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
,
286 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
288 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
292 if (S_ISDIR(lower_inode
->i_mode
))
294 if (S_ISLNK(lower_inode
->i_mode
))
296 if (special_file(lower_inode
->i_mode
))
300 /* Released in this function */
301 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
303 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
308 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
309 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
311 printk(KERN_ERR
"%s: Error attempting to initialize "
312 "the persistent file for the dentry with name "
313 "[%s]; rc = [%d]\n", __func__
,
314 ecryptfs_dentry
->d_name
.name
, rc
);
318 crypt_stat
= &ecryptfs_inode_to_private(
319 ecryptfs_dentry
->d_inode
)->crypt_stat
;
320 /* TODO: lock for crypt_stat comparison */
321 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
322 ecryptfs_set_default_sizes(crypt_stat
);
323 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
324 ecryptfs_dentry
->d_inode
);
326 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
332 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
334 mount_crypt_stat
= &ecryptfs_superblock_to_private(
335 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
336 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
337 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
338 file_size
= (crypt_stat
->num_header_bytes_at_front
339 + i_size_read(lower_dentry
->d_inode
));
341 file_size
= i_size_read(lower_dentry
->d_inode
);
343 file_size
= get_unaligned_be64(page_virt
);
345 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
347 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
351 d_drop(ecryptfs_dentry
);
358 * @ecryptfs_dir_inode: The eCryptfs directory inode
359 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
360 * @ecryptfs_nd: nameidata; may be NULL
362 * Find a file on disk. If the file does not exist, then we'll add it to the
363 * dentry cache and continue on to read it from the disk.
365 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
366 struct dentry
*ecryptfs_dentry
,
367 struct nameidata
*ecryptfs_nd
)
369 char *encrypted_and_encoded_name
= NULL
;
370 size_t encrypted_and_encoded_name_size
;
371 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
372 struct dentry
*lower_dir_dentry
, *lower_dentry
;
375 ecryptfs_dentry
->d_op
= &ecryptfs_dops
;
376 if ((ecryptfs_dentry
->d_name
.len
== 1
377 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
378 || (ecryptfs_dentry
->d_name
.len
== 2
379 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
382 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
383 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
384 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
386 ecryptfs_dentry
->d_name
.len
);
387 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
388 if (IS_ERR(lower_dentry
)) {
389 rc
= PTR_ERR(lower_dentry
);
390 printk(KERN_ERR
"%s: lookup_one_len() returned [%d] on "
391 "lower_dentry = [%s]\n", __func__
, rc
,
392 ecryptfs_dentry
->d_name
.name
);
395 if (lower_dentry
->d_inode
)
396 goto lookup_and_interpose
;
397 mount_crypt_stat
= &ecryptfs_superblock_to_private(
398 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
399 if (!(mount_crypt_stat
400 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
401 goto lookup_and_interpose
;
403 rc
= ecryptfs_encrypt_and_encode_filename(
404 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
405 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
406 ecryptfs_dentry
->d_name
.len
);
408 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
409 "filename; rc = [%d]\n", __func__
, rc
);
412 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
413 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
415 encrypted_and_encoded_name_size
- 1);
416 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
417 if (IS_ERR(lower_dentry
)) {
418 rc
= PTR_ERR(lower_dentry
);
419 printk(KERN_ERR
"%s: lookup_one_len() returned [%d] on "
420 "lower_dentry = [%s]\n", __func__
, rc
,
421 encrypted_and_encoded_name
);
424 lookup_and_interpose
:
425 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
430 d_drop(ecryptfs_dentry
);
432 kfree(encrypted_and_encoded_name
);
436 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
437 struct dentry
*new_dentry
)
439 struct dentry
*lower_old_dentry
;
440 struct dentry
*lower_new_dentry
;
441 struct dentry
*lower_dir_dentry
;
445 file_size_save
= i_size_read(old_dentry
->d_inode
);
446 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
447 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
448 dget(lower_old_dentry
);
449 dget(lower_new_dentry
);
450 lower_dir_dentry
= lock_parent(lower_new_dentry
);
451 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
453 if (rc
|| !lower_new_dentry
->d_inode
)
455 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
458 fsstack_copy_attr_times(dir
, lower_new_dentry
->d_inode
);
459 fsstack_copy_inode_size(dir
, lower_new_dentry
->d_inode
);
460 old_dentry
