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> | |
5a0e3ad6 | 26 | #include <linux/slab.h> |
61159a31 RW |
27 | |
28 | #include "power.h" | |
29 | ||
61159a31 RW |
30 | #define SWSUSP_SIG "S1SUSPEND" |
31 | ||
51fb352b JS |
32 | /* |
33 | * The swap map is a data structure used for keeping track of each page | |
34 | * written to a swap partition. It consists of many swap_map_page | |
35 | * structures that contain each an array of MAP_PAGE_SIZE swap entries. | |
36 | * These structures are stored on the swap and linked together with the | |
37 | * help of the .next_swap member. | |
38 | * | |
39 | * The swap map is created during suspend. The swap map pages are | |
40 | * allocated and populated one at a time, so we only need one memory | |
41 | * page to set up the entire structure. | |
42 | * | |
43 | * During resume we also only need to use one swap_map_page structure | |
44 | * at a time. | |
45 | */ | |
46 | ||
47 | #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) | |
48 | ||
49 | struct swap_map_page { | |
50 | sector_t entries[MAP_PAGE_ENTRIES]; | |
51 | sector_t next_swap; | |
52 | }; | |
53 | ||
54 | /** | |
55 | * The swap_map_handle structure is used for handling swap in | |
56 | * a file-alike way | |
57 | */ | |
58 | ||
59 | struct swap_map_handle { | |
60 | struct swap_map_page *cur; | |
61 | sector_t cur_swap; | |
62 | sector_t first_sector; | |
63 | unsigned int k; | |
64 | }; | |
65 | ||
1b29c164 | 66 | struct swsusp_header { |
a634cc10 | 67 | char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int)]; |
3aef83e0 | 68 | sector_t image; |
a634cc10 | 69 | unsigned int flags; /* Flags to pass to the "boot" kernel */ |
61159a31 RW |
70 | char orig_sig[10]; |
71 | char sig[10]; | |
1b29c164 VG |
72 | } __attribute__((packed)); |
73 | ||
74 | static struct swsusp_header *swsusp_header; | |
61159a31 | 75 | |
0414f2ec NC |
76 | /** |
77 | * The following functions are used for tracing the allocated | |
78 | * swap pages, so that they can be freed in case of an error. | |
79 | */ | |
80 | ||
81 | struct swsusp_extent { | |
82 | struct rb_node node; | |
83 | unsigned long start; | |
84 | unsigned long end; | |
85 | }; | |
86 | ||
87 | static struct rb_root swsusp_extents = RB_ROOT; | |
88 | ||
89 | static int swsusp_extents_insert(unsigned long swap_offset) | |
90 | { | |
91 | struct rb_node **new = &(swsusp_extents.rb_node); | |
92 | struct rb_node *parent = NULL; | |
93 | struct swsusp_extent *ext; | |
94 | ||
95 | /* Figure out where to put the new node */ | |
96 | while (*new) { | |
97 | ext = container_of(*new, struct swsusp_extent, node); | |
98 | parent = *new; | |
99 | if (swap_offset < ext->start) { | |
100 | /* Try to merge */ | |
101 | if (swap_offset == ext->start - 1) { | |
102 | ext->start--; | |
103 | return 0; | |
104 | } | |
105 | new = &((*new)->rb_left); | |
106 | } else if (swap_offset > ext->end) { | |
107 | /* Try to merge */ | |
108 | if (swap_offset == ext->end + 1) { | |
109 | ext->end++; | |
110 | return 0; | |
111 | } | |
112 | new = &((*new)->rb_right); | |
113 | } else { | |
114 | /* It already is in the tree */ | |
115 | return -EINVAL; | |
116 | } | |
117 | } | |
