Commit | Line | Data |
---|---|---|
61159a31 RW |
1 | /* |
2 | * linux/kernel/power/swap.c | |
3 | * | |
4 | * This file provides functions for reading the suspend image from | |
5 | * and writing it to a swap partition. | |
6 | * | |
7 | * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@suse.cz> | |
8 | * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> | |
9 | * | |
10 | * This file is released under the GPLv2. | |
11 | * | |
12 | */ | |
13 | ||
14 | #include <linux/module.h> | |
61159a31 RW |
15 | #include <linux/file.h> |
16 | #include <linux/utsname.h> | |
61159a31 RW |
17 | #include <linux/delay.h> |
18 | #include <linux/bitops.h> | |
19 | #include <linux/genhd.h> | |
20 | #include <linux/device.h> | |
21 | #include <linux/buffer_head.h> | |
22 | #include <linux/bio.h> | |
546e0d27 | 23 | #include <linux/blkdev.h> |
61159a31 RW |
24 | #include <linux/swap.h> |
25 | #include <linux/swapops.h> | |
26 | #include <linux/pm.h> | |
27 | ||
28 | #include "power.h" | |
29 | ||
61159a31 RW |
30 | #define SWSUSP_SIG "S1SUSPEND" |
31 | ||
1b29c164 | 32 | struct swsusp_header { |
a634cc10 | 33 | char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; |
3aef83e0 | 34 | sector_t image; |
a634cc10 | 35 | unsigned int flags; /* Flags to pass to the "boot" kernel */ |
61159a31 RW |
36 | char orig_sig[10]; |
37 | char sig[10]; | |
1b29c164 VG |
38 | } __attribute__((packed)); |
39 | ||
40 | static struct swsusp_header *swsusp_header; | |
61159a31 RW |
41 | |
42 | /* | |
3fc6b34f | 43 | * General things |
61159a31 RW |
44 | */ |
45 | ||
46 | static unsigned short root_swap = 0xffff; | |
3fc6b34f RW |
47 | static struct block_device *resume_bdev; |
48 | ||
49 | /** | |
50 | * submit - submit BIO request. | |
51 | * @rw: READ or WRITE. | |
52 | * @off physical offset of page. | |
53 | * @page: page we're reading or writing. | |
54 | * @bio_chain: list of pending biod (for async reading) | |
55 | * | |
56 | * Straight from the textbook - allocate and initialize the bio. | |
57 | * If we're reading, make sure the page is marked as dirty. | |
58 | * Then submit it and, if @bio_chain == NULL, wait. | |
59 | */ | |
60 | static int submit(int rw, pgoff_t page_off, struct page *page, | |
61 | struct bio **bio_chain) | |
62 | { | |
63 | struct bio *bio; | |
64 | ||
85949121 | 65 | bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1); |
3fc6b34f RW |
66 | if (!bio) |
67 | return -ENOMEM; | |
68 | bio->bi_sector = page_off * (PAGE_SIZE >> 9); | |
69 | bio->bi_bdev = resume_bdev; | |
70 | bio->bi_end_io = end_swap_bio_read; | |
71 | ||
72 | if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { | |
23976728 RW |
73 | printk(KERN_ERR "PM: Adding page to bio failed at %ld\n", |
74 | page_off); | |
3fc6b34f RW |
75 | bio_put(bio); |
76 | return -EFAULT; | |
77 | } | |
78 | ||
79 | lock_page(page); | |
80 | bio_get(bio); | |
81 | ||
82 | if (bio_chain == NULL) { | |
83 | submit_bio(rw | (1 << BIO_RW_SYNC), bio); | |
84 | wait_on_page_locked(page); | |
85 | if (rw == READ) | |
86 | bio_set_pages_dirty(bio); | |
87 | bio_put(bio); | |
88 | } else { | |
89 | if (rw == READ) | |
90 | get_page(page); /* These pages are freed later */ | |
91 | bio->bi_private = *bio_chain; | |
92 | *bio_chain = bio; | |
93 | submit_bio(rw | (1 << BIO_RW_SYNC), bio); | |
94 | } | |
95 | return 0; | |
96 | } | |
97 | ||
98 | static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain) | |
99 | { | |
100 | return submit(READ, page_off, virt_to_page(addr), bio_chain); | |
101 | } | |
102 | ||
3aef83e0 | 103 | static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain) |
3fc6b34f | 104 | { |
3aef83e0 | 105 | return submit(WRITE, page_off, virt_to_page(addr), bio_chain); |
3fc6b34f RW |
106 | } |
107 | ||
108 | static int wait_on_bio_chain(struct bio **bio_chain) | |
109 | { | |
110 | struct bio *bio; | |
111 | struct bio *next_bio; | |
112 | int ret = 0; | |
113 | ||
114 | if (bio_chain == NULL) | |
115 | return 0; | |
116 | ||
117 | bio = *bio_chain; | |
118 | if (bio == NULL) | |
119 | return 0; | |
120 | while (bio) { | |
121 | struct page *page; | |
122 | ||
123 | next_bio = bio->bi_private; | |
124 | page = bio->bi_io_vec[0].bv_page; | |
125 | wait_on_page_locked(page); | |
126 | if (!PageUptodate(page) || PageError(page)) | |
127 | ret = -EIO; | |
128 | put_page(page); | |
129 | bio_put(bio); | |
130 | bio = next_bio; | |
131 | } | |
132 | *bio_chain = NULL; | |
133 | return ret; | |
134 | } | |
135 | ||
3fc6b34f RW |
136 | /* |
137 | * Saving part | |
138 | */ | |
61159a31 | 139 | |
a634cc10 | 140 | static int mark_swapfiles(sector_t start, unsigned int flags) |
61159a31 RW |
141 | { |
142 | int error; | |
143 | ||
1b29c164 VG |
144 | bio_read_page(swsusp_resume_block, swsusp_header, NULL); |
145 | if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || | |
146 | !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { | |
147 | memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); | |
148 | memcpy(swsusp_header->sig,SWSUSP_SIG, 10); | |
149 | swsusp_header->image = start; | |
a634cc10 | 150 | swsusp_header->flags = flags; |
9a154d9d | 151 | error = bio_write_page(swsusp_resume_block, |
1b29c164 | 152 | swsusp_header, NULL); |
61159a31 | 153 | } else { |
23976728 | 154 | printk(KERN_ERR "PM: Swap header not found!\n"); |
61159a31 RW |
155 | error = -ENODEV; |
156 | } | |
157 | return error; | |
158 | } | |
159 | ||
160 | /** | |
161 | * swsusp_swap_check - check if the resume device is a swap device | |
162 | * and get its index (if so) | |
163 | */ | |
164 | ||
165 | static int swsusp_swap_check(void) /* This is called before saving image */ | |
166 | { | |
3aef83e0 RW |
167 | int res; |
168 | ||
7bf23687 RW |
169 | res = swap_type_of(swsusp_resume_device, swsusp_resume_block, |
170 | &resume_bdev); | |
3aef83e0 RW |
171 | if (res < 0) |
172 | return res; | |
173 | ||
174 | root_swap = res; | |
7bf23687 RW |
175 | res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR); |
176 | if (res) | |
177 | return res; | |
3aef83e0 RW |
178 | |
179 | res = set_blocksize(resume_bdev, PAGE_SIZE); | |
180 | if (res < 0) | |
181 | blkdev_put(resume_bdev); | |
61159a31 | 182 | |
61159a31 RW |
183 | return res; |
184 | } | |
185 | ||
186 | /** | |
187 | * write_page - Write one page to given swap location. | |
188 | * @buf: Address we're writing. | |
189 | * @offset: Offset of the swap page we're writing to. | |
