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         nr_cpages = DIV_ROUND_UP(cc->clen + COMPRESS_HEADER_SIZE, PAGE_SIZE);
 389
 390         /* zero out any unused part of the last page */
 391         memset(&cc->cbuf->cdata[cc->clen], 0,
 392                (nr_cpages * PAGE_SIZE) - (cc->clen + COMPRESS_HEADER_SIZE));
 393
 394         vunmap(cc->cbuf);
 395         vunmap(cc->rbuf);
 396
 397         for (i = nr_cpages; i < cc->nr_cpages; i++) {
 398                 f2fs_put_compressed_page(cc->cpages[i]);
 399                 cc->cpages[i] = NULL;
 400         }
 401
 402         cops->destroy_compress_ctx(cc);
 403
 404         cc->nr_cpages = nr_cpages;
 405
 406         trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
 407                                                         cc->clen, ret);
 408         return 0;
 409
 410 out_vunmap_cbuf:
 411         vunmap(cc->cbuf);
 412 out_vunmap_rbuf:
 413         vunmap(cc->rbuf);
 414 out_free_cpages:
 415         for (i = 0; i < cc->nr_cpages; i++) {
 416                 if (cc->cpages[i])
 417                         f2fs_put_compressed_page(cc->cpages[i]);
 418         }
 419         kfree(cc->cpages);
 420         cc->cpages = NULL;
 421 destroy_compress_ctx:
 422         cops->destroy_compress_ctx(cc);
 423 out:
 424         trace_f2fs_compress_pages_end(cc->inode, cc->cluster_idx,
 425                                                         cc->clen, ret);
 426         return ret;
 427 }
 428
 429 void f2fs_decompress_pages(struct bio *bio, struct page *page, bool verity)
 430 {
 431         struct decompress_io_ctx *dic =
 432                         (struct decompress_io_ctx *)page_private(page);
 433         struct f2fs_sb_info *sbi = F2FS_I_SB(dic->inode);
 434         struct f2fs_inode_info *fi= F2FS_I(dic->inode);
 435         const struct f2fs_compress_ops *cops =
 436                         f2fs_cops[fi->i_compress_algorithm];
 437         int ret;
 438
 439         dec_page_count(sbi, F2FS_RD_DATA);
 440
 441         if (bio->bi_status || PageError(page))
 442                 dic->failed = true;
 443
 444         if (refcount_dec_not_one(&dic->ref))
 445                 return;
 446
 447         trace_f2fs_decompress_pages_start(dic->inode, dic->cluster_idx,
 448                                 dic->cluster_size, fi->i_compress_algorithm);
 449
 450         /* submit partial compressed pages */
 451         if (dic->failed) {
 452                 ret = -EIO;
 453                 goto out_free_dic;
 454         }
 455
 456         dic->rbuf = vmap(dic->tpages, dic->cluster_size, VM_MAP, PAGE_KERNEL);
 457         if (!dic->rbuf) {
 458                 ret = -ENOMEM;
 459                 goto out_free_dic;
 460         }
 461
 462         dic->cbuf = vmap(dic->cpages, dic->nr_cpages, VM_MAP, PAGE_KERNEL_RO);
 463         if (!dic->cbuf) {
 464                 ret = -ENOMEM;
 465                 goto out_vunmap_rbuf;
 466         }
 467
 468         dic->clen = le32_to_cpu(dic->cbuf->clen);
 469         dic->rlen = PAGE_SIZE << dic->log_cluster_size;
 470
 471         if (dic->clen > PAGE_SIZE * dic->nr_cpages - COMPRESS_HEADER_SIZE) {
 472                 ret = -EFSCORRUPTED;
 473                 goto out_vunmap_cbuf;
 474         }
 475
 476         ret = cops->decompress_pages(dic);
 477
 478 out_vunmap_cbuf:
 479         vunmap(dic->cbuf);
 480 out_vunmap_rbuf:
 481         vunmap(dic->rbuf);
 482 out_free_dic:
 483         if (verity)
 484                 refcount_add(dic->nr_cpages - 1, &dic->ref);
 485         if (!verity)
 486                 f2fs_decompress_end_io(dic->rpages, dic->cluster_size,
 487                                                                 ret, false);
 488
 489         trace_f2fs_decompress_pages_end(dic->inode, dic->cluster_idx,
 490                                                         dic->clen, ret);
 491         if (!verity)
 492                 f2fs_free_dic(dic);
 493 }
 494
 495 static bool is_page_in_cluster(struct compress_ctx *cc, pgoff_t index)
 496 {
 497         if (cc->cluster_idx == NULL_CLUSTER)
 498                 return true;
 499         return cc->cluster_idx == cluster_idx(cc, index);
 500 }
 501
 502 bool f2fs_cluster_is_empty(struct compress_ctx *cc)
 503 {
 504         return cc->nr_rpages == 0;
 505 }
 506
 507 static bool f2fs_cluster_is_full(struct compress_ctx *cc)
 508 {
