Re: Extended file stat: Splitting file- and fs-specific info?

On 05/09/2012 02:05 PM, Christoph Hellwig wrote:

On Wed, May 09, 2012 at 01:55:16PM +0200, Bernd Schubert wrote:

quoted

The basic idea of generation numbers is to check if an inode was
recycled, so only if the tuple of inode-number and generation-number
matches we still have the same file. Kernel nfs

NFS does not and should not look at the inode generation.  Except for a
bit of legacy code for the old pre-Linux 2.4 filehandles it looks at the
opaque file handle returned and only interpreted by the filesystem.  Any
userspace NFS server should do the same.

Ok, I didn't look how kernel NFS does it for quite some time already...
User space NFS only can do it beginning with 2.6.39 - given that user 
space also needs to support older kernels and other OSs, which might not 
have open_by_handle, userspace unfortunately cannot entirely rely on 
that feature.

Cheers,
Bernd