1 // SPDX-License-Identifier: GPL-2.0-only 2 /* 3 * linux/kernel/power/swap.c 4 * 5 * This file provides functions for reading the suspend image from 6 * and writing it to a swap partition. 7 * 8 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz> 9 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> 10 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com> 11 */ 12 13 #define pr_fmt(fmt) "PM: " fmt 14 15 #include <linux/module.h> 16 #include <linux/file.h> 17 #include <linux/delay.h> 18 #include <linux/bitops.h> 19 #include <linux/genhd.h> 20 #include <linux/device.h> 21 #include <linux/bio.h> 22 #include <linux/blkdev.h> 23 #include <linux/swap.h> 24 #include <linux/swapops.h> 25 #include <linux/pm.h> 26 #include <linux/slab.h> 27 #include <linux/lzo.h> 28 #include <linux/vmalloc.h> 29 #include <linux/cpumask.h> 30 #include <linux/atomic.h> 31 #include <linux/kthread.h> 32 #include <linux/crc32.h> 33 #include <linux/ktime.h> 34 35 #include "power.h" 36 37 #define HIBERNATE_SIG "S1SUSPEND" 38 39 u32 swsusp_hardware_signature; 40 41 /* 42 * When reading an {un,}compressed image, we may restore pages in place, 43 * in which case some architectures need these pages cleaning before they 44 * can be executed. We don't know which pages these may be, so clean the lot. 45 */ 46 static bool clean_pages_on_read; 47 static bool clean_pages_on_decompress; 48 49 /* 50 * The swap map is a data structure used for keeping track of each page 51 * written to a swap partition. It consists of many swap_map_page 52 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries. 53 * These structures are stored on the swap and linked together with the 54 * help of the .next_swap member. 55 * 56 * The swap map is created during suspend. The swap map pages are 57 * allocated and populated one at a time, so we only need one memory 58 * page to set up the entire structure. 59 * 60 * During resume we pick up all swap_map_page structures into a list. 61 */ 62 63 #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) 64 65 /* 66 * Number of free pages that are not high. 67 */ 68 static inline unsigned long low_free_pages(void) 69 { 70 return nr_free_pages() - nr_free_highpages(); 71 } 72 73 /* 74 * Number of pages required to be kept free while writing the image. Always 75 * half of all available low pages before the writing starts. 76 */ 77 static inline unsigned long reqd_free_pages(void) 78 { 79 return low_free_pages() / 2; 80 } 81 82 struct swap_map_page { 83 sector_t entries[MAP_PAGE_ENTRIES]; 84 sector_t next_swap; 85 }; 86 87 struct swap_map_page_list { 88 struct swap_map_page *map; 89 struct swap_map_page_list *next; 90 }; 91 92 /** 93 * The swap_map_handle structure is used for handling swap in 94 * a file-alike way 95 */ 96 97 struct swap_map_handle { 98 struct swap_map_page *cur; 99 struct swap_map_page_list *maps; 100 sector_t cur_swap; 101 sector_t first_sector; 102 unsigned int k; 103 unsigned long reqd_free_pages; 104 u32 crc32; 105 }; 106 107 struct swsusp_header { 108 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) - 109 sizeof(u32) - sizeof(u32)]; 110 u32 hw_sig; 111 u32 crc32; 112 sector_t image; 113 unsigned int flags; /* Flags to pass to the "boot" kernel */ 114 char orig_sig[10]; 115 char sig[10]; 116 } __packed; 117 118 static struct swsusp_header *swsusp_header; 119 120 /** 121 * The following functions are used for tracing the allocated 122 * swap pages, so that they can be freed in case of an error. 123 */ 124 125 struct swsusp_extent { 126 struct rb_node node; 127 unsigned long start; 128 unsigned long end; 129 }; 130 131 static struct rb_root swsusp_extents = RB_ROOT; 132 133 static int swsusp_extents_insert(unsigned long swap_offset) 134 { 135 struct rb_node **new = &(swsusp_extents.rb_node); 136 struct rb_node *parent = NULL; 137 struct swsusp_extent *ext; 138 139 /* Figure out where to put the new node */ 140 while (*new) { 141 ext = rb_entry(*new, struct swsusp_extent, node); 142 parent = *new; 143 if (swap_offset < ext->start) { 144 /* Try to merge */ 145 if (swap_offset == ext->start - 1) { 146 ext->start--; 147 return 0; 148 } 149 new = &((*new)->rb_left); 150 } else if (swap_offset > ext->end) { 151 /* Try to merge */ 152 if (swap_offset == ext->end + 1) { 153 ext->end++; 154 return 0; 155 } 156 new = &((*new)->rb_right); 157 } else { 158 /* It already is in the tree */ 159 return -EINVAL; 160 } 161 } 162 /* Add the new node and rebalance the tree. */ 163 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); 164 if (!ext) 165 return -ENOMEM; 166 167 ext->start = swap_offset; 168 ext->end = swap_offset; 169 rb_link_node(&ext->node, parent, new); 170 rb_insert_color(&ext->node, &swsusp_extents); 171 return 0; 172 } 173 174 /** 175 * alloc_swapdev_block - allocate a swap page and register that it has 176 * been allocated, so that it can be freed in case of an error. 177 */ 178 179 sector_t alloc_swapdev_block(int swap) 180 { 181 unsigned long offset; 182 183 offset = swp_offset(get_swap_page_of_type(swap)); 184 if (offset) { 185 if (swsusp_extents_insert(offset)) 186 swap_free(swp_entry(swap, offset)); 187 else 188 return swapdev_block(swap, offset); 189 } 190 return 0; 191 } 192 193 /** 194 * free_all_swap_pages - free swap pages allocated for saving image data. 195 * It also frees the extents used to register which swap entries had been 196 * allocated. 