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
;
78 dentry_save
= nd
->path
.dentry
;
79 vfsmount_save
= nd
->path
.mnt
;
80 flags_save
= nd
->flags
;
81 nd
->path
.dentry
= lower_dentry
;
82 nd
->path
.mnt
= lower_mnt
;
83 nd
->flags
&= ~LOOKUP_OPEN
;
85 rc
= vfs_create(lower_dir_inode
, lower_dentry
, mode
, nd
);
87 nd
->path
.dentry
= dentry_save
;
88 nd
->path
.mnt
= vfsmount_save
;
89 nd
->flags
= flags_save
;
96 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
97 * @ecryptfs_dentry: New file's dentry in ecryptfs
98 * @mode: The mode of the new file
99 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
101 * Creates the underlying file and the eCryptfs inode which will link to
102 * it. It will also update the eCryptfs directory inode to mimic the
103 * stat of the lower directory inode.
105 * Returns zero on success; non-zero on error condition
108 ecryptfs_do_create(struct inode
*directory_inode
,
109 struct dentry
*ecryptfs_dentry
, int mode
,
110 struct nameidata
*nd
)
113 struct dentry
*lower_dentry
;
114 struct dentry
*lower_dir_dentry
;
116 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
117 lower_dir_dentry
= lock_parent(lower_dentry
);
118 if (IS_ERR(lower_dir_dentry
)) {
119 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
121 rc
= PTR_ERR(lower_dir_dentry
);
124 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
125 ecryptfs_dentry
, mode
, nd
);
127 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
128 "rc = [%d]\n", __func__
, rc
);
131 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
132 directory_inode
->i_sb
, 0);
134 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
137 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
138 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
140 unlock_dir(lower_dir_dentry
);
147 * @ecryptfs_dentry: the eCryptfs dentry
149 * This is the code which will grow the file to its correct size.
151 static int grow_file(struct dentry
*ecryptfs_dentry
)
153 struct inode
*ecryptfs_inode
= ecryptfs_dentry
->d_inode
;
154 char zero_virt
[] = { 0x00 };
157 rc
= ecryptfs_write(ecryptfs_inode
, zero_virt
, 0, 1);
158 i_size_write(ecryptfs_inode
, 0);
159 rc
= ecryptfs_write_inode_size_to_metadata(ecryptfs_inode
);
160 ecryptfs_inode_to_private(ecryptfs_inode
)->crypt_stat
.flags
|=
166 * ecryptfs_initialize_file
168 * Cause the file to be changed from a basic empty file to an ecryptfs
169 * file with a header and first data page.
171 * Returns zero on success
173 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
175 struct ecryptfs_crypt_stat
*crypt_stat
=
176 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
179 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
180 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
181 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
184 crypt_stat
->flags
|= ECRYPTFS_NEW_FILE
;
185 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
186 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
188 ecryptfs_printk(KERN_ERR
, "Error creating new file "
189 "context; rc = [%d]\n", rc
);
192 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
194 printk(KERN_ERR
"%s: Error attempting to initialize "
195 "the persistent file for the dentry with name "
196 "[%s]; rc = [%d]\n", __func__
,
197 ecryptfs_dentry
->d_name
.name
, rc
);
200 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
202 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
205 rc
= grow_file(ecryptfs_dentry
);
207 printk(KERN_ERR
"Error growing file; rc = [%d]\n", rc
);
214 * @dir: The inode of the directory in which to create the file.
215 * @dentry: The eCryptfs dentry
216 * @mode: The mode of the new file.
219 * Creates a new file.
