2 * eCryptfs: Linux filesystem encryption layer
4 * Copyright (C) 1997-2004 Erez Zadok
5 * Copyright (C) 2001-2004 Stony Brook University
6 * Copyright (C) 2004-2007 International Business Machines Corp.
7 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
8 * Michael C. Thompsion <mcthomps@us.ibm.com>
10 * This program is free software; you can redistribute it and/or
11 * modify it under the terms of the GNU General Public License as
12 * published by the Free Software Foundation; either version 2 of the
13 * License, or (at your option) any later version.
15 * This program is distributed in the hope that it will be useful, but
16 * WITHOUT ANY WARRANTY; without even the implied warranty of
17 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
18 * General Public License for more details.
20 * You should have received a copy of the GNU General Public License
21 * along with this program; if not, write to the Free Software
22 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
26 #include <linux/file.h>
27 #include <linux/vmalloc.h>
28 #include <linux/pagemap.h>
29 #include <linux/dcache.h>
30 #include <linux/namei.h>
31 #include <linux/mount.h>
32 #include <linux/crypto.h>
33 #include <linux/fs_stack.h>
34 #include <linux/slab.h>
35 #include <linux/xattr.h>
36 #include <asm/unaligned.h>
37 #include "ecryptfs_kernel.h"
39 static struct dentry *lock_parent(struct dentry *dentry)
43 dir = dget_parent(dentry);
44 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
48 static void unlock_dir(struct dentry *dir)
50 mutex_unlock(&dir->d_inode->i_mutex);
55 * ecryptfs_create_underlying_file
56 * @lower_dir_inode: inode of the parent in the lower fs of the new file
57 * @dentry: New file's dentry
58 * @mode: The mode of the new file
59 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
61 * Creates the file in the lower file system.
63 * Returns zero on success; non-zero on error condition
66 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
67 struct dentry *dentry, int mode,
70 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
71 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
72 struct dentry *dentry_save;
73 struct vfsmount *vfsmount_save;
74 unsigned int flags_save;
77 dentry_save = nd->path.dentry;
78 vfsmount_save = nd->path.mnt;
79 flags_save = nd->flags;
80 nd->path.dentry = lower_dentry;
81 nd->path.mnt = lower_mnt;
82 nd->flags &= ~LOOKUP_OPEN;
83 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
84 nd->path.dentry = dentry_save;
85 nd->path.mnt = vfsmount_save;
86 nd->flags = flags_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 (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 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
124 "rc = [%d]\n", __func__, rc);
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
145 * This is the code which will grow the file to its correct size.
147 static int grow_file(struct dentry *ecryptfs_dentry)
149 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
150 char zero_virt[] = { 0x00 };
153 rc = ecryptfs_write(ecryptfs_inode, zero_virt, 0, 1);
154 i_size_write(ecryptfs_inode, 0);
155 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
156 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
162 * ecryptfs_initialize_file
164 * Cause the file to be changed from a basic empty file to an ecryptfs
165 * file with a header and first data page.
167 * Returns zero on success
169 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
171 struct ecryptfs_crypt_stat *crypt_stat =
172 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
175 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
176 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
177 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
180 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
181 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
182 rc = ecryptfs_new_file_context(ecryptfs_dentry);
184 ecryptfs_printk(KERN_ERR, "Error creating new file "
185 "context; rc = [%d]\n", rc);
188 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
190 printk(KERN_ERR "%s: Error attempting to initialize "
191 "the persistent file for the dentry with name "
192 "[%s]; rc = [%d]\n", __func__,
193 ecryptfs_dentry->d_name.name, rc);
196 rc = ecryptfs_write_metadata(ecryptfs_dentry);
198 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
201 rc = grow_file(ecryptfs_dentry);
203 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
210 * @dir: The inode of the directory in which to create the file.
211 * @dentry: The eCryptfs dentry
212 * @mode: The mode of the new file.
215 * Creates a new file.
