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 inode_lock_nested(d_inode(dir
), I_MUTEX_PARENT
);
48 static void unlock_dir(struct dentry
*dir
)
50 inode_unlock(d_inode(dir
));
54 static int ecryptfs_inode_test(struct inode
*inode
, void *lower_inode
)
56 return ecryptfs_inode_to_lower(inode
) == lower_inode
;
59 static int ecryptfs_inode_set(struct inode
*inode
, void *opaque
)
61 struct inode
*lower_inode
= opaque
;
63 ecryptfs_set_inode_lower(inode
, lower_inode
);
64 fsstack_copy_attr_all(inode
, lower_inode
);
65 /* i_size will be overwritten for encrypted regular files */
66 fsstack_copy_inode_size(inode
, lower_inode
);
67 inode
->i_ino
= lower_inode
->i_ino
;
69 inode
->i_mapping
->a_ops
= &ecryptfs_aops
;
71 if (S_ISLNK(inode
->i_mode
))
72 inode
->i_op
= &ecryptfs_symlink_iops
;
73 else if (S_ISDIR(inode
->i_mode
))
74 inode
->i_op
= &ecryptfs_dir_iops
;
76 inode
->i_op
= &ecryptfs_main_iops
;
78 if (S_ISDIR(inode
->i_mode
))
79 inode
->i_fop
= &ecryptfs_dir_fops
;
80 else if (special_file(inode
->i_mode
))
81 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
83 inode
->i_fop
= &ecryptfs_main_fops
;
88 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
89 struct super_block
*sb
)
93 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
94 return ERR_PTR(-EXDEV
);
95 if (!igrab(lower_inode
))
96 return ERR_PTR(-ESTALE
);
97 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
98 ecryptfs_inode_test
, ecryptfs_inode_set
,
102 return ERR_PTR(-EACCES
);
104 if (!(inode
->i_state
& I_NEW
))
110 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
111 struct super_block
*sb
)
113 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
115 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
116 unlock_new_inode(inode
);
123 * @lower_dentry: Existing dentry in the lower filesystem
124 * @dentry: ecryptfs' dentry
125 * @sb: ecryptfs's super_block
127 * Interposes upper and lower dentries.
129 * Returns zero on success; non-zero otherwise
131 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
132 struct dentry
*dentry
, struct super_block
*sb
)
134 struct inode
*inode
= ecryptfs_get_inode(d_inode(lower_dentry
), sb
);
137 return PTR_ERR(inode
);
138 d_instantiate(dentry
, inode
);
143 static int ecryptfs_do_unlink(struct inode
*dir
, struct dentry
*dentry
,
146 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
147 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
148 struct dentry
*lower_dir_dentry
;
152 lower_dir_dentry
= lock_parent(lower_dentry
);
153 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
, NULL
);
155 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
158 fsstack_copy_attr_times(dir
, lower_dir_inode
);
159 set_nlink(inode
, ecryptfs_inode_to_lower(inode
)->i_nlink
);
160 inode
->i_ctime
= dir
->i_ctime
;
163 unlock_dir(lower_dir_dentry
);
170 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
171 * @ecryptfs_dentry: New file's dentry in ecryptfs
172 * @mode: The mode of the new file
174 * Creates the underlying file and the eCryptfs inode which will link to
175 * it. It will also update the eCryptfs directory inode to mimic the
176 * stat of the lower directory inode.
