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 <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry
*lock_parent(struct dentry
*dentry
)
43 dir
= dget_parent(dentry
);
44 mutex_lock_nested(&(dir
->d_inode
->i_mutex
), I_MUTEX_PARENT
);
48 static void unlock_dir(struct dentry
*dir
)
50 mutex_unlock(&dir
->d_inode
->i_mutex
);
55 * ecryptfs_create_underlying_file
56 * @lower_dir_inode: inode of the parent in the lower fs of the new file
57 * @dentry: New file's dentry
58 * @mode: The mode of the new file
59 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
61 * Creates the file in the lower file system.
63 * Returns zero on success; non-zero on error condition
66 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
67 struct dentry
*dentry
, int mode
,
70 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
71 struct vfsmount
*lower_mnt
= ecryptfs_dentry_to_lower_mnt(dentry
);
72 struct dentry
*dentry_save
;
73 struct vfsmount
*vfsmount_save
;
74 unsigned int flags_save
;
78 dentry_save
= nd
->path
.dentry
;
79 vfsmount_save
= nd
->path
.mnt
;
80 flags_save
= nd
->flags
;
81 nd
->path
.dentry
= lower_dentry
;
82 nd
->path
.mnt
= lower_mnt
;
83 nd
->flags
&= ~LOOKUP_OPEN
;
85 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
87 nd
->path
.dentry
= dentry_save
;
88 nd
->path
.mnt
= vfsmount_save
;
89 nd
->flags
= flags_save
;
96 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
97 * @ecryptfs_dentry: New file's dentry in ecryptfs
98 * @mode: The mode of the new file
99 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
101 * Creates the underlying file and the eCryptfs inode which will link to
102 * it. It will also update the eCryptfs directory inode to mimic the
103 * stat of the lower directory inode.
105 * Returns zero on success; non-zero on error condition
108 ecryptfs_do_create(struct inode
*directory_inode
,
109 struct dentry
*ecryptfs_dentry
, int mode
,
110 struct nameidata
*nd
)
113 struct dentry
*lower_dentry
;
114 struct dentry
*lower_dir_dentry
;
116 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
117 lower_dir_dentry
= lock_parent(lower_dentry
);
118 if (IS_ERR(lower_dir_dentry
)) {
119 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
121 rc
= PTR_ERR(lower_dir_dentry
);
124 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
125 ecryptfs_dentry
, mode
, nd
);
127 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
128 "rc = [%d]\n", __func__
, rc
);
131 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
132 directory_inode
->i_sb
, 0);
134 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
137 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
138 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
140 unlock_dir(lower_dir_dentry
);
146 * ecryptfs_initialize_file
148 * Cause the file to be changed from a basic empty file to an ecryptfs
149 * file with a header and first data page.
151 * Returns zero on success
153 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
155 struct ecryptfs_crypt_stat
*crypt_stat
=
156 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
159 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
160 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
161 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
164 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
165 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
167 ecryptfs_printk(KERN_ERR
, "Error creating new file "
168 "context; rc = [%d]\n", rc
);
171 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
);
173 printk(KERN_ERR
"%s: Error attempting to initialize "
174 "the lower file for the dentry with name "
175 "[%s]; rc = [%d]\n", __func__
,
176 ecryptfs_dentry
->d_name
.name
, rc
);
179 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
181 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
182 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
189 * @dir: The inode of the directory in which to create the file.
190 * @dentry: The eCryptfs dentry
191 * @mode: The mode of the new file.
194 * Creates a new file.