197 */ 198 199 void free_all_swap_pages(int swap) 200 { 201 struct rb_node *node; 202 203 while ((node = swsusp_extents.rb_node)) { 204 struct swsusp_extent *ext; 205 unsigned long offset; 206 207 ext = rb_entry(node, struct swsusp_extent, node); 208 rb_erase(node, &swsusp_extents); 209 for (offset = ext->start; offset <= ext->end; offset++) 210 swap_free(swp_entry(swap, offset)); 211 212 kfree(ext); 213 } 214 } 215 216 int swsusp_swap_in_use(void) 217 { 218 return (swsusp_extents.rb_node != NULL); 219 } 220 221 /* 222 * General things 223 */ 224 225 static unsigned short root_swap = 0xffff; 226 static struct block_device *hib_resume_bdev; 227 228 struct hib_bio_batch { 229 atomic_t count; 230 wait_queue_head_t wait; 231 blk_status_t error; 232 struct blk_plug plug; 233 }; 234 235 static void hib_init_batch(struct hib_bio_batch *hb) 236 { 237 atomic_set(&hb->count, 0); 238 init_waitqueue_head(&hb->wait); 239 hb->error = BLK_STS_OK; 240 blk_start_plug(&hb->plug); 241 } 242 243 static void hib_finish_batch(struct hib_bio_batch *hb) 244 { 245 blk_finish_plug(&hb->plug); 246 } 247 248 static void hib_end_io(struct bio *bio) 249 { 250 struct hib_bio_batch *hb = bio->bi_private; 251 struct page *page = bio_first_page_all(bio); 252 253 if (bio->bi_status) { 254 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n", 255 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)), 256 (unsigned long long)bio->bi_iter.bi_sector); 257 } 258 259 if (bio_data_dir(bio) == WRITE) 260 put_page(page); 261 else if (clean_pages_on_read) 262 flush_icache_range((unsigned long)page_address(page), 263 (unsigned long)page_address(page) + PAGE_SIZE); 264 265 if (bio->bi_status && !hb->error) 266 hb->error = bio->bi_status; 267 if (atomic_dec_and_test(&hb->count)) 268 wake_up(&hb->wait); 269 270 bio_put(bio); 271 } 272 273 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr, 274 struct hib_bio_batch *hb) 275 { 276 struct page *page = virt_to_page(addr); 277 struct bio *bio; 278 int error = 0; 279 280 bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1); 281 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9); 282 bio_set_dev(bio, hib_resume_bdev); 283 bio_set_op_attrs(bio, op, op_flags); 284 285 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { 286 pr_err("Adding page to bio failed at %llu\n", 287 (unsigned long long)bio->bi_iter.bi_sector); 288 bio_put(bio); 289 return -EFAULT; 290 } 291 292 if (hb) { 293 bio->bi_end_io = hib_end_io; 294 bio->bi_private = hb; 295 atomic_inc(&hb->count); 296 submit_bio(bio); 297 } else { 298 error = submit_bio_wait(bio); 299 bio_put(bio); 300 } 301 302 return error; 303 } 304 305 static int hib_wait_io(struct hib_bio_batch *hb) 306 { 307 /* 308 * We are relying on the behavior of blk_plug that a thread with 309 * a plug will flush the plug list before sleeping. 310 */ 311 wait_event(hb->wait, atomic_read(&hb->count) == 0); 312 return blk_status_to_errno(hb->error); 313 } 314 315 /* 316 * Saving part 317 */ 318 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) 319 { 320 int error; 321 322 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block, 323 swsusp_header, NULL); 324 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || 325 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { 326 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); 327 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10); 328 swsusp_header->image = handle->first_sector; 329 if (swsusp_hardware_signature) { 330 swsusp_header->hw_sig = swsusp_hardware_signature; 331 flags |= SF_HW_SIG; 332 } 333 swsusp_header->flags = flags; 334 if (flags & SF_CRC32_MODE) 335 swsusp_header->crc32 = handle->crc32; 336 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, 337 swsusp_resume_block, swsusp_header, NULL); 338 } else { 339 pr_err("Swap header not found!\n"); 340 error = -ENODEV; 341 } 342 return error; 343 } 344 345 /** 346 * swsusp_swap_check - check if the resume device is a swap device 347 * and get its index (if so) 348 * 349 * This is called before saving image 350 */ 351 static int swsusp_swap_check(void) 352 { 353 int res; 354 355 if (swsusp_resume_device) 356 res = swap_type_of(swsusp_resume_device, swsusp_resume_block); 357 else 358 res = find_first_swap(&swsusp_resume_device); 359 if (res < 0) 360 return res; 361 root_swap = res; 362 363 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE, 364 NULL); 365 if (IS_ERR(hib_resume_bdev)) 366 return PTR_ERR(hib_resume_bdev); 367 368 res = set_blocksize(hib_resume_bdev, PAGE_SIZE); 369 if (res < 0) 370 blkdev_put(hib_resume_bdev, FMODE_WRITE); 371 372 return res; 373 } 374 375 /** 376 * write_page - Write one page to given swap location. 377 * @buf: Address we're writing. 