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
150 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
152 * Creates the file in the lower file system.
154 * Returns zero on success; non-zero on error condition
157 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
158 struct dentry
*dentry
, int mode
,
159 struct nameidata
*nd
)
161 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
162 struct vfsmount
*lower_mnt
= ecryptfs_dentry_to_lower_mnt(dentry
);
163 struct dentry
*dentry_save
;
164 struct vfsmount
*vfsmount_save
;
165 unsigned int flags_save
;
169 dentry_save
= nd
->path
.dentry
;
170 vfsmount_save
= nd
->path
.mnt
;
171 flags_save
= nd
->flags
;
172 nd
->path
.dentry
= lower_dentry
;
173 nd
->path
.mnt
= lower_mnt
;
174 nd
->flags
&= ~LOOKUP_OPEN
;
176 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
178 nd
->path
.dentry
= dentry_save
;
179 nd
->path
.mnt
= vfsmount_save
;
180 nd
->flags
= flags_save
;
187 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
188 * @ecryptfs_dentry: New file's dentry in ecryptfs
189 * @mode: The mode of the new file
190 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
192 * Creates the underlying file and the eCryptfs inode which will link to
193 * it. It will also update the eCryptfs directory inode to mimic the
194 * stat of the lower directory inode.
196 * Returns zero on success; non-zero on error condition
199 ecryptfs_do_create(struct inode
*directory_inode
,
200 struct dentry
*ecryptfs_dentry
, int mode
,
201 struct nameidata
*nd
)
204 struct dentry
*lower_dentry
;
205 struct dentry
*lower_dir_dentry
;
207 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
208 lower_dir_dentry
= lock_parent(lower_dentry
);
209 if (IS_ERR(lower_dir_dentry
)) {
210 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
212 rc
= PTR_ERR(lower_dir_dentry
);
215 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
216 ecryptfs_dentry
, mode
, nd
);
218 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
219 "rc = [%d]\n", __func__
, rc
);
222 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
223 directory_inode
->i_sb
);
225 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
228 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
229 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
231 unlock_dir(lower_dir_dentry
);
237 * ecryptfs_initialize_file
239 * Cause the file to be changed from a basic empty file to an ecryptfs
240 * file with a header and first data page.
242 * Returns zero on success
244 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
246 struct ecryptfs_crypt_stat
*crypt_stat
=
247 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
250 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
251 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
252 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
255 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
256 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
258 ecryptfs_printk(KERN_ERR
, "Error creating new file "
259 "context; rc = [%d]\n", rc
);
262 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
,
263 ecryptfs_dentry
->d_inode
);
265 printk(KERN_ERR
"%s: Error attempting to initialize "
266 "the lower file for the dentry with name "
267 "[%s]; rc = [%d]\n", __func__
,
268 ecryptfs_dentry
->d_name
.name
, rc
);
271 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
273 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
274 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
281 * @dir: The inode of the directory in which to create the file.
282 * @dentry: The eCryptfs dentry
283 * @mode: The mode of the new file.
286 * Creates a new file.
288 * Returns zero on success; non-zero on error condition
291 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
292 int mode
, struct nameidata
*nd
)
296 /* ecryptfs_do_create() calls ecryptfs_interpose() */
297 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
299 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
300 "lower filesystem\n");
303 /* At this point, a file exists on "disk"; we need to make sure
304 * that this on disk file is prepared to be an ecryptfs file */
305 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
310 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
312 struct ecryptfs_crypt_stat
*crypt_stat
;
315 rc
= ecryptfs_get_lower_file(dentry
, inode
);
317 printk(KERN_ERR
"%s: Error attempting to initialize "
318 "the lower file for the dentry with name "
319 "[%s]; rc = [%d]\n", __func__
,
320 dentry
->d_name
.name
, rc
);
324 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
325 /* TODO: lock for crypt_stat comparison */
326 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
327 ecryptfs_set_default_sizes(crypt_stat
);
329 rc
= ecryptfs_read_and_validate_header_region(inode
);
330 ecryptfs_put_lower_file(inode
);
332 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
334 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
337 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
342 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
344 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
345 struct dentry
*lower_dentry
,
346 struct inode
*dir_inode
)
348 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
349 struct ecryptfs_dentry_info
*dentry_info
;
350 struct vfsmount
*lower_mnt
;
353 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
354 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
355 BUG_ON(!lower_dentry
->d_count
);
357 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
358 ecryptfs_set_dentry_private(dentry
, dentry_info
);
360 printk(KERN_ERR
"%s: Out of memory whilst attempting "
361 "to allocate ecryptfs_dentry_info struct\n",
368 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
369 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
371 if (!lower_dentry
->d_inode
) {
372 /* We want to add because we couldn't find in lower */
376 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
378 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
379 __func__
, PTR_ERR(inode
));
380 return PTR_ERR(inode
);
382 if (S_ISREG(inode
->i_mode
)) {
383 rc
= ecryptfs_i_size_read(dentry
, inode
);
385 make_bad_inode(inode
);
390 if (inode
->i_state
& I_NEW
)
391 unlock_new_inode(inode
);
392 d_add(dentry
, inode
);
399 * @ecryptfs_dir_inode: The eCryptfs directory inode
400 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
401 * @ecryptfs_nd: nameidata; may be NULL
403 * Find a file on disk. If the file does not exist, then we'll add it to the
404 * dentry cache and continue on to read it from the disk.
