drivers/scsi/raid_class.c

   1 /*
   2  * RAID Attributes
   3  */
   4 #include <linux/init.h>
   5 #include <linux/module.h>
   6 #include <linux/list.h>
   7 #include <linux/slab.h>
   8 #include <linux/string.h>
   9 #include <linux/raid_class.h>
  10 #include <scsi/scsi_device.h>
  11 #include <scsi/scsi_host.h>
  12
  13 #define RAID_NUM_ATTRS  3
  14
  15 struct raid_internal {
  16         struct raid_template r;
  17         struct raid_function_template *f;
  18         /* The actual attributes */
  19         struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
  20         /* The array of null terminated pointers to attributes
  21          * needed by scsi_sysfs.c */
  22         struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
  23 };
  24
  25 struct raid_component {
  26         struct list_head node;
  27         struct device *dev;
  28         int num;
  29 };
  30
  31 #define to_raid_internal(tmpl)  container_of(tmpl, struct raid_internal, r)
  32
  33 #define tc_to_raid_internal(tcont) ({                                   \
  34         struct raid_template *r =                                       \
  35                 container_of(tcont, struct raid_template, raid_attrs);  \
  36         to_raid_internal(r);                                            \
  37 })
  38
  39 #define ac_to_raid_internal(acont) ({                                   \
  40         struct transport_container *tc =                                \
  41                 container_of(acont, struct transport_container, ac);    \
  42         tc_to_raid_internal(tc);                                        \
  43 })
  44
  45 #define class_device_to_raid_internal(cdev) ({                          \
  46         struct attribute_container *ac =                                \
  47                 attribute_container_classdev_to_container(cdev);        \
  48         ac_to_raid_internal(ac);                                        \
  49 })
  50
  51
  52 static int raid_match(struct attribute_container *cont, struct device *dev)
  53 {
  54         /* We have to look for every subsystem that could house
  55          * emulated RAID devices, so start with SCSI */
  56         struct raid_internal *i = ac_to_raid_internal(cont);
  57
  58         if (scsi_is_sdev_device(dev)) {
  59                 struct scsi_device *sdev = to_scsi_device(dev);
  60
  61                 if (i->f->cookie != sdev->host->hostt)
  62                         return 0;
  63
  64                 return i->f->is_raid(dev);
  65         }
  66         /* FIXME: look at other subsystems too */
  67         return 0;
  68 }
  69
  70 static int raid_setup(struct transport_container *tc, struct device *dev,
  71                        struct class_device *cdev)
  72 {
  73         struct raid_data *rd;
  74
  75         BUG_ON(class_get_devdata(cdev));
  76
  77         rd = kmalloc(sizeof(*rd), GFP_KERNEL);
  78         if (!rd)
  79                 return -ENOMEM;
  80
  81         memset(rd, 0, sizeof(*rd));
  82         INIT_LIST_HEAD(&rd->component_list);
  83         class_set_devdata(cdev, rd);
  84
  85         return 0;
  86 }
  87
  88 static int raid_remove(struct transport_container *tc, struct device *dev,
  89                        struct class_device *cdev)
  90 {
  91         struct raid_data *rd = class_get_devdata(cdev);
  92         struct raid_component *rc, *next;
  93         class_set_devdata(cdev, NULL);
  94         list_for_each_entry_safe(rc, next, &rd->component_list, node) {
  95                 char buf[40];
  96                 snprintf(buf, sizeof(buf), "component-%d", rc->num);
  97                 list_del(&rc->node);
  98                 sysfs_remove_link(&cdev->kobj, buf);
  99                 kfree(rc);
 100         }
 101         kfree(class_get_devdata(cdev));
 102         return 0;
 103 }
 104
 105 static DECLARE_TRANSPORT_CLASS(raid_class,
 106                                "raid_devices",
 107                                raid_setup,
 108                                raid_remove,
 109                                NULL);
 110
 111 static struct {
 112         enum raid_state value;
 113         char            *name;
 114 } raid_states[] = {
 115         { RAID_ACTIVE, "active" },
 116         { RAID_DEGRADED, "degraded" },
 117         { RAID_RESYNCING, "resyncing" },
 118         { RAID_OFFLINE, "offline" },
 119 };
 120
 121 static const char *raid_state_name(enum raid_state state)
 122 {
 123         int i;
 124         char *name = NULL;
 125
 126         for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
 127                 if (raid_states[i].value == state) {
