dm: add uevent to core

This patch adds a uevent skeleton to device-mapper.

Signed-off-by: Mike Anderson <andmike@linux.vnet.ibm.com>
Signed-off-by: Alasdair G Kergon <agk@redhat.com>

5 files changed, 133 insertions, 0 deletions

diff --git a/drivers/md/Kconfig b/drivers/md/Kconfig
index a99af8978203..9b6fbf044fd8 100644
--- a/drivers/md/Kconfig
+++ b/drivers/md/Kconfig
@@ -282,4 +282,10 @@ 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 fded842edeb1..d9aa7edb8780 100644
--- a/drivers/md/Makefile
+++ b/drivers/md/Makefile
@@ -50,6 +50,10 @@ 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 000000000000..53200c96bcb4
--- /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@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(dm_uevent, 0);
+        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 000000000000..9d776836489b
--- /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 41c9549b32ad..bb5c1eaca52b 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>
@@ -143,11 +144,19 @@ 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;
         }
 
@@ -162,6 +171,7 @@ static void local_exit(void)
         kmem_cache_destroy(_tio_cache);
         kmem_cache_destroy(_io_cache);
         unregister_blkdev(_major, _name);
+        dm_uevent_exit();
 
         _major = 0;