ab954160 | 190 | * @bio_chain: Link the next write BIO here |
61159a31 RW |
191 | */ |
192 | ||
3aef83e0 | 193 | static int write_page(void *buf, sector_t offset, struct bio **bio_chain) |
61159a31 | 194 | { |
3aef83e0 RW |
195 | void *src; |
196 | ||
197 | if (!offset) | |
198 | return -ENOSPC; | |
199 | ||
200 | if (bio_chain) { | |
85949121 | 201 | src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); |
3aef83e0 RW |
202 | if (src) { |
203 | memcpy(src, buf, PAGE_SIZE); | |
204 | } else { | |
205 | WARN_ON_ONCE(1); | |
206 | bio_chain = NULL; /* Go synchronous */ | |
207 | src = buf; | |
ab954160 | 208 | } |
3aef83e0 RW |
209 | } else { |
210 | src = buf; | |
61159a31 | 211 | } |
3aef83e0 | 212 | return bio_write_page(offset, src, bio_chain); |
61159a31 RW |
213 | } |
214 | ||
215 | /* | |
216 | * The swap map is a data structure used for keeping track of each page | |
217 | * written to a swap partition. It consists of many swap_map_page | |
218 | * structures that contain each an array of MAP_PAGE_SIZE swap entries. | |
219 | * These structures are stored on the swap and linked together with the | |
220 | * help of the .next_swap member. | |
221 | * | |
222 | * The swap map is created during suspend. The swap map pages are | |
223 | * allocated and populated one at a time, so we only need one memory | |
224 | * page to set up the entire structure. | |
225 | * | |
226 | * During resume we also only need to use one swap_map_page structure | |
227 | * at a time. | |
228 | */ | |
229 | ||
3aef83e0 | 230 | #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) |
61159a31 RW |
231 | |
232 | struct swap_map_page { | |
3aef83e0 RW |
233 | sector_t entries[MAP_PAGE_ENTRIES]; |
234 | sector_t next_swap; | |
61159a31 RW |
235 | }; |
236 | ||
237 | /** | |
238 | * The swap_map_handle structure is used for handling swap in | |
239 | * a file-alike way | |
240 | */ | |
241 | ||
242 | struct swap_map_handle { | |
243 | struct swap_map_page *cur; | |
3aef83e0 | 244 | sector_t cur_swap; |
61159a31 RW |
245 | unsigned int k; |
246 | }; | |
247 | ||
248 | static void release_swap_writer(struct swap_map_handle *handle) | |
249 | { | |
250 | if (handle->cur) | |
251 | free_page((unsigned long)handle->cur); | |
252 | handle->cur = NULL; | |
61159a31 RW |
253 | } |
254 | ||
255 | static int get_swap_writer(struct swap_map_handle *handle) | |
256 | { | |
257 | handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); | |
258 | if (!handle->cur) | |
259 | return -ENOMEM; | |
d1d241cc | 260 | handle->cur_swap = alloc_swapdev_block(root_swap); |
61159a31 RW |
261 | if (!handle->cur_swap) { |
262 | release_swap_writer(handle); | |
263 | return -ENOSPC; | |
264 | } | |
265 | handle->k = 0; | |
266 | return 0; | |
267 | } | |
268 | ||
ab954160 AM |
269 | static int swap_write_page(struct swap_map_handle *handle, void *buf, |
270 | struct bio **bio_chain) | |
271 | { | |
272 | int error = 0; | |
3aef83e0 | 273 | sector_t offset; |
61159a31 RW |
274 | |
275 | if (!handle->cur) | |
276 | return -EINVAL; | |
d1d241cc | 277 | offset = alloc_swapdev_block(root_swap); |
ab954160 | 278 | error = write_page(buf, offset, bio_chain); |
61159a31 RW |
279 | if (error) |
280 | return error; | |
