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 * 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/* 56 * Number of free pages that are not high. 57 */ 58static inline unsigned long low_free_pages(void) 59{ 60 return nr_free_pages() - nr_free_highpages(); 61} 62 63/* 64 * Number of pages required to be kept free while writing the image. Always 65 * half of all available low pages before the writing starts. 66 */ 67static inline unsigned long reqd_free_pages(void) 68{ 69 return low_free_pages() / 2; 70} 71 72struct swap_map_page { 73 sector_t entries[MAP_PAGE_ENTRIES]; 74 sector_t next_swap; 75}; 76 77struct swap_map_page_list { 78 struct swap_map_page *map; 79 struct swap_map_page_list *next; 80}; 81 82/** 83 * The swap_map_handle structure is used for handling swap in 84 * a file-alike way 85 */ 86 87struct swap_map_handle { 88 struct swap_map_page *cur; 89 struct swap_map_page_list *maps; 90 sector_t cur_swap; 91 sector_t first_sector; 92 unsigned int k; 93 unsigned long reqd_free_pages; 94 u32 crc32; 95}; 96 97struct swsusp_header { 98 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) - 99 sizeof(u32)]; 100 u32 crc32; 101 sector_t image; 102 unsigned int flags; /* Flags to pass to the "boot" kernel */ 103 char orig_sig[10]; 104 char sig[10]; 105} __packed; 106 107static struct swsusp_header *swsusp_header; 108 109/** 110 * The following functions are used for tracing the allocated 111 * swap pages, so that they can be freed in case of an error. 112 */ 113 114struct swsusp_extent { 115 struct rb_node node; 116 unsigned long start; 117 unsigned long end; 118}; 119 120static struct rb_root swsusp_extents = RB_ROOT; 121 122static int swsusp_extents_insert(unsigned long swap_offset) 123{ 124 struct rb_node **new = &(swsusp_extents.rb_node); 125 struct rb_node *parent = NULL; 126 struct swsusp_extent *ext; 127 128 /* Figure out where to put the new node */ 129 while (*new) { 130 ext = rb_entry(*new, struct swsusp_extent, node); 131 parent = *new; 132 if (swap_offset < ext->start) { 133 /* Try to merge */ 134 if (swap_offset == ext->start - 1) { 135 ext->start--; 136 return 0; 137 } 138 new = &((*new)->rb_left); 139 } else if (swap_offset > ext->end) { 140 /* Try to merge */ 141 if (swap_offset == ext->end + 1) { 142 ext->end++; 143 return 0; 144 } 145 new = &((*new)->rb_right); 146 } else { 147 /* It already is in the tree */ 148 return -EINVAL; 149 } 150 } 151 /* Add the new node and rebalance the tree. */ 152 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); 153 if (!ext) 154 return -ENOMEM; 155 156 ext->start = swap_offset; 157 ext->end = swap_offset; 158 rb_link_node(&ext->node, parent, new); 159 rb_insert_color(&ext->node, &swsusp_extents); 160 return 0; 161} 162 163/** 164 * alloc_swapdev_block - allocate a swap page and register that it has 165 * been allocated, so that it can be freed in case of an error. 166 */ 167 168sector_t alloc_swapdev_block(int swap) 169{ 170 unsigned long offset; 171 172 offset = swp_offset(get_swap_page_of_type(swap)); 173 if (offset) { 174 if (swsusp_extents_insert(offset)) 175 swap_free(swp_entry(swap, offset)); 176 else 177 return swapdev_block(swap, offset); 178 } 179 return 0; 180} 181 182/** 183 * free_all_swap_pages - free swap pages allocated for saving image data. 184 * It also frees the extents used to register which swap entries had been 185 * allocated. 186 */ 187 188void free_all_swap_pages(int swap) 189{ 190 struct rb_node *node; 191 192 while ((node = swsusp_extents.rb_node)) { 193 struct swsusp_extent *ext; 194 unsigned long offset; 195 196 ext = container_of(node, struct swsusp_extent, node); 197 rb_erase(node, &swsusp_extents); 198 for (offset = ext->start; offset <= ext->end; offset++) 199 swap_free(swp_entry(swap, offset)); 200 201 kfree(ext); 202 } 203} 204 205int swsusp_swap_in_use(void) 206{ 207 return (swsusp_extents.rb_node != NULL); 208} 209 210/* 211 * General things 212 */ 213 214static unsigned short root_swap = 0xffff; 215struct