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