2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry
*lock_parent(struct dentry
*dentry
)
43 dir
= dget_parent(dentry
);
44 mutex_lock_nested(&(dir
->d_inode
->i_mutex
), I_MUTEX_PARENT
);
48 static void unlock_dir(struct dentry
*dir
)
50 mutex_unlock(&dir
->d_inode
->i_mutex
);
54 static int ecryptfs_inode_test(struct inode
*inode
, void *lower_inode
)
56 if (ecryptfs_inode_to_lower(inode
) == (struct inode
*)lower_inode
)
61 static int ecryptfs_inode_set(struct inode
*inode
, void *opaque
)
63 struct inode
*lower_inode
= opaque
;
65 ecryptfs_set_inode_lower(inode
, lower_inode
);
66 fsstack_copy_attr_all(inode
, lower_inode
);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode
, lower_inode
);
69 inode
->i_ino
= lower_inode
->i_ino
;
71 inode
->i_mapping
->a_ops
= &ecryptfs_aops
;
72 inode
->i_mapping
->backing_dev_info
= inode
->i_sb
->s_bdi
;
74 if (S_ISLNK(inode
->i_mode
))
75 inode
->i_op
= &ecryptfs_symlink_iops
;
76 else if (S_ISDIR(inode
->i_mode
))
77 inode
->i_op
= &ecryptfs_dir_iops
;
79 inode
->i_op
= &ecryptfs_main_iops
;
81 if (S_ISDIR(inode
->i_mode
))
82 inode
->i_fop
= &ecryptfs_dir_fops
;
83 else if (special_file(inode
->i_mode
))
84 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
86 inode
->i_fop
= &ecryptfs_main_fops
;
91 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
92 struct super_block
*sb
)
96 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
97 return ERR_PTR(-EXDEV
);
98 if (!igrab(lower_inode
))
99 return ERR_PTR(-ESTALE
);
100 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
101 ecryptfs_inode_test
, ecryptfs_inode_set
,
105 return ERR_PTR(-EACCES
);
107 if (!(inode
->i_state
& I_NEW
))
113 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
114 struct super_block
*sb
)
116 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
118 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
119 unlock_new_inode(inode
);
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
130 * Interposes upper and lower dentries.
132 * Returns zero on success; non-zero otherwise
134 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
135 struct dentry
*dentry
, struct super_block
*sb
)
137 struct inode
*inode
= ecryptfs_get_inode(lower_dentry
->d_inode
, sb
);
140 return PTR_ERR(inode
);
141 d_instantiate(dentry
, inode
);
146 static int ecryptfs_do_unlink(struct inode
*dir
, struct dentry
*dentry
,
149 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
150 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
151 struct dentry
*lower_dir_dentry
;
155 lower_dir_dentry
= lock_parent(lower_dentry
);
156 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
158 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
161 fsstack_copy_attr_times(dir
, lower_dir_inode
);
162 set_nlink(inode
, ecryptfs_inode_to_lower(inode
)->i_nlink
);
163 inode
->i_ctime
= dir
->i_ctime
;
166 unlock_dir(lower_dir_dentry
);
173 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
174 * @ecryptfs_dentry: New file's dentry in ecryptfs
175 * @mode: The mode of the new file
176 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
178 * Creates the underlying file and the eCryptfs inode which will link to
179 * it. It will also update the eCryptfs directory inode to mimic the
180 * stat of the lower directory inode.
182 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
184 static struct inode
*
185 ecryptfs_do_create(struct inode
*directory_inode
,
186 struct dentry
*ecryptfs_dentry
, umode_t mode
)
189 struct dentry
*lower_dentry
;
190 struct dentry
*lower_dir_dentry
;
193 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
194 lower_dir_dentry
= lock_parent(lower_dentry
);
195 if (IS_ERR(lower_dir_dentry
)) {
196 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
198 inode
= ERR_CAST(lower_dir_dentry
);
201 rc
= vfs_create(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, true);
203 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
204 "rc = [%d]\n", __func__
, rc
);
208 inode
= __ecryptfs_get_inode(lower_dentry
->d_inode
,
209 directory_inode
->i_sb
);
211 vfs_unlink(lower_dir_dentry
->d_inode
, lower_dentry
);
214 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
215 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
217 unlock_dir(lower_dir_dentry
);
223 * ecryptfs_initialize_file
225 * Cause the file to be changed from a basic empty file to an ecryptfs
226 * file with a header and first data page.
228 * Returns zero on success
230 int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
231 struct inode
*ecryptfs_inode
)
233 struct ecryptfs_crypt_stat
*crypt_stat
=
234 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
237 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
238 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
239 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
242 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
243 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
245 ecryptfs_printk(KERN_ERR
, "Error creating new file "
246 "context; rc = [%d]\n", rc
);
249 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
251 printk(KERN_ERR
"%s: Error attempting to initialize "
252 "the lower file for the dentry with name "
253 "[%s]; rc = [%d]\n", __func__
,
254 ecryptfs_dentry
->d_name
.name
, rc
);
257 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
259 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
260 ecryptfs_put_lower_file(ecryptfs_inode
);
267 * @dir: The inode of the directory in which to create the file.
268 * @dentry: The eCryptfs dentry
269 * @mode: The mode of the new file.
271 * Creates a new file.
273 * Returns zero on success; non-zero on error condition
276 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
277 umode_t mode
, bool excl
)
279 struct inode
*ecryptfs_inode
;
282 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
284 if (unlikely(IS_ERR(ecryptfs_inode
))) {
285 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
286 "lower filesystem\n");
287 rc
= PTR_ERR(ecryptfs_inode
);
290 /* At this point, a file exists on "disk"; we need to make sure
291 * that this on disk file is prepared to be an ecryptfs file */
292 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
294 ecryptfs_do_unlink(directory_inode
, ecryptfs_dentry
,
296 make_bad_inode(ecryptfs_inode
);
297 unlock_new_inode(ecryptfs_inode
);
298 iput(ecryptfs_inode
);
301 unlock_new_inode(ecryptfs_inode
);
302 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
307 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
309 struct ecryptfs_crypt_stat
*crypt_stat
;
312 rc
= ecryptfs_get_lower_file(dentry
, inode
);
314 printk(KERN_ERR
"%s: Error attempting to initialize "
315 "the lower file for the dentry with name "
316 "[%s]; rc = [%d]\n", __func__
,
317 dentry
->d_name
.name
, rc
);
321 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
322 /* TODO: lock for crypt_stat comparison */
323 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
324 ecryptfs_set_default_sizes(crypt_stat
);
326 rc
= ecryptfs_read_and_validate_header_region(inode
);
327 ecryptfs_put_lower_file(inode
);
329 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
331 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
334 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
339 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
341 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
342 struct dentry
*lower_dentry
,
343 struct inode
*dir_inode
)
345 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
346 struct ecryptfs_dentry_info
*dentry_info
;
347 struct vfsmount
*lower_mnt
;
350 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
352 printk(KERN_ERR
"%s: Out of memory whilst attempting "
353 "to allocate ecryptfs_dentry_info struct\n",
359 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
360 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
361 BUG_ON(!d_count(lower_dentry
));
363 ecryptfs_set_dentry_private(dentry
, dentry_info
);
364 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
365 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
367 if (!lower_dentry
->d_inode
) {
368 /* We want to add because we couldn't find in lower */
372 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
374 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
375 __func__
, PTR_ERR(inode
));
376 return PTR_ERR(inode
);
378 if (S_ISREG(inode
->i_mode
)) {
379 rc
= ecryptfs_i_size_read(dentry
, inode
);
381 make_bad_inode(inode
);
386 if (inode
->i_state
& I_NEW
)
387 unlock_new_inode(inode
);
388 d_add(dentry
, inode
);
395 * @ecryptfs_dir_inode: The eCryptfs directory inode
396 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
397 * @ecryptfs_nd: nameidata; may be NULL
399 * Find a file on disk. If the file does not exist, then we'll add it to the
400 * dentry cache and continue on to read it from the disk.
