[PATCH] NFS: Make NFS root work again

[PATCH] NFS: Make NFS root work again

[David Howells]

Make NFS root work by creating a "/root" directory to satisfy the mount,
otherwise the path lookup for the mount fails with ENOENT.

Signed-off-by: David Howells <dhowells@redhat.com>
---

 init/do_mounts.c |    5 ++++-
 1 files changed, 4 insertions(+), 1 deletions(-)

diff --git a/init/do_mounts.c b/init/do_mounts.c
index 46fe407..967b852 100644
--- a/init/do_mounts.c
+++ b/init/do_mounts.c
@@ -270,7 +270,10 @@ static void __init get_fs_names(char *page)
 
 static int __init do_mount_root(char *name, char *fs, int flags, void *data)
 {
-	int err = sys_mount(name, "/root", fs, flags, data);
+	int err;
+
+	sys_mkdir("/root", 0755);
+	err = sys_mount(name, "/root", fs, flags, data);
 	if (err)
 		return err;
 

Re: [PATCH] NFS: Make NFS root work again

[Peter Staubach]

David Howells wrote:
> Make NFS root work by creating a "/root" directory to satisfy the mount,
> otherwise the path lookup for the mount fails with ENOENT.
>
> Signed-off-by: David Howells <dhowells@redhat.com>
> ---
>
>  init/do_mounts.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
>
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 46fe407..967b852 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -270,7 +270,10 @@ static void __init get_fs_names(char *page)
>  
>  static int __init do_mount_root(char *name, char *fs, int flags, void *data)
>  {
> -	int err = sys_mount(name, "/root", fs, flags, data);
> +	int err;
> +
> +	sys_mkdir("/root", 0755);
> +	err = sys_mount(name, "/root", fs, flags, data);
>  	if (err)
>  		return err;

It seems to me that if sys_mkdir() fails with anything other other
than EEXISTS, then sys_mount() will continue to fail.  Is this
something that we care about?

       ps

Re: [PATCH] NFS: Make NFS root work again

[Andrew Morton]

On Thu, 07 Jun 2007 17:40:03 +0100
David Howells <dhowells@redhat.com> wrote:

> Make NFS root work by creating a "/root" directory to satisfy the mount,
> otherwise the path lookup for the mount fails with ENOENT.
> 

What did we do to make it stop working, and when did we do it??

> 
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 46fe407..967b852 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -270,7 +270,10 @@ static void __init get_fs_names(char *page)
>  
>  static int __init do_mount_root(char *name, char *fs, int flags, void *data)
>  {
> -	int err = sys_mount(name, "/root", fs, flags, data);
> +	int err;
> +
> +	sys_mkdir("/root", 0755);
> +	err = sys_mount(name, "/root", fs, flags, data);
>  	if (err)
>  		return err;
>  

Re: [PATCH] NFS: Make NFS root work again

[Andrew Morton]

On Thu, 07 Jun 2007 17:40:03 +0100 David Howells <dhowells@redhat.com> wrote:

> Make NFS root work by creating a "/root" directory to satisfy the mount,
> otherwise the path lookup for the mount fails with ENOENT.
> 
> Signed-off-by: David Howells <dhowells@redhat.com>
> ---
> 
>  init/do_mounts.c |    5 ++++-
>  1 files changed, 4 insertions(+), 1 deletions(-)
> 
> diff --git a/init/do_mounts.c b/init/do_mounts.c
> index 46fe407..967b852 100644
> --- a/init/do_mounts.c
> +++ b/init/do_mounts.c
> @@ -270,7 +270,10 @@ static void __init get_fs_names(char *page)
>  
>  static int __init do_mount_root(char *name, char *fs, int flags, void *data)
>  {
> -	int err = sys_mount(name, "/root", fs, flags, data);
> +	int err;
> +
> +	sys_mkdir("/root", 0755);
> +	err = sys_mount(name, "/root", fs, flags, data);
>  	if (err)
>  		return err;

Am still awaiting a proper description of this patch, please.

What is not working, and how does this patch fix it?

I am unaware of any open bug reports against NFS root.

Re: [PATCH] NFS: Make NFS root work again

[Trond Myklebust]

On Sat, 2007-06-16 at 09:15 -0700, Andrew Morton wrote:
> On Thu, 07 Jun 2007 17:40:03 +0100 David Howells <dhowells@redhat.com> wrote:
> 
> > Make NFS root work by creating a "/root" directory to satisfy the mount,
> > otherwise the path lookup for the mount fails with ENOENT.
> > 
> > Signed-off-by: David Howells <dhowells@redhat.com>
> > ---
> > 
> >  init/do_mounts.c |    5 ++++-
> >  1 files changed, 4 insertions(+), 1 deletions(-)
> > 
> > diff --git a/init/do_mounts.c b/init/do_mounts.c
> > index 46fe407..967b852 100644
> > --- a/init/do_mounts.c
> > +++ b/init/do_mounts.c
> > @@ -270,7 +270,10 @@ static void __init get_fs_names(char *page)
> >  
> >  static int __init do_mount_root(char *name, char *fs, int flags, void *data)
> >  {
> > -	int err = sys_mount(name, "/root", fs, flags, data);
> > +	int err;
> > +
> > +	sys_mkdir("/root", 0755);
> > +	err = sys_mount(name, "/root", fs, flags, data);
> >  	if (err)
> >  		return err;
> 
> Am still awaiting a proper description of this patch, please.
> 
> What is not working, and how does this patch fix it?
> 
> I am unaware of any open bug reports against NFS root.

I'm confused too. We never used to require that the kernel create a
special /root directory. What changed, and when?

Trond

Re: [PATCH] NFS: Make NFS root work again

[Paul Mundt]

On Sat, Jun 16, 2007 at 09:15:14AM -0700, Andrew Morton wrote:
> On Thu, 07 Jun 2007 17:40:03 +0100 David Howells <dhowells@redhat.com> wrote:
> > Make NFS root work by creating a "/root" directory to satisfy the mount,
> > otherwise the path lookup for the mount fails with ENOENT.
> > 
> 
> Am still awaiting a proper description of this patch, please.
> 
> What is not working, and how does this patch fix it?
> 
> I am unaware of any open bug reports against NFS root.

I've not had any problems with it during any of the -rc periods, for what
it's worth.

Re: [PATCH] NFS: Make NFS root work again

[Andi Kleen]

Andrew Morton <akpm@linux-foundation.org> writes:
> 
> What is not working, and how does this patch fix it?

FWIW i use nfs root regularly for testing kernels and it works
for me.

-Andi

Re: [PATCH] NFS: Make NFS root work again

[David Howells]

Andrew Morton <akpm@linux-foundation.org> wrote:

> What is not working, and how does this patch fix it?

It turns out that this patch is unnecessary.  The problem had to do with the
initcalling of default_rootfs() (or lack of initcalling in this case).  I
fixed vmlinux.lds.S and it works now.

David