406 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
407 struct dentry
*ecryptfs_dentry
,
408 struct nameidata
*ecryptfs_nd
)
410 char *encrypted_and_encoded_name
= NULL
;
411 size_t encrypted_and_encoded_name_size
;
412 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
413 struct dentry
*lower_dir_dentry
, *lower_dentry
;
416 if ((ecryptfs_dentry
->d_name
.len
== 1
417 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
418 || (ecryptfs_dentry
->d_name
.len
== 2
419 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
422 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
423 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
424 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
426 ecryptfs_dentry
->d_name
.len
);
427 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
428 if (IS_ERR(lower_dentry
)) {
429 rc
= PTR_ERR(lower_dentry
);
430 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
431 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
432 encrypted_and_encoded_name
);
435 if (lower_dentry
->d_inode
)
437 mount_crypt_stat
= &ecryptfs_superblock_to_private(
438 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
439 if (!(mount_crypt_stat
440 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
443 rc
= ecryptfs_encrypt_and_encode_filename(
444 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
445 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
446 ecryptfs_dentry
->d_name
.len
);
448 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
449 "filename; rc = [%d]\n", __func__
, rc
);
452 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
453 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
455 encrypted_and_encoded_name_size
);
456 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
457 if (IS_ERR(lower_dentry
)) {
458 rc
= PTR_ERR(lower_dentry
);
459 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
460 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
461 encrypted_and_encoded_name
);
465 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
469 d_drop(ecryptfs_dentry
);
471 kfree(encrypted_and_encoded_name
);
475 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
476 struct dentry
*new_dentry
)
478 struct dentry
*lower_old_dentry
;
479 struct dentry
*lower_new_dentry
;
480 struct dentry
*lower_dir_dentry
;
484 file_size_save
= i_size_read(old_dentry
->d_inode
);
485 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
486 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
487 dget(lower_old_dentry
);
488 dget(lower_new_dentry
);
489 lower_dir_dentry
= lock_parent(lower_new_dentry
);
490 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
492 if (rc
|| !lower_new_dentry
->d_inode
)
494 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
497 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
498 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
499 old_dentry
->d_inode
->i_nlink
=
500 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
501 i_size_write(new_dentry
->d_inode
, file_size_save
);
503 unlock_dir(lower_dir_dentry
);
504 dput(lower_new_dentry
);
505 dput(lower_old_dentry
);
509 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
512 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
513 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
514 struct dentry
*lower_dir_dentry
;
517 lower_dir_dentry
= lock_parent(lower_dentry
);
518 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
520 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
523 fsstack_copy_attr_times(dir
, lower_dir_inode
);
524 dentry
->d_inode
->i_nlink
=
525 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
526 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
529 unlock_dir(lower_dir_dentry
);
534 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
538 struct dentry
*lower_dentry
;
539 struct dentry
*lower_dir_dentry
;
540 char *encoded_symname
;
541 size_t encoded_symlen
;
542 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
544 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
546 lower_dir_dentry
= lock_parent(lower_dentry
);
547 mount_crypt_stat
= &ecryptfs_superblock_to_private(
548 dir
->i_sb
)->mount_crypt_stat
;
549 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
552 mount_crypt_stat
, symname
,
556 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
558 kfree(encoded_symname
);
559 if (rc
|| !lower_dentry
->d_inode
)
561 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
564 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
565 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
567 unlock_dir(lower_dir_dentry
);
569 if (!dentry
->d_inode
)
574 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
577 struct dentry
*lower_dentry
;
578 struct dentry
*lower_dir_dentry
;
580 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
581 lower_dir_dentry
= lock_parent(lower_dentry
);
582 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
583 if (rc
|| !lower_dentry
->d_inode
)
585 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
