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
);
147 * ecryptfs_create_underlying_file
148 * @lower_dir_inode: inode of the parent in the lower fs of the new file
149 * @dentry: New file's dentry
150 * @mode: The mode of the new file
152 * Creates the file in the lower file system.
154 * Returns zero on success; non-zero on error condition
157 ecryptfs_create_underlying_file(struct inode
*lower_dir_inode
,
158 struct dentry
*dentry
, int mode
)
160 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
161 return vfs_create(lower_dir_inode
, lower_dentry
, mode
, NULL
);
166 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
167 * @ecryptfs_dentry: New file's dentry in ecryptfs
168 * @mode: The mode of the new file
169 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
171 * Creates the underlying file and the eCryptfs inode which will link to
172 * it. It will also update the eCryptfs directory inode to mimic the
173 * stat of the lower directory inode.
175 * Returns zero on success; non-zero on error condition
178 ecryptfs_do_create(struct inode
*directory_inode
,
179 struct dentry
*ecryptfs_dentry
, int mode
)
182 struct dentry
*lower_dentry
;
183 struct dentry
*lower_dir_dentry
;
185 lower_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
);
186 lower_dir_dentry
= lock_parent(lower_dentry
);
187 if (IS_ERR(lower_dir_dentry
)) {
188 ecryptfs_printk(KERN_ERR
, "Error locking directory of "
190 rc
= PTR_ERR(lower_dir_dentry
);
193 rc
= ecryptfs_create_underlying_file(lower_dir_dentry
->d_inode
,
194 ecryptfs_dentry
, mode
);
196 printk(KERN_ERR
"%s: Failure to create dentry in lower fs; "
197 "rc = [%d]\n", __func__
, rc
);
200 rc
= ecryptfs_interpose(lower_dentry
, ecryptfs_dentry
,
201 directory_inode
->i_sb
);
203 ecryptfs_printk(KERN_ERR
, "Failure in ecryptfs_interpose\n");
206 fsstack_copy_attr_times(directory_inode
, lower_dir_dentry
->d_inode
);
207 fsstack_copy_inode_size(directory_inode
, lower_dir_dentry
->d_inode
);
209 unlock_dir(lower_dir_dentry
);
215 * ecryptfs_initialize_file
217 * Cause the file to be changed from a basic empty file to an ecryptfs
218 * file with a header and first data page.
220 * Returns zero on success
222 static int ecryptfs_initialize_file(struct dentry
*ecryptfs_dentry
)
224 struct ecryptfs_crypt_stat
*crypt_stat
=
225 &ecryptfs_inode_to_private(ecryptfs_dentry
->d_inode
)->crypt_stat
;
228 if (S_ISDIR(ecryptfs_dentry
->d_inode
->i_mode
)) {
229 ecryptfs_printk(KERN_DEBUG
, "This is a directory\n");
230 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
233 ecryptfs_printk(KERN_DEBUG
, "Initializing crypto context\n");
234 rc
= ecryptfs_new_file_context(ecryptfs_dentry
);
236 ecryptfs_printk(KERN_ERR
, "Error creating new file "
237 "context; rc = [%d]\n", rc
);
240 rc
= ecryptfs_get_lower_file(ecryptfs_dentry
,
241 ecryptfs_dentry
->d_inode
);
243 printk(KERN_ERR
"%s: Error attempting to initialize "
244 "the lower file for the dentry with name "
245 "[%s]; rc = [%d]\n", __func__
,
246 ecryptfs_dentry
->d_name
.name
, rc
);
249 rc
= ecryptfs_write_metadata(ecryptfs_dentry
);
251 printk(KERN_ERR
"Error writing headers; rc = [%d]\n", rc
);
252 ecryptfs_put_lower_file(ecryptfs_dentry
->d_inode
);
259 * @dir: The inode of the directory in which to create the file.
260 * @dentry: The eCryptfs dentry
261 * @mode: The mode of the new file.
264 * Creates a new file.
