fs/f2fs/gc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * fs/f2fs/gc.c
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/f2fs_fs.h>
  12 #include <linux/kthread.h>
  13 #include <linux/delay.h>
  14 #include <linux/freezer.h>
  15 #include <linux/sched/signal.h>
  16 #include <linux/random.h>
  17 #include <linux/sched/mm.h>
  18
  19 #include "f2fs.h"
  20 #include "node.h"
  21 #include "segment.h"
  22 #include "gc.h"
  23 #include "iostat.h"
  24 #include <trace/events/f2fs.h>
  25
  26 static struct kmem_cache *victim_entry_slab;
  27
  28 static unsigned int count_bits(const unsigned long *addr,
  29                                 unsigned int offset, unsigned int len);
  30
  31 static int gc_thread_func(void *data)
  32 {
  33         struct f2fs_sb_info *sbi = data;
  34         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  35         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  36         wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
  37         unsigned int wait_ms;
  38         struct f2fs_gc_control gc_control = {
  39                 .victim_segno = NULL_SEGNO,
  40                 .should_migrate_blocks = false,
  41                 .err_gc_skipped = false };
  42
  43         wait_ms = gc_th->min_sleep_time;
  44
  45         set_freezable();
  46         do {
  47                 bool sync_mode, foreground = false;
  48
  49                 wait_event_freezable_timeout(*wq,
  50                                 kthread_should_stop() ||
  51                                 waitqueue_active(fggc_wq) ||
  52                                 gc_th->gc_wake,
  53                                 msecs_to_jiffies(wait_ms));
  54
  55                 if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
  56                         foreground = true;
  57
  58                 /* give it a try one time */
  59                 if (gc_th->gc_wake)
  60                         gc_th->gc_wake = false;
  61
  62                 if (f2fs_readonly(sbi->sb)) {
  63                         stat_other_skip_bggc_count(sbi);
  64                         continue;
  65                 }
  66                 if (kthread_should_stop())
  67                         break;
  68
  69                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  70                         increase_sleep_time(gc_th, &wait_ms);
  71                         stat_other_skip_bggc_count(sbi);
  72                         continue;
  73                 }
  74
  75                 if (time_to_inject(sbi, FAULT_CHECKPOINT))
  76                         f2fs_stop_checkpoint(sbi, false,
  77                                         STOP_CP_REASON_FAULT_INJECT);
  78
  79                 if (!sb_start_write_trylock(sbi->sb)) {
  80                         stat_other_skip_bggc_count(sbi);
  81                         continue;
  82                 }
  83
  84                 gc_control.one_time = false;
  85
  86                 /*
  87                  * [GC triggering condition]
  88                  * 0. GC is not conducted currently.
  89                  * 1. There are enough dirty segments.
  90                  * 2. IO subsystem is idle by checking the # of writeback pages.
  91                  * 3. IO subsystem is idle by checking the # of requests in
  92                  *    bdev's request list.
  93                  *
  94                  * Note) We have to avoid triggering GCs frequently.
  95                  * Because it is possible that some segments can be
  96                  * invalidated soon after by user update or deletion.
  97                  * So, I'd like to wait some time to collect dirty segments.
  98                  */
  99                 if (sbi->gc_mode == GC_URGENT_HIGH ||
 100                                 sbi->gc_mode == GC_URGENT_MID) {
 101                         wait_ms = gc_th->urgent_sleep_time;
 102                         f2fs_down_write(&sbi->gc_lock);
 103                         goto do_gc;
 104                 }
 105
 106                 if (foreground) {
 107                         f2fs_down_write(&sbi->gc_lock);
 108                         goto do_gc;
 109                 } else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
 110                         stat_other_skip_bggc_count(sbi);
 111                         goto next;
 112                 }
 113
 114                 if (!is_idle(sbi, GC_TIME)) {
 115                         increase_sleep_time(gc_th, &wait_ms);
 116                         f2fs_up_write(&sbi->gc_lock);
 117                         stat_io_skip_bggc_count(sbi);
 118                         goto next;
 119                 }
 120
 121                 if (f2fs_sb_has_blkzoned(sbi)) {
 122                         if (has_enough_free_blocks(sbi,
 123                                 gc_th->no_zoned_gc_percent)) {
 124                                 wait_ms = gc_th->no_gc_sleep_time;
 125                                 f2fs_up_write(&sbi->gc_lock);
 126                                 goto next;
 127                         }
 128                         if (wait_ms == gc_th->no_gc_sleep_time)
 129                                 wait_ms = gc_th->max_sleep_time;
 130                 }
 131
 132                 if (need_to_boost_gc(sbi)) {
 133                         decrease_sleep_time(gc_th, &wait_ms);
 134                         if (f2fs_sb_has_blkzoned(sbi))
 135                                 gc_control.one_time = true;
 136                 } else {
 137                         increase_sleep_time(gc_th, &wait_ms);
 138                 }
 139 do_gc:
 140                 stat_inc_gc_call_count(sbi, foreground ?
 141                                         FOREGROUND : BACKGROUND);
 142
 143                 sync_mode = (F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC) ||
 144                                 gc_control.one_time;
 145
 146                 /* foreground GC was been triggered via f2fs_balance_fs() */
 147                 if (foreground)
 148                         sync_mode = false;
 149
 150                 gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
 151                 gc_control.no_bg_gc = foreground;
 152                 gc_control.nr_free_secs = foreground ? 1 : 0;
 153
 154                 /* if return value is not zero, no victim was selected */
 155                 if (f2fs_gc(sbi, &gc_control)) {
 156                         /* don't bother wait_ms by foreground gc */
 157                         if (!foreground)
 158                                 wait_ms = gc_th->no_gc_sleep_time;
 159                 } else {
 160                         /* reset wait_ms to default sleep time */
 161                         if (wait_ms == gc_th->no_gc_sleep_time)
 162                                 wait_ms = gc_th->min_sleep_time;
 163                 }
 164
 165                 if (foreground)
 166                         wake_up_all(&gc_th->fggc_wq);
 167
 168                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 169                                 prefree_segments(sbi), free_segments(sbi));
 170
 171                 /* balancing f2fs's metadata periodically */
 172                 f2fs_balance_fs_bg(sbi, true);
 173 next:
 174                 if (sbi->gc_mode != GC_NORMAL) {
 175                         spin_lock(&sbi->gc_remaining_trials_lock);
 176                         if (sbi->gc_remaining_trials) {
 177                                 sbi->gc_remaining_trials--;
 178                                 if (!sbi->gc_remaining_trials)
 179                                         sbi->gc_mode = GC_NORMAL;
 180                         }
 181                         spin_unlock(&sbi->gc_remaining_trials_lock);
 182                 }
 183                 sb_end_write(sbi->sb);
 184
 185         } while (!kthread_should_stop());
 186         return 0;
 187 }
 188
 189 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 190 {
 191         struct f2fs_gc_kthread *gc_th;
 192         dev_t dev = sbi->sb->s_bdev->bd_dev;
 193
 194         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 195         if (!gc_th)
 196                 return -ENOMEM;
 197
 198         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 199         gc_th->valid_thresh_ratio = DEF_GC_THREAD_VALID_THRESH_RATIO;
 200
 201         if (f2fs_sb_has_blkzoned(sbi)) {
 202                 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME_ZONED;
 203                 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME_ZONED;
 204                 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME_ZONED;
 205                 gc_th->no_zoned_gc_percent = LIMIT_NO_ZONED_GC;
 206                 gc_th->boost_zoned_gc_percent = LIMIT_BOOST_ZONED_GC;
 207         } else {
 208                 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 209                 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 210                 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 211                 gc_th->no_zoned_gc_percent = 0;
 212                 gc_th->boost_zoned_gc_percent = 0;
 213         }
 214
 215         gc_th->gc_wake = false;
 216
 217         sbi->gc_thread = gc_th;
 218         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 219         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 220         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 221                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 222         if (IS_ERR(gc_th->f2fs_gc_task)) {
 223                 int err = PTR_ERR(gc_th->f2fs_gc_task);
 224
 225                 kfree(gc_th);
 226                 sbi->gc_thread = NULL;
 227                 return err;
 228         }
 229
 230         return 0;
 231 }
 232
 233 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 234 {
 235         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 236
 237         if (!gc_th)
 238                 return;
 239         kthread_stop(gc_th->f2fs_gc_task);
 240         wake_up_all(&gc_th->fggc_wq);
 241         kfree(gc_th);
 242         sbi->gc_thread = NULL;
 243 }
 244
 245 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 246 {
 247         int gc_mode;
 248
 249         if (gc_type == BG_GC) {
 250                 if (sbi->am.atgc_enabled)
 251                         gc_mode = GC_AT;
 252                 else
 253                         gc_mode = GC_CB;
 254         } else {
 255                 gc_mode = GC_GREEDY;
 256         }
 257
 258         switch (sbi->gc_mode) {
 259         case GC_IDLE_CB:
 260         case GC_URGENT_LOW:
 261         case GC_URGENT_MID:
 262                 gc_mode = GC_CB;
 263                 break;
 264         case GC_IDLE_GREEDY:
 265         case GC_URGENT_HIGH:
 266                 gc_mode = GC_GREEDY;
 267                 break;
 268         case GC_IDLE_AT:
 269                 gc_mode = GC_AT;
 270                 break;
 271         }
 272
 273         return gc_mode;
 274 }
 275
 276 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 277                         int type, struct victim_sel_policy *p)
 278 {
 279         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 280
 281         if (p->alloc_mode == SSR) {
 282                 p->gc_mode = GC_GREEDY;
 283                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 284                 p->max_search = dirty_i->nr_dirty[type];
 285                 p->ofs_unit = 1;
 286         } else if (p->alloc_mode == AT_SSR) {
 287                 p->gc_mode = GC_GREEDY;
 288                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 289                 p->max_search = dirty_i->nr_dirty[type];
 290                 p->ofs_unit = 1;
 291         } else {
 292                 p->gc_mode = select_gc_type(sbi, gc_type);
 293                 p->ofs_unit = SEGS_PER_SEC(sbi);
 294                 if (__is_large_section(sbi)) {
 295                         p->dirty_bitmap = dirty_i->dirty_secmap;
 296                         p->max_search = count_bits(p->dirty_bitmap,
 297                                                 0, MAIN_SECS(sbi));
 298                 } else {
 299                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 300                         p->max_search = dirty_i->nr_dirty[DIRTY];
 301                 }
 302         }
 303
 304         /*
 305          * adjust candidates range, should select all dirty segments for
 306          * foreground GC and urgent GC cases.
