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1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
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>
9 *
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.
14 *
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.
19 *
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
23 * 02111-1307, USA.
24 */
25
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/fs_stack.h>
33#include <linux/slab.h>
34#include <linux/xattr.h>
35#include <asm/unaligned.h>
36#include "ecryptfs_kernel.h"
37
38static struct dentry *lock_parent(struct dentry *dentry)
39{
40 struct dentry *dir;
41
42 dir = dget_parent(dentry);
43 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
44 return dir;
45}
46
47static void unlock_dir(struct dentry *dir)
48{
49 inode_unlock(d_inode(dir));
50 dput(dir);
51}
52
53static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
54{
55 return ecryptfs_inode_to_lower(inode) == lower_inode;
56}
57
58static int ecryptfs_inode_set(struct inode *inode, void *opaque)
59{
60 struct inode *lower_inode = opaque;
61
62 ecryptfs_set_inode_lower(inode, lower_inode);
63 fsstack_copy_attr_all(inode, lower_inode);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode, lower_inode);
66 inode->i_ino = lower_inode->i_ino;
67 inode->i_version++;
68 inode->i_mapping->a_ops = &ecryptfs_aops;
69
70 if (S_ISLNK(inode->i_mode))
71 inode->i_op = &ecryptfs_symlink_iops;
72 else if (S_ISDIR(inode->i_mode))
73 inode->i_op = &ecryptfs_dir_iops;
74 else
75 inode->i_op = &ecryptfs_main_iops;
76
77 if (S_ISDIR(inode->i_mode))
78 inode->i_fop = &ecryptfs_dir_fops;
79 else if (special_file(inode->i_mode))
80 init_special_inode(inode, inode->i_mode, inode->i_rdev);
81 else
82 inode->i_fop = &ecryptfs_main_fops;
83
84 return 0;
85}
86
87static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
88 struct super_block *sb)
89{
90 struct inode *inode;
91
92 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
93 return ERR_PTR(-EXDEV);
94 if (!igrab(lower_inode))
95 return ERR_PTR(-ESTALE);
96 inode = iget5_locked(sb, (unsigned long)lower_inode,
97 ecryptfs_inode_test, ecryptfs_inode_set,
98 lower_inode);
99 if (!inode) {
100 iput(lower_inode);
101 return ERR_PTR(-EACCES);
102 }
103 if (!(inode->i_state & I_NEW))
104 iput(lower_inode);
105
106 return inode;
107}
108
109struct inode *ecryptfs_get_inode(struct inode *lower_inode,
110 struct super_block *sb)
111{
112 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
113
114 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
115 unlock_new_inode(inode);
116
117 return inode;
118}
119
120/**
121 * ecryptfs_interpose
122 * @lower_dentry: Existing dentry in the lower filesystem
123 * @dentry: ecryptfs' dentry
124 * @sb: ecryptfs's super_block
125 *
126 * Interposes upper and lower dentries.
127 *
128 * Returns zero on success; non-zero otherwise
129 */
130static int ecryptfs_interpose(struct dentry *lower_dentry,
131 struct dentry *dentry, struct super_block *sb)
132{
133 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
134
135 if (IS_ERR(inode))
136 return PTR_ERR(inode);
137 d_instantiate(dentry, inode);
138
139 return 0;
140}
141
142static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
143 struct inode *inode)
144{
145 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
146 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
147 struct dentry *lower_dir_dentry;
148 int rc;
149
150 dget(lower_dentry);
151 lower_dir_dentry = lock_parent(lower_dentry);
152 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
153 if (rc) {
154 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
155 goto out_unlock;
156 }
157 fsstack_copy_attr_times(dir, lower_dir_inode);
158 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
159 inode->i_ctime = dir->i_ctime;
160 d_drop(dentry);
161out_unlock:
162 unlock_dir(lower_dir_dentry);
163 dput(lower_dentry);
164 return rc;
165}
166
167/**
168 * ecryptfs_do_create
169 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
170 * @ecryptfs_dentry: New file's dentry in ecryptfs
171 * @mode: The mode of the new file
172 *
173 * Creates the underlying file and the eCryptfs inode which will link to
174 * it. It will also update the eCryptfs directory inode to mimic the
175 * stat of the lower directory inode.
176 *
177 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
178 */
179static struct inode *
180ecryptfs_do_create(struct inode *directory_inode,
181 struct dentry *ecryptfs_dentry, umode_t mode)
182{
183 int rc;
184 struct dentry *lower_dentry;
185 struct dentry *lower_dir_dentry;
186 struct inode *inode;
187
188 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
189 lower_dir_dentry = lock_parent(lower_dentry);
190 rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
191 if (rc) {
192 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
193 "rc = [%d]\n", __func__, rc);
194 inode = ERR_PTR(rc);
195 goto out_lock;
196 }
197 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
198 directory_inode->i_sb);
199 if (IS_ERR(inode)) {
200 vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
201 goto out_lock;
202 }
203 fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
204 fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
205out_lock:
206 unlock_dir(lower_dir_dentry);
207 return inode;
208}
209
210/**
211 * ecryptfs_initialize_file
212 *
213 * Cause the file to be changed from a basic empty file to an ecryptfs
214 * file with a header and first data page.
215 *
216 * Returns zero on success
217 */
218int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
219 struct inode *ecryptfs_inode)
220{
221 struct ecryptfs_crypt_stat *crypt_stat =
222 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
223 int rc = 0;
224
225 if (S_ISDIR(ecryptfs_inode->i_mode)) {
226 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
227 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
228 goto out;
229 }
230 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
231 rc = ecryptfs_new_file_context(ecryptfs_inode);
232 if (rc) {
233 ecryptfs_printk(KERN_ERR, "Error creating new file "
234 "context; rc = [%d]\n", rc);
235 goto out;
236 }
237 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
238 if (rc) {
239 printk(KERN_ERR "%s: Error attempting to initialize "
240 "the lower file for the dentry with name "
241 "[%pd]; rc = [%d]\n", __func__,
242 ecryptfs_dentry, rc);
243 goto out;
244 }
245 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
246 if (rc)
247 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
248 ecryptfs_put_lower_file(ecryptfs_inode);
249out:
250 return rc;
251}
252
253/**
254 * ecryptfs_create
255 * @dir: The inode of the directory in which to create the file.
256 * @dentry: The eCryptfs dentry
257 * @mode: The mode of the new file.
258 *
259 * Creates a new file.
260 *
261 * Returns zero on success; non-zero on error condition
262 */
263static int
264ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
265 umode_t mode, bool excl)
266{
267 struct inode *ecryptfs_inode;
268 int rc;
269
270 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
271 mode);
272 if (IS_ERR(ecryptfs_inode)) {
273 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
274 "lower filesystem\n");
275 rc = PTR_ERR(ecryptfs_inode);
276 goto out;
277 }
278 /* At this point, a file exists on "disk"; we need to make sure
279 * that this on disk file is prepared to be an ecryptfs file */
280 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
281 if (rc) {
282 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
283 ecryptfs_inode);
284 iget_failed(ecryptfs_inode);
285 goto out;
286 }
287 unlock_new_inode(ecryptfs_inode);
288 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
289out:
290 return rc;
291}
292
293static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
294{
295 struct ecryptfs_crypt_stat *crypt_stat;
296 int rc;
297
298 rc = ecryptfs_get_lower_file(dentry, inode);
299 if (rc) {
300 printk(KERN_ERR "%s: Error attempting to initialize "
301 "the lower file for the dentry with name "
302 "[%pd]; rc = [%d]\n", __func__,
303 dentry, rc);
304 return rc;
305 }
306
307 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
308 /* TODO: lock for crypt_stat comparison */
309 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
310 ecryptfs_set_default_sizes(crypt_stat);
311
312 rc = ecryptfs_read_and_validate_header_region(inode);
313 ecryptfs_put_lower_file(inode);
314 if (rc) {
315 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
316 if (!rc)
317 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
318 }
319
320 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
321 return 0;
322}
323
324/**
325 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
326 */
327static int ecryptfs_lookup_interpose(struct dentry *dentry,
328 struct dentry *lower_dentry,
329 struct inode *dir_inode)
330{
331 struct inode *inode, *lower_inode = d_inode(lower_dentry);
332 struct ecryptfs_dentry_info *dentry_info;
333 struct vfsmount *lower_mnt;
334 int rc = 0;
335
336 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
337 if (!dentry_info) {
338 printk(KERN_ERR "%s: Out of memory whilst attempting "
339 "to allocate ecryptfs_dentry_info struct\n",
340 __func__);
341 dput(lower_dentry);
342 return -ENOMEM;
343 }
344
345 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
346 fsstack_copy_attr_atime(dir_inode, d_inode(lower_dentry->d_parent));
347 BUG_ON(!d_count(lower_dentry));
348
349 ecryptfs_set_dentry_private(dentry, dentry_info);
350 dentry_info->lower_path.mnt = lower_mnt;
351 dentry_info->lower_path.dentry = lower_dentry;
352
353 if (d_really_is_negative(lower_dentry)) {
354 /* We want to add because we couldn't find in lower */
355 d_add(dentry, NULL);
356 return 0;
357 }
358 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
359 if (IS_ERR(inode)) {
360 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
361 __func__, PTR_ERR(inode));
362 return PTR_ERR(inode);
363 }
364 if (S_ISREG(inode->i_mode)) {
365 rc = ecryptfs_i_size_read(dentry, inode);
366 if (rc) {
367 make_bad_inode(inode);
368 return rc;
369 }
370 }
371
372 if (inode->i_state & I_NEW)
373 unlock_new_inode(inode);
374 d_add(dentry, inode);
375
376 return rc;
377}
378
379/**
380 * ecryptfs_lookup
381 * @ecryptfs_dir_inode: The eCryptfs directory inode
382 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
383 * @flags: lookup flags
384 *
385 * Find a file on disk. If the file does not exist, then we'll add it to the
386 * dentry cache and continue on to read it from the disk.
