Merge branch 'master'
[linux-2.6.git] / drivers / scsi / raid_class.c
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
23 struct raid_internal {
24         struct raid_template r;
25         struct raid_function_template *f;
26         /* The actual attributes */
27         struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
28         /* The array of null terminated pointers to attributes 
29          * needed by scsi_sysfs.c */
30         struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
31 };
32
33 struct raid_component {
34         struct list_head node;
35         struct class_device cdev;
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 class_device_to_raid_internal(cdev) ({                          \
54         struct attribute_container *ac =                                \
55                 attribute_container_classdev_to_container(cdev);        \
56         ac_to_raid_internal(ac);                                        \
57 })
58         
59
60 static 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 (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
78 static int raid_setup(struct transport_container *tc, struct device *dev,
79                        struct class_device *cdev)
80 {
81         struct raid_data *rd;
82
83         BUG_ON(class_get_devdata(cdev));
84
85         rd = kzalloc(sizeof(*rd), GFP_KERNEL);
86         if (!rd)
87                 return -ENOMEM;
88
89         INIT_LIST_HEAD(&rd->component_list);
90         class_set_devdata(cdev, rd);
91                 
92         return 0;
93 }
94
95 static int raid_remove(struct transport_container *tc, struct device *dev,
96                        struct class_device *cdev)
97 {
98         struct raid_data *rd = class_get_devdata(cdev);
99         struct raid_component *rc, *next;
100         dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
101         class_set_devdata(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->cdev.dev, "RAID COMPONENT REMOVE\n");
105                 class_device_unregister(&rc->cdev);
106         }
107         dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
108         kfree(rd);
109         return 0;
110 }
111
112 static DECLARE_TRANSPORT_CLASS(raid_class,
113                                "raid_devices",
114                                raid_setup,
115                                raid_remove,
116                                NULL);
117
118 static 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
129 static const char *raid_state_name(enum raid_state state)
130 {
131         int i;
132         char *name = NULL;
133
134         for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
135                 if (raid_states[i].value == state) {
136                         name = raid_states[i].name;
137                         break;
138                 }
139         }
140         return name;
141 }
142
143 static 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_3, "raid3" },
153         { RAID_LEVEL_4, "raid4" },
154         { RAID_LEVEL_5, "raid5" },
155         { RAID_LEVEL_50, "raid50" },
156         { RAID_LEVEL_6, "raid6" },
157 };
158
159 static const char *raid_level_name(enum raid_level level)
160 {
161         int i;
162         char *name = NULL;
163
164         for (i = 0; i < sizeof(raid_levels)/sizeof(raid_levels[0]); i++) {
165                 if (raid_levels[i].value == level) {
166                         name = raid_levels[i].name;
167                         break;
168                 }
169         }
170         return name;
171 }
172
173 #define raid_attr_show_internal(attr, fmt, var, code)                   \
174 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf)   \
175 {                                                                       \
176         struct raid_data *rd = class_get_devdata(cdev);                 \
177         code                                                            \
178         return snprintf(buf, 20, #fmt "\n", var);                       \
179 }
180
181 #define raid_attr_ro_states(attr, states, code)                         \
182 raid_attr_show_internal(attr, %s, name,                                 \
183         const char *name;                                               \
184         code                                                            \
185         name = raid_##states##_name(rd->attr);                          \
186 )                                                                       \
187 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
188
189
190 #define raid_attr_ro_internal(attr, code)                               \
191 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
192 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
193
194 #define ATTR_CODE(attr)                                                 \
195         struct raid_internal *i = class_device_to_raid_internal(cdev);  \
196         if (i->f->get_##attr)                                           \
197                 i->f->get_##attr(cdev->dev);
198
199 #define raid_attr_ro(attr)      raid_attr_ro_internal(attr, )
200 #define raid_attr_ro_fn(attr)   raid_attr_ro_internal(attr, ATTR_CODE(attr))
201 #define raid_attr_ro_state(attr)        raid_attr_ro_states(attr, attr, )
202 #define raid_attr_ro_state_fn(attr)     raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
203
204
205 raid_attr_ro_state(level);
206 raid_attr_ro_fn(resync);
207 raid_attr_ro_state_fn(state);
208
209 static void raid_component_release(struct class_device *cdev)
210 {
211         struct raid_component *rc = container_of(cdev, struct raid_component,
212                                                  cdev);
213         dev_printk(KERN_ERR, rc->cdev.dev, "COMPONENT RELEASE\n");
214         put_device(rc->cdev.dev);
215         kfree(rc);
216 }
217
218 void raid_component_add(struct raid_template *r,struct device *raid_dev,
219                         struct device *component_dev)
220 {
221         struct class_device *cdev =
222                 attribute_container_find_class_device(&r->raid_attrs.ac,
223                                                       raid_dev);
224         struct raid_component *rc;
225         struct raid_data *rd = class_get_devdata(cdev);
226
227         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
228         if (!rc)
229                 return;
230
231         INIT_LIST_HEAD(&rc->node);
232         class_device_initialize(&rc->cdev);
233         rc->cdev.release = raid_component_release;
234         rc->cdev.dev = get_device(component_dev);
235         rc->num = rd->component_count++;
236
237         snprintf(rc->cdev.class_id, sizeof(rc->cdev.class_id),
238                  "component-%d", rc->num);
239         list_add_tail(&rc->node, &rd->component_list);
240         rc->cdev.parent = cdev;
241         rc->cdev.class = &raid_class.class;
242         class_device_add(&rc->cdev);
243 }
244 EXPORT_SYMBOL(raid_component_add);
245
246 struct raid_template *
247 raid_class_attach(struct raid_function_template *ft)
248 {
249         struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
250                                           GFP_KERNEL);
251         int count = 0;
252
253         if (unlikely(!i))
254                 return NULL;
255
256         i->f = ft;
257
258         i->r.raid_attrs.ac.class = &raid_class.class;
259         i->r.raid_attrs.ac.match = raid_match;
260         i->r.raid_attrs.ac.attrs = &i->attrs[0];
261
262         attribute_container_register(&i->r.raid_attrs.ac);
263
264         i->attrs[count++] = &class_device_attr_level;
265         i->attrs[count++] = &class_device_attr_resync;
266         i->attrs[count++] = &class_device_attr_state;
267
268         i->attrs[count] = NULL;
269         BUG_ON(count > RAID_NUM_ATTRS);
270
271         return &i->r;
272 }
273 EXPORT_SYMBOL(raid_class_attach);
274
275 void
276 raid_class_release(struct raid_template *r)
277 {
278         struct raid_internal *i = to_raid_internal(r);
279
280         attribute_container_unregister(&i->r.raid_attrs.ac);
281
282         kfree(i);
283 }
284 EXPORT_SYMBOL(raid_class_release);
285
286 static __init int raid_init(void)
287 {
288         return transport_class_register(&raid_class);
289 }
290
291 static __exit void raid_exit(void)
292 {
293         transport_class_unregister(&raid_class);
294 }
295
296 MODULE_AUTHOR("James Bottomley");
297 MODULE_DESCRIPTION("RAID device class");
298 MODULE_LICENSE("GPL");
299
300 module_init(raid_init);
301 module_exit(raid_exit);
302