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> | |
237fead6 | 33 | #include <linux/scatterlist.h> |
5a0e3ad6 | 34 | #include <linux/slab.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 | */ | |
02bd9799 | 46 | struct page *ecryptfs_get_locked_page(struct inode *inode, loff_t index) |
237fead6 | 47 | { |
02bd9799 | 48 | struct page *page = read_mapping_page(inode->i_mapping, index, NULL); |
16a72c45 MH |
49 | if (!IS_ERR(page)) |
50 | lock_page(page); | |
51 | return page; | |
237fead6 MH |
52 | } |
53 | ||
237fead6 MH |
54 | /** |
55 | * ecryptfs_writepage | |
56 | * @page: Page that is locked before this call is made | |
57 | * | |
58 | * Returns zero on success; non-zero otherwise | |
1589cb1a LW |
59 | * |
60 | * This is where we encrypt the data and pass the encrypted data to | |
61 | * the lower filesystem. In OpenPGP-compatible mode, we operate on | |
62 | * entire underlying packets. | |
237fead6 MH |
63 | */ |
64 | static int ecryptfs_writepage(struct page *page, struct writeback_control *wbc) | |
65 | { | |
237fead6 MH |
66 | int rc; |
67 | ||
0216f7f7 | 68 | rc = ecryptfs_encrypt_page(page); |
237fead6 MH |
69 | if (rc) { |
70 | ecryptfs_printk(KERN_WARNING, "Error encrypting " | |
888d57bb | 71 | "page (upper index [0x%.16lx])\n", page->index); |
237fead6 MH |
72 | ClearPageUptodate(page); |
73 | goto out; | |
74 | } | |
75 | SetPageUptodate(page); | |
237fead6 | 76 | out: |
57db4e8d | 77 | unlock_page(page); |
237fead6 MH |
78 | return rc; |
79 | } | |
80 | ||
f4e60e6b TH |
81 | static void strip_xattr_flag(char *page_virt, |
82 | struct ecryptfs_crypt_stat *crypt_stat) | |
83 | { | |
84 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
85 | size_t written; | |
86 | ||
87 | crypt_stat->flags &= ~ECRYPTFS_METADATA_IN_XATTR; | |
88 | ecryptfs_write_crypt_stat_flags(page_virt, crypt_stat, | |
89 | &written); | |
90 | crypt_stat->flags |= ECRYPTFS_METADATA_IN_XATTR; | |
91 | } | |
92 | } | |
93 | ||
e77a56dd MH |
94 | /** |
95 | * Header Extent: | |
96 | * Octets 0-7: Unencrypted file size (big-endian) | |
97 | * Octets 8-15: eCryptfs special marker | |
98 | * Octets 16-19: Flags | |
99 | * Octet 16: File format version number (between 0 and 255) | |
100 | * Octets 17-18: Reserved | |
101 | * Octet 19: Bit 1 (lsb): Reserved | |
102 | * Bit 2: Encrypted? | |
103 | * Bits 3-8: Reserved | |
104 | * Octets 20-23: Header extent size (big-endian) | |
105 | * Octets 24-25: Number of header extents at front of file | |
106 | * (big-endian) | |
107 | * Octet 26: Begin RFC 2440 authentication token packet set | |
108 | */ | |
237fead6 | 109 | |
bf12be1c MH |
110 | /** |
111 | * ecryptfs_copy_up_encrypted_with_header | |
112 | * @page: Sort of a ``virtual'' representation of the encrypted lower | |
113 | * file. The actual lower file does not have the metadata in | |
114 | * the header. This is locked. | |
115 | * @crypt_stat: The eCryptfs inode's cryptographic context | |
116 | * | |
117 | * The ``view'' is the version of the file that userspace winds up | |
118 | * seeing, with the header information inserted. | |
119 | */ | |
120 | static int | |
