[RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[Cong Wang]

Signed-off-by: Cong Wang <amwang@redhat.com>
---
 include/linux/sunrpc/addr.h |  119 +++----------------------------------------
 include/net/inet_addr.h     |   56 ++++++++++++++++++++
 2 files changed, 64 insertions(+), 111 deletions(-)

diff --git a/include/linux/sunrpc/addr.h b/include/linux/sunrpc/addr.h
index 07d8e53..4c3602e 100644
--- a/include/linux/sunrpc/addr.h
+++ b/include/linux/sunrpc/addr.h
@@ -11,6 +11,7 @@
 #include <linux/in.h>
 #include <linux/in6.h>
 #include <net/ipv6.h>
+#include <net/inet_addr.h>
 
 size_t		rpc_ntop(const struct sockaddr *, char *, const size_t);
 size_t		rpc_pton(struct net *, const char *, const size_t,
@@ -21,137 +22,33 @@ size_t		rpc_uaddr2sockaddr(struct net *, const char *, const size_t,
 
 static inline unsigned short rpc_get_port(const struct sockaddr *sap)
 {
-	switch (sap->sa_family) {
-	case AF_INET:
-		return ntohs(((struct sockaddr_in *)sap)->sin_port);
-	case AF_INET6:
-		return ntohs(((struct sockaddr_in6 *)sap)->sin6_port);
-	}
-	return 0;
+	return inet_addr_get_port((const union inet_addr *)sap);
 }
 
 static inline void rpc_set_port(struct sockaddr *sap,
 				const unsigned short port)
 {
-	switch (sap->sa_family) {
-	case AF_INET:
-		((struct sockaddr_in *)sap)->sin_port = htons(port);
-		break;
-	case AF_INET6:
-		((struct sockaddr_in6 *)sap)->sin6_port = htons(port);
-		break;
-	}
+	inet_addr_set_port((union inet_addr *)sap, port);
 }
 
 #define IPV6_SCOPE_DELIMITER		'%'
 #define IPV6_SCOPE_ID_LEN		sizeof("%nnnnnnnnnn")
 
-static inline bool __rpc_cmp_addr4(const struct sockaddr *sap1,
-				   const struct sockaddr *sap2)
-{
-	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sap1;
-	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sap2;
-
-	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
-}
-
-static inline bool __rpc_copy_addr4(struct sockaddr *dst,
-				    const struct sockaddr *src)
-{
-	const struct sockaddr_in *ssin = (struct sockaddr_in *) src;
-	struct sockaddr_in *dsin = (struct sockaddr_in *) dst;
-
-	dsin->sin_family = ssin->sin_family;
-	dsin->sin_addr.s_addr = ssin->sin_addr.s_addr;
-	return true;
-}
-
-#if IS_ENABLED(CONFIG_IPV6)
-static inline bool __rpc_cmp_addr6(const struct sockaddr *sap1,
-				   const struct sockaddr *sap2)
-{
-	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sap1;
-	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sap2;
-
-	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
-		return false;
-	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
-		return sin1->sin6_scope_id == sin2->sin6_scope_id;
-
-	return true;
-}
-
-static inline bool __rpc_copy_addr6(struct sockaddr *dst,
-				    const struct sockaddr *src)
-{
-	const struct sockaddr_in6 *ssin6 = (const struct sockaddr_in6 *) src;
-	struct sockaddr_in6 *dsin6 = (struct sockaddr_in6 *) dst;
-
-	dsin6->sin6_family = ssin6->sin6_family;
-	dsin6->sin6_addr = ssin6->sin6_addr;
-	dsin6->sin6_scope_id = ssin6->sin6_scope_id;
-	return true;
-}
-#else	/* !(IS_ENABLED(CONFIG_IPV6) */
-static inline bool __rpc_cmp_addr6(const struct sockaddr *sap1,
-				   const struct sockaddr *sap2)
-{
-	return false;
-}
-
-static inline bool __rpc_copy_addr6(struct sockaddr *dst,
-				    const struct sockaddr *src)
-{
-	return false;
-}
-#endif	/* !(IS_ENABLED(CONFIG_IPV6) */
-
-/**
- * rpc_cmp_addr - compare the address portion of two sockaddrs.
- * @sap1: first sockaddr
- * @sap2: second sockaddr
- *
- * Just compares the family and address portion. Ignores port, but
- * compares the scope if it's a link-local address.
- *
- * Returns true if the addrs are equal, false if they aren't.
- */
 static inline bool rpc_cmp_addr(const struct sockaddr *sap1,
 				const struct sockaddr *sap2)
 {
-	if (sap1->sa_family == sap2->sa_family) {
-		switch (sap1->sa_family) {
-		case AF_INET:
-			return __rpc_cmp_addr4(sap1, sap2);
-		case AF_INET6:
-			return __rpc_cmp_addr6(sap1, sap2);
-		}
-	}
-	return false;
+	return inet_addr_equal((const union inet_addr *)sap1,
+			       (const union inet_addr *)sap2);
 }
 
