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
);
345 d_drop(ecryptfs_dentry
);
351 * ecryptfs_new_lower_dentry
352 * @ename: The name of the new dentry.
353 * @lower_dir_dentry: Parent directory of the new dentry.
354 * @nd: nameidata from last lookup.
356 * Create a new dentry or get it from lower parent dir.
358 static struct dentry
*
359 ecryptfs_new_lower_dentry(struct qstr
*name
, struct dentry
*lower_dir_dentry
,
360 struct nameidata
*nd
)
362 struct dentry
*new_dentry
;
364 struct inode
*lower_dir_inode
;
366 lower_dir_inode
= lower_dir_dentry
->d_inode
;
368 tmp
= d_alloc(lower_dir_dentry
, name
);
370 return ERR_PTR(-ENOMEM
);
372 mutex_lock(&lower_dir_inode
->i_mutex
);
373 new_dentry
= lower_dir_inode
->i_op
->lookup(lower_dir_inode
, tmp
, nd
);
374 mutex_unlock(&lower_dir_inode
->i_mutex
);
386 * ecryptfs_lookup_one_lower
387 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
388 * @lower_dir_dentry: lower parent directory
390 * Get the lower dentry from vfs. If lower dentry does not exist yet,
393 static struct dentry
*
394 ecryptfs_lookup_one_lower(struct dentry
*ecryptfs_dentry
,
395 struct dentry
*lower_dir_dentry
)
398 struct vfsmount
*lower_mnt
;
402 name
= &ecryptfs_dentry
->d_name
;
403 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
404 ecryptfs_dentry
->d_parent
));
405 err
= vfs_path_lookup(lower_dir_dentry
, lower_mnt
, name
->name
, 0, &nd
);
409 /* we dont need the mount */
411 return nd
.path
.dentry
;
416 /* create a new lower dentry */
417 return ecryptfs_new_lower_dentry(name
, lower_dir_dentry
, &nd
);
422 * @ecryptfs_dir_inode: The eCryptfs directory inode
423 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
424 * @ecryptfs_nd: nameidata; may be NULL
426 * Find a file on disk. If the file does not exist, then we'll add it to the
427 * dentry cache and continue on to read it from the disk.
429 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
430 struct dentry
*ecryptfs_dentry
,
431 struct nameidata
*ecryptfs_nd
)
433 char *encrypted_and_encoded_name
= NULL
;
434 size_t encrypted_and_encoded_name_size
;
435 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
436 struct dentry
*lower_dir_dentry
, *lower_dentry
;
439 ecryptfs_dentry
->d_op
= &ecryptfs_dops
;
440 if ((ecryptfs_dentry
->d_name
.len
== 1
441 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
442 || (ecryptfs_dentry
->d_name
.len
== 2
443 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
446 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
448 lower_dentry
= ecryptfs_lookup_one_lower(ecryptfs_dentry
,
450 if (IS_ERR(lower_dentry
)) {
451 rc
= PTR_ERR(lower_dentry
);
452 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_lower() returned "
453 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
454 encrypted_and_encoded_name
);
457 if (lower_dentry
->d_inode
)
458 goto lookup_and_interpose
;
459 mount_crypt_stat
= &ecryptfs_superblock_to_private(
460 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
461 if (!(mount_crypt_stat
462 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
463 goto lookup_and_interpose
;
465 rc
= ecryptfs_encrypt_and_encode_filename(
466 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
467 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
468 ecryptfs_dentry
->d_name
.len
);
470 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
471 "filename; rc = [%d]\n", __func__
, rc
);
474 lower_dentry
= ecryptfs_lookup_one_lower(ecryptfs_dentry
,
476 if (IS_ERR(lower_dentry
)) {
477 rc
= PTR_ERR(lower_dentry
);
478 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_lower() returned "
479 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
480 encrypted_and_encoded_name
);
483 lookup_and_interpose
:
484 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
489 d_drop(ecryptfs_dentry
);
491 kfree(encrypted_and_encoded_name
);
495 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
496 struct dentry
*new_dentry
)
498 struct dentry
*lower_old_dentry
;
499 struct dentry
*lower_new_dentry
;
500 struct dentry
*lower_dir_dentry
;
504 file_size_save
= i_size_read(old_dentry
->d_inode
);
505 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
506 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
507 dget(lower_old_dentry
);
508 dget(lower_new_dentry
);
509 lower_dir_dentry
= lock_parent(lower_new_dentry
);
510 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
512 if (rc
|| !lower_new_dentry
->d_inode
)
514 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
517 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
518 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
519 old_dentry
->d_inode
->i_nlink
=
520 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
521 i_size_write(new_dentry
->d_inode
, file_size_save
);
523 unlock_dir(lower_dir_dentry
);
524 dput(lower_new_dentry
);
525 dput(lower_old_dentry
);
529 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
532 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
533 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
534 struct dentry
*lower_dir_dentry
;
537 lower_dir_dentry
= lock_parent(lower_dentry
);
538 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
540 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
543 fsstack_copy_attr_times(dir
, lower_dir_inode
);
544 dentry
->d_inode
->i_nlink
=
545 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
546 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
