Root/drivers/md/dm-uevent.c

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>
24#include <linux/dm-ioctl.h>
25#include <linux/export.h>
26
27#include "dm.h"
28#include "dm-uevent.h"
29
30#define DM_MSG_PREFIX "uevent"
31
32static const struct {
33    enum dm_uevent_type type;
34    enum kobject_action action;
35    char *name;
36} _dm_uevent_type_names[] = {
37    {DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},
38    {DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},
39};
40
41static struct kmem_cache *_dm_event_cache;
42
43struct dm_uevent {
44    struct mapped_device *md;
45    enum kobject_action action;
46    struct kobj_uevent_env ku_env;
47    struct list_head elist;
48    char name[DM_NAME_LEN];
49    char uuid[DM_UUID_LEN];
50};
51
52static void dm_uevent_free(struct dm_uevent *event)
53{
54    kmem_cache_free(_dm_event_cache, event);
55}
56
57static struct dm_uevent *dm_uevent_alloc(struct mapped_device *md)
58{
59    struct dm_uevent *event;
60
61    event = kmem_cache_zalloc(_dm_event_cache, GFP_ATOMIC);
62    if (!event)
63        return NULL;
64
65    INIT_LIST_HEAD(&event->elist);
66    event->md = md;
67
68    return event;
69}
70
71static struct dm_uevent *dm_build_path_uevent(struct mapped_device *md,
72                          struct dm_target *ti,
73                          enum kobject_action action,
74                          const char *dm_action,
75                          const char *path,
76                          unsigned nr_valid_paths)
77{
78    struct dm_uevent *event;
79
80    event = dm_uevent_alloc(md);
81    if (!event) {
82        DMERR("%s: dm_uevent_alloc() failed", __func__);
83        goto err_nomem;
84    }
85
86    event->action = action;
87
88    if (add_uevent_var(&event->ku_env, "DM_TARGET=%s", ti->type->name)) {
89        DMERR("%s: add_uevent_var() for DM_TARGET failed",
90              __func__);
91        goto err_add;
92    }
93
94    if (add_uevent_var(&event->ku_env, "DM_ACTION=%s", dm_action)) {
95        DMERR("%s: add_uevent_var() for DM_ACTION failed",
96              __func__);
97        goto err_add;
98    }
99
100    if (add_uevent_var(&event->ku_env, "DM_SEQNUM=%u",
101               dm_next_uevent_seq(md))) {
102        DMERR("%s: add_uevent_var() for DM_SEQNUM failed",
103              __func__);
104        goto err_add;
105    }
106
107    if (add_uevent_var(&event->ku_env, "DM_PATH=%s", path)) {
108        DMERR("%s: add_uevent_var() for DM_PATH failed", __func__);
109        goto err_add;
110    }
111
112    if (add_uevent_var(&event->ku_env, "DM_NR_VALID_PATHS=%d",
113               nr_valid_paths)) {
114        DMERR("%s: add_uevent_var() for DM_NR_VALID_PATHS failed",
115              __func__);
116        goto err_add;
117    }
118
119    return event;
120
121err_add:
122    dm_uevent_free(event);
123err_nomem:
124    return ERR_PTR(-ENOMEM);
125}
126
127/**
128 * dm_send_uevents - send uevents for given list
129 *
130 * @events: list of events to send
131 * @kobj: kobject generating event
132 *
133 */
134void dm_send_uevents(struct list_head *events, struct kobject *kobj)
135{
136    int r;
137    struct dm_uevent *event, *next;
138
139    list_for_each_entry_safe(event, next, events, elist) {
140        list_del_init(&event->elist);
141
142        /*
143         * When a device is being removed this copy fails and we
144         * discard these unsent events.
145         */
146        if (dm_copy_name_and_uuid(event->md, event->name,
147                      event->uuid)) {
148            DMINFO("%s: skipping sending uevent for lost device",
149                   __func__);
150            goto uevent_free;
151        }
152
153        if (add_uevent_var(&event->ku_env, "DM_NAME=%s", event->name)) {
154            DMERR("%s: add_uevent_var() for DM_NAME failed",
155                  __func__);
156            goto uevent_free;
157        }
158
159        if (add_uevent_var(&event->ku_env, "DM_UUID=%s", event->uuid)) {
160            DMERR("%s: add_uevent_var() for DM_UUID failed",
161                  __func__);
162            goto uevent_free;
163        }
164
165        r = kobject_uevent_env(kobj, event->action, event->ku_env.envp);
166        if (r)
167            DMERR("%s: kobject_uevent_env failed", __func__);
168uevent_free:
169        dm_uevent_free(event);
170    }
171}
172EXPORT_SYMBOL_GPL(dm_send_uevents);
173
174/**
175 * dm_path_uevent - called to create a new path event and queue it
176 *
177 * @event_type: path event type enum
178 * @ti: pointer to a dm_target
179 * @path: string containing pathname
180 * @nr_valid_paths: number of valid paths remaining
181 *
182 */
183void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,
184           const char *path, unsigned nr_valid_paths)
185{
186    struct mapped_device *md = dm_table_get_md(ti->table);
187    struct dm_uevent *event;
188
189    if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {
190        DMERR("%s: Invalid event_type %d", __func__, event_type);
191        return;
192    }
193
194    event = dm_build_path_uevent(md, ti,
195                     _dm_uevent_type_names[event_type].action,
196                     _dm_uevent_type_names[event_type].name,
197                     path, nr_valid_paths);
198    if (IS_ERR(event))
199        return;
200
201    dm_uevent_add(md, &event->elist);
202}
203EXPORT_SYMBOL_GPL(dm_path_uevent);
204
205int dm_uevent_init(void)
206{
207    _dm_event_cache = KMEM_CACHE(dm_uevent, 0);
208    if (!_dm_event_cache)
209        return -ENOMEM;
210
211    DMINFO("version 1.0.3");
212
213    return 0;
214}
215
216void dm_uevent_exit(void)
217{
218    kmem_cache_destroy(_dm_event_cache);
219}
220

Archive Download this file

Branches:
ben-wpan
ben-wpan-stefan
javiroman/ks7010
jz-2.6.34
jz-2.6.34-rc5
jz-2.6.34-rc6
jz-2.6.34-rc7
jz-2.6.35
jz-2.6.36
jz-2.6.37
jz-2.6.38
jz-2.6.39
jz-3.0
jz-3.1
jz-3.11
jz-3.12
jz-3.13
jz-3.15
jz-3.16
jz-3.18-dt
jz-3.2
jz-3.3
jz-3.4
jz-3.5
jz-3.6
jz-3.6-rc2-pwm
jz-3.9
jz-3.9-clk
jz-3.9-rc8
jz47xx
jz47xx-2.6.38
master

Tags:
od-2011-09-04
od-2011-09-18
v2.6.34-rc5
v2.6.34-rc6
v2.6.34-rc7
v3.9



interactive