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Commit | Line | Data |
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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> | |
5a0e3ad6 | 35 | #include <linux/slab.h> |
0a688ad7 | 36 | #include <asm/unaligned.h> |
237fead6 MH |
37 | #include "ecryptfs_kernel.h" |
38 | ||
237fead6 | 39 | /** |
16a72c45 | 40 | * ecryptfs_get_locked_page |
237fead6 MH |
41 | * |
42 | * Get one page from cache or lower f/s, return error otherwise. | |
43 | * | |
16a72c45 | 44 | * Returns locked and up-to-date page (if ok), with increased |
237fead6 MH |
45 | * refcnt. |
46 | */ | |
16a72c45 | 47 | struct page *ecryptfs_get_locked_page(struct file *file, loff_t index) |
237fead6 | 48 | { |
237fead6 MH |
49 | struct dentry *dentry; |
50 | struct inode *inode; | |
51 | struct address_space *mapping; | |
16a72c45 | 52 | struct page *page; |
237fead6 | 53 | |
bd243a4b | 54 | dentry = file->f_path.dentry; |
237fead6 MH |
55 | inode = dentry->d_inode; |
56 | mapping = inode->i_mapping; | |
16a72c45 MH |
57 | page = read_mapping_page(mapping, index, (void *)file); |
58 | if (!IS_ERR(page)) | |
59 | lock_page(page); | |
60 | return page; | |
237fead6 MH |
61 | } |
62 | ||
237fead6 MH |
63 | /** |
64 | * ecryptfs_writepage | |
65 | * @page: Page that is locked before this call is made | |
66 | * | |
67 | * Returns zero on success; non-zero otherwise | |
68 | */ | |
69 | static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) | |
70 | { | |
237fead6 MH |
71 | int rc; |
72 | ||
0216f7f7 | 73 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
74 | if (rc) { |
75 | ecryptfs_printk(KERN_WARNING, "Error encrypting " | |
76 | "page (upper index [0x%.16x])\n", page->index); | |
77 | ClearPageUptodate(page); | |
78 | goto out; | |
79 | } | |
80 | SetPageUptodate(page); | |
81 | unlock_page(page); | |
82 | out: | |
83 | return rc; | |
84 | } | |
85 | ||
e77a56dd MH |
86 | /** |
87 | * Header Extent: | |
88 | * Octets 0-7: Unencrypted file size (big-endian) | |
89 | * Octets 8-15: eCryptfs special marker | |
90 | * Octets 16-19: Flags | |
91 | * Octet 16: File format version number (between 0 and 255) | |
92 | * Octets 17-18: Reserved | |
93 | * Octet 19: Bit 1 (lsb): Reserved | |
94 | * Bit 2: Encrypted? | |
95 | * Bits 3-8: Reserved | |
96 | * Octets 20-23: Header extent size (big-endian) | |
97 | * Octets 24-25: Number of header extents at front of file | |
98 | * (big-endian) | |
99 | * Octet 26: Begin RFC 2440 authentication token packet set | |
100 | */ | |
101 | static void set_header_info(char *page_virt, | |
102 | struct ecryptfs_crypt_stat *crypt_stat) | |
103 | { | |
104 | size_t written; | |
cc11beff MH |
105 | size_t save_num_header_bytes_at_front = |
106 | crypt_stat->num_header_bytes_at_front; | |
e77a56dd | 107 | |
cc11beff MH |
108 | crypt_stat->num_header_bytes_at_front = |
109 | ECRYPTFS_MINIMUM_HEADER_EXTENT_SIZE; | |
e77a56dd | 110 | ecryptfs_write_header_metadata(page_virt + 20, crypt_stat, &written); |
cc11beff MH |
111 | crypt_stat->num_header_bytes_at_front = |
112 | save_num_header_bytes_at_front; | |
e77a56dd | 113 | } |
237fead6 | 114 | |
bf12be1c MH |
115 | /** |
116 | * ecryptfs_copy_up_encrypted_with_header | |
117 | * @page: Sort of a ``virtual'' representation of the encrypted lower | |
118 | * file. The actual lower file does not have the metadata in | |
119 | * the header. This is locked. | |
120 | * @crypt_stat: The eCryptfs inode's cryptographic context | |
121 | * | |
