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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@ucw.cz>
8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
9 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
10 *
11 * This file is released under the GPLv2.
12 *
13 */
14
15#include <linux/module.h>
16#include <linux/file.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/genhd.h>
20#include <linux/device.h>
21#include <linux/bio.h>
22#include <linux/blkdev.h>
23#include <linux/swap.h>
24#include <linux/swapops.h>
25#include <linux/pm.h>
26#include <linux/slab.h>
27#include <linux/lzo.h>
28#include <linux/vmalloc.h>
29#include <linux/cpumask.h>
30#include <linux/atomic.h>
31#include <linux/kthread.h>
32#include <linux/crc32.h>
33
34#include "power.h"
35
36#define HIBERNATE_SIG "S1SUSPEND"
37
38/*
39 * The swap map is a data structure used for keeping track of each page
40 * written to a swap partition. It consists of many swap_map_page
41 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
42 * These structures are stored on the swap and linked together with the
43 * help of the .next_swap member.
44 *
45 * The swap map is created during suspend. The swap map pages are
46 * allocated and populated one at a time, so we only need one memory
47 * page to set up the entire structure.
48 *
49 * During resume we pick up all swap_map_page structures into a list.
50 */
51
52#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
53
54/*
55 * Number of free pages that are not high.
56 */
57static inline unsigned long low_free_pages(void)
58{
59 return nr_free_pages() - nr_free_highpages();
60}
61
62/*
63 * Number of pages required to be kept free while writing the image. Always
64 * half of all available low pages before the writing starts.
65 */
66static inline unsigned long reqd_free_pages(void)
67{
68 return low_free_pages() / 2;
69}
70
71struct swap_map_page {
72 sector_t entries[MAP_PAGE_ENTRIES];
73 sector_t next_swap;
74};
75
76struct swap_map_page_list {
77 struct swap_map_page *map;
78 struct swap_map_page_list *next;
79};
80
81/**
82 * The swap_map_handle structure is used for handling swap in
83 * a file-alike way
84 */
85
86struct swap_map_handle {
87 struct swap_map_page *cur;
88 struct swap_map_page_list *maps;
89 sector_t cur_swap;
90 sector_t first_sector;
91 unsigned int k;
92 unsigned long reqd_free_pages;
93 u32 crc32;
94};
95
96struct swsusp_header {
97 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
98 sizeof(u32)];
99 u32 crc32;
100 sector_t image;
101 unsigned int flags; /* Flags to pass to the "boot" kernel */
102 char orig_sig[10];
103 char sig[10];
104} __attribute__((packed));
105
106static struct swsusp_header *swsusp_header;
107
108/**
109 * The following functions are used for tracing the allocated
110 * swap pages, so that they can be freed in case of an error.
111 */
112
113struct swsusp_extent {
114 struct rb_node node;
115 unsigned long start;
116 unsigned long end;
117};
118
119static struct rb_root swsusp_extents = RB_ROOT;
120
121static int swsusp_extents_insert(unsigned long swap_offset)
122{
123 struct rb_node **new = &(swsusp_extents.rb_node);
124 struct rb_node *parent = NULL;
125 struct swsusp_extent *ext;
126
127 /* Figure out where to put the new node */
128 while (*new) {
129 ext = container_of(*new, struct swsusp_extent, node);
130 parent = *new;
131 if (swap_offset < ext->start) {
132 /* Try to merge */
133 if (swap_offset == ext->start - 1) {
134 ext->start--;
135 return 0;
136 }
137 new = &((*new)->rb_left);
138 } else if (swap_offset > ext->end) {
139 /* Try to merge */
140 if (swap_offset == ext->end + 1) {
141 ext->end++;
142 return 0;
143 }
144 new = &((*new)->rb_right);
145 } else {
146 /* It already is in the tree */
147 return -EINVAL;
148 }
149 }
150 /* Add the new node and rebalance the tree. */
151 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
152 if (!ext)
153 return -ENOMEM;
154
155 ext->start = swap_offset;
156 ext->end = swap_offset;
157 rb_link_node(&ext->node, parent, new);
158 rb_insert_color(&ext->node, &swsusp_extents);
159 return 0;
160}
161
162/**
163 * alloc_swapdev_block - allocate a swap page and register that it has
164 * been allocated, so that it can be freed in case of an error.
165 */
166
167sector_t alloc_swapdev_block(int swap)
168{
169 unsigned long offset;
170
171 offset = swp_offset(get_swap_page_of_type(swap));
172 if (offset) {
173 if (swsusp_extents_insert(offset))
174 swap_free(swp_entry(swap, offset));
175 else
176 return swapdev_block(swap, offset);
177 }
178 return 0;
179}
180
181/**
182 * free_all_swap_pages - free swap pages allocated for saving image data.
183 * It also frees the extents used to register which swap entries had been
184 * allocated.
185 */
186
187void free_all_swap_pages(int swap)
188{
189 struct rb_node *node;
190
191 while ((node = swsusp_extents.rb_node)) {
192 struct swsusp_extent *ext;
193 unsigned long offset;
194
195 ext = container_of(node, struct swsusp_extent, node);
196 rb_erase(node, &swsusp_extents);
197 for (offset = ext->start; offset <= ext->end; offset++)
198 swap_free(swp_entry(swap, offset));
199
200 kfree(ext);
201 }
202}
203
204int swsusp_swap_in_use(void)
205{
206 return (swsusp_extents.rb_node != NULL);
207}
208
209/*
210 * General things
211 */
212
213static unsigned short root_swap = 0xffff;
214struct block_device *hib_resume_bdev;
215
216/*
217 * Saving part
218 */
219
220static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
221{
222 int error;
223
224 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
225 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
226 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
227 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
228 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
229 swsusp_header->image = handle->first_sector;
230 swsusp_header->flags = flags;
231 if (flags & SF_CRC32_MODE)
232 swsusp_header->crc32 = handle->crc32;
233 error = hib_bio_write_page(swsusp_resume_block,
234 swsusp_header, NULL);
235 } else {
236 printk(KERN_ERR "PM: Swap header not found!\n");
237 error = -ENODEV;
238 }
239 return error;
240}
241
242/**
243 * swsusp_swap_check - check if the resume device is a swap device
244 * and get its index (if so)
245 *
246 * This is called before saving image
247 */
248static int swsusp_swap_check(void)
249{
250 int res;
251
252 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
253 &hib_resume_bdev);
254 if (res < 0)
255 return res;
256
257 root_swap = res;
258 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
259 if (res)
260 return res;
261
262 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
263 if (res < 0)
264 blkdev_put(hib_resume_bdev, FMODE_WRITE);
265
266 return res;
267}
268
269/**
270 * write_page - Write one page to given swap location.
271 * @buf: Address we're writing.
272 * @offset: Offset of the swap page we're writing to.
273 * @bio_chain: Link the next write BIO here
274 */
275
276static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
277{
278 void *src;
279 int ret;
280
281 if (!offset)
282 return -ENOSPC;
283
284 if (bio_chain) {
285 src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
286 __GFP_NORETRY);
287 if (src) {
288 copy_page(src, buf);
289 } else {
290 ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
291 if (ret)
292 return ret;
293 src = (void *)__get_free_page(__GFP_WAIT |
294 __GFP_NOWARN |
295 __GFP_NORETRY);
296 if (src) {
297 copy_page(src, buf);
298 } else {
299 WARN_ON_ONCE(1);
300 bio_chain = NULL; /* Go synchronous */
301 src = buf;
302 }
303 }
304 } else {
305 src = buf;
306 }
307 return hib_bio_write_page(offset, src, bio_chain);
308}
309
310static void release_swap_writer(struct swap_map_handle *handle)
311{
312 if (handle->cur)
313 free_page((unsigned long)handle->cur);
314 handle->cur = NULL;
315}
316
317static int get_swap_writer(struct swap_map_handle *handle)
318{
319 int ret;
320
321 ret = swsusp_swap_check();
322 if (ret) {
323 if (ret != -ENOSPC)
324 printk(KERN_ERR "PM: Cannot find swap device, try "
325 "swapon -a.\n");
326 return ret;
327 }
328 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
329 if (!handle->cur) {
330 ret = -ENOMEM;
331 goto err_close;
332 }
333 handle->cur_swap = alloc_swapdev_block(root_swap);
334 if (!handle->cur_swap) {
335 ret = -ENOSPC;
336 goto err_rel;
337 }
338 handle->k = 0;
339 handle->reqd_free_pages = reqd_free_pages();
340 handle->first_sector = handle->cur_swap;
341 return 0;
342err_rel:
343 release_swap_writer(handle);
344err_close:
345 swsusp_close(FMODE_WRITE);
346 return ret;
347}
348
349static int swap_write_page(struct swap_map_handle *handle, void *buf,
350 struct bio **bio_chain)
351{
352 int error = 0;
353 sector_t offset;
354
355 if (!handle->cur)
356 return -EINVAL;
357 offset = alloc_swapdev_block(root_swap);
358 error = write_page(buf, offset, bio_chain);
359 if (error)
360 return error;
361 handle->cur->entries[handle->k++] = offset;
362 if (handle->k >= MAP_PAGE_ENTRIES) {
363 offset = alloc_swapdev_block(root_swap);
364 if (!offset)
365 return -ENOSPC;
366 handle->cur->next_swap = offset;
367 error = write_page(handle->cur, handle->cur_swap, bio_chain);
368 if (error)
369 goto out;
370 clear_page(handle->cur);
371 handle->cur_swap = offset;
372 handle->k = 0;
373
374 if (bio_chain && low_free_pages() <= handle->reqd_free_pages) {
375 error = hib_wait_on_bio_chain(bio_chain);
376 if (error)
377 goto out;
378 /*
379 * Recalculate the number of required free pages, to
380 * make sure we never take more than half.
381 */
382 handle->reqd_free_pages = reqd_free_pages();
383 }
384 }
385 out:
386 return error;
387}
388
389static int flush_swap_writer(struct swap_map_handle *handle)
390{
391 if (handle->cur && handle->cur_swap)
392 return write_page(handle->cur, handle->cur_swap, NULL);
393 else
394 return -EINVAL;
395}
396
397static int swap_writer_finish(struct swap_map_handle *handle,
398 unsigned int flags, int error)
399{
400 if (!error) {
401 flush_swap_writer(handle);
402 printk(KERN_INFO "PM: S");
403 error = mark_swapfiles(handle, flags);
404 printk("|\n");
405 }
406
407 if (error)
408 free_all_swap_pages(root_swap);
409 release_swap_writer(handle);
410 swsusp_close(FMODE_WRITE);
411
412 return error;
413}
414
415/* We need to remember how much compressed data we need to read. */
416#define LZO_HEADER sizeof(size_t)
417
418/* Number of pages/bytes we'll compress at one time. */
419#define LZO_UNC_PAGES 32
420#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
421
422/* Number of pages/bytes we need for compressed data (worst case). */
423#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
424 LZO_HEADER, PAGE_SIZE)
425#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
426
427/* Maximum number of threads for compression/decompression. */
428#define LZO_THREADS 3
429
430/* Minimum/maximum number of pages for read buffering. */
431#define LZO_MIN_RD_PAGES 1024
432#define LZO_MAX_RD_PAGES 8192
433
434
435/**
436 * save_image - save the suspend image data
437 */
438
439static int save_image(struct swap_map_handle *handle,
440 struct snapshot_handle *snapshot,
441 unsigned int nr_to_write)
442{
443 unsigned int m;
444 int ret;
445 int nr_pages;
446 int err2;
447 struct bio *bio;
448 struct timeval start;
449 struct timeval stop;
450
451 printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ",
452 nr_to_write);
453 m = nr_to_write / 100;
454 if (!m)
455 m = 1;
456 nr_pages = 0;
457 bio = NULL;
458 do_gettimeofday(&start);
459 while (1) {
460 ret = snapshot_read_next(snapshot);
461 if (ret <= 0)
462 break;
463 ret = swap_write_page(handle, data_of(*snapshot), &bio);
464 if (ret)
465 break;
466 if (!(nr_pages % m))
467 printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m);
468 nr_pages++;
469 }
470 err2 = hib_wait_on_bio_chain(&bio);
471 do_gettimeofday(&stop);
472 if (!ret)
473 ret = err2;
474 if (!ret)
475 printk(KERN_CONT "\b\b\b\bdone\n");
476 else
477 printk(KERN_CONT "\n");
478 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
479 return ret;
480}
481
482/**
483 * Structure used for CRC32.
