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
);
54 static int ecryptfs_inode_test(struct inode
*inode
, void *lower_inode
)
56 if (ecryptfs_inode_to_lower(inode
) == (struct inode
*)lower_inode
)
61 static int ecryptfs_inode_set(struct inode
*inode
, void *opaque
)
63 struct inode
*lower_inode
= opaque
;
65 ecryptfs_set_inode_lower(inode
, lower_inode
);
66 fsstack_copy_attr_all(inode
, lower_inode
);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode
, lower_inode
);
69 inode
->i_ino
= lower_inode
->i_ino
;
71 inode
->i_mapping
->a_ops
= &ecryptfs_aops
;
72 inode
->i_mapping
->backing_dev_info
= inode
->i_sb
->s_bdi
;
74 if (S_ISLNK(inode
->i_mode
))
75 inode
->i_op
= &ecryptfs_symlink_iops
;
76 else if (S_ISDIR(inode
->i_mode
))
77 inode
->i_op
= &ecryptfs_dir_iops
;
79 inode
->i_op
= &ecryptfs_main_iops
;
81 if (S_ISDIR(inode
->i_mode
))
82 inode
->i_fop
= &ecryptfs_dir_fops
;
83 else if (special_file(inode
->i_mode
))
84 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
86 inode
->i_fop
= &ecryptfs_main_fops
;
91 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
92 struct super_block
*sb
)
96 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
97 return ERR_PTR(-EXDEV
);
98 if (!igrab(lower_inode
))
99 return ERR_PTR(-ESTALE
);
100 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
101 ecryptfs_inode_test
, ecryptfs_inode_set
,
105 return ERR_PTR(-EACCES
);
107 if (!(inode
->i_state
& I_NEW
))
113 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
114 struct super_block
*sb
)
116 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
118 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
119 unlock_new_inode(inode
);
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
130 * Interposes upper and lower dentries.
132 * Returns zero on success; non-zero otherwise
134 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
135 struct dentry
*dentry
, struct super_block
*sb
)
137 struct inode
*inode
= ecryptfs_get_inode(lower_dentry
->d_inode
, sb
);
140 return PTR_ERR(inode
);
141 d_instantiate(dentry
, inode
);
148 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
149 * @ecryptfs_dentry: New file's dentry in ecryptfs
150 * @mode: The mode of the new file
151 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
153 * Creates the underlying file and the eCryptfs inode which will link to
154 * it. It will also update the eCryptfs directory inode to mimic the
155 * stat of the lower directory inode.
157 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
159 static struct inode
*
160 ecryptfs_do_create(struct inode
*directory_inode
,
161 struct dentry
*ecryptfs_dentry
, umode_t mode
)
164 struct dentry
*lower_dentry
;
165 struct dentry
*lower_dir_dentry
;
168 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
169 lower_dir_dentry
= lock_parent(lower_dentry
);
170 if (IS_ERR(lower_dir_dentry
)) {
171 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
173 inode
= ERR_CAST(lower_dir_dentry
);
176 rc
= vfs_create(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, true);
178 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
179 "rc = [%d]\n", __func__
, rc
);
183 inode
= __ecryptfs_get_inode(lower_dentry
->d_inode
,
184 directory_inode
->i_sb
);
187 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
188 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
190 unlock_dir(lower_dir_dentry
);
196 * ecryptfs_initialize_file
198 * Cause the file to be changed from a basic empty file to an ecryptfs
199 * file with a header and first data page.
201 * Returns zero on success
203 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
204 struct inode
*ecryptfs_inode
)
206 struct ecryptfs_crypt_stat
*crypt_stat
=
207 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
210 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
211 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
212 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
215 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
216 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
218 ecryptfs_printk(KERN_ERR
, "Error creating new file "
219 "context; rc = [%d]\n", rc
);
222 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
224 printk(KERN_ERR
"%s: Error attempting to initialize "
225 "the lower file for the dentry with name "
226 "[%s]; rc = [%d]\n", __func__
,
227 ecryptfs_dentry
->d_name
.name
, rc
);
230 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
232 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
233 ecryptfs_put_lower_file(ecryptfs_inode
);
240 * @dir: The inode of the directory in which to create the file.
