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