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MIPS: Yosemite, Emma: Fix off-by-two in arcs_cmdline buffer size check
[linux-2.6/linux-mips.git] / kernel / power / swap.c
blob11a594c4ba251227c6fc25b62c307747356fccfc
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 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/buffer_head.h>
22 #include <linux/bio.h>
23 #include <linux/blkdev.h>
24 #include <linux/swap.h>
25 #include <linux/swapops.h>
26 #include <linux/pm.h>
27 #include <linux/slab.h>
28 #include <linux/lzo.h>
29 #include <linux/vmalloc.h>
30 #include <linux/cpumask.h>
31 #include <linux/atomic.h>
32 #include <linux/kthread.h>
33 #include <linux/crc32.h>
34
35 #include "power.h"
36
37 #define HIBERNATE_SIG "S1SUSPEND"
38
39 /*
40 * The swap map is a data structure used for keeping track of each page
41 * written to a swap partition. It consists of many swap_map_page
42 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
43 * These structures are stored on the swap and linked together with the
44 * help of the .next_swap member.
45 *
46 * The swap map is created during suspend. The swap map pages are
47 * allocated and populated one at a time, so we only need one memory
48 * page to set up the entire structure.
49 *
50 * During resume we pick up all swap_map_page structures into a list.
51 */
52
53 #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1)
54
55 struct swap_map_page {
56 sector_t entries[MAP_PAGE_ENTRIES];
57 sector_t next_swap;
58 };
59
60 struct swap_map_page_list {
61 struct swap_map_page *map;
62 struct swap_map_page_list *next;
63 };
64
65 /**
66 * The swap_map_handle structure is used for handling swap in
67 * a file-alike way
68 */
69
70 struct swap_map_handle {
71 struct swap_map_page *cur;
72 struct swap_map_page_list *maps;
73 sector_t cur_swap;
74 sector_t first_sector;
75 unsigned int k;
76 unsigned long nr_free_pages, written;
77 u32 crc32;
78 };
79
80 struct swsusp_header {
81 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
82 sizeof(u32)];
83 u32 crc32;
84 sector_t image;
85 unsigned int flags; /* Flags to pass to the "boot" kernel */
86 char orig_sig[10];
87 char sig[10];
88 } __attribute__((packed));
89
90 static struct swsusp_header *swsusp_header;
91
92 /**
93 * The following functions are used for tracing the allocated
94 * swap pages, so that they can be freed in case of an error.
95 */
96
97 struct swsusp_extent {
98 struct rb_node node;
99 unsigned long start;
100 unsigned long end;
101 };
102
103 static struct rb_root swsusp_extents = RB_ROOT;
104
105 static int swsusp_extents_insert(unsigned long swap_offset)
106 {
107 struct rb_node **new = &(swsusp_extents.rb_node);
108 struct rb_node *parent = NULL;
109 struct swsusp_extent *ext;
110
111 /* Figure out where to put the new node */
112 while (*new) {
113 ext = container_of(*new, struct swsusp_extent, node);
114 parent = *new;
115 if (swap_offset < ext->start) {
116 /* Try to merge */
117 if (swap_offset == ext->start - 1) {
118 ext->start--;
119 return 0;
120 }
121 new = &((*new)->rb_left);
122 } else if (swap_offset > ext->end) {
123 /* Try to merge */
124 if (swap_offset == ext->end + 1) {
125 ext->end++;
126 return 0;
127 }
128 new = &((*new)->rb_right);
129 } else {
130 /* It already is in the tree */
131 return -EINVAL;
132 }
133 }
134 /* Add the new node and rebalance the tree. */
135 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
136 if (!ext)
137 return -ENOMEM;
138
139 ext->start = swap_offset;
140 ext->end = swap_offset;
141 rb_link_node(&ext->node, parent, new);
142 rb_insert_color(&ext->node, &swsusp_extents);
143 return 0;
144 }
145
146 /**
147 * alloc_swapdev_block - allocate a swap page and register that it has
148 * been allocated, so that it can be freed in case of an error.
149 */
150
151 sector_t alloc_swapdev_block(int swap)
152 {
153 unsigned long offset;
154
155 offset = swp_offset(get_swap_page_of_type(swap));
156 if (offset) {
157 if (swsusp_extents_insert(offset))
158 swap_free(swp_entry(swap, offset));
159 else
160 return swapdev_block(swap, offset);
161 }
162 return 0;
163 }
164
165 /**
166 * free_all_swap_pages - free swap pages allocated for saving image data.
167 * It also frees the extents used to register which swap entries had been
168 * allocated.