-/**
- * rpc_copy_addr - copy the address portion of one sockaddr to another
- * @dst: destination sockaddr
- * @src: source sockaddr
- *
- * Just copies the address portion and family. Ignores port, scope, etc.
- * Caller is responsible for making certain that dst is large enough to hold
- * the address in src. Returns true if address family is supported. Returns
- * false otherwise.
- */
 static inline bool rpc_copy_addr(struct sockaddr *dst,
 				 const struct sockaddr *src)
 {
-	switch (src->sa_family) {
-	case AF_INET:
-		return __rpc_copy_addr4(dst, src);
-	case AF_INET6:
-		return __rpc_copy_addr6(dst, src);
-	}
-	return false;
+	return inet_addr_copy((union inet_addr *)dst,
+			      (const union inet_addr *)src);
 }
 
+
 /**
  * rpc_get_scope_id - return scopeid for a given sockaddr
  * @sa: sockaddr to get scopeid from
diff --git a/include/net/inet_addr.h b/include/net/inet_addr.h
index 1379287..683e904 100644
--- a/include/net/inet_addr.h
+++ b/include/net/inet_addr.h
@@ -60,6 +60,62 @@ static inline bool inet_addr_multicast(const union inet_addr *ipa)
 }
 #endif
 
+/**
+ * inet_addr_copy - copy the address portion of one sockaddr to another
+ * @dst: destination sockaddr
+ * @src: source sockaddr
+ *
+ * Just copies the address portion and family. Ignores port, scope, etc.
+ * Caller is responsible for making certain that dst is large enough to hold
+ * the address in src. Returns true if address family is supported. Returns
+ * false otherwise.
+ */
+static inline bool inet_addr_copy(union inet_addr *dst,
+				  const union inet_addr *src)
+{
+	dst->sa.sa_family = src->sa.sa_family;
+
+	switch (src->sa.sa_family) {
+	case AF_INET:
+		dst->sin.sin_addr.s_addr = src->sin.sin_addr.s_addr;
+		return true;
+#if IS_ENABLED(CONFIG_IPV6)
+	case AF_INET6:
+		dst->sin6.sin6_addr = src->sin6.sin6_addr;
+		dst->sin6.sin6_scope_id = src->sin6.sin6_scope_id;
+		return true;
+#endif
+	}
+
+	return false;
+}
+
+static inline
+unsigned short inet_addr_get_port(const union inet_addr *sap)
+{
+	switch (sap->sa.sa_family) {
+	case AF_INET:
+		return ntohs(sap->sin.sin_port);
+	case AF_INET6:
+		return ntohs(sap->sin6.sin6_port);
+	}
+	return 0;
+}
+
+static inline
+void inet_addr_set_port(union inet_addr *sap,
+			const unsigned short port)
+{
+	switch (sap->sa.sa_family) {
+	case AF_INET:
+		sap->sin.sin_port = htons(port);
+		break;
+	case AF_INET6:
+		sap->sin6.sin6_port = htons(port);
+		break;
+	}
+}
+
 static inline int inet_pton(const char *str, union inet_addr *addr)
 {
 	const char *end;
-- 
1.7.7.6

Re: [RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[Ben Hutchings]

On Thu, 2013-06-27 at 14:43 +0800, Cong Wang wrote:
[...]
> -/**
> - * rpc_cmp_addr - compare the address portion of two sockaddrs.
> - * @sap1: first sockaddr
> - * @sap2: second sockaddr
> - *
> - * Just compares the family and address portion. Ignores port, but
> - * compares the scope if it's a link-local address.

