Commit | Line | Data |
---|---|---|
237fead6 MH |
1 | /** |
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. | |
6 | * | |
7 | * Copyright (C) 1997-2003 Erez Zadok | |
8 | * Copyright (C) 2001-2003 Stony Brook University | |
dd2a3b7a | 9 | * Copyright (C) 2004-2007 International Business Machines Corp. |
237fead6 MH |
10 | * Author(s): Michael A. Halcrow <mahalcro@us.ibm.com> |
11 | * | |
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. | |
16 | * | |
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. | |
21 | * | |
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 | |
25 | * 02111-1307, USA. | |
26 | */ | |
27 | ||
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> | |
0a688ad7 | 35 | #include <asm/unaligned.h> |
237fead6 MH |
36 | #include "ecryptfs_kernel.h" |
37 | ||
237fead6 | 38 | /** |
16a72c45 | 39 | * ecryptfs_get_locked_page |
237fead6 MH |
40 | * |
41 | * Get one page from cache or lower f/s, return error otherwise. | |
42 | * | |
16a72c45 | 43 | * Returns locked and up-to-date page (if ok), with increased |
237fead6 MH |
44 | * refcnt. |
45 | */ | |
16a72c45 | 46 | struct page *ecryptfs_get_locked_page(struct file *file, loff_t index) |
237fead6 | 47 | { |
237fead6 MH |
48 | struct dentry *dentry; |
49 | struct inode *inode; | |
50 | struct address_space *mapping; | |
16a72c45 | 51 | struct page *page; |
237fead6 | 52 | |
bd243a4b | 53 | dentry = file->f_path.dentry; |
237fead6 MH |
54 | inode = dentry->d_inode; |
55 | mapping = inode->i_mapping; | |
16a72c45 MH |
56 | page = read_mapping_page(mapping, index, (void *)file); |
57 | if (!IS_ERR(page)) | |
58 | lock_page(page); | |
59 | return page; | |
237fead6 MH |
60 | } |
61 | ||
237fead6 MH |
62 | /** |
63 | * ecryptfs_writepage | |
64 | * @page: Page that is locked before this call is made | |
65 | * | |
66 | * Returns zero on success; non-zero otherwise | |
67 | */ | |
68 | static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) | |
69 | { | |
237fead6 MH |
70 | int rc; |
71 | ||
0216f7f7 | 72 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
73 | if (rc) { |
74 | ecryptfs_printk(KERN_WARNING, "Error encrypting " | |
75 | "page (upper index [0x%.16x])\n", page->index); | |
76 | ClearPageUptodate(page); | |
77 | goto out; | |
78 | } | |
79 | SetPageUptodate(page); | |
80 | unlock_page(page); | |
81 | out: | |
82 | return rc; | |
83 | } | |
84 | ||
e77a56dd MH |
85 | /** |
86 | * Header Extent: | |
87 | * Octets 0-7: Unencrypted file size (big-endian) | |
88 | * Octets 8-15: eCryptfs special marker | |
89 | * Octets 16-19: Flags | |
90 | * Octet 16: File format version number (between 0 and 255) | |
91 | * Octets 17-18: Reserved | |
92 | * Octet 19: Bit 1 (lsb): Reserved | |
93 | * Bit 2: Encrypted? | |
94 | * Bits 3-8: Reserved | |
95 | * Octets 20-23: Header extent size (big-endian) | |
96 | * Octets 24-25: Number of header extents at front of file | |
97 | * (big-endian) | |
98 | * Octet 26: Begin RFC 2440 authentication token packet set | |
99 | */ | |
100 | static void set_header_info(char *page_virt, | |
101 | struct ecryptfs_crypt_stat *crypt_stat) | |
102 | { | |
103 | size_t written; | |
cc11beff MH |
104 | size_t save_num_header_bytes_at_front = |
105 | crypt_stat->num_header_bytes_at_front; | |
e77a56dd | 106 | |
cc11beff MH |
107 | crypt_stat->num_header_bytes_at_front = |
108 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
e77a56dd | 109 | ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written); |
cc11beff MH |
110 | crypt_stat->num_header_bytes_at_front = |
111 | save_num_header_bytes_at_front; | |