484 */
485struct crc_data {
486 struct task_struct *thr; /* thread */
487 atomic_t ready; /* ready to start flag */
488 atomic_t stop; /* ready to stop flag */
489 unsigned run_threads; /* nr current threads */
490 wait_queue_head_t go; /* start crc update */
491 wait_queue_head_t done; /* crc update done */
492 u32 *crc32; /* points to handle's crc32 */
493 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
494 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
495};
496
497/**
498 * CRC32 update function that runs in its own thread.
499 */
500static int crc32_threadfn(void *data)
501{
502 struct crc_data *d = data;
503 unsigned i;
504
505 while (1) {
506 wait_event(d->go, atomic_read(&d->ready) ||
507 kthread_should_stop());
508 if (kthread_should_stop()) {
509 d->thr = NULL;
510 atomic_set(&d->stop, 1);
511 wake_up(&d->done);
512 break;
513 }
514 atomic_set(&d->ready, 0);
515
516 for (i = 0; i < d->run_threads; i++)
517 *d->crc32 = crc32_le(*d->crc32,
518 d->unc[i], *d->unc_len[i]);
519 atomic_set(&d->stop, 1);
520 wake_up(&d->done);
521 }
522 return 0;
523}
524/**
525 * Structure used for LZO data compression.
526 */
527struct cmp_data {
528 struct task_struct *thr; /* thread */
529 atomic_t ready; /* ready to start flag */
530 atomic_t stop; /* ready to stop flag */
531 int ret; /* return code */
532 wait_queue_head_t go; /* start compression */
533 wait_queue_head_t done; /* compression done */
534 size_t unc_len; /* uncompressed length */
535 size_t cmp_len; /* compressed length */
536 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
537 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
538 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
539};
540
541/**
542 * Compression function that runs in its own thread.
543 */
544static int lzo_compress_threadfn(void *data)
545{
546 struct cmp_data *d = data;
547
548 while (1) {
549 wait_event(d->go, atomic_read(&d->ready) ||
550 kthread_should_stop());
551 if (kthread_should_stop()) {
552 d->thr = NULL;
553 d->ret = -1;
554 atomic_set(&d->stop, 1);
555 wake_up(&d->done);
556 break;
557 }
558 atomic_set(&d->ready, 0);
559
560 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
561 d->cmp + LZO_HEADER, &d->cmp_len,
562 d->wrk);
563 atomic_set(&d->stop, 1);
564 wake_up(&d->done);
565 }
566 return 0;
567}
568
569/**
570 * save_image_lzo - Save the suspend image data compressed with LZO.
571 * @handle: Swap mam handle to use for saving the image.
572 * @snapshot: Image to read data from.
573 * @nr_to_write: Number of pages to save.
574 */
575static int save_image_lzo(struct swap_map_handle *handle,
576 struct snapshot_handle *snapshot,
577 unsigned int nr_to_write)
578{
579 unsigned int m;
580 int ret = 0;
581 int nr_pages;
582 int err2;
583 struct bio *bio;
584 struct timeval start;
585 struct timeval stop;
586 size_t off;
587 unsigned thr, run_threads, nr_threads;
588 unsigned char *page = NULL;
589 struct cmp_data *data = NULL;
590 struct crc_data *crc = NULL;
591
592 /*
593 * We'll limit the number of threads for compression to limit memory
594 * footprint.
595 */
596 nr_threads = num_online_cpus() - 1;
597 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
598
599 page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
600 if (!page) {
601 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
602 ret = -ENOMEM;
603 goto out_clean;
604 }
605
606 data = vmalloc(sizeof(*data) * nr_threads);
607 if (!data) {
608 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
609 ret = -ENOMEM;
610 goto out_clean;
611 }
612 for (thr = 0; thr < nr_threads; thr++)
613 memset(&data[thr], 0, offsetof(struct cmp_data, go));
614
615 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
616 if (!crc) {
617 printk(KERN_ERR "PM: Failed to allocate crc\n");
618 ret = -ENOMEM;
619 goto out_clean;
620 }
621 memset(crc, 0, offsetof(struct crc_data, go));
622
623 /*
624 * Start the compression threads.
625 */
626 for (thr = 0; thr < nr_threads; thr++) {
627 init_waitqueue_head(&data[thr].go);
628 init_waitqueue_head(&data[thr].done);
629
630 data[thr].thr = kthread_run(lzo_compress_threadfn,
631 &data[thr],
632 "image_compress/%u", thr);
633 if (IS_ERR(data[thr].thr)) {
634 data[thr].thr = NULL;
635 printk(KERN_ERR
636 "PM: Cannot start compression threads\n");
637 ret = -ENOMEM;
638 goto out_clean;
639 }
640 }
641
642 /*
643 * Start the CRC32 thread.
644 */
645 init_waitqueue_head(&crc->go);
646 init_waitqueue_head(&crc->done);
647
648 handle->crc32 = 0;
649 crc->crc32 = &handle->crc32;
650 for (thr = 0; thr < nr_threads; thr++) {
651 crc->unc[thr] = data[thr].unc;
652 crc->unc_len[thr] = &data[thr].unc_len;
653 }
654
655 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
656 if (IS_ERR(crc->thr)) {
657 crc->thr = NULL;
658 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
659 ret = -ENOMEM;
660 goto out_clean;
661 }
662
663 /*
664 * Adjust the number of required free pages after all allocations have
665 * been done. We don't want to run out of pages when writing.
666 */
667 handle->reqd_free_pages = reqd_free_pages();
668
669 printk(KERN_INFO
670 "PM: Using %u thread(s) for compression.\n"
671 "PM: Compressing and saving image data (%u pages) ... ",
672 nr_threads, nr_to_write);
673 m = nr_to_write / 100;
674 if (!m)
675 m = 1;
676 nr_pages = 0;
677 bio = NULL;
678 do_gettimeofday(&start);
679 for (;;) {
680 for (thr = 0; thr < nr_threads; thr++) {
681 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
682 ret = snapshot_read_next(snapshot);
683 if (ret < 0)
684 goto out_finish;
685
686 if (!ret)
687 break;
688
689 memcpy(data[thr].unc + off,
690 data_of(*snapshot), PAGE_SIZE);
691
692 if (!(nr_pages % m))
693 printk(KERN_CONT "\b\b\b\b%3d%%",
694 nr_pages / m);
695 nr_pages++;
696 }
697 if (!off)
698 break;
699
700 data[thr].unc_len = off;
701
702 atomic_set(&data[thr].ready, 1);
703 wake_up(&data[thr].go);
704 }
705
706 if (!thr)
707 break;
708
709 crc->run_threads = thr;
710 atomic_set(&crc->ready, 1);
711 wake_up(&crc->go);
712
713 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
714 wait_event(data[thr].done,
715 atomic_read(&data[thr].stop));
716 atomic_set(&data[thr].stop, 0);
717
718 ret = data[thr].ret;
719
720 if (ret < 0) {
721 printk(KERN_ERR "PM: LZO compression failed\n");
722 goto out_finish;
723 }
724
725 if (unlikely(!data[thr].cmp_len ||
726 data[thr].cmp_len >
727 lzo1x_worst_compress(data[thr].unc_len))) {
728 printk(KERN_ERR
729 "PM: Invalid LZO compressed length\n");
730 ret = -1;
731 goto out_finish;
732 }
733
734 *(size_t *)data[thr].cmp = data[thr].cmp_len;
735
736 /*
737 * Given we are writing one page at a time to disk, we
738 * copy that much from the buffer, although the last
739 * bit will likely be smaller than full page. This is
740 * OK - we saved the length of the compressed data, so
741 * any garbage at the end will be discarded when we
742 * read it.
743 */
744 for (off = 0;
745 off < LZO_HEADER + data[thr].cmp_len;
746 off += PAGE_SIZE) {
747 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
748
749 ret = swap_write_page(handle, page, &bio);
750 if (ret)
751 goto out_finish;
752 }
753 }
754
755 wait_event(crc->done, atomic_read(&crc->stop));
756 atomic_set(&crc->stop, 0);
757 }
758
759out_finish:
760 err2 = hib_wait_on_bio_chain(&bio);
761 do_gettimeofday(&stop);
762 if (!ret)
763 ret = err2;
764 if (!ret) {
765 printk(KERN_CONT "\b\b\b\bdone\n");
766 } else {
767 printk(KERN_CONT "\n");
768 }
769 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
770out_clean:
771 if (crc) {
772 if (crc->thr)
773 kthread_stop(crc->thr);
774 kfree(crc);
775 }
776 if (data) {
777 for (thr = 0; thr < nr_threads; thr++)
778 if (data[thr].thr)
779 kthread_stop(data[thr].thr);
780 vfree(data);
781 }
782 if (page) free_page((unsigned long)page);
783
784 return ret;
785}
786
787/**
788 * enough_swap - Make sure we have enough swap to save the image.
789 *
790 * Returns TRUE or FALSE after checking the total amount of swap
791 * space avaiable from the resume partition.
792 */
793
794static int enough_swap(unsigned int nr_pages, unsigned int flags)
795{
796 unsigned int free_swap = count_swap_pages(root_swap, 1);
797 unsigned int required;
798
799 pr_debug("PM: Free swap pages: %u\n", free_swap);
800
801 required = PAGES_FOR_IO + nr_pages;
802 return free_swap > required;
803}
804
805/**
806 * swsusp_write - Write entire image and metadata.
807 * @flags: flags to pass to the "boot" kernel in the image header
808 *
809 * It is important _NOT_ to umount filesystems at this point. We want
810 * them synced (in case something goes wrong) but we DO not want to mark
811 * filesystem clean: it is not. (And it does not matter, if we resume
812 * correctly, we'll mark system clean, anyway.)
813 */
814
815int swsusp_write(unsigned int flags)
816{
817 struct swap_map_handle handle;
818 struct snapshot_handle snapshot;
819 struct swsusp_info *header;
820 unsigned long pages;
821 int error;
822
823 pages = snapshot_get_image_size();
824 error = get_swap_writer(&handle);
825 if (error) {
826 printk(KERN_ERR "PM: Cannot get swap writer\n");
827 return error;
828 }
829 if (flags & SF_NOCOMPRESS_MODE) {
830 if (!enough_swap(pages, flags)) {
831 printk(KERN_ERR "PM: Not enough free swap\n");
832 error = -ENOSPC;
833 goto out_finish;
834 }
835 }
836 memset(&snapshot, 0, sizeof(struct snapshot_handle));
837 error = snapshot_read_next(&snapshot);
838 if (error < PAGE_SIZE) {
839 if (error >= 0)
840 error = -EFAULT;
841
842 goto out_finish;
843 }
844 header = (struct swsusp_info *)data_of(snapshot);
845 error = swap_write_page(&handle, header, NULL);
846 if (!error) {
847 error = (flags & SF_NOCOMPRESS_MODE) ?
848 save_image(&handle, &snapshot, pages - 1) :
849 save_image_lzo(&handle, &snapshot, pages - 1);
850 }
851out_finish:
852 error = swap_writer_finish(&handle, flags, error);
853 return error;
854}
855
856/**
857 * The following functions allow us to read data using a swap map
858 * in a file-alike way
859 */
860
861static void release_swap_reader(struct swap_map_handle *handle)
862{
863 struct swap_map_page_list *tmp;
864
865 while (handle->maps) {
866 if (handle->maps->map)
867 free_page((unsigned long)handle->maps->map);
868 tmp = handle->maps;
869 handle->maps = handle->maps->next;
870 kfree(tmp);
871 }
872 handle->cur = NULL;
873}
874
875static int get_swap_reader(struct swap_map_handle *handle,
876 unsigned int *flags_p)
877{
878 int error;
879 struct swap_map_page_list *tmp, *last;
880 sector_t offset;
881
882 *flags_p = swsusp_header->flags;
883
884 if (!swsusp_header->image) /* how can this happen? */
885 return -EINVAL;
886
887 handle->cur = NULL;
888 last = handle->maps = NULL;
889 offset = swsusp_header->image;
890 while (offset) {
891 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
892 if (!tmp) {
893 release_swap_reader(handle);
894 return -ENOMEM;
895 }
896 memset(tmp, 0, sizeof(*tmp));
897 if (!handle->maps)
898 handle->maps = tmp;
899 if (last)
900 last->next = tmp;
901 last = tmp;
902
903 tmp->map = (struct swap_map_page *)
904 __get_free_page(__GFP_WAIT | __GFP_HIGH);
905 if (!tmp->map) {
906 release_swap_reader(handle);
907 return -ENOMEM;
908 }
909
910 error = hib_bio_read_page(offset, tmp->map, NULL);
911 if (error) {
912 release_swap_reader(handle);
913 return error;
914 }
915 offset = tmp->map->next_swap;
916 }
917 handle->k = 0;
918 handle->cur = handle->maps->map;
919 return 0;
920}
921
922static int swap_read_page(struct swap_map_handle *handle, void *buf,
923 struct bio **bio_chain)
924{
925 sector_t offset;
926 int error;
927 struct swap_map_page_list *tmp;
928
929 if (!handle->cur)
930 return -EINVAL;
931 offset = handle->cur->entries[handle->k];
932 if (!offset)
933 return -EFAULT;
934 error = hib_bio_read_page(offset, buf, bio_chain);
935 if (error)
936 return error;
937 if (++handle->k >= MAP_PAGE_ENTRIES) {
938 handle->k = 0;
939 free_page((unsigned long)handle->maps->map);
940 tmp = handle->maps;
941 handle->maps = handle->maps->next;
942 kfree(tmp);
943 if (!handle->maps)
944 release_swap_reader(handle);
945 else
946 handle->cur = handle->maps->map;
947 }
948 return error;
949}
950
951static int swap_reader_finish(struct swap_map_handle *handle)
952{
953 release_swap_reader(handle);
954
955 return 0;
956}
957
958/**
959 * load_image - load the image using the swap map handle
960 * @handle and the snapshot handle @snapshot
961 * (assume there are @nr_pages pages to load)
962 */
963
964static int load_image(struct swap_map_handle *handle,
965 struct snapshot_handle *snapshot,
966 unsigned int nr_to_read)
967{
968 unsigned int m;
969 int ret = 0;
970 struct timeval start;
971 struct timeval stop;
972 struct bio *bio;
973 int err2;
974 unsigned nr_pages;
975
976 printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ",
977 nr_to_read);
978 m = nr_to_read / 100;
979 if (!m)
980 m = 1;
981 nr_pages = 0;
982 bio = NULL;
983 do_gettimeofday(&start);
984 for ( ; ; ) {
985 ret = snapshot_write_next(snapshot);
986 if (ret <= 0)
987 break;
988 ret = swap_read_page(handle, data_of(*snapshot), &bio);
989 if (ret)
990 break;
991 if (snapshot->sync_read)
992 ret = hib_wait_on_bio_chain(&bio);
993 if (ret)
994 break;
995 if (!(nr_pages % m))
996 printk("\b\b\b\b%3d%%", nr_pages / m);
997 nr_pages++;
998 }
999 err2 = hib_wait_on_bio_chain(&bio);
1000 do_gettimeofday(&stop);
1001 if (!ret)
1002 ret = err2;
1003 if (!ret) {
1004 printk("\b\b\b\bdone\n");
1005 snapshot_write_finalize(snapshot);
1006 if (!snapshot_image_loaded(snapshot))
1007 ret = -ENODATA;
1008 } else
1009 printk("\n");
1010 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1011 return ret;
1012}
1013
1014/**
1015 * Structure used for LZO data decompression.
1016 */
1017struct dec_data {
1018 struct task_struct *thr; /* thread */
1019 atomic_t ready; /* ready to start flag */
1020 atomic_t stop; /* ready to stop flag */
1021 int ret; /* return code */
1022 wait_queue_head_t go; /* start decompression */
1023 wait_queue_head_t done; /* decompression done */
1024 size_t unc_len; /* uncompressed length */
1025 size_t cmp_len; /* compressed length */
1026 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1027 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1028};
1029
1030/**
1031 * Deompression function that runs in its own thread.
1032 */
1033static int lzo_decompress_threadfn(void *data)
1034{
1035 struct dec_data *d = data;
1036
1037 while (1) {
1038 wait_event(d->go, atomic_read(&d->ready) ||
1039 kthread_should_stop());
1040 if (kthread_should_stop()) {
1041 d->thr = NULL;
1042 d->ret = -1;
1043 atomic_set(&d->stop, 1);
1044 wake_up(&d->done);
1045 break;
1046 }
1047 atomic_set(&d->ready, 0);
1048
1049 d->unc_len = LZO_UNC_SIZE;
1050 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1051 d->unc, &d->unc_len);
1052 atomic_set(&d->stop, 1);
1053 wake_up(&d->done);
1054 }
1055 return 0;
1056}
1057
1058/**
1059 * load_image_lzo - Load compressed image data and decompress them with LZO.
1060 * @handle: Swap map handle to use for loading data.
1061 * @snapshot: Image to copy uncompressed data into.
1062 * @nr_to_read: Number of pages to load.
1063 */
1064static int load_image_lzo(struct swap_map_handle *handle,
1065 struct snapshot_handle *snapshot,
1066 unsigned int nr_to_read)
1067{
1068 unsigned int m;
1069 int ret = 0;
1070 int eof = 0;
1071 struct bio *bio;
1072 struct timeval start;
1073 struct timeval stop;
1074 unsigned nr_pages;
1075 size_t off;
1076 unsigned i, thr, run_threads, nr_threads;
1077 unsigned ring = 0, pg = 0, ring_size = 0,
1078 have = 0, want, need, asked = 0;
1079 unsigned long read_pages = 0;
1080 unsigned char **page = NULL;
1081 struct dec_data *data = NULL;
1082 struct crc_data *crc = NULL;
1083
1084 /*
1085 * We'll limit the number of threads for decompression to limit memory
1086 * footprint.
1087 */
1088 nr_threads = num_online_cpus() - 1;
1089 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1090
1091 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1092 if (!page) {
1093 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1094 ret = -ENOMEM;
1095 goto out_clean;
1096 }
1097
1098 data = vmalloc(sizeof(*data) * nr_threads);
1099 if (!data) {
1100 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1101 ret = -ENOMEM;
1102 goto out_clean;
1103 }
1104 for (thr = 0; thr < nr_threads; thr++)
1105 memset(&data[thr], 0, offsetof(struct dec_data, go));
1106
1107 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1108 if (!crc) {
1109 printk(KERN_ERR "PM: Failed to allocate crc\n");
1110 ret = -ENOMEM;
1111 goto out_clean;
1112 }
1113 memset(crc, 0, offsetof(struct crc_data, go));
1114
1115 /*
1116 * Start the decompression threads.
1117 */
1118 for (thr = 0; thr < nr_threads; thr++) {
1119 init_waitqueue_head(&data[thr].go);
1120 init_waitqueue_head(&data[thr].done);
1121
1122 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1123 &data[thr],
1124 "image_decompress/%u", thr);
1125 if (IS_ERR(data[thr].thr)) {
1126 data[thr].thr = NULL;
1127 printk(KERN_ERR
1128 "PM: Cannot start decompression threads\n");
1129 ret = -ENOMEM;
1130 goto out_clean;
1131 }
1132 }
1133
1134 /*
1135 * Start the CRC32 thread.
1136 */
1137 init_waitqueue_head(&crc->go);
1138 init_waitqueue_head(&crc->done);
1139
1140 handle->crc32 = 0;
1141 crc->crc32 = &handle->crc32;
1142 for (thr = 0; thr < nr_threads; thr++) {
1143 crc->unc[thr] = data[thr].unc;
1144 crc->unc_len[thr] = &data[thr].unc_len;
1145 }
1146
1147 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1148 if (IS_ERR(crc->thr)) {
1149 crc->thr = NULL;
1150 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1151 ret = -ENOMEM;
1152 goto out_clean;
1153 }
1154
1155 /*
1156 * Set the number of pages for read buffering.
1157 * This is complete guesswork, because we'll only know the real
1158 * picture once prepare_image() is called, which is much later on
1159 * during the image load phase. We'll assume the worst case and
1160 * say that none of the image pages are from high memory.
1161 */
1162 if (low_free_pages() > snapshot_get_image_size())
1163 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1164 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1165
1166 for (i = 0; i < read_pages; i++) {
1167 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1168 __GFP_WAIT | __GFP_HIGH :
1169 __GFP_WAIT | __GFP_NOWARN |
1170 __GFP_NORETRY);
1171
1172 if (!page[i]) {
1173 if (i < LZO_CMP_PAGES) {
1174 ring_size = i;
1175 printk(KERN_ERR
1176 "PM: Failed to allocate LZO pages\n");
1177 ret = -ENOMEM;
1178 goto out_clean;
1179 } else {
1180 break;
1181 }
1182 }
1183 }
1184 want = ring_size = i;
1185
1186 printk(KERN_INFO
1187 "PM: Using %u thread(s) for decompression.\n"
1188 "PM: Loading and decompressing image data (%u pages) ... ",
1189 nr_threads, nr_to_read);
1190 m = nr_to_read / 100;
1191 if (!m)
1192 m = 1;
1193 nr_pages = 0;
1194 bio = NULL;
1195 do_gettimeofday(&start);
1196
1197 ret = snapshot_write_next(snapshot);
1198 if (ret <= 0)
1199 goto out_finish;
1200
1201 for(;;) {
1202 for (i = 0; !eof && i < want; i++) {
1203 ret = swap_read_page(handle, page[ring], &bio);
1204 if (ret) {
1205 /*
1206 * On real read error, finish. On end of data,
1207 * set EOF flag and just exit the read loop.
1208 */
1209 if (handle->cur &&
1210 handle->cur->entries[handle->k]) {
1211 goto out_finish;
1212 } else {
1213 eof = 1;
1214 break;
1215 }
1216 }
1217 if (++ring >= ring_size)
1218 ring = 0;
1219 }
1220 asked += i;
1221 want -= i;
1222
1223 /*
1224 * We are out of data, wait for some more.
