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 "ecryptfs_kernel.h"
36 static struct dentry *lock_parent(struct dentry *dentry)
40 dir = dget(dentry->d_parent);
41 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
45 static void unlock_parent(struct dentry *dentry)
47 mutex_unlock(&(dentry->d_parent->d_inode->i_mutex));
48 dput(dentry->d_parent);
51 static void unlock_dir(struct dentry *dir)
53 mutex_unlock(&dir->d_inode->i_mutex);
58 * ecryptfs_create_underlying_file
59 * @lower_dir_inode: inode of the parent in the lower fs of the new file
60 * @lower_dentry: New file's dentry in the lower fs
61 * @ecryptfs_dentry: New file's dentry in ecryptfs
62 * @mode: The mode of the new file
63 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
65 * Creates the file in the lower file system.
67 * Returns zero on success; non-zero on error condition
70 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
71 struct dentry *dentry, int mode,
74 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
75 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
76 struct dentry *dentry_save;
77 struct vfsmount *vfsmount_save;
80 dentry_save = nd->dentry;
81 vfsmount_save = nd->mnt;
82 nd->dentry = lower_dentry;
84 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
85 nd->dentry = dentry_save;
86 nd->mnt = vfsmount_save;
92 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
93 * @ecryptfs_dentry: New file's dentry in ecryptfs
94 * @mode: The mode of the new file
95 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
97 * Creates the underlying file and the eCryptfs inode which will link to
98 * it. It will also update the eCryptfs directory inode to mimic the
99 * stat of the lower directory inode.
101 * Returns zero on success; non-zero on error condition
104 ecryptfs_do_create(struct inode *directory_inode,
105 struct dentry *ecryptfs_dentry, int mode,
106 struct nameidata *nd)
109 struct dentry *lower_dentry;
110 struct dentry *lower_dir_dentry;
112 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
113 lower_dir_dentry = lock_parent(lower_dentry);
114 if (unlikely(IS_ERR(lower_dir_dentry))) {
115 ecryptfs_printk(KERN_ERR, "Error locking directory of "
117 rc = PTR_ERR(lower_dir_dentry);
120 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
121 ecryptfs_dentry, mode, nd);
123 ecryptfs_printk(KERN_ERR,
124 "Failure to create underlying file\n");
127 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
128 directory_inode->i_sb, 0);
130 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
133 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
134 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
136 unlock_dir(lower_dir_dentry);
143 * @ecryptfs_dentry: the ecryptfs dentry
144 * @lower_file: The lower file
145 * @inode: The ecryptfs inode
146 * @lower_inode: The lower inode
148 * This is the code which will grow the file to its correct size.
150 static int grow_file(struct dentry *ecryptfs_dentry, struct file *lower_file,
151 struct inode *inode, struct inode *lower_inode)
154 struct file fake_file;
155 struct ecryptfs_file_info tmp_file_info;
157 memset(&fake_file, 0, sizeof(fake_file));
158 fake_file.f_path.dentry = ecryptfs_dentry;
159 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
160 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
161 ecryptfs_set_file_lower(&fake_file, lower_file);
162 rc = ecryptfs_fill_zeros(&fake_file, 1);
164 ecryptfs_inode_to_private(inode)->crypt_stat.flags |=
165 ECRYPTFS_SECURITY_WARNING;
166 ecryptfs_printk(KERN_WARNING, "Error attempting to fill zeros "
167 "in file; rc = [%d]\n", rc);
170 i_size_write(inode, 0);
171 rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
172 inode, ecryptfs_dentry,
173 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
174 ecryptfs_inode_to_private(inode)->crypt_stat.flags |= ECRYPTFS_NEW_FILE;
180 * ecryptfs_initialize_file
182 * Cause the file to be changed from a basic empty file to an ecryptfs
183 * file with a header and first data page.
