Re: [RFC PATCH] getting misc stats/attributes via xattr API

[Amir Goldstein]

On Tue, May 3, 2022 at 6:04 PM Miklos Szeredi <miklos@xxxxxxxxxx> wrote:
>
> On Tue, 3 May 2022 at 16:53, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote:
> >
> > On Tue, May 03, 2022 at 05:39:46PM +0300, Amir Goldstein wrote:
>
> > > It should be noted that while this API mandates text keys,
> > > it does not mandate text values, so for example, sb iostats could be
> > > exported as text or as binary struct, or as individual text/binary records or
> > > all of the above.
> >
> > Ugh, no, that would be a total mess.  Don't go exporting random binary
> > structs depending on the file, that's going to be completely
> > unmaintainable.  As it is, this is going to be hard enough with random
> > text fields.
> >
> > As for this format, it needs to be required to be documented in
> > Documentation/ABI/ for each entry and key type so that we have a chance
> > of knowing what is going on and tracking how things are working and
> > validating stuff.
>
> My preference would be a single text value for each key.
>
> Contents of ":mnt:info" contradicts that, but mountinfo has a long
> established, well documented format, and nothing prevents exporting
> individual attributes with separate names as well (the getvalues(2)
> patch did exactly that).
>

Right, the fun is that ":mnt:info" and ":mnt:info:" can co-exist.

Thanks,
Amir.