121 | ecryptfs_copy_up_encrypted_with_header(struct page *page, | |
122 | struct ecryptfs_crypt_stat *crypt_stat) | |
123 | { | |
124 | loff_t extent_num_in_page = 0; | |
09cbfeaf | 125 | loff_t num_extents_per_page = (PAGE_SIZE |
bf12be1c MH |
126 | / crypt_stat->extent_size); |
127 | int rc = 0; | |
128 | ||
129 | while (extent_num_in_page < num_extents_per_page) { | |
d6a13c17 MH |
130 | loff_t view_extent_num = ((((loff_t)page->index) |
131 | * num_extents_per_page) | |
bf12be1c | 132 | + extent_num_in_page); |
cc11beff | 133 | size_t num_header_extents_at_front = |
fa3ef1cb | 134 | (crypt_stat->metadata_size / crypt_stat->extent_size); |
bf12be1c | 135 | |
cc11beff | 136 | if (view_extent_num < num_header_extents_at_front) { |
bf12be1c MH |
137 | /* This is a header extent */ |
138 | char *page_virt; | |
139 | ||
465c9343 | 140 | page_virt = kmap_atomic(page); |
09cbfeaf | 141 | memset(page_virt, 0, PAGE_SIZE); |
bf12be1c MH |
142 | /* TODO: Support more than one header extent */ |
143 | if (view_extent_num == 0) { | |
157f1071 TH |
144 | size_t written; |
145 | ||
bf12be1c MH |
146 | rc = ecryptfs_read_xattr_region( |
147 | page_virt, page->mapping->host); | |
f4e60e6b | 148 | strip_xattr_flag(page_virt + 16, crypt_stat); |
157f1071 TH |
149 | ecryptfs_write_header_metadata(page_virt + 20, |
150 | crypt_stat, | |
151 | &written); | |
bf12be1c | 152 | } |
465c9343 | 153 | kunmap_atomic(page_virt); |
bf12be1c MH |
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 | 163 | ((view_extent_num * crypt_stat->extent_size) |
fa3ef1cb | 164 | - crypt_stat->metadata_size); |
bf12be1c MH |
165 | |
166 | rc = ecryptfs_read_lower_page_segment( | |
09cbfeaf KS |
167 | page, (lower_offset >> PAGE_SHIFT), |
168 | (lower_offset & ~PAGE_MASK), | |
bf12be1c MH |
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 | 195 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 196 | &ecryptfs_inode_to_private(page->mapping->host)->crypt_stat; |
237fead6 | 197 | int rc = 0; |
237fead6 | 198 | |
fed8859b | 199 | if (!crypt_stat || !(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
bf12be1c | 200 | rc = ecryptfs_read_lower_page_segment(page, page->index, 0, |
09cbfeaf | 201 | PAGE_SIZE, |
bf12be1c | 202 | page->mapping->host); |
e77a56dd MH |
203 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { |
204 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
bf12be1c MH |
205 | rc = ecryptfs_copy_up_encrypted_with_header(page, |
206 | crypt_stat); | |
207 | if (rc) { | |
208 | printk(KERN_ERR "%s: Error attempting to copy " | |
209 | "the encrypted content from the lower " | |
210 | "file whilst inserting the metadata " | |
211 | "from the xattr into the header; rc = " | |
18d1dbf1 | 212 | "[%d]\n", __func__, rc); |
bf12be1c | 213 | goto out; |
e77a56dd | 214 | } |
bf12be1c | 215 | |
e77a56dd | 216 | } else { |
bf12be1c | 217 | rc = ecryptfs_read_lower_page_segment( |
09cbfeaf | 218 | page, page->index, 0, PAGE_SIZE, |
bf12be1c | 219 | page->mapping->host); |
e77a56dd MH |
220 | if (rc) { |
221 | printk(KERN_ERR "Error reading page; rc = " | |
222 | "[%d]\n", rc); | |
223 | goto out; | |
224 | } | |
225 | } | |
237fead6 | 226 | } else { |