169 */
170
171 void free_all_swap_pages(int swap)
172 {
173 struct rb_node *node;
174
175 while ((node = swsusp_extents.rb_node)) {
176 struct swsusp_extent *ext;
177 unsigned long offset;
178
179 ext = container_of(node, struct swsusp_extent, node);
180 rb_erase(node, &swsusp_extents);
181 for (offset = ext->start; offset <= ext->end; offset++)
182 swap_free(swp_entry(swap, offset));
183
184 kfree(ext);
185 }
186 }
187
188 int swsusp_swap_in_use(void)
189 {
190 return (swsusp_extents.rb_node != NULL);
191 }
192
193 /*
194 * General things
195 */
196
197 static unsigned short root_swap = 0xffff;
198 struct block_device *hib_resume_bdev;
199
200 /*
201 * Saving part
202 */
203
204 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
205 {
206 int error;
207
208 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL);
209 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
210 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
211 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
212 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
213 swsusp_header->image = handle->first_sector;
214 swsusp_header->flags = flags;
215 if (flags & SF_CRC32_MODE)
216 swsusp_header->crc32 = handle->crc32;
217 error = hib_bio_write_page(swsusp_resume_block,
218 swsusp_header, NULL);
219 } else {
220 printk(KERN_ERR "PM: Swap header not found!\n");
221 error = -ENODEV;
222 }
223 return error;
224 }
225
226 /**
227 * swsusp_swap_check - check if the resume device is a swap device
228 * and get its index (if so)
229 *
230 * This is called before saving image
231 */
232 static int swsusp_swap_check(void)
233 {
234 int res;
235
236 res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
237 &hib_resume_bdev);
238 if (res < 0)
239 return res;
240
241 root_swap = res;
242 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
243 if (res)
244 return res;
245
246 res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
247 if (res < 0)
248 blkdev_put(hib_resume_bdev, FMODE_WRITE);
249
250 return res;
251 }
252
253 /**
254 * write_page - Write one page to given swap location.
255 * @buf: Address we're writing.
256 * @offset: Offset of the swap page we're writing to.
257 * @bio_chain: Link the next write BIO here
258 */
259
260 static int write_page(void *buf, sector_t offset, struct bio **bio_chain)
261 {
262 void *src;
263 int ret;
264
265 if (!offset)
266 return -ENOSPC;
267
268 if (bio_chain) {
269 src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
270 if (src) {
271 copy_page(src, buf);
272 } else {
273 ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */
274 if (ret)
275 return ret;
276 src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
277 if (src) {
278 copy_page(src, buf);
279 } else {
280 WARN_ON_ONCE(1);
281 bio_chain = NULL; /* Go synchronous */
282 src = buf;
283 }
284 }
285 } else {
286 src = buf;
287 }
288 return hib_bio_write_page(offset, src, bio_chain);
289 }
290
291 static void release_swap_writer(struct swap_map_handle *handle)
292 {
293 if (handle->cur)
294 free_page((unsigned long)handle->cur);
295 handle->cur = NULL;
296 }
297
298 static int get_swap_writer(struct swap_map_handle *handle)
299 {
300 int ret;
301
302 ret = swsusp_swap_check();
303 if (ret) {
304 if (ret != -ENOSPC)
305 printk(KERN_ERR "PM: Cannot find swap device, try "
306 "swapon -a.\n");
307 return ret;
308 }
309 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
310 if (!handle->cur) {
311 ret = -ENOMEM;
312 goto err_close;
313 }
314 handle->cur_swap = alloc_swapdev_block(root_swap);
315 if (!handle->cur_swap) {
316 ret = -ENOSPC;
317 goto err_rel;
318 }
319 handle->k = 0;
320 handle->nr_free_pages = nr_free_pages() >> 1;
321 handle->written = 0;
322 handle->first_sector = handle->cur_swap;
323 return 0;
324 err_rel:
325 release_swap_writer(handle);
326 err_close:
327 swsusp_close(FMODE_WRITE);
328 return ret;
329 }
330
331 static int swap_write_page(struct swap_map_handle *handle, void *buf,
332 struct bio **bio_chain)
333 {
334 int error = 0;
335 sector_t offset;
336
337 if (!handle->cur)
338 return -EINVAL;
339 offset = alloc_swapdev_block(root_swap);
340 error = write_page(buf, offset, bio_chain);
341 if (error)
342 return error;
343 handle->cur->entries[handle->k++] = offset;
344 if (handle->k >= MAP_PAGE_ENTRIES) {
345 offset = alloc_swapdev_block(root_swap);
346 if (!offset)
347 return -ENOSPC;
348 handle->cur->next_swap = offset;
349 error = write_page(handle->cur, handle->cur_swap, bio_chain);
350 if (error)
351 goto out;
352 clear_page(handle->cur);
353 handle->cur_swap = offset;
354 handle->k = 0;
355 }
356 if (bio_chain && ++handle->written > handle->nr_free_pages) {
357 error = hib_wait_on_bio_chain(bio_chain);
358 if (error)
359 goto out;
360 handle->written = 0;
361 }
362 out:
363 return error;
364 }
365
366 static int flush_swap_writer(struct swap_map_handle *handle)
367 {
368 if (handle->cur && handle->cur_swap)
369 return write_page(handle->cur, handle->cur_swap, NULL);
370 else
371 return -EINVAL;
372 }
373
374 static int swap_writer_finish(struct swap_map_handle *handle,
375 unsigned int flags, int error)
376 {
377 if (!error) {
378 flush_swap_writer(handle);
379 printk(KERN_INFO "PM: S");
380 error = mark_swapfiles(handle, flags);
381 printk("|\n");
382 }
383
384 if (error)
385 free_all_swap_pages(root_swap);
386 release_swap_writer(handle);
387 swsusp_close(FMODE_WRITE);
388
389 return error;
390 }
391
392 /* We need to remember how much compressed data we need to read. */
393 #define LZO_HEADER sizeof(size_t)
394
395 /* Number of pages/bytes we'll compress at one time. */
396 #define LZO_UNC_PAGES 32
397 #define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE)
398
399 /* Number of pages/bytes we need for compressed data (worst case). */
400 #define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
401 LZO_HEADER, PAGE_SIZE)
402 #define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE)
403
404 /* Maximum number of threads for compression/decompression. */
405 #define LZO_THREADS 3
406
407 /* Maximum number of pages for read buffering. */
408 #define LZO_READ_PAGES (MAP_PAGE_ENTRIES * 8)
409
410
411 /**
412 * save_image - save the suspend image data
413 */
414
415 static int save_image(struct swap_map_handle *handle,
416 struct snapshot_handle *snapshot,
417 unsigned int nr_to_write)
418 {
419 unsigned int m;
420 int ret;
421 int nr_pages;
422 int err2;
423 struct bio *bio;
424 struct timeval start;
425 struct timeval stop;
426
427 printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ",
428 nr_to_write);
429 m = nr_to_write / 100;
430 if (!m)
431 m = 1;
432 nr_pages = 0;
433 bio = NULL;
434 do_gettimeofday(&start);
435 while (1) {
436 ret = snapshot_read_next(snapshot);
437 if (ret <= 0)
438 break;
439 ret = swap_write_page(handle, data_of(*snapshot), &bio);
440 if (ret)
441 break;
442 if (!(nr_pages % m))
443 printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m);
444 nr_pages++;
445 }
446 err2 = hib_wait_on_bio_chain(&bio);
447 do_gettimeofday(&stop);
448 if (!ret)
449 ret = err2;
450 if (!ret)
451 printk(KERN_CONT "\b\b\b\bdone\n");
452 else
453 printk(KERN_CONT "\n");
454 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
455 return ret;
456 }
457
458 /**
459 * Structure used for CRC32.