402 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
403 struct dentry
*ecryptfs_dentry
,
406 char *encrypted_and_encoded_name
= NULL
;
407 size_t encrypted_and_encoded_name_size
;
408 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
409 struct dentry
*lower_dir_dentry
, *lower_dentry
;
412 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
413 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
414 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
416 ecryptfs_dentry
->d_name
.len
);
417 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
418 if (IS_ERR(lower_dentry
)) {
419 rc
= PTR_ERR(lower_dentry
);
420 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
421 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
422 ecryptfs_dentry
->d_name
.name
);
425 if (lower_dentry
->d_inode
)
427 mount_crypt_stat
= &ecryptfs_superblock_to_private(
428 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
429 if (!(mount_crypt_stat
430 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
433 rc
= ecryptfs_encrypt_and_encode_filename(
434 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
435 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
436 ecryptfs_dentry
->d_name
.len
);
438 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
439 "filename; rc = [%d]\n", __func__
, rc
);
442 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
443 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
445 encrypted_and_encoded_name_size
);
446 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
447 if (IS_ERR(lower_dentry
)) {
448 rc
= PTR_ERR(lower_dentry
);
449 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
450 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
451 encrypted_and_encoded_name
);
455 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
458 kfree(encrypted_and_encoded_name
);
462 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
463 struct dentry
*new_dentry
)
465 struct dentry
*lower_old_dentry
;
466 struct dentry
*lower_new_dentry
;
467 struct dentry
*lower_dir_dentry
;
471 file_size_save
= i_size_read(old_dentry
->d_inode
);
472 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
473 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
474 dget(lower_old_dentry
);
475 dget(lower_new_dentry
);
476 lower_dir_dentry
= lock_parent(lower_new_dentry
);
477 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
479 if (rc
|| !lower_new_dentry
->d_inode
)
481 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
484 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
485 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
486 set_nlink(old_dentry
->d_inode
,
487 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
);
488 i_size_write(new_dentry
->d_inode
, file_size_save
);
490 unlock_dir(lower_dir_dentry
);
491 dput(lower_new_dentry
);
492 dput(lower_old_dentry
);
496 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
498 return ecryptfs_do_unlink(dir
, dentry
, dentry
->d_inode
);
501 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
505 struct dentry
*lower_dentry
;
506 struct dentry
*lower_dir_dentry
;
507 char *encoded_symname
;
508 size_t encoded_symlen
;
509 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
511 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
513 lower_dir_dentry
= lock_parent(lower_dentry
);
514 mount_crypt_stat
= &ecryptfs_superblock_to_private(
515 dir
->i_sb
)->mount_crypt_stat
;
516 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
519 mount_crypt_stat
, symname
,
523 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
525 kfree(encoded_symname
);
526 if (rc
|| !lower_dentry
->d_inode
)
528 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
531 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
532 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
534 unlock_dir(lower_dir_dentry
);
536 if (!dentry
->d_inode
)
541 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
544 struct dentry
*lower_dentry
;
545 struct dentry
*lower_dir_dentry
;
547 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
548 lower_dir_dentry
= lock_parent(lower_dentry
);
549 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
550 if (rc
|| !lower_dentry
->d_inode
)
552 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
555 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
556 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
557 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
559 unlock_dir(lower_dir_dentry
);
560 if (!dentry
->d_inode
)
565 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
567 struct dentry
*lower_dentry
;
568 struct dentry
*lower_dir_dentry
;
571 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
573 lower_dir_dentry
= lock_parent(lower_dentry
);
575 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
577 if (!rc
&& dentry
->d_inode
)
578 clear_nlink(dentry
->d_inode
);
579 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
580 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
581 unlock_dir(lower_dir_dentry
);
589 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
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_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
