2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry
*lock_parent(struct dentry
*dentry
)
43 dir
= dget_parent(dentry
);
44 mutex_lock_nested(&(dir
->d_inode
->i_mutex
), I_MUTEX_PARENT
);
48 static void unlock_dir(struct dentry
*dir
)
50 mutex_unlock(&dir
->d_inode
->i_mutex
);
54 static int ecryptfs_inode_test(struct inode
*inode
, void *lower_inode
)
56 if (ecryptfs_inode_to_lower(inode
) == (struct inode
*)lower_inode
)
61 static int ecryptfs_inode_set(struct inode
*inode
, void *opaque
)
63 struct inode
*lower_inode
= opaque
;
65 ecryptfs_set_inode_lower(inode
, lower_inode
);
66 fsstack_copy_attr_all(inode
, lower_inode
);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode
, lower_inode
);
69 inode
->i_ino
= lower_inode
->i_ino
;
71 inode
->i_mapping
->a_ops
= &ecryptfs_aops
;
72 inode
->i_mapping
->backing_dev_info
= inode
->i_sb
->s_bdi
;
74 if (S_ISLNK(inode
->i_mode
))
75 inode
->i_op
= &ecryptfs_symlink_iops
;
76 else if (S_ISDIR(inode
->i_mode
))
77 inode
->i_op
= &ecryptfs_dir_iops
;
79 inode
->i_op
= &ecryptfs_main_iops
;
81 if (S_ISDIR(inode
->i_mode
))
82 inode
->i_fop
= &ecryptfs_dir_fops
;
83 else if (special_file(inode
->i_mode
))
84 init_special_inode(inode
, inode
->i_mode
, inode
->i_rdev
);
86 inode
->i_fop
= &ecryptfs_main_fops
;
91 static struct inode
*__ecryptfs_get_inode(struct inode
*lower_inode
,
92 struct super_block
*sb
)
96 if (lower_inode
->i_sb
!= ecryptfs_superblock_to_lower(sb
))
97 return ERR_PTR(-EXDEV
);
98 if (!igrab(lower_inode
))
99 return ERR_PTR(-ESTALE
);
100 inode
= iget5_locked(sb
, (unsigned long)lower_inode
,
101 ecryptfs_inode_test
, ecryptfs_inode_set
,
105 return ERR_PTR(-EACCES
);
107 if (!(inode
->i_state
& I_NEW
))
113 struct inode
*ecryptfs_get_inode(struct inode
*lower_inode
,
114 struct super_block
*sb
)
116 struct inode
*inode
= __ecryptfs_get_inode(lower_inode
, sb
);
118 if (!IS_ERR(inode
) && (inode
->i_state
& I_NEW
))
119 unlock_new_inode(inode
);
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
130 * Interposes upper and lower dentries.
132 * Returns zero on success; non-zero otherwise
134 static int ecryptfs_interpose(struct dentry
*lower_dentry
,
135 struct dentry
*dentry
, struct super_block
*sb
)
137 struct inode
*inode
= ecryptfs_get_inode(lower_dentry
->d_inode
, sb
);
140 return PTR_ERR(inode
);
141 d_instantiate(dentry
, inode
);
148 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
149 * @ecryptfs_dentry: New file's dentry in ecryptfs
150 * @mode: The mode of the new file
151 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
153 * Creates the underlying file and the eCryptfs inode which will link to
154 * it. It will also update the eCryptfs directory inode to mimic the
155 * stat of the lower directory inode.
157 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
159 static struct inode
*
160 ecryptfs_do_create(struct inode
*directory_inode
,
161 struct dentry
*ecryptfs_dentry
, umode_t mode
)
164 struct dentry
*lower_dentry
;
165 struct dentry
*lower_dir_dentry
;
168 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
169 lower_dir_dentry
= lock_parent(lower_dentry
);
170 if (IS_ERR(lower_dir_dentry
)) {
171 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
173 inode
= ERR_CAST(lower_dir_dentry
);
176 rc
= vfs_create(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, NULL
);
178 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
179 "rc = [%d]\n", __func__
, rc
);
183 inode
= __ecryptfs_get_inode(lower_dentry
->d_inode
,
184 directory_inode
->i_sb
);
187 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
188 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
190 unlock_dir(lower_dir_dentry
);
196 * ecryptfs_initialize_file
198 * Cause the file to be changed from a basic empty file to an ecryptfs
199 * file with a header and first data page.
201 * Returns zero on success
203 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
,
204 struct inode
*ecryptfs_inode
)
206 struct ecryptfs_crypt_stat
*crypt_stat
=
207 &ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
;
210 if (S_ISDIR(ecryptfs_inode
->i_mode
)) {
211 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
212 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
215 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
216 rc
= ecryptfs_new_file_context(ecryptfs_inode
);
218 ecryptfs_printk(KERN_ERR
, "Error creating new file "
219 "context; rc = [%d]\n", rc
);
222 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
, ecryptfs_inode
);
224 printk(KERN_ERR
"%s: Error attempting to initialize "
225 "the lower file for the dentry with name "
226 "[%s]; rc = [%d]\n", __func__
,
227 ecryptfs_dentry
->d_name
.name
, rc
);
230 rc
= ecryptfs_write_metadata(ecryptfs_dentry
, ecryptfs_inode
);
232 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
233 ecryptfs_put_lower_file(ecryptfs_inode
);
240 * @dir: The inode of the directory in which to create the file.
241 * @dentry: The eCryptfs dentry
242 * @mode: The mode of the new file.
245 * Creates a new file.
247 * Returns zero on success; non-zero on error condition
250 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
251 umode_t mode
, struct nameidata
*nd
)
253 struct inode
*ecryptfs_inode
;
256 ecryptfs_inode
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
,
258 if (unlikely(IS_ERR(ecryptfs_inode
))) {
259 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
260 "lower filesystem\n");
261 rc
= PTR_ERR(ecryptfs_inode
);
264 /* At this point, a file exists on "disk"; we need to make sure
265 * that this on disk file is prepared to be an ecryptfs file */
266 rc
= ecryptfs_initialize_file(ecryptfs_dentry
, ecryptfs_inode
);
268 drop_nlink(ecryptfs_inode
);
269 unlock_new_inode(ecryptfs_inode
);
270 iput(ecryptfs_inode
);
273 d_instantiate(ecryptfs_dentry
, ecryptfs_inode
);
274 unlock_new_inode(ecryptfs_inode
);
279 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
281 struct ecryptfs_crypt_stat
*crypt_stat
;
284 rc
= ecryptfs_get_lower_file(dentry
, inode
);
286 printk(KERN_ERR
"%s: Error attempting to initialize "
287 "the lower file for the dentry with name "
288 "[%s]; rc = [%d]\n", __func__
,
289 dentry
->d_name
.name
, rc
);
293 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
294 /* TODO: lock for crypt_stat comparison */
295 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
296 ecryptfs_set_default_sizes(crypt_stat
);
298 rc
= ecryptfs_read_and_validate_header_region(inode
);
299 ecryptfs_put_lower_file(inode
);
301 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
303 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
306 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
311 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
313 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
314 struct dentry
*lower_dentry
,
315 struct inode
*dir_inode
)
317 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
318 struct ecryptfs_dentry_info
*dentry_info
;
319 struct vfsmount
*lower_mnt
;
322 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
323 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
324 BUG_ON(!lower_dentry
->d_count
);
326 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
327 ecryptfs_set_dentry_private(dentry
, dentry_info
);
329 printk(KERN_ERR
"%s: Out of memory whilst attempting "
330 "to allocate ecryptfs_dentry_info struct\n",
337 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
338 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
340 if (!lower_dentry
->d_inode
) {
341 /* We want to add because we couldn't find in lower */
345 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
347 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
348 __func__
, PTR_ERR(inode
));
349 return PTR_ERR(inode
);
351 if (S_ISREG(inode
->i_mode
)) {
352 rc
= ecryptfs_i_size_read(dentry
, inode
);
354 make_bad_inode(inode
);
359 if (inode
->i_state
& I_NEW
)
360 unlock_new_inode(inode
);
361 d_add(dentry
, inode
);
368 * @ecryptfs_dir_inode: The eCryptfs directory inode
369 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
370 * @ecryptfs_nd: nameidata; may be NULL
372 * Find a file on disk. If the file does not exist, then we'll add it to the
373 * dentry cache and continue on to read it from the disk.
