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);
54 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
56 if (ecryptfs_inode_to_lower(inode) == (struct inode *)lower_inode)
61 static int ecryptfs_inode_set(struct inode *inode, void *opaque)
63 struct inode *lower_inode = opaque;
65 ecryptfs_set_inode_lower(inode, lower_inode);
66 fsstack_copy_attr_all(inode, lower_inode);
67 /* i_size will be overwritten for encrypted regular files */
68 fsstack_copy_inode_size(inode, lower_inode);
69 inode->i_ino = lower_inode->i_ino;
71 inode->i_mapping->a_ops = &ecryptfs_aops;
72 inode->i_mapping->backing_dev_info = inode->i_sb->s_bdi;
74 if (S_ISLNK(inode->i_mode))
75 inode->i_op = &ecryptfs_symlink_iops;
76 else if (S_ISDIR(inode->i_mode))
77 inode->i_op = &ecryptfs_dir_iops;
79 inode->i_op = &ecryptfs_main_iops;
81 if (S_ISDIR(inode->i_mode))
82 inode->i_fop = &ecryptfs_dir_fops;
83 else if (special_file(inode->i_mode))
84 init_special_inode(inode, inode->i_mode, inode->i_rdev);
86 inode->i_fop = &ecryptfs_main_fops;
91 static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
92 struct super_block *sb)
96 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
97 return ERR_PTR(-EXDEV);
98 if (!igrab(lower_inode))
99 return ERR_PTR(-ESTALE);
100 inode = iget5_locked(sb, (unsigned long)lower_inode,
101 ecryptfs_inode_test, ecryptfs_inode_set,
105 return ERR_PTR(-EACCES);
107 if (!(inode->i_state & I_NEW))
113 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
114 struct super_block *sb)
116 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
118 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
119 unlock_new_inode(inode);
126 * @lower_dentry: Existing dentry in the lower filesystem
127 * @dentry: ecryptfs' dentry
128 * @sb: ecryptfs's super_block
130 * Interposes upper and lower dentries.
132 * Returns zero on success; non-zero otherwise
134 static int ecryptfs_interpose(struct dentry *lower_dentry,
135 struct dentry *dentry, struct super_block *sb)
137 struct inode *inode = ecryptfs_get_inode(lower_dentry->d_inode, sb);
140 return PTR_ERR(inode);
141 d_instantiate(dentry, inode);
147 * ecryptfs_create_underlying_file
148 * @lower_dir_inode: inode of the parent in the lower fs of the new file
149 * @dentry: New file's dentry
150 * @mode: The mode of the new file
152 * Creates the file in the lower file system.
154 * Returns zero on success; non-zero on error condition
157 ecryptfs_create_underlying_file(struct inode *lower_dir_inode,
158 struct dentry *dentry, int mode)
160 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
161 return vfs_create(lower_dir_inode, lower_dentry, mode, NULL);
166 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
167 * @ecryptfs_dentry: New file's dentry in ecryptfs
168 * @mode: The mode of the new file
169 * @nd: nameidata of ecryptfs' parent's dentry & vfsmount
171 * Creates the underlying file and the eCryptfs inode which will link to
172 * it. It will also update the eCryptfs directory inode to mimic the
173 * stat of the lower directory inode.
175 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
177 static struct inode *
178 ecryptfs_do_create(struct inode *directory_inode,
179 struct dentry *ecryptfs_dentry, int mode)
182 struct dentry *lower_dentry;
183 struct dentry *lower_dir_dentry;
186 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
187 lower_dir_dentry = lock_parent(lower_dentry);
188 if (IS_ERR(lower_dir_dentry)) {
189 ecryptfs_printk(KERN_ERR, "Error locking directory of "
191 inode = ERR_CAST(lower_dir_dentry);
194 rc = ecryptfs_create_underlying_file(lower_dir_dentry->d_inode,
195 ecryptfs_dentry, mode);
197 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
198 "rc = [%d]\n", __func__, rc);
202 inode = __ecryptfs_get_inode(lower_dentry->d_inode,
203 directory_inode->i_sb);
206 fsstack_copy_attr_times(directory_inode, lower_dir_dentry->d_inode);
207 fsstack_copy_inode_size(directory_inode, lower_dir_dentry->d_inode);
209 unlock_dir(lower_dir_dentry);
215 * ecryptfs_initialize_file
217 * Cause the file to be changed from a basic empty file to an ecryptfs
218 * file with a header and first data page.
