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> | |
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 | */ | |
02bd9799 | 47 | struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index) |
237fead6 | 48 | { |
02bd9799 | 49 | struct page *page = read_mapping_page(inode->i_mapping, index, NULL); |
16a72c45 MH |
50 | if (!IS_ERR(page)) |
51 | lock_page(page); | |
52 | return page; | |
237fead6 MH |
53 | } |
54 | ||
237fead6 MH |
55 | /** |
56 | * ecryptfs_writepage | |
57 | * @page: Page that is locked before this call is made | |
58 | * | |
59 | * Returns zero on success; non-zero otherwise | |
60 | */ | |
61 | static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) | |
62 | { | |
237fead6 MH |
63 | int rc; |
64 | ||
0216f7f7 | 65 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
66 | if (rc) { |
67 | ecryptfs_printk(KERN_WARNING, "Error encrypting " | |
888d57bb | 68 | "page (upper index [0x%.16lx])\n", page->index); |
237fead6 MH |
69 | ClearPageUptodate(page); |
70 | goto out; | |
71 | } | |
72 | SetPageUptodate(page); | |
73 | unlock_page(page); | |
74 | out: | |
75 | return rc; | |
76 | } | |
77 | ||
f4e60e6b TH |
78 | static void strip_xattr_flag(char *page_virt, |
79 | struct ecryptfs_crypt_stat *crypt_stat) | |
80 | { | |
81 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
82 | size_t written; | |
83 | ||
84 | crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR; | |
85 | ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat, | |
86 | &written); | |
87 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
88 | } | |
89 | } | |
90 | ||
e77a56dd MH |
91 | /** |
92 | * Header Extent: | |
93 | * Octets 0-7: Unencrypted file size (big-endian) | |
94 | * Octets 8-15: eCryptfs special marker | |
95 | * Octets 16-19: Flags | |
96 | * Octet 16: File format version number (between 0 and 255) | |
97 | * Octets 17-18: Reserved | |
98 | * Octet 19: Bit 1 (lsb): Reserved | |
99 | * Bit 2: Encrypted? | |
100 | * Bits 3-8: Reserved | |
101 | * Octets 20-23: Header extent size (big-endian) | |
102 | * Octets 24-25: Number of header extents at front of file | |
103 | * (big-endian) | |
104 | * Octet 26: Begin RFC 2440 authentication token packet set | |
105 | */ | |
237fead6 | 106 | |
bf12be1c MH |
107 | /** |
108 | * ecryptfs_copy_up_encrypted_with_header | |
109 | * @page: Sort of a ``virtual'' representation of the encrypted lower | |
110 | * file. The actual lower file does not have the metadata in | |
111 | * the header. This is locked. | |
112 | * @crypt_stat: The eCryptfs inode's cryptographic context | |
113 | * | |
114 | * The ``view'' is the version of the file that userspace winds up | |
115 | * seeing, with the header information inserted. | |
116 | */ | |
117 | static int | |
118 | ecryptfs_copy_up_encrypted_with_header(struct page *page, | |
119 | struct ecryptfs_crypt_stat *crypt_stat) | |
120 | { | |
121 | loff_t extent_num_in_page = 0; | |
122 | loff_t num_extents_per_page = (PAGE_CACHE_SIZE | |
123 | / crypt_stat->extent_size); | |
124 | int rc = 0; | |
125 | ||
126 | while (extent_num_in_page < num_extents_per_page) { | |
d6a13c17 MH |
127 | loff_t view_extent_num = ((((loff_t)page->index) |
128 | * num_extents_per_page) | |
bf12be1c | 129 | + extent_num_in_page); |
cc11beff | 130 | size_t num_header_extents_at_front = |
fa3ef1cb | 131 | (crypt_stat->metadata_size / crypt_stat->extent_size); |
bf12be1c | 132 | |