1225 */
1226 if (!have) {
1227 if (!asked)
1228 break;
1229
1230 ret = hib_wait_on_bio_chain(&bio);
1231 if (ret)
1232 goto out_finish;
1233 have += asked;
1234 asked = 0;
1235 if (eof)
1236 eof = 2;
1237 }
1238
1239 if (crc->run_threads) {
1240 wait_event(crc->done, atomic_read(&crc->stop));
1241 atomic_set(&crc->stop, 0);
1242 crc->run_threads = 0;
1243 }
1244
1245 for (thr = 0; have && thr < nr_threads; thr++) {
1246 data[thr].cmp_len = *(size_t *)page[pg];
1247 if (unlikely(!data[thr].cmp_len ||
1248 data[thr].cmp_len >
1249 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1250 printk(KERN_ERR
1251 "PM: Invalid LZO compressed length\n");
1252 ret = -1;
1253 goto out_finish;
1254 }
1255
1256 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1257 PAGE_SIZE);
1258 if (need > have) {
1259 if (eof > 1) {
1260 ret = -1;
1261 goto out_finish;
1262 }
1263 break;
1264 }
1265
1266 for (off = 0;
1267 off < LZO_HEADER + data[thr].cmp_len;
1268 off += PAGE_SIZE) {
1269 memcpy(data[thr].cmp + off,
1270 page[pg], PAGE_SIZE);
1271 have--;
1272 want++;
1273 if (++pg >= ring_size)
1274 pg = 0;
1275 }
1276
1277 atomic_set(&data[thr].ready, 1);
1278 wake_up(&data[thr].go);
1279 }
1280
1281 /*
1282 * Wait for more data while we are decompressing.
1283 */
1284 if (have < LZO_CMP_PAGES && asked) {
1285 ret = hib_wait_on_bio_chain(&bio);
1286 if (ret)
1287 goto out_finish;
1288 have += asked;
1289 asked = 0;
1290 if (eof)
1291 eof = 2;
1292 }
1293
1294 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1295 wait_event(data[thr].done,
1296 atomic_read(&data[thr].stop));
1297 atomic_set(&data[thr].stop, 0);
1298
1299 ret = data[thr].ret;
1300
1301 if (ret < 0) {
1302 printk(KERN_ERR
1303 "PM: LZO decompression failed\n");
1304 goto out_finish;
1305 }
1306
1307 if (unlikely(!data[thr].unc_len ||
1308 data[thr].unc_len > LZO_UNC_SIZE ||
1309 data[thr].unc_len & (PAGE_SIZE - 1))) {
1310 printk(KERN_ERR
1311 "PM: Invalid LZO uncompressed length\n");
1312 ret = -1;
1313 goto out_finish;
1314 }
1315
1316 for (off = 0;
1317 off < data[thr].unc_len; off += PAGE_SIZE) {
1318 memcpy(data_of(*snapshot),
1319 data[thr].unc + off, PAGE_SIZE);
1320
1321 if (!(nr_pages % m))
1322 printk("\b\b\b\b%3d%%", nr_pages / m);
1323 nr_pages++;
1324
1325 ret = snapshot_write_next(snapshot);
1326 if (ret <= 0) {
1327 crc->run_threads = thr + 1;
1328 atomic_set(&crc->ready, 1);
1329 wake_up(&crc->go);
1330 goto out_finish;
1331 }
1332 }
1333 }
1334
1335 crc->run_threads = thr;
1336 atomic_set(&crc->ready, 1);
1337 wake_up(&crc->go);
1338 }
1339
1340out_finish:
1341 if (crc->run_threads) {
1342 wait_event(crc->done, atomic_read(&crc->stop));
1343 atomic_set(&crc->stop, 0);
1344 }
1345 do_gettimeofday(&stop);
1346 if (!ret) {
1347 printk("\b\b\b\bdone\n");
1348 snapshot_write_finalize(snapshot);
1349 if (!snapshot_image_loaded(snapshot))
1350 ret = -ENODATA;
1351 if (!ret) {
1352 if (swsusp_header->flags & SF_CRC32_MODE) {
1353 if(handle->crc32 != swsusp_header->crc32) {
1354 printk(KERN_ERR
1355 "PM: Invalid image CRC32!\n");
1356 ret = -ENODATA;
1357 }
1358 }
1359 }
1360 } else
1361 printk("\n");
1362 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1363out_clean:
1364 for (i = 0; i < ring_size; i++)
1365 free_page((unsigned long)page[i]);
1366 if (crc) {
1367 if (crc->thr)
1368 kthread_stop(crc->thr);
1369 kfree(crc);
1370 }
1371 if (data) {
1372 for (thr = 0; thr < nr_threads; thr++)
1373 if (data[thr].thr)
1374 kthread_stop(data[thr].thr);
1375 vfree(data);
1376 }
1377 if (page) vfree(page);
1378
1379 return ret;
1380}
1381
1382/**
1383 * swsusp_read - read the hibernation image.
1384 * @flags_p: flags passed by the "frozen" kernel in the image header should
1385 * be written into this memory location
1386 */
1387
1388int swsusp_read(unsigned int *flags_p)
1389{
1390 int error;
1391 struct swap_map_handle handle;
1392 struct snapshot_handle snapshot;
1393 struct swsusp_info *header;
1394
1395 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1396 error = snapshot_write_next(&snapshot);
1397 if (error < PAGE_SIZE)
1398 return error < 0 ? error : -EFAULT;
1399 header = (struct swsusp_info *)data_of(snapshot);
1400 error = get_swap_reader(&handle, flags_p);
1401 if (error)
1402 goto end;
1403 if (!error)
1404 error = swap_read_page(&handle, header, NULL);
1405 if (!error) {
1406 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1407 load_image(&handle, &snapshot, header->pages - 1) :
1408 load_image_lzo(&handle, &snapshot, header->pages - 1);
1409 }
1410 swap_reader_finish(&handle);
1411end:
1412 if (!error)
1413 pr_debug("PM: Image successfully loaded\n");
1414 else
1415 pr_debug("PM: Error %d resuming\n", error);
1416 return error;
1417}
1418
1419/**
1420 * swsusp_check - Check for swsusp signature in the resume device
1421 */
1422
1423int swsusp_check(void)
1424{
1425 int error;
1426
1427 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1428 FMODE_READ, NULL);
1429 if (!IS_ERR(hib_resume_bdev)) {
1430 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1431 clear_page(swsusp_header);
1432 error = hib_bio_read_page(swsusp_resume_block,
1433 swsusp_header, NULL);
1434 if (error)
1435 goto put;
1436
1437 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1438 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1439 /* Reset swap signature now */
1440 error = hib_bio_write_page(swsusp_resume_block,
1441 swsusp_header, NULL);
1442 } else {
1443 error = -EINVAL;
1444 }
1445
1446put:
1447 if (error)
1448 blkdev_put(hib_resume_bdev, FMODE_READ);
1449 else
1450 pr_debug("PM: Image signature found, resuming\n");
1451 } else {
1452 error = PTR_ERR(hib_resume_bdev);
1453 }
1454
1455 if (error)
1456 pr_debug("PM: Image not found (code %d)\n", error);
1457
1458 return error;
1459}
1460
1461/**
1462 * swsusp_close - close swap device.
1463 */
1464
1465void swsusp_close(fmode_t mode)
1466{
1467 if (IS_ERR(hib_resume_bdev)) {
1468 pr_debug("PM: Image device not initialised\n");
1469 return;
1470 }
1471
1472 blkdev_put(hib_resume_bdev, mode);
1473}
1474
1475static int swsusp_header_init(void)
1476{
1477 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1478 if (!swsusp_header)
1479 panic("Could not allocate memory for swsusp_header\n");
1480 return 0;
1481}
1482
1483core_initcall(swsusp_header_init);
1// SPDX-License-Identifier: GPL-2.0-only
2/*
3 * linux/kernel/power/swap.c
4 *
5 * This file provides functions for reading the suspend image from
6 * and writing it to a swap partition.
7 *
8 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
9 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
10 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
11 */
12
13#define pr_fmt(fmt) "PM: " fmt
14
15#include <linux/module.h>
16#include <linux/file.h>
17#include <linux/delay.h>
18#include <linux/bitops.h>
19#include <linux/device.h>
20#include <linux/bio.h>
21#include <linux/blkdev.h>
22#include <linux/swap.h>
23#include <linux/swapops.h>
24#include <linux/pm.h>
25#include <linux/slab.h>
26#include <linux/vmalloc.h>
27#include <linux/cpumask.h>
28#include <linux/atomic.h>
29#include <linux/kthread.h>
30#include <linux/crc32.h>
31#include <linux/ktime.h>
32
33#include "power.h"
34
35#define HIBERNATE_SIG "S1SUSPEND"
36
37u32 swsusp_hardware_signature;
38
39/*
40 * When reading an {un,}compressed image, we may restore pages in place,
41 * in which case some architectures need these pages cleaning before they
42 * can be executed. We don't know which pages these may be, so clean the lot.
43 */
44static bool clean_pages_on_read;
45static bool clean_pages_on_decompress;
46
47/*
48 * The swap map is a data structure used for keeping track of each page
49 * written to a swap partition. It consists of many swap_map_page
50 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
51 * These structures are stored on the swap and linked together with the
52 * help of the .next_swap member.
53 *
54 * The swap map is created during suspend. The swap map pages are
55 * allocated and populated one at a time, so we only need one memory
56 * page to set up the entire structure.
57 *
58 * During resume we pick up all swap_map_page structures into a list.
59 */
60
61#define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
62
63/*
64 * Number of free pages that are not high.
65 */
66static inline unsigned long low_free_pages(void)
67{
68 return nr_free_pages() - nr_free_highpages();
69}
70
71/*
72 * Number of pages required to be kept free while writing the image. Always
73 * half of all available low pages before the writing starts.
74 */
75static inline unsigned long reqd_free_pages(void)
76{
77 return low_free_pages() / 2;
78}
79
80struct swap_map_page {
81 sector_t entries[MAP_PAGE_ENTRIES];
82 sector_t next_swap;
83};
84
85struct swap_map_page_list {
86 struct swap_map_page *map;
87 struct swap_map_page_list *next;
88};
89
90/*
91 * The swap_map_handle structure is used for handling swap in
92 * a file-alike way
93 */
94
95struct swap_map_handle {
96 struct swap_map_page *cur;
97 struct swap_map_page_list *maps;
98 sector_t cur_swap;
99 sector_t first_sector;
100 unsigned int k;
101 unsigned long reqd_free_pages;
102 u32 crc32;
103};
104
105struct swsusp_header {
106 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
107 sizeof(u32) - sizeof(u32)];
108 u32 hw_sig;
109 u32 crc32;
110 sector_t image;
111 unsigned int flags; /* Flags to pass to the "boot" kernel */
112 char orig_sig[10];
113 char sig[10];
114} __packed;
115
116static struct swsusp_header *swsusp_header;
117
118/*
119 * The following functions are used for tracing the allocated
120 * swap pages, so that they can be freed in case of an error.
