From 7bc3447b692185c5ea78bee93d0ef1dee2fd7ce7 Mon Sep 17 00:00:00 2001 From: Milan Broz Date: Mon, 21 Jul 2008 12:00:38 +0100 Subject: dm: linear add merge This patch implements biovec merge function for linear target. If the underlying device has merge function defined, call it. If not, keep precomputed value. Signed-off-by: Milan Broz Signed-off-by: Alasdair G Kergon --- drivers/md/dm-linear.c | 38 +++++++++++++++++++++++++++++++++----- 1 file changed, 33 insertions(+), 5 deletions(-) (limited to 'drivers') diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c index 17753d80ad22..6449bcdf84ca 100644 --- a/drivers/md/dm-linear.c +++ b/drivers/md/dm-linear.c @@ -69,13 +69,25 @@ static void linear_dtr(struct dm_target *ti) kfree(lc); } -static int linear_map(struct dm_target *ti, struct bio *bio, - union map_info *map_context) +static sector_t linear_map_sector(struct dm_target *ti, sector_t bi_sector) { - struct linear_c *lc = (struct linear_c *) ti->private; + struct linear_c *lc = ti->private; + + return lc->start + (bi_sector - ti->begin); +} + +static void linear_map_bio(struct dm_target *ti, struct bio *bio) +{ + struct linear_c *lc = ti->private; bio->bi_bdev = lc->dev->bdev; - bio->bi_sector = lc->start + (bio->bi_sector - ti->begin); + bio->bi_sector = linear_map_sector(ti, bio->bi_sector); +} + +static int linear_map(struct dm_target *ti, struct bio *bio, + union map_info *map_context) +{ + linear_map_bio(ti, bio); return DM_MAPIO_REMAPPED; } @@ -114,15 +126,31 @@ static int linear_ioctl(struct dm_target *ti, struct inode *inode, return blkdev_driver_ioctl(bdev->bd_inode, &fake_file, bdev->bd_disk, cmd, arg); } +static int linear_merge(struct dm_target *ti, struct bvec_merge_data *bvm, + struct bio_vec *biovec, int max_size) +{ + struct linear_c *lc = ti->private; + struct request_queue *q = bdev_get_queue(lc->dev->bdev); + + if (!q->merge_bvec_fn) + return max_size; + + bvm->bi_bdev = lc->dev->bdev; + bvm->bi_sector = linear_map_sector(ti, bvm->bi_sector); + + return min(max_size, q->merge_bvec_fn(q, bvm, biovec)); +} + static struct target_type linear_target = { .name = "linear", - .version= {1, 0, 2}, + .version= {1, 0, 3}, .module = THIS_MODULE, .ctr = linear_ctr, .dtr = linear_dtr, .map = linear_map, .status = linear_status, .ioctl = linear_ioctl, + .merge = linear_merge, }; int __init dm_linear_init(void) -- cgit v1.2.1