kernel/power/swap.c

   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
  34 #include "power.h"
  35
  36 #define HIBERNATE_SIG   "S1SUSPEND"
  37
  38 /*
  39  * When reading an {un,}compressed image, we may restore pages in place,
  40  * in which case some architectures need these pages cleaning before they
  41  * can be executed. We don't know which pages these may be, so clean the lot.
  42  */
  43 static bool clean_pages_on_read;
  44 static bool clean_pages_on_decompress;
  45
  46 /*
  47  *      The swap map is a data structure used for keeping track of each page
  48  *      written to a swap partition.  It consists of many swap_map_page
  49  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  50  *      These structures are stored on the swap and linked together with the
  51  *      help of the .next_swap member.
  52  *
  53  *      The swap map is created during suspend.  The swap map pages are
  54  *      allocated and populated one at a time, so we only need one memory
  55  *      page to set up the entire structure.
  56  *
  57  *      During resume we pick up all swap_map_page structures into a list.
  58  */
  59
  60 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  61
  62 /*
  63  * Number of free pages that are not high.
  64  */
  65 static inline unsigned long low_free_pages(void)
  66 {
  67         return nr_free_pages() - nr_free_highpages();
  68 }
  69
  70 /*
  71  * Number of pages required to be kept free while writing the image. Always
  72  * half of all available low pages before the writing starts.
  73  */
  74 static inline unsigned long reqd_free_pages(void)
  75 {
  76         return low_free_pages() / 2;
  77 }
  78
  79 struct swap_map_page {
  80         sector_t entries[MAP_PAGE_ENTRIES];
  81         sector_t next_swap;
  82 };
  83
  84 struct swap_map_page_list {
  85         struct swap_map_page *map;
  86         struct swap_map_page_list *next;
  87 };
  88
  89 /**
  90  *      The swap_map_handle structure is used for handling swap in
  91  *      a file-alike way
  92  */
  93
  94 struct swap_map_handle {
  95         struct swap_map_page *cur;
  96         struct swap_map_page_list *maps;
  97         sector_t cur_swap;
  98         sector_t first_sector;
  99         unsigned int k;
 100         unsigned long reqd_free_pages;
 101         u32 crc32;
 102 };
 103
 104 struct swsusp_header {
 105         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 106                       sizeof(u32)];
 107         u32     crc32;
 108         sector_t image;
 109         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 110         char    orig_sig[10];
 111         char    sig[10];
 112 } __packed;
 113
 114 static struct swsusp_header *swsusp_header;
 115
 116 /**
 117  *      The following functions are used for tracing the allocated
 118  *      swap pages, so that they can be freed in case of an error.
 119  */
 120
 121 struct swsusp_extent {
 122         struct rb_node node;
 123         unsigned long start;
 124         unsigned long end;
 125 };
 126
 127 static struct rb_root swsusp_extents = RB_ROOT;
 128
 129 static int swsusp_extents_insert(unsigned long swap_offset)
 130 {
 131         struct rb_node **new = &(swsusp_extents.rb_node);
 132         struct rb_node *parent = NULL;
 133         struct swsusp_extent *ext;
 134
 135         /* Figure out where to put the new node */
 136         while (*new) {
 137                 ext = rb_entry(*new, struct swsusp_extent, node);
 138                 parent = *new;
 139                 if (swap_offset < ext->start) {
 140                         /* Try to merge */
 141                         if (swap_offset == ext->start - 1) {
 142                                 ext->start--;
 143                                 return 0;
 144                         }
 145                         new = &((*new)->rb_left);
 146                 } else if (swap_offset > ext->end) {
 147                         /* Try to merge */
 148                         if (swap_offset == ext->end + 1) {
 149                                 ext->end++;
 150                                 return 0;
 151                         }
 152                         new = &((*new)->rb_right);
 153                 } else {
 154                         /* It already is in the tree */
 155                         return -EINVAL;
 156                 }
 157         }
 158         /* Add the new node and rebalance the tree. */
 159         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 160         if (!ext)
 161                 return -ENOMEM;
 162
 163         ext->start = swap_offset;
 164         ext->end = swap_offset;
 165         rb_link_node(&ext->node, parent, new);
 166         rb_insert_color(&ext->node, &swsusp_extents);
 167         return 0;
 168 }
 169
 170 /**
 171  *      alloc_swapdev_block - allocate a swap page and register that it has
 172  *      been allocated, so that it can be freed in case of an error.
 173  */
 174
 175 sector_t alloc_swapdev_block(int swap)
 176 {
 177         unsigned long offset;
 178
 179         offset = swp_offset(get_swap_page_of_type(swap));
 180         if (offset) {
 181                 if (swsusp_extents_insert(offset))
 182                         swap_free(swp_entry(swap, offset));
 183                 else
 184                         return swapdev_block(swap, offset);
 185         }
 186         return 0;
 187 }
 188
 189 /**
 190  *      free_all_swap_pages - free swap pages allocated for saving image data.
 191  *      It also frees the extents used to register which swap entries had been
 192  *      allocated.