378 * @offset: Offset of the swap page we're writing to. 379 * @hb: bio completion batch 380 */ 381 382 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb) 383 { 384 void *src; 385 int ret; 386 387 if (!offset) 388 return -ENOSPC; 389 390 if (hb) { 391 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN | 392 __GFP_NORETRY); 393 if (src) { 394 copy_page(src, buf); 395 } else { 396 ret = hib_wait_io(hb); /* Free pages */ 397 if (ret) 398 return ret; 399 src = (void *)__get_free_page(GFP_NOIO | 400 __GFP_NOWARN | 401 __GFP_NORETRY); 402 if (src) { 403 copy_page(src, buf); 404 } else { 405 WARN_ON_ONCE(1); 406 hb = NULL; /* Go synchronous */ 407 src = buf; 408 } 409 } 410 } else { 411 src = buf; 412 } 413 return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb); 414 } 415 416 static void release_swap_writer(struct swap_map_handle *handle) 417 { 418 if (handle->cur) 419 free_page((unsigned long)handle->cur); 420 handle->cur = NULL; 421 } 422 423 static int get_swap_writer(struct swap_map_handle *handle) 424 { 425 int ret; 426 427 ret = swsusp_swap_check(); 428 if (ret) { 429 if (ret != -ENOSPC) 430 pr_err("Cannot find swap device, try swapon -a\n"); 431 return ret; 432 } 433 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); 434 if (!handle->cur) { 435 ret = -ENOMEM; 436 goto err_close; 437 } 438 handle->cur_swap = alloc_swapdev_block(root_swap); 439 if (!handle->cur_swap) { 440 ret = -ENOSPC; 441 goto err_rel; 442 } 443 handle->k = 0; 444 handle->reqd_free_pages = reqd_free_pages(); 445 handle->first_sector = handle->cur_swap; 446 return 0; 447 err_rel: 448 release_swap_writer(handle); 449 err_close: 450 swsusp_close(FMODE_WRITE); 451 return ret; 452 } 453 454 static int swap_write_page(struct swap_map_handle *handle, void *buf, 455 struct hib_bio_batch *hb) 456 { 457 int error = 0; 458 sector_t offset; 459 460 if (!handle->cur) 461 return -EINVAL; 462 offset = alloc_swapdev_block(root_swap); 463 error = write_page(buf, offset, hb); 464 if (error) 465 return error; 466 handle->cur->entries[handle->k++] = offset; 467 if (handle->k >= MAP_PAGE_ENTRIES) { 468 offset = alloc_swapdev_block(root_swap); 469 if (!offset) 470 return -ENOSPC; 471 handle->cur->next_swap = offset; 472 error = write_page(handle->cur, handle->cur_swap, hb); 473 if (error) 474 goto out; 475 clear_page(handle->cur); 476 handle->cur_swap = offset; 477 handle->k = 0; 478 479 if (hb && low_free_pages() <= handle->reqd_free_pages) { 480 error = hib_wait_io(hb); 481 if (error) 482 goto out; 483 /* 484 * Recalculate the number of required free pages, to 485 * make sure we never take more than half. 486 */ 487 handle->reqd_free_pages = reqd_free_pages(); 488 } 489 } 490 out: 491 return error; 492 } 493 494 static int flush_swap_writer(struct swap_map_handle *handle) 495 { 496 if (handle->cur && handle->cur_swap) 497 return write_page(handle->cur, handle->cur_swap, NULL); 498 else 499 return -EINVAL; 500 } 501 502 static int swap_writer_finish(struct swap_map_handle *handle, 503 unsigned int flags, int error) 504 { 505 if (!error) { 506 pr_info("S"); 507 error = mark_swapfiles(handle, flags); 508 pr_cont("|\n"); 509 flush_swap_writer(handle); 510 } 511 512 if (error) 513 free_all_swap_pages(root_swap); 514 release_swap_writer(handle); 515 swsusp_close(FMODE_WRITE); 516 517 return error; 518 } 519 520 /* We need to remember how much compressed data we need to read. */ 521 #define LZO_HEADER sizeof(size_t) 522 523 /* Number of pages/bytes we'll compress at one time. */ 524 #define LZO_UNC_PAGES 32 525 #define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) 526 527 /* Number of pages/bytes we need for compressed data (worst case). */ 528 #define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ 529 LZO_HEADER, PAGE_SIZE) 530 #define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) 531 532 /* Maximum number of threads for compression/decompression. */ 533 #define LZO_THREADS 3 534 535 /* Minimum/maximum number of pages for read buffering. */ 536 #define LZO_MIN_RD_PAGES 1024 537 #define LZO_MAX_RD_PAGES 8192 538 539 540 /** 541 * save_image - save the suspend image data 542 */ 543 544 static int save_image(struct swap_map_handle *handle, 545 struct snapshot_handle *snapshot, 546 unsigned int nr_to_write) 547 { 548 unsigned int m; 549 int ret; 550 int nr_pages; 551 int err2; 552 struct hib_bio_batch hb; 553 ktime_t start; 554 ktime_t stop; 555 556 hib_init_batch(&hb); 557 558 pr_info("Saving image data pages (%u pages)...\n", 559 nr_to_write); 560 m = nr_to_write / 10; 561 if (!m) 562 m = 1; 563 nr_pages = 0; 564 start = ktime_get(); 565 while (1) { 566 ret = snapshot_read_next(snapshot); 567 if (ret <= 0) 568 break; 569 ret = swap_write_page(handle, data_of(*snapshot), &hb); 570 if (ret) 571 break; 572 if (!(nr_pages % m)) 573 pr_info("Image saving progress: %3d%%\n", 574 nr_pages / m * 10); 575 nr_pages++; 576 } 577 err2 = hib_wait_io(&hb); 578 hib_finish_batch(&hb); 579 stop = ktime_get(); 580 if (!ret) 581 ret = err2; 582 if (!ret) 583 pr_info("Image saving done\n"); 584 swsusp_show_speed(start, stop, nr_to_write, "Wrote"); 585 return ret; 586 } 587 588 /** 589 * Structure used for CRC32. 590 */ 591 struct crc_data { 592 struct task_struct *thr; /* thread */ 593 atomic_t ready; /* ready to start flag */ 594 atomic_t stop; /* ready to stop flag */ 595 unsigned run_threads; /* nr current threads */ 596 wait_queue_head_t go; /* start crc update */ 597 wait_queue_head_t done; /* crc update done */ 598 u32 *crc32; /* points to handle's crc32 */ 599 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */ 600 unsigned char *unc[LZO_THREADS]; /* uncompressed data */ 601 }; 602 603 /** 604 * CRC32 update function that runs in its own thread. 