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 <linux/slab.h>
35 #include <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry
*lock_parent(struct dentry
*dentry
)
42 dir
= dget_parent(dentry
);
43 mutex_lock_nested(&(dir
->d_inode
->i_mutex
), I_MUTEX_PARENT
);
47 static void unlock_dir(struct dentry
*dir
)
49 mutex_unlock(&dir
->d_inode
->i_mutex
);
54 * ecryptfs_create_underlying_file
55 * @lower_dir_inode: inode of the parent in the lower fs of the new file
56 * @dentry: New file's dentry
57 * @mode: The mode of the new file
58 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
60 * Creates the file in the lower file system.
62 * Returns zero on success; non-zero on error condition
65 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
66 struct dentry
*dentry
, int mode
,
69 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
70 struct vfsmount
*lower_mnt
= ecryptfs_dentry_to_lower_mnt(dentry
);
71 struct dentry
*dentry_save
;
72 struct vfsmount
*vfsmount_save
;
75 dentry_save
= nd
->path
.dentry
;
76 vfsmount_save
= nd
->path
.mnt
;
77 nd
->path
.dentry
= lower_dentry
;
78 nd
->path
.mnt
= lower_mnt
;
79 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
80 nd
->path
.dentry
= dentry_save
;
81 nd
->path
.mnt
= vfsmount_save
;
87 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
88 * @ecryptfs_dentry: New file's dentry in ecryptfs
89 * @mode: The mode of the new file
90 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
92 * Creates the underlying file and the eCryptfs inode which will link to
93 * it. It will also update the eCryptfs directory inode to mimic the
94 * stat of the lower directory inode.
96 * Returns zero on success; non-zero on error condition
99 ecryptfs_do_create(struct inode
*directory_inode
,
100 struct dentry
*ecryptfs_dentry
, int mode
,
101 struct nameidata
*nd
)
104 struct dentry
*lower_dentry
;
105 struct dentry
*lower_dir_dentry
;
107 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
108 lower_dir_dentry
= lock_parent(lower_dentry
);
109 if (IS_ERR(lower_dir_dentry
)) {
110 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
112 rc
= PTR_ERR(lower_dir_dentry
);
115 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
116 ecryptfs_dentry
, mode
, nd
);
118 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
119 "rc = [%d]\n", __func__
, rc
);
122 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
123 directory_inode
->i_sb
, 0);
125 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
128 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
129 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
131 unlock_dir(lower_dir_dentry
);
138 * @ecryptfs_dentry: the eCryptfs dentry
140 * This is the code which will grow the file to its correct size.
142 static int grow_file(struct dentry
*ecryptfs_dentry
)
144 struct inode
*ecryptfs_inode
= ecryptfs_dentry
->d_inode
;
145 char zero_virt
[] = { 0x00 };
148 rc
= ecryptfs_write(ecryptfs_inode
, zero_virt
, 0, 1);
149 i_size_write(ecryptfs_inode
, 0);
150 rc
= ecryptfs_write_inode_size_to_metadata(ecryptfs_inode
);
151 ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
.flags
|=
157 * ecryptfs_initialize_file
159 * Cause the file to be changed from a basic empty file to an ecryptfs
160 * file with a header and first data page.
162 * Returns zero on success
164 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
166 struct ecryptfs_crypt_stat
*crypt_stat
=
167 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
170 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
171 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
172 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
175 crypt_stat
->flags
|= ECRYPTFS_NEW_FILE
;
176 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
177 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
179 ecryptfs_printk(KERN_ERR
, "Error creating new file "
180 "context; rc = [%d]\n", rc
);
183 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
184 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
186 printk(KERN_ERR
"%s: Error attempting to initialize "
187 "the persistent file for the dentry with name "
188 "[%s]; rc = [%d]\n", __func__
,
189 ecryptfs_dentry
->d_name
.name
, rc
);
193 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
195 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
198 rc
= grow_file(ecryptfs_dentry
);
200 printk(KERN_ERR
"Error growing file; rc = [%d]\n", rc
);
207 * @dir: The inode of the directory in which to create the file.
208 * @dentry: The eCryptfs dentry
209 * @mode: The mode of the new file.
212 * Creates a new file.
214 * Returns zero on success; non-zero on error condition
217 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
218 int mode
, struct nameidata
*nd
)
222 /* ecryptfs_do_create() calls ecryptfs_interpose() */
223 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
225 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
226 "lower filesystem\n");
229 /* At this point, a file exists on "disk"; we need to make sure
230 * that this on disk file is prepared to be an ecryptfs file */
231 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
237 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
239 int ecryptfs_lookup_and_interpose_lower(struct dentry
*ecryptfs_dentry
,
240 struct dentry
*lower_dentry
,
241 struct inode
*ecryptfs_dir_inode
,
242 struct nameidata
*ecryptfs_nd
)
244 struct dentry
*lower_dir_dentry
;
245 struct vfsmount
*lower_mnt
;
246 struct inode
*lower_inode
;
247 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
248 struct ecryptfs_crypt_stat
*crypt_stat
;
249 char *page_virt
= NULL
;
253 lower_dir_dentry
= lower_dentry
->d_parent
;
254 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
255 ecryptfs_dentry
->d_parent
));
256 lower_inode
= lower_dentry
->d_inode
;
257 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
258 BUG_ON(!atomic_read(&lower_dentry
->d_count
));
259 ecryptfs_set_dentry_private(ecryptfs_dentry
,
260 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
262 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
264 printk(KERN_ERR
"%s: Out of memory whilst attempting "
265 "to allocate ecryptfs_dentry_info struct\n",
269 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
270 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
271 if (!lower_dentry
->d_inode
) {
272 /* We want to add because we couldn't find in lower */
273 d_add(ecryptfs_dentry
, NULL
);
276 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
277 ecryptfs_dir_inode
->i_sb
,
278 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
280 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
284 if (S_ISDIR(lower_inode
->i_mode
))
286 if (S_ISLNK(lower_inode
->i_mode
))
288 if (special_file(lower_inode
->i_mode
))
292 /* Released in this function */
293 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
295 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
300 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
301 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
303 printk(KERN_ERR
"%s: Error attempting to initialize "
304 "the persistent file for the dentry with name "
305 "[%s]; rc = [%d]\n", __func__
,
306 ecryptfs_dentry
->d_name
.name
, rc
);
310 crypt_stat
= &ecryptfs_inode_to_private(
311 ecryptfs_dentry
->d_inode
)->crypt_stat
;
312 /* TODO: lock for crypt_stat comparison */
313 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
314 ecryptfs_set_default_sizes(crypt_stat
);
315 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
316 ecryptfs_dentry
->d_inode
);
318 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
319 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
325 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
327 mount_crypt_stat
= &ecryptfs_superblock_to_private(
328 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
329 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
330 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
331 file_size
= (crypt_stat
->metadata_size
332 + i_size_read(lower_dentry
->d_inode
));
334 file_size
= i_size_read(lower_dentry
->d_inode
);
336 file_size
= get_unaligned_be64(page_virt
);
338 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
340 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
344 d_drop(ecryptfs_dentry
);
351 * @ecryptfs_dir_inode: The eCryptfs directory inode
352 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
353 * @ecryptfs_nd: nameidata; may be NULL
355 * Find a file on disk. If the file does not exist, then we'll add it to the
356 * dentry cache and continue on to read it from the disk.
358 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
359 struct dentry
*ecryptfs_dentry
,
360 struct nameidata
*ecryptfs_nd
)
362 char *encrypted_and_encoded_name
= NULL
;
363 size_t encrypted_and_encoded_name_size
;
364 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
365 struct dentry
*lower_dir_dentry
, *lower_dentry
;
368 ecryptfs_dentry
->d_op
= &ecryptfs_dops
;
369 if ((ecryptfs_dentry
->d_name
.len
== 1
370 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
371 || (ecryptfs_dentry
->d_name
.len
== 2
372 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
375 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
376 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
377 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
379 ecryptfs_dentry
->d_name
.len
);
380 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
381 if (IS_ERR(lower_dentry
)) {
382 rc
= PTR_ERR(lower_dentry
);
383 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
384 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
385 encrypted_and_encoded_name
);
388 if (lower_dentry
->d_inode
)
389 goto lookup_and_interpose
;
390 mount_crypt_stat
= &ecryptfs_superblock_to_private(
391 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
392 if (!(mount_crypt_stat
393 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
394 goto lookup_and_interpose
;
396 rc
= ecryptfs_encrypt_and_encode_filename(
397 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
398 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
399 ecryptfs_dentry
->d_name
.len
);
401 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
402 "filename; rc = [%d]\n", __func__
, rc
);
405 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
406 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
408 encrypted_and_encoded_name_size
- 1);
409 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
410 if (IS_ERR(lower_dentry
)) {
411 rc
= PTR_ERR(lower_dentry
);
412 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
413 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
414 encrypted_and_encoded_name
);
417 lookup_and_interpose
:
418 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
423 d_drop(ecryptfs_dentry
);
425 kfree(encrypted_and_encoded_name
);
429 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
430 struct dentry
*new_dentry
)
432 struct dentry
*lower_old_dentry
;
433 struct dentry
*lower_new_dentry
;
434 struct dentry
*lower_dir_dentry
;
438 file_size_save
= i_size_read(old_dentry
->d_inode
);
439 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
440 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
