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Diffstat (limited to 'drivers/md/dm-snap.c')
-rw-r--r--drivers/md/dm-snap.c34
1 files changed, 32 insertions, 2 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index d73f17fc777..57f1bf7f3b7 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -678,6 +678,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
ti->private = s;
ti->split_io = s->store->chunk_size;
+ ti->num_flush_requests = 1;
return 0;
@@ -1030,6 +1031,11 @@ static int snapshot_map(struct dm_target *ti, struct bio *bio,
chunk_t chunk;
struct dm_snap_pending_exception *pe = NULL;
+ if (unlikely(bio_empty_barrier(bio))) {
+ bio->bi_bdev = s->store->cow->bdev;
+ return DM_MAPIO_REMAPPED;
+ }
+
chunk = sector_to_chunk(s->store, bio->bi_sector);
/* Full snapshots are not usable */
@@ -1170,6 +1176,15 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
return 0;
}
+static int snapshot_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct dm_snapshot *snap = ti->private;
+
+ return fn(ti, snap->origin, 0, ti->len, data);
+}
+
+
/*-----------------------------------------------------------------
* Origin methods
*---------------------------------------------------------------*/
@@ -1338,6 +1353,8 @@ static int origin_ctr(struct dm_target *ti, unsigned int argc, char **argv)
}
ti->private = dev;
+ ti->num_flush_requests = 1;
+
return 0;
}
@@ -1353,6 +1370,9 @@ static int origin_map(struct dm_target *ti, struct bio *bio,
struct dm_dev *dev = ti->private;
bio->bi_bdev = dev->bdev;
+ if (unlikely(bio_empty_barrier(bio)))
+ return DM_MAPIO_REMAPPED;
+
/* Only tell snapshots if this is a write */
return (bio_rw(bio) == WRITE) ? do_origin(dev, bio) : DM_MAPIO_REMAPPED;
}
@@ -1399,20 +1419,29 @@ static int origin_status(struct dm_target *ti, status_type_t type, char *result,
return 0;
}
+static int origin_iterate_devices(struct dm_target *ti,
+ iterate_devices_callout_fn fn, void *data)
+{
+ struct dm_dev *dev = ti->private;
+
+ return fn(ti, dev, 0, ti->len, data);
+}
+
static struct target_type origin_target = {
.name = "snapshot-origin",
- .version = {1, 6, 0},
+ .version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = origin_ctr,
.dtr = origin_dtr,
.map = origin_map,
.resume = origin_resume,
.status = origin_status,
+ .iterate_devices = origin_iterate_devices,
};
static struct target_type snapshot_target = {
.name = "snapshot",
- .version = {1, 6, 0},
+ .version = {1, 7, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
@@ -1420,6 +1449,7 @@ static struct target_type snapshot_target = {
.end_io = snapshot_end_io,
.resume = snapshot_resume,
.status = snapshot_status,
+ .iterate_devices = snapshot_iterate_devices,
};
static int __init dm_snapshot_init(void)