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  * When reading an {un,}compressed image, we may restore pages in place,
  41  * in which case some architectures need these pages cleaning before they
  42  * can be executed. We don't know which pages these may be, so clean the lot.
  43  */
  44 static bool clean_pages_on_read;
  45 static bool clean_pages_on_decompress;
  46
  47 /*
  48  *      The swap map is a data structure used for keeping track of each page
  49  *      written to a swap partition.  It consists of many swap_map_page
  50  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  51  *      These structures are stored on the swap and linked together with the
  52  *      help of the .next_swap member.
  53  *
  54  *      The swap map is created during suspend.  The swap map pages are
  55  *      allocated and populated one at a time, so we only need one memory
  56  *      page to set up the entire structure.
  57  *
  58  *      During resume we pick up all swap_map_page structures into a list.
  59  */
  60
  61 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  62
  63 /*
  64  * Number of free pages that are not high.
  65  */
  66 static inline unsigned long low_free_pages(void)
  67 {
  68         return nr_free_pages() - nr_free_highpages();
  69 }
  70
  71 /*
  72  * Number of pages required to be kept free while writing the image. Always
  73  * half of all available low pages before the writing starts.
  74  */
  75 static inline unsigned long reqd_free_pages(void)
  76 {
  77         return low_free_pages() / 2;
  78 }
  79
  80 struct swap_map_page {
  81         sector_t entries[MAP_PAGE_ENTRIES];
  82         sector_t next_swap;
  83 };
  84
  85 struct swap_map_page_list {
  86         struct swap_map_page *map;
  87         struct swap_map_page_list *next;
  88 };
  89
  90 /**
  91  *      The swap_map_handle structure is used for handling swap in
  92  *      a file-alike way
  93  */
  94
  95 struct swap_map_handle {
  96         struct swap_map_page *cur;
  97         struct swap_map_page_list *maps;
  98         sector_t cur_swap;
  99         sector_t first_sector;
 100         unsigned int k;
 101         unsigned long reqd_free_pages;
 102         u32 crc32;
 103 };
 104
 105 struct swsusp_header {
 106         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 107                       sizeof(u32)];
 108         u32     crc32;
 109         sector_t image;
 110         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 111         char    orig_sig[10];
 112         char    sig[10];
 113 } __packed;
 114
 115 static struct swsusp_header *swsusp_header;
 116
 117 /**
 118  *      The following functions are used for tracing the allocated
 119  *      swap pages, so that they can be freed in case of an error.
 120  */
 121
 122 struct swsusp_extent {
 123         struct rb_node node;
 124         unsigned long start;
 125         unsigned long end;
 126 };
 127
 128 static struct rb_root swsusp_extents = RB_ROOT;
 129
 130 static int swsusp_extents_insert(unsigned long swap_offset)
 131 {
 132         struct rb_node **new = &(swsusp_extents.rb_node);
 133         struct rb_node *parent = NULL;
 134         struct swsusp_extent *ext;
 135
 136         /* Figure out where to put the new node */
 137         while (*new) {
 138                 ext = rb_entry(*new, struct swsusp_extent, node);
 139                 parent = *new;
 140                 if (swap_offset < ext->start) {
 141                         /* Try to merge */
 142                         if (swap_offset == ext->start - 1) {
 143                                 ext->start--;
 144                                 return 0;
 145                         }
 146                         new = &((*new)->rb_left);
 147                 } else if (swap_offset > ext->end) {
 148                         /* Try to merge */
 149                         if (swap_offset == ext->end + 1) {
 150                                 ext->end++;
 151                                 return 0;
 152                         }
 153                         new = &((*new)->rb_right);
 154                 } else {
 155                         /* It already is in the tree */
 156                         return -EINVAL;
 157                 }
 158         }
 159         /* Add the new node and rebalance the tree. */
 160         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 161         if (!ext)
 162                 return -ENOMEM;
 163
 164         ext->start = swap_offset;
 165         ext->end = swap_offset;
 166         rb_link_node(&ext->node, parent, new);
 167         rb_insert_color(&ext->node, &swsusp_extents);
 168         return 0;
 169 }
 170
 171 /**
 172  *      alloc_swapdev_block - allocate a swap page and register that it has
 173  *      been allocated, so that it can be freed in case of an error.
