSERT(num_extents); + ASSERT(BTRFS_I(inode)->outstanding_extents >= num_extents); + BTRFS_I(inode)->outstanding_extents -= num_extents; + + if (BTRFS_I(inode)->outstanding_extents == 0 && + test_and_clear_bit(BTRFS_INODE_DELALLOC_META_RESERVED, + &BTRFS_I(inode)->runtime_flags)) + drop_inode_space = 1; + + /* + * If we have more or the same amount of outsanding extents than we have + * reserved then we need to leave the reserved extents count alone. + */ + if (BTRFS_I(inode)->outstanding_extents >= + BTRFS_I(inode)->reserved_extents) + return drop_inode_space; + + dropped_extents = BTRFS_I(inode)->reserved_extents - + BTRFS_I(inode)->outstanding_extents; + BTRFS_I(inode)->reserved_extents -= dropped_extents; + return dropped_extents + drop_inode_space; +} + +/** + * calc_csum_metadata_size - return the amount of metada space that must be + * reserved/free'd for the given bytes. + * @inode: the inode we're manipulating + * @num_bytes: the number of bytes in question + * @reserve: 1 if we are reserving space, 0 if we are freeing space + * + * This adjusts the number of csum_bytes in the inode and then returns the + * correct amount of metadata that must either be reserved or freed. We + * calculate how many checksums we can fit into one leaf and then divide the + * number of bytes that will need to be checksumed by this value to figure out + * how many checksums will be required. If we are adding bytes then the number + * may go up and we will return the number of additional bytes that must be + * reserved. If it is going down we will return the number of bytes that must + * be freed. + * + * This must be called with BTRFS_I(inode)->lock held. + */ +static u64 calc_csum_metadata_size(struct inode *inode, u64 num_bytes, + int reserve) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 old_csums, num_csums; + + if (BTRFS_I(inode)->flags & BTRFS_INODE_NODATASUM && + BTRFS_I(inode)->csum_bytes == 0) + return 0; + + old_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes); + if (reserve) + BTRFS_I(inode)->csum_bytes += num_bytes; + else + BTRFS_I(inode)->csum_bytes -= num_bytes; + num_csums = btrfs_csum_bytes_to_leaves(root, BTRFS_I(inode)->csum_bytes); + + /* No change, no need to reserve more */ + if (old_csums == num_csums) + return 0; + + if (reserve) + return btrfs_calc_trans_metadata_size(root, + num_csums - old_csums); + + return btrfs_calc_trans_metadata_size(root, old_csums - num_csums); +} + +int btrfs_delalloc_reserve_metadata(struct inode *inode, u64 num_bytes) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + struct btrfs_block_rsv *block_rsv = &root->fs_info->delalloc_block_rsv; + u64 to_reserve = 0; + u64 csum_bytes; + unsigned nr_extents = 0; + int extra_reserve = 0; + enum btrfs_reserve_flush_enum flush = BTRFS_RESERVE_FLUSH_ALL; + int ret = 0; + bool delalloc_lock = true; + u64 to_free = 0; + unsigned dropped; + + /* If we are a free space inode we need to not flush since we will be in + * the middle of a transaction commit. We also don't need the delalloc + * mutex since we won't race with anybody. We need this mostly to make + * lockdep shut its filthy mouth. + */ + if (btrfs_is_free_space_inode(inode)) { + flush = BTRFS_RESERVE_NO_FLUSH; + delalloc_lock = false; + } + + if (flush != BTRFS_RESERVE_NO_FLUSH && + btrfs_transaction_in_commit(root->fs_info)) + schedule_timeout(1); + + if (delalloc_lock) + mutex_lock(&BTRFS_I(inode)->delalloc_mutex); + + num_bytes = ALIGN(num_bytes, root->sectorsize); + + spin_lock(&BTRFS_I(inode)->lock); + nr_extents = (unsigned)div64_u64(num_bytes + + BTRFS_MAX_EXTENT_SIZE - 1, + BTRFS_MAX_EXTENT_SIZE); + BTRFS_I(inode)->outstanding_extents += nr_extents; + nr_extents = 0; + + if (BTRFS_I(inode)->outstanding_extents > + BTRFS_I(inode)->reserved_extents) + nr_extents = BTRFS_I(inode)->outstanding_extents - + BTRFS_I(inode)->reserved_extents; + + /* + * Add an item to reserve for updating the inode when we complete the + * delalloc io. + */ + if (!test_bit(BTRFS_INODE_DELALLOC_META_RESERVED, + &BTRFS_I(inode)->runtime_flags)) { + nr_extents++; + extra_reserve = 1; + } + + to_reserve = btrfs_calc_trans_metadata_size(root, nr_extents); + to_reserve += calc_csum_metadata_size(inode, num_bytes, 1); + csum_bytes = BTRFS_I(inode)->csum_bytes; + spin_unlock(&BTRFS_I(inode)->lock); + + if (root->fs_info->quota_enabled) { + ret = btrfs_qgroup_reserve(root, nr_extents * root->nodesize); + if (ret) + goto out_fail; + } + + ret = reserve_metadata_bytes(root, block_rsv, to_reserve, flush); + if (unlikely(ret)) { + if (root->fs_info->quota_enabled) + btrfs_qgroup_free(root, nr_extents * root->nodesize); + goto out_fail; + } + + spin_lock(&BTRFS_I(inode)->lock); + if (extra_reserve) { + set_bit(BTRFS_INODE_DELALLOC_META_RESERVED, + &BTRFS_I(inode)->runtime_flags); + nr_extents--; + } + BTRFS_I(inode)->reserved_extents += nr_extents; + spin_unlock(&BTRFS_I(inode)->lock); + + if (delalloc_lock) + mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); + + if (to_reserve) + trace_btrfs_space_reservation(root->fs_info, "delalloc", + btrfs_ino(inode), to_reserve, 1); + block_rsv_add_bytes(block_rsv, to_reserve, 1); + + return 0; + +out_fail: + spin_lock(&BTRFS_I(inode)->lock); + dropped = drop_outstanding_extent(inode, num_bytes); + /* + * If the inodes csum_bytes is the same as the original + * csum_bytes then we know we haven't raced with any free()ers + * so we can just reduce our inodes csum bytes and carry on. + */ + if (BTRFS_I(inode)->csum_bytes == csum_bytes) { + calc_csum_metadata_size(inode, num_bytes, 0); + } else { + u64 orig_csum_bytes = BTRFS_I(inode)->csum_bytes; + u64 bytes; + + /* + * This is tricky, but first we need to figure out how much we + * free'd from any free-ers that occured during this + * reservation, so we reset ->csum_bytes to the csum_bytes + * before we dropped our lock, and then call the free for the + * number of bytes that were freed while we were trying our + * reservation. + */ + bytes = csum_bytes - BTRFS_I(inode)->csum_bytes; + BTRFS_I(inode)->csum_bytes = csum_bytes; + to_free = calc_csum_metadata_size(inode, bytes, 0); + + + /* + * Now we need to see how much we would have freed had we not + * been making this reservation and our ->csum_bytes were not + * artificially inflated. + */ + BTRFS_I(inode)->csum_bytes = csum_bytes - num_bytes; + bytes = csum_bytes - orig_csum_bytes; + bytes = calc_csum_metadata_size(inode, bytes, 0); + + /* + * Now reset ->csum_bytes to what it should be. If bytes is + * more than to_free then we would have free'd more space had we + * not had an artificially high ->csum_bytes, so we need to free + * the remainder. If bytes is the same or less then we don't + * need to do anything, the other free-ers did the correct + * thing. + */ + BTRFS_I(inode)->csum_bytes = orig_csum_bytes - num_bytes; + if (bytes > to_free) + to_free = bytes - to_free; + else + to_free = 0; + } + spin_unlock(&BTRFS_I(inode)->lock); + if (dropped) + to_free += btrfs_calc_trans_metadata_size(root, dropped); + + if (to_free) { + btrfs_block_rsv_release(root, block_rsv, to_free); + trace_btrfs_space_reservation(root->fs_info, "delalloc", + btrfs_ino(inode), to_free, 0); + } + if (delalloc_lock) + mutex_unlock(&BTRFS_I(inode)->delalloc_mutex); + return ret; +} + +/** + * btrfs_delalloc_release_metadata - release a metadata reservation for an inode + * @inode: the inode to release the reservation for + * @num_bytes: the number of bytes we're releasing + * + * This will release the metadata reservation for an inode. This can be called + * once we complete IO for a given set of bytes to release their metadata + * reservations. + */ +void btrfs_delalloc_release_metadata(struct inode *inode, u64 num_bytes) +{ + struct btrfs_root *root = BTRFS_I(inode)->root; + u64 to_free = 0; + unsigned dropped; + + num_bytes = ALIGN(num_bytes, root->sectorsize); + spin_lock(&BTRFS_I(inode)->lock); + dropped = drop_outstanding_extent(inode, num_bytes); + + if (num_bytes) + to_free = calc_csum_metadata_size(inode, num_bytes, 0); + spin_unlock(&BTRFS_I(inode)->lock); + if (dropped > 0) + to_free += btrfs_calc_trans_metadata_size(root, dropped); + + if (btrfs_test_is_dummy_root(root)) + return; + + trace_btrfs_space_reservation(root->fs_info, "delalloc", + btrfs_ino(inode), to_free, 0); + + btrfs_block_rsv_release(root, &root->fs_info->delalloc_block_rsv, + to_free); +} + +/** + * btrfs_delalloc_reserve_space - reserve data and metadata space for delalloc + * @inode: inode we're writing to + * @num_bytes: the number of bytes we want to allocate + * + * This will do the following things + * + * o reserve space in the data space info for num_bytes + * o reserve space in the metadata space info based on number of outstanding + * extents and how much csums will be needed + * o add to the inodes ->delalloc_bytes + * o add it to the fs_info's delalloc inodes list. + * + * This will return 0 for success and -ENOSPC if there is no space left. + */ +int btrfs_delalloc_reserve_space(struct inode *inode, u64 num_bytes) +{ + int ret; + + ret = btrfs_check_data_free_space(inode, num_bytes, num_bytes); + if (ret) + return ret; + + ret = btrfs_delalloc_reserve_metadata(inode, num_bytes); + if (ret) { + btrfs_free_reserved_data_space(inode, num_bytes); + return ret; + } + + return 0; +} + +/** + * btrfs_delalloc_release_space - release data and metadata space for delalloc + * @inode: inode we're releasing space for + * @num_bytes: the number of bytes we want to free up + * + * This must be matched with a call to btrfs_delalloc_reserve_space. This is + * called in the case that we don't need the metadata AND data reservations + * anymore. So if there is an error or we insert an inline extent. + * + * This function will release the metadata space that was not used and will + * decrement ->delalloc_bytes and remove it from the fs_info delalloc_inodes + * list if there are no delalloc bytes left. + */ +void btrfs_delalloc_release_space(struct inode *inode, u64 num_bytes) +{ + btrfs_delalloc_release_metadata(inode, num_bytes); + btrfs_free_reserved_data_space(inode, num_bytes); +} + +static int update_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr, + u64 num_bytes, int alloc) +{ + struct btrfs_block_group_cache *cache = NULL; + struct btrfs_fs_info *info = root->fs_info; + u64 total = num_bytes; + u64 old_val; + u64 byte_in_group; + int factor; + + /* block accounting for super block */ + spin_lock(&info->delalloc_root_lock); + old_val = btrfs_super_bytes_used(info->super_copy); + if (alloc) + old_val += num_bytes; + else + old_val -= num_bytes; + btrfs_set_super_bytes_used(info->super_copy, old_val); + spin_unlock(&info->delalloc_root_lock); + + while (total) { + cache = btrfs_lookup_block_group(info, bytenr); + if (!cache) + return -ENOENT; + if (cache->flags & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + factor = 2; + else + factor = 1; + /* + * If this block group has free space cache written out, we + * need to make sure to load it if we are removing space. This + * is because we need the unpinning stage to actually add the + * space back to the block group, otherwise we will leak space. + */ + if (!alloc && cache->cached == BTRFS_CACHE_NO) + cache_block_group(cache, 1); + + byte_in_group = bytenr - cache->key.objectid; + WARN_ON(byte_in_group > cache->key.offset); + + spin_lock(&cache->space_info->lock); + spin_lock(&cache->lock); + + if (btrfs_test_opt(root, SPACE_CACHE) && + cache->disk_cache_state < BTRFS_DC_CLEAR) + cache->disk_cache_state = BTRFS_DC_CLEAR; + + old_val = btrfs_block_group_used(&cache->item); + num_bytes = min(total, cache->key.offset - byte_in_group); + if (alloc) { + old_val += num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + cache->reserved -= num_bytes; + cache->space_info->bytes_reserved -= num_bytes; + cache->space_info->bytes_used += num_bytes; + cache->space_info->disk_used += num_bytes * factor; + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + } else { + old_val -= num_bytes; + btrfs_set_block_group_used(&cache->item, old_val); + cache->pinned += num_bytes; + cache->space_info->bytes_pinned += num_bytes; + cache->space_info->bytes_used -= num_bytes; + cache->space_info->disk_used -= num_bytes * factor; + spin_unlock(&cache->lock); + spin_unlock(&cache->space_info->lock); + + set_extent_dirty(info->pinned_extents, + bytenr, bytenr + num_bytes - 1, + GFP_NOFS | __GFP_NOFAIL); + /* + * No longer have used bytes in this block group, queue + * it for deletion. + */ + if (old_val == 0) { + spin_lock(&info->unused_bgs_lock); + if (list_empty(&cache->bg_list)) { + btrfs_get_block_group(cache); + list_add_tail(&cache->bg_list, + &info->unused_bgs); + } + spin_unlock(&info->unused_bgs_lock); + } + } + + spin_lock(&trans->transaction->dirty_bgs_lock); + if (list_empty(&cache->dirty_list)) { + list_add_tail(&cache->dirty_list, + &trans->transaction->dirty_bgs); + trans->transaction->num_dirty_bgs++; + btrfs_get_block_group(cache); + } + spin_unlock(&trans->transaction->dirty_bgs_lock); + + 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; + + spin_lock(&root->fs_info->block_group_cache_lock); + bytenr = root->fs_info->first_logical_byte; + spin_unlock(&root->fs_info->block_group_cache_lock); + + if (bytenr < (u64)-1) + return 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; +} + +static int pin_down_extent(struct btrfs_root *root, + struct btrfs_block_group_cache *cache, + u64 bytenr, u64 num_bytes, int reserved) +{ + 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); + + set_extent_dirty(root->fs_info->pinned_extents, bytenr, + bytenr + num_bytes - 1, GFP_NOFS | __GFP_NOFAIL); + if (reserved) + trace_btrfs_reserved_extent_free(root, bytenr, num_bytes); + return 0; +} + +/* + * this function must be called within transaction + */ +int btrfs_pin_extent(struct btrfs_root *root, + u64 bytenr, u64 num_bytes, int reserved) +{ + struct btrfs_block_group_cache *cache; + + cache = btrfs_lookup_block_group(root->fs_info, bytenr); + BUG_ON(!cache); /* Logic error */ + + pin_down_extent(root, cache, bytenr, num_bytes, reserved); + + btrfs_put_block_group(cache); + return 0; +} + +/* + * this function must be called within transaction + */ +int btrfs_pin_extent_for_log_replay(struct btrfs_root *root, + u64 bytenr, u64 