cc11beff | 133 | if (view_extent_num < num_header_extents_at_front) { |
bf12be1c MH |
134 | /* This is a header extent */ |
135 | char *page_virt; | |
136 | ||
137 | page_virt = kmap_atomic(page, KM_USER0); | |
138 | memset(page_virt, 0, PAGE_CACHE_SIZE); | |
139 | /* TODO: Support more than one header extent */ | |
140 | if (view_extent_num == 0) { | |
157f1071 TH |
141 | size_t written; |
142 | ||
bf12be1c MH |
143 | rc = ecryptfs_read_xattr_region( |
144 | page_virt, page->mapping->host); | |
f4e60e6b | 145 | strip_xattr_flag(page_virt + 16, crypt_stat); |
157f1071 TH |
146 | ecryptfs_write_header_metadata(page_virt + 20, |
147 | crypt_stat, | |
148 | &written); | |
bf12be1c MH |
149 | } |
150 | kunmap_atomic(page_virt, KM_USER0); | |
151 | flush_dcache_page(page); | |
152 | if (rc) { | |
bf12be1c | 153 | printk(KERN_ERR "%s: Error reading xattr " |
18d1dbf1 | 154 | "region; rc = [%d]\n", __func__, rc); |
bf12be1c MH |
155 | goto out; |
156 | } | |
bf12be1c MH |
157 | } else { |
158 | /* This is an encrypted data extent */ | |
159 | loff_t lower_offset = | |
cc11beff | 160 | ((view_extent_num * crypt_stat->extent_size) |
fa3ef1cb | 161 | - crypt_stat->metadata_size); |
bf12be1c MH |
162 | |
163 | rc = ecryptfs_read_lower_page_segment( | |
164 | page, (lower_offset >> PAGE_CACHE_SHIFT), | |
165 | (lower_offset & ~PAGE_CACHE_MASK), | |
166 | crypt_stat->extent_size, page->mapping->host); | |
167 | if (rc) { | |
168 | printk(KERN_ERR "%s: Error attempting to read " | |
169 | "extent at offset [%lld] in the lower " | |
18d1dbf1 | 170 | "file; rc = [%d]\n", __func__, |
bf12be1c MH |
171 | lower_offset, rc); |
172 | goto out; | |
173 | } | |
174 | } | |
175 | extent_num_in_page++; | |
176 | } | |
177 | out: | |
178 | return rc; | |
179 | } | |
180 | ||
237fead6 MH |
181 | /** |
182 | * ecryptfs_readpage | |
bf12be1c MH |
183 | * @file: An eCryptfs file |
184 | * @page: Page from eCryptfs inode mapping into which to stick the read data | |
237fead6 MH |
185 | * |
186 | * Read in a page, decrypting if necessary. | |
187 | * | |
188 | * Returns zero on success; non-zero on error. | |
189 | */ | |
190 | static int ecryptfs_readpage(struct file *file, struct page *page) | |
191 | { | |
bf12be1c | 192 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 193 | &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat; |
237fead6 | 194 | int rc = 0; |
237fead6 | 195 | |
237fead6 | 196 | if (!crypt_stat |
e2bd99ec MH |
197 | || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED) |
198 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
237fead6 MH |
199 | ecryptfs_printk(KERN_DEBUG, |
200 | "Passing through unencrypted page\n"); | |
bf12be1c MH |
201 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
202 | PAGE_CACHE_SIZE, | |
203 | page->mapping->host); | |
e77a56dd MH |
204 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
205 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
bf12be1c MH |
206 | rc = ecryptfs_copy_up_encrypted_with_header(page, |
207 | crypt_stat); | |
208 | if (rc) { | |
209 | printk(KERN_ERR "%s: Error attempting to copy " | |
210 | "the encrypted content from the lower " | |
211 | "file whilst inserting the metadata " | |
212 | "from the xattr into the header; rc = " | |
18d1dbf1 | 213 | "[%d]\n", __func__, rc); |
bf12be1c | 214 | goto out; |
e77a56dd | 215 | } |
bf12be1c | 216 | |
e77a56dd | 217 | } else { |
bf12be1c MH |
