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.
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 * @mode: The mode of the new file.
249 * Creates a new file.
251 * Returns zero on success; non-zero on error condition
254 ecryptfs_create(struct user_namespace *mnt_userns,
255 struct inode *directory_inode, struct dentry *ecryptfs_dentry,
256 umode_t mode, bool excl)
258 struct inode *ecryptfs_inode;
261 ecryptfs_inode = ecryptfs_do_create(directory_inode, ecryptfs_dentry,
263 if (IS_ERR(ecryptfs_inode)) {
264 ecryptfs_printk(KERN_WARNING, "Failed to create file in"
265 "lower filesystem\n");
266 rc = PTR_ERR(ecryptfs_inode);
269 /* At this point, a file exists on "disk"; we need to make sure
270 * that this on disk file is prepared to be an ecryptfs file */
271 rc = ecryptfs_initialize_file(ecryptfs_dentry, ecryptfs_inode);
273 ecryptfs_do_unlink(directory_inode, ecryptfs_dentry,
275 iget_failed(ecryptfs_inode);
278 d_instantiate_new(ecryptfs_dentry, ecryptfs_inode);
283 static int ecryptfs_i_size_read(struct dentry *dentry, struct inode *inode)
285 struct ecryptfs_crypt_stat *crypt_stat;
288 rc = ecryptfs_get_lower_file(dentry, inode);
290 printk(KERN_ERR "%s: Error attempting to initialize "
291 "the lower file for the dentry with name "
292 "[%pd]; rc = [%d]\n", __func__,
297 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
298 /* TODO: lock for crypt_stat comparison */
299 if (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED))
300 ecryptfs_set_default_sizes(crypt_stat);
302 rc = ecryptfs_read_and_validate_header_region(inode);
303 ecryptfs_put_lower_file(inode);
305 rc = ecryptfs_read_and_validate_xattr_region(dentry, inode);
307 crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR;
310 /* Must return 0 to allow non-eCryptfs files to be looked up, too */
315 * ecryptfs_lookup_interpose - Dentry interposition for a lookup
317 static struct dentry *ecryptfs_lookup_interpose(struct dentry *dentry,
318 struct dentry *lower_dentry)
320 struct path *path = ecryptfs_dentry_to_lower_path(dentry->d_parent);
321 struct inode *inode, *lower_inode;
322 struct ecryptfs_dentry_info *dentry_info;
325 dentry_info = kmem_cache_alloc(ecryptfs_dentry_info_cache, GFP_KERNEL);
328 return ERR_PTR(-ENOMEM);
331 fsstack_copy_attr_atime(d_inode(dentry->d_parent),
332 d_inode(path->dentry));
333 BUG_ON(!d_count(lower_dentry));
335 ecryptfs_set_dentry_private(dentry, dentry_info);
336 dentry_info->lower_path.mnt = mntget(path->mnt);
337 dentry_info->lower_path.dentry = lower_dentry;
340 * negative dentry can go positive under us here - its parent is not
341 * locked. That's OK and that could happen just as we return from
342 * ecryptfs_lookup() anyway. Just need to be careful and fetch
343 * ->d_inode only once - it's not stable here.
345 lower_inode = READ_ONCE(lower_dentry->d_inode);
348 /* We want to add because we couldn't find in lower */
352 inode = __ecryptfs_get_inode(lower_inode, dentry->d_sb);
354 printk(KERN_ERR "%s: Error interposing; rc = [%ld]\n",
355 __func__, PTR_ERR(inode));
356 return ERR_CAST(inode);
358 if (S_ISREG(inode->i_mode)) {
359 rc = ecryptfs_i_size_read(dentry, inode);
361 make_bad_inode(inode);
366 if (inode->i_state & I_NEW)
367 unlock_new_inode(inode);
368 return d_splice_alias(inode, dentry);
373 * @ecryptfs_dir_inode: The eCryptfs directory inode
374 * @ecryptfs_dentry: The eCryptfs dentry that we are looking up
375 * @flags: lookup flags
377 * Find a file on disk. If the file does not exist, then we'll add it to the
378 * dentry cache and continue on to read it from the disk.