 307          */
 308         if (gc_type != FG_GC &&
 309                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 310                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 311                         p->max_search > sbi->max_victim_search)
 312                 p->max_search = sbi->max_victim_search;
 313
 314         /* let's select beginning hot/small space first. */
 315         if (f2fs_need_rand_seg(sbi))
 316                 p->offset = get_random_u32_below(MAIN_SECS(sbi) *
 317                                                 SEGS_PER_SEC(sbi));
 318         else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
 319                 p->offset = 0;
 320         else
 321                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 322 }
 323
 324 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 325                                 struct victim_sel_policy *p)
 326 {
 327         /* SSR allocates in a segment unit */
 328         if (p->alloc_mode == SSR)
 329                 return BLKS_PER_SEG(sbi);
 330         else if (p->alloc_mode == AT_SSR)
 331                 return UINT_MAX;
 332
 333         /* LFS */
 334         if (p->gc_mode == GC_GREEDY)
 335                 return SEGS_TO_BLKS(sbi, 2 * p->ofs_unit);
 336         else if (p->gc_mode == GC_CB)
 337                 return UINT_MAX;
 338         else if (p->gc_mode == GC_AT)
 339                 return UINT_MAX;
 340         else /* No other gc_mode */
 341                 return 0;
 342 }
 343
 344 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 345 {
 346         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 347         unsigned int secno;
 348
 349         /*
 350          * If the gc_type is FG_GC, we can select victim segments
 351          * selected by background GC before.
 352          * Those segments guarantee they have small valid blocks.
 353          */
 354         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 355                 if (sec_usage_check(sbi, secno))
 356                         continue;
 357                 clear_bit(secno, dirty_i->victim_secmap);
 358                 return GET_SEG_FROM_SEC(sbi, secno);
 359         }
 360         return NULL_SEGNO;
 361 }
 362
 363 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 364 {
 365         struct sit_info *sit_i = SIT_I(sbi);
 366         unsigned long long mtime = 0;
 367         unsigned int vblocks;
 368         unsigned char age = 0;
 369         unsigned char u;
 370         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi);
 371
 372         mtime = f2fs_get_section_mtime(sbi, segno);
 373         f2fs_bug_on(sbi, mtime == INVALID_MTIME);
 374         vblocks = get_valid_blocks(sbi, segno, true);
 375         vblocks = div_u64(vblocks, usable_segs_per_sec);
 376
 377         u = BLKS_TO_SEGS(sbi, vblocks * 100);
 378
 379         /* Handle if the system time has changed by the user */
 380         if (mtime < sit_i->min_mtime)
 381                 sit_i->min_mtime = mtime;
 382         if (mtime > sit_i->max_mtime)
 383                 sit_i->max_mtime = mtime;
 384         if (sit_i->max_mtime != sit_i->min_mtime)
 385                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 386                                 sit_i->max_mtime - sit_i->min_mtime);
 387
 388         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 389 }
 390
 391 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 392                         unsigned int segno, struct victim_sel_policy *p)
 393 {
 394         if (p->alloc_mode == SSR)
 395                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 396
 397         if (p->one_time_gc && (get_valid_blocks(sbi, segno, true) >=
 398                 CAP_BLKS_PER_SEC(sbi) * sbi->gc_thread->valid_thresh_ratio /
 399                 100))
 400                 return UINT_MAX;
 401
 402         /* alloc_mode == LFS */
 403         if (p->gc_mode == GC_GREEDY)
 404                 return get_valid_blocks(sbi, segno, true);
 405         else if (p->gc_mode == GC_CB)
 406                 return get_cb_cost(sbi, segno);
 407
 408         f2fs_bug_on(sbi, 1);
 409         return 0;
 410 }
 411
 412 static unsigned int count_bits(const unsigned long *addr,
 413                                 unsigned int offset, unsigned int len)
 414 {
 415         unsigned int end = offset + len, sum = 0;
 416
 417         while (offset < end) {
 418                 if (test_bit(offset++, addr))
 419                         ++sum;
 420         }
 421         return sum;
 422 }
 423
 424 static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
 425                                 struct rb_root_cached *root)
 426 {
 427 #ifdef CONFIG_F2FS_CHECK_FS
 428         struct rb_node *cur = rb_first_cached(root), *next;
 429         struct victim_entry *cur_ve, *next_ve;
 430
 431         while (cur) {
 432                 next = rb_next(cur);
 433                 if (!next)
 434                         return true;
 435
 436                 cur_ve = rb_entry(cur, struct victim_entry, rb_node);
 437                 next_ve = rb_entry(next, struct victim_entry, rb_node);
 438
 439                 if (cur_ve->mtime > next_ve->mtime) {
 440                         f2fs_info(sbi, "broken victim_rbtree, "
 441                                 "cur_mtime(%llu) next_mtime(%llu)",
 442                                 cur_ve->mtime, next_ve->mtime);
 443                         return false;
 444                 }
 445                 cur = next;
 446         }
 447 #endif
 448         return true;
 449 }
 450
 451 static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
 452                                         unsigned long long mtime)
 453 {
 454         struct atgc_management *am = &sbi->am;
 455         struct rb_node *node = am->root.rb_root.rb_node;
 456         struct victim_entry *ve = NULL;
 457
 458         while (node) {
 459                 ve = rb_entry(node, struct victim_entry, rb_node);
 460
 461                 if (mtime < ve->mtime)
 462                         node = node->rb_left;
 463                 else
 464                         node = node->rb_right;
 465         }
 466         return ve;
 467 }
 468
 469 static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
 470                 unsigned long long mtime, unsigned int segno)
 471 {
 472         struct atgc_management *am = &sbi->am;
 473         struct victim_entry *ve;
 474
 475         ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS, true, NULL);
 476
 477         ve->mtime = mtime;
 478         ve->segno = segno;
 479
 480         list_add_tail(&ve->list, &am->victim_list);
 481         am->victim_count++;
 482
 483         return ve;
 484 }
 485
 486 static void __insert_victim_entry(struct f2fs_sb_info *sbi,
 487                                 unsigned long long mtime, unsigned int segno)
 488 {
 489         struct atgc_management *am = &sbi->am;
 490         struct rb_root_cached *root = &am->root;
 491         struct rb_node **p = &root->rb_root.rb_node;
 492         struct rb_node *parent = NULL;
 493         struct victim_entry *ve;
 494         bool left_most = true;
 495
 496         /* look up rb tree to find parent node */
 497         while (*p) {
 498                 parent = *p;
 499                 ve = rb_entry(parent, struct victim_entry, rb_node);
 500
 501                 if (mtime < ve->mtime) {
 502                         p = &(*p)->rb_left;
 503                 } else {
 504                         p = &(*p)->rb_right;
 505                         left_most = false;
 506                 }
 507         }
 508
 509         ve = __create_victim_entry(sbi, mtime, segno);
 510
 511         rb_link_node(&ve->rb_node, parent, p);
 512         rb_insert_color_cached(&ve->rb_node, root, left_most);
 513 }
 514
 515 static void add_victim_entry(struct f2fs_sb_info *sbi,
 516                                 struct victim_sel_policy *p, unsigned int segno)
 517 {
 518         struct sit_info *sit_i = SIT_I(sbi);
 519         unsigned long long mtime = 0;
 520
 521         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 522                 if (p->gc_mode == GC_AT &&
 523                         get_valid_blocks(sbi, segno, true) == 0)
 524                         return;
 525         }
 526
 527         mtime = f2fs_get_section_mtime(sbi, segno);
 528         f2fs_bug_on(sbi, mtime == INVALID_MTIME);
 529
 530         /* Handle if the system time has changed by the user */
 531         if (mtime < sit_i->min_mtime)
 532                 sit_i->min_mtime = mtime;
 533         if (mtime > sit_i->max_mtime)
 534                 sit_i->max_mtime = mtime;
 535         if (mtime < sit_i->dirty_min_mtime)
 536                 sit_i->dirty_min_mtime = mtime;
 537         if (mtime > sit_i->dirty_max_mtime)
 538                 sit_i->dirty_max_mtime = mtime;
 539
 540         /* don't choose young section as candidate */
 541         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 542                 return;
 543
 544         __insert_victim_entry(sbi, mtime, segno);
 545 }
 546
 547 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 548                                                 struct victim_sel_policy *p)
 549 {
 550         struct sit_info *sit_i = SIT_I(sbi);
 551         struct atgc_management *am = &sbi->am;
 552         struct rb_root_cached *root = &am->root;
 553         struct rb_node *node;
 554         struct victim_entry *ve;
 555         unsigned long long total_time;
 556         unsigned long long age, u, accu;
 557         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 558         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 559         unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
 560         unsigned int vblocks;
 561         unsigned int dirty_threshold = max(am->max_candidate_count,
 562                                         am->candidate_ratio *
 563                                         am->victim_count / 100);
 564         unsigned int age_weight = am->age_weight;
 565         unsigned int cost;
 566         unsigned int iter = 0;
 567
 568         if (max_mtime < min_mtime)
 569                 return;
 570
 571         max_mtime += 1;
 572         total_time = max_mtime - min_mtime;
 573
 574         accu = div64_u64(ULLONG_MAX, total_time);
 575         accu = min_t(unsigned long long, div_u64(accu, 100),
 576                                         DEFAULT_ACCURACY_CLASS);
 577
 578         node = rb_first_cached(root);
 579 next:
 580         ve = rb_entry_safe(node, struct victim_entry, rb_node);
 581         if (!ve)
 582                 return;
 583
 584         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 585                 goto skip;
 586
 587         /* age = 10000 * x% * 60 */