 174  */
 175
 176 sector_t alloc_swapdev_block(int swap)
 177 {
 178         unsigned long offset;
 179
 180         offset = swp_offset(get_swap_page_of_type(swap));
 181         if (offset) {
 182                 if (swsusp_extents_insert(offset))
 183                         swap_free(swp_entry(swap, offset));
 184                 else
 185                         return swapdev_block(swap, offset);
 186         }
 187         return 0;
 188 }
 189
 190 /**
 191  *      free_all_swap_pages - free swap pages allocated for saving image data.
 192  *      It also frees the extents used to register which swap entries had been
 193  *      allocated.
 194  */
 195
 196 void free_all_swap_pages(int swap)
 197 {
 198         struct rb_node *node;
 199
 200         while ((node = swsusp_extents.rb_node)) {
 201                 struct swsusp_extent *ext;
 202                 unsigned long offset;
 203
 204                 ext = container_of(node, struct swsusp_extent, node);
 205                 rb_erase(node, &swsusp_extents);
 206                 for (offset = ext->start; offset <= ext->end; offset++)
 207                         swap_free(swp_entry(swap, offset));
 208
 209                 kfree(ext);
 210         }
 211 }
 212
 213 int swsusp_swap_in_use(void)
 214 {
 215         return (swsusp_extents.rb_node != NULL);
 216 }
 217
 218 /*
 219  * General things
 220  */
 221
 222 static unsigned short root_swap = 0xffff;
 223 static struct block_device *hib_resume_bdev;
 224
 225 struct hib_bio_batch {
 226         atomic_t                count;
 227         wait_queue_head_t       wait;
 228         int                     error;
 229 };
 230
 231 static void hib_init_batch(struct hib_bio_batch *hb)
 232 {
 233         atomic_set(&hb->count, 0);
 234         init_waitqueue_head(&hb->wait);
 235         hb->error = 0;
 236 }
 237
 238 static void hib_end_io(struct bio *bio)
 239 {
 240         struct hib_bio_batch *hb = bio->bi_private;
 241         struct page *page = bio->bi_io_vec[0].bv_page;
 242
 243         if (bio->bi_error) {
 244                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 245                                 imajor(bio->bi_bdev->bd_inode),
 246                                 iminor(bio->bi_bdev->bd_inode),
 247                                 (unsigned long long)bio->bi_iter.bi_sector);
 248         }
 249
 250         if (bio_data_dir(bio) == WRITE)
 251                 put_page(page);
 252         else if (clean_pages_on_read)
 253                 flush_icache_range((unsigned long)page_address(page),
 254                                    (unsigned long)page_address(page) + PAGE_SIZE);
 255
 256         if (bio->bi_error && !hb->error)
 257                 hb->error = bio->bi_error;
 258         if (atomic_dec_and_test(&hb->count))
 259                 wake_up(&hb->wait);
 260
 261         bio_put(bio);
 262 }
 263
 264 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 265                 struct hib_bio_batch *hb)
 266 {
 267         struct page *page = virt_to_page(addr);
 268         struct bio *bio;
 269         int error = 0;
 270
 271         bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
 272         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 273         bio->bi_bdev = hib_resume_bdev;
 274         bio_set_op_attrs(bio, op, op_flags);
 275
 276         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 277                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 278                         (unsigned long long)bio->bi_iter.bi_sector);
 279                 bio_put(bio);
 280                 return -EFAULT;
 281         }
 282
 283         if (hb) {
 284                 bio->bi_end_io = hib_end_io;
 285                 bio->bi_private = hb;
 286                 atomic_inc(&hb->count);
 287                 submit_bio(bio);
 288         } else {
 289                 error = submit_bio_wait(bio);
 290                 bio_put(bio);
 291         }
 292
 293         return error;
 294 }
 295
 296 static int hib_wait_io(struct hib_bio_batch *hb)
 297 {
 298         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 299         return hb->error;
 300 }
 301
 302 /*
 303  * Saving part
 304  */
 305
 306 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 307 {
 308         int error;
 309
 310         hib_submit_io(REQ_OP_READ, READ_SYNC, swsusp_resume_block,
 311                       swsusp_header, NULL);
 312         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 313             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 314                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 315                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 316                 swsusp_header->image = handle->first_sector;
 317                 swsusp_header->flags = flags;
 318                 if (flags & SF_CRC32_MODE)
 319                         swsusp_header->crc32 = handle->crc32;
 320                 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
 321                                       swsusp_resume_block, swsusp_header, NULL);
 322         } else {
 323                 printk(KERN_ERR "PM: Swap header not found!\n");
