1 // SPDX-License-Identifier: GPL-2.0-or-later
3 * eCryptfs: Linux filesystem encryption layer
5 * Copyright (C) 1997-2004 Erez Zadok
6 * Copyright (C) 2001-2004 Stony Brook University
7 * Copyright (C) 2004-2007 International Business Machines Corp.
8 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
9 * Michael C. Thompsion <mcthomps@us.ibm.com>
12 #include <linux/file.h>
13 #include <linux/vmalloc.h>
14 #include <linux/pagemap.h>
15 #include <linux/dcache.h>
16 #include <linux/namei.h>
17 #include <linux/mount.h>
18 #include <linux/fs_stack.h>
19 #include <linux/slab.h>
20 #include <linux/xattr.h>
21 #include <linux/fileattr.h>
22 #include <asm/unaligned.h>
23 #include "ecryptfs_kernel.h"
25 static int lock_parent(struct dentry *dentry,
26 struct dentry **lower_dentry,
27 struct inode **lower_dir)
29 struct dentry *lower_dir_dentry;
31 lower_dir_dentry = ecryptfs_dentry_to_lower(dentry->d_parent);
32 *lower_dir = d_inode(lower_dir_dentry);
33 *lower_dentry = ecryptfs_dentry_to_lower(dentry);
35 inode_lock_nested(*lower_dir, I_MUTEX_PARENT);
36 return (*lower_dentry)->d_parent == lower_dir_dentry ? 0 : -EINVAL;
39 static int ecryptfs_inode_test(struct inode *inode, void *lower_inode)
41 return ecryptfs_inode_to_lower(inode) == lower_inode;
44 static int ecryptfs_inode_set(struct inode *inode, void *opaque)
46 struct inode *lower_inode = opaque;
48 ecryptfs_set_inode_lower(inode, lower_inode);
49 fsstack_copy_attr_all(inode, lower_inode);
50 /* i_size will be overwritten for encrypted regular files */
51 fsstack_copy_inode_size(inode, lower_inode);
52 inode->i_ino = lower_inode->i_ino;
53 inode->i_mapping->a_ops = &ecryptfs_aops;
55 if (S_ISLNK(inode->i_mode))
56 inode->i_op = &ecryptfs_symlink_iops;
57 else if (S_ISDIR(inode->i_mode))
58 inode->i_op = &ecryptfs_dir_iops;
60 inode->i_op = &ecryptfs_main_iops;
62 if (S_ISDIR(inode->i_mode))
63 inode->i_fop = &ecryptfs_dir_fops;
64 else if (special_file(inode->i_mode))
65 init_special_inode(inode, inode->i_mode, inode->i_rdev);
67 inode->i_fop = &ecryptfs_main_fops;
72 static struct inode *__ecryptfs_get_inode(struct inode *lower_inode,
73 struct super_block *sb)
77 if (lower_inode->i_sb != ecryptfs_superblock_to_lower(sb))
78 return ERR_PTR(-EXDEV);
79 if (!igrab(lower_inode))
80 return ERR_PTR(-ESTALE);
81 inode = iget5_locked(sb, (unsigned long)lower_inode,
82 ecryptfs_inode_test, ecryptfs_inode_set,
86 return ERR_PTR(-EACCES);
88 if (!(inode->i_state & I_NEW))
94 struct inode *ecryptfs_get_inode(struct inode *lower_inode,
95 struct super_block *sb)
97 struct inode *inode = __ecryptfs_get_inode(lower_inode, sb);
99 if (!IS_ERR(inode) && (inode->i_state & I_NEW))
100 unlock_new_inode(inode);
107 * @lower_dentry: Existing dentry in the lower filesystem
108 * @dentry: ecryptfs' dentry
109 * @sb: ecryptfs's super_block
111 * Interposes upper and lower dentries.
