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/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 = container_of(*new, struct swsusp_extent, node); 130 parent = *new; 131 if (swap_offset < ext->start) { 132 /* Try to merge */ 133 if (swap_offset == ext->start - 1) { 134 ext->start--; 135 return 0; 136 } 137 new = &((*new)->rb_left); 138 } else if (swap_offset > ext->end) { 139 /* Try to merge */ 140 if (swap_offset == ext->end + 1) { 141 ext->end++; 142 return 0; 143 } 144 new = &((*new)->rb_right); 145 } else { 146 /* It already is in the tree */ 147 return -EINVAL; 148 } 149 } 150 /* Add the new node and rebalance the tree. */ 151 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); 152 if (!ext) 153 return -ENOMEM; 154 155 ext->start = swap_offset; 156 ext->end = swap_offset; 157 rb_link_node(&ext->node, parent, new); 158 rb_insert_color(&ext->node, &swsusp_extents); 159 return 0; 160 } 161 162 /** 163 * alloc_swapdev_block - allocate a swap page and register that it has 164 * been allocated, so that it can be freed in case of an error. 165 */ 166 167 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_HIGH); 286 if (src) { 287 copy_page(src, buf); 288 } else { 289 ret = hib_wait_on_bio_chain(bio_chain); /* Free pages */ 290 if (ret) 291 return ret; 292 src = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); 293 if (src) { 294 copy_page(src, buf); 295 } else { 296 WARN_ON_ONCE(1); 297 bio_chain = NULL; /* Go synchronous */ 298 src = buf; 299 } 300 } 301 } else { 302 src = buf; 303 } 304 return hib_bio_write_page(offset, src, bio_chain); 305 } 306 307 static void release_swap_writer(struct swap_map_handle *handle) 308 { 309 if (handle->cur) 310 free_page((unsigned long)handle->cur); 311 handle->cur = NULL; 312 } 313 314 static int get_swap_writer(struct swap_map_handle *handle) 315 { 316 int ret; 317 318 ret = swsusp_swap_check(); 319 if (ret) { 320 if (ret != -ENOSPC) 321 printk(KERN_ERR "PM: Cannot find swap device, try " 322 "swapon -a.\n"); 323 return ret; 324 } 325 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); 326 if (!handle->cur) { 327 ret = -ENOMEM; 328 goto err_close; 329 } 330 handle->cur_swap = alloc_swapdev_block(root_swap); 331 if (!handle->cur_swap) { 332 ret = -ENOSPC; 333 goto err_rel; 334 } 335 handle->k = 0; 336 handle->reqd_free_pages = reqd_free_pages(); 337 handle->first_sector = handle->cur_swap; 338 return 0; 339 err_rel: 340 release_swap_writer(handle); 341 err_close: 342 swsusp_close(FMODE_WRITE); 343 return ret; 344 } 345 346 static int swap_write_page(struct swap_map_handle *handle, void *buf, 347 struct bio **bio_chain) 348 { 349 int error = 0; 350 sector_t offset; 351 352 if (!handle->cur) 353 return -EINVAL; 354 offset = alloc_swapdev_block(root_swap); 355 error = write_page(buf, offset, bio_chain); 356 if (error) 357 return error; 358 handle->cur->entries[handle->k++] = offset; 359 if (handle->k >= MAP_PAGE_ENTRIES) { 360 offset = alloc_swapdev_block(root_swap); 361 if (!offset) 362 return -ENOSPC; 363 handle->cur->next_swap = offset; 364 error = write_page(handle->cur, handle->cur_swap, bio_chain); 365 if (error) 366 goto out; 367 clear_page(handle->cur); 368 handle->cur_swap = offset; 369 handle->k = 0; 370 } 371 if (bio_chain && low_free_pages() <= handle->reqd_free_pages) { 372 error = hib_wait_on_bio_chain(bio_chain); 373 if (error) 374 goto out; 375 handle->reqd_free_pages = reqd_free_pages(); 376 } 377 out: 378 return error; 379 } 380 381 static int flush_swap_writer(struct swap_map_handle *handle) 382 { 383 if (handle->cur && handle->cur_swap) 384 return write_page(handle->cur, handle->cur_swap, NULL); 385 else 386 return -EINVAL; 387 } 388 389 static int swap_writer_finish(struct swap_map_handle *handle, 390 unsigned int flags, int error) 391 { 392 if (!error) { 393 flush_swap_writer(handle); 394 printk(KERN_INFO "PM: S"); 395 error = mark_swapfiles(handle, flags); 396 printk("|\n"); 397 } 