122 | * The ``view'' is the version of the file that userspace winds up | |
123 | * seeing, with the header information inserted. | |
124 | */ | |
125 | static int | |
126 | ecryptfs_copy_up_encrypted_with_header(struct page *page, | |
127 | struct ecryptfs_crypt_stat *crypt_stat) | |
128 | { | |
129 | loff_t extent_num_in_page = 0; | |
130 | loff_t num_extents_per_page = (PAGE_CACHE_SIZE | |
131 | / crypt_stat->extent_size); | |
132 | int rc = 0; | |
133 | ||
134 | while (extent_num_in_page < num_extents_per_page) { | |
d6a13c17 MH |
135 | loff_t view_extent_num = ((((loff_t)page->index) |
136 | * num_extents_per_page) | |
bf12be1c | 137 | + extent_num_in_page); |
cc11beff MH |
138 | size_t num_header_extents_at_front = |
139 | (crypt_stat->num_header_bytes_at_front | |
140 | / crypt_stat->extent_size); | |
bf12be1c | 141 | |
cc11beff | 142 | if (view_extent_num < num_header_extents_at_front) { |
bf12be1c MH |
143 | /* This is a header extent */ |
144 | char *page_virt; | |
145 | ||
146 | page_virt = kmap_atomic(page, KM_USER0); | |
147 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
148 | /* TODO: Support more than one header extent */ | |
149 | if (view_extent_num == 0) { | |
150 | rc = ecryptfs_read_xattr_region( | |
151 | page_virt, page->mapping->host); | |
152 | set_header_info(page_virt, crypt_stat); | |
153 | } | |
154 | kunmap_atomic(page_virt, KM_USER0); | |
155 | flush_dcache_page(page); | |
156 | if (rc) { | |
bf12be1c | 157 | printk(KERN_ERR "%s: Error reading xattr " |
18d1dbf1 | 158 | "region; rc = [%d]\n", __func__, rc); |
bf12be1c MH |
159 | goto out; |
160 | } | |
bf12be1c MH |
161 | } else { |
162 | /* This is an encrypted data extent */ | |
163 | loff_t lower_offset = | |
cc11beff MH |
164 | ((view_extent_num * crypt_stat->extent_size) |
165 | - crypt_stat->num_header_bytes_at_front); | |
bf12be1c MH |
166 | |
167 | rc = ecryptfs_read_lower_page_segment( | |
168 | page, (lower_offset >> PAGE_CACHE_SHIFT), | |
169 | (lower_offset & ~PAGE_CACHE_MASK), | |
170 | crypt_stat->extent_size, page->mapping->host); | |
171 | if (rc) { | |
172 | printk(KERN_ERR "%s: Error attempting to read " | |
173 | "extent at offset [%lld] in the lower " | |
18d1dbf1 | 174 | "file; rc = [%d]\n", __func__, |
bf12be1c MH |
175 | lower_offset, rc); |
176 | goto out; | |
177 | } | |
178 | } | |
179 | extent_num_in_page++; | |
180 | } | |
181 | out: | |
182 | return rc; | |
183 | } | |
184 | ||
237fead6 MH |
185 | /** |
186 | * ecryptfs_readpage | |
bf12be1c MH |
187 | * @file: An eCryptfs file |
188 | * @page: Page from eCryptfs inode mapping into which to stick the read data | |
237fead6 MH |
189 | * |
190 | * Read in a page, decrypting if necessary. | |
191 | * | |
192 | * Returns zero on success; non-zero on error. | |
193 | */ | |
194 | static int ecryptfs_readpage(struct file *file, struct page *page) | |
195 | { | |
bf12be1c MH |
196 | struct ecryptfs_crypt_stat *crypt_stat = |
197 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; | |
237fead6 | 198 | int rc = 0; |
237fead6 | 199 | |
237fead6 | 200 | if (!crypt_stat |
e2bd99ec MH |
201 | || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) |
202 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
237fead6 MH |
203 | ecryptfs_printk(KERN_DEBUG, |
204 | "Passing through unencrypted page\n"); | |
bf12be1c MH |
205 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
206 | PAGE_CACHE_SIZE, | |
207 | page->mapping->host); | |
e77a56dd MH |
208 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