588 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
589 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
590 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
592 unlock_dir(lower_dir_dentry
);
593 if (!dentry
->d_inode
)
598 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
600 struct dentry
*lower_dentry
;
601 struct dentry
*lower_dir_dentry
;
604 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
606 lower_dir_dentry
= lock_parent(lower_dentry
);
608 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
610 if (!rc
&& dentry
->d_inode
)
611 clear_nlink(dentry
->d_inode
);
612 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
613 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
614 unlock_dir(lower_dir_dentry
);
622 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
625 struct dentry
*lower_dentry
;
626 struct dentry
*lower_dir_dentry
;
628 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
629 lower_dir_dentry
= lock_parent(lower_dentry
);
630 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
631 if (rc
|| !lower_dentry
->d_inode
)
633 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
636 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
637 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
639 unlock_dir(lower_dir_dentry
);
640 if (!dentry
->d_inode
)
646 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
647 struct inode
*new_dir
, struct dentry
*new_dentry
)
650 struct dentry
*lower_old_dentry
;
651 struct dentry
*lower_new_dentry
;
652 struct dentry
*lower_old_dir_dentry
;
653 struct dentry
*lower_new_dir_dentry
;
654 struct dentry
*trap
= NULL
;
656 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
657 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
658 dget(lower_old_dentry
);
659 dget(lower_new_dentry
);
660 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
661 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
662 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
663 /* source should not be ancestor of target */
664 if (trap
== lower_old_dentry
) {
668 /* target should not be ancestor of source */
669 if (trap
== lower_new_dentry
) {
673 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
674 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
677 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
678 if (new_dir
!= old_dir
)
679 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
681 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
682 dput(lower_new_dir_dentry
);
683 dput(lower_old_dir_dentry
);
684 dput(lower_new_dentry
);
685 dput(lower_old_dentry
);
689 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
692 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
694 size_t lower_bufsiz
= PATH_MAX
;
698 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
705 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
706 (char __user
*)lower_buf
,
712 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
713 lower_buf
, lower_bufsiz
);
720 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
723 size_t kbufsiz
, copied
;
726 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
729 copied
= min_t(size_t, bufsiz
, kbufsiz
);
730 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
732 fsstack_copy_attr_atime(dentry
->d_inode
,
733 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
738 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
741 int len
= PAGE_SIZE
, rc
;
744 /* Released in ecryptfs_put_link(); only release here on error */
745 buf
= kmalloc(len
, GFP_KERNEL
);
747 buf
= ERR_PTR(-ENOMEM
);
752 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
760 nd_set_link(nd
, buf
);
765 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
767 char *buf
= nd_get_link(nd
);
775 * upper_size_to_lower_size
776 * @crypt_stat: Crypt_stat associated with file
777 * @upper_size: Size of the upper file
779 * Calculate the required size of the lower file based on the
780 * specified size of the upper file. This calculation is based on the
781 * number of headers in the underlying file and the extent size.
783 * Returns Calculated size of the lower file.
786 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
791 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
792 if (upper_size
!= 0) {
795 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
796 if (upper_size
& ~crypt_stat
->extent_mask
)
798 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
805 * @dentry: The ecryptfs layer dentry
806 * @ia: Address of the ecryptfs inode's attributes
807 * @lower_ia: Address of the lower inode's attributes
809 * Function to handle truncations modifying the size of the file. Note
810 * that the file sizes are interpolated. When expanding, we are simply
811 * writing strings of 0's out. When truncating, we truncate the upper
812 * inode and update the lower_ia according to the page index
813 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
814 * the caller must use lower_ia in a call to notify_change() to perform
815 * the truncation of the lower inode.
