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
);
55 * ecryptfs_create_underlying_file
56 * @lower_dir_inode: inode of the parent in the lower fs of the new file
57 * @dentry: New file's dentry
58 * @mode: The mode of the new file
59 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
61 * Creates the file in the lower file system.
63 * Returns zero on success; non-zero on error condition
66 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
67 struct dentry
*dentry
, int mode
,
70 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
71 struct vfsmount
*lower_mnt
= ecryptfs_dentry_to_lower_mnt(dentry
);
72 struct dentry
*dentry_save
;
73 struct vfsmount
*vfsmount_save
;
74 unsigned int flags_save
;
77 dentry_save
= nd
->path
.dentry
;
78 vfsmount_save
= nd
->path
.mnt
;
79 flags_save
= nd
->flags
;
80 nd
->path
.dentry
= lower_dentry
;
81 nd
->path
.mnt
= lower_mnt
;
82 nd
->flags
&= ~LOOKUP_OPEN
;
83 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
84 nd
->path
.dentry
= dentry_save
;
85 nd
->path
.mnt
= vfsmount_save
;
86 nd
->flags
= flags_save
;
92 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
93 * @ecryptfs_dentry: New file's dentry in ecryptfs
94 * @mode: The mode of the new file
95 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
97 * Creates the underlying file and the eCryptfs inode which will link to
98 * it. It will also update the eCryptfs directory inode to mimic the
99 * stat of the lower directory inode.
101 * Returns zero on success; non-zero on error condition
104 ecryptfs_do_create(struct inode
*directory_inode
,
105 struct dentry
*ecryptfs_dentry
, int mode
,
106 struct nameidata
*nd
)
109 struct dentry
*lower_dentry
;
110 struct dentry
*lower_dir_dentry
;
112 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
113 lower_dir_dentry
= lock_parent(lower_dentry
);
114 if (IS_ERR(lower_dir_dentry
)) {
115 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
117 rc
= PTR_ERR(lower_dir_dentry
);
120 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
121 ecryptfs_dentry
, mode
, nd
);
123 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
124 "rc = [%d]\n", __func__
, rc
);
127 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
128 directory_inode
->i_sb
, 0);
130 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
133 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
134 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
136 unlock_dir(lower_dir_dentry
);
143 * @ecryptfs_dentry: the eCryptfs dentry
145 * This is the code which will grow the file to its correct size.
147 static int grow_file(struct dentry
*ecryptfs_dentry
)
149 struct inode
*ecryptfs_inode
= ecryptfs_dentry
->d_inode
;
150 char zero_virt
[] = { 0x00 };
153 rc
= ecryptfs_write(ecryptfs_inode
, zero_virt
, 0, 1);
154 i_size_write(ecryptfs_inode
, 0);
155 rc
= ecryptfs_write_inode_size_to_metadata(ecryptfs_inode
);
156 ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
.flags
|=
162 * ecryptfs_initialize_file
164 * Cause the file to be changed from a basic empty file to an ecryptfs
165 * file with a header and first data page.
167 * Returns zero on success
169 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
171 struct ecryptfs_crypt_stat
*crypt_stat
=
172 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
175 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
176 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
177 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
180 crypt_stat
->flags
|= ECRYPTFS_NEW_FILE
;
181 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
182 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
184 ecryptfs_printk(KERN_ERR
, "Error creating new file "
185 "context; rc = [%d]\n", rc
);
188 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
189 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
191 printk(KERN_ERR
"%s: Error attempting to initialize "
192 "the persistent file for the dentry with name "
193 "[%s]; rc = [%d]\n", __func__
,
194 ecryptfs_dentry
->d_name
.name
, rc
);
198 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
200 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
203 rc
= grow_file(ecryptfs_dentry
);
205 printk(KERN_ERR
"Error growing file; rc = [%d]\n", rc
);
212 * @dir: The inode of the directory in which to create the file.
213 * @dentry: The eCryptfs dentry
214 * @mode: The mode of the new file.
217 * Creates a new file.
