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                 /*
  85                  * [GC triggering condition]
  86                  * 0. GC is not conducted currently.
  87                  * 1. There are enough dirty segments.
  88                  * 2. IO subsystem is idle by checking the # of writeback pages.
  89                  * 3. IO subsystem is idle by checking the # of requests in
  90                  *    bdev's request list.
  91                  *
  92                  * Note) We have to avoid triggering GCs frequently.
  93                  * Because it is possible that some segments can be
  94                  * invalidated soon after by user update or deletion.
  95                  * So, I'd like to wait some time to collect dirty segments.
  96                  */
  97                 if (sbi->gc_mode == GC_URGENT_HIGH ||
  98                                 sbi->gc_mode == GC_URGENT_MID) {
  99                         wait_ms = gc_th->urgent_sleep_time;
 100                         f2fs_down_write(&sbi->gc_lock);
 101                         goto do_gc;
 102                 }
 103
 104                 if (foreground) {
 105                         f2fs_down_write(&sbi->gc_lock);
 106                         goto do_gc;
 107                 } else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
 108                         stat_other_skip_bggc_count(sbi);
 109                         goto next;
 110                 }
 111
 112                 if (!is_idle(sbi, GC_TIME)) {
 113                         increase_sleep_time(gc_th, &wait_ms);
 114                         f2fs_up_write(&sbi->gc_lock);
 115                         stat_io_skip_bggc_count(sbi);
 116                         goto next;
 117                 }
 118
 119                 if (has_enough_invalid_blocks(sbi))
 120                         decrease_sleep_time(gc_th, &wait_ms);
 121                 else
 122                         increase_sleep_time(gc_th, &wait_ms);
 123 do_gc:
 124                 stat_inc_gc_call_count(sbi, foreground ?
 125                                         FOREGROUND : BACKGROUND);
 126
 127                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 128
 129                 /* foreground GC was been triggered via f2fs_balance_fs() */
 130                 if (foreground)
 131                         sync_mode = false;
 132
 133                 gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
 134                 gc_control.no_bg_gc = foreground;
 135                 gc_control.nr_free_secs = foreground ? 1 : 0;
 136
 137                 /* if return value is not zero, no victim was selected */
 138                 if (f2fs_gc(sbi, &gc_control)) {
 139                         /* don't bother wait_ms by foreground gc */
 140                         if (!foreground)
 141                                 wait_ms = gc_th->no_gc_sleep_time;
 142                 } else {
 143                         /* reset wait_ms to default sleep time */
 144                         if (wait_ms == gc_th->no_gc_sleep_time)
 145                                 wait_ms = gc_th->min_sleep_time;
 146                 }
 147
 148                 if (foreground)
 149                         wake_up_all(&gc_th->fggc_wq);
 150
 151                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 152                                 prefree_segments(sbi), free_segments(sbi));
 153
 154                 /* balancing f2fs's metadata periodically */
 155                 f2fs_balance_fs_bg(sbi, true);
 156 next:
 157                 if (sbi->gc_mode != GC_NORMAL) {
 158                         spin_lock(&sbi->gc_remaining_trials_lock);
 159                         if (sbi->gc_remaining_trials) {
 160                                 sbi->gc_remaining_trials--;
 161                                 if (!sbi->gc_remaining_trials)
 162                                         sbi->gc_mode = GC_NORMAL;
 163                         }
 164                         spin_unlock(&sbi->gc_remaining_trials_lock);
 165                 }
 166                 sb_end_write(sbi->sb);
 167
 168         } while (!kthread_should_stop());
 169         return 0;
 170 }
 171
 172 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 173 {
 174         struct f2fs_gc_kthread *gc_th;
 175         dev_t dev = sbi->sb->s_bdev->bd_dev;
 176
 177         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 178         if (!gc_th)
 179                 return -ENOMEM;
 180
 181         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 182         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 183         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 184         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 185
 186         gc_th->gc_wake = false;
 187
 188         sbi->gc_thread = gc_th;
 189         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 190         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 191         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 192                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 193         if (IS_ERR(gc_th->f2fs_gc_task)) {
 194                 int err = PTR_ERR(gc_th->f2fs_gc_task);
 195
 196                 kfree(gc_th);
 197                 sbi->gc_thread = NULL;
 198                 return err;
 199         }
 200
 201         return 0;
 202 }
 203
 204 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 205 {
 206         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 207
 208         if (!gc_th)
 209                 return;
 210         kthread_stop(gc_th->f2fs_gc_task);
 211         wake_up_all(&gc_th->fggc_wq);
 212         kfree(gc_th);
 213         sbi->gc_thread = NULL;
 214 }
 215
 216 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 217 {
 218         int gc_mode;
 219
 220         if (gc_type == BG_GC) {
 221                 if (sbi->am.atgc_enabled)
 222                         gc_mode = GC_AT;
 223                 else
 224                         gc_mode = GC_CB;
 225         } else {
 226                 gc_mode = GC_GREEDY;
 227         }
 228
 229         switch (sbi->gc_mode) {
 230         case GC_IDLE_CB:
 231                 gc_mode = GC_CB;
 232                 break;
 233         case GC_IDLE_GREEDY:
 234         case GC_URGENT_HIGH:
 235                 gc_mode = GC_GREEDY;
 236                 break;
 237         case GC_IDLE_AT:
 238                 gc_mode = GC_AT;
 239                 break;
 240         }
 241
 242         return gc_mode;
 243 }
 244
 245 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 246                         int type, struct victim_sel_policy *p)
 247 {
 248         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 249
 250         if (p->alloc_mode == SSR) {
 251                 p->gc_mode = GC_GREEDY;
 252                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 253                 p->max_search = dirty_i->nr_dirty[type];
 254                 p->ofs_unit = 1;
 255         } else if (p->alloc_mode == AT_SSR) {
 256                 p->gc_mode = GC_GREEDY;
 257                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 258                 p->max_search = dirty_i->nr_dirty[type];
 259                 p->ofs_unit = 1;
 260         } else {
 261                 p->gc_mode = select_gc_type(sbi, gc_type);
 262                 p->ofs_unit = SEGS_PER_SEC(sbi);
 263                 if (__is_large_section(sbi)) {
 264                         p->dirty_bitmap = dirty_i->dirty_secmap;
 265                         p->max_search = count_bits(p->dirty_bitmap,
 266                                                 0, MAIN_SECS(sbi));
 267                 } else {
 268                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 269                         p->max_search = dirty_i->nr_dirty[DIRTY];
 270                 }
 271         }
 272
 273         /*
 274          * adjust candidates range, should select all dirty segments for
 275          * foreground GC and urgent GC cases.