549 unlock_dir(lower_dir_dentry
);
554 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
558 struct dentry
*lower_dentry
;
559 struct dentry
*lower_dir_dentry
;
560 char *encoded_symname
;
561 size_t encoded_symlen
;
562 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
564 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
566 lower_dir_dentry
= lock_parent(lower_dentry
);
567 mount_crypt_stat
= &ecryptfs_superblock_to_private(
568 dir
->i_sb
)->mount_crypt_stat
;
569 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
572 mount_crypt_stat
, symname
,
576 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
578 kfree(encoded_symname
);
579 if (rc
|| !lower_dentry
->d_inode
)
581 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
584 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
585 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
587 unlock_dir(lower_dir_dentry
);
589 if (!dentry
->d_inode
)
594 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
597 struct dentry
*lower_dentry
;
598 struct dentry
*lower_dir_dentry
;
600 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
601 lower_dir_dentry
= lock_parent(lower_dentry
);
602 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
603 if (rc
|| !lower_dentry
->d_inode
)
605 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
608 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
609 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
610 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
612 unlock_dir(lower_dir_dentry
);
613 if (!dentry
->d_inode
)
618 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
620 struct dentry
*lower_dentry
;
621 struct dentry
*lower_dir_dentry
;
624 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
626 lower_dir_dentry
= lock_parent(lower_dentry
);
628 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
631 d_delete(lower_dentry
);
632 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
633 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
634 unlock_dir(lower_dir_dentry
);
642 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
645 struct dentry
*lower_dentry
;
646 struct dentry
*lower_dir_dentry
;
648 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
649 lower_dir_dentry
= lock_parent(lower_dentry
);
650 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
651 if (rc
|| !lower_dentry
->d_inode
)
653 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
656 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
657 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
659 unlock_dir(lower_dir_dentry
);
660 if (!dentry
->d_inode
)
666 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
667 struct inode
*new_dir
, struct dentry
*new_dentry
)
670 struct dentry
*lower_old_dentry
;
671 struct dentry
*lower_new_dentry
;
672 struct dentry
*lower_old_dir_dentry
;
673 struct dentry
*lower_new_dir_dentry
;
674 struct dentry
*trap
= NULL
;
676 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
677 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
678 dget(lower_old_dentry
);
679 dget(lower_new_dentry
);
680 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
681 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
682 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
683 /* source should not be ancestor of target */
684 if (trap
== lower_old_dentry
) {
688 /* target should not be ancestor of source */
689 if (trap
== lower_new_dentry
) {
693 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
694 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
697 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
698 if (new_dir
!= old_dir
)
699 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
701 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
702 dput(lower_new_dentry
->d_parent
);
703 dput(lower_old_dentry
->d_parent
);
704 dput(lower_new_dentry
);
705 dput(lower_old_dentry
);
709 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
712 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
714 size_t lower_bufsiz
= PATH_MAX
;
718 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
725 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
726 (char __user
*)lower_buf
,
732 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
733 lower_buf
, lower_bufsiz
);
740 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
743 size_t kbufsiz
, copied
;
746 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
749 copied
= min_t(size_t, bufsiz
, kbufsiz
);
750 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
752 fsstack_copy_attr_atime(dentry
->d_inode
,
753 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
758 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
761 int len
= PAGE_SIZE
, rc
;
764 /* Released in ecryptfs_put_link(); only release here on error */
765 buf
= kmalloc(len
, GFP_KERNEL
);
767 buf
= ERR_PTR(-ENOMEM
);
772 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
780 nd_set_link(nd
, buf
);
785 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
787 char *buf
= nd_get_link(nd
);
795 * upper_size_to_lower_size
796 * @crypt_stat: Crypt_stat associated with file
797 * @upper_size: Size of the upper file
799 * Calculate the required size of the lower file based on the
800 * specified size of the upper file. This calculation is based on the
801 * number of headers in the underlying file and the extent size.
803 * Returns Calculated size of the lower file.