121 */
122
123struct swsusp_extent {
124 struct rb_node node;
125 unsigned long start;
126 unsigned long end;
127};
128
129static struct rb_root swsusp_extents = RB_ROOT;
130
131static int swsusp_extents_insert(unsigned long swap_offset)
132{
133 struct rb_node **new = &(swsusp_extents.rb_node);
134 struct rb_node *parent = NULL;
135 struct swsusp_extent *ext;
136
137 /* Figure out where to put the new node */
138 while (*new) {
139 ext = rb_entry(*new, struct swsusp_extent, node);
140 parent = *new;
141 if (swap_offset < ext->start) {
142 /* Try to merge */
143 if (swap_offset == ext->start - 1) {
144 ext->start--;
145 return 0;
146 }
147 new = &((*new)->rb_left);
148 } else if (swap_offset > ext->end) {
149 /* Try to merge */
150 if (swap_offset == ext->end + 1) {
151 ext->end++;
152 return 0;
153 }
154 new = &((*new)->rb_right);
155 } else {
156 /* It already is in the tree */
157 return -EINVAL;
158 }
159 }
160 /* Add the new node and rebalance the tree. */
161 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
162 if (!ext)
163 return -ENOMEM;
164
165 ext->start = swap_offset;
166 ext->end = swap_offset;
167 rb_link_node(&ext->node, parent, new);
168 rb_insert_color(&ext->node, &swsusp_extents);
169 return 0;
170}
171
172/*
173 * alloc_swapdev_block - allocate a swap page and register that it has
174 * been allocated, so that it can be freed in case of an error.
175 */
176
177sector_t alloc_swapdev_block(int swap)
178{
179 unsigned long offset;
180
181 offset = swp_offset(get_swap_page_of_type(swap));
182 if (offset) {
183 if (swsusp_extents_insert(offset))
184 swap_free(swp_entry(swap, offset));
185 else
186 return swapdev_block(swap, offset);
187 }
188 return 0;
189}
190
191/*
192 * free_all_swap_pages - free swap pages allocated for saving image data.
193 * It also frees the extents used to register which swap entries had been
194 * allocated.
195 */
196
197void free_all_swap_pages(int swap)
198{
199 struct rb_node *node;
200
201 while ((node = swsusp_extents.rb_node)) {
202 struct swsusp_extent *ext;
203 unsigned long offset;
204
205 ext = rb_entry(node, struct swsusp_extent, node);
206 rb_erase(node, &swsusp_extents);
207 for (offset = ext->start; offset <= ext->end; offset++)
208 swap_free(swp_entry(swap, offset));
209
210 kfree(ext);
211 }
212}
213
214int swsusp_swap_in_use(void)
215{
216 return (swsusp_extents.rb_node != NULL);
217}
218
219/*
220 * General things
221 */
222
223static unsigned short root_swap = 0xffff;
224static struct file *hib_resume_bdev_file;
225
226struct hib_bio_batch {
227 atomic_t count;
228 wait_queue_head_t wait;
229 blk_status_t error;
230 struct blk_plug plug;
231};
232
233static void hib_init_batch(struct hib_bio_batch *hb)
234{
235 atomic_set(&hb->count, 0);
236 init_waitqueue_head(&hb->wait);
237 hb->error = BLK_STS_OK;
238 blk_start_plug(&hb->plug);
239}
240
241static void hib_finish_batch(struct hib_bio_batch *hb)
242{
243 blk_finish_plug(&hb->plug);
244}
245
246static void hib_end_io(struct bio *bio)
247{
248 struct hib_bio_batch *hb = bio->bi_private;
249 struct page *page = bio_first_page_all(bio);
250
251 if (bio->bi_status) {
252 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
253 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
254 (unsigned long long)bio->bi_iter.bi_sector);
255 }
256
257 if (bio_data_dir(bio) == WRITE)
258 put_page(page);
259 else if (clean_pages_on_read)
260 flush_icache_range((unsigned long)page_address(page),
261 (unsigned long)page_address(page) + PAGE_SIZE);
262
263 if (bio->bi_status && !hb->error)
264 hb->error = bio->bi_status;
265 if (atomic_dec_and_test(&hb->count))
266 wake_up(&hb->wait);
267
268 bio_put(bio);
269}
270
271static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
272 struct hib_bio_batch *hb)
273{
274 struct page *page = virt_to_page(addr);
275 struct bio *bio;
276 int error = 0;
277
278 bio = bio_alloc(file_bdev(hib_resume_bdev_file), 1, opf,
279 GFP_NOIO | __GFP_HIGH);
280 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
281
282 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
283 pr_err("Adding page to bio failed at %llu\n",
284 (unsigned long long)bio->bi_iter.bi_sector);
285 bio_put(bio);
286 return -EFAULT;
287 }
288
289 if (hb) {
290 bio->bi_end_io = hib_end_io;
291 bio->bi_private = hb;
292 atomic_inc(&hb->count);
293 submit_bio(bio);
294 } else {
295 error = submit_bio_wait(bio);
296 bio_put(bio);
297 }
298
299 return error;
300}
301
302static int hib_wait_io(struct hib_bio_batch *hb)
303{
304 /*
305 * We are relying on the behavior of blk_plug that a thread with
306 * a plug will flush the plug list before sleeping.
307 */
308 wait_event(hb->wait, atomic_read(&hb->count) == 0);
309 return blk_status_to_errno(hb->error);
310}
311
312/*
313 * Saving part
314 */
315static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
316{
317 int error;
318
319 hib_submit_io(REQ_OP_READ, swsusp_resume_block, swsusp_header, NULL);
320 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
321 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
322 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
323 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
324 swsusp_header->image = handle->first_sector;
325 if (swsusp_hardware_signature) {
326 swsusp_header->hw_sig = swsusp_hardware_signature;
327 flags |= SF_HW_SIG;
328 }
329 swsusp_header->flags = flags;
330 if (flags & SF_CRC32_MODE)
331 swsusp_header->crc32 = handle->crc32;
332 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
333 swsusp_resume_block, swsusp_header, NULL);
334 } else {
335 pr_err("Swap header not found!\n");
336 error = -ENODEV;
337 }
338 return error;
339}
340
341/*
342 * Hold the swsusp_header flag. This is used in software_resume() in
343 * 'kernel/power/hibernate' to check if the image is compressed and query
344 * for the compression algorithm support(if so).
345 */
346unsigned int swsusp_header_flags;
347
348/**
349 * swsusp_swap_check - check if the resume device is a swap device
350 * and get its index (if so)
351 *
352 * This is called before saving image
353 */
354static int swsusp_swap_check(void)
355{
356 int res;
357
358 if (swsusp_resume_device)
359 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
360 else
361 res = find_first_swap(&swsusp_resume_device);
362 if (res < 0)
363 return res;
364 root_swap = res;
365
366 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
367 BLK_OPEN_WRITE, NULL, NULL);
368 if (IS_ERR(hib_resume_bdev_file))
369 return PTR_ERR(hib_resume_bdev_file);
370
371 res = set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
372 if (res < 0)
373 fput(hib_resume_bdev_file);
374
375 return res;
376}
377
378/**
379 * write_page - Write one page to given swap location.
380 * @buf: Address we're writing.
381 * @offset: Offset of the swap page we're writing to.
382 * @hb: bio completion batch
383 */
384
385static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
386{
387 void *src;
388 int ret;
389
390 if (!offset)
391 return -ENOSPC;
392
393 if (hb) {
394 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
395 __GFP_NORETRY);
396 if (src) {
397 copy_page(src, buf);
398 } else {
399 ret = hib_wait_io(hb); /* Free pages */
400 if (ret)
401 return ret;
402 src = (void *)__get_free_page(GFP_NOIO |
403 __GFP_NOWARN |
404 __GFP_NORETRY);
405 if (src) {
406 copy_page(src, buf);
407 } else {
408 WARN_ON_ONCE(1);
409 hb = NULL; /* Go synchronous */
410 src = buf;
411 }
412 }
413 } else {
414 src = buf;
415 }
416 return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
417}
418
419static void release_swap_writer(struct swap_map_handle *handle)
420{
421 if (handle->cur)
422 free_page((unsigned long)handle->cur);
423 handle->cur = NULL;
424}
425
426static int get_swap_writer(struct swap_map_handle *handle)
427{
428 int ret;
429
430 ret = swsusp_swap_check();
431 if (ret) {
432 if (ret != -ENOSPC)
433 pr_err("Cannot find swap device, try swapon -a\n");
434 return ret;
435 }
436 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
437 if (!handle->cur) {
438 ret = -ENOMEM;
439 goto err_close;
440 }
441 handle->cur_swap = alloc_swapdev_block(root_swap);
442 if (!handle->cur_swap) {
443 ret = -ENOSPC;
444 goto err_rel;
445 }
446 handle->k = 0;
447 handle->reqd_free_pages = reqd_free_pages();
448 handle->first_sector = handle->cur_swap;
449 return 0;
450err_rel:
451 release_swap_writer(handle);
452err_close:
453 swsusp_close();
454 return ret;
455}
456
457static int swap_write_page(struct swap_map_handle *handle, void *buf,
458 struct hib_bio_batch *hb)
459{
460 int error;
461 sector_t offset;
462
463 if (!handle->cur)
464 return -EINVAL;
465 offset = alloc_swapdev_block(root_swap);
466 error = write_page(buf, offset, hb);
467 if (error)
468 return error;
469 handle->cur->entries[handle->k++] = offset;
470 if (handle->k >= MAP_PAGE_ENTRIES) {
471 offset = alloc_swapdev_block(root_swap);
472 if (!offset)
473 return -ENOSPC;
474 handle->cur->next_swap = offset;
475 error = write_page(handle->cur, handle->cur_swap, hb);
476 if (error)
477 goto out;
478 clear_page(handle->cur);
479 handle->cur_swap = offset;
480 handle->k = 0;
481
482 if (hb && low_free_pages() <= handle->reqd_free_pages) {
483 error = hib_wait_io(hb);
484 if (error)
485 goto out;
486 /*
487 * Recalculate the number of required free pages, to
488 * make sure we never take more than half.
489 */
490 handle->reqd_free_pages = reqd_free_pages();
491 }
492 }
493 out:
494 return error;
495}
496
497static int flush_swap_writer(struct swap_map_handle *handle)
498{
499 if (handle->cur && handle->cur_swap)
500 return write_page(handle->cur, handle->cur_swap, NULL);
501 else
502 return -EINVAL;
503}
504
505static int swap_writer_finish(struct swap_map_handle *handle,
506 unsigned int flags, int error)
507{
508 if (!error) {
509 pr_info("S");
510 error = mark_swapfiles(handle, flags);
511 pr_cont("|\n");
512 flush_swap_writer(handle);
513 }
514
515 if (error)
516 free_all_swap_pages(root_swap);
517 release_swap_writer(handle);
518 swsusp_close();
519
520 return error;
521}
522
523/*
524 * Bytes we need for compressed data in worst case. We assume(limitation)
525 * this is the worst of all the compression algorithms.
526 */
527#define bytes_worst_compress(x) ((x) + ((x) / 16) + 64 + 3 + 2)
528
529/* We need to remember how much compressed data we need to read. */
530#define CMP_HEADER sizeof(size_t)
531
532/* Number of pages/bytes we'll compress at one time. */
533#define UNC_PAGES 32
534#define UNC_SIZE (UNC_PAGES * PAGE_SIZE)
535
536/* Number of pages we need for compressed data (worst case). */
537#define CMP_PAGES DIV_ROUND_UP(bytes_worst_compress(UNC_SIZE) + \
538 CMP_HEADER, PAGE_SIZE)
539#define CMP_SIZE (CMP_PAGES * PAGE_SIZE)
540
541/* Maximum number of threads for compression/decompression. */
542#define CMP_THREADS 3
543
544/* Minimum/maximum number of pages for read buffering. */
545#define CMP_MIN_RD_PAGES 1024
546#define CMP_MAX_RD_PAGES 8192
547
548/**
549 * save_image - save the suspend image data
550 */
551
552static int save_image(struct swap_map_handle *handle,
553 struct snapshot_handle *snapshot,
554 unsigned int nr_to_write)
555{
556 unsigned int m;
557 int ret;
558 int nr_pages;
559 int err2;
560 struct hib_bio_batch hb;
561 ktime_t start;
562 ktime_t stop;
563
564 hib_init_batch(&hb);
565
566 pr_info("Saving image data pages (%u pages)...\n",
567 nr_to_write);
568 m = nr_to_write / 10;
569 if (!m)
570 m = 1;
571 nr_pages = 0;
572 start = ktime_get();
573 while (1) {
574 ret = snapshot_read_next(snapshot);
575 if (ret <= 0)
576 break;
577 ret = swap_write_page(handle, data_of(*snapshot), &hb);
578 if (ret)
579 break;
580 if (!(nr_pages % m))
581 pr_info("Image saving progress: %3d%%\n",
582 nr_pages / m * 10);
583 nr_pages++;
584 }
585 err2 = hib_wait_io(&hb);
586 hib_finish_batch(&hb);
587 stop = ktime_get();
588 if (!ret)
589 ret = err2;
590 if (!ret)
591 pr_info("Image saving done\n");
592 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
593 return ret;
594}
595
596/*
597 * Structure used for CRC32.
