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 <pavel@ucw.cz>
   9  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
  10  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
  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 int 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                 pr_info("S");
 501                 error = mark_swapfiles(handle, flags);
 502                 pr_cont("|\n");
 503                 flush_swap_writer(handle);
 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 = vzalloc(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
 715         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
 716         if (!crc) {
 717                 pr_err("Failed to allocate crc\n");
 718                 ret = -ENOMEM;
 719                 goto out_clean;
 720         }
 721
 722         /*
 723          * Start the compression threads.
 724          */
 725         for (thr = 0; thr < nr_threads; thr++) {
 726                 init_waitqueue_head(&data[thr].go);
 727                 init_waitqueue_head(&data[thr].done);
 728
 729                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 730                                             &data[thr],
 731                                             "image_compress/%u", thr);
 732                 if (IS_ERR(data[thr].thr)) {
 733                         data[thr].thr = NULL;
 734                         pr_err("Cannot start compression threads\n");
 735                         ret = -ENOMEM;
 736                         goto out_clean;
 737                 }
 738         }
 739
 740         /*
 741          * Start the CRC32 thread.
 742          */
 743         init_waitqueue_head(&crc->go);
 744         init_waitqueue_head(&crc->done);
 745
 746         handle->crc32 = 0;
 747         crc->crc32 = &handle->crc32;
 748         for (thr = 0; thr < nr_threads; thr++) {
 749                 crc->unc[thr] = data[thr].unc;
 750                 crc->unc_len[thr] = &data[thr].unc_len;
 751         }
 752
 753         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 754         if (IS_ERR(crc->thr)) {
 755                 crc->thr = NULL;
 756                 pr_err("Cannot start CRC32 thread\n");
 757                 ret = -ENOMEM;
 758                 goto out_clean;
 759         }
 760
 761         /*
 762          * Adjust the number of required free pages after all allocations have
 763          * been done. We don't want to run out of pages when writing.
 764          */
 765         handle->reqd_free_pages = reqd_free_pages();
 766
 767         pr_info("Using %u thread(s) for compression\n", nr_threads);
 768         pr_info("Compressing and saving image data (%u pages)...\n",
 769                 nr_to_write);
 770         m = nr_to_write / 10;
 771         if (!m)
 772                 m = 1;
 773         nr_pages = 0;
 774         start = ktime_get();
 775         for (;;) {
 776                 for (thr = 0; thr < nr_threads; thr++) {
 777                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 778                                 ret = snapshot_read_next(snapshot);
 779                                 if (ret < 0)
 780                                         goto out_finish;
 781
 782                                 if (!ret)
 783                                         break;
 784
 785                                 memcpy(data[thr].unc + off,
 786                                        data_of(*snapshot), PAGE_SIZE);
 787
 788                                 if (!(nr_pages % m))
 789                                         pr_info("Image saving progress: %3d%%\n",
 790                                                 nr_pages / m * 10);
 791                                 nr_pages++;
 792                         }
 793                         if (!off)
 794                                 break;
 795
 796                         data[thr].unc_len = off;
 797
 798                         atomic_set(&data[thr].ready, 1);
 799                         wake_up(&data[thr].go);
 800                 }
 801
 802                 if (!thr)
 803                         break;
 804
 805                 crc->run_threads = thr;
 806                 atomic_set(&crc->ready, 1);
 807                 wake_up(&crc->go);
 808
 809                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 810                         wait_event(data[thr].done,
 811                                    atomic_read(&data[thr].stop));
 812                         atomic_set(&data[thr].stop, 0);
 813
 814                         ret = data[thr].ret;
 815
 816                         if (ret < 0) {
 817                                 pr_err("LZO compression failed\n");
 818                                 goto out_finish;
 819                         }
 820
 821                         if (unlikely(!data[thr].cmp_len ||
 822                                      data[thr].cmp_len >
 823                                      lzo1x_worst_compress(data[thr].unc_len))) {
 824                                 pr_err("Invalid LZO compressed length\n");
 825                                 ret = -1;
 826                                 goto out_finish;
 827                         }
 828
 829                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 830
 831                         /*
 832                          * Given we are writing one page at a time to disk, we
 833                          * copy that much from the buffer, although the last
 834                          * bit will likely be smaller than full page. This is
 835                          * OK - we saved the length of the compressed data, so
 836                          * any garbage at the end will be discarded when we
 837                          * read it.
