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(&(d_inode(dir
)->i_mutex
), I_MUTEX_PARENT
);
48 static void unlock_dir(struct dentry
*dir
)
50 mutex_unlock(&d_inode(dir
)->i_mutex
);
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
173 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
175 * Creates the underlying file and the eCryptfs inode which will link to
176 * it. It will also update the eCryptfs directory inode to mimic the
177 * stat of the lower directory inode.
179 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
181 static struct inode
*
182 ecryptfs_do_create(struct inode
*directory_inode
,
183 struct dentry
*ecryptfs_dentry
, umode_t mode
)
186 struct dentry
*lower_dentry
;
187 struct dentry
*lower_dir_dentry
;
190 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
191 lower_dir_dentry
= lock_parent(lower_dentry
);
192 rc
= vfs_create(d_inode(lower_dir_dentry
), lower_dentry
, mode
, true);
194 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
195 "rc = [%d]\n", __func__
, rc
);
199 inode
= __ecryptfs_get_inode(d_inode(lower_dentry
),
200 directory_inode
->i_sb
);
202 vfs_unlink(d_inode(lower_dir_dentry
), lower_dentry
, NULL
);
205 fsstack_copy_attr_times(directory_inode
, d_inode(lower_dir_dentry
));
206 fsstack_copy_inode_size(directory_inode
, d_inode(lower_dir_dentry
));
208 unlock_dir(lower_dir_dentry
);
213 * ecryptfs_initialize_file
215 * Cause the file to be changed from a basic empty file to an ecryptfs
216 * file with a header and first data page.
218 * Returns zero on success
220 int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
221 struct inode
*ecryptfs_inode
)
223 struct ecryptfs_crypt_stat
*crypt_stat
=
224 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
227 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
228 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
229 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
232 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
233 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
235 ecryptfs_printk(KERN_ERR
, "Error creating new file "
236 "context; rc = [%d]\n", rc
);
239 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
241 printk(KERN_ERR
"%s: Error attempting to initialize "
242 "the lower file for the dentry with name "
243 "[%pd]; rc = [%d]\n", __func__
,
244 ecryptfs_dentry
, rc
);
247 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
249 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
250 ecryptfs_put_lower_file(ecryptfs_inode
);
257 * @dir: The inode of the directory in which to create the file.
258 * @dentry: The eCryptfs dentry
259 * @mode: The mode of the new file.
261 * Creates a new file.
263 * Returns zero on success; non-zero on error condition
266 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
267 umode_t mode
, bool excl
)
269 struct inode
*ecryptfs_inode
;
272 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
274 if (unlikely(IS_ERR(ecryptfs_inode
))) {
275 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
276 "lower filesystem\n");
277 rc
= PTR_ERR(ecryptfs_inode
);
280 /* At this point, a file exists on "disk"; we need to make sure
281 * that this on disk file is prepared to be an ecryptfs file */
282 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
284 ecryptfs_do_unlink(directory_inode
, ecryptfs_dentry
,
286 make_bad_inode(ecryptfs_inode
);
287 unlock_new_inode(ecryptfs_inode
);
288 iput(ecryptfs_inode
);
291 unlock_new_inode(ecryptfs_inode
);
292 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
297 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
299 struct ecryptfs_crypt_stat
*crypt_stat
;
302 rc
= ecryptfs_get_lower_file(dentry
, inode
);
304 printk(KERN_ERR
"%s: Error attempting to initialize "
305 "the lower file for the dentry with name "
306 "[%pd]; rc = [%d]\n", __func__
,
311 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
312 /* TODO: lock for crypt_stat comparison */
313 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
314 ecryptfs_set_default_sizes(crypt_stat
);
316 rc
= ecryptfs_read_and_validate_header_region(inode
);
317 ecryptfs_put_lower_file(inode
);
319 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
321 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
324 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
329 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
331 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
332 struct dentry
*lower_dentry
,
333 struct inode
*dir_inode
)
335 struct inode
*inode
, *lower_inode
= d_inode(lower_dentry
);
336 struct ecryptfs_dentry_info
*dentry_info
;
337 struct vfsmount
*lower_mnt
;
340 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
342 printk(KERN_ERR
"%s: Out of memory whilst attempting "
343 "to allocate ecryptfs_dentry_info struct\n",
349 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
350 fsstack_copy_attr_atime(dir_inode
, d_inode(lower_dentry
->d_parent
));
351 BUG_ON(!d_count(lower_dentry
));
353 ecryptfs_set_dentry_private(dentry
, dentry_info
);
354 dentry_info
->lower_path
.mnt
= lower_mnt
;
355 dentry_info
->lower_path
.dentry
= lower_dentry
;
357 if (d_really_is_negative(lower_dentry
)) {
358 /* We want to add because we couldn't find in lower */
362 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
364 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
365 __func__
, PTR_ERR(inode
));
366 return PTR_ERR(inode
);
368 if (S_ISREG(inode
->i_mode
)) {
369 rc
= ecryptfs_i_size_read(dentry
, inode
);
371 make_bad_inode(inode
);
376 if (inode
->i_state
& I_NEW
)
377 unlock_new_inode(inode
);
378 d_add(dentry
, inode
);
385 * @ecryptfs_dir_inode: The eCryptfs directory inode
386 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
387 * @ecryptfs_nd: nameidata; may be NULL
389 * Find a file on disk. If the file does not exist, then we'll add it to the
390 * dentry cache and continue on to read it from the disk.
