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 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
189 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
191 printk(KERN_ERR "%s: Error attempting to initialize "
192 "the persistent file for the dentry with name "
193 "[%s]; rc = [%d]\n", __func__,
194 ecryptfs_dentry->d_name.name, rc);
198 rc = ecryptfs_write_metadata(ecryptfs_dentry);
200 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
203 rc = grow_file(ecryptfs_dentry);
205 printk(KERN_ERR "Error growing file; rc = [%d]\n", rc);
212 * @dir: The inode of the directory in which to create the file.
213 * @dentry: The eCryptfs dentry
214 * @mode: The mode of the new file.
217 * Creates a new file.
219 * Returns zero on success; non-zero on error condition
222 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
223 int mode, struct nameidata *nd)
227 /* ecryptfs_do_create() calls ecryptfs_interpose() */
228 rc = ecryptfs_do_create(directory_inode, ecryptfs_dentry, mode, nd);
230 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
231 "lower filesystem\n");
234 /* At this point, a file exists on "disk"; we need to make sure
235 * that this on disk file is prepared to be an ecryptfs file */
236 rc = ecryptfs_initialize_file(ecryptfs_dentry);
242 * ecryptfs_lookup_and_interpose_lower - Perform a lookup
244 int ecryptfs_lookup_and_interpose_lower(struct dentry *ecryptfs_dentry,
245 struct dentry *lower_dentry,
246 struct inode *ecryptfs_dir_inode,
247 struct nameidata *ecryptfs_nd)
249 struct dentry *lower_dir_dentry;
250 struct vfsmount *lower_mnt;
251 struct inode *lower_inode;
252 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
253 struct ecryptfs_crypt_stat *crypt_stat;
254 char *page_virt = NULL;
258 lower_dir_dentry = lower_dentry->d_parent;
259 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
260 ecryptfs_dentry->d_parent));
261 lower_inode = lower_dentry->d_inode;
262 fsstack_copy_attr_atime(ecryptfs_dir_inode, lower_dir_dentry->d_inode);
263 BUG_ON(!lower_dentry->d_count);
264 ecryptfs_set_dentry_private(ecryptfs_dentry,
265 kmem_cache_alloc(ecryptfs_dentry_info_cache,
267 if (!ecryptfs_dentry_to_private(ecryptfs_dentry)) {
269 printk(KERN_ERR "%s: Out of memory whilst attempting "
270 "to allocate ecryptfs_dentry_info struct\n",
274 ecryptfs_set_dentry_lower(ecryptfs_dentry, lower_dentry);
275 ecryptfs_set_dentry_lower_mnt(ecryptfs_dentry, lower_mnt);
276 if (!lower_dentry->d_inode) {
277 /* We want to add because we couldn't find in lower */
278 d_add(ecryptfs_dentry, NULL);
281 rc = ecryptfs_interpose(lower_dentry, ecryptfs_dentry,
282 ecryptfs_dir_inode->i_sb,
283 ECRYPTFS_INTERPOSE_FLAG_D_ADD);
285 printk(KERN_ERR "%s: Error interposing; rc = [%d]\n",
289 if (S_ISDIR(lower_inode->i_mode))
291 if (S_ISLNK(lower_inode->i_mode))
293 if (special_file(lower_inode->i_mode))
297 /* Released in this function */
298 page_virt = kmem_cache_zalloc(ecryptfs_header_cache_2, GFP_USER);
300 printk(KERN_ERR "%s: Cannot kmem_cache_zalloc() a page\n",
305 if (!ecryptfs_inode_to_private(ecryptfs_dentry->d_inode)->lower_file) {
306 rc = ecryptfs_init_persistent_file(ecryptfs_dentry);
308 printk(KERN_ERR "%s: Error attempting to initialize "
309 "the persistent file for the dentry with name "
310 "[%s]; rc = [%d]\n", __func__,
311 ecryptfs_dentry->d_name.name, rc);
315 crypt_stat = &ecryptfs_inode_to_private(
316 ecryptfs_dentry->d_inode)->crypt_stat;
317 /* TODO: lock for crypt_stat comparison */
318 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
319 ecryptfs_set_default_sizes(crypt_stat);
320 rc = ecryptfs_read_and_validate_header_region(page_virt,
321 ecryptfs_dentry->d_inode);
323 memset(page_virt, 0, PAGE_CACHE_SIZE);
324 rc = ecryptfs_read_and_validate_xattr_region(page_virt,
330 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
332 mount_crypt_stat = &ecryptfs_superblock_to_private(
333 ecryptfs_dentry->d_sb)->mount_crypt_stat;
334 if (mount_crypt_stat->flags & ECRYPTFS_ENCRYPTED_VIEW_ENABLED) {
335 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
336 file_size = (crypt_stat->metadata_size
337 + i_size_read(lower_dentry->d_inode));
339 file_size = i_size_read(lower_dentry->d_inode);
341 file_size = get_unaligned_be64(page_virt);
343 i_size_write(ecryptfs_dentry->d_inode, (loff_t)file_size);
345 kmem_cache_free(ecryptfs_header_cache_2, page_virt);
350 d_drop(ecryptfs_dentry);
356 * ecryptfs_new_lower_dentry
357 * @name: The name of the new dentry.