209 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
bf12be1c MH |
210 | rc = ecryptfs_copy_up_encrypted_with_header(page, |
211 | crypt_stat); | |
212 | if (rc) { | |
213 | printk(KERN_ERR "%s: Error attempting to copy " | |
214 | "the encrypted content from the lower " | |
215 | "file whilst inserting the metadata " | |
216 | "from the xattr into the header; rc = " | |
18d1dbf1 | 217 | "[%d]\n", __func__, rc); |
bf12be1c | 218 | goto out; |
e77a56dd | 219 | } |
bf12be1c | 220 | |
e77a56dd | 221 | } else { |
bf12be1c MH |
222 | rc = ecryptfs_read_lower_page_segment( |
223 | page, page->index, 0, PAGE_CACHE_SIZE, | |
224 | page->mapping->host); | |
e77a56dd MH |
225 | if (rc) { |
226 | printk(KERN_ERR "Error reading page; rc = " | |
227 | "[%d]\n", rc); | |
228 | goto out; | |
229 | } | |
230 | } | |
237fead6 | 231 | } else { |
0216f7f7 | 232 | rc = ecryptfs_decrypt_page(page); |
237fead6 | 233 | if (rc) { |
237fead6 MH |
234 | ecryptfs_printk(KERN_ERR, "Error decrypting page; " |
235 | "rc = [%d]\n", rc); | |
236 | goto out; | |
237 | } | |
238 | } | |
237fead6 | 239 | out: |
16a72c45 MH |
240 | if (rc) |
241 | ClearPageUptodate(page); | |
242 | else | |
243 | SetPageUptodate(page); | |
237fead6 MH |
244 | ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16x]\n", |
245 | page->index); | |
246 | unlock_page(page); | |
247 | return rc; | |
248 | } | |
249 | ||
dd2a3b7a MH |
250 | /** |
251 | * Called with lower inode mutex held. | |
252 | */ | |
237fead6 MH |
253 | static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) |
254 | { | |
255 | struct inode *inode = page->mapping->host; | |
256 | int end_byte_in_page; | |
237fead6 | 257 | |
9d8b8ce5 MH |
258 | if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index) |
259 | goto out; | |
260 | end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; | |
261 | if (to > end_byte_in_page) | |
262 | end_byte_in_page = to; | |
eebd2aa3 | 263 | zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE); |
237fead6 | 264 | out: |
9d8b8ce5 | 265 | return 0; |
237fead6 MH |
266 | } |
267 | ||
e4465fda | 268 | /** |
807b7ebe | 269 | * ecryptfs_write_begin |
e4465fda | 270 | * @file: The eCryptfs file |
807b7ebe BP |
271 | * @mapping: The eCryptfs object |
272 | * @pos: The file offset at which to start writing | |
273 | * @len: Length of the write | |
274 | * @flags: Various flags | |
275 | * @pagep: Pointer to return the page | |
276 | * @fsdata: Pointer to return fs data (unused) | |
e4465fda MH |
277 | * |
278 | * This function must zero any hole we create | |
279 | * | |
280 | * Returns zero on success; non-zero otherwise | |
281 | */ | |
807b7ebe BP |
282 | static int ecryptfs_write_begin(struct file *file, |
283 | struct address_space *mapping, | |
284 | loff_t pos, unsigned len, unsigned flags, | |
285 | struct page **pagep, void **fsdata) | |
237fead6 | 286 | { |
807b7ebe BP |
287 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
288 | struct page *page; | |
7a3f595c | 289 | loff_t prev_page_end_size; |
e4465fda | 290 | int rc = 0; |
237fead6 | 291 | |
54566b2c | 292 | page = grab_cache_page_write_begin(mapping, index, flags); |
807b7ebe BP |
293 | if (!page) |
294 | return -ENOMEM; | |
295 | *pagep = page; | |
296 | ||
16a72c45 | 297 | if (!PageUptodate(page)) { |
e4465fda MH |
298 | struct ecryptfs_crypt_stat *crypt_stat = |
299 | &ecryptfs_inode_to_private( | |
300 | file->f_path.dentry->d_inode)->crypt_stat; | |
301 | ||
302 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) | |