392 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
393 struct dentry
*ecryptfs_dentry
,
396 char *encrypted_and_encoded_name
= NULL
;
397 size_t encrypted_and_encoded_name_size
;
398 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
399 struct dentry
*lower_dir_dentry
, *lower_dentry
;
402 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
403 mutex_lock(&d_inode(lower_dir_dentry
)->i_mutex
);
404 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
406 ecryptfs_dentry
->d_name
.len
);
407 mutex_unlock(&d_inode(lower_dir_dentry
)->i_mutex
);
408 if (IS_ERR(lower_dentry
)) {
409 rc
= PTR_ERR(lower_dentry
);
410 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
411 "[%d] on lower_dentry = [%pd]\n", __func__
, rc
,
415 if (d_really_is_positive(lower_dentry
))
417 mount_crypt_stat
= &ecryptfs_superblock_to_private(
418 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
419 if (!(mount_crypt_stat
420 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
423 rc
= ecryptfs_encrypt_and_encode_filename(
424 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
425 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
426 ecryptfs_dentry
->d_name
.len
);
428 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
429 "filename; rc = [%d]\n", __func__
, rc
);
432 mutex_lock(&d_inode(lower_dir_dentry
)->i_mutex
);
433 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
435 encrypted_and_encoded_name_size
);
436 mutex_unlock(&d_inode(lower_dir_dentry
)->i_mutex
);
437 if (IS_ERR(lower_dentry
)) {
438 rc
= PTR_ERR(lower_dentry
);
439 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
440 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
441 encrypted_and_encoded_name
);
445 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
448 kfree(encrypted_and_encoded_name
);
452 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
453 struct dentry
*new_dentry
)
455 struct dentry
*lower_old_dentry
;
456 struct dentry
*lower_new_dentry
;
457 struct dentry
*lower_dir_dentry
;
461 file_size_save
= i_size_read(d_inode(old_dentry
));
462 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
463 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
464 dget(lower_old_dentry
);
465 dget(lower_new_dentry
);
466 lower_dir_dentry
= lock_parent(lower_new_dentry
);
467 rc
= vfs_link(lower_old_dentry
, d_inode(lower_dir_dentry
),
468 lower_new_dentry
, NULL
);
469 if (rc
|| d_really_is_negative(lower_new_dentry
))
471 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
474 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
475 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
476 set_nlink(d_inode(old_dentry
),
477 ecryptfs_inode_to_lower(d_inode(old_dentry
))->i_nlink
);
478 i_size_write(d_inode(new_dentry
), file_size_save
);
480 unlock_dir(lower_dir_dentry
);
481 dput(lower_new_dentry
);
482 dput(lower_old_dentry
);
486 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
488 return ecryptfs_do_unlink(dir
, dentry
, d_inode(dentry
));
491 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
495 struct dentry
*lower_dentry
;
496 struct dentry
*lower_dir_dentry
;
497 char *encoded_symname
;
498 size_t encoded_symlen
;
499 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
501 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
503 lower_dir_dentry
= lock_parent(lower_dentry
);
504 mount_crypt_stat
= &ecryptfs_superblock_to_private(
505 dir
->i_sb
)->mount_crypt_stat
;
506 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
509 mount_crypt_stat
, symname
,
513 rc
= vfs_symlink(d_inode(lower_dir_dentry
), lower_dentry
,
515 kfree(encoded_symname
);
516 if (rc
|| d_really_is_negative(lower_dentry
))
518 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
521 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
522 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
524 unlock_dir(lower_dir_dentry
);
526 if (d_really_is_negative(dentry
))
531 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
534 struct dentry
*lower_dentry
;
535 struct dentry
*lower_dir_dentry
;
537 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
538 lower_dir_dentry
