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 + ((flags & SF_NOCOMPRESS_MODE) ? 777 nr_pages : (nr_pages * LZO_CMP_PAGES) / LZO_UNC_PAGES + 1); 778 return free_swap > required; 779 } 780 781 /** 782 * swsusp_write - Write entire image and metadata. 783 * @flags: flags to pass to the "boot" kernel in the image header 784 * 785 * It is important _NOT_ to umount filesystems at this point. We want 786 * them synced (in case something goes wrong) but we DO not want to mark 787 * filesystem clean: it is not. (And it does not matter, if we resume 788 * correctly, we'll mark system clean, anyway.) 789 */ 790 791 int swsusp_write(unsigned int flags) 792 { 793 struct swap_map_handle handle; 794 struct snapshot_handle snapshot; 795 struct swsusp_info *header; 796 unsigned long pages; 797 int error; 798 799 pages = snapshot_get_image_size(); 800 error = get_swap_writer(&handle); 801 if (error) { 802 printk(KERN_ERR "PM: Cannot get swap writer\n"); 803 return error; 804 } 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 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 811 error = snapshot_read_next(&snapshot); 812 if (error < PAGE_SIZE) { 813 if (error >= 0) 814 error = -EFAULT; 815 816 goto out_finish; 817 } 818 header = (struct swsusp_info *)data_of(snapshot); 819 error = swap_write_page(&handle, header, NULL); 820 if (!error) { 821 error = (flags & SF_NOCOMPRESS_MODE) ? 822 save_image(&handle, &snapshot, pages - 1) : 823 save_image_lzo(&handle, &snapshot, pages - 1); 824 } 825 out_finish: 826 error = swap_writer_finish(&handle, flags, error); 827 return error; 828 } 829 830 /** 831 * The following functions allow us to read data using a swap map 832 * in a file-alike way 833 */ 834 835 static void release_swap_reader(struct swap_map_handle *handle) 836 { 837 struct swap_map_page_list *tmp; 838 839 while (handle->maps) { 840 if (handle->maps->map) 841 free_page((unsigned long)handle->maps->map); 842 tmp = handle->maps; 843 handle->maps = handle->maps->next; 844 kfree(tmp); 845 } 846 handle->cur = NULL; 847 } 848 849 static int get_swap_reader(struct swap_map_handle *handle, 850 unsigned int *flags_p) 851 { 852 int error; 853 struct swap_map_page_list *tmp, *last; 854 sector_t offset; 855 856 *flags_p = swsusp_header->flags; 857 858 if (!swsusp_header->image) /* how can this happen? */ 859 return -EINVAL; 860 861 handle->cur = NULL; 862 last = handle->maps = NULL; 863 offset = swsusp_header->image; 864 while (offset) { 865 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL); 866 if (!tmp) { 867 release_swap_reader(handle); 868 return -ENOMEM; 869 } 870 memset(tmp, 0, sizeof(*tmp)); 871 if (!handle->maps) 872 handle->maps = tmp; 873 if (last) 874 last->next = tmp; 875 last = tmp; 876 877 tmp->map = (struct swap_map_page *) 878 __get_free_page(__GFP_WAIT | __GFP_HIGH); 879 if (!tmp->map) { 880 release_swap_reader(handle); 881 return -ENOMEM; 882 } 883 884 error = hib_bio_read_page(offset, tmp->map, NULL); 885 if (error) { 886 release_swap_reader(handle); 887 return error; 888 } 889 offset = tmp->map->next_swap; 890 } 891 handle->k = 0; 892 handle->cur = handle->maps->map; 893 return 0; 894 } 895 896 static int swap_read_page(struct swap_map_handle *handle, void *buf, 897 struct bio **bio_chain) 898 { 899 sector_t offset; 900 int error; 901 struct swap_map_page_list *tmp; 902 903 if (!handle->cur) 904 return -EINVAL; 905 offset = handle->cur->entries[handle->k]; 906 if (!offset) 907 