 838                          */
 839                         for (off = 0;
 840                              off < LZO_HEADER + data[thr].cmp_len;
 841                              off += PAGE_SIZE) {
 842                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 843
 844                                 ret = swap_write_page(handle, page, &hb);
 845                                 if (ret)
 846                                         goto out_finish;
 847                         }
 848                 }
 849
 850                 wait_event(crc->done, atomic_read(&crc->stop));
 851                 atomic_set(&crc->stop, 0);
 852         }
 853
 854 out_finish:
 855         err2 = hib_wait_io(&hb);
 856         stop = ktime_get();
 857         if (!ret)
 858                 ret = err2;
 859         if (!ret)
 860                 pr_info("Image saving done\n");
 861         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 862 out_clean:
 863         hib_finish_batch(&hb);
 864         if (crc) {
 865                 if (crc->thr)
 866                         kthread_stop(crc->thr);
 867                 kfree(crc);
 868         }
 869         if (data) {
 870                 for (thr = 0; thr < nr_threads; thr++)
 871                         if (data[thr].thr)
 872                                 kthread_stop(data[thr].thr);
 873                 vfree(data);
 874         }
 875         if (page) free_page((unsigned long)page);
 876
 877         return ret;
 878 }
 879
 880 /**
 881  *      enough_swap - Make sure we have enough swap to save the image.
 882  *
 883  *      Returns TRUE or FALSE after checking the total amount of swap
 884  *      space available from the resume partition.
 885  */
 886
 887 static int enough_swap(unsigned int nr_pages)
 888 {
 889         unsigned int free_swap = count_swap_pages(root_swap, 1);
 890         unsigned int required;
 891
 892         pr_debug("Free swap pages: %u\n", free_swap);
 893
 894         required = PAGES_FOR_IO + nr_pages;
 895         return free_swap > required;
 896 }
 897
 898 /**
 899  *      swsusp_write - Write entire image and metadata.
 900  *      @flags: flags to pass to the "boot" kernel in the image header
 901  *
 902  *      It is important _NOT_ to umount filesystems at this point. We want
 903  *      them synced (in case something goes wrong) but we DO not want to mark
 904  *      filesystem clean: it is not. (And it does not matter, if we resume
 905  *      correctly, we'll mark system clean, anyway.)
 906  */
 907
 908 int swsusp_write(unsigned int flags)
 909 {
 910         struct swap_map_handle handle;
 911         struct snapshot_handle snapshot;
 912         struct swsusp_info *header;
 913         unsigned long pages;
 914         int error;
 915
 916         pages = snapshot_get_image_size();
 917         error = get_swap_writer(&handle);
 918         if (error) {
 919                 pr_err("Cannot get swap writer\n");
 920                 return error;
 921         }
 922         if (flags & SF_NOCOMPRESS_MODE) {
 923                 if (!enough_swap(pages)) {
 924                         pr_err("Not enough free swap\n");
 925                         error = -ENOSPC;
 926                         goto out_finish;
 927                 }
 928         }
 929         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 930         error = snapshot_read_next(&snapshot);
 931         if (error < (int)PAGE_SIZE) {
 932                 if (error >= 0)
 933                         error = -EFAULT;
 934
 935                 goto out_finish;
 936         }
 937         header = (struct swsusp_info *)data_of(snapshot);
 938         error = swap_write_page(&handle, header, NULL);
 939         if (!error) {
 940                 error = (flags & SF_NOCOMPRESS_MODE) ?