 324                 error = -ENODEV;
 325         }
 326         return error;
 327 }
 328
 329 /**
 330  *      swsusp_swap_check - check if the resume device is a swap device
 331  *      and get its index (if so)
 332  *
 333  *      This is called before saving image
 334  */
 335 static int swsusp_swap_check(void)
 336 {
 337         int res;
 338
 339         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 340                         &hib_resume_bdev);
 341         if (res < 0)
 342                 return res;
 343
 344         root_swap = res;
 345         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 346         if (res)
 347                 return res;
 348
 349         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 350         if (res < 0)
 351                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 352
 353         return res;
 354 }
 355
 356 /**
 357  *      write_page - Write one page to given swap location.
 358  *      @buf:           Address we're writing.
 359  *      @offset:        Offset of the swap page we're writing to.
 360  *      @hb:            bio completion batch
 361  */
 362
 363 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 364 {
 365         void *src;
 366         int ret;
 367
 368         if (!offset)
 369                 return -ENOSPC;
 370
 371         if (hb) {
 372                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 373                                               __GFP_NORETRY);
 374                 if (src) {
 375                         copy_page(src, buf);
 376                 } else {
 377                         ret = hib_wait_io(hb); /* Free pages */
 378                         if (ret)
 379                                 return ret;
 380                         src = (void *)__get_free_page(__GFP_RECLAIM |
 381                                                       __GFP_NOWARN |
 382                                                       __GFP_NORETRY);
 383                         if (src) {
 384                                 copy_page(src, buf);
 385                         } else {
 386                                 WARN_ON_ONCE(1);
 387                                 hb = NULL;      /* Go synchronous */
 388                                 src = buf;
 389                         }
 390                 }
 391         } else {
 392                 src = buf;
 393         }
 394         return hib_submit_io(REQ_OP_WRITE, WRITE_SYNC, offset, src, hb);
 395 }
 396
 397 static void release_swap_writer(struct swap_map_handle *handle)
 398 {
 399         if (handle->cur)
 400                 free_page((unsigned long)handle->cur);
 401         handle->cur = NULL;
 402 }
 403
 404 static int get_swap_writer(struct swap_map_handle *handle)
 405 {
 406         int ret;
 407
 408         ret = swsusp_swap_check();
 409         if (ret) {
 410                 if (ret != -ENOSPC)
 411                         printk(KERN_ERR "PM: Cannot find swap device, try "
 412                                         "swapon -a.\n");
 413                 return ret;
 414         }
 415         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 416         if (!handle->cur) {
 417                 ret = -ENOMEM;
 418                 goto err_close;
 419         }
 420         handle->cur_swap = alloc_swapdev_block(root_swap);
 421         if (!handle->cur_swap) {
 422                 ret = -ENOSPC;
 423                 goto err_rel;
 424         }
 425         handle->k = 0;
 426         handle->reqd_free_pages = reqd_free_pages();
 427         handle->first_sector = handle->cur_swap;
 428         return 0;
 429 err_rel:
 430         release_swap_writer(handle);
 431 err_close:
 432         swsusp_close(FMODE_WRITE);
 433         return ret;
 434 }
 435
 436 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 437                 struct hib_bio_batch *hb)
 438 {
 439         int error = 0;
 440         sector_t offset;
 441
 442         if (!handle->cur)
 443                 return -EINVAL;
 444         offset = alloc_swapdev_block(root_swap);
 445         error = write_page(buf, offset, hb);
 446         if (error)
 447                 return error;
 448         handle->cur->entries[handle->k++] = offset;
 449         if (handle->k >= MAP_PAGE_ENTRIES) {
 450                 offset = alloc_swapdev_block(root_swap);
 451                 if (!offset)
 452                         return -ENOSPC;
 453                 handle->cur->next_swap = offset;
 454                 error = write_page(handle->cur, handle->cur_swap, hb);
 455                 if (error)
 456                         goto out;
 457                 clear_page(handle->cur);
 458                 handle->cur_swap = offset;
 459                 handle->k = 0;
 460
 461                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 462                         error = hib_wait_io(hb);
 463                         if (error)
 464                                 goto out;
 465                         /*
 466                          * Recalculate the number of required free pages, to
 467                          * make sure we never take more than half.
