kernel/power/swap.c

   1 /*
   2  * linux/kernel/power/swap.c
   3  *
   4  * This file provides functions for reading the suspend image from
   5  * and writing it to a swap partition.
   6  *
   7  * Copyright (C) 1998,2001-2005 Pavel Machek <[email protected]>
   8  * Copyright (C) 2006 Rafael J. Wysocki <[email protected]>
   9  * Copyright (C) 2010-2012 Bojan Smojver <[email protected]>
  10  *
  11  * This file is released under the GPLv2.
  12  *
  13  */
  14
  15 #include <linux/module.h>
  16 #include <linux/file.h>
  17 #include <linux/delay.h>
  18 #include <linux/bitops.h>
  19 #include <linux/genhd.h>
  20 #include <linux/device.h>
  21 #include <linux/bio.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/swap.h>
  24 #include <linux/swapops.h>
  25 #include <linux/pm.h>
  26 #include <linux/slab.h>
  27 #include <linux/lzo.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/cpumask.h>
  30 #include <linux/atomic.h>
  31 #include <linux/kthread.h>
  32 #include <linux/crc32.h>
  33 #include <linux/ktime.h>
  34
  35 #include "power.h"
  36
  37 #define HIBERNATE_SIG   "S1SUSPEND"
  38
  39 /*
  40  * When reading an {un,}compressed image, we may restore pages in place,
  41  * in which case some architectures need these pages cleaning before they
  42  * can be executed. We don't know which pages these may be, so clean the lot.
  43  */
  44 static bool clean_pages_on_read;
  45 static bool clean_pages_on_decompress;
  46
  47 /*
  48  *      The swap map is a data structure used for keeping track of each page
  49  *      written to a swap partition.  It consists of many swap_map_page
  50  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  51  *      These structures are stored on the swap and linked together with the
  52  *      help of the .next_swap member.
  53  *
  54  *      The swap map is created during suspend.  The swap map pages are
  55  *      allocated and populated one at a time, so we only need one memory
  56  *      page to set up the entire structure.
  57  *
  58  *      During resume we pick up all swap_map_page structures into a list.
  59  */
  60
  61 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  62
  63 /*
  64  * Number of free pages that are not high.
  65  */
  66 static inline unsigned long low_free_pages(void)
  67 {
  68         return nr_free_pages() - nr_free_highpages();
  69 }
  70
  71 /*
  72  * Number of pages required to be kept free while writing the image. Always
  73  * half of all available low pages before the writing starts.
  74  */
  75 static inline unsigned long reqd_free_pages(void)
  76 {
  77         return low_free_pages() / 2;
  78 }
  79
  80 struct swap_map_page {
  81         sector_t entries[MAP_PAGE_ENTRIES];
  82         sector_t next_swap;
  83 };
  84
  85 struct swap_map_page_list {
  86         struct swap_map_page *map;
  87         struct swap_map_page_list *next;
  88 };
  89
  90 /**
  91  *      The swap_map_handle structure is used for handling swap in
  92  *      a file-alike way
  93  */
  94
  95 struct swap_map_handle {
  96         struct swap_map_page *cur;
  97         struct swap_map_page_list *maps;
  98         sector_t cur_swap;
  99         sector_t first_sector;
 100         unsigned int k;
 101         unsigned long reqd_free_pages;
 102         u32 crc32;
 103 };
 104
 105 struct swsusp_header {
 106         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 107                       sizeof(u32)];
 108         u32     crc32;
 109         sector_t image;
 110         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 111         char    orig_sig[10];
 112         char    sig[10];
 113 } __packed;
 114
 115 static struct swsusp_header *swsusp_header;
 116
 117 /**
 118  *      The following functions are used for tracing the allocated
 119  *      swap pages, so that they can be freed in case of an error.
 120  */
 121
 122 struct swsusp_extent {
 123         struct rb_node node;
 124         unsigned long start;
 125         unsigned long end;
 126 };
 127
 128 static struct rb_root swsusp_extents = RB_ROOT;
 129
 130 static int swsusp_extents_insert(unsigned long swap_offset)
 131 {
 132         struct rb_node **new = &(swsusp_extents.rb_node);
 133         struct rb_node *parent = NULL;
 134         struct swsusp_extent *ext;
 135
 136         /* Figure out where to put the new node */
 137         while (*new) {
 138                 ext = rb_entry(*new, struct swsusp_extent, node);
 139                 parent = *new;
 140                 if (swap_offset < ext->start) {
 141                         /* Try to merge */
 142                         if (swap_offset == ext->start - 1) {
 143                                 ext->start--;
 144                                 return 0;
 145                         }
 146                         new = &((*new)->rb_left);
 147                 } else if (swap_offset > ext->end) {
 148                         /* Try to merge */
 149                         if (swap_offset == ext->end + 1) {
 150                                 ext->end++;
 151                                 return 0;
 152                         }
 153                         new = &((*new)->rb_right);
 154                 } else {
 155                         /* It already is in the tree */
 156                         return -EINVAL;
 157                 }
 158         }
 159         /* Add the new node and rebalance the tree. */
 160         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 161         if (!ext)
 162                 return -ENOMEM;
 163
 164         ext->start = swap_offset;
 165         ext->end = swap_offset;
 166         rb_link_node(&ext->node, parent, new);
 167         rb_insert_color(&ext->node, &swsusp_extents);
 168         return 0;
 169 }
 170
 171 /**
 172  *      alloc_swapdev_block - allocate a swap page and register that it has
 173  *      been allocated, so that it can be freed in case of an error.
 174  */
 175
 176 sector_t alloc_swapdev_block(int swap)
 177 {
 178         unsigned long offset;
 179
 180         offset = swp_offset(get_swap_page_of_type(swap));
 181         if (offset) {
 182                 if (swsusp_extents_insert(offset))
 183                         swap_free(swp_entry(swap, offset));
 184                 else
 185                         return swapdev_block(swap, offset);
 186         }
 187         return 0;
 188 }
 189
 190 /**
 191  *      free_all_swap_pages - free swap pages allocated for saving image data.
 192  *      It also frees the extents used to register which swap entries had been
 193  *      allocated.
