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 <asm/unaligned.h>
36 #include "ecryptfs_kernel.h"
38 static struct dentry *lock_parent(struct dentry *dentry)
42 dir = dget_parent(dentry);
43 mutex_lock_nested(&(dir->d_inode->i_mutex), I_MUTEX_PARENT);
47 static void unlock_dir(struct dentry *dir)
49 mutex_unlock(&dir->d_inode->i_mutex);
54 * ecryptfs_create_underlying_file
55 * @lower_dir_inode: inode of the parent in the lower fs of the new file
56 * @dentry: New file's dentry
57 * @mode: The mode of the new file
58 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
60 * Creates the file in the lower file system.
62 * Returns zero on success; non-zero on error condition
65 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
66 struct dentry *dentry, int mode,
69 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
70 struct vfsmount *lower_mnt = ecryptfs_dentry_to_lower_mnt(dentry);
71 struct dentry *dentry_save;
72 struct vfsmount *vfsmount_save;
75 dentry_save = nd->path.dentry;
76 vfsmount_save = nd->path.mnt;
77 nd->path.dentry = lower_dentry;
78 nd->path.mnt = lower_mnt;
79 rc = vfs_create(lower_dir_inode, lower_dentry, mode, nd);
80 nd->path.dentry = dentry_save;
81 nd->path.mnt = vfsmount_save;
87 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
88 * @ecryptfs_dentry: New file's dentry in ecryptfs
89 * @mode: The mode of the new file
90 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
92 * Creates the underlying file and the eCryptfs inode which will link to
93 * it. It will also update the eCryptfs directory inode to mimic the
94 * stat of the lower directory inode.
96 * Returns zero on success; non-zero on error condition
99 ecryptfs_do_create(struct inode *directory_inode,
100 struct dentry *ecryptfs_dentry, int mode,
101 struct nameidata *nd)
104 struct dentry *lower_dentry;
105 struct dentry *lower_dir_dentry;
107 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
108 lower_dir_dentry = lock_parent(lower_dentry);
109 if (IS_ERR(lower_dir_dentry)) {
110 ecryptfs_printk(KERN_ERR, "Error locking directory of "
112 rc = PTR_ERR(lower_dir_dentry);
115 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
116 ecryptfs_dentry, mode, nd);
118 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
119 "rc = [%d]\n", __func__, rc);
122 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
123 directory_inode->i_sb, 0);
125 ecryptfs_printk(KERN_ERR, "Failure in ecryptfs_interpose\n");
128 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
129 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
131 unlock_dir(lower_dir_dentry);
138 * @ecryptfs_dentry: the eCryptfs dentry
140 * This is the code which will grow the file to its correct size.
142 static int grow_file(struct dentry *ecryptfs_dentry)
144 struct inode *ecryptfs_inode = ecryptfs_dentry->d_inode;
145 struct file fake_file;
146 struct ecryptfs_file_info tmp_file_info;
147 char zero_virt[] = { 0x00 };
150 memset(&fake_file, 0, sizeof(fake_file));
151 fake_file.f_path.dentry = ecryptfs_dentry;
152 memset(&tmp_file_info, 0, sizeof(tmp_file_info));
153 ecryptfs_set_file_private(&fake_file, &tmp_file_info);
154 ecryptfs_set_file_lower(
156 ecryptfs_inode_to_private(ecryptfs_inode)->lower_file);
157 rc = ecryptfs_write(&fake_file, zero_virt, 0, 1);
158 i_size_write(ecryptfs_inode, 0);
159 rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode);
160 ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat.flags |=
166 * ecryptfs_initialize_file
168 * Cause the file to be changed from a basic empty file to an ecryptfs
169 * file with a header and first data page.
171 * Returns zero on success
173 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry)
175 struct ecryptfs_crypt_stat *crypt_stat =
176 &ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->crypt_stat;
179 if (S_ISDIR(ecryptfs_dentry->d_inode->i_mode)) {
180 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
181 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
184 crypt_stat->flags |= ECRYPTFS_NEW_FILE;
185 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
186 rc = ecryptfs_new_file_context(ecryptfs_dentry);
188 ecryptfs_printk(KERN_ERR, "Error creating new file "
189 "context; rc = [%d]\n", rc);
192 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
193 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
195 printk(KERN_ERR "%s: Error attempting to initialize "
196 "the persistent file for the dentry with name "
197 "[%s]; rc = [%d]\n", __func__,
198 ecryptfs_dentry->d_name.name, rc);
202 rc = ecryptfs_write_metadata(ecryptfs_dentry);
204 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
207 rc = grow_file(ecryptfs_dentry);
209 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
216 * @dir: The inode of the directory in which to create the file.
