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 = rb_entry(node, struct swsusp_extent, node);
 205                 rb_erase(node, &swsusp_extents);
 206                 for (offset = ext->start; offset <= ext->end; offset++)
 207                         swap_free(swp_entry(swap, offset));
 208
 209                 kfree(ext);
 210         }
 211 }
 212
 213 int swsusp_swap_in_use(void)
 214 {
 215         return (swsusp_extents.rb_node != NULL);
 216 }
 217
 218 /*
 219  * General things
 220  */
 221
 222 static unsigned short root_swap = 0xffff;
 223 static struct block_device *hib_resume_bdev;
 224
 225 struct hib_bio_batch {
 226         atomic_t                count;
 227         wait_queue_head_t       wait;
 228         blk_status_t            error;
 229 };
 230
 231 static void hib_init_batch(struct hib_bio_batch *hb)
 232 {
 233         atomic_set(&hb->count, 0);
 234         init_waitqueue_head(&hb->wait);
 235         hb->error = BLK_STS_OK;
 236 }
 237
 238 static void hib_end_io(struct bio *bio)
 239 {
 240         struct hib_bio_batch *hb = bio->bi_private;
 241         struct page *page = bio->bi_io_vec[0].bv_page;
 242
 243         if (bio->bi_status) {
 244                 printk(KERN_ALERT "Read-error on swap-device (%u:%u:%Lu)\n",
 245                                 MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 246                                 (unsigned long long)bio->bi_iter.bi_sector);
 247         }
 248
 249         if (bio_data_dir(bio) == WRITE)
 250                 put_page(page);
 251         else if (clean_pages_on_read)
 252                 flush_icache_range((unsigned long)page_address(page),
 253                                    (unsigned long)page_address(page) + PAGE_SIZE);
 254
 255         if (bio->bi_status && !hb->error)
 256                 hb->error = bio->bi_status;
 257         if (atomic_dec_and_test(&hb->count))
 258                 wake_up(&hb->wait);
 259
 260         bio_put(bio);
 261 }
 262
 263 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 264                 struct hib_bio_batch *hb)
 265 {
 266         struct page *page = virt_to_page(addr);
 267         struct bio *bio;
 268         int error = 0;
 269
 270         bio = bio_alloc(__GFP_RECLAIM | __GFP_HIGH, 1);
 271         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 272         bio_set_dev(bio, hib_resume_bdev);
 273         bio_set_op_attrs(bio, op, op_flags);
 274
 275         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 276                 printk(KERN_ERR "PM: Adding page to bio failed at %llu\n",
 277                         (unsigned long long)bio->bi_iter.bi_sector);
 278                 bio_put(bio);
 279                 return -EFAULT;
 280         }
 281
 282         if (hb) {
 283                 bio->bi_end_io = hib_end_io;
 284                 bio->bi_private = hb;
 285                 atomic_inc(&hb->count);
 286                 submit_bio(bio);
 287         } else {
 288                 error = submit_bio_wait(bio);
 289                 bio_put(bio);
 290         }
 291
 292         return error;
 293 }
 294
 295 static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
 296 {
 297         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 298         return blk_status_to_errno(hb->error);
 299 }
 300
 301 /*
 302  * Saving part
 303  */
 304
 305 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 306 {
 307         int error;
 308
 309         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
 310                       swsusp_header, NULL);
 311         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 312             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 313                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 314                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 315                 swsusp_header->image = handle->first_sector;
 316                 swsusp_header->flags = flags;
 317                 if (flags & SF_CRC32_MODE)
 318                         swsusp_header->crc32 = handle->crc32;
 319                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
 320                                       swsusp_resume_block, swsusp_header, NULL);
 321         } else {
 322                 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         /*
 353          * Update the resume device to the one actually used,
 354          * so the test_resume mode can use it in case it is
 355          * invoked from hibernate() to test the snapshot.
 356          */
 357         swsusp_resume_device = hib_resume_bdev->bd_dev;
 358         return res;
 359 }
 360
 361 /**
 362  *      write_page - Write one page to given swap location.
 363  *      @buf:           Address we're writing.
 364  *      @offset:        Offset of the swap page we're writing to.
 365  *      @hb:            bio completion batch
 366  */
 367
 368 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 369 {
 370         void *src;
 371         int ret;
 372
 373         if (!offset)
 374                 return -ENOSPC;
 375
 376         if (hb) {
 377                 src = (void *)__get_free_page(__GFP_RECLAIM | __GFP_NOWARN |
 378                                               __GFP_NORETRY);
 379                 if (src) {
 380                         copy_page(src, buf);
 381                 } else {
 382                         ret = hib_wait_io(hb); /* Free pages */
 383                         if (ret)
 384                                 return ret;
 385                         src = (void *)__get_free_page(__GFP_RECLAIM |
 386                                                       __GFP_NOWARN |
 387                                                       __GFP_NORETRY);
 388                         if (src) {
 389                                 copy_page(src, buf);
 390                         } else {
 391                                 WARN_ON_ONCE(1);
 392                                 hb = NULL;      /* Go synchronous */
 393                                 src = buf;
 394                         }
 395                 }
 396         } else {
 397                 src = buf;
 398         }
 399         return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
 400 }
 401
 402 static void release_swap_writer(struct swap_map_handle *handle)
 403 {
 404         if (handle->cur)
 405                 free_page((unsigned long)handle->cur);
 406         handle->cur = NULL;
 407 }
 408
 409 static int get_swap_writer(struct swap_map_handle *handle)
 410 {
 411         int ret;
 412
 413         ret = swsusp_swap_check();
 414         if (ret) {
 415                 if (ret != -ENOSPC)
 416                         printk(KERN_ERR "PM: Cannot find swap device, try "
 417                                         "swapon -a.\n");
 418                 return ret;
 419         }
 420         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 421         if (!handle->cur) {
 422                 ret = -ENOMEM;
 423                 goto err_close;
 424         }
 425         handle->cur_swap = alloc_swapdev_block(root_swap);
 426         if (!handle->cur_swap) {
 427                 ret = -ENOSPC;
 428                 goto err_rel;
 429         }
 430         handle->k = 0;
 431         handle->reqd_free_pages = reqd_free_pages();
 432         handle->first_sector = handle->cur_swap;
 433         return 0;
 434 err_rel:
 435         release_swap_writer(handle);
 436 err_close:
 437         swsusp_close(FMODE_WRITE);
 438         return ret;
 439 }
 440
 441 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 442                 struct hib_bio_batch *hb)
 443 {
 444         int error = 0;
 445         sector_t offset;
 446
 447         if (!handle->cur)
 448                 return -EINVAL;
 449         offset = alloc_swapdev_block(root_swap);
 450         error = write_page(buf, offset, hb);
 451         if (error)
 452                 return error;
 453         handle->cur->entries[handle->k++] = offset;
 454         if (handle->k >= MAP_PAGE_ENTRIES) {
 455                 offset = alloc_swapdev_block(root_swap);
 456                 if (!offset)
 457                         return -ENOSPC;
 458                 handle->cur->next_swap = offset;
 459                 error = write_page(handle->cur, handle->cur_swap, hb);
 460                 if (error)
 461                         goto out;
 462                 clear_page(handle->cur);
 463                 handle->cur_swap = offset;
 464                 handle->k = 0;
 465
 466                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 467                         error = hib_wait_io(hb);
 468                         if (error)
 469                                 goto out;
 470                         /*
 471                          * Recalculate the number of required free pages, to
 472                          * make sure we never take more than half.
 473                          */
 474                         handle->reqd_free_pages = reqd_free_pages();
 475                 }
 476         }
 477  out:
 478         return error;
 479 }
 480
 481 static int flush_swap_writer(struct swap_map_handle *handle)
 482 {
 483         if (handle->cur && handle->cur_swap)
 484                 return write_page(handle->cur, handle->cur_swap, NULL);
 485         else
 486                 return -EINVAL;
 487 }
 488
 489 static int swap_writer_finish(struct swap_map_handle *handle,
 490                 unsigned int flags, int error)
 491 {
 492         if (!error) {
 493                 flush_swap_writer(handle);
 494                 printk(KERN_INFO "PM: S");
 495                 error = mark_swapfiles(handle, flags);
 496                 printk("|\n");
 497         }
 498
 499         if (error)
 500                 free_all_swap_pages(root_swap);
 501         release_swap_writer(handle);
 502         swsusp_close(FMODE_WRITE);
 503
 504         return error;
 505 }
 506
 507 /* We need to remember how much compressed data we need to read. */
 508 #define LZO_HEADER      sizeof(size_t)
 509
 510 /* Number of pages/bytes we'll compress at one time. */
 511 #define LZO_UNC_PAGES   32
 512 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 513
 514 /* Number of pages/bytes we need for compressed data (worst case). */
 515 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 516                                      LZO_HEADER, PAGE_SIZE)
 517 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 518
 519 /* Maximum number of threads for compression/decompression. */
 520 #define LZO_THREADS     3
 521
 522 /* Minimum/maximum number of pages for read buffering. */
 523 #define LZO_MIN_RD_PAGES        1024
 524 #define LZO_MAX_RD_PAGES        8192
 525
 526
 527 /**
 528  *      save_image - save the suspend image data
 529  */
 530
 531 static int save_image(struct swap_map_handle *handle,
 532                       struct snapshot_handle *snapshot,
 533                       unsigned int nr_to_write)
 534 {
 535         unsigned int m;
 536         int ret;
 537         int nr_pages;
 538         int err2;
 539         struct hib_bio_batch hb;
 540         ktime_t start;
 541         ktime_t stop;
 542
 543         hib_init_batch(&hb);
 544
 545         printk(KERN_INFO "PM: Saving image data pages (%u pages)...\n",
 546                 nr_to_write);
 547         m = nr_to_write / 10;
 548         if (!m)
 549                 m = 1;
 550         nr_pages = 0;
 551         start = ktime_get();
 552         while (1) {
 553                 ret = snapshot_read_next(snapshot);
 554                 if (ret <= 0)
 555                         break;
 556                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 557                 if (ret)
 558                         break;
 559                 if (!(nr_pages % m))
 560                         printk(KERN_INFO "PM: Image saving progress: %3d%%\n",
 561                                nr_pages / m * 10);
 562                 nr_pages++;
 563         }
 564         err2 = hib_wait_io(&hb);
 565         stop = ktime_get();
 566         if (!ret)
 567                 ret = err2;
 568         if (!ret)
 569                 printk(KERN_INFO "PM: Image saving done.\n");
 570         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 571         return ret;
 572 }
 573
 574 /**
 575  * Structure used for CRC32.
 576  */
 577 struct crc_data {
 578         struct task_struct *thr;                  /* thread */
 579         atomic_t ready;                           /* ready to start flag */
 580         atomic_t stop;                            /* ready to stop flag */
 581         unsigned run_threads;                     /* nr current threads */
 582         wait_queue_head_t go;                     /* start crc update */
 583         wait_queue_head_t done;                   /* crc update done */
 584         u32 *crc32;                               /* points to handle's crc32 */
 585         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 586         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 587 };
 588
 589 /**
 590  * CRC32 update function that runs in its own thread.