 468                          */
 469                         handle->reqd_free_pages = reqd_free_pages();
 470                 }
 471         }
 472  out:
 473         return error;
 474 }
 475
 476 static int flush_swap_writer(struct swap_map_handle *handle)
 477 {
 478         if (handle->cur && handle->cur_swap)
 479                 return write_page(handle->cur, handle->cur_swap, NULL);
 480         else
 481                 return -EINVAL;
 482 }
 483
 484 static int swap_writer_finish(struct swap_map_handle *handle,
 485                 unsigned int flags, int error)
 486 {
 487         if (!error) {
 488                 flush_swap_writer(handle);
 489                 printk(KERN_INFO "PM: S");
 490                 error = mark_swapfiles(handle, flags);
 491                 printk("|\n");
 492         }
 493
 494         if (error)
 495                 free_all_swap_pages(root_swap);
 496         release_swap_writer(handle);
 497         swsusp_close(FMODE_WRITE);
 498
 499         return error;
 500 }
 501
 502 /* We need to remember how much compressed data we need to read. */
 503 #define LZO_HEADER      sizeof(size_t)
 504
 505 /* Number of pages/bytes we'll compress at one time. */
 506 #define LZO_UNC_PAGES   32
 507 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 508
 509 /* Number of pages/bytes we need for compressed data (worst case). */
 510 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 511                                      LZO_HEADER, PAGE_SIZE)
 512 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 513
 514 /* Maximum number of threads for compression/decompression. */
 515 #define LZO_THREADS     3
 516
 517 /* Minimum/maximum number of pages for read buffering. */
 518 #define LZO_MIN_RD_PAGES        1024
 519 #define LZO_MAX_RD_PAGES        8192
 520
 521
 522 /**
 523  *      save_image - save the suspend image data
 524  */
 525
 526 static int save_image(struct swap_map_handle *handle,
 527                       struct snapshot_handle *snapshot,
 528                       unsigned int nr_to_write)
 529 {
 530         unsigned int m;
 531         int ret;
 532         int nr_pages;
 533         int err2;
 534         struct hib_bio_batch hb;
 535         ktime_t start;
 536         ktime_t stop;
 537
 538         hib_init_batch(&hb);
 539
 540         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 541                 nr_to_write);
 542         m = nr_to_write / 10;
 543         if (!m)
 544                 m = 1;
 545         nr_pages = 0;
 546         start = ktime_get();
 547         while (1) {
 548                 ret = snapshot_read_next(snapshot);
 549                 if (ret <= 0)
 550                         break;
 551                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 552                 if (ret)
 553                         break;
 554                 if (!(nr_pages % m))
 555                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 556                                nr_pages / m * 10);
 557                 nr_pages++;
 558         }
 559         err2 = hib_wait_io(&hb);
 560         stop = ktime_get();
 561         if (!ret)
 562                 ret = err2;
 563         if (!ret)
 564                 printk(KERN_INFO "PM: Image saving done.\n");
 565         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 566         return ret;
 567 }
 568
 569 /**
 570  * Structure used for CRC32.