460 */
461 struct crc_data {
462 struct task_struct *thr; /* thread */
463 atomic_t ready; /* ready to start flag */
464 atomic_t stop; /* ready to stop flag */
465 unsigned run_threads; /* nr current threads */
466 wait_queue_head_t go; /* start crc update */
467 wait_queue_head_t done; /* crc update done */
468 u32 *crc32; /* points to handle's crc32 */
469 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */
470 unsigned char *unc[LZO_THREADS]; /* uncompressed data */
471 };
472
473 /**
474 * CRC32 update function that runs in its own thread.
475 */
476 static int crc32_threadfn(void *data)
477 {
478 struct crc_data *d = data;
479 unsigned i;
480
481 while (1) {
482 wait_event(d->go, atomic_read(&d->ready) ||
483 kthread_should_stop());
484 if (kthread_should_stop()) {
485 d->thr = NULL;
486 atomic_set(&d->stop, 1);
487 wake_up(&d->done);
488 break;
489 }
490 atomic_set(&d->ready, 0);
491
492 for (i = 0; i < d->run_threads; i++)
493 *d->crc32 = crc32_le(*d->crc32,
494 d->unc[i], *d->unc_len[i]);
495 atomic_set(&d->stop, 1);
496 wake_up(&d->done);
497 }
498 return 0;
499 }
500 /**
501 * Structure used for LZO data compression.
502 */
503 struct cmp_data {
504 struct task_struct *thr; /* thread */
505 atomic_t ready; /* ready to start flag */
506 atomic_t stop; /* ready to stop flag */
507 int ret; /* return code */
508 wait_queue_head_t go; /* start compression */
509 wait_queue_head_t done; /* compression done */
510 size_t unc_len; /* uncompressed length */
511 size_t cmp_len; /* compressed length */
512 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
513 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
514 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */
515 };
516
517 /**
518 * Compression function that runs in its own thread.
519 */
520 static int lzo_compress_threadfn(void *data)
521 {
522 struct cmp_data *d = data;
523
524 while (1) {
525 wait_event(d->go, atomic_read(&d->ready) ||
526 kthread_should_stop());
527 if (kthread_should_stop()) {
528 d->thr = NULL;
529 d->ret = -1;
530 atomic_set(&d->stop, 1);
531 wake_up(&d->done);
532 break;
533 }
534 atomic_set(&d->ready, 0);
535
536 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
537 d->cmp + LZO_HEADER, &d->cmp_len,
538 d->wrk);
539 atomic_set(&d->stop, 1);
540 wake_up(&d->done);
541 }
542 return 0;
543 }
544
545 /**
546 * save_image_lzo - Save the suspend image data compressed with LZO.
547 * @handle: Swap mam handle to use for saving the image.
548 * @snapshot: Image to read data from.
549 * @nr_to_write: Number of pages to save.
550 */
551 static int save_image_lzo(struct swap_map_handle *handle,
552 struct snapshot_handle *snapshot,
553 unsigned int nr_to_write)
554 {
555 unsigned int m;
556 int ret = 0;
557 int nr_pages;
558 int err2;
559 struct bio *bio;
560 struct timeval start;
561 struct timeval stop;
562 size_t off;
563 unsigned thr, run_threads, nr_threads;
564 unsigned char *page = NULL;
565 struct cmp_data *data = NULL;
566 struct crc_data *crc = NULL;
567
568 /*
569 * We'll limit the number of threads for compression to limit memory
570 * footprint.
