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 (IS_ENABLED(CONFIG_SCSI) && scsi_is_sdev_device(dev)) { 67 struct scsi_device *sdev = to_scsi_device(dev); 68 69 if (i->f->cookie != sdev->host->hostt) 70 return 0; 71 72 return i->f->is_raid(dev); 73 } 74 /* FIXME: look at other subsystems too */ 75 return 0; 76 } 77 78 static int raid_setup(struct transport_container *tc, struct device *dev, 79 struct device *cdev) 80 { 81 struct raid_data *rd; 82 83 BUG_ON(dev_get_drvdata(cdev)); 84 85 rd = kzalloc(sizeof(*rd), GFP_KERNEL); 86 if (!rd) 87 return -ENOMEM; 88 89 INIT_LIST_HEAD(&rd->component_list); 90 dev_set_drvdata(cdev, rd); 91 92 return 0; 93 } 94 95 static int raid_remove(struct transport_container *tc, struct device *dev, 96 struct device *cdev) 97 { 98 struct raid_data *rd = dev_get_drvdata(cdev); 99 struct raid_component *rc, *next; 100 dev_printk(KERN_ERR, dev, "RAID REMOVE\n"); 101 dev_set_drvdata(cdev, NULL); 102 list_for_each_entry_safe(rc, next, &rd->component_list, node) { 103 list_del(&rc->node); 104 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n"); 105 device_unregister(&rc->dev); 106 } 107 dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n"); 108 kfree(rd); 109 return 0; 110 } 111 112 static DECLARE_TRANSPORT_CLASS(raid_class, 113 "raid_devices", 114 raid_setup, 115 raid_remove, 116 NULL); 117 118 static const struct { 119 enum raid_state value; 120 char *name; 121 } raid_states[] = { 122 { RAID_STATE_UNKNOWN, "unknown" }, 123 { RAID_STATE_ACTIVE, "active" }, 124 { RAID_STATE_DEGRADED, "degraded" }, 125 { RAID_STATE_RESYNCING, "resyncing" }, 126 { RAID_STATE_OFFLINE, "offline" }, 127 }; 128 129 static const char *raid_state_name(enum raid_state state) 130 { 131 int i; 132 char *name = NULL; 133 134 for (i = 0; i < ARRAY_SIZE(raid_states); i++) { 135 if (raid_states[i].value == state) { 136 name = raid_states[i].name; 137 break; 138 } 139 } 140 return name; 141 } 142 143 static struct { 144 enum raid_level value; 145 char *name; 146 } raid_levels[] = { 147 { RAID_LEVEL_UNKNOWN, "unknown" }, 148 { RAID_LEVEL_LINEAR, "linear" }, 149 { RAID_LEVEL_0, "raid0" }, 150 { RAID_LEVEL_1, "raid1" }, 151 { RAID_LEVEL_10, "raid10" }, 152 { RAID_LEVEL_1E, "raid1e" }, 153 { RAID_LEVEL_3, "raid3" }, 154 { RAID_LEVEL_4, "raid4" }, 155 { RAID_LEVEL_5, "raid5" }, 156 { RAID_LEVEL_50, "raid50" }, 157 { RAID_LEVEL_6, "raid6" }, 158 { RAID_LEVEL_JBOD, "jbod" }, 159 }; 160 161 static const char *raid_level_name(enum raid_level level) 162 { 163 int i; 164 char *name = NULL; 165 166 for (i = 0; i < ARRAY_SIZE(raid_levels); i++) { 167 if (raid_levels[i].value == level) { 168 name = raid_levels[i].name; 169 break; 170 } 171 } 172 return name; 173 } 174 175 #define raid_attr_show_internal(attr, fmt, var, code) \ 176 static ssize_t raid_show_##attr(struct device *dev, \ 177 struct device_attribute *attr, \ 178 char *buf) \ 179 { \ 180 struct raid_data *rd = dev_get_drvdata(dev); \ 181 code \ 182 return snprintf(buf, 20, #fmt "\n", var); \ 183 } 184 185 #define raid_attr_ro_states(attr, states, code) \ 186 raid_attr_show_internal(attr, %s, name, \ 187 const char *name; \ 188 code \ 189 name = raid_##states##_name(rd->attr); \ 190 ) \ 191 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 192 193 194 #define