4.4-stable review patch. If anyone has any objections, please let me know.
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From: Shan Hai shan.hai@oracle.com
commit 3943b040f11ed0cc6d4585fd286a623ca8634547 upstream.
The writeback thread would exit with a lock held when the cache device is detached via sysfs interface, fix it by releasing the held lock before exiting the while-loop.
Fixes: fadd94e05c02 (bcache: quit dc->writeback_thread when BCACHE_DEV_DETACHING is set) Signed-off-by: Shan Hai shan.hai@oracle.com Signed-off-by: Coly Li colyli@suse.de Tested-by: Shenghui Wang shhuiw@foxmail.com Cc: stable@vger.kernel.org #4.17+ Signed-off-by: Jens Axboe axboe@kernel.dk Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org
--- drivers/md/bcache/writeback.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)
--- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c @@ -462,8 +462,10 @@ static int bch_writeback_thread(void *ar * data on cache. BCACHE_DEV_DETACHING flag is set in * bch_cached_dev_detach(). */ - if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) + if (test_bit(BCACHE_DEV_DETACHING, &dc->disk.flags)) { + up_write(&dc->writeback_lock); break; + } }
up_write(&dc->writeback_lock);