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
);
311 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
313 static int ecryptfs_lookup_interpose(struct dentry
*ecryptfs_dentry
,
314 struct dentry
*lower_dentry
,
315 struct inode
*ecryptfs_dir_inode
)
317 struct dentry
*lower_dir_dentry
;
318 struct vfsmount
*lower_mnt
;
319 struct inode
*inode
, *lower_inode
;
320 struct ecryptfs_crypt_stat
*crypt_stat
;
321 char *page_virt
= NULL
;
322 int put_lower
= 0, rc
= 0;
324 lower_dir_dentry
= lower_dentry
->d_parent
;
325 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
326 ecryptfs_dentry
->d_parent
));
327 lower_inode
= lower_dentry
->d_inode
;
328 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
329 BUG_ON(!lower_dentry
->d_count
);
330 ecryptfs_set_dentry_private(ecryptfs_dentry
,
331 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
333 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
335 printk(KERN_ERR
"%s: Out of memory whilst attempting "
336 "to allocate ecryptfs_dentry_info struct\n",
340 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
341 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
342 if (!lower_dentry
->d_inode
) {
343 /* We want to add because we couldn't find in lower */
344 d_add(ecryptfs_dentry
, NULL
);
347 inode
= __ecryptfs_get_inode(lower_inode
, ecryptfs_dir_inode
->i_sb
);
350 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
354 if (!S_ISREG(inode
->i_mode
)) {
355 if (inode
->i_state
& I_NEW
)
356 unlock_new_inode(inode
);
357 d_add(ecryptfs_dentry
, inode
);
360 /* Released in this function */
361 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
363 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
366 make_bad_inode(inode
);
369 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, inode
);
371 printk(KERN_ERR
"%s: Error attempting to initialize "
372 "the lower file for the dentry with name "
373 "[%s]; rc = [%d]\n", __func__
,
374 ecryptfs_dentry
->d_name
.name
, rc
);
375 make_bad_inode(inode
);
379 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
380 /* TODO: lock for crypt_stat comparison */
381 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
382 ecryptfs_set_default_sizes(crypt_stat
);
383 rc
= ecryptfs_read_and_validate_header_region(page_virt
, inode
);
385 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
386 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
392 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
394 ecryptfs_i_size_init(page_virt
, inode
);
396 if (inode
->i_state
& I_NEW
)
397 unlock_new_inode(inode
);
398 d_add(ecryptfs_dentry
, inode
);
400 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
405 d_drop(ecryptfs_dentry
);
408 ecryptfs_put_lower_file(inode
);
414 * @ecryptfs_dir_inode: The eCryptfs directory inode
415 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
416 * @ecryptfs_nd: nameidata; may be NULL
418 * Find a file on disk. If the file does not exist, then we'll add it to the
419 * dentry cache and continue on to read it from the disk.
421 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
422 struct dentry
*ecryptfs_dentry
,
423 struct nameidata
*ecryptfs_nd
)
425 char *encrypted_and_encoded_name
= NULL
;
426 size_t encrypted_and_encoded_name_size
;
427 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
428 struct dentry
*lower_dir_dentry
, *lower_dentry
;
431 if ((ecryptfs_dentry
->d_name
.len
== 1
432 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
433 || (ecryptfs_dentry
->d_name
.len
== 2
434 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
437 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
438 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
439 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
441 ecryptfs_dentry
->d_name
.len
);
442 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
443 if (IS_ERR(lower_dentry
)) {
444 rc
= PTR_ERR(lower_dentry
);
445 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
446 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
447 encrypted_and_encoded_name
);
450 if (lower_dentry
->d_inode
)
452 mount_crypt_stat
= &ecryptfs_superblock_to_private(
453 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
454 if (!(mount_crypt_stat
455 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
458 rc
= ecryptfs_encrypt_and_encode_filename(
459 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
460 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
461 ecryptfs_dentry
->d_name
.len
);
463 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
464 "filename; rc = [%d]\n", __func__
, rc
);
467 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
468 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
470 encrypted_and_encoded_name_size
);
471 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
472 if (IS_ERR(lower_dentry
)) {
473 rc
= PTR_ERR(lower_dentry
);
474 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
475 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
476 encrypted_and_encoded_name
);
480 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
484 d_drop(ecryptfs_dentry
);
486 kfree(encrypted_and_encoded_name
);
490 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
491 struct dentry
*new_dentry
)
493 struct dentry
*lower_old_dentry
;
494 struct dentry
*lower_new_dentry
;
495 struct dentry
*lower_dir_dentry
;
499 file_size_save
= i_size_read(old_dentry
->d_inode
);
500 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
501 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
502 dget(lower_old_dentry
);
503 dget(lower_new_dentry
);
504 lower_dir_dentry
= lock_parent(lower_new_dentry
);
505 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
507 if (rc
|| !lower_new_dentry
->d_inode
)
509 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
512 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
513 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
514 old_dentry
->d_inode
->i_nlink
=
515 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
516 i_size_write(new_dentry
->d_inode
, file_size_save
);
518 unlock_dir(lower_dir_dentry
