[PATCH 3/3] Add a pair of system calls to make extended file stats available

[David Howells]

Joel Becker <Joel.Becker at oracle.com> wrote:

> 	The less variable length stuff the better, I think.  At least,
> for the stuff stat(2) already returns, you should have a fixed-size
> structure.  Even if I only pass the GIVE_ME_UIDS flag, I don't want to
> have to deal with the variable size stuff until I've actually asked for
> esoteric things.  I'll know that the non-UIDS fields are garbage by the
> fact that I didn't ask for them.

I was thinking of the fixed length xstat struct plus appendable extensions to
be defined later.

I could live with each defined extension being of a fixed length, so for
example, you set bit 20, and it adds, say, a 16-byte volume ID in the
appropriate order, padded out appropriately for the filesystem.

David