398 399 if (error) 400 free_all_swap_pages(root_swap); 401 release_swap_writer(handle); 402 swsusp_close(FMODE_WRITE); 403 404 return error; 405 } 406 407 /* We need to remember how much compressed data we need to read. */ 408 #define LZO_HEADER sizeof(size_t) 409 410 /* Number of pages/bytes we'll compress at one time. */ 411 #define LZO_UNC_PAGES 32 412 #define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) 413 414 /* Number of pages/bytes we need for compressed data (worst case). */ 415 #define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ 416 LZO_HEADER, PAGE_SIZE) 417 #define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) 418 419 /* Maximum number of threads for compression/decompression. */ 420 #define LZO_THREADS 3 421 422 /* Maximum number of pages for read buffering. */ 423 #define LZO_READ_PAGES (MAP_PAGE_ENTRIES * 8) 424 425 426 /** 427 * save_image - save the suspend image data 428 */ 429 430 static int save_image(struct swap_map_handle *handle, 431 struct snapshot_handle *snapshot, 432 unsigned int nr_to_write) 433 { 434 unsigned int m; 435 int ret; 436 int nr_pages; 437 int err2; 438 struct bio *bio; 439 struct timeval start; 440 struct timeval stop; 441 442 printk(KERN_INFO "PM: Saving image data pages (%u pages) ... ", 443 nr_to_write); 444 m = nr_to_write / 100; 445 if (!m) 446 m = 1; 447 nr_pages = 0; 448 bio = NULL; 449 do_gettimeofday(&start); 450 while (1) { 451 ret = snapshot_read_next(snapshot); 452 if (ret <= 0) 453 break; 454 ret = swap_write_page(handle, data_of(*snapshot), &bio); 455 if (ret) 456 break; 457 if (!(nr_pages % m)) 458 printk(KERN_CONT "\b\b\b\b%3d%%", nr_pages / m); 459 nr_pages++; 460 } 461 err2 = hib_wait_on_bio_chain(&bio); 462 do_gettimeofday(&stop); 463 if (!ret) 464 ret = err2; 465 if (!ret) 466 printk(KERN_CONT "\b\b\b\bdone\n"); 467 else 468 printk(KERN_CONT "\n"); 469 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); 470 return ret; 471 } 472 473 /** 474 * Structure used for CRC32. 475 */ 476 struct crc_data { 477 struct task_struct *thr; /* thread */ 478 atomic_t ready; /* ready to start flag */ 479 atomic_t stop; /* ready to stop flag */ 480 unsigned run_threads; /* nr current threads */ 481 wait_queue_head_t go; /* start crc update */ 482 wait_queue_head_t done; /* crc update done */ 483 u32 *crc32; /* points to handle's crc32 */ 484 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */ 485 unsigned char *unc[LZO_THREADS]; /* uncompressed data */ 486 }; 487 488 /** 489 * CRC32 update function that runs in its own thread. 490 */ 491 static int crc32_threadfn(void *data) 492 { 493 struct crc_data *d = data; 494 unsigned i; 495 496 while (1) { 497 wait_event(d->go, atomic_read(&d->ready) || 498 kthread_should_stop()); 499 if (kthread_should_stop()) { 500 d->thr = NULL; 501 atomic_set(&d->stop, 1); 502 wake_up(&d->done); 503 break; 504 } 505 atomic_set(&d->ready, 0); 506 507 for (i = 0; i < d->run_threads; i++) 508 *d->crc32 = crc32_le(*d->crc32, 509 d->unc[i], *d->unc_len[i]); 510 atomic_set(&d->stop, 1); 511 wake_up(&d->done); 512 } 513 return 0; 514 } 515 /** 516 * Structure used for LZO data compression. 517 */ 518 struct cmp_data { 519 struct task_struct *thr; /* thread */ 520 atomic_t ready; /* ready to start flag */ 521 atomic_t stop; /* ready to stop flag */ 522 int ret; /* return code */ 523 wait_queue_head_t go; /* start compression */ 524 wait_queue_head_t done; /* compression done */ 525 size_t unc_len; /* uncompressed length */ 526 size_t cmp_len; /* compressed length */ 527 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 528 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 529 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */ 530 }; 531 532 /** 533 * Compression function that runs in its own thread. 