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 #include <linux/ktime.h>
  34
  35 #include "power.h"
  36
  37 #define HIBERNATE_SIG   "S1SUSPEND"
  38
  39 /*
  40  *      The swap map is a data structure used for keeping track of each page
  41  *      written to a swap partition.  It consists of many swap_map_page
  42  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  43  *      These structures are stored on the swap and linked together with the
  44  *      help of the .next_swap member.
  45  *
  46  *      The swap map is created during suspend.  The swap map pages are
  47  *      allocated and populated one at a time, so we only need one memory
  48  *      page to set up the entire structure.
  49  *
  50  *      During resume we pick up all swap_map_page structures into a list.
  51  */
  52
  53 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  54
  55 /*
  56  * Number of free pages that are not high.
  57  */
  58 static inline unsigned long low_free_pages(void)
  59 {
  60         return nr_free_pages() - nr_free_highpages();
  61 }
  62
  63 /*
  64  * Number of pages required to be kept free while writing the image. Always
  65  * half of all available low pages before the writing starts.
  66  */
  67 static inline unsigned long reqd_free_pages(void)
  68 {
  69         return low_free_pages() / 2;
  70 }
  71
  72 struct swap_map_page {
  73         sector_t entries[MAP_PAGE_ENTRIES];
  74         sector_t next_swap;
  75 };
  76
  77 struct swap_map_page_list {
  78         struct swap_map_page *map;
  79         struct swap_map_page_list *next;
  80 };
  81
  82 /**
  83  *      The swap_map_handle structure is used for handling swap in
  84  *      a file-alike way
  85  */
  86
  87 struct swap_map_handle {
  88         struct swap_map_page *cur;
  89         struct swap_map_page_list *maps;
  90         sector_t cur_swap;
  91         sector_t first_sector;
  92         unsigned int k;
  93         unsigned long reqd_free_pages;
  94         u32 crc32;
  95 };
  96
  97 struct swsusp_header {
  98         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
  99                       sizeof(u32)];
 100         u32     crc32;
 101         sector_t image;
 102         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 103         char    orig_sig[10];
 104         char    sig[10];
 105 } __packed;
 106
 107 static struct swsusp_header *swsusp_header;
 108
 109 /**
 110  *      The following functions are used for tracing the allocated
 111  *      swap pages, so that they can be freed in case of an error.
 112  */
 113
 114 struct swsusp_extent {
 115         struct rb_node node;
 116         unsigned long start;
 117         unsigned long end;
 118 };
 119
 120 static struct rb_root swsusp_extents = RB_ROOT;
 121
 122 static int swsusp_extents_insert(unsigned long swap_offset)
 123 {
 124         struct rb_node **new = &(swsusp_extents.rb_node);
 125         struct rb_node *parent = NULL;
 126         struct swsusp_extent *ext;
 127
 128         /* Figure out where to put the new node */
 129         while (*new) {
 130                 ext = rb_entry(*new, struct swsusp_extent, node);
 131                 parent = *new;
 132                 if (swap_offset < ext->start) {
 133                         /* Try to merge */
 134                         if (swap_offset == ext->start - 1) {
 135                                 ext->start--;
 136                                 return 0;
 137                         }
 138                         new = &((*new)->rb_left);
 139                 } else if (swap_offset > ext->end) {
 140                         /* Try to merge */
 141                         if (swap_offset == ext->end + 1) {
 142                                 ext->end++;
 143                                 return 0;
 144                         }
 145                         new = &((*new)->rb_right);
 146                 } else {
 147                         /* It already is in the tree */
 148                         return -EINVAL;
 149                 }
 150         }
 151         /* Add the new node and rebalance the tree. */
 152         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 153         if (!ext)
 154                 return -ENOMEM;
 155
 156         ext->start = swap_offset;
 157         ext->end = swap_offset;
 158         rb_link_node(&ext->node, parent, new);
 159         rb_insert_color(&ext->node, &swsusp_extents);
 160         return 0;
 161 }
 162
 163 /**
 164  *      alloc_swapdev_block - allocate a swap page and register that it has
 165  *      been allocated, so that it can be freed in case of an error.
 166  */
 167
 168 sector_t alloc_swapdev_block(int swap)
 169 {
 170         unsigned long offset;
 171
 172         offset = swp_offset(get_swap_page_of_type(swap));
 173         if (offset) {
 174                 if (swsusp_extents_insert(offset))
 175                         swap_free(swp_entry(swap, offset));
 176                 else
 177                         return swapdev_block(swap, offset);
 178         }
 179         return 0;
 180 }
 181
 182 /**
 183  *      free_all_swap_pages - free swap pages allocated for saving image data.
 184  *      It also frees the extents used to register which swap entries had been
 185  *      allocated.