441 dget(lower_old_dentry
);
442 dget(lower_new_dentry
);
443 lower_dir_dentry
= lock_parent(lower_new_dentry
);
444 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
446 if (rc
|| !lower_new_dentry
->d_inode
)
448 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
451 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
452 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
453 old_dentry
->d_inode
->i_nlink
=
454 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
455 i_size_write(new_dentry
->d_inode
, file_size_save
);
457 unlock_dir(lower_dir_dentry
);
458 dput(lower_new_dentry
);
459 dput(lower_old_dentry
);
463 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
466 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
467 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
468 struct dentry
*lower_dir_dentry
;
471 lower_dir_dentry
= lock_parent(lower_dentry
);
472 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
474 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
477 fsstack_copy_attr_times(dir
, lower_dir_inode
);
478 dentry
->d_inode
->i_nlink
=
479 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
480 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
483 unlock_dir(lower_dir_dentry
);
488 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
492 struct dentry
*lower_dentry
;
493 struct dentry
*lower_dir_dentry
;
494 char *encoded_symname
;
495 size_t encoded_symlen
;
496 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
498 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
500 lower_dir_dentry
= lock_parent(lower_dentry
);
501 mount_crypt_stat
= &ecryptfs_superblock_to_private(
502 dir
->i_sb
)->mount_crypt_stat
;
503 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
506 mount_crypt_stat
, symname
,
510 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
512 kfree(encoded_symname
);
513 if (rc
|| !lower_dentry
->d_inode
)
515 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
518 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
519 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
521 unlock_dir(lower_dir_dentry
);
523 if (!dentry
->d_inode
)
528 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
531 struct dentry
*lower_dentry
;
532 struct dentry
*lower_dir_dentry
;
534 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
535 lower_dir_dentry
= lock_parent(lower_dentry
);
536 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
537 if (rc
|| !lower_dentry
->d_inode
)
539 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
542 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
543 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
544 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
546 unlock_dir(lower_dir_dentry
);
547 if (!dentry
->d_inode
)
552 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
554 struct dentry
*lower_dentry
;
555 struct dentry
*lower_dir_dentry
;
558 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
560 lower_dir_dentry
= lock_parent(lower_dentry
);
562 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
565 d_delete(lower_dentry
);
566 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
567 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
568 unlock_dir(lower_dir_dentry
);
576 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
579 struct dentry
*lower_dentry
;
580 struct dentry
*lower_dir_dentry
;
582 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
583 lower_dir_dentry
= lock_parent(lower_dentry
);
584 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
585 if (rc
|| !lower_dentry
->d_inode
)
587 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
590 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
591 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
593 unlock_dir(lower_dir_dentry
);
594 if (!dentry
->d_inode
)
600 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
601 struct inode
*new_dir
, struct dentry
*new_dentry
)
604 struct dentry
*lower_old_dentry
;
605 struct dentry
*lower_new_dentry
;
606 struct dentry
*lower_old_dir_dentry
;
607 struct dentry
*lower_new_dir_dentry
;
608 struct dentry
*trap
= NULL
;
610 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
611 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
612 dget(lower_old_dentry
);
613 dget(lower_new_dentry
);
614 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
615 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
616 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
617 /* source should not be ancestor of target */
618 if (trap
== lower_old_dentry
) {
622 /* target should not be ancestor of source */
623 if (trap
== lower_new_dentry
) {
627 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
628 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
631 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
632 if (new_dir
!= old_dir
)
633 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
635 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
636 dput(lower_new_dentry
->d_parent
);
637 dput(lower_old_dentry
->d_parent
);
638 dput(lower_new_dentry
);
639 dput(lower_old_dentry
);
643 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
646 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
648 size_t lower_bufsiz
= PATH_MAX
;
652 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
659 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
660 (char __user
*)lower_buf
,
666 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
667 lower_buf
, lower_bufsiz
);
674 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
677 size_t kbufsiz
, copied
;
680 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
683 copied
= min_t(size_t, bufsiz
, kbufsiz
);
684 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
686 fsstack_copy_attr_atime(dentry
->d_inode
,
687 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
692 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
695 int len
= PAGE_SIZE
, rc
;
698 /* Released in ecryptfs_put_link(); only release here on error */
699 buf
= kmalloc(len
, GFP_KERNEL
);
701 buf
= ERR_PTR(-ENOMEM
);
706 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
714 nd_set_link(nd
, buf
);
719 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
721 char *buf
= nd_get_link(nd
);
729 * upper_size_to_lower_size
730 * @crypt_stat: Crypt_stat associated with file
731 * @upper_size: Size of the upper file
733 * Calculate the required size of the lower file based on the
734 * specified size of the upper file. This calculation is based on the
735 * number of headers in the underlying file and the extent size.