217 * @dentry: The eCryptfs dentry
218 * @mode: The mode of the new file.
221 * Creates a new file.
223 * Returns zero on success; non-zero on error condition
226 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
227 int mode, struct nameidata *nd)
231 /* ecryptfs_do_create() calls ecryptfs_interpose() */
232 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
234 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
235 "lower filesystem\n");
238 /* At this point, a file exists on "disk"; we need to make sure
239 * that this on disk file is prepared to be an ecryptfs file */
240 rc = ecryptfs_initialize_file(ecryptfs_dentry);
246 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
248 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
249 struct dentry *lower_dentry,
250 struct inode *ecryptfs_dir_inode,
251 struct nameidata *ecryptfs_nd)
253 struct dentry *lower_dir_dentry;
254 struct vfsmount *lower_mnt;
255 struct inode *lower_inode;
256 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
257 struct ecryptfs_crypt_stat *crypt_stat;
258 char *page_virt = NULL;
262 lower_dir_dentry = lower_dentry->d_parent;
263 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
264 ecryptfs_dentry->d_parent));
265 lower_inode = lower_dentry->d_inode;
266 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
267 BUG_ON(!atomic_read(&lower_dentry->d_count));
268 ecryptfs_set_dentry_private(ecryptfs_dentry,
269 kmem_cache_alloc(ecryptfs_dentry_info_cache,
271 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
273 printk(KERN_ERR "%s: Out of memory whilst attempting "
274 "to allocate ecryptfs_dentry_info struct\n",
278 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
279 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
280 if (!lower_dentry->d_inode) {
281 /* We want to add because we couldn't find in lower */
282 d_add(ecryptfs_dentry, NULL);
285 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
286 ecryptfs_dir_inode->i_sb,
287 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
289 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
293 if (S_ISDIR(lower_inode->i_mode))
295 if (S_ISLNK(lower_inode->i_mode))
297 if (special_file(lower_inode->i_mode))
301 /* Released in this function */
302 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
304 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
309 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
310 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
312 printk(KERN_ERR "%s: Error attempting to initialize "
313 "the persistent file for the dentry with name "
314 "[%s]; rc = [%d]\n", __func__,
315 ecryptfs_dentry->d_name.name, rc);
319 crypt_stat = &ecryptfs_inode_to_private(
320 ecryptfs_dentry->d_inode)->crypt_stat;
321 /* TODO: lock for crypt_stat comparison */
322 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
323 ecryptfs_set_default_sizes(crypt_stat);
324 rc = ecryptfs_read_and_validate_header_region(page_virt,
325 ecryptfs_dentry->d_inode);
327 memset(page_virt, 0, PAGE_CACHE_SIZE);
328 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
334 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
336 mount_crypt_stat = &ecryptfs_superblock_to_private(
337 ecryptfs_dentry->d_sb)->mount_crypt_stat;
338 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
339 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
340 file_size = (crypt_stat->metadata_size
341 + i_size_read(lower_dentry->d_inode));
343 file_size = i_size_read(lower_dentry->d_inode);
345 file_size = get_unaligned_be64(page_virt);
347 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
349 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
353 d_drop(ecryptfs_dentry);
360 * @ecryptfs_dir_inode: The eCryptfs directory inode
361 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
362 * @ecryptfs_nd: nameidata; may be NULL
364 * Find a file on disk. If the file does not exist, then we'll add it to the
365 * dentry cache and continue on to read it from the disk.
367 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
368 struct dentry *ecryptfs_dentry,
369 struct nameidata *ecryptfs_nd)
371 char *encrypted_and_encoded_name = NULL;
372 size_t encrypted_and_encoded_name_size;
373 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
374 struct dentry *lower_dir_dentry, *lower_dentry;
377 ecryptfs_dentry->d_op = &ecryptfs_dops;
378 if ((ecryptfs_dentry->d_name.len == 1
379 && !strcmp(ecryptfs_dentry->d_name.name, "."))