598 */
599struct crc_data {
600 struct task_struct *thr; /* thread */
601 atomic_t ready; /* ready to start flag */
602 atomic_t stop; /* ready to stop flag */
603 unsigned run_threads; /* nr current threads */
604 wait_queue_head_t go; /* start crc update */
605 wait_queue_head_t done; /* crc update done */
606 u32 *crc32; /* points to handle's crc32 */
607 size_t *unc_len[CMP_THREADS]; /* uncompressed lengths */
608 unsigned char *unc[CMP_THREADS]; /* uncompressed data */
609};
610
611/*
612 * CRC32 update function that runs in its own thread.
613 */
614static int crc32_threadfn(void *data)
615{
616 struct crc_data *d = data;
617 unsigned i;
618
619 while (1) {
620 wait_event(d->go, atomic_read_acquire(&d->ready) ||
621 kthread_should_stop());
622 if (kthread_should_stop()) {
623 d->thr = NULL;
624 atomic_set_release(&d->stop, 1);
625 wake_up(&d->done);
626 break;
627 }
628 atomic_set(&d->ready, 0);
629
630 for (i = 0; i < d->run_threads; i++)
631 *d->crc32 = crc32_le(*d->crc32,
632 d->unc[i], *d->unc_len[i]);
633 atomic_set_release(&d->stop, 1);
634 wake_up(&d->done);
635 }
636 return 0;
637}
638/*
639 * Structure used for data compression.
640 */
641struct cmp_data {
642 struct task_struct *thr; /* thread */
643 struct crypto_comp *cc; /* crypto compressor stream */
644 atomic_t ready; /* ready to start flag */
645 atomic_t stop; /* ready to stop flag */
646 int ret; /* return code */
647 wait_queue_head_t go; /* start compression */
648 wait_queue_head_t done; /* compression done */
649 size_t unc_len; /* uncompressed length */
650 size_t cmp_len; /* compressed length */
651 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
652 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
653};
654
655/* Indicates the image size after compression */
656static atomic_t compressed_size = ATOMIC_INIT(0);
657
658/*
659 * Compression function that runs in its own thread.
660 */
661static int compress_threadfn(void *data)
662{
663 struct cmp_data *d = data;
664 unsigned int cmp_len = 0;
665
666 while (1) {
667 wait_event(d->go, atomic_read_acquire(&d->ready) ||
668 kthread_should_stop());
669 if (kthread_should_stop()) {
670 d->thr = NULL;
671 d->ret = -1;
672 atomic_set_release(&d->stop, 1);
673 wake_up(&d->done);
674 break;
675 }
676 atomic_set(&d->ready, 0);
677
678 cmp_len = CMP_SIZE - CMP_HEADER;
679 d->ret = crypto_comp_compress(d->cc, d->unc, d->unc_len,
680 d->cmp + CMP_HEADER,
681 &cmp_len);
682 d->cmp_len = cmp_len;
683
684 atomic_set(&compressed_size, atomic_read(&compressed_size) + d->cmp_len);
685 atomic_set_release(&d->stop, 1);
686 wake_up(&d->done);
687 }
688 return 0;
689}
690
691/**
692 * save_compressed_image - Save the suspend image data after compression.
693 * @handle: Swap map handle to use for saving the image.
694 * @snapshot: Image to read data from.
695 * @nr_to_write: Number of pages to save.
696 */
697static int save_compressed_image(struct swap_map_handle *handle,
698 struct snapshot_handle *snapshot,
699 unsigned int nr_to_write)
700{
701 unsigned int m;
702 int ret = 0;
703 int nr_pages;
704 int err2;
705 struct hib_bio_batch hb;
706 ktime_t start;
707 ktime_t stop;
708 size_t off;
709 unsigned thr, run_threads, nr_threads;
710 unsigned char *page = NULL;
711 struct cmp_data *data = NULL;
712 struct crc_data *crc = NULL;
713
714 hib_init_batch(&hb);
715
716 atomic_set(&compressed_size, 0);
717
718 /*
719 * We'll limit the number of threads for compression to limit memory
720 * footprint.
721 */
722 nr_threads = num_online_cpus() - 1;
723 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
724
725 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
726 if (!page) {
727 pr_err("Failed to allocate %s page\n", hib_comp_algo);
728 ret = -ENOMEM;
729 goto out_clean;
730 }
731
732 data = vzalloc(array_size(nr_threads, sizeof(*data)));
733 if (!data) {
734 pr_err("Failed to allocate %s data\n", hib_comp_algo);
735 ret = -ENOMEM;
736 goto out_clean;
737 }
738
739 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
740 if (!crc) {
741 pr_err("Failed to allocate crc\n");
742 ret = -ENOMEM;
743 goto out_clean;
744 }
745
746 /*
747 * Start the compression threads.
748 */
749 for (thr = 0; thr < nr_threads; thr++) {
750 init_waitqueue_head(&data[thr].go);
751 init_waitqueue_head(&data[thr].done);
752
753 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
754 if (IS_ERR_OR_NULL(data[thr].cc)) {
755 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
756 ret = -EFAULT;
757 goto out_clean;
758 }
759
760 data[thr].thr = kthread_run(compress_threadfn,
761 &data[thr],
762 "image_compress/%u", thr);
763 if (IS_ERR(data[thr].thr)) {
764 data[thr].thr = NULL;
765 pr_err("Cannot start compression threads\n");
766 ret = -ENOMEM;
767 goto out_clean;
768 }
769 }
770
771 /*
772 * Start the CRC32 thread.
773 */
774 init_waitqueue_head(&crc->go);
775 init_waitqueue_head(&crc->done);
776
777 handle->crc32 = 0;
778 crc->crc32 = &handle->crc32;
779 for (thr = 0; thr < nr_threads; thr++) {
780 crc->unc[thr] = data[thr].unc;
781 crc->unc_len[thr] = &data[thr].unc_len;
782 }
783
784 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
785 if (IS_ERR(crc->thr)) {
786 crc->thr = NULL;
787 pr_err("Cannot start CRC32 thread\n");
788 ret = -ENOMEM;
789 goto out_clean;
790 }
791
792 /*
793 * Adjust the number of required free pages after all allocations have
794 * been done. We don't want to run out of pages when writing.
795 */
796 handle->reqd_free_pages = reqd_free_pages();
797
798 pr_info("Using %u thread(s) for %s compression\n", nr_threads, hib_comp_algo);
799 pr_info("Compressing and saving image data (%u pages)...\n",
800 nr_to_write);
801 m = nr_to_write / 10;
802 if (!m)
803 m = 1;
804 nr_pages = 0;
805 start = ktime_get();
806 for (;;) {
807 for (thr = 0; thr < nr_threads; thr++) {
808 for (off = 0; off < UNC_SIZE; off += PAGE_SIZE) {
809 ret = snapshot_read_next(snapshot);
810 if (ret < 0)
811 goto out_finish;
812
813 if (!ret)
814 break;
815
816 memcpy(data[thr].unc + off,
817 data_of(*snapshot), PAGE_SIZE);
818
819 if (!(nr_pages % m))
820 pr_info("Image saving progress: %3d%%\n",
821 nr_pages / m * 10);
822 nr_pages++;
823 }
824 if (!off)
825 break;
826
827 data[thr].unc_len = off;
828
829 atomic_set_release(&data[thr].ready, 1);
830 wake_up(&data[thr].go);
831 }
832
833 if (!thr)
834 break;
835
836 crc->run_threads = thr;
837 atomic_set_release(&crc->ready, 1);
838 wake_up(&crc->go);
839
840 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
841 wait_event(data[thr].done,
842 atomic_read_acquire(&data[thr].stop));
843 atomic_set(&data[thr].stop, 0);
844
845 ret = data[thr].ret;
846
847 if (ret < 0) {
848 pr_err("%s compression failed\n", hib_comp_algo);
849 goto out_finish;
850 }
851
852 if (unlikely(!data[thr].cmp_len ||
853 data[thr].cmp_len >
854 bytes_worst_compress(data[thr].unc_len))) {
855 pr_err("Invalid %s compressed length\n", hib_comp_algo);
856 ret = -1;
857 goto out_finish;
858 }
859
860 *(size_t *)data[thr].cmp = data[thr].cmp_len;
861
862 /*
863 * Given we are writing one page at a time to disk, we
864 * copy that much from the buffer, although the last
865 * bit will likely be smaller than full page. This is
866 * OK - we saved the length of the compressed data, so
867 * any garbage at the end will be discarded when we
868 * read it.
869 */
870 for (off = 0;
871 off < CMP_HEADER + data[thr].cmp_len;
872 off += PAGE_SIZE) {
873 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
874
875 ret = swap_write_page(handle, page, &hb);
876 if (ret)
877 goto out_finish;
878 }
879 }
880
881 wait_event(crc->done, atomic_read_acquire(&crc->stop));
882 atomic_set(&crc->stop, 0);
883 }
884
885out_finish:
886 err2 = hib_wait_io(&hb);
887 stop = ktime_get();
888 if (!ret)
889 ret = err2;
890 if (!ret)
891 pr_info("Image saving done\n");
892 swsusp_show_speed(start, stop, nr_to_write, "Wrote");
893 pr_info("Image size after compression: %d kbytes\n",
894 (atomic_read(&compressed_size) / 1024));
895
896out_clean:
897 hib_finish_batch(&hb);
898 if (crc) {
899 if (crc->thr)
900 kthread_stop(crc->thr);
901 kfree(crc);
902 }
903 if (data) {
904 for (thr = 0; thr < nr_threads; thr++) {
905 if (data[thr].thr)
906 kthread_stop(data[thr].thr);
907 if (data[thr].cc)
908 crypto_free_comp(data[thr].cc);
909 }
910 vfree(data);
911 }
912 if (page) free_page((unsigned long)page);
913
914 return ret;
915}
916
917/**
918 * enough_swap - Make sure we have enough swap to save the image.
919 *
920 * Returns TRUE or FALSE after checking the total amount of swap
921 * space available from the resume partition.
922 */
923
924static int enough_swap(unsigned int nr_pages)
925{
926 unsigned int free_swap = count_swap_pages(root_swap, 1);
927 unsigned int required;
928
929 pr_debug("Free swap pages: %u\n", free_swap);
930
931 required = PAGES_FOR_IO + nr_pages;
932 return free_swap > required;
933}
934
935/**
936 * swsusp_write - Write entire image and metadata.
