2 * eCryptfs: Linux filesystem encryption layer
3 * This is where eCryptfs coordinates the symmetric encryption and
4 * decryption of the file data as it passes between the lower
5 * encrypted file and the upper decrypted file.
7 * Copyright (C) 1997-2003 Erez Zadok
8 * Copyright (C) 2001-2003 Stony Brook University
9 * Copyright (C) 2004-2007 International Business Machines Corp.
10 * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com>
12 * This program is free software; you can redistribute it and/or
13 * modify it under the terms of the GNU General Public License as
14 * published by the Free Software Foundation; either version 2 of the
15 * License, or (at your option) any later version.
17 * This program is distributed in the hope that it will be useful, but
18 * WITHOUT ANY WARRANTY; without even the implied warranty of
19 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
20 * General Public License for more details.
22 * You should have received a copy of the GNU General Public License
23 * along with this program; if not, write to the Free Software
24 * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
28 #include <linux/pagemap.h>
29 #include <linux/writeback.h>
30 #include <linux/page-flags.h>
31 #include <linux/mount.h>
32 #include <linux/file.h>
33 #include <linux/crypto.h>
34 #include <linux/scatterlist.h>
35 #include "ecryptfs_kernel.h"
37 struct kmem_cache *ecryptfs_lower_page_cache;
42 * Get one page from cache or lower f/s, return error otherwise.
44 * Returns unlocked and up-to-date page (if ok), with increased
47 static struct page *ecryptfs_get1page(struct file *file, int index)
49 struct dentry *dentry;
51 struct address_space *mapping;
53 dentry = file->f_path.dentry;
54 inode = dentry->d_inode;
55 mapping = inode->i_mapping;
56 return read_mapping_page(mapping, index, (void *)file);
61 * @file: The ecryptfs file
62 * @new_length: The new length of the data in the underlying file;
63 * everything between the prior end of the file and the
64 * new end of the file will be filled with zero's.
65 * new_length must be greater than current length
67 * Function for handling lseek-ing past the end of the file.
69 * This function does not support shrinking, only growing a file.
71 * Returns zero on success; non-zero otherwise.
73 int ecryptfs_fill_zeros(struct file *file, loff_t new_length)
76 struct dentry *dentry = file->f_path.dentry;
77 struct inode *inode = dentry->d_inode;
78 pgoff_t old_end_page_index = 0;
79 pgoff_t index = old_end_page_index;
80 int old_end_pos_in_page = -1;
81 pgoff_t new_end_page_index;
82 int new_end_pos_in_page;
83 loff_t cur_length = i_size_read(inode);
85 if (cur_length != 0) {
86 index = old_end_page_index =
87 ((cur_length - 1) >> PAGE_CACHE_SHIFT);
88 old_end_pos_in_page = ((cur_length - 1) & ~PAGE_CACHE_MASK);
90 new_end_page_index = ((new_length - 1) >> PAGE_CACHE_SHIFT);
91 new_end_pos_in_page = ((new_length - 1) & ~PAGE_CACHE_MASK);
92 ecryptfs_printk(KERN_DEBUG, "old_end_page_index = [0x%.16x]; "
93 "old_end_pos_in_page = [%d]; "
94 "new_end_page_index = [0x%.16x]; "
95 "new_end_pos_in_page = [%d]\n",
96 old_end_page_index, old_end_pos_in_page,
97 new_end_page_index, new_end_pos_in_page);
98 if (old_end_page_index == new_end_page_index) {
99 /* Start and end are in the same page; we just need to
100 * set a portion of the existing page to zero's */
101 rc = ecryptfs_write_zeros(file, index,
102 (old_end_pos_in_page + 1),
104 - old_end_pos_in_page));
106 ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros("
109 "old_end_pos_in_page=[d], "
110 "(PAGE_CACHE_SIZE - new_end_pos_in_page"
112 ")=[d]) returned [%d]\n", file, index,
115 (PAGE_CACHE_SIZE - new_end_pos_in_page),
119 /* Fill the remainder of the previous last page with zeros */
120 rc = ecryptfs_write_zeros(file, index, (old_end_pos_in_page + 1),
