Driver-core: Always create class directories for classses that support namespaces.
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / fs / ecryptfs / inode.c
blob31ef5252f0fe2f38d94d79b847285965c3ea8626
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 <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry *lock_parent(struct dentry *dentry)
40 struct dentry *dir;
42 dir = dget_parent(dentry);
43 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
44 return dir;
47 static void unlock_dir(struct dentry *dir)
49 mutex_unlock(&dir->d_inode->i_mutex);
50 dput(dir);
53 /**
54 * ecryptfs_create_underlying_file
55 * @lower_dir_inode: inode of the parent in the lower fs of the new file
56 * @dentry: New file's dentry
57 * @mode: The mode of the new file
58 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
60 * Creates the file in the lower file system.
62 * Returns zero on success; non-zero on error condition
64 static int
65 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
66 struct dentry *dentry, int mode,
67 struct nameidata *nd)
69 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
70 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
71 struct dentry *dentry_save;
72 struct vfsmount *vfsmount_save;
73 int rc;
75 dentry_save = nd->path.dentry;
76 vfsmount_save = nd->path.mnt;
77 nd->path.dentry = lower_dentry;
78 nd->path.mnt = lower_mnt;
79 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
80 nd->path.dentry = dentry_save;
81 nd->path.mnt = vfsmount_save;
82 return rc;
85 /**
86 * ecryptfs_do_create
87 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
88 * @ecryptfs_dentry: New file's dentry in ecryptfs
89 * @mode: The mode of the new file
90 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
92 * Creates the underlying file and the eCryptfs inode which will link to
93 * it. It will also update the eCryptfs directory inode to mimic the
94 * stat of the lower directory inode.
96 * Returns zero on success; non-zero on error condition
98 static int
99 ecryptfs_do_create(struct inode *directory_inode,
100 struct dentry *ecryptfs_dentry, int mode,
101 struct nameidata *nd)
103 int rc;
104 struct dentry *lower_dentry;
105 struct dentry *lower_dir_dentry;
107 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
108 lower_dir_dentry = lock_parent(lower_dentry);
109 if (IS_ERR(lower_dir_dentry)) {
110 ecryptfs_printk(KERN_ERR, "Error locking directory of "
111 "dentry\n");
112 rc = PTR_ERR(lower_dir_dentry);
113 goto out;
115 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
116 ecryptfs_dentry, mode, nd);
117 if (rc) {
118 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
119 "rc = [%d]\n", __func__, rc);
120 goto out_lock;
122 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
123 directory_inode->i_sb, 0);
124 if (rc) {
125 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
126 goto out_lock;
128 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
129 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
130 out_lock:
131 unlock_dir(lower_dir_dentry);
132 out:
133 return rc;
137 * grow_file
138 * @ecryptfs_dentry: the eCryptfs dentry
140 * This is the code which will grow the file to its correct size.
142 static int grow_file(struct dentry *ecryptfs_dentry)
144 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
145 char zero_virt[] = { 0x00 };
146 int rc = 0;
148 rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1);
149 i_size_write(ecryptfs_inode, 0);
150 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
151 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
152 ECRYPTFS_NEW_FILE;
153 return rc;
157 * ecryptfs_initialize_file
159 * Cause the file to be changed from a basic empty file to an ecryptfs
160 * file with a header and first data page.
162 * Returns zero on success
164 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
166 struct ecryptfs_crypt_stat *crypt_stat =
167 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
168 int rc = 0;
170 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
171 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
172 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
173 goto out;
175 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
176 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
177 rc = ecryptfs_new_file_context(ecryptfs_dentry);
178 if (rc) {
179 ecryptfs_printk(KERN_ERR, "Error creating new file "
180 "context; rc = [%d]\n", rc);
181 goto out;
183 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
184 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
185 if (rc) {
186 printk(KERN_ERR "%s: Error attempting to initialize "
187 "the persistent file for the dentry with name "
188 "[%s]; rc = [%d]\n", __func__,
189 ecryptfs_dentry->d_name.name, rc);
190 goto out;
193 rc = ecryptfs_write_metadata(ecryptfs_dentry);
194 if (rc) {
195 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
196 goto out;
198 rc = grow_file(ecryptfs_dentry);
199 if (rc)
200 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
201 out:
202 return rc;
206 * ecryptfs_create
207 * @dir: The inode of the directory in which to create the file.