You're removing the scope comparison.

Ben.

> - * Returns true if the addrs are equal, false if they aren't.
> - */
>  static inline bool rpc_cmp_addr(const struct sockaddr *sap1,
>  				const struct sockaddr *sap2)
>  {
> -	if (sap1->sa_family == sap2->sa_family) {
> -		switch (sap1->sa_family) {
> -		case AF_INET:
> -			return __rpc_cmp_addr4(sap1, sap2);
> -		case AF_INET6:
> -			return __rpc_cmp_addr6(sap1, sap2);
> -		}
> -	}
> -	return false;
> +	return inet_addr_equal((const union inet_addr *)sap1,
> +			       (const union inet_addr *)sap2);
>  }
[...]

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[Cong Wang]

On Thu, 2013-06-27 at 16:36 +0100, Ben Hutchings wrote:
> On Thu, 2013-06-27 at 14:43 +0800, Cong Wang wrote:
> [...]
> > -/**
> > - * rpc_cmp_addr - compare the address portion of two sockaddrs.
> > - * @sap1: first sockaddr
> > - * @sap2: second sockaddr
> > - *
> > - * Just compares the family and address portion. Ignores port, but
> > - * compares the scope if it's a link-local address.
> 
> You're removing the scope comparison.

Actually I added the following code in patch 5/5:

+               if (!ipv6_addr_equal(&a->sin6.sin6_addr,
&b->sin6.sin6_addr))
+                       return false;
+               else if
(__ipv6_addr_needs_scope_id(__ipv6_addr_type(&a->sin6.sin6_addr)))
+                       return a->sin6.sin6_scope_id ==
b->sin6.sin6_scope_id;


but I should move it to this patch, otherwise it is hard for review.

Thanks!

Re: [RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[Ben Hutchings]

On Thu, 2013-06-27 at 14:43 +0800, Cong Wang wrote:
[...]
> --- a/include/net/inet_addr.h
> +++ b/include/net/inet_addr.h
> @@ -60,6 +60,62 @@ static inline bool inet_addr_multicast(const union inet_addr *ipa)
>  }
>  #endif
>  
> +/**
> + * inet_addr_copy - copy the address portion of one sockaddr to another
> + * @dst: destination sockaddr
> + * @src: source sockaddr
> + *
> + * Just copies the address portion and family. Ignores port, scope, etc.
> + * Caller is responsible for making certain that dst is large enough to hold
> + * the address in src. Returns true if address family is supported. Returns
> + * false otherwise.
> + */
> +static inline bool inet_addr_copy(union inet_addr *dst,
> +				  const union inet_addr *src)
> +{
> +	dst->sa.sa_family = src->sa.sa_family;
> +
> +	switch (src->sa.sa_family) {
> +	case AF_INET:
> +		dst->sin.sin_addr.s_addr = src->sin.sin_addr.s_addr;
> +		return true;
> +#if IS_ENABLED(CONFIG_IPV6)
> +	case AF_INET6:
> +		dst->sin6.sin6_addr = src->sin6.sin6_addr;
> +		dst->sin6.sin6_scope_id = src->sin6.sin6_scope_id;
> +		return true;
> +#endif

Most of the other functions work on IPv6 addresses without CONFIG_IPV6;
why should this be different?

Ben.

> +	}
> +
> +	return false;
> +}
[...]

-- 
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.

Re: [RFC Patch net-next 4/5] sunrpc: use generic union inet_addr

[Cong Wang]

On Thu, 2013-06-27 at 16:37 +0100, Ben Hutchings wrote:
> Most of the other functions work on IPv6 addresses without
> CONFIG_IPV6;
> why should this be different? 

Save few cycles for !CONFIG_IPV6? :-/

[RFC Patch net-next 5/5] nfs,cifs: abstract generic inet_addr_equal_strict()

[Cong Wang]

Signed-off-by: Cong Wang <amwang@redhat.com>
---
 fs/cifs/connect.c          |   38 ++++-------------
 fs/dlm/lowcomms.c          |   24 ++---------
 fs/nfs/client.c            |   94 ++-----------------------------------------
 fs/nfs/nfs4filelayoutdev.c |   37 ++---------------
 fs/nfs/super.c             |   31 +-------------
 include/net/inet_addr.h    |   32 +++++++++++++-
 6 files changed, 55 insertions(+), 201 deletions(-)

diff --git a/fs/cifs/connect.c b/fs/cifs/connect.c
index e3bc39b..ca6bcf82 100644
--- a/fs/cifs/connect.c
+++ b/fs/cifs/connect.c
@@ -40,6 +40,7 @@
 #include <linux/module.h>
 #include <keys/user-type.h>
 #include <net/ipv6.h>
+#include <net/inet_addr.h>
 #include <linux/parser.h>
 
 #include "cifspdu.h"
@@ -1886,17 +1887,10 @@ srcip_matches(struct sockaddr *srcaddr, struct sockaddr *rhs)
 {
 	switch (srcaddr->sa_family) {
 	case AF_UNSPEC:
-		return (rhs->sa_family == AF_UNSPEC);
-	case AF_INET: {
-		struct sockaddr_in *saddr4 = (struct sockaddr_in *)srcaddr;
-		struct sockaddr_in *vaddr4 = (struct sockaddr_in *)rhs;
-		return (saddr4->sin_addr.s_addr == vaddr4->sin_addr.s_addr);
-	}
-	case AF_INET6: {
-		struct sockaddr_in6 *saddr6 = (struct sockaddr_in6 *)srcaddr;
-		struct sockaddr_in6 *vaddr6 = (struct sockaddr_in6 *)rhs;
-		return ipv6_addr_equal(&saddr6->sin6_addr, &vaddr6->sin6_addr);
-	}
+	case AF_INET:
+	case AF_INET6:
+		return inet_addr_equal((union inet_addr *)srcaddr,
+				       (union inet_addr *)rhs);
 	default:
 		WARN_ON(1);
 		return false; /* don't expect to be here */
@@ -1943,24 +1937,10 @@ match_address(struct TCP_Server_Info *server, struct sockaddr *addr,
 	      struct sockaddr *srcaddr)
 {
 	switch (addr->sa_family) {
-	case AF_INET: {
-		struct sockaddr_in *addr4 = (struct sockaddr_in *)addr;
-		struct sockaddr_in *srv_addr4 =
-					(struct sockaddr_in *)&server->dstaddr;
-
-		if (addr4->sin_addr.s_addr != srv_addr4->sin_addr.s_addr)
-			return false;
-		break;
-	}
-	case AF_INET6: {
-		struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *)addr;
-		struct sockaddr_in6 *srv_addr6 =
-					(struct sockaddr_in6 *)&server->dstaddr;
-
-		if (!ipv6_addr_equal(&addr6->sin6_addr,
-				     &srv_addr6->sin6_addr))
-			return false;
-		if (addr6->sin6_scope_id != srv_addr6->sin6_scope_id)
+	case AF_INET:
+	case AF_INET6:
+		if (!inet_addr_equal((union inet_addr *)addr,
+				     (union inet_addr *)&server->dstaddr))
 			return false;
 		break;
 	}
diff --git a/fs/dlm/lowcomms.c b/fs/dlm/lowcomms.c
index d0ccd2f..c27e36e 100644
--- a/fs/dlm/lowcomms.c
+++ b/fs/dlm/lowcomms.c
@@ -55,6 +55,7 @@
 #include <linux/sctp.h>
 #include <net/sctp/sctp.h>
 #include <net/ipv6.h>
+#include <net/inet_addr.h>
 