196 * Returns zero on success; non-zero on error condition
199 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
200 int mode
, struct nameidata
*nd
)
204 /* ecryptfs_do_create() calls ecryptfs_interpose() */
205 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
207 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
208 "lower filesystem\n");
211 /* At this point, a file exists on "disk"; we need to make sure
212 * that this on disk file is prepared to be an ecryptfs file */
213 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
219 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
221 int ecryptfs_lookup_and_interpose_lower(struct dentry
*ecryptfs_dentry
,
222 struct dentry
*lower_dentry
,
223 struct inode
*ecryptfs_dir_inode
)
225 struct dentry
*lower_dir_dentry
;
226 struct vfsmount
*lower_mnt
;
227 struct inode
*lower_inode
;
228 struct ecryptfs_crypt_stat
*crypt_stat
;
229 char *page_virt
= NULL
;
230 int put_lower
= 0, rc
= 0;
232 lower_dir_dentry
= lower_dentry
->d_parent
;
233 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
234 ecryptfs_dentry
->d_parent
));
235 lower_inode
= lower_dentry
->d_inode
;
236 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
237 BUG_ON(!lower_dentry
->d_count
);
238 ecryptfs_set_dentry_private(ecryptfs_dentry
,
239 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
241 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
243 printk(KERN_ERR
"%s: Out of memory whilst attempting "
244 "to allocate ecryptfs_dentry_info struct\n",
248 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
249 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
250 if (!lower_dentry
->d_inode
) {
251 /* We want to add because we couldn't find in lower */
252 d_add(ecryptfs_dentry
, NULL
);
255 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
256 ecryptfs_dir_inode
->i_sb
,
257 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
259 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
263 if (S_ISDIR(lower_inode
->i_mode
))
265 if (S_ISLNK(lower_inode
->i_mode
))
267 if (special_file(lower_inode
->i_mode
))
269 /* Released in this function */
270 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
272 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
277 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
);
279 printk(KERN_ERR
"%s: Error attempting to initialize "
280 "the lower file for the dentry with name "
281 "[%s]; rc = [%d]\n", __func__
,
282 ecryptfs_dentry
->d_name
.name
, rc
);
286 crypt_stat
= &ecryptfs_inode_to_private(
287 ecryptfs_dentry
->d_inode
)->crypt_stat
;
288 /* TODO: lock for crypt_stat comparison */
289 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
290 ecryptfs_set_default_sizes(crypt_stat
);
291 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
292 ecryptfs_dentry
->d_inode
);
294 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
295 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
301 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
303 ecryptfs_i_size_init(page_virt
, ecryptfs_dentry
->d_inode
);
305 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
310 d_drop(ecryptfs_dentry
);
313 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
319 * @ecryptfs_dir_inode: The eCryptfs directory inode
320 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
321 * @ecryptfs_nd: nameidata; may be NULL
323 * Find a file on disk. If the file does not exist, then we'll add it to the
324 * dentry cache and continue on to read it from the disk.
326 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
327 struct dentry
*ecryptfs_dentry
,
328 struct nameidata
*ecryptfs_nd
)
330 char *encrypted_and_encoded_name
= NULL
;
331 size_t encrypted_and_encoded_name_size
;
332 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
333 struct dentry
*lower_dir_dentry
, *lower_dentry
;
336 if ((ecryptfs_dentry
->d_name
.len
== 1
337 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
338 || (ecryptfs_dentry
->d_name
.len
== 2
339 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
342 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
343 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
344 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
346 ecryptfs_dentry
->d_name
.len
);
347 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
348 if (IS_ERR(lower_dentry
)) {
349 rc
= PTR_ERR(lower_dentry
);
350 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
351 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
352 encrypted_and_encoded_name
);
355 if (lower_dentry
->d_inode
)
356 goto lookup_and_interpose
;
357 mount_crypt_stat
= &ecryptfs_superblock_to_private(
358 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
359 if (!(mount_crypt_stat
360 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
361 goto lookup_and_interpose
;
363 rc
= ecryptfs_encrypt_and_encode_filename(
364 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
365 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
366 ecryptfs_dentry
->d_name
.len
);
368 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
369 "filename; rc = [%d]\n", __func__
, rc
);
372 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
373 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
375 encrypted_and_encoded_name_size
);
376 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
377 if (IS_ERR(lower_dentry
)) {
378 rc
= PTR_ERR(lower_dentry
);
379 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
380 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
381 encrypted_and_encoded_name
);
384 lookup_and_interpose
:
385 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
389 d_drop(ecryptfs_dentry
);
391 kfree(encrypted_and_encoded_name
);
395 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
396 struct dentry
*new_dentry
)
398 struct dentry
*lower_old_dentry
;
399 struct dentry
*lower_new_dentry
;
400 struct dentry
*lower_dir_dentry
;
404 file_size_save
= i_size_read(old_dentry
->d_inode
);
405 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
406 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
407 dget(lower_old_dentry
);
408 dget(lower_new_dentry
);
409 lower_dir_dentry
= lock_parent(lower_new_dentry
);
410 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
412 if (rc
|| !lower_new_dentry
->d_inode
)
414 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
417 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
418 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
419 old_dentry
->d_inode
->i_nlink
=
420 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
421 i_size_write(new_dentry
->d_inode
, file_size_save
);
423 unlock_dir(lower_dir_dentry
);
424 dput(lower_new_dentry
);
425 dput(lower_old_dentry
);
429 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
432 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
433 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