380 static struct dentry *ecryptfs_lookup(struct inode *ecryptfs_dir_inode,
381 struct dentry *ecryptfs_dentry,
384 char *encrypted_and_encoded_name = NULL;
385 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
386 struct dentry *lower_dir_dentry, *lower_dentry;
387 const char *name = ecryptfs_dentry->d_name.name;
388 size_t len = ecryptfs_dentry->d_name.len;
392 lower_dir_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry->d_parent);
394 mount_crypt_stat = &ecryptfs_superblock_to_private(
395 ecryptfs_dentry->d_sb)->mount_crypt_stat;
396 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
397 rc = ecryptfs_encrypt_and_encode_filename(
398 &encrypted_and_encoded_name, &len,
399 mount_crypt_stat, name, len);
401 printk(KERN_ERR "%s: Error attempting to encrypt and encode "
402 "filename; rc = [%d]\n", __func__, rc);
405 name = encrypted_and_encoded_name;
408 lower_dentry = lookup_one_len_unlocked(name, lower_dir_dentry, len);
409 if (IS_ERR(lower_dentry)) {
410 ecryptfs_printk(KERN_DEBUG, "%s: lookup_one_len() returned "
411 "[%ld] on lower_dentry = [%s]\n", __func__,
412 PTR_ERR(lower_dentry),
414 res = ERR_CAST(lower_dentry);
416 res = ecryptfs_lookup_interpose(ecryptfs_dentry, lower_dentry);
418 kfree(encrypted_and_encoded_name);
422 static int ecryptfs_link(struct dentry *old_dentry, struct inode *dir,
423 struct dentry *new_dentry)
425 struct dentry *lower_old_dentry;
426 struct dentry *lower_new_dentry;
427 struct inode *lower_dir;
431 file_size_save = i_size_read(d_inode(old_dentry));
432 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
433 rc = lock_parent(new_dentry, &lower_new_dentry, &lower_dir);
435 rc = vfs_link(lower_old_dentry, &init_user_ns, lower_dir,
436 lower_new_dentry, NULL);
437 if (rc || d_really_is_negative(lower_new_dentry))
439 rc = ecryptfs_interpose(lower_new_dentry, new_dentry, dir->i_sb);
442 fsstack_copy_attr_times(dir, lower_dir);
443 fsstack_copy_inode_size(dir, lower_dir);
444 set_nlink(d_inode(old_dentry),
445 ecryptfs_inode_to_lower(d_inode(old_dentry))->i_nlink);
446 i_size_write(d_inode(new_dentry), file_size_save);
448 inode_unlock(lower_dir);
452 static int ecryptfs_unlink(struct inode *dir, struct dentry *dentry)
454 return ecryptfs_do_unlink(dir, dentry, d_inode(dentry));
457 static int ecryptfs_symlink(struct user_namespace *mnt_userns,
458 struct inode *dir, struct dentry *dentry,
462 struct dentry *lower_dentry;
463 struct inode *lower_dir;
464 char *encoded_symname;
465 size_t encoded_symlen;
466 struct ecryptfs_mount_crypt_stat *mount_crypt_stat = NULL;
468 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
471 mount_crypt_stat = &ecryptfs_superblock_to_private(
472 dir->i_sb)->mount_crypt_stat;
473 rc = ecryptfs_encrypt_and_encode_filename(&encoded_symname,
475 mount_crypt_stat, symname,
479 rc = vfs_symlink(&init_user_ns, lower_dir, lower_dentry,
481 kfree(encoded_symname);
482 if (rc || d_really_is_negative(lower_dentry))
484 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
487 fsstack_copy_attr_times(dir, lower_dir);
488 fsstack_copy_inode_size(dir, lower_dir);
490 inode_unlock(lower_dir);
491 if (d_really_is_negative(dentry))
496 static int ecryptfs_mkdir(struct user_namespace *mnt_userns, struct inode *dir,
497 struct dentry *dentry, umode_t mode)
500 struct dentry *lower_dentry;
501 struct inode *lower_dir;
503 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
505 rc = vfs_mkdir(&init_user_ns, lower_dir,
507 if (rc || d_really_is_negative(lower_dentry))
509 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
512 fsstack_copy_attr_times(dir, lower_dir);
513 fsstack_copy_inode_size(dir, lower_dir);
514 set_nlink(dir, lower_dir->i_nlink);
516 inode_unlock(lower_dir);
517 if (d_really_is_negative(dentry))
522 static int ecryptfs_rmdir(struct inode *dir, struct dentry *dentry)
