kernel/power/swap.c

   1 // SPDX-License-Identifier: GPL-2.0-only
   2 /*
   3  * linux/kernel/power/swap.c
   4  *
   5  * This file provides functions for reading the suspend image from
   6  * and writing it to a swap partition.
   7  *
   8  * Copyright (C) 1998,2001-2005 Pavel Machek <pavel@ucw.cz>
   9  * Copyright (C) 2006 Rafael J. Wysocki <rjw@sisk.pl>
  10  * Copyright (C) 2010-2012 Bojan Smojver <bojan@rexursive.com>
  11  */
  12
  13 #define pr_fmt(fmt) "PM: " fmt
  14
  15 #include <linux/module.h>
  16 #include <linux/file.h>
  17 #include <linux/delay.h>
  18 #include <linux/bitops.h>
  19 #include <linux/genhd.h>
  20 #include <linux/device.h>
  21 #include <linux/bio.h>
  22 #include <linux/blkdev.h>
  23 #include <linux/swap.h>
  24 #include <linux/swapops.h>
  25 #include <linux/pm.h>
  26 #include <linux/slab.h>
  27 #include <linux/lzo.h>
  28 #include <linux/vmalloc.h>
  29 #include <linux/cpumask.h>
  30 #include <linux/atomic.h>
  31 #include <linux/kthread.h>
  32 #include <linux/crc32.h>
  33 #include <linux/ktime.h>
  34
  35 #include "power.h"
  36
  37 #define HIBERNATE_SIG   "S1SUSPEND"
  38
  39 /*
  40  * When reading an {un,}compressed image, we may restore pages in place,
  41  * in which case some architectures need these pages cleaning before they
  42  * can be executed. We don't know which pages these may be, so clean the lot.
  43  */
  44 static bool clean_pages_on_read;
  45 static bool clean_pages_on_decompress;
  46
  47 /*
  48  *      The swap map is a data structure used for keeping track of each page
  49  *      written to a swap partition.  It consists of many swap_map_page
  50  *      structures that contain each an array of MAP_PAGE_ENTRIES swap entries.
  51  *      These structures are stored on the swap and linked together with the
  52  *      help of the .next_swap member.
  53  *
  54  *      The swap map is created during suspend.  The swap map pages are
  55  *      allocated and populated one at a time, so we only need one memory
  56  *      page to set up the entire structure.
  57  *
  58  *      During resume we pick up all swap_map_page structures into a list.
  59  */
  60
  61 #define MAP_PAGE_ENTRIES        (PAGE_SIZE / sizeof(sector_t) - 1)
  62
  63 /*
  64  * Number of free pages that are not high.
  65  */
  66 static inline unsigned long low_free_pages(void)
  67 {
  68         return nr_free_pages() - nr_free_highpages();
  69 }
  70
  71 /*
  72  * Number of pages required to be kept free while writing the image. Always
  73  * half of all available low pages before the writing starts.
  74  */
  75 static inline unsigned long reqd_free_pages(void)
  76 {
  77         return low_free_pages() / 2;
  78 }
  79
  80 struct swap_map_page {
  81         sector_t entries[MAP_PAGE_ENTRIES];
  82         sector_t next_swap;
  83 };
  84
  85 struct swap_map_page_list {
  86         struct swap_map_page *map;
  87         struct swap_map_page_list *next;
  88 };
  89
  90 /**
  91  *      The swap_map_handle structure is used for handling swap in
  92  *      a file-alike way
  93  */
  94
  95 struct swap_map_handle {
  96         struct swap_map_page *cur;
  97         struct swap_map_page_list *maps;
  98         sector_t cur_swap;
  99         sector_t first_sector;
 100         unsigned int k;
 101         unsigned long reqd_free_pages;
 102         u32 crc32;
 103 };
 104
 105 struct swsusp_header {
 106         char reserved[PAGE_SIZE - 20 - sizeof(sector_t) - sizeof(int) -
 107                       sizeof(u32)];
 108         u32     crc32;
 109         sector_t image;
 110         unsigned int flags;     /* Flags to pass to the "boot" kernel */
 111         char    orig_sig[10];
 112         char    sig[10];
 113 } __packed;
 114
 115 static struct swsusp_header *swsusp_header;
 116
 117 /**
 118  *      The following functions are used for tracing the allocated
 119  *      swap pages, so that they can be freed in case of an error.
 120  */
 121
 122 struct swsusp_extent {
 123         struct rb_node node;
 124         unsigned long start;
 125         unsigned long end;
 126 };
 127
 128 static struct rb_root swsusp_extents = RB_ROOT;
 129
 130 static int swsusp_extents_insert(unsigned long swap_offset)
 131 {
 132         struct rb_node **new = &(swsusp_extents.rb_node);
 133         struct rb_node *parent = NULL;
 134         struct swsusp_extent *ext;
 135
 136         /* Figure out where to put the new node */
 137         while (*new) {
 138                 ext = rb_entry(*new, struct swsusp_extent, node);
 139                 parent = *new;
 140                 if (swap_offset < ext->start) {
 141                         /* Try to merge */
 142                         if (swap_offset == ext->start - 1) {
 143                                 ext->start--;
 144                                 return 0;
 145                         }
 146                         new = &((*new)->rb_left);
 147                 } else if (swap_offset > ext->end) {
 148                         /* Try to merge */
 149                         if (swap_offset == ext->end + 1) {
 150                                 ext->end++;
 151                                 return 0;
 152                         }
 153                         new = &((*new)->rb_right);
 154                 } else {
 155                         /* It already is in the tree */
 156                         return -EINVAL;
 157                 }
 158         }
 159         /* Add the new node and rebalance the tree. */
 160         ext = kzalloc(sizeof(struct swsusp_extent), GFP_KERNEL);
 161         if (!ext)
 162                 return -ENOMEM;
 163
 164         ext->start = swap_offset;
 165         ext->end = swap_offset;
 166         rb_link_node(&ext->node, parent, new);
 167         rb_insert_color(&ext->node, &swsusp_extents);
 168         return 0;
 169 }
 170
 171 /**
 172  *      alloc_swapdev_block - allocate a swap page and register that it has
 173  *      been allocated, so that it can be freed in case of an error.
 174  */
 175
 176 sector_t alloc_swapdev_block(int swap)
 177 {
 178         unsigned long offset;
 179
 180         offset = swp_offset(get_swap_page_of_type(swap));
 181         if (offset) {
 182                 if (swsusp_extents_insert(offset))
 183                         swap_free(swp_entry(swap, offset));
 184                 else
 185                         return swapdev_block(swap, offset);
 186         }
 187         return 0;
 188 }
 189
 190 /**
 191  *      free_all_swap_pages - free swap pages allocated for saving image data.
 192  *      It also frees the extents used to register which swap entries had been
 193  *      allocated.
