btrfs: always drop log root tree reference in btrfs_replay_log()

[ Upstream commit 2f5b8095ea ]

Currently we have this odd behaviour:

1) At btrfs_replay_log() we drop the reference of the log root tree if
   the call to btrfs_recover_log_trees() failed;

2) But if the call to btrfs_recover_log_trees() did not fail, we don't
   drop the reference in btrfs_replay_log() - we expect that
   btrfs_recover_log_trees() does it in case it returns success.

Let's simplify this and make btrfs_replay_log() always drop the reference
on the log root tree, not only this simplifies code as it's what makes
sense since it's btrfs_replay_log() who grabbed the reference in the first
place.

Signed-off-by: Filipe Manana <fdmanana@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/disk-io.c

@@ -2080,10 +2080,10 @@ static int btrfs_replay_log(struct btrfs_fs_info *fs_info,
 
 	/* returns with log_tree_root freed on success */
 	ret = btrfs_recover_log_trees(log_tree_root);
+	btrfs_put_root(log_tree_root);
 	if (ret) {
 		btrfs_handle_fs_error(fs_info, ret,
 				      "Failed to recover log tree");
-		btrfs_put_root(log_tree_root);
 		return ret;
 	}
 

fs/btrfs/tree-log.c

@@ -7422,7 +7422,6 @@ next:
 
 	log_root_tree->log_root = NULL;
 	clear_bit(BTRFS_FS_LOG_RECOVERING, &fs_info->flags);
-	btrfs_put_root(log_root_tree);
 
 	return 0;
 error: