| /* |
| * mount.c - operations for initializing and mounting sysfs. |
| */ |
| |
| #define DEBUG |
| |
| #include <linux/fs.h> |
| #include <linux/mount.h> |
| #include <linux/pagemap.h> |
| #include <linux/init.h> |
| |
| #include "sysfs.h" |
| |
| /* Random magic number */ |
| #define SYSFS_MAGIC 0x62656572 |
| |
| static struct vfsmount *sysfs_mount; |
| struct super_block * sysfs_sb = NULL; |
| struct kmem_cache *sysfs_dir_cachep; |
| |
| static const struct super_operations sysfs_ops = { |
| .statfs = simple_statfs, |
| .drop_inode = generic_delete_inode, |
| }; |
| |
| struct sysfs_dirent sysfs_root = { |
| .s_count = ATOMIC_INIT(1), |
| .s_flags = SYSFS_ROOT, |
| .s_mode = S_IFDIR | S_IRWXU | S_IRUGO | S_IXUGO, |
| .s_ino = 1, |
| }; |
| |
| static int sysfs_fill_super(struct super_block *sb, void *data, int silent) |
| { |
| struct inode *inode; |
| struct dentry *root; |
| |
| sb->s_blocksize = PAGE_CACHE_SIZE; |
| sb->s_blocksize_bits = PAGE_CACHE_SHIFT; |
| sb->s_magic = SYSFS_MAGIC; |
| sb->s_op = &sysfs_ops; |
| sb->s_time_gran = 1; |
| sysfs_sb = sb; |
| |
| /* get root inode, initialize and unlock it */ |
| inode = sysfs_get_inode(&sysfs_root); |
| if (!inode) { |
| pr_debug("sysfs: could not get root inode\n"); |
| return -ENOMEM; |
| } |
| |
| /* instantiate and link root dentry */ |
| root = d_alloc_root(inode); |
| if (!root) { |
| pr_debug("%s: could not get root dentry!\n",__FUNCTION__); |
| iput(inode); |
| return -ENOMEM; |
| } |
| root->d_fsdata = &sysfs_root; |
| sb->s_root = root; |
| return 0; |
| } |
| |
| static int sysfs_get_sb(struct file_system_type *fs_type, |
| int flags, const char *dev_name, void *data, struct vfsmount *mnt) |
| { |
| return get_sb_single(fs_type, flags, data, sysfs_fill_super, mnt); |
| } |
| |
| static struct file_system_type sysfs_fs_type = { |
| .name = "sysfs", |
| .get_sb = sysfs_get_sb, |
| .kill_sb = kill_anon_super, |
| }; |
| |
| int __init sysfs_init(void) |
| { |
| int err = -ENOMEM; |
| |
| sysfs_dir_cachep = kmem_cache_create("sysfs_dir_cache", |
| sizeof(struct sysfs_dirent), |
| 0, 0, NULL); |
| if (!sysfs_dir_cachep) |
| goto out; |
| |
| err = register_filesystem(&sysfs_fs_type); |
| if (!err) { |
| sysfs_mount = kern_mount(&sysfs_fs_type); |
| if (IS_ERR(sysfs_mount)) { |
| printk(KERN_ERR "sysfs: could not mount!\n"); |
| err = PTR_ERR(sysfs_mount); |
| sysfs_mount = NULL; |
| unregister_filesystem(&sysfs_fs_type); |
| goto out_err; |
| } |
| } else |
| goto out_err; |
| out: |
| return err; |
| out_err: |
| kmem_cache_destroy(sysfs_dir_cachep); |
| sysfs_dir_cachep = NULL; |
| goto out; |
| } |