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
;
73 if (S_ISLNK(inode
->i_mode
))
74 inode
->i_op
= &ecryptfs_symlink_iops
;
75 else if (S_ISDIR(inode
->i_mode
))
76 inode
->i_op
= &ecryptfs_dir_iops
;
78 inode
->i_op
= &ecryptfs_main_iops
;
80 if (S_ISDIR(inode
->i_mode
))
81 inode
->i_fop
= &ecryptfs_dir_fops
;
82 else if (special_file(inode
->i_mode
))
83 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
85 inode
->i_fop
= &ecryptfs_main_fops
;
90 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
91 struct super_block
*sb
)
95 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
96 return ERR_PTR(-EXDEV
);
97 if (!igrab(lower_inode
))
98 return ERR_PTR(-ESTALE
);
99 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
100 ecryptfs_inode_test
, ecryptfs_inode_set
,
104 return ERR_PTR(-EACCES
);
106 if (!(inode
->i_state
& I_NEW
))
112 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
113 struct super_block
*sb
)
115 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
117 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
118 unlock_new_inode(inode
);
125 * @lower_dentry: Existing dentry in the lower filesystem
126 * @dentry: ecryptfs' dentry
127 * @sb: ecryptfs's super_block
129 * Interposes upper and lower dentries.
131 * Returns zero on success; non-zero otherwise
133 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
134 struct dentry
*dentry
, struct super_block
*sb
)
136 struct inode
*inode
= ecryptfs_get_inode(lower_dentry
->d_inode
, sb
);
139 return PTR_ERR(inode
);
140 d_instantiate(dentry
, inode
);
146 * ecryptfs_create_underlying_file
147 * @lower_dir_inode: inode of the parent in the lower fs of the new file
148 * @dentry: New file's dentry
149 * @mode: The mode of the new file
151 * Creates the file in the lower file system.
153 * Returns zero on success; non-zero on error condition
156 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
157 struct dentry
*dentry
, int mode
)
159 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
160 return vfs_create(lower_dir_inode
, lower_dentry
, mode
, NULL
);
165 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
166 * @ecryptfs_dentry: New file's dentry in ecryptfs
167 * @mode: The mode of the new file
168 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
170 * Creates the underlying file and the eCryptfs inode which will link to
171 * it. It will also update the eCryptfs directory inode to mimic the
172 * stat of the lower directory inode.
174 * Returns zero on success; non-zero on error condition
177 ecryptfs_do_create(struct inode
*directory_inode
,
178 struct dentry
*ecryptfs_dentry
, int mode
)
181 struct dentry
*lower_dentry
;
182 struct dentry
*lower_dir_dentry
;
184 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
185 lower_dir_dentry
= lock_parent(lower_dentry
);
186 if (IS_ERR(lower_dir_dentry
)) {
187 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
189 rc
= PTR_ERR(lower_dir_dentry
);
192 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
193 ecryptfs_dentry
, mode
);
195 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
196 "rc = [%d]\n", __func__
, rc
);
199 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
200 directory_inode
->i_sb
);
202 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
205 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
206 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
208 unlock_dir(lower_dir_dentry
);
214 * ecryptfs_initialize_file
216 * Cause the file to be changed from a basic empty file to an ecryptfs
217 * file with a header and first data page.
219 * Returns zero on success
221 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
223 struct ecryptfs_crypt_stat
*crypt_stat
=
224 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
227 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
228 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
229 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
232 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
233 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
235 ecryptfs_printk(KERN_ERR
, "Error creating new file "
236 "context; rc = [%d]\n", rc
);
239 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
,
240 ecryptfs_dentry
->d_inode
);
242 printk(KERN_ERR
"%s: Error attempting to initialize "
243 "the lower file for the dentry with name "
244 "[%s]; rc = [%d]\n", __func__
,
245 ecryptfs_dentry
->d_name
.name
, rc
);
248 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
250 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
251 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
258 * @dir: The inode of the directory in which to create the file.
259 * @dentry: The eCryptfs dentry
260 * @mode: The mode of the new file.
263 * Creates a new file.