 591  */
 592 static int crc32_threadfn(void *data)
 593 {
 594         struct crc_data *d = data;
 595         unsigned i;
 596
 597         while (1) {
 598                 wait_event(d->go, atomic_read(&d->ready) ||
 599                                   kthread_should_stop());
 600                 if (kthread_should_stop()) {
 601                         d->thr = NULL;
 602                         atomic_set(&d->stop, 1);
 603                         wake_up(&d->done);
 604                         break;
 605                 }
 606                 atomic_set(&d->ready, 0);
 607
 608                 for (i = 0; i < d->run_threads; i++)
 609                         *d->crc32 = crc32_le(*d->crc32,
 610                                              d->unc[i], *d->unc_len[i]);
 611                 atomic_set(&d->stop, 1);
 612                 wake_up(&d->done);
 613         }
 614         return 0;
 615 }
 616 /**
 617  * Structure used for LZO data compression.
 618  */
 619 struct cmp_data {
 620         struct task_struct *thr;                  /* thread */
 621         atomic_t ready;                           /* ready to start flag */
 622         atomic_t stop;                            /* ready to stop flag */
 623         int ret;                                  /* return code */
 624         wait_queue_head_t go;                     /* start compression */
 625         wait_queue_head_t done;                   /* compression done */
 626         size_t unc_len;                           /* uncompressed length */
 627         size_t cmp_len;                           /* compressed length */
 628         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 629         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 630         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 631 };
 632
 633 /**
 634  * Compression function that runs in its own thread.
 635  */
 636 static int lzo_compress_threadfn(void *data)
 637 {
 638         struct cmp_data *d = data;
 639
 640         while (1) {
 641                 wait_event(d->go, atomic_read(&d->ready) ||
 642                                   kthread_should_stop());
 643                 if (kthread_should_stop()) {
 644                         d->thr = NULL;
 645                         d->ret = -1;
 646                         atomic_set(&d->stop, 1);
 647                         wake_up(&d->done);
 648                         break;
 649                 }
 650                 atomic_set(&d->ready, 0);
 651
 652                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 653                                           d->cmp + LZO_HEADER, &d->cmp_len,
 654                                           d->wrk);
 655                 atomic_set(&d->stop, 1);
 656                 wake_up(&d->done);
 657         }
 658         return 0;
 659 }
 660
 661 /**
 662  * save_image_lzo - Save the suspend image data compressed with LZO.
 663  * @handle: Swap map handle to use for saving the image.
 664  * @snapshot: Image to read data from.
 665  * @nr_to_write: Number of pages to save.
 666  */
 667 static int save_image_lzo(struct swap_map_handle *handle,
 668                           struct snapshot_handle *snapshot,
 669                           unsigned int nr_to_write)
 670 {
 671         unsigned int m;
 672         int ret = 0;
 673         int nr_pages;
 674         int err2;
 675         struct hib_bio_batch hb;
 676         ktime_t start;
 677         ktime_t stop;
 678         size_t off;
 679         unsigned thr, run_threads, nr_threads;
 680         unsigned char *page = NULL;
 681         struct cmp_data *data = NULL;
 682         struct crc_data *crc = NULL;
 683
 684         hib_init_batch(&hb);
 685
 686         /*
 687          * We'll limit the number of threads for compression to limit memory
 688          * footprint.
 689          */
 690         nr_threads = num_online_cpus() - 1;
 691         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 692
 693         page = (void *)__get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 694         if (!page) {
 695                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
 696                 ret = -ENOMEM;
 697                 goto out_clean;
 698         }
 699
 700         data = vmalloc(sizeof(*data) * nr_threads);
 701         if (!data) {
 702                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
 703                 ret = -ENOMEM;
 704                 goto out_clean;
 705         }
 706         for (thr = 0; thr < nr_threads; thr++)
 707                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 708
 709         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 710         if (!crc) {
 711                 printk(KERN_ERR "PM: Failed to allocate crc\n");
 712                 ret = -ENOMEM;
 713                 goto out_clean;
 714         }
 715         memset(crc, 0, offsetof(struct crc_data, go));
 716
 717         /*
 718          * Start the compression threads.
 719          */
 720         for (thr = 0; thr < nr_threads; thr++) {
 721                 init_waitqueue_head(&data[thr].go);
 722                 init_waitqueue_head(&data[thr].done);
 723
 724                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 725                                             &data[thr],
 726                                             "image_compress/%u", thr);
 727                 if (IS_ERR(data[thr].thr)) {
 728                         data[thr].thr = NULL;
 729                         printk(KERN_ERR
 730                                "PM: Cannot start compression threads\n");
 731                         ret = -ENOMEM;
 732                         goto out_clean;
 733                 }
 734         }
 735
 736         /*
 737          * Start the CRC32 thread.
 738          */
 739         init_waitqueue_head(&crc->go);
 740         init_waitqueue_head(&crc->done);
 741
 742         handle->crc32 = 0;
 743         crc->crc32 = &handle->crc32;
 744         for (thr = 0; thr < nr_threads; thr++) {
 745                 crc->unc[thr] = data[thr].unc;
 746                 crc->unc_len[thr] = &data[thr].unc_len;
 747         }
 748
 749         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 750         if (IS_ERR(crc->thr)) {
 751                 crc->thr = NULL;
 752                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
 753                 ret = -ENOMEM;
 754                 goto out_clean;
 755         }
 756
 757         /*
 758          * Adjust the number of required free pages after all allocations have
 759          * been done. We don't want to run out of pages when writing.
