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/fs_stack.h>
33 #include <linux/slab.h>
34 #include <linux/xattr.h>
35 #include <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry
*lock_parent(struct dentry
*dentry
)
42 dir
= dget_parent(dentry
);
43 inode_lock_nested(d_inode(dir
), I_MUTEX_PARENT
);
47 static void unlock_dir(struct dentry
*dir
)
49 inode_unlock(d_inode(dir
));
53 static int ecryptfs_inode_test(struct inode
*inode
, void *lower_inode
)
55 return ecryptfs_inode_to_lower(inode
) == lower_inode
;
58 static int ecryptfs_inode_set(struct inode
*inode
, void *opaque
)
60 struct inode
*lower_inode
= opaque
;
62 ecryptfs_set_inode_lower(inode
, lower_inode
);
63 fsstack_copy_attr_all(inode
, lower_inode
);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode
, lower_inode
);
66 inode
->i_ino
= lower_inode
->i_ino
;
68 inode
->i_mapping
->a_ops
= &ecryptfs_aops
;
70 if (S_ISLNK(inode
->i_mode
))
71 inode
->i_op
= &ecryptfs_symlink_iops
;
72 else if (S_ISDIR(inode
->i_mode
))
73 inode
->i_op
= &ecryptfs_dir_iops
;
75 inode
->i_op
= &ecryptfs_main_iops
;
77 if (S_ISDIR(inode
->i_mode
))
78 inode
->i_fop
= &ecryptfs_dir_fops
;
79 else if (special_file(inode
->i_mode
))
80 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
82 inode
->i_fop
= &ecryptfs_main_fops
;
87 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
88 struct super_block
*sb
)
92 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
93 return ERR_PTR(-EXDEV
);
94 if (!igrab(lower_inode
))
95 return ERR_PTR(-ESTALE
);
96 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
97 ecryptfs_inode_test
, ecryptfs_inode_set
,
101 return ERR_PTR(-EACCES
);
103 if (!(inode
->i_state
& I_NEW
))
109 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
110 struct super_block
*sb
)
112 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
114 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
115 unlock_new_inode(inode
);
122 * @lower_dentry: Existing dentry in the lower filesystem
123 * @dentry: ecryptfs' dentry
124 * @sb: ecryptfs's super_block
126 * Interposes upper and lower dentries.
128 * Returns zero on success; non-zero otherwise
130 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
131 struct dentry
*dentry
, struct super_block
*sb
)
133 struct inode
*inode
= ecryptfs_get_inode(d_inode(lower_dentry
), sb
);
136 return PTR_ERR(inode
);
137 d_instantiate(dentry
, inode
);
142 static int ecryptfs_do_unlink(struct inode
*dir
, struct dentry
*dentry
,
145 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
146 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
147 struct dentry
*lower_dir_dentry
;
151 lower_dir_dentry
= lock_parent(lower_dentry
);
152 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
, NULL
);
154 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
157 fsstack_copy_attr_times(dir
, lower_dir_inode
);
158 set_nlink(inode
, ecryptfs_inode_to_lower(inode
)->i_nlink
);
159 inode
->i_ctime
= dir
->i_ctime
;
162 unlock_dir(lower_dir_dentry
);
169 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
170 * @ecryptfs_dentry: New file's dentry in ecryptfs
171 * @mode: The mode of the new file
173 * Creates the underlying file and the eCryptfs inode which will link to
174 * it. It will also update the eCryptfs directory inode to mimic the
175 * stat of the lower directory inode.
