1/*
2 * raid_class.c - implementation of a simple raid visualisation class
3 *
4 * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>
5 *
6 * This file is licensed under GPLv2
7 *
8 * This class is designed to allow raid attributes to be visualised and
9 * manipulated in a form independent of the underlying raid. Ultimately this
10 * should work for both hardware and software raids.
11 */
12#include <linux/init.h>
13#include <linux/module.h>
14#include <linux/list.h>
15#include <linux/slab.h>
16#include <linux/string.h>
17#include <linux/raid_class.h>
18#include <scsi/scsi_device.h>
19#include <scsi/scsi_host.h>
20
21#define RAID_NUM_ATTRS 3
22
23struct raid_internal {
24 struct raid_template r;
25 struct raid_function_template *f;
26 /* The actual attributes */
27 struct device_attribute private_attrs[RAID_NUM_ATTRS];
28 /* The array of null terminated pointers to attributes
29 * needed by scsi_sysfs.c */
30 struct device_attribute *attrs[RAID_NUM_ATTRS + 1];
31};
32
33struct raid_component {
34 struct list_head node;
35 struct device dev;
36 int num;
37};
38
39#define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r)
40
41#define tc_to_raid_internal(tcont) ({ \
42 struct raid_template *r = \
43 container_of(tcont, struct raid_template, raid_attrs); \
44 to_raid_internal(r); \
45})
46
47#define ac_to_raid_internal(acont) ({ \
48 struct transport_container *tc = \
49 container_of(acont, struct transport_container, ac); \
50 tc_to_raid_internal(tc); \
51})
52
53#define device_to_raid_internal(dev) ({ \
54 struct attribute_container *ac = \
55 attribute_container_classdev_to_container(dev); \
56 ac_to_raid_internal(ac); \
57})
58
59
60static int raid_match(struct attribute_container *cont, struct device *dev)
61{
62 /* We have to look for every subsystem that could house
63 * emulated RAID devices, so start with SCSI */
64 struct raid_internal *i = ac_to_raid_internal(cont);
65
66 if (IS_ENABLED(CONFIG_SCSI) && scsi_is_sdev_device(dev)) {
67 struct scsi_device *sdev = to_scsi_device(dev);
68
69 if (i->f->cookie != sdev->host->hostt)
70 return 0;
71
72 return i->f->is_raid(dev);
73 }
74 /* FIXME: look at other subsystems too */
75 return 0;
76}
77
78static int raid_setup(struct transport_container *tc, struct device *dev,
79 struct device *cdev)
80{
81 struct raid_data *rd;
82
83 BUG_ON(dev_get_drvdata(cdev));
84
85 rd = kzalloc(sizeof(*rd), GFP_KERNEL);
86 if (!rd)
87 return -ENOMEM;
88
89 INIT_LIST_HEAD(&rd->component_list);
90 dev_set_drvdata(cdev, rd);
91
92 return 0;
93}
94
95static int raid_remove(struct transport_container *tc, struct device *dev,
96 struct device *cdev)
97{
98 struct raid_data *rd = dev_get_drvdata(cdev);
99 struct raid_component *rc, *next;
100 dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
101 dev_set_drvdata(cdev, NULL);
102 list_for_each_entry_safe(rc, next, &rd->component_list, node) {
103 list_del(&rc->node);
104 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n");
105 device_unregister(&rc->dev);
106 }
107 dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
108 kfree(rd);
109 return 0;
110}
111
112static DECLARE_TRANSPORT_CLASS(raid_class,
113 "raid_devices",
114 raid_setup,
115 raid_remove,
116 NULL);
117
118static const struct {
119 enum raid_state value;
120 char *name;
121} raid_states[] = {
122 { RAID_STATE_UNKNOWN, "unknown" },
123 { RAID_STATE_ACTIVE, "active" },
124 { RAID_STATE_DEGRADED, "degraded" },
125 { RAID_STATE_RESYNCING, "resyncing" },
126 { RAID_STATE_OFFLINE, "offline" },
127};
128
129static const char *raid_state_name(enum raid_state state)
130{
131 int i;
132 char *name = NULL;
133
134 for (i = 0; i < ARRAY_SIZE(raid_states); i++) {
135 if (raid_states[i].value == state) {
136 name = raid_states[i].name;
137 break;
138 }
139 }
140 return name;
141}
142
143static struct {
144 enum raid_level value;
145 char *name;
146} raid_levels[] = {
147 { RAID_LEVEL_UNKNOWN, "unknown" },
148 { RAID_LEVEL_LINEAR, "linear" },
149 { RAID_LEVEL_0, "raid0" },
150 { RAID_LEVEL_1, "raid1" },
151 { RAID_LEVEL_10, "raid10" },
152 { RAID_LEVEL_1E, "raid1e" },
153 { RAID_LEVEL_3, "raid3" },
154 { RAID_LEVEL_4, "raid4" },
155 { RAID_LEVEL_5, "raid5" },
