From: Gabriel de Perthuis <g2p.code@gmail.com>
Date: Mon, 30 Nov 2015 02:40:23 +0000 (-0800)
Subject: bcache: allows use of register in udev to avoid "device_busy" error.
X-Git-Tag: v4.1.12-92~150^2~315
X-Git-Url: https://www.infradead.org/git/?a=commitdiff_plain;h=01a3218cde197e2f8659c86ab989973b87da0c89;p=users%2Fjedix%2Flinux-maple.git

bcache: allows use of register in udev to avoid "device_busy" error.

Orabug: 23330612

[ Upstream commit d7076f21629f8f329bca4a44dc408d94670f49e2 ]

Allows to use register, not register_quiet in udev to avoid "device_busy" error.
The initial patch proposed at https://lkml.org/lkml/2013/8/26/549 by Gabriel de Perthuis
<g2p.code@gmail.com> does not unlock the mutex and hangs the kernel.

See http://thread.gmane.org/gmane.linux.kernel.bcache.devel/2594 for the discussion.

Cc: Denis Bychkov <manover@gmail.com>
Cc: Kent Overstreet <kent.overstreet@gmail.com>
Cc: Eric Wheeler <bcache@linux.ewheeler.net>
Cc: Gabriel de Perthuis <g2p.code@gmail.com>
Cc: stable@vger.kernel.org

Signed-off-by: Jens Axboe <axboe@fb.com>
Signed-off-by: Sasha Levin <sasha.levin@oracle.com>
(cherry picked from commit d5402134c27d66e83295ae2961772b89bc6a50bc)

Signed-off-by: Dan Duval <dan.duval@oracle.com>
---

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 53f15126182a..42522c8f13c6 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1972,6 +1972,8 @@ static ssize_t register_bcache(struct kobject *k, struct kobj_attribute *attr,
 			else
 				err = "device busy";
 			mutex_unlock(&bch_register_lock);
+			if (attr == &ksysfs_register_quiet)
+				goto out;
 		}
 		goto err;
 	}
@@ -2010,8 +2012,7 @@ out:
 err_close:
 	blkdev_put(bdev, FMODE_READ|FMODE_WRITE|FMODE_EXCL);
 err:
-	if (attr != &ksysfs_register_quiet)
-		pr_info("error opening %s: %s", path, err);
+	pr_info("error opening %s: %s", path, err);
 	ret = -EINVAL;
 	goto out;
 }