1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * raid_class.c - implementation of a simple raid visualisation class 4 * 5 * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com> 6 * 7 * This class is designed to allow raid attributes to be visualised and 8 * manipulated in a form independent of the underlying raid. Ultimately this 9 * should work for both hardware and software raids. 10 */ 11 #include <linux/init.h> 12 #include <linux/module.h> 13 #include <linux/list.h> 14 #include <linux/slab.h> 15 #include <linux/string.h> 16 #include <linux/raid_class.h> 17 #include <scsi/scsi_device.h> 18 #include <scsi/scsi_host.h> 19 20 #define RAID_NUM_ATTRS 3 21 22 struct raid_internal { 23 struct raid_template r; 24 struct raid_function_template *f; 25 /* The actual attributes */ 26 struct device_attribute private_attrs[RAID_NUM_ATTRS]; 27 /* The array of null terminated pointers to attributes 28 * needed by scsi_sysfs.c */ 29 struct device_attribute *attrs[RAID_NUM_ATTRS + 1]; 30 }; 31 32 struct raid_component { 33 struct list_head node; 34 struct device dev; 35 int num; 36 }; 37 38 #define to_raid_internal(tmpl) container_of(tmpl, struct raid_internal, r) 39 40 #define tc_to_raid_internal(tcont) ({ \ 41 struct raid_template *r = \ 42 container_of(tcont, struct raid_template, raid_attrs); \ 43 to_raid_internal(r); \ 44 }) 45 46 #define ac_to_raid_internal(acont) ({ \ 47 struct transport_container *tc = \ 48 container_of(acont, struct transport_container, ac); \ 49 tc_to_raid_internal(tc); \ 50 }) 51 52 #define device_to_raid_internal(dev) ({ \ 53 struct attribute_container *ac = \ 54 attribute_container_classdev_to_container(dev); \ 55 ac_to_raid_internal(ac); \ 56 }) 57 58 59 static int raid_match(struct attribute_container *cont, struct device *dev) 60 { 61 /* We have to look for every subsystem that could house 62 * emulated RAID devices, so start with SCSI */ 63 struct raid_internal *i = ac_to_raid_internal(cont); 64 65 if (IS_ENABLED(CONFIG_SCSI) && scsi_is_sdev_device(dev)) { 66 struct scsi_device *sdev = to_scsi_device(dev); 67 68 if (i->f->cookie != sdev->host->hostt) 69 return 0; 70 71 return i->f->is_raid(dev); 72 } 73 /* FIXME: look at other subsystems too */ 74 return 0; 75 } 76 77 static int raid_setup(struct transport_container *tc, struct device *dev, 78 struct device *cdev) 79 { 80 struct raid_data *rd; 81 82 BUG_ON(dev_get_drvdata(cdev)); 83 84 rd = kzalloc(sizeof(*rd), GFP_KERNEL); 85 if (!rd) 86 return -ENOMEM; 87 88 INIT_LIST_HEAD(&rd->component_list); 89 dev_set_drvdata(cdev, rd); 90 91 return 0; 92 } 93 94 static int raid_remove(struct transport_container *tc, struct device *dev, 95 struct device *cdev) 96 { 97 struct raid_data *rd = dev_get_drvdata(cdev); 98 struct raid_component *rc, *next; 99 dev_printk(KERN_ERR, dev, "RAID REMOVE\n"); 100 dev_set_drvdata(cdev, NULL); 101 list_for_each_entry_safe(rc, next, &rd->component_list, node) { 102 list_del(&rc->node); 103 dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n"); 104 device_unregister(&rc->dev); 105 } 106 dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n"); 107 kfree(rd); 108 return 0; 109 } 110 111 static DECLARE_TRANSPORT_CLASS(raid_class, 112 "raid_devices", 113 raid_setup, 114 raid_remove, 115 NULL); 116 117 static const struct { 118 enum raid_state value; 119 char *name; 120 } raid_states[] = { 121 { RAID_STATE_UNKNOWN, "unknown" }, 122 { RAID_STATE_ACTIVE, "active" }, 123 { RAID_STATE_DEGRADED, "degraded" }, 124 { RAID_STATE_RESYNCING, "resyncing" }, 125 { RAID_STATE_OFFLINE, "offline" }, 126 }; 127 128 static const