NFS: Add support for AF_INET6 addresses in nfs_compare_super()
Refactor nfs_compare_super() and add AF_INET6 support.
Replace the generic memcmp() to document explicitly what parts of the
addresses must match in this check, and make the comparison independent
of the lengths of both addresses.
A side benefit is both tests are more computationally efficient than a
memcmp().
Signed-off-by: Chuck Lever <chuck.lever@oracle.com>
Signed-off-by: Trond Myklebust <Trond.Myklebust@netapp.com>
diff --git a/fs/nfs/super.c b/fs/nfs/super.c
index 75f3cbf..c3d8fcf 100644
--- a/fs/nfs/super.c
+++ b/fs/nfs/super.c
@@ -45,6 +45,8 @@
#include <linux/nfs_idmap.h>
#include <linux/vfs.h>
#include <linux/inet.h>
+#include <linux/in6.h>
+#include <net/ipv6.h>
#include <linux/nfs_xdr.h>
#include <linux/magic.h>
#include <linux/parser.h>
@@ -1326,15 +1328,50 @@
return ret;
}
+static int nfs_compare_super_address(struct nfs_server *server1,
+ struct nfs_server *server2)
+{
+ struct sockaddr *sap1, *sap2;
+
+ 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;
+}
+
static int nfs_compare_super(struct super_block *sb, void *data)
{
struct nfs_sb_mountdata *sb_mntdata = data;
struct nfs_server *server = sb_mntdata->server, *old = NFS_SB(sb);
int mntflags = sb_mntdata->mntflags;
- if (memcmp(&old->nfs_client->cl_addr,
- &server->nfs_client->cl_addr,
- sizeof(old->nfs_client->cl_addr)) != 0)
+ if (!nfs_compare_super_address(old, server))
return 0;
/* Note: NFS_MOUNT_UNSHARED == NFS4_MOUNT_UNSHARED */
if (old->flags & NFS_MOUNT_UNSHARED)