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 | 15 | #include <linux/file.h> |
61159a31 RW |
16 | #include <linux/delay.h> |
17 | #include <linux/bitops.h> | |
18 | #include <linux/genhd.h> | |
19 | #include <linux/device.h> | |
20 | #include <linux/buffer_head.h> | |
21 | #include <linux/bio.h> | |
546e0d27 | 22 | #include <linux/blkdev.h> |
61159a31 RW |
23 | #include <linux/swap.h> |
24 | #include <linux/swapops.h> | |
25 | #include <linux/pm.h> | |
26 | ||
27 | #include "power.h" | |
28 | ||
61159a31 RW |
29 | #define SWSUSP_SIG "S1SUSPEND" |
30 | ||
1b29c164 | 31 | struct swsusp_header { |
a634cc10 | 32 | char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; |
3aef83e0 | 33 | sector_t image; |
a634cc10 | 34 | unsigned int flags; /* Flags to pass to the "boot" kernel */ |
61159a31 RW |
35 | char orig_sig[10]; |
36 | char sig[10]; | |
1b29c164 VG |
37 | } __attribute__((packed)); |
38 | ||
39 | static struct swsusp_header *swsusp_header; | |
61159a31 RW |
40 | |
41 | /* | |
3fc6b34f | 42 | * General things |
61159a31 RW |
43 | */ |
44 | ||
45 | static unsigned short root_swap = 0xffff; | |
3fc6b34f RW |
46 | static struct block_device *resume_bdev; |
47 | ||
48 | /** | |
49 | * submit - submit BIO request. | |
50 | * @rw: READ or WRITE. | |
51 | * @off physical offset of page. | |
52 | * @page: page we're reading or writing. | |
53 | * @bio_chain: list of pending biod (for async reading) | |
54 | * | |
55 | * Straight from the textbook - allocate and initialize the bio. | |
56 | * If we're reading, make sure the page is marked as dirty. | |
57 | * Then submit it and, if @bio_chain == NULL, wait. | |
58 | */ | |
59 | static int submit(int rw, pgoff_t page_off, struct page *page, | |
60 | struct bio **bio_chain) | |
61 | { | |
93dbb393 | 62 | const int bio_rw = rw | (1 << BIO_RW_SYNCIO) | (1 << BIO_RW_UNPLUG); |
3fc6b34f RW |
63 | struct bio *bio; |
64 | ||
85949121 | 65 | bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1); |
3fc6b34f RW |
66 | bio->bi_sector = page_off * (PAGE_SIZE >> 9); |
67 | bio->bi_bdev = resume_bdev; | |
68 | bio->bi_end_io = end_swap_bio_read; | |
69 | ||
70 | if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { | |
23976728 RW |
71 | printk(KERN_ERR "PM: Adding page to bio failed at %ld\n", |
72 | page_off); | |
3fc6b34f RW |
73 | bio_put(bio); |
74 | return -EFAULT; | |
75 | } | |
76 | ||
77 | lock_page(page); | |
78 | bio_get(bio); | |
79 | ||
80 | if (bio_chain == NULL) { | |
93dbb393 | 81 | submit_bio(bio_rw, bio); |
3fc6b34f RW |
82 | wait_on_page_locked(page); |
83 | if (rw == READ) | |
84 | bio_set_pages_dirty(bio); | |
85 | bio_put(bio); | |
86 | } else { | |
87 | if (rw == READ) | |
88 | get_page(page); /* These pages are freed later */ | |
89 | bio->bi_private = *bio_chain; | |
90 | *bio_chain = bio; | |
93dbb393 | 91 | submit_bio(bio_rw, bio); |
3fc6b34f RW |
92 | } |
93 | return 0; | |
94 | } | |
95 | ||
96 | static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain) | |
97 | { | |
98 | return submit(READ, page_off, virt_to_page(addr), bio_chain); | |
99 | } | |
100 | ||
3aef83e0 | 101 | static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain) |