 186  */
 187
 188 void free_all_swap_pages(int swap)
 189 {
 190         struct rb_node *node;
 191
 192         while ((node = swsusp_extents.rb_node)) {
 193                 struct swsusp_extent *ext;
 194                 unsigned long offset;
 195
 196                 ext = container_of(node, struct swsusp_extent, node);
 197                 rb_erase(node, &swsusp_extents);
 198                 for (offset = ext->start; offset <= ext->end; offset++)
 199                         swap_free(swp_entry(swap, offset));
 200
 201                 kfree(ext);
 202         }
 203 }
 204
 205 int swsusp_swap_in_use(void)
 206 {
 207         return (swsusp_extents.rb_node != NULL);
 208 }
 209
 210 /*
 211  * General things
 212  */
 213
 214 static unsigned short root_swap = 0xffff;
 215 static struct block_device *hib_resume_bdev;
 216
 217 struct hib_bio_batch {
 218         atomic_t                count;
 219         wait_queue_head_t       wait;
 220         int                     error;
 221 };
 222
 223 static void hib_init_batch(struct hib_bio_batch *hb)
 224 {
 225         atomic_set(&hb->count, 0);
 226         init_waitqueue_head(&hb->wait);
 227         hb->error = 0;
 228 }
 229
 230 static void hib_end_io(struct bio *bio)
 231 {
 232         struct hib_bio_batch *hb = bio->bi_private;
 233         struct page *page = bio->bi_io_vec[0].bv_page;
 234
 235         if (bio->bi_error) {
 236                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 237                                 imajor(bio->bi_bdev->bd_inode),
 238                                 iminor(bio->bi_bdev->bd_inode),
 239                                 (unsigned long long)bio->bi_iter.bi_sector);
 240         }
 241
 242         if (bio_data_dir(bio) == WRITE)
 243                 put_page(page);
 244
 245         if (bio->bi_error && !hb->error)
 246                 hb->error = bio->bi_error;
 247         if (atomic_dec_and_test(&hb->count))
 248                 wake_up(&hb->wait);
 249
 250         bio_put(bio);
 251 }
 252
 253 static int hib_submit_io(int rw, pgoff_t page_off, void *addr,
 254                 struct hib_bio_batch *hb)
 255 {
 256         struct page *page = virt_to_page(addr);
 257         struct bio *bio;
 258         int error = 0;
 259
 260         bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
 261         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 262         bio->bi_bdev = hib_resume_bdev;
 263
 264         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 265                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 266                         (unsigned long long)bio->bi_iter.bi_sector);
 267                 bio_put(bio);
 268                 return -EFAULT;
 269         }
 270
 271         if (hb) {
 272                 bio->bi_end_io = hib_end_io;
 273                 bio->bi_private = hb;
 274                 atomic_inc(&hb->count);
 275                 submit_bio(rw, bio);
 276         } else {
 277                 error = submit_bio_wait(rw, bio);
 278                 bio_put(bio);
 279         }
 280
 281         return error;
 282 }
 283
 284 static int hib_wait_io(struct hib_bio_batch *hb)
 285 {
 286         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 287         return hb->error;
 288 }
 289
 290 /*
 291  * Saving part
 292  */
 293
 294 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 295 {
 296         int error;
 297
 298         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
 299         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 300             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 301                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 302                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 303                 swsusp_header->image = handle->first_sector;
 304                 swsusp_header->flags = flags;
 305                 if (flags & SF_CRC32_MODE)
 306                         swsusp_header->crc32 = handle->crc32;
 307                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
 308                                         swsusp_header, NULL);
 309         } else {
 310                 printk(KERN_ERR "PM: Swap header not found!\n");
 311                 error = -ENODEV;
 312         }
 313         return error;
 314 }
 315
 316 /**
 317  *      swsusp_swap_check - check if the resume device is a swap device
 318  *      and get its index (if so)
 319  *
 320  *      This is called before saving image
 321  */
 322 static int swsusp_swap_check(void)
 323 {
 324         int res;
 325
 326         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 327                         &hib_resume_bdev);
 328         if (res < 0)
 329                 return res;
 330
 331         root_swap = res;
 332         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 333         if (res)
 334                 return res;
 335
 336         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 337         if (res < 0)
 338                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 339
 340         return res;
 341 }
 342
 343 /**
 344  *      write_page - Write one page to given swap location.
 345  *      @buf:           Address we're writing.
 346  *      @offset:        Offset of the swap page we're writing to.
 347  *      @hb:            bio completion batch
 348  */
 349
 350 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 351 {
 352         void *src;
 353         int ret;
 354
 355         if (!offset)
 356                 return -ENOSPC;
 357
 358         if (hb) {
 359                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 360                                               __GFP_NORETRY);
 361                 if (src) {
 362                         copy_page(src, buf);
 363                 } else {
 364                         ret = hib_wait_io(hb); /* Free pages */
 365                         if (ret)
 366                                 return ret;
 367                         src = (void *)__get_free_page(__GFP_RECLAIM |
 368                                                       __GFP_NOWARN |
 369                                                       __GFP_NORETRY);
 370                         if (src) {
 371                                 copy_page(src, buf);
 372                         } else {
 373                                 WARN_ON_ONCE(1);
 374                                 hb = NULL;      /* Go synchronous */
 375                                 src = buf;
 376                         }
 377                 }
 378         } else {
 379                 src = buf;
 380         }
 381         return hib_submit_io(WRITE_SYNC, offset, src, hb);
 382 }
 383
 384 static void release_swap_writer(struct swap_map_handle *handle)
 385 {
 386         if (handle->cur)
 387                 free_page((unsigned long)handle->cur);
 388         handle->cur = NULL;
 389 }
 390
 391 static int get_swap_writer(struct swap_map_handle *handle)
 392 {
 393         int ret;
 394
 395         ret = swsusp_swap_check();
 396         if (ret) {
 397                 if (ret != -ENOSPC)
 398                         printk(KERN_ERR "PM: Cannot find swap device, try "
 399                                         "swapon -a.\n");
 400                 return ret;
 401         }
 402         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 403         if (!handle->cur) {
 404                 ret = -ENOMEM;
 405                 goto err_close;
 406         }
 407         handle->cur_swap = alloc_swapdev_block(root_swap);
 408         if (!handle->cur_swap) {
 409                 ret = -ENOSPC;
 410                 goto err_rel;
 411         }
 412         handle->k = 0;
 413         handle->reqd_free_pages = reqd_free_pages();
 414         handle->first_sector = handle->cur_swap;
 415         return 0;
 416 err_rel:
 417         release_swap_writer(handle);
 418 err_close:
 419         swsusp_close(FMODE_WRITE);
 420         return ret;
 421 }
 422
 423 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 424                 struct hib_bio_batch *hb)
 425 {
 426         int error = 0;
 427         sector_t offset;
 428
 429         if (!handle->cur)
 430                 return -EINVAL;
 431         offset = alloc_swapdev_block(root_swap);
 432         error = write_page(buf, offset, hb);
 433         if (error)
 434                 return error;
 435         handle->cur->entries[handle->k++] = offset;
 436         if (handle->k >= MAP_PAGE_ENTRIES) {
 437                 offset = alloc_swapdev_block(root_swap);
 438                 if (!offset)
 439                         return -ENOSPC;
 440                 handle->cur->next_swap = offset;
 441                 error = write_page(handle->cur, handle->cur_swap, hb);
 442                 if (error)
 443                         goto out;
 444                 clear_page(handle->cur);
 445                 handle->cur_swap = offset;
 446                 handle->k = 0;
 447
 448                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 449                         error = hib_wait_io(hb);
 450                         if (error)
 451                                 goto out;
 452                         /*
 453                          * Recalculate the number of required free pages, to
 454                          * make sure we never take more than half.