 194  */
 195
 196 void free_all_swap_pages(int swap)
 197 {
 198         struct rb_node *node;
 199
 200         while ((node = swsusp_extents.rb_node)) {
 201                 struct swsusp_extent *ext;
 202                 unsigned long offset;
 203
 204                 ext = container_of(node, struct swsusp_extent, node);
 205                 rb_erase(node, &swsusp_extents);
 206                 for (offset = ext->start; offset <= ext->end; offset++)
 207                         swap_free(swp_entry(swap, offset));
 208
 209                 kfree(ext);
 210         }
 211 }
 212
 213 int swsusp_swap_in_use(void)
 214 {
 215         return (swsusp_extents.rb_node != NULL);
 216 }
 217
 218 /*
 219  * General things
 220  */
 221
 222 static unsigned short root_swap = 0xffff;
 223 static struct block_device *hib_resume_bdev;
 224
 225 struct hib_bio_batch {
 226         atomic_t                count;
 227         wait_queue_head_t       wait;
 228         int                     error;
 229 };
 230
 231 static void hib_init_batch(struct hib_bio_batch *hb)
 232 {
 233         atomic_set(&hb->count, 0);
 234         init_waitqueue_head(&hb->wait);
 235         hb->error = 0;
 236 }
 237
 238 static void hib_end_io(struct bio *bio)
 239 {
 240         struct hib_bio_batch *hb = bio->bi_private;
 241         struct page *page = bio->bi_io_vec[0].bv_page;
 242
 243         if (bio->bi_error) {
 244                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 245                                 imajor(bio->bi_bdev->bd_inode),
 246                                 iminor(bio->bi_bdev->bd_inode),
 247                                 (unsigned long long)bio->bi_iter.bi_sector);
 248         }
 249
 250         if (bio_data_dir(bio) == WRITE)
 251                 put_page(page);
 252         else if (clean_pages_on_read)
 253                 flush_icache_range((unsigned long)page_address(page),
 254                                    (unsigned long)page_address(page) + PAGE_SIZE);
 255
 256         if (bio->bi_error && !hb->error)
 257                 hb->error = bio->bi_error;
 258         if (atomic_dec_and_test(&hb->count))
 259                 wake_up(&hb->wait);
 260
 261         bio_put(bio);
 262 }
 263
 264 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 265                 struct hib_bio_batch *hb)
 266 {
 267         struct page *page = virt_to_page(addr);
 268         struct bio *bio;
 269         int error = 0;
 270
 271         bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
 272         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 273         bio->bi_bdev = hib_resume_bdev;
 274         bio_set_op_attrs(bio, op, op_flags);
 275
 276         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 277                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 278                         (unsigned long long)bio->bi_iter.bi_sector);
 279                 bio_put(bio);
 280                 return -EFAULT;
 281         }
 282
 283         if (hb) {
 284                 bio->bi_end_io = hib_end_io;
 285                 bio->bi_private = hb;
 286                 atomic_inc(&hb->count);
 287                 submit_bio(bio);
 288         } else {
 289                 error = submit_bio_wait(bio);
 290                 bio_put(bio);
 291         }
 292
 293         return error;
 294 }
 295
 296 static int hib_wait_io(struct hib_bio_batch *hb)
 297 {
 298         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 299         return hb->error;
 300 }
 301
 302 /*
 303  * Saving part
 304  */
 305
 306 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 307 {
 308         int error;
 309
 310         hib_submit_io(REQ_OP_READ, READ_SYNC, swsusp_resume_block,
 311                       swsusp_header, NULL);
 312         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 313             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 314                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 315                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 316                 swsusp_header->image = handle->first_sector;
 317                 swsusp_header->flags = flags;
 318                 if (flags & SF_CRC32_MODE)
 319                         swsusp_header->crc32 = handle->crc32;
 320                 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
 321                                       swsusp_resume_block, swsusp_header, NULL);
 322         } else {
 323                 printk(KERN_ERR "PM: Swap header not found!\n");
 324                 error = -ENODEV;
 325         }
 326         return error;
 327 }
 328
 329 /**
 330  *      swsusp_swap_check - check if the resume device is a swap device
 331  *      and get its index (if so)
 332  *
 333  *      This is called before saving image
 334  */
 335 static int swsusp_swap_check(void)
 336 {
 337         int res;
 338
 339         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 340                         &hib_resume_bdev);
 341         if (res < 0)
 342                 return res;
 343
 344         root_swap = res;
 345         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 346         if (res)
 347                 return res;
 348
 349         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 350         if (res < 0)
 351                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 352
 353         /*
 354          * Update the resume device to the one actually used,
 355          * so the test_resume mode can use it in case it is
 356          * invoked from hibernate() to test the snapshot.
 357          */
 358         swsusp_resume_device = hib_resume_bdev->bd_dev;
 359         return res;
 360 }
 361
 362 /**
 363  *      write_page - Write one page to given swap location.
 364  *      @buf:           Address we're writing.
 365  *      @offset:        Offset of the swap page we're writing to.