3fc6b34f | 102 | { |
3aef83e0 | 103 | return submit(WRITE, page_off, virt_to_page(addr), bio_chain); |
3fc6b34f RW |
104 | } |
105 | ||
106 | static int wait_on_bio_chain(struct bio **bio_chain) | |
107 | { | |
108 | struct bio *bio; | |
109 | struct bio *next_bio; | |
110 | int ret = 0; | |
111 | ||
112 | if (bio_chain == NULL) | |
113 | return 0; | |
114 | ||
115 | bio = *bio_chain; | |
116 | if (bio == NULL) | |
117 | return 0; | |
118 | while (bio) { | |
119 | struct page *page; | |
120 | ||
121 | next_bio = bio->bi_private; | |
122 | page = bio->bi_io_vec[0].bv_page; | |
123 | wait_on_page_locked(page); | |
124 | if (!PageUptodate(page) || PageError(page)) | |
125 | ret = -EIO; | |
126 | put_page(page); | |
127 | bio_put(bio); | |
128 | bio = next_bio; | |
129 | } | |
130 | *bio_chain = NULL; | |
131 | return ret; | |
132 | } | |
133 | ||
3fc6b34f RW |
134 | /* |
135 | * Saving part | |
136 | */ | |
61159a31 | 137 | |
a634cc10 | 138 | static int mark_swapfiles(sector_t start, unsigned int flags) |
61159a31 RW |
139 | { |
140 | int error; | |
141 | ||
1b29c164 VG |
142 | bio_read_page(swsusp_resume_block, swsusp_header, NULL); |
143 | if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || | |
144 | !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { | |
145 | memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); | |
146 | memcpy(swsusp_header->sig,SWSUSP_SIG, 10); | |
147 | swsusp_header->image = start; | |
a634cc10 | 148 | swsusp_header->flags = flags; |
9a154d9d | 149 | error = bio_write_page(swsusp_resume_block, |
1b29c164 | 150 | swsusp_header, NULL); |
61159a31 | 151 | } else { |
23976728 | 152 | printk(KERN_ERR "PM: Swap header not found!\n"); |
61159a31 RW |
153 | error = -ENODEV; |
154 | } | |
155 | return error; | |
156 | } | |
157 | ||
158 | /** | |
159 | * swsusp_swap_check - check if the resume device is a swap device | |
160 | * and get its index (if so) | |
161 | */ | |
162 | ||
163 | static int swsusp_swap_check(void) /* This is called before saving image */ | |
164 | { | |
3aef83e0 RW |
165 | int res; |
166 | ||
7bf23687 RW |
167 | res = swap_type_of(swsusp_resume_device, swsusp_resume_block, |
168 | &resume_bdev); | |
3aef83e0 RW |
169 | if (res < 0) |
170 | return res; | |
171 | ||
172 | root_swap = res; | |
572c4892 | 173 | res = blkdev_get(resume_bdev, FMODE_WRITE); |
7bf23687 RW |
174 | if (res) |
175 | return res; | |
3aef83e0 RW |
176 | |
177 | res = set_blocksize(resume_bdev, PAGE_SIZE); | |
178 | if (res < 0) | |
9a1c3542 | 179 | blkdev_put(resume_bdev, FMODE_WRITE); |
61159a31 | 180 | |
61159a31 RW |
181 | return res; |
182 | } | |
183 | ||
184 | /** | |
185 | * write_page - Write one page to given swap location. | |
186 | * @buf: Address we're writing. | |
187 | * @offset: Offset of the swap page we're writing to. | |
ab954160 | 188 | * @bio_chain: Link the next write BIO here |
61159a31 RW |
189 | */ |
190 | ||
3aef83e0 | 191 | static int write_page(void *buf, sector_t offset, struct bio **bio_chain) |
61159a31 | 192 | { |
3aef83e0 RW |
193 | void *src; |
194 | ||
195 | if (!offset) | |
196 | return -ENOSPC; | |
197 | ||
198 | if (bio_chain) { | |
