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linux/fs/ecryptfs/inode.c
Tejun Heo 5a0e3ad6af include cleanup: Update gfp.h and slab.h includes to prepare for breaking implicit slab.h inclusion from percpu.h 
percpu.h is included by sched.h and module.h and thus ends up being
included when building most .c files.  percpu.h includes slab.h which
in turn includes gfp.h making everything defined by the two files
universally available and complicating inclusion dependencies.

percpu.h -> slab.h dependency is about to be removed.  Prepare for
this change by updating users of gfp and slab facilities include those
headers directly instead of assuming availability.  As this conversion
needs to touch large number of source files, the following script is
used as the basis of conversion.

  http://userweb.kernel.org/~tj/misc/slabh-sweep.py

The script does the followings.

* Scan files for gfp and slab usages and update includes such that
  only the necessary includes are there.  ie. if only gfp is used,
  gfp.h, if slab is used, slab.h.

* When the script inserts a new include, it looks at the include
  blocks and try to put the new include such that its order conforms
  to its surrounding.  It's put in the include block which contains
  core kernel includes, in the same order that the rest are ordered -
  alphabetical, Christmas tree, rev-Xmas-tree or at the end if there
  doesn't seem to be any matching order.

* If the script can't find a place to put a new include (mostly
  because the file doesn't have fitting include block), it prints out
  an error message indicating which .h file needs to be added to the
  file.

The conversion was done in the following steps.

1. The initial automatic conversion of all .c files updated slightly
   over 4000 files, deleting around 700 includes and adding ~480 gfp.h
   and ~3000 slab.h inclusions.  The script emitted errors for ~400
   files.

2. Each error was manually checked.  Some didn't need the inclusion,
   some needed manual addition while adding it to implementation .h or
   embedding .c file was more appropriate for others.  This step added
   inclusions to around 150 files.

3. The script was run again and the output was compared to the edits
   from #2 to make sure no file was left behind.

4. Several build tests were done and a couple of problems were fixed.
   e.g. lib/decompress_*.c used malloc/free() wrappers around slab
   APIs requiring slab.h to be added manually.

5. The script was run on all .h files but without automatically
   editing them as sprinkling gfp.h and slab.h inclusions around .h
   files could easily lead to inclusion dependency hell.  Most gfp.h
   inclusion directives were ignored as stuff from gfp.h was usually
   wildly available and often used in preprocessor macros.  Each
   slab.h inclusion directive was examined and added manually as
   necessary.

6. percpu.h was updated not to include slab.h.

7. Build test were done on the following configurations and failures
   were fixed.  CONFIG_GCOV_KERNEL was turned off for all tests (as my
   distributed build env didn't work with gcov compiles) and a few
   more options had to be turned off depending on archs to make things
   build (like ipr on powerpc/64 which failed due to missing writeq).

   * x86 and x86_64 UP and SMP allmodconfig and a custom test config.
   * powerpc and powerpc64 SMP allmodconfig
   * sparc and sparc64 SMP allmodconfig
   * ia64 SMP allmodconfig
   * s390 SMP allmodconfig
   * alpha SMP allmodconfig
   * um on x86_64 SMP allmodconfig

8. percpu.h modifications were reverted so that it could be applied as
   a separate patch and serve as bisection point.

Given the fact that I had only a couple of failures from tests on step
6, I'm fairly confident about the coverage of this conversion patch.
If there is a breakage, it's likely to be something in one of the arch
headers which should be easily discoverable easily on most builds of
the specific arch.

Signed-off-by: Tejun Heo <tj@kernel.org>
Guess-its-ok-by: Christoph Lameter <cl@linux-foundation.org>
Cc: Ingo Molnar <mingo@redhat.com>
Cc: Lee Schermerhorn <Lee.Schermerhorn@hp.com>
2010-03-30 22:02:32 +09:00

