1 /* 2 * linux/kernel/power/swap.c 3 * 4 * This file provides functions for reading the suspend image from 5 * and writing it to a swap partition. 6 * 7 * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz> 8 * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl> 9 * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com> 10 * 11 * This file is released under the GPLv2. 12 * 13 */ 14 15 #include <linux/module.h> 16 #include <linux/file.h> 17 #include <linux/delay.h> 18 #include <linux/bitops.h> 19 #include <linux/genhd.h> 20 #include <linux/device.h> 21 #include <linux/bio.h> 22 #include <linux/blkdev.h> 23 #include <linux/swap.h> 24 #include <linux/swapops.h> 25 #include <linux/pm.h> 26 #include <linux/slab.h> 27 #include <linux/lzo.h> 28 #include <linux/vmalloc.h> 29 #include <linux/cpumask.h> 30 #include <linux/atomic.h> 31 #include <linux/kthread.h> 32 #include <linux/crc32.h> 33 #include <linux/ktime.h> 34 35 #include "power.h" 36 37 #define HIBERNATE_SIG "S1SUSPEND" 38 39 /* 40 * When reading an {un,}compressed image, we may restore pages in place, 41 * in which case some architectures need these pages cleaning before they 42 * can be executed. We don't know which pages these may be, so clean the lot. 43 */ 44 static bool clean_pages_on_read; 45 static bool clean_pages_on_decompress; 46 47 /* 48 * The swap map is a data structure used for keeping track of each page 49 * written to a swap partition. It consists of many swap_map_page 50 * structures that contain each an array of MAP_PAGE_ENTRIES swap entries. 51 * These structures are stored on the swap and linked together with the 52 * help of the .next_swap member. 53 * 54 * The swap map is created during suspend. The swap map pages are 55 * allocated and populated one at a time, so we only need one memory 56 * page to set up the entire structure. 57 * 58 * During resume we pick up all swap_map_page structures into a list. 59 */ 60 61 #define MAP_PAGE_ENTRIES (PAGE_SIZE / sizeof(sector_t) - 1) 62 63 /* 64 * Number of free pages that are not high. 65 */ 66 static inline unsigned long low_free_pages(void) 67 { 68 return nr_free_pages() - nr_free_highpages(); 69 } 70 71 /* 72 * Number of pages required to be kept free while writing the image. Always 73 * half of all available low pages before the writing starts. 74 */ 75 static inline unsigned long reqd_free_pages(void) 76 { 77 return low_free_pages() / 2; 78 } 79 80 struct swap_map_page { 81 sector_t entries[MAP_PAGE_ENTRIES]; 82 sector_t next_swap; 83 }; 84 85 struct swap_map_page_list { 86 struct swap_map_page *map; 87 struct swap_map_page_list *next; 88 }; 89 90 /** 91 * The swap_map_handle structure is used for handling swap in 92 * a file-alike way 93 */ 94 95 struct swap_map_handle { 96 struct swap_map_page *cur; 97 struct swap_map_page_list *maps; 98 sector_t cur_swap; 99 sector_t first_sector; 100 unsigned int k; 101 unsigned long reqd_free_pages; 102 u32 crc32; 103 }; 104 105 struct swsusp_header { 106 char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) - 107 sizeof(u32)]; 108 u32 crc32; 109 sector_t image; 110 unsigned int flags; /* Flags to pass to the "boot" kernel */ 111 char orig_sig[10]; 112 char sig[10]; 113 } __packed; 114 115 static struct swsusp_header *swsusp_header; 116 117 /** 118 * The following functions are used for tracing the allocated 119 * swap pages, so that they can be freed in case of an error. 120 */ 121 122 struct swsusp_extent { 123 struct rb_node node; 124 unsigned long start; 125 unsigned long end; 126 }; 127 128 static struct rb_root swsusp_extents = RB_ROOT; 129 130 static int swsusp_extents_insert(unsigned long swap_offset) 131 { 132 struct rb_node **new = &(swsusp_extents.rb_node); 133 struct rb_node *parent = NULL; 134 struct swsusp_extent *ext; 135 136 /* Figure out where to put the new node */ 137 while (*new) { 138 ext = rb_entry(*new, struct swsusp_extent, node); 139 parent = *new; 140 if (swap_offset < ext->start) { 141 /* Try to merge */ 142 if (swap_offset == ext->start - 1) { 143 ext->start--; 144 return 0; 145 } 146 new = &((*new)->rb_left); 147 } else if (swap_offset > ext->end) { 148 /* Try to merge */ 149 if (swap_offset == ext->end + 1) { 150 ext->end++; 151 return 0; 152 } 153 new = &((*new)->rb_right); 154 } else { 155 /* It already is in the tree */ 156 return -EINVAL; 157 } 158 } 159 /* Add the new node and rebalance the tree. */ 160 ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL); 161 if (!ext) 162 return -ENOMEM; 163 164 ext->start = swap_offset; 165 ext->end = swap_offset; 166 rb_link_node(&ext->node, parent, new); 167 rb_insert_color(&ext->node, &swsusp_extents); 168 return 0; 169 } 170 171 /** 172 * alloc_swapdev_block - allocate a swap page and register that it has 173 * been allocated, so that it can be freed in case of an error. 