dm space map metadata: fix 'struct sm_metadata' leak on failed create

In dm_sm_metadata_create() we temporarily change the dm_space_map
operations from 'ops' (whose .destroy function deallocates the
sm_metadata) to 'bootstrap_ops' (whose .destroy function doesn't).

If dm_sm_metadata_create() fails in sm_ll_new_metadata() or
sm_ll_extend(), it exits back to dm_tm_create_internal(), which calls
dm_sm_destroy() with the intention of freeing the sm_metadata, but it
doesn't (because the dm_space_map operations is still set to
'bootstrap_ops').

Fix this by setting the dm_space_map operations back to 'ops' if
dm_sm_metadata_create() fails when it is set to 'bootstrap_ops'.

Signed-off-by: Benjamin Marzinski <bmarzins@redhat.com>
Acked-by: Joe Thornber <ejt@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Cc: stable@vger.kernel.org

1 files changed, 6 insertions, 8 deletions

diff --git a/drivers/md/persistent-data/dm-space-map-metadata.c b/drivers/md/persistent-data/dm-space-map-metadata.c
index 7e44005595c1..20557e2c60c6 100644
--- a/drivers/md/persistent-data/dm-space-map-metadata.c
+++ b/drivers/md/persistent-data/dm-space-map-metadata.c
@@ -775,17 +775,15 @@ int dm_sm_metadata_create(struct dm_space_map *sm,
         memcpy(&smm->sm, &bootstrap_ops, sizeof(smm->sm));
 
         r = sm_ll_new_metadata(&smm->ll, tm);
+        if (!r) {
+                if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
+                        nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
+                r = sm_ll_extend(&smm->ll, nr_blocks);
+        }
+        memcpy(&smm->sm, &ops, sizeof(smm->sm));
         if (r)
                 return r;
 
-        if (nr_blocks > DM_SM_METADATA_MAX_BLOCKS)
-                nr_blocks = DM_SM_METADATA_MAX_BLOCKS;
-        r = sm_ll_extend(&smm->ll, nr_blocks);
-        if (r)
-                return r;
-
-        memcpy(&smm->sm, &ops, sizeof(smm->sm));
-
         /*
          * Now we need to update the newly created data structures with the
          * allocated blocks that they were built from.