 455                          */
 456                         handle->reqd_free_pages = reqd_free_pages();
 457                 }
 458         }
 459  out:
 460         return error;
 461 }
 462
 463 static int flush_swap_writer(struct swap_map_handle *handle)
 464 {
 465         if (handle->cur && handle->cur_swap)
 466                 return write_page(handle->cur, handle->cur_swap, NULL);
 467         else
 468                 return -EINVAL;
 469 }
 470
 471 static int swap_writer_finish(struct swap_map_handle *handle,
 472                 unsigned int flags, int error)
 473 {
 474         if (!error) {
 475                 flush_swap_writer(handle);
 476                 printk(KERN_INFO "PM: S");
 477                 error = mark_swapfiles(handle, flags);
 478                 printk("|\n");
 479         }
 480
 481         if (error)
 482                 free_all_swap_pages(root_swap);
 483         release_swap_writer(handle);
 484         swsusp_close(FMODE_WRITE);
 485
 486         return error;
 487 }
 488
 489 /* We need to remember how much compressed data we need to read. */
 490 #define LZO_HEADER      sizeof(size_t)
 491
 492 /* Number of pages/bytes we'll compress at one time. */
 493 #define LZO_UNC_PAGES   32
 494 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 495
 496 /* Number of pages/bytes we need for compressed data (worst case). */
 497 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 498                                      LZO_HEADER, PAGE_SIZE)
 499 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 500
 501 /* Maximum number of threads for compression/decompression. */
 502 #define LZO_THREADS     3
 503
 504 /* Minimum/maximum number of pages for read buffering. */
 505 #define LZO_MIN_RD_PAGES        1024
 506 #define LZO_MAX_RD_PAGES        8192
 507
 508
 509 /**
 510  *      save_image - save the suspend image data
 511  */
 512
 513 static int save_image(struct swap_map_handle *handle,
 514                       struct snapshot_handle *snapshot,
 515                       unsigned int nr_to_write)
 516 {
 517         unsigned int m;
 518         int ret;
 519         int nr_pages;
 520         int err2;
 521         struct hib_bio_batch hb;
 522         ktime_t start;
 523         ktime_t stop;
 524
 525         hib_init_batch(&hb);
 526
 527         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 528                 nr_to_write);
 529         m = nr_to_write / 10;
 530         if (!m)
 531                 m = 1;
 532         nr_pages = 0;
 533         start = ktime_get();
 534         while (1) {
 535                 ret = snapshot_read_next(snapshot);
 536                 if (ret <= 0)
 537                         break;
 538                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 539                 if (ret)
 540                         break;
 541                 if (!(nr_pages % m))
 542                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 543                                nr_pages / m * 10);
 544                 nr_pages++;
 545         }
 546         err2 = hib_wait_io(&hb);
 547         stop = ktime_get();
 548         if (!ret)
 549                 ret = err2;
 550         if (!ret)
 551                 printk(KERN_INFO "PM: Image saving done.\n");
 552         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 553         return ret;
 554 }
 555
 556 /**
 557  * Structure used for CRC32.
 558  */
 559 struct crc_data {
 560         struct task_struct *thr;                  /* thread */
 561         atomic_t ready;                           /* ready to start flag */
 562         atomic_t stop;                            /* ready to stop flag */
 563         unsigned run_threads;                     /* nr current threads */
 564         wait_queue_head_t go;                     /* start crc update */
 565         wait_queue_head_t done;                   /* crc update done */
 566         u32 *crc32;                               /* points to handle's crc32 */
 567         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 568         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 569 };
 570
 571 /**
 572  * CRC32 update function that runs in its own thread.
 573  */
 574 static int crc32_threadfn(void *data)
 575 {
 576         struct crc_data *d = data;
 577         unsigned i;
 578
 579         while (1) {
 580                 wait_event(d->go, atomic_read(&d->ready) ||
 581                                   kthread_should_stop());
 582                 if (kthread_should_stop()) {
 583                         d->thr = NULL;
 584                         atomic_set(&d->stop, 1);
 585                         wake_up(&d->done);
 586                         break;
 587                 }
 588                 atomic_set(&d->ready, 0);
 589
 590                 for (i = 0; i < d->run_threads; i++)
 591                         *d->crc32 = crc32_le(*d->crc32,
 592                                              d->unc[i], *d->unc_len[i]);
 593                 atomic_set(&d->stop, 1);
 594                 wake_up(&d->done);
 595         }
 596         return 0;
 597 }
 598 /**
 599  * Structure used for LZO data compression.
 600  */
 601 struct cmp_data {
 602         struct task_struct *thr;                  /* thread */
 603         atomic_t ready;                           /* ready to start flag */
 604         atomic_t stop;                            /* ready to stop flag */
 605         int ret;                                  /* return code */
 606         wait_queue_head_t go;                     /* start compression */
 607         wait_queue_head_t done;                   /* compression done */
 608         size_t unc_len;                           /* uncompressed length */
 609         size_t cmp_len;                           /* compressed length */
 610         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 611         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 612         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 613 };
 614
 615 /**
 616  * Compression function that runs in its own thread.
 617  */
 618 static int lzo_compress_threadfn(void *data)
 619 {
 620         struct cmp_data *d = data;
 621
 622         while (1) {
 623                 wait_event(d->go, atomic_read(&d->ready) ||
 624                                   kthread_should_stop());
 625                 if (kthread_should_stop()) {
 626                         d->thr = NULL;
 627                         d->ret = -1;
 628                         atomic_set(&d->stop, 1);
 629                         wake_up(&d->done);
 630                         break;
 631                 }
 632                 atomic_set(&d->ready, 0);
 633
 634                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 635                                           d->cmp + LZO_HEADER, &d->cmp_len,
 636                                           d->wrk);
 637                 atomic_set(&d->stop, 1);
 638                 wake_up(&d->done);
 639         }
 640         return 0;
 641 }
 642
 643 /**
 644  * save_image_lzo - Save the suspend image data compressed with LZO.