387 */
388static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
389 struct dentry *ecryptfs_dentry,
390 unsigned int flags)
391{
392 char *encrypted_and_encoded_name = NULL;
393 size_t encrypted_and_encoded_name_size;
394 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
395 struct dentry *lower_dir_dentry, *lower_dentry;
396 int rc = 0;
397
398 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
399 lower_dentry = lookup_one_len_unlocked(ecryptfs_dentry->d_name.name,
400 lower_dir_dentry,
401 ecryptfs_dentry->d_name.len);
402 if (IS_ERR(lower_dentry)) {
403 rc = PTR_ERR(lower_dentry);
404 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
405 "[%d] on lower_dentry = [%pd]\n", __func__, rc,
406 ecryptfs_dentry);
407 goto out;
408 }
409 if (d_really_is_positive(lower_dentry))
410 goto interpose;
411 mount_crypt_stat = &ecryptfs_superblock_to_private(
412 ecryptfs_dentry->d_sb)->mount_crypt_stat;
413 if (!(mount_crypt_stat
414 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
415 goto interpose;
416 dput(lower_dentry);
417 rc = ecryptfs_encrypt_and_encode_filename(
418 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
419 mount_crypt_stat, ecryptfs_dentry->d_name.name,
420 ecryptfs_dentry->d_name.len);
421 if (rc) {
422 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
423 "filename; rc = [%d]\n", __func__, rc);
424 goto out;
425 }
426 lower_dentry = lookup_one_len_unlocked(encrypted_and_encoded_name,
427 lower_dir_dentry,
428 encrypted_and_encoded_name_size);
429 if (IS_ERR(lower_dentry)) {
430 rc = PTR_ERR(lower_dentry);
431 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
432 "[%d] on lower_dentry = [%s]\n", __func__, rc,
433 encrypted_and_encoded_name);
434 goto out;
435 }
436interpose:
437 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
438 ecryptfs_dir_inode);
439out:
440 kfree(encrypted_and_encoded_name);
441 return ERR_PTR(rc);
442}
443
444static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
445 struct dentry *new_dentry)
446{
447 struct dentry *lower_old_dentry;
448 struct dentry *lower_new_dentry;
449 struct dentry *lower_dir_dentry;
450 u64 file_size_save;
451 int rc;
452
453 file_size_save = i_size_read(d_inode(old_dentry));
454 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
455 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
456 dget(lower_old_dentry);
457 dget(lower_new_dentry);
458 lower_dir_dentry = lock_parent(lower_new_dentry);
459 rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
460 lower_new_dentry, NULL);
461 if (rc || d_really_is_negative(lower_new_dentry))
462 goto out_lock;
463 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
464 if (rc)
465 goto out_lock;
466 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
467 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
468 set_nlink(d_inode(old_dentry),
469 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
470 i_size_write(d_inode(new_dentry), file_size_save);
471out_lock:
472 unlock_dir(lower_dir_dentry);
473 dput(lower_new_dentry);
474 dput(lower_old_dentry);
475 return rc;
476}
477
478static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
479{
480 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
481}
482
483static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
484 const char *symname)
485{
486 int rc;
487 struct dentry *lower_dentry;
488 struct dentry *lower_dir_dentry;
489 char *encoded_symname;
490 size_t encoded_symlen;
491 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
492
493 lower_dentry = ecryptfs_dentry_to_lower(dentry);
494 dget(lower_dentry);
495 lower_dir_dentry = lock_parent(lower_dentry);
496 mount_crypt_stat = &ecryptfs_superblock_to_private(
497 dir->i_sb)->mount_crypt_stat;
498 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
499 &encoded_symlen,
500 mount_crypt_stat, symname,
501 strlen(symname));
502 if (rc)
503 goto out_lock;
504 rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
505 encoded_symname);
506 kfree(encoded_symname);
507 if (rc || d_really_is_negative(lower_dentry))
508 goto out_lock;
509 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
510 if (rc)
511 goto out_lock;
512 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
513 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
514out_lock:
515 unlock_dir(lower_dir_dentry);
516 dput(lower_dentry);
517 if (d_really_is_negative(dentry))
518 d_drop(dentry);
519 return rc;
520}
521
522static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
523{
524 int rc;
525 struct dentry *lower_dentry;
526 struct dentry *lower_dir_dentry;
527
528 lower_dentry = ecryptfs_dentry_to_lower(dentry);
529 lower_dir_dentry = lock_parent(lower_dentry);
530 rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
531 if (rc || d_really_is_negative(lower_dentry))
532 goto out;
533 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
534 if (rc)
535 goto out;
536 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
537 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
538 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
539out:
540 unlock_dir(lower_dir_dentry);
541 if (d_really_is_negative(dentry))
542 d_drop(dentry);
543 return rc;
544}
545
546static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
547{
548 struct dentry *lower_dentry;
549 struct dentry *lower_dir_dentry;
550 int rc;
551
552 lower_dentry = ecryptfs_dentry_to_lower(dentry);
553 dget(dentry);
554 lower_dir_dentry = lock_parent(lower_dentry);
555 dget(lower_dentry);
556 rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
557 dput(lower_dentry);
558 if (!rc && d_really_is_positive(dentry))
559 clear_nlink(d_inode(dentry));
560 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
561 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
562 unlock_dir(lower_dir_dentry);
563 if (!rc)
564 d_drop(dentry);
565 dput(dentry);
566 return rc;
567}
568
569static int
570ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
571{
572 int rc;
573 struct dentry *lower_dentry;
574 struct dentry *lower_dir_dentry;
575
576 lower_dentry = ecryptfs_dentry_to_lower(dentry);
577 lower_dir_dentry = lock_parent(lower_dentry);
578 rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
579 if (rc || d_really_is_negative(lower_dentry))
580 goto out;
581 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
582 if (rc)
583 goto out;
584 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
585 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
586out:
587 unlock_dir(lower_dir_dentry);
588 if (d_really_is_negative(dentry))
589 d_drop(dentry);
590 return rc;
591}
592
593static int
594ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
595 struct inode *new_dir, struct dentry *new_dentry)
596{
597 int rc;
598 struct dentry *lower_old_dentry;
599 struct dentry *lower_new_dentry;
600 struct dentry *lower_old_dir_dentry;
601 struct dentry *lower_new_dir_dentry;
602 struct dentry *trap = NULL;
603 struct inode *target_inode;
604
605 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
606 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
607 dget(lower_old_dentry);
608 dget(lower_new_dentry);
609 lower_old_dir_dentry = dget_parent(lower_old_dentry);
610 lower_new_dir_dentry = dget_parent(lower_new_dentry);
611 target_inode = d_inode(new_dentry);
612 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
