1da0102a1SMichael Halcrow /** 2da0102a1SMichael Halcrow * eCryptfs: Linux filesystem encryption layer 3da0102a1SMichael Halcrow * 4da0102a1SMichael Halcrow * Copyright (C) 2007 International Business Machines Corp. 5da0102a1SMichael Halcrow * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> 6da0102a1SMichael Halcrow * 7da0102a1SMichael Halcrow * This program is free software; you can redistribute it and/or 8da0102a1SMichael Halcrow * modify it under the terms of the GNU General Public License as 9da0102a1SMichael Halcrow * published by the Free Software Foundation; either version 2 of the 10da0102a1SMichael Halcrow * License, or (at your option) any later version. 11da0102a1SMichael Halcrow * 12da0102a1SMichael Halcrow * This program is distributed in the hope that it will be useful, but 13da0102a1SMichael Halcrow * WITHOUT ANY WARRANTY; without even the implied warranty of 14da0102a1SMichael Halcrow * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 15da0102a1SMichael Halcrow * General Public License for more details. 16da0102a1SMichael Halcrow * 17da0102a1SMichael Halcrow * You should have received a copy of the GNU General Public License 18da0102a1SMichael Halcrow * along with this program; if not, write to the Free Software 19da0102a1SMichael Halcrow * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 20da0102a1SMichael Halcrow * 02111-1307, USA. 21da0102a1SMichael Halcrow */ 22da0102a1SMichael Halcrow 23da0102a1SMichael Halcrow #include <linux/fs.h> 24da0102a1SMichael Halcrow #include <linux/pagemap.h> 25da0102a1SMichael Halcrow #include "ecryptfs_kernel.h" 26da0102a1SMichael Halcrow 27da0102a1SMichael Halcrow /** 28da0102a1SMichael Halcrow * ecryptfs_write_lower 29da0102a1SMichael Halcrow * @ecryptfs_inode: The eCryptfs inode 30da0102a1SMichael Halcrow * @data: Data to write 31da0102a1SMichael Halcrow * @offset: Byte offset in the lower file to which to write the data 32da0102a1SMichael Halcrow * @size: Number of bytes from @data to write at @offset in the lower 33da0102a1SMichael Halcrow * file 34da0102a1SMichael Halcrow * 35da0102a1SMichael Halcrow * Write data to the lower file. 36da0102a1SMichael Halcrow * 37da0102a1SMichael Halcrow * Returns zero on success; non-zero on error 38da0102a1SMichael Halcrow */ 39da0102a1SMichael Halcrow int ecryptfs_write_lower(struct inode *ecryptfs_inode, char *data, 40da0102a1SMichael Halcrow loff_t offset, size_t size) 41da0102a1SMichael Halcrow { 42da0102a1SMichael Halcrow struct ecryptfs_inode_info *inode_info; 43da0102a1SMichael Halcrow ssize_t octets_written; 44da0102a1SMichael Halcrow mm_segment_t fs_save; 45da0102a1SMichael Halcrow int rc = 0; 46da0102a1SMichael Halcrow 47da0102a1SMichael Halcrow inode_info = ecryptfs_inode_to_private(ecryptfs_inode); 48da0102a1SMichael Halcrow mutex_lock(&inode_info->lower_file_mutex); 49da0102a1SMichael Halcrow BUG_ON(!inode_info->lower_file); 50da0102a1SMichael Halcrow inode_info->lower_file->f_pos = offset; 51da0102a1SMichael Halcrow fs_save = get_fs(); 52da0102a1SMichael Halcrow set_fs(get_ds()); 53da0102a1SMichael Halcrow octets_written = vfs_write(inode_info->lower_file, data, size, 54da0102a1SMichael Halcrow &inode_info->lower_file->f_pos); 55da0102a1SMichael Halcrow set_fs(fs_save); 56da0102a1SMichael Halcrow if (octets_written < 0) { 57da0102a1SMichael Halcrow printk(KERN_ERR "%s: octets_written = [%td]; " 5818d1dbf1SHarvey Harrison "expected [%td]\n", __func__, octets_written, size); 59da0102a1SMichael Halcrow rc = -EINVAL; 60da0102a1SMichael