534 */ 535 static int lzo_compress_threadfn(void *data) 536 { 537 struct cmp_data *d = data; 538 539 while (1) { 540 wait_event(d->go, atomic_read(&d->ready) || 541 kthread_should_stop()); 542 if (kthread_should_stop()) { 543 d->thr = NULL; 544 d->ret = -1; 545 atomic_set(&d->stop, 1); 546 wake_up(&d->done); 547 break; 548 } 549 atomic_set(&d->ready, 0); 550 551 d->ret = lzo1x_1_compress(d->unc, d->unc_len, 552 d->cmp + LZO_HEADER, &d->cmp_len, 553 d->wrk); 554 atomic_set(&d->stop, 1); 555 wake_up(&d->done); 556 } 557 return 0; 558 } 559 560 /** 561 * save_image_lzo - Save the suspend image data compressed with LZO. 562 * @handle: Swap mam handle to use for saving the image. 563 * @snapshot: Image to read data from. 564 * @nr_to_write: Number of pages to save. 565 */ 566 static int save_image_lzo(struct swap_map_handle *handle, 567 struct snapshot_handle *snapshot, 568 unsigned int nr_to_write) 569 { 570 unsigned int m; 571 int ret = 0; 572 int nr_pages; 573 int err2; 574 struct bio *bio; 575 struct timeval start; 576 struct timeval stop; 577 size_t off; 578 unsigned thr, run_threads, nr_threads; 579 unsigned char *page = NULL; 580 struct cmp_data *data = NULL; 581 struct crc_data *crc = NULL; 582 583 /* 584 * We'll limit the number of threads for compression to limit memory 585 * footprint. 586 */ 587 nr_threads = num_online_cpus() - 1; 588 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 589 590 page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH); 591 if (!page) { 592 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 593 ret = -ENOMEM; 594 goto out_clean; 595 } 596 597 data = vmalloc(sizeof(*data) * nr_threads); 598 if (!data) { 599 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 600 ret = -ENOMEM; 601 goto out_clean; 602 } 603 for (thr = 0; thr < nr_threads; thr++) 604 memset(&data[thr], 0, offsetof(struct cmp_data, go)); 605 606 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 607 if (!crc) { 608 printk(KERN_ERR "PM: Failed to allocate crc\n"); 609 ret = -ENOMEM; 610 goto out_clean; 611 } 612 memset(crc, 0, offsetof(struct crc_data, go)); 613 614 /* 615 * Start the compression threads. 616 */ 617 for (thr = 0; thr < nr_threads; thr++) { 618 init_waitqueue_head(&data[thr].go); 619 init_waitqueue_head(&data[thr].done); 620 621 data[thr].thr = kthread_run(lzo_compress_threadfn, 622 &data[thr], 623 "image_compress/%u", thr); 624 if (IS_ERR(data[thr].thr)) { 625 data[thr].thr = NULL; 626 printk(KERN_ERR 627 "PM: Cannot start compression threads\n"); 628 ret = -ENOMEM; 629 goto out_clean; 630 } 631 } 632 633 /* 634 * Adjust number of free pages after all allocations have been done. 635 * We don't want to run out of pages when writing. 636 */ 637 handle->reqd_free_pages = reqd_free_pages(); 638 639 /* 640 * Start the CRC32 thread. 641 */ 642 init_waitqueue_head(&crc->go); 643 init_waitqueue_head(&crc->done); 644 645 handle->crc32 = 0; 646 crc->crc32 = &handle->crc32; 647 for (thr = 0; thr < nr_threads; thr++) { 648 crc->unc[thr] = data[thr].unc; 649 crc->unc_len[thr] = &data[thr].unc_len; 650 } 651 652 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 653 if (IS_ERR(crc->thr)) { 654 crc->thr = NULL; 655 printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); 656 ret = -ENOMEM; 657 goto out_clean; 658 } 659 660 printk(KERN_INFO 661 "PM: Using %u thread(s) for compression.\n" 662 "PM: Compressing and saving image data (%u pages) ... ", 663 nr_threads, nr_to_write); 664 m = nr_to_write / 100; 665 if (!m) 666 m = 1; 667 nr_pages = 0; 668 bio = NULL; 669 do_gettimeofday(&start); 670 for (;;) { 671 for (thr = 0; thr < nr_threads; thr++) { 672 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) { 673 ret = snapshot_read_next(snapshot); 674 if (ret < 0) 675 goto out_finish; 676 677 if (!ret) 678 break; 679 680 memcpy(data[thr].unc + off, 681 data_of(*snapshot), PAGE_SIZE); 682 683 if (!