[PATCH 5.10.y 1/5] btrfs: have proper error handling in btrfs_init_reloc_root

[Sasha Levin <sashal@kernel.org>]

From: Josef Bacik <josef@toxicpanda.com>

[ Upstream commit 00bb36a0e76ab7e94bdd70d561baf25f9bc1415d ]

create_reloc_root will return errors in the future, and __add_reloc_root
can return ENOMEM or EEXIST, so handle these errors properly.

Signed-off-by: Josef Bacik <josef@toxicpanda.com>
Reviewed-by: David Sterba <dsterba@suse.com>
[ add comment ]
Signed-off-by: David Sterba <dsterba@suse.com>
Stable-dep-of: 6d8ba4572922 ("btrfs: drop recovered reloc root refs on recovery failure")
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 fs/btrfs/relocation.c | 8 +++++++-
 1 file changed, 7 insertions(+), 1 deletion(-)

diff --git a/fs/btrfs/relocation.c b/fs/btrfs/relocation.c
index 5b921e6ed94e2..b0d34879e267f 100644
--- a/fs/btrfs/relocation.c
+++ b/fs/btrfs/relocation.c
@@ -878,9 +878,15 @@ int btrfs_init_reloc_root(struct btrfs_trans_handle *trans,
 	reloc_root = create_reloc_root(trans, root, root->root_key.objectid);
 	if (clear_rsv)
 		trans->block_rsv = rsv;
+	if (IS_ERR(reloc_root))
+		return PTR_ERR(reloc_root);
 
 	ret = __add_reloc_root(reloc_root);
-	BUG_ON(ret < 0);
+	if (ret) {
+		/* Pairs with create_reloc_root */
+		btrfs_put_root(reloc_root);
+		return ret;
+	}
 	root->reloc_root = btrfs_grab_root(reloc_root);
 	return 0;
 }
-- 
2.53.0