358 * @lower_dir_dentry: Parent directory of the new dentry.
359 * @nd: nameidata from last lookup.
361 * Create a new dentry or get it from lower parent dir.
363 static struct dentry *
364 ecryptfs_new_lower_dentry(struct qstr *name, struct dentry *lower_dir_dentry,
365 struct nameidata *nd)
367 struct dentry *new_dentry;
369 struct inode *lower_dir_inode;
371 lower_dir_inode = lower_dir_dentry->d_inode;
373 tmp = d_alloc(lower_dir_dentry, name);
375 return ERR_PTR(-ENOMEM);
377 mutex_lock(&lower_dir_inode->i_mutex);
378 new_dentry = lower_dir_inode->i_op->lookup(lower_dir_inode, tmp, nd);
379 mutex_unlock(&lower_dir_inode->i_mutex);
391 * ecryptfs_lookup_one_lower
392 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
393 * @lower_dir_dentry: lower parent directory
394 * @name: lower file name
396 * Get the lower dentry from vfs. If lower dentry does not exist yet,
399 static struct dentry *
400 ecryptfs_lookup_one_lower(struct dentry *ecryptfs_dentry,
401 struct dentry *lower_dir_dentry, struct qstr *name)
404 struct vfsmount *lower_mnt;
407 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(
408 ecryptfs_dentry->d_parent));
409 err = vfs_path_lookup(lower_dir_dentry, lower_mnt, name->name , 0, &nd);
413 /* we dont need the mount */
415 return nd.path.dentry;
420 /* create a new lower dentry */
421 return ecryptfs_new_lower_dentry(name, lower_dir_dentry, &nd);
426 * @ecryptfs_dir_inode: The eCryptfs directory inode
427 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
428 * @ecryptfs_nd: nameidata; may be NULL
430 * Find a file on disk. If the file does not exist, then we'll add it to the
431 * dentry cache and continue on to read it from the disk.
433 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
434 struct dentry *ecryptfs_dentry,
435 struct nameidata *ecryptfs_nd)
437 char *encrypted_and_encoded_name = NULL;
438 size_t encrypted_and_encoded_name_size;
439 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
440 struct dentry *lower_dir_dentry, *lower_dentry;
441 struct qstr lower_name;
444 if ((ecryptfs_dentry->d_name.len == 1
445 && !strcmp(ecryptfs_dentry->d_name.name, "."))