 128                         name = raid_states[i].name;
 129                         break;
 130                 }
 131         }
 132         return name;
 133 }
 134
 135
 136 #define raid_attr_show_internal(attr, fmt, var, code)                   \
 137 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf)   \
 138 {                                                                       \
 139         struct raid_data *rd = class_get_devdata(cdev);                 \
 140         code                                                            \
 141         return snprintf(buf, 20, #fmt "\n", var);                       \
 142 }
 143
 144 #define raid_attr_ro_states(attr, states, code)                         \
 145 raid_attr_show_internal(attr, %s, name,                                 \
 146         const char *name;                                               \
 147         code                                                            \
 148         name = raid_##states##_name(rd->attr);                          \
 149 )                                                                       \
 150 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
 151
 152
 153 #define raid_attr_ro_internal(attr, code)                               \
 154 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
 155 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
 156
 157 #define ATTR_CODE(attr)                                                 \
 158         struct raid_internal *i = class_device_to_raid_internal(cdev);  \
 159         if (i->f->get_##attr)                                           \
 160                 i->f->get_##attr(cdev->dev);
 161
 162 #define raid_attr_ro(attr)      raid_attr_ro_internal(attr, )
 163 #define raid_attr_ro_fn(attr)   raid_attr_ro_internal(attr, ATTR_CODE(attr))
 164 #define raid_attr_ro_state(attr)        raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
 165
 166 raid_attr_ro(level);
 167 raid_attr_ro_fn(resync);
 168 raid_attr_ro_state(state);
 169
 170 void raid_component_add(struct raid_template *r,struct device *raid_dev,
 171                         struct device *component_dev)
 172 {
 173         struct class_device *cdev =
 174                 attribute_container_find_class_device(&r->raid_attrs.ac,
 175                                                       raid_dev);
 176         struct raid_component *rc;
 177         struct raid_data *rd = class_get_devdata(cdev);
 178         char buf[40];
 179
 180         rc = kmalloc(sizeof(*rc), GFP_KERNEL);
 181         if (!rc)
 182                 return;
 183
 184         INIT_LIST_HEAD(&rc->node);
 185         rc->dev = component_dev;
 186         rc->num = rd->component_count++;
 187
 188         snprintf(buf, sizeof(buf), "component-%d", rc->num);
 189         list_add_tail(&rc->node, &rd->component_list);
 190         sysfs_create_link(&cdev->kobj, &component_dev->kobj, buf);
 191 }
 192 EXPORT_SYMBOL(raid_component_add);
 193
 194 struct raid_template *
 195 raid_class_attach(struct raid_function_template *ft)
 196 {
 197         struct raid_internal *i = kmalloc(sizeof(struct raid_internal),
 198                                           GFP_KERNEL);
 199         int count = 0;
 200
 201         if (unlikely(!i))
 202                 return NULL;
 203
 204         memset(i, 0, sizeof(*i));
 205
 206         i->f = ft;
 207
 208         i->r.raid_attrs.ac.class = &raid_class.class;
 209         i->r.raid_attrs.ac.match = raid_match;
 210         i->r.raid_attrs.ac.attrs = &i->attrs[0];
 211
 212         attribute_container_register(&i->r.raid_attrs.ac);
 213
 214         i->attrs[count++] = &class_device_attr_level;
 215         i->attrs[count++] = &class_device_attr_resync;
 216         i->attrs[count++] = &class_device_attr_state;
 217
 218         i->attrs[count] = NULL;
 219         BUG_ON(count > RAID_NUM_ATTRS);
 220
 221         return &i->r;
 222 }
 223 EXPORT_SYMBOL(raid_class_attach);
 224
 225 void
 226 raid_class_release(struct raid_template *r)
 227 {
 228         struct raid_internal *i = to_raid_internal(r);
 229
 230         attribute_container_unregister(&i->r.raid_attrs.ac);
 231
 232         kfree(i);
 233 }
 234 EXPORT_SYMBOL(raid_class_release);
 235
 236 static __init int raid_init(void)
 237 {
 238         return transport_class_register(&raid_class);
 239 }
 240
 241 static __exit void raid_exit(void)
 242 {
 243         transport_class_unregister(&raid_class);
 244 }
 245
 246 MODULE_AUTHOR("James Bottomley");
 247 MODULE_DESCRIPTION("RAID device class");
 248 MODULE_LICENSE("GPL");
 249
 250 module_init(raid_init);
 251 module_exit(raid_exit);
 252