 #include "dlm_internal.h"
 #include "lowcomms.h"
@@ -285,28 +286,13 @@ static struct dlm_node_addr *find_node_addr(int nodeid)
 static int addr_compare(struct sockaddr_storage *x, struct sockaddr_storage *y)
 {
 	switch (x->ss_family) {
-	case AF_INET: {
-		struct sockaddr_in *sinx = (struct sockaddr_in *)x;
-		struct sockaddr_in *siny = (struct sockaddr_in *)y;
-		if (sinx->sin_addr.s_addr != siny->sin_addr.s_addr)
-			return 0;
-		if (sinx->sin_port != siny->sin_port)
-			return 0;
-		break;
-	}
-	case AF_INET6: {
-		struct sockaddr_in6 *sinx = (struct sockaddr_in6 *)x;
-		struct sockaddr_in6 *siny = (struct sockaddr_in6 *)y;
-		if (!ipv6_addr_equal(&sinx->sin6_addr, &siny->sin6_addr))
-			return 0;
-		if (sinx->sin6_port != siny->sin6_port)
-			return 0;
-		break;
-	}
+	case AF_INET:
+	case AF_INET6:
+		return inet_addr_equal_strict((union inet_addr *)x,
+					      (union inet_addr *)y);
 	default:
 		return 0;
 	}
-	return 1;
 }
 
 static int nodeid_to_addr(int nodeid, struct sockaddr_storage *sas_out,
diff --git a/fs/nfs/client.c b/fs/nfs/client.c
index c513b0c..69a7561 100644
--- a/fs/nfs/client.c
+++ b/fs/nfs/client.c
@@ -38,6 +38,7 @@
 #include <linux/slab.h>
 #include <linux/idr.h>
 #include <net/ipv6.h>
+#include <net/inet_addr.h>
 #include <linux/nfs_xdr.h>
 #include <linux/sunrpc/bc_xprt.h>
 #include <linux/nsproxy.h>
@@ -283,75 +284,6 @@ void nfs_put_client(struct nfs_client *clp)
 }
 EXPORT_SYMBOL_GPL(nfs_put_client);
 
-#if defined(CONFIG_IPV6) || defined(CONFIG_IPV6_MODULE)
-/*
- * Test if two ip6 socket addresses refer to the same socket by
- * comparing relevant fields. The padding bytes specifically, are not
- * compared. sin6_flowinfo is not compared because it only affects QoS
- * and sin6_scope_id is only compared if the address is "link local"
- * because "link local" addresses need only be unique to a specific
- * link. Conversely, ordinary unicast addresses might have different
- * sin6_scope_id.
- *
- * The caller should ensure both socket addresses are AF_INET6.
- */
-static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
-	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
-
-	if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
-		return 0;
-	else if (ipv6_addr_type(&sin1->sin6_addr) & IPV6_ADDR_LINKLOCAL)
-		return sin1->sin6_scope_id == sin2->sin6_scope_id;
-
-	return 1;
-}
-#else	/* !defined(CONFIG_IPV6) && !defined(CONFIG_IPV6_MODULE) */
-static int nfs_sockaddr_match_ipaddr6(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	return 0;
-}
-#endif
-
-/*
- * Test if two ip4 socket addresses refer to the same socket, by
- * comparing relevant fields. The padding bytes specifically, are
- * not compared.
- *
- * The caller should ensure both socket addresses are AF_INET.
- */
-static int nfs_sockaddr_match_ipaddr4(const struct sockaddr *sa1,
-				      const struct sockaddr *sa2)
-{
-	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
-	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
-
-	return sin1->sin_addr.s_addr == sin2->sin_addr.s_addr;
-}
-
-static int nfs_sockaddr_cmp_ip6(const struct sockaddr *sa1,
-				const struct sockaddr *sa2)
-{
-	const struct sockaddr_in6 *sin1 = (const struct sockaddr_in6 *)sa1;
-	const struct sockaddr_in6 *sin2 = (const struct sockaddr_in6 *)sa2;
-
-	return nfs_sockaddr_match_ipaddr6(sa1, sa2) &&
-		(sin1->sin6_port == sin2->sin6_port);
-}
-
-static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
-				const struct sockaddr *sa2)
-{
-	const struct sockaddr_in *sin1 = (const struct sockaddr_in *)sa1;
-	const struct sockaddr_in *sin2 = (const struct sockaddr_in *)sa2;
-
-	return nfs_sockaddr_match_ipaddr4(sa1, sa2) &&
-		(sin1->sin_port == sin2->sin_port);
-}
-
 #if defined(CONFIG_NFS_V4_1)
 /*
  * Test if two socket addresses represent the same actual socket,
@@ -360,16 +292,8 @@ static int nfs_sockaddr_cmp_ip4(const struct sockaddr *sa1,
 int nfs_sockaddr_match_ipaddr(const struct sockaddr *sa1,
 			      const struct sockaddr *sa2)
 {
-	if (sa1->sa_family != sa2->sa_family)
-		return 0;
-
-	switch (sa1->sa_family) {
-	case AF_INET:
-		return nfs_sockaddr_match_ipaddr4(sa1, sa2);
-	case AF_INET6:
-		return nfs_sockaddr_match_ipaddr6(sa1, sa2);
-	}
-	return 0;
+	return inet_addr_equal((const union inet_addr *)sa1,
+			       (const union inet_addr *)sa2);
 }
 EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
 #endif /* CONFIG_NFS_V4_1 */
@@ -381,16 +305,8 @@ EXPORT_SYMBOL_GPL(nfs_sockaddr_match_ipaddr);
 static int nfs_sockaddr_cmp(const struct sockaddr *sa1,
 			    const struct sockaddr *sa2)
 {
-	if (sa1->sa_family != sa2->sa_family)
-		return 0;
-
-	switch (sa1->sa_family) {
-	case AF_INET:
-		return nfs_sockaddr_cmp_ip4(sa1, sa2);
-	case AF_INET6:
-		return nfs_sockaddr_cmp_ip6(sa1, sa2);
-	}
-	return 0;
+	return inet_addr_equal_strict((union inet_addr *)sa1,
+				      (union inet_addr *)sa2);
 }
 
