block: ioctl support for sanitize in eMMC 4.5

Adding a new ioctl to support sanitize operation in eMMC
cards version 4.5.
The sanitize ioctl support helps performing this operation
via user application.

Change-Id: I79aa4163e7753a75bed5a26a9a92de902b4b9c21
Signed-off-by: Yaniv Gardi <ygardi@codeaurora.org>
Signed-off-by: Maya Erez <merez@codeaurora.org>
diff --git a/block/blk-core.c b/block/blk-core.c
index 35ae52d..a6a8ccb 100644
--- a/block/blk-core.c
+++ b/block/blk-core.c
@@ -1467,7 +1467,7 @@
 			goto end_io;
 		}
 
-		if (unlikely(!(bio->bi_rw & REQ_DISCARD) &&
+		if (unlikely(!(bio->bi_rw & (REQ_DISCARD | REQ_SANITIZE)) &&
 			     nr_sectors > queue_max_hw_sectors(q))) {
 			printk(KERN_ERR "bio too big device %s (%u > %u)\n",
 			       bdevname(bio->bi_bdev, b),
@@ -1521,6 +1521,14 @@
 			goto end_io;
 		}
 
+		if ((bio->bi_rw & REQ_SANITIZE) &&
+		    (!blk_queue_sanitize(q))) {
+			pr_info("%s - got a SANITIZE request but the queue "
+			       "doesn't support sanitize requests", __func__);
+			err = -EOPNOTSUPP;
+			goto end_io;
+		}
+
 		if (blk_throtl_bio(q, &bio))
 			goto end_io;
 
@@ -1611,7 +1619,8 @@
 	 * If it's a regular read/write or a barrier with data attached,
 	 * go through the normal accounting stuff before submission.
 	 */
-	if (bio_has_data(bio) && !(rw & REQ_DISCARD)) {
+	if (bio_has_data(bio) &&
+	    (!(rw & (REQ_DISCARD | REQ_SANITIZE)))) {
 		if (rw & WRITE) {
 			count_vm_events(PGPGOUT, count);
 		} else {
@@ -1657,7 +1666,7 @@
  */
 int blk_rq_check_limits(struct request_queue *q, struct request *rq)
 {
-	if (rq->cmd_flags & REQ_DISCARD)
+	if (rq->cmd_flags & (REQ_DISCARD | REQ_SANITIZE))
 		return 0;
 
 	if (blk_rq_sectors(rq) > queue_max_sectors(q) ||
diff --git a/block/blk-lib.c b/block/blk-lib.c
index 78e627e..39a7f25 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -112,6 +112,57 @@
 EXPORT_SYMBOL(blkdev_issue_discard);
 
 /**
+ * blkdev_issue_sanitize - queue a sanitize request
+ * @bdev:	blockdev to issue sanitize for
+ * @gfp_mask:	memory allocation flags (for bio_alloc)
+ *
+ * Description:
+ *    Issue a sanitize request for the specified block device
+ */
+int blkdev_issue_sanitize(struct block_device *bdev, gfp_t gfp_mask)
+{
+	DECLARE_COMPLETION_ONSTACK(wait);
+	struct request_queue *q = bdev_get_queue(bdev);
+	int type = REQ_WRITE | REQ_SANITIZE;
+	struct bio_batch bb;
+	struct bio *bio;
+	int ret = 0;
+
+	if (!q)
+		return -ENXIO;
+
+	if (!blk_queue_sanitize(q)) {
+		pr_err("%s - card doesn't support sanitize", __func__);
+		return -EOPNOTSUPP;
+	}
+
+	bio = bio_alloc(gfp_mask, 1);
+	if (!bio)
+		return -ENOMEM;
+
+	atomic_set(&bb.done, 1);
+	bb.flags = 1 << BIO_UPTODATE;
+	bb.wait = &wait;
+
+	bio->bi_end_io = bio_batch_end_io;
+	bio->bi_bdev = bdev;
+	bio->bi_private = &bb;
+
+	atomic_inc(&bb.done);
+	submit_bio(type, bio);
+
+	/* Wait for bios in-flight */
+	if (!atomic_dec_and_test(&bb.done))
+		wait_for_completion(&wait);
+
+	if (!test_bit(BIO_UPTODATE, &bb.flags))
+		ret = -EIO;
+
+	return ret;
+}
+EXPORT_SYMBOL(blkdev_issue_sanitize);
+
+/**
  * blkdev_issue_zeroout - generate number of zero filed write bios
  * @bdev:	blockdev to issue
  * @sector:	start sector
diff --git a/block/blk-merge.c b/block/blk-merge.c
index cfcc37c..f3ed15b 100644
--- a/block/blk-merge.c
+++ b/block/blk-merge.c
@@ -383,6 +383,12 @@
 		return 0;
 
