block: implement splitting of REQ_OP_WRITE_ZEROES bios

Copy and past the REQ_OP_WRITE_SAME code to prepare to implementations
that limit the write zeroes size.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
This commit is contained in:
Christoph Hellwig 2017-04-05 19:21:01 +02:00 committed by Jens Axboe
parent 1d62ac1363
commit 885fa13f65

View File

@ -54,6 +54,20 @@ static struct bio *blk_bio_discard_split(struct request_queue *q,
return bio_split(bio, split_sectors, GFP_NOIO, bs);
}
static struct bio *blk_bio_write_zeroes_split(struct request_queue *q,
struct bio *bio, struct bio_set *bs, unsigned *nsegs)
{
*nsegs = 1;
if (!q->limits.max_write_zeroes_sectors)
return NULL;
if (bio_sectors(bio) <= q->limits.max_write_zeroes_sectors)
return NULL;
return bio_split(bio, q->limits.max_write_zeroes_sectors, GFP_NOIO, bs);
}
static struct bio *blk_bio_write_same_split(struct request_queue *q,
struct bio *bio,
struct bio_set *bs,
@ -200,8 +214,7 @@ void blk_queue_split(struct request_queue *q, struct bio **bio,
split = blk_bio_discard_split(q, *bio, bs, &nsegs);
break;
case REQ_OP_WRITE_ZEROES:
split = NULL;
nsegs = (*bio)->bi_phys_segments;
split = blk_bio_write_zeroes_split(q, *bio, bs, &nsegs);
break;
case REQ_OP_WRITE_SAME:
split = blk_bio_write_same_split(q, *bio, bs, &nsegs);