737 * Returns Calculated size of the lower file.
740 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
745 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
746 if (upper_size
!= 0) {
749 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
750 if (upper_size
& ~crypt_stat
->extent_mask
)
752 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
759 * @dentry: The ecryptfs layer dentry
760 * @ia: Address of the ecryptfs inode's attributes
761 * @lower_ia: Address of the lower inode's attributes
763 * Function to handle truncations modifying the size of the file. Note
764 * that the file sizes are interpolated. When expanding, we are simply
765 * writing strings of 0's out. When truncating, we truncate the upper
766 * inode and update the lower_ia according to the page index
767 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
768 * the caller must use lower_ia in a call to notify_change() to perform
769 * the truncation of the lower inode.
771 * Returns zero on success; non-zero otherwise
773 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
774 struct iattr
*lower_ia
)
777 struct inode
*inode
= dentry
->d_inode
;
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((ia
->ia_size
== i_size
))) {
784 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
787 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
788 /* Switch on growing or shrinking file */
789 if (ia
->ia_size
> i_size
) {
790 char zero
[] = { 0x00 };
792 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
793 /* Write a single 0 at the last position of the file;
794 * this triggers code that will fill in 0's throughout
795 * the intermediate portion of the previous end of the
796 * file and the new and of the file */
797 rc
= ecryptfs_write(inode
, zero
,
798 (ia
->ia_size
- 1), 1);
799 } else { /* ia->ia_size < i_size_read(inode) */
800 /* We're chopping off all the pages down to the page
801 * in which ia->ia_size is located. Fill in the end of
802 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
803 * PAGE_CACHE_SIZE with zeros. */
804 size_t num_zeros
= (PAGE_CACHE_SIZE
805 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
807 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
808 rc
= simple_setsize(inode
, ia
->ia_size
);
811 lower_ia
->ia_size
= ia
->ia_size
;
812 lower_ia
->ia_valid
|= ATTR_SIZE
;
818 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
823 rc
= ecryptfs_write(inode
, zeros_virt
,
824 ia
->ia_size
, num_zeros
);
827 printk(KERN_ERR
"Error attempting to zero out "
828 "the remainder of the end page on "
829 "reducing truncate; rc = [%d]\n", rc
);
833 simple_setsize(inode
, ia
->ia_size
);
834 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
836 printk(KERN_ERR
"Problem with "
837 "ecryptfs_write_inode_size_to_metadata; "
841 /* We are reducing the size of the ecryptfs file, and need to
842 * know if we need to reduce the size of the lower file. */
843 lower_size_before_truncate
=
844 upper_size_to_lower_size(crypt_stat
, i_size
);
845 lower_size_after_truncate
=
846 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
847 if (lower_size_after_truncate
< lower_size_before_truncate
) {
848 lower_ia
->ia_size
= lower_size_after_truncate
;
849 lower_ia
->ia_valid
|= ATTR_SIZE
;
851 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
859 * @dentry: The ecryptfs layer dentry
860 * @new_length: The length to expand the file to
862 * Simple function that handles the truncation of an eCryptfs inode and
863 * its corresponding lower inode.
865 * Returns zero on success; non-zero otherwise
867 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
869 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
870 struct iattr lower_ia
= { .ia_valid
= 0 };
873 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
874 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
875 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
877 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
878 rc
= notify_change(lower_dentry
, &lower_ia
);
879 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
885 ecryptfs_permission(struct inode
*inode
, int mask
)
887 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
892 * @dentry: dentry handle to the inode to modify
893 * @ia: Structure with flags of what to change and values
895 * Updates the metadata of an inode. If the update is to the size
896 * i.e. truncation, then ecryptfs_truncate will handle the size modification
897 * of both the ecryptfs inode and the lower inode.
899 * All other metadata changes will be passed right to the lower filesystem,
900 * and we will just update our inode to look like the lower.
