Carsten Bormann <[EMAIL PROTECTED]> wrote:
> On Dec 29 2007, at 08:33, Jonathan Loran wrote:
>
> > We snapshot the file as it exists at the time of
> > the mv in the old file system until all referring file handles are
> > closed, then destroy the single file snap. I know, not easy to
> > implement, but that is the correct behavior, I believe.
>
> Exactly.
>
> Note that apart from open descriptors, there may be other links to the
> file on the old FS; it has to be clear whether writes to the file in
> the new FS change the file in the old FS or not. I'd rather say they
> shouldn't.
> Yes, this would be different from the normal rename(2) semantics with
> respect to multiply linked files. And yes, the semantics of link(2)
> should also be consistent with this.
This in an interesting problem. Your proposal would imply that a file
may have different identities in different filesystems:
- different st_dev
- different st_ino
- different link count
This cannot be implemented with a single "inode data" anymore.
Well, it is not impossible as my WOFS (mentioned before) implements
hardlinks via "inode relative symlinks". In order to allow this. a file
would need a storage pool global serial number that allows to match different
inode sets for the file.
Jörg
--
EMail:[EMAIL PROTECTED] (home) Jörg Schilling D-13353 Berlin
[EMAIL PROTECTED] (uni)
[EMAIL PROTECTED] (work) Blog: http://schily.blogspot.com/
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