121 ((PAGE_CACHE_SIZE - 1) - old_end_pos_in_page));
123 ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros(file=[%p], "
124 "index=[0x%.16x], old_end_pos_in_page=[d], "
125 "(PAGE_CACHE_SIZE - old_end_pos_in_page)=[d]) "
126 "returned [%d]\n", file, index,
128 (PAGE_CACHE_SIZE - old_end_pos_in_page), rc);
132 while (index < new_end_page_index) {
133 /* Fill all intermediate pages with zeros */
134 rc = ecryptfs_write_zeros(file, index, 0, PAGE_CACHE_SIZE);
136 ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros("
139 "old_end_pos_in_page=[d], "
140 "(PAGE_CACHE_SIZE - new_end_pos_in_page"
142 ")=[d]) returned [%d]\n", file, index,
145 (PAGE_CACHE_SIZE - new_end_pos_in_page),
151 /* Fill the portion at the beginning of the last new page with
153 rc = ecryptfs_write_zeros(file, index, 0, (new_end_pos_in_page + 1));
155 ecryptfs_printk(KERN_ERR, "ecryptfs_write_zeros(file="
156 "[%p], index=[0x%.16x], 0, "
157 "new_end_pos_in_page=[%d]"
158 "returned [%d]\n", file, index,
159 new_end_pos_in_page, rc);
168 * @page: Page that is locked before this call is made
170 * Returns zero on success; non-zero otherwise
172 static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc)
174 struct ecryptfs_page_crypt_context ctx;
178 ctx.mode = ECRYPTFS_WRITEPAGE_MODE;
180 rc = ecryptfs_encrypt_page(&ctx);
182 ecryptfs_printk(KERN_WARNING, "Error encrypting "
183 "page (upper index [0x%.16x])\n", page->index);
184 ClearPageUptodate(page);
187 SetPageUptodate(page);
194 * Reads the data from the lower file file at index lower_page_index
195 * and copies that data into page.
197 * @param page Page to fill
198 * @param lower_page_index Index of the page in the lower file to get
200 int ecryptfs_do_readpage(struct file *file, struct page *page,
201 pgoff_t lower_page_index)
204 struct dentry *dentry;
205 struct file *lower_file;
206 struct dentry *lower_dentry;
208 struct inode *lower_inode;
210 struct page *lower_page = NULL;
211 char *lower_page_data;
212 const struct address_space_operations *lower_a_ops;
214 dentry = file->f_path.dentry;
215 lower_file = ecryptfs_file_to_lower(file);
216 lower_dentry = ecryptfs_dentry_to_lower(dentry);
217 inode = dentry->d_inode;
218 lower_inode = ecryptfs_inode_to_lower(inode);
219 lower_a_ops = lower_inode->i_mapping->a_ops;
220 lower_page = read_cache_page(lower_inode->i_mapping, lower_page_index,
221 (filler_t *)lower_a_ops->readpage,
223 if (IS_ERR(lower_page)) {
224 rc = PTR_ERR(lower_page);
226 ecryptfs_printk(KERN_ERR, "Error reading from page cache\n");
229 page_data = kmap_atomic(page, KM_USER0);
230 lower_page_data = kmap_atomic(lower_page, KM_USER1);
231 memcpy(page_data, lower_page_data, PAGE_CACHE_SIZE);
232 kunmap_atomic(lower_page_data, KM_USER1);
233 kunmap_atomic(page_data, KM_USER0);
234 flush_dcache_page(page);
237 if (likely(lower_page))
238 page_cache_release(lower_page);
240 SetPageUptodate(page);
242 ClearPageUptodate(page);
247 * Octets 0-7: Unencrypted file size (big-endian)
248 * Octets 8-15: eCryptfs special marker
249 * Octets 16-19: Flags
250 * Octet 16: File format version number (between 0 and 255)
251 * Octets 17-18: Reserved
252 * Octet 19: Bit 1 (lsb): Reserved
255 * Octets 20-23: Header extent size (big-endian)
256 * Octets 24-25: Number of header extents at front of file
258 * Octet 26: Begin RFC 2440 authentication token packet set
260 static void set_header_info(char *page_virt,
261 struct ecryptfs_crypt_stat *crypt_stat)
264 int save_num_header_extents_at_front =
265 crypt_stat->num_header_extents_at_front;
267 crypt_stat->num_header_extents_at_front = 1;
268 ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written);
269 crypt_stat->num_header_extents_at_front =
270 save_num_header_extents_at_front;
275 * @file: This is an ecryptfs file
276 * @page: ecryptfs associated page to stick the read data into
278 * Read in a page, decrypting if necessary.