num_bytes) +{ + struct btrfs_block_group_cache *cache; + int ret; + + cache = btrfs_lookup_block_group(root->fs_info, bytenr); + if (!cache) + return -EINVAL; + + /* + * pull in the free space cache (if any) so that our pin + * removes the free space from the cache. We have load_only set + * to one because the slow code to read in the free extents does check + * the pinned extents. + */ + cache_block_group(cache, 1); + + pin_down_extent(root, cache, bytenr, num_bytes, 0); + + /* remove us from the free space cache (if we're there at all) */ + ret = btrfs_remove_free_space(cache, bytenr, num_bytes); + btrfs_put_block_group(cache); + return ret; +} + +static int __exclude_logged_extent(struct btrfs_root *root, u64 start, u64 num_bytes) +{ + int ret; + struct btrfs_block_group_cache *block_group; + struct btrfs_caching_control *caching_ctl; + + block_group = btrfs_lookup_block_group(root->fs_info, start); + if (!block_group) + return -EINVAL; + + cache_block_group(block_group, 0); + caching_ctl = get_caching_control(block_group); + + if (!caching_ctl) { + /* Logic error */ + BUG_ON(!block_group_cache_done(block_group)); + ret = btrfs_remove_free_space(block_group, start, num_bytes); + } else { + mutex_lock(&caching_ctl->mutex); + + if (start >= caching_ctl->progress) { + ret = add_excluded_extent(root, start, num_bytes); + } else if (start + num_bytes <= caching_ctl->progress) { + ret = btrfs_remove_free_space(block_group, + start, num_bytes); + } else { + num_bytes = caching_ctl->progress - start; + ret = btrfs_remove_free_space(block_group, + start, num_bytes); + if (ret) + goto out_lock; + + num_bytes = (start + num_bytes) - + caching_ctl->progress; + start = caching_ctl->progress; + ret = add_excluded_extent(root, start, num_bytes); + } +out_lock: + mutex_unlock(&caching_ctl->mutex); + put_caching_control(caching_ctl); + } + btrfs_put_block_group(block_group); + return ret; +} + +int btrfs_exclude_logged_extents(struct btrfs_root *log, + struct extent_buffer *eb) +{ + struct btrfs_file_extent_item *item; + struct btrfs_key key; + int found_type; + int i; + + if (!btrfs_fs_incompat(log->fs_info, MIXED_GROUPS)) + return 0; + + for (i = 0; i < btrfs_header_nritems(eb); i++) { + btrfs_item_key_to_cpu(eb, &key, i); + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + item = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); + found_type = btrfs_file_extent_type(eb, item); + if (found_type == BTRFS_FILE_EXTENT_INLINE) + continue; + if (btrfs_file_extent_disk_bytenr(eb, item) == 0) + continue; + key.objectid = btrfs_file_extent_disk_bytenr(eb, item); + key.offset = btrfs_file_extent_disk_num_bytes(eb, item); + __exclude_logged_extent(log, key.objectid, key.offset); + } + + return 0; +} + +/** + * btrfs_update_reserved_bytes - update the block_group and space info counters + * @cache: The cache we are manipulating + * @num_bytes: The number of bytes in question + * @reserve: One of the reservation enums + * @delalloc: The blocks are allocated for the delalloc write + * + * This is called by the allocator when it reserves space, or by somebody who is + * freeing space that was never actually used on disk. For example if you + * reserve some space for a new leaf in transaction A and before transaction A + * commits you free that leaf, you call this with reserve set to 0 in order to + * clear the reservation. + * + * Metadata reservations should be called with RESERVE_ALLOC so we do the proper + * ENOSPC accounting. For data we handle the reservation through clearing the + * delalloc bits in the io_tree. We have to do this since we could end up + * allocating less disk space for the amount of data we have reserved in the + * case of compression. + * + * If this is a reservation and the block group has become read only we cannot + * make the reservation and return -EAGAIN, otherwise this function always + * succeeds. + */ +static int btrfs_update_reserved_bytes(struct btrfs_block_group_cache *cache, + u64 num_bytes, int reserve, int delalloc) +{ + struct btrfs_space_info *space_info = cache->space_info; + int ret = 0; + + spin_lock(&space_info->lock); + spin_lock(&cache->lock); + if (reserve != RESERVE_FREE) { + if (cache->ro) { + ret = -EAGAIN; + } else { + cache->reserved += num_bytes; + space_info->bytes_reserved += num_bytes; + if (reserve == RESERVE_ALLOC) { + trace_btrfs_space_reservation(cache->fs_info, + "space_info", space_info->flags, + num_bytes, 0); + space_info->bytes_may_use -= num_bytes; + } + + if (delalloc) + cache->delalloc_bytes += num_bytes; + } + } else { + if (cache->ro) + space_info->bytes_readonly += num_bytes; + cache->reserved -= num_bytes; + space_info->bytes_reserved -= num_bytes; + + if (delalloc) + cache->delalloc_bytes -= num_bytes; + } + spin_unlock(&cache->lock); + spin_unlock(&space_info->lock); + return ret; +} + +void 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->commit_root_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->commit_root_sem); + + update_global_block_rsv(fs_info); +} + +static int unpin_extent_range(struct btrfs_root *root, u64 start, u64 end, + const bool return_free_space) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_group_cache *cache = NULL; + struct btrfs_space_info *space_info; + struct btrfs_block_rsv *global_rsv = &fs_info->global_block_rsv; + u64 len; + bool readonly; + + while (start <= end) { + readonly = false; + 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); /* Logic error */ + } + + len = cache->key.objectid + cache->key.offset - start; + len = min(len, end + 1 - start); + + if (start < cache->last_byte_to_unpin) { + len = min(len, cache->last_byte_to_unpin - start); + if (return_free_space) + btrfs_add_free_space(cache, start, len); + } + + start += len; + space_info = cache->space_info; + + spin_lock(&space_info->lock); + spin_lock(&cache->lock); + cache->pinned -= len; + space_info->bytes_pinned -= len; + percpu_counter_add(&space_info->total_bytes_pinned, -len); + if (cache->ro) { + space_info->bytes_readonly += len; + readonly = true; + } + spin_unlock(&cache->lock); + if (!readonly && global_rsv->space_info == space_info) { + spin_lock(&global_rsv->lock); + if (!global_rsv->full) { + len = min(len, global_rsv->size - + global_rsv->reserved); + global_rsv->reserved += len; + space_info->bytes_may_use += len; + if (global_rsv->reserved >= global_rsv->size) + global_rsv->full = 1; + } + spin_unlock(&global_rsv->lock); + } + spin_unlock(&space_info->lock); + } + + if (cache) + btrfs_put_block_group(cache); + return 0; +} + +int btrfs_finish_extent_commit(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct extent_io_tree *unpin; + u64 start; + u64 end; + int ret; + + if (trans->aborted) + return 0; + + 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) { + mutex_lock(&fs_info->unused_bg_unpin_mutex); + ret = find_first_extent_bit(unpin, 0, &start, &end, + EXTENT_DIRTY, NULL); + if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); + break; + } + + if (btrfs_test_opt(root, DISCARD)) + ret = btrfs_discard_extent(root, start, + end + 1 - start, NULL); + + clear_extent_dirty(unpin, start, end, GFP_NOFS); + unpin_extent_range(root, start, end, true); + mutex_unlock(&fs_info->unused_bg_unpin_mutex); + cond_resched(); + } + + return 0; +} + +static void add_pinned_bytes(struct btrfs_fs_info *fs_info, u64 num_bytes, + u64 owner, u64 root_objectid) +{ + struct btrfs_space_info *space_info; + u64 flags; + + if (owner < BTRFS_FIRST_FREE_OBJECTID) { + if (root_objectid == BTRFS_CHUNK_TREE_OBJECTID) + flags = BTRFS_BLOCK_GROUP_SYSTEM; + else + flags = BTRFS_BLOCK_GROUP_METADATA; + } else { + flags = BTRFS_BLOCK_GROUP_DATA; + } + + space_info = __find_space_info(fs_info, flags); + BUG_ON(!space_info); /* Logic bug */ + percpu_counter_add(&space_info->total_bytes_pinned, num_bytes); +} + + +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, + int no_quota) +{ + 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; + int last_ref = 0; + enum btrfs_qgroup_operation_type type = BTRFS_QGROUP_OPER_SUB_EXCL; + bool skinny_metadata = btrfs_fs_incompat(root->fs_info, + SKINNY_METADATA); + + if (!info->quota_enabled || !is_fstree(root_objectid)) + no_quota = 1; + + 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); + + if (is_data) + skinny_metadata = 0; + + 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 (key.type == BTRFS_METADATA_ITEM_KEY && + key.offset == owner_objectid) { + 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, &last_ref); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + btrfs_release_path(path); + path->leave_spinning = 1; + + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = num_bytes; + + if (!is_data && skinny_metadata) { + key.type = BTRFS_METADATA_ITEM_KEY; + key.offset = owner_objectid; + } + + ret = btrfs_search_slot(trans, extent_root, + &key, path, -1, 1); + if (ret > 0 && skinny_metadata && path->slots[0]) { + /* + * Couldn't find our skinny metadata item, + * see if we have ye olde extent item. + */ + path->slots[0]--; + btrfs_item_key_to_cpu(path->nodes[0], &key, + path->slots[0]); + if (key.objectid == bytenr && + key.type == BTRFS_EXTENT_ITEM_KEY && + key.offset == num_bytes) + ret = 0; + } + + if (ret > 0 && skinny_metadata) { + skinny_metadata = false; + key.objectid = bytenr; + key.type = BTRFS_EXTENT_ITEM_KEY; + key.offset = num_bytes; + btrfs_release_path(path); + ret = btrfs_search_slot(trans, extent_root, + &key, path, -1, 1); + } + + if (ret) { + btrfs_err(info, "umm, got %d back from search, was looking for %llu", + ret, bytenr); + if (ret > 0) + btrfs_print_leaf(extent_root, + path->nodes[0]); + } + if (ret < 0) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + extent_slot = path->slots[0]; + } + } else if (WARN_ON(ret == -ENOENT)) { + btrfs_print_leaf(extent_root, path->nodes[0]); + btrfs_err(info, + "unable to find ref byte nr %llu parent %llu root %llu owner %llu offset %llu", + bytenr, parent, root_objectid, owner_objectid, + owner_offset); + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } else { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + + 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); + if (ret < 0) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + + btrfs_release_path(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) { + btrfs_err(info, "umm, got %d back from search, was looking for %llu", + ret, bytenr); + btrfs_print_leaf(extent_root, path->nodes[0]); + } + if (ret < 0) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + + 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 && + key.type == BTRFS_EXTENT_ITEM_KEY) { + struct btrfs_tree_block_info *bi; + BUG_ON(item_size < sizeof(*ei) + sizeof(*bi)); + bi = (struct btrfs_tree_block_info *)(ei + 1); + WARN_ON(owner_objectid != btrfs_tree_block_level(leaf, bi)); + } + + refs = btrfs_extent_refs(leaf, ei); + if (refs < refs_to_drop) { + btrfs_err(info, "trying to drop %d refs but we only have %Lu " + "for bytenr %Lu", refs_to_drop, refs, bytenr); + ret = -EINVAL; + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + refs -= refs_to_drop; + + if (refs > 0) { + type = BTRFS_QGROUP_OPER_SUB_SHARED; + 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, &last_ref); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + } + add_pinned_bytes(root->fs_info, -num_bytes, owner_objectid, + root_objectid); + } else { + 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; + } + } + + last_ref = 1; + ret = btrfs_del_items(trans, extent_root, path, path->slots[0], + num_to_del); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + btrfs_release_path(path); + + if (is_data) { + ret = btrfs_del_csums(trans, root, bytenr, num_bytes); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + } + + ret = update_block_group(trans, root, bytenr, num_bytes, 0); + if (ret) { + btrfs_abort_transaction(trans, extent_root, ret); + goto out; + } + } + btrfs_release_path(path); + + /* Deal with the quota accounting */ + if (!ret && last_ref && !no_quota) { + int mod_seq = 0; + + if (owner_objectid >= BTRFS_FIRST_FREE_OBJECTID && + type == BTRFS_QGROUP_OPER_SUB_SHARED) + mod_seq = 1; + + ret = btrfs_qgroup_record_ref(trans, info, root_objectid, + bytenr, num_bytes, type, + mod_seq); + } +out: + btrfs_free_path(path); + return ret; +} + +/* + * when we free an block, it is possible (and likely) that we free the last + * delayed ref for that extent as well. This searches the delayed ref tree for + * a given extent, and if there are no other delayed refs to be processed, it + * removes it from the tree. + */ +static noinline int check_ref_cleanup(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 bytenr) +{ + struct btrfs_delayed_ref_head *head; + struct btrfs_delayed_ref_root *delayed_refs; + int ret = 0; + + delayed_refs = &trans->transaction->delayed_refs; + spin_lock(&delayed_refs->lock); + head = btrfs_find_delayed_ref_head(trans, bytenr); + if (!head) + goto out_delayed_unlock; + + spin_lock(&head->lock); + if (rb_first(&head->ref_root)) + goto out; + + if (head->extent_op) { + if (!head->must_insert_reserved) + goto out; + btrfs_free_delayed_extent_op(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->href_node, &delayed_refs->href_root); + + atomic_dec(&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 (head->processing == 0) + delayed_refs->num_heads_ready--; + head->processing = 0; + spin_unlock(&head->lock); + spin_unlock(&delayed_refs->lock); + + BUG_ON(head->extent_op); + if (head->must_insert_reserved) + ret = 1; + + mutex_unlock(&head->mutex); + btrfs_put_delayed_ref(&head->node); + return ret; +out: + spin_unlock(&head->lock); + +out_delayed_unlock: + spin_unlock(&delayed_refs->lock); + return 0; +} + +void btrfs_free_tree_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *buf, + u64 parent, int last_ref) +{ + int pin = 1; + int ret; + + if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { + ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, + buf->start, buf->len, + parent, root->root_key.objectid, + btrfs_header_level(buf), + BTRFS_DROP_DELAYED_REF, NULL, 0); + BUG_ON(ret); /* -ENOMEM */ + } + + if (!last_ref) + return; + + if (btrfs_header_generation(buf) == trans->transid) { + struct btrfs_block_group_cache *cache; + + if (root->root_key.objectid != BTRFS_TREE_LOG_OBJECTID) { + ret = check_ref_cleanup(trans, root, buf->start); + if (!ret) + goto out; + } + + cache = btrfs_lookup_block_group(root->fs_info, buf->start); + + if (btrfs_header_flag(buf, BTRFS_HEADER_FLAG_WRITTEN)) { + pin_down_extent(root, cache, buf->start, buf->len, 1); + btrfs_put_block_group(cache); + goto out; + } + + WARN_ON(test_bit(EXTENT_BUFFER_DIRTY, &buf->bflags)); + + btrfs_add_free_space(cache, buf->start, buf->len); + btrfs_update_reserved_bytes(cache, buf->len, RESERVE_FREE, 0); + btrfs_put_block_group(cache); + trace_btrfs_reserved_extent_free(root, buf->start, buf->len); + pin = 0; + } +out: + if (pin) + add_pinned_bytes(root->fs_info, buf->len, + btrfs_header_level(buf), + root->root_key.objectid); + + /* + * Deleting the buffer, clear the corrupt flag since it doesn't matter + * anymore. + */ + clear_bit(EXTENT_BUFFER_CORRUPT, &buf->bflags); +} + +/* Can return -ENOMEM */ +int btrfs_free_extent(struct btrfs_trans_handle *trans, struct btrfs_root *root, + u64 bytenr, u64 num_bytes, u64 parent, u64 root_objectid, + u64 owner, u64 offset, int no_quota) +{ + int ret; + struct btrfs_fs_info *fs_info = root->fs_info; + + if (btrfs_test_is_dummy_root(root)) + return 0; + + add_pinned_bytes(root->fs_info, num_bytes, owner, root_objectid); + + /* + * 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(fs_info, trans, bytenr, + num_bytes, + parent, root_objectid, (int)owner, + BTRFS_DROP_DELAYED_REF, NULL, no_quota); + } else { + ret = btrfs_add_delayed_data_ref(fs_info, trans, bytenr, + num_bytes, + parent, root_objectid, owner, + offset, BTRFS_DROP_DELAYED_REF, + NULL, no_quota); + } + return ret; +} + +/* + * when we wait for progress in the block group caching, its because + * our allocation attempt failed at least once. So, we must sleep + * and let some progress happen before we try again. + * + * This function will sleep at least once waiting for new free space to + * show up, and then it will check the block group free space numbers + * for our min num_bytes. Another option is to have it go ahead + * and look in the rbtree for a free extent of a given size, but this + * is a good start. + * + * Callers of this must check if cache->cached == BTRFS_CACHE_ERROR before using + * any of the information in this block group. + */ +static noinline void +wait_block_group_cache_progress(struct btrfs_block_group_cache *cache, + u64 num_bytes) +{ + struct btrfs_caching_control *caching_ctl; + + caching_ctl = get_caching_control(cache); + if (!caching_ctl) + return; + + wait_event(caching_ctl->wait, block_group_cache_done(cache) || + (cache->free_space_ctl->free_space >= num_bytes)); + + put_caching_control(caching_ctl); +} + +static noinline int +wait_block_group_cache_done(struct btrfs_block_group_cache *cache) +{ + struct btrfs_caching_control *caching_ctl; + int ret = 0; + + caching_ctl = get_caching_control(cache); + if (!caching_ctl) + return (cache->cached == BTRFS_CACHE_ERROR) ? -EIO : 0; + + wait_event(caching_ctl->wait, block_group_cache_done(cache)); + if (cache->cached == BTRFS_CACHE_ERROR) + ret = -EIO; + put_caching_control(caching_ctl); + return ret; +} + +int __get_raid_index(u64 flags) +{ + if (flags & BTRFS_BLOCK_GROUP_RAID10) + return BTRFS_RAID_RAID10; + else if (flags & BTRFS_BLOCK_GROUP_RAID1) + return BTRFS_RAID_RAID1; + else if (flags & BTRFS_BLOCK_GROUP_DUP) + return BTRFS_RAID_DUP; + else if (flags & BTRFS_BLOCK_GROUP_RAID0) + return BTRFS_RAID_RAID0; + else if (flags & BTRFS_BLOCK_GROUP_RAID5) + return BTRFS_RAID_RAID5; + else if (flags & BTRFS_BLOCK_GROUP_RAID6) + return BTRFS_RAID_RAID6; + + return BTRFS_RAID_SINGLE; /* BTRFS_BLOCK_GROUP_SINGLE */ +} + +int get_block_group_index(struct btrfs_block_group_cache *cache) +{ + return __get_raid_index(cache->flags); +} + +static const char *btrfs_raid_type_names[BTRFS_NR_RAID_TYPES] = { + [BTRFS_RAID_RAID10] = "raid10", + [BTRFS_RAID_RAID1] = "raid1", + [BTRFS_RAID_DUP] = "dup", + [BTRFS_RAID_RAID0] = "raid0", + [BTRFS_RAID_SINGLE] = "single", + [BTRFS_RAID_RAID5] = "raid5", + [BTRFS_RAID_RAID6] = "raid6", +}; + +static const char *get_raid_name(enum btrfs_raid_types type) +{ + if (type >= BTRFS_NR_RAID_TYPES) + return NULL; + + return btrfs_raid_type_names[type]; +} + +enum btrfs_loop_type { + LOOP_CACHING_NOWAIT = 0, + LOOP_CACHING_WAIT = 1, + LOOP_ALLOC_CHUNK = 2, + LOOP_NO_EMPTY_SIZE = 3, +}; + +static inline void +btrfs_lock_block_group(struct btrfs_block_group_cache *cache, + int delalloc) +{ + if (delalloc) + down_read(&cache->data_rwsem); +} + +static inline void +btrfs_grab_block_group(struct btrfs_block_group_cache *cache, + int delalloc) +{ + btrfs_get_block_group(cache); + if (delalloc) + down_read(&cache->data_rwsem); +} + +static struct btrfs_block_group_cache * +btrfs_lock_cluster(struct btrfs_block_group_cache *block_group, + struct btrfs_free_cluster *cluster, + int delalloc) +{ + struct btrfs_block_group_cache *used_bg; + bool locked = false; +again: + spin_lock(&cluster->refill_lock); + if (locked) { + if (used_bg == cluster->block_group) + return used_bg; + + up_read(&used_bg->data_rwsem); + btrfs_put_block_group(used_bg); + } + + used_bg = cluster->block_group; + if (!used_bg) + return NULL; + + if (used_bg == block_group) + return used_bg; + + btrfs_get_block_group(used_bg); + + if (!delalloc) + return used_bg; + + if (down_read_trylock(&used_bg->data_rwsem)) + return used_bg; + + spin_unlock(&cluster->refill_lock); + down_read(&used_bg->data_rwsem); + locked = true; + goto again; +} + +static inline void +btrfs_release_block_group(struct btrfs_block_group_cache *cache, + int delalloc) +{ + if (delalloc) + up_read(&cache->data_rwsem); + btrfs_put_block_group(cache); +} + +/* + * walks the btree of allocated extents and find a hole of a given size. + * The key ins is changed to record the hole: + * ins->objectid == start position + * ins->flags = BTRFS_EXTENT_ITEM_KEY + * ins->offset == the size of the hole. + * Any available blocks before search_start are skipped. + * + * If there is no suitable free space, we will record the max size of + * the free space extent currently. + */ +static noinline int find_free_extent(struct btrfs_root *orig_root, + u64 num_bytes, u64 empty_size, + u64 hint_byte, struct btrfs_key *ins, + u64 flags, int delalloc) +{ + 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; + u64 search_start = 0; + u64 max_extent_size = 0; + int empty_cluster = 2 * 1024 * 1024; + struct btrfs_space_info *space_info; + int loop = 0; + int index = __get_raid_index(flags); + int alloc_type = (flags & BTRFS_BLOCK_GROUP_DATA) ? + RESERVE_ALLOC_NO_ACCOUNT : RESERVE_ALLOC; + bool failed_cluster_refill = false; + bool failed_alloc = false; + bool use_cluster = true; + bool have_caching_bg = false; + + WARN_ON(num_bytes < root->sectorsize); + ins->type = BTRFS_EXTENT_ITEM_KEY; + ins->objectid = 0; + ins->offset = 0; + + trace_find_free_extent(orig_root, num_bytes, empty_size, flags); + + space_info = __find_space_info(root->fs_info, flags); + if (!space_info) { + btrfs_err(root->fs_info, "No space info for %llu", flags); + return -ENOSPC; + } + + /* + * If the space info is for both data and metadata it means we have a + * small filesystem and we can't use the clustering stuff. + */ + if (btrfs_mixed_space_info(space_info)) + use_cluster = false; + + if (flags & BTRFS_BLOCK_GROUP_METADATA && use_cluster) { + last_ptr = &root->fs_info->meta_alloc_cluster; + if (!btrfs_test_opt(root, SSD)) + empty_cluster = 64 * 1024; + } + + if ((flags & BTRFS_BLOCK_GROUP_DATA) && use_cluster && + 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) { + 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, flags) && + block_group->cached != BTRFS_CACHE_NO) { + down_read(&space_info->groups_sem); + if (list_empty(&block_group->list) || + block_group->ro) { + /* + * someone is removing this block group, + * we can't jump into the have_block_group + * target because our list pointers are not + * valid + */ + btrfs_put_block_group(block_group); + up_read(&space_info->groups_sem); + } else { + index = get_block_group_index(block_group); + btrfs_lock_block_group(block_group, delalloc); + goto have_block_group; + } + } else if (block_group) { + btrfs_put_block_group(block_group); + } + } +search: + have_caching_bg = false; + down_read(&space_info->groups_sem); + list_for_each_entry(block_group, &space_info->block_groups[index], + list) { + u64 offset; + int cached; + + btrfs_grab_block_group(block_group, delalloc); + search_start = block_group->key.objectid; + + /* + * this can happen if we end up cycling through all the + * raid types, but we want to make sure we only allocate + * for the proper type. + */ + if (!block_group_bits(block_group, flags)) { + u64 extra = BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6 | + BTRFS_BLOCK_GROUP_RAID10; + + /* + * if they asked for extra copies and this block group + * doesn't provide them, bail. This does allow us to + * fill raid0 from raid1. + */ + if ((flags & extra) && !(block_group->flags & extra)) + goto loop; + } + +have_block_group: + cached = block_group_cache_done(block_group); + if (unlikely(!cached)) { + ret = cache_block_group(block_group, 0); + BUG_ON(ret < 0); + ret = 0; + } + + if (unlikely(block_group->cached == BTRFS_CACHE_ERROR)) + goto loop; + if (unlikely(block_group->ro)) + goto loop; + + /* + * Ok we want to try and use the cluster allocator, so + * lets look there + */ + if (last_ptr) { + struct btrfs_block_group_cache *used_block_group; + unsigned long aligned_cluster; + /* + * the refill lock keeps out other + * people trying to start a new cluster + */ + used_block_group = btrfs_lock_cluster(block_group, + last_ptr, + delalloc); + if (!used_block_group) + goto refill_cluster; + + if (used_block_group != block_group && + (used_block_group->ro || + !block_group_bits(used_block_group, flags))) + goto release_cluster; + + offset = btrfs_alloc_from_cluster(used_block_group, + last_ptr, + num_bytes, + used_block_group->key.objectid, + &max_extent_size); + if (offset) { + /* we have a block, we're done */ + spin_unlock(&last_ptr->refill_lock); + trace_btrfs_reserve_extent_cluster(root, + used_block_group, + search_start, num_bytes); + if (used_block_group != block_group) { + btrfs_release_block_group(block_group, + delalloc); + block_group = used_block_group; + } + goto checks; + } + + WARN_ON(last_ptr->block_group != used_block_group); +release_cluster: + /* If we are on LOOP_NO_EMPTY_SIZE, we can't + * set up a new clusters, so lets just skip it + * and let the allocator find whatever block + * it can find. If we reach this point, we + * will have tried the cluster allocator + * plenty of times and not have found + * anything, so we are likely way too + * fragmented for the clustering stuff to find + * anything. + * + * However, if the cluster is taken from the + * current block group, release the cluster + * first, so that we stand a better chance of + * succeeding in the unclustered + * allocation. */ + if (loop >= LOOP_NO_EMPTY_SIZE && + used_block_group != block_group) { + spin_unlock(&last_ptr->refill_lock); + btrfs_release_block_group(used_block_group, + delalloc); + goto unclustered_alloc; + } + + /* + * this cluster didn't work out, free it and + * start over + */ + btrfs_return_cluster_to_free_space(NULL, last_ptr); + + if (used_block_group != block_group) + btrfs_release_block_group(used_block_group, + delalloc); +refill_cluster: + if (loop >= LOOP_NO_EMPTY_SIZE) { + spin_unlock(&last_ptr->refill_lock); + goto unclustered_alloc; + } + + aligned_cluster = max_t(unsigned long, + empty_cluster + empty_size, + block_group->full_stripe_len); + + /* allocate a cluster in this block group */ + ret = btrfs_find_space_cluster(root, block_group, + last_ptr, search_start, + num_bytes, + aligned_cluster); + if (ret == 0) { + /* + * now pull our allocation out of this + * cluster + */ + offset = btrfs_alloc_from_cluster(block_group, + last_ptr, + num_bytes, + search_start, + &max_extent_size); + if (offset) { + /* we found one, proceed */ + spin_unlock(&last_ptr->refill_lock); + trace_btrfs_reserve_extent_cluster(root, + block_group, search_start, + num_bytes); + 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; + } + +unclustered_alloc: + spin_lock(&block_group->free_space_ctl->tree_lock); + if (cached && + block_group->free_space_ctl->free_space < + num_bytes + empty_cluster + empty_size) { + if (block_group->free_space_ctl->free_space > + max_extent_size) + max_extent_size = + block_group->free_space_ctl->free_space; + spin_unlock(&block_group->free_space_ctl->tree_lock); + goto loop; + } + spin_unlock(&block_group->free_space_ctl->tree_lock); + + offset = btrfs_find_space_for_alloc(block_group, search_start, + num_bytes, empty_size, + &max_extent_size); + /* + * If we didn't find a chunk, and we haven't failed on this + * block group before, and this block group is in the middle of + * caching and we are ok with waiting, then go ahead and wait + * for progress to be made, and set 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) { + if (!cached) + have_caching_bg = true; + goto loop; + } +checks: + search_start = ALIGN(offset, root->stripesize); + + /* 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 (offset < search_start) + btrfs_add_free_space(block_group, offset, + search_start - offset); + BUG_ON(offset > search_start); + + ret = btrfs_update_reserved_bytes(block_group, num_bytes, + alloc_type, delalloc); + if (ret == -EAGAIN) { + btrfs_add_free_space(block_group, offset, num_bytes); + goto loop; + } + + /* we are all good, lets return */ + ins->objectid = search_start; + ins->offset = num_bytes; + + trace_btrfs_reserve_extent(orig_root, block_group, + search_start, num_bytes); + btrfs_release_block_group(block_group, delalloc); + break; +loop: + failed_cluster_refill = false; + failed_alloc = false; + BUG_ON(index != get_block_group_index(block_group)); + btrfs_release_block_group(block_group, delalloc); + } + up_read(&space_info->groups_sem); + + if (!ins->objectid && loop >= LOOP_CACHING_WAIT && have_caching_bg) + goto search; + + if (!ins->objectid && ++index < BTRFS_NR_RAID_TYPES) + goto search; + + /* + * 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) { + index = 0; + loop++; + if (loop == LOOP_ALLOC_CHUNK) { + struct btrfs_trans_handle *trans; + int exist = 0; + + trans = current->journal_info; + if (trans) + exist = 1; + else + trans = btrfs_join_transaction(root); + + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + + ret = do_chunk_alloc(trans, root, flags, + CHUNK_ALLOC_FORCE); + /* + * Do not bail out on ENOSPC since we + * can do more things. + */ + if (ret < 0 && ret != -ENOSPC) + btrfs_abort_transaction(trans, + root, ret); + else + ret = 0; + if (!exist) + btrfs_end_transaction(trans, root); + if (ret) + goto out; + } + + if (loop == LOOP_NO_EMPTY_SIZE) { + empty_size = 0; + empty_cluster = 0; + } + + goto search; + } else if (!ins->objectid) { + ret = -ENOSPC; + } else if (ins->objectid) { + ret = 0; + } +out: + if (ret == -ENOSPC) + ins->offset = max_extent_size; + return ret; +} + +static void dump_space_info(struct btrfs_space_info *info, u64 bytes, + int dump_block_groups) +{ + struct btrfs_block_group_cache *cache; + int index = 0; + + spin_lock(&info->lock); + printk(KERN_INFO "BTRFS: space_info %llu has %llu free, is %sfull\n", + info->flags, + info->total_bytes - info->bytes_used - info->bytes_pinned - + info->bytes_reserved - info->bytes_readonly, + (info->full) ? "" : "not "); + printk(KERN_INFO "BTRFS: space_info total=%llu, used=%llu, pinned=%llu, " + "reserved=%llu, may_use=%llu, readonly=%llu\n", + info->total_bytes, info->bytes_used, info->bytes_pinned, + info->bytes_reserved, info->bytes_may_use, + info->bytes_readonly); + spin_unlock(&info->lock); + + if (!dump_block_groups) + return; + + down_read(&info->groups_sem); +again: + list_for_each_entry(cache, &info->block_groups[index], list) { + spin_lock(&cache->lock); + printk(KERN_INFO "BTRFS: " + "block group %llu has %llu bytes, " + "%llu used %llu pinned %llu reserved %s\n", + cache->key.objectid, cache->key.offset, + btrfs_block_group_used(&cache->item), cache->pinned, + cache->reserved, cache->ro ? "[readonly]" : ""); + btrfs_dump_free_space(cache, bytes); + spin_unlock(&cache->lock); + } + if (++index < BTRFS_NR_RAID_TYPES) + goto again; + up_read(&info->groups_sem); +} + +int btrfs_reserve_extent(struct btrfs_root *root, + u64 num_bytes, u64 min_alloc_size, + u64 empty_size, u64 hint_byte, + struct btrfs_key *ins, int is_data, int delalloc) +{ + bool final_tried = false; + u64 flags; + int ret; + + flags = btrfs_get_alloc_profile(root, is_data); +again: + WARN_ON(num_bytes < root->sectorsize); + ret = find_free_extent(root, num_bytes, empty_size, hint_byte, ins, + flags, delalloc); + + if (ret == -ENOSPC) { + if (!final_tried && ins->offset) { + num_bytes = min(num_bytes >> 1, ins->offset); + num_bytes = round_down(num_bytes, root->sectorsize); + num_bytes = max(num_bytes, min_alloc_size); + if (num_bytes == min_alloc_size) + final_tried = true; + goto again; + } else if (btrfs_test_opt(root, ENOSPC_DEBUG)) { + struct btrfs_space_info *sinfo; + + sinfo = __find_space_info(root->fs_info, flags); + btrfs_err(root->fs_info, "allocation failed flags %llu, wanted %llu", + flags, num_bytes); + if (sinfo) + dump_space_info(sinfo, num_bytes, 1); + } + } + + return ret; +} + +static int __btrfs_free_reserved_extent(struct btrfs_root *root, + u64 start, u64 len, + int pin, int delalloc) +{ + struct btrfs_block_group_cache *cache; + int ret = 0; + + cache = btrfs_lookup_block_group(root->fs_info, start); + if (!cache) { + btrfs_err(root->fs_info, "Unable to find block group for %llu", + start); + return -ENOSPC; + } + + if (pin) + pin_down_extent(root, cache, start, len, 1); + else { + if (btrfs_test_opt(root, DISCARD)) + ret = btrfs_discard_extent(root, start, len, NULL); + btrfs_add_free_space(cache, start, len); + btrfs_update_reserved_bytes(cache, len, RESERVE_FREE, delalloc); + } + + btrfs_put_block_group(cache); + + trace_btrfs_reserved_extent_free(root, start, len); + + return ret; +} + +int btrfs_free_reserved_extent(struct btrfs_root *root, + u64 start, u64 len, int delalloc) +{ + return __btrfs_free_reserved_extent(root, start, len, 0, delalloc); +} + +int btrfs_free_and_pin_reserved_extent(struct btrfs_root *root, + u64 start, u64 len) +{ + return __btrfs_free_reserved_extent(root, start, len, 1, 0); +} + +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(); + if (!path) + return -ENOMEM; + + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, + ins, size); + if (ret) { + btrfs_free_path(path); + return ret; + } + + leaf = path->nodes[0]; + extent_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_item); + btrfs_set_extent_refs(leaf, extent_item, ref_mod); + btrfs_set_extent_generation(leaf, extent_item, trans->transid); + btrfs_set_extent_flags(leaf, extent_item, + flags | BTRFS_EXTENT_FLAG_DATA); + + iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); + btrfs_set_extent_inline_ref_type(leaf, iref, type); + if (parent > 0) { + struct btrfs_shared_data_ref *ref; + ref = (struct btrfs_shared_data_ref *)(iref + 1); + btrfs_set_extent_inline_ref_offset(leaf, iref, parent); + btrfs_set_shared_data_ref_count(leaf, ref, ref_mod); + } else { + struct btrfs_extent_data_ref *ref; + ref = (struct btrfs_extent_data_ref *)(&iref->offset); + btrfs_set_extent_data_ref_root(leaf, ref, root_objectid); + btrfs_set_extent_data_ref_objectid(leaf, ref, owner); + btrfs_set_extent_data_ref_offset(leaf, ref, offset); + btrfs_set_extent_data_ref_count(leaf, ref, ref_mod); + } + + btrfs_mark_buffer_dirty(path->nodes[0]); + btrfs_free_path(path); + + /* Always set parent to 0 here since its exclusive anyway. */ + ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid, + ins->objectid, ins->offset, + BTRFS_QGROUP_OPER_ADD_EXCL, 0); + if (ret) + return ret; + + ret = update_block_group(trans, root, ins->objectid, ins->offset, 1); + if (ret) { /* -ENOENT, logic error */ + btrfs_err(fs_info, "update block group failed for %llu %llu", + ins->objectid, ins->offset); + BUG(); + } + trace_btrfs_reserved_extent_alloc(root, ins->objectid, ins->offset); + 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 no_quota) +{ + 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(*iref); + u64 num_bytes = ins->offset; + bool skinny_metadata = btrfs_fs_incompat(root->fs_info, + SKINNY_METADATA); + + if (!skinny_metadata) + size += sizeof(*block_info); + + path = btrfs_alloc_path(); + if (!path) { + btrfs_free_and_pin_reserved_extent(root, ins->objectid, + root->nodesize); + return -ENOMEM; + } + + path->leave_spinning = 1; + ret = btrfs_insert_empty_item(trans, fs_info->extent_root, path, + ins, size); + if (ret) { + btrfs_free_path(path); + btrfs_free_and_pin_reserved_extent(root, ins->objectid, + root->nodesize); + return ret; + } + + leaf = path->nodes[0]; + extent_item = btrfs_item_ptr(leaf, path->slots[0], + struct btrfs_extent_item); + btrfs_set_extent_refs(leaf, extent_item, 1); + btrfs_set_extent_generation(leaf, extent_item, trans->transid); + btrfs_set_extent_flags(leaf, extent_item, + flags | BTRFS_EXTENT_FLAG_TREE_BLOCK); + + if (skinny_metadata) { + iref = (struct btrfs_extent_inline_ref *)(extent_item + 1); + num_bytes = root->nodesize; + } else { + 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); + + if (!no_quota) { + ret = btrfs_qgroup_record_ref(trans, fs_info, root_objectid, + ins->objectid, num_bytes, + BTRFS_QGROUP_OPER_ADD_EXCL, 0); + if (ret) + return ret; + } + + ret = update_block_group(trans, root, ins->objectid, root->nodesize, + 1); + if (ret) { /* -ENOENT, logic error */ + btrfs_err(fs_info, "update block group failed for %llu %llu", + ins->objectid, ins->offset); + BUG(); + } + + trace_btrfs_reserved_extent_alloc(root, ins->objectid, root->nodesize); + 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(root->fs_info, trans, ins->objectid, + ins->offset, 0, + root_objectid, owner, offset, + BTRFS_ADD_DELAYED_EXTENT, NULL, 0); + 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; + + /* + * Mixed block groups will exclude before processing the log so we only + * need to do the exlude dance if this fs isn't mixed. + */ + if (!btrfs_fs_incompat(root->fs_info, MIXED_GROUPS)) { + ret = __exclude_logged_extent(root, ins->objectid, ins->offset); + if (ret) + return ret; + } + + block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); + if (!block_group) + return -EINVAL; + + ret = btrfs_update_reserved_bytes(block_group, ins->offset, + RESERVE_ALLOC_NO_ACCOUNT, 0); + BUG_ON(ret); /* logic error */ + ret = alloc_reserved_file_extent(trans, root, 0, root_objectid, + 0, owner, offset, ins, 1); + btrfs_put_block_group(block_group); + return ret; +} + +static struct extent_buffer * +btrfs_init_new_buffer(struct btrfs_trans_handle *trans, struct btrfs_root *root, + u64 bytenr, int level) +{ + struct extent_buffer *buf; + + buf = btrfs_find_create_tree_block(root, bytenr); + if (!buf) + return ERR_PTR(-ENOMEM); + btrfs_set_header_generation(buf, trans->transid); + btrfs_set_buffer_lockdep_class(root->root_key.objectid, buf, level); + btrfs_tree_lock(buf); + clean_tree_block(trans, root->fs_info, buf); + clear_bit(EXTENT_BUFFER_STALE, &buf->bflags); + + btrfs_set_lock_blocking(buf); + btrfs_set_buffer_uptodate(buf); + + if (root->root_key.objectid == BTRFS_TREE_LOG_OBJECTID) { + buf->log_index = root->log_transid % 2; + /* + * we allow two log transactions at a time, use different + * EXENT bit to differentiate dirty pages. + */ + if (buf->log_index == 0) + set_extent_dirty(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + else + set_extent_new(&root->dirty_log_pages, buf->start, + buf->start + buf->len - 1, GFP_NOFS); + } else { + buf->log_index = -1; + 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; +} + +static struct btrfs_block_rsv * +use_block_rsv(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u32 blocksize) +{ + struct btrfs_block_rsv *block_rsv; + struct btrfs_block_rsv *global_rsv = &root->fs_info->global_block_rsv; + int ret; + bool global_updated = false; + + block_rsv = get_block_rsv(trans, root); + + if (unlikely(block_rsv->size == 0)) + goto try_reserve; +again: + ret = block_rsv_use_bytes(block_rsv, blocksize); + if (!ret) + return block_rsv; + + if (block_rsv->failfast) + return ERR_PTR(ret); + + if (block_rsv->type == BTRFS_BLOCK_RSV_GLOBAL && !global_updated) { + global_updated = true; + update_global_block_rsv(root->fs_info); + goto again; + } + + if (btrfs_test_opt(root, ENOSPC_DEBUG)) { + static DEFINE_RATELIMIT_STATE(_rs, + DEFAULT_RATELIMIT_INTERVAL * 10, + /*DEFAULT_RATELIMIT_BURST*/ 1); + if (__ratelimit(&_rs)) + WARN(1, KERN_DEBUG + "BTRFS: block rsv returned %d\n", ret); + } +try_reserve: + ret = reserve_metadata_bytes(root, block_rsv, blocksize, + BTRFS_RESERVE_NO_FLUSH); + if (!ret) + return block_rsv; + /* + * If we couldn't reserve metadata bytes try and use some from + * the global reserve if its space type is the same as the global + * reservation. + */ + if (block_rsv->type != BTRFS_BLOCK_RSV_GLOBAL && + block_rsv->space_info == global_rsv->space_info) { + ret = block_rsv_use_bytes(global_rsv, blocksize); + if (!ret) + return global_rsv; + } + return ERR_PTR(ret); +} + +static void unuse_block_rsv(struct btrfs_fs_info *fs_info, + struct btrfs_block_rsv *block_rsv, u32 blocksize) +{ + block_rsv_add_bytes(block_rsv, blocksize, 0); + block_rsv_release_bytes(fs_info, block_rsv, NULL, 0); +} + +/* + * 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 the tree buffer or an ERR_PTR on error. + */ +struct extent_buffer *btrfs_alloc_tree_block(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + u64 parent, u64 root_objectid, + struct btrfs_disk_key *key, int level, + u64 hint, u64 empty_size) +{ + struct btrfs_key ins; + struct btrfs_block_rsv *block_rsv; + struct extent_buffer *buf; + struct btrfs_delayed_extent_op *extent_op; + u64 flags = 0; + int ret; + u32 blocksize = root->nodesize; + bool skinny_metadata = btrfs_fs_incompat(root->fs_info, + SKINNY_METADATA); + + if (btrfs_test_is_dummy_root(root)) { + buf = btrfs_init_new_buffer(trans, root, root->alloc_bytenr, + level); + if (!IS_ERR(buf)) + root->alloc_bytenr += blocksize; + return buf; + } + + block_rsv = use_block_rsv(trans, root, blocksize); + if (IS_ERR(block_rsv)) + return ERR_CAST(block_rsv); + + ret = btrfs_reserve_extent(root, blocksize, blocksize, + empty_size, hint, &ins, 0, 0); + if (ret) + goto out_unuse; + + buf = btrfs_init_new_buffer(trans, root, ins.objectid, level); + if (IS_ERR(buf)) { + ret = PTR_ERR(buf); + goto out_free_reserved; + } + + if (root_objectid == BTRFS_TREE_RELOC_OBJECTID) { + if (parent == 0) + parent = ins.objectid; + flags |= BTRFS_BLOCK_FLAG_FULL_BACKREF; + } else + BUG_ON(parent > 0); + + if (root_objectid != BTRFS_TREE_LOG_OBJECTID) { + extent_op = btrfs_alloc_delayed_extent_op(); + if (!extent_op) { + ret = -ENOMEM; + goto out_free_buf; + } + if (key) + memcpy(&extent_op->key, key, sizeof(extent_op->key)); + else + memset(&extent_op->key, 0, sizeof(extent_op->key)); + extent_op->flags_to_set = flags; + if (skinny_metadata) + extent_op->update_key = 0; + else + extent_op->update_key = 1; + extent_op->update_flags = 1; + extent_op->is_data = 0; + extent_op->level = level; + + ret = btrfs_add_delayed_tree_ref(root->fs_info, trans, + ins.objectid, ins.offset, + parent, root_objectid, level, + BTRFS_ADD_DELAYED_EXTENT, + extent_op, 0); + if (ret) + goto out_free_delayed; + } + return buf; + +out_free_delayed: + btrfs_free_delayed_extent_op(extent_op); +out_free_buf: + free_extent_buffer(buf); +out_free_reserved: + btrfs_free_reserved_extent(root, ins.objectid, ins.offset, 0); +out_unuse: + unuse_block_rsv(root->fs_info, block_rsv, blocksize); + return ERR_PTR(ret); +} + +struct walk_control { + u64 refs[BTRFS_MAX_LEVEL]; + u64 flags[BTRFS_MAX_LEVEL]; + struct btrfs_key update_progress; + int stage; + int level; + int shared_level; + int update_ref; + int keep_locks; + int reada_slot; + int reada_count; + int for_reloc; +}; + +#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; + 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 = root->nodesize; + + 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, + wc->level - 1, 1, &refs, + &flags); + /* We don't care about errors in readahead. */ + if (ret < 0) + continue; + BUG_ON(refs == 0); + + if (wc->stage == DROP_REFERENCE) { + if (refs == 1) + goto reada; + + if (wc->level == 1 && + (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + continue; + if (!wc->update_ref || + generation <= root->root_key.offset) + continue; + btrfs_node_key_to_cpu(eb, &key, slot); + ret = btrfs_comp_cpu_keys(&key, + &wc->update_progress); + if (ret < 0) + continue; + } else { + if (wc->level == 1 && + (flags & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + continue; + } +reada: + readahead_tree_block(root, bytenr); + nread++; + } + wc->reada_slot = slot; +} + +static int account_leaf_items(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *eb) +{ + int nr = btrfs_header_nritems(eb); + int i, extent_type, ret; + struct btrfs_key key; + struct btrfs_file_extent_item *fi; + u64 bytenr, num_bytes; + + for (i = 0; i < nr; i++) { + btrfs_item_key_to_cpu(eb, &key, i); + + if (key.type != BTRFS_EXTENT_DATA_KEY) + continue; + + fi = btrfs_item_ptr(eb, i, struct btrfs_file_extent_item); + /* filter out non qgroup-accountable extents */ + extent_type = btrfs_file_extent_type(eb, fi); + + if (extent_type == BTRFS_FILE_EXTENT_INLINE) + continue; + + bytenr = btrfs_file_extent_disk_bytenr(eb, fi); + if (!bytenr) + continue; + + num_bytes = btrfs_file_extent_disk_num_bytes(eb, fi); + + ret = btrfs_qgroup_record_ref(trans, root->fs_info, + root->objectid, + bytenr, num_bytes, + BTRFS_QGROUP_OPER_SUB_SUBTREE, 0); + if (ret) + return ret; + } + return 0; +} + +/* + * Walk up the tree from the bottom, freeing leaves and any interior + * nodes which have had all slots visited. If a node (leaf or + * interior) is freed, the node above it will have it's slot + * incremented. The root node will never be freed. + * + * At the end of this function, we should have a path which has all + * slots incremented to the next position for a search. If we need to + * read a new node it will be NULL and the node above it will have the + * correct slot selected for a later read. + * + * If we increment the root nodes slot counter past the number of + * elements, 1 is returned to signal completion of the search. + */ +static int adjust_slots_upwards(struct btrfs_root *root, + struct btrfs_path *path, int root_level) +{ + int level = 0; + int nr, slot; + struct extent_buffer *eb; + + if (root_level == 0) + return 1; + + while (level <= root_level) { + eb = path->nodes[level]; + nr = btrfs_header_nritems(eb); + path->slots[level]++; + slot = path->slots[level]; + if (slot >= nr || level == 0) { + /* + * Don't free the root - we will detect this + * condition after our loop and return a + * positive value for caller to stop walking the tree. + */ + if (level != root_level) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + + free_extent_buffer(eb); + path->nodes[level] = NULL; + path->slots[level] = 0; + } + } else { + /* + * We have a valid slot to walk back down + * from. Stop here so caller can process these + * new nodes. + */ + break; + } + + level++; + } + + eb = path->nodes[root_level]; + if (path->slots[root_level] >= btrfs_header_nritems(eb)) + return 1; + + return 0; +} + +/* + * root_eb is the subtree root and is locked before this function is called. + */ +static int account_shared_subtree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *root_eb, + u64 root_gen, + int root_level) +{ + int ret = 0; + int level; + struct extent_buffer *eb = root_eb; + struct btrfs_path *path = NULL; + + BUG_ON(root_level < 0 || root_level > BTRFS_MAX_LEVEL); + BUG_ON(root_eb == NULL); + + if (!root->fs_info->quota_enabled) + return 0; + + if (!extent_buffer_uptodate(root_eb)) { + ret = btrfs_read_buffer(root_eb, root_gen); + if (ret) + goto out; + } + + if (root_level == 0) { + ret = account_leaf_items(trans, root, root_eb); + goto out; + } + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + /* + * Walk down the tree. Missing extent blocks are filled in as + * we go. Metadata is accounted every time we read a new + * extent block. + * + * When we reach a leaf, we account for file extent items in it, + * walk back up the tree (adjusting slot pointers as we go) + * and restart the search process. + */ + extent_buffer_get(root_eb); /* For path */ + path->nodes[root_level] = root_eb; + path->slots[root_level] = 0; + path->locks[root_level] = 0; /* so release_path doesn't try to unlock */ +walk_down: + level = root_level; + while (level >= 0) { + if (path->nodes[level] == NULL) { + int parent_slot; + u64 child_gen; + u64 child_bytenr; + + /* We need to get child blockptr/gen from + * parent before we can read it. */ + eb = path->nodes[level + 1]; + parent_slot = path->slots[level + 1]; + child_bytenr = btrfs_node_blockptr(eb, parent_slot); + child_gen = btrfs_node_ptr_generation(eb, parent_slot); + + eb = read_tree_block(root, child_bytenr, child_gen); + if (!eb || !extent_buffer_uptodate(eb)) { + ret = -EIO; + goto out; + } + + path->nodes[level] = eb; + path->slots[level] = 0; + + btrfs_tree_read_lock(eb); + btrfs_set_lock_blocking_rw(eb, BTRFS_READ_LOCK); + path->locks[level] = BTRFS_READ_LOCK_BLOCKING; + + ret = btrfs_qgroup_record_ref(trans, root->fs_info, + root->objectid, + child_bytenr, + root->nodesize, + BTRFS_QGROUP_OPER_SUB_SUBTREE, + 0); + if (ret) + goto out; + + } + + if (level == 0) { + ret = account_leaf_items(trans, root, path->nodes[level]); + if (ret) + goto out; + + /* Nonzero return here means we completed our search */ + ret = adjust_slots_upwards(root, path, root_level); + if (ret) + break; + + /* Restart search with new slots */ + goto walk_down; + } + + level--; + } + + ret = 0; +out: + btrfs_free_path(path); + + return ret; +} + +/* + * helper to process tree block while walking down the tree. + * + * when wc->stage == UPDATE_BACKREF, this function updates + * back refs for pointers in the block. + * + * NOTE: return value 1 means we should stop walking down. + */ +static noinline int walk_down_proc(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct walk_control *wc, int lookup_info) +{ + 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, level, 1, + &wc->refs[level], + &wc->flags[level]); + BUG_ON(ret == -ENOMEM); + if (ret) + return ret; + BUG_ON(wc->refs[level] == 0); + } + + if (wc->stage == DROP_REFERENCE) { + if (wc->refs[level] > 1) + return 1; + + if (path->locks[level] && !wc->keep_locks) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + } + return 0; + } + + /* wc->stage == UPDATE_BACKREF */ + if (!(wc->flags[level] & flag)) { + BUG_ON(!path->locks[level]); + ret = btrfs_inc_ref(trans, root, eb, 1); + BUG_ON(ret); /* -ENOMEM */ + ret = btrfs_dec_ref(trans, root, eb, 0); + BUG_ON(ret); /* -ENOMEM */ + ret = btrfs_set_disk_extent_flags(trans, root, eb->start, + eb->len, flag, + btrfs_header_level(eb), 0); + BUG_ON(ret); /* -ENOMEM */ + wc->flags[level] |= flag; + } + + /* + * the block is shared by multiple trees, so it's not good to + * keep the tree lock + */ + if (path->locks[level] && level > 0) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + } + return 0; +} + +/* + * helper to process tree block pointer. + * + * when wc->stage == DROP_REFERENCE, this function checks + * reference count of the block pointed to. if the block + * is shared and we need update back refs for the subtree + * rooted at the block, this function changes wc->stage to + * UPDATE_BACKREF. if the block is shared and there is no + * need to update back, this function drops the reference + * to the block. + * + * NOTE: return value 1 means we should stop walking down. + */ +static noinline int do_walk_down(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct walk_control *wc, int *lookup_info) +{ + 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; + bool need_account = false; + + generation = btrfs_node_ptr_generation(path->nodes[level], + path->slots[level]); + /* + * if the lower level block was created before the snapshot + * was created, we know there is no need to update back refs + * for the subtree + */ + if (wc->stage == UPDATE_BACKREF && + generation <= root->root_key.offset) { + *lookup_info = 1; + return 1; + } + + bytenr = btrfs_node_blockptr(path->nodes[level], path->slots[level]); + blocksize = root->nodesize; + + next = btrfs_find_tree_block(root->fs_info, bytenr); + if (!next) { + next = btrfs_find_create_tree_block(root, bytenr); + if (!next) + return -ENOMEM; + btrfs_set_buffer_lockdep_class(root->root_key.objectid, next, + level - 1); + reada = 1; + } + btrfs_tree_lock(next); + btrfs_set_lock_blocking(next); + + ret = btrfs_lookup_extent_info(trans, root, bytenr, level - 1, 1, + &wc->refs[level - 1], + &wc->flags[level - 1]); + if (ret < 0) { + btrfs_tree_unlock(next); + return ret; + } + + if (unlikely(wc->refs[level - 1] == 0)) { + btrfs_err(root->fs_info, "Missing references."); + BUG(); + } + *lookup_info = 0; + + if (wc->stage == DROP_REFERENCE) { + if (wc->refs[level - 1] > 1) { + need_account = true; + if (level == 1 && + (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + goto skip; + + if (!wc->update_ref || + generation <= root->root_key.offset) + goto skip; + + btrfs_node_key_to_cpu(path->nodes[level], &key, + path->slots[level]); + ret = btrfs_comp_cpu_keys(&key, &wc->update_progress); + if (ret < 0) + goto skip; + + wc->stage = UPDATE_BACKREF; + wc->shared_level = level - 1; + } + } else { + if (level == 1 && + (wc->flags[0] & BTRFS_BLOCK_FLAG_FULL_BACKREF)) + goto skip; + } + + if (!btrfs_buffer_uptodate(next, generation, 0)) { + btrfs_tree_unlock(next); + free_extent_buffer(next); + next = NULL; + *lookup_info = 1; + } + + if (!next) { + if (reada && level == 1) + reada_walk_down(trans, root, wc, path); + next = read_tree_block(root, bytenr, generation); + if (!next || !extent_buffer_uptodate(next)) { + free_extent_buffer(next); + return -EIO; + } + 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] = BTRFS_WRITE_LOCK_BLOCKING; + wc->level = level; + if (wc->level == 1) + wc->reada_slot = 0; + return 0; +skip: + wc->refs[level - 1] = 0; + wc->flags[level - 1] = 0; + if (wc->stage == DROP_REFERENCE) { + if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) { + parent = path->nodes[level]->start; + } else { + BUG_ON(root->root_key.objectid != + btrfs_header_owner(path->nodes[level])); + parent = 0; + } + + if (need_account) { + ret = account_shared_subtree(trans, root, next, + generation, level - 1); + if (ret) { + printk_ratelimited(KERN_ERR "BTRFS: %s Error " + "%d accounting shared subtree. Quota " + "is out of sync, rescan required.\n", + root->fs_info->sb->s_id, ret); + } + } + ret = btrfs_free_extent(trans, root, bytenr, blocksize, parent, + root->root_key.objectid, level - 1, 0, 0); + BUG_ON(ret); /* -ENOMEM */ + } + btrfs_tree_unlock(next); + free_extent_buffer(next); + *lookup_info = 1; + return 1; +} + +/* + * helper to process tree block while walking up the tree. + * + * when wc->stage == DROP_REFERENCE, this function drops + * reference count on the block. + * + * when wc->stage == UPDATE_BACKREF, this function changes + * wc->stage back to DROP_REFERENCE if we changed wc->stage + * to UPDATE_BACKREF previously while processing the block. + * + * NOTE: return value 1 means we should stop walking up. + */ +static noinline int walk_up_proc(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct btrfs_path *path, + struct walk_control *wc) +{ + int ret; + int level = wc->level; + struct extent_buffer *eb = path->nodes[level]; + u64 parent = 0; + + if (wc->stage == UPDATE_BACKREF) { + BUG_ON(wc->shared_level < level); + if (level < wc->shared_level) + goto out; + + ret = find_next_key(path, level + 1, &wc->update_progress); + if (ret > 0) + wc->update_ref = 0; + + wc->stage = DROP_REFERENCE; + wc->shared_level = -1; + path->slots[level] = 0; + + /* + * check reference count again if the block isn't locked. + * we should start walking down the tree again if reference + * count is one. + */ + if (!path->locks[level]) { + BUG_ON(level == 0); + btrfs_tree_lock(eb); + btrfs_set_lock_blocking(eb); + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; + + ret = btrfs_lookup_extent_info(trans, root, + eb->start, level, 1, + &wc->refs[level], + &wc->flags[level]); + if (ret < 0) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + return ret; + } + BUG_ON(wc->refs[level] == 0); + if (wc->refs[level] == 1) { + btrfs_tree_unlock_rw(eb, path->locks[level]); + path->locks[level] = 0; + return 1; + } + } + } + + /* wc->stage == DROP_REFERENCE */ + BUG_ON(wc->refs[level] > 1 && !path->locks[level]); + + if (wc->refs[level] == 1) { + if (level == 0) { + if (wc->flags[level] & BTRFS_BLOCK_FLAG_FULL_BACKREF) + ret = btrfs_dec_ref(trans, root, eb, 1); + else + ret = btrfs_dec_ref(trans, root, eb, 0); + BUG_ON(ret); /* -ENOMEM */ + ret = account_leaf_items(trans, root, eb); + if (ret) { + printk_ratelimited(KERN_ERR "BTRFS: %s Error " + "%d accounting leaf items. Quota " + "is out of sync, rescan required.