 366  *      @hb:            bio completion batch
 367  */
 368
 369 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 370 {
 371         void *src;
 372         int ret;
 373
 374         if (!offset)
 375                 return -ENOSPC;
 376
 377         if (hb) {
 378                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 379                                               __GFP_NORETRY);
 380                 if (src) {
 381                         copy_page(src, buf);
 382                 } else {
 383                         ret = hib_wait_io(hb); /* Free pages */
 384                         if (ret)
 385                                 return ret;
 386                         src = (void *)__get_free_page(__GFP_RECLAIM |
 387                                                       __GFP_NOWARN |
 388                                                       __GFP_NORETRY);
 389                         if (src) {
 390                                 copy_page(src, buf);
 391                         } else {
 392                                 WARN_ON_ONCE(1);
 393                                 hb = NULL;      /* Go synchronous */
 394                                 src = buf;
 395                         }
 396                 }
 397         } else {
 398                 src = buf;
 399         }
 400         return hib_submit_io(REQ_OP_WRITE, WRITE_SYNC, offset, src, hb);
 401 }
 402
 403 static void release_swap_writer(struct swap_map_handle *handle)
 404 {
 405         if (handle->cur)
 406                 free_page((unsigned long)handle->cur);
 407         handle->cur = NULL;
 408 }
 409
 410 static int get_swap_writer(struct swap_map_handle *handle)
 411 {
 412         int ret;
 413
 414         ret = swsusp_swap_check();
 415         if (ret) {
 416                 if (ret != -ENOSPC)
 417                         printk(KERN_ERR "PM: Cannot find swap device, try "
 418                                         "swapon -a.\n");
 419                 return ret;
 420         }
 421         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 422         if (!handle->cur) {
 423                 ret = -ENOMEM;
 424                 goto err_close;
 425         }
 426         handle->cur_swap = alloc_swapdev_block(root_swap);
 427         if (!handle->cur_swap) {
 428                 ret = -ENOSPC;
 429                 goto err_rel;
 430         }
 431         handle->k = 0;
 432         handle->reqd_free_pages = reqd_free_pages();
 433         handle->first_sector = handle->cur_swap;
 434         return 0;
 435 err_rel:
 436         release_swap_writer(handle);
 437 err_close:
 438         swsusp_close(FMODE_WRITE);
 439         return ret;
 440 }
 441
 442 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 443                 struct hib_bio_batch *hb)
 444 {
 445         int error = 0;
 446         sector_t offset;
 447
 448         if (!handle->cur)
 449                 return -EINVAL;
 450         offset = alloc_swapdev_block(root_swap);
 451         error = write_page(buf, offset, hb);
 452         if (error)
 453                 return error;
 454         handle->cur->entries[handle->k++] = offset;
 455         if (handle->k >= MAP_PAGE_ENTRIES) {
 456                 offset = alloc_swapdev_block(root_swap);
 457                 if (!offset)
 458                         return -ENOSPC;
 459                 handle->cur->next_swap = offset;
 460                 error = write_page(handle->cur, handle->cur_swap, hb);
 461                 if (error)
 462                         goto out;
 463                 clear_page(handle->cur);
 464                 handle->cur_swap = offset;
 465                 handle->k = 0;
 466
 467                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 468                         error = hib_wait_io(hb);
 469                         if (error)
 470                                 goto out;
 471                         /*
 472                          * Recalculate the number of required free pages, to
 473                          * make sure we never take more than half.
 474                          */
 475                         handle->reqd_free_pages = reqd_free_pages();
 476                 }
 477         }
 478  out:
 479         return error;
 480 }
 481
 482 static int flush_swap_writer(struct swap_map_handle *handle)
 483 {
 484         if (handle->cur && handle->cur_swap)
 485                 return write_page(handle->cur, handle->cur_swap, NULL);
 486         else
 487                 return -EINVAL;
 488 }
 489
 490 static int swap_writer_finish(struct swap_map_handle *handle,
 491                 unsigned int flags, int error)
 492 {
 493         if (!error) {
 494                 flush_swap_writer(handle);
 495                 printk(KERN_INFO "PM: S");
 496                 error = mark_swapfiles(handle, flags);
 497                 printk("|\n");
 498         }
 499
 500         if (error)
 501                 free_all_swap_pages(root_swap);
 502         release_swap_writer(handle);
 503         swsusp_close(FMODE_WRITE);
 504
 505         return error;
 506 }
 507
 508 /* We need to remember how much compressed data we need to read. */
 509 #define LZO_HEADER      sizeof(size_t)
 510
 511 /* Number of pages/bytes we'll compress at one time. */
 512 #define LZO_UNC_PAGES   32
 513 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 514
 515 /* Number of pages/bytes we need for compressed data (worst case). */
 516 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 517                                      LZO_HEADER, PAGE_SIZE)
 518 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 519
 520 /* Maximum number of threads for compression/decompression. */
 521 #define LZO_THREADS     3
 522
 523 /* Minimum/maximum number of pages for read buffering. */
 524 #define LZO_MIN_RD_PAGES        1024
 525 #define LZO_MAX_RD_PAGES        8192
 526
 527
 528 /**
 529  *      save_image - save the suspend image data
 530  */
 531
 532 static int save_image(struct swap_map_handle *handle,
 533                       struct snapshot_handle *snapshot,
 534                       unsigned int nr_to_write)
 535 {
 536         unsigned int m;
 537         int ret;
 538         int nr_pages;
 539         int err2;
 540         struct hib_bio_batch hb;
 541         ktime_t start;
 542         ktime_t stop;
 543
 544         hib_init_batch(&hb);
 545
 546         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 547                 nr_to_write);
 548         m = nr_to_write / 10;
 549         if (!m)
 550                 m = 1;
 551         nr_pages = 0;
 552         start = ktime_get();
 553         while (1) {
 554                 ret = snapshot_read_next(snapshot);
 555                 if (ret <= 0)
 556                         break;
 557                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 558                 if (ret)
 559                         break;
 560                 if (!(nr_pages % m))
 561                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 562                                nr_pages / m * 10);
 563                 nr_pages++;
 564         }
 565         err2 = hib_wait_io(&hb);
 566         stop = ktime_get();
 567         if (!ret)
 568                 ret = err2;
 569         if (!ret)
 570                 printk(KERN_INFO "PM: Image saving done.\n");
 571         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 572         return ret;
 573 }
 574
 575 /**
 576  * Structure used for CRC32.
 577  */
 578 struct crc_data {
 579         struct task_struct *thr;                  /* thread */
 580         atomic_t ready;                           /* ready to start flag */
 581         atomic_t stop;                            /* ready to stop flag */
 582         unsigned run_threads;                     /* nr current threads */
 583         wait_queue_head_t go;                     /* start crc update */
 584         wait_queue_head_t done;                   /* crc update done */
 585         u32 *crc32;                               /* points to handle's crc32 */
 586         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 587         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 588 };
 589
 590 /**
 591  * CRC32 update function that runs in its own thread.
 592  */
 593 static int crc32_threadfn(void *data)
 594 {
 595         struct crc_data *d = data;
 596         unsigned i;
 597
 598         while (1) {
 599                 wait_event(d->go, atomic_read(&d->ready) ||
 600                                   kthread_should_stop());
 601                 if (kthread_should_stop()) {
 602                         d->thr = NULL;
 603                         atomic_set(&d->stop, 1);
 604                         wake_up(&d->done);
 605                         break;
 606                 }
 607                 atomic_set(&d->ready, 0);
 608
 609                 for (i = 0; i < d->run_threads; i++)
 610                         *d->crc32 = crc32_le(*d->crc32,
 611                                              d->unc[i], *d->unc_len[i]);
 612                 atomic_set(&d->stop, 1);
 613                 wake_up(&d->done);
 614         }
 615         return 0;
 616 }
 617 /**
 618  * Structure used for LZO data compression.