 760          */
 761         handle->reqd_free_pages = reqd_free_pages();
 762
 763         printk(KERN_INFO
 764                 "PM: Using %u thread(s) for compression.\n"
 765                 "PM: Compressing and saving image data (%u pages)...\n",
 766                 nr_threads, nr_to_write);
 767         m = nr_to_write / 10;
 768         if (!m)
 769                 m = 1;
 770         nr_pages = 0;
 771         start = ktime_get();
 772         for (;;) {
 773                 for (thr = 0; thr < nr_threads; thr++) {
 774                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 775                                 ret = snapshot_read_next(snapshot);
 776                                 if (ret < 0)
 777                                         goto out_finish;
 778
 779                                 if (!ret)
 780                                         break;
 781
 782                                 memcpy(data[thr].unc + off,
 783                                        data_of(*snapshot), PAGE_SIZE);
 784
 785                                 if (!(nr_pages % m))
 786                                         printk(KERN_INFO
 787                                                "PM: Image saving progress: "
 788                                                "%3d%%\n",
 789                                                nr_pages / m * 10);
 790                                 nr_pages++;
 791                         }
 792                         if (!off)
 793                                 break;
 794
 795                         data[thr].unc_len = off;
 796
 797                         atomic_set(&data[thr].ready, 1);
 798                         wake_up(&data[thr].go);
 799                 }
 800
 801                 if (!thr)
 802                         break;
 803
 804                 crc->run_threads = thr;
 805                 atomic_set(&crc->ready, 1);
 806                 wake_up(&crc->go);
 807
 808                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 809                         wait_event(data[thr].done,
 810                                    atomic_read(&data[thr].stop));
 811                         atomic_set(&data[thr].stop, 0);
 812
 813                         ret = data[thr].ret;
 814
 815                         if (ret < 0) {
 816                                 printk(KERN_ERR "PM: LZO compression failed\n");
 817                                 goto out_finish;
 818                         }
 819
 820                         if (unlikely(!data[thr].cmp_len ||
 821                                      data[thr].cmp_len >
 822                                      lzo1x_worst_compress(data[thr].unc_len))) {
 823                                 printk(KERN_ERR
 824                                        "PM: Invalid LZO compressed length\n");
 825                                 ret = -1;
 826                                 goto out_finish;
 827                         }
 828
 829                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 830
 831                         /*
 832                          * Given we are writing one page at a time to disk, we
 833                          * copy that much from the buffer, although the last
 834                          * bit will likely be smaller than full page. This is
 835                          * OK - we saved the length of the compressed data, so
 836                          * any garbage at the end will be discarded when we
 837                          * read it.
 838                          */
 839                         for (off = 0;
 840                              off < LZO_HEADER + data[thr].cmp_len;
 841                              off += PAGE_SIZE) {
 842                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 843
 844                                 ret = swap_write_page(handle, page, &hb);
 845                                 if (ret)
 846                                         goto out_finish;
 847                         }
 848                 }
 849
 850                 wait_event(crc->done, atomic_read(&crc->stop));
 851                 atomic_set(&crc->stop, 0);
 852         }
 853
 854 out_finish:
 855         err2 = hib_wait_io(&hb);
 856         stop = ktime_get();
 857         if (!ret)
 858                 ret = err2;
 859         if (!ret)
 860                 printk(KERN_INFO "PM: Image saving done.\n");
 861         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 862 out_clean:
 863         if (crc) {
 864                 if (crc->thr)
 865                         kthread_stop(crc->thr);
 866                 kfree(crc);
 867         }
 868         if (data) {
 869                 for (thr = 0; thr < nr_threads; thr++)
 870                         if (data[thr].thr)
 871                                 kthread_stop(data[thr].thr);
 872                 vfree(data);
 873         }
 874         if (page) free_page((unsigned long)page);
 875
 876         return ret;
 877 }
 878
 879 /**
 880  *      enough_swap - Make sure we have enough swap to save the image.
 881  *
 882  *      Returns TRUE or FALSE after checking the total amount of swap
 883  *      space avaiable from the resume partition.
 884  */
 885
 886 static int enough_swap(unsigned int nr_pages, unsigned int flags)
 887 {
 888         unsigned int free_swap = count_swap_pages(root_swap, 1);
 889         unsigned int required;
 890
 891         pr_debug("PM: Free swap pages: %u\n", free_swap);
 892
 893         required = PAGES_FOR_IO + nr_pages;
 894         return free_swap > required;
 895 }
 896
 897 /**
 898  *      swsusp_write - Write entire image and metadata.
 899  *      @flags: flags to pass to the "boot" kernel in the image header
 900  *
 901  *      It is important _NOT_ to umount filesystems at this point. We want
 902  *      them synced (in case something goes wrong) but we DO not want to mark
 903  *      filesystem clean: it is not. (And it does not matter, if we resume
 904  *      correctly, we'll mark system clean, anyway.)
 905  */
 906
 907 int swsusp_write(unsigned int flags)
 908 {
 909         struct swap_map_handle handle;
 910         struct snapshot_handle snapshot;
 911         struct swsusp_info *header;
 912         unsigned long pages;
 913         int error;
 914
 915         pages = snapshot_get_image_size();
 916         error = get_swap_writer(&handle);
 917         if (error) {
 918                 printk(KERN_ERR "PM: Cannot get swap writer\n");
 919                 return error;
 920         }
 921         if (flags & SF_NOCOMPRESS_MODE) {
 922                 if (!enough_swap(pages, flags)) {
 923                         printk(KERN_ERR "PM: Not enough free swap\n");
 924                         error = -ENOSPC;
 925                         goto out_finish;
 926                 }
 927         }
 928         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 929         error = snapshot_read_next(&snapshot);
 930         if (error < PAGE_SIZE) {
 931                 if (error >= 0)
 932                         error = -EFAULT;
 933
 934                 goto out_finish;
 935         }
 936         header = (struct swsusp_info *)data_of(snapshot);
 937         error = swap_write_page(&handle, header, NULL);
 938         if (!error) {
 939                 error = (flags & SF_NOCOMPRESS_MODE) ?