(nr_pages % m)) 684 printk(KERN_CONT "\b\b\b\b%3d%%", 685 nr_pages / m); 686 nr_pages++; 687 } 688 if (!off) 689 break; 690 691 data[thr].unc_len = off; 692 693 atomic_set(&data[thr].ready, 1); 694 wake_up(&data[thr].go); 695 } 696 697 if (!thr) 698 break; 699 700 crc->run_threads = thr; 701 atomic_set(&crc->ready, 1); 702 wake_up(&crc->go); 703 704 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 705 wait_event(data[thr].done, 706 atomic_read(&data[thr].stop)); 707 atomic_set(&data[thr].stop, 0); 708 709 ret = data[thr].ret; 710 711 if (ret < 0) { 712 printk(KERN_ERR "PM: LZO compression failed\n"); 713 goto out_finish; 714 } 715 716 if (unlikely(!data[thr].cmp_len || 717 data[thr].cmp_len > 718 lzo1x_worst_compress(data[thr].unc_len))) { 719 printk(KERN_ERR 720 "PM: Invalid LZO compressed length\n"); 721 ret = -1; 722 goto out_finish; 723 } 724 725 *(size_t *)data[thr].cmp = data[thr].cmp_len; 726 727 /* 728 * Given we are writing one page at a time to disk, we 729 * copy that much from the buffer, although the last 730 * bit will likely be smaller than full page. This is 731 * OK - we saved the length of the compressed data, so 732 * any garbage at the end will be discarded when we 733 * read it. 734 */ 735 for (off = 0; 736 off < LZO_HEADER + data[thr].cmp_len; 737 off += PAGE_SIZE) { 738 memcpy(page, data[thr].cmp + off, PAGE_SIZE); 739 740 ret = swap_write_page(handle, page, &bio); 741 if (ret) 742 goto out_finish; 743 } 744 } 745 746 wait_event(crc->done, atomic_read(&crc->stop)); 747 atomic_set(&crc->stop, 0); 748 } 749 750 out_finish: 751 err2 = hib_wait_on_bio_chain(&bio); 752 do_gettimeofday(&stop); 753 if (!ret) 754 ret = err2; 755 if (!ret) { 756 printk(KERN_CONT "\b\b\b\bdone\n"); 757 } else { 758 printk(KERN_CONT "\n"); 759 } 760 swsusp_show_speed(&start, &stop, nr_to_write, "Wrote"); 761 out_clean: 762 if (crc) { 763 if (crc->thr) 764 kthread_stop(crc->thr); 765 kfree(crc); 766 } 767 if (data) { 768 for (thr = 0; thr < nr_threads; thr++) 769 if (data[thr].thr) 770 kthread_stop(data[thr].thr); 771 vfree(data); 772 } 773 if (page) free_page((unsigned long)page); 774 775 return ret; 776 } 777 778 /** 779 * enough_swap - Make sure we have enough swap to save the image. 780 * 781 * Returns TRUE or FALSE after checking the total amount of swap 782 * space avaiable from the resume partition. 783 */ 784 785 static int enough_swap(unsigned int nr_pages, unsigned int flags) 786 { 787 unsigned int free_swap = count_swap_pages(root_swap, 1); 788 unsigned int required; 789 790 pr_debug("PM: Free swap pages: %u\n", free_swap); 791 792 required = PAGES_FOR_IO + nr_pages; 793 return free_swap > required; 794 } 795 796 /** 797 * swsusp_write - Write entire image and metadata. 798 * @flags: flags to pass to the "boot" kernel in the image header 799 * 800 * It is important _NOT_ to umount filesystems at this point. We want 801 * them synced (in case something goes wrong) but we DO not want to mark 802 * filesystem clean: it is not. (And it does not matter, if we resume 803 * correctly, we'll mark system clean, anyway.) 804 */ 805 806 int swsusp_write(unsigned int flags) 807 { 808 struct swap_map_handle handle; 809 struct snapshot_handle snapshot; 810 struct swsusp_info *header; 811 unsigned long pages; 812 int error; 813 814 pages = snapshot_get_image_size(); 815 error = get_swap_writer(&handle); 816 if (error) { 817 printk(KERN_ERR "PM: Cannot get swap writer\n"); 818 return error; 819 } 820 if (flags & SF_NOCOMPRESS_MODE) { 821 if (!enough_swap(pages, flags)) { 822 printk(KERN_ERR "PM: Not enough free swap\n"); 823 error = -ENOSPC; 824 goto out_finish; 825 } 826 } 827 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 828 error = snapshot_read_next(&snapshot); 829 if (error < PAGE_SIZE) { 830 if (error >= 0) 831 error = -EFAULT; 832 833 goto out_finish; 834 } 835 header = (struct swsusp_info *)data_of(snapshot); 836 error = swap_write_page(&handle, header, NULL); 837 if (!error) { 838 error = (flags & SF_NOCOMPRESS_MODE) ? 