1 /* 2 * RAID Attributes 3 */ 4 #include <linux/init.h> 5 #include <linux/module.h> 6 #include <linux/list.h> 7 #include <linux/slab.h> 8 #include <linux/string.h> 9 #include <linux/raid_class.h> 10 #include <scsi/scsi_device.h> 11 #include <scsi/scsi_host.h> 12 13 #define RAID_NUM_ATTRS 3 14 15 struct raid_internal { 16 struct raid_template r; 17 struct raid_function_template *f; 18 /* The actual attributes */ 19 struct class_device_attribute private_attrs[RAID_NUM_ATTRS]; 20 /* The array of null terminated pointers to attributes 21 * needed by scsi_sysfs.c */ 22 struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1]; 23 }; 24 25 struct raid_component { 26 struct list_head node; 27 struct device *dev; 28 int num; 29 }; 30 31 #define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r) 32 33 #define tc_to_raid_internal(tcont) ({ \ 34 struct raid_template *r = \ 35 container_of(tcont, struct raid_template, raid_attrs); \ 36 to_raid_internal(r); \ 37 }) 38 39 #define ac_to_raid_internal(acont) ({ \ 40 struct transport_container *tc = \ 41 container_of(acont, struct transport_container, ac); \ 42 tc_to_raid_internal(tc); \ 43 }) 44 45 #define class_device_to_raid_internal(cdev) ({ \ 46 struct attribute_container *ac = \ 47 attribute_container_classdev_to_container(cdev); \ 48 ac_to_raid_internal(ac); \ 49 }) 50 51 52 static int raid_match(struct attribute_container *cont, struct device *dev) 53 { 54 /* We have to look for every subsystem that could house 55 * emulated RAID devices, so start with SCSI */ 56 struct raid_internal *i = ac_to_raid_internal(cont); 57 58 if (scsi_is_sdev_device(dev)) { 59 struct scsi_device *sdev = to_scsi_device(dev); 60 61 if (i->f->cookie != sdev->host->hostt) 62 return 0; 63 64 return i->f->is_raid(dev); 65 } 66 /* FIXME: look at other subsystems too */ 67 return 0; 68 } 69 70 static int raid_setup(struct transport_container *tc, struct device *dev, 71 struct class_device *cdev) 72 { 73 struct raid_data *rd; 74 75 BUG_ON(class_get_devdata(cdev)); 76 77 rd = kmalloc(sizeof(*rd), GFP_KERNEL); 78 if (!rd) 79 return -ENOMEM; 80 81 memset(rd, 0, sizeof(*rd)); 82 INIT_LIST_HEAD(&rd->component_list); 83 class_set_devdata(cdev, rd); 84 85 return 0; 86 } 87 88 static int raid_remove(struct transport_container *tc, struct device *dev, 89 struct class_device *cdev) 90 { 91 struct raid_data *rd = class_get_devdata(cdev); 92 struct raid_component *rc, *next; 93 class_set_devdata(cdev, NULL); 94 list_for_each_entry_safe(rc, next, &rd->component_list, node) { 95 char buf[40]; 96 snprintf(buf, sizeof(buf), "component-%d", rc->num); 97 list_del(&rc->node); 98 sysfs_remove_link(&cdev->kobj, buf); 99 kfree(rc); 100 } 101 kfree(class_get_devdata(cdev)); 102 return 0; 103 } 104 105 static DECLARE_TRANSPORT_CLASS(raid_class, 106 "raid_devices", 107 raid_setup, 108 raid_remove, 109 NULL); 110 111 static struct { 112 enum raid_state value; 113 char *name; 114 } raid_states[] = { 115 { RAID_ACTIVE, "active" }, 116 { RAID_DEGRADED, "degraded" }, 117 { RAID_RESYNCING, "resyncing" }, 118 { RAID_OFFLINE, "offline" }, 119 }; 120 121 static const char *raid_state_name(enum raid_state state) 122 { 123 int i; 124 char *name = NULL; 125 126 for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) { 127 if (raid_states[i].value == state) { 128 name = raid_states[i].name; 