0216f7f7 | 227 | rc = ecryptfs_decrypt_page(page); |
237fead6 | 228 | if (rc) { |
237fead6 MH |
229 | ecryptfs_printk(KERN_ERR, "Error decrypting page; " |
230 | "rc = [%d]\n", rc); | |
231 | goto out; | |
232 | } | |
233 | } | |
237fead6 | 234 | out: |
16a72c45 MH |
235 | if (rc) |
236 | ClearPageUptodate(page); | |
237 | else | |
238 | SetPageUptodate(page); | |
888d57bb | 239 | ecryptfs_printk(KERN_DEBUG, "Unlocking page with index = [0x%.16lx]\n", |
237fead6 MH |
240 | page->index); |
241 | unlock_page(page); | |
242 | return rc; | |
243 | } | |
244 | ||
dd2a3b7a MH |
245 | /** |
246 | * Called with lower inode mutex held. | |
247 | */ | |
237fead6 MH |
248 | static int fill_zeros_to_end_of_page(struct page *page, unsigned int to) |
249 | { | |
250 | struct inode *inode = page->mapping->host; | |
251 | int end_byte_in_page; | |
237fead6 | 252 | |
09cbfeaf | 253 | if ((i_size_read(inode) / PAGE_SIZE) != page->index) |
9d8b8ce5 | 254 | goto out; |
09cbfeaf | 255 | end_byte_in_page = i_size_read(inode) % PAGE_SIZE; |
9d8b8ce5 MH |
256 | if (to > end_byte_in_page) |
257 | end_byte_in_page = to; | |
09cbfeaf | 258 | zero_user_segment(page, end_byte_in_page, PAGE_SIZE); |
237fead6 | 259 | out: |
9d8b8ce5 | 260 | return 0; |
237fead6 MH |
261 | } |
262 | ||
e4465fda | 263 | /** |
807b7ebe | 264 | * ecryptfs_write_begin |
e4465fda | 265 | * @file: The eCryptfs file |
807b7ebe BP |
266 | * @mapping: The eCryptfs object |
267 | * @pos: The file offset at which to start writing | |
268 | * @len: Length of the write | |
269 | * @flags: Various flags | |
270 | * @pagep: Pointer to return the page | |
271 | * @fsdata: Pointer to return fs data (unused) | |
e4465fda MH |
272 | * |
273 | * This function must zero any hole we create | |
274 | * | |
275 | * Returns zero on success; non-zero otherwise | |
276 | */ | |
807b7ebe BP |
277 | static int ecryptfs_write_begin(struct file *file, |
278 | struct address_space *mapping, | |
279 | loff_t pos, unsigned len, unsigned flags, | |
280 | struct page **pagep, void **fsdata) | |
237fead6 | 281 | { |
09cbfeaf | 282 | pgoff_t index = pos >> PAGE_SHIFT; |
807b7ebe | 283 | struct page *page; |
7a3f595c | 284 | loff_t prev_page_end_size; |
e4465fda | 285 | int rc = 0; |
237fead6 | 286 | |
54566b2c | 287 | page = grab_cache_page_write_begin(mapping, index, flags); |
807b7ebe BP |
288 | if (!page) |
289 | return -ENOMEM; | |
290 | *pagep = page; | |
291 | ||
09cbfeaf | 292 | prev_page_end_size = ((loff_t)index << PAGE_SHIFT); |
16a72c45 | 293 | if (!PageUptodate(page)) { |
e4465fda | 294 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 295 | &ecryptfs_inode_to_private(mapping->host)->crypt_stat; |
e4465fda | 296 | |
fed8859b | 297 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
e4465fda | 298 | rc = ecryptfs_read_lower_page_segment( |
09cbfeaf | 299 | page, index, 0, PAGE_SIZE, mapping->host); |
e4465fda | 300 | if (rc) { |
971bd8fa | 301 | printk(KERN_ERR "%s: Error attempting to read " |
e4465fda | 302 | "lower page segment; rc = [%d]\n", |
18d1dbf1 | 303 | __func__, rc); |
e4465fda MH |
304 | ClearPageUptodate(page); |
305 | goto out; | |
306 | } else | |