375 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
376 struct dentry
*ecryptfs_dentry
,
377 struct nameidata
*ecryptfs_nd
)
379 char *encrypted_and_encoded_name
= NULL
;
380 size_t encrypted_and_encoded_name_size
;
381 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
382 struct dentry
*lower_dir_dentry
, *lower_dentry
;
385 if ((ecryptfs_dentry
->d_name
.len
== 1
386 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
387 || (ecryptfs_dentry
->d_name
.len
== 2
388 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
391 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
392 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
393 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
395 ecryptfs_dentry
->d_name
.len
);
396 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
397 if (IS_ERR(lower_dentry
)) {
398 rc
= PTR_ERR(lower_dentry
);
399 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
400 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
401 encrypted_and_encoded_name
);
404 if (lower_dentry
->d_inode
)
406 mount_crypt_stat
= &ecryptfs_superblock_to_private(
407 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
408 if (!(mount_crypt_stat
409 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
412 rc
= ecryptfs_encrypt_and_encode_filename(
413 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
414 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
415 ecryptfs_dentry
->d_name
.len
);
417 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
418 "filename; rc = [%d]\n", __func__
, rc
);
421 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
422 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
424 encrypted_and_encoded_name_size
);
425 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
426 if (IS_ERR(lower_dentry
)) {
427 rc
= PTR_ERR(lower_dentry
);
428 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
429 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
430 encrypted_and_encoded_name
);
434 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
438 d_drop(ecryptfs_dentry
);
440 kfree(encrypted_and_encoded_name
);
444 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
445 struct dentry
*new_dentry
)
447 struct dentry
*lower_old_dentry
;
448 struct dentry
*lower_new_dentry
;
449 struct dentry
*lower_dir_dentry
;
453 file_size_save
= i_size_read(old_dentry
->d_inode
);
454 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
455 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
456 dget(lower_old_dentry
);
457 dget(lower_new_dentry
);
458 lower_dir_dentry
= lock_parent(lower_new_dentry
);
459 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
461 if (rc
|| !lower_new_dentry
->d_inode
)
463 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
466 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
467 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
468 set_nlink(old_dentry
->d_inode
,
469 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
);
470 i_size_write(new_dentry
->d_inode
, file_size_save
);
472 unlock_dir(lower_dir_dentry
);
473 dput(lower_new_dentry
);
474 dput(lower_old_dentry
);
478 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
481 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
482 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
483 struct dentry
*lower_dir_dentry
;
486 lower_dir_dentry
= lock_parent(lower_dentry
);
487 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
489 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
492 fsstack_copy_attr_times(dir
, lower_dir_inode
);
493 set_nlink(dentry
->d_inode
,
494 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
);
495 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
498 unlock_dir(lower_dir_dentry
);
503 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
507 struct dentry
*lower_dentry
;
508 struct dentry
*lower_dir_dentry
;
509 char *encoded_symname
;
510 size_t encoded_symlen
;
511 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
513 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
515 lower_dir_dentry
= lock_parent(lower_dentry
);
516 mount_crypt_stat
= &ecryptfs_superblock_to_private(
517 dir
->i_sb
)->mount_crypt_stat
;
518 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
521 mount_crypt_stat
, symname
,
525 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
527 kfree(encoded_symname
);
528 if (rc
|| !lower_dentry
->d_inode
)
530 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
533 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
534 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
536 unlock_dir(lower_dir_dentry
);
538 if (!dentry
->d_inode
)
543 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
)
546 struct dentry
*lower_dentry
;
547 struct dentry
*lower_dir_dentry
;
549 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
550 lower_dir_dentry
= lock_parent(lower_dentry
);
551 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
552 if (rc
|| !lower_dentry
->d_inode
)
554 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
557 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
558 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
559 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
561 unlock_dir(lower_dir_dentry
);
562 if (!dentry
->d_inode
)
567 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
569 struct dentry
*lower_dentry
;
570 struct dentry
*lower_dir_dentry
;
573 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
575 lower_dir_dentry
= lock_parent(lower_dentry
);
577 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
579 if (!rc
&& dentry
->d_inode
)
580 clear_nlink(dentry
->d_inode
);