174 */ 175 176 sector_t alloc_swapdev_block(int swap) 177 { 178 unsigned long offset; 179 180 offset = swp_offset(get_swap_page_of_type(swap)); 181 if (offset) { 182 if (swsusp_extents_insert(offset)) 183 swap_free(swp_entry(swap, offset)); 184 else 185 return swapdev_block(swap, offset); 186 } 187 return 0; 188 } 189 190 /** 191 * free_all_swap_pages - free swap pages allocated for saving image data. 192 * It also frees the extents used to register which swap entries had been 193 * allocated. 194 */ 195 196 void free_all_swap_pages(int swap) 197 { 198 struct rb_node *node; 199 200 while ((node = swsusp_extents.rb_node)) { 201 struct swsusp_extent *ext; 202 unsigned long offset; 203 204 ext = container_of(node, struct swsusp_extent, node); 205 rb_erase(node, &swsusp_extents); 206 for (offset = ext->start; offset <= ext->end; offset++) 207 swap_free(swp_entry(swap, offset)); 208 209 kfree(ext); 210 } 211 } 212 213 int swsusp_swap_in_use(void) 214 { 215 return (swsusp_extents.rb_node != NULL); 216 } 217 218 /* 219 * General things 220 */ 221 222 static unsigned short root_swap = 0xffff; 223 static struct block_device *hib_resume_bdev; 224 225 struct hib_bio_batch { 226 atomic_t count; 227 wait_queue_head_t wait; 228 int error; 229 }; 230 231 static void hib_init_batch(struct hib_bio_batch *hb) 232 { 233 atomic_set(&hb->count, 0); 234 init_waitqueue_head(&hb->wait); 235 hb->error = 0; 236 } 237 238 static void hib_end_io(struct bio *bio) 239 { 240 struct hib_bio_batch *hb = bio->bi_private; 241 struct page *page = bio->bi_io_vec[0].bv_page; 242 243 if (bio->bi_error) { 244 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n", 245 imajor(bio->bi_bdev->bd_inode), 246 iminor(bio->bi_bdev->bd_inode), 247 (unsigned long long)bio->bi_iter.bi_sector); 248 } 249 250 if (bio_data_dir(bio) == WRITE) 251 put_page(page); 252 else if (clean_pages_on_read) 253 flush_icache_range((unsigned long)page_address(page), 254 (unsigned long)page_address(page) + PAGE_SIZE); 255 256 if (bio->bi_error && !hb->error) 257 hb->error = bio->bi_error; 258 if (atomic_dec_and_test(&hb->count)) 259 wake_up(&hb->wait); 260 261 bio_put(bio); 262 } 263 264 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr, 265 struct hib_bio_batch *hb) 266 { 267 struct page *page = virt_to_page(addr); 268 struct bio *bio; 269 int error = 0; 270 271 bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1); 272 bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9); 273 bio->bi_bdev = hib_resume_bdev; 274 bio_set_op_attrs(bio, op, op_flags); 275 276 if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) { 277 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n", 278 (unsigned long long)bio->bi_iter.bi_sector); 279 bio_put(bio); 280 return -EFAULT; 281 } 282 283 if (hb) { 284 bio->bi_end_io = hib_end_io; 285 bio->bi_private = hb; 286 atomic_inc(&hb->count); 287 submit_bio(bio); 288 } else { 289 error = submit_bio_wait(bio); 290 bio_put(bio); 291 } 292 293 return error; 294 } 295 296 static int hib_wait_io(struct hib_bio_batch *hb) 297 { 298 wait_event(hb->wait, atomic_read(&hb->count) == 0); 299 return hb->error; 300 } 301 302 /* 303 * Saving part 304 */ 305 306 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags) 307 { 308 int error; 309 310 hib_submit_io(REQ_OP_READ, READ_SYNC, swsusp_resume_block, 311 swsusp_header, NULL); 312 if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) || 313 !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) { 314 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10); 315 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10); 316 swsusp_header->image = handle->first_sector; 317 swsusp_header->flags = flags; 318 if (flags & SF_CRC32_MODE) 319 swsusp_header->crc32 = handle->crc32; 320 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC, 321 swsusp_resume_block, swsusp_header, NULL); 322 } else { 323 printk(KERN_ERR "PM: Swap header not found!\n"); 324 error = -ENODEV; 325 } 326 return error; 327 } 328 329 /** 330 * swsusp_swap_check - check if the resume device is a swap device 331 * and get its index (if so) 332 * 333 * This is called before saving image 334 */ 335 static int swsusp_swap_check(void) 336 { 337 int res; 338 339 res = swap_type_of(swsusp_resume_device, swsusp_resume_block, 340 &hib_resume_bdev); 341 if (res < 0) 342 return res; 343 344 root_swap = res; 345 res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL); 346 if (res) 347 return res; 348 349 res = set_blocksize(hib_resume_bdev, PAGE_SIZE); 350 if (res < 0) 351 blkdev_put(hib_resume_bdev, FMODE_WRITE); 352 353 /* 354 * Update the resume device to the one actually used, 355 * so the test_resume mode can use it in case it is 356 * invoked from hibernate() to test the snapshot. 357 */ 358 swsusp_resume_device = hib_resume_bdev->bd_dev; 359 return res; 360 } 361 362 /** 363 * write_page - Write one page to given swap location. 364 * @buf: Address we're writing. 