Autofs 4 and 5 with nfs4

Autofs 4 and 5 with nfs4

[Howard Wilkinson]

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I have a site that is currently using NFS4 for most of its traffic. We 
have a mix of autofs4 and autofs5 clients. The following map is used to 
provide access to host filing system exports

Auto.master:

/hosts     auto.hosts

auto.hosts

*       -fstype=nfs4,tcp,rsize=32768,wsize=32768,hard,intr,nodev,nosuid &:/

This works fine in both autofs4 and autofs5 if the client is not the 
server (i.e. loopback ...) However with autofs5 this returns the root of 
the local file system not the exported nfs4 root.

Is there a map syntax that would work round this? Ideally I would like 
the map to be the same on all hosts, I can have different maps on the 
autofs4 and autofs5 hosts easily but would not want to have a separate 
map per host.
-- 

Howard Wilkinson

	

Phone:

	

+44(20)76907075

Coherent Technology Limited

	

Fax:

	

 

23 Northampton Square,

	

Mobile:

	

+44(7980)639379

United Kingdom, EC1V 0HL

	

Email:

	

howard@cohtech.com

 


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Re: Autofs 4 and 5 with nfs4

[Ian Kent]

On Wed, 2007-07-25 at 13:45 +0100, Howard Wilkinson wrote:
> I have a site that is currently using NFS4 for most of its traffic. We
> have a mix of autofs4 and autofs5 clients. The following map is used
> to provide access to host filing system exports
> 
> Auto.master:
> 
> /hosts     auto.hosts
> 
> auto.hosts
> 
> *
> -fstype=nfs4,tcp,rsize=32768,wsize=32768,hard,intr,nodev,nosuid &:/
> 
> This works fine in both autofs4 and autofs5 if the client is not the
> server (i.e. loopback ...) However with autofs5 this returns the root
> of the local file system not the exported nfs4 root.

Hahaha!!!

Yes, that's certainly something I didn't anticipate.

Historically, all local mounts are turned into bind mounts regardless of
the options specified. I can't think of an acceptable way to do this and
still use bind mounts so we need to consider under what conditions to
not mount local mounts as bind mounts.

I had a similar report recently and said that people expect that, if a
mount is local, it will be bind mounted for to give map independence.

So, this is a question for the list.
What do people think?


> 
> Is there a map syntax that would work round this? Ideally I would like the map to be the same on all hosts, I can have different maps on the autofs4 and autofs5 hosts easily but would not want to have a separate map per host.

No there isn't.

Ian

Re: Autofs 4 and 5 with nfs4

[Jeff Moyer]

Ian Kent <raven@themaw.net> writes:

> On Wed, 2007-07-25 at 13:45 +0100, Howard Wilkinson wrote:
>> I have a site that is currently using NFS4 for most of its traffic. We
>> have a mix of autofs4 and autofs5 clients. The following map is used
>> to provide access to host filing system exports
>> 
>> Auto.master:
>> 
>> /hosts     auto.hosts
>> 
>> auto.hosts
>> 
>> *
>> -fstype=nfs4,tcp,rsize=32768,wsize=32768,hard,intr,nodev,nosuid &:/
>> 
>> This works fine in both autofs4 and autofs5 if the client is not the
>> server (i.e. loopback ...) However with autofs5 this returns the root
>> of the local file system not the exported nfs4 root.
>
> Hahaha!!!
>
> Yes, that's certainly something I didn't anticipate.
>
> Historically, all local mounts are turned into bind mounts regardless of
> the options specified. I can't think of an acceptable way to do this and
> still use bind mounts so we need to consider under what conditions to
> not mount local mounts as bind mounts.
>
> I had a similar report recently and said that people expect that, if a
> mount is local, it will be bind mounted for to give map independence.
>
> So, this is a question for the list.
> What do people think?

Remember the nosymlink option for automount?  Well, that really meant,
"don't do special handling for local mount points."  We could
introduce a similar option, though it would be hard to do so for only
the server.

>> Is there a map syntax that would work round this? Ideally I would
>> like the map to be the same on all hosts, I can have different maps
>> on the autofs4 and autofs5 hosts easily but would not want to have
>> a separate map per host.
>
> No there isn't.

Well, autofs4 might still honor nosymlink.  I'd have to look.