177 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
179 static struct inode
*
180 ecryptfs_do_create(struct inode
*directory_inode
,
181 struct dentry
*ecryptfs_dentry
, umode_t mode
)
184 struct dentry
*lower_dentry
;
185 struct dentry
*lower_dir_dentry
;
188 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
189 lower_dir_dentry
= lock_parent(lower_dentry
);
190 rc
= vfs_create(d_inode(lower_dir_dentry
), lower_dentry
, mode
, true);
192 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
193 "rc = [%d]\n", __func__
, rc
);
197 inode
= __ecryptfs_get_inode(d_inode(lower_dentry
),
198 directory_inode
->i_sb
);
200 vfs_unlink(d_inode(lower_dir_dentry
), lower_dentry
, NULL
);
203 fsstack_copy_attr_times(directory_inode
, d_inode(lower_dir_dentry
));
204 fsstack_copy_inode_size(directory_inode
, d_inode(lower_dir_dentry
));
206 unlock_dir(lower_dir_dentry
);
211 * ecryptfs_initialize_file
213 * Cause the file to be changed from a basic empty file to an ecryptfs
214 * file with a header and first data page.
216 * Returns zero on success
218 int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
219 struct inode
*ecryptfs_inode
)
221 struct ecryptfs_crypt_stat
*crypt_stat
=
222 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
225 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
226 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
227 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
230 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
231 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
233 ecryptfs_printk(KERN_ERR
, "Error creating new file "
234 "context; rc = [%d]\n", rc
);
237 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
239 printk(KERN_ERR
"%s: Error attempting to initialize "
240 "the lower file for the dentry with name "
241 "[%pd]; rc = [%d]\n", __func__
,
242 ecryptfs_dentry
, rc
);
245 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
247 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
248 ecryptfs_put_lower_file(ecryptfs_inode
);
255 * @dir: The inode of the directory in which to create the file.
256 * @dentry: The eCryptfs dentry
257 * @mode: The mode of the new file.
259 * Creates a new file.
261 * Returns zero on success; non-zero on error condition
264 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
265 umode_t mode
, bool excl
)
267 struct inode
*ecryptfs_inode
;
270 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
272 if (IS_ERR(ecryptfs_inode
)) {
273 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
274 "lower filesystem\n");
275 rc
= PTR_ERR(ecryptfs_inode
);
278 /* At this point, a file exists on "disk"; we need to make sure
279 * that this on disk file is prepared to be an ecryptfs file */
280 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
282 ecryptfs_do_unlink(directory_inode
, ecryptfs_dentry
,
284 iget_failed(ecryptfs_inode
);
287 unlock_new_inode(ecryptfs_inode
);
288 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
293 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
295 struct ecryptfs_crypt_stat
*crypt_stat
;
298 rc
= ecryptfs_get_lower_file(dentry
, inode
);
300 printk(KERN_ERR
"%s: Error attempting to initialize "
301 "the lower file for the dentry with name "
302 "[%pd]; rc = [%d]\n", __func__
,
307 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
308 /* TODO: lock for crypt_stat comparison */
309 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
310 ecryptfs_set_default_sizes(crypt_stat
);
312 rc
= ecryptfs_read_and_validate_header_region(inode
);
313 ecryptfs_put_lower_file(inode
);
315 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
317 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
320 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
325 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
327 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
328 struct dentry
*lower_dentry
,
329 struct inode
*dir_inode
)
331 struct inode
*inode
, *lower_inode
= d_inode(lower_dentry
);
332 struct ecryptfs_dentry_info
*dentry_info
;
333 struct vfsmount
*lower_mnt
;
336 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
338 printk(KERN_ERR
"%s: Out of memory whilst attempting "
339 "to allocate ecryptfs_dentry_info struct\n",
345 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
346 fsstack_copy_attr_atime(dir_inode
, d_inode(lower_dentry
->d_parent
));
347 BUG_ON(!d_count(lower_dentry
));
349 ecryptfs_set_dentry_private(dentry
, dentry_info
);
350 dentry_info
->lower_path
.mnt
= lower_mnt
;
351 dentry_info
->lower_path
.dentry
= lower_dentry
;
353 if (d_really_is_negative(lower_dentry
)) {
354 /* We want to add because we couldn't find in lower */
358 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
360 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
361 __func__
, PTR_ERR(inode
));
362 return PTR_ERR(inode
);
364 if (S_ISREG(inode
->i_mode
)) {
365 rc
= ecryptfs_i_size_read(dentry
, inode
);
367 make_bad_inode(inode
);
372 if (inode
->i_state
& I_NEW
)
373 unlock_new_inode(inode
);
374 d_add(dentry
, inode
);
381 * @ecryptfs_dir_inode: The eCryptfs directory inode
382 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
383 * @flags: lookup flags
385 * Find a file on disk. If the file does not exist, then we'll add it to the
386 * dentry cache and continue on to read it from the disk.