 194  */
 195
 196 void free_all_swap_pages(int swap)
 197 {
 198         struct rb_node *node;
 199
 200         while ((node = swsusp_extents.rb_node)) {
 201                 struct swsusp_extent *ext;
 202                 unsigned long offset;
 203
 204                 ext = rb_entry(node, struct swsusp_extent, node);
 205                 rb_erase(node, &swsusp_extents);
 206                 for (offset = ext->start; offset <= ext->end; offset++)
 207                         swap_free(swp_entry(swap, offset));
 208
 209                 kfree(ext);
 210         }
 211 }
 212
 213 int swsusp_swap_in_use(void)
 214 {
 215         return (swsusp_extents.rb_node != NULL);
 216 }
 217
 218 /*
 219  * General things
 220  */
 221
 222 static unsigned short root_swap = 0xffff;
 223 static struct block_device *hib_resume_bdev;
 224
 225 struct hib_bio_batch {
 226         atomic_t                count;
 227         wait_queue_head_t       wait;
 228         blk_status_t            error;
 229         struct blk_plug         plug;
 230 };
 231
 232 static void hib_init_batch(struct hib_bio_batch *hb)
 233 {
 234         atomic_set(&hb->count, 0);
 235         init_waitqueue_head(&hb->wait);
 236         hb->error = BLK_STS_OK;
 237         blk_start_plug(&hb->plug);
 238 }
 239
 240 static void hib_finish_batch(struct hib_bio_batch *hb)
 241 {
 242         blk_finish_plug(&hb->plug);
 243 }
 244
 245 static void hib_end_io(struct bio *bio)
 246 {
 247         struct hib_bio_batch *hb = bio->bi_private;
 248         struct page *page = bio_first_page_all(bio);
 249
 250         if (bio->bi_status) {
 251                 pr_alert("Read-error on swap-device (%u:%u:%Lu)\n",
 252                          MAJOR(bio_dev(bio)), MINOR(bio_dev(bio)),
 253                          (unsigned long long)bio->bi_iter.bi_sector);
 254         }
 255
 256         if (bio_data_dir(bio) == WRITE)
 257                 put_page(page);
 258         else if (clean_pages_on_read)
 259                 flush_icache_range((unsigned long)page_address(page),
 260                                    (unsigned long)page_address(page) + PAGE_SIZE);
 261
 262         if (bio->bi_status && !hb->error)
 263                 hb->error = bio->bi_status;
 264         if (atomic_dec_and_test(&hb->count))
 265                 wake_up(&hb->wait);
 266
 267         bio_put(bio);
 268 }
 269
 270 static int hib_submit_io(int op, int op_flags, pgoff_t page_off, void *addr,
 271                 struct hib_bio_batch *hb)
 272 {
 273         struct page *page = virt_to_page(addr);
 274         struct bio *bio;
 275         int error = 0;
 276
 277         bio = bio_alloc(GFP_NOIO | __GFP_HIGH, 1);
 278         bio->bi_iter.bi_sector = page_off * (PAGE_SIZE >> 9);
 279         bio_set_dev(bio, hib_resume_bdev);
 280         bio_set_op_attrs(bio, op, op_flags);
 281
 282         if (bio_add_page(bio, page, PAGE_SIZE, 0) < PAGE_SIZE) {
 283                 pr_err("Adding page to bio failed at %llu\n",
 284                        (unsigned long long)bio->bi_iter.bi_sector);
 285                 bio_put(bio);
 286                 return -EFAULT;
 287         }
 288
 289         if (hb) {
 290                 bio->bi_end_io = hib_end_io;
 291                 bio->bi_private = hb;
 292                 atomic_inc(&hb->count);
 293                 submit_bio(bio);
 294         } else {
 295                 error = submit_bio_wait(bio);
 296                 bio_put(bio);
 297         }
 298
 299         return error;
 300 }
 301
 302 static blk_status_t hib_wait_io(struct hib_bio_batch *hb)
 303 {
 304         /*
 305          * We are relying on the behavior of blk_plug that a thread with
 306          * a plug will flush the plug list before sleeping.
 307          */
 308         wait_event(hb->wait, atomic_read(&hb->count) == 0);
 309         return blk_status_to_errno(hb->error);
 310 }
 311
 312 /*
 313  * Saving part
 314  */
 315
 316 static int mark_swapfiles(struct swap_map_handle *handle, unsigned int flags)
 317 {
 318         int error;
 319
 320         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
 321                       swsusp_header, NULL);
 322         if (!memcmp("SWAP-SPACE",swsusp_header->sig, 10) ||
 323             !memcmp("SWAPSPACE2",swsusp_header->sig, 10)) {
 324                 memcpy(swsusp_header->orig_sig,swsusp_header->sig, 10);
 325                 memcpy(swsusp_header->sig, HIBERNATE_SIG, 10);
 326                 swsusp_header->image = handle->first_sector;
 327                 swsusp_header->flags = flags;
 328                 if (flags & SF_CRC32_MODE)
 329                         swsusp_header->crc32 = handle->crc32;
 330                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
 331                                       swsusp_resume_block, swsusp_header, NULL);
 332         } else {
 333                 pr_err("Swap header not found!\n");
 334                 error = -ENODEV;
 335         }
 336         return error;
 337 }
 338
 339 /**
 340  *      swsusp_swap_check - check if the resume device is a swap device
 341  *      and get its index (if so)
 342  *
 343  *      This is called before saving image
 344  */
 345 static int swsusp_swap_check(void)
 346 {
 347         int res;
 348
 349         res = swap_type_of(swsusp_resume_device, swsusp_resume_block,
 350                         &hib_resume_bdev);
 351         if (res < 0)
 352                 return res;
 353
 354         root_swap = res;
 355         res = blkdev_get(hib_resume_bdev, FMODE_WRITE, NULL);
 356         if (res)
 357                 return res;
 358
 359         res = set_blocksize(hib_resume_bdev, PAGE_SIZE);
 360         if (res < 0)
 361                 blkdev_put(hib_resume_bdev, FMODE_WRITE);
 362
 363         /*
 364          * Update the resume device to the one actually used,
 365          * so the test_resume mode can use it in case it is
 366          * invoked from hibernate() to test the snapshot.
 367          */
 368         swsusp_resume_device = hib_resume_bdev->bd_dev;
 369         return res;
 370 }
 371
 372 /**
 373  *      write_page - Write one page to given swap location.
 374  *      @buf:           Address we're writing.
 375  *      @offset:        Offset of the swap page we're writing to.
 376  *      @hb:            bio completion batch
 377  */
 378
 379 static int write_page(void *buf, sector_t offset, struct hib_bio_batch *hb)
 380 {
 381         void *src;
 382         int ret;
 383
 384         if (!offset)
 385                 return -ENOSPC;
 386
 387         if (hb) {
 388                 src = (void *)__get_free_page(GFP_NOIO | __GFP_NOWARN |
 389                                               __GFP_NORETRY);
 390                 if (src) {
 391                         copy_page(src, buf);
 392                 } else {
 393                         ret = hib_wait_io(hb); /* Free pages */
 394                         if (ret)
 395                                 return ret;
 396                         src = (void *)__get_free_page(GFP_NOIO |
 397                                                       __GFP_NOWARN |
 398                                                       __GFP_NORETRY);
 399                         if (src) {
 400                                 copy_page(src, buf);
 401                         } else {
 402                                 WARN_ON_ONCE(1);
 403                                 hb = NULL;      /* Go synchronous */
 404                                 src = buf;
 405                         }
 406                 }
 407         } else {
 408                 src = buf;
 409         }
 410         return hib_submit_io(REQ_OP_WRITE, REQ_SYNC, offset, src, hb);
 411 }
 412
 413 static void release_swap_writer(struct swap_map_handle *handle)
 414 {
 415         if (handle->cur)
 416                 free_page((unsigned long)handle->cur);
 417         handle->cur = NULL;
 418 }
 419
 420 static int get_swap_writer(struct swap_map_handle *handle)
 421 {
 422         int ret;
 423
 424         ret = swsusp_swap_check();
 425         if (ret) {
 426                 if (ret != -ENOSPC)
 427                         pr_err("Cannot find swap device, try swapon -a\n");
 428                 return ret;
 429         }
 430         handle->cur = (struct swap_map_page *)get_zeroed_page(GFP_KERNEL);
 431         if (!handle->cur) {
 432                 ret = -ENOMEM;
 433                 goto err_close;
 434         }
 435         handle->cur_swap = alloc_swapdev_block(root_swap);
 436         if (!handle->cur_swap) {
 437                 ret = -ENOSPC;
 438                 goto err_rel;
 439         }
 440         handle->k = 0;
 441         handle->reqd_free_pages = reqd_free_pages();
 442         handle->first_sector = handle->cur_swap;
 443         return 0;
 444 err_rel:
 445         release_swap_writer(handle);
 446 err_close:
 447         swsusp_close(FMODE_WRITE);
 448         return ret;
 449 }
 450
 451 static int swap_write_page(struct swap_map_handle *handle, void *buf,
 452                 struct hib_bio_batch *hb)
 453 {
 454         int error = 0;
 455         sector_t offset;
 456
 457         if (!handle->cur)
 458                 return -EINVAL;
 459         offset = alloc_swapdev_block(root_swap);
 460         error = write_page(buf, offset, hb);
 461         if (error)
 462                 return error;
 463         handle->cur->entries[handle->k++] = offset;
 464         if (handle->k >= MAP_PAGE_ENTRIES) {
 465                 offset = alloc_swapdev_block(root_swap);
 466                 if (!offset)
 467                         return -ENOSPC;
 468                 handle->cur->next_swap = offset;
 469                 error = write_page(handle->cur, handle->cur_swap, hb);
 470                 if (error)
 471                         goto out;
 472                 clear_page(handle->cur);
 473                 handle->cur_swap = offset;
 474                 handle->k = 0;
 475
 476                 if (hb && low_free_pages() <= handle->reqd_free_pages) {
 477                         error = hib_wait_io(hb);
 478                         if (error)
 479                                 goto out;
 480                         /*
 481                          * Recalculate the number of required free pages, to
 482                          * make sure we never take more than half.
 483                          */
 484                         handle->reqd_free_pages = reqd_free_pages();
 485                 }
 486         }
 487  out:
 488         return error;
 489 }
 490
 491 static int flush_swap_writer(struct swap_map_handle *handle)
 492 {
 493         if (handle->cur && handle->cur_swap)
 494                 return write_page(handle->cur, handle->cur_swap, NULL);
 495         else
 496                 return -EINVAL;
 497 }
 498
 499 static int swap_writer_finish(struct swap_map_handle *handle,
 500                 unsigned int flags, int error)
 501 {
 502         if (!error) {
 503                 flush_swap_writer(handle);
 504                 pr_info("S");
 505                 error = mark_swapfiles(handle, flags);
 506                 pr_cont("|\n");
 507         }
 508
 509         if (error)
 510                 free_all_swap_pages(root_swap);
 511         release_swap_writer(handle);
 512         swsusp_close(FMODE_WRITE);
 513
 514         return error;
 515 }
 516
 517 /* We need to remember how much compressed data we need to read. */
 518 #define LZO_HEADER      sizeof(size_t)
 519
 520 /* Number of pages/bytes we'll compress at one time. */
 521 #define LZO_UNC_PAGES   32
 522 #define LZO_UNC_SIZE    (LZO_UNC_PAGES * PAGE_SIZE)
 523
 524 /* Number of pages/bytes we need for compressed data (worst case). */
 525 #define LZO_CMP_PAGES   DIV_ROUND_UP(lzo1x_worst_compress(LZO_UNC_SIZE) + \
 526                                      LZO_HEADER, PAGE_SIZE)
 527 #define LZO_CMP_SIZE    (LZO_CMP_PAGES * PAGE_SIZE)
 528
 529 /* Maximum number of threads for compression/decompression. */
 530 #define LZO_THREADS     3
 531
 532 /* Minimum/maximum number of pages for read buffering. */
 533 #define LZO_MIN_RD_PAGES        1024
 534 #define LZO_MAX_RD_PAGES        8192
 535
 536
 537 /**
 538  *      save_image - save the suspend image data
 539  */
 540
 541 static int save_image(struct swap_map_handle *handle,
 542                       struct snapshot_handle *snapshot,
 543                       unsigned int nr_to_write)
 544 {
 545         unsigned int m;
 546         int ret;
 547         int nr_pages;
 548         int err2;
 549         struct hib_bio_batch hb;
 550         ktime_t start;
 551         ktime_t stop;
 552
 553         hib_init_batch(&hb);
 554
 555         pr_info("Saving image data pages (%u pages)...\n",
 556                 nr_to_write);
 557         m = nr_to_write / 10;
 558         if (!m)
 559                 m = 1;
 560         nr_pages = 0;
 561         start = ktime_get();
 562         while (1) {
 563                 ret = snapshot_read_next(snapshot);
 564                 if (ret <= 0)
 565                         break;
 566                 ret = swap_write_page(handle, data_of(*snapshot), &hb);
 567                 if (ret)
 568                         break;
 569                 if (!(nr_pages % m))
 570                         pr_info("Image saving progress: %3d%%\n",
 571                                 nr_pages / m * 10);
 572                 nr_pages++;
 573         }
 574         err2 = hib_wait_io(&hb);
 575         hib_finish_batch(&hb);
 576         stop = ktime_get();
 577         if (!ret)
 578                 ret = err2;
 579         if (!ret)
 580                 pr_info("Image saving done\n");
 581         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 582         return ret;
 583 }
 584
 585 /**
 586  * Structure used for CRC32.
 587  */
 588 struct crc_data {
 589         struct task_struct *thr;                  /* thread */
 590         atomic_t ready;                           /* ready to start flag */
 591         atomic_t stop;                            /* ready to stop flag */
 592         unsigned run_threads;                     /* nr current threads */
 593         wait_queue_head_t go;                     /* start crc update */
 594         wait_queue_head_t done;                   /* crc update done */
 595         u32 *crc32;                               /* points to handle's crc32 */
 596         size_t *unc_len[LZO_THREADS];             /* uncompressed lengths */
 597         unsigned char *unc[LZO_THREADS];          /* uncompressed data */
 598 };
 599
 600 /**
 601  * CRC32 update function that runs in its own thread.
 602  */
 603 static int crc32_threadfn(void *data)
 604 {
 605         struct crc_data *d = data;
 606         unsigned i;
 607
 608         while (1) {
 609                 wait_event(d->go, atomic_read(&d->ready) ||
 610                                   kthread_should_stop());
 611                 if (kthread_should_stop()) {
 612                         d->thr = NULL;
 613                         atomic_set(&d->stop, 1);
 614                         wake_up(&d->done);
 615                         break;
 616                 }
 617                 atomic_set(&d->ready, 0);
 618
 619                 for (i = 0; i < d->run_threads; i++)
 620                         *d->crc32 = crc32_le(*d->crc32,
 621                                              d->unc[i], *d->unc_len[i]);
 622                 atomic_set(&d->stop, 1);
 623                 wake_up(&d->done);
 624         }
 625         return 0;
 626 }
 627 /**
 628  * Structure used for LZO data compression.
 629  */
 630 struct cmp_data {
 631         struct task_struct *thr;                  /* thread */
 632         atomic_t ready;                           /* ready to start flag */
 633         atomic_t stop;                            /* ready to stop flag */
 634         int ret;                                  /* return code */
 635         wait_queue_head_t go;                     /* start compression */
 636         wait_queue_head_t done;                   /* compression done */
 637         size_t unc_len;                           /* uncompressed length */
 638         size_t cmp_len;                           /* compressed length */
 639         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
 640         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
 641         unsigned char wrk[LZO1X_1_MEM_COMPRESS];  /* compression workspace */
 642 };
 643
 644 /**
 645  * Compression function that runs in its own thread.
 646  */
 647 static int lzo_compress_threadfn(void *data)
 648 {
 649         struct cmp_data *d = data;
 650
 651         while (1) {
 652                 wait_event(d->go, atomic_read(&d->ready) ||
 653                                   kthread_should_stop());
 654                 if (kthread_should_stop()) {
 655                         d->thr = NULL;
 656                         d->ret = -1;
 657                         atomic_set(&d->stop, 1);
 658                         wake_up(&d->done);
 659                         break;
 660                 }
 661                 atomic_set(&d->ready, 0);
 662
 663                 d->ret = lzo1x_1_compress(d->unc, d->unc_len,
 664                                           d->cmp + LZO_HEADER, &d->cmp_len,
 665                                           d->wrk);
 666                 atomic_set(&d->stop, 1);
 667                 wake_up(&d->done);
 668         }
 669         return 0;
 670 }
 671
 672 /**
 673  * save_image_lzo - Save the suspend image data compressed with LZO.
 674  * @handle: Swap map handle to use for saving the image.
 675  * @snapshot: Image to read data from.
 676  * @nr_to_write: Number of pages to save.
 677  */
 678 static int save_image_lzo(struct swap_map_handle *handle,
 679                           struct snapshot_handle *snapshot,
 680                           unsigned int nr_to_write)
 681 {
 682         unsigned int m;
 683         int ret = 0;
 684         int nr_pages;
 685         int err2;
 686         struct hib_bio_batch hb;
 687         ktime_t start;
 688         ktime_t stop;
 689         size_t off;
 690         unsigned thr, run_threads, nr_threads;
 691         unsigned char *page = NULL;
 692         struct cmp_data *data = NULL;
 693         struct crc_data *crc = NULL;
 694
 695         hib_init_batch(&hb);
 696
 697         /*
 698          * We'll limit the number of threads for compression to limit memory
 699          * footprint.
 700          */
 701         nr_threads = num_online_cpus() - 1;
 702         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
 703
 704         page = (void *)__get_free_page(GFP_NOIO | __GFP_HIGH);
 705         if (!page) {
 706                 pr_err("Failed to allocate LZO page\n");
 707                 ret = -ENOMEM;
 708                 goto out_clean;
 709         }
 710
 711         data = vmalloc(array_size(nr_threads, sizeof(*data)));
 712         if (!data) {
 713                 pr_err("Failed to allocate LZO data\n");
 714                 ret = -ENOMEM;
 715                 goto out_clean;
 716         }
 717         for (thr = 0; thr < nr_threads; thr++)
 718                 memset(&data[thr], 0, offsetof(struct cmp_data, go));
 719
 720         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
 721         if (!crc) {
 722                 pr_err("Failed to allocate crc\n");
 723                 ret = -ENOMEM;
 724                 goto out_clean;
 725         }
 726         memset(crc, 0, offsetof(struct crc_data, go));
 727
 728         /*
 729          * Start the compression threads.
 730          */
 731         for (thr = 0; thr < nr_threads; thr++) {
 732                 init_waitqueue_head(&data[thr].go);
 733                 init_waitqueue_head(&data[thr].done);
 734
 735                 data[thr].thr = kthread_run(lzo_compress_threadfn,
 736                                             &data[thr],
 737                                             "image_compress/%u", thr);
 738                 if (IS_ERR(data[thr].thr)) {
 739                         data[thr].thr = NULL;
 740                         pr_err("Cannot start compression threads\n");
 741                         ret = -ENOMEM;
 742                         goto out_clean;
 743                 }
 744         }
 745
 746         /*
 747          * Start the CRC32 thread.
 748          */
 749         init_waitqueue_head(&crc->go);
 750         init_waitqueue_head(&crc->done);
 751
 752         handle->crc32 = 0;
 753         crc->crc32 = &handle->crc32;
 754         for (thr = 0; thr < nr_threads; thr++) {
 755                 crc->unc[thr] = data[thr].unc;
 756                 crc->unc_len[thr] = &data[thr].unc_len;
 757         }
 758
 759         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
 760         if (IS_ERR(crc->thr)) {
 761                 crc->thr = NULL;
 762                 pr_err("Cannot start CRC32 thread\n");
 763                 ret = -ENOMEM;
 764                 goto out_clean;
 765         }
 766
 767         /*
 768          * Adjust the number of required free pages after all allocations have
 769          * been done. We don't want to run out of pages when writing.