380 || (ecryptfs_dentry->d_name.len == 2
381 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
384 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
385 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
386 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
388 ecryptfs_dentry->d_name.len);
389 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
390 if (IS_ERR(lower_dentry)) {
391 rc = PTR_ERR(lower_dentry);
392 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
393 "[%d] on lower_dentry = [%s]\n", __func__, rc,
394 encrypted_and_encoded_name);
397 if (lower_dentry->d_inode)
398 goto lookup_and_interpose;
399 mount_crypt_stat = &ecryptfs_superblock_to_private(
400 ecryptfs_dentry->d_sb)->mount_crypt_stat;
401 if (!(mount_crypt_stat
402 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
403 goto lookup_and_interpose;
405 rc = ecryptfs_encrypt_and_encode_filename(
406 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
407 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
408 ecryptfs_dentry->d_name.len);
410 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
411 "filename; rc = [%d]\n", __func__, rc);
414 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
415 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
417 encrypted_and_encoded_name_size - 1);
418 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
419 if (IS_ERR(lower_dentry)) {
420 rc = PTR_ERR(lower_dentry);
421 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
422 "[%d] on lower_dentry = [%s]\n", __func__, rc,
423 encrypted_and_encoded_name);
426 lookup_and_interpose:
427 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
432 d_drop(ecryptfs_dentry);
434 kfree(encrypted_and_encoded_name);
438 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
439 struct dentry *new_dentry)
441 struct dentry *lower_old_dentry;
442 struct dentry *lower_new_dentry;
443 struct dentry *lower_dir_dentry;
447 file_size_save = i_size_read(old_dentry->d_inode);
448 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
449 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
450 dget(lower_old_dentry);
451 dget(lower_new_dentry);
452 lower_dir_dentry = lock_parent(lower_new_dentry);
453 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
455 if (rc || !lower_new_dentry->d_inode)
457 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
460 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
461 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
462 old_dentry->d_inode->i_nlink =
463 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
464 i_size_write(new_dentry->d_inode, file_size_save);
466 unlock_dir(lower_dir_dentry);
467 dput(lower_new_dentry);
468 dput(lower_old_dentry);
472 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
475 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
476 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
477 struct dentry *lower_dir_dentry;
480 lower_dir_dentry = lock_parent(lower_dentry);
481 rc = vfs_unlink(lower_dir_inode, lower_dentry);
483 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
486 fsstack_copy_attr_times(dir, lower_dir_inode);
487 dentry->d_inode->i_nlink =
488 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
489 dentry->d_inode->i_ctime = dir->i_ctime;
492 unlock_dir(lower_dir_dentry);
497 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
501 struct dentry *lower_dentry;
502 struct dentry *lower_dir_dentry;
503 char *encoded_symname;
504 size_t encoded_symlen;
505 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
507 lower_dentry = ecryptfs_dentry_to_lower(dentry);
509 lower_dir_dentry = lock_parent(lower_dentry);
510 mount_crypt_stat = &ecryptfs_superblock_to_private(
511 dir->i_sb)->mount_crypt_stat;
512 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
515 mount_crypt_stat, symname,
519 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
521 kfree(encoded_symname);
522 if (rc || !lower_dentry->d_inode)
524 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
527 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
528 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
530 unlock_dir(lower_dir_dentry);
532 if (!dentry->d_inode)
537 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
540 struct dentry *lower_dentry;
541 struct dentry *lower_dir_dentry;
543 lower_dentry = ecryptfs_dentry_to_lower(dentry);
544 lower_dir_dentry = lock_parent(lower_dentry);
545 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
546 if (rc || !lower_dentry->d_inode)
548 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
551 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
552 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
553 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
555 unlock_dir(lower_dir_dentry);
556 if (!dentry->d_inode)
561 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
563 struct dentry *lower_dentry;
564 struct dentry *lower_dir_dentry;
567 lower_dentry = ecryptfs_dentry_to_lower(dentry);
569 lower_dir_dentry = lock_parent(lower_dentry);
571 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
574 d_delete(lower_dentry);
575 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
576 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
577 unlock_dir(lower_dir_dentry);
