eCryptfs: Copy up lower inode attrs in getattr
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ecryptfs / inode.c
blobb592938a84bc40281d8ee80fc5585783bf7ed1d9
1 /**
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
23 * 02111-1307, USA.
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)
41 struct dentry *dir;
43 dir = dget_parent(dentry);
44 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
45 return dir;
48 static void unlock_dir(struct dentry *dir)
50 mutex_unlock(&dir->d_inode->i_mutex);
51 dput(dir);
54 /**
55 * ecryptfs_create_underlying_file
56 * @lower_dir_inode: inode of the parent in the lower fs of the new file
57 * @dentry: New file's dentry
58 * @mode: The mode of the new file
59 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
61 * Creates the file in the lower file system.
63 * Returns zero on success; non-zero on error condition
65 static int
66 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
67 struct dentry *dentry, int mode,
68 struct nameidata *nd)
70 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
71 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
72 struct dentry *dentry_save;
73 struct vfsmount *vfsmount_save;
74 unsigned int flags_save;
75 int rc;
77 if (nd) {
78 dentry_save = nd->path.dentry;
79 vfsmount_save = nd->path.mnt;
80 flags_save = nd->flags;
81 nd->path.dentry = lower_dentry;
82 nd->path.mnt = lower_mnt;
83 nd->flags &= ~LOOKUP_OPEN;
85 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
86 if (nd) {
87 nd->path.dentry = dentry_save;
88 nd->path.mnt = vfsmount_save;
89 nd->flags = flags_save;
91 return rc;
94 /**
95 * ecryptfs_do_create
96 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
97 * @ecryptfs_dentry: New file's dentry in ecryptfs
98 * @mode: The mode of the new file
99 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
101 * Creates the underlying file and the eCryptfs inode which will link to
102 * it. It will also update the eCryptfs directory inode to mimic the
103 * stat of the lower directory inode.
105 * Returns zero on success; non-zero on error condition
107 static int
108 ecryptfs_do_create(struct inode *directory_inode,
109 struct dentry *ecryptfs_dentry, int mode,
110 struct nameidata *nd)
112 int rc;
113 struct dentry *lower_dentry;
114 struct dentry *lower_dir_dentry;
116 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
117 lower_dir_dentry = lock_parent(lower_dentry);
118 if (IS_ERR(lower_dir_dentry)) {
119 ecryptfs_printk(KERN_ERR, "Error locking directory of "
120 "dentry\n");
121 rc = PTR_ERR(lower_dir_dentry);
122 goto out;
124 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
125 ecryptfs_dentry, mode, nd);
126 if (rc) {
127 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
128 "rc = [%d]\n", __func__, rc);
129 goto out_lock;
131 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
132 directory_inode->i_sb, 0);
133 if (rc) {
134 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
135 goto out_lock;
137 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
138 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
139 out_lock:
140 unlock_dir(lower_dir_dentry);
141 out:
142 return rc;
146 * grow_file
147 * @ecryptfs_dentry: the eCryptfs dentry
149 * This is the code which will grow the file to its correct size.
151 static int grow_file(struct dentry *ecryptfs_dentry)
153 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
154 char zero_virt[] = { 0x00 };
155 int rc = 0;
157 rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1);
158 i_size_write(ecryptfs_inode, 0);
159 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
160 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
161 ECRYPTFS_NEW_FILE;
162 return rc;
166 * ecryptfs_initialize_file
168 * Cause the file to be changed from a basic empty file to an ecryptfs
169 * file with a header and first data page.