raid_attr_ro_internal(attr, code) \ 195 raid_attr_show_internal(attr, %d, rd->attr, code) \ 196 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 197 198 #define ATTR_CODE(attr) \ 199 struct raid_internal *i = device_to_raid_internal(dev); \ 200 if (i->f->get_##attr) \ 201 i->f->get_##attr(dev->parent); 202 203 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 204 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 205 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ) 206 #define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 207 208 209 raid_attr_ro_state(level); 210 raid_attr_ro_fn(resync); 211 raid_attr_ro_state_fn(state); 212 213 static void raid_component_release(struct device *dev) 214 { 215 struct raid_component *rc = 216 container_of(dev, struct raid_component, dev); 217 dev_printk(KERN_ERR, rc->dev.parent, "COMPONENT RELEASE\n"); 218 put_device(rc->dev.parent); 219 kfree(rc); 220 } 221 222 int raid_component_add(struct raid_template *r,struct device *raid_dev, 223 struct device *component_dev) 224 { 225 struct device *cdev = 226 attribute_container_find_class_device(&r->raid_attrs.ac, 227 raid_dev); 228 struct raid_component *rc; 229 struct raid_data *rd = dev_get_drvdata(cdev); 230 int err; 231 232 rc = kzalloc(sizeof(*rc), GFP_KERNEL); 233 if (!rc) 234 return -ENOMEM; 235 236 INIT_LIST_HEAD(&rc->node); 237 device_initialize(&rc->dev); 238 rc->dev.release = raid_component_release; 239 rc->dev.parent = get_device(component_dev); 240 rc->num = rd->component_count++; 241 242 dev_set_name(&rc->dev, "component-%d", rc->num); 243 list_add_tail(&rc->node, &rd->component_list); 244 rc->dev.class = &raid_class.class; 245 err = device_add(&rc->dev); 246 if (err) 247 goto err_out; 248 249 return 0; 250 251 err_out: 252 list_del(&rc->node); 253 rd->component_count--; 254 put_device(component_dev); 255 kfree(rc); 256 return err; 257 } 258 EXPORT_SYMBOL(raid_component_add); 259 260 struct raid_template * 261 raid_class_attach(struct raid_function_template *ft) 262 { 263 struct raid_internal *i = kzalloc(sizeof(struct raid_internal), 264 GFP_KERNEL); 265 int count = 0; 266 267 if (unlikely(!i)) 268 return NULL; 269 270 i->f = ft; 271 272 i->r.raid_attrs.ac.class = &raid_class.class; 273 i->r.raid_attrs.ac.match = raid_match; 274 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 275 276 attribute_container_register(&i->r.raid_attrs.ac); 277 278 i->attrs[count++] = &dev_attr_level; 279 i->attrs[count++] = &dev_attr_resync; 280 i->attrs[count++] = &dev_attr_state; 281 282 i->attrs[count] = NULL; 283 BUG_ON(count > RAID_NUM_ATTRS); 284 285 return &i->r; 286 } 287 EXPORT_SYMBOL(raid_class_attach); 288 289 void 290 raid_class_release(struct raid_template *r) 291 { 292 struct raid_internal *i = to_raid_internal(r); 293 294 BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac)); 295 296 kfree(i); 297 } 298 EXPORT_SYMBOL(raid_class_release); 299 300 static __init int raid_init(void) 301 { 302 return transport_class_register(&raid_class); 303 } 304 305 static __exit void raid_exit(void) 306 { 307 transport_class_unregister(&raid_class); 308 } 309 310 MODULE_AUTHOR("James Bottomley"); 311 MODULE_DESCRIPTION("RAID device class"); 312 MODULE_LICENSE("GPL"); 313 314 module_init(raid_init); 315 module_exit(raid_exit); 316 317