365 * @offset: Offset of the swap page we're writing to. 366 * @hb: bio completion batch 367 */ 368 369 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb) 370 { 371 void *src; 372 int ret; 373 374 if (!offset) 375 return -ENOSPC; 376 377 if (hb) { 378 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN | 379 __GFP_NORETRY); 380 if (src) { 381 copy_page(src, buf); 382 } else { 383 ret = hib_wait_io(hb); /* Free pages */ 384 if (ret) 385 return ret; 386 src = (void *)__get_free_page(__GFP_RECLAIM | 387 __GFP_NOWARN | 388 __GFP_NORETRY); 389 if (src) { 390 copy_page(src, buf); 391 } else { 392 WARN_ON_ONCE(1); 393 hb = NULL; /* Go synchronous */ 394 src = buf; 395 } 396 } 397 } else { 398 src = buf; 399 } 400 return hib_submit_io(REQ_OP_WRITE, WRITE_SYNC, offset, src, hb); 401 } 402 403 static void release_swap_writer(struct swap_map_handle *handle) 404 { 405 if (handle->cur) 406 free_page((unsigned long)handle->cur); 407 handle->cur = NULL; 408 } 409 410 static int get_swap_writer(struct swap_map_handle *handle) 411 { 412 int ret; 413 414 ret = swsusp_swap_check(); 415 if (ret) { 416 if (ret != -ENOSPC) 417 printk(KERN_ERR "PM: Cannot find swap device, try " 418 "swapon -a.\n"); 419 return ret; 420 } 421 handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL); 422 if (!handle->cur) { 423 ret = -ENOMEM; 424 goto err_close; 425 } 426 handle->cur_swap = alloc_swapdev_block(root_swap); 427 if (!handle->cur_swap) { 428 ret = -ENOSPC; 429 goto err_rel; 430 } 431 handle->k = 0; 432 handle->reqd_free_pages = reqd_free_pages(); 433 handle->first_sector = handle->cur_swap; 434 return 0; 435 err_rel: 436 release_swap_writer(handle); 437 err_close: 438 swsusp_close(FMODE_WRITE); 439 return ret; 440 } 441 442 static int swap_write_page(struct swap_map_handle *handle, void *buf, 443 struct hib_bio_batch *hb) 444 { 445 int error = 0; 446 sector_t offset; 447 448 if (!handle->cur) 449 return -EINVAL; 450 offset = alloc_swapdev_block(root_swap); 451 error = write_page(buf, offset, hb); 452 if (error) 453 return error; 454 handle->cur->entries[handle->k++] = offset; 455 if (handle->k >= MAP_PAGE_ENTRIES) { 456 offset = alloc_swapdev_block(root_swap); 457 if (!offset) 458 return -ENOSPC; 459 handle->cur->next_swap = offset; 460 error = write_page(handle->cur, handle->cur_swap, hb); 461 if (error) 462 goto out; 463 clear_page(handle->cur); 464 handle->cur_swap = offset; 465 handle->k = 0; 466 467 if (hb && low_free_pages() <= handle->reqd_free_pages) { 468 error = hib_wait_io(hb); 469 if (error) 470 goto out; 471 /* 472 * Recalculate the number of required free pages, to 473 * make sure we never take more than half. 474 */ 475 handle->reqd_free_pages = reqd_free_pages(); 476 } 477 } 478 out: 479 return error; 480 } 481 482 static int flush_swap_writer(struct swap_map_handle *handle) 483 { 484 if (handle->cur && handle->cur_swap) 485 return write_page(handle->cur, handle->cur_swap, NULL); 486 else 487 return -EINVAL; 488 } 489 490 static int swap_writer_finish(struct swap_map_handle *handle, 491 unsigned int flags, int error) 492 { 493 if (!error) { 494 flush_swap_writer(handle); 495 printk(KERN_INFO "PM: S"); 496 error = mark_swapfiles(handle, flags); 497 printk("|\n"); 498 } 499 500 if (error) 501 free_all_swap_pages(root_swap); 502 release_swap_writer(handle); 503 swsusp_close(FMODE_WRITE); 504 505 return error; 506 } 507 508 /* We need to remember how much compressed data we need to read. */ 509 #define LZO_HEADER sizeof(size_t) 510 511 /* Number of pages/bytes we'll compress at one time. */ 512 #define LZO_UNC_PAGES 32 513 #define LZO_UNC_SIZE (LZO_UNC_PAGES * PAGE_SIZE) 514 515 /* Number of pages/bytes we need for compressed data (worst case). */ 516 #define LZO_CMP_PAGES DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \ 517 LZO_HEADER, PAGE_SIZE) 518 #define LZO_CMP_SIZE (LZO_CMP_PAGES * PAGE_SIZE) 519 520 /* Maximum number of threads for compression/decompression. */ 521 #define LZO_THREADS 3 522 523 /* Minimum/maximum number of pages for read buffering. */ 524 #define LZO_MIN_RD_PAGES 1024 525 #define LZO_MAX_RD_PAGES 8192 526 527 528 /** 529 * save_image - save the suspend image data 530 */ 531 532 static int save_image(struct swap_map_handle *handle, 533 struct snapshot_handle *snapshot, 534 unsigned int nr_to_write) 535 { 536 unsigned int m; 537 int ret; 538 int nr_pages; 539 int err2; 540 struct hib_bio_batch hb; 541 ktime_t start; 542 ktime_t stop; 543 544 hib_init_batch(&hb); 545 546 printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n", 547 nr_to_write); 548 m = nr_to_write / 10; 549 if (!m) 550 m = 1; 551 nr_pages = 0; 552 start = ktime_get(); 553 while (1) { 554 ret = snapshot_read_next(snapshot); 555 if (ret <= 0) 556 break; 557 ret = swap_write_page(handle, data_of(*snapshot), &hb); 558 if (ret) 559 break; 560 if (!(nr_pages % m)) 561 printk(KERN_INFO "PM: Image saving progress: %3d%%\n", 562 nr_pages / m * 10); 563 nr_pages++; 564 } 565 err2 = hib_wait_io(&hb); 566 stop = ktime_get(); 567 if (!ret) 568 ret = err2; 569 if (!ret) 570 printk(KERN_INFO "PM: Image saving done.\n"); 571 swsusp_show_speed(start, stop, nr_to_write, "Wrote"); 572 return ret; 573 } 574 575 /** 576 * Structure used for CRC32. 