 619  */
 620 struct cmp_data {
 621         struct task_struct *thr;                  /* thread */
 622         atomic_t ready;                           /* ready to start flag */
 623         atomic_t stop;                            /* ready to stop flag */
 624         int ret;                                  /* return code */
 625         wait_queue_head_t go;                     /* start compression */
 626         wait_queue_head_t done;                   /* compression done */
 627         size_t unc_len;                           /* uncompressed length */
 628         size_t cmp_len;                           /* compressed length */
 629         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 630         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 631         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 632 };
 633
 634 /**
 635  * Compression function that runs in its own thread.
 636  */
 637 static int lzo_compress_threadfn(void *data)
 638 {
 639         struct cmp_data *d = data;
 640
 641         while (1) {
 642                 wait_event(d->go, atomic_read(&d->ready) ||
 643                                   kthread_should_stop());
 644                 if (kthread_should_stop()) {
 645                         d->thr = NULL;
 646                         d->ret = -1;
 647                         atomic_set(&d->stop, 1);
 648                         wake_up(&d->done);
 649                         break;
 650                 }
 651                 atomic_set(&d->ready, 0);
 652
 653                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 654                                           d->cmp + LZO_HEADER, &d->cmp_len,
 655                                           d->wrk);
 656                 atomic_set(&d->stop, 1);
 657                 wake_up(&d->done);
 658         }
 659         return 0;
 660 }
 661
 662 /**
 663  * save_image_lzo - Save the suspend image data compressed with LZO.
 664  * @handle: Swap map handle to use for saving the image.
 665  * @snapshot: Image to read data from.
 666  * @nr_to_write: Number of pages to save.
 667  */
 668 static int save_image_lzo(struct swap_map_handle *handle,
 669                           struct snapshot_handle *snapshot,
 670                           unsigned int nr_to_write)
 671 {
 672         unsigned int m;
 673         int ret = 0;
 674         int nr_pages;
 675         int err2;
 676         struct hib_bio_batch hb;
 677         ktime_t start;
 678         ktime_t stop;
 679         size_t off;
 680         unsigned thr, run_threads, nr_threads;
 681         unsigned char *page = NULL;
 682         struct cmp_data *data = NULL;
 683         struct crc_data *crc = NULL;
 684
 685         hib_init_batch(&hb);
 686
 687         /*
 688          * We'll limit the number of threads for compression to limit memory
 689          * footprint.
 690          */
 691         nr_threads = num_online_cpus() - 1;
 692         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 693
 694         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 695         if (!page) {
 696                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 697                 ret = -ENOMEM;
 698                 goto out_clean;
 699         }
 700
 701         data = vmalloc(sizeof(*data) * nr_threads);
 702         if (!data) {
 703                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 704                 ret = -ENOMEM;
 705                 goto out_clean;
 706         }
 707         for (thr = 0; thr < nr_threads; thr++)
 708                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 709
 710         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 711         if (!crc) {
 712                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 713                 ret = -ENOMEM;
 714                 goto out_clean;
 715         }
 716         memset(crc, 0, offsetof(struct crc_data, go));
 717
 718         /*
 719          * Start the compression threads.
 720          */
 721         for (thr = 0; thr < nr_threads; thr++) {
 722                 init_waitqueue_head(&data[thr].go);
 723                 init_waitqueue_head(&data[thr].done);
 724
 725                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 726                                             &data[thr],
 727                                             "image_compress/%u", thr);
 728                 if (IS_ERR(data[thr].thr)) {
 729                         data[thr].thr = NULL;
 730                         printk(KERN_ERR
 731                                "PM: Cannot start compression threads\n");
 732                         ret = -ENOMEM;
 733                         goto out_clean;
 734                 }
 735         }
 736
 737         /*
 738          * Start the CRC32 thread.
 739          */
 740         init_waitqueue_head(&crc->go);
 741         init_waitqueue_head(&crc->done);
 742
 743         handle->crc32 = 0;
 744         crc->crc32 = &handle->crc32;
 745         for (thr = 0; thr < nr_threads; thr++) {
 746                 crc->unc[thr] = data[thr].unc;
 747                 crc->unc_len[thr] = &data[thr].unc_len;
 748         }
 749
 750         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 751         if (IS_ERR(crc->thr)) {
 752                 crc->thr = NULL;
 753                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 754                 ret = -ENOMEM;
 755                 goto out_clean;
 756         }
 757
 758         /*
 759          * Adjust the number of required free pages after all allocations have
 760          * been done. We don't want to run out of pages when writing.
 761          */
 762         handle->reqd_free_pages = reqd_free_pages();
 763
 764         printk(KERN_INFO
 765                 "PM: Using %u thread(s) for compression.\n"
 766                 "PM: Compressing and saving image data (%u pages)...\n",
 767                 nr_threads, nr_to_write);
 768         m = nr_to_write / 10;
 769         if (!m)
 770                 m = 1;
 771         nr_pages = 0;
 772         start = ktime_get();
 773         for (;;) {
 774                 for (thr = 0; thr < nr_threads; thr++) {
 775                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 776                                 ret = snapshot_read_next(snapshot);
 777                                 if (ret < 0)
 778                                         goto out_finish;
 779
 780                                 if (!ret)
 781                                         break;
 782
 783                                 memcpy(data[thr].unc + off,
 784                                        data_of(*snapshot), PAGE_SIZE);
 785
 786                                 if (!(nr_pages % m))
 787                                         printk(KERN_INFO
 788                                                "PM: Image saving progress: "
 789                                                "%3d%%\n",
 790                                                nr_pages / m * 10);
 791                                 nr_pages++;
 792                         }
 793                         if (!off)
 794                                 break;
 795
 796                         data[thr].unc_len = off;
 797
 798                         atomic_set(&data[thr].ready, 1);
 799                         wake_up(&data[thr].go);
 800                 }
 801
 802                 if (!thr)
 803                         break;
 804
 805                 crc->run_threads = thr;
 806                 atomic_set(&crc->ready, 1);
 807                 wake_up(&crc->go);
 808
 809                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 810                         wait_event(data[thr].done,
 811                                    atomic_read(&data[thr].stop));
 812                         atomic_set(&data[thr].stop, 0);
 813
 814                         ret = data[thr].ret;
 815
 816                         if (ret < 0) {
 817                                 printk(KERN_ERR "PM: LZO compression failed\n");
 818                                 goto out_finish;
 819                         }
 820
 821                         if (unlikely(!data[thr].cmp_len ||
 822                                      data[thr].cmp_len >
 823                                      lzo1x_worst_compress(data[thr].unc_len))) {
 824                                 printk(KERN_ERR
 825                                        "PM: Invalid LZO compressed length\n");
 826                                 ret = -1;
 827                                 goto out_finish;
 828                         }
 829
 830                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 831
 832                         /*
 833                          * Given we are writing one page at a time to disk, we
 834                          * copy that much from the buffer, although the last
 835                          * bit will likely be smaller than full page. This is
 836                          * OK - we saved the length of the compressed data, so
 837                          * any garbage at the end will be discarded when we
 838                          * read it.