 940                         save_image(&handle, &snapshot, pages - 1) :
 941                         save_image_lzo(&handle, &snapshot, pages - 1);
 942         }
 943 out_finish:
 944         error = swap_writer_finish(&handle, flags, error);
 945         return error;
 946 }
 947
 948 /**
 949  *      The following functions allow us to read data using a swap map
 950  *      in a file-alike way
 951  */
 952
 953 static void release_swap_reader(struct swap_map_handle *handle)
 954 {
 955         struct swap_map_page_list *tmp;
 956
 957         while (handle->maps) {
 958                 if (handle->maps->map)
 959                         free_page((unsigned long)handle->maps->map);
 960                 tmp = handle->maps;
 961                 handle->maps = handle->maps->next;
 962                 kfree(tmp);
 963         }
 964         handle->cur = NULL;
 965 }
 966
 967 static int get_swap_reader(struct swap_map_handle *handle,
 968                 unsigned int *flags_p)
 969 {
 970         int error;
 971         struct swap_map_page_list *tmp, *last;
 972         sector_t offset;
 973
 974         *flags_p = swsusp_header->flags;
 975
 976         if (!swsusp_header->image) /* how can this happen? */
 977                 return -EINVAL;
 978
 979         handle->cur = NULL;
 980         last = handle->maps = NULL;
 981         offset = swsusp_header->image;
 982         while (offset) {
 983                 tmp = kmalloc(sizeof(*handle->maps), GFP_KERNEL);
 984                 if (!tmp) {
 985                         release_swap_reader(handle);
 986                         return -ENOMEM;
 987                 }
 988                 memset(tmp, 0, sizeof(*tmp));
 989                 if (!handle->maps)
 990                         handle->maps = tmp;
 991                 if (last)
 992                         last->next = tmp;
 993                 last = tmp;
 994
 995                 tmp->map = (struct swap_map_page *)
 996                            __get_free_page(__GFP_RECLAIM | __GFP_HIGH);
 997                 if (!tmp->map) {
 998                         release_swap_reader(handle);
 999                         return -ENOMEM;
1000                 }
1001
1002                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1003                 if (error) {
1004                         release_swap_reader(handle);
1005                         return error;
1006                 }
1007                 offset = tmp->map->next_swap;
1008         }
1009         handle->k = 0;
1010         handle->cur = handle->maps->map;
1011         return 0;
1012 }
1013
1014 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1015                 struct hib_bio_batch *hb)
1016 {
1017         sector_t offset;
1018         int error;
1019         struct swap_map_page_list *tmp;
1020
1021         if (!handle->cur)
1022                 return -EINVAL;
1023         offset = handle->cur->entries[handle->k];
1024         if (!offset)
1025                 return -EFAULT;
1026         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1027         if (error)
1028                 return error;
1029         if (++handle->k >= MAP_PAGE_ENTRIES) {
1030                 handle->k = 0;
1031                 free_page((unsigned long)handle->maps->map);
1032                 tmp = handle->maps;
1033                 handle->maps = handle->maps->next;
1034                 kfree(tmp);
1035                 if (!handle->maps)
1036                         release_swap_reader(handle);
1037                 else
1038                         handle->cur = handle->maps->map;
1039         }
1040         return error;
1041 }
1042
1043 static int swap_reader_finish(struct swap_map_handle *handle)
1044 {
1045         release_swap_reader(handle);
1046
1047         return 0;
1048 }
1049
1050 /**
1051  *      load_image - load the image using the swap map handle
1052  *      @handle and the snapshot handle @snapshot
1053  *      (assume there are @nr_pages pages to load)
1054  */
1055
1056 static int load_image(struct swap_map_handle *handle,
1057                       struct snapshot_handle *snapshot,
1058                       unsigned int nr_to_read)
1059 {
1060         unsigned int m;
1061         int ret = 0;
1062         ktime_t start;
1063         ktime_t stop;
1064         struct hib_bio_batch hb;
1065         int err2;
1066         unsigned nr_pages;
1067
1068         hib_init_batch(&hb);
1069
1070         clean_pages_on_read = true;
1071         printk(KERN_INFO "PM: Loading image data pages (%u pages)...\n",
1072                 nr_to_read);
1073         m = nr_to_read / 10;
1074         if (!m)
1075                 m = 1;
1076         nr_pages = 0;
1077         start = ktime_get();
1078         for ( ; ; ) {
1079                 ret = snapshot_write_next(snapshot);
1080                 if (ret <= 0)
1081                         break;
1082                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1083                 if (ret)
1084                         break;
1085                 if (snapshot->sync_read)
1086                         ret = hib_wait_io(&hb);
1087                 if (ret)
1088                         break;
1089                 if (!(nr_pages % m))
1090                         printk(KERN_INFO "PM: Image loading progress: %3d%%\n",
1091                                nr_pages / m * 10);
1092                 nr_pages++;
1093         }
1094         err2 = hib_wait_io(&hb);
1095         stop = ktime_get();
1096         if (!ret)
1097                 ret = err2;
1098         if (!ret) {
1099                 printk(KERN_INFO "PM: Image loading done.\n");
1100                 snapshot_write_finalize(snapshot);
1101                 if (!snapshot_image_loaded(snapshot))
1102                         ret = -ENODATA;
1103         }
1104         swsusp_show_speed(start, stop, nr_to_read, "Read");
1105         return ret;
1106 }
1107
1108 /**
1109  * Structure used for LZO data decompression.
