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/device.h>
  20 #include <linux/bio.h>
  21 #include <linux/blkdev.h>
  22 #include <linux/swap.h>
  23 #include <linux/swapops.h>
  24 #include <linux/pm.h>
  25 #include <linux/slab.h>
  26 #include <linux/lzo.h>
  27 #include <linux/vmalloc.h>
  28 #include <linux/cpumask.h>
  29 #include <linux/atomic.h>
  30 #include <linux/kthread.h>
  31 #include <linux/crc32.h>
  32 #include <linux/ktime.h>
  33
  34 #include "power.h"
  35
  36 #define HIBERNATE_SIG   "S1SUSPEND"
  37
  38 u32 swsusp_hardware_signature;
  39
  40 /*
  41  * When reading an {un,}compressed image, we may restore pages in place,
  42  * in which case some architectures need these pages cleaning before they
  43  * can be executed. We don't know which pages these may be, so clean the lot.
  44  */
  45 static bool clean_pages_on_read;
  46 static bool clean_pages_on_decompress;
  47
  48 /*
  49  *      The swap map is a data structure used for keeping track of each page
  50  *      written to a swap partition.  It consists of many swap_map_page
  51  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  52  *      These structures are stored on the swap and linked together with the
  53  *      help of the .next_swap member.
  54  *
  55  *      The swap map is created during suspend.  The swap map pages are
  56  *      allocated and populated one at a time, so we only need one memory
  57  *      page to set up the entire structure.
  58  *
  59  *      During resume we pick up all swap_map_page structures into a list.
  60  */
  61
  62 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  63
  64 /*
  65  * Number of free pages that are not high.
  66  */
  67 static inline unsigned long low_free_pages(void)
  68 {
  69         return nr_free_pages() - nr_free_highpages();
  70 }
  71
  72 /*
  73  * Number of pages required to be kept free while writing the image. Always
  74  * half of all available low pages before the writing starts.
  75  */
  76 static inline unsigned long reqd_free_pages(void)
  77 {
  78         return low_free_pages() / 2;
  79 }
  80
  81 struct swap_map_page {
  82         sector_t entries[MAP_PAGE_ENTRIES];
  83         sector_t next_swap;
  84 };
  85
  86 struct swap_map_page_list {
  87         struct swap_map_page *map;
  88         struct swap_map_page_list *next;
  89 };
  90
  91 /*
  92  *      The swap_map_handle structure is used for handling swap in
  93  *      a file-alike way
  94  */
  95
  96 struct swap_map_handle {
  97         struct swap_map_page *cur;
  98         struct swap_map_page_list *maps;
  99         sector_t cur_swap;
 100         sector_t first_sector;
 101         unsigned int k;
 102         unsigned long reqd_free_pages;
 103         u32 crc32;
 104 };
 105
 106 struct swsusp_header {
 107         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 108                       sizeof(u32) - sizeof(u32)];
 109         u32     hw_sig;
 110         u32     crc32;
 111         sector_t image;
 112         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 113         char    orig_sig[10];
 114         char    sig[10];
 115 } __packed;
 116
 117 static struct swsusp_header *swsusp_header;
 118
 119 /*
 120  *      The following functions are used for tracing the allocated
 121  *      swap pages, so that they can be freed in case of an error.
 122  */
 123
 124 struct swsusp_extent {
 125         struct rb_node node;
 126         unsigned long start;
 127         unsigned long end;
 128 };
 129
 130 static struct rb_root swsusp_extents = RB_ROOT;
 131
 132 static int swsusp_extents_insert(unsigned long swap_offset)
 133 {
 134         struct rb_node **new = &(swsusp_extents.rb_node);
 135         struct rb_node *parent = NULL;
 136         struct swsusp_extent *ext;
 137
 138         /* Figure out where to put the new node */
 139         while (*new) {
 140                 ext = rb_entry(*new, struct swsusp_extent, node);
 141                 parent = *new;
 142                 if (swap_offset < ext->start) {
 143                         /* Try to merge */
 144                         if (swap_offset == ext->start - 1) {
 145                                 ext->start--;
 146                                 return 0;
 147                         }
 148                         new = &((*new)->rb_left);
 149                 } else if (swap_offset > ext->end) {
 150                         /* Try to merge */
 151                         if (swap_offset == ext->end + 1) {
 152                                 ext->end++;
 153                                 return 0;
 154                         }
 155                         new = &((*new)->rb_right);
 156                 } else {
 157                         /* It already is in the tree */
 158                         return -EINVAL;
 159                 }
 160         }
 161         /* Add the new node and rebalance the tree. */
 162         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 163         if (!ext)
 164                 return -ENOMEM;
 165
 166         ext->start = swap_offset;
 167         ext->end = swap_offset;
 168         rb_link_node(&ext->node, parent, new);
 169         rb_insert_color(&ext->node, &swsusp_extents);
 170         return 0;
 171 }
 172
 173 /*
 174  *      alloc_swapdev_block - allocate a swap page and register that it has
 175  *      been allocated, so that it can be freed in case of an error.