= lock_parent(lower_dentry
);
539 rc
= vfs_mkdir(d_inode(lower_dir_dentry
), lower_dentry
, mode
);
540 if (rc
|| d_really_is_negative(lower_dentry
))
542 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
545 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
546 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
547 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
549 unlock_dir(lower_dir_dentry
);
550 if (d_really_is_negative(dentry
))
555 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
557 struct dentry
*lower_dentry
;
558 struct dentry
*lower_dir_dentry
;
561 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
563 lower_dir_dentry
= lock_parent(lower_dentry
);
565 rc
= vfs_rmdir(d_inode(lower_dir_dentry
), lower_dentry
);
567 if (!rc
&& d_really_is_positive(dentry
))
568 clear_nlink(d_inode(dentry
));
569 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
570 set_nlink(dir
, d_inode(lower_dir_dentry
)->i_nlink
);
571 unlock_dir(lower_dir_dentry
);
579 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
582 struct dentry
*lower_dentry
;
583 struct dentry
*lower_dir_dentry
;
585 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
586 lower_dir_dentry
= lock_parent(lower_dentry
);
587 rc
= vfs_mknod(d_inode(lower_dir_dentry
), lower_dentry
, mode
, dev
);
588 if (rc
|| d_really_is_negative(lower_dentry
))
590 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
593 fsstack_copy_attr_times(dir
, d_inode(lower_dir_dentry
));
594 fsstack_copy_inode_size(dir
, d_inode(lower_dir_dentry
));
596 unlock_dir(lower_dir_dentry
);
597 if (d_really_is_negative(dentry
))
603 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
604 struct inode
*new_dir
, struct dentry
*new_dentry
)
607 struct dentry
*lower_old_dentry
;
608 struct dentry
*lower_new_dentry
;
609 struct dentry
*lower_old_dir_dentry
;
610 struct dentry
*lower_new_dir_dentry
;
611 struct dentry
*trap
= NULL
;
612 struct inode
*target_inode
;
614 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
615 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
616 dget(lower_old_dentry
);
617 dget(lower_new_dentry
);
618 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
619 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
620 target_inode
= d_inode(new_dentry
);
621 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
622 /* source should not be ancestor of target */
623 if (trap
== lower_old_dentry
) {
627 /* target should not be ancestor of source */
628 if (trap
== lower_new_dentry
) {
632 rc
= vfs_rename(d_inode(lower_old_dir_dentry
), lower_old_dentry
,
633 d_inode(lower_new_dir_dentry
), lower_new_dentry
,
638 fsstack_copy_attr_all(target_inode
,
639 ecryptfs_inode_to_lower(target_inode
));
640 fsstack_copy_attr_all(new_dir
, d_inode(lower_new_dir_dentry
));
641 if (new_dir
!= old_dir
)
642 fsstack_copy_attr_all(old_dir
, d_inode(lower_old_dir_dentry
));
644 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
645 dput(lower_new_dir_dentry
);
646 dput(lower_old_dir_dentry
);
647 dput(lower_new_dentry
);
648 dput(lower_old_dentry
);
652 static char *ecryptfs_readlink_lower(struct dentry
*dentry
, size_t *bufsiz
)
654 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
660 lower_buf
= kmalloc(PATH_MAX
, GFP_KERNEL
);
662 return ERR_PTR(-ENOMEM
);
665 rc
= d_inode(lower_dentry
)->i_op
->readlink(lower_dentry
,
666 (char __user
*)lower_buf
,
671 rc
= ecryptfs_decode_and_decrypt_filename(&buf
, bufsiz
, dentry
->d_sb
,
675 return rc
? ERR_PTR(rc
) : buf
;
678 static const char *ecryptfs_follow_link(struct dentry
*dentry
, void **cookie
, struct nameidata
*nd
)
681 char *buf
= ecryptfs_readlink_lower(dentry
, &len
);
684 fsstack_copy_attr_atime(d_inode(dentry
),
685 d_inode(ecryptfs_dentry_to_lower(dentry
)));
687 return *cookie
= buf
;
691 * upper_size_to_lower_size
692 * @crypt_stat: Crypt_stat associated with file
693 * @upper_size: Size of the upper file
695 * Calculate the required size of the lower file based on the
696 * specified size of the upper file. This calculation is based on the
697 * number of headers in the underlying file and the extent size.
