Re: Urgent help needed on an NFS question, please help!!!

[Matthew Wilcox <matthew@wil.cx>]

On Thu, Aug 10, 2006 at 11:15:57AM -0400, Xin Zhao wrote:
> I am considering another possibility: suppose client C1 does lookup()
> on file X and gets a file handle, which include inode number,
> generation number and parent's inode number. Before C1 issues
> getattr(), C2 move the parent directory to a different place, which
> will not change the parent's inode number, neither the file X's inode,
> i_generation. So when C1 issues a getattr() request with this file
> handle, the server seems to have no way to detect that file X is not
> existent at the original path. Instead, the server will returns the
> moved X's attributes, which are correct, but semantically wrong. Is
> there any way that server deal with this problem?

It isn't semantically wrong.  There is no way for the application to
distinguish between the events:

open()
stat()
	mv

and

open()
	mv
stat()

As long as the results are consistent with the former case, it doesn't
matter if the latter case actually happened.