220 * Returns zero on success
222 static int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
223 struct inode *ecryptfs_inode)
225 struct ecryptfs_crypt_stat *crypt_stat =
226 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
229 if (S_ISDIR(ecryptfs_inode->i_mode)) {
230 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
231 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
234 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
235 rc = ecryptfs_new_file_context(ecryptfs_inode);
237 ecryptfs_printk(KERN_ERR, "Error creating new file "
238 "context; rc = [%d]\n", rc);
241 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
243 printk(KERN_ERR "%s: Error attempting to initialize "
244 "the lower file for the dentry with name "
245 "[%s]; rc = [%d]\n", __func__,
246 ecryptfs_dentry->d_name.name, rc);
249 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
251 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
252 ecryptfs_put_lower_file(ecryptfs_inode);
259 * @dir: The inode of the directory in which to create the file.
260 * @dentry: The eCryptfs dentry
261 * @mode: The mode of the new file.
264 * Creates a new file.
266 * Returns zero on success; non-zero on error condition
269 ecryptfs_create(struct inode *directory_inode, struct dentry *ecryptfs_dentry,
270 int mode, struct nameidata *nd)
272 struct inode *ecryptfs_inode;
275 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
277 if (unlikely(IS_ERR(ecryptfs_inode))) {
278 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
279 "lower filesystem\n");
280 rc = PTR_ERR(ecryptfs_inode);
283 /* At this point, a file exists on "disk"; we need to make sure
284 * that this on disk file is prepared to be an ecryptfs file */
285 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
287 drop_nlink(ecryptfs_inode);
288 unlock_new_inode(ecryptfs_inode);
289 iput(ecryptfs_inode);
292 d_instantiate(ecryptfs_dentry, ecryptfs_inode);
293 unlock_new_inode(ecryptfs_inode);
298 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
300 struct ecryptfs_crypt_stat *crypt_stat;
303 rc = ecryptfs_get_lower_file(dentry, inode);
305 printk(KERN_ERR "%s: Error attempting to initialize "
306 "the lower file for the dentry with name "
307 "[%s]; rc = [%d]\n", __func__,
308 dentry->d_name.name, rc);
312 crypt_stat = &ecryptfs_inode_to_private(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);
317 rc = ecryptfs_read_and_validate_header_region(inode);
318 ecryptfs_put_lower_file(inode);
320 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
322 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
325 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
330 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
332 static int ecryptfs_lookup_interpose(struct dentry *dentry,
333 struct dentry *lower_dentry,
334 struct inode *dir_inode)
336 struct inode *inode, *lower_inode = lower_dentry->d_inode;
337 struct ecryptfs_dentry_info *dentry_info;
338 struct vfsmount *lower_mnt;
341 lower_mnt = mntget(ecryptfs_dentry_to_lower_mnt(dentry->d_parent));
342 fsstack_copy_attr_atime(dir_inode, lower_dentry->d_parent->d_inode);
343 BUG_ON(!lower_dentry->d_count);
345 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
346 ecryptfs_set_dentry_private(dentry, dentry_info);
348 printk(KERN_ERR "%s: Out of memory whilst attempting "
349 "to allocate ecryptfs_dentry_info struct\n",
356 ecryptfs_set_dentry_lower(dentry, lower_dentry);
357 ecryptfs_set_dentry_lower_mnt(dentry, lower_mnt);
359 if (!lower_dentry->d_inode) {
360 /* We want to add because we couldn't find in lower */
364 inode = __ecryptfs_get_inode(lower_inode, dir_inode->i_sb);
366 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
367 __func__, PTR_ERR(inode));
368 return PTR_ERR(inode);
370 if (S_ISREG(inode->i_mode)) {
371 rc = ecryptfs_i_size_read(dentry, inode);
373 make_bad_inode(inode);
378 if (inode->i_state & I_NEW)
379 unlock_new_inode(inode);
380 d_add(dentry, inode);
387 * @ecryptfs_dir_inode: The eCryptfs directory inode
388 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
389 * @ecryptfs_nd: nameidata; may be NULL
391 * Find a file on disk. If the file does not exist, then we'll add it to the
392 * dentry cache and continue on to read it from the disk.