 941                         save_image(&handle, &snapshot, pages - 1) :
 942                         save_image_lzo(&handle, &snapshot, pages - 1);
 943         }
 944 out_finish:
 945         error = swap_writer_finish(&handle, flags, error);
 946         return error;
 947 }
 948
 949 /**
 950  *      The following functions allow us to read data using a swap map
 951  *      in a file-alike way
 952  */
 953
 954 static void release_swap_reader(struct swap_map_handle *handle)
 955 {
 956         struct swap_map_page_list *tmp;
 957
 958         while (handle->maps) {
 959                 if (handle->maps->map)
 960                         free_page((unsigned long)handle->maps->map);
 961                 tmp = handle->maps;
 962                 handle->maps = handle->maps->next;
 963                 kfree(tmp);
 964         }
 965         handle->cur = NULL;
 966 }
 967
 968 static int get_swap_reader(struct swap_map_handle *handle,
 969                 unsigned int *flags_p)
 970 {
 971         int error;
 972         struct swap_map_page_list *tmp, *last;
 973         sector_t offset;
 974
 975         *flags_p = swsusp_header->flags;
 976
 977         if (!swsusp_header->image) /* how can this happen? */
 978                 return -EINVAL;
 979
 980         handle->cur = NULL;
 981         last = handle->maps = NULL;
 982         offset = swsusp_header->image;
 983         while (offset) {
 984                 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
 985                 if (!tmp) {
 986                         release_swap_reader(handle);
 987                         return -ENOMEM;
 988                 }
 989                 if (!handle->maps)
 990                         handle->maps = tmp;
 991                 if (last)
 992                         last->next = tmp;
 993                 last = tmp;
 994
 995                 tmp->map = (struct swap_map_page *)
 996                            __get_free_page(GFP_NOIO | __GFP_HIGH);
 997                 if (!tmp->map) {
 998                         release_swap_reader(handle);
 999                         return -ENOMEM;
1000                 }
1001
1002                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1003                 if (error) {
1004                         release_swap_reader(handle);
1005                         return error;
1006                 }
1007                 offset = tmp->map->next_swap;
1008         }
1009         handle->k = 0;
1010         handle->cur = handle->maps->map;
1011         return 0;
1012 }
1013
1014 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1015                 struct hib_bio_batch *hb)
1016 {
1017         sector_t offset;
1018         int error;
1019         struct swap_map_page_list *tmp;
1020
1021         if (!handle->cur)
1022                 return -EINVAL;
1023         offset = handle->cur->entries[handle->k];
1024         if (!offset)
1025                 return -EFAULT;
1026         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1027         if (error)
1028                 return error;
1029         if (++handle->k >= MAP_PAGE_ENTRIES) {
1030                 handle->k = 0;
1031                 free_page((unsigned long)handle->maps->map);
1032                 tmp = handle->maps;
1033                 handle->maps = handle->maps->next;
1034                 kfree(tmp);
1035                 if (!handle->maps)
1036                         release_swap_reader(handle);
1037                 else
1038                         handle->cur = handle->maps->map;
1039         }
1040         return error;
1041 }
1042
1043 static int swap_reader_finish(struct swap_map_handle *handle)
1044 {
1045         release_swap_reader(handle);
1046
1047         return 0;
1048 }
1049
1050 /**
1051  *      load_image - load the image using the swap map handle
1052  *      @handle and the snapshot handle @snapshot
1053  *      (assume there are @nr_pages pages to load)
1054  */
1055
1056 static int load_image(struct swap_map_handle *handle,
1057                       struct snapshot_handle *snapshot,
1058                       unsigned int nr_to_read)
1059 {
1060         unsigned int m;
1061         int ret = 0;
1062         ktime_t start;
1063         ktime_t stop;
1064         struct hib_bio_batch hb;
1065         int err2;
1066         unsigned nr_pages;
1067
1068         hib_init_batch(&hb);
1069
1070         clean_pages_on_read = true;
1071         pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1072         m = nr_to_read / 10;
1073         if (!m)
1074                 m = 1;
1075         nr_pages = 0;
1076         start = ktime_get();
1077         for ( ; ; ) {
1078                 ret = snapshot_write_next(snapshot);
1079                 if (ret <= 0)
1080                         break;
1081                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1082                 if (ret)
1083                         break;
1084                 if (snapshot->sync_read)
1085                         ret = hib_wait_io(&hb);
1086                 if (ret)
1087                         break;
1088                 if (!(nr_pages % m))
1089                         pr_info("Image loading progress: %3d%%\n",
1090                                 nr_pages / m * 10);
1091                 nr_pages++;
1092         }
1093         err2 = hib_wait_io(&hb);
1094         hib_finish_batch(&hb);
1095         stop = ktime_get();
1096         if (!ret)
1097                 ret = err2;
1098         if (!ret) {
1099                 pr_info("Image loading done\n");
1100                 snapshot_write_finalize(snapshot);
1101                 if (!snapshot_image_loaded(snapshot))
1102                         ret = -ENODATA;
1103         }
1104         swsusp_show_speed(start, stop, nr_to_read, "Read");
1105         return ret;
1106 }
1107
1108 /**
1109  * Structure used for LZO data decompression.
