[net-next-2.6.git] / drivers / md / dm-uevent.c

/*
 * 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 <linux/dm-ioctl.h>

#include "dm.h"
#include "dm-uevent.h"

#define DM_MSG_PREFIX "uevent"

static const struct {
	enum dm_uevent_type type;
	enum kobject_action action;
	char *name;
} _dm_uevent_type_names[] = {
	{DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},
	{DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},
};

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;
	char name[DM_NAME_LEN];
	char uuid[DM_UUID_LEN];
};

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;
}

static struct dm_uevent *dm_build_path_uevent(struct mapped_device *md,
					      struct dm_target *ti,
					      enum kobject_action action,
					      const char *dm_action,
					      const char *path,
					      unsigned nr_valid_paths)
{
	struct dm_uevent *event;

	event = dm_uevent_alloc(md);
	if (!event) {
		DMERR("%s: dm_uevent_alloc() failed", __func__);
		goto err_nomem;
	}

	event->action = action;

	if (add_uevent_var(&event->ku_env, "DM_TARGET=%s", ti->type->name)) {
		DMERR("%s: add_uevent_var() for DM_TARGET failed",
		      __func__);
		goto err_add;
	}

	if (add_uevent_var(&event->ku_env, "DM_ACTION=%s", dm_action)) {
		DMERR("%s: add_uevent_var() for DM_ACTION failed",
		      __func__);
		goto err_add;
	}

	if (add_uevent_var(&event->ku_env, "DM_SEQNUM=%u",
			   dm_next_uevent_seq(md))) {
		DMERR("%s: add_uevent_var() for DM_SEQNUM failed",
		      __func__);
		goto err_add;
	}

	if (add_uevent_var(&event->ku_env, "DM_PATH=%s", path)) {
		DMERR("%s: add_uevent_var() for DM_PATH failed", __func__);
		goto err_add;
	}

	if (add_uevent_var(&event->ku_env, "DM_NR_VALID_PATHS=%d",
			   nr_valid_paths)) {
		DMERR("%s: add_uevent_var() for DM_NR_VALID_PATHS failed",
		      __func__);
		goto err_add;
	}

	return event;

err_add:
	dm_uevent_free(event);
err_nomem:
	return ERR_PTR(-ENOMEM);
}

/**
 * dm_send_uevents - send uevents for given list
 *
 * @events:	list of events to send
 * @kobj:	kobject generating event
 *
 */
void dm_send_uevents(struct list_head *events, struct kobject *kobj)
{
	int r;
	struct dm_uevent *event, *next;

	list_for_each_entry_safe(event, next, events, elist) {
		list_del_init(&event->elist);

		/*
		 * When a device is being removed this copy fails and we
		 * discard these unsent events.
		 */
		if (dm_copy_name_and_uuid(event->md, event->name,
					  event->uuid)) {
			DMINFO("%s: skipping sending uevent for lost device",
			       __func__);
			goto uevent_free;
		}

		if (add_uevent_var(&event->ku_env, "DM_NAME=%s", event->name)) {
			DMERR("%s: add_uevent_var() for DM_NAME failed",
			      __func__);
			goto uevent_free;
		}

		if (add_uevent_var(&event->ku_env, "DM_UUID=%s", event->uuid)) {
			DMERR("%s: add_uevent_var() for DM_UUID failed",
			      __func__);
			goto uevent_free;
		}

		r = kobject_uevent_env(kobj, event->action, event->ku_env.envp);
		if (r)
			DMERR("%s: kobject_uevent_env failed", __func__);
uevent_free:
		dm_uevent_free(event);
	}
}
EXPORT_SYMBOL_GPL(dm_send_uevents);

/**
 * dm_path_uevent - called to create a new path event and queue it
 *
 * @event_type:	path event type enum
 * @ti:			pointer to a dm_target
 * @path:		string containing pathname
 * @nr_valid_paths:	number of valid paths remaining
 *
 */
void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
		   const char *path, unsigned nr_valid_paths)
{
	struct mapped_device *md = dm_table_get_md(ti->table);
	struct dm_uevent *event;

	if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
		DMERR("%s: Invalid event_type %d", __func__, event_type);
		return;
	}

	event = dm_build_path_uevent(md, ti,
				     _dm_uevent_type_names[event_type].action,
				     _dm_uevent_type_names[event_type].name,
				     path, nr_valid_paths);
	if (IS_ERR(event))
		return;

	dm_uevent_add(md, &event->elist);
}
EXPORT_SYMBOL_GPL(dm_path_uevent);