699 * Returns Calculated size of the lower file.
702 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
707 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
708 if (upper_size
!= 0) {
711 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
712 if (upper_size
& ~crypt_stat
->extent_mask
)
714 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
721 * @dentry: The ecryptfs layer dentry
722 * @ia: Address of the ecryptfs inode's attributes
723 * @lower_ia: Address of the lower inode's attributes
725 * Function to handle truncations modifying the size of the file. Note
726 * that the file sizes are interpolated. When expanding, we are simply
727 * writing strings of 0's out. When truncating, we truncate the upper
728 * inode and update the lower_ia according to the page index
729 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
730 * the caller must use lower_ia in a call to notify_change() to perform
731 * the truncation of the lower inode.
733 * Returns zero on success; non-zero otherwise
735 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
736 struct iattr
*lower_ia
)
739 struct inode
*inode
= d_inode(dentry
);
740 struct ecryptfs_crypt_stat
*crypt_stat
;
741 loff_t i_size
= i_size_read(inode
);
742 loff_t lower_size_before_truncate
;
743 loff_t lower_size_after_truncate
;
745 if (unlikely((ia
->ia_size
== i_size
))) {
746 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
749 rc
= ecryptfs_get_lower_file(dentry
, inode
);
752 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
753 /* Switch on growing or shrinking file */
754 if (ia
->ia_size
> i_size
) {
755 char zero
[] = { 0x00 };
757 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
758 /* Write a single 0 at the last position of the file;
759 * this triggers code that will fill in 0's throughout
760 * the intermediate portion of the previous end of the
761 * file and the new and of the file */
762 rc
= ecryptfs_write(inode
, zero
,
763 (ia
->ia_size
- 1), 1);
764 } else { /* ia->ia_size < i_size_read(inode) */
765 /* We're chopping off all the pages down to the page
766 * in which ia->ia_size is located. Fill in the end of
767 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
768 * PAGE_CACHE_SIZE with zeros. */
769 size_t num_zeros
= (PAGE_CACHE_SIZE
770 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
772 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
773 truncate_setsize(inode
, ia
->ia_size
);
774 lower_ia
->ia_size
= ia
->ia_size
;
775 lower_ia
->ia_valid
|= ATTR_SIZE
;
781 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
786 rc
= ecryptfs_write(inode
, zeros_virt
,
787 ia
->ia_size
, num_zeros
);
790 printk(KERN_ERR
"Error attempting to zero out "
791 "the remainder of the end page on "
792 "reducing truncate; rc = [%d]\n", rc
);
796 truncate_setsize(inode
, ia
->ia_size
);
797 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
799 printk(KERN_ERR
"Problem with "
800 "ecryptfs_write_inode_size_to_metadata; "
804 /* We are reducing the size of the ecryptfs file, and need to
805 * know if we need to reduce the size of the lower file. */
806 lower_size_before_truncate
=
807 upper_size_to_lower_size(crypt_stat
, i_size
);
808 lower_size_after_truncate
=
809 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
810 if (lower_size_after_truncate
< lower_size_before_truncate
) {
811 lower_ia
->ia_size
= lower_size_after_truncate
;
812 lower_ia
->ia_valid
|= ATTR_SIZE
;
814 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
817 ecryptfs_put_lower_file(inode
);
821 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
823 struct ecryptfs_crypt_stat
*crypt_stat
;
824 loff_t lower_oldsize
, lower_newsize
;
826 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
827 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
829 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
830 if (lower_newsize
> lower_oldsize
) {
832 * The eCryptfs inode and the new *lower* size are mixed here
833 * because we may not have the lower i_mutex held and/or it may
834 * not be appropriate to call inode_newsize_ok() with inodes
835 * from other filesystems.
