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);
146 static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
149 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
150 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
151 struct dentry *lower_dir_dentry;
155 lower_dir_dentry = lock_parent(lower_dentry);
156 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
158 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
161 fsstack_copy_attr_times(dir, lower_dir_inode);
162 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
163 inode->i_ctime = dir->i_ctime;
166 unlock_dir(lower_dir_dentry);
173 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
174 * @ecryptfs_dentry: New file's dentry in ecryptfs
175 * @mode: The mode of the new file
176 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
178 * Creates the underlying file and the eCryptfs inode which will link to
179 * it. It will also update the eCryptfs directory inode to mimic the
180 * stat of the lower directory inode.
182 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
184 static struct inode *
185 ecryptfs_do_create(struct inode *directory_inode,
186 struct dentry *ecryptfs_dentry, umode_t mode)
189 struct dentry *lower_dentry;
190 struct dentry *lower_dir_dentry;
193 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
194 lower_dir_dentry = lock_parent(lower_dentry);
195 if (IS_ERR(lower_dir_dentry)) {
196 ecryptfs_printk(KERN_ERR, "Error locking directory of "
198 inode = ERR_CAST(lower_dir_dentry);
201 rc = vfs_create(lower_dir_dentry->d_inode, lower_dentry, mode, true);
203 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
204 "rc = [%d]\n", __func__, rc);
208 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
209 directory_inode->i_sb);
211 vfs_unlink(lower_dir_dentry->d_inode, lower_dentry, NULL);
214 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
215 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
217 unlock_dir(lower_dir_dentry);
223 * ecryptfs_initialize_file
225 * Cause the file to be changed from a basic empty file to an ecryptfs
226 * file with a header and first data page.
228 * Returns zero on success
230 int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
231 struct inode *ecryptfs_inode)
233 struct ecryptfs_crypt_stat *crypt_stat =
234 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
237 if (S_ISDIR(ecryptfs_inode->i_mode)) {
238 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
239 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
242 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
243 rc = ecryptfs_new_file_context(ecryptfs_inode);
245 ecryptfs_printk(KERN_ERR, "Error creating new file "
246 "context; rc = [%d]\n", rc);
249 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
251 printk(KERN_ERR "%s: Error attempting to initialize "
252 "the lower file for the dentry with name "
253 "[%s]; rc = [%d]\n", __func__,
254 ecryptfs_dentry->d_name.name, rc);
257 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
259 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
260 ecryptfs_put_lower_file(ecryptfs_inode);
267 * @dir: The inode of the directory in which to create the file.
268 * @dentry: The eCryptfs dentry
269 * @mode: The mode of the new file.
271 * Creates a new file.
273 * Returns zero on success; non-zero on error condition
276 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
277 umode_t mode, bool excl)
279 struct inode *ecryptfs_inode;
282 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
284 if (unlikely(IS_ERR(ecryptfs_inode))) {
285 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
286 "lower filesystem\n");
287 rc = PTR_ERR(ecryptfs_inode);
290 /* At this point, a file exists on "disk"; we need to make sure
291 * that this on disk file is prepared to be an ecryptfs file */
292 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
294 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
296 make_bad_inode(ecryptfs_inode);
297 unlock_new_inode(ecryptfs_inode);
298 iput(ecryptfs_inode);
301 unlock_new_inode(ecryptfs_inode);
302 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
307 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
309 struct ecryptfs_crypt_stat *crypt_stat;
312 rc = ecryptfs_get_lower_file(dentry, inode);
314 printk(KERN_ERR "%s: Error attempting to initialize "
315 "the lower file for the dentry with name "
316 "[%s]; rc = [%d]\n", __func__,
317 dentry->d_name.name, rc);
321 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
322 /* TODO: lock for crypt_stat comparison */
323 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
324 ecryptfs_set_default_sizes(crypt_stat);
326 rc = ecryptfs_read_and_validate_header_region(inode);
327 ecryptfs_put_lower_file(inode);
329 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
331 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
334 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
339 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
341 static int ecryptfs_lookup_interpose(struct dentry *dentry,
342 struct dentry *lower_dentry,
343 struct inode *dir_inode)
345 struct inode *inode, *lower_inode = lower_dentry->d_inode;
346 struct ecryptfs_dentry_info *dentry_info;
347 struct vfsmount *lower_mnt;
350 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
352 printk(KERN_ERR "%s: Out of memory whilst attempting "
353 "to allocate ecryptfs_dentry_info struct\n",
359 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
360 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
361 BUG_ON(!d_count(lower_dentry));
363 ecryptfs_set_dentry_private(dentry, dentry_info);
364 dentry_info->lower_path.mnt = lower_mnt;
365 dentry_info->lower_path.dentry = lower_dentry;
367 if (!lower_dentry->d_inode) {
368 /* We want to add because we couldn't find in lower */
372 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
374 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
375 __func__, PTR_ERR(inode));
376 return PTR_ERR(inode);
378 if (S_ISREG(inode->i_mode)) {
379 rc = ecryptfs_i_size_read(dentry, inode);
381 make_bad_inode(inode);
386 if (inode->i_state & I_NEW)
387 unlock_new_inode(inode);
388 d_add(dentry, inode);
395 * @ecryptfs_dir_inode: The eCryptfs directory inode
396 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
397 * @ecryptfs_nd: nameidata; may be NULL
399 * Find a file on disk. If the file does not exist, then we'll add it to the
400 * dentry cache and continue on to read it from the disk.
402 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
403 struct dentry *ecryptfs_dentry,
406 char *encrypted_and_encoded_name = NULL;
407 size_t encrypted_and_encoded_name_size;
408 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
409 struct dentry *lower_dir_dentry, *lower_dentry;
412 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
413 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
414 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
416 ecryptfs_dentry->d_name.len);
417 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
418 if (IS_ERR(lower_dentry)) {
419 rc = PTR_ERR(lower_dentry);
420 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
421 "[%d] on lower_dentry = [%s]\n", __func__, rc,
422 ecryptfs_dentry->d_name.name);
425 if (lower_dentry->d_inode)
427 mount_crypt_stat = &ecryptfs_superblock_to_private(
428 ecryptfs_dentry->d_sb)->mount_crypt_stat;
429 if (!(mount_crypt_stat
430 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
433 rc = ecryptfs_encrypt_and_encode_filename(
434 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
435 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
436 ecryptfs_dentry->d_name.len);
438 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
439 "filename; rc = [%d]\n", __func__, rc);
442 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
443 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
445 encrypted_and_encoded_name_size);
446 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
447 if (IS_ERR(lower_dentry)) {
448 rc = PTR_ERR(lower_dentry);
449 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
450 "[%d] on lower_dentry = [%s]\n", __func__, rc,
451 encrypted_and_encoded_name);
455 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
458 kfree(encrypted_and_encoded_name);
462 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
463 struct dentry *new_dentry)
465 struct dentry *lower_old_dentry;
466 struct dentry *lower_new_dentry;
467 struct dentry *lower_dir_dentry;
471 file_size_save = i_size_read(old_dentry->d_inode);
472 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
473 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
474 dget(lower_old_dentry);
475 dget(lower_new_dentry);
476 lower_dir_dentry = lock_parent(lower_new_dentry);
477 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
478 lower_new_dentry, NULL);
479 if (rc || !lower_new_dentry->d_inode)
481 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
484 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
485 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
486 set_nlink(old_dentry->d_inode,
487 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
488 i_size_write(new_dentry->d_inode, file_size_save);
490 unlock_dir(lower_dir_dentry);
491 dput(lower_new_dentry);
492 dput(lower_old_dentry);
496 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
498 return ecryptfs_do_unlink(dir, dentry, dentry->d_inode);
501 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
505 struct dentry *lower_dentry;
506 struct dentry *lower_dir_dentry;
507 char *encoded_symname;
508 size_t encoded_symlen;
509 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
511 lower_dentry = ecryptfs_dentry_to_lower(dentry);
513 lower_dir_dentry = lock_parent(lower_dentry);
514 mount_crypt_stat = &ecryptfs_superblock_to_private(
515 dir->i_sb)->mount_crypt_stat;
516 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
519 mount_crypt_stat, symname,
523 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
525 kfree(encoded_symname);
526 if (rc || !lower_dentry->d_inode)
528 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
531 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
532 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
534 unlock_dir(lower_dir_dentry);
536 if (!dentry->d_inode)
541 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
544 struct dentry *lower_dentry;
545 struct dentry *lower_dir_dentry;
547 lower_dentry = ecryptfs_dentry_to_lower(dentry);
548 lower_dir_dentry = lock_parent(lower_dentry);
549 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
550 if (rc || !lower_dentry->d_inode)
552 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
555 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
556 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
557 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
559 unlock_dir(lower_dir_dentry);
560 if (!dentry->d_inode)
565 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
567 struct dentry *lower_dentry;
568 struct dentry *lower_dir_dentry;
571 lower_dentry = ecryptfs_dentry_to_lower(dentry);
573 lower_dir_dentry = lock_parent(lower_dentry);
575 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
577 if (!rc && dentry->d_inode)
578 clear_nlink(dentry->d_inode);
579 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
580 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
581 unlock_dir(lower_dir_dentry);
589 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
592 struct dentry *lower_dentry;
593 struct dentry *lower_dir_dentry;
595 lower_dentry = ecryptfs_dentry_to_lower(dentry);
596 lower_dir_dentry = lock_parent(lower_dentry);
597 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
598 if (rc || !lower_dentry->d_inode)
600 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
603 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
604 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
606 unlock_dir(lower_dir_dentry);
607 if (!dentry->d_inode)
613 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
614 struct inode *new_dir, struct dentry *new_dentry)
617 struct dentry *lower_old_dentry;
618 struct dentry *lower_new_dentry;
619 struct dentry *lower_old_dir_dentry;
620 struct dentry *lower_new_dir_dentry;
621 struct dentry *trap = NULL;
622 struct inode *target_inode;
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 target_inode = new_dentry->d_inode;
631 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
632 /* source should not be ancestor of target */
633 if (trap == lower_old_dentry) {
637 /* target should not be ancestor of source */
638 if (trap == lower_new_dentry) {
642 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
643 lower_new_dir_dentry->d_inode, lower_new_dentry,
648 fsstack_copy_attr_all(target_inode,
649 ecryptfs_inode_to_lower(target_inode));
650 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
651 if (new_dir != old_dir)
652 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
654 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
655 dput(lower_new_dir_dentry);
656 dput(lower_old_dir_dentry);
657 dput(lower_new_dentry);
658 dput(lower_old_dentry);
662 static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
664 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
670 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
672 return ERR_PTR(-ENOMEM);
675 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
676 (char __user *)lower_buf,
681 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
685 return rc ? ERR_PTR(rc) : buf;
688 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
691 char *buf = ecryptfs_readlink_lower(dentry, &len);
694 fsstack_copy_attr_atime(dentry->d_inode,
695 ecryptfs_dentry_to_lower(dentry)->d_inode);
698 nd_set_link(nd, buf);
703 * upper_size_to_lower_size
704 * @crypt_stat: Crypt_stat associated with file
705 * @upper_size: Size of the upper file
707 * Calculate the required size of the lower file based on the
708 * specified size of the upper file. This calculation is based on the
709 * number of headers in the underlying file and the extent size.
711 * Returns Calculated size of the lower file.
714 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
719 lower_size = ecryptfs_lower_header_size(crypt_stat);
720 if (upper_size != 0) {
723 num_extents = upper_size >> crypt_stat->extent_shift;
724 if (upper_size & ~crypt_stat->extent_mask)
726 lower_size += (num_extents * crypt_stat->extent_size);
733 * @dentry: The ecryptfs layer dentry
734 * @ia: Address of the ecryptfs inode's attributes
735 * @lower_ia: Address of the lower inode's attributes
737 * Function to handle truncations modifying the size of the file. Note
738 * that the file sizes are interpolated. When expanding, we are simply
739 * writing strings of 0's out. When truncating, we truncate the upper
740 * inode and update the lower_ia according to the page index
741 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
742 * the caller must use lower_ia in a call to notify_change() to perform
743 * the truncation of the lower inode.
745 * Returns zero on success; non-zero otherwise
747 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
748 struct iattr *lower_ia)
751 struct inode *inode = dentry->d_inode;
752 struct ecryptfs_crypt_stat *crypt_stat;
753 loff_t i_size = i_size_read(inode);
754 loff_t lower_size_before_truncate;
755 loff_t lower_size_after_truncate;
757 if (unlikely((ia->ia_size == i_size))) {
758 lower_ia->ia_valid &= ~ATTR_SIZE;
761 rc = ecryptfs_get_lower_file(dentry, inode);
764 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
765 /* Switch on growing or shrinking file */
766 if (ia->ia_size > i_size) {
767 char zero[] = { 0x00 };
769 lower_ia->ia_valid &= ~ATTR_SIZE;
770 /* Write a single 0 at the last position of the file;
771 * this triggers code that will fill in 0's throughout
772 * the intermediate portion of the previous end of the
773 * file and the new and of the file */
774 rc = ecryptfs_write(inode, zero,
775 (ia->ia_size - 1), 1);
776 } else { /* ia->ia_size < i_size_read(inode) */
777 /* We're chopping off all the pages down to the page
778 * in which ia->ia_size is located. Fill in the end of
779 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
780 * PAGE_CACHE_SIZE with zeros. */
781 size_t num_zeros = (PAGE_CACHE_SIZE
782 - (ia->ia_size & ~PAGE_CACHE_MASK));
784 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
785 truncate_setsize(inode, ia->ia_size);
786 lower_ia->ia_size = ia->ia_size;
787 lower_ia->ia_valid |= ATTR_SIZE;
793 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
798 rc = ecryptfs_write(inode, zeros_virt,
799 ia->ia_size, num_zeros);
802 printk(KERN_ERR "Error attempting to zero out "
803 "the remainder of the end page on "
804 "reducing truncate; rc = [%d]\n", rc);
808 truncate_setsize(inode, ia->ia_size);
809 rc = ecryptfs_write_inode_size_to_metadata(inode);
811 printk(KERN_ERR "Problem with "
812 "ecryptfs_write_inode_size_to_metadata; "
816 /* We are reducing the size of the ecryptfs file, and need to
817 * know if we need to reduce the size of the lower file. */
818 lower_size_before_truncate =
819 upper_size_to_lower_size(crypt_stat, i_size);
820 lower_size_after_truncate =
821 upper_size_to_lower_size(crypt_stat, ia->ia_size);
822 if (lower_size_after_truncate < lower_size_before_truncate) {
823 lower_ia->ia_size = lower_size_after_truncate;
824 lower_ia->ia_valid |= ATTR_SIZE;
826 lower_ia->ia_valid &= ~ATTR_SIZE;
829 ecryptfs_put_lower_file(inode);
833 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
835 struct ecryptfs_crypt_stat *crypt_stat;
836 loff_t lower_oldsize, lower_newsize;
838 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
839 lower_oldsize = upper_size_to_lower_size(crypt_stat,
841 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
842 if (lower_newsize > lower_oldsize) {
844 * The eCryptfs inode and the new *lower* size are mixed here
845 * because we may not have the lower i_mutex held and/or it may
846 * not be appropriate to call inode_newsize_ok() with inodes
847 * from other filesystems.
849 return inode_newsize_ok(inode, lower_newsize);
857 * @dentry: The ecryptfs layer dentry
858 * @new_length: The length to expand the file to
860 * Simple function that handles the truncation of an eCryptfs inode and
861 * its corresponding lower inode.
863 * Returns zero on success; non-zero otherwise
865 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
867 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
868 struct iattr lower_ia = { .ia_valid = 0 };
871 rc = ecryptfs_inode_newsize_ok(dentry->d_inode, new_length);
875 rc = truncate_upper(dentry, &ia, &lower_ia);
876 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
877 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
879 mutex_lock(&lower_dentry->d_inode->i_mutex);
880 rc = notify_change(lower_dentry, &lower_ia, NULL);
881 mutex_unlock(&lower_dentry->d_inode->i_mutex);
887 ecryptfs_permission(struct inode *inode, int mask)
889 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
894 * @dentry: dentry handle to the inode to modify
895 * @ia: Structure with flags of what to change and values
897 * Updates the metadata of an inode. If the update is to the size
898 * i.e. truncation, then ecryptfs_truncate will handle the size modification
899 * of both the ecryptfs inode and the lower inode.
901 * All other metadata changes will be passed right to the lower filesystem,
902 * and we will just update our inode to look like the lower.
904 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
907 struct dentry *lower_dentry;
908 struct iattr lower_ia;
910 struct inode *lower_inode;
911 struct ecryptfs_crypt_stat *crypt_stat;
913 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
914 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
915 ecryptfs_init_crypt_stat(crypt_stat);
916 inode = dentry->d_inode;
917 lower_inode = ecryptfs_inode_to_lower(inode);
918 lower_dentry = ecryptfs_dentry_to_lower(dentry);
919 mutex_lock(&crypt_stat->cs_mutex);
920 if (S_ISDIR(dentry->d_inode->i_mode))
921 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
922 else if (S_ISREG(dentry->d_inode->i_mode)
923 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
924 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
925 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
927 mount_crypt_stat = &ecryptfs_superblock_to_private(
928 dentry->d_sb)->mount_crypt_stat;
929 rc = ecryptfs_get_lower_file(dentry, inode);
931 mutex_unlock(&crypt_stat->cs_mutex);
934 rc = ecryptfs_read_metadata(dentry);
935 ecryptfs_put_lower_file(inode);
937 if (!(mount_crypt_stat->flags
938 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
940 printk(KERN_WARNING "Either the lower file "
941 "is not in a valid eCryptfs format, "
942 "or the key could not be retrieved. "
943 "Plaintext passthrough mode is not "
944 "enabled; returning -EIO\n");
945 mutex_unlock(&crypt_stat->cs_mutex);
949 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
950 | ECRYPTFS_ENCRYPTED);
953 mutex_unlock(&crypt_stat->cs_mutex);
955 rc = inode_change_ok(inode, ia);
958 if (ia->ia_valid & ATTR_SIZE) {
959 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
964 memcpy(&lower_ia, ia, sizeof(lower_ia));
965 if (ia->ia_valid & ATTR_FILE)
966 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
967 if (ia->ia_valid & ATTR_SIZE) {
968 rc = truncate_upper(dentry, ia, &lower_ia);
974 * mode change is for clearing setuid/setgid bits. Allow lower fs
975 * to interpret this in its own way.
977 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
978 lower_ia.ia_valid &= ~ATTR_MODE;
980 mutex_lock(&lower_dentry->d_inode->i_mutex);
981 rc = notify_change(lower_dentry, &lower_ia, NULL);
982 mutex_unlock(&lower_dentry->d_inode->i_mutex);
984 fsstack_copy_attr_all(inode, lower_inode);
988 static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
991 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
994 mount_crypt_stat = &ecryptfs_superblock_to_private(
995 dentry->d_sb)->mount_crypt_stat;
996 generic_fillattr(dentry->d_inode, stat);
997 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1001 target = ecryptfs_readlink_lower(dentry, &targetsiz);
1002 if (!IS_ERR(target)) {
1004 stat->size = targetsiz;
1006 rc = PTR_ERR(target);
1012 static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1015 struct kstat lower_stat;
1018 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
1020 fsstack_copy_attr_all(dentry->d_inode,
1021 ecryptfs_inode_to_lower(dentry->d_inode));
1022 generic_fillattr(dentry->d_inode, stat);
1023 stat->blocks = lower_stat.blocks;
1029 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1030 size_t size, int flags)
1033 struct dentry *lower_dentry;
1035 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1036 if (!lower_dentry->d_inode->i_op->setxattr) {
1041 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1043 fsstack_copy_attr_all(dentry->d_inode, lower_dentry->d_inode);
1049 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1050 void *value, size_t size)
1054 if (!lower_dentry->d_inode->i_op->getxattr) {
1058 mutex_lock(&lower_dentry->d_inode->i_mutex);
1059 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1061 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1067 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1070 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1075 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1078 struct dentry *lower_dentry;
1080 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1081 if (!lower_dentry->d_inode->i_op->listxattr) {
1085 mutex_lock(&lower_dentry->d_inode->i_mutex);
1086 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1087 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1092 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1095 struct dentry *lower_dentry;
1097 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1098 if (!lower_dentry->d_inode->i_op->removexattr) {
1102 mutex_lock(&lower_dentry->d_inode->i_mutex);
1103 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1104 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1109 const struct inode_operations ecryptfs_symlink_iops = {
1110 .readlink = generic_readlink,
1111 .follow_link = ecryptfs_follow_link,
1112 .put_link = kfree_put_link,
1113 .permission = ecryptfs_permission,
1114 .setattr = ecryptfs_setattr,
1115 .getattr = ecryptfs_getattr_link,
1116 .setxattr = ecryptfs_setxattr,
1117 .getxattr = ecryptfs_getxattr,
1118 .listxattr = ecryptfs_listxattr,
1119 .removexattr = ecryptfs_removexattr
1122 const struct inode_operations ecryptfs_dir_iops = {
1123 .create = ecryptfs_create,
1124 .lookup = ecryptfs_lookup,
1125 .link = ecryptfs_link,
1126 .unlink = ecryptfs_unlink,
1127 .symlink = ecryptfs_symlink,
1128 .mkdir = ecryptfs_mkdir,
1129 .rmdir = ecryptfs_rmdir,
1130 .mknod = ecryptfs_mknod,
1131 .rename = ecryptfs_rename,
1132 .permission = ecryptfs_permission,
1133 .setattr = ecryptfs_setattr,
1134 .setxattr = ecryptfs_setxattr,
1135 .getxattr = ecryptfs_getxattr,
1136 .listxattr = ecryptfs_listxattr,
1137 .removexattr = ecryptfs_removexattr
1140 const struct inode_operations ecryptfs_main_iops = {
1141 .permission = ecryptfs_permission,
1142 .setattr = ecryptfs_setattr,
1143 .getattr = ecryptfs_getattr,
1144 .setxattr = ecryptfs_setxattr,
1145 .getxattr = ecryptfs_getxattr,
1146 .listxattr = ecryptfs_listxattr,
1147 .removexattr = ecryptfs_removexattr