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);
}
Commit	Line	Data
51e5b2bd MA	1	/*
	2	* Device Mapper Uevent Support (dm-uevent)
	3	*
	4	* This program is free software; you can redistribute it and/or modify it
	5	* under the terms of the GNU General Public License as published by the
	6	* Free Software Foundation; either version 2 of the License, or (at your
	7	* option) any later version.
	8	*
	9	* This program is distributed in the hope that it will be useful, but
	10	* WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
	12	* General Public License for more details.
	13	*
	14	* You should have received a copy of the GNU General Public License along
	15	* with this program; if not, write to the Free Software Foundation, Inc.,
	16	* 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
	17	*
	18	* Copyright IBM Corporation, 2007
	19	* Author: Mike Anderson <andmike@linux.vnet.ibm.com>
	20	*/
	21	#include <linux/list.h>
	22	#include <linux/slab.h>
	23	#include <linux/kobject.h>
7a8c3d3b	24	#include <linux/dm-ioctl.h>
51e5b2bd MA	25
	26	#include "dm.h"
	27	#include "dm-uevent.h"
	28
	29	#define DM_MSG_PREFIX "uevent"
	30
7a8c3d3b MA	31	static const struct {
	32	enum dm_uevent_type type;
	33	enum kobject_action action;
	34	char *name;
	35	} _dm_uevent_type_names[] = {
	36	{DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},
	37	{DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},
	38	};
	39
51e5b2bd MA	40	static struct kmem_cache *_dm_event_cache;
	41
	42	struct dm_uevent {
	43	struct mapped_device *md;
	44	enum kobject_action action;
	45	struct kobj_uevent_env ku_env;
	46	struct list_head elist;
7a8c3d3b MA	47	char name[DM_NAME_LEN];
7a8c3d3b MA	48	char uuid[DM_UUID_LEN];
51e5b2bd MA	49	};
	50
	51	static void dm_uevent_free(struct dm_uevent *event)
	52	{
	53	kmem_cache_free(_dm_event_cache, event);
	54	}
	55
	56	static struct dm_uevent dm_uevent_alloc(struct mapped_device md)
	57	{
	58	struct dm_uevent *event;
	59
	60	event = kmem_cache_zalloc(_dm_event_cache, GFP_ATOMIC);
	61	if (!event)
	62	return NULL;
	63
	64	INIT_LIST_HEAD(&event->elist);
	65	event->md = md;
	66
	67	return event;
	68	}
	69
7a8c3d3b MA	70	static struct dm_uevent dm_build_path_uevent(struct mapped_device md,
	71	struct dm_target *ti,
	72	enum kobject_action action,
	73	const char *dm_action,
	74	const char *path,
	75	unsigned nr_valid_paths)
	76	{
	77	struct dm_uevent *event;
	78
	79	event = dm_uevent_alloc(md);
	80	if (!event) {
e46b272b	81	DMERR("%s: dm_uevent_alloc() failed", __func__);
7a8c3d3b MA	82	goto err_nomem;
	83	}
	84
	85	event->action = action;
	86
	87	if (add_uevent_var(&event->ku_env, "DM_TARGET=%s", ti->type->name)) {
	88	DMERR("%s: add_uevent_var() for DM_TARGET failed",
e46b272b	89	__func__);
7a8c3d3b MA	90	goto err_add;
	91	}
	92
	93	if (add_uevent_var(&event->ku_env, "DM_ACTION=%s", dm_action)) {
	94	DMERR("%s: add_uevent_var() for DM_ACTION failed",
e46b272b	95	__func__);
7a8c3d3b MA	96	goto err_add;
	97	}
	98
	99	if (add_uevent_var(&event->ku_env, "DM_SEQNUM=%u",
	100	dm_next_uevent_seq(md))) {
	101	DMERR("%s: add_uevent_var() for DM_SEQNUM failed",
e46b272b	102	__func__);
7a8c3d3b MA	103	goto err_add;
	104	}
	105