266 * Returns zero on success; non-zero on error condition
269 ecryptfs_create(struct inode
*directory_inode
, struct dentry
*ecryptfs_dentry
,
270 int mode
, struct nameidata
*nd
)
274 /* ecryptfs_do_create() calls ecryptfs_interpose() */
275 rc
= ecryptfs_do_create(directory_inode
, ecryptfs_dentry
, mode
);
277 ecryptfs_printk(KERN_WARNING
, "Failed to create file in"
278 "lower filesystem\n");
281 /* At this point, a file exists on "disk"; we need to make sure
282 * that this on disk file is prepared to be an ecryptfs file */
283 rc
= ecryptfs_initialize_file(ecryptfs_dentry
);
288 static int ecryptfs_i_size_read(struct dentry
*dentry
, struct inode
*inode
)
290 struct ecryptfs_crypt_stat
*crypt_stat
;
293 rc
= ecryptfs_get_lower_file(dentry
, inode
);
295 printk(KERN_ERR
"%s: Error attempting to initialize "
296 "the lower file for the dentry with name "
297 "[%s]; rc = [%d]\n", __func__
,
298 dentry
->d_name
.name
, rc
);
302 crypt_stat
= &ecryptfs_inode_to_private(inode
)->crypt_stat
;
303 /* TODO: lock for crypt_stat comparison */
304 if (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
))
305 ecryptfs_set_default_sizes(crypt_stat
);
307 rc
= ecryptfs_read_and_validate_header_region(inode
);
308 ecryptfs_put_lower_file(inode
);
310 rc
= ecryptfs_read_and_validate_xattr_region(dentry
, inode
);
312 crypt_stat
->flags
|= ECRYPTFS_METADATA_IN_XATTR
;
315 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
320 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
322 static int ecryptfs_lookup_interpose(struct dentry
*dentry
,
323 struct dentry
*lower_dentry
,
324 struct inode
*dir_inode
)
326 struct inode
*inode
, *lower_inode
= lower_dentry
->d_inode
;
327 struct ecryptfs_dentry_info
*dentry_info
;
328 struct vfsmount
*lower_mnt
;
331 lower_mnt
= mntget(ecryptfs_dentry_to_lower_mnt(dentry
->d_parent
));
332 fsstack_copy_attr_atime(dir_inode
, lower_dentry
->d_parent
->d_inode
);
333 BUG_ON(!lower_dentry
->d_count
);
335 dentry_info
= kmem_cache_alloc(ecryptfs_dentry_info_cache
, GFP_KERNEL
);
336 ecryptfs_set_dentry_private(dentry
, dentry_info
);
338 printk(KERN_ERR
"%s: Out of memory whilst attempting "
339 "to allocate ecryptfs_dentry_info struct\n",
346 ecryptfs_set_dentry_lower(dentry
, lower_dentry
);
347 ecryptfs_set_dentry_lower_mnt(dentry
, lower_mnt
);
349 if (!lower_dentry
->d_inode
) {
350 /* We want to add because we couldn't find in lower */
354 inode
= __ecryptfs_get_inode(lower_inode
, dir_inode
->i_sb
);
356 printk(KERN_ERR
"%s: Error interposing; rc = [%ld]\n",
357 __func__
, PTR_ERR(inode
));
358 return PTR_ERR(inode
);
360 if (S_ISREG(inode
->i_mode
)) {
361 rc
= ecryptfs_i_size_read(dentry
, inode
);
363 make_bad_inode(inode
);
368 if (inode
->i_state
& I_NEW
)
369 unlock_new_inode(inode
);
370 d_add(dentry
, inode
);
377 * @ecryptfs_dir_inode: The eCryptfs directory inode
378 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
379 * @ecryptfs_nd: nameidata; may be NULL
381 * Find a file on disk. If the file does not exist, then we'll add it to the
382 * dentry cache and continue on to read it from the disk.
384 static struct dentry
*ecryptfs_lookup(struct inode
*ecryptfs_dir_inode
,
385 struct dentry
*ecryptfs_dentry
,
386 struct nameidata
*ecryptfs_nd
)
388 char *encrypted_and_encoded_name
= NULL
;
389 size_t encrypted_and_encoded_name_size
;
390 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
391 struct dentry
*lower_dir_dentry
, *lower_dentry
;
394 if ((ecryptfs_dentry
->d_name
.len
== 1
395 && !strcmp(ecryptfs_dentry
->d_name
.name
, "."))
