2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry *lock_parent(struct dentry *dentry)
43 dir = dget_parent(dentry);
44 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
48 static void unlock_dir(struct dentry *dir)
50 mutex_unlock(&dir->d_inode->i_mutex);
55 * ecryptfs_create_underlying_file
56 * @lower_dir_inode: inode of the parent in the lower fs of the new file
57 * @dentry: New file's dentry
58 * @mode: The mode of the new file
59 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
61 * Creates the file in the lower file system.
63 * Returns zero on success; non-zero on error condition
66 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
67 struct dentry *dentry, int mode,
70 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
71 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
72 struct dentry *dentry_save;
73 struct vfsmount *vfsmount_save;
74 unsigned int flags_save;
78 dentry_save = nd->path.dentry;
79 vfsmount_save = nd->path.mnt;
80 flags_save = nd->flags;
81 nd->path.dentry = lower_dentry;
82 nd->path.mnt = lower_mnt;
83 nd->flags &= ~LOOKUP_OPEN;
85 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
87 nd->path.dentry = dentry_save;
88 nd->path.mnt = vfsmount_save;
89 nd->flags = flags_save;
96 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
97 * @ecryptfs_dentry: New file's dentry in ecryptfs
98 * @mode: The mode of the new file
99 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
101 * Creates the underlying file and the eCryptfs inode which will link to
102 * it. It will also update the eCryptfs directory inode to mimic the
103 * stat of the lower directory inode.
105 * Returns zero on success; non-zero on error condition
108 ecryptfs_do_create(struct inode *directory_inode,
109 struct dentry *ecryptfs_dentry, int mode,
110 struct nameidata *nd)
113 struct dentry *lower_dentry;
114 struct dentry *lower_dir_dentry;
116 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
117 lower_dir_dentry = lock_parent(lower_dentry);
118 if (IS_ERR(lower_dir_dentry)) {
119 ecryptfs_printk(KERN_ERR, "Error locking directory of "
121 rc = PTR_ERR(lower_dir_dentry);
124 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
125 ecryptfs_dentry, mode, nd);
127 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
128 "rc = [%d]\n", __func__, rc);
131 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
132 directory_inode->i_sb, 0);
134 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
137 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
138 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
140 unlock_dir(lower_dir_dentry);
146 * ecryptfs_initialize_file
148 * Cause the file to be changed from a basic empty file to an ecryptfs
149 * file with a header and first data page.
151 * Returns zero on success
153 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
155 struct ecryptfs_crypt_stat *crypt_stat =
156 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
159 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
160 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
161 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
164 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
165 rc = ecryptfs_new_file_context(ecryptfs_dentry);
167 ecryptfs_printk(KERN_ERR, "Error creating new file "
168 "context; rc = [%d]\n", rc);
171 rc = ecryptfs_get_lower_file(ecryptfs_dentry);
173 printk(KERN_ERR "%s: Error attempting to initialize "
174 "the lower file for the dentry with name "
175 "[%s]; rc = [%d]\n", __func__,
176 ecryptfs_dentry->d_name.name, rc);
179 rc = ecryptfs_write_metadata(ecryptfs_dentry);
181 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
182 ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
189 * @dir: The inode of the directory in which to create the file.
190 * @dentry: The eCryptfs dentry
191 * @mode: The mode of the new file.
194 * Creates a new file.
196 * Returns zero on success; non-zero on error condition
199 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
200 int mode, struct nameidata *nd)
204 /* ecryptfs_do_create() calls ecryptfs_interpose() */
205 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
207 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
208 "lower filesystem\n");
211 /* At this point, a file exists on "disk"; we need to make sure
212 * that this on disk file is prepared to be an ecryptfs file */
213 rc = ecryptfs_initialize_file(ecryptfs_dentry);
219 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
221 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
222 struct dentry *lower_dentry,
223 struct inode *ecryptfs_dir_inode)
225 struct dentry *lower_dir_dentry;
226 struct vfsmount *lower_mnt;
227 struct inode *lower_inode;
228 struct ecryptfs_crypt_stat *crypt_stat;
229 char *page_virt = NULL;
230 int put_lower = 0, rc = 0;
232 lower_dir_dentry = lower_dentry->d_parent;
233 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
234 ecryptfs_dentry->d_parent));
235 lower_inode = lower_dentry->d_inode;
236 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
237 BUG_ON(!lower_dentry->d_count);
238 ecryptfs_set_dentry_private(ecryptfs_dentry,
239 kmem_cache_alloc(ecryptfs_dentry_info_cache,
241 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
243 printk(KERN_ERR "%s: Out of memory whilst attempting "
244 "to allocate ecryptfs_dentry_info struct\n",
248 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
249 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
250 if (!lower_dentry->d_inode) {
251 /* We want to add because we couldn't find in lower */
252 d_add(ecryptfs_dentry, NULL);
255 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
256 ecryptfs_dir_inode->i_sb,
257 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
259 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
263 if (S_ISDIR(lower_inode->i_mode))
265 if (S_ISLNK(lower_inode->i_mode))
267 if (special_file(lower_inode->i_mode))
269 /* Released in this function */
270 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
272 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
277 rc = ecryptfs_get_lower_file(ecryptfs_dentry);
279 printk(KERN_ERR "%s: Error attempting to initialize "
280 "the lower file for the dentry with name "
281 "[%s]; rc = [%d]\n", __func__,
282 ecryptfs_dentry->d_name.name, rc);
286 crypt_stat = &ecryptfs_inode_to_private(
287 ecryptfs_dentry->d_inode)->crypt_stat;
288 /* TODO: lock for crypt_stat comparison */
289 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
290 ecryptfs_set_default_sizes(crypt_stat);
291 rc = ecryptfs_read_and_validate_header_region(page_virt,
292 ecryptfs_dentry->d_inode);
294 memset(page_virt, 0, PAGE_CACHE_SIZE);
295 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
301 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
303 ecryptfs_i_size_init(page_virt, ecryptfs_dentry->d_inode);
305 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
310 d_drop(ecryptfs_dentry);
313 ecryptfs_put_lower_file(ecryptfs_dentry->d_inode);
319 * @ecryptfs_dir_inode: The eCryptfs directory inode
320 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
321 * @ecryptfs_nd: nameidata; may be NULL
323 * Find a file on disk. If the file does not exist, then we'll add it to the
324 * dentry cache and continue on to read it from the disk.
326 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
327 struct dentry *ecryptfs_dentry,
328 struct nameidata *ecryptfs_nd)
330 char *encrypted_and_encoded_name = NULL;
331 size_t encrypted_and_encoded_name_size;
332 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
333 struct dentry *lower_dir_dentry, *lower_dentry;
336 if ((ecryptfs_dentry->d_name.len == 1
337 && !strcmp(ecryptfs_dentry->d_name.name, "."))
338 || (ecryptfs_dentry->d_name.len == 2
339 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
342 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
343 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
344 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
346 ecryptfs_dentry->d_name.len);
347 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
348 if (IS_ERR(lower_dentry)) {
349 rc = PTR_ERR(lower_dentry);
350 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
351 "[%d] on lower_dentry = [%s]\n", __func__, rc,
352 encrypted_and_encoded_name);
355 if (lower_dentry->d_inode)
356 goto lookup_and_interpose;
357 mount_crypt_stat = &ecryptfs_superblock_to_private(
358 ecryptfs_dentry->d_sb)->mount_crypt_stat;
359 if (!(mount_crypt_stat
360 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
361 goto lookup_and_interpose;
363 rc = ecryptfs_encrypt_and_encode_filename(
364 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
365 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
366 ecryptfs_dentry->d_name.len);
368 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
369 "filename; rc = [%d]\n", __func__, rc);
372 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
373 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
375 encrypted_and_encoded_name_size);
376 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
377 if (IS_ERR(lower_dentry)) {
378 rc = PTR_ERR(lower_dentry);
379 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
380 "[%d] on lower_dentry = [%s]\n", __func__, rc,
381 encrypted_and_encoded_name);
384 lookup_and_interpose:
385 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
389 d_drop(ecryptfs_dentry);
391 kfree(encrypted_and_encoded_name);
395 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
396 struct dentry *new_dentry)
398 struct dentry *lower_old_dentry;
399 struct dentry *lower_new_dentry;
400 struct dentry *lower_dir_dentry;
404 file_size_save = i_size_read(old_dentry->d_inode);
405 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
406 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
407 dget(lower_old_dentry);
408 dget(lower_new_dentry);
409 lower_dir_dentry = lock_parent(lower_new_dentry);
410 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
412 if (rc || !lower_new_dentry->d_inode)
414 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
417 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
418 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
419 old_dentry->d_inode->i_nlink =
420 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
421 i_size_write(new_dentry->d_inode, file_size_save);
423 unlock_dir(lower_dir_dentry);
424 dput(lower_new_dentry);
425 dput(lower_old_dentry);
429 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
432 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
433 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
434 struct dentry *lower_dir_dentry;
437 lower_dir_dentry = lock_parent(lower_dentry);
438 rc = vfs_unlink(lower_dir_inode, lower_dentry);
440 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
443 fsstack_copy_attr_times(dir, lower_dir_inode);
444 dentry->d_inode->i_nlink =
445 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
446 dentry->d_inode->i_ctime = dir->i_ctime;
449 unlock_dir(lower_dir_dentry);
454 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
458 struct dentry *lower_dentry;
459 struct dentry *lower_dir_dentry;
460 char *encoded_symname;
461 size_t encoded_symlen;
462 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
464 lower_dentry = ecryptfs_dentry_to_lower(dentry);
466 lower_dir_dentry = lock_parent(lower_dentry);
467 mount_crypt_stat = &ecryptfs_superblock_to_private(
468 dir->i_sb)->mount_crypt_stat;
469 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
472 mount_crypt_stat, symname,
476 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
478 kfree(encoded_symname);
479 if (rc || !lower_dentry->d_inode)
481 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
484 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
485 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
487 unlock_dir(lower_dir_dentry);
489 if (!dentry->d_inode)
494 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
497 struct dentry *lower_dentry;
498 struct dentry *lower_dir_dentry;
500 lower_dentry = ecryptfs_dentry_to_lower(dentry);
501 lower_dir_dentry = lock_parent(lower_dentry);
502 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
503 if (rc || !lower_dentry->d_inode)
505 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
508 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
509 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
510 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
512 unlock_dir(lower_dir_dentry);
513 if (!dentry->d_inode)
518 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
520 struct dentry *lower_dentry;
521 struct dentry *lower_dir_dentry;
524 dentry_unhash(dentry);
526 lower_dentry = ecryptfs_dentry_to_lower(dentry);
528 lower_dir_dentry = lock_parent(lower_dentry);
530 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
532 if (!rc && dentry->d_inode)
533 clear_nlink(dentry->d_inode);
534 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
535 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
536 unlock_dir(lower_dir_dentry);
544 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
547 struct dentry *lower_dentry;
548 struct dentry *lower_dir_dentry;
550 lower_dentry = ecryptfs_dentry_to_lower(dentry);
551 lower_dir_dentry = lock_parent(lower_dentry);
552 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
553 if (rc || !lower_dentry->d_inode)
555 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
558 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
559 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
561 unlock_dir(lower_dir_dentry);
562 if (!dentry->d_inode)
568 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
569 struct inode *new_dir, struct dentry *new_dentry)
572 struct dentry *lower_old_dentry;
573 struct dentry *lower_new_dentry;
574 struct dentry *lower_old_dir_dentry;
575 struct dentry *lower_new_dir_dentry;
576 struct dentry *trap = NULL;
578 if (new_dentry->d_inode && S_ISDIR(new_dentry->d_inode->i_mode))
579 dentry_unhash(new_dentry);
581 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
582 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
583 dget(lower_old_dentry);
584 dget(lower_new_dentry);
585 lower_old_dir_dentry = dget_parent(lower_old_dentry);
586 lower_new_dir_dentry = dget_parent(lower_new_dentry);
587 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
588 /* source should not be ancestor of target */
589 if (trap == lower_old_dentry) {
593 /* target should not be ancestor of source */
594 if (trap == lower_new_dentry) {
598 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
599 lower_new_dir_dentry->d_inode, lower_new_dentry);
602 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
603 if (new_dir != old_dir)
604 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
606 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
607 dput(lower_new_dir_dentry);
608 dput(lower_old_dir_dentry);
609 dput(lower_new_dentry);
610 dput(lower_old_dentry);
614 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
617 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
619 size_t lower_bufsiz = PATH_MAX;
623 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
630 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
631 (char __user *)lower_buf,
637 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
638 lower_buf, lower_bufsiz);
645 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
648 size_t kbufsiz, copied;
651 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
654 copied = min_t(size_t, bufsiz, kbufsiz);
655 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
657 fsstack_copy_attr_atime(dentry->d_inode,
658 ecryptfs_dentry_to_lower(dentry)->d_inode);
663 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
666 int len = PAGE_SIZE, rc;
669 /* Released in ecryptfs_put_link(); only release here on error */
670 buf = kmalloc(len, GFP_KERNEL);
672 buf = ERR_PTR(-ENOMEM);
677 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
685 nd_set_link(nd, buf);
690 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
692 char *buf = nd_get_link(nd);
700 * upper_size_to_lower_size
701 * @crypt_stat: Crypt_stat associated with file
702 * @upper_size: Size of the upper file
704 * Calculate the required size of the lower file based on the
705 * specified size of the upper file. This calculation is based on the
706 * number of headers in the underlying file and the extent size.
708 * Returns Calculated size of the lower file.
711 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
716 lower_size = ecryptfs_lower_header_size(crypt_stat);
717 if (upper_size != 0) {
720 num_extents = upper_size >> crypt_stat->extent_shift;
721 if (upper_size & ~crypt_stat->extent_mask)
723 lower_size += (num_extents * crypt_stat->extent_size);
730 * @dentry: The ecryptfs layer dentry
731 * @ia: Address of the ecryptfs inode's attributes
732 * @lower_ia: Address of the lower inode's attributes
734 * Function to handle truncations modifying the size of the file. Note
735 * that the file sizes are interpolated. When expanding, we are simply
736 * writing strings of 0's out. When truncating, we truncate the upper
737 * inode and update the lower_ia according to the page index
738 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
739 * the caller must use lower_ia in a call to notify_change() to perform
740 * the truncation of the lower inode.
742 * Returns zero on success; non-zero otherwise
744 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
745 struct iattr *lower_ia)
748 struct inode *inode = dentry->d_inode;
749 struct ecryptfs_crypt_stat *crypt_stat;
750 loff_t i_size = i_size_read(inode);
751 loff_t lower_size_before_truncate;
752 loff_t lower_size_after_truncate;
754 if (unlikely((ia->ia_size == i_size))) {
755 lower_ia->ia_valid &= ~ATTR_SIZE;
758 rc = ecryptfs_get_lower_file(dentry);
761 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
762 /* Switch on growing or shrinking file */
763 if (ia->ia_size > i_size) {
764 char zero[] = { 0x00 };
766 lower_ia->ia_valid &= ~ATTR_SIZE;
767 /* Write a single 0 at the last position of the file;
768 * this triggers code that will fill in 0's throughout
769 * the intermediate portion of the previous end of the
770 * file and the new and of the file */
771 rc = ecryptfs_write(inode, zero,
772 (ia->ia_size - 1), 1);
773 } else { /* ia->ia_size < i_size_read(inode) */
774 /* We're chopping off all the pages down to the page
775 * in which ia->ia_size is located. Fill in the end of
776 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
777 * PAGE_CACHE_SIZE with zeros. */
778 size_t num_zeros = (PAGE_CACHE_SIZE
779 - (ia->ia_size & ~PAGE_CACHE_MASK));
783 * XXX(truncate) this should really happen at the begginning
784 * of ->setattr. But the code is too messy to that as part
785 * of a larger patch. ecryptfs is also totally missing out
786 * on the inode_change_ok check at the beginning of
787 * ->setattr while would include this.
789 rc = inode_newsize_ok(inode, ia->ia_size);
793 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
794 truncate_setsize(inode, ia->ia_size);
795 lower_ia->ia_size = ia->ia_size;
796 lower_ia->ia_valid |= ATTR_SIZE;
802 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
807 rc = ecryptfs_write(inode, zeros_virt,
808 ia->ia_size, num_zeros);
811 printk(KERN_ERR "Error attempting to zero out "
812 "the remainder of the end page on "
813 "reducing truncate; rc = [%d]\n", rc);
817 truncate_setsize(inode, ia->ia_size);
818 rc = ecryptfs_write_inode_size_to_metadata(inode);
820 printk(KERN_ERR "Problem with "
821 "ecryptfs_write_inode_size_to_metadata; "
825 /* We are reducing the size of the ecryptfs file, and need to
826 * know if we need to reduce the size of the lower file. */
827 lower_size_before_truncate =
828 upper_size_to_lower_size(crypt_stat, i_size);
829 lower_size_after_truncate =
830 upper_size_to_lower_size(crypt_stat, ia->ia_size);
831 if (lower_size_after_truncate < lower_size_before_truncate) {
832 lower_ia->ia_size = lower_size_after_truncate;
833 lower_ia->ia_valid |= ATTR_SIZE;
835 lower_ia->ia_valid &= ~ATTR_SIZE;
838 ecryptfs_put_lower_file(inode);
844 * @dentry: The ecryptfs layer dentry
845 * @new_length: The length to expand the file to
847 * Simple function that handles the truncation of an eCryptfs inode and
848 * its corresponding lower inode.
850 * Returns zero on success; non-zero otherwise
852 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
854 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
855 struct iattr lower_ia = { .ia_valid = 0 };
858 rc = truncate_upper(dentry, &ia, &lower_ia);
859 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
860 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
862 mutex_lock(&lower_dentry->d_inode->i_mutex);
863 rc = notify_change(lower_dentry, &lower_ia);
864 mutex_unlock(&lower_dentry->d_inode->i_mutex);
870 ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
872 if (flags & IPERM_FLAG_RCU)
874 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
879 * @dentry: dentry handle to the inode to modify
880 * @ia: Structure with flags of what to change and values
882 * Updates the metadata of an inode. If the update is to the size
883 * i.e. truncation, then ecryptfs_truncate will handle the size modification
884 * of both the ecryptfs inode and the lower inode.
886 * All other metadata changes will be passed right to the lower filesystem,
887 * and we will just update our inode to look like the lower.
889 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
892 struct dentry *lower_dentry;
893 struct iattr lower_ia;
895 struct inode *lower_inode;
896 struct ecryptfs_crypt_stat *crypt_stat;
898 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
899 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
900 ecryptfs_init_crypt_stat(crypt_stat);
901 inode = dentry->d_inode;
902 lower_inode = ecryptfs_inode_to_lower(inode);
903 lower_dentry = ecryptfs_dentry_to_lower(dentry);
904 mutex_lock(&crypt_stat->cs_mutex);
905 if (S_ISDIR(dentry->d_inode->i_mode))
906 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
907 else if (S_ISREG(dentry->d_inode->i_mode)
908 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
909 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
910 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
912 mount_crypt_stat = &ecryptfs_superblock_to_private(
913 dentry->d_sb)->mount_crypt_stat;
914 rc = ecryptfs_get_lower_file(dentry);
916 mutex_unlock(&crypt_stat->cs_mutex);
919 rc = ecryptfs_read_metadata(dentry);
920 ecryptfs_put_lower_file(inode);
922 if (!(mount_crypt_stat->flags
923 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
925 printk(KERN_WARNING "Either the lower file "
926 "is not in a valid eCryptfs format, "
927 "or the key could not be retrieved. "
928 "Plaintext passthrough mode is not "
929 "enabled; returning -EIO\n");
930 mutex_unlock(&crypt_stat->cs_mutex);
934 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
935 | ECRYPTFS_ENCRYPTED);
938 mutex_unlock(&crypt_stat->cs_mutex);
939 if (S_ISREG(inode->i_mode)) {
940 rc = filemap_write_and_wait(inode->i_mapping);
943 fsstack_copy_attr_all(inode, lower_inode);
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);
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);
965 fsstack_copy_attr_all(inode, lower_inode);
969 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
972 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
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) {
982 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
985 stat->size = targetsiz;
991 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
994 struct kstat lower_stat;
997 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
998 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1000 fsstack_copy_attr_all(dentry->d_inode,
1001 ecryptfs_inode_to_lower(dentry->d_inode));
1002 generic_fillattr(dentry->d_inode, stat);
1003 stat->blocks = lower_stat.blocks;
1009 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1010 size_t size, int flags)
1013 struct dentry *lower_dentry;
1015 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1016 if (!lower_dentry->d_inode->i_op->setxattr) {
1021 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1027 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1028 void *value, size_t size)
1032 if (!lower_dentry->d_inode->i_op->getxattr) {
1036 mutex_lock(&lower_dentry->d_inode->i_mutex);
1037 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1039 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1045 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1048 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1053 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1056 struct dentry *lower_dentry;
1058 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1059 if (!lower_dentry->d_inode->i_op->listxattr) {
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);
1070 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1073 struct dentry *lower_dentry;
1075 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1076 if (!lower_dentry->d_inode->i_op->removexattr) {
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);
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))
1096 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1098 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
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