/** * eCryptfs: Linux filesystem encryption layer * * Copyright (C) 1997-2003 Erez Zadok * Copyright (C) 2001-2003 Stony Brook University * Copyright (C) 2004-2006 International Business Machines Corp. *   Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> *              Michael C. Thompson <mcthomps@us.ibm.com> * * This program is free software; you can redistribute it and/or * modify it under the terms of the GNU General Public License as * published by the Free Software Foundation; either version 2 of the * License, or (at your option) any later version. * * This program is distributed in the hope that it will be useful, but * WITHOUT ANY WARRANTY; without even the implied warranty of * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU * General Public License for more details. * * You should have received a copy of the GNU General Public License * along with this program; if not, write to the Free Software * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA * 02111-1307, USA. */ #include <linux/fs.h>#include <linux/mount.h>#include <linux/key.h>#include <linux/seq_file.h>#include <linux/crypto.h>#include "ecryptfs_kernel.h" struct kmem_cache *ecryptfs_inode_info_cache; /** * ecryptfs_alloc_inode - allocate an ecryptfs inode * @sb: Pointer to the ecryptfs super block * * Called to bring an inode into existence. * * Only handle allocation, setting up structures should be done in * ecryptfs_read_inode. This is because the kernel, between now and * then, will 0 out the private data pointer. * * Returns a pointer to a newly allocated inode, NULL otherwise */static struct inode *ecryptfs_alloc_inode(struct super_block *sb){	struct ecryptfs_inode_info *ecryptfs_inode;	struct inode *inode = NULL; 	ecryptfs_inode = kmem_cache_alloc(ecryptfs_inode_info_cache,					  GFP_KERNEL);	if (unlikely(!ecryptfs_inode))		goto out;	ecryptfs_init_crypt_stat(&ecryptfs_inode->crypt_stat);	inode = &ecryptfs_inode->vfs_inode;out:	return inode;} /** * ecryptfs_destroy_inode * @inode: The ecryptfs inode * * This is used during the final destruction of the inode. * All allocation of memory related to the inode, including allocated * memory in the crypt_stat struct, will be released here. * There should be no chance that this deallocation will be missed. */static void ecryptfs_destroy_inode(struct inode *inode){	struct ecryptfs_inode_info *inode_info; 	inode_info = ecryptfs_inode_to_private(inode);	ecryptfs_destruct_crypt_stat(&inode_info->crypt_stat);	kmem_cache_free(ecryptfs_inode_info_cache, inode_info);} /** * ecryptfs_init_inode * @inode: The ecryptfs inode * * Set up the ecryptfs inode. */void ecryptfs_init_inode(struct inode *inode, struct inode *lower_inode){	ecryptfs_set_inode_lower(inode, lower_inode);	inode->i_ino = lower_inode->i_ino;	inode->i_version++;	inode->i_op = &ecryptfs_main_iops;	inode->i_fop = &ecryptfs_main_fops;	inode->i_mapping->a_ops = &ecryptfs_aops;} /** * ecryptfs_put_super * @sb: Pointer to the ecryptfs super block * * Final actions when unmounting a file system. * This will handle deallocation and release of our private data. */static void ecryptfs_put_super(struct super_block *sb){	struct ecryptfs_sb_info *sb_info = ecryptfs_superblock_to_private(sb); 	ecryptfs_destruct_mount_crypt_stat(&sb_info->mount_crypt_stat);	kmem_cache_free(ecryptfs_sb_info_cache, sb_info);	ecryptfs_set_superblock_private(sb, NULL);} /** * ecryptfs_statfs * @sb: The ecryptfs super block * @buf: The struct kstatfs to fill in with stats * * Get the filesystem statistics. Currently, we let this pass right through * to the lower filesystem and take no action ourselves. */static int ecryptfs_statfs(struct dentry *dentry, struct kstatfs *buf){	return vfs_statfs(ecryptfs_dentry_to_lower(dentry), buf);} /** * ecryptfs_clear_inode * @inode - The ecryptfs inode * * Called by iput() when the inode reference count reached zero * and the inode is not hashed anywhere.  Used to clear anything * that needs to be, before the inode is completely destroyed and put * on the inode free list. We use this to drop out reference to the * lower inode. */static void ecryptfs_clear_inode(struct inode *inode){	iput(ecryptfs_inode_to_lower(inode));} /** * ecryptfs_show_options * * Prints the directory we are currently mounted over. * Returns zero on success; non-zero otherwise */static int ecryptfs_show_options(struct seq_file *m, struct vfsmount *mnt){	struct super_block *sb = mnt->mnt_sb;	struct dentry *lower_root_dentry = ecryptfs_dentry_to_lower(sb->s_root);	struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(sb->s_root);	char *tmp_page;	char *path;	int rc = 0; 	tmp_page = (char *)__get_free_page(GFP_KERNEL);	if (!tmp_page) {		rc = -ENOMEM;		goto out;	}	path = d_path(lower_root_dentry, lower_mnt, tmp_page, PAGE_SIZE);	if (IS_ERR(path)) {		rc = PTR_ERR(path);		goto out;	}	seq_printf(m, ",dir=%s", path);	free_page((unsigned long)tmp_page);out:	return rc;} const struct super_operations ecryptfs_sops = {	.alloc_inode = ecryptfs_alloc_inode,	.destroy_inode = ecryptfs_destroy_inode,	.drop_inode = generic_delete_inode,	.put_super = ecryptfs_put_super,	.statfs = ecryptfs_statfs,	.remount_fs = NULL,	.clear_inode = ecryptfs_clear_inode,	.show_options = ecryptfs_show_options};