kernel/power/swap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/kernel/power/swap.c
   4  *
   5  * This file provides functions for reading the suspend image from
   6  * and writing it to a swap partition.
   7  *
   8  * Copyright (C) 1998,2001-2005 Pavel Machek <[email protected]>
   9  * Copyright (C) 2006 Rafael J. Wysocki <[email protected]>
  10  * Copyright (C) 2010-2012 Bojan Smojver <[email protected]>
  11  */
  12
  13 #define pr_fmt(fmt) "PM: " fmt
  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 = rb_entry(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         blk_status_t            error;
 229         struct blk_plug         plug;
 230 };
 231
 232 static void hib_init_batch(struct hib_bio_batch *hb)
 233 {
 234         atomic_set(&hb->count, 0);
 235         init_waitqueue_head(&hb->wait);
 236         hb->error = BLK_STS_OK;
 237         blk_start_plug(&hb->plug);
 238 }
 239
 240 static void hib_finish_batch(struct hib_bio_batch *hb)
 241 {
 242         blk_finish_plug(&hb->plug);
 243 }
 244
 245 static void hib_end_io(struct bio *bio)
 246 {
 247         struct hib_bio_batch *hb = bio->bi_private;
 248         struct page *page = bio_first_page_all(bio);
 249
 250         if (bio->bi_status) {
 251                 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
 252                          MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 253                          (unsigned long long)bio->bi_iter.bi_sector);
 254         }
 255
 256         if (bio_data_dir(bio) == WRITE)
 257                 put_page(page);
 258         else if (clean_pages_on_read)
 259                 flush_icache_range((unsigned long)page_address(page),
 260                                    (unsigned long)page_address(page) + PAGE_SIZE);
 261
 262         if (bio->bi_status && !hb->error)
 263                 hb->error = bio->bi_status;
 264         if (atomic_dec_and_test(&hb->count))
 265                 wake_up(&hb->wait);
 266
 267         bio_put(bio);
 268 }
 269
 270 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 271                 struct hib_bio_batch *hb)
 272 {
 273         struct page *page = virt_to_page(addr);
 274         struct bio *bio;
 275         int error = 0;
 276
 277         bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
 278         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 279         bio_set_dev(bio, hib_resume_bdev);
 280         bio_set_op_attrs(bio, op, op_flags);
 281
 282         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 283                 pr_err("Adding page to bio failed at %llu\n",
 284                        (unsigned long long)bio->bi_iter.bi_sector);
 285                 bio_put(bio);
 286                 return -EFAULT;
 287         }
 288
 289         if (hb) {
 290                 bio->bi_end_io = hib_end_io;
 291                 bio->bi_private = hb;
 292                 atomic_inc(&hb->count);
 293                 submit_bio(bio);
 294         } else {
 295                 error = submit_bio_wait(bio);
 296                 bio_put(bio);
 297         }
 298
 299         return error;
 300 }
 301
 302 static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
 303 {
 304         /*
 305          * We are relying on the behavior of blk_plug that a thread with
 306          * a plug will flush the plug list before sleeping.
 307          */
 308         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 309         return blk_status_to_errno(hb->error);
 310 }
 311
 312 /*
 313  * Saving part
 314  */
 315
 316 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 317 {
 318         int error;
 319
 320         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
 321                       swsusp_header, NULL);
 322         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 323             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 324                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 325                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 326                 swsusp_header->image = handle->first_sector;
 327                 swsusp_header->flags = flags;
 328                 if (flags & SF_CRC32_MODE)
 329                         swsusp_header->crc32 = handle->crc32;
 330                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
 331                                       swsusp_resume_block, swsusp_header, NULL);
 332         } else {
 333                 pr_err("Swap header not found!\n");
 334                 error = -ENODEV;
 335         }
 336         return error;
 337 }
 338
 339 /**
 340  *      swsusp_swap_check - check if the resume device is a swap device
 341  *      and get its index (if so)
 342  *
 343  *      This is called before saving image
 344  */
 345 static int swsusp_swap_check(void)
 346 {
 347         int res;
 348
 349         if (swsusp_resume_device)
 350                 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
 351         else
 352                 res = find_first_swap(&swsusp_resume_device);
 353         if (res < 0)
 354                 return res;
 355         root_swap = res;
 356
 357         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device, FMODE_WRITE,
 358                         NULL);
 359         if (IS_ERR(hib_resume_bdev))
 360                 return PTR_ERR(hib_resume_bdev);
 361
 362         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 363         if (res < 0)
 364                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 365
 366         return res;
 367 }
 368
 369 /**
 370  *      write_page - Write one page to given swap location.
 371  *      @buf:           Address we're writing.
 372  *      @offset:        Offset of the swap page we're writing to.