613 /* source should not be ancestor of target */
614 if (trap == lower_old_dentry) {
615 rc = -EINVAL;
616 goto out_lock;
617 }
618 /* target should not be ancestor of source */
619 if (trap == lower_new_dentry) {
620 rc = -ENOTEMPTY;
621 goto out_lock;
622 }
623 rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
624 d_inode(lower_new_dir_dentry), lower_new_dentry,
625 NULL, 0);
626 if (rc)
627 goto out_lock;
628 if (target_inode)
629 fsstack_copy_attr_all(target_inode,
630 ecryptfs_inode_to_lower(target_inode));
631 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
632 if (new_dir != old_dir)
633 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
634out_lock:
635 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
636 dput(lower_new_dir_dentry);
637 dput(lower_old_dir_dentry);
638 dput(lower_new_dentry);
639 dput(lower_old_dentry);
640 return rc;
641}
642
643static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
644{
645 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
646 char *lower_buf;
647 char *buf;
648 mm_segment_t old_fs;
649 int rc;
650
651 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
652 if (!lower_buf)
653 return ERR_PTR(-ENOMEM);
654 old_fs = get_fs();
655 set_fs(get_ds());
656 rc = d_inode(lower_dentry)->i_op->readlink(lower_dentry,
657 (char __user *)lower_buf,
658 PATH_MAX);
659 set_fs(old_fs);
660 if (rc < 0)
661 goto out;
662 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
663 lower_buf, rc);
664out:
665 kfree(lower_buf);
666 return rc ? ERR_PTR(rc) : buf;
667}
668
669static const char *ecryptfs_get_link(struct dentry *dentry,
670 struct inode *inode,
671 struct delayed_call *done)
672{
673 size_t len;
674 char *buf;
675
676 if (!dentry)
677 return ERR_PTR(-ECHILD);
678
679 buf = ecryptfs_readlink_lower(dentry, &len);
680 if (IS_ERR(buf))
681 return buf;
682 fsstack_copy_attr_atime(d_inode(dentry),
683 d_inode(ecryptfs_dentry_to_lower(dentry)));
684 buf[len] = '\0';
685 set_delayed_call(done, kfree_link, buf);
686 return buf;
687}
688
689/**
690 * upper_size_to_lower_size
691 * @crypt_stat: Crypt_stat associated with file
692 * @upper_size: Size of the upper file
693 *
694 * Calculate the required size of the lower file based on the
695 * specified size of the upper file. This calculation is based on the
696 * number of headers in the underlying file and the extent size.
697 *
698 * Returns Calculated size of the lower file.
699 */
700static loff_t
701upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
702 loff_t upper_size)
703{
704 loff_t lower_size;
705
706 lower_size = ecryptfs_lower_header_size(crypt_stat);
707 if (upper_size != 0) {
708 loff_t num_extents;
709
710 num_extents = upper_size >> crypt_stat->extent_shift;
711 if (upper_size & ~crypt_stat->extent_mask)
712 num_extents++;
713 lower_size += (num_extents * crypt_stat->extent_size);
714 }
715 return lower_size;
716}
717
718/**
719 * truncate_upper
720 * @dentry: The ecryptfs layer dentry
721 * @ia: Address of the ecryptfs inode's attributes
722 * @lower_ia: Address of the lower inode's attributes
723 *
724 * Function to handle truncations modifying the size of the file. Note
725 * that the file sizes are interpolated. When expanding, we are simply
726 * writing strings of 0's out. When truncating, we truncate the upper
727 * inode and update the lower_ia according to the page index
728 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
729 * the caller must use lower_ia in a call to notify_change() to perform
730 * the truncation of the lower inode.
731 *
732 * Returns zero on success; non-zero otherwise
733 */
734static int truncate_upper(struct dentry *dentry, struct iattr *ia,
735 struct iattr *lower_ia)
736{
737 int rc = 0;
738 struct inode *inode = d_inode(dentry);
739 struct ecryptfs_crypt_stat *crypt_stat;
740 loff_t i_size = i_size_read(inode);
741 loff_t lower_size_before_truncate;
742 loff_t lower_size_after_truncate;
743
744 if (unlikely((ia->ia_size == i_size))) {
745 lower_ia->ia_valid &= ~ATTR_SIZE;
746 return 0;
747 }
748 rc = ecryptfs_get_lower_file(dentry, inode);
749 if (rc)
750 return rc;
751 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
752 /* Switch on growing or shrinking file */
753 if (ia->ia_size > i_size) {
754 char zero[] = { 0x00 };
755
756 lower_ia->ia_valid &= ~ATTR_SIZE;
757 /* Write a single 0 at the last position of the file;
758 * this triggers code that will fill in 0's throughout
759 * the intermediate portion of the previous end of the
760 * file and the new and of the file */
761 rc = ecryptfs_write(inode, zero,
762 (ia->ia_size - 1), 1);
763 } else { /* ia->ia_size < i_size_read(inode) */
764 /* We're chopping off all the pages down to the page
765 * in which ia->ia_size is located. Fill in the end of
766 * that page from (ia->ia_size & ~PAGE_MASK) to
767 * PAGE_SIZE with zeros. */
768 size_t num_zeros = (PAGE_SIZE
769 - (ia->ia_size & ~PAGE_MASK));
770
771 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
772 truncate_setsize(inode, ia->ia_size);
773 lower_ia->ia_size = ia->ia_size;
774 lower_ia->ia_valid |= ATTR_SIZE;
775 goto out;
776 }
777 if (num_zeros) {
778 char *zeros_virt;
779
780 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
781 if (!zeros_virt) {
782 rc = -ENOMEM;
783 goto out;
784 }
785 rc = ecryptfs_write(inode, zeros_virt,
786 ia->ia_size, num_zeros);
787 kfree(zeros_virt);
788 if (rc) {
789 printk(KERN_ERR "Error attempting to zero out "
790 "the remainder of the end page on "
791 "reducing truncate; rc = [%d]\n", rc);
792 goto out;
793 }
794 }
795 truncate_setsize(inode, ia->ia_size);
796 rc = ecryptfs_write_inode_size_to_metadata(inode);
797 if (rc) {
798 printk(KERN_ERR "Problem with "
799 "ecryptfs_write_inode_size_to_metadata; "
800 "rc = [%d]\n", rc);
801 goto out;
802 }
803 /* We are reducing the size of the ecryptfs file, and need to
804 * know if we need to reduce the size of the lower file. */
805 lower_size_before_truncate =
806 upper_size_to_lower_size(crypt_stat, i_size);
807 lower_size_after_truncate =
808 upper_size_to_lower_size(crypt_stat, ia->ia_size);
809 if (lower_size_after_truncate < lower_size_before_truncate) {
810 lower_ia->ia_size = lower_size_after_truncate;
811 lower_ia->ia_valid |= ATTR_SIZE;
812 } else
813 lower_ia->ia_valid &= ~ATTR_SIZE;
814 }
815out:
816 ecryptfs_put_lower_file(inode);
817 return rc;
818}
819
820static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
821{
822 struct ecryptfs_crypt_stat *crypt_stat;
823 loff_t lower_oldsize, lower_newsize;
824
825 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
826 lower_oldsize = upper_size_to_lower_size(crypt_stat,
827 i_size_read(inode));
828 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
829 if (lower_newsize > lower_oldsize) {
830 /*
831 * The eCryptfs inode and the new *lower* size are mixed here
832 * because we may not have the lower i_mutex held and/or it may
833 * not be appropriate to call inode_newsize_ok() with inodes
834 * from other filesystems.
835 */
836 return inode_newsize_ok(inode, lower_newsize);
837 }
838
839 return 0;
840}
841
842/**
843 * ecryptfs_truncate
844 * @dentry: The ecryptfs layer dentry
845 * @new_length: The length to expand the file to
846 *
847 * Simple function that handles the truncation of an eCryptfs inode and
848 * its corresponding lower inode.
