Commit | Line | Data |
---|---|---|
1da177e4 | 1 | /* |
6d66f5cd TH |
2 | * fs/sysfs/symlink.c - operations for initializing and mounting sysfs |
3 | * | |
4 | * Copyright (c) 2001-3 Patrick Mochel | |
5 | * Copyright (c) 2007 SUSE Linux Products GmbH | |
6 | * Copyright (c) 2007 Tejun Heo <teheo@suse.de> | |
7 | * | |
8 | * This file is released under the GPLv2. | |
9 | * | |
10 | * Please see Documentation/filesystems/sysfs.txt for more information. | |
1da177e4 LT |
11 | */ |
12 | ||
13 | #define DEBUG | |
14 | ||
15 | #include <linux/fs.h> | |
16 | #include <linux/mount.h> | |
17 | #include <linux/pagemap.h> | |
18 | #include <linux/init.h> | |
f1282c84 | 19 | #include <linux/module.h> |
8231f2f9 | 20 | #include <linux/magic.h> |
5a0e3ad6 | 21 | #include <linux/slab.h> |
1da177e4 LT |
22 | |
23 | #include "sysfs.h" | |
24 | ||
1da177e4 | 25 | |
7d0c7d67 | 26 | static struct vfsmount *sysfs_mount; |
e18b890b | 27 | struct kmem_cache *sysfs_dir_cachep; |
1da177e4 | 28 | |
ee9b6d61 | 29 | static const struct super_operations sysfs_ops = { |
1da177e4 | 30 | .statfs = simple_statfs, |
90bc6135 | 31 | .drop_inode = generic_delete_inode, |
04256b4a | 32 | .delete_inode = sysfs_delete_inode, |
1da177e4 LT |
33 | }; |
34 | ||
51225039 | 35 | struct sysfs_dirent sysfs_root = { |
dc2f75f0 | 36 | .s_name = "", |
13b3086d | 37 | .s_count = ATOMIC_INIT(1), |
3ff195b0 | 38 | .s_flags = SYSFS_DIR | (KOBJ_NS_TYPE_NONE << SYSFS_NS_TYPE_SHIFT), |
fc9f54b9 | 39 | .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
dc351252 | 40 | .s_ino = 1, |
1da177e4 LT |
41 | }; |
42 | ||
43 | static int sysfs_fill_super(struct super_block *sb, void *data, int silent) | |
44 | { | |
45 | struct inode *inode; | |
46 | struct dentry *root; | |
47 | ||
48 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
49 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
50 | sb->s_magic = SYSFS_MAGIC; | |
51 | sb->s_op = &sysfs_ops; | |
52 | sb->s_time_gran = 1; | |
1da177e4 | 53 | |
e080e436 | 54 | /* get root inode, initialize and unlock it */ |
4a67a1bc | 55 | mutex_lock(&sysfs_mutex); |
fac2622b | 56 | inode = sysfs_get_inode(sb, &sysfs_root); |
4a67a1bc | 57 | mutex_unlock(&sysfs_mutex); |
fc9f54b9 | 58 | if (!inode) { |
1da177e4 LT |
59 | pr_debug("sysfs: could not get root inode\n"); |
60 | return -ENOMEM; | |
61 | } | |
62 | ||
e080e436 | 63 | /* instantiate and link root dentry */ |
1da177e4 LT |
64 | root = d_alloc_root(inode); |
65 | if (!root) { | |
8e24eea7 | 66 | pr_debug("%s: could not get root dentry!\n",__func__); |
1da177e4 LT |
67 | iput(inode); |
68 | return -ENOMEM; | |
69 | } | |
70 | root->d_fsdata = &sysfs_root; | |
71 | sb->s_root = root; | |
72 | return 0; | |
73 | } | |
74 | ||
9e7fdd25 EB |
75 | static int sysfs_test_super(struct super_block *sb, void *data) |
76 | { | |
77 | struct sysfs_super_info *sb_info = sysfs_info(sb); | |
78 | struct sysfs_super_info *info = data; | |
3ff195b0 | 79 | enum kobj_ns_type type; |
9e7fdd25 | 80 | int found = 1; |
3ff195b0 EB |
81 | |
82 | for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) { | |
83 | if (sb_info->ns[type] != info->ns[type]) | |
84 | found = 0; | |
85 | } | |
9e7fdd25 EB |
86 | return found; |
87 | } | |
88 | ||
89 | static int sysfs_set_super(struct super_block *sb, void *data) | |
90 | { | |
91 | int error; | |
92 | error = set_anon_super(sb, data); | |
93 | if (!error) | |
94 | sb->s_fs_info = data; | |
95 | return error; | |
96 | } | |
97 | ||
454e2398 DH |
98 | static int sysfs_get_sb(struct file_system_type *fs_type, |
99 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 100 | { |
9e7fdd25 | 101 | struct sysfs_super_info *info; |
3ff195b0 | 102 | enum kobj_ns_type type; |
9e7fdd25 EB |
103 | struct super_block *sb; |
