fs/f2fs/compress.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * f2fs compress support
   4  *
   5  * Copyright (c) 2019 Chao Yu <chao@kernel.org>
   6  */
   7
   8 #include <linux/fs.h>
   9 #include <linux/f2fs_fs.h>
  10 #include <linux/writeback.h>
  11 #include <linux/backing-dev.h>
  12 #include <linux/lzo.h>
  13 #include <linux/lz4.h>
  14
  15 #include "f2fs.h"
  16 #include "node.h"
  17 #include <trace/events/f2fs.h>
  18
  19 struct f2fs_compress_ops {
  20         int (*init_compress_ctx)(struct compress_ctx *cc);
  21         void (*destroy_compress_ctx)(struct compress_ctx *cc);
  22         int (*compress_pages)(struct compress_ctx *cc);
  23         int (*decompress_pages)(struct decompress_io_ctx *dic);
  24 };
  25
  26 static unsigned int offset_in_cluster(struct compress_ctx *cc, pgoff_t index)
  27 {
  28         return index & (cc->cluster_size - 1);
  29 }
  30
  31 static pgoff_t cluster_idx(struct compress_ctx *cc, pgoff_t index)
  32 {
  33         return index >> cc->log_cluster_size;
  34 }
  35
  36 static pgoff_t start_idx_of_cluster(struct compress_ctx *cc)
  37 {
  38         return cc->cluster_idx << cc->log_cluster_size;
  39 }
  40
  41 bool f2fs_is_compressed_page(struct page *page)
  42 {
  43         if (!PagePrivate(page))
  44                 return false;
  45         if (!page_private(page))
  46                 return false;
  47         if (IS_ATOMIC_WRITTEN_PAGE(page) || IS_DUMMY_WRITTEN_PAGE(page))
  48                 return false;
  49         f2fs_bug_on(F2FS_M_SB(page->mapping),
  50                 *((u32 *)page_private(page)) != F2FS_COMPRESSED_PAGE_MAGIC);
  51         return true;
  52 }
  53
  54 static void f2fs_set_compressed_page(struct page *page,
  55                 struct inode *inode, pgoff_t index, void *data, refcount_t *r)
  56 {
  57         SetPagePrivate(page);
  58         set_page_private(page, (unsigned long)data);
  59
  60         /* i_crypto_info and iv index */
  61         page->index = index;
  62         page->mapping = inode->i_mapping;
  63         if (r)
  64                 refcount_inc(r);
  65 }
  66
  67 static void f2fs_put_compressed_page(struct page *page)
  68 {
  69         set_page_private(page, (unsigned long)NULL);
  70         ClearPagePrivate(page);
  71         page->mapping = NULL;
  72         unlock_page(page);
  73         put_page(page);
  74 }
  75
  76 static void f2fs_drop_rpages(struct compress_ctx *cc, int len, bool unlock)
  77 {
  78         int i;
  79
  80         for (i = 0; i < len; i++) {
  81                 if (!cc->rpages[i])
  82                         continue;
  83                 if (unlock)
  84                         unlock_page(cc->rpages[i]);
  85                 else
  86                         put_page(cc->rpages[i]);
  87         }
  88 }
  89
  90 static void f2fs_put_rpages(struct compress_ctx *cc)
  91 {
  92         f2fs_drop_rpages(cc, cc->cluster_size, false);
  93 }
  94
  95 static void f2fs_unlock_rpages(struct compress_ctx *cc, int len)
  96 {
  97         f2fs_drop_rpages(cc, len, true);
  98 }
  99
 100 static void f2fs_put_rpages_mapping(struct compress_ctx *cc,
 101                                 struct address_space *mapping,
 102                                 pgoff_t start, int len)
 103 {
 104         int i;
 105
 106         for (i = 0; i < len; i++) {
 107                 struct page *page = find_get_page(mapping, start + i);
 108
 109                 put_page(page);
 110                 put_page(page);
 111         }
 112 }
 113
 114 static void f2fs_put_rpages_wbc(struct compress_ctx *cc,
 115                 struct writeback_control *wbc, bool redirty, int unlock)
 116 {
 117         unsigned int i;
 118
 119         for (i = 0; i < cc->cluster_size; i++) {
 120                 if (!cc->rpages[i])
 121                         continue;
 122                 if (redirty)
 123                         redirty_page_for_writepage(wbc, cc->rpages[i]);
 124                 f2fs_put_page(cc->rpages[i], unlock);
 125         }
 126 }
 127
 128 struct page *f2fs_compress_control_page(struct page *page)
 129 {
 130         return ((struct compress_io_ctx *)page_private(page))->rpages[0];
 131 }
 132
 133 int f2fs_init_compress_ctx(struct compress_ctx *cc)
 134 {
 135         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 136
 137         if (cc->nr_rpages)
 138                 return 0;
 139
 140         cc->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
 141                                         cc->log_cluster_size, GFP_NOFS);
 142         return cc->rpages ? 0 : -ENOMEM;
 143 }
 144
 145 void f2fs_destroy_compress_ctx(struct compress_ctx *cc)
 146 {
 147         kfree(cc->rpages);
 148         cc->rpages = NULL;
 149         cc->nr_rpages = 0;
 150         cc->nr_cpages = 0;
 151         cc->cluster_idx = NULL_CLUSTER;
 152 }
 153
 154 void f2fs_compress_ctx_add_page(struct compress_ctx *cc, struct page *page)
 155 {
 156         unsigned int cluster_ofs;
 157
 158         if (!f2fs_cluster_can_merge_page(cc, page->index))
 159                 f2fs_bug_on(F2FS_I_SB(cc->inode), 1);
 160
 161         cluster_ofs = offset_in_cluster(cc, page->index);
 162         cc->rpages[cluster_ofs] = page;
 163         cc->nr_rpages++;
 164         cc->cluster_idx = cluster_idx(cc, page->index);
 165 }
 166
 167 #ifdef CONFIG_F2FS_FS_LZO
 168 static int lzo_init_compress_ctx(struct compress_ctx *cc)
 169 {
 170         cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
 171                                 LZO1X_MEM_COMPRESS, GFP_NOFS);
 172         if (!cc->private)
 173                 return -ENOMEM;
 174
 175         cc->clen = lzo1x_worst_compress(PAGE_SIZE << cc->log_cluster_size);
 176         return 0;
 177 }
 178
 179 static void lzo_destroy_compress_ctx(struct compress_ctx *cc)
 180 {
 181         kvfree(cc->private);
 182         cc->private = NULL;
 183 }
 184
 185 static int lzo_compress_pages(struct compress_ctx *cc)
 186 {
 187         int ret;
 188
 189         ret = lzo1x_1_compress(cc->rbuf, cc->rlen, cc->cbuf->cdata,
 190                                         &cc->clen, cc->private);
 191         if (ret != LZO_E_OK) {
 192                 printk_ratelimited("%sF2FS-fs (%s): lzo compress failed, ret:%d\n",
 193                                 KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id, ret);
 194                 return -EIO;
 195         }
 196         return 0;
 197 }
 198
 199 static int lzo_decompress_pages(struct decompress_io_ctx *dic)
 200 {
 201         int ret;
 202
 203         ret = lzo1x_decompress_safe(dic->cbuf->cdata, dic->clen,
 204                                                 dic->rbuf, &dic->rlen);
 205         if (ret != LZO_E_OK) {
 206                 printk_ratelimited("%sF2FS-fs (%s): lzo decompress failed, ret:%d\n",
 207                                 KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
 208                 return -EIO;
 209         }
 210
 211         if (dic->rlen != PAGE_SIZE << dic->log_cluster_size) {
 212                 printk_ratelimited("%sF2FS-fs (%s): lzo invalid rlen:%zu, "
 213                                         "expected:%lu\n", KERN_ERR,
 214                                         F2FS_I_SB(dic->inode)->sb->s_id,
 215                                         dic->rlen,
 216                                         PAGE_SIZE << dic->log_cluster_size);
 217                 return -EIO;
 218         }
 219         return 0;
 220 }
 221
 222 static const struct f2fs_compress_ops f2fs_lzo_ops = {
 223         .init_compress_ctx      = lzo_init_compress_ctx,
 224         .destroy_compress_ctx   = lzo_destroy_compress_ctx,
 225         .compress_pages         = lzo_compress_pages,
 226         .decompress_pages       = lzo_decompress_pages,
 227 };
 228 #endif
 229
 230 #ifdef CONFIG_F2FS_FS_LZ4
 231 static int lz4_init_compress_ctx(struct compress_ctx *cc)
 232 {
 233         cc->private = f2fs_kvmalloc(F2FS_I_SB(cc->inode),
 234                                 LZ4_MEM_COMPRESS, GFP_NOFS);
 235         if (!cc->private)
 236                 return -ENOMEM;
 237
 238         cc->clen = LZ4_compressBound(PAGE_SIZE << cc->log_cluster_size);
 239         return 0;
 240 }
 241
 242 static void lz4_destroy_compress_ctx(struct compress_ctx *cc)
 243 {
 244         kvfree(cc->private);
 245         cc->private = NULL;
 246 }
 247
 248 static int lz4_compress_pages(struct compress_ctx *cc)
 249 {
 250         int len;
 251
 252         len = LZ4_compress_default(cc->rbuf, cc->cbuf->cdata, cc->rlen,
 253                                                 cc->clen, cc->private);
 254         if (!len) {
 255                 printk_ratelimited("%sF2FS-fs (%s): lz4 compress failed\n",
 256                                 KERN_ERR, F2FS_I_SB(cc->inode)->sb->s_id);
 257                 return -EIO;
 258         }
 259         cc->clen = len;
 260         return 0;
 261 }
 262
 263 static int lz4_decompress_pages(struct decompress_io_ctx *dic)
 264 {
 265         int ret;
 266
 267         ret = LZ4_decompress_safe(dic->cbuf->cdata, dic->rbuf,
 268                                                 dic->clen, dic->rlen);
 269         if (ret < 0) {
 270                 printk_ratelimited("%sF2FS-fs (%s): lz4 decompress failed, ret:%d\n",
 271                                 KERN_ERR, F2FS_I_SB(dic->inode)->sb->s_id, ret);
 272                 return -EIO;
 273         }
 274
 275         if (ret != PAGE_SIZE << dic->log_cluster_size) {
 276                 printk_ratelimited("%sF2FS-fs (%s): lz4 invalid rlen:%zu, "
 277                                         "expected:%lu\n", KERN_ERR,
 278                                         F2FS_I_SB(dic->inode)->sb->s_id,
 279                                         dic->rlen,
 280                                         PAGE_SIZE << dic->log_cluster_size);
 281                 return -EIO;
 282         }
 283         return 0;
 284 }
 285
 286 static const struct f2fs_compress_ops f2fs_lz4_ops = {
 287         .init_compress_ctx      = lz4_init_compress_ctx,
 288         .destroy_compress_ctx   = lz4_destroy_compress_ctx,
 289         .compress_pages         = lz4_compress_pages,
 290         .decompress_pages       = lz4_decompress_pages,
 291 };
 292 #endif
 293
 294 static const struct f2fs_compress_ops *f2fs_cops[COMPRESS_MAX] = {
 295 #ifdef CONFIG_F2FS_FS_LZO
 296         &f2fs_lzo_ops,
 297 #else
 298         NULL,
 299 #endif
 300 #ifdef CONFIG_F2FS_FS_LZ4
 301         &f2fs_lz4_ops,
 302 #else
 303         NULL,
 304 #endif
 305 };
 306
 307 bool f2fs_is_compress_backend_ready(struct inode *inode)
 308 {