85949121 | 199 | src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); |
3aef83e0 RW |
200 | if (src) { |
201 | memcpy(src, buf, PAGE_SIZE); | |
202 | } else { | |
203 | WARN_ON_ONCE(1); | |
204 | bio_chain = NULL; /* Go synchronous */ | |
205 | src = buf; | |
ab954160 | 206 | } |
3aef83e0 RW |
207 | } else { |
208 | src = buf; | |
61159a31 | 209 | } |
3aef83e0 | 210 | return bio_write_page(offset, src, bio_chain); |
61159a31 RW |
211 | } |
212 | ||
213 | /* | |
214 | * The swap map is a data structure used for keeping track of each page | |
215 | * written to a swap partition. It consists of many swap_map_page | |
216 | * structures that contain each an array of MAP_PAGE_SIZE swap entries. | |
217 | * These structures are stored on the swap and linked together with the | |
218 | * help of the .next_swap member. | |
219 | * | |
220 | * The swap map is created during suspend. The swap map pages are | |
221 | * allocated and populated one at a time, so we only need one memory | |
222 | * page to set up the entire structure. | |
223 | * | |
224 | * During resume we also only need to use one swap_map_page structure | |
225 | * at a time. | |
226 | */ | |
227 | ||
3aef83e0 | 228 | #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) |
61159a31 RW |
229 | |
230 | struct swap_map_page { | |
3aef83e0 RW |
231 | sector_t entries[MAP_PAGE_ENTRIES]; |
232 | sector_t next_swap; | |
61159a31 RW |
233 | }; |
234 | ||
235 | /** | |
236 | * The swap_map_handle structure is used for handling swap in | |
237 | * a file-alike way | |
238 | */ | |
239 | ||
240 | struct swap_map_handle { | |
241 | struct swap_map_page *cur; | |
3aef83e0 | 242 | sector_t cur_swap; |
61159a31 RW |
243 | unsigned int k; |
244 | }; | |
245 | ||
246 | static void release_swap_writer(struct swap_map_handle *handle) | |
247 | { | |
248 | if (handle->cur) | |
249 | free_page((unsigned long)handle->cur); | |
250 | handle->cur = NULL; | |
61159a31 RW |
251 | } |
252 | ||
253 | static int get_swap_writer(struct swap_map_handle *handle) | |
254 | { | |
255 | handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); | |
256 | if (!handle->cur) | |
257 | return -ENOMEM; | |
d1d241cc | 258 | handle->cur_swap = alloc_swapdev_block(root_swap); |
61159a31 RW |
259 | if (!handle->cur_swap) { |
260 | release_swap_writer(handle); | |
261 | return -ENOSPC; | |
262 | } | |
263 | handle->k = 0; | |
264 | return 0; | |
265 | } | |
266 | ||
ab954160 AM |
267 | static int swap_write_page(struct swap_map_handle *handle, void *buf, |
268 | struct bio **bio_chain) | |
269 | { | |
270 | int error = 0; | |
3aef83e0 | 271 | sector_t offset; |
61159a31 RW |
272 | |
273 | if (!handle->cur) | |
274 | return -EINVAL; | |
d1d241cc | 275 | offset = alloc_swapdev_block(root_swap); |
ab954160 | 276 | error = write_page(buf, offset, bio_chain); |
61159a31 RW |
277 | if (error) |
278 | return error; | |
279 | handle->cur->entries[handle->k++] = offset; | |
280 | if (handle->k >= MAP_PAGE_ENTRIES) { | |
ab954160 AM |
281 | error = wait_on_bio_chain(bio_chain); |
282 | if (error) | |
283 | goto out; | |
d1d241cc | 284 | offset = alloc_swapdev_block(root_swap); |
61159a31 RW |