 373  *      @hb:            bio completion batch
 374  */
 375
 376 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 377 {
 378         void *src;
 379         int ret;
 380
 381         if (!offset)
 382                 return -ENOSPC;
 383
 384         if (hb) {
 385                 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 386                                               __GFP_NORETRY);
 387                 if (src) {
 388                         copy_page(src, buf);
 389                 } else {
 390                         ret = hib_wait_io(hb); /* Free pages */
 391                         if (ret)
 392                                 return ret;
 393                         src = (void *)__get_free_page(GFP_NOIO |
 394                                                       __GFP_NOWARN |
 395                                                       __GFP_NORETRY);
 396                         if (src) {
 397                                 copy_page(src, buf);
 398                         } else {
 399                                 WARN_ON_ONCE(1);
 400                                 hb = NULL;      /* Go synchronous */
 401                                 src = buf;
 402                         }
 403                 }
 404         } else {
 405                 src = buf;
 406         }
 407         return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
 408 }
 409
 410 static void release_swap_writer(struct swap_map_handle *handle)
 411 {
 412         if (handle->cur)
 413                 free_page((unsigned long)handle->cur);
 414         handle->cur = NULL;
 415 }
 416
 417 static int get_swap_writer(struct swap_map_handle *handle)
 418 {
 419         int ret;
 420
 421         ret = swsusp_swap_check();
 422         if (ret) {
 423                 if (ret != -ENOSPC)
 424                         pr_err("Cannot find swap device, try swapon -a\n");
 425                 return ret;
 426         }
 427         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 428         if (!handle->cur) {
 429                 ret = -ENOMEM;
 430                 goto err_close;
 431         }
 432         handle->cur_swap = alloc_swapdev_block(root_swap);
 433         if (!handle->cur_swap) {
 434                 ret = -ENOSPC;
 435                 goto err_rel;
 436         }
 437         handle->k = 0;
 438         handle->reqd_free_pages = reqd_free_pages();
 439         handle->first_sector = handle->cur_swap;
 440         return 0;
 441 err_rel:
 442         release_swap_writer(handle);
 443 err_close:
 444         swsusp_close(FMODE_WRITE);
 445         return ret;
 446 }
 447
 448 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 449                 struct hib_bio_batch *hb)
 450 {
 451         int error = 0;
 452         sector_t offset;
 453
 454         if (!handle->cur)
 455                 return -EINVAL;
 456         offset = alloc_swapdev_block(root_swap);
 457         error = write_page(buf, offset, hb);
 458         if (error)
 459                 return error;
 460         handle->cur->entries[handle->k++] = offset;
 461         if (handle->k >= MAP_PAGE_ENTRIES) {
 462                 offset = alloc_swapdev_block(root_swap);
 463                 if (!offset)
 464                         return -ENOSPC;
 465                 handle->cur->next_swap = offset;
 466                 error = write_page(handle->cur, handle->cur_swap, hb);
 467                 if (error)
 468                         goto out;
 469                 clear_page(handle->cur);
 470                 handle->cur_swap = offset;
 471                 handle->k = 0;
 472
 473                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 474                         error = hib_wait_io(hb);
 475                         if (error)
 476                                 goto out;
 477                         /*
 478                          * Recalculate the number of required free pages, to
 479                          * make sure we never take more than half.
 480                          */
 481                         handle->reqd_free_pages = reqd_free_pages();
 482                 }
 483         }
 484  out:
 485         return error;
 486 }
 487
 488 static int flush_swap_writer(struct swap_map_handle *handle)
 489 {
 490         if (handle->cur && handle->cur_swap)
 491                 return write_page(handle->cur, handle->cur_swap, NULL);
 492         else
 493                 return -EINVAL;
 494 }
 495
 496 static int swap_writer_finish(struct swap_map_handle *handle,
 497                 unsigned int flags, int error)
 498 {
 499         if (!error) {
 500                 flush_swap_writer(handle);
 501                 pr_info("S");
 502                 error = mark_swapfiles(handle, flags);
 503                 pr_cont("|\n");
 504         }
 505
 506         if (error)
 507                 free_all_swap_pages(root_swap);
 508         release_swap_writer(handle);
 509         swsusp_close(FMODE_WRITE);
 510
 511         return error;
 512 }
 513
 514 /* We need to remember how much compressed data we need to read. */
 515 #define LZO_HEADER      sizeof(size_t)
 516
 517 /* Number of pages/bytes we'll compress at one time. */
 518 #define LZO_UNC_PAGES   32
 519 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 520
 521 /* Number of pages/bytes we need for compressed data (worst case). */
 522 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 523                                      LZO_HEADER, PAGE_SIZE)
 524 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 525
 526 /* Maximum number of threads for compression/decompression. */
 527 #define LZO_THREADS     3
 528
 529 /* Minimum/maximum number of pages for read buffering. */
 530 #define LZO_MIN_RD_PAGES        1024
 531 #define LZO_MAX_RD_PAGES        8192
 532
 533
 534 /**
 535  *      save_image - save the suspend image data
 536  */
 537
 538 static int save_image(struct swap_map_handle *handle,
 539                       struct snapshot_handle *snapshot,
 540                       unsigned int nr_to_write)
 541 {
 542         unsigned int m;
 543         int ret;
 544         int nr_pages;
 545         int err2;
 546         struct hib_bio_batch hb;
 547         ktime_t start;
 548         ktime_t stop;
 549
 550         hib_init_batch(&hb);
 551
 552         pr_info("Saving image data pages (%u pages)...\n",
 553                 nr_to_write);
 554         m = nr_to_write / 10;
 555         if (!m)
 556                 m = 1;
 557         nr_pages = 0;
 558         start = ktime_get();
 559         while (1) {
 560                 ret = snapshot_read_next(snapshot);
 561                 if (ret <= 0)
 562                         break;
 563                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 564                 if (ret)
 565                         break;
 566                 if (!(nr_pages % m))
 567                         pr_info("Image saving progress: %3d%%\n",
 568                                 nr_pages / m * 10);
 569                 nr_pages++;
 570         }
 571         err2 = hib_wait_io(&hb);
 572         hib_finish_batch(&hb);
 573         stop = ktime_get();
 574         if (!ret)
 575                 ret = err2;
 576         if (!ret)
 577                 pr_info("Image saving done\n");
 578         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 579         return ret;
 580 }
 581
 582 /**
 583  * Structure used for CRC32.
