Re: [PATCH 2/2] NFSv4: Use the net namespace uniquifier if it is set

[Trond Myklebust <trondmy@hammerspace.com>]

On Wed, 2020-10-07 at 15:02 -0700, Dai Ngo wrote:
> On 10/7/20 2:07 PM, trondmy@kernel.org wrote:
> > From: Trond Myklebust <trond.myklebust@hammerspace.com>
> > 
> > If a container sets a net namespace specific uniquifier, then use
> > that
> > in the setclientid/exchangeid process.
> > 
> > Signed-off-by: Trond Myklebust <trond.myklebust@hammerspace.com>
> > ---
> >   fs/nfs/nfs4proc.c | 23 ++++++++++++++++++++---
> >   1 file changed, 20 insertions(+), 3 deletions(-)
> > 
> > diff --git a/fs/nfs/nfs4proc.c b/fs/nfs/nfs4proc.c
> > index 3a39887e0e6e..a1dd46e7440b 100644
> > --- a/fs/nfs/nfs4proc.c
> > +++ b/fs/nfs/nfs4proc.c
> > @@ -63,6 +63,7 @@
> >   #include "callback.h"
> >   #include "pnfs.h"
> >   #include "netns.h"
> > +#include "sysfs.h"
> >   #include "nfs4idmap.h"
> >   #include "nfs4session.h"
> >   #include "fscache.h"
> > @@ -6007,9 +6008,25 @@ static void nfs4_init_boot_verifier(const
> > struct nfs_client *clp,
> >   }
> >   
> >   static size_t
> > -nfs4_get_uniquifier(char *buf, size_t buflen)
> > +nfs4_get_uniquifier(struct nfs_client *clp, char *buf, size_t
> > buflen)
> >   {
> > +	struct nfs_net *nn = net_generic(clp->cl_net, nfs_net_id);
> > +	struct nfs_netns_client *nn_clp = nn->nfs_client;
> > +	const char *id;
> > +	size_t len;
> > +
> >   	buf[0] = '\0';
> > +
> > +	if (nn_clp) {
> > +		rcu_read_lock();
> > +		id = rcu_dereference(nn_clp->identifier);
> > +		if (id && *id != '\0')
> > +			len = strlcpy(buf, id, buflen);
> > +		rcu_read_unlock();
> > +		if (len)
> 
> I think 'len' can be uninitialized here.

Thanks. Yes, already noted and fixed in v2.

> 
> -Dai
> 
> > +			return len;
> > +	}
> > +
> >   	if (nfs4_client_id_uniquifier[0] != '\0')
> >   		return strlcpy(buf, nfs4_client_id_uniquifier, buflen);
> >   	return 0;
> > @@ -6034,7 +6051,7 @@ nfs4_init_nonuniform_client_string(struct
> > nfs_client *clp)
> >   		1;
> >   	rcu_read_unlock();
> >   
> > -	buflen = nfs4_get_uniquifier(buf, sizeof(buf));
> > +	buflen = nfs4_get_uniquifier(clp, buf, sizeof(buf));
> >   	if (buflen)
> >   		len += buflen + 1;
> >   
> > @@ -6081,7 +6098,7 @@ nfs4_init_uniform_client_string(struct
> > nfs_client *clp)
> >   	len = 10 + 10 + 1 + 10 + 1 +
> >   		strlen(clp->cl_rpcclient->cl_nodename) + 1;
> >   
> > -	buflen = nfs4_get_uniquifier(buf, sizeof(buf));
> > +	buflen = nfs4_get_uniquifier(clp, buf, sizeof(buf));
> >   	if (buflen)
> >   		len += buflen + 1;
> >   
-- 
Trond Myklebust
Linux NFS client maintainer, Hammerspace
trond.myklebust@hammerspace.com