396 || (ecryptfs_dentry
->d_name
.len
== 2
397 && !strcmp(ecryptfs_dentry
->d_name
.name
, ".."))) {
400 lower_dir_dentry
= ecryptfs_dentry_to_lower(ecryptfs_dentry
->d_parent
);
401 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
402 lower_dentry
= lookup_one_len(ecryptfs_dentry
->d_name
.name
,
404 ecryptfs_dentry
->d_name
.len
);
405 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
406 if (IS_ERR(lower_dentry
)) {
407 rc
= PTR_ERR(lower_dentry
);
408 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
409 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
410 encrypted_and_encoded_name
);
413 if (lower_dentry
->d_inode
)
415 mount_crypt_stat
= &ecryptfs_superblock_to_private(
416 ecryptfs_dentry
->d_sb
)->mount_crypt_stat
;
417 if (!(mount_crypt_stat
418 && (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
)))
421 rc
= ecryptfs_encrypt_and_encode_filename(
422 &encrypted_and_encoded_name
, &encrypted_and_encoded_name_size
,
423 NULL
, mount_crypt_stat
, ecryptfs_dentry
->d_name
.name
,
424 ecryptfs_dentry
->d_name
.len
);
426 printk(KERN_ERR
"%s: Error attempting to encrypt and encode "
427 "filename; rc = [%d]\n", __func__
, rc
);
430 mutex_lock(&lower_dir_dentry
->d_inode
->i_mutex
);
431 lower_dentry
= lookup_one_len(encrypted_and_encoded_name
,
433 encrypted_and_encoded_name_size
);
434 mutex_unlock(&lower_dir_dentry
->d_inode
->i_mutex
);
435 if (IS_ERR(lower_dentry
)) {
436 rc
= PTR_ERR(lower_dentry
);
437 ecryptfs_printk(KERN_DEBUG
, "%s: lookup_one_len() returned "
438 "[%d] on lower_dentry = [%s]\n", __func__
, rc
,
439 encrypted_and_encoded_name
);
443 rc
= ecryptfs_lookup_interpose(ecryptfs_dentry
, lower_dentry
,
447 d_drop(ecryptfs_dentry
);
449 kfree(encrypted_and_encoded_name
);
453 static int ecryptfs_link(struct dentry
*old_dentry
, struct inode
*dir
,
454 struct dentry
*new_dentry
)
456 struct dentry
*lower_old_dentry
;
457 struct dentry
*lower_new_dentry
;
458 struct dentry
*lower_dir_dentry
;
462 file_size_save
= i_size_read(old_dentry
->d_inode
);
463 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
464 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
465 dget(lower_old_dentry
);
466 dget(lower_new_dentry
);
467 lower_dir_dentry
= lock_parent(lower_new_dentry
);
468 rc
= vfs_link(lower_old_dentry
, lower_dir_dentry
->d_inode
,
470 if (rc
|| !lower_new_dentry
->d_inode
)
472 rc
= ecryptfs_interpose(lower_new_dentry
, new_dentry
, dir
->i_sb
);
475 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
476 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
477 old_dentry
->d_inode
->i_nlink
=
478 ecryptfs_inode_to_lower(old_dentry
->d_inode
)->i_nlink
;
479 i_size_write(new_dentry
->d_inode
, file_size_save
);
481 unlock_dir(lower_dir_dentry
);
482 dput(lower_new_dentry
);
483 dput(lower_old_dentry
);
487 static int ecryptfs_unlink(struct inode
*dir
, struct dentry
*dentry
)
490 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
491 struct inode
*lower_dir_inode
= ecryptfs_inode_to_lower(dir
);
492 struct dentry
*lower_dir_dentry
;
495 lower_dir_dentry
= lock_parent(lower_dentry
);
496 rc
= vfs_unlink(lower_dir_inode
, lower_dentry
);
498 printk(KERN_ERR
"Error in vfs_unlink; rc = [%d]\n", rc
);
501 fsstack_copy_attr_times(dir
, lower_dir_inode
);
502 dentry
->d_inode
->i_nlink
=
503 ecryptfs_inode_to_lower(dentry
->d_inode
)->i_nlink
;
504 dentry
->d_inode
->i_ctime
= dir
