Merge branch 'for-linus' of git://git.kernel.dk/linux-2.6-block

* 'for-linus' of git://git.kernel.dk/linux-2.6-block:
  block: prevent merges of discard and write requests

1 files changed, 12 insertions, 0 deletions

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3b0cd4249671..eafc94f68d79 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -362,6 +362,18 @@ static int attempt_merge(struct request_queue *q, struct request *req,
                 return 0;
 
         /*
+         * Don't merge file system requests and discard requests
+         */
+        if ((req->cmd_flags & REQ_DISCARD) != (next->cmd_flags & REQ_DISCARD))
+                return 0;
+
+        /*
+         * Don't merge discard requests and secure discard requests
+         */
+        if ((req->cmd_flags & REQ_SECURE) != (next->cmd_flags & REQ_SECURE))
+                return 0;
+
+        /*
          * not contiguous
          */
         if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))