Re: file handle in statx (was: Re: How to cope with subvolumes and snapshots on muti-user systems?)

Miklos Szeredi
2023-12-12T16:30:36Z

On Tue, 12 Dec 2023 at 17:08, Kent Overstreet <kent.overstreet@linux.dev> wrote:

> In short, STATX_ATTR_INUM_NOT_UNIQUE is required to tell userspace when
> they _must_ do the new thing if they care about correctness; it provides
> a way to tell userspace what guarantees we're able to provide.

That flag would not help with improving userspace software.

What would help, if said software started using a unique identifier.
We already seem to have a unique ID in the form of file handles,
though some exotic filesystems might allow more than one fh to refer
to the same inode, so this still needs some looking into.

The big problem is that we can't do a lot about existing software, and
must keep trying to keep st_ino unique for the foreseeable future.

Thanks,
Miklos