280 * Returns zero on success; non-zero on error.
282 static int ecryptfs_readpage(struct file *file, struct page *page)
285 struct ecryptfs_crypt_stat *crypt_stat;
287 BUG_ON(!(file && file->f_path.dentry && file->f_path.dentry->d_inode));
288 crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
291 || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)
292 || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) {
293 ecryptfs_printk(KERN_DEBUG,
294 "Passing through unencrypted page\n");
295 rc = ecryptfs_do_readpage(file, page, page->index);
297 ecryptfs_printk(KERN_ERR, "Error reading page; rc = "
301 } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) {
302 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) {
303 int num_pages_in_header_region =
304 (crypt_stat->header_extent_size
307 if (page->index < num_pages_in_header_region) {
310 page_virt = kmap_atomic(page, KM_USER0);
311 memset(page_virt, 0, PAGE_CACHE_SIZE);
312 if (page->index == 0) {
313 rc = ecryptfs_read_xattr_region(
314 page_virt, file->f_path.dentry);
315 set_header_info(page_virt, crypt_stat);
317 kunmap_atomic(page_virt, KM_USER0);
318 flush_dcache_page(page);
320 printk(KERN_ERR "Error reading xattr "
325 rc = ecryptfs_do_readpage(
328 - num_pages_in_header_region));
330 printk(KERN_ERR "Error reading page; "
336 rc = ecryptfs_do_readpage(file, page, page->index);
338 printk(KERN_ERR "Error reading page; rc = "
344 rc = ecryptfs_decrypt_page(file, page);
346 ecryptfs_printk(KERN_ERR, "Error decrypting page; "
351 SetPageUptodate(page);
354 ClearPageUptodate(page);
355 ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
362 * Called with lower inode mutex held.
364 static int fill_zeros_to_end_of_page(struct page *page, unsigned int to)
366 struct inode *inode = page->mapping->host;
367 int end_byte_in_page;
369 if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index)
371 end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE;
372 if (to > end_byte_in_page)
373 end_byte_in_page = to;
374 zero_user_page(page, end_byte_in_page,
375 PAGE_CACHE_SIZE - end_byte_in_page, KM_USER0);
381 * eCryptfs does not currently support holes. When writing after a
382 * seek past the end of the file, eCryptfs fills in 0's through to the
383 * current location. The code to fill in the 0's to all the
384 * intermediate pages calls ecryptfs_prepare_write_no_truncate().
387 ecryptfs_prepare_write_no_truncate(struct file *file, struct page *page,
388 unsigned from, unsigned to)
392 if (from == 0 && to == PAGE_CACHE_SIZE)
393 goto out; /* If we are writing a full page, it will be
395 if (!PageUptodate(page))
396 rc = ecryptfs_do_readpage(file, page, page->index);
401 static int ecryptfs_prepare_write(struct file *file, struct page *page,
402 unsigned from, unsigned to)
406 if (from == 0 && to == PAGE_CACHE_SIZE)
407 goto out; /* If we are writing a full page, it will be
409 if (!PageUptodate(page))
410 rc = ecryptfs_do_readpage(file, page, page->index);
411 if (page->index != 0) {
412 loff_t end_of_prev_pg_pos =
413 (((loff_t)page->index << PAGE_CACHE_SHIFT) - 1);
415 if (end_of_prev_pg_pos > i_size_read(page->mapping->host)) {
416 rc = ecryptfs_truncate(file->f_path.dentry,
419 printk(KERN_ERR "Error on attempt to "
420 "truncate to (higher) offset [%lld];"
421 " rc = [%d]\n", end_of_prev_pg_pos, rc);
430 int ecryptfs_writepage_and_release_lower_page(struct page *lower_page,
431 struct inode *lower_inode,
432 struct writeback_control *wbc)
436 rc = lower_inode->i_mapping->a_ops->writepage(lower_page, wbc);
438 ecryptfs_printk(KERN_ERR, "Error calling lower writepage(); "
442 lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
443 page_cache_release(lower_page);
449 void ecryptfs_release_lower_page(struct page *lower_page, int page_locked)
452 unlock_page(lower_page);
453 page_cache_release(lower_page);
457 * ecryptfs_write_inode_size_to_header
459 * Writes the lower file size to the first 8 bytes of the header.