208 * @dentry: The eCryptfs dentry
209 * @mode: The mode of the new file.
210 * @nd: nameidata
212 * Creates a new file.
214 * Returns zero on success; non-zero on error condition
216 static int
217 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
218 int mode, struct nameidata *nd)
220 int rc;
222 /* ecryptfs_do_create() calls ecryptfs_interpose() */
223 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
224 if (unlikely(rc)) {
225 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
226 "lower filesystem\n");
227 goto out;
229 /* At this point, a file exists on "disk"; we need to make sure
230 * that this on disk file is prepared to be an ecryptfs file */
231 rc = ecryptfs_initialize_file(ecryptfs_dentry);
232 out:
233 return rc;
237 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
239 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
240 struct dentry *lower_dentry,
241 struct inode *ecryptfs_dir_inode,
242 struct nameidata *ecryptfs_nd)
244 struct dentry *lower_dir_dentry;
245 struct vfsmount *lower_mnt;
246 struct inode *lower_inode;
247 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
248 struct ecryptfs_crypt_stat *crypt_stat;
249 char *page_virt = NULL;
250 u64 file_size;
251 int rc = 0;
253 lower_dir_dentry = lower_dentry->d_parent;
254 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
255 ecryptfs_dentry->d_parent));
256 lower_inode = lower_dentry->d_inode;
257 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
258 BUG_ON(!atomic_read(&lower_dentry->d_count));
259 ecryptfs_set_dentry_private(ecryptfs_dentry,
260 kmem_cache_alloc(ecryptfs_dentry_info_cache,
261 GFP_KERNEL));
262 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
263 rc = -ENOMEM;
264 printk(KERN_ERR "%s: Out of memory whilst attempting "
265 "to allocate ecryptfs_dentry_info struct\n",
266 __func__);
267 goto out_dput;
269 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
270 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
271 if (!lower_dentry->d_inode) {
272 /* We want to add because we couldn't find in lower */
273 d_add(ecryptfs_dentry, NULL);
274 goto out;
276 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
277 ecryptfs_dir_inode->i_sb,
278 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
279 if (rc) {
280 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
281 __func__, rc);
282 goto out;
284 if (S_ISDIR(lower_inode->i_mode))
285 goto out;
286 if (S_ISLNK(lower_inode->i_mode))
287 goto out;
288 if (special_file(lower_inode->i_mode))
289 goto out;
290 if (!ecryptfs_nd)
291 goto out;
292 /* Released in this function */
293 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
294 if (!page_virt) {
295 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
296 __func__);
297 rc = -ENOMEM;
298 goto out;
300 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
301 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
302 if (rc) {
303 printk(KERN_ERR "%s: Error attempting to initialize "
304 "the persistent file for the dentry with name "
305 "[%s]; rc = [%d]\n", __func__,
306 ecryptfs_dentry->d_name.name, rc);
307 goto out_free_kmem;
310 crypt_stat = &ecryptfs_inode_to_private(
311 ecryptfs_dentry->d_inode)->crypt_stat;
312 /* TODO: lock for crypt_stat comparison */
313 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
314 ecryptfs_set_default_sizes(crypt_stat);
315 rc = ecryptfs_read_and_validate_header_region(page_virt,
316 ecryptfs_dentry->d_inode);
317 if (rc) {
318 memset(page_virt, 0, PAGE_CACHE_SIZE);
319 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
320 ecryptfs_dentry);
321 if (rc) {
322 rc = 0;
323 goto out_free_kmem;
325 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
327 mount_crypt_stat = &ecryptfs_superblock_to_private(
328 ecryptfs_dentry->d_sb)->mount_crypt_stat;
329 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
330 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
331 file_size = (crypt_stat->metadata_size
332 + i_size_read(lower_dentry->d_inode));
333 else
334 file_size = i_size_read(lower_dentry->d_inode);
335 } else {
336 file_size = get_unaligned_be64(page_virt);
338 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
339 out_free_kmem:
340 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
341 goto out;
342 out_dput:
343 dput(lower_dentry);
344 d_drop(ecryptfs_dentry);
345 out:
346 return rc;
350 * ecryptfs_lookup
351 * @ecryptfs_dir_inode: The eCryptfs directory inode
352 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
353 * @ecryptfs_nd: nameidata; may be NULL
355 * Find a file on disk. If the file does not exist, then we'll add it to the
356 * dentry cache and continue on to read it from the disk.