837 return inode_newsize_ok(inode
, lower_newsize
);
845 * @dentry: The ecryptfs layer dentry
846 * @new_length: The length to expand the file to
848 * Simple function that handles the truncation of an eCryptfs inode and
849 * its corresponding lower inode.
851 * Returns zero on success; non-zero otherwise
853 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
855 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
856 struct iattr lower_ia
= { .ia_valid
= 0 };
859 rc
= ecryptfs_inode_newsize_ok(d_inode(dentry
), new_length
);
863 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
864 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
865 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
867 mutex_lock(&d_inode(lower_dentry
)->i_mutex
);
868 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
869 mutex_unlock(&d_inode(lower_dentry
)->i_mutex
);
875 ecryptfs_permission(struct inode
*inode
, int mask
)
877 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
882 * @dentry: dentry handle to the inode to modify
883 * @ia: Structure with flags of what to change and values
885 * Updates the metadata of an inode. If the update is to the size
886 * i.e. truncation, then ecryptfs_truncate will handle the size modification
887 * of both the ecryptfs inode and the lower inode.
889 * All other metadata changes will be passed right to the lower filesystem,
890 * and we will just update our inode to look like the lower.
892 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
895 struct dentry
*lower_dentry
;
896 struct iattr lower_ia
;
898 struct inode
*lower_inode
;
899 struct ecryptfs_crypt_stat
*crypt_stat
;
901 crypt_stat
= &ecryptfs_inode_to_private(d_inode(dentry
))->crypt_stat
;
902 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
903 ecryptfs_init_crypt_stat(crypt_stat
);
904 inode
= d_inode(dentry
);
905 lower_inode
= ecryptfs_inode_to_lower(inode
);
906 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
907 mutex_lock(&crypt_stat
->cs_mutex
);
908 if (d_is_dir(dentry
))
909 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
910 else if (d_is_reg(dentry
)
911 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
912 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
913 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
915 mount_crypt_stat
= &ecryptfs_superblock_to_private(
916 dentry
->d_sb
)->mount_crypt_stat
;
917 rc
= ecryptfs_get_lower_file(dentry
, inode
);
919 mutex_unlock(&crypt_stat
->cs_mutex
);
922 rc
= ecryptfs_read_metadata(dentry
);
923 ecryptfs_put_lower_file(inode
);
925 if (!(mount_crypt_stat
->flags
926 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
928 printk(KERN_WARNING
"Either the lower file "
929 "is not in a valid eCryptfs format, "
930 "or the key could not be retrieved. "
931 "Plaintext passthrough mode is not "
932 "enabled; returning -EIO\n");
933 mutex_unlock(&crypt_stat
->cs_mutex
);
937 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
938 | ECRYPTFS_ENCRYPTED
);
941 mutex_unlock(&crypt_stat
->cs_mutex
);
943 rc
= inode_change_ok(inode
, ia
);
946 if (ia
->ia_valid
& ATTR_SIZE
) {
947 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
952 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
953 if (ia
->ia_valid
& ATTR_FILE
)
954 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
955 if (ia
->ia_valid
& ATTR_SIZE
) {
956 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
962 * mode change is for clearing setuid/setgid bits. Allow lower fs
963 * to interpret this in its own way.