 770          */
 771         handle->reqd_free_pages = reqd_free_pages();
 772
 773         pr_info("Using %u thread(s) for compression\n", nr_threads);
 774         pr_info("Compressing and saving image data (%u pages)...\n",
 775                 nr_to_write);
 776         m = nr_to_write / 10;
 777         if (!m)
 778                 m = 1;
 779         nr_pages = 0;
 780         start = ktime_get();
 781         for (;;) {
 782                 for (thr = 0; thr < nr_threads; thr++) {
 783                         for (off = 0; off < LZO_UNC_SIZE; off += PAGE_SIZE) {
 784                                 ret = snapshot_read_next(snapshot);
 785                                 if (ret < 0)
 786                                         goto out_finish;
 787
 788                                 if (!ret)
 789                                         break;
 790
 791                                 memcpy(data[thr].unc + off,
 792                                        data_of(*snapshot), PAGE_SIZE);
 793
 794                                 if (!(nr_pages % m))
 795                                         pr_info("Image saving progress: %3d%%\n",
 796                                                 nr_pages / m * 10);
 797                                 nr_pages++;
 798                         }
 799                         if (!off)
 800                                 break;
 801
 802                         data[thr].unc_len = off;
 803
 804                         atomic_set(&data[thr].ready, 1);
 805                         wake_up(&data[thr].go);
 806                 }
 807
 808                 if (!thr)
 809                         break;
 810
 811                 crc->run_threads = thr;
 812                 atomic_set(&crc->ready, 1);
 813                 wake_up(&crc->go);
 814
 815                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
 816                         wait_event(data[thr].done,
 817                                    atomic_read(&data[thr].stop));
 818                         atomic_set(&data[thr].stop, 0);
 819
 820                         ret = data[thr].ret;
 821
 822                         if (ret < 0) {
 823                                 pr_err("LZO compression failed\n");
 824                                 goto out_finish;
 825                         }
 826
 827                         if (unlikely(!data[thr].cmp_len ||
 828                                      data[thr].cmp_len >
 829                                      lzo1x_worst_compress(data[thr].unc_len))) {
 830                                 pr_err("Invalid LZO compressed length\n");
 831                                 ret = -1;
 832                                 goto out_finish;
 833                         }
 834
 835                         *(size_t *)data[thr].cmp = data[thr].cmp_len;
 836
 837                         /*
 838                          * Given we are writing one page at a time to disk, we
 839                          * copy that much from the buffer, although the last
 840                          * bit will likely be smaller than full page. This is
 841                          * OK - we saved the length of the compressed data, so
 842                          * any garbage at the end will be discarded when we
 843                          * read it.
 844                          */
 845                         for (off = 0;
 846                              off < LZO_HEADER + data[thr].cmp_len;
 847                              off += PAGE_SIZE) {
 848                                 memcpy(page, data[thr].cmp + off, PAGE_SIZE);
 849
 850                                 ret = swap_write_page(handle, page, &hb);
 851                                 if (ret)
 852                                         goto out_finish;
 853                         }
 854                 }
 855
 856                 wait_event(crc->done, atomic_read(&crc->stop));
 857                 atomic_set(&crc->stop, 0);
 858         }
 859
 860 out_finish:
 861         err2 = hib_wait_io(&hb);
 862         stop = ktime_get();
 863         if (!ret)
 864                 ret = err2;
 865         if (!ret)
 866                 pr_info("Image saving done\n");
 867         swsusp_show_speed(start, stop, nr_to_write, "Wrote");
 868 out_clean:
 869         hib_finish_batch(&hb);
 870         if (crc) {
 871                 if (crc->thr)
 872                         kthread_stop(crc->thr);
 873                 kfree(crc);
 874         }
 875         if (data) {
 876                 for (thr = 0; thr < nr_threads; thr++)
 877                         if (data[thr].thr)
 878                                 kthread_stop(data[thr].thr);
 879                 vfree(data);
 880         }
 881         if (page) free_page((unsigned long)page);
 882
 883         return ret;
 884 }
 885
 886 /**
 887  *      enough_swap - Make sure we have enough swap to save the image.
 888  *
 889  *      Returns TRUE or FALSE after checking the total amount of swap
 890  *      space avaiable from the resume partition.
 891  */
 892
 893 static int enough_swap(unsigned int nr_pages)
 894 {
 895         unsigned int free_swap = count_swap_pages(root_swap, 1);
 896         unsigned int required;
 897
 898         pr_debug("Free swap pages: %u\n", free_swap);
 899
 900         required = PAGES_FOR_IO + nr_pages;
 901         return free_swap > required;
 902 }
 903
 904 /**
 905  *      swsusp_write - Write entire image and metadata.
 906  *      @flags: flags to pass to the "boot" kernel in the image header
 907  *
 908  *      It is important _NOT_ to umount filesystems at this point. We want
 909  *      them synced (in case something goes wrong) but we DO not want to mark
 910  *      filesystem clean: it is not. (And it does not matter, if we resume
 911  *      correctly, we'll mark system clean, anyway.)
 912  */
 913
 914 int swsusp_write(unsigned int flags)
 915 {
 916         struct swap_map_handle handle;
 917         struct snapshot_handle snapshot;
 918         struct swsusp_info *header;
 919         unsigned long pages;
 920         int error;
 921
 922         pages = snapshot_get_image_size();
 923         error = get_swap_writer(&handle);
 924         if (error) {
 925                 pr_err("Cannot get swap writer\n");
 926                 return error;
 927         }
 928         if (flags & SF_NOCOMPRESS_MODE) {
 929                 if (!enough_swap(pages)) {
 930                         pr_err("Not enough free swap\n");
 931                         error = -ENOSPC;
 932                         goto out_finish;
 933                 }
 934         }
 935         memset(&snapshot, 0, sizeof(struct snapshot_handle));
 936         error = snapshot_read_next(&snapshot);
 937         if (error < (int)PAGE_SIZE) {
 938                 if (error >= 0)
 939                         error = -EFAULT;
 940
 941                 goto out_finish;
 942         }
 943         header = (struct swsusp_info *)data_of(snapshot);
 944         error = swap_write_page(&handle, header, NULL);
 945         if (!error) {
 946                 error = (flags & SF_NOCOMPRESS_MODE) ?
 947                         save_image(&handle, &snapshot, pages - 1) :
 948                         save_image_lzo(&handle, &snapshot, pages - 1);
 949         }
 950 out_finish:
 951         error = swap_writer_finish(&handle, flags, error);
 952         return error;
 953 }
 954
 955 /**
 956  *      The following functions allow us to read data using a swap map
 957  *      in a file-alike way
 958  */
 959
 960 static void release_swap_reader(struct swap_map_handle *handle)
 961 {
 962         struct swap_map_page_list *tmp;
 963
 964         while (handle->maps) {
 965                 if (handle->maps->map)
 966                         free_page((unsigned long)handle->maps->map);
 967                 tmp = handle->maps;
 968                 handle->maps = handle->maps->next;
 969                 kfree(tmp);
 970         }
 971         handle->cur = NULL;
 972 }
 973
 974 static int get_swap_reader(struct swap_map_handle *handle,
 975                 unsigned int *flags_p)
 976 {
 977         int error;
 978         struct swap_map_page_list *tmp, *last;
 979         sector_t offset;
 980
 981         *flags_p = swsusp_header->flags;
 982
 983         if (!swsusp_header->image) /* how can this happen? */
 984                 return -EINVAL;
 985
 986         handle->cur = NULL;
 987         last = handle->maps = NULL;
 988         offset = swsusp_header->image;
 989         while (offset) {
 990                 tmp = kzalloc(sizeof(*handle->maps), GFP_KERNEL);
 991                 if (!tmp) {
 992                         release_swap_reader(handle);