358 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
359 struct dentry *ecryptfs_dentry,
360 struct nameidata *ecryptfs_nd)
362 char *encrypted_and_encoded_name = NULL;
363 size_t encrypted_and_encoded_name_size;
364 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
365 struct dentry *lower_dir_dentry, *lower_dentry;
366 int rc = 0;
368 ecryptfs_dentry->d_op = &ecryptfs_dops;
369 if ((ecryptfs_dentry->d_name.len == 1
370 && !strcmp(ecryptfs_dentry->d_name.name, "."))
371 || (ecryptfs_dentry->d_name.len == 2
372 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
373 goto out_d_drop;
375 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
376 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
377 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
378 lower_dir_dentry,
379 ecryptfs_dentry->d_name.len);
380 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
381 if (IS_ERR(lower_dentry)) {
382 rc = PTR_ERR(lower_dentry);
383 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
384 "[%d] on lower_dentry = [%s]\n", __func__, rc,
385 encrypted_and_encoded_name);
386 goto out_d_drop;
388 if (lower_dentry->d_inode)
389 goto lookup_and_interpose;
390 mount_crypt_stat = &ecryptfs_superblock_to_private(
391 ecryptfs_dentry->d_sb)->mount_crypt_stat;
392 if (!(mount_crypt_stat
393 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
394 goto lookup_and_interpose;
395 dput(lower_dentry);
396 rc = ecryptfs_encrypt_and_encode_filename(
397 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
398 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
399 ecryptfs_dentry->d_name.len);
400 if (rc) {
401 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
402 "filename; rc = [%d]\n", __func__, rc);
403 goto out_d_drop;
405 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
406 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
407 lower_dir_dentry,
408 encrypted_and_encoded_name_size - 1);
409 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
410 if (IS_ERR(lower_dentry)) {
411 rc = PTR_ERR(lower_dentry);
412 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
413 "[%d] on lower_dentry = [%s]\n", __func__, rc,
414 encrypted_and_encoded_name);
415 goto out_d_drop;
417 lookup_and_interpose:
418 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
419 ecryptfs_dir_inode,
420 ecryptfs_nd);
421 goto out;
422 out_d_drop:
423 d_drop(ecryptfs_dentry);
424 out:
425 kfree(encrypted_and_encoded_name);
426 return ERR_PTR(rc);
429 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
430 struct dentry *new_dentry)
432 struct dentry *lower_old_dentry;
433 struct dentry *lower_new_dentry;
434 struct dentry *lower_dir_dentry;
435 u64 file_size_save;
436 int rc;
438 file_size_save = i_size_read(old_dentry->d_inode);
439 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
440 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
441 dget(lower_old_dentry);
442 dget(lower_new_dentry);
443 lower_dir_dentry = lock_parent(lower_new_dentry);
444 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
445 lower_new_dentry);
446 if (rc || !lower_new_dentry->d_inode)
447 goto out_lock;
448 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
449 if (rc)
450 goto out_lock;
451 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
452 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
453 old_dentry->d_inode->i_nlink =
454 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
455 i_size_write(new_dentry->d_inode, file_size_save);
456 out_lock:
457 unlock_dir(lower_dir_dentry);
458 dput(lower_new_dentry);
459 dput(lower_old_dentry);
460 return rc;
463 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
465 int rc = 0;
466 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