902 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
905 struct dentry
*lower_dentry
;
906 struct iattr lower_ia
;
908 struct inode
*lower_inode
;
909 struct ecryptfs_crypt_stat
*crypt_stat
;
911 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
912 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
913 ecryptfs_init_crypt_stat(crypt_stat
);
914 inode
= dentry
->d_inode
;
915 lower_inode
= ecryptfs_inode_to_lower(inode
);
916 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
917 mutex_lock(&crypt_stat
->cs_mutex
);
918 if (S_ISDIR(dentry
->d_inode
->i_mode
))
919 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
920 else if (S_ISREG(dentry
->d_inode
->i_mode
)
921 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
922 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
923 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
925 mount_crypt_stat
= &ecryptfs_superblock_to_private(
926 dentry
->d_sb
)->mount_crypt_stat
;
927 rc
= ecryptfs_read_metadata(dentry
);
929 if (!(mount_crypt_stat
->flags
930 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
932 printk(KERN_WARNING
"Either the lower file "
933 "is not in a valid eCryptfs format, "
934 "or the key could not be retrieved. "
935 "Plaintext passthrough mode is not "
936 "enabled; returning -EIO\n");
937 mutex_unlock(&crypt_stat
->cs_mutex
);
941 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
944 mutex_unlock(&crypt_stat
->cs_mutex
);
945 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
946 if (ia
->ia_valid
& ATTR_FILE
)
947 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
948 if (ia
->ia_valid
& ATTR_SIZE
) {
949 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
955 * mode change is for clearing setuid/setgid bits. Allow lower fs
956 * to interpret this in its own way.
958 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
959 lower_ia
.ia_valid
&= ~ATTR_MODE
;
961 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
962 rc
= notify_change(lower_dentry
, &lower_ia
);
963 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
965 fsstack_copy_attr_all(inode
, lower_inode
);
969 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
972 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
975 mount_crypt_stat
= &ecryptfs_superblock_to_private(
976 dentry
->d_sb
)->mount_crypt_stat
;
977 generic_fillattr(dentry
->d_inode
, stat
);
978 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
982 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
985 stat
->size
= targetsiz
;
991 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
994 struct kstat lower_stat
;
997 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
998 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1000 generic_fillattr(dentry
->d_inode
, stat
);
1001 stat
->blocks
= lower_stat
.blocks
;
1007 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1008 size_t size
, int flags
)
1011 struct dentry
*lower_dentry
;
1013 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1014 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1018 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1019 rc
= lower_dentry
->d_inode
->i_op
->setxattr(lower_dentry
, name
, value
,
1021 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1027 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1028 void *value
, size_t size
)
1032 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1036 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1037 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1039 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1045 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1048 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1053 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1056 struct dentry
*lower_dentry
;
1058 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1059 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1063 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1064 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1065 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1070 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1073 struct dentry
*lower_dentry
;
1075 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1076 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1080 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1081 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1082 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1087 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1089 if ((ecryptfs_inode_to_lower(inode
)
1090 == (struct inode
*)candidate_lower_inode
))
1096 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1098 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1102 const struct inode_operations ecryptfs_symlink_iops
= {
1103 .readlink
= ecryptfs_readlink
,
1104 .follow_link
= ecryptfs_follow_link
,
1105 .put_link
= ecryptfs_put_link
,
1106 .permission
= ecryptfs_permission
,
1107 .setattr
= ecryptfs_setattr
,
1108 .getattr
= ecryptfs_getattr_link
,
1109 .setxattr
= ecryptfs_setxattr
,
1110 .getxattr
= ecryptfs_getxattr
,
1111 .listxattr
= ecryptfs_listxattr
,
1112 .removexattr
= ecryptfs_removexattr
1115 const struct inode_operations ecryptfs_dir_iops
= {
1116 .create
= ecryptfs_create
,
1117 .lookup
= ecryptfs_lookup
,
1118 .link
= ecryptfs_link
,
1119 .unlink
= ecryptfs_unlink
,
1120 .symlink
= ecryptfs_symlink
,
1121 .mkdir
= ecryptfs_mkdir
,
1122 .rmdir
= ecryptfs_rmdir
,
1123 .mknod
= ecryptfs_mknod
,
1124 .rename
= ecryptfs_rename
,
1125 .permission
= ecryptfs_permission
,
1126 .setattr
= ecryptfs_setattr
,
1127 .setxattr
= ecryptfs_setxattr
,
1128 .getxattr
= ecryptfs_getxattr
,
1129 .listxattr
= ecryptfs_listxattr
,
1130 .removexattr
= ecryptfs_removexattr
1133 const struct inode_operations ecryptfs_main_iops
= {
1134 .permission
= ecryptfs_permission
,
1135 .setattr
= ecryptfs_setattr
,
1136 .getattr
= ecryptfs_getattr
,
1137 .setxattr
= ecryptfs_setxattr
,
1138 .getxattr
= ecryptfs_getxattr
,
1139 .listxattr
= ecryptfs_listxattr
,
1140 .removexattr
= ecryptfs_removexattr