461 * Returns zero on success; non-zero on error.
463 static int ecryptfs_write_inode_size_to_header(struct file *lower_file,
464 struct inode *lower_inode,
468 struct page *header_page;
470 const struct address_space_operations *lower_a_ops;
474 header_page = grab_cache_page(lower_inode->i_mapping, 0);
476 ecryptfs_printk(KERN_ERR, "grab_cache_page for "
477 "lower_page_index 0 failed\n");
481 lower_a_ops = lower_inode->i_mapping->a_ops;
482 rc = lower_a_ops->prepare_write(lower_file, header_page, 0, 8);
484 if (rc == AOP_TRUNCATED_PAGE) {
485 ecryptfs_release_lower_page(header_page, 0);
488 ecryptfs_release_lower_page(header_page, 1);
491 file_size = (u64)i_size_read(inode);
492 ecryptfs_printk(KERN_DEBUG, "Writing size: [0x%.16x]\n", file_size);
493 file_size = cpu_to_be64(file_size);
494 header_virt = kmap_atomic(header_page, KM_USER0);
495 memcpy(header_virt, &file_size, sizeof(u64));
496 kunmap_atomic(header_virt, KM_USER0);
497 flush_dcache_page(header_page);
498 rc = lower_a_ops->commit_write(lower_file, header_page, 0, 8);
500 ecryptfs_printk(KERN_ERR, "Error commiting header page "
502 if (rc == AOP_TRUNCATED_PAGE) {
503 ecryptfs_release_lower_page(header_page, 0);
506 ecryptfs_release_lower_page(header_page, 1);
507 lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
508 mark_inode_dirty_sync(inode);
513 static int ecryptfs_write_inode_size_to_xattr(struct inode *lower_inode,
515 struct dentry *ecryptfs_dentry,
516 int lower_i_mutex_held)
520 struct dentry *lower_dentry;
524 xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL);
526 printk(KERN_ERR "Out of memory whilst attempting to write "
527 "inode size to xattr\n");
531 lower_dentry = ecryptfs_dentry_to_lower(ecryptfs_dentry);
532 if (!lower_dentry->d_inode->i_op->getxattr ||
533 !lower_dentry->d_inode->i_op->setxattr) {
535 "No support for setting xattr in lower filesystem\n");
537 kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
540 if (!lower_i_mutex_held)
541 mutex_lock(&lower_dentry->d_inode->i_mutex);
542 size = lower_dentry->d_inode->i_op->getxattr(lower_dentry,
546 if (!lower_i_mutex_held)
547 mutex_unlock(&lower_dentry->d_inode->i_mutex);
550 file_size = (u64)i_size_read(inode);
551 file_size = cpu_to_be64(file_size);
552 memcpy(xattr_virt, &file_size, sizeof(u64));
553 if (!lower_i_mutex_held)
554 mutex_lock(&lower_dentry->d_inode->i_mutex);
555 rc = lower_dentry->d_inode->i_op->setxattr(lower_dentry,
557 xattr_virt, size, 0);
558 if (!lower_i_mutex_held)
559 mutex_unlock(&lower_dentry->d_inode->i_mutex);
561 printk(KERN_ERR "Error whilst attempting to write inode size "
562 "to lower file xattr; rc = [%d]\n", rc);
563 kmem_cache_free(ecryptfs_xattr_cache, xattr_virt);
