diff options
| author | Josef Bacik <josef@redhat.com> | 2010-12-08 09:15:11 -0500 |
|---|---|---|
| committer | Josef Bacik <josef@redhat.com> | 2010-12-09 13:57:13 -0500 |
| commit | b8399dee478db7939cd0d6fda8ecacddf2facd03 (patch) | |
| tree | 418a67d8d2de13739f3b14518917c8aaadafe3b8 /fs | |
| parent | 2b20982e3154266106573beac2a4d4ba57a2789a (diff) | |
| download | linux-b8399dee478db7939cd0d6fda8ecacddf2facd03.tar.gz | |
Btrfs: do not do fast caching if we are allocating blocks for tree_root
Since the fast caching uses normal tree locking, we can possibly deadlock if we get to the caching via a btrfs_search_slot() on the tree_root. So just check to see if the root we are on is the tree root, and just don't do the fast caching. Reported-by: Sage Weil <sage@newdream.net> Signed-off-by: Josef Bacik <josef@redhat.com>
Diffstat (limited to 'fs')
| -rw-r--r-- | fs/btrfs/extent-tree.c | 18 |
1 files changed, 12 insertions, 6 deletions
diff --git a/fs/btrfs/extent-tree.c b/fs/btrfs/extent-tree.c index 8c56f5b38948..cec05e100142 100644 --- a/fs/btrfs/extent-tree.c +++ b/fs/btrfs/extent-tree.c @@ -429,6 +429,7 @@ err: static int cache_block_group(struct btrfs_block_group_cache *cache, struct btrfs_trans_handle *trans, + struct btrfs_root *root, int load_cache_only) { struct btrfs_fs_info *fs_info = cache->fs_info; @@ -442,9 +443,12 @@ static int cache_block_group(struct btrfs_block_group_cache *cache, /* * We can't do the read from on-disk cache during a commit since we need - * to have the normal tree locking. + * to have the normal tree locking. Also if we are currently trying to + * allocate blocks for the tree root we can't do the fast caching since + * we likely hold important locks. */ - if (!trans->transaction->in_commit) { + if (!trans->transaction->in_commit && + (root && root != root->fs_info->tree_root)) { spin_lock(&cache->lock); if (cache->cached != BTRFS_CACHE_NO) { spin_unlock(&cache->lock); @@ -4083,7 +4087,7 @@ static int update_block_group(struct btrfs_trans_handle *trans, * space back to the block group, otherwise we will leak space. */ if (!alloc && cache->cached == BTRFS_CACHE_NO) - cache_block_group(cache, trans, 1); + cache_block_group(cache, trans, NULL, 1); byte_in_group = bytenr - cache->key.objectid; WARN_ON(byte_in_group > cache->key.offset); @@ -4937,7 +4941,8 @@ have_block_group: if (unlikely(block_group->cached == BTRFS_CACHE_NO)) { u64 free_percent; - ret = cache_block_group(block_group, trans, 1); + ret = cache_block_group(block_group, trans, + orig_root, 1); if (block_group->cached == BTRFS_CACHE_FINISHED) goto have_block_group; @@ -4961,7 +4966,8 @@ have_block_group: if (loop > LOOP_CACHING_NOWAIT || (loop > LOOP_FIND_IDEAL && atomic_read(&space_info->caching_threads) < 2)) { - ret = cache_block_group(block_group, trans, 0); + ret = cache_block_group(block_group, trans, + orig_root, 0); BUG_ON(ret); } found_uncached_bg = true; @@ -5518,7 +5524,7 @@ int btrfs_alloc_logged_file_extent(struct btrfs_trans_handle *trans, u64 num_bytes = ins->offset; block_group = btrfs_lookup_block_group(root->fs_info, ins->objectid); - cache_block_group(block_group, trans, 0); + cache_block_group(block_group, trans, NULL, 0); caching_ctl = get_caching_control(block_group); if (!caching_ctl) { |