block_device *hib_resume_bdev; 216 217/* 218 * Saving part 219 */ 220 221static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) 222{ 223 int error; 224 225 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); 226 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || 227 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { 228 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); 229 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10); 230 swsusp_header->image = handle->first_sector; 231 swsusp_header->flags = flags; 232 if (flags & SF_CRC32_MODE) 233 swsusp_header->crc32 = handle->crc32; 234 error = hib_bio_write_page(swsusp_resume_block, 235 swsusp_header, NULL); 236 } else { 237 printk(KERN_ERR "PM: Swap header not found!\n"); 238 error = -ENODEV; 239 } 240 return error; 241} 242 243/** 244 * swsusp_swap_check - check if the resume device is a swap device 245 * and get its index (if so) 246 * 247 * This is called before saving image 248 */ 249static int swsusp_swap_check(void) 250{ 251 int res; 252 253 res = swap_type_of(swsusp_resume_device, swsusp_resume_block, 254 &hib_resume_bdev); 255 if (res < 0) 256 return res; 257 258 root_swap = res; 259 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL); 260 if (res) 261 return res; 262 263 res = set_blocksize(hib_resume_bdev, PAGE_SIZE); 264 if (res < 0) 265 blkdev_put(hib_resume_bdev, FMODE_WRITE); 266 267 return res; 268} 269 270/** 271 * write_page - Write one page to given swap location. 272 * @buf: Address we're writing. 273 * @offset: Offset of the swap page we're writing to. 274 * @bio_chain: Link the next write BIO here 275 */ 276 277static int write_page(void *buf, sector_t offset, struct bio **bio_chain) 278{ 279 void *src; 280 int ret; 281 282 if (!offset) 283 return -ENOSPC; 284 285 if (bio_chain) { 286 src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN | 287 __GFP_NORETRY); 288 if (src) { 289 copy_page(src, buf); 290 } else { 291 ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */ 292 if (ret) 293 return ret; 294 src = (void *)__get_free_page(__GFP_WAIT | 295 __GFP_NOWARN | 296 __GFP_NORETRY); 297 if (src) { 298 copy_page(src, buf); 299 } else { 300 WARN_ON_ONCE(1); 301 bio_chain = NULL; /* Go synchronous */ 302 src = buf; 303 } 304 } 305 } else { 306 src = buf; 307 } 308 return hib_bio_write_page(offset, src, bio_chain); 309} 310 311static void release_swap_writer(struct swap_map_handle *handle) 312{ 313 if (handle->cur) 314 free_page((unsigned long)handle->cur); 315 handle->cur = NULL; 316} 317 318static int get_swap_writer(struct swap_map_handle *handle) 319{ 320 int ret; 321 322 ret = swsusp_swap_check(); 323 if (ret) { 324 if (ret != -ENOSPC) 325 printk(KERN_ERR "PM: Cannot find swap device, try " 326 "swapon -a.\n"); 327 return ret; 328 } 329 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); 330 if (!handle->cur) { 331 ret = -ENOMEM; 332 goto err_close; 333 } 334 handle->cur_swap = alloc_swapdev_block(root_swap); 335 if (!handle->cur_swap) { 336 ret = -ENOSPC; 337 goto err_rel; 338 } 339 handle->k = 0; 340 handle->reqd_free_pages = reqd_free_pages(); 341 handle->first_sector = handle->cur_swap; 342 return 0; 343err_rel: 344 release_swap_writer(handle); 345err_close: 346 swsusp_close(FMODE_WRITE); 347 return ret; 348} 349 350static int swap_write_page(struct swap_map_handle *handle, void *buf, 351 struct bio **bio_chain) 352{ 353 int error = 0; 354 sector_t offset; 355 356 if (!handle->cur) 357 return -EINVAL; 358 offset = alloc_swapdev_block(root_swap); 359 error = write_page(buf, offset, bio_chain); 360 if (error) 361 return error; 362 handle->cur->entries[handle->k++] = offset; 363 if (handle->k >= MAP_PAGE_ENTRIES) { 364 offset = alloc_swapdev_block(root_swap); 365 if (!offset) 366 return -ENOSPC; 367 handle->cur->next_swap = offset; 368 error = write_page(handle->cur, handle->cur_swap, bio_chain); 369 if (error) 370 goto out; 371 clear_page(handle->cur); 372 handle->cur_swap = offset; 373 handle->k = 0; 374 