Re: [PATCHSET v2 0/6] io_uring: add support for open/close

Stefan Metzmacher
2020-01-20T12:15:42Z

[-- Attachment #1.1: Type: text/plain, Size: 977 bytes --]

Hi Jens,

>> Thanks!
>>
>> Another great feature would the possibility to make use of the
>> generated fd in the following request.
>>
>> This is a feature that's also available in the SMB3 protocol
>> called compound related requests.
>>
>> The client can compound a chain with open, getinfo, read, close
>> getinfo, read and close get an file handle of -1 and implicitly
>> get the fd generated/used in the previous request.
>
> Right, the "plan" there is to utilize BPF to make this programmable.
> We really need something more expressive to be able to pass information
> between SQEs that are linked, or even to decide which link to run
> depending on the outcome of the parent.
>
> There's a lot of potential there!

I guess so, but I don't yet understand how BPF works in real life.

Is it possible to do that as normal user without special privileges?

My naive way would be using some flags and get res and pass fd by reference.

metze

[-- Attachment #2: OpenPGP digital signature --]
[-- Type: application/pgp-signature, Size: 833 bytes --]