Re: Recursive directory accounting for size, ctime, etc.

From: Sage Weil
Date: Tue Jul 15 2008 - 17:18:38 EST


On Tue, 15 Jul 2008, J. Bruce Fields wrote:
> I just wonder how one would explain to users (or application writers)
> why changes to a file are reflected in the parent's rctime in one case,
> and not in another, especially if the primary link is otherwise
> indistinguishable from the others. The symptoms could be a bit
> mysterious from their point of view.

Yes. I'm not sure it can really be avoided, though. I'm trying to lift
the usual restriction of having to predefine what the
volume/subvolume/qtree boundary is and then disallowing links/renames
between then. When all of a file's links are contained within the
directory you're looking at (i.e. something that might be a subvolume
under that paradigm), things look sensible. If links span two directories
and you're looking at recursive stats for a dir containing only one of
them, then you're necessarily going to have some weirdness (you don't want
to double-count).

Making the primary/remote-ness visible to users somehow (via, say, a
virtual xattr) might help a bit. The bottom line, though, is that links
from multiple points in the namespace and a hierarchical view of file
_content_ aren't particularly compatible concepts...

sage
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