241 * @dentry: The eCryptfs dentry
242 * @mode: The mode of the new file.
244 * Creates a new file.
246 * Returns zero on success; non-zero on error condition
249 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
250 umode_t mode
, bool excl
)
252 struct inode
*ecryptfs_inode
;
255 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
257 if (unlikely(IS_ERR(ecryptfs_inode
))) {
258 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
259 "lower filesystem\n");
260 rc
= PTR_ERR(ecryptfs_inode
);
263 /* At this point, a file exists on "disk"; we need to make sure
264 * that this on disk file is prepared to be an ecryptfs file */
265 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
267 drop_nlink(ecryptfs_inode
);
268 unlock_new_inode(ecryptfs_inode
);
269 iput(ecryptfs_inode
);
272 unlock_new_inode(ecryptfs_inode
);
273 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
278 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
280 struct ecryptfs_crypt_stat
*crypt_stat
;
283 rc
= ecryptfs_get_lower_file(dentry
, inode
);
285 printk(KERN_ERR
"%s: Error attempting to initialize "
286 "the lower file for the dentry with name "
287 "[%s]; rc = [%d]\n", __func__
,
288 dentry
->d_name
.name
, rc
);
292 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
293 /* TODO: lock for crypt_stat comparison */
294 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
295 ecryptfs_set_default_sizes(crypt_stat
);
297 rc
= ecryptfs_read_and_validate_header_region(inode
);
298 ecryptfs_put_lower_file(inode
);
300 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
302 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
305 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
310 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
312 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
313 struct dentry
*lower_dentry
,
314 struct inode
*dir_inode
)
316 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
317 struct ecryptfs_dentry_info
*dentry_info
;
318 struct vfsmount
*lower_mnt
;
321 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
322 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
323 BUG_ON(!lower_dentry
->d_count
);
325 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
326 ecryptfs_set_dentry_private(dentry
, dentry_info
);
328 printk(KERN_ERR
"%s: Out of memory whilst attempting "
329 "to allocate ecryptfs_dentry_info struct\n",
336 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
337 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
339 if (!lower_dentry
->d_inode
) {
340 /* We want to add because we couldn't find in lower */
344 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
346 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
347 __func__
, PTR_ERR(inode
));
348 return PTR_ERR(inode
);
350 if (S_ISREG(inode
->i_mode
)) {
351 rc
= ecryptfs_i_size_read(dentry
, inode
);
353 make_bad_inode(inode
);
358 if (inode
->i_state
& I_NEW
)
359 unlock_new_inode(inode
);
360 d_add(dentry
, inode
);
367 * @ecryptfs_dir_inode: The eCryptfs directory inode
368 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
369 * @ecryptfs_nd: nameidata; may be NULL
371 * Find a file on disk. If the file does not exist, then we'll add it to the
372 * dentry cache and continue on to read it from the disk.