->i_ctime
;
507 unlock_dir(lower_dir_dentry
);
512 static int ecryptfs_symlink(struct inode
*dir
, struct dentry
*dentry
,
516 struct dentry
*lower_dentry
;
517 struct dentry
*lower_dir_dentry
;
518 char *encoded_symname
;
519 size_t encoded_symlen
;
520 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
= NULL
;
522 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
524 lower_dir_dentry
= lock_parent(lower_dentry
);
525 mount_crypt_stat
= &ecryptfs_superblock_to_private(
526 dir
->i_sb
)->mount_crypt_stat
;
527 rc
= ecryptfs_encrypt_and_encode_filename(&encoded_symname
,
530 mount_crypt_stat
, symname
,
534 rc
= vfs_symlink(lower_dir_dentry
->d_inode
, lower_dentry
,
536 kfree(encoded_symname
);
537 if (rc
|| !lower_dentry
->d_inode
)
539 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
542 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
543 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
545 unlock_dir(lower_dir_dentry
);
547 if (!dentry
->d_inode
)
552 static int ecryptfs_mkdir(struct inode
*dir
, struct dentry
*dentry
, int mode
)
555 struct dentry
*lower_dentry
;
556 struct dentry
*lower_dir_dentry
;
558 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
559 lower_dir_dentry
= lock_parent(lower_dentry
);
560 rc
= vfs_mkdir(lower_dir_dentry
->d_inode
, lower_dentry
, mode
);
561 if (rc
|| !lower_dentry
->d_inode
)
563 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
566 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
567 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
568 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
570 unlock_dir(lower_dir_dentry
);
571 if (!dentry
->d_inode
)
576 static int ecryptfs_rmdir(struct inode
*dir
, struct dentry
*dentry
)
578 struct dentry
*lower_dentry
;
579 struct dentry
*lower_dir_dentry
;
582 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
584 lower_dir_dentry
= lock_parent(lower_dentry
);
586 rc
= vfs_rmdir(lower_dir_dentry
->d_inode
, lower_dentry
);
588 if (!rc
&& dentry
->d_inode
)
589 clear_nlink(dentry
->d_inode
);
590 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
591 dir
->i_nlink
= lower_dir_dentry
->d_inode
->i_nlink
;
592 unlock_dir(lower_dir_dentry
);
600 ecryptfs_mknod(struct inode
*dir
, struct dentry
*dentry
, int mode
, dev_t dev
)
603 struct dentry
*lower_dentry
;
604 struct dentry
*lower_dir_dentry
;
606 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
607 lower_dir_dentry
= lock_parent(lower_dentry
);
608 rc
= vfs_mknod(lower_dir_dentry
->d_inode
, lower_dentry
, mode
, dev
);
609 if (rc
|| !lower_dentry
->d_inode
)
611 rc
= ecryptfs_interpose(lower_dentry
, dentry
, dir
->i_sb
);
614 fsstack_copy_attr_times(dir
, lower_dir_dentry
->d_inode
);
615 fsstack_copy_inode_size(dir
, lower_dir_dentry
->d_inode
);
617 unlock_dir(lower_dir_dentry
);
618 if (!dentry
->d_inode
)
624 ecryptfs_rename(struct inode
*old_dir
, struct dentry
*old_dentry
,
625 struct inode
*new_dir
, struct dentry
*new_dentry
)
628 struct dentry
*lower_old_dentry
;
629 struct dentry
*lower_new_dentry
;
630 struct dentry
*lower_old_dir_dentry
;
631 struct dentry
*lower_new_dir_dentry
;
632 struct dentry
*trap
= NULL
;
634 lower_old_dentry
= ecryptfs_dentry_to_lower(old_dentry
);
635 lower_new_dentry
= ecryptfs_dentry_to_lower(new_dentry
);
636 dget(lower_old_dentry
);
637 dget(lower_new_dentry
);
638 lower_old_dir_dentry
= dget_parent(lower_old_dentry
