From: dwysocha@redhat.com <dwysocha@redhat.com>
Date: Tue, 18 Dec 2007 23:47:57 -0500
Subject: [md] dm: add uevent to core
Message-id: 20071219044941.209749373@redhat.com
O-Subject: [RHEL5.2 PATCH 3/5] bz#184778: dm - add uevent to core
Bugzilla: 184778

This patch adds a dm-uevent skeleton support to the Makefile, and the dm
directory.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Dave Wysochanski <dwysocha@redhat.com>

Acked-by: Alasdair G Kergon <agk@redhat.com>

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index cc1d85b..5c85d54 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -261,5 +261,11 @@ config DM_MULTIPATH_HP
         ---help---
           Multipath support for HP MSA (Active/Passive) series hardware.
 
+ config DM_UEVENT
+ 	bool "DM uevents (EXPERIMENTAL)"
+ 	depends on BLK_DEV_DM && EXPERIMENTAL
+ 	---help---
+ 	Generate udev events for DM events.
+
 endmenu
 
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index db54992..fd566c0 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -49,6 +49,10 @@ ifeq ($(CONFIG_ALTIVEC),y)
 altivec_flags := -maltivec -mabi=altivec
 endif
 
+ifeq ($(CONFIG_DM_UEVENT),y)
+dm-mod-objs			+= dm-uevent.o
+endif
+
 targets += raid6int1.c
 $(obj)/raid6int1.c:   UNROLL := 1
 $(obj)/raid6int1.c:   $(src)/raid6int.uc $(src)/unroll.pl FORCE
diff --git a/drivers/md/dm-uevent.c b/drivers/md/dm-uevent.c
new file mode 100644
index 0000000..7d8e9c9
--- /dev/null
+++ b/drivers/md/dm-uevent.c
@@ -0,0 +1,74 @@
+/*
+ * Device Mapper Uevent Support (dm-uevent)
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2007
+ * 	Author: Mike Anderson <andmike@linux.vnet.ibm.com>
+ */
+#include <linux/list.h>
+#include <linux/slab.h>
+#include <linux/kobject.h>
+
+#include "dm.h"
+#include "dm-uevent.h"
+
+#define DM_MSG_PREFIX "uevent"
+
+static struct kmem_cache *_dm_event_cache;
+
+struct dm_uevent {
+	struct mapped_device *md;
+	enum kobject_action action;
+	struct kobj_uevent_env ku_env;
+	struct list_head elist;
+};
+
+static void dm_uevent_free(struct dm_uevent *event)
+{
+	kmem_cache_free(_dm_event_cache, event);
+}
+
+static struct dm_uevent *dm_uevent_alloc(struct mapped_device *md)
+{
+	struct dm_uevent *event;
+
+	event = kmem_cache_zalloc(_dm_event_cache, GFP_ATOMIC);
+	if (!event)
+		return NULL;
+
+	INIT_LIST_HEAD(&event->elist);
+	event->md = md;
+
+	return event;
+}
+
+int dm_uevent_init(void)
+{
+	_dm_event_cache = kmem_cache_create("dm_uevent",
+					    sizeof(struct dm_uevent),
+					    0, 0, NULL, NULL);
+	if (!_dm_event_cache)
+		return -ENOMEM;
+
+	DMINFO("version 1.0.3");
+
+	return 0;
+}
+
+void dm_uevent_exit(void)
+{
+	kmem_cache_destroy(_dm_event_cache);
+}
diff --git a/drivers/md/dm-uevent.h b/drivers/md/dm-uevent.h
new file mode 100644
index 0000000..9d77683
--- /dev/null
+++ b/drivers/md/dm-uevent.h
@@ -0,0 +1,41 @@
+/*
+ * Device Mapper Uevent Support
+ *
+ * This program is free software; you can redistribute it and/or modify it
+ * under the terms of the GNU General Public License as published by the
+ * Free Software Foundation; either version 2 of the License, or (at your
+ * option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful, but
+ * WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+ * General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License along
+ * with this program; if not, write to the Free Software Foundation, Inc.,
+ * 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
+ *
+ * Copyright IBM Corporation, 2007
+ * 	Author: Mike Anderson <andmike@linux.vnet.ibm.com>
+ */
+#ifndef DM_UEVENT_H
+#define DM_UEVENT_H
+
+#ifdef CONFIG_DM_UEVENT
+
+extern int dm_uevent_init(void);
+extern void dm_uevent_exit(void);
+
+#else
+
+static inline int dm_uevent_init(void)
+{
+	return 0;
+}
+static inline void dm_uevent_exit(void)
+{
+}
+
+#endif	/* CONFIG_DM_UEVENT */
+
+#endif	/* DM_UEVENT_H */
diff --git a/drivers/md/dm.c b/drivers/md/dm.c
index e346c45..3c94b55 100644
--- a/drivers/md/dm.c
+++ b/drivers/md/dm.c
@@ -7,6 +7,7 @@
 
 #include "dm.h"
 #include "dm-bio-list.h"
+#include "dm-uevent.h"
 
 #include <linux/init.h>
 #include <linux/module.h>
@@ -145,11 +146,19 @@ static int __init local_init(void)
 		return -ENOMEM;
 	}
 
+	r = dm_uevent_init();
+	if (r) {
+		kmem_cache_destroy(_tio_cache);
+		kmem_cache_destroy(_io_cache);
+		return r;
+	}
+
 	_major = major;
 	r = register_blkdev(_major, _name);
 	if (r < 0) {
 		kmem_cache_destroy(_tio_cache);
 		kmem_cache_destroy(_io_cache);
+		dm_uevent_exit();
 		return r;
 	}
 
@@ -166,6 +175,7 @@ static void local_exit(void)
 
 	if (unregister_blkdev(_major, _name) < 0)
 		DMERR("unregister_blkdev failed");
+	dm_uevent_exit();
 
 	_major = 0;