817 * Returns zero on success; non-zero otherwise
819 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
820 struct iattr
*lower_ia
)
823 struct inode
*inode
= dentry
->d_inode
;
824 struct ecryptfs_crypt_stat
*crypt_stat
;
825 loff_t i_size
= i_size_read(inode
);
826 loff_t lower_size_before_truncate
;
827 loff_t lower_size_after_truncate
;
829 if (unlikely((ia
->ia_size
== i_size
))) {
830 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
833 rc
= ecryptfs_get_lower_file(dentry
, inode
);
836 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
837 /* Switch on growing or shrinking file */
838 if (ia
->ia_size
> i_size
) {
839 char zero
[] = { 0x00 };
841 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
842 /* Write a single 0 at the last position of the file;
843 * this triggers code that will fill in 0's throughout
844 * the intermediate portion of the previous end of the
845 * file and the new and of the file */
846 rc
= ecryptfs_write(inode
, zero
,
847 (ia
->ia_size
- 1), 1);
848 } else { /* ia->ia_size < i_size_read(inode) */
849 /* We're chopping off all the pages down to the page
850 * in which ia->ia_size is located. Fill in the end of
851 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
852 * PAGE_CACHE_SIZE with zeros. */
853 size_t num_zeros
= (PAGE_CACHE_SIZE
854 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
858 * XXX(truncate) this should really happen at the begginning
859 * of ->setattr. But the code is too messy to that as part
860 * of a larger patch. ecryptfs is also totally missing out
861 * on the inode_change_ok check at the beginning of
862 * ->setattr while would include this.
864 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
868 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
869 truncate_setsize(inode
, ia
->ia_size
);
870 lower_ia
->ia_size
= ia
->ia_size
;
871 lower_ia
->ia_valid
|= ATTR_SIZE
;
877 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
882 rc
= ecryptfs_write(inode
, zeros_virt
,
883 ia
->ia_size
, num_zeros
);
886 printk(KERN_ERR
"Error attempting to zero out "
887 "the remainder of the end page on "
888 "reducing truncate; rc = [%d]\n", rc
);
892 truncate_setsize(inode
, ia
->ia_size
);
893 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
895 printk(KERN_ERR
"Problem with "
896 "ecryptfs_write_inode_size_to_metadata; "
900 /* We are reducing the size of the ecryptfs file, and need to
901 * know if we need to reduce the size of the lower file. */
902 lower_size_before_truncate
=
903 upper_size_to_lower_size(crypt_stat
, i_size
);
904 lower_size_after_truncate
=
905 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
906 if (lower_size_after_truncate
< lower_size_before_truncate
) {
907 lower_ia
->ia_size
= lower_size_after_truncate
;
908 lower_ia
->ia_valid
|= ATTR_SIZE
;
910 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
913 ecryptfs_put_lower_file(inode
);
919 * @dentry: The ecryptfs layer dentry
920 * @new_length: The length to expand the file to
922 * Simple function that handles the truncation of an eCryptfs inode and
923 * its corresponding lower inode.
925 * Returns zero on success; non-zero otherwise
927 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
929 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
930 struct iattr lower_ia
= { .ia_valid
= 0 };
933 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
934 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
935 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
937 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
938 rc
= notify_change(lower_dentry
, &lower_ia
);
939 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
945 ecryptfs_permission(struct inode
*inode
, int mask
, unsigned int flags
)
947 if (flags
& IPERM_FLAG_RCU
)
949 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
954 * @dentry: dentry handle to the inode to modify
955 * @ia: Structure with flags of what to change and values
957 * Updates the metadata of an inode. If the update is to the size
958 * i.e. truncation, then ecryptfs_truncate will handle the size modification
959 * of both the ecryptfs inode and the lower inode.
961 * All other metadata changes will be passed right to the lower filesystem,
962 * and we will just update our inode to look like the lower.
