From 0cfbcafcae8b7364b5fa96c2b26ccde7a3a296a9 Mon Sep 17 00:00:00 2001 From: Shaohua Li Date: Fri, 14 Dec 2012 11:15:51 +0800 Subject: [PATCH] block: add plug for blkdev_issue_discard Last post of this patch appears lost, so I resend this. Now discard merge works, add plug for blkdev_issue_discard. This will help discard request merge especially for raid0 case. In raid0, a big discard request is split to small requests, and if correct plug is added, such small requests can be merged in low layer. Signed-off-by: Shaohua Li Signed-off-by: Jens Axboe --- block/blk-lib.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/block/blk-lib.c b/block/blk-lib.c index 5677fd33d7d..b3a1f2b70b3 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -48,6 +48,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, struct bio_batch bb; struct bio *bio; int ret = 0; + struct blk_plug plug; if (!q) return -ENXIO; @@ -82,6 +83,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, bb.flags = 1 << BIO_UPTODATE; bb.wait = &wait; + blk_start_plug(&plug); while (nr_sects) { unsigned int req_sects; sector_t end_sect, tmp; @@ -120,6 +122,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, atomic_inc(&bb.done); submit_bio(type, bio); } + blk_finish_plug(&plug); /* Wait for bios in-flight */ if (!atomic_dec_and_test(&bb.done))