285 | if (!offset) |
286 | return -ENOSPC; | |
287 | handle->cur->next_swap = offset; | |
ab954160 | 288 | error = write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 | 289 | if (error) |
ab954160 | 290 | goto out; |
61159a31 RW |
291 | memset(handle->cur, 0, PAGE_SIZE); |
292 | handle->cur_swap = offset; | |
293 | handle->k = 0; | |
294 | } | |
59a49335 | 295 | out: |
ab954160 | 296 | return error; |
61159a31 RW |
297 | } |
298 | ||
299 | static int flush_swap_writer(struct swap_map_handle *handle) | |
300 | { | |
301 | if (handle->cur && handle->cur_swap) | |
ab954160 | 302 | return write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 RW |
303 | else |
304 | return -EINVAL; | |
305 | } | |
306 | ||
307 | /** | |
308 | * save_image - save the suspend image data | |
309 | */ | |
310 | ||
311 | static int save_image(struct swap_map_handle *handle, | |
312 | struct snapshot_handle *snapshot, | |
3a4f7577 | 313 | unsigned int nr_to_write) |
61159a31 RW |
314 | { |
315 | unsigned int m; | |
316 | int ret; | |
3a4f7577 | 317 | int nr_pages; |
ab954160 AM |
318 | int err2; |
319 | struct bio *bio; | |
3a4f7577 AM |
320 | struct timeval start; |
321 | struct timeval stop; | |
61159a31 | 322 | |
23976728 RW |
323 | printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ", |
324 | nr_to_write); | |
3a4f7577 | 325 | m = nr_to_write / 100; |
61159a31 RW |
326 | if (!m) |
327 | m = 1; | |
328 | nr_pages = 0; | |
ab954160 | 329 | bio = NULL; |
3a4f7577 | 330 | do_gettimeofday(&start); |
4ff277f9 | 331 | while (1) { |
61159a31 | 332 | ret = snapshot_read_next(snapshot, PAGE_SIZE); |
4ff277f9 JS |
333 | if (ret <= 0) |
334 | break; | |
335 | ret = swap_write_page(handle, data_of(*snapshot), &bio); | |
336 | if (ret) | |
337 | break; | |
338 | if (!(nr_pages % m)) | |
339 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
340 | nr_pages++; | |
341 | } | |
ab954160 | 342 | err2 = wait_on_bio_chain(&bio); |
3a4f7577 | 343 | do_gettimeofday(&stop); |
4ff277f9 JS |
344 | if (!ret) |
345 | ret = err2; | |
346 | if (!ret) | |
61159a31 | 347 | printk("\b\b\b\bdone\n"); |
4ff277f9 JS |
348 | else |
349 | printk("\n"); | |
0d3a9abe | 350 | swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); |
4ff277f9 | 351 | return ret; |
61159a31 RW |
352 | } |
353 | ||
354 | /** | |
355 | * enough_swap - Make sure we have enough swap to save the image. | |
356 | * | |
357 | * Returns TRUE or FALSE after checking the total amount of swap | |
358 | * space avaiable from the resume partition. | |
359 | */ | |
360 | ||
361 | static int enough_swap(unsigned int nr_pages) | |
362 | { | |
363 | unsigned int free_swap = count_swap_pages(root_swap, 1); | |
364 | ||
23976728 | 365 | pr_debug("PM: Free swap pages: %u\n", free_swap); |
940864dd | 366 | return free_swap > nr_pages + PAGES_FOR_IO; |
61159a31 RW |
367 | } |
368 | ||
369 | /** | |
370 | * swsusp_write - Write entire image and metadata. | |
a634cc10 | 371 | * @flags: flags to pass to the "boot" kernel in the image header |
61159a31 RW |
372 | * |
373 | * It is important _NOT_ to umount filesystems at this point. We want | |
374 | * them synced (in case something goes wrong) but we DO not want to mark | |