1110  */
1111 struct dec_data {
1112         struct task_struct *thr;                  /* thread */
1113         atomic_t ready;                           /* ready to start flag */
1114         atomic_t stop;                            /* ready to stop flag */
1115         int ret;                                  /* return code */
1116         wait_queue_head_t go;                     /* start decompression */
1117         wait_queue_head_t done;                   /* decompression done */
1118         size_t unc_len;                           /* uncompressed length */
1119         size_t cmp_len;                           /* compressed length */
1120         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1121         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1122 };
1123
1124 /**
1125  * Deompression function that runs in its own thread.
1126  */
1127 static int lzo_decompress_threadfn(void *data)
1128 {
1129         struct dec_data *d = data;
1130
1131         while (1) {
1132                 wait_event(d->go, atomic_read(&d->ready) ||
1133                                   kthread_should_stop());
1134                 if (kthread_should_stop()) {
1135                         d->thr = NULL;
1136                         d->ret = -1;
1137                         atomic_set(&d->stop, 1);
1138                         wake_up(&d->done);
1139                         break;
1140                 }
1141                 atomic_set(&d->ready, 0);
1142
1143                 d->unc_len = LZO_UNC_SIZE;
1144                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1145                                                d->unc, &d->unc_len);
1146                 if (clean_pages_on_decompress)
1147                         flush_icache_range((unsigned long)d->unc,
1148                                            (unsigned long)d->unc + d->unc_len);
1149
1150                 atomic_set(&d->stop, 1);
1151                 wake_up(&d->done);
1152         }
1153         return 0;
1154 }
1155
1156 /**
1157  * load_image_lzo - Load compressed image data and decompress them with LZO.
1158  * @handle: Swap map handle to use for loading data.
1159  * @snapshot: Image to copy uncompressed data into.
1160  * @nr_to_read: Number of pages to load.
1161  */
1162 static int load_image_lzo(struct swap_map_handle *handle,
1163                           struct snapshot_handle *snapshot,
1164                           unsigned int nr_to_read)
1165 {
1166         unsigned int m;
1167         int ret = 0;
1168         int eof = 0;
1169         struct hib_bio_batch hb;
1170         ktime_t start;
1171         ktime_t stop;
1172         unsigned nr_pages;
1173         size_t off;
1174         unsigned i, thr, run_threads, nr_threads;
1175         unsigned ring = 0, pg = 0, ring_size = 0,
1176                  have = 0, want, need, asked = 0;
1177         unsigned long read_pages = 0;
1178         unsigned char **page = NULL;
1179         struct dec_data *data = NULL;
1180         struct crc_data *crc = NULL;
1181
1182         hib_init_batch(&hb);
1183
1184         /*
1185          * We'll limit the number of threads for decompression to limit memory
1186          * footprint.
1187          */
1188         nr_threads = num_online_cpus() - 1;
1189         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1190
1191         page = vmalloc(sizeof(*page) * LZO_MAX_RD_PAGES);
1192         if (!page) {
1193                 printk(KERN_ERR "PM: Failed to allocate LZO page\n");
1194                 ret = -ENOMEM;
1195                 goto out_clean;
1196         }
1197
1198         data = vmalloc(sizeof(*data) * nr_threads);
1199         if (!data) {
1200                 printk(KERN_ERR "PM: Failed to allocate LZO data\n");
1201                 ret = -ENOMEM;
1202                 goto out_clean;
1203         }
1204         for (thr = 0; thr < nr_threads; thr++)
1205                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1206
1207         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1208         if (!crc) {
1209                 printk(KERN_ERR "PM: Failed to allocate crc\n");
1210                 ret = -ENOMEM;
1211                 goto out_clean;
1212         }
1213         memset(crc, 0, offsetof(struct crc_data, go));
1214
1215         clean_pages_on_decompress = true;
1216
1217         /*
1218          * Start the decompression threads.
1219          */
1220         for (thr = 0; thr < nr_threads; thr++) {
1221                 init_waitqueue_head(&data[thr].go);
1222                 init_waitqueue_head(&data[thr].done);
1223
1224                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1225                                             &data[thr],
1226                                             "image_decompress/%u", thr);
1227                 if (IS_ERR(data[thr].thr)) {
1228                         data[thr].thr = NULL;
1229                         printk(KERN_ERR
1230                                "PM: Cannot start decompression threads\n");
1231                         ret = -ENOMEM;
1232                         goto out_clean;
1233                 }
1234         }
1235
1236         /*
1237          * Start the CRC32 thread.
1238          */
1239         init_waitqueue_head(&crc->go);
1240         init_waitqueue_head(&crc->done);
1241
1242         handle->crc32 = 0;
1243         crc->crc32 = &handle->crc32;
1244         for (thr = 0; thr < nr_threads; thr++) {
1245                 crc->unc[thr] = data[thr].unc;
1246                 crc->unc_len[thr] = &data[thr].unc_len;
1247         }
1248
1249         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1250         if (IS_ERR(crc->thr)) {
1251                 crc->thr = NULL;
1252                 printk(KERN_ERR "PM: Cannot start CRC32 thread\n");
1253                 ret = -ENOMEM;
1254                 goto out_clean;
1255         }
1256
1257         /*
1258          * Set the number of pages for read buffering.
1259          * This is complete guesswork, because we'll only know the real
1260          * picture once prepare_image() is called, which is much later on
1261          * during the image load phase. We'll assume the worst case and
1262          * say that none of the image pages are from high memory.