446 || (ecryptfs_dentry->d_name.len == 2
447 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
450 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
451 lower_name.name = ecryptfs_dentry->d_name.name;
452 lower_name.len = ecryptfs_dentry->d_name.len;
453 lower_name.hash = ecryptfs_dentry->d_name.hash;
454 if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
455 rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
456 lower_dir_dentry->d_inode, &lower_name);
460 lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
461 lower_dir_dentry, &lower_name);
462 if (IS_ERR(lower_dentry)) {
463 rc = PTR_ERR(lower_dentry);
464 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
465 "[%d] on lower_dentry = [%s]\n", __func__, rc,
466 encrypted_and_encoded_name);
469 if (lower_dentry->d_inode)
470 goto lookup_and_interpose;
471 mount_crypt_stat = &ecryptfs_superblock_to_private(
472 ecryptfs_dentry->d_sb)->mount_crypt_stat;
473 if (!(mount_crypt_stat
474 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
475 goto lookup_and_interpose;
477 rc = ecryptfs_encrypt_and_encode_filename(
478 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
479 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
480 ecryptfs_dentry->d_name.len);
482 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
483 "filename; rc = [%d]\n", __func__, rc);
486 lower_name.name = encrypted_and_encoded_name;
487 lower_name.len = encrypted_and_encoded_name_size;
488 lower_name.hash = full_name_hash(lower_name.name, lower_name.len);
489 if (lower_dir_dentry->d_op && lower_dir_dentry->d_op->d_hash) {
490 rc = lower_dir_dentry->d_op->d_hash(lower_dir_dentry,
491 lower_dir_dentry->d_inode, &lower_name);
495 lower_dentry = ecryptfs_lookup_one_lower(ecryptfs_dentry,
496 lower_dir_dentry, &lower_name);
497 if (IS_ERR(lower_dentry)) {
498 rc = PTR_ERR(lower_dentry);
499 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_lower() returned "
500 "[%d] on lower_dentry = [%s]\n", __func__, rc,
501 encrypted_and_encoded_name);
504 lookup_and_interpose:
505 rc = ecryptfs_lookup_and_interpose_lower(ecryptfs_dentry, lower_dentry,
510 d_drop(ecryptfs_dentry);
512 kfree(encrypted_and_encoded_name);
516 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
517 struct dentry *new_dentry)
519 struct dentry *lower_old_dentry;
520 struct dentry *lower_new_dentry;
521 struct dentry *lower_dir_dentry;
525 file_size_save = i_size_read(old_dentry->d_inode);
526 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
527 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
528 dget(lower_old_dentry);
529 dget(lower_new_dentry);
530 lower_dir_dentry = lock_parent(lower_new_dentry);
531 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
533 if (rc || !lower_new_dentry->d_inode)
535 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb, 0);
538 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
539 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
540 old_dentry->d_inode->i_nlink =
541 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink;
542 i_size_write(new_dentry->d_inode, file_size_save);
544 unlock_dir(lower_dir_dentry);
545 dput(lower_new_dentry);
546 dput(lower_old_dentry);
550 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
553 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
554 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
555 struct dentry *lower_dir_dentry;
558 lower_dir_dentry = lock_parent(lower_dentry);
559 rc = vfs_unlink(lower_dir_inode, lower_dentry);
561 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
564 fsstack_copy_attr_times(dir, lower_dir_inode);
565 dentry->d_inode->i_nlink =
566 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink;
567 dentry->d_inode->i_ctime = dir->i_ctime;
570 unlock_dir(lower_dir_dentry);
575 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
579 struct dentry *lower_dentry;
580 struct dentry *lower_dir_dentry;
581 char *encoded_symname;
582 size_t encoded_symlen;
583 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
585 lower_dentry = ecryptfs_dentry_to_lower(dentry);
587 lower_dir_dentry = lock_parent(lower_dentry);
588 mount_crypt_stat = &ecryptfs_superblock_to_private(
589 dir->i_sb)->mount_crypt_stat;
590 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
593 mount_crypt_stat, symname,
597 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
599 kfree(encoded_symname);
600 if (rc || !lower_dentry->d_inode)
602 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
605 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
606 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
608 unlock_dir(lower_dir_dentry);
610 if (!dentry->d_inode)
615 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
618 struct dentry *lower_dentry;
619 struct dentry *lower_dir_dentry;
621 lower_dentry = ecryptfs_dentry_to_lower(dentry);
622 lower_dir_dentry = lock_parent(lower_dentry);
623 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
624 if (rc || !lower_dentry->d_inode)
626 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
629 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
630 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
631 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
633 unlock_dir(lower_dir_dentry);
634 if (!dentry->d_inode)
639 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
641 struct dentry *lower_dentry;
642 struct dentry *lower_dir_dentry;
645 lower_dentry = ecryptfs_dentry_to_lower(dentry);
647 lower_dir_dentry = lock_parent(lower_dentry);
649 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
652 d_delete(lower_dentry);
653 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
654 dir->i_nlink = lower_dir_dentry->d_inode->i_nlink;
655 unlock_dir(lower_dir_dentry);