1110  */
1111 struct dec_data {
1112         struct task_struct *thr;                  /* thread */
1113         atomic_t ready;                           /* ready to start flag */
1114         atomic_t stop;                            /* ready to stop flag */
1115         int ret;                                  /* return code */
1116         wait_queue_head_t go;                     /* start decompression */
1117         wait_queue_head_t done;                   /* decompression done */
1118         size_t unc_len;                           /* uncompressed length */
1119         size_t cmp_len;                           /* compressed length */
1120         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1121         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1122 };
1123
1124 /**
1125  * Decompression function that runs in its own thread.
1126  */
1127 static int lzo_decompress_threadfn(void *data)
1128 {
1129         struct dec_data *d = data;
1130
1131         while (1) {
1132                 wait_event(d->go, atomic_read(&d->ready) ||
1133                                   kthread_should_stop());
1134                 if (kthread_should_stop()) {
1135                         d->thr = NULL;
1136                         d->ret = -1;
1137                         atomic_set(&d->stop, 1);
1138                         wake_up(&d->done);
1139                         break;
1140                 }
1141                 atomic_set(&d->ready, 0);
1142
1143                 d->unc_len = LZO_UNC_SIZE;
1144                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1145                                                d->unc, &d->unc_len);
1146                 if (clean_pages_on_decompress)
1147                         flush_icache_range((unsigned long)d->unc,
1148                                            (unsigned long)d->unc + d->unc_len);
1149
1150                 atomic_set(&d->stop, 1);
1151                 wake_up(&d->done);
1152         }
1153         return 0;
1154 }
1155
1156 /**
1157  * load_image_lzo - Load compressed image data and decompress them with LZO.
1158  * @handle: Swap map handle to use for loading data.
1159  * @snapshot: Image to copy uncompressed data into.
1160  * @nr_to_read: Number of pages to load.
1161  */
1162 static int load_image_lzo(struct swap_map_handle *handle,
1163                           struct snapshot_handle *snapshot,
1164                           unsigned int nr_to_read)
1165 {
1166         unsigned int m;
1167         int ret = 0;
1168         int eof = 0;
1169         struct hib_bio_batch hb;
1170         ktime_t start;
1171         ktime_t stop;
1172         unsigned nr_pages;
1173         size_t off;
1174         unsigned i, thr, run_threads, nr_threads;
1175         unsigned ring = 0, pg = 0, ring_size = 0,
1176                  have = 0, want, need, asked = 0;
1177         unsigned long read_pages = 0;
1178         unsigned char **page = NULL;
1179         struct dec_data *data = NULL;
1180         struct crc_data *crc = NULL;
1181
1182         hib_init_batch(&hb);
1183
1184         /*
1185          * We'll limit the number of threads for decompression to limit memory
1186          * footprint.