219 * Returns zero on success; non-zero on error condition
222 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
223 int mode
, struct nameidata
*nd
)
227 /* ecryptfs_do_create() calls ecryptfs_interpose() */
228 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
230 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
231 "lower filesystem\n");
234 /* At this point, a file exists on "disk"; we need to make sure
235 * that this on disk file is prepared to be an ecryptfs file */
236 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
242 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
244 int ecryptfs_lookup_and_interpose_lower(struct dentry
*ecryptfs_dentry
,
245 struct dentry
*lower_dentry
,
246 struct inode
*ecryptfs_dir_inode
,
247 struct nameidata
*ecryptfs_nd
)
249 struct dentry
*lower_dir_dentry
;
250 struct vfsmount
*lower_mnt
;
251 struct inode
*lower_inode
;
252 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
253 struct ecryptfs_crypt_stat
*crypt_stat
;
254 char *page_virt
= NULL
;
258 lower_dir_dentry
= lower_dentry
->d_parent
;
259 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
260 ecryptfs_dentry
->d_parent
));
261 lower_inode
= lower_dentry
->d_inode
;
262 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
263 BUG_ON(!atomic_read(&lower_dentry
->d_count
));
264 ecryptfs_set_dentry_private(ecryptfs_dentry
,
265 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
267 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
269 printk(KERN_ERR
"%s: Out of memory whilst attempting "
270 "to allocate ecryptfs_dentry_info struct\n",
274 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
275 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
276 if (!lower_dentry
->d_inode
) {
277 /* We want to add because we couldn't find in lower */
278 d_add(ecryptfs_dentry
, NULL
);
281 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
282 ecryptfs_dir_inode
->i_sb
,
283 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
285 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
289 if (S_ISDIR(lower_inode
->i_mode
))
291 if (S_ISLNK(lower_inode
->i_mode
))
293 if (special_file(lower_inode
->i_mode
))
297 /* Released in this function */
298 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
300 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
305 if (!ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->lower_file
) {
306 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
308 printk(KERN_ERR
"%s: Error attempting to initialize "
309 "the persistent file for the dentry with name "
310 "[%s]; rc = [%d]\n", __func__
,
311 ecryptfs_dentry
->d_name
.name
, rc
);
315 crypt_stat
= &ecryptfs_inode_to_private(
316 ecryptfs_dentry
->d_inode
)->crypt_stat
;
317 /* TODO: lock for crypt_stat comparison */
318 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
319 ecryptfs_set_default_sizes(crypt_stat
);
320 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
321 ecryptfs_dentry
->d_inode
);
323 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
324 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
330 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
332 mount_crypt_stat
= &ecryptfs_superblock_to_private(
333 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
334 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
335 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
336 file_size
= (crypt_stat
->metadata_size
337 + i_size_read(lower_dentry
->d_inode
));
339 file_size
= i_size_read(lower_dentry
->d_inode
);
341 file_size
= get_unaligned_be64(page_virt
);
343 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
345 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
350 d_drop(ecryptfs_dentry
);
356 * ecryptfs_new_lower_dentry
357 * @name: The name of the new dentry.
358 * @lower_dir_dentry: Parent directory of the new dentry.
359 * @nd: nameidata from last lookup.
361 * Create a new dentry or get it from lower parent dir.
363 static struct dentry
*
364 ecryptfs_new_lower_dentry(struct qstr
*name
, struct dentry
*lower_dir_dentry
,
365 struct nameidata
*nd
)
367 struct dentry
*new_dentry
;
369 struct inode
*lower_dir_inode
;
371 lower_dir_inode
= lower_dir_dentry
->d_inode
;
373 tmp
= d_alloc(lower_dir_dentry
, name
);
375 return ERR_PTR(-ENOMEM
);
377 mutex_lock(&lower_dir_inode
->i_mutex
);
378 new_dentry
= lower_dir_inode
->i_op
->lookup(lower_dir_inode
, tmp
, nd
);
379 mutex_unlock(&lower_dir_inode
->i_mutex
);
391 * ecryptfs_lookup_one_lower
392 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
393 * @lower_dir_dentry: lower parent directory
394 * @name: lower file name
396 * Get the lower dentry from vfs. If lower dentry does not exist yet,
399 static struct dentry
*
400 ecryptfs_lookup_one_lower(struct dentry
*ecryptfs_dentry
,
401 struct dentry
*lower_dir_dentry
, struct qstr
*name
)
404 struct vfsmount
*lower_mnt
;
407 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
408 ecryptfs_dentry
->d_parent
));
409 err
= vfs_path_lookup(lower_dir_dentry
, lower_mnt
, name
->name
, 0, &nd
);
413 /* we dont need the mount */
415 return nd
.path
.dentry
;
420 /* create a new lower dentry */
421 return ecryptfs_new_lower_dentry(name
, lower_dir_dentry
, &nd
);
426 * @ecryptfs_dir_inode: The eCryptfs directory inode
427 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
428 * @ecryptfs_nd: nameidata; may be NULL
430 * Find a file on disk. If the file does not exist, then we'll add it to the
431 * dentry cache and continue on to read it from the disk.