221 * Returns zero on success; non-zero on error condition
224 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
225 int mode
, struct nameidata
*nd
)
229 /* ecryptfs_do_create() calls ecryptfs_interpose() */
230 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
, nd
);
232 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
233 "lower filesystem\n");
236 /* At this point, a file exists on "disk"; we need to make sure
237 * that this on disk file is prepared to be an ecryptfs file */
238 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
244 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
246 int ecryptfs_lookup_and_interpose_lower(struct dentry
*ecryptfs_dentry
,
247 struct dentry
*lower_dentry
,
248 struct inode
*ecryptfs_dir_inode
)
250 struct dentry
*lower_dir_dentry
;
251 struct vfsmount
*lower_mnt
;
252 struct inode
*lower_inode
;
253 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
254 struct ecryptfs_crypt_stat
*crypt_stat
;
255 char *page_virt
= NULL
;
259 lower_dir_dentry
= lower_dentry
->d_parent
;
260 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(
261 ecryptfs_dentry
->d_parent
));
262 lower_inode
= lower_dentry
->d_inode
;
263 fsstack_copy_attr_atime(ecryptfs_dir_inode
, lower_dir_dentry
->d_inode
);
264 BUG_ON(!lower_dentry
->d_count
);
265 ecryptfs_set_dentry_private(ecryptfs_dentry
,
266 kmem_cache_alloc(ecryptfs_dentry_info_cache
,
268 if (!ecryptfs_dentry_to_private(ecryptfs_dentry
)) {
270 printk(KERN_ERR
"%s: Out of memory whilst attempting "
271 "to allocate ecryptfs_dentry_info struct\n",
275 ecryptfs_set_dentry_lower(ecryptfs_dentry
, lower_dentry
);
276 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry
, lower_mnt
);
277 if (!lower_dentry
->d_inode
) {
278 /* We want to add because we couldn't find in lower */
279 d_add(ecryptfs_dentry
, NULL
);
282 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
283 ecryptfs_dir_inode
->i_sb
,
284 ECRYPTFS_INTERPOSE_FLAG_D_ADD
);
286 printk(KERN_ERR
"%s: Error interposing; rc = [%d]\n",
290 if (S_ISDIR(lower_inode
->i_mode
))
292 if (S_ISLNK(lower_inode
->i_mode
))
294 if (special_file(lower_inode
->i_mode
))
296 /* Released in this function */
297 page_virt
= kmem_cache_zalloc(ecryptfs_header_cache_2
, GFP_USER
);
299 printk(KERN_ERR
"%s: Cannot kmem_cache_zalloc() a page\n",
304 rc
= ecryptfs_init_persistent_file(ecryptfs_dentry
);
306 printk(KERN_ERR
"%s: Error attempting to initialize "
307 "the persistent file for the dentry with name "
308 "[%s]; rc = [%d]\n", __func__
,
309 ecryptfs_dentry
->d_name
.name
, rc
);
312 crypt_stat
= &ecryptfs_inode_to_private(
313 ecryptfs_dentry
->d_inode
)->crypt_stat
;
314 /* TODO: lock for crypt_stat comparison */
315 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
316 ecryptfs_set_default_sizes(crypt_stat
);
317 rc
= ecryptfs_read_and_validate_header_region(page_virt
,
318 ecryptfs_dentry
->d_inode
);
320 memset(page_virt
, 0, PAGE_CACHE_SIZE
);
321 rc
= ecryptfs_read_and_validate_xattr_region(page_virt
,
327 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
329 mount_crypt_stat
= &ecryptfs_superblock_to_private(
330 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
331 if (mount_crypt_stat
->flags
& ECRYPTFS_ENCRYPTED_VIEW_ENABLED
) {
332 if (crypt_stat
->flags
& ECRYPTFS_METADATA_IN_XATTR
)
333 file_size
= (crypt_stat
->metadata_size
334 + i_size_read(lower_dentry
->d_inode
));
336 file_size
= i_size_read(lower_dentry
->d_inode
);
338 file_size
= get_unaligned_be64(page_virt
);
340 i_size_write(ecryptfs_dentry
->d_inode
, (loff_t
)file_size
);
342 kmem_cache_free(ecryptfs_header_cache_2
, page_virt
);
347 d_drop(ecryptfs_dentry
);
354 * @ecryptfs_dir_inode: The eCryptfs directory inode
355 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
356 * @ecryptfs_nd: nameidata; may be NULL
358 * Find a file on disk. If the file does not exist, then we'll add it to the
359 * dentry cache and continue on to read it from the disk.