605 */ 606 static int crc32_threadfn(void *data) 607 { 608 struct crc_data *d = data; 609 unsigned i; 610 611 while (1) { 612 wait_event(d->go, atomic_read(&d->ready) || 613 kthread_should_stop()); 614 if (kthread_should_stop()) { 615 d->thr = NULL; 616 atomic_set(&d->stop, 1); 617 wake_up(&d->done); 618 break; 619 } 620 atomic_set(&d->ready, 0); 621 622 for (i = 0; i < d->run_threads; i++) 623 *d->crc32 = crc32_le(*d->crc32, 624 d->unc[i], *d->unc_len[i]); 625 atomic_set(&d->stop, 1); 626 wake_up(&d->done); 627 } 628 return 0; 629 } 630 /** 631 * Structure used for LZO data compression. 632 */ 633 struct cmp_data { 634 struct task_struct *thr; /* thread */ 635 atomic_t ready; /* ready to start flag */ 636 atomic_t stop; /* ready to stop flag */ 637 int ret; /* return code */ 638 wait_queue_head_t go; /* start compression */ 639 wait_queue_head_t done; /* compression done */ 640 size_t unc_len; /* uncompressed length */ 641 size_t cmp_len; /* compressed length */ 642 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 643 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 644 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */ 645 }; 646 647 /** 648 * Compression function that runs in its own thread. 649 */ 650 static int lzo_compress_threadfn(void *data) 651 { 652 struct cmp_data *d = data; 653 654 while (1) { 655 wait_event(d->go, atomic_read(&d->ready) || 656 kthread_should_stop()); 657 if (kthread_should_stop()) { 658 d->thr = NULL; 659 d->ret = -1; 660 atomic_set(&d->stop, 1); 661 wake_up(&d->done); 662 break; 663 } 664 atomic_set(&d->ready, 0); 665 666 d->ret = lzo1x_1_compress(d->unc, d->unc_len, 667 d->cmp + LZO_HEADER, &d->cmp_len, 668 d->wrk); 669 atomic_set(&d->stop, 1); 670 wake_up(&d->done); 671 } 672 return 0; 673 } 674 675 /** 676 * save_image_lzo - Save the suspend image data compressed with LZO. 677 * @handle: Swap map handle to use for saving the image. 678 * @snapshot: Image to read data from. 679 * @nr_to_write: Number of pages to save. 680 */ 681 static int save_image_lzo(struct swap_map_handle *handle, 682 struct snapshot_handle *snapshot, 683 unsigned int nr_to_write) 684 { 685 unsigned int m; 686 int ret = 0; 687 int nr_pages; 688 int err2; 689 struct hib_bio_batch hb; 690 ktime_t start; 691 ktime_t stop; 692 size_t off; 693 unsigned thr, run_threads, nr_threads; 694 unsigned char *page = NULL; 695 struct cmp_data *data = NULL; 696 struct crc_data *crc = NULL; 697 698 hib_init_batch(&hb); 699 700 /* 701 * We'll limit the number of threads for compression to limit memory 702 * footprint. 703 */ 704 nr_threads = num_online_cpus() - 1; 705 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 706 707 page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH); 708 if (!page) { 709 pr_err("Failed to allocate LZO page\n"); 710 ret = -ENOMEM; 711 goto out_clean; 712 } 713 714 data = vzalloc(array_size(nr_threads, sizeof(*data))); 715 if (!data) { 716 pr_err("Failed to allocate LZO data\n"); 717 ret = -ENOMEM; 718 goto out_clean; 719 } 720 721 crc = kzalloc(sizeof(*crc), GFP_KERNEL); 722 if (!crc) { 723 pr_err("Failed to allocate crc\n"); 724 ret = -ENOMEM; 725 goto out_clean; 726 } 727 728 /* 729 * Start the compression threads. 730 */ 731 for (thr = 0; thr < nr_threads; thr++) { 732 init_waitqueue_head(&data[thr].go); 733 init_waitqueue_head(&data[thr].done); 734 735 data[thr].thr = kthread_run(lzo_compress_threadfn, 736 &data[thr], 737 "image_compress/%u", thr); 738 if (IS_ERR(data[thr].thr)) { 739 data[thr].thr = NULL; 740 pr_err("Cannot start compression threads\n"); 741 ret = -ENOMEM; 742 goto out_clean; 743 } 744 } 745 746 /* 747 * Start the CRC32 thread. 748 */ 749 init_waitqueue_head(&crc->go); 750 init_waitqueue_head(&crc->done); 751 752 handle->crc32 = 0; 753 crc->crc32 = &handle->crc32; 754 for (thr = 0; thr < nr_threads; thr++) { 755 crc->unc[thr] = data[thr].unc; 756 crc->unc_len[thr] = &data[thr].unc_len; 757 } 758 759 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 760 if (IS_ERR(crc->thr)) { 761 crc->thr = NULL; 762 pr_err("Cannot start CRC32 thread\n"); 763 ret = -ENOMEM; 764 goto out_clean; 765 } 766 767 /* 768 * Adjust the number of required free pages after all allocations have 769 * been done. We don't want to run out of pages when writing. 770 */ 771 handle->reqd_free_pages = reqd_free_pages(); 772 773 pr_info("Using %u thread(s) for compression\n", nr_threads); 774 pr_info("Compressing and saving image data (%u pages)...\n", 775 nr_to_write); 776 m = nr_to_write / 10; 777 if (!m) 778 m = 1; 779 nr_pages = 0; 780 start = ktime_get(); 781 for (;;) { 782 for (thr = 0; thr < nr_threads; thr++) { 783 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) { 784 ret = snapshot_read_next(snapshot); 785 if (ret < 0) 786 goto out_finish; 787 788 if (!ret) 789 break; 790 791 memcpy(data[thr].unc + off, 792 data_of(*snapshot), PAGE_SIZE); 793 794 if (!