 645  * @handle: Swap map handle to use for saving the image.
 646  * @snapshot: Image to read data from.
 647  * @nr_to_write: Number of pages to save.
 648  */
 649 static int save_image_lzo(struct swap_map_handle *handle,
 650                           struct snapshot_handle *snapshot,
 651                           unsigned int nr_to_write)
 652 {
 653         unsigned int m;
 654         int ret = 0;
 655         int nr_pages;
 656         int err2;
 657         struct hib_bio_batch hb;
 658         ktime_t start;
 659         ktime_t stop;
 660         size_t off;
 661         unsigned thr, run_threads, nr_threads;
 662         unsigned char *page = NULL;
 663         struct cmp_data *data = NULL;
 664         struct crc_data *crc = NULL;
 665
 666         hib_init_batch(&hb);
 667
 668         /*
 669          * We'll limit the number of threads for compression to limit memory
 670          * footprint.
 671          */
 672         nr_threads = num_online_cpus() - 1;
 673         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 674
 675         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 676         if (!page) {
 677                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 678                 ret = -ENOMEM;
 679                 goto out_clean;
 680         }
 681
 682         data = vmalloc(sizeof(*data) * nr_threads);
 683         if (!data) {
 684                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 685                 ret = -ENOMEM;
 686                 goto out_clean;
 687         }
 688         for (thr = 0; thr < nr_threads; thr++)
 689                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 690
 691         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 692         if (!crc) {
 693                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 694                 ret = -ENOMEM;
 695                 goto out_clean;
 696         }
 697         memset(crc, 0, offsetof(struct crc_data, go));
 698
 699         /*
 700          * Start the compression threads.
 701          */
 702         for (thr = 0; thr < nr_threads; thr++) {
 703                 init_waitqueue_head(&data[thr].go);
 704                 init_waitqueue_head(&data[thr].done);
 705
 706                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 707                                             &data[thr],
 708                                             "image_compress/%u", thr);
 709                 if (IS_ERR(data[thr].thr)) {
 710                         data[thr].thr = NULL;
 711                         printk(KERN_ERR
 712                                "PM: Cannot start compression threads\n");
 713                         ret = -ENOMEM;
 714                         goto out_clean;
 715                 }
 716         }
 717
 718         /*
 719          * Start the CRC32 thread.
 720          */
 721         init_waitqueue_head(&crc->go);
 722         init_waitqueue_head(&crc->done);
 723
 724         handle->crc32 = 0;
 725         crc->crc32 = &handle->crc32;
 726         for (thr = 0; thr < nr_threads; thr++) {
 727                 crc->unc[thr] = data[thr].unc;
 728                 crc->unc_len[thr] = &data[thr].unc_len;
 729         }
 730
 731         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 732         if (IS_ERR(crc->thr)) {
 733                 crc->thr = NULL;
 734                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 735                 ret = -ENOMEM;
 736                 goto out_clean;
 737         }
 738
 739         /*
 740          * Adjust the number of required free pages after all allocations have
 741          * been done. We don't want to run out of pages when writing.
 742          */
 743         handle->reqd_free_pages = reqd_free_pages();
 744
 745         printk(KERN_INFO
 746                 "PM: Using %u thread(s) for compression.\n"
 747                 "PM: Compressing and saving image data (%u pages)...\n",
 748                 nr_threads, nr_to_write);
 749         m = nr_to_write / 10;
 750         if (!m)
 751                 m = 1;
 752         nr_pages = 0;
 753         start = ktime_get();
 754         for (;;) {
 755                 for (thr = 0; thr < nr_threads; thr++) {
 756                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 757                                 ret = snapshot_read_next(snapshot);
 758                                 if (ret < 0)
 759                                         goto out_finish;
 760
 761                                 if (!ret)
 762                                         break;
 763
 764                                 memcpy(data[thr].unc + off,
 765                                        data_of(*snapshot), PAGE_SIZE);
 766
 767                                 if (!(nr_pages % m))
 768                                         printk(KERN_INFO
 769                                                "PM: Image saving progress: "
 770                                                "%3d%%\n",
 771                                                nr_pages / m * 10);
 772                                 nr_pages++;
 773                         }
 774                         if (!off)
 775                                 break;
 776
 777                         data[thr].unc_len = off;
 778
 779                         atomic_set(&data[thr].ready, 1);
 780                         wake_up(&data[thr].go);
 781                 }
 782
 783                 if (!thr)
 784                         break;
 785
 786                 crc->run_threads = thr;
 787                 atomic_set(&crc->ready, 1);
 788                 wake_up(&crc->go);
 789
 790                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 791                         wait_event(data[thr].done,
 792                                    atomic_read(&data[thr].stop));
 793                         atomic_set(&data[thr].stop, 0);
 794
 795                         ret = data[thr].ret;
 796
 797                         if (ret < 0) {
 798                                 printk(KERN_ERR "PM: LZO compression failed\n");
 799                                 goto out_finish;
 800                         }
 801
 802                         if (unlikely(!data[thr].cmp_len ||
 803                                      data[thr].cmp_len >
 804                                      lzo1x_worst_compress(data[thr].unc_len))) {
 805                                 printk(KERN_ERR
 806                                        "PM: Invalid LZO compressed length\n");
 807                                 ret = -1;
 808                                 goto out_finish;
 809                         }
 810
 811                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 812
 813                         /*
 814                          * Given we are writing one page at a time to disk, we
 815                          * copy that much from the buffer, although the last
 816                          * bit will likely be smaller than full page. This is
 817                          * OK - we saved the length of the compressed data, so
 818                          * any garbage at the end will be discarded when we
 819                          * read it.