171 * Returns zero on success
173 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
175 struct ecryptfs_crypt_stat *crypt_stat =
176 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
177 int rc = 0;
179 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
180 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
181 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
182 goto out;
184 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
185 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
186 rc = ecryptfs_new_file_context(ecryptfs_dentry);
187 if (rc) {
188 ecryptfs_printk(KERN_ERR, "Error creating new file "
189 "context; rc = [%d]\n", rc);
190 goto out;
192 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
193 if (rc) {
194 printk(KERN_ERR "%s: Error attempting to initialize "
195 "the persistent file for the dentry with name "
196 "[%s]; rc = [%d]\n", __func__,
197 ecryptfs_dentry->d_name.name, rc);
198 goto out;
200 rc = ecryptfs_write_metadata(ecryptfs_dentry);
201 if (rc) {
202 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
203 goto out;
205 rc = grow_file(ecryptfs_dentry);
206 if (rc)
207 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
208 out:
209 return rc;
213 * ecryptfs_create
214 * @dir: The inode of the directory in which to create the file.
215 * @dentry: The eCryptfs dentry
216 * @mode: The mode of the new file.
217 * @nd: nameidata
219 * Creates a new file.
221 * Returns zero on success; non-zero on error condition
223 static int
224 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
225 int mode, struct nameidata *nd)
227 int rc;
229 /* ecryptfs_do_create() calls ecryptfs_interpose() */
230 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
231 if (unlikely(rc)) {
232 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
233 "lower filesystem\n");
234 goto out;
236 /* At this point, a file exists on "disk"; we need to make sure
237 * that this on disk file is prepared to be an ecryptfs file */
238 rc = ecryptfs_initialize_file(ecryptfs_dentry);
239 out:
240 return rc;
244 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
246 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
247 struct dentry *lower_dentry,
248 struct inode *ecryptfs_dir_inode)
250 struct dentry *lower_dir_dentry;
251 struct vfsmount *lower_mnt;
252 struct inode *lower_inode;
253 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
254 struct ecryptfs_crypt_stat *crypt_stat;
255 char *page_virt = NULL;
256 u64 file_size;
257 int rc = 0;
259 lower_dir_dentry = lower_dentry->d_parent;
260 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
261 ecryptfs_dentry->d_parent));
262 lower_inode = lower_dentry->d_inode;
263 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
264 BUG_ON(!lower_dentry->d_count);
265 ecryptfs_set_dentry_private(ecryptfs_dentry,
266 kmem_cache_alloc(ecryptfs_dentry_info_cache,
267 GFP_KERNEL));
268 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
269 rc = -ENOMEM;
270 printk(KERN_ERR "%s: Out of memory whilst attempting "
271 "to allocate ecryptfs_dentry_info struct\n",
272 __func__);
273 goto out_put;
275 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
276 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
277 if (!lower_dentry->d_inode) {
278 /* We want to add because we couldn't find in lower */
279 d_add(ecryptfs_dentry, NULL);
280 goto out;
282 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
283 ecryptfs_dir_inode->i_sb,
284 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
285 if (rc) {
286 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
287 __func__, rc);
288 goto out;
290 if (S_ISDIR(lower_inode->i_mode))
291 goto out;
292 if (S_ISLNK(lower_inode->i_mode))
293 goto out;
294 if (special_file(lower_inode->i_mode))
295 goto out;
296 /* Released in this function */
297 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
298 if (!page_virt) {
299 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
300 __func__);
301 rc = -ENOMEM;
302 goto out;
304 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
305 if (rc) {
306 printk(KERN_ERR "%s: Error attempting to initialize "
307 "the persistent file for the dentry with name "
308 "[%s]; rc = [%d]\n", __func__,
309 ecryptfs_dentry->d_name.name, rc);
310 goto out_free_kmem;
312 crypt_stat = &ecryptfs_inode_to_private(
313 ecryptfs_dentry->d_inode)->crypt_stat;
314 /* TODO: lock for crypt_stat comparison */
315 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
316 ecryptfs_set_default_sizes(crypt_stat);
317 rc = ecryptfs_read_and_validate_header_region(page_virt,
318 ecryptfs_dentry->d_inode);
319 if (rc) {
320 memset(page_virt, 0, PAGE_CACHE_SIZE);
321 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
322 ecryptfs_dentry);
323 if (rc) {
324 rc = 0;
325 goto out_free_kmem;
327 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
329 mount_crypt_stat = &ecryptfs_superblock_to_private(
330 ecryptfs_dentry->d_sb)->mount_crypt_stat;
331 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
332 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
333 file_size = (crypt_stat->metadata_size
334 + i_size_read(lower_dentry->d_inode));
335 else
336 file_size = i_size_read(lower_dentry->d_inode);
337 } else {
338 file_size = get_unaligned_be64(page_virt);
340 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
341 out_free_kmem:
342 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
343 goto out;
344 out_put:
345 dput(lower_dentry);
346 mntput(lower_mnt);
347 d_drop(ecryptfs_dentry);
348 out:
349 return rc;
353 * ecryptfs_lookup
354 * @ecryptfs_dir_inode: The eCryptfs directory inode
355 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
356 * @ecryptfs_nd: nameidata; may be NULL
358 * Find a file on disk. If the file does not exist, then we'll add it to the
359 * dentry cache and continue on to read it from the disk.