218 | rc = ecryptfs_read_lower_page_segment( |
219 | page, page->index, 0, PAGE_CACHE_SIZE, | |
220 | page->mapping->host); | |
e77a56dd MH |
221 | if (rc) { |
222 | printk(KERN_ERR "Error reading page; rc = " | |
223 | "[%d]\n", rc); | |
224 | goto out; | |
225 | } | |
226 | } | |
237fead6 | 227 | } else { |
0216f7f7 | 228 | rc = ecryptfs_decrypt_page(page); |
237fead6 | 229 | if (rc) { |
237fead6 MH |
230 | ecryptfs_printk(KERN_ERR, "Error decrypting page; " |
231 | "rc = [%d]\n", rc); | |
232 | goto out; | |
233 | } | |
234 | } | |
237fead6 | 235 | out: |
16a72c45 MH |
236 | if (rc) |
237 | ClearPageUptodate(page); | |
238 | else | |
239 | SetPageUptodate(page); | |
888d57bb | 240 | ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n", |
237fead6 MH |
241 | page->index); |
242 | unlock_page(page); | |
243 | return rc; | |
244 | } | |
245 | ||
dd2a3b7a MH |
246 | /** |
247 | * Called with lower inode mutex held. | |
248 | */ | |
237fead6 MH |
249 | static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) |
250 | { | |
251 | struct inode *inode = page->mapping->host; | |
252 | int end_byte_in_page; | |
237fead6 | 253 | |
9d8b8ce5 MH |
254 | if ((i_size_read(inode) / PAGE_CACHE_SIZE) != page->index) |
255 | goto out; | |
256 | end_byte_in_page = i_size_read(inode) % PAGE_CACHE_SIZE; | |
257 | if (to > end_byte_in_page) | |
258 | end_byte_in_page = to; | |
eebd2aa3 | 259 | zero_user_segment(page, end_byte_in_page, PAGE_CACHE_SIZE); |
237fead6 | 260 | out: |
9d8b8ce5 | 261 | return 0; |
237fead6 MH |
262 | } |
263 | ||
e4465fda | 264 | /** |
807b7ebe | 265 | * ecryptfs_write_begin |
e4465fda | 266 | * @file: The eCryptfs file |
807b7ebe BP |
267 | * @mapping: The eCryptfs object |
268 | * @pos: The file offset at which to start writing | |
269 | * @len: Length of the write | |
270 | * @flags: Various flags | |
271 | * @pagep: Pointer to return the page | |
272 | * @fsdata: Pointer to return fs data (unused) | |
e4465fda MH |
273 | * |
274 | * This function must zero any hole we create | |
275 | * | |
276 | * Returns zero on success; non-zero otherwise | |
277 | */ | |
807b7ebe BP |
278 | static int ecryptfs_write_begin(struct file *file, |
279 | struct address_space *mapping, | |
280 | loff_t pos, unsigned len, unsigned flags, | |
281 | struct page **pagep, void **fsdata) | |
237fead6 | 282 | { |
807b7ebe BP |
283 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
284 | struct page *page; | |
7a3f595c | 285 | loff_t prev_page_end_size; |
e4465fda | 286 | int rc = 0; |
237fead6 | 287 | |
54566b2c | 288 | page = grab_cache_page_write_begin(mapping, index, flags); |
807b7ebe BP |
289 | if (!page) |
290 | return -ENOMEM; | |
291 | *pagep = page; | |
292 | ||
24562486 | 293 | prev_page_end_size = ((loff_t)index << PAGE_CACHE_SHIFT); |
16a72c45 | 294 | if (!PageUptodate(page)) { |
e4465fda | 295 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 296 | &ecryptfs_inode_to_private(mapping->host)->crypt_stat; |
e4465fda MH |
297 | |
298 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED) | |
299 | || (crypt_stat->flags & ECRYPTFS_NEW_FILE)) { | |
300 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe | 301 | page, index, 0, PAGE_CACHE_SIZE, mapping->host); |
e4465fda MH |
302 | if (rc) { |
303 | printk(KERN_ERR "%s: Error attemping to read " | |
304 | "lower page segment; rc = [%d]\n", | |
18d1dbf1 | 305 | __func__, rc); |
e4465fda MH |
306 | ClearPageUptodate(page); |