(nr_pages % m)) 795 pr_info("Image saving progress: %3d%%\n", 796 nr_pages / m * 10); 797 nr_pages++; 798 } 799 if (!off) 800 break; 801 802 data[thr].unc_len = off; 803 804 atomic_set(&data[thr].ready, 1); 805 wake_up(&data[thr].go); 806 } 807 808 if (!thr) 809 break; 810 811 crc->run_threads = thr; 812 atomic_set(&crc->ready, 1); 813 wake_up(&crc->go); 814 815 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 816 wait_event(data[thr].done, 817 atomic_read(&data[thr].stop)); 818 atomic_set(&data[thr].stop, 0); 819 820 ret = data[thr].ret; 821 822 if (ret < 0) { 823 pr_err("LZO compression failed\n"); 824 goto out_finish; 825 } 826 827 if (unlikely(!data[thr].cmp_len || 828 data[thr].cmp_len > 829 lzo1x_worst_compress(data[thr].unc_len))) { 830 pr_err("Invalid LZO compressed length\n"); 831 ret = -1; 832 goto out_finish; 833 } 834 835 *(size_t *)data[thr].cmp = data[thr].cmp_len; 836 837 /* 838 * Given we are writing one page at a time to disk, we 839 * copy that much from the buffer, although the last 840 * bit will likely be smaller than full page. This is 841 * OK - we saved the length of the compressed data, so 842 * any garbage at the end will be discarded when we 843 * read it. 844 */ 845 for (off = 0; 846 off < LZO_HEADER + data[thr].cmp_len; 847 off += PAGE_SIZE) { 848 memcpy(page, data[thr].cmp + off, PAGE_SIZE); 849 850 ret = swap_write_page(handle, page, &hb); 851 if (ret) 852 goto out_finish; 853 } 854 } 855 856 wait_event(crc->done, atomic_read(&crc->stop)); 857 atomic_set(&crc->stop, 0); 858 } 859 860 out_finish: 861 err2 = hib_wait_io(&hb); 862 stop = ktime_get(); 863 if (!ret) 864 ret = err2; 865 if (!ret) 866 pr_info("Image saving done\n"); 867 swsusp_show_speed(start, stop, nr_to_write, "Wrote"); 868 out_clean: 869 hib_finish_batch(&hb); 870 if (crc) { 871 if (crc->thr) 872 kthread_stop(crc->thr); 873 kfree(crc); 874 } 875 if (data) { 876 for (thr = 0; thr < nr_threads; thr++) 877 if (data[thr].thr) 878 kthread_stop(data[thr].thr); 879 vfree(data); 880 } 881 if (page) free_page((unsigned long)page); 882 883 return ret; 884 } 885 886 /** 887 * enough_swap - Make sure we have enough swap to save the image. 888 * 889 * Returns TRUE or FALSE after checking the total amount of swap 890 * space available from the resume partition. 891 */ 892 893 static int enough_swap(unsigned int nr_pages) 894 { 895 unsigned int free_swap = count_swap_pages(root_swap, 1); 896 unsigned int required; 897 898 pr_debug("Free swap pages: %u\n", free_swap); 899 900 required = PAGES_FOR_IO + nr_pages; 901 return free_swap > required; 902 } 903 904 /** 905 * swsusp_write - Write entire image and metadata. 906 * @flags: flags to pass to the "boot" kernel in the image header 907 * 908 * It is important _NOT_ to umount filesystems at this point. We want 909 * them synced (in case something goes wrong) but we DO not want to mark 910 * filesystem clean: it is not. (And it does not matter, if we resume 911 * correctly, we'll mark system clean, anyway.) 912 */ 913 914 int swsusp_write(unsigned int flags) 915 { 916 struct swap_map_handle handle; 917 struct snapshot_handle snapshot; 918 struct swsusp_info *header; 919 unsigned long pages; 920 int error; 921 922 pages = snapshot_get_image_size(); 923 error = get_swap_writer(&handle); 924 if (error) { 925 pr_err("Cannot get swap writer\n"); 926 return error; 927 } 928 if (flags & SF_NOCOMPRESS_MODE) { 929 if (!enough_swap(pages)) { 930 pr_err("Not enough free swap\n"); 931 error = -ENOSPC; 932 goto out_finish; 933 } 934 } 935 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 936 error = snapshot_read_next(&snapshot); 937 if (error < (int)PAGE_SIZE) { 938 if (error >= 0) 939 error = -EFAULT; 940 941 goto out_finish; 942 } 943 header = (struct swsusp_info *)data_of(snapshot); 944 error = swap_write_page(&handle, header, NULL); 945 if (!error) { 946 error = (flags & SF_NOCOMPRESS_MODE) ? 947 save_image(&handle, &snapshot, pages - 1) : 948 save_image_lzo(&handle, &snapshot, pages - 1); 949 } 950 out_finish: 951 error = swap_writer_finish(&handle, flags, error); 952 return error; 953 } 954 955 /** 956 * The following functions allow us to read data using a swap map 957 * in a file-alike way 958 */ 959 960 static void release_swap_reader(struct swap_map_handle *handle) 961 { 962 struct swap_map_page_list *tmp; 963 964 while (handle->maps) { 965 if (handle->maps->map) 966 free_page((unsigned long)handle->maps->map); 967 tmp = handle->maps; 968 handle->maps = handle->maps->next; 969 kfree(tmp); 970 } 971 handle->cur = NULL; 972 } 973 974 static int get_swap_reader(struct swap_map_handle *handle, 975 unsigned int *flags_p) 976 { 977 int error; 978 struct swap_map_page_list *tmp, *last; 979 sector_t offset; 980 981 *flags_p = swsusp_header->flags; 982 983 if (!swsusp_header->image) /* how can this happen? */ 984 return -EINVAL; 985 986 handle->cur = NULL; 987 last = handle->maps = NULL; 988 offset = swsusp_header->image; 989 while (offset) { 990 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL); 991 if (!tmp) { 992 release_swap_reader(handle); 993 return -ENOMEM; 994 } 995 if (!handle->maps) 996 handle->maps = tmp; 997 if (last) 998 last->next = tmp; 999 last = tmp; 1000 1001 tmp->map = (struct swap_map_page *) 1002 __get_free_page(GFP_NOIO | __GFP_HIGH); 1003 if (!tmp->map) { 1004 release_swap_reader(handle); 1005 return -ENOMEM; 1006 } 1007 1008 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL); 