ext4: avoid buffer_head leak in ext4_mark_inode_used()

Release inode_bitmap_bh from ext4_read_inode_bitmap() in
ext4_mark_inode_used() to avoid buffer_head leak.
By the way, remove unneeded goto for invalid ino when inode_bitmap_bh
is NULL.

Fixes: 8016e29f ("ext4: fast commit recovery path")
Signed-off-by: Kemeng Shi <shikemeng@huaweicloud.com>
Link: https://patch.msgid.link/20240820132234.2759926-2-shikemeng@huaweicloud.comSigned-off-by: Theodore Ts'o <tytso@mit.edu>

fs/ext4/ialloc.c

@@ -755,10 +755,10 @@ int ext4_mark_inode_used(struct super_block *sb, int ino)
 	struct ext4_group_desc *gdp;
 	ext4_group_t group;
 	int bit;
-	int err = -EFSCORRUPTED;
+	int err;
 
 	if (ino < EXT4_FIRST_INO(sb) || ino > max_ino)
-		goto out;
+		return -EFSCORRUPTED;
 
 	group = (ino - 1) / EXT4_INODES_PER_GROUP(sb);
 	bit = (ino - 1) % EXT4_INODES_PER_GROUP(sb);
@@ -860,6 +860,7 @@ int ext4_mark_inode_used(struct super_block *sb, int ino)
 	err = ext4_handle_dirty_metadata(NULL, NULL, group_desc_bh);
 	sync_dirty_buffer(group_desc_bh);
 out:
+	brelse(inode_bitmap_bh);
 	return err;
 }