307 | goto out; | |
308 | } else | |
309 | SetPageUptodate(page); | |
310 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { | |
311 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
312 | rc = ecryptfs_copy_up_encrypted_with_header( | |
313 | page, crypt_stat); | |
314 | if (rc) { | |
315 | printk(KERN_ERR "%s: Error attempting " | |
316 | "to copy the encrypted content " | |
317 | "from the lower file whilst " | |
318 | "inserting the metadata from " | |
319 | "the xattr into the header; rc " | |
18d1dbf1 | 320 | "= [%d]\n", __func__, rc); |
e4465fda MH |
321 | ClearPageUptodate(page); |
322 | goto out; | |
323 | } | |
324 | SetPageUptodate(page); | |
325 | } else { | |
326 | rc = ecryptfs_read_lower_page_segment( | |
807b7ebe BP |
327 | page, index, 0, PAGE_CACHE_SIZE, |
328 | mapping->host); | |
e4465fda MH |
329 | if (rc) { |
330 | printk(KERN_ERR "%s: Error reading " | |
331 | "page; rc = [%d]\n", | |
18d1dbf1 | 332 | __func__, rc); |
e4465fda MH |
333 | ClearPageUptodate(page); |
334 | goto out; | |
335 | } | |
336 | SetPageUptodate(page); | |
337 | } | |
338 | } else { | |
24562486 FS |
339 | if (prev_page_end_size |
340 | >= i_size_read(page->mapping->host)) { | |
341 | zero_user(page, 0, PAGE_CACHE_SIZE); | |
342 | } else { | |
343 | rc = ecryptfs_decrypt_page(page); | |
344 | if (rc) { | |
345 | printk(KERN_ERR "%s: Error decrypting " | |
346 | "page at index [%ld]; " | |
347 | "rc = [%d]\n", | |
348 | __func__, page->index, rc); | |
349 | ClearPageUptodate(page); | |
350 | goto out; | |
351 | } | |
e4465fda | 352 | } |
16a72c45 | 353 | SetPageUptodate(page); |
e4465fda | 354 | } |
16a72c45 | 355 | } |
e4465fda MH |
356 | /* If creating a page or more of holes, zero them out via truncate. |
357 | * Note, this will increase i_size. */ | |
807b7ebe | 358 | if (index != 0) { |
7a3f595c | 359 | if (prev_page_end_size > i_size_read(page->mapping->host)) { |
240e2df5 | 360 | rc = ecryptfs_truncate(file->f_path.dentry, |
7a3f595c | 361 | prev_page_end_size); |
240e2df5 | 362 | if (rc) { |
e4465fda | 363 | printk(KERN_ERR "%s: Error on attempt to " |
240e2df5 | 364 | "truncate to (higher) offset [%lld];" |
18d1dbf1 | 365 | " rc = [%d]\n", __func__, |
e4465fda | 366 | prev_page_end_size, rc); |
240e2df5 MH |
367 | goto out; |
368 | } | |
53a2731f | 369 | } |
7a3f595c | 370 | } |
e4465fda MH |
371 | /* Writing to a new page, and creating a small hole from start |
372 | * of page? Zero it out. */ | |
807b7ebe BP |
373 | if ((i_size_read(mapping->host) == prev_page_end_size) |
374 | && (pos != 0)) | |
eebd2aa3 | 375 | zero_user(page, 0, PAGE_CACHE_SIZE); |
237fead6 MH |
376 | out: |
377 | return rc; | |
378 | } | |
379 | ||
237fead6 MH |
380 | /** |
381 | * ecryptfs_write_inode_size_to_header | |
382 | * | |
383 | * Writes the lower file size to the first 8 bytes of the header. | |
384 | * | |
385 | * Returns zero on success; non-zero on error. | |
386 | */ | |
0216f7f7 | 387 | static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode) |
237fead6 | 388 | { |
0216f7f7 MH |
389 | char *file_size_virt; |
390 | int rc; | |
237fead6 | 391 | |
0216f7f7 MH |
392 | file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL); |
393 | if (!file_size_virt) { | |
394 | rc = -ENOMEM; | |
ae73fc09 MH |
395 | goto out; |
396 | } | |
0a688ad7 | 397 | put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt); |
0216f7f7 MH |
398 | rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0, |
