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1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * raid_class.c - implementation of a simple raid visualisation class
4 *
5 * Copyright (c) 2005 - James Bottomley <[email protected]>
6 *
7 * This class is designed to allow raid attributes to be visualised and
8 * manipulated in a form independent of the underlying raid. Ultimately this
9 * should work for both hardware and software raids.
10 */
11#include <linux/init.h>
12#include <linux/module.h>
13#include <linux/list.h>
14#include <linux/slab.h>
15#include <linux/string.h>
16#include <linux/raid_class.h>
17#include <scsi/scsi_device.h>
18#include <scsi/scsi_host.h>
19
20#define RAID_NUM_ATTRS 3
21
22struct raid_internal {
23 struct raid_template r;
24 struct raid_function_template *f;
25 /* The actual attributes */
26 struct device_attribute private_attrs[RAID_NUM_ATTRS];
27 /* The array of null terminated pointers to attributes
28 * needed by scsi_sysfs.c */
29 struct device_attribute *attrs[RAID_NUM_ATTRS + 1];
30};
31
32struct raid_component {
33 struct list_head node;
34 struct device dev;
35 int num;
36};
37
38#define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r)
39
40#define tc_to_raid_internal(tcont) ({ \
41 struct raid_template *r = \
42 container_of(tcont, struct raid_template, raid_attrs); \
43 to_raid_internal(r); \
44})
45
46#define ac_to_raid_internal(acont) ({ \
47 struct transport_container *tc = \
48 container_of(acont, struct transport_container, ac); \
49 tc_to_raid_internal(tc); \
50})
51
52#define device_to_raid_internal(dev) ({ \
53 struct attribute_container *ac = \
54 attribute_container_classdev_to_container(dev); \
55 ac_to_raid_internal(ac); \
56})
57
58
59static int raid_match(struct attribute_container *cont, struct device *dev)
60{
61 /* We have to look for every subsystem that could house
62 * emulated RAID devices, so start with SCSI */
63 struct raid_internal *i = ac_to_raid_internal(cont);
64
65 if (IS_ENABLED(CONFIG_SCSI) && scsi_is_sdev_device(dev)) {
66 struct scsi_device *sdev = to_scsi_device(dev);
67
68 if (i->f->cookie != sdev->host->hostt)
69 return 0;
70
71 return i->f->is_raid(dev);
72 }
73 /* FIXME: look at other subsystems too */
74 return 0;
75}
76
77static int raid_setup(struct transport_container *tc, struct device *dev,
78 struct device *cdev)
79{
80 struct raid_data *rd;
81
82 BUG_ON(dev_get_drvdata(cdev));
83
84 rd = kzalloc_obj(*rd);
85 if (!rd)
86 return -ENOMEM;
87
88 INIT_LIST_HEAD(&rd->component_list);
89 dev_set_drvdata(cdev, rd);
90
91 return 0;
92}
93
94static int raid_remove(struct transport_container *tc, struct device *dev,
95 struct device *cdev)
96{
97 struct raid_data *rd = dev_get_drvdata(cdev);
98 struct raid_component *rc, *next;
99 dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
100 dev_set_drvdata(cdev, NULL);
101 list_for_each_entry_safe(rc, next, &rd->component_list, node) {
102 list_del(&rc->node);
103 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n");
104 device_unregister(&rc->dev);
105 }
106 dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
107 kfree(rd);
108 return 0;
109}
110
111static DECLARE_TRANSPORT_CLASS(raid_class,
112 "raid_devices",
113 raid_setup,
114 raid_remove,
115 NULL);
116
117static const struct {
118 enum raid_state value;
119 char *name;
120} raid_states[] = {
121 { RAID_STATE_UNKNOWN, "unknown" },
122 { RAID_STATE_ACTIVE, "active" },
123 { RAID_STATE_DEGRADED, "degraded" },
124 { RAID_STATE_RESYNCING, "resyncing" },
125 { RAID_STATE_OFFLINE, "offline" },
126};
127