113 * Returns zero on success; non-zero otherwise
115 static int ecryptfs_interpose(struct dentry *lower_dentry,
116 struct dentry *dentry, struct super_block *sb)
118 struct inode *inode = ecryptfs_get_inode(d_inode(lower_dentry), sb);
121 return PTR_ERR(inode);
122 d_instantiate(dentry, inode);
127 static int ecryptfs_do_unlink(struct inode *dir, struct dentry *dentry,
130 struct dentry *lower_dentry;
131 struct inode *lower_dir;
134 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
135 dget(lower_dentry); // don't even try to make the lower negative
137 if (d_unhashed(lower_dentry))
140 rc = vfs_unlink(&init_user_ns, lower_dir, lower_dentry,
144 printk(KERN_ERR "Error in vfs_unlink; rc = [%d]\n", rc);
147 fsstack_copy_attr_times(dir, lower_dir);
148 set_nlink(inode, ecryptfs_inode_to_lower(inode)->i_nlink);
149 inode->i_ctime = dir->i_ctime;
152 inode_unlock(lower_dir);
160 * @directory_inode: inode of the new file's dentry's parent in ecryptfs
161 * @ecryptfs_dentry: New file's dentry in ecryptfs
162 * @mode: The mode of the new file
164 * Creates the underlying file and the eCryptfs inode which will link to
165 * it. It will also update the eCryptfs directory inode to mimic the
166 * stat of the lower directory inode.
168 * Returns the new eCryptfs inode on success; an ERR_PTR on error condition
170 static struct inode *
171 ecryptfs_do_create(struct inode *directory_inode,
172 struct dentry *ecryptfs_dentry, umode_t mode)
175 struct dentry *lower_dentry;
176 struct inode *lower_dir;
179 rc = lock_parent(ecryptfs_dentry, &lower_dentry, &lower_dir);
181 rc = vfs_create(&init_user_ns, lower_dir,
182 lower_dentry, mode, true);
184 printk(KERN_ERR "%s: Failure to create dentry in lower fs; "
185 "rc = [%d]\n", __func__, rc);
189 inode = __ecryptfs_get_inode(d_inode(lower_dentry),
190 directory_inode->i_sb);
192 vfs_unlink(&init_user_ns, lower_dir, lower_dentry, NULL);
195 fsstack_copy_attr_times(directory_inode, lower_dir);
196 fsstack_copy_inode_size(directory_inode, lower_dir);
198 inode_unlock(lower_dir);
203 * ecryptfs_initialize_file
205 * Cause the file to be changed from a basic empty file to an ecryptfs
206 * file with a header and first data page.
208 * Returns zero on success
210 int ecryptfs_initialize_file(struct dentry *ecryptfs_dentry,
211 struct inode *ecryptfs_inode)
213 struct ecryptfs_crypt_stat *crypt_stat =
214 &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat;
217 if (S_ISDIR(ecryptfs_inode->i_mode)) {
218 ecryptfs_printk(KERN_DEBUG, "This is a directory\n");
219 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
222 ecryptfs_printk(KERN_DEBUG, "Initializing crypto context\n");
223 rc = ecryptfs_new_file_context(ecryptfs_inode);
225 ecryptfs_printk(KERN_ERR, "Error creating new file "
226 "context; rc = [%d]\n", rc);
229 rc = ecryptfs_get_lower_file(ecryptfs_dentry, ecryptfs_inode);
231 printk(KERN_ERR "%s: Error attempting to initialize "
232 "the lower file for the dentry with name "
233 "[%pd]; rc = [%d]\n", __func__,
234 ecryptfs_dentry, rc);
237 rc = ecryptfs_write_metadata(ecryptfs_dentry, ecryptfs_inode);
239 printk(KERN_ERR "Error writing headers; rc = [%d]\n", rc);
240 ecryptfs_put_lower_file(ecryptfs_inode);
247 * @dir: The inode of the directory in which to create the file.
248 * @dentry: The eCryptfs dentry
249 * @mode: The mode of the new file.
251 * Creates a new file.