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/**
* eCryptfs: Linux filesystem encryption layer
*
* Copyright (C) 1997-2004 Erez Zadok
* Copyright (C) 2001-2004 Stony Brook University
* Copyright (C) 2004-2007 International Business Machines Corp.
* Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
* Michael C. Thompsion <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/file.h>
#include <linux/vmalloc.h>
#include <linux/pagemap.h>
#include <linux/dcache.h>
#include <linux/namei.h>
#include <linux/mount.h>
#include <linux/crypto.h>
#include <linux/fs_stack.h>
#include <linux/slab.h>
#include <asm/unaligned.h>
#include "ecryptfs_kernel.h"
static struct dentry *lock_parent(struct dentry *dentry)
{
struct dentry *dir;
dir = dget_parent(dentry);
mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
return dir;
}
static void unlock_dir(struct dentry *dir)
{
mutex_unlock(&dir->d_inode->i_mutex);
dput(dir);
}
/**
* ecryptfs_create_underlying_file
* @lower_dir_inode: inode of the parent in the lower fs of the new file
* @dentry: New file's dentry
* @mode: The mode of the new file
* @nd: nameidata of ecryptfs' parent's dentry & vfsmount
*
* Creates the file in the lower file system.
*
* Returns zero on success; non-zero on error condition
*/
static int
ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
struct dentry *dentry, int mode,
struct nameidata *nd)
{
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
struct dentry *dentry_save;
struct vfsmount *vfsmount_save;
int rc;
dentry_save = nd->path.dentry;
vfsmount_save = nd->path.mnt;
nd->path.dentry = lower_dentry;
nd->path.mnt = lower_mnt;
rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
nd->path.dentry = dentry_save;
nd->path.mnt = vfsmount_save;
return rc;
}
/**
* ecryptfs_do_create
* @directory_inode: inode of the new file's dentry's parent in ecryptfs
* @ecryptfs_dentry: New file's dentry in ecryptfs
* @mode: The mode of the new file
* @nd: nameidata of ecryptfs' parent's dentry & vfsmount
*
* Creates the underlying file and the eCryptfs inode which will link to
* it. It will also update the eCryptfs directory inode to mimic the
* stat of the lower directory inode.
*
* Returns zero on success; non-zero on error condition
*/
static int
ecryptfs_do_create(struct inode *directory_inode,
struct dentry *ecryptfs_dentry, int mode,
struct nameidata *nd)
{
int rc;
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
if (IS_ERR(lower_dir_dentry)) {
ecryptfs_printk(KERN_ERR, "Error locking directory of "
"dentry\n");
rc = PTR_ERR(lower_dir_dentry);
goto out;
}
rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
ecryptfs_dentry, mode, nd);
if (rc) {
printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
"rc = [%d]\n", __func__, rc);
goto out_lock;
}
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
directory_inode->i_sb, 0);
if (rc) {
ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
goto out_lock;
}
fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
out_lock:
unlock_dir(lower_dir_dentry);
out:
return rc;
}
/**
* grow_file
* @ecryptfs_dentry: the eCryptfs dentry
*
* This is the code which will grow the file to its correct size.
*/
static int grow_file(struct dentry *ecryptfs_dentry)
{
struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
struct file fake_file;
struct ecryptfs_file_info tmp_file_info;
char zero_virt[] = { 0x00 };
int rc = 0;
memset(&fake_file, 0, sizeof(fake_file));
fake_file.f_path.dentry = ecryptfs_dentry;
memset(&tmp_file_info, 0, sizeof(tmp_file_info));
ecryptfs_set_file_private(&fake_file, &tmp_file_info);
ecryptfs_set_file_lower(
&fake_file,
ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
i_size_write(ecryptfs_inode, 0);
rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
ECRYPTFS_NEW_FILE;
return rc;
}
/**
* ecryptfs_initialize_file
*
* Cause the file to be changed from a basic empty file to an ecryptfs
* file with a header and first data page.
*
* Returns zero on success
*/
static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
{
struct ecryptfs_crypt_stat *crypt_stat =
&ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
int rc = 0;
if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
goto out;
}