307 | SetPageUptodate(page); | |
308 | } else if (crypt_stat->flags & ECRYPTFS_VIEW_AS_ENCRYPTED) { | |
309 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) { | |
310 | rc = ecryptfs_copy_up_encrypted_with_header( | |
311 | page, crypt_stat); | |
312 | if (rc) { | |
313 | printk(KERN_ERR "%s: Error attempting " | |
314 | "to copy the encrypted content " | |
315 | "from the lower file whilst " | |
316 | "inserting the metadata from " | |
317 | "the xattr into the header; rc " | |
18d1dbf1 | 318 | "= [%d]\n", __func__, rc); |
e4465fda MH |
319 | ClearPageUptodate(page); |
320 | goto out; | |
321 | } | |
322 | SetPageUptodate(page); | |
323 | } else { | |
324 | rc = ecryptfs_read_lower_page_segment( | |
09cbfeaf | 325 | page, index, 0, PAGE_SIZE, |
807b7ebe | 326 | mapping->host); |
e4465fda MH |
327 | if (rc) { |
328 | printk(KERN_ERR "%s: Error reading " | |
329 | "page; rc = [%d]\n", | |
18d1dbf1 | 330 | __func__, rc); |
e4465fda MH |
331 | ClearPageUptodate(page); |
332 | goto out; | |
333 | } | |
334 | SetPageUptodate(page); | |
335 | } | |
336 | } else { | |
24562486 FS |
337 | if (prev_page_end_size |
338 | >= i_size_read(page->mapping->host)) { | |
09cbfeaf | 339 | zero_user(page, 0, PAGE_SIZE); |
e4bc6522 | 340 | SetPageUptodate(page); |
09cbfeaf | 341 | } else if (len < PAGE_SIZE) { |
24562486 FS |
342 | rc = ecryptfs_decrypt_page(page); |
343 | if (rc) { | |
344 | printk(KERN_ERR "%s: Error decrypting " | |
345 | "page at index [%ld]; " | |
346 | "rc = [%d]\n", | |
347 | __func__, page->index, rc); | |
348 | ClearPageUptodate(page); | |
349 | goto out; | |
350 | } | |
e4bc6522 | 351 | SetPageUptodate(page); |
e4465fda | 352 | } |
e4465fda | 353 | } |
16a72c45 | 354 | } |
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)) | |
09cbfeaf | 374 | zero_user(page, 0, PAGE_SIZE); |
237fead6 | 375 | out: |
50f198ae TH |
376 | if (unlikely(rc)) { |
377 | unlock_page(page); | |
09cbfeaf | 378 | put_page(page); |
50f198ae TH |
379 | *pagep = NULL; |
380 | } | |
237fead6 MH |
381 | return rc; |
382 | } | |
383 | ||
237fead6 MH |
384 | /** |
385 | * ecryptfs_write_inode_size_to_header | |
386 | * | |
387 | * Writes the lower file size to the first 8 bytes of the header. | |
388 | * | |
389 | * Returns zero on success; non-zero on error. | |
390 | */ | |
0216f7f7 | 391 | static int ecryptfs_write_inode_size_to_header(struct inode *ecryptfs_inode) |
237fead6 | 392 | { |
0216f7f7 MH |
393 | char *file_size_virt; |
394 | int rc; | |
237fead6 | 395 | |
0216f7f7 MH |
396 | file_size_virt = kmalloc(sizeof(u64), GFP_KERNEL); |
397 | if (!file_size_virt) { | |
398 | rc = -ENOMEM; | |
ae73fc09 MH |
399 | goto out; |
400 | } | |
0a688ad7 | 401 | put_unaligned_be64(i_size_read(ecryptfs_inode), file_size_virt); |
0216f7f7 MH |
402 | rc = ecryptfs_write_lower(ecryptfs_inode, file_size_virt, 0, |
403 | sizeof(u64)); | |
404 | kfree(file_size_virt); | |
96a7b9c2 | 405 | if (rc < 0) |
0216f7f7 | 406 | printk(KERN_ERR "%s: Error writing file size to header; " |
18d1dbf1 | 407 | "rc = [%d]\n", __func__, rc); |
96a7b9c2 TH |
408 | else |
409 | rc = 0; | |
237fead6 MH |
410 | out: |
411 | return rc; | |
