sysfs: reference sysfs_dirent from sysfs inodes

{

	struct bin_attribute *bin_attr;

	inode->i_private = sysfs_get(sd);

	inode->i_mapping->a_ops = &sysfs_aops;

	inode->i_mapping->backing_dev_info = &sysfs_backing_dev_info;

	inode->i_op = &sysfs_inode_operations;

	return inode;

}

/*

 * The sysfs_dirent serves as both an inode and a directory entry for sysfs.

 * To prevent the sysfs inode numbers from being freed prematurely we take a

 * reference to sysfs_dirent from the sysfs inode.  A

 * super_operations.delete_inode() implementation is needed to drop that

 * reference upon inode destruction.

 */

void sysfs_delete_inode(struct inode *inode)

{

	struct sysfs_dirent *sd  = inode->i_private;

	truncate_inode_pages(&inode->i_data, 0);

	clear_inode(inode);

	sysfs_put(sd);

}

int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name)

{

	struct sysfs_addrm_cxt acxt;

static const struct super_operations sysfs_ops = {

	.statfs		= simple_statfs,

	.drop_inode	= generic_delete_inode,

	.delete_inode	= sysfs_delete_inode,

};

struct sysfs_dirent sysfs_root = {

 * inode.c

 */

struct inode *sysfs_get_inode(struct sysfs_dirent *sd);

void sysfs_delete_inode(struct inode *inode);

int sysfs_setattr(struct dentry *dentry, struct iattr *iattr);

int sysfs_hash_and_remove(struct sysfs_dirent *dir_sd, const char *name);

int sysfs_inode_init(void);