[PATCH zesty] UBUNTU: SAUCE: bcache: Fix bcache device names

[Stefan Bader]

I have sent this to upstream (got an ack already) but might be good
to carry as SAUCE until it tickles back.

-Stefan

>From 4a5ec18f2bec04cebb0cd5f7ab2a2999b86b7de5 Mon Sep 17 00:00:00 2001
From: Stefan Bader <stefan.bader at canonical.com>
Date: Wed, 1 Mar 2017 11:28:07 +0100
Subject: [PATCH] UBUNTU: SAUCE: bcache: Fix bcache device names

When adding partition support to bcache, the name assignment was not
updated, resulting in numbers jumping (bcache0, bcache16, bcache32...).
Fix this by taking BCACHE_MINORS into account when assigning the disk
name.

BugLink: https://bugs.launchpad.net/bugs/1667078

Fixes: b8c0d91 (bcache: partition support: add 16 minors per bcacheN device)
Cc: <stable at vger.kernel.org> # v4.10
Signed-off-by: Stefan Bader <stefan.bader at canonical.com>
---
 drivers/md/bcache/super.c | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index fd66c7d..1809606 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -793,7 +793,8 @@ static int bcache_device_init(struct bcache_device *d, unsigned block_size,
 	}
 
 	set_capacity(d->disk, sectors);
-	snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i", minor);
+	snprintf(d->disk->disk_name, DISK_NAME_LEN, "bcache%i",
+		 minor / BCACHE_MINORS);
 
 	d->disk->major		= bcache_major;
 	d->disk->first_minor	= minor;
-- 
2.7.4