return -EFAULT; 908 error = hib_bio_read_page(offset, buf, bio_chain); 909 if (error) 910 return error; 911 if (++handle->k >= MAP_PAGE_ENTRIES) { 912 handle->k = 0; 913 free_page((unsigned long)handle->maps->map); 914 tmp = handle->maps; 915 handle->maps = handle->maps->next; 916 kfree(tmp); 917 if (!handle->maps) 918 release_swap_reader(handle); 919 else 920 handle->cur = handle->maps->map; 921 } 922 return error; 923 } 924 925 static int swap_reader_finish(struct swap_map_handle *handle) 926 { 927 release_swap_reader(handle); 928 929 return 0; 930 } 931 932 /** 933 * load_image - load the image using the swap map handle 934 * @handle and the snapshot handle @snapshot 935 * (assume there are @nr_pages pages to load) 936 */ 937 938 static int load_image(struct swap_map_handle *handle, 939 struct snapshot_handle *snapshot, 940 unsigned int nr_to_read) 941 { 942 unsigned int m; 943 int ret = 0; 944 struct timeval start; 945 struct timeval stop; 946 struct bio *bio; 947 int err2; 948 unsigned nr_pages; 949 950 printk(KERN_INFO "PM: Loading image data pages (%u pages) ... ", 951 nr_to_read); 952 m = nr_to_read / 100; 953 if (!m) 954 m = 1; 955 nr_pages = 0; 956 bio = NULL; 957 do_gettimeofday(&start); 958 for ( ; ; ) { 959 ret = snapshot_write_next(snapshot); 960 if (ret <= 0) 961 break; 962 ret = swap_read_page(handle, data_of(*snapshot), &bio); 963 if (ret) 964 break; 965 if (snapshot->sync_read) 966 ret = hib_wait_on_bio_chain(&bio); 967 if (ret) 968 break; 969 if (!(nr_pages % m)) 970 printk("\b\b\b\b%3d%%", nr_pages / m); 971 nr_pages++; 972 } 973 err2 = hib_wait_on_bio_chain(&bio); 974 do_gettimeofday(&stop); 975 if (!ret) 976 ret = err2; 977 if (!ret) { 978 printk("\b\b\b\bdone\n"); 979 snapshot_write_finalize(snapshot); 980 if (!snapshot_image_loaded(snapshot)) 981 ret = -ENODATA; 982 } else 983 printk("\n"); 984 swsusp_show_speed(&start, &stop, nr_to_read, "Read"); 985 return ret; 986 } 987 988 /** 989 * Structure used for LZO data decompression. 990 */ 991 struct dec_data { 992 struct task_struct *thr; /* thread */ 993 atomic_t ready; /* ready to start flag */ 994 atomic_t stop; /* ready to stop flag */ 995 int ret; /* return code */ 996 wait_queue_head_t go; /* start decompression */ 997 wait_queue_head_t done; /* decompression done */ 998 size_t unc_len; /* uncompressed length */ 999 size_t cmp_len; /* compressed length */ 1000 unsigned char unc[LZO_UNC_SIZE]; /* uncompressed buffer */ 1001 unsigned char cmp[LZO_CMP_SIZE]; /* compressed buffer */ 1002 }; 1003 1004 /** 1005 * Deompression function that runs in its own thread. 1006 */ 1007 static int lzo_decompress_threadfn(void *data) 1008 { 1009 struct dec_data *d = data; 1010 1011 while (1) { 1012 wait_event(d->go, atomic_read(&d->ready) || 1013 kthread_should_stop()); 1014 if (kthread_should_stop()) { 1015 d->thr = NULL; 1016 d->ret = -1; 1017 atomic_set(&d->stop, 1); 1018 wake_up(&d->done); 1019 break; 1020 } 1021 atomic_set(&d->ready, 0); 1022 1023 d->unc_len = LZO_UNC_SIZE; 1024 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len, 1025 d->unc, &d->unc_len); 1026 atomic_set(&d->stop, 1); 1027 wake_up(&d->done); 1028 } 1029 return 0; 1030 } 1031 1032 /** 1033 * load_image_lzo - Load compressed image data and decompress them with LZO. 1034 * @handle: Swap map handle to use for loading data. 1035 * @snapshot: Image to copy uncompressed data into. 1036 * @nr_to_read: Number of pages to load. 1037 */ 1038 static int