From 885fa13f655940c73787b7fcd4c78813943ece8a Mon Sep 17 00:00:00 2001
From: Christoph Hellwig <hch@lst.de>
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 <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>
---
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 2afa262425d10..3990ae4063412 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);
--
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