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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]; |
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 | /* | |
142 | * Need to call dm_copy_name_and_uuid from here for now. | |
143 | * Context of previous var adds and locking used for | |
144 | * hash_cell not compatable. | |
145 | */ | |
146 | if (dm_copy_name_and_uuid(event->md, event->name, | |
147 | event->uuid)) { | |
148 | DMERR("%s: dm_copy_name_and_uuid() failed", | |
e46b272b | 149 | __func__); |
7a8c3d3b MA |
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", | |
e46b272b | 155 | __func__); |
7a8c3d3b MA |
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", | |
e46b272b | 161 | __func__); |
7a8c3d3b MA |
162 | goto uevent_free; |
163 | } | |
164 | ||
165 | r = kobject_uevent_env(kobj, event->action, event->ku_env.envp); | |
166 | if (r) | |
e46b272b | 167 | DMERR("%s: kobject_uevent_env failed", __func__); |
7a8c3d3b MA |
168 | uevent_free: |
169 | dm_uevent_free(event); | |
170 | } | |
171 | } | |
172 | EXPORT_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 | */ | |
183 | void 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)) { | |
e46b272b | 190 | DMERR("%s: Invalid event_type %d", __func__, event_type); |
7a8c3d3b MA |
191 | goto out; |
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 | goto out; | |
200 | ||
201 | dm_uevent_add(md, &event->elist); | |
202 | ||
203 | out: | |
204 | dm_put(md); | |
205 | } | |
206 | EXPORT_SYMBOL_GPL(dm_path_uevent); | |
207 | ||
51e5b2bd MA |
208 | int dm_uevent_init(void) |
209 | { | |
210 | _dm_event_cache = KMEM_CACHE(dm_uevent, 0); | |
211 | if (!_dm_event_cache) | |
212 | return -ENOMEM; | |
213 | ||
214 | DMINFO("version 1.0.3"); | |
215 | ||
216 | return 0; | |
217 | } | |
218 | ||
219 | void dm_uevent_exit(void) | |
220 | { | |
221 | kmem_cache_destroy(_dm_event_cache); | |
222 | } |