 276          */
 277         if (gc_type != FG_GC &&
 278                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 279                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 280                         p->max_search > sbi->max_victim_search)
 281                 p->max_search = sbi->max_victim_search;
 282
 283         /* let's select beginning hot/small space first. */
 284         if (f2fs_need_rand_seg(sbi))
 285                 p->offset = get_random_u32_below(MAIN_SECS(sbi) *
 286                                                 SEGS_PER_SEC(sbi));
 287         else if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
 288                 p->offset = 0;
 289         else
 290                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 291 }
 292
 293 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 294                                 struct victim_sel_policy *p)
 295 {
 296         /* SSR allocates in a segment unit */
 297         if (p->alloc_mode == SSR)
 298                 return BLKS_PER_SEG(sbi);
 299         else if (p->alloc_mode == AT_SSR)
 300                 return UINT_MAX;
 301
 302         /* LFS */
 303         if (p->gc_mode == GC_GREEDY)
 304                 return SEGS_TO_BLKS(sbi, 2 * p->ofs_unit);
 305         else if (p->gc_mode == GC_CB)
 306                 return UINT_MAX;
 307         else if (p->gc_mode == GC_AT)
 308                 return UINT_MAX;
 309         else /* No other gc_mode */
 310                 return 0;
 311 }
 312
 313 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 314 {
 315         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 316         unsigned int secno;
 317
 318         /*
 319          * If the gc_type is FG_GC, we can select victim segments
 320          * selected by background GC before.
 321          * Those segments guarantee they have small valid blocks.
 322          */
 323         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 324                 if (sec_usage_check(sbi, secno))
 325                         continue;
 326                 clear_bit(secno, dirty_i->victim_secmap);
 327                 return GET_SEG_FROM_SEC(sbi, secno);
 328         }
 329         return NULL_SEGNO;
 330 }
 331
 332 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 333 {
 334         struct sit_info *sit_i = SIT_I(sbi);
 335         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 336         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 337         unsigned long long mtime = 0;
 338         unsigned int vblocks;
 339         unsigned char age = 0;
 340         unsigned char u;
 341         unsigned int i;
 342         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 343
 344         for (i = 0; i < usable_segs_per_sec; i++)
 345                 mtime += get_seg_entry(sbi, start + i)->mtime;
 346         vblocks = get_valid_blocks(sbi, segno, true);
 347
 348         mtime = div_u64(mtime, usable_segs_per_sec);
 349         vblocks = div_u64(vblocks, usable_segs_per_sec);
 350
 351         u = BLKS_TO_SEGS(sbi, vblocks * 100);
 352
 353         /* Handle if the system time has changed by the user */
 354         if (mtime < sit_i->min_mtime)
 355                 sit_i->min_mtime = mtime;
 356         if (mtime > sit_i->max_mtime)
 357                 sit_i->max_mtime = mtime;
 358         if (sit_i->max_mtime != sit_i->min_mtime)
 359                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 360                                 sit_i->max_mtime - sit_i->min_mtime);
 361
 362         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 363 }
 364
 365 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 366                         unsigned int segno, struct victim_sel_policy *p)
 367 {
 368         if (p->alloc_mode == SSR)
 369                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 370
 371         /* alloc_mode == LFS */
 372         if (p->gc_mode == GC_GREEDY)
 373                 return get_valid_blocks(sbi, segno, true);
 374         else if (p->gc_mode == GC_CB)
 375                 return get_cb_cost(sbi, segno);
 376
 377         f2fs_bug_on(sbi, 1);
 378         return 0;
 379 }
 380
 381 static unsigned int count_bits(const unsigned long *addr,
 382                                 unsigned int offset, unsigned int len)
 383 {
 384         unsigned int end = offset + len, sum = 0;
 385
 386         while (offset < end) {
 387                 if (test_bit(offset++, addr))
 388                         ++sum;
 389         }
 390         return sum;
 391 }
 392
 393 static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
 394                                 struct rb_root_cached *root)
 395 {
 396 #ifdef CONFIG_F2FS_CHECK_FS
 397         struct rb_node *cur = rb_first_cached(root), *next;
 398         struct victim_entry *cur_ve, *next_ve;
 399
 400         while (cur) {
 401                 next = rb_next(cur);
 402                 if (!next)
 403                         return true;
 404
 405                 cur_ve = rb_entry(cur, struct victim_entry, rb_node);
 406                 next_ve = rb_entry(next, struct victim_entry, rb_node);
 407
 408                 if (cur_ve->mtime > next_ve->mtime) {
 409                         f2fs_info(sbi, "broken victim_rbtree, "
 410                                 "cur_mtime(%llu) next_mtime(%llu)",
 411                                 cur_ve->mtime, next_ve->mtime);
 412                         return false;
 413                 }
 414                 cur = next;
 415         }
 416 #endif
 417         return true;
 418 }
 419
 420 static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
 421                                         unsigned long long mtime)
 422 {
 423         struct atgc_management *am = &sbi->am;
 424         struct rb_node *node = am->root.rb_root.rb_node;
 425         struct victim_entry *ve = NULL;
 426
