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