849 *
850 * Returns zero on success; non-zero otherwise
851 */
852int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
853{
854 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
855 struct iattr lower_ia = { .ia_valid = 0 };
856 int rc;
857
858 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
859 if (rc)
860 return rc;
861
862 rc = truncate_upper(dentry, &ia, &lower_ia);
863 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
864 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
865
866 inode_lock(d_inode(lower_dentry));
867 rc = notify_change(lower_dentry, &lower_ia, NULL);
868 inode_unlock(d_inode(lower_dentry));
869 }
870 return rc;
871}
872
873static int
874ecryptfs_permission(struct inode *inode, int mask)
875{
876 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
877}
878
879/**
880 * ecryptfs_setattr
881 * @dentry: dentry handle to the inode to modify
882 * @ia: Structure with flags of what to change and values
883 *
884 * Updates the metadata of an inode. If the update is to the size
885 * i.e. truncation, then ecryptfs_truncate will handle the size modification
886 * of both the ecryptfs inode and the lower inode.
887 *
888 * All other metadata changes will be passed right to the lower filesystem,
889 * and we will just update our inode to look like the lower.
890 */
891static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
892{
893 int rc = 0;
894 struct dentry *lower_dentry;
895 struct iattr lower_ia;
896 struct inode *inode;
897 struct inode *lower_inode;
898 struct ecryptfs_crypt_stat *crypt_stat;
899
900 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
901 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
902 ecryptfs_init_crypt_stat(crypt_stat);
903 inode = d_inode(dentry);
904 lower_inode = ecryptfs_inode_to_lower(inode);
905 lower_dentry = ecryptfs_dentry_to_lower(dentry);
906 mutex_lock(&crypt_stat->cs_mutex);
907 if (d_is_dir(dentry))
908 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
909 else if (d_is_reg(dentry)
910 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
911 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
912 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
913
914 mount_crypt_stat = &ecryptfs_superblock_to_private(
915 dentry->d_sb)->mount_crypt_stat;
916 rc = ecryptfs_get_lower_file(dentry, inode);
917 if (rc) {
918 mutex_unlock(&crypt_stat->cs_mutex);
919 goto out;
920 }
921 rc = ecryptfs_read_metadata(dentry);
922 ecryptfs_put_lower_file(inode);
923 if (rc) {
924 if (!(mount_crypt_stat->flags
925 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
926 rc = -EIO;
927 printk(KERN_WARNING "Either the lower file "
928 "is not in a valid eCryptfs format, "
929 "or the key could not be retrieved. "
930 "Plaintext passthrough mode is not "
931 "enabled; returning -EIO\n");
932 mutex_unlock(&crypt_stat->cs_mutex);
933 goto out;
934 }
935 rc = 0;
936 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
937 | ECRYPTFS_ENCRYPTED);
938 }
939 }
940 mutex_unlock(&crypt_stat->cs_mutex);
941
942 rc = inode_change_ok(inode, ia);
943 if (rc)
944 goto out;
945 if (ia->ia_valid & ATTR_SIZE) {
946 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
947 if (rc)
948 goto out;
949 }
950
951 memcpy(&lower_ia, ia, sizeof(lower_ia));
952 if (ia->ia_valid & ATTR_FILE)
953 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
954 if (ia->ia_valid & ATTR_SIZE) {
955 rc = truncate_upper(dentry, ia, &lower_ia);
956 if (rc < 0)
957 goto out;
958 }
959
960 /*
961 * mode change is for clearing setuid/setgid bits. Allow lower fs
962 * to interpret this in its own way.
963 */
964 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
965 lower_ia.ia_valid &= ~ATTR_MODE;
966
967 inode_lock(d_inode(lower_dentry));
968 rc = notify_change(lower_dentry, &lower_ia, NULL);
969 inode_unlock(d_inode(lower_dentry));
970out:
971 fsstack_copy_attr_all(inode, lower_inode);
972 return rc;
973}
974
975static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
976 struct kstat *stat)
977{
978 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
979 int rc = 0;
980
981 mount_crypt_stat = &ecryptfs_superblock_to_private(
982 dentry->d_sb)->mount_crypt_stat;
983 generic_fillattr(d_inode(dentry), stat);
984 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
985 char *target;
986 size_t targetsiz;
987
988 target = ecryptfs_readlink_lower(dentry, &targetsiz);
989 if (!IS_ERR(target)) {
990 kfree(target);
991 stat->size = targetsiz;
992 } else {
993 rc = PTR_ERR(target);
994 }
995 }
996 return rc;
997}
998
999static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1000 struct kstat *stat)
1001{
1002 struct kstat lower_stat;
1003 int rc;
1004
1005 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
1006 if (!rc) {
1007 fsstack_copy_attr_all(d_inode(dentry),
1008 ecryptfs_inode_to_lower(d_inode(dentry)));
1009 generic_fillattr(d_inode(dentry), stat);
1010 stat->blocks = lower_stat.blocks;
1011 }
1012 return rc;
1013}
1014
1015int
1016ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1017 size_t size, int flags)
1018{
1019 int rc = 0;
1020 struct dentry *lower_dentry;
1021
1022 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1023 if (!d_inode(lower_dentry)->i_op->setxattr) {
1024 rc = -EOPNOTSUPP;
1025 goto out;
1026 }
1027
1028 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1029 if (!rc && d_really_is_positive(dentry))
1030 fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
1031out:
1032 return rc;
1033}
1034
1035ssize_t
1036ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1037 void *value, size_t size)
1038{
1039 int rc = 0;
1040
1041 if (!d_inode(lower_dentry)->i_op->getxattr) {
1042 rc = -EOPNOTSUPP;
1043 goto out;
1044 }
1045 inode_lock(d_inode(lower_dentry));
1046 rc = d_inode(lower_dentry)->i_op->getxattr(lower_dentry, name, value,
1047 size);
1048 inode_unlock(d_inode(lower_dentry));
1049out:
1050 return rc;
1051}
1052
1053static ssize_t
1054ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1055 size_t size)
1056{
1057 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1058 value, size);
1059}
1060
1061static ssize_t
1062ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1063{
1064 int rc = 0;
1065 struct dentry *lower_dentry;
1066
1067 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1068 if (!d_inode(lower_dentry)->i_op->listxattr) {
1069 rc = -EOPNOTSUPP;
1070 goto out;
1071 }
1072 inode_lock(d_inode(lower_dentry));
1073 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1074 inode_unlock(d_inode(lower_dentry));
1075out:
1076 return rc;
1077}
1078
1079static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1080{
1081 int rc = 0;
1082 struct dentry *lower_dentry;
1083
1084 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1085 if (!d_inode(lower_dentry)->i_op->removexattr) {
1086 rc = -EOPNOTSUPP;
1087 goto out;
1088 }
1089 inode_lock(d_inode(lower_dentry));
1090 rc = d_inode(lower_dentry)->i_op->removexattr(lower_dentry, name);
1091 inode_unlock(d_inode(lower_dentry));
1092out:
1093 return rc;
1094}
1095
1096const struct inode_operations ecryptfs_symlink_iops = {
1097 .readlink = generic_readlink,
1098 .get_link = ecryptfs_get_link,
1099 .permission = ecryptfs_permission,
1100 .setattr = ecryptfs_setattr,
1101 .getattr = ecryptfs_getattr_link,
1102 .setxattr = ecryptfs_setxattr,
1103 .getxattr = ecryptfs_getxattr,
1104 .listxattr = ecryptfs_listxattr,
1105 .removexattr = ecryptfs_removexattr
1106};
1107
1108const struct inode_operations ecryptfs_dir_iops = {
1109 .create = ecryptfs_create,
1110 .lookup = ecryptfs_lookup,
1111 .link = ecryptfs_link,
1112 .unlink = ecryptfs_unlink,
1113 .symlink = ecryptfs_symlink,
1114 .mkdir = ecryptfs_mkdir,
1115 .rmdir = ecryptfs_rmdir,
1116 .mknod = ecryptfs_mknod,
1117 .rename = ecryptfs_rename,
1118 .permission = ecryptfs_permission,
1119 .setattr = ecryptfs_setattr,
1120 .setxattr = ecryptfs_setxattr,
1121 .getxattr = ecryptfs_getxattr,
1122 .listxattr = ecryptfs_listxattr,
1123 .removexattr = ecryptfs_removexattr
1124};
1125
1126const struct inode_operations ecryptfs_main_iops = {
1127 .permission = ecryptfs_permission,
1128 .setattr = ecryptfs_setattr,
1129 .getattr = ecryptfs_getattr,
1130 .setxattr = ecryptfs_setxattr,
1131 .getxattr = ecryptfs_getxattr,
1132 .listxattr = ecryptfs_listxattr,
1133 .removexattr = ecryptfs_removexattr
1134};
1/**
2 * eCryptfs: Linux filesystem encryption layer
3 *
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>
9 *
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.
