err.no Git - linux-2.6/blob - 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/raid_class.h>
  16 #include <scsi/scsi_device.h>
  17 #include <scsi/scsi_host.h>
  18
  19 #define RAID_NUM_ATTRS  3
  20
  21 struct raid_internal {
  22         struct raid_template r;
  23         struct raid_function_template *f;
  24         /* The actual attributes */
  25         struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
  26         /* The array of null terminated pointers to attributes
  27          * needed by scsi_sysfs.c */
  28         struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
  29 };
  30
  31 struct raid_component {
  32         struct list_head node;
  33         struct class_device cdev;
  34         int num;
  35 };
  36
  37 #define to_raid_internal(tmpl)  container_of(tmpl, struct raid_internal, r)
  38
  39 #define tc_to_raid_internal(tcont) ({                                   \
  40         struct raid_template *r =                                       \
  41                 container_of(tcont, struct raid_template, raid_attrs);  \
  42         to_raid_internal(r);                                            \
  43 })
  44
  45 #define ac_to_raid_internal(acont) ({                                   \
  46         struct transport_container *tc =                                \
  47                 container_of(acont, struct transport_container, ac);    \
  48         tc_to_raid_internal(tc);                                        \
  49 })
  50
  51 #define class_device_to_raid_internal(cdev) ({                          \
  52         struct attribute_container *ac =                                \
  53                 attribute_container_classdev_to_container(cdev);        \
  54         ac_to_raid_internal(ac);                                        \
  55 })
  56
  57
  58 static int raid_match(struct attribute_container *cont, struct device *dev)
  59 {
  60         /* We have to look for every subsystem that could house
  61          * emulated RAID devices, so start with SCSI */
  62         struct raid_internal *i = ac_to_raid_internal(cont);
  63
  64         if (scsi_is_sdev_device(dev)) {
  65                 struct scsi_device *sdev = to_scsi_device(dev);
  66
  67                 if (i->f->cookie != sdev->host->hostt)
  68                         return 0;
  69
  70                 return i->f->is_raid(dev);
  71         }
  72         /* FIXME: look at other subsystems too */
  73         return 0;
  74 }
  75
  76 static int raid_setup(struct transport_container *tc, struct device *dev,
  77                        struct class_device *cdev)
  78 {
  79         struct raid_data *rd;
  80
  81         BUG_ON(class_get_devdata(cdev));
  82
  83         rd = kzalloc(sizeof(*rd), GFP_KERNEL);
  84         if (!rd)
  85                 return -ENOMEM;
  86
  87         INIT_LIST_HEAD(&rd->component_list);
  88         class_set_devdata(cdev, rd);
  89
  90         return 0;
  91 }
  92
  93 static int raid_remove(struct transport_container *tc, struct device *dev,
  94                        struct class_device *cdev)
  95 {
  96         struct raid_data *rd = class_get_devdata(cdev);
  97         struct raid_component *rc, *next;
  98         dev_printk(KERN_ERR, dev, "RAID REMOVE\n");
  99         class_set_devdata(cdev, NULL);
 100         list_for_each_entry_safe(rc, next, &rd->component_list, node) {
 101                 list_del(&rc->node);
 102                 dev_printk(KERN_ERR, rc->cdev.dev, "RAID COMPONENT REMOVE\n");
 103                 class_device_unregister(&rc->cdev);
 104         }
 105         dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n");
 106         kfree(rd);
 107         return 0;
 108 }
 109
 110 static DECLARE_TRANSPORT_CLASS(raid_class,
 111                                "raid_devices",
 112                                raid_setup,
 113                                raid_remove,
 114                                NULL);
 115
 116 static struct {
 117         enum raid_state value;
 118         char            *name;
 119 } raid_states[] = {
 120         { RAID_STATE_UNKNOWN, "unknown" },
 121         { RAID_STATE_ACTIVE, "active" },
 122         { RAID_STATE_DEGRADED, "degraded" },
 123         { RAID_STATE_RESYNCING, "resyncing" },
 124         { RAID_STATE_OFFLINE, "offline" },
 125 };
 126
 127 static const char *raid_state_name(enum raid_state state)
 128 {
 129         int i;
 130         char *name = NULL;
 131
 132         for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
 133                 if (raid_states[i].value == state) {
 134                         name = raid_states[i].name;
 135                         break;
 136                 }
 137         }
 138         return name;
 139 }
 140
 141 static struct {
 142         enum raid_level value;
 143         char *name;
 144 } raid_levels[] = {
 145         { RAID_LEVEL_UNKNOWN, "unknown" },
 146         { RAID_LEVEL_LINEAR, "linear" },
 147         { RAID_LEVEL_0, "raid0" },
 148         { RAID_LEVEL_1, "raid1" },
 149         { RAID_LEVEL_3, "raid3" },
 150         { RAID_LEVEL_4, "raid4" },
 151         { RAID_LEVEL_5, "raid5" },
 152         { RAID_LEVEL_6, "raid6" },
 153 };
 154
 155 static const char *raid_level_name(enum raid_level level)
 156 {
 157         int i;
 158         char *name = NULL;
 159