 571  */
 572 struct crc_data {
 573         struct task_struct *thr;                  /* thread */
 574         atomic_t ready;                           /* ready to start flag */
 575         atomic_t stop;                            /* ready to stop flag */
 576         unsigned run_threads;                     /* nr current threads */
 577         wait_queue_head_t go;                     /* start crc update */
 578         wait_queue_head_t done;                   /* crc update done */
 579         u32 *crc32;                               /* points to handle's crc32 */
 580         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 581         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 582 };
 583
 584 /**
 585  * CRC32 update function that runs in its own thread.
 586  */
 587 static int crc32_threadfn(void *data)
 588 {
 589         struct crc_data *d = data;
 590         unsigned i;
 591
 592         while (1) {
 593                 wait_event(d->go, atomic_read(&d->ready) ||
 594                                   kthread_should_stop());
 595                 if (kthread_should_stop()) {
 596                         d->thr = NULL;
 597                         atomic_set(&d->stop, 1);
 598                         wake_up(&d->done);
 599                         break;
 600                 }
 601                 atomic_set(&d->ready, 0);
 602
 603                 for (i = 0; i < d->run_threads; i++)
 604                         *d->crc32 = crc32_le(*d->crc32,
 605                                              d->unc[i], *d->unc_len[i]);
 606                 atomic_set(&d->stop, 1);
 607                 wake_up(&d->done);
 608         }
 609         return 0;
 610 }
 611 /**
 612  * Structure used for LZO data compression.
 613  */
 614 struct cmp_data {
 615         struct task_struct *thr;                  /* thread */
 616         atomic_t ready;                           /* ready to start flag */
 617         atomic_t stop;                            /* ready to stop flag */
 618         int ret;                                  /* return code */
 619         wait_queue_head_t go;                     /* start compression */
 620         wait_queue_head_t done;                   /* compression done */
 621         size_t unc_len;                           /* uncompressed length */
 622         size_t cmp_len;                           /* compressed length */
 623         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 624         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 625         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 626 };
 627
 628 /**
 629  * Compression function that runs in its own thread.
 630  */
 631 static int lzo_compress_threadfn(void *data)
 632 {
 633         struct cmp_data *d = data;
 634
 635         while (1) {
 636                 wait_event(d->go, atomic_read(&d->ready) ||
 637                                   kthread_should_stop());
 638                 if (kthread_should_stop()) {
 639                         d->thr = NULL;
 640                         d->ret = -1;
 641                         atomic_set(&d->stop, 1);
 642                         wake_up(&d->done);
 643                         break;
 644                 }
 645                 atomic_set(&d->ready, 0);
 646
 647                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 648                                           d->cmp + LZO_HEADER, &d->cmp_len,
 649                                           d->wrk);
 650                 atomic_set(&d->stop, 1);
 651                 wake_up(&d->done);
 652         }
 653         return 0;
 654 }
 655
 656 /**
 657  * save_image_lzo - Save the suspend image data compressed with LZO.
 658  * @handle: Swap map handle to use for saving the image.
 659  * @snapshot: Image to read data from.
 660  * @nr_to_write: Number of pages to save.
 661  */
 662 static int save_image_lzo(struct swap_map_handle *handle,
 663                           struct snapshot_handle *snapshot,
 664                           unsigned int nr_to_write)
 665 {
 666         unsigned int m;
 667         int ret = 0;
 668         int nr_pages;
 669         int err2;
 670         struct hib_bio_batch hb;
 671         ktime_t start;
 672         ktime_t stop;
 673         size_t off;
 674         unsigned thr, run_threads, nr_threads;
 675         unsigned char *page = NULL;
 676         struct cmp_data *data = NULL;
 677         struct crc_data *crc = NULL;
 678
 679         hib_init_batch(&hb);
 680
 681         /*
 682          * We'll limit the number of threads for compression to limit memory
 683          * footprint.
 684          */
 685         nr_threads = num_online_cpus() - 1;
 686         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 687
 688         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 689         if (!page) {
 690                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 691                 ret = -ENOMEM;
 692                 goto out_clean;
 693         }
 694
 695         data = vmalloc(sizeof(*data) * nr_threads);
 696         if (!data) {
 697                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 698                 ret = -ENOMEM;
 699                 goto out_clean;
 700         }
 701         for (thr = 0; thr < nr_threads; thr++)
 702                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 703
 704         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 705         if (!crc) {
 706                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 707                 ret = -ENOMEM;
 708                 goto out_clean;
 709         }
 710         memset(crc, 0, offsetof(struct crc_data, go));
 711
 712         /*
 713          * Start the compression threads.