crypt_stat->flags |= ECRYPTFS_NEW_FILE;
ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
rc = ecryptfs_new_file_context(ecryptfs_dentry);
if (rc) {
ecryptfs_printk(KERN_ERR, "Error creating new file "
"context; rc = [%d]\n", rc);
goto out;
}
if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out;
}
}
rc = ecryptfs_write_metadata(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
goto out;
}
rc = grow_file(ecryptfs_dentry);
if (rc)
printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
out:
return rc;
}
/**
* ecryptfs_create
* @dir: The inode of the directory in which to create the file.
* @dentry: The eCryptfs dentry
* @mode: The mode of the new file.
* @nd: nameidata
*
* Creates a new file.
*
* Returns zero on success; non-zero on error condition
*/
static int
ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
int mode, struct nameidata *nd)
{
int rc;
/* ecryptfs_do_create() calls ecryptfs_interpose() */
rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
if (unlikely(rc)) {
ecryptfs_printk(KERN_WARNING, "Failed to create file in"
"lower filesystem\n");
goto out;
}
/* At this point, a file exists on "disk"; we need to make sure
* that this on disk file is prepared to be an ecryptfs file */
rc = ecryptfs_initialize_file(ecryptfs_dentry);
out:
return rc;
}
/**
* ecryptfs_lookup_and_interpose_lower - Perform a lookup
*/
int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
struct dentry *lower_dentry,
struct inode *ecryptfs_dir_inode,
struct nameidata *ecryptfs_nd)
{
struct dentry *lower_dir_dentry;
struct vfsmount *lower_mnt;
struct inode *lower_inode;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
struct ecryptfs_crypt_stat *crypt_stat;
char *page_virt = NULL;
u64 file_size;
int rc = 0;
lower_dir_dentry = lower_dentry->d_parent;
lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
ecryptfs_dentry->d_parent));
lower_inode = lower_dentry->d_inode;
fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
BUG_ON(!atomic_read(&lower_dentry->d_count));
ecryptfs_set_dentry_private(ecryptfs_dentry,
kmem_cache_alloc(ecryptfs_dentry_info_cache,
GFP_KERNEL));
if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
rc = -ENOMEM;
printk(KERN_ERR "%s: Out of memory whilst attempting "
"to allocate ecryptfs_dentry_info struct\n",
__func__);
goto out_dput;
}
ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
if (!lower_dentry->d_inode) {
/* We want to add because we couldn't find in lower */
d_add(ecryptfs_dentry, NULL);
goto out;
}
rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
ecryptfs_dir_inode->i_sb,
ECRYPTFS_INTERPOSE_FLAG_D_ADD);
if (rc) {
printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
__func__, rc);
goto out;
}
if (S_ISDIR(lower_inode->i_mode))
goto out;
if (S_ISLNK(lower_inode->i_mode))
goto out;
if (special_file(lower_inode->i_mode))
goto out;
if (!ecryptfs_nd)
goto out;
/* Released in this function */
page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
if (!page_virt) {
printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
__func__);
rc = -ENOMEM;
goto out;
}
if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
if (rc) {
printk(KERN_ERR "%s: Error attempting to initialize "
"the persistent file for the dentry with name "
"[%s]; rc = [%d]\n", __func__,
ecryptfs_dentry->d_name.name, rc);
goto out_free_kmem;
}
}
crypt_stat = &ecryptfs_inode_to_private(
ecryptfs_dentry->d_inode)->crypt_stat;
/* TODO: lock for crypt_stat comparison */
if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
ecryptfs_set_default_sizes(crypt_stat);
rc = ecryptfs_read_and_validate_header_region(page_virt,
ecryptfs_dentry->d_inode);
if (rc) {
rc = ecryptfs_read_and_validate_xattr_region(page_virt,
ecryptfs_dentry);
if (rc) {
rc = 0;
goto out_free_kmem;
}
crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
file_size = (crypt_stat->num_header_bytes_at_front
+ i_size_read(lower_dentry->d_inode));
else
file_size = i_size_read(lower_dentry->d_inode);
} else {
file_size = get_unaligned_be64(page_virt);
}
i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
out_free_kmem:
kmem_cache_free(ecryptfs_header_cache_2, page_virt);
goto out;
out_dput:
dput(lower_dentry);
d_drop(ecryptfs_dentry);
out:
return rc;
