block: require write_same and discard requests align to logical block size

Make sure that the offset and length arguments that we're using to
construct WRITE SAME and DISCARD requests are actually aligned to the
logical block size.  Failure to do this causes other errors in other parts
of the block layer or the SCSI layer because disks don't support partial
logical block writes.

Link: http://lkml.kernel.org/r/147518379026.22791.4437508871355153928.stgit@birch.djwong.org
Signed-off-by: Darrick J. Wong <darrick.wong@oracle.com>
Reviewed-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Bart Van Assche <bart.vanassche@sandisk.com>
Reviewed-by: Martin K. Petersen <martin.petersen@oracle.com>
Reviewed-by: Hannes Reinecke <hare@suse.com>
Cc: Theodore Ts'o <tytso@mit.edu>
Cc: Mike Snitzer <snitzer@redhat.com> # tweaked header
Cc: Brian Foster <bfoster@redhat.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>

block/blk-lib.c

@@ -31,6 +31,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 	unsigned int granularity;
 	enum req_op op;
 	int alignment;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
@@ -50,6 +51,10 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 		op = REQ_OP_DISCARD;
 	}
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Zero-sector (unknown) and one-sector granularities are the same.  */
 	granularity = max(q->limits.discard_granularity >> 9, 1U);
 	alignment = (bdev_discard_alignment(bdev) >> 9) % granularity;
@@ -150,10 +155,15 @@ int blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 	unsigned int max_write_same_sectors;
 	struct bio *bio = NULL;
 	int ret = 0;
+	sector_t bs_mask;
 
 	if (!q)
 		return -ENXIO;
 
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
+
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
 	max_write_same_sectors = UINT_MAX >> 9;
 
@@ -202,6 +212,11 @@ static int __blkdev_issue_zeroout(struct block_device *bdev, sector_t sector,
 	int ret;
 	struct bio *bio = NULL;
 	unsigned int sz;
+	sector_t bs_mask;
+
+	bs_mask = (bdev_logical_block_size(bdev) >> 9) - 1;
+	if ((sector | nr_sects) & bs_mask)
+		return -EINVAL;
 
 	while (nr_sects != 0) {
 		bio = next_bio(bio, min(nr_sects, (sector_t)BIO_MAX_PAGES),