e77a56dd | 112 | } |
237fead6 | 113 | |
bf12be1c MH |
114 | /** |
115 | * ecryptfs_copy_up_encrypted_with_header | |
116 | * @page: Sort of a ``virtual'' representation of the encrypted lower | |
117 | * file. The actual lower file does not have the metadata in | |
118 | * the header. This is locked. | |
119 | * @crypt_stat: The eCryptfs inode's cryptographic context | |
120 | * | |
121 | * The ``view'' is the version of the file that userspace winds up | |
122 | * seeing, with the header information inserted. | |
123 | */ | |
124 | static int | |
125 | ecryptfs_copy_up_encrypted_with_header(struct page *page, | |
126 | struct ecryptfs_crypt_stat *crypt_stat) | |
127 | { | |
128 | loff_t extent_num_in_page = 0; | |
129 | loff_t num_extents_per_page = (PAGE_CACHE_SIZE | |
130 | / crypt_stat->extent_size); | |
131 | int rc = 0; | |
132 | ||
133 | while (extent_num_in_page < num_extents_per_page) { | |
d6a13c17 MH |
134 | loff_t view_extent_num = ((((loff_t)page->index) |
135 | * num_extents_per_page) | |
bf12be1c | 136 | + extent_num_in_page); |
cc11beff MH |
137 | size_t num_header_extents_at_front = |
138 | (crypt_stat->num_header_bytes_at_front | |
139 | / crypt_stat->extent_size); | |
bf12be1c | 140 | |
cc11beff | 141 | if (view_extent_num < num_header_extents_at_front) { |
bf12be1c MH |
142 | /* This is a header extent */ |
143 | char *page_virt; | |
144 | ||
145 | page_virt = kmap_atomic(page, KM_USER0); | |
146 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
147 | /* TODO: Support more than one header extent */ | |
148 | if (view_extent_num == 0) { | |
149 | rc = ecryptfs_read_xattr_region( | |
150 | page_virt, page->mapping->host); | |
151 | set_header_info(page_virt, crypt_stat); | |
152 | } | |
153 | kunmap_atomic(page_virt, KM_USER0); | |
154 | flush_dcache_page(page); | |
155 | if (rc) { | |
bf12be1c | 156 | printk(KERN_ERR "%s: Error reading xattr " |
18d1dbf1 | 157 | "region; rc = [%d]\n", __func__, rc); |
bf12be1c MH |
158 | goto out; |
159 | } | |
bf12be1c MH |
160 | } else { |
161 | /* This is an encrypted data extent */ | |
162 | loff_t lower_offset = | |
cc11beff MH |
163 | ((view_extent_num * crypt_stat->extent_size) |
164 | - crypt_stat->num_header_bytes_at_front); | |
bf12be1c MH |
165 | |
166 | rc = ecryptfs_read_lower_page_segment( | |
167 | page, (lower_offset >> PAGE_CACHE_SHIFT), | |
168 | (lower_offset & ~PAGE_CACHE_MASK), | |
169 | crypt_stat->extent_size, page->mapping->host); | |
170 | if (rc) { | |
171 | printk(KERN_ERR "%s: Error attempting to read " | |
172 | "extent at offset [%lld] in the lower " | |
18d1dbf1 | 173 | "file; rc = [%d]\n", __func__, |
bf12be1c MH |
174 | lower_offset, rc); |
175 | goto out; | |
176 | } | |
177 | } | |
178 | extent_num_in_page++; | |
179 | } | |
180 | out: | |
181 | return rc; | |
182 | } | |
183 | ||
237fead6 MH |
184 | /** |
185 | * ecryptfs_readpage | |
bf12be1c MH |
186 | * @file: An eCryptfs file |
187 | * @page: Page from eCryptfs inode mapping into which to stick the read data | |
237fead6 MH |
188 | * |
189 | * Read in a page, decrypting if necessary. | |
190 | * | |
191 | * Returns zero on success; non-zero on error. | |
192 | */ | |
193 | static int ecryptfs_readpage(struct file *file, struct page *page) | |
194 | { | |
bf12be1c MH |
195 | struct ecryptfs_crypt_stat *crypt_stat = |
196 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; | |
237fead6 | 197 | int rc = 0; |
237fead6 | 198 | |
237fead6 | 199 | if (!crypt_stat |
e2bd99ec MH |
200 | || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) |
201 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
