cifs: avoid use of dstaddr as key for fscache client cookie

server->dstaddr can change when the DNS mapping for the
server hostname changes. But conn_id is a u64 counter
that is incremented each time a new TCP connection
is setup. So use only that as a key.

Signed-off-by: Shyam Prasad N <sprasad@microsoft.com>
Reviewed-by: Paulo Alcantara (SUSE) <pc@cjr.nz>
Signed-off-by: Steve French <stfrench@microsoft.com>

diff --git a/fs/cifs/fscache.c b/fs/cifs/fscache.c
index 1db3437..003c5f1 100644 (file)
--- a/fs/cifs/fscache.c
+++ b/fs/cifs/fscache.c
@@ -16,14 +16,6 @@
  * Key layout of CIFS server cache index object
  */
 struct cifs_server_key {
-       struct {
-               uint16_t        family;         /* address family */
-               __be16          port;           /* IP port */
-       } hdr;
-       union {
-               struct in_addr  ipv4_addr;
-               struct in6_addr ipv6_addr;
-       };
        __u64 conn_id;
 } __packed;
 
@@ -32,11 +24,7 @@ struct cifs_server_key {
  */
 void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
 {
-       const struct sockaddr *sa = (struct sockaddr *) &server->dstaddr;
-       const struct sockaddr_in *addr = (struct sockaddr_in *) sa;
-       const struct sockaddr_in6 *addr6 = (struct sockaddr_in6 *) sa;
        struct cifs_server_key key;
-       uint16_t key_len = sizeof(key.hdr);
 
        /*
         * Check if cookie was already initialized so don't reinitialize it.
@@ -47,36 +35,12 @@ void cifs_fscache_get_client_cookie(struct TCP_Server_Info *server)
                return;
 
        memset(&key, 0, sizeof(key));
-
-       /*
-        * Should not be a problem as sin_family/sin6_family overlays
-        * sa_family field
-        */
-       key.hdr.family = sa->sa_family;
-       switch (sa->sa_family) {
-       case AF_INET:
-               key.hdr.port = addr->sin_port;
-               key.ipv4_addr = addr->sin_addr;
-               key_len += sizeof(key.ipv4_addr);
-               break;
-
-       case AF_INET6:
-               key.hdr.port = addr6->sin6_port;
-               key.ipv6_addr = addr6->sin6_addr;
-               key_len += sizeof(key.ipv6_addr);
-               break;
-
-       default:
-               cifs_dbg(VFS, "Unknown network family '%d'\n", sa->sa_family);
-               server->fscache = NULL;
-               return;
-       }
        key.conn_id = server->conn_id;
 
        server->fscache =
                fscache_acquire_cookie(cifs_fscache_netfs.primary_index,
                                       &cifs_fscache_server_index_def,
-                                      &key, key_len,
+                                      &key, sizeof(key),
                                       NULL, 0,
                                       server, 0, true);
        cifs_dbg(FYI, "%s: (0x%p/0x%p)\n",