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 class_device_attribute private_attrs[RAID_NUM_ATTRS]; 28 /* The array of null terminated pointers to attributes 29 * needed by scsi_sysfs.c */ 30 struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1]; 31 }; 32 33 struct raid_component { 34 struct list_head node; 35 struct class_device cdev; 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 class_device_to_raid_internal(cdev) ({ \ 54 struct attribute_container *ac = \ 55 attribute_container_classdev_to_container(cdev); \ 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 (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 class_device *cdev) 80 { 81 struct raid_data *rd; 82 83 BUG_ON(class_get_devdata(cdev)); 84 85 rd = kzalloc(sizeof(*rd), GFP_KERNEL); 86 if (!rd) 87 return -ENOMEM; 88 89 INIT_LIST_HEAD(&rd->component_list); 90 class_set_devdata(cdev, rd); 91 92 return 0; 93 } 94 95 static int raid_remove(struct transport_container *tc, struct device *dev, 96 struct class_device *cdev) 97 { 98 struct raid_data *rd = class_get_devdata(cdev); 99 struct raid_component *rc, *next; 100 dev_printk(KERN_ERR, dev, "RAID REMOVE\n"); 101 class_set_devdata(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->cdev.dev, "RAID COMPONENT REMOVE\n"); 105 class_device_unregister(&rc->cdev); 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 < sizeof(raid_states)/sizeof(raid_states[0]); 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_3, "raid3" }, 153 { RAID_LEVEL_4, "raid4" }, 154 { RAID_LEVEL_5, "raid5" }, 155 { RAID_LEVEL_50, "raid50" }, 156 { RAID_LEVEL_6, "raid6" }, 157 }; 158 159 static const char *raid_level_name(enum raid_level level) 160 { 161 int i; 162 char *name = NULL; 163 164 for (i = 0; i < sizeof(raid_levels)/sizeof(raid_levels[0]); i++) { 165 if (raid_levels[i].value == level) { 166 name = raid_levels[i].name; 167 break; 168 } 169 } 170 return name; 171 } 172 173 #define raid_attr_show_internal(attr, fmt, var, code) \ 174 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf) \ 175 { \ 176 struct raid_data *rd = class_get_devdata(cdev); \ 177 code \ 178 return snprintf(buf, 20, #fmt "\n", var); \ 179 } 180 181 #define raid_attr_ro_states(attr, states, code) \ 182 raid_attr_show_internal(attr, %s, name, \ 183 const char *name; \ 184 code \ 185 name = raid_##states##_name(rd->attr); \ 186 ) \ 187 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 188 189 190 #define raid_attr_ro_internal(attr, code) \ 191 raid_attr_show_internal(attr, %d, rd->attr, code) \ 192 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 193 194 #define ATTR_CODE(attr) \ 195 struct raid_internal *i = class_device_to_raid_internal(cdev); \ 196 if (i->f->get_##attr) \ 197 i->f->get_##attr(cdev->dev); 198 199 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 200 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 201 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ) 202 #define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 203 204 205 raid_attr_ro_state(level); 206 raid_attr_ro_fn(resync); 207 raid_attr_ro_state_fn(state); 208 209 static void raid_component_release(struct class_device *cdev) 210 { 211 struct raid_component *rc = container_of(cdev, struct raid_component, 212 cdev); 213 dev_printk(KERN_ERR, rc->cdev.dev, "COMPONENT RELEASE\n"); 214 put_device(rc->cdev.dev); 215 kfree(rc); 216 } 217 218 void raid_component_add(struct raid_template *r,struct device *raid_dev, 219 struct device *component_dev) 220 { 221 struct class_device *cdev = 222 attribute_container_find_class_device(&r->raid_attrs.ac, 223 raid_dev); 224 struct raid_component *rc; 225 struct raid_data *rd = class_get_devdata(cdev); 226 227 rc = kzalloc(sizeof(*rc), GFP_KERNEL); 228 if (!rc) 229 return; 230 231 INIT_LIST_HEAD(&rc->node); 232 class_device_initialize(&rc->cdev); 233 rc->cdev.release = raid_component_release; 234 rc->cdev.dev = get_device(component_dev); 235 rc->num = rd->component_count++; 236 237 snprintf(rc->cdev.class_id, sizeof(rc->cdev.class_id), 238 "component-%d", rc->num); 239 list_add_tail(&rc->node, &rd->component_list); 240 rc->cdev.parent = cdev; 241 rc->cdev.class = &raid_class.class; 242 class_device_add(&rc->cdev); 243 } 244 EXPORT_SYMBOL(raid_component_add); 245 246 struct raid_template * 247 raid_class_attach(struct raid_function_template *ft) 248 { 249 struct raid_internal *i = kzalloc(sizeof(struct raid_internal), 250 GFP_KERNEL); 251 int count = 0; 252 253 if (unlikely(!i)) 254 return NULL; 255 256 i->f = ft; 257 258 i->r.raid_attrs.ac.class = &raid_class.class; 259 i->r.raid_attrs.ac.match = raid_match; 260 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 261 262 attribute_container_register(&i->r.raid_attrs.ac); 263 264 i->attrs[count++] = &class_device_attr_level; 265 i->attrs[count++] = &class_device_attr_resync; 266 i->attrs[count++] = &class_device_attr_state; 267 268 i->attrs[count] = NULL; 269 BUG_ON(count > RAID_NUM_ATTRS); 270 271 return &i->r; 272 } 273 EXPORT_SYMBOL(raid_class_attach); 274 275 void 276 raid_class_release(struct raid_template *r) 277 { 278 struct raid_internal *i = to_raid_internal(r); 279 280 attribute_container_unregister(&i->r.raid_attrs.ac); 281 282 kfree(i); 283 } 284 EXPORT_SYMBOL(raid_class_release); 285 286 static __init int raid_init(void) 287 { 288 return transport_class_register(&raid_class); 289 } 290 291 static __exit void raid_exit(void) 292 { 293 transport_class_unregister(&raid_class); 294 } 295 296 MODULE_AUTHOR("James Bottomley"); 297 MODULE_DESCRIPTION("RAID device class"); 298 MODULE_LICENSE("GPL"); 299 300 module_init(raid_init); 301 module_exit(raid_exit); 302 303