585 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
588 struct dentry *lower_dentry;
589 struct dentry *lower_dir_dentry;
591 lower_dentry = ecryptfs_dentry_to_lower(dentry);
592 lower_dir_dentry = lock_parent(lower_dentry);
593 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
594 if (rc || !lower_dentry->d_inode)
596 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
599 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
600 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
602 unlock_dir(lower_dir_dentry);
603 if (!dentry->d_inode)
609 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
610 struct inode *new_dir, struct dentry *new_dentry)
613 struct dentry *lower_old_dentry;
614 struct dentry *lower_new_dentry;
615 struct dentry *lower_old_dir_dentry;
616 struct dentry *lower_new_dir_dentry;
617 struct dentry *trap = NULL;
619 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
620 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
621 dget(lower_old_dentry);
622 dget(lower_new_dentry);
623 lower_old_dir_dentry = dget_parent(lower_old_dentry);
624 lower_new_dir_dentry = dget_parent(lower_new_dentry);
625 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
626 /* source should not be ancestor of target */
627 if (trap == lower_old_dentry) {
631 /* target should not be ancestor of source */
632 if (trap == lower_new_dentry) {
636 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
637 lower_new_dir_dentry->d_inode, lower_new_dentry);
640 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
641 if (new_dir != old_dir)
642 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
644 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
645 dput(lower_new_dentry->d_parent);
646 dput(lower_old_dentry->d_parent);
647 dput(lower_new_dentry);
648 dput(lower_old_dentry);
652 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
655 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
657 size_t lower_bufsiz = PATH_MAX;
661 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
668 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
669 (char __user *)lower_buf,
675 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
676 lower_buf, lower_bufsiz);
683 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
686 size_t kbufsiz, copied;
689 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
692 copied = min_t(size_t, bufsiz, kbufsiz);
693 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
695 fsstack_copy_attr_atime(dentry->d_inode,
696 ecryptfs_dentry_to_lower(dentry)->d_inode);
701 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
704 int len = PAGE_SIZE, rc;
707 /* Released in ecryptfs_put_link(); only release here on error */
708 buf = kmalloc(len, GFP_KERNEL);
710 buf = ERR_PTR(-ENOMEM);
715 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
723 nd_set_link(nd, buf);
728 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
730 char *buf = nd_get_link(nd);
738 * upper_size_to_lower_size
739 * @crypt_stat: Crypt_stat associated with file
740 * @upper_size: Size of the upper file
742 * Calculate the required size of the lower file based on the
743 * specified size of the upper file. This calculation is based on the
744 * number of headers in the underlying file and the extent size.
746 * Returns Calculated size of the lower file.
749 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
754 lower_size = ecryptfs_lower_header_size(crypt_stat);
755 if (upper_size != 0) {
758 num_extents = upper_size >> crypt_stat->extent_shift;
759 if (upper_size & ~crypt_stat->extent_mask)
761 lower_size += (num_extents * crypt_stat->extent_size);
768 * @dentry: The ecryptfs layer dentry
769 * @ia: Address of the ecryptfs inode's attributes
770 * @lower_ia: Address of the lower inode's attributes
772 * Function to handle truncations modifying the size of the file. Note
773 * that the file sizes are interpolated. When expanding, we are simply
774 * writing strings of 0's out. When truncating, we truncate the upper
775 * inode and update the lower_ia according to the page index
776 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
777 * the caller must use lower_ia in a call to notify_change() to perform
778 * the truncation of the lower inode.
780 * Returns zero on success; non-zero otherwise
782 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
783 struct iattr *lower_ia)
786 struct inode *inode = dentry->d_inode;
787 struct dentry *lower_dentry;
788 struct file fake_ecryptfs_file;
789 struct ecryptfs_crypt_stat *crypt_stat;
790 loff_t i_size = i_size_read(inode);
791 loff_t lower_size_before_truncate;
792 loff_t lower_size_after_truncate;
794 if (unlikely((ia->ia_size == i_size))) {
795 lower_ia->ia_valid &= ~ATTR_SIZE;
798 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
799 /* Set up a fake ecryptfs file, this is used to interface with
800 * the file in the underlying filesystem so that the
801 * truncation has an effect there as well. */
802 memset(&fake_ecryptfs_file, 0, sizeof(fake_ecryptfs_file));
803 fake_ecryptfs_file.f_path.dentry = dentry;
804 /* Released at out_free: label */
805 ecryptfs_set_file_private(&fake_ecryptfs_file,
806 kmem_cache_alloc(ecryptfs_file_info_cache,
808 if (unlikely(!ecryptfs_file_to_private(&fake_ecryptfs_file))) {
