1 files changed, 9 insertions, 0 deletions

diff --git a/drivers/md/dm-raid1.c b/drivers/md/dm-raid1.c
index 7dfdb5c746d6..089d62751f7f 100644
--- a/drivers/md/dm-raid1.c
+++ b/drivers/md/dm-raid1.c
@@ -604,6 +604,15 @@ static void write_callback(unsigned long error, void *context)
                 return;
         }
 
+        /*
+         * If the bio is discard, return an error, but do not
+         * degrade the array.
+         */
+        if (bio->bi_rw & REQ_DISCARD) {
+                bio_endio(bio, -EOPNOTSUPP);
+                return;
+        }
+
         for (i = 0; i < ms->nr_mirrors; i++)
                 if (test_bit(i, &error))
                         fail_mirror(ms->mirror + i, DM_RAID1_WRITE_ERROR);