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_mount_crypt_stat
*mount_crypt_stat
;
229 struct ecryptfs_crypt_stat
*crypt_stat
;
230 char *page_virt
= NULL
;
232 int put_lower
= 0, rc
= 0;
234 lower_dir_dentry
= lower_dentry
->d_parent
;
235 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
236 ecryptfs_dentry
->d_parent
));
237 lower_inode
= lower_dentry
->d_inode
;
238 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
239 BUG_ON(!lower_dentry
->d_count
);
240 ecryptfs_set_dentry_private(ecryptfs_dentry
,
241 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
243 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
245 printk(KERN_ERR
"%s: Out of memory whilst attempting "
246 "to allocate ecryptfs_dentry_info struct\n",
250 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
251 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
252 if (!lower_dentry
->d_inode
) {
253 /* We want to add because we couldn't find in lower */
254 d_add(ecryptfs_dentry
, NULL
);
257 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
258 ecryptfs_dir_inode
->i_sb
,
259 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
261 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
265 if (S_ISDIR(lower_inode
->i_mode
))
267 if (S_ISLNK(lower_inode
->i_mode
))
269 if (special_file(lower_inode
->i_mode
))
271 /* Released in this function */
272 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
274 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
279 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
);
281 printk(KERN_ERR
"%s: Error attempting to initialize "
282 "the lower file for the dentry with name "
283 "[%s]; rc = [%d]\n", __func__
,
284 ecryptfs_dentry
->d_name
.name
, rc
);
288 crypt_stat
= &ecryptfs_inode_to_private(
289 ecryptfs_dentry
->d_inode
)->crypt_stat
;
290 /* TODO: lock for crypt_stat comparison */
291 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
292 ecryptfs_set_default_sizes(crypt_stat
);
293 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
294 ecryptfs_dentry
->d_inode
);
296 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
297 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
303 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
305 mount_crypt_stat
= &ecryptfs_superblock_to_private(
306 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
307 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
308 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
309 file_size
= (crypt_stat
->metadata_size
310 + i_size_read(lower_dentry
->d_inode
));
312 file_size
= i_size_read(lower_dentry
->d_inode
);
314 file_size
= get_unaligned_be64(page_virt
);
316 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
318 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
323 d_drop(ecryptfs_dentry
);
326 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
332 * @ecryptfs_dir_inode: The eCryptfs directory inode
333 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
334 * @ecryptfs_nd: nameidata; may be NULL
336 * Find a file on disk. If the file does not exist, then we'll add it to the
337 * dentry cache and continue on to read it from the disk.
339 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
340 struct dentry
*ecryptfs_dentry
,
341 struct nameidata
*ecryptfs_nd
)
343 char *encrypted_and_encoded_name
= NULL
;
344 size_t encrypted_and_encoded_name_size
;
345 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
346 struct dentry
*lower_dir_dentry
, *lower_dentry
;
349 if ((ecryptfs_dentry
->d_name
.len
== 1
350 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
351 || (ecryptfs_dentry
->d_name
.len
== 2
352 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
355 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
356 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
357 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
359 ecryptfs_dentry
->d_name
.len
);
360 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
361 if (IS_ERR(lower_dentry
)) {
362 rc
= PTR_ERR(lower_dentry
);
363 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
364 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
365 encrypted_and_encoded_name
);
368 if (lower_dentry
->d_inode
)
369 goto lookup_and_interpose
;
370 mount_crypt_stat
= &ecryptfs_superblock_to_private(
371 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
372 if (!(mount_crypt_stat
373 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
374 goto lookup_and_interpose
;
376 rc
= ecryptfs_encrypt_and_encode_filename(
377 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
378 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
379 ecryptfs_dentry
->d_name
.len
);
381 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
382 "filename; rc = [%d]\n", __func__
, rc
);
385 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
386 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
388 encrypted_and_encoded_name_size
);
389 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
390 if (IS_ERR(lower_dentry
)) {
391 rc
= PTR_ERR(lower_dentry
);
392 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
393 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
394 encrypted_and_encoded_name
);
397 lookup_and_interpose
:
398 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
402 d_drop(ecryptfs_dentry
);
404 kfree(encrypted_and_encoded_name
);
408 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
409 struct dentry
*new_dentry
)
411 struct dentry
*lower_old_dentry
;
412 struct dentry
*lower_new_dentry
;
413 struct dentry
*lower_dir_dentry
;
417 file_size_save
= i_size_read(old_dentry
->d_inode
);
418 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
419 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
420 dget(lower_old_dentry
);
421 dget(lower_new_dentry
);
422 lower_dir_dentry
= lock_parent(lower_new_dentry
);
423 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
425 if (rc
|| !lower_new_dentry
->d_inode
)
427 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
430 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
431 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
432 old_dentry
->d_inode
->i_nlink
=