 193  */
 194
 195 void free_all_swap_pages(int swap)
 196 {
 197         struct rb_node *node;
 198
 199         while ((node = swsusp_extents.rb_node)) {
 200                 struct swsusp_extent *ext;
 201                 unsigned long offset;
 202
 203                 ext = container_of(node, struct swsusp_extent, node);
 204                 rb_erase(node, &swsusp_extents);
 205                 for (offset = ext->start; offset <= ext->end; offset++)
 206                         swap_free(swp_entry(swap, offset));
 207
 208                 kfree(ext);
 209         }
 210 }
 211
 212 int swsusp_swap_in_use(void)
 213 {
 214         return (swsusp_extents.rb_node != NULL);
 215 }
 216
 217 /*
 218  * General things
 219  */
 220
 221 static unsigned short root_swap = 0xffff;
 222 static struct block_device *hib_resume_bdev;
 223
 224 struct hib_bio_batch {
 225         atomic_t                count;
 226         wait_queue_head_t       wait;
 227         int                     error;
 228 };
 229
 230 static void hib_init_batch(struct hib_bio_batch *hb)
 231 {
 232         atomic_set(&hb->count, 0);
 233         init_waitqueue_head(&hb->wait);
 234         hb->error = 0;
 235 }
 236
 237 static void hib_end_io(struct bio *bio, int error)
 238 {
 239         struct hib_bio_batch *hb = bio->bi_private;
 240         const int uptodate = test_bit(BIO_UPTODATE, &bio->bi_flags);
 241         struct page *page = bio->bi_io_vec[0].bv_page;
 242
 243         if (!uptodate || 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                 if (!error)
 250                         error = -EIO;
 251         }
 252
 253         if (bio_data_dir(bio) == WRITE)
 254                 put_page(page);
 255         else if (clean_pages_on_read)
 256                 flush_icache_range((unsigned long)page_address(page),
 257                                    (unsigned long)page_address(page) + PAGE_SIZE);
 258
 259         if (error && !hb->error)
 260                 hb->error = error;
 261         if (atomic_dec_and_test(&hb->count))
 262                 wake_up(&hb->wait);
 263
 264         bio_put(bio);
 265 }
 266
 267 static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
 268                 struct hib_bio_batch *hb)
 269 {
 270         struct page *page = virt_to_page(addr);
 271         struct bio *bio;
 272         int error = 0;
 273
 274         bio = bio_alloc(__GFP_WAIT | __GFP_HIGH, 1);
 275         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 276         bio->bi_bdev = hib_resume_bdev;
 277
 278         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 279                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 280                         (unsigned long long)bio->bi_iter.bi_sector);
 281                 bio_put(bio);
 282                 return -EFAULT;
 283         }
 284
 285         if (hb) {
 286                 bio->bi_end_io = hib_end_io;
 287                 bio->bi_private = hb;
 288                 atomic_inc(&hb->count);
 289                 submit_bio(rw, bio);
 290         } else {
 291                 error = submit_bio_wait(rw, bio);
 292                 bio_put(bio);
 293         }
 294
 295         return error;
 296 }
 297
 298 static int hib_wait_io(struct hib_bio_batch *hb)
 299 {
 300         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 301         return hb->error;
 302 }
 303
 304 /*
 305  * Saving part
 306  */
 307
 308 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 309 {
 310         int error;
 311
 312         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
 313         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 314             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 315                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 316                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 317                 swsusp_header->image = handle->first_sector;
 318                 swsusp_header->flags = flags;
 319                 if (flags & SF_CRC32_MODE)
 320                         swsusp_header->crc32 = handle->crc32;
 321                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
 322                                         swsusp_header, NULL);
 323         } else {
 324                 printk(KERN_ERR "PM: Swap header not found!\n");
 325                 error = -ENODEV;
 326         }
 327         return error;
 328 }
 329
 330 /**
 331  *      swsusp_swap_check - check if the resume device is a swap device
 332  *      and get its index (if so)
 333  *
 334  *      This is called before saving image
 335  */
 336 static int swsusp_swap_check(void)
 337 {
 338         int res;
 339
 340         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 341                         &hib_resume_bdev);
 342         if (res < 0)
 343                 return res;
 344
 345         root_swap = res;
 346         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 347         if (res)
 348                 return res;
 349
 350         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 351         if (res < 0)
 352                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 353
 354         return res;
 355 }
 356
 357 /**
 358  *      write_page - Write one page to given swap location.
 359  *      @buf:           Address we're writing.
 360  *      @offset:        Offset of the swap page we're writing to.
 361  *      @hb:            bio completion batch
 362  */
 363
 364 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 365 {
 366         void *src;
 367         int ret;
 368
 369         if (!offset)
 370                 return -ENOSPC;
 371
 372         if (hb) {
 373                 src = (void *)__get_free_page(__GFP_WAIT | __GFP_NOWARN |
 374                                               __GFP_NORETRY);
 375                 if (src) {
 376                         copy_page(src, buf);
 377                 } else {
 378                         ret = hib_wait_io(hb); /* Free pages */
 379                         if (ret)
 380                                 return ret;
 381                         src = (void *)__get_free_page(__GFP_WAIT |
 382                                                       __GFP_NOWARN |
 383                                                       __GFP_NORETRY);
 384                         if (src) {
 385                                 copy_page(src, buf);
 386                         } else {
 387                                 WARN_ON_ONCE(1);
 388                                 hb = NULL;      /* Go synchronous */
 389                                 src = buf;
 390                         }
 391                 }
 392         } else {
 393                 src = buf;
 394         }
 395         return hib_submit_io(WRITE_SYNC, offset, src, hb);
 396 }
 397
 398 static void release_swap_writer(struct swap_map_handle *handle)
 399 {
 400         if (handle->cur)
 401                 free_page((unsigned long)handle->cur);
 402         handle->cur = NULL;
 403 }
 404
 405 static int get_swap_writer(struct swap_map_handle *handle)
 406 {
 407         int ret;
 408
 409         ret = swsusp_swap_check();
 410         if (ret) {
 411                 if (ret != -ENOSPC)
 412                         printk(KERN_ERR "PM: Cannot find swap device, try "
 413                                         "swapon -a.\n");
 414                 return ret;
 415         }
 416         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 417         if (!handle->cur) {
 418                 ret = -ENOMEM;
 419                 goto err_close;
 420         }
 421         handle->cur_swap = alloc_swapdev_block(root_swap);
 422         if (!handle->cur_swap) {
 423                 ret = -ENOSPC;
 424                 goto err_rel;
 425         }
 426         handle->k = 0;
 427         handle->reqd_free_pages = reqd_free_pages();
 428         handle->first_sector = handle->cur_swap;
 429         return 0;
 430 err_rel:
 431         release_swap_writer(handle);
 432 err_close:
 433         swsusp_close(FMODE_WRITE);
 434         return ret;
 435 }
 436
 437 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 438                 struct hib_bio_batch *hb)
 439 {
 440         int error = 0;
 441         sector_t offset;
 442
 443         if (!handle->cur)
 444                 return -EINVAL;
 445         offset = alloc_swapdev_block(root_swap);
 446         error = write_page(buf, offset, hb);
 447         if (error)
 448                 return error;
 449         handle->cur->entries[handle->k++] = offset;
 450         if (handle->k >= MAP_PAGE_ENTRIES) {
 451                 offset = alloc_swapdev_block(root_swap);
 452                 if (!offset)
 453                         return -ENOSPC;
 454                 handle->cur->next_swap = offset;
 455                 error = write_page(handle->cur, handle->cur_swap, hb);
 456                 if (error)
 457                         goto out;
 458                 clear_page(handle->cur);
 459                 handle->cur_swap = offset;
 460                 handle->k = 0;
 461
 462                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 463                         error = hib_wait_io(hb);
 464                         if (error)
 465                                 goto out;
 466                         /*
 467                          * Recalculate the number of required free pages, to
 468                          * make sure we never take more than half.