118 | /* Add the new node and rebalance the tree. */ | |
119 | ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); | |
120 | if (!ext) | |
121 | return -ENOMEM; | |
122 | ||
123 | ext->start = swap_offset; | |
124 | ext->end = swap_offset; | |
125 | rb_link_node(&ext->node, parent, new); | |
126 | rb_insert_color(&ext->node, &swsusp_extents); | |
127 | return 0; | |
128 | } | |
129 | ||
130 | /** | |
131 | * alloc_swapdev_block - allocate a swap page and register that it has | |
132 | * been allocated, so that it can be freed in case of an error. | |
133 | */ | |
134 | ||
135 | sector_t alloc_swapdev_block(int swap) | |
136 | { | |
137 | unsigned long offset; | |
138 | ||
139 | offset = swp_offset(get_swap_page_of_type(swap)); | |
140 | if (offset) { | |
141 | if (swsusp_extents_insert(offset)) | |
142 | swap_free(swp_entry(swap, offset)); | |
143 | else | |
144 | return swapdev_block(swap, offset); | |
145 | } | |
146 | return 0; | |
147 | } | |
148 | ||
149 | /** | |
150 | * free_all_swap_pages - free swap pages allocated for saving image data. | |
151 | * It also frees the extents used to register which swap entres had been | |
152 | * allocated. | |
153 | */ | |
154 | ||
155 | void free_all_swap_pages(int swap) | |
156 | { | |
157 | struct rb_node *node; | |
158 | ||
159 | while ((node = swsusp_extents.rb_node)) { | |
160 | struct swsusp_extent *ext; | |
161 | unsigned long offset; | |
162 | ||
163 | ext = container_of(node, struct swsusp_extent, node); | |
164 | rb_erase(node, &swsusp_extents); | |
165 | for (offset = ext->start; offset <= ext->end; offset++) | |
166 | swap_free(swp_entry(swap, offset)); | |
167 | ||
168 | kfree(ext); | |
169 | } | |
170 | } | |
171 | ||
172 | int swsusp_swap_in_use(void) | |
173 | { | |
174 | return (swsusp_extents.rb_node != NULL); | |
175 | } | |
176 | ||
61159a31 | 177 | /* |
3fc6b34f | 178 | * General things |
61159a31 RW |
179 | */ |
180 | ||
181 | static unsigned short root_swap = 0xffff; | |
8a0d613f | 182 | struct block_device *hib_resume_bdev; |
3fc6b34f | 183 | |
3fc6b34f RW |
184 | /* |
185 | * Saving part | |
186 | */ | |
61159a31 | 187 | |
51fb352b | 188 | static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) |
61159a31 RW |
189 | { |
190 | int error; | |
191 | ||
8a0d613f | 192 | hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); |
1b29c164 VG |
193 | if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || |
194 | !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { | |
195 | memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); | |
196 | memcpy(swsusp_header->sig,SWSUSP_SIG, 10); | |
51fb352b | 197 | swsusp_header->image = handle->first_sector; |
a634cc10 | 198 | swsusp_header->flags = flags; |
8a0d613f | 199 | error = hib_bio_write_page(swsusp_resume_block, |
1b29c164 | 200 | swsusp_header, NULL); |
61159a31 | 201 | } else { |
23976728 | 202 | printk(KERN_ERR "PM: Swap header not found!\n"); |
61159a31 RW |
203 | error = -ENODEV; |
204 | } | |
205 | return error; | |
206 | } | |
207 | ||
208 | /** | |
209 | * swsusp_swap_check - check if the resume device is a swap device | |
210 | * and get its index (if so) | |
211 | */ | |
212 | ||
