[Patch] /proc interface

Here are some improvements to /proc/{pid}/om/where:

-Upon read, return the socket's peer address, not its own. In the
 current version, a migrated process would report the IP address of its
 home node.

-When asking an already migrated process to move to another (remote)
 node, bring it back home first. The current implementation leads to a
 crash. A direct remote->remote migration would be better, but is not 
 implemented yet.
 This change entails reordering two functions in hpc/migctrl.c, so the 
 changes look worse than they really are.

-When trying to migrate a task back home, check whether it really is
 migrated to a remote node. Failing to do so will lead to a crash.

Have a nice weekend,

A.



diff -ruNp linux-2.6-om/hpc/comm.c linux-2.6-om-work/hpc/comm.c
--- linux-2.6-om/hpc/comm.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/comm.c	2006-03-24 18:36:26.000000000 +0100
@@ -54,10 +54,11 @@ static void comm_shutdown(om_link_t *mli
 
 /**
  * comm_getname - get the name of socket
- * @mlink:	openMosix link to shutdown
+ * @mlink:	openMosix link to query
  * @address:	the sockaddr to fill
+ * @peer:	get peer name instead?
  **/
-int comm_getname(om_link_t *mlink, struct sockaddr *address)
+int comm_getname(om_link_t *mlink, struct sockaddr *address, int peer)
 {
 	struct socket *sock;
 	int val, ret;
@@ -66,7 +67,7 @@ int comm_getname(om_link_t *mlink, struc
 	sock = mlink->sock;
 	if (!sock->ops || !sock->ops->getname)
 		return -1;
-	ret = sock->ops->getname(sock, address, &val, 0);
+	ret = sock->ops->getname(sock, address, &val, peer);
 	if (ret)
 		return -1;
 	return val;
diff -ruNp linux-2.6-om/hpc/migctrl.c linux-2.6-om-work/hpc/migctrl.c
--- linux-2.6-om/hpc/migctrl.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/migctrl.c	2006-03-24 18:36:26.000000000 +0100
@@ -79,6 +79,44 @@ int task_remote_wait_expel(task_t *p)
 	return task_remote_expel(p);
 }
 
+
+/**
+ * task_local_bring - Receive task back in the deputy stub
+ * @p:		deputy task to receive
+ * @reason:	reason to send (if any)
+ **/
+static int task_local_bring(task_t *p, int reason)
+{
+	int error;
+	om_link_t *link;
+
+	if (obtain_mm(p)) {
+		printk(KERN_ERR "unable to obtain mm\n");
+		goto failed;
+	}
+
+	/* send remote request */
+	comm_send_req(p->om.contact, DEP_COMING_HOME);
+
+	/* see if other part is with on this */
+	if (mig_recv_hshake(p->om.contact))
+		goto failed;
+	
+	/* receive the process back */
+	error = mig_do_receive(p);
+	if (error)
+		goto failed;
+
+	task_clear_dflags(p, DDEPUTY);
+	link = task_set_comm(p, NULL);
+	comm_close(link);
+
+	return 0;
+failed:
+	OMBUG("failed\n");
+	return -1;
+}
+
 /**
  * task_local_send - Send a local task to remote
  * @p:		task to send
@@ -90,6 +128,14 @@ static int task_local_send(task_t *p, st
 	om_link_t *mlink;
 	int error = 0;
 
+	/* if this is a stub, bring it back first */
+	if (p->om.contact)
+	{
+		error = task_local_bring(p, reason);
+		if (error)
+			goto failed;
+	}
+
 	sockaddr_setup_port(whereto, REMOTE_DAEMON_PORT);
 	mlink = comm_setup_connect(whereto, 0);
 	if (!mlink) {
@@ -123,44 +169,6 @@ failed:
 }
 
 
-
-/**
- * task_local_bring - Receive task back in the deputy stub
- * @p:		deputy task to receive
- * @reason:	reason to send (if any)
- **/
-static int task_local_bring(task_t *p, int reason)
-{
-	int error;
-	om_link_t *link;
-
-	if (obtain_mm(p)) {
-		printk(KERN_ERR "unable to obtain mm\n");
-		goto failed;
-	}
-
-	/* send remote request */
-	comm_send_req(p->om.contact, DEP_COMING_HOME);
-
-	/* see if other part is with on this */
-	if (mig_recv_hshake(p->om.contact))
-		goto failed;
-	
-	/* receive the process back */
-	error = mig_do_receive(p);
-	if (error)
-		goto failed;
-
-	task_clear_dflags(p, DDEPUTY);
-	link = task_set_comm(p, NULL);
-	comm_close(link);
-
-	return 0;
-failed:
-	OMBUG("failed\n");
-	return -1;
-}
-
 /**
  * task_move_remote2remote - migrate a task from remote to remote
  * @p:		task to send
diff -ruNp linux-2.6-om/hpc/proc.c linux-2.6-om-work/hpc/proc.c
--- linux-2.6-om/hpc/proc.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/proc.c	2006-03-24 18:36:26.000000000 +0100
@@ -57,7 +57,7 @@ static int proc_pid_get_where(struct tas
 	struct sockaddr address;
 
 	if (p->om.contact) {
-		comm_getname(p->om.contact, &address);
+		comm_getname(p->om.contact, &address, 1);
 		length = sockaddr_to_string(&address, buf);
 		length += sprintf(buf + length, "\n");
 	} else
diff -ruNp linux-2.6-om/hpc/remote.c linux-2.6-om-work/hpc/remote.c
--- linux-2.6-om/hpc/remote.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/remote.c	2006-03-24 18:36:26.000000000 +0100
@@ -264,7 +264,7 @@ long remote_do_fork(unsigned long clone_
 	if (!childsock)
 		goto fail;
 	
-	if (comm_getname(childsock, &sa) < 0)
+	if (comm_getname(childsock, &sa, 0) < 0)
 		goto fail;
 
 	memcpy(&m.sockaddr, &sa, sizeof(struct sockaddr));
diff -ruNp linux-2.6-om/hpc/service.c linux-2.6-om-work/hpc/service.c
--- linux-2.6-om/hpc/service.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/service.c	2006-03-24 18:36:26.000000000 +0100
@@ -131,7 +131,7 @@ int sockaddr_inherit(om_link_t *mlink, s
 {
 	struct sockaddr tmp;
 	
-	if (comm_getname(mlink, &tmp) < 0)
+	if (comm_getname(mlink, &tmp, 0) < 0)
 		return -1;
 
 	memset(sa, 0, sizeof(struct sockaddr));
diff -ruNp linux-2.6-om/hpc/task.c linux-2.6-om-work/hpc/task.c
--- linux-2.6-om/hpc/task.c	2006-02-07 16:51:58.000000000 +0100
+++ linux-2.6-om-work/hpc/task.c	2006-03-24 18:36:26.000000000 +0100
@@ -130,7 +130,10 @@ void task_request_move(task_t *p)
 	addr = p->om.whereto;
 	p->om.whereto = NULL;
 	
-	task_move_to_node(p, addr, 0);
+	if (addr)
+		task_move_to_node(p, addr, 0);
+	else
+		task_go_home(p);
 	kfree(addr);
 }
 
-- 
Ansgar Esztermann
Researcher & Sysadmin
http://www2.thphy.uni-duesseldorf.de/~ansgar

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