);
639 lower_new_dir_dentry
= dget_parent(lower_new_dentry
);
640 trap
= lock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
641 /* source should not be ancestor of target */
642 if (trap
== lower_old_dentry
) {
646 /* target should not be ancestor of source */
647 if (trap
== lower_new_dentry
) {
651 rc
= vfs_rename(lower_old_dir_dentry
->d_inode
, lower_old_dentry
,
652 lower_new_dir_dentry
->d_inode
, lower_new_dentry
);
655 fsstack_copy_attr_all(new_dir
, lower_new_dir_dentry
->d_inode
);
656 if (new_dir
!= old_dir
)
657 fsstack_copy_attr_all(old_dir
, lower_old_dir_dentry
->d_inode
);
659 unlock_rename(lower_old_dir_dentry
, lower_new_dir_dentry
);
660 dput(lower_new_dir_dentry
);
661 dput(lower_old_dir_dentry
);
662 dput(lower_new_dentry
);
663 dput(lower_old_dentry
);
667 static int ecryptfs_readlink_lower(struct dentry
*dentry
, char **buf
,
670 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
672 size_t lower_bufsiz
= PATH_MAX
;
676 lower_buf
= kmalloc(lower_bufsiz
, GFP_KERNEL
);
683 rc
= lower_dentry
->d_inode
->i_op
->readlink(lower_dentry
,
684 (char __user
*)lower_buf
,
690 rc
= ecryptfs_decode_and_decrypt_filename(buf
, bufsiz
, dentry
,
691 lower_buf
, lower_bufsiz
);
698 ecryptfs_readlink(struct dentry
*dentry
, char __user
*buf
, int bufsiz
)
701 size_t kbufsiz
, copied
;
704 rc
= ecryptfs_readlink_lower(dentry
, &kbuf
, &kbufsiz
);
707 copied
= min_t(size_t, bufsiz
, kbufsiz
);
708 rc
= copy_to_user(buf
, kbuf
, copied
) ? -EFAULT
: copied
;
710 fsstack_copy_attr_atime(dentry
->d_inode
,
711 ecryptfs_dentry_to_lower(dentry
)->d_inode
);
716 static void *ecryptfs_follow_link(struct dentry
*dentry
, struct nameidata
*nd
)
719 int len
= PAGE_SIZE
, rc
;
722 /* Released in ecryptfs_put_link(); only release here on error */
723 buf
= kmalloc(len
, GFP_KERNEL
);
725 buf
= ERR_PTR(-ENOMEM
);
730 rc
= dentry
->d_inode
->i_op
->readlink(dentry
, (char __user
*)buf
, len
);
738 nd_set_link(nd
, buf
);
743 ecryptfs_put_link(struct dentry
*dentry
, struct nameidata
*nd
, void *ptr
)
745 char *buf
= nd_get_link(nd
);
753 * upper_size_to_lower_size
754 * @crypt_stat: Crypt_stat associated with file
755 * @upper_size: Size of the upper file
757 * Calculate the required size of the lower file based on the
758 * specified size of the upper file. This calculation is based on the
759 * number of headers in the underlying file and the extent size.
761 * Returns Calculated size of the lower file.
764 upper_size_to_lower_size(struct ecryptfs_crypt_stat
*crypt_stat
,
769 lower_size
= ecryptfs_lower_header_size(crypt_stat
);
770 if (upper_size
!= 0) {
773 num_extents
= upper_size
>> crypt_stat
->extent_shift
;
774 if (upper_size
& ~crypt_stat
->extent_mask
)
776 lower_size
+= (num_extents
* crypt_stat
->extent_size
);
783 * @dentry: The ecryptfs layer dentry
784 * @ia: Address of the ecryptfs inode's attributes
785 * @lower_ia: Address of the lower inode's attributes
787 * Function to handle truncations modifying the size of the file. Note
788 * that the file sizes are interpolated. When expanding, we are simply
789 * writing strings of 0's out. When truncating, we truncate the upper
790 * inode and update the lower_ia according to the page index
791 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
792 * the caller must use lower_ia in a call to notify_change() to perform
793 * the truncation of the lower inode.