217 * Returns zero on success; non-zero on error condition
220 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
221 int mode, struct nameidata *nd)
225 /* ecryptfs_do_create() calls ecryptfs_interpose() */
226 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
228 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
229 "lower filesystem\n");
232 /* At this point, a file exists on "disk"; we need to make sure
233 * that this on disk file is prepared to be an ecryptfs file */
234 rc = ecryptfs_initialize_file(ecryptfs_dentry);
240 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
242 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
243 struct dentry *lower_dentry,
244 struct inode *ecryptfs_dir_inode,
245 struct nameidata *ecryptfs_nd)
247 struct dentry *lower_dir_dentry;
248 struct vfsmount *lower_mnt;
249 struct inode *lower_inode;
250 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
251 struct ecryptfs_crypt_stat *crypt_stat;
252 char *page_virt = NULL;
256 lower_dir_dentry = lower_dentry->d_parent;
257 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
258 ecryptfs_dentry->d_parent));
259 lower_inode = lower_dentry->d_inode;
260 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
261 BUG_ON(!lower_dentry->d_count);
262 ecryptfs_set_dentry_private(ecryptfs_dentry,
263 kmem_cache_alloc(ecryptfs_dentry_info_cache,
265 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
267 printk(KERN_ERR "%s: Out of memory whilst attempting "
268 "to allocate ecryptfs_dentry_info struct\n",
272 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
273 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
274 if (!lower_dentry->d_inode) {
275 /* We want to add because we couldn't find in lower */
276 d_add(ecryptfs_dentry, NULL);
279 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
280 ecryptfs_dir_inode->i_sb,
281 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
283 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
287 if (S_ISDIR(lower_inode->i_mode))
289 if (S_ISLNK(lower_inode->i_mode))
291 if (special_file(lower_inode->i_mode))
295 /* Released in this function */
296 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
298 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
303 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
305 printk(KERN_ERR "%s: Error attempting to initialize "
306 "the persistent file for the dentry with name "
307 "[%s]; rc = [%d]\n", __func__,
308 ecryptfs_dentry->d_name.name, rc);
311 crypt_stat = &ecryptfs_inode_to_private(
312 ecryptfs_dentry->d_inode)->crypt_stat;
313 /* TODO: lock for crypt_stat comparison */
314 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
315 ecryptfs_set_default_sizes(crypt_stat);
316 rc = ecryptfs_read_and_validate_header_region(page_virt,
317 ecryptfs_dentry->d_inode);
319 memset(page_virt, 0, PAGE_CACHE_SIZE);
320 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
326 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
328 mount_crypt_stat = &ecryptfs_superblock_to_private(
329 ecryptfs_dentry->d_sb)->mount_crypt_stat;
330 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
331 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
332 file_size = (crypt_stat->metadata_size
333 + i_size_read(lower_dentry->d_inode));
335 file_size = i_size_read(lower_dentry->d_inode);
337 file_size = get_unaligned_be64(page_virt);
339 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
341 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
346 d_drop(ecryptfs_dentry);
353 * @ecryptfs_dir_inode: The eCryptfs directory inode
354 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
355 * @ecryptfs_nd: nameidata; may be NULL
357 * Find a file on disk. If the file does not exist, then we'll add it to the
358 * dentry cache and continue on to read it from the disk.
360 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
361 struct dentry *ecryptfs_dentry,
362 struct nameidata *ecryptfs_nd)
364 char *encrypted_and_encoded_name = NULL;
365 size_t encrypted_and_encoded_name_size;
366 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
367 struct dentry *lower_dir_dentry, *lower_dentry;
370 if ((ecryptfs_dentry->d_name.len == 1
371 && !strcmp(ecryptfs_dentry->d_name.name, "."))
