[PATCH] knfsd: Use hash_long from hash.h for hashing in rpc/svc caches.

It works much better than my little toy hash functions.

fs/nfsd/export.c

@@ -24,6 +24,7 @@
 #include <linux/dcache.h>
 #include <linux/namei.h>
 #include <linux/mount.h>
+#include <linux/hash.h>
 
 #include <linux/sunrpc/svc.h>
 #include <linux/nfsd/nfsd.h>
@@ -59,12 +60,9 @@ static inline int svc_expkey_hash(struct svc_expkey *item)
 	int hash = item->ek_fsidtype;
 	char * cp = (char*)item->ek_fsid;
 	int len = (item->ek_fsidtype==0)?8:4;
-	while (len--)
-		hash += *cp++;
-	cp = (char*)&item->ek_client;
-	len = sizeof(item->ek_client);
-	while (len--)
-		hash += *cp++;
+
+	hash ^= hash_mem(cp, len, EXPKEY_HASHBITS);
+	hash ^= hash_ptr(item->ek_client, EXPKEY_HASHBITS);
 	return hash & EXPKEY_HASHMASK;
 }
 
@@ -239,17 +237,12 @@ static struct cache_head *export_table[EXPORT_HASHMAX];
 
 static inline int svc_export_hash(struct svc_export *item)
 {
-	void *k[2];
-	unsigned char *cp;
-	int rv, i;
-	k[0] = item->ex_client;
-	k[1] = item->ex_dentry;
-
-	cp = (char*)k;
-	rv = 0;
-	for (i=0; i<sizeof(k); i++)
-		rv ^= cp[i];
-	return rv & EXPORT_HASHMASK;
+	int rv;
+
+	rv = hash_ptr(item->ex_client, EXPORT_HASHBITS);
+	rv ^= hash_ptr(item->ex_dentry, EXPORT_HASHBITS);
+	rv ^= hash_ptr(item->ex_mnt, EXPORT_HASHBITS);
+	return rv;
 }
 
 void svc_export_put(struct cache_head *item, struct cache_detail *cd)

include/linux/sunrpc/svcauth.h

@@ -111,7 +111,11 @@ extern struct auth_domain *auth_unix_lookup(struct in_addr addr);
 extern int auth_unix_forget_old(struct auth_domain *dom);
 extern void svcauth_unix_purge(void);
 
-extern int name_hash(char *name, int size);
+extern int hash_mem(char *buf, int len, int bits);
+static inline int hash_str(char *name, int bits)
+{
+	return hash_mem(name, strlen(name), bits);
+}
 
 extern struct cache_detail auth_domain_cache, ip_map_cache;
 

net/sunrpc/svcauth.c

@@ -16,6 +16,7 @@
 #include <linux/sunrpc/svcsock.h>
 #include <linux/sunrpc/svcauth.h>
 #include <linux/err.h>
+#include <linux/hash.h>
 
 #define RPCDBG_FACILITY	RPCDBG_AUTH
 
@@ -111,14 +112,22 @@ svc_auth_unregister(rpc_authflavor_t flavor)
  * it will complain.
  */
 
-int name_hash(char *name, int size)
+int hash_mem(char *buf, int len, int bits)
 {
 	int hash = 0;
-	while (*name) {
-		hash += *name;
-		name++;
+	unsigned long l;
+	while (len >= BITS_PER_LONG/8) {
+		l = *(unsigned long *)buf;
+		buf += BITS_PER_LONG/8;
+		len -= BITS_PER_LONG/8;
+		hash ^= hash_long(l, bits);
 	}
-	return hash % size;
+	if (len) {
+		l=0;
+		memcpy((char*)&l, buf, len);
+		hash ^= hash_long(l, bits);
+	}
+	return hash;
 }
 
 
@@ -161,7 +170,7 @@ void auth_domain_put(struct auth_domain *dom)
 
 static inline int auth_domain_hash(struct auth_domain *item)
 {
-	return name_hash(item->name, DN_HASHMAX);
+	return hash_str(item->name, DN_HASHBITS);
 }
 static inline int auth_domain_match(struct auth_domain *tmp, struct auth_domain *item)
 {

net/sunrpc/svcauth_unix.c

@@ -6,6 +6,7 @@
 #include <linux/sunrpc/svcauth.h>
 #include <linux/err.h>
 #include <linux/seq_file.h>
+#include <linux/hash.h>
 
 #define RPCDBG_FACILITY	RPCDBG_AUTH
 
@@ -108,7 +109,8 @@ void ip_map_put(struct cache_head *item, struct cache_detail *cd)
 
 static inline int ip_map_hash(struct ip_map *item)
 {
-	return (name_hash(item->m_class, IP_HASHMAX) ^ item->m_addr.s_addr) & IP_HASHMASK;
+	return hash_str(item->m_class, IP_HASHBITS) ^ 
+		hash_long((unsigned long)item->m_addr.s_addr, IP_HASHBITS);
 }
 static inline int ip_map_match(struct ip_map *item, struct ip_map *tmp)
 {