237fead6 MH |
202 | ecryptfs_printk(KERN_DEBUG, |
203 | "Passing through unencrypted page\n"); | |
bf12be1c MH |
204 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
205 | PAGE_CACHE_SIZE, | |
206 | page->mapping->host); | |
e77a56dd MH |
207 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
208 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
bf12be1c MH |
209 | rc = ecryptfs_copy_up_encrypted_with_header(page, |
210 | crypt_stat); | |
211 | if (rc) { | |
212 | printk(KERN_ERR "%s: Error attempting to copy " | |
213 | "the encrypted content from the lower " | |
214 | "file whilst inserting the metadata " | |
215 | "from the xattr into the header; rc = " | |
18d1dbf1 | 216 | "[%d]\n", __func__, rc); |
bf12be1c | 217 | goto out; |
e77a56dd | 218 | } |
bf12be1c | 219 | |
e77a56dd | 220 | } else { |
bf12be1c MH |
221 | rc = ecryptfs_read_lower_page_segment( |
222 | page, page->index, 0, PAGE_CACHE_SIZE, | |
223 | page->mapping->host); | |
e77a56dd MH |
224 | if (rc) { |
225 | printk(KERN_ERR "Error reading page; rc = " | |
226 | "[%d]\n", rc); | |
227 | goto out; | |
228 | } | |
229 | } | |
237fead6 | 230 | } else { |
0216f7f7 | 231 | rc = ecryptfs_decrypt_page(page); |
237fead6 | 232 | if (rc) { |
237fead6 MH |
233 | ecryptfs_printk(KERN_ERR, "Error decrypting page; " |
234 | "rc = [%d]\n", rc); | |
235 | goto out; | |
236 | } | |
237 | } | |
237fead6 | 238 | out: |
16a72c45 MH |
239 | if (rc) |
240 | ClearPageUptodate(page); | |
241 | else | |
242 | SetPageUptodate(page); | |
237fead6 MH |
243 | ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n", |
244 | page->index); | |
245 | unlock_page(page); | |
246 | return rc; | |
247 | } | |
248 | ||
dd2a3b7a MH |
249 | /** |
250 | * Called with lower inode mutex held. | |
251 | */ | |
237fead6 MH |
252 | static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) |
253 | { | |
254 | struct inode *inode = page->mapping->host; | |
255 | int end_byte_in_page; | |
237fead6 | 256 | |
9d8b8ce5 MH |
257 | if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index) |
258 | goto out; | |
259 | end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; | |
260 | if (to > end_byte_in_page) | |
261 | end_byte_in_page = to; | |
eebd2aa3 | 262 | zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE); |
237fead6 | 263 | out: |
9d8b8ce5 | 264 | return 0; |
237fead6 MH |
265 | } |
266 | ||
e4465fda | 267 | /** |
807b7ebe | 268 | * ecryptfs_write_begin |
e4465fda | 269 | * @file: The eCryptfs file |
807b7ebe BP |
270 | * @mapping: The eCryptfs object |
271 | * @pos: The file offset at which to start writing | |
272 | * @len: Length of the write | |
273 | * @flags: Various flags | |
274 | * @pagep: Pointer to return the page | |
275 | * @fsdata: Pointer to return fs data (unused) | |
e4465fda MH |
276 | * |
277 | * This function must zero any hole we create | |
278 | * | |
279 | * Returns zero on success; non-zero otherwise | |
280 | */ | |
807b7ebe BP |
281 | static int ecryptfs_write_begin(struct file *file, |
282 | struct address_space *mapping, | |
283 | loff_t pos, unsigned len, unsigned flags, | |
284 | struct page **pagep, void **fsdata) | |
237fead6 | 285 | { |
807b7ebe BP |
286 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
287 | struct page *page; | |
7a3f595c | 288 | loff_t prev_page_end_size; |
e4465fda | 289 | int rc = 0; |
237fead6 | 290 | |
54566b2c | 291 | page = grab_cache_page_write_begin(mapping, index, flags); |
807b7ebe BP |
292 | if (!page) |
293 | return -ENOMEM; | |
294 | *pagep = page; | |
295 | ||
16a72c45 | 296 | if (!PageUptodate(page)) { |
