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
, NULL
);
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
, NULL
);
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 dentry_info
->lower_path
.mnt
= lower_mnt
;
365 dentry_info
->lower_path
.dentry
= lower_dentry
;
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
,
478 lower_new_dentry
, NULL
);
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
,
648 fsstack_copy_attr_all(target_inode
,
649 ecryptfs_inode_to_lower(target_inode
));
650 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
651 if (new_dir
!= old_dir
)
652 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
654 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
655 dput(lower_new_dir_dentry
);
656 dput(lower_old_dir_dentry
);
657 dput(lower_new_dentry
);
658 dput(lower_old_dentry
);
662 static char *ecryptfs_readlink_lower(struct dentry
*dentry
, size_t *bufsiz
)
664 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
670 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
672 return ERR_PTR(-ENOMEM
);
675 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
676 (char __user
*)lower_buf
,
681 rc
= ecryptfs_decode_and_decrypt_filename(&buf
, bufsiz
, dentry
->d_sb
,
685 return rc
? ERR_PTR(rc
) : buf
;
688 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
691 char *buf
= ecryptfs_readlink_lower(dentry
, &len
);
694 fsstack_copy_attr_atime(dentry
->d_inode
,
695 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
698 nd_set_link(nd
, buf
);
703 * upper_size_to_lower_size
704 * @crypt_stat: Crypt_stat associated with file
705 * @upper_size: Size of the upper file
707 * Calculate the required size of the lower file based on the
708 * specified size of the upper file. This calculation is based on the
709 * number of headers in the underlying file and the extent size.
711 * Returns Calculated size of the lower file.
714 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
719 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
720 if (upper_size
!= 0) {
723 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
724 if (upper_size
& ~crypt_stat
->extent_mask
)
726 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
733 * @dentry: The ecryptfs layer dentry
734 * @ia: Address of the ecryptfs inode's attributes
735 * @lower_ia: Address of the lower inode's attributes
737 * Function to handle truncations modifying the size of the file. Note
738 * that the file sizes are interpolated. When expanding, we are simply
739 * writing strings of 0's out. When truncating, we truncate the upper
740 * inode and update the lower_ia according to the page index
741 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
742 * the caller must use lower_ia in a call to notify_change() to perform
743 * the truncation of the lower inode.
745 * Returns zero on success; non-zero otherwise
747 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
748 struct iattr
*lower_ia
)
751 struct inode
*inode
= dentry
->d_inode
;
752 struct ecryptfs_crypt_stat
*crypt_stat
;
753 loff_t i_size
= i_size_read(inode
);
754 loff_t lower_size_before_truncate
;
755 loff_t lower_size_after_truncate
;
757 if (unlikely((ia
->ia_size
== i_size
))) {
758 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
761 rc
= ecryptfs_get_lower_file(dentry
, inode
);
764 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
765 /* Switch on growing or shrinking file */
766 if (ia
->ia_size
> i_size
) {
767 char zero
[] = { 0x00 };
769 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
770 /* Write a single 0 at the last position of the file;
771 * this triggers code that will fill in 0's throughout
772 * the intermediate portion of the previous end of the
773 * file and the new and of the file */
774 rc
= ecryptfs_write(inode
, zero
,
775 (ia
->ia_size
- 1), 1);
776 } else { /* ia->ia_size < i_size_read(inode) */
777 /* We're chopping off all the pages down to the page
778 * in which ia->ia_size is located. Fill in the end of
779 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
780 * PAGE_CACHE_SIZE with zeros. */
781 size_t num_zeros
= (PAGE_CACHE_SIZE
782 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
784 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
785 truncate_setsize(inode
, ia
->ia_size
);
786 lower_ia
->ia_size
= ia
->ia_size
;
787 lower_ia
->ia_valid
|= ATTR_SIZE
;
793 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
798 rc
= ecryptfs_write(inode
, zeros_virt
,
799 ia
->ia_size
, num_zeros
);
802 printk(KERN_ERR
"Error attempting to zero out "
803 "the remainder of the end page on "
804 "reducing truncate; rc = [%d]\n", rc
);
808 truncate_setsize(inode
, ia
->ia_size
);
809 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
811 printk(KERN_ERR
