summaryrefslogtreecommitdiffstats
path: root/drivers/scsi/raid_class.c
blob: f1ea5027865f5851310769b08e0f5b53df163f71 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
/*
 * RAID Attributes
 */
#include <linux/init.h>
#include <linux/module.h>
#include <linux/list.h>
#include <linux/raid_class.h>
#include <scsi/scsi_device.h>
#include <scsi/scsi_host.h>

#define RAID_NUM_ATTRS	3

struct raid_internal {
	struct raid_template r;
	struct raid_function_template *f;
	/* The actual attributes */
	struct class_device_attribute private_attrs[RAID_NUM_ATTRS];
	/* The array of null terminated pointers to attributes 
	 * needed by scsi_sysfs.c */
	struct class_device_attribute *attrs[RAID_NUM_ATTRS + 1];
};

struct raid_component {
	struct list_head node;
	struct device *dev;
	int num;
};

#define to_raid_internal(tmpl)	container_of(tmpl, struct raid_internal, r)

#define tc_to_raid_internal(tcont) ({					\
	struct raid_template *r =					\
		container_of(tcont, struct raid_template, raid_attrs);	\
	to_raid_internal(r);						\
})

#define ac_to_raid_internal(acont) ({					\
	struct transport_container *tc =				\
		container_of(acont, struct transport_container, ac);	\
	tc_to_raid_internal(tc);					\
})

#define class_device_to_raid_internal(cdev) ({				\
	struct attribute_container *ac =				\
		attribute_container_classdev_to_container(cdev);	\
	ac_to_raid_internal(ac);					\
})
	

static int raid_match(struct attribute_container *cont, struct device *dev)
{
	/* We have to look for every subsystem that could house
	 * emulated RAID devices, so start with SCSI */
	struct raid_internal *i = ac_to_raid_internal(cont);

	if (scsi_is_sdev_device(dev)) {
		struct scsi_device *sdev = to_scsi_device(dev);

		if (i->f->cookie != sdev->host->hostt)
			return 0;

		return i->f->is_raid(dev);
	}
	/* FIXME: look at other subsystems too */
	return 0;
}

static int raid_setup(struct transport_container *tc, struct device *dev,
		       struct class_device *cdev)
{
	struct raid_data *rd;

	BUG_ON(class_get_devdata(cdev));

	rd = kmalloc(sizeof(*rd), GFP_KERNEL);
	if (!rd)
		return -ENOMEM;

	memset(rd, 0, sizeof(*rd));
	INIT_LIST_HEAD(&rd->component_list);
	class_set_devdata(cdev, rd);
		
	return 0;
}

static int raid_remove(struct transport_container *tc, struct device *dev,
		       struct class_device *cdev)
{
	struct raid_data *rd = class_get_devdata(cdev);
	struct raid_component *rc, *next;
	class_set_devdata(cdev, NULL);
	list_for_each_entry_safe(rc, next, &rd->component_list, node) {
		char buf[40];
		snprintf(buf, sizeof(buf), "component-%d", rc->num);
		list_del(&rc->node);
		sysfs_remove_link(&cdev->kobj, buf);
		kfree(rc);
	}
	kfree(class_get_devdata(cdev));
	return 0;
}

static DECLARE_TRANSPORT_CLASS(raid_class,
			       "raid_devices",
			       raid_setup,
			       raid_remove,
			       NULL);

static struct {
	enum raid_state	value;
	char		*name;
} raid_states[] = {
	{ RAID_ACTIVE, "active" },
	{ RAID_DEGRADED, "degraded" },
	{ RAID_RESYNCING, "resyncing" },
	{ RAID_OFFLINE, "offline" },
};

static const char *raid_state_name(enum raid_state state)
{
	int i;
	char *name = NULL;

	for (i = 0; i < sizeof(raid_states)/sizeof(raid_states[0]); i++) {
		if (raid_states[i].value == state) {
			name = raid_states[i].name;
			break;
		}
	}
	return name;
}


