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| author |   Christoph Hellwig <hch@lst.de> | 2017-01-13 12:29:10 +0100 |
|---|---|---|
| committer |   Jens Axboe <axboe@fb.com> | 2017-01-13 15:17:04 -0700 |
| commit | 2e3258ecfaebace1ceffaa14e0ea94775d54f46f (patch) | |
| tree | fd42995d3a8f5f5cf9106629e85d4144d9379a74 | |
| parent | block: Rename blk_queue_zone_size and bdev_zone_size (diff) | |
| download | linux-dev-2e3258ecfaebace1ceffaa14e0ea94775d54f46f.tar.xz linux-dev-2e3258ecfaebace1ceffaa14e0ea94775d54f46f.zip | |
block: add blk_rq_payload_bytes
Add a helper to calculate the actual data transfer size for special
payload requests.
Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
| -rw-r--r-- | include/linux/blkdev.h | 13 |
1 files changed, 13 insertions, 0 deletions
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index ff3d774f2751..1ca8e8fd1078 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1000,6 +1000,19 @@ static inline unsigned int blk_rq_cur_sectors(const struct request *rq) return blk_rq_cur_bytes(rq) >> 9; } +/* + * Some commands like WRITE SAME have a payload or data transfer size which + * is different from the size of the request. Any driver that supports such + * commands using the RQF_SPECIAL_PAYLOAD flag needs to use this helper to + * calculate the data transfer size. + */ +static inline unsigned int blk_rq_payload_bytes(struct request *rq) +{ + if (rq->rq_flags & RQF_SPECIAL_PAYLOAD) + return rq->special_vec.bv_len; + return blk_rq_bytes(rq); +} + static inline unsigned int blk_queue_get_max_sectors(struct request_queue *q, int op) { |