812 lower_dentry = ecryptfs_dentry_to_lower(dentry);
813 ecryptfs_set_file_lower(
815 ecryptfs_inode_to_private(dentry->d_inode)->lower_file);
816 /* Switch on growing or shrinking file */
817 if (ia->ia_size > i_size) {
818 char zero[] = { 0x00 };
820 lower_ia->ia_valid &= ~ATTR_SIZE;
821 /* Write a single 0 at the last position of the file;
822 * this triggers code that will fill in 0's throughout
823 * the intermediate portion of the previous end of the
824 * file and the new and of the file */
825 rc = ecryptfs_write(&fake_ecryptfs_file, zero,
826 (ia->ia_size - 1), 1);
827 } else { /* ia->ia_size < i_size_read(inode) */
828 /* We're chopping off all the pages down to the page
829 * in which ia->ia_size is located. Fill in the end of
830 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
831 * PAGE_CACHE_SIZE with zeros. */
832 size_t num_zeros = (PAGE_CACHE_SIZE
833 - (ia->ia_size & ~PAGE_CACHE_MASK));
835 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
836 rc = vmtruncate(inode, ia->ia_size);
839 lower_ia->ia_size = ia->ia_size;
840 lower_ia->ia_valid |= ATTR_SIZE;
846 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
851 rc = ecryptfs_write(&fake_ecryptfs_file, zeros_virt,
852 ia->ia_size, num_zeros);
855 printk(KERN_ERR "Error attempting to zero out "
856 "the remainder of the end page on "
857 "reducing truncate; rc = [%d]\n", rc);
861 vmtruncate(inode, ia->ia_size);
862 rc = ecryptfs_write_inode_size_to_metadata(inode);
864 printk(KERN_ERR "Problem with "
865 "ecryptfs_write_inode_size_to_metadata; "
869 /* We are reducing the size of the ecryptfs file, and need to
870 * know if we need to reduce the size of the lower file. */
871 lower_size_before_truncate =
872 upper_size_to_lower_size(crypt_stat, i_size);
873 lower_size_after_truncate =
874 upper_size_to_lower_size(crypt_stat, ia->ia_size);
875 if (lower_size_after_truncate < lower_size_before_truncate) {
876 lower_ia->ia_size = lower_size_after_truncate;
877 lower_ia->ia_valid |= ATTR_SIZE;
879 lower_ia->ia_valid &= ~ATTR_SIZE;
882 if (ecryptfs_file_to_private(&fake_ecryptfs_file))
883 kmem_cache_free(ecryptfs_file_info_cache,
884 ecryptfs_file_to_private(&fake_ecryptfs_file));
891 * @dentry: The ecryptfs layer dentry
892 * @new_length: The length to expand the file to
894 * Simple function that handles the truncation of an eCryptfs inode and
895 * its corresponding lower inode.
897 * Returns zero on success; non-zero otherwise
899 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
901 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
902 struct iattr lower_ia = { .ia_valid = 0 };
905 rc = truncate_upper(dentry, &ia, &lower_ia);
906 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
907 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
909 mutex_lock(&lower_dentry->d_inode->i_mutex);
910 rc = notify_change(lower_dentry, &lower_ia);
911 mutex_unlock(&lower_dentry->d_inode->i_mutex);
917 ecryptfs_permission(struct inode *inode, int mask)
919 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
924 * @dentry: dentry handle to the inode to modify
925 * @ia: Structure with flags of what to change and values
927 * Updates the metadata of an inode. If the update is to the size
928 * i.e. truncation, then ecryptfs_truncate will handle the size modification
929 * of both the ecryptfs inode and the lower inode.
931 * All other metadata changes will be passed right to the lower filesystem,
932 * and we will just update our inode to look like the lower.
934 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
937 struct dentry *lower_dentry;
938 struct iattr lower_ia;
940 struct inode *lower_inode;
941 struct ecryptfs_crypt_stat *crypt_stat;
943 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
944 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
945 ecryptfs_init_crypt_stat(crypt_stat);
946 inode = dentry->d_inode;
947 lower_inode = ecryptfs_inode_to_lower(inode);
948 lower_dentry = ecryptfs_dentry_to_lower(dentry);
949 mutex_lock(&crypt_stat->cs_mutex);
950 if (S_ISDIR(dentry->d_inode->i_mode))
951 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
952 else if (S_ISREG(dentry->d_inode->i_mode)
953 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
954 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
955 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
957 mount_crypt_stat = &ecryptfs_superblock_to_private(
958 dentry->d_sb)->mount_crypt_stat;
959 rc = ecryptfs_read_metadata(dentry);
961 if (!(mount_crypt_stat->flags
962 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
964 printk(KERN_WARNING "Either the lower file "
965 "is not in a valid eCryptfs format, "
966 "or the key could not be retrieved. "
967 "Plaintext passthrough mode is not "
968 "enabled; returning -EIO\n");
969 mutex_unlock(&crypt_stat->cs_mutex);
973 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
976 mutex_unlock(&crypt_stat->cs_mutex);
977 memcpy(&lower_ia, ia, sizeof(lower_ia));
978 if (ia->ia_valid & ATTR_FILE)
979 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
980 if (ia->ia_valid & ATTR_SIZE) {
981 rc = truncate_upper(dentry, ia, &lower_ia);
987 * mode change is for clearing setuid/setgid bits. Allow lower fs
988 * to interpret this in its own way.
