Commit 7bc3447b authored by Milan Broz's avatar Milan Broz Committed by Alasdair G Kergon

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: default avatarMilan Broz <mbroz@redhat.com>
Signed-off-by: default avatarAlasdair G Kergon <agk@redhat.com>
parent f6fccb12
......@@ -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)
......
Markdown is supported
0%
or
You are about to add 0 people to the discussion. Proceed with caution.
Finish editing this message first!
Please register or to comment