281 | handle->cur->entries[handle->k++] = offset; | |
282 | if (handle->k >= MAP_PAGE_ENTRIES) { | |
ab954160 AM |
283 | error = wait_on_bio_chain(bio_chain); |
284 | if (error) | |
285 | goto out; | |
d1d241cc | 286 | offset = alloc_swapdev_block(root_swap); |
61159a31 RW |
287 | if (!offset) |
288 | return -ENOSPC; | |
289 | handle->cur->next_swap = offset; | |
ab954160 | 290 | error = write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 | 291 | if (error) |
ab954160 | 292 | goto out; |
61159a31 RW |
293 | memset(handle->cur, 0, PAGE_SIZE); |
294 | handle->cur_swap = offset; | |
295 | handle->k = 0; | |
296 | } | |
59a49335 | 297 | out: |
ab954160 | 298 | return error; |
61159a31 RW |
299 | } |
300 | ||
301 | static int flush_swap_writer(struct swap_map_handle *handle) | |
302 | { | |
303 | if (handle->cur && handle->cur_swap) | |
ab954160 | 304 | return write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 RW |
305 | else |
306 | return -EINVAL; | |
307 | } | |
308 | ||
309 | /** | |
310 | * save_image - save the suspend image data | |
311 | */ | |
312 | ||
313 | static int save_image(struct swap_map_handle *handle, | |
314 | struct snapshot_handle *snapshot, | |
3a4f7577 | 315 | unsigned int nr_to_write) |
61159a31 RW |
316 | { |
317 | unsigned int m; | |
318 | int ret; | |
319 | int error = 0; | |
3a4f7577 | 320 | int nr_pages; |
ab954160 AM |
321 | int err2; |
322 | struct bio *bio; | |
3a4f7577 AM |
323 | struct timeval start; |
324 | struct timeval stop; | |
61159a31 | 325 | |
23976728 RW |
326 | printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ", |
327 | nr_to_write); | |
3a4f7577 | 328 | m = nr_to_write / 100; |
61159a31 RW |
329 | if (!m) |
330 | m = 1; | |
331 | nr_pages = 0; | |
ab954160 | 332 | bio = NULL; |
3a4f7577 | 333 | do_gettimeofday(&start); |
61159a31 RW |
334 | do { |
335 | ret = snapshot_read_next(snapshot, PAGE_SIZE); | |
336 | if (ret > 0) { | |
ab954160 AM |
337 | error = swap_write_page(handle, data_of(*snapshot), |
338 | &bio); | |
61159a31 RW |
339 | if (error) |
340 | break; | |
341 | if (!(nr_pages % m)) | |
342 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
343 | nr_pages++; | |
344 | } | |
345 | } while (ret > 0); | |
ab954160 | 346 | err2 = wait_on_bio_chain(&bio); |
3a4f7577 | 347 | do_gettimeofday(&stop); |
ab954160 AM |
348 | if (!error) |
349 | error = err2; | |
61159a31 RW |
350 | if (!error) |
351 | printk("\b\b\b\bdone\n"); | |
0d3a9abe | 352 | swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); |
61159a31 RW |
353 | return error; |
354 | } | |
355 | ||
356 | /** | |
357 | * enough_swap - Make sure we have enough swap to save the image. | |
358 | * | |
359 | * Returns TRUE or FALSE after checking the total amount of swap | |
360 | * space avaiable from the resume partition. | |
361 | */ | |
362 | ||
363 | static int enough_swap(unsigned int nr_pages) | |
364 | { | |
365 | unsigned int free_swap = count_swap_pages(root_swap, 1); | |
366 | ||
23976728 | 367 | pr_debug("PM: Free swap pages: %u\n", free_swap); |
940864dd | 368 | return free_swap > nr_pages + PAGES_FOR_IO; |
61159a31 RW |
369 | } |
370 | ||
371 | /** | |
372 | * swsusp_write - Write entire image and metadata. | |