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
);
606 unlock_dir(lower_dir_dentry
);
607 if (!dentry
->d_inode
)
613 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
614 struct inode
*new_dir
, struct dentry
*new_dentry
)
617 struct dentry
*lower_old_dentry
;
618 struct dentry
*lower_new_dentry
;
619 struct dentry
*lower_old_dir_dentry
;
620 struct dentry
*lower_new_dir_dentry
;
621 struct dentry
*trap
= NULL
;
622 struct inode
*target_inode
;
624 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
625 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
626 dget(lower_old_dentry
);
627 dget(lower_new_dentry
);
628 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
629 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
630 target_inode
= new_dentry
->d_inode
;
631 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
632 /* source should not be ancestor of target */
633 if (trap
== lower_old_dentry
) {
637 /* target should not be ancestor of source */
638 if (trap
== lower_new_dentry
) {
642 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
643 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
647 fsstack_copy_attr_all(target_inode
,
648 ecryptfs_inode_to_lower(target_inode
));
649 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
650 if (new_dir
!= old_dir
)
651 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
653 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
654 dput(lower_new_dir_dentry
);
655 dput(lower_old_dir_dentry
);
656 dput(lower_new_dentry
);
657 dput(lower_old_dentry
);
661 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
664 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
669 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
676 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
677 (char __user
*)lower_buf
,
682 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
->d_sb
,
689 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
692 size_t len
= PATH_MAX
;
695 rc
= ecryptfs_readlink_lower(dentry
, &buf
, &len
);
698 fsstack_copy_attr_atime(dentry
->d_inode
,
699 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
702 nd_set_link(nd
, buf
);
707 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
709 char *buf
= nd_get_link(nd
);
717 * upper_size_to_lower_size
718 * @crypt_stat: Crypt_stat associated with file
719 * @upper_size: Size of the upper file
721 * Calculate the required size of the lower file based on the
722 * specified size of the upper file. This calculation is based on the
723 * number of headers in the underlying file and the extent size.
725 * Returns Calculated size of the lower file.
728 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
733 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
734 if (upper_size
!= 0) {
737 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
738 if (upper_size
& ~crypt_stat
->extent_mask
)
740 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
747 * @dentry: The ecryptfs layer dentry
748 * @ia: Address of the ecryptfs inode's attributes
749 * @lower_ia: Address of the lower inode's attributes
751 * Function to handle truncations modifying the size of the file. Note
752 * that the file sizes are interpolated. When expanding, we are simply
753 * writing strings of 0's out. When truncating, we truncate the upper
754 * inode and update the lower_ia according to the page index
755 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
756 * the caller must use lower_ia in a call to notify_change() to perform
757 * the truncation of the lower inode.
759 * Returns zero on success; non-zero otherwise
761 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
762 struct iattr
*lower_ia
)
765 struct inode
*inode
= dentry
->d_inode
;
766 struct ecryptfs_crypt_stat
*crypt_stat
;
767 loff_t i_size
= i_size_read(inode
);
768 loff_t lower_size_before_truncate
;
769 loff_t lower_size_after_truncate
;
771 if (unlikely((ia
->ia_size
== i_size
))) {
772 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
775 rc
= ecryptfs_get_lower_file(dentry
, inode
);
778 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
779 /* Switch on growing or shrinking file */
780 if (ia
->ia_size
> i_size
) {
781 char zero
[] = { 0x00 };
783 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
784 /* Write a single 0 at the last position of the file;
785 * this triggers code that will fill in 0's throughout
786 * the intermediate portion of the previous end of the
787 * file and the new and of the file */
788 rc
= ecryptfs_write(inode
, zero
,
789 (ia
->ia_size
- 1), 1);
790 } else { /* ia->ia_size < i_size_read(inode) */
791 /* We're chopping off all the pages down to the page
792 * in which ia->ia_size is located. Fill in the end of
793 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
794 * PAGE_CACHE_SIZE with zeros. */
795 size_t num_zeros
= (PAGE_CACHE_SIZE
796 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
798 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
799 truncate_setsize(inode
, ia
->ia_size
);
800 lower_ia
->ia_size
= ia
->ia_size
;
801 lower_ia
->ia_valid
|= ATTR_SIZE
;