 820                          */
 821                         for (off = 0;
 822                              off < LZO_HEADER + data[thr].cmp_len;
 823                              off += PAGE_SIZE) {
 824                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 825
 826                                 ret = swap_write_page(handle, page, &hb);
 827                                 if (ret)
 828                                         goto out_finish;
 829                         }
 830                 }
 831
 832                 wait_event(crc->done, atomic_read(&crc->stop));
 833                 atomic_set(&crc->stop, 0);
 834         }
 835
 836 out_finish:
 837         err2 = hib_wait_io(&hb);
 838         stop = ktime_get();
 839         if (!ret)
 840                 ret = err2;
 841         if (!ret)
 842                 printk(KERN_INFO "PM: Image saving done.\n");
 843         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 844 out_clean:
 845         if (crc) {
 846                 if (crc->thr)
 847                         kthread_stop(crc->thr);
 848                 kfree(crc);
 849         }
 850         if (data) {
 851                 for (thr = 0; thr < nr_threads; thr++)
 852                         if (data[thr].thr)
 853                                 kthread_stop(data[thr].thr);
 854                 vfree(data);
 855         }
 856         if (page) free_page((unsigned long)page);
 857
 858         return ret;
 859 }
 860
 861 /**
 862  *      enough_swap - Make sure we have enough swap to save the image.
 863  *
 864  *      Returns TRUE or FALSE after checking the total amount of swap
 865  *      space avaiable from the resume partition.
 866  */
 867
 868 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 869 {
 870         unsigned int free_swap = count_swap_pages(root_swap, 1);
 871         unsigned int required;
 872
 873         pr_debug("PM: Free swap pages: %u\n", free_swap);
 874
 875         required = PAGES_FOR_IO + nr_pages;
 876         return free_swap > required;
 877 }
 878
 879 /**
 880  *      swsusp_write - Write entire image and metadata.
 881  *      @flags: flags to pass to the "boot" kernel in the image header
 882  *
 883  *      It is important _NOT_ to umount filesystems at this point. We want
 884  *      them synced (in case something goes wrong) but we DO not want to mark
 885  *      filesystem clean: it is not. (And it does not matter, if we resume
 886  *      correctly, we'll mark system clean, anyway.)
 887  */
 888
 889 int swsusp_write(unsigned int flags)
 890 {
 891         struct swap_map_handle handle;
 892         struct snapshot_handle snapshot;
 893         struct swsusp_info *header;
 894         unsigned long pages;
 895         int error;
 896
 897         pages = snapshot_get_image_size();
 898         error = get_swap_writer(&handle);
 899         if (error) {
 900                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 901                 return error;
 902         }
 903         if (flags & SF_NOCOMPRESS_MODE) {
 904                 if (!enough_swap(pages, flags)) {
 905                         printk(KERN_ERR "PM: Not enough free swap\n");
 906                         error = -ENOSPC;
 907                         goto out_finish;
 908                 }
 909         }
 910         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 911         error = snapshot_read_next(&snapshot);
 912         if (error < PAGE_SIZE) {
 913                 if (error >= 0)
 914                         error = -EFAULT;
 915
 916                 goto out_finish;
 917         }
 918         header = (struct swsusp_info *)data_of(snapshot);
 919         error = swap_write_page(&handle, header, NULL);
 920         if (!error) {
 921                 error = (flags & SF_NOCOMPRESS_MODE) ?
 922                         save_image(&handle, &snapshot, pages - 1) :
 923                         save_image_lzo(&handle, &snapshot, pages - 1);
 924         }
 925 out_finish:
 926         error = swap_writer_finish(&handle, flags, error);
 927         return error;
 928 }
 929
 930 /**
 931  *      The following functions allow us to read data using a swap map
 932  *      in a file-alike way
 933  */
 934
 935 static void release_swap_reader(struct swap_map_handle *handle)
 936 {
 937         struct swap_map_page_list *tmp;
 938
 939         while (handle->maps) {
 940                 if (handle->maps->map)
 941                         free_page((unsigned long)handle->maps->map);
 942                 tmp = handle->maps;
 943                 handle->maps = handle->maps->next;
 944                 kfree(tmp);
 945         }
 946         handle->cur = NULL;
 947 }
 948
 949 static int get_swap_reader(struct swap_map_handle *handle,
 950                 unsigned int *flags_p)
 951 {
 952         int error;
 953         struct swap_map_page_list *tmp, *last;
 954         sector_t offset;
 955
 956         *flags_p = swsusp_header->flags;
 957
 958         if (!swsusp_header->image) /* how can this happen? */
 959                 return -EINVAL;
 960
 961         handle->cur = NULL;
 962         last = handle->maps = NULL;
 963         offset = swsusp_header->image;
 964         while (offset) {
 965                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 966                 if (!tmp) {
 967                         release_swap_reader(handle);
 968                         return -ENOMEM;
 969                 }
 970                 memset(tmp, 0, sizeof(*tmp));
 971                 if (!handle->maps)
 972                         handle->maps = tmp;
 973                 if (last)
 974                         last->next = tmp;
 975                 last = tmp;
 976
 977                 tmp->map = (struct swap_map_page *)
 978                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 979                 if (!tmp->map) {
 980                         release_swap_reader(handle);
 981                         return -ENOMEM;
 982                 }
 983
 984                 error = hib_submit_io(READ_SYNC, offset, tmp->map, NULL);
 985                 if (error) {
 986                         release_swap_reader(handle);
 987                         return error;
 988                 }
 989                 offset = tmp->map->next_swap;
 990         }
 991         handle->k = 0;
 992         handle->cur = handle->maps->map;
 993         return 0;
 994 }
 995
 996 static int swap_read_page(struct swap_map_handle *handle, void *buf,
 997                 struct hib_bio_batch *hb)
 998 {
 999         sector_t offset;
1000         int error;
1001         struct swap_map_page_list *tmp;
1002
1003         if (!handle->cur)
1004                 return -EINVAL;
1005         offset = handle->cur->entries[handle->k];
1006         if (!offset)
1007                 return -EFAULT;
1008         error = hib_submit_io(READ_SYNC, offset, buf, hb);
1009         if (error)
1010                 return error;
1011         if (++handle->k >= MAP_PAGE_ENTRIES) {
1012                 handle->k = 0;
1013                 free_page((unsigned long)handle->maps->map);
1014                 tmp = handle->maps;
1015                 handle->maps = handle->maps->next;
1016                 kfree(tmp);