 176  */
 177
 178 sector_t alloc_swapdev_block(int swap)
 179 {
 180         unsigned long offset;
 181
 182         offset = swp_offset(get_swap_page_of_type(swap));
 183         if (offset) {
 184                 if (swsusp_extents_insert(offset))
 185                         swap_free(swp_entry(swap, offset));
 186                 else
 187                         return swapdev_block(swap, offset);
 188         }
 189         return 0;
 190 }
 191
 192 /*
 193  *      free_all_swap_pages - free swap pages allocated for saving image data.
 194  *      It also frees the extents used to register which swap entries had been
 195  *      allocated.
 196  */
 197
 198 void free_all_swap_pages(int swap)
 199 {
 200         struct rb_node *node;
 201
 202         while ((node = swsusp_extents.rb_node)) {
 203                 struct swsusp_extent *ext;
 204                 unsigned long offset;
 205
 206                 ext = rb_entry(node, struct swsusp_extent, node);
 207                 rb_erase(node, &swsusp_extents);
 208                 for (offset = ext->start; offset <= ext->end; offset++)
 209                         swap_free(swp_entry(swap, offset));
 210
 211                 kfree(ext);
 212         }
 213 }
 214
 215 int swsusp_swap_in_use(void)
 216 {
 217         return (swsusp_extents.rb_node != NULL);
 218 }
 219
 220 /*
 221  * General things
 222  */
 223
 224 static unsigned short root_swap = 0xffff;
 225 static struct file *hib_resume_bdev_file;
 226
 227 struct hib_bio_batch {
 228         atomic_t                count;
 229         wait_queue_head_t       wait;
 230         blk_status_t            error;
 231         struct blk_plug         plug;
 232 };
 233
 234 static void hib_init_batch(struct hib_bio_batch *hb)
 235 {
 236         atomic_set(&hb->count, 0);
 237         init_waitqueue_head(&hb->wait);
 238         hb->error = BLK_STS_OK;
 239         blk_start_plug(&hb->plug);
 240 }
 241
 242 static void hib_finish_batch(struct hib_bio_batch *hb)
 243 {
 244         blk_finish_plug(&hb->plug);
 245 }
 246
 247 static void hib_end_io(struct bio *bio)
 248 {
 249         struct hib_bio_batch *hb = bio->bi_private;
 250         struct page *page = bio_first_page_all(bio);
 251
 252         if (bio->bi_status) {
 253                 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
 254                          MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 255                          (unsigned long long)bio->bi_iter.bi_sector);
 256         }
 257
 258         if (bio_data_dir(bio) == WRITE)
 259                 put_page(page);
 260         else if (clean_pages_on_read)
 261                 flush_icache_range((unsigned long)page_address(page),
 262                                    (unsigned long)page_address(page) + PAGE_SIZE);
 263
 264         if (bio->bi_status && !hb->error)
 265                 hb->error = bio->bi_status;
 266         if (atomic_dec_and_test(&hb->count))
 267                 wake_up(&hb->wait);
 268
 269         bio_put(bio);
 270 }
 271
 272 static int hib_submit_io(blk_opf_t opf, pgoff_t page_off, void *addr,
 273                          struct hib_bio_batch *hb)
 274 {
 275         struct page *page = virt_to_page(addr);
 276         struct bio *bio;
 277         int error = 0;
 278
 279         bio = bio_alloc(file_bdev(hib_resume_bdev_file), 1, opf,
 280                         GFP_NOIO | __GFP_HIGH);
 281         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 282
 283         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 284                 pr_err("Adding page to bio failed at %llu\n",
 285                        (unsigned long long)bio->bi_iter.bi_sector);
 286                 bio_put(bio);
 287                 return -EFAULT;
 288         }
 289
 290         if (hb) {
 291                 bio->bi_end_io = hib_end_io;
 292                 bio->bi_private = hb;
 293                 atomic_inc(&hb->count);
 294                 submit_bio(bio);
 295         } else {
 296                 error = submit_bio_wait(bio);
 297                 bio_put(bio);
 298         }
 299
 300         return error;
 301 }
 302
 303 static int hib_wait_io(struct hib_bio_batch *hb)
 304 {
 305         /*
 306          * We are relying on the behavior of blk_plug that a thread with
 307          * a plug will flush the plug list before sleeping.
