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