213 | static int swsusp_swap_check(void) /* This is called before saving image */ | |
214 | { | |
3aef83e0 RW |
215 | int res; |
216 | ||
7bf23687 | 217 | res = swap_type_of(swsusp_resume_device, swsusp_resume_block, |
8a0d613f | 218 | &hib_resume_bdev); |
3aef83e0 RW |
219 | if (res < 0) |
220 | return res; | |
221 | ||
222 | root_swap = res; | |
8a0d613f | 223 | res = blkdev_get(hib_resume_bdev, FMODE_WRITE); |
7bf23687 RW |
224 | if (res) |
225 | return res; | |
3aef83e0 | 226 | |
8a0d613f | 227 | res = set_blocksize(hib_resume_bdev, PAGE_SIZE); |
3aef83e0 | 228 | if (res < 0) |
8a0d613f | 229 | blkdev_put(hib_resume_bdev, FMODE_WRITE); |
61159a31 | 230 | |
61159a31 RW |
231 | return res; |
232 | } | |
233 | ||
234 | /** | |
235 | * write_page - Write one page to given swap location. | |
236 | * @buf: Address we're writing. | |
237 | * @offset: Offset of the swap page we're writing to. | |
ab954160 | 238 | * @bio_chain: Link the next write BIO here |
61159a31 RW |
239 | */ |
240 | ||
3aef83e0 | 241 | static int write_page(void *buf, sector_t offset, struct bio **bio_chain) |
61159a31 | 242 | { |
3aef83e0 RW |
243 | void *src; |
244 | ||
245 | if (!offset) | |
246 | return -ENOSPC; | |
247 | ||
248 | if (bio_chain) { | |
85949121 | 249 | src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); |
3aef83e0 RW |
250 | if (src) { |
251 | memcpy(src, buf, PAGE_SIZE); | |
252 | } else { | |
253 | WARN_ON_ONCE(1); | |
254 | bio_chain = NULL; /* Go synchronous */ | |
255 | src = buf; | |
ab954160 | 256 | } |
3aef83e0 RW |
257 | } else { |
258 | src = buf; | |
61159a31 | 259 | } |
8a0d613f | 260 | return hib_bio_write_page(offset, src, bio_chain); |
61159a31 RW |
261 | } |
262 | ||
61159a31 RW |
263 | static void release_swap_writer(struct swap_map_handle *handle) |
264 | { | |
265 | if (handle->cur) | |
266 | free_page((unsigned long)handle->cur); | |
267 | handle->cur = NULL; | |
61159a31 RW |
268 | } |
269 | ||
270 | static int get_swap_writer(struct swap_map_handle *handle) | |
271 | { | |
272 | handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); | |
273 | if (!handle->cur) | |
274 | return -ENOMEM; | |
d1d241cc | 275 | handle->cur_swap = alloc_swapdev_block(root_swap); |
61159a31 RW |
276 | if (!handle->cur_swap) { |
277 | release_swap_writer(handle); | |
278 | return -ENOSPC; | |
279 | } | |
280 | handle->k = 0; | |
51fb352b | 281 | handle->first_sector = handle->cur_swap; |
61159a31 RW |
282 | return 0; |
283 | } | |
284 | ||
ab954160 AM |
285 | static int swap_write_page(struct swap_map_handle *handle, void *buf, |
286 | struct bio **bio_chain) | |
287 | { | |
288 | int error = 0; | |
3aef83e0 | 289 | sector_t offset; |
61159a31 RW |
290 | |
291 | if (!handle->cur) | |
292 | return -EINVAL; | |
d1d241cc | 293 | offset = alloc_swapdev_block(root_swap); |
ab954160 | 294 | error = write_page(buf, offset, bio_chain); |
61159a31 RW |
295 | if (error) |
296 | return error; | |
297 | handle->cur->entries[handle->k++] = offset; | |
298 | if (handle->k >= MAP_PAGE_ENTRIES) { | |
8a0d613f | 299 | error = hib_wait_on_bio_chain(bio_chain); |
ab954160 AM |
300 | if (error) |
301 | goto out; | |
d1d241cc | 302 | offset = alloc_swapdev_block(root_swap); |
