[PATCH 1/2] btrfs: free fs roots on failed mount

[Josef Bacik <josef@toxicpanda.com>]

While testing a weird problem with -o degraded, I noticed I was getting
leaked root errors

BTRFS warning (device loop0): writable mount is not allowed due to too many missing devices
BTRFS error (device loop0): open_ctree failed
BTRFS error (device loop0): leaked root -9-0 refcount 1

This is the DATA_RELOC root, which gets read before the other fs roots,
but is included in the fs roots radix tree, and thus gets freed by
btrfs_free_fs_roots.  Fix this by moving the call into fail_tree_roots:
in open_ctree.  With this fix we no longer leak that root on mount
failure.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
---
 fs/btrfs/disk-io.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/fs/btrfs/disk-io.c b/fs/btrfs/disk-io.c
index c850d7f44fbe..f1fdbdd44c02 100644
--- a/fs/btrfs/disk-io.c
+++ b/fs/btrfs/disk-io.c
@@ -3421,7 +3421,6 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 fail_trans_kthread:
 	kthread_stop(fs_info->transaction_kthread);
 	btrfs_cleanup_transaction(fs_info);
-	btrfs_free_fs_roots(fs_info);
 fail_cleaner:
 	kthread_stop(fs_info->cleaner_kthread);
 
@@ -3441,6 +3440,7 @@ int __cold open_ctree(struct super_block *sb, struct btrfs_fs_devices *fs_device
 	btrfs_put_block_group_cache(fs_info);
 
 fail_tree_roots:
+	btrfs_free_fs_roots(fs_info);
 	free_root_pointers(fs_info, true);
 	invalidate_inode_pages2(fs_info->btree_inode->i_mapping);
 
-- 
2.24.1