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Commit | Line | Data |
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1da177e4 LT |
1 | /* |
2 | * mount.c - operations for initializing and mounting sysfs. | |
3 | */ | |
4 | ||
5 | #define DEBUG | |
6 | ||
7 | #include <linux/fs.h> | |
8 | #include <linux/mount.h> | |
9 | #include <linux/pagemap.h> | |
10 | #include <linux/init.h> | |
11 | ||
12 | #include "sysfs.h" | |
13 | ||
14 | /* Random magic number */ | |
15 | #define SYSFS_MAGIC 0x62656572 | |
16 | ||
17 | struct vfsmount *sysfs_mount; | |
18 | struct super_block * sysfs_sb = NULL; | |
19 | kmem_cache_t *sysfs_dir_cachep; | |
20 | ||
21 | static struct super_operations sysfs_ops = { | |
22 | .statfs = simple_statfs, | |
23 | .drop_inode = generic_delete_inode, | |
24 | }; | |
25 | ||
26 | static struct sysfs_dirent sysfs_root = { | |
27 | .s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling), | |
28 | .s_children = LIST_HEAD_INIT(sysfs_root.s_children), | |
29 | .s_element = NULL, | |
30 | .s_type = SYSFS_ROOT, | |
31 | }; | |
32 | ||
33 | static int sysfs_fill_super(struct super_block *sb, void *data, int silent) | |
34 | { | |
35 | struct inode *inode; | |
36 | struct dentry *root; | |
37 | ||
38 | sb->s_blocksize = PAGE_CACHE_SIZE; | |
39 | sb->s_blocksize_bits = PAGE_CACHE_SHIFT; | |
40 | sb->s_magic = SYSFS_MAGIC; | |
41 | sb->s_op = &sysfs_ops; | |
42 | sb->s_time_gran = 1; | |
43 | sysfs_sb = sb; | |
44 | ||
45 | inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO); | |
46 | if (inode) { | |
47 | inode->i_op = &sysfs_dir_inode_operations; | |
48 | inode->i_fop = &sysfs_dir_operations; | |
49 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
50 | inode->i_nlink++; | |
51 | } else { | |
52 | pr_debug("sysfs: could not get root inode\n"); | |
53 | return -ENOMEM; | |
54 | } | |
55 | ||
56 | root = d_alloc_root(inode); | |
57 | if (!root) { | |
58 | pr_debug("%s: could not get root dentry!\n",__FUNCTION__); | |
59 | iput(inode); | |
60 | return -ENOMEM; | |
61 | } | |
62 | root->d_fsdata = &sysfs_root; | |
63 | sb->s_root = root; | |
64 | return 0; | |
65 | } | |
66 | ||
67 | static struct super_block *sysfs_get_sb(struct file_system_type *fs_type, | |
68 | int flags, const char *dev_name, void *data) | |
69 | { | |
70 | return get_sb_single(fs_type, flags, data, sysfs_fill_super); | |
71 | } | |
72 | ||
73 | static struct file_system_type sysfs_fs_type = { | |
74 | .name = "sysfs", | |
75 | .get_sb = sysfs_get_sb, | |
76 | .kill_sb = kill_litter_super, | |
77 | }; | |
78 | ||
79 | int __init sysfs_init(void) | |
80 | { | |
81 | int err = -ENOMEM; | |
82 | ||
83 | sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", | |
84 | sizeof(struct sysfs_dirent), | |
85 | 0, 0, NULL, NULL); | |
86 | if (!sysfs_dir_cachep) | |
87 | goto out; | |
88 | ||
89 | err = register_filesystem(&sysfs_fs_type); | |
90 | if (!err) { | |
91 | sysfs_mount = kern_mount(&sysfs_fs_type); | |
92 | if (IS_ERR(sysfs_mount)) { | |
93 | printk(KERN_ERR "sysfs: could not mount!\n"); | |
94 | err = PTR_ERR(sysfs_mount); | |
95 | sysfs_mount = NULL; | |
96 | unregister_filesystem(&sysfs_fs_type); | |
97 | goto out_err; | |
98 | } | |
99 | } else | |
100 | goto out_err; | |
101 | out: | |
102 | return err; | |
103 | out_err: | |
104 | kmem_cache_destroy(sysfs_dir_cachep); | |
105 | sysfs_dir_cachep = NULL; | |
106 | goto out; | |
107 | } |