2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <asm/unaligned.h>
35 #include "ecryptfs_kernel.h"
37 static struct dentry
*lock_parent(struct dentry
*dentry
)
41 dir
= dget_parent(dentry
);
42 mutex_lock_nested(&(dir
->d_inode
->i_mutex
), I_MUTEX_PARENT
);
46 static void unlock_dir(struct dentry
*dir
)
48 mutex_unlock(&dir
->d_inode
->i_mutex
);
53 * ecryptfs_create_underlying_file
54 * @lower_dir_inode: inode of the parent in the lower fs of the new file
55 * @dentry: New file's dentry
56 * @mode: The mode of the new file
57 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
59 * Creates the file in the lower file system.
61 * Returns zero on success; non-zero on error condition
64 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
65 struct dentry
*dentry
, int mode
,
68 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
69 struct vfsmount
*lower_mnt
= ecryptfs_dentry_to_lower_mnt(dentry
);
70 struct dentry
*dentry_save
;
71 struct vfsmount
*vfsmount_save
;
74 dentry_save
= nd
->path
.dentry
;
75 vfsmount_save
= nd
->path
.mnt
;
76 nd
->path
.dentry
= lower_dentry
;
77 nd
->path
.mnt
= lower_mnt
;
78 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
79 nd
->path
.dentry
= dentry_save
;
80 nd
->path
.mnt
= vfsmount_save
;
86 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
87 * @ecryptfs_dentry: New file's dentry in ecryptfs
88 * @mode: The mode of the new file
89 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
91 * Creates the underlying file and the eCryptfs inode which will link to
92 * it. It will also update the eCryptfs directory inode to mimic the
93 * stat of the lower directory inode.
95 * Returns zero on success; non-zero on error condition
98 ecryptfs_do_create(struct inode
*directory_inode
,
99 struct dentry
*ecryptfs_dentry
, int mode
,
100 struct nameidata
*nd
)
103 struct dentry
*lower_dentry
;
104 struct dentry
*lower_dir_dentry
;
106 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
107 lower_dir_dentry
= lock_parent(lower_dentry
);
108 if (IS_ERR(lower_dir_dentry
)) {
109 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
111 rc
= PTR_ERR(lower_dir_dentry
);
114 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
115 ecryptfs_dentry
, mode
, nd
);
117 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
118 "rc = [%d]\n", __func__
, rc
);
121 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
122 directory_inode
->i_sb
, 0);
124 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
127 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
128 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
130 unlock_dir(lower_dir_dentry
);
137 * @ecryptfs_dentry: the eCryptfs dentry
139 * This is the code which will grow the file to its correct size.
141 static int grow_file(struct dentry
*ecryptfs_dentry
)
143 struct inode
*ecryptfs_inode
= ecryptfs_dentry
->d_inode
;
144 struct file fake_file
;
145 struct ecryptfs_file_info tmp_file_info
;
146 char zero_virt
[] = { 0x00 };
149 memset(&fake_file
, 0, sizeof(fake_file
));
150 fake_file
.f_path
.dentry
= ecryptfs_dentry
;
151 memset(&tmp_file_info
, 0, sizeof(tmp_file_info
));
152 ecryptfs_set_file_private(&fake_file
, &tmp_file_info
);
153 ecryptfs_set_file_lower(
155 ecryptfs_inode_to_private(ecryptfs_inode
)->lower_file
);
156 rc
= ecryptfs_write(&fake_file
, zero_virt
, 0, 1);
157 i_size_write(ecryptfs_inode
, 0);
158 rc
= ecryptfs_write_inode_size_to_metadata(ecryptfs_inode
);
159 ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
.flags
|=
165 * ecryptfs_initialize_file
167 * Cause the file to be changed from a basic empty file to an ecryptfs
168 * file with a header and first data page.