265 * Returns zero on success; non-zero on error condition
268 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
269 int mode
, struct nameidata
*nd
)
273 /* ecryptfs_do_create() calls ecryptfs_interpose() */
274 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
);
276 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
277 "lower filesystem\n");
280 /* At this point, a file exists on "disk"; we need to make sure
281 * that this on disk file is prepared to be an ecryptfs file */
282 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
287 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
289 struct ecryptfs_crypt_stat
*crypt_stat
;
292 rc
= ecryptfs_get_lower_file(dentry
, inode
);
294 printk(KERN_ERR
"%s: Error attempting to initialize "
295 "the lower file for the dentry with name "
296 "[%s]; rc = [%d]\n", __func__
,
297 dentry
->d_name
.name
, rc
);
301 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
302 /* TODO: lock for crypt_stat comparison */
303 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
304 ecryptfs_set_default_sizes(crypt_stat
);
306 rc
= ecryptfs_read_and_validate_header_region(inode
);
307 ecryptfs_put_lower_file(inode
);
309 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
311 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
314 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
319 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
321 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
322 struct dentry
*lower_dentry
,
323 struct inode
*dir_inode
)
325 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
326 struct ecryptfs_dentry_info
*dentry_info
;
327 struct vfsmount
*lower_mnt
;
330 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
331 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
332 BUG_ON(!lower_dentry
->d_count
);
334 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
335 ecryptfs_set_dentry_private(dentry
, dentry_info
);
337 printk(KERN_ERR
"%s: Out of memory whilst attempting "
338 "to allocate ecryptfs_dentry_info struct\n",
345 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
346 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
348 if (!lower_dentry
->d_inode
) {
349 /* We want to add because we couldn't find in lower */
353 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
355 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
356 __func__
, PTR_ERR(inode
));
357 return PTR_ERR(inode
);
359 if (S_ISREG(inode
->i_mode
)) {
360 rc
= ecryptfs_i_size_read(dentry
, inode
);
362 make_bad_inode(inode
);
367 if (inode
->i_state
& I_NEW
)
368 unlock_new_inode(inode
);
369 d_add(dentry
, inode
);
376 * @ecryptfs_dir_inode: The eCryptfs directory inode
377 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
378 * @ecryptfs_nd: nameidata; may be NULL
380 * Find a file on disk. If the file does not exist, then we'll add it to the
381 * dentry cache and continue on to read it from the disk.
383 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
384 struct dentry
*ecryptfs_dentry
,
385 struct nameidata
*ecryptfs_nd
)
387 char *encrypted_and_encoded_name
= NULL
;
388 size_t encrypted_and_encoded_name_size
;
389 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
390 struct dentry
*lower_dir_dentry
, *lower_dentry
;
393 if ((ecryptfs_dentry
->d_name
.len
== 1
394 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
395 || (ecryptfs_dentry
->d_name
.len
== 2
396 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
399 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
400 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
401 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
403 ecryptfs_dentry
->d_name
.len
);
404 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
405 if (IS_ERR(lower_dentry
)) {
406 rc
= PTR_ERR(lower_dentry
);
407 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
408 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
409 encrypted_and_encoded_name
);
412 if (lower_dentry
->d_inode
)
414 mount_crypt_stat
= &ecryptfs_superblock_to_private(
415 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
416 if (!(mount_crypt_stat
417 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
420 rc
= ecryptfs_encrypt_and_encode_filename(
421 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
422 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
423 ecryptfs_dentry
->d_name
.len
);
425 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
426 "filename; rc = [%d]\n", __func__
, rc
);
429 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
430 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
432 encrypted_and_encoded_name_size
);
433 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
434 if (IS_ERR(lower_dentry
)) {
435 rc
= PTR_ERR(lower_dentry
);
436 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
437 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
438 encrypted_and_encoded_name
);
442 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
446 d_drop(ecryptfs_dentry
);
448 kfree(encrypted_and_encoded_name
);
452 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
453 struct dentry
*new_dentry
)
455 struct dentry
*lower_old_dentry
;
456 struct dentry
*lower_new_dentry
;
457 struct dentry
*lower_dir_dentry
;
461 file_size_save
= i_size_read(old_dentry
->d_inode
);
462 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
463 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
464 dget(lower_old_dentry
);
465 dget(lower_new_dentry
);
466 lower_dir_dentry
= lock_parent(lower_new_dentry
);
467 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
469 if (rc
|| !lower_new_dentry
->d_inode
)
471 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
474 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
475 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
476 old_dentry
->d_inode
->i_nlink
=
477 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
478 i_size_write(new_dentry
->d_inode
, file_size_save
);
480 unlock_dir(lower_dir_dentry
);
481 dput(lower_new_dentry
);
482 dput(lower_old_dentry
);
486 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
489 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
490 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
491 struct dentry
*lower_dir_dentry
;
494 lower_dir_dentry
= lock_parent(lower_dentry
);
495 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
497 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
500 fsstack_copy_attr_times(dir
, lower_dir_inode
);
501 dentry