839 save_image(&handle, &snapshot, pages - 1) : 840 save_image_lzo(&handle, &snapshot, pages - 1); 841 } 842 out_finish: 843 error = swap_writer_finish(&handle, flags, error); 844 return error; 845 } 846 847 /** 848 * The following functions allow us to read data using a swap map 849 * in a file-alike way 850 */ 851 852 static void release_swap_reader(struct swap_map_handle *handle) 853 { 854 struct swap_map_page_list *tmp; 855 856 while (handle->maps) { 857 if (handle->maps->map) 858 free_page((unsigned long)handle->maps->map); 859 tmp = handle->maps; 860 handle->maps = handle->maps->next; 861 kfree(tmp); 862 } 863 handle->cur = NULL; 864 } 865 866 static int get_swap_reader(struct swap_map_handle *handle, 867 unsigned int *flags_p) 868 { 869 int error; 870 struct swap_map_page_list *tmp, *last; 871 sector_t offset; 872 873 *flags_p = swsusp_header->flags; 874 875 if (!swsusp_header->image) /* how can this happen? */ 876 return -EINVAL; 877 878 handle->cur = NULL; 879 last = handle->maps = NULL; 880 offset = swsusp_header->image; 881 while (offset) { 882 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL); 883 if (!tmp) { 884 release_swap_reader(handle); 885 return -ENOMEM; 886 } 887 memset(tmp, 0, sizeof(*tmp)); 888 if (!handle->maps) 889 handle->maps = tmp; 890 if (last) 891 last->next = tmp; 892 last = tmp; 893 894 tmp->map = (struct swap_map_page *) 895 __get_free_page(__GFP_WAIT | __GFP_HIGH); 896 if (!tmp->map) { 897 release_swap_reader(handle); 898 return -ENOMEM; 899 } 900 901 error = hib_bio_read_page(offset, tmp->map, NULL); 902 if (error) { 903 release_swap_reader(handle); 904 return error; 905 } 906 offset = tmp->map->next_swap; 907 } 908 handle->k = 0; 909 handle->cur = handle->maps->map; 910 return 0; 911 } 912 913 static int swap_read_page(struct swap_map_handle *handle, void *buf, 914 struct bio **bio_chain) 915 { 916 sector_t offset; 917 int error; 918 struct swap_map_page_list *tmp; 919 920 if (!handle->cur) 921 return -EINVAL; 922 offset = handle->cur->entries[handle->k]; 923 if (!offset) 924 return -EFAULT; 925 error = hib_bio_read_page(offset, buf, bio_chain); 926 if (error) 927 return error; 928 if (++handle->k >= MAP_PAGE_ENTRIES) { 929 handle->k = 0; 930 free_page((unsigned long)handle->maps->map); 931 tmp = handle->maps; 932 handle->maps = handle->maps->next; 933 kfree(tmp); 934 if (!handle->maps) 935 release_swap_reader(handle); 936 else 937 handle->cur = handle->maps->map; 938 } 939 return error; 940 } 941 942 static int swap_reader_finish(struct swap_map_handle *handle) 943 { 944 release_swap_reader(handle); 945 946 return 0; 947 } 948 949 /** 950 * load_image - load the image using the swap map handle 951 * @handle and the snapshot handle @snapshot 952 * (assume there are @nr_pages pages to load) 953 */ 954 955 static int load_image(struct swap_map_handle *handle, 956 struct snapshot_handle *snapshot, 957 unsigned int nr_to_read) 958 { 959 unsigned int m; 960 int ret = 0; 961 struct timeval start; 962 struct timeval stop; 963 struct bio *bio; 964 int err2; 965 unsigned nr_pages; 966 967 printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", 968 nr_to_read); 969 m = nr_to_read / 100; 970 if (!m) 971 m = 1; 972 nr_pages = 0; 973 bio = NULL; 974 do_gettimeofday(&start); 975 for ( ; ; ) { 976 ret = snapshot_write_next(snapshot); 977 if (ret <= 0) 978 break; 979 ret = swap_read_page(handle, data_of(*snapshot), &bio); 980 if (ret) 981 break; 982 if (snapshot->sync_read) 983 ret = hib_wait_on_bio_chain(&bio); 984 if (ret) 985 break; 986 if (!(nr_pages % m)) 987 printk("\b\b\b\b%3d%%", nr_pages / m); 988 nr_pages++; 989 } 990 err2 = hib_wait_on_bio_chain(&bio); 991 do_gettimeofday(&stop); 992 if (!ret) 993 ret = err2; 994 if (!ret) { 995 printk("\b\b\b\bdone\n"); 996 snapshot_write_finalize(snapshot); 997 if (!snapshot_image_loaded(snapshot)) 998 ret = -ENODATA; 999 } else 1000 printk("\n"); 1001 swsusp_show_speed(&start, &stop, nr_to_read, "Read"); 1002 return ret; 1003 } 1004 1005 /** 1006 * Structure used for LZO data decompression. 