1017                 if (!handle->maps)
1018                         release_swap_reader(handle);
1019                 else
1020                         handle->cur = handle->maps->map;
1021         }
1022         return error;
1023 }
1024
1025 static int swap_reader_finish(struct swap_map_handle *handle)
1026 {
1027         release_swap_reader(handle);
1028
1029         return 0;
1030 }
1031
1032 /**
1033  *      load_image - load the image using the swap map handle
1034  *      @handle and the snapshot handle @snapshot
1035  *      (assume there are @nr_pages pages to load)
1036  */
1037
1038 static int load_image(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         ktime_t start;
1045         ktime_t stop;
1046         struct hib_bio_batch hb;
1047         int err2;
1048         unsigned nr_pages;
1049
1050         hib_init_batch(&hb);
1051
1052         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1053                 nr_to_read);
1054         m = nr_to_read / 10;
1055         if (!m)
1056                 m = 1;
1057         nr_pages = 0;
1058         start = ktime_get();
1059         for ( ; ; ) {
1060                 ret = snapshot_write_next(snapshot);
1061                 if (ret <= 0)
1062                         break;
1063                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1064                 if (ret)
1065                         break;
1066                 if (snapshot->sync_read)
1067                         ret = hib_wait_io(&hb);
1068                 if (ret)
1069                         break;
1070                 if (!(nr_pages % m))
1071                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1072                                nr_pages / m * 10);
1073                 nr_pages++;
1074         }
1075         err2 = hib_wait_io(&hb);
1076         stop = ktime_get();
1077         if (!ret)
1078                 ret = err2;
1079         if (!ret) {
1080                 printk(KERN_INFO "PM: Image loading done.\n");
1081                 snapshot_write_finalize(snapshot);
1082                 if (!snapshot_image_loaded(snapshot))
1083                         ret = -ENODATA;
1084         }
1085         swsusp_show_speed(start, stop, nr_to_read, "Read");
1086         return ret;
1087 }
1088
1089 /**
1090  * Structure used for LZO data decompression.
1091  */
1092 struct dec_data {
1093         struct task_struct *thr;                  /* thread */
1094         atomic_t ready;                           /* ready to start flag */
1095         atomic_t stop;                            /* ready to stop flag */
1096         int ret;                                  /* return code */
1097         wait_queue_head_t go;                     /* start decompression */
1098         wait_queue_head_t done;                   /* decompression done */
1099         size_t unc_len;                           /* uncompressed length */
1100         size_t cmp_len;                           /* compressed length */
1101         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1102         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1103 };
1104
1105 /**
1106  * Deompression function that runs in its own thread.
1107  */
1108 static int lzo_decompress_threadfn(void *data)
1109 {
1110         struct dec_data *d = data;
1111
1112         while (1) {
1113                 wait_event(d->go, atomic_read(&d->ready) ||
1114                                   kthread_should_stop());
1115                 if (kthread_should_stop()) {
1116                         d->thr = NULL;
1117                         d->ret = -1;
1118                         atomic_set(&d->stop, 1);
1119                         wake_up(&d->done);
1120                         break;
1121                 }
1122                 atomic_set(&d->ready, 0);
1123
1124                 d->unc_len = LZO_UNC_SIZE;
1125                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1126                                                d->unc, &d->unc_len);
1127                 atomic_set(&d->stop, 1);
1128                 wake_up(&d->done);
1129         }
1130         return 0;
1131 }
1132
1133 /**
1134  * load_image_lzo - Load compressed image data and decompress them with LZO.
1135  * @handle: Swap map handle to use for loading data.
1136  * @snapshot: Image to copy uncompressed data into.
1137  * @nr_to_read: Number of pages to load.
1138  */
1139 static int load_image_lzo(struct swap_map_handle *handle,
1140                           struct snapshot_handle *snapshot,
1141                           unsigned int nr_to_read)
1142 {
1143         unsigned int m;
1144         int ret = 0;
1145         int eof = 0;
1146         struct hib_bio_batch hb;
1147         ktime_t start;
1148         ktime_t stop;
1149         unsigned nr_pages;
1150         size_t off;
1151         unsigned i, thr, run_threads, nr_threads;
1152         unsigned ring = 0, pg = 0, ring_size = 0,
1153                  have = 0, want, need, asked = 0;
1154         unsigned long read_pages = 0;
1155         unsigned char **page = NULL;
1156         struct dec_data *data = NULL;
1157         struct crc_data *crc = NULL;
1158
1159         hib_init_batch(&hb);
1160
1161         /*
1162          * We'll limit the number of threads for decompression to limit memory
1163          * footprint.
1164          */
1165         nr_threads = num_online_cpus() - 1;
1166         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1167
1168         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1169         if (!page) {
1170                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1171                 ret = -ENOMEM;
1172                 goto out_clean;
1173         }
1174
1175         data = vmalloc(sizeof(*data) * nr_threads);
1176         if (!data) {
1177                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1178                 ret = -ENOMEM;
1179                 goto out_clean;
1180         }
1181         for (thr = 0; thr < nr_threads; thr++)
1182                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1183
1184         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1185         if (!crc) {
1186                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1187                 ret = -ENOMEM;
1188                 goto out_clean;
1189         }
1190         memset(crc, 0, offsetof(struct crc_data, go));
1191
1192         /*
1193          * Start the decompression threads.
1194          */
1195         for (thr = 0; thr < nr_threads; thr++) {
1196                 init_waitqueue_head(&data[thr].go);
1197                 init_waitqueue_head(&data[thr].done);
1198
1199                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1200                                             &data[thr],
1201                                             "image_decompress/%u", thr);
1202                 if (IS_ERR(data[thr].thr)) {
1203                         data[thr].thr = NULL;
1204                         printk(KERN_ERR
1205                                "PM: Cannot start decompression threads\n");
1206                         ret = -ENOMEM;
1207                         goto out_clean;
1208                 }
1209         }
1210
1211         /*
1212          * Start the CRC32 thread.