Halcrow } 61da0102a1SMichael Halcrow mutex_unlock(&inode_info->lower_file_mutex); 62da0102a1SMichael Halcrow mark_inode_dirty_sync(ecryptfs_inode); 63da0102a1SMichael Halcrow return rc; 64da0102a1SMichael Halcrow } 65da0102a1SMichael Halcrow 66da0102a1SMichael Halcrow /** 67da0102a1SMichael Halcrow * ecryptfs_write_lower_page_segment 68da0102a1SMichael Halcrow * @ecryptfs_inode: The eCryptfs inode 69da0102a1SMichael Halcrow * @page_for_lower: The page containing the data to be written to the 70da0102a1SMichael Halcrow * lower file 71da0102a1SMichael Halcrow * @offset_in_page: The offset in the @page_for_lower from which to 72da0102a1SMichael Halcrow * start writing the data 73da0102a1SMichael Halcrow * @size: The amount of data from @page_for_lower to write to the 74da0102a1SMichael Halcrow * lower file 75da0102a1SMichael Halcrow * 76da0102a1SMichael Halcrow * Determines the byte offset in the file for the given page and 77da0102a1SMichael Halcrow * offset within the page, maps the page, and makes the call to write 78da0102a1SMichael Halcrow * the contents of @page_for_lower to the lower inode. 79da0102a1SMichael Halcrow * 80da0102a1SMichael Halcrow * Returns zero on success; non-zero otherwise 81da0102a1SMichael Halcrow */ 82da0102a1SMichael Halcrow int ecryptfs_write_lower_page_segment(struct inode *ecryptfs_inode, 83da0102a1SMichael Halcrow struct page *page_for_lower, 84da0102a1SMichael Halcrow size_t offset_in_page, size_t size) 85da0102a1SMichael Halcrow { 86da0102a1SMichael Halcrow char *virt; 87da0102a1SMichael Halcrow loff_t offset; 88da0102a1SMichael Halcrow int rc; 89da0102a1SMichael Halcrow 908a146a2bSMichael Halcrow offset = ((((loff_t)page_for_lower->index) << PAGE_CACHE_SHIFT) 91d6a13c17SMichael Halcrow + offset_in_page); 92da0102a1SMichael Halcrow virt = kmap(page_for_lower); 93da0102a1SMichael Halcrow rc = ecryptfs_write_lower(ecryptfs_inode, virt, offset, size); 94da0102a1SMichael Halcrow kunmap(page_for_lower); 95da0102a1SMichael Halcrow return rc; 96da0102a1SMichael Halcrow } 97da0102a1SMichael Halcrow 98da0102a1SMichael Halcrow /** 99da0102a1SMichael Halcrow * ecryptfs_write 100da0102a1SMichael Halcrow * @ecryptfs_file: The eCryptfs file into which to write 101da0102a1SMichael Halcrow * @data: Virtual address where data to write is located 102da0102a1SMichael Halcrow * @offset: Offset in the eCryptfs file at which to begin writing the 103da0102a1SMichael Halcrow * data from @data 104da0102a1SMichael Halcrow * @size: The number of bytes to write from @data 105da0102a1SMichael Halcrow * 106da0102a1SMichael Halcrow * Write an arbitrary amount of data to an arbitrary location in the 107da0102a1SMichael Halcrow * eCryptfs inode page cache. This is done on a page-by-page, and then 108da0102a1SMichael Halcrow * by an extent-by-extent, basis; individual extents are encrypted and 109da0102a1SMichael Halcrow * written to the lower page cache (via VFS writes). This function 110da0102a1SMichael Halcrow * takes care of all the address translation to locations in the lower 111da0102a1SMichael Halcrow * filesystem; it also handles truncate events, writing out zeros 112da0102a1SMichael Halcrow * where necessary. 