Re: [PATCH v2 0/2] fuse: add timeout option for requests

[Bernd Schubert <bernd.schubert@fastmail.fm>]

On 8/6/24 18:23, Joanne Koong wrote:

>>
>> This is very interesting. These logs (and the ones above with the
>> lxcfs server running concurrently) are showing that the read request
>> was freed but not through the do_fuse_request_end path. It's weird
>> that fuse_simple_request reached fuse_put_request without
>> do_fuse_request_end having been called (which is the only place where
>> FR_FINISHED gets set and wakes up the wait events in
>> request_wait_answer).
>>
>> I'll take a deeper look tomorrow and try to make more sense of it.
> 
> Finally realized what's happening!
> When we kill the cat program, if the request hasn't been sent out to
> userspace yet when the fatal signal interrupts the
> wait_event_interruptible and wait_event_killable in
> request_wait_answer(), this will clean up the request manually (not
> through the fuse_request_end() path), which doesn't delete the timer.
> 
> I'll fix this for v3.
> 
> Thank you for surfacing this and it would be much appreciated if you
> could test out v3 when it's submitted to make sure.

It is still just a suggestion, but if the timer would have its own ref,
any oversight of another fuse_put_request wouldn't be fatal.


Thanks,
Bernd