185 * Returns zero on success
187 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
191 struct ecryptfs_crypt_stat *crypt_stat;
192 struct dentry *lower_dentry;
193 struct file *lower_file;
194 struct inode *inode, *lower_inode;
195 struct vfsmount *lower_mnt;
197 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
198 ecryptfs_printk(KERN_DEBUG, "lower_dentry->d_name.name = [%s]\n",
199 lower_dentry->d_name.name);
200 inode = ecryptfs_dentry->d_inode;
201 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
202 lower_flags = ((O_CREAT | O_TRUNC) & O_ACCMODE) | O_RDWR;
203 lower_mnt = ecryptfs_dentry_to_lower_mnt(ecryptfs_dentry);
204 /* Corresponding fput() at end of this function */
205 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
207 ecryptfs_printk(KERN_ERR,
208 "Error opening dentry; rc = [%i]\n", rc);
211 lower_inode = lower_dentry->d_inode;
212 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
213 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
214 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
217 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
218 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
219 rc = ecryptfs_new_file_context(ecryptfs_dentry);
221 ecryptfs_printk(KERN_DEBUG, "Error creating new file "
225 rc = ecryptfs_write_metadata(ecryptfs_dentry, lower_file);
227 ecryptfs_printk(KERN_DEBUG, "Error writing headers\n");
230 rc = grow_file(ecryptfs_dentry, lower_file, inode, lower_inode);
232 if ((rc = ecryptfs_close_lower_file(lower_file)))
233 printk(KERN_ERR "Error closing lower_file\n");
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.
245 * Creates a new file.
247 * Returns zero on success; non-zero on error condition
250 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
251 int mode, struct nameidata *nd)
255 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
257 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
258 "lower filesystem\n");
261 /* At this point, a file exists on "disk"; we need to make sure
262 * that this on disk file is prepared to be an ecryptfs file */
263 rc = ecryptfs_initialize_file(ecryptfs_dentry);
271 * @dentry: The dentry
272 * @nd: nameidata, may be NULL
274 * Find a file on disk. If the file does not exist, then we'll add it to the
275 * dentry cache and continue on to read it from the disk.
277 static struct dentry *ecryptfs_lookup(struct inode *dir, struct dentry *dentry,
278 struct nameidata *nd)
281 struct dentry *lower_dir_dentry;
282 struct dentry *lower_dentry;
283 struct vfsmount *lower_mnt;
286 struct ecryptfs_crypt_stat *crypt_stat = NULL;
287 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
288 char *page_virt = NULL;
289 struct inode *lower_inode;
292 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
293 dentry->d_op = &ecryptfs_dops;
294 if ((dentry->d_name.len == 1 && !strcmp(dentry->d_name.name, "."))
295 || (dentry->d_name.len == 2
296 && !strcmp(dentry->d_name.name, ".."))) {
300 encoded_namelen = ecryptfs_encode_filename(crypt_stat,
304 if (encoded_namelen < 0) {
305 rc = encoded_namelen;
309 ecryptfs_printk(KERN_DEBUG, "encoded_name = [%s]; encoded_namelen "
310 "= [%d]\n", encoded_name, encoded_namelen);
311 lower_dentry = lookup_one_len(encoded_name, lower_dir_dentry,
312 encoded_namelen - 1);
314 if (IS_ERR(lower_dentry)) {
315 ecryptfs_printk(KERN_ERR, "ERR from lower_dentry\n");
316 rc = PTR_ERR(lower_dentry);
320 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
321 ecryptfs_printk(KERN_DEBUG, "lower_dentry = [%p]; lower_dentry->"
322 "d_name.name = [%s]\n", lower_dentry,
323 lower_dentry->d_name.name);
324 lower_inode = lower_dentry->d_inode;
325 fsstack_copy_attr_atime(dir, lower_dir_dentry->d_inode);
326 BUG_ON(!atomic_read(&lower_dentry->d_count));
327 ecryptfs_set_dentry_private(dentry,
328 kmem_cache_alloc(ecryptfs_dentry_info_cache,
330 if (!ecryptfs_dentry_to_private(dentry)) {
332 ecryptfs_printk(KERN_ERR, "Out of memory whilst attempting "
333 "to allocate ecryptfs_dentry_info struct\n");
336 ecryptfs_set_dentry_lower(dentry, lower_dentry);
337 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
338 if (!lower_dentry->d_inode) {
339 /* We want to add because we couldn't find in lower */
343 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 1);
345 ecryptfs_printk(KERN_ERR, "Error interposing\n");
348 if (S_ISDIR(lower_inode->i_mode)) {
349 ecryptfs_printk(KERN_DEBUG, "Is a directory; returning\n");