571 */
572 nr_threads = num_online_cpus() - 1;
573 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
574
575 page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
576 if (!page) {
577 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
578 ret = -ENOMEM;
579 goto out_clean;
580 }
581
582 data = vmalloc(sizeof(*data) * nr_threads);
583 if (!data) {
584 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
585 ret = -ENOMEM;
586 goto out_clean;
587 }
588 for (thr = 0; thr < nr_threads; thr++)
589 memset(&data[thr], 0, offsetof(struct cmp_data, go));
590
591 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
592 if (!crc) {
593 printk(KERN_ERR "PM: Failed to allocate crc\n");
594 ret = -ENOMEM;
595 goto out_clean;
596 }
597 memset(crc, 0, offsetof(struct crc_data, go));
598
599 /*
600 * Start the compression threads.
601 */
602 for (thr = 0; thr < nr_threads; thr++) {
603 init_waitqueue_head(&data[thr].go);
604 init_waitqueue_head(&data[thr].done);
605
606 data[thr].thr = kthread_run(lzo_compress_threadfn,
607 &data[thr],
608 "image_compress/%u", thr);
609 if (IS_ERR(data[thr].thr)) {
610 data[thr].thr = NULL;
611 printk(KERN_ERR
612 "PM: Cannot start compression threads\n");
613 ret = -ENOMEM;
614 goto out_clean;
615 }
616 }
617
618 /*
619 * Adjust number of free pages after all allocations have been done.
620 * We don't want to run out of pages when writing.
621 */
622 handle->nr_free_pages = nr_free_pages() >> 1;
623
624 /*
625 * Start the CRC32 thread.
626 */
627 init_waitqueue_head(&crc->go);
628 init_waitqueue_head(&crc->done);
629
630 handle->crc32 = 0;
631 crc->crc32 = &handle->crc32;
632 for (thr = 0; thr < nr_threads; thr++) {
633 crc->unc[thr] = data[thr].unc;
634 crc->unc_len[thr] = &data[thr].unc_len;
635 }
636
637 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
638 if (IS_ERR(crc->thr)) {
639 crc->thr = NULL;
640 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
641 ret = -ENOMEM;
642 goto out_clean;
643 }
644
645 printk(KERN_INFO
646 "PM: Using %u thread(s) for compression.\n"
647 "PM: Compressing and saving image data (%u pages) ... ",
648 nr_threads, nr_to_write);
649 m = nr_to_write / 100;
650 if (!m)
651 m = 1;
652 nr_pages = 0;
653 bio = NULL;
654 do_gettimeofday(&start);
655 for (;;) {
656 for (thr = 0; thr < nr_threads; thr++) {
657 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
658 ret = snapshot_read_next(snapshot);
659 if (ret < 0)
660 goto out_finish;
661
662 if (!ret)
663 break;
664
665 memcpy(data[thr].unc + off,
666 data_of(*snapshot), PAGE_SIZE);
667
668 if (!(nr_pages % m))
669 printk(KERN_CONT "\b\b\b\b%3d%%",
670 nr_pages / m);
671 nr_pages++;
672 }
673 if (!off)
674 break;
675
676 data[thr].unc_len = off;
677
678 atomic_set(&data[thr].ready, 1);
679 wake_up(&data[thr].go);
680 }
681
682 if (!thr)
683 break;
684
685 crc->run_threads = thr;
686 atomic_set(&crc->ready, 1);
687 wake_up(&crc->go);
688
689 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
690 wait_event(data[thr].done,
691 atomic_read(&data[thr].stop));
692 atomic_set(&data[thr].stop, 0);
693
694 ret = data[thr].ret;
695
696 if (ret < 0) {
697 printk(KERN_ERR "PM: LZO compression failed\n");
698 goto out_finish;
699 }
700
701 if (unlikely(!data[thr].cmp_len ||
702 data[thr].cmp_len >
703 lzo1x_worst_compress(data[thr].unc_len))) {
704 printk(KERN_ERR
705 "PM: Invalid LZO compressed length\n");
706 ret = -1;
707 goto out_finish;
708 }
709
710 *(size_t *)data[thr].cmp = data[thr].cmp_len;
711
712 /*
713 * Given we are writing one page at a time to disk, we
714 * copy that much from the buffer, although the last
715 * bit will likely be smaller than full page. This is
716 * OK - we saved the length of the compressed data, so
717 * any garbage at the end will be discarded when we
718 * read it.
719 */
720 for (off = 0;
721 off < LZO_HEADER + data[thr].cmp_len;
722 off += PAGE_SIZE) {
723 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
724
725 ret = swap_write_page(handle, page, &bio);
726 if (ret)
727 goto out_finish;
728 }
729 }
730
731 wait_event(crc->done, atomic_read(&crc->stop));
732 atomic_set(&crc->stop, 0);
733 }
734
735 out_finish:
736 err2 = hib_wait_on_bio_chain(&bio);
737 do_gettimeofday(&stop);
738 if (!ret)
739 ret = err2;
740 if (!ret) {
741 printk(KERN_CONT "\b\b\b\bdone\n");
742 } else {
743 printk(KERN_CONT "\n");
744 }
745 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
746 out_clean:
747 if (crc) {
748 if (crc->thr)
749 kthread_stop(crc->thr);
750 kfree(crc);
751 }
752 if (data) {
753 for (thr = 0; thr < nr_threads; thr++)
754 if (data[thr].thr)
755 kthread_stop(data[thr].thr);
756 vfree(data);
757 }
758 if (page) free_page((unsigned long)page);
759
760 return ret;
761 }
762
763 /**
764 * enough_swap - Make sure we have enough swap to save the image.
765 *
766 * Returns TRUE or FALSE after checking the total amount of swap
767 * space avaiable from the resume partition.
