Linux kernel mirror (for testing)
git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git
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kernel
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linux
1/*
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.
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>
19
20#include "sysfs.h"
21
22/* Random magic number */
23#define SYSFS_MAGIC 0x62656572
24
25static struct vfsmount *sysfs_mount;
26struct super_block * sysfs_sb = NULL;
27struct kmem_cache *sysfs_dir_cachep;
28
29static const struct super_operations sysfs_ops = {
30 .statfs = simple_statfs,
31 .drop_inode = generic_delete_inode,
32};
33
34struct sysfs_dirent sysfs_root = {
35 .s_name = "",
36 .s_count = ATOMIC_INIT(1),
37 .s_flags = SYSFS_DIR,
38 .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
39 .s_ino = 1,
40};
41
42static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
43{
44 struct inode *inode;
45 struct dentry *root;
46
47 sb->s_blocksize = PAGE_CACHE_SIZE;
48 sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
49 sb->s_magic = SYSFS_MAGIC;
50 sb->s_op = &sysfs_ops;
51 sb->s_time_gran = 1;
52 sysfs_sb = sb;
53
54 /* get root inode, initialize and unlock it */
55 inode = sysfs_get_inode(&sysfs_root);
56 if (!inode) {
57 pr_debug("sysfs: could not get root inode\n");
58 return -ENOMEM;
59 }
60
61 /* instantiate and link root dentry */
62 root = d_alloc_root(inode);
63 if (!root) {
64 pr_debug("%s: could not get root dentry!\n",__func__);
65 iput(inode);
66 return -ENOMEM;
67 }
68 root->d_fsdata = &sysfs_root;
69 sb->s_root = root;
70 return 0;
71}
72
73static int sysfs_get_sb(struct file_system_type *fs_type,
74 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
75{
76 return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
77}
78
79static struct file_system_type sysfs_fs_type = {
80 .name = "sysfs",
81 .get_sb = sysfs_get_sb,
82 .kill_sb = kill_anon_super,
83};
84
85int __init sysfs_init(void)
86{
87 int err = -ENOMEM;
88
89 sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
90 sizeof(struct sysfs_dirent),
91 0, 0, NULL);
92 if (!sysfs_dir_cachep)
93 goto out;
94
95 err = sysfs_inode_init();
96 if (err)
97 goto out_err;
98
99 err = register_filesystem(&sysfs_fs_type);
100 if (!err) {
101 sysfs_mount = kern_mount(&sysfs_fs_type);
102 if (IS_ERR(sysfs_mount)) {
103 printk(KERN_ERR "sysfs: could not mount!\n");
104 err = PTR_ERR(sysfs_mount);
105 sysfs_mount = NULL;
106 unregister_filesystem(&sysfs_fs_type);
107 goto out_err;
108 }
109 } else
110 goto out_err;
111out:
112 return err;
113out_err:
114 kmem_cache_destroy(sysfs_dir_cachep);
115 sysfs_dir_cachep = NULL;
116 goto out;
117}