352 if (S_ISLNK(lower_inode->i_mode)) {
353 ecryptfs_printk(KERN_DEBUG, "Is a symlink; returning\n");
356 if (special_file(lower_inode->i_mode)) {
357 ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
360 if (special_file(lower_inode->i_mode)) {
361 ecryptfs_printk(KERN_DEBUG, "Is a special file; returning\n");
365 ecryptfs_printk(KERN_DEBUG, "We have a NULL nd, just leave"
366 "as we *think* we are about to unlink\n");
369 /* Released in this function */
370 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2,
374 ecryptfs_printk(KERN_ERR,
375 "Cannot ecryptfs_kmalloc a page\n");
378 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
379 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
380 ecryptfs_set_default_sizes(crypt_stat);
381 rc = ecryptfs_read_and_validate_header_region(page_virt, lower_dentry,
384 rc = ecryptfs_read_and_validate_xattr_region(page_virt, dentry);
386 printk(KERN_DEBUG "Valid metadata not found in header "
387 "region or xattr region; treating file as "
390 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
393 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
395 mount_crypt_stat = &ecryptfs_superblock_to_private(
396 dentry->d_sb)->mount_crypt_stat;
397 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
398 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
399 file_size = (crypt_stat->header_extent_size
400 + i_size_read(lower_dentry->d_inode));
402 file_size = i_size_read(lower_dentry->d_inode);
404 memcpy(&file_size, page_virt, sizeof(file_size));
405 file_size = be64_to_cpu(file_size);
407 i_size_write(dentry->d_inode, (loff_t)file_size);
408 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
418 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
419 struct dentry *new_dentry)
421 struct dentry *lower_old_dentry;
422 struct dentry *lower_new_dentry;
423 struct dentry *lower_dir_dentry;
427 file_size_save = i_size_read(old_dentry->d_inode);
428 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
429 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
430 dget(lower_old_dentry);
431 dget(lower_new_dentry);
432 lower_dir_dentry = lock_parent(lower_new_dentry);
433 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
435 if (rc || !lower_new_dentry->d_inode)
437 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
440 fsstack_copy_attr_times(dir, lower_new_dentry->d_inode);
441 fsstack_copy_inode_size(dir, lower_new_dentry->d_inode);
442 old_dentry->d_inode->i_nlink =
443 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
444 i_size_write(new_dentry->d_inode, file_size_save);
446 unlock_dir(lower_dir_dentry);
447 dput(lower_new_dentry);
448 dput(lower_old_dentry);
449 d_drop(lower_old_dentry);
455 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
458 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
459 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
461 lock_parent(lower_dentry);
462 rc = vfs_unlink(lower_dir_inode, lower_dentry);
464 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
467 fsstack_copy_attr_times(dir, lower_dir_inode);
468 dentry->d_inode->i_nlink =
469 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
470 dentry->d_inode->i_ctime = dir->i_ctime;
472 unlock_parent(lower_dentry);
476 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
480 struct dentry *lower_dentry;
481 struct dentry *lower_dir_dentry;
483 char *encoded_symname;
485 struct ecryptfs_crypt_stat *crypt_stat = NULL;
487 lower_dentry = ecryptfs_dentry_to_lower(dentry);
489 lower_dir_dentry = lock_parent(lower_dentry);
491 encoded_symlen = ecryptfs_encode_filename(crypt_stat, symname,
494 if (encoded_symlen < 0) {
498 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
499 encoded_symname, mode);
500 kfree(encoded_symname);
501 if (rc || !lower_dentry->d_inode)
503 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
506 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
507 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
509 unlock_dir(lower_dir_dentry);
511 if (!dentry->d_inode)
516 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
519 struct dentry *lower_dentry;
520 struct dentry *lower_dir_dentry;
522 lower_dentry = ecryptfs_dentry_to_lower(dentry);
523 lower_dir_dentry = lock_parent(lower_dentry);
524 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
525 if (rc || !lower_dentry->d_inode)
527 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