 469                          */
 470                         handle->reqd_free_pages = reqd_free_pages();
 471                 }
 472         }
 473  out:
 474         return error;
 475 }
 476
 477 static int flush_swap_writer(struct swap_map_handle *handle)
 478 {
 479         if (handle->cur && handle->cur_swap)
 480                 return write_page(handle->cur, handle->cur_swap, NULL);
 481         else
 482                 return -EINVAL;
 483 }
 484
 485 static int swap_writer_finish(struct swap_map_handle *handle,
 486                 unsigned int flags, int error)
 487 {
 488         if (!error) {
 489                 flush_swap_writer(handle);
 490                 printk(KERN_INFO "PM: S");
 491                 error = mark_swapfiles(handle, flags);
 492                 printk("|\n");
 493         }
 494
 495         if (error)
 496                 free_all_swap_pages(root_swap);
 497         release_swap_writer(handle);
 498         swsusp_close(FMODE_WRITE);
 499
 500         return error;
 501 }
 502
 503 /* We need to remember how much compressed data we need to read. */
 504 #define LZO_HEADER      sizeof(size_t)
 505
 506 /* Number of pages/bytes we'll compress at one time. */
 507 #define LZO_UNC_PAGES   32
 508 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 509
 510 /* Number of pages/bytes we need for compressed data (worst case). */
 511 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 512                                      LZO_HEADER, PAGE_SIZE)
 513 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 514
 515 /* Maximum number of threads for compression/decompression. */
 516 #define LZO_THREADS     3
 517
 518 /* Minimum/maximum number of pages for read buffering. */
 519 #define LZO_MIN_RD_PAGES        1024
 520 #define LZO_MAX_RD_PAGES        8192
 521
 522
 523 /**
 524  *      save_image - save the suspend image data
 525  */
 526
 527 static int save_image(struct swap_map_handle *handle,
 528                       struct snapshot_handle *snapshot,
 529                       unsigned int nr_to_write)
 530 {
 531         unsigned int m;
 532         int ret;
 533         int nr_pages;
 534         int err2;
 535         struct hib_bio_batch hb;
 536         struct timeval start;
 537         struct timeval stop;
 538
 539         hib_init_batch(&hb);
 540
 541         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 542                 nr_to_write);
 543         m = nr_to_write / 10;
 544         if (!m)
 545                 m = 1;
 546         nr_pages = 0;
 547         do_gettimeofday(&start);
 548         while (1) {
 549                 ret = snapshot_read_next(snapshot);
 550                 if (ret <= 0)
 551                         break;
 552                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 553                 if (ret)
 554                         break;
 555                 if (!(nr_pages % m))
 556                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 557                                nr_pages / m * 10);
 558                 nr_pages++;
 559         }
 560         err2 = hib_wait_io(&hb);
 561         do_gettimeofday(&stop);
 562         if (!ret)
 563                 ret = err2;
 564         if (!ret)
 565                 printk(KERN_INFO "PM: Image saving done.\n");
 566         swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
 567         return ret;
 568 }
 569
 570 /**
 571  * Structure used for CRC32.
 572  */
 573 struct crc_data {
 574         struct task_struct *thr;                  /* thread */
 575         atomic_t ready;                           /* ready to start flag */
 576         atomic_t stop;                            /* ready to stop flag */
 577         unsigned run_threads;                     /* nr current threads */
 578         wait_queue_head_t go;                     /* start crc update */
 579         wait_queue_head_t done;                   /* crc update done */
 580         u32 *crc32;                               /* points to handle's crc32 */
 581         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 582         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 583 };
 584
 585 /**
 586  * CRC32 update function that runs in its own thread.
 587  */
 588 static int crc32_threadfn(void *data)
 589 {
 590         struct crc_data *d = data;
 591         unsigned i;
 592
 593         while (1) {
 594                 wait_event(d->go, atomic_read(&d->ready) ||
 595                                   kthread_should_stop());
 596                 if (kthread_should_stop()) {
 597                         d->thr = NULL;
 598                         atomic_set(&d->stop, 1);
 599                         wake_up(&d->done);
 600                         break;
 601                 }
 602                 atomic_set(&d->ready, 0);
 603
 604                 for (i = 0; i < d->run_threads; i++)
 605                         *d->crc32 = crc32_le(*d->crc32,
 606                                              d->unc[i], *d->unc_len[i]);
 607                 atomic_set(&d->stop, 1);
 608                 wake_up(&d->done);
 609         }
 610         return 0;
 611 }
 612 /**
 613  * Structure used for LZO data compression.
 614  */
 615 struct cmp_data {
 616         struct task_struct *thr;                  /* thread */
 617         atomic_t ready;                           /* ready to start flag */
 618         atomic_t stop;                            /* ready to stop flag */
 619         int ret;                                  /* return code */
 620         wait_queue_head_t go;                     /* start compression */
 621         wait_queue_head_t done;                   /* compression done */
 622         size_t unc_len;                           /* uncompressed length */
 623         size_t cmp_len;                           /* compressed length */
 624         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 625         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 626         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 627 };
 628
 629 /**
 630  * Compression function that runs in its own thread.