253 * Returns zero on success; non-zero on error condition
256 ecryptfs_create(struct user_namespace *mnt_userns,
257 struct inode *directory_inode, struct dentry *ecryptfs_dentry,
258 umode_t mode, bool excl)
260 struct inode *ecryptfs_inode;
263 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
265 if (IS_ERR(ecryptfs_inode)) {
266 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
267 "lower filesystem\n");
268 rc = PTR_ERR(ecryptfs_inode);
271 /* At this point, a file exists on "disk"; we need to make sure
272 * that this on disk file is prepared to be an ecryptfs file */
273 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
275 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
277 iget_failed(ecryptfs_inode);
280 d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
285 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
287 struct ecryptfs_crypt_stat *crypt_stat;
290 rc = ecryptfs_get_lower_file(dentry, inode);
292 printk(KERN_ERR "%s: Error attempting to initialize "
293 "the lower file for the dentry with name "
294 "[%pd]; rc = [%d]\n", __func__,
299 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
300 /* TODO: lock for crypt_stat comparison */
301 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
302 ecryptfs_set_default_sizes(crypt_stat);
304 rc = ecryptfs_read_and_validate_header_region(inode);
305 ecryptfs_put_lower_file(inode);
307 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
309 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
312 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
317 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
319 static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
320 struct dentry *lower_dentry)
322 struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
323 struct inode *inode, *lower_inode;
324 struct ecryptfs_dentry_info *dentry_info;
327 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
330 return ERR_PTR(-ENOMEM);
333 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
334 d_inode(path->dentry));
335 BUG_ON(!d_count(lower_dentry));
337 ecryptfs_set_dentry_private(dentry, dentry_info);
338 dentry_info->lower_path.mnt = mntget(path->mnt);
339 dentry_info->lower_path.dentry = lower_dentry;
342 * negative dentry can go positive under us here - its parent is not
343 * locked. That's OK and that could happen just as we return from
344 * ecryptfs_lookup() anyway. Just need to be careful and fetch
345 * ->d_inode only once - it's not stable here.
347 lower_inode = READ_ONCE(lower_dentry->d_inode);
350 /* We want to add because we couldn't find in lower */
354 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
356 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
357 __func__, PTR_ERR(inode));
358 return ERR_CAST(inode);
360 if (S_ISREG(inode->i_mode)) {
361 rc = ecryptfs_i_size_read(dentry, inode);
363 make_bad_inode(inode);
368 if (inode->i_state & I_NEW)
369 unlock_new_inode(inode);
370 return d_splice_alias(inode, dentry);
375 * @ecryptfs_dir_inode: The eCryptfs directory inode
376 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
377 * @flags: lookup flags
379 * Find a file on disk. If the file does not exist, then we'll add it to the
380 * dentry cache and continue on to read it from the disk.
382 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
383 struct dentry *ecryptfs_dentry,
386 char *encrypted_and_encoded_name = NULL;
387 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
388 struct dentry *lower_dir_dentry, *lower_dentry;
389 const char *name = ecryptfs_dentry->d_name.name;
390 size_t len = ecryptfs_dentry->d_name.len;
394 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
396 mount_crypt_stat = &ecryptfs_superblock_to_private(
397 ecryptfs_dentry->d_sb)->mount_crypt_stat;
398 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
399 rc = ecryptfs_encrypt_and_encode_filename(
400 &encrypted_and_encoded_name, &len,
401 mount_crypt_stat, name, len);
403 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
404 "filename; rc = [%d]\n", __func__, rc);
407 name = encrypted_and_encoded_name;
410 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
411 if (IS_ERR(lower_dentry)) {
412 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
413 "[%ld] on lower_dentry = [%s]\n", __func__,
414 PTR_ERR(lower_dentry),
416 res = ERR_CAST(lower_dentry);
418 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
420 kfree(encrypted_and_encoded_name);
424 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
425 struct dentry *new_dentry)
427 struct dentry *lower_old_dentry;
428 struct dentry *lower_new_dentry;
429 struct inode *lower_dir;
433 file_size_save = i_size_read(d_inode(old_dentry));
434 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
435 rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
437 rc = vfs_link(lower_old_dentry, &init_user_ns, lower_dir,
438 lower_new_dentry, NULL);
439 if (rc || d_really_is_negative(lower_new_dentry))
441 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
444 fsstack_copy_attr_times(dir, lower_dir);
445 fsstack_copy_inode_size(dir, lower_dir);
446 set_nlink(d_inode(old_dentry),
447 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
448 i_size_write(d_inode(new_dentry), file_size_save);
450 inode_unlock(lower_dir);
