xref: /linux/fs/btrfs/sysfs.c (revision 12871a0bd67dd4db4418e1daafcd46e9d329ef10)
1 /*
2  * Copyright (C) 2007 Oracle.  All rights reserved.
3  *
4  * This program is free software; you can redistribute it and/or
5  * modify it under the terms of the GNU General Public
6  * License v2 as published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it will be useful,
9  * but WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
11  * General Public License for more details.
12  *
13  * You should have received a copy of the GNU General Public
14  * License along with this program; if not, write to the
15  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16  * Boston, MA 021110-1307, USA.
17  */
18 
19 #include <linux/sched.h>
20 #include <linux/slab.h>
21 #include <linux/spinlock.h>
22 #include <linux/completion.h>
23 #include <linux/buffer_head.h>
24 #include <linux/module.h>
25 #include <linux/kobject.h>
26 
27 #include "ctree.h"
28 #include "disk-io.h"
29 #include "transaction.h"
30 
31 static ssize_t root_blocks_used_show(struct btrfs_root *root, char *buf)
32 {
33 	return snprintf(buf, PAGE_SIZE, "%llu\n",
34 		(unsigned long long)btrfs_root_used(&root->root_item));
35 }
36 
37 static ssize_t root_block_limit_show(struct btrfs_root *root, char *buf)
38 {
39 	return snprintf(buf, PAGE_SIZE, "%llu\n",
40 		(unsigned long long)btrfs_root_limit(&root->root_item));
41 }
42 
43 static ssize_t super_blocks_used_show(struct btrfs_fs_info *fs, char *buf)
44 {
45 
46 	return snprintf(buf, PAGE_SIZE, "%llu\n",
47 		(unsigned long long)btrfs_super_bytes_used(&fs->super_copy));
48 }
49 
50 static ssize_t super_total_blocks_show(struct btrfs_fs_info *fs, char *buf)
51 {
52 	return snprintf(buf, PAGE_SIZE, "%llu\n",
53 		(unsigned long long)btrfs_super_total_bytes(&fs->super_copy));
54 }
55 
56 static ssize_t super_blocksize_show(struct btrfs_fs_info *fs, char *buf)
57 {
58 	return snprintf(buf, PAGE_SIZE, "%llu\n",
59 		(unsigned long long)btrfs_super_sectorsize(&fs->super_copy));
60 }
61 
62 /* this is for root attrs (subvols/snapshots) */
63 struct btrfs_root_attr {
64 	struct attribute attr;
65 	ssize_t (*show)(struct btrfs_root *, char *);
66 	ssize_t (*store)(struct btrfs_root *, const char *, size_t);
67 };
68 
69 #define ROOT_ATTR(name, mode, show, store) \
70 static struct btrfs_root_attr btrfs_root_attr_##name = __ATTR(name, mode, \
71 							      show, store)
72 
73 ROOT_ATTR(blocks_used,	0444,	root_blocks_used_show,	NULL);
74 ROOT_ATTR(block_limit,	0644,	root_block_limit_show,	NULL);
75 
76 static struct attribute *btrfs_root_attrs[] = {
77 	&btrfs_root_attr_blocks_used.attr,
78 	&btrfs_root_attr_block_limit.attr,
79 	NULL,
80 };
81 
82 /* this is for super attrs (actual full fs) */
83 struct btrfs_super_attr {
84 	struct attribute attr;
85 	ssize_t (*show)(struct btrfs_fs_info *, char *);
86 	ssize_t (*store)(struct btrfs_fs_info *, const char *, size_t);
87 };
88 
89 #define SUPER_ATTR(name, mode, show, store) \
90 static struct btrfs_super_attr btrfs_super_attr_##name = __ATTR(name, mode, \
91 								show, store)
92 
93 SUPER_ATTR(blocks_used,		0444,	super_blocks_used_show,		NULL);
94 SUPER_ATTR(total_blocks,	0444,	super_total_blocks_show,	NULL);
95 SUPER_ATTR(blocksize,		0444,	super_blocksize_show,		NULL);
96 
97 static struct attribute *btrfs_super_attrs[] = {
98 	&btrfs_super_attr_blocks_used.attr,
99 	&btrfs_super_attr_total_blocks.attr,
100 	&btrfs_super_attr_blocksize.attr,
101 	NULL,
102 };
103 
104 static ssize_t btrfs_super_attr_show(struct kobject *kobj,
105 				    struct attribute *attr, char *buf)
106 {
107 	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
108 						super_kobj);
109 	struct btrfs_super_attr *a = container_of(attr,
110 						  struct btrfs_super_attr,
111 						  attr);
112 
113 	return a->show ? a->show(fs, buf) : 0;
114 }
115 
116 static ssize_t btrfs_super_attr_store(struct kobject *kobj,
117 				     struct attribute *attr,
118 				     const char *buf, size_t len)
119 {
120 	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
121 						super_kobj);
122 	struct btrfs_super_attr *a = container_of(attr,
123 						  struct btrfs_super_attr,
124 						  attr);
125 
126 	return a->store ? a->store(fs, buf, len) : 0;
127 }
128 
129 static ssize_t btrfs_root_attr_show(struct kobject *kobj,
130 				    struct attribute *attr, char *buf)
131 {
132 	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
133 						root_kobj);
134 	struct btrfs_root_attr *a = container_of(attr,
135 						 struct btrfs_root_attr,
136 						 attr);
137 
138 	return a->show ? a->show(root, buf) : 0;
139 }
140 
141 static ssize_t btrfs_root_attr_store(struct kobject *kobj,
142 				     struct attribute *attr,
143 				     const char *buf, size_t len)
144 {
145 	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
146 						root_kobj);
147 	struct btrfs_root_attr *a = container_of(attr,
148 						 struct btrfs_root_attr,
149 						 attr);
150 	return a->store ? a->store(root, buf, len) : 0;
151 }
152 
153 static void btrfs_super_release(struct kobject *kobj)
154 {
155 	struct btrfs_fs_info *fs = container_of(kobj, struct btrfs_fs_info,
156 						super_kobj);
157 	complete(&fs->kobj_unregister);
158 }
159 
160 static void btrfs_root_release(struct kobject *kobj)
161 {
162 	struct btrfs_root *root = container_of(kobj, struct btrfs_root,
163 						root_kobj);
164 	complete(&root->kobj_unregister);
165 }
166 
167 static const struct sysfs_ops btrfs_super_attr_ops = {
168 	.show	= btrfs_super_attr_show,
169 	.store	= btrfs_super_attr_store,
170 };
171 
172 static const struct sysfs_ops btrfs_root_attr_ops = {
173 	.show	= btrfs_root_attr_show,
174 	.store	= btrfs_root_attr_store,
175 };
176 
177 /* /sys/fs/btrfs/ entry */
178 static struct kset *btrfs_kset;
179 
180 int btrfs_init_sysfs(void)
181 {
182 	btrfs_kset = kset_create_and_add("btrfs", NULL, fs_kobj);
183 	if (!btrfs_kset)
184 		return -ENOMEM;
185 	return 0;
186 }
187 
188 void btrfs_exit_sysfs(void)
189 {
190 	kset_unregister(btrfs_kset);
191 }
192 
193