Re: [Gluster-devel] trusted.glusterfs.version xattr

[Gordan Bobic]

Martin Fick wrote:
> > --- Krishna Srinivas <address@hidden> wrote:
> >
>> >> Correct, if machines running afrs are not time sync,
>> >> it can cause problems.
>> >> We were thinking of using parent's directories
>> >> version as the file's createtime attribute. We
>> >> increment the parent dir version first then
>> >> create the file and apply parent's version as the
>> >> file's createtime.
>> >> Any thought on this?
> >
> >  /dir1/dir2/file
> >
> >   file and dir2 are deleted
> >   dir2 is re-added
> >   file is re-added and dir2 version is now the
> >        same as it was before it was deleted.
> >
> > Same problem as before but one level higher.  You
> > would need to version all the way to the root, "/",
> > for this to work, wouldn't you?

No. You just need to treat directories the same as any other file. When
a create/delete operation happens, the directory version gets bumped up.
So removing and creating a subdirectory (or a file) would result in the
created file/directory having a major version 2 versions higher than the
previous instance.

> > Directory moves could create a similar problem:
> >
> >   /dir1/dir2/file
> >   /dir1/dir3/file
> >
> >   /file and dir2 deleted.
> >   dir3 moved to dir2 and happened to match file
> >     and dir2 version #s.
> >
> > but I think that versioning to the root would again
> > solve this?

You don't need versioning up to the root, you just have to treat moves
the same way as copy+delete from the versioning point of view. This
doesn't mean you actually have to copy+delete - you just have to update
the metadata as if you did.

Gordan