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authorMilan Broz <mbroz@redhat.com>2008-07-21 12:00:38 +0100
committerAlasdair G Kergon <agk@redhat.com>2008-07-21 12:00:38 +0100
commit7bc3447b692185c5ea78bee93d0ef1dee2fd7ce7 (patch)
treef30ddd021bcbb333f12b1a57a6969e0d52b7cdab /drivers/md/dm-linear.c
parentf6fccb1213ba3d661baeb2a5eee0a9701dc03e1b (diff)
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 <mbroz@redhat.com> Signed-off-by: Alasdair G Kergon <agk@redhat.com>
Diffstat (limited to 'drivers/md/dm-linear.c')
-rw-r--r--drivers/md/dm-linear.c38
1 files changed, 33 insertions, 5 deletions
diff --git a/drivers/md/dm-linear.c b/drivers/md/dm-linear.c
index 17753d80ad2..6449bcdf84c 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)