Re: [PATCH v3 18/21] fuse: Implement multi-threading

[Hanna Czenczek <hreitz@redhat.com>]

On 23.10.25 13:47, Kevin Wolf wrote:
> Am 01.07.2025 um 13:44 hat Hanna Czenczek geschrieben:
>> FUSE allows creating multiple request queues by "cloning" /dev/fuse FDs
>> (via open("/dev/fuse") + ioctl(FUSE_DEV_IOC_CLONE)).
>>
>> We can use this to implement multi-threading.
>>
>> For configuration, we don't need any more information beyond the simple
>> array provided by the core block export interface: The FUSE kernel
>> driver feeds these FDs in a round-robin fashion, so all of them are
>> equivalent and we want to have exactly one per thread.
>> [...]
>> @@ -451,6 +553,16 @@ static void fuse_export_delete(BlockExport *blk_exp)
>>   {
>>       FuseExport *exp = container_of(blk_exp, FuseExport, common);
>>   
>> +    for (int i = 0; i < exp->num_queues; i++) {
>> +        FuseQueue *q = &exp->queues[i];
>> +
>> +        /* Queue 0's FD belongs to the FUSE session */
>> +        if (i > 0 && q->fuse_fd >= 0) {
> Why not start the loop with i = 1 instead of starting at 0 and then not
> doing anything in the first iteration?

Er, right.

> (I love the >= 0, running FUSE over stdin must be fun. :-))

Wouldn’t be too surprised if someone already did that…

Hanna

>> +            close(q->fuse_fd);
>> +        }
>> +    }
>> +    g_free(exp->queues);
>> +
>>       if (exp->fuse_session) {
>>           if (exp->mounted) {
>>               fuse_session_unmount(exp->fuse_session);
> Kevin
>