->d_inode
->i_nlink
=
502 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
503 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
506 unlock_dir(lower_dir_dentry
);
511 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
515 struct dentry
*lower_dentry
;
516 struct dentry
*lower_dir_dentry
;
517 char *encoded_symname
;
518 size_t encoded_symlen
;
519 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
521 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
523 lower_dir_dentry
= lock_parent(lower_dentry
);
524 mount_crypt_stat
= &ecryptfs_superblock_to_private(
525 dir
->i_sb
)->mount_crypt_stat
;
526 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
529 mount_crypt_stat
, symname
,
533 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
535 kfree(encoded_symname
);
536 if (rc
|| !lower_dentry
->d_inode
)
538 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
541 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
542 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
544 unlock_dir(lower_dir_dentry
);
546 if (!dentry
->d_inode
)
551 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
554 struct dentry
*lower_dentry
;
555 struct dentry
*lower_dir_dentry
;
557 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
558 lower_dir_dentry
= lock_parent(lower_dentry
);
559 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
560 if (rc
|| !lower_dentry
->d_inode
)
562 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
565 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
566 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
567 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
569 unlock_dir(lower_dir_dentry
);
570 if (!dentry
->d_inode
)
575 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
577 struct dentry
*lower_dentry
;
578 struct dentry
*lower_dir_dentry
;
581 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
583 lower_dir_dentry
= lock_parent(lower_dentry
);
585 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
587 if (!rc
&& dentry
->d_inode
)
588 clear_nlink(dentry
->d_inode
);
589 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
590 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
591 unlock_dir(lower_dir_dentry
);
599 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
602 struct dentry
*lower_dentry
;
603 struct dentry
*lower_dir_dentry
;
605 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
606 lower_dir_dentry
= lock_parent(lower_dentry
);
607 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
608 if (rc
|| !lower_dentry
->d_inode
)
610 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
613 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
614 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
616 unlock_dir(lower_dir_dentry
);
617 if (!dentry
->d_inode
)
623 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
624 struct inode
*new_dir
, struct dentry
*new_dentry
)
627 struct dentry
*lower_old_dentry
;
628 struct dentry
*lower_new_dentry
;
629 struct dentry
*lower_old_dir_dentry
;
630 struct dentry
*lower_new_dir_dentry
;
631 struct dentry
*trap
= NULL
;
633 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
634 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
635 dget(lower_old_dentry
);
636 dget(lower_new_dentry
);
637 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
638 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
639 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
640 /* source should not be ancestor of target */
641 if (trap
== lower_old_dentry
) {
645 /* target should not be ancestor of source */
646 if (trap
== lower_new_dentry
) {
650 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
651 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
654 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
655 if (new_dir
!= old_dir
)
656 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
658 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
659 dput(lower_new_dir_dentry
);
660 dput(lower_old_dir_dentry
);
661 dput(lower_new_dentry
);
662 dput(lower_old_dentry
);
666 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
669 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
671 size_t lower_bufsiz
= PATH_MAX
;
675 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
682 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
683 (char __user
*)lower_buf
,
689 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
690 lower_buf
, lower_bufsiz
);
697 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
700 size_t kbufsiz
, copied
;
703 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
706 copied
= min_t(size_t, bufsiz
, kbufsiz
);
707 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
709 fsstack_copy_attr_atime(dentry
->d_inode
,
710 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
715 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
718 int len
= PAGE_SIZE
, rc
;
721 /* Released in ecryptfs_put_link(); only release here on error */
722 buf
= kmalloc(len
, GFP_KERNEL
);
724 buf
= ERR_PTR(-ENOMEM
);
729 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
737 nd_set_link(nd
, buf
);
742 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
744 char *buf
= nd_get_link(nd
);
752 * upper_size_to_lower_size
753 * @crypt_stat: Crypt_stat associated with file
754 * @upper_size: Size of the upper file
756 * Calculate the required size of the lower file based on the
757 * specified size of the upper file. This calculation is based on the
758 * number of headers in the underlying file and the extent size.
760 * Returns Calculated size of the lower file.
763 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
768 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
769 if (upper_size
!= 0) {
772 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
773 if (upper_size
& ~crypt_stat
->extent_mask
)
775 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
782 * @dentry: The ecryptfs layer dentry
783 * @ia: Address of the ecryptfs inode's attributes
784 * @lower_ia: Address of the lower inode's attributes
786 * Function to handle truncations modifying the size of the file. Note
787 * that the file sizes are interpolated. When expanding, we are simply
788 * writing strings of 0's out. When truncating, we truncate the upper
789 * inode and update the lower_ia according to the page index
790 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
791 * the caller must use lower_ia in a call to notify_change() to perform
792 * the truncation of the lower inode.