 993                         return -ENOMEM;
 994                 }
 995                 if (!handle->maps)
 996                         handle->maps = tmp;
 997                 if (last)
 998                         last->next = tmp;
 999                 last = tmp;
1000
1001                 tmp->map = (struct swap_map_page *)
1002                            __get_free_page(GFP_NOIO | __GFP_HIGH);
1003                 if (!tmp->map) {
1004                         release_swap_reader(handle);
1005                         return -ENOMEM;
1006                 }
1007
1008                 error = hib_submit_io(REQ_OP_READ, 0, offset, tmp->map, NULL);
1009                 if (error) {
1010                         release_swap_reader(handle);
1011                         return error;
1012                 }
1013                 offset = tmp->map->next_swap;
1014         }
1015         handle->k = 0;
1016         handle->cur = handle->maps->map;
1017         return 0;
1018 }
1019
1020 static int swap_read_page(struct swap_map_handle *handle, void *buf,
1021                 struct hib_bio_batch *hb)
1022 {
1023         sector_t offset;
1024         int error;
1025         struct swap_map_page_list *tmp;
1026
1027         if (!handle->cur)
1028                 return -EINVAL;
1029         offset = handle->cur->entries[handle->k];
1030         if (!offset)
1031                 return -EFAULT;
1032         error = hib_submit_io(REQ_OP_READ, 0, offset, buf, hb);
1033         if (error)
1034                 return error;
1035         if (++handle->k >= MAP_PAGE_ENTRIES) {
1036                 handle->k = 0;
1037                 free_page((unsigned long)handle->maps->map);
1038                 tmp = handle->maps;
1039                 handle->maps = handle->maps->next;
1040                 kfree(tmp);
1041                 if (!handle->maps)
1042                         release_swap_reader(handle);
1043                 else
1044                         handle->cur = handle->maps->map;
1045         }
1046         return error;
1047 }
1048
1049 static int swap_reader_finish(struct swap_map_handle *handle)
1050 {
1051         release_swap_reader(handle);
1052
1053         return 0;
1054 }
1055
1056 /**
1057  *      load_image - load the image using the swap map handle
1058  *      @handle and the snapshot handle @snapshot
1059  *      (assume there are @nr_pages pages to load)
1060  */
1061
1062 static int load_image(struct swap_map_handle *handle,
1063                       struct snapshot_handle *snapshot,
1064                       unsigned int nr_to_read)
1065 {
1066         unsigned int m;
1067         int ret = 0;
1068         ktime_t start;
1069         ktime_t stop;
1070         struct hib_bio_batch hb;
1071         int err2;
1072         unsigned nr_pages;
1073
1074         hib_init_batch(&hb);
1075
1076         clean_pages_on_read = true;
1077         pr_info("Loading image data pages (%u pages)...\n", nr_to_read);
1078         m = nr_to_read / 10;
1079         if (!m)
1080                 m = 1;
1081         nr_pages = 0;
1082         start = ktime_get();
1083         for ( ; ; ) {
1084                 ret = snapshot_write_next(snapshot);
1085                 if (ret <= 0)
1086                         break;
1087                 ret = swap_read_page(handle, data_of(*snapshot), &hb);
1088                 if (ret)
1089                         break;
1090                 if (snapshot->sync_read)
1091                         ret = hib_wait_io(&hb);
1092                 if (ret)
1093                         break;
1094                 if (!(nr_pages % m))
1095                         pr_info("Image loading progress: %3d%%\n",
1096                                 nr_pages / m * 10);
1097                 nr_pages++;
1098         }
1099         err2 = hib_wait_io(&hb);
1100         hib_finish_batch(&hb);
1101         stop = ktime_get();
1102         if (!ret)
1103                 ret = err2;
1104         if (!ret) {
1105                 pr_info("Image loading done\n");
1106                 snapshot_write_finalize(snapshot);
1107                 if (!snapshot_image_loaded(snapshot))
1108                         ret = -ENODATA;
1109         }
1110         swsusp_show_speed(start, stop, nr_to_read, "Read");
1111         return ret;
1112 }
1113
1114 /**
1115  * Structure used for LZO data decompression.
1116  */
1117 struct dec_data {
1118         struct task_struct *thr;                  /* thread */
1119         atomic_t ready;                           /* ready to start flag */
1120         atomic_t stop;                            /* ready to stop flag */
1121         int ret;                                  /* return code */
1122         wait_queue_head_t go;                     /* start decompression */
1123         wait_queue_head_t done;                   /* decompression done */
1124         size_t unc_len;                           /* uncompressed length */
1125         size_t cmp_len;                           /* compressed length */
1126         unsigned char unc[LZO_UNC_SIZE];          /* uncompressed buffer */
1127         unsigned char cmp[LZO_CMP_SIZE];          /* compressed buffer */
1128 };
1129
1130 /**
1131  * Deompression function that runs in its own thread.
1132  */
1133 static int lzo_decompress_threadfn(void *data)
1134 {
1135         struct dec_data *d = data;
1136
1137         while (1) {
1138                 wait_event(d->go, atomic_read(&d->ready) ||
1139                                   kthread_should_stop());
1140                 if (kthread_should_stop()) {
1141                         d->thr = NULL;
1142                         d->ret = -1;
1143                         atomic_set(&d->stop, 1);
1144                         wake_up(&d->done);
1145                         break;
1146                 }
1147                 atomic_set(&d->ready, 0);
1148
1149                 d->unc_len = LZO_UNC_SIZE;
1150                 d->ret = lzo1x_decompress_safe(d->cmp + LZO_HEADER, d->cmp_len,
1151                                                d->unc, &d->unc_len);
1152                 if (clean_pages_on_decompress)
1153                         flush_icache_range((unsigned long)d->unc,
1154                                            (unsigned long)d->unc + d->unc_len);
1155
1156                 atomic_set(&d->stop, 1);
1157                 wake_up(&d->done);
1158         }
1159         return 0;
1160 }
1161
1162 /**
1163  * load_image_lzo - Load compressed image data and decompress them with LZO.
1164  * @handle: Swap map handle to use for loading data.
1165  * @snapshot: Image to copy uncompressed data into.
1166  * @nr_to_read: Number of pages to load.
1167  */
1168 static int load_image_lzo(struct swap_map_handle *handle,
1169                           struct snapshot_handle *snapshot,
1170                           unsigned int nr_to_read)
1171 {
1172         unsigned int m;
1173         int ret = 0;
1174         int eof = 0;
1175         struct hib_bio_batch hb;
1176         ktime_t start;
1177         ktime_t stop;
1178         unsigned nr_pages;
1179         size_t off;
1180         unsigned i, thr, run_threads, nr_threads;
1181         unsigned ring = 0, pg = 0, ring_size = 0,
1182                  have = 0, want, need, asked = 0;
1183         unsigned long read_pages = 0;
1184         unsigned char **page = NULL;
1185         struct dec_data *data = NULL;
1186         struct crc_data *crc = NULL;
1187
1188         hib_init_batch(&hb);
1189
1190         /*
1191          * We'll limit the number of threads for decompression to limit memory
1192          * footprint.
1193          */
1194         nr_threads = num_online_cpus() - 1;
1195         nr_threads = clamp_val(nr_threads, 1, LZO_THREADS);
1196
1197         page = vmalloc(array_size(LZO_MAX_RD_PAGES, sizeof(*page)));
1198         if (!page) {
1199                 pr_err("Failed to allocate LZO page\n");
1200                 ret = -ENOMEM;
1201                 goto out_clean;
1202         }
1203
1204         data = vmalloc(array_size(nr_threads, sizeof(*data)));
1205         if (!data) {
1206                 pr_err("Failed to allocate LZO data\n");
1207                 ret = -ENOMEM;
1208                 goto out_clean;
1209         }
1210         for (thr = 0; thr < nr_threads; thr++)
1211                 memset(&data[thr], 0, offsetof(struct dec_data, go));
1212
1213         crc = kmalloc(sizeof(*crc), GFP_KERNEL);
1214         if (!crc) {
1215                 pr_err("Failed to allocate crc\n");
1216                 ret = -ENOMEM;
1217                 goto out_clean;
1218         }
1219         memset(crc, 0, offsetof(struct crc_data, go));
1220
1221         clean_pages_on_decompress = true;
1222
1223         /*
1224          * Start the decompression threads.