467 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
468 struct dentry *lower_dir_dentry;
470 dget(lower_dentry);
471 lower_dir_dentry = lock_parent(lower_dentry);
472 rc = vfs_unlink(lower_dir_inode, lower_dentry);
473 if (rc) {
474 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
475 goto out_unlock;
477 fsstack_copy_attr_times(dir, lower_dir_inode);
478 dentry->d_inode->i_nlink =
479 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
480 dentry->d_inode->i_ctime = dir->i_ctime;
481 d_drop(dentry);
482 out_unlock:
483 unlock_dir(lower_dir_dentry);
484 dput(lower_dentry);
485 return rc;
488 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
489 const char *symname)
491 int rc;
492 struct dentry *lower_dentry;
493 struct dentry *lower_dir_dentry;
494 char *encoded_symname;
495 size_t encoded_symlen;
496 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
498 lower_dentry = ecryptfs_dentry_to_lower(dentry);
499 dget(lower_dentry);
500 lower_dir_dentry = lock_parent(lower_dentry);
501 mount_crypt_stat = &ecryptfs_superblock_to_private(
502 dir->i_sb)->mount_crypt_stat;
503 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
504 &encoded_symlen,
505 NULL,
506 mount_crypt_stat, symname,
507 strlen(symname));
508 if (rc)
509 goto out_lock;
510 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
511 encoded_symname);
512 kfree(encoded_symname);
513 if (rc || !lower_dentry->d_inode)
514 goto out_lock;
515 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
516 if (rc)
517 goto out_lock;
518 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
519 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
520 out_lock:
521 unlock_dir(lower_dir_dentry);
522 dput(lower_dentry);
523 if (!dentry->d_inode)
524 d_drop(dentry);
525 return rc;
528 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
530 int rc;
531 struct dentry *lower_dentry;
532 struct dentry *lower_dir_dentry;
534 lower_dentry = ecryptfs_dentry_to_lower(dentry);
535 lower_dir_dentry = lock_parent(lower_dentry);
536 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
537 if (rc || !lower_dentry->d_inode)
538 goto out;
539 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
540 if (rc)
541 goto out;
542 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
543 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
544 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
545 out:
546 unlock_dir(lower_dir_dentry);
547 if (!dentry->d_inode)
548 d_drop(dentry);
549 return rc;
552 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
554 struct dentry *lower_dentry;
555 struct dentry *lower_dir_dentry;
556 int rc;
558 lower_dentry = ecryptfs_dentry_to_lower(dentry);
559 dget(dentry);
560 lower_dir_dentry = lock_parent(lower_dentry);
561 dget(lower_dentry);
562 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
563 dput(lower_dentry);
564 if (!rc)
565 d_delete(lower_dentry);
566 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
567 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
568 unlock_dir(lower_dir_dentry);
569 if (!rc)
570 d_drop(dentry);
571 dput(dentry);
572 return rc;
575 static int
576 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
578 int rc;
579 struct dentry *lower_dentry;
580 struct dentry *lower_dir_dentry;
582 lower_dentry = ecryptfs_dentry_to_lower(dentry);
583 lower_dir_dentry = lock_parent(lower_dentry);
584 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
585 if (rc || !lower_dentry->d_inode)
586 goto out;
587 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
588 if (rc)
589 goto out;
590 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
591 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
592 out:
593 unlock_dir(lower_dir_dentry);