388 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
389 struct dentry
*ecryptfs_dentry
,
392 char *encrypted_and_encoded_name
= NULL
;
393 size_t encrypted_and_encoded_name_size
;
394 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
395 struct dentry
*lower_dir_dentry
, *lower_dentry
;
398 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
399 inode_lock(d_inode(lower_dir_dentry
));
400 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
402 ecryptfs_dentry
->d_name
.len
);
403 inode_unlock(d_inode(lower_dir_dentry
));
404 if (IS_ERR(lower_dentry
)) {
405 rc
= PTR_ERR(lower_dentry
);
406 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
407 "[%d] on lower_dentry = [%pd]\n", __func__
, rc
,
411 if (d_really_is_positive(lower_dentry
))
413 mount_crypt_stat
= &ecryptfs_superblock_to_private(
414 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
415 if (!(mount_crypt_stat
416 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
419 rc
= ecryptfs_encrypt_and_encode_filename(
420 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
421 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
422 ecryptfs_dentry
->d_name
.len
);
424 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
425 "filename; rc = [%d]\n", __func__
, rc
);
428 inode_lock(d_inode(lower_dir_dentry
));
429 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
431 encrypted_and_encoded_name_size
);
432 inode_unlock(d_inode(lower_dir_dentry
));
433 if (IS_ERR(lower_dentry
)) {
434 rc
= PTR_ERR(lower_dentry
);
435 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
436 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
437 encrypted_and_encoded_name
);
441 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
444 kfree(encrypted_and_encoded_name
);
448 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
449 struct dentry
*new_dentry
)
451 struct dentry
*lower_old_dentry
;
452 struct dentry
*lower_new_dentry
;
453 struct dentry
*lower_dir_dentry
;
457 file_size_save
= i_size_read(d_inode(old_dentry
));
458 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
459 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
460 dget(lower_old_dentry
);
461 dget(lower_new_dentry
);
462 lower_dir_dentry
= lock_parent(lower_new_dentry
);
463 rc
= vfs_link(lower_old_dentry
, d_inode(lower_dir_dentry
),
464 lower_new_dentry
, NULL
);
465 if (rc
|| d_really_is_negative(lower_new_dentry
))
467 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
470 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
471 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
472 set_nlink(d_inode(old_dentry
),
473 ecryptfs_inode_to_lower(d_inode(old_dentry
))->i_nlink
);
474 i_size_write(d_inode(new_dentry
), file_size_save
);
476 unlock_dir(lower_dir_dentry
);
477 dput(lower_new_dentry
);
478 dput(lower_old_dentry
);
482 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
484 return ecryptfs_do_unlink(dir
, dentry
, d_inode(dentry
));
487 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
491 struct dentry
*lower_dentry
;
492 struct dentry
*lower_dir_dentry
;
493 char *encoded_symname
;
494 size_t encoded_symlen
;
495 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
497 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
499 lower_dir_dentry
= lock_parent(lower_dentry
);
500 mount_crypt_stat
= &ecryptfs_superblock_to_private(
501 dir
->i_sb
)->mount_crypt_stat
;
502 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
505 mount_crypt_stat
, symname
,
509 rc
= vfs_symlink(d_inode(lower_dir_dentry
), lower_dentry
,
511 kfree(encoded_symname
);
512 if (rc
|| d_really_is_negative(lower_dentry
))
514 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
517 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
518 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
520 unlock_dir(lower_dir_dentry
);
522 if (d_really_is_negative(dentry
))
527 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
530 struct dentry
*lower_dentry
;
531 struct dentry
*lower_dir_dentry
;
533 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
534 lower_dir_dentry
= lock_parent(lower_dentry
);
535 rc
