afs: Make use of the YFS service upgrade to fully support IPv6

YFS VL servers offer an upgraded Volume Location service that can return
IPv6 addresses to fileservers and volume servers in addition to IPv4
addresses using the YFSVL.GetEndpoints operation which we should use if
it's available.

To this end:

 (1) Make rxrpc_kernel_recv_data() return the call's current service ID so
     that the caller can detect service upgrade and see what the service
     was upgraded to.

 (2) When we see a VL server address we haven't seen before, send a
     VL.GetCapabilities operation to it with the service upgrade bit set.

     If we get an upgrade to the YFS VL service, change the service ID in
     the address list for that address to use the upgraded service and set
     a flag to note that this appears to be a YFS-compatible server.

 (3) If, when a server's addresses are being looked up, we note that we
     previously detected a YFS-compatible server, then send the
     YFSVL.GetEndpoints operation rather than VL.GetAddrsU.

 (4) Build a fileserver address list from the reply of YFSVL.GetEndpoints,
     including both IPv4 and IPv6 addresses.  Volume server addresses are
     discarded.

 (5) The address list is sorted by address and port now, instead of just
     address.  This allows multiple servers on the same host sitting on
     different ports.

Signed-off-by: David Howells <dhowells@redhat.com>

1 files changed, 16 insertions, 0 deletions

diff --git a/fs/afs/afs_vl.h b/fs/afs/afs_vl.h
index 6350b417aee9..e3c4688f573b 100644
--- a/fs/afs/afs_vl.h
+++ b/fs/afs/afs_vl.h
@@ -16,6 +16,7 @@
 
 #define AFS_VL_PORT		7003	/* volume location service port */
 #define VL_SERVICE		52	/* RxRPC service ID for the Volume Location service */
+#define YFS_VL_SERVICE		2503	/* Service ID for AuriStor upgraded VL service */
 
 enum AFSVL_Operations {
 	VLGETENTRYBYID		= 503,	/* AFS Get VLDB entry by ID */
@@ -24,6 +25,8 @@ enum AFSVL_Operations {
 	VLGETENTRYBYIDU		= 526,	/* AFS Get VLDB entry by ID (UUID-variant) */
 	VLGETENTRYBYNAMEU	= 527,	/* AFS Get VLDB entry by name (UUID-variant) */
 	VLGETADDRSU		= 533,	/* AFS Get addrs for fileserver */
+	YVLGETENDPOINTS		= 64002, /* YFS Get endpoints for file/volume server */
+	VLGETCAPABILITIES	= 65537, /* AFS Get server capabilities */
 };
 
 enum AFSVL_Errors {
@@ -57,6 +60,19 @@ enum AFSVL_Errors {
 	AFSVL_NOMEM 		= 363547,	/* malloc/realloc failed to alloc enough memory */
 };
 
+enum {
+	YFS_SERVER_INDEX	= 0,
+	YFS_SERVER_UUID		= 1,
+	YFS_SERVER_ENDPOINT	= 2,
+};
+
+enum {
+	YFS_ENDPOINT_IPV4	= 0,
+	YFS_ENDPOINT_IPV6	= 1,
+};
+
+#define YFS_MAXENDPOINTS	16
+
 /*
  * maps to "struct vldbentry" in vvl-spec.pdf
  */