[PATCH AUTOSEL 5.1 059/375] btrfs: Don't panic when we can't find a root key

Sasha Levin
2019-05-22T19:23:02Z

From: Qu Wenruo <wqu@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 <fdmanana@suse.com>
Reviewed-by: Johannes Thumshirn <jthumshirn@suse.de>
Signed-off-by: Qu Wenruo <wqu@suse.com>
Reviewed-by: David Sterba <dsterba@suse.com>
Signed-off-by: David Sterba <dsterba@suse.com>
Signed-off-by: Sasha Levin <sashal@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 893d12fbfda07..1b9a5d0de1392 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