178 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
180 static struct inode
*
181 ecryptfs_do_create(struct inode
*directory_inode
,
182 struct dentry
*ecryptfs_dentry
, umode_t mode
)
185 struct dentry
*lower_dentry
;
186 struct dentry
*lower_dir_dentry
;
189 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
190 lower_dir_dentry
= lock_parent(lower_dentry
);
191 rc
= vfs_create(d_inode(lower_dir_dentry
), lower_dentry
, mode
, true);
193 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
194 "rc = [%d]\n", __func__
, rc
);
198 inode
= __ecryptfs_get_inode(d_inode(lower_dentry
),
199 directory_inode
->i_sb
);
201 vfs_unlink(d_inode(lower_dir_dentry
), lower_dentry
, NULL
);
204 fsstack_copy_attr_times(directory_inode
, d_inode(lower_dir_dentry
));
205 fsstack_copy_inode_size(directory_inode
, d_inode(lower_dir_dentry
));
207 unlock_dir(lower_dir_dentry
);
212 * ecryptfs_initialize_file
214 * Cause the file to be changed from a basic empty file to an ecryptfs
215 * file with a header and first data page.
217 * Returns zero on success
219 int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
220 struct inode
*ecryptfs_inode
)
222 struct ecryptfs_crypt_stat
*crypt_stat
=
223 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
226 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
227 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
228 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
231 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
232 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
234 ecryptfs_printk(KERN_ERR
, "Error creating new file "
235 "context; rc = [%d]\n", rc
);
238 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
240 printk(KERN_ERR
"%s: Error attempting to initialize "
241 "the lower file for the dentry with name "
242 "[%pd]; rc = [%d]\n", __func__
,
243 ecryptfs_dentry
, rc
);
246 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
248 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
249 ecryptfs_put_lower_file(ecryptfs_inode
);
256 * @dir: The inode of the directory in which to create the file.
257 * @dentry: The eCryptfs dentry
258 * @mode: The mode of the new file.
260 * Creates a new file.
262 * Returns zero on success; non-zero on error condition
265 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
266 umode_t mode
, bool excl
)
268 struct inode
*ecryptfs_inode
;
271 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
273 if (IS_ERR(ecryptfs_inode
)) {
274 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
275 "lower filesystem\n");
276 rc
= PTR_ERR(ecryptfs_inode
);
279 /* At this point, a file exists on "disk"; we need to make sure
280 * that this on disk file is prepared to be an ecryptfs file */
281 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
283 ecryptfs_do_unlink(directory_inode
, ecryptfs_dentry
,
285 iget_failed(ecryptfs_inode
);
288 unlock_new_inode(ecryptfs_inode
);
289 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
294 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
296 struct ecryptfs_crypt_stat
*crypt_stat
;
299 rc
= ecryptfs_get_lower_file(dentry
, inode
);
301 printk(KERN_ERR
"%s: Error attempting to initialize "
302 "the lower file for the dentry with name "
303 "[%pd]; rc = [%d]\n", __func__
,
308 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
309 /* TODO: lock for crypt_stat comparison */
310 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
311 ecryptfs_set_default_sizes(crypt_stat
);
313 rc
= ecryptfs_read_and_validate_header_region(inode
);
314 ecryptfs_put_lower_file(inode
);
316 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
318 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
321 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
326 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
328 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
329 struct dentry
*lower_dentry
,
330 struct inode
*dir_inode
)
332 struct inode
*inode
, *lower_inode
= d_inode(lower_dentry
);
333 struct ecryptfs_dentry_info
*dentry_info
;
334 struct vfsmount
*lower_mnt
;
337 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
339 printk(KERN_ERR
"%s: Out of memory whilst attempting "
340 "to allocate ecryptfs_dentry_info struct\n",
346 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
347 fsstack_copy_attr_atime(dir_inode
, d_inode(lower_dentry
->d_parent
));
348 BUG_ON(!d_count(lower_dentry
));
350 ecryptfs_set_dentry_private(dentry
, dentry_info
);
351 dentry_info
->lower_path
.mnt
= lower_mnt
;
352 dentry_info
->lower_path
.dentry
= lower_dentry
;
354 if (d_really_is_negative(lower_dentry
)) {
355 /* We want to add because we couldn't find in lower */
359 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
361 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
362 __func__
, PTR_ERR(inode
));
363 return PTR_ERR(inode
);
365 if (S_ISREG(inode
->i_mode
)) {
366 rc
= ecryptfs_i_size_read(dentry
, inode
);
368 make_bad_inode(inode
);
373 if (inode
->i_state
& I_NEW
)
374 unlock_new_inode(inode
);
375 d_add(dentry
, inode
);
382 * @ecryptfs_dir_inode: The eCryptfs directory inode
383 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
384 * @flags: lookup flags
386 * Find a file on disk. If the file does not exist, then we'll add it to the
387 * dentry cache and continue on to read it from the disk.
