aboutsummaryrefslogtreecommitdiff
diff options
context:
space:
mode:
-rw-r--r--drivers/md/dm-snap.c16
-rw-r--r--drivers/md/dm-snap.h2
2 files changed, 17 insertions, 1 deletions
diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index 746603b42f8..6c96db26b87 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -370,6 +370,7 @@ static struct dm_snap_pending_exception *alloc_pending_exception(struct dm_snaps
struct dm_snap_pending_exception *pe = mempool_alloc(s->pending_pool,
GFP_NOIO);
+ atomic_inc(&s->pending_exceptions_count);
pe->snap = s;
return pe;
@@ -377,7 +378,11 @@ static struct dm_snap_pending_exception *alloc_pending_exception(struct dm_snaps
static void free_pending_exception(struct dm_snap_pending_exception *pe)
{
- mempool_free(pe, pe->snap->pending_pool);
+ struct dm_snapshot *s = pe->snap;
+
+ mempool_free(pe, s->pending_pool);
+ smp_mb__before_atomic_dec();
+ atomic_dec(&s->pending_exceptions_count);
}
static void insert_completed_exception(struct dm_snapshot *s,
@@ -602,6 +607,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
s->valid = 1;
s->active = 0;
+ atomic_set(&s->pending_exceptions_count, 0);
init_rwsem(&s->lock);
spin_lock_init(&s->pe_lock);
s->ti = ti;
@@ -728,6 +734,14 @@ static void snapshot_dtr(struct dm_target *ti)
/* After this returns there can be no new kcopyd jobs. */
unregister_snapshot(s);
+ while (atomic_read(&s->pending_exceptions_count))
+ yield();
+ /*
+ * Ensure instructions in mempool_destroy aren't reordered
+ * before atomic_read.
+ */
+ smp_mb();
+
#ifdef CONFIG_DM_DEBUG
for (i = 0; i < DM_TRACKED_CHUNK_HASH_SIZE; i++)
BUG_ON(!hlist_empty(&s->tracked_chunk_hash[i]));
diff --git a/drivers/md/dm-snap.h b/drivers/md/dm-snap.h
index f07315fe236..99c0106ede2 100644
--- a/drivers/md/dm-snap.h
+++ b/drivers/md/dm-snap.h
@@ -160,6 +160,8 @@ struct dm_snapshot {
mempool_t *pending_pool;
+ atomic_t pending_exceptions_count;
+
struct exception_table pending;
struct exception_table complete;