 839                          */
 840                         for (off = 0;
 841                              off < LZO_HEADER + data[thr].cmp_len;
 842                              off += PAGE_SIZE) {
 843                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 844
 845                                 ret = swap_write_page(handle, page, &hb);
 846                                 if (ret)
 847                                         goto out_finish;
 848                         }
 849                 }
 850
 851                 wait_event(crc->done, atomic_read(&crc->stop));
 852                 atomic_set(&crc->stop, 0);
 853         }
 854
 855 out_finish:
 856         err2 = hib_wait_io(&hb);
 857         stop = ktime_get();
 858         if (!ret)
 859                 ret = err2;
 860         if (!ret)
 861                 printk(KERN_INFO "PM: Image saving done.\n");
 862         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 863 out_clean:
 864         if (crc) {
 865                 if (crc->thr)
 866                         kthread_stop(crc->thr);
 867                 kfree(crc);
 868         }
 869         if (data) {
 870                 for (thr = 0; thr < nr_threads; thr++)
 871                         if (data[thr].thr)
 872                                 kthread_stop(data[thr].thr);
 873                 vfree(data);
 874         }
 875         if (page) free_page((unsigned long)page);
 876
 877         return ret;
 878 }
 879
 880 /**
 881  *      enough_swap - Make sure we have enough swap to save the image.
 882  *
 883  *      Returns TRUE or FALSE after checking the total amount of swap
 884  *      space avaiable from the resume partition.
 885  */
 886
 887 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 888 {
 889         unsigned int free_swap = count_swap_pages(root_swap, 1);
 890         unsigned int required;
 891
 892         pr_debug("PM: Free swap pages: %u\n", free_swap);
 893
 894         required = PAGES_FOR_IO + nr_pages;
 895         return free_swap > required;
 896 }
 897
 898 /**
 899  *      swsusp_write - Write entire image and metadata.
 900  *      @flags: flags to pass to the "boot" kernel in the image header
 901  *
 902  *      It is important _NOT_ to umount filesystems at this point. We want
 903  *      them synced (in case something goes wrong) but we DO not want to mark
 904  *      filesystem clean: it is not. (And it does not matter, if we resume
 905  *      correctly, we'll mark system clean, anyway.)
 906  */
 907
 908 int swsusp_write(unsigned int flags)
 909 {
 910         struct swap_map_handle handle;
 911         struct snapshot_handle snapshot;
 912         struct swsusp_info *header;
 913         unsigned long pages;
 914         int error;
 915
 916         pages = snapshot_get_image_size();
 917         error = get_swap_writer(&handle);
 918         if (error) {
 919                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 920                 return error;
 921         }
 922         if (flags & SF_NOCOMPRESS_MODE) {
 923                 if (!enough_swap(pages, flags)) {
 924                         printk(KERN_ERR "PM: Not enough free swap\n");
 925                         error = -ENOSPC;
 926                         goto out_finish;
 927                 }
 928         }
 929         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 930         error = snapshot_read_next(&snapshot);
 931         if (error < PAGE_SIZE) {
 932                 if (error >= 0)
 933                         error = -EFAULT;
 934
 935                 goto out_finish;
 936         }
 937         header = (struct swsusp_info *)data_of(snapshot);
 938         error = swap_write_page(&handle, header, NULL);
 939         if (!error) {
 940                 error = (flags & SF_NOCOMPRESS_MODE) ?
 941                         save_image(&handle, &snapshot, pages - 1) :
 942                         save_image_lzo(&handle, &snapshot, pages - 1);
 943         }
 944 out_finish:
 945         error = swap_writer_finish(&handle, flags, error);
 946         return error;
 947 }
 948
 949 /**
 950  *      The following functions allow us to read data using a swap map
 951  *      in a file-alike way
 952  */
 953
 954 static void release_swap_reader(struct swap_map_handle *handle)
 955 {
 956         struct swap_map_page_list *tmp;
 957
 958         while (handle->maps) {
 959                 if (handle->maps->map)
 960                         free_page((unsigned long)handle->maps->map);
 961                 tmp = handle->maps;
 962                 handle->maps = handle->maps->next;
 963                 kfree(tmp);
 964         }
 965         handle->cur = NULL;
 966 }
 967
 968 static int get_swap_reader(struct swap_map_handle *handle,
 969                 unsigned int *flags_p)
 970 {
 971         int error;
 972         struct swap_map_page_list *tmp, *last;
 973         sector_t offset;
 974
 975         *flags_p = swsusp_header->flags;
 976
 977         if (!swsusp_header->image) /* how can this happen? */
 978                 return -EINVAL;
 979
 980         handle->cur = NULL;
 981         last = handle->maps = NULL;
 982         offset = swsusp_header->image;
 983         while (offset) {
 984                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 985                 if (!tmp) {
 986                         release_swap_reader(handle);
 987                         return -ENOMEM;
 988                 }
 989                 memset(tmp, 0, sizeof(*tmp));
 990                 if (!handle->maps)
 991                         handle->maps = tmp;
 992                 if (last)
 993                         last->next = tmp;
 994                 last = tmp;
 995
 996                 tmp->map = (struct swap_map_page *)
 997                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 998                 if (!tmp->map) {
 999                         release_swap_reader(handle);
1000                         return -ENOMEM;
1001                 }
1002
1003                 error = hib_submit_io(REQ_OP_READ, READ_SYNC, offset,
1004                                       tmp->map, NULL);
1005                 if (error) {
1006                         release_swap_reader(handle);
1007                         return error;
1008                 }
1009                 offset = tmp->map->next_swap;
1010         }
1011         handle->k = 0;
1012         handle->cur = handle->maps->map;
1013         return 0;
1014 }
1015
1016 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1017                 struct hib_bio_batch *hb)
1018 {
1019         sector_t offset;
1020         int error;
1021         struct swap_map_page_list *tmp;
1022
1023         if (!handle->cur)
1024                 return -EINVAL;
1025         offset = handle->cur->entries[handle->k];