 309         if (!f2fs_compressed_file(inode))
 310                 return true;
 311         return f2fs_cops[F2FS_I(inode)->i_compress_algorithm];
 312 }
 313
 314 static struct page *f2fs_grab_page(void)
 315 {
 316         struct page *page;
 317
 318         page = alloc_page(GFP_NOFS);
 319         if (!page)
 320                 return NULL;
 321         lock_page(page);
 322         return page;
 323 }
 324
 325 static int f2fs_compress_pages(struct compress_ctx *cc)
 326 {
 327         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 328         struct f2fs_inode_info *fi = F2FS_I(cc->inode);
 329         const struct f2fs_compress_ops *cops =
 330                                 f2fs_cops[fi->i_compress_algorithm];
 331         unsigned int max_len, nr_cpages;
 332         int i, ret;
 333
 334         trace_f2fs_compress_pages_start(cc->inode, cc->cluster_idx,
 335                                 cc->cluster_size, fi->i_compress_algorithm);
 336
 337         ret = cops->init_compress_ctx(cc);
 338         if (ret)
 339                 goto out;
 340
 341         max_len = COMPRESS_HEADER_SIZE + cc->clen;
 342         cc->nr_cpages = DIV_ROUND_UP(max_len, PAGE_SIZE);
 343
 344         cc->cpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
 345                                         cc->nr_cpages, GFP_NOFS);
 346         if (!cc->cpages) {
 347                 ret = -ENOMEM;
 348                 goto destroy_compress_ctx;
 349         }
 350
 351         for (i = 0; i < cc->nr_cpages; i++) {
 352                 cc->cpages[i] = f2fs_grab_page();
 353                 if (!cc->cpages[i]) {
 354                         ret = -ENOMEM;
 355                         goto out_free_cpages;
 356                 }
 357         }
 358
 359         cc->rbuf = vmap(cc->rpages, cc->cluster_size, VM_MAP, PAGE_KERNEL_RO);
 360         if (!cc->rbuf) {
 361                 ret = -ENOMEM;
 362                 goto out_free_cpages;
 363         }
 364
 365         cc->cbuf = vmap(cc->cpages, cc->nr_cpages, VM_MAP, PAGE_KERNEL);
 366         if (!cc->cbuf) {
 367                 ret = -ENOMEM;
 368                 goto out_vunmap_rbuf;
 369         }
 370
 371         ret = cops->compress_pages(cc);
 372         if (ret)
 373                 goto out_vunmap_cbuf;
 374
 375         max_len = PAGE_SIZE * (cc->cluster_size - 1) - COMPRESS_HEADER_SIZE;
 376
 377         if (cc->clen > max_len) {
 378                 ret = -EAGAIN;
 379                 goto out_vunmap_cbuf;
 380         }
 381
 382         cc->cbuf->clen = cpu_to_le32(cc->clen);
 383         cc->cbuf->chksum = cpu_to_le32(0);
 384
 385         for (i = 0; i < COMPRESS_DATA_RESERVED_SIZE; i++)
 386                 cc->cbuf->reserved[i] = cpu_to_le32(0);
 387
 388         vunmap(cc->cbuf);
 389         vunmap(cc->rbuf);
 390
 391         nr_cpages = DIV_ROUND_UP(cc->clen + COMPRESS_HEADER_SIZE, PAGE_SIZE);
 392
 393         for (i = nr_cpages; i < cc->nr_cpages; i++) {
 394                 f2fs_put_compressed_page(cc->cpages[i]);
 395                 cc->cpages[i] = NULL;
 396         }
 397
 398         cc->nr_cpages = nr_cpages;
 399
 400         trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
 401                                                         cc->clen, ret);
 402         return 0;
 403
 404 out_vunmap_cbuf:
 405         vunmap(cc->cbuf);
 406 out_vunmap_rbuf:
 407         vunmap(cc->rbuf);
 408 out_free_cpages:
 409         for (i = 0; i < cc->nr_cpages; i++) {
 410                 if (cc->cpages[i])
 411                         f2fs_put_compressed_page(cc->cpages[i]);
 412         }
 413         kfree(cc->cpages);
 414         cc->cpages = NULL;
 415 destroy_compress_ctx:
 416         cops->destroy_compress_ctx(cc);
 417 out:
 418         trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
 419                                                         cc->clen, ret);
 420         return ret;
 421 }
 422
 423 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
 424 {
 425         struct decompress_io_ctx *dic =
 426                         (struct decompress_io_ctx *)page_private(page);
 427         struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
 428         struct f2fs_inode_info *fi= F2FS_I(dic->inode);
 429         const struct f2fs_compress_ops *cops =
 430                         f2fs_cops[fi->i_compress_algorithm];
 431         int ret;
 432
 433         dec_page_count(sbi, F2FS_RD_DATA);
 434
 435         if (bio->bi_status || PageError(page))
 436                 dic->failed = true;
 437
 438         if (refcount_dec_not_one(&dic->ref))
 439                 return;
 440
 441         trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
 442                                 dic->cluster_size, fi->i_compress_algorithm);
 443
 444         /* submit partial compressed pages */
 445         if (dic->failed) {
 446                 ret = -EIO;
 447                 goto out_free_dic;
 448         }
 449
 450         dic->rbuf = vmap(dic->tpages, dic->cluster_size, VM_MAP, PAGE_KERNEL);
 451         if (!dic->rbuf) {
 452                 ret = -ENOMEM;
 453                 goto out_free_dic;
 454         }
 455
 456         dic->cbuf = vmap(dic->cpages, dic->nr_cpages, VM_MAP, PAGE_KERNEL_RO);
 457         if (!dic->cbuf) {
 458                 ret = -ENOMEM;