 509         return cc->cluster_size == cc->nr_rpages;
 510 }
 511
 512 bool f2fs_cluster_can_merge_page(struct compress_ctx *cc, pgoff_t index)
 513 {
 514         if (f2fs_cluster_is_empty(cc))
 515                 return true;
 516         return is_page_in_cluster(cc, index);
 517 }
 518
 519 static bool __cluster_may_compress(struct compress_ctx *cc)
 520 {
 521         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 522         loff_t i_size = i_size_read(cc->inode);
 523         unsigned nr_pages = DIV_ROUND_UP(i_size, PAGE_SIZE);
 524         int i;
 525
 526         for (i = 0; i < cc->cluster_size; i++) {
 527                 struct page *page = cc->rpages[i];
 528
 529                 f2fs_bug_on(sbi, !page);
 530
 531                 if (unlikely(f2fs_cp_error(sbi)))
 532                         return false;
 533                 if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
 534                         return false;
 535
 536                 /* beyond EOF */
 537                 if (page->index >= nr_pages)
 538                         return false;
 539         }
 540         return true;
 541 }
 542
 543 static int __f2fs_cluster_blocks(struct compress_ctx *cc, bool compr)
 544 {
 545         struct dnode_of_data dn;
 546         int ret;
 547
 548         set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 549         ret = f2fs_get_dnode_of_data(&dn, start_idx_of_cluster(cc),
 550                                                         LOOKUP_NODE);
 551         if (ret) {
 552                 if (ret == -ENOENT)
 553                         ret = 0;
 554                 goto fail;
 555         }
 556
 557         if (dn.data_blkaddr == COMPRESS_ADDR) {
 558                 int i;
 559
 560                 ret = 1;
 561                 for (i = 1; i < cc->cluster_size; i++) {
 562                         block_t blkaddr;
 563
 564                         blkaddr = datablock_addr(dn.inode,
 565                                         dn.node_page, dn.ofs_in_node + i);
 566                         if (compr) {
 567                                 if (__is_valid_data_blkaddr(blkaddr))
 568                                         ret++;
 569                         } else {
 570                                 if (blkaddr != NULL_ADDR)
 571                                         ret++;
 572                         }
 573                 }
 574         }
 575 fail:
 576         f2fs_put_dnode(&dn);
 577         return ret;
 578 }
 579
 580 /* return # of compressed blocks in compressed cluster */
 581 static int f2fs_compressed_blocks(struct compress_ctx *cc)
 582 {
 583         return __f2fs_cluster_blocks(cc, true);
 584 }
 585
 586 /* return # of valid blocks in compressed cluster */
 587 static int f2fs_cluster_blocks(struct compress_ctx *cc, bool compr)
 588 {
 589         return __f2fs_cluster_blocks(cc, false);
 590 }
 591
 592 int f2fs_is_compressed_cluster(struct inode *inode, pgoff_t index)
 593 {
 594         struct compress_ctx cc = {
 595                 .inode = inode,
 596                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 597                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 598                 .cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
 599         };
 600
 601         return f2fs_cluster_blocks(&cc, false);
 602 }
 603
 604 static bool cluster_may_compress(struct compress_ctx *cc)
 605 {
 606         if (!f2fs_compressed_file(cc->inode))
 607                 return false;
 608         if (f2fs_is_atomic_file(cc->inode))
 609                 return false;
 610         if (f2fs_is_mmap_file(cc->inode))
 611                 return false;
 612         if (!f2fs_cluster_is_full(cc))
 613                 return false;
 614         return __cluster_may_compress(cc);
 615 }
 616
 617 static void set_cluster_writeback(struct compress_ctx *cc)
 618 {
 619         int i;
 620
 621         for (i = 0; i < cc->cluster_size; i++) {
 622                 if (cc->rpages[i])
 623                         set_page_writeback(cc->rpages[i]);
 624         }
 625 }
 626
 627 static void set_cluster_dirty(struct compress_ctx *cc)
 628 {
 629         int i;
 630
 631         for (i = 0; i < cc->cluster_size; i++)
 632                 if (cc->rpages[i])
 633                         set_page_dirty(cc->rpages[i]);
 634 }
 635
 636 static int prepare_compress_overwrite(struct compress_ctx *cc,