 588         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 589                                                                 age_weight;
 590
 591         vblocks = get_valid_blocks(sbi, ve->segno, true);
 592         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 593
 594         /* u = 10000 * x% * 40 */
 595         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 596                                                         (100 - age_weight);
 597
 598         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 599
 600         cost = UINT_MAX - (age + u);
 601         iter++;
 602
 603         if (cost < p->min_cost ||
 604                         (cost == p->min_cost && age > p->oldest_age)) {
 605                 p->min_cost = cost;
 606                 p->oldest_age = age;
 607                 p->min_segno = ve->segno;
 608         }
 609 skip:
 610         if (iter < dirty_threshold) {
 611                 node = rb_next(node);
 612                 goto next;
 613         }
 614 }
 615
 616 /*
 617  * select candidates around source section in range of
 618  * [target - dirty_threshold, target + dirty_threshold]
 619  */
 620 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 621                                                 struct victim_sel_policy *p)
 622 {
 623         struct sit_info *sit_i = SIT_I(sbi);
 624         struct atgc_management *am = &sbi->am;
 625         struct victim_entry *ve;
 626         unsigned long long age;
 627         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 628         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 629         unsigned int vblocks;
 630         unsigned int dirty_threshold = max(am->max_candidate_count,
 631                                         am->candidate_ratio *
 632                                         am->victim_count / 100);
 633         unsigned int cost, iter;
 634         int stage = 0;
 635
 636         if (max_mtime < min_mtime)
 637                 return;
 638         max_mtime += 1;
 639 next_stage:
 640         iter = 0;
 641         ve = __lookup_victim_entry(sbi, p->age);
 642 next_node:
 643         if (!ve) {
 644                 if (stage++ == 0)
 645                         goto next_stage;
 646                 return;
 647         }
 648
 649         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 650                 goto skip_node;
 651
 652         age = max_mtime - ve->mtime;
 653
 654         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 655         f2fs_bug_on(sbi, !vblocks);
 656
 657         /* rare case */
 658         if (vblocks == BLKS_PER_SEG(sbi))
 659                 goto skip_node;
 660
 661         iter++;
 662
 663         age = max_mtime - abs(p->age - age);
 664         cost = UINT_MAX - vblocks;
 665
 666         if (cost < p->min_cost ||
 667                         (cost == p->min_cost && age > p->oldest_age)) {
 668                 p->min_cost = cost;
 669                 p->oldest_age = age;
 670                 p->min_segno = ve->segno;
 671         }
 672 skip_node:
 673         if (iter < dirty_threshold) {
 674                 ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
 675                                         rb_next(&ve->rb_node),
 676                                         struct victim_entry, rb_node);
 677                 goto next_node;
 678         }
 679
 680         if (stage++ == 0)
 681                 goto next_stage;
 682 }
 683
 684 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 685                                                 struct victim_sel_policy *p)
 686 {
 687         f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
 688
 689         if (p->gc_mode == GC_AT)
 690                 atgc_lookup_victim(sbi, p);
 691         else if (p->alloc_mode == AT_SSR)
 692                 atssr_lookup_victim(sbi, p);
 693         else
 694                 f2fs_bug_on(sbi, 1);
 695 }
 696
 697 static void release_victim_entry(struct f2fs_sb_info *sbi)
 698 {
 699         struct atgc_management *am = &sbi->am;
 700         struct victim_entry *ve, *tmp;
 701
 702         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 703                 list_del(&ve->list);
 704                 kmem_cache_free(victim_entry_slab, ve);
 705                 am->victim_count--;
 706         }
 707
 708         am->root = RB_ROOT_CACHED;
 709
 710         f2fs_bug_on(sbi, am->victim_count);
 711         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 712 }
 713
 714 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
 715 {
 716         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 717         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 718
 719         if (!dirty_i->enable_pin_section)
 720                 return false;
 721         if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
 722                 dirty_i->pinned_secmap_cnt++;
 723         return true;
 724 }
 725
 726 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
 727 {
 728         return dirty_i->pinned_secmap_cnt;
 729 }
 730
 731 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
 732                                                 unsigned int secno)
 733 {
 734         return dirty_i->enable_pin_section &&
 735                 f2fs_pinned_section_exists(dirty_i) &&
 736                 test_bit(secno, dirty_i->pinned_secmap);
 737 }
 738
 739 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
 740 {
 741         unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 742
 743         if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
 744                 memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
 745                 DIRTY_I(sbi)->pinned_secmap_cnt = 0;
 746         }
 747         DIRTY_I(sbi)->enable_pin_section = enable;
 748 }
 749
 750 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
 751                                                         unsigned int segno)
 752 {
 753         if (!f2fs_is_pinned_file(inode))
 754                 return 0;
 755         if (gc_type != FG_GC)
 756                 return -EBUSY;
 757         if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
 758                 f2fs_pin_file_control(inode, true);
 759         return -EAGAIN;
 760 }
 761
 762 /*
 763  * This function is called from two paths.
 764  * One is garbage collection and the other is SSR segment selection.
 765  * When it is called during GC, it just gets a victim segment
 766  * and it does not remove it from dirty seglist.
 767  * When it is called from SSR segment selection, it finds a segment
 768  * which has minimum valid blocks and removes it from dirty seglist.
 769  */
 770 int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result,
 771                         int gc_type, int type, char alloc_mode,
 772                         unsigned long long age, bool one_time)
 773 {
 774         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 775         struct sit_info *sm = SIT_I(sbi);
 776         struct victim_sel_policy p;
 777         unsigned int secno, last_victim;
 778         unsigned int last_segment;
 779         unsigned int nsearched;
 780         bool is_atgc;
 781         int ret = 0;
 782
 783         mutex_lock(&dirty_i->seglist_lock);
 784         last_segment = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
 785
 786         p.alloc_mode = alloc_mode;
 787         p.age = age;
 788         p.age_threshold = sbi->am.age_threshold;
 789         p.one_time_gc = one_time;
 790
 791 retry:
 792         select_policy(sbi, gc_type, type, &p);
 793         p.min_segno = NULL_SEGNO;
 794         p.oldest_age = 0;
 795         p.min_cost = get_max_cost(sbi, &p);
 796
 797         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 798         nsearched = 0;
 799
 800         if (is_atgc)
 801                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 802
 803         if (*result != NULL_SEGNO) {
 804                 if (!get_valid_blocks(sbi, *result, false)) {
 805                         ret = -ENODATA;
 806                         goto out;
 807                 }
 808
 809                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 810                         ret = -EBUSY;
 811                 else
 812                         p.min_segno = *result;
 813                 goto out;
 814         }
 815
 816         ret = -ENODATA;
 817         if (p.max_search == 0)
 818                 goto out;
 819
 820         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 821                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 822                         p.min_segno = sbi->next_victim_seg[BG_GC];
 823                         *result = p.min_segno;
 824                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 825                         goto got_result;
 826                 }
 827                 if (gc_type == FG_GC &&
 828                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 829                         p.min_segno = sbi->next_victim_seg[FG_GC];
 830                         *result = p.min_segno;
 831                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 832                         goto got_result;
 833                 }
 834         }
 835
 836         last_victim = sm->last_victim[p.gc_mode];
 837         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 838                 p.min_segno = check_bg_victims(sbi);
 839                 if (p.min_segno != NULL_SEGNO)
 840                         goto got_it;
 841         }
 842
 843         while (1) {
 844                 unsigned long cost, *dirty_bitmap;
 845                 unsigned int unit_no, segno;
 846
 847                 dirty_bitmap = p.dirty_bitmap;
 848                 unit_no = find_next_bit(dirty_bitmap,
 849                                 last_segment / p.ofs_unit,
 850                                 p.offset / p.ofs_unit);
 851                 segno = unit_no * p.ofs_unit;
 852                 if (segno >= last_segment) {
 853                         if (sm->last_victim[p.gc_mode]) {
 854                                 last_segment =
 855                                         sm->last_victim[p.gc_mode];
 856                                 sm->last_victim[p.gc_mode] = 0;
 857                                 p.offset = 0;
 858                                 continue;
 859                         }
 860                         break;
 861                 }
 862
 863                 p.offset = segno + p.ofs_unit;
 864                 nsearched++;
 865
 866 #ifdef CONFIG_F2FS_CHECK_FS
 867                 /*
 868                  * skip selecting the invalid segno (that is failed due to block
 869                  * validity check failure during GC) to avoid endless GC loop in
 870                  * such cases.