-Jeff

Re: Autofs 4 and 5 with nfs4

[Ian Kent]

On Wed, 2007-08-01 at 14:50 -0400, Jeff Moyer wrote:
> Ian Kent <raven@themaw.net> writes:
> 
> > On Wed, 2007-07-25 at 13:45 +0100, Howard Wilkinson wrote:
> >> I have a site that is currently using NFS4 for most of its traffic. We
> >> have a mix of autofs4 and autofs5 clients. The following map is used
> >> to provide access to host filing system exports
> >> 
> >> Auto.master:
> >> 
> >> /hosts     auto.hosts
> >> 
> >> auto.hosts
> >> 
> >> *
> >> -fstype=nfs4,tcp,rsize=32768,wsize=32768,hard,intr,nodev,nosuid &:/
> >> 
> >> This works fine in both autofs4 and autofs5 if the client is not the
> >> server (i.e. loopback ...) However with autofs5 this returns the root
> >> of the local file system not the exported nfs4 root.
> >
> > Hahaha!!!
> >
> > Yes, that's certainly something I didn't anticipate.
> >
> > Historically, all local mounts are turned into bind mounts regardless of
> > the options specified. I can't think of an acceptable way to do this and
> > still use bind mounts so we need to consider under what conditions to
> > not mount local mounts as bind mounts.
> >
> > I had a similar report recently and said that people expect that, if a
> > mount is local, it will be bind mounted for to give map independence.
> >
> > So, this is a question for the list.
> > What do people think?
> 
> Remember the nosymlink option for automount?  Well, that really meant,
> "don't do special handling for local mount points."  We could
> introduce a similar option, though it would be hard to do so for only
> the server.
> 
> >> Is there a map syntax that would work round this? Ideally I would
> >> like the map to be the same on all hosts, I can have different maps
> >> on the autofs4 and autofs5 hosts easily but would not want to have
> >> a separate map per host.
> >
> > No there isn't.
> 
> Well, autofs4 might still honor nosymlink.  I'd have to look.

Hahahah!

Well, it's still in the code but whether it still does what's intended
is another question. And then there's the name of the option.

Ian

Re: Autofs 4 and 5 with nfs4

[Ian Kent]

On Wed, 2007-07-25 at 13:45 +0100, Howard Wilkinson wrote:
> I have a site that is currently using NFS4 for most of its traffic. We
> have a mix of autofs4 and autofs5 clients. The following map is used
> to provide access to host filing system exports
> 
> Auto.master:
> 
> /hosts     auto.hosts
> 
> auto.hosts
> 
> *
> -fstype=nfs4,tcp,rsize=32768,wsize=32768,hard,intr,nodev,nosuid &:/
> 
> This works fine in both autofs4 and autofs5 if the client is not the
> server (i.e. loopback ...) However with autofs5 this returns the root
> of the local file system not the exported nfs4 root.
> 
> Is there a map syntax that would work round this? Ideally I would like
> the map to be the same on all hosts, I can have different maps on the
> autofs4 and autofs5 hosts easily but would not want to have a separate
> map per host.

I had a look at the code which mounts these and it looks like if you
adding a port= option will force an NFS mount to be done.

Want to give it a try?

Historically the nosymlink would have had the same affect but, even
though the mount code looks for it it doesn't use it anymore. That may
not be such a bad thing given the name of the option and the fact that
it's not mentioned in the man pages. If this achieves what's needed then
I'd rather document the use of the port= option in the man pages and
keep the nosymlink a candidate for the chopping block.

Ian

Re: Autofs 4 and 5 with nfs4

[Ian Kent]

On Fri, 2007-08-03 at 12:09 +0800, Ian Kent wrote:
> > Is there a map syntax that would work round this? Ideally I would like
> > the map to be the same on all hosts, I can have different maps on the
> > autofs4 and autofs5 hosts easily but would not want to have a separate
> > map per host.
> 
> I had a look at the code which mounts these and it looks like if you
> adding a port= option will force an NFS mount to be done.
> 
> Want to give it a try?
> 
> Historically the nosymlink would have had the same affect but, even
> though the mount code looks for it it doesn't use it anymore. That may
> not be such a bad thing given the name of the option and the fact that
> it's not mentioned in the man pages. If this achieves what's needed then
> I'd rather document the use of the port= option in the man pages and
> keep the nosymlink a candidate for the chopping block.

But I just noticed you'd like the same map for v4 and v5.

Also, on second thoughts, I need to at least continue to support it for
the sake of the v4 users.

Please try this patch and let me know if it resolves the problem.

Ian

---
diff --git a/modules/mount_nfs.c b/modules/mount_nfs.c
index 25f72b9..e7a9a8a 100644
--- a/modules/mount_nfs.c
+++ b/modules/mount_nfs.c
@@ -214,7 +214,7 @@ int mount_mount(struct autofs_point *ap, const char *root, const char *name, int
 			port_opt = strstr(nfsoptions, "port=");
 
 		/* Port option specified, don't try to bind */
-		if (!port_opt && this->proximity == PROXIMITY_LOCAL) {
+		if (!nosymlink && !port_opt && this->proximity == PROXIMITY_LOCAL) {
 			/* Local host -- do a "bind" */
 			const char *bind_options = ro ? "ro" : "";