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

diff --git a/block/blk-merge.c b/block/blk-merge.c
index 3b0cd4249671d9826b42ea10473a11486c403368..eafc94f68d79f2ceb1c0a89fce8e449c3a5ff3f6 100644 (file)
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -361,6 +361,18 @@ static int attempt_merge(struct request_queue *q, struct request *req,
        if (!rq_mergeable(req) || !rq_mergeable(next))
                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
         */