char *raid_state_name(enum raid_state state) 129 { 130 int i; 131 char *name = NULL; 132 133 for (i = 0; i < ARRAY_SIZE(raid_states); i++) { 134 if (raid_states[i].value == state) { 135 name = raid_states[i].name; 136 break; 137 } 138 } 139 return name; 140 } 141 142 static struct { 143 enum raid_level value; 144 char *name; 145 } raid_levels[] = { 146 { RAID_LEVEL_UNKNOWN, "unknown" }, 147 { RAID_LEVEL_LINEAR, "linear" }, 148 { RAID_LEVEL_0, "raid0" }, 149 { RAID_LEVEL_1, "raid1" }, 150 { RAID_LEVEL_10, "raid10" }, 151 { RAID_LEVEL_1E, "raid1e" }, 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 { RAID_LEVEL_JBOD, "jbod" }, 158 }; 159 160 static const char *raid_level_name(enum raid_level level) 161 { 162 int i; 163 char *name = NULL; 164 165 for (i = 0; i < ARRAY_SIZE(raid_levels); i++) { 166 if (raid_levels[i].value == level) { 167 name = raid_levels[i].name; 168 break; 169 } 170 } 171 return name; 172 } 173 174 #define raid_attr_show_internal(attr, fmt, var, code) \ 175 static ssize_t raid_show_##attr(struct device *dev, \ 176 struct device_attribute *attr, \ 177 char *buf) \ 178 { \ 179 struct raid_data *rd = dev_get_drvdata(dev); \ 180 code \ 181 return snprintf(buf, 20, #fmt "\n", var); \ 182 } 183 184 #define raid_attr_ro_states(attr, states, code) \ 185 raid_attr_show_internal(attr, %s, name, \ 186 const char *name; \ 187 code \ 188 name = raid_##states##_name(rd->attr); \ 189 ) \ 190 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 191 192 193 #define raid_attr_ro_internal(attr, code) \ 194 raid_attr_show_internal(attr, %d, rd->attr, code) \ 195 static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL) 196 197 #define ATTR_CODE(attr) \ 198 struct raid_internal *i = device_to_raid_internal(dev); \ 199 if (i->f->get_##attr) \ 200 i->f->get_##attr(dev->parent); 201 202 #define raid_attr_ro(attr) raid_attr_ro_internal(attr, ) 203 #define raid_attr_ro_fn(attr) raid_attr_ro_internal(attr, ATTR_CODE(attr)) 204 #define raid_attr_ro_state(attr) raid_attr_ro_states(attr, attr, ) 205 #define raid_attr_ro_state_fn(attr) raid_attr_ro_states(attr, attr, ATTR_CODE(attr)) 206 207 208 raid_attr_ro_state(level); 209 raid_attr_ro_fn(resync); 210 raid_attr_ro_state_fn(state); 211 212 struct raid_template * 213 raid_class_attach(struct raid_function_template *ft) 214 { 215 struct raid_internal *i = kzalloc(sizeof(struct raid_internal), 216 GFP_KERNEL); 217 int count = 0; 218 219 if (unlikely(!i)) 220 return NULL; 221 222 i->f = ft; 223 224 i->r.raid_attrs.ac.class = &raid_class.class; 225 i->r.raid_attrs.ac.match = raid_match; 226 i->r.raid_attrs.ac.attrs = &i->attrs[0]; 227 228 attribute_container_register(&i->r.raid_attrs.ac); 229 230 i->attrs[count++] = &dev_attr_level; 231 i->attrs[count++] = &dev_attr_resync; 232 i->attrs[count++] = &dev_attr_state; 233 234 i->attrs[count] = NULL; 235 BUG_ON(count > RAID_NUM_ATTRS); 236 237 return &i->r; 238 } 239 EXPORT_SYMBOL(raid_class_attach); 240 241 void 242 raid_class_release(struct raid_template *r) 243 { 244 struct raid_internal *i = to_raid_internal(r); 245 246 BUG_ON(attribute_container_unregister(&i->r.raid_attrs.ac)); 247 248 kfree(i); 249 } 250 EXPORT_SYMBOL(raid_class_release); 251 252 static __init int raid_init(void) 253 { 254 return transport_class_register(&raid_class); 255 } 256 257 static __exit void raid_exit(void) 258 { 259 transport_class_unregister(&raid_class); 260 } 261 262 MODULE_AUTHOR("James Bottomley"); 263 MODULE_DESCRIPTION("RAID device class"); 264 MODULE_LICENSE("GPL"); 265 266 module_init(raid_init); 267 module_exit(raid_exit); 268 269