 459                 goto out_vunmap_rbuf;
 460         }
 461
 462         dic->clen = le32_to_cpu(dic->cbuf->clen);
 463         dic->rlen = PAGE_SIZE << dic->log_cluster_size;
 464
 465         if (dic->clen > PAGE_SIZE * dic->nr_cpages - COMPRESS_HEADER_SIZE) {
 466                 ret = -EFSCORRUPTED;
 467                 goto out_vunmap_cbuf;
 468         }
 469
 470         ret = cops->decompress_pages(dic);
 471
 472 out_vunmap_cbuf:
 473         vunmap(dic->cbuf);
 474 out_vunmap_rbuf:
 475         vunmap(dic->rbuf);
 476 out_free_dic:
 477         if (!verity)
 478                 f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
 479                                                                 ret, false);
 480
 481         trace_f2fs_decompress_pages_end(dic->inode, dic->cluster_idx,
 482                                                         dic->clen, ret);
 483         if (!verity)
 484                 f2fs_free_dic(dic);
 485 }
 486
 487 static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
 488 {
 489         if (cc->cluster_idx == NULL_CLUSTER)
 490                 return true;
 491         return cc->cluster_idx == cluster_idx(cc, index);
 492 }
 493
 494 bool f2fs_cluster_is_empty(struct compress_ctx *cc)
 495 {
 496         return cc->nr_rpages == 0;
 497 }
 498
 499 static bool f2fs_cluster_is_full(struct compress_ctx *cc)
 500 {
 501         return cc->cluster_size == cc->nr_rpages;
 502 }
 503
 504 bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index)
 505 {
 506         if (f2fs_cluster_is_empty(cc))
 507                 return true;
 508         return is_page_in_cluster(cc, index);
 509 }
 510
 511 static bool __cluster_may_compress(struct compress_ctx *cc)
 512 {
 513         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 514         loff_t i_size = i_size_read(cc->inode);
 515         unsigned nr_pages = DIV_ROUND_UP(i_size, PAGE_SIZE);
 516         int i;
 517
 518         for (i = 0; i < cc->cluster_size; i++) {
 519                 struct page *page = cc->rpages[i];
 520
 521                 f2fs_bug_on(sbi, !page);
 522
 523                 if (unlikely(f2fs_cp_error(sbi)))
 524                         return false;
 525                 if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
 526                         return false;
 527
 528                 /* beyond EOF */
 529                 if (page->index >= nr_pages)
 530                         return false;
 531         }
 532         return true;
 533 }
 534
 535 /* return # of compressed block addresses */
 536 static int f2fs_compressed_blocks(struct compress_ctx *cc)
 537 {
 538         struct dnode_of_data dn;
 539         int ret;
 540
 541         set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 542         ret = f2fs_get_dnode_of_data(&dn, start_idx_of_cluster(cc),
 543                                                         LOOKUP_NODE);
 544         if (ret) {
 545                 if (ret == -ENOENT)
 546                         ret = 0;
 547                 goto fail;
 548         }
 549
 550         if (dn.data_blkaddr == COMPRESS_ADDR) {
 551                 int i;
 552
 553                 ret = 1;
 554                 for (i = 1; i < cc->cluster_size; i++) {
 555                         block_t blkaddr;
 556
 557                         blkaddr = datablock_addr(dn.inode,
 558                                         dn.node_page, dn.ofs_in_node + i);
 559                         if (blkaddr != NULL_ADDR)
 560                                 ret++;
 561                 }
 562         }
 563 fail:
 564         f2fs_put_dnode(&dn);
 565         return ret;
 566 }
 567
 568 int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index)
 569 {
 570         struct compress_ctx cc = {
 571                 .inode = inode,
 572                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 573                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 574                 .cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
 575         };
 576
 577         return f2fs_compressed_blocks(&cc);
 578 }
 579
 580 static bool cluster_may_compress(struct compress_ctx *cc)
 581 {
 582         if (!f2fs_compressed_file(cc->inode))
 583                 return false;
 584         if (f2fs_is_atomic_file(cc->inode))
 585                 return false;
 586         if (f2fs_is_mmap_file(cc->inode))
 587                 return false;
 588         if (!f2fs_cluster_is_full(cc))
 589                 return false;
 590         return __cluster_may_compress(cc);
 591 }
 592
 593 static void set_cluster_writeback(struct compress_ctx *cc)
 594 {
 595         int i;
 596
 597         for (i = 0; i < cc->cluster_size; i++) {
 598                 if (cc->rpages[i])
 599                         set_page_writeback(cc->rpages[i]);
 600         }
 601 }
 602
 603 static void set_cluster_dirty(struct compress_ctx *cc)
 604 {
 605         int i;
 606
 607         for (i = 0; i < cc->cluster_size; i++)
 608                 if (cc->rpages[i])
 609                         set_page_dirty(cc->rpages[i]);
 610 }
 611
 612 static int prepare_compress_overwrite(struct compress_ctx *cc,
 613                 struct page **pagep, pgoff_t index, void **fsdata)
 614 {
 615         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 616         struct address_space *mapping = cc->inode->i_mapping;