389 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
390 struct dentry
*ecryptfs_dentry
,
393 char *encrypted_and_encoded_name
= NULL
;
394 size_t encrypted_and_encoded_name_size
;
395 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
396 struct dentry
*lower_dir_dentry
, *lower_dentry
;
399 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
400 inode_lock(d_inode(lower_dir_dentry
));
401 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
403 ecryptfs_dentry
->d_name
.len
);
404 inode_unlock(d_inode(lower_dir_dentry
));
405 if (IS_ERR(lower_dentry
)) {
406 rc
= PTR_ERR(lower_dentry
);
407 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
408 "[%d] on lower_dentry = [%pd]\n", __func__
, rc
,
412 if (d_really_is_positive(lower_dentry
))
414 mount_crypt_stat
= &ecryptfs_superblock_to_private(
415 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
416 if (!(mount_crypt_stat
417 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
420 rc
= ecryptfs_encrypt_and_encode_filename(
421 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
422 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
423 ecryptfs_dentry
->d_name
.len
);
425 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
426 "filename; rc = [%d]\n", __func__
, rc
);
429 inode_lock(d_inode(lower_dir_dentry
));
430 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
432 encrypted_and_encoded_name_size
);
433 inode_unlock(d_inode(lower_dir_dentry
));
434 if (IS_ERR(lower_dentry
)) {
435 rc
= PTR_ERR(lower_dentry
);
436 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
437 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
438 encrypted_and_encoded_name
);
442 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
445 kfree(encrypted_and_encoded_name
);
449 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
450 struct dentry
*new_dentry
)
452 struct dentry
*lower_old_dentry
;
453 struct dentry
*lower_new_dentry
;
454 struct dentry
*lower_dir_dentry
;
458 file_size_save
= i_size_read(d_inode(old_dentry
));
459 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
460 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
461 dget(lower_old_dentry
);
462 dget(lower_new_dentry
);
463 lower_dir_dentry
= lock_parent(lower_new_dentry
);
464 rc
= vfs_link(lower_old_dentry
, d_inode(lower_dir_dentry
),
465 lower_new_dentry
, NULL
);
466 if (rc
|| d_really_is_negative(lower_new_dentry
))
468 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
471 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
472 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
473 set_nlink(d_inode(old_dentry
),
474 ecryptfs_inode_to_lower(d_inode(old_dentry
))->i_nlink
);
475 i_size_write(d_inode(new_dentry
), file_size_save
);
477 unlock_dir(lower_dir_dentry
);
478 dput(lower_new_dentry
);
479 dput(lower_old_dentry
);
483 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
485 return ecryptfs_do_unlink(dir
, dentry
, d_inode(dentry
));
488 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
492 struct dentry
*lower_dentry
;
493 struct dentry
*lower_dir_dentry
;
494 char *encoded_symname
;
495 size_t encoded_symlen
;
496 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
498 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
500 lower_dir_dentry
= lock_parent(lower_dentry
);
501 mount_crypt_stat
= &ecryptfs_superblock_to_private(
502 dir
->i_sb
)->mount_crypt_stat
;
503 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
506 mount_crypt_stat
, symname
,
510 rc
= vfs_symlink(d_inode(lower_dir_dentry
), lower_dentry
,
512 kfree(encoded_symname
);
513 if (rc
|| d_really_is_negative(lower_dentry
))
515 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
518 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
519 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
521 unlock_dir(lower_dir_dentry
);
523 if (d_really_is_negative(dentry
))
528 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
531 struct dentry
*lower_dentry
;
532 struct dentry
*lower_dir_dentry
;
534 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
535 lower_dir_dentry
= lock_parent(lower_dentry
);
536 rc