 308          */
 309         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 310         return blk_status_to_errno(hb->error);
 311 }
 312
 313 /*
 314  * Saving part
 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, swsusp_resume_block, swsusp_header, NULL);
 321         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 322             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 323                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 324                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 325                 swsusp_header->image = handle->first_sector;
 326                 if (swsusp_hardware_signature) {
 327                         swsusp_header->hw_sig = swsusp_hardware_signature;
 328                         flags |= SF_HW_SIG;
 329                 }
 330                 swsusp_header->flags = flags;
 331                 if (flags & SF_CRC32_MODE)
 332                         swsusp_header->crc32 = handle->crc32;
 333                 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
 334                                       swsusp_resume_block, swsusp_header, NULL);
 335         } else {
 336                 pr_err("Swap header not found!\n");
 337                 error = -ENODEV;
 338         }
 339         return error;
 340 }
 341
 342 /**
 343  *      swsusp_swap_check - check if the resume device is a swap device
 344  *      and get its index (if so)
 345  *
 346  *      This is called before saving image
 347  */
 348 static int swsusp_swap_check(void)
 349 {
 350         int res;
 351
 352         if (swsusp_resume_device)
 353                 res = swap_type_of(swsusp_resume_device, swsusp_resume_block);
 354         else
 355                 res = find_first_swap(&swsusp_resume_device);
 356         if (res < 0)
 357                 return res;
 358         root_swap = res;
 359
 360         hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
 361                         BLK_OPEN_WRITE, NULL, NULL);
 362         if (IS_ERR(hib_resume_bdev_file))
 363                 return PTR_ERR(hib_resume_bdev_file);
 364
 365         res = set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
 366         if (res < 0)
 367                 fput(hib_resume_bdev_file);
 368
 369         return res;
 370 }
 371
 372 /**
 373  *      write_page - Write one page to given swap location.
 374  *      @buf:           Address we're writing.
 375  *      @offset:        Offset of the swap page we're writing to.
 376  *      @hb:            bio completion batch
 377  */
 378
 379 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 380 {
 381         void *src;
 382         int ret;
 383
 384         if (!offset)
 385                 return -ENOSPC;
 386
 387         if (hb) {
 388                 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 389                                               __GFP_NORETRY);
 390                 if (src) {
 391                         copy_page(src, buf);
 392                 } else {
 393                         ret = hib_wait_io(hb); /* Free pages */
 394                         if (ret)
 395                                 return ret;
 396                         src = (void *)__get_free_page(GFP_NOIO |
 397                                                       __GFP_NOWARN |
 398                                                       __GFP_NORETRY);
 399                         if (src) {
 400                                 copy_page(src, buf);
 401                         } else {
 402                                 WARN_ON_ONCE(1);
 403                                 hb = NULL;      /* Go synchronous */
 404                                 src = buf;
 405                         }
 406                 }
 407         } else {
 408                 src = buf;
 409         }
 410         return hib_submit_io(REQ_OP_WRITE | REQ_SYNC, offset, src, hb);
 411 }
 412
 413 static void release_swap_writer(struct swap_map_handle *handle)
 414 {
 415         if (handle->cur)
 416                 free_page((unsigned long)handle->cur);
 417         handle->cur = NULL;
 418 }
 419
 420 static int get_swap_writer(struct swap_map_handle *handle)
 421 {
 422         int ret;
 423
 424         ret = swsusp_swap_check();
 425         if (ret) {
 426                 if (ret != -ENOSPC)
 427                         pr_err("Cannot find swap device, try swapon -a\n");
 428                 return ret;
 429         }
 430         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 431         if (!handle->cur) {
 432                 ret = -ENOMEM;
 433                 goto err_close;
 434         }
 435         handle->cur_swap = alloc_swapdev_block(root_swap);
 436         if (!handle->cur_swap) {
 437                 ret = -ENOSPC;
 438                 goto err_rel;
 439         }
 440         handle->k = 0;
 441         handle->reqd_free_pages = reqd_free_pages();
 442         handle->first_sector = handle->cur_swap;
 443         return 0;
 444 err_rel:
 445         release_swap_writer(handle);
 446 err_close:
 447         swsusp_close();
 448         return ret;
 449 }
 450
 451 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 452                 struct hib_bio_batch *hb)
 453 {
 454         int error;
 455         sector_t offset;
 456
 457         if (!handle->cur)
 458                 return -EINVAL;
 459         offset = alloc_swapdev_block(root_swap);
 460         error = write_page(buf, offset, hb);
 461         if (error)
 462                 return error;
 463         handle->cur->entries[handle->k++] = offset;
 464         if (handle->k >= MAP_PAGE_ENTRIES) {
 465                 offset = alloc_swapdev_block(root_swap);
 466                 if (!offset)
 467                         return -ENOSPC;
 468                 handle->cur->next_swap = offset;
 469                 error = write_page(handle->cur, handle->cur_swap, hb);
 470                 if (error)
 471                         goto out;
 472                 clear_page(handle->cur);
 473                 handle->cur_swap = offset;
 474                 handle->k = 0;
 475
 476                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 477                         error = hib_wait_io(hb);
 478                         if (error)
 479                                 goto out;
 480                         /*
 481                          * Recalculate the number of required free pages, to
 482                          * make sure we never take more than half.
