btrfs: fix unlocked access of delalloc_inodes
list_splice_init will make delalloc_inodes empty, but without a spinlock
around, this may produce corrupted list head, accessed in many placess,
The race window is very tight and nobody seems to have hit it so far.
Signed-off-by: David Sterba <dsterba@suse.cz>
Signed-off-by: Chris Mason <chris.mason@oracle.com>
diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index a203d36..33b744a 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -2911,9 +2911,8 @@
INIT_LIST_HEAD(&splice);
- list_splice_init(&root->fs_info->delalloc_inodes, &splice);
-
spin_lock(&root->fs_info->delalloc_lock);
+ list_splice_init(&root->fs_info->delalloc_inodes, &splice);
while (!list_empty(&splice)) {
btrfs_inode = list_entry(splice.next, struct btrfs_inode,