113da0102a1SMichael Halcrow * 114da0102a1SMichael Halcrow * Returns zero on success; non-zero otherwise 115da0102a1SMichael Halcrow */ 116da0102a1SMichael Halcrow int ecryptfs_write(struct file *ecryptfs_file, char *data, loff_t offset, 117da0102a1SMichael Halcrow size_t size) 118da0102a1SMichael Halcrow { 119da0102a1SMichael Halcrow struct page *ecryptfs_page; 120*13a791b4STyler Hicks struct ecryptfs_crypt_stat *crypt_stat; 121*13a791b4STyler Hicks struct inode *ecryptfs_inode = ecryptfs_file->f_dentry->d_inode; 122da0102a1SMichael Halcrow char *ecryptfs_page_virt; 123*13a791b4STyler Hicks loff_t ecryptfs_file_size = i_size_read(ecryptfs_inode); 124da0102a1SMichael Halcrow loff_t data_offset = 0; 125da0102a1SMichael Halcrow loff_t pos; 126da0102a1SMichael Halcrow int rc = 0; 127da0102a1SMichael Halcrow 128*13a791b4STyler Hicks crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; 1297a3f595cSEric Sandeen /* 1307a3f595cSEric Sandeen * if we are writing beyond current size, then start pos 1317a3f595cSEric Sandeen * at the current size - we'll fill in zeros from there. 1327a3f595cSEric Sandeen */ 133da0102a1SMichael Halcrow if (offset > ecryptfs_file_size) 134da0102a1SMichael Halcrow pos = ecryptfs_file_size; 135da0102a1SMichael Halcrow else 136da0102a1SMichael Halcrow pos = offset; 137da0102a1SMichael Halcrow while (pos < (offset + size)) { 138da0102a1SMichael Halcrow pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT); 139da0102a1SMichael Halcrow size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK); 140da0102a1SMichael Halcrow size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page); 141da0102a1SMichael Halcrow size_t total_remaining_bytes = ((offset + size) - pos); 142da0102a1SMichael Halcrow 143da0102a1SMichael Halcrow if (num_bytes > total_remaining_bytes) 144da0102a1SMichael Halcrow num_bytes = total_remaining_bytes; 145da0102a1SMichael Halcrow if (pos < offset) { 1467a3f595cSEric Sandeen /* remaining zeros to write, up to destination offset */ 147da0102a1SMichael Halcrow size_t total_remaining_zeros = (offset - pos); 148da0102a1SMichael Halcrow 149da0102a1SMichael Halcrow if (num_bytes > total_remaining_zeros) 150da0102a1SMichael Halcrow num_bytes = total_remaining_zeros; 151da0102a1SMichael Halcrow } 15216a72c45SMichael Halcrow ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file, 153da0102a1SMichael Halcrow ecryptfs_page_idx); 154da0102a1SMichael Halcrow if (IS_ERR(ecryptfs_page)) { 155da0102a1SMichael Halcrow rc = PTR_ERR(ecryptfs_page); 156da0102a1SMichael Halcrow printk(KERN_ERR "%s: Error getting page at " 157da0102a1SMichael Halcrow "index [%ld] from eCryptfs inode " 15818d1dbf1SHarvey Harrison "mapping; rc = [%d]\n", __func__, 159da0102a1SMichael Halcrow ecryptfs_page_idx, rc); 160da0102a1SMichael Halcrow goto out; 161da0102a1SMichael Halcrow } 162da0102a1SMichael Halcrow ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0); 1637a3f595cSEric Sandeen 1647a3f595cSEric Sandeen /* 1657a3f595cSEric Sandeen * pos: where we're now writing, offset: where the request was 1667a3f595cSEric Sandeen * If current pos is before request, we are filling zeros 1677a3f595cSEric Sandeen * If we are at or beyond request, we are writing the *data* 1687a3f595cSEric Sandeen * If we're in a fresh page beyond eof, zero it in either case 1697a3f595cSEric Sandeen */ 1707a3f595cSEric Sandeen if (pos < offset || !start_offset_in_page) { 1717a3f595cSEric Sandeen /* We are extending past the previous end of the file. 1727a3f595cSEric Sandeen * Fill in zero values to the end of the page */ 1737a3f595cSEric Sandeen memset(((char *)ecryptfs_page_virt 1747a3f595cSEric Sandeen + start_offset_in_page), 0, 1757a3f595cSEric Sandeen PAGE_CACHE_SIZE - start_offset_in_page); 1767a3f595cSEric Sandeen } 1777a3f595cSEric Sandeen 1787a3f595cSEric Sandeen /* pos >= offset, we are now writing the data request */ 179da0102a1SMichael Halcrow if (pos >= offset) { 180da0102a1SMichael Halcrow memcpy(((char *)ecryptfs_page_virt 181da0102a1SMichael Halcrow + start_offset_in_page), 182da0102a1SMichael Halcrow (data + data_offset), num_bytes); 183da0102a1SMichael Halcrow data_offset += num_bytes; 184da0102a1SMichael Halcrow } 185da0102a1SMichael Halcrow kunmap_atomic(ecryptfs_page_virt, KM_USER0); 186da0102a1SMichael Halcrow flush_dcache_page(ecryptfs_page); 18716a72c45SMichael Halcrow SetPageUptodate(ecryptfs_page); 18816a72c45SMichael Halcrow unlock_page(ecryptfs_page); 189*13a791b4STyler Hicks if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) 1900216f7f7SMichael Halcrow rc = ecryptfs_encrypt_page(ecryptfs_page); 191*13a791b4STyler Hicks else 192*13a791b4STyler Hicks rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, 193*13a791b4STyler Hicks ecryptfs_page, 194*13a791b4STyler Hicks start_offset_in_page, 195*13a791b4STyler Hicks data_offset); 19616a72c45SMichael Halcrow page_cache_release(ecryptfs_page); 197da0102a1SMichael Halcrow if (rc) { 198da0102a1SMichael Halcrow printk(KERN_ERR "%s: Error encrypting " 19918d1dbf1SHarvey Harrison "page; rc = [%d]\n", __func__, rc); 200da0102a1SMichael Halcrow goto out; 201da0102a1SMichael Halcrow } 202da0102a1SMichael Halcrow pos += num_bytes; 203da0102a1SMichael Halcrow } 204da0102a1SMichael Halcrow if ((offset + size) > ecryptfs_file_size) { 205*13a791b4STyler Hicks i_size_write(ecryptfs_inode, (offset + size)); 206*13a791b4STyler Hicks if (crypt_stat->flags & ECRYPTFS_ENCRYPTED) { 2070216f7f7SMichael Halcrow rc = ecryptfs_write_inode_size_to_metadata( 208*13a791b4STyler Hicks ecryptfs_inode); 209da0102a1SMichael Halcrow if (rc) { 210da0102a1SMichael Halcrow printk(KERN_ERR "Problem with " 211da0102a1SMichael Halcrow "ecryptfs_write_inode_size_to_metadata; " 212da0102a1SMichael Halcrow "rc = [%d]\n", rc); 213da0102a1SMichael Halcrow goto out; 214da0102a1SMichael Halcrow } 215da0102a1SMichael Halcrow } 216*13a791b4STyler Hicks } 217da0102a1SMichael Halcrow out: 218da0102a1SMichael Halcrow return rc; 219da0102a1SMichael Halcrow } 220da0102a1SMichael Halcrow 221da0102a1SMichael Halcrow /** 222da0102a1SMichael Halcrow * ecryptfs_read_lower 223da0102a1SMichael Halcrow * @data: The read data is stored here by this function 224da0102a1SMichael Halcrow * @offset: Byte offset in the lower file from which to read the data 225da0102a1SMichael Halcrow * @size: Number of bytes to read from @offset of the lower file and 226da0102a1SMichael Halcrow * store into @data 227da0102a1SMichael Halcrow * @ecryptfs_inode: The eCryptfs inode 228da0102a1SMichael Halcrow * 229da0102a1SMichael Halcrow * Read @size bytes of data at byte offset @offset from the lower 230da0102a1SMichael Halcrow * inode into memory location @data. 231da0102a1SMichael Halcrow * 232da0102a1SMichael Halcrow * Returns zero on success; non-zero on error 233da0102a1SMichael Halcrow */ 234da0102a1SMichael Halcrow int ecryptfs_read_lower(char *data, loff_t offset, size_t size, 235da0102a1SMichael Halcrow struct inode *ecryptfs_inode) 236da0102a1SMichael Halcrow { 237da0102a1SMichael Halcrow struct ecryptfs_inode_info *inode_info = 238da0102a1SMichael Halcrow ecryptfs_inode_to_private(ecryptfs_inode); 239da0102a1SMichael Halcrow ssize_t octets_read; 240da0102a1SMichael Halcrow mm_segment_t fs_save; 241da0102a1SMichael Halcrow int rc = 0; 242da0102a1SMichael Halcrow 243da0102a1SMichael Halcrow mutex_lock(&inode_info->lower_file_mutex); 