303 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
304 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe | 305 | page, index, 0, PAGE_CACHE_SIZE, mapping->host); |
e4465fda MH |
306 | if (rc) { |
307 | printk(KERN_ERR "%s: Error attemping to read " | |
308 | "lower page segment; rc = [%d]\n", | |
18d1dbf1 | 309 | __func__, rc); |
e4465fda MH |
310 | ClearPageUptodate(page); |
311 | goto out; | |
312 | } else | |
313 | SetPageUptodate(page); | |
314 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { | |
315 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
316 | rc = ecryptfs_copy_up_encrypted_with_header( | |
317 | page, crypt_stat); | |
318 | if (rc) { | |
319 | printk(KERN_ERR "%s: Error attempting " | |
320 | "to copy the encrypted content " | |
321 | "from the lower file whilst " | |
322 | "inserting the metadata from " | |
323 | "the xattr into the header; rc " | |
18d1dbf1 | 324 | "= [%d]\n", __func__, rc); |
e4465fda MH |
325 | ClearPageUptodate(page); |
326 | goto out; | |
327 | } | |
328 | SetPageUptodate(page); | |
329 | } else { | |
330 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe BP |
331 | page, index, 0, PAGE_CACHE_SIZE, |
332 | mapping->host); | |
e4465fda MH |
333 | if (rc) { |
334 | printk(KERN_ERR "%s: Error reading " | |
335 | "page; rc = [%d]\n", | |
18d1dbf1 | 336 | __func__, rc); |
e4465fda MH |
337 | ClearPageUptodate(page); |
338 | goto out; | |
339 | } | |
340 | SetPageUptodate(page); | |
341 | } | |
342 | } else { | |
343 | rc = ecryptfs_decrypt_page(page); | |
344 | if (rc) { | |
345 | printk(KERN_ERR "%s: Error decrypting page " | |
346 | "at index [%ld]; rc = [%d]\n", | |
18d1dbf1 | 347 | __func__, page->index, rc); |
e4465fda MH |
348 | ClearPageUptodate(page); |
349 | goto out; | |
350 | } | |
16a72c45 | 351 | SetPageUptodate(page); |
e4465fda | 352 | } |
16a72c45 | 353 | } |
807b7ebe | 354 | prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT); |
e4465fda MH |
355 | /* If creating a page or more of holes, zero them out via truncate. |
356 | * Note, this will increase i_size. */ | |
807b7ebe | 357 | if (index != 0) { |
7a3f595c | 358 | if (prev_page_end_size > i_size_read(page->mapping->host)) { |
240e2df5 | 359 | rc = ecryptfs_truncate(file->f_path.dentry, |
7a3f595c | 360 | prev_page_end_size); |
240e2df5 | 361 | if (rc) { |
e4465fda | 362 | printk(KERN_ERR "%s: Error on attempt to " |
240e2df5 | 363 | "truncate to (higher) offset [%lld];" |
18d1dbf1 | 364 | " rc = [%d]\n", __func__, |
e4465fda | 365 | prev_page_end_size, rc); |
240e2df5 MH |
366 | goto out; |
367 | } | |
53a2731f | 368 | } |
7a3f595c | 369 | } |
e4465fda MH |
370 | /* Writing to a new page, and creating a small hole from start |
371 | * of page? Zero it out. */ | |
807b7ebe BP |
372 | if ((i_size_read(mapping->host) == prev_page_end_size) |
373 | && (pos != 0)) | |
eebd2aa3 | 374 | zero_user(page, 0, PAGE_CACHE_SIZE); |
237fead6 MH |
375 | out: |
376 | return rc; | |
377 | } | |
378 | ||
237fead6 MH |
379 | /** |
380 | * ecryptfs_write_inode_size_to_header | |
381 | * | |
382 | * Writes the lower file size to the first 8 bytes of the header. | |
383 | * | |
384 | * Returns zero on success; non-zero on error. | |
385 | */ | |
0216f7f7 | 386 | static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode) |
237fead6 | 387 | { |
0216f7f7 MH |
388 | char *file_size_virt; |
389 | int rc; | |
237fead6 | 390 | |
0216f7f7 MH |
391 | file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL); |
392 | if (!file_size_virt) { | |