14 *
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.
19 *
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
23 * 02111-1307, USA.
24 */
25
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/fs_stack.h>
33#include <linux/slab.h>
34#include <linux/xattr.h>
35#include <asm/unaligned.h>
36#include "ecryptfs_kernel.h"
37
38static struct dentry *lock_parent(struct dentry *dentry)
39{
40 struct dentry *dir;
41
42 dir = dget_parent(dentry);
43 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
44 return dir;
45}
46
47static void unlock_dir(struct dentry *dir)
48{
49 inode_unlock(d_inode(dir));
50 dput(dir);
51}
52
53static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
54{
55 return ecryptfs_inode_to_lower(inode) == lower_inode;
56}
57
58static int ecryptfs_inode_set(struct inode *inode, void *opaque)
59{
60 struct inode *lower_inode = opaque;
61
62 ecryptfs_set_inode_lower(inode, lower_inode);
63 fsstack_copy_attr_all(inode, lower_inode);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode, lower_inode);
66 inode->i_ino = lower_inode->i_ino;
67 inode->i_mapping->a_ops = &ecryptfs_aops;
68
69 if (S_ISLNK(inode->i_mode))
70 inode->i_op = &ecryptfs_symlink_iops;
71 else if (S_ISDIR(inode->i_mode))
72 inode->i_op = &ecryptfs_dir_iops;
73 else
74 inode->i_op = &ecryptfs_main_iops;
75
76 if (S_ISDIR(inode->i_mode))
77 inode->i_fop = &ecryptfs_dir_fops;
78 else if (special_file(inode->i_mode))
79 init_special_inode(inode, inode->i_mode, inode->i_rdev);
80 else
81 inode->i_fop = &ecryptfs_main_fops;
82
83 return 0;
84}
85
86static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
87 struct super_block *sb)
88{
89 struct inode *inode;
90
91 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
92 return ERR_PTR(-EXDEV);
93 if (!igrab(lower_inode))
94 return ERR_PTR(-ESTALE);
95 inode = iget5_locked(sb, (unsigned long)lower_inode,
96 ecryptfs_inode_test, ecryptfs_inode_set,
97 lower_inode);
98 if (!inode) {
99 iput(lower_inode);
100 return ERR_PTR(-EACCES);
101 }
102 if (!(inode->i_state & I_NEW))
103 iput(lower_inode);
104
105 return inode;
106}
107
108struct inode *ecryptfs_get_inode(struct inode *lower_inode,
109 struct super_block *sb)
110{
111 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
112
113 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
114 unlock_new_inode(inode);
115
116 return inode;
117}
118
119/**
120 * ecryptfs_interpose
121 * @lower_dentry: Existing dentry in the lower filesystem
122 * @dentry: ecryptfs' dentry
123 * @sb: ecryptfs's super_block
124 *
125 * Interposes upper and lower dentries.
126 *
127 * Returns zero on success; non-zero otherwise
128 */
129static int ecryptfs_interpose(struct dentry *lower_dentry,
130 struct dentry *dentry, struct super_block *sb)
131{
132 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
133
134 if (IS_ERR(inode))
135 return PTR_ERR(inode);
136 d_instantiate(dentry, inode);
137
138 return 0;
139}
140
141static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
142 struct inode *inode)
143{
144 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
145 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
146 struct dentry *lower_dir_dentry;
147 int rc;
148
149 dget(lower_dentry);
150 lower_dir_dentry = lock_parent(lower_dentry);
151 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
152 if (rc) {
153 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
154 goto out_unlock;
155 }
156 fsstack_copy_attr_times(dir, lower_dir_inode);
157 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
158 inode->i_ctime = dir->i_ctime;
159 d_drop(dentry);
160out_unlock:
161 unlock_dir(lower_dir_dentry);
162 dput(lower_dentry);
163 return rc;
164}
165
166/**
167 * ecryptfs_do_create
168 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
169 * @ecryptfs_dentry: New file's dentry in ecryptfs
170 * @mode: The mode of the new file
171 *
172 * Creates the underlying file and the eCryptfs inode which will link to
173 * it. It will also update the eCryptfs directory inode to mimic the
174 * stat of the lower directory inode.
175 *
176 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
177 */
178static struct inode *
179ecryptfs_do_create(struct inode *directory_inode,
180 struct dentry *ecryptfs_dentry, umode_t mode)
181{
182 int rc;
183 struct dentry *lower_dentry;
184 struct dentry *lower_dir_dentry;
185 struct inode *inode;
186
187 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
188 lower_dir_dentry = lock_parent(lower_dentry);
189 rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
190 if (rc) {
191 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
192 "rc = [%d]\n", __func__, rc);
193 inode = ERR_PTR(rc);
194 goto out_lock;
195 }
196 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
197 directory_inode->i_sb);
198 if (IS_ERR(inode)) {
199 vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
200 goto out_lock;
201 }
202 fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
203 fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
204out_lock:
205 unlock_dir(lower_dir_dentry);
206 return inode;
207}
208
209/**
210 * ecryptfs_initialize_file
211 *
212 * Cause the file to be changed from a basic empty file to an ecryptfs
213 * file with a header and first data page.
214 *
215 * Returns zero on success
216 */
217int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
218 struct inode *ecryptfs_inode)
219{
220 struct ecryptfs_crypt_stat *crypt_stat =
221 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
222 int rc = 0;
223
224 if (S_ISDIR(ecryptfs_inode->i_mode)) {
225 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
226 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
227 goto out;
228 }
229 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
230 rc = ecryptfs_new_file_context(ecryptfs_inode);
231 if (rc) {
232 ecryptfs_printk(KERN_ERR, "Error creating new file "
233 "context; rc = [%d]\n", rc);
234 goto out;
235 }
236 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
237 if (rc) {
238 printk(KERN_ERR "%s: Error attempting to initialize "
239 "the lower file for the dentry with name "
240 "[%pd]; rc = [%d]\n", __func__,
241 ecryptfs_dentry, rc);
242 goto out;
243 }
244 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
245 if (rc)
246 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
247 ecryptfs_put_lower_file(ecryptfs_inode);
248out:
249 return rc;
250}
251
252/**
253 * ecryptfs_create
254 * @dir: The inode of the directory in which to create the file.
255 * @dentry: The eCryptfs dentry
256 * @mode: The mode of the new file.
257 *
258 * Creates a new file.