433 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
434 struct dentry
*ecryptfs_dentry
,
435 struct nameidata
*ecryptfs_nd
)
437 char *encrypted_and_encoded_name
= NULL
;
438 size_t encrypted_and_encoded_name_size
;
439 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
440 struct dentry
*lower_dir_dentry
, *lower_dentry
;
441 struct qstr lower_name
;
444 ecryptfs_dentry
->d_op
= &ecryptfs_dops
;
445 if ((ecryptfs_dentry
->d_name
.len
== 1
446 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
447 || (ecryptfs_dentry
->d_name
.len
== 2
448 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
451 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
452 lower_name
.name
= ecryptfs_dentry
->d_name
.name
;
453 lower_name
.len
= ecryptfs_dentry
->d_name
.len
;
454 lower_name
.hash
= ecryptfs_dentry
->d_name
.hash
;
455 if (lower_dir_dentry
->d_op
&& lower_dir_dentry
->d_op
->d_hash
) {
456 rc
= lower_dir_dentry
->d_op
->d_hash(lower_dir_dentry
,
461 lower_dentry
= ecryptfs_lookup_one_lower(ecryptfs_dentry
,
462 lower_dir_dentry
, &lower_name
);
463 if (IS_ERR(lower_dentry
)) {
464 rc
= PTR_ERR(lower_dentry
);
465 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_lower() returned "
466 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
467 encrypted_and_encoded_name
);
470 if (lower_dentry
->d_inode
)
471 goto lookup_and_interpose
;
472 mount_crypt_stat
= &ecryptfs_superblock_to_private(
473 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
474 if (!(mount_crypt_stat
475 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
476 goto lookup_and_interpose
;
478 rc
= ecryptfs_encrypt_and_encode_filename(
479 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
480 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
481 ecryptfs_dentry
->d_name
.len
);
483 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
484 "filename; rc = [%d]\n", __func__
, rc
);
487 lower_name
.name
= encrypted_and_encoded_name
;
488 lower_name
.len
= encrypted_and_encoded_name_size
;
489 lower_name
.hash
= full_name_hash(lower_name
.name
, lower_name
.len
);
490 if (lower_dir_dentry
->d_op
&& lower_dir_dentry
->d_op
->d_hash
) {
491 rc
= lower_dir_dentry
->d_op
->d_hash(lower_dir_dentry
,
496 lower_dentry
= ecryptfs_lookup_one_lower(ecryptfs_dentry
,
497 lower_dir_dentry
, &lower_name
);
498 if (IS_ERR(lower_dentry
)) {
499 rc
= PTR_ERR(lower_dentry
);
500 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_lower() returned "
501 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
502 encrypted_and_encoded_name
);
505 lookup_and_interpose
:
506 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
511 d_drop(ecryptfs_dentry
);
513 kfree(encrypted_and_encoded_name
);
517 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
518 struct dentry
*new_dentry
)
520 struct dentry
*lower_old_dentry
;
521 struct dentry
*lower_new_dentry
;
522 struct dentry
*lower_dir_dentry
;
526 file_size_save
= i_size_read(old_dentry
->d_inode
);
527 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
528 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
529 dget(lower_old_dentry
);
530 dget(lower_new_dentry
);
531 lower_dir_dentry
= lock_parent(lower_new_dentry
);
532 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
534 if (rc
|| !lower_new_dentry
->d_inode
)
536 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
539 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
540 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
541 old_dentry
->d_inode
->i_nlink
=
542 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
543 i_size_write(new_dentry
->d_inode
, file_size_save
);
545 unlock_dir(lower_dir_dentry
);
546 dput(lower_new_dentry
);
547 dput(lower_old_dentry
);
551 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
554 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
555 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
556 struct dentry
*lower_dir_dentry
;
559 lower_dir_dentry
= lock_parent(lower_dentry
);
560 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
562 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
565 fsstack_copy_attr_times(dir
, lower_dir_inode
);
566 dentry
->d_inode
->i_nlink
=
567 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
568 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
571 unlock_dir(lower_dir_dentry
);
576 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
580 struct dentry
*lower_dentry
;
581 struct dentry
*lower_dir_dentry
;
582 char *encoded_symname
;
583 size_t encoded_symlen
;
584 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
586 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
588 lower_dir_dentry
= lock_parent(lower_dentry
);
589 mount_crypt_stat
= &ecryptfs_superblock_to_private(
590 dir
->i_sb
)->mount_crypt_stat
;
591 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
594 mount_crypt_stat
, symname
,
598 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
600 kfree(encoded_symname
);
601 if (rc
|| !lower_dentry
->d_inode
)
603 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
606 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
607 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
609 unlock_dir(lower_dir_dentry
);
611 if (!dentry
->d_inode
)
616 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
619 struct dentry
*lower_dentry