1225          */
1226         for (thr = 0; thr < nr_threads; thr++) {
1227                 init_waitqueue_head(&data[thr].go);
1228                 init_waitqueue_head(&data[thr].done);
1229
1230                 data[thr].thr = kthread_run(lzo_decompress_threadfn,
1231                                             &data[thr],
1232                                             "image_decompress/%u", thr);
1233                 if (IS_ERR(data[thr].thr)) {
1234                         data[thr].thr = NULL;
1235                         pr_err("Cannot start decompression threads\n");
1236                         ret = -ENOMEM;
1237                         goto out_clean;
1238                 }
1239         }
1240
1241         /*
1242          * Start the CRC32 thread.
1243          */
1244         init_waitqueue_head(&crc->go);
1245         init_waitqueue_head(&crc->done);
1246
1247         handle->crc32 = 0;
1248         crc->crc32 = &handle->crc32;
1249         for (thr = 0; thr < nr_threads; thr++) {
1250                 crc->unc[thr] = data[thr].unc;
1251                 crc->unc_len[thr] = &data[thr].unc_len;
1252         }
1253
1254         crc->thr = kthread_run(crc32_threadfn, crc, "image_crc32");
1255         if (IS_ERR(crc->thr)) {
1256                 crc->thr = NULL;
1257                 pr_err("Cannot start CRC32 thread\n");
1258                 ret = -ENOMEM;
1259                 goto out_clean;
1260         }
1261
1262         /*
1263          * Set the number of pages for read buffering.
1264          * This is complete guesswork, because we'll only know the real
1265          * picture once prepare_image() is called, which is much later on
1266          * during the image load phase. We'll assume the worst case and
1267          * say that none of the image pages are from high memory.
1268          */
1269         if (low_free_pages() > snapshot_get_image_size())
1270                 read_pages = (low_free_pages() - snapshot_get_image_size()) / 2;
1271         read_pages = clamp_val(read_pages, LZO_MIN_RD_PAGES, LZO_MAX_RD_PAGES);
1272
1273         for (i = 0; i < read_pages; i++) {
1274                 page[i] = (void *)__get_free_page(i < LZO_CMP_PAGES ?
1275                                                   GFP_NOIO | __GFP_HIGH :
1276                                                   GFP_NOIO | __GFP_NOWARN |
1277                                                   __GFP_NORETRY);
1278
1279                 if (!page[i]) {
1280                         if (i < LZO_CMP_PAGES) {
1281                                 ring_size = i;
1282                                 pr_err("Failed to allocate LZO pages\n");
1283                                 ret = -ENOMEM;
1284                                 goto out_clean;
1285                         } else {
1286                                 break;
1287                         }
1288                 }
1289         }
1290         want = ring_size = i;
1291
1292         pr_info("Using %u thread(s) for decompression\n", nr_threads);
1293         pr_info("Loading and decompressing image data (%u pages)...\n",
1294                 nr_to_read);
1295         m = nr_to_read / 10;
1296         if (!m)
1297                 m = 1;
1298         nr_pages = 0;
1299         start = ktime_get();
1300
1301         ret = snapshot_write_next(snapshot);
1302         if (ret <= 0)
1303                 goto out_finish;
1304
1305         for(;;) {
1306                 for (i = 0; !eof && i < want; i++) {
1307                         ret = swap_read_page(handle, page[ring], &hb);
1308                         if (ret) {
1309                                 /*
1310                                  * On real read error, finish. On end of data,
1311                                  * set EOF flag and just exit the read loop.
1312                                  */
1313                                 if (handle->cur &&
1314                                     handle->cur->entries[handle->k]) {
1315                                         goto out_finish;
1316                                 } else {
1317                                         eof = 1;
1318                                         break;
1319                                 }
1320                         }
1321                         if (++ring >= ring_size)
1322                                 ring = 0;
1323                 }
1324                 asked += i;
1325                 want -= i;
1326
1327                 /*
1328                  * We are out of data, wait for some more.
1329                  */
1330                 if (!have) {
1331                         if (!asked)
1332                                 break;
1333
1334                         ret = hib_wait_io(&hb);
1335                         if (ret)
1336                                 goto out_finish;
1337                         have += asked;
1338                         asked = 0;
1339                         if (eof)
1340                                 eof = 2;
1341                 }
1342
1343                 if (crc->run_threads) {
1344                         wait_event(crc->done, atomic_read(&crc->stop));
1345                         atomic_set(&crc->stop, 0);
1346                         crc->run_threads = 0;
1347                 }
1348
1349                 for (thr = 0; have && thr < nr_threads; thr++) {
1350                         data[thr].cmp_len = *(size_t *)page[pg];
1351                         if (unlikely(!data[thr].cmp_len ||
1352                                      data[thr].cmp_len >
1353                                      lzo1x_worst_compress(LZO_UNC_SIZE))) {
1354                                 pr_err("Invalid LZO compressed length\n");
1355                                 ret = -1;
1356                                 goto out_finish;
1357                         }
1358
1359                         need = DIV_ROUND_UP(data[thr].cmp_len + LZO_HEADER,
1360                                             PAGE_SIZE);
1361                         if (need > have) {
1362                                 if (eof > 1) {
1363                                         ret = -1;
1364                                         goto out_finish;
1365                                 }
1366                                 break;
1367                         }
1368
1369                         for (off = 0;
1370                              off < LZO_HEADER + data[thr].cmp_len;
1371                              off += PAGE_SIZE) {
1372                                 memcpy(data[thr].cmp + off,
1373                                        page[pg], PAGE_SIZE);
1374                                 have--;
1375                                 want++;
1376                                 if (++pg >= ring_size)
1377                                         pg = 0;
1378                         }
1379
1380                         atomic_set(&data[thr].ready, 1);
1381                         wake_up(&data[thr].go);
1382                 }
1383
1384                 /*
1385                  * Wait for more data while we are decompressing.