 	/*
+	 * Don't merge file system requests and sanitize requests
+	 */
+	if ((req->cmd_flags & REQ_SANITIZE) != (next->cmd_flags & REQ_SANITIZE))
+		return 0;
+
+	/*
 	 * not contiguous
 	 */
 	if (blk_rq_pos(req) + blk_rq_sectors(req) != blk_rq_pos(next))
diff --git a/block/elevator.c b/block/elevator.c
index b0b38ce..78a14b5 100644
--- a/block/elevator.c
+++ b/block/elevator.c
@@ -89,6 +89,12 @@
 		return 0;
 
 	/*
+	 * Don't merge sanitize requests
+	 */
+	if ((bio->bi_rw & REQ_SANITIZE) != (rq->bio->bi_rw & REQ_SANITIZE))
+		return 0;
+
+	/*
 	 * different data direction or already started, don't merge
 	 */
 	if (bio_data_dir(bio) != rq_data_dir(rq))
@@ -657,7 +663,7 @@
 	if (rq->cmd_flags & REQ_SOFTBARRIER) {
 		/* barriers are scheduling boundary, update end_sector */
 		if (rq->cmd_type == REQ_TYPE_FS ||
-		    (rq->cmd_flags & REQ_DISCARD)) {
+		    (rq->cmd_flags & (REQ_DISCARD | REQ_SANITIZE))) {
 			q->end_sector = rq_end_sector(rq);
 			q->boundary_rq = rq;
 		}
diff --git a/block/ioctl.c b/block/ioctl.c
index 1124cd2..dbc103b 100644
--- a/block/ioctl.c
+++ b/block/ioctl.c
@@ -131,6 +131,11 @@
 	return blkdev_issue_discard(bdev, start, len, GFP_KERNEL, flags);
 }
 
+static int blk_ioctl_sanitize(struct block_device *bdev)
+{
+	return blkdev_issue_sanitize(bdev, GFP_KERNEL);
+}
+
 static int put_ushort(unsigned long arg, unsigned short val)
 {
 	return put_user(val, (unsigned short __user *)arg);
@@ -215,6 +220,10 @@
 		set_device_ro(bdev, n);
 		return 0;
 
+	case BLKSANITIZE:
+		ret = blk_ioctl_sanitize(bdev);
+		break;
+
 	case BLKDISCARD:
 	case BLKSECDISCARD: {
 		uint64_t range[2];
diff --git a/include/linux/blk_types.h b/include/linux/blk_types.h
index 6395692..47b1fe3 100644
--- a/include/linux/blk_types.h
+++ b/include/linux/blk_types.h
@@ -151,6 +151,7 @@
 	__REQ_IO_STAT,		/* account I/O stat */
 	__REQ_MIXED_MERGE,	/* merge of different types, fail separately */
 	__REQ_SECURE,		/* secure discard (used with __REQ_DISCARD) */
+	__REQ_SANITIZE,		/* sanitize */
 	__REQ_NR_BITS,		/* stops here */
 };
 