1213          */
1214         init_waitqueue_head(&crc->go);
1215         init_waitqueue_head(&crc->done);
1216
1217         handle->crc32 = 0;
1218         crc->crc32 = &handle->crc32;
1219         for (thr = 0; thr < nr_threads; thr++) {
1220                 crc->unc[thr] = data[thr].unc;
1221                 crc->unc_len[thr] = &data[thr].unc_len;
1222         }
1223
1224         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1225         if (IS_ERR(crc->thr)) {
1226                 crc->thr = NULL;
1227                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1228                 ret = -ENOMEM;
1229                 goto out_clean;
1230         }
1231
1232         /*
1233          * Set the number of pages for read buffering.
1234          * This is complete guesswork, because we'll only know the real
1235          * picture once prepare_image() is called, which is much later on
1236          * during the image load phase. We'll assume the worst case and
1237          * say that none of the image pages are from high memory.
1238          */
1239         if (low_free_pages() > snapshot_get_image_size())
1240                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1241         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1242
1243         for (i = 0; i < read_pages; i++) {
1244                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1245                                                   __GFP_RECLAIM | __GFP_HIGH :
1246                                                   __GFP_RECLAIM | __GFP_NOWARN |
1247                                                   __GFP_NORETRY);
1248
1249                 if (!page[i]) {
1250                         if (i < LZO_CMP_PAGES) {
1251                                 ring_size = i;
1252                                 printk(KERN_ERR
1253                                        "PM: Failed to allocate LZO pages\n");
1254                                 ret = -ENOMEM;
1255                                 goto out_clean;
1256                         } else {
1257                                 break;
1258                         }
1259                 }
1260         }
1261         want = ring_size = i;
1262
1263         printk(KERN_INFO
1264                 "PM: Using %u thread(s) for decompression.\n"
1265                 "PM: Loading and decompressing image data (%u pages)...\n",
1266                 nr_threads, nr_to_read);
1267         m = nr_to_read / 10;
1268         if (!m)
1269                 m = 1;
1270         nr_pages = 0;
1271         start = ktime_get();
1272
1273         ret = snapshot_write_next(snapshot);
1274         if (ret <= 0)
1275                 goto out_finish;
1276
1277         for(;;) {
1278                 for (i = 0; !eof && i < want; i++) {
1279                         ret = swap_read_page(handle, page[ring], &hb);
1280                         if (ret) {
1281                                 /*
1282                                  * On real read error, finish. On end of data,
1283                                  * set EOF flag and just exit the read loop.
1284                                  */
1285                                 if (handle->cur &&
1286                                     handle->cur->entries[handle->k]) {
1287                                         goto out_finish;
1288                                 } else {
1289                                         eof = 1;
1290                                         break;
1291                                 }
1292                         }
1293                         if (++ring >= ring_size)
1294                                 ring = 0;
1295                 }
1296                 asked += i;
1297                 want -= i;
1298
1299                 /*
1300                  * We are out of data, wait for some more.
1301                  */
1302                 if (!have) {
1303                         if (!asked)
1304                                 break;
1305
1306                         ret = hib_wait_io(&hb);
1307                         if (ret)
1308                                 goto out_finish;
1309                         have += asked;
1310                         asked = 0;
1311                         if (eof)
1312                                 eof = 2;
1313                 }
1314
1315                 if (crc->run_threads) {
1316                         wait_event(crc->done, atomic_read(&crc->stop));
1317                         atomic_set(&crc->stop, 0);
1318                         crc->run_threads = 0;
1319                 }
1320
1321                 for (thr = 0; have && thr < nr_threads; thr++) {
1322                         data[thr].cmp_len = *(size_t *)page[pg];
1323                         if (unlikely(!data[thr].cmp_len ||
1324                                      data[thr].cmp_len >
1325                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1326                                 printk(KERN_ERR
1327                                        "PM: Invalid LZO compressed length\n");
1328                                 ret = -1;
1329                                 goto out_finish;
1330                         }
1331
1332                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1333                                             PAGE_SIZE);
1334                         if (need > have) {
1335                                 if (eof > 1) {
1336                                         ret = -1;
1337                                         goto out_finish;
1338                                 }
1339                                 break;
1340                         }
1341
1342                         for (off = 0;
1343                              off < LZO_HEADER + data[thr].cmp_len;
1344                              off += PAGE_SIZE) {
1345                                 memcpy(data[thr].cmp + off,
1346                                        page[pg], PAGE_SIZE);
1347                                 have--;
1348                                 want++;
1349                                 if (++pg >= ring_size)
1350                                         pg = 0;
1351                         }
1352
1353                         atomic_set(&data[thr].ready, 1);
1354                         wake_up(&data[thr].go);
1355                 }
1356
1357                 /*
1358                  * Wait for more data while we are decompressing.