795 * Returns zero on success; non-zero otherwise
797 static int truncate_upper(struct dentry
*dentry
, struct iattr
*ia
,
798 struct iattr
*lower_ia
)
801 struct inode
*inode
= dentry
->d_inode
;
802 struct ecryptfs_crypt_stat
*crypt_stat
;
803 loff_t i_size
= i_size_read(inode
);
804 loff_t lower_size_before_truncate
;
805 loff_t lower_size_after_truncate
;
807 if (unlikely((ia
->ia_size
== i_size
))) {
808 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
811 rc
= ecryptfs_get_lower_file(dentry
, inode
);
814 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
815 /* Switch on growing or shrinking file */
816 if (ia
->ia_size
> i_size
) {
817 char zero
[] = { 0x00 };
819 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
820 /* Write a single 0 at the last position of the file;
821 * this triggers code that will fill in 0's throughout
822 * the intermediate portion of the previous end of the
823 * file and the new and of the file */
824 rc
= ecryptfs_write(inode
, zero
,
825 (ia
->ia_size
- 1), 1);
826 } else { /* ia->ia_size < i_size_read(inode) */
827 /* We're chopping off all the pages down to the page
828 * in which ia->ia_size is located. Fill in the end of
829 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
830 * PAGE_CACHE_SIZE with zeros. */
831 size_t num_zeros
= (PAGE_CACHE_SIZE
832 - (ia
->ia_size
& ~PAGE_CACHE_MASK
));
836 * XXX(truncate) this should really happen at the begginning
837 * of ->setattr. But the code is too messy to that as part
838 * of a larger patch. ecryptfs is also totally missing out
839 * on the inode_change_ok check at the beginning of
840 * ->setattr while would include this.
842 rc
= inode_newsize_ok(inode
, ia
->ia_size
);
846 if (!(crypt_stat
->flags
& ECRYPTFS_ENCRYPTED
)) {
847 truncate_setsize(inode
, ia
->ia_size
);
848 lower_ia
->ia_size
= ia
->ia_size
;
849 lower_ia
->ia_valid
|= ATTR_SIZE
;
855 zeros_virt
= kzalloc(num_zeros
, GFP_KERNEL
);
860 rc
= ecryptfs_write(inode
, zeros_virt
,
861 ia
->ia_size
, num_zeros
);
864 printk(KERN_ERR
"Error attempting to zero out "
865 "the remainder of the end page on "
866 "reducing truncate; rc = [%d]\n", rc
);
870 truncate_setsize(inode
, ia
->ia_size
);
871 rc
= ecryptfs_write_inode_size_to_metadata(inode
);
873 printk(KERN_ERR
"Problem with "
874 "ecryptfs_write_inode_size_to_metadata; "
878 /* We are reducing the size of the ecryptfs file, and need to
879 * know if we need to reduce the size of the lower file. */
880 lower_size_before_truncate
=
881 upper_size_to_lower_size(crypt_stat
, i_size
);
882 lower_size_after_truncate
=
883 upper_size_to_lower_size(crypt_stat
, ia
->ia_size
);
884 if (lower_size_after_truncate
< lower_size_before_truncate
) {
885 lower_ia
->ia_size
= lower_size_after_truncate
;
886 lower_ia
->ia_valid
|= ATTR_SIZE
;
888 lower_ia
->ia_valid
&= ~ATTR_SIZE
;
891 ecryptfs_put_lower_file(inode
);
897 * @dentry: The ecryptfs layer dentry
898 * @new_length: The length to expand the file to
900 * Simple function that handles the truncation of an eCryptfs inode and
901 * its corresponding lower inode.
903 * Returns zero on success; non-zero otherwise
905 int ecryptfs_truncate(struct dentry
*dentry
, loff_t new_length
)
907 struct iattr ia
= { .ia_valid
= ATTR_SIZE
, .ia_size
= new_length
};
908 struct iattr lower_ia
= { .ia_valid
= 0 };
911 rc
= truncate_upper(dentry
, &ia
, &lower_ia
);
912 if (!rc
&& lower_ia
.ia_valid
& ATTR_SIZE
) {
913 struct dentry
*lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
915 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
916 rc
= notify_change(lower_dentry
, &lower_ia
);
917 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
923 ecryptfs_permission(struct inode
*inode
, int mask
)
925 return inode_permission(ecryptfs_inode_to_lower(inode
), mask
);
930 * @dentry: dentry handle to the inode to modify
931 * @ia: Structure with flags of what to change and values
933 * Updates the metadata of an inode. If the update is to the size
934 * i.e. truncation, then ecryptfs_truncate will handle the size modification
935 * of both the ecryptfs inode and the lower inode.