374 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
375 struct dentry
*ecryptfs_dentry
,
378 char *encrypted_and_encoded_name
= NULL
;
379 size_t encrypted_and_encoded_name_size
;
380 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
381 struct dentry
*lower_dir_dentry
, *lower_dentry
;
384 if ((ecryptfs_dentry
->d_name
.len
== 1
385 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
386 || (ecryptfs_dentry
->d_name
.len
== 2
387 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
390 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
391 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
392 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
394 ecryptfs_dentry
->d_name
.len
);
395 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
396 if (IS_ERR(lower_dentry
)) {
397 rc
= PTR_ERR(lower_dentry
);
398 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
399 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
400 encrypted_and_encoded_name
);
403 if (lower_dentry
->d_inode
)
405 mount_crypt_stat
= &ecryptfs_superblock_to_private(
406 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
407 if (!(mount_crypt_stat
408 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
411 rc
= ecryptfs_encrypt_and_encode_filename(
412 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
413 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
414 ecryptfs_dentry
->d_name
.len
);
416 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
417 "filename; rc = [%d]\n", __func__
, rc
);
420 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
421 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
423 encrypted_and_encoded_name_size
);
424 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
425 if (IS_ERR(lower_dentry
)) {
426 rc
= PTR_ERR(lower_dentry
);
427 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
428 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
429 encrypted_and_encoded_name
);
433 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
437 d_drop(ecryptfs_dentry
);
439 kfree(encrypted_and_encoded_name
);
443 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
444 struct dentry
*new_dentry
)
446 struct dentry
*lower_old_dentry
;
447 struct dentry
*lower_new_dentry
;
448 struct dentry
*lower_dir_dentry
;
452 file_size_save
= i_size_read(old_dentry
->d_inode
);
453 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
454 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
455 dget(lower_old_dentry
);
456 dget(lower_new_dentry
);
457 lower_dir_dentry
= lock_parent(lower_new_dentry
);
458 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
460 if (rc
|| !lower_new_dentry
->d_inode
)
462 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
465 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
466 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
467 set_nlink(old_dentry
->d_inode
,
468 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
);
469 i_size_write(new_dentry
->d_inode
, file_size_save
);
471 unlock_dir(lower_dir_dentry
);
472 dput(lower_new_dentry
);
473 dput(lower_old_dentry
);
477 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
480 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
481 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
482 struct dentry
*lower_dir_dentry
;
485 lower_dir_dentry
= lock_parent(lower_dentry
);
486 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
488 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
491 fsstack_copy_attr_times(dir
, lower_dir_inode
);
492 set_nlink(dentry
->d_inode
,
493 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
);
494 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
497 unlock_dir(lower_dir_dentry
);
502 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
506 struct dentry
*lower_dentry
;
507 struct dentry
*lower_dir_dentry
;
508 char *encoded_symname
;
509 size_t encoded_symlen
;
510 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
512 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
514 lower_dir_dentry
= lock_parent(lower_dentry
);
515 mount_crypt_stat
= &ecryptfs_superblock_to_private(
516 dir
->i_sb
)->mount_crypt_stat
;
517 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
520 mount_crypt_stat
, symname
,
524 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
526 kfree(encoded_symname
);
527 if (rc
|| !lower_dentry
->d_inode
)
529 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
532 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
533 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
535 unlock_dir(lower_dir_dentry
);
537 if (!dentry
->d_inode
)
542 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
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_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
551 if (rc
|| !lower_dentry
->d_inode
)
553 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
556 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
557 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
558 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
560 unlock_dir(lower_dir_dentry
);
561 if (!dentry
->d_inode
)
566 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
568 struct dentry
*lower_dentry
;
569 struct dentry
*lower_dir_dentry
;
572 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
574 lower_dir_dentry
= lock_parent(lower_dentry
);
576 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
578 if (!rc
&& dentry
->d_inode
)
579 clear_nlink(dentry
->d_inode
);
580 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
581 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
582 unlock_dir(lower_dir_dentry
);
590 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
593 struct dentry
*lower_dentry
;
594 struct dentry
*lower_dir_dentry
;
596 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
597 lower_dir_dentry
= lock_parent(lower_dentry
);
598 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
599 if (rc
|| !lower_dentry
->d_inode
)
601 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
604 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
605 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
607 unlock_dir(lower_dir_dentry
);
608 if (!dentry
->d_inode
)
614 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
615 struct inode
*new_dir
, struct dentry