load_image_lzo(struct swap_map_handle *handle, 1039 struct snapshot_handle *snapshot, 1040 unsigned int nr_to_read) 1041 { 1042 unsigned int m; 1043 int ret = 0; 1044 int eof = 0; 1045 struct bio *bio; 1046 struct timeval start; 1047 struct timeval stop; 1048 unsigned nr_pages; 1049 size_t off; 1050 unsigned i, thr, run_threads, nr_threads; 1051 unsigned ring = 0, pg = 0, ring_size = 0, 1052 have = 0, want, need, asked = 0; 1053 unsigned long read_pages; 1054 unsigned char **page = NULL; 1055 struct dec_data *data = NULL; 1056 struct crc_data *crc = NULL; 1057 1058 /* 1059 * We'll limit the number of threads for decompression to limit memory 1060 * footprint. 1061 */ 1062 nr_threads = num_online_cpus() - 1; 1063 nr_threads = clamp_val(nr_threads, 1, LZO_THREADS); 1064 1065 page = vmalloc(sizeof(*page) * LZO_READ_PAGES); 1066 if (!page) { 1067 printk(KERN_ERR "PM: Failed to allocate LZO page\n"); 1068 ret = -ENOMEM; 1069 goto out_clean; 1070 } 1071 1072 data = vmalloc(sizeof(*data) * nr_threads); 1073 if (!data) { 1074 printk(KERN_ERR "PM: Failed to allocate LZO data\n"); 1075 ret = -ENOMEM; 1076 goto out_clean; 1077 } 1078 for (thr = 0; thr < nr_threads; thr++) 1079 memset(&data[thr], 0, offsetof(struct dec_data, go)); 1080 1081 crc = kmalloc(sizeof(*crc), GFP_KERNEL); 1082 if (!crc) { 1083 printk(KERN_ERR "PM: Failed to allocate crc\n"); 1084 ret = -ENOMEM; 1085 goto out_clean; 1086 } 1087 memset(crc, 0, offsetof(struct crc_data, go)); 1088 1089 /* 1090 * Start the decompression threads. 1091 */ 1092 for (thr = 0; thr < nr_threads; thr++) { 1093 init_waitqueue_head(&data[thr].go); 1094 init_waitqueue_head(&data[thr].done); 1095 1096 data[thr].thr = kthread_run(lzo_decompress_threadfn, 1097 &data[thr], 1098 "image_decompress/%u", thr); 1099 if (IS_ERR(data[thr].thr)) { 1100 data[thr].thr = NULL; 1101 printk(KERN_ERR 1102 "PM: Cannot start decompression threads\n"); 1103 ret = -ENOMEM; 1104 goto out_clean; 1105 } 1106 } 1107 1108 /* 1109 * Start the CRC32 thread. 1110 */ 1111 init_waitqueue_head(&crc->go); 1112 init_waitqueue_head(&crc->done); 1113 1114 handle->crc32 = 0; 1115 crc->crc32 = &handle->crc32; 1116 for (thr = 0; thr < nr_threads; thr++) { 1117 crc->unc[thr] = data[thr].unc; 1118 crc->unc_len[thr] = &data[thr].unc_len; 1119 } 1120 1121 crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32"); 1122 if (IS_ERR(crc->thr)) { 1123 crc->thr = NULL; 1124 printk(KERN_ERR "PM: Cannot start CRC32 thread\n"); 1125 ret = -ENOMEM; 1126 goto out_clean; 1127 } 1128 1129 /* 1130 * Adjust number of pages for read buffering, in case we are short. 1131 */ 1132 read_pages = (nr_free_pages() - snapshot_get_image_size()) >> 1; 1133 read_pages = clamp_val(read_pages, LZO_CMP_PAGES, LZO_READ_PAGES); 1134 1135 for (i = 0; i < read_pages; i++) { 1136 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ? 1137 __GFP_WAIT | __GFP_HIGH : 1138 __GFP_WAIT); 1139 if (!page[i]) { 1140 if (i < LZO_CMP_PAGES) { 1141 ring_size = i; 1142 printk(KERN_ERR 1143 "PM: Failed to allocate LZO pages\n"); 1144 ret = -ENOMEM; 1145 goto out_clean; 1146 } else { 1147 break; 1148 } 1149 } 1150 } 1151 want = ring_size = i; 1152 1153 printk(KERN_INFO 1154 "PM: Using %u thread(s) for decompression.