1359                  */
1360                 if (have < LZO_CMP_PAGES && asked) {
1361                         ret = hib_wait_io(&hb);
1362                         if (ret)
1363                                 goto out_finish;
1364                         have += asked;
1365                         asked = 0;
1366                         if (eof)
1367                                 eof = 2;
1368                 }
1369
1370                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1371                         wait_event(data[thr].done,
1372                                    atomic_read(&data[thr].stop));
1373                         atomic_set(&data[thr].stop, 0);
1374
1375                         ret = data[thr].ret;
1376
1377                         if (ret < 0) {
1378                                 printk(KERN_ERR
1379                                        "PM: LZO decompression failed\n");
1380                                 goto out_finish;
1381                         }
1382
1383                         if (unlikely(!data[thr].unc_len ||
1384                                      data[thr].unc_len > LZO_UNC_SIZE ||
1385                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1386                                 printk(KERN_ERR
1387                                        "PM: Invalid LZO uncompressed length\n");
1388                                 ret = -1;
1389                                 goto out_finish;
1390                         }
1391
1392                         for (off = 0;
1393                              off < data[thr].unc_len; off += PAGE_SIZE) {
1394                                 memcpy(data_of(*snapshot),
1395                                        data[thr].unc + off, PAGE_SIZE);
1396
1397                                 if (!(nr_pages % m))
1398                                         printk(KERN_INFO
1399                                                "PM: Image loading progress: "
1400                                                "%3d%%\n",
1401                                                nr_pages / m * 10);
1402                                 nr_pages++;
1403
1404                                 ret = snapshot_write_next(snapshot);
1405                                 if (ret <= 0) {
1406                                         crc->run_threads = thr + 1;
1407                                         atomic_set(&crc->ready, 1);
1408                                         wake_up(&crc->go);
1409                                         goto out_finish;
1410                                 }
1411                         }
1412                 }
1413
1414                 crc->run_threads = thr;
1415                 atomic_set(&crc->ready, 1);
1416                 wake_up(&crc->go);
1417         }
1418
1419 out_finish:
1420         if (crc->run_threads) {
1421                 wait_event(crc->done, atomic_read(&crc->stop));
1422                 atomic_set(&crc->stop, 0);
1423         }
1424         stop = ktime_get();
1425         if (!ret) {
1426                 printk(KERN_INFO "PM: Image loading done.\n");
1427                 snapshot_write_finalize(snapshot);
1428                 if (!snapshot_image_loaded(snapshot))
1429                         ret = -ENODATA;
1430                 if (!ret) {
1431                         if (swsusp_header->flags & SF_CRC32_MODE) {
1432                                 if(handle->crc32 != swsusp_header->crc32) {
1433                                         printk(KERN_ERR
1434                                                "PM: Invalid image CRC32!\n");
1435                                         ret = -ENODATA;
1436                                 }
1437                         }
1438                 }
1439         }
1440         swsusp_show_speed(start, stop, nr_to_read, "Read");
1441 out_clean:
1442         for (i = 0; i < ring_size; i++)
1443                 free_page((unsigned long)page[i]);
1444         if (crc) {
1445                 if (crc->thr)
1446                         kthread_stop(crc->thr);
1447                 kfree(crc);
1448         }
1449         if (data) {
1450                 for (thr = 0; thr < nr_threads; thr++)
1451                         if (data[thr].thr)
1452                                 kthread_stop(data[thr].thr);
1453                 vfree(data);
1454         }
1455         vfree(page);
1456
1457         return ret;
1458 }
1459
1460 /**
1461  *      swsusp_read - read the hibernation image.
1462  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1463  *                be written into this memory location
1464  */
1465
1466 int swsusp_read(unsigned int *flags_p)
1467 {
1468         int error;
1469         struct swap_map_handle handle;
1470         struct snapshot_handle snapshot;
1471         struct swsusp_info *header;
1472
1473         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1474         error = snapshot_write_next(&snapshot);
1475         if (error < PAGE_SIZE)
1476                 return error < 0 ? error : -EFAULT;
1477         header = (struct swsusp_info *)data_of(snapshot);
1478         error = get_swap_reader(&handle, flags_p);
1479         if (error)
1480                 goto end;
1481         if (!error)
1482                 error = swap_read_page(&handle, header, NULL);
1483         if (!error) {
1484                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1485                         load_image(&handle, &snapshot, header->pages - 1) :
1486                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1487         }
1488         swap_reader_finish(&handle);
1489 end:
1490         if (!error)
1491                 pr_debug("PM: Image successfully loaded\n");
1492         else
1493                 pr_debug("PM: Error %d resuming\n", error);
1494         return error;
1495 }
1496
1497 /**
1498  *      swsusp_check - Check for swsusp signature in the resume device
1499  */
1500
1501 int swsusp_check(void)
1502 {
1503         int error;
1504
1505         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1506                                             FMODE_READ, NULL);
1507         if (!IS_ERR(hib_resume_bdev)) {
1508                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1509                 clear_page(swsusp_header);
1510                 error = hib_submit_io(READ_SYNC, swsusp_resume_block,
1511                                         swsusp_header, NULL);
1512                 if (error)
1513                         goto put;
1514
1515                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1516                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1517                         /* Reset swap signature now */
1518                         error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1519                                                 swsusp_header, NULL);
1520                 } else {
1521                         error = -EINVAL;
1522                 }
1523
1524 put:
1525                 if (error)
1526                         blkdev_put(hib_resume_bdev, FMODE_READ);
1527                 else
1528                         pr_debug("PM: Image signature found, resuming\n");
1529         } else {
1530                 error = PTR_ERR(hib_resume_bdev);
1531         }
1532
1533         if (error)
1534                 pr_debug("PM: Image not found (code %d)\n", error);
1535
1536         return error;
1537 }
1538
1539 /**
1540  *      swsusp_close - close swap device.
1541  */
1542
1543 void swsusp_close(fmode_t mode)
1544 {
1545         if (IS_ERR(hib_resume_bdev)) {
1546                 pr_debug("PM: Image device not initialised\n");
1547                 return;
1548         }
1549
1550         blkdev_put(hib_resume_bdev, mode);
1551 }
1552
1553 /**
1554  *      swsusp_unmark - Unmark swsusp signature in the resume device
1555  */
1556
1557 #ifdef CONFIG_SUSPEND
1558 int swsusp_unmark(void)
1559 {
1560         int error;
1561
1562         hib_submit_io(READ_SYNC, swsusp_resume_block, swsusp_header, NULL);
1563         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1564                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1565                 error = hib_submit_io(WRITE_SYNC, swsusp_resume_block,
1566                                         swsusp_header, NULL);
1567         } else {
1568                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1569                 error = -ENODEV;
1570         }
1571
1572         /*
1573          * We just returned from suspend, we don't need the image any more.
1574          */
1575         free_all_swap_pages(root_swap);
1576
1577         return error;
1578 }
1579 #endif
1580
1581 static int swsusp_header_init(void)
1582 {
1583         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1584         if (!swsusp_header)
1585                 panic("Could not allocate memory for swsusp_header\n");
1586         return 0;
1587 }
1588
1589 core_initcall(swsusp_header_init);