 871                  */
 872                 if (test_bit(segno, sm->invalid_segmap))
 873                         goto next;
 874 #endif
 875
 876                 secno = GET_SEC_FROM_SEG(sbi, segno);
 877
 878                 if (sec_usage_check(sbi, secno))
 879                         goto next;
 880
 881                 /* Don't touch checkpointed data */
 882                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 883                         if (p.alloc_mode == LFS) {
 884                                 /*
 885                                  * LFS is set to find source section during GC.
 886                                  * The victim should have no checkpointed data.
 887                                  */
 888                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 889                                         goto next;
 890                         } else {
 891                                 /*
 892                                  * SSR | AT_SSR are set to find target segment
 893                                  * for writes which can be full by checkpointed
 894                                  * and newly written blocks.
 895                                  */
 896                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 897                                         goto next;
 898                         }
 899                 }
 900
 901                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 902                         goto next;
 903
 904                 if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
 905                         goto next;
 906
 907                 if (is_atgc) {
 908                         add_victim_entry(sbi, &p, segno);
 909                         goto next;
 910                 }
 911
 912                 cost = get_gc_cost(sbi, segno, &p);
 913
 914                 if (p.min_cost > cost) {
 915                         p.min_segno = segno;
 916                         p.min_cost = cost;
 917                 }
 918 next:
 919                 if (nsearched >= p.max_search) {
 920                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 921                                 sm->last_victim[p.gc_mode] =
 922                                         last_victim + p.ofs_unit;
 923                         else
 924                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 925                         sm->last_victim[p.gc_mode] %=
 926                                 (MAIN_SECS(sbi) * SEGS_PER_SEC(sbi));
 927                         break;
 928                 }
 929         }
 930
 931         /* get victim for GC_AT/AT_SSR */
 932         if (is_atgc) {
 933                 lookup_victim_by_age(sbi, &p);
 934                 release_victim_entry(sbi);
 935         }
 936
 937         if (is_atgc && p.min_segno == NULL_SEGNO &&
 938                         sm->elapsed_time < p.age_threshold) {
 939                 p.age_threshold = 0;
 940                 goto retry;
 941         }
 942
 943         if (p.min_segno != NULL_SEGNO) {
 944 got_it:
 945                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 946 got_result:
 947                 if (p.alloc_mode == LFS) {
 948                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 949                         if (gc_type == FG_GC)
 950                                 sbi->cur_victim_sec = secno;
 951                         else
 952                                 set_bit(secno, dirty_i->victim_secmap);
 953                 }
 954                 ret = 0;
 955
 956         }
 957 out:
 958         if (p.min_segno != NULL_SEGNO)
 959                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 960                                 sbi->cur_victim_sec,
 961                                 prefree_segments(sbi), free_segments(sbi));
 962         mutex_unlock(&dirty_i->seglist_lock);
 963
 964         return ret;
 965 }
 966
 967 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 968 {
 969         struct inode_entry *ie;
 970
 971         ie = radix_tree_lookup(&gc_list->iroot, ino);
 972         if (ie)
 973                 return ie->inode;
 974         return NULL;
 975 }
 976
 977 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 978 {
 979         struct inode_entry *new_ie;
 980
 981         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 982                 iput(inode);
 983                 return;
 984         }
 985         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 986                                         GFP_NOFS, true, NULL);
 987         new_ie->inode = inode;
 988
 989         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 990         list_add_tail(&new_ie->list, &gc_list->ilist);
 991 }
 992
 993 static void put_gc_inode(struct gc_inode_list *gc_list)
 994 {
 995         struct inode_entry *ie, *next_ie;
 996
 997         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 998                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 999                 iput(ie->inode);
1000                 list_del(&ie->list);
1001                 kmem_cache_free(f2fs_inode_entry_slab, ie);
1002         }
1003 }
1004
1005 static int check_valid_map(struct f2fs_sb_info *sbi,
1006                                 unsigned int segno, int offset)
1007 {
1008         struct sit_info *sit_i = SIT_I(sbi);
1009         struct seg_entry *sentry;
1010         int ret;
1011
1012         down_read(&sit_i->sentry_lock);
1013         sentry = get_seg_entry(sbi, segno);
1014         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
1015         up_read(&sit_i->sentry_lock);
1016         return ret;
1017 }
1018
1019 /*
1020  * This function compares node address got in summary with that in NAT.
1021  * On validity, copy that node with cold status, otherwise (invalid node)
1022  * ignore that.
1023  */
1024 static int gc_node_segment(struct f2fs_sb_info *sbi,
1025                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
1026 {
1027         struct f2fs_summary *entry;
1028         block_t start_addr;
1029         int off;
1030         int phase = 0;
1031         bool fggc = (gc_type == FG_GC);
1032         int submitted = 0;
1033         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1034
1035         start_addr = START_BLOCK(sbi, segno);
1036
1037 next_step:
1038         entry = sum;
1039
1040         if (fggc && phase == 2)
1041                 atomic_inc(&sbi->wb_sync_req[NODE]);
1042
1043         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1044                 nid_t nid = le32_to_cpu(entry->nid);
1045                 struct page *node_page;
1046                 struct node_info ni;
1047                 int err;
1048
1049                 /* stop BG_GC if there is not enough free sections. */
1050                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
1051                         return submitted;
1052
1053                 if (check_valid_map(sbi, segno, off) == 0)
1054                         continue;
1055
1056                 if (phase == 0) {
1057                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1058                                                         META_NAT, true);
1059                         continue;
1060                 }
1061
1062                 if (phase == 1) {
1063                         f2fs_ra_node_page(sbi, nid);
1064                         continue;
1065                 }
1066
1067                 /* phase == 2 */
1068                 node_page = f2fs_get_node_page(sbi, nid);
1069                 if (IS_ERR(node_page))
1070                         continue;
1071
1072                 /* block may become invalid during f2fs_get_node_page */
1073                 if (check_valid_map(sbi, segno, off) == 0) {
1074                         f2fs_put_page(node_page, 1);
1075                         continue;
1076                 }
1077
1078                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1079                         f2fs_put_page(node_page, 1);
1080                         continue;
1081                 }
1082
1083                 if (ni.blk_addr != start_addr + off) {
1084                         f2fs_put_page(node_page, 1);
1085                         continue;
1086                 }
1087
1088                 err = f2fs_move_node_page(node_page, gc_type);
1089                 if (!err && gc_type == FG_GC)
1090                         submitted++;
1091                 stat_inc_node_blk_count(sbi, 1, gc_type);
1092         }
1093
1094         if (++phase < 3)
1095                 goto next_step;
1096
1097         if (fggc)
1098                 atomic_dec(&sbi->wb_sync_req[NODE]);
1099         return submitted;
1100 }
1101
1102 /*
1103  * Calculate start block index indicating the given node offset.
1104  * Be careful, caller should give this node offset only indicating direct node
1105  * blocks. If any node offsets, which point the other types of node blocks such
1106  * as indirect or double indirect node blocks, are given, it must be a caller's
1107  * bug.
1108  */
1109 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1110 {
1111         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1112         unsigned int bidx;
1113
1114         if (node_ofs == 0)
1115                 return 0;
1116
1117         if (node_ofs <= 2) {
1118                 bidx = node_ofs - 1;
1119         } else if (node_ofs <= indirect_blks) {
1120                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1121
1122                 bidx = node_ofs - 2 - dec;
1123         } else {
1124                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1125
1126                 bidx = node_ofs - 5 - dec;
1127         }
1128         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1129 }
1130
1131 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1132                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1133 {
1134         struct page *node_page;
1135         nid_t nid;
1136         unsigned int ofs_in_node, max_addrs, base;
1137         block_t source_blkaddr;
1138
1139         nid = le32_to_cpu(sum->nid);
1140         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1141
1142         node_page = f2fs_get_node_page(sbi, nid);
1143         if (IS_ERR(node_page))
1144                 return false;
1145
1146         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1147                 f2fs_put_page(node_page, 1);
1148                 return false;
1149         }
1150
1151         if (sum->version != dni->version) {
1152                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1153                           __func__);
1154                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1155         }
1156
1157         if (f2fs_check_nid_range(sbi, dni->ino)) {
1158                 f2fs_put_page(node_page, 1);
1159                 return false;
1160         }
1161
1162         if (IS_INODE(node_page)) {
1163                 base = offset_in_addr(F2FS_INODE(node_page));
1164                 max_addrs = DEF_ADDRS_PER_INODE;
1165         } else {
1166                 base = 0;
1167                 max_addrs = DEF_ADDRS_PER_BLOCK;
1168         }
1169
1170         if (base + ofs_in_node >= max_addrs) {
1171                 f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1172                         base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1173                 f2fs_put_page(node_page, 1);
1174                 return false;
1175         }
1176
1177         *nofs = ofs_of_node(node_page);
1178         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1179         f2fs_put_page(node_page, 1);
1180
1181         if (source_blkaddr != blkaddr) {
1182 #ifdef CONFIG_F2FS_CHECK_FS
1183                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1184                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1185
1186                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1187                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1188                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1189                                          blkaddr, source_blkaddr, segno);
1190                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1191                         }
1192                 }
1193 #endif
1194                 return false;
1195         }
1196         return true;
1197 }
1198
1199 static int ra_data_block(struct inode *inode, pgoff_t index)
1200 {
1201         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1202         struct address_space *mapping = f2fs_is_cow_file(inode) ?