1187          */
1188         nr_threads = num_online_cpus() - 1;
1189         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1190
1191         page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1192         if (!page) {
1193                 pr_err("Failed to allocate LZO page\n");
1194                 ret = -ENOMEM;
1195                 goto out_clean;
1196         }
1197
1198         data = vzalloc(array_size(nr_threads, sizeof(*data)));
1199         if (!data) {
1200                 pr_err("Failed to allocate LZO data\n");
1201                 ret = -ENOMEM;
1202                 goto out_clean;
1203         }
1204
1205         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1206         if (!crc) {
1207                 pr_err("Failed to allocate crc\n");
1208                 ret = -ENOMEM;
1209                 goto out_clean;
1210         }
1211
1212         clean_pages_on_decompress = true;
1213
1214         /*
1215          * Start the decompression threads.
1216          */
1217         for (thr = 0; thr < nr_threads; thr++) {
1218                 init_waitqueue_head(&data[thr].go);
1219                 init_waitqueue_head(&data[thr].done);
1220
1221                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1222                                             &data[thr],
1223                                             "image_decompress/%u", thr);
1224                 if (IS_ERR(data[thr].thr)) {
1225                         data[thr].thr = NULL;
1226                         pr_err("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                 pr_err("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_NOIO | __GFP_HIGH :
1267                                                   GFP_NOIO | __GFP_NOWARN |
1268                                                   __GFP_NORETRY);
1269
1270                 if (!page[i]) {
1271                         if (i < LZO_CMP_PAGES) {
1272                                 ring_size = i;
1273                                 pr_err("Failed to allocate LZO pages\n");
1274                                 ret = -ENOMEM;
1275                                 goto out_clean;
1276                         } else {
1277                                 break;
1278                         }
1279                 }
1280         }
1281         want = ring_size = i;
1282
1283         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1284         pr_info("Loading and decompressing image data (%u pages)...\n",
1285                 nr_to_read);
1286         m = nr_to_read / 10;
1287         if (!m)
1288                 m = 1;
1289         nr_pages = 0;
1290         start = ktime_get();
1291
1292         ret = snapshot_write_next(snapshot);
1293         if (ret <= 0)
1294                 goto out_finish;
1295
1296         for(;;) {
1297                 for (i = 0; !eof && i < want; i++) {
1298                         ret = swap_read_page(handle, page[ring], &hb);
1299                         if (ret) {
1300                                 /*
1301                                  * On real read error, finish. On end of data,
1302                                  * set EOF flag and just exit the read loop.
1303                                  */
1304                                 if (handle->cur &&
1305                                     handle->cur->entries[handle->k]) {
1306                                         goto out_finish;
1307                                 } else {
1308                                         eof = 1;
1309                                         break;
1310                                 }
1311                         }
1312                         if (++ring >= ring_size)
1313                                 ring = 0;
1314                 }
1315                 asked += i;
1316                 want -= i;
1317
1318                 /*
1319                  * We are out of data, wait for some more.
1320                  */
1321                 if (!have) {
1322                         if (!asked)
1323                                 break;
1324
1325                         ret = hib_wait_io(&hb);
1326                         if (ret)
1327                                 goto out_finish;
1328                         have += asked;
1329                         asked = 0;
1330                         if (eof)
1331                                 eof = 2;
1332                 }
1333
1334                 if (crc->run_threads) {
1335                         wait_event(crc->done, atomic_read(&crc->stop));
1336                         atomic_set(&crc->stop, 0);
1337                         crc->run_threads = 0;
1338                 }
1339
1340                 for (thr = 0; have && thr < nr_threads; thr++) {
1341                         data[thr].cmp_len = *(size_t *)page[pg];
1342                         if (unlikely(!data[thr].cmp_len ||
1343                                      data[thr].cmp_len >
1344                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1345                                 pr_err("Invalid LZO compressed length\n");
1346                                 ret = -1;
1347                                 goto out_finish;
1348                         }
1349
1350                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1351                                             PAGE_SIZE);
1352                         if (need > have) {
1353                                 if (eof > 1) {
1354                                         ret = -1;
1355                                         goto out_finish;
1356                                 }
1357                                 break;
1358                         }
1359
1360                         for (off = 0;
1361                              off < LZO_HEADER + data[thr].cmp_len;
1362                              off += PAGE_SIZE) {
1363                                 memcpy(data[thr].cmp + off,
1364                                        page[pg], PAGE_SIZE);
1365                                 have--;
1366                                 want++;
1367                                 if (++pg >= ring_size)
1368                                         pg = 0;
1369                         }
1370
1371                         atomic_set(&data[thr].ready, 1);
1372                         wake_up(&data[thr].go);
1373                 }
1374
1375                 /*
1376                  * Wait for more data while we are decompressing.
