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