434 struct dentry
*lower_dir_dentry
;
437 lower_dir_dentry
= lock_parent(lower_dentry
);
438 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
440 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
443 fsstack_copy_attr_times(dir
, lower_dir_inode
);
444 dentry
->d_inode
->i_nlink
=
445 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
446 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
449 unlock_dir(lower_dir_dentry
);
454 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
458 struct dentry
*lower_dentry
;
459 struct dentry
*lower_dir_dentry
;
460 char *encoded_symname
;
461 size_t encoded_symlen
;
462 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
464 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
466 lower_dir_dentry
= lock_parent(lower_dentry
);
467 mount_crypt_stat
= &ecryptfs_superblock_to_private(
468 dir
->i_sb
)->mount_crypt_stat
;
469 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
472 mount_crypt_stat
, symname
,
476 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
478 kfree(encoded_symname
);
479 if (rc
|| !lower_dentry
->d_inode
)
481 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
484 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
485 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
487 unlock_dir(lower_dir_dentry
);
489 if (!dentry
->d_inode
)
494 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
497 struct dentry
*lower_dentry
;
498 struct dentry
*lower_dir_dentry
;
500 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
501 lower_dir_dentry
= lock_parent(lower_dentry
);
502 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
503 if (rc
|| !lower_dentry
->d_inode
)
505 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
508 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
509 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
510 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
512 unlock_dir(lower_dir_dentry
);
513 if (!dentry
->d_inode
)
518 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
520 struct dentry
*lower_dentry
;
521 struct dentry
*lower_dir_dentry
;
524 dentry_unhash(dentry
);
526 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
528 lower_dir_dentry
= lock_parent(lower_dentry
);
530 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
532 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
533 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
534 unlock_dir(lower_dir_dentry
);
542 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
545 struct dentry
*lower_dentry
;
546 struct dentry
*lower_dir_dentry
;
548 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
549 lower_dir_dentry
= lock_parent(lower_dentry
);
550 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
551 if (rc
|| !lower_dentry
->d_inode
)
553 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
556 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
557 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
559 unlock_dir(lower_dir_dentry
);
560 if (!dentry
->d_inode
)
566 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
567 struct inode
*new_dir
, struct dentry
*new_dentry
)
570 struct dentry
*lower_old_dentry
;
571 struct dentry
*lower_new_dentry
;
572 struct dentry
*lower_old_dir_dentry
;
573 struct dentry
*lower_new_dir_dentry
;
574 struct dentry
*trap
= NULL
;
576 if (new_dentry
->d_inode
&& S_ISDIR(new_dentry
->d_inode
->i_mode
))
577 dentry_unhash(new_dentry
);
579 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
580 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
581 dget(lower_old_dentry
);
582 dget(lower_new_dentry
);
583 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
584 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
585 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
586 /* source should not be ancestor of target */
587 if (trap
== lower_old_dentry
) {
591 /* target should not be ancestor of source */
592 if (trap
== lower_new_dentry
) {
596 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
597 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
600 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
601 if (new_dir
!= old_dir
)
602 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
604 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
605 dput(lower_new_dir_dentry
);
606 dput(lower_old_dir_dentry
);
607 dput(lower_new_dentry
);
608 dput(lower_old_dentry
);
612 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
615 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
617 size_t lower_bufsiz
= PATH_MAX
;
621 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
628 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
629 (char __user
*)lower_buf
,
635 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
636 lower_buf
, lower_bufsiz
);
643 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
646 size_t kbufsiz
, copied
;
649 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
652 copied
= min_t(size_t, bufsiz
, kbufsiz
);
653 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
655 fsstack_copy_attr_atime(dentry
->d_inode
,
656 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
661 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
664 int len
= PAGE_SIZE
, rc
;
667 /* Released in ecryptfs_put_link(); only release here on error */
668 buf
= kmalloc(len
, GFP_KERNEL
);
670 buf
= ERR_PTR(-ENOMEM
);
675 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
683 nd_set_link(nd
, buf
);
688 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
690 char *buf
= nd_get_link(nd
);
698 * upper_size_to_lower_size
699 * @crypt_stat: Crypt_stat associated with file
700 * @upper_size: Size of the upper file
702 * Calculate the required size of the lower file based on the
703 * specified size of the upper file. This calculation is based on the
704 * number of headers in the underlying file and the extent size.
706 * Returns Calculated size of the lower file.
709 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
714 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
715 if (upper_size
!= 0) {
718 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
719 if (upper_size
& ~crypt_stat
->extent_mask
)
721 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
728 * @dentry: The ecryptfs layer dentry
729 * @ia: Address of the ecryptfs inode's attributes
730 * @lower_ia: Address of the lower inode's attributes
732 * Function to handle truncations modifying the size of the file. Note
733 * that the file sizes are interpolated. When expanding, we are simply
734 * writing strings of 0's out. When truncating, we truncate the upper
735 * inode and update the lower_ia according to the page index
736 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
737 * the caller must use lower_ia in a call to notify_change() to perform
738 * the truncation of the lower inode.
