On 8/29/24 15:45, Miklos Szeredi wrote:
> On Thu, 29 Aug 2024 at 15:07, Bernd Schubert <bschubert@xxxxxxx> wrote:
>
>> Sorry forgot, additionally we (at DDN) will probably also need aligned
>> setxattr.
>
> Hmm, that's trickier.
>
> I'm thinking that with the uring interface it would be possible to
> e.g. give a separate buffer for the header and the payload. But
> that's just handwaving, would need to flesh out the details.
New fuse-uring rfc should go out today, but I plan to do another change
after that to get the buffer layout closer (or hopefully exactly)
to the existing buffer layout to avoid differences.
Current uring has fuse_in_header/fuse_out_header separated from the
request, but then there is still the per request header.
We could change it, also for non-uring, but it would be a rather
big change. At least for userspace. My personal preference would
be something like
#define IN_OUT_HEADER_SZ 128
#define REQ_HEADER_SZ 256
struct fuse_header
{
union {
struct fuse_in_header in;
struct fuse_out_header out;
uint8_t in_out_header[IN_OUT_HEADER_SZ];
};
union {
struct fuse_init_in init_in;
struct fuse_init_out init_out;
struct cuse_init_in cuse_in;
struct cuse_init_out cuse_out;
...
uint8_t req_header[REQ_HEADER_SZ];
}
}
And then actual data would follow after. Would solve
changes in struct sizes, up to IN_OUT_HEADER_SZ and
REQ_HEADER_SZ, but rather cumbersome.
Thanks,
Bernd