#define raid_attr_show_internal(attr, fmt, var, code)			\
static ssize_t raid_show_##attr(struct class_device *cdev, char *buf)	\
{									\
	struct raid_data *rd = class_get_devdata(cdev);			\
	code								\
	return snprintf(buf, 20, #fmt "\n", var);			\
}

#define raid_attr_ro_states(attr, states, code)				\
raid_attr_show_internal(attr, %s, name,					\
	const char *name;						\
	code								\
	name = raid_##states##_name(rd->attr);				\
)									\
static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)


#define raid_attr_ro_internal(attr, code)				\
raid_attr_show_internal(attr, %d, rd->attr, code)			\
static CLASS_DEVICE_ATTR(attr, S_IRUGO, raid_show_##attr, NULL)

#define ATTR_CODE(attr)							\
	struct raid_internal *i = class_device_to_raid_internal(cdev);	\
	if (i->f->get_##attr)						\
		i->f->get_##attr(cdev->dev);

#define raid_attr_ro(attr)	raid_attr_ro_internal(attr, )
#define raid_attr_ro_fn(attr)	raid_attr_ro_internal(attr, ATTR_CODE(attr))
#define raid_attr_ro_state(attr)	raid_attr_ro_states(attr, attr, ATTR_CODE(attr))

raid_attr_ro(level);
raid_attr_ro_fn(resync);
raid_attr_ro_state(state);

void raid_component_add(struct raid_template *r,struct device *raid_dev,
			struct device *component_dev)
{
	struct class_device *cdev =
		attribute_container_find_class_device(&r->raid_attrs.ac,
						      raid_dev);
	struct raid_component *rc;
	struct raid_data *rd = class_get_devdata(cdev);
	char buf[40];

	rc = kmalloc(sizeof(*rc), GFP_KERNEL);
	if (!rc)
		return;

	INIT_LIST_HEAD(&rc->node);
	rc->dev = component_dev;
	rc->num = rd->component_count++;

	snprintf(buf, sizeof(buf), "component-%d", rc->num);
	list_add_tail(&rc->node, &rd->component_list);
	sysfs_create_link(&cdev->kobj, &component_dev->kobj, buf);
}
EXPORT_SYMBOL(raid_component_add);

struct raid_template *
raid_class_attach(struct raid_function_template *ft)
{
	struct raid_internal *i = kmalloc(sizeof(struct raid_internal),
					  GFP_KERNEL);
	int count = 0;

	if (unlikely(!i))
		return NULL;

	memset(i, 0, sizeof(*i));

	i->f = ft;

	i->r.raid_attrs.ac.class = &raid_class.class;
	i->r.raid_attrs.ac.match = raid_match;
	i->r.raid_attrs.ac.attrs = &i->attrs[0];

	attribute_container_register(&i->r.raid_attrs.ac);

	i->attrs[count++] = &class_device_attr_level;
	i->attrs[count++] = &class_device_attr_resync;
	i->attrs[count++] = &class_device_attr_state;

	i->attrs[count] = NULL;
	BUG_ON(count > RAID_NUM_ATTRS);

	return &i->r;
}
EXPORT_SYMBOL(raid_class_attach);

void
raid_class_release(struct raid_template *r)
{
	struct raid_internal *i = to_raid_internal(r);

	attribute_container_unregister(&i->r.raid_attrs.ac);

	kfree(i);
}
EXPORT_SYMBOL(raid_class_release);

static __init int raid_init(void)
{
	return transport_class_register(&raid_class);
}

static __exit void raid_exit(void)
{
	transport_class_unregister(&raid_class);
}

MODULE_AUTHOR("James Bottomley");
MODULE_DESCRIPTION("RAID device class");
MODULE_LICENSE("GPL");

module_init(raid_init);
module_exit(raid_exit);

OpenPOWER on IntegriCloud