 631  */
 632 static int lzo_compress_threadfn(void *data)
 633 {
 634         struct cmp_data *d = data;
 635
 636         while (1) {
 637                 wait_event(d->go, atomic_read(&d->ready) ||
 638                                   kthread_should_stop());
 639                 if (kthread_should_stop()) {
 640                         d->thr = NULL;
 641                         d->ret = -1;
 642                         atomic_set(&d->stop, 1);
 643                         wake_up(&d->done);
 644                         break;
 645                 }
 646                 atomic_set(&d->ready, 0);
 647
 648                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 649                                           d->cmp + LZO_HEADER, &d->cmp_len,
 650                                           d->wrk);
 651                 atomic_set(&d->stop, 1);
 652                 wake_up(&d->done);
 653         }
 654         return 0;
 655 }
 656
 657 /**
 658  * save_image_lzo - Save the suspend image data compressed with LZO.
 659  * @handle: Swap map handle to use for saving the image.
 660  * @snapshot: Image to read data from.
 661  * @nr_to_write: Number of pages to save.
 662  */
 663 static int save_image_lzo(struct swap_map_handle *handle,
 664                           struct snapshot_handle *snapshot,
 665                           unsigned int nr_to_write)
 666 {
 667         unsigned int m;
 668         int ret = 0;
 669         int nr_pages;
 670         int err2;
 671         struct hib_bio_batch hb;
 672         struct timeval start;
 673         struct timeval stop;
 674         size_t off;
 675         unsigned thr, run_threads, nr_threads;
 676         unsigned char *page = NULL;
 677         struct cmp_data *data = NULL;
 678         struct crc_data *crc = NULL;
 679
 680         hib_init_batch(&hb);
 681
 682         /*
 683          * We'll limit the number of threads for compression to limit memory
 684          * footprint.
 685          */
 686         nr_threads = num_online_cpus() - 1;
 687         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 688
 689         page = (void *)__get_free_page(__GFP_WAIT | __GFP_HIGH);
 690         if (!page) {
 691                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 692                 ret = -ENOMEM;
 693                 goto out_clean;
 694         }
 695
 696         data = vmalloc(sizeof(*data) * nr_threads);
 697         if (!data) {
 698                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 699                 ret = -ENOMEM;
 700                 goto out_clean;
 701         }
 702         for (thr = 0; thr < nr_threads; thr++)
 703                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 704
 705         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 706         if (!crc) {
 707                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 708                 ret = -ENOMEM;
 709                 goto out_clean;
 710         }
 711         memset(crc, 0, offsetof(struct crc_data, go));
 712
 713         /*
 714          * Start the compression threads.
 715          */
 716         for (thr = 0; thr < nr_threads; thr++) {
 717                 init_waitqueue_head(&data[thr].go);
 718                 init_waitqueue_head(&data[thr].done);
 719
 720                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 721                                             &data[thr],
 722                                             "image_compress/%u", thr);
 723                 if (IS_ERR(data[thr].thr)) {
 724                         data[thr].thr = NULL;
 725                         printk(KERN_ERR
 726                                "PM: Cannot start compression threads\n");
 727                         ret = -ENOMEM;
 728                         goto out_clean;
 729                 }
 730         }
 731
 732         /*
 733          * Start the CRC32 thread.
 734          */
 735         init_waitqueue_head(&crc->go);
 736         init_waitqueue_head(&crc->done);
 737
 738         handle->crc32 = 0;
 739         crc->crc32 = &handle->crc32;
 740         for (thr = 0; thr < nr_threads; thr++) {
 741                 crc->unc[thr] = data[thr].unc;
 742                 crc->unc_len[thr] = &data[thr].unc_len;
 743         }
 744
 745         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 746         if (IS_ERR(crc->thr)) {
 747                 crc->thr = NULL;
 748                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 749                 ret = -ENOMEM;
 750                 goto out_clean;
 751         }
 752
 753         /*
 754          * Adjust the number of required free pages after all allocations have
 755          * been done. We don't want to run out of pages when writing.
 756          */
 757         handle->reqd_free_pages = reqd_free_pages();
 758
 759         printk(KERN_INFO
 760                 "PM: Using %u thread(s) for compression.\n"
 761                 "PM: Compressing and saving image data (%u pages)...\n",
 762                 nr_threads, nr_to_write);
 763         m = nr_to_write / 10;
 764         if (!m)
 765                 m = 1;
 766         nr_pages = 0;
 767         do_gettimeofday(&start);
 768         for (;;) {
 769                 for (thr = 0; thr < nr_threads; thr++) {
 770                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 771                                 ret = snapshot_read_next(snapshot);
 772                                 if (ret < 0)
 773                                         goto out_finish;
 774
 775                                 if (!ret)
 776                                         break;
 777
 778                                 memcpy(data[thr].unc + off,
 779                                        data_of(*snapshot), PAGE_SIZE);
 780
 781                                 if (!(nr_pages % m))
 782                                         printk(KERN_INFO
 783                                                "PM: Image saving progress: "
 784                                                "%3d%%\n",
 785                                                nr_pages / m * 10);
 786                                 nr_pages++;
 787                         }
 788                         if (!off)
 789                                 break;
 790
 791                         data[thr].unc_len = off;
 792
 793                         atomic_set(&data[thr].ready, 1);
 794                         wake_up(&data[thr].go);
 795                 }
 796
 797                 if (!thr)
 798                         break;
 799
 800                 crc->run_threads = thr;
 801                 atomic_set(&crc->ready, 1);
 802                 wake_up(&crc->go);
 803
 804                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 805                         wait_event(data[thr].done,
 806                                    atomic_read(&data[thr].stop));
 807                         atomic_set(&data[thr].stop, 0);
 808
 809                         ret = data[thr].ret;
 810
 811                         if (ret < 0) {
 812                                 printk(KERN_ERR "PM: LZO compression failed\n");
 813                                 goto out_finish;
 814                         }
 815
 816                         if (unlikely(!data[thr].cmp_len ||
 817                                      data[thr].cmp_len >
 818                                      lzo1x_worst_compress(data[thr].unc_len))) {
 819                                 printk(KERN_ERR
 820                                        "PM: Invalid LZO compressed length\n");
 821                                 ret = -1;
 822                                 goto out_finish;
 823                         }
 824
 825                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 826
 827                         /*
 828                          * Given we are writing one page at a time to disk, we
 829                          * copy that much from the buffer, although the last
 830                          * bit will likely be smaller than full page. This is
 831                          * OK - we saved the length of the compressed data, so
 832                          * any garbage at the end will be discarded when we
 833                          * read it.