399 | sizeof(u64)); | |
400 | kfree(file_size_virt); | |
96a7b9c2 | 401 | if (rc < 0) |
0216f7f7 | 402 | printk(KERN_ERR "%s: Error writing file size to header; " |
18d1dbf1 | 403 | "rc = [%d]\n", __func__, rc); |
96a7b9c2 TH |
404 | else |
405 | rc = 0; | |
237fead6 MH |
406 | out: |
407 | return rc; | |
408 | } | |
409 | ||
0216f7f7 MH |
410 | struct kmem_cache *ecryptfs_xattr_cache; |
411 | ||
412 | static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) | |
dd2a3b7a MH |
413 | { |
414 | ssize_t size; | |
415 | void *xattr_virt; | |
0216f7f7 MH |
416 | struct dentry *lower_dentry = |
417 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_dentry; | |
418 | struct inode *lower_inode = lower_dentry->d_inode; | |
dd2a3b7a MH |
419 | int rc; |
420 | ||
0216f7f7 MH |
421 | if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { |
422 | printk(KERN_WARNING | |
423 | "No support for setting xattr in lower filesystem\n"); | |
424 | rc = -ENOSYS; | |
425 | goto out; | |
426 | } | |
dd2a3b7a MH |
427 | xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); |
428 | if (!xattr_virt) { | |
429 | printk(KERN_ERR "Out of memory whilst attempting to write " | |
430 | "inode size to xattr\n"); | |
431 | rc = -ENOMEM; | |
432 | goto out; | |
433 | } | |
0216f7f7 MH |
434 | mutex_lock(&lower_inode->i_mutex); |
435 | size = lower_inode->i_op->getxattr(lower_dentry, ECRYPTFS_XATTR_NAME, | |
436 | xattr_virt, PAGE_CACHE_SIZE); | |
dd2a3b7a MH |
437 | if (size < 0) |
438 | size = 8; | |
0a688ad7 | 439 | put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); |
0216f7f7 MH |
440 | rc = lower_inode->i_op->setxattr(lower_dentry, ECRYPTFS_XATTR_NAME, |
441 | xattr_virt, size, 0); | |
442 | mutex_unlock(&lower_inode->i_mutex); | |
dd2a3b7a MH |
443 | if (rc) |
444 | printk(KERN_ERR "Error whilst attempting to write inode size " | |
445 | "to lower file xattr; rc = [%d]\n", rc); | |
446 | kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); | |
447 | out: | |
448 | return rc; | |
449 | } | |
450 | ||
0216f7f7 | 451 | int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) |
dd2a3b7a MH |
452 | { |
453 | struct ecryptfs_crypt_stat *crypt_stat; | |
454 | ||
0216f7f7 | 455 | crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
13a791b4 | 456 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
dd2a3b7a | 457 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
0216f7f7 | 458 | return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode); |
dd2a3b7a | 459 | else |
0216f7f7 | 460 | return ecryptfs_write_inode_size_to_header(ecryptfs_inode); |
dd2a3b7a MH |
461 | } |
462 | ||
237fead6 | 463 | /** |
807b7ebe | 464 | * ecryptfs_write_end |
237fead6 | 465 | * @file: The eCryptfs file object |
807b7ebe BP |
466 | * @mapping: The eCryptfs object |
467 | * @pos: The file position | |
468 | * @len: The length of the data (unused) | |
469 | * @copied: The amount of data copied | |
237fead6 | 470 | * @page: The eCryptfs page |
807b7ebe | 471 | * @fsdata: The fsdata (unused) |
237fead6 MH |
472 | * |
473 | * This is where we encrypt the data and pass the encrypted data to | |
474 | * the lower filesystem. In OpenPGP-compatible mode, we operate on | |
475 | * entire underlying packets. | |
476 | */ | |
807b7ebe BP |
477 | static int ecryptfs_write_end(struct file *file, |
478 | struct address_space *mapping, | |
479 | loff_t pos, unsigned len, unsigned copied, | |