}
/**
* ecryptfs_lookup
* @ecryptfs_dir_inode: The eCryptfs directory inode
* @ecryptfs_dentry: The eCryptfs dentry that we are looking up
* @ecryptfs_nd: nameidata; may be NULL
*
* Find a file on disk. If the file does not exist, then we'll add it to the
* dentry cache and continue on to read it from the disk.
*/
static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
struct dentry *ecryptfs_dentry,
struct nameidata *ecryptfs_nd)
{
char *encrypted_and_encoded_name = NULL;
size_t encrypted_and_encoded_name_size;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
struct dentry *lower_dir_dentry, *lower_dentry;
int rc = 0;
ecryptfs_dentry->d_op = &ecryptfs_dops;
if ((ecryptfs_dentry->d_name.len == 1
&& !strcmp(ecryptfs_dentry->d_name.name, "."))
|| (ecryptfs_dentry->d_name.len == 2
&& !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
goto out_d_drop;
}
lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
lower_dir_dentry,
ecryptfs_dentry->d_name.len);
mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
if (IS_ERR(lower_dentry)) {
rc = PTR_ERR(lower_dentry);
printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
"lower_dentry = [%s]\n", __func__, rc,
ecryptfs_dentry->d_name.name);
goto out_d_drop;
}
if (lower_dentry->d_inode)
goto lookup_and_interpose;
mount_crypt_stat = &ecryptfs_superblock_to_private(
ecryptfs_dentry->d_sb)->mount_crypt_stat;
if (!(mount_crypt_stat
&& (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
goto lookup_and_interpose;
dput(lower_dentry);
rc = ecryptfs_encrypt_and_encode_filename(
&encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
ecryptfs_dentry->d_name.len);
if (rc) {
printk(KERN_ERR "%s: Error attempting to encrypt and encode "
"filename; rc = [%d]\n", __func__, rc);
goto out_d_drop;
}
mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
lower_dentry = lookup_one_len(encrypted_and_encoded_name,
lower_dir_dentry,
encrypted_and_encoded_name_size - 1);
mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
if (IS_ERR(lower_dentry)) {
rc = PTR_ERR(lower_dentry);
printk(KERN_ERR "%s: lookup_one_len() returned [%d] on "
"lower_dentry = [%s]\n", __func__, rc,
encrypted_and_encoded_name);
goto out_d_drop;
}
lookup_and_interpose:
rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
ecryptfs_dir_inode,
ecryptfs_nd);
goto out;
out_d_drop:
d_drop(ecryptfs_dentry);
out:
kfree(encrypted_and_encoded_name);
return ERR_PTR(rc);
}
static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
struct dentry *new_dentry)
{
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_dir_dentry;
u64 file_size_save;
int rc;
file_size_save = i_size_read(old_dentry->d_inode);
lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
dget(lower_old_dentry);
dget(lower_new_dentry);
lower_dir_dentry = lock_parent(lower_new_dentry);
rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
lower_new_dentry);
if (rc || !lower_new_dentry->d_inode)
goto out_lock;
rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
if (rc)
goto out_lock;
fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
old_dentry->d_inode->i_nlink =
ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
i_size_write(new_dentry->d_inode, file_size_save);
out_lock:
unlock_dir(lower_dir_dentry);
dput(lower_new_dentry);
dput(lower_old_dentry);
return rc;
}
static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
{
int rc = 0;
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
struct dentry *lower_dir_dentry;
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
rc = vfs_unlink(lower_dir_inode, lower_dentry);
if (rc) {
printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
goto out_unlock;
}
fsstack_copy_attr_times(dir, lower_dir_inode);
dentry->d_inode->i_nlink =
ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
dentry->d_inode->i_ctime = dir->i_ctime;
d_drop(dentry);
out_unlock:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
return rc;
}
static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
const char *symname)
{
int rc;
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
char *encoded_symname;
size_t encoded_symlen;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
dget(lower_dentry);
lower_dir_dentry = lock_parent(lower_dentry);
