[PATCH 4.19 020/361] block: make sure writesame bio is aligned with logical block size

[Greg Kroah-Hartman]

4.19-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Ming Lei <ming.lei@xxxxxxxxxx>

commit 34ffec60b27aa81d04e274e71e4c6ef740f75fc7 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: stable@xxxxxxxxxxxxxxx
Cc: Mike Snitzer <snitzer@xxxxxxxxxx>
Cc: Christoph Hellwig <hch@xxxxxx>
Cc: Xiao Ni <xni@xxxxxxxxxx>
Cc: Mariusz Dabrowski <mariusz.dabrowski@xxxxxxxxx>
Fixes: b49a0871be31a745b2ef ("block: remove split code in blkdev_issue_{discard,write_same}")
Tested-by: Rui Salvaterra <rsalvaterra@xxxxxxxxx>
Signed-off-by: Ming Lei <ming.lei@xxxxxxxxxx>
Signed-off-by: Jens Axboe <axboe@xxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>

---
 block/blk-lib.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -161,7 +161,7 @@ static int __blkdev_issue_write_same(str
 		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);