740 * Returns zero on success; non-zero otherwise
742 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
743 struct iattr
*lower_ia
)
746 struct inode
*inode
= dentry
->d_inode
;
747 struct ecryptfs_crypt_stat
*crypt_stat
;
748 loff_t i_size
= i_size_read(inode
);
749 loff_t lower_size_before_truncate
;
750 loff_t lower_size_after_truncate
;
752 if (unlikely((ia
->ia_size
== i_size
))) {
753 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
756 rc
= ecryptfs_get_lower_file(dentry
);
759 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
760 /* Switch on growing or shrinking file */
761 if (ia
->ia_size
> i_size
) {
762 char zero
[] = { 0x00 };
764 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
765 /* Write a single 0 at the last position of the file;
766 * this triggers code that will fill in 0's throughout
767 * the intermediate portion of the previous end of the
768 * file and the new and of the file */
769 rc
= ecryptfs_write(inode
, zero
,
770 (ia
->ia_size
- 1), 1);
771 } else { /* ia->ia_size < i_size_read(inode) */
772 /* We're chopping off all the pages down to the page
773 * in which ia->ia_size is located. Fill in the end of
774 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
775 * PAGE_CACHE_SIZE with zeros. */
776 size_t num_zeros
= (PAGE_CACHE_SIZE
777 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
781 * XXX(truncate) this should really happen at the begginning
782 * of ->setattr. But the code is too messy to that as part
783 * of a larger patch. ecryptfs is also totally missing out
784 * on the inode_change_ok check at the beginning of
785 * ->setattr while would include this.
787 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
791 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
792 truncate_setsize(inode
, ia
->ia_size
);
793 lower_ia
->ia_size
= ia
->ia_size
;
794 lower_ia
->ia_valid
|= ATTR_SIZE
;
800 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
805 rc
= ecryptfs_write(inode
, zeros_virt
,
806 ia
->ia_size
, num_zeros
);
809 printk(KERN_ERR
"Error attempting to zero out "
810 "the remainder of the end page on "
811 "reducing truncate; rc = [%d]\n", rc
);
815 truncate_setsize(inode
, ia
->ia_size
);
816 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
818 printk(KERN_ERR
"Problem with "
819 "ecryptfs_write_inode_size_to_metadata; "
823 /* We are reducing the size of the ecryptfs file, and need to
824 * know if we need to reduce the size of the lower file. */
825 lower_size_before_truncate
=
826 upper_size_to_lower_size(crypt_stat
, i_size
);
827 lower_size_after_truncate
=
828 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
829 if (lower_size_after_truncate
< lower_size_before_truncate
) {
830 lower_ia
->ia_size
= lower_size_after_truncate
;
831 lower_ia
->ia_valid
|= ATTR_SIZE
;
833 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
836 ecryptfs_put_lower_file(inode
);
842 * @dentry: The ecryptfs layer dentry
843 * @new_length: The length to expand the file to
845 * Simple function that handles the truncation of an eCryptfs inode and
846 * its corresponding lower inode.
848 * Returns zero on success; non-zero otherwise
850 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
852 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
853 struct iattr lower_ia
= { .ia_valid
= 0 };
856 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
857 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
858 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
860 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
861 rc
= notify_change(lower_dentry
, &lower_ia
);
862 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
868 ecryptfs_permission(struct inode
*inode
, int mask
, unsigned int flags
)
870 if (flags
& IPERM_FLAG_RCU
)
872 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
877 * @dentry: dentry handle to the inode to modify
878 * @ia: Structure with flags of what to change and values
880 * Updates the metadata of an inode. If the update is to the size
881 * i.e. truncation, then ecryptfs_truncate will handle the size modification
882 * of both the ecryptfs inode and the lower inode.
884 * All other metadata changes will be passed right to the lower filesystem,
885 * and we will just update our inode to look like the lower.
