Re: [PATCH] io_uring: ensure REQ_F_ISREG is set async offload

[Jens Axboe <axboe@kernel.dk>]

On 7/21/22 5:43 PM, Yin Fengwei wrote:
> 
> On 7/21/2022 11:11 PM, Jens Axboe wrote:
>> If we're offloading requests directly to io-wq because IOSQE_ASYNC was
>> set in the sqe, we can miss hashing writes appropriately because we
>> haven't set REQ_F_ISREG yet. This can cause a performance regression
>> with buffered writes, as io-wq then no longer correctly serializes writes
>> to that file.
>>
>> Ensure that we set the flags in io_prep_async_work(), which will cause
>> the io-wq work item to be hashed appropriately.
>>
>> Fixes: 584b0180f0f4 ("io_uring: move read/write file prep state into actual opcode handler")
>> Link: https://lore.kernel.org/io-uring/20220608080054.GB22428@xsang-OptiPlex-9020/
>> Reported-and-tested-by: Yin Fengwei <fengwei.yin@intel.com>
> This issue is reported by (from the original report):
> 
> If you fix the issue, kindly add following tag
> Reported-by: kernel test robot <oliver.sang@intel.com>

Sorry, I missed that in the original. I'll be rebasing this branch this
weekend anyway, I'll try and remember to make the edit.

-- 
Jens Axboe