1263          */
1264         if (low_free_pages() > snapshot_get_image_size())
1265                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1266         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1267
1268         for (i = 0; i < read_pages; i++) {
1269                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1270                                                   __GFP_RECLAIM | __GFP_HIGH :
1271                                                   __GFP_RECLAIM | __GFP_NOWARN |
1272                                                   __GFP_NORETRY);
1273
1274                 if (!page[i]) {
1275                         if (i < LZO_CMP_PAGES) {
1276                                 ring_size = i;
1277                                 printk(KERN_ERR
1278                                        "PM: Failed to allocate LZO pages\n");
1279                                 ret = -ENOMEM;
1280                                 goto out_clean;
1281                         } else {
1282                                 break;
1283                         }
1284                 }
1285         }
1286         want = ring_size = i;
1287
1288         printk(KERN_INFO
1289                 "PM: Using %u thread(s) for decompression.\n"
1290                 "PM: Loading and decompressing image data (%u pages)...\n",
1291                 nr_threads, nr_to_read);
1292         m = nr_to_read / 10;
1293         if (!m)
1294                 m = 1;
1295         nr_pages = 0;
1296         start = ktime_get();
1297
1298         ret = snapshot_write_next(snapshot);
1299         if (ret <= 0)
1300                 goto out_finish;
1301
1302         for(;;) {
1303                 for (i = 0; !eof && i < want; i++) {
1304                         ret = swap_read_page(handle, page[ring], &hb);
1305                         if (ret) {
1306                                 /*
1307                                  * On real read error, finish. On end of data,
1308                                  * set EOF flag and just exit the read loop.
1309                                  */
1310                                 if (handle->cur &&
1311                                     handle->cur->entries[handle->k]) {
1312                                         goto out_finish;
1313                                 } else {
1314                                         eof = 1;
1315                                         break;
1316                                 }
1317                         }
1318                         if (++ring >= ring_size)
1319                                 ring = 0;
1320                 }
1321                 asked += i;
1322                 want -= i;
1323
1324                 /*
1325                  * We are out of data, wait for some more.
1326                  */
1327                 if (!have) {
1328                         if (!asked)
1329                                 break;
1330
1331                         ret = hib_wait_io(&hb);
1332                         if (ret)
1333                                 goto out_finish;
1334                         have += asked;
1335                         asked = 0;
1336                         if (eof)
1337                                 eof = 2;
1338                 }
1339
1340                 if (crc->run_threads) {
1341                         wait_event(crc->done, atomic_read(&crc->stop));
1342                         atomic_set(&crc->stop, 0);
1343                         crc->run_threads = 0;
1344                 }
1345
1346                 for (thr = 0; have && thr < nr_threads; thr++) {
1347                         data[thr].cmp_len = *(size_t *)page[pg];
1348                         if (unlikely(!data[thr].cmp_len ||
1349                                      data[thr].cmp_len >
1350                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1351                                 printk(KERN_ERR
1352                                        "PM: Invalid LZO compressed length\n");
1353                                 ret = -1;
1354                                 goto out_finish;
1355                         }
1356
1357                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1358                                             PAGE_SIZE);
1359                         if (need > have) {
1360                                 if (eof > 1) {
1361                                         ret = -1;
1362                                         goto out_finish;
1363                                 }
1364                                 break;
1365                         }
1366
1367                         for (off = 0;
1368                              off < LZO_HEADER + data[thr].cmp_len;
1369                              off += PAGE_SIZE) {
1370                                 memcpy(data[thr].cmp + off,
1371                                        page[pg], PAGE_SIZE);
1372                                 have--;
1373                                 want++;
1374                                 if (++pg >= ring_size)
1375                                         pg = 0;
1376                         }
1377
1378                         atomic_set(&data[thr].ready, 1);
1379                         wake_up(&data[thr].go);
1380                 }
1381
1382                 /*
1383                  * Wait for more data while we are decompressing.