;
620 struct dentry
*lower_dir_dentry
;
622 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
623 lower_dir_dentry
= lock_parent(lower_dentry
);
624 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
625 if (rc
|| !lower_dentry
->d_inode
)
627 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
630 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
631 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
632 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
634 unlock_dir(lower_dir_dentry
);
635 if (!dentry
->d_inode
)
640 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
642 struct dentry
*lower_dentry
;
643 struct dentry
*lower_dir_dentry
;
646 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
648 lower_dir_dentry
= lock_parent(lower_dentry
);
650 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
653 d_delete(lower_dentry
);
654 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
655 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
656 unlock_dir(lower_dir_dentry
);
664 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
667 struct dentry
*lower_dentry
;
668 struct dentry
*lower_dir_dentry
;
670 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
671 lower_dir_dentry
= lock_parent(lower_dentry
);
672 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
673 if (rc
|| !lower_dentry
->d_inode
)
675 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
678 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
679 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
681 unlock_dir(lower_dir_dentry
);
682 if (!dentry
->d_inode
)
688 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
689 struct inode
*new_dir
, struct dentry
*new_dentry
)
692 struct dentry
*lower_old_dentry
;
693 struct dentry
*lower_new_dentry
;
694 struct dentry
*lower_old_dir_dentry
;
695 struct dentry
*lower_new_dir_dentry
;
696 struct dentry
*trap
= NULL
;
698 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
699 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
700 dget(lower_old_dentry
);
701 dget(lower_new_dentry
);
702 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
703 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
704 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
705 /* source should not be ancestor of target */
706 if (trap
== lower_old_dentry
) {
710 /* target should not be ancestor of source */
711 if (trap
== lower_new_dentry
) {
715 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
716 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
719 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
720 if (new_dir
!= old_dir
)
721 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
723 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
724 dput(lower_new_dentry
->d_parent
);
725 dput(lower_old_dentry
->d_parent
);
726 dput(lower_new_dentry
);
727 dput(lower_old_dentry
);
731 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
734 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
736 size_t lower_bufsiz
= PATH_MAX
;
740 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
747 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
748 (char __user
*)lower_buf
,
754 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
755 lower_buf
, lower_bufsiz
);
762 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
765 size_t kbufsiz
, copied
;
768 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
771 copied
= min_t(size_t, bufsiz
, kbufsiz
);
772 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
774 fsstack_copy_attr_atime(dentry
->d_inode
,
775 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
780 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
783 int len
= PAGE_SIZE
, rc
;
786 /* Released in ecryptfs_put_link(); only release here on error */
787 buf
= kmalloc(len
, GFP_KERNEL
);
789 buf
= ERR_PTR(-ENOMEM
);
794 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
802 nd_set_link(nd
, buf
);
807 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
809 char *buf
= nd_get_link(nd
);
817 * upper_size_to_lower_size
818 * @crypt_stat: Crypt_stat associated with file
819 * @upper_size: Size of the upper file
821 * Calculate the required size of the lower file based on the
822 * specified size of the upper file. This calculation is based on the
823 * number of headers in the underlying file and the extent size.
825 * Returns Calculated size of the lower file.
828 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
833 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
834 if (upper_size
!= 0) {
837 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
838 if (upper_size
& ~crypt_stat
->extent_mask
)
840 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
847 * @dentry: The ecryptfs layer dentry
848 * @ia: Address of the ecryptfs inode's attributes
849 * @lower_ia: Address of the lower inode's attributes
851 * Function to handle truncations modifying the size of the file. Note
852 * that the file sizes are interpolated. When expanding, we are simply
853 * writing strings of 0's out. When truncating, we truncate the upper
854 * inode and update the lower_ia according to the page index
855 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
856 * the caller must use lower_ia in a call to notify_change() to perform
857 * the truncation of the lower inode.