\n" 1155 "PM: Loading and decompressing image data (%u pages) ... ", 1156 nr_threads, nr_to_read); 1157 m = nr_to_read / 100; 1158 if (!m) 1159 m = 1; 1160 nr_pages = 0; 1161 bio = NULL; 1162 do_gettimeofday(&start); 1163 1164 ret = snapshot_write_next(snapshot); 1165 if (ret <= 0) 1166 goto out_finish; 1167 1168 for(;;) { 1169 for (i = 0; !eof && i < want; i++) { 1170 ret = swap_read_page(handle, page[ring], &bio); 1171 if (ret) { 1172 /* 1173 * On real read error, finish. On end of data, 1174 * set EOF flag and just exit the read loop. 1175 */ 1176 if (handle->cur && 1177 handle->cur->entries[handle->k]) { 1178 goto out_finish; 1179 } else { 1180 eof = 1; 1181 break; 1182 } 1183 } 1184 if (++ring >= ring_size) 1185 ring = 0; 1186 } 1187 asked += i; 1188 want -= i; 1189 1190 /* 1191 * We are out of data, wait for some more. 1192 */ 1193 if (!have) { 1194 if (!asked) 1195 break; 1196 1197 ret = hib_wait_on_bio_chain(&bio); 1198 if (ret) 1199 goto out_finish; 1200 have += asked; 1201 asked = 0; 1202 if (eof) 1203 eof = 2; 1204 } 1205 1206 if (crc->run_threads) { 1207 wait_event(crc->done, atomic_read(&crc->stop)); 1208 atomic_set(&crc->stop, 0); 1209 crc->run_threads = 0; 1210 } 1211 1212 for (thr = 0; have && thr < nr_threads; thr++) { 1213 data[thr].cmp_len = *(size_t *)page[pg]; 1214 if (unlikely(!data[thr].cmp_len || 1215 data[thr].cmp_len > 1216 lzo1x_worst_compress(LZO_UNC_SIZE))) { 1217 printk(KERN_ERR 1218 "PM: Invalid LZO compressed length\n"); 1219 ret = -1; 1220 goto out_finish; 1221 } 1222 1223 need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER, 1224 PAGE_SIZE); 1225 if (need > have) { 1226 if (eof > 1) { 1227 ret = -1; 1228 goto out_finish; 1229 } 1230 break; 1231 } 1232 1233 for (off = 0; 1234 off < LZO_HEADER + data[thr].cmp_len; 1235 off += PAGE_SIZE) { 1236 memcpy(data[thr].cmp + off, 1237 page[pg], PAGE_SIZE); 1238 have--; 1239 want++; 1240 if (++pg >= ring_size) 1241 pg = 0; 1242 } 1243 1244 atomic_set(&data[thr].ready, 1); 1245 wake_up(&data[thr].go); 1246 } 1247 1248 /* 1249 * Wait for more data while we are decompressing. 1250 */ 1251 if (have < LZO_CMP_PAGES && asked) { 1252 ret = hib_wait_on_bio_chain(&bio); 1253 if (ret) 1254 goto out_finish; 1255 have += asked; 1256 asked = 0; 1257 if (eof) 1258 eof = 2; 1259 } 1260 1261 for (run_threads = thr, thr = 0; thr < run_threads; thr++) { 1262 wait_event(data[thr].done, 1263 atomic_read(&data[thr].stop)); 1264 atomic_set(&data[thr].stop, 0); 1265 1266 ret = data[thr].ret; 1267 1268 if (ret < 0) { 1269 printk(KERN_ERR 1270 "PM: LZO decompression failed\n"); 1271 goto out_finish; 1272 } 1273 1274 if (unlikely(!data[thr].unc_len || 1275 data[thr].unc_len > LZO_UNC_SIZE || 1276 data[thr].unc_len & (PAGE_SIZE - 1))) { 1277 printk(KERN_ERR 1278 "PM: Invalid LZO uncompressed length\n"); 1279 ret = -1; 1280 goto out_finish; 1281 } 1282 1283 for (off = 0; 1284 off < data[thr].unc_len; off += PAGE_SIZE) { 1285 memcpy(data_of(*snapshot), 1286 data[thr].unc + off, PAGE_SIZE); 1287 1288 if (!(nr_pages % m)) 1289 printk("\b\b\b\b%3d%%", nr_pages / m); 1290 nr_pages++; 1291 1292 ret = snapshot_write_next(snapshot); 1293 if (ret <= 0) { 1294 crc->run_threads = thr + 1; 1295 atomic_set(&crc->ready, 1); 1296 wake_up(&crc->go); 1297 goto out_finish; 1298 } 1299 } 1300 } 1301 1302 crc->run_threads = thr; 1303 atomic_set(&crc->ready, 1); 1304 wake_up(&crc->go); 1305 } 1306 1307 out_finish: 1308 if (crc->run_threads) { 1309 wait_event(crc->done, atomic_read(&crc->stop)); 1310 atomic_set(&crc->stop, 0); 1311 } 1312 do_gettimeofday(&stop); 1313 if (!ret) { 1314 printk("\b\b\b\bdone\n"); 1315 snapshot_write_finalize(snapshot); 1316 if (!snapshot_image_loaded(snapshot)) 1317 ret = -ENODATA; 1318 if (!ret) { 1319 if (swsusp_header->flags & SF_CRC32_MODE) { 1320 if(handle->crc32 != swsusp_header->crc32) { 1321 printk(KERN_ERR 1322 "PM: Invalid image CRC32!