= vfs_mkdir(d_inode(lower_dir_dentry
), lower_dentry
, mode
);
536 if (rc
|| d_really_is_negative(lower_dentry
))
538 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
541 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
542 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
543 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
545 unlock_dir(lower_dir_dentry
);
546 if (d_really_is_negative(dentry
))
551 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
553 struct dentry
*lower_dentry
;
554 struct dentry
*lower_dir_dentry
;
557 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
559 lower_dir_dentry
= lock_parent(lower_dentry
);
561 rc
= vfs_rmdir(d_inode(lower_dir_dentry
), lower_dentry
);
563 if (!rc
&& d_really_is_positive(dentry
))
564 clear_nlink(d_inode(dentry
));
565 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
566 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
567 unlock_dir(lower_dir_dentry
);
575 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
578 struct dentry
*lower_dentry
;
579 struct dentry
*lower_dir_dentry
;
581 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
582 lower_dir_dentry
= lock_parent(lower_dentry
);
583 rc
= vfs_mknod(d_inode(lower_dir_dentry
), lower_dentry
, mode
, dev
);
584 if (rc
|| d_really_is_negative(lower_dentry
))
586 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
589 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
590 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
592 unlock_dir(lower_dir_dentry
);
593 if (d_really_is_negative(dentry
))
599 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
600 struct inode
*new_dir
, struct dentry
*new_dentry
)
603 struct dentry
*lower_old_dentry
;
604 struct dentry
*lower_new_dentry
;
605 struct dentry
*lower_old_dir_dentry
;
606 struct dentry
*lower_new_dir_dentry
;
607 struct dentry
*trap
= NULL
;
608 struct inode
*target_inode
;
610 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
611 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
612 dget(lower_old_dentry
);
613 dget(lower_new_dentry
);
614 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
615 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
616 target_inode
= d_inode(new_dentry
);
617 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
618 /* source should not be ancestor of target */
619 if (trap
== lower_old_dentry
) {
623 /* target should not be ancestor of source */
624 if (trap
== lower_new_dentry
) {
628 rc
= vfs_rename(d_inode(lower_old_dir_dentry
), lower_old_dentry
,
629 d_inode(lower_new_dir_dentry
), lower_new_dentry
,
634 fsstack_copy_attr_all(target_inode
,
635 ecryptfs_inode_to_lower(target_inode
));
636 fsstack_copy_attr_all(new_dir
, d_inode(lower_new_dir_dentry
));
637 if (new_dir
!= old_dir
)
638 fsstack_copy_attr_all(old_dir
, d_inode(lower_old_dir_dentry
));
640 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
641 dput(lower_new_dir_dentry
);
642 dput(lower_old_dir_dentry
);
643 dput(lower_new_dentry
);
644 dput(lower_old_dentry
);
648 static char *ecryptfs_readlink_lower(struct dentry
*dentry
, size_t *bufsiz
)
650 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
656 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
658 return ERR_PTR(-ENOMEM
);
661 rc
= d_inode(lower_dentry
)->i_op
->readlink(lower_dentry
,
662 (char __user
*)lower_buf
,
667 rc
= ecryptfs_decode_and_decrypt_filename(&buf
, bufsiz
, dentry
->d_sb
,
671 return rc
? ERR_PTR(rc
) : buf
;
674 static const char *ecryptfs_get_link(struct dentry
*dentry
,
676 struct delayed_call
*done
)
682 return ERR_PTR(-ECHILD
);
684 buf
= ecryptfs_readlink_lower(dentry
, &len
);
687 fsstack_copy_attr_atime(d_inode(dentry
),
688 d_inode(ecryptfs_dentry_to_lower(dentry
)));
690 set_delayed_call(done
, kfree_link
, buf
);
695 * upper_size_to_lower_size
696 * @crypt_stat: Crypt_stat associated with file
697 * @upper_size: Size of the upper file
699 * Calculate the required size of the lower file based on the
700 * specified size of the upper file. This calculation is based on the
701 * number of headers in the underlying file and the extent size.