->d_inode
->i_nlink
=
461 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
462 i_size_write(new_dentry
->d_inode
, file_size_save
);
464 unlock_dir(lower_dir_dentry
);
465 dput(lower_new_dentry
);
466 dput(lower_old_dentry
);
470 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
473 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
474 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
475 struct dentry
*lower_dir_dentry
;
478 lower_dir_dentry
= lock_parent(lower_dentry
);
479 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
481 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
484 fsstack_copy_attr_times(dir
, lower_dir_inode
);
485 dentry
->d_inode
->i_nlink
=
486 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
487 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
490 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
;
615 struct dentry
*trap
= NULL
;
617 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
618 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
619 dget(lower_old_dentry
);
620 dget(lower_new_dentry
);
621 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
622 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
623 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
624 /* source should not be ancestor of target */
625 if (trap
== lower_old_dentry
) {
629 /* target should not be ancestor of source */
630 if (trap
== lower_new_dentry
) {
634 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
635 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
638 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
639 if (new_dir
!= old_dir
)
640 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
642 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
643 dput(lower_new_dentry
->d_parent
);
644 dput(lower_old_dentry
->d_parent
);
645 dput(lower_new_dentry
);
646 dput(lower_old_dentry
);
651 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
655 struct dentry
*lower_dentry
;
656 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
657 char *plaintext_name
;
658 size_t plaintext_name_size
;
662 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
663 if (!lower_dentry
->d_inode
->i_op
->readlink
) {
667 mount_crypt_stat
= &ecryptfs_superblock_to_private(
668 dentry
->d_sb
)->mount_crypt_stat
;
670 * If the lower filename is encrypted, it will result in a significantly
671 * longer name. If needed, truncate the name after decode and decrypt.
673 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)
674 lower_bufsiz
= PATH_MAX
;
676 lower_bufsiz
= bufsiz
;
677 /* Released in this function */
678 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
679 if (lower_buf
== NULL
) {
680 printk(KERN_ERR
"%s: Out of memory whilst attempting to "
681 "kmalloc [%zd] bytes\n", __func__
, lower_bufsiz
);
687 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
688 (char __user
*)lower_buf
,
692 rc
= ecryptfs_decode_and_decrypt_filename(&plaintext_name
,
693 &plaintext_name_size
,
697 printk(KERN_ERR
"%s: Error attempting to decode and "
698 "decrypt filename; rc = [%d]\n", __func__
,
700 goto out_free_lower_buf
;
702 /* Check for bufsiz <= 0 done in sys_readlinkat() */
703 rc
= copy_to_user(buf
, plaintext_name
,
704 min((size_t) bufsiz
, plaintext_name_size
));
708 rc
= plaintext_name_size
;
709 kfree(plaintext_name
);
710 fsstack_copy_attr_atime(dentry
->d_inode
, lower_dentry
->d_inode
);
718 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
721 int len
= PAGE_SIZE
, rc
;
724 /* Released in ecryptfs_put_link(); only release here on error */
725 buf
= kmalloc(len
, GFP_KERNEL
);
727 buf
= ERR_PTR(-ENOMEM
);
732 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
740 nd_set_link(nd
, buf
);
745 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
747 char *buf
= nd_get_link(nd
);
755 * upper_size_to_lower_size
756 * @crypt_stat: Crypt_stat associated with file
757 * @upper_size: Size of the upper file
759 * Calculate the required size of the lower file based on the
760 * specified size of the upper file. This calculation is based on the
761 * number of headers in the underlying file and the extent size.
763 * Returns Calculated size of the lower file.
766 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
771 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
772 if (upper_size
!= 0) {
775 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
776 if (upper_size
& ~crypt_stat
->extent_mask
)
778 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
785 * @dentry: The ecryptfs layer dentry
786 * @ia: Address of the ecryptfs inode's attributes
787 * @lower_ia: Address of the lower inode's attributes
789 * Function to handle truncations modifying the size of the file. Note
790 * that the file sizes are interpolated. When expanding, we are simply
791 * writing strings of 0's out. When truncating, we truncate the upper
792 * inode and update the lower_ia according to the page index
793 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
794 * the caller must use lower_ia in a call to notify_change() to perform
795 * the truncation of the lower inode.