394 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
395 struct dentry *ecryptfs_dentry,
396 struct nameidata *ecryptfs_nd)
398 char *encrypted_and_encoded_name = NULL;
399 size_t encrypted_and_encoded_name_size;
400 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
401 struct dentry *lower_dir_dentry, *lower_dentry;
404 if ((ecryptfs_dentry->d_name.len == 1
405 && !strcmp(ecryptfs_dentry->d_name.name, "."))
406 || (ecryptfs_dentry->d_name.len == 2
407 && !strcmp(ecryptfs_dentry->d_name.name, ".."))) {
410 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
411 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
412 lower_dentry = lookup_one_len(ecryptfs_dentry->d_name.name,
414 ecryptfs_dentry->d_name.len);
415 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
416 if (IS_ERR(lower_dentry)) {
417 rc = PTR_ERR(lower_dentry);
418 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
419 "[%d] on lower_dentry = [%s]\n", __func__, rc,
420 encrypted_and_encoded_name);
423 if (lower_dentry->d_inode)
425 mount_crypt_stat = &ecryptfs_superblock_to_private(
426 ecryptfs_dentry->d_sb)->mount_crypt_stat;
427 if (!(mount_crypt_stat
428 && (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES)))
431 rc = ecryptfs_encrypt_and_encode_filename(
432 &encrypted_and_encoded_name, &encrypted_and_encoded_name_size,
433 NULL, mount_crypt_stat, ecryptfs_dentry->d_name.name,
434 ecryptfs_dentry->d_name.len);
436 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
437 "filename; rc = [%d]\n", __func__, rc);
440 mutex_lock(&lower_dir_dentry->d_inode->i_mutex);
441 lower_dentry = lookup_one_len(encrypted_and_encoded_name,
443 encrypted_and_encoded_name_size);
444 mutex_unlock(&lower_dir_dentry->d_inode->i_mutex);
445 if (IS_ERR(lower_dentry)) {
446 rc = PTR_ERR(lower_dentry);
447 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
448 "[%d] on lower_dentry = [%s]\n", __func__, rc,
449 encrypted_and_encoded_name);
453 rc = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry,
457 d_drop(ecryptfs_dentry);
459 kfree(encrypted_and_encoded_name);
463 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
464 struct dentry *new_dentry)
466 struct dentry *lower_old_dentry;
467 struct dentry *lower_new_dentry;
468 struct dentry *lower_dir_dentry;
472 file_size_save = i_size_read(old_dentry->d_inode);
473 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
474 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
475 dget(lower_old_dentry);
476 dget(lower_new_dentry);
477 lower_dir_dentry = lock_parent(lower_new_dentry);
478 rc = vfs_link(lower_old_dentry, lower_dir_dentry->d_inode,
480 if (rc || !lower_new_dentry->d_inode)
482 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
485 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
486 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
487 set_nlink(old_dentry->d_inode,
488 ecryptfs_inode_to_lower(old_dentry->d_inode)->i_nlink);
489 i_size_write(new_dentry->d_inode, file_size_save);
491 unlock_dir(lower_dir_dentry);
492 dput(lower_new_dentry);
493 dput(lower_old_dentry);
497 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
500 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
501 struct inode *lower_dir_inode = ecryptfs_inode_to_lower(dir);
502 struct dentry *lower_dir_dentry;
505 lower_dir_dentry = lock_parent(lower_dentry);
506 rc = vfs_unlink(lower_dir_inode, lower_dentry);
508 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
511 fsstack_copy_attr_times(dir, lower_dir_inode);
512 set_nlink(dentry->d_inode,
513 ecryptfs_inode_to_lower(dentry->d_inode)->i_nlink);
514 dentry->d_inode->i_ctime = dir->i_ctime;
517 unlock_dir(lower_dir_dentry);
522 static int ecryptfs_symlink(struct inode *dir, struct dentry *dentry,
526 struct dentry *lower_dentry;
527 struct dentry *lower_dir_dentry;
528 char *encoded_symname;
529 size_t encoded_symlen;
530 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
532 lower_dentry = ecryptfs_dentry_to_lower(dentry);
534 lower_dir_dentry = lock_parent(lower_dentry);
535 mount_crypt_stat = &ecryptfs_superblock_to_private(
536 dir->i_sb)->mount_crypt_stat;
537 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
540 mount_crypt_stat, symname,
544 rc = vfs_symlink(lower_dir_dentry->d_inode, lower_dentry,
546 kfree(encoded_symname);
547 if (rc || !lower_dentry->d_inode)
549 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
552 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
553 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
555 unlock_dir(lower_dir_dentry);
557 if (!dentry->d_inode)
562 static int ecryptfs_mkdir(struct inode *dir, struct dentry *dentry, int mode)
565 struct dentry *lower_dentry;
566 struct dentry *lower_dir_dentry;
568 lower_dentry = ecryptfs_dentry_to_lower(dentry);
569 lower_dir_dentry = lock_parent(lower_dentry);
570 rc = vfs_mkdir(lower_dir_dentry->d_inode, lower_dentry, mode);
571 if (rc || !lower_dentry->d_inode)
573 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
576 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
577 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
578 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
580 unlock_dir(lower_dir_dentry);
581 if (!dentry->d_inode)
586 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
588 struct dentry *lower_dentry;
589 struct dentry *lower_dir_dentry;
592 lower_dentry = ecryptfs_dentry_to_lower(dentry);
594 lower_dir_dentry = lock_parent(lower_dentry);
596 rc = vfs_rmdir(lower_dir_dentry->d_inode, lower_dentry);
598 if (!rc && dentry->d_inode)
599 clear_nlink(dentry->d_inode);
600 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
601 set_nlink(dir, lower_dir_dentry->d_inode->i_nlink);
602 unlock_dir(lower_dir_dentry);
610 ecryptfs_mknod(struct inode *dir, struct dentry *dentry, int mode, dev_t dev)
613 struct dentry *lower_dentry;
614 struct dentry *lower_dir_dentry;
616 lower_dentry = ecryptfs_dentry_to_lower(dentry);
617 lower_dir_dentry = lock_parent(lower_dentry);
618 rc = vfs_mknod(lower_dir_dentry->d_inode, lower_dentry, mode, dev);
619 if (rc || !lower_dentry->d_inode)
621 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
624 fsstack_copy_attr_times(dir, lower_dir_dentry->d_inode);
625 fsstack_copy_inode_size(dir, lower_dir_dentry->d_inode);
627 unlock_dir(lower_dir_dentry);
628 if (!dentry->d_inode)
634 ecryptfs_rename(struct inode *old_dir, struct dentry *old_dentry,
635 struct inode *new_dir, struct dentry *new_dentry)
638 struct dentry *lower_old_dentry;
639 struct dentry *lower_new_dentry;
640 struct dentry *lower_old_dir_dentry;
641 struct dentry *lower_new_dir_dentry;
642 struct dentry *trap = NULL;
644 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
645 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
646 dget(lower_old_dentry);
647 dget(lower_new_dentry);
648 lower_old_dir_dentry = dget_parent(lower_old_dentry);
649 lower_new_dir_dentry = dget_parent(lower_new_dentry);
650 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
651 /* source should not be ancestor of target */
652 if (trap == lower_old_dentry) {
656 /* target should not be ancestor of source */
657 if (trap == lower_new_dentry) {
661 rc = vfs_rename(lower_old_dir_dentry->d_inode, lower_old_dentry,
662 lower_new_dir_dentry->d_inode, lower_new_dentry);
665 fsstack_copy_attr_all(new_dir, lower_new_dir_dentry->d_inode);
666 if (new_dir != old_dir)
667 fsstack_copy_attr_all(old_dir, lower_old_dir_dentry->d_inode);
669 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
670 dput(lower_new_dir_dentry);
671 dput(lower_old_dir_dentry);
672 dput(lower_new_dentry);
673 dput(lower_old_dentry);
677 static int ecryptfs_readlink_lower(struct dentry *dentry, char **buf,
680 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
682 size_t lower_bufsiz = PATH_MAX;
686 lower_buf = kmalloc(lower_bufsiz, GFP_KERNEL);
693 rc = lower_dentry->d_inode->i_op->readlink(lower_dentry,
694 (char __user *)lower_buf,
700 rc = ecryptfs_decode_and_decrypt_filename(buf, bufsiz, dentry,
701 lower_buf, lower_bufsiz);
708 ecryptfs_readlink(struct dentry *dentry, char __user *buf, int bufsiz)
711 size_t kbufsiz, copied;
714 rc = ecryptfs_readlink_lower(dentry, &kbuf, &kbufsiz);
717 copied = min_t(size_t, bufsiz, kbufsiz);
718 rc = copy_to_user(buf, kbuf, copied) ? -EFAULT : copied;
720 fsstack_copy_attr_atime(dentry->d_inode,
721 ecryptfs_dentry_to_lower(dentry)->d_inode);
726 static void *ecryptfs_follow_link(struct dentry *dentry, struct nameidata *nd)
729 int len = PAGE_SIZE, rc;
732 /* Released in ecryptfs_put_link(); only release here on error */
733 buf = kmalloc(len, GFP_KERNEL);
735 buf = ERR_PTR(-ENOMEM);
740 rc = dentry->d_inode->i_op->readlink(dentry, (char __user *)buf, len);
748 nd_set_link(nd, buf);
753 ecryptfs_put_link(struct dentry *dentry, struct nameidata *nd, void *ptr)
755 char *buf = nd_get_link(nd);
763 * upper_size_to_lower_size
764 * @crypt_stat: Crypt_stat associated with file
765 * @upper_size: Size of the upper file
767 * Calculate the required size of the lower file based on the
768 * specified size of the upper file. This calculation is based on the
769 * number of headers in the underlying file and the extent size.