= vfs_mkdir(d_inode(lower_dir_dentry
), lower_dentry
, mode
);
537 if (rc
|| d_really_is_negative(lower_dentry
))
539 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
542 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
543 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
544 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
546 unlock_dir(lower_dir_dentry
);
547 if (d_really_is_negative(dentry
))
552 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
554 struct dentry
*lower_dentry
;
555 struct dentry
*lower_dir_dentry
;
558 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
560 lower_dir_dentry
= lock_parent(lower_dentry
);
562 rc
= vfs_rmdir(d_inode(lower_dir_dentry
), lower_dentry
);
564 if (!rc
&& d_really_is_positive(dentry
))
565 clear_nlink(d_inode(dentry
));
566 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
567 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
568 unlock_dir(lower_dir_dentry
);
576 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
579 struct dentry
*lower_dentry
;
580 struct dentry
*lower_dir_dentry
;
582 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
583 lower_dir_dentry
= lock_parent(lower_dentry
);
584 rc
= vfs_mknod(d_inode(lower_dir_dentry
), lower_dentry
, mode
, dev
);
585 if (rc
|| d_really_is_negative(lower_dentry
))
587 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
590 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
591 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
593 unlock_dir(lower_dir_dentry
);
594 if (d_really_is_negative(dentry
))
600 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
601 struct inode
*new_dir
, struct dentry
*new_dentry
)
604 struct dentry
*lower_old_dentry
;
605 struct dentry
*lower_new_dentry
;
606 struct dentry
*lower_old_dir_dentry
;
607 struct dentry
*lower_new_dir_dentry
;
608 struct dentry
*trap
= NULL
;
609 struct inode
*target_inode
;
611 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
612 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
613 dget(lower_old_dentry
);
614 dget(lower_new_dentry
);
615 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
616 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
617 target_inode
= d_inode(new_dentry
);
618 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
619 /* source should not be ancestor of target */
620 if (trap
== lower_old_dentry
) {
624 /* target should not be ancestor of source */
625 if (trap
== lower_new_dentry
) {
629 rc
= vfs_rename(d_inode(lower_old_dir_dentry
), lower_old_dentry
,
630 d_inode(lower_new_dir_dentry
), lower_new_dentry
,
635 fsstack_copy_attr_all(target_inode
,
636 ecryptfs_inode_to_lower(target_inode
));
637 fsstack_copy_attr_all(new_dir
, d_inode(lower_new_dir_dentry
));
638 if (new_dir
!= old_dir
)
639 fsstack_copy_attr_all(old_dir
, d_inode(lower_old_dir_dentry
));
641 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
642 dput(lower_new_dir_dentry
);
643 dput(lower_old_dir_dentry
);
644 dput(lower_new_dentry
);
645 dput(lower_old_dentry
);
649 static char *ecryptfs_readlink_lower(struct dentry
*dentry
, size_t *bufsiz
)
651 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
657 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
659 return ERR_PTR(-ENOMEM
);
662 rc
= d_inode(lower_dentry
)->i_op
->readlink(lower_dentry
,
663 (char __user
*)lower_buf
,
668 rc
= ecryptfs_decode_and_decrypt_filename(&buf
, bufsiz
, dentry
->d_sb
,
672 return rc
? ERR_PTR(rc
) : buf
;
675 static const char *ecryptfs_get_link(struct dentry
*dentry
,
677 struct delayed_call
*done
)
683 return ERR_PTR(-ECHILD
);
685 buf
= ecryptfs_readlink_lower(dentry
, &len
);
688 fsstack_copy_attr_atime(d_inode(dentry
),
689 d_inode(ecryptfs_dentry_to_lower(dentry
)));
691 set_delayed_call(done
, kfree_link
, buf
);
696 * upper_size_to_lower_size
697 * @crypt_stat: Crypt_stat associated with file
698 * @upper_size: Size of the upper file
700 * Calculate the required size of the lower file based on the
701 * specified size of the upper file. This calculation is based on the
702 * number of headers in the underlying file and the extent size.