	106	if (add_uevent_var(&event->ku_env, "DM_PATH=%s", path)) {
e46b272b	107	DMERR("%s: add_uevent_var() for DM_PATH failed", __func__);
7a8c3d3b MA	108	goto err_add;
	109	}
	110
	111	if (add_uevent_var(&event->ku_env, "DM_NR_VALID_PATHS=%d",
	112	nr_valid_paths)) {
	113	DMERR("%s: add_uevent_var() for DM_NR_VALID_PATHS failed",
e46b272b	114	__func__);
7a8c3d3b MA	115	goto err_add;
	116	}
	117
	118	return event;
	119
	120	err_add:
	121	dm_uevent_free(event);
	122	err_nomem:
	123	return ERR_PTR(-ENOMEM);
	124	}
	125
	126	/**
	127	* dm_send_uevents - send uevents for given list
	128	*
	129	* @events: list of events to send
	130	* @kobj: kobject generating event
	131	*
	132	*/
	133	void dm_send_uevents(struct list_head events, struct kobject kobj)
	134	{
	135	int r;
	136	struct dm_uevent event, next;
	137
	138	list_for_each_entry_safe(event, next, events, elist) {
	139	list_del_init(&event->elist);
	140
	141	/*
6076905b MP	142	* When a device is being removed this copy fails and we
6076905b MP	143	* discard these unsent events.
7a8c3d3b MA	144	*/
	145	if (dm_copy_name_and_uuid(event->md, event->name,
	146	event->uuid)) {
6076905b MP	147	DMINFO("%s: skipping sending uevent for lost device",
6076905b MP	148	__func__);
7a8c3d3b MA	149	goto uevent_free;
	150	}
	151
	152	if (add_uevent_var(&event->ku_env, "DM_NAME=%s", event->name)) {
	153	DMERR("%s: add_uevent_var() for DM_NAME failed",
e46b272b	154	__func__);
7a8c3d3b MA	155	goto uevent_free;
	156	}
	157
	158	if (add_uevent_var(&event->ku_env, "DM_UUID=%s", event->uuid)) {
	159	DMERR("%s: add_uevent_var() for DM_UUID failed",
e46b272b	160	__func__);
7a8c3d3b MA	161	goto uevent_free;
	162	}
	163
	164	r = kobject_uevent_env(kobj, event->action, event->ku_env.envp);
	165	if (r)
e46b272b	166	DMERR("%s: kobject_uevent_env failed", __func__);
7a8c3d3b MA	167	uevent_free:
	168	dm_uevent_free(event);
	169	}
	170	}
	171	EXPORT_SYMBOL_GPL(dm_send_uevents);
	172
	173	/**
	174	* dm_path_uevent - called to create a new path event and queue it
	175	*
	176	* @event_type: path event type enum
	177	* @ti: pointer to a dm_target
	178	* @path: string containing pathname
	179	* @nr_valid_paths: number of valid paths remaining
	180	*
	181	*/
	182	void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
	183	const char *path, unsigned nr_valid_paths)
	184	{
	185	struct mapped_device *md = dm_table_get_md(ti->table);
	186	struct dm_uevent *event;
	187
	188	if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
e46b272b	189	DMERR("%s: Invalid event_type %d", __func__, event_type);
ecdb2e25	190	return;
7a8c3d3b MA	191	}
	192
	193	event = dm_build_path_uevent(md, ti,
	194	_dm_uevent_type_names[event_type].action,
	195	_dm_uevent_type_names[event_type].name,
	196	path, nr_valid_paths);
	197	if (IS_ERR(event))
ecdb2e25	198	return;
7a8c3d3b MA	199
7a8c3d3b MA	200	dm_uevent_add(md, &event->elist);
7a8c3d3b MA	201	}
	202	EXPORT_SYMBOL_GPL(dm_path_uevent);
	203
51e5b2bd MA	204	int dm_uevent_init(void)
	205	{
	206	_dm_event_cache = KMEM_CACHE(dm_uevent, 0);
	207	if (!_dm_event_cache)
	208	return -ENOMEM;
	209
	210	DMINFO("version 1.0.3");
	211
	212	return 0;
	213	}
	214
	215	void dm_uevent_exit(void)
	216	{
	217	kmem_cache_destroy(_dm_event_cache);
	218	}