 /*
diff --git a/fs/nfs/nfs4filelayoutdev.c b/fs/nfs/nfs4filelayoutdev.c
index 661a0f6..6509160 100644
--- a/fs/nfs/nfs4filelayoutdev.c
+++ b/fs/nfs/nfs4filelayoutdev.c
@@ -32,6 +32,7 @@
 #include <linux/vmalloc.h>
 #include <linux/module.h>
 #include <linux/sunrpc/addr.h>
+#include <net/inet_addr.h>
 
 #include "internal.h"
 #include "nfs4session.h"
@@ -74,44 +75,14 @@ print_ds(struct nfs4_pnfs_ds *ds)
 static bool
 same_sockaddr(struct sockaddr *addr1, struct sockaddr *addr2)
 {
-	struct sockaddr_in *a, *b;
-	struct sockaddr_in6 *a6, *b6;
-
-	if (addr1->sa_family != addr2->sa_family)
-		return false;
-
-	switch (addr1->sa_family) {
-	case AF_INET:
-		a = (struct sockaddr_in *)addr1;
-		b = (struct sockaddr_in *)addr2;
-
-		if (a->sin_addr.s_addr == b->sin_addr.s_addr &&
-		    a->sin_port == b->sin_port)
-			return true;
-		break;
-
-	case AF_INET6:
-		a6 = (struct sockaddr_in6 *)addr1;
-		b6 = (struct sockaddr_in6 *)addr2;
-
-		/* LINKLOCAL addresses must have matching scope_id */
-		if (ipv6_addr_scope(&a6->sin6_addr) ==
-		    IPV6_ADDR_SCOPE_LINKLOCAL &&
-		    a6->sin6_scope_id != b6->sin6_scope_id)
-			return false;
-
-		if (ipv6_addr_equal(&a6->sin6_addr, &b6->sin6_addr) &&
-		    a6->sin6_port == b6->sin6_port)
-			return true;
-		break;
-
-	default:
+	if (addr1->sa_family != AF_INET && addr1->sa_family != AF_INET6) {
 		dprintk("%s: unhandled address family: %u\n",
 			__func__, addr1->sa_family);
 		return false;
 	}
 