 483                          */
 484                         handle->reqd_free_pages = reqd_free_pages();
 485                 }
 486         }
 487  out:
 488         return error;
 489 }
 490
 491 static int flush_swap_writer(struct swap_map_handle *handle)
 492 {
 493         if (handle->cur && handle->cur_swap)
 494                 return write_page(handle->cur, handle->cur_swap, NULL);
 495         else
 496                 return -EINVAL;
 497 }
 498
 499 static int swap_writer_finish(struct swap_map_handle *handle,
 500                 unsigned int flags, int error)
 501 {
 502         if (!error) {
 503                 pr_info("S");
 504                 error = mark_swapfiles(handle, flags);
 505                 pr_cont("|\n");
 506                 flush_swap_writer(handle);
 507         }
 508
 509         if (error)
 510                 free_all_swap_pages(root_swap);
 511         release_swap_writer(handle);
 512         swsusp_close();
 513
 514         return error;
 515 }
 516
 517 /* We need to remember how much compressed data we need to read. */
 518 #define LZO_HEADER      sizeof(size_t)
 519
 520 /* Number of pages/bytes we'll compress at one time. */
 521 #define LZO_UNC_PAGES   32
 522 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 523
 524 /* Number of pages/bytes we need for compressed data (worst case). */
 525 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 526                                      LZO_HEADER, PAGE_SIZE)
 527 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 528
 529 /* Maximum number of threads for compression/decompression. */
 530 #define LZO_THREADS     3
 531
 532 /* Minimum/maximum number of pages for read buffering. */
 533 #define LZO_MIN_RD_PAGES        1024
 534 #define LZO_MAX_RD_PAGES        8192
 535
 536
 537 /**
 538  *      save_image - save the suspend image data
 539  */
 540
 541 static int save_image(struct swap_map_handle *handle,
 542                       struct snapshot_handle *snapshot,
 543                       unsigned int nr_to_write)
 544 {
 545         unsigned int m;
 546         int ret;
 547         int nr_pages;
 548         int err2;
 549         struct hib_bio_batch hb;
 550         ktime_t start;
 551         ktime_t stop;
 552
 553         hib_init_batch(&hb);
 554
 555         pr_info("Saving image data pages (%u pages)...\n",
 556                 nr_to_write);
 557         m = nr_to_write / 10;
 558         if (!m)
 559                 m = 1;
 560         nr_pages = 0;
 561         start = ktime_get();
 562         while (1) {
 563                 ret = snapshot_read_next(snapshot);
 564                 if (ret <= 0)
 565                         break;
 566                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 567                 if (ret)
 568                         break;
 569                 if (!(nr_pages % m))
 570                         pr_info("Image saving progress: %3d%%\n",
 571                                 nr_pages / m * 10);
 572                 nr_pages++;
 573         }
 574         err2 = hib_wait_io(&hb);
 575         hib_finish_batch(&hb);
 576         stop = ktime_get();
 577         if (!ret)
 578                 ret = err2;
 579         if (!ret)
 580                 pr_info("Image saving done\n");
 581         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 582         return ret;
 583 }
 584
 585 /*
 586  * Structure used for CRC32.