 584  */
 585 struct crc_data {
 586         struct task_struct *thr;                  /* thread */
 587         atomic_t ready;                           /* ready to start flag */
 588         atomic_t stop;                            /* ready to stop flag */
 589         unsigned run_threads;                     /* nr current threads */
 590         wait_queue_head_t go;                     /* start crc update */
 591         wait_queue_head_t done;                   /* crc update done */
 592         u32 *crc32;                               /* points to handle's crc32 */
 593         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 594         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 595 };
 596
 597 /**
 598  * CRC32 update function that runs in its own thread.
 599  */
 600 static int crc32_threadfn(void *data)
 601 {
 602         struct crc_data *d = data;
 603         unsigned i;
 604
 605         while (1) {
 606                 wait_event(d->go, atomic_read(&d->ready) ||
 607                                   kthread_should_stop());
 608                 if (kthread_should_stop()) {
 609                         d->thr = NULL;
 610                         atomic_set(&d->stop, 1);
 611                         wake_up(&d->done);
 612                         break;
 613                 }
 614                 atomic_set(&d->ready, 0);
 615
 616                 for (i = 0; i < d->run_threads; i++)
 617                         *d->crc32 = crc32_le(*d->crc32,
 618                                              d->unc[i], *d->unc_len[i]);
 619                 atomic_set(&d->stop, 1);
 620                 wake_up(&d->done);
 621         }
 622         return 0;
 623 }
 624 /**
 625  * Structure used for LZO data compression.
 626  */
 627 struct cmp_data {
 628         struct task_struct *thr;                  /* thread */
 629         atomic_t ready;                           /* ready to start flag */
 630         atomic_t stop;                            /* ready to stop flag */
 631         int ret;                                  /* return code */
 632         wait_queue_head_t go;                     /* start compression */
 633         wait_queue_head_t done;                   /* compression done */
 634         size_t unc_len;                           /* uncompressed length */
 635         size_t cmp_len;                           /* compressed length */
 636         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 637         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 638         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 639 };
 640
 641 /**
 642  * Compression function that runs in its own thread.
 643  */
 644 static int lzo_compress_threadfn(void *data)
 645 {
 646         struct cmp_data *d = data;
 647
 648         while (1) {
 649                 wait_event(d->go, atomic_read(&d->ready) ||
 650                                   kthread_should_stop());
 651                 if (kthread_should_stop()) {
 652                         d->thr = NULL;
 653                         d->ret = -1;
 654                         atomic_set(&d->stop, 1);
 655                         wake_up(&d->done);
 656                         break;
 657                 }
 658                 atomic_set(&d->ready, 0);
 659
 660                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 661                                           d->cmp + LZO_HEADER, &d->cmp_len,
 662                                           d->wrk);
 663                 atomic_set(&d->stop, 1);
 664                 wake_up(&d->done);
 665         }
 666         return 0;
 667 }
 668
 669 /**
 670  * save_image_lzo - Save the suspend image data compressed with LZO.
 671  * @handle: Swap map handle to use for saving the image.
 672  * @snapshot: Image to read data from.
 673  * @nr_to_write: Number of pages to save.
 674  */
 675 static int save_image_lzo(struct swap_map_handle *handle,
 676                           struct snapshot_handle *snapshot,
 677                           unsigned int nr_to_write)
 678 {
 679         unsigned int m;
 680         int ret = 0;
 681         int nr_pages;
 682         int err2;
 683         struct hib_bio_batch hb;
 684         ktime_t start;
 685         ktime_t stop;
 686         size_t off;
 687         unsigned thr, run_threads, nr_threads;
 688         unsigned char *page = NULL;
 689         struct cmp_data *data = NULL;
 690         struct crc_data *crc = NULL;
 691
 692         hib_init_batch(&hb);
 693
 694         /*
 695          * We'll limit the number of threads for compression to limit memory
 696          * footprint.
 697          */
 698         nr_threads = num_online_cpus() - 1;
 699         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 700
 701         page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 702         if (!page) {
 703                 pr_err("Failed to allocate LZO page\n");
 704                 ret = -ENOMEM;
 705                 goto out_clean;
 706         }
 707
 708         data = vmalloc(array_size(nr_threads, sizeof(*data)));
 709         if (!data) {
 710                 pr_err("Failed to allocate LZO data\n");
 711                 ret = -ENOMEM;
 712                 goto out_clean;
 713         }
 714         for (thr = 0; thr < nr_threads; thr++)
 715                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 716
 717         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 718         if (!crc) {
 719                 pr_err("Failed to allocate crc\n");
 720                 ret = -ENOMEM;
 721                 goto out_clean;
 722         }
 723         memset(crc, 0, offsetof(struct crc_data, go));
 724
 725         /*
 726          * Start the compression threads.
 727          */
 728         for (thr = 0; thr < nr_threads; thr++) {
 729                 init_waitqueue_head(&data[thr].go);
 730                 init_waitqueue_head(&data[thr].done);
 731
 732                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 733                                             &data[thr],
 734                                             "image_compress/%u", thr);
 735                 if (IS_ERR(data[thr].thr)) {
 736                         data[thr].thr = NULL;
 737                         pr_err("Cannot start compression threads\n");
 738                         ret = -ENOMEM;
 739                         goto out_clean;
 740                 }
 741         }
 742
 743         /*
 744          * Start the CRC32 thread.