104 | int error; | |
105 | ||
106 | error = -ENOMEM; | |
107 | info = kzalloc(sizeof(*info), GFP_KERNEL); | |
108 | if (!info) | |
109 | goto out; | |
3ff195b0 EB |
110 | |
111 | for (type = KOBJ_NS_TYPE_NONE; type < KOBJ_NS_TYPES; type++) | |
112 | info->ns[type] = kobj_ns_current(type); | |
113 | ||
9e7fdd25 EB |
114 | sb = sget(fs_type, sysfs_test_super, sysfs_set_super, info); |
115 | if (IS_ERR(sb) || sb->s_fs_info != info) | |
116 | kfree(info); | |
117 | if (IS_ERR(sb)) { | |
9e7fdd25 EB |
118 | error = PTR_ERR(sb); |
119 | goto out; | |
120 | } | |
121 | if (!sb->s_root) { | |
122 | sb->s_flags = flags; | |
123 | error = sysfs_fill_super(sb, data, flags & MS_SILENT ? 1 : 0); | |
124 | if (error) { | |
125 | deactivate_locked_super(sb); | |
126 | goto out; | |
127 | } | |
128 | sb->s_flags |= MS_ACTIVE; | |
129 | } | |
130 | ||
131 | simple_set_mnt(mnt, sb); | |
132 | error = 0; | |
133 | out: | |
134 | return error; | |
135 | } | |
136 | ||
137 | static void sysfs_kill_sb(struct super_block *sb) | |
138 | { | |
139 | struct sysfs_super_info *info = sysfs_info(sb); | |
140 | ||
68d75ed4 EB |
141 | /* Remove the superblock from fs_supers/s_instances |
142 | * so we can't find it, before freeing sysfs_super_info. | |
143 | */ | |
9e7fdd25 EB |
144 | kill_anon_super(sb); |
145 | kfree(info); | |
1da177e4 LT |
146 | } |
147 | ||
148 | static struct file_system_type sysfs_fs_type = { | |
149 | .name = "sysfs", | |
150 | .get_sb = sysfs_get_sb, | |
9e7fdd25 | 151 | .kill_sb = sysfs_kill_sb, |
1da177e4 LT |
152 | }; |
153 | ||
3ff195b0 EB |
154 | void sysfs_exit_ns(enum kobj_ns_type type, const void *ns) |
155 | { | |
156 | struct super_block *sb; | |
157 | ||
158 | mutex_lock(&sysfs_mutex); | |
159 | spin_lock(&sb_lock); | |
160 | list_for_each_entry(sb, &sysfs_fs_type.fs_supers, s_instances) { | |
161 | struct sysfs_super_info *info = sysfs_info(sb); | |
68d75ed4 EB |
162 | /* |
163 | * If we see a superblock on the fs_supers/s_instances | |
164 | * list the unmount has not completed and sb->s_fs_info | |
165 | * points to a valid struct sysfs_super_info. | |
166 | */ | |
3ff195b0 EB |
167 | /* Ignore superblocks with the wrong ns */ |
168 | if (info->ns[type] != ns) | |
169 | continue; | |
170 | info->ns[type] = NULL; | |
171 | } | |
172 | spin_unlock(&sb_lock); | |
173 | mutex_unlock(&sysfs_mutex); | |
174 | } | |
175 | ||
1da177e4 LT |
176 | int __init sysfs_init(void) |
177 | { | |
178 | int err = -ENOMEM; | |
179 | ||
180 | sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", | |
181 | sizeof(struct sysfs_dirent), | |
20c2df83 | 182 | 0, 0, NULL); |
1da177e4 LT |
183 | if (!sysfs_dir_cachep) |
184 | goto out; | |
185 | ||
e0bf68dd PZ |
186 | err = sysfs_inode_init(); |
187 | if (err) | |
188 | goto out_err; | |
189 | ||
1da177e4 LT |
190 | err = register_filesystem(&sysfs_fs_type); |
191 | if (!err) { | |
192 | sysfs_mount = kern_mount(&sysfs_fs_type); | |
193 | if (IS_ERR(sysfs_mount)) { | |
194 | printk(KERN_ERR "sysfs: could not mount!\n"); | |
195 | err = PTR_ERR(sysfs_mount); | |
196 | sysfs_mount = NULL; | |
197 | unregister_filesystem(&sysfs_fs_type); | |
198 | goto out_err; | |
199 | } | |
200 | } else | |
201 | goto out_err; | |
202 | out: | |
203 | return err; | |
204 | out_err: | |
205 | kmem_cache_destroy(sysfs_dir_cachep); | |
206 | sysfs_dir_cachep = NULL; | |
207 | goto out; | |
208 | } | |
f1282c84 NB |
209 | |
210 | #undef sysfs_get | |
211 | struct sysfs_dirent *sysfs_get(struct sysfs_dirent *sd) | |
212 | { | |
213 | return __sysfs_get(sd); | |
214 | } | |
215 | EXPORT_SYMBOL_GPL(sysfs_get); | |
216 | ||
217 | #undef sysfs_put | |
218 | void sysfs_put(struct sysfs_dirent *sd) | |
219 | { | |
220 | __sysfs_put(sd); | |
221 | } | |
222 | EXPORT_SYMBOL_GPL(sysfs_put); |