964 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
967 struct dentry
*lower_dentry
;
968 struct iattr lower_ia
;
970 struct inode
*lower_inode
;
971 struct ecryptfs_crypt_stat
*crypt_stat
;
973 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
974 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
975 ecryptfs_init_crypt_stat(crypt_stat
);
976 inode
= dentry
->d_inode
;
977 lower_inode
= ecryptfs_inode_to_lower(inode
);
978 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
979 mutex_lock(&crypt_stat
->cs_mutex
);
980 if (S_ISDIR(dentry
->d_inode
->i_mode
))
981 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
982 else if (S_ISREG(dentry
->d_inode
->i_mode
)
983 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
984 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
985 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
987 mount_crypt_stat
= &ecryptfs_superblock_to_private(
988 dentry
->d_sb
)->mount_crypt_stat
;
989 rc
= ecryptfs_get_lower_file(dentry
, inode
);
991 mutex_unlock(&crypt_stat
->cs_mutex
);
994 rc
= ecryptfs_read_metadata(dentry
);
995 ecryptfs_put_lower_file(inode
);
997 if (!(mount_crypt_stat
->flags
998 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
1000 printk(KERN_WARNING
"Either the lower file "
1001 "is not in a valid eCryptfs format, "
1002 "or the key could not be retrieved. "
1003 "Plaintext passthrough mode is not "
1004 "enabled; returning -EIO\n");
1005 mutex_unlock(&crypt_stat
->cs_mutex
);
1009 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
1010 | ECRYPTFS_ENCRYPTED
);
1013 mutex_unlock(&crypt_stat
->cs_mutex
);
1014 if (S_ISREG(inode
->i_mode
)) {
1015 rc
= filemap_write_and_wait(inode
->i_mapping
);
1018 fsstack_copy_attr_all(inode
, lower_inode
);
1020 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
1021 if (ia
->ia_valid
& ATTR_FILE
)
1022 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
1023 if (ia
->ia_valid
& ATTR_SIZE
) {
1024 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1030 * mode change is for clearing setuid/setgid bits. Allow lower fs
1031 * to interpret this in its own way.
1033 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1034 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1036 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1037 rc
= notify_change(lower_dentry
, &lower_ia
);
1038 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1040 fsstack_copy_attr_all(inode
, lower_inode
);
1044 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1047 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1050 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1051 dentry
->d_sb
)->mount_crypt_stat
;
1052 generic_fillattr(dentry
->d_inode
, stat
);
1053 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1057 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1060 stat
->size
= targetsiz
;
1066 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1069 struct kstat lower_stat
;
1072 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1073 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1075 fsstack_copy_attr_all(dentry
->d_inode
,
1076 ecryptfs_inode_to_lower(dentry
->d_inode
));
1077 generic_fillattr(dentry
->d_inode
, stat
);
1078 stat
->blocks
= lower_stat
.blocks
;
1084 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1085 size_t size
, int flags
)
1088 struct dentry
*lower_dentry
;
1090 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1091 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1096 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1102 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1103 void *value
, size_t size
)
1107 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1111 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1112 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1114 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1120 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1123 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1128 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1131 struct dentry
*lower_dentry
;
1133 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1134 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1138 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1139 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1140 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1145 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1148 struct dentry
*lower_dentry
;
1150 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1151 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1155 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1156 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1157 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1162 const struct inode_operations ecryptfs_symlink_iops
= {
1163 .readlink
= ecryptfs_readlink
,
1164 .follow_link
= ecryptfs_follow_link
,
1165 .put_link
= ecryptfs_put_link
,
1166 .permission
= ecryptfs_permission
,
1167 .setattr
= ecryptfs_setattr
,
1168 .getattr
= ecryptfs_getattr_link
,
1169 .setxattr
= ecryptfs_setxattr
,
1170 .getxattr
= ecryptfs_getxattr
,
1171 .listxattr
= ecryptfs_listxattr
,
1172 .removexattr
= ecryptfs_removexattr
1175 const struct inode_operations ecryptfs_dir_iops
= {
1176 .create
= ecryptfs_create
,
1177 .lookup
= ecryptfs_lookup
,
1178 .link
= ecryptfs_link
,
1179 .unlink
= ecryptfs_unlink
,
1180 .symlink
= ecryptfs_symlink
,
1181 .mkdir
= ecryptfs_mkdir
,
1182 .rmdir
= ecryptfs_rmdir
,
1183 .mknod
= ecryptfs_mknod
,
1184 .rename
= ecryptfs_rename
,
1185 .permission
= ecryptfs_permission
,
1186 .setattr
= ecryptfs_setattr
,
1187 .setxattr
= ecryptfs_setxattr
,
1188 .getxattr
= ecryptfs_getxattr
,
1189 .listxattr
= ecryptfs_listxattr
,
1190 .removexattr
= ecryptfs_removexattr
1193 const struct inode_operations ecryptfs_main_iops
= {
1194 .permission
= ecryptfs_permission
,
1195 .setattr
= ecryptfs_setattr
,
1196 .getattr
= ecryptfs_getattr
,
1197 .setxattr
= ecryptfs_setxattr
,
1198 .getxattr
= ecryptfs_getxattr
,
1199 .listxattr
= ecryptfs_listxattr
,
1200 .removexattr
= ecryptfs_removexattr