[PATCH 3.13.y-ckt 041/136] bcache: allows use of register in udev to avoid "device_busy" error.

From: Kamal Mostafa
Date: Tue Feb 02 2016 - 13:54:20 EST


3.13.11-ckt34 -stable review patch. If anyone has any objections, please let me know.

---8<------------------------------------------------------------

From: Gabriel de Perthuis <g2p.code@xxxxxxxxx>

commit d7076f21629f8f329bca4a44dc408d94670f49e2 upstream.

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@xxxxxxxxx> 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@xxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Eric Wheeler <bcache@xxxxxxxxxxxxxxxxxx>
Cc: Gabriel de Perthuis <g2p.code@xxxxxxxxx>

Signed-off-by: Jens Axboe <axboe@xxxxxx>
Signed-off-by: Kamal Mostafa <kamal@xxxxxxxxxxxxx>
---
drivers/md/bcache/super.c | 5 +++--
1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/md/bcache/super.c b/drivers/md/bcache/super.c
index 0b937fb..ccc0133 100644
--- a/drivers/md/bcache/super.c
+++ b/drivers/md/bcache/super.c
@@ -1927,6 +1927,8 @@ 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;
}
@@ -1964,8 +1966,7 @@ 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;
}
--
1.9.1