*new_dentry
)
618 struct dentry
*lower_old_dentry
;
619 struct dentry
*lower_new_dentry
;
620 struct dentry
*lower_old_dir_dentry
;
621 struct dentry
*lower_new_dir_dentry
;
622 struct dentry
*trap
= NULL
;
624 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
625 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
626 dget(lower_old_dentry
);
627 dget(lower_new_dentry
);
628 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
629 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
630 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
631 /* source should not be ancestor of target */
632 if (trap
== lower_old_dentry
) {
636 /* target should not be ancestor of source */
637 if (trap
== lower_new_dentry
) {
641 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
642 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
645 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
646 if (new_dir
!= old_dir
)
647 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
649 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
650 dput(lower_new_dir_dentry
);
651 dput(lower_old_dir_dentry
);
652 dput(lower_new_dentry
);
653 dput(lower_old_dentry
);
657 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
660 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
665 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
672 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
673 (char __user
*)lower_buf
,
678 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
685 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
688 size_t len
= PATH_MAX
;
691 rc
= ecryptfs_readlink_lower(dentry
, &buf
, &len
);
694 fsstack_copy_attr_atime(dentry
->d_inode
,
695 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
698 nd_set_link(nd
, buf
);
703 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
705 char *buf
= nd_get_link(nd
);
713 * upper_size_to_lower_size
714 * @crypt_stat: Crypt_stat associated with file
715 * @upper_size: Size of the upper file
717 * Calculate the required size of the lower file based on the
718 * specified size of the upper file. This calculation is based on the
719 * number of headers in the underlying file and the extent size.
721 * Returns Calculated size of the lower file.
724 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
729 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
730 if (upper_size
!= 0) {
733 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
734 if (upper_size
& ~crypt_stat
->extent_mask
)
736 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
743 * @dentry: The ecryptfs layer dentry
744 * @ia: Address of the ecryptfs inode's attributes
745 * @lower_ia: Address of the lower inode's attributes
747 * Function to handle truncations modifying the size of the file. Note
748 * that the file sizes are interpolated. When expanding, we are simply
749 * writing strings of 0's out. When truncating, we truncate the upper
750 * inode and update the lower_ia according to the page index
751 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
752 * the caller must use lower_ia in a call to notify_change() to perform
753 * the truncation of the lower inode.
755 * Returns zero on success; non-zero otherwise
757 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
758 struct iattr
*lower_ia
)
761 struct inode
*inode
= dentry
->d_inode
;
762 struct ecryptfs_crypt_stat
*crypt_stat
;
763 loff_t i_size
= i_size_read(inode
);
764 loff_t lower_size_before_truncate
;
765 loff_t lower_size_after_truncate
;
767 if (unlikely((ia
->ia_size
== i_size
))) {
768 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
771 rc
= ecryptfs_get_lower_file(dentry
, inode
);
774 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
775 /* Switch on growing or shrinking file */
776 if (ia
->ia_size
> i_size
) {
777 char zero
[] = { 0x00 };
779 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
780 /* Write a single 0 at the last position of the file;
781 * this triggers code that will fill in 0's throughout
782 * the intermediate portion of the previous end of the
783 * file and the new and of the file */
784 rc
= ecryptfs_write(inode
, zero
,
785 (ia
->ia_size
- 1), 1);
786 } else { /* ia->ia_size < i_size_read(inode) */
787 /* We're chopping off all the pages down to the page
788 * in which ia->ia_size is located. Fill in the end of
789 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
790 * PAGE_CACHE_SIZE with zeros. */
791 size_t num_zeros
= (PAGE_CACHE_SIZE
792 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
794 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
795 truncate_setsize(inode
, ia
->ia_size
);
796 lower_ia
->ia_size
= ia
->ia_size
;
797 lower_ia
->ia_valid
|= ATTR_SIZE
;
803 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
808 rc
= ecryptfs_write(inode
, zeros_virt
,
809 ia
->ia_size
, num_zeros
);
812 printk(KERN_ERR
"Error attempting to zero out "
813 "the remainder of the end page on "
814 "reducing truncate; rc = [%d]\n", rc
);
818 truncate_setsize(inode
, ia
->ia_size
);
819 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
821 printk(KERN_ERR
"Problem with "
822 "ecryptfs_write_inode_size_to_metadata; "
826 /* We are reducing the size of the ecryptfs file, and need to
827 * know if we need to reduce the size of the lower file. */
828 lower_size_before_truncate
=
829 upper_size_to_lower_size(crypt_stat
, i_size
);
830 lower_size_after_truncate
=
831 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
832 if (lower_size_after_truncate
< lower_size_before_truncate
) {
833 lower_ia
->ia_size
= lower_size_after_truncate
;
834 lower_ia
->ia_valid
|= ATTR_SIZE
;
836 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
839 ecryptfs_put_lower_file(inode
);
843 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
845 struct ecryptfs_crypt_stat
*crypt_stat
;
846 loff_t lower_oldsize
, lower_newsize
;
848 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
849 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
851 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
852 if (lower_newsize
> lower_oldsize
) {
854 * The eCryptfs inode and the new *lower* size are mixed here
855 * because we may not have the lower i_mutex held and/or it may
856 * not be appropriate to call inode_newsize_ok() with inodes
857 * from other filesystems.