\n", + root->fs_info->sb->s_id, 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] = BTRFS_WRITE_LOCK_BLOCKING; + } + clean_tree_block(trans, root->fs_info, 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])); + } + + btrfs_free_tree_block(trans, root, eb, parent, wc->refs[level] == 1); +out: + wc->refs[level] = 0; + wc->flags[level] = 0; + return 0; +} + +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_rw(path->nodes[level], + path->locks[level]); + path->locks[level] = 0; + } + free_extent_buffer(path->nodes[level]); + path->nodes[level] = NULL; + level++; + } + } + return 1; +} + +/* + * drop a subvolume tree. + * + * this function traverses the tree freeing any blocks that only + * referenced by the tree. + * + * when a shared tree block is found. this function decreases its + * reference count by one. if update_ref is true, this function + * also make sure backrefs for the shared block and all lower level + * blocks are properly updated. + * + * If called with for_reloc == 0, may exit early with -EAGAIN + */ +int btrfs_drop_snapshot(struct btrfs_root *root, + struct btrfs_block_rsv *block_rsv, int update_ref, + int for_reloc) +{ + struct btrfs_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; + bool root_dropped = false; + + btrfs_debug(root->fs_info, "Drop subvolume %llu", root->objectid); + + path = btrfs_alloc_path(); + if (!path) { + err = -ENOMEM; + goto out; + } + + wc = kzalloc(sizeof(*wc), GFP_NOFS); + if (!wc) { + btrfs_free_path(path); + err = -ENOMEM; + goto out; + } + + trans = btrfs_start_transaction(tree_root, 0); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out_free; + } + + if (block_rsv) + trans->block_rsv = block_rsv; + + 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] = BTRFS_WRITE_LOCK_BLOCKING; + memset(&wc->update_progress, 0, + sizeof(wc->update_progress)); + } else { + btrfs_disk_key_to_cpu(&key, &root_item->drop_progress); + memcpy(&wc->update_progress, &key, + sizeof(wc->update_progress)); + + level = root_item->drop_level; + BUG_ON(level == 0); + path->lowest_level = level; + ret = btrfs_search_slot(NULL, root, &key, path, 0, 0); + path->lowest_level = 0; + if (ret < 0) { + err = ret; + goto out_end_trans; + } + WARN_ON(ret > 0); + + /* + * unlock our path, this is safe because only this + * function is allowed to delete this snapshot + */ + btrfs_unlock_up_safe(path, 0); + + level = btrfs_header_level(root->node); + while (1) { + btrfs_tree_lock(path->nodes[level]); + btrfs_set_lock_blocking(path->nodes[level]); + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; + + ret = btrfs_lookup_extent_info(trans, root, + path->nodes[level]->start, + level, 1, &wc->refs[level], + &wc->flags[level]); + if (ret < 0) { + err = ret; + goto out_end_trans; + } + BUG_ON(wc->refs[level] == 0); + + if (level == root_item->drop_level) + break; + + btrfs_tree_unlock(path->nodes[level]); + path->locks[level] = 0; + WARN_ON(wc->refs[level] != 1); + level--; + } + } + + wc->level = level; + wc->shared_level = -1; + wc->stage = DROP_REFERENCE; + wc->update_ref = update_ref; + wc->keep_locks = 0; + wc->for_reloc = for_reloc; + 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 (btrfs_should_end_transaction(trans, tree_root) || + (!for_reloc && btrfs_need_cleaner_sleep(root))) { + ret = btrfs_update_root(trans, tree_root, + &root->root_key, + root_item); + if (ret) { + btrfs_abort_transaction(trans, tree_root, ret); + err = ret; + goto out_end_trans; + } + + /* + * Qgroup update accounting is run from + * delayed ref handling. This usually works + * out because delayed refs are normally the + * only way qgroup updates are added. However, + * we may have added updates during our tree + * walk so run qgroups here to make sure we + * don't lose any updates. + */ + ret = btrfs_delayed_qgroup_accounting(trans, + root->fs_info); + if (ret) + printk_ratelimited(KERN_ERR "BTRFS: Failure %d " + "running qgroup updates " + "during snapshot delete. " + "Quota is out of sync, " + "rescan required.\n", ret); + + btrfs_end_transaction_throttle(trans, tree_root); + if (!for_reloc && btrfs_need_cleaner_sleep(root)) { + pr_debug("BTRFS: drop snapshot early exit\n"); + err = -EAGAIN; + goto out_free; + } + + trans = btrfs_start_transaction(tree_root, 0); + if (IS_ERR(trans)) { + err = PTR_ERR(trans); + goto out_free; + } + if (block_rsv) + trans->block_rsv = block_rsv; + } + } + btrfs_release_path(path); + if (err) + goto out_end_trans; + + ret = btrfs_del_root(trans, tree_root, &root->root_key); + if (ret) { + btrfs_abort_transaction(trans, tree_root, ret); + goto out_end_trans; + } + + if (root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID) { + ret = btrfs_find_root(tree_root, &root->root_key, path, + NULL, NULL); + if (ret < 0) { + btrfs_abort_transaction(trans, tree_root, ret); + err = ret; + goto out_end_trans; + } else if (ret > 0) { + /* if we fail to delete the orphan item this time + * around, it'll get picked up the next time. + * + * The most common failure here is just -ENOENT. + */ + btrfs_del_orphan_item(trans, tree_root, + root->root_key.objectid); + } + } + + if (test_bit(BTRFS_ROOT_IN_RADIX, &root->state)) { + btrfs_drop_and_free_fs_root(tree_root->fs_info, root); + } else { + free_extent_buffer(root->node); + free_extent_buffer(root->commit_root); + btrfs_put_fs_root(root); + } + root_dropped = true; +out_end_trans: + ret = btrfs_delayed_qgroup_accounting(trans, tree_root->fs_info); + if (ret) + printk_ratelimited(KERN_ERR "BTRFS: Failure %d " + "running qgroup updates " + "during snapshot delete. " + "Quota is out of sync, " + "rescan required.\n", ret); + + btrfs_end_transaction_throttle(trans, tree_root); +out_free: + kfree(wc); + btrfs_free_path(path); +out: + /* + * So if we need to stop dropping the snapshot for whatever reason we + * need to make sure to add it back to the dead root list so that we + * keep trying to do the work later. This also cleans up roots if we + * don't have it in the radix (like when we recover after a power fail + * or unmount) so we don't leak memory. + */ + if (!for_reloc && root_dropped == false) + btrfs_add_dead_root(root); + if (err && err != -EAGAIN) + btrfs_std_error(root->fs_info, err); + return err; +} + +/* + * drop subtree rooted at tree block 'node'. + * + * NOTE: this function will unlock and release tree block 'node' + * only used by relocation code + */ +int btrfs_drop_subtree(struct btrfs_trans_handle *trans, + struct btrfs_root *root, + struct extent_buffer *node, + struct extent_buffer *parent) +{ + struct btrfs_path *path; + struct walk_control *wc; + int level; + int parent_level; + int ret = 0; + int wret; + + BUG_ON(root->root_key.objectid != BTRFS_TREE_RELOC_OBJECTID); + + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + + wc = kzalloc(sizeof(*wc), GFP_NOFS); + if (!wc) { + btrfs_free_path(path); + return -ENOMEM; + } + + btrfs_assert_tree_locked(parent); + parent_level = btrfs_header_level(parent); + extent_buffer_get(parent); + path->nodes[parent_level] = parent; + path->slots[parent_level] = btrfs_header_nritems(parent); + + btrfs_assert_tree_locked(node); + level = btrfs_header_level(node); + path->nodes[level] = node; + path->slots[level] = 0; + path->locks[level] = BTRFS_WRITE_LOCK_BLOCKING; + + wc->refs[parent_level] = 1; + wc->flags[parent_level] = BTRFS_BLOCK_FLAG_FULL_BACKREF; + wc->level = level; + wc->shared_level = -1; + wc->stage = DROP_REFERENCE; + wc->update_ref = 0; + wc->keep_locks = 1; + wc->for_reloc = 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; +} + +static u64 update_block_group_flags(struct btrfs_root *root, u64 flags) +{ + u64 num_devices; + u64 stripped; + + /* + * if restripe for this chunk_type is on pick target profile and + * return, otherwise do the usual balance + */ + stripped = get_restripe_target(root->fs_info, flags); + if (stripped) + return extended_to_chunk(stripped); + + num_devices = root->fs_info->fs_devices->rw_devices; + + stripped = BTRFS_BLOCK_GROUP_RAID0 | + BTRFS_BLOCK_GROUP_RAID5 | BTRFS_BLOCK_GROUP_RAID6 | + BTRFS_BLOCK_GROUP_RAID1 | BTRFS_BLOCK_GROUP_RAID10; + + if (num_devices == 1) { + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* turn raid0 into single device chunks */ + if (flags & BTRFS_BLOCK_GROUP_RAID0) + return stripped; + + /* turn mirroring into duplication */ + if (flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + return stripped | BTRFS_BLOCK_GROUP_DUP; + } else { + /* they already had raid on here, just return */ + if (flags & stripped) + return flags; + + stripped |= BTRFS_BLOCK_GROUP_DUP; + stripped = flags & ~stripped; + + /* switch duplicated blocks with raid1 */ + if (flags & BTRFS_BLOCK_GROUP_DUP) + return stripped | BTRFS_BLOCK_GROUP_RAID1; + + /* this is drive concat, leave it alone */ + } + + return flags; +} + +static int set_block_group_ro(struct btrfs_block_group_cache *cache, int force) +{ + struct btrfs_space_info *sinfo = cache->space_info; + u64 num_bytes; + u64 min_allocable_bytes; + int ret = -ENOSPC; + + + /* + * We need some metadata space and system metadata space for + * allocating chunks in some corner cases until we force to set + * it to be readonly. + */ + if ((sinfo->flags & + (BTRFS_BLOCK_GROUP_SYSTEM | BTRFS_BLOCK_GROUP_METADATA)) && + !force) + min_allocable_bytes = 1 * 1024 * 1024; + else + min_allocable_bytes = 0; + + spin_lock(&sinfo->lock); + spin_lock(&cache->lock); + + if (cache->ro) { + ret = 0; + goto out; + } + + num_bytes = cache->key.offset - cache->reserved - cache->pinned - + cache->bytes_super - btrfs_block_group_used(&cache->item); + + if (sinfo->bytes_used + sinfo->bytes_reserved + sinfo->bytes_pinned + + sinfo->bytes_may_use + sinfo->bytes_readonly + num_bytes + + min_allocable_bytes <= sinfo->total_bytes) { + sinfo->bytes_readonly += num_bytes; + cache->ro = 1; + list_add_tail(&cache->ro_list, &sinfo->ro_bgs); + ret = 0; + } +out: + spin_unlock(&cache->lock); + spin_unlock(&sinfo->lock); + return ret; +} + +int btrfs_set_block_group_ro(struct btrfs_root *root, + struct btrfs_block_group_cache *cache) + +{ + struct btrfs_trans_handle *trans; + u64 alloc_flags; + int ret; + + BUG_ON(cache->ro); + +again: + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) + return PTR_ERR(trans); + + /* + * we're not allowed to set block groups readonly after the dirty + * block groups cache has started writing. If it already started, + * back off and let this transaction commit + */ + mutex_lock(&root->fs_info->ro_block_group_mutex); + if (trans->transaction->dirty_bg_run) { + u64 transid = trans->transid; + + mutex_unlock(&root->fs_info->ro_block_group_mutex); + btrfs_end_transaction(trans, root); + + ret = btrfs_wait_for_commit(root, transid); + if (ret) + return ret; + goto again; + } + + /* + * if we are changing raid levels, try to allocate a corresponding + * block group with the new raid level. + */ + alloc_flags = update_block_group_flags(root, cache->flags); + if (alloc_flags != cache->flags) { + ret = do_chunk_alloc(trans, root, alloc_flags, + CHUNK_ALLOC_FORCE); + /* + * ENOSPC is allowed here, we may have enough space + * already allocated at the new raid level to + * carry on + */ + if (ret == -ENOSPC) + ret = 0; + if (ret < 0) + goto out; + } + + ret = set_block_group_ro(cache, 0); + if (!ret) + goto out; + alloc_flags = get_alloc_profile(root, cache->space_info->flags); + ret = do_chunk_alloc(trans, root, alloc_flags, + CHUNK_ALLOC_FORCE); + if (ret < 0) + goto out; + ret = set_block_group_ro(cache, 0); +out: + if (cache->flags & BTRFS_BLOCK_GROUP_SYSTEM) { + alloc_flags = update_block_group_flags(root, cache->flags); + lock_chunks(root->fs_info->chunk_root); + check_system_chunk(trans, root, alloc_flags); + unlock_chunks(root->fs_info->chunk_root); + } + mutex_unlock(&root->fs_info->ro_block_group_mutex); + + btrfs_end_transaction(trans, root); + return ret; +} + +int btrfs_force_chunk_alloc(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 type) +{ + u64 alloc_flags = get_alloc_profile(root, type); + return do_chunk_alloc(trans, root, alloc_flags, + CHUNK_ALLOC_FORCE); +} + +/* + * helper to account the unused space of all the readonly block group in the + * space_info. takes mirrors into account. + */ +u64 btrfs_account_ro_block_groups_free_space(struct btrfs_space_info *sinfo) +{ + struct btrfs_block_group_cache *block_group; + u64 free_bytes = 0; + int factor; + + /* It's df, we don't care if it's racey */ + if (list_empty(&sinfo->ro_bgs)) + return 0; + + spin_lock(&sinfo->lock); + list_for_each_entry(block_group, &sinfo->ro_bgs, ro_list) { + spin_lock(&block_group->lock); + + if (!block_group->ro) { + spin_unlock(&block_group->lock); + continue; + } + + if (block_group->flags & (BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_DUP)) + factor = 2; + else + factor = 1; + + free_bytes += (block_group->key.offset - + btrfs_block_group_used(&block_group->item)) * + factor; + + spin_unlock(&block_group->lock); + } + spin_unlock(&sinfo->lock); + + return free_bytes; +} + +void btrfs_set_block_group_rw(struct btrfs_root *root, + struct btrfs_block_group_cache *cache) +{ + struct btrfs_space_info *sinfo = cache->space_info; + u64 num_bytes; + + BUG_ON(!cache->ro); + + spin_lock(&sinfo->lock); + spin_lock(&cache->lock); + num_bytes = cache->key.offset - cache->reserved - cache->pinned - + cache->bytes_super - btrfs_block_group_used(&cache->item); + sinfo->bytes_readonly -= num_bytes; + cache->ro = 0; + list_del_init(&cache->ro_list); + spin_unlock(&cache->lock); + spin_unlock(&sinfo->lock); +} + +/* + * 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; + struct btrfs_trans_handle *trans; + u64 min_free; + u64 dev_min = 1; + u64 dev_nr = 0; + u64 target; + int index; + 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; + + min_free = btrfs_block_group_used(&block_group->item); + + /* no bytes used, we're good */ + if (!min_free) + 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 + + min_free < 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. if this block + * group is going to be restriped, run checks against the target + * profile instead of the current one. + */ + ret = -1; + + /* + * index: + * 0: raid10 + * 1: raid1 + * 2: dup + * 3: raid0 + * 4: single + */ + target = get_restripe_target(root->fs_info, block_group->flags); + if (target) { + index = __get_raid_index(extended_to_chunk(target)); + } else { + /* + * this is just a balance, so if we were marked as full + * we know there is no space for a new chunk + */ + if (full) + goto out; + + index = get_block_group_index(block_group); + } + + if (index == BTRFS_RAID_RAID10) { + dev_min = 4; + /* Divide by 2 */ + min_free >>= 1; + } else if (index == BTRFS_RAID_RAID1) { + dev_min = 2; + } else if (index == BTRFS_RAID_DUP) { + /* Multiply by 2 */ + min_free <<= 1; + } else if (index == BTRFS_RAID_RAID0) { + dev_min = fs_devices->rw_devices; + min_free = div64_u64(min_free, dev_min); + } + + /* We need to do this so that we can look at pending chunks */ + trans = btrfs_join_transaction(root); + if (IS_ERR(trans)) { + ret = PTR_ERR(trans); + goto out; + } + + mutex_lock(&root->fs_info->chunk_mutex); + list_for_each_entry(device, &fs_devices->alloc_list, dev_alloc_list) { + u64 dev_offset; + + /* + * 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 && + !device->is_tgtdev_for_dev_replace) { + ret = find_free_dev_extent(trans, device, min_free, + &dev_offset, NULL); + if (!ret) + dev_nr++; + + if (dev_nr >= dev_min) + break; + + ret = -1; + } + } + mutex_unlock(&root->fs_info->chunk_mutex); + btrfs_end_transaction(trans, root); +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; +} + +void btrfs_put_block_group_cache(struct btrfs_fs_info *info) +{ + struct btrfs_block_group_cache *block_group; + u64 last = 0; + + while (1) { + struct inode *inode; + + block_group = btrfs_lookup_first_block_group(info, last); + while (block_group) { + spin_lock(&block_group->lock); + if (block_group->iref) + break; + spin_unlock(&block_group->lock); + block_group = next_block_group(info->tree_root, + block_group); + } + if (!block_group) { + if (last == 0) + break; + last = 0; + continue; + } + + inode = block_group->inode; + block_group->iref = 0; + block_group->inode = NULL; + spin_unlock(&block_group->lock); + iput(inode); + last = block_group->key.objectid + block_group->key.offset; + btrfs_put_block_group(block_group); + } +} + +int btrfs_free_block_groups(struct btrfs_fs_info *info) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_space_info *space_info; + struct btrfs_caching_control *caching_ctl; + struct rb_node *n; + + down_write(&info->commit_root_sem); + while (!list_empty(&info->caching_block_groups)) { + caching_ctl = list_entry(info->caching_block_groups.next, + struct btrfs_caching_control, list); + list_del(&caching_ctl->list); + put_caching_control(caching_ctl); + } + up_write(&info->commit_root_sem); + + spin_lock(&info->unused_bgs_lock); + while (!list_empty(&info->unused_bgs)) { + block_group = list_first_entry(&info->unused_bgs, + struct btrfs_block_group_cache, + bg_list); + list_del_init(&block_group->bg_list); + btrfs_put_block_group(block_group); + } + spin_unlock(&info->unused_bgs_lock); + + spin_lock(&info->block_group_cache_lock); + while ((n = rb_last(&info->block_group_cache_tree)) != NULL) { + block_group = rb_entry(n, struct btrfs_block_group_cache, + cache_node); + rb_erase(&block_group->cache_node, + &info->block_group_cache_tree); + RB_CLEAR_NODE(&block_group->cache_node); + spin_unlock(&info->block_group_cache_lock); + + down_write(&block_group->space_info->groups_sem); + list_del(&block_group->list); + up_write(&block_group->space_info->groups_sem); + + if (block_group->cached == BTRFS_CACHE_STARTED) + wait_block_group_cache_done(block_group); + + /* + * We haven't cached this block group, which means we could + * possibly have excluded extents on this block group. + */ + if (block_group->cached == BTRFS_CACHE_NO || + block_group->cached == BTRFS_CACHE_ERROR) + free_excluded_extents(info->extent_root, 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(); + + release_global_block_rsv(info); + + while (!list_empty(&info->space_info)) { + int i; + + space_info = list_entry(info->space_info.next, + struct btrfs_space_info, + list); + if (btrfs_test_opt(info->tree_root, ENOSPC_DEBUG)) { + if (WARN_ON(space_info->bytes_pinned > 0 || + space_info->bytes_reserved > 0 || + space_info->bytes_may_use > 0)) { + dump_space_info(space_info, 0, 0); + } + } + list_del(&space_info->list); + for (i = 0; i < BTRFS_NR_RAID_TYPES; i++) { + struct kobject *kobj; + kobj = space_info->block_group_kobjs[i]; + space_info->block_group_kobjs[i] = NULL; + if (kobj) { + kobject_del(kobj); + kobject_put(kobj); + } + } + kobject_del(&space_info->kobj); + kobject_put(&space_info->kobj); + } + return 0; +} + +static void __link_block_group(struct btrfs_space_info *space_info, + struct btrfs_block_group_cache *cache) +{ + int index = get_block_group_index(cache); + bool first = false; + + down_write(&space_info->groups_sem); + if (list_empty(&space_info->block_groups[index])) + first = true; + list_add_tail(&cache->list, &space_info->block_groups[index]); + up_write(&space_info->groups_sem); + + if (first) { + struct raid_kobject *rkobj; + int ret; + + rkobj = kzalloc(sizeof(*rkobj), GFP_NOFS); + if (!rkobj) + goto out_err; + rkobj->raid_type = index; + kobject_init(&rkobj->kobj, &btrfs_raid_ktype); + ret = kobject_add(&rkobj->kobj, &space_info->kobj, + "%s", get_raid_name(index)); + if (ret) { + kobject_put(&rkobj->kobj); + goto out_err; + } + space_info->block_group_kobjs[index] = &rkobj->kobj; + } + + return; +out_err: + pr_warn("BTRFS: failed to add kobject for block cache. ignoring.\n"); +} + +static struct btrfs_block_group_cache * +btrfs_create_block_group_cache(struct btrfs_root *root, u64 start, u64 size) +{ + struct btrfs_block_group_cache *cache; + + cache = kzalloc(sizeof(*cache), GFP_NOFS); + if (!cache) + return NULL; + + cache->free_space_ctl = kzalloc(sizeof(*cache->free_space_ctl), + GFP_NOFS); + if (!cache->free_space_ctl) { + kfree(cache); + return NULL; + } + + cache->key.objectid = start; + cache->key.offset = size; + cache->key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; + + cache->sectorsize = root->sectorsize; + cache->fs_info = root->fs_info; + cache->full_stripe_len = btrfs_full_stripe_len(root, + &root->fs_info->mapping_tree, + start); + atomic_set(&cache->count, 1); + spin_lock_init(&cache->lock); + init_rwsem(&cache->data_rwsem); + INIT_LIST_HEAD(&cache->list); + INIT_LIST_HEAD(&cache->cluster_list); + INIT_LIST_HEAD(&cache->bg_list); + INIT_LIST_HEAD(&cache->ro_list); + INIT_LIST_HEAD(&cache->dirty_list); + INIT_LIST_HEAD(&cache->io_list); + btrfs_init_free_space_ctl(cache); + atomic_set(&cache->trimming, 0); + + return cache; +} + +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; + int need_clear = 0; + u64 cache_gen; + + root = info->extent_root; + key.objectid = 0; + key.offset = 0; + key.type = BTRFS_BLOCK_GROUP_ITEM_KEY; + path = btrfs_alloc_path(); + if (!path) + return -ENOMEM; + path->reada = 1; + + cache_gen = btrfs_super_cache_generation(root->fs_info->super_copy); + if (btrfs_test_opt(root, SPACE_CACHE) && + btrfs_super_generation(root->fs_info->super_copy) != cache_gen) + need_clear = 1; + if (btrfs_test_opt(root, CLEAR_CACHE)) + need_clear = 1; + + while (1) { + ret = find_first_block_group(root, path, &key); + if (ret > 0) + break; + if (ret != 0) + goto error; + + leaf = path->nodes[0]; + btrfs_item_key_to_cpu(leaf, &found_key, path->slots[0]); + + cache = btrfs_create_block_group_cache(root, found_key.objectid, + found_key.offset); + if (!cache) { + ret = -ENOMEM; + goto error; + } + + if (need_clear) { + /* + * When we mount with old space cache, we need to + * set BTRFS_DC_CLEAR and set dirty flag. + * + * a) Setting 'BTRFS_DC_CLEAR' makes sure that we + * truncate the old free space cache inode and + * setup a new one. + * b) Setting 'dirty flag' makes sure that we flush + * the new space cache info onto disk. + */ + if (btrfs_test_opt(root, SPACE_CACHE)) + cache->disk_cache_state = BTRFS_DC_CLEAR; + } + + read_extent_buffer(leaf, &cache->item, + btrfs_item_ptr_offset(leaf, path->slots[0]), + sizeof(cache->item)); + cache->flags = btrfs_block_group_flags(&cache->item); + + key.objectid = found_key.objectid + found_key.offset; + btrfs_release_path(path); + + /* + * We need to exclude the super stripes now so that the space + * info has super bytes accounted for, otherwise we'll think + * we have more space than we actually do. + */ + ret = exclude_super_stripes(root, cache); + if (ret) { + /* + * We may have excluded something, so call this just in + * case. + */ + free_excluded_extents(root, cache); + btrfs_put_block_group(cache); + goto error; + } + + /* + * check for two cases, either we are full, and therefore + * don't need to bother with the caching work since we won't + * find any space, or we are empty, and we can just add all + * the space in and be done with it. This saves us _alot_ of + * time, particularly in the full case. + */ + if (found_key.offset == btrfs_block_group_used(&cache->item)) { + cache->last_byte_to_unpin = (u64)-1; + cache->cached = BTRFS_CACHE_FINISHED; + free_excluded_extents(root, cache); + } else if (btrfs_block_group_used(&cache->item) == 0) { + cache->last_byte_to_unpin = (u64)-1; + cache->cached = BTRFS_CACHE_FINISHED; + add_new_free_space(cache, root->fs_info, + found_key.objectid, + found_key.objectid + + found_key.offset); + free_excluded_extents(root, cache); + } + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + if (ret) { + btrfs_remove_free_space_cache(cache); + btrfs_put_block_group(cache); + goto error; + } + + ret = update_space_info(info, cache->flags, found_key.offset, + btrfs_block_group_used(&cache->item), + &space_info); + if (ret) { + btrfs_remove_free_space_cache(cache); + spin_lock(&info->block_group_cache_lock); + rb_erase(&cache->cache_node, + &info->block_group_cache_tree); + RB_CLEAR_NODE(&cache->cache_node); + spin_unlock(&info->block_group_cache_lock); + btrfs_put_block_group(cache); + goto error; + } + + cache->space_info = space_info; + spin_lock(&cache->space_info->lock); + cache->space_info->bytes_readonly += cache->bytes_super; + spin_unlock(&cache->space_info->lock); + + __link_block_group(space_info, cache); + + set_avail_alloc_bits(root->fs_info, cache->flags); + if (btrfs_chunk_readonly(root, cache->key.objectid)) { + set_block_group_ro(cache, 1); + } else if (btrfs_block_group_used(&cache->item) == 0) { + spin_lock(&info->unused_bgs_lock); + /* Should always be true but just in case. */ + if (list_empty(&cache->bg_list)) { + btrfs_get_block_group(cache); + list_add_tail(&cache->bg_list, + &info->unused_bgs); + } + spin_unlock(&info->unused_bgs_lock); + } + } + + list_for_each_entry_rcu(space_info, &root->fs_info->space_info, list) { + if (!(get_alloc_profile(root, space_info->flags) & + (BTRFS_BLOCK_GROUP_RAID10 | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID5 | + BTRFS_BLOCK_GROUP_RAID6 | + BTRFS_BLOCK_GROUP_DUP))) + continue; + /* + * avoid allocating from un-mirrored block group if there are + * mirrored block groups. + */ + list_for_each_entry(cache, + &space_info->block_groups[BTRFS_RAID_RAID0], + list) + set_block_group_ro(cache, 1); + list_for_each_entry(cache, + &space_info->block_groups[BTRFS_RAID_SINGLE], + list) + set_block_group_ro(cache, 1); + } + + init_global_block_rsv(info); + ret = 0; +error: + btrfs_free_path(path); + return ret; +} + +void btrfs_create_pending_block_groups(struct btrfs_trans_handle *trans, + struct btrfs_root *root) +{ + struct btrfs_block_group_cache *block_group, *tmp; + struct btrfs_root *extent_root = root->fs_info->extent_root; + struct btrfs_block_group_item item; + struct btrfs_key key; + int ret = 0; + + list_for_each_entry_safe(block_group, tmp, &trans->new_bgs, bg_list) { + if (ret) + goto next; + + spin_lock(&block_group->lock); + memcpy(&item, &block_group->item, sizeof(item)); + memcpy(&key, &block_group->key, sizeof(key)); + spin_unlock(&block_group->lock); + + ret = btrfs_insert_item(trans, extent_root, &key, &item, + sizeof(item)); + if (ret) + btrfs_abort_transaction(trans, extent_root, ret); + ret = btrfs_finish_chunk_alloc(trans, extent_root, + key.objectid, key.offset); + if (ret) + btrfs_abort_transaction(trans, extent_root, ret); +next: + list_del_init(&block_group->bg_list); + } +} + +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; + + btrfs_set_log_full_commit(root->fs_info, trans); + + cache = btrfs_create_block_group_cache(root, chunk_offset, size); + if (!cache) + return -ENOMEM; + + btrfs_set_block_group_used(&cache->item, bytes_used); + btrfs_set_block_group_chunk_objectid(&cache->item, chunk_objectid); + btrfs_set_block_group_flags(&cache->item, type); + + cache->flags = type; + cache->last_byte_to_unpin = (u64)-1; + cache->cached = BTRFS_CACHE_FINISHED; + ret = exclude_super_stripes(root, cache); + if (ret) { + /* + * We may have excluded something, so call this just in + * case. + */ + free_excluded_extents(root, cache); + btrfs_put_block_group(cache); + return ret; + } + + add_new_free_space(cache, root->fs_info, chunk_offset, + chunk_offset + size); + + free_excluded_extents(root, cache); + + ret = btrfs_add_block_group_cache(root->fs_info, cache); + if (ret) { + btrfs_remove_free_space_cache(cache); + btrfs_put_block_group(cache); + return ret; + } + + ret = update_space_info(root->fs_info, cache->flags, size, bytes_used, + &cache->space_info); + if (ret) { + btrfs_remove_free_space_cache(cache); + spin_lock(&root->fs_info->block_group_cache_lock); + rb_erase(&cache->cache_node, + &root->fs_info->block_group_cache_tree); + RB_CLEAR_NODE(&cache->cache_node); + spin_unlock(&root->fs_info->block_group_cache_lock); + btrfs_put_block_group(cache); + return ret; + } + update_global_block_rsv(root->fs_info); + + spin_lock(&cache->space_info->lock); + cache->space_info->bytes_readonly += cache->bytes_super; + spin_unlock(&cache->space_info->lock); + + __link_block_group(cache->space_info, cache); + + list_add_tail(&cache->bg_list, &trans->new_bgs); + + set_avail_alloc_bits(extent_root->fs_info, type); + + return 0; +} + +static void clear_avail_alloc_bits(struct btrfs_fs_info *fs_info, u64 flags) +{ + u64 extra_flags = chunk_to_extended(flags) & + BTRFS_EXTENDED_PROFILE_MASK; + + write_seqlock(&fs_info->profiles_lock); + if (flags & BTRFS_BLOCK_GROUP_DATA) + fs_info->avail_data_alloc_bits &= ~extra_flags; + if (flags & BTRFS_BLOCK_GROUP_METADATA) + fs_info->avail_metadata_alloc_bits &= ~extra_flags; + if (flags & BTRFS_BLOCK_GROUP_SYSTEM) + fs_info->avail_system_alloc_bits &= ~extra_flags; + write_sequnlock(&fs_info->profiles_lock); +} + +int btrfs_remove_block_group(struct btrfs_trans_handle *trans, + struct btrfs_root *root, u64 group_start, + struct extent_map *em) +{ + struct btrfs_path *path; + struct btrfs_block_group_cache *block_group; + struct btrfs_free_cluster *cluster; + struct btrfs_root *tree_root = root->fs_info->tree_root; + struct btrfs_key key; + struct inode *inode; + struct kobject *kobj = NULL; + int ret; + int index; + int factor; + struct btrfs_caching_control *caching_ctl = NULL; + bool remove_em; + + 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); + + /* + * Free the reserved super bytes from this block group before + * remove it. + */ + free_excluded_extents(root, block_group); + + memcpy(&key, &block_group->key, sizeof(key)); + index = get_block_group_index(block_group); + if (block_group->flags & (BTRFS_BLOCK_GROUP_DUP | + BTRFS_BLOCK_GROUP_RAID1 | + BTRFS_BLOCK_GROUP_RAID10)) + factor = 2; + else + factor = 1; + + /* 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(); + if (!path) { + ret = -ENOMEM; + goto out; + } + + /* + * get the inode first so any iput calls done for the io_list + * aren't the final iput (no unlinks allowed now) + */ + inode = lookup_free_space_inode(tree_root, block_group, path); + + mutex_lock(&trans->transaction->cache_write_mutex); + /* + * make