61159a31 RW |
303 | if (!offset) |
304 | return -ENOSPC; | |
305 | handle->cur->next_swap = offset; | |
ab954160 | 306 | error = write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 | 307 | if (error) |
ab954160 | 308 | goto out; |
61159a31 RW |
309 | memset(handle->cur, 0, PAGE_SIZE); |
310 | handle->cur_swap = offset; | |
311 | handle->k = 0; | |
312 | } | |
59a49335 | 313 | out: |
ab954160 | 314 | return error; |
61159a31 RW |
315 | } |
316 | ||
317 | static int flush_swap_writer(struct swap_map_handle *handle) | |
318 | { | |
319 | if (handle->cur && handle->cur_swap) | |
ab954160 | 320 | return write_page(handle->cur, handle->cur_swap, NULL); |
61159a31 RW |
321 | else |
322 | return -EINVAL; | |
323 | } | |
324 | ||
325 | /** | |
326 | * save_image - save the suspend image data | |
327 | */ | |
328 | ||
329 | static int save_image(struct swap_map_handle *handle, | |
330 | struct snapshot_handle *snapshot, | |
3a4f7577 | 331 | unsigned int nr_to_write) |
61159a31 RW |
332 | { |
333 | unsigned int m; | |
334 | int ret; | |
3a4f7577 | 335 | int nr_pages; |
ab954160 AM |
336 | int err2; |
337 | struct bio *bio; | |
3a4f7577 AM |
338 | struct timeval start; |
339 | struct timeval stop; | |
61159a31 | 340 | |
23976728 RW |
341 | printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ", |
342 | nr_to_write); | |
3a4f7577 | 343 | m = nr_to_write / 100; |
61159a31 RW |
344 | if (!m) |
345 | m = 1; | |
346 | nr_pages = 0; | |
ab954160 | 347 | bio = NULL; |
3a4f7577 | 348 | do_gettimeofday(&start); |
4ff277f9 | 349 | while (1) { |
d3c1b24c | 350 | ret = snapshot_read_next(snapshot); |
4ff277f9 JS |
351 | if (ret <= 0) |
352 | break; | |
353 | ret = swap_write_page(handle, data_of(*snapshot), &bio); | |
354 | if (ret) | |
355 | break; | |
356 | if (!(nr_pages % m)) | |
66d0ae4d | 357 | printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m); |
4ff277f9 JS |
358 | nr_pages++; |
359 | } | |
8a0d613f | 360 | err2 = hib_wait_on_bio_chain(&bio); |
3a4f7577 | 361 | do_gettimeofday(&stop); |
4ff277f9 JS |
362 | if (!ret) |
363 | ret = err2; | |
364 | if (!ret) | |
66d0ae4d | 365 | printk(KERN_CONT "\b\b\b\bdone\n"); |
4ff277f9 | 366 | else |
66d0ae4d | 367 | printk(KERN_CONT "\n"); |
0d3a9abe | 368 | swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); |
4ff277f9 | 369 | return ret; |
61159a31 RW |
370 | } |
371 | ||
372 | /** | |
373 | * enough_swap - Make sure we have enough swap to save the image. | |
374 | * | |
375 | * Returns TRUE or FALSE after checking the total amount of swap | |
376 | * space avaiable from the resume partition. | |
377 | */ | |
378 | ||
379 | static int enough_swap(unsigned int nr_pages) | |
380 | { | |
381 | unsigned int free_swap = count_swap_pages(root_swap, 1); | |
382 | ||
23976728 | 383 | pr_debug("PM: Free swap pages: %u\n", free_swap); |
940864dd | 384 | return free_swap > nr_pages + PAGES_FOR_IO; |
61159a31 RW |
385 | } |
386 | ||
387 | /** | |
388 | * swsusp_write - Write entire image and metadata. | |
a634cc10 | 389 | * @flags: flags to pass to the "boot" kernel in the image header |
61159a31 RW |
390 | * |
391 | * It is important _NOT_ to umount filesystems at this point. We want | |
