diff options
| -rw-r--r-- | drivers/md/dm-io.c | 23 |
1 files changed, 16 insertions, 7 deletions
diff --git a/drivers/md/dm-io.c b/drivers/md/dm-io.c index ad2eba40e319..ea5dd289fe2a 100644 --- a/drivers/md/dm-io.c +++ b/drivers/md/dm-io.c @@ -296,6 +296,8 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, unsigned offset; unsigned num_bvecs; sector_t remaining = where->count; + struct request_queue *q = bdev_get_queue(where->bdev); + sector_t discard_sectors; /* * where->count may be zero if rw holds a flush and we need to @@ -305,9 +307,12 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, /* * Allocate a suitably sized-bio. */ - num_bvecs = dm_sector_div_up(remaining, - (PAGE_SIZE >> SECTOR_SHIFT)); - num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), num_bvecs); + if (rw & REQ_DISCARD) + num_bvecs = 1; + else + num_bvecs = min_t(int, bio_get_nr_vecs(where->bdev), + dm_sector_div_up(remaining, (PAGE_SIZE >> SECTOR_SHIFT))); + bio = bio_alloc_bioset(GFP_NOIO, num_bvecs, io->client->bios); bio->bi_sector = where->sector + (where->count - remaining); bio->bi_bdev = where->bdev; @@ -315,10 +320,14 @@ static void do_region(int rw, unsigned region, struct dm_io_region *where, bio->bi_destructor = dm_bio_destructor; store_io_and_region_in_bio(bio, io, region); - /* - * Try and add as many pages as possible. - */ - while (remaining) { + if (rw & REQ_DISCARD) { + discard_sectors = min_t(sector_t, q->limits.max_discard_sectors, remaining); + bio->bi_size = discard_sectors << SECTOR_SHIFT; + remaining -= discard_sectors; + } else while (remaining) { + /* + * Try and add as many pages as possible. + */ dp->get_page(dp, &page, &len, &offset); len = min(len, to_bytes(remaining)); if (!bio_add_page(bio, page, len, offset)) |