Re: [PATCH 1/1] io_uring: clean up io_uring_register_get_file()

[Jens Axboe <axboe@kernel.dk>]

On 1/16/25 6:09 AM, lizetao wrote:
> Hi,
> 
>> -----Original Message-----
>> From: Pavel Begunkov <asml.silence@gmail.com>
>> Sent: Thursday, January 16, 2025 10:53 AM
>> To: io-uring@vger.kernel.org
>> Cc: asml.silence@gmail.com
>> Subject: [PATCH 1/1] io_uring: clean up io_uring_register_get_file()
>>
>> Make it always reference the returned file. It's safer, especially with
>> unregistrations happening under it. And it makes the api cleaner with no
>> conditional clean ups by the caller.
>>
>> Signed-off-by: Pavel Begunkov <asml.silence@gmail.com>
>> ---
>>  io_uring/register.c | 6 ++++--
>>  io_uring/rsrc.c     | 4 ++--
>>  2 files changed, 6 insertions(+), 4 deletions(-)
>>
>> diff --git a/io_uring/register.c b/io_uring/register.c index
>> 5e48413706ac..a93c979c2f38 100644
>> --- a/io_uring/register.c
>> +++ b/io_uring/register.c
>> @@ -841,6 +841,8 @@ struct file *io_uring_register_get_file(unsigned int fd,
>> bool registered)
>>  			return ERR_PTR(-EINVAL);
>>  		fd = array_index_nospec(fd, IO_RINGFD_REG_MAX);
>>  		file = tctx->registered_rings[fd];
>> +		if (file)
>> +			get_file(file);
> 
> Should performance be a priority here?

Performance only really matters for high frequency invocations, of which
the register part is not. So no, should not matter at all.

-- 
Jens Axboe