375 | * filesystem clean: it is not. (And it does not matter, if we resume | |
376 | * correctly, we'll mark system clean, anyway.) | |
377 | */ | |
378 | ||
a634cc10 | 379 | int swsusp_write(unsigned int flags) |
61159a31 RW |
380 | { |
381 | struct swap_map_handle handle; | |
382 | struct snapshot_handle snapshot; | |
383 | struct swsusp_info *header; | |
61159a31 RW |
384 | int error; |
385 | ||
3aef83e0 RW |
386 | error = swsusp_swap_check(); |
387 | if (error) { | |
23976728 | 388 | printk(KERN_ERR "PM: Cannot find swap device, try " |
546e0d27 | 389 | "swapon -a.\n"); |
61159a31 RW |
390 | return error; |
391 | } | |
392 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
393 | error = snapshot_read_next(&snapshot, PAGE_SIZE); | |
3aef83e0 RW |
394 | if (error < PAGE_SIZE) { |
395 | if (error >= 0) | |
396 | error = -EFAULT; | |
397 | ||
398 | goto out; | |
399 | } | |
61159a31 RW |
400 | header = (struct swsusp_info *)data_of(snapshot); |
401 | if (!enough_swap(header->pages)) { | |
23976728 | 402 | printk(KERN_ERR "PM: Not enough free swap\n"); |
3aef83e0 RW |
403 | error = -ENOSPC; |
404 | goto out; | |
61159a31 RW |
405 | } |
406 | error = get_swap_writer(&handle); | |
407 | if (!error) { | |
3aef83e0 RW |
408 | sector_t start = handle.cur_swap; |
409 | ||
ab954160 | 410 | error = swap_write_page(&handle, header, NULL); |
712f403a AM |
411 | if (!error) |
412 | error = save_image(&handle, &snapshot, | |
413 | header->pages - 1); | |
3aef83e0 | 414 | |
712f403a AM |
415 | if (!error) { |
416 | flush_swap_writer(&handle); | |
23976728 | 417 | printk(KERN_INFO "PM: S"); |
a634cc10 | 418 | error = mark_swapfiles(start, flags); |
712f403a AM |
419 | printk("|\n"); |
420 | } | |
61159a31 RW |
421 | } |
422 | if (error) | |
d1d241cc RW |
423 | free_all_swap_pages(root_swap); |
424 | ||
61159a31 | 425 | release_swap_writer(&handle); |
59a49335 | 426 | out: |
c2dd0dae | 427 | swsusp_close(FMODE_WRITE); |
61159a31 RW |
428 | return error; |
429 | } | |
430 | ||
61159a31 RW |
431 | /** |
432 | * The following functions allow us to read data using a swap map | |
433 | * in a file-alike way | |
434 | */ | |
435 | ||
436 | static void release_swap_reader(struct swap_map_handle *handle) | |
437 | { | |
438 | if (handle->cur) | |
439 | free_page((unsigned long)handle->cur); | |
440 | handle->cur = NULL; | |
441 | } | |
442 | ||
3aef83e0 | 443 | static int get_swap_reader(struct swap_map_handle *handle, sector_t start) |
61159a31 RW |
444 | { |
445 | int error; | |
446 | ||
3aef83e0 | 447 | if (!start) |
61159a31 | 448 | return -EINVAL; |
3aef83e0 | 449 | |
85949121 | 450 | handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); |
61159a31 RW |
451 | if (!handle->cur) |
452 | return -ENOMEM; | |
3aef83e0 RW |
453 | |
454 | error = bio_read_page(start, handle->cur, NULL); | |
61159a31 RW |
455 | if (error) { |
456 | release_swap_reader(handle); | |
457 | return error; | |
458 | } | |
459 | handle->k = 0; | |
460 | return 0; | |
461 | } | |
462 | ||
546e0d27 AM |
463 | static int swap_read_page(struct swap_map_handle *handle, void *buf, |
464 | struct bio **bio_chain) | |
61159a31 | 465 | { |
