afs: Calc callback expiry in op reply delivery

Calculate the callback expiration time at the point of operation reply
delivery, using the reply time queried from AF_RXRPC on that call as a
base.
Signed-off-by: David Howells <dhowells@redhat.com>

fs/afs/afs.h

@@ -68,8 +68,8 @@ typedef enum {
 } afs_callback_type_t;
 
 struct afs_callback {
+	time64_t		expires_at;	/* Time at which expires */
 	unsigned		version;	/* Callback version */
-	unsigned		expiry;		/* Time at which expires */
 	afs_callback_type_t	type;		/* Type of callback */
 };
 

fs/afs/fsclient.c

@@ -287,13 +287,19 @@ static void xdr_decode_AFSCallBack(struct afs_call *call,
 	*_bp = bp;
 }
 
-static void xdr_decode_AFSCallBack_raw(const __be32 **_bp,
+static ktime_t xdr_decode_expiry(struct afs_call *call, u32 expiry)
+{
+	return ktime_add_ns(call->reply_time, expiry * NSEC_PER_SEC);
+}
+
+static void xdr_decode_AFSCallBack_raw(struct afs_call *call,
+				       const __be32 **_bp,
 				       struct afs_callback *cb)
 {
 	const __be32 *bp = *_bp;
 
 	cb->version	= ntohl(*bp++);
-	cb->expiry	= ntohl(*bp++);
+	cb->expires_at	= xdr_decode_expiry(call, ntohl(*bp++));
 	cb->type	= ntohl(*bp++);
 	*_bp = bp;
 }
@@ -440,6 +446,7 @@ int afs_fs_fetch_file_status(struct afs_fs_cursor *fc, struct afs_volsync *volsy
 	call->reply[0] = vnode;
 	call->reply[1] = volsync;
 	call->expected_version = new_inode ? 1 : vnode->status.data_version;
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -627,6 +634,7 @@ static int afs_fs_fetch_data64(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
 	call->expected_version = vnode->status.data_version;
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -672,6 +680,7 @@ int afs_fs_fetch_data(struct afs_fs_cursor *fc, struct afs_read *req)
 	call->reply[1] = NULL; /* volsync */
 	call->reply[2] = req;
 	call->expected_version = vnode->status.data_version;
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -714,7 +723,7 @@ static int afs_deliver_fs_create_vnode(struct afs_call *call)
 				&call->expected_version, NULL);
 	if (ret < 0)
 		return ret;
-	xdr_decode_AFSCallBack_raw(&bp, call->reply[3]);
+	xdr_decode_AFSCallBack_raw(call, &bp, call->reply[3]);
 	/* xdr_decode_AFSVolSync(&bp, call->reply[X]); */
 
 	_leave(" = 0 [done]");
@@ -773,6 +782,7 @@ int afs_fs_create(struct afs_fs_cursor *fc,
 	call->reply[2] = newstatus;
 	call->reply[3] = newcb;
 	call->expected_version = current_data_version + 1;
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -2042,7 +2052,7 @@ static int afs_deliver_fs_fetch_status(struct afs_call *call)
 				&call->expected_version, NULL);
 	if (ret < 0)
 		return ret;
-	xdr_decode_AFSCallBack_raw(&bp, callback);
+	xdr_decode_AFSCallBack_raw(call, &bp, callback);
 	if (volsync)
 		xdr_decode_AFSVolSync(&bp, volsync);
 
@@ -2088,6 +2098,7 @@ int afs_fs_fetch_status(struct afs_fs_cursor *fc,
 	call->reply[2] = callback;
 	call->reply[3] = volsync;
 	call->expected_version = 1; /* vnode->status.data_version */
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;
@@ -2188,7 +2199,7 @@ static int afs_deliver_fs_inline_bulk_status(struct afs_call *call)
 		bp = call->buffer;
 		callbacks = call->reply[2];
 		callbacks[call->count].version	= ntohl(bp[0]);
-		callbacks[call->count].expiry	= ntohl(bp[1]);
+		callbacks[call->count].expires_at = xdr_decode_expiry(call, ntohl(bp[1]));
 		callbacks[call->count].type	= ntohl(bp[2]);
 		statuses = call->reply[1];
 		if (call->count == 0 && vnode && statuses[0].abort_code == 0)
@@ -2261,6 +2272,7 @@ int afs_fs_inline_bulk_status(struct afs_fs_cursor *fc,
 	call->reply[2] = callbacks;
 	call->reply[3] = volsync;
 	call->count2 = nr_fids;
+	call->want_reply_time = true;
 
 	/* marshall the parameters */
 	bp = call->request;

fs/afs/inode.c

@@ -317,11 +317,11 @@ struct inode *afs_iget(struct super_block *sb, struct key *key,
 			 * didn't give us a callback) */
 			vnode->cb_version = 0;
 			vnode->cb_type = 0;
-			vnode->cb_expires_at = 0;
+			vnode->cb_expires_at = ktime_get();
 		} else {
 			vnode->cb_version = cb->version;
 			vnode->cb_type = cb->type;
-			vnode->cb_expires_at = cb->expiry;
+			vnode->cb_expires_at = cb->expires_at;
 			vnode->cb_interest = afs_get_cb_interest(cbi);
 			set_bit(AFS_VNODE_CB_PROMISED, &vnode->flags);
 		}

fs/afs/internal.h

@@ -131,6 +131,7 @@ struct afs_call {
 	bool			async;		/* T if asynchronous */
 	bool			ret_reply0;	/* T if should return reply[0] on success */
 	bool			upgrade;	/* T to request service upgrade */
+	bool			want_reply_time;	/* T if want reply_time */
 	u16			service_id;	/* Actual service ID (after upgrade) */
 	unsigned int		debug_id;	/* Trace ID */
 	u32			operation_ID;	/* operation ID for an incoming call */
@@ -144,6 +145,7 @@ struct afs_call {
 	};
 	afs_dataversion_t	expected_version; /* Updated version expected from store */
 	afs_dataversion_t	expected_version_2; /* 2nd updated version expected from store */
+	ktime_t			reply_time;	/* Time of first reply packet */
 };
 
 struct afs_call_type {

fs/afs/rxrpc.c

@@ -499,6 +499,12 @@ static void afs_deliver_to_call(struct afs_call *call)
 			return;
 		}
 
+		if (call->want_reply_time &&
+		    rxrpc_kernel_get_reply_time(call->net->socket,
+						call->rxcall,
+						&call->reply_time))
+			call->want_reply_time = false;
+
 		ret = call->type->deliver(call);
 		state = READ_ONCE(call->state);
 		switch (ret) {