1009 if (error) { 1010 release_swap_reader(handle); 1011 return error; 1012 } 1013 offset = tmp->map->next_swap; 1014 } 1015 handle->k = 0; 1016 handle->cur = handle->maps->map; 1017 return 0; 1018 } 1019 1020 static int swap_read_page(struct swap_map_handle *handle, void *buf, 1021 struct hib_bio_batch *hb) 1022 { 1023 sector_t offset; 1024 int error; 1025 struct swap_map_page_list *tmp; 1026 1027 if (!handle->cur) 1028 return -EINVAL; 1029 offset = handle->cur->entries[handle->k]; 1030 if (!offset) 1031 return -EFAULT; 1032 error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb); 1033 if (error) 1034 return error; 1035 if (++handle->k >= MAP_PAGE_ENTRIES) { 1036 handle->k = 0; 1037 free_page((unsigned long)handle->maps->map); 1038 tmp = handle->maps; 1039 handle->maps = handle->maps->next; 1040 kfree(tmp); 1041 if (!handle->maps) 1042 release_swap_reader(handle); 1043 else 1044 handle->cur = handle->maps->map; 1045 } 1046 return error; 1047 } 1048 1049 static int swap_reader_finish(struct swap_map_handle *handle) 1050 { 1051 release_swap_reader(handle); 1052 1053 return 0; 1054 } 1055 1056 /** 1057 * load_image - load the image using the swap map handle 1058 * @handle and the snapshot handle @snapshot 1059 * (assume there are @nr_pages pages to load) 1060 */ 1061 1062 static int load_image(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 ktime_t start; 1069 ktime_t stop; 1070 struct hib_bio_batch hb; 1071 int err2; 1072 unsigned nr_pages; 1073 1074 hib_init_batch(&hb); 1075 1076 clean_pages_on_read = true; 1077 pr_info("Loading image data pages (%u pages)...\n", nr_to_read); 1078 m = nr_to_read / 10; 1079 if (!m) 1080 m = 1; 1081 nr_pages = 0; 1082 start = ktime_get(); 1083 for ( ; ; ) { 1084 ret = snapshot_write_next(snapshot); 1085 if (ret <= 0) 1086 break; 1087 ret = swap_read_page(handle, data_of(*snapshot), &hb); 1088 if (ret) 1089 break; 1090 if (snapshot->sync_read) 1091 ret = hib_wait_io(&hb); 1092 if (ret) 1093 break; 1094 if (!(nr_pages % m)) 1095 pr_info("Image loading progress: %3d%%\n", 1096 nr_pages / m * 10); 1097 nr_pages++; 1098 } 1099 err2 = hib_wait_io(&hb); 1100 hib_finish_batch(&hb); 1101 stop = ktime_get(); 1102 if (!ret) 1103 ret = err2; 1104 if (!ret) { 1105 pr_info("Image loading done\n"); 1106 snapshot_write_finalize(snapshot); 1107 if (!snapshot_image_loaded(snapshot)) 1108 ret = -ENODATA; 1109 } 1110 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1111 return ret; 1112 } 1113 1114 /** 1115 * Structure used for LZO data decompression. 1116 */ 1117 struct dec_data { 1118 struct task_struct *thr; /* thread */ 1119 atomic_t ready; /* ready to start flag */ 1120 atomic_t stop; /* ready to stop flag */ 1121 int ret; /* return code */ 1122 wait_queue_head_t go; /* start decompression */ 1123 wait_queue_head_t done; /* decompression done */ 1124 size_t unc_len; /* uncompressed length */ 1125 size_t cmp_len; /* compressed length */ 1126 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 1127 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 1128 }; 1129 1130 /** 1131 * Decompression function that runs in its own thread. 1132 */ 1133 static int lzo_decompress_threadfn(void *data) 1134 { 1135 struct dec_data *d = data; 1136 1137 while (1) { 1138 wait_event(d->go, atomic_read(&d->ready) || 1139 kthread_should_stop()); 1140 if (kthread_should_stop()) { 1141 d->thr = NULL; 1142 d->ret = -1; 1143 atomic_set(&d->stop, 1); 1144 wake_up(&d->done); 1145 break; 1146 } 1147 atomic_set(&d->ready, 0); 1148 1149 d->unc_len = LZO_UNC_SIZE; 1150 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, 1151 d->unc, &d->unc_len); 1152 if (clean_pages_on_decompress) 1153 flush_icache_range((unsigned long)d->unc, 1154 (unsigned long)d->unc + d->unc_len); 1155 1156 atomic_set(&d->stop, 1); 1157 wake_up(&d->done); 1158 } 1159 return 0; 1160 } 1161 1162 /** 1163 * load_image_lzo - Load compressed image data and decompress them with LZO. 1164 * @handle: Swap map handle to use for loading data. 1165 * @snapshot: Image to copy uncompressed data into. 1166 * @nr_to_read: Number of pages to load. 1167 */ 1168 static int load_image_lzo(struct swap_map_handle *handle, 1169 struct snapshot_handle *snapshot, 1170 unsigned int nr_to_read) 1171 { 1172 unsigned int m; 1173 int ret = 0; 1174 int eof = 0; 1175 struct hib_bio_batch hb; 1176 ktime_t start; 1177 ktime_t stop; 1178 unsigned nr_pages; 1179 size_t off; 1180 unsigned i, thr, run_threads, nr_threads; 1181 unsigned ring = 0, pg = 0, ring_size = 0, 1182 have = 0, want, need, asked = 0; 1183 unsigned long read_pages = 0; 1184 unsigned char **page = NULL; 1185 struct dec_data *data = NULL; 1186 struct crc_data *crc = NULL; 1187 1188 hib_init_batch(&hb); 1189 1190 /* 1191 * We'll limit the number of threads for decompression to limit memory 1192 * footprint. 1193 */ 1194 nr_threads = num_online_cpus() - 1; 1195 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 1196 1197 page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page))); 1198 if (!page) { 1199 pr_err("Failed to allocate LZO page\n"); 1200 ret = -ENOMEM; 1201 goto out_clean; 1202 } 1203 1204 data = vzalloc(array_size(nr_threads, sizeof(*data))); 1205 if (!data) { 1206 pr_err("Failed to allocate LZO data\n"); 1207 ret = -ENOMEM; 1208 goto out_clean; 1209 } 1210 1211 crc = kzalloc(sizeof(*crc), GFP_KERNEL); 1212 if (!crc) { 1213 pr_err("Failed to allocate crc\n"); 1214 ret = -ENOMEM; 1215 goto out_clean; 1216 } 1217 1218 clean_pages_on_decompress = true; 1219 1220 /* 1221 * Start the decompression threads. 