361 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
362 struct dentry *ecryptfs_dentry,
363 struct nameidata *ecryptfs_nd)
365 char *encrypted_and_encoded_name = NULL;
366 size_t encrypted_and_encoded_name_size;
367 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
368 struct dentry *lower_dir_dentry, *lower_dentry;
369 int rc = 0;
371 if ((ecryptfs_dentry->d_name.len == 1
372 && !strcmp(ecryptfs_dentry->d_name.name, "."))
373 || (ecryptfs_dentry->d_name.len == 2
374 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
375 goto out_d_drop;
377 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
378 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
379 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
380 lower_dir_dentry,
381 ecryptfs_dentry->d_name.len);
382 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
383 if (IS_ERR(lower_dentry)) {
384 rc = PTR_ERR(lower_dentry);
385 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
386 "[%d] on lower_dentry = [%s]\n", __func__, rc,
387 encrypted_and_encoded_name);
388 goto out_d_drop;
390 if (lower_dentry->d_inode)
391 goto lookup_and_interpose;
392 mount_crypt_stat = &ecryptfs_superblock_to_private(
393 ecryptfs_dentry->d_sb)->mount_crypt_stat;
394 if (!(mount_crypt_stat
395 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
396 goto lookup_and_interpose;
397 dput(lower_dentry);
398 rc = ecryptfs_encrypt_and_encode_filename(
399 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
400 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
401 ecryptfs_dentry->d_name.len);
402 if (rc) {
403 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
404 "filename; rc = [%d]\n", __func__, rc);
405 goto out_d_drop;
407 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
408 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
409 lower_dir_dentry,
410 encrypted_and_encoded_name_size);
411 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
412 if (IS_ERR(lower_dentry)) {
413 rc = PTR_ERR(lower_dentry);
414 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
415 "[%d] on lower_dentry = [%s]\n", __func__, rc,
416 encrypted_and_encoded_name);
417 goto out_d_drop;
419 lookup_and_interpose:
420 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
421 ecryptfs_dir_inode);
422 goto out;
423 out_d_drop:
424 d_drop(ecryptfs_dentry);
425 out:
426 kfree(encrypted_and_encoded_name);
427 return ERR_PTR(rc);
430 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
431 struct dentry *new_dentry)
433 struct dentry *lower_old_dentry;
434 struct dentry *lower_new_dentry;
435 struct dentry *lower_dir_dentry;
436 u64 file_size_save;
437 int rc;
439 file_size_save = i_size_read(old_dentry->d_inode);
440 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
441 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
442 dget(lower_old_dentry);
443 dget(lower_new_dentry);
444 lower_dir_dentry = lock_parent(lower_new_dentry);
445 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
446 lower_new_dentry);
447 if (rc || !lower_new_dentry->d_inode)
448 goto out_lock;
449 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
450 if (rc)
451 goto out_lock;
452 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
453 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
454 old_dentry->d_inode->i_nlink =
455 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
456 i_size_write(new_dentry->d_inode, file_size_save);
457 out_lock:
458 unlock_dir(lower_dir_dentry);
459 dput(lower_new_dentry);
460 dput(lower_old_dentry);
461 return rc;
464 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
466 int rc = 0;
467 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
468 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
469 struct dentry *lower_dir_dentry;
471 dget(lower_dentry);
472 lower_dir_dentry = lock_parent(lower_dentry);
473 rc = vfs_unlink(lower_dir_inode, lower_dentry);
474 if (rc) {
475 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
476 goto out_unlock;
478 fsstack_copy_attr_times(dir, lower_dir_inode);
479 dentry->d_inode->i_nlink =