454 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
456 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
459 static int ecryptfs_symlink(struct user_namespace *mnt_userns,
460 struct inode *dir, struct dentry *dentry,
464 struct dentry *lower_dentry;
465 struct inode *lower_dir;
466 char *encoded_symname;
467 size_t encoded_symlen;
468 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
470 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
473 mount_crypt_stat = &ecryptfs_superblock_to_private(
474 dir->i_sb)->mount_crypt_stat;
475 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
477 mount_crypt_stat, symname,
481 rc = vfs_symlink(&init_user_ns, lower_dir, lower_dentry,
483 kfree(encoded_symname);
484 if (rc || d_really_is_negative(lower_dentry))
486 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
489 fsstack_copy_attr_times(dir, lower_dir);
490 fsstack_copy_inode_size(dir, lower_dir);
492 inode_unlock(lower_dir);
493 if (d_really_is_negative(dentry))
498 static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
499 struct dentry *dentry, umode_t mode)
502 struct dentry *lower_dentry;
503 struct inode *lower_dir;
505 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
507 rc = vfs_mkdir(&init_user_ns, lower_dir,
509 if (rc || d_really_is_negative(lower_dentry))
511 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
514 fsstack_copy_attr_times(dir, lower_dir);
515 fsstack_copy_inode_size(dir, lower_dir);
516 set_nlink(dir, lower_dir->i_nlink);
518 inode_unlock(lower_dir);
519 if (d_really_is_negative(dentry))
524 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
526 struct dentry *lower_dentry;
527 struct inode *lower_dir;
530 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
531 dget(lower_dentry); // don't even try to make the lower negative
533 if (d_unhashed(lower_dentry))
536 rc = vfs_rmdir(&init_user_ns, lower_dir, lower_dentry);
539 clear_nlink(d_inode(dentry));
540 fsstack_copy_attr_times(dir, lower_dir);
541 set_nlink(dir, lower_dir->i_nlink);
544 inode_unlock(lower_dir);
551 ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
552 struct dentry *dentry, umode_t mode, dev_t dev)
555 struct dentry *lower_dentry;
556 struct inode *lower_dir;
558 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
560 rc = vfs_mknod(&init_user_ns, lower_dir,
561 lower_dentry, mode, dev);
562 if (rc || d_really_is_negative(lower_dentry))
564 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
567 fsstack_copy_attr_times(dir, lower_dir);
568 fsstack_copy_inode_size(dir, lower_dir);
570 inode_unlock(lower_dir);
571 if (d_really_is_negative(dentry))
577 ecryptfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
578 struct dentry *old_dentry, struct inode *new_dir,
579 struct dentry *new_dentry, unsigned int flags)
582 struct dentry *lower_old_dentry;
583 struct dentry *lower_new_dentry;
584 struct dentry *lower_old_dir_dentry;
585 struct dentry *lower_new_dir_dentry;
587 struct inode *target_inode;
588 struct renamedata rd = {};
593 lower_old_dir_dentry = ecryptfs_dentry_to_lower(old_dentry->d_parent);
594 lower_new_dir_dentry = ecryptfs_dentry_to_lower(new_dentry->d_parent);
596 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
597 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
599 target_inode = d_inode(new_dentry);
601 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
602 dget(lower_new_dentry);
604 if (lower_old_dentry->d_parent != lower_old_dir_dentry)
606 if (lower_new_dentry->d_parent != lower_new_dir_dentry)
608 if (d_unhashed(lower_old_dentry) || d_unhashed(lower_new_dentry))
610 /* source should not be ancestor of target */
611 if (trap == lower_old_dentry)
613 /* target should not be ancestor of source */
614 if (trap == lower_new_dentry) {
619 rd.old_mnt_userns = &init_user_ns;
620 rd.old_dir = d_inode(lower_old_dir_dentry);
621 rd.old_dentry = lower_old_dentry;
622 rd.new_mnt_userns = &init_user_ns;
623 rd.new_dir = d_inode(lower_new_dir_dentry);
624 rd.new_dentry = lower_new_dentry;
625 rc = vfs_rename(&rd);
629 fsstack_copy_attr_all(target_inode,
630 ecryptfs_inode_to_lower(target_inode));
631 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
632 if (new_dir != old_dir)
633 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
635 dput(lower_new_dentry);
636 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
640 static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
642 DEFINE_DELAYED_CALL(done);
643 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
648 link = vfs_get_link(lower_dentry, &done);
650 return ERR_CAST(link);
652 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
654 do_delayed_call(&done);
661 static const char *ecryptfs_get_link(struct dentry *dentry,
663 struct delayed_call *done)
669 return ERR_PTR(-ECHILD);
671 buf = ecryptfs_readlink_lower(dentry, &len);
674 fsstack_copy_attr_atime(d_inode(dentry),
675 d_inode(ecryptfs_dentry_to_lower(dentry)));
677 set_delayed_call(done, kfree_link, buf);
682 * upper_size_to_lower_size
683 * @crypt_stat: Crypt_stat associated with file
684 * @upper_size: Size of the upper file
686 * Calculate the required size of the lower file based on the
687 * specified size of the upper file. This calculation is based on the
688 * number of headers in the underlying file and the extent size.