663 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
666 struct dentry *lower_dentry;
667 struct dentry *lower_dir_dentry;
669 lower_dentry = ecryptfs_dentry_to_lower(dentry);
670 lower_dir_dentry = lock_parent(lower_dentry);
671 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
672 if (rc || !lower_dentry->d_inode)
674 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb, 0);
677 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
678 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
680 unlock_dir(lower_dir_dentry);
681 if (!dentry->d_inode)
687 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
688 struct inode *new_dir, struct dentry *new_dentry)
691 struct dentry *lower_old_dentry;
692 struct dentry *lower_new_dentry;
693 struct dentry *lower_old_dir_dentry;
694 struct dentry *lower_new_dir_dentry;
695 struct dentry *trap = NULL;
697 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
698 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
699 dget(lower_old_dentry);
700 dget(lower_new_dentry);
701 lower_old_dir_dentry = dget_parent(lower_old_dentry);
702 lower_new_dir_dentry = dget_parent(lower_new_dentry);
703 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
704 /* source should not be ancestor of target */
705 if (trap == lower_old_dentry) {
709 /* target should not be ancestor of source */
710 if (trap == lower_new_dentry) {
714 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
715 lower_new_dir_dentry->d_inode, lower_new_dentry);
718 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
719 if (new_dir != old_dir)
720 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
722 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
723 dput(lower_new_dentry->d_parent);
724 dput(lower_old_dentry->d_parent);
725 dput(lower_new_dentry);
726 dput(lower_old_dentry);
730 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
733 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
735 size_t lower_bufsiz = PATH_MAX;
739 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
746 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
747 (char __user *)lower_buf,
753 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
754 lower_buf, lower_bufsiz);
761 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
764 size_t kbufsiz, copied;
767 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
770 copied = min_t(size_t, bufsiz, kbufsiz);
771 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
773 fsstack_copy_attr_atime(dentry->d_inode,
774 ecryptfs_dentry_to_lower(dentry)->d_inode);
779 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
782 int len = PAGE_SIZE, rc;
785 /* Released in ecryptfs_put_link(); only release here on error */
786 buf = kmalloc(len, GFP_KERNEL);
788 buf = ERR_PTR(-ENOMEM);
793 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
801 nd_set_link(nd, buf);
806 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
808 char *buf = nd_get_link(nd);
816 * upper_size_to_lower_size
817 * @crypt_stat: Crypt_stat associated with file
818 * @upper_size: Size of the upper file
820 * Calculate the required size of the lower file based on the
821 * specified size of the upper file. This calculation is based on the
822 * number of headers in the underlying file and the extent size.
824 * Returns Calculated size of the lower file.
827 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
832 lower_size = ecryptfs_lower_header_size(crypt_stat);
833 if (upper_size != 0) {
836 num_extents = upper_size >> crypt_stat->extent_shift;
837 if (upper_size & ~crypt_stat->extent_mask)
839 lower_size += (num_extents * crypt_stat->extent_size);
846 * @dentry: The ecryptfs layer dentry
847 * @ia: Address of the ecryptfs inode's attributes
848 * @lower_ia: Address of the lower inode's attributes
850 * Function to handle truncations modifying the size of the file. Note
851 * that the file sizes are interpolated. When expanding, we are simply
852 * writing strings of 0's out. When truncating, we truncate the upper
853 * inode and update the lower_ia according to the page index
854 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
855 * the caller must use lower_ia in a call to notify_change() to perform
856 * the truncation of the lower inode.
858 * Returns zero on success; non-zero otherwise
860 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
861 struct iattr *lower_ia)
864 struct inode *inode = dentry->d_inode;
865 struct ecryptfs_crypt_stat *crypt_stat;
866 loff_t i_size = i_size_read(inode);
867 loff_t lower_size_before_truncate;
868 loff_t lower_size_after_truncate;
870 if (unlikely((ia->ia_size == i_size))) {
871 lower_ia->ia_valid &= ~ATTR_SIZE;
874 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
875 /* Switch on growing or shrinking file */
876 if (ia->ia_size > i_size) {
877 char zero[] = { 0x00 };
879 lower_ia->ia_valid &= ~ATTR_SIZE;
880 /* Write a single 0 at the last position of the file;
881 * this triggers code that will fill in 0's throughout
882 * the intermediate portion of the previous end of the
883 * file and the new and of the file */
884 rc = ecryptfs_write(inode, zero,
885 (ia->ia_size - 1), 1);
886 } else { /* ia->ia_size < i_size_read(inode) */
887 /* We're chopping off all the pages down to the page
888 * in which ia->ia_size is located. Fill in the end of
889 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
890 * PAGE_CACHE_SIZE with zeros. */
891 size_t num_zeros = (PAGE_CACHE_SIZE
892 - (ia->ia_size & ~PAGE_CACHE_MASK));
896 * XXX(truncate) this should really happen at the begginning
897 * of ->setattr. But the code is too messy to that as part
898 * of a larger patch. ecryptfs is also totally missing out
899 * on the inode_change_ok check at the beginning of
900 * ->setattr while would include this.