@@ -161,13 +162,14 @@
 #define REQ_SYNC		(1 << __REQ_SYNC)
 #define REQ_META		(1 << __REQ_META)
 #define REQ_DISCARD		(1 << __REQ_DISCARD)
+#define REQ_SANITIZE		(1 << __REQ_SANITIZE)
 #define REQ_NOIDLE		(1 << __REQ_NOIDLE)
 
 #define REQ_FAILFAST_MASK \
 	(REQ_FAILFAST_DEV | REQ_FAILFAST_TRANSPORT | REQ_FAILFAST_DRIVER)
 #define REQ_COMMON_MASK \
 	(REQ_WRITE | REQ_FAILFAST_MASK | REQ_SYNC | REQ_META | REQ_DISCARD | \
-	 REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE)
+	 REQ_NOIDLE | REQ_FLUSH | REQ_FUA | REQ_SECURE | REQ_SANITIZE)
 #define REQ_CLONE_MASK		REQ_COMMON_MASK
 
 #define REQ_RAHEAD		(1 << __REQ_RAHEAD)
diff --git a/include/linux/blkdev.h b/include/linux/blkdev.h
index 1b13021..4dc4b3e 100644
--- a/include/linux/blkdev.h
+++ b/include/linux/blkdev.h
@@ -403,6 +403,7 @@
 #define QUEUE_FLAG_NOXMERGES   15	/* No extended merges */
 #define QUEUE_FLAG_ADD_RANDOM  16	/* Contributes to random pool */
 #define QUEUE_FLAG_SECDISCARD  17	/* supports SECDISCARD */
+#define QUEUE_FLAG_SANITIZE    19	/* supports SANITIZE */
 
 #define QUEUE_FLAG_DEFAULT	((1 << QUEUE_FLAG_IO_STAT) |		\
 				 (1 << QUEUE_FLAG_STACKABLE)	|	\
@@ -485,6 +486,7 @@
 #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_sanitize(q)	test_bit(QUEUE_FLAG_SANITIZE, &(q)->queue_flags)
 #define blk_queue_secdiscard(q)	(blk_queue_discard(q) && \
 	test_bit(QUEUE_FLAG_SECDISCARD, &(q)->queue_flags))
 
@@ -922,6 +924,7 @@
 extern int blkdev_issue_flush(struct block_device *, gfp_t, sector_t *);
 extern int blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		sector_t nr_sects, gfp_t gfp_mask, unsigned long flags);
+extern int blkdev_issue_sanitize(struct block_device *bdev, gfp_t gfp_mask);
 extern int blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 			sector_t nr_sects, gfp_t gfp_mask);
 static inline int sb_issue_discard(struct super_block *sb, sector_t block,
diff --git a/include/linux/fs.h b/include/linux/fs.h
index 35e4edf..1c91125 100644
--- a/include/linux/fs.h
+++ b/include/linux/fs.h
@@ -317,6 +317,7 @@
 #define BLKPBSZGET _IO(0x12,123)
 #define BLKDISCARDZEROES _IO(0x12,124)
 #define BLKSECDISCARD _IO(0x12,125)
+#define BLKSANITIZE _IO(0x12, 126)
 
 #define BMAP_IOCTL 1		/* obsolete - kept for compatibility */
 #define FIBMAP	   _IO(0x00,1)	/* bmap access */
diff --git a/kernel/trace/blktrace.c b/kernel/trace/blktrace.c
index 6957aa2..fa1d639 100644
--- a/kernel/trace/blktrace.c
+++ b/kernel/trace/blktrace.c
@@ -1792,6 +1792,8 @@
 		rwbs[i++] = 'W';
 	else if (rw & REQ_DISCARD)
 		rwbs[i++] = 'D';
+	else if (rw & REQ_SANITIZE)
+		rwbs[i++] = 'Z';
 	else if (bytes)
 		rwbs[i++] = 'R';
 	else