170 * Returns zero on success
172 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
174 struct ecryptfs_crypt_stat
*crypt_stat
=
175 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
178 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
179 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
180 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
183 crypt_stat
->flags
|= ECRYPTFS_NEW_FILE
;
184 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
185 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
187 ecryptfs_printk(KERN_ERR
, "Error creating new file "
188 "context; rc = [%d]\n", rc
);
191 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
192 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
194 printk(KERN_ERR
"%s: Error attempting to initialize "
195 "the persistent file for the dentry with name "
196 "[%s]; rc = [%d]\n", __func__
,
197 ecryptfs_dentry
->d_name
.name
, rc
);
201 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
203 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
206 rc
= grow_file(ecryptfs_dentry
);
208 printk(KERN_ERR
"Error growing file; rc = [%d]\n", rc
);
215 * @dir: The inode of the directory in which to create the file.
216 * @dentry: The eCryptfs dentry
217 * @mode: The mode of the new file.
220 * Creates a new file.
222 * Returns zero on success; non-zero on error condition
225 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
226 int mode
, struct nameidata
*nd
)
230 /* ecryptfs_do_create() calls ecryptfs_interpose() */
231 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
233 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
234 "lower filesystem\n");
237 /* At this point, a file exists on "disk"; we need to make sure
238 * that this on disk file is prepared to be an ecryptfs file */
239 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
245 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
247 int ecryptfs_lookup_and_interpose_lower(struct dentry
*ecryptfs_dentry
,
248 struct dentry
*lower_dentry
,
249 struct inode
*ecryptfs_dir_inode
,
250 struct nameidata
*ecryptfs_nd
)
252 struct dentry
*lower_dir_dentry
;
253 struct vfsmount
*lower_mnt
;
254 struct inode
*lower_inode
;
255 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
256 struct ecryptfs_crypt_stat
*crypt_stat
;
257 char *page_virt
= NULL
;
261 lower_dir_dentry
= lower_dentry
->d_parent
;
262 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
263 ecryptfs_dentry
->d_parent
));
264 lower_inode
= lower_dentry
->d_inode
;
265 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
266 BUG_ON(!atomic_read(&lower_dentry
->d_count
));
267 ecryptfs_set_dentry_private(ecryptfs_dentry
,
268 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
270 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
272 printk(KERN_ERR
"%s: Out of memory whilst attempting "
273 "to allocate ecryptfs_dentry_info struct\n",
277 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
278 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
279 if (!lower_dentry
->d_inode
) {
280 /* We want to add because we couldn't find in lower */
281 d_add(ecryptfs_dentry
, NULL
);
284 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
285 ecryptfs_dir_inode
->i_sb
, 1);
287 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
291 if (S_ISDIR(lower_inode
->i_mode
))
293 if (S_ISLNK(lower_inode
->i_mode
))
295 if (special_file(lower_inode
->i_mode
))
299 /* Released in this function */
300 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
302 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
307 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
308 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
310 printk(KERN_ERR
"%s: Error attempting to initialize "
311 "the persistent file for the dentry with name "
312 "[%s]; rc = [%d]\n", __func__
,
313 ecryptfs_dentry
->d_name
.name
, rc
);
317 crypt_stat
= &ecryptfs_inode_to_private(
318 ecryptfs_dentry
->d_inode
)->crypt_stat
;
319 /* TODO: lock for crypt_stat comparison */
320 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
321 ecryptfs_set_default_sizes(crypt_stat
);
322 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
323 ecryptfs_dentry
->d_inode
);
325 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
331 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
333 mount_crypt_stat
= &ecryptfs_superblock_to_private(
334 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
335 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
336 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
337 file_size
= (crypt_stat
->num_header_bytes_at_front
338 + i_size_read(lower_dentry
->d_inode
));
340 file_size
= i_size_read(lower_dentry
->d_inode
);
342 file_size
= get_unaligned_be64(page_virt
);
344 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
346 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
350 d_drop(ecryptfs_dentry
);
357 * @ecryptfs_dir_inode: The eCryptfs directory inode
358 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
359 * @ecryptfs_nd: nameidata; may be NULL
361 * Find a file on disk. If the file does not exist, then we'll add it to the
362 * dentry cache and continue on to read it from the disk.