902 rc = inode_newsize_ok(inode, ia->ia_size);
906 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
907 truncate_setsize(inode, ia->ia_size);
908 lower_ia->ia_size = ia->ia_size;
909 lower_ia->ia_valid |= ATTR_SIZE;
915 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
920 rc = ecryptfs_write(inode, zeros_virt,
921 ia->ia_size, num_zeros);
924 printk(KERN_ERR "Error attempting to zero out "
925 "the remainder of the end page on "
926 "reducing truncate; rc = [%d]\n", rc);
930 truncate_setsize(inode, ia->ia_size);
931 rc = ecryptfs_write_inode_size_to_metadata(inode);
933 printk(KERN_ERR "Problem with "
934 "ecryptfs_write_inode_size_to_metadata; "
938 /* We are reducing the size of the ecryptfs file, and need to
939 * know if we need to reduce the size of the lower file. */
940 lower_size_before_truncate =
941 upper_size_to_lower_size(crypt_stat, i_size);
942 lower_size_after_truncate =
943 upper_size_to_lower_size(crypt_stat, ia->ia_size);
944 if (lower_size_after_truncate < lower_size_before_truncate) {
945 lower_ia->ia_size = lower_size_after_truncate;
946 lower_ia->ia_valid |= ATTR_SIZE;
948 lower_ia->ia_valid &= ~ATTR_SIZE;
956 * @dentry: The ecryptfs layer dentry
957 * @new_length: The length to expand the file to
959 * Simple function that handles the truncation of an eCryptfs inode and
960 * its corresponding lower inode.
962 * Returns zero on success; non-zero otherwise
964 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
966 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
967 struct iattr lower_ia = { .ia_valid = 0 };
970 rc = truncate_upper(dentry, &ia, &lower_ia);
971 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
972 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
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);
982 ecryptfs_permission(struct inode *inode, int mask, unsigned int flags)
984 if (flags & IPERM_FLAG_RCU)
986 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
991 * @dentry: dentry handle to the inode to modify
992 * @ia: Structure with flags of what to change and values
994 * Updates the metadata of an inode. If the update is to the size
995 * i.e. truncation, then ecryptfs_truncate will handle the size modification
996 * of both the ecryptfs inode and the lower inode.
998 * All other metadata changes will be passed right to the lower filesystem,
999 * and we will just update our inode to look like the lower.
1001 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
1004 struct dentry *lower_dentry;
1005 struct iattr lower_ia;
1006 struct inode *inode;
1007 struct inode *lower_inode;
1008 struct ecryptfs_crypt_stat *crypt_stat;
1010 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
1011 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
1012 ecryptfs_init_crypt_stat(crypt_stat);
1013 inode = dentry->d_inode;
1014 lower_inode = ecryptfs_inode_to_lower(inode);
1015 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1016 mutex_lock(&crypt_stat->cs_mutex);
1017 if (S_ISDIR(dentry->d_inode->i_mode))
1018 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
1019 else if (S_ISREG(dentry->d_inode->i_mode)
1020 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
1021 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
1022 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1024 mount_crypt_stat = &ecryptfs_superblock_to_private(
1025 dentry->d_sb)->mount_crypt_stat;
1026 rc = ecryptfs_read_metadata(dentry);
1028 if (!(mount_crypt_stat->flags
1029 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
1031 printk(KERN_WARNING "Either the lower file "
1032 "is not in a valid eCryptfs format, "
1033 "or the key could not be retrieved. "
1034 "Plaintext passthrough mode is not "
1035 "enabled; returning -EIO\n");
1036 mutex_unlock(&crypt_stat->cs_mutex);
1040 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
1043 mutex_unlock(&crypt_stat->cs_mutex);
1044 memcpy(&lower_ia, ia, sizeof(lower_ia));
1045 if (ia->ia_valid & ATTR_FILE)
1046 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
1047 if (ia->ia_valid & ATTR_SIZE) {
1048 rc = truncate_upper(dentry, ia, &lower_ia);
1054 * mode change is for clearing setuid/setgid bits. Allow lower fs
1055 * to interpret this in its own way.