259 *
260 * Returns zero on success; non-zero on error condition
261 */
262static int
263ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
264 umode_t mode, bool excl)
265{
266 struct inode *ecryptfs_inode;
267 int rc;
268
269 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
270 mode);
271 if (IS_ERR(ecryptfs_inode)) {
272 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
273 "lower filesystem\n");
274 rc = PTR_ERR(ecryptfs_inode);
275 goto out;
276 }
277 /* At this point, a file exists on "disk"; we need to make sure
278 * that this on disk file is prepared to be an ecryptfs file */
279 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
280 if (rc) {
281 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
282 ecryptfs_inode);
283 iget_failed(ecryptfs_inode);
284 goto out;
285 }
286 d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
287out:
288 return rc;
289}
290
291static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
292{
293 struct ecryptfs_crypt_stat *crypt_stat;
294 int rc;
295
296 rc = ecryptfs_get_lower_file(dentry, inode);
297 if (rc) {
298 printk(KERN_ERR "%s: Error attempting to initialize "
299 "the lower file for the dentry with name "
300 "[%pd]; rc = [%d]\n", __func__,
301 dentry, rc);
302 return rc;
303 }
304
305 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
306 /* TODO: lock for crypt_stat comparison */
307 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
308 ecryptfs_set_default_sizes(crypt_stat);
309
310 rc = ecryptfs_read_and_validate_header_region(inode);
311 ecryptfs_put_lower_file(inode);
312 if (rc) {
313 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
314 if (!rc)
315 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
316 }
317
318 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
319 return 0;
320}
321
322/**
323 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
324 */
325static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
326 struct dentry *lower_dentry)
327{
328 struct inode *inode, *lower_inode = d_inode(lower_dentry);
329 struct ecryptfs_dentry_info *dentry_info;
330 struct vfsmount *lower_mnt;
331 int rc = 0;
332
333 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
334 if (!dentry_info) {
335 dput(lower_dentry);
336 return ERR_PTR(-ENOMEM);
337 }
338
339 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
340 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
341 d_inode(lower_dentry->d_parent));
342 BUG_ON(!d_count(lower_dentry));
343
344 ecryptfs_set_dentry_private(dentry, dentry_info);
345 dentry_info->lower_path.mnt = lower_mnt;
346 dentry_info->lower_path.dentry = lower_dentry;
347
348 if (d_really_is_negative(lower_dentry)) {
349 /* We want to add because we couldn't find in lower */
350 d_add(dentry, NULL);
351 return NULL;
352 }
353 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
354 if (IS_ERR(inode)) {
355 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
356 __func__, PTR_ERR(inode));
357 return ERR_CAST(inode);
358 }
359 if (S_ISREG(inode->i_mode)) {
360 rc = ecryptfs_i_size_read(dentry, inode);
361 if (rc) {
362 make_bad_inode(inode);
363 return ERR_PTR(rc);
364 }
365 }
366
367 if (inode->i_state & I_NEW)
368 unlock_new_inode(inode);
369 return d_splice_alias(inode, dentry);
370}
371
372/**
373 * ecryptfs_lookup
374 * @ecryptfs_dir_inode: The eCryptfs directory inode
375 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
376 * @flags: lookup flags
377 *
378 * Find a file on disk. If the file does not exist, then we'll add it to the
379 * dentry cache and continue on to read it from the disk.
380 */
381static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
382 struct dentry *ecryptfs_dentry,
383 unsigned int flags)
384{
385 char *encrypted_and_encoded_name = NULL;
386 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
387 struct dentry *lower_dir_dentry, *lower_dentry;
388 const char *name = ecryptfs_dentry->d_name.name;
389 size_t len = ecryptfs_dentry->d_name.len;
390 struct dentry *res;
391 int rc = 0;
392
393 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
394
395 mount_crypt_stat = &ecryptfs_superblock_to_private(
396 ecryptfs_dentry->d_sb)->mount_crypt_stat;
397 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
398 rc = ecryptfs_encrypt_and_encode_filename(
399 &encrypted_and_encoded_name, &len,
400 mount_crypt_stat, name, len);
401 if (rc) {
402 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
403 "filename; rc = [%d]\n", __func__, rc);
404 return ERR_PTR(rc);
405 }
406 name = encrypted_and_encoded_name;
407 }
408
409 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
410 if (IS_ERR(lower_dentry)) {
411 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
412 "[%ld] on lower_dentry = [%s]\n", __func__,
413 PTR_ERR(lower_dentry),
414 name);
415 res = ERR_CAST(lower_dentry);
416 } else {
417 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
418 }
419 kfree(encrypted_and_encoded_name);
420 return res;
421}
422
423static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
424 struct dentry *new_dentry)
425{
426 struct dentry *lower_old_dentry;
427 struct dentry *lower_new_dentry;
428 struct dentry *lower_dir_dentry;
429 u64 file_size_save;
430 int rc;
431
432 file_size_save = i_size_read(d_inode(old_dentry));
433 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
434 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
435 dget(lower_old_dentry);
436 dget(lower_new_dentry);
437 lower_dir_dentry = lock_parent(lower_new_dentry);
438 rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
439 lower_new_dentry, NULL);
440 if (rc || d_really_is_negative(lower_new_dentry))
441 goto out_lock;
442 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
443 if (rc)
444 goto out_lock;
445 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
446 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
447 set_nlink(d_inode(old_dentry),
448 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
449 i_size_write(d_inode(new_dentry), file_size_save);
450out_lock:
451 unlock_dir(lower_dir_dentry);
452 dput(lower_new_dentry);
453 dput(lower_old_dentry);
454 return rc;
455}
456
457static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
458{
459 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
460}
461
462static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
463 const char *symname)
464{
465 int rc;
466 struct dentry *lower_dentry;
467 struct dentry *lower_dir_dentry;
468 char *encoded_symname;
469 size_t encoded_symlen;
470 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
471
472 lower_dentry = ecryptfs_dentry_to_lower(dentry);
473 dget(lower_dentry);
474 lower_dir_dentry = lock_parent(lower_dentry);
475 mount_crypt_stat = &ecryptfs_superblock_to_private(
476 dir->i_sb)->mount_crypt_stat;
477 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
478 &encoded_symlen,
479 mount_crypt_stat, symname,
480 strlen(symname));
481 if (rc)
482 goto out_lock;
483 rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
484 encoded_symname);
485 kfree(encoded_symname);
486 if (rc || d_really_is_negative(lower_dentry))
487 goto out_lock;
488 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
489 if (rc)
490 goto out_lock;
491 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
492 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
493out_lock:
494 unlock_dir(lower_dir_dentry);
495 dput(lower_dentry);
496 if (d_really_is_negative(dentry))
497 d_drop(dentry);
498 return rc;
499}
500
501static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
502{
503 int rc;
504 struct dentry *lower_dentry;
505 struct dentry *lower_dir_dentry;
506
507 lower_dentry = ecryptfs_dentry_to_lower(dentry);
508 lower_dir_dentry = lock_parent(lower_dentry);
509 rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
510 if (rc || d_really_is_negative(lower_dentry))
511 goto out;
512 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
513 if (rc)
514 goto out;
515 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
516 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
517 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
518out:
519 unlock_dir(lower_dir_dentry);
520 if (d_really_is_negative(dentry))
521 d_drop(dentry);
522 return rc;
523}
524
525static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
526{
527 struct dentry *lower_dentry;
528 struct dentry *lower_dir_dentry;
529 int rc;
530
531 lower_dentry = ecryptfs_dentry_to_lower(dentry);
532 dget(dentry);
533 lower_dir_dentry = lock_parent(lower_dentry);
534 dget(lower_dentry);
535 rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
536 dput(lower_dentry);
537 if (!rc && d_really_is_positive(dentry))
538 clear_nlink(d_inode(dentry));
539 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
540 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
541 unlock_dir(lower_dir_dentry);
542 if (!rc)
543 d_drop(dentry);
544 dput(dentry);
545 return rc;
546}
547
548static int
549ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
550{
551 int rc;
552 struct dentry *lower_dentry;
553 struct dentry *lower_dir_dentry;
554
555 lower_dentry = ecryptfs_dentry_to_lower(dentry);
556 lower_dir_dentry = lock_parent(lower_dentry);
557 rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
558 if (rc || d_really_is_negative(lower_dentry))
559 goto out;
560 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
561 if (rc)
562 goto out;
563 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
564 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
565out:
566 unlock_dir(lower_dir_dentry);
567 if (d_really_is_negative(dentry))
568 d_drop(dentry);
569 return rc;
570}
571
572static int
573ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
574 struct inode *new_dir, struct dentry *new_dentry,
575 unsigned int flags)
576{
577 int rc;
578 struct dentry *lower_old_dentry;
579 struct dentry *lower_new_dentry;
580 struct dentry *lower_old_dir_dentry;
581 struct dentry *lower_new_dir_dentry;
582 struct dentry *trap = NULL;
583 struct inode *target_inode;
584
585 if (flags)
586 return -EINVAL;
587
588 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
589 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
590 dget(lower_old_dentry);
591 dget(lower_new_dentry);
592 lower_old_dir_dentry = dget_parent(lower_old_dentry);
593 lower_new_dir_dentry = dget_parent(lower_new_dentry);
594 target_inode = d_inode(new_dentry);
595 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
596 /* source should not be ancestor of target */
597 if (trap == lower_old_dentry) {
598 rc = -EINVAL;
599 goto out_lock;
600 }
601 /* target should not be ancestor of source */
602 if (trap == lower_new_dentry) {
603 rc = -ENOTEMPTY;
604 goto out_lock;
605 }
606 rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
607 d_inode(lower_new_dir_dentry), lower_new_dentry,
608 NULL, 0);
609 if (rc)
610 goto out_lock;
611 if (target_inode)
612 fsstack_copy_attr_all(target_inode,
613 ecryptfs_inode_to_lower(target_inode));
614 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
615 if (new_dir != old_dir)
616 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
617out_lock:
618 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
619 dput(lower_new_dir_dentry);
620 dput(lower_old_dir_dentry);
621 dput(lower_new_dentry);
622 dput(lower_old_dentry);
623 return rc;
624}
625
626static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
627{
628 DEFINE_DELAYED_CALL(done);
629 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
630 const char *link;
631 char *buf;
632 int rc;
633
634 link = vfs_get_link(lower_dentry, &done);
635 if (IS_ERR(link))
636 return ERR_CAST(link);
637
638 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
639 link, strlen(link));
640 do_delayed_call(&done);
641 if (rc)
642 return ERR_PTR(rc);
643
644 return buf;
645}
646
647static const char *ecryptfs_get_link(struct dentry *dentry,
648 struct inode *inode,
649 struct delayed_call *done)
650{
651 size_t len;
652 char *buf;
653
654 if (!dentry)
655 return ERR_PTR(-ECHILD);
656
657 buf = ecryptfs_readlink_lower(dentry, &len);
658 if (IS_ERR(buf))
659 return buf;
660 fsstack_copy_attr_atime(d_inode(dentry),
661 d_inode(ecryptfs_dentry_to_lower(dentry)));
662 buf[len] = '\0';
663 set_delayed_call(done, kfree_link, buf);
664 return buf;
665}
666
667/**
668 * upper_size_to_lower_size
669 * @crypt_stat: Crypt_stat associated with file
670 * @upper_size: Size of the upper file
671 *
672 * Calculate the required size of the lower file based on the
673 * specified size of the upper file. This calculation is based on the
674 * number of headers in the underlying file and the extent size.