364 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
365 struct dentry
*ecryptfs_dentry
,
366 struct nameidata
*ecryptfs_nd
)
368 char *encrypted_and_encoded_name
= NULL
;
369 size_t encrypted_and_encoded_name_size
;
370 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
371 struct dentry
*lower_dir_dentry
, *lower_dentry
;
374 ecryptfs_dentry
->d_op
= &ecryptfs_dops
;
375 if ((ecryptfs_dentry
->d_name
.len
== 1
376 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
377 || (ecryptfs_dentry
->d_name
.len
== 2
378 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
381 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
382 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
383 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
385 ecryptfs_dentry
->d_name
.len
);
386 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
387 if (IS_ERR(lower_dentry
)) {
388 rc
= PTR_ERR(lower_dentry
);
389 printk(KERN_ERR
"%s: lookup_one_len() returned [%d] on "
390 "lower_dentry = [%s]\n", __func__
, rc
,
391 ecryptfs_dentry
->d_name
.name
);
394 if (lower_dentry
->d_inode
)
395 goto lookup_and_interpose
;
396 mount_crypt_stat
= &ecryptfs_superblock_to_private(
397 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
398 if (!(mount_crypt_stat
399 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
400 goto lookup_and_interpose
;
402 rc
= ecryptfs_encrypt_and_encode_filename(
403 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
404 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
405 ecryptfs_dentry
->d_name
.len
);
407 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
408 "filename; rc = [%d]\n", __func__
, rc
);
411 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
412 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
414 encrypted_and_encoded_name_size
- 1);
415 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
416 if (IS_ERR(lower_dentry
)) {
417 rc
= PTR_ERR(lower_dentry
);
418 printk(KERN_ERR
"%s: lookup_one_len() returned [%d] on "
419 "lower_dentry = [%s]\n", __func__
, rc
,
420 encrypted_and_encoded_name
);
423 lookup_and_interpose
:
424 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
429 d_drop(ecryptfs_dentry
);
431 kfree(encrypted_and_encoded_name
);
435 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
436 struct dentry
*new_dentry
)
438 struct dentry
*lower_old_dentry
;
439 struct dentry
*lower_new_dentry
;
440 struct dentry
*lower_dir_dentry
;
444 file_size_save
= i_size_read(old_dentry
->d_inode
);
445 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
446 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
447 dget(lower_old_dentry
);
448 dget(lower_new_dentry
);
449 lower_dir_dentry
= lock_parent(lower_new_dentry
);
450 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
452 if (rc
|| !lower_new_dentry
->d_inode
)
454 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
457 fsstack_copy_attr_times(dir
, lower_new_dentry
->d_inode
);
458 fsstack_copy_inode_size(dir
, lower_new_dentry
->d_inode
);
459 old_dentry
->d_inode
->i_nlink
=
460 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
461 i_size_write(new_dentry
->d_inode
, file_size_save
);
463 unlock_dir(lower_dir_dentry
);
464 dput(lower_new_dentry
);
465 dput(lower_old_dentry
);
466 d_drop(lower_old_dentry
);
472 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
475 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
476 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
477 struct dentry
*lower_dir_dentry
;
479 lower_dir_dentry
= lock_parent(lower_dentry
);
480 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
482 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
485 fsstack_copy_attr_times(dir
, lower_dir_inode
);
486 dentry
->d_inode
->i_nlink
=
487 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
488 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
491 unlock_dir(lower_dir_dentry
);
495 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
499 struct dentry
*lower_dentry
;
500 struct dentry
*lower_dir_dentry
;
501 char *encoded_symname
;
502 size_t encoded_symlen
;
503 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
505 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
507 lower_dir_dentry
= lock_parent(lower_dentry
);
508 mount_crypt_stat
= &ecryptfs_superblock_to_private(
509 dir
->i_sb
)->mount_crypt_stat
;
510 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
513 mount_crypt_stat
, symname
,
517 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
519 kfree(encoded_symname
);
520 if (rc
|| !lower_dentry
->d_inode
)
522 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
525 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
526 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
528 unlock_dir(lower_dir_dentry
);
530 if (!dentry
->d_inode
)
535 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
538 struct dentry
*lower_dentry
;
539 struct dentry
*lower_dir_dentry
;
541 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
542 lower_dir_dentry
= lock_parent(lower_dentry
);
