Re: [PATCH RFC v4 00/15] fuse: fuse-over-io-uring

[Bernd Schubert <bschubert@ddn.com>]

On 11/4/24 09:24, Bernd Schubert wrote:
> Hi David,
> 
> On 10/23/24 00:10, David Wei wrote:
>> [You don't often get email from dw@davidwei.uk. Learn why this is important at https://aka.ms/LearnAboutSenderIdentification ]
>>
>> On 2024-10-15 17:05, Bernd Schubert wrote:
>>> RFCv1 and RFCv2 have been tested with multiple xfstest runs in a VM
>>> (32 cores) with a kernel that has several debug options
>>> enabled (like KASAN and MSAN). RFCv3 is not that well tested yet.
>>> O_DIRECT is currently not working well with /dev/fuse and
>>> also these patches, a patch has been submitted to fix that (although
>>> the approach is refused)
>>> https://www.spinics.net/lists/linux-fsdevel/msg280028.html
>>
>> Hi Bernd, I applied this patch and the associated libfuse patch at:
>>
>> https://github.com/bsbernd/libfuse/tree/aligned-writes
>>
>> I have a simple Python FUSE client that is still returning EINVAL for
>> write():
>>
>> with open(sys.argv[1], 'r+b') as f:
>>     mmapped_file = mmap.mmap(f.fileno(), 0)
>>     shm = shared_memory.SharedMemory(create=True, size=mmapped_file.size())
>>     shm.buf[:mmapped_file.size()] = mmapped_file[:]
>>     fd = os.open("/home/vmuser/scratch/dest/out", O_RDWR|O_CREAT|O_DIRECT)
>>     with open(fd, 'w+b') as f2:
>>         f2.write(bytes(shm.buf))
>>     mmapped_file.close()
>>     shm.unlink()
>>     shm.close()
>>
>> I'll keep looking at this but letting you know in case it's something
>> obvious again.
> 
> the 'aligned-writes' libfuse branch would need another kernel patch. Please
> hold on a little bit, I hope to send out a new version later today or
> tomorrow that separates headers from payload - alignment is guaranteed. 
> 

If you are very brave, you could try out this (sorry, still on 6.10)


https://github.com/bsbernd/linux/tree/fuse-uring-for-6.10-rfc5
https://github.com/bsbernd/libfuse/tree/uring


Right now #fuse-uring-for-6.10-rfc5 is rather similar to
fuse-uring-for-6.10-rfc4, with two additional patches to
separate headers from payload. The head commit, which
updates fuse-io-uring is going to be rebased into the
other commits tomorrow.

Also, I just noticed a tear down issue, when the daemon
is killed while IO is going on - busy inodes on sb shutdown.
Some fuse requests are probably not correctly released, I
guess that is also already present on rfcv4. Will look into
it in the morning.


Thanks,
Bernd