dm exception store: really fix type lookup

Fix exception store name handling.

We need to reference exception store by zero terminated string.

Fixes regression introduced in commit f6bd4eb73cdf2a5bf954e497972842f39cabb7e3

Cc: Yi Yang <yi.y.yang@intel.com>
Cc: Jonathan Brassow <jbrassow@redhat.com>
Cc: stable@kernel.org
Cc: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Milan Broz <mbroz@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 6 insertions, 3 deletions

diff --git a/drivers/md/dm-exception-store.c b/drivers/md/dm-exception-store.c
index c3ae51584b12..3710ff88fc10 100644
--- a/drivers/md/dm-exception-store.c
+++ b/drivers/md/dm-exception-store.c
@@ -195,7 +195,7 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
                               struct dm_exception_store **store)
 {
         int r = 0;
-        struct dm_exception_store_type *type;
+        struct dm_exception_store_type *type = NULL;
         struct dm_exception_store *tmp_store;
         char persistent;
 
@@ -211,12 +211,15 @@ int dm_exception_store_create(struct dm_target *ti, int argc, char **argv,
         }
 
         persistent = toupper(*argv[1]);
-        if (persistent != 'P' && persistent != 'N') {
+        if (persistent == 'P')
+                type = get_type("P");
+        else if (persistent == 'N')
+                type = get_type("N");
+        else {
                 ti->error = "Persistent flag is not P or N";
                 return -EINVAL;
         }
 
-        type = get_type(&persistent);
         if (!type) {
                 ti->error = "Exception store type not recognised";
                 r = -EINVAL;