594 if (!dentry->d_inode)
595 d_drop(dentry);
596 return rc;
599 static int
600 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
601 struct inode *new_dir, struct dentry *new_dentry)
603 int rc;
604 struct dentry *lower_old_dentry;
605 struct dentry *lower_new_dentry;
606 struct dentry *lower_old_dir_dentry;
607 struct dentry *lower_new_dir_dentry;
608 struct dentry *trap = NULL;
610 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
611 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
612 dget(lower_old_dentry);
613 dget(lower_new_dentry);
614 lower_old_dir_dentry = dget_parent(lower_old_dentry);
615 lower_new_dir_dentry = dget_parent(lower_new_dentry);
616 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
617 /* source should not be ancestor of target */
618 if (trap == lower_old_dentry) {
619 rc = -EINVAL;
620 goto out_lock;
622 /* target should not be ancestor of source */
623 if (trap == lower_new_dentry) {
624 rc = -ENOTEMPTY;
625 goto out_lock;
627 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
628 lower_new_dir_dentry->d_inode, lower_new_dentry);
629 if (rc)
630 goto out_lock;
631 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
632 if (new_dir != old_dir)
633 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
634 out_lock:
635 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
636 dput(lower_new_dentry->d_parent);
637 dput(lower_old_dentry->d_parent);
638 dput(lower_new_dentry);
639 dput(lower_old_dentry);
640 return rc;
643 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
644 size_t *bufsiz)
646 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
647 char *lower_buf;
648 size_t lower_bufsiz = PATH_MAX;
649 mm_segment_t old_fs;
650 int rc;
652 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
653 if (!lower_buf) {
654 rc = -ENOMEM;
655 goto out;
657 old_fs = get_fs();
658 set_fs(get_ds());
659 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
660 (char __user *)lower_buf,
661 lower_bufsiz);
662 set_fs(old_fs);
663 if (rc < 0)
664 goto out;
665 lower_bufsiz = rc;
666 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
667 lower_buf, lower_bufsiz);
668 out:
669 kfree(lower_buf);
670 return rc;
673 static int
674 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
676 char *kbuf;
677 size_t kbufsiz, copied;
678 int rc;
680 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
681 if (rc)
682 goto out;
683 copied = min_t(size_t, bufsiz, kbufsiz);
684 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
685 kfree(kbuf);
686 fsstack_copy_attr_atime(dentry->d_inode,
687 ecryptfs_dentry_to_lower(dentry)->d_inode);
688 out:
689 return rc;
692 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
694 char *buf;
695 int len = PAGE_SIZE, rc;
696 mm_segment_t old_fs;
698 /* Released in ecryptfs_put_link(); only release here on error */
699 buf = kmalloc(len, GFP_KERNEL);
700 if (!buf) {
701 buf = ERR_PTR(-ENOMEM);
702 goto out;
704 old_fs = get_fs();
705 set_fs(get_ds());
706 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
707 set_fs(old_fs);
708 if (rc < 0) {
709 kfree(buf);
710 buf = ERR_PTR(rc);
711 } else
712 buf[rc] = '\0';
713 out:
714 nd_set_link(nd, buf);
715 return NULL;
718 static void
719 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
721 char *buf = nd_get_link(nd);
722 if (!IS_ERR(buf)) {
723 /* Free the char* */
724 kfree(buf);
729 * upper_size_to_lower_size
730 * @crypt_stat: Crypt_stat associated with file
731 * @upper_size: Size of the upper file
733 * Calculate the required size of the lower file based on the
734 * specified size of the upper file. This calculation is based on the
735 * number of headers in the underlying file and the extent size.
737 * Returns Calculated size of the lower file.
