diff options
Diffstat (limited to 'block/blk-lib.c')
| -rw-r--r-- | block/blk-lib.c | 34 |
1 files changed, 24 insertions, 10 deletions
diff --git a/block/blk-lib.c b/block/blk-lib.c index 16b06f6..19cc761 100644 --- a/block/blk-lib.c +++ b/block/blk-lib.c @@ -44,7 +44,7 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, struct request_queue *q = bdev_get_queue(bdev); int type = REQ_WRITE | REQ_DISCARD; unsigned int max_discard_sectors; - unsigned int granularity; + unsigned int granularity, alignment, mask; struct bio_batch bb; struct bio *bio; int ret = 0; @@ -57,10 +57,12 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, /* Zero-sector (unknown) and one-sector granularities are the same. */ granularity = max(q->limits.discard_granularity >> 9, 1U); + mask = granularity - 1; + alignment = (bdev_discard_alignment(bdev) >> 9) & mask; /* * Ensure that max_discard_sectors is of the proper - * granularity + * granularity, so that requests stay aligned after a split. */ max_discard_sectors = min(q->limits.max_discard_sectors, UINT_MAX >> 9); max_discard_sectors = round_down(max_discard_sectors, granularity); @@ -80,25 +82,37 @@ int blkdev_issue_discard(struct block_device *bdev, sector_t sector, bb.wait = &wait; while (nr_sects) { + unsigned int req_sects; + sector_t end_sect; + bio = bio_alloc(gfp_mask, 1); if (!bio) { ret = -ENOMEM; break; } + req_sects = min_t(sector_t, nr_sects, max_discard_sectors); + + /* + * If splitting a request, and the next starting sector would be + * misaligned, stop the discard at the previous aligned sector. + */ + end_sect = sector + req_sects; + if (req_sects < nr_sects && (end_sect & mask) != alignment) { + end_sect = + round_down(end_sect - alignment, granularity) + + alignment; + req_sects = end_sect - sector; + } + bio->bi_sector = sector; bio->bi_end_io = bio_batch_end_io; bio->bi_bdev = bdev; bio->bi_private = &bb; - if (nr_sects > max_discard_sectors) { - bio->bi_size = max_discard_sectors << 9; - nr_sects -= max_discard_sectors; - sector += max_discard_sectors; - } else { - bio->bi_size = nr_sects << 9; - nr_sects = 0; - } + bio->bi_size = req_sects << 9; + nr_sects -= req_sects; + sector = end_sect; atomic_inc(&bb.done); submit_bio(type, bio); |