704 * Returns Calculated size of the lower file.
707 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
712 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
713 if (upper_size
!= 0) {
716 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
717 if (upper_size
& ~crypt_stat
->extent_mask
)
719 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
726 * @dentry: The ecryptfs layer dentry
727 * @ia: Address of the ecryptfs inode's attributes
728 * @lower_ia: Address of the lower inode's attributes
730 * Function to handle truncations modifying the size of the file. Note
731 * that the file sizes are interpolated. When expanding, we are simply
732 * writing strings of 0's out. When truncating, we truncate the upper
733 * inode and update the lower_ia according to the page index
734 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
735 * the caller must use lower_ia in a call to notify_change() to perform
736 * the truncation of the lower inode.
738 * Returns zero on success; non-zero otherwise
740 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
741 struct iattr
*lower_ia
)
744 struct inode
*inode
= d_inode(dentry
);
745 struct ecryptfs_crypt_stat
*crypt_stat
;
746 loff_t i_size
= i_size_read(inode
);
747 loff_t lower_size_before_truncate
;
748 loff_t lower_size_after_truncate
;
750 if (unlikely((ia
->ia_size
== i_size
))) {
751 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
754 rc
= ecryptfs_get_lower_file(dentry
, inode
);
757 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
758 /* Switch on growing or shrinking file */
759 if (ia
->ia_size
> i_size
) {
760 char zero
[] = { 0x00 };
762 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
763 /* Write a single 0 at the last position of the file;
764 * this triggers code that will fill in 0's throughout
765 * the intermediate portion of the previous end of the
766 * file and the new and of the file */
767 rc
= ecryptfs_write(inode
, zero
,
768 (ia
->ia_size
- 1), 1);
769 } else { /* ia->ia_size < i_size_read(inode) */
770 /* We're chopping off all the pages down to the page
771 * in which ia->ia_size is located. Fill in the end of
772 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
773 * PAGE_CACHE_SIZE with zeros. */
774 size_t num_zeros
= (PAGE_CACHE_SIZE
775 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
777 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
778 truncate_setsize(inode
, ia
->ia_size
);
779 lower_ia
->ia_size
= ia
->ia_size
;
780 lower_ia
->ia_valid
|= ATTR_SIZE
;
786 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
791 rc
= ecryptfs_write(inode
, zeros_virt
,
792 ia
->ia_size
, num_zeros
);
795 printk(KERN_ERR
"Error attempting to zero out "
796 "the remainder of the end page on "
797 "reducing truncate; rc = [%d]\n", rc
);
801 truncate_setsize(inode
, ia
->ia_size
);
802 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
804 printk(KERN_ERR
"Problem with "
805 "ecryptfs_write_inode_size_to_metadata; "
809 /* We are reducing the size of the ecryptfs file, and need to
810 * know if we need to reduce the size of the lower file. */
811 lower_size_before_truncate
=
812 upper_size_to_lower_size(crypt_stat
, i_size
);
813 lower_size_after_truncate
=
814 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
815 if (lower_size_after_truncate
< lower_size_before_truncate
) {
816 lower_ia
->ia_size
= lower_size_after_truncate
;
817 lower_ia
->ia_valid
|= ATTR_SIZE
;
819 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
822 ecryptfs_put_lower_file(inode
);
826 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
828 struct ecryptfs_crypt_stat
*crypt_stat
;
829 loff_t lower_oldsize
, lower_newsize
;
831 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
832 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
834 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
835 if (lower_newsize
> lower_oldsize
) {
837 * The eCryptfs inode and the new *lower* size are mixed here
838 * because we may not have the lower i_mutex held and/or it may
839 * not be appropriate to call inode_newsize_ok() with inodes
840 * from other filesystems.