739 static loff_t
740 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
741 loff_t upper_size)
743 loff_t lower_size;
745 lower_size = ecryptfs_lower_header_size(crypt_stat);
746 if (upper_size != 0) {
747 loff_t num_extents;
749 num_extents = upper_size >> crypt_stat->extent_shift;
750 if (upper_size & ~crypt_stat->extent_mask)
751 num_extents++;
752 lower_size += (num_extents * crypt_stat->extent_size);
754 return lower_size;
758 * truncate_upper
759 * @dentry: The ecryptfs layer dentry
760 * @ia: Address of the ecryptfs inode's attributes
761 * @lower_ia: Address of the lower inode's attributes
763 * Function to handle truncations modifying the size of the file. Note
764 * that the file sizes are interpolated. When expanding, we are simply
765 * writing strings of 0's out. When truncating, we truncate the upper
766 * inode and update the lower_ia according to the page index
767 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
768 * the caller must use lower_ia in a call to notify_change() to perform
769 * the truncation of the lower inode.
771 * Returns zero on success; non-zero otherwise
773 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
774 struct iattr *lower_ia)
776 int rc = 0;
777 struct inode *inode = dentry->d_inode;
778 struct ecryptfs_crypt_stat *crypt_stat;
779 loff_t i_size = i_size_read(inode);
780 loff_t lower_size_before_truncate;
781 loff_t lower_size_after_truncate;
783 if (unlikely((ia->ia_size == i_size))) {
784 lower_ia->ia_valid &= ~ATTR_SIZE;
785 goto out;
787 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
788 /* Switch on growing or shrinking file */
789 if (ia->ia_size > i_size) {
790 char zero[] = { 0x00 };
792 lower_ia->ia_valid &= ~ATTR_SIZE;
793 /* Write a single 0 at the last position of the file;
794 * this triggers code that will fill in 0's throughout
795 * the intermediate portion of the previous end of the
796 * file and the new and of the file */
797 rc = ecryptfs_write(inode, zero,
798 (ia->ia_size - 1), 1);
799 } else { /* ia->ia_size < i_size_read(inode) */
800 /* We're chopping off all the pages down to the page
801 * in which ia->ia_size is located. Fill in the end of
802 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
803 * PAGE_CACHE_SIZE with zeros. */
804 size_t num_zeros = (PAGE_CACHE_SIZE
805 - (ia->ia_size & ~PAGE_CACHE_MASK));
807 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
808 rc = simple_setsize(inode, ia->ia_size);
809 if (rc)
810 goto out;
811 lower_ia->ia_size = ia->ia_size;
812 lower_ia->ia_valid |= ATTR_SIZE;
813 goto out;
815 if (num_zeros) {
816 char *zeros_virt;
818 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
819 if (!zeros_virt) {
820 rc = -ENOMEM;
821 goto out;
823 rc = ecryptfs_write(inode, zeros_virt,
824 ia->ia_size, num_zeros);
825 kfree(zeros_virt);
826 if (rc) {
827 printk(KERN_ERR "Error attempting to zero out "
828 "the remainder of the end page on "
829 "reducing truncate; rc = [%d]\n", rc);
830 goto out;
833 simple_setsize(inode, ia->ia_size);
834 rc = ecryptfs_write_inode_size_to_metadata(inode);
835 if (rc) {
836 printk(KERN_ERR "Problem with "
837 "ecryptfs_write_inode_size_to_metadata; "
838 "rc = [%d]\n", rc);
839 goto out;
841 /* We are reducing the size of the ecryptfs file, and need to
842 * know if we need to reduce the size of the lower file. */
843 lower_size_before_truncate =
844 upper_size_to_lower_size(crypt_stat, i_size);
845 lower_size_after_truncate =
846 upper_size_to_lower_size(crypt_stat, ia->ia_size);
847 if (lower_size_after_truncate < lower_size_before_truncate) {
848 lower_ia->ia_size = lower_size_after_truncate;
849 lower_ia->ia_valid |= ATTR_SIZE;
850 } else
851 lower_ia->ia_valid &= ~ATTR_SIZE;
853 out:
854 return rc;
858 * ecryptfs_truncate
859 * @dentry: The ecryptfs layer dentry
860 * @new_length: The length to expand the file to
862 * Simple function that handles the truncation of an eCryptfs inode and
863 * its corresponding lower inode.
