Btrfs: Fix snapshot deletion to release the alloc_mutex much more often.
This lowers the impact of snapshot deletion on the rest of the FS.
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/ctree.c b/fs/btrfs/ctree.c
index fd68601..5edbcc0 100644
--- a/fs/btrfs/ctree.c
+++ b/fs/btrfs/ctree.c
@@ -1255,7 +1255,7 @@
lowest_level = p->lowest_level;
WARN_ON(lowest_level && ins_len);
WARN_ON(p->nodes[0] != NULL);
- WARN_ON(root == root->fs_info->extent_root &&
+ WARN_ON(cow && root == root->fs_info->extent_root &&
!mutex_is_locked(&root->fs_info->alloc_mutex));
WARN_ON(root == root->fs_info->chunk_root &&
!mutex_is_locked(&root->fs_info->chunk_mutex));