797 * Returns zero on success; non-zero otherwise
799 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
800 struct iattr
*lower_ia
)
803 struct inode
*inode
= dentry
->d_inode
;
804 struct dentry
*lower_dentry
;
805 struct file fake_ecryptfs_file
;
806 struct ecryptfs_crypt_stat
*crypt_stat
;
807 loff_t i_size
= i_size_read(inode
);
808 loff_t lower_size_before_truncate
;
809 loff_t lower_size_after_truncate
;
811 if (unlikely((ia
->ia_size
== i_size
))) {
812 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
815 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
816 /* Set up a fake ecryptfs file, this is used to interface with
817 * the file in the underlying filesystem so that the
818 * truncation has an effect there as well. */
819 memset(&fake_ecryptfs_file
, 0, sizeof(fake_ecryptfs_file
));
820 fake_ecryptfs_file
.f_path
.dentry
= dentry
;
821 /* Released at out_free: label */
822 ecryptfs_set_file_private(&fake_ecryptfs_file
,
823 kmem_cache_alloc(ecryptfs_file_info_cache
,
825 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file
))) {
829 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
830 ecryptfs_set_file_lower(
832 ecryptfs_inode_to_private(dentry
->d_inode
)->lower_file
);
833 /* Switch on growing or shrinking file */
834 if (ia
->ia_size
> i_size
) {
835 char zero
[] = { 0x00 };
837 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
838 /* Write a single 0 at the last position of the file;
839 * this triggers code that will fill in 0's throughout
840 * the intermediate portion of the previous end of the
841 * file and the new and of the file */
842 rc
= ecryptfs_write(&fake_ecryptfs_file
, zero
,
843 (ia
->ia_size
- 1), 1);
844 } else { /* ia->ia_size < i_size_read(inode) */
845 /* We're chopping off all the pages down to the page
846 * in which ia->ia_size is located. Fill in the end of
847 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
848 * PAGE_CACHE_SIZE with zeros. */
849 size_t num_zeros
= (PAGE_CACHE_SIZE
850 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
852 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
853 rc
= vmtruncate(inode
, ia
->ia_size
);
856 lower_ia
->ia_size
= ia
->ia_size
;
857 lower_ia
->ia_valid
|= ATTR_SIZE
;
863 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
868 rc
= ecryptfs_write(&fake_ecryptfs_file
, zeros_virt
,
869 ia
->ia_size
, num_zeros
);
872 printk(KERN_ERR
"Error attempting to zero out "
873 "the remainder of the end page on "
874 "reducing truncate; rc = [%d]\n", rc
);
878 vmtruncate(inode
, ia
->ia_size
);
879 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
881 printk(KERN_ERR
"Problem with "
882 "ecryptfs_write_inode_size_to_metadata; "
886 /* We are reducing the size of the ecryptfs file, and need to
887 * know if we need to reduce the size of the lower file. */
888 lower_size_before_truncate
=
889 upper_size_to_lower_size(crypt_stat
, i_size
);
890 lower_size_after_truncate
=
891 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
892 if (lower_size_after_truncate
< lower_size_before_truncate
) {
893 lower_ia
->ia_size
= lower_size_after_truncate
;
894 lower_ia
->ia_valid
|= ATTR_SIZE
;
896 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
899 if (ecryptfs_file_to_private(&fake_ecryptfs_file
))
900 kmem_cache_free(ecryptfs_file_info_cache
,
901 ecryptfs_file_to_private(&fake_ecryptfs_file
));
908 * @dentry: The ecryptfs layer dentry
909 * @new_length: The length to expand the file to
911 * Simple function that handles the truncation of an eCryptfs inode and
912 * its corresponding lower inode.
914 * Returns zero on success; non-zero otherwise
916 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
918 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
919 struct iattr lower_ia
= { .ia_valid
= 0 };
922 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
923 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
924 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
926 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
927 rc
= notify_change(lower_dentry
, &lower_ia
);
928 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
934 ecryptfs_permission(struct inode
*inode
, int mask
)
936 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
941 * @dentry: dentry handle to the inode to modify
942 * @ia: Structure with flags of what to change and values
944 * Updates the metadata of an inode. If the update is to the size
945 * i.e. truncation, then ecryptfs_truncate will handle the size modification
946 * of both the ecryptfs inode and the lower inode.
948 * All other metadata changes will be passed right to the lower filesystem,
949 * and we will just update our inode to look like the lower.