530 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
531 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
532 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
534 unlock_dir(lower_dir_dentry);
535 if (!dentry->d_inode)
540 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
542 struct dentry *lower_dentry;
543 struct dentry *lower_dir_dentry;
546 lower_dentry = ecryptfs_dentry_to_lower(dentry);
548 lower_dir_dentry = lock_parent(lower_dentry);
550 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
553 d_delete(lower_dentry);
554 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
555 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
556 unlock_dir(lower_dir_dentry);
564 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
567 struct dentry *lower_dentry;
568 struct dentry *lower_dir_dentry;
570 lower_dentry = ecryptfs_dentry_to_lower(dentry);
571 lower_dir_dentry = lock_parent(lower_dentry);
572 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
573 if (rc || !lower_dentry->d_inode)
575 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
578 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
579 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
581 unlock_dir(lower_dir_dentry);
582 if (!dentry->d_inode)
588 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
589 struct inode *new_dir, struct dentry *new_dentry)
592 struct dentry *lower_old_dentry;
593 struct dentry *lower_new_dentry;
594 struct dentry *lower_old_dir_dentry;
595 struct dentry *lower_new_dir_dentry;
597 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
598 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
599 dget(lower_old_dentry);
600 dget(lower_new_dentry);
601 lower_old_dir_dentry = dget_parent(lower_old_dentry);
602 lower_new_dir_dentry = dget_parent(lower_new_dentry);
603 lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
604 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
605 lower_new_dir_dentry->d_inode, lower_new_dentry);
608 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode, NULL);
609 if (new_dir != old_dir)
610 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode, NULL);
612 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
613 dput(lower_new_dentry->d_parent);
614 dput(lower_old_dentry->d_parent);
615 dput(lower_new_dentry);
616 dput(lower_old_dentry);
621 ecryptfs_readlink(struct dentry *dentry, char __user * buf, int bufsiz)
624 struct dentry *lower_dentry;
628 struct ecryptfs_crypt_stat *crypt_stat;
630 lower_dentry = ecryptfs_dentry_to_lower(dentry);
631 if (!lower_dentry->d_inode->i_op ||
632 !lower_dentry->d_inode->i_op->readlink) {
636 /* Released in this function */
637 lower_buf = kmalloc(bufsiz, GFP_KERNEL);
638 if (lower_buf == NULL) {
639 ecryptfs_printk(KERN_ERR, "Out of memory\n");
645 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
646 "lower_dentry->d_name.name = [%s]\n",
647 lower_dentry->d_name.name);
648 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
649 (char __user *)lower_buf,
654 rc = ecryptfs_decode_filename(crypt_stat, lower_buf, rc,
657 goto out_free_lower_buf;
659 ecryptfs_printk(KERN_DEBUG, "Copying [%d] bytes "
660 "to userspace: [%*s]\n", rc,
662 if (copy_to_user(buf, decoded_name, rc))
666 fsstack_copy_attr_atime(dentry->d_inode,
667 lower_dentry->d_inode);
675 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
678 int len = PAGE_SIZE, rc;
681 /* Released in ecryptfs_put_link(); only release here on error */
682 buf = kmalloc(len, GFP_KERNEL);
689 ecryptfs_printk(KERN_DEBUG, "Calling readlink w/ "
690 "dentry->d_name.name = [%s]\n", dentry->d_name.name);
691 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
697 nd_set_link(nd, buf);
706 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
709 kfree(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 requried 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 = ( crypt_stat->header_extent_size
730 * crypt_stat->num_header_extents_at_front );
731 if (upper_size != 0) {
734 num_extents = upper_size >> crypt_stat->extent_shift;
735 if (upper_size & ~crypt_stat->extent_mask)
737 lower_size += (num_extents * crypt_stat->extent_size);
744 * @dentry: The ecryptfs layer dentry
745 * @new_length: The length to expand the file to
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 need to modify the
750 * underlying file size according to the page index interpolations.