1386                  */
1387                 if (have < LZO_CMP_PAGES && asked) {
1388                         ret = hib_wait_io(&hb);
1389                         if (ret)
1390                                 goto out_finish;
1391                         have += asked;
1392                         asked = 0;
1393                         if (eof)
1394                                 eof = 2;
1395                 }
1396
1397                 for (run_threads = thr, thr = 0; thr < run_threads; thr++) {
1398                         wait_event(data[thr].done,
1399                                    atomic_read(&data[thr].stop));
1400                         atomic_set(&data[thr].stop, 0);
1401
1402                         ret = data[thr].ret;
1403
1404                         if (ret < 0) {
1405                                 pr_err("LZO decompression failed\n");
1406                                 goto out_finish;
1407                         }
1408
1409                         if (unlikely(!data[thr].unc_len ||
1410                                      data[thr].unc_len > LZO_UNC_SIZE ||
1411                                      data[thr].unc_len & (PAGE_SIZE - 1))) {
1412                                 pr_err("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                                         pr_info("Image loading progress: %3d%%\n",
1424                                                 nr_pages / m * 10);
1425                                 nr_pages++;
1426
1427                                 ret = snapshot_write_next(snapshot);
1428                                 if (ret <= 0) {
1429                                         crc->run_threads = thr + 1;
1430                                         atomic_set(&crc->ready, 1);
1431                                         wake_up(&crc->go);
1432                                         goto out_finish;
1433                                 }
1434                         }
1435                 }
1436
1437                 crc->run_threads = thr;
1438                 atomic_set(&crc->ready, 1);
1439                 wake_up(&crc->go);
1440         }
1441
1442 out_finish:
1443         if (crc->run_threads) {
1444                 wait_event(crc->done, atomic_read(&crc->stop));
1445                 atomic_set(&crc->stop, 0);
1446         }
1447         stop = ktime_get();
1448         if (!ret) {
1449                 pr_info("Image loading done\n");
1450                 snapshot_write_finalize(snapshot);
1451                 if (!snapshot_image_loaded(snapshot))
1452                         ret = -ENODATA;
1453                 if (!ret) {
1454                         if (swsusp_header->flags & SF_CRC32_MODE) {
1455                                 if(handle->crc32 != swsusp_header->crc32) {
1456                                         pr_err("Invalid image CRC32!\n");
1457                                         ret = -ENODATA;
1458                                 }
1459                         }
1460                 }
1461         }
1462         swsusp_show_speed(start, stop, nr_to_read, "Read");
1463 out_clean:
1464         hib_finish_batch(&hb);
1465         for (i = 0; i < ring_size; i++)
1466                 free_page((unsigned long)page[i]);
1467         if (crc) {
1468                 if (crc->thr)
1469                         kthread_stop(crc->thr);
1470                 kfree(crc);
1471         }
1472         if (data) {
1473                 for (thr = 0; thr < nr_threads; thr++)
1474                         if (data[thr].thr)
1475                                 kthread_stop(data[thr].thr);
1476                 vfree(data);
1477         }
1478         vfree(page);
1479
1480         return ret;
1481 }
1482
1483 /**
1484  *      swsusp_read - read the hibernation image.
1485  *      @flags_p: flags passed by the "frozen" kernel in the image header should
1486  *                be written into this memory location
1487  */
1488
1489 int swsusp_read(unsigned int *flags_p)
1490 {
1491         int error;
1492         struct swap_map_handle handle;
1493         struct snapshot_handle snapshot;
1494         struct swsusp_info *header;
1495
1496         memset(&snapshot, 0, sizeof(struct snapshot_handle));
1497         error = snapshot_write_next(&snapshot);
1498         if (error < (int)PAGE_SIZE)
1499                 return error < 0 ? error : -EFAULT;
1500         header = (struct swsusp_info *)data_of(snapshot);
1501         error = get_swap_reader(&handle, flags_p);
1502         if (error)
1503                 goto end;
1504         if (!error)
1505                 error = swap_read_page(&handle, header, NULL);
1506         if (!error) {
1507                 error = (*flags_p & SF_NOCOMPRESS_MODE) ?
1508                         load_image(&handle, &snapshot, header->pages - 1) :
1509                         load_image_lzo(&handle, &snapshot, header->pages - 1);
1510         }
1511         swap_reader_finish(&handle);
1512 end:
1513         if (!error)
1514                 pr_debug("Image successfully loaded\n");
1515         else
1516                 pr_debug("Error %d resuming\n", error);
1517         return error;
1518 }
1519
1520 /**
1521  *      swsusp_check - Check for swsusp signature in the resume device
1522  */
1523
1524 int swsusp_check(void)
1525 {
1526         int error;
1527
1528         hib_resume_bdev = blkdev_get_by_dev(swsusp_resume_device,
1529                                             FMODE_READ, NULL);
1530         if (!IS_ERR(hib_resume_bdev)) {
1531                 set_blocksize(hib_resume_bdev, PAGE_SIZE);
1532                 clear_page(swsusp_header);
1533                 error = hib_submit_io(REQ_OP_READ, 0,
1534                                         swsusp_resume_block,
1535                                         swsusp_header, NULL);
1536                 if (error)
1537                         goto put;
1538
1539                 if (!memcmp(HIBERNATE_SIG, swsusp_header->sig, 10)) {
1540                         memcpy(swsusp_header->sig, swsusp_header->orig_sig, 10);
1541                         /* Reset swap signature now */
1542                         error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1543                                                 swsusp_resume_block,
1544                                                 swsusp_header, NULL);
1545                 } else {
1546                         error = -EINVAL;
1547                 }
1548
1549 put:
1550                 if (error)
1551                         blkdev_put(hib_resume_bdev, FMODE_READ);
1552                 else
1553                         pr_debug("Image signature found, resuming\n");
1554         } else {
1555                 error = PTR_ERR(hib_resume_bdev);
1556         }
1557
1558         if (error)
1559                 pr_debug("Image not found (code %d)\n", error);
1560
1561         return error;
1562 }
1563
1564 /**
1565  *      swsusp_close - close swap device.
1566  */
1567
1568 void swsusp_close(fmode_t mode)
1569 {
1570         if (IS_ERR(hib_resume_bdev)) {
1571                 pr_debug("Image device not initialised\n");
1572                 return;
1573         }
1574
1575         blkdev_put(hib_resume_bdev, mode);
1576 }
1577
1578 /**
1579  *      swsusp_unmark - Unmark swsusp signature in the resume device
1580  */
1581
1582 #ifdef CONFIG_SUSPEND
1583 int swsusp_unmark(void)
1584 {
1585         int error;
1586
1587         hib_submit_io(REQ_OP_READ, 0, swsusp_resume_block,
1588                       swsusp_header, NULL);
1589         if (!memcmp(HIBERNATE_SIG,swsusp_header->sig, 10)) {
1590                 memcpy(swsusp_header->sig,swsusp_header->orig_sig, 10);
1591                 error = hib_submit_io(REQ_OP_WRITE, REQ_SYNC,
1592                                         swsusp_resume_block,
1593                                         swsusp_header, NULL);
1594         } else {
1595                 pr_err("Cannot find swsusp signature!\n");
1596                 error = -ENODEV;
1597         }
1598
1599         /*
1600          * We just returned from suspend, we don't need the image any more.
1601          */
1602         free_all_swap_pages(root_swap);
1603
1604         return error;
1605 }
1606 #endif
1607
1608 static int __init swsusp_header_init(void)
1609 {
1610         swsusp_header = (struct swsusp_header*) __get_free_page(GFP_KERNEL);
1611         if (!swsusp_header)
1612                 panic("Could not allocate memory for swsusp_header\n");
1613         return 0;
1614 }
1615
1616 core_initcall(swsusp_header_init);