[PATCH AUTOSEL 5.0 051/317] btrfs: Don't panic when we can't find a root key

[Sasha Levin]

From: Qu Wenruo <w...@suse.com>

[ Upstream commit 7ac1e464c4d473b517bb784f30d40da1f842482e ]

When we failed to find a root key in btrfs_update_root(), we just panic.

That's definitely not cool, fix it by outputting an unique error
message, aborting current transaction and return -EUCLEAN. This should
not normally happen as the root has been used by the callers in some
way.

Reviewed-by: Filipe Manana <fdman...@suse.com>
Reviewed-by: Johannes Thumshirn <jthumsh...@suse.de>
Signed-off-by: Qu Wenruo <w...@suse.com>
Reviewed-by: David Sterba <dste...@suse.com>
Signed-off-by: David Sterba <dste...@suse.com>
Signed-off-by: Sasha Levin <sas...@kernel.org>
---
 fs/btrfs/root-tree.c | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/fs/btrfs/root-tree.c b/fs/btrfs/root-tree.c
index 65bda0682928b..f51a4a425a457 100644
--- a/fs/btrfs/root-tree.c
+++ b/fs/btrfs/root-tree.c
@@ -137,11 +137,14 @@ int btrfs_update_root(struct btrfs_trans_handle *trans, 
struct btrfs_root
                goto out;
        }
 
-       if (ret != 0) {
-               btrfs_print_leaf(path->nodes[0]);
-               btrfs_crit(fs_info, "unable to update root key %llu %u %llu",
-                          key->objectid, key->type, key->offset);
-               BUG_ON(1);
+       if (ret > 0) {
+               btrfs_crit(fs_info,
+                       "unable to find root key (%llu %u %llu) in tree %llu",
+                       key->objectid, key->type, key->offset,
+                       root->root_key.objectid);
+               ret = -EUCLEAN;
+               btrfs_abort_transaction(trans, ret);
+               goto out;
        }
 
        l = path->nodes[0];
-- 
2.20.1