aboutsummaryrefslogtreecommitdiffstats
path: root/fs/btrfs/sysfs.c
blob: 300076e66765c282ab8973ad49b0ebf802a1e7c8 (plain) (blame)
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
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
/*
 * Copyright (C) 2007 Oracle.  All rights reserved.
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public
 * License v2 as published by the Free Software Foundation.
 *
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
 * General Public License for more details.
 *
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the
 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
 * Boston, MA 021110-1307, USA.
 */

#include <linux/sched.h>
#include <linux/slab.h>
#include <linux/spinlock.h>
#include <linux/completion.h>
#include <linux/buffer_head.h>
#include <linux/module.h>
#include <linux/kobject.h>

#include "ctree.h"
#include "disk-io.h"
#include "transaction.h"

static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)btrfs_root_used(&root->root_item));
}

static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)btrfs_root_limit(&root->root_item));
}

static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
{

	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
}

static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
}

static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
{
	return snprintf(buf, PAGE_SIZE, "%llu\n",
		(unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
}

/* this is for root attrs (subvols/snapshots) */
struct btrfs_root_attr {
	struct attribute attr;
	ssize_t (*show)(struct btrfs_root *, char *);
	ssize_t (*store)(struct btrfs_root *, const char *, size_t);
};

#define ROOT_ATTR(name, mode, show, store) \
static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, show, store)

ROOT_ATTR(blocks_used,	0444,	root_blocks_used_show,	NULL);
ROOT_ATTR(block_limit,	0644,	root_block_limit_show,	NULL);

static struct attribute *btrfs_root_attrs[] = {
	&btrfs_root_attr_blocks_used.attr,
	&btrfs_root_attr_block_limit.attr,
	NULL,
};

/* this is for super attrs (actual full fs) */
struct btrfs_super_attr {
	struct attribute attr;
	ssize_t (*show)(struct btrfs_fs_info *, char *);
	ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
};

#define SUPER_ATTR(name, mode, show, store) \
static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, show, store)

SUPER_ATTR(blocks_used,		0444,	super_blocks_used_show,		NULL);
SUPER_ATTR(total_blocks,	0444,	super_total_blocks_show,	NULL);
SUPER_ATTR(blocksize,		0444,	super_blocksize_show,		NULL);

static struct attribute *btrfs_super_attrs[] = {
	&btrfs_super_attr_blocks_used.attr,
	&btrfs_super_attr_total_blocks.attr,
	&btrfs_super_attr_blocksize.attr,
	NULL,
};

static ssize_t btrfs_super_attr_show(struct kobject *kobj,
				    struct attribute *attr, char *buf)
{
	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
						super_kobj);
	struct btrfs_super_attr *a = container_of(attr,
						  struct btrfs_super_attr,
						  attr);

	return a->show ? a->show(fs, buf) : 0;
}

static ssize_t btrfs_super_attr_store(struct kobject *kobj,
				     struct attribute *attr,
				     const char *buf, size_t len)
{
	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
						super_kobj);
	struct btrfs_super_attr *a = container_of(attr,
						  struct btrfs_super_attr,
						  attr);

	return a->store ? a->store(fs, buf, len) : 0;
}

static ssize_t btrfs_root_attr_show(struct kobject *kobj,
				    struct attribute *attr, char *buf)
{
	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
						root_kobj);
	struct btrfs_root_attr *a = container_of(attr,
						 struct btrfs_root_attr,
						 attr);

	return a->show ? a->show(root, buf) : 0;
}

static ssize_t btrfs_root_attr_store(struct kobject *kobj,
				     struct attribute *attr,
				     const char *buf, size_t len)
{
	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
						root_kobj);
	struct btrfs_root_attr *a = container_of(attr,
						 struct btrfs_root_attr,
						 attr);
	return a->store ? a->store(root, buf, len) : 0;
}

static void btrfs_super_release(struct kobject *kobj)
{
	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
						super_kobj);
	complete(&fs->kobj_unregister);
}

static void btrfs_root_release(struct kobject *kobj)
{
	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
						root_kobj);
	complete(&root->kobj_unregister);
}

static struct sysfs_ops btrfs_super_attr_ops = {
	.show	= btrfs_super_attr_show,
	.store	= btrfs_super_attr_store,
};

static struct sysfs_ops btrfs_root_attr_ops = {
	.show	= btrfs_root_attr_show,
	.store	= btrfs_root_attr_store,
};

static struct kobj_type btrfs_root_ktype = {
	.default_attrs	= btrfs_root_attrs,
	.sysfs_ops	= &btrfs_root_attr_ops,
	.release	= btrfs_root_release,
};

static struct kobj_type btrfs_super_ktype = {
	.default_attrs	= btrfs_super_attrs,
	.sysfs_ops	= &btrfs_super_attr_ops,
	.release	= btrfs_super_release,
};

/* /sys/fs/btrfs/ entry */
static struct kset *btrfs_kset;

int btrfs_sysfs_add_super(struct btrfs_fs_info *fs)
{
	int error;
	char *name;
	char c;
	int len = strlen(fs->sb->s_id) + 1;
	int i;

	name = kmalloc(len, GFP_NOFS);
	if (!name) {
		error = -ENOMEM;
		goto fail;
	}

	for (i = 0; i < len; i++) {
		c = fs->sb->s_id[i];
		if (c == '/' || c == '\\')
			c = '!';
		name[i] = c;
	}
	name[len] = '\0';

	fs->super_kobj.kset = btrfs_kset;
	error = kobject_init_and_add(&fs->super_kobj, &btrfs_super_ktype,
				     NULL, "%s", name);
	if (error)
		goto fail;

	kfree(name);
	return 0;

fail:
	kfree(name);
	printk(KERN_ERR "btrfs: sysfs creation for super failed\n");
	return error;
}

int btrfs_sysfs_add_root(struct btrfs_root *root)
{
	int error;

	error = kobject_init_and_add(&root->root_kobj, &btrfs_root_ktype,
				     &root->fs_info->super_kobj,
				     "%s", root->name);
	if (error)
		goto fail;

	return 0;

fail:
	printk(KERN_ERR "btrfs: sysfs creation for root failed\n");
	return error;
}

void btrfs_sysfs_del_root(struct btrfs_root *root)
{
	kobject_put(&root->root_kobj);
	wait_for_completion(&root->kobj_unregister);
}

void btrfs_sysfs_del_super(struct btrfs_fs_info *fs)
{
	kobject_put(&fs->super_kobj);
	wait_for_completion(&fs->kobj_unregister);
}

int btrfs_init_sysfs(void)
{
	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
	if (!btrfs_kset)
		return -ENOMEM;
	return 0;
}

void btrfs_exit_sysfs(void)
{
	kset_unregister(btrfs_kset);
}