752 * Returns zero on success; non-zero otherwise
754 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
757 struct inode *inode = dentry->d_inode;
758 struct dentry *lower_dentry;
759 struct vfsmount *lower_mnt;
760 struct file fake_ecryptfs_file, *lower_file = NULL;
761 struct ecryptfs_crypt_stat *crypt_stat;
762 loff_t i_size = i_size_read(inode);
763 loff_t lower_size_before_truncate;
764 loff_t lower_size_after_truncate;
766 if (unlikely((new_length == i_size)))
768 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
769 /* Set up a fake ecryptfs file, this is used to interface with
770 * the file in the underlying filesystem so that the
771 * truncation has an effect there as well. */
772 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
773 fake_ecryptfs_file.f_path.dentry = dentry;
774 /* Released at out_free: label */
775 ecryptfs_set_file_private(&fake_ecryptfs_file,
776 kmem_cache_alloc(ecryptfs_file_info_cache,
778 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
782 lower_dentry = ecryptfs_dentry_to_lower(dentry);
783 /* This dget & mntget is released through fput at out_fput: */
784 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
785 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry, lower_mnt,
787 ecryptfs_printk(KERN_ERR,
788 "Error opening dentry; rc = [%i]\n", rc);
791 ecryptfs_set_file_lower(&fake_ecryptfs_file, lower_file);
792 /* Switch on growing or shrinking file */
793 if (new_length > i_size) {
794 rc = ecryptfs_fill_zeros(&fake_ecryptfs_file, new_length);
796 ecryptfs_printk(KERN_ERR,
797 "Problem with fill_zeros\n");
800 i_size_write(inode, new_length);
801 rc = ecryptfs_write_inode_size_to_metadata(
802 lower_file, lower_dentry->d_inode, inode, dentry,
803 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
805 printk(KERN_ERR "Problem with "
806 "ecryptfs_write_inode_size_to_metadata; "
810 } else { /* new_length < i_size_read(inode) */
812 int end_pos_in_page = -1;
814 if (new_length != 0) {
815 index = ((new_length - 1) >> PAGE_CACHE_SHIFT);
816 end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK);
818 if (end_pos_in_page != (PAGE_CACHE_SIZE - 1)) {
819 if ((rc = ecryptfs_write_zeros(&fake_ecryptfs_file,
821 (end_pos_in_page + 1),
822 ((PAGE_CACHE_SIZE - 1)
823 - end_pos_in_page)))) {
824 printk(KERN_ERR "Error attempting to zero out "
825 "the remainder of the end page on "
826 "reducing truncate; rc = [%d]\n", rc);
830 vmtruncate(inode, new_length);
831 rc = ecryptfs_write_inode_size_to_metadata(
832 lower_file, lower_dentry->d_inode, inode, dentry,
833 ECRYPTFS_LOWER_I_MUTEX_NOT_HELD);
835 printk(KERN_ERR "Problem with "
836 "ecryptfs_write_inode_size_to_metadata; "
840 /* We are reducing the size of the ecryptfs file, and need to
841 * know if we need to reduce the size of the lower file. */
842 lower_size_before_truncate =
843 upper_size_to_lower_size(crypt_stat, i_size);
844 lower_size_after_truncate =
845 upper_size_to_lower_size(crypt_stat, new_length);
846 if (lower_size_after_truncate < lower_size_before_truncate)
847 vmtruncate(lower_dentry->d_inode,
848 lower_size_after_truncate);
850 /* Update the access times */
851 lower_dentry->d_inode->i_mtime = lower_dentry->d_inode->i_ctime
853 mark_inode_dirty_sync(inode);
855 if ((rc = ecryptfs_close_lower_file(lower_file)))
856 printk(KERN_ERR "Error closing lower_file\n");
858 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
859 kmem_cache_free(ecryptfs_file_info_cache,
860 ecryptfs_file_to_private(&fake_ecryptfs_file));
866 ecryptfs_permission(struct inode *inode, int mask, struct nameidata *nd)
871 struct vfsmount *vfsmnt_save = nd->mnt;
872 struct dentry *dentry_save = nd->dentry;
874 nd->mnt = ecryptfs_dentry_to_lower_mnt(nd->dentry);
875 nd->dentry = ecryptfs_dentry_to_lower(nd->dentry);
876 rc = permission(ecryptfs_inode_to_lower(inode), mask, nd);
877 nd->mnt = vfsmnt_save;
878 nd->dentry = dentry_save;
880 rc = permission(ecryptfs_inode_to_lower(inode), mask, NULL);
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;
901 struct inode *lower_inode;
902 struct ecryptfs_crypt_stat *crypt_stat;
904 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
905 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
906 ecryptfs_init_crypt_stat(crypt_stat);
907 inode = dentry->d_inode;
908 lower_inode = ecryptfs_inode_to_lower(inode);
909 lower_dentry = ecryptfs_dentry_to_lower(dentry);
910 mutex_lock(&crypt_stat->cs_mutex);
911 if (S_ISDIR(dentry->d_inode->i_mode))
912 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
913 else if (S_ISREG(dentry->d_inode->i_mode)
