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> | |
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 | ||
31 | extern char resume_file[]; | |
32 | ||
33 | #define SWSUSP_SIG "S1SUSPEND" | |
34 | ||
1b29c164 | 35 | struct swsusp_header { |
a634cc10 | 36 | char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; |
3aef83e0 | 37 | sector_t image; |
a634cc10 | 38 | unsigned int flags; /* Flags to pass to the "boot" kernel */ |
61159a31 RW |
39 | char orig_sig[10]; |
40 | char sig[10]; | |
1b29c164 VG |
41 | } __attribute__((packed)); |
42 | ||
43 | static struct swsusp_header *swsusp_header; | |
61159a31 RW |
44 | |
45 | /* | |
3fc6b34f | 46 | * General things |
61159a31 RW |
47 | */ |
48 | ||
49 | static unsigned short root_swap = 0xffff; | |
3fc6b34f RW |
50 | static struct block_device *resume_bdev; |
51 | ||
52 | /** | |
53 | * submit - submit BIO request. | |
54 | * @rw: READ or WRITE. | |
55 | * @off physical offset of page. | |
56 | * @page: page we're reading or writing. | |
57 | * @bio_chain: list of pending biod (for async reading) | |
58 | * | |
59 | * Straight from the textbook - allocate and initialize the bio. | |
60 | * If we're reading, make sure the page is marked as dirty. | |
61 | * Then submit it and, if @bio_chain == NULL, wait. | |
62 | */ | |
63 | static int submit(int rw, pgoff_t page_off, struct page *page, | |
64 | struct bio **bio_chain) | |
65 | { | |
66 | struct bio *bio; | |
67 | ||
85949121 | 68 | bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1); |
3fc6b34f RW |
69 | if (!bio) |
70 | return -ENOMEM; | |
71 | bio->bi_sector = page_off * (PAGE_SIZE >> 9); | |
72 | bio->bi_bdev = resume_bdev; | |
73 | bio->bi_end_io = end_swap_bio_read; | |
74 | ||
75 | if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { | |
76 | printk("swsusp: ERROR: adding page to bio at %ld\n", page_off); | |
77 | bio_put(bio); | |
78 | return -EFAULT; | |
79 | } | |
80 | ||
81 | lock_page(page); | |
82 | bio_get(bio); | |
83 | ||
84 | if (bio_chain == NULL) { | |
85 | submit_bio(rw | (1 << BIO_RW_SYNC), bio); | |
86 | wait_on_page_locked(page); | |
87 | if (rw == READ) | |
88 | bio_set_pages_dirty(bio); | |
89 | bio_put(bio); | |
90 | } else { | |
91 | if (rw == READ) | |
92 | get_page(page); /* These pages are freed later */ | |
93 | bio->bi_private = *bio_chain; | |
94 | *bio_chain = bio; | |
95 | submit_bio(rw | (1 << BIO_RW_SYNC), bio); | |
96 | } | |
97 | return 0; | |
98 | } | |
99 | ||
100 | static int bio_read_page(pgoff_t page_off, void *addr, struct bio **bio_chain) | |
101 | { | |
102 | return submit(READ, page_off, virt_to_page(addr), bio_chain); | |
103 | } | |
104 | ||
3aef83e0 | 105 | static int bio_write_page(pgoff_t page_off, void *addr, struct bio **bio_chain) |
3fc6b34f | 106 | { |
3aef83e0 | 107 | return submit(WRITE, page_off, virt_to_page(addr), bio_chain); |
3fc6b34f RW |
108 | } |
109 | ||
110 | static int wait_on_bio_chain(struct bio **bio_chain) | |
111 | { | |
112 | struct bio *bio; | |
113 | struct bio *next_bio; | |
114 | int ret = 0; | |
115 | ||
116 | if (bio_chain == NULL) | |
117 | return 0; | |
118 | ||
119 | bio = *bio_chain; | |
120 | if (bio == NULL) | |
121 | return 0; | |
122 | while (bio) { | |
123 | struct page *page; | |
124 | ||
125 | next_bio = bio->bi_private; | |
126 | page = bio->bi_io_vec[0].bv_page; | |
127 | wait_on_page_locked(page); | |
128 | if (!PageUptodate(page) || PageError(page)) | |
129 | ret = -EIO; | |
130 | put_page(page); | |
131 | bio_put(bio); | |
132 | bio = next_bio; | |
133 | } | |
134 | *bio_chain = NULL; | |
135 | return ret; | |
136 | } | |
137 | ||
3fc6b34f RW |
138 | /* |
139 | * Saving part | |
140 | */ | |
61159a31 | 141 | |
a634cc10 | 142 | static int mark_swapfiles(sector_t start, unsigned int flags) |
61159a31 RW |
143 | { |
144 | int error; | |
145 | ||
1b29c164 VG |
146 | bio_read_page(swsusp_resume_block, swsusp_header, NULL); |