1203                                 F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping;
1204         struct dnode_of_data dn;
1205         struct page *page;
1206         struct f2fs_io_info fio = {
1207                 .sbi = sbi,
1208                 .ino = inode->i_ino,
1209                 .type = DATA,
1210                 .temp = COLD,
1211                 .op = REQ_OP_READ,
1212                 .op_flags = 0,
1213                 .encrypted_page = NULL,
1214                 .in_list = 0,
1215         };
1216         int err;
1217
1218         page = f2fs_grab_cache_page(mapping, index, true);
1219         if (!page)
1220                 return -ENOMEM;
1221
1222         if (f2fs_lookup_read_extent_cache_block(inode, index,
1223                                                 &dn.data_blkaddr)) {
1224                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1225                                                 DATA_GENERIC_ENHANCE_READ))) {
1226                         err = -EFSCORRUPTED;
1227                         goto put_page;
1228                 }
1229                 goto got_it;
1230         }
1231
1232         set_new_dnode(&dn, inode, NULL, NULL, 0);
1233         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1234         if (err)
1235                 goto put_page;
1236         f2fs_put_dnode(&dn);
1237
1238         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1239                 err = -ENOENT;
1240                 goto put_page;
1241         }
1242         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1243                                                 DATA_GENERIC_ENHANCE))) {
1244                 err = -EFSCORRUPTED;
1245                 goto put_page;
1246         }
1247 got_it:
1248         /* read page */
1249         fio.page = page;
1250         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1251
1252         /*
1253          * don't cache encrypted data into meta inode until previous dirty
1254          * data were writebacked to avoid racing between GC and flush.
1255          */
1256         f2fs_wait_on_page_writeback(page, DATA, true, true);
1257
1258         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1259
1260         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1261                                         dn.data_blkaddr,
1262                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1263         if (!fio.encrypted_page) {
1264                 err = -ENOMEM;
1265                 goto put_page;
1266         }
1267
1268         err = f2fs_submit_page_bio(&fio);
1269         if (err)
1270                 goto put_encrypted_page;
1271         f2fs_put_page(fio.encrypted_page, 0);
1272         f2fs_put_page(page, 1);
1273
1274         f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1275         f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1276
1277         return 0;
1278 put_encrypted_page:
1279         f2fs_put_page(fio.encrypted_page, 1);
1280 put_page:
1281         f2fs_put_page(page, 1);
1282         return err;
1283 }
1284
1285 /*
1286  * Move data block via META_MAPPING while keeping locked data page.
1287  * This can be used to move blocks, aka LBAs, directly on disk.
1288  */
1289 static int move_data_block(struct inode *inode, block_t bidx,
1290                                 int gc_type, unsigned int segno, int off)
1291 {
1292         struct address_space *mapping = f2fs_is_cow_file(inode) ?
1293                                 F2FS_I(inode)->atomic_inode->i_mapping : inode->i_mapping;
1294         struct f2fs_io_info fio = {
1295                 .sbi = F2FS_I_SB(inode),
1296                 .ino = inode->i_ino,
1297                 .type = DATA,
1298                 .temp = COLD,
1299                 .op = REQ_OP_READ,
1300                 .op_flags = 0,
1301                 .encrypted_page = NULL,
1302                 .in_list = 0,
1303         };
1304         struct dnode_of_data dn;
1305         struct f2fs_summary sum;
1306         struct node_info ni;
1307         struct page *page, *mpage;
1308         block_t newaddr;
1309         int err = 0;
1310         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1311         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1312                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1313                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1314
1315         /* do not read out */
1316         page = f2fs_grab_cache_page(mapping, bidx, false);
1317         if (!page)
1318                 return -ENOMEM;
1319
1320         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1321                 err = -ENOENT;
1322                 goto out;
1323         }
1324
1325         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1326         if (err)
1327                 goto out;
1328
1329         set_new_dnode(&dn, inode, NULL, NULL, 0);
1330         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1331         if (err)
1332                 goto out;
1333
1334         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1335                 ClearPageUptodate(page);
1336                 err = -ENOENT;
1337                 goto put_out;
1338         }
1339
1340         /*
1341          * don't cache encrypted data into meta inode until previous dirty
1342          * data were writebacked to avoid racing between GC and flush.
1343          */
1344         f2fs_wait_on_page_writeback(page, DATA, true, true);
1345
1346         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1347
1348         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1349         if (err)
1350                 goto put_out;
1351
1352         /* read page */
1353         fio.page = page;
1354         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1355
1356         if (lfs_mode)
1357                 f2fs_down_write(&fio.sbi->io_order_lock);
1358
1359         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1360                                         fio.old_blkaddr, false);
1361         if (!mpage) {
1362                 err = -ENOMEM;
1363                 goto up_out;
1364         }
1365
1366         fio.encrypted_page = mpage;
1367
1368         /* read source block in mpage */
1369         if (!PageUptodate(mpage)) {
1370                 err = f2fs_submit_page_bio(&fio);
1371                 if (err) {
1372                         f2fs_put_page(mpage, 1);
1373                         goto up_out;
1374                 }
1375
1376                 f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1377                                                         F2FS_BLKSIZE);
1378                 f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1379                                                         F2FS_BLKSIZE);
1380
1381                 lock_page(mpage);
1382                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1383                                                 !PageUptodate(mpage))) {
1384                         err = -EIO;
1385                         f2fs_put_page(mpage, 1);
1386                         goto up_out;
1387                 }
1388         }
1389
1390         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1391
1392         /* allocate block address */
1393         err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1394                                 &sum, type, NULL);
1395         if (err) {
1396                 f2fs_put_page(mpage, 1);
1397                 /* filesystem should shutdown, no need to recovery block */
1398                 goto up_out;
1399         }
1400
1401         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1402                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1403         if (!fio.encrypted_page) {
1404                 err = -ENOMEM;
1405                 f2fs_put_page(mpage, 1);
1406                 goto recover_block;
1407         }
1408
1409         /* write target block */
1410         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1411         memcpy(page_address(fio.encrypted_page),
1412                                 page_address(mpage), PAGE_SIZE);
1413         f2fs_put_page(mpage, 1);
1414
1415         f2fs_invalidate_internal_cache(fio.sbi, fio.old_blkaddr);
1416
1417         set_page_dirty(fio.encrypted_page);
1418         if (clear_page_dirty_for_io(fio.encrypted_page))
1419                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1420
1421         set_page_writeback(fio.encrypted_page);
1422
1423         fio.op = REQ_OP_WRITE;
1424         fio.op_flags = REQ_SYNC;
1425         fio.new_blkaddr = newaddr;
1426         f2fs_submit_page_write(&fio);
1427
1428         f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1429
1430         f2fs_update_data_blkaddr(&dn, newaddr);
1431         set_inode_flag(inode, FI_APPEND_WRITE);
1432
1433         f2fs_put_page(fio.encrypted_page, 1);
1434 recover_block:
1435         if (err)
1436                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1437                                                         true, true, true);
1438 up_out:
1439         if (lfs_mode)
1440                 f2fs_up_write(&fio.sbi->io_order_lock);
1441 put_out:
1442         f2fs_put_dnode(&dn);
1443 out:
1444         f2fs_put_page(page, 1);
1445         return err;
1446 }
1447
1448 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1449                                                         unsigned int segno, int off)
1450 {
1451         struct page *page;
1452         int err = 0;
1453
1454         page = f2fs_get_lock_data_page(inode, bidx, true);
1455         if (IS_ERR(page))
1456                 return PTR_ERR(page);
1457
1458         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1459                 err = -ENOENT;
1460                 goto out;
1461         }
1462
1463         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1464         if (err)
1465                 goto out;
1466
1467         if (gc_type == BG_GC) {
1468                 if (folio_test_writeback(page_folio(page))) {
1469                         err = -EAGAIN;
1470                         goto out;
1471                 }
1472                 set_page_dirty(page);
1473                 set_page_private_gcing(page);
1474         } else {
1475                 struct f2fs_io_info fio = {
1476                         .sbi = F2FS_I_SB(inode),
1477                         .ino = inode->i_ino,
1478                         .type = DATA,
1479                         .temp = COLD,
1480                         .op = REQ_OP_WRITE,
1481                         .op_flags = REQ_SYNC,
1482                         .old_blkaddr = NULL_ADDR,
1483                         .page = page,
1484                         .encrypted_page = NULL,
1485                         .need_lock = LOCK_REQ,
1486                         .io_type = FS_GC_DATA_IO,
1487                 };
1488                 bool is_dirty = PageDirty(page);
1489
1490 retry:
1491                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1492
1493                 set_page_dirty(page);
1494                 if (clear_page_dirty_for_io(page)) {
1495                         inode_dec_dirty_pages(inode);
1496                         f2fs_remove_dirty_inode(inode);
1497                 }
1498
1499                 set_page_private_gcing(page);
1500
1501                 err = f2fs_do_write_data_page(&fio);
1502                 if (err) {
1503                         clear_page_private_gcing(page);
1504                         if (err == -ENOMEM) {
1505                                 memalloc_retry_wait(GFP_NOFS);
1506                                 goto retry;
1507                         }
1508                         if (is_dirty)
1509                                 set_page_dirty(page);
1510                 }
1511         }
1512 out:
1513         f2fs_put_page(page, 1);
1514         return err;
1515 }
1516
1517 /*
1518  * This function tries to get parent node of victim data block, and identifies
1519  * data block validity. If the block is valid, copy that with cold status and
1520  * modify parent node.
