config: tegra3: enable /dev mount with ACL
[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 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
33 struct 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
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 defined(CONFIG_SCSI) || defined(CONFIG_SCSI_MODULE)
67         if (scsi_is_sdev_device(dev)) {
68                 struct scsi_device *sdev = to_scsi_device(dev);
69
70                 if (i->f->cookie != sdev->host->hostt)
71                         return 0;
72
73                 return i->f->is_raid(dev);
74         }
75 #endif
76         /* FIXME: look at other subsystems too */
77         return 0;
78 }
79
80 static int raid_setup(struct transport_container *tc, struct device *dev,
81                        struct device *cdev)
82 {
83         struct raid_data *rd;
84
85         BUG_ON(dev_get_drvdata(cdev));
86
87         rd = kzalloc(sizeof(*rd), GFP_KERNEL);
88         if (!rd)
89                 return -ENOMEM;
90
91         INIT_LIST_HEAD(&rd->component_list);
92         dev_set_drvdata(cdev, rd);
93                 
94         return 0;
95 }
96
97 static int raid_remove(struct transport_container *tc, struct device *dev,
98                        struct device *cdev)
99 {
100         struct raid_data *rd = dev_get_drvdata(cdev);
101         struct raid_component *rc, *next;
102         dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
103         dev_set_drvdata(cdev, NULL);
104         list_for_each_entry_safe(rc, next, &rd->component_list, node) {
105                 list_del(&rc->node);
106                 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n");
107                 device_unregister(&rc->dev);
108         }
109         dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
110         kfree(rd);
111         return 0;
112 }
113
114 static DECLARE_TRANSPORT_CLASS(raid_class,
115                                "raid_devices",
116                                raid_setup,
117                                raid_remove,
118                                NULL);
119
120 static const struct {
121         enum raid_state value;
122         char            *name;
123 } raid_states[] = {
124         { RAID_STATE_UNKNOWN, "unknown" },
125         { RAID_STATE_ACTIVE, "active" },
126         { RAID_STATE_DEGRADED, "degraded" },
127         { RAID_STATE_RESYNCING, "resyncing" },
128         { RAID_STATE_OFFLINE, "offline" },
129 };
130
131 static const char *raid_state_name(enum raid_state state)
132 {
133         int i;
134         char *name = NULL;
135
136         for (i = 0; i < ARRAY_SIZE(raid_states); i++) {
137                 if (raid_states[i].value == state) {
138                         name = raid_states[i].name;
139                         break;
140                 }
141         }
142         return name;
143 }
144
145 static struct {
146         enum raid_level value;
147         char *name;
148 } raid_levels[] = {
149         { RAID_LEVEL_UNKNOWN, "unknown" },
150         { RAID_LEVEL_LINEAR, "linear" },
151         { RAID_LEVEL_0, "raid0" },
152         { RAID_LEVEL_1, "raid1" },
153         { RAID_LEVEL_10, "raid10" },
154         { RAID_LEVEL_1E, "raid1e" },
155         { RAID_LEVEL_3, "raid3" },
156         { RAID_LEVEL_4, "raid4" },
157         { RAID_LEVEL_5, "raid5" },
158         { RAID_LEVEL_50, "raid50" },
159         { RAID_LEVEL_6, "raid6" },
160 };
161
162 static const char *raid_level_name(enum raid_level level)
163 {
164         int i;
165         char *name = NULL;
166
167         for (i = 0; i < ARRAY_SIZE(raid_levels); i++) {
168                 if (raid_levels[i].value == level) {
169                         name = raid_levels[i].name;
170                         break;
171                 }
172         }
173         return name;
174 }
175
176 #define raid_attr_show_internal(attr, fmt, var, code)                   \
177 static ssize_t raid_show_##attr(struct device *dev,                     \
178                                 struct device_attribute *attr,          \
179                                 char *buf)                              \
180 {                                                                       \
181         struct raid_data *rd = dev_get_drvdata(dev);                    \
182         code                                                            \
183         return snprintf(buf, 20, #fmt "\n", var);                       \
184 }
185
186 #define raid_attr_ro_states(attr, states, code)                         \