480 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
481 dentry->d_inode->i_ctime = dir->i_ctime;
482 d_drop(dentry);
483 out_unlock:
484 unlock_dir(lower_dir_dentry);
485 dput(lower_dentry);
486 return rc;
489 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
490 const char *symname)
492 int rc;
493 struct dentry *lower_dentry;
494 struct dentry *lower_dir_dentry;
495 char *encoded_symname;
496 size_t encoded_symlen;
497 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
499 lower_dentry = ecryptfs_dentry_to_lower(dentry);
500 dget(lower_dentry);
501 lower_dir_dentry = lock_parent(lower_dentry);
502 mount_crypt_stat = &ecryptfs_superblock_to_private(
503 dir->i_sb)->mount_crypt_stat;
504 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
505 &encoded_symlen,
506 NULL,
507 mount_crypt_stat, symname,
508 strlen(symname));
509 if (rc)
510 goto out_lock;
511 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
512 encoded_symname);
513 kfree(encoded_symname);
514 if (rc || !lower_dentry->d_inode)
515 goto out_lock;
516 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
517 if (rc)
518 goto out_lock;
519 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
520 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
521 out_lock:
522 unlock_dir(lower_dir_dentry);
523 dput(lower_dentry);
524 if (!dentry->d_inode)
525 d_drop(dentry);
526 return rc;
529 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
531 int rc;
532 struct dentry *lower_dentry;
533 struct dentry *lower_dir_dentry;
535 lower_dentry = ecryptfs_dentry_to_lower(dentry);
536 lower_dir_dentry = lock_parent(lower_dentry);
537 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
538 if (rc || !lower_dentry->d_inode)
539 goto out;
540 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
541 if (rc)
542 goto out;
543 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
544 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
545 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
546 out:
547 unlock_dir(lower_dir_dentry);
548 if (!dentry->d_inode)
549 d_drop(dentry);
550 return rc;
553 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
555 struct dentry *lower_dentry;
556 struct dentry *lower_dir_dentry;
557 int rc;
559 lower_dentry = ecryptfs_dentry_to_lower(dentry);
560 dget(dentry);
561 lower_dir_dentry = lock_parent(lower_dentry);
562 dget(lower_dentry);
563 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
564 dput(lower_dentry);
565 if (!rc)
566 d_delete(lower_dentry);
567 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
568 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
569 unlock_dir(lower_dir_dentry);
570 if (!rc)
571 d_drop(dentry);
572 dput(dentry);
573 return rc;
576 static int
577 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
579 int rc;
580 struct dentry *lower_dentry;
581 struct dentry *lower_dir_dentry;
583 lower_dentry = ecryptfs_dentry_to_lower(dentry);
584 lower_dir_dentry = lock_parent(lower_dentry);
585 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
586 if (rc || !lower_dentry->d_inode)
587 goto out;
588 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
589 if (rc)
590 goto out;
591 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
592 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
593 out:
594 unlock_dir(lower_dir_dentry);
595 if (!dentry->d_inode)
596 d_drop(dentry);
597 return rc;
600 static int
601 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
602 struct inode *new_dir, struct dentry *new_dentry)
604 int rc;
605 struct dentry *lower_old_dentry;
606 struct dentry *lower_new_dentry;
607 struct dentry *lower_old_dir_dentry;
608 struct dentry *lower_new_dir_dentry;
609 struct dentry *trap = NULL;
611 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
612 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
613 dget(lower_old_dentry);
614 dget(lower_new_dentry);
615 lower_old_dir_dentry = dget_parent(lower_old_dentry);
616 lower_new_dir_dentry = dget_parent(lower_new_dentry);
617 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