937 * @flags: flags to pass to the "boot" kernel in the image header
938 *
939 * It is important _NOT_ to umount filesystems at this point. We want
940 * them synced (in case something goes wrong) but we DO not want to mark
941 * filesystem clean: it is not. (And it does not matter, if we resume
942 * correctly, we'll mark system clean, anyway.)
943 */
944
945int swsusp_write(unsigned int flags)
946{
947 struct swap_map_handle handle;
948 struct snapshot_handle snapshot;
949 struct swsusp_info *header;
950 unsigned long pages;
951 int error;
952
953 pages = snapshot_get_image_size();
954 error = get_swap_writer(&handle);
955 if (error) {
956 pr_err("Cannot get swap writer\n");
957 return error;
958 }
959 if (flags & SF_NOCOMPRESS_MODE) {
960 if (!enough_swap(pages)) {
961 pr_err("Not enough free swap\n");
962 error = -ENOSPC;
963 goto out_finish;
964 }
965 }
966 memset(&snapshot, 0, sizeof(struct snapshot_handle));
967 error = snapshot_read_next(&snapshot);
968 if (error < (int)PAGE_SIZE) {
969 if (error >= 0)
970 error = -EFAULT;
971
972 goto out_finish;
973 }
974 header = (struct swsusp_info *)data_of(snapshot);
975 error = swap_write_page(&handle, header, NULL);
976 if (!error) {
977 error = (flags & SF_NOCOMPRESS_MODE) ?
978 save_image(&handle, &snapshot, pages - 1) :
979 save_compressed_image(&handle, &snapshot, pages - 1);
980 }
981out_finish:
982 error = swap_writer_finish(&handle, flags, error);
983 return error;
984}
985
986/*
987 * The following functions allow us to read data using a swap map
988 * in a file-like way.
989 */
990
991static void release_swap_reader(struct swap_map_handle *handle)
992{
993 struct swap_map_page_list *tmp;
994
995 while (handle->maps) {
996 if (handle->maps->map)
997 free_page((unsigned long)handle->maps->map);
998 tmp = handle->maps;
999 handle->maps = handle->maps->next;
1000 kfree(tmp);
1001 }
1002 handle->cur = NULL;
1003}
1004
1005static int get_swap_reader(struct swap_map_handle *handle,
1006 unsigned int *flags_p)
1007{
1008 int error;
1009 struct swap_map_page_list *tmp, *last;
1010 sector_t offset;
1011
1012 *flags_p = swsusp_header->flags;
1013
1014 if (!swsusp_header->image) /* how can this happen? */
1015 return -EINVAL;
1016
1017 handle->cur = NULL;
1018 last = handle->maps = NULL;
1019 offset = swsusp_header->image;
1020 while (offset) {
1021 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
1022 if (!tmp) {
1023 release_swap_reader(handle);
1024 return -ENOMEM;
1025 }
1026 if (!handle->maps)
1027 handle->maps = tmp;
1028 if (last)
1029 last->next = tmp;
1030 last = tmp;
1031
1032 tmp->map = (struct swap_map_page *)
1033 __get_free_page(GFP_NOIO | __GFP_HIGH);
1034 if (!tmp->map) {
1035 release_swap_reader(handle);
1036 return -ENOMEM;
1037 }
1038
1039 error = hib_submit_io(REQ_OP_READ, offset, tmp->map, NULL);
1040 if (error) {
1041 release_swap_reader(handle);
1042 return error;
1043 }
1044 offset = tmp->map->next_swap;
1045 }
1046 handle->k = 0;
1047 handle->cur = handle->maps->map;
1048 return 0;
1049}
1050
1051static int swap_read_page(struct swap_map_handle *handle, void *buf,
1052 struct hib_bio_batch *hb)
1053{
1054 sector_t offset;
1055 int error;
1056 struct swap_map_page_list *tmp;
1057
1058 if (!handle->cur)
1059 return -EINVAL;
1060 offset = handle->cur->entries[handle->k];
1061 if (!offset)
1062 return -EFAULT;
1063 error = hib_submit_io(REQ_OP_READ, offset, buf, hb);
1064 if (error)
1065 return error;
1066 if (++handle->k >= MAP_PAGE_ENTRIES) {
1067 handle->k = 0;
1068 free_page((unsigned long)handle->maps->map);
1069 tmp = handle->maps;
1070 handle->maps = handle->maps->next;
1071 kfree(tmp);
1072 if (!handle->maps)
1073 release_swap_reader(handle);
1074 else
1075 handle->cur = handle->maps->map;
1076 }
1077 return error;
1078}
1079
1080static int swap_reader_finish(struct swap_map_handle *handle)
1081{
1082 release_swap_reader(handle);
1083
1084 return 0;
1085}
1086
1087/**
1088 * load_image - load the image using the swap map handle
1089 * @handle and the snapshot handle @snapshot
1090 * (assume there are @nr_pages pages to load)
1091 */
1092
1093static int load_image(struct swap_map_handle *handle,
1094 struct snapshot_handle *snapshot,
1095 unsigned int nr_to_read)
1096{
1097 unsigned int m;
1098 int ret = 0;
1099 ktime_t start;
1100 ktime_t stop;
1101 struct hib_bio_batch hb;
1102 int err2;
1103 unsigned nr_pages;
1104
1105 hib_init_batch(&hb);
1106
1107 clean_pages_on_read = true;
1108 pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1109 m = nr_to_read / 10;
1110 if (!m)
1111 m = 1;
1112 nr_pages = 0;
1113 start = ktime_get();
1114 for ( ; ; ) {
1115 ret = snapshot_write_next(snapshot);
1116 if (ret <= 0)
1117 break;
1118 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1119 if (ret)
1120 break;
1121 if (snapshot->sync_read)
1122 ret = hib_wait_io(&hb);
1123 if (ret)
1124 break;
1125 if (!(nr_pages % m))
1126 pr_info("Image loading progress: %3d%%\n",
1127 nr_pages / m * 10);
1128 nr_pages++;
1129 }
1130 err2 = hib_wait_io(&hb);
1131 hib_finish_batch(&hb);
1132 stop = ktime_get();
1133 if (!ret)
1134 ret = err2;
1135 if (!ret) {
1136 pr_info("Image loading done\n");
1137 ret = snapshot_write_finalize(snapshot);
1138 if (!ret && !snapshot_image_loaded(snapshot))
1139 ret = -ENODATA;
1140 }
1141 swsusp_show_speed(start, stop, nr_to_read, "Read");
1142 return ret;
1143}
1144
1145/*
1146 * Structure used for data decompression.
1147 */
1148struct dec_data {
1149 struct task_struct *thr; /* thread */
1150 struct crypto_comp *cc; /* crypto compressor stream */
1151 atomic_t ready; /* ready to start flag */
1152 atomic_t stop; /* ready to stop flag */
1153 int ret; /* return code */
1154 wait_queue_head_t go; /* start decompression */
1155 wait_queue_head_t done; /* decompression done */
1156 size_t unc_len; /* uncompressed length */
1157 size_t cmp_len; /* compressed length */
1158 unsigned char unc[UNC_SIZE]; /* uncompressed buffer */
1159 unsigned char cmp[CMP_SIZE]; /* compressed buffer */
1160};
1161
1162/*
1163 * Decompression function that runs in its own thread.
1164 */
1165static int decompress_threadfn(void *data)
1166{
1167 struct dec_data *d = data;
1168 unsigned int unc_len = 0;
1169
1170 while (1) {
1171 wait_event(d->go, atomic_read_acquire(&d->ready) ||
1172 kthread_should_stop());
1173 if (kthread_should_stop()) {
1174 d->thr = NULL;
1175 d->ret = -1;
1176 atomic_set_release(&d->stop, 1);
1177 wake_up(&d->done);
1178 break;
1179 }
1180 atomic_set(&d->ready, 0);
1181
1182 unc_len = UNC_SIZE;
1183 d->ret = crypto_comp_decompress(d->cc, d->cmp + CMP_HEADER, d->cmp_len,
1184 d->unc, &unc_len);
1185 d->unc_len = unc_len;
1186
1187 if (clean_pages_on_decompress)
1188 flush_icache_range((unsigned long)d->unc,
1189 (unsigned long)d->unc + d->unc_len);
1190
1191 atomic_set_release(&d->stop, 1);
1192 wake_up(&d->done);
1193 }
1194 return 0;
1195}
1196
1197/**
1198 * load_compressed_image - Load compressed image data and decompress it.
1199 * @handle: Swap map handle to use for loading data.
1200 * @snapshot: Image to copy uncompressed data into.
1201 * @nr_to_read: Number of pages to load.
1202 */
1203static int load_compressed_image(struct swap_map_handle *handle,
1204 struct snapshot_handle *snapshot,
1205 unsigned int nr_to_read)
1206{
1207 unsigned int m;
1208 int ret = 0;
1209 int eof = 0;
1210 struct hib_bio_batch hb;
1211 ktime_t start;
1212 ktime_t stop;
1213 unsigned nr_pages;
1214 size_t off;
1215 unsigned i, thr, run_threads, nr_threads;
1216 unsigned ring = 0, pg = 0, ring_size = 0,
1217 have = 0, want, need, asked = 0;
1218 unsigned long read_pages = 0;
1219 unsigned char **page = NULL;
1220 struct dec_data *data = NULL;
1221 struct crc_data *crc = NULL;
1222
1223 hib_init_batch(&hb);
1224
1225 /*
1226 * We'll limit the number of threads for decompression to limit memory
1227 * footprint.
1228 */
1229 nr_threads = num_online_cpus() - 1;
1230 nr_threads = clamp_val(nr_threads, 1, CMP_THREADS);
1231
1232 page = vmalloc(array_size(CMP_MAX_RD_PAGES, sizeof(*page)));
1233 if (!page) {
1234 pr_err("Failed to allocate %s page\n", hib_comp_algo);
1235 ret = -ENOMEM;
1236 goto out_clean;
1237 }
1238
1239 data = vzalloc(array_size(nr_threads, sizeof(*data)));
1240 if (!data) {
1241 pr_err("Failed to allocate %s data\n", hib_comp_algo);
1242 ret = -ENOMEM;
1243 goto out_clean;
1244 }
1245
1246 crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1247 if (!crc) {
1248 pr_err("Failed to allocate crc\n");
1249 ret = -ENOMEM;
1250 goto out_clean;
1251 }
1252
1253 clean_pages_on_decompress = true;
1254
1255 /*
1256 * Start the decompression threads.
1257 */
1258 for (thr = 0; thr < nr_threads; thr++) {
1259 init_waitqueue_head(&data[thr].go);
1260 init_waitqueue_head(&data[thr].done);
1261
1262 data[thr].cc = crypto_alloc_comp(hib_comp_algo, 0, 0);
1263 if (IS_ERR_OR_NULL(data[thr].cc)) {
1264 pr_err("Could not allocate comp stream %ld\n", PTR_ERR(data[thr].cc));
1265 ret = -EFAULT;
1266 goto out_clean;
1267 }
1268
1269 data[thr].thr = kthread_run(decompress_threadfn,
1270 &data[thr],
1271 "image_decompress/%u", thr);
1272 if (IS_ERR(data[thr].thr)) {
1273 data[thr].thr = NULL;
1274 pr_err("Cannot start decompression threads\n");
1275 ret = -ENOMEM;
1276 goto out_clean;
1277 }
1278 }
1279
1280 /*
1281 * Start the CRC32 thread.