768 */
769
770 static int enough_swap(unsigned int nr_pages, unsigned int flags)
771 {
772 unsigned int free_swap = count_swap_pages(root_swap, 1);
773 unsigned int required;
774
775 pr_debug("PM: Free swap pages: %u\n", free_swap);
776
777 required = PAGES_FOR_IO + ((flags & SF_NOCOMPRESS_MODE) ?
778 nr_pages : (nr_pages * LZO_CMP_PAGES) / LZO_UNC_PAGES + 1);
779 return free_swap > required;
780 }
781
782 /**
783 * swsusp_write - Write entire image and metadata.
784 * @flags: flags to pass to the "boot" kernel in the image header
785 *
786 * It is important _NOT_ to umount filesystems at this point. We want
787 * them synced (in case something goes wrong) but we DO not want to mark
788 * filesystem clean: it is not. (And it does not matter, if we resume
789 * correctly, we'll mark system clean, anyway.)
790 */
791
792 int swsusp_write(unsigned int flags)
793 {
794 struct swap_map_handle handle;
795 struct snapshot_handle snapshot;
796 struct swsusp_info *header;
797 unsigned long pages;
798 int error;
799
800 pages = snapshot_get_image_size();
801 error = get_swap_writer(&handle);
802 if (error) {
803 printk(KERN_ERR "PM: Cannot get swap writer\n");
804 return error;
805 }
806 if (!enough_swap(pages, flags)) {
807 printk(KERN_ERR "PM: Not enough free swap\n");
808 error = -ENOSPC;
809 goto out_finish;
810 }
811 memset(&snapshot, 0, sizeof(struct snapshot_handle));
812 error = snapshot_read_next(&snapshot);
813 if (error < PAGE_SIZE) {
814 if (error >= 0)
815 error = -EFAULT;
816
817 goto out_finish;
818 }
819 header = (struct swsusp_info *)data_of(snapshot);
820 error = swap_write_page(&handle, header, NULL);
821 if (!error) {
822 error = (flags & SF_NOCOMPRESS_MODE) ?
823 save_image(&handle, &snapshot, pages - 1) :
824 save_image_lzo(&handle, &snapshot, pages - 1);
825 }
826 out_finish:
827 error = swap_writer_finish(&handle, flags, error);
828 return error;
829 }
830
831 /**
832 * The following functions allow us to read data using a swap map
833 * in a file-alike way
834 */
835
836 static void release_swap_reader(struct swap_map_handle *handle)
837 {
838 struct swap_map_page_list *tmp;
839
840 while (handle->maps) {
841 if (handle->maps->map)
842 free_page((unsigned long)handle->maps->map);
843 tmp = handle->maps;
844 handle->maps = handle->maps->next;
845 kfree(tmp);
846 }
847 handle->cur = NULL;
848 }
849
850 static int get_swap_reader(struct swap_map_handle *handle,
851 unsigned int *flags_p)
852 {
853 int error;
854 struct swap_map_page_list *tmp, *last;
855 sector_t offset;
856
857 *flags_p = swsusp_header->flags;
858
859 if (!swsusp_header->image) /* how can this happen? */
860 return -EINVAL;
861
862 handle->cur = NULL;
863 last = handle->maps = NULL;
864 offset = swsusp_header->image;
865 while (offset) {
866 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
867 if (!tmp) {
868 release_swap_reader(handle);
869 return -ENOMEM;
870 }
871 memset(tmp, 0, sizeof(*tmp));
872 if (!handle->maps)
873 handle->maps = tmp;
874 if (last)
875 last->next = tmp;
876 last = tmp;
877
878 tmp->map = (struct swap_map_page *)
879 __get_free_page(__GFP_WAIT | __GFP_HIGH);
880 if (!tmp->map) {
881 release_swap_reader(handle);
882 return -ENOMEM;
883 }
884
885 error = hib_bio_read_page(offset, tmp->map, NULL);
886 if (error) {
887 release_swap_reader(handle);
888 return error;
889 }
890 offset = tmp->map->next_swap;
891 }
892 handle->k = 0;
893 handle->cur = handle->maps->map;
894 return 0;
895 }
896
897 static int swap_read_page(struct swap_map_handle *handle, void *buf,
898 struct bio **bio_chain)
899 {
900 sector_t offset;
901 int error;
902 struct swap_map_page_list *tmp;
903
904 if (!handle->cur)
905 return -EINVAL;
906 offset = handle->cur->entries[handle->k];
907 if (!offset)
908 return -EFAULT;
909 error = hib_bio_read_page(offset, buf, bio_chain);
910 if (error)
911 return error;
912 if (++handle->k >= MAP_PAGE_ENTRIES) {
913 handle->k = 0;
914 free_page((unsigned long)handle->maps->map);
915 tmp = handle->maps;
916 handle->maps = handle->maps->next;
917 kfree(tmp);
918 if (!handle->maps)
919 release_swap_reader(handle);
920 else
921 handle->cur = handle->maps->map;
922 }
923 return error;
924 }
925
926 static int swap_reader_finish(struct swap_map_handle *handle)
927 {
928 release_swap_reader(handle);
929
930 return 0;
931 }
932
933 /**
934 * load_image - load the image using the swap map handle
935 * @handle and the snapshot handle @snapshot
936 * (assume there are @nr_pages pages to load)
937 */
938
939 static int load_image(struct swap_map_handle *handle,
940 struct snapshot_handle *snapshot,
941 unsigned int nr_to_read)
942 {
943 unsigned int m;
944 int ret = 0;
945 struct timeval start;
946 struct timeval stop;
947 struct bio *bio;
948 int err2;
949 unsigned nr_pages;
950
951 printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ",
952 nr_to_read);
953 m = nr_to_read / 100;
954 if (!m)
955 m = 1;
956 nr_pages = 0;
957 bio = NULL;
958 do_gettimeofday(&start);
959 for ( ; ; ) {
960 ret = snapshot_write_next(snapshot);
961 if (ret <= 0)
962 break;
963 ret = swap_read_page(handle, data_of(*snapshot), &bio);
964 if (ret)
965 break;
966 if (snapshot->sync_read)
967 ret = hib_wait_on_bio_chain(&bio);
968 if (ret)
969 break;
970 if (!(nr_pages % m))
971 printk("\b\b\b\b%3d%%", nr_pages / m);
972 nr_pages++;
973 }
974 err2 = hib_wait_on_bio_chain(&bio);
975 do_gettimeofday(&stop);
976 if (!ret)
977 ret = err2;
978 if (!ret) {
979 printk("\b\b\b\bdone\n");
980 snapshot_write_finalize(snapshot);
981 if (!snapshot_image_loaded(snapshot))
982 ret = -ENODATA;
983 } else
984 printk("\n");
985 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
986 return ret;
987 }
988
989 /**
990 * Structure used for LZO data decompression.
