dm thin: fix memory leak in process_prepared_mapping error paths

Fix memory leak in process_prepared_mapping by always freeing
the dm_thin_new_mapping structs from the mapping_pool mempool on
the error paths.

Signed-off-by: Joe Thornber <ejt@redhat.com>
Cc: stable@vger.kernel.org
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

1 files changed, 3 insertions, 2 deletions

diff --git a/drivers/md/dm-thin.c b/drivers/md/dm-thin.c
index 93e3e542cff9..423df92f1c19 100644
--- a/drivers/md/dm-thin.c
+++ b/drivers/md/dm-thin.c
@@ -870,7 +870,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
 
         if (m->err) {
                 cell_error(m->cell);
-                return;
+                goto out;
         }
 
         /*
@@ -882,7 +882,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
         if (r) {
                 DMERR("dm_thin_insert_block() failed");
                 cell_error(m->cell);
-                return;
+                goto out;
         }
 
         /*
@@ -897,6 +897,7 @@ static void process_prepared_mapping(struct dm_thin_new_mapping *m)
         } else
                 cell_defer(tc, m->cell, m->data_block);
 
+out:
         list_del(&m->list);
         mempool_free(m, tc->pool->mapping_pool);
 }