129 break; 130 } 131 } 132 return name; 133 } 134 135 136 #define raid_attr_show_internal(attr, fmt, var, code) \ 137 static ssize_t raid_show_##attr(struct class_device *cdev, char *buf) \ 138 { \ 139 struct raid_data *rd = class_get_devdata(cdev); \ 140 code \ 141 return snprintf(buf, 20, #fmt "\n", var); \ 142 } 143 144 #define raid_attr_ro_states(attr, states, code) \ 145 raid_attr_show_internal(attr, %s, name, \ 146 const char *name; \ 147 code \ 148 name = raid_##states##_name(rd->attr); \ 149 ) \ 150 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 151 152 153 #define raid_attr_ro_internal(attr, code) \ 154 raid_attr_show_internal(attr, %d, rd->attr, code) \ 155 static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 156 157 #define ATTR_CODE(attr) \ 158 struct raid_internal *i = class_device_to_raid_internal(cdev); \ 159 if (i->f->get_##attr) \ 160 i->f->get_##attr(cdev->dev); 161 162 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 163 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 164 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 165 166 raid_attr_ro(level); 167 raid_attr_ro_fn(resync); 168 raid_attr_ro_state(state); 169 170 void raid_component_add(struct raid_template *r,struct device *raid_dev, 171 struct device *component_dev) 172 { 173 struct class_device *cdev = 174 attribute_container_find_class_device(&r->raid_attrs.ac, 175 raid_dev); 176 struct raid_component *rc; 177 struct raid_data *rd = class_get_devdata(cdev); 178 char buf[40]; 179 180 rc = kmalloc(sizeof(*rc), GFP_KERNEL); 181 if (!rc) 182 return; 183 184 INIT_LIST_HEAD(&rc->node); 185 rc->dev = component_dev; 186 rc->num = rd->component_count++; 187 188 snprintf(buf, sizeof(buf), "component-%d", rc->num); 189 list_add_tail(&rc->node, &rd->component_list); 190 sysfs_create_link(&cdev->kobj, &component_dev->kobj, buf); 191 } 192 EXPORT_SYMBOL(raid_component_add); 193 194 struct raid_template * 195 raid_class_attach(struct raid_function_template *ft) 196 { 197 struct raid_internal *i = kmalloc(sizeof(struct raid_internal), 198 GFP_KERNEL); 199 int count = 0; 200 201 if (unlikely(!i)) 202 return NULL; 203 204 memset(i, 0, sizeof(*i)); 205 206 i->f = ft; 207 208 i->r.raid_attrs.ac.class = &raid_class.class; 209 i->r.raid_attrs.ac.match = raid_match; 210 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 211 212 attribute_container_register(&i->r.raid_attrs.ac); 213 214 i->attrs[count++] = &class_device_attr_level; 215 i->attrs[count++] = &class_device_attr_resync; 216 i->attrs[count++] = &class_device_attr_state; 217 218 i->attrs[count] = NULL; 219 BUG_ON(count > RAID_NUM_ATTRS); 220 221 return &i->r; 222 } 223 EXPORT_SYMBOL(raid_class_attach); 224 225 void 226 raid_class_release(struct raid_template *r) 227 { 228 struct raid_internal *i = to_raid_internal(r); 229 230 attribute_container_unregister(&i->r.raid_attrs.ac); 231 232 kfree(i); 233 } 234 EXPORT_SYMBOL(raid_class_release); 235 236 static __init int raid_init(void) 237 { 238 return transport_class_register(&raid_class); 239 } 240 241 static __exit void raid_exit(void) 242 { 243 transport_class_unregister(&raid_class); 244 } 245 246 MODULE_AUTHOR("James Bottomley"); 247 MODULE_DESCRIPTION("RAID device class"); 248 MODULE_LICENSE("GPL"); 249 250 module_init(raid_init); 251 module_exit(raid_exit); 252 253