Re: [PATCH 3/3] f2fs: prevent waiter encountering incorrect discard states

From: Chao Yu
Date: Sat Apr 01 2017 - 02:55:02 EST


Ping,

Any problem here?

Thanks,

On 2017/3/28 9:17, Chao Yu wrote:
> On 2017/3/28 7:56, Jaegeuk Kim wrote:
>> On 03/27, Chao Yu wrote:
>>> In f2fs_submit_discard_endio, we will wake up waiter before setting
>>> discard command states, so waiter may use incorrect states. Change
>>> the order between complete() and states setting to fix this issue.
>>>
>>> Signed-off-by: Chao Yu <yuchao0@xxxxxxxxxx>
>>> ---
>>> fs/f2fs/segment.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/fs/f2fs/segment.c b/fs/f2fs/segment.c
>>> index 57a81f9c8c14..9f9542c9fe47 100644
>>> --- a/fs/f2fs/segment.c
>>> +++ b/fs/f2fs/segment.c
>>> @@ -717,9 +717,9 @@ static void f2fs_submit_discard_endio(struct bio *bio)
>>> {
>>> struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
>>>
>>> - complete(&dc->wait);
>>> dc->error = bio->bi_error;
>>> dc->state = D_DONE;
>>> + complete(&dc->wait);
>>
>> If we set D_DONE first, the object can be released by __remove_discard_cmd()?
>
> Yes, I think so.
>
> Thanks,
>
>>
>> Thanks,
>>
>>> bio_put(bio);
>>> }
>>>
>>> --
>>> 2.8.2.295.g3f1c1d0
>>
>> .
>>