 427         while (node) {
 428                 ve = rb_entry(node, struct victim_entry, rb_node);
 429
 430                 if (mtime < ve->mtime)
 431                         node = node->rb_left;
 432                 else
 433                         node = node->rb_right;
 434         }
 435         return ve;
 436 }
 437
 438 static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
 439                 unsigned long long mtime, unsigned int segno)
 440 {
 441         struct atgc_management *am = &sbi->am;
 442         struct victim_entry *ve;
 443
 444         ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS, true, NULL);
 445
 446         ve->mtime = mtime;
 447         ve->segno = segno;
 448
 449         list_add_tail(&ve->list, &am->victim_list);
 450         am->victim_count++;
 451
 452         return ve;
 453 }
 454
 455 static void __insert_victim_entry(struct f2fs_sb_info *sbi,
 456                                 unsigned long long mtime, unsigned int segno)
 457 {
 458         struct atgc_management *am = &sbi->am;
 459         struct rb_root_cached *root = &am->root;
 460         struct rb_node **p = &root->rb_root.rb_node;
 461         struct rb_node *parent = NULL;
 462         struct victim_entry *ve;
 463         bool left_most = true;
 464
 465         /* look up rb tree to find parent node */
 466         while (*p) {
 467                 parent = *p;
 468                 ve = rb_entry(parent, struct victim_entry, rb_node);
 469
 470                 if (mtime < ve->mtime) {
 471                         p = &(*p)->rb_left;
 472                 } else {
 473                         p = &(*p)->rb_right;
 474                         left_most = false;
 475                 }
 476         }
 477
 478         ve = __create_victim_entry(sbi, mtime, segno);
 479
 480         rb_link_node(&ve->rb_node, parent, p);
 481         rb_insert_color_cached(&ve->rb_node, root, left_most);
 482 }
 483
 484 static void add_victim_entry(struct f2fs_sb_info *sbi,
 485                                 struct victim_sel_policy *p, unsigned int segno)
 486 {
 487         struct sit_info *sit_i = SIT_I(sbi);
 488         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 489         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 490         unsigned long long mtime = 0;
 491         unsigned int i;
 492
 493         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 494                 if (p->gc_mode == GC_AT &&
 495                         get_valid_blocks(sbi, segno, true) == 0)
 496                         return;
 497         }
 498
 499         for (i = 0; i < SEGS_PER_SEC(sbi); i++)
 500                 mtime += get_seg_entry(sbi, start + i)->mtime;
 501         mtime = div_u64(mtime, SEGS_PER_SEC(sbi));
 502
 503         /* Handle if the system time has changed by the user */
 504         if (mtime < sit_i->min_mtime)
 505                 sit_i->min_mtime = mtime;
 506         if (mtime > sit_i->max_mtime)
 507                 sit_i->max_mtime = mtime;
 508         if (mtime < sit_i->dirty_min_mtime)
 509                 sit_i->dirty_min_mtime = mtime;
 510         if (mtime > sit_i->dirty_max_mtime)
 511                 sit_i->dirty_max_mtime = mtime;
 512
 513         /* don't choose young section as candidate */
 514         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 515                 return;
 516
 517         __insert_victim_entry(sbi, mtime, segno);
 518 }
 519
 520 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 521                                                 struct victim_sel_policy *p)
 522 {
 523         struct sit_info *sit_i = SIT_I(sbi);
 524         struct atgc_management *am = &sbi->am;
 525         struct rb_root_cached *root = &am->root;
 526         struct rb_node *node;
 527         struct victim_entry *ve;
 528         unsigned long long total_time;
 529         unsigned long long age, u, accu;
 530         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 531         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 532         unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
 533         unsigned int vblocks;
 534         unsigned int dirty_threshold = max(am->max_candidate_count,
 535                                         am->candidate_ratio *
 536                                         am->victim_count / 100);
 537         unsigned int age_weight = am->age_weight;
 538         unsigned int cost;
 539         unsigned int iter = 0;
 540
 541         if (max_mtime < min_mtime)
 542                 return;
 543
 544         max_mtime += 1;
 545         total_time = max_mtime - min_mtime;
 546
 547         accu = div64_u64(ULLONG_MAX, total_time);
 548         accu = min_t(unsigned long long, div_u64(accu, 100),
 549                                         DEFAULT_ACCURACY_CLASS);
 550
 551         node = rb_first_cached(root);
 552 next:
 553         ve = rb_entry_safe(node, struct victim_entry, rb_node);
 554         if (!ve)
 555                 return;
 556
 557         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 558                 goto skip;
 559
 560         /* age = 10000 * x% * 60 */
 561         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 562                                                                 age_weight;
 563
 564         vblocks = get_valid_blocks(sbi, ve->segno, true);
 565         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 566
 567         /* u = 10000 * x% * 40 */
 568         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 569                                                         (100 - age_weight);
 570
 571         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 572
 573         cost = UINT_MAX - (age + u);
 574         iter++;
 575
 576         if (cost < p->min_cost ||
 577                         (cost == p->min_cost && age > p->oldest_age)) {
 578                 p->min_cost = cost;