244da0102a1SMichael Halcrow BUG_ON(!inode_info->lower_file); 245da0102a1SMichael Halcrow inode_info->lower_file->f_pos = offset; 246da0102a1SMichael Halcrow fs_save = get_fs(); 247da0102a1SMichael Halcrow set_fs(get_ds()); 248da0102a1SMichael Halcrow octets_read = vfs_read(inode_info->lower_file, data, size, 249da0102a1SMichael Halcrow &inode_info->lower_file->f_pos); 250da0102a1SMichael Halcrow set_fs(fs_save); 251da0102a1SMichael Halcrow if (octets_read < 0) { 252da0102a1SMichael Halcrow printk(KERN_ERR "%s: octets_read = [%td]; " 25318d1dbf1SHarvey Harrison "expected [%td]\n", __func__, octets_read, size); 254da0102a1SMichael Halcrow rc = -EINVAL; 255da0102a1SMichael Halcrow } 256da0102a1SMichael Halcrow mutex_unlock(&inode_info->lower_file_mutex); 257da0102a1SMichael Halcrow return rc; 258da0102a1SMichael Halcrow } 259da0102a1SMichael Halcrow 260da0102a1SMichael Halcrow /** 261da0102a1SMichael Halcrow * ecryptfs_read_lower_page_segment 262da0102a1SMichael Halcrow * @page_for_ecryptfs: The page into which data for eCryptfs will be 263da0102a1SMichael Halcrow * written 264da0102a1SMichael Halcrow * @offset_in_page: Offset in @page_for_ecryptfs from which to start 265da0102a1SMichael Halcrow * writing 266da0102a1SMichael Halcrow * @size: The number of bytes to write into @page_for_ecryptfs 267da0102a1SMichael Halcrow * @ecryptfs_inode: The eCryptfs inode 268da0102a1SMichael Halcrow * 269da0102a1SMichael Halcrow * Determines the byte offset in the file for the given page and 270da0102a1SMichael Halcrow * offset within the page, maps the page, and makes the call to read 271da0102a1SMichael Halcrow * the contents of @page_for_ecryptfs from the lower inode. 272da0102a1SMichael Halcrow * 273da0102a1SMichael Halcrow * Returns zero on success; non-zero otherwise 274da0102a1SMichael Halcrow */ 275da0102a1SMichael Halcrow int ecryptfs_read_lower_page_segment(struct page *page_for_ecryptfs, 276da0102a1SMichael Halcrow pgoff_t page_index, 277da0102a1SMichael Halcrow size_t offset_in_page, size_t size, 278da0102a1SMichael Halcrow struct inode *ecryptfs_inode) 279da0102a1SMichael Halcrow { 280da0102a1SMichael Halcrow char *virt; 281da0102a1SMichael Halcrow loff_t offset; 282da0102a1SMichael Halcrow int rc; 283da0102a1SMichael Halcrow 284d6a13c17SMichael Halcrow offset = ((((loff_t)page_index) << PAGE_CACHE_SHIFT) + offset_in_page); 285da0102a1SMichael Halcrow virt = kmap(page_for_ecryptfs); 286da0102a1SMichael Halcrow rc = ecryptfs_read_lower(virt, offset, size, ecryptfs_inode); 287da0102a1SMichael Halcrow kunmap(page_for_ecryptfs); 28816a72c45SMichael Halcrow flush_dcache_page(page_for_ecryptfs); 289da0102a1SMichael Halcrow return rc; 290da0102a1SMichael Halcrow } 291da0102a1SMichael Halcrow 2927896b631SAdrian Bunk #if 0 293da0102a1SMichael Halcrow /** 294da0102a1SMichael Halcrow * ecryptfs_read 295da0102a1SMichael Halcrow * @data: The virtual address into which to write the data read (and 296da0102a1SMichael Halcrow * possibly decrypted) from the lower file 297da0102a1SMichael Halcrow * @offset: The offset in the decrypted view of the file from which to 298da0102a1SMichael Halcrow * read into @data 299da0102a1SMichael Halcrow * @size: The number of bytes to read into @data 300da0102a1SMichael Halcrow * @ecryptfs_file: The eCryptfs file from which to read 301da0102a1SMichael Halcrow * 302da0102a1SMichael Halcrow * Read an arbitrary amount of data from an arbitrary location in the 303da0102a1SMichael Halcrow * eCryptfs page cache. This is done on an extent-by-extent basis; 304da0102a1SMichael Halcrow * individual extents are decrypted and read from the lower page 305da0102a1SMichael Halcrow * cache (via VFS reads). This function takes care of all the 306da0102a1SMichael Halcrow * address translation to locations in the lower filesystem. 