 587  */
 588 struct crc_data {
 589         struct task_struct *thr;                  /* thread */
 590         atomic_t ready;                           /* ready to start flag */
 591         atomic_t stop;                            /* ready to stop flag */
 592         unsigned run_threads;                     /* nr current threads */
 593         wait_queue_head_t go;                     /* start crc update */
 594         wait_queue_head_t done;                   /* crc update done */
 595         u32 *crc32;                               /* points to handle's crc32 */
 596         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 597         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 598 };
 599
 600 /*
 601  * CRC32 update function that runs in its own thread.
 602  */
 603 static int crc32_threadfn(void *data)
 604 {
 605         struct crc_data *d = data;
 606         unsigned i;
 607
 608         while (1) {
 609                 wait_event(d->go, atomic_read_acquire(&d->ready) ||
 610                                   kthread_should_stop());
 611                 if (kthread_should_stop()) {
 612                         d->thr = NULL;
 613                         atomic_set_release(&d->stop, 1);
 614                         wake_up(&d->done);
 615                         break;
 616                 }
 617                 atomic_set(&d->ready, 0);
 618
 619                 for (i = 0; i < d->run_threads; i++)
 620                         *d->crc32 = crc32_le(*d->crc32,
 621                                              d->unc[i], *d->unc_len[i]);
 622                 atomic_set_release(&d->stop, 1);
 623                 wake_up(&d->done);
 624         }
 625         return 0;
 626 }
 627 /*
 628  * Structure used for LZO data compression.
 629  */
 630 struct cmp_data {
 631         struct task_struct *thr;                  /* thread */
 632         atomic_t ready;                           /* ready to start flag */
 633         atomic_t stop;                            /* ready to stop flag */
 634         int ret;                                  /* return code */
 635         wait_queue_head_t go;                     /* start compression */
 636         wait_queue_head_t done;                   /* compression done */
 637         size_t unc_len;                           /* uncompressed length */
 638         size_t cmp_len;                           /* compressed length */
 639         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 640         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 641         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 642 };
 643
 644 /*
 645  * Compression function that runs in its own thread.
 646  */
 647 static int lzo_compress_threadfn(void *data)
 648 {
 649         struct cmp_data *d = data;
 650
 651         while (1) {
 652                 wait_event(d->go, atomic_read_acquire(&d->ready) ||
 653                                   kthread_should_stop());
 654                 if (kthread_should_stop()) {
 655                         d->thr = NULL;
 656                         d->ret = -1;
 657                         atomic_set_release(&d->stop, 1);
 658                         wake_up(&d->done);
 659                         break;
 660                 }
 661                 atomic_set(&d->ready, 0);
 662
 663                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 664                                           d->cmp + LZO_HEADER, &d->cmp_len,
 665                                           d->wrk);
 666                 atomic_set_release(&d->stop, 1);
 667                 wake_up(&d->done);
 668         }
 669         return 0;
 670 }
 671
 672 /**
 673  * save_image_lzo - Save the suspend image data compressed with LZO.
 674  * @handle: Swap map handle to use for saving the image.
 675  * @snapshot: Image to read data from.
 676  * @nr_to_write: Number of pages to save.
 677  */
 678 static int save_image_lzo(struct swap_map_handle *handle,
 679                           struct snapshot_handle *snapshot,
 680                           unsigned int nr_to_write)
 681 {
 682         unsigned int m;
 683         int ret = 0;
 684         int nr_pages;
 685         int err2;
 686         struct hib_bio_batch hb;
 687         ktime_t start;
 688         ktime_t stop;
 689         size_t off;
 690         unsigned thr, run_threads, nr_threads;
 691         unsigned char *page = NULL;
 692         struct cmp_data *data = NULL;
 693         struct crc_data *crc = NULL;
 694
 695         hib_init_batch(&hb);
 696
 697         /*
 698          * We'll limit the number of threads for compression to limit memory
 699          * footprint.
 700          */
 701         nr_threads = num_online_cpus() - 1;
 702         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 703
 704         page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 705         if (!page) {
 706                 pr_err("Failed to allocate LZO page\n");
 707                 ret = -ENOMEM;
 708                 goto out_clean;
 709         }
 710
 711         data = vzalloc(array_size(nr_threads, sizeof(*data)));
 712         if (!data) {
 713                 pr_err("Failed to allocate LZO data\n");
 714                 ret = -ENOMEM;
 715                 goto out_clean;
 716         }
 717
 718         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
 719         if (!crc) {
 720                 pr_err("Failed to allocate crc\n");
 721                 ret = -ENOMEM;
 722                 goto out_clean;
 723         }
 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_release(&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_release(&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_acquire(&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_acquire(&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 available 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-like 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, 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, 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  * Decompression 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_acquire(&d->ready) ||
1136                                   kthread_should_stop());
1137                 if (kthread_should_stop()) {
1138                         d->thr = NULL;
1139                         d->ret = -1;
1140                         atomic_set_release(&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_release(&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 = vzalloc(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
1208         crc = kzalloc(sizeof(*crc), GFP_KERNEL);
1209         if (!crc) {
1210                 pr_err("Failed to allocate crc\n");
1211                 ret = -ENOMEM;
1212                 goto out_clean;
1213         }
1214
1215         clean_pages_on_decompress = true;
1216
1217         /*
1218          * Start the decompression threads.