 579                 p->oldest_age = age;
 580                 p->min_segno = ve->segno;
 581         }
 582 skip:
 583         if (iter < dirty_threshold) {
 584                 node = rb_next(node);
 585                 goto next;
 586         }
 587 }
 588
 589 /*
 590  * select candidates around source section in range of
 591  * [target - dirty_threshold, target + dirty_threshold]
 592  */
 593 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 594                                                 struct victim_sel_policy *p)
 595 {
 596         struct sit_info *sit_i = SIT_I(sbi);
 597         struct atgc_management *am = &sbi->am;
 598         struct victim_entry *ve;
 599         unsigned long long age;
 600         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 601         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 602         unsigned int vblocks;
 603         unsigned int dirty_threshold = max(am->max_candidate_count,
 604                                         am->candidate_ratio *
 605                                         am->victim_count / 100);
 606         unsigned int cost, iter;
 607         int stage = 0;
 608
 609         if (max_mtime < min_mtime)
 610                 return;
 611         max_mtime += 1;
 612 next_stage:
 613         iter = 0;
 614         ve = __lookup_victim_entry(sbi, p->age);
 615 next_node:
 616         if (!ve) {
 617                 if (stage++ == 0)
 618                         goto next_stage;
 619                 return;
 620         }
 621
 622         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 623                 goto skip_node;
 624
 625         age = max_mtime - ve->mtime;
 626
 627         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 628         f2fs_bug_on(sbi, !vblocks);
 629
 630         /* rare case */
 631         if (vblocks == BLKS_PER_SEG(sbi))
 632                 goto skip_node;
 633
 634         iter++;
 635
 636         age = max_mtime - abs(p->age - age);
 637         cost = UINT_MAX - vblocks;
 638
 639         if (cost < p->min_cost ||
 640                         (cost == p->min_cost && age > p->oldest_age)) {
 641                 p->min_cost = cost;
 642                 p->oldest_age = age;
 643                 p->min_segno = ve->segno;
 644         }
 645 skip_node:
 646         if (iter < dirty_threshold) {
 647                 ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
 648                                         rb_next(&ve->rb_node),
 649                                         struct victim_entry, rb_node);
 650                 goto next_node;
 651         }
 652
 653         if (stage++ == 0)
 654                 goto next_stage;
 655 }
 656
 657 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 658                                                 struct victim_sel_policy *p)
 659 {
 660         f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
 661
 662         if (p->gc_mode == GC_AT)
 663                 atgc_lookup_victim(sbi, p);
 664         else if (p->alloc_mode == AT_SSR)
 665                 atssr_lookup_victim(sbi, p);
 666         else
 667                 f2fs_bug_on(sbi, 1);
 668 }
 669
 670 static void release_victim_entry(struct f2fs_sb_info *sbi)
 671 {
 672         struct atgc_management *am = &sbi->am;
 673         struct victim_entry *ve, *tmp;
 674
 675         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 676                 list_del(&ve->list);
 677                 kmem_cache_free(victim_entry_slab, ve);
 678                 am->victim_count--;
 679         }
 680
 681         am->root = RB_ROOT_CACHED;
 682
 683         f2fs_bug_on(sbi, am->victim_count);
 684         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 685 }
 686
 687 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
 688 {
 689         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 690         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 691
 692         if (!dirty_i->enable_pin_section)
 693                 return false;
 694         if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
 695                 dirty_i->pinned_secmap_cnt++;
 696         return true;
 697 }
 698
 699 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
 700 {
 701         return dirty_i->pinned_secmap_cnt;
 702 }
 703
 704 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
 705                                                 unsigned int secno)
 706 {
 707         return dirty_i->enable_pin_section &&
 708                 f2fs_pinned_section_exists(dirty_i) &&
 709                 test_bit(secno, dirty_i->pinned_secmap);
 710 }
 711
 712 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
 713 {
 714         unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 715
 716         if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
 717                 memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
 718                 DIRTY_I(sbi)->pinned_secmap_cnt = 0;
 719         }
 720         DIRTY_I(sbi)->enable_pin_section = enable;
 721 }
 722
 723 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
 724                                                         unsigned int segno)
 725 {
 726         if (!f2fs_is_pinned_file(inode))
 727                 return 0;
 728         if (gc_type != FG_GC)
 729                 return -EBUSY;
 730         if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
 731                 f2fs_pin_file_control(inode, true);
 732         return -EAGAIN;
 733 }
 734
 735 /*
 736  * This function is called from two paths.
 737  * One is garbage collection and the other is SSR segment selection.
 738  * When it is called during GC, it just gets a victim segment
 739  * and it does not remove it from dirty seglist.
 740  * When it is called from SSR segment selection, it finds a segment
 741  * which has minimum valid blocks and removes it from dirty seglist.