842 return inode_newsize_ok(inode
, lower_newsize
);
850 * @dentry: The ecryptfs layer dentry
851 * @new_length: The length to expand the file to
853 * Simple function that handles the truncation of an eCryptfs inode and
854 * its corresponding lower inode.
856 * Returns zero on success; non-zero otherwise
858 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
860 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
861 struct iattr lower_ia
= { .ia_valid
= 0 };
864 rc
= ecryptfs_inode_newsize_ok(d_inode(dentry
), new_length
);
868 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
869 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
870 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
872 inode_lock(d_inode(lower_dentry
));
873 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
874 inode_unlock(d_inode(lower_dentry
));
880 ecryptfs_permission(struct inode
*inode
, int mask
)
882 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
887 * @dentry: dentry handle to the inode to modify
888 * @ia: Structure with flags of what to change and values
890 * Updates the metadata of an inode. If the update is to the size
891 * i.e. truncation, then ecryptfs_truncate will handle the size modification
892 * of both the ecryptfs inode and the lower inode.
894 * All other metadata changes will be passed right to the lower filesystem,
895 * and we will just update our inode to look like the lower.
897 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
900 struct dentry
*lower_dentry
;
901 struct iattr lower_ia
;
903 struct inode
*lower_inode
;
904 struct ecryptfs_crypt_stat
*crypt_stat
;
906 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
907 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
908 ecryptfs_init_crypt_stat(crypt_stat
);
909 inode
= d_inode(dentry
);
910 lower_inode
= ecryptfs_inode_to_lower(inode
);
911 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
912 mutex_lock(&crypt_stat
->cs_mutex
);
913 if (d_is_dir(dentry
))
914 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
915 else if (d_is_reg(dentry
)
916 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
917 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
918 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
920 mount_crypt_stat
= &ecryptfs_superblock_to_private(
921 dentry
->d_sb
)->mount_crypt_stat
;
922 rc
= ecryptfs_get_lower_file(dentry
, inode
);
924 mutex_unlock(&crypt_stat
->cs_mutex
);
927 rc
= ecryptfs_read_metadata(dentry
);
928 ecryptfs_put_lower_file(inode
);
930 if (!(mount_crypt_stat
->flags
931 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
933 printk(KERN_WARNING
"Either the lower file "
934 "is not in a valid eCryptfs format, "
935 "or the key could not be retrieved. "
936 "Plaintext passthrough mode is not "
937 "enabled; returning -EIO\n");
938 mutex_unlock(&crypt_stat
->cs_mutex
);
942 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
943 | ECRYPTFS_ENCRYPTED
);
946 mutex_unlock(&crypt_stat
->cs_mutex
);
948 rc
= inode_change_ok(inode
, ia
);
951 if (ia
->ia_valid
& ATTR_SIZE
) {
952 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
957 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
958 if (ia
->ia_valid
& ATTR_FILE
)
959 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
960 if (ia
->ia_valid
& ATTR_SIZE
) {
961 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
967 * mode change is for clearing setuid/setgid bits. Allow lower fs
968 * to interpret this in its own way.
