[dm-devel] [PATCH 1/4] Subject: dm: add uevent skeleton support

[Mike Anderson]

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

Signed-off-by: Mike Anderson <andmike at linux.vnet.ibm.com>
---

 drivers/md/Kconfig     |    6 ++++
 drivers/md/Makefile    |    4 +++
 drivers/md/dm-uevent.c |   72 ++++++++++++++++++++++++++++++++++++++++++++++++
 drivers/md/dm-uevent.h |   41 +++++++++++++++++++++++++++
 drivers/md/dm.c        |   10 +++++++
 5 files changed, 133 insertions(+), 0 deletions(-)

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index 34a8c60..cdb7acb 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -276,4 +276,10 @@ config DM_DELAY
 
 	If unsure, say N.
 
+config DM_UEVENT
+	bool "DM uevents (EXPERIMENTAL)"
+	depends on BLK_DEV_DM && EXPERIMENTAL
+	---help---
+	Generate udev events for DM events.
+
 endif # MD
diff --git a/drivers/md/Makefile b/drivers/md/Makefile
index c49366c..299b8ff 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -48,6 +48,10 @@ 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..56f56bb
--- /dev/null
+++ b/drivers/md/dm-uevent.c
@@ -0,0 +1,72 @@
+/*
+ * 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 at 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 *_dme_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 *evt)
+{
+	kmem_cache_free(_dme_cache, evt);
+}
+
+static struct dm_uevent *dm_uevent_alloc(struct mapped_device *md)
+{
+	struct dm_uevent *evt;
+
+	evt = kmem_cache_zalloc(_dme_cache, GFP_ATOMIC);
+	if (!evt)
+		return NULL;
+
+	INIT_LIST_HEAD(&evt->elist);
+	evt->md = md;
+
+	return evt;
+}
+
+int dm_uevent_init(void)
+{
+	_dme_cache = KMEM_CACHE(dm_uevent, 0);
+	if (!_dme_cache)
+		return -ENOMEM;
+
+	DMINFO("version 1.0.2 inited");
+
+	return 0;
+}
+
+void dm_uevent_exit(void)
+{
+	kmem_cache_destroy(_dme_cache);
+}
diff --git a/drivers/md/dm-uevent.h b/drivers/md/dm-uevent.h
new file mode 100644
index 0000000..12c2069
--- /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 at 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 fa1db99..4cb8605 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>
@@ -154,11 +155,20 @@ static int __init local_init(void)
 	if (!_major)
 		_major = r;
 
+	r = dm_uevent_init();
+	if (r < 0) {
+		kmem_cache_destroy(_tio_cache);
+		kmem_cache_destroy(_io_cache);
+		unregister_blkdev(_major, _name);
+		return r;
+	}
+
 	return 0;
 }
 
 static void local_exit(void)
 {
+	dm_uevent_exit();
 	kmem_cache_destroy(_tio_cache);
 	kmem_cache_destroy(_io_cache);
 	unregister_blkdev(_major, _name);