990 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
991 lower_ia.ia_valid &= ~ATTR_MODE;
993 mutex_lock(&lower_dentry->d_inode->i_mutex);
994 rc = notify_change(lower_dentry, &lower_ia);
995 mutex_unlock(&lower_dentry->d_inode->i_mutex);
997 fsstack_copy_attr_all(inode, lower_inode);
1001 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1004 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1007 mount_crypt_stat = &ecryptfs_superblock_to_private(
1008 dentry->d_sb)->mount_crypt_stat;
1009 generic_fillattr(dentry->d_inode, stat);
1010 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1014 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1017 stat->size = targetsiz;
1023 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1026 struct kstat lower_stat;
1029 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1030 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1032 generic_fillattr(dentry->d_inode, stat);
1033 stat->blocks = lower_stat.blocks;
1039 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1040 size_t size, int flags)
1043 struct dentry *lower_dentry;
1045 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1046 if (!lower_dentry->d_inode->i_op->setxattr) {
1050 mutex_lock(&lower_dentry->d_inode->i_mutex);
1051 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry, name, value,
1053 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1059 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1060 void *value, size_t size)
1064 if (!lower_dentry->d_inode->i_op->getxattr) {
1068 mutex_lock(&lower_dentry->d_inode->i_mutex);
1069 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1071 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1077 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1080 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1085 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1088 struct dentry *lower_dentry;
1090 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1091 if (!lower_dentry->d_inode->i_op->listxattr) {
1095 mutex_lock(&lower_dentry->d_inode->i_mutex);
1096 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1097 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1102 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1105 struct dentry *lower_dentry;
1107 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1108 if (!lower_dentry->d_inode->i_op->removexattr) {
1112 mutex_lock(&lower_dentry->d_inode->i_mutex);
1113 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1114 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1119 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1121 if ((ecryptfs_inode_to_lower(inode)
1122 == (struct inode *)candidate_lower_inode))
1128 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1130 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1134 const struct inode_operations ecryptfs_symlink_iops = {
1135 .readlink = ecryptfs_readlink,
1136 .follow_link = ecryptfs_follow_link,
1137 .put_link = ecryptfs_put_link,
1138 .permission = ecryptfs_permission,
1139 .setattr = ecryptfs_setattr,
1140 .getattr = ecryptfs_getattr_link,
1141 .setxattr = ecryptfs_setxattr,
1142 .getxattr = ecryptfs_getxattr,
1143 .listxattr = ecryptfs_listxattr,
1144 .removexattr = ecryptfs_removexattr
1147 const struct inode_operations ecryptfs_dir_iops = {
1148 .create = ecryptfs_create,
1149 .lookup = ecryptfs_lookup,
1150 .link = ecryptfs_link,
1151 .unlink = ecryptfs_unlink,
1152 .symlink = ecryptfs_symlink,
1153 .mkdir = ecryptfs_mkdir,
1154 .rmdir = ecryptfs_rmdir,
1155 .mknod = ecryptfs_mknod,
1156 .rename = ecryptfs_rename,
1157 .permission = ecryptfs_permission,
1158 .setattr = ecryptfs_setattr,
1159 .setxattr = ecryptfs_setxattr,
1160 .getxattr = ecryptfs_getxattr,
1161 .listxattr = ecryptfs_listxattr,
1162 .removexattr = ecryptfs_removexattr
1165 const struct inode_operations ecryptfs_main_iops = {
1166 .permission = ecryptfs_permission,
1167 .setattr = ecryptfs_setattr,
1168 .getattr = ecryptfs_getattr,
1169 .setxattr = ecryptfs_setxattr,
1170 .getxattr = ecryptfs_getxattr,
1171 .listxattr = ecryptfs_listxattr,
1172 .removexattr = ecryptfs_removexattr