 160         for (i = 0; i < sizeof(raid_levels)/sizeof(raid_levels[0]); i++) {
 161                 if (raid_levels[i].value == level) {
 162                         name = raid_levels[i].name;
 163                         break;
 164                 }
 165         }
 166         return name;
 167 }
 168
 169 #define raid_attr_show_internal(attr, fmt, var, code)                   \
 170 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf)   \
 171 {                                                                       \
 172         struct raid_data *rd = class_get_devdata(cdev);                 \
 173         code                                                            \
 174         return snprintf(buf, 20, #fmt "\n", var);                       \
 175 }
 176
 177 #define raid_attr_ro_states(attr, states, code)                         \
 178 raid_attr_show_internal(attr, %s, name,                                 \
 179         const char *name;                                               \
 180         code                                                            \
 181         name = raid_##states##_name(rd->attr);                          \
 182 )                                                                       \
 183 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
 184
 185
 186 #define raid_attr_ro_internal(attr, code)                               \
 187 raid_attr_show_internal(attr, %d, rd->attr, code)                       \
 188 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)
 189
 190 #define ATTR_CODE(attr)                                                 \
 191         struct raid_internal *i = class_device_to_raid_internal(cdev);  \
 192         if (i->f->get_##attr)                                           \
 193                 i->f->get_##attr(cdev->dev);
 194
 195 #define raid_attr_ro(attr)      raid_attr_ro_internal(attr, )
 196 #define raid_attr_ro_fn(attr)   raid_attr_ro_internal(attr, ATTR_CODE(attr))
 197 #define raid_attr_ro_state(attr)        raid_attr_ro_states(attr, attr, )
 198 #define raid_attr_ro_state_fn(attr)     raid_attr_ro_states(attr, attr, ATTR_CODE(attr))
 199
 200
 201 raid_attr_ro_state(level);
 202 raid_attr_ro_fn(resync);
 203 raid_attr_ro_state_fn(state);
 204
 205 static void raid_component_release(struct class_device *cdev)
 206 {
 207         struct raid_component *rc = container_of(cdev, struct raid_component,
 208                                                  cdev);
 209         dev_printk(KERN_ERR, rc->cdev.dev, "COMPONENT RELEASE\n");
 210         put_device(rc->cdev.dev);
 211         kfree(rc);
 212 }
 213
 214 void raid_component_add(struct raid_template *r,struct device *raid_dev,
 215                         struct device *component_dev)
 216 {
 217         struct class_device *cdev =
 218                 attribute_container_find_class_device(&r->raid_attrs.ac,
 219                                                       raid_dev);
 220         struct raid_component *rc;
 221         struct raid_data *rd = class_get_devdata(cdev);
 222
 223         rc = kzalloc(sizeof(*rc), GFP_KERNEL);
 224         if (!rc)
 225                 return;
 226
 227         INIT_LIST_HEAD(&rc->node);
 228         class_device_initialize(&rc->cdev);
 229         rc->cdev.release = raid_component_release;
 230         rc->cdev.dev = get_device(component_dev);
 231         rc->num = rd->component_count++;
 232
 233         snprintf(rc->cdev.class_id, sizeof(rc->cdev.class_id),
 234                  "component-%d", rc->num);
 235         list_add_tail(&rc->node, &rd->component_list);
 236         rc->cdev.parent = cdev;
 237         rc->cdev.class = &raid_class.class;
 238         class_device_add(&rc->cdev);
 239 }
 240 EXPORT_SYMBOL(raid_component_add);
 241
 242 struct raid_template *
 243 raid_class_attach(struct raid_function_template *ft)
 244 {
 245         struct raid_internal *i = kzalloc(sizeof(struct raid_internal),
 246                                           GFP_KERNEL);
 247         int count = 0;
 248
 249         if (unlikely(!i))
 250                 return NULL;
 251
 252         i->f = ft;
 253
 254         i->r.raid_attrs.ac.class = &raid_class.class;
 255         i->r.raid_attrs.ac.match = raid_match;
 256         i->r.raid_attrs.ac.attrs = &i->attrs[0];
 257
 258         attribute_container_register(&i->r.raid_attrs.ac);
 259
 260         i->attrs[count++] = &class_device_attr_level;
 261         i->attrs[count++] = &class_device_attr_resync;
 262         i->attrs[count++] = &class_device_attr_state;
 263
 264         i->attrs[count] = NULL;
 265         BUG_ON(count > RAID_NUM_ATTRS);
 266
 267         return &i->r;
 268 }
 269 EXPORT_SYMBOL(raid_class_attach);
 270
 271 void
 272 raid_class_release(struct raid_template *r)
 273 {
 274         struct raid_internal *i = to_raid_internal(r);
 275
 276         attribute_container_unregister(&i->r.raid_attrs.ac);
 277
 278         kfree(i);
 279 }
 280 EXPORT_SYMBOL(raid_class_release);
 281
 282 static __init int raid_init(void)
 283 {
 284         return transport_class_register(&raid_class);
 285 }
 286
 287 static __exit void raid_exit(void)
 288 {
 289         transport_class_unregister(&raid_class);
 290 }
 291
 292 MODULE_AUTHOR("James Bottomley");
 293 MODULE_DESCRIPTION("RAID device class");
 294 MODULE_LICENSE("GPL");
 295
 296 module_init(raid_init);
 297 module_exit(raid_exit);
 298