865 * Returns zero on success; non-zero otherwise
867 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
869 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
870 struct iattr lower_ia = { .ia_valid = 0 };
871 int rc;
873 rc = truncate_upper(dentry, &ia, &lower_ia);
874 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
875 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
877 mutex_lock(&lower_dentry->d_inode->i_mutex);
878 rc = notify_change(lower_dentry, &lower_ia);
879 mutex_unlock(&lower_dentry->d_inode->i_mutex);
881 return rc;
884 static int
885 ecryptfs_permission(struct inode *inode, int mask)
887 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
891 * ecryptfs_setattr
892 * @dentry: dentry handle to the inode to modify
893 * @ia: Structure with flags of what to change and values
895 * Updates the metadata of an inode. If the update is to the size
896 * i.e. truncation, then ecryptfs_truncate will handle the size modification
897 * of both the ecryptfs inode and the lower inode.
899 * All other metadata changes will be passed right to the lower filesystem,
900 * and we will just update our inode to look like the lower.
902 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
904 int rc = 0;
905 struct dentry *lower_dentry;
906 struct iattr lower_ia;
907 struct inode *inode;
908 struct inode *lower_inode;
909 struct ecryptfs_crypt_stat *crypt_stat;
911 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
912 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
913 ecryptfs_init_crypt_stat(crypt_stat);
914 inode = dentry->d_inode;
915 lower_inode = ecryptfs_inode_to_lower(inode);
916 lower_dentry = ecryptfs_dentry_to_lower(dentry);
917 mutex_lock(&crypt_stat->cs_mutex);
918 if (S_ISDIR(dentry->d_inode->i_mode))
919 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
920 else if (S_ISREG(dentry->d_inode->i_mode)
921 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
922 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
923 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
925 mount_crypt_stat = &ecryptfs_superblock_to_private(
926 dentry->d_sb)->mount_crypt_stat;
927 rc = ecryptfs_read_metadata(dentry);
928 if (rc) {
929 if (!(mount_crypt_stat->flags
930 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
931 rc = -EIO;
932 printk(KERN_WARNING "Either the lower file "
933 "is not in a valid eCryptfs format, "
934 "or the key could not be retrieved. "
935 "Plaintext passthrough mode is not "
936 "enabled; returning -EIO\n");
937 mutex_unlock(&crypt_stat->cs_mutex);
938 goto out;
940 rc = 0;
941 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
944 mutex_unlock(&crypt_stat->cs_mutex);
945 memcpy(&lower_ia, ia, sizeof(lower_ia));
946 if (ia->ia_valid & ATTR_FILE)
947 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
948 if (ia->ia_valid & ATTR_SIZE) {
949 rc = truncate_upper(dentry, ia, &lower_ia);
950 if (rc < 0)
951 goto out;
955 * mode change is for clearing setuid/setgid bits. Allow lower fs
956 * to interpret this in its own way.