 745          */
 746         init_waitqueue_head(&crc->go);
 747         init_waitqueue_head(&crc->done);
 748
 749         handle->crc32 = 0;
 750         crc->crc32 = &handle->crc32;
 751         for (thr = 0; thr < nr_threads; thr++) {
 752                 crc->unc[thr] = data[thr].unc;
 753                 crc->unc_len[thr] = &data[thr].unc_len;
 754         }
 755
 756         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 757         if (IS_ERR(crc->thr)) {
 758                 crc->thr = NULL;
 759                 pr_err("Cannot start CRC32 thread\n");
 760                 ret = -ENOMEM;
 761                 goto out_clean;
 762         }
 763
 764         /*
 765          * Adjust the number of required free pages after all allocations have
 766          * been done. We don't want to run out of pages when writing.
 767          */
 768         handle->reqd_free_pages = reqd_free_pages();
 769
 770         pr_info("Using %u thread(s) for compression\n", nr_threads);
 771         pr_info("Compressing and saving image data (%u pages)...\n",
 772                 nr_to_write);
 773         m = nr_to_write / 10;
 774         if (!m)
 775                 m = 1;
 776         nr_pages = 0;
 777         start = ktime_get();
 778         for (;;) {
 779                 for (thr = 0; thr < nr_threads; thr++) {
 780                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 781                                 ret = snapshot_read_next(snapshot);
 782                                 if (ret < 0)
 783                                         goto out_finish;
 784
 785                                 if (!ret)
 786                                         break;
 787
 788                                 memcpy(data[thr].unc + off,
 789                                        data_of(*snapshot), PAGE_SIZE);
 790
 791                                 if (!(nr_pages % m))
 792                                         pr_info("Image saving progress: %3d%%\n",
 793                                                 nr_pages / m * 10);
 794                                 nr_pages++;
 795                         }
 796                         if (!off)
 797                                 break;
 798
 799                         data[thr].unc_len = off;
 800
 801                         atomic_set(&data[thr].ready, 1);
 802                         wake_up(&data[thr].go);
 803                 }
 804
 805                 if (!thr)
 806                         break;
 807
 808                 crc->run_threads = thr;
 809                 atomic_set(&crc->ready, 1);
 810                 wake_up(&crc->go);
 811
 812                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 813                         wait_event(data[thr].done,
 814                                    atomic_read(&data[thr].stop));
 815                         atomic_set(&data[thr].stop, 0);
 816
 817                         ret = data[thr].ret;
 818
 819                         if (ret < 0) {
 820                                 pr_err("LZO compression failed\n");
 821                                 goto out_finish;
 822                         }
 823
 824                         if (unlikely(!data[thr].cmp_len ||
 825                                      data[thr].cmp_len >
 826                                      lzo1x_worst_compress(data[thr].unc_len))) {
 827                                 pr_err("Invalid LZO compressed length\n");
 828                                 ret = -1;
 829                                 goto out_finish;
 830                         }
 831
 832                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 833
 834                         /*
 835                          * Given we are writing one page at a time to disk, we
 836                          * copy that much from the buffer, although the last
 837                          * bit will likely be smaller than full page. This is
 838                          * OK - we saved the length of the compressed data, so
 839                          * any garbage at the end will be discarded when we
 840                          * read it.
 841                          */
 842                         for (off = 0;
 843                              off < LZO_HEADER + data[thr].cmp_len;
 844                              off += PAGE_SIZE) {
 845                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 846
 847                                 ret = swap_write_page(handle, page, &hb);
 848                                 if (ret)
 849                                         goto out_finish;
 850                         }
 851                 }
 852
 853                 wait_event(crc->done, atomic_read(&crc->stop));
 854                 atomic_set(&crc->stop, 0);
 855         }
 856
 857 out_finish:
 858         err2 = hib_wait_io(&hb);
 859         stop = ktime_get();
 860         if (!ret)
 861                 ret = err2;
 862         if (!ret)
 863                 pr_info("Image saving done\n");
 864         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 865 out_clean:
 866         hib_finish_batch(&hb);
 867         if (crc) {
 868                 if (crc->thr)
 869                         kthread_stop(crc->thr);
 870                 kfree(crc);
 871         }
 872         if (data) {
 873                 for (thr = 0; thr < nr_threads; thr++)
 874                         if (data[thr].thr)
 875                                 kthread_stop(data[thr].thr);
 876                 vfree(data);
 877         }
 878         if (page) free_page((unsigned long)page);
 879
 880         return ret;
 881 }
 882
 883 /**
 884  *      enough_swap - Make sure we have enough swap to save the image.
 885  *
 886  *      Returns TRUE or FALSE after checking the total amount of swap
 887  *      space avaiable from the resume partition.
 888  */
 889
 890 static int enough_swap(unsigned int nr_pages)
 891 {
 892         unsigned int free_swap = count_swap_pages(root_swap, 1);
 893         unsigned int required;
 894
 895         pr_debug("Free swap pages: %u\n", free_swap);
 896
 897         required = PAGES_FOR_IO + nr_pages;
 898         return free_swap > required;
 899 }
 900
 901 /**
 902  *      swsusp_write - Write entire image and metadata.
 903  *      @flags: flags to pass to the "boot" kernel in the image header
 904  *
 905  *      It is important _NOT_ to umount filesystems at this point. We want
 906  *      them synced (in case something goes wrong) but we DO not want to mark
 907  *      filesystem clean: it is not. (And it does not matter, if we resume
 908  *      correctly, we'll mark system clean, anyway.)