618 /* source should not be ancestor of target */
619 if (trap == lower_old_dentry) {
620 rc = -EINVAL;
621 goto out_lock;
623 /* target should not be ancestor of source */
624 if (trap == lower_new_dentry) {
625 rc = -ENOTEMPTY;
626 goto out_lock;
628 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
629 lower_new_dir_dentry->d_inode, lower_new_dentry);
630 if (rc)
631 goto out_lock;
632 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
633 if (new_dir != old_dir)
634 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
635 out_lock:
636 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
637 dput(lower_new_dentry->d_parent);
638 dput(lower_old_dentry->d_parent);
639 dput(lower_new_dentry);
640 dput(lower_old_dentry);
641 return rc;
644 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
645 size_t *bufsiz)
647 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
648 char *lower_buf;
649 size_t lower_bufsiz = PATH_MAX;
650 mm_segment_t old_fs;
651 int rc;
653 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
654 if (!lower_buf) {
655 rc = -ENOMEM;
656 goto out;
658 old_fs = get_fs();
659 set_fs(get_ds());
660 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
661 (char __user *)lower_buf,
662 lower_bufsiz);
663 set_fs(old_fs);
664 if (rc < 0)
665 goto out;
666 lower_bufsiz = rc;
667 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
668 lower_buf, lower_bufsiz);
669 out:
670 kfree(lower_buf);
671 return rc;
674 static int
675 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
677 char *kbuf;
678 size_t kbufsiz, copied;
679 int rc;
681 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
682 if (rc)
683 goto out;
684 copied = min_t(size_t, bufsiz, kbufsiz);
685 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
686 kfree(kbuf);
687 fsstack_copy_attr_atime(dentry->d_inode,
688 ecryptfs_dentry_to_lower(dentry)->d_inode);
689 out:
690 return rc;
693 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
695 char *buf;
696 int len = PAGE_SIZE, rc;
697 mm_segment_t old_fs;
699 /* Released in ecryptfs_put_link(); only release here on error */
700 buf = kmalloc(len, GFP_KERNEL);
701 if (!buf) {
702 buf = ERR_PTR(-ENOMEM);
703 goto out;
705 old_fs = get_fs();
706 set_fs(get_ds());
707 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
708 set_fs(old_fs);
709 if (rc < 0) {
710 kfree(buf);
711 buf = ERR_PTR(rc);
712 } else
713 buf[rc] = '\0';
714 out:
715 nd_set_link(nd, buf);
716 return NULL;
719 static void
720 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
722 char *buf = nd_get_link(nd);
723 if (!IS_ERR(buf)) {
724 /* Free the char* */
725 kfree(buf);
730 * upper_size_to_lower_size
731 * @crypt_stat: Crypt_stat associated with file
732 * @upper_size: Size of the upper file
734 * Calculate the required size of the lower file based on the
735 * specified size of the upper file. This calculation is based on the
736 * number of headers in the underlying file and the extent size.
738 * Returns Calculated size of the lower file.
740 static loff_t
741 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
742 loff_t upper_size)
744 loff_t lower_size;
746 lower_size = ecryptfs_lower_header_size(crypt_stat);
747 if (upper_size != 0) {
748 loff_t num_extents;
750 num_extents = upper_size >> crypt_stat->extent_shift;
751 if (upper_size & ~crypt_stat->extent_mask)
752 num_extents++;
753 lower_size += (num_extents * crypt_stat->extent_size);
755 return lower_size;
759 * truncate_upper
760 * @dentry: The ecryptfs layer dentry
761 * @ia: Address of the ecryptfs inode's attributes
762 * @lower_ia: Address of the lower inode's attributes
764 * Function to handle truncations modifying the size of the file. Note
765 * that the file sizes are interpolated. When expanding, we are simply
766 * writing strings of 0's out. When truncating, we truncate the upper
767 * inode and update the lower_ia according to the page index
768 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
769 * the caller must use lower_ia in a call to notify_change() to perform
770 * the truncation of the lower inode.
