dm exception store: introduce registry

Move exception stores into a registry.

Signed-off-by: Jonathan Brassow <jbrassow@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 18 insertions, 23 deletions

diff --git a/drivers/md/dm-snap.c b/drivers/md/dm-snap.c
index dabd58e9aafc..be698f3a4ae4 100644
--- a/drivers/md/dm-snap.c
+++ b/drivers/md/dm-snap.c
@@ -610,8 +610,6 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         if (r)
                 goto bad3;
 
-        s->type = persistent;
-
         s->valid = 1;
         s->active = 0;
         atomic_set(&s->pending_exceptions_count, 0);
@@ -626,19 +624,15 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
                 goto bad3;
         }
 
-        s->store.snap = s;
-
-        if (persistent == 'P')
-                r = dm_create_persistent(&s->store);
-        else
-                r = dm_create_transient(&s->store);
-
+        r = dm_exception_store_create(argv[2], &s->store);
         if (r) {
                 ti->error = "Couldn't create exception store";
                 r = -EINVAL;
                 goto bad4;
         }
 
+        s->store->snap = s;
+
         r = dm_kcopyd_client_create(SNAPSHOT_PAGES, &s->kcopyd_client);
         if (r) {
                 ti->error = "Could not create kcopyd client";
@@ -665,7 +659,8 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         spin_lock_init(&s->tracked_chunk_lock);
 
         /* Metadata must only be loaded into one table at once */
-        r = s->store.type.read_metadata(&s->store, dm_add_exception, (void *)s);
+        r = s->store->type->read_metadata(s->store, dm_add_exception,
+                                          (void *)s);
         if (r < 0) {
                 ti->error = "Failed to read snapshot metadata";
                 goto bad_load_and_register;
@@ -700,7 +695,7 @@ static int snapshot_ctr(struct dm_target *ti, unsigned int argc, char **argv)
         dm_kcopyd_client_destroy(s->kcopyd_client);
 
  bad5:
-        s->store.type.dtr(&s->store);
+        s->store->type->dtr(s->store);
 
  bad4:
         exit_exception_table(&s->pending, pending_cache);
@@ -725,7 +720,7 @@ static void __free_exceptions(struct dm_snapshot *s)
         exit_exception_table(&s->pending, pending_cache);
         exit_exception_table(&s->complete, exception_cache);
 
-        s->store.type.dtr(&s->store);
+        s->store->type->dtr(s->store);
 }
 
 static void snapshot_dtr(struct dm_target *ti)
@@ -820,8 +815,8 @@ static void __invalidate_snapshot(struct dm_snapshot *s, int err)
         else if (err == -ENOMEM)
                 DMERR("Invalidating snapshot: Unable to allocate exception.");
 
-        if (s->store.type.drop_snapshot)
-                s->store.type.drop_snapshot(&s->store);
+        if (s->store->type->drop_snapshot)
+                s->store->type->drop_snapshot(s->store);
 
         s->valid = 0;
 
@@ -943,8 +938,8 @@ static void copy_callback(int read_err, unsigned long write_err, void *context)
 
         else
                 /* Update the metadata if we are persistent */
-                s->store.type.commit_exception(&s->store, &pe->e,
-                                               commit_callback, pe);
+                s->store->type->commit_exception(s->store, &pe->e,
+                                                 commit_callback, pe);
 }
 
 /*
@@ -1010,7 +1005,7 @@ __find_pending_exception(struct dm_snapshot *s,
         atomic_set(&pe->ref_count, 0);
         pe->started = 0;
 
-        if (s->store.type.prepare_exception(&s->store, &pe->e)) {
+        if (s->store->type->prepare_exception(s->store, &pe->e)) {
                 free_pending_exception(pe);
                 return NULL;
         }
@@ -1149,11 +1144,11 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
                 if (!snap->valid)
                         snprintf(result, maxlen, "Invalid");
                 else {
-                        if (snap->store.type.fraction_full) {
+                        if (snap->store->type->fraction_full) {
                                 sector_t numerator, denominator;
-                                snap->store.type.fraction_full(&snap->store,
-                                                          &numerator,
-                                                          &denominator);
+                                snap->store->type->fraction_full(snap->store,
+                                                                 &numerator,
+                                                                 &denominator);
                                 snprintf(result, maxlen, "%llu/%llu",
                                         (unsigned long long)numerator,
                                         (unsigned long long)denominator);
@@ -1169,9 +1164,9 @@ static int snapshot_status(struct dm_target *ti, status_type_t type,
                  * to make private copies if the output is to
                  * make sense.
                  */
-                snprintf(result, maxlen, "%s %s %c %llu",
+                snprintf(result, maxlen, "%s %s %s %llu",
                          snap->origin->name, snap->cow->name,
-                         snap->type,
+                         snap->store->type->name,
                          (unsigned long long)snap->chunk_size);
                 break;
         }