1007 */ 1008 struct dec_data { 1009 struct task_struct *thr; /* thread */ 1010 atomic_t ready; /* ready to start flag */ 1011 atomic_t stop; /* ready to stop flag */ 1012 int ret; /* return code */ 1013 wait_queue_head_t go; /* start decompression */ 1014 wait_queue_head_t done; /* decompression done */ 1015 size_t unc_len; /* uncompressed length */ 1016 size_t cmp_len; /* compressed length */ 1017 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 1018 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 1019 }; 1020 1021 /** 1022 * Deompression function that runs in its own thread. 1023 */ 1024 static int lzo_decompress_threadfn(void *data) 1025 { 1026 struct dec_data *d = data; 1027 1028 while (1) { 1029 wait_event(d->go, atomic_read(&d->ready) || 1030 kthread_should_stop()); 1031 if (kthread_should_stop()) { 1032 d->thr = NULL; 1033 d->ret = -1; 1034 atomic_set(&d->stop, 1); 1035 wake_up(&d->done); 1036 break; 1037 } 1038 atomic_set(&d->ready, 0); 1039 1040 d->unc_len = LZO_UNC_SIZE; 1041 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, 1042 d->unc, &d->unc_len); 1043 atomic_set(&d->stop, 1); 1044 wake_up(&d->done); 1045 } 1046 return 0; 1047 } 1048 1049 /** 1050 * load_image_lzo - Load compressed image data and decompress them with LZO. 1051 * @handle: Swap map handle to use for loading data. 1052 * @snapshot: Image to copy uncompressed data into. 1053 * @nr_to_read: Number of pages to load. 1054 */ 1055 static int load_image_lzo(struct swap_map_handle *handle, 1056 struct snapshot_handle *snapshot, 1057 unsigned int nr_to_read) 1058 { 1059 unsigned int m; 1060 int ret = 0; 1061 int eof = 0; 1062 struct bio *bio; 1063 struct timeval start; 1064 struct timeval stop; 1065 unsigned nr_pages; 1066 size_t off; 1067 unsigned i, thr, run_threads, nr_threads; 1068 unsigned ring = 0, pg = 0, ring_size = 0, 1069 have = 0, want, need, asked = 0; 1070 unsigned long read_pages; 1071 unsigned char **page = NULL; 1072 struct dec_data *data = NULL; 1073 struct crc_data *crc = NULL; 1074 1075 /* 1076 * We'll limit the number of threads for decompression to limit memory 1077 * footprint. 1078 */ 1079 nr_threads = num_online_cpus() - 1; 1080 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 1081 1082 page = vmalloc(sizeof(*page) * LZO_READ_PAGES); 1083 if (!page) { 1084 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 1085 ret = -ENOMEM; 1086 goto out_clean; 1087 } 1088 1089 data = vmalloc(sizeof(*data) * nr_threads); 1090 if (!data) { 1091 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 1092 ret = -ENOMEM; 1093 goto out_clean; 1094 } 1095 for (thr = 0; thr < nr_threads; thr++) 1096 memset(&data[thr], 0, offsetof(struct dec_data, go)); 1097 1098 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 1099 if (!crc) { 1100 printk(KERN_ERR "PM: Failed to allocate crc\n"); 1101 ret = -ENOMEM; 1102 goto out_clean; 1103 } 1104 memset(crc, 0, offsetof(struct crc_data, go)); 1105 1106 /* 1107 * Start the decompression threads. 1108 */ 1109 for (thr = 0; thr < nr_threads; thr++) { 1110 init_waitqueue_head(&data[thr].go); 1111 init_waitqueue_head(&data[thr].done); 1112 1113 data[thr].thr = kthread_run(lzo_decompress_threadfn, 1114 &data[thr], 1115 "image_decompress/%u", thr); 1116 if (IS_ERR(data[thr].thr)) { 1117 data[thr].thr = NULL; 1118 printk(KERN_ERR 1119 "PM: Cannot start decompression threads\n"); 1120 ret = -ENOMEM; 1121 goto out_clean; 1122 } 1123 } 1124 1125 /* 1126 * Start the CRC32 thread. 1127 */ 1128 init_waitqueue_head(&crc->go); 1129 init_waitqueue_head(&crc->done); 1130 1131 handle->crc32 = 0; 1132 crc->crc32 = &handle->crc32; 1133 for (thr = 0; thr < nr_threads; thr++) { 1134 crc->unc[thr] = data[thr].unc; 1135 crc->unc_len[thr] = &data[thr].unc_len; 1136 } 1137 1138 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 1139 if (IS_ERR(crc->thr)) { 1140 crc->thr = NULL; 1141 printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); 1142 ret = -ENOMEM; 1143 goto out_clean; 1144 } 1145 1146 /* 1147 * Adjust number of pages for read buffering, in case we are short. 