772 * Returns zero on success; non-zero otherwise
774 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
775 struct iattr *lower_ia)
777 int rc = 0;
778 struct inode *inode = dentry->d_inode;
779 struct ecryptfs_crypt_stat *crypt_stat;
780 loff_t i_size = i_size_read(inode);
781 loff_t lower_size_before_truncate;
782 loff_t lower_size_after_truncate;
784 if (unlikely((ia->ia_size == i_size))) {
785 lower_ia->ia_valid &= ~ATTR_SIZE;
786 goto out;
788 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
789 /* Switch on growing or shrinking file */
790 if (ia->ia_size > i_size) {
791 char zero[] = { 0x00 };
793 lower_ia->ia_valid &= ~ATTR_SIZE;
794 /* Write a single 0 at the last position of the file;
795 * this triggers code that will fill in 0's throughout
796 * the intermediate portion of the previous end of the
797 * file and the new and of the file */
798 rc = ecryptfs_write(inode, zero,
799 (ia->ia_size - 1), 1);
800 } else { /* ia->ia_size < i_size_read(inode) */
801 /* We're chopping off all the pages down to the page
802 * in which ia->ia_size is located. Fill in the end of
803 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
804 * PAGE_CACHE_SIZE with zeros. */
805 size_t num_zeros = (PAGE_CACHE_SIZE
806 - (ia->ia_size & ~PAGE_CACHE_MASK));
810 * XXX(truncate) this should really happen at the begginning
811 * of ->setattr. But the code is too messy to that as part
812 * of a larger patch. ecryptfs is also totally missing out
813 * on the inode_change_ok check at the beginning of
814 * ->setattr while would include this.
816 rc = inode_newsize_ok(inode, ia->ia_size);
817 if (rc)
818 goto out;
820 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
821 truncate_setsize(inode, ia->ia_size);
822 lower_ia->ia_size = ia->ia_size;
823 lower_ia->ia_valid |= ATTR_SIZE;
824 goto out;
826 if (num_zeros) {
827 char *zeros_virt;
829 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
830 if (!zeros_virt) {
831 rc = -ENOMEM;
832 goto out;
834 rc = ecryptfs_write(inode, zeros_virt,
835 ia->ia_size, num_zeros);
836 kfree(zeros_virt);
837 if (rc) {
838 printk(KERN_ERR "Error attempting to zero out "
839 "the remainder of the end page on "
840 "reducing truncate; rc = [%d]\n", rc);
841 goto out;
844 truncate_setsize(inode, ia->ia_size);
845 rc = ecryptfs_write_inode_size_to_metadata(inode);
846 if (rc) {
847 printk(KERN_ERR "Problem with "
848 "ecryptfs_write_inode_size_to_metadata; "
849 "rc = [%d]\n", rc);
850 goto out;
852 /* We are reducing the size of the ecryptfs file, and need to
853 * know if we need to reduce the size of the lower file. */
854 lower_size_before_truncate =
855 upper_size_to_lower_size(crypt_stat, i_size);
856 lower_size_after_truncate =
857 upper_size_to_lower_size(crypt_stat, ia->ia_size);
858 if (lower_size_after_truncate < lower_size_before_truncate) {
859 lower_ia->ia_size = lower_size_after_truncate;
860 lower_ia->ia_valid |= ATTR_SIZE;
861 } else
862 lower_ia->ia_valid &= ~ATTR_SIZE;
864 out:
865 return rc;
869 * ecryptfs_truncate
870 * @dentry: The ecryptfs layer dentry
871 * @new_length: The length to expand the file to
873 * Simple function that handles the truncation of an eCryptfs inode and
874 * its corresponding lower inode.