970 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
971 lower_ia
.ia_valid
&= ~ATTR_MODE
;
973 inode_lock(d_inode(lower_dentry
));
974 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
975 inode_unlock(d_inode(lower_dentry
));
977 fsstack_copy_attr_all(inode
, lower_inode
);
981 static int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
984 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
987 mount_crypt_stat
= &ecryptfs_superblock_to_private(
988 dentry
->d_sb
)->mount_crypt_stat
;
989 generic_fillattr(d_inode(dentry
), stat
);
990 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
994 target
= ecryptfs_readlink_lower(dentry
, &targetsiz
);
995 if (!IS_ERR(target
)) {
997 stat
->size
= targetsiz
;
999 rc
= PTR_ERR(target
);
1005 static int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1008 struct kstat lower_stat
;
1011 rc
= vfs_getattr(ecryptfs_dentry_to_lower_path(dentry
), &lower_stat
);
1013 fsstack_copy_attr_all(d_inode(dentry
),
1014 ecryptfs_inode_to_lower(d_inode(dentry
)));
1015 generic_fillattr(d_inode(dentry
), stat
);
1016 stat
->blocks
= lower_stat
.blocks
;
1022 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1023 size_t size
, int flags
)
1026 struct dentry
*lower_dentry
;
1028 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1029 if (!d_inode(lower_dentry
)->i_op
->setxattr
) {
1034 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1035 if (!rc
&& d_really_is_positive(dentry
))
1036 fsstack_copy_attr_all(d_inode(dentry
), d_inode(lower_dentry
));
1042 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1043 void *value
, size_t size
)
1047 if (!d_inode(lower_dentry
)->i_op
->getxattr
) {
1051 inode_lock(d_inode(lower_dentry
));
1052 rc
= d_inode(lower_dentry
)->i_op
->getxattr(lower_dentry
, name
, value
,
1054 inode_unlock(d_inode(lower_dentry
));
1060 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1063 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1068 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1071 struct dentry
*lower_dentry
;
1073 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1074 if (!d_inode(lower_dentry
)->i_op
->listxattr
) {
1078 inode_lock(d_inode(lower_dentry
));
1079 rc
= d_inode(lower_dentry
)->i_op
->listxattr(lower_dentry
, list
, size
);
1080 inode_unlock(d_inode(lower_dentry
));
1085 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1088 struct dentry
*lower_dentry
;
1090 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1091 if (!d_inode(lower_dentry
)->i_op
->removexattr
) {
1095 inode_lock(d_inode(lower_dentry
));
1096 rc
= d_inode(lower_dentry
)->i_op
->removexattr(lower_dentry
, name
);
1097 inode_unlock(d_inode(lower_dentry
));
1102 const struct inode_operations ecryptfs_symlink_iops
= {
1103 .readlink
= generic_readlink
,
1104 .get_link
= ecryptfs_get_link
,
1105 .permission
= ecryptfs_permission
,
1106 .setattr
= ecryptfs_setattr
,
1107 .getattr
= ecryptfs_getattr_link
,
1108 .setxattr
= ecryptfs_setxattr
,
1109 .getxattr
= ecryptfs_getxattr
,
1110 .listxattr
= ecryptfs_listxattr
,
1111 .removexattr
= ecryptfs_removexattr
1114 const struct inode_operations ecryptfs_dir_iops
= {
1115 .create
= ecryptfs_create
,
1116 .lookup
= ecryptfs_lookup
,
1117 .link
= ecryptfs_link
,
1118 .unlink
= ecryptfs_unlink
,
1119 .symlink
= ecryptfs_symlink
,
1120 .mkdir
= ecryptfs_mkdir
,
1121 .rmdir
= ecryptfs_rmdir
,
1122 .mknod
= ecryptfs_mknod
,
1123 .rename
= ecryptfs_rename
,
1124 .permission
= ecryptfs_permission
,
1125 .setattr
= ecryptfs_setattr
,
1126 .setxattr
= ecryptfs_setxattr
,
1127 .getxattr
= ecryptfs_getxattr
,
1128 .listxattr
= ecryptfs_listxattr
,
1129 .removexattr
= ecryptfs_removexattr
1132 const struct inode_operations ecryptfs_main_iops
= {
1133 .permission
= ecryptfs_permission
,
1134 .setattr
= ecryptfs_setattr
,
1135 .getattr
= ecryptfs_getattr
,
1136 .setxattr
= ecryptfs_setxattr
,
1137 .getxattr
= ecryptfs_getxattr
,
1138 .listxattr
= ecryptfs_listxattr
,
1139 .removexattr
= ecryptfs_removexattr