1377                  */
1378                 if (have < LZO_CMP_PAGES && asked) {
1379                         ret = hib_wait_io(&hb);
1380                         if (ret)
1381                                 goto out_finish;
1382                         have += asked;
1383                         asked = 0;
1384                         if (eof)
1385                                 eof = 2;
1386                 }
1387
1388                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1389                         wait_event(data[thr].done,
1390                                    atomic_read(&data[thr].stop));
1391                         atomic_set(&data[thr].stop, 0);
1392
1393                         ret = data[thr].ret;
1394
1395                         if (ret < 0) {
1396                                 pr_err("LZO decompression failed\n");
1397                                 goto out_finish;
1398                         }
1399
1400                         if (unlikely(!data[thr].unc_len ||
1401                                      data[thr].unc_len > LZO_UNC_SIZE ||
1402                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1403                                 pr_err("Invalid LZO uncompressed length\n");
1404                                 ret = -1;
1405                                 goto out_finish;
1406                         }
1407
1408                         for (off = 0;
1409                              off < data[thr].unc_len; off += PAGE_SIZE) {
1410                                 memcpy(data_of(*snapshot),
1411                                        data[thr].unc + off, PAGE_SIZE);
1412
1413                                 if (!(nr_pages % m))
1414                                         pr_info("Image loading progress: %3d%%\n",
1415                                                 nr_pages / m * 10);
1416                                 nr_pages++;
1417
1418                                 ret = snapshot_write_next(snapshot);
1419                                 if (ret <= 0) {
1420                                         crc->run_threads = thr + 1;
1421                                         atomic_set(&crc->ready, 1);
1422                                         wake_up(&crc->go);
1423                                         goto out_finish;
1424                                 }
1425                         }
1426                 }
1427
1428                 crc->run_threads = thr;
1429                 atomic_set(&crc->ready, 1);
1430                 wake_up(&crc->go);
1431         }
1432
1433 out_finish:
1434         if (crc->run_threads) {
1435                 wait_event(crc->done, atomic_read(&crc->stop));
1436                 atomic_set(&crc->stop, 0);
1437         }
1438         stop = ktime_get();
1439         if (!ret) {
1440                 pr_info("Image loading done\n");
1441                 snapshot_write_finalize(snapshot);
1442                 if (!snapshot_image_loaded(snapshot))
1443                         ret = -ENODATA;
1444                 if (!ret) {
1445                         if (swsusp_header->flags & SF_CRC32_MODE) {
1446                                 if(handle->crc32 != swsusp_header->crc32) {
1447                                         pr_err("Invalid image CRC32!\n");
1448                                         ret = -ENODATA;
1449                                 }
1450                         }
1451                 }
1452         }
1453         swsusp_show_speed(start, stop, nr_to_read, "Read");
1454 out_clean:
1455         hib_finish_batch(&hb);
1456         for (i = 0; i < ring_size; i++)
1457                 free_page((unsigned long)page[i]);
1458         if (crc) {
1459                 if (crc->thr)
1460                         kthread_stop(crc->thr);
1461                 kfree(crc);
1462         }
1463         if (data) {
1464                 for (thr = 0; thr < nr_threads; thr++)
1465                         if (data[thr].thr)
1466                                 kthread_stop(data[thr].thr);
1467                 vfree(data);
1468         }
1469         vfree(page);
1470
1471         return ret;
1472 }
1473
1474 /**
1475  *      swsusp_read - read the hibernation image.