372 || (ecryptfs_dentry->d_name.len == 2
373 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
376 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
377 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
378 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
380 ecryptfs_dentry->d_name.len);
381 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
382 if (IS_ERR(lower_dentry)) {
383 rc = PTR_ERR(lower_dentry);
384 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
385 "[%d] on lower_dentry = [%s]\n", __func__, rc,
386 encrypted_and_encoded_name);
389 if (lower_dentry->d_inode)
390 goto lookup_and_interpose;
391 mount_crypt_stat = &ecryptfs_superblock_to_private(
392 ecryptfs_dentry->d_sb)->mount_crypt_stat;
393 if (!(mount_crypt_stat
394 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
395 goto lookup_and_interpose;
397 rc = ecryptfs_encrypt_and_encode_filename(
398 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
399 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
400 ecryptfs_dentry->d_name.len);
402 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
403 "filename; rc = [%d]\n", __func__, rc);
406 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
407 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
409 encrypted_and_encoded_name_size);
410 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
411 if (IS_ERR(lower_dentry)) {
412 rc = PTR_ERR(lower_dentry);
413 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
414 "[%d] on lower_dentry = [%s]\n", __func__, rc,
415 encrypted_and_encoded_name);
418 lookup_and_interpose:
419 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
424 d_drop(ecryptfs_dentry);
426 kfree(encrypted_and_encoded_name);
430 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
431 struct dentry *new_dentry)
433 struct dentry *lower_old_dentry;
434 struct dentry *lower_new_dentry;
435 struct dentry *lower_dir_dentry;
439 file_size_save = i_size_read(old_dentry->d_inode);
440 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
441 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
442 dget(lower_old_dentry);
443 dget(lower_new_dentry);
444 lower_dir_dentry = lock_parent(lower_new_dentry);
445 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
447 if (rc || !lower_new_dentry->d_inode)
449 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
452 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
453 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
454 old_dentry->d_inode->i_nlink =
455 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
456 i_size_write(new_dentry->d_inode, file_size_save);
458 unlock_dir(lower_dir_dentry);
459 dput(lower_new_dentry);
460 dput(lower_old_dentry);
464 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
467 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
468 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
469 struct dentry *lower_dir_dentry;
472 lower_dir_dentry = lock_parent(lower_dentry);
473 rc = vfs_unlink(lower_dir_inode, lower_dentry);
475 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
478 fsstack_copy_attr_times(dir, lower_dir_inode);
479 dentry->d_inode->i_nlink =
480 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
481 dentry->d_inode->i_ctime = dir->i_ctime;
484 unlock_dir(lower_dir_dentry);
489 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
493 struct dentry *lower_dentry;
494 struct dentry *lower_dir_dentry;
495 char *encoded_symname;
496 size_t encoded_symlen;
497 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
499 lower_dentry = ecryptfs_dentry_to_lower(dentry);
501 lower_dir_dentry = lock_parent(lower_dentry);
502 mount_crypt_stat = &ecryptfs_superblock_to_private(
503 dir->i_sb)->mount_crypt_stat;
504 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
507 mount_crypt_stat, symname,
511 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
513 kfree(encoded_symname);
514 if (rc || !lower_dentry->d_inode)
516 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
519 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
520 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
522 unlock_dir(lower_dir_dentry);
524 if (!dentry->d_inode)
529 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
532 struct dentry *lower_dentry;
533 struct dentry *lower_dir_dentry;
535 lower_dentry = ecryptfs_dentry_to_lower(dentry);
536 lower_dir_dentry = lock_parent(lower_dentry);
537 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
538 if (rc || !lower_dentry->d_inode)
540 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
543 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
544 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
545 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
547 unlock_dir(lower_dir_dentry);
548 if (!dentry->d_inode)
553 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
555 struct dentry *lower_dentry;
556 struct dentry *lower_dir_dentry;
559 lower_dentry = ecryptfs_dentry_to_lower(dentry);
561 lower_dir_dentry = lock_parent(lower_dentry);
563 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
566 d_delete(lower_dentry);
567 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
568 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
569 unlock_dir(lower_dir_dentry);
577 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
580 struct dentry *lower_dentry;
581 struct dentry *lower_dir_dentry;
