[PATCH] Change hash_mem to an inline function.

Implementing hash_str as hash_mem(..., strlen()) is actually quite slow,
so create a separate hash_str.

Now hash_mem has only one call site, and both are quite small, so we make them
both inline.

include/linux/sunrpc/svcauth.h

@@ -14,7 +14,7 @@
 #include <linux/string.h>
 #include <linux/sunrpc/msg_prot.h>
 #include <linux/sunrpc/cache.h>
-#include <linux/string.h>
+#include <linux/hash.h>
 
 struct svc_cred {
 	uid_t			cr_uid;
@@ -113,10 +113,41 @@ 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 hash_mem(char *buf, int len, int bits);
-static inline int hash_str(char *name, int bits)
+static inline unsigned long hash_str(char *name, int bits)
+{
+	unsigned long hash = 0;
+	unsigned long l = 0;
+	int len = 0;
+	unsigned char c;
+	do {
+		if (unlikely(!(c = *name++))) {
+			c = (char)len; len = -1;
+		}
+		l = (l << 8) | c;
+		len++;
+		if ((len & (BITS_PER_LONG/8-1))==0)
+			hash = hash_long(hash^l, BITS_PER_LONG);
+	} while (len);
+	return hash >> (BITS_PER_LONG - bits);
+}
+
+static inline unsigned long hash_mem(char *buf, int length, int bits)
 {
-	return hash_mem(name, strlen(name), bits);
+	unsigned long hash = 0;
+	unsigned long l = 0;
+	int len = 0;
+	unsigned char c;
+	do {
+		if (len == length) {
+			c = (char)len; len = -1;
+		} else
+			c = *buf++;
+		l = (l << 8) | c;
+		len++;
+		if ((len & (BITS_PER_LONG/8-1))==0)
+			hash = hash_long(hash^l, BITS_PER_LONG);
+	} while (len);
+	return hash >> (BITS_PER_LONG - bits);
 }
 
 extern struct cache_detail auth_domain_cache, ip_map_cache;

net/sunrpc/svcauth.c

@@ -97,25 +97,6 @@ svc_auth_unregister(rpc_authflavor_t flavor)
  * it will complain.
  */
 
-int hash_mem(char *buf, int len, int bits)
-{
-	int hash = 0;
-	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);
-	}
-	if (len) {
-		l=0;
-		memcpy((char*)&l, buf, len);
-		hash ^= hash_long(l, bits);
-	}
-	return hash;
-}
-
-
 /*
  * Auth auth_domain cache is somewhat different to other caches,
  * largely because the entries are possibly of different types: