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/fs_stack.h>
33 #include <linux/slab.h>
34 #include <linux/xattr.h>
35 #include <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry *lock_parent(struct dentry *dentry)
42 dir = dget_parent(dentry);
43 inode_lock_nested(d_inode(dir), I_MUTEX_PARENT);
47 static void unlock_dir(struct dentry *dir)
49 inode_unlock(d_inode(dir));
53 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
55 return ecryptfs_inode_to_lower(inode) == lower_inode;
58 static int ecryptfs_inode_set(struct inode *inode, void *opaque)
60 struct inode *lower_inode = opaque;
62 ecryptfs_set_inode_lower(inode, lower_inode);
63 fsstack_copy_attr_all(inode, lower_inode);
64 /* i_size will be overwritten for encrypted regular files */
65 fsstack_copy_inode_size(inode, lower_inode);
66 inode->i_ino = lower_inode->i_ino;
68 inode->i_mapping->a_ops = &ecryptfs_aops;
70 if (S_ISLNK(inode->i_mode))
71 inode->i_op = &ecryptfs_symlink_iops;
72 else if (S_ISDIR(inode->i_mode))
73 inode->i_op = &ecryptfs_dir_iops;
75 inode->i_op = &ecryptfs_main_iops;
77 if (S_ISDIR(inode->i_mode))
78 inode->i_fop = &ecryptfs_dir_fops;
79 else if (special_file(inode->i_mode))
80 init_special_inode(inode, inode->i_mode, inode->i_rdev);
82 inode->i_fop = &ecryptfs_main_fops;
87 static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
88 struct super_block *sb)
92 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
93 return ERR_PTR(-EXDEV);
94 if (!igrab(lower_inode))
95 return ERR_PTR(-ESTALE);
96 inode = iget5_locked(sb, (unsigned long)lower_inode,
97 ecryptfs_inode_test, ecryptfs_inode_set,
101 return ERR_PTR(-EACCES);
103 if (!(inode->i_state & I_NEW))
109 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
110 struct super_block *sb)
112 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
114 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
115 unlock_new_inode(inode);
122 * @lower_dentry: Existing dentry in the lower filesystem
123 * @dentry: ecryptfs' dentry
124 * @sb: ecryptfs's super_block
126 * Interposes upper and lower dentries.
128 * Returns zero on success; non-zero otherwise
130 static int ecryptfs_interpose(struct dentry *lower_dentry,
131 struct dentry *dentry, struct super_block *sb)
133 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
136 return PTR_ERR(inode);
137 d_instantiate(dentry, inode);
142 static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
145 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
146 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
147 struct dentry *lower_dir_dentry;
151 lower_dir_dentry = lock_parent(lower_dentry);
152 rc = vfs_unlink(lower_dir_inode, lower_dentry, NULL);
154 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
157 fsstack_copy_attr_times(dir, lower_dir_inode);
158 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
159 inode->i_ctime = dir->i_ctime;
162 unlock_dir(lower_dir_dentry);
169 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
170 * @ecryptfs_dentry: New file's dentry in ecryptfs
171 * @mode: The mode of the new file
173 * Creates the underlying file and the eCryptfs inode which will link to
174 * it. It will also update the eCryptfs directory inode to mimic the
175 * stat of the lower directory inode.
177 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
179 static struct inode *
180 ecryptfs_do_create(struct inode *directory_inode,
181 struct dentry *ecryptfs_dentry, umode_t mode)
184 struct dentry *lower_dentry;
185 struct dentry *lower_dir_dentry;
188 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
189 lower_dir_dentry = lock_parent(lower_dentry);
190 rc = vfs_create(d_inode(lower_dir_dentry), lower_dentry, mode, true);
192 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
193 "rc = [%d]\n", __func__, rc);
197 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
198 directory_inode->i_sb);
200 vfs_unlink(d_inode(lower_dir_dentry), lower_dentry, NULL);
203 fsstack_copy_attr_times(directory_inode, d_inode(lower_dir_dentry));
204 fsstack_copy_inode_size(directory_inode, d_inode(lower_dir_dentry));
206 unlock_dir(lower_dir_dentry);
211 * ecryptfs_initialize_file
213 * Cause the file to be changed from a basic empty file to an ecryptfs
214 * file with a header and first data page.
216 * Returns zero on success
218 int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
219 struct inode *ecryptfs_inode)
221 struct ecryptfs_crypt_stat *crypt_stat =
222 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
225 if (S_ISDIR(ecryptfs_inode->i_mode)) {
226 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
227 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
230 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
231 rc = ecryptfs_new_file_context(ecryptfs_inode);
233 ecryptfs_printk(KERN_ERR, "Error creating new file "
234 "context; rc = [%d]\n", rc);
237 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
239 printk(KERN_ERR "%s: Error attempting to initialize "
240 "the lower file for the dentry with name "
241 "[%pd]; rc = [%d]\n", __func__,
242 ecryptfs_dentry, rc);
245 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
247 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
248 ecryptfs_put_lower_file(ecryptfs_inode);
255 * @dir: The inode of the directory in which to create the file.
256 * @dentry: The eCryptfs dentry
257 * @mode: The mode of the new file.
259 * Creates a new file.
261 * Returns zero on success; non-zero on error condition
264 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
265 umode_t mode, bool excl)
267 struct inode *ecryptfs_inode;
270 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
272 if (IS_ERR(ecryptfs_inode)) {
273 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
274 "lower filesystem\n");
275 rc = PTR_ERR(ecryptfs_inode);
278 /* At this point, a file exists on "disk"; we need to make sure
279 * that this on disk file is prepared to be an ecryptfs file */
280 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
282 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
284 iget_failed(ecryptfs_inode);
287 unlock_new_inode(ecryptfs_inode);
288 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
293 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
295 struct ecryptfs_crypt_stat *crypt_stat;
298 rc = ecryptfs_get_lower_file(dentry, inode);
300 printk(KERN_ERR "%s: Error attempting to initialize "
301 "the lower file for the dentry with name "
302 "[%pd]; rc = [%d]\n", __func__,
307 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
308 /* TODO: lock for crypt_stat comparison */
309 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
310 ecryptfs_set_default_sizes(crypt_stat);
312 rc = ecryptfs_read_and_validate_header_region(inode);
313 ecryptfs_put_lower_file(inode);
315 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
317 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
320 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
325 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
327 static int ecryptfs_lookup_interpose(struct dentry *dentry,
328 struct dentry *lower_dentry,
329 struct inode *dir_inode)
331 struct inode *inode, *lower_inode = d_inode(lower_dentry);
332 struct ecryptfs_dentry_info *dentry_info;
333 struct vfsmount *lower_mnt;
336 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
338 printk(KERN_ERR "%s: Out of memory whilst attempting "
339 "to allocate ecryptfs_dentry_info struct\n",
345 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
346 fsstack_copy_attr_atime(dir_inode, d_inode(lower_dentry->d_parent));
347 BUG_ON(!d_count(lower_dentry));
349 ecryptfs_set_dentry_private(dentry, dentry_info);
350 dentry_info->lower_path.mnt = lower_mnt;
351 dentry_info->lower_path.dentry = lower_dentry;
353 if (d_really_is_negative(lower_dentry)) {
354 /* We want to add because we couldn't find in lower */
358 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
360 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
361 __func__, PTR_ERR(inode));
362 return PTR_ERR(inode);
364 if (S_ISREG(inode->i_mode)) {
365 rc = ecryptfs_i_size_read(dentry, inode);
367 make_bad_inode(inode);
372 if (inode->i_state & I_NEW)
373 unlock_new_inode(inode);
374 d_add(dentry, inode);
381 * @ecryptfs_dir_inode: The eCryptfs directory inode
382 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
383 * @flags: lookup flags
385 * Find a file on disk. If the file does not exist, then we'll add it to the
386 * dentry cache and continue on to read it from the disk.
388 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
389 struct dentry *ecryptfs_dentry,
392 char *encrypted_and_encoded_name = NULL;
393 size_t encrypted_and_encoded_name_size;
394 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
395 struct dentry *lower_dir_dentry, *lower_dentry;
398 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
399 inode_lock(d_inode(lower_dir_dentry));
400 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
402 ecryptfs_dentry->d_name.len);
403 inode_unlock(d_inode(lower_dir_dentry));
404 if (IS_ERR(lower_dentry)) {
405 rc = PTR_ERR(lower_dentry);
406 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
407 "[%d] on lower_dentry = [%pd]\n", __func__, rc,
411 if (d_really_is_positive(lower_dentry))
413 mount_crypt_stat = &ecryptfs_superblock_to_private(
414 ecryptfs_dentry->d_sb)->mount_crypt_stat;
415 if (!(mount_crypt_stat
416 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
419 rc = ecryptfs_encrypt_and_encode_filename(
420 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
421 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
422 ecryptfs_dentry->d_name.len);
424 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
425 "filename; rc = [%d]\n", __func__, rc);
428 inode_lock(d_inode(lower_dir_dentry));
429 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
431 encrypted_and_encoded_name_size);
432 inode_unlock(d_inode(lower_dir_dentry));
433 if (IS_ERR(lower_dentry)) {
434 rc = PTR_ERR(lower_dentry);
435 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
436 "[%d] on lower_dentry = [%s]\n", __func__, rc,
437 encrypted_and_encoded_name);
441 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
444 kfree(encrypted_and_encoded_name);
448 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
449 struct dentry *new_dentry)
451 struct dentry *lower_old_dentry;
452 struct dentry *lower_new_dentry;
453 struct dentry *lower_dir_dentry;
457 file_size_save = i_size_read(d_inode(old_dentry));
458 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
459 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
460 dget(lower_old_dentry);
461 dget(lower_new_dentry);
462 lower_dir_dentry = lock_parent(lower_new_dentry);
463 rc = vfs_link(lower_old_dentry, d_inode(lower_dir_dentry),
464 lower_new_dentry, NULL);
465 if (rc || d_really_is_negative(lower_new_dentry))
467 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
470 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
471 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
472 set_nlink(d_inode(old_dentry),
473 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
474 i_size_write(d_inode(new_dentry), file_size_save);
476 unlock_dir(lower_dir_dentry);
477 dput(lower_new_dentry);
478 dput(lower_old_dentry);
482 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
484 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
487 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
491 struct dentry *lower_dentry;
492 struct dentry *lower_dir_dentry;
493 char *encoded_symname;
494 size_t encoded_symlen;
495 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
497 lower_dentry = ecryptfs_dentry_to_lower(dentry);
499 lower_dir_dentry = lock_parent(lower_dentry);
500 mount_crypt_stat = &ecryptfs_superblock_to_private(
501 dir->i_sb)->mount_crypt_stat;
502 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
505 mount_crypt_stat, symname,
509 rc = vfs_symlink(d_inode(lower_dir_dentry), lower_dentry,
511 kfree(encoded_symname);
512 if (rc || d_really_is_negative(lower_dentry))
514 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
517 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
518 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
520 unlock_dir(lower_dir_dentry);
522 if (d_really_is_negative(dentry))
527 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, umode_t mode)
530 struct dentry *lower_dentry;
531 struct dentry *lower_dir_dentry;
533 lower_dentry = ecryptfs_dentry_to_lower(dentry);
534 lower_dir_dentry = lock_parent(lower_dentry);
535 rc = vfs_mkdir(d_inode(lower_dir_dentry), lower_dentry, mode);
536 if (rc || d_really_is_negative(lower_dentry))
538 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
541 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
542 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
543 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
545 unlock_dir(lower_dir_dentry);
546 if (d_really_is_negative(dentry))
551 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
553 struct dentry *lower_dentry;
554 struct dentry *lower_dir_dentry;
557 lower_dentry = ecryptfs_dentry_to_lower(dentry);
559 lower_dir_dentry = lock_parent(lower_dentry);
561 rc = vfs_rmdir(d_inode(lower_dir_dentry), lower_dentry);
563 if (!rc && d_really_is_positive(dentry))
564 clear_nlink(d_inode(dentry));
565 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
566 set_nlink(dir, d_inode(lower_dir_dentry)->i_nlink);
567 unlock_dir(lower_dir_dentry);
575 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, umode_t mode, dev_t dev)
578 struct dentry *lower_dentry;
579 struct dentry *lower_dir_dentry;
581 lower_dentry = ecryptfs_dentry_to_lower(dentry);
582 lower_dir_dentry = lock_parent(lower_dentry);
583 rc = vfs_mknod(d_inode(lower_dir_dentry), lower_dentry, mode, dev);
584 if (rc || d_really_is_negative(lower_dentry))
586 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
589 fsstack_copy_attr_times(dir, d_inode(lower_dir_dentry));
590 fsstack_copy_inode_size(dir, d_inode(lower_dir_dentry));
592 unlock_dir(lower_dir_dentry);
593 if (d_really_is_negative(dentry))
599 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
600 struct inode *new_dir, struct dentry *new_dentry)
603 struct dentry *lower_old_dentry;
604 struct dentry *lower_new_dentry;
605 struct dentry *lower_old_dir_dentry;
606 struct dentry *lower_new_dir_dentry;
607 struct dentry *trap = NULL;
608 struct inode *target_inode;
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 target_inode = d_inode(new_dentry);
617 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
618 /* source should not be ancestor of target */
619 if (trap == lower_old_dentry) {
623 /* target should not be ancestor of source */
624 if (trap == lower_new_dentry) {
628 rc = vfs_rename(d_inode(lower_old_dir_dentry), lower_old_dentry,
629 d_inode(lower_new_dir_dentry), lower_new_dentry,
634 fsstack_copy_attr_all(target_inode,
635 ecryptfs_inode_to_lower(target_inode));
636 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
637 if (new_dir != old_dir)
638 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
640 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
641 dput(lower_new_dir_dentry);
642 dput(lower_old_dir_dentry);
643 dput(lower_new_dentry);
644 dput(lower_old_dentry);
648 static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
650 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
656 lower_buf = kmalloc(PATH_MAX, GFP_KERNEL);
658 return ERR_PTR(-ENOMEM);
661 rc = d_inode(lower_dentry)->i_op->readlink(lower_dentry,
662 (char __user *)lower_buf,
667 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
671 return rc ? ERR_PTR(rc) : buf;
674 static const char *ecryptfs_get_link(struct dentry *dentry,
676 struct delayed_call *done)
682 return ERR_PTR(-ECHILD);
684 buf = ecryptfs_readlink_lower(dentry, &len);
687 fsstack_copy_attr_atime(d_inode(dentry),
688 d_inode(ecryptfs_dentry_to_lower(dentry)));
690 set_delayed_call(done, kfree_link, buf);
695 * upper_size_to_lower_size
696 * @crypt_stat: Crypt_stat associated with file
697 * @upper_size: Size of the upper file
699 * Calculate the required size of the lower file based on the
700 * specified size of the upper file. This calculation is based on the
701 * number of headers in the underlying file and the extent size.
703 * Returns Calculated size of the lower file.
706 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
711 lower_size = ecryptfs_lower_header_size(crypt_stat);
712 if (upper_size != 0) {
715 num_extents = upper_size >> crypt_stat->extent_shift;
716 if (upper_size & ~crypt_stat->extent_mask)
718 lower_size += (num_extents * crypt_stat->extent_size);
725 * @dentry: The ecryptfs layer dentry
726 * @ia: Address of the ecryptfs inode's attributes
727 * @lower_ia: Address of the lower inode's attributes
729 * Function to handle truncations modifying the size of the file. Note
730 * that the file sizes are interpolated. When expanding, we are simply
731 * writing strings of 0's out. When truncating, we truncate the upper
732 * inode and update the lower_ia according to the page index
733 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
734 * the caller must use lower_ia in a call to notify_change() to perform
735 * the truncation of the lower inode.
737 * Returns zero on success; non-zero otherwise
739 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
740 struct iattr *lower_ia)
743 struct inode *inode = d_inode(dentry);
744 struct ecryptfs_crypt_stat *crypt_stat;
745 loff_t i_size = i_size_read(inode);
746 loff_t lower_size_before_truncate;
747 loff_t lower_size_after_truncate;
749 if (unlikely((ia->ia_size == i_size))) {
750 lower_ia->ia_valid &= ~ATTR_SIZE;
753 rc = ecryptfs_get_lower_file(dentry, inode);
756 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
757 /* Switch on growing or shrinking file */
758 if (ia->ia_size > i_size) {
759 char zero[] = { 0x00 };
761 lower_ia->ia_valid &= ~ATTR_SIZE;
762 /* Write a single 0 at the last position of the file;
763 * this triggers code that will fill in 0's throughout
764 * the intermediate portion of the previous end of the
765 * file and the new and of the file */
766 rc = ecryptfs_write(inode, zero,
767 (ia->ia_size - 1), 1);
768 } else { /* ia->ia_size < i_size_read(inode) */
769 /* We're chopping off all the pages down to the page
770 * in which ia->ia_size is located. Fill in the end of
771 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
772 * PAGE_CACHE_SIZE with zeros. */
773 size_t num_zeros = (PAGE_CACHE_SIZE
774 - (ia->ia_size & ~PAGE_CACHE_MASK));
776 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
777 truncate_setsize(inode, ia->ia_size);
778 lower_ia->ia_size = ia->ia_size;
779 lower_ia->ia_valid |= ATTR_SIZE;
785 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
790 rc = ecryptfs_write(inode, zeros_virt,
791 ia->ia_size, num_zeros);
794 printk(KERN_ERR "Error attempting to zero out "
795 "the remainder of the end page on "
796 "reducing truncate; rc = [%d]\n", rc);
800 truncate_setsize(inode, ia->ia_size);
801 rc = ecryptfs_write_inode_size_to_metadata(inode);
803 printk(KERN_ERR "Problem with "
804 "ecryptfs_write_inode_size_to_metadata; "
808 /* We are reducing the size of the ecryptfs file, and need to
809 * know if we need to reduce the size of the lower file. */
810 lower_size_before_truncate =
811 upper_size_to_lower_size(crypt_stat, i_size);
812 lower_size_after_truncate =
813 upper_size_to_lower_size(crypt_stat, ia->ia_size);
814 if (lower_size_after_truncate < lower_size_before_truncate) {
815 lower_ia->ia_size = lower_size_after_truncate;
816 lower_ia->ia_valid |= ATTR_SIZE;
818 lower_ia->ia_valid &= ~ATTR_SIZE;
821 ecryptfs_put_lower_file(inode);
825 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
827 struct ecryptfs_crypt_stat *crypt_stat;
828 loff_t lower_oldsize, lower_newsize;
830 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
831 lower_oldsize = upper_size_to_lower_size(crypt_stat,
833 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
834 if (lower_newsize > lower_oldsize) {
836 * The eCryptfs inode and the new *lower* size are mixed here
837 * because we may not have the lower i_mutex held and/or it may
838 * not be appropriate to call inode_newsize_ok() with inodes
839 * from other filesystems.
841 return inode_newsize_ok(inode, lower_newsize);
849 * @dentry: The ecryptfs layer dentry
850 * @new_length: The length to expand the file to
852 * Simple function that handles the truncation of an eCryptfs inode and
853 * its corresponding lower inode.
855 * Returns zero on success; non-zero otherwise
857 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
859 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
860 struct iattr lower_ia = { .ia_valid = 0 };
863 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
867 rc = truncate_upper(dentry, &ia, &lower_ia);
868 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
869 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
871 inode_lock(d_inode(lower_dentry));
872 rc = notify_change(lower_dentry, &lower_ia, NULL);
873 inode_unlock(d_inode(lower_dentry));
879 ecryptfs_permission(struct inode *inode, int mask)
881 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
886 * @dentry: dentry handle to the inode to modify
887 * @ia: Structure with flags of what to change and values
889 * Updates the metadata of an inode. If the update is to the size
890 * i.e. truncation, then ecryptfs_truncate will handle the size modification
891 * of both the ecryptfs inode and the lower inode.
893 * All other metadata changes will be passed right to the lower filesystem,
894 * and we will just update our inode to look like the lower.
896 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
899 struct dentry *lower_dentry;
900 struct iattr lower_ia;
902 struct inode *lower_inode;
903 struct ecryptfs_crypt_stat *crypt_stat;
905 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
906 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
907 ecryptfs_init_crypt_stat(crypt_stat);
908 inode = d_inode(dentry);
909 lower_inode = ecryptfs_inode_to_lower(inode);
910 lower_dentry = ecryptfs_dentry_to_lower(dentry);
911 mutex_lock(&crypt_stat->cs_mutex);
912 if (d_is_dir(dentry))
913 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
914 else if (d_is_reg(dentry)
915 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
916 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
917 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
919 mount_crypt_stat = &ecryptfs_superblock_to_private(
920 dentry->d_sb)->mount_crypt_stat;
921 rc = ecryptfs_get_lower_file(dentry, inode);
923 mutex_unlock(&crypt_stat->cs_mutex);
926 rc = ecryptfs_read_metadata(dentry);
927 ecryptfs_put_lower_file(inode);
929 if (!(mount_crypt_stat->flags
930 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
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);
941 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
942 | ECRYPTFS_ENCRYPTED);
945 mutex_unlock(&crypt_stat->cs_mutex);
947 rc = inode_change_ok(inode, ia);
950 if (ia->ia_valid & ATTR_SIZE) {
951 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
956 memcpy(&lower_ia, ia, sizeof(lower_ia));
957 if (ia->ia_valid & ATTR_FILE)
958 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
959 if (ia->ia_valid & ATTR_SIZE) {
960 rc = truncate_upper(dentry, ia, &lower_ia);
966 * mode change is for clearing setuid/setgid bits. Allow lower fs
967 * to interpret this in its own way.