307da0102a1SMichael Halcrow * 308da0102a1SMichael Halcrow * Returns zero on success; non-zero otherwise 309da0102a1SMichael Halcrow */ 310da0102a1SMichael Halcrow int ecryptfs_read(char *data, loff_t offset, size_t size, 311da0102a1SMichael Halcrow struct file *ecryptfs_file) 312da0102a1SMichael Halcrow { 313da0102a1SMichael Halcrow struct page *ecryptfs_page; 314da0102a1SMichael Halcrow char *ecryptfs_page_virt; 315d6a13c17SMichael Halcrow loff_t ecryptfs_file_size = 316d6a13c17SMichael Halcrow i_size_read(ecryptfs_file->f_dentry->d_inode); 317da0102a1SMichael Halcrow loff_t data_offset = 0; 318da0102a1SMichael Halcrow loff_t pos; 319da0102a1SMichael Halcrow int rc = 0; 320da0102a1SMichael Halcrow 321da0102a1SMichael Halcrow if ((offset + size) > ecryptfs_file_size) { 322da0102a1SMichael Halcrow rc = -EINVAL; 323da0102a1SMichael Halcrow printk(KERN_ERR "%s: Attempt to read data past the end of the " 324da0102a1SMichael Halcrow "file; offset = [%lld]; size = [%td]; " 325da0102a1SMichael Halcrow "ecryptfs_file_size = [%lld]\n", 32618d1dbf1SHarvey Harrison __func__, offset, size, ecryptfs_file_size); 327da0102a1SMichael Halcrow goto out; 328da0102a1SMichael Halcrow } 329da0102a1SMichael Halcrow pos = offset; 330da0102a1SMichael Halcrow while (pos < (offset + size)) { 331da0102a1SMichael Halcrow pgoff_t ecryptfs_page_idx = (pos >> PAGE_CACHE_SHIFT); 332da0102a1SMichael Halcrow size_t start_offset_in_page = (pos & ~PAGE_CACHE_MASK); 333da0102a1SMichael Halcrow size_t num_bytes = (PAGE_CACHE_SIZE - start_offset_in_page); 334da0102a1SMichael Halcrow size_t total_remaining_bytes = ((offset + size) - pos); 335da0102a1SMichael Halcrow 336da0102a1SMichael Halcrow if (num_bytes > total_remaining_bytes) 337da0102a1SMichael Halcrow num_bytes = total_remaining_bytes; 33816a72c45SMichael Halcrow ecryptfs_page = ecryptfs_get_locked_page(ecryptfs_file, 339da0102a1SMichael Halcrow ecryptfs_page_idx); 340da0102a1SMichael Halcrow if (IS_ERR(ecryptfs_page)) { 341da0102a1SMichael Halcrow rc = PTR_ERR(ecryptfs_page); 342da0102a1SMichael Halcrow printk(KERN_ERR "%s: Error getting page at " 343da0102a1SMichael Halcrow "index [%ld] from eCryptfs inode " 34418d1dbf1SHarvey Harrison "mapping; rc = [%d]\n", __func__, 345da0102a1SMichael Halcrow ecryptfs_page_idx, rc); 346da0102a1SMichael Halcrow goto out; 347da0102a1SMichael Halcrow } 348da0102a1SMichael Halcrow ecryptfs_page_virt = kmap_atomic(ecryptfs_page, KM_USER0); 349da0102a1SMichael Halcrow memcpy((data + data_offset), 350da0102a1SMichael Halcrow ((char *)ecryptfs_page_virt + start_offset_in_page), 351da0102a1SMichael Halcrow num_bytes); 352da0102a1SMichael Halcrow kunmap_atomic(ecryptfs_page_virt, KM_USER0); 35316a72c45SMichael Halcrow flush_dcache_page(ecryptfs_page); 35416a72c45SMichael Halcrow SetPageUptodate(ecryptfs_page); 35516a72c45SMichael Halcrow unlock_page(ecryptfs_page); 356da0102a1SMichael Halcrow page_cache_release(ecryptfs_page); 357da0102a1SMichael Halcrow pos += num_bytes; 358da0102a1SMichael Halcrow data_offset += num_bytes; 359da0102a1SMichael Halcrow } 360da0102a1SMichael Halcrow out: 361da0102a1SMichael Halcrow return rc; 362da0102a1SMichael Halcrow } 3637896b631SAdrian Bunk #endif /* 0 */ 364