1 files changed, 10 insertions, 0 deletions

diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index f1db689667ea..59806e67a175 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -925,6 +925,16 @@ static int dm_merge_bvec(struct request_queue *q,
          */
         if (max_size && ti->type->merge)
                 max_size = ti->type->merge(ti, bvm, biovec, max_size);
+        /*
+         * If the target doesn't support merge method and some of the devices
+         * provided their merge_bvec method (we know this by looking at
+         * queue_max_hw_sectors), then we can't allow bios with multiple vector
+         * entries.  So always set max_size to 0, and the code below allows
+         * just one page.
+         */
+        else if (queue_max_hw_sectors(q) <= PAGE_SIZE >> 9)
+
+                max_size = 0;
 
 out_table:
         dm_table_put(map);