569 ecryptfs_write_inode_size_to_metadata(struct file *lower_file,
570 struct inode *lower_inode,
572 struct dentry *ecryptfs_dentry,
573 int lower_i_mutex_held)
575 struct ecryptfs_crypt_stat *crypt_stat;
577 crypt_stat = &ecryptfs_inode_to_private(inode)->crypt_stat;
578 if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR)
579 return ecryptfs_write_inode_size_to_xattr(lower_inode, inode,
583 return ecryptfs_write_inode_size_to_header(lower_file,
588 int ecryptfs_get_lower_page(struct page **lower_page, struct inode *lower_inode,
589 struct file *lower_file,
590 unsigned long lower_page_index, int byte_offset,
596 *lower_page = grab_cache_page(lower_inode->i_mapping, lower_page_index);
597 if (!(*lower_page)) {
599 ecryptfs_printk(KERN_ERR, "Error attempting to grab "
600 "lower page with index [0x%.16x]\n",
604 rc = lower_inode->i_mapping->a_ops->prepare_write(lower_file,
609 if (rc == AOP_TRUNCATED_PAGE) {
610 ecryptfs_release_lower_page(*lower_page, 0);
613 ecryptfs_printk(KERN_ERR, "prepare_write for "
614 "lower_page_index = [0x%.16x] failed; rc = "
615 "[%d]\n", lower_page_index, rc);
616 ecryptfs_release_lower_page(*lower_page, 1);
617 (*lower_page) = NULL;
625 * ecryptfs_commit_lower_page
627 * Returns zero on success; non-zero on error
630 ecryptfs_commit_lower_page(struct page *lower_page, struct inode *lower_inode,
631 struct file *lower_file, int byte_offset,
637 rc = lower_inode->i_mapping->a_ops->commit_write(
638 lower_file, lower_page, byte_offset, region_size);
639 if (rc == AOP_TRUNCATED_PAGE)
642 ecryptfs_printk(KERN_ERR,
643 "Error committing write; rc = [%d]\n", rc);
646 ecryptfs_release_lower_page(lower_page, page_locked);
651 * ecryptfs_copy_page_to_lower
653 * Used for plaintext pass-through; no page index interpolation
656 int ecryptfs_copy_page_to_lower(struct page *page, struct inode *lower_inode,
657 struct file *lower_file)
660 struct page *lower_page;
662 rc = ecryptfs_get_lower_page(&lower_page, lower_inode, lower_file,
663 page->index, 0, PAGE_CACHE_SIZE);
665 ecryptfs_printk(KERN_ERR, "Error attempting to get page "
666 "at index [0x%.16x]\n", page->index);
670 memcpy((char *)page_address(lower_page), page_address(page),
672 rc = ecryptfs_commit_lower_page(lower_page, lower_inode, lower_file,
675 ecryptfs_printk(KERN_ERR, "Error attempting to commit page "
676 "at index [0x%.16x]\n", page->index);
681 struct kmem_cache *ecryptfs_xattr_cache;
684 * ecryptfs_commit_write
685 * @file: The eCryptfs file object
686 * @page: The eCryptfs page
687 * @from: Ignored (we rotate the page IV on each write)
690 * This is where we encrypt the data and pass the encrypted data to
691 * the lower filesystem. In OpenPGP-compatible mode, we operate on
692 * entire underlying packets.