1521  * If the parent node is not valid or the data block address is different,
1522  * the victim data block is ignored.
1523  */
1524 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1525                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1526                 bool force_migrate)
1527 {
1528         struct super_block *sb = sbi->sb;
1529         struct f2fs_summary *entry;
1530         block_t start_addr;
1531         int off;
1532         int phase = 0;
1533         int submitted = 0;
1534         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1535
1536         start_addr = START_BLOCK(sbi, segno);
1537
1538 next_step:
1539         entry = sum;
1540
1541         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1542                 struct page *data_page;
1543                 struct inode *inode;
1544                 struct node_info dni; /* dnode info for the data */
1545                 unsigned int ofs_in_node, nofs;
1546                 block_t start_bidx;
1547                 nid_t nid = le32_to_cpu(entry->nid);
1548
1549                 /*
1550                  * stop BG_GC if there is not enough free sections.
1551                  * Or, stop GC if the segment becomes fully valid caused by
1552                  * race condition along with SSR block allocation.
1553                  */
1554                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1555                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1556                                                         CAP_BLKS_PER_SEC(sbi)))
1557                         return submitted;
1558
1559                 if (check_valid_map(sbi, segno, off) == 0)
1560                         continue;
1561
1562                 if (phase == 0) {
1563                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1564                                                         META_NAT, true);
1565                         continue;
1566                 }
1567
1568                 if (phase == 1) {
1569                         f2fs_ra_node_page(sbi, nid);
1570                         continue;
1571                 }
1572
1573                 /* Get an inode by ino with checking validity */
1574                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1575                         continue;
1576
1577                 if (phase == 2) {
1578                         f2fs_ra_node_page(sbi, dni.ino);
1579                         continue;
1580                 }
1581
1582                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1583
1584                 if (phase == 3) {
1585                         int err;
1586
1587                         inode = f2fs_iget(sb, dni.ino);
1588                         if (IS_ERR(inode))
1589                                 continue;
1590
1591                         if (is_bad_inode(inode) ||
1592                                         special_file(inode->i_mode)) {
1593                                 iput(inode);
1594                                 continue;
1595                         }
1596
1597                         if (f2fs_has_inline_data(inode)) {
1598                                 iput(inode);
1599                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1600                                 f2fs_err_ratelimited(sbi,
1601                                         "inode %lx has both inline_data flag and "
1602                                         "data block, nid=%u, ofs_in_node=%u",
1603                                         inode->i_ino, dni.nid, ofs_in_node);
1604                                 continue;
1605                         }
1606
1607                         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1608                         if (err == -EAGAIN) {
1609                                 iput(inode);
1610                                 return submitted;
1611                         }
1612
1613                         if (!f2fs_down_write_trylock(
1614                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1615                                 iput(inode);
1616                                 sbi->skipped_gc_rwsem++;
1617                                 continue;
1618                         }
1619
1620                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1621                                                                 ofs_in_node;
1622
1623                         if (f2fs_meta_inode_gc_required(inode)) {
1624                                 int err = ra_data_block(inode, start_bidx);
1625
1626                                 f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1627                                 if (err) {
1628                                         iput(inode);
1629                                         continue;
1630                                 }
1631                                 add_gc_inode(gc_list, inode);
1632                                 continue;
1633                         }
1634
1635                         data_page = f2fs_get_read_data_page(inode, start_bidx,
1636                                                         REQ_RAHEAD, true, NULL);
1637                         f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1638                         if (IS_ERR(data_page)) {
1639                                 iput(inode);
1640                                 continue;
1641                         }
1642
1643                         f2fs_put_page(data_page, 0);
1644                         add_gc_inode(gc_list, inode);
1645                         continue;
1646                 }
1647
1648                 /* phase 4 */
1649                 inode = find_gc_inode(gc_list, dni.ino);
1650                 if (inode) {
1651                         struct f2fs_inode_info *fi = F2FS_I(inode);
1652                         bool locked = false;
1653                         int err;
1654
1655                         if (S_ISREG(inode->i_mode)) {
1656                                 if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[WRITE])) {
1657                                         sbi->skipped_gc_rwsem++;
1658                                         continue;
1659                                 }
1660                                 if (!f2fs_down_write_trylock(
1661                                                 &fi->i_gc_rwsem[READ])) {
1662                                         sbi->skipped_gc_rwsem++;
1663                                         f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1664                                         continue;
1665                                 }
1666                                 locked = true;
1667
1668                                 /* wait for all inflight aio data */
1669                                 inode_dio_wait(inode);
1670                         }
1671
1672                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1673                                                                 + ofs_in_node;
1674                         if (f2fs_meta_inode_gc_required(inode))
1675                                 err = move_data_block(inode, start_bidx,
1676                                                         gc_type, segno, off);
1677                         else
1678                                 err = move_data_page(inode, start_bidx, gc_type,
1679                                                                 segno, off);
1680
1681                         if (!err && (gc_type == FG_GC ||
1682                                         f2fs_meta_inode_gc_required(inode)))
1683                                 submitted++;
1684
1685                         if (locked) {
1686                                 f2fs_up_write(&fi->i_gc_rwsem[READ]);
1687                                 f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1688                         }
1689
1690                         stat_inc_data_blk_count(sbi, 1, gc_type);
1691                 }
1692         }
1693
1694         if (++phase < 5)
1695                 goto next_step;
1696
1697         return submitted;
1698 }
1699
1700 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1701                         int gc_type, bool one_time)
1702 {
1703         struct sit_info *sit_i = SIT_I(sbi);
1704         int ret;
1705
1706         down_write(&sit_i->sentry_lock);
1707         ret = f2fs_get_victim(sbi, victim, gc_type, NO_CHECK_TYPE,
1708                         LFS, 0, one_time);
1709         up_write(&sit_i->sentry_lock);
1710         return ret;
1711 }
1712
1713 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1714                                 unsigned int start_segno,
1715                                 struct gc_inode_list *gc_list, int gc_type,
1716                                 bool force_migrate, bool one_time)
1717 {
1718         struct page *sum_page;
1719         struct f2fs_summary_block *sum;
1720         struct blk_plug plug;
1721         unsigned int segno = start_segno;
1722         unsigned int end_segno = start_segno + SEGS_PER_SEC(sbi);
1723         unsigned int sec_end_segno;
1724         int seg_freed = 0, migrated = 0;
1725         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1726                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1727         unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
1728         int submitted = 0;
1729
1730         if (__is_large_section(sbi)) {
1731                 sec_end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
1732
1733                 /*
1734                  * zone-capacity can be less than zone-size in zoned devices,
1735                  * resulting in less than expected usable segments in the zone,
1736                  * calculate the end segno in the zone which can be garbage
1737                  * collected
1738                  */
1739                 if (f2fs_sb_has_blkzoned(sbi))
1740                         sec_end_segno -= SEGS_PER_SEC(sbi) -
1741                                         f2fs_usable_segs_in_sec(sbi);
1742
1743                 if (gc_type == BG_GC || one_time) {
1744                         unsigned int window_granularity =
1745                                 sbi->migration_window_granularity;
1746
1747                         if (f2fs_sb_has_blkzoned(sbi) &&
1748                                         !has_enough_free_blocks(sbi,
1749                                         sbi->gc_thread->boost_zoned_gc_percent))
1750                                 window_granularity *=
1751                                         BOOST_GC_MULTIPLE;
1752
1753                         end_segno = start_segno + window_granularity;
1754                 }
1755
1756                 if (end_segno > sec_end_segno)
1757                         end_segno = sec_end_segno;
1758         }
1759
1760         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1761
1762         /* readahead multi ssa blocks those have contiguous address */
1763         if (__is_large_section(sbi))
1764                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1765                                         end_segno - segno, META_SSA, true);
1766
1767         /* reference all summary page */
1768         while (segno < end_segno) {
1769                 sum_page = f2fs_get_sum_page(sbi, segno++);
1770                 if (IS_ERR(sum_page)) {
1771                         int err = PTR_ERR(sum_page);
1772
1773                         end_segno = segno - 1;
1774                         for (segno = start_segno; segno < end_segno; segno++) {
1775                                 sum_page = find_get_page(META_MAPPING(sbi),
1776                                                 GET_SUM_BLOCK(sbi, segno));
1777                                 f2fs_put_page(sum_page, 0);
1778                                 f2fs_put_page(sum_page, 0);
1779                         }
1780                         return err;
1781                 }
1782                 unlock_page(sum_page);
1783         }
1784
1785         blk_start_plug(&plug);
1786
1787         for (segno = start_segno; segno < end_segno; segno++) {
1788
1789                 /* find segment summary of victim */
1790                 sum_page = find_get_page(META_MAPPING(sbi),
1791                                         GET_SUM_BLOCK(sbi, segno));
1792                 f2fs_put_page(sum_page, 0);
1793
1794                 if (get_valid_blocks(sbi, segno, false) == 0)
1795                         goto freed;
1796                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1797                                 migrated >= sbi->migration_granularity)
1798                         goto skip;
1799                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1800                         goto skip;
1801
1802                 sum = page_address(sum_page);
1803                 if (type != GET_SUM_TYPE((&sum->footer))) {
1804                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1805                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1806                         f2fs_stop_checkpoint(sbi, false,
1807                                 STOP_CP_REASON_CORRUPTED_SUMMARY);
1808                         goto skip;
1809                 }
1810
1811                 /*
1812                  * this is to avoid deadlock:
1813                  * - lock_page(sum_page)         - f2fs_replace_block
1814                  *  - check_valid_map()            - down_write(sentry_lock)
1815                  *   - down_read(sentry_lock)     - change_curseg()
1816                  *                                  - lock_page(sum_page)
1817                  */
1818                 if (type == SUM_TYPE_NODE)
1819                         submitted += gc_node_segment(sbi, sum->entries, segno,
1820                                                                 gc_type);
1821                 else
1822                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1823                                                         segno, gc_type,
1824                                                         force_migrate);
1825
1826                 stat_inc_gc_seg_count(sbi, data_type, gc_type);
1827                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1828                 migrated++;
1829
1830 freed:
1831                 if (gc_type == FG_GC &&
1832                                 get_valid_blocks(sbi, segno, false) == 0)
1833                         seg_freed++;
1834
1835                 if (__is_large_section(sbi))
1836                         sbi->next_victim_seg[gc_type] =
1837                                 (segno + 1 < sec_end_segno) ?