 742  */
 743 int f2fs_get_victim(struct f2fs_sb_info *sbi, unsigned int *result,
 744                         int gc_type, int type, char alloc_mode,
 745                         unsigned long long age)
 746 {
 747         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 748         struct sit_info *sm = SIT_I(sbi);
 749         struct victim_sel_policy p;
 750         unsigned int secno, last_victim;
 751         unsigned int last_segment;
 752         unsigned int nsearched;
 753         bool is_atgc;
 754         int ret = 0;
 755
 756         mutex_lock(&dirty_i->seglist_lock);
 757         last_segment = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
 758
 759         p.alloc_mode = alloc_mode;
 760         p.age = age;
 761         p.age_threshold = sbi->am.age_threshold;
 762
 763 retry:
 764         select_policy(sbi, gc_type, type, &p);
 765         p.min_segno = NULL_SEGNO;
 766         p.oldest_age = 0;
 767         p.min_cost = get_max_cost(sbi, &p);
 768
 769         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 770         nsearched = 0;
 771
 772         if (is_atgc)
 773                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 774
 775         if (*result != NULL_SEGNO) {
 776                 if (!get_valid_blocks(sbi, *result, false)) {
 777                         ret = -ENODATA;
 778                         goto out;
 779                 }
 780
 781                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 782                         ret = -EBUSY;
 783                 else
 784                         p.min_segno = *result;
 785                 goto out;
 786         }
 787
 788         ret = -ENODATA;
 789         if (p.max_search == 0)
 790                 goto out;
 791
 792         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 793                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 794                         p.min_segno = sbi->next_victim_seg[BG_GC];
 795                         *result = p.min_segno;
 796                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 797                         goto got_result;
 798                 }
 799                 if (gc_type == FG_GC &&
 800                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 801                         p.min_segno = sbi->next_victim_seg[FG_GC];
 802                         *result = p.min_segno;
 803                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 804                         goto got_result;
 805                 }
 806         }
 807
 808         last_victim = sm->last_victim[p.gc_mode];
 809         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 810                 p.min_segno = check_bg_victims(sbi);
 811                 if (p.min_segno != NULL_SEGNO)
 812                         goto got_it;
 813         }
 814
 815         while (1) {
 816                 unsigned long cost, *dirty_bitmap;
 817                 unsigned int unit_no, segno;
 818
 819                 dirty_bitmap = p.dirty_bitmap;
 820                 unit_no = find_next_bit(dirty_bitmap,
 821                                 last_segment / p.ofs_unit,
 822                                 p.offset / p.ofs_unit);
 823                 segno = unit_no * p.ofs_unit;
 824                 if (segno >= last_segment) {
 825                         if (sm->last_victim[p.gc_mode]) {
 826                                 last_segment =
 827                                         sm->last_victim[p.gc_mode];
 828                                 sm->last_victim[p.gc_mode] = 0;
 829                                 p.offset = 0;
 830                                 continue;
 831                         }
 832                         break;
 833                 }
 834
 835                 p.offset = segno + p.ofs_unit;
 836                 nsearched++;
 837
 838 #ifdef CONFIG_F2FS_CHECK_FS
 839                 /*
 840                  * skip selecting the invalid segno (that is failed due to block
 841                  * validity check failure during GC) to avoid endless GC loop in
 842                  * such cases.
 843                  */
 844                 if (test_bit(segno, sm->invalid_segmap))
 845                         goto next;
 846 #endif
 847
 848                 secno = GET_SEC_FROM_SEG(sbi, segno);
 849
 850                 if (sec_usage_check(sbi, secno))
 851                         goto next;
 852
 853                 /* Don't touch checkpointed data */
 854                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 855                         if (p.alloc_mode == LFS) {
 856                                 /*
 857                                  * LFS is set to find source section during GC.
 858                                  * The victim should have no checkpointed data.
 859                                  */
 860                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 861                                         goto next;
 862                         } else {
 863                                 /*
 864                                  * SSR | AT_SSR are set to find target segment
 865                                  * for writes which can be full by checkpointed
 866                                  * and newly written blocks.
 867                                  */
 868                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 869                                         goto next;
 870                         }
 871                 }
 872
 873                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 874                         goto next;
 875
 876                 if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
 877                         goto next;
 878
 879                 if (is_atgc) {
 880                         add_victim_entry(sbi, &p, segno);
 881                         goto next;
 882                 }
 883
 884                 cost = get_gc_cost(sbi, segno, &p);
 885
 886                 if (p.min_cost > cost) {
 887                         p.min_segno = segno;
 888                         p.min_cost = cost;
 889                 }
 890 next:
 891                 if (nsearched >= p.max_search) {
 892                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 893                                 sm->last_victim[p.gc_mode] =
 894                                         last_victim + p.ofs_unit;
 895                         else
 896                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 897                         sm->last_victim[p.gc_mode] %=
 898                                 (MAIN_SECS(sbi) * SEGS_PER_SEC(sbi));
 899                         break;
 900                 }
 901         }
 902
 903         /* get victim for GC_AT/AT_SSR */
 904         if (is_atgc) {
 905                 lookup_victim_by_age(sbi, &p);
 906                 release_victim_entry(sbi);
 907         }
 908
 909         if (is_atgc && p.min_segno == NULL_SEGNO &&
 910                         sm->elapsed_time < p.age_threshold) {
 911                 p.age_threshold = 0;
 912                 goto retry;
 913         }
 914
 915         if (p.min_segno != NULL_SEGNO) {
 916 got_it:
 917                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 918 got_result:
 919                 if (p.alloc_mode == LFS) {
 920                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 921                         if (gc_type == FG_GC)
 922                                 sbi->cur_victim_sec = secno;
 923                         else
 924                                 set_bit(secno, dirty_i->victim_secmap);
 925                 }
 926                 ret = 0;
 927
 928         }
 929 out:
 930         if (p.min_segno != NULL_SEGNO)
 931                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 932                                 sbi->cur_victim_sec,
 933                                 prefree_segments(sbi), free_segments(sbi));
 934         mutex_unlock(&dirty_i->seglist_lock);
 935
 936         return ret;
 937 }
 938
 939 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 940 {
 941         struct inode_entry *ie;
 942
 943         ie = radix_tree_lookup(&gc_list->iroot, ino);
 944         if (ie)
 945                 return ie->inode;
 946         return NULL;
 947 }
 948
 949 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 950 {
 951         struct inode_entry *new_ie;
 952
 953         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 954                 iput(inode);
 955                 return;
 956         }
 957         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 958                                         GFP_NOFS, true, NULL);
 959         new_ie->inode = inode;
 960
 961         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 962         list_add_tail(&new_ie->list, &gc_list->ilist);
 963 }
 964
 965 static void put_gc_inode(struct gc_inode_list *gc_list)
 966 {
 967         struct inode_entry *ie, *next_ie;
 968
 969         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 970                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 971                 iput(ie->inode);
 972                 list_del(&ie->list);
 973                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 974         }
 975 }
 976
 977 static int check_valid_map(struct f2fs_sb_info *sbi,
 978                                 unsigned int segno, int offset)
 979 {
 980         struct sit_info *sit_i = SIT_I(sbi);
 981         struct seg_entry *sentry;
 982         int ret;
 983
 984         down_read(&sit_i->sentry_lock);
 985         sentry = get_seg_entry(sbi, segno);
 986         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 987         up_read(&sit_i->sentry_lock);
 988         return ret;
 989 }
 990
 991 /*
 992  * This function compares node address got in summary with that in NAT.