mount_crypt_stat = &ecryptfs_superblock_to_private(
dir->i_sb)->mount_crypt_stat;
rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
&encoded_symlen,
NULL,
mount_crypt_stat, symname,
strlen(symname));
if (rc)
goto out_lock;
rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
encoded_symname);
kfree(encoded_symname);
if (rc || !lower_dentry->d_inode)
goto out_lock;
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
if (rc)
goto out_lock;
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
out_lock:
unlock_dir(lower_dir_dentry);
dput(lower_dentry);
if (!dentry->d_inode)
d_drop(dentry);
return rc;
}
static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
{
int rc;
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
lower_dir_dentry = lock_parent(lower_dentry);
rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
if (rc || !lower_dentry->d_inode)
goto out;
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
if (rc)
goto out;
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
out:
unlock_dir(lower_dir_dentry);
if (!dentry->d_inode)
d_drop(dentry);
return rc;
}
static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
{
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
int rc;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
dget(dentry);
lower_dir_dentry = lock_parent(lower_dentry);
dget(lower_dentry);
rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
dput(lower_dentry);
if (!rc)
d_delete(lower_dentry);
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
unlock_dir(lower_dir_dentry);
if (!rc)
d_drop(dentry);
dput(dentry);
return rc;
}
static int
ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
{
int rc;
struct dentry *lower_dentry;
struct dentry *lower_dir_dentry;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
lower_dir_dentry = lock_parent(lower_dentry);
rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
if (rc || !lower_dentry->d_inode)
goto out;
rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
if (rc)
goto out;
fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
out:
unlock_dir(lower_dir_dentry);
if (!dentry->d_inode)
d_drop(dentry);
return rc;
}
static int
ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
struct inode *new_dir, struct dentry *new_dentry)
{
int rc;
struct dentry *lower_old_dentry;
struct dentry *lower_new_dentry;
struct dentry *lower_old_dir_dentry;
struct dentry *lower_new_dir_dentry;
struct dentry *trap = NULL;
lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
dget(lower_old_dentry);
dget(lower_new_dentry);
lower_old_dir_dentry = dget_parent(lower_old_dentry);
lower_new_dir_dentry = dget_parent(lower_new_dentry);
trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
/* source should not be ancestor of target */
if (trap == lower_old_dentry) {
rc = -EINVAL;
goto out_lock;
}
/* target should not be ancestor of source */
if (trap == lower_new_dentry) {
rc = -ENOTEMPTY;
goto out_lock;
}
rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
lower_new_dir_dentry->d_inode, lower_new_dentry);
if (rc)
goto out_lock;
fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
if (new_dir != old_dir)
fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
out_lock:
unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
dput(lower_new_dentry->d_parent);
dput(lower_old_dentry->d_parent);
dput(lower_new_dentry);
dput(lower_old_dentry);
return rc;
}
static int
ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
{
char *lower_buf;
size_t lower_bufsiz;
struct dentry *lower_dentry;
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
char *plaintext_name;
size_t plaintext_name_size;
mm_segment_t old_fs;
int rc;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_inode->i_op->readlink) {
rc = -EINVAL;
goto out;
}
mount_crypt_stat = &ecryptfs_superblock_to_private(
dentry->d_sb)->mount_crypt_stat;
/*
* If the lower filename is encrypted, it will result in a significantly
* longer name. If needed, truncate the name after decode and decrypt.
*/
if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)
lower_bufsiz = PATH_MAX;
else
lower_bufsiz = bufsiz;
/* Released in this function */
lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
