Re: [PATCH v2 4/6] fs: report per-mount io stats

On Mon, Feb 28, 2022 at 5:06 PM Miklos Szeredi <[email protected]> wrote:
>
> On Mon, 28 Feb 2022 at 12:39, Amir Goldstein <[email protected]> wrote:
> >
> > Show optional collected per-mount io stats in /proc/<pid>/mountstats
> > for filesystems that do not implement their own show_stats() method
> > and opted-in to generic per-mount stats with FS_MOUNT_STATS flag.
>
> This would allow some filesystems to report per-mount I/O stats, while
> leaving CIFS and NFS reporting a different set of per-sb stats.  This
> doesn't sound very clean.
>
> There was an effort to create saner and more efficient interfaces for
> per-mount info.  IMO this should be part of that effort instead of
> overloading the old interface.
>

That's fair, but actually, I have no much need for per-mount I/O stats
in overlayfs/fuse use cases, so I could amend the patches to collect and
show per-sb I/O stats.

Then, the generic show_stats() will not be "overloading the old interface".
Instead, it will be creating a common implementation to share among different
filesystems and using an existing vfs interface as it was intended.

Would you be willing to accept adding per-sb I/O stats to overlayfs
and/or fuse via /proc/<pid>/mountstats?

Thanks,
Amir.