703 * Returns Calculated size of the lower file.
706 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
711 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
712 if (upper_size
!= 0) {
715 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
716 if (upper_size
& ~crypt_stat
->extent_mask
)
718 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
725 * @dentry: The ecryptfs layer dentry
726 * @ia: Address of the ecryptfs inode's attributes
727 * @lower_ia: Address of the lower inode's attributes
729 * Function to handle truncations modifying the size of the file. Note
730 * that the file sizes are interpolated. When expanding, we are simply
731 * writing strings of 0's out. When truncating, we truncate the upper
732 * inode and update the lower_ia according to the page index
733 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
734 * the caller must use lower_ia in a call to notify_change() to perform
735 * the truncation of the lower inode.
737 * Returns zero on success; non-zero otherwise
739 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
740 struct iattr
*lower_ia
)
743 struct inode
*inode
= d_inode(dentry
);
744 struct ecryptfs_crypt_stat
*crypt_stat
;
745 loff_t i_size
= i_size_read(inode
);
746 loff_t lower_size_before_truncate
;
747 loff_t lower_size_after_truncate
;
749 if (unlikely((ia
->ia_size
== i_size
))) {
750 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
753 rc
= ecryptfs_get_lower_file(dentry
, inode
);
756 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
757 /* Switch on growing or shrinking file */
758 if (ia
->ia_size
> i_size
) {
759 char zero
[] = { 0x00 };
761 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
762 /* Write a single 0 at the last position of the file;
763 * this triggers code that will fill in 0's throughout
764 * the intermediate portion of the previous end of the
765 * file and the new and of the file */
766 rc
= ecryptfs_write(inode
, zero
,
767 (ia
->ia_size
- 1), 1);
768 } else { /* ia->ia_size < i_size_read(inode) */
769 /* We're chopping off all the pages down to the page
770 * in which ia->ia_size is located. Fill in the end of
771 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
772 * PAGE_CACHE_SIZE with zeros. */
773 size_t num_zeros
= (PAGE_CACHE_SIZE
774 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
776 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
777 truncate_setsize(inode
, ia
->ia_size
);
778 lower_ia
->ia_size
= ia
->ia_size
;
779 lower_ia
->ia_valid
|= ATTR_SIZE
;
785 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
790 rc
= ecryptfs_write(inode
, zeros_virt
,
791 ia
->ia_size
, num_zeros
);
794 printk(KERN_ERR
"Error attempting to zero out "
795 "the remainder of the end page on "
796 "reducing truncate; rc = [%d]\n", rc
);
800 truncate_setsize(inode
, ia
->ia_size
);
801 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
803 printk(KERN_ERR
"Problem with "
804 "ecryptfs_write_inode_size_to_metadata; "
808 /* We are reducing the size of the ecryptfs file, and need to
809 * know if we need to reduce the size of the lower file. */
810 lower_size_before_truncate
=
811 upper_size_to_lower_size(crypt_stat
, i_size
);
812 lower_size_after_truncate
=
813 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
814 if (lower_size_after_truncate
< lower_size_before_truncate
) {
815 lower_ia
->ia_size
= lower_size_after_truncate
;
816 lower_ia
->ia_valid
|= ATTR_SIZE
;
818 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
821 ecryptfs_put_lower_file(inode
);
825 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
827 struct ecryptfs_crypt_stat
*crypt_stat
;
828 loff_t lower_oldsize
, lower_newsize
;
830 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
831 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
833 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
834 if (lower_newsize
> lower_oldsize
) {
836 * The eCryptfs inode and the new *lower* size are mixed here
837 * because we may not have the lower i_mutex held and/or it may
838 * not be appropriate to call inode_newsize_ok() with inodes
839 * from other filesystems.