1838                                         segno + 1 : NULL_SEGNO;
1839 skip:
1840                 f2fs_put_page(sum_page, 0);
1841         }
1842
1843         if (submitted)
1844                 f2fs_submit_merged_write(sbi, data_type);
1845
1846         blk_finish_plug(&plug);
1847
1848         if (migrated)
1849                 stat_inc_gc_sec_count(sbi, data_type, gc_type);
1850
1851         return seg_freed;
1852 }
1853
1854 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1855 {
1856         int gc_type = gc_control->init_gc_type;
1857         unsigned int segno = gc_control->victim_segno;
1858         int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
1859         int ret = 0;
1860         struct cp_control cpc;
1861         struct gc_inode_list gc_list = {
1862                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1863                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1864         };
1865         unsigned int skipped_round = 0, round = 0;
1866         unsigned int upper_secs;
1867
1868         trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1869                                 gc_control->nr_free_secs,
1870                                 get_pages(sbi, F2FS_DIRTY_NODES),
1871                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1872                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1873                                 free_sections(sbi),
1874                                 free_segments(sbi),
1875                                 reserved_segments(sbi),
1876                                 prefree_segments(sbi));
1877
1878         cpc.reason = __get_cp_reason(sbi);
1879 gc_more:
1880         sbi->skipped_gc_rwsem = 0;
1881         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1882                 ret = -EINVAL;
1883                 goto stop;
1884         }
1885         if (unlikely(f2fs_cp_error(sbi))) {
1886                 ret = -EIO;
1887                 goto stop;
1888         }
1889
1890         /* Let's run FG_GC, if we don't have enough space. */
1891         if (has_not_enough_free_secs(sbi, 0, 0)) {
1892                 gc_type = FG_GC;
1893
1894                 /*
1895                  * For example, if there are many prefree_segments below given
1896                  * threshold, we can make them free by checkpoint. Then, we
1897                  * secure free segments which doesn't need fggc any more.
1898                  */
1899                 if (prefree_segments(sbi)) {
1900                         stat_inc_cp_call_count(sbi, TOTAL_CALL);
1901                         ret = f2fs_write_checkpoint(sbi, &cpc);
1902                         if (ret)
1903                                 goto stop;
1904                         /* Reset due to checkpoint */
1905                         sec_freed = 0;
1906                 }
1907         }
1908
1909         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1910         if (gc_type == BG_GC && gc_control->no_bg_gc) {
1911                 ret = -EINVAL;
1912                 goto stop;
1913         }
1914 retry:
1915         ret = __get_victim(sbi, &segno, gc_type, gc_control->one_time);
1916         if (ret) {
1917                 /* allow to search victim from sections has pinned data */
1918                 if (ret == -ENODATA && gc_type == FG_GC &&
1919                                 f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1920                         f2fs_unpin_all_sections(sbi, false);
1921                         goto retry;
1922                 }
1923                 goto stop;
1924         }
1925
1926         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1927                                 gc_control->should_migrate_blocks,
1928                                 gc_control->one_time);
1929         if (seg_freed < 0)
1930                 goto stop;
1931
1932         total_freed += seg_freed;
1933
1934         if (seg_freed == f2fs_usable_segs_in_sec(sbi)) {
1935                 sec_freed++;
1936                 total_sec_freed++;
1937         }
1938
1939         if (gc_control->one_time)
1940                 goto stop;
1941
1942         if (gc_type == FG_GC) {
1943                 sbi->cur_victim_sec = NULL_SEGNO;
1944
1945                 if (has_enough_free_secs(sbi, sec_freed, 0)) {
1946                         if (!gc_control->no_bg_gc &&
1947                             total_sec_freed < gc_control->nr_free_secs)
1948                                 goto go_gc_more;
1949                         goto stop;
1950                 }
1951                 if (sbi->skipped_gc_rwsem)
1952                         skipped_round++;
1953                 round++;
1954                 if (skipped_round > MAX_SKIP_GC_COUNT &&
1955                                 skipped_round * 2 >= round) {
1956                         stat_inc_cp_call_count(sbi, TOTAL_CALL);
1957                         ret = f2fs_write_checkpoint(sbi, &cpc);
1958                         goto stop;
1959                 }
1960         } else if (has_enough_free_secs(sbi, 0, 0)) {
1961                 goto stop;
1962         }
1963
1964         __get_secs_required(sbi, NULL, &upper_secs, NULL);
1965
1966         /*
1967          * Write checkpoint to reclaim prefree segments.
1968          * We need more three extra sections for writer's data/node/dentry.