1384                  */
1385                 if (have < LZO_CMP_PAGES && asked) {
1386                         ret = hib_wait_io(&hb);
1387                         if (ret)
1388                                 goto out_finish;
1389                         have += asked;
1390                         asked = 0;
1391                         if (eof)
1392                                 eof = 2;
1393                 }
1394
1395                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1396                         wait_event(data[thr].done,
1397                                    atomic_read(&data[thr].stop));
1398                         atomic_set(&data[thr].stop, 0);
1399
1400                         ret = data[thr].ret;
1401
1402                         if (ret < 0) {
1403                                 printk(KERN_ERR
1404                                        "PM: LZO decompression failed\n");
1405                                 goto out_finish;
1406                         }
1407
1408                         if (unlikely(!data[thr].unc_len ||
1409                                      data[thr].unc_len > LZO_UNC_SIZE ||
1410                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1411                                 printk(KERN_ERR
1412                                        "PM: Invalid LZO uncompressed length\n");
1413                                 ret = -1;
1414                                 goto out_finish;
1415                         }
1416
1417                         for (off = 0;
1418                              off < data[thr].unc_len; off += PAGE_SIZE) {
1419                                 memcpy(data_of(*snapshot),
1420                                        data[thr].unc + off, PAGE_SIZE);
1421
1422                                 if (!(nr_pages % m))
1423                                         printk(KERN_INFO
1424                                                "PM: Image loading progress: "
1425                                                "%3d%%\n",
1426                                                nr_pages / m * 10);
1427                                 nr_pages++;
1428
1429                                 ret = snapshot_write_next(snapshot);
1430                                 if (ret <= 0) {
1431                                         crc->run_threads = thr + 1;
1432                                         atomic_set(&crc->ready, 1);
1433                                         wake_up(&crc->go);
1434                                         goto out_finish;
1435                                 }
1436                         }
1437                 }
1438
1439                 crc->run_threads = thr;
1440                 atomic_set(&crc->ready, 1);
1441                 wake_up(&crc->go);
1442         }
1443
1444 out_finish:
1445         if (crc->run_threads) {
1446                 wait_event(crc->done, atomic_read(&crc->stop));
1447                 atomic_set(&crc->stop, 0);
1448         }
1449         stop = ktime_get();
1450         if (!ret) {
1451                 printk(KERN_INFO "PM: Image loading done.\n");
1452                 snapshot_write_finalize(snapshot);
1453                 if (!snapshot_image_loaded(snapshot))
1454                         ret = -ENODATA;
1455                 if (!ret) {
1456                         if (swsusp_header->flags & SF_CRC32_MODE) {
1457                                 if(handle->crc32 != swsusp_header->crc32) {
1458                                         printk(KERN_ERR
1459                                                "PM: Invalid image CRC32!\n");
1460                                         ret = -ENODATA;
1461                                 }
1462                         }
1463                 }
1464         }
1465         swsusp_show_speed(start, stop, nr_to_read, "Read");
1466 out_clean:
1467         for (i = 0; i < ring_size; i++)
1468                 free_page((unsigned long)page[i]);
1469         if (crc) {
1470                 if (crc->thr)
1471                         kthread_stop(crc->thr);
1472                 kfree(crc);
1473         }
1474         if (data) {
1475                 for (thr = 0; thr < nr_threads; thr++)
1476                         if (data[thr].thr)
1477                                 kthread_stop(data[thr].thr);
1478                 vfree(data);
1479         }
1480         vfree(page);
1481
1482         return ret;
1483 }
1484
1485 /**
1486  *      swsusp_read - read the hibernation image.
1487  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1488  *                be written into this memory location
1489  */
1490
1491 int swsusp_read(unsigned int *flags_p)
1492 {
1493         int error;
1494         struct swap_map_handle handle;
1495         struct snapshot_handle snapshot;
1496         struct swsusp_info *header;
1497
1498         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1499         error = snapshot_write_next(&snapshot);
1500         if (error < PAGE_SIZE)
1501                 return error < 0 ? error : -EFAULT;
1502         header = (struct swsusp_info *)data_of(snapshot);
1503         error = get_swap_reader(&handle, flags_p);
1504         if (error)
1505                 goto end;
1506         if (!error)
1507                 error = swap_read_page(&handle, header, NULL);
1508         if (!error) {
1509                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1510                         load_image(&handle, &snapshot, header->pages - 1) :
1511                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1512         }
1513         swap_reader_finish(&handle);
1514 end:
1515         if (!error)
1516                 pr_debug("PM: Image successfully loaded\n");
1517         else
1518                 pr_debug("PM: Error %d resuming\n", error);
1519         return error;
1520 }
1521
1522 /**
1523  *      swsusp_check - Check for swsusp signature in the resume device
1524  */
1525
1526 int swsusp_check(void)
1527 {
1528         int error;
1529
1530         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1531                                             FMODE_READ, NULL);
1532         if (!IS_ERR(hib_resume_bdev)) {
1533                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1534                 clear_page(swsusp_header);
1535                 error = hib_submit_io(REQ_OP_READ, 0,
1536                                         swsusp_resume_block,
1537                                         swsusp_header, NULL);
1538                 if (error)
1539                         goto put;
1540
1541                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1542                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1543                         /* Reset swap signature now */
1544                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1545                                                 swsusp_resume_block,
1546                                                 swsusp_header, NULL);
1547                 } else {
1548                         error = -EINVAL;
1549                 }
1550
1551 put:
1552                 if (error)
1553                         blkdev_put(hib_resume_bdev, FMODE_READ);
1554                 else
1555                         pr_debug("PM: Image signature found, resuming\n");
1556         } else {
1557                 error = PTR_ERR(hib_resume_bdev);
1558         }
1559
1560         if (error)
1561                 pr_debug("PM: Image not found (code %d)\n", error);
1562
1563         return error;
1564 }
1565
1566 /**
1567  *      swsusp_close - close swap device.
1568  */
1569
1570 void swsusp_close(fmode_t mode)
1571 {
1572         if (IS_ERR(hib_resume_bdev)) {
1573                 pr_debug("PM: Image device not initialised\n");
1574                 return;
1575         }
1576
1577         blkdev_put(hib_resume_bdev, mode);
1578 }
1579
1580 /**
1581  *      swsusp_unmark - Unmark swsusp signature in the resume device
1582  */
1583
1584 #ifdef CONFIG_SUSPEND
1585 int swsusp_unmark(void)
1586 {
1587         int error;
1588
1589         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1590                       swsusp_header, NULL);
1591         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1592                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1593                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1594                                         swsusp_resume_block,
1595                                         swsusp_header, NULL);
1596         } else {
1597                 printk(KERN_ERR "PM: Cannot find swsusp signature!\n");
1598                 error = -ENODEV;
1599         }
1600
1601         /*
1602          * We just returned from suspend, we don't need the image any more.
1603          */
1604         free_all_swap_pages(root_swap);
1605
1606         return error;
1607 }
1608 #endif
1609
1610 static int swsusp_header_init(void)
1611 {
1612         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1613         if (!swsusp_header)
1614                 panic("Could not allocate memory for swsusp_header\n");
1615         return 0;
1616 }
1617
1618 core_initcall(swsusp_header_init);