From 688892b3bc05e25da94866e32210e5f503f16f69 Mon Sep 17 00:00:00 2001
From: Tang Junhui <tang.junhui@zte.com.cn>
Date: Sun, 18 Mar 2018 17:36:20 -0700
Subject: [PATCH] bcache: fix incorrect sysfs output value of strip size
Git-commit: 688892b3bc05e25da94866e32210e5f503f16f69
Patch-mainline: v4.17-rc1
References: bsc#1093023

Stripe size is shown as zero when no strip in back end device:
[root@ceph132 ~]# cat /sys/block/sdd/bcache/stripe_size
0.0k

Actually it should be 1T Bytes (1 << 31 sectors), but in sysfs
interface, stripe_size was changed from sectors to bytes, and move
9 bits left, so the 32 bits variable overflows.

This patch change the variable to a 64 bits type before moving bits.

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Coly Li <colyli@suse.de>

---
 drivers/md/bcache/sysfs.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/drivers/md/bcache/sysfs.c b/drivers/md/bcache/sysfs.c
index 414129f7c49f..8c3fd05db87a 100644
--- a/drivers/md/bcache/sysfs.c
+++ b/drivers/md/bcache/sysfs.c
@@ -181,7 +181,7 @@ SHOW(__bch_cached_dev)
 	sysfs_hprint(dirty_data,
 		     bcache_dev_sectors_dirty(&dc->disk) << 9);
 
-	sysfs_hprint(stripe_size,	dc->disk.stripe_size << 9);
+	sysfs_hprint(stripe_size,	 ((uint64_t)dc->disk.stripe_size) << 9);
 	var_printf(partial_stripes_expensive,	"%u");
 
 	var_hprint(sequential_cutoff);
-- 
2.16.3