859 return inode_newsize_ok(inode
, lower_newsize
);
867 * @dentry: The ecryptfs layer dentry
868 * @new_length: The length to expand the file to
870 * Simple function that handles the truncation of an eCryptfs inode and
871 * its corresponding lower inode.
873 * Returns zero on success; non-zero otherwise
875 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
877 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
878 struct iattr lower_ia
= { .ia_valid
= 0 };
881 rc
= ecryptfs_inode_newsize_ok(dentry
->d_inode
, new_length
);
885 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
886 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
887 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
889 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
890 rc
= notify_change(lower_dentry
, &lower_ia
);
891 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
897 ecryptfs_permission(struct inode
*inode
, int mask
)
899 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
904 * @dentry: dentry handle to the inode to modify
905 * @ia: Structure with flags of what to change and values
907 * Updates the metadata of an inode. If the update is to the size
908 * i.e. truncation, then ecryptfs_truncate will handle the size modification
909 * of both the ecryptfs inode and the lower inode.
911 * All other metadata changes will be passed right to the lower filesystem,
912 * and we will just update our inode to look like the lower.
914 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
917 struct dentry
*lower_dentry
;
918 struct iattr lower_ia
;
920 struct inode
*lower_inode
;
921 struct ecryptfs_crypt_stat
*crypt_stat
;
923 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
924 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
925 ecryptfs_init_crypt_stat(crypt_stat
);
926 inode
= dentry
->d_inode
;
927 lower_inode
= ecryptfs_inode_to_lower(inode
);
928 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
929 mutex_lock(&crypt_stat
->cs_mutex
);
930 if (S_ISDIR(dentry
->d_inode
->i_mode
))
931 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
932 else if (S_ISREG(dentry
->d_inode
->i_mode
)
933 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
934 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
935 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
937 mount_crypt_stat
= &ecryptfs_superblock_to_private(
938 dentry
->d_sb
)->mount_crypt_stat
;
939 rc
= ecryptfs_get_lower_file(dentry
, inode
);
941 mutex_unlock(&crypt_stat
->cs_mutex
);
944 rc
= ecryptfs_read_metadata(dentry
);
945 ecryptfs_put_lower_file(inode
);
947 if (!(mount_crypt_stat
->flags
948 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
950 printk(KERN_WARNING
"Either the lower file "
951 "is not in a valid eCryptfs format, "
952 "or the key could not be retrieved. "
953 "Plaintext passthrough mode is not "
954 "enabled; returning -EIO\n");
955 mutex_unlock(&crypt_stat
->cs_mutex
);
959 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
960 | ECRYPTFS_ENCRYPTED
);
963 mutex_unlock(&crypt_stat
->cs_mutex
);
965 rc
= inode_change_ok(inode
, ia
);
968 if (ia
->ia_valid
& ATTR_SIZE
) {
969 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
974 if (S_ISREG(inode
->i_mode
)) {
975 rc
= filemap_write_and_wait(inode
->i_mapping
);
978 fsstack_copy_attr_all(inode
, lower_inode
);
980 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
981 if (ia
->ia_valid
& ATTR_FILE
)
982 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
983 if (ia
->ia_valid
& ATTR_SIZE
) {
984 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
990 * mode change is for clearing setuid/setgid bits. Allow lower fs
991 * to interpret this in its own way.
