ext4: add missing brelse() in set_flexbg_block_bitmap()'s error path

BugLink: https://bugs.launchpad.net/bugs/1810947

commit cea57941 upstream.

Fixes: 33afdcc5 ("ext4: add a function which sets up group blocks ...")
Cc: stable@kernel.org # 3.3
Signed-off-by: Vasily Averin <vvs@virtuozzo.com>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Signed-off-by: Juerg Haefliger <juergh@canonical.com>
Signed-off-by: Kleber Sacilotto de Souza <kleber.souza@canonical.com>

fs/ext4/resize.c

@@ -442,16 +442,18 @@ static int set_flexbg_block_bitmap(struct super_block *sb, handle_t *handle,
 
 		BUFFER_TRACE(bh, "get_write_access");
 		err = ext4_journal_get_write_access(handle, bh);
-		if (err)
+		if (err) {
+			brelse(bh);
 			return err;
+		}
 		ext4_debug("mark block bitmap %#04llx (+%llu/%u)\n", block,
 			   block - start, count2);
 		ext4_set_bits(bh->b_data, block - start, count2);
 
 		err = ext4_handle_dirty_metadata(handle, NULL, bh);
+		brelse(bh);
 		if (unlikely(err))
 			return err;
-		brelse(bh);
 	}
 
 	return 0;