807 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
812 rc
= ecryptfs_write(inode
, zeros_virt
,
813 ia
->ia_size
, num_zeros
);
816 printk(KERN_ERR
"Error attempting to zero out "
817 "the remainder of the end page on "
818 "reducing truncate; rc = [%d]\n", rc
);
822 truncate_setsize(inode
, ia
->ia_size
);
823 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
825 printk(KERN_ERR
"Problem with "
826 "ecryptfs_write_inode_size_to_metadata; "
830 /* We are reducing the size of the ecryptfs file, and need to
831 * know if we need to reduce the size of the lower file. */
832 lower_size_before_truncate
=
833 upper_size_to_lower_size(crypt_stat
, i_size
);
834 lower_size_after_truncate
=
835 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
836 if (lower_size_after_truncate
< lower_size_before_truncate
) {
837 lower_ia
->ia_size
= lower_size_after_truncate
;
838 lower_ia
->ia_valid
|= ATTR_SIZE
;
840 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
843 ecryptfs_put_lower_file(inode
);
847 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
849 struct ecryptfs_crypt_stat
*crypt_stat
;
850 loff_t lower_oldsize
, lower_newsize
;
852 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
853 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
855 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
856 if (lower_newsize
> lower_oldsize
) {
858 * The eCryptfs inode and the new *lower* size are mixed here
859 * because we may not have the lower i_mutex held and/or it may
860 * not be appropriate to call inode_newsize_ok() with inodes
861 * from other filesystems.
863 return inode_newsize_ok(inode
, lower_newsize
);
871 * @dentry: The ecryptfs layer dentry
872 * @new_length: The length to expand the file to
874 * Simple function that handles the truncation of an eCryptfs inode and
875 * its corresponding lower inode.
877 * Returns zero on success; non-zero otherwise
879 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
881 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
882 struct iattr lower_ia
= { .ia_valid
= 0 };
885 rc
= ecryptfs_inode_newsize_ok(dentry
->d_inode
, new_length
);
889 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
890 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
891 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
893 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
894 rc
= notify_change(lower_dentry
, &lower_ia
);
895 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
901 ecryptfs_permission(struct inode
*inode
, int mask
)
903 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
908 * @dentry: dentry handle to the inode to modify
909 * @ia: Structure with flags of what to change and values
911 * Updates the metadata of an inode. If the update is to the size
912 * i.e. truncation, then ecryptfs_truncate will handle the size modification
913 * of both the ecryptfs inode and the lower inode.
915 * All other metadata changes will be passed right to the lower filesystem,
916 * and we will just update our inode to look like the lower.
918 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
921 struct dentry
*lower_dentry
;
922 struct iattr lower_ia
;
924 struct inode
*lower_inode
;
925 struct ecryptfs_crypt_stat
*crypt_stat
;
927 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
928 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
929 ecryptfs_init_crypt_stat(crypt_stat
);
930 inode
= dentry
->d_inode
;
931 lower_inode
= ecryptfs_inode_to_lower(inode
);
932 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
933 mutex_lock(&crypt_stat
->cs_mutex
);
934 if (S_ISDIR(dentry
->d_inode
->i_mode
))
935 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
936 else if (S_ISREG(dentry
->d_inode
->i_mode
)
937 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
938 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
939 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
941 mount_crypt_stat
= &ecryptfs_superblock_to_private(
942 dentry
->d_sb
)->mount_crypt_stat
;
943 rc
= ecryptfs_get_lower_file(dentry
, inode
);
945 mutex_unlock(&crypt_stat
->cs_mutex
);
948 rc
= ecryptfs_read_metadata(dentry
);
949 ecryptfs_put_lower_file(inode
);
951 if (!(mount_crypt_stat
->flags
952 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
954 printk(KERN_WARNING
"Either the lower file "
955 "is not in a valid eCryptfs format, "
956 "or the key could not be retrieved. "
957 "Plaintext passthrough mode is not "
958 "enabled; returning -EIO\n");
959 mutex_unlock(&crypt_stat
->cs_mutex
);
963 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
964 | ECRYPTFS_ENCRYPTED
);
967 mutex_unlock(&crypt_stat
->cs_mutex
);
969 rc
= inode_change_ok(inode
, ia
);
972 if (ia
->ia_valid
& ATTR_SIZE
) {
973 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
978 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
979 if (ia
->ia_valid
& ATTR_FILE
)
980 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
981 if (ia
->ia_valid
& ATTR_SIZE
) {
982 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
988 * mode change is for clearing setuid/setgid bits. Allow lower fs
989 * to interpret this in its own way.