375 if (bio_chain && low_free_pages() <= handle->reqd_free_pages) { 376 error = hib_wait_on_bio_chain(bio_chain); 377 if (error) 378 goto out; 379 /* 380 * Recalculate the number of required free pages, to 381 * make sure we never take more than half. 382 */ 383 handle->reqd_free_pages = reqd_free_pages(); 384 } 385 } 386 out: 387 return error; 388} 389 390static int flush_swap_writer(struct swap_map_handle *handle) 391{ 392 if (handle->cur && handle->cur_swap) 393 return write_page(handle->cur, handle->cur_swap, NULL); 394 else 395 return -EINVAL; 396} 397 398static int swap_writer_finish(struct swap_map_handle *handle, 399 unsigned int flags, int error) 400{ 401 if (!error) { 402 flush_swap_writer(handle); 403 printk(KERN_INFO "PM: S"); 404 error = mark_swapfiles(handle, flags); 405 printk("|\n"); 406 } 407 408 if (error) 409 free_all_swap_pages(root_swap); 410 release_swap_writer(handle); 411 swsusp_close(FMODE_WRITE); 412 413 return error; 414} 415 416/* We need to remember how much compressed data we need to read. */ 417#define LZO_HEADER sizeof(size_t) 418 419/* Number of pages/bytes we'll compress at one time. */ 420#define LZO_UNC_PAGES 32 421#define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) 422 423/* Number of pages/bytes we need for compressed data (worst case). */ 424#define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ 425 LZO_HEADER, PAGE_SIZE) 426#define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) 427 428/* Maximum number of threads for compression/decompression. */ 429#define LZO_THREADS 3 430 431/* Minimum/maximum number of pages for read buffering. */ 432#define LZO_MIN_RD_PAGES 1024 433#define LZO_MAX_RD_PAGES 8192 434 435 436/** 437 * save_image - save the suspend image data 438 */ 439 440static int save_image(struct swap_map_handle *handle, 441 struct snapshot_handle *snapshot, 442 unsigned int nr_to_write) 443{ 444 unsigned int m; 445 int ret; 446 int nr_pages; 447 int err2; 448 struct bio *bio; 449 ktime_t start; 450 ktime_t stop; 451 452 printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n", 453 nr_to_write); 454 m = nr_to_write / 10; 455 if (!m) 456 m = 1; 457 nr_pages = 0; 458 bio = NULL; 459 start = ktime_get(); 460 while (1) { 461 ret = snapshot_read_next(snapshot); 462 if (ret <= 0) 463 break; 464 ret = swap_write_page(handle, data_of(*snapshot), &bio); 465 if (ret) 466 break; 467 if (!(nr_pages % m)) 468 printk(KERN_INFO "PM: Image saving progress: %3d%%\n", 469 nr_pages / m * 10); 470 nr_pages++; 471 } 472 err2 = hib_wait_on_bio_chain(&bio); 473 stop = ktime_get(); 474 if (!ret) 475 ret = err2; 476 if (!ret) 477 printk(KERN_INFO "PM: Image saving done.\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 map 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 ktime_t start; 585 ktime_t 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)...\n", 672 nr_threads, nr_to_write); 673 m = nr_to_write / 10; 674 if (!m) 675 m = 1; 676 nr_pages = 0; 677 bio = NULL; 678 start = ktime_get(); 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_INFO 694 "PM: Image saving progress: " 695 "%3d%%\n", 696 nr_pages / m * 10); 697 nr_pages++; 698 } 699 if (!off) 700 break; 701 702 data[thr].unc_len = off; 703 704 atomic_set(&data[thr].ready, 1); 705 wake_up(&data[thr].go); 706 } 707 708 if (!thr) 709 break; 710 711 crc->run_threads = thr; 712 atomic_set(&crc->ready, 1); 713 wake_up(&crc->go); 714 715 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 716 wait_event(data[thr].done, 717 atomic_read(&data[thr].stop)); 718 atomic_set(&data[thr].stop, 0); 719 720 ret = data[thr].ret; 721 722 if (ret < 0) { 723 printk(KERN_ERR "PM: LZO compression failed\n"); 724 goto out_finish; 725 } 726 727 if (unlikely(!data[thr].cmp_len || 728 data[thr].cmp_len > 729 lzo1x_worst_compress(data[thr].unc_len))) { 730 printk(KERN_ERR 731 "PM: Invalid LZO compressed length\n"); 732 ret = -1; 733 goto out_finish; 734 } 735 736 *(size_t *)data[thr].cmp = data[thr].cmp_len; 737 738 /* 739 * Given we are writing one page at a time to disk, we 740 * copy that much from the buffer, although the last 741 * bit will likely be smaller than full page. This is 742 * OK - we saved the length of the compressed data, so 743 * any garbage at the end will be discarded when we 744 * read it. 745 */ 746 for (off = 0; 747 off < LZO_HEADER + data[thr].cmp_len; 748 off += PAGE_SIZE) { 749 memcpy(page, data[thr].cmp + off, PAGE_SIZE); 750 751 ret = swap_write_page(handle, page, &bio); 752 if (ret) 753 goto out_finish; 754 } 755 } 756 757 wait_event(crc->done, atomic_read(&crc->stop)); 758 atomic_set(&crc->stop, 0); 759 } 760 761out_finish: 762 err2 = hib_wait_on_bio_chain(&bio); 763 stop = ktime_get(); 764 if (!ret) 765 ret = err2; 766 if (!ret) 767 printk(KERN_INFO "PM: Image saving done.\n"); 768 swsusp_show_speed(start, stop, nr_to_write, "Wrote"); 769out_clean: 770 if (crc) { 771 if (crc->thr) 772 kthread_stop(crc->thr); 773 kfree(crc); 774 } 775 if (data) { 776 for (thr = 0; thr < nr_threads; thr++) 777 if (data[thr].thr) 778 kthread_stop(data[thr].thr); 779 vfree(data); 780 } 781 if (page) free_page((unsigned long)page); 782 783 return ret; 784} 785 786/** 787 * enough_swap - Make sure we have enough swap to save the image. 788 * 789 * Returns TRUE or FALSE after checking the total amount of swap 790 * space avaiable from the resume partition. 791 */ 792 793static int enough_swap(unsigned int nr_pages, unsigned int flags) 794{ 795 unsigned int free_swap = count_swap_pages(root_swap, 1); 796 unsigned int required; 797 798 pr_debug("PM: Free swap pages: %u\n", free_swap); 799 800 required = PAGES_FOR_IO + nr_pages; 801 return free_swap > required; 802} 803 804/** 805 * swsusp_write - Write entire image and metadata. 806 * @flags: flags to pass to the "boot" kernel in the image header 807 * 808 * It is important _NOT_ to umount filesystems at this point. We want 809 * them synced (in case something goes wrong) but we DO not want to mark 810 * filesystem clean: it is not. (And it does not matter, if we resume 811 * correctly, we'll mark system clean, anyway.) 812 */ 813 814int swsusp_write(unsigned int flags) 815{ 816 struct swap_map_handle handle; 817 struct snapshot_handle snapshot; 818 struct swsusp_info *header; 819 unsigned long pages; 820 int error; 821 822 pages = snapshot_get_image_size(); 823 error = get_swap_writer(&handle); 824 if (error) { 825 printk(KERN_ERR "PM: Cannot get swap writer\n"); 826 return error; 827 } 828 if (flags & SF_NOCOMPRESS_MODE) { 829 if (!enough_swap(pages, flags)) { 830 printk(KERN_ERR "PM: Not enough free swap\n"); 831 error = -ENOSPC; 832 goto out_finish; 833 } 834 } 835 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 836 error = snapshot_read_next(&snapshot); 837 if (error < PAGE_SIZE) { 838 if (error >= 0) 839 error = -EFAULT; 840 841 goto out_finish; 842 } 843 header = (struct swsusp_info *)data_of(snapshot); 844 error = swap_write_page(&handle, header, NULL); 845 if (!error) { 846 error = (flags & SF_NOCOMPRESS_MODE) ? 847 save_image(&handle, &snapshot, pages - 1) : 848 save_image_lzo(&handle, &snapshot, pages - 1); 849 } 850out_finish: 851 error = swap_writer_finish(&handle, flags, error); 852 return error; 853} 854 855/** 856 * The following functions allow us to read data using a swap map 857 * in a file-alike way 858 */ 859 860static void release_swap_reader(struct swap_map_handle *handle) 861{ 862 struct swap_map_page_list *tmp; 863 864 while (handle->maps) { 865 if (handle->maps->map) 866 free_page((unsigned long)handle->maps->map); 867 tmp = handle->maps; 868 handle->maps = handle->maps->next; 869 kfree(tmp); 870 } 871 handle->cur = NULL; 872} 873 874static int get_swap_reader(struct swap_map_handle *handle, 875 unsigned int *flags_p) 876{ 877 int error; 878 struct swap_map_page_list *tmp, *last; 879 sector_t offset; 880 881 *flags_p = swsusp_header->flags; 882 883 if (!swsusp_header->image) /* how can this happen? */ 884 return -EINVAL; 885 886 handle->cur = NULL; 887 last = handle->maps = NULL; 888 offset = swsusp_header->image; 889 while (offset) { 890 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL); 891 if (!tmp) { 892 release_swap_reader(handle); 893 return -ENOMEM; 894 } 895 memset(tmp, 0, sizeof(*tmp)); 896 if (!handle->maps) 897 handle->maps = tmp; 898 if (last) 899 last->next = tmp; 900 last = tmp; 901 902 tmp->map = (struct swap_map_page *) 903 __get_free_page(__GFP_WAIT | __GFP_HIGH); 904 if (!tmp->map) { 905 release_swap_reader(handle); 906 return -ENOMEM; 907 } 908 909 error = hib_bio_read_page(offset, tmp->map, NULL); 910 if (error) { 911 release_swap_reader(handle); 912 return error; 913 } 914 offset = tmp->map->next_swap; 915 } 916 handle->k = 0; 917 handle->cur = handle->maps->map; 918 return 0; 919} 920 921static int swap_read_page(struct swap_map_handle *handle, void *buf, 922 struct bio **bio_chain) 923{ 924 sector_t offset; 925 int error; 926 struct swap_map_page_list *tmp; 927 928 if (!handle->cur) 929 return -EINVAL; 930 offset = handle->cur->entries[handle->k]; 931 if (!offset) 932 return -EFAULT; 933 error = hib_bio_read_page(offset, buf, bio_chain); 934 if (error) 935 return error; 936 if (++handle->k >= MAP_PAGE_ENTRIES) { 937 handle->k = 0; 938 free_page((unsigned long)handle->maps->map); 939 tmp = handle->maps; 940 handle->maps = handle->maps->next; 941 kfree(tmp); 942 if (!handle->maps) 943 release_swap_reader(handle); 944 else 945 handle->cur = handle->maps->map; 946 } 947 return error; 948} 949 950static int swap_reader_finish(struct swap_map_handle *handle) 951{ 952 release_swap_reader(handle); 953 954 return 0; 955} 956 957/** 958 * load_image - load the image using the swap map handle 959 * @handle and the snapshot handle @snapshot 960 * (assume there are @nr_pages pages to load) 961 */ 962 963static int load_image(struct swap_map_handle *handle, 964 struct snapshot_handle *snapshot, 965 unsigned int nr_to_read) 966{ 967 unsigned int m; 968 int ret = 0; 969 ktime_t start; 970 ktime_t stop; 971 struct bio *bio; 972 int err2; 973 unsigned nr_pages; 974 975 printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n", 976 nr_to_read); 977 m = nr_to_read / 10; 978 if (!m) 979 m = 1; 980 nr_pages = 0; 981 bio = NULL; 982 start = ktime_get(); 983 for ( ; ; ) { 984 ret = snapshot_write_next(snapshot); 985 if (ret <= 0) 986 break; 987 ret = swap_read_page(handle, data_of(*snapshot), &bio); 988 if (ret) 989 break; 990 if (snapshot->sync_read) 991 ret = hib_wait_on_bio_chain(&bio); 992 if (ret) 993 break; 994 if (!(nr_pages % m)) 995 printk(KERN_INFO "PM: Image loading progress: %3d%%\n", 996 nr_pages / m * 10); 997 nr_pages++; 998 } 999 err2 = hib_wait_on_bio_chain(&bio); 1000 stop = ktime_get(); 1001 if (!ret) 1002 ret = err2; 1003 if (!ret) { 1004 printk(KERN_INFO "PM: Image loading done.\n"); 1005 snapshot_write_finalize(snapshot); 1006 if (!snapshot_image_loaded(snapshot)) 1007 ret = -ENODATA; 1008 } 1009 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1010 return ret; 1011} 1012 1013/** 1014 * Structure used for LZO data decompression. 1015 */ 1016struct dec_data { 1017 struct task_struct *thr; /* thread */ 1018 atomic_t ready; /* ready to start flag */ 1019 atomic_t stop; /* ready to stop flag */ 1020 int ret; /* return code */ 1021 wait_queue_head_t go; /* start decompression */ 1022 wait_queue_head_t done; /* decompression done */ 1023 size_t unc_len; /* uncompressed length */ 1024 size_t cmp_len; /* compressed length */ 1025 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 1026 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 1027}; 1028 1029/** 1030 * Deompression function that runs in its own thread. 