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); 317 318