581 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
582 set_nlink(dir
, lower_dir_dentry
->d_inode
->i_nlink
);
583 unlock_dir(lower_dir_dentry
);
591 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, umode_t mode
, dev_t dev
)
594 struct dentry
*lower_dentry
;
595 struct dentry
*lower_dir_dentry
;
597 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
598 lower_dir_dentry
= lock_parent(lower_dentry
);
599 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
600 if (rc
|| !lower_dentry
->d_inode
)
602 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
605 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
606 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
608 unlock_dir(lower_dir_dentry
);
609 if (!dentry
->d_inode
)
615 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
616 struct inode
*new_dir
, struct dentry
*new_dentry
)
619 struct dentry
*lower_old_dentry
;
620 struct dentry
*lower_new_dentry
;
621 struct dentry
*lower_old_dir_dentry
;
622 struct dentry
*lower_new_dir_dentry
;
623 struct dentry
*trap
= NULL
;
625 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
626 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
627 dget(lower_old_dentry
);
628 dget(lower_new_dentry
);
629 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
630 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
631 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
632 /* source should not be ancestor of target */
633 if (trap
== lower_old_dentry
) {
637 /* target should not be ancestor of source */
638 if (trap
== lower_new_dentry
) {
642 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
643 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
646 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
647 if (new_dir
!= old_dir
)
648 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
650 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
651 dput(lower_new_dir_dentry
);
652 dput(lower_old_dir_dentry
);
653 dput(lower_new_dentry
);
654 dput(lower_old_dentry
);
658 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
661 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
663 size_t lower_bufsiz
= PATH_MAX
;
667 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
674 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
675 (char __user
*)lower_buf
,
681 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
682 lower_buf
, lower_bufsiz
);
689 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
692 size_t kbufsiz
, copied
;
695 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
698 copied
= min_t(size_t, bufsiz
, kbufsiz
);
699 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
701 fsstack_copy_attr_atime(dentry
->d_inode
,
702 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
707 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
710 int len
= PAGE_SIZE
, rc
;
713 /* Released in ecryptfs_put_link(); only release here on error */
714 buf
= kmalloc(len
, GFP_KERNEL
);
716 buf
= ERR_PTR(-ENOMEM
);
721 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
729 nd_set_link(nd
, buf
);
734 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
736 char *buf
= nd_get_link(nd
);
744 * upper_size_to_lower_size
745 * @crypt_stat: Crypt_stat associated with file
746 * @upper_size: Size of the upper file
748 * Calculate the required size of the lower file based on the
749 * specified size of the upper file. This calculation is based on the
750 * number of headers in the underlying file and the extent size.
752 * Returns Calculated size of the lower file.
755 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
760 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
761 if (upper_size
!= 0) {
764 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
765 if (upper_size
& ~crypt_stat
->extent_mask
)
767 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
774 * @dentry: The ecryptfs layer dentry
775 * @ia: Address of the ecryptfs inode's attributes
776 * @lower_ia: Address of the lower inode's attributes
778 * Function to handle truncations modifying the size of the file. Note
779 * that the file sizes are interpolated. When expanding, we are simply
780 * writing strings of 0's out. When truncating, we truncate the upper
781 * inode and update the lower_ia according to the page index
782 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
783 * the caller must use lower_ia in a call to notify_change() to perform
784 * the truncation of the lower inode.
786 * Returns zero on success; non-zero otherwise
788 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
789 struct iattr
*lower_ia
)
792 struct inode
*inode
= dentry
->d_inode
;
793 struct ecryptfs_crypt_stat
*crypt_stat
;
794 loff_t i_size
= i_size_read(inode
);
795 loff_t lower_size_before_truncate
;
796 loff_t lower_size_after_truncate
;
798 if (unlikely((ia
->ia_size
== i_size
))) {
799 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
802 rc
= ecryptfs_get_lower_file(dentry
, inode
);
805 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
806 /* Switch on growing or shrinking file */
807 if (ia
->ia_size
> i_size
) {
808 char zero
[] = { 0x00 };
810 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
811 /* Write a single 0 at the last position of the file;
812 * this triggers code that will fill in 0's throughout
813 * the intermediate portion of the previous end of the
814 * file and the new and of the file */
815 rc
= ecryptfs_write(inode
, zero
,
816 (ia
->ia_size
- 1), 1);
817 } else { /* ia->ia_size < i_size_read(inode) */
818 /* We're chopping off all the pages down to the page
819 * in which ia->ia_size is located. Fill in the end of
820 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