1969          */
1970         if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
1971                                 prefree_segments(sbi)) {
1972                 stat_inc_cp_call_count(sbi, TOTAL_CALL);
1973                 ret = f2fs_write_checkpoint(sbi, &cpc);
1974                 if (ret)
1975                         goto stop;
1976                 /* Reset due to checkpoint */
1977                 sec_freed = 0;
1978         }
1979 go_gc_more:
1980         segno = NULL_SEGNO;
1981         goto gc_more;
1982
1983 stop:
1984         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1985         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1986
1987         if (gc_type == FG_GC)
1988                 f2fs_unpin_all_sections(sbi, true);
1989
1990         trace_f2fs_gc_end(sbi->sb, ret, total_freed, total_sec_freed,
1991                                 get_pages(sbi, F2FS_DIRTY_NODES),
1992                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1993                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1994                                 free_sections(sbi),
1995                                 free_segments(sbi),
1996                                 reserved_segments(sbi),
1997                                 prefree_segments(sbi));
1998
1999         f2fs_up_write(&sbi->gc_lock);
2000
2001         put_gc_inode(&gc_list);
2002
2003         if (gc_control->err_gc_skipped && !ret)
2004                 ret = total_sec_freed ? 0 : -EAGAIN;
2005         return ret;
2006 }
2007
2008 int __init f2fs_create_garbage_collection_cache(void)
2009 {
2010         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
2011                                         sizeof(struct victim_entry));
2012         return victim_entry_slab ? 0 : -ENOMEM;
2013 }
2014
2015 void f2fs_destroy_garbage_collection_cache(void)
2016 {
2017         kmem_cache_destroy(victim_entry_slab);
2018 }
2019
2020 static void init_atgc_management(struct f2fs_sb_info *sbi)
2021 {
2022         struct atgc_management *am = &sbi->am;
2023
2024         if (test_opt(sbi, ATGC) &&
2025                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
2026                 am->atgc_enabled = true;
2027
2028         am->root = RB_ROOT_CACHED;
2029         INIT_LIST_HEAD(&am->victim_list);
2030         am->victim_count = 0;
2031
2032         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
2033         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
2034         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
2035         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
2036 }
2037
2038 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
2039 {
2040         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
2041
2042         /* give warm/cold data area from slower device */
2043         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
2044                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
2045                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
2046
2047         init_atgc_management(sbi);
2048 }
2049
2050 int f2fs_gc_range(struct f2fs_sb_info *sbi,
2051                 unsigned int start_seg, unsigned int end_seg,
2052                 bool dry_run, unsigned int dry_run_sections)
2053 {
2054         unsigned int segno;
2055         unsigned int gc_secs = dry_run_sections;
2056
2057         if (unlikely(f2fs_cp_error(sbi)))
2058                 return -EIO;
2059
2060         for (segno = start_seg; segno <= end_seg; segno += SEGS_PER_SEC(sbi)) {
2061                 struct gc_inode_list gc_list = {
2062                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
2063                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
2064                 };
2065
2066                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true, false);
2067                 put_gc_inode(&gc_list);
2068
2069                 if (!dry_run && get_valid_blocks(sbi, segno, true))
2070                         return -EAGAIN;
2071                 if (dry_run && dry_run_sections &&
2072                     !get_valid_blocks(sbi, segno, true) && --gc_secs == 0)
2073                         break;
2074
2075                 if (fatal_signal_pending(current))
2076                         return -ERESTARTSYS;
2077         }
2078
2079         return 0;
2080 }
2081
2082 static int free_segment_range(struct f2fs_sb_info *sbi,
2083                                 unsigned int secs, bool dry_run)
2084 {
2085         unsigned int next_inuse, start, end;
2086         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2087         int gc_mode, gc_type;
2088         int err = 0;
2089         int type;
2090
2091         /* Force block allocation for GC */
2092         MAIN_SECS(sbi) -= secs;
2093         start = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
2094         end = MAIN_SEGS(sbi) - 1;
2095
2096         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2097         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
2098                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
2099                         SIT_I(sbi)->last_victim[gc_mode] = 0;
2100
2101         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
2102                 if (sbi->next_victim_seg[gc_type] >= start)
2103                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
2104         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
2105
2106         /* Move out cursegs from the target range */
2107         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
2108                 err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
2109                 if (err)
2110                         goto out;
2111         }
2112
2113         /* do GC to move out valid blocks in the range */
2114         err = f2fs_gc_range(sbi, start, end, dry_run, 0);
2115         if (err || dry_run)
2116                 goto out;
2117
2118         stat_inc_cp_call_count(sbi, TOTAL_CALL);
2119         err = f2fs_write_checkpoint(sbi, &cpc);
2120         if (err)
2121                 goto out;
2122
2123         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
2124         if (next_inuse <= end) {
2125                 f2fs_err(sbi, "segno %u should be free but still inuse!",
2126                          next_inuse);
2127                 f2fs_bug_on(sbi, 1);
2128         }
2129 out:
2130         MAIN_SECS(sbi) += secs;
2131         return err;
2132 }
2133
2134 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2135 {
2136         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2137         int section_count;
2138         int segment_count;
2139         int segment_count_main;
2140         long long block_count;
2141         int segs = secs * SEGS_PER_SEC(sbi);
2142
2143         f2fs_down_write(&sbi->sb_lock);
2144
2145         section_count = le32_to_cpu(raw_sb->section_count);
2146         segment_count = le32_to_cpu(raw_sb->segment_count);
2147         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2148         block_count = le64_to_cpu(raw_sb->block_count);
2149
2150         raw_sb->section_count = cpu_to_le32(section_count + secs);
2151         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2152         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2153         raw_sb->block_count = cpu_to_le64(block_count +
2154                         (long long)SEGS_TO_BLKS(sbi, segs));
2155         if (f2fs_is_multi_device(sbi)) {
2156                 int last_dev = sbi->s_ndevs - 1;
2157                 int dev_segs =
2158                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2159
2160                 raw_sb->devs[last_dev].total_segments =
2161                                                 cpu_to_le32(dev_segs + segs);
2162         }
2163
2164         f2fs_up_write(&sbi->sb_lock);
2165 }
2166
2167 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2168 {
2169         int segs = secs * SEGS_PER_SEC(sbi);
2170         long long blks = SEGS_TO_BLKS(sbi, segs);
2171         long long user_block_count =
2172                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2173
2174         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2175         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2176         MAIN_SECS(sbi) += secs;
2177         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2178         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2179         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2180
2181         if (f2fs_is_multi_device(sbi)) {
2182                 int last_dev = sbi->s_ndevs - 1;
2183
2184                 FDEV(last_dev).total_segments =
2185                                 (int)FDEV(last_dev).total_segments + segs;
2186                 FDEV(last_dev).end_blk =
2187                                 (long long)FDEV(last_dev).end_blk + blks;
2188 #ifdef CONFIG_BLK_DEV_ZONED
2189                 FDEV(last_dev).nr_blkz = FDEV(last_dev).nr_blkz +
2190                                         div_u64(blks, sbi->blocks_per_blkz);
2191 #endif
2192         }
2193 }
2194
2195 int f2fs_resize_fs(struct file *filp, __u64 block_count)
2196 {
2197         struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2198         __u64 old_block_count, shrunk_blocks;
2199         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2200         unsigned int secs;
2201         int err = 0;
2202         __u32 rem;
2203
2204         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2205         if (block_count > old_block_count)
2206                 return -EINVAL;
2207
2208         if (f2fs_is_multi_device(sbi)) {
2209                 int last_dev = sbi->s_ndevs - 1;
2210                 __u64 last_segs = FDEV(last_dev).total_segments;
2211
2212                 if (block_count + SEGS_TO_BLKS(sbi, last_segs) <=
2213                                                                 old_block_count)
2214                         return -EINVAL;
2215         }
2216
2217         /* new fs size should align to section size */
2218         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2219         if (rem)
2220                 return -EINVAL;
2221
2222         if (block_count == old_block_count)
2223                 return 0;
2224
2225         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2226                 f2fs_err(sbi, "Should run fsck to repair first.");
2227                 return -EFSCORRUPTED;
2228         }
2229
2230         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2231                 f2fs_err(sbi, "Checkpoint should be enabled.");
2232                 return -EINVAL;
2233         }
2234
2235         err = mnt_want_write_file(filp);
2236         if (err)
2237                 return err;
2238
2239         shrunk_blocks = old_block_count - block_count;
2240         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2241
2242         /* stop other GC */
2243         if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
2244                 err = -EAGAIN;
2245                 goto out_drop_write;
2246         }
2247
2248         /* stop CP to protect MAIN_SEC in free_segment_range */
2249         f2fs_lock_op(sbi);
2250
2251         spin_lock(&sbi->stat_lock);
2252         if (shrunk_blocks + valid_user_blocks(sbi) +
2253                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2254                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2255                 err = -ENOSPC;
2256         spin_unlock(&sbi->stat_lock);
2257
2258         if (err)
2259                 goto out_unlock;
2260
2261         err = free_segment_range(sbi, secs, true);
2262
2263 out_unlock:
2264         f2fs_unlock_op(sbi);
2265         f2fs_up_write(&sbi->gc_lock);
2266 out_drop_write:
2267         mnt_drop_write_file(filp);
2268         if (err)
2269                 return err;
2270
2271         err = freeze_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2272         if (err)
2273                 return err;
2274
2275         if (f2fs_readonly(sbi->sb)) {
2276                 err = thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2277                 if (err)
2278                         return err;
2279                 return -EROFS;
2280         }
2281
2282         f2fs_down_write(&sbi->gc_lock);
2283         f2fs_down_write(&sbi->cp_global_sem);
2284
2285         spin_lock(&sbi->stat_lock);
2286         if (shrunk_blocks + valid_user_blocks(sbi) +
2287                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2288                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2289                 err = -ENOSPC;
2290         else
2291                 sbi->user_block_count -= shrunk_blocks;
2292         spin_unlock(&sbi->stat_lock);
2293         if (err)
2294                 goto out_err;
2295
2296         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2297         err = free_segment_range(sbi, secs, false);
2298         if (err)
2299                 goto recover_out;
2300
2301         update_sb_metadata(sbi, -secs);
2302
2303         err = f2fs_commit_super(sbi, false);
2304         if (err) {
2305                 update_sb_metadata(sbi, secs);
2306                 goto recover_out;
2307         }
2308
2309         update_fs_metadata(sbi, -secs);
2310         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2311         set_sbi_flag(sbi, SBI_IS_DIRTY);
2312
2313         stat_inc_cp_call_count(sbi, TOTAL_CALL);
2314         err = f2fs_write_checkpoint(sbi, &cpc);
2315         if (err) {
2316                 update_fs_metadata(sbi, secs);
2317                 update_sb_metadata(sbi, secs);
2318                 f2fs_commit_super(sbi, false);
2319         }
2320 recover_out:
2321         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2322         if (err) {
2323                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2324                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2325
2326                 spin_lock(&sbi->stat_lock);
2327                 sbi->user_block_count += shrunk_blocks;
2328                 spin_unlock(&sbi->stat_lock);
2329         }
2330 out_err:
2331         f2fs_up_write(&sbi->cp_global_sem);
2332         f2fs_up_write(&sbi->gc_lock);
2333         thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2334         return err;
2335 }