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

[Miklos Szeredi]

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).

Thanks,
Miklos