991 */
992 struct dec_data {
993 struct task_struct *thr; /* thread */
994 atomic_t ready; /* ready to start flag */
995 atomic_t stop; /* ready to stop flag */
996 int ret; /* return code */
997 wait_queue_head_t go; /* start decompression */
998 wait_queue_head_t done; /* decompression done */
999 size_t unc_len; /* uncompressed length */
1000 size_t cmp_len; /* compressed length */
1001 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */
1002 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */
1003 };
1004
1005 /**
1006 * Deompression function that runs in its own thread.
1007 */
1008 static int lzo_decompress_threadfn(void *data)
1009 {
1010 struct dec_data *d = data;
1011
1012 while (1) {
1013 wait_event(d->go, atomic_read(&d->ready) ||
1014 kthread_should_stop());
1015 if (kthread_should_stop()) {
1016 d->thr = NULL;
1017 d->ret = -1;
1018 atomic_set(&d->stop, 1);
1019 wake_up(&d->done);
1020 break;
1021 }
1022 atomic_set(&d->ready, 0);
1023
1024 d->unc_len = LZO_UNC_SIZE;
1025 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1026 d->unc, &d->unc_len);
1027 atomic_set(&d->stop, 1);
1028 wake_up(&d->done);
1029 }
1030 return 0;
1031 }
1032
1033 /**
1034 * load_image_lzo - Load compressed image data and decompress them with LZO.
1035 * @handle: Swap map handle to use for loading data.
1036 * @snapshot: Image to copy uncompressed data into.
1037 * @nr_to_read: Number of pages to load.
1038 */
1039 static int load_image_lzo(struct swap_map_handle *handle,
1040 struct snapshot_handle *snapshot,
1041 unsigned int nr_to_read)
1042 {
1043 unsigned int m;
1044 int ret = 0;
1045 int eof = 0;
1046 struct bio *bio;
1047 struct timeval start;
1048 struct timeval stop;
1049 unsigned nr_pages;
1050 size_t off;
1051 unsigned i, thr, run_threads, nr_threads;
1052 unsigned ring = 0, pg = 0, ring_size = 0,
1053 have = 0, want, need, asked = 0;
1054 unsigned long read_pages;
1055 unsigned char **page = NULL;
1056 struct dec_data *data = NULL;
1057 struct crc_data *crc = NULL;
1058
1059 /*
1060 * We'll limit the number of threads for decompression to limit memory
1061 * footprint.
1062 */
1063 nr_threads = num_online_cpus() - 1;
1064 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1065
1066 page = vmalloc(sizeof(*page) * LZO_READ_PAGES);
1067 if (!page) {
1068 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1069 ret = -ENOMEM;
1070 goto out_clean;
1071 }
1072
1073 data = vmalloc(sizeof(*data) * nr_threads);
1074 if (!data) {
1075 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1076 ret = -ENOMEM;
1077 goto out_clean;
1078 }
1079 for (thr = 0; thr < nr_threads; thr++)
1080 memset(&data[thr], 0, offsetof(struct dec_data, go));
1081
1082 crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1083 if (!crc) {
1084 printk(KERN_ERR "PM: Failed to allocate crc\n");
1085 ret = -ENOMEM;
1086 goto out_clean;
1087 }
1088 memset(crc, 0, offsetof(struct crc_data, go));
1089
1090 /*
1091 * Start the decompression threads.
1092 */
1093 for (thr = 0; thr < nr_threads; thr++) {
1094 init_waitqueue_head(&data[thr].go);
1095 init_waitqueue_head(&data[thr].done);
1096
1097 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1098 &data[thr],
1099 "image_decompress/%u", thr);
1100 if (IS_ERR(data[thr].thr)) {
1101 data[thr].thr = NULL;
1102 printk(KERN_ERR
1103 "PM: Cannot start decompression threads\n");
1104 ret = -ENOMEM;
1105 goto out_clean;
1106 }
1107 }
1108
1109 /*
1110 * Start the CRC32 thread.
