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); 298 299