blob: 39116af0390f7115a1bb7d70762931615f04cccf [file] [log] [blame]
// SPDX-License-Identifier: GPL-2.0-or-later
* 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 <>
* Michael C. Thompson <>
#include <linux/fs.h>
#include <linux/mount.h>
#include <linux/key.h>
#include <linux/slab.h>
#include <linux/seq_file.h>
#include <linux/file.h>
#include <linux/statfs.h>
#include <linux/magic.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 *inode_info;
struct inode *inode = NULL;
inode_info = kmem_cache_alloc(ecryptfs_inode_info_cache, GFP_KERNEL);
if (unlikely(!inode_info))
goto out;
if (ecryptfs_init_crypt_stat(&inode_info->crypt_stat)) {
kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
goto out;
atomic_set(&inode_info->lower_file_count, 0);
inode_info->lower_file = NULL;
inode = &inode_info->vfs_inode;
return inode;
static void ecryptfs_free_inode(struct inode *inode)
struct ecryptfs_inode_info *inode_info;
inode_info = ecryptfs_inode_to_private(inode);
kmem_cache_free(ecryptfs_inode_info_cache, inode_info);
* 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_statfs
* @dentry: The ecryptfs dentry
* @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)
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
int rc;
if (!lower_dentry->d_sb->s_op->statfs)
return -ENOSYS;
rc = lower_dentry->d_sb->s_op->statfs(lower_dentry, buf);
if (rc)
return rc;
rc = ecryptfs_set_f_namelen(&buf->f_namelen, buf->f_namelen,
return rc;
* ecryptfs_evict_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_evict_inode(struct inode *inode)
* ecryptfs_show_options
* Prints the mount options for a given superblock.
* Returns zero; does not fail.
static int ecryptfs_show_options(struct seq_file *m, struct dentry *root)
struct super_block *sb = root->d_sb;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat =
struct ecryptfs_global_auth_tok *walker;
mount_crypt_stat_list) {
if (walker->flags & ECRYPTFS_AUTH_TOK_FNEK)
seq_printf(m, ",ecryptfs_fnek_sig=%s", walker->sig);
seq_printf(m, ",ecryptfs_sig=%s", walker->sig);
seq_printf(m, ",ecryptfs_cipher=%s",
if (mount_crypt_stat->global_default_cipher_key_size)
seq_printf(m, ",ecryptfs_key_bytes=%zd",
seq_printf(m, ",ecryptfs_passthrough");
if (mount_crypt_stat->flags & ECRYPTFS_XATTR_METADATA_ENABLED)
seq_printf(m, ",ecryptfs_xattr_metadata");
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED)
seq_printf(m, ",ecryptfs_encrypted_view");
if (mount_crypt_stat->flags & ECRYPTFS_UNLINK_SIGS)
seq_printf(m, ",ecryptfs_unlink_sigs");
if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_MOUNT_AUTH_TOK_ONLY)
seq_printf(m, ",ecryptfs_mount_auth_tok_only");
return 0;
const struct super_operations ecryptfs_sops = {
.alloc_inode = ecryptfs_alloc_inode,
.destroy_inode = ecryptfs_destroy_inode,
.free_inode = ecryptfs_free_inode,
.statfs = ecryptfs_statfs,
.remount_fs = NULL,
.evict_inode = ecryptfs_evict_inode,
.show_options = ecryptfs_show_options