187 raid_attr_show_internal(attr, %s, name,                                 \
188         const char *name;                                               \
189         code                                                            \
190         name = raid_##states##_name(rd->attr);                          \
191 )                                                                       \
192 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
193
194
195 #define raid_attr_ro_internal(attr, code)                               \
196 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
197 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
198
199 #define ATTR_CODE(attr)                                                 \
200         struct raid_internal *i = device_to_raid_internal(dev);         \
201         if (i->f->get_##attr)                                           \
202                 i->f->get_##attr(dev->parent);
203
204 #define raid_attr_ro(attr)      raid_attr_ro_internal(attr, )
205 #define raid_attr_ro_fn(attr)   raid_attr_ro_internal(attr, ATTR_CODE(attr))
206 #define raid_attr_ro_state(attr)        raid_attr_ro_states(attr, attr, )
207 #define raid_attr_ro_state_fn(attr)     raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
208
209
210 raid_attr_ro_state(level);
211 raid_attr_ro_fn(resync);
212 raid_attr_ro_state_fn(state);
213
214 static void raid_component_release(struct device *dev)
215 {
216         struct raid_component *rc =
217                 container_of(dev, struct raid_component, dev);
218         dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n");
219         put_device(rc->dev.parent);
220         kfree(rc);
221 }
222
223 int raid_component_add(struct raid_template *r,struct device *raid_dev,
224                        struct device *component_dev)
225 {
226         struct device *cdev =
227                 attribute_container_find_class_device(&r->raid_attrs.ac,
228                                                       raid_dev);
229         struct raid_component *rc;
230         struct raid_data *rd = dev_get_drvdata(cdev);
231         int err;
232
233         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
234         if (!rc)
235                 return -ENOMEM;
236
237         INIT_LIST_HEAD(&rc->node);
238         device_initialize(&rc->dev);
239         rc->dev.release = raid_component_release;
240         rc->dev.parent = get_device(component_dev);
241         rc->num = rd->component_count++;
242
243         dev_set_name(&rc->dev, "component-%d", rc->num);
244         list_add_tail(&rc->node, &rd->component_list);
245         rc->dev.class = &raid_class.class;
246         err = device_add(&rc->dev);
247         if (err)
248                 goto err_out;
249
250         return 0;
251
252 err_out:
253         list_del(&rc->node);
254         rd->component_count--;
255         put_device(component_dev);
256         kfree(rc);
257         return err;
258 }
259 EXPORT_SYMBOL(raid_component_add);
260
261 struct raid_template *
262 raid_class_attach(struct raid_function_template *ft)
263 {
264         struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
265                                           GFP_KERNEL);
266         int count = 0;
267
268         if (unlikely(!i))
269                 return NULL;
270
271         i->f = ft;
272
273         i->r.raid_attrs.ac.class = &raid_class.class;
274         i->r.raid_attrs.ac.match = raid_match;
275         i->r.raid_attrs.ac.attrs = &i->attrs[0];
276
277         attribute_container_register(&i->r.raid_attrs.ac);
278
279         i->attrs[count++] = &dev_attr_level;
280         i->attrs[count++] = &dev_attr_resync;
281         i->attrs[count++] = &dev_attr_state;
282
283         i->attrs[count] = NULL;
284         BUG_ON(count > RAID_NUM_ATTRS);
285
286         return &i->r;
287 }
288 EXPORT_SYMBOL(raid_class_attach);
289
290 void
291 raid_class_release(struct raid_template *r)
292 {
293         struct raid_internal *i = to_raid_internal(r);
294
295         BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac));
296
297         kfree(i);
298 }
299 EXPORT_SYMBOL(raid_class_release);
300
301 static __init int raid_init(void)
302 {
303         return transport_class_register(&raid_class);
304 }
305
306 static __exit void raid_exit(void)
307 {
308         transport_class_unregister(&raid_class);
309 }
310
311 MODULE_AUTHOR("James Bottomley");
312 MODULE_DESCRIPTION("RAID device class");
313 MODULE_LICENSE("GPL");
314
315 module_init(raid_init);
316 module_exit(raid_exit);
317