543 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
544 if (rc
|| !lower_dentry
->d_inode
)
546 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
549 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
550 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
551 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
553 unlock_dir(lower_dir_dentry
);
554 if (!dentry
->d_inode
)
559 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
561 struct dentry
*lower_dentry
;
562 struct dentry
*lower_dir_dentry
;
565 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
567 lower_dir_dentry
= lock_parent(lower_dentry
);
569 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
572 d_delete(lower_dentry
);
573 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
574 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
575 unlock_dir(lower_dir_dentry
);
583 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
586 struct dentry
*lower_dentry
;
587 struct dentry
*lower_dir_dentry
;
589 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
590 lower_dir_dentry
= lock_parent(lower_dentry
);
591 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
592 if (rc
|| !lower_dentry
->d_inode
)
594 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
597 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
598 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
600 unlock_dir(lower_dir_dentry
);
601 if (!dentry
->d_inode
)
607 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
608 struct inode
*new_dir
, struct dentry
*new_dentry
)
611 struct dentry
*lower_old_dentry
;
612 struct dentry
*lower_new_dentry
;
613 struct dentry
*lower_old_dir_dentry
;
614 struct dentry
*lower_new_dir_dentry
;
616 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
617 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
618 dget(lower_old_dentry
);
619 dget(lower_new_dentry
);
620 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
621 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
622 lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
623 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
624 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
627 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
, NULL
);
628 if (new_dir
!= old_dir
)
629 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
, NULL
);
631 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
632 dput(lower_new_dentry
->d_parent
);
633 dput(lower_old_dentry
->d_parent
);
634 dput(lower_new_dentry
);
635 dput(lower_old_dentry
);
640 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
643 struct dentry
*lower_dentry
;
644 struct ecryptfs_crypt_stat
*crypt_stat
;
645 char *plaintext_name
;
646 size_t plaintext_name_size
;
650 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
651 if (!lower_dentry
->d_inode
->i_op
->readlink
) {
655 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
656 /* Released in this function */
657 lower_buf
= kmalloc(bufsiz
, GFP_KERNEL
);
658 if (lower_buf
== NULL
) {
659 printk(KERN_ERR
"%s: Out of memory whilst attempting to "
660 "kmalloc [%d] bytes\n", __func__
, bufsiz
);
666 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
667 (char __user
*)lower_buf
,
671 rc
= ecryptfs_decode_and_decrypt_filename(&plaintext_name
,
672 &plaintext_name_size
,
676 printk(KERN_ERR
"%s: Error attempting to decode and "
677 "decrypt filename; rc = [%d]\n", __func__
,
679 goto out_free_lower_buf
;
681 rc
= copy_to_user(buf
, plaintext_name
, plaintext_name_size
);
685 rc
= plaintext_name_size
;
686 kfree(plaintext_name
);
687 fsstack_copy_attr_atime(dentry
->d_inode
, lower_dentry
->d_inode
);
695 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
698 int len
= PAGE_SIZE
, rc
;
701 /* Released in ecryptfs_put_link(); only release here on error */
702 buf
= kmalloc(len
, GFP_KERNEL
);
709 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
716 nd_set_link(nd
, buf
);
725 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
728 kfree(nd_get_link(nd
));
732 * upper_size_to_lower_size
733 * @crypt_stat: Crypt_stat associated with file
734 * @upper_size: Size of the upper file
736 * Calculate the required size of the lower file based on the
737 * specified size of the upper file. This calculation is based on the
738 * number of headers in the underlying file and the extent size.
740 * Returns Calculated size of the lower file.
743 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
748 lower_size
= crypt_stat
->num_header_bytes_at_front
;
749 if (upper_size
!= 0) {
752 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
753 if (upper_size
& ~crypt_stat
->extent_mask
)
755 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
762 * @dentry: The ecryptfs layer dentry
763 * @new_length: The length to expand the file to
765 * Function to handle truncations modifying the size of the file. Note
766 * that the file sizes are interpolated. When expanding, we are simply
767 * writing strings of 0's out. When truncating, we need to modify the
768 * underlying file size according to the page index interpolations.