3aef83e0 | 466 | sector_t offset; |
61159a31 RW |
467 | int error; |
468 | ||
469 | if (!handle->cur) | |
470 | return -EINVAL; | |
471 | offset = handle->cur->entries[handle->k]; | |
472 | if (!offset) | |
473 | return -EFAULT; | |
546e0d27 | 474 | error = bio_read_page(offset, buf, bio_chain); |
61159a31 RW |
475 | if (error) |
476 | return error; | |
477 | if (++handle->k >= MAP_PAGE_ENTRIES) { | |
546e0d27 | 478 | error = wait_on_bio_chain(bio_chain); |
61159a31 RW |
479 | handle->k = 0; |
480 | offset = handle->cur->next_swap; | |
481 | if (!offset) | |
482 | release_swap_reader(handle); | |
546e0d27 AM |
483 | else if (!error) |
484 | error = bio_read_page(offset, handle->cur, NULL); | |
61159a31 RW |
485 | } |
486 | return error; | |
487 | } | |
488 | ||
489 | /** | |
490 | * load_image - load the image using the swap map handle | |
491 | * @handle and the snapshot handle @snapshot | |
492 | * (assume there are @nr_pages pages to load) | |
493 | */ | |
494 | ||
495 | static int load_image(struct swap_map_handle *handle, | |
496 | struct snapshot_handle *snapshot, | |
546e0d27 | 497 | unsigned int nr_to_read) |
61159a31 RW |
498 | { |
499 | unsigned int m; | |
61159a31 | 500 | int error = 0; |
8c002494 AM |
501 | struct timeval start; |
502 | struct timeval stop; | |
546e0d27 AM |
503 | struct bio *bio; |
504 | int err2; | |
505 | unsigned nr_pages; | |
61159a31 | 506 | |
23976728 RW |
507 | printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", |
508 | nr_to_read); | |
546e0d27 | 509 | m = nr_to_read / 100; |
61159a31 RW |
510 | if (!m) |
511 | m = 1; | |
512 | nr_pages = 0; | |
546e0d27 | 513 | bio = NULL; |
8c002494 | 514 | do_gettimeofday(&start); |
546e0d27 AM |
515 | for ( ; ; ) { |
516 | error = snapshot_write_next(snapshot, PAGE_SIZE); | |
517 | if (error <= 0) | |
518 | break; | |
519 | error = swap_read_page(handle, data_of(*snapshot), &bio); | |
520 | if (error) | |
521 | break; | |
522 | if (snapshot->sync_read) | |
523 | error = wait_on_bio_chain(&bio); | |
524 | if (error) | |
525 | break; | |
526 | if (!(nr_pages % m)) | |
527 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
528 | nr_pages++; | |
529 | } | |
530 | err2 = wait_on_bio_chain(&bio); | |
8c002494 | 531 | do_gettimeofday(&stop); |
546e0d27 AM |
532 | if (!error) |
533 | error = err2; | |
e655a250 | 534 | if (!error) { |
61159a31 | 535 | printk("\b\b\b\bdone\n"); |
8357376d | 536 | snapshot_write_finalize(snapshot); |
e655a250 CK |
537 | if (!snapshot_image_loaded(snapshot)) |
538 | error = -ENODATA; | |
539 | } | |
0d3a9abe | 540 | swsusp_show_speed(&start, &stop, nr_to_read, "Read"); |
61159a31 RW |
541 | return error; |
542 | } | |
543 | ||
a634cc10 RW |
544 | /** |
545 | * swsusp_read - read the hibernation image. | |
546 | * @flags_p: flags passed by the "frozen" kernel in the image header should | |
547 | * be written into this memeory location | |
548 | */ | |
549 | ||
550 | int swsusp_read(unsigned int *flags_p) | |
61159a31 RW |
551 | { |
552 | int error; | |
553 | struct swap_map_handle handle; | |
554 | struct snapshot_handle snapshot; | |
555 | struct swsusp_info *header; | |
556 | ||
