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 { RAID_LEVEL_JBOD, "jbod" }, 161 }; 162 163 static const char *raid_level_name(enum raid_level level) 164 { 165 int i; 166 char *name = NULL; 167 168 for (i = 0; i < ARRAY_SIZE(raid_levels); i++) { 169 if (raid_levels[i].value == level) { 170 name = raid_levels[i].name; 171 break; 172 } 173 } 174 return name; 175 } 176 177 #define raid_attr_show_internal(attr, fmt, var, code) \ 178 static ssize_t raid_show_##attr(struct device *dev, \ 179 struct device_attribute *attr, \ 180 char *buf) \ 181 { \ 182 struct raid_data *rd = dev_get_drvdata(dev); \ 183 code \ 184 return snprintf(buf, 20, #fmt "\n", var); \ 185 } 186 187 #define raid_attr_ro_states(attr, states, code) \ 188 raid_attr_show_internal(attr, %s, name, \ 189 const char *name; \ 190 code \ 191 name = raid_##states##_name(rd->attr); \ 192 ) \ 193 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 194 195 196 #define raid_attr_ro_internal(attr, code) \ 197 raid_attr_show_internal(attr, %d, rd->attr, code) \ 198 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 199 200 #define ATTR_CODE(attr) \ 201 struct raid_internal *i = device_to_raid_internal(dev); \ 202 if (i->f->get_##attr) \ 203 i->f->get_##attr(dev->parent); 204 205 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 206 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 207 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ) 208 #define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 209 210 211 raid_attr_ro_state(level); 212 raid_attr_ro_fn(resync); 213 raid_attr_ro_state_fn(state); 214 215 static void raid_component_release(struct device *dev) 216 { 217 struct raid_component *rc = 218 container_of(dev, struct raid_component, dev); 219 dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n"); 220 put_device(rc->dev.parent); 221 kfree(rc); 222 } 223 224 int raid_component_add(struct raid_template *r,struct device *raid_dev, 225 struct device *component_dev) 226 { 227 struct device *cdev = 228 attribute_container_find_class_device(&r->raid_attrs.ac, 229 raid_dev); 230 struct raid_component *rc; 231 struct raid_data *rd = dev_get_drvdata(cdev); 232 int err; 233 234 rc = kzalloc(sizeof(*rc), GFP_KERNEL); 235 if (!rc) 236 return -ENOMEM; 237 238 INIT_LIST_HEAD(&rc->node); 239 device_initialize(&rc->dev); 240 rc->dev.release = raid_component_release; 241 rc->dev.parent = get_device(component_dev); 242 rc->num = rd->component_count++; 243 244 dev_set_name(&rc->dev, "component-%d", rc->num); 245 list_add_tail(&rc->node, &rd->component_list); 246 rc->dev.class = &raid_class.class; 247 err = device_add(&rc->dev); 248 if (err) 249 goto err_out; 250 251 return 0; 252 253 err_out: 254 list_del(&rc->node); 255 rd->component_count--; 256 put_device(component_dev); 257 kfree(rc); 258 return err; 259 } 260 EXPORT_SYMBOL(raid_component_add); 261 262 struct raid_template * 263 raid_class_attach(struct raid_function_template *ft) 264 { 265 struct raid_internal *i = kzalloc(sizeof(struct raid_internal), 266 GFP_KERNEL); 267 int count = 0; 268 269 if (unlikely(!i)) 270 return NULL; 271 272 i->f = ft; 273 274 i->r.raid_attrs.ac.class = &raid_class.class; 275 i->r.raid_attrs.ac.match = raid_match; 276 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 277 278 attribute_container_register(&i->r.raid_attrs.ac); 279 280 i->attrs[count++] = &dev_attr_level; 281 i->attrs[count++] = &dev_attr_resync; 282 i->attrs[count++] = &dev_attr_state; 283 284 i->attrs[count] = NULL; 285 BUG_ON(count > RAID_NUM_ATTRS); 286 287 return &i->r; 288 } 289 EXPORT_SYMBOL(raid_class_attach); 290 291 void 292 raid_class_release(struct raid_template *r) 293 { 294 struct raid_internal *i = to_raid_internal(r); 295 296 BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac)); 297 298 kfree(i); 299 } 300 EXPORT_SYMBOL(raid_class_release); 301 302 static __init int raid_init(void) 303 { 304 return transport_class_register(&raid_class); 305 } 306 307 static __exit void raid_exit(void) 308 { 309 transport_class_unregister(&raid_class); 310 } 311 312 MODULE_AUTHOR("James Bottomley"); 313 MODULE_DESCRIPTION("RAID device class"); 314 MODULE_LICENSE("GPL"); 315 316 module_init(raid_init); 317 module_exit(raid_exit); 318 319