859 * Returns zero on success; non-zero otherwise
861 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
862 struct iattr
*lower_ia
)
865 struct inode
*inode
= dentry
->d_inode
;
866 struct ecryptfs_crypt_stat
*crypt_stat
;
867 loff_t i_size
= i_size_read(inode
);
868 loff_t lower_size_before_truncate
;
869 loff_t lower_size_after_truncate
;
871 if (unlikely((ia
->ia_size
== i_size
))) {
872 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
875 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
876 /* Switch on growing or shrinking file */
877 if (ia
->ia_size
> i_size
) {
878 char zero
[] = { 0x00 };
880 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
881 /* Write a single 0 at the last position of the file;
882 * this triggers code that will fill in 0's throughout
883 * the intermediate portion of the previous end of the
884 * file and the new and of the file */
885 rc
= ecryptfs_write(inode
, zero
,
886 (ia
->ia_size
- 1), 1);
887 } else { /* ia->ia_size < i_size_read(inode) */
888 /* We're chopping off all the pages down to the page
889 * in which ia->ia_size is located. Fill in the end of
890 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
891 * PAGE_CACHE_SIZE with zeros. */
892 size_t num_zeros
= (PAGE_CACHE_SIZE
893 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
897 * XXX(truncate) this should really happen at the begginning
898 * of ->setattr. But the code is too messy to that as part
899 * of a larger patch. ecryptfs is also totally missing out
900 * on the inode_change_ok check at the beginning of
901 * ->setattr while would include this.
903 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
907 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
908 truncate_setsize(inode
, ia
->ia_size
);
909 lower_ia
->ia_size
= ia
->ia_size
;
910 lower_ia
->ia_valid
|= ATTR_SIZE
;
916 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
921 rc
= ecryptfs_write(inode
, zeros_virt
,
922 ia
->ia_size
, num_zeros
);
925 printk(KERN_ERR
"Error attempting to zero out "
926 "the remainder of the end page on "
927 "reducing truncate; rc = [%d]\n", rc
);
931 truncate_setsize(inode
, ia
->ia_size
);
932 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
934 printk(KERN_ERR
"Problem with "
935 "ecryptfs_write_inode_size_to_metadata; "
939 /* We are reducing the size of the ecryptfs file, and need to
940 * know if we need to reduce the size of the lower file. */
941 lower_size_before_truncate
=
942 upper_size_to_lower_size(crypt_stat
, i_size
);
943 lower_size_after_truncate
=
944 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
945 if (lower_size_after_truncate
< lower_size_before_truncate
) {
946 lower_ia
->ia_size
= lower_size_after_truncate
;
947 lower_ia
->ia_valid
|= ATTR_SIZE
;
949 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
957 * @dentry: The ecryptfs layer dentry
958 * @new_length: The length to expand the file to
960 * Simple function that handles the truncation of an eCryptfs inode and
961 * its corresponding lower inode.
963 * Returns zero on success; non-zero otherwise
965 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
967 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
968 struct iattr lower_ia
= { .ia_valid
= 0 };
971 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
972 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
973 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
975 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
976 rc
= notify_change(lower_dentry
, &lower_ia
);
977 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
983 ecryptfs_permission(struct inode
*inode
, int mask
)
985 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
990 * @dentry: dentry handle to the inode to modify
991 * @ia: Structure with flags of what to change and values
993 * Updates the metadata of an inode. If the update is to the size
994 * i.e. truncation, then ecryptfs_truncate will handle the size modification
995 * of both the ecryptfs inode and the lower inode.
997 * All other metadata changes will be passed right to the lower filesystem,
998 * and we will just update our inode to look like the lower.