806 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
811 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
812 if (upper_size
!= 0) {
815 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
816 if (upper_size
& ~crypt_stat
->extent_mask
)
818 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
825 * @dentry: The ecryptfs layer dentry
826 * @ia: Address of the ecryptfs inode's attributes
827 * @lower_ia: Address of the lower inode's attributes
829 * Function to handle truncations modifying the size of the file. Note
830 * that the file sizes are interpolated. When expanding, we are simply
831 * writing strings of 0's out. When truncating, we truncate the upper
832 * inode and update the lower_ia according to the page index
833 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
834 * the caller must use lower_ia in a call to notify_change() to perform
835 * the truncation of the lower inode.
837 * Returns zero on success; non-zero otherwise
839 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
840 struct iattr
*lower_ia
)
843 struct inode
*inode
= dentry
->d_inode
;
844 struct ecryptfs_crypt_stat
*crypt_stat
;
845 loff_t i_size
= i_size_read(inode
);
846 loff_t lower_size_before_truncate
;
847 loff_t lower_size_after_truncate
;
849 if (unlikely((ia
->ia_size
== i_size
))) {
850 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
853 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
854 /* Switch on growing or shrinking file */
855 if (ia
->ia_size
> i_size
) {
856 char zero
[] = { 0x00 };
858 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
859 /* Write a single 0 at the last position of the file;
860 * this triggers code that will fill in 0's throughout
861 * the intermediate portion of the previous end of the
862 * file and the new and of the file */
863 rc
= ecryptfs_write(inode
, zero
,
864 (ia
->ia_size
- 1), 1);
865 } else { /* ia->ia_size < i_size_read(inode) */
866 /* We're chopping off all the pages down to the page
867 * in which ia->ia_size is located. Fill in the end of
868 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
869 * PAGE_CACHE_SIZE with zeros. */
870 size_t num_zeros
= (PAGE_CACHE_SIZE
871 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
875 * XXX(truncate) this should really happen at the begginning
876 * of ->setattr. But the code is too messy to that as part
877 * of a larger patch. ecryptfs is also totally missing out
878 * on the inode_change_ok check at the beginning of
879 * ->setattr while would include this.
881 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
885 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
886 truncate_setsize(inode
, ia
->ia_size
);
887 lower_ia
->ia_size
= ia
->ia_size
;
888 lower_ia
->ia_valid
|= ATTR_SIZE
;
894 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
899 rc
= ecryptfs_write(inode
, zeros_virt
,
900 ia
->ia_size
, num_zeros
);
903 printk(KERN_ERR
"Error attempting to zero out "
904 "the remainder of the end page on "
905 "reducing truncate; rc = [%d]\n", rc
);
909 truncate_setsize(inode
, ia
->ia_size
);
910 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
912 printk(KERN_ERR
"Problem with "
913 "ecryptfs_write_inode_size_to_metadata; "
917 /* We are reducing the size of the ecryptfs file, and need to
918 * know if we need to reduce the size of the lower file. */
919 lower_size_before_truncate
=
920 upper_size_to_lower_size(crypt_stat
, i_size
);
921 lower_size_after_truncate
=
922 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
923 if (lower_size_after_truncate
< lower_size_before_truncate
) {
924 lower_ia
->ia_size
= lower_size_after_truncate
;
925 lower_ia
->ia_valid
|= ATTR_SIZE
;
927 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
935 * @dentry: The ecryptfs layer dentry
936 * @new_length: The length to expand the file to
938 * Simple function that handles the truncation of an eCryptfs inode and
939 * its corresponding lower inode.
941 * Returns zero on success; non-zero otherwise
943 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
945 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
946 struct iattr lower_ia
= { .ia_valid
= 0 };
949 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
950 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
951 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
953 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
954 rc
= notify_change(lower_dentry
, &lower_ia
);
955 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
961 ecryptfs_permission(struct inode
*inode
, int mask
)
963 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
968 * @dentry: dentry handle to the inode to modify
969 * @ia: Structure with flags of what to change and values
971 * Updates the metadata of an inode. If the update is to the size
972 * i.e. truncation, then ecryptfs_truncate will handle the size modification
973 * of both the ecryptfs inode and the lower inode.
975 * All other metadata changes will be passed right to the lower filesystem,
976 * and we will just update our inode to look like the lower.
