cifs: define server-level cache index objects and register them

Define server-level cache index objects (as managed by TCP_ServerInfo structs)
and register then with FS-Cache. Each server object is created in the CIFS
top-level index object and is itself an index into which superblock-level
objects are inserted.

The server objects are now keyed by {IPaddress,family,port} tuple.

Signed-off-by: Suresh Jayaraman <sjayaraman@suse.de>
Signed-off-by: Steve French <sfrench@us.ibm.com>

1 files changed, 62 insertions, 0 deletions

diff --git a/fs/cifs/cache.c b/fs/cifs/cache.c
index 1cb5ffb..f46468f 100644
--- a/fs/cifs/cache.c
+++ b/fs/cifs/cache.c
@@ -19,6 +19,7 @@
  *   Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
  */
 #include "fscache.h"
+#include "cifs_debug.h"
 
 /*
  * CIFS filesystem definition for FS-Cache
@@ -44,3 +45,64 @@ void cifs_fscache_unregister(void)
 	fscache_unregister_netfs(&cifs_fscache_netfs);
 }
 
+/*
+ * Key layout of CIFS server cache index object
+ */
+struct cifs_server_key {
+	uint16_t	family;		/* address family */
+	uint16_t	port;		/* IP port */
+	union {
+		struct in_addr	ipv4_addr;
+		struct in6_addr	ipv6_addr;
+	} addr[0];
+};
+
+/*
+ * Server object keyed by {IPaddress,port,family} tuple
+ */
+static uint16_t cifs_server_get_key(const void *cookie_netfs_data,
+				   void *buffer, uint16_t maxbuf)
+{
+	const struct TCP_Server_Info *server = cookie_netfs_data;
+	const struct sockaddr *sa = (struct sockaddr *) &server->addr.sockAddr;
+	struct cifs_server_key *key = buffer;
+	uint16_t key_len = sizeof(struct cifs_server_key);
+
+	memset(key, 0, key_len);
+
+	/*
+	 * Should not be a problem as sin_family/sin6_family overlays
+	 * sa_family field
+	 */
+	switch (sa->sa_family) {
+	case AF_INET:
+		key->family = server->addr.sockAddr.sin_family;
+		key->port = server->addr.sockAddr.sin_port;
+		key->addr[0].ipv4_addr = server->addr.sockAddr.sin_addr;
+		key_len += sizeof(key->addr[0].ipv4_addr);
+		break;
+
+	case AF_INET6:
+		key->family = server->addr.sockAddr6.sin6_family;
+		key->port = server->addr.sockAddr6.sin6_port;
+		key->addr[0].ipv6_addr = server->addr.sockAddr6.sin6_addr;
+		key_len += sizeof(key->addr[0].ipv6_addr);
+		break;
+
+	default:
+		cERROR(1, "CIFS: Unknown network family '%d'", sa->sa_family);
+		key_len = 0;
+		break;
+	}
+
+	return key_len;
+}
+
+/*
+ * Server object for FS-Cache
+ */
+const struct fscache_cookie_def cifs_fscache_server_index_def = {
+	.name = "CIFS.server",
+	.type = FSCACHE_COOKIE_TYPE_INDEX,
+	.get_key = cifs_server_get_key,
+};