);
519 dput(lower_new_dentry
);
520 dput(lower_old_dentry
);
524 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
527 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
528 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
529 struct dentry
*lower_dir_dentry
;
532 lower_dir_dentry
= lock_parent(lower_dentry
);
533 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
535 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
538 fsstack_copy_attr_times(dir
, lower_dir_inode
);
539 dentry
->d_inode
->i_nlink
=
540 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
541 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
544 unlock_dir(lower_dir_dentry
);
549 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
553 struct dentry
*lower_dentry
;
554 struct dentry
*lower_dir_dentry
;
555 char *encoded_symname
;
556 size_t encoded_symlen
;
557 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
559 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
561 lower_dir_dentry
= lock_parent(lower_dentry
);
562 mount_crypt_stat
= &ecryptfs_superblock_to_private(
563 dir
->i_sb
)->mount_crypt_stat
;
564 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
567 mount_crypt_stat
, symname
,
571 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
573 kfree(encoded_symname
);
574 if (rc
|| !lower_dentry
->d_inode
)
576 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
579 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
580 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
582 unlock_dir(lower_dir_dentry
);
584 if (!dentry
->d_inode
)
589 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
592 struct dentry
*lower_dentry
;
593 struct dentry
*lower_dir_dentry
;
595 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
596 lower_dir_dentry
= lock_parent(lower_dentry
);
597 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
598 if (rc
|| !lower_dentry
->d_inode
)
600 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
603 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
604 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
605 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
607 unlock_dir(lower_dir_dentry
);
608 if (!dentry
->d_inode
)
613 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
615 struct dentry
*lower_dentry
;
616 struct dentry
*lower_dir_dentry
;
619 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
621 lower_dir_dentry
= lock_parent(lower_dentry
);
623 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
625 if (!rc
&& dentry
->d_inode
)
626 clear_nlink(dentry
->d_inode
);
627 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
628 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
629 unlock_dir(lower_dir_dentry
);
637 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
640 struct dentry
*lower_dentry
;
641 struct dentry
*lower_dir_dentry
;
643 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
644 lower_dir_dentry
= lock_parent(lower_dentry
);
645 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
646 if (rc
|| !lower_dentry
->d_inode
)
648 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
651 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
652 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
654 unlock_dir(lower_dir_dentry
);
655 if (!dentry
->d_inode
)
661 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
662 struct inode
*new_dir
, struct dentry
*new_dentry
)
665 struct dentry
*lower_old_dentry
;
666 struct dentry
*lower_new_dentry
;
667 struct dentry
*lower_old_dir_dentry
;
668 struct dentry
*lower_new_dir_dentry
;
669 struct dentry
*trap
= NULL
;
671 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
672 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
673 dget(lower_old_dentry
);
674 dget(lower_new_dentry
);
675 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
676 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
677 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
678 /* source should not be ancestor of target */
679 if (trap
== lower_old_dentry
) {
683 /* target should not be ancestor of source */
684 if (trap
== lower_new_dentry
) {
688 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
689 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
692 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
693 if (new_dir
!= old_dir
)
694 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
696 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
697 dput(lower_new_dir_dentry
);
698 dput(lower_old_dir_dentry
);
699 dput(lower_new_dentry
);
700 dput(lower_old_dentry
);
704 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
707 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
709 size_t lower_bufsiz
= PATH_MAX
;
713 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
720 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
721 (char __user
*)lower_buf
,
727 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
728 lower_buf
, lower_bufsiz
);
735 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
738 size_t kbufsiz
, copied
;
741 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
744 copied
= min_t(size_t, bufsiz
, kbufsiz
);
745 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
747 fsstack_copy_attr_atime(dentry
->d_inode
,
748 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
753 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
756 int len
= PAGE_SIZE
, rc
;
759 /* Released in ecryptfs_put_link(); only release here on error */
760 buf
= kmalloc(len
, GFP_KERNEL
);
762 buf
= ERR_PTR(-ENOMEM
);
767 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
775 nd_set_link(nd
, buf
);
780 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
782 char *buf
= nd_get_link(nd
);
790 * upper_size_to_lower_size
791 * @crypt_stat: Crypt_stat associated with file
792 * @upper_size: Size of the upper file
794 * Calculate the required size of the lower file based on the
795 * specified size of the upper file. This calculation is based on the
796 * number of headers in the underlying file and the extent size.
798 * Returns Calculated size of the lower file.