1148 */ 1149 read_pages = (nr_free_pages() - snapshot_get_image_size()) >> 1; 1150 read_pages = clamp_val(read_pages, LZO_CMP_PAGES, LZO_READ_PAGES); 1151 1152 for (i = 0; i < read_pages; i++) { 1153 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ? 1154 __GFP_WAIT | __GFP_HIGH : 1155 __GFP_WAIT); 1156 if (!page[i]) { 1157 if (i < LZO_CMP_PAGES) { 1158 ring_size = i; 1159 printk(KERN_ERR 1160 "PM: Failed to allocate LZO pages\n"); 1161 ret = -ENOMEM; 1162 goto out_clean; 1163 } else { 1164 break; 1165 } 1166 } 1167 } 1168 want = ring_size = i; 1169 1170 printk(KERN_INFO 1171 "PM: Using %u thread(s) for decompression.\n" 1172 "PM: Loading and decompressing image data (%u pages) ... ", 1173 nr_threads, nr_to_read); 1174 m = nr_to_read / 100; 1175 if (!m) 1176 m = 1; 1177 nr_pages = 0; 1178 bio = NULL; 1179 do_gettimeofday(&start); 1180 1181 ret = snapshot_write_next(snapshot); 1182 if (ret <= 0) 1183 goto out_finish; 1184 1185 for(;;) { 1186 for (i = 0; !eof && i < want; i++) { 1187 ret = swap_read_page(handle, page[ring], &bio); 1188 if (ret) { 1189 /* 1190 * On real read error, finish. On end of data, 1191 * set EOF flag and just exit the read loop. 1192 */ 1193 if (handle->cur && 1194 handle->cur->entries[handle->k]) { 1195 goto out_finish; 1196 } else { 1197 eof = 1; 1198 break; 1199 } 1200 } 1201 if (++ring >= ring_size) 1202 ring = 0; 1203 } 1204 asked += i; 1205 want -= i; 1206 1207 /* 1208 * We are out of data, wait for some more. 1209 */ 1210 if (!have) { 1211 if (!asked) 1212 break; 1213 1214 ret = hib_wait_on_bio_chain(&bio); 1215 if (ret) 1216 goto out_finish; 1217 have += asked; 1218 asked = 0; 1219 if (eof) 1220 eof = 2; 1221 } 1222 1223 if (crc->run_threads) { 1224 wait_event(crc->done, atomic_read(&crc->stop)); 1225 atomic_set(&crc->stop, 0); 1226 crc->run_threads = 0; 1227 } 1228 1229 for (thr = 0; have && thr < nr_threads; thr++) { 1230 data[thr].cmp_len = *(size_t *)page[pg]; 1231 if (unlikely(!data[thr].cmp_len || 1232 data[thr].cmp_len > 1233 lzo1x_worst_compress(LZO_UNC_SIZE))) { 1234 printk(KERN_ERR 1235 "PM: Invalid LZO compressed length\n"); 1236 ret = -1; 1237 goto out_finish; 1238 } 1239 1240 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, 1241 PAGE_SIZE); 1242 if (need > have) { 1243 if (eof > 1) { 1244 ret = -1; 1245 goto out_finish; 1246 } 1247 break; 1248 } 1249 1250 for (off = 0; 1251 off < LZO_HEADER + data[thr].cmp_len; 1252 off += PAGE_SIZE) { 1253 memcpy(data[thr].cmp + off, 1254 page[pg], PAGE_SIZE); 1255 have--; 1256 want++; 1257 if (++pg >= ring_size) 1258 pg = 0; 1259 } 1260 1261 atomic_set(&data[thr].ready, 1); 1262 wake_up(&data[thr].go); 1263 } 1264 1265 /* 1266 * Wait for more data while we are decompressing. 1267 */ 1268 if (have < LZO_CMP_PAGES && asked) { 1269 ret = hib_wait_on_bio_chain(&bio); 1270 if (ret) 1271 goto out_finish; 1272 have += asked; 1273 asked = 0; 1274 if (eof) 1275 eof = 2; 1276 } 1277 1278 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 1279 wait_event(data[thr].done, 1280 atomic_read(&data[thr].stop)); 1281 atomic_set(&data[thr].stop, 0); 1282 1283 ret = data[thr].ret; 1284 1285 if (ret < 0) { 1286 printk(KERN_ERR 1287 "PM: LZO decompression failed\n"); 1288 goto out_finish; 1289 } 1290 1291 if (unlikely(!data[thr].unc_len || 1292 data[thr].unc_len > LZO_UNC_SIZE || 1293 data[thr].unc_len & (PAGE_SIZE - 1))) { 1294 printk(KERN_ERR 1295 "PM: Invalid LZO uncompressed length\n"); 1296 ret = -1; 1297 goto out_finish; 1298 } 1299 1300 for (off = 0; 1301 off < data[thr].unc_len; off += PAGE_SIZE) { 1302 memcpy(data_of(*snapshot), 1303 data[thr].unc + off, PAGE_SIZE); 1304 1305 if (!