 909  */
 910
 911 int swsusp_write(unsigned int flags)
 912 {
 913         struct swap_map_handle handle;
 914         struct snapshot_handle snapshot;
 915         struct swsusp_info *header;
 916         unsigned long pages;
 917         int error;
 918
 919         pages = snapshot_get_image_size();
 920         error = get_swap_writer(&handle);
 921         if (error) {
 922                 pr_err("Cannot get swap writer\n");
 923                 return error;
 924         }
 925         if (flags & SF_NOCOMPRESS_MODE) {
 926                 if (!enough_swap(pages)) {
 927                         pr_err("Not enough free swap\n");
 928                         error = -ENOSPC;
 929                         goto out_finish;
 930                 }
 931         }
 932         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 933         error = snapshot_read_next(&snapshot);
 934         if (error < (int)PAGE_SIZE) {
 935                 if (error >= 0)
 936                         error = -EFAULT;
 937
 938                 goto out_finish;
 939         }
 940         header = (struct swsusp_info *)data_of(snapshot);
 941         error = swap_write_page(&handle, header, NULL);
 942         if (!error) {
 943                 error = (flags & SF_NOCOMPRESS_MODE) ?
 944                         save_image(&handle, &snapshot, pages - 1) :
 945                         save_image_lzo(&handle, &snapshot, pages - 1);
 946         }
 947 out_finish:
 948         error = swap_writer_finish(&handle, flags, error);
 949         return error;
 950 }
 951
 952 /**
 953  *      The following functions allow us to read data using a swap map
 954  *      in a file-alike way
 955  */
 956
 957 static void release_swap_reader(struct swap_map_handle *handle)
 958 {
 959         struct swap_map_page_list *tmp;
 960
 961         while (handle->maps) {
 962                 if (handle->maps->map)
 963                         free_page((unsigned long)handle->maps->map);
 964                 tmp = handle->maps;
 965                 handle->maps = handle->maps->next;
 966                 kfree(tmp);
 967         }
 968         handle->cur = NULL;
 969 }
 970
 971 static int get_swap_reader(struct swap_map_handle *handle,
 972                 unsigned int *flags_p)
 973 {
 974         int error;
 975         struct swap_map_page_list *tmp, *last;
 976         sector_t offset;
 977
 978         *flags_p = swsusp_header->flags;
 979
 980         if (!swsusp_header->image) /* how can this happen? */
 981                 return -EINVAL;
 982
 983         handle->cur = NULL;
 984         last = handle->maps = NULL;
 985         offset = swsusp_header->image;
 986         while (offset) {
 987                 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
 988                 if (!tmp) {
 989                         release_swap_reader(handle);
 990                         return -ENOMEM;
 991                 }
 992                 if (!handle->maps)
 993                         handle->maps = tmp;
 994                 if (last)
 995                         last->next = tmp;
 996                 last = tmp;
 997
 998                 tmp->map = (struct swap_map_page *)
 999                            __get_free_page(GFP_NOIO | __GFP_HIGH);
1000                 if (!tmp->map) {
1001                         release_swap_reader(handle);
1002                         return -ENOMEM;
1003                 }
1004
1005                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1006                 if (error) {
1007                         release_swap_reader(handle);
1008                         return error;
1009                 }
1010                 offset = tmp->map->next_swap;
1011         }
1012         handle->k = 0;
1013         handle->cur = handle->maps->map;
1014         return 0;
1015 }
1016
1017 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1018                 struct hib_bio_batch *hb)
1019 {
1020         sector_t offset;
1021         int error;
1022         struct swap_map_page_list *tmp;
1023
1024         if (!handle->cur)
1025                 return -EINVAL;
1026         offset = handle->cur->entries[handle->k];
1027         if (!offset)
1028                 return -EFAULT;
1029         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1030         if (error)
1031                 return error;
1032         if (++handle->k >= MAP_PAGE_ENTRIES) {
1033                 handle->k = 0;
1034                 free_page((unsigned long)handle->maps->map);
1035                 tmp = handle->maps;
1036                 handle->maps = handle->maps->next;
1037                 kfree(tmp);
1038                 if (!handle->maps)
1039                         release_swap_reader(handle);
1040                 else
1041                         handle->cur = handle->maps->map;
1042         }
1043         return error;
1044 }
1045
1046 static int swap_reader_finish(struct swap_map_handle *handle)
1047 {
1048         release_swap_reader(handle);
1049
1050         return 0;
1051 }
1052
1053 /**
1054  *      load_image - load the image using the swap map handle
1055  *      @handle and the snapshot handle @snapshot
1056  *      (assume there are @nr_pages pages to load)
1057  */
1058
1059 static int load_image(struct swap_map_handle *handle,
1060                       struct snapshot_handle *snapshot,
1061                       unsigned int nr_to_read)
1062 {
1063         unsigned int m;
1064         int ret = 0;
1065         ktime_t start;
1066         ktime_t stop;
1067         struct hib_bio_batch hb;
1068         int err2;
1069         unsigned nr_pages;
1070
1071         hib_init_batch(&hb);
1072
1073         clean_pages_on_read = true;
1074         pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1075         m = nr_to_read / 10;
1076         if (!m)
1077                 m = 1;
1078         nr_pages = 0;
1079         start = ktime_get();
1080         for ( ; ; ) {
1081                 ret = snapshot_write_next(snapshot);
1082                 if (ret <= 0)
1083                         break;
1084                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1085                 if (ret)
1086                         break;
1087                 if (snapshot->sync_read)
1088                         ret = hib_wait_io(&hb);
1089                 if (ret)
1090                         break;
1091                 if (!(nr_pages % m))
1092                         pr_info("Image loading progress: %3d%%\n",
1093                                 nr_pages / m * 10);
1094                 nr_pages++;
1095         }
1096         err2 = hib_wait_io(&hb);
1097         hib_finish_batch(&hb);
1098         stop = ktime_get();
1099         if (!ret)
1100                 ret = err2;
1101         if (!ret) {
1102                 pr_info("Image loading done\n");
1103                 snapshot_write_finalize(snapshot);
1104                 if (!snapshot_image_loaded(snapshot))
1105                         ret = -ENODATA;
1106         }
1107         swsusp_show_speed(start, stop, nr_to_read, "Read");
1108         return ret;
1109 }
1110
1111 /**
1112  * Structure used for LZO data decompression.