577 */ 578 struct crc_data { 579 struct task_struct *thr; /* thread */ 580 atomic_t ready; /* ready to start flag */ 581 atomic_t stop; /* ready to stop flag */ 582 unsigned run_threads; /* nr current threads */ 583 wait_queue_head_t go; /* start crc update */ 584 wait_queue_head_t done; /* crc update done */ 585 u32 *crc32; /* points to handle's crc32 */ 586 size_t *unc_len[LZO_THREADS]; /* uncompressed lengths */ 587 unsigned char *unc[LZO_THREADS]; /* uncompressed data */ 588 }; 589 590 /** 591 * CRC32 update function that runs in its own thread. 592 */ 593 static int crc32_threadfn(void *data) 594 { 595 struct crc_data *d = data; 596 unsigned i; 597 598 while (1) { 599 wait_event(d->go, atomic_read(&d->ready) || 600 kthread_should_stop()); 601 if (kthread_should_stop()) { 602 d->thr = NULL; 603 atomic_set(&d->stop, 1); 604 wake_up(&d->done); 605 break; 606 } 607 atomic_set(&d->ready, 0); 608 609 for (i = 0; i < d->run_threads; i++) 610 *d->crc32 = crc32_le(*d->crc32, 611 d->unc[i], *d->unc_len[i]); 612 atomic_set(&d->stop, 1); 613 wake_up(&d->done); 614 } 615 return 0; 616 } 617 /** 618 * Structure used for LZO data compression. 619 */ 620 struct cmp_data { 621 struct task_struct *thr; /* thread */ 622 atomic_t ready; /* ready to start flag */ 623 atomic_t stop; /* ready to stop flag */ 624 int ret; /* return code */ 625 wait_queue_head_t go; /* start compression */ 626 wait_queue_head_t done; /* compression done */ 627 size_t unc_len; /* uncompressed length */ 628 size_t cmp_len; /* compressed length */ 629 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 630 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 631 unsigned char wrk[LZO1X_1_MEM_COMPRESS]; /* compression workspace */ 632 }; 633 634 /** 635 * Compression function that runs in its own thread. 636 */ 637 static int lzo_compress_threadfn(void *data) 638 { 639 struct cmp_data *d = data; 640 641 while (1) { 642 wait_event(d->go, atomic_read(&d->ready) || 643 kthread_should_stop()); 644 if (kthread_should_stop()) { 645 d->thr = NULL; 646 d->ret = -1; 647 atomic_set(&d->stop, 1); 648 wake_up(&d->done); 649 break; 650 } 651 atomic_set(&d->ready, 0); 652 653 d->ret = lzo1x_1_compress(d->unc, d->unc_len, 654 d->cmp + LZO_HEADER, &d->cmp_len, 655 d->wrk); 656 atomic_set(&d->stop, 1); 657 wake_up(&d->done); 658 } 659 return 0; 660 } 661 662 /** 663 * save_image_lzo - Save the suspend image data compressed with LZO. 664 * @handle: Swap map handle to use for saving the image. 665 * @snapshot: Image to read data from. 666 * @nr_to_write: Number of pages to save. 667 */ 668 static int save_image_lzo(struct swap_map_handle *handle, 669 struct snapshot_handle *snapshot, 670 unsigned int nr_to_write) 671 { 672 unsigned int m; 673 int ret = 0; 674 int nr_pages; 675 int err2; 676 struct hib_bio_batch hb; 677 ktime_t start; 678 ktime_t stop; 679 size_t off; 680 unsigned thr, run_threads, nr_threads; 681 unsigned char *page = NULL; 682 struct cmp_data *data = NULL; 683 struct crc_data *crc = NULL; 684 685 hib_init_batch(&hb); 686 687 /* 688 * We'll limit the number of threads for compression to limit memory 689 * footprint. 690 */ 691 nr_threads = num_online_cpus() - 1; 692 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 693 694 page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH); 695 if (!page) { 696 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 697 ret = -ENOMEM; 698 goto out_clean; 699 } 700 701 data = vmalloc(sizeof(*data) * nr_threads); 702 if (!data) { 703 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 704 ret = -ENOMEM; 705 goto out_clean; 706 } 707 for (thr = 0; thr < nr_threads; thr++) 708 memset(&data[thr], 0, offsetof(struct cmp_data, go)); 709 710 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 711 if (!crc) { 712 printk(KERN_ERR "PM: Failed to allocate crc\n"); 713 ret = -ENOMEM; 714 goto out_clean; 715 } 716 memset(crc, 0, offsetof(struct crc_data, go)); 717 718 /* 719 * Start the compression threads. 720 */ 721 for (thr = 0; thr < nr_threads; thr++) { 722 init_waitqueue_head(&data[thr].go); 723 init_waitqueue_head(&data[thr].done); 724 725 data[thr].thr = kthread_run(lzo_compress_threadfn, 726 &data[thr], 727 "image_compress/%u", thr); 728 if (IS_ERR(data[thr].thr)) { 729 data[thr].thr = NULL; 730 printk(KERN_ERR 731 "PM: Cannot start compression threads\n"); 732 ret = -ENOMEM; 733 goto out_clean; 734 } 735 } 736 737 /* 738 * Start the CRC32 thread. 739 */ 740 init_waitqueue_head(&crc->go); 741 init_waitqueue_head(&crc->done); 742 743 handle->crc32 = 0; 744 crc->crc32 = &handle->crc32; 745 for (thr = 0; thr < nr_threads; thr++) { 746 crc->unc[thr] = data[thr].unc; 747 crc->unc_len[thr] = &data[thr].unc_len; 748 } 749 750 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 751 if (IS_ERR(crc->thr)) { 752 crc->thr = NULL; 753 printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); 754 ret = -ENOMEM; 755 goto out_clean; 756 } 757 758 /* 759 * Adjust the number of required free pages after all allocations have 760 * been done. We don't want to run out of pages when writing. 