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
git-mirror · Sep 25, 2010 · 56162ba · 56162ba
2 parents e7553b1 + f281fb5
commit 56162ba
Showing 1 changed file with 12 additions and 0 deletions.
diff --git 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
 	 */