From 34ffec60b27aa81d04e274e71e4c6ef740f75fc7 Mon Sep 17 00:00:00 2001
From: Ming Lei <ming.lei@redhat.com>
Date: Mon, 29 Oct 2018 20:57:19 +0800
Subject: [PATCH] block: make sure writesame bio is aligned with logical block
 size
Git-commit: 34ffec60b27aa81d04e274e71e4c6ef740f75fc7
Patch-mainline: v4.20-rc2
References: git-fixes

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@vger.kernel.org
Cc: Mike Snitzer <snitzer@redhat.com>
Cc: Christoph Hellwig <hch@lst.de>
Cc: Xiao Ni <xni@redhat.com>
Cc: Mariusz Dabrowski <mariusz.dabrowski@intel.com>
Fixes: b49a0871be31a745b2ef ("block: remove split code in blkdev_issue_{discard,write_same}")
Tested-by: Rui Salvaterra <rsalvaterra@gmail.com>
Signed-off-by: Ming Lei <ming.lei@redhat.com>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>
---
 block/blk-lib.c |    2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -163,7 +163,7 @@ 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);