770 * Returns zero on success; non-zero otherwise
772 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
775 struct inode
*inode
= dentry
->d_inode
;
776 struct dentry
*lower_dentry
;
777 struct file fake_ecryptfs_file
;
778 struct ecryptfs_crypt_stat
*crypt_stat
;
779 loff_t i_size
= i_size_read(inode
);
780 loff_t lower_size_before_truncate
;
781 loff_t lower_size_after_truncate
;
783 if (unlikely((new_length
== i_size
)))
785 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
786 /* Set up a fake ecryptfs file, this is used to interface with
787 * the file in the underlying filesystem so that the
788 * truncation has an effect there as well. */
789 memset(&fake_ecryptfs_file
, 0, sizeof(fake_ecryptfs_file
));
790 fake_ecryptfs_file
.f_path
.dentry
= dentry
;
791 /* Released at out_free: label */
792 ecryptfs_set_file_private(&fake_ecryptfs_file
,
793 kmem_cache_alloc(ecryptfs_file_info_cache
,
795 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file
))) {
799 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
800 ecryptfs_set_file_lower(
802 ecryptfs_inode_to_private(dentry
->d_inode
)->lower_file
);
803 /* Switch on growing or shrinking file */
804 if (new_length
> i_size
) {
805 char zero
[] = { 0x00 };
807 /* Write a single 0 at the last position of the file;
808 * this triggers code that will fill in 0's throughout
809 * the intermediate portion of the previous end of the
810 * file and the new and of the file */
811 rc
= ecryptfs_write(&fake_ecryptfs_file
, zero
,
812 (new_length
- 1), 1);
813 } else { /* new_length < i_size_read(inode) */
814 /* We're chopping off all the pages down do the page
815 * in which new_length is located. Fill in the end of
816 * that page from (new_length & ~PAGE_CACHE_MASK) to
817 * PAGE_CACHE_SIZE with zeros. */
818 size_t num_zeros
= (PAGE_CACHE_SIZE
819 - (new_length
& ~PAGE_CACHE_MASK
));
821 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
822 rc
= vmtruncate(inode
, new_length
);
825 rc
= vmtruncate(lower_dentry
->d_inode
, new_length
);
831 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
836 rc
= ecryptfs_write(&fake_ecryptfs_file
, zeros_virt
,
837 new_length
, num_zeros
);
840 printk(KERN_ERR
"Error attempting to zero out "
841 "the remainder of the end page on "
842 "reducing truncate; rc = [%d]\n", rc
);
846 vmtruncate(inode
, new_length
);
847 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
849 printk(KERN_ERR
"Problem with "
850 "ecryptfs_write_inode_size_to_metadata; "
854 /* We are reducing the size of the ecryptfs file, and need to
855 * know if we need to reduce the size of the lower file. */
856 lower_size_before_truncate
=
857 upper_size_to_lower_size(crypt_stat
, i_size
);
858 lower_size_after_truncate
=
859 upper_size_to_lower_size(crypt_stat
, new_length
);
860 if (lower_size_after_truncate
< lower_size_before_truncate
)
861 vmtruncate(lower_dentry
->d_inode
,
862 lower_size_after_truncate
);
865 if (ecryptfs_file_to_private(&fake_ecryptfs_file
))
866 kmem_cache_free(ecryptfs_file_info_cache
,
867 ecryptfs_file_to_private(&fake_ecryptfs_file
));
873 ecryptfs_permission(struct inode
*inode
, int mask
)
875 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
880 * @dentry: dentry handle to the inode to modify
881 * @ia: Structure with flags of what to change and values
883 * Updates the metadata of an inode. If the update is to the size
884 * i.e. truncation, then ecryptfs_truncate will handle the size modification
885 * of both the ecryptfs inode and the lower inode.
887 * All other metadata changes will be passed right to the lower filesystem,
888 * and we will just update our inode to look like the lower.
