[LSF/MM/BPF TOPIC] statx attributes

[Steve French]

On Thu, Mar 7, 2024 at 11:45 AM Kent Overstreet
<kent.overstreet at linux.dev> wrote:
>
> On Thu, Mar 07, 2024 at 10:37:13AM -0600, Steve French wrote:
> > > Which API is used in other OS to query the offline bit?
> > > Do they use SMB specific API, as Windows does?
> >
> > No it is not smb specific - a local fs can also report this.  It is
> > included in the attribute bits for files and directories, it also
> > includes a few additional bits that are used by HSM software on local
> > drives (e.g. FILE_ATTRIBUTE_PINNED when the file may not be taken
> > offline by HSM software)
> > ATTRIBUTE_HIDDEN
> > ATTRIBUTE_SYSTEM
> > ATTRIBUTE_DIRECTORY
> > ATTRIGBUTE_ARCHIVE
> > ATTRIBUTE_TEMPORARY
> > ATTRIBUTE_SPARSE_FILE
> > ATTRIBUTE_REPARE_POINT
> > ATTRIBUTE_COMPRESSED
> > ATTRIBUTE_NOT_CONTENT_INDEXED
> > ATTRIBUTE_ENCRYPTED
> > ATTRIBUTE_OFFLINE
>
> we've already got some of these as inode flags available with the
> getflags ioctl (compressed, also perhaps encrypted?) - but statx does
> seem a better place for them.
>
> statx can also report when they're supported, which does make sense for
> these.
>
> ATTRIBUTE_DIRECTORY, though?
>
> we also need to try to define the semantics for these and not just dump
> them in as just a bunch of identifiers if we want them to be used by
> other things - and we do.

They are all pretty clearly defined, but many are already in Linux,
and a few are not relevant (e.g. ATTRIBUTE_DIRECTORY is handled in
mode bits).  I suspect that Macs have equivalents of most of these
too.


-- 
Thanks,

Steve