On 04/05/2020 18:25, Jens Axboe wrote:
> On 5/4/20 9:19 AM, Gustavo A. R. Silva wrote:
>> In case force_nonblock happens to be true, the function returns
>> at:
>>
>> 2779 if (force_nonblock)
>> 2780 return -EAGAIN;
>>
>> before reaching this line of code. So, the null check on force_nonblock
>> at 2785, is never actually being executed.
>>
>> Addresses-Coverity-ID: 1492838 ("Logically dead code")
>> Fixes: 2fb3e82284fc ("io_uring: punt splice async because of inode mutex")
>> Signed-off-by: Gustavo A. R. Silva <gustavo@xxxxxxxxxxxxxx>
>> ---
>> fs/io_uring.c | 2 +-
>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>
>> diff --git a/fs/io_uring.c b/fs/io_uring.c
>> index e5dfbbd2aa34..4b1efb062f7f 100644
>> --- a/fs/io_uring.c
>> +++ b/fs/io_uring.c
>> @@ -2782,7 +2782,7 @@ static int io_splice(struct io_kiocb *req, bool force_nonblock)
>> poff_in = (sp->off_in == -1) ? NULL : &sp->off_in;
>> poff_out = (sp->off_out == -1) ? NULL : &sp->off_out;
>> ret = do_splice(in, poff_in, out, poff_out, sp->len, flags);
>> - if (force_nonblock && ret == -EAGAIN)
>> + if (ret == -EAGAIN)
>> return -EAGAIN;
>
> This isn't right, it should just remove the two lines completely. But
> also see:
Oh, right, it will ignore O_NONBLOCK and be resubmitted, as going through
io_wq_submit_work(). I need to be more attentive.
>
> https://lore.kernel.org/io-uring/529ea928-88a6-2cbe-ba8c-72b4c68cc7e8@xxxxxxxxx/T/#u
>
--
Pavel Begunkov
