dm snapshot: track suspended state in target
Keep track of whether or not the device is suspended within the snapshot
target module, the same as we do in dm-raid1.
We will use this later to enforce the correct sequence of ioctls to
transfer the in-core exceptions from a snapshot target instance in
one table to a replacement one capable of merging them back
into the origin.
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index dc500a6..fd04caa9 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -72,6 +72,9 @@
/* Origin writes don't trigger exceptions until this is set */
int active;
+ /* Whether or not owning mapped_device is suspended */
+ int suspended;
+
mempool_t *pending_pool;
atomic_t pending_exceptions_count;
@@ -656,6 +659,7 @@
s->ti = ti;
s->valid = 1;
s->active = 0;
+ s->suspended = 0;
atomic_set(&s->pending_exceptions_count, 0);
init_rwsem(&s->lock);
spin_lock_init(&s->pe_lock);
@@ -1175,12 +1179,22 @@
return 0;
}
+static void snapshot_postsuspend(struct dm_target *ti)
+{
+ struct dm_snapshot *s = ti->private;
+
+ down_write(&s->lock);
+ s->suspended = 1;
+ up_write(&s->lock);
+}
+
static void snapshot_resume(struct dm_target *ti)
{
struct dm_snapshot *s = ti->private;
down_write(&s->lock);
s->active = 1;
+ s->suspended = 0;
up_write(&s->lock);
}
@@ -1489,12 +1503,13 @@
static struct target_type snapshot_target = {
.name = "snapshot",
- .version = {1, 8, 0},
+ .version = {1, 9, 0},
.module = THIS_MODULE,
.ctr = snapshot_ctr,
.dtr = snapshot_dtr,
.map = snapshot_map,
.end_io = snapshot_end_io,
+ .postsuspend = snapshot_postsuspend,
.resume = snapshot_resume,
.status = snapshot_status,
.iterate_devices = snapshot_iterate_devices,