978 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
981 struct dentry
*lower_dentry
;
982 struct iattr lower_ia
;
984 struct inode
*lower_inode
;
985 struct ecryptfs_crypt_stat
*crypt_stat
;
987 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
988 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
989 ecryptfs_init_crypt_stat(crypt_stat
);
990 inode
= dentry
->d_inode
;
991 lower_inode
= ecryptfs_inode_to_lower(inode
);
992 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
993 mutex_lock(&crypt_stat
->cs_mutex
);
994 if (S_ISDIR(dentry
->d_inode
->i_mode
))
995 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
996 else if (S_ISREG(dentry
->d_inode
->i_mode
)
997 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
998 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
999 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1001 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1002 dentry
->d_sb
)->mount_crypt_stat
;
1003 rc
= ecryptfs_read_metadata(dentry
);
1005 if (!(mount_crypt_stat
->flags
1006 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
1008 printk(KERN_WARNING
"Either the lower file "
1009 "is not in a valid eCryptfs format, "
1010 "or the key could not be retrieved. "
1011 "Plaintext passthrough mode is not "
1012 "enabled; returning -EIO\n");
1013 mutex_unlock(&crypt_stat
->cs_mutex
);
1017 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
1020 mutex_unlock(&crypt_stat
->cs_mutex
);
1021 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
1022 if (ia
->ia_valid
& ATTR_FILE
)
1023 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
1024 if (ia
->ia_valid
& ATTR_SIZE
) {
1025 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1031 * mode change is for clearing setuid/setgid bits. Allow lower fs
1032 * to interpret this in its own way.
1034 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1035 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1037 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1038 rc
= notify_change(lower_dentry
, &lower_ia
);
1039 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1041 fsstack_copy_attr_all(inode
, lower_inode
);
1045 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1048 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1051 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1052 dentry
->d_sb
)->mount_crypt_stat
;
1053 generic_fillattr(dentry
->d_inode
, stat
);
1054 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1058 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1061 stat
->size
= targetsiz
;
1067 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1070 struct kstat lower_stat
;
1073 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1074 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1076 generic_fillattr(dentry
->d_inode
, stat
);
1077 stat
->blocks
= lower_stat
.blocks
;
1083 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1084 size_t size
, int flags
)
1087 struct dentry
*lower_dentry
;
1089 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1090 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1094 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1095 rc
= lower_dentry
->d_inode
->i_op
->setxattr(lower_dentry
, name
, value
,
1097 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1103 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1104 void *value
, size_t size
)
1108 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1112 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1113 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1115 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1121 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1124 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1129 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1132 struct dentry
*lower_dentry
;
1134 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1135 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1139 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1140 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1141 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1146 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1149 struct dentry
*lower_dentry
;
1151 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1152 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1156 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1157 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1158 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1163 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1165 if ((ecryptfs_inode_to_lower(inode
)
1166 == (struct inode
*)candidate_lower_inode
))
1172 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1174 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1178 const struct inode_operations ecryptfs_symlink_iops
= {
1179 .readlink
= ecryptfs_readlink
,
1180 .follow_link
= ecryptfs_follow_link
,
1181 .put_link
= ecryptfs_put_link
,
1182 .permission
= ecryptfs_permission
,
1183 .setattr
= ecryptfs_setattr
,
1184 .getattr
= ecryptfs_getattr_link
,
1185 .setxattr
= ecryptfs_setxattr
,
1186 .getxattr
= ecryptfs_getxattr
,
1187 .listxattr
= ecryptfs_listxattr
,
1188 .removexattr
= ecryptfs_removexattr
1191 const struct inode_operations ecryptfs_dir_iops
= {
1192 .create
= ecryptfs_create
,
1193 .lookup
= ecryptfs_lookup
,
1194 .link
= ecryptfs_link
,
1195 .unlink
= ecryptfs_unlink
,
1196 .symlink
= ecryptfs_symlink
,
1197 .mkdir
= ecryptfs_mkdir
,
1198 .rmdir
= ecryptfs_rmdir
,
1199 .mknod
= ecryptfs_mknod
,
1200 .rename
= ecryptfs_rename
,
1201 .permission
= ecryptfs_permission
,
1202 .setattr
= ecryptfs_setattr
,
1203 .setxattr
= ecryptfs_setxattr
,
1204 .getxattr
= ecryptfs_getxattr
,
1205 .listxattr
= ecryptfs_listxattr
,
1206 .removexattr
= ecryptfs_removexattr
1209 const struct inode_operations ecryptfs_main_iops
= {
1210 .permission
= ecryptfs_permission
,
1211 .setattr
= ecryptfs_setattr
,
1212 .getattr
= ecryptfs_getattr
,
1213 .setxattr
= ecryptfs_setxattr
,
1214 .getxattr
= ecryptfs_getxattr
,
1215 .listxattr
= ecryptfs_listxattr
,
1216 .removexattr
= ecryptfs_removexattr