1222 */ 1223 for (thr = 0; thr < nr_threads; thr++) { 1224 init_waitqueue_head(&data[thr].go); 1225 init_waitqueue_head(&data[thr].done); 1226 1227 data[thr].thr = kthread_run(lzo_decompress_threadfn, 1228 &data[thr], 1229 "image_decompress/%u", thr); 1230 if (IS_ERR(data[thr].thr)) { 1231 data[thr].thr = NULL; 1232 pr_err("Cannot start decompression threads\n"); 1233 ret = -ENOMEM; 1234 goto out_clean; 1235 } 1236 } 1237 1238 /* 1239 * Start the CRC32 thread. 1240 */ 1241 init_waitqueue_head(&crc->go); 1242 init_waitqueue_head(&crc->done); 1243 1244 handle->crc32 = 0; 1245 crc->crc32 = &handle->crc32; 1246 for (thr = 0; thr < nr_threads; thr++) { 1247 crc->unc[thr] = data[thr].unc; 1248 crc->unc_len[thr] = &data[thr].unc_len; 1249 } 1250 1251 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 1252 if (IS_ERR(crc->thr)) { 1253 crc->thr = NULL; 1254 pr_err("Cannot start CRC32 thread\n"); 1255 ret = -ENOMEM; 1256 goto out_clean; 1257 } 1258 1259 /* 1260 * Set the number of pages for read buffering. 1261 * This is complete guesswork, because we'll only know the real 1262 * picture once prepare_image() is called, which is much later on 1263 * during the image load phase. We'll assume the worst case and 1264 * say that none of the image pages are from high memory. 1265 */ 1266 if (low_free_pages() > snapshot_get_image_size()) 1267 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2; 1268 read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES); 1269 1270 for (i = 0; i < read_pages; i++) { 1271 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ? 1272 GFP_NOIO | __GFP_HIGH : 1273 GFP_NOIO | __GFP_NOWARN | 1274 __GFP_NORETRY); 1275 1276 if (!page[i]) { 1277 if (i < LZO_CMP_PAGES) { 1278 ring_size = i; 1279 pr_err("Failed to allocate LZO pages\n"); 1280 ret = -ENOMEM; 1281 goto out_clean; 1282 } else { 1283 break; 1284 } 1285 } 1286 } 1287 want = ring_size = i; 1288 1289 pr_info("Using %u thread(s) for decompression\n", nr_threads); 1290 pr_info("Loading and decompressing image data (%u pages)...\n", 1291 nr_to_read); 1292 m = nr_to_read / 10; 1293 if (!m) 1294 m = 1; 1295 nr_pages = 0; 1296 start = ktime_get(); 1297 1298 ret = snapshot_write_next(snapshot); 1299 if (ret <= 0) 1300 goto out_finish; 1301 1302 for(;;) { 1303 for (i = 0; !eof && i < want; i++) { 1304 ret = swap_read_page(handle, page[ring], &hb); 1305 if (ret) { 1306 /* 1307 * On real read error, finish. On end of data, 1308 * set EOF flag and just exit the read loop. 1309 */ 1310 if (handle->cur && 1311 handle->cur->entries[handle->k]) { 1312 goto out_finish; 1313 } else { 1314 eof = 1; 1315 break; 1316 } 1317 } 1318 if (++ring >= ring_size) 1319 ring = 0; 1320 } 1321 asked += i; 1322 want -= i; 1323 1324 /* 1325 * We are out of data, wait for some more. 1326 */ 1327 if (!have) { 1328 if (!asked) 1329 break; 1330 1331 ret = hib_wait_io(&hb); 1332 if (ret) 1333 goto out_finish; 1334 have += asked; 1335 asked = 0; 1336 if (eof) 1337 eof = 2; 1338 } 1339 1340 if (crc->run_threads) { 1341 wait_event(crc->done, atomic_read(&crc->stop)); 1342 atomic_set(&crc->stop, 0); 1343 crc->run_threads = 0; 1344 } 1345 1346 for (thr = 0; have && thr < nr_threads; thr++) { 1347 data[thr].cmp_len = *(size_t *)page[pg]; 1348 if (unlikely(!data[thr].cmp_len || 1349 data[thr].cmp_len > 1350 lzo1x_worst_compress(LZO_UNC_SIZE))) { 1351 pr_err("Invalid LZO compressed length\n"); 1352 ret = -1; 1353 goto out_finish; 1354 } 1355 1356 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, 1357 PAGE_SIZE); 1358 if (need > have) { 1359 if (eof > 1) { 1360 ret = -1; 1361 goto out_finish; 1362 } 1363 break; 1364 } 1365 1366 for (off = 0; 1367 off < LZO_HEADER + data[thr].cmp_len; 1368 off += PAGE_SIZE) { 1369 memcpy(data[thr].cmp + off, 1370 page[pg], PAGE_SIZE); 1371 have--; 1372 want++; 1373 if (++pg >= ring_size) 1374 pg = 0; 1375 } 1376 1377 atomic_set(&data[thr].ready, 1); 1378 wake_up(&data[thr].go); 1379 } 1380 1381 /* 1382 * Wait for more data while we are decompressing. 1383 */ 1384 if (have < LZO_CMP_PAGES && asked) { 1385 ret = hib_wait_io(&hb); 1386 if (ret) 1387 goto out_finish; 1388 have += asked; 1389 asked = 0; 1390 if (eof) 1391 eof = 2; 1392 } 1393 1394 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 1395 wait_event(data[thr].done, 1396 atomic_read(&data[thr].stop)); 1397 atomic_set(&data[thr].stop, 0); 1398 1399 ret = data[thr].ret; 1400 1401 if (ret < 0) { 1402 pr_err("LZO decompression failed\n"); 1403 goto out_finish; 1404 } 1405 1406 if (unlikely(!data[thr].unc_len || 1407 data[thr].unc_len > LZO_UNC_SIZE || 1408 data[thr].unc_len & (PAGE_SIZE - 1))) { 1409 pr_err("Invalid LZO uncompressed length\n"); 1410 ret = -1; 1411 goto out_finish; 1412 } 1413 1414 for (off = 0; 1415 off < data[thr].unc_len; off += PAGE_SIZE) { 1416 memcpy(data_of(*snapshot), 1417 data[thr].unc + off, PAGE_SIZE); 1418 1419 if (!