 637                 struct page **pagep, pgoff_t index, void **fsdata)
 638 {
 639         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
 640         struct address_space *mapping = cc->inode->i_mapping;
 641         struct page *page;
 642         struct dnode_of_data dn;
 643         sector_t last_block_in_bio;
 644         unsigned fgp_flag = FGP_LOCK | FGP_WRITE | FGP_CREAT;
 645         pgoff_t start_idx = start_idx_of_cluster(cc);
 646         int i, ret;
 647         bool prealloc;
 648
 649 retry:
 650         ret = f2fs_cluster_blocks(cc, false);
 651         if (ret <= 0)
 652                 return ret;
 653
 654         /* compressed case */
 655         prealloc = (ret < cc->cluster_size);
 656
 657         ret = f2fs_init_compress_ctx(cc);
 658         if (ret)
 659                 return ret;
 660
 661         /* keep page reference to avoid page reclaim */
 662         for (i = 0; i < cc->cluster_size; i++) {
 663                 page = f2fs_pagecache_get_page(mapping, start_idx + i,
 664                                                         fgp_flag, GFP_NOFS);
 665                 if (!page) {
 666                         ret = -ENOMEM;
 667                         goto unlock_pages;
 668                 }
 669
 670                 if (PageUptodate(page))
 671                         unlock_page(page);
 672                 else
 673                         f2fs_compress_ctx_add_page(cc, page);
 674         }
 675
 676         if (!f2fs_cluster_is_empty(cc)) {
 677                 struct bio *bio = NULL;
 678
 679                 ret = f2fs_read_multi_pages(cc, &bio, cc->cluster_size,
 680                                                 &last_block_in_bio, false);
 681                 f2fs_destroy_compress_ctx(cc);
 682                 if (ret)
 683                         goto release_pages;
 684                 if (bio)
 685                         f2fs_submit_bio(sbi, bio, DATA);
 686
 687                 ret = f2fs_init_compress_ctx(cc);
 688                 if (ret)
 689                         goto release_pages;
 690         }
 691
 692         for (i = 0; i < cc->cluster_size; i++) {
 693                 f2fs_bug_on(sbi, cc->rpages[i]);
 694
 695                 page = find_lock_page(mapping, start_idx + i);
 696                 f2fs_bug_on(sbi, !page);
 697
 698                 f2fs_wait_on_page_writeback(page, DATA, true, true);
 699
 700                 f2fs_compress_ctx_add_page(cc, page);
 701                 f2fs_put_page(page, 0);
 702
 703                 if (!PageUptodate(page)) {
 704                         f2fs_unlock_rpages(cc, i + 1);
 705                         f2fs_put_rpages_mapping(cc, mapping, start_idx,
 706                                         cc->cluster_size);
 707                         f2fs_destroy_compress_ctx(cc);
 708                         goto retry;
 709                 }
 710         }
 711
 712         if (prealloc) {
 713                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, true);
 714
 715                 set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 716
 717                 for (i = cc->cluster_size - 1; i > 0; i--) {
 718                         ret = f2fs_get_block(&dn, start_idx + i);
 719                         if (ret) {
 720                                 i = cc->cluster_size;
 721                                 break;
 722                         }
 723
 724                         if (dn.data_blkaddr != NEW_ADDR)
 725                                 break;
 726                 }
 727
 728                 __do_map_lock(sbi, F2FS_GET_BLOCK_PRE_AIO, false);
 729         }
 730
 731         if (likely(!ret)) {
 732                 *fsdata = cc->rpages;
 733                 *pagep = cc->rpages[offset_in_cluster(cc, index)];
 734                 return cc->cluster_size;
 735         }
 736
 737 unlock_pages:
 738         f2fs_unlock_rpages(cc, i);
 739 release_pages:
 740         f2fs_put_rpages_mapping(cc, mapping, start_idx, i);
 741         f2fs_destroy_compress_ctx(cc);
 742         return ret;
 743 }
 744
 745 int f2fs_prepare_compress_overwrite(struct inode *inode,
 746                 struct page **pagep, pgoff_t index, void **fsdata)
 747 {
 748         struct compress_ctx cc = {
 749                 .inode = inode,