821 * PAGE_CACHE_SIZE with zeros. */
822 size_t num_zeros
= (PAGE_CACHE_SIZE
823 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
825 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
826 truncate_setsize(inode
, ia
->ia_size
);
827 lower_ia
->ia_size
= ia
->ia_size
;
828 lower_ia
->ia_valid
|= ATTR_SIZE
;
834 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
839 rc
= ecryptfs_write(inode
, zeros_virt
,
840 ia
->ia_size
, num_zeros
);
843 printk(KERN_ERR
"Error attempting to zero out "
844 "the remainder of the end page on "
845 "reducing truncate; rc = [%d]\n", rc
);
849 truncate_setsize(inode
, ia
->ia_size
);
850 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
852 printk(KERN_ERR
"Problem with "
853 "ecryptfs_write_inode_size_to_metadata; "
857 /* We are reducing the size of the ecryptfs file, and need to
858 * know if we need to reduce the size of the lower file. */
859 lower_size_before_truncate
=
860 upper_size_to_lower_size(crypt_stat
, i_size
);
861 lower_size_after_truncate
=
862 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
863 if (lower_size_after_truncate
< lower_size_before_truncate
) {
864 lower_ia
->ia_size
= lower_size_after_truncate
;
865 lower_ia
->ia_valid
|= ATTR_SIZE
;
867 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
870 ecryptfs_put_lower_file(inode
);
874 static int ecryptfs_inode_newsize_ok(struct inode
*inode
, loff_t offset
)
876 struct ecryptfs_crypt_stat
*crypt_stat
;
877 loff_t lower_oldsize
, lower_newsize
;
879 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
880 lower_oldsize
= upper_size_to_lower_size(crypt_stat
,
882 lower_newsize
= upper_size_to_lower_size(crypt_stat
, offset
);
883 if (lower_newsize
> lower_oldsize
) {
885 * The eCryptfs inode and the new *lower* size are mixed here
886 * because we may not have the lower i_mutex held and/or it may
887 * not be appropriate to call inode_newsize_ok() with inodes
888 * from other filesystems.
890 return inode_newsize_ok(inode
, lower_newsize
);
898 * @dentry: The ecryptfs layer dentry
899 * @new_length: The length to expand the file to
901 * Simple function that handles the truncation of an eCryptfs inode and
902 * its corresponding lower inode.
904 * Returns zero on success; non-zero otherwise
906 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
908 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
909 struct iattr lower_ia
= { .ia_valid
= 0 };
912 rc
= ecryptfs_inode_newsize_ok(dentry
->d_inode
, new_length
);
916 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
917 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
918 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
920 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
921 rc
= notify_change(lower_dentry
, &lower_ia
);
922 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
928 ecryptfs_permission(struct inode
*inode
, int mask
)
930 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
935 * @dentry: dentry handle to the inode to modify
936 * @ia: Structure with flags of what to change and values
938 * Updates the metadata of an inode. If the update is to the size
939 * i.e. truncation, then ecryptfs_truncate will handle the size modification
940 * of both the ecryptfs inode and the lower inode.
942 * All other metadata changes will be passed right to the lower filesystem,
943 * and we will just update our inode to look like the lower.
945 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
948 struct dentry
*lower_dentry
;
949 struct iattr lower_ia
;
951 struct inode
*lower_inode
;
952 struct ecryptfs_crypt_stat
*crypt_stat
;
954 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
955 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
956 ecryptfs_init_crypt_stat(crypt_stat
);
957 inode
= dentry
->d_inode
;
958 lower_inode
= ecryptfs_inode_to_lower(inode
);
959 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
960 mutex_lock(&crypt_stat
->cs_mutex
);
961 if (S_ISDIR(dentry
->d_inode
->i_mode
))
962 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
963 else if (S_ISREG(dentry
->d_inode
->i_mode
)
964 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
965 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
966 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
968 mount_crypt_stat
= &ecryptfs_superblock_to_private(
969 dentry
->d_sb
)->mount_crypt_stat
;
970 rc
= ecryptfs_get_lower_file(dentry
, inode
);
972 mutex_unlock(&crypt_stat
->cs_mutex
);
975 rc
= ecryptfs_read_metadata(dentry
);
976 ecryptfs_put_lower_file(inode
);
978 if (!(mount_crypt_stat
->flags
979 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
981 printk(KERN_WARNING
"Either the lower file "
982 "is not in a valid eCryptfs format, "
983 "or the key could not be retrieved. "
984 "Plaintext passthrough mode is not "
985 "enabled; returning -EIO\n");
986 mutex_unlock(&crypt_stat
->cs_mutex
);
990 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
991 | ECRYPTFS_ENCRYPTED
);
994 mutex_unlock(&crypt_stat
->cs_mutex
);
996 rc
= inode_change_ok(inode
, ia
);
999 if (ia
->ia_valid
& ATTR_SIZE
) {
1000 rc
= ecryptfs_inode_newsize_ok(inode
, ia
->ia_size
);
1005 if (S_ISREG(inode
->i_mode
)) {
1006 rc
= filemap_write_and_wait(inode
->i_mapping
);
1009 fsstack_copy_attr_all(inode
, lower_inode
);
1011 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
1012 if (ia
->ia_valid
& ATTR_FILE
)
1013 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
1014 if (ia
->ia_valid
& ATTR_SIZE
) {
1015 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1021 * mode change is for clearing setuid/setgid bits. Allow lower fs
1022 * to interpret this in its own way.