937 * All other metadata changes will be passed right to the lower filesystem,
938 * and we will just update our inode to look like the lower.
940 static int ecryptfs_setattr(struct dentry
*dentry
, struct iattr
*ia
)
943 struct dentry
*lower_dentry
;
944 struct iattr lower_ia
;
946 struct inode
*lower_inode
;
947 struct ecryptfs_crypt_stat
*crypt_stat
;
949 crypt_stat
= &ecryptfs_inode_to_private(dentry
->d_inode
)->crypt_stat
;
950 if (!(crypt_stat
->flags
& ECRYPTFS_STRUCT_INITIALIZED
))
951 ecryptfs_init_crypt_stat(crypt_stat
);
952 inode
= dentry
->d_inode
;
953 lower_inode
= ecryptfs_inode_to_lower(inode
);
954 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
955 mutex_lock(&crypt_stat
->cs_mutex
);
956 if (S_ISDIR(dentry
->d_inode
->i_mode
))
957 crypt_stat
->flags
&= ~(ECRYPTFS_ENCRYPTED
);
958 else if (S_ISREG(dentry
->d_inode
->i_mode
)
959 && (!(crypt_stat
->flags
& ECRYPTFS_POLICY_APPLIED
)
960 || !(crypt_stat
->flags
& ECRYPTFS_KEY_VALID
))) {
961 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
963 mount_crypt_stat
= &ecryptfs_superblock_to_private(
964 dentry
->d_sb
)->mount_crypt_stat
;
965 rc
= ecryptfs_get_lower_file(dentry
, inode
);
967 mutex_unlock(&crypt_stat
->cs_mutex
);
970 rc
= ecryptfs_read_metadata(dentry
);
971 ecryptfs_put_lower_file(inode
);
973 if (!(mount_crypt_stat
->flags
974 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED
)) {
976 printk(KERN_WARNING
"Either the lower file "
977 "is not in a valid eCryptfs format, "
978 "or the key could not be retrieved. "
979 "Plaintext passthrough mode is not "
980 "enabled; returning -EIO\n");
981 mutex_unlock(&crypt_stat
->cs_mutex
);
985 crypt_stat
->flags
&= ~(ECRYPTFS_I_SIZE_INITIALIZED
986 | ECRYPTFS_ENCRYPTED
);
989 mutex_unlock(&crypt_stat
->cs_mutex
);
990 if (S_ISREG(inode
->i_mode
)) {
991 rc
= filemap_write_and_wait(inode
->i_mapping
);
994 fsstack_copy_attr_all(inode
, lower_inode
);
996 memcpy(&lower_ia
, ia
, sizeof(lower_ia
));
997 if (ia
->ia_valid
& ATTR_FILE
)
998 lower_ia
.ia_file
= ecryptfs_file_to_lower(ia
->ia_file
);
999 if (ia
->ia_valid
& ATTR_SIZE
) {
1000 rc
= truncate_upper(dentry
, ia
, &lower_ia
);
1006 * mode change is for clearing setuid/setgid bits. Allow lower fs
1007 * to interpret this in its own way.