841 return inode_newsize_ok(inode
, lower_newsize
);
849 * @dentry: The ecryptfs layer dentry
850 * @new_length: The length to expand the file to
852 * Simple function that handles the truncation of an eCryptfs inode and
853 * its corresponding lower inode.
855 * Returns zero on success; non-zero otherwise
857 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
859 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
860 struct iattr lower_ia
= { .ia_valid
= 0 };
863 rc
= ecryptfs_inode_newsize_ok(d_inode(dentry
), new_length
);
867 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
868 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
869 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
871 inode_lock(d_inode(lower_dentry
));
872 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
873 inode_unlock(d_inode(lower_dentry
));
879 ecryptfs_permission(struct inode
*inode
, int mask
)
881 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
886 * @dentry: dentry handle to the inode to modify
887 * @ia: Structure with flags of what to change and values
889 * Updates the metadata of an inode. If the update is to the size
890 * i.e. truncation, then ecryptfs_truncate will handle the size modification
891 * of both the ecryptfs inode and the lower inode.
893 * All other metadata changes will be passed right to the lower filesystem,
894 * and we will just update our inode to look like the lower.
896 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
899 struct dentry
*lower_dentry
;
900 struct iattr lower_ia
;
902 struct inode
*lower_inode
;
903 struct ecryptfs_crypt_stat
*crypt_stat
;
905 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
906 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
907 ecryptfs_init_crypt_stat(crypt_stat
);
908 inode
= d_inode(dentry
);
909 lower_inode
= ecryptfs_inode_to_lower(inode
);
910 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
911 mutex_lock(&crypt_stat
->cs_mutex
);
912 if (d_is_dir(dentry
))
913 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
914 else if (d_is_reg(dentry
)
915 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
916 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
917 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
919 mount_crypt_stat
= &ecryptfs_superblock_to_private(
920 dentry
->d_sb
)->mount_crypt_stat
;
921 rc
= ecryptfs_get_lower_file(dentry
, inode
);
923 mutex_unlock(&crypt_stat
->cs_mutex
);
926 rc
= ecryptfs_read_metadata(dentry
);
927 ecryptfs_put_lower_file(inode
);
929 if (!(mount_crypt_stat
->flags
930 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
932 printk(KERN_WARNING
"Either the lower file "
933 "is not in a valid eCryptfs format, "
934 "or the key could not be retrieved. "
935 "Plaintext passthrough mode is not "
936 "enabled; returning -EIO\n");
937 mutex_unlock(&crypt_stat
->cs_mutex
);
941 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
942 | ECRYPTFS_ENCRYPTED
);
945 mutex_unlock(&crypt_stat
->cs_mutex
);
947 rc
= inode_change_ok(inode
, ia
);
950 if (ia
->ia_valid
& ATTR_SIZE
) {
951 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
956 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
957 if (ia
->ia_valid
& ATTR_FILE
)
958 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
959 if (ia
->ia_valid
& ATTR_SIZE
) {
960 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
966 * mode change is for clearing setuid/setgid bits. Allow lower fs
967 * to interpret this in its own way.