524 struct dentry *lower_dentry;
525 struct inode *lower_dir;
528 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
529 dget(lower_dentry); // don't even try to make the lower negative
531 if (d_unhashed(lower_dentry))
534 rc = vfs_rmdir(&init_user_ns, lower_dir, lower_dentry);
537 clear_nlink(d_inode(dentry));
538 fsstack_copy_attr_times(dir, lower_dir);
539 set_nlink(dir, lower_dir->i_nlink);
542 inode_unlock(lower_dir);
549 ecryptfs_mknod(struct user_namespace *mnt_userns, struct inode *dir,
550 struct dentry *dentry, umode_t mode, dev_t dev)
553 struct dentry *lower_dentry;
554 struct inode *lower_dir;
556 rc = lock_parent(dentry, &lower_dentry, &lower_dir);
558 rc = vfs_mknod(&init_user_ns, lower_dir,
559 lower_dentry, mode, dev);
560 if (rc || d_really_is_negative(lower_dentry))
562 rc = ecryptfs_interpose(lower_dentry, dentry, dir->i_sb);
565 fsstack_copy_attr_times(dir, lower_dir);
566 fsstack_copy_inode_size(dir, lower_dir);
568 inode_unlock(lower_dir);
569 if (d_really_is_negative(dentry))
575 ecryptfs_rename(struct user_namespace *mnt_userns, struct inode *old_dir,
576 struct dentry *old_dentry, struct inode *new_dir,
577 struct dentry *new_dentry, unsigned int flags)
580 struct dentry *lower_old_dentry;
581 struct dentry *lower_new_dentry;
582 struct dentry *lower_old_dir_dentry;
583 struct dentry *lower_new_dir_dentry;
585 struct inode *target_inode;
586 struct renamedata rd = {};
591 lower_old_dir_dentry = ecryptfs_dentry_to_lower(old_dentry->d_parent);
592 lower_new_dir_dentry = ecryptfs_dentry_to_lower(new_dentry->d_parent);
594 lower_old_dentry = ecryptfs_dentry_to_lower(old_dentry);
595 lower_new_dentry = ecryptfs_dentry_to_lower(new_dentry);
597 target_inode = d_inode(new_dentry);
599 trap = lock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
600 dget(lower_new_dentry);
602 if (lower_old_dentry->d_parent != lower_old_dir_dentry)
604 if (lower_new_dentry->d_parent != lower_new_dir_dentry)
606 if (d_unhashed(lower_old_dentry) || d_unhashed(lower_new_dentry))
608 /* source should not be ancestor of target */
609 if (trap == lower_old_dentry)
611 /* target should not be ancestor of source */
612 if (trap == lower_new_dentry) {
617 rd.old_mnt_userns = &init_user_ns;
618 rd.old_dir = d_inode(lower_old_dir_dentry);
619 rd.old_dentry = lower_old_dentry;
620 rd.new_mnt_userns = &init_user_ns;
621 rd.new_dir = d_inode(lower_new_dir_dentry);
622 rd.new_dentry = lower_new_dentry;
623 rc = vfs_rename(&rd);
627 fsstack_copy_attr_all(target_inode,
628 ecryptfs_inode_to_lower(target_inode));
629 fsstack_copy_attr_all(new_dir, d_inode(lower_new_dir_dentry));
630 if (new_dir != old_dir)
631 fsstack_copy_attr_all(old_dir, d_inode(lower_old_dir_dentry));
633 dput(lower_new_dentry);
634 unlock_rename(lower_old_dir_dentry, lower_new_dir_dentry);
638 static char *ecryptfs_readlink_lower(struct dentry *dentry, size_t *bufsiz)
640 DEFINE_DELAYED_CALL(done);
641 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
646 link = vfs_get_link(lower_dentry, &done);
648 return ERR_CAST(link);
650 rc = ecryptfs_decode_and_decrypt_filename(&buf, bufsiz, dentry->d_sb,
652 do_delayed_call(&done);
659 static const char *ecryptfs_get_link(struct dentry *dentry,
661 struct delayed_call *done)
667 return ERR_PTR(-ECHILD);
669 buf = ecryptfs_readlink_lower(dentry, &len);
672 fsstack_copy_attr_atime(d_inode(dentry),
673 d_inode(ecryptfs_dentry_to_lower(dentry)));
675 set_delayed_call(done, kfree_link, buf);
680 * upper_size_to_lower_size
681 * @crypt_stat: Crypt_stat associated with file
682 * @upper_size: Size of the upper file
684 * Calculate the required size of the lower file based on the
685 * specified size of the upper file. This calculation is based on the
686 * number of headers in the underlying file and the extent size.