 834                          */
 835                         for (off = 0;
 836                              off < LZO_HEADER + data[thr].cmp_len;
 837                              off += PAGE_SIZE) {
 838                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 839
 840                                 ret = swap_write_page(handle, page, &hb);
 841                                 if (ret)
 842                                         goto out_finish;
 843                         }
 844                 }
 845
 846                 wait_event(crc->done, atomic_read(&crc->stop));
 847                 atomic_set(&crc->stop, 0);
 848         }
 849
 850 out_finish:
 851         err2 = hib_wait_io(&hb);
 852         do_gettimeofday(&stop);
 853         if (!ret)
 854                 ret = err2;
 855         if (!ret)
 856                 printk(KERN_INFO "PM: Image saving done.\n");
 857         swsusp_show_speed(&start, &stop, nr_to_write, "Wrote");
 858 out_clean:
 859         if (crc) {
 860                 if (crc->thr)
 861                         kthread_stop(crc->thr);
 862                 kfree(crc);
 863         }
 864         if (data) {
 865                 for (thr = 0; thr < nr_threads; thr++)
 866                         if (data[thr].thr)
 867                                 kthread_stop(data[thr].thr);
 868                 vfree(data);
 869         }
 870         if (page) free_page((unsigned long)page);
 871
 872         return ret;
 873 }
 874
 875 /**
 876  *      enough_swap - Make sure we have enough swap to save the image.
 877  *
 878  *      Returns TRUE or FALSE after checking the total amount of swap
 879  *      space avaiable from the resume partition.
 880  */
 881
 882 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 883 {
 884         unsigned int free_swap = count_swap_pages(root_swap, 1);
 885         unsigned int required;
 886
 887         pr_debug("PM: Free swap pages: %u\n", free_swap);
 888
 889         required = PAGES_FOR_IO + nr_pages;
 890         return free_swap > required;
 891 }
 892
 893 /**
 894  *      swsusp_write - Write entire image and metadata.
 895  *      @flags: flags to pass to the "boot" kernel in the image header
 896  *
 897  *      It is important _NOT_ to umount filesystems at this point. We want
 898  *      them synced (in case something goes wrong) but we DO not want to mark
 899  *      filesystem clean: it is not. (And it does not matter, if we resume
 900  *      correctly, we'll mark system clean, anyway.)
 901  */
 902
 903 int swsusp_write(unsigned int flags)
 904 {
 905         struct swap_map_handle handle;
 906         struct snapshot_handle snapshot;
 907         struct swsusp_info *header;
 908         unsigned long pages;
 909         int error;
 910
 911         pages = snapshot_get_image_size();
 912         error = get_swap_writer(&handle);
 913         if (error) {
 914                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 915                 return error;
 916         }
 917         if (flags & SF_NOCOMPRESS_MODE) {
 918                 if (!enough_swap(pages, flags)) {
 919                         printk(KERN_ERR "PM: Not enough free swap\n");
 920                         error = -ENOSPC;
 921                         goto out_finish;
 922                 }
 923         }
 924         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 925         error = snapshot_read_next(&snapshot);
 926         if (error < PAGE_SIZE) {
 927                 if (error >= 0)
 928                         error = -EFAULT;
 929
 930                 goto out_finish;
 931         }
 932         header = (struct swsusp_info *)data_of(snapshot);
 933         error = swap_write_page(&handle, header, NULL);
 934         if (!error) {
 935                 error = (flags & SF_NOCOMPRESS_MODE) ?
 936                         save_image(&handle, &snapshot, pages - 1) :
 937                         save_image_lzo(&handle, &snapshot, pages - 1);
 938         }
 939 out_finish:
 940         error = swap_writer_finish(&handle, flags, error);
 941         return error;
 942 }
 943
 944 /**
 945  *      The following functions allow us to read data using a swap map
 946  *      in a file-alike way
 947  */
 948
 949 static void release_swap_reader(struct swap_map_handle *handle)
 950 {
 951         struct swap_map_page_list *tmp;
 952
 953         while (handle->maps) {
 954                 if (handle->maps->map)
 955                         free_page((unsigned long)handle->maps->map);
 956                 tmp = handle->maps;
 957                 handle->maps = handle->maps->next;
 958                 kfree(tmp);
 959         }
 960         handle->cur = NULL;
 961 }
 962
 963 static int get_swap_reader(struct swap_map_handle *handle,
 964                 unsigned int *flags_p)
 965 {
 966         int error;
 967         struct swap_map_page_list *tmp, *last;
 968         sector_t offset;
 969
 970         *flags_p = swsusp_header->flags;
 971
 972         if (!swsusp_header->image) /* how can this happen? */
 973                 return -EINVAL;
 974
 975         handle->cur = NULL;
 976         last = handle->maps = NULL;
 977         offset = swsusp_header->image;
 978         while (offset) {
 979                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 980                 if (!tmp) {
 981                         release_swap_reader(handle);
 982                         return -ENOMEM;
 983                 }
 984                 memset(tmp, 0, sizeof(*tmp));
 985                 if (!handle->maps)
 986                         handle->maps = tmp;
 987                 if (last)
 988                         last->next = tmp;
 989                 last = tmp;
 990
 991                 tmp->map = (struct swap_map_page *)
 992                            __get_free_page(__GFP_WAIT | __GFP_HIGH);
 993                 if (!tmp->map) {
 994                         release_swap_reader(handle);
 995                         return -ENOMEM;
 996                 }
 997
 998                 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
 999                 if (error) {
1000                         release_swap_reader(handle);
1001                         return error;
1002                 }
1003                 offset = tmp->map->next_swap;
1004         }
1005         handle->k = 0;
1006         handle->cur = handle->maps->map;
1007         return 0;
1008 }
1009
1010 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1011                 struct hib_bio_batch *hb)
1012 {
1013         sector_t offset;
1014         int error;
1015         struct swap_map_page_list *tmp;
1016
1017         if (!handle->cur)
1018                 return -EINVAL;
1019         offset = handle->cur->entries[handle->k];
1020         if (!offset)
1021                 return -EFAULT;
1022         error = hib_submit_io(READ_SYNC, offset, buf, hb);
1023         if (error)
1024                 return error;
1025         if (++handle->k >= MAP_PAGE_ENTRIES) {
1026                 handle->k = 0;
1027                 free_page((unsigned long)handle->maps->map);
