Re: [RFC PATCH 4/4] Directory listing support for union mounted directories.

[Trond Myklebust <trond.myklebust@fys.uio.no>]

On Wed, 2007-06-20 at 13:09 +0100, Christoph Hellwig wrote:
> On Wed, Jun 20, 2007 at 11:24:18AM +0530, Bharata B Rao wrote:
> > From: Bharata B Rao <bharata@linux.vnet.ibm.com>
> > Subject: Directory listing support for union mounted directories.
> > 
> > Modifies readdir()/getdents() to support union mounted directories.
> > 
> > This patch adds support to readdir()/getdents() to read directory entries
> > from all the directories of the union stack, and present a merged view to
> > the userspace. This is achieved by maintaining a cache of read entries.
> > 
> > TODO: Breaks lseek on union mounted directories, Fix this.
> 
> Btw, to avoid dealing with file structs representing multiple objects
> ->readdir should be changed to an inode_operation and not take a struct
> file * but rather struct inode + loff_t *ppos.  This sounds like a nice
> preparatory patch for any kind of union mount implementation and is
> acceptable standing on it's own.

No it shouldn't. The struct file contains other stateful information
from the open() call (such as authentication info) that needs to be
passed into readdir.

Trond