688 * Returns Calculated size of the lower file.
691 upper_size_to_lower_size(struct ecryptfs_crypt_stat *crypt_stat,
696 lower_size = ecryptfs_lower_header_size(crypt_stat);
697 if (upper_size != 0) {
700 num_extents = upper_size >> crypt_stat->extent_shift;
701 if (upper_size & ~crypt_stat->extent_mask)
703 lower_size += (num_extents * crypt_stat->extent_size);
710 * @dentry: The ecryptfs layer dentry
711 * @ia: Address of the ecryptfs inode's attributes
712 * @lower_ia: Address of the lower inode's attributes
714 * Function to handle truncations modifying the size of the file. Note
715 * that the file sizes are interpolated. When expanding, we are simply
716 * writing strings of 0's out. When truncating, we truncate the upper
717 * inode and update the lower_ia according to the page index
718 * interpolations. If ATTR_SIZE is set in lower_ia->ia_valid upon return,
719 * the caller must use lower_ia in a call to notify_change() to perform
720 * the truncation of the lower inode.
722 * Returns zero on success; non-zero otherwise
724 static int truncate_upper(struct dentry *dentry, struct iattr *ia,
725 struct iattr *lower_ia)
728 struct inode *inode = d_inode(dentry);
729 struct ecryptfs_crypt_stat *crypt_stat;
730 loff_t i_size = i_size_read(inode);
731 loff_t lower_size_before_truncate;
732 loff_t lower_size_after_truncate;
734 if (unlikely((ia->ia_size == i_size))) {
735 lower_ia->ia_valid &= ~ATTR_SIZE;
738 rc = ecryptfs_get_lower_file(dentry, inode);
741 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
742 /* Switch on growing or shrinking file */
743 if (ia->ia_size > i_size) {
744 char zero[] = { 0x00 };
746 lower_ia->ia_valid &= ~ATTR_SIZE;
747 /* Write a single 0 at the last position of the file;
748 * this triggers code that will fill in 0's throughout
749 * the intermediate portion of the previous end of the
750 * file and the new and of the file */
751 rc = ecryptfs_write(inode, zero,
752 (ia->ia_size - 1), 1);
753 } else { /* ia->ia_size < i_size_read(inode) */
754 /* We're chopping off all the pages down to the page
755 * in which ia->ia_size is located. Fill in the end of
756 * that page from (ia->ia_size & ~PAGE_MASK) to
757 * PAGE_SIZE with zeros. */
758 size_t num_zeros = (PAGE_SIZE
759 - (ia->ia_size & ~PAGE_MASK));
761 if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) {
762 truncate_setsize(inode, ia->ia_size);
763 lower_ia->ia_size = ia->ia_size;
764 lower_ia->ia_valid |= ATTR_SIZE;
770 zeros_virt = kzalloc(num_zeros, GFP_KERNEL);
775 rc = ecryptfs_write(inode, zeros_virt,
776 ia->ia_size, num_zeros);
779 printk(KERN_ERR "Error attempting to zero out "
780 "the remainder of the end page on "
781 "reducing truncate; rc = [%d]\n", rc);
785 truncate_setsize(inode, ia->ia_size);
786 rc = ecryptfs_write_inode_size_to_metadata(inode);
788 printk(KERN_ERR "Problem with "
789 "ecryptfs_write_inode_size_to_metadata; "
793 /* We are reducing the size of the ecryptfs file, and need to
794 * know if we need to reduce the size of the lower file. */
795 lower_size_before_truncate =
796 upper_size_to_lower_size(crypt_stat, i_size);
797 lower_size_after_truncate =
798 upper_size_to_lower_size(crypt_stat, ia->ia_size);
799 if (lower_size_after_truncate < lower_size_before_truncate) {
800 lower_ia->ia_size = lower_size_after_truncate;
801 lower_ia->ia_valid |= ATTR_SIZE;
803 lower_ia->ia_valid &= ~ATTR_SIZE;
806 ecryptfs_put_lower_file(inode);
810 static int ecryptfs_inode_newsize_ok(struct inode *inode, loff_t offset)
812 struct ecryptfs_crypt_stat *crypt_stat;
813 loff_t lower_oldsize, lower_newsize;
815 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
816 lower_oldsize = upper_size_to_lower_size(crypt_stat,
818 lower_newsize = upper_size_to_lower_size(crypt_stat, offset);
819 if (lower_newsize > lower_oldsize) {
821 * The eCryptfs inode and the new *lower* size are mixed here
822 * because we may not have the lower i_mutex held and/or it may
823 * not be appropriate to call inode_newsize_ok() with inodes
824 * from other filesystems.