1028                 tmp = handle->maps;
1029                 handle->maps = handle->maps->next;
1030                 kfree(tmp);
1031                 if (!handle->maps)
1032                         release_swap_reader(handle);
1033                 else
1034                         handle->cur = handle->maps->map;
1035         }
1036         return error;
1037 }
1038
1039 static int swap_reader_finish(struct swap_map_handle *handle)
1040 {
1041         release_swap_reader(handle);
1042
1043         return 0;
1044 }
1045
1046 /**
1047  *      load_image - load the image using the swap map handle
1048  *      @handle and the snapshot handle @snapshot
1049  *      (assume there are @nr_pages pages to load)
1050  */
1051
1052 static int load_image(struct swap_map_handle *handle,
1053                       struct snapshot_handle *snapshot,
1054                       unsigned int nr_to_read)
1055 {
1056         unsigned int m;
1057         int ret = 0;
1058         struct timeval start;
1059         struct timeval stop;
1060         struct hib_bio_batch hb;
1061         int err2;
1062         unsigned nr_pages;
1063
1064         hib_init_batch(&hb);
1065
1066         clean_pages_on_read = true;
1067         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1068                 nr_to_read);
1069         m = nr_to_read / 10;
1070         if (!m)
1071                 m = 1;
1072         nr_pages = 0;
1073         do_gettimeofday(&start);
1074         for ( ; ; ) {
1075                 ret = snapshot_write_next(snapshot);
1076                 if (ret <= 0)
1077                         break;
1078                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1079                 if (ret)
1080                         break;
1081                 if (snapshot->sync_read)
1082                         ret = hib_wait_io(&hb);
1083                 if (ret)
1084                         break;
1085                 if (!(nr_pages % m))
1086                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1087                                nr_pages / m * 10);
1088                 nr_pages++;
1089         }
1090         err2 = hib_wait_io(&hb);
1091         do_gettimeofday(&stop);
1092         if (!ret)
1093                 ret = err2;
1094         if (!ret) {
1095                 printk(KERN_INFO "PM: Image loading done.\n");
1096                 snapshot_write_finalize(snapshot);
1097                 if (!snapshot_image_loaded(snapshot))
1098                         ret = -ENODATA;
1099         }
1100         swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1101         return ret;
1102 }
1103
1104 /**
1105  * Structure used for LZO data decompression.
1106  */
1107 struct dec_data {
1108         struct task_struct *thr;                  /* thread */
1109         atomic_t ready;                           /* ready to start flag */
1110         atomic_t stop;                            /* ready to stop flag */
1111         int ret;                                  /* return code */
1112         wait_queue_head_t go;                     /* start decompression */
1113         wait_queue_head_t done;                   /* decompression done */
1114         size_t unc_len;                           /* uncompressed length */
1115         size_t cmp_len;                           /* compressed length */
1116         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1117         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1118 };
1119
1120 /**
1121  * Deompression function that runs in its own thread.
1122  */
1123 static int lzo_decompress_threadfn(void *data)
1124 {
1125         struct dec_data *d = data;
1126
1127         while (1) {
1128                 wait_event(d->go, atomic_read(&d->ready) ||
1129                                   kthread_should_stop());
1130                 if (kthread_should_stop()) {
1131                         d->thr = NULL;
1132                         d->ret = -1;
1133                         atomic_set(&d->stop, 1);
1134                         wake_up(&d->done);
1135                         break;
1136                 }
1137                 atomic_set(&d->ready, 0);
1138
1139                 d->unc_len = LZO_UNC_SIZE;
1140                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1141                                                d->unc, &d->unc_len);
1142                 if (clean_pages_on_decompress)
1143                         flush_icache_range((unsigned long)d->unc,
1144                                            (unsigned long)d->unc + d->unc_len);
1145
1146                 atomic_set(&d->stop, 1);
1147                 wake_up(&d->done);
1148         }
1149         return 0;
1150 }
1151
1152 /**
1153  * load_image_lzo - Load compressed image data and decompress them with LZO.
1154  * @handle: Swap map handle to use for loading data.
1155  * @snapshot: Image to copy uncompressed data into.
1156  * @nr_to_read: Number of pages to load.
1157  */
1158 static int load_image_lzo(struct swap_map_handle *handle,
1159                           struct snapshot_handle *snapshot,
1160                           unsigned int nr_to_read)
1161 {
1162         unsigned int m;
1163         int ret = 0;
1164         int eof = 0;
1165         struct hib_bio_batch hb;
1166         struct timeval start;
1167         struct timeval stop;
1168         unsigned nr_pages;
1169         size_t off;
1170         unsigned i, thr, run_threads, nr_threads;
1171         unsigned ring = 0, pg = 0, ring_size = 0,
1172                  have = 0, want, need, asked = 0;
1173         unsigned long read_pages = 0;
1174         unsigned char **page = NULL;
1175         struct dec_data *data = NULL;
1176         struct crc_data *crc = NULL;
1177
1178         hib_init_batch(&hb);
1179
1180         /*
1181          * We'll limit the number of threads for decompression to limit memory
1182          * footprint.
1183          */
1184         nr_threads = num_online_cpus() - 1;
1185         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1186
1187         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1188         if (!page) {
1189                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1190                 ret = -ENOMEM;
1191                 goto out_clean;
1192         }
1193
1194         data = vmalloc(sizeof(*data) * nr_threads);
1195         if (!data) {
1196                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1197                 ret = -ENOMEM;
1198                 goto out_clean;
1199         }
1200         for (thr = 0; thr < nr_threads; thr++)
1201                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1202
1203         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1204         if (!crc) {
1205                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1206                 ret = -ENOMEM;
1207                 goto out_clean;
1208         }
1209         memset(crc, 0, offsetof(struct crc_data, go));
1210
1211         clean_pages_on_decompress = true;
1212
1213         /*
1214          * Start the decompression threads.