a634cc10 | 557 | *flags_p = swsusp_header->flags; |
61159a31 | 558 | if (IS_ERR(resume_bdev)) { |
23976728 | 559 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
560 | return PTR_ERR(resume_bdev); |
561 | } | |
562 | ||
563 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
564 | error = snapshot_write_next(&snapshot, PAGE_SIZE); | |
565 | if (error < PAGE_SIZE) | |
566 | return error < 0 ? error : -EFAULT; | |
567 | header = (struct swsusp_info *)data_of(snapshot); | |
1b29c164 | 568 | error = get_swap_reader(&handle, swsusp_header->image); |
61159a31 | 569 | if (!error) |
546e0d27 | 570 | error = swap_read_page(&handle, header, NULL); |
61159a31 RW |
571 | if (!error) |
572 | error = load_image(&handle, &snapshot, header->pages - 1); | |
573 | release_swap_reader(&handle); | |
574 | ||
61159a31 | 575 | if (!error) |
23976728 | 576 | pr_debug("PM: Image successfully loaded\n"); |
61159a31 | 577 | else |
23976728 | 578 | pr_debug("PM: Error %d resuming\n", error); |
61159a31 RW |
579 | return error; |
580 | } | |
581 | ||
582 | /** | |
583 | * swsusp_check - Check for swsusp signature in the resume device | |
584 | */ | |
585 | ||
586 | int swsusp_check(void) | |
587 | { | |
588 | int error; | |
589 | ||
590 | resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); | |
591 | if (!IS_ERR(resume_bdev)) { | |
592 | set_blocksize(resume_bdev, PAGE_SIZE); | |
6373da1f | 593 | memset(swsusp_header, 0, PAGE_SIZE); |
9a154d9d | 594 | error = bio_read_page(swsusp_resume_block, |
1b29c164 | 595 | swsusp_header, NULL); |
9a154d9d | 596 | if (error) |
76b57e61 | 597 | goto put; |
9a154d9d | 598 | |
1b29c164 VG |
599 | if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) { |
600 | memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); | |
61159a31 | 601 | /* Reset swap signature now */ |
9a154d9d | 602 | error = bio_write_page(swsusp_resume_block, |
1b29c164 | 603 | swsusp_header, NULL); |
61159a31 | 604 | } else { |
76b57e61 | 605 | error = -EINVAL; |
61159a31 | 606 | } |
76b57e61 JS |
607 | |
608 | put: | |
61159a31 | 609 | if (error) |
9a1c3542 | 610 | blkdev_put(resume_bdev, FMODE_READ); |
61159a31 | 611 | else |
23976728 | 612 | pr_debug("PM: Signature found, resuming\n"); |
61159a31 RW |
613 | } else { |
614 | error = PTR_ERR(resume_bdev); | |
615 | } | |
616 | ||
617 | if (error) | |
23976728 | 618 | pr_debug("PM: Error %d checking image file\n", error); |
61159a31 RW |
619 | |
620 | return error; | |
621 | } | |
622 | ||
623 | /** | |
624 | * swsusp_close - close swap device. | |
625 | */ | |
626 | ||
c2dd0dae | 627 | void swsusp_close(fmode_t mode) |
61159a31 RW |
628 | { |
629 | if (IS_ERR(resume_bdev)) { | |
23976728 | 630 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
631 | return; |
632 | } | |
633 | ||
50c396d3 | 634 | blkdev_put(resume_bdev, mode); |
61159a31 | 635 | } |
1b29c164 VG |
636 | |
637 | static int swsusp_header_init(void) | |
638 | { | |
639 | swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); | |
640 | if (!swsusp_header) | |
641 | panic("Could not allocate memory for swsusp_header\n"); | |
642 | return 0; | |
643 | } | |
644 | ||
645 | core_initcall(swsusp_header_init); |