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(size: sizeof(*rd), GFP_KERNEL); |
85 | if (!rd) |
86 | return -ENOMEM; |
87 | |
88 | INIT_LIST_HEAD(list: &rd->component_list); |
89 | dev_set_drvdata(dev: cdev, data: 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(dev: cdev); |
98 | struct raid_component *rc, *next; |
99 | dev_printk(KERN_ERR, dev, "RAID REMOVE\n" ); |
100 | dev_set_drvdata(dev: cdev, NULL); |
101 | list_for_each_entry_safe(rc, next, &rd->component_list, node) { |
102 | list_del(entry: &rc->node); |
103 | dev_printk(KERN_ERR, rc->dev.parent, "RAID COMPONENT REMOVE\n" ); |
104 | device_unregister(dev: &rc->dev); |
105 | } |
106 | dev_printk(KERN_ERR, dev, "RAID REMOVE DONE\n" ); |
107 | kfree(objp: 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(size: 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(cont: &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(objp: 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 | |