 750                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 751                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 752                 .cluster_idx = index >> F2FS_I(inode)->i_log_cluster_size,
 753                 .rpages = NULL,
 754                 .nr_rpages = 0,
 755         };
 756
 757         return prepare_compress_overwrite(&cc, pagep, index, fsdata);
 758 }
 759
 760 bool f2fs_compress_write_end(struct inode *inode, void *fsdata,
 761                                         pgoff_t index, unsigned copied)
 762
 763 {
 764         struct compress_ctx cc = {
 765                 .log_cluster_size = F2FS_I(inode)->i_log_cluster_size,
 766                 .cluster_size = F2FS_I(inode)->i_cluster_size,
 767                 .rpages = fsdata,
 768         };
 769         bool first_index = (index == cc.rpages[0]->index);
 770
 771         if (copied)
 772                 set_cluster_dirty(&cc);
 773
 774         f2fs_put_rpages_wbc(&cc, NULL, false, 1);
 775         f2fs_destroy_compress_ctx(&cc);
 776
 777         return first_index;
 778 }
 779
 780 static int f2fs_write_compressed_pages(struct compress_ctx *cc,
 781                                         int *submitted,
 782                                         struct writeback_control *wbc,
 783                                         enum iostat_type io_type)
 784 {
 785         struct inode *inode = cc->inode;
 786         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 787         struct f2fs_inode_info *fi = F2FS_I(inode);
 788         struct f2fs_io_info fio = {
 789                 .sbi = sbi,
 790                 .ino = cc->inode->i_ino,
 791                 .type = DATA,
 792                 .op = REQ_OP_WRITE,
 793                 .op_flags = wbc_to_write_flags(wbc),
 794                 .old_blkaddr = NEW_ADDR,
 795                 .page = NULL,
 796                 .encrypted_page = NULL,
 797                 .compressed_page = NULL,
 798                 .submitted = false,
 799                 .io_type = io_type,
 800                 .io_wbc = wbc,
 801                 .encrypted = f2fs_encrypted_file(cc->inode),
 802         };
 803         struct dnode_of_data dn;
 804         struct node_info ni;
 805         struct compress_io_ctx *cic;
 806         pgoff_t start_idx = start_idx_of_cluster(cc);
 807         unsigned int last_index = cc->cluster_size - 1;
 808         loff_t psize;
 809         int i, err;
 810
 811         if (!f2fs_trylock_op(sbi))
 812                 return -EAGAIN;
 813
 814         set_new_dnode(&dn, cc->inode, NULL, NULL, 0);
 815
 816         err = f2fs_get_dnode_of_data(&dn, start_idx, LOOKUP_NODE);
 817         if (err)
 818                 goto out_unlock_op;
 819
 820         for (i = 0; i < cc->cluster_size; i++) {
 821                 if (datablock_addr(dn.inode, dn.node_page,
 822                                         dn.ofs_in_node + i) == NULL_ADDR)
 823                         goto out_put_dnode;
 824         }
 825
 826         psize = (loff_t)(cc->rpages[last_index]->index + 1) << PAGE_SHIFT;
 827
 828         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 829         if (err)
 830                 goto out_put_dnode;
 831
 832         fio.version = ni.version;
 833
 834         cic = f2fs_kzalloc(sbi, sizeof(struct compress_io_ctx), GFP_NOFS);
 835         if (!cic)
 836                 goto out_put_dnode;
 837
 838         cic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
 839         cic->inode = inode;
 840         refcount_set(&cic->ref, 1);
 841         cic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
 842                         cc->log_cluster_size, GFP_NOFS);
 843         if (!cic->rpages)
 844                 goto out_put_cic;
 845
 846         cic->nr_rpages = cc->cluster_size;
 847
 848         for (i = 0; i < cc->nr_cpages; i++) {
 849                 f2fs_set_compressed_page(cc->cpages[i], inode,
 850                                         cc->rpages[i + 1]->index,
 851                                         cic, i ? &cic->ref : NULL);
 852                 fio.compressed_page = cc->cpages[i];
 853                 if (fio.encrypted) {
 854                         fio.page = cc->rpages[i + 1];
 855                         err = f2fs_encrypt_one_page(&fio);
 856                         if (err)
 857                                 goto out_destroy_crypt;
 858                         cc->cpages[i] = fio.encrypted_page;