-	return false;
+	return inet_addr_equal_strict((union inet_addr *)addr1,
+				      (union inet_addr *)addr2);
 }
 
 static bool
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 2d7525f..eb58d8a 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -49,6 +49,7 @@
 #include <linux/in6.h>
 #include <linux/slab.h>
 #include <net/ipv6.h>
+#include <net/inet_addr.h>
 #include <linux/netdevice.h>
 #include <linux/nfs_xdr.h>
 #include <linux/magic.h>
@@ -2318,34 +2319,8 @@ static int nfs_compare_super_address(struct nfs_server *server1,
 
 	sap1 = (struct sockaddr *)&server1->nfs_client->cl_addr;
 	sap2 = (struct sockaddr *)&server2->nfs_client->cl_addr;
-
-	if (sap1->sa_family != sap2->sa_family)
-		return 0;
-
-	switch (sap1->sa_family) {
-	case AF_INET: {
-		struct sockaddr_in *sin1 = (struct sockaddr_in *)sap1;
-		struct sockaddr_in *sin2 = (struct sockaddr_in *)sap2;
-		if (sin1->sin_addr.s_addr != sin2->sin_addr.s_addr)
-			return 0;
-		if (sin1->sin_port != sin2->sin_port)
-			return 0;
-		break;
-	}
-	case AF_INET6: {
-		struct sockaddr_in6 *sin1 = (struct sockaddr_in6 *)sap1;
-		struct sockaddr_in6 *sin2 = (struct sockaddr_in6 *)sap2;
-		if (!ipv6_addr_equal(&sin1->sin6_addr, &sin2->sin6_addr))
-			return 0;
-		if (sin1->sin6_port != sin2->sin6_port)
-			return 0;
-		break;
-	}
-	default:
-		return 0;
-	}
-
-	return 1;
+	return inet_addr_equal_strict((union inet_addr *)sap1,
+				      (union inet_addr *)sap2);
 }
 
 static int nfs_compare_super(struct super_block *sb, void *data)
diff --git a/include/net/inet_addr.h b/include/net/inet_addr.h
index 683e904..9889c27 100644
--- a/include/net/inet_addr.h
+++ b/include/net/inet_addr.h
@@ -19,9 +19,15 @@ bool inet_addr_equal(const union inet_addr *a, const union inet_addr *b)
 {
 	if (a->sa.sa_family != b->sa.sa_family)
 		return false;
-	if (a->sa.sa_family == AF_INET6)
-		return ipv6_addr_equal(&a->sin6.sin6_addr, &b->sin6.sin6_addr);
-	else
+	if (a->sa.sa_family == AF_UNSPEC)
+		return true;
+	else if (a->sa.sa_family == AF_INET6) {
+		if (!ipv6_addr_equal(&a->sin6.sin6_addr, &b->sin6.sin6_addr))
+			return false;
+		else if (__ipv6_addr_needs_scope_id(__ipv6_addr_type(&a->sin6.sin6_addr)))
+			return a->sin6.sin6_scope_id == b->sin6.sin6_scope_id;
+		return false;
+	} else
 		return a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr;
 }
 
@@ -46,6 +52,8 @@ static inline bool inet_addr_multicast(const union inet_addr *ipa)
 static inline
 bool inet_addr_equal(const union inet_addr *a, const union inet_addr *b)
 {
+	if (a->sa.sa_family == AF_UNSPEC)
+		return a->sa.sa_family == b->sa.sa_family;
 	return a->sin.sin_addr.s_addr == b->sin.sin_addr.s_addr;
 }
 
@@ -60,6 +68,24 @@ static inline bool inet_addr_multicast(const union inet_addr *ipa)
 }
 #endif
 
+static inline
+bool inet_addr_equal_strict(const union inet_addr *a, const union inet_addr *b)
+{
+	if (inet_addr_equal(a, b)) {
+		switch (a->sa.sa_family) {
+#if IS_ENABLED(CONFIG_IPV6)
+		case AF_INET6:
+			return a->sin6.sin6_port == b->sin6.sin6_port;
+#endif
+		case AF_INET:
+			return a->sin.sin_port == b->sin.sin_port;
+		default:
+			return true;
+		}
+	} else
+		return false;
+}
+
 /**
  * inet_addr_copy - copy the address portion of one sockaddr to another
  * @dst: destination sockaddr
-- 
1.7.7.6