801 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
806 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
807 if (upper_size
!= 0) {
810 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
811 if (upper_size
& ~crypt_stat
->extent_mask
)
813 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
820 * @dentry: The ecryptfs layer dentry
821 * @ia: Address of the ecryptfs inode's attributes
822 * @lower_ia: Address of the lower inode's attributes
824 * Function to handle truncations modifying the size of the file. Note
825 * that the file sizes are interpolated. When expanding, we are simply
826 * writing strings of 0's out. When truncating, we truncate the upper
827 * inode and update the lower_ia according to the page index
828 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
829 * the caller must use lower_ia in a call to notify_change() to perform
830 * the truncation of the lower inode.
832 * Returns zero on success; non-zero otherwise
834 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
835 struct iattr
*lower_ia
)
838 struct inode
*inode
= dentry
->d_inode
;
839 struct ecryptfs_crypt_stat
*crypt_stat
;
840 loff_t i_size
= i_size_read(inode
);
841 loff_t lower_size_before_truncate
;
842 loff_t lower_size_after_truncate
;
844 if (unlikely((ia
->ia_size
== i_size
))) {
845 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
848 rc
= ecryptfs_get_lower_file(dentry
, inode
);
851 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
852 /* Switch on growing or shrinking file */
853 if (ia
->ia_size
> i_size
) {
854 char zero
[] = { 0x00 };
856 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
857 /* Write a single 0 at the last position of the file;
858 * this triggers code that will fill in 0's throughout
859 * the intermediate portion of the previous end of the
860 * file and the new and of the file */
861 rc
= ecryptfs_write(inode
, zero
,
862 (ia
->ia_size
- 1), 1);
863 } else { /* ia->ia_size < i_size_read(inode) */
864 /* We're chopping off all the pages down to the page
865 * in which ia->ia_size is located. Fill in the end of
866 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
867 * PAGE_CACHE_SIZE with zeros. */
868 size_t num_zeros
= (PAGE_CACHE_SIZE
869 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
873 * XXX(truncate) this should really happen at the begginning
874 * of ->setattr. But the code is too messy to that as part
875 * of a larger patch. ecryptfs is also totally missing out
876 * on the inode_change_ok check at the beginning of
877 * ->setattr while would include this.
879 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
883 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
884 truncate_setsize(inode
, ia
->ia_size
);
885 lower_ia
->ia_size
= ia
->ia_size
;
886 lower_ia
->ia_valid
|= ATTR_SIZE
;
892 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
897 rc
= ecryptfs_write(inode
, zeros_virt
,
898 ia
->ia_size
, num_zeros
);
901 printk(KERN_ERR
"Error attempting to zero out "
902 "the remainder of the end page on "
903 "reducing truncate; rc = [%d]\n", rc
);
907 truncate_setsize(inode
, ia
->ia_size
);
908 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
910 printk(KERN_ERR
"Problem with "
911 "ecryptfs_write_inode_size_to_metadata; "
915 /* We are reducing the size of the ecryptfs file, and need to
916 * know if we need to reduce the size of the lower file. */
917 lower_size_before_truncate
=
918 upper_size_to_lower_size(crypt_stat
, i_size
);
919 lower_size_after_truncate
=
920 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
921 if (lower_size_after_truncate
< lower_size_before_truncate
) {
922 lower_ia
->ia_size
= lower_size_after_truncate
;
923 lower_ia
->ia_valid
|= ATTR_SIZE
;
925 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
928 ecryptfs_put_lower_file(inode
);
934 * @dentry: The ecryptfs layer dentry
935 * @new_length: The length to expand the file to
937 * Simple function that handles the truncation of an eCryptfs inode and
938 * its corresponding lower inode.
940 * Returns zero on success; non-zero otherwise
942 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
944 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
945 struct iattr lower_ia
= { .ia_valid
= 0 };
948 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
949 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
950 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
952 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
953 rc
= notify_change(lower_dentry
, &lower_ia
);
954 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
960 ecryptfs_permission(struct inode
*inode
, int mask
, unsigned int flags
)
962 if (flags
& IPERM_FLAG_RCU
)
964 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
969 * @dentry: dentry handle to the inode to modify
970 * @ia: Structure with flags of what to change and values
972 * Updates the metadata of an inode. If the update is to the size
973 * i.e. truncation, then ecryptfs_truncate will handle the size modification
974 * of both the ecryptfs inode and the lower inode.
976 * All other metadata changes will be passed right to the lower filesystem,
977 * and we will just update our inode to look like the lower.
