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1// SPDX-License-Identifier: GPL-2.0-or-later2/*3 * Device Mapper Uevent Support (dm-uevent)4 *5 * Copyright IBM Corporation, 20076 * Author: Mike Anderson <andmike@linux.vnet.ibm.com>7 */8#include <linux/list.h>9#include <linux/slab.h>10#include <linux/kobject.h>11#include <linux/dm-ioctl.h>12#include <linux/export.h>13 14#include "dm.h"15#include "dm-uevent.h"16 17#define DM_MSG_PREFIX "uevent"18 19static const struct {20 enum dm_uevent_type type;21 enum kobject_action action;22 char *name;23} _dm_uevent_type_names[] = {24 {DM_UEVENT_PATH_FAILED, KOBJ_CHANGE, "PATH_FAILED"},25 {DM_UEVENT_PATH_REINSTATED, KOBJ_CHANGE, "PATH_REINSTATED"},26};27 28static struct kmem_cache *_dm_event_cache;29 30struct dm_uevent {31 struct mapped_device *md;32 enum kobject_action action;33 struct kobj_uevent_env ku_env;34 struct list_head elist;35 char name[DM_NAME_LEN];36 char uuid[DM_UUID_LEN];37};38 39static void dm_uevent_free(struct dm_uevent *event)40{41 kmem_cache_free(_dm_event_cache, event);42}43 44static struct dm_uevent *dm_uevent_alloc(struct mapped_device *md)45{46 struct dm_uevent *event;47 48 event = kmem_cache_zalloc(_dm_event_cache, GFP_ATOMIC);49 if (!event)50 return NULL;51 52 INIT_LIST_HEAD(&event->elist);53 event->md = md;54 55 return event;56}57 58static struct dm_uevent *dm_build_path_uevent(struct mapped_device *md,59 struct dm_target *ti,60 enum kobject_action action,61 const char *dm_action,62 const char *path,63 unsigned int nr_valid_paths)64{65 struct dm_uevent *event;66 67 event = dm_uevent_alloc(md);68 if (!event) {69 DMERR("%s: dm_uevent_alloc() failed", __func__);70 goto err_nomem;71 }72 73 event->action = action;74 75 if (add_uevent_var(&event->ku_env, "DM_TARGET=%s", ti->type->name)) {76 DMERR("%s: add_uevent_var() for DM_TARGET failed",77 __func__);78 goto err_add;79 }80 81 if (add_uevent_var(&event->ku_env, "DM_ACTION=%s", dm_action)) {82 DMERR("%s: add_uevent_var() for DM_ACTION failed",83 __func__);84 goto err_add;85 }86 87 if (add_uevent_var(&event->ku_env, "DM_SEQNUM=%u",88 dm_next_uevent_seq(md))) {89 DMERR("%s: add_uevent_var() for DM_SEQNUM failed",90 __func__);91 goto err_add;92 }93 94 if (add_uevent_var(&event->ku_env, "DM_PATH=%s", path)) {95 DMERR("%s: add_uevent_var() for DM_PATH failed", __func__);96 goto err_add;97 }98 99 if (add_uevent_var(&event->ku_env, "DM_NR_VALID_PATHS=%d",100 nr_valid_paths)) {101 DMERR("%s: add_uevent_var() for DM_NR_VALID_PATHS failed",102 __func__);103 goto err_add;104 }105 106 return event;107 108err_add:109 dm_uevent_free(event);110err_nomem:111 return ERR_PTR(-ENOMEM);112}113 114/**115 * dm_send_uevents - send uevents for given list116 *117 * @events: list of events to send118 * @kobj: kobject generating event119 *120 */121void dm_send_uevents(struct list_head *events, struct kobject *kobj)122{123 int r;124 struct dm_uevent *event, *next;125 126 list_for_each_entry_safe(event, next, events, elist) {127 list_del_init(&event->elist);128 129 /*130 * When a device is being removed this copy fails and we131 * discard these unsent events.132 */133 if (dm_copy_name_and_uuid(event->md, event->name,134 event->uuid)) {135 DMINFO("%s: skipping sending uevent for lost device",136 __func__);137 goto uevent_free;138 }139 140 if (add_uevent_var(&event->ku_env, "DM_NAME=%s", event->name)) {141 DMERR("%s: add_uevent_var() for DM_NAME failed",142 __func__);143 goto uevent_free;144 }145 146 if (add_uevent_var(&event->ku_env, "DM_UUID=%s", event->uuid)) {147 DMERR("%s: add_uevent_var() for DM_UUID failed",148 __func__);149 goto uevent_free;150 }151 152 r = kobject_uevent_env(kobj, event->action, event->ku_env.envp);153 if (r)154 DMERR("%s: kobject_uevent_env failed", __func__);155uevent_free:156 dm_uevent_free(event);157 }158}159EXPORT_SYMBOL_GPL(dm_send_uevents);160 161/**162 * dm_path_uevent - called to create a new path event and queue it163 *164 * @event_type: path event type enum165 * @ti: pointer to a dm_target166 * @path: string containing pathname167 * @nr_valid_paths: number of valid paths remaining168 *169 */170void dm_path_uevent(enum dm_uevent_type event_type, struct dm_target *ti,171 const char *path, unsigned int nr_valid_paths)172{173 struct mapped_device *md = dm_table_get_md(ti->table);174 struct dm_uevent *event;175 176 if (event_type >= ARRAY_SIZE(_dm_uevent_type_names)) {177 DMERR("%s: Invalid event_type %d", __func__, event_type);178 return;179 }180 181 event = dm_build_path_uevent(md, ti,182 _dm_uevent_type_names[event_type].action,183 _dm_uevent_type_names[event_type].name,184 path, nr_valid_paths);185 if (IS_ERR(event))186 return;187 188 dm_uevent_add(md, &event->elist);189}190EXPORT_SYMBOL_GPL(dm_path_uevent);191 192int dm_uevent_init(void)193{194 _dm_event_cache = KMEM_CACHE(dm_uevent, 0);195 if (!_dm_event_cache)196 return -ENOMEM;197 198 DMINFO("version 1.0.3");199 200 return 0;201}202 203void dm_uevent_exit(void)204{205 kmem_cache_destroy(_dm_event_cache);206}207