991 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
992 lower_ia
.ia_valid
&= ~ATTR_MODE
;
994 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
995 rc
= notify_change(lower_dentry
, &lower_ia
);
996 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
998 fsstack_copy_attr_all(inode
, lower_inode
);
1002 static int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1005 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1008 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1009 dentry
->d_sb
)->mount_crypt_stat
;
1010 generic_fillattr(dentry
->d_inode
, stat
);
1011 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1015 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1018 stat
->size
= targetsiz
;
1024 static int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1027 struct kstat lower_stat
;
1030 rc
= vfs_getattr(ecryptfs_dentry_to_lower_path(dentry
), &lower_stat
);
1032 fsstack_copy_attr_all(dentry
->d_inode
,
1033 ecryptfs_inode_to_lower(dentry
->d_inode
));
1034 generic_fillattr(dentry
->d_inode
, stat
);
1035 stat
->blocks
= lower_stat
.blocks
;
1041 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1042 size_t size
, int flags
)
1045 struct dentry
*lower_dentry
;
1047 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1048 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1053 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1055 fsstack_copy_attr_all(dentry
->d_inode
, lower_dentry
->d_inode
);
1061 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1062 void *value
, size_t size
)
1066 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1070 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1071 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1073 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1079 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1082 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1087 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1090 struct dentry
*lower_dentry
;
1092 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1093 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1097 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1098 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1099 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1104 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1107 struct dentry
*lower_dentry
;
1109 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1110 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1114 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1115 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1116 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1121 const struct inode_operations ecryptfs_symlink_iops
= {
1122 .readlink
= generic_readlink
,
1123 .follow_link
= ecryptfs_follow_link
,
1124 .put_link
= ecryptfs_put_link
,
1125 .permission
= ecryptfs_permission
,
1126 .setattr
= ecryptfs_setattr
,
1127 .getattr
= ecryptfs_getattr_link
,
1128 .setxattr
= ecryptfs_setxattr
,
1129 .getxattr
= ecryptfs_getxattr
,
1130 .listxattr
= ecryptfs_listxattr
,
1131 .removexattr
= ecryptfs_removexattr
1134 const struct inode_operations ecryptfs_dir_iops
= {
1135 .create
= ecryptfs_create
,
1136 .lookup
= ecryptfs_lookup
,
1137 .link
= ecryptfs_link
,
1138 .unlink
= ecryptfs_unlink
,
1139 .symlink
= ecryptfs_symlink
,
1140 .mkdir
= ecryptfs_mkdir
,
1141 .rmdir
= ecryptfs_rmdir
,
1142 .mknod
= ecryptfs_mknod
,
1143 .rename
= ecryptfs_rename
,
1144 .permission
= ecryptfs_permission
,
1145 .setattr
= ecryptfs_setattr
,
1146 .setxattr
= ecryptfs_setxattr
,
1147 .getxattr
= ecryptfs_getxattr
,
1148 .listxattr
= ecryptfs_listxattr
,
1149 .removexattr
= ecryptfs_removexattr
1152 const struct inode_operations ecryptfs_main_iops
= {
1153 .permission
= ecryptfs_permission
,
1154 .setattr
= ecryptfs_setattr
,
1155 .getattr
= ecryptfs_getattr
,
1156 .setxattr
= ecryptfs_setxattr
,
1157 .getxattr
= ecryptfs_getxattr
,
1158 .listxattr
= ecryptfs_listxattr
,
1159 .removexattr
= ecryptfs_removexattr