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