761 */ 762 handle->reqd_free_pages = reqd_free_pages(); 763 764 printk(KERN_INFO 765 "PM: Using %u thread(s) for compression.\n" 766 "PM: Compressing and saving image data (%u pages)...\n", 767 nr_threads, nr_to_write); 768 m = nr_to_write / 10; 769 if (!m) 770 m = 1; 771 nr_pages = 0; 772 start = ktime_get(); 773 for (;;) { 774 for (thr = 0; thr < nr_threads; thr++) { 775 for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) { 776 ret = snapshot_read_next(snapshot); 777 if (ret < 0) 778 goto out_finish; 779 780 if (!ret) 781 break; 782 783 memcpy(data[thr].unc + off, 784 data_of(*snapshot), PAGE_SIZE); 785 786 if (!(nr_pages % m)) 787 printk(KERN_INFO 788 "PM: Image saving progress: " 789 "%3d%%\n", 790 nr_pages / m * 10); 791 nr_pages++; 792 } 793 if (!off) 794 break; 795 796 data[thr].unc_len = off; 797 798 atomic_set(&data[thr].ready, 1); 799 wake_up(&data[thr].go); 800 } 801 802 if (!thr) 803 break; 804 805 crc->run_threads = thr; 806 atomic_set(&crc->ready, 1); 807 wake_up(&crc->go); 808 809 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 810 wait_event(data[thr].done, 811 atomic_read(&data[thr].stop)); 812 atomic_set(&data[thr].stop, 0); 813 814 ret = data[thr].ret; 815 816 if (ret < 0) { 817 printk(KERN_ERR "PM: LZO compression failed\n"); 818 goto out_finish; 819 } 820 821 if (unlikely(!data[thr].cmp_len || 822 data[thr].cmp_len > 823 lzo1x_worst_compress(data[thr].unc_len))) { 824 printk(KERN_ERR 825 "PM: Invalid LZO compressed length\n"); 826 ret = -1; 827 goto out_finish; 828 } 829 830 *(size_t *)data[thr].cmp = data[thr].cmp_len; 831 832 /* 833 * Given we are writing one page at a time to disk, we 834 * copy that much from the buffer, although the last 835 * bit will likely be smaller than full page. This is 836 * OK - we saved the length of the compressed data, so 837 * any garbage at the end will be discarded when we 838 * read it. 839 */ 840 for (off = 0; 841 off < LZO_HEADER + data[thr].cmp_len; 842 off += PAGE_SIZE) { 843 memcpy(page, data[thr].cmp + off, PAGE_SIZE); 844 845 ret = swap_write_page(handle, page, &hb); 846 if (ret) 847 goto out_finish; 848 } 849 } 850 851 wait_event(crc->done, atomic_read(&crc->stop)); 852 atomic_set(&crc->stop, 0); 853 } 854 855 out_finish: 856 err2 = hib_wait_io(&hb); 857 stop = ktime_get(); 858 if (!ret) 859 ret = err2; 860 if (!ret) 861 printk(KERN_INFO "PM: Image saving done.\n"); 862 swsusp_show_speed(start, stop, nr_to_write, "Wrote"); 863 out_clean: 864 if (crc) { 865 if (crc->thr) 866 kthread_stop(crc->thr); 867 kfree(crc); 868 } 869 if (data) { 870 for (thr = 0; thr < nr_threads; thr++) 871 if (data[thr].thr) 872 kthread_stop(data[thr].thr); 873 vfree(data); 874 } 875 if (page) free_page((unsigned long)page); 876 877 return ret; 878 } 879 880 /** 881 * enough_swap - Make sure we have enough swap to save the image. 882 * 883 * Returns TRUE or FALSE after checking the total amount of swap 884 * space avaiable from the resume partition. 885 */ 886 887 static int enough_swap(unsigned int nr_pages, unsigned int flags) 888 { 889 unsigned int free_swap = count_swap_pages(root_swap, 1); 890 unsigned int required; 891 892 pr_debug("PM: Free swap pages: %u\n", free_swap); 893 894 required = PAGES_FOR_IO + nr_pages; 895 return free_swap > required; 896 } 897 898 /** 899 * swsusp_write - Write entire image and metadata. 900 * @flags: flags to pass to the "boot" kernel in the image header 901 * 902 * It is important _NOT_ to umount filesystems at this point. We want 903 * them synced (in case something goes wrong) but we DO not want to mark 904 * filesystem clean: it is not. (And it does not matter, if we resume 905 * correctly, we'll mark system clean, anyway.) 906 */ 907 908 int swsusp_write(unsigned int flags) 909 { 910 struct swap_map_handle handle; 911 struct snapshot_handle snapshot; 912 struct swsusp_info *header; 913 unsigned long pages; 914 int error; 915 916 pages = snapshot_get_image_size(); 917 error = get_swap_writer(&handle); 918 if (error) { 919 printk(KERN_ERR "PM: Cannot get swap writer\n"); 920 return error; 921 } 922 if (flags & SF_NOCOMPRESS_MODE) { 923 if (!enough_swap(pages, flags)) { 924 printk(KERN_ERR "PM: Not enough free swap\n"); 925 error = -ENOSPC; 926 goto out_finish; 927 } 928 } 929 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 930 error = snapshot_read_next(&snapshot); 931 if (error < PAGE_SIZE) { 932 if (error >= 0) 933 error = -EFAULT; 934 935 goto out_finish; 936 } 937 header = (struct swsusp_info *)data_of(snapshot); 938 error = swap_write_page(&handle, header, NULL); 939 if (!error) { 940 error = (flags & SF_NOCOMPRESS_MODE) ? 