128static const char *raid_state_name(enum raid_state state)
129{
130 int i;
131 char *name = NULL;
132
133 for (i = 0; i < ARRAY_SIZE(raid_states); i++) {
134 if (raid_states[i].value == state) {
135 name = raid_states[i].name;
136 break;
137 }
138 }
139 return name;
140}
141
142static struct {
143 enum raid_level value;
144 char *name;
145} raid_levels[] = {
146 { RAID_LEVEL_UNKNOWN, "unknown" },
147 { RAID_LEVEL_LINEAR, "linear" },
148 { RAID_LEVEL_0, "raid0" },
149 { RAID_LEVEL_1, "raid1" },
150 { RAID_LEVEL_10, "raid10" },
151 { RAID_LEVEL_1E, "raid1e" },
152 { RAID_LEVEL_3, "raid3" },
153 { RAID_LEVEL_4, "raid4" },
154 { RAID_LEVEL_5, "raid5" },
155 { RAID_LEVEL_50, "raid50" },
156 { RAID_LEVEL_6, "raid6" },
157 { RAID_LEVEL_JBOD, "jbod" },
158};
159
160static const char *raid_level_name(enum raid_level level)
161{
162 int i;
163 char *name = NULL;
164
165 for (i = 0; i < ARRAY_SIZE(raid_levels); i++) {
166 if (raid_levels[i].value == level) {
167 name = raid_levels[i].name;
168 break;
169 }
170 }
171 return name;
172}
173
174#define raid_attr_show_internal(attr, fmt, var, code) \
175static ssize_t raid_show_##attr(struct device *dev, \
176 struct device_attribute *attr, \
177 char *buf) \
178{ \
179 struct raid_data *rd = dev_get_drvdata(dev); \
180 code \
181 return snprintf(buf, 20, #fmt "\n", var); \
182}
183
184#define raid_attr_ro_states(attr, states, code) \
185raid_attr_show_internal(attr, %s, name, \
186 const char *name; \
187 code \
188 name = raid_##states##_name(rd->attr); \
189) \
190static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
191
192
193#define raid_attr_ro_internal(attr, code) \
194raid_attr_show_internal(attr, %d, rd->attr, code) \
195static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
196
197#define ATTR_CODE(attr) \
198 struct raid_internal *i = device_to_raid_internal(dev); \
199 if (i->f->get_##attr) \
200 i->f->get_##attr(dev->parent);
201
202#define raid_attr_ro(attr) raid_attr_ro_internal(attr, )
203#define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr))
204#define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, )
205#define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
206
207
208raid_attr_ro_state(level);
209raid_attr_ro_fn(resync);
210raid_attr_ro_state_fn(state);
211
212struct raid_template *
213raid_class_attach(struct raid_function_template *ft)
214{
215 struct raid_internal *i = kzalloc_obj(struct raid_internal);
216 int count = 0;
217
218 if (unlikely(!i))
219 return NULL;
220
221 i->f = ft;
222
223 i->r.raid_attrs.ac.class = &raid_class.class;
224 i->r.raid_attrs.ac.match = raid_match;
225 i->r.raid_attrs.ac.attrs = &i->attrs[0];
226
227 attribute_container_register(&i->r.raid_attrs.ac);
228
229 i->attrs[count++] = &dev_attr_level;
230 i->attrs[count++] = &dev_attr_resync;
231 i->attrs[count++] = &dev_attr_state;
232
233 i->attrs[count] = NULL;
234 BUG_ON(count > RAID_NUM_ATTRS);
235
236 return &i->r;
237}
238EXPORT_SYMBOL(raid_class_attach);
239
240void
241raid_class_release(struct raid_template *r)
242{
243 struct raid_internal *i = to_raid_internal(r);
244
245 BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac));
246
247 kfree(i);
248}
249EXPORT_SYMBOL(raid_class_release);
250
251static __init int raid_init(void)
252{
253 return transport_class_register(&raid_class);
254}
255
256static __exit void raid_exit(void)
257{
258 transport_class_unregister(&raid_class);
259}
260
261MODULE_AUTHOR("James Bottomley");
262MODULE_DESCRIPTION("RAID device class");
263MODULE_LICENSE("GPL");
264
265module_init(raid_init);
266module_exit(raid_exit);
267