(nr_pages % m)) 1420 pr_info("Image loading progress: %3d%%\n", 1421 nr_pages / m * 10); 1422 nr_pages++; 1423 1424 ret = snapshot_write_next(snapshot); 1425 if (ret <= 0) { 1426 crc->run_threads = thr + 1; 1427 atomic_set(&crc->ready, 1); 1428 wake_up(&crc->go); 1429 goto out_finish; 1430 } 1431 } 1432 } 1433 1434 crc->run_threads = thr; 1435 atomic_set(&crc->ready, 1); 1436 wake_up(&crc->go); 1437 } 1438 1439 out_finish: 1440 if (crc->run_threads) { 1441 wait_event(crc->done, atomic_read(&crc->stop)); 1442 atomic_set(&crc->stop, 0); 1443 } 1444 stop = ktime_get(); 1445 if (!ret) { 1446 pr_info("Image loading done\n"); 1447 snapshot_write_finalize(snapshot); 1448 if (!snapshot_image_loaded(snapshot)) 1449 ret = -ENODATA; 1450 if (!ret) { 1451 if (swsusp_header->flags & SF_CRC32_MODE) { 1452 if(handle->crc32 != swsusp_header->crc32) { 1453 pr_err("Invalid image CRC32!\n"); 1454 ret = -ENODATA; 1455 } 1456 } 1457 } 1458 } 1459 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1460 out_clean: 1461 hib_finish_batch(&hb); 1462 for (i = 0; i < ring_size; i++) 1463 free_page((unsigned long)page[i]); 1464 if (crc) { 1465 if (crc->thr) 1466 kthread_stop(crc->thr); 1467 kfree(crc); 1468 } 1469 if (data) { 1470 for (thr = 0; thr < nr_threads; thr++) 1471 if (data[thr].thr) 1472 kthread_stop(data[thr].thr); 1473 vfree(data); 1474 } 1475 vfree(page); 1476 1477 return ret; 1478 } 1479 1480 /** 1481 * swsusp_read - read the hibernation image. 1482 * @flags_p: flags passed by the "frozen" kernel in the image header should 1483 * be written into this memory location 1484 */ 1485 1486 int swsusp_read(unsigned int *flags_p) 1487 { 1488 int error; 1489 struct swap_map_handle handle; 1490 struct snapshot_handle snapshot; 1491 struct swsusp_info *header; 1492 1493 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 1494 error = snapshot_write_next(&snapshot); 1495 if (error < (int)PAGE_SIZE) 1496 return error < 0 ? error : -EFAULT; 1497 header = (struct swsusp_info *)data_of(snapshot); 1498 error = get_swap_reader(&handle, flags_p); 1499 if (error) 1500 goto end; 1501 if (!error) 1502 error = swap_read_page(&handle, header, NULL); 1503 if (!error) { 1504 error = (*flags_p & SF_NOCOMPRESS_MODE) ? 1505 load_image(&handle, &snapshot, header->pages - 1) : 1506 load_image_lzo(&handle, &snapshot, header->pages - 1); 1507 } 1508 swap_reader_finish(&handle); 1509 end: 1510 if (!error) 1511 pr_debug("Image successfully loaded\n"); 1512 else 1513 pr_debug("Error %d resuming\n", error); 1514 return error; 1515 } 1516 1517 /** 1518 * swsusp_check - Check for swsusp signature in the resume device 1519 */ 1520 1521 int swsusp_check(void) 1522 { 1523 int error; 1524 void *holder; 1525 1526 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, 1527 FMODE_READ | FMODE_EXCL, &holder); 1528 if (!IS_ERR(hib_resume_bdev)) { 1529 set_blocksize(hib_resume_bdev, PAGE_SIZE); 1530 clear_page(swsusp_header); 1531 error = hib_submit_io(REQ_OP_READ, 0, 1532 swsusp_resume_block, 1533 swsusp_header, NULL); 1534 if (error) 1535 goto put; 1536 1537 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { 1538 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); 1539 /* Reset swap signature now */ 1540 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, 1541 swsusp_resume_block, 1542 swsusp_header, NULL); 1543 } else { 1544 error = -EINVAL; 1545 } 1546 if (!error && swsusp_header->flags & SF_HW_SIG && 1547 swsusp_header->hw_sig != swsusp_hardware_signature) { 1548 pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n", 1549 swsusp_header->hw_sig, swsusp_hardware_signature); 1550 error = -EINVAL; 1551 } 1552 1553 put: 1554 if (error) 1555 blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL); 1556 else 1557 pr_debug("Image signature found, resuming\n"); 1558 } else { 1559 error = PTR_ERR(hib_resume_bdev); 1560 } 1561 1562 if (error) 1563 pr_debug("Image not found (code %d)\n", error); 1564 1565 return error; 1566 } 1567 1568 /** 1569 * swsusp_close - close swap device. 1570 */ 1571 1572 void swsusp_close(fmode_t mode) 1573 { 1574 if (IS_ERR(hib_resume_bdev)) { 1575 pr_debug("Image device not initialised\n"); 1576 return; 1577 } 1578 1579 blkdev_put(hib_resume_bdev, mode); 1580 } 1581 1582 /** 1583 * swsusp_unmark - Unmark swsusp signature in the resume device 1584 */ 1585 1586 #ifdef CONFIG_SUSPEND 1587 int swsusp_unmark(void) 1588 { 1589 int error; 1590 1591 hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block, 1592 swsusp_header, NULL); 1593 if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) { 1594 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10); 1595 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC, 1596 swsusp_resume_block, 1597 swsusp_header, NULL); 1598 } else { 1599 pr_err("Cannot find swsusp signature!\n"); 1600 error = -ENODEV; 1601 } 1602 1603 /* 1604 * We just returned from suspend, we don't need the image any more. 1605 */ 1606 free_all_swap_pages(root_swap); 1607 1608 return error; 1609 } 1610 #endif 1611 1612 static int __init swsusp_header_init(void) 1613 { 1614 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); 1615 if (!swsusp_header) 1616 panic("Could not allocate memory for swsusp_header\n"); 1617 return 0; 1618 } 1619 1620 core_initcall(swsusp_header_init); 1621