433 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
434 i_size_write(new_dentry
->d_inode
, file_size_save
);
436 unlock_dir(lower_dir_dentry
);
437 dput(lower_new_dentry
);
438 dput(lower_old_dentry
);
442 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
445 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
446 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
447 struct dentry
*lower_dir_dentry
;
450 lower_dir_dentry
= lock_parent(lower_dentry
);
451 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
453 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
456 fsstack_copy_attr_times(dir
, lower_dir_inode
);
457 dentry
->d_inode
->i_nlink
=
458 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
459 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
462 unlock_dir(lower_dir_dentry
);
467 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
471 struct dentry
*lower_dentry
;
472 struct dentry
*lower_dir_dentry
;
473 char *encoded_symname
;
474 size_t encoded_symlen
;
475 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
477 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
479 lower_dir_dentry
= lock_parent(lower_dentry
);
480 mount_crypt_stat
= &ecryptfs_superblock_to_private(
481 dir
->i_sb
)->mount_crypt_stat
;
482 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
485 mount_crypt_stat
, symname
,
489 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
491 kfree(encoded_symname
);
492 if (rc
|| !lower_dentry
->d_inode
)
494 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
497 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
498 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
500 unlock_dir(lower_dir_dentry
);
502 if (!dentry
->d_inode
)
507 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
510 struct dentry
*lower_dentry
;
511 struct dentry
*lower_dir_dentry
;
513 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
514 lower_dir_dentry
= lock_parent(lower_dentry
);
515 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
516 if (rc
|| !lower_dentry
->d_inode
)
518 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
521 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
522 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
523 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
525 unlock_dir(lower_dir_dentry
);
526 if (!dentry
->d_inode
)
531 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
533 struct dentry
*lower_dentry
;
534 struct dentry
*lower_dir_dentry
;
537 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
539 lower_dir_dentry
= lock_parent(lower_dentry
);
541 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
543 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
544 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
545 unlock_dir(lower_dir_dentry
);
553 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
556 struct dentry
*lower_dentry
;
557 struct dentry
*lower_dir_dentry
;
559 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
560 lower_dir_dentry
= lock_parent(lower_dentry
);
561 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
562 if (rc
|| !lower_dentry
->d_inode
)
564 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
567 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
568 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
570 unlock_dir(lower_dir_dentry
);
571 if (!dentry
->d_inode
)
577 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
578 struct inode
*new_dir
, struct dentry
*new_dentry
)
581 struct dentry
*lower_old_dentry
;
582 struct dentry
*lower_new_dentry
;
583 struct dentry
*lower_old_dir_dentry
;
584 struct dentry
*lower_new_dir_dentry
;
585 struct dentry
*trap
= NULL
;
587 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
588 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
589 dget(lower_old_dentry
);
590 dget(lower_new_dentry
);
591 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
592 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
593 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
594 /* source should not be ancestor of target */
595 if (trap
== lower_old_dentry
) {
599 /* target should not be ancestor of source */
600 if (trap
== lower_new_dentry
) {
604 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
605 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
608 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
609 if (new_dir
!= old_dir
)
610 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
612 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
613 dput(lower_new_dir_dentry
);
614 dput(lower_old_dir_dentry
);
615 dput(lower_new_dentry
);
616 dput(lower_old_dentry
);
620 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
623 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
625 size_t lower_bufsiz
= PATH_MAX
;
629 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
636 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
637 (char __user
*)lower_buf
,
643 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
644 lower_buf
, lower_bufsiz
);
651 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
654 size_t kbufsiz
, copied
;
657 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
660 copied
= min_t(size_t, bufsiz
, kbufsiz
);
661 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
663 fsstack_copy_attr_atime(dentry
->d_inode
,
664 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
669 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
672 int len
= PAGE_SIZE
, rc
;
675 /* Released in ecryptfs_put_link(); only release here on error */
676 buf
= kmalloc(len
, GFP_KERNEL
);
678 buf
= ERR_PTR(-ENOMEM
);
683 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
691 nd_set_link(nd
, buf
);
696 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
698 char *buf
= nd_get_link(nd
);
706 * upper_size_to_lower_size
707 * @crypt_stat: Crypt_stat associated with file
708 * @upper_size: Size of the upper file
710 * Calculate the required size of the lower file based on the
711 * specified size of the upper file. This calculation is based on the
712 * number of headers in the underlying file and the extent size.
714 * Returns Calculated size of the lower file.