941 save_image(&handle, &snapshot, pages - 1) : 942 save_image_lzo(&handle, &snapshot, pages - 1); 943 } 944 out_finish: 945 error = swap_writer_finish(&handle, flags, error); 946 return error; 947 } 948 949 /** 950 * The following functions allow us to read data using a swap map 951 * in a file-alike way 952 */ 953 954 static void release_swap_reader(struct swap_map_handle *handle) 955 { 956 struct swap_map_page_list *tmp; 957 958 while (handle->maps) { 959 if (handle->maps->map) 960 free_page((unsigned long)handle->maps->map); 961 tmp = handle->maps; 962 handle->maps = handle->maps->next; 963 kfree(tmp); 964 } 965 handle->cur = NULL; 966 } 967 968 static int get_swap_reader(struct swap_map_handle *handle, 969 unsigned int *flags_p) 970 { 971 int error; 972 struct swap_map_page_list *tmp, *last; 973 sector_t offset; 974 975 *flags_p = swsusp_header->flags; 976 977 if (!swsusp_header->image) /* how can this happen? */ 978 return -EINVAL; 979 980 handle->cur = NULL; 981 last = handle->maps = NULL; 982 offset = swsusp_header->image; 983 while (offset) { 984 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL); 985 if (!tmp) { 986 release_swap_reader(handle); 987 return -ENOMEM; 988 } 989 memset(tmp, 0, sizeof(*tmp)); 990 if (!handle->maps) 991 handle->maps = tmp; 992 if (last) 993 last->next = tmp; 994 last = tmp; 995 996 tmp->map = (struct swap_map_page *) 997 __get_free_page(__GFP_RECLAIM | __GFP_HIGH); 998 if (!tmp->map) { 999 release_swap_reader(handle); 1000 return -ENOMEM; 1001 } 1002 1003 error = hib_submit_io(REQ_OP_READ, READ_SYNC, offset, 1004 tmp->map, NULL); 1005 if (error) { 1006 release_swap_reader(handle); 1007 return error; 1008 } 1009 offset = tmp->map->next_swap; 1010 } 1011 handle->k = 0; 1012 handle->cur = handle->maps->map; 1013 return 0; 1014 } 1015 1016 static int swap_read_page(struct swap_map_handle *handle, void *buf, 1017 struct hib_bio_batch *hb) 1018 { 1019 sector_t offset; 1020 int error; 1021 struct swap_map_page_list *tmp; 1022 1023 if (!handle->cur) 1024 return -EINVAL; 1025 offset = handle->cur->entries[handle->k]; 1026 if (!offset) 1027 return -EFAULT; 1028 error = hib_submit_io(REQ_OP_READ, READ_SYNC, offset, buf, hb); 1029 if (error) 1030 return error; 1031 if (++handle->k >= MAP_PAGE_ENTRIES) { 1032 handle->k = 0; 1033 free_page((unsigned long)handle->maps->map); 1034 tmp = handle->maps; 1035 handle->maps = handle->maps->next; 1036 kfree(tmp); 1037 if (!handle->maps) 1038 release_swap_reader(handle); 1039 else 1040 handle->cur = handle->maps->map; 1041 } 1042 return error; 1043 } 1044 1045 static int swap_reader_finish(struct swap_map_handle *handle) 1046 { 1047 release_swap_reader(handle); 1048 1049 return 0; 1050 } 1051 1052 /** 1053 * load_image - load the image using the swap map handle 1054 * @handle and the snapshot handle @snapshot 1055 * (assume there are @nr_pages pages to load) 1056 */ 1057 1058 static int load_image(struct swap_map_handle *handle, 1059 struct snapshot_handle *snapshot, 1060 unsigned int nr_to_read) 1061 { 1062 unsigned int m; 1063 int ret = 0; 1064 ktime_t start; 1065 ktime_t stop; 1066 struct hib_bio_batch hb; 1067 int err2; 1068 unsigned nr_pages; 1069 1070 hib_init_batch(&hb); 1071 1072 clean_pages_on_read = true; 1073 printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n", 1074 nr_to_read); 1075 m = nr_to_read / 10; 1076 if (!m) 1077 m = 1; 1078 nr_pages = 0; 1079 start = ktime_get(); 1080 for ( ; ; ) { 1081 ret = snapshot_write_next(snapshot); 1082 if (ret <= 0) 1083 break; 1084 ret = swap_read_page(handle, data_of(*snapshot), &hb); 1085 if (ret) 1086 break; 1087 if (snapshot->sync_read) 1088 ret = hib_wait_io(&hb); 1089 if (ret) 1090 break; 1091 if (!(nr_pages % m)) 1092 printk(KERN_INFO "PM: Image loading progress: %3d%%\n", 1093 nr_pages / m * 10); 1094 nr_pages++; 1095 } 1096 err2 = hib_wait_io(&hb); 1097 stop = ktime_get(); 1098 if (!ret) 1099 ret = err2; 1100 if (!ret) { 1101 printk(KERN_INFO "PM: Image loading done.\n"); 1102 snapshot_write_finalize(snapshot); 1103 if (!snapshot_image_loaded(snapshot)) 1104 ret = -ENODATA; 1105 } 1106 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1107 return ret; 1108 } 1109 1110 /** 1111 * Structure used for LZO data decompression. 1112 */ 1113 struct dec_data { 1114 struct task_struct *thr; /* thread */ 1115 atomic_t ready; /* ready to start flag */ 1116 atomic_t stop; /* ready to stop flag */ 1117 int ret; /* return code */ 1118 wait_queue_head_t go; /* start decompression */ 1119 wait_queue_head_t done; /* decompression done */ 1120 size_t unc_len; /* uncompressed length */ 1121 size_t cmp_len; /* compressed length */ 1122 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 1123 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 1124 }; 1125 1126 /** 1127 * Deompression function that runs in its own thread. 