156 { RAID_LEVEL_50, "raid50" },
157 { RAID_LEVEL_6, "raid6" },
158 { RAID_LEVEL_JBOD, "jbod" },
159};
160
161static const char *raid_level_name(enum raid_level level)
162{
163 int i;
164 char *name = NULL;
165
166 for (i = 0; i < ARRAY_SIZE(raid_levels); i++) {
167 if (raid_levels[i].value == level) {
168 name = raid_levels[i].name;
169 break;
170 }
171 }
172 return name;
173}
174
175#define raid_attr_show_internal(attr, fmt, var, code) \
176static ssize_t raid_show_##attr(struct device *dev, \
177 struct device_attribute *attr, \
178 char *buf) \
179{ \
180 struct raid_data *rd = dev_get_drvdata(dev); \
181 code \
182 return snprintf(buf, 20, #fmt "\n", var); \
183}
184
185#define raid_attr_ro_states(attr, states, code) \
186raid_attr_show_internal(attr, %s, name, \
187 const char *name; \
188 code \
189 name = raid_##states##_name(rd->attr); \
190) \
191static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
192
193
194#define raid_attr_ro_internal(attr, code) \
195raid_attr_show_internal(attr, %d, rd->attr, code) \
196static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
197
198#define ATTR_CODE(attr) \
199 struct raid_internal *i = device_to_raid_internal(dev); \
200 if (i->f->get_##attr) \
201 i->f->get_##attr(dev->parent);
202
203#define raid_attr_ro(attr) raid_attr_ro_internal(attr, )
204#define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr))
205#define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, )
206#define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
207
208
209raid_attr_ro_state(level);
210raid_attr_ro_fn(resync);
211raid_attr_ro_state_fn(state);
212
213static void raid_component_release(struct device *dev)
214{
215 struct raid_component *rc =
216 container_of(dev, struct raid_component, dev);
217 dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n");
218 put_device(rc->dev.parent);
219 kfree(rc);
220}
221
222int raid_component_add(struct raid_template *r,struct device *raid_dev,
223 struct device *component_dev)
224{
225 struct device *cdev =
226 attribute_container_find_class_device(&r->raid_attrs.ac,
227 raid_dev);
228 struct raid_component *rc;
229 struct raid_data *rd = dev_get_drvdata(cdev);
230 int err;
231
232 rc = kzalloc(sizeof(*rc), GFP_KERNEL);
233 if (!rc)
234 return -ENOMEM;
235
236 INIT_LIST_HEAD(&rc->node);
237 device_initialize(&rc->dev);
238 rc->dev.release = raid_component_release;
239 rc->dev.parent = get_device(component_dev);
240 rc->num = rd->component_count++;
241
242 dev_set_name(&rc->dev, "component-%d", rc->num);
243 list_add_tail(&rc->node, &rd->component_list);
244 rc->dev.class = &raid_class.class;
245 err = device_add(&rc->dev);
246 if (err)
247 goto err_out;
248
249 return 0;
250
251err_out:
252 list_del(&rc->node);
253 rd->component_count--;
254 put_device(component_dev);
255 kfree(rc);
256 return err;
257}
258EXPORT_SYMBOL(raid_component_add);
259
260struct raid_template *
261raid_class_attach(struct raid_function_template *ft)
262{
263 struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
264 GFP_KERNEL);
265 int count = 0;
266
267 if (unlikely(!i))
268 return NULL;
269
270 i->f = ft;
271
272 i->r.raid_attrs.ac.class = &raid_class.class;
273 i->r.raid_attrs.ac.match = raid_match;
274 i->r.raid_attrs.ac.attrs = &i->attrs[0];
275
276 attribute_container_register(&i->r.raid_attrs.ac);
277
278 i->attrs[count++] = &dev_attr_level;
279 i->attrs[count++] = &dev_attr_resync;
280 i->attrs[count++] = &dev_attr_state;
281
282 i->attrs[count] = NULL;
283 BUG_ON(count > RAID_NUM_ATTRS);
284
285 return &i->r;
286}
287EXPORT_SYMBOL(raid_class_attach);
288
289void
290raid_class_release(struct raid_template *r)
291{
292 struct raid_internal *i = to_raid_internal(r);
293
294 BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac));
295
296 kfree(i);
297}
298EXPORT_SYMBOL(raid_class_release);
299
300static __init int raid_init(void)
301{
302 return transport_class_register(&raid_class);
303}
304
305static __exit void raid_exit(void)
306{
307 transport_class_unregister(&raid_class);
308}
309
310MODULE_AUTHOR("James Bottomley");
311MODULE_DESCRIPTION("RAID device class");
312MODULE_LICENSE("GPL");
313
314module_init(raid_init);
315module_exit(raid_exit);
316
317