1000 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
1003 struct dentry
*lower_dentry
;
1004 struct iattr lower_ia
;
1005 struct inode
*inode
;
1006 struct inode
*lower_inode
;
1007 struct ecryptfs_crypt_stat
*crypt_stat
;
1009 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
1010 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
1011 ecryptfs_init_crypt_stat(crypt_stat
);
1012 inode
= dentry
->d_inode
;
1013 lower_inode
= ecryptfs_inode_to_lower(inode
);
1014 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1015 mutex_lock(&crypt_stat
->cs_mutex
);
1016 if (S_ISDIR(dentry
->d_inode
->i_mode
))
1017 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
1018 else if (S_ISREG(dentry
->d_inode
->i_mode
)
1019 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
1020 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
1021 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1023 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1024 dentry
->d_sb
)->mount_crypt_stat
;
1025 rc
= ecryptfs_read_metadata(dentry
);
1027 if (!(mount_crypt_stat
->flags
1028 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
1030 printk(KERN_WARNING
"Either the lower file "
1031 "is not in a valid eCryptfs format, "
1032 "or the key could not be retrieved. "
1033 "Plaintext passthrough mode is not "
1034 "enabled; returning -EIO\n");
1035 mutex_unlock(&crypt_stat
->cs_mutex
);
1039 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
1042 mutex_unlock(&crypt_stat
->cs_mutex
);
1043 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
1044 if (ia
->ia_valid
& ATTR_FILE
)
1045 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
1046 if (ia
->ia_valid
& ATTR_SIZE
) {
1047 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1053 * mode change is for clearing setuid/setgid bits. Allow lower fs
1054 * to interpret this in its own way.
1056 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1057 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1059 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1060 rc
= notify_change(lower_dentry
, &lower_ia
);
1061 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1063 fsstack_copy_attr_all(inode
, lower_inode
);
1067 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1070 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1073 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1074 dentry
->d_sb
)->mount_crypt_stat
;
1075 generic_fillattr(dentry
->d_inode
, stat
);
1076 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1080 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1083 stat
->size
= targetsiz
;
1089 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1092 struct kstat lower_stat
;
1095 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1096 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1098 fsstack_copy_attr_all(dentry
->d_inode
,
1099 ecryptfs_inode_to_lower(dentry
->d_inode
));
1100 generic_fillattr(dentry
->d_inode
, stat
);
1101 stat
->blocks
= lower_stat
.blocks
;
1107 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1108 size_t size
, int flags
)
1111 struct dentry
*lower_dentry
;
1113 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1114 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1119 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1125 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1126 void *value
, size_t size
)
1130 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1134 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1135 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1137 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1143 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1146 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1151 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1154 struct dentry
*lower_dentry
;
1156 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1157 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1161 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1162 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1163 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1168 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1171 struct dentry
*lower_dentry
;
1173 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1174 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1178 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1179 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1180 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1185 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1187 if ((ecryptfs_inode_to_lower(inode
)
1188 == (struct inode
*)candidate_lower_inode
))
1194 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1196 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1200 const struct inode_operations ecryptfs_symlink_iops
= {
1201 .readlink
= ecryptfs_readlink
,
1202 .follow_link
= ecryptfs_follow_link
,
1203 .put_link
= ecryptfs_put_link
,
1204 .permission
= ecryptfs_permission
,
1205 .setattr
= ecryptfs_setattr
,
1206 .getattr
= ecryptfs_getattr_link
,
1207 .setxattr
= ecryptfs_setxattr
,
1208 .getxattr
= ecryptfs_getxattr
,
1209 .listxattr
= ecryptfs_listxattr
,
1210 .removexattr
= ecryptfs_removexattr
1213 const struct inode_operations ecryptfs_dir_iops
= {
1214 .create
= ecryptfs_create
,
1215 .lookup
= ecryptfs_lookup
,
1216 .link
= ecryptfs_link
,
1217 .unlink
= ecryptfs_unlink
,
1218 .symlink
= ecryptfs_symlink
,
1219 .mkdir
= ecryptfs_mkdir
,
1220 .rmdir
= ecryptfs_rmdir
,
1221 .mknod
= ecryptfs_mknod
,
1222 .rename
= ecryptfs_rename
,
1223 .permission
= ecryptfs_permission
,
1224 .setattr
= ecryptfs_setattr
,
1225 .setxattr
= ecryptfs_setxattr
,
1226 .getxattr
= ecryptfs_getxattr
,
1227 .listxattr
= ecryptfs_listxattr
,
1228 .removexattr
= ecryptfs_removexattr
1231 const struct inode_operations ecryptfs_main_iops
= {
1232 .permission
= ecryptfs_permission
,
1233 .setattr
= ecryptfs_setattr
,
1234 .getattr
= ecryptfs_getattr
,
1235 .setxattr
= ecryptfs_setxattr
,
1236 .getxattr
= ecryptfs_getxattr
,
1237 .listxattr
= ecryptfs_listxattr
,
1238 .removexattr
= ecryptfs_removexattr