1219          */
1220         for (thr = 0; thr < nr_threads; thr++) {
1221                 init_waitqueue_head(&data[thr].go);
1222                 init_waitqueue_head(&data[thr].done);
1223
1224                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1225                                             &data[thr],
1226                                             "image_decompress/%u", thr);
1227                 if (IS_ERR(data[thr].thr)) {
1228                         data[thr].thr = NULL;
1229                         pr_err("Cannot start decompression threads\n");
1230                         ret = -ENOMEM;
1231                         goto out_clean;
1232                 }
1233         }
1234
1235         /*
1236          * Start the CRC32 thread.
1237          */
1238         init_waitqueue_head(&crc->go);
1239         init_waitqueue_head(&crc->done);
1240
1241         handle->crc32 = 0;
1242         crc->crc32 = &handle->crc32;
1243         for (thr = 0; thr < nr_threads; thr++) {
1244                 crc->unc[thr] = data[thr].unc;
1245                 crc->unc_len[thr] = &data[thr].unc_len;
1246         }
1247
1248         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1249         if (IS_ERR(crc->thr)) {
1250                 crc->thr = NULL;
1251                 pr_err("Cannot start CRC32 thread\n");
1252                 ret = -ENOMEM;
1253                 goto out_clean;
1254         }
1255
1256         /*
1257          * Set the number of pages for read buffering.
1258          * This is complete guesswork, because we'll only know the real
1259          * picture once prepare_image() is called, which is much later on
1260          * during the image load phase. We'll assume the worst case and
1261          * say that none of the image pages are from high memory.
1262          */
1263         if (low_free_pages() > snapshot_get_image_size())
1264                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1265         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1266
1267         for (i = 0; i < read_pages; i++) {
1268                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1269                                                   GFP_NOIO | __GFP_HIGH :
1270                                                   GFP_NOIO | __GFP_NOWARN |
1271                                                   __GFP_NORETRY);
1272
1273                 if (!page[i]) {
1274                         if (i < LZO_CMP_PAGES) {
1275                                 ring_size = i;
1276                                 pr_err("Failed to allocate LZO pages\n");
1277                                 ret = -ENOMEM;
1278                                 goto out_clean;
1279                         } else {
1280                                 break;
1281                         }
1282                 }
1283         }
1284         want = ring_size = i;
1285
1286         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1287         pr_info("Loading and decompressing image data (%u pages)...\n",
1288                 nr_to_read);
1289         m = nr_to_read / 10;
1290         if (!m)
1291                 m = 1;
1292         nr_pages = 0;
1293         start = ktime_get();
1294
1295         ret = snapshot_write_next(snapshot);
1296         if (ret <= 0)
1297                 goto out_finish;
1298
1299         for(;;) {
1300                 for (i = 0; !eof && i < want; i++) {
1301                         ret = swap_read_page(handle, page[ring], &hb);
1302                         if (ret) {
1303                                 /*
1304                                  * On real read error, finish. On end of data,
1305                                  * set EOF flag and just exit the read loop.
1306                                  */
1307                                 if (handle->cur &&
1308                                     handle->cur->entries[handle->k]) {
1309                                         goto out_finish;
1310                                 } else {
1311                                         eof = 1;
1312                                         break;
1313                                 }
1314                         }
1315                         if (++ring >= ring_size)
1316                                 ring = 0;
1317                 }
1318                 asked += i;
1319                 want -= i;
1320
1321                 /*
1322                  * We are out of data, wait for some more.
