[Linux-cachefs] Having trouble with the latest cachefiles

[David Howells]

John Groves <John at groves.net> wrote:

> Secondly, I've built the GIT kernel with your nfs+fscache-42 patches applied
> (all went in cleanly).

There's now a -43 with a bug fix in it for NFSv4 caching.

> I'm running this kernel on an otherwise clean Fedora 10 system.  fscache and
> cachefiles modules load cleanly, but I can't get cachefilesd to run.  If I
> "yum install cachefilesd", I get version 0.7-5, and it complains that
> /proc/fs/cachefiles is missing.

You need to use cachefilesd-0.9.  The way I had cachefilesd talking to the
kernel in the earlier versions was rejected by the upstream people.

> If I build cachefilesd-0.9, I a kernel BUG.  The relevant lines from
> /var/log/messages are attached.

I submitted a patch for this and Linus has applied it to the upstream tree:

    commit 43529c97122f2c851126447963eedcb8cba74fbe
    Author: David Howells <dhowells at redhat.com>
    Date:   Fri Jan 9 16:13:46 2009 +0000

	CRED: Must initialise the new creds in prepare_kernel_cred()

	The newly allocated creds in prepare_kernel_cred() must be initialised
	before get_uid() and get_group_info() can access them.  They should be
	copied from the old credentials.

	Reported-by: Steve Dickson <steved at redhat.com>
	Signed-off-by: David Howells <dhowells at redhat.com>
	Acked-by: Steve Dickson <steved at redhat.com>
	Signed-off-by: Linus Torvalds <torvalds at linux-foundation.org>

David