e4465fda MH |
297 | struct ecryptfs_crypt_stat *crypt_stat = |
298 | &ecryptfs_inode_to_private( | |
299 | file->f_path.dentry->d_inode)->crypt_stat; | |
300 | ||
301 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) | |
302 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
303 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe | 304 | page, index, 0, PAGE_CACHE_SIZE, mapping->host); |
e4465fda MH |
305 | if (rc) { |
306 | printk(KERN_ERR "%s: Error attemping to read " | |
307 | "lower page segment; rc = [%d]\n", | |
18d1dbf1 | 308 | __func__, rc); |
e4465fda MH |
309 | ClearPageUptodate(page); |
310 | goto out; | |
311 | } else | |
312 | SetPageUptodate(page); | |
313 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { | |
314 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
315 | rc = ecryptfs_copy_up_encrypted_with_header( | |
316 | page, crypt_stat); | |
317 | if (rc) { | |
318 | printk(KERN_ERR "%s: Error attempting " | |
319 | "to copy the encrypted content " | |
320 | "from the lower file whilst " | |
321 | "inserting the metadata from " | |
322 | "the xattr into the header; rc " | |
18d1dbf1 | 323 | "= [%d]\n", __func__, rc); |
e4465fda MH |
324 | ClearPageUptodate(page); |
325 | goto out; | |
326 | } | |
327 | SetPageUptodate(page); | |
328 | } else { | |
329 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe BP |
330 | page, index, 0, PAGE_CACHE_SIZE, |
331 | mapping->host); | |
e4465fda MH |
332 | if (rc) { |
333 | printk(KERN_ERR "%s: Error reading " | |
334 | "page; rc = [%d]\n", | |
18d1dbf1 | 335 | __func__, rc); |
e4465fda MH |
336 | ClearPageUptodate(page); |
337 | goto out; | |
338 | } | |
339 | SetPageUptodate(page); | |
340 | } | |
341 | } else { | |
342 | rc = ecryptfs_decrypt_page(page); | |
343 | if (rc) { | |
344 | printk(KERN_ERR "%s: Error decrypting page " | |
345 | "at index [%ld]; rc = [%d]\n", | |
18d1dbf1 | 346 | __func__, page->index, rc); |
e4465fda MH |
347 | ClearPageUptodate(page); |
348 | goto out; | |
349 | } | |
16a72c45 | 350 | SetPageUptodate(page); |
e4465fda | 351 | } |
16a72c45 | 352 | } |
807b7ebe | 353 | prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT); |
e4465fda MH |
354 | /* If creating a page or more of holes, zero them out via truncate. |
355 | * Note, this will increase i_size. */ | |
807b7ebe | 356 | if (index != 0) { |
7a3f595c | 357 | if (prev_page_end_size > i_size_read(page->mapping->host)) { |
240e2df5 | 358 | rc = ecryptfs_truncate(file->f_path.dentry, |
7a3f595c | 359 | prev_page_end_size); |
240e2df5 | 360 | if (rc) { |
e4465fda | 361 | printk(KERN_ERR "%s: Error on attempt to " |
240e2df5 | 362 | "truncate to (higher) offset [%lld];" |
18d1dbf1 | 363 | " rc = [%d]\n", __func__, |
e4465fda | 364 | prev_page_end_size, rc); |
240e2df5 MH |
365 | goto out; |
366 | } | |
53a2731f | 367 | } |
7a3f595c | 368 | } |
e4465fda MH |
369 | /* Writing to a new page, and creating a small hole from start |
370 | * of page? Zero it out. */ | |
807b7ebe BP |
371 | if ((i_size_read(mapping->host) == prev_page_end_size) |
372 | && (pos != 0)) | |
eebd2aa3 | 373 | zero_user(page, 0, PAGE_CACHE_SIZE); |
237fead6 MH |
374 | out: |
375 | return rc; | |
376 | } | |
377 | ||
237fead6 MH |
378 | /** |
379 | * ecryptfs_write_inode_size_to_header | |
380 | * | |
381 | * Writes the lower file size to the first 8 bytes of the header. | |
382 | * | |
383 | * Returns zero on success; non-zero on error. | |
384 | */ | |
0216f7f7 | 385 | static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode) |
237fead6 | 386 | { |
0216f7f7 MH |
387 | char *file_size_virt; |
