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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> | |
94bebf4d | 11 | #include <asm/semaphore.h> |
1da177e4 LT |
12 | |
13 | #include "sysfs.h" | |
14 | ||
15 | /* Random magic number */ | |
16 | #define SYSFS_MAGIC 0x62656572 | |
17 | ||
18 | struct vfsmount *sysfs_mount; | |
19 | struct super_block * sysfs_sb = NULL; | |
e18b890b | 20 | struct kmem_cache *sysfs_dir_cachep; |
1da177e4 | 21 | |
94bebf4d ON |
22 | static void sysfs_clear_inode(struct inode *inode); |
23 | ||
ee9b6d61 | 24 | static const struct super_operations sysfs_ops = { |
1da177e4 | 25 | .statfs = simple_statfs, |
b592fcfe | 26 | .drop_inode = sysfs_delete_inode, |
94bebf4d | 27 | .clear_inode = sysfs_clear_inode, |
1da177e4 LT |
28 | }; |
29 | ||
30 | static struct sysfs_dirent sysfs_root = { | |
31 | .s_sibling = LIST_HEAD_INIT(sysfs_root.s_sibling), | |
32 | .s_children = LIST_HEAD_INIT(sysfs_root.s_children), | |
33 | .s_element = NULL, | |
34 | .s_type = SYSFS_ROOT, | |
8215534c | 35 | .s_iattr = NULL, |
1da177e4 LT |
36 | }; |
37 | ||
94bebf4d ON |
38 | static void sysfs_clear_inode(struct inode *inode) |
39 | { | |
40 | kfree(inode->i_private); | |
41 | } | |
42 | ||
1da177e4 LT |
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; | |
53 | sysfs_sb = sb; | |
54 | ||
8215534c MS |
55 | inode = sysfs_new_inode(S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
56 | &sysfs_root); | |
1da177e4 LT |
57 | if (inode) { |
58 | inode->i_op = &sysfs_dir_inode_operations; | |
59 | inode->i_fop = &sysfs_dir_operations; | |
60 | /* directory inodes start off with i_nlink == 2 (for "." entry) */ | |
d8c76e6f | 61 | inc_nlink(inode); |
1da177e4 LT |
62 | } else { |
63 | pr_debug("sysfs: could not get root inode\n"); | |
64 | return -ENOMEM; | |
65 | } | |
66 | ||
67 | root = d_alloc_root(inode); | |
68 | if (!root) { | |
69 | pr_debug("%s: could not get root dentry!\n",__FUNCTION__); | |
70 | iput(inode); | |
71 | return -ENOMEM; | |
72 | } | |
73 | root->d_fsdata = &sysfs_root; | |
74 | sb->s_root = root; | |
75 | return 0; | |
76 | } | |
77 | ||
454e2398 DH |
78 | static int sysfs_get_sb(struct file_system_type *fs_type, |
79 | int flags, const char *dev_name, void *data, struct vfsmount *mnt) | |
1da177e4 | 80 | { |
454e2398 | 81 | return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt); |
1da177e4 LT |
82 | } |
83 | ||
84 | static struct file_system_type sysfs_fs_type = { | |
85 | .name = "sysfs", | |
86 | .get_sb = sysfs_get_sb, | |
87 | .kill_sb = kill_litter_super, | |
88 | }; | |
89 | ||
90 | int __init sysfs_init(void) | |
91 | { | |
92 | int err = -ENOMEM; | |
93 | ||
94 | sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", | |
95 | sizeof(struct sysfs_dirent), | |
96 | 0, 0, NULL, NULL); | |
97 | if (!sysfs_dir_cachep) | |
98 | goto out; | |
99 | ||
100 | err = register_filesystem(&sysfs_fs_type); | |
101 | if (!err) { | |
102 | sysfs_mount = kern_mount(&sysfs_fs_type); | |
103 | if (IS_ERR(sysfs_mount)) { | |
104 | printk(KERN_ERR "sysfs: could not mount!\n"); | |
105 | err = PTR_ERR(sysfs_mount); | |
106 | sysfs_mount = NULL; | |
107 | unregister_filesystem(&sysfs_fs_type); | |
108 | goto out_err; | |
109 | } | |
110 | } else | |
111 | goto out_err; | |
112 | out: | |
113 | return err; | |
114 | out_err: | |
115 | kmem_cache_destroy(sysfs_dir_cachep); | |
116 | sysfs_dir_cachep = NULL; | |
117 | goto out; | |
118 | } |