 993  * On validity, copy that node with cold status, otherwise (invalid node)
 994  * ignore that.
 995  */
 996 static int gc_node_segment(struct f2fs_sb_info *sbi,
 997                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 998 {
 999         struct f2fs_summary *entry;
1000         block_t start_addr;
1001         int off;
1002         int phase = 0;
1003         bool fggc = (gc_type == FG_GC);
1004         int submitted = 0;
1005         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1006
1007         start_addr = START_BLOCK(sbi, segno);
1008
1009 next_step:
1010         entry = sum;
1011
1012         if (fggc && phase == 2)
1013                 atomic_inc(&sbi->wb_sync_req[NODE]);
1014
1015         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1016                 nid_t nid = le32_to_cpu(entry->nid);
1017                 struct page *node_page;
1018                 struct node_info ni;
1019                 int err;
1020
1021                 /* stop BG_GC if there is not enough free sections. */
1022                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
1023                         return submitted;
1024
1025                 if (check_valid_map(sbi, segno, off) == 0)
1026                         continue;
1027
1028                 if (phase == 0) {
1029                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1030                                                         META_NAT, true);
1031                         continue;
1032                 }
1033
1034                 if (phase == 1) {
1035                         f2fs_ra_node_page(sbi, nid);
1036                         continue;
1037                 }
1038
1039                 /* phase == 2 */
1040                 node_page = f2fs_get_node_page(sbi, nid);
1041                 if (IS_ERR(node_page))
1042                         continue;
1043
1044                 /* block may become invalid during f2fs_get_node_page */
1045                 if (check_valid_map(sbi, segno, off) == 0) {
1046                         f2fs_put_page(node_page, 1);
1047                         continue;
1048                 }
1049
1050                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1051                         f2fs_put_page(node_page, 1);
1052                         continue;
1053                 }
1054
1055                 if (ni.blk_addr != start_addr + off) {
1056                         f2fs_put_page(node_page, 1);
1057                         continue;
1058                 }
1059
1060                 err = f2fs_move_node_page(node_page, gc_type);
1061                 if (!err && gc_type == FG_GC)
1062                         submitted++;
1063                 stat_inc_node_blk_count(sbi, 1, gc_type);
1064         }
1065
1066         if (++phase < 3)
1067                 goto next_step;
1068
1069         if (fggc)
1070                 atomic_dec(&sbi->wb_sync_req[NODE]);
1071         return submitted;
1072 }
1073
1074 /*
1075  * Calculate start block index indicating the given node offset.
1076  * Be careful, caller should give this node offset only indicating direct node
1077  * blocks. If any node offsets, which point the other types of node blocks such
1078  * as indirect or double indirect node blocks, are given, it must be a caller's
1079  * bug.
1080  */
1081 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1082 {
1083         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1084         unsigned int bidx;
1085
1086         if (node_ofs == 0)
1087                 return 0;
1088
1089         if (node_ofs <= 2) {
1090                 bidx = node_ofs - 1;
1091         } else if (node_ofs <= indirect_blks) {
1092                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1093
1094                 bidx = node_ofs - 2 - dec;
1095         } else {
1096                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1097
1098                 bidx = node_ofs - 5 - dec;
1099         }
1100         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1101 }
1102
1103 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1104                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1105 {
1106         struct page *node_page;
1107         nid_t nid;
1108         unsigned int ofs_in_node, max_addrs, base;
1109         block_t source_blkaddr;
1110
1111         nid = le32_to_cpu(sum->nid);
1112         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1113
1114         node_page = f2fs_get_node_page(sbi, nid);
1115         if (IS_ERR(node_page))
1116                 return false;
1117
1118         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1119                 f2fs_put_page(node_page, 1);
1120                 return false;
1121         }
1122
1123         if (sum->version != dni->version) {
1124                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1125                           __func__);
1126                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1127         }
1128
1129         if (f2fs_check_nid_range(sbi, dni->ino)) {
1130                 f2fs_put_page(node_page, 1);
1131                 return false;
1132         }
1133
1134         if (IS_INODE(node_page)) {
1135                 base = offset_in_addr(F2FS_INODE(node_page));
1136                 max_addrs = DEF_ADDRS_PER_INODE;
1137         } else {
1138                 base = 0;
1139                 max_addrs = DEF_ADDRS_PER_BLOCK;
1140         }
1141
1142         if (base + ofs_in_node >= max_addrs) {
1143                 f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1144                         base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1145                 f2fs_put_page(node_page, 1);
1146                 return false;
1147         }
1148
1149         *nofs = ofs_of_node(node_page);
1150         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1151         f2fs_put_page(node_page, 1);
1152
1153         if (source_blkaddr != blkaddr) {
1154 #ifdef CONFIG_F2FS_CHECK_FS
