block: add secure discard
Secure discard is the same as discard except that all copies of the
discarded sectors (perhaps created by garbage collection) must also be
erased.
Signed-off-by: Adrian Hunter <adrian.hunter@nokia.com>
Acked-by: Jens Axboe <axboe@kernel.dk>
Cc: Kyungmin Park <kmpark@infradead.org>
Cc: Madhusudhan Chikkature <madhu.cr@ti.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Ben Gardiner <bengardiner@nanometrics.ca>
Cc: <linux-mmc@vger.kernel.org>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/block/elevator.c b/block/elevator.c
index 816a7c8..ec585c9 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -83,6 +83,12 @@
return 0;
/*
+ * Don't merge discard requests and secure discard requests
+ */
+ if ((bio->bi_rw & REQ_SECURE) != (rq->bio->bi_rw & REQ_SECURE))
+ return 0;
+
+ /*
* different data direction or already started, don't merge
*/
if (bio_data_dir(bio) != rq_data_dir(rq))