147 | if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || | |
148 | !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { | |
149 | memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); | |
150 | memcpy(swsusp_header->sig,SWSUSP_SIG, 10); | |
151 | swsusp_header->image = start; | |
a634cc10 | 152 | swsusp_header->flags = flags; |
9a154d9d | 153 | error = bio_write_page(swsusp_resume_block, |
1b29c164 | 154 | swsusp_header, NULL); |
61159a31 | 155 | } else { |
3aef83e0 | 156 | printk(KERN_ERR "swsusp: Swap header not found!\n"); |
61159a31 RW |
157 | error = -ENODEV; |
158 | } | |
159 | return error; | |
160 | } | |
161 | ||
162 | /** | |
163 | * swsusp_swap_check - check if the resume device is a swap device | |
164 | * and get its index (if so) | |
165 | */ | |
166 | ||
167 | static int swsusp_swap_check(void) /* This is called before saving image */ | |
168 | { | |
3aef83e0 RW |
169 | int res; |
170 | ||
7bf23687 RW |
171 | res = swap_type_of(swsusp_resume_device, swsusp_resume_block, |
172 | &resume_bdev); | |
3aef83e0 RW |
173 | if (res < 0) |
174 | return res; | |
175 | ||
176 | root_swap = res; | |
7bf23687 RW |
177 | res = blkdev_get(resume_bdev, FMODE_WRITE, O_RDWR); |
178 | if (res) | |
179 | return res; | |
3aef83e0 RW |
180 | |
181 | res = set_blocksize(resume_bdev, PAGE_SIZE); | |
182 | if (res < 0) | |
183 | blkdev_put(resume_bdev); | |
61159a31 | 184 | |
61159a31 RW |
185 | return res; |
186 | } | |
187 | ||
188 | /** | |
189 | * write_page - Write one page to given swap location. | |
190 | * @buf: Address we're writing. | |
191 | * @offset: Offset of the swap page we're writing to. | |
ab954160 | 192 | * @bio_chain: Link the next write BIO here |
61159a31 RW |
193 | */ |
194 | ||
3aef83e0 | 195 | static int write_page(void *buf, sector_t offset, struct bio **bio_chain) |
61159a31 | 196 | { |
3aef83e0 RW |
197 | void *src; |
198 | ||
199 | if (!offset) | |
200 | return -ENOSPC; | |
201 | ||
202 | if (bio_chain) { | |
85949121 | 203 | src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); |
3aef83e0 RW |
204 | if (src) { |
205 | memcpy(src, buf, PAGE_SIZE); | |
206 | } else { | |
207 | WARN_ON_ONCE(1); | |
208 | bio_chain = NULL; /* Go synchronous */ | |
209 | src = buf; | |
ab954160 | 210 | } |
3aef83e0 RW |
211 | } else { |
212 | src = buf; | |
61159a31 | 213 | } |
3aef83e0 | 214 | return bio_write_page(offset, src, bio_chain); |
61159a31 RW |
215 | } |
216 | ||
217 | /* | |
218 | * The swap map is a data structure used for keeping track of each page | |
219 | * written to a swap partition. It consists of many swap_map_page | |
220 | * structures that contain each an array of MAP_PAGE_SIZE swap entries. | |
221 | * These structures are stored on the swap and linked together with the | |
222 | * help of the .next_swap member. | |
223 | * | |
224 | * The swap map is created during suspend. The swap map pages are | |
225 | * allocated and populated one at a time, so we only need one memory | |
226 | * page to set up the entire structure. | |
227 | * | |
228 | * During resume we also only need to use one swap_map_page structure | |
229 | * at a time. | |
230 | */ | |
231 | ||
3aef83e0 | 232 | #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) |
61159a31 RW |
233 | |
234 | struct swap_map_page { | |
3aef83e0 RW |
235 | sector_t entries[MAP_PAGE_ENTRIES]; |
236 | sector_t next_swap; | |
61159a31 RW |
237 | }; |
238 | ||
239 | /** | |
240 | * The swap_map_handle structure is used for handling swap in | |
241 | * a file-alike way | |
242 | */ | |
243 | ||
244 | struct swap_map_handle { | |
245 | struct swap_map_page *cur; | |
3aef83e0 | 246 | sector_t cur_swap; |
61159a31 RW |
247 | unsigned int k; |
248 | }; | |
249 | ||
250 | static void release_swap_writer(struct swap_map_handle *handle) | |
251 | { | |
252 | if (handle->cur) | |
253 | free_page((unsigned long)handle->cur); | |
254 | handle->cur = NULL; | |
61159a31 RW |