1155                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1156                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1157
1158                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1159                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1160                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1161                                          blkaddr, source_blkaddr, segno);
1162                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1163                         }
1164                 }
1165 #endif
1166                 return false;
1167         }
1168         return true;
1169 }
1170
1171 static int ra_data_block(struct inode *inode, pgoff_t index)
1172 {
1173         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1174         struct address_space *mapping = inode->i_mapping;
1175         struct dnode_of_data dn;
1176         struct page *page;
1177         struct f2fs_io_info fio = {
1178                 .sbi = sbi,
1179                 .ino = inode->i_ino,
1180                 .type = DATA,
1181                 .temp = COLD,
1182                 .op = REQ_OP_READ,
1183                 .op_flags = 0,
1184                 .encrypted_page = NULL,
1185                 .in_list = 0,
1186         };
1187         int err;
1188
1189         page = f2fs_grab_cache_page(mapping, index, true);
1190         if (!page)
1191                 return -ENOMEM;
1192
1193         if (f2fs_lookup_read_extent_cache_block(inode, index,
1194                                                 &dn.data_blkaddr)) {
1195                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1196                                                 DATA_GENERIC_ENHANCE_READ))) {
1197                         err = -EFSCORRUPTED;
1198                         goto put_page;
1199                 }
1200                 goto got_it;
1201         }
1202
1203         set_new_dnode(&dn, inode, NULL, NULL, 0);
1204         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1205         if (err)
1206                 goto put_page;
1207         f2fs_put_dnode(&dn);
1208
1209         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1210                 err = -ENOENT;
1211                 goto put_page;
1212         }
1213         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1214                                                 DATA_GENERIC_ENHANCE))) {
1215                 err = -EFSCORRUPTED;
1216                 goto put_page;
1217         }
1218 got_it:
1219         /* read page */
1220         fio.page = page;
1221         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1222
1223         /*
1224          * don't cache encrypted data into meta inode until previous dirty
1225          * data were writebacked to avoid racing between GC and flush.
1226          */
1227         f2fs_wait_on_page_writeback(page, DATA, true, true);
1228
1229         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1230
1231         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1232                                         dn.data_blkaddr,
1233                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1234         if (!fio.encrypted_page) {
1235                 err = -ENOMEM;
1236                 goto put_page;
1237         }
1238
1239         err = f2fs_submit_page_bio(&fio);
1240         if (err)
1241                 goto put_encrypted_page;
1242         f2fs_put_page(fio.encrypted_page, 0);
1243         f2fs_put_page(page, 1);
1244
1245         f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1246         f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1247
1248         return 0;
1249 put_encrypted_page:
1250         f2fs_put_page(fio.encrypted_page, 1);
1251 put_page:
1252         f2fs_put_page(page, 1);
1253         return err;
1254 }
1255
1256 /*
1257  * Move data block via META_MAPPING while keeping locked data page.
1258  * This can be used to move blocks, aka LBAs, directly on disk.
1259  */
1260 static int move_data_block(struct inode *inode, block_t bidx,
1261                                 int gc_type, unsigned int segno, int off)
1262 {
1263         struct f2fs_io_info fio = {
1264                 .sbi = F2FS_I_SB(inode),
1265                 .ino = inode->i_ino,
1266                 .type = DATA,
1267                 .temp = COLD,
1268                 .op = REQ_OP_READ,
1269                 .op_flags = 0,
1270                 .encrypted_page = NULL,
1271                 .in_list = 0,
1272         };
1273         struct dnode_of_data dn;
1274         struct f2fs_summary sum;
1275         struct node_info ni;
1276         struct page *page, *mpage;
1277         block_t newaddr;
1278         int err = 0;
1279         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1280         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1281                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1282                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1283
1284         /* do not read out */
1285         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1286         if (!page)
1287                 return -ENOMEM;
1288
1289         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1290                 err = -ENOENT;
1291                 goto out;
1292         }
1293
1294         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1295         if (err)
1296                 goto out;
1297
1298         set_new_dnode(&dn, inode, NULL, NULL, 0);
1299         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1300         if (err)
1301                 goto out;
1302
1303         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1304                 ClearPageUptodate(page);
1305                 err = -ENOENT;
1306                 goto put_out;
1307         }
1308
1309         /*
1310          * don't cache encrypted data into meta inode until previous dirty
1311          * data were writebacked to avoid racing between GC and flush.
