[PATCH] Use fixed size buffer instead of kmalloc for m_class in ip_map

This avoids lots of bothersome memory management and is generally
cleaner. 
Signed-off-by: Neil Brown <neilb@cse.unsw.edu.au>
Signed-off-by: J. Bruce Fields <bfields@citi.umich.edu>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

net/sunrpc/svcauth_unix.c

@@ -90,7 +90,7 @@ static void svcauth_unix_domain_release(struct auth_domain *dom)
 
 struct ip_map {
 	struct cache_head	h;
-	char			*m_class; /* e.g. "nfsd" */
+	char			m_class[8]; /* e.g. "nfsd" */
 	struct in_addr		m_addr;
 	struct unix_domain	*m_client;
 	int			m_add_change;
@@ -104,7 +104,6 @@ void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 		if (test_bit(CACHE_VALID, &item->flags) &&
 		    !test_bit(CACHE_NEGATIVE, &item->flags))
 			auth_domain_put(&im->m_client->h);
-		kfree(im->m_class);
 		kfree(im);
 	}
 }
@@ -121,8 +120,7 @@ static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 }
 static inline void ip_map_init(struct ip_map *new, struct ip_map *item)
 {
-	new->m_class = item->m_class;
-	item->m_class = NULL;
+	strcpy(new->m_class, item->m_class);
 	new->m_addr.s_addr = item->m_addr.s_addr;
 }
 static inline void ip_map_update(struct ip_map *new, struct ip_map *item)
@@ -171,6 +169,8 @@ static int ip_map_parse(struct cache_detail *cd,
 	/* class */
 	len = qword_get(&mesg, class, 50);
 	if (len <= 0) return -EINVAL;
+	if (len >= sizeof(ipm.m_class))
+		return -EINVAL;
 
 	/* ip address */
 	len = qword_get(&mesg, buf, 50);
@@ -194,9 +194,7 @@ static int ip_map_parse(struct cache_detail *cd,
 	} else
 		dom = NULL;
 
-	ipm.m_class = strdup(class);
-	if (ipm.m_class == NULL)
-		return -ENOMEM;
+	strcpy(ipm.m_class, class);
 	ipm.m_addr.s_addr =
 		htonl((((((b1<<8)|b2)<<8)|b3)<<8)|b4);
 	ipm.h.flags = 0;
@@ -212,7 +210,6 @@ static int ip_map_parse(struct cache_detail *cd,
 		ip_map_put(&ipmp->h, &ip_map_cache);
 	if (dom)
 		auth_domain_put(dom);
-	if (ipm.m_class) kfree(ipm.m_class);
 	if (!ipmp)
 		return -ENOMEM;
 	cache_flush();
@@ -272,9 +269,7 @@ int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 	if (dom->flavour != RPC_AUTH_UNIX)
 		return -EINVAL;
 	udom = container_of(dom, struct unix_domain, h);
-	ip.m_class = strdup("nfsd");
-	if (!ip.m_class)
-		return -ENOMEM;
+	strcpy(ip.m_class, "nfsd");
 	ip.m_addr = addr;
 	ip.m_client = udom;
 	ip.m_add_change = udom->addr_changes+1;
@@ -282,7 +277,7 @@ int auth_unix_add_addr(struct in_addr addr, struct auth_domain *dom)
 	ip.h.expiry_time = NEVER;
 	
 	ipmp = ip_map_lookup(&ip, 1);
-	if (ip.m_class) kfree(ip.m_class);
+
 	if (ipmp) {
 		ip_map_put(&ipmp->h, &ip_map_cache);
 		return 0;
@@ -306,7 +301,7 @@ struct auth_domain *auth_unix_lookup(struct in_addr addr)
 	struct ip_map key, *ipm;
 	struct auth_domain *rv;
 
-	key.m_class = "nfsd";
+	strcpy(key.m_class, "nfsd");
 	key.m_addr = addr;
 
 	ipm = ip_map_lookup(&key, 0);
@@ -368,7 +363,7 @@ svcauth_null_accept(struct svc_rqst *rqstp, u32 *authp)
 	svc_putu32(resv, RPC_AUTH_NULL);
 	svc_putu32(resv, 0);
 
-	key.m_class = rqstp->rq_server->sv_program->pg_class;
+	strcpy(key.m_class, rqstp->rq_server->sv_program->pg_class);
 	key.m_addr = rqstp->rq_addr.sin_addr;
 
 	ipm = ip_map_lookup(&key, 0);
@@ -464,7 +459,7 @@ svcauth_unix_accept(struct svc_rqst *rqstp, u32 *authp)
 	}
 
 
-	key.m_class = rqstp->rq_server->sv_program->pg_class;
+	strcpy(key.m_class, rqstp->rq_server->sv_program->pg_class);
 	key.m_addr = rqstp->rq_addr.sin_addr;