771 * Returns Calculated size of the lower file.
774 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
779 lower_size = ecryptfs_lower_header_size(crypt_stat);
780 if (upper_size != 0) {
783 num_extents = upper_size >> crypt_stat->extent_shift;
784 if (upper_size & ~crypt_stat->extent_mask)
786 lower_size += (num_extents * crypt_stat->extent_size);
793 * @dentry: The ecryptfs layer dentry
794 * @ia: Address of the ecryptfs inode's attributes
795 * @lower_ia: Address of the lower inode's attributes
797 * Function to handle truncations modifying the size of the file. Note
798 * that the file sizes are interpolated. When expanding, we are simply
799 * writing strings of 0's out. When truncating, we truncate the upper
800 * inode and update the lower_ia according to the page index
801 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
802 * the caller must use lower_ia in a call to notify_change() to perform
803 * the truncation of the lower inode.
805 * Returns zero on success; non-zero otherwise
807 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
808 struct iattr *lower_ia)
811 struct inode *inode = dentry->d_inode;
812 struct ecryptfs_crypt_stat *crypt_stat;
813 loff_t i_size = i_size_read(inode);
814 loff_t lower_size_before_truncate;
815 loff_t lower_size_after_truncate;
817 if (unlikely((ia->ia_size == i_size))) {
818 lower_ia->ia_valid &= ~ATTR_SIZE;
821 rc = ecryptfs_get_lower_file(dentry, inode);
824 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
825 /* Switch on growing or shrinking file */
826 if (ia->ia_size > i_size) {
827 char zero[] = { 0x00 };
829 lower_ia->ia_valid &= ~ATTR_SIZE;
830 /* Write a single 0 at the last position of the file;
831 * this triggers code that will fill in 0's throughout
832 * the intermediate portion of the previous end of the
833 * file and the new and of the file */
834 rc = ecryptfs_write(inode, zero,
835 (ia->ia_size - 1), 1);
836 } else { /* ia->ia_size < i_size_read(inode) */
837 /* We're chopping off all the pages down to the page
838 * in which ia->ia_size is located. Fill in the end of
839 * that page from (ia->ia_size & ~PAGE_CACHE_MASK) to
840 * PAGE_CACHE_SIZE with zeros. */
841 size_t num_zeros = (PAGE_CACHE_SIZE
842 - (ia->ia_size & ~PAGE_CACHE_MASK));
846 * XXX(truncate) this should really happen at the begginning
847 * of ->setattr. But the code is too messy to that as part
848 * of a larger patch. ecryptfs is also totally missing out
849 * on the inode_change_ok check at the beginning of
850 * ->setattr while would include this.
852 rc = inode_newsize_ok(inode, ia->ia_size);
856 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
857 truncate_setsize(inode, ia->ia_size);
858 lower_ia->ia_size = ia->ia_size;
859 lower_ia->ia_valid |= ATTR_SIZE;
865 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
870 rc = ecryptfs_write(inode, zeros_virt,
871 ia->ia_size, num_zeros);
874 printk(KERN_ERR "Error attempting to zero out "
875 "the remainder of the end page on "
876 "reducing truncate; rc = [%d]\n", rc);
880 truncate_setsize(inode, ia->ia_size);
881 rc = ecryptfs_write_inode_size_to_metadata(inode);
883 printk(KERN_ERR "Problem with "
884 "ecryptfs_write_inode_size_to_metadata; "
888 /* We are reducing the size of the ecryptfs file, and need to
889 * know if we need to reduce the size of the lower file. */
890 lower_size_before_truncate =
891 upper_size_to_lower_size(crypt_stat, i_size);
892 lower_size_after_truncate =
893 upper_size_to_lower_size(crypt_stat, ia->ia_size);
894 if (lower_size_after_truncate < lower_size_before_truncate) {
895 lower_ia->ia_size = lower_size_after_truncate;
896 lower_ia->ia_valid |= ATTR_SIZE;
898 lower_ia->ia_valid &= ~ATTR_SIZE;
901 ecryptfs_put_lower_file(inode);
907 * @dentry: The ecryptfs layer dentry
908 * @new_length: The length to expand the file to
910 * Simple function that handles the truncation of an eCryptfs inode and
911 * its corresponding lower inode.
