1 /* 2 * RAID Attributes 3 */ 4 #include <linux/init.h> 5 #include <linux/module.h> 6 #include <linux/list.h> 7 #include <linux/raid_class.h> 8 #include <scsi/scsi_device.h> 9 #include <scsi/scsi_host.h> 10 11 #define RAID_NUM_ATTRS 3 12 13 struct raid_internal { 14 struct raid_template r; 15 struct raid_function_template *f; 16 /* The actual attributes */ 17 struct class_device_attribute private_attrs[RAID_NUM_ATTRS]; 18 /* The array of null terminated pointers to attributes 19 * needed by scsi_sysfs.c */ 20 struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1]; 21 }; 22 23 struct raid_component { 24 struct list_head node; 25 struct device *dev; 26 int num; 27 }; 28 29 #define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r) 30 31 #define tc_to_raid_internal(tcont) ({ \ 32 struct raid_template *r = \ 33 container_of(tcont, struct raid_template, raid_attrs); \ 34 to_raid_internal(r); \ 35 }) 36 37 #define ac_to_raid_internal(acont) ({ \ 38 struct transport_container *tc = \ 39 container_of(acont, struct transport_container, ac); \ 40 tc_to_raid_internal(tc); \ 41 }) 42 43 #define class_device_to_raid_internal(cdev) ({ \ 44 struct attribute_container *ac = \ 45 attribute_container_classdev_to_container(cdev); \ 46 ac_to_raid_internal(ac); \ 47 }) 48 49 50 static int raid_match(struct attribute_container *cont, struct device *dev) 51 { 52 /* We have to look for every subsystem that could house 53 * emulated RAID devices, so start with SCSI */ 54 struct raid_internal *i = ac_to_raid_internal(cont); 55 56 if (scsi_is_sdev_device(dev)) { 57 struct scsi_device *sdev = to_scsi_device(dev); 58 59 if (i->f->cookie != sdev->host->hostt) 60 return 0; 61 62 return i->f->is_raid(dev); 63 } 64 /* FIXME: look at other subsystems too */ 65 return 0; 66 } 67 68 static int raid_setup(struct transport_container *tc, struct device *dev, 69 struct class_device *cdev) 70 { 71 struct raid_data *rd; 72 73 BUG_ON(class_get_devdata(cdev)); 74 75 rd = kmalloc(sizeof(*rd), GFP_KERNEL); 76 if (!rd) 77 return -ENOMEM; 78 79 memset(rd, 0, sizeof(*rd)); 80 INIT_LIST_HEAD(&rd->component_list); 81 class_set_devdata(cdev, rd); 82 83 return 0; 84 } 85 86 static int raid_remove(struct transport_container *tc, struct device *dev, 87 struct class_device *cdev) 88 { 89 struct raid_data *rd = class_get_devdata(cdev); 90 struct raid_component *rc, *next; 91 class_set_devdata(cdev, NULL); 92 list_for_each_entry_safe(rc, next, &rd->component_list, node) { 93 char buf[40]; 94 snprintf(buf, sizeof(buf), "component-%d", rc->num); 95 list_del(&rc->node); 96 sysfs_remove_link(&cdev->kobj, buf); 97 kfree(rc); 98 } 99 kfree(class_get_devdata(cdev)); 100 return 0; 101 } 102 103 static DECLARE_TRANSPORT_CLASS(raid_class, 104 "raid_devices", 105 raid_setup, 106 raid_remove, 107 NULL); 108 109 static struct { 110 enum raid_state value; 111 char *name; 112 } raid_states[] = { 113 { RAID_ACTIVE, "active" }, 114 { RAID_DEGRADED, "degraded" }, 115 { RAID_RESYNCING, "resyncing" }, 116 { RAID_OFFLINE, "offline" }, 117 }; 118 119 static const char *raid_state_name(enum raid_state state) 120 { 121 int i; 122 char *name = NULL; 123 124 for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) { 125 if (raid_states[i].value == state) { 126 name = raid_states[i].name; 127 break; 