412 | } | |
413 | ||
0216f7f7 MH |
414 | struct kmem_cache *ecryptfs_xattr_cache; |
415 | ||
416 | static int ecryptfs_write_inode_size_to_xattr(struct inode *ecryptfs_inode) | |
dd2a3b7a MH |
417 | { |
418 | ssize_t size; | |
419 | void *xattr_virt; | |
0216f7f7 | 420 | struct dentry *lower_dentry = |
b583043e | 421 | ecryptfs_inode_to_private(ecryptfs_inode)->lower_file->f_path.dentry; |
2b0143b5 | 422 | struct inode *lower_inode = d_inode(lower_dentry); |
dd2a3b7a MH |
423 | int rc; |
424 | ||
0216f7f7 MH |
425 | if (!lower_inode->i_op->getxattr || !lower_inode->i_op->setxattr) { |
426 | printk(KERN_WARNING | |
427 | "No support for setting xattr in lower filesystem\n"); | |
428 | rc = -ENOSYS; | |
429 | goto out; | |
430 | } | |
dd2a3b7a MH |
431 | xattr_virt = kmem_cache_alloc(ecryptfs_xattr_cache, GFP_KERNEL); |
432 | if (!xattr_virt) { | |
433 | printk(KERN_ERR "Out of memory whilst attempting to write " | |
434 | "inode size to xattr\n"); | |
435 | rc = -ENOMEM; | |
436 | goto out; | |
437 | } | |
5955102c | 438 | inode_lock(lower_inode); |
ce23e640 AV |
439 | size = lower_inode->i_op->getxattr(lower_dentry, lower_inode, |
440 | ECRYPTFS_XATTR_NAME, | |
09cbfeaf | 441 | xattr_virt, PAGE_SIZE); |
dd2a3b7a MH |
442 | if (size < 0) |
443 | size = 8; | |
0a688ad7 | 444 | put_unaligned_be64(i_size_read(ecryptfs_inode), xattr_virt); |
3767e255 AV |
445 | rc = lower_inode->i_op->setxattr(lower_dentry, lower_inode, |
446 | ECRYPTFS_XATTR_NAME, | |
0216f7f7 | 447 | xattr_virt, size, 0); |
5955102c | 448 | inode_unlock(lower_inode); |
dd2a3b7a MH |
449 | if (rc) |
450 | printk(KERN_ERR "Error whilst attempting to write inode size " | |
451 | "to lower file xattr; rc = [%d]\n", rc); | |
452 | kmem_cache_free(ecryptfs_xattr_cache, xattr_virt); | |
453 | out: | |
454 | return rc; | |
455 | } | |
456 | ||
0216f7f7 | 457 | int ecryptfs_write_inode_size_to_metadata(struct inode *ecryptfs_inode) |
dd2a3b7a MH |
458 | { |
459 | struct ecryptfs_crypt_stat *crypt_stat; | |
460 | ||
0216f7f7 | 461 | crypt_stat = &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
13a791b4 | 462 | BUG_ON(!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)); |
dd2a3b7a | 463 | if (crypt_stat->flags & ECRYPTFS_METADATA_IN_XATTR) |
0216f7f7 | 464 | return ecryptfs_write_inode_size_to_xattr(ecryptfs_inode); |
dd2a3b7a | 465 | else |
0216f7f7 | 466 | return ecryptfs_write_inode_size_to_header(ecryptfs_inode); |
dd2a3b7a MH |
467 | } |
468 | ||
237fead6 | 469 | /** |
807b7ebe | 470 | * ecryptfs_write_end |
237fead6 | 471 | * @file: The eCryptfs file object |
807b7ebe BP |
472 | * @mapping: The eCryptfs object |
473 | * @pos: The file position | |
474 | * @len: The length of the data (unused) | |
475 | * @copied: The amount of data copied | |
237fead6 | 476 | * @page: The eCryptfs page |
807b7ebe | 477 | * @fsdata: The fsdata (unused) |
237fead6 | 478 | */ |
807b7ebe BP |
479 | static int ecryptfs_write_end(struct file *file, |
480 | struct address_space *mapping, | |
481 | loff_t pos, unsigned len, unsigned copied, | |
482 | struct page *page, void *fsdata) | |
237fead6 | 483 | { |
09cbfeaf KS |
484 | pgoff_t index = pos >> PAGE_SHIFT; |