1323                  */
1324                 if (!have) {
1325                         if (!asked)
1326                                 break;
1327
1328                         ret = hib_wait_io(&hb);
1329                         if (ret)
1330                                 goto out_finish;
1331                         have += asked;
1332                         asked = 0;
1333                         if (eof)
1334                                 eof = 2;
1335                 }
1336
1337                 if (crc->run_threads) {
1338                         wait_event(crc->done, atomic_read_acquire(&crc->stop));
1339                         atomic_set(&crc->stop, 0);
1340                         crc->run_threads = 0;
1341                 }
1342
1343                 for (thr = 0; have && thr < nr_threads; thr++) {
1344                         data[thr].cmp_len = *(size_t *)page[pg];
1345                         if (unlikely(!data[thr].cmp_len ||
1346                                      data[thr].cmp_len >
1347                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1348                                 pr_err("Invalid LZO compressed length\n");
1349                                 ret = -1;
1350                                 goto out_finish;
1351                         }
1352
1353                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1354                                             PAGE_SIZE);
1355                         if (need > have) {
1356                                 if (eof > 1) {
1357                                         ret = -1;
1358                                         goto out_finish;
1359                                 }
1360                                 break;
1361                         }
1362
1363                         for (off = 0;
1364                              off < LZO_HEADER + data[thr].cmp_len;
1365                              off += PAGE_SIZE) {
1366                                 memcpy(data[thr].cmp + off,
1367                                        page[pg], PAGE_SIZE);
1368                                 have--;
1369                                 want++;
1370                                 if (++pg >= ring_size)
1371                                         pg = 0;
1372                         }
1373
1374                         atomic_set_release(&data[thr].ready, 1);
1375                         wake_up(&data[thr].go);
1376                 }
1377
1378                 /*
1379                  * Wait for more data while we are decompressing.
1380                  */
1381                 if (have < LZO_CMP_PAGES && asked) {
1382                         ret = hib_wait_io(&hb);
1383                         if (ret)
1384                                 goto out_finish;
1385                         have += asked;
1386                         asked = 0;
1387                         if (eof)
1388                                 eof = 2;
1389                 }
1390
1391                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1392                         wait_event(data[thr].done,
1393                                 atomic_read_acquire(&data[thr].stop));
1394                         atomic_set(&data[thr].stop, 0);
1395
1396                         ret = data[thr].ret;
1397
1398                         if (ret < 0) {
1399                                 pr_err("LZO decompression failed\n");
1400                                 goto out_finish;
1401                         }
1402
1403                         if (unlikely(!data[thr].unc_len ||
1404                                      data[thr].unc_len > LZO_UNC_SIZE ||
1405                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1406                                 pr_err("Invalid LZO uncompressed length\n");
1407                                 ret = -1;
1408                                 goto out_finish;
1409                         }
1410
1411                         for (off = 0;
1412                              off < data[thr].unc_len; off += PAGE_SIZE) {
1413                                 memcpy(data_of(*snapshot),
1414                                        data[thr].unc + off, PAGE_SIZE);
1415
1416                                 if (!(nr_pages % m))
1417                                         pr_info("Image loading progress: %3d%%\n",
1418                                                 nr_pages / m * 10);
1419                                 nr_pages++;
1420
1421                                 ret = snapshot_write_next(snapshot);
1422                                 if (ret <= 0) {
1423                                         crc->run_threads = thr + 1;
1424                                         atomic_set_release(&crc->ready, 1);
1425                                         wake_up(&crc->go);
1426                                         goto out_finish;
1427                                 }
1428                         }
1429                 }
1430
1431                 crc->run_threads = thr;
1432                 atomic_set_release(&crc->ready, 1);
1433                 wake_up(&crc->go);
1434         }
1435
1436 out_finish:
1437         if (crc->run_threads) {
1438                 wait_event(crc->done, atomic_read_acquire(&crc->stop));
1439                 atomic_set(&crc->stop, 0);
1440         }
1441         stop = ktime_get();
1442         if (!ret) {
1443                 pr_info("Image loading done\n");
1444                 snapshot_write_finalize(snapshot);
1445                 if (!snapshot_image_loaded(snapshot))
1446                         ret = -ENODATA;
1447                 if (!ret) {
1448                         if (swsusp_header->flags & SF_CRC32_MODE) {
1449                                 if(handle->crc32 != swsusp_header->crc32) {
1450                                         pr_err("Invalid image CRC32!\n");
1451                                         ret = -ENODATA;
1452                                 }
1453                         }
1454                 }
1455         }
1456         swsusp_show_speed(start, stop, nr_to_read, "Read");
1457 out_clean:
1458         hib_finish_batch(&hb);
1459         for (i = 0; i < ring_size; i++)
1460                 free_page((unsigned long)page[i]);
1461         if (crc) {
1462                 if (crc->thr)
1463                         kthread_stop(crc->thr);
1464                 kfree(crc);
1465         }
1466         if (data) {
1467                 for (thr = 0; thr < nr_threads; thr++)
1468                         if (data[thr].thr)
1469                                 kthread_stop(data[thr].thr);
1470                 vfree(data);
1471         }
1472         vfree(page);
1473
1474         return ret;
1475 }
1476
1477 /**
1478  *      swsusp_read - read the hibernation image.