993 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
994 lower_ia
.ia_valid
&= ~ATTR_MODE
;
996 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
997 rc
= notify_change(lower_dentry
, &lower_ia
);
998 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1000 fsstack_copy_attr_all(inode
, lower_inode
);
1004 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1007 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1010 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1011 dentry
->d_sb
)->mount_crypt_stat
;
1012 generic_fillattr(dentry
->d_inode
, stat
);
1013 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1017 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1020 stat
->size
= targetsiz
;
1026 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1029 struct kstat lower_stat
;
1032 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1033 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1035 fsstack_copy_attr_all(dentry
->d_inode
,
1036 ecryptfs_inode_to_lower(dentry
->d_inode
));
1037 generic_fillattr(dentry
->d_inode
, stat
);
1038 stat
->blocks
= lower_stat
.blocks
;
1044 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1045 size_t size
, int flags
)
1048 struct dentry
*lower_dentry
;
1050 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1051 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1056 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1058 fsstack_copy_attr_all(dentry
->d_inode
, lower_dentry
->d_inode
);
1064 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1065 void *value
, size_t size
)
1069 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1073 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1074 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1076 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1082 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1085 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1090 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1093 struct dentry
*lower_dentry
;
1095 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1096 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1100 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1101 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1102 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1107 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1110 struct dentry
*lower_dentry
;
1112 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1113 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1117 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1118 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1119 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1124 const struct inode_operations ecryptfs_symlink_iops
= {
1125 .readlink
= generic_readlink
,
1126 .follow_link
= ecryptfs_follow_link
,
1127 .put_link
= ecryptfs_put_link
,
1128 .permission
= ecryptfs_permission
,
1129 .setattr
= ecryptfs_setattr
,
1130 .getattr
= ecryptfs_getattr_link
,
1131 .setxattr
= ecryptfs_setxattr
,
1132 .getxattr
= ecryptfs_getxattr
,
1133 .listxattr
= ecryptfs_listxattr
,
1134 .removexattr
= ecryptfs_removexattr
1137 const struct inode_operations ecryptfs_dir_iops
= {
1138 .create
= ecryptfs_create
,
1139 .lookup
= ecryptfs_lookup
,
1140 .link
= ecryptfs_link
,
1141 .unlink
= ecryptfs_unlink
,
1142 .symlink
= ecryptfs_symlink
,
1143 .mkdir
= ecryptfs_mkdir
,
1144 .rmdir
= ecryptfs_rmdir
,
1145 .mknod
= ecryptfs_mknod
,
1146 .rename
= ecryptfs_rename
,
1147 .permission
= ecryptfs_permission
,
1148 .setattr
= ecryptfs_setattr
,
1149 .setxattr
= ecryptfs_setxattr
,
1150 .getxattr
= ecryptfs_getxattr
,
1151 .listxattr
= ecryptfs_listxattr
,
1152 .removexattr
= ecryptfs_removexattr
1155 const struct inode_operations ecryptfs_main_iops
= {
1156 .permission
= ecryptfs_permission
,
1157 .setattr
= ecryptfs_setattr
,
1158 .getattr
= ecryptfs_getattr
,
1159 .setxattr
= ecryptfs_setxattr
,
1160 .getxattr
= ecryptfs_getxattr
,
1161 .listxattr
= ecryptfs_listxattr
,
1162 .removexattr
= ecryptfs_removexattr