(nr_pages % m)) 1306 printk("\b\b\b\b%3d%%", nr_pages / m); 1307 nr_pages++; 1308 1309 ret = snapshot_write_next(snapshot); 1310 if (ret <= 0) { 1311 crc->run_threads = thr + 1; 1312 atomic_set(&crc->ready, 1); 1313 wake_up(&crc->go); 1314 goto out_finish; 1315 } 1316 } 1317 } 1318 1319 crc->run_threads = thr; 1320 atomic_set(&crc->ready, 1); 1321 wake_up(&crc->go); 1322 } 1323 1324 out_finish: 1325 if (crc->run_threads) { 1326 wait_event(crc->done, atomic_read(&crc->stop)); 1327 atomic_set(&crc->stop, 0); 1328 } 1329 do_gettimeofday(&stop); 1330 if (!ret) { 1331 printk("\b\b\b\bdone\n"); 1332 snapshot_write_finalize(snapshot); 1333 if (!snapshot_image_loaded(snapshot)) 1334 ret = -ENODATA; 1335 if (!ret) { 1336 if (swsusp_header->flags & SF_CRC32_MODE) { 1337 if(handle->crc32 != swsusp_header->crc32) { 1338 printk(KERN_ERR 1339 "PM: Invalid image CRC32!\n"); 1340 ret = -ENODATA; 1341 } 1342 } 1343 } 1344 } else 1345 printk("\n"); 1346 swsusp_show_speed(&start, &stop, nr_to_read, "Read"); 1347 out_clean: 1348 for (i = 0; i < ring_size; i++) 1349 free_page((unsigned long)page[i]); 1350 if (crc) { 1351 if (crc->thr) 1352 kthread_stop(crc->thr); 1353 kfree(crc); 1354 } 1355 if (data) { 1356 for (thr = 0; thr < nr_threads; thr++) 1357 if (data[thr].thr) 1358 kthread_stop(data[thr].thr); 1359 vfree(data); 1360 } 1361 if (page) vfree(page); 1362 1363 return ret; 1364 } 1365 1366 /** 1367 * swsusp_read - read the hibernation image. 1368 * @flags_p: flags passed by the "frozen" kernel in the image header should 1369 * be written into this memory location 1370 */ 1371 1372 int swsusp_read(unsigned int *flags_p) 1373 { 1374 int error; 1375 struct swap_map_handle handle; 1376 struct snapshot_handle snapshot; 1377 struct swsusp_info *header; 1378 1379 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 1380 error = snapshot_write_next(&snapshot); 1381 if (error < PAGE_SIZE) 1382 return error < 0 ? error : -EFAULT; 1383 header = (struct swsusp_info *)data_of(snapshot); 1384 error = get_swap_reader(&handle, flags_p); 1385 if (error) 1386 goto end; 1387 if (!error) 1388 error = swap_read_page(&handle, header, NULL); 1389 if (!error) { 1390 error = (*flags_p & SF_NOCOMPRESS_MODE) ? 1391 load_image(&handle, &snapshot, header->pages - 1) : 1392 load_image_lzo(&handle, &snapshot, header->pages - 1); 1393 } 1394 swap_reader_finish(&handle); 1395 end: 1396 if (!error) 1397 pr_debug("PM: Image successfully loaded\n"); 1398 else 1399 pr_debug("PM: Error %d resuming\n", error); 1400 return error; 1401 } 1402 1403 /** 1404 * swsusp_check - Check for swsusp signature in the resume device 1405 */ 1406 1407 int swsusp_check(void) 1408 { 1409 int error; 1410 1411 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, 1412 FMODE_READ, NULL); 1413 if (!IS_ERR(hib_resume_bdev)) { 1414 set_blocksize(hib_resume_bdev, PAGE_SIZE); 1415 clear_page(swsusp_header); 1416 error = hib_bio_read_page(swsusp_resume_block, 1417 swsusp_header, NULL); 1418 if (error) 1419 goto put; 1420 1421 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { 1422 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); 1423 /* Reset swap signature now */ 1424 error = hib_bio_write_page(swsusp_resume_block, 1425 swsusp_header, NULL); 1426 } else { 1427 error = -EINVAL; 1428 } 1429 1430 put: 1431 if (error) 1432 blkdev_put(hib_resume_bdev, FMODE_READ); 1433 else 1434 pr_debug("PM: Image signature found, resuming\n"); 1435 } else { 1436 error = PTR_ERR(hib_resume_bdev); 1437 } 1438 1439 if (error) 1440 pr_debug("PM: Image not found (code %d)\n", error); 1441 1442 return error; 1443 } 1444 1445 /** 1446 * swsusp_close - close swap device. 1447 */ 1448 1449 void swsusp_close(fmode_t mode) 1450 { 1451 if (IS_ERR(hib_resume_bdev)) { 1452 pr_debug("PM: Image device not initialised\n"); 1453 return; 1454 } 1455 1456 blkdev_put(hib_resume_bdev, mode); 1457 } 1458 1459 static int swsusp_header_init(void) 1460 { 1461 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); 1462 if (!swsusp_header) 1463 panic("Could not allocate memory for swsusp_header\n"); 1464 return 0; 1465 } 1466 1467 core_initcall(swsusp_header_init); 1468