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From: David Howells on 19 Jul 2010 10:20
Christoph Hellwig <hch(a)infradead.org> wrote:

> special is not a very useful identifier. Also what you are returning
> is per-filesystem data, not per-file. This needs to go into statfs,
> not into stat. We're about to introduce flags for statfs, so try
> to do it ontop of those.
>
> The same thing applies to the remote flag in the next patch.

Which means that you have to do two calls (xstat+statfs) to find this
information that we can return pretty much for free here, though you can cache
it based on st_dev, I suppose.

Also, not all the flags are per-filesystem. The following are:

FS_SPECIAL_FL /* Special file as found in procfs/sysfs */
FS_REMOTE_FL /* File is remote */

but the rest aren't:

FS_AUTOMOUNT_FL /* Specific automount point */
FS_AUTOMOUNT_ANY_FL /* Unspecific automount directory */
FS_ENCRYPTED_FL /* File is encrypted */
FS_HIDDEN_FL /* File is marked hidden (DOS+) */
FS_SYSTEM_FL /* File is marked system (DOS+) */
FS_ARCHIVE_FL /* File is marked archive (DOS+) */
FS_TEMPORARY_FL /* File is temporary (NTFS/CIFS) */
FS_OFFLINE_FL /* File is offline (CIFS) */
FS_REPARSE_POINT_FL /* Reparse point (NTFS/CIFS) */

David
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From: David Howells on 27 Jul 2010 09:50
David Howells <dhowells(a)redhat.com> wrote:

> Also, not all the flags are per-filesystem. The following are:
>
> FS_SPECIAL_FL /* Special file as found in procfs/sysfs */
> FS_REMOTE_FL /* File is remote */

Actually, that last is not true; FS_REMOTE_FL is per-file, not per-fs. You
can have a filesystem that has fabricated files and remote files. For
instance, with kAFS at some point you will be go into /afs, do a lookup for a
directory that doesn't exist, but whose name represents a cell+volume, the
filesystem will fabricate a local directory and then attempt to mount a remote
directory on to it.

David
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