 859                 }
 860         }
 861
 862         set_cluster_writeback(cc);
 863
 864         for (i = 0; i < cc->cluster_size; i++)
 865                 cic->rpages[i] = cc->rpages[i];
 866
 867         for (i = 0; i < cc->cluster_size; i++, dn.ofs_in_node++) {
 868                 block_t blkaddr;
 869
 870                 blkaddr = datablock_addr(dn.inode, dn.node_page,
 871                                                         dn.ofs_in_node);
 872                 fio.page = cc->rpages[i];
 873                 fio.old_blkaddr = blkaddr;
 874
 875                 /* cluster header */
 876                 if (i == 0) {
 877                         if (blkaddr == COMPRESS_ADDR)
 878                                 fio.compr_blocks++;
 879                         if (__is_valid_data_blkaddr(blkaddr))
 880                                 f2fs_invalidate_blocks(sbi, blkaddr);
 881                         f2fs_update_data_blkaddr(&dn, COMPRESS_ADDR);
 882                         goto unlock_continue;
 883                 }
 884
 885                 if (fio.compr_blocks && __is_valid_data_blkaddr(blkaddr))
 886                         fio.compr_blocks++;
 887
 888                 if (i > cc->nr_cpages) {
 889                         if (__is_valid_data_blkaddr(blkaddr)) {
 890                                 f2fs_invalidate_blocks(sbi, blkaddr);
 891                                 f2fs_update_data_blkaddr(&dn, NEW_ADDR);
 892                         }
 893                         goto unlock_continue;
 894                 }
 895
 896                 f2fs_bug_on(fio.sbi, blkaddr == NULL_ADDR);
 897
 898                 if (fio.encrypted)
 899                         fio.encrypted_page = cc->cpages[i - 1];
 900                 else
 901                         fio.compressed_page = cc->cpages[i - 1];
 902
 903                 cc->cpages[i - 1] = NULL;
 904                 f2fs_outplace_write_data(&dn, &fio);
 905                 (*submitted)++;
 906 unlock_continue:
 907                 inode_dec_dirty_pages(cc->inode);
 908                 unlock_page(fio.page);
 909         }
 910
 911         if (fio.compr_blocks)
 912                 f2fs_i_compr_blocks_update(inode, fio.compr_blocks - 1, false);
 913         f2fs_i_compr_blocks_update(inode, cc->nr_cpages, true);
 914
 915         set_inode_flag(cc->inode, FI_APPEND_WRITE);
 916         if (cc->cluster_idx == 0)
 917                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 918
 919         f2fs_put_dnode(&dn);
 920         f2fs_unlock_op(sbi);
 921
 922         down_write(&fi->i_sem);
 923         if (fi->last_disk_size < psize)
 924                 fi->last_disk_size = psize;
 925         up_write(&fi->i_sem);
 926
 927         f2fs_put_rpages(cc);
 928         f2fs_destroy_compress_ctx(cc);
 929         return 0;
 930
 931 out_destroy_crypt:
 932         kfree(cic->rpages);
 933
 934         for (--i; i >= 0; i--)
 935                 fscrypt_finalize_bounce_page(&cc->cpages[i]);
 936         for (i = 0; i < cc->nr_cpages; i++) {
 937                 if (!cc->cpages[i])
 938                         continue;
 939                 f2fs_put_page(cc->cpages[i], 1);
 940         }
 941 out_put_cic:
 942         kfree(cic);
 943 out_put_dnode:
 944         f2fs_put_dnode(&dn);
 945 out_unlock_op:
 946         f2fs_unlock_op(sbi);
 947         return -EAGAIN;
 948 }
 949
 950 void f2fs_compress_write_end_io(struct bio *bio, struct page *page)
 951 {
 952         struct f2fs_sb_info *sbi = bio->bi_private;
 953         struct compress_io_ctx *cic =
 954                         (struct compress_io_ctx *)page_private(page);
 955         int i;
 956
 957         if (unlikely(bio->bi_status))
 958                 mapping_set_error(cic->inode->i_mapping, -EIO);
 959
 960         f2fs_put_compressed_page(page);
 961
 962         dec_page_count(sbi, F2FS_WB_DATA);
 963
 964         if (refcount_dec_not_one(&cic->ref))
 965                 return;
 966
 967         for (i = 0; i < cic->nr_rpages; i++) {
 968                 WARN_ON(!cic->rpages[i]);
 969                 clear_cold_data(cic->rpages[i]);
 970                 end_page_writeback(cic->rpages[i]);
 971         }
 972
 973         kfree(cic->rpages);
 974         kfree(cic);
 975 }
 976
 977 static int f2fs_write_raw_pages(struct compress_ctx *cc,
 978                                         int *submitted,