1031 */ 1032static int lzo_decompress_threadfn(void *data) 1033{ 1034 struct dec_data *d = data; 1035 1036 while (1) { 1037 wait_event(d->go, atomic_read(&d->ready) || 1038 kthread_should_stop()); 1039 if (kthread_should_stop()) { 1040 d->thr = NULL; 1041 d->ret = -1; 1042 atomic_set(&d->stop, 1); 1043 wake_up(&d->done); 1044 break; 1045 } 1046 atomic_set(&d->ready, 0); 1047 1048 d->unc_len = LZO_UNC_SIZE; 1049 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, 1050 d->unc, &d->unc_len); 1051 atomic_set(&d->stop, 1); 1052 wake_up(&d->done); 1053 } 1054 return 0; 1055} 1056 1057/** 1058 * load_image_lzo - Load compressed image data and decompress them with LZO. 1059 * @handle: Swap map handle to use for loading data. 1060 * @snapshot: Image to copy uncompressed data into. 1061 * @nr_to_read: Number of pages to load. 1062 */ 1063static int load_image_lzo(struct swap_map_handle *handle, 1064 struct snapshot_handle *snapshot, 1065 unsigned int nr_to_read) 1066{ 1067 unsigned int m; 1068 int ret = 0; 1069 int eof = 0; 1070 struct bio *bio; 1071 ktime_t start; 1072 ktime_t stop; 1073 unsigned nr_pages; 1074 size_t off; 1075 unsigned i, thr, run_threads, nr_threads; 1076 unsigned ring = 0, pg = 0, ring_size = 0, 1077 have = 0, want, need, asked = 0; 1078 unsigned long read_pages = 0; 1079 unsigned char **page = NULL; 1080 struct dec_data *data = NULL; 1081 struct crc_data *crc = NULL; 1082 1083 /* 1084 * We'll limit the number of threads for decompression to limit memory 1085 * footprint. 1086 */ 1087 nr_threads = num_online_cpus() - 1; 1088 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 1089 1090 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES); 1091 if (!page) { 1092 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 1093 ret = -ENOMEM; 1094 goto out_clean; 1095 } 1096 1097 data = vmalloc(sizeof(*data) * nr_threads); 1098 if (!data) { 1099 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 1100 ret = -ENOMEM; 1101 goto out_clean; 1102 } 1103 for (thr = 0; thr < nr_threads; thr++) 1104 memset(&data[thr], 0, offsetof(struct dec_data, go)); 1105 1106 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 1107 if (!crc) { 1108 printk(KERN_ERR "PM: Failed to allocate crc\n"); 1109 ret = -ENOMEM; 1110 goto out_clean; 1111 } 1112 memset(crc, 0, offsetof(struct crc_data, go)); 1113 1114 /* 1115 * Start the decompression threads. 1116 */ 1117 for (thr = 0; thr < nr_threads; thr++) { 1118 init_waitqueue_head(&data[thr].go); 1119 init_waitqueue_head(&data[thr].done); 1120 1121 data[thr].thr = kthread_run(lzo_decompress_threadfn, 1122 &data[thr], 1123 "image_decompress/%u", thr); 1124 if (IS_ERR(data[thr].thr)) { 1125 data[thr].thr = NULL; 1126 printk(KERN_ERR 1127 "PM: Cannot start decompression threads\n"); 1128 ret = -ENOMEM; 1129 goto out_clean; 1130 } 1131 } 1132 1133 /* 1134 * Start the CRC32 thread. 1135 */ 1136 init_waitqueue_head(&crc->go); 1137 init_waitqueue_head(&crc->done); 1138 1139 handle->crc32 = 0; 1140 crc->crc32 = &handle->crc32; 1141 for (thr = 0; thr < nr_threads; thr++) { 1142 crc->unc[thr] = data[thr].unc; 1143 crc->unc_len[thr] = &data[thr].unc_len; 1144 } 1145 1146 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 1147 if (IS_ERR(crc->thr)) { 1148 crc->thr = NULL; 1149 printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); 1150 ret = -ENOMEM; 1151 goto out_clean; 1152 } 1153 1154 /* 1155 * Set the number of pages for read buffering. 1156 * This is complete guesswork, because we'll only know the real 1157 * picture once prepare_image() is called, which is much later on 1158 * during the image load phase. We'll assume the worst case and 1159 * say that none of the image pages are from high memory. 1160 */ 1161 if (low_free_pages() > snapshot_get_image_size()) 1162 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2; 1163 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES); 1164 1165 for (i = 0; i < read_pages; i++) { 1166 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ? 1167 __GFP_WAIT | __GFP_HIGH : 1168 __GFP_WAIT | __GFP_NOWARN | 1169 __GFP_NORETRY); 1170 1171 if (!page[i]) { 1172 if (i < LZO_CMP_PAGES) { 1173 ring_size = i; 1174 printk(KERN_ERR 1175 "PM: Failed to allocate LZO pages\n"); 1176 ret = -ENOMEM; 1177 goto out_clean; 1178 } else { 1179 break; 1180 } 1181 } 1182 } 1183 want = ring_size = i; 1184 1185 printk(KERN_INFO 1186 "PM: Using %u thread(s) for decompression.