1057 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
1058 lower_ia.ia_valid &= ~ATTR_MODE;
1060 mutex_lock(&lower_dentry->d_inode->i_mutex);
1061 rc = notify_change(lower_dentry, &lower_ia);
1062 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1064 fsstack_copy_attr_all(inode, lower_inode);
1068 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1071 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1074 mount_crypt_stat = &ecryptfs_superblock_to_private(
1075 dentry->d_sb)->mount_crypt_stat;
1076 generic_fillattr(dentry->d_inode, stat);
1077 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1081 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1084 stat->size = targetsiz;
1090 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1093 struct kstat lower_stat;
1096 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1097 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1099 generic_fillattr(dentry->d_inode, stat);
1100 stat->blocks = lower_stat.blocks;
1106 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1107 size_t size, int flags)
1110 struct dentry *lower_dentry;
1112 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1113 if (!lower_dentry->d_inode->i_op->setxattr) {
1118 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1124 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1125 void *value, size_t size)
1129 if (!lower_dentry->d_inode->i_op->getxattr) {
1133 mutex_lock(&lower_dentry->d_inode->i_mutex);
1134 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1136 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1142 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1145 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1150 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1153 struct dentry *lower_dentry;
1155 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1156 if (!lower_dentry->d_inode->i_op->listxattr) {
1160 mutex_lock(&lower_dentry->d_inode->i_mutex);
1161 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1162 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1167 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1170 struct dentry *lower_dentry;
1172 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1173 if (!lower_dentry->d_inode->i_op->removexattr) {
1177 mutex_lock(&lower_dentry->d_inode->i_mutex);
1178 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1179 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1184 int ecryptfs_inode_test(struct inode *inode, void *candidate_lower_inode)
1186 if ((ecryptfs_inode_to_lower(inode)
1187 == (struct inode *)candidate_lower_inode))
1193 int ecryptfs_inode_set(struct inode *inode, void *lower_inode)
1195 ecryptfs_init_inode(inode, (struct inode *)lower_inode);
1199 const struct inode_operations ecryptfs_symlink_iops = {
1200 .readlink = ecryptfs_readlink,
1201 .follow_link = ecryptfs_follow_link,
1202 .put_link = ecryptfs_put_link,
1203 .permission = ecryptfs_permission,
1204 .setattr = ecryptfs_setattr,
1205 .getattr = ecryptfs_getattr_link,
1206 .setxattr = ecryptfs_setxattr,
1207 .getxattr = ecryptfs_getxattr,
1208 .listxattr = ecryptfs_listxattr,
1209 .removexattr = ecryptfs_removexattr
1212 const struct inode_operations ecryptfs_dir_iops = {
1213 .create = ecryptfs_create,
1214 .lookup = ecryptfs_lookup,
1215 .link = ecryptfs_link,
1216 .unlink = ecryptfs_unlink,
1217 .symlink = ecryptfs_symlink,
1218 .mkdir = ecryptfs_mkdir,
1219 .rmdir = ecryptfs_rmdir,
1220 .mknod = ecryptfs_mknod,
1221 .rename = ecryptfs_rename,
1222 .permission = ecryptfs_permission,
1223 .setattr = ecryptfs_setattr,
1224 .setxattr = ecryptfs_setxattr,
1225 .getxattr = ecryptfs_getxattr,
1226 .listxattr = ecryptfs_listxattr,
1227 .removexattr = ecryptfs_removexattr
1230 const struct inode_operations ecryptfs_main_iops = {
1231 .permission = ecryptfs_permission,
1232 .setattr = ecryptfs_setattr,
1233 .getattr = ecryptfs_getattr,
1234 .setxattr = ecryptfs_setxattr,
1235 .getxattr = ecryptfs_getxattr,
1236 .listxattr = ecryptfs_listxattr,
1237 .removexattr = ecryptfs_removexattr