361 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
362 struct dentry
*ecryptfs_dentry
,
363 struct nameidata
*ecryptfs_nd
)
365 char *encrypted_and_encoded_name
= NULL
;
366 size_t encrypted_and_encoded_name_size
;
367 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
368 struct dentry
*lower_dir_dentry
, *lower_dentry
;
371 if ((ecryptfs_dentry
->d_name
.len
== 1
372 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
373 || (ecryptfs_dentry
->d_name
.len
== 2
374 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
377 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
378 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
379 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
381 ecryptfs_dentry
->d_name
.len
);
382 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
383 if (IS_ERR(lower_dentry
)) {
384 rc
= PTR_ERR(lower_dentry
);
385 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
386 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
387 encrypted_and_encoded_name
);
390 if (lower_dentry
->d_inode
)
391 goto lookup_and_interpose
;
392 mount_crypt_stat
= &ecryptfs_superblock_to_private(
393 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
394 if (!(mount_crypt_stat
395 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
396 goto lookup_and_interpose
;
398 rc
= ecryptfs_encrypt_and_encode_filename(
399 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
400 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
401 ecryptfs_dentry
->d_name
.len
);
403 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
404 "filename; rc = [%d]\n", __func__
, rc
);
407 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
408 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
410 encrypted_and_encoded_name_size
);
411 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
412 if (IS_ERR(lower_dentry
)) {
413 rc
= PTR_ERR(lower_dentry
);
414 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
415 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
416 encrypted_and_encoded_name
);
419 lookup_and_interpose
:
420 rc
= ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry
, lower_dentry
,
424 d_drop(ecryptfs_dentry
);
426 kfree(encrypted_and_encoded_name
);
430 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
431 struct dentry
*new_dentry
)
433 struct dentry
*lower_old_dentry
;
434 struct dentry
*lower_new_dentry
;
435 struct dentry
*lower_dir_dentry
;
439 file_size_save
= i_size_read(old_dentry
->d_inode
);
440 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
441 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
442 dget(lower_old_dentry
);
443 dget(lower_new_dentry
);
444 lower_dir_dentry
= lock_parent(lower_new_dentry
);
445 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
447 if (rc
|| !lower_new_dentry
->d_inode
)
449 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
, 0);
452 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
453 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
454 old_dentry
->d_inode
->i_nlink
=
455 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
456 i_size_write(new_dentry
->d_inode
, file_size_save
);
458 unlock_dir(lower_dir_dentry
);
459 dput(lower_new_dentry
);
460 dput(lower_old_dentry
);
464 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
467 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
468 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
469 struct dentry
*lower_dir_dentry
;
472 lower_dir_dentry
= lock_parent(lower_dentry
);
473 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
475 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
478 fsstack_copy_attr_times(dir
, lower_dir_inode
);
479 dentry
->d_inode
->i_nlink
=
480 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
481 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
484 unlock_dir(lower_dir_dentry
);
489 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
493 struct dentry
*lower_dentry
;
494 struct dentry
*lower_dir_dentry
;
495 char *encoded_symname
;
496 size_t encoded_symlen
;
497 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
499 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
501 lower_dir_dentry
= lock_parent(lower_dentry
);
502 mount_crypt_stat
= &ecryptfs_superblock_to_private(
503 dir
->i_sb
)->mount_crypt_stat
;
504 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
507 mount_crypt_stat
, symname
,
511 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
513 kfree(encoded_symname
);
514 if (rc
|| !lower_dentry
->d_inode
)
516 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
519 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
520 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
522 unlock_dir(lower_dir_dentry
);
524 if (!dentry
->d_inode
)
529 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
532 struct dentry
*lower_dentry
;
533 struct dentry
*lower_dir_dentry
;
535 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
536 lower_dir_dentry
= lock_parent(lower_dentry
);
537 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
538 if (rc
|| !lower_dentry
->d_inode
)
540 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
543 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
544 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
545 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
547 unlock_dir(lower_dir_dentry
);
548 if (!dentry
->d_inode
)
553 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
555 struct dentry
*lower_dentry
;
556 struct dentry
*lower_dir_dentry
;
559 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
561 lower_dir_dentry
= lock_parent(lower_dentry
);
563 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
566 d_delete(lower_dentry
);
567 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
568 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
569 unlock_dir(lower_dir_dentry
);