if (lower_buf == NULL) {
printk(KERN_ERR "%s: Out of memory whilst attempting to "
"kmalloc [%zd] bytes\n", __func__, lower_bufsiz);
rc = -ENOMEM;
goto out;
}
old_fs = get_fs();
set_fs(get_ds());
rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
(char __user *)lower_buf,
lower_bufsiz);
set_fs(old_fs);
if (rc >= 0) {
rc = ecryptfs_decode_and_decrypt_filename(&plaintext_name,
&plaintext_name_size,
dentry, lower_buf,
rc);
if (rc) {
printk(KERN_ERR "%s: Error attempting to decode and "
"decrypt filename; rc = [%d]\n", __func__,
rc);
goto out_free_lower_buf;
}
/* Check for bufsiz <= 0 done in sys_readlinkat() */
rc = copy_to_user(buf, plaintext_name,
min((size_t) bufsiz, plaintext_name_size));
if (rc)
rc = -EFAULT;
else
rc = plaintext_name_size;
kfree(plaintext_name);
fsstack_copy_attr_atime(dentry->d_inode, lower_dentry->d_inode);
}
out_free_lower_buf:
kfree(lower_buf);
out:
return rc;
}
static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
{
char *buf;
int len = PAGE_SIZE, rc;
mm_segment_t old_fs;
/* Released in ecryptfs_put_link(); only release here on error */
buf = kmalloc(len, GFP_KERNEL);
if (!buf) {
buf = ERR_PTR(-ENOMEM);
goto out;
}
old_fs = get_fs();
set_fs(get_ds());
rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
set_fs(old_fs);
if (rc < 0) {
kfree(buf);
buf = ERR_PTR(rc);
} else
buf[rc] = '\0';
out:
nd_set_link(nd, buf);
return NULL;
}
static void
ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
{
char *buf = nd_get_link(nd);
if (!IS_ERR(buf)) {
/* Free the char* */
kfree(buf);
}
}
/**
* upper_size_to_lower_size
* @crypt_stat: Crypt_stat associated with file
* @upper_size: Size of the upper file
*
* Calculate the required size of the lower file based on the
* specified size of the upper file. This calculation is based on the
* number of headers in the underlying file and the extent size.
*
* Returns Calculated size of the lower file.
*/
static loff_t
upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
loff_t upper_size)
{
loff_t lower_size;
lower_size = crypt_stat->num_header_bytes_at_front;
if (upper_size != 0) {
loff_t num_extents;
num_extents = upper_size >> crypt_stat->extent_shift;
if (upper_size & ~crypt_stat->extent_mask)
num_extents++;
lower_size += (num_extents * crypt_stat->extent_size);
}
return lower_size;
}
/**
* truncate_upper
* @dentry: The ecryptfs layer dentry
* @ia: Address of the ecryptfs inode's attributes
* @lower_ia: Address of the lower inode's attributes
*
* Function to handle truncations modifying the size of the file. Note
* that the file sizes are interpolated. When expanding, we are simply
* writing strings of 0's out. When truncating, we truncate the upper
* inode and update the lower_ia according to the page index
* interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
* the caller must use lower_ia in a call to notify_change() to perform
* the truncation of the lower inode.
*
* Returns zero on success; non-zero otherwise
*/
static int truncate_upper(struct dentry *dentry, struct iattr *ia,
struct iattr *lower_ia)
{
int rc = 0;
struct inode *inode = dentry->d_inode;
struct dentry *lower_dentry;
struct file fake_ecryptfs_file;
struct ecryptfs_crypt_stat *crypt_stat;
loff_t i_size = i_size_read(inode);
loff_t lower_size_before_truncate;
loff_t lower_size_after_truncate;
if (unlikely((ia->ia_size == i_size))) {
lower_ia->ia_valid &= ~ATTR_SIZE;
goto out;
}
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
/* Set up a fake ecryptfs file, this is used to interface with
* the file in the underlying filesystem so that the
* truncation has an effect there as well. */
memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
fake_ecryptfs_file.f_path.dentry = dentry;
/* Released at out_free: label */
ecryptfs_set_file_private(&fake_ecryptfs_file,
kmem_cache_alloc(ecryptfs_file_info_cache,
GFP_KERNEL));
if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
rc = -ENOMEM;
goto out;
}
lower_dentry = ecryptfs_dentry_to_lower(dentry);
ecryptfs_set_file_lower(
&fake_ecryptfs_file,
ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
/* Switch on growing or shrinking file */
if (ia->ia_size > i_size) {
char zero[] = { 0x00 };
lower_ia->ia_valid &= ~ATTR_SIZE;