255 | } |
256 | ||
257 | static int get_swap_writer(struct swap_map_handle *handle) | |
258 | { | |
259 | handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); | |
260 | if (!handle->cur) | |
261 | return -ENOMEM; | |
d1d241cc | 262 | handle->cur_swap = alloc_swapdev_block(root_swap); |
61159a31 RW |
263 | if (!handle->cur_swap) { |
264 | release_swap_writer(handle); | |
265 | return -ENOSPC; | |
266 | } | |
267 | handle->k = 0; | |
268 | return 0; | |
269 | } | |
270 | ||
ab954160 AM |
271 | static int swap_write_page(struct swap_map_handle *handle, void *buf, |
272 | struct bio **bio_chain) | |
273 | { | |
274 | int error = 0; | |
3aef83e0 | 275 | sector_t offset; |
61159a31 RW |
276 | |
277 | if (!handle->cur) | |
278 | return -EINVAL; | |
d1d241cc | 279 | offset = alloc_swapdev_block(root_swap); |
ab954160 | 280 | error = write_page(buf, offset, bio_chain); |
61159a31 RW |
281 | if (error) |
282 | return error; | |
283 | handle->cur->entries[handle->k++] = offset; | |
284 | if (handle->k >= MAP_PAGE_ENTRIES) { | |
ab954160 AM |
285 | error = wait_on_bio_chain(bio_chain); |
286 | if (error) | |
287 | goto out; | |
d1d241cc | 288 | offset = alloc_swapdev_block(root_swap); |
61159a31 RW |
289 | if (!offset) |
290 | return -ENOSPC; | |
291 | handle->cur->next_swap = offset; | |
ab954160 | 292 | error = write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 | 293 | if (error) |
ab954160 | 294 | goto out; |
61159a31 RW |
295 | memset(handle->cur, 0, PAGE_SIZE); |
296 | handle->cur_swap = offset; | |
297 | handle->k = 0; | |
298 | } | |
59a49335 | 299 | out: |
ab954160 | 300 | return error; |
61159a31 RW |
301 | } |
302 | ||
303 | static int flush_swap_writer(struct swap_map_handle *handle) | |
304 | { | |
305 | if (handle->cur && handle->cur_swap) | |
ab954160 | 306 | return write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 RW |
307 | else |
308 | return -EINVAL; | |
309 | } | |
310 | ||
311 | /** | |
312 | * save_image - save the suspend image data | |
313 | */ | |
314 | ||
315 | static int save_image(struct swap_map_handle *handle, | |
316 | struct snapshot_handle *snapshot, | |
3a4f7577 | 317 | unsigned int nr_to_write) |
61159a31 RW |
318 | { |
319 | unsigned int m; | |
320 | int ret; | |
321 | int error = 0; | |
3a4f7577 | 322 | int nr_pages; |
ab954160 AM |
323 | int err2; |
324 | struct bio *bio; | |
3a4f7577 AM |
325 | struct timeval start; |
326 | struct timeval stop; | |
61159a31 | 327 | |
3a4f7577 AM |
328 | printk("Saving image data pages (%u pages) ... ", nr_to_write); |
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 | ||
368 | pr_debug("swsusp: 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) { | |
546e0d27 AM |
391 | printk(KERN_ERR "swsusp: Cannot find swap device, try " |
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)) { | |
405 | printk(KERN_ERR "swsusp: 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); | |
420 | printk("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 | |
546e0d27 AM |
510 | printk("Loading image data pages (%u pages) ... ", nr_to_read); |
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 RW |
560 | if (IS_ERR(resume_bdev)) { |
561 | pr_debug("swsusp: block device not initialised\n"); | |
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) | |
580 | pr_debug("swsusp: Reading resume file was successful\n"); | |
581 | else | |
582 | pr_debug("swsusp: Error %d resuming\n", error); | |
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 | |
614 | pr_debug("swsusp: Signature found, resuming\n"); | |
615 | } else { | |
616 | error = PTR_ERR(resume_bdev); | |
617 | } | |
618 | ||
619 | if (error) | |
620 | pr_debug("swsusp: Error %d check for resume file\n", error); | |
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)) { | |
632 | pr_debug("swsusp: block device not initialised\n"); | |
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); |