mm: Remove slab destructors from kmem_cache_create().
[linux-2.6.git] / fs / sysfs / mount.c
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 #include <asm/semaphore.h>
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;
20 struct kmem_cache *sysfs_dir_cachep;
21
22 static const struct super_operations sysfs_ops = {
23         .statfs         = simple_statfs,
24         .drop_inode     = sysfs_delete_inode,
25 };
26
27 struct sysfs_dirent sysfs_root = {
28         .s_count        = ATOMIC_INIT(1),
29         .s_flags        = SYSFS_ROOT,
30         .s_mode         = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO,
31         .s_ino          = 1,
32 };
33
34 static int sysfs_fill_super(struct super_block *sb, void *data, int silent)
35 {
36         struct inode *inode;
37         struct dentry *root;
38
39         sb->s_blocksize = PAGE_CACHE_SIZE;
40         sb->s_blocksize_bits = PAGE_CACHE_SHIFT;
41         sb->s_magic = SYSFS_MAGIC;
42         sb->s_op = &sysfs_ops;
43         sb->s_time_gran = 1;
44         sysfs_sb = sb;
45
46         /* get root inode, initialize and unlock it */
47         inode = sysfs_get_inode(&sysfs_root);
48         if (!inode) {
49                 pr_debug("sysfs: could not get root inode\n");
50                 return -ENOMEM;
51         }
52
53         inode->i_op = &sysfs_dir_inode_operations;
54         inode->i_fop = &sysfs_dir_operations;
55         inc_nlink(inode); /* directory, account for "." */
56         unlock_new_inode(inode);
57
58         /* instantiate and link root dentry */
59         root = d_alloc_root(inode);
60         if (!root) {
61                 pr_debug("%s: could not get root dentry!\n",__FUNCTION__);
62                 iput(inode);
63                 return -ENOMEM;
64         }
65         sysfs_root.s_dentry = root;
66         root->d_fsdata = &sysfs_root;
67         sb->s_root = root;
68         return 0;
69 }
70
71 static int sysfs_get_sb(struct file_system_type *fs_type,
72         int flags, const char *dev_name, void *data, struct vfsmount *mnt)
73 {
74         return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt);
75 }
76
77 static struct file_system_type sysfs_fs_type = {
78         .name           = "sysfs",
79         .get_sb         = sysfs_get_sb,
80         .kill_sb        = kill_litter_super,
81 };
82
83 int __init sysfs_init(void)
84 {
85         int err = -ENOMEM;
86
87         sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache",
88                                               sizeof(struct sysfs_dirent),
89                                               0, 0, NULL);
90         if (!sysfs_dir_cachep)
91                 goto out;
92
93         err = register_filesystem(&sysfs_fs_type);
94         if (!err) {
95                 sysfs_mount = kern_mount(&sysfs_fs_type);
96                 if (IS_ERR(sysfs_mount)) {
97                         printk(KERN_ERR "sysfs: could not mount!\n");
98                         err = PTR_ERR(sysfs_mount);
99                         sysfs_mount = NULL;
100                         unregister_filesystem(&sysfs_fs_type);
101                         goto out_err;
102                 }
103         } else
104                 goto out_err;
105 out:
106         return err;
107 out_err:
108         kmem_cache_destroy(sysfs_dir_cachep);
109         sysfs_dir_cachep = NULL;
110         goto out;
111 }