a634cc10 | 373 | * @flags: flags to pass to the "boot" kernel in the image header |
61159a31 RW |
374 | * |
375 | * It is important _NOT_ to umount filesystems at this point. We want | |
376 | * them synced (in case something goes wrong) but we DO not want to mark | |
377 | * filesystem clean: it is not. (And it does not matter, if we resume | |
378 | * correctly, we'll mark system clean, anyway.) | |
379 | */ | |
380 | ||
a634cc10 | 381 | int swsusp_write(unsigned int flags) |
61159a31 RW |
382 | { |
383 | struct swap_map_handle handle; | |
384 | struct snapshot_handle snapshot; | |
385 | struct swsusp_info *header; | |
61159a31 RW |
386 | int error; |
387 | ||
3aef83e0 RW |
388 | error = swsusp_swap_check(); |
389 | if (error) { | |
23976728 | 390 | printk(KERN_ERR "PM: Cannot find swap device, try " |
546e0d27 | 391 | "swapon -a.\n"); |
61159a31 RW |
392 | return error; |
393 | } | |
394 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
395 | error = snapshot_read_next(&snapshot, PAGE_SIZE); | |
3aef83e0 RW |
396 | if (error < PAGE_SIZE) { |
397 | if (error >= 0) | |
398 | error = -EFAULT; | |
399 | ||
400 | goto out; | |
401 | } | |
61159a31 RW |
402 | header = (struct swsusp_info *)data_of(snapshot); |
403 | if (!enough_swap(header->pages)) { | |
23976728 | 404 | printk(KERN_ERR "PM: Not enough free swap\n"); |
3aef83e0 RW |
405 | error = -ENOSPC; |
406 | goto out; | |
61159a31 RW |
407 | } |
408 | error = get_swap_writer(&handle); | |
409 | if (!error) { | |
3aef83e0 RW |
410 | sector_t start = handle.cur_swap; |
411 | ||
ab954160 | 412 | error = swap_write_page(&handle, header, NULL); |
712f403a AM |
413 | if (!error) |
414 | error = save_image(&handle, &snapshot, | |
415 | header->pages - 1); | |
3aef83e0 | 416 | |
712f403a AM |
417 | if (!error) { |
418 | flush_swap_writer(&handle); | |
23976728 | 419 | printk(KERN_INFO "PM: S"); |
a634cc10 | 420 | error = mark_swapfiles(start, flags); |
712f403a AM |
421 | printk("|\n"); |
422 | } | |
61159a31 RW |
423 | } |
424 | if (error) | |
d1d241cc RW |
425 | free_all_swap_pages(root_swap); |
426 | ||
61159a31 | 427 | release_swap_writer(&handle); |
59a49335 | 428 | out: |
3aef83e0 | 429 | swsusp_close(); |
61159a31 RW |
430 | return error; |
431 | } | |
432 | ||
61159a31 RW |
433 | /** |
434 | * The following functions allow us to read data using a swap map | |
435 | * in a file-alike way | |
436 | */ | |
437 | ||
438 | static void release_swap_reader(struct swap_map_handle *handle) | |
439 | { | |
440 | if (handle->cur) | |
441 | free_page((unsigned long)handle->cur); | |
442 | handle->cur = NULL; | |
443 | } | |
444 | ||
3aef83e0 | 445 | static int get_swap_reader(struct swap_map_handle *handle, sector_t start) |
61159a31 RW |
446 | { |
447 | int error; | |
448 | ||
3aef83e0 | 449 | if (!start) |
61159a31 | 450 | return -EINVAL; |
3aef83e0 | 451 | |
85949121 | 452 | handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); |
61159a31 RW |
453 | if (!handle->cur) |
454 | return -ENOMEM; | |
3aef83e0 RW |
455 | |
456 | error = bio_read_page(start, handle->cur, NULL); | |
61159a31 RW |
457 | if (error) { |
458 | release_swap_reader(handle); | |
459 | return error; | |
460 | } | |
461 | handle->k = 0; | |