913 * Returns zero on success; non-zero otherwise
915 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
917 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
918 struct iattr lower_ia = { .ia_valid = 0 };
921 rc = truncate_upper(dentry, &ia, &lower_ia);
922 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
923 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
925 mutex_lock(&lower_dentry->d_inode->i_mutex);
926 rc = notify_change(lower_dentry, &lower_ia);
927 mutex_unlock(&lower_dentry->d_inode->i_mutex);
933 ecryptfs_permission(struct inode *inode, int mask)
935 return inode_permission(ecryptfs_inode_to_lower(inode), mask);
940 * @dentry: dentry handle to the inode to modify
941 * @ia: Structure with flags of what to change and values
943 * Updates the metadata of an inode. If the update is to the size
944 * i.e. truncation, then ecryptfs_truncate will handle the size modification
945 * of both the ecryptfs inode and the lower inode.
947 * All other metadata changes will be passed right to the lower filesystem,
948 * and we will just update our inode to look like the lower.
950 static int ecryptfs_setattr(struct dentry *dentry, struct iattr *ia)
953 struct dentry *lower_dentry;
954 struct iattr lower_ia;
956 struct inode *lower_inode;
957 struct ecryptfs_crypt_stat *crypt_stat;
959 crypt_stat = &ecryptfs_inode_to_private(dentry->d_inode)->crypt_stat;
960 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED))
961 ecryptfs_init_crypt_stat(crypt_stat);
962 inode = dentry->d_inode;
963 lower_inode = ecryptfs_inode_to_lower(inode);
964 lower_dentry = ecryptfs_dentry_to_lower(dentry);
965 mutex_lock(&crypt_stat->cs_mutex);
966 if (S_ISDIR(dentry->d_inode->i_mode))
967 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
968 else if (S_ISREG(dentry->d_inode->i_mode)
969 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
970 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
971 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
973 mount_crypt_stat = &ecryptfs_superblock_to_private(
974 dentry->d_sb)->mount_crypt_stat;
975 rc = ecryptfs_get_lower_file(dentry, inode);
977 mutex_unlock(&crypt_stat->cs_mutex);
980 rc = ecryptfs_read_metadata(dentry);
981 ecryptfs_put_lower_file(inode);
983 if (!(mount_crypt_stat->flags
984 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
986 printk(KERN_WARNING "Either the lower file "
987 "is not in a valid eCryptfs format, "
988 "or the key could not be retrieved. "
989 "Plaintext passthrough mode is not "
990 "enabled; returning -EIO\n");
991 mutex_unlock(&crypt_stat->cs_mutex);
995 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
996 | ECRYPTFS_ENCRYPTED);
999 mutex_unlock(&crypt_stat->cs_mutex);
1000 if (S_ISREG(inode->i_mode)) {
1001 rc = filemap_write_and_wait(inode->i_mapping);
1004 fsstack_copy_attr_all(inode, lower_inode);
1006 memcpy(&lower_ia, ia, sizeof(lower_ia));
1007 if (ia->ia_valid & ATTR_FILE)
1008 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
1009 if (ia->ia_valid & ATTR_SIZE) {
1010 rc = truncate_upper(dentry, ia, &lower_ia);
1016 * mode change is for clearing setuid/setgid bits. Allow lower fs
1017 * to interpret this in its own way.