826 return inode_newsize_ok(inode, lower_newsize);
834 * @dentry: The ecryptfs layer dentry
835 * @new_length: The length to expand the file to
837 * Simple function that handles the truncation of an eCryptfs inode and
838 * its corresponding lower inode.
840 * Returns zero on success; non-zero otherwise
842 int ecryptfs_truncate(struct dentry *dentry, loff_t new_length)
844 struct iattr ia = { .ia_valid = ATTR_SIZE, .ia_size = new_length };
845 struct iattr lower_ia = { .ia_valid = 0 };
848 rc = ecryptfs_inode_newsize_ok(d_inode(dentry), new_length);
852 rc = truncate_upper(dentry, &ia, &lower_ia);
853 if (!rc && lower_ia.ia_valid & ATTR_SIZE) {
854 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
856 inode_lock(d_inode(lower_dentry));
857 rc = notify_change(&init_user_ns, lower_dentry,
859 inode_unlock(d_inode(lower_dentry));
865 ecryptfs_permission(struct user_namespace *mnt_userns, struct inode *inode,
868 return inode_permission(&init_user_ns,
869 ecryptfs_inode_to_lower(inode), mask);
874 * @mnt_userns: user namespace of the target mount
875 * @dentry: dentry handle to the inode to modify
876 * @ia: Structure with flags of what to change and values
878 * Updates the metadata of an inode. If the update is to the size
879 * i.e. truncation, then ecryptfs_truncate will handle the size modification
880 * of both the ecryptfs inode and the lower inode.
882 * All other metadata changes will be passed right to the lower filesystem,
883 * and we will just update our inode to look like the lower.
885 static int ecryptfs_setattr(struct user_namespace *mnt_userns,
886 struct dentry *dentry, struct iattr *ia)
889 struct dentry *lower_dentry;
890 struct iattr lower_ia;
892 struct inode *lower_inode;
893 struct ecryptfs_crypt_stat *crypt_stat;
895 crypt_stat = &ecryptfs_inode_to_private(d_inode(dentry))->crypt_stat;
896 if (!(crypt_stat->flags & ECRYPTFS_STRUCT_INITIALIZED)) {
897 rc = ecryptfs_init_crypt_stat(crypt_stat);
901 inode = d_inode(dentry);
902 lower_inode = ecryptfs_inode_to_lower(inode);
903 lower_dentry = ecryptfs_dentry_to_lower(dentry);
904 mutex_lock(&crypt_stat->cs_mutex);
905 if (d_is_dir(dentry))
906 crypt_stat->flags &= ~(ECRYPTFS_ENCRYPTED);
907 else if (d_is_reg(dentry)
908 && (!(crypt_stat->flags & ECRYPTFS_POLICY_APPLIED)
909 || !(crypt_stat->flags & ECRYPTFS_KEY_VALID))) {
910 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
912 mount_crypt_stat = &ecryptfs_superblock_to_private(
913 dentry->d_sb)->mount_crypt_stat;
914 rc = ecryptfs_get_lower_file(dentry, inode);
916 mutex_unlock(&crypt_stat->cs_mutex);
919 rc = ecryptfs_read_metadata(dentry);
920 ecryptfs_put_lower_file(inode);
922 if (!(mount_crypt_stat->flags
923 & ECRYPTFS_PLAINTEXT_PASSTHROUGH_ENABLED)) {
925 printk(KERN_WARNING "Either the lower file "
926 "is not in a valid eCryptfs format, "
927 "or the key could not be retrieved. "
928 "Plaintext passthrough mode is not "
929 "enabled; returning -EIO\n");
930 mutex_unlock(&crypt_stat->cs_mutex);
934 crypt_stat->flags &= ~(ECRYPTFS_I_SIZE_INITIALIZED
935 | ECRYPTFS_ENCRYPTED);
938 mutex_unlock(&crypt_stat->cs_mutex);
940 rc = setattr_prepare(&init_user_ns, dentry, ia);
943 if (ia->ia_valid & ATTR_SIZE) {
944 rc = ecryptfs_inode_newsize_ok(inode, ia->ia_size);
949 memcpy(&lower_ia, ia, sizeof(lower_ia));
950 if (ia->ia_valid & ATTR_FILE)
951 lower_ia.ia_file = ecryptfs_file_to_lower(ia->ia_file);
952 if (ia->ia_valid & ATTR_SIZE) {
953 rc = truncate_upper(dentry, ia, &lower_ia);
959 * mode change is for clearing setuid/setgid bits. Allow lower fs
960 * to interpret this in its own way.