675 *
676 * Returns Calculated size of the lower file.
677 */
678static loff_t
679upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
680 loff_t upper_size)
681{
682 loff_t lower_size;
683
684 lower_size = ecryptfs_lower_header_size(crypt_stat);
685 if (upper_size != 0) {
686 loff_t num_extents;
687
688 num_extents = upper_size >> crypt_stat->extent_shift;
689 if (upper_size & ~crypt_stat->extent_mask)
690 num_extents++;
691 lower_size += (num_extents * crypt_stat->extent_size);
692 }
693 return lower_size;
694}
695
696/**
697 * truncate_upper
698 * @dentry: The ecryptfs layer dentry
699 * @ia: Address of the ecryptfs inode's attributes
700 * @lower_ia: Address of the lower inode's attributes
701 *
702 * Function to handle truncations modifying the size of the file. Note
703 * that the file sizes are interpolated. When expanding, we are simply
704 * writing strings of 0's out. When truncating, we truncate the upper
705 * inode and update the lower_ia according to the page index
706 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
707 * the caller must use lower_ia in a call to notify_change() to perform
708 * the truncation of the lower inode.
709 *
710 * Returns zero on success; non-zero otherwise
711 */
712static int truncate_upper(struct dentry *dentry, struct iattr *ia,
713 struct iattr *lower_ia)
714{
715 int rc = 0;
716 struct inode *inode = d_inode(dentry);
717 struct ecryptfs_crypt_stat *crypt_stat;
718 loff_t i_size = i_size_read(inode);
719 loff_t lower_size_before_truncate;
720 loff_t lower_size_after_truncate;
721
722 if (unlikely((ia->ia_size == i_size))) {
723 lower_ia->ia_valid &= ~ATTR_SIZE;
724 return 0;
725 }
726 rc = ecryptfs_get_lower_file(dentry, inode);
727 if (rc)
728 return rc;
729 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
730 /* Switch on growing or shrinking file */
731 if (ia->ia_size > i_size) {
732 char zero[] = { 0x00 };
733
734 lower_ia->ia_valid &= ~ATTR_SIZE;
735 /* Write a single 0 at the last position of the file;
736 * this triggers code that will fill in 0's throughout
737 * the intermediate portion of the previous end of the
738 * file and the new and of the file */
739 rc = ecryptfs_write(inode, zero,
740 (ia->ia_size - 1), 1);
741 } else { /* ia->ia_size < i_size_read(inode) */
742 /* We're chopping off all the pages down to the page
743 * in which ia->ia_size is located. Fill in the end of
744 * that page from (ia->ia_size & ~PAGE_MASK) to
745 * PAGE_SIZE with zeros. */
746 size_t num_zeros = (PAGE_SIZE
747 - (ia->ia_size & ~PAGE_MASK));
748
749 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
750 truncate_setsize(inode, ia->ia_size);
751 lower_ia->ia_size = ia->ia_size;
752 lower_ia->ia_valid |= ATTR_SIZE;
753 goto out;
754 }
755 if (num_zeros) {
756 char *zeros_virt;
757
758 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
759 if (!zeros_virt) {
760 rc = -ENOMEM;
761 goto out;
762 }
763 rc = ecryptfs_write(inode, zeros_virt,
764 ia->ia_size, num_zeros);
765 kfree(zeros_virt);
766 if (rc) {
767 printk(KERN_ERR "Error attempting to zero out "
768 "the remainder of the end page on "
769 "reducing truncate; rc = [%d]\n", rc);
770 goto out;
771 }
772 }
773 truncate_setsize(inode, ia->ia_size);
774 rc = ecryptfs_write_inode_size_to_metadata(inode);
775 if (rc) {
776 printk(KERN_ERR "Problem with "
777 "ecryptfs_write_inode_size_to_metadata; "
778 "rc = [%d]\n", rc);
779 goto out;
780 }
781 /* We are reducing the size of the ecryptfs file, and need to
782 * know if we need to reduce the size of the lower file. */
783 lower_size_before_truncate =
784 upper_size_to_lower_size(crypt_stat, i_size);
785 lower_size_after_truncate =
786 upper_size_to_lower_size(crypt_stat, ia->ia_size);
787 if (lower_size_after_truncate < lower_size_before_truncate) {
788 lower_ia->ia_size = lower_size_after_truncate;
789 lower_ia->ia_valid |= ATTR_SIZE;
790 } else
791 lower_ia->ia_valid &= ~ATTR_SIZE;
792 }
793out:
794 ecryptfs_put_lower_file(inode);
795 return rc;
796}
797
798static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
799{
800 struct ecryptfs_crypt_stat *crypt_stat;
801 loff_t lower_oldsize, lower_newsize;
802
803 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
804 lower_oldsize = upper_size_to_lower_size(crypt_stat,
805 i_size_read(inode));
806 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
807 if (lower_newsize > lower_oldsize) {
808 /*
809 * The eCryptfs inode and the new *lower* size are mixed here
810 * because we may not have the lower i_mutex held and/or it may
811 * not be appropriate to call inode_newsize_ok() with inodes
812 * from other filesystems.
813 */
814 return inode_newsize_ok(inode, lower_newsize);
815 }
816
817 return 0;
818}
819
820/**
821 * ecryptfs_truncate
822 * @dentry: The ecryptfs layer dentry
823 * @new_length: The length to expand the file to
824 *
825 * Simple function that handles the truncation of an eCryptfs inode and
826 * its corresponding lower inode.
827 *
828 * Returns zero on success; non-zero otherwise
829 */
830int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
831{
832 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
833 struct iattr lower_ia = { .ia_valid = 0 };
834 int rc;
835
836 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
837 if (rc)
838 return rc;
839
840 rc = truncate_upper(dentry, &ia, &lower_ia);
841 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
842 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
843
844 inode_lock(d_inode(lower_dentry));
845 rc = notify_change(lower_dentry, &lower_ia, NULL);
846 inode_unlock(d_inode(lower_dentry));
847 }
848 return rc;
849}
850
851static int
852ecryptfs_permission(struct inode *inode, int mask)
853{
854 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
855}
856
857/**
858 * ecryptfs_setattr
859 * @dentry: dentry handle to the inode to modify
860 * @ia: Structure with flags of what to change and values
861 *
862 * Updates the metadata of an inode. If the update is to the size
863 * i.e. truncation, then ecryptfs_truncate will handle the size modification
864 * of both the ecryptfs inode and the lower inode.
865 *
866 * All other metadata changes will be passed right to the lower filesystem,
867 * and we will just update our inode to look like the lower.
