svn commit: r214868 - in stable/7/sys: kern modules modules/alq

[Lawrence Stewart]

Author: lstewart
Date: Sat Nov  6 11:09:04 2010
New Revision: 214868
URL: http://svn.freebsd.org/changeset/base/214868

Log:
  MFC r205959:
  
  Add support for ALQ(9) to be compiled and loaded as a kernel module.
  
  Sponsored by:	FreeBSD Foundation
  Reviewed by:	dwmalone, jeff, rpaulo, rwatson

Added:
  stable/7/sys/modules/alq/
     - copied from r205959, head/sys/modules/alq/
Modified:
  stable/7/sys/kern/kern_alq.c
  stable/7/sys/modules/Makefile
Directory Properties:
  stable/7/sys/   (props changed)
  stable/7/sys/cddl/contrib/opensolaris/   (props changed)
  stable/7/sys/contrib/dev/acpica/   (props changed)
  stable/7/sys/contrib/pf/   (props changed)

Modified: stable/7/sys/kern/kern_alq.c
==============================================================================
--- stable/7/sys/kern/kern_alq.c	Sat Nov  6 10:54:33 2010	(r214867)
+++ stable/7/sys/kern/kern_alq.c	Sat Nov  6 11:09:04 2010	(r214868)
@@ -1,7 +1,13 @@
 /*-
  * Copyright (c) 2002, Jeffrey Roberson <jeff at freebsd.org>
+ * Copyright (c) 2008-2009, Lawrence Stewart <lstewart at freebsd.org>
+ * Copyright (c) 2009-2010, The FreeBSD Foundation
  * All rights reserved.
  *
+ * Portions of this software were developed at the Centre for Advanced
+ * Internet Architectures, Swinburne University of Technology, Melbourne,
+ * Australia by Lawrence Stewart under sponsorship from the FreeBSD Foundation.
+ *
  * Redistribution and use in source and binary forms, with or without
  * modification, are permitted provided that the following conditions
  * are met:
@@ -182,9 +188,16 @@ ald_daemon(void)
 	ALD_LOCK();
 
 	for (;;) {
-		while ((alq = LIST_FIRST(&ald_active)) == NULL)
+		while ((alq = LIST_FIRST(&ald_active)) == NULL &&
+		    !ald_shutingdown)
 			msleep(&ald_active, &ald_mtx, PWAIT, "aldslp", 0);
 
+		/* Don't shutdown until all active ALQs are flushed. */
+		if (ald_shutingdown && alq == NULL) {
+			ALD_UNLOCK();
+			break;
+		}
+
 		ALQ_LOCK(alq);
 		ald_deactivate(alq);
 		ALD_UNLOCK();
@@ -194,6 +207,8 @@ ald_daemon(void)
 			wakeup(alq);
 		ALD_LOCK();
 	}
+
+	kproc_exit(0);
 }
 
 static void
@@ -202,14 +217,29 @@ ald_shutdown(void *arg, int howto)
 	struct alq *alq;
 
 	ALD_LOCK();
+
+	/* Ensure no new queues can be created. */
 	ald_shutingdown = 1;
 
+	/* Shutdown all ALQs prior to terminating the ald_daemon. */
 	while ((alq = LIST_FIRST(&ald_queues)) != NULL) {
 		LIST_REMOVE(alq, aq_link);
 		ALD_UNLOCK();
 		alq_shutdown(alq);
 		ALD_LOCK();
 	}
+
+	/* At this point, all ALQs are flushed and shutdown. */
+
+	/*
+	 * Wake ald_daemon so that it exits. It won't be able to do
+	 * anything until we msleep because we hold the ald_mtx.
+	 */
+	wakeup(&ald_active);
+
+	/* Wait for ald_daemon to exit. */
+	msleep(ald_proc, &ald_mtx, PWAIT, "aldslp", 0);
+
 	ALD_UNLOCK();
 }
 
@@ -517,3 +547,53 @@ alq_close(struct alq *alq)
 	free(alq->aq_entbuf, M_ALD);
 	free(alq, M_ALD);
 }
+
+static int
+alq_load_handler(module_t mod, int what, void *arg)
+{
+	int ret;
+	
+	ret = 0;
+
+	switch (what) {
+	case MOD_LOAD:
+	case MOD_SHUTDOWN:
+		break;
+
+	case MOD_QUIESCE:
+		ALD_LOCK();
+		/* Only allow unload if there are no open queues. */
+		if (LIST_FIRST(&ald_queues) == NULL) {
+			ald_shutingdown = 1;
+			ALD_UNLOCK();
+			ald_shutdown(NULL, 0);
+			mtx_destroy(&ald_mtx);
+		} else {
+			ALD_UNLOCK();
+			ret = EBUSY;
+		}
+		break;
+
+	case MOD_UNLOAD:
+		/* If MOD_QUIESCE failed we must fail here too. */
+		if (ald_shutingdown == 0)
+			ret = EBUSY;
+		break;
+
+	default:
+		ret = EINVAL;
+		break;
+	}
+
+	return (ret);
+}
+
+static moduledata_t alq_mod =
+{
+	"alq",
+	alq_load_handler,
+	NULL
+};
+
+DECLARE_MODULE(alq, alq_mod, SI_SUB_SMP, SI_ORDER_ANY);
+MODULE_VERSION(alq, 1);

Modified: stable/7/sys/modules/Makefile
==============================================================================
--- stable/7/sys/modules/Makefile	Sat Nov  6 10:54:33 2010	(r214867)
+++ stable/7/sys/modules/Makefile	Sat Nov  6 11:09:04 2010	(r214868)
@@ -18,6 +18,7 @@ SUBDIR=	${_3dfx} \
 	aio \
 	alc \
 	ale \
+	alq \
 	${_amd} \
 	${_amdsbwd} \
 	${_amdtemp} \