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