 979                                         struct writeback_control *wbc,
 980                                         enum iostat_type io_type)
 981 {
 982         struct address_space *mapping = cc->inode->i_mapping;
 983         int _submitted, compr_blocks, ret;
 984         int i = -1, err = 0;
 985
 986         compr_blocks = f2fs_compressed_blocks(cc);
 987         if (compr_blocks < 0) {
 988                 err = compr_blocks;
 989                 goto out_err;
 990         }
 991
 992         for (i = 0; i < cc->cluster_size; i++) {
 993                 if (!cc->rpages[i])
 994                         continue;
 995 retry_write:
 996                 if (cc->rpages[i]->mapping != mapping) {
 997                         unlock_page(cc->rpages[i]);
 998                         continue;
 999                 }
1000
1001                 BUG_ON(!PageLocked(cc->rpages[i]));
1002
1003                 ret = f2fs_write_single_data_page(cc->rpages[i], &_submitted,
1004                                                 NULL, NULL, wbc, io_type,
1005                                                 compr_blocks);
1006                 if (ret) {
1007                         if (ret == AOP_WRITEPAGE_ACTIVATE) {
1008                                 unlock_page(cc->rpages[i]);
1009                                 ret = 0;
1010                         } else if (ret == -EAGAIN) {
1011                                 /*
1012                                  * for quota file, just redirty left pages to
1013                                  * avoid deadlock caused by cluster update race
1014                                  * from foreground operation.
1015                                  */
1016                                 if (IS_NOQUOTA(cc->inode)) {
1017                                         err = 0;
1018                                         goto out_err;
1019                                 }
1020                                 ret = 0;
1021                                 cond_resched();
1022                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
1023                                 lock_page(cc->rpages[i]);
1024                                 clear_page_dirty_for_io(cc->rpages[i]);
1025                                 goto retry_write;
1026                         }
1027                         err = ret;
1028                         goto out_err;
1029                 }
1030
1031                 *submitted += _submitted;
1032         }
1033         return 0;
1034 out_err:
1035         for (++i; i < cc->cluster_size; i++) {
1036                 if (!cc->rpages[i])
1037                         continue;
1038                 redirty_page_for_writepage(wbc, cc->rpages[i]);
1039                 unlock_page(cc->rpages[i]);
1040         }
1041         return err;
1042 }
1043
1044 int f2fs_write_multi_pages(struct compress_ctx *cc,
1045                                         int *submitted,
1046                                         struct writeback_control *wbc,
1047                                         enum iostat_type io_type)
1048 {
1049         struct f2fs_inode_info *fi = F2FS_I(cc->inode);
1050         const struct f2fs_compress_ops *cops =
1051                         f2fs_cops[fi->i_compress_algorithm];
1052         int err;
1053
1054         *submitted = 0;
1055         if (cluster_may_compress(cc)) {
1056                 err = f2fs_compress_pages(cc);
1057                 if (err == -EAGAIN) {
1058                         goto write;
1059                 } else if (err) {
1060                         f2fs_put_rpages_wbc(cc, wbc, true, 1);
1061                         goto destroy_out;
1062                 }
1063
1064                 err = f2fs_write_compressed_pages(cc, submitted,
1065                                                         wbc, io_type);
1066                 cops->destroy_compress_ctx(cc);
1067                 if (!err)
1068                         return 0;
1069                 f2fs_bug_on(F2FS_I_SB(cc->inode), err != -EAGAIN);
1070         }
1071 write:
1072         f2fs_bug_on(F2FS_I_SB(cc->inode), *submitted);
1073
1074         err = f2fs_write_raw_pages(cc, submitted, wbc, io_type);
1075         f2fs_put_rpages_wbc(cc, wbc, false, 0);
1076 destroy_out:
1077         f2fs_destroy_compress_ctx(cc);
1078         return err;
1079 }
1080
1081 struct decompress_io_ctx *f2fs_alloc_dic(struct compress_ctx *cc)