480 | struct page *page, void *fsdata) | |
237fead6 | 481 | { |
807b7ebe BP |
482 | pgoff_t index = pos >> PAGE_CACHE_SHIFT; |
483 | unsigned from = pos & (PAGE_CACHE_SIZE - 1); | |
484 | unsigned to = from + copied; | |
485 | struct inode *ecryptfs_inode = mapping->host; | |
bf12be1c | 486 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 487 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
237fead6 MH |
488 | int rc; |
489 | ||
e2bd99ec | 490 | if (crypt_stat->flags & ECRYPTFS_NEW_FILE) { |
237fead6 MH |
491 | ecryptfs_printk(KERN_DEBUG, "ECRYPTFS_NEW_FILE flag set in " |
492 | "crypt_stat at memory location [%p]\n", crypt_stat); | |
e2bd99ec | 493 | crypt_stat->flags &= ~(ECRYPTFS_NEW_FILE); |
237fead6 MH |
494 | } else |
495 | ecryptfs_printk(KERN_DEBUG, "Not a new file\n"); | |
496 | ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" | |
888d57bb | 497 | "(page w/ index = [0x%.16lx], to = [%d])\n", index, to); |
13a791b4 TH |
498 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
499 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0, | |
500 | to); | |
501 | if (!rc) { | |
502 | rc = copied; | |
503 | fsstack_copy_inode_size(ecryptfs_inode, | |
504 | ecryptfs_inode_to_lower(ecryptfs_inode)); | |
505 | } | |
506 | goto out; | |
507 | } | |
bf12be1c | 508 | /* Fills in zeros if 'to' goes beyond inode size */ |
237fead6 MH |
509 | rc = fill_zeros_to_end_of_page(page, to); |
510 | if (rc) { | |
511 | ecryptfs_printk(KERN_WARNING, "Error attempting to fill " | |
888d57bb | 512 | "zeros in page with index = [0x%.16lx]\n", index); |
237fead6 MH |
513 | goto out; |
514 | } | |
0216f7f7 | 515 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
516 | if (rc) { |
517 | ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " | |
888d57bb | 518 | "index [0x%.16lx])\n", index); |
237fead6 MH |
519 | goto out; |
520 | } | |
807b7ebe BP |
521 | if (pos + copied > i_size_read(ecryptfs_inode)) { |
522 | i_size_write(ecryptfs_inode, pos + copied); | |
237fead6 | 523 | ecryptfs_printk(KERN_DEBUG, "Expanded file size to " |
888d57bb JP |
524 | "[0x%.16llx]\n", |
525 | (unsigned long long)i_size_read(ecryptfs_inode)); | |
237fead6 | 526 | } |
bf12be1c | 527 | rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); |
dd2a3b7a MH |
528 | if (rc) |
529 | printk(KERN_ERR "Error writing inode size to metadata; " | |
530 | "rc = [%d]\n", rc); | |
807b7ebe BP |
531 | else |
532 | rc = copied; | |
237fead6 | 533 | out: |
807b7ebe BP |
534 | unlock_page(page); |
535 | page_cache_release(page); | |
237fead6 MH |
536 | return rc; |
537 | } | |
538 | ||
237fead6 MH |
539 | static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) |
540 | { | |
541 | int rc = 0; | |
542 | struct inode *inode; | |
543 | struct inode *lower_inode; | |
544 | ||
545 | inode = (struct inode *)mapping->host; | |
546 | lower_inode = ecryptfs_inode_to_lower(inode); | |
547 | if (lower_inode->i_mapping->a_ops->bmap) | |
548 | rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, | |
549 | block); | |
550 | return rc; | |
551 | } | |
552 | ||
7f09410b | 553 | const struct address_space_operations ecryptfs_aops = { |
237fead6 MH |
554 | .writepage = ecryptfs_writepage, |
555 | .readpage = ecryptfs_readpage, | |
807b7ebe BP |
556 | .write_begin = ecryptfs_write_begin, |
557 | .write_end = ecryptfs_write_end, | |
237fead6 | 558 | .bmap = ecryptfs_bmap, |
237fead6 | 559 | }; |