 714          */
 715         for (thr = 0; thr < nr_threads; thr++) {
 716                 init_waitqueue_head(&data[thr].go);
 717                 init_waitqueue_head(&data[thr].done);
 718
 719                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 720                                             &data[thr],
 721                                             "image_compress/%u", thr);
 722                 if (IS_ERR(data[thr].thr)) {
 723                         data[thr].thr = NULL;
 724                         printk(KERN_ERR
 725                                "PM: Cannot start compression threads\n");
 726                         ret = -ENOMEM;
 727                         goto out_clean;
 728                 }
 729         }
 730
 731         /*
 732          * Start the CRC32 thread.
 733          */
 734         init_waitqueue_head(&crc->go);
 735         init_waitqueue_head(&crc->done);
 736
 737         handle->crc32 = 0;
 738         crc->crc32 = &handle->crc32;
 739         for (thr = 0; thr < nr_threads; thr++) {
 740                 crc->unc[thr] = data[thr].unc;
 741                 crc->unc_len[thr] = &data[thr].unc_len;
 742         }
 743
 744         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 745         if (IS_ERR(crc->thr)) {
 746                 crc->thr = NULL;
 747                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 748                 ret = -ENOMEM;
 749                 goto out_clean;
 750         }
 751
 752         /*
 753          * Adjust the number of required free pages after all allocations have
 754          * been done. We don't want to run out of pages when writing.
 755          */
 756         handle->reqd_free_pages = reqd_free_pages();
 757
 758         printk(KERN_INFO
 759                 "PM: Using %u thread(s) for compression.\n"
 760                 "PM: Compressing and saving image data (%u pages)...\n",
 761                 nr_threads, nr_to_write);
 762         m = nr_to_write / 10;
 763         if (!m)
 764                 m = 1;
 765         nr_pages = 0;
 766         start = ktime_get();
 767         for (;;) {
 768                 for (thr = 0; thr < nr_threads; thr++) {
 769                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 770                                 ret = snapshot_read_next(snapshot);
 771                                 if (ret < 0)
 772                                         goto out_finish;
 773
 774                                 if (!ret)
 775                                         break;
 776
 777                                 memcpy(data[thr].unc + off,
 778                                        data_of(*snapshot), PAGE_SIZE);
 779
 780                                 if (!(nr_pages % m))
 781                                         printk(KERN_INFO
 782                                                "PM: Image saving progress: "
 783                                                "%3d%%\n",
 784                                                nr_pages / m * 10);
 785                                 nr_pages++;
 786                         }
 787                         if (!off)
 788                                 break;
 789
 790                         data[thr].unc_len = off;
 791
 792                         atomic_set(&data[thr].ready, 1);
 793                         wake_up(&data[thr].go);
 794                 }
 795
 796                 if (!thr)
 797                         break;
 798
 799                 crc->run_threads = thr;
 800                 atomic_set(&crc->ready, 1);
 801                 wake_up(&crc->go);
 802
 803                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 804                         wait_event(data[thr].done,
 805                                    atomic_read(&data[thr].stop));
 806                         atomic_set(&data[thr].stop, 0);
 807
 808                         ret = data[thr].ret;
 809
 810                         if (ret < 0) {
 811                                 printk(KERN_ERR "PM: LZO compression failed\n");
 812                                 goto out_finish;
 813                         }
 814
 815                         if (unlikely(!data[thr].cmp_len ||
 816                                      data[thr].cmp_len >
 817                                      lzo1x_worst_compress(data[thr].unc_len))) {
 818                                 printk(KERN_ERR
 819                                        "PM: Invalid LZO compressed length\n");
 820                                 ret = -1;
 821                                 goto out_finish;
 822                         }
 823
 824                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 825
 826                         /*
 827                          * Given we are writing one page at a time to disk, we
 828                          * copy that much from the buffer, although the last
 829                          * bit will likely be smaller than full page. This is
 830                          * OK - we saved the length of the compressed data, so
 831                          * any garbage at the end will be discarded when we
 832                          * read it.
