block: don't honor chunk sizes for data-less IO

We don't need to honor chunk sizes for IO that doesn't carry any data.

Jens Axboe committed 11 years ago

Commit e548ca41 parent beefa6b1 file · +1 −1Browse files

Unified · Split

include/linux/blkdev.h+1−1

@@ -903,7 +903,7 @@ static inline unsigned int blk_rq_get_max_sectors(struct request *rq) · 902 unmodified lines
903	if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))	903	if (unlikely(rq->cmd_type == REQ_TYPE_BLOCK_PC))
904	return q->limits.max_hw_sectors;	904	return q->limits.max_hw_sectors;
905		905
906	if (!q->limits.chunk_sectors)	906	if (!q->limits.chunk_sectors \|\| (rq->cmd_flags & REQ_DISCARD))
907	return blk_queue_get_max_sectors(q, rq->cmd_flags);	907	return blk_queue_get_max_sectors(q, rq->cmd_flags);
908		908
909	return min(blk_max_size_offset(q, blk_rq_pos(rq)),	909	return min(blk_max_size_offset(q, blk_rq_pos(rq)),