| Linus Torvalds | 1da177e | 2005-04-16 15:20:36 -0700 | [diff] [blame] | 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 | } |