914 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
915 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
916 struct vfsmount *lower_mnt;
917 struct file *lower_file = NULL;
918 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
921 lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
922 lower_flags = O_RDONLY;
923 if ((rc = ecryptfs_open_lower_file(&lower_file, lower_dentry,
924 lower_mnt, lower_flags))) {
926 "Error opening lower file; rc = [%d]\n", rc);
927 mutex_unlock(&crypt_stat->cs_mutex);
930 mount_crypt_stat = &ecryptfs_superblock_to_private(
931 dentry->d_sb)->mount_crypt_stat;
932 if ((rc = ecryptfs_read_metadata(dentry, lower_file))) {
933 if (!(mount_crypt_stat->flags
934 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
936 printk(KERN_WARNING "Attempt to read file that "
937 "is not in a valid eCryptfs format, "
938 "and plaintext passthrough mode is not "
939 "enabled; returning -EIO\n");
941 mutex_unlock(&crypt_stat->cs_mutex);
946 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
947 mutex_unlock(&crypt_stat->cs_mutex);
953 mutex_unlock(&crypt_stat->cs_mutex);
954 if (ia->ia_valid & ATTR_SIZE) {
955 ecryptfs_printk(KERN_DEBUG,
956 "ia->ia_valid = [0x%x] ATTR_SIZE" " = [0x%x]\n",
957 ia->ia_valid, ATTR_SIZE);
958 rc = ecryptfs_truncate(dentry, ia->ia_size);
959 /* ecryptfs_truncate handles resizing of the lower file */
960 ia->ia_valid &= ~ATTR_SIZE;
961 ecryptfs_printk(KERN_DEBUG, "ia->ia_valid = [%x]\n",
966 rc = notify_change(lower_dentry, ia);
968 fsstack_copy_attr_all(inode, lower_inode, NULL);
973 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
974 size_t size, int flags)
977 struct dentry *lower_dentry;
979 lower_dentry = ecryptfs_dentry_to_lower(dentry);
980 if (!lower_dentry->d_inode->i_op->setxattr) {
984 mutex_lock(&lower_dentry->d_inode->i_mutex);
985 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
987 mutex_unlock(&lower_dentry->d_inode->i_mutex);
993 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
997 struct dentry *lower_dentry;
999 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1000 if (!lower_dentry->d_inode->i_op->getxattr) {
1004 mutex_lock(&lower_dentry->d_inode->i_mutex);
1005 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1007 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1013 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1016 struct dentry *lower_dentry;
1018 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1019 if (!lower_dentry->d_inode->i_op->listxattr) {
1023 mutex_lock(&lower_dentry->d_inode->i_mutex);
1024 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1025 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1030 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1033 struct dentry *lower_dentry;
1035 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1036 if (!lower_dentry->d_inode->i_op->removexattr) {
1040 mutex_lock(&lower_dentry->d_inode->i_mutex);
1041 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1042 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1047 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1049 if ((ecryptfs_inode_to_lower(inode)
1050 == (struct inode *)candidate_lower_inode))
1056 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1058 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1062 const struct inode_operations ecryptfs_symlink_iops = {
1063 .readlink = ecryptfs_readlink,
1064 .follow_link = ecryptfs_follow_link,
1065 .put_link = ecryptfs_put_link,
1066 .permission = ecryptfs_permission,
1067 .setattr = ecryptfs_setattr,
1068 .setxattr = ecryptfs_setxattr,
1069 .getxattr = ecryptfs_getxattr,
1070 .listxattr = ecryptfs_listxattr,
1071 .removexattr = ecryptfs_removexattr
1074 const struct inode_operations ecryptfs_dir_iops = {
1075 .create = ecryptfs_create,
1076 .lookup = ecryptfs_lookup,
1077 .link = ecryptfs_link,
1078 .unlink = ecryptfs_unlink,
1079 .symlink = ecryptfs_symlink,
1080 .mkdir = ecryptfs_mkdir,
1081 .rmdir = ecryptfs_rmdir,
1082 .mknod = ecryptfs_mknod,
1083 .rename = ecryptfs_rename,
1084 .permission = ecryptfs_permission,
1085 .setattr = ecryptfs_setattr,
1086 .setxattr = ecryptfs_setxattr,
1087 .getxattr = ecryptfs_getxattr,
1088 .listxattr = ecryptfs_listxattr,
1089 .removexattr = ecryptfs_removexattr
1092 const struct inode_operations ecryptfs_main_iops = {
1093 .permission = ecryptfs_permission,
1094 .setattr = ecryptfs_setattr,
1095 .setxattr = ecryptfs_setxattr,
1096 .getxattr = ecryptfs_getxattr,
1097 .listxattr = ecryptfs_listxattr,
1098 .removexattr = ecryptfs_removexattr