 617         struct page *page;
 618         struct dnode_of_data dn;
 619         sector_t last_block_in_bio;
 620         unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
 621         pgoff_t start_idx = start_idx_of_cluster(cc);
 622         int i, ret;
 623         bool prealloc;
 624
 625 retry:
 626         ret = f2fs_compressed_blocks(cc);
 627         if (ret <= 0)
 628                 return ret;
 629
 630         /* compressed case */
 631         prealloc = (ret < cc->cluster_size);
 632
 633         ret = f2fs_init_compress_ctx(cc);
 634         if (ret)
 635                 return ret;
 636
 637         /* keep page reference to avoid page reclaim */
 638         for (i = 0; i < cc->cluster_size; i++) {
 639                 page = f2fs_pagecache_get_page(mapping, start_idx + i,
 640                                                         fgp_flag, GFP_NOFS);
 641                 if (!page) {
 642                         ret = -ENOMEM;
 643                         goto unlock_pages;
 644                 }
 645
 646                 if (PageUptodate(page))
 647                         unlock_page(page);
 648                 else
 649                         f2fs_compress_ctx_add_page(cc, page);
 650         }
 651
 652         if (!f2fs_cluster_is_empty(cc)) {
 653                 struct bio *bio = NULL;
 654
 655                 ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
 656                                                 &last_block_in_bio, false);
 657                 f2fs_destroy_compress_ctx(cc);
 658                 if (ret)
 659                         goto release_pages;
 660                 if (bio)
 661                         f2fs_submit_bio(sbi, bio, DATA);
 662
 663                 ret = f2fs_init_compress_ctx(cc);
 664                 if (ret)
 665                         goto release_pages;
 666         }
 667
 668         for (i = 0; i < cc->cluster_size; i++) {
 669                 f2fs_bug_on(sbi, cc->rpages[i]);
 670
 671                 page = find_lock_page(mapping, start_idx + i);
 672                 f2fs_bug_on(sbi, !page);
 673
 674                 f2fs_wait_on_page_writeback(page, DATA, true, true);
 675
 676                 f2fs_compress_ctx_add_page(cc, page);
 677                 f2fs_put_page(page, 0);
 678
 679                 if (!PageUptodate(page)) {
 680                         f2fs_unlock_rpages(cc, i + 1);
 681                         f2fs_put_rpages_mapping(cc, mapping, start_idx,
 682                                         cc->cluster_size);
 683                         f2fs_destroy_compress_ctx(cc);
 684                         goto retry;
 685                 }
 686         }
 687
 688         if (prealloc) {
 689                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
 690
 691                 set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 692
 693                 for (i = cc->cluster_size - 1; i > 0; i--) {
 694                         ret = f2fs_get_block(&dn, start_idx + i);
 695                         if (ret) {
 696                                 i = cc->cluster_size;
 697                                 break;
 698                         }
 699
 700                         if (dn.data_blkaddr != NEW_ADDR)
 701                                 break;
 702                 }
 703
 704                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
 705         }
 706
 707         if (likely(!ret)) {
 708                 *fsdata = cc->rpages;
 709                 *pagep = cc->rpages[offset_in_cluster(cc, index)];
 710                 return cc->cluster_size;
 711         }
 712
 713 unlock_pages:
 714         f2fs_unlock_rpages(cc, i);
 715 release_pages:
 716         f2fs_put_rpages_mapping(cc, mapping, start_idx, i);
 717         f2fs_destroy_compress_ctx(cc);
 718         return ret;
 719 }
 720
 721 int f2fs_prepare_compress_overwrite(struct inode *inode,
 722                 struct page **pagep, pgoff_t index, void **fsdata)
 723 {
 724         struct compress_ctx cc = {
 725                 .inode = inode,
 726                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 727                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 728                 .cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
 729                 .rpages = NULL,
 730                 .nr_rpages = 0,
 731         };
 732
 733         return prepare_compress_overwrite(&cc, pagep, index, fsdata);
 734 }
 735
 736 bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
 737                                         pgoff_t index, unsigned copied)
 738
 739 {
 740         struct compress_ctx cc = {
 741                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 742                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 743                 .rpages = fsdata,
 744         };
 745         bool first_index = (index == cc.rpages[0]->index);
 746
 747         if (copied)
 748                 set_cluster_dirty(&cc);
 749
 750         f2fs_put_rpages_wbc(&cc, NULL, false, 1);
 751         f2fs_destroy_compress_ctx(&cc);
 752
 753         return first_index;
 754 }
 755
 756 static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 757                                         int *submitted,