/* Write a single 0 at the last position of the file;
* this triggers code that will fill in 0's throughout
* the intermediate portion of the previous end of the
* file and the new and of the file */
rc = ecryptfs_write(&fake_ecryptfs_file, zero,
(ia->ia_size - 1), 1);
} else { /* ia->ia_size < i_size_read(inode) */
/* We're chopping off all the pages down to the page
* in which ia->ia_size is located. Fill in the end of
* that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
* PAGE_CACHE_SIZE with zeros. */
size_t num_zeros = (PAGE_CACHE_SIZE
- (ia->ia_size & ~PAGE_CACHE_MASK));
if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
rc = vmtruncate(inode, ia->ia_size);
if (rc)
goto out_free;
lower_ia->ia_size = ia->ia_size;
lower_ia->ia_valid |= ATTR_SIZE;
goto out_free;
}
if (num_zeros) {
char *zeros_virt;
zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
if (!zeros_virt) {
rc = -ENOMEM;
goto out_free;
}
rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
ia->ia_size, num_zeros);
kfree(zeros_virt);
if (rc) {
printk(KERN_ERR "Error attempting to zero out "
"the remainder of the end page on "
"reducing truncate; rc = [%d]\n", rc);
goto out_free;
}
}
vmtruncate(inode, ia->ia_size);
rc = ecryptfs_write_inode_size_to_metadata(inode);
if (rc) {
printk(KERN_ERR "Problem with "
"ecryptfs_write_inode_size_to_metadata; "
"rc = [%d]\n", rc);
goto out_free;
}
/* We are reducing the size of the ecryptfs file, and need to
* know if we need to reduce the size of the lower file. */
lower_size_before_truncate =
upper_size_to_lower_size(crypt_stat, i_size);
lower_size_after_truncate =
upper_size_to_lower_size(crypt_stat, ia->ia_size);
if (lower_size_after_truncate < lower_size_before_truncate) {
lower_ia->ia_size = lower_size_after_truncate;
lower_ia->ia_valid |= ATTR_SIZE;
} else
lower_ia->ia_valid &= ~ATTR_SIZE;
}
out_free:
if (ecryptfs_file_to_private(&fake_ecryptfs_file))
kmem_cache_free(ecryptfs_file_info_cache,
ecryptfs_file_to_private(&fake_ecryptfs_file));
out:
return rc;
}
/**
* ecryptfs_truncate
* @dentry: The ecryptfs layer dentry
* @new_length: The length to expand the file to
*
* Simple function that handles the truncation of an eCryptfs inode and
* its corresponding lower inode.
*
* Returns zero on success; non-zero otherwise
*/
int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
{
struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
struct iattr lower_ia = { .ia_valid = 0 };
int rc;
rc = truncate_upper(dentry, &ia, &lower_ia);
if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = notify_change(lower_dentry, &lower_ia);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
}
return rc;
}
static int
ecryptfs_permission(struct inode *inode, int mask)
{
return inode_permission(ecryptfs_inode_to_lower(inode), mask);
}
/**
* ecryptfs_setattr
* @dentry: dentry handle to the inode to modify
* @ia: Structure with flags of what to change and values
*
* Updates the metadata of an inode. If the update is to the size
* i.e. truncation, then ecryptfs_truncate will handle the size modification
* of both the ecryptfs inode and the lower inode.
*
* All other metadata changes will be passed right to the lower filesystem,
* and we will just update our inode to look like the lower.
*/
static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
{
int rc = 0;
struct dentry *lower_dentry;
struct iattr lower_ia;
struct inode *inode;
struct inode *lower_inode;
struct ecryptfs_crypt_stat *crypt_stat;
crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
ecryptfs_init_crypt_stat(crypt_stat);
inode = dentry->d_inode;
lower_inode = ecryptfs_inode_to_lower(inode);
lower_dentry = ecryptfs_dentry_to_lower(dentry);
mutex_lock(&crypt_stat->cs_mutex);
if (S_ISDIR(dentry->d_inode->i_mode))
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
else if (S_ISREG(dentry->d_inode->i_mode)
&& (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
|| !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
mount_crypt_stat = &ecryptfs_superblock_to_private(
dentry->d_sb)->mount_crypt_stat;
rc = ecryptfs_read_metadata(dentry);
if (rc) {
if (!(mount_crypt_stat->flags
& ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
rc = -EIO;
printk(KERN_WARNING "Either the lower file "
