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 23struct 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 33struct 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 60static 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 return 0; 77} 78 79static int raid_setup(struct transport_container *tc, struct device *dev, 80 struct device *cdev) 81{ 82 struct raid_data *rd; 83 84 BUG_ON(dev_get_drvdata(cdev)); 85 86 rd = kzalloc(sizeof(*rd), GFP_KERNEL); 87 if (!rd) 88 return -ENOMEM; 89 90 INIT_LIST_HEAD(&rd->component_list); 91 dev_set_drvdata(cdev, rd); 92 93 return 0; 94} 95 96static int raid_remove(struct transport_container *tc, struct device *dev, 97 struct device *cdev) 98{ 99 struct raid_data *rd = dev_get_drvdata(cdev); 100 struct raid_component *rc, *next; 101 dev_printk(KERN_ERR, dev, "RAID REMOVE\n"); 102 dev_set_drvdata(cdev, NULL); 103 list_for_each_entry_safe(rc, next, &rd->component_list, node) { 104 list_del(&rc->node); 105 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n"); 106 device_unregister(&rc->dev); 107 } 108 dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n"); 109 kfree(rd); 110 return 0; 111} 112 113static DECLARE_TRANSPORT_CLASS(raid_class, 114 "raid_devices", 115 raid_setup, 116 raid_remove, 117 NULL); 118 119static const struct { 120 enum raid_state value; 121 char *name; 122} raid_states[] = { 123 { RAID_STATE_UNKNOWN, "unknown" }, 124 { RAID_STATE_ACTIVE, "active" }, 125 { RAID_STATE_DEGRADED, "degraded" }, 126 { RAID_STATE_RESYNCING, "resyncing" }, 127 { RAID_STATE_OFFLINE, "offline" }, 128}; 129 130static const char *raid_state_name(enum raid_state state) 131{ 132 int i; 133 char *name = NULL; 134 135 for (i = 0; i < ARRAY_SIZE(raid_states); i++) { 136 if (raid_states[i].value == state) { 137 name = raid_states[i].name; 138 break; 139 } 140 } 141 return name; 142} 143 144static struct { 145 enum raid_level value; 146 char *name; 147} raid_levels[] = { 148 { RAID_LEVEL_UNKNOWN, "unknown" }, 149 { RAID_LEVEL_LINEAR, "linear" }, 150 { RAID_LEVEL_0, "raid0" }, 151 { RAID_LEVEL_1, "raid1" }, 152 { RAID_LEVEL_10, "raid10" }, 153 { RAID_LEVEL_1E, "raid1e" }, 154 { RAID_LEVEL_3, "raid3" }, 155 { RAID_LEVEL_4, "raid4" }, 156 { RAID_LEVEL_5, "raid5" }, 157 { RAID_LEVEL_50, "raid50" }, 158 { RAID_LEVEL_6, "raid6" }, 159}; 160 161static 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) \ 176static 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) \ 186raid_attr_show_internal(attr, %s, name, \ 187 const char *name; \ 188 code \ 189 name = raid_##states##_name(rd->attr); \ 190) \ 191static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 192 193 194#define raid_attr_ro_internal(attr, code) \ 195raid_attr_show_internal(attr, %d, rd->attr, code) \ 196static 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 209raid_attr_ro_state(level); 210raid_attr_ro_fn(resync); 211raid_attr_ro_state_fn(state); 212 213static 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 222int 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 251err_out: 252 list_del(&rc->node); 253 rd->component_count--; 254 put_device(component_dev); 255 kfree(rc); 256 return err; 257} 258EXPORT_SYMBOL(raid_component_add); 259 260struct raid_template * 261raid_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} 287EXPORT_SYMBOL(raid_class_attach); 288 289void 290raid_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} 298EXPORT_SYMBOL(raid_class_release); 299 300static __init int raid_init(void) 301{ 302 return transport_class_register(&raid_class); 303} 304 305static __exit void raid_exit(void) 306{ 307 transport_class_unregister(&raid_class); 308} 309 310MODULE_AUTHOR("James Bottomley"); 311MODULE_DESCRIPTION("RAID device class"); 312MODULE_LICENSE("GPL"); 313 314module_init(raid_init); 315module_exit(raid_exit); 316