1026         if (!offset)
1027                 return -EFAULT;
1028         error = hib_submit_io(REQ_OP_READ, READ_SYNC, offset, buf, hb);
1029         if (error)
1030                 return error;
1031         if (++handle->k >= MAP_PAGE_ENTRIES) {
1032                 handle->k = 0;
1033                 free_page((unsigned long)handle->maps->map);
1034                 tmp = handle->maps;
1035                 handle->maps = handle->maps->next;
1036                 kfree(tmp);
1037                 if (!handle->maps)
1038                         release_swap_reader(handle);
1039                 else
1040                         handle->cur = handle->maps->map;
1041         }
1042         return error;
1043 }
1044
1045 static int swap_reader_finish(struct swap_map_handle *handle)
1046 {
1047         release_swap_reader(handle);
1048
1049         return 0;
1050 }
1051
1052 /**
1053  *      load_image - load the image using the swap map handle
1054  *      @handle and the snapshot handle @snapshot
1055  *      (assume there are @nr_pages pages to load)
1056  */
1057
1058 static int load_image(struct swap_map_handle *handle,
1059                       struct snapshot_handle *snapshot,
1060                       unsigned int nr_to_read)
1061 {
1062         unsigned int m;
1063         int ret = 0;
1064         ktime_t start;
1065         ktime_t stop;
1066         struct hib_bio_batch hb;
1067         int err2;
1068         unsigned nr_pages;
1069
1070         hib_init_batch(&hb);
1071
1072         clean_pages_on_read = true;
1073         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1074                 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                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1093                                nr_pages / m * 10);
1094                 nr_pages++;
1095         }
1096         err2 = hib_wait_io(&hb);
1097         stop = ktime_get();
1098         if (!ret)
1099                 ret = err2;
1100         if (!ret) {
1101                 printk(KERN_INFO "PM: Image loading done.\n");
1102                 snapshot_write_finalize(snapshot);
1103                 if (!snapshot_image_loaded(snapshot))
1104                         ret = -ENODATA;
1105         }
1106         swsusp_show_speed(start, stop, nr_to_read, "Read");
1107         return ret;
1108 }
1109
1110 /**
1111  * Structure used for LZO data decompression.
1112  */
1113 struct dec_data {
1114         struct task_struct *thr;                  /* thread */
1115         atomic_t ready;                           /* ready to start flag */
1116         atomic_t stop;                            /* ready to stop flag */
1117         int ret;                                  /* return code */
1118         wait_queue_head_t go;                     /* start decompression */
1119         wait_queue_head_t done;                   /* decompression done */
1120         size_t unc_len;                           /* uncompressed length */
1121         size_t cmp_len;                           /* compressed length */
1122         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1123         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1124 };
1125
1126 /**
1127  * Deompression function that runs in its own thread.
1128  */
1129 static int lzo_decompress_threadfn(void *data)
1130 {
1131         struct dec_data *d = data;
1132
1133         while (1) {
1134                 wait_event(d->go, atomic_read(&d->ready) ||
1135                                   kthread_should_stop());
1136                 if (kthread_should_stop()) {
1137                         d->thr = NULL;
1138                         d->ret = -1;
1139                         atomic_set(&d->stop, 1);
1140                         wake_up(&d->done);
1141                         break;
1142                 }
1143                 atomic_set(&d->ready, 0);
1144
1145                 d->unc_len = LZO_UNC_SIZE;
1146                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1147                                                d->unc, &d->unc_len);
1148                 if (clean_pages_on_decompress)
1149                         flush_icache_range((unsigned long)d->unc,
1150                                            (unsigned long)d->unc + d->unc_len);
1151
1152                 atomic_set(&d->stop, 1);
1153                 wake_up(&d->done);
1154         }
1155         return 0;
1156 }
1157
1158 /**
1159  * load_image_lzo - Load compressed image data and decompress them with LZO.
1160  * @handle: Swap map handle to use for loading data.
1161  * @snapshot: Image to copy uncompressed data into.
1162  * @nr_to_read: Number of pages to load.
1163  */
1164 static int load_image_lzo(struct swap_map_handle *handle,
1165                           struct snapshot_handle *snapshot,
1166                           unsigned int nr_to_read)
1167 {
1168         unsigned int m;
1169         int ret = 0;
1170         int eof = 0;
1171         struct hib_bio_batch hb;
1172         ktime_t start;
1173         ktime_t stop;
1174         unsigned nr_pages;
1175         size_t off;
1176         unsigned i, thr, run_threads, nr_threads;
1177         unsigned ring = 0, pg = 0, ring_size = 0,
1178                  have = 0, want, need, asked = 0;
1179         unsigned long read_pages = 0;
1180         unsigned char **page = NULL;
1181         struct dec_data *data = NULL;
1182         struct crc_data *crc = NULL;
1183
1184         hib_init_batch(&hb);
1185
1186         /*
1187          * We'll limit the number of threads for decompression to limit memory
1188          * footprint.
1189          */
1190         nr_threads = num_online_cpus() - 1;
1191         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1192
1193         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1194         if (!page) {
1195                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1196                 ret = -ENOMEM;
1197                 goto out_clean;
1198         }
1199
1200         data = vmalloc(sizeof(*data) * nr_threads);
1201         if (!data) {
1202                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1203                 ret = -ENOMEM;
1204                 goto out_clean;
1205         }
1206         for (thr = 0; thr < nr_threads; thr++)
1207                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1208
1209         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1210         if (!crc) {
1211                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1212                 ret = -ENOMEM;
1213                 goto out_clean;
1214         }
1215         memset(crc, 0, offsetof(struct crc_data, go));
1216
1217         clean_pages_on_decompress = true;
1218
1219         /*
1220          * Start the decompression threads.
1221          */
1222         for (thr = 0; thr < nr_threads; thr++) {
1223                 init_waitqueue_head(&data[thr].go);
1224                 init_waitqueue_head(&data[thr].done);
1225
1226                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1227                                             &data[thr],
1228                                             "image_decompress/%u", thr);
1229                 if (IS_ERR(data[thr].thr)) {
1230                         data[thr].thr = NULL;
1231                         printk(KERN_ERR
1232                                "PM: Cannot start decompression threads\n");
1233                         ret = -ENOMEM;
1234                         goto out_clean;
1235                 }
1236         }
1237
1238         /*
1239          * Start the CRC32 thread.
1240          */
1241         init_waitqueue_head(&crc->go);
1242         init_waitqueue_head(&crc->done);
1243
1244         handle->crc32 = 0;
1245         crc->crc32 = &handle->crc32;
1246         for (thr = 0; thr < nr_threads; thr++) {
1247                 crc->unc[thr] = data[thr].unc;
1248                 crc->unc_len[thr] = &data[thr].unc_len;
1249         }
1250
1251         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1252         if (IS_ERR(crc->thr)) {
1253                 crc->thr = NULL;
1254                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1255                 ret = -ENOMEM;
1256                 goto out_clean;
1257         }
1258
1259         /*
1260          * Set the number of pages for read buffering.
1261          * This is complete guesswork, because we'll only know the real
1262          * picture once prepare_image() is called, which is much later on
1263          * during the image load phase. We'll assume the worst case and
1264          * say that none of the image pages are from high memory.
1265          */
1266         if (low_free_pages() > snapshot_get_image_size())
1267                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1268         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1269
1270         for (i = 0; i < read_pages; i++) {
1271                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1272                                                   __GFP_RECLAIM | __GFP_HIGH :
1273                                                   __GFP_RECLAIM | __GFP_NOWARN |
1274                                                   __GFP_NORETRY);
1275
1276                 if (!page[i]) {
1277                         if (i < LZO_CMP_PAGES) {
1278                                 ring_size = i;
1279                                 printk(KERN_ERR
1280                                        "PM: Failed to allocate LZO pages\n");
1281                                 ret = -ENOMEM;
1282                                 goto out_clean;
1283                         } else {
1284                                 break;
1285                         }
1286                 }
1287         }
1288         want = ring_size = i;
1289
1290         printk(KERN_INFO
1291                 "PM: Using %u thread(s) for decompression.\n"
1292                 "PM: Loading and decompressing image data (%u pages)...\n",
1293                 nr_threads, nr_to_read);
1294         m = nr_to_read / 10;
1295         if (!m)
1296                 m = 1;
1297         nr_pages = 0;
1298         start = ktime_get();
1299
1300         ret = snapshot_write_next(snapshot);
1301         if (ret <= 0)
1302                 goto out_finish;
1303
1304         for(;;) {
1305                 for (i = 0; !eof && i < want; i++) {
1306                         ret = swap_read_page(handle, page[ring], &hb);
1307                         if (ret) {
1308                                 /*
1309                                  * On real read error, finish. On end of data,
1310                                  * set EOF flag and just exit the read loop.
1311                                  */
1312                                 if (handle->cur &&
1313                                     handle->cur->entries[handle->k]) {
1314                                         goto out_finish;
1315                                 } else {
1316                                         eof = 1;
1317                                         break;
1318                                 }
1319                         }
1320                         if (++ring >= ring_size)
1321                                 ring = 0;
1322                 }
1323                 asked += i;
1324                 want -= i;
1325
1326                 /*
1327                  * We are out of data, wait for some more.
1328                  */
1329                 if (!have) {
1330                         if (!asked)
1331                                 break;
1332
1333                         ret = hib_wait_io(&hb);
1334                         if (ret)
1335                                 goto out_finish;
1336                         have += asked;
1337                         asked = 0;
1338                         if (eof)
1339                                 eof = 2;
1340                 }
1341
1342                 if (crc->run_threads) {
1343                         wait_event(crc->done, atomic_read(&crc->stop));
1344                         atomic_set(&crc->stop, 0);
1345                         crc->run_threads = 0;
1346                 }
1347
1348                 for (thr = 0; have && thr < nr_threads; thr++) {
1349                         data[thr].cmp_len = *(size_t *)page[pg];
1350                         if (unlikely(!data[thr].cmp_len ||
1351                                      data[thr].cmp_len >
1352                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1353                                 printk(KERN_ERR
1354                                        "PM: Invalid LZO compressed length\n");
1355                                 ret = -1;
1356                                 goto out_finish;
1357                         }
1358
1359                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1360                                             PAGE_SIZE);
1361                         if (need > have) {
1362                                 if (eof > 1) {
1363                                         ret = -1;
1364                                         goto out_finish;
1365                                 }
1366                                 break;
1367                         }
1368
1369                         for (off = 0;
1370                              off < LZO_HEADER + data[thr].cmp_len;
1371                              off += PAGE_SIZE) {
1372                                 memcpy(data[thr].cmp + off,
1373                                        page[pg], PAGE_SIZE);
1374                                 have--;
1375                                 want++;
1376                                 if (++pg >= ring_size)
1377                                         pg = 0;
1378                         }
1379
1380                         atomic_set(&data[thr].ready, 1);
1381                         wake_up(&data[thr].go);
1382                 }
1383
1384                 /*
1385                  * Wait for more data while we are decompressing.