958 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
959 lower_ia.ia_valid &= ~ATTR_MODE;
961 mutex_lock(&lower_dentry->d_inode->i_mutex);
962 rc = notify_change(lower_dentry, &lower_ia);
963 mutex_unlock(&lower_dentry->d_inode->i_mutex);
964 out:
965 fsstack_copy_attr_all(inode, lower_inode);
966 return rc;
969 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
970 struct kstat *stat)
972 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
973 int rc = 0;
975 mount_crypt_stat = &ecryptfs_superblock_to_private(
976 dentry->d_sb)->mount_crypt_stat;
977 generic_fillattr(dentry->d_inode, stat);
978 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
979 char *target;
980 size_t targetsiz;
982 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
983 if (!rc) {
984 kfree(target);
985 stat->size = targetsiz;
988 return rc;
991 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
992 struct kstat *stat)
994 struct kstat lower_stat;
995 int rc;
997 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
998 ecryptfs_dentry_to_lower(dentry), &lower_stat);
999 if (!rc) {
1000 generic_fillattr(dentry->d_inode, stat);
1001 stat->blocks = lower_stat.blocks;
1003 return rc;
1007 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1008 size_t size, int flags)
1010 int rc = 0;
1011 struct dentry *lower_dentry;
1013 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1014 if (!lower_dentry->d_inode->i_op->setxattr) {
1015 rc = -EOPNOTSUPP;
1016 goto out;
1018 mutex_lock(&lower_dentry->d_inode->i_mutex);
1019 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
1020 size, flags);
1021 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1022 out:
1023 return rc;
1026 ssize_t
1027 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1028 void *value, size_t size)
1030 int rc = 0;
1032 if (!lower_dentry->d_inode->i_op->getxattr) {
1033 rc = -EOPNOTSUPP;
1034 goto out;
1036 mutex_lock(&lower_dentry->d_inode->i_mutex);
1037 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1038 size);
1039 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1040 out:
1041 return rc;
1044 static ssize_t
1045 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1046 size_t size)
1048 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1049 value, size);
1052 static ssize_t
1053 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1055 int rc = 0;
1056 struct dentry *lower_dentry;
1058 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1059 if (!lower_dentry->d_inode->i_op->listxattr) {
1060 rc = -EOPNOTSUPP;
1061 goto out;
1063 mutex_lock(&lower_dentry->d_inode->i_mutex);
1064 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1065 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1066 out:
1067 return rc;
1070 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1072 int rc = 0;
1073 struct dentry *lower_dentry;
1075 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1076 if (!lower_dentry->d_inode->i_op->removexattr) {
1077 rc = -EOPNOTSUPP;
1078 goto out;
1080 mutex_lock(&lower_dentry->d_inode->i_mutex);
1081 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1082 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1083 out:
1084 return rc;
1087 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1089 if ((ecryptfs_inode_to_lower(inode)
1090 == (struct inode *)candidate_lower_inode))
1091 return 1;
1092 else
1093 return 0;
1096 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1098 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1099 return 0;
1102 const struct inode_operations ecryptfs_symlink_iops = {
1103 .readlink = ecryptfs_readlink,
1104 .follow_link = ecryptfs_follow_link,
1105 .put_link = ecryptfs_put_link,
1106 .permission = ecryptfs_permission,
1107 .setattr = ecryptfs_setattr,
1108 .getattr = ecryptfs_getattr_link,
1109 .setxattr = ecryptfs_setxattr,
1110 .getxattr = ecryptfs_getxattr,
1111 .listxattr = ecryptfs_listxattr,
1112 .removexattr = ecryptfs_removexattr
1115 const struct inode_operations ecryptfs_dir_iops = {
1116 .create = ecryptfs_create,
1117 .lookup = ecryptfs_lookup,
1118 .link = ecryptfs_link,
1119 .unlink = ecryptfs_unlink,
1120 .symlink = ecryptfs_symlink,
1121 .mkdir = ecryptfs_mkdir,
1122 .rmdir = ecryptfs_rmdir,
1123 .mknod = ecryptfs_mknod,
1124 .rename = ecryptfs_rename,
1125 .permission = ecryptfs_permission,
1126 .setattr = ecryptfs_setattr,
1127 .setxattr = ecryptfs_setxattr,
1128 .getxattr = ecryptfs_getxattr,
1129 .listxattr = ecryptfs_listxattr,
1130 .removexattr = ecryptfs_removexattr
1133 const struct inode_operations ecryptfs_main_iops = {
1134 .permission = ecryptfs_permission,
1135 .setattr = ecryptfs_setattr,
1136 .getattr = ecryptfs_getattr,
1137 .setxattr = ecryptfs_setxattr,
1138 .getxattr = ecryptfs_getxattr,
1139 .listxattr = ecryptfs_listxattr,
1140 .removexattr = ecryptfs_removexattr