"Problem with "
812 "ecryptfs_write_inode_size_to_metadata; "
816 /* We are reducing the size of the ecryptfs file, and need to
817 * know if we need to reduce the size of the lower file. */
818 lower_size_before_truncate
=
819 upper_size_to_lower_size(crypt_stat
, i_size
);
820 lower_size_after_truncate
=
821 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
822 if (lower_size_after_truncate
< lower_size_before_truncate
) {
823 lower_ia
->ia_size
= lower_size_after_truncate
;
824 lower_ia
->ia_valid
|= ATTR_SIZE
;
826 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
829 ecryptfs_put_lower_file(inode
);
833 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
835 struct ecryptfs_crypt_stat
*crypt_stat
;
836 loff_t lower_oldsize
, lower_newsize
;
838 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
839 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
841 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
842 if (lower_newsize
> lower_oldsize
) {
844 * The eCryptfs inode and the new *lower* size are mixed here
845 * because we may not have the lower i_mutex held and/or it may
846 * not be appropriate to call inode_newsize_ok() with inodes
847 * from other filesystems.
849 return inode_newsize_ok(inode
, lower_newsize
);
857 * @dentry: The ecryptfs layer dentry
858 * @new_length: The length to expand the file to
860 * Simple function that handles the truncation of an eCryptfs inode and
861 * its corresponding lower inode.
863 * Returns zero on success; non-zero otherwise
865 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
867 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
868 struct iattr lower_ia
= { .ia_valid
= 0 };
871 rc
= ecryptfs_inode_newsize_ok(dentry
->d_inode
, new_length
);
875 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
876 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
877 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
879 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
880 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
881 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
887 ecryptfs_permission(struct inode
*inode
, int mask
)
889 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
894 * @dentry: dentry handle to the inode to modify
895 * @ia: Structure with flags of what to change and values
897 * Updates the metadata of an inode. If the update is to the size
898 * i.e. truncation, then ecryptfs_truncate will handle the size modification
899 * of both the ecryptfs inode and the lower inode.
901 * All other metadata changes will be passed right to the lower filesystem,
902 * and we will just update our inode to look like the lower.
904 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
907 struct dentry
*lower_dentry
;
908 struct iattr lower_ia
;
910 struct inode
*lower_inode
;
911 struct ecryptfs_crypt_stat
*crypt_stat
;
913 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
914 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
915 ecryptfs_init_crypt_stat(crypt_stat
);
916 inode
= dentry
->d_inode
;
917 lower_inode
= ecryptfs_inode_to_lower(inode
);
918 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
919 mutex_lock(&crypt_stat
->cs_mutex
);
920 if (S_ISDIR(dentry
->d_inode
->i_mode
))
921 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
922 else if (S_ISREG(dentry
->d_inode
->i_mode
)
923 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
924 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
925 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
927 mount_crypt_stat
= &ecryptfs_superblock_to_private(
928 dentry
->d_sb
)->mount_crypt_stat
;
929 rc
= ecryptfs_get_lower_file(dentry
, inode
);
931 mutex_unlock(&crypt_stat
->cs_mutex
);
934 rc
= ecryptfs_read_metadata(dentry
);
935 ecryptfs_put_lower_file(inode
);
937 if (!(mount_crypt_stat
->flags
938 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
940 printk(KERN_WARNING
"Either the lower file "
941 "is not in a valid eCryptfs format, "
942 "or the key could not be retrieved. "
943 "Plaintext passthrough mode is not "
944 "enabled; returning -EIO\n");
945 mutex_unlock(&crypt_stat
->cs_mutex
);
949 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
950 | ECRYPTFS_ENCRYPTED
);
953 mutex_unlock(&crypt_stat
->cs_mutex
);
955 rc
= inode_change_ok(inode
, ia
);
958 if (ia
->ia_valid
& ATTR_SIZE
) {
959 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
964 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
965 if (ia
->ia_valid
& ATTR_FILE
)
966 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
967 if (ia
->ia_valid
& ATTR_SIZE
) {
968 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
974 * mode change is for clearing setuid/setgid bits. Allow lower fs
975 * to interpret this in its own way.