393 | rc = -ENOMEM; | |
ae73fc09 MH |
394 | goto out; |
395 | } | |
0a688ad7 | 396 | put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt); |
0216f7f7 MH |
397 | rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0, |
398 | sizeof(u64)); | |
399 | kfree(file_size_virt); | |
96a7b9c2 | 400 | if (rc < 0) |
0216f7f7 | 401 | printk(KERN_ERR "%s: Error writing file size to header; " |
18d1dbf1 | 402 | "rc = [%d]\n", __func__, rc); |
96a7b9c2 TH |
403 | else |
404 | rc = 0; | |
237fead6 MH |
405 | out: |
406 | return rc; | |
407 | } | |
408 | ||
0216f7f7 MH |
409 | struct kmem_cache *ecryptfs_xattr_cache; |
410 | ||
411 | static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) | |
dd2a3b7a MH |
412 | { |
413 | ssize_t size; | |
414 | void *xattr_virt; | |
0216f7f7 MH |
415 | struct dentry *lower_dentry = |
416 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
417 | struct inode *lower_inode = lower_dentry->d_inode; | |
dd2a3b7a MH |
418 | int rc; |
419 | ||
0216f7f7 MH |
420 | if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { |
421 | printk(KERN_WARNING | |
422 | "No support for setting xattr in lower filesystem\n"); | |
423 | rc = -ENOSYS; | |
424 | goto out; | |
425 | } | |
dd2a3b7a MH |
426 | xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); |
427 | if (!xattr_virt) { | |
428 | printk(KERN_ERR "Out of memory whilst attempting to write " | |
429 | "inode size to xattr\n"); | |
430 | rc = -ENOMEM; | |
431 | goto out; | |
432 | } | |
0216f7f7 MH |
433 | mutex_lock(&lower_inode->i_mutex); |
434 | size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME, | |
435 | xattr_virt, PAGE_CACHE_SIZE); | |
dd2a3b7a MH |
436 | if (size < 0) |
437 | size = 8; | |
0a688ad7 | 438 | put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); |
0216f7f7 MH |
439 | rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME, |
440 | xattr_virt, size, 0); | |
441 | mutex_unlock(&lower_inode->i_mutex); | |
dd2a3b7a MH |
442 | if (rc) |
443 | printk(KERN_ERR "Error whilst attempting to write inode size " | |
444 | "to lower file xattr; rc = [%d]\n", rc); | |
445 | kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); | |
446 | out: | |
447 | return rc; | |
448 | } | |
449 | ||
0216f7f7 | 450 | int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) |
dd2a3b7a MH |
451 | { |
452 | struct ecryptfs_crypt_stat *crypt_stat; | |
453 | ||
0216f7f7 | 454 | crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
13a791b4 | 455 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
dd2a3b7a | 456 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
0216f7f7 | 457 | return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode); |
dd2a3b7a | 458 | else |
0216f7f7 | 459 | return ecryptfs_write_inode_size_to_header(ecryptfs_inode); |
dd2a3b7a MH |
460 | } |
461 | ||
237fead6 | 462 | /** |
807b7ebe | 463 | * ecryptfs_write_end |
237fead6 | 464 | * @file: The eCryptfs file object |
807b7ebe BP |
465 | * @mapping: The eCryptfs object |
466 | * @pos: The file position | |
467 | * @len: The length of the data (unused) | |
468 | * @copied: The amount of data copied | |
237fead6 | 469 | * @page: The eCryptfs page |
807b7ebe | 470 | * @fsdata: The fsdata (unused) |
237fead6 MH |
471 | * |
472 | * This is where we encrypt the data and pass the encrypted data to | |
473 | * the lower filesystem. In OpenPGP-compatible mode, we operate on | |
474 | * entire underlying packets. | |
475 | */ | |
807b7ebe BP |
476 | static int ecryptfs_write_end(struct file *file, |