1386                  */
1387                 if (have < LZO_CMP_PAGES && asked) {
1388                         ret = hib_wait_io(&hb);
1389                         if (ret)
1390                                 goto out_finish;
1391                         have += asked;
1392                         asked = 0;
1393                         if (eof)
1394                                 eof = 2;
1395                 }
1396
1397                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1398                         wait_event(data[thr].done,
1399                                    atomic_read(&data[thr].stop));
1400                         atomic_set(&data[thr].stop, 0);
1401
1402                         ret = data[thr].ret;
1403
1404                         if (ret < 0) {
1405                                 printk(KERN_ERR
1406                                        "PM: LZO decompression failed\n");
1407                                 goto out_finish;
1408                         }
1409
1410                         if (unlikely(!data[thr].unc_len ||
1411                                      data[thr].unc_len > LZO_UNC_SIZE ||
1412                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1413                                 printk(KERN_ERR
1414                                        "PM: Invalid LZO uncompressed length\n");
1415                                 ret = -1;
1416                                 goto out_finish;
1417                         }
1418
1419                         for (off = 0;
1420                              off < data[thr].unc_len; off += PAGE_SIZE) {
1421                                 memcpy(data_of(*snapshot),
1422                                        data[thr].unc + off, PAGE_SIZE);
1423
1424                                 if (!(nr_pages % m))
1425                                         printk(KERN_INFO
1426                                                "PM: Image loading progress: "
1427                                                "%3d%%\n",
1428                                                nr_pages / m * 10);
1429                                 nr_pages++;
1430
1431                                 ret = snapshot_write_next(snapshot);
1432                                 if (ret <= 0) {
1433                                         crc->run_threads = thr + 1;
1434                                         atomic_set(&crc->ready, 1);
1435                                         wake_up(&crc->go);
1436                                         goto out_finish;
1437                                 }
1438                         }
1439                 }
1440
1441                 crc->run_threads = thr;
1442                 atomic_set(&crc->ready, 1);
1443                 wake_up(&crc->go);
1444         }
1445
1446 out_finish:
1447         if (crc->run_threads) {
1448                 wait_event(crc->done, atomic_read(&crc->stop));
1449                 atomic_set(&crc->stop, 0);
1450         }
1451         stop = ktime_get();
1452         if (!ret) {
1453                 printk(KERN_INFO "PM: Image loading done.\n");
1454                 snapshot_write_finalize(snapshot);
1455                 if (!snapshot_image_loaded(snapshot))
1456                         ret = -ENODATA;
1457                 if (!ret) {
1458                         if (swsusp_header->flags & SF_CRC32_MODE) {
1459                                 if(handle->crc32 != swsusp_header->crc32) {
1460                                         printk(KERN_ERR
1461                                                "PM: Invalid image CRC32!\n");
1462                                         ret = -ENODATA;
1463                                 }
1464                         }
1465                 }
1466         }
1467         swsusp_show_speed(start, stop, nr_to_read, "Read");
1468 out_clean:
1469         for (i = 0; i < ring_size; i++)
1470                 free_page((unsigned long)page[i]);
1471         if (crc) {
1472                 if (crc->thr)
1473                         kthread_stop(crc->thr);
1474                 kfree(crc);
1475         }
1476         if (data) {
1477                 for (thr = 0; thr < nr_threads; thr++)
1478                         if (data[thr].thr)
1479                                 kthread_stop(data[thr].thr);
1480                 vfree(data);
1481         }
1482         vfree(page);
1483
1484         return ret;
1485 }
1486
1487 /**
1488  *      swsusp_read - read the hibernation image.
1489  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1490  *                be written into this memory location
1491  */
1492
1493 int swsusp_read(unsigned int *flags_p)
1494 {
1495         int error;
1496         struct swap_map_handle handle;
1497         struct snapshot_handle snapshot;
1498         struct swsusp_info *header;
1499
1500         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1501         error = snapshot_write_next(&snapshot);
1502         if (error < PAGE_SIZE)
1503                 return error < 0 ? error : -EFAULT;
1504         header = (struct swsusp_info *)data_of(snapshot);
1505         error = get_swap_reader(&handle, flags_p);
1506         if (error)
1507                 goto end;
1508         if (!error)
1509                 error = swap_read_page(&handle, header, NULL);
1510         if (!error) {
1511                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1512                         load_image(&handle, &snapshot, header->pages - 1) :
1513                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1514         }
1515         swap_reader_finish(&handle);
1516 end:
1517         if (!error)
1518                 pr_debug("PM: Image successfully loaded\n");
1519         else
1520                 pr_debug("PM: Error %d resuming\n", error);
1521         return error;
1522 }
1523
1524 /**
1525  *      swsusp_check - Check for swsusp signature in the resume device
1526  */
1527
1528 int swsusp_check(void)
1529 {
1530         int error;
1531
1532         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1533                                             FMODE_READ, NULL);
1534         if (!IS_ERR(hib_resume_bdev)) {
1535                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1536                 clear_page(swsusp_header);
1537                 error = hib_submit_io(REQ_OP_READ, READ_SYNC,
1538                                         swsusp_resume_block,
1539                                         swsusp_header, NULL);
1540                 if (error)
1541                         goto put;
1542
1543                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1544                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1545                         /* Reset swap signature now */
1546                         error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
1547                                                 swsusp_resume_block,
1548                                                 swsusp_header, NULL);
1549                 } else {
1550                         error = -EINVAL;
1551                 }
1552
1553 put:
1554                 if (error)
1555                         blkdev_put(hib_resume_bdev, FMODE_READ);
1556                 else
1557                         pr_debug("PM: Image signature found, resuming\n");
1558         } else {
1559                 error = PTR_ERR(hib_resume_bdev);
1560         }
1561
1562         if (error)
1563                 pr_debug("PM: Image not found (code %d)\n", error);
1564
1565         return error;
1566 }
1567
1568 /**
1569  *      swsusp_close - close swap device.
1570  */
1571
1572 void swsusp_close(fmode_t mode)
1573 {
1574         if (IS_ERR(hib_resume_bdev)) {
1575                 pr_debug("PM: Image device not initialised\n");
1576                 return;
1577         }
1578
1579         blkdev_put(hib_resume_bdev, mode);
1580 }
1581
1582 /**
1583  *      swsusp_unmark - Unmark swsusp signature in the resume device
1584  */
1585
1586 #ifdef CONFIG_SUSPEND
1587 int swsusp_unmark(void)
1588 {
1589         int error;
1590
1591         hib_submit_io(REQ_OP_READ, READ_SYNC, swsusp_resume_block,
1592                       swsusp_header, NULL);
1593         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1594                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1595                 error = hib_submit_io(REQ_OP_WRITE, WRITE_SYNC,
1596                                         swsusp_resume_block,
1597                                         swsusp_header, NULL);
1598         } else {
1599                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1600                 error = -ENODEV;
1601         }
1602
1603         /*
1604          * We just returned from suspend, we don't need the image any more.
1605          */
1606         free_all_swap_pages(root_swap);
1607
1608         return error;
1609 }
1610 #endif
1611
1612 static int swsusp_header_init(void)
1613 {
1614         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1615         if (!swsusp_header)
1616                 panic("Could not allocate memory for swsusp_header\n");
1617         return 0;
1618 }
1619
1620 core_initcall(swsusp_header_init);