 758                                         struct writeback_control *wbc,
 759                                         enum iostat_type io_type)
 760 {
 761         struct inode *inode = cc->inode;
 762         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 763         struct f2fs_inode_info *fi = F2FS_I(inode);
 764         struct f2fs_io_info fio = {
 765                 .sbi = sbi,
 766                 .ino = cc->inode->i_ino,
 767                 .type = DATA,
 768                 .op = REQ_OP_WRITE,
 769                 .op_flags = wbc_to_write_flags(wbc),
 770                 .old_blkaddr = NEW_ADDR,
 771                 .page = NULL,
 772                 .encrypted_page = NULL,
 773                 .compressed_page = NULL,
 774                 .submitted = false,
 775                 .need_lock = LOCK_RETRY,
 776                 .io_type = io_type,
 777                 .io_wbc = wbc,
 778                 .encrypted = f2fs_encrypted_file(cc->inode),
 779         };
 780         struct dnode_of_data dn;
 781         struct node_info ni;
 782         struct compress_io_ctx *cic;
 783         pgoff_t start_idx = start_idx_of_cluster(cc);
 784         unsigned int last_index = cc->cluster_size - 1;
 785         loff_t psize;
 786         int i, err;
 787
 788         set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 789
 790         f2fs_lock_op(sbi);
 791
 792         err = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
 793         if (err)
 794                 goto out_unlock_op;
 795
 796         for (i = 0; i < cc->cluster_size; i++) {
 797                 if (datablock_addr(dn.inode, dn.node_page,
 798                                         dn.ofs_in_node + i) == NULL_ADDR)
 799                         goto out_put_dnode;
 800         }
 801
 802         psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
 803
 804         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 805         if (err)
 806                 goto out_put_dnode;
 807
 808         fio.version = ni.version;
 809
 810         cic = f2fs_kzalloc(sbi, sizeof(struct compress_io_ctx), GFP_NOFS);
 811         if (!cic)
 812                 goto out_put_dnode;
 813
 814         cic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
 815         cic->inode = inode;
 816         refcount_set(&cic->ref, 1);
 817         cic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
 818                         cc->log_cluster_size, GFP_NOFS);
 819         if (!cic->rpages)
 820                 goto out_put_cic;
 821
 822         cic->nr_rpages = cc->cluster_size;
 823
 824         for (i = 0; i < cc->nr_cpages; i++) {
 825                 f2fs_set_compressed_page(cc->cpages[i], inode,
 826                                         cc->rpages[i + 1]->index,
 827                                         cic, i ? &cic->ref : NULL);
 828                 fio.compressed_page = cc->cpages[i];
 829                 if (fio.encrypted) {
 830                         fio.page = cc->rpages[i + 1];
 831                         err = f2fs_encrypt_one_page(&fio);
 832                         if (err)
 833                                 goto out_destroy_crypt;
 834                         cc->cpages[i] = fio.encrypted_page;
 835                 }
 836         }
 837
 838         set_cluster_writeback(cc);
 839
 840         for (i = 0; i < cc->cluster_size; i++)
 841                 cic->rpages[i] = cc->rpages[i];
 842
 843         for (i = 0; i < cc->cluster_size; i++, dn.ofs_in_node++) {
 844                 block_t blkaddr;
 845
 846                 blkaddr = datablock_addr(dn.inode, dn.node_page,
 847                                                         dn.ofs_in_node);
 848                 fio.page = cic->rpages[i];
 849                 fio.old_blkaddr = blkaddr;
 850
 851                 /* cluster header */
 852                 if (i == 0) {
 853                         if (blkaddr == COMPRESS_ADDR)
 854                                 fio.compr_blocks++;
 855                         if (__is_valid_data_blkaddr(blkaddr))
 856                                 f2fs_invalidate_blocks(sbi, blkaddr);
 857                         f2fs_update_data_blkaddr(&dn, COMPRESS_ADDR);
 858                         goto unlock_continue;
 859                 }
 860
 861                 if (fio.compr_blocks && __is_valid_data_blkaddr(blkaddr))
 862                         fio.compr_blocks++;
 863
 864                 if (i > cc->nr_cpages) {
 865                         if (__is_valid_data_blkaddr(blkaddr)) {
 866                                 f2fs_invalidate_blocks(sbi, blkaddr);
 867                                 f2fs_update_data_blkaddr(&dn, NEW_ADDR);
 868                         }
 869                         goto unlock_continue;
 870                 }
 871
 872                 f2fs_bug_on(fio.sbi, blkaddr == NULL_ADDR);
 873
 874                 if (fio.encrypted)
 875                         fio.encrypted_page = cc->cpages[i - 1];
 876                 else
 877                         fio.compressed_page = cc->cpages[i - 1];
 878
 879                 cc->cpages[i - 1] = NULL;
 880                 f2fs_outplace_write_data(&dn, &fio);
 881                 (*submitted)++;
 882 unlock_continue:
 883                 inode_dec_dirty_pages(cc->inode);
 884                 unlock_page(fio.page);
