bcache: stop writeback thread after detaching
authorTang Junhui <tang.junhui@zte.com.cn>
Mon, 8 Jan 2018 20:21:19 +0000 (12:21 -0800)
committerJens Axboe <axboe@kernel.dk>
Mon, 8 Jan 2018 20:29:00 +0000 (13:29 -0700)
commit8d29c4426b9f8afaccf28de414fde8a722b35fdf
treec50ce27af4c09ec9d3a66c2a197b2d4378e325a2
parentb221fc130c49c50f4c2250d22e873420765a9fa2
bcache: stop writeback thread after detaching

Currently, when a cached device detaching from cache, writeback thread is
not stopped, and writeback_rate_update work is not canceled. For example,
after the following command:
echo 1 >/sys/block/sdb/bcache/detach
you can still see the writeback thread. Then you attach the device to the
cache again, bcache will create another writeback thread, for example,
after below command:
echo  ba0fb5cd-658a-4533-9806-6ce166d883b9 > /sys/block/sdb/bcache/attach
then you will see 2 writeback threads.
This patch stops writeback thread and cancels writeback_rate_update work
when cached device detaching from cache.

Compare with patch v1, this v2 patch moves code down into the register
lock for safety in case of any future changes as Coly and Mike suggested.

[edit by mlyle: commit log spelling/formatting]

Signed-off-by: Tang Junhui <tang.junhui@zte.com.cn>
Reviewed-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Michael Lyle <mlyle@lyle.org>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
drivers/md/bcache/super.c