876 * Returns zero on success; non-zero otherwise
878 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
880 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
881 struct iattr lower_ia = { .ia_valid = 0 };
882 int rc;
884 rc = truncate_upper(dentry, &ia, &lower_ia);
885 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
886 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
888 mutex_lock(&lower_dentry->d_inode->i_mutex);
889 rc = notify_change(lower_dentry, &lower_ia);
890 mutex_unlock(&lower_dentry->d_inode->i_mutex);
892 return rc;
895 static int
896 ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
898 if (flags & IPERM_FLAG_RCU)
899 return -ECHILD;
900 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
904 * ecryptfs_setattr
905 * @dentry: dentry handle to the inode to modify
906 * @ia: Structure with flags of what to change and values
908 * Updates the metadata of an inode. If the update is to the size
909 * i.e. truncation, then ecryptfs_truncate will handle the size modification
910 * of both the ecryptfs inode and the lower inode.
912 * All other metadata changes will be passed right to the lower filesystem,
913 * and we will just update our inode to look like the lower.
915 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
917 int rc = 0;
918 struct dentry *lower_dentry;
919 struct iattr lower_ia;
920 struct inode *inode;
921 struct inode *lower_inode;
922 struct ecryptfs_crypt_stat *crypt_stat;
924 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
925 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
926 ecryptfs_init_crypt_stat(crypt_stat);
927 inode = dentry->d_inode;
928 lower_inode = ecryptfs_inode_to_lower(inode);
929 lower_dentry = ecryptfs_dentry_to_lower(dentry);
930 mutex_lock(&crypt_stat->cs_mutex);
931 if (S_ISDIR(dentry->d_inode->i_mode))
932 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
933 else if (S_ISREG(dentry->d_inode->i_mode)
934 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
935 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
936 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
938 mount_crypt_stat = &ecryptfs_superblock_to_private(
939 dentry->d_sb)->mount_crypt_stat;
940 rc = ecryptfs_read_metadata(dentry);
941 if (rc) {
942 if (!(mount_crypt_stat->flags
943 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
944 rc = -EIO;
945 printk(KERN_WARNING "Either the lower file "
946 "is not in a valid eCryptfs format, "
947 "or the key could not be retrieved. "
948 "Plaintext passthrough mode is not "
949 "enabled; returning -EIO\n");
950 mutex_unlock(&crypt_stat->cs_mutex);
951 goto out;
953 rc = 0;
954 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
957 mutex_unlock(&crypt_stat->cs_mutex);
958 memcpy(&lower_ia, ia, sizeof(lower_ia));
959 if (ia->ia_valid & ATTR_FILE)
960 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
961 if (ia->ia_valid & ATTR_SIZE) {
962 rc = truncate_upper(dentry, ia, &lower_ia);
963 if (rc < 0)
964 goto out;
968 * mode change is for clearing setuid/setgid bits. Allow lower fs
969 * to interpret this in its own way.