794 * Returns zero on success; non-zero otherwise
796 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
797 struct iattr
*lower_ia
)
800 struct inode
*inode
= dentry
->d_inode
;
801 struct ecryptfs_crypt_stat
*crypt_stat
;
802 loff_t i_size
= i_size_read(inode
);
803 loff_t lower_size_before_truncate
;
804 loff_t lower_size_after_truncate
;
806 if (unlikely((ia
->ia_size
== i_size
))) {
807 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
810 rc
= ecryptfs_get_lower_file(dentry
, inode
);
813 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
814 /* Switch on growing or shrinking file */
815 if (ia
->ia_size
> i_size
) {
816 char zero
[] = { 0x00 };
818 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
819 /* Write a single 0 at the last position of the file;
820 * this triggers code that will fill in 0's throughout
821 * the intermediate portion of the previous end of the
822 * file and the new and of the file */
823 rc
= ecryptfs_write(inode
, zero
,
824 (ia
->ia_size
- 1), 1);
825 } else { /* ia->ia_size < i_size_read(inode) */
826 /* We're chopping off all the pages down to the page
827 * in which ia->ia_size is located. Fill in the end of
828 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
829 * PAGE_CACHE_SIZE with zeros. */
830 size_t num_zeros
= (PAGE_CACHE_SIZE
831 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
835 * XXX(truncate) this should really happen at the begginning
836 * of ->setattr. But the code is too messy to that as part
837 * of a larger patch. ecryptfs is also totally missing out
838 * on the inode_change_ok check at the beginning of
839 * ->setattr while would include this.
841 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
845 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
846 truncate_setsize(inode
, ia
->ia_size
);
847 lower_ia
->ia_size
= ia
->ia_size
;
848 lower_ia
->ia_valid
|= ATTR_SIZE
;
854 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
859 rc
= ecryptfs_write(inode
, zeros_virt
,
860 ia
->ia_size
, num_zeros
);
863 printk(KERN_ERR
"Error attempting to zero out "
864 "the remainder of the end page on "
865 "reducing truncate; rc = [%d]\n", rc
);
869 truncate_setsize(inode
, ia
->ia_size
);
870 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
872 printk(KERN_ERR
"Problem with "
873 "ecryptfs_write_inode_size_to_metadata; "
877 /* We are reducing the size of the ecryptfs file, and need to
878 * know if we need to reduce the size of the lower file. */
879 lower_size_before_truncate
=
880 upper_size_to_lower_size(crypt_stat
, i_size
);
881 lower_size_after_truncate
=
882 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
883 if (lower_size_after_truncate
< lower_size_before_truncate
) {
884 lower_ia
->ia_size
= lower_size_after_truncate
;
885 lower_ia
->ia_valid
|= ATTR_SIZE
;
887 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
890 ecryptfs_put_lower_file(inode
);
896 * @dentry: The ecryptfs layer dentry
897 * @new_length: The length to expand the file to
899 * Simple function that handles the truncation of an eCryptfs inode and
900 * its corresponding lower inode.
902 * Returns zero on success; non-zero otherwise
904 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
906 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
907 struct iattr lower_ia
= { .ia_valid
= 0 };
910 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
911 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
912 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
914 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
915 rc
= notify_change(lower_dentry
, &lower_ia
);
916 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
922 ecryptfs_permission(struct inode
*inode
, int mask
)
924 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
929 * @dentry: dentry handle to the inode to modify
930 * @ia: Structure with flags of what to change and values
932 * Updates the metadata of an inode. If the update is to the size
933 * i.e. truncation, then ecryptfs_truncate will handle the size modification
934 * of both the ecryptfs inode and the lower inode.
936 * All other metadata changes will be passed right to the lower filesystem,
937 * and we will just update our inode to look like the lower.