1111 */
1112 init_waitqueue_head(&crc->go);
1113 init_waitqueue_head(&crc->done);
1114
1115 handle->crc32 = 0;
1116 crc->crc32 = &handle->crc32;
1117 for (thr = 0; thr < nr_threads; thr++) {
1118 crc->unc[thr] = data[thr].unc;
1119 crc->unc_len[thr] = &data[thr].unc_len;
1120 }
1121
1122 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1123 if (IS_ERR(crc->thr)) {
1124 crc->thr = NULL;
1125 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1126 ret = -ENOMEM;
1127 goto out_clean;
1128 }
1129
1130 /*
1131 * Adjust number of pages for read buffering, in case we are short.
1132 */
1133 read_pages = (nr_free_pages() - snapshot_get_image_size()) >> 1;
1134 read_pages = clamp_val(read_pages, LZO_CMP_PAGES, LZO_READ_PAGES);
1135
1136 for (i = 0; i < read_pages; i++) {
1137 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1138 __GFP_WAIT | __GFP_HIGH :
1139 __GFP_WAIT);
1140 if (!page[i]) {
1141 if (i < LZO_CMP_PAGES) {
1142 ring_size = i;
1143 printk(KERN_ERR
1144 "PM: Failed to allocate LZO pages\n");
1145 ret = -ENOMEM;
1146 goto out_clean;
1147 } else {
1148 break;
1149 }
1150 }
1151 }
1152 want = ring_size = i;
1153
1154 printk(KERN_INFO
1155 "PM: Using %u thread(s) for decompression.\n"
1156 "PM: Loading and decompressing image data (%u pages) ... ",
1157 nr_threads, nr_to_read);
1158 m = nr_to_read / 100;
1159 if (!m)
1160 m = 1;
1161 nr_pages = 0;
1162 bio = NULL;
1163 do_gettimeofday(&start);
1164
1165 ret = snapshot_write_next(snapshot);
1166 if (ret <= 0)
1167 goto out_finish;
1168
1169 for(;;) {
1170 for (i = 0; !eof && i < want; i++) {
1171 ret = swap_read_page(handle, page[ring], &bio);
1172 if (ret) {
1173 /*
1174 * On real read error, finish. On end of data,
1175 * set EOF flag and just exit the read loop.
1176 */
1177 if (handle->cur &&
1178 handle->cur->entries[handle->k]) {
1179 goto out_finish;
1180 } else {
1181 eof = 1;
1182 break;
1183 }
1184 }
1185 if (++ring >= ring_size)
1186 ring = 0;
1187 }
1188 asked += i;
1189 want -= i;
1190
1191 /*
1192 * We are out of data, wait for some more.
1193 */
1194 if (!have) {
1195 if (!asked)
1196 break;
1197
1198 ret = hib_wait_on_bio_chain(&bio);
1199 if (ret)
1200 goto out_finish;
1201 have += asked;
1202 asked = 0;
1203 if (eof)
1204 eof = 2;
1205 }
1206
1207 if (crc->run_threads) {
1208 wait_event(crc->done, atomic_read(&crc->stop));
1209 atomic_set(&crc->stop, 0);
1210 crc->run_threads = 0;
1211 }
1212
1213 for (thr = 0; have && thr < nr_threads; thr++) {
1214 data[thr].cmp_len = *(size_t *)page[pg];
1215 if (unlikely(!data[thr].cmp_len ||
1216 data[thr].cmp_len >
1217 lzo1x_worst_compress(LZO_UNC_SIZE))) {
1218 printk(KERN_ERR
1219 "PM: Invalid LZO compressed length\n");
1220 ret = -1;
1221 goto out_finish;
1222 }
1223
1224 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1225 PAGE_SIZE);
1226 if (need > have) {
1227 if (eof > 1) {
1228 ret = -1;
1229 goto out_finish;
1230 }
1231 break;
1232 }
1233
1234 for (off = 0;
1235 off < LZO_HEADER + data[thr].cmp_len;
1236 off += PAGE_SIZE) {
1237 memcpy(data[thr].cmp + off,
1238 page[pg], PAGE_SIZE);
1239 have--;
1240 want++;
1241 if (++pg >= ring_size)
1242 pg = 0;
1243 }
1244
1245 atomic_set(&data[thr].ready, 1);
1246 wake_up(&data[thr].go);
1247 }
1248
1249 /*
1250 * Wait for more data while we are decompressing.