583 lower_dentry = ecryptfs_dentry_to_lower(dentry);
584 lower_dir_dentry = lock_parent(lower_dentry);
585 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
586 if (rc || !lower_dentry->d_inode)
588 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
591 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
592 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
594 unlock_dir(lower_dir_dentry);
595 if (!dentry->d_inode)
601 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
602 struct inode *new_dir, struct dentry *new_dentry)
605 struct dentry *lower_old_dentry;
606 struct dentry *lower_new_dentry;
607 struct dentry *lower_old_dir_dentry;
608 struct dentry *lower_new_dir_dentry;
609 struct dentry *trap = NULL;
611 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
612 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
613 dget(lower_old_dentry);
614 dget(lower_new_dentry);
615 lower_old_dir_dentry = dget_parent(lower_old_dentry);
616 lower_new_dir_dentry = dget_parent(lower_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(lower_old_dir_dentry->d_inode, lower_old_dentry,
629 lower_new_dir_dentry->d_inode, lower_new_dentry);
632 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
633 if (new_dir != old_dir)
634 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
636 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
637 dput(lower_new_dentry->d_parent);
638 dput(lower_old_dentry->d_parent);
639 dput(lower_new_dentry);
640 dput(lower_old_dentry);
644 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
647 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
649 size_t lower_bufsiz = PATH_MAX;
653 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
660 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
661 (char __user *)lower_buf,
667 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
668 lower_buf, lower_bufsiz);
675 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
678 size_t kbufsiz, copied;
681 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
684 copied = min_t(size_t, bufsiz, kbufsiz);
685 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
687 fsstack_copy_attr_atime(dentry->d_inode,
688 ecryptfs_dentry_to_lower(dentry)->d_inode);
693 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
696 int len = PAGE_SIZE, rc;
699 /* Released in ecryptfs_put_link(); only release here on error */
700 buf = kmalloc(len, GFP_KERNEL);
702 buf = ERR_PTR(-ENOMEM);
707 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
715 nd_set_link(nd, buf);
720 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
722 char *buf = nd_get_link(nd);
730 * upper_size_to_lower_size
731 * @crypt_stat: Crypt_stat associated with file
732 * @upper_size: Size of the upper file
734 * Calculate the required size of the lower file based on the
735 * specified size of the upper file. This calculation is based on the
736 * number of headers in the underlying file and the extent size.
738 * Returns Calculated size of the lower file.
741 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
746 lower_size = ecryptfs_lower_header_size(crypt_stat);
747 if (upper_size != 0) {
750 num_extents = upper_size >> crypt_stat->extent_shift;
751 if (upper_size & ~crypt_stat->extent_mask)
753 lower_size += (num_extents * crypt_stat->extent_size);
760 * @dentry: The ecryptfs layer dentry
761 * @ia: Address of the ecryptfs inode's attributes
762 * @lower_ia: Address of the lower inode's attributes
764 * Function to handle truncations modifying the size of the file. Note
765 * that the file sizes are interpolated. When expanding, we are simply
766 * writing strings of 0's out. When truncating, we truncate the upper
767 * inode and update the lower_ia according to the page index
768 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
769 * the caller must use lower_ia in a call to notify_change() to perform
770 * the truncation of the lower inode.
772 * Returns zero on success; non-zero otherwise
774 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
775 struct iattr *lower_ia)
778 struct inode *inode = dentry->d_inode;
779 struct ecryptfs_crypt_stat *crypt_stat;
780 loff_t i_size = i_size_read(inode);
781 loff_t lower_size_before_truncate;
782 loff_t lower_size_after_truncate;
784 if (unlikely((ia->ia_size == i_size))) {
785 lower_ia->ia_valid &= ~ATTR_SIZE;
788 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
789 /* Switch on growing or shrinking file */
790 if (ia->ia_size > i_size) {
791 char zero[] = { 0x00 };
793 lower_ia->ia_valid &= ~ATTR_SIZE;
794 /* Write a single 0 at the last position of the file;
795 * this triggers code that will fill in 0's throughout
796 * the intermediate portion of the previous end of the
797 * file and the new and of the file */
798 rc = ecryptfs_write(inode, zero,
799 (ia->ia_size - 1), 1);
800 } else { /* ia->ia_size < i_size_read(inode) */
801 /* We're chopping off all the pages down to the page
802 * in which ia->ia_size is located. Fill in the end of
803 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
804 * PAGE_CACHE_SIZE with zeros. */
805 size_t num_zeros = (PAGE_CACHE_SIZE
806 - (ia->ia_size & ~PAGE_CACHE_MASK));
810 * XXX(truncate) this should really happen at the begginning
811 * of ->setattr. But the code is too messy to that as part
812 * of a larger patch. ecryptfs is also totally missing out
813 * on the inode_change_ok check at the beginning of
814 * ->setattr while would include this.