690 * Returns Calculated size of the lower file.
693 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
698 lower_size = ecryptfs_lower_header_size(crypt_stat);
699 if (upper_size != 0) {
702 num_extents = upper_size >> crypt_stat->extent_shift;
703 if (upper_size & ~crypt_stat->extent_mask)
705 lower_size += (num_extents * crypt_stat->extent_size);
712 * @dentry: The ecryptfs layer dentry
713 * @ia: Address of the ecryptfs inode's attributes
714 * @lower_ia: Address of the lower inode's attributes
716 * Function to handle truncations modifying the size of the file. Note
717 * that the file sizes are interpolated. When expanding, we are simply
718 * writing strings of 0's out. When truncating, we truncate the upper
719 * inode and update the lower_ia according to the page index
720 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
721 * the caller must use lower_ia in a call to notify_change() to perform
722 * the truncation of the lower inode.
724 * Returns zero on success; non-zero otherwise
726 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
727 struct iattr *lower_ia)
730 struct inode *inode = d_inode(dentry);
731 struct ecryptfs_crypt_stat *crypt_stat;
732 loff_t i_size = i_size_read(inode);
733 loff_t lower_size_before_truncate;
734 loff_t lower_size_after_truncate;
736 if (unlikely((ia->ia_size == i_size))) {
737 lower_ia->ia_valid &= ~ATTR_SIZE;
740 rc = ecryptfs_get_lower_file(dentry, inode);
743 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
744 /* Switch on growing or shrinking file */
745 if (ia->ia_size > i_size) {
746 char zero[] = { 0x00 };
748 lower_ia->ia_valid &= ~ATTR_SIZE;
749 /* Write a single 0 at the last position of the file;
750 * this triggers code that will fill in 0's throughout
751 * the intermediate portion of the previous end of the
752 * file and the new and of the file */
753 rc = ecryptfs_write(inode, zero,
754 (ia->ia_size - 1), 1);
755 } else { /* ia->ia_size < i_size_read(inode) */
756 /* We're chopping off all the pages down to the page
757 * in which ia->ia_size is located. Fill in the end of
758 * that page from (ia->ia_size & ~PAGE_MASK) to
759 * PAGE_SIZE with zeros. */
760 size_t num_zeros = (PAGE_SIZE
761 - (ia->ia_size & ~PAGE_MASK));
763 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
764 truncate_setsize(inode, ia->ia_size);
765 lower_ia->ia_size = ia->ia_size;
766 lower_ia->ia_valid |= ATTR_SIZE;
772 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
777 rc = ecryptfs_write(inode, zeros_virt,
778 ia->ia_size, num_zeros);
781 printk(KERN_ERR "Error attempting to zero out "
782 "the remainder of the end page on "
783 "reducing truncate; rc = [%d]\n", rc);
787 truncate_setsize(inode, ia->ia_size);
788 rc = ecryptfs_write_inode_size_to_metadata(inode);
790 printk(KERN_ERR "Problem with "
791 "ecryptfs_write_inode_size_to_metadata; "
795 /* We are reducing the size of the ecryptfs file, and need to
796 * know if we need to reduce the size of the lower file. */
797 lower_size_before_truncate =
798 upper_size_to_lower_size(crypt_stat, i_size);
799 lower_size_after_truncate =
800 upper_size_to_lower_size(crypt_stat, ia->ia_size);
801 if (lower_size_after_truncate < lower_size_before_truncate) {
802 lower_ia->ia_size = lower_size_after_truncate;
803 lower_ia->ia_valid |= ATTR_SIZE;
805 lower_ia->ia_valid &= ~ATTR_SIZE;
808 ecryptfs_put_lower_file(inode);
812 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
814 struct ecryptfs_crypt_stat *crypt_stat;
815 loff_t lower_oldsize, lower_newsize;
817 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
818 lower_oldsize = upper_size_to_lower_size(crypt_stat,
820 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
821 if (lower_newsize > lower_oldsize) {
823 * The eCryptfs inode and the new *lower* size are mixed here
824 * because we may not have the lower i_mutex held and/or it may
825 * not be appropriate to call inode_newsize_ok() with inodes
826 * from other filesystems.
