Re: [PATCH v2] bcache: release dc->writeback_lock properly in bch_writeback_thread()
From: Coly Li <hidden>
Date: 2018-08-22 18:07:55
Also in:
linux-block, stable
On 2018/8/23 2:02 AM, Coly Li wrote:
From: Shan Hai <redacted> 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 <redacted> Signed-off-by: Coly Li <redacted> Tested-by: Shenghui Wang <redacted> Cc: stable@vger.kernel.org #4.17+ --- Changelog: v2: add Fixes tag by Coly Li. v1: initial patch from Shan Hai.
Hi Jens, Please pick this patch for your next pull request. The change from Shan Hai fixes a real issue which is reported and lately verified by Shenghui Wang. Thanks in advance. Coly Li
quoted hunk ↗ jump to hunk
drivers/md/bcache/writeback.c | 4 +++- 1 file changed, 3 insertions(+), 1 deletion(-)diff --git a/drivers/md/bcache/writeback.c b/drivers/md/bcache/writeback.c index 6be05bd7ca67..08c3a9f9676c 100644 --- a/drivers/md/bcache/writeback.c +++ b/drivers/md/bcache/writeback.c@@ -685,8 +685,10 @@ static int bch_writeback_thread(void *arg) * 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);