 885         }
 886
 887         if (fio.compr_blocks)
 888                 f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
 889         f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
 890
 891         set_inode_flag(cc->inode, FI_APPEND_WRITE);
 892         if (cc->cluster_idx == 0)
 893                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 894
 895         f2fs_put_dnode(&dn);
 896         f2fs_unlock_op(sbi);
 897
 898         down_write(&fi->i_sem);
 899         if (fi->last_disk_size < psize)
 900                 fi->last_disk_size = psize;
 901         up_write(&fi->i_sem);
 902
 903         f2fs_put_rpages(cc);
 904         f2fs_destroy_compress_ctx(cc);
 905         return 0;
 906
 907 out_destroy_crypt:
 908         kfree(cic->rpages);
 909
 910         for (--i; i >= 0; i--)
 911                 fscrypt_finalize_bounce_page(&cc->cpages[i]);
 912         for (i = 0; i < cc->nr_cpages; i++) {
 913                 if (!cc->cpages[i])
 914                         continue;
 915                 f2fs_put_page(cc->cpages[i], 1);
 916         }
 917 out_put_cic:
 918         kfree(cic);
 919 out_put_dnode:
 920         f2fs_put_dnode(&dn);
 921 out_unlock_op:
 922         f2fs_unlock_op(sbi);
 923         return -EAGAIN;
 924 }
 925
 926 void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
 927 {
 928         struct f2fs_sb_info *sbi = bio->bi_private;
 929         struct compress_io_ctx *cic =
 930                         (struct compress_io_ctx *)page_private(page);
 931         int i;
 932
 933         if (unlikely(bio->bi_status))
 934                 mapping_set_error(cic->inode->i_mapping, -EIO);
 935
 936         f2fs_put_compressed_page(page);
 937
 938         dec_page_count(sbi, F2FS_WB_DATA);
 939
 940         if (refcount_dec_not_one(&cic->ref))
 941                 return;
 942
 943         for (i = 0; i < cic->nr_rpages; i++) {
 944                 WARN_ON(!cic->rpages[i]);
 945                 clear_cold_data(cic->rpages[i]);
 946                 end_page_writeback(cic->rpages[i]);
 947         }
 948
 949         kfree(cic->rpages);
 950         kfree(cic);
 951 }
 952
 953 static int f2fs_write_raw_pages(struct compress_ctx *cc,
 954                                         int *submitted,
 955                                         struct writeback_control *wbc,
 956                                         enum iostat_type io_type)
 957 {
 958         struct address_space *mapping = cc->inode->i_mapping;
 959         int _submitted, compr_blocks, ret;
 960         int i = -1, err = 0;
 961
 962         compr_blocks = f2fs_compressed_blocks(cc);
 963         if (compr_blocks < 0) {
 964                 err = compr_blocks;
 965                 goto out_err;
 966         }
 967
 968         for (i = 0; i < cc->cluster_size; i++) {
 969                 if (!cc->rpages[i])
 970                         continue;
 971 retry_write:
 972                 if (cc->rpages[i]->mapping != mapping) {
 973                         unlock_page(cc->rpages[i]);
 974                         continue;
 975                 }
 976
 977                 BUG_ON(!PageLocked(cc->rpages[i]));
 978
 979                 ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted,
 980                                                 NULL, NULL, wbc, io_type,
 981                                                 compr_blocks);
 982                 if (ret) {
 983                         if (ret == AOP_WRITEPAGE_ACTIVATE) {
 984                                 unlock_page(cc->rpages[i]);
 985                                 ret = 0;
 986                         } else if (ret == -EAGAIN) {
 987                                 ret = 0;
 988                                 cond_resched();
 989                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 990                                 lock_page(cc->rpages[i]);
 991                                 clear_page_dirty_for_io(cc->rpages[i]);
 992                                 goto retry_write;
 993                         }
 994                         err = ret;
 995                         goto out_fail;
 996                 }
 997
 998                 *submitted += _submitted;
 999         }
1000         return 0;
1001
1002 out_fail:
1003         /* TODO: revoke partially updated block addresses */
1004         BUG_ON(compr_blocks);
1005 out_err:
1006         for (++i; i < cc->cluster_size; i++) {
1007                 if (!cc->rpages[i])
1008                         continue;
1009                 redirty_page_for_writepage(wbc, cc->rpages[i]);
1010                 unlock_page(cc->rpages[i]);
1011         }
1012         return err;
1013 }
1014
1015 int f2fs_write_multi_pages(struct compress_ctx *cc,
1016                                         int *submitted,
1017                                         struct writeback_control *wbc,
1018                                         enum iostat_type io_type)
1019 {
1020         struct f2fs_inode_info *fi = F2FS_I(cc->inode);
1021         const struct f2fs_compress_ops *cops =
1022                         f2fs_cops[fi->i_compress_algorithm];
1023         int err;
1024
1025         *submitted = 0;
1026         if (cluster_may_compress(cc)) {
1027                 err = f2fs_compress_pages(cc);
1028                 if (err == -EAGAIN) {
