From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: From: Jens Axboe To: linux-xfs@vger.kernel.org, linux-block@vger.kernel.org Cc: hch@lst.de, Jens Axboe Subject: [PATCH 1/2] block: add BLKDEV_DISCARD_SYNC flag Date: Mon, 30 Apr 2018 09:32:51 -0600 Message-Id: <1525102372-8430-2-git-send-email-axboe@kernel.dk> In-Reply-To: <1525102372-8430-1-git-send-email-axboe@kernel.dk> References: <1525102372-8430-1-git-send-email-axboe@kernel.dk> List-ID: By default, blkdev_issue_discard() will build potentially big bio chains, even when the discard size has been limited by the user. Add a BLKDEV_DISCARD_SYNC flag, telling blkdev_issue_discard() to wait for completion of each discard. Signed-off-by: Jens Axboe --- block/blk-lib.c | 33 ++++++++++++++++++++++++--------- include/linux/blkdev.h | 1 + 2 files changed, 25 insertions(+), 9 deletions(-) diff --git a/block/blk-lib.c b/block/blk-lib.c index a676084d4740..1d0263c13c9c 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -11,13 +11,18 @@ #include "blk.h" static struct bio *next_bio(struct bio *bio, unsigned int nr_pages, - gfp_t gfp) + gfp_t gfp, bool do_sync) { struct bio *new = bio_alloc(gfp, nr_pages); if (bio) { - bio_chain(bio, new); - submit_bio(bio); + if (do_sync) { + submit_bio_wait(bio); + bio_put(bio); + } else { + bio_chain(bio, new); + submit_bio(bio); + } } return new; @@ -30,7 +35,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, struct request_queue *q = bdev_get_queue(bdev); struct bio *bio = *biop; unsigned int granularity; - unsigned int op; + unsigned int op, max_sectors; int alignment; sector_t bs_mask; @@ -58,12 +63,17 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, granularity = max(q->limits.discard_granularity >> 9, 1U); alignment = (bdev_discard_alignment(bdev) >> 9) % granularity; + if (flags & BLKDEV_DISCARD_SYNC) + max_sectors = q->limits.max_discard_sectors; + else + max_sectors = UINT_MAX >> 9; + while (nr_sects) { unsigned int req_sects; sector_t end_sect, tmp; /* Make sure bi_size doesn't overflow */ - req_sects = min_t(sector_t, nr_sects, UINT_MAX >> 9); + req_sects = min_t(sector_t, nr_sects, max_sectors); /** * If splitting a request, and the next starting sector would be @@ -79,7 +89,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, req_sects = end_sect - sector; } - bio = next_bio(bio, 0, gfp_mask); + bio = next_bio(bio, 0, gfp_mask, flags & BLKDEV_DISCARD_SYNC); bio->bi_iter.bi_sector = sector; bio_set_dev(bio, bdev); bio_set_op_attrs(bio, op, 0); @@ -97,6 +107,11 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector, cond_resched(); } + if (bio && (flags & BLKDEV_DISCARD_SYNC)) { + submit_bio_wait(bio); + bio_put(bio); + bio = NULL; + } *biop = bio; return 0; } @@ -173,7 +188,7 @@ static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector, max_write_same_sectors = UINT_MAX >> 9; while (nr_sects) { - bio = next_bio(bio, 1, gfp_mask); + bio = next_bio(bio, 1, gfp_mask, false); bio->bi_iter.bi_sector = sector; bio_set_dev(bio, bdev); bio->bi_vcnt = 1; @@ -249,7 +264,7 @@ static int __blkdev_issue_write_zeroes(struct block_device *bdev, return -EOPNOTSUPP; while (nr_sects) { - bio = next_bio(bio, 0, gfp_mask); + bio = next_bio(bio, 0, gfp_mask, false); bio->bi_iter.bi_sector = sector; bio_set_dev(bio, bdev); bio->bi_opf = REQ_OP_WRITE_ZEROES; @@ -301,7 +316,7 @@ static int __blkdev_issue_zero_pages(struct block_device *bdev, while (nr_sects != 0) { bio = next_bio(bio, __blkdev_sectors_to_bio_pages(nr_sects), - gfp_mask); + gfp_mask, false); bio->bi_iter.bi_sector = sector; bio_set_dev(bio, bdev); bio_set_op_attrs(bio, REQ_OP_WRITE, 0); diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h index 5c4eee043191..e90388004029 100644 --- a/include/linux/blkdev.h +++ b/include/linux/blkdev.h @@ -1396,6 +1396,7 @@ extern int blkdev_issue_write_same(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, struct page *page); #define BLKDEV_DISCARD_SECURE (1 << 0) /* issue a secure erase */ +#define BLKDEV_DISCARD_SYNC (1 << 1) extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector, sector_t nr_sects, gfp_t gfp_mask, unsigned long flags); -- 2.7.4