Re: topics for the file system mini-summit

[Arjan van de Ven <arjan@linux.intel.com>]

Matthew Wilcox wrote:
> On Wed, May 31, 2006 at 08:24:18PM -0700, Valerie Henson wrote:
>> Actually, the continuation inode is in B.  When we create a link in
>> directory A to file C, a continuation inode for directory A is created
>> in domain B, and a block containing the link to file C is allocated
>> inside domain B as well.  So there is no continuation inode in domain
>> A.
>>
>> That being said, this idea is at the hand-waving stage and probably
>> has many other (hopefully non-fatal) flaws.  Thanks for taking a look!
> 
> OK, so we really have two kinds of continuation inodes, and it might be
> sensible to name them differently.  We have "here's some extra data for
> that inode over there" and "here's a hardlink from another domain".  I
> dub the first one a 'continuation inode' and the second a 'shadow inode'.

nonono

the "hardlink" is in a directory inode, and that *directory* has a continuation
for the dentry that constitutes the hardlink. But that dentry is "local" to the data.
so the directory ends up being split over the domains

> Another advantage to this is that inodes never refer to blocks outside
> their zone, so we can forget about all this '64-bit block number' crap.

exactly the point!