sure our free spache cache IO is done before remove the + * free space inode + */ + spin_lock(&trans->transaction->dirty_bgs_lock); + if (!list_empty(&block_group->io_list)) { + list_del_init(&block_group->io_list); + + WARN_ON(!IS_ERR(inode) && inode != block_group->io_ctl.inode); + + spin_unlock(&trans->transaction->dirty_bgs_lock); + btrfs_wait_cache_io(root, trans, block_group, + &block_group->io_ctl, path, + block_group->key.objectid); + btrfs_put_block_group(block_group); + spin_lock(&trans->transaction->dirty_bgs_lock); + } + + if (!list_empty(&block_group->dirty_list)) { + list_del_init(&block_group->dirty_list); + btrfs_put_block_group(block_group); + } + spin_unlock(&trans->transaction->dirty_bgs_lock); + mutex_unlock(&trans->transaction->cache_write_mutex); + + if (!IS_ERR(inode)) { + ret = btrfs_orphan_add(trans, inode); + if (ret) { + btrfs_add_delayed_iput(inode); + goto out; + } + clear_nlink(inode); + /* One for the block groups ref */ + spin_lock(&block_group->lock); + if (block_group->iref) { + block_group->iref = 0; + block_group->inode = NULL; + spin_unlock(&block_group->lock); + iput(inode); + } else { + spin_unlock(&block_group->lock); + } + /* One for our lookup ref */ + btrfs_add_delayed_iput(inode); + } + + key.objectid = BTRFS_FREE_SPACE_OBJECTID; + key.offset = block_group->key.objectid; + key.type = 0; + + ret = btrfs_search_slot(trans, tree_root, &key, path, -1, 1); + if (ret < 0) + goto out; + if (ret > 0) + btrfs_release_path(path); + if (ret == 0) { + ret = btrfs_del_item(trans, tree_root, path); + if (ret) + goto out; + btrfs_release_path(path); + } + + spin_lock(&root->fs_info->block_group_cache_lock); + rb_erase(&block_group->cache_node, + &root->fs_info->block_group_cache_tree); + RB_CLEAR_NODE(&block_group->cache_node); + + if (root->fs_info->first_logical_byte == block_group->key.objectid) + root->fs_info->first_logical_byte = (u64)-1; + 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); + if (list_empty(&block_group->space_info->block_groups[index])) { + kobj = block_group->space_info->block_group_kobjs[index]; + block_group->space_info->block_group_kobjs[index] = NULL; + clear_avail_alloc_bits(root->fs_info, block_group->flags); + } + up_write(&block_group->space_info->groups_sem); + if (kobj) { + kobject_del(kobj); + kobject_put(kobj); + } + + if (block_group->has_caching_ctl) + caching_ctl = get_caching_control(block_group); + if (block_group->cached == BTRFS_CACHE_STARTED) + wait_block_group_cache_done(block_group); + if (block_group->has_caching_ctl) { + down_write(&root->fs_info->commit_root_sem); + if (!caching_ctl) { + struct btrfs_caching_control *ctl; + + list_for_each_entry(ctl, + &root->fs_info->caching_block_groups, list) + if (ctl->block_group == block_group) { + caching_ctl = ctl; + atomic_inc(&caching_ctl->count); + break; + } + } + if (caching_ctl) + list_del_init(&caching_ctl->list); + up_write(&root->fs_info->commit_root_sem); + if (caching_ctl) { + /* Once for the caching bgs list and once for us. */ + put_caching_control(caching_ctl); + put_caching_control(caching_ctl); + } + } + + spin_lock(&trans->transaction->dirty_bgs_lock); + if (!list_empty(&block_group->dirty_list)) { + WARN_ON(1); + } + if (!list_empty(&block_group->io_list)) { + WARN_ON(1); + } + spin_unlock(&trans->transaction->dirty_bgs_lock); + btrfs_remove_free_space_cache(block_group); + + spin_lock(&block_group->space_info->lock); + list_del_init(&block_group->ro_list); + + if (btrfs_test_opt(root, ENOSPC_DEBUG)) { + WARN_ON(block_group->space_info->total_bytes + < block_group->key.offset); + WARN_ON(block_group->space_info->bytes_readonly + < block_group->key.offset); + WARN_ON(block_group->space_info->disk_total + < block_group->key.offset * factor); + } + block_group->space_info->total_bytes -= block_group->key.offset; + block_group->space_info->bytes_readonly -= block_group->key.offset; + block_group->space_info->disk_total -= block_group->key.offset * factor; + + spin_unlock(&block_group->space_info->lock); + + memcpy(&key, &block_group->key, sizeof(key)); + + lock_chunks(root); + if (!list_empty(&em->list)) { + /* We're in the transaction->pending_chunks list. */ + free_extent_map(em); + } + spin_lock(&block_group->lock); + block_group->removed = 1; + /* + * At this point trimming can't start on this block group, because we + * removed the block group from the tree fs_info->block_group_cache_tree + * so no one can't find it anymore and even if someone already got this + * block group before we removed it from the rbtree, they have already + * incremented block_group->trimming - if they didn't, they won't find + * any free space entries because we already removed them all when we + * called btrfs_remove_free_space_cache(). + * + * And we must not remove the extent map from the fs_info->mapping_tree + * to prevent the same logical address range and physical device space + * ranges from being reused for a new block group. This is because our + * fs trim operation (btrfs_trim_fs() / btrfs_ioctl_fitrim()) is + * completely transactionless, so while it is trimming a range the + * currently running transaction might finish and a new one start, + * allowing for new block groups to be created that can reuse the same + * physical device locations unless we take this special care. + */ + remove_em = (atomic_read(&block_group->trimming) == 0); + /* + * Make sure a trimmer task always sees the em in the pinned_chunks list + * if it sees block_group->removed == 1 (needs to lock block_group->lock + * before checking block_group->removed). + */ + if (!remove_em) { + /* + * Our em might be in trans->transaction->pending_chunks which + * is protected by fs_info->chunk_mutex ([lock|unlock]_chunks), + * and so is the fs_info->pinned_chunks list. + * + * So at this point we must be holding the chunk_mutex to avoid + * any races with chunk allocation (more specifically at + * volumes.c:contains_pending_extent()), to ensure it always + * sees the em, either in the pending_chunks list or in the + * pinned_chunks list. + */ + list_move_tail(&em->list, &root->fs_info->pinned_chunks); + } + spin_unlock(&block_group->lock); + + if (remove_em) { + struct extent_map_tree *em_tree; + + em_tree = &root->fs_info->mapping_tree.map_tree; + write_lock(&em_tree->lock); + /* + * The em might be in the pending_chunks list, so make sure the + * chunk mutex is locked, since remove_extent_mapping() will + * delete us from that list. + */ + remove_extent_mapping(em_tree, em); + write_unlock(&em_tree->lock); + /* once for the tree */ + free_extent_map(em); + } + + unlock_chunks(root); + + 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; +} + +/* + * Process the unused_bgs list and remove any that don't have any allocated + * space inside of them. + */ +void btrfs_delete_unused_bgs(struct btrfs_fs_info *fs_info) +{ + struct btrfs_block_group_cache *block_group; + struct btrfs_space_info *space_info; + struct btrfs_root *root = fs_info->extent_root; + struct btrfs_trans_handle *trans; + int ret = 0; + + if (!fs_info->open) + return; + + spin_lock(&fs_info->unused_bgs_lock); + while (!list_empty(&fs_info->unused_bgs)) { + u64 start, end; + + block_group = list_first_entry(&fs_info->unused_bgs, + struct btrfs_block_group_cache, + bg_list); + space_info = block_group->space_info; + list_del_init(&block_group->bg_list); + if (ret || btrfs_mixed_space_info(space_info)) { + btrfs_put_block_group(block_group); + continue; + } + spin_unlock(&fs_info->unused_bgs_lock); + + /* Don't want to race with allocators so take the groups_sem */ + down_write(&space_info->groups_sem); + spin_lock(&block_group->lock); + if (block_group->reserved || + btrfs_block_group_used(&block_group->item) || + block_group->ro) { + /* + * We want to bail if we made new allocations or have + * outstanding allocations in this block group. We do + * the ro check in case balance is currently acting on + * this block group. + */ + spin_unlock(&block_group->lock); + up_write(&space_info->groups_sem); + goto next; + } + spin_unlock(&block_group->lock); + + /* We don't want to force the issue, only flip if it's ok. */ + ret = set_block_group_ro(block_group, 0); + up_write(&space_info->groups_sem); + if (ret < 0) { + ret = 0; + goto next; + } + + /* + * Want to do this before we do anything else so we can recover + * properly if we fail to join the transaction. + */ + /* 1 for btrfs_orphan_reserve_metadata() */ + trans = btrfs_start_transaction(root, 1); + if (IS_ERR(trans)) { + btrfs_set_block_group_rw(root, block_group); + ret = PTR_ERR(trans); + goto next; + } + + /* + * We could have pending pinned extents for this block group, + * just delete them, we don't care about them anymore. + */ + start = block_group->key.objectid; + end = start + block_group->key.offset - 1; + /* + * Hold the unused_bg_unpin_mutex lock to avoid racing with + * btrfs_finish_extent_commit(). If we are at transaction N, + * another task might be running finish_extent_commit() for the + * previous transaction N - 1, and have seen a range belonging + * to the block group in freed_extents[] before we were able to + * clear the whole block group range from freed_extents[]. This + * means that task can lookup for the block group after we + * unpinned it from freed_extents[] and removed it, leading to + * a BUG_ON() at btrfs_unpin_extent_range(). + */ + mutex_lock(&fs_info->unused_bg_unpin_mutex); + ret = clear_extent_bits(&fs_info->freed_extents[0], start, end, + EXTENT_DIRTY, GFP_NOFS); + if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); + btrfs_set_block_group_rw(root, block_group); + goto end_trans; + } + ret = clear_extent_bits(&fs_info->freed_extents[1], start, end, + EXTENT_DIRTY, GFP_NOFS); + if (ret) { + mutex_unlock(&fs_info->unused_bg_unpin_mutex); + btrfs_set_block_group_rw(root, block_group); + goto end_trans; + } + mutex_unlock(&fs_info->unused_bg_unpin_mutex); + + /* Reset pinned so btrfs_put_block_group doesn't complain */ + spin_lock(&space_info->lock); + spin_lock(&block_group->lock); + + space_info->bytes_pinned -= block_group->pinned; + space_info->bytes_readonly += block_group->pinned; + percpu_counter_add(&space_info->total_bytes_pinned, + -block_group->pinned); + block_group->pinned = 0; + + spin_unlock(&block_group->lock); + spin_unlock(&space_info->lock); + + /* + * Btrfs_remove_chunk will abort the transaction if things go + * horribly wrong. + */ + ret = btrfs_remove_chunk(trans, root, + block_group->key.objectid); +end_trans: + btrfs_end_transaction(trans, root); +next: + btrfs_put_block_group(block_group); + spin_lock(&fs_info->unused_bgs_lock); + } + spin_unlock(&fs_info->unused_bgs_lock); +} + +int btrfs_init_space_info(struct btrfs_fs_info *fs_info) +{ + struct btrfs_space_info *space_info; + struct btrfs_super_block *disk_super; + u64 features; + u64 flags; + int mixed = 0; + int ret; + + disk_super = fs_info->super_copy; + if (!btrfs_super_root(disk_super)) + return 1; + + features = btrfs_super_incompat_flags(disk_super); + if (features & BTRFS_FEATURE_INCOMPAT_MIXED_GROUPS) + mixed = 1; + + flags = BTRFS_BLOCK_GROUP_SYSTEM; + ret = update_space_info(fs_info, flags, 0, 0, &space_info); + if (ret) + goto out; + + if (mixed) { + flags = BTRFS_BLOCK_GROUP_METADATA | BTRFS_BLOCK_GROUP_DATA; + ret = update_space_info(fs_info, flags, 0, 0, &space_info); + } else { + flags = BTRFS_BLOCK_GROUP_METADATA; + ret = update_space_info(fs_info, flags, 0, 0, &space_info); + if (ret) + goto out; + + flags = BTRFS_BLOCK_GROUP_DATA; + ret = update_space_info(fs_info, flags, 0, 0, &space_info); + } +out: + return ret; +} + +int btrfs_error_unpin_extent_range(struct btrfs_root *root, u64 start, u64 end) +{ + return unpin_extent_range(root, start, end, false); +} + +int btrfs_trim_fs(struct btrfs_root *root, struct fstrim_range *range) +{ + struct btrfs_fs_info *fs_info = root->fs_info; + struct btrfs_block_group_cache *cache = NULL; + u64 group_trimmed; + u64 start; + u64 end; + u64 trimmed = 0; + u64 total_bytes = btrfs_super_total_bytes(fs_info->super_copy); + int ret = 0; + + /* + * try to trim all FS space, our block group may start from non-zero. + */ + if (range->len == total_bytes) + cache = btrfs_lookup_first_block_group(fs_info, range->start); + else + cache = btrfs_lookup_block_group(fs_info, range->start); + + while (cache) { + if (cache->key.objectid >= (range->start + range->len)) { + btrfs_put_block_group(cache); + break; + } + + start = max(range->start, cache->key.objectid); + end = min(range->start + range->len, + cache->key.objectid + cache->key.offset); + + if (end - start >= range->minlen) { + if (!block_group_cache_done(cache)) { + ret = cache_block_group(cache, 0); + if (ret) { + btrfs_put_block_group(cache); + break; + } + ret = wait_block_group_cache_done(cache); + if (ret) { + btrfs_put_block_group(cache); + break; + } + } + ret = btrfs_trim_block_group(cache, + &group_trimmed, + start, + end, + range->minlen); + + trimmed += group_trimmed; + if (ret) { + btrfs_put_block_group(cache); + break; + } + } + + cache = next_block_group(fs_info->tree_root, cache); + } + + range->len = trimmed; + return ret; +} + +/* + * btrfs_{start,end}_write_no_snapshoting() are similar to + * mnt_{want,drop}_write(), they are used to prevent some tasks from writing + * data into the page cache through nocow before the subvolume is snapshoted, + * but flush the data into disk after the snapshot creation, or to prevent + * operations while snapshoting is ongoing and that cause the snapshot to be + * inconsistent (writes followed by expanding truncates for example). + */ +void btrfs_end_write_no_snapshoting(struct btrfs_root *root) +{ + percpu_counter_dec(&root->subv_writers->counter); + /* + * Make sure counter is updated before we wake up + * waiters. + */ + smp_mb(); + if (waitqueue_active(&root->subv_writers->wait)) + wake_up(&root->subv_writers->wait); +} + +int btrfs_start_write_no_snapshoting(struct btrfs_root *root) +{ + if (atomic_read(&root->will_be_snapshoted)) + return 0; + + percpu_counter_inc(&root->subv_writers->counter); + /* + * Make sure counter is updated before we check for snapshot creation. + */ + smp_mb(); + if (atomic_read(&root->will_be_snapshoted)) { + btrfs_end_write_no_snapshoting(root); + return 0; + } + return 1; +} |