939 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
942 struct dentry
*lower_dentry
;
943 struct iattr lower_ia
;
945 struct inode
*lower_inode
;
946 struct ecryptfs_crypt_stat
*crypt_stat
;
948 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
949 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
950 ecryptfs_init_crypt_stat(crypt_stat
);
951 inode
= dentry
->d_inode
;
952 lower_inode
= ecryptfs_inode_to_lower(inode
);
953 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
954 mutex_lock(&crypt_stat
->cs_mutex
);
955 if (S_ISDIR(dentry
->d_inode
->i_mode
))
956 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
957 else if (S_ISREG(dentry
->d_inode
->i_mode
)
958 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
959 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
960 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
962 mount_crypt_stat
= &ecryptfs_superblock_to_private(
963 dentry
->d_sb
)->mount_crypt_stat
;
964 rc
= ecryptfs_get_lower_file(dentry
, inode
);
966 mutex_unlock(&crypt_stat
->cs_mutex
);
969 rc
= ecryptfs_read_metadata(dentry
);
970 ecryptfs_put_lower_file(inode
);
972 if (!(mount_crypt_stat
->flags
973 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
975 printk(KERN_WARNING
"Either the lower file "
976 "is not in a valid eCryptfs format, "
977 "or the key could not be retrieved. "
978 "Plaintext passthrough mode is not "
979 "enabled; returning -EIO\n");
980 mutex_unlock(&crypt_stat
->cs_mutex
);
984 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
985 | ECRYPTFS_ENCRYPTED
);
988 mutex_unlock(&crypt_stat
->cs_mutex
);
989 if (S_ISREG(inode
->i_mode
)) {
990 rc
= filemap_write_and_wait(inode
->i_mapping
);
993 fsstack_copy_attr_all(inode
, lower_inode
);
995 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
996 if (ia
->ia_valid
& ATTR_FILE
)
997 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
998 if (ia
->ia_valid
& ATTR_SIZE
) {
999 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1005 * mode change is for clearing setuid/setgid bits. Allow lower fs
1006 * to interpret this in its own way.
1008 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1009 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1011 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1012 rc
= notify_change(lower_dentry
, &lower_ia
);
1013 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1015 fsstack_copy_attr_all(inode
, lower_inode
);
1019 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1022 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1025 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1026 dentry
->d_sb
)->mount_crypt_stat
;
1027 generic_fillattr(dentry
->d_inode
, stat
);
1028 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1032 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1035 stat
->size
= targetsiz
;
1041 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1044 struct kstat lower_stat
;
1047 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1048 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1050 fsstack_copy_attr_all(dentry
->d_inode
,
1051 ecryptfs_inode_to_lower(dentry
->d_inode
));
1052 generic_fillattr(dentry
->d_inode
, stat
);
1053 stat
->blocks
= lower_stat
.blocks
;
1059 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1060 size_t size
, int flags
)
1063 struct dentry
*lower_dentry
;
1065 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1066 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1071 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1077 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1078 void *value
, size_t size
)
1082 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1086 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1087 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1089 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1095 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1098 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1103 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1106 struct dentry
*lower_dentry
;
1108 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1109 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1113 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1114 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1115 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1120 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1123 struct dentry
*lower_dentry
;
1125 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1126 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1130 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1131 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1132 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1137 const struct inode_operations ecryptfs_symlink_iops
= {
1138 .readlink
= ecryptfs_readlink
,
1139 .follow_link
= ecryptfs_follow_link
,
1140 .put_link
= ecryptfs_put_link
,
1141 .permission
= ecryptfs_permission
,
1142 .setattr
= ecryptfs_setattr
,
1143 .getattr
= ecryptfs_getattr_link
,
1144 .setxattr
= ecryptfs_setxattr
,
1145 .getxattr
= ecryptfs_getxattr
,
1146 .listxattr
= ecryptfs_listxattr
,
1147 .removexattr
= ecryptfs_removexattr
1150 const struct inode_operations ecryptfs_dir_iops
= {
1151 .create
= ecryptfs_create
,
1152 .lookup
= ecryptfs_lookup
,
1153 .link
= ecryptfs_link
,
1154 .unlink
= ecryptfs_unlink
,
1155 .symlink
= ecryptfs_symlink
,
1156 .mkdir
= ecryptfs_mkdir
,
1157 .rmdir
= ecryptfs_rmdir
,
1158 .mknod
= ecryptfs_mknod
,
1159 .rename
= ecryptfs_rename
,
1160 .permission
= ecryptfs_permission
,
1161 .setattr
= ecryptfs_setattr
,
1162 .setxattr
= ecryptfs_setxattr
,
1163 .getxattr
= ecryptfs_getxattr
,
1164 .listxattr
= ecryptfs_listxattr
,
1165 .removexattr
= ecryptfs_removexattr
1168 const struct inode_operations ecryptfs_main_iops
= {
1169 .permission
= ecryptfs_permission
,
1170 .setattr
= ecryptfs_setattr
,
1171 .getattr
= ecryptfs_getattr
,
1172 .setxattr
= ecryptfs_setxattr
,
1173 .getxattr
= ecryptfs_getxattr
,
1174 .listxattr
= ecryptfs_listxattr
,
1175 .removexattr
= ecryptfs_removexattr