887 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
890 struct dentry
*lower_dentry
;
891 struct iattr lower_ia
;
893 struct inode
*lower_inode
;
894 struct ecryptfs_crypt_stat
*crypt_stat
;
896 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
897 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
898 ecryptfs_init_crypt_stat(crypt_stat
);
899 inode
= dentry
->d_inode
;
900 lower_inode
= ecryptfs_inode_to_lower(inode
);
901 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
902 mutex_lock(&crypt_stat
->cs_mutex
);
903 if (S_ISDIR(dentry
->d_inode
->i_mode
))
904 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
905 else if (S_ISREG(dentry
->d_inode
->i_mode
)
906 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
907 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
908 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
910 mount_crypt_stat
= &ecryptfs_superblock_to_private(
911 dentry
->d_sb
)->mount_crypt_stat
;
912 rc
= ecryptfs_get_lower_file(dentry
);
914 mutex_unlock(&crypt_stat
->cs_mutex
);
917 rc
= ecryptfs_read_metadata(dentry
);
918 ecryptfs_put_lower_file(inode
);
920 if (!(mount_crypt_stat
->flags
921 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
923 printk(KERN_WARNING
"Either the lower file "
924 "is not in a valid eCryptfs format, "
925 "or the key could not be retrieved. "
926 "Plaintext passthrough mode is not "
927 "enabled; returning -EIO\n");
928 mutex_unlock(&crypt_stat
->cs_mutex
);
932 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
933 | ECRYPTFS_ENCRYPTED
);
936 mutex_unlock(&crypt_stat
->cs_mutex
);
937 if (S_ISREG(inode
->i_mode
)) {
938 rc
= filemap_write_and_wait(inode
->i_mapping
);
941 fsstack_copy_attr_all(inode
, lower_inode
);
943 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
944 if (ia
->ia_valid
& ATTR_FILE
)
945 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
946 if (ia
->ia_valid
& ATTR_SIZE
) {
947 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
953 * mode change is for clearing setuid/setgid bits. Allow lower fs
954 * to interpret this in its own way.
956 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
957 lower_ia
.ia_valid
&= ~ATTR_MODE
;
959 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
960 rc
= notify_change(lower_dentry
, &lower_ia
);
961 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
963 fsstack_copy_attr_all(inode
, lower_inode
);
967 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
970 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
973 mount_crypt_stat
= &ecryptfs_superblock_to_private(
974 dentry
->d_sb
)->mount_crypt_stat
;
975 generic_fillattr(dentry
->d_inode
, stat
);
976 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
980 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
983 stat
->size
= targetsiz
;
989 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
992 struct kstat lower_stat
;
995 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
996 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
998 fsstack_copy_attr_all(dentry
->d_inode
,
999 ecryptfs_inode_to_lower(dentry
->d_inode
));
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
) {
1019 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1025 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1026 void *value
, size_t size
)
1030 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1034 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1035 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1037 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1043 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1046 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1051 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1054 struct dentry
*lower_dentry
;
1056 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1057 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1061 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1062 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1063 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1068 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1071 struct dentry
*lower_dentry
;
1073 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1074 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1078 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1079 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1080 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1085 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1087 if ((ecryptfs_inode_to_lower(inode
)
1088 == (struct inode
*)candidate_lower_inode
))
1094 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1096 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1100 const struct inode_operations ecryptfs_symlink_iops
= {
1101 .readlink
= ecryptfs_readlink
,
1102 .follow_link
= ecryptfs_follow_link
,
1103 .put_link
= ecryptfs_put_link
,
1104 .permission
= ecryptfs_permission
,
1105 .setattr
= ecryptfs_setattr
,
1106 .getattr
= ecryptfs_getattr_link
,
1107 .setxattr
= ecryptfs_setxattr
,
1108 .getxattr
= ecryptfs_getxattr
,
1109 .listxattr
= ecryptfs_listxattr
,
1110 .removexattr
= ecryptfs_removexattr
1113 const struct inode_operations ecryptfs_dir_iops
= {
1114 .create
= ecryptfs_create
,
1115 .lookup
= ecryptfs_lookup
,
1116 .link
= ecryptfs_link
,
1117 .unlink
= ecryptfs_unlink
,
1118 .symlink
= ecryptfs_symlink
,
1119 .mkdir
= ecryptfs_mkdir
,
1120 .rmdir
= ecryptfs_rmdir
,
1121 .mknod
= ecryptfs_mknod
,
1122 .rename
= ecryptfs_rename
,
1123 .permission
= ecryptfs_permission
,
1124 .setattr
= ecryptfs_setattr
,
1125 .setxattr
= ecryptfs_setxattr
,
1126 .getxattr
= ecryptfs_getxattr
,
1127 .listxattr
= ecryptfs_listxattr
,
1128 .removexattr
= ecryptfs_removexattr
1131 const struct inode_operations ecryptfs_main_iops
= {
1132 .permission
= ecryptfs_permission
,
1133 .setattr
= ecryptfs_setattr
,
1134 .getattr
= ecryptfs_getattr
,
1135 .setxattr
= ecryptfs_setxattr
,
1136 .getxattr
= ecryptfs_getxattr
,
1137 .listxattr
= ecryptfs_listxattr
,
1138 .removexattr
= ecryptfs_removexattr