485 | unsigned from = pos & (PAGE_SIZE - 1); | |
807b7ebe BP |
486 | unsigned to = from + copied; |
487 | struct inode *ecryptfs_inode = mapping->host; | |
bf12be1c | 488 | struct ecryptfs_crypt_stat *crypt_stat = |
bef5bc24 | 489 | &ecryptfs_inode_to_private(ecryptfs_inode)->crypt_stat; |
237fead6 MH |
490 | int rc; |
491 | ||
237fead6 | 492 | ecryptfs_printk(KERN_DEBUG, "Calling fill_zeros_to_end_of_page" |
888d57bb | 493 | "(page w/ index = [0x%.16lx], to = [%d])\n", index, to); |
13a791b4 TH |
494 | if (!(crypt_stat->flags & ECRYPTFS_ENCRYPTED)) { |
495 | rc = ecryptfs_write_lower_page_segment(ecryptfs_inode, page, 0, | |
496 | to); | |
497 | if (!rc) { | |
498 | rc = copied; | |
499 | fsstack_copy_inode_size(ecryptfs_inode, | |
500 | ecryptfs_inode_to_lower(ecryptfs_inode)); | |
501 | } | |
502 | goto out; | |
503 | } | |
e4bc6522 | 504 | if (!PageUptodate(page)) { |
09cbfeaf | 505 | if (copied < PAGE_SIZE) { |
e4bc6522 LW |
506 | rc = 0; |
507 | goto out; | |
508 | } | |
509 | SetPageUptodate(page); | |
510 | } | |
bf12be1c | 511 | /* Fills in zeros if 'to' goes beyond inode size */ |
237fead6 MH |
512 | rc = fill_zeros_to_end_of_page(page, to); |
513 | if (rc) { | |
514 | ecryptfs_printk(KERN_WARNING, "Error attempting to fill " | |
888d57bb | 515 | "zeros in page with index = [0x%.16lx]\n", index); |
237fead6 MH |
516 | goto out; |
517 | } | |
821f7494 TH |
518 | rc = ecryptfs_encrypt_page(page); |
519 | if (rc) { | |
520 | ecryptfs_printk(KERN_WARNING, "Error encrypting page (upper " | |
521 | "index [0x%.16lx])\n", index); | |
522 | goto out; | |
523 | } | |
807b7ebe BP |
524 | if (pos + copied > i_size_read(ecryptfs_inode)) { |
525 | i_size_write(ecryptfs_inode, pos + copied); | |
237fead6 | 526 | ecryptfs_printk(KERN_DEBUG, "Expanded file size to " |
888d57bb JP |
527 | "[0x%.16llx]\n", |
528 | (unsigned long long)i_size_read(ecryptfs_inode)); | |
237fead6 | 529 | } |
821f7494 TH |
530 | rc = ecryptfs_write_inode_size_to_metadata(ecryptfs_inode); |
531 | if (rc) | |
532 | printk(KERN_ERR "Error writing inode size to metadata; " | |
533 | "rc = [%d]\n", rc); | |
534 | else | |
535 | rc = copied; | |
237fead6 | 536 | out: |
821f7494 | 537 | unlock_page(page); |
09cbfeaf | 538 | put_page(page); |
237fead6 MH |
539 | return rc; |
540 | } | |
541 | ||
237fead6 MH |
542 | static sector_t ecryptfs_bmap(struct address_space *mapping, sector_t block) |
543 | { | |
544 | int rc = 0; | |
545 | struct inode *inode; | |
546 | struct inode *lower_inode; | |
547 | ||
548 | inode = (struct inode *)mapping->host; | |
549 | lower_inode = ecryptfs_inode_to_lower(inode); | |
550 | if (lower_inode->i_mapping->a_ops->bmap) | |
551 | rc = lower_inode->i_mapping->a_ops->bmap(lower_inode->i_mapping, | |
552 | block); | |
553 | return rc; | |
554 | } | |
555 | ||
7f09410b | 556 | const struct address_space_operations ecryptfs_aops = { |
237fead6 MH |
557 | .writepage = ecryptfs_writepage, |
558 | .readpage = ecryptfs_readpage, | |
807b7ebe BP |
559 | .write_begin = ecryptfs_write_begin, |
560 | .write_end = ecryptfs_write_end, | |
237fead6 | 561 | .bmap = ecryptfs_bmap, |
237fead6 | 562 | }; |