965 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
966 lower_ia
.ia_valid
&= ~ATTR_MODE
;
968 mutex_lock(&d_inode(lower_dentry
)->i_mutex
);
969 rc
= notify_change(lower_dentry
, &lower_ia
, NULL
);
970 mutex_unlock(&d_inode(lower_dentry
)->i_mutex
);
972 fsstack_copy_attr_all(inode
, lower_inode
);
976 static int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
979 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
982 mount_crypt_stat
= &ecryptfs_superblock_to_private(
983 dentry
->d_sb
)->mount_crypt_stat
;
984 generic_fillattr(d_inode(dentry
), stat
);
985 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
989 target
= ecryptfs_readlink_lower(dentry
, &targetsiz
);
990 if (!IS_ERR(target
)) {
992 stat
->size
= targetsiz
;
994 rc
= PTR_ERR(target
);
1000 static int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1003 struct kstat lower_stat
;
1006 rc
= vfs_getattr(ecryptfs_dentry_to_lower_path(dentry
), &lower_stat
);
1008 fsstack_copy_attr_all(d_inode(dentry
),
1009 ecryptfs_inode_to_lower(d_inode(dentry
)));
1010 generic_fillattr(d_inode(dentry
), stat
);
1011 stat
->blocks
= lower_stat
.blocks
;
1017 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1018 size_t size
, int flags
)
1021 struct dentry
*lower_dentry
;
1023 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1024 if (!d_inode(lower_dentry
)->i_op
->setxattr
) {
1029 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1030 if (!rc
&& d_really_is_positive(dentry
))
1031 fsstack_copy_attr_all(d_inode(dentry
), d_inode(lower_dentry
));
1037 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1038 void *value
, size_t size
)
1042 if (!d_inode(lower_dentry
)->i_op
->getxattr
) {
1046 mutex_lock(&d_inode(lower_dentry
)->i_mutex
);
1047 rc
= d_inode(lower_dentry
)->i_op
->getxattr(lower_dentry
, name
, value
,
1049 mutex_unlock(&d_inode(lower_dentry
)->i_mutex
);
1055 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1058 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1063 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1066 struct dentry
*lower_dentry
;
1068 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1069 if (!d_inode(lower_dentry
)->i_op
->listxattr
) {
1073 mutex_lock(&d_inode(lower_dentry
)->i_mutex
);
1074 rc
= d_inode(lower_dentry
)->i_op
->listxattr(lower_dentry
, list
, size
);
1075 mutex_unlock(&d_inode(lower_dentry
)->i_mutex
);
1080 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1083 struct dentry
*lower_dentry
;
1085 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1086 if (!d_inode(lower_dentry
)->i_op
->removexattr
) {
1090 mutex_lock(&d_inode(lower_dentry
)->i_mutex
);
1091 rc
= d_inode(lower_dentry
)->i_op
->removexattr(lower_dentry
, name
);
1092 mutex_unlock(&d_inode(lower_dentry
)->i_mutex
);
1097 const struct inode_operations ecryptfs_symlink_iops
= {
1098 .readlink
= generic_readlink
,
1099 .follow_link
= ecryptfs_follow_link
,
1100 .put_link
= kfree_put_link
,
1101 .permission
= ecryptfs_permission
,
1102 .setattr
= ecryptfs_setattr
,
1103 .getattr
= ecryptfs_getattr_link
,
1104 .setxattr
= ecryptfs_setxattr
,
1105 .getxattr
= ecryptfs_getxattr
,
1106 .listxattr
= ecryptfs_listxattr
,
1107 .removexattr
= ecryptfs_removexattr
1110 const struct inode_operations ecryptfs_dir_iops
= {
1111 .create
= ecryptfs_create
,
1112 .lookup
= ecryptfs_lookup
,
1113 .link
= ecryptfs_link
,
1114 .unlink
= ecryptfs_unlink
,
1115 .symlink
= ecryptfs_symlink
,
1116 .mkdir
= ecryptfs_mkdir
,
1117 .rmdir
= ecryptfs_rmdir
,
1118 .mknod
= ecryptfs_mknod
,
1119 .rename
= ecryptfs_rename
,
1120 .permission
= ecryptfs_permission
,
1121 .setattr
= ecryptfs_setattr
,
1122 .setxattr
= ecryptfs_setxattr
,
1123 .getxattr
= ecryptfs_getxattr
,
1124 .listxattr
= ecryptfs_listxattr
,
1125 .removexattr
= ecryptfs_removexattr
1128 const struct inode_operations ecryptfs_main_iops
= {
1129 .permission
= ecryptfs_permission
,
1130 .setattr
= ecryptfs_setattr
,
1131 .getattr
= ecryptfs_getattr
,
1132 .setxattr
= ecryptfs_setxattr
,
1133 .getxattr
= ecryptfs_getxattr
,
1134 .listxattr
= ecryptfs_listxattr
,
1135 .removexattr
= ecryptfs_removexattr