392 | * them synced (in case something goes wrong) but we DO not want to mark | |
393 | * filesystem clean: it is not. (And it does not matter, if we resume | |
394 | * correctly, we'll mark system clean, anyway.) | |
395 | */ | |
396 | ||
a634cc10 | 397 | int swsusp_write(unsigned int flags) |
61159a31 RW |
398 | { |
399 | struct swap_map_handle handle; | |
400 | struct snapshot_handle snapshot; | |
401 | struct swsusp_info *header; | |
61159a31 RW |
402 | int error; |
403 | ||
3aef83e0 RW |
404 | error = swsusp_swap_check(); |
405 | if (error) { | |
23976728 | 406 | printk(KERN_ERR "PM: Cannot find swap device, try " |
546e0d27 | 407 | "swapon -a.\n"); |
61159a31 RW |
408 | return error; |
409 | } | |
410 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
d3c1b24c | 411 | error = snapshot_read_next(&snapshot); |
3aef83e0 RW |
412 | if (error < PAGE_SIZE) { |
413 | if (error >= 0) | |
414 | error = -EFAULT; | |
415 | ||
416 | goto out; | |
417 | } | |
61159a31 RW |
418 | header = (struct swsusp_info *)data_of(snapshot); |
419 | if (!enough_swap(header->pages)) { | |
23976728 | 420 | printk(KERN_ERR "PM: Not enough free swap\n"); |
3aef83e0 RW |
421 | error = -ENOSPC; |
422 | goto out; | |
61159a31 RW |
423 | } |
424 | error = get_swap_writer(&handle); | |
425 | if (!error) { | |
ab954160 | 426 | error = swap_write_page(&handle, header, NULL); |
712f403a AM |
427 | if (!error) |
428 | error = save_image(&handle, &snapshot, | |
429 | header->pages - 1); | |
3aef83e0 | 430 | |
712f403a AM |
431 | if (!error) { |
432 | flush_swap_writer(&handle); | |
23976728 | 433 | printk(KERN_INFO "PM: S"); |
51fb352b | 434 | error = mark_swapfiles(&handle, flags); |
712f403a AM |
435 | printk("|\n"); |
436 | } | |
61159a31 RW |
437 | } |
438 | if (error) | |
d1d241cc RW |
439 | free_all_swap_pages(root_swap); |
440 | ||
61159a31 | 441 | release_swap_writer(&handle); |
59a49335 | 442 | out: |
c2dd0dae | 443 | swsusp_close(FMODE_WRITE); |
61159a31 RW |
444 | return error; |
445 | } | |
446 | ||
61159a31 RW |
447 | /** |
448 | * The following functions allow us to read data using a swap map | |
449 | * in a file-alike way | |
450 | */ | |
451 | ||
452 | static void release_swap_reader(struct swap_map_handle *handle) | |
453 | { | |
454 | if (handle->cur) | |
455 | free_page((unsigned long)handle->cur); | |
456 | handle->cur = NULL; | |
457 | } | |
458 | ||
3aef83e0 | 459 | static int get_swap_reader(struct swap_map_handle *handle, sector_t start) |
61159a31 RW |
460 | { |
461 | int error; | |
462 | ||
3aef83e0 | 463 | if (!start) |
61159a31 | 464 | return -EINVAL; |
3aef83e0 | 465 | |
85949121 | 466 | handle->cur = (struct swap_map_page *)get_zeroed_page(__GFP_WAIT | __GFP_HIGH); |
61159a31 RW |
467 | if (!handle->cur) |
468 | return -ENOMEM; | |
3aef83e0 | 469 | |
8a0d613f | 470 | error = hib_bio_read_page(start, handle->cur, NULL); |
61159a31 RW |
471 | if (error) { |
472 | release_swap_reader(handle); | |
473 | return error; | |
474 | } | |
475 | handle->k = 0; | |
476 | return 0; | |
477 | } | |
478 | ||
546e0d27 AM |
479 | static int swap_read_page(struct swap_map_handle *handle, void *buf, |
480 | struct bio **bio_chain) | |
61159a31 | 481 | { |