462 | return 0; | |
463 | } | |
464 | ||
546e0d27 AM |
465 | static int swap_read_page(struct swap_map_handle *handle, void *buf, |
466 | struct bio **bio_chain) | |
61159a31 | 467 | { |
3aef83e0 | 468 | sector_t offset; |
61159a31 RW |
469 | int error; |
470 | ||
471 | if (!handle->cur) | |
472 | return -EINVAL; | |
473 | offset = handle->cur->entries[handle->k]; | |
474 | if (!offset) | |
475 | return -EFAULT; | |
546e0d27 | 476 | error = bio_read_page(offset, buf, bio_chain); |
61159a31 RW |
477 | if (error) |
478 | return error; | |
479 | if (++handle->k >= MAP_PAGE_ENTRIES) { | |
546e0d27 | 480 | error = wait_on_bio_chain(bio_chain); |
61159a31 RW |
481 | handle->k = 0; |
482 | offset = handle->cur->next_swap; | |
483 | if (!offset) | |
484 | release_swap_reader(handle); | |
546e0d27 AM |
485 | else if (!error) |
486 | error = bio_read_page(offset, handle->cur, NULL); | |
61159a31 RW |
487 | } |
488 | return error; | |
489 | } | |
490 | ||
491 | /** | |
492 | * load_image - load the image using the swap map handle | |
493 | * @handle and the snapshot handle @snapshot | |
494 | * (assume there are @nr_pages pages to load) | |
495 | */ | |
496 | ||
497 | static int load_image(struct swap_map_handle *handle, | |
498 | struct snapshot_handle *snapshot, | |
546e0d27 | 499 | unsigned int nr_to_read) |
61159a31 RW |
500 | { |
501 | unsigned int m; | |
61159a31 | 502 | int error = 0; |
8c002494 AM |
503 | struct timeval start; |
504 | struct timeval stop; | |
546e0d27 AM |
505 | struct bio *bio; |
506 | int err2; | |
507 | unsigned nr_pages; | |
61159a31 | 508 | |
23976728 RW |
509 | printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", |
510 | nr_to_read); | |
546e0d27 | 511 | m = nr_to_read / 100; |
61159a31 RW |
512 | if (!m) |
513 | m = 1; | |
514 | nr_pages = 0; | |
546e0d27 | 515 | bio = NULL; |
8c002494 | 516 | do_gettimeofday(&start); |
546e0d27 AM |
517 | for ( ; ; ) { |
518 | error = snapshot_write_next(snapshot, PAGE_SIZE); | |
519 | if (error <= 0) | |
520 | break; | |
521 | error = swap_read_page(handle, data_of(*snapshot), &bio); | |
522 | if (error) | |
523 | break; | |
524 | if (snapshot->sync_read) | |
525 | error = wait_on_bio_chain(&bio); | |
526 | if (error) | |
527 | break; | |
528 | if (!(nr_pages % m)) | |
529 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
530 | nr_pages++; | |
531 | } | |
532 | err2 = wait_on_bio_chain(&bio); | |
8c002494 | 533 | do_gettimeofday(&stop); |
546e0d27 AM |
534 | if (!error) |
535 | error = err2; | |
e655a250 | 536 | if (!error) { |
61159a31 | 537 | printk("\b\b\b\bdone\n"); |
8357376d | 538 | snapshot_write_finalize(snapshot); |
e655a250 CK |
539 | if (!snapshot_image_loaded(snapshot)) |
540 | error = -ENODATA; | |
541 | } | |
0d3a9abe | 542 | swsusp_show_speed(&start, &stop, nr_to_read, "Read"); |
61159a31 RW |
543 | return error; |
544 | } | |
545 | ||
a634cc10 RW |
546 | /** |
547 | * swsusp_read - read the hibernation image. | |
548 | * @flags_p: flags passed by the "frozen" kernel in the image header should | |
549 | * be written into this memeory location | |
550 | */ | |
551 | ||
552 | int swsusp_read(unsigned int *flags_p) | |
61159a31 RW |
553 | { |
554 | int error; | |