1019 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
1020 lower_ia.ia_valid &= ~ATTR_MODE;
1022 mutex_lock(&lower_dentry->d_inode->i_mutex);
1023 rc = notify_change(lower_dentry, &lower_ia);
1024 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1026 fsstack_copy_attr_all(inode, lower_inode);
1030 int ecryptfs_getattr_link(struct vfsmount *mnt, struct dentry *dentry,
1033 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
1036 mount_crypt_stat = &ecryptfs_superblock_to_private(
1037 dentry->d_sb)->mount_crypt_stat;
1038 generic_fillattr(dentry->d_inode, stat);
1039 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
1043 rc = ecryptfs_readlink_lower(dentry, &target, &targetsiz);
1046 stat->size = targetsiz;
1052 int ecryptfs_getattr(struct vfsmount *mnt, struct dentry *dentry,
1055 struct kstat lower_stat;
1058 rc = vfs_getattr(ecryptfs_dentry_to_lower_mnt(dentry),
1059 ecryptfs_dentry_to_lower(dentry), &lower_stat);
1061 fsstack_copy_attr_all(dentry->d_inode,
1062 ecryptfs_inode_to_lower(dentry->d_inode));
1063 generic_fillattr(dentry->d_inode, stat);
1064 stat->blocks = lower_stat.blocks;
1070 ecryptfs_setxattr(struct dentry *dentry, const char *name, const void *value,
1071 size_t size, int flags)
1074 struct dentry *lower_dentry;
1076 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1077 if (!lower_dentry->d_inode->i_op->setxattr) {
1082 rc = vfs_setxattr(lower_dentry, name, value, size, flags);
1088 ecryptfs_getxattr_lower(struct dentry *lower_dentry, const char *name,
1089 void *value, size_t size)
1093 if (!lower_dentry->d_inode->i_op->getxattr) {
1097 mutex_lock(&lower_dentry->d_inode->i_mutex);
1098 rc = lower_dentry->d_inode->i_op->getxattr(lower_dentry, name, value,
1100 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1106 ecryptfs_getxattr(struct dentry *dentry, const char *name, void *value,
1109 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry), name,
1114 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1117 struct dentry *lower_dentry;
1119 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1120 if (!lower_dentry->d_inode->i_op->listxattr) {
1124 mutex_lock(&lower_dentry->d_inode->i_mutex);
1125 rc = lower_dentry->d_inode->i_op->listxattr(lower_dentry, list, size);
1126 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1131 static int ecryptfs_removexattr(struct dentry *dentry, const char *name)
1134 struct dentry *lower_dentry;
1136 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1137 if (!lower_dentry->d_inode->i_op->removexattr) {
1141 mutex_lock(&lower_dentry->d_inode->i_mutex);
1142 rc = lower_dentry->d_inode->i_op->removexattr(lower_dentry, name);
1143 mutex_unlock(&lower_dentry->d_inode->i_mutex);
1148 const struct inode_operations ecryptfs_symlink_iops = {
1149 .readlink = ecryptfs_readlink,
1150 .follow_link = ecryptfs_follow_link,
1151 .put_link = ecryptfs_put_link,
1152 .permission = ecryptfs_permission,
1153 .setattr = ecryptfs_setattr,
1154 .getattr = ecryptfs_getattr_link,
1155 .setxattr = ecryptfs_setxattr,
1156 .getxattr = ecryptfs_getxattr,
1157 .listxattr = ecryptfs_listxattr,
1158 .removexattr = ecryptfs_removexattr
1161 const struct inode_operations ecryptfs_dir_iops = {
1162 .create = ecryptfs_create,
1163 .lookup = ecryptfs_lookup,
1164 .link = ecryptfs_link,
1165 .unlink = ecryptfs_unlink,
1166 .symlink = ecryptfs_symlink,
1167 .mkdir = ecryptfs_mkdir,
1168 .rmdir = ecryptfs_rmdir,
1169 .mknod = ecryptfs_mknod,
1170 .rename = ecryptfs_rename,
1171 .permission = ecryptfs_permission,
1172 .setattr = ecryptfs_setattr,
1173 .setxattr = ecryptfs_setxattr,
1174 .getxattr = ecryptfs_getxattr,
1175 .listxattr = ecryptfs_listxattr,
1176 .removexattr = ecryptfs_removexattr
1179 const struct inode_operations ecryptfs_main_iops = {
1180 .permission = ecryptfs_permission,
1181 .setattr = ecryptfs_setattr,
1182 .getattr = ecryptfs_getattr,
1183 .setxattr = ecryptfs_setxattr,
1184 .getxattr = ecryptfs_getxattr,
1185 .listxattr = ecryptfs_listxattr,
1186 .removexattr = ecryptfs_removexattr