1113  */
1114 struct dec_data {
1115         struct task_struct *thr;                  /* thread */
1116         atomic_t ready;                           /* ready to start flag */
1117         atomic_t stop;                            /* ready to stop flag */
1118         int ret;                                  /* return code */
1119         wait_queue_head_t go;                     /* start decompression */
1120         wait_queue_head_t done;                   /* decompression done */
1121         size_t unc_len;                           /* uncompressed length */
1122         size_t cmp_len;                           /* compressed length */
1123         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1124         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1125 };
1126
1127 /**
1128  * Deompression function that runs in its own thread.
1129  */
1130 static int lzo_decompress_threadfn(void *data)
1131 {
1132         struct dec_data *d = data;
1133
1134         while (1) {
1135                 wait_event(d->go, atomic_read(&d->ready) ||
1136                                   kthread_should_stop());
1137                 if (kthread_should_stop()) {
1138                         d->thr = NULL;
1139                         d->ret = -1;
1140                         atomic_set(&d->stop, 1);
1141                         wake_up(&d->done);
1142                         break;
1143                 }
1144                 atomic_set(&d->ready, 0);
1145
1146                 d->unc_len = LZO_UNC_SIZE;
1147                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1148                                                d->unc, &d->unc_len);
1149                 if (clean_pages_on_decompress)
1150                         flush_icache_range((unsigned long)d->unc,
1151                                            (unsigned long)d->unc + d->unc_len);
1152
1153                 atomic_set(&d->stop, 1);
1154                 wake_up(&d->done);
1155         }
1156         return 0;
1157 }
1158
1159 /**
1160  * load_image_lzo - Load compressed image data and decompress them with LZO.
1161  * @handle: Swap map handle to use for loading data.
1162  * @snapshot: Image to copy uncompressed data into.
1163  * @nr_to_read: Number of pages to load.
1164  */
1165 static int load_image_lzo(struct swap_map_handle *handle,
1166                           struct snapshot_handle *snapshot,
1167                           unsigned int nr_to_read)
1168 {
1169         unsigned int m;
1170         int ret = 0;
1171         int eof = 0;
1172         struct hib_bio_batch hb;
1173         ktime_t start;
1174         ktime_t stop;
1175         unsigned nr_pages;
1176         size_t off;
1177         unsigned i, thr, run_threads, nr_threads;
1178         unsigned ring = 0, pg = 0, ring_size = 0,
1179                  have = 0, want, need, asked = 0;
1180         unsigned long read_pages = 0;
1181         unsigned char **page = NULL;
1182         struct dec_data *data = NULL;
1183         struct crc_data *crc = NULL;
1184
1185         hib_init_batch(&hb);
1186
1187         /*
1188          * We'll limit the number of threads for decompression to limit memory
1189          * footprint.
1190          */
1191         nr_threads = num_online_cpus() - 1;
1192         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1193
1194         page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1195         if (!page) {
1196                 pr_err("Failed to allocate LZO page\n");
1197                 ret = -ENOMEM;
1198                 goto out_clean;
1199         }
1200
1201         data = vmalloc(array_size(nr_threads, sizeof(*data)));
1202         if (!data) {
1203                 pr_err("Failed to allocate LZO data\n");
1204                 ret = -ENOMEM;
1205                 goto out_clean;
1206         }
1207         for (thr = 0; thr < nr_threads; thr++)
1208                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1209
1210         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1211         if (!crc) {
1212                 pr_err("Failed to allocate crc\n");
1213                 ret = -ENOMEM;
1214                 goto out_clean;
1215         }
1216         memset(crc, 0, offsetof(struct crc_data, go));
1217
1218         clean_pages_on_decompress = true;
1219
1220         /*
1221          * Start the decompression threads.
1222          */
1223         for (thr = 0; thr < nr_threads; thr++) {
1224                 init_waitqueue_head(&data[thr].go);
1225                 init_waitqueue_head(&data[thr].done);
1226
1227                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1228                                             &data[thr],
1229                                             "image_decompress/%u", thr);
1230                 if (IS_ERR(data[thr].thr)) {
1231                         data[thr].thr = NULL;
1232                         pr_err("Cannot start decompression threads\n");
1233                         ret = -ENOMEM;
1234                         goto out_clean;
1235                 }
1236         }
1237
1238         /*
1239          * Start the CRC32 thread.
1240          */
1241         init_waitqueue_head(&crc->go);
1242         init_waitqueue_head(&crc->done);
1243
1244         handle->crc32 = 0;
1245         crc->crc32 = &handle->crc32;
1246         for (thr = 0; thr < nr_threads; thr++) {
1247                 crc->unc[thr] = data[thr].unc;
1248                 crc->unc_len[thr] = &data[thr].unc_len;
1249         }
1250
1251         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1252         if (IS_ERR(crc->thr)) {
1253                 crc->thr = NULL;
1254                 pr_err("Cannot start CRC32 thread\n");
1255                 ret = -ENOMEM;
1256                 goto out_clean;
1257         }
1258
1259         /*
1260          * Set the number of pages for read buffering.
