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

[David Wei <dw@davidwei.uk>]

On 2024-10-15 17:05, Bernd Schubert wrote:
[...]
> 
> The corresponding libfuse patches are on my uring branch,
> but need cleanup for submission - will happen during the next
> days.
> https://github.com/bsbernd/libfuse/tree/uring
> 
> Testing with that libfuse branch is possible by running something
> like:
> 
> example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \
> --uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \
> /scratch/source /scratch/dest
> 
> With the --debug-fuse option one should see CQE in the request type,
> if requests are received via io-uring:
> 
> cqe unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 16, pid: 7060
>     unique: 4, result=104
> 
> Without the --uring option "cqe" is replaced by the default "dev"
> 
> dev unique: 4, opcode: GETATTR (3), nodeid: 1, insize: 56, pid: 7117
>    unique: 4, success, outsize: 120

Hi Bernd, I applied this patchset to io_uring-6.12 branch with some
minor conflicts. I'm running the following command:

$ sudo ./build/example/passthrough_hp -o allow_other --debug-fuse --nopassthrough \
--uring --uring-per-core-queue --uring-fg-depth=1 --uring-bg-depth=1 \
/home/vmuser/scratch/source /home/vmuser/scratch/dest
FUSE library version: 3.17.0
Creating ring per-core-queue=1 sync-depth=1 async-depth=1 arglen=1052672
dev unique: 2, opcode: INIT (26), nodeid: 0, insize: 104, pid: 0
INIT: 7.40
flags=0x73fffffb
max_readahead=0x00020000
   INIT: 7.40
   flags=0x4041f429
   max_readahead=0x00020000
   max_write=0x00100000
   max_background=0
   congestion_threshold=0
   time_gran=1
   unique: 2, success, outsize: 80

I created the source and dest folders which are both empty.

I see the following in dmesg:

[ 2453.197510] uring is disabled
[ 2453.198525] uring is disabled
[ 2453.198749] uring is disabled
...

If I then try to list the directory /home/vmuser/scratch:

$ ls -l /home/vmuser/scratch
ls: cannot access 'dest': Software caused connection abort

And passthrough_hp terminates.

My kconfig:

CONFIG_FUSE_FS=m
CONFIG_FUSE_PASSTHROUGH=y
CONFIG_FUSE_IO_URING=y

I'll look into it next week but, do you see anything obviously wrong?