1215          */
1216         for (thr = 0; thr < nr_threads; thr++) {
1217                 init_waitqueue_head(&data[thr].go);
1218                 init_waitqueue_head(&data[thr].done);
1219
1220                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1221                                             &data[thr],
1222                                             "image_decompress/%u", thr);
1223                 if (IS_ERR(data[thr].thr)) {
1224                         data[thr].thr = NULL;
1225                         printk(KERN_ERR
1226                                "PM: Cannot start decompression threads\n");
1227                         ret = -ENOMEM;
1228                         goto out_clean;
1229                 }
1230         }
1231
1232         /*
1233          * Start the CRC32 thread.
1234          */
1235         init_waitqueue_head(&crc->go);
1236         init_waitqueue_head(&crc->done);
1237
1238         handle->crc32 = 0;
1239         crc->crc32 = &handle->crc32;
1240         for (thr = 0; thr < nr_threads; thr++) {
1241                 crc->unc[thr] = data[thr].unc;
1242                 crc->unc_len[thr] = &data[thr].unc_len;
1243         }
1244
1245         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1246         if (IS_ERR(crc->thr)) {
1247                 crc->thr = NULL;
1248                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1249                 ret = -ENOMEM;
1250                 goto out_clean;
1251         }
1252
1253         /*
1254          * Set the number of pages for read buffering.
1255          * This is complete guesswork, because we'll only know the real
1256          * picture once prepare_image() is called, which is much later on
1257          * during the image load phase. We'll assume the worst case and
1258          * say that none of the image pages are from high memory.
1259          */
1260         if (low_free_pages() > snapshot_get_image_size())
1261                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1262         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1263
1264         for (i = 0; i < read_pages; i++) {
1265                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1266                                                   __GFP_WAIT | __GFP_HIGH :
1267                                                   __GFP_WAIT | __GFP_NOWARN |
1268                                                   __GFP_NORETRY);
1269
1270                 if (!page[i]) {
1271                         if (i < LZO_CMP_PAGES) {
1272                                 ring_size = i;
1273                                 printk(KERN_ERR
1274                                        "PM: Failed to allocate LZO pages\n");
1275                                 ret = -ENOMEM;
1276                                 goto out_clean;
1277                         } else {
1278                                 break;
1279                         }
1280                 }
1281         }
1282         want = ring_size = i;
1283
1284         printk(KERN_INFO
1285                 "PM: Using %u thread(s) for decompression.\n"
1286                 "PM: Loading and decompressing image data (%u pages)...\n",
1287                 nr_threads, nr_to_read);
1288         m = nr_to_read / 10;
1289         if (!m)
1290                 m = 1;
1291         nr_pages = 0;
1292         do_gettimeofday(&start);
1293
1294         ret = snapshot_write_next(snapshot);
1295         if (ret <= 0)
1296                 goto out_finish;
1297
1298         for(;;) {
1299                 for (i = 0; !eof && i < want; i++) {
1300                         ret = swap_read_page(handle, page[ring], &hb);
1301                         if (ret) {
1302                                 /*
1303                                  * On real read error, finish. On end of data,
1304                                  * set EOF flag and just exit the read loop.
1305                                  */
1306                                 if (handle->cur &&
1307                                     handle->cur->entries[handle->k]) {
1308                                         goto out_finish;
1309                                 } else {
1310                                         eof = 1;
1311                                         break;
1312                                 }
1313                         }
1314                         if (++ring >= ring_size)
1315                                 ring = 0;
1316                 }
1317                 asked += i;
1318                 want -= i;
1319
1320                 /*
1321                  * We are out of data, wait for some more.
1322                  */
1323                 if (!have) {
1324                         if (!asked)
1325                                 break;
1326
1327                         ret = hib_wait_io(&hb);
1328                         if (ret)
1329                                 goto out_finish;
1330                         have += asked;
1331                         asked = 0;
1332                         if (eof)
1333                                 eof = 2;
1334                 }
1335
1336                 if (crc->run_threads) {
1337                         wait_event(crc->done, atomic_read(&crc->stop));
1338                         atomic_set(&crc->stop, 0);
1339                         crc->run_threads = 0;
1340                 }
1341
1342                 for (thr = 0; have && thr < nr_threads; thr++) {
1343                         data[thr].cmp_len = *(size_t *)page[pg];
1344                         if (unlikely(!data[thr].cmp_len ||
1345                                      data[thr].cmp_len >
1346                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1347                                 printk(KERN_ERR
1348                                        "PM: Invalid LZO compressed length\n");
1349                                 ret = -1;
1350                                 goto out_finish;
1351                         }
1352
1353                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1354                                             PAGE_SIZE);
1355                         if (need > have) {
1356                                 if (eof > 1) {
1357                                         ret = -1;
1358                                         goto out_finish;
1359                                 }
1360                                 break;
1361                         }
1362
1363                         for (off = 0;
1364                              off < LZO_HEADER + data[thr].cmp_len;
1365                              off += PAGE_SIZE) {
1366                                 memcpy(data[thr].cmp + off,
1367                                        page[pg], PAGE_SIZE);
1368                                 have--;
1369                                 want++;
1370                                 if (++pg >= ring_size)
1371                                         pg = 0;
1372                         }
1373
1374                         atomic_set(&data[thr].ready, 1);
1375                         wake_up(&data[thr].go);
1376                 }
1377
1378                 /*
1379                  * Wait for more data while we are decompressing.