477 | struct address_space *mapping, | |
478 | loff_t pos, unsigned len, unsigned copied, | |
479 | struct page *page, void *fsdata) | |
237fead6 | 480 | { |
807b7ebe BP |
481 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
482 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
483 | unsigned to = from + copied; | |
484 | struct inode *ecryptfs_inode = mapping->host; | |
bf12be1c MH |
485 | struct ecryptfs_crypt_stat *crypt_stat = |
486 | &ecryptfs_inode_to_private(file->f_path.dentry->d_inode)->crypt_stat; | |
237fead6 MH |
487 | int rc; |
488 | ||
e2bd99ec | 489 | if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { |
237fead6 MH |
490 | ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " |
491 | "crypt_stat at memory location [%p]\n", crypt_stat); | |
e2bd99ec | 492 | crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); |
237fead6 MH |
493 | } else |
494 | ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); | |
495 | ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" | |
807b7ebe | 496 | "(page w/ index = [0x%.16x], to = [%d])\n", index, to); |
13a791b4 TH |
497 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
498 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0, | |
499 | to); | |
500 | if (!rc) { | |
501 | rc = copied; | |
502 | fsstack_copy_inode_size(ecryptfs_inode, | |
503 | ecryptfs_inode_to_lower(ecryptfs_inode)); | |
504 | } | |
505 | goto out; | |
506 | } | |
bf12be1c | 507 | /* Fills in zeros if 'to' goes beyond inode size */ |
237fead6 MH |
508 | rc = fill_zeros_to_end_of_page(page, to); |
509 | if (rc) { | |
510 | ecryptfs_printk(KERN_WARNING, "Error attempting to fill " | |
807b7ebe | 511 | "zeros in page with index = [0x%.16x]\n", index); |
237fead6 MH |
512 | goto out; |
513 | } | |
0216f7f7 | 514 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
515 | if (rc) { |
516 | ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " | |
807b7ebe | 517 | "index [0x%.16x])\n", index); |
237fead6 MH |
518 | goto out; |
519 | } | |
807b7ebe BP |
520 | if (pos + copied > i_size_read(ecryptfs_inode)) { |
521 | i_size_write(ecryptfs_inode, pos + copied); | |
237fead6 | 522 | ecryptfs_printk(KERN_DEBUG, "Expanded file size to " |
bf12be1c | 523 | "[0x%.16x]\n", i_size_read(ecryptfs_inode)); |
237fead6 | 524 | } |
bf12be1c | 525 | rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); |
dd2a3b7a MH |
526 | if (rc) |
527 | printk(KERN_ERR "Error writing inode size to metadata; " | |
528 | "rc = [%d]\n", rc); | |
807b7ebe BP |
529 | else |
530 | rc = copied; | |
237fead6 | 531 | out: |
807b7ebe BP |
532 | unlock_page(page); |
533 | page_cache_release(page); | |
237fead6 MH |
534 | return rc; |
535 | } | |
536 | ||
237fead6 MH |
537 | static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) |
538 | { | |
539 | int rc = 0; | |
540 | struct inode *inode; | |
541 | struct inode *lower_inode; | |
542 | ||
543 | inode = (struct inode *)mapping->host; | |
544 | lower_inode = ecryptfs_inode_to_lower(inode); | |
545 | if (lower_inode->i_mapping->a_ops->bmap) | |
546 | rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, | |
547 | block); | |
548 | return rc; | |
549 | } | |
550 | ||
7f09410b | 551 | const struct address_space_operations ecryptfs_aops = { |
237fead6 MH |
552 | .writepage = ecryptfs_writepage, |
553 | .readpage = ecryptfs_readpage, | |
807b7ebe BP |
554 | .write_begin = ecryptfs_write_begin, |
555 | .write_end = ecryptfs_write_end, | |
237fead6 | 556 | .bmap = ecryptfs_bmap, |
237fead6 | 557 | }; |