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, 2 insertions, 0 deletions

diff --git a/include/linux/fs.h b/include/linux/fs.h
index 267d02630517..7a0625e26a39 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -174,6 +174,7 @@ struct inodes_stat_t {
  */
 #define DISCARD_NOBARRIER       (WRITE | REQ_DISCARD)
 #define DISCARD_BARRIER         (WRITE | REQ_DISCARD | REQ_HARDBARRIER)
+#define DISCARD_SECURE          (DISCARD_NOBARRIER | REQ_SECURE)
 
 #define SEL_IN          1
 #define SEL_OUT         2
@@ -317,6 +318,7 @@ struct inodes_stat_t {
 #define BLKALIGNOFF _IO(0x12,122)
 #define BLKPBSZGET _IO(0x12,123)
 #define BLKDISCARDZEROES _IO(0x12,124)
+#define BLKSECDISCARD _IO(0x12,125)
 
 #define BMAP_IOCTL 1            /* obsolete - kept for compatibility */
 #define FIBMAP     _IO(0x00,1)  /* bmap access */