717 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
722 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
723 if (upper_size
!= 0) {
726 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
727 if (upper_size
& ~crypt_stat
->extent_mask
)
729 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
736 * @dentry: The ecryptfs layer dentry
737 * @ia: Address of the ecryptfs inode's attributes
738 * @lower_ia: Address of the lower inode's attributes
740 * Function to handle truncations modifying the size of the file. Note
741 * that the file sizes are interpolated. When expanding, we are simply
742 * writing strings of 0's out. When truncating, we truncate the upper
743 * inode and update the lower_ia according to the page index
744 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
745 * the caller must use lower_ia in a call to notify_change() to perform
746 * the truncation of the lower inode.
748 * Returns zero on success; non-zero otherwise
750 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
751 struct iattr
*lower_ia
)
754 struct inode
*inode
= dentry
->d_inode
;
755 struct ecryptfs_crypt_stat
*crypt_stat
;
756 loff_t i_size
= i_size_read(inode
);
757 loff_t lower_size_before_truncate
;
758 loff_t lower_size_after_truncate
;
760 if (unlikely((ia
->ia_size
== i_size
))) {
761 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
764 rc
= ecryptfs_get_lower_file(dentry
);
767 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
768 /* Switch on growing or shrinking file */
769 if (ia
->ia_size
> i_size
) {
770 char zero
[] = { 0x00 };
772 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
773 /* Write a single 0 at the last position of the file;
774 * this triggers code that will fill in 0's throughout
775 * the intermediate portion of the previous end of the
776 * file and the new and of the file */
777 rc
= ecryptfs_write(inode
, zero
,
778 (ia
->ia_size
- 1), 1);
779 } else { /* ia->ia_size < i_size_read(inode) */
780 /* We're chopping off all the pages down to the page
781 * in which ia->ia_size is located. Fill in the end of
782 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
783 * PAGE_CACHE_SIZE with zeros. */
784 size_t num_zeros
= (PAGE_CACHE_SIZE
785 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
789 * XXX(truncate) this should really happen at the begginning
790 * of ->setattr. But the code is too messy to that as part
791 * of a larger patch. ecryptfs is also totally missing out
792 * on the inode_change_ok check at the beginning of
793 * ->setattr while would include this.
795 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
799 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
800 truncate_setsize(inode
, ia
->ia_size
);
801 lower_ia
->ia_size
= ia
->ia_size
;
802 lower_ia
->ia_valid
|= ATTR_SIZE
;
808 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
813 rc
= ecryptfs_write(inode
, zeros_virt
,
814 ia
->ia_size
, num_zeros
);
817 printk(KERN_ERR
"Error attempting to zero out "
818 "the remainder of the end page on "
819 "reducing truncate; rc = [%d]\n", rc
);
823 truncate_setsize(inode
, ia
->ia_size
);
824 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
826 printk(KERN_ERR
"Problem with "
827 "ecryptfs_write_inode_size_to_metadata; "
831 /* We are reducing the size of the ecryptfs file, and need to
832 * know if we need to reduce the size of the lower file. */
833 lower_size_before_truncate
=
834 upper_size_to_lower_size(crypt_stat
, i_size
);
835 lower_size_after_truncate
=
836 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
837 if (lower_size_after_truncate
< lower_size_before_truncate
) {
838 lower_ia
->ia_size
= lower_size_after_truncate
;
839 lower_ia
->ia_valid
|= ATTR_SIZE
;
841 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
844 ecryptfs_put_lower_file(inode
);
850 * @dentry: The ecryptfs layer dentry
851 * @new_length: The length to expand the file to
853 * Simple function that handles the truncation of an eCryptfs inode and
854 * its corresponding lower inode.
856 * Returns zero on success; non-zero otherwise
858 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
860 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
861 struct iattr lower_ia
= { .ia_valid
= 0 };
864 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
865 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
866 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
868 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
869 rc
= notify_change(lower_dentry
, &lower_ia
);
870 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
876 ecryptfs_permission(struct inode
*inode
, int mask
, unsigned int flags
)
878 if (flags
& IPERM_FLAG_RCU
)
880 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
885 * @dentry: dentry handle to the inode to modify
886 * @ia: Structure with flags of what to change and values
888 * Updates the metadata of an inode. If the update is to the size
889 * i.e. truncation, then ecryptfs_truncate will handle the size modification
890 * of both the ecryptfs inode and the lower inode.
892 * All other metadata changes will be passed right to the lower filesystem,
893 * and we will just update our inode to look like the lower.