\n" 1187 "PM: Loading and decompressing image data (%u pages)...\n", 1188 nr_threads, nr_to_read); 1189 m = nr_to_read / 10; 1190 if (!m) 1191 m = 1; 1192 nr_pages = 0; 1193 bio = NULL; 1194 start = ktime_get(); 1195 1196 ret = snapshot_write_next(snapshot); 1197 if (ret <= 0) 1198 goto out_finish; 1199 1200 for(;;) { 1201 for (i = 0; !eof && i < want; i++) { 1202 ret = swap_read_page(handle, page[ring], &bio); 1203 if (ret) { 1204 /* 1205 * On real read error, finish. On end of data, 1206 * set EOF flag and just exit the read loop. 1207 */ 1208 if (handle->cur && 1209 handle->cur->entries[handle->k]) { 1210 goto out_finish; 1211 } else { 1212 eof = 1; 1213 break; 1214 } 1215 } 1216 if (++ring >= ring_size) 1217 ring = 0; 1218 } 1219 asked += i; 1220 want -= i; 1221 1222 /* 1223 * We are out of data, wait for some more. 1224 */ 1225 if (!have) { 1226 if (!asked) 1227 break; 1228 1229 ret = hib_wait_on_bio_chain(&bio); 1230 if (ret) 1231 goto out_finish; 1232 have += asked; 1233 asked = 0; 1234 if (eof) 1235 eof = 2; 1236 } 1237 1238 if (crc->run_threads) { 1239 wait_event(crc->done, atomic_read(&crc->stop)); 1240 atomic_set(&crc->stop, 0); 1241 crc->run_threads = 0; 1242 } 1243 1244 for (thr = 0; have && thr < nr_threads; thr++) { 1245 data[thr].cmp_len = *(size_t *)page[pg]; 1246 if (unlikely(!data[thr].cmp_len || 1247 data[thr].cmp_len > 1248 lzo1x_worst_compress(LZO_UNC_SIZE))) { 1249 printk(KERN_ERR 1250 "PM: Invalid LZO compressed length\n"); 1251 ret = -1; 1252 goto out_finish; 1253 } 1254 1255 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, 1256 PAGE_SIZE); 1257 if (need > have) { 1258 if (eof > 1) { 1259 ret = -1; 1260 goto out_finish; 1261 } 1262 break; 1263 } 1264 1265 for (off = 0; 1266 off < LZO_HEADER + data[thr].cmp_len; 1267 off += PAGE_SIZE) { 1268 memcpy(data[thr].cmp + off, 1269 page[pg], PAGE_SIZE); 1270 have--; 1271 want++; 1272 if (++pg >= ring_size) 1273 pg = 0; 1274 } 1275 1276 atomic_set(&data[thr].ready, 1); 1277 wake_up(&data[thr].go); 1278 } 1279 1280 /* 1281 * Wait for more data while we are decompressing. 1282 */ 1283 if (have < LZO_CMP_PAGES && asked) { 1284 ret = hib_wait_on_bio_chain(&bio); 1285 if (ret) 1286 goto out_finish; 1287 have += asked; 1288 asked = 0; 1289 if (eof) 1290 eof = 2; 1291 } 1292 1293 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 1294 wait_event(data[thr].done, 1295 atomic_read(&data[thr].stop)); 1296 atomic_set(&data[thr].stop, 0); 1297 1298 ret = data[thr].ret; 1299 1300 if (ret < 0) { 1301 printk(KERN_ERR 1302 "PM: LZO decompression failed\n"); 1303 goto out_finish; 1304 } 1305 1306 if (unlikely(!data[thr].unc_len || 1307 data[thr].unc_len > LZO_UNC_SIZE || 1308 data[thr].unc_len & (PAGE_SIZE - 1))) { 1309 printk(KERN_ERR 1310 "PM: Invalid LZO uncompressed length\n"); 1311 ret = -1; 1312 goto out_finish; 1313 } 1314 1315 for (off = 0; 1316 off < data[thr].unc_len; off += PAGE_SIZE) { 1317 memcpy(data_of(*snapshot), 1318 data[thr].unc + off, PAGE_SIZE); 1319 1320 if (!(nr_pages % m)) 1321 printk(KERN_INFO 1322 "PM: Image loading progress: " 1323 "%3d%%\n", 1324 nr_pages / m * 10); 1325 nr_pages++; 1326 1327 ret = snapshot_write_next(snapshot); 1328 if (ret <= 0) { 1329 crc->run_threads = thr + 1; 1330 atomic_set(&crc->ready, 1); 1331 wake_up(&crc->go); 1332 goto out_finish; 1333 } 1334 } 1335 } 1336 1337 crc->run_threads = thr; 1338 atomic_set(&crc->ready, 1); 1339 wake_up(&crc->go); 1340 } 1341 1342out_finish: 1343 if (crc->run_threads) { 1344 wait_event(crc->done, atomic_read(&crc->stop)); 1345 atomic_set(&crc->stop, 0); 1346 } 1347 stop = ktime_get(); 1348 if (!ret) { 1349 printk(KERN_INFO "PM: Image loading done.\n"); 1350 snapshot_write_finalize(snapshot); 1351 if (!snapshot_image_loaded(snapshot)) 1352 ret = -ENODATA; 1353 if (!ret) { 1354 if (swsusp_header->flags & SF_CRC32_MODE) { 1355 if(handle->crc32 != swsusp_header->crc32) { 1356 printk(KERN_ERR 1357 "PM: Invalid image CRC32!