1128 */ 1129 static int lzo_decompress_threadfn(void *data) 1130 { 1131 struct dec_data *d = data; 1132 1133 while (1) { 1134 wait_event(d->go, atomic_read(&d->ready) || 1135 kthread_should_stop()); 1136 if (kthread_should_stop()) { 1137 d->thr = NULL; 1138 d->ret = -1; 1139 atomic_set(&d->stop, 1); 1140 wake_up(&d->done); 1141 break; 1142 } 1143 atomic_set(&d->ready, 0); 1144 1145 d->unc_len = LZO_UNC_SIZE; 1146 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, 1147 d->unc, &d->unc_len); 1148 if (clean_pages_on_decompress) 1149 flush_icache_range((unsigned long)d->unc, 1150 (unsigned long)d->unc + d->unc_len); 1151 1152 atomic_set(&d->stop, 1); 1153 wake_up(&d->done); 1154 } 1155 return 0; 1156 } 1157 1158 /** 1159 * load_image_lzo - Load compressed image data and decompress them with LZO. 1160 * @handle: Swap map handle to use for loading data. 1161 * @snapshot: Image to copy uncompressed data into. 1162 * @nr_to_read: Number of pages to load. 1163 */ 1164 static int load_image_lzo(struct swap_map_handle *handle, 1165 struct snapshot_handle *snapshot, 1166 unsigned int nr_to_read) 1167 { 1168 unsigned int m; 1169 int ret = 0; 1170 int eof = 0; 1171 struct hib_bio_batch hb; 1172 ktime_t start; 1173 ktime_t stop; 1174 unsigned nr_pages; 1175 size_t off; 1176 unsigned i, thr, run_threads, nr_threads; 1177 unsigned ring = 0, pg = 0, ring_size = 0, 1178 have = 0, want, need, asked = 0; 1179 unsigned long read_pages = 0; 1180 unsigned char **page = NULL; 1181 struct dec_data *data = NULL; 1182 struct crc_data *crc = NULL; 1183 1184 hib_init_batch(&hb); 1185 1186 /* 1187 * We'll limit the number of threads for decompression to limit memory 1188 * footprint. 1189 */ 1190 nr_threads = num_online_cpus() - 1; 1191 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 1192 1193 page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES); 1194 if (!page) { 1195 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 1196 ret = -ENOMEM; 1197 goto out_clean; 1198 } 1199 1200 data = vmalloc(sizeof(*data) * nr_threads); 1201 if (!data) { 1202 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 1203 ret = -ENOMEM; 1204 goto out_clean; 1205 } 1206 for (thr = 0; thr < nr_threads; thr++) 1207 memset(&data[thr], 0, offsetof(struct dec_data, go)); 1208 1209 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 1210 if (!crc) { 1211 printk(KERN_ERR "PM: Failed to allocate crc\n"); 1212 ret = -ENOMEM; 1213 goto out_clean; 1214 } 1215 memset(crc, 0, offsetof(struct crc_data, go)); 1216 1217 clean_pages_on_decompress = true; 1218 1219 /* 1220 * Start the decompression threads. 1221 */ 1222 for (thr = 0; thr < nr_threads; thr++) { 1223 init_waitqueue_head(&data[thr].go); 1224 init_waitqueue_head(&data[thr].done); 1225 1226 data[thr].thr = kthread_run(lzo_decompress_threadfn, 1227 &data[thr], 1228 "image_decompress/%u", thr); 1229 if (IS_ERR(data[thr].thr)) { 1230 data[thr].thr = NULL; 1231 printk(KERN_ERR 1232 "PM: 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 printk(KERN_ERR "PM: 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_RECLAIM | __GFP_HIGH : 1273 __GFP_RECLAIM | __GFP_NOWARN | 1274 __GFP_NORETRY); 1275 1276 if (!page[i]) { 1277 if (i < LZO_CMP_PAGES) { 1278 ring_size = i; 1279 printk(KERN_ERR 1280 "PM: Failed to allocate LZO pages\n"); 1281 ret = -ENOMEM; 1282 goto out_clean; 1283 } else { 1284 break; 1285 } 1286 } 1287 } 1288 want = ring_size = i; 1289 1290 printk(KERN_INFO 1291 "PM: Using %u thread(s) for decompression.\n" 1292 "PM: Loading and decompressing image data (%u pages)...\n", 1293 nr_threads, nr_to_read); 1294 m = nr_to_read / 10; 1295 if (!m) 1296 m = 1; 1297 nr_pages = 0; 1298 start = ktime_get(); 1299 1300 ret = snapshot_write_next(snapshot); 1301 if (ret <= 0) 1302 goto out_finish; 1303 1304 for(;;) { 1305 for (i = 0; !eof && i < want; i++) { 1306 ret = swap_read_page(handle, page[ring], &hb); 1307 if (ret) { 1308 /* 1309 * On real read error, finish. On end of data, 1310 * set EOF flag and just exit the read loop. 1311 */ 1312 if (handle->cur && 1313 handle->cur->entries[handle->k]) { 1314 goto out_finish; 1315 } else { 1316 eof = 1; 1317 break; 1318 } 1319 } 1320 if (++ring >= ring_size) 1321 ring = 0; 1322 } 1323 asked += i; 1324 want -= i; 1325 1326 /* 1327 * We are out of data, wait for some more. 1328 */ 1329 if (!have) { 1330 if (!asked) 1331 break; 1332 1333 ret = hib_wait_io(&hb); 1334 if (ret) 1335 goto out_finish; 1336 have += asked; 1337 asked = 0; 1338 if (eof) 1339 eof = 2; 1340 } 1341 1342 if (crc->run_threads) { 1343 wait_event(crc->done, atomic_read(&crc->stop)); 1344 atomic_set(&crc->stop, 0); 1345 crc->run_threads = 0; 1346 } 1347 1348 for (thr = 0; have && thr < nr_threads; thr++) { 1349 data[thr].cmp_len = *(size_t *)page[pg]; 1350 if (unlikely(!data[thr].cmp_len || 1351 data[thr].cmp_len > 1352 lzo1x_worst_compress(LZO_UNC_SIZE))) { 1353 printk(KERN_ERR 1354 "PM: Invalid LZO compressed length\n"); 1355 ret = -1; 1356 goto out_finish; 1357 } 1358 1359 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, 1360 PAGE_SIZE); 1361 if (need > have) { 1362 if (eof > 1) { 1363 ret = -1; 1364 goto out_finish; 1365 } 1366 break; 1367 } 1368 1369 for (off = 0; 1370 off < LZO_HEADER + data[thr].cmp_len; 1371 off += PAGE_SIZE) { 1372 memcpy(data[thr].cmp + off, 1373 page[pg], PAGE_SIZE); 1374 have--; 1375 want++; 1376 if (++pg >= ring_size) 1377 pg = 0; 1378 } 1379 1380 atomic_set(&data[thr].ready, 1); 1381 wake_up(&data[thr].go); 1382 } 1383 1384 /* 1385 * Wait for more data while we are decompressing. 