afs: Fix the maximum lifespan of VL and probe calls

If an older AFS server doesn't support an operation, it may accept the call
and then sit on it forever, happily responding to pings that make kafs
think that the call is still alive.

Fix this by setting the maximum lifespan of Volume Location service calls
in particular and probe calls in general so that they don't run on
endlessly if they're not supported.
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/afs.h

@@ -23,6 +23,9 @@
 #define AFSPATHMAX		1024	/* Maximum length of a pathname plus NUL */
 #define AFSOPAQUEMAX		1024	/* Maximum length of an opaque field */
 
+#define AFS_VL_MAX_LIFESPAN	(120 * HZ)
+#define AFS_PROBE_MAX_LIFESPAN	(30 * HZ)
+
 typedef u64			afs_volid_t;
 typedef u64			afs_vnodeid_t;
 typedef u64			afs_dataversion_t;

fs/afs/fsclient.c

@@ -2115,6 +2115,7 @@ struct afs_call *afs_fs_get_capabilities(struct afs_net *net,
 	call->upgrade = true;
 	call->want_reply_time = true;
 	call->async = true;
+	call->max_lifespan = AFS_PROBE_MAX_LIFESPAN;
 
 	/* marshall the parameters */
 	bp = call->request;

fs/afs/internal.h

@@ -131,6 +131,7 @@ struct afs_call {
 	int			error;		/* error code */
 	u32			abort_code;	/* Remote abort ID or 0 */
 	u32			epoch;
+	unsigned int		max_lifespan;	/* Maximum lifespan to set if not 0 */
 	unsigned		request_size;	/* size of request data */
 	unsigned		reply_max;	/* maximum size of reply */
 	unsigned		first_offset;	/* offset into mapping[first] */

fs/afs/rxrpc.c

@@ -426,6 +426,10 @@ void afs_make_call(struct afs_addr_cursor *ac, struct afs_call *call, gfp_t gfp)
 
 	call->rxcall = rxcall;
 
+	if (call->max_lifespan)
+		rxrpc_kernel_set_max_life(call->net->socket, rxcall,
+					  call->max_lifespan);
+
 	/* send the request */
 	iov[0].iov_base	= call->request;
 	iov[0].iov_len	= call->request_size;

fs/afs/vlclient.c

@@ -157,6 +157,7 @@ struct afs_vldb_entry *afs_vl_get_entry_by_name_u(struct afs_vl_cursor *vc,
 	call->key = vc->key;
 	call->reply[0] = entry;
 	call->ret_reply0 = true;
+	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
 
 	/* Marshall the parameters */
 	bp = call->request;
@@ -289,6 +290,7 @@ struct afs_addr_list *afs_vl_get_addrs_u(struct afs_vl_cursor *vc,
 	call->key = vc->key;
 	call->reply[0] = NULL;
 	call->ret_reply0 = true;
+	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
 
 	/* Marshall the parameters */
 	bp = call->request;
@@ -403,6 +405,7 @@ struct afs_call *afs_vl_get_capabilities(struct afs_net *net,
 	call->upgrade = true;
 	call->want_reply_time = true;
 	call->async = true;
+	call->max_lifespan = AFS_PROBE_MAX_LIFESPAN;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -646,6 +649,7 @@ struct afs_addr_list *afs_yfsvl_get_endpoints(struct afs_vl_cursor *vc,
 	call->key = vc->key;
 	call->reply[0] = NULL;
 	call->ret_reply0 = true;
+	call->max_lifespan = AFS_VL_MAX_LIFESPAN;
 
 	/* Marshall the parameters */
 	bp = call->request;