Re: [PATCH v2] bcache: release dc->writeback_lock properly in bch_writeback_thread()

[Jens Axboe]

On 8/22/18 12:07 PM, Coly Li wrote:
> On 2018/8/23 2:02 AM, Coly Li wrote:
>> From: Shan Hai 
>>
>> 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 
>> Signed-off-by: Coly Li 
>> Tested-by: Shenghui Wang 
>> Cc: sta...@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.

Applied - but I fixed up the commit message. Please keep lines at
72 characters for git commits.

-- 
Jens Axboe

Re: [PATCH v2] bcache: release dc->writeback_lock properly in bch_writeback_thread()

[Coly Li]

On 2018/8/23 2:02 AM, Coly Li wrote:
> From: Shan Hai 
> 
> 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 
> Signed-off-by: Coly Li 
> Tested-by: Shenghui Wang 
> Cc: sta...@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

> 
>  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, >disk.flags))
> + if (test_bit(BCACHE_DEV_DETACHING, >disk.flags)) {
> + up_write(>writeback_lock);
>   break;
> + }
>   }
>  
>   up_write(>writeback_lock);
> 

[PATCH v2] bcache: release dc->writeback_lock properly in bch_writeback_thread()

[Coly Li]

From: Shan Hai 

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 
Signed-off-by: Coly Li 
Tested-by: Shenghui Wang 
Cc: sta...@vger.kernel.org #4.17+
---
Changelog:
v2: add Fixes tag by Coly Li.
v1: initial patch from Shan Hai.

 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, >disk.flags))
+   if (test_bit(BCACHE_DEV_DETACHING, >disk.flags)) {
+   up_write(>writeback_lock);
break;
+   }
}
 
up_write(>writeback_lock);
-- 
2.18.0