816 rc = inode_newsize_ok(inode, ia->ia_size);
820 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
821 truncate_setsize(inode, ia->ia_size);
822 lower_ia->ia_size = ia->ia_size;
823 lower_ia->ia_valid |= ATTR_SIZE;
829 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
834 rc = ecryptfs_write(inode, zeros_virt,
835 ia->ia_size, num_zeros);
838 printk(KERN_ERR "Error attempting to zero out "
839 "the remainder of the end page on "
840 "reducing truncate; rc = [%d]\n", rc);
844 truncate_setsize(inode, ia->ia_size);
845 rc = ecryptfs_write_inode_size_to_metadata(inode);
847 printk(KERN_ERR "Problem with "
848 "ecryptfs_write_inode_size_to_metadata; "
852 /* We are reducing the size of the ecryptfs file, and need to
853 * know if we need to reduce the size of the lower file. */
854 lower_size_before_truncate =
855 upper_size_to_lower_size(crypt_stat, i_size);
856 lower_size_after_truncate =
857 upper_size_to_lower_size(crypt_stat, ia->ia_size);
858 if (lower_size_after_truncate < lower_size_before_truncate) {
859 lower_ia->ia_size = lower_size_after_truncate;
860 lower_ia->ia_valid |= ATTR_SIZE;
862 lower_ia->ia_valid &= ~ATTR_SIZE;
870 * @dentry: The ecryptfs layer dentry
871 * @new_length: The length to expand the file to
873 * Simple function that handles the truncation of an eCryptfs inode and
874 * its corresponding lower inode.
876 * Returns zero on success; non-zero otherwise
878 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
880 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
881 struct iattr lower_ia = { .ia_valid = 0 };
884 rc = truncate_upper(dentry, &ia, &lower_ia);
885 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
886 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
888 mutex_lock(&lower_dentry->d_inode->i_mutex);
889 rc = notify_change(lower_dentry, &lower_ia);
890 mutex_unlock(&lower_dentry->d_inode->i_mutex);
896 ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
898 if (flags & IPERM_FLAG_RCU)
900 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
905 * @dentry: dentry handle to the inode to modify
906 * @ia: Structure with flags of what to change and values
908 * Updates the metadata of an inode. If the update is to the size
909 * i.e. truncation, then ecryptfs_truncate will handle the size modification
910 * of both the ecryptfs inode and the lower inode.
912 * All other metadata changes will be passed right to the lower filesystem,
913 * and we will just update our inode to look like the lower.
915 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
918 struct dentry *lower_dentry;
919 struct iattr lower_ia;
921 struct inode *lower_inode;
922 struct ecryptfs_crypt_stat *crypt_stat;
924 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
925 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
926 ecryptfs_init_crypt_stat(crypt_stat);
927 inode = dentry->d_inode;
928 lower_inode = ecryptfs_inode_to_lower(inode);
929 lower_dentry = ecryptfs_dentry_to_lower(dentry);
930 mutex_lock(&crypt_stat->cs_mutex);
931 if (S_ISDIR(dentry->d_inode->i_mode))
932 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
933 else if (S_ISREG(dentry->d_inode->i_mode)
934 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
935 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
936 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
938 mount_crypt_stat = &ecryptfs_superblock_to_private(
939 dentry->d_sb)->mount_crypt_stat;
940 rc = ecryptfs_read_metadata(dentry);
942 if (!(mount_crypt_stat->flags
943 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
945 printk(KERN_WARNING "Either the lower file "
946 "is not in a valid eCryptfs format, "
947 "or the key could not be retrieved. "
948 "Plaintext passthrough mode is not "
949 "enabled; returning -EIO\n");
950 mutex_unlock(&crypt_stat->cs_mutex);
954 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
957 mutex_unlock(&crypt_stat->cs_mutex);
958 memcpy(&lower_ia, ia, sizeof(lower_ia));
959 if (ia->ia_valid & ATTR_FILE)
960 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
961 if (ia->ia_valid & ATTR_SIZE) {
962 rc = truncate_upper(dentry, ia, &lower_ia);
968 * mode change is for clearing setuid/setgid bits. Allow lower fs
969 * to interpret this in its own way.
