Re: [PATCH 2/3] nfsd4: fix mixed 4.0/4.1 handling, 4.1 reboot

[Benny Halevy <bhalevy@panasas.com>]

On 2010-12-07 02:09, J. Bruce Fields wrote:
> Instead of failing to find client entries which don't match the
> minorversion, we should be finding them, then either erroring out or
> expiring them as appropriate.
> 
> This also fixes a problem which would cause the 4.1 server to fail to
> recognize clients after a second reboot.
> 
> Reported-by: Casey Bodley <cbodley@citi.umich.edu>
> Signed-off-by: J. Bruce Fields <bfields@redhat.com>
> ---
>  fs/nfsd/nfs4recover.c |    1 -
>  fs/nfsd/nfs4state.c   |   37 +++++++++++++++++--------------------
>  2 files changed, 17 insertions(+), 21 deletions(-)
> 
> diff --git a/fs/nfsd/nfs4recover.c b/fs/nfsd/nfs4recover.c
> index 7e26caa..ffb59ef 100644
> --- a/fs/nfsd/nfs4recover.c
> +++ b/fs/nfsd/nfs4recover.c
> @@ -302,7 +302,6 @@ purge_old(struct dentry *parent, struct dentry *child)
>  {
>  	int status;
>  
> -	/* note: we currently use this path only for minorversion 0 */
>  	if (nfs4_has_reclaimed_state(child->d_name.name, false))
>  		return 0;
>  
> diff --git a/fs/nfsd/nfs4state.c b/fs/nfsd/nfs4state.c
> index febb283..d1e37ba 100644
> --- a/fs/nfsd/nfs4state.c
> +++ b/fs/nfsd/nfs4state.c
> @@ -1134,39 +1134,30 @@ find_unconfirmed_client(clientid_t *clid)
>  	return NULL;
>  }
>  
> -/*
> - * FIXME: we need to unify the clientid namespaces for nfsv4.x
> - * and correctly deal with client upgrade/downgrade in EXCHANGE_ID
> - * and SET_CLIENTID{,_CONFIRM}
> - */
>  static bool clp_used_exchangeid(struct nfs4_client *clp)
>  {
>  	return clp->cl_exchange_flags != 0;
> -}
> +} 

nit: looks like this line adds a trailing space character...

>  
>  static struct nfs4_client *
> -find_confirmed_client_by_str(const char *dname, unsigned int hashval,
> -			     bool use_exchange_id)
> +find_confirmed_client_by_str(const char *dname, unsigned int hashval)
>  {
>  	struct nfs4_client *clp;
>  
>  	list_for_each_entry(clp, &conf_str_hashtbl[hashval], cl_strhash) {
> -		if (same_name(clp->cl_recdir, dname) &&
> -		    clp_used_exchangeid(clp) == use_exchange_id)
> +		if (same_name(clp->cl_recdir, dname))
>  			return clp;
>  	}
>  	return NULL;
>  }
>  
>  static struct nfs4_client *
> -find_unconfirmed_client_by_str(const char *dname, unsigned int hashval,
> -			       bool use_exchange_id)
> +find_unconfirmed_client_by_str(const char *dname, unsigned int hashval)
>  {
>  	struct nfs4_client *clp;
>  
>  	list_for_each_entry(clp, &unconf_str_hashtbl[hashval], cl_strhash) {
> -		if (same_name(clp->cl_recdir, dname) &&
> -		    clp_used_exchangeid(clp) == use_exchange_id)
> +		if (same_name(clp->cl_recdir, dname))
>  			return clp;
>  	}
>  	return NULL;
> @@ -1357,8 +1348,12 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
>  	nfs4_lock_state();
>  	status = nfs_ok;
>  
> -	conf = find_confirmed_client_by_str(dname, strhashval, true);
> +	conf = find_confirmed_client_by_str(dname, strhashval);
>  	if (conf) {
> +		if (!clp_used_exchangeid(conf)) {
> +			status = nfserr_clid_inuse; /* XXX: ? */
> +			goto out;
> +		}

So if a client host wants to mount a server both over v4.0 and v4.1
it should use different client names?
Just wondering, is that required by RFC5661?

Benny

>  		if (!same_verf(&verf, &conf->cl_verifier)) {
>  			/* 18.35.4 case 8 */
>  			if (exid->flags & EXCHGID4_FLAG_UPD_CONFIRMED_REC_A) {
> @@ -1399,7 +1394,7 @@ nfsd4_exchange_id(struct svc_rqst *rqstp,
>  		goto out;
>  	}
>  
> -	unconf  = find_unconfirmed_client_by_str(dname, strhashval, true);
> +	unconf  = find_unconfirmed_client_by_str(dname, strhashval);
>  	if (unconf) {
>  		/*
>  		 * Possible retry or client restart.  Per 18.35.4 case 4,
> @@ -1799,10 +1794,12 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	strhashval = clientstr_hashval(dname);
>  
>  	nfs4_lock_state();
> -	conf = find_confirmed_client_by_str(dname, strhashval, false);
> +	conf = find_confirmed_client_by_str(dname, strhashval);
>  	if (conf) {
>  		/* RFC 3530 14.2.33 CASE 0: */
>  		status = nfserr_clid_inuse;
> +		if (clp_used_exchangeid(conf))
> +			goto out;
>  		if (!same_creds(&conf->cl_cred, &rqstp->rq_cred)) {
>  			char addr_str[INET6_ADDRSTRLEN];
>  			rpc_ntop((struct sockaddr *) &conf->cl_addr, addr_str,
> @@ -1817,7 +1814,7 @@ nfsd4_setclientid(struct svc_rqst *rqstp, struct nfsd4_compound_state *cstate,
>  	 * has a description of SETCLIENTID request processing consisting
>  	 * of 5 bullet points, labeled as CASE0 - CASE4 below.
>  	 */
> -	unconf = find_unconfirmed_client_by_str(dname, strhashval, false);
> +	unconf = find_unconfirmed_client_by_str(dname, strhashval);
>  	status = nfserr_resource;
>  	if (!conf) {
>  		/*
> @@ -1962,7 +1959,7 @@ nfsd4_setclientid_confirm(struct svc_rqst *rqstp,
>  			unsigned int hash =
>  				clientstr_hashval(unconf->cl_recdir);
>  			conf = find_confirmed_client_by_str(unconf->cl_recdir,
> -							    hash, false);
> +							    hash);
>  			if (conf) {
>  				nfsd4_remove_clid_dir(conf);
>  				expire_client(conf);
> @@ -4106,7 +4103,7 @@ nfs4_has_reclaimed_state(const char *name, bool use_exchange_id)
>  	unsigned int strhashval = clientstr_hashval(name);
>  	struct nfs4_client *clp;
>  
> -	clp = find_confirmed_client_by_str(name, strhashval, use_exchange_id);
> +	clp = find_confirmed_client_by_str(name, strhashval);
>  	return clp ? 1 : 0;
>  }
>