3aef83e0 | 482 | sector_t offset; |
61159a31 RW |
483 | int error; |
484 | ||
485 | if (!handle->cur) | |
486 | return -EINVAL; | |
487 | offset = handle->cur->entries[handle->k]; | |
488 | if (!offset) | |
489 | return -EFAULT; | |
8a0d613f | 490 | error = hib_bio_read_page(offset, buf, bio_chain); |
61159a31 RW |
491 | if (error) |
492 | return error; | |
493 | if (++handle->k >= MAP_PAGE_ENTRIES) { | |
8a0d613f | 494 | error = hib_wait_on_bio_chain(bio_chain); |
61159a31 RW |
495 | handle->k = 0; |
496 | offset = handle->cur->next_swap; | |
497 | if (!offset) | |
498 | release_swap_reader(handle); | |
546e0d27 | 499 | else if (!error) |
8a0d613f | 500 | error = hib_bio_read_page(offset, handle->cur, NULL); |
61159a31 RW |
501 | } |
502 | return error; | |
503 | } | |
504 | ||
505 | /** | |
506 | * load_image - load the image using the swap map handle | |
507 | * @handle and the snapshot handle @snapshot | |
508 | * (assume there are @nr_pages pages to load) | |
509 | */ | |
510 | ||
511 | static int load_image(struct swap_map_handle *handle, | |
512 | struct snapshot_handle *snapshot, | |
546e0d27 | 513 | unsigned int nr_to_read) |
61159a31 RW |
514 | { |
515 | unsigned int m; | |
61159a31 | 516 | int error = 0; |
8c002494 AM |
517 | struct timeval start; |
518 | struct timeval stop; | |
546e0d27 AM |
519 | struct bio *bio; |
520 | int err2; | |
521 | unsigned nr_pages; | |
61159a31 | 522 | |
23976728 RW |
523 | printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", |
524 | nr_to_read); | |
546e0d27 | 525 | m = nr_to_read / 100; |
61159a31 RW |
526 | if (!m) |
527 | m = 1; | |
528 | nr_pages = 0; | |
546e0d27 | 529 | bio = NULL; |
8c002494 | 530 | do_gettimeofday(&start); |
546e0d27 | 531 | for ( ; ; ) { |
d3c1b24c | 532 | error = snapshot_write_next(snapshot); |
546e0d27 AM |
533 | if (error <= 0) |
534 | break; | |
535 | error = swap_read_page(handle, data_of(*snapshot), &bio); | |
536 | if (error) | |
537 | break; | |
538 | if (snapshot->sync_read) | |
8a0d613f | 539 | error = hib_wait_on_bio_chain(&bio); |
546e0d27 AM |
540 | if (error) |
541 | break; | |
542 | if (!(nr_pages % m)) | |
543 | printk("\b\b\b\b%3d%%", nr_pages / m); | |
544 | nr_pages++; | |
545 | } | |
8a0d613f | 546 | err2 = hib_wait_on_bio_chain(&bio); |
8c002494 | 547 | do_gettimeofday(&stop); |
546e0d27 AM |
548 | if (!error) |
549 | error = err2; | |
e655a250 | 550 | if (!error) { |
61159a31 | 551 | printk("\b\b\b\bdone\n"); |
8357376d | 552 | snapshot_write_finalize(snapshot); |
e655a250 CK |
553 | if (!snapshot_image_loaded(snapshot)) |
554 | error = -ENODATA; | |
bf9fd67a JS |
555 | } else |
556 | printk("\n"); | |
0d3a9abe | 557 | swsusp_show_speed(&start, &stop, nr_to_read, "Read"); |
61159a31 RW |
558 | return error; |
559 | } | |
560 | ||
a634cc10 RW |
561 | /** |
562 | * swsusp_read - read the hibernation image. | |
563 | * @flags_p: flags passed by the "frozen" kernel in the image header should | |
564 | * be written into this memeory location | |
565 | */ | |
566 | ||
567 | int swsusp_read(unsigned int *flags_p) | |
61159a31 RW |
568 | { |
569 | int error; | |
570 | struct swap_map_handle handle; | |
571 | struct snapshot_handle snapshot; | |