971 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
972 lower_ia.ia_valid &= ~ATTR_MODE;
974 mutex_lock(&lower_dentry->d_inode->i_mutex);
975 rc = notify_change(lower_dentry, &lower_ia);
976 mutex_unlock(&lower_dentry->d_inode->i_mutex);
977 out:
978 fsstack_copy_attr_all(inode, lower_inode);
979 return rc;
982 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
983 struct kstat *stat)
985 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
986 int rc = 0;
988 mount_crypt_stat = &ecryptfs_superblock_to_private(
989 dentry->d_sb)->mount_crypt_stat;
990 generic_fillattr(dentry->d_inode, stat);
991 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
992 char *target;
993 size_t targetsiz;
995 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
996 if (!rc) {
997 kfree(target);
998 stat->size = targetsiz;
1001 return rc;
1004 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1005 struct kstat *stat)
1007 struct kstat lower_stat;
1008 int rc;
1010 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1011 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1012 if (!rc) {
1013 fsstack_copy_attr_all(dentry->d_inode,
1014 ecryptfs_inode_to_lower(dentry->d_inode));
1015 generic_fillattr(dentry->d_inode, stat);
1016 stat->blocks = lower_stat.blocks;
1018 return rc;
1022 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1023 size_t size, int flags)
1025 int rc = 0;
1026 struct dentry *lower_dentry;
1028 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1029 if (!lower_dentry->d_inode->i_op->setxattr) {
1030 rc = -EOPNOTSUPP;
1031 goto out;
1034 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1035 out:
1036 return rc;
1039 ssize_t
1040 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1041 void *value, size_t size)
1043 int rc = 0;
1045 if (!lower_dentry->d_inode->i_op->getxattr) {
1046 rc = -EOPNOTSUPP;
1047 goto out;
1049 mutex_lock(&lower_dentry->d_inode->i_mutex);
1050 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1051 size);
1052 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1053 out:
1054 return rc;
1057 static ssize_t
1058 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1059 size_t size)
1061 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1062 value, size);
1065 static ssize_t
1066 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1068 int rc = 0;
1069 struct dentry *lower_dentry;
1071 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1072 if (!lower_dentry->d_inode->i_op->listxattr) {
1073 rc = -EOPNOTSUPP;
1074 goto out;
1076 mutex_lock(&lower_dentry->d_inode->i_mutex);
1077 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1078 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1079 out:
1080 return rc;
1083 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1085 int rc = 0;
1086 struct dentry *lower_dentry;
1088 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1089 if (!lower_dentry->d_inode->i_op->removexattr) {
1090 rc = -EOPNOTSUPP;
1091 goto out;
1093 mutex_lock(&lower_dentry->d_inode->i_mutex);
1094 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1095 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1096 out:
1097 return rc;
1100 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1102 if ((ecryptfs_inode_to_lower(inode)
1103 == (struct inode *)candidate_lower_inode))
1104 return 1;
1105 else
1106 return 0;
1109 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1111 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1112 return 0;
1115 const struct inode_operations ecryptfs_symlink_iops = {
1116 .readlink = ecryptfs_readlink,
1117 .follow_link = ecryptfs_follow_link,
1118 .put_link = ecryptfs_put_link,
1119 .permission = ecryptfs_permission,
1120 .setattr = ecryptfs_setattr,
1121 .getattr = ecryptfs_getattr_link,
1122 .setxattr = ecryptfs_setxattr,
1123 .getxattr = ecryptfs_getxattr,
1124 .listxattr = ecryptfs_listxattr,
1125 .removexattr = ecryptfs_removexattr
1128 const struct inode_operations ecryptfs_dir_iops = {
1129 .create = ecryptfs_create,
1130 .lookup = ecryptfs_lookup,
1131 .link = ecryptfs_link,
1132 .unlink = ecryptfs_unlink,
1133 .symlink = ecryptfs_symlink,
1134 .mkdir = ecryptfs_mkdir,
1135 .rmdir = ecryptfs_rmdir,
1136 .mknod = ecryptfs_mknod,
1137 .rename = ecryptfs_rename,
1138 .permission = ecryptfs_permission,
1139 .setattr = ecryptfs_setattr,
1140 .setxattr = ecryptfs_setxattr,
1141 .getxattr = ecryptfs_getxattr,
1142 .listxattr = ecryptfs_listxattr,
1143 .removexattr = ecryptfs_removexattr
1146 const struct inode_operations ecryptfs_main_iops = {
1147 .permission = ecryptfs_permission,
1148 .setattr = ecryptfs_setattr,
1149 .getattr = ecryptfs_getattr,
1150 .setxattr = ecryptfs_setxattr,
1151 .getxattr = ecryptfs_getxattr,
1152 .listxattr = ecryptfs_listxattr,
1153 .removexattr = ecryptfs_removexattr