969 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
970 lower_ia.ia_valid &= ~ATTR_MODE;
972 inode_lock(d_inode(lower_dentry));
973 rc = notify_change(lower_dentry, &lower_ia, NULL);
974 inode_unlock(d_inode(lower_dentry));
976 fsstack_copy_attr_all(inode, lower_inode);
980 static int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
983 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
986 mount_crypt_stat = &ecryptfs_superblock_to_private(
987 dentry->d_sb)->mount_crypt_stat;
988 generic_fillattr(d_inode(dentry), stat);
989 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
993 target = ecryptfs_readlink_lower(dentry, &targetsiz);
994 if (!IS_ERR(target)) {
996 stat->size = targetsiz;
998 rc = PTR_ERR(target);
1004 static int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1007 struct kstat lower_stat;
1010 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat);
1012 fsstack_copy_attr_all(d_inode(dentry),
1013 ecryptfs_inode_to_lower(d_inode(dentry)));
1014 generic_fillattr(d_inode(dentry), stat);
1015 stat->blocks = lower_stat.blocks;
1021 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1022 size_t size, int flags)
1025 struct dentry *lower_dentry;
1027 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1028 if (!d_inode(lower_dentry)->i_op->setxattr) {
1033 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1034 if (!rc && d_really_is_positive(dentry))
1035 fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
1041 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1042 void *value, size_t size)
1046 if (!d_inode(lower_dentry)->i_op->getxattr) {
1050 inode_lock(d_inode(lower_dentry));
1051 rc = d_inode(lower_dentry)->i_op->getxattr(lower_dentry, name, value,
1053 inode_unlock(d_inode(lower_dentry));
1059 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1062 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1067 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1070 struct dentry *lower_dentry;
1072 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1073 if (!d_inode(lower_dentry)->i_op->listxattr) {
1077 inode_lock(d_inode(lower_dentry));
1078 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1079 inode_unlock(d_inode(lower_dentry));
1084 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1087 struct dentry *lower_dentry;
1089 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1090 if (!d_inode(lower_dentry)->i_op->removexattr) {
1094 inode_lock(d_inode(lower_dentry));
1095 rc = d_inode(lower_dentry)->i_op->removexattr(lower_dentry, name);
1096 inode_unlock(d_inode(lower_dentry));
1101 const struct inode_operations ecryptfs_symlink_iops = {
1102 .readlink = generic_readlink,
1103 .get_link = ecryptfs_get_link,
1104 .permission = ecryptfs_permission,
1105 .setattr = ecryptfs_setattr,
1106 .getattr = ecryptfs_getattr_link,
1107 .setxattr = ecryptfs_setxattr,
1108 .getxattr = ecryptfs_getxattr,
1109 .listxattr = ecryptfs_listxattr,
1110 .removexattr = ecryptfs_removexattr
1113 const struct inode_operations ecryptfs_dir_iops = {
1114 .create = ecryptfs_create,
1115 .lookup = ecryptfs_lookup,
1116 .link = ecryptfs_link,
1117 .unlink = ecryptfs_unlink,
1118 .symlink = ecryptfs_symlink,
1119 .mkdir = ecryptfs_mkdir,
1120 .rmdir = ecryptfs_rmdir,
1121 .mknod = ecryptfs_mknod,
1122 .rename = ecryptfs_rename,
1123 .permission = ecryptfs_permission,
1124 .setattr = ecryptfs_setattr,
1125 .setxattr = ecryptfs_setxattr,
1126 .getxattr = ecryptfs_getxattr,
1127 .listxattr = ecryptfs_listxattr,
1128 .removexattr = ecryptfs_removexattr
1131 const struct inode_operations ecryptfs_main_iops = {
1132 .permission = ecryptfs_permission,
1133 .setattr = ecryptfs_setattr,
1134 .getattr = ecryptfs_getattr,
1135 .setxattr = ecryptfs_setxattr,
1136 .getxattr = ecryptfs_getxattr,
1137 .listxattr = ecryptfs_listxattr,
1138 .removexattr = ecryptfs_removexattr