979 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
982 struct dentry
*lower_dentry
;
983 struct iattr lower_ia
;
985 struct inode
*lower_inode
;
986 struct ecryptfs_crypt_stat
*crypt_stat
;
988 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
989 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
990 ecryptfs_init_crypt_stat(crypt_stat
);
991 inode
= dentry
->d_inode
;
992 lower_inode
= ecryptfs_inode_to_lower(inode
);
993 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
994 mutex_lock(&crypt_stat
->cs_mutex
);
995 if (S_ISDIR(dentry
->d_inode
->i_mode
))
996 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
997 else if (S_ISREG(dentry
->d_inode
->i_mode
)
998 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
999 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
1000 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1002 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1003 dentry
->d_sb
)->mount_crypt_stat
;
1004 rc
= ecryptfs_get_lower_file(dentry
, inode
);
1006 mutex_unlock(&crypt_stat
->cs_mutex
);
1009 rc
= ecryptfs_read_metadata(dentry
);
1010 ecryptfs_put_lower_file(inode
);
1012 if (!(mount_crypt_stat
->flags
1013 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
1015 printk(KERN_WARNING
"Either the lower file "
1016 "is not in a valid eCryptfs format, "
1017 "or the key could not be retrieved. "
1018 "Plaintext passthrough mode is not "
1019 "enabled; returning -EIO\n");
1020 mutex_unlock(&crypt_stat
->cs_mutex
);
1024 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
1025 | ECRYPTFS_ENCRYPTED
);
1028 mutex_unlock(&crypt_stat
->cs_mutex
);
1029 if (S_ISREG(inode
->i_mode
)) {
1030 rc
= filemap_write_and_wait(inode
->i_mapping
);
1033 fsstack_copy_attr_all(inode
, lower_inode
);
1035 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
1036 if (ia
->ia_valid
& ATTR_FILE
)
1037 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
1038 if (ia
->ia_valid
& ATTR_SIZE
) {
1039 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1045 * mode change is for clearing setuid/setgid bits. Allow lower fs
1046 * to interpret this in its own way.
1048 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1049 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1051 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1052 rc
= notify_change(lower_dentry
, &lower_ia
);
1053 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1055 fsstack_copy_attr_all(inode
, lower_inode
);
1059 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1062 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1065 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1066 dentry
->d_sb
)->mount_crypt_stat
;
1067 generic_fillattr(dentry
->d_inode
, stat
);
1068 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1072 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1075 stat
->size
= targetsiz
;
1081 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1084 struct kstat lower_stat
;
1087 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1088 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1090 fsstack_copy_attr_all(dentry
->d_inode
,
1091 ecryptfs_inode_to_lower(dentry
->d_inode
));
1092 generic_fillattr(dentry
->d_inode
, stat
);
1093 stat
->blocks
= lower_stat
.blocks
;
1099 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1100 size_t size
, int flags
)
1103 struct dentry
*lower_dentry
;
1105 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1106 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1111 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1117 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1118 void *value
, size_t size
)
1122 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1126 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1127 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1129 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1135 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1138 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1143 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1146 struct dentry
*lower_dentry
;
1148 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1149 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1153 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1154 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1155 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1160 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1163 struct dentry
*lower_dentry
;
1165 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1166 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1170 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1171 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1172 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1177 const struct inode_operations ecryptfs_symlink_iops
= {
1178 .readlink
= ecryptfs_readlink
,
1179 .follow_link
= ecryptfs_follow_link
,
1180 .put_link
= ecryptfs_put_link
,
1181 .permission
= ecryptfs_permission
,
1182 .setattr
= ecryptfs_setattr
,
1183 .getattr
= ecryptfs_getattr_link
,
1184 .setxattr
= ecryptfs_setxattr
,
1185 .getxattr
= ecryptfs_getxattr
,
1186 .listxattr
= ecryptfs_listxattr
,
1187 .removexattr
= ecryptfs_removexattr
1190 const struct inode_operations ecryptfs_dir_iops
= {
1191 .create
= ecryptfs_create
,
1192 .lookup
= ecryptfs_lookup
,
1193 .link
= ecryptfs_link
,
1194 .unlink
= ecryptfs_unlink
,
1195 .symlink
= ecryptfs_symlink
,
1196 .mkdir
= ecryptfs_mkdir
,
1197 .rmdir
= ecryptfs_rmdir
,
1198 .mknod
= ecryptfs_mknod
,
1199 .rename
= ecryptfs_rename
,
1200 .permission
= ecryptfs_permission
,
1201 .setattr
= ecryptfs_setattr
,
1202 .setxattr
= ecryptfs_setxattr
,
1203 .getxattr
= ecryptfs_getxattr
,
1204 .listxattr
= ecryptfs_listxattr
,
1205 .removexattr
= ecryptfs_removexattr
1208 const struct inode_operations ecryptfs_main_iops
= {
1209 .permission
= ecryptfs_permission
,
1210 .setattr
= ecryptfs_setattr
,
1211 .getattr
= ecryptfs_getattr
,
1212 .setxattr
= ecryptfs_setxattr
,
1213 .getxattr
= ecryptfs_getxattr
,
1214 .listxattr
= ecryptfs_listxattr
,
1215 .removexattr
= ecryptfs_removexattr