828 return inode_newsize_ok(inode, lower_newsize);
836 * @dentry: The ecryptfs layer dentry
837 * @new_length: The length to expand the file to
839 * Simple function that handles the truncation of an eCryptfs inode and
840 * its corresponding lower inode.
842 * Returns zero on success; non-zero otherwise
844 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
846 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
847 struct iattr lower_ia = { .ia_valid = 0 };
850 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
854 rc = truncate_upper(dentry, &ia, &lower_ia);
855 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
856 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
858 inode_lock(d_inode(lower_dentry));
859 rc = notify_change(&init_user_ns, lower_dentry,
861 inode_unlock(d_inode(lower_dentry));
867 ecryptfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
870 return inode_permission(&init_user_ns,
871 ecryptfs_inode_to_lower(inode), mask);
876 * @dentry: dentry handle to the inode to modify
877 * @ia: Structure with flags of what to change and values
879 * Updates the metadata of an inode. If the update is to the size
880 * i.e. truncation, then ecryptfs_truncate will handle the size modification
881 * of both the ecryptfs inode and the lower inode.
883 * All other metadata changes will be passed right to the lower filesystem,
884 * and we will just update our inode to look like the lower.
886 static int ecryptfs_setattr(struct user_namespace *mnt_userns,
887 struct dentry *dentry, struct iattr *ia)
890 struct dentry *lower_dentry;
891 struct iattr lower_ia;
893 struct inode *lower_inode;
894 struct ecryptfs_crypt_stat *crypt_stat;
896 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
897 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
898 rc = ecryptfs_init_crypt_stat(crypt_stat);
902 inode = d_inode(dentry);
903 lower_inode = ecryptfs_inode_to_lower(inode);
904 lower_dentry = ecryptfs_dentry_to_lower(dentry);
905 mutex_lock(&crypt_stat->cs_mutex);
906 if (d_is_dir(dentry))
907 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
908 else if (d_is_reg(dentry)
909 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
910 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
911 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
913 mount_crypt_stat = &ecryptfs_superblock_to_private(
914 dentry->d_sb)->mount_crypt_stat;
915 rc = ecryptfs_get_lower_file(dentry, inode);
917 mutex_unlock(&crypt_stat->cs_mutex);
920 rc = ecryptfs_read_metadata(dentry);
921 ecryptfs_put_lower_file(inode);
923 if (!(mount_crypt_stat->flags
924 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
926 printk(KERN_WARNING "Either the lower file "
927 "is not in a valid eCryptfs format, "
928 "or the key could not be retrieved. "
929 "Plaintext passthrough mode is not "
930 "enabled; returning -EIO\n");
931 mutex_unlock(&crypt_stat->cs_mutex);
935 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
936 | ECRYPTFS_ENCRYPTED);
939 mutex_unlock(&crypt_stat->cs_mutex);
941 rc = setattr_prepare(&init_user_ns, dentry, ia);
944 if (ia->ia_valid & ATTR_SIZE) {
945 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
950 memcpy(&lower_ia, ia, sizeof(lower_ia));
951 if (ia->ia_valid & ATTR_FILE)
952 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
953 if (ia->ia_valid & ATTR_SIZE) {
954 rc = truncate_upper(dentry, ia, &lower_ia);
960 * mode change is for clearing setuid/setgid bits. Allow lower fs
961 * to interpret this in its own way.
