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/*
* 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 <linux/export.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);
}