\n"); 1358 ret = -ENODATA; 1359 } 1360 } 1361 } 1362 } 1363 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1364out_clean: 1365 for (i = 0; i < ring_size; i++) 1366 free_page((unsigned long)page[i]); 1367 if (crc) { 1368 if (crc->thr) 1369 kthread_stop(crc->thr); 1370 kfree(crc); 1371 } 1372 if (data) { 1373 for (thr = 0; thr < nr_threads; thr++) 1374 if (data[thr].thr) 1375 kthread_stop(data[thr].thr); 1376 vfree(data); 1377 } 1378 vfree(page); 1379 1380 return ret; 1381} 1382 1383/** 1384 * swsusp_read - read the hibernation image. 1385 * @flags_p: flags passed by the "frozen" kernel in the image header should 1386 * be written into this memory location 1387 */ 1388 1389int swsusp_read(unsigned int *flags_p) 1390{ 1391 int error; 1392 struct swap_map_handle handle; 1393 struct snapshot_handle snapshot; 1394 struct swsusp_info *header; 1395 1396 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 1397 error = snapshot_write_next(&snapshot); 1398 if (error < PAGE_SIZE) 1399 return error < 0 ? error : -EFAULT; 1400 header = (struct swsusp_info *)data_of(snapshot); 1401 error = get_swap_reader(&handle, flags_p); 1402 if (error) 1403 goto end; 1404 if (!error) 1405 error = swap_read_page(&handle, header, NULL); 1406 if (!error) { 1407 error = (*flags_p & SF_NOCOMPRESS_MODE) ? 1408 load_image(&handle, &snapshot, header->pages - 1) : 1409 load_image_lzo(&handle, &snapshot, header->pages - 1); 1410 } 1411 swap_reader_finish(&handle); 1412end: 1413 if (!error) 1414 pr_debug("PM: Image successfully loaded\n"); 1415 else 1416 pr_debug("PM: Error %d resuming\n", error); 1417 return error; 1418} 1419 1420/** 1421 * swsusp_check - Check for swsusp signature in the resume device 1422 */ 1423 1424int swsusp_check(void) 1425{ 1426 int error; 1427 1428 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, 1429 FMODE_READ, NULL); 1430 if (!IS_ERR(hib_resume_bdev)) { 1431 set_blocksize(hib_resume_bdev, PAGE_SIZE); 1432 clear_page(swsusp_header); 1433 error = hib_bio_read_page(swsusp_resume_block, 1434 swsusp_header, NULL); 1435 if (error) 1436 goto put; 1437 1438 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { 1439 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); 1440 /* Reset swap signature now */ 1441 error = hib_bio_write_page(swsusp_resume_block, 1442 swsusp_header, NULL); 1443 } else { 1444 error = -EINVAL; 1445 } 1446 1447put: 1448 if (error) 1449 blkdev_put(hib_resume_bdev, FMODE_READ); 1450 else 1451 pr_debug("PM: Image signature found, resuming\n"); 1452 } else { 1453 error = PTR_ERR(hib_resume_bdev); 1454 } 1455 1456 if (error) 1457 pr_debug("PM: Image not found (code %d)\n", error); 1458 1459 return error; 1460} 1461 1462/** 1463 * swsusp_close - close swap device. 1464 */ 1465 1466void swsusp_close(fmode_t mode) 1467{ 1468 if (IS_ERR(hib_resume_bdev)) { 1469 pr_debug("PM: Image device not initialised\n"); 1470 return; 1471 } 1472 1473 blkdev_put(hib_resume_bdev, mode); 1474} 1475 1476/** 1477 * swsusp_unmark - Unmark swsusp signature in the resume device 1478 */ 1479 1480#ifdef CONFIG_SUSPEND 1481int swsusp_unmark(void) 1482{ 1483 int error; 1484 1485 hib_bio_read_page(swsusp_resume_block, swsusp_header, NULL); 1486 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) { 1487 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10); 1488 error = hib_bio_write_page(swsusp_resume_block, 1489 swsusp_header, NULL); 1490 } else { 1491 printk(KERN_ERR "PM: Cannot find swsusp signature!\n"); 1492 error = -ENODEV; 1493 } 1494 1495 /* 1496 * We just returned from suspend, we don't need the image any more. 1497 */ 1498 free_all_swap_pages(root_swap); 1499 1500 return error; 1501} 1502#endif 1503 1504static int swsusp_header_init(void) 1505{ 1506 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); 1507 if (!swsusp_header) 1508 panic("Could not allocate memory for swsusp_header\n"); 1509 return 0; 1510} 1511 1512core_initcall(swsusp_header_init); 1513