694 static int ecryptfs_commit_write(struct file *file, struct page *page,
695 unsigned from, unsigned to)
697 struct ecryptfs_page_crypt_context ctx;
700 struct inode *lower_inode;
701 struct file *lower_file;
702 struct ecryptfs_crypt_stat *crypt_stat;
705 inode = page->mapping->host;
706 lower_inode = ecryptfs_inode_to_lower(inode);
707 lower_file = ecryptfs_file_to_lower(file);
708 mutex_lock(&lower_inode->i_mutex);
709 crypt_stat = &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)
711 if (crypt_stat->flags & ECRYPTFS_NEW_FILE) {
712 ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in "
713 "crypt_stat at memory location [%p]\n", crypt_stat);
714 crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE);
716 ecryptfs_printk(KERN_DEBUG, "Not a new file\n");
717 ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page"
718 "(page w/ index = [0x%.16x], to = [%d])\n", page->index,
720 rc = fill_zeros_to_end_of_page(page, to);
722 ecryptfs_printk(KERN_WARNING, "Error attempting to fill "
723 "zeros in page with index = [0x%.16x]\n",
728 ctx.mode = ECRYPTFS_PREPARE_COMMIT_MODE;
729 ctx.param.lower_file = lower_file;
730 rc = ecryptfs_encrypt_page(&ctx);
732 ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper "
733 "index [0x%.16x])\n", page->index);
736 inode->i_blocks = lower_inode->i_blocks;
737 pos = (page->index << PAGE_CACHE_SHIFT) + to;
738 if (pos > i_size_read(inode)) {
739 i_size_write(inode, pos);
740 ecryptfs_printk(KERN_DEBUG, "Expanded file size to "
741 "[0x%.16x]\n", i_size_read(inode));
743 rc = ecryptfs_write_inode_size_to_metadata(lower_file, lower_inode,
744 inode, file->f_dentry,
745 ECRYPTFS_LOWER_I_MUTEX_HELD);
747 printk(KERN_ERR "Error writing inode size to metadata; "
749 lower_inode->i_mtime = lower_inode->i_ctime = CURRENT_TIME;
750 mark_inode_dirty_sync(inode);
753 ClearPageUptodate(page);
755 SetPageUptodate(page);
756 mutex_unlock(&lower_inode->i_mutex);
761 * ecryptfs_write_zeros
762 * @file: The ecryptfs file
763 * @index: The index in which we are writing
764 * @start: The position after the last block of data
765 * @num_zeros: The number of zeros to write
767 * Write a specified number of zero's to a page.
769 * (start + num_zeros) must be less than or equal to PAGE_CACHE_SIZE
772 ecryptfs_write_zeros(struct file *file, pgoff_t index, int start, int num_zeros)
775 struct page *tmp_page;
777 tmp_page = ecryptfs_get1page(file, index);
778 if (IS_ERR(tmp_page)) {
779 ecryptfs_printk(KERN_ERR, "Error getting page at index "
780 "[0x%.16x]\n", index);
781 rc = PTR_ERR(tmp_page);
784 if ((rc = ecryptfs_prepare_write_no_truncate(file, tmp_page, start,
785 (start + num_zeros)))) {
786 ecryptfs_printk(KERN_ERR, "Error preparing to write zero's "
787 "to page at index [0x%.16x]\n",
789 page_cache_release(tmp_page);
792 zero_user_page(tmp_page, start, num_zeros, KM_USER0);
793 rc = ecryptfs_commit_write(file, tmp_page, start, start + num_zeros);
795 ecryptfs_printk(KERN_ERR, "Error attempting to write zero's "
796 "to remainder of page at index [0x%.16x]\n",
798 page_cache_release(tmp_page);
802 page_cache_release(tmp_page);
807 static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block)
811 struct inode *lower_inode;
813 inode = (struct inode *)mapping->host;
814 lower_inode = ecryptfs_inode_to_lower(inode);
815 if (lower_inode->i_mapping->a_ops->bmap)
816 rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping,
821 static void ecryptfs_sync_page(struct page *page)
824 struct inode *lower_inode;
825 struct page *lower_page;
827 inode = page->mapping->host;
828 lower_inode = ecryptfs_inode_to_lower(inode);
829 /* NOTE: Recently swapped with grab_cache_page(), since
830 * sync_page() just makes sure that pending I/O gets done. */
831 lower_page = find_lock_page(lower_inode->i_mapping, page->index);
833 ecryptfs_printk(KERN_DEBUG, "find_lock_page failed\n");
836 lower_page->mapping->a_ops->sync_page(lower_page);
837 ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n",
839 unlock_page(lower_page);
840 page_cache_release(lower_page);
843 struct address_space_operations ecryptfs_aops = {
844 .writepage = ecryptfs_writepage,
845 .readpage = ecryptfs_readpage,
846 .prepare_write = ecryptfs_prepare_write,
847 .commit_write = ecryptfs_commit_write,
848 .bmap = ecryptfs_bmap,
849 .sync_page = ecryptfs_sync_page,