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