868 */
869static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
870{
871 int rc = 0;
872 struct dentry *lower_dentry;
873 struct iattr lower_ia;
874 struct inode *inode;
875 struct inode *lower_inode;
876 struct ecryptfs_crypt_stat *crypt_stat;
877
878 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
879 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
880 rc = ecryptfs_init_crypt_stat(crypt_stat);
881 if (rc)
882 return rc;
883 }
884 inode = d_inode(dentry);
885 lower_inode = ecryptfs_inode_to_lower(inode);
886 lower_dentry = ecryptfs_dentry_to_lower(dentry);
887 mutex_lock(&crypt_stat->cs_mutex);
888 if (d_is_dir(dentry))
889 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
890 else if (d_is_reg(dentry)
891 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
892 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
893 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
894
895 mount_crypt_stat = &ecryptfs_superblock_to_private(
896 dentry->d_sb)->mount_crypt_stat;
897 rc = ecryptfs_get_lower_file(dentry, inode);
898 if (rc) {
899 mutex_unlock(&crypt_stat->cs_mutex);
900 goto out;
901 }
902 rc = ecryptfs_read_metadata(dentry);
903 ecryptfs_put_lower_file(inode);
904 if (rc) {
905 if (!(mount_crypt_stat->flags
906 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
907 rc = -EIO;
908 printk(KERN_WARNING "Either the lower file "
909 "is not in a valid eCryptfs format, "
910 "or the key could not be retrieved. "
911 "Plaintext passthrough mode is not "
912 "enabled; returning -EIO\n");
913 mutex_unlock(&crypt_stat->cs_mutex);
914 goto out;
915 }
916 rc = 0;
917 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
918 | ECRYPTFS_ENCRYPTED);
919 }
920 }
921 mutex_unlock(&crypt_stat->cs_mutex);
922
923 rc = setattr_prepare(dentry, ia);
924 if (rc)
925 goto out;
926 if (ia->ia_valid & ATTR_SIZE) {
927 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
928 if (rc)
929 goto out;
930 }
931
932 memcpy(&lower_ia, ia, sizeof(lower_ia));
933 if (ia->ia_valid & ATTR_FILE)
934 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
935 if (ia->ia_valid & ATTR_SIZE) {
936 rc = truncate_upper(dentry, ia, &lower_ia);
937 if (rc < 0)
938 goto out;
939 }
940
941 /*
942 * mode change is for clearing setuid/setgid bits. Allow lower fs
943 * to interpret this in its own way.
944 */
945 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
946 lower_ia.ia_valid &= ~ATTR_MODE;
947
948 inode_lock(d_inode(lower_dentry));
949 rc = notify_change(lower_dentry, &lower_ia, NULL);
950 inode_unlock(d_inode(lower_dentry));
951out:
952 fsstack_copy_attr_all(inode, lower_inode);
953 return rc;
954}
955
956static int ecryptfs_getattr_link(const struct path *path, struct kstat *stat,
957 u32 request_mask, unsigned int flags)
958{
959 struct dentry *dentry = path->dentry;
960 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
961 int rc = 0;
962
963 mount_crypt_stat = &ecryptfs_superblock_to_private(
964 dentry->d_sb)->mount_crypt_stat;
965 generic_fillattr(d_inode(dentry), stat);
966 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
967 char *target;
968 size_t targetsiz;
969
970 target = ecryptfs_readlink_lower(dentry, &targetsiz);
971 if (!IS_ERR(target)) {
972 kfree(target);
973 stat->size = targetsiz;
974 } else {
975 rc = PTR_ERR(target);
976 }
977 }
978 return rc;
979}
980
981static int ecryptfs_getattr(const struct path *path, struct kstat *stat,
982 u32 request_mask, unsigned int flags)
983{
984 struct dentry *dentry = path->dentry;
985 struct kstat lower_stat;
986 int rc;
987
988 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
989 request_mask, flags);
990 if (!rc) {
991 fsstack_copy_attr_all(d_inode(dentry),
992 ecryptfs_inode_to_lower(d_inode(dentry)));
993 generic_fillattr(d_inode(dentry), stat);
994 stat->blocks = lower_stat.blocks;
995 }
996 return rc;
997}
998
999int
1000ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1001 const char *name, const void *value,
1002 size_t size, int flags)
1003{
1004 int rc;
1005 struct dentry *lower_dentry;
1006
1007 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1008 if (!(d_inode(lower_dentry)->i_opflags & IOP_XATTR)) {
1009 rc = -EOPNOTSUPP;
1010 goto out;
1011 }
1012 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1013 if (!rc && inode)
1014 fsstack_copy_attr_all(inode, d_inode(lower_dentry));
1015out:
1016 return rc;
1017}
1018
1019ssize_t
1020ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1021 const char *name, void *value, size_t size)
1022{
1023 int rc;
1024
1025 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1026 rc = -EOPNOTSUPP;
1027 goto out;
1028 }
1029 inode_lock(lower_inode);
1030 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1031 inode_unlock(lower_inode);
1032out:
1033 return rc;
1034}
1035
1036static ssize_t
1037ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1038 const char *name, void *value, size_t size)
1039{
1040 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1041 ecryptfs_inode_to_lower(inode),
1042 name, value, size);
1043}
1044
1045static ssize_t
1046ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1047{
1048 int rc = 0;
1049 struct dentry *lower_dentry;
1050
1051 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1052 if (!d_inode(lower_dentry)->i_op->listxattr) {
1053 rc = -EOPNOTSUPP;
1054 goto out;
1055 }
1056 inode_lock(d_inode(lower_dentry));
1057 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1058 inode_unlock(d_inode(lower_dentry));
1059out:
1060 return rc;
1061}
1062
1063static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1064 const char *name)
1065{
1066 int rc;
1067 struct dentry *lower_dentry;
1068 struct inode *lower_inode;
1069
1070 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1071 lower_inode = ecryptfs_inode_to_lower(inode);
1072 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1073 rc = -EOPNOTSUPP;
1074 goto out;
1075 }
1076 inode_lock(lower_inode);
1077 rc = __vfs_removexattr(lower_dentry, name);
1078 inode_unlock(lower_inode);
1079out:
1080 return rc;
1081}
1082
1083const struct inode_operations ecryptfs_symlink_iops = {
1084 .get_link = ecryptfs_get_link,
1085 .permission = ecryptfs_permission,
1086 .setattr = ecryptfs_setattr,
1087 .getattr = ecryptfs_getattr_link,
1088 .listxattr = ecryptfs_listxattr,
1089};
1090
1091const struct inode_operations ecryptfs_dir_iops = {
1092 .create = ecryptfs_create,
1093 .lookup = ecryptfs_lookup,
1094 .link = ecryptfs_link,
1095 .unlink = ecryptfs_unlink,
1096 .symlink = ecryptfs_symlink,
1097 .mkdir = ecryptfs_mkdir,
1098 .rmdir = ecryptfs_rmdir,
1099 .mknod = ecryptfs_mknod,
1100 .rename = ecryptfs_rename,
1101 .permission = ecryptfs_permission,
1102 .setattr = ecryptfs_setattr,
1103 .listxattr = ecryptfs_listxattr,
1104};
1105
1106const struct inode_operations ecryptfs_main_iops = {
1107 .permission = ecryptfs_permission,
1108 .setattr = ecryptfs_setattr,
1109 .getattr = ecryptfs_getattr,
1110 .listxattr = ecryptfs_listxattr,
1111};
1112
1113static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1114 struct dentry *dentry, struct inode *inode,
1115 const char *name, void *buffer, size_t size)
1116{
1117 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1118}
1119
1120static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1121 struct dentry *dentry, struct inode *inode,
1122 const char *name, const void *value, size_t size,
1123 int flags)
1124{
1125 if (value)
1126 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1127 else {
1128 BUG_ON(flags != XATTR_REPLACE);
1129 return ecryptfs_removexattr(dentry, inode, name);
1130 }
1131}
1132
1133const struct xattr_handler ecryptfs_xattr_handler = {
1134 .prefix = "", /* match anything */
1135 .get = ecryptfs_xattr_get,
1136 .set = ecryptfs_xattr_set,
1137};
1138
1139const struct xattr_handler *ecryptfs_xattr_handlers[] = {
1140 &ecryptfs_xattr_handler,
1141 NULL
1142};