From 9b2fb8ad5ba1b528e2f2927898403b0df40fd09b Mon Sep 17 00:00:00 2001
From: Mike Snitzer <snitzer@redhat.com>
Date: Sat, 22 Apr 2017 17:22:09 -0400
Subject: block: fix blk_integrity_register to use template's interval_exp if
 not 0

commit 2859323e35ab5fc42f351fbda23ab544eaa85945 upstream.

When registering an integrity profile: if the template's interval_exp is
not 0 use it, otherwise use the ilog2() of logical block size of the
provided gendisk.

This fixes a long-standing DM linear target bug where it cannot pass
integrity data to the underlying device if its logical block size
conflicts with the underlying device's logical block size.

Reported-by: Mikulas Patocka <mpatocka@redhat.com>
Signed-off-by: Mike Snitzer <snitzer@redhat.com>
Acked-by: Martin K. Petersen <martin.petersen@oracle.com>
Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/block/blk-integrity.c b/block/blk-integrity.c
index 319f2e4..478f572 100644
--- a/block/blk-integrity.c
+++ b/block/blk-integrity.c
@@ -412,7 +412,8 @@ void blk_integrity_register(struct gendisk *disk, struct blk_integrity *template
 
 	bi->flags = BLK_INTEGRITY_VERIFY | BLK_INTEGRITY_GENERATE |
 		template->flags;
-	bi->interval_exp = ilog2(queue_logical_block_size(disk->queue));
+	bi->interval_exp = template->interval_exp ? :
+		ilog2(queue_logical_block_size(disk->queue));
 	bi->profile = template->profile ? template->profile : &nop_profile;
 	bi->tuple_size = template->tuple_size;
 	bi->tag_size = template->tag_size;
-- 
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