Re: [PATCH 0/3] vmsplice: make vmsplice a trivial wrapper for preadv2/pwritev2

[Val Packett]

Hi,

On 6/1/26 2:33 PM, Al Viro wrote:
> On Mon, Jun 01, 2026 at 10:17:23AM -0700, Linus Torvalds wrote:
>
> > TLDR: maybe we could ghet rid of "f_op->splice_read". *That* would be
> > a big simplification.
> FUSE might be interesting - fuse_dev_splice_read() and its ilk.
> Communications between the kernel and fuse server at least used to
> seriously want that, so that would be one place to look for unhappy
> userland...

speaking of fuse_dev_splice……_write actually, this series has broken 
xdg-document-portal!

https://github.com/flatpak/xdg-desktop-portal/issues/2026

Specifically what happens is that the EINVAL is returned due to oh.len 
!= nbytes:

fuse_dev_do_write: oh.len 16400 != nbytes 15526

(where 16400 == 16384 (read len) + 16, 15526 == 15510 (file len) + 16)

After reverting the series, there is no error because oh.len 
becomes 15526 too.


Thanks,
~val