GNU Linux-libre 5.19-rc6-gnu
[releases.git] / drivers / scsi / raid_class.c
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 <James.Bottomley@steeleye.com>
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
22 struct 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
32 struct 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
59 static 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
77 static 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(sizeof(*rd), GFP_KERNEL);
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
94 static 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
111 static DECLARE_TRANSPORT_CLASS(raid_class,
112                                "raid_devices",
113                                raid_setup,
114                                raid_remove,
115                                NULL);
116
117 static 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
128 static 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
142 static 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
160 static 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)                   \
175 static 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)                         \
185 raid_attr_show_internal(attr, %s, name,                                 \
186         const char *name;                                               \
187         code                                                            \
188         name = raid_##states##_name(rd->attr);                          \
189 )                                                                       \
190 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
191
192
193 #define raid_attr_ro_internal(attr, code)                               \
194 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
195 static 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
208 raid_attr_ro_state(level);
209 raid_attr_ro_fn(resync);
210 raid_attr_ro_state_fn(state);
211
212 static void raid_component_release(struct device *dev)
213 {
214         struct raid_component *rc =
215                 container_of(dev, struct raid_component, dev);
216         dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n");
217         put_device(rc->dev.parent);
218         kfree(rc);
219 }
220
221 int raid_component_add(struct raid_template *r,struct device *raid_dev,
222                        struct device *component_dev)
223 {
224         struct device *cdev =
225                 attribute_container_find_class_device(&r->raid_attrs.ac,
226                                                       raid_dev);
227         struct raid_component *rc;
228         struct raid_data *rd = dev_get_drvdata(cdev);
229         int err;
230
231         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
232         if (!rc)
233                 return -ENOMEM;
234
235         INIT_LIST_HEAD(&rc->node);
236         device_initialize(&rc->dev);
237         rc->dev.release = raid_component_release;
238         rc->dev.parent = get_device(component_dev);
239         rc->num = rd->component_count++;
240
241         dev_set_name(&rc->dev, "component-%d", rc->num);
242         list_add_tail(&rc->node, &rd->component_list);
243         rc->dev.class = &raid_class.class;
244         err = device_add(&rc->dev);
245         if (err)
246                 goto err_out;
247
248         return 0;
249
250 err_out:
251         list_del(&rc->node);
252         rd->component_count--;
253         put_device(component_dev);
254         kfree(rc);
255         return err;
256 }
257 EXPORT_SYMBOL(raid_component_add);
258
259 struct raid_template *
260 raid_class_attach(struct raid_function_template *ft)
261 {
262         struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
263                                           GFP_KERNEL);
264         int count = 0;
265
266         if (unlikely(!i))
267                 return NULL;
268
269         i->f = ft;
270
271         i->r.raid_attrs.ac.class = &raid_class.class;
272         i->r.raid_attrs.ac.match = raid_match;
273         i->r.raid_attrs.ac.attrs = &i->attrs[0];
274
275         attribute_container_register(&i->r.raid_attrs.ac);
276
277         i->attrs[count++] = &dev_attr_level;
278         i->attrs[count++] = &dev_attr_resync;
279         i->attrs[count++] = &dev_attr_state;
280
281         i->attrs[count] = NULL;
282         BUG_ON(count > RAID_NUM_ATTRS);
283
284         return &i->r;
285 }
286 EXPORT_SYMBOL(raid_class_attach);
287
288 void
289 raid_class_release(struct raid_template *r)
290 {
291         struct raid_internal *i = to_raid_internal(r);
292
293         BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac));
294
295         kfree(i);
296 }
297 EXPORT_SYMBOL(raid_class_release);
298
299 static __init int raid_init(void)
300 {
301         return transport_class_register(&raid_class);
302 }
303
304 static __exit void raid_exit(void)
305 {
306         transport_class_unregister(&raid_class);
307 }
308
309 MODULE_AUTHOR("James Bottomley");
310 MODULE_DESCRIPTION("RAID device class");
311 MODULE_LICENSE("GPL");
312
313 module_init(raid_init);
314 module_exit(raid_exit);
315