"is not in a valid eCryptfs format, "
"or the key could not be retrieved. "
"Plaintext passthrough mode is not "
"enabled; returning -EIO\n");
mutex_unlock(&crypt_stat->cs_mutex);
goto out;
}
rc = 0;
crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
}
}
mutex_unlock(&crypt_stat->cs_mutex);
memcpy(&lower_ia, ia, sizeof(lower_ia));
if (ia->ia_valid & ATTR_FILE)
lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
if (ia->ia_valid & ATTR_SIZE) {
rc = truncate_upper(dentry, ia, &lower_ia);
if (rc < 0)
goto out;
}
/*
* mode change is for clearing setuid/setgid bits. Allow lower fs
* to interpret this in its own way.
*/
if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
lower_ia.ia_valid &= ~ATTR_MODE;
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = notify_change(lower_dentry, &lower_ia);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
fsstack_copy_attr_all(inode, lower_inode);
return rc;
}
int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
struct kstat *stat)
{
struct kstat lower_stat;
int rc;
rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
ecryptfs_dentry_to_lower(dentry), &lower_stat);
if (!rc) {
generic_fillattr(dentry->d_inode, stat);
stat->blocks = lower_stat.blocks;
}
return rc;
}
int
ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
size_t size, int flags)
{
int rc = 0;
struct dentry *lower_dentry;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_inode->i_op->setxattr) {
rc = -ENOSYS;
goto out;
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
size, flags);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
return rc;
}
ssize_t
ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
void *value, size_t size)
{
int rc = 0;
if (!lower_dentry->d_inode->i_op->getxattr) {
rc = -ENOSYS;
goto out;
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
size);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
return rc;
}
static ssize_t
ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
size_t size)
{
return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
value, size);
}
static ssize_t
ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
{
int rc = 0;
struct dentry *lower_dentry;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_inode->i_op->listxattr) {
rc = -ENOSYS;
goto out;
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
return rc;
}
static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
{
int rc = 0;
struct dentry *lower_dentry;
lower_dentry = ecryptfs_dentry_to_lower(dentry);
if (!lower_dentry->d_inode->i_op->removexattr) {
rc = -ENOSYS;
goto out;
}
mutex_lock(&lower_dentry->d_inode->i_mutex);
rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
mutex_unlock(&lower_dentry->d_inode->i_mutex);
out:
return rc;
}
int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
{
if ((ecryptfs_inode_to_lower(inode)
== (struct inode *)candidate_lower_inode))
return 1;
else
return 0;
}
int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
{
ecryptfs_init_inode(inode, (struct inode *)lower_inode);
return 0;
}
const struct inode_operations ecryptfs_symlink_iops = {
.readlink = ecryptfs_readlink,
.follow_link = ecryptfs_follow_link,
.put_link = ecryptfs_put_link,
.permission = ecryptfs_permission,
.setattr = ecryptfs_setattr,
.setxattr = ecryptfs_setxattr,
.getxattr = ecryptfs_getxattr,
.listxattr = ecryptfs_listxattr,
.removexattr = ecryptfs_removexattr
};
const struct inode_operations ecryptfs_dir_iops = {
.create = ecryptfs_create,
.lookup = ecryptfs_lookup,
.link = ecryptfs_link,
.unlink = ecryptfs_unlink,
.symlink = ecryptfs_symlink,
.mkdir = ecryptfs_mkdir,
.rmdir = ecryptfs_rmdir,
.mknod = ecryptfs_mknod,
.rename = ecryptfs_rename,
.permission = ecryptfs_permission,
.setattr = ecryptfs_setattr,
.setxattr = ecryptfs_setxattr,
.getxattr = ecryptfs_getxattr,
.listxattr = ecryptfs_listxattr,
.removexattr = ecryptfs_removexattr
};
const struct inode_operations ecryptfs_main_iops = {
.permission = ecryptfs_permission,
.setattr = ecryptfs_setattr,
.getattr = ecryptfs_getattr,
.setxattr = ecryptfs_setxattr,
.getxattr = ecryptfs_getxattr,
.listxattr = ecryptfs_listxattr,
.removexattr = ecryptfs_removexattr
};
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