1479  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1480  *                be written into this memory location
1481  */
1482
1483 int swsusp_read(unsigned int *flags_p)
1484 {
1485         int error;
1486         struct swap_map_handle handle;
1487         struct snapshot_handle snapshot;
1488         struct swsusp_info *header;
1489
1490         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1491         error = snapshot_write_next(&snapshot);
1492         if (error < (int)PAGE_SIZE)
1493                 return error < 0 ? error : -EFAULT;
1494         header = (struct swsusp_info *)data_of(snapshot);
1495         error = get_swap_reader(&handle, flags_p);
1496         if (error)
1497                 goto end;
1498         if (!error)
1499                 error = swap_read_page(&handle, header, NULL);
1500         if (!error) {
1501                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1502                         load_image(&handle, &snapshot, header->pages - 1) :
1503                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1504         }
1505         swap_reader_finish(&handle);
1506 end:
1507         if (!error)
1508                 pr_debug("Image successfully loaded\n");
1509         else
1510                 pr_debug("Error %d resuming\n", error);
1511         return error;
1512 }
1513
1514 static void *swsusp_holder;
1515
1516 /**
1517  * swsusp_check - Open the resume device and check for the swsusp signature.
1518  * @exclusive: Open the resume device exclusively.
1519  */
1520
1521 int swsusp_check(bool exclusive)
1522 {
1523         void *holder = exclusive ? &swsusp_holder : NULL;
1524         int error;
1525
1526         hib_resume_bdev_file = bdev_file_open_by_dev(swsusp_resume_device,
1527                                 BLK_OPEN_READ, holder, NULL);
1528         if (!IS_ERR(hib_resume_bdev_file)) {
1529                 set_blocksize(file_bdev(hib_resume_bdev_file), PAGE_SIZE);
1530                 clear_page(swsusp_header);
1531                 error = hib_submit_io(REQ_OP_READ, 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                 if (!error && swsusp_header->flags & SF_HW_SIG &&
1546                     swsusp_header->hw_sig != swsusp_hardware_signature) {
1547                         pr_info("Suspend image hardware signature mismatch (%08x now %08x); aborting resume.\n",
1548                                 swsusp_header->hw_sig, swsusp_hardware_signature);
1549                         error = -EINVAL;
1550                 }
1551
1552 put:
1553                 if (error)
1554                         fput(hib_resume_bdev_file);
1555                 else
1556                         pr_debug("Image signature found, resuming\n");
1557         } else {
1558                 error = PTR_ERR(hib_resume_bdev_file);
1559         }
1560
1561         if (error)
1562                 pr_debug("Image not found (code %d)\n", error);
1563
1564         return error;
1565 }
1566
1567 /**
1568  * swsusp_close - close resume device.
1569  */
1570
1571 void swsusp_close(void)
1572 {
1573         if (IS_ERR(hib_resume_bdev_file)) {
1574                 pr_debug("Image device not initialised\n");
1575                 return;
1576         }
1577
1578         fput(hib_resume_bdev_file);
1579 }
1580
1581 /**
1582  *      swsusp_unmark - Unmark swsusp signature in the resume device
1583  */
1584
1585 #ifdef CONFIG_SUSPEND
1586 int swsusp_unmark(void)
1587 {
1588         int error;
1589
1590         hib_submit_io(REQ_OP_READ, swsusp_resume_block,
1591                         swsusp_header, NULL);
1592         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1593                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1594                 error = hib_submit_io(REQ_OP_WRITE | REQ_SYNC,
1595                                         swsusp_resume_block,
1596                                         swsusp_header, NULL);
1597         } else {
1598                 pr_err("Cannot find swsusp signature!\n");
1599                 error = -ENODEV;
1600         }
1601
1602         /*
1603          * We just returned from suspend, we don't need the image any more.
1604          */
1605         free_all_swap_pages(root_swap);
1606
1607         return error;
1608 }
1609 #endif
1610
1611 static int __init swsusp_header_init(void)
1612 {
1613         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1614         if (!swsusp_header)
1615                 panic("Could not allocate memory for swsusp_header\n");
1616         return 0;
1617 }
1618
1619 core_initcall(swsusp_header_init);