1024 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1025 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1027 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1028 rc
= notify_change(lower_dentry
, &lower_ia
);
1029 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1031 fsstack_copy_attr_all(inode
, lower_inode
);
1035 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1038 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1041 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1042 dentry
->d_sb
)->mount_crypt_stat
;
1043 generic_fillattr(dentry
->d_inode
, stat
);
1044 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1048 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1051 stat
->size
= targetsiz
;
1057 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1060 struct kstat lower_stat
;
1063 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1064 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1066 fsstack_copy_attr_all(dentry
->d_inode
,
1067 ecryptfs_inode_to_lower(dentry
->d_inode
));
1068 generic_fillattr(dentry
->d_inode
, stat
);
1069 stat
->blocks
= lower_stat
.blocks
;
1075 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1076 size_t size
, int flags
)
1079 struct dentry
*lower_dentry
;
1081 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1082 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1087 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1089 fsstack_copy_attr_all(dentry
->d_inode
, lower_dentry
->d_inode
);
1095 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1096 void *value
, size_t size
)
1100 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1104 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1105 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1107 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1113 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1116 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1121 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1124 struct dentry
*lower_dentry
;
1126 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1127 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1131 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1132 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1133 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1138 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1141 struct dentry
*lower_dentry
;
1143 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1144 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1148 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1149 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1150 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1155 const struct inode_operations ecryptfs_symlink_iops
= {
1156 .readlink
= ecryptfs_readlink
,
1157 .follow_link
= ecryptfs_follow_link
,
1158 .put_link
= ecryptfs_put_link
,
1159 .permission
= ecryptfs_permission
,
1160 .setattr
= ecryptfs_setattr
,
1161 .getattr
= ecryptfs_getattr_link
,
1162 .setxattr
= ecryptfs_setxattr
,
1163 .getxattr
= ecryptfs_getxattr
,
1164 .listxattr
= ecryptfs_listxattr
,
1165 .removexattr
= ecryptfs_removexattr
1168 const struct inode_operations ecryptfs_dir_iops
= {
1169 .create
= ecryptfs_create
,
1170 .lookup
= ecryptfs_lookup
,
1171 .link
= ecryptfs_link
,
1172 .unlink
= ecryptfs_unlink
,
1173 .symlink
= ecryptfs_symlink
,
1174 .mkdir
= ecryptfs_mkdir
,
1175 .rmdir
= ecryptfs_rmdir
,
1176 .mknod
= ecryptfs_mknod
,
1177 .rename
= ecryptfs_rename
,
1178 .permission
= ecryptfs_permission
,
1179 .setattr
= ecryptfs_setattr
,
1180 .setxattr
= ecryptfs_setxattr
,
1181 .getxattr
= ecryptfs_getxattr
,
1182 .listxattr
= ecryptfs_listxattr
,
1183 .removexattr
= ecryptfs_removexattr
1186 const struct inode_operations ecryptfs_main_iops
= {
1187 .permission
= ecryptfs_permission
,
1188 .setattr
= ecryptfs_setattr
,
1189 .getattr
= ecryptfs_getattr
,
1190 .setxattr
= ecryptfs_setxattr
,
1191 .getxattr
= ecryptfs_getxattr
,
1192 .listxattr
= ecryptfs_listxattr
,
1193 .removexattr
= ecryptfs_removexattr