962 if (lower_ia.ia_valid & (ATTR_KILL_SUID | ATTR_KILL_SGID))
963 lower_ia.ia_valid &= ~ATTR_MODE;
965 inode_lock(d_inode(lower_dentry));
966 rc = notify_change(&init_user_ns, lower_dentry, &lower_ia, NULL);
967 inode_unlock(d_inode(lower_dentry));
969 fsstack_copy_attr_all(inode, lower_inode);
973 static int ecryptfs_getattr_link(struct user_namespace *mnt_userns,
974 const struct path *path, struct kstat *stat,
975 u32 request_mask, unsigned int flags)
977 struct dentry *dentry = path->dentry;
978 struct ecryptfs_mount_crypt_stat *mount_crypt_stat;
981 mount_crypt_stat = &ecryptfs_superblock_to_private(
982 dentry->d_sb)->mount_crypt_stat;
983 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
984 if (mount_crypt_stat->flags & ECRYPTFS_GLOBAL_ENCRYPT_FILENAMES) {
988 target = ecryptfs_readlink_lower(dentry, &targetsiz);
989 if (!IS_ERR(target)) {
991 stat->size = targetsiz;
993 rc = PTR_ERR(target);
999 static int ecryptfs_getattr(struct user_namespace *mnt_userns,
1000 const struct path *path, struct kstat *stat,
1001 u32 request_mask, unsigned int flags)
1003 struct dentry *dentry = path->dentry;
1004 struct kstat lower_stat;
1007 rc = vfs_getattr(ecryptfs_dentry_to_lower_path(dentry), &lower_stat,
1008 request_mask, flags);
1010 fsstack_copy_attr_all(d_inode(dentry),
1011 ecryptfs_inode_to_lower(d_inode(dentry)));
1012 generic_fillattr(&init_user_ns, d_inode(dentry), stat);
1013 stat->blocks = lower_stat.blocks;
1019 ecryptfs_setxattr(struct dentry *dentry, struct inode *inode,
1020 const char *name, const void *value,
1021 size_t size, int flags)
1024 struct dentry *lower_dentry;
1025 struct inode *lower_inode;
1027 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1028 lower_inode = d_inode(lower_dentry);
1029 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1033 inode_lock(lower_inode);
1034 rc = __vfs_setxattr_locked(&init_user_ns, lower_dentry, name, value, size, flags, NULL);
1035 inode_unlock(lower_inode);
1037 fsstack_copy_attr_all(inode, lower_inode);
1043 ecryptfs_getxattr_lower(struct dentry *lower_dentry, struct inode *lower_inode,
1044 const char *name, void *value, size_t size)
1048 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1052 inode_lock(lower_inode);
1053 rc = __vfs_getxattr(lower_dentry, lower_inode, name, value, size);
1054 inode_unlock(lower_inode);
1060 ecryptfs_getxattr(struct dentry *dentry, struct inode *inode,
1061 const char *name, void *value, size_t size)
1063 return ecryptfs_getxattr_lower(ecryptfs_dentry_to_lower(dentry),
1064 ecryptfs_inode_to_lower(inode),
1069 ecryptfs_listxattr(struct dentry *dentry, char *list, size_t size)
1072 struct dentry *lower_dentry;
1074 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1075 if (!d_inode(lower_dentry)->i_op->listxattr) {
1079 inode_lock(d_inode(lower_dentry));
1080 rc = d_inode(lower_dentry)->i_op->listxattr(lower_dentry, list, size);