1009 if (lower_ia
.ia_valid
& (ATTR_KILL_SUID
| ATTR_KILL_SGID
))
1010 lower_ia
.ia_valid
&= ~ATTR_MODE
;
1012 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1013 rc
= notify_change(lower_dentry
, &lower_ia
);
1014 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1016 fsstack_copy_attr_all(inode
, lower_inode
);
1020 int ecryptfs_getattr_link(struct vfsmount
*mnt
, struct dentry
*dentry
,
1023 struct ecryptfs_mount_crypt_stat
*mount_crypt_stat
;
1026 mount_crypt_stat
= &ecryptfs_superblock_to_private(
1027 dentry
->d_sb
)->mount_crypt_stat
;
1028 generic_fillattr(dentry
->d_inode
, stat
);
1029 if (mount_crypt_stat
->flags
& ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES
) {
1033 rc
= ecryptfs_readlink_lower(dentry
, &target
, &targetsiz
);
1036 stat
->size
= targetsiz
;
1042 int ecryptfs_getattr(struct vfsmount
*mnt
, struct dentry
*dentry
,
1045 struct kstat lower_stat
;
1048 rc
= vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry
),
1049 ecryptfs_dentry_to_lower(dentry
), &lower_stat
);
1051 fsstack_copy_attr_all(dentry
->d_inode
,
1052 ecryptfs_inode_to_lower(dentry
->d_inode
));
1053 generic_fillattr(dentry
->d_inode
, stat
);
1054 stat
->blocks
= lower_stat
.blocks
;
1060 ecryptfs_setxattr(struct dentry
*dentry
, const char *name
, const void *value
,
1061 size_t size
, int flags
)
1064 struct dentry
*lower_dentry
;
1066 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1067 if (!lower_dentry
->d_inode
->i_op
->setxattr
) {
1072 rc
= vfs_setxattr(lower_dentry
, name
, value
, size
, flags
);
1078 ecryptfs_getxattr_lower(struct dentry
*lower_dentry
, const char *name
,
1079 void *value
, size_t size
)
1083 if (!lower_dentry
->d_inode
->i_op
->getxattr
) {
1087 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1088 rc
= lower_dentry
->d_inode
->i_op
->getxattr(lower_dentry
, name
, value
,
1090 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1096 ecryptfs_getxattr(struct dentry
*dentry
, const char *name
, void *value
,
1099 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry
), name
,
1104 ecryptfs_listxattr(struct dentry
*dentry
, char *list
, size_t size
)
1107 struct dentry
*lower_dentry
;
1109 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1110 if (!lower_dentry
->d_inode
->i_op
->listxattr
) {
1114 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1115 rc
= lower_dentry
->d_inode
->i_op
->listxattr(lower_dentry
, list
, size
);
1116 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1121 static int ecryptfs_removexattr(struct dentry
*dentry
, const char *name
)
1124 struct dentry
*lower_dentry
;
1126 lower_dentry
= ecryptfs_dentry_to_lower(dentry
);
1127 if (!lower_dentry
->d_inode
->i_op
->removexattr
) {
1131 mutex_lock(&lower_dentry
->d_inode
->i_mutex
);
1132 rc
= lower_dentry
->d_inode
->i_op
->removexattr(lower_dentry
, name
);
1133 mutex_unlock(&lower_dentry
->d_inode
->i_mutex
);
1138 const struct inode_operations ecryptfs_symlink_iops
= {
1139 .readlink
= ecryptfs_readlink
,
1140 .follow_link
= ecryptfs_follow_link
,
1141 .put_link
= ecryptfs_put_link
,
1142 .permission
= ecryptfs_permission
,
1143 .setattr
= ecryptfs_setattr
,
1144 .getattr
= ecryptfs_getattr_link
,
1145 .setxattr
= ecryptfs_setxattr
,
1146 .getxattr
= ecryptfs_getxattr
,
1147 .listxattr
= ecryptfs_listxattr
,
1148 .removexattr
= ecryptfs_removexattr
1151 const struct inode_operations ecryptfs_dir_iops
= {
1152 .create
= ecryptfs_create
,
1153 .lookup
= ecryptfs_lookup
,
1154 .link
= ecryptfs_link
,
1155 .unlink
= ecryptfs_unlink
,
1156 .symlink
= ecryptfs_symlink
,
1157 .mkdir
= ecryptfs_mkdir
,
1158 .rmdir
= ecryptfs_rmdir
,
1159 .mknod
= ecryptfs_mknod
,
1160 .rename
= ecryptfs_rename
,
1161 .permission
= ecryptfs_permission
,
1162 .setattr
= ecryptfs_setattr
,
1163 .setxattr
= ecryptfs_setxattr
,
1164 .getxattr
= ecryptfs_getxattr
,
1165 .listxattr
= ecryptfs_listxattr
,
1166 .removexattr
= ecryptfs_removexattr
1169 const struct inode_operations ecryptfs_main_iops
= {
1170 .permission
= ecryptfs_permission
,
1171 .setattr
= ecryptfs_setattr
,
1172 .getattr
= ecryptfs_getattr
,
1173 .setxattr
= ecryptfs_setxattr
,
1174 .getxattr
= ecryptfs_getxattr
,
1175 .listxattr
= ecryptfs_listxattr
,
1176 .removexattr
= ecryptfs_removexattr