From 885fa13f655940c73787b7fcd4c78813943ece8a Mon Sep 17 00:00:00 2001 From: Christoph Hellwig Date: Wed, 5 Apr 2017 19:21:01 +0200 Subject: [PATCH] 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 Reviewed-by: Martin K. Petersen Reviewed-by: Hannes Reinecke Signed-off-by: Jens Axboe --- block/blk-merge.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/block/blk-merge.c b/block/blk-merge.c index 2afa262425d1..3990ae406341 100644 --- a/block/blk-merge.c +++ b/block/blk-merge.c @@ -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);