 833                          */
 834                         for (off = 0;
 835                              off < LZO_HEADER + data[thr].cmp_len;
 836                              off += PAGE_SIZE) {
 837                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 838
 839                                 ret = swap_write_page(handle, page, &hb);
 840                                 if (ret)
 841                                         goto out_finish;
 842                         }
 843                 }
 844
 845                 wait_event(crc->done, atomic_read(&crc->stop));
 846                 atomic_set(&crc->stop, 0);
 847         }
 848
 849 out_finish:
 850         err2 = hib_wait_io(&hb);
 851         stop = ktime_get();
 852         if (!ret)
 853                 ret = err2;
 854         if (!ret)
 855                 printk(KERN_INFO "PM: Image saving done.\n");
 856         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 857 out_clean:
 858         if (crc) {
 859                 if (crc->thr)
 860                         kthread_stop(crc->thr);
 861                 kfree(crc);
 862         }
 863         if (data) {
 864                 for (thr = 0; thr < nr_threads; thr++)
 865                         if (data[thr].thr)
 866                                 kthread_stop(data[thr].thr);
 867                 vfree(data);
 868         }
 869         if (page) free_page((unsigned long)page);
 870
 871         return ret;
 872 }
 873
 874 /**
 875  *      enough_swap - Make sure we have enough swap to save the image.
 876  *
 877  *      Returns TRUE or FALSE after checking the total amount of swap
 878  *      space avaiable from the resume partition.
 879  */
 880
 881 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 882 {
 883         unsigned int free_swap = count_swap_pages(root_swap, 1);
 884         unsigned int required;
 885
 886         pr_debug("PM: Free swap pages: %u\n", free_swap);
 887
 888         required = PAGES_FOR_IO + nr_pages;
 889         return free_swap > required;
 890 }
 891
 892 /**
 893  *      swsusp_write - Write entire image and metadata.
 894  *      @flags: flags to pass to the "boot" kernel in the image header
 895  *
 896  *      It is important _NOT_ to umount filesystems at this point. We want
 897  *      them synced (in case something goes wrong) but we DO not want to mark
 898  *      filesystem clean: it is not. (And it does not matter, if we resume
 899  *      correctly, we'll mark system clean, anyway.)
 900  */
 901
 902 int swsusp_write(unsigned int flags)
 903 {
 904         struct swap_map_handle handle;
 905         struct snapshot_handle snapshot;
 906         struct swsusp_info *header;
 907         unsigned long pages;
 908         int error;
 909
 910         pages = snapshot_get_image_size();
 911         error = get_swap_writer(&handle);
 912         if (error) {
 913                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 914                 return error;
 915         }
 916         if (flags & SF_NOCOMPRESS_MODE) {
 917                 if (!enough_swap(pages, flags)) {
 918                         printk(KERN_ERR "PM: Not enough free swap\n");
 919                         error = -ENOSPC;
 920                         goto out_finish;
 921                 }
 922         }
 923         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 924         error = snapshot_read_next(&snapshot);
 925         if (error < PAGE_SIZE) {
 926                 if (error >= 0)
 927                         error = -EFAULT;
 928
 929                 goto out_finish;
 930         }
 931         header = (struct swsusp_info *)data_of(snapshot);
 932         error = swap_write_page(&handle, header, NULL);
 933         if (!error) {
 934                 error = (flags & SF_NOCOMPRESS_MODE) ?