971 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
972 lower_ia.ia_valid &= ~ATTR_MODE;
974 mutex_lock(&lower_dentry->d_inode->i_mutex);
975 rc = notify_change(lower_dentry, &lower_ia);
976 mutex_unlock(&lower_dentry->d_inode->i_mutex);
978 fsstack_copy_attr_all(inode, lower_inode);
982 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
985 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
988 mount_crypt_stat = &ecryptfs_superblock_to_private(
989 dentry->d_sb)->mount_crypt_stat;
990 generic_fillattr(dentry->d_inode, stat);
991 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
995 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
998 stat->size = targetsiz;
1004 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1007 struct kstat lower_stat;
1010 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1011 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1013 generic_fillattr(dentry->d_inode, stat);
1014 stat->blocks = lower_stat.blocks;
1020 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1021 size_t size, int flags)
1024 struct dentry *lower_dentry;
1026 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1027 if (!lower_dentry->d_inode->i_op->setxattr) {
1032 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1038 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1039 void *value, size_t size)
1043 if (!lower_dentry->d_inode->i_op->getxattr) {
1047 mutex_lock(&lower_dentry->d_inode->i_mutex);
1048 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1050 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1056 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1059 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1064 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1067 struct dentry *lower_dentry;
1069 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1070 if (!lower_dentry->d_inode->i_op->listxattr) {
1074 mutex_lock(&lower_dentry->d_inode->i_mutex);
1075 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1076 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1081 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1084 struct dentry *lower_dentry;
1086 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1087 if (!lower_dentry->d_inode->i_op->removexattr) {
1091 mutex_lock(&lower_dentry->d_inode->i_mutex);
1092 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1093 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1098 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1100 if ((ecryptfs_inode_to_lower(inode)
1101 == (struct inode *)candidate_lower_inode))
1107 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1109 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1113 const struct inode_operations ecryptfs_symlink_iops = {
1114 .readlink = ecryptfs_readlink,
1115 .follow_link = ecryptfs_follow_link,
1116 .put_link = ecryptfs_put_link,
1117 .permission = ecryptfs_permission,
1118 .setattr = ecryptfs_setattr,
1119 .getattr = ecryptfs_getattr_link,
1120 .setxattr = ecryptfs_setxattr,
1121 .getxattr = ecryptfs_getxattr,
1122 .listxattr = ecryptfs_listxattr,
1123 .removexattr = ecryptfs_removexattr
1126 const struct inode_operations ecryptfs_dir_iops = {
1127 .create = ecryptfs_create,
1128 .lookup = ecryptfs_lookup,
1129 .link = ecryptfs_link,
1130 .unlink = ecryptfs_unlink,
1131 .symlink = ecryptfs_symlink,
1132 .mkdir = ecryptfs_mkdir,
1133 .rmdir = ecryptfs_rmdir,
1134 .mknod = ecryptfs_mknod,
1135 .rename = ecryptfs_rename,
1136 .permission = ecryptfs_permission,
1137 .setattr = ecryptfs_setattr,
1138 .setxattr = ecryptfs_setxattr,
1139 .getxattr = ecryptfs_getxattr,
1140 .listxattr = ecryptfs_listxattr,
1141 .removexattr = ecryptfs_removexattr
1144 const struct inode_operations ecryptfs_main_iops = {
1145 .permission = ecryptfs_permission,
1146 .setattr = ecryptfs_setattr,
1147 .getattr = ecryptfs_getattr,
1148 .setxattr = ecryptfs_setxattr,
1149 .getxattr = ecryptfs_getxattr,
1150 .listxattr = ecryptfs_listxattr,
1151 .removexattr = ecryptfs_removexattr