\n"); 1323 ret = -ENODATA; 1324 } 1325 } 1326 } 1327 } else 1328 printk("\n"); 1329 swsusp_show_speed(&start, &stop, nr_to_read, "Read"); 1330 out_clean: 1331 for (i = 0; i < ring_size; i++) 1332 free_page((unsigned long)page[i]); 1333 if (crc) { 1334 if (crc->thr) 1335 kthread_stop(crc->thr); 1336 kfree(crc); 1337 } 1338 if (data) { 1339 for (thr = 0; thr < nr_threads; thr++) 1340 if (data[thr].thr) 1341 kthread_stop(data[thr].thr); 1342 vfree(data); 1343 } 1344 if (page) vfree(page); 1345 1346 return ret; 1347 } 1348 1349 /** 1350 * swsusp_read - read the hibernation image. 1351 * @flags_p: flags passed by the "frozen" kernel in the image header should 1352 * be written into this memory location 1353 */ 1354 1355 int swsusp_read(unsigned int *flags_p) 1356 { 1357 int error; 1358 struct swap_map_handle handle; 1359 struct snapshot_handle snapshot; 1360 struct swsusp_info *header; 1361 1362 memset(&snapshot, 0, sizeof(struct snapshot_handle)); 1363 error = snapshot_write_next(&snapshot); 1364 if (error < PAGE_SIZE) 1365 return error < 0 ? error : -EFAULT; 1366 header = (struct swsusp_info *)data_of(snapshot); 1367 error = get_swap_reader(&handle, flags_p); 1368 if (error) 1369 goto end; 1370 if (!error) 1371 error = swap_read_page(&handle, header, NULL); 1372 if (!error) { 1373 error = (*flags_p & SF_NOCOMPRESS_MODE) ? 1374 load_image(&handle, &snapshot, header->pages - 1) : 1375 load_image_lzo(&handle, &snapshot, header->pages - 1); 1376 } 1377 swap_reader_finish(&handle); 1378 end: 1379 if (!error) 1380 pr_debug("PM: Image successfully loaded\n"); 1381 else 1382 pr_debug("PM: Error %d resuming\n", error); 1383 return error; 1384 } 1385 1386 /** 1387 * swsusp_check - Check for swsusp signature in the resume device 1388 */ 1389 1390 int swsusp_check(void) 1391 { 1392 int error; 1393 1394 hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, 1395 FMODE_READ, NULL); 1396 if (!IS_ERR(hib_resume_bdev)) { 1397 set_blocksize(hib_resume_bdev, PAGE_SIZE); 1398 clear_page(swsusp_header); 1399 error = hib_bio_read_page(swsusp_resume_block, 1400 swsusp_header, NULL); 1401 if (error) 1402 goto put; 1403 1404 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) { 1405 memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10); 1406 /* Reset swap signature now */ 1407 error = hib_bio_write_page(swsusp_resume_block, 1408 swsusp_header, NULL); 1409 } else { 1410 error = -EINVAL; 1411 } 1412 1413 put: 1414 if (error) 1415 blkdev_put(hib_resume_bdev, FMODE_READ); 1416 else 1417 pr_debug("PM: Image signature found, resuming\n"); 1418 } else { 1419 error = PTR_ERR(hib_resume_bdev); 1420 } 1421 1422 if (error) 1423 pr_debug("PM: Image not found (code %d)\n", error); 1424 1425 return error; 1426 } 1427 1428 /** 1429 * swsusp_close - close swap device. 1430 */ 1431 1432 void swsusp_close(fmode_t mode) 1433 { 1434 if (IS_ERR(hib_resume_bdev)) { 1435 pr_debug("PM: Image device not initialised\n"); 1436 return; 1437 } 1438 1439 blkdev_put(hib_resume_bdev, mode); 1440 } 1441 1442 static int swsusp_header_init(void) 1443 { 1444 swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL); 1445 if (!swsusp_header) 1446 panic("Could not allocate memory for swsusp_header\n"); 1447 return 0; 1448 } 1449 1450 core_initcall(swsusp_header_init); 1451