blob: 28bf359981fc678341af7e867d44dacfa2956647 [file] [log] [blame]
Linus Torvalds1da177e2005-04-16 15:20:36 -07001/*
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
Eric W. Biederman7d0c7d62007-08-20 21:36:30 +090017static struct vfsmount *sysfs_mount;
Linus Torvalds1da177e2005-04-16 15:20:36 -070018struct super_block * sysfs_sb = NULL;
Christoph Lametere18b8902006-12-06 20:33:20 -080019struct kmem_cache *sysfs_dir_cachep;
Linus Torvalds1da177e2005-04-16 15:20:36 -070020
Josef 'Jeff' Sipekee9b6d62007-02-12 00:55:41 -080021static const struct super_operations sysfs_ops = {
Linus Torvalds1da177e2005-04-16 15:20:36 -070022 .statfs = simple_statfs,
Eric W. Biederman90bc6132007-07-31 19:15:08 +090023 .drop_inode = generic_delete_inode,
Linus Torvalds1da177e2005-04-16 15:20:36 -070024};
25
Tejun Heo51225032007-06-14 04:27:25 +090026struct sysfs_dirent sysfs_root = {
Tejun Heo13b30862007-06-14 03:45:14 +090027 .s_count = ATOMIC_INIT(1),
Tejun Heob402d722007-06-14 04:27:21 +090028 .s_flags = SYSFS_ROOT,
Tejun Heofc9f54b2007-06-14 03:45:17 +090029 .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
Eric Sandeendc351252007-06-11 14:02:45 +090030 .s_ino = 1,
Linus Torvalds1da177e2005-04-16 15:20:36 -070031};
32
33static 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
Tejun Heoe080e432007-07-18 14:29:06 +090045 /* get root inode, initialize and unlock it */
46 inode = sysfs_get_inode(&sysfs_root);
Tejun Heofc9f54b2007-06-14 03:45:17 +090047 if (!inode) {
Linus Torvalds1da177e2005-04-16 15:20:36 -070048 pr_debug("sysfs: could not get root inode\n");
49 return -ENOMEM;
50 }
51
Tejun Heoe080e432007-07-18 14:29:06 +090052 /* instantiate and link root dentry */
Linus Torvalds1da177e2005-04-16 15:20:36 -070053 root = d_alloc_root(inode);
54 if (!root) {
55 pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
56 iput(inode);
57 return -ENOMEM;
58 }
59 root->d_fsdata = &sysfs_root;
60 sb->s_root = root;
61 return 0;
62}
63
David Howells454e2392006-06-23 02:02:57 -070064static int sysfs_get_sb(struct file_system_type *fs_type,
65 int flags, const char *dev_name, void *data, struct vfsmount *mnt)
Linus Torvalds1da177e2005-04-16 15:20:36 -070066{
David Howells454e2392006-06-23 02:02:57 -070067 return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
Linus Torvalds1da177e2005-04-16 15:20:36 -070068}
69
70static struct file_system_type sysfs_fs_type = {
71 .name = "sysfs",
72 .get_sb = sysfs_get_sb,
Eric W. Biederman0333cd82007-08-20 21:36:29 +090073 .kill_sb = kill_anon_super,
Linus Torvalds1da177e2005-04-16 15:20:36 -070074};
75
76int __init sysfs_init(void)
77{
78 int err = -ENOMEM;
79
80 sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
81 sizeof(struct sysfs_dirent),
Paul Mundt20c2df82007-07-20 10:11:58 +090082 0, 0, NULL);
Linus Torvalds1da177e2005-04-16 15:20:36 -070083 if (!sysfs_dir_cachep)
84 goto out;
85
86 err = register_filesystem(&sysfs_fs_type);
87 if (!err) {
88 sysfs_mount = kern_mount(&sysfs_fs_type);
89 if (IS_ERR(sysfs_mount)) {
90 printk(KERN_ERR "sysfs: could not mount!\n");
91 err = PTR_ERR(sysfs_mount);
92 sysfs_mount = NULL;
93 unregister_filesystem(&sysfs_fs_type);
94 goto out_err;
95 }
96 } else
97 goto out_err;
98out:
99 return err;
100out_err:
101 kmem_cache_destroy(sysfs_dir_cachep);
102 sysfs_dir_cachep = NULL;
103 goto out;
104}