1261          * This is complete guesswork, because we'll only know the real
1262          * picture once prepare_image() is called, which is much later on
1263          * during the image load phase. We'll assume the worst case and
1264          * say that none of the image pages are from high memory.
1265          */
1266         if (low_free_pages() > snapshot_get_image_size())
1267                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1268         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1269
1270         for (i = 0; i < read_pages; i++) {
1271                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1272                                                   GFP_NOIO | __GFP_HIGH :
1273                                                   GFP_NOIO | __GFP_NOWARN |
1274                                                   __GFP_NORETRY);
1275
1276                 if (!page[i]) {
1277                         if (i < LZO_CMP_PAGES) {
1278                                 ring_size = i;
1279                                 pr_err("Failed to allocate LZO pages\n");
1280                                 ret = -ENOMEM;
1281                                 goto out_clean;
1282                         } else {
1283                                 break;
1284                         }
1285                 }
1286         }
1287         want = ring_size = i;
1288
1289         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1290         pr_info("Loading and decompressing image data (%u pages)...\n",
1291                 nr_to_read);
1292         m = nr_to_read / 10;
1293         if (!m)
1294                 m = 1;
1295         nr_pages = 0;
1296         start = ktime_get();
1297
1298         ret = snapshot_write_next(snapshot);
1299         if (ret <= 0)
1300                 goto out_finish;
1301
1302         for(;;) {
1303                 for (i = 0; !eof && i < want; i++) {
1304                         ret = swap_read_page(handle, page[ring], &hb);
1305                         if (ret) {
1306                                 /*
1307                                  * On real read error, finish. On end of data,
1308                                  * set EOF flag and just exit the read loop.
1309                                  */
1310                                 if (handle->cur &&
1311                                     handle->cur->entries[handle->k]) {
1312                                         goto out_finish;
1313                                 } else {
1314                                         eof = 1;
1315                                         break;
1316                                 }
1317                         }
1318                         if (++ring >= ring_size)
1319                                 ring = 0;
1320                 }
1321                 asked += i;
1322                 want -= i;
1323
1324                 /*
1325                  * We are out of data, wait for some more.
1326                  */
1327                 if (!have) {
1328                         if (!asked)
1329                                 break;
1330
1331                         ret = hib_wait_io(&hb);
1332                         if (ret)
1333                                 goto out_finish;
1334                         have += asked;
1335                         asked = 0;
1336                         if (eof)
1337                                 eof = 2;
1338                 }
1339
1340                 if (crc->run_threads) {
1341                         wait_event(crc->done, atomic_read(&crc->stop));
1342                         atomic_set(&crc->stop, 0);
1343                         crc->run_threads = 0;
1344                 }
1345
1346                 for (thr = 0; have && thr < nr_threads; thr++) {
1347                         data[thr].cmp_len = *(size_t *)page[pg];
1348                         if (unlikely(!data[thr].cmp_len ||
1349                                      data[thr].cmp_len >
1350                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1351                                 pr_err("Invalid LZO compressed length\n");
1352                                 ret = -1;
1353                                 goto out_finish;
1354                         }
1355
1356                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1357                                             PAGE_SIZE);
1358                         if (need > have) {
1359                                 if (eof > 1) {
1360                                         ret = -1;
1361                                         goto out_finish;
1362                                 }
1363                                 break;
1364                         }
1365
1366                         for (off = 0;
1367                              off < LZO_HEADER + data[thr].cmp_len;
1368                              off += PAGE_SIZE) {
1369                                 memcpy(data[thr].cmp + off,
1370                                        page[pg], PAGE_SIZE);
1371                                 have--;
1372                                 want++;
1373                                 if (++pg >= ring_size)
1374                                         pg = 0;
1375                         }
1376
1377                         atomic_set(&data[thr].ready, 1);
1378                         wake_up(&data[thr].go);
1379                 }
1380
1381                 /*
1382                  * Wait for more data while we are decompressing.