388 | int rc; | |
237fead6 | 389 | |
0216f7f7 MH |
390 | file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL); |
391 | if (!file_size_virt) { | |
392 | rc = -ENOMEM; | |
ae73fc09 MH |
393 | goto out; |
394 | } | |
0a688ad7 | 395 | put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt); |
0216f7f7 MH |
396 | rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0, |
397 | sizeof(u64)); | |
398 | kfree(file_size_virt); | |
96a7b9c2 | 399 | if (rc < 0) |
0216f7f7 | 400 | printk(KERN_ERR "%s: Error writing file size to header; " |
18d1dbf1 | 401 | "rc = [%d]\n", __func__, rc); |
96a7b9c2 TH |
402 | else |
403 | rc = 0; | |
237fead6 MH |
404 | out: |
405 | return rc; | |
406 | } | |
407 | ||
0216f7f7 MH |
408 | struct kmem_cache *ecryptfs_xattr_cache; |
409 | ||
410 | static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) | |
dd2a3b7a MH |
411 | { |
412 | ssize_t size; | |
413 | void *xattr_virt; | |
0216f7f7 MH |
414 | struct dentry *lower_dentry = |
415 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
416 | struct inode *lower_inode = lower_dentry->d_inode; | |
dd2a3b7a MH |
417 | int rc; |
418 | ||
0216f7f7 MH |
419 | if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { |
420 | printk(KERN_WARNING | |
421 | "No support for setting xattr in lower filesystem\n"); | |
422 | rc = -ENOSYS; | |
423 | goto out; | |
424 | } | |
dd2a3b7a MH |
425 | xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); |
426 | if (!xattr_virt) { | |
427 | printk(KERN_ERR "Out of memory whilst attempting to write " | |
428 | "inode size to xattr\n"); | |
429 | rc = -ENOMEM; | |
430 | goto out; | |
431 | } | |
0216f7f7 MH |
432 | mutex_lock(&lower_inode->i_mutex); |
433 | size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME, | |
434 | xattr_virt, PAGE_CACHE_SIZE); | |
dd2a3b7a MH |
435 | if (size < 0) |
436 | size = 8; | |
0a688ad7 | 437 | put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); |
0216f7f7 MH |
438 | rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME, |
439 | xattr_virt, size, 0); | |
440 | mutex_unlock(&lower_inode->i_mutex); | |
dd2a3b7a MH |
441 | if (rc) |
442 | printk(KERN_ERR "Error whilst attempting to write inode size " | |
443 | "to lower file xattr; rc = [%d]\n", rc); | |
444 | kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); | |
445 | out: | |
446 | return rc; | |
447 | } | |
448 | ||
0216f7f7 | 449 | int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) |
dd2a3b7a MH |
450 | { |
451 | struct ecryptfs_crypt_stat *crypt_stat; | |
452 | ||
0216f7f7 | 453 | crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
13a791b4 | 454 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
dd2a3b7a | 455 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
0216f7f7 | 456 | return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode); |
dd2a3b7a | 457 | else |
0216f7f7 | 458 | return ecryptfs_write_inode_size_to_header(ecryptfs_inode); |
dd2a3b7a MH |
459 | } |
460 | ||
237fead6 | 461 | /** |
807b7ebe | 462 | * ecryptfs_write_end |
237fead6 | 463 | * @file: The eCryptfs file object |
807b7ebe BP |
464 | * @mapping: The eCryptfs object |
465 | * @pos: The file position | |
466 | * @len: The length of the data (unused) | |
467 | * @copied: The amount of data copied | |
237fead6 | 468 | * @page: The eCryptfs page |
807b7ebe | 469 | * @fsdata: The fsdata (unused) |
237fead6 MH |
470 | * |
471 | * This is where we encrypt the data and pass the encrypted data to | |
472 | * the lower filesystem. In OpenPGP-compatible mode, we operate on | |
473 | * entire underlying packets. | |
