Re: [fuse-devel] cached file size not invalidated after release() in old Fuse version (seen with 2.7.2)

[Michael B. <mic...@go...>]

Hi,

>> We are using pseudo files internally to communicate between a userspace
>> tool and our filesystem. Our userspace tool does communicate in the
>> following way with our file system:
>>
>> - creat() pseudo file on file system
>> - Fuse implicitly calls fgetattr() on the pseudo file (size of 0 returned)
>> - write() the request to pseudo file
>>
>> - close() and open() pseudo file to avoid cache problems
>>
>> - Fuse implicitly calls fgetattr() on the pseudo file (actual size of
>> the response returned)
>> - read() result from pseudo file
>> - close() pseudo file
>
> Have you considered to communicate using setxattr() and getxattr()
> instead? It seems to me that this would be much easier.

If I remember correctly, we decided to use virtual files to have a 
plattform-independ solution which will also work on a later Dokan port.

The approach itself works very well except for the stated issue in older 
Fuse versions. Therefore I wanted to know if this a known bug or I did 
miss a Fuse option which does prevent this.

Executing an additional stat() on the virtual file is an acceptable fix 
for me. However, I was wondering if there are other suggestions to work 
around it.

Best,
Michael