1380                  */
1381                 if (have < LZO_CMP_PAGES && asked) {
1382                         ret = hib_wait_io(&hb);
1383                         if (ret)
1384                                 goto out_finish;
1385                         have += asked;
1386                         asked = 0;
1387                         if (eof)
1388                                 eof = 2;
1389                 }
1390
1391                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1392                         wait_event(data[thr].done,
1393                                    atomic_read(&data[thr].stop));
1394                         atomic_set(&data[thr].stop, 0);
1395
1396                         ret = data[thr].ret;
1397
1398                         if (ret < 0) {
1399                                 printk(KERN_ERR
1400                                        "PM: LZO decompression failed\n");
1401                                 goto out_finish;
1402                         }
1403
1404                         if (unlikely(!data[thr].unc_len ||
1405                                      data[thr].unc_len > LZO_UNC_SIZE ||
1406                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1407                                 printk(KERN_ERR
1408                                        "PM: Invalid LZO uncompressed length\n");
1409                                 ret = -1;
1410                                 goto out_finish;
1411                         }
1412
1413                         for (off = 0;
1414                              off < data[thr].unc_len; off += PAGE_SIZE) {
1415                                 memcpy(data_of(*snapshot),
1416                                        data[thr].unc + off, PAGE_SIZE);
1417
1418                                 if (!(nr_pages % m))
1419                                         printk(KERN_INFO
1420                                                "PM: Image loading progress: "
1421                                                "%3d%%\n",
1422                                                nr_pages / m * 10);
1423                                 nr_pages++;
1424
1425                                 ret = snapshot_write_next(snapshot);
1426                                 if (ret <= 0) {
1427                                         crc->run_threads = thr + 1;
1428                                         atomic_set(&crc->ready, 1);
1429                                         wake_up(&crc->go);
1430                                         goto out_finish;
1431                                 }
1432                         }
1433                 }
1434
1435                 crc->run_threads = thr;
1436                 atomic_set(&crc->ready, 1);
1437                 wake_up(&crc->go);
1438         }
1439
1440 out_finish:
1441         if (crc->run_threads) {
1442                 wait_event(crc->done, atomic_read(&crc->stop));
1443                 atomic_set(&crc->stop, 0);
1444         }
1445         do_gettimeofday(&stop);
1446         if (!ret) {
1447                 printk(KERN_INFO "PM: Image loading done.\n");
1448                 snapshot_write_finalize(snapshot);
1449                 if (!snapshot_image_loaded(snapshot))
1450                         ret = -ENODATA;
1451                 if (!ret) {
1452                         if (swsusp_header->flags & SF_CRC32_MODE) {
1453                                 if(handle->crc32 != swsusp_header->crc32) {
1454                                         printk(KERN_ERR
1455                                                "PM: Invalid image CRC32!\n");
1456                                         ret = -ENODATA;
1457                                 }
1458                         }
1459                 }
1460         }
1461         swsusp_show_speed(&start, &stop, nr_to_read, "Read");
1462 out_clean:
1463         for (i = 0; i < ring_size; i++)
1464                 free_page((unsigned long)page[i]);
1465         if (crc) {
1466                 if (crc->thr)
1467                         kthread_stop(crc->thr);
1468                 kfree(crc);
1469         }
1470         if (data) {
1471                 for (thr = 0; thr < nr_threads; thr++)
1472                         if (data[thr].thr)
1473                                 kthread_stop(data[thr].thr);
1474                 vfree(data);
1475         }
1476         if (page) vfree(page);
1477
1478         return ret;
1479 }
1480
1481 /**
1482  *      swsusp_read - read the hibernation image.
1483  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1484  *                be written into this memory location
1485  */
1486
1487 int swsusp_read(unsigned int *flags_p)
1488 {
1489         int error;
1490         struct swap_map_handle handle;
1491         struct snapshot_handle snapshot;
1492         struct swsusp_info *header;
1493
1494         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1495         error = snapshot_write_next(&snapshot);
1496         if (error < PAGE_SIZE)
1497                 return error < 0 ? error : -EFAULT;
1498         header = (struct swsusp_info *)data_of(snapshot);
1499         error = get_swap_reader(&handle, flags_p);
1500         if (error)
1501                 goto end;
1502         if (!error)
1503                 error = swap_read_page(&handle, header, NULL);
1504         if (!error) {
1505                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1506                         load_image(&handle, &snapshot, header->pages - 1) :
1507                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1508         }
1509         swap_reader_finish(&handle);
1510 end:
1511         if (!error)
1512                 pr_debug("PM: Image successfully loaded\n");
1513         else
1514                 pr_debug("PM: Error %d resuming\n", error);
1515         return error;
1516 }
1517
1518 /**
1519  *      swsusp_check - Check for swsusp signature in the resume device
1520  */
1521
1522 int swsusp_check(void)
1523 {
1524         int error;
1525
1526         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1527                                             FMODE_READ, NULL);
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(READ_SYNC, swsusp_resume_block,
1532                                         swsusp_header, NULL);
1533                 if (error)
1534                         goto put;
1535
1536                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1537                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1538                         /* Reset swap signature now */
1539                         error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1540                                                 swsusp_header, NULL);
1541                 } else {
1542                         error = -EINVAL;
1543                 }
1544
1545 put:
1546                 if (error)
1547                         blkdev_put(hib_resume_bdev, FMODE_READ);
1548                 else
1549                         pr_debug("PM: Image signature found, resuming\n");
1550         } else {
1551                 error = PTR_ERR(hib_resume_bdev);
1552         }
1553
1554         if (error)
1555                 pr_debug("PM: Image not found (code %d)\n", error);
1556
1557         return error;
1558 }
1559
1560 /**
1561  *      swsusp_close - close swap device.
1562  */
1563
1564 void swsusp_close(fmode_t mode)
1565 {
1566         if (IS_ERR(hib_resume_bdev)) {
1567                 pr_debug("PM: Image device not initialised\n");
1568                 return;
1569         }
1570
1571         blkdev_put(hib_resume_bdev, mode);
1572 }
1573
1574 /**
1575  *      swsusp_unmark - Unmark swsusp signature in the resume device
1576  */
1577
1578 #ifdef CONFIG_SUSPEND
1579 int swsusp_unmark(void)
1580 {
1581         int error;
1582
1583         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1584         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1585                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1586                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1587                                         swsusp_header, NULL);
1588         } else {
1589                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1590                 error = -ENODEV;
1591         }
1592
1593         /*
1594          * We just returned from suspend, we don't need the image any more.
1595          */
1596         free_all_swap_pages(root_swap);
1597
1598         return error;
1599 }
1600 #endif
1601
1602 static int swsusp_header_init(void)
1603 {
1604         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1605         if (!swsusp_header)
1606                 panic("Could not allocate memory for swsusp_header\n");
1607         return 0;
1608 }
1609
1610 core_initcall(swsusp_header_init);