474 | */ | |
807b7ebe BP |
475 | static int ecryptfs_write_end(struct file *file, |
476 | struct address_space *mapping, | |
477 | loff_t pos, unsigned len, unsigned copied, | |
478 | struct page *page, void *fsdata) | |
237fead6 | 479 | { |
807b7ebe BP |
480 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
481 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
482 | unsigned to = from + copied; | |
483 | struct inode *ecryptfs_inode = mapping->host; | |
bf12be1c MH |
484 | struct ecryptfs_crypt_stat *crypt_stat = |
485 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; | |
237fead6 MH |
486 | int rc; |
487 | ||
e2bd99ec | 488 | if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { |
237fead6 MH |
489 | ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " |
490 | "crypt_stat at memory location [%p]\n", crypt_stat); | |
e2bd99ec | 491 | crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); |
237fead6 MH |
492 | } else |
493 | ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); | |
494 | ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" | |
807b7ebe | 495 | "(page w/ index = [0x%.16x], to = [%d])\n", index, to); |
13a791b4 TH |
496 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
497 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0, | |
498 | to); | |
499 | if (!rc) { | |
500 | rc = copied; | |
501 | fsstack_copy_inode_size(ecryptfs_inode, | |
502 | ecryptfs_inode_to_lower(ecryptfs_inode)); | |
503 | } | |
504 | goto out; | |
505 | } | |
bf12be1c | 506 | /* Fills in zeros if 'to' goes beyond inode size */ |
237fead6 MH |
507 | rc = fill_zeros_to_end_of_page(page, to); |
508 | if (rc) { | |
509 | ecryptfs_printk(KERN_WARNING, "Error attempting to fill " | |
807b7ebe | 510 | "zeros in page with index = [0x%.16x]\n", index); |
237fead6 MH |
511 | goto out; |
512 | } | |
0216f7f7 | 513 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
514 | if (rc) { |
515 | ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " | |
807b7ebe | 516 | "index [0x%.16x])\n", index); |
237fead6 MH |
517 | goto out; |
518 | } | |
807b7ebe BP |
519 | if (pos + copied > i_size_read(ecryptfs_inode)) { |
520 | i_size_write(ecryptfs_inode, pos + copied); | |
237fead6 | 521 | ecryptfs_printk(KERN_DEBUG, "Expanded file size to " |
bf12be1c | 522 | "[0x%.16x]\n", i_size_read(ecryptfs_inode)); |
237fead6 | 523 | } |
bf12be1c | 524 | rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); |
dd2a3b7a MH |
525 | if (rc) |
526 | printk(KERN_ERR "Error writing inode size to metadata; " | |
527 | "rc = [%d]\n", rc); | |
807b7ebe BP |
528 | else |
529 | rc = copied; | |
237fead6 | 530 | out: |
807b7ebe BP |
531 | unlock_page(page); |
532 | page_cache_release(page); | |
237fead6 MH |
533 | return rc; |
534 | } | |
535 | ||
237fead6 MH |
536 | static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) |
537 | { | |
538 | int rc = 0; | |
539 | struct inode *inode; | |
540 | struct inode *lower_inode; | |
541 | ||
542 | inode = (struct inode *)mapping->host; | |
543 | lower_inode = ecryptfs_inode_to_lower(inode); | |
544 | if (lower_inode->i_mapping->a_ops->bmap) | |
545 | rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, | |
546 | block); | |
547 | return rc; | |
548 | } | |
549 | ||
7f09410b | 550 | const struct address_space_operations ecryptfs_aops = { |
237fead6 MH |
551 | .writepage = ecryptfs_writepage, |
552 | .readpage = ecryptfs_readpage, | |
807b7ebe BP |
553 | .write_begin = ecryptfs_write_begin, |
554 | .write_end = ecryptfs_write_end, | |
237fead6 | 555 | .bmap = ecryptfs_bmap, |
237fead6 | 556 | }; |