963 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
964 lower_ia.ia_valid &= ~ATTR_MODE;
966 inode_lock(d_inode(lower_dentry));
967 rc = notify_change(&init_user_ns, lower_dentry, &lower_ia, NULL);
968 inode_unlock(d_inode(lower_dentry));
970 fsstack_copy_attr_all(inode, lower_inode);
974 static int ecryptfs_getattr_link(struct user_namespace *mnt_userns,
975 const struct path *path, struct kstat *stat,
976 u32 request_mask, unsigned int flags)
978 struct dentry *dentry = path->dentry;
979 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
982 mount_crypt_stat = &ecryptfs_superblock_to_private(
983 dentry->d_sb)->mount_crypt_stat;
984 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
985 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
989 target = ecryptfs_readlink_lower(dentry, &targetsiz);
990 if (!IS_ERR(target)) {
992 stat->size = targetsiz;
994 rc = PTR_ERR(target);
1000 static int ecryptfs_getattr(struct user_namespace *mnt_userns,
1001 const struct path *path, struct kstat *stat,
1002 u32 request_mask, unsigned int flags)
1004 struct dentry *dentry = path->dentry;
1005 struct kstat lower_stat;
1008 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
1009 request_mask, flags);
1011 fsstack_copy_attr_all(d_inode(dentry),
1012 ecryptfs_inode_to_lower(d_inode(dentry)));
1013 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1014 stat->blocks = lower_stat.blocks;
1020 ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1021 const char *name, const void *value,
1022 size_t size, int flags)
1025 struct dentry *lower_dentry;
1026 struct inode *lower_inode;
1028 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1029 lower_inode = d_inode(lower_dentry);
1030 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1034 inode_lock(lower_inode);
1035 rc = __vfs_setxattr_locked(&init_user_ns, lower_dentry, name, value, size, flags, NULL);
1036 inode_unlock(lower_inode);
1038 fsstack_copy_attr_all(inode, lower_inode);
1044 ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1045 const char *name, void *value, size_t size)
1049 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1053 inode_lock(lower_inode);
1054 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1055 inode_unlock(lower_inode);
1061 ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1062 const char *name, void *value, size_t size)
1064 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1065 ecryptfs_inode_to_lower(inode),
1070 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1073 struct dentry *lower_dentry;
1075 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1076 if (!d_inode(lower_dentry)->i_op->listxattr) {
1080 inode_lock(d_inode(lower_dentry));
1081 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1082 inode_unlock(d_inode(lower_dentry));
1087 static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1091 struct dentry *lower_dentry;
1092 struct inode *lower_inode;
1094 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1095 lower_inode = ecryptfs_inode_to_lower(inode);
1096 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1100 inode_lock(lower_inode);
1101 rc = __vfs_removexattr(&init_user_ns, lower_dentry, name);
1102 inode_unlock(lower_inode);
1107 static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
1109 return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
1112 static int ecryptfs_fileattr_set(struct user_namespace *mnt_userns,
1113 struct dentry *dentry, struct fileattr *fa)
1115 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
1118 rc = vfs_fileattr_set(&init_user_ns, lower_dentry, fa);
1119 fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
1124 const struct inode_operations ecryptfs_symlink_iops = {
1125 .get_link = ecryptfs_get_link,
1126 .permission = ecryptfs_permission,
1127 .setattr = ecryptfs_setattr,
1128 .getattr = ecryptfs_getattr_link,
1129 .listxattr = ecryptfs_listxattr,
1132 const struct inode_operations ecryptfs_dir_iops = {
1133 .create = ecryptfs_create,
1134 .lookup = ecryptfs_lookup,
1135 .link = ecryptfs_link,
1136 .unlink = ecryptfs_unlink,
1137 .symlink = ecryptfs_symlink,
1138 .mkdir = ecryptfs_mkdir,
1139 .rmdir = ecryptfs_rmdir,
1140 .mknod = ecryptfs_mknod,
1141 .rename = ecryptfs_rename,
1142 .permission = ecryptfs_permission,
1143 .setattr = ecryptfs_setattr,
1144 .listxattr = ecryptfs_listxattr,
1145 .fileattr_get = ecryptfs_fileattr_get,
1146 .fileattr_set = ecryptfs_fileattr_set,
1149 const struct inode_operations ecryptfs_main_iops = {
1150 .permission = ecryptfs_permission,
1151 .setattr = ecryptfs_setattr,
1152 .getattr = ecryptfs_getattr,
1153 .listxattr = ecryptfs_listxattr,
1154 .fileattr_get = ecryptfs_fileattr_get,
1155 .fileattr_set = ecryptfs_fileattr_set,
1158 static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1159 struct dentry *dentry, struct inode *inode,
1160 const char *name, void *buffer, size_t size)
1162 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1165 static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1166 struct user_namespace *mnt_userns,
1167 struct dentry *dentry, struct inode *inode,
1168 const char *name, const void *value, size_t size,
1172 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1174 BUG_ON(flags != XATTR_REPLACE);
1175 return ecryptfs_removexattr(dentry, inode, name);
1179 static const struct xattr_handler ecryptfs_xattr_handler = {
1180 .prefix = "", /* match anything */
1181 .get = ecryptfs_xattr_get,
1182 .set = ecryptfs_xattr_set,
1185 const struct xattr_handler *ecryptfs_xattr_handlers[] = {
1186 &ecryptfs_xattr_handler,