dm log writes: use struct_size() to calculate size of pending_block

Use struct_size() to avoid open-coded equivalent that is prone to a type
mistake.

Signed-off-by: Zhengyuan Liu <liuzhengyuan@kylinos.cn>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>

diff --git a/drivers/md/dm-log-writes.c b/drivers/md/dm-log-writes.c
index e549392e0ea517a55ec672a95a909a8082d19414..0837b17e17988e9bfd46d389ed0d60ef3086e4d9 100644 (file)
--- a/drivers/md/dm-log-writes.c
+++ b/drivers/md/dm-log-writes.c
@@ -699,7 +699,7 @@ static int log_writes_map(struct dm_target *ti, struct bio *bio)
        if (discard_bio)
                alloc_size = sizeof(struct pending_block);
        else
-               alloc_size = sizeof(struct pending_block) + sizeof(struct bio_vec) * bio_segments(bio);
+               alloc_size = struct_size(block, vecs, bio_segments(bio));
 
        block = kzalloc(alloc_size, GFP_NOIO);
        if (!block) {