969 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
970 lower_ia
.ia_valid
&= ~ATTR_MODE
;
972 inode_lock(d_inode(lower_dentry
));
973 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
974 inode_unlock(d_inode(lower_dentry
));
976 fsstack_copy_attr_all(inode
, lower_inode
);
980 static int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
983 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
986 mount_crypt_stat
= &ecryptfs_superblock_to_private(
987 dentry
->d_sb
)->mount_crypt_stat
;
988 generic_fillattr(d_inode(dentry
), stat
);
989 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
993 target
= ecryptfs_readlink_lower(dentry
, &targetsiz
);
994 if (!IS_ERR(target
)) {
996 stat
->size
= targetsiz
;
998 rc
= PTR_ERR(target
);
1004 static int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1007 struct kstat lower_stat
;
1010 rc
= vfs_getattr(ecryptfs_dentry_to_lower_path(dentry
), &lower_stat
);
1012 fsstack_copy_attr_all(d_inode(dentry
),
1013 ecryptfs_inode_to_lower(d_inode(dentry
)));
1014 generic_fillattr(d_inode(dentry
), stat
);
1015 stat
->blocks
= lower_stat
.blocks
;
1021 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1022 size_t size
, int flags
)
1025 struct dentry
*lower_dentry
;
1027 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1028 if (!d_inode(lower_dentry
)->i_op
->setxattr
) {
1033 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1034 if (!rc
&& d_really_is_positive(dentry
))
1035 fsstack_copy_attr_all(d_inode(dentry
), d_inode(lower_dentry
));
1041 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1042 void *value
, size_t size
)
1046 if (!d_inode(lower_dentry
)->i_op
->getxattr
) {
1050 inode_lock(d_inode(lower_dentry
));
1051 rc
= d_inode(lower_dentry
)->i_op
->getxattr(lower_dentry
, name
, value
,
1053 inode_unlock(d_inode(lower_dentry
));
1059 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1062 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1067 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1070 struct dentry
*lower_dentry
;
1072 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1073 if (!d_inode(lower_dentry
)->i_op
->listxattr
) {
1077 inode_lock(d_inode(lower_dentry
));
1078 rc
= d_inode(lower_dentry
)->i_op
->listxattr(lower_dentry
, list
, size
);
1079 inode_unlock(d_inode(lower_dentry
));
1084 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1087 struct dentry
*lower_dentry
;
1089 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1090 if (!d_inode(lower_dentry
)->i_op
->removexattr
) {
1094 inode_lock(d_inode(lower_dentry
));
1095 rc
= d_inode(lower_dentry
)->i_op
->removexattr(lower_dentry
, name
);
1096 inode_unlock(d_inode(lower_dentry
));
1101 const struct inode_operations ecryptfs_symlink_iops
= {
1102 .readlink
= generic_readlink
,
1103 .get_link
= ecryptfs_get_link
,
1104 .permission
= ecryptfs_permission
,
1105 .setattr
= ecryptfs_setattr
,
1106 .getattr
= ecryptfs_getattr_link
,
1107 .setxattr
= ecryptfs_setxattr
,
1108 .getxattr
= ecryptfs_getxattr
,
1109 .listxattr
= ecryptfs_listxattr
,
1110 .removexattr
= ecryptfs_removexattr
1113 const struct inode_operations ecryptfs_dir_iops
= {
1114 .create
= ecryptfs_create
,
1115 .lookup
= ecryptfs_lookup
,
1116 .link
= ecryptfs_link
,
1117 .unlink
= ecryptfs_unlink
,
1118 .symlink
= ecryptfs_symlink
,
1119 .mkdir
= ecryptfs_mkdir
,
1120 .rmdir
= ecryptfs_rmdir
,
1121 .mknod
= ecryptfs_mknod
,
1122 .rename
= ecryptfs_rename
,
1123 .permission
= ecryptfs_permission
,
1124 .setattr
= ecryptfs_setattr
,
1125 .setxattr
= ecryptfs_setxattr
,
1126 .getxattr
= ecryptfs_getxattr
,
1127 .listxattr
= ecryptfs_listxattr
,
1128 .removexattr
= ecryptfs_removexattr
1131 const struct inode_operations ecryptfs_main_iops
= {
1132 .permission
= ecryptfs_permission
,
1133 .setattr
= ecryptfs_setattr
,
1134 .getattr
= ecryptfs_getattr
,
1135 .setxattr
= ecryptfs_setxattr
,
1136 .getxattr
= ecryptfs_getxattr
,
1137 .listxattr
= ecryptfs_listxattr
,
1138 .removexattr
= ecryptfs_removexattr