1082 {
1083         struct f2fs_sb_info *sbi = F2FS_I_SB(cc->inode);
1084         struct decompress_io_ctx *dic;
1085         pgoff_t start_idx = start_idx_of_cluster(cc);
1086         int i;
1087
1088         dic = f2fs_kzalloc(sbi, sizeof(struct decompress_io_ctx), GFP_NOFS);
1089         if (!dic)
1090                 return ERR_PTR(-ENOMEM);
1091
1092         dic->rpages = f2fs_kzalloc(sbi, sizeof(struct page *) <<
1093                         cc->log_cluster_size, GFP_NOFS);
1094         if (!dic->rpages) {
1095                 kfree(dic);
1096                 return ERR_PTR(-ENOMEM);
1097         }
1098
1099         dic->magic = F2FS_COMPRESSED_PAGE_MAGIC;
1100         dic->inode = cc->inode;
1101         refcount_set(&dic->ref, 1);
1102         dic->cluster_idx = cc->cluster_idx;
1103         dic->cluster_size = cc->cluster_size;
1104         dic->log_cluster_size = cc->log_cluster_size;
1105         dic->nr_cpages = cc->nr_cpages;
1106         dic->failed = false;
1107
1108         for (i = 0; i < dic->cluster_size; i++)
1109                 dic->rpages[i] = cc->rpages[i];
1110         dic->nr_rpages = cc->cluster_size;
1111
1112         dic->cpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
1113                                         dic->nr_cpages, GFP_NOFS);
1114         if (!dic->cpages)
1115                 goto out_free;
1116
1117         for (i = 0; i < dic->nr_cpages; i++) {
1118                 struct page *page;
1119
1120                 page = f2fs_grab_page();
1121                 if (!page)
1122                         goto out_free;
1123
1124                 f2fs_set_compressed_page(page, cc->inode,
1125                                         start_idx + i + 1,
1126                                         dic, i ? &dic->ref : NULL);
1127                 dic->cpages[i] = page;
1128         }
1129
1130         dic->tpages = f2fs_kzalloc(sbi, sizeof(struct page *) *
1131                                         dic->cluster_size, GFP_NOFS);
1132         if (!dic->tpages)
1133                 goto out_free;
1134
1135         for (i = 0; i < dic->cluster_size; i++) {
1136                 if (cc->rpages[i])
1137                         continue;
1138
1139                 dic->tpages[i] = f2fs_grab_page();
1140                 if (!dic->tpages[i])
1141                         goto out_free;
1142         }
1143
1144         for (i = 0; i < dic->cluster_size; i++) {
1145                 if (dic->tpages[i])
1146                         continue;
1147                 dic->tpages[i] = cc->rpages[i];
1148         }
1149
1150         return dic;
1151
1152 out_free:
1153         f2fs_free_dic(dic);
1154         return ERR_PTR(-ENOMEM);
1155 }
1156
1157 void f2fs_free_dic(struct decompress_io_ctx *dic)
1158 {
1159         int i;
1160
1161         if (dic->tpages) {
1162                 for (i = 0; i < dic->cluster_size; i++) {
1163                         if (dic->rpages[i])
1164                                 continue;
1165                         f2fs_put_page(dic->tpages[i], 1);
1166                 }
1167                 kfree(dic->tpages);
1168         }
1169
1170         if (dic->cpages) {
1171                 for (i = 0; i < dic->nr_cpages; i++) {
1172                         if (!dic->cpages[i])
1173                                 continue;
1174                         f2fs_put_compressed_page(dic->cpages[i]);
1175                 }
1176                 kfree(dic->cpages);
1177         }
1178
1179         kfree(dic->rpages);
1180         kfree(dic);
1181 }
1182
1183 void f2fs_decompress_end_io(struct page **rpages,
1184                         unsigned int cluster_size, bool err, bool verity)
1185 {
1186         int i;
1187
1188         for (i = 0; i < cluster_size; i++) {
1189                 struct page *rpage = rpages[i];
1190
1191                 if (!rpage)
1192                         continue;
1193
1194                 if (err || PageError(rpage)) {
1195                         ClearPageUptodate(rpage);
1196                         ClearPageError(rpage);
1197                 } else {
1198                         if (!verity || fsverity_verify_page(rpage))
1199                                 SetPageUptodate(rpage);
1200                         else
1201                                 SetPageError(rpage);
1202                 }
1203                 unlock_page(rpage);
1204         }
1205 }