1383                  */
1384                 if (have < LZO_CMP_PAGES && asked) {
1385                         ret = hib_wait_io(&hb);
1386                         if (ret)
1387                                 goto out_finish;
1388                         have += asked;
1389                         asked = 0;
1390                         if (eof)
1391                                 eof = 2;
1392                 }
1393
1394                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1395                         wait_event(data[thr].done,
1396                                    atomic_read(&data[thr].stop));
1397                         atomic_set(&data[thr].stop, 0);
1398
1399                         ret = data[thr].ret;
1400
1401                         if (ret < 0) {
1402                                 pr_err("LZO decompression failed\n");
1403                                 goto out_finish;
1404                         }
1405
1406                         if (unlikely(!data[thr].unc_len ||
1407                                      data[thr].unc_len > LZO_UNC_SIZE ||
1408                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1409                                 pr_err("Invalid LZO uncompressed length\n");
1410                                 ret = -1;
1411                                 goto out_finish;
1412                         }
1413
1414                         for (off = 0;
1415                              off < data[thr].unc_len; off += PAGE_SIZE) {
1416                                 memcpy(data_of(*snapshot),
1417                                        data[thr].unc + off, PAGE_SIZE);
1418
1419                                 if (!(nr_pages % m))
1420                                         pr_info("Image loading progress: %3d%%\n",
1421                                                 nr_pages / m * 10);
1422                                 nr_pages++;
1423
1424                                 ret = snapshot_write_next(snapshot);
1425                                 if (ret <= 0) {
1426                                         crc->run_threads = thr + 1;
1427                                         atomic_set(&crc->ready, 1);
1428                                         wake_up(&crc->go);
1429                                         goto out_finish;
1430                                 }
1431                         }
1432                 }
1433
1434                 crc->run_threads = thr;
1435                 atomic_set(&crc->ready, 1);
1436                 wake_up(&crc->go);
1437         }
1438
1439 out_finish:
1440         if (crc->run_threads) {
1441                 wait_event(crc->done, atomic_read(&crc->stop));
1442                 atomic_set(&crc->stop, 0);
1443         }
1444         stop = ktime_get();
1445         if (!ret) {
1446                 pr_info("Image loading done\n");
1447                 snapshot_write_finalize(snapshot);
1448                 if (!snapshot_image_loaded(snapshot))
1449                         ret = -ENODATA;
1450                 if (!ret) {
1451                         if (swsusp_header->flags & SF_CRC32_MODE) {
1452                                 if(handle->crc32 != swsusp_header->crc32) {
1453                                         pr_err("Invalid image CRC32!\n");
1454                                         ret = -ENODATA;
1455                                 }
1456                         }
1457                 }
1458         }
1459         swsusp_show_speed(start, stop, nr_to_read, "Read");
1460 out_clean:
1461         hib_finish_batch(&hb);
1462         for (i = 0; i < ring_size; i++)
1463                 free_page((unsigned long)page[i]);
1464         if (crc) {
1465                 if (crc->thr)
1466                         kthread_stop(crc->thr);
1467                 kfree(crc);
1468         }
1469         if (data) {
1470                 for (thr = 0; thr < nr_threads; thr++)
1471                         if (data[thr].thr)
1472                                 kthread_stop(data[thr].thr);
1473                 vfree(data);
1474         }
1475         vfree(page);
1476
1477         return ret;
1478 }
1479
1480 /**
1481  *      swsusp_read - read the hibernation image.
1482  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1483  *                be written into this memory location
1484  */
1485
1486 int swsusp_read(unsigned int *flags_p)
1487 {
1488         int error;
1489         struct swap_map_handle handle;
1490         struct snapshot_handle snapshot;
1491         struct swsusp_info *header;
1492
1493         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1494         error = snapshot_write_next(&snapshot);
1495         if (error < (int)PAGE_SIZE)
1496                 return error < 0 ? error : -EFAULT;
1497         header = (struct swsusp_info *)data_of(snapshot);
1498         error = get_swap_reader(&handle, flags_p);
1499         if (error)
1500                 goto end;
1501         if (!error)
1502                 error = swap_read_page(&handle, header, NULL);
1503         if (!error) {
1504                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1505                         load_image(&handle, &snapshot, header->pages - 1) :
1506                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1507         }
1508         swap_reader_finish(&handle);
1509 end:
1510         if (!error)
1511                 pr_debug("Image successfully loaded\n");
1512         else
1513                 pr_debug("Error %d resuming\n", error);
1514         return error;
1515 }
1516
1517 /**
1518  *      swsusp_check - Check for swsusp signature in the resume device
1519  */
1520
1521 int swsusp_check(void)
1522 {
1523         int error;
1524
1525         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1526                                             FMODE_READ, NULL);
1527         if (!IS_ERR(hib_resume_bdev)) {
1528                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1529                 clear_page(swsusp_header);
1530                 error = hib_submit_io(REQ_OP_READ, 0,
1531                                         swsusp_resume_block,
1532                                         swsusp_header, NULL);
1533                 if (error)
1534                         goto put;
1535
1536                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1537                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1538                         /* Reset swap signature now */
1539                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1540                                                 swsusp_resume_block,
1541                                                 swsusp_header, NULL);
1542                 } else {
1543                         error = -EINVAL;
1544                 }
1545
1546 put:
1547                 if (error)
1548                         blkdev_put(hib_resume_bdev, FMODE_READ);
1549                 else
1550                         pr_debug("Image signature found, resuming\n");
1551         } else {
1552                 error = PTR_ERR(hib_resume_bdev);
1553         }
1554
1555         if (error)
1556                 pr_debug("Image not found (code %d)\n", error);
1557
1558         return error;
1559 }
1560
1561 /**
1562  *      swsusp_close - close swap device.
1563  */
1564
1565 void swsusp_close(fmode_t mode)
1566 {
1567         if (IS_ERR(hib_resume_bdev)) {
1568                 pr_debug("Image device not initialised\n");
1569                 return;
1570         }
1571
1572         blkdev_put(hib_resume_bdev, mode);
1573 }
1574
1575 /**
1576  *      swsusp_unmark - Unmark swsusp signature in the resume device
1577  */
1578
1579 #ifdef CONFIG_SUSPEND
1580 int swsusp_unmark(void)
1581 {
1582         int error;
1583
1584         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1585                       swsusp_header, NULL);
1586         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1587                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1588                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1589                                         swsusp_resume_block,
1590                                         swsusp_header, NULL);
1591         } else {
1592                 pr_err("Cannot find swsusp signature!\n");
1593                 error = -ENODEV;
1594         }
1595
1596         /*
1597          * We just returned from suspend, we don't need the image any more.
1598          */
1599         free_all_swap_pages(root_swap);
1600
1601         return error;
1602 }
1603 #endif
1604
1605 static int __init swsusp_header_init(void)
1606 {
1607         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1608         if (!swsusp_header)
1609                 panic("Could not allocate memory for swsusp_header\n");
1610         return 0;
1611 }
1612
1613 core_initcall(swsusp_header_init);