1029                         goto write;
1030                 } else if (err) {
1031                         f2fs_put_rpages_wbc(cc, wbc, true, 1);
1032                         goto destroy_out;
1033                 }
1034
1035                 err = f2fs_write_compressed_pages(cc, submitted,
1036                                                         wbc, io_type);
1037                 cops->destroy_compress_ctx(cc);
1038                 if (!err)
1039                         return 0;
1040                 f2fs_bug_on(F2FS_I_SB(cc->inode), err != -EAGAIN);
1041         }
1042 write:
1043         f2fs_bug_on(F2FS_I_SB(cc->inode), *submitted);
1044
1045         err = f2fs_write_raw_pages(cc, submitted, wbc, io_type);
1046         f2fs_put_rpages_wbc(cc, wbc, false, 0);
1047 destroy_out:
1048         f2fs_destroy_compress_ctx(cc);
1049         return err;
1050 }
1051
1052 struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
1053 {
1054         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
1055         struct decompress_io_ctx *dic;
1056         pgoff_t start_idx = start_idx_of_cluster(cc);
1057         int i;
1058
1059         dic = f2fs_kzalloc(sbi, sizeof(struct decompress_io_ctx), GFP_NOFS);
1060         if (!dic)
1061                 return ERR_PTR(-ENOMEM);
1062
1063         dic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
1064                         cc->log_cluster_size, GFP_NOFS);
1065         if (!dic->rpages) {
1066                 kfree(dic);
1067                 return ERR_PTR(-ENOMEM);
1068         }
1069
1070         dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
1071         dic->inode = cc->inode;
1072         refcount_set(&dic->ref, 1);
1073         dic->cluster_idx = cc->cluster_idx;
1074         dic->cluster_size = cc->cluster_size;
1075         dic->log_cluster_size = cc->log_cluster_size;
1076         dic->nr_cpages = cc->nr_cpages;
1077         dic->failed = false;
1078
1079         for (i = 0; i < dic->cluster_size; i++)
1080                 dic->rpages[i] = cc->rpages[i];
1081         dic->nr_rpages = cc->cluster_size;
1082
1083         dic->cpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
1084                                         dic->nr_cpages, GFP_NOFS);
1085         if (!dic->cpages)
1086                 goto out_free;
1087
1088         for (i = 0; i < dic->nr_cpages; i++) {
1089                 struct page *page;
1090
1091                 page = f2fs_grab_page();
1092                 if (!page)
1093                         goto out_free;
1094
1095                 f2fs_set_compressed_page(page, cc->inode,
1096                                         start_idx + i + 1,
1097                                         dic, i ? &dic->ref : NULL);
1098                 dic->cpages[i] = page;
1099         }
1100
1101         dic->tpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
1102                                         dic->cluster_size, GFP_NOFS);
1103         if (!dic->tpages)
1104                 goto out_free;
1105
1106         for (i = 0; i < dic->cluster_size; i++) {
1107                 if (cc->rpages[i])
1108                         continue;
1109
1110                 dic->tpages[i] = f2fs_grab_page();
1111                 if (!dic->tpages[i])
1112                         goto out_free;
1113         }
1114
1115         for (i = 0; i < dic->cluster_size; i++) {
1116                 if (dic->tpages[i])
1117                         continue;
1118                 dic->tpages[i] = cc->rpages[i];
1119         }
1120
1121         return dic;
1122
1123 out_free:
1124         f2fs_free_dic(dic);
1125         return ERR_PTR(-ENOMEM);
1126 }
1127
1128 void f2fs_free_dic(struct decompress_io_ctx *dic)
1129 {
1130         int i;
1131
1132         if (dic->tpages) {
1133                 for (i = 0; i < dic->cluster_size; i++) {
1134                         if (dic->rpages[i])
1135                                 continue;
1136                         f2fs_put_page(dic->tpages[i], 1);
1137                 }
1138                 kfree(dic->tpages);
1139         }
1140
1141         if (dic->cpages) {
1142                 for (i = 0; i < dic->nr_cpages; i++) {
1143                         if (!dic->cpages[i])
1144                                 continue;
1145                         f2fs_put_compressed_page(dic->cpages[i]);
1146                 }
1147                 kfree(dic->cpages);
1148         }
1149
1150         kfree(dic->rpages);
1151         kfree(dic);
1152 }
1153
1154 void f2fs_decompress_end_io(struct page **rpages,
1155                         unsigned int cluster_size, bool err, bool verity)
1156 {
1157         int i;
1158
1159         for (i = 0; i < cluster_size; i++) {
1160                 struct page *rpage = rpages[i];
1161
1162                 if (!rpage)
1163                         continue;
1164
1165                 if (err || PageError(rpage)) {
1166                         ClearPageUptodate(rpage);
1167                         ClearPageError(rpage);
1168                 } else {
1169                         if (!verity || fsverity_verify_page(rpage))
1170                                 SetPageUptodate(rpage);
1171                         else
1172                                 SetPageError(rpage);
1173                 }
1174                 unlock_page(rpage);
1175         }
1176 }