1282 */
1283 init_waitqueue_head(&crc->go);
1284 init_waitqueue_head(&crc->done);
1285
1286 handle->crc32 = 0;
1287 crc->crc32 = &handle->crc32;
1288 for (thr = 0; thr < nr_threads; thr++) {
1289 crc->unc[thr] = data[thr].unc;
1290 crc->unc_len[thr] = &data[thr].unc_len;
1291 }
1292
1293 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1294 if (IS_ERR(crc->thr)) {
1295 crc->thr = NULL;
1296 pr_err("Cannot start CRC32 thread\n");
1297 ret = -ENOMEM;
1298 goto out_clean;
1299 }
1300
1301 /*
1302 * Set the number of pages for read buffering.
1303 * This is complete guesswork, because we'll only know the real
1304 * picture once prepare_image() is called, which is much later on
1305 * during the image load phase. We'll assume the worst case and
1306 * say that none of the image pages are from high memory.
1307 */
1308 if (low_free_pages() > snapshot_get_image_size())
1309 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1310 read_pages = clamp_val(read_pages, CMP_MIN_RD_PAGES, CMP_MAX_RD_PAGES);
1311
1312 for (i = 0; i < read_pages; i++) {
1313 page[i] = (void *)__get_free_page(i < CMP_PAGES ?
1314 GFP_NOIO | __GFP_HIGH :
1315 GFP_NOIO | __GFP_NOWARN |
1316 __GFP_NORETRY);
1317
1318 if (!page[i]) {
1319 if (i < CMP_PAGES) {
1320 ring_size = i;
1321 pr_err("Failed to allocate %s pages\n", hib_comp_algo);
1322 ret = -ENOMEM;
1323 goto out_clean;
1324 } else {
1325 break;
1326 }
1327 }
1328 }
1329 want = ring_size = i;
1330
1331 pr_info("Using %u thread(s) for %s decompression\n", nr_threads, hib_comp_algo);
1332 pr_info("Loading and decompressing image data (%u pages)...\n",
1333 nr_to_read);
1334 m = nr_to_read / 10;
1335 if (!m)
1336 m = 1;
1337 nr_pages = 0;
1338 start = ktime_get();
1339
1340 ret = snapshot_write_next(snapshot);
1341 if (ret <= 0)
1342 goto out_finish;
1343
1344 for(;;) {
1345 for (i = 0; !eof && i < want; i++) {
1346 ret = swap_read_page(handle, page[ring], &hb);
1347 if (ret) {
1348 /*
1349 * On real read error, finish. On end of data,
1350 * set EOF flag and just exit the read loop.
1351 */
1352 if (handle->cur &&
1353 handle->cur->entries[handle->k]) {
1354 goto out_finish;
1355 } else {
1356 eof = 1;
1357 break;
1358 }
1359 }
1360 if (++ring >= ring_size)
1361 ring = 0;
1362 }
1363 asked += i;
1364 want -= i;
1365
1366 /*
1367 * We are out of data, wait for some more.
1368 */
1369 if (!have) {
1370 if (!asked)
1371 break;
1372
1373 ret = hib_wait_io(&hb);
1374 if (ret)
1375 goto out_finish;
1376 have += asked;
1377 asked = 0;
1378 if (eof)
1379 eof = 2;
1380 }
1381
1382 if (crc->run_threads) {
1383 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1384 atomic_set(&crc->stop, 0);
1385 crc->run_threads = 0;
1386 }
1387
1388 for (thr = 0; have && thr < nr_threads; thr++) {
1389 data[thr].cmp_len = *(size_t *)page[pg];
1390 if (unlikely(!data[thr].cmp_len ||
1391 data[thr].cmp_len >
1392 bytes_worst_compress(UNC_SIZE))) {
1393 pr_err("Invalid %s compressed length\n", hib_comp_algo);
1394 ret = -1;
1395 goto out_finish;
1396 }
1397
1398 need = DIV_ROUND_UP(data[thr].cmp_len + CMP_HEADER,
1399 PAGE_SIZE);
1400 if (need > have) {
1401 if (eof > 1) {
1402 ret = -1;
1403 goto out_finish;
1404 }
1405 break;
1406 }
1407
1408 for (off = 0;
1409 off < CMP_HEADER + data[thr].cmp_len;
1410 off += PAGE_SIZE) {
1411 memcpy(data[thr].cmp + off,
1412 page[pg], PAGE_SIZE);
1413 have--;
1414 want++;
1415 if (++pg >= ring_size)
1416 pg = 0;
1417 }
1418
1419 atomic_set_release(&data[thr].ready, 1);
1420 wake_up(&data[thr].go);
1421 }
1422
1423 /*
1424 * Wait for more data while we are decompressing.
1425 */
1426 if (have < CMP_PAGES && asked) {
1427 ret = hib_wait_io(&hb);
1428 if (ret)
1429 goto out_finish;
1430 have += asked;
1431 asked = 0;
1432 if (eof)
1433 eof = 2;
1434 }
1435
1436 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1437 wait_event(data[thr].done,
1438 atomic_read_acquire(&data[thr].stop));
1439 atomic_set(&data[thr].stop, 0);
1440
1441 ret = data[thr].ret;
1442
1443 if (ret < 0) {
1444 pr_err("%s decompression failed\n", hib_comp_algo);
1445 goto out_finish;
1446 }
1447
1448 if (unlikely(!data[thr].unc_len ||
1449 data[thr].unc_len > UNC_SIZE ||
1450 data[thr].unc_len & (PAGE_SIZE - 1))) {
1451 pr_err("Invalid %s uncompressed length\n", hib_comp_algo);
1452 ret = -1;
1453 goto out_finish;
1454 }
1455
1456 for (off = 0;
1457 off < data[thr].unc_len; off += PAGE_SIZE) {
1458 memcpy(data_of(*snapshot),
1459 data[thr].unc + off, PAGE_SIZE);
1460
1461 if (!(nr_pages % m))
1462 pr_info("Image loading progress: %3d%%\n",
1463 nr_pages / m * 10);
1464 nr_pages++;
1465
1466 ret = snapshot_write_next(snapshot);
1467 if (ret <= 0) {
1468 crc->run_threads = thr + 1;
1469 atomic_set_release(&crc->ready, 1);
1470 wake_up(&crc->go);
1471 goto out_finish;
1472 }
1473 }
1474 }
1475
1476 crc->run_threads = thr;
1477 atomic_set_release(&crc->ready, 1);
1478 wake_up(&crc->go);
1479 }
1480
1481out_finish:
1482 if (crc->run_threads) {
1483 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1484 atomic_set(&crc->stop, 0);
1485 }
1486 stop = ktime_get();
1487 if (!ret) {
1488 pr_info("Image loading done\n");
1489 ret = snapshot_write_finalize(snapshot);
1490 if (!ret && !snapshot_image_loaded(snapshot))
1491 ret = -ENODATA;
1492 if (!ret) {
1493 if (swsusp_header->flags & SF_CRC32_MODE) {
1494 if(handle->crc32 != swsusp_header->crc32) {
1495 pr_err("Invalid image CRC32!\n");
1496 ret = -ENODATA;
1497 }
1498 }
1499 }
1500 }
1501 swsusp_show_speed(start, stop, nr_to_read, "Read");
1502out_clean:
1503 hib_finish_batch(&hb);
1504 for (i = 0; i < ring_size; i++)
1505 free_page((unsigned long)page[i]);
1506 if (crc) {
1507 if (crc->thr)
1508 kthread_stop(crc->thr);
1509 kfree(crc);
1510 }
1511 if (data) {
1512 for (thr = 0; thr < nr_threads; thr++) {
1513 if (data[thr].thr)
1514 kthread_stop(data[thr].thr);
1515 if (data[thr].cc)
1516 crypto_free_comp(data[thr].cc);
1517 }
1518 vfree(data);
1519 }
1520 vfree(page);
1521
1522 return ret;
1523}
1524
1525/**
1526 * swsusp_read - read the hibernation image.
1527 * @flags_p: flags passed by the "frozen" kernel in the image header should
1528 * be written into this memory location
1529 */
1530
1531int swsusp_read(unsigned int *flags_p)
1532{
1533 int error;
1534 struct swap_map_handle handle;
1535 struct snapshot_handle snapshot;
1536 struct swsusp_info *header;
1537
1538 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1539 error = snapshot_write_next(&snapshot);
1540 if (error < (int)PAGE_SIZE)
1541 return error < 0 ? error : -EFAULT;
1542 header = (struct swsusp_info *)data_of(snapshot);
1543 error = get_swap_reader(&handle, flags_p);
1544 if (error)
1545 goto end;
1546 if (!error)
1547 error = swap_read_page(&handle, header, NULL);
1548 if (!error) {
1549 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1550 load_image(&handle, &snapshot, header->pages - 1) :
1551 load_compressed_image(&handle, &snapshot, header->pages - 1);
1552 }
1553 swap_reader_finish(&handle);
1554end:
1555 if (!error)
1556 pr_debug("Image successfully loaded\n");
1557 else
1558 pr_debug("Error %d resuming\n", error);
1559 return error;
1560}
1561
1562static void *swsusp_holder;
1563
1564/**
1565 * swsusp_check - Open the resume device and check for the swsusp signature.
1566 * @exclusive: Open the resume device exclusively.
1567 */
1568
1569int swsusp_check(bool exclusive)
1570{
1571 void *holder = exclusive ? &swsusp_holder : NULL;
1572 int error;
1573
1574 hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
1575 BLK_OPEN_READ, holder, NULL);
1576 if (!IS_ERR(hib_resume_bdev_file)) {
1577 set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
1578 clear_page(swsusp_header);
1579 error = hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1580 swsusp_header, NULL);
1581 if (error)
1582 goto put;
1583
1584 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1585 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1586 swsusp_header_flags = swsusp_header->flags;
1587 /* Reset swap signature now */
1588 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1589 swsusp_resume_block,
1590 swsusp_header, NULL);
1591 } else {
1592 error = -EINVAL;
1593 }
1594 if (!error && swsusp_header->flags & SF_HW_SIG &&
1595 swsusp_header->hw_sig != swsusp_hardware_signature) {
1596 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1597 swsusp_header->hw_sig, swsusp_hardware_signature);
1598 error = -EINVAL;
1599 }
1600
1601put:
1602 if (error)
1603 fput(hib_resume_bdev_file);
1604 else
1605 pr_debug("Image signature found, resuming\n");
1606 } else {
1607 error = PTR_ERR(hib_resume_bdev_file);
1608 }
1609
1610 if (error)
1611 pr_debug("Image not found (code %d)\n", error);
1612
1613 return error;
1614}
1615
1616/**
1617 * swsusp_close - close resume device.
1618 */
1619
1620void swsusp_close(void)
1621{
1622 if (IS_ERR(hib_resume_bdev_file)) {
1623 pr_debug("Image device not initialised\n");
1624 return;
1625 }
1626
1627 fput(hib_resume_bdev_file);
1628}
1629
1630/**
1631 * swsusp_unmark - Unmark swsusp signature in the resume device
1632 */
1633
1634#ifdef CONFIG_SUSPEND
1635int swsusp_unmark(void)
1636{
1637 int error;
1638
1639 hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1640 swsusp_header, NULL);
1641 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1642 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1643 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1644 swsusp_resume_block,
1645 swsusp_header, NULL);
1646 } else {
1647 pr_err("Cannot find swsusp signature!\n");
1648 error = -ENODEV;
1649 }
1650
1651 /*
1652 * We just returned from suspend, we don't need the image any more.
1653 */
1654 free_all_swap_pages(root_swap);
1655
1656 return error;
1657}
1658#endif
1659
1660static int __init swsusp_header_init(void)
1661{
1662 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1663 if (!swsusp_header)
1664 panic("Could not allocate memory for swsusp_header\n");
1665 return 0;
1666}
1667
1668core_initcall(swsusp_header_init);