890 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
893 struct dentry
*lower_dentry
;
895 struct inode
*lower_inode
;
896 struct ecryptfs_crypt_stat
*crypt_stat
;
898 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
899 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
900 ecryptfs_init_crypt_stat(crypt_stat
);
901 inode
= dentry
->d_inode
;
902 lower_inode
= ecryptfs_inode_to_lower(inode
);
903 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
904 mutex_lock(&crypt_stat
->cs_mutex
);
905 if (S_ISDIR(dentry
->d_inode
->i_mode
))
906 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
907 else if (S_ISREG(dentry
->d_inode
->i_mode
)
908 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
909 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
910 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
912 mount_crypt_stat
= &ecryptfs_superblock_to_private(
913 dentry
->d_sb
)->mount_crypt_stat
;
914 rc
= ecryptfs_read_metadata(dentry
);
916 if (!(mount_crypt_stat
->flags
917 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
919 printk(KERN_WARNING
"Either the lower file "
920 "is not in a valid eCryptfs format, "
921 "or the key could not be retrieved. "
922 "Plaintext passthrough mode is not "
923 "enabled; returning -EIO\n");
924 mutex_unlock(&crypt_stat
->cs_mutex
);
928 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
931 mutex_unlock(&crypt_stat
->cs_mutex
);
932 if (ia
->ia_valid
& ATTR_SIZE
) {
933 ecryptfs_printk(KERN_DEBUG
,
934 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
935 ia
->ia_valid
, ATTR_SIZE
);
936 rc
= ecryptfs_truncate(dentry
, ia
->ia_size
);
937 /* ecryptfs_truncate handles resizing of the lower file */
938 ia
->ia_valid
&= ~ATTR_SIZE
;
939 ecryptfs_printk(KERN_DEBUG
, "ia->ia_valid = [%x]\n",
946 * mode change is for clearing setuid/setgid bits. Allow lower fs
947 * to interpret this in its own way.
949 if (ia
->ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
950 ia
->ia_valid
&= ~ATTR_MODE
;
952 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
953 rc
= notify_change(lower_dentry
, ia
);
954 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
956 fsstack_copy_attr_all(inode
, lower_inode
, NULL
);
961 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
962 size_t size
, int flags
)
965 struct dentry
*lower_dentry
;
967 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
968 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
972 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
973 rc
= lower_dentry
->d_inode
->i_op
->setxattr(lower_dentry
, name
, value
,
975 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
981 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
982 void *value
, size_t size
)
986 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
990 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
991 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
993 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
999 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1002 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1007 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1010 struct dentry
*lower_dentry
;
1012 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1013 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1017 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1018 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1019 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1024 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1027 struct dentry
*lower_dentry
;
1029 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1030 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1034 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1035 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1036 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1041 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1043 if ((ecryptfs_inode_to_lower(inode
)
1044 == (struct inode
*)candidate_lower_inode
))
1050 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1052 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1056 const struct inode_operations ecryptfs_symlink_iops
= {
1057 .readlink
= ecryptfs_readlink
,
1058 .follow_link
= ecryptfs_follow_link
,
1059 .put_link
= ecryptfs_put_link
,
1060 .permission
= ecryptfs_permission
,
1061 .setattr
= ecryptfs_setattr
,
1062 .setxattr
= ecryptfs_setxattr
,
1063 .getxattr
= ecryptfs_getxattr
,
1064 .listxattr
= ecryptfs_listxattr
,
1065 .removexattr
= ecryptfs_removexattr
1068 const struct inode_operations ecryptfs_dir_iops
= {
1069 .create
= ecryptfs_create
,
1070 .lookup
= ecryptfs_lookup
,
1071 .link
= ecryptfs_link
,
1072 .unlink
= ecryptfs_unlink
,
1073 .symlink
= ecryptfs_symlink
,
1074 .mkdir
= ecryptfs_mkdir
,
1075 .rmdir
= ecryptfs_rmdir
,
1076 .mknod
= ecryptfs_mknod
,
1077 .rename
= ecryptfs_rename
,
1078 .permission
= ecryptfs_permission
,
1079 .setattr
= ecryptfs_setattr
,
1080 .setxattr
= ecryptfs_setxattr
,
1081 .getxattr
= ecryptfs_getxattr
,
1082 .listxattr
= ecryptfs_listxattr
,
1083 .removexattr
= ecryptfs_removexattr
1086 const struct inode_operations ecryptfs_main_iops
= {
1087 .permission
= ecryptfs_permission
,
1088 .setattr
= ecryptfs_setattr
,
1089 .setxattr
= ecryptfs_setxattr
,
1090 .getxattr
= ecryptfs_getxattr
,
1091 .listxattr
= ecryptfs_listxattr
,
1092 .removexattr
= ecryptfs_removexattr