1476  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1477  *                be written into this memory location
1478  */
1479
1480 int swsusp_read(unsigned int *flags_p)
1481 {
1482         int error;
1483         struct swap_map_handle handle;
1484         struct snapshot_handle snapshot;
1485         struct swsusp_info *header;
1486
1487         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1488         error = snapshot_write_next(&snapshot);
1489         if (error < (int)PAGE_SIZE)
1490                 return error < 0 ? error : -EFAULT;
1491         header = (struct swsusp_info *)data_of(snapshot);
1492         error = get_swap_reader(&handle, flags_p);
1493         if (error)
1494                 goto end;
1495         if (!error)
1496                 error = swap_read_page(&handle, header, NULL);
1497         if (!error) {
1498                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1499                         load_image(&handle, &snapshot, header->pages - 1) :
1500                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1501         }
1502         swap_reader_finish(&handle);
1503 end:
1504         if (!error)
1505                 pr_debug("Image successfully loaded\n");
1506         else
1507                 pr_debug("Error %d resuming\n", error);
1508         return error;
1509 }
1510
1511 /**
1512  *      swsusp_check - Check for swsusp signature in the resume device
1513  */
1514
1515 int swsusp_check(void)
1516 {
1517         int error;
1518         void *holder;
1519
1520         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1521                                             FMODE_READ | FMODE_EXCL, &holder);
1522         if (!IS_ERR(hib_resume_bdev)) {
1523                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1524                 clear_page(swsusp_header);
1525                 error = hib_submit_io(REQ_OP_READ, 0,
1526                                         swsusp_resume_block,
1527                                         swsusp_header, NULL);
1528                 if (error)
1529                         goto put;
1530
1531                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1532                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1533                         /* Reset swap signature now */
1534                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1535                                                 swsusp_resume_block,
1536                                                 swsusp_header, NULL);
1537                 } else {
1538                         error = -EINVAL;
1539                 }
1540
1541 put:
1542                 if (error)
1543                         blkdev_put(hib_resume_bdev, FMODE_READ | FMODE_EXCL);
1544                 else
1545                         pr_debug("Image signature found, resuming\n");
1546         } else {
1547                 error = PTR_ERR(hib_resume_bdev);
1548         }
1549
1550         if (error)
1551                 pr_debug("Image not found (code %d)\n", error);
1552
1553         return error;
1554 }
1555
1556 /**
1557  *      swsusp_close - close swap device.
1558  */
1559
1560 void swsusp_close(fmode_t mode)
1561 {
1562         if (IS_ERR(hib_resume_bdev)) {
1563                 pr_debug("Image device not initialised\n");
1564                 return;
1565         }
1566
1567         blkdev_put(hib_resume_bdev, mode);
1568 }
1569
1570 /**
1571  *      swsusp_unmark - Unmark swsusp signature in the resume device
1572  */
1573
1574 #ifdef CONFIG_SUSPEND
1575 int swsusp_unmark(void)
1576 {
1577         int error;
1578
1579         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1580                       swsusp_header, NULL);
1581         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1582                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1583                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1584                                         swsusp_resume_block,
1585                                         swsusp_header, NULL);
1586         } else {
1587                 pr_err("Cannot find swsusp signature!\n");
1588                 error = -ENODEV;
1589         }
1590
1591         /*
1592          * We just returned from suspend, we don't need the image any more.
1593          */
1594         free_all_swap_pages(root_swap);
1595
1596         return error;
1597 }
1598 #endif
1599
1600 static int __init swsusp_header_init(void)
1601 {
1602         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1603         if (!swsusp_header)
1604                 panic("Could not allocate memory for swsusp_header\n");
1605         return 0;
1606 }
1607
1608 core_initcall(swsusp_header_init);