1081 inode_unlock(d_inode(lower_dentry));
1086 static int ecryptfs_removexattr(struct dentry *dentry, struct inode *inode,
1090 struct dentry *lower_dentry;
1091 struct inode *lower_inode;
1093 lower_dentry = ecryptfs_dentry_to_lower(dentry);
1094 lower_inode = ecryptfs_inode_to_lower(inode);
1095 if (!(lower_inode->i_opflags & IOP_XATTR)) {
1099 inode_lock(lower_inode);
1100 rc = __vfs_removexattr(&init_user_ns, lower_dentry, name);
1101 inode_unlock(lower_inode);
1106 static int ecryptfs_fileattr_get(struct dentry *dentry, struct fileattr *fa)
1108 return vfs_fileattr_get(ecryptfs_dentry_to_lower(dentry), fa);
1111 static int ecryptfs_fileattr_set(struct user_namespace *mnt_userns,
1112 struct dentry *dentry, struct fileattr *fa)
1114 struct dentry *lower_dentry = ecryptfs_dentry_to_lower(dentry);
1117 rc = vfs_fileattr_set(&init_user_ns, lower_dentry, fa);
1118 fsstack_copy_attr_all(d_inode(dentry), d_inode(lower_dentry));
1123 const struct inode_operations ecryptfs_symlink_iops = {
1124 .get_link = ecryptfs_get_link,
1125 .permission = ecryptfs_permission,
1126 .setattr = ecryptfs_setattr,
1127 .getattr = ecryptfs_getattr_link,
1128 .listxattr = ecryptfs_listxattr,
1131 const struct inode_operations ecryptfs_dir_iops = {
1132 .create = ecryptfs_create,
1133 .lookup = ecryptfs_lookup,
1134 .link = ecryptfs_link,
1135 .unlink = ecryptfs_unlink,
1136 .symlink = ecryptfs_symlink,
1137 .mkdir = ecryptfs_mkdir,
1138 .rmdir = ecryptfs_rmdir,
1139 .mknod = ecryptfs_mknod,
1140 .rename = ecryptfs_rename,
1141 .permission = ecryptfs_permission,
1142 .setattr = ecryptfs_setattr,
1143 .listxattr = ecryptfs_listxattr,
1144 .fileattr_get = ecryptfs_fileattr_get,
1145 .fileattr_set = ecryptfs_fileattr_set,
1148 const struct inode_operations ecryptfs_main_iops = {
1149 .permission = ecryptfs_permission,
1150 .setattr = ecryptfs_setattr,
1151 .getattr = ecryptfs_getattr,
1152 .listxattr = ecryptfs_listxattr,
1153 .fileattr_get = ecryptfs_fileattr_get,
1154 .fileattr_set = ecryptfs_fileattr_set,
1157 static int ecryptfs_xattr_get(const struct xattr_handler *handler,
1158 struct dentry *dentry, struct inode *inode,
1159 const char *name, void *buffer, size_t size)
1161 return ecryptfs_getxattr(dentry, inode, name, buffer, size);
1164 static int ecryptfs_xattr_set(const struct xattr_handler *handler,
1165 struct user_namespace *mnt_userns,
1166 struct dentry *dentry, struct inode *inode,
1167 const char *name, const void *value, size_t size,
1171 return ecryptfs_setxattr(dentry, inode, name, value, size, flags);
1173 BUG_ON(flags != XATTR_REPLACE);
1174 return ecryptfs_removexattr(dentry, inode, name);
1178 static const struct xattr_handler ecryptfs_xattr_handler = {
1179 .prefix = "", /* match anything */
1180 .get = ecryptfs_xattr_get,
1181 .set = ecryptfs_xattr_set,
1184 const struct xattr_handler *ecryptfs_xattr_handlers[] = {
1185 &ecryptfs_xattr_handler,