555 | struct swap_map_handle handle; | |
556 | struct snapshot_handle snapshot; | |
557 | struct swsusp_info *header; | |
558 | ||
a634cc10 | 559 | *flags_p = swsusp_header->flags; |
61159a31 | 560 | if (IS_ERR(resume_bdev)) { |
23976728 | 561 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
562 | return PTR_ERR(resume_bdev); |
563 | } | |
564 | ||
565 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
566 | error = snapshot_write_next(&snapshot, PAGE_SIZE); | |
567 | if (error < PAGE_SIZE) | |
568 | return error < 0 ? error : -EFAULT; | |
569 | header = (struct swsusp_info *)data_of(snapshot); | |
1b29c164 | 570 | error = get_swap_reader(&handle, swsusp_header->image); |
61159a31 | 571 | if (!error) |
546e0d27 | 572 | error = swap_read_page(&handle, header, NULL); |
61159a31 RW |
573 | if (!error) |
574 | error = load_image(&handle, &snapshot, header->pages - 1); | |
575 | release_swap_reader(&handle); | |
576 | ||
577 | blkdev_put(resume_bdev); | |
578 | ||
579 | if (!error) | |
23976728 | 580 | pr_debug("PM: Image successfully loaded\n"); |
61159a31 | 581 | else |
23976728 | 582 | pr_debug("PM: Error %d resuming\n", error); |
61159a31 RW |
583 | return error; |
584 | } | |
585 | ||
586 | /** | |
587 | * swsusp_check - Check for swsusp signature in the resume device | |
588 | */ | |
589 | ||
590 | int swsusp_check(void) | |
591 | { | |
592 | int error; | |
593 | ||
594 | resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); | |
595 | if (!IS_ERR(resume_bdev)) { | |
596 | set_blocksize(resume_bdev, PAGE_SIZE); | |
6373da1f | 597 | memset(swsusp_header, 0, PAGE_SIZE); |
9a154d9d | 598 | error = bio_read_page(swsusp_resume_block, |
1b29c164 | 599 | swsusp_header, NULL); |
9a154d9d | 600 | if (error) |
61159a31 | 601 | return error; |
9a154d9d | 602 | |
1b29c164 VG |
603 | if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) { |
604 | memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); | |
61159a31 | 605 | /* Reset swap signature now */ |
9a154d9d | 606 | error = bio_write_page(swsusp_resume_block, |
1b29c164 | 607 | swsusp_header, NULL); |
61159a31 RW |
608 | } else { |
609 | return -EINVAL; | |
610 | } | |
611 | if (error) | |
612 | blkdev_put(resume_bdev); | |
613 | else | |
23976728 | 614 | pr_debug("PM: Signature found, resuming\n"); |
61159a31 RW |
615 | } else { |
616 | error = PTR_ERR(resume_bdev); | |
617 | } | |
618 | ||
619 | if (error) | |
23976728 | 620 | pr_debug("PM: Error %d checking image file\n", error); |
61159a31 RW |
621 | |
622 | return error; | |
623 | } | |
624 | ||
625 | /** | |
626 | * swsusp_close - close swap device. | |
627 | */ | |
628 | ||
629 | void swsusp_close(void) | |
630 | { | |
631 | if (IS_ERR(resume_bdev)) { | |
23976728 | 632 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
633 | return; |
634 | } | |
635 | ||
636 | blkdev_put(resume_bdev); | |
637 | } | |
1b29c164 VG |
638 | |
639 | static int swsusp_header_init(void) | |
640 | { | |
641 | swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); | |
642 | if (!swsusp_header) | |
643 | panic("Could not allocate memory for swsusp_header\n"); | |
644 | return 0; | |
645 | } | |
646 | ||
647 | core_initcall(swsusp_header_init); |