1386 */ 1387 if (have < LZO_CMP_PAGES && asked) { 1388 ret = hib_wait_io(&hb); 1389 if (ret) 1390 goto out_finish; 1391 have += asked; 1392 asked = 0; 1393 if (eof) 1394 eof = 2; 1395 } 1396 1397 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 1398 wait_event(data[thr].done, 1399 atomic_read(&data[thr].stop)); 1400 atomic_set(&data[thr].stop, 0); 1401 1402 ret = data[thr].ret; 1403 1404 if (ret < 0) { 1405 printk(KERN_ERR 1406 "PM: LZO decompression failed\n"); 1407 goto out_finish; 1408 } 1409 1410 if (unlikely(!data[thr].unc_len || 1411 data[thr].unc_len > LZO_UNC_SIZE || 1412 data[thr].unc_len & (PAGE_SIZE - 1))) { 1413 printk(KERN_ERR 1414 "PM: Invalid LZO uncompressed length\n"); 1415 ret = -1; 1416 goto out_finish; 1417 } 1418 1419 for (off = 0; 1420 off < data[thr].unc_len; off += PAGE_SIZE) { 1421 memcpy(data_of(*snapshot), 1422 data[thr].unc + off, PAGE_SIZE); 1423 1424 if (!(nr_pages % m)) 1425 printk(KERN_INFO 1426 "PM: Image loading progress: " 1427 "%3d%%\n", 1428 nr_pages / m * 10); 1429 nr_pages++; 1430 1431 ret = snapshot_write_next(snapshot); 1432 if (ret <= 0) { 1433 crc->run_threads = thr + 1; 1434 atomic_set(&crc->ready, 1); 1435 wake_up(&crc->go); 1436 goto out_finish; 1437 } 1438 } 1439 } 1440 1441 crc->run_threads = thr; 1442 atomic_set(&crc->ready, 1); 1443 wake_up(&crc->go); 1444 } 1445 1446 out_finish: 1447 if (crc->run_threads) { 1448 wait_event(crc->done, atomic_read(&crc->stop)); 1449 atomic_set(&crc->stop, 0); 1450 } 1451 stop = ktime_get(); 1452 if (!ret) { 1453 printk(KERN_INFO "PM: Image loading done.\n"); 1454 snapshot_write_finalize(snapshot); 1455 if (!snapshot_image_loaded(snapshot)) 1456 ret = -ENODATA; 1457 if (!ret) { 1458 if (swsusp_header->flags & SF_CRC32_MODE) { 1459 if(handle->crc32 != swsusp_header->crc32) { 1460 printk(KERN_ERR 1461 "PM: Invalid image CRC32!\n"); 1462 ret = -ENODATA; 1463 } 1464 } 1465 } 1466 } 1467 swsusp_show_speed(start, stop, nr_to_read, "Read"); 1468 out_clean: 1469 for (i = 0; i < ring_size; i++) 1470 free_page((unsigned long)page[i]); 1471 if (crc) { 1472 if (crc->thr) 1473 kthread_stop(crc->thr); 1474 kfree(crc); 1475 } 1476 if (data) { 1477 for (thr = 0; thr < nr_threads; thr++) 1478 if (data[thr].thr) 1479 kthread_stop(data[thr].thr); 1480 vfree(data); 1481 } 1482 vfree(page); 1483 1484 return ret; 1485 } 1486 1487 /** 1488 * swsusp_read - read the hibernation image. 1489 * @flags_p: flags passed by the "frozen" kernel in the image header should 1490 * be written into this memory location 1491 */ 1492 1493 int swsusp_read(unsigned int *flags_p) 1494 { 1495 int error; 1496 struct swap_map_handle handle; 1497 struct snapshot_handle snapshot; 1498 struct swsusp_info *header; 1499 1500 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 1501 error = snapshot_write_next(&snapshot); 1502 if (error < PAGE_SIZE) 1503 return error < 0 ? error : -EFAULT; 1504 header = (struct swsusp_info *)data_of(snapshot); 1505 error = get_swap_reader(&handle, flags_p); 1506 if (error) 1507 goto end; 1508 if (!error) 1509 error = swap_read_page(&handle, header, NULL); 1510 if (!error) { 1511 error = (*flags_p & SF_NOCOMPRESS_MODE) ? 1512 load_image(&handle, &snapshot, header->pages - 1) : 1513 load_image_lzo(&handle, &snapshot, header->pages - 1); 1514 } 1515 swap_reader_finish(&handle); 1516 end: 1517 if (!error) 1518 pr_debug("PM: Image successfully loaded\n"); 1519 else 1520 pr_debug("PM: Error %d resuming\n", error); 1521 return error; 1522 } 1523 1524 /** 1525 * swsusp_check - Check for swsusp signature in the resume device 1526 */ 1527 1528 int swsusp_check(void) 1529 { 1530 int error; 1531 1532 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, 1533 FMODE_READ, NULL); 1534 if (!IS_ERR(hib_resume_bdev)) { 1535 set_blocksize(hib_resume_bdev, PAGE_SIZE); 1536 clear_page(swsusp_header); 1537 error = hib_submit_io(REQ_OP_READ, READ_SYNC, 1538 swsusp_resume_block, 1539 swsusp_header, NULL); 1540 if (error) 1541 goto put; 1542 1543 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { 1544 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); 1545 /* Reset swap signature now */ 1546 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC, 1547 swsusp_resume_block, 1548 swsusp_header, NULL); 1549 } else { 1550 error = -EINVAL; 1551 } 1552 1553 put: 1554 if (error) 1555 blkdev_put(hib_resume_bdev, FMODE_READ); 1556 else 1557 pr_debug("PM: Image signature found, resuming\n"); 1558 } else { 1559 error = PTR_ERR(hib_resume_bdev); 1560 } 1561 1562 if (error) 1563 pr_debug("PM: 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("PM: 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, READ_SYNC, 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, WRITE_SYNC, 1596 swsusp_resume_block, 1597 swsusp_header, NULL); 1598 } else { 1599 printk(KERN_ERR "PM: 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 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