977 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
978 lower_ia
.ia_valid
&= ~ATTR_MODE
;
980 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
981 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
982 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
984 fsstack_copy_attr_all(inode
, lower_inode
);
988 static int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
991 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
994 mount_crypt_stat
= &ecryptfs_superblock_to_private(
995 dentry
->d_sb
)->mount_crypt_stat
;
996 generic_fillattr(dentry
->d_inode
, stat
);
997 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1001 target
= ecryptfs_readlink_lower(dentry
, &targetsiz
);
1002 if (!IS_ERR(target
)) {
1004 stat
->size
= targetsiz
;
1006 rc
= PTR_ERR(target
);
1012 static int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1015 struct kstat lower_stat
;
1018 rc
= vfs_getattr(ecryptfs_dentry_to_lower_path(dentry
), &lower_stat
);
1020 fsstack_copy_attr_all(dentry
->d_inode
,
1021 ecryptfs_inode_to_lower(dentry
->d_inode
));
1022 generic_fillattr(dentry
->d_inode
, stat
);
1023 stat
->blocks
= lower_stat
.blocks
;
1029 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1030 size_t size
, int flags
)
1033 struct dentry
*lower_dentry
;
1035 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1036 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1041 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1043 fsstack_copy_attr_all(dentry
->d_inode
, lower_dentry
->d_inode
);
1049 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1050 void *value
, size_t size
)
1054 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1058 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1059 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1061 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1067 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1070 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1075 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1078 struct dentry
*lower_dentry
;
1080 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1081 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1085 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1086 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1087 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1092 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1095 struct dentry
*lower_dentry
;
1097 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1098 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1102 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1103 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1104 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1109 const struct inode_operations ecryptfs_symlink_iops
= {
1110 .readlink
= generic_readlink
,
1111 .follow_link
= ecryptfs_follow_link
,
1112 .put_link
= kfree_put_link
,
1113 .permission
= ecryptfs_permission
,
1114 .setattr
= ecryptfs_setattr
,
1115 .getattr
= ecryptfs_getattr_link
,
1116 .setxattr
= ecryptfs_setxattr
,
1117 .getxattr
= ecryptfs_getxattr
,
1118 .listxattr
= ecryptfs_listxattr
,
1119 .removexattr
= ecryptfs_removexattr
1122 const struct inode_operations ecryptfs_dir_iops
= {
1123 .create
= ecryptfs_create
,
1124 .lookup
= ecryptfs_lookup
,
1125 .link
= ecryptfs_link
,
1126 .unlink
= ecryptfs_unlink
,
1127 .symlink
= ecryptfs_symlink
,
1128 .mkdir
= ecryptfs_mkdir
,
1129 .rmdir
= ecryptfs_rmdir
,
1130 .mknod
= ecryptfs_mknod
,
1131 .rename
= ecryptfs_rename
,
1132 .permission
= ecryptfs_permission
,
1133 .setattr
= ecryptfs_setattr
,
1134 .setxattr
= ecryptfs_setxattr
,
1135 .getxattr
= ecryptfs_getxattr
,
1136 .listxattr
= ecryptfs_listxattr
,
1137 .removexattr
= ecryptfs_removexattr
1140 const struct inode_operations ecryptfs_main_iops
= {
1141 .permission
= ecryptfs_permission
,
1142 .setattr
= ecryptfs_setattr
,
1143 .getattr
= ecryptfs_getattr
,
1144 .setxattr
= ecryptfs_setxattr
,
1145 .getxattr
= ecryptfs_getxattr
,
1146 .listxattr
= ecryptfs_listxattr
,
1147 .removexattr
= ecryptfs_removexattr