128 } 129 } 130 return name; 131 } 132 133 134 #define raid_attr_show_internal(attr, fmt, var, code) \ 135 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf) \ 136 { \ 137 struct raid_data *rd = class_get_devdata(cdev); \ 138 code \ 139 return snprintf(buf, 20, #fmt "\n", var); \ 140 } 141 142 #define raid_attr_ro_states(attr, states, code) \ 143 raid_attr_show_internal(attr, %s, name, \ 144 const char *name; \ 145 code \ 146 name = raid_##states##_name(rd->attr); \ 147 ) \ 148 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 149 150 151 #define raid_attr_ro_internal(attr, code) \ 152 raid_attr_show_internal(attr, %d, rd->attr, code) \ 153 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 154 155 #define ATTR_CODE(attr) \ 156 struct raid_internal *i = class_device_to_raid_internal(cdev); \ 157 if (i->f->get_##attr) \ 158 i->f->get_##attr(cdev->dev); 159 160 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 161 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 162 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 163 164 raid_attr_ro(level); 165 raid_attr_ro_fn(resync); 166 raid_attr_ro_state(state); 167 168 void raid_component_add(struct raid_template *r,struct device *raid_dev, 169 struct device *component_dev) 170 { 171 struct class_device *cdev = 172 attribute_container_find_class_device(&r->raid_attrs.ac, 173 raid_dev); 174 struct raid_component *rc; 175 struct raid_data *rd = class_get_devdata(cdev); 176 char buf[40]; 177 178 rc = kmalloc(sizeof(*rc), GFP_KERNEL); 179 if (!rc) 180 return; 181 182 INIT_LIST_HEAD(&rc->node); 183 rc->dev = component_dev; 184 rc->num = rd->component_count++; 185 186 snprintf(buf, sizeof(buf), "component-%d", rc->num); 187 list_add_tail(&rc->node, &rd->component_list); 188 sysfs_create_link(&cdev->kobj, &component_dev->kobj, buf); 189 } 190 EXPORT_SYMBOL(raid_component_add); 191 192 struct raid_template * 193 raid_class_attach(struct raid_function_template *ft) 194 { 195 struct raid_internal *i = kmalloc(sizeof(struct raid_internal), 196 GFP_KERNEL); 197 int count = 0; 198 199 if (unlikely(!i)) 200 return NULL; 201 202 memset(i, 0, sizeof(*i)); 203 204 i->f = ft; 205 206 i->r.raid_attrs.ac.class = &raid_class.class; 207 i->r.raid_attrs.ac.match = raid_match; 208 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 209 210 attribute_container_register(&i->r.raid_attrs.ac); 211 212 i->attrs[count++] = &class_device_attr_level; 213 i->attrs[count++] = &class_device_attr_resync; 214 i->attrs[count++] = &class_device_attr_state; 215 216 i->attrs[count] = NULL; 217 BUG_ON(count > RAID_NUM_ATTRS); 218 219 return &i->r; 220 } 221 EXPORT_SYMBOL(raid_class_attach); 222 223 void 224 raid_class_release(struct raid_template *r) 225 { 226 struct raid_internal *i = to_raid_internal(r); 227 228 attribute_container_unregister(&i->r.raid_attrs.ac); 229 230 kfree(i); 231 } 232 EXPORT_SYMBOL(raid_class_release); 233 234 static __init int raid_init(void) 235 { 236 return transport_class_register(&raid_class); 237 } 238 239 static __exit void raid_exit(void) 240 { 241 transport_class_unregister(&raid_class); 242 } 243 244 MODULE_AUTHOR("James Bottomley"); 245 MODULE_DESCRIPTION("RAID device class"); 246 MODULE_LICENSE("GPL"); 247 248 module_init(raid_init); 249 module_exit(raid_exit); 250 251