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1// SPDX-License-Identifier: GPL-2.0-only2/*3 * raid_class.c - implementation of a simple raid visualisation class4 *5 * Copyright (c) 2005 - James Bottomley <James.Bottomley@steeleye.com>6 *7 * This class is designed to allow raid attributes to be visualised and8 * manipulated in a form independent of the underlying raid. Ultimately this9 * 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 321 22struct 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 32struct 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 59static int raid_match(struct attribute_container *cont, struct device *dev)60{61 /* We have to look for every subsystem that could house62 * 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 77static 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 94static 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 111static DECLARE_TRANSPORT_CLASS(raid_class,112 "raid_devices",113 raid_setup,114 raid_remove,115 NULL);116 117static 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 128static 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 142static 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 160static 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) \175static 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) \185raid_attr_show_internal(attr, %s, name, \186 const char *name; \187 code \188 name = raid_##states##_name(rd->attr); \189) \190static DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)191 192 193#define raid_attr_ro_internal(attr, code) \194raid_attr_show_internal(attr, %d, rd->attr, code) \195static 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 208raid_attr_ro_state(level);209raid_attr_ro_fn(resync);210raid_attr_ro_state_fn(state);211 212struct raid_template *213raid_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}239EXPORT_SYMBOL(raid_class_attach);240 241void242raid_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}250EXPORT_SYMBOL(raid_class_release);251 252static __init int raid_init(void)253{254 return transport_class_register(&raid_class);255}256 257static __exit void raid_exit(void)258{259 transport_class_unregister(&raid_class);260}261 262MODULE_AUTHOR("James Bottomley");263MODULE_DESCRIPTION("RAID device class");264MODULE_LICENSE("GPL");265 266module_init(raid_init);267module_exit(raid_exit);268 269