577 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
580 struct dentry
*lower_dentry
;
581 struct dentry
*lower_dir_dentry
;
583 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
584 lower_dir_dentry
= lock_parent(lower_dentry
);
585 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
586 if (rc
|| !lower_dentry
->d_inode
)
588 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
, 0);
591 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
592 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
594 unlock_dir(lower_dir_dentry
);
595 if (!dentry
->d_inode
)
601 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
602 struct inode
*new_dir
, struct dentry
*new_dentry
)
605 struct dentry
*lower_old_dentry
;
606 struct dentry
*lower_new_dentry
;
607 struct dentry
*lower_old_dir_dentry
;
608 struct dentry
*lower_new_dir_dentry
;
609 struct dentry
*trap
= NULL
;
611 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
612 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
613 dget(lower_old_dentry
);
614 dget(lower_new_dentry
);
615 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
616 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
617 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
618 /* source should not be ancestor of target */
619 if (trap
== lower_old_dentry
) {
623 /* target should not be ancestor of source */
624 if (trap
== lower_new_dentry
) {
628 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
629 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
632 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
633 if (new_dir
!= old_dir
)
634 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
636 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
637 dput(lower_new_dentry
->d_parent
);
638 dput(lower_old_dentry
->d_parent
);
639 dput(lower_new_dentry
);
640 dput(lower_old_dentry
);
644 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
647 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
649 size_t lower_bufsiz
= PATH_MAX
;
653 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
660 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
661 (char __user
*)lower_buf
,
667 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
668 lower_buf
, lower_bufsiz
);
675 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
678 size_t kbufsiz
, copied
;
681 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
684 copied
= min_t(size_t, bufsiz
, kbufsiz
);
685 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
687 fsstack_copy_attr_atime(dentry
->d_inode
,
688 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
693 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
696 int len
= PAGE_SIZE
, rc
;
699 /* Released in ecryptfs_put_link(); only release here on error */
700 buf
= kmalloc(len
, GFP_KERNEL
);
702 buf
= ERR_PTR(-ENOMEM
);
707 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
715 nd_set_link(nd
, buf
);
720 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
722 char *buf
= nd_get_link(nd
);
730 * upper_size_to_lower_size
731 * @crypt_stat: Crypt_stat associated with file
732 * @upper_size: Size of the upper file
734 * Calculate the required size of the lower file based on the
735 * specified size of the upper file. This calculation is based on the
736 * number of headers in the underlying file and the extent size.
738 * Returns Calculated size of the lower file.
741 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
746 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
747 if (upper_size
!= 0) {
750 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
751 if (upper_size
& ~crypt_stat
->extent_mask
)
753 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
760 * @dentry: The ecryptfs layer dentry
761 * @ia: Address of the ecryptfs inode's attributes
762 * @lower_ia: Address of the lower inode's attributes
764 * Function to handle truncations modifying the size of the file. Note
765 * that the file sizes are interpolated. When expanding, we are simply
766 * writing strings of 0's out. When truncating, we truncate the upper
767 * inode and update the lower_ia according to the page index
768 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
769 * the caller must use lower_ia in a call to notify_change() to perform
770 * the truncation of the lower inode.
772 * Returns zero on success; non-zero otherwise
774 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
775 struct iattr
*lower_ia
)
778 struct inode
*inode
= dentry
->d_inode
;
779 struct ecryptfs_crypt_stat
*crypt_stat
;
780 loff_t i_size
= i_size_read(inode
);
781 loff_t lower_size_before_truncate
;
782 loff_t lower_size_after_truncate
;
784 if (unlikely((ia
->ia_size
== i_size
))) {
785 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
788 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
789 /* Switch on growing or shrinking file */
790 if (ia
->ia_size
> i_size
) {
791 char zero
[] = { 0x00 };
793 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
794 /* Write a single 0 at the last position of the file;
795 * this triggers code that will fill in 0's throughout
796 * the intermediate portion of the previous end of the
797 * file and the new and of the file */
798 rc
= ecryptfs_write(inode
, zero
,
799 (ia
->ia_size
- 1), 1);
800 } else { /* ia->ia_size < i_size_read(inode) */
801 /* We're chopping off all the pages down to the page
802 * in which ia->ia_size is located. Fill in the end of
803 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
804 * PAGE_CACHE_SIZE with zeros. */
805 size_t num_zeros
= (PAGE_CACHE_SIZE
806 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
810 * XXX(truncate) this should really happen at the begginning
811 * of ->setattr. But the code is too messy to that as part
812 * of a larger patch. ecryptfs is also totally missing out
813 * on the inode_change_ok check at the beginning of
814 * ->setattr while would include this.
