From 14657efd3ad918f6779100e1047ea60d97a0d667 Mon Sep 17 00:00:00 2001
From: Ming Lei
Date: Mon, 29 Oct 2018 20:57:17 +0800
Subject: block: make sure discard bio is aligned with logical block size

commit 1adfc5e4136f5967d591c399aff95b3b035f16b7 upstream.

Obviously the created discard bio has to be aligned with logical block size.

This patch introduces the helper of bio_allowed_max_sectors() for
this purpose.

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: 744889b7cbb56a6 ("block: don't deal with discard limit in blkdev_issue_discard()")
Fixes: a22c4d7e34402cc ("block: re-add discard_granularity and alignment checks")
Reported-by: Rui Salvaterra <rsalvaterra@gmail.com>
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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 block/blk-lib.c | 3 +--
 1 file changed, 1 insertion(+), 2 deletions(-)

(limited to 'block/blk-lib.c')

diff --git a/block/blk-lib.c b/block/blk-lib.c
index bbd44666f2b5..aa62201601c5 100644
--- a/block/blk-lib.c
+++ b/block/blk-lib.c
@@ -58,8 +58,7 @@ int __blkdev_issue_discard(struct block_device *bdev, sector_t sector,
 
 		if (!req_sects)
 			goto fail;
-		if (req_sects > UINT_MAX >> 9)
-			req_sects = UINT_MAX >> 9;
+		req_sects = min(req_sects, bio_allowed_max_sectors(q));
 
 		end_sect = sector + req_sects;
 
-- 
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