951 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
954 struct dentry
*lower_dentry
;
955 struct iattr lower_ia
;
957 struct inode
*lower_inode
;
958 struct ecryptfs_crypt_stat
*crypt_stat
;
960 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
961 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
962 ecryptfs_init_crypt_stat(crypt_stat
);
963 inode
= dentry
->d_inode
;
964 lower_inode
= ecryptfs_inode_to_lower(inode
);
965 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
966 mutex_lock(&crypt_stat
->cs_mutex
);
967 if (S_ISDIR(dentry
->d_inode
->i_mode
))
968 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
969 else if (S_ISREG(dentry
->d_inode
->i_mode
)
970 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
971 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
972 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
974 mount_crypt_stat
= &ecryptfs_superblock_to_private(
975 dentry
->d_sb
)->mount_crypt_stat
;
976 rc
= ecryptfs_read_metadata(dentry
);
978 if (!(mount_crypt_stat
->flags
979 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
981 printk(KERN_WARNING
"Either the lower file "
982 "is not in a valid eCryptfs format, "
983 "or the key could not be retrieved. "
984 "Plaintext passthrough mode is not "
985 "enabled; returning -EIO\n");
986 mutex_unlock(&crypt_stat
->cs_mutex
);
990 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
993 mutex_unlock(&crypt_stat
->cs_mutex
);
994 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
995 if (ia
->ia_valid
& ATTR_FILE
)
996 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
997 if (ia
->ia_valid
& ATTR_SIZE
) {
998 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1004 * mode change is for clearing setuid/setgid bits. Allow lower fs
1005 * to interpret this in its own way.
1007 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1008 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1010 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1011 rc
= notify_change(lower_dentry
, &lower_ia
);
1012 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1014 fsstack_copy_attr_all(inode
, lower_inode
);
1018 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1021 struct kstat lower_stat
;
1024 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1025 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1027 generic_fillattr(dentry
->d_inode
, stat
);
1028 stat
->blocks
= lower_stat
.blocks
;
1034 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1035 size_t size
, int flags
)
1038 struct dentry
*lower_dentry
;
1040 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1041 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1045 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1046 rc
= lower_dentry
->d_inode
->i_op
->setxattr(lower_dentry
, name
, value
,
1048 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1054 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1055 void *value
, size_t size
)
1059 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1063 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1064 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1066 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1072 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1075 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1080 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1083 struct dentry
*lower_dentry
;
1085 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1086 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1090 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1091 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1092 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1097 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1100 struct dentry
*lower_dentry
;
1102 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1103 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1107 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1108 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1109 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1114 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1116 if ((ecryptfs_inode_to_lower(inode
)
1117 == (struct inode
*)candidate_lower_inode
))
1123 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1125 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1129 const struct inode_operations ecryptfs_symlink_iops
= {
1130 .readlink
= ecryptfs_readlink
,
1131 .follow_link
= ecryptfs_follow_link
,
1132 .put_link
= ecryptfs_put_link
,
1133 .permission
= ecryptfs_permission
,
1134 .setattr
= ecryptfs_setattr
,
1135 .setxattr
= ecryptfs_setxattr
,
1136 .getxattr
= ecryptfs_getxattr
,
1137 .listxattr
= ecryptfs_listxattr
,
1138 .removexattr
= ecryptfs_removexattr
1141 const struct inode_operations ecryptfs_dir_iops
= {
1142 .create
= ecryptfs_create
,
1143 .lookup
= ecryptfs_lookup
,
1144 .link
= ecryptfs_link
,
1145 .unlink
= ecryptfs_unlink
,
1146 .symlink
= ecryptfs_symlink
,
1147 .mkdir
= ecryptfs_mkdir
,
1148 .rmdir
= ecryptfs_rmdir
,
1149 .mknod
= ecryptfs_mknod
,
1150 .rename
= ecryptfs_rename
,
1151 .permission
= ecryptfs_permission
,
1152 .setattr
= ecryptfs_setattr
,
1153 .setxattr
= ecryptfs_setxattr
,
1154 .getxattr
= ecryptfs_getxattr
,
1155 .listxattr
= ecryptfs_listxattr
,
1156 .removexattr
= ecryptfs_removexattr
1159 const struct inode_operations ecryptfs_main_iops
= {
1160 .permission
= ecryptfs_permission
,
1161 .setattr
= ecryptfs_setattr
,
1162 .getattr
= ecryptfs_getattr
,
1163 .setxattr
= ecryptfs_setxattr
,
1164 .getxattr
= ecryptfs_getxattr
,
1165 .listxattr
= ecryptfs_listxattr
,
1166 .removexattr
= ecryptfs_removexattr