816 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
820 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
821 truncate_setsize(inode
, ia
->ia_size
);
822 lower_ia
->ia_size
= ia
->ia_size
;
823 lower_ia
->ia_valid
|= ATTR_SIZE
;
829 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
834 rc
= ecryptfs_write(inode
, zeros_virt
,
835 ia
->ia_size
, num_zeros
);
838 printk(KERN_ERR
"Error attempting to zero out "
839 "the remainder of the end page on "
840 "reducing truncate; rc = [%d]\n", rc
);
844 truncate_setsize(inode
, ia
->ia_size
);
845 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
847 printk(KERN_ERR
"Problem with "
848 "ecryptfs_write_inode_size_to_metadata; "
852 /* We are reducing the size of the ecryptfs file, and need to
853 * know if we need to reduce the size of the lower file. */
854 lower_size_before_truncate
=
855 upper_size_to_lower_size(crypt_stat
, i_size
);
856 lower_size_after_truncate
=
857 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
858 if (lower_size_after_truncate
< lower_size_before_truncate
) {
859 lower_ia
->ia_size
= lower_size_after_truncate
;
860 lower_ia
->ia_valid
|= ATTR_SIZE
;
862 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
870 * @dentry: The ecryptfs layer dentry
871 * @new_length: The length to expand the file to
873 * Simple function that handles the truncation of an eCryptfs inode and
874 * its corresponding lower inode.
876 * Returns zero on success; non-zero otherwise
878 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
880 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
881 struct iattr lower_ia
= { .ia_valid
= 0 };
884 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
885 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
886 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
888 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
889 rc
= notify_change(lower_dentry
, &lower_ia
);
890 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
896 ecryptfs_permission(struct inode
*inode
, int mask
, unsigned int flags
)
898 if (flags
& IPERM_FLAG_RCU
)
900 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
905 * @dentry: dentry handle to the inode to modify
906 * @ia: Structure with flags of what to change and values
908 * Updates the metadata of an inode. If the update is to the size
909 * i.e. truncation, then ecryptfs_truncate will handle the size modification
910 * of both the ecryptfs inode and the lower inode.
912 * All other metadata changes will be passed right to the lower filesystem,
913 * and we will just update our inode to look like the lower.
915 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
918 struct dentry
*lower_dentry
;
919 struct iattr lower_ia
;
921 struct inode
*lower_inode
;
922 struct ecryptfs_crypt_stat
*crypt_stat
;
924 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
925 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
926 ecryptfs_init_crypt_stat(crypt_stat
);
927 inode
= dentry
->d_inode
;
928 lower_inode
= ecryptfs_inode_to_lower(inode
);
929 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
930 mutex_lock(&crypt_stat
->cs_mutex
);
931 if (S_ISDIR(dentry
->d_inode
->i_mode
))
932 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
933 else if (S_ISREG(dentry
->d_inode
->i_mode
)
934 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
935 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
936 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
938 mount_crypt_stat
= &ecryptfs_superblock_to_private(
939 dentry
->d_sb
)->mount_crypt_stat
;
940 rc
= ecryptfs_read_metadata(dentry
);
942 if (!(mount_crypt_stat
->flags
943 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
945 printk(KERN_WARNING
"Either the lower file "
946 "is not in a valid eCryptfs format, "
947 "or the key could not be retrieved. "
948 "Plaintext passthrough mode is not "
949 "enabled; returning -EIO\n");
950 mutex_unlock(&crypt_stat
->cs_mutex
);
954 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
957 mutex_unlock(&crypt_stat
->cs_mutex
);
958 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
959 if (ia
->ia_valid
& ATTR_FILE
)
960 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
961 if (ia
->ia_valid
& ATTR_SIZE
) {
962 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
968 * mode change is for clearing setuid/setgid bits. Allow lower fs
969 * to interpret this in its own way.