572 | struct swsusp_info *header; | |
573 | ||
a634cc10 | 574 | *flags_p = swsusp_header->flags; |
61159a31 RW |
575 | |
576 | memset(&snapshot, 0, sizeof(struct snapshot_handle)); | |
d3c1b24c | 577 | error = snapshot_write_next(&snapshot); |
61159a31 RW |
578 | if (error < PAGE_SIZE) |
579 | return error < 0 ? error : -EFAULT; | |
580 | header = (struct swsusp_info *)data_of(snapshot); | |
1b29c164 | 581 | error = get_swap_reader(&handle, swsusp_header->image); |
61159a31 | 582 | if (!error) |
546e0d27 | 583 | error = swap_read_page(&handle, header, NULL); |
61159a31 RW |
584 | if (!error) |
585 | error = load_image(&handle, &snapshot, header->pages - 1); | |
586 | release_swap_reader(&handle); | |
587 | ||
61159a31 | 588 | if (!error) |
23976728 | 589 | pr_debug("PM: Image successfully loaded\n"); |
61159a31 | 590 | else |
23976728 | 591 | pr_debug("PM: Error %d resuming\n", error); |
61159a31 RW |
592 | return error; |
593 | } | |
594 | ||
595 | /** | |
596 | * swsusp_check - Check for swsusp signature in the resume device | |
597 | */ | |
598 | ||
599 | int swsusp_check(void) | |
600 | { | |
601 | int error; | |
602 | ||
8a0d613f JS |
603 | hib_resume_bdev = open_by_devnum(swsusp_resume_device, FMODE_READ); |
604 | if (!IS_ERR(hib_resume_bdev)) { | |
605 | set_blocksize(hib_resume_bdev, PAGE_SIZE); | |
6373da1f | 606 | memset(swsusp_header, 0, PAGE_SIZE); |
8a0d613f | 607 | error = hib_bio_read_page(swsusp_resume_block, |
1b29c164 | 608 | swsusp_header, NULL); |
9a154d9d | 609 | if (error) |
76b57e61 | 610 | goto put; |
9a154d9d | 611 | |
1b29c164 VG |
612 | if (!memcmp(SWSUSP_SIG, swsusp_header->sig, 10)) { |
613 | memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); | |
61159a31 | 614 | /* Reset swap signature now */ |
8a0d613f | 615 | error = hib_bio_write_page(swsusp_resume_block, |
1b29c164 | 616 | swsusp_header, NULL); |
61159a31 | 617 | } else { |
76b57e61 | 618 | error = -EINVAL; |
61159a31 | 619 | } |
76b57e61 JS |
620 | |
621 | put: | |
61159a31 | 622 | if (error) |
8a0d613f | 623 | blkdev_put(hib_resume_bdev, FMODE_READ); |
61159a31 | 624 | else |
23976728 | 625 | pr_debug("PM: Signature found, resuming\n"); |
61159a31 | 626 | } else { |
8a0d613f | 627 | error = PTR_ERR(hib_resume_bdev); |
61159a31 RW |
628 | } |
629 | ||
630 | if (error) | |
23976728 | 631 | pr_debug("PM: Error %d checking image file\n", error); |
61159a31 RW |
632 | |
633 | return error; | |
634 | } | |
635 | ||
636 | /** | |
637 | * swsusp_close - close swap device. | |
638 | */ | |
639 | ||
c2dd0dae | 640 | void swsusp_close(fmode_t mode) |
61159a31 | 641 | { |
8a0d613f | 642 | if (IS_ERR(hib_resume_bdev)) { |
23976728 | 643 | pr_debug("PM: Image device not initialised\n"); |
61159a31 RW |
644 | return; |
645 | } | |
646 | ||
8a0d613f | 647 | blkdev_put(hib_resume_bdev, mode); |
61159a31 | 648 | } |
1b29c164 VG |
649 | |
650 | static int swsusp_header_init(void) | |
651 | { | |
652 | swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); | |
653 | if (!swsusp_header) | |
654 | panic("Could not allocate memory for swsusp_header\n"); | |
655 | return 0; | |
656 | } | |
657 | ||
658 | core_initcall(swsusp_header_init); |