 935                         save_image(&handle, &snapshot, pages - 1) :
 936                         save_image_lzo(&handle, &snapshot, pages - 1);
 937         }
 938 out_finish:
 939         error = swap_writer_finish(&handle, flags, error);
 940         return error;
 941 }
 942
 943 /**
 944  *      The following functions allow us to read data using a swap map
 945  *      in a file-alike way
 946  */
 947
 948 static void release_swap_reader(struct swap_map_handle *handle)
 949 {
 950         struct swap_map_page_list *tmp;
 951
 952         while (handle->maps) {
 953                 if (handle->maps->map)
 954                         free_page((unsigned long)handle->maps->map);
 955                 tmp = handle->maps;
 956                 handle->maps = handle->maps->next;
 957                 kfree(tmp);
 958         }
 959         handle->cur = NULL;
 960 }
 961
 962 static int get_swap_reader(struct swap_map_handle *handle,
 963                 unsigned int *flags_p)
 964 {
 965         int error;
 966         struct swap_map_page_list *tmp, *last;
 967         sector_t offset;
 968
 969         *flags_p = swsusp_header->flags;
 970
 971         if (!swsusp_header->image) /* how can this happen? */
 972                 return -EINVAL;
 973
 974         handle->cur = NULL;
 975         last = handle->maps = NULL;
 976         offset = swsusp_header->image;
 977         while (offset) {
 978                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 979                 if (!tmp) {
 980                         release_swap_reader(handle);
 981                         return -ENOMEM;
 982                 }
 983                 memset(tmp, 0, sizeof(*tmp));
 984                 if (!handle->maps)
 985                         handle->maps = tmp;
 986                 if (last)
 987                         last->next = tmp;
 988                 last = tmp;
 989
 990                 tmp->map = (struct swap_map_page *)
 991                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 992                 if (!tmp->map) {
 993                         release_swap_reader(handle);
 994                         return -ENOMEM;
 995                 }
 996
 997                 error = hib_submit_io(REQ_OP_READ, READ_SYNC, offset,
 998                                       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(REQ_OP_READ, 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         ktime_t start;
1059         ktime_t 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         start = ktime_get();
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         stop = ktime_get();
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         ktime_t start;
1167         ktime_t 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_RECLAIM | __GFP_HIGH :
1267                                                   __GFP_RECLAIM | __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         start = ktime_get();
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         stop = ktime_get();
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         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(REQ_OP_READ, READ_SYNC,
1532                                         swsusp_resume_block,
1533                                         swsusp_header, NULL);
1534                 if (error)
1535                         goto put;
1536
1537                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1538                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1539                         /* Reset swap signature now */
1540                         error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
1541                                                 swsusp_resume_block,
1542                                                 swsusp_header, NULL);
1543                 } else {
1544                         error = -EINVAL;
1545                 }
1546
1547 put:
1548                 if (error)
1549                         blkdev_put(hib_resume_bdev, FMODE_READ);
1550                 else
1551                         pr_debug("PM: Image signature found, resuming\n");
1552         } else {
1553                 error = PTR_ERR(hib_resume_bdev);
1554         }
1555
1556         if (error)
1557                 pr_debug("PM: Image not found (code %d)\n", error);
1558
1559         return error;
1560 }
1561
1562 /**
1563  *      swsusp_close - close swap device.
1564  */
1565
1566 void swsusp_close(fmode_t mode)
1567 {
1568         if (IS_ERR(hib_resume_bdev)) {
1569                 pr_debug("PM: Image device not initialised\n");
1570                 return;
1571         }
1572
1573         blkdev_put(hib_resume_bdev, mode);
1574 }
1575
1576 /**
1577  *      swsusp_unmark - Unmark swsusp signature in the resume device
1578  */
1579
1580 #ifdef CONFIG_SUSPEND
1581 int swsusp_unmark(void)
1582 {
1583         int error;
1584
1585         hib_submit_io(REQ_OP_READ, READ_SYNC, swsusp_resume_block,
1586                       swsusp_header, NULL);
1587         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1588                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1589                 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
1590                                         swsusp_resume_block,
1591                                         swsusp_header, NULL);
1592         } else {
1593                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1594                 error = -ENODEV;
1595         }
1596
1597         /*
1598          * We just returned from suspend, we don't need the image any more.
1599          */
1600         free_all_swap_pages(root_swap);
1601
1602         return error;
1603 }
1604 #endif
1605
1606 static int swsusp_header_init(void)
1607 {
1608         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1609         if (!swsusp_header)
1610                 panic("Could not allocate memory for swsusp_header\n");
1611         return 0;
1612 }
1613
1614 core_initcall(swsusp_header_init);