971 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
972 lower_ia
.ia_valid
&= ~ATTR_MODE
;
974 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
975 rc
= notify_change(lower_dentry
, &lower_ia
);
976 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
978 fsstack_copy_attr_all(inode
, lower_inode
);
982 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
985 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
988 mount_crypt_stat
= &ecryptfs_superblock_to_private(
989 dentry
->d_sb
)->mount_crypt_stat
;
990 generic_fillattr(dentry
->d_inode
, stat
);
991 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
995 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
998 stat
->size
= targetsiz
;
1004 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1007 struct kstat lower_stat
;
1010 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1011 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1013 fsstack_copy_attr_all(dentry
->d_inode
,
1014 ecryptfs_inode_to_lower(dentry
->d_inode
));
1015 generic_fillattr(dentry
->d_inode
, stat
);
1016 stat
->blocks
= lower_stat
.blocks
;
1022 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1023 size_t size
, int flags
)
1026 struct dentry
*lower_dentry
;
1028 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1029 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1034 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1040 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1041 void *value
, size_t size
)
1045 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1049 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1050 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1052 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1058 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1061 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1066 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1069 struct dentry
*lower_dentry
;
1071 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1072 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1076 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1077 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1078 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1083 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1086 struct dentry
*lower_dentry
;
1088 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1089 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1093 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1094 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1095 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1100 int ecryptfs_inode_test(struct inode
*inode
, void *candidate_lower_inode
)
1102 if ((ecryptfs_inode_to_lower(inode
)
1103 == (struct inode
*)candidate_lower_inode
))
1109 int ecryptfs_inode_set(struct inode
*inode
, void *lower_inode
)
1111 ecryptfs_init_inode(inode
, (struct inode
*)lower_inode
);
1115 const struct inode_operations ecryptfs_symlink_iops
= {
1116 .readlink
= ecryptfs_readlink
,
1117 .follow_link
= ecryptfs_follow_link
,
1118 .put_link
= ecryptfs_put_link
,
1119 .permission
= ecryptfs_permission
,
1120 .setattr
= ecryptfs_setattr
,
1121 .getattr
= ecryptfs_getattr_link
,
1122 .setxattr
= ecryptfs_setxattr
,
1123 .getxattr
= ecryptfs_getxattr
,
1124 .listxattr
= ecryptfs_listxattr
,
1125 .removexattr
= ecryptfs_removexattr
1128 const struct inode_operations ecryptfs_dir_iops
= {
1129 .create
= ecryptfs_create
,
1130 .lookup
= ecryptfs_lookup
,
1131 .link
= ecryptfs_link
,
1132 .unlink
= ecryptfs_unlink
,
1133 .symlink
= ecryptfs_symlink
,
1134 .mkdir
= ecryptfs_mkdir
,
1135 .rmdir
= ecryptfs_rmdir
,
1136 .mknod
= ecryptfs_mknod
,
1137 .rename
= ecryptfs_rename
,
1138 .permission
= ecryptfs_permission
,
1139 .setattr
= ecryptfs_setattr
,
1140 .setxattr
= ecryptfs_setxattr
,
1141 .getxattr
= ecryptfs_getxattr
,
1142 .listxattr
= ecryptfs_listxattr
,
1143 .removexattr
= ecryptfs_removexattr
1146 const struct inode_operations ecryptfs_main_iops
= {
1147 .permission
= ecryptfs_permission
,
1148 .setattr
= ecryptfs_setattr
,
1149 .getattr
= ecryptfs_getattr
,
1150 .setxattr
= ecryptfs_setxattr
,
1151 .getxattr
= ecryptfs_getxattr
,
1152 .listxattr
= ecryptfs_listxattr
,
1153 .removexattr
= ecryptfs_removexattr