895 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
898 struct dentry
*lower_dentry
;
899 struct iattr lower_ia
;
901 struct inode
*lower_inode
;
902 struct ecryptfs_crypt_stat
*crypt_stat
;
904 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
905 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
906 ecryptfs_init_crypt_stat(crypt_stat
);
907 inode
= dentry
->d_inode
;
908 lower_inode
= ecryptfs_inode_to_lower(inode
);
909 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
910 mutex_lock(&crypt_stat
->cs_mutex
);
911 if (S_ISDIR(dentry
->d_inode
->i_mode
))
912 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
913 else if (S_ISREG(dentry
->d_inode
->i_mode
)
914 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
915 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
916 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
918 mount_crypt_stat
= &ecryptfs_superblock_to_private(
919 dentry
->d_sb
)->mount_crypt_stat
;
920 rc
= ecryptfs_get_lower_file(dentry
);
922 mutex_unlock(&crypt_stat
->cs_mutex
);
925 rc
= ecryptfs_read_metadata(dentry
);
926 ecryptfs_put_lower_file(inode
);
928 if (!(mount_crypt_stat
->flags
929 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
931 printk(KERN_WARNING
"Either the lower file "
932 "is not in a valid eCryptfs format, "
933 "or the key could not be retrieved. "
934 "Plaintext passthrough mode is not "
935 "enabled; returning -EIO\n");
936 mutex_unlock(&crypt_stat
->cs_mutex
);
940 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
943 mutex_unlock(&crypt_stat
->cs_mutex
);
944 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
945 if (ia
->ia_valid
& ATTR_FILE
)
946 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
947 if (ia
->ia_valid
& ATTR_SIZE
) {
948 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
954 * mode change is for clearing setuid/setgid bits. Allow lower fs
955 * to interpret this in its own way.
957 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
958 lower_ia
.ia_valid
&= ~ATTR_MODE
;
960 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
961 rc
= notify_change(lower_dentry
, &lower_ia
);
962 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
964 fsstack_copy_attr_all(inode
, lower_inode
);
968 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
971 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
974 mount_crypt_stat
= &ecryptfs_superblock_to_private(
975 dentry
->d_sb
)->mount_crypt_stat
;
976 generic_fillattr(dentry
->d_inode
, stat
);
977 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
981 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
984 stat
->size
= targetsiz
;
990 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
993 struct kstat lower_stat
;
996 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
997 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
999 fsstack_copy_attr_all(dentry
->d_inode
,
1000 ecryptfs_inode_to_lower(dentry
->d_inode
));
1001 generic_fillattr(dentry
->d_inode
, stat
);
1002 stat
->blocks
= lower_stat
.blocks
;
1008 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1009 size_t size
, int flags
)
1012 struct dentry
*lower_dentry
;
1014 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1015 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1020 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1026 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1027 void *value
, size_t size
)
1031 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1035 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1036 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1038 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1044 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1047 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1052 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1055 struct dentry
*lower_dentry
;
1057 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1058 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1062 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1063 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1064 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1069 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1072 struct dentry
*lower_dentry
;
1074 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1075 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1079 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1080 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1081 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1086 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1088 if ((ecryptfs_inode_to_lower(inode
)
1089 == (struct inode
*)candidate_lower_inode
))
1095 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1097 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1101 const struct inode_operations ecryptfs_symlink_iops
= {
1102 .readlink
= ecryptfs_readlink
,
1103 .follow_link
= ecryptfs_follow_link
,
1104 .put_link
= ecryptfs_put_link
,
1105 .permission
= ecryptfs_permission
,
1106 .setattr
= ecryptfs_setattr
,
1107 .getattr
= ecryptfs_getattr_link
,
1108 .setxattr
= ecryptfs_setxattr
,
1109 .getxattr
= ecryptfs_getxattr
,
1110 .listxattr
= ecryptfs_listxattr
,
1111 .removexattr
= ecryptfs_removexattr
1114 const struct inode_operations ecryptfs_dir_iops
= {
1115 .create
= ecryptfs_create
,
1116 .lookup
= ecryptfs_lookup
,
1117 .link
= ecryptfs_link
,
1118 .unlink
= ecryptfs_unlink
,
1119 .symlink
= ecryptfs_symlink
,
1120 .mkdir
= ecryptfs_mkdir
,
1121 .rmdir
= ecryptfs_rmdir
,
1122 .mknod
= ecryptfs_mknod
,
1123 .rename
= ecryptfs_rename
,
1124 .permission
= ecryptfs_permission
,
1125 .setattr
= ecryptfs_setattr
,
1126 .setxattr
= ecryptfs_setxattr
,
1127 .getxattr
= ecryptfs_getxattr
,
1128 .listxattr
= ecryptfs_listxattr
,
1129 .removexattr
= ecryptfs_removexattr
1132 const struct inode_operations ecryptfs_main_iops
= {
1133 .permission
= ecryptfs_permission
,
1134 .setattr
= ecryptfs_setattr
,
1135 .getattr
= ecryptfs_getattr
,
1136 .setxattr
= ecryptfs_setxattr
,
1137 .getxattr
= ecryptfs_getxattr
,
1138 .listxattr
= ecryptfs_listxattr
,
1139 .removexattr
= ecryptfs_removexattr