Re: file metadata via fs API (was: [GIT PULL] Filesystem Information)

On Wed, Aug 12, 2020 at 8:53 PM Jeffrey E Altman [off-list ref] wrote:

For the AFS community, fsinfo offers a method of exposing some server
and volume properties that are obtained via "path ioctls" in OpenAFS and
AuriStorFS.  Some example of properties that might be exposed include
answers to questions such as:

Note that several of the questions you ask aren't necessarily
mount-related at all.

Doing it by mount ends up being completely the wrong thing.

For example, at a minimum, these guys may well be per-directory (or
even possibly per-file):

 * where is a mounted volume hosted? which fileservers, named by uuid
 * what is the block size? 1K, 4K, ...
 * are directories just-send-8, case-sensitive, case-preserving, or
   case-insensitive?
 * if not just-send-8, what character set is used?
 * if Unicode, what normalization rules? etc.
 * what volume security policy (authn, integ, priv) is assigned, if any?
 * what is the replication policy, if any?
 * what is the volume encryption policy, if any?

and trying to solve this with some kind of "mount info" is pure garbage.

Honestly, I really think you may want an extended [f]statfs(), not
some mount tracking.

                 Linus