2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry *lock_parent(struct dentry *dentry)
43 dir = dget_parent(dentry);
44 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
48 static void unlock_dir(struct dentry *dir)
50 mutex_unlock(&dir->d_inode->i_mutex);
54 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
56 if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
61 static int ecryptfs_inode_set(struct inode *inode, void *opaque)
63 struct inode *lower_inode = opaque;
65 ecryptfs_set_inode_lower(inode, lower_inode);
66 fsstack_copy_attr_all(inode, lower_inode);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode, lower_inode);
69 inode->i_ino = lower_inode->i_ino;
71 inode->i_mapping->a_ops = &ecryptfs_aops;
72 inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
74 if (S_ISLNK(inode->i_mode))
75 inode->i_op = &ecryptfs_symlink_iops;
76 else if (S_ISDIR(inode->i_mode))
77 inode->i_op = &ecryptfs_dir_iops;
79 inode->i_op = &ecryptfs_main_iops;
81 if (S_ISDIR(inode->i_mode))
82 inode->i_fop = &ecryptfs_dir_fops;
83 else if (special_file(inode->i_mode))
84 init_special_inode(inode, inode->i_mode, inode->i_rdev);
86 inode->i_fop = &ecryptfs_main_fops;
91 static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
92 struct super_block *sb)
96 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
97 return ERR_PTR(-EXDEV);
98 if (!igrab(lower_inode))
99 return ERR_PTR(-ESTALE);
100 inode = iget5_locked(sb, (unsigned long)lower_inode,
101 ecryptfs_inode_test, ecryptfs_inode_set,
105 return ERR_PTR(-EACCES);
107 if (!(inode->i_state & I_NEW))
113 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
114 struct super_block *sb)
116 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
118 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
119 unlock_new_inode(inode);
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
130 * Interposes upper and lower dentries.
132 * Returns zero on success; non-zero otherwise
134 static int ecryptfs_interpose(struct dentry *lower_dentry,
135 struct dentry *dentry, struct super_block *sb)
137 struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
140 return PTR_ERR(inode);
141 d_instantiate(dentry, inode);
148 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
149 * @ecryptfs_dentry: New file's dentry in ecryptfs
150 * @mode: The mode of the new file
151 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
153 * Creates the underlying file and the eCryptfs inode which will link to
154 * it. It will also update the eCryptfs directory inode to mimic the
155 * stat of the lower directory inode.
157 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
159 static struct inode *
160 ecryptfs_do_create(struct inode *directory_inode,
161 struct dentry *ecryptfs_dentry, umode_t mode)
164 struct dentry *lower_dentry;
165 struct dentry *lower_dir_dentry;
168 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
169 lower_dir_dentry = lock_parent(lower_dentry);
170 if (IS_ERR(lower_dir_dentry)) {
171 ecryptfs_printk(KERN_ERR, "Error locking directory of "
173 inode = ERR_CAST(lower_dir_dentry);
176 rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
178 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
179 "rc = [%d]\n", __func__, rc);
183 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
184 directory_inode->i_sb);
187 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
188 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
190 unlock_dir(lower_dir_dentry);
196 * ecryptfs_initialize_file
198 * Cause the file to be changed from a basic empty file to an ecryptfs
199 * file with a header and first data page.
201 * Returns zero on success
203 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
204 struct inode *ecryptfs_inode)
206 struct ecryptfs_crypt_stat *crypt_stat =
207 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
210 if (S_ISDIR(ecryptfs_inode->i_mode)) {
211 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
212 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
215 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
216 rc = ecryptfs_new_file_context(ecryptfs_inode);
218 ecryptfs_printk(KERN_ERR, "Error creating new file "
219 "context; rc = [%d]\n", rc);
222 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
224 printk(KERN_ERR "%s: Error attempting to initialize "
225 "the lower file for the dentry with name "
226 "[%s]; rc = [%d]\n", __func__,
227 ecryptfs_dentry->d_name.name, rc);
230 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
232 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
233 ecryptfs_put_lower_file(ecryptfs_inode);
240 * @dir: The inode of the directory in which to create the file.
241 * @dentry: The eCryptfs dentry
242 * @mode: The mode of the new file.
244 * Creates a new file.
246 * Returns zero on success; non-zero on error condition
249 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
250 umode_t mode, bool excl)
252 struct inode *ecryptfs_inode;
255 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
257 if (unlikely(IS_ERR(ecryptfs_inode))) {
258 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
259 "lower filesystem\n");
260 rc = PTR_ERR(ecryptfs_inode);
263 /* At this point, a file exists on "disk"; we need to make sure
264 * that this on disk file is prepared to be an ecryptfs file */
265 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
267 drop_nlink(ecryptfs_inode);
268 unlock_new_inode(ecryptfs_inode);
269 iput(ecryptfs_inode);
272 unlock_new_inode(ecryptfs_inode);
273 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
278 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
280 struct ecryptfs_crypt_stat *crypt_stat;
283 rc = ecryptfs_get_lower_file(dentry, inode);
285 printk(KERN_ERR "%s: Error attempting to initialize "
286 "the lower file for the dentry with name "
287 "[%s]; rc = [%d]\n", __func__,
288 dentry->d_name.name, rc);
292 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
293 /* TODO: lock for crypt_stat comparison */
294 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
295 ecryptfs_set_default_sizes(crypt_stat);
297 rc = ecryptfs_read_and_validate_header_region(inode);
298 ecryptfs_put_lower_file(inode);
300 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
302 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
305 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
310 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
312 static int ecryptfs_lookup_interpose(struct dentry *dentry,
313 struct dentry *lower_dentry,
314 struct inode *dir_inode)
316 struct inode *inode, *lower_inode = lower_dentry->d_inode;
317 struct ecryptfs_dentry_info *dentry_info;
318 struct vfsmount *lower_mnt;
321 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
322 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
323 BUG_ON(!lower_dentry->d_count);
325 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
326 ecryptfs_set_dentry_private(dentry, dentry_info);
328 printk(KERN_ERR "%s: Out of memory whilst attempting "
329 "to allocate ecryptfs_dentry_info struct\n",
336 ecryptfs_set_dentry_lower(dentry, lower_dentry);
337 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
339 if (!lower_dentry->d_inode) {
340 /* We want to add because we couldn't find in lower */
344 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
346 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
347 __func__, PTR_ERR(inode));
348 return PTR_ERR(inode);
350 if (S_ISREG(inode->i_mode)) {
351 rc = ecryptfs_i_size_read(dentry, inode);
353 make_bad_inode(inode);
358 if (inode->i_state & I_NEW)
359 unlock_new_inode(inode);
360 d_add(dentry, inode);
367 * @ecryptfs_dir_inode: The eCryptfs directory inode
368 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
369 * @ecryptfs_nd: nameidata; may be NULL
371 * Find a file on disk. If the file does not exist, then we'll add it to the
372 * dentry cache and continue on to read it from the disk.
374 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
375 struct dentry *ecryptfs_dentry,
378 char *encrypted_and_encoded_name = NULL;
379 size_t encrypted_and_encoded_name_size;
380 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
381 struct dentry *lower_dir_dentry, *lower_dentry;
384 if ((ecryptfs_dentry->d_name.len == 1
385 && !strcmp(ecryptfs_dentry->d_name.name, "."))
386 || (ecryptfs_dentry->d_name.len == 2
387 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
390 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
391 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
392 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
394 ecryptfs_dentry->d_name.len);
395 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
396 if (IS_ERR(lower_dentry)) {
397 rc = PTR_ERR(lower_dentry);
398 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
399 "[%d] on lower_dentry = [%s]\n", __func__, rc,
400 encrypted_and_encoded_name);
403 if (lower_dentry->d_inode)
405 mount_crypt_stat = &ecryptfs_superblock_to_private(
406 ecryptfs_dentry->d_sb)->mount_crypt_stat;
407 if (!(mount_crypt_stat
408 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
411 rc = ecryptfs_encrypt_and_encode_filename(
412 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
413 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
414 ecryptfs_dentry->d_name.len);
416 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
417 "filename; rc = [%d]\n", __func__, rc);
420 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
421 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
423 encrypted_and_encoded_name_size);
424 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
425 if (IS_ERR(lower_dentry)) {
426 rc = PTR_ERR(lower_dentry);
427 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
428 "[%d] on lower_dentry = [%s]\n", __func__, rc,
429 encrypted_and_encoded_name);
433 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
437 d_drop(ecryptfs_dentry);
439 kfree(encrypted_and_encoded_name);
443 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
444 struct dentry *new_dentry)
446 struct dentry *lower_old_dentry;
447 struct dentry *lower_new_dentry;
448 struct dentry *lower_dir_dentry;
452 file_size_save = i_size_read(old_dentry->d_inode);
453 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
454 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
455 dget(lower_old_dentry);
456 dget(lower_new_dentry);
457 lower_dir_dentry = lock_parent(lower_new_dentry);
458 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
460 if (rc || !lower_new_dentry->d_inode)
462 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
465 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
466 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
467 set_nlink(old_dentry->d_inode,
468 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
469 i_size_write(new_dentry->d_inode, file_size_save);
471 unlock_dir(lower_dir_dentry);
472 dput(lower_new_dentry);
473 dput(lower_old_dentry);
477 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
480 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
481 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
482 struct dentry *lower_dir_dentry;
485 lower_dir_dentry = lock_parent(lower_dentry);
486 rc = vfs_unlink(lower_dir_inode, lower_dentry);
488 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
491 fsstack_copy_attr_times(dir, lower_dir_inode);
492 set_nlink(dentry->d_inode,
493 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink);
494 dentry->d_inode->i_ctime = dir->i_ctime;
497 unlock_dir(lower_dir_dentry);
502 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
506 struct dentry *lower_dentry;
507 struct dentry *lower_dir_dentry;
508 char *encoded_symname;
509 size_t encoded_symlen;
510 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
512 lower_dentry = ecryptfs_dentry_to_lower(dentry);
514 lower_dir_dentry = lock_parent(lower_dentry);
515 mount_crypt_stat = &ecryptfs_superblock_to_private(
516 dir->i_sb)->mount_crypt_stat;
517 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
520 mount_crypt_stat, symname,
524 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
526 kfree(encoded_symname);
527 if (rc || !lower_dentry->d_inode)
529 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
532 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
533 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
535 unlock_dir(lower_dir_dentry);
537 if (!dentry->d_inode)
542 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
545 struct dentry *lower_dentry;
546 struct dentry *lower_dir_dentry;
548 lower_dentry = ecryptfs_dentry_to_lower(dentry);
549 lower_dir_dentry = lock_parent(lower_dentry);
550 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
551 if (rc || !lower_dentry->d_inode)
553 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
556 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
557 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
558 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
560 unlock_dir(lower_dir_dentry);
561 if (!dentry->d_inode)
566 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
568 struct dentry *lower_dentry;
569 struct dentry *lower_dir_dentry;
572 lower_dentry = ecryptfs_dentry_to_lower(dentry);
574 lower_dir_dentry = lock_parent(lower_dentry);
576 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
578 if (!rc && dentry->d_inode)
579 clear_nlink(dentry->d_inode);
580 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
581 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
582 unlock_dir(lower_dir_dentry);
590 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
593 struct dentry *lower_dentry;
594 struct dentry *lower_dir_dentry;
596 lower_dentry = ecryptfs_dentry_to_lower(dentry);
597 lower_dir_dentry = lock_parent(lower_dentry);
598 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
599 if (rc || !lower_dentry->d_inode)
601 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
604 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
605 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
607 unlock_dir(lower_dir_dentry);
608 if (!dentry->d_inode)
614 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
615 struct inode *new_dir, struct dentry *new_dentry)
618 struct dentry *lower_old_dentry;
619 struct dentry *lower_new_dentry;
620 struct dentry *lower_old_dir_dentry;
621 struct dentry *lower_new_dir_dentry;
622 struct dentry *trap = NULL;
624 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
625 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
626 dget(lower_old_dentry);
627 dget(lower_new_dentry);
628 lower_old_dir_dentry = dget_parent(lower_old_dentry);
629 lower_new_dir_dentry = dget_parent(lower_new_dentry);
630 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
631 /* source should not be ancestor of target */
632 if (trap == lower_old_dentry) {
636 /* target should not be ancestor of source */
637 if (trap == lower_new_dentry) {
641 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
642 lower_new_dir_dentry->d_inode, lower_new_dentry);
645 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
646 if (new_dir != old_dir)
647 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
649 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
650 dput(lower_new_dir_dentry);
651 dput(lower_old_dir_dentry);
652 dput(lower_new_dentry);
653 dput(lower_old_dentry);
657 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
660 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
665 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
672 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
673 (char __user *)lower_buf,
678 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
685 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
688 size_t len = PATH_MAX;
691 rc = ecryptfs_readlink_lower(dentry, &buf, &len);
694 fsstack_copy_attr_atime(dentry->d_inode,
695 ecryptfs_dentry_to_lower(dentry)->d_inode);
698 nd_set_link(nd, buf);
703 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
705 char *buf = nd_get_link(nd);
713 * upper_size_to_lower_size
714 * @crypt_stat: Crypt_stat associated with file
715 * @upper_size: Size of the upper file
717 * Calculate the required size of the lower file based on the
718 * specified size of the upper file. This calculation is based on the
719 * number of headers in the underlying file and the extent size.
721 * Returns Calculated size of the lower file.
724 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
729 lower_size = ecryptfs_lower_header_size(crypt_stat);
730 if (upper_size != 0) {
733 num_extents = upper_size >> crypt_stat->extent_shift;
734 if (upper_size & ~crypt_stat->extent_mask)
736 lower_size += (num_extents * crypt_stat->extent_size);
743 * @dentry: The ecryptfs layer dentry
744 * @ia: Address of the ecryptfs inode's attributes
745 * @lower_ia: Address of the lower inode's attributes
747 * Function to handle truncations modifying the size of the file. Note
748 * that the file sizes are interpolated. When expanding, we are simply
749 * writing strings of 0's out. When truncating, we truncate the upper
750 * inode and update the lower_ia according to the page index
751 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
752 * the caller must use lower_ia in a call to notify_change() to perform
753 * the truncation of the lower inode.
755 * Returns zero on success; non-zero otherwise
757 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
758 struct iattr *lower_ia)
761 struct inode *inode = dentry->d_inode;
762 struct ecryptfs_crypt_stat *crypt_stat;
763 loff_t i_size = i_size_read(inode);
764 loff_t lower_size_before_truncate;
765 loff_t lower_size_after_truncate;
767 if (unlikely((ia->ia_size == i_size))) {
768 lower_ia->ia_valid &= ~ATTR_SIZE;
771 rc = ecryptfs_get_lower_file(dentry, inode);
774 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
775 /* Switch on growing or shrinking file */
776 if (ia->ia_size > i_size) {
777 char zero[] = { 0x00 };
779 lower_ia->ia_valid &= ~ATTR_SIZE;
780 /* Write a single 0 at the last position of the file;
781 * this triggers code that will fill in 0's throughout
782 * the intermediate portion of the previous end of the
783 * file and the new and of the file */
784 rc = ecryptfs_write(inode, zero,
785 (ia->ia_size - 1), 1);
786 } else { /* ia->ia_size < i_size_read(inode) */
787 /* We're chopping off all the pages down to the page
788 * in which ia->ia_size is located. Fill in the end of
789 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
790 * PAGE_CACHE_SIZE with zeros. */
791 size_t num_zeros = (PAGE_CACHE_SIZE
792 - (ia->ia_size & ~PAGE_CACHE_MASK));
794 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
795 truncate_setsize(inode, ia->ia_size);
796 lower_ia->ia_size = ia->ia_size;
797 lower_ia->ia_valid |= ATTR_SIZE;
803 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
808 rc = ecryptfs_write(inode, zeros_virt,
809 ia->ia_size, num_zeros);
812 printk(KERN_ERR "Error attempting to zero out "
813 "the remainder of the end page on "
814 "reducing truncate; rc = [%d]\n", rc);
818 truncate_setsize(inode, ia->ia_size);
819 rc = ecryptfs_write_inode_size_to_metadata(inode);
821 printk(KERN_ERR "Problem with "
822 "ecryptfs_write_inode_size_to_metadata; "
826 /* We are reducing the size of the ecryptfs file, and need to
827 * know if we need to reduce the size of the lower file. */
828 lower_size_before_truncate =
829 upper_size_to_lower_size(crypt_stat, i_size);
830 lower_size_after_truncate =
831 upper_size_to_lower_size(crypt_stat, ia->ia_size);
832 if (lower_size_after_truncate < lower_size_before_truncate) {
833 lower_ia->ia_size = lower_size_after_truncate;
834 lower_ia->ia_valid |= ATTR_SIZE;
836 lower_ia->ia_valid &= ~ATTR_SIZE;
839 ecryptfs_put_lower_file(inode);
843 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
845 struct ecryptfs_crypt_stat *crypt_stat;
846 loff_t lower_oldsize, lower_newsize;
848 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
849 lower_oldsize = upper_size_to_lower_size(crypt_stat,
851 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
852 if (lower_newsize > lower_oldsize) {
854 * The eCryptfs inode and the new *lower* size are mixed here
855 * because we may not have the lower i_mutex held and/or it may
856 * not be appropriate to call inode_newsize_ok() with inodes
857 * from other filesystems.
859 return inode_newsize_ok(inode, lower_newsize);
867 * @dentry: The ecryptfs layer dentry
868 * @new_length: The length to expand the file to
870 * Simple function that handles the truncation of an eCryptfs inode and
871 * its corresponding lower inode.
873 * Returns zero on success; non-zero otherwise
875 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
877 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
878 struct iattr lower_ia = { .ia_valid = 0 };
881 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
885 rc = truncate_upper(dentry, &ia, &lower_ia);
886 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
887 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
889 mutex_lock(&lower_dentry->d_inode->i_mutex);
890 rc = notify_change(lower_dentry, &lower_ia);
891 mutex_unlock(&lower_dentry->d_inode->i_mutex);
897 ecryptfs_permission(struct inode *inode, int mask)
899 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
904 * @dentry: dentry handle to the inode to modify
905 * @ia: Structure with flags of what to change and values
907 * Updates the metadata of an inode. If the update is to the size
908 * i.e. truncation, then ecryptfs_truncate will handle the size modification
909 * of both the ecryptfs inode and the lower inode.
911 * All other metadata changes will be passed right to the lower filesystem,
912 * and we will just update our inode to look like the lower.
914 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
917 struct dentry *lower_dentry;
918 struct iattr lower_ia;
920 struct inode *lower_inode;
921 struct ecryptfs_crypt_stat *crypt_stat;
923 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
924 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
925 ecryptfs_init_crypt_stat(crypt_stat);
926 inode = dentry->d_inode;
927 lower_inode = ecryptfs_inode_to_lower(inode);
928 lower_dentry = ecryptfs_dentry_to_lower(dentry);
929 mutex_lock(&crypt_stat->cs_mutex);
930 if (S_ISDIR(dentry->d_inode->i_mode))
931 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
932 else if (S_ISREG(dentry->d_inode->i_mode)
933 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
934 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
935 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
937 mount_crypt_stat = &ecryptfs_superblock_to_private(
938 dentry->d_sb)->mount_crypt_stat;
939 rc = ecryptfs_get_lower_file(dentry, inode);
941 mutex_unlock(&crypt_stat->cs_mutex);
944 rc = ecryptfs_read_metadata(dentry);
945 ecryptfs_put_lower_file(inode);
947 if (!(mount_crypt_stat->flags
948 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
950 printk(KERN_WARNING "Either the lower file "
951 "is not in a valid eCryptfs format, "
952 "or the key could not be retrieved. "
953 "Plaintext passthrough mode is not "
954 "enabled; returning -EIO\n");
955 mutex_unlock(&crypt_stat->cs_mutex);
959 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
960 | ECRYPTFS_ENCRYPTED);
963 mutex_unlock(&crypt_stat->cs_mutex);
965 rc = inode_change_ok(inode, ia);
968 if (ia->ia_valid & ATTR_SIZE) {
969 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
974 if (S_ISREG(inode->i_mode)) {
975 rc = filemap_write_and_wait(inode->i_mapping);
978 fsstack_copy_attr_all(inode, lower_inode);
980 memcpy(&lower_ia, ia, sizeof(lower_ia));
981 if (ia->ia_valid & ATTR_FILE)
982 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
983 if (ia->ia_valid & ATTR_SIZE) {
984 rc = truncate_upper(dentry, ia, &lower_ia);
990 * mode change is for clearing setuid/setgid bits. Allow lower fs
991 * to interpret this in its own way.
993 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
994 lower_ia.ia_valid &= ~ATTR_MODE;
996 mutex_lock(&lower_dentry->d_inode->i_mutex);
997 rc = notify_change(lower_dentry, &lower_ia);
998 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1000 fsstack_copy_attr_all(inode, lower_inode);
1004 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1007 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1010 mount_crypt_stat = &ecryptfs_superblock_to_private(
1011 dentry->d_sb)->mount_crypt_stat;
1012 generic_fillattr(dentry->d_inode, stat);
1013 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1017 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1020 stat->size = targetsiz;
1026 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1029 struct kstat lower_stat;
1032 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1033 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1035 fsstack_copy_attr_all(dentry->d_inode,
1036 ecryptfs_inode_to_lower(dentry->d_inode));
1037 generic_fillattr(dentry->d_inode, stat);
1038 stat->blocks = lower_stat.blocks;
1044 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1045 size_t size, int flags)
1048 struct dentry *lower_dentry;
1050 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1051 if (!lower_dentry->d_inode->i_op->setxattr) {
1056 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1058 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
1064 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1065 void *value, size_t size)
1069 if (!lower_dentry->d_inode->i_op->getxattr) {
1073 mutex_lock(&lower_dentry->d_inode->i_mutex);
1074 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1076 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1082 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1085 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1090 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1093 struct dentry *lower_dentry;
1095 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1096 if (!lower_dentry->d_inode->i_op->listxattr) {
1100 mutex_lock(&lower_dentry->d_inode->i_mutex);
1101 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1102 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1107 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1110 struct dentry *lower_dentry;
1112 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1113 if (!lower_dentry->d_inode->i_op->removexattr) {
1117 mutex_lock(&lower_dentry->d_inode->i_mutex);
1118 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1119 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1124 const struct inode_operations ecryptfs_symlink_iops = {
1125 .readlink = generic_readlink,
1126 .follow_link = ecryptfs_follow_link,
1127 .put_link = ecryptfs_put_link,
1128 .permission = ecryptfs_permission,
1129 .setattr = ecryptfs_setattr,
1130 .getattr = ecryptfs_getattr_link,
1131 .setxattr = ecryptfs_setxattr,
1132 .getxattr = ecryptfs_getxattr,
1133 .listxattr = ecryptfs_listxattr,
1134 .removexattr = ecryptfs_removexattr
1137 const struct inode_operations ecryptfs_dir_iops = {
1138 .create = ecryptfs_create,
1139 .lookup = ecryptfs_lookup,
1140 .link = ecryptfs_link,
1141 .unlink = ecryptfs_unlink,
1142 .symlink = ecryptfs_symlink,
1143 .mkdir = ecryptfs_mkdir,
1144 .rmdir = ecryptfs_rmdir,
1145 .mknod = ecryptfs_mknod,
1146 .rename = ecryptfs_rename,
1147 .permission = ecryptfs_permission,
1148 .setattr = ecryptfs_setattr,
1149 .setxattr = ecryptfs_setxattr,
1150 .getxattr = ecryptfs_getxattr,
1151 .listxattr = ecryptfs_listxattr,
1152 .removexattr = ecryptfs_removexattr
1155 const struct inode_operations ecryptfs_main_iops = {
1156 .permission = ecryptfs_permission,
1157 .setattr = ecryptfs_setattr,
1158 .getattr = ecryptfs_getattr,
1159 .setxattr = ecryptfs_setxattr,
1160 .getxattr = ecryptfs_getxattr,
1161 .listxattr = ecryptfs_listxattr,
1162 .removexattr = ecryptfs_removexattr