block: make sure writesame bio is aligned with logical block size

commit 34ffec6 upstream.

Obviously the created writesame bio has to be aligned with logical block
size, and use bio_allowed_max_sectors() to retrieve this number.

Cc: [email protected]
Cc: Mike Snitzer <[email protected]>
Cc: Christoph Hellwig <[email protected]>
Cc: Xiao Ni <[email protected]>
Cc: Mariusz Dabrowski <[email protected]>
Fixes: b49a087 ("block: remove split code in blkdev_issue_{discard,write_same}")
Tested-by: Rui Salvaterra <[email protected]>
Signed-off-by: Ming Lei <[email protected]>
Signed-off-by: Jens Axboe <[email protected]>
Signed-off-by: Greg Kroah-Hartman <[email protected]>

Author: Ming Lei

block/blk-lib.c

@@ -161,7 +161,7 @@ static int __blkdev_issue_write_same(struct block_device *bdev, sector_t sector,
 		return -EOPNOTSUPP;
 
 	/* Ensure that max_write_same_sectors doesn't overflow bi_size */
-	max_write_same_sectors = UINT_MAX >> 9;
+	max_write_same_sectors = bio_allowed_max_sectors(q);
 
 	while (nr_sects) {
 		bio = next_bio(bio, 1, gfp_mask);