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>

1 files changed, 6 insertions, 1 deletions

diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 89c855c5655c..2c54906f678f 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -389,6 +389,7 @@ struct request_queue
 #define QUEUE_FLAG_DISCARD     16       /* supports DISCARD */
 #define QUEUE_FLAG_NOXMERGES   17       /* No extended merges */
 #define QUEUE_FLAG_ADD_RANDOM  18       /* Contributes to random pool */
+#define QUEUE_FLAG_SECDISCARD  19       /* supports SECDISCARD */
 
 #define QUEUE_FLAG_DEFAULT      ((1 << QUEUE_FLAG_IO_STAT) |            \
                                  (1 << QUEUE_FLAG_CLUSTER) |            \
@@ -524,6 +525,8 @@ enum {
 #define blk_queue_stackable(q)  \
         test_bit(QUEUE_FLAG_STACKABLE, &(q)->queue_flags)
 #define blk_queue_discard(q)    test_bit(QUEUE_FLAG_DISCARD, &(q)->queue_flags)
+#define blk_queue_secdiscard(q) (blk_queue_discard(q) && \
+        test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 
 #define blk_noretry_request(rq) \
         ((rq)->cmd_flags & (REQ_FAILFAST_DEV|REQ_FAILFAST_TRANSPORT| \
@@ -918,10 +921,12 @@ static inline struct request *blk_map_queue_find_tag(struct blk_queue_tag *bqt,
 }
 enum{
         BLKDEV_WAIT,    /* wait for completion */
-        BLKDEV_BARRIER, /*issue request with barrier */
+        BLKDEV_BARRIER, /* issue request with barrier */
+        BLKDEV_SECURE,  /* secure discard */
 };
 #define BLKDEV_IFL_WAIT         (1 << BLKDEV_WAIT)
 #define BLKDEV_IFL_BARRIER      (1 << BLKDEV_BARRIER)
+#define BLKDEV_IFL_SECURE       (1 << BLKDEV_SECURE)
 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *,
                         unsigned long);
 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,