1251 */
1252 if (have < LZO_CMP_PAGES && asked) {
1253 ret = hib_wait_on_bio_chain(&bio);
1254 if (ret)
1255 goto out_finish;
1256 have += asked;
1257 asked = 0;
1258 if (eof)
1259 eof = 2;
1260 }
1261
1262 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1263 wait_event(data[thr].done,
1264 atomic_read(&data[thr].stop));
1265 atomic_set(&data[thr].stop, 0);
1266
1267 ret = data[thr].ret;
1268
1269 if (ret < 0) {
1270 printk(KERN_ERR
1271 "PM: LZO decompression failed\n");
1272 goto out_finish;
1273 }
1274
1275 if (unlikely(!data[thr].unc_len ||
1276 data[thr].unc_len > LZO_UNC_SIZE ||
1277 data[thr].unc_len & (PAGE_SIZE - 1))) {
1278 printk(KERN_ERR
1279 "PM: Invalid LZO uncompressed length\n");
1280 ret = -1;
1281 goto out_finish;
1282 }
1283
1284 for (off = 0;
1285 off < data[thr].unc_len; off += PAGE_SIZE) {
1286 memcpy(data_of(*snapshot),
1287 data[thr].unc + off, PAGE_SIZE);
1288
1289 if (!(nr_pages % m))
1290 printk("\b\b\b\b%3d%%", nr_pages / m);
1291 nr_pages++;
1292
1293 ret = snapshot_write_next(snapshot);
1294 if (ret <= 0) {
1295 crc->run_threads = thr + 1;
1296 atomic_set(&crc->ready, 1);
1297 wake_up(&crc->go);
1298 goto out_finish;
1299 }
1300 }
1301 }
1302
1303 crc->run_threads = thr;
1304 atomic_set(&crc->ready, 1);
1305 wake_up(&crc->go);
1306 }
1307
1308 out_finish:
1309 if (crc->run_threads) {
1310 wait_event(crc->done, atomic_read(&crc->stop));
1311 atomic_set(&crc->stop, 0);
1312 }
1313 do_gettimeofday(&stop);
1314 if (!ret) {
1315 printk("\b\b\b\bdone\n");
1316 snapshot_write_finalize(snapshot);
1317 if (!snapshot_image_loaded(snapshot))
1318 ret = -ENODATA;
1319 if (!ret) {
1320 if (swsusp_header->flags & SF_CRC32_MODE) {
1321 if(handle->crc32 != swsusp_header->crc32) {
1322 printk(KERN_ERR
1323 "PM: Invalid image CRC32!\n");
1324 ret = -ENODATA;
1325 }
1326 }
1327 }
1328 } else
1329 printk("\n");
1330 swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1331 out_clean:
1332 for (i = 0; i < ring_size; i++)
1333 free_page((unsigned long)page[i]);
1334 if (crc) {
1335 if (crc->thr)
1336 kthread_stop(crc->thr);
1337 kfree(crc);
1338 }
1339 if (data) {
1340 for (thr = 0; thr < nr_threads; thr++)
1341 if (data[thr].thr)
1342 kthread_stop(data[thr].thr);
1343 vfree(data);
1344 }
1345 if (page) vfree(page);
1346
1347 return ret;
1348 }
1349
1350 /**
1351 * swsusp_read - read the hibernation image.
1352 * @flags_p: flags passed by the "frozen" kernel in the image header should
1353 * be written into this memory location
1354 */
1355
1356 int swsusp_read(unsigned int *flags_p)
1357 {
1358 int error;
1359 struct swap_map_handle handle;
1360 struct snapshot_handle snapshot;
1361 struct swsusp_info *header;
1362
1363 memset(&snapshot, 0, sizeof(struct snapshot_handle));
1364 error = snapshot_write_next(&snapshot);
1365 if (error < PAGE_SIZE)
1366 return error < 0 ? error : -EFAULT;
1367 header = (struct swsusp_info *)data_of(snapshot);
1368 error = get_swap_reader(&handle, flags_p);
1369 if (error)
1370 goto end;
1371 if (!error)
1372 error = swap_read_page(&handle, header, NULL);
1373 if (!error) {
1374 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1375 load_image(&handle, &snapshot, header->pages - 1) :
1376 load_image_lzo(&handle, &snapshot, header->pages - 1);
1377 }
1378 swap_reader_finish(&handle);
1379 end:
1380 if (!error)
1381 pr_debug("PM: Image successfully loaded\n");
1382 else
1383 pr_debug("PM: Error %d resuming\n", error);
1384 return error;
1385 }
1386
1387 /**
1388 * swsusp_check - Check for swsusp signature in the resume device
1389 */
1390
1391 int swsusp_check(void)
1392 {
1393 int error;
1394
1395 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1396 FMODE_READ, NULL);
1397 if (!IS_ERR(hib_resume_bdev)) {
1398 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1399 clear_page(swsusp_header);
1400 error = hib_bio_read_page(swsusp_resume_block,
1401 swsusp_header, NULL);
1402 if (error)
1403 goto put;
1404
1405 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1406 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1407 /* Reset swap signature now */
1408 error = hib_bio_write_page(swsusp_resume_block,
1409 swsusp_header, NULL);
1410 } else {
1411 error = -EINVAL;
1412 }
1413
1414 put:
1415 if (error)
1416 blkdev_put(hib_resume_bdev, FMODE_READ);
1417 else
1418 pr_debug("PM: Image signature found, resuming\n");
1419 } else {
1420 error = PTR_ERR(hib_resume_bdev);
1421 }
1422
1423 if (error)
1424 pr_debug("PM: Image not found (code %d)\n", error);
1425
1426 return error;
1427 }
1428
1429 /**
1430 * swsusp_close - close swap device.
1431 */
1432
1433 void swsusp_close(fmode_t mode)
1434 {
1435 if (IS_ERR(hib_resume_bdev)) {
1436 pr_debug("PM: Image device not initialised\n");
1437 return;
1438 }
1439
1440 blkdev_put(hib_resume_bdev, mode);
1441 }
1442
1443 static int swsusp_header_init(void)
1444 {
1445 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1446 if (!swsusp_header)
1447 panic("Could not allocate memory for swsusp_header\n");
1448 return 0;
1449 }
1450
1451 core_initcall(swsusp_header_init);
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