dm exception store: move dm_target pointer

Move target pointer from snapshot to exception store.
Signed-off-by: NJonathan Brassow <jbrassow@redhat.com>
Signed-off-by: NAlasdair G Kergon <agk@redhat.com>

drivers/md/dm-exception-store.c

@@ -137,7 +137,7 @@ int dm_exception_store_type_unregister(struct dm_exception_store_type *type)
 }
 EXPORT_SYMBOL(dm_exception_store_type_unregister);
 
-int dm_exception_store_create(const char *type_name,
+int dm_exception_store_create(const char *type_name, struct dm_target *ti,
 			      struct dm_exception_store **store)
 {
 	int r = 0;
@@ -155,6 +155,7 @@ int dm_exception_store_create(const char *type_name,
 	}
 
 	tmp_store->type = type;
+	tmp_store->ti = ti;
 
 	r = type->ctr(tmp_store, 0, NULL);
 	if (r) {

drivers/md/dm-exception-store.h

@@ -95,6 +95,7 @@ struct dm_exception_store_type {
 
 struct dm_exception_store {
 	struct dm_exception_store_type *type;
+	struct dm_target *ti;
 
 	struct dm_snapshot *snap;
 
@@ -147,7 +148,7 @@ static inline void dm_consecutive_chunk_count_inc(struct dm_snap_exception *e)
 int dm_exception_store_type_register(struct dm_exception_store_type *type);
 int dm_exception_store_type_unregister(struct dm_exception_store_type *type);
 
-int dm_exception_store_create(const char *type_name,
+int dm_exception_store_create(const char *type_name, struct dm_target *ti,
 			      struct dm_exception_store **store);
 void dm_exception_store_destroy(struct dm_exception_store *store);
 

drivers/md/dm-snap.c

@@ -615,7 +615,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 	atomic_set(&s->pending_exceptions_count, 0);
 	init_rwsem(&s->lock);
 	spin_lock_init(&s->pe_lock);
-	s->ti = ti;
 
 	/* Allocate hash table for COW data */
 	if (init_hash_tables(s)) {
@@ -624,7 +623,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
 		goto bad3;
 	}
 
-	r = dm_exception_store_create(argv[2], &s->store);
+	r = dm_exception_store_create(argv[2], ti, &s->store);
 	if (r) {
 		ti->error = "Couldn't create exception store";
 		r = -EINVAL;
@@ -820,7 +819,7 @@ static void __invalidate_snapshot(struct dm_snapshot *s, int err)
 
 	s->valid = 0;
 
-	dm_table_event(s->ti->table);
+	dm_table_event(s->store->ti->table);
 }
 
 static void get_pending_exception(struct dm_snap_pending_exception *pe)
@@ -1196,7 +1195,7 @@ static int __origin_write(struct list_head *snapshots, struct bio *bio)
 			goto next_snapshot;
 
 		/* Nothing to do if writing beyond end of snapshot */
-		if (bio->bi_sector >= dm_table_get_size(snap->ti->table))
+		if (bio->bi_sector >= dm_table_get_size(snap->store->ti->table))
 			goto next_snapshot;
 
 		/*

drivers/md/dm-snap.h

@@ -25,7 +25,6 @@ struct exception_table {
 
 struct dm_snapshot {
 	struct rw_semaphore lock;
-	struct dm_target *ti;
 
 	struct dm_dev *origin;
 	struct dm_dev *cow;