1312          */
1313         f2fs_wait_on_page_writeback(page, DATA, true, true);
1314
1315         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1316
1317         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1318         if (err)
1319                 goto put_out;
1320
1321         /* read page */
1322         fio.page = page;
1323         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1324
1325         if (lfs_mode)
1326                 f2fs_down_write(&fio.sbi->io_order_lock);
1327
1328         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1329                                         fio.old_blkaddr, false);
1330         if (!mpage) {
1331                 err = -ENOMEM;
1332                 goto up_out;
1333         }
1334
1335         fio.encrypted_page = mpage;
1336
1337         /* read source block in mpage */
1338         if (!PageUptodate(mpage)) {
1339                 err = f2fs_submit_page_bio(&fio);
1340                 if (err) {
1341                         f2fs_put_page(mpage, 1);
1342                         goto up_out;
1343                 }
1344
1345                 f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1346                                                         F2FS_BLKSIZE);
1347                 f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1348                                                         F2FS_BLKSIZE);
1349
1350                 lock_page(mpage);
1351                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1352                                                 !PageUptodate(mpage))) {
1353                         err = -EIO;
1354                         f2fs_put_page(mpage, 1);
1355                         goto up_out;
1356                 }
1357         }
1358
1359         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1360
1361         /* allocate block address */
1362         err = f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1363                                 &sum, type, NULL);
1364         if (err) {
1365                 f2fs_put_page(mpage, 1);
1366                 /* filesystem should shutdown, no need to recovery block */
1367                 goto up_out;
1368         }
1369
1370         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1371                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1372         if (!fio.encrypted_page) {
1373                 err = -ENOMEM;
1374                 f2fs_put_page(mpage, 1);
1375                 goto recover_block;
1376         }
1377
1378         /* write target block */
1379         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1380         memcpy(page_address(fio.encrypted_page),
1381                                 page_address(mpage), PAGE_SIZE);
1382         f2fs_put_page(mpage, 1);
1383
1384         f2fs_invalidate_internal_cache(fio.sbi, fio.old_blkaddr);
1385
1386         set_page_dirty(fio.encrypted_page);
1387         if (clear_page_dirty_for_io(fio.encrypted_page))
1388                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1389
1390         set_page_writeback(fio.encrypted_page);
1391
1392         fio.op = REQ_OP_WRITE;
1393         fio.op_flags = REQ_SYNC;
1394         fio.new_blkaddr = newaddr;
1395         f2fs_submit_page_write(&fio);
1396
1397         f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1398
1399         f2fs_update_data_blkaddr(&dn, newaddr);
1400         set_inode_flag(inode, FI_APPEND_WRITE);
1401
1402         f2fs_put_page(fio.encrypted_page, 1);
1403 recover_block:
1404         if (err)
1405                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1406                                                         true, true, true);
1407 up_out:
1408         if (lfs_mode)
1409                 f2fs_up_write(&fio.sbi->io_order_lock);
1410 put_out:
1411         f2fs_put_dnode(&dn);
1412 out:
1413         f2fs_put_page(page, 1);
1414         return err;
1415 }
1416
1417 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1418                                                         unsigned int segno, int off)
1419 {
1420         struct page *page;
1421         int err = 0;
1422
1423         page = f2fs_get_lock_data_page(inode, bidx, true);
1424         if (IS_ERR(page))
1425                 return PTR_ERR(page);
1426
1427         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1428                 err = -ENOENT;
1429                 goto out;
1430         }
1431
1432         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1433         if (err)
1434                 goto out;
1435
1436         if (gc_type == BG_GC) {
1437                 if (PageWriteback(page)) {
1438                         err = -EAGAIN;
1439                         goto out;
1440                 }
1441                 set_page_dirty(page);
1442                 set_page_private_gcing(page);
1443         } else {
1444                 struct f2fs_io_info fio = {
1445                         .sbi = F2FS_I_SB(inode),
1446                         .ino = inode->i_ino,
1447                         .type = DATA,
1448                         .temp = COLD,
1449                         .op = REQ_OP_WRITE,
1450                         .op_flags = REQ_SYNC,
1451                         .old_blkaddr = NULL_ADDR,
1452                         .page = page,
1453                         .encrypted_page = NULL,
1454                         .need_lock = LOCK_REQ,
1455                         .io_type = FS_GC_DATA_IO,
1456                 };
1457                 bool is_dirty = PageDirty(page);
1458
1459 retry:
1460                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1461
1462                 set_page_dirty(page);
1463                 if (clear_page_dirty_for_io(page)) {
1464                         inode_dec_dirty_pages(inode);
1465                         f2fs_remove_dirty_inode(inode);
1466                 }
1467
1468                 set_page_private_gcing(page);
1469
1470                 err = f2fs_do_write_data_page(&fio);
1471                 if (err) {
1472                         clear_page_private_gcing(page);
1473                         if (err == -ENOMEM) {
1474                                 memalloc_retry_wait(GFP_NOFS);
1475                                 goto retry;
1476                         }
1477                         if (is_dirty)
1478                                 set_page_dirty(page);
1479                 }
1480         }
1481 out:
1482         f2fs_put_page(page, 1);
1483         return err;
1484 }
1485
1486 /*
1487  * This function tries to get parent node of victim data block, and identifies
1488  * data block validity. If the block is valid, copy that with cold status and
1489  * modify parent node.
1490  * If the parent node is not valid or the data block address is different,
1491  * the victim data block is ignored.
1492  */
1493 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1494                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1495                 bool force_migrate)
1496 {
1497         struct super_block *sb = sbi->sb;
1498         struct f2fs_summary *entry;
1499         block_t start_addr;
1500         int off;
1501         int phase = 0;
1502         int submitted = 0;
1503         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1504
1505         start_addr = START_BLOCK(sbi, segno);
1506
1507 next_step:
1508         entry = sum;
1509
1510         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1511                 struct page *data_page;
1512                 struct inode *inode;
1513                 struct node_info dni; /* dnode info for the data */
1514                 unsigned int ofs_in_node, nofs;
1515                 block_t start_bidx;
1516                 nid_t nid = le32_to_cpu(entry->nid);
1517
1518                 /*
1519                  * stop BG_GC if there is not enough free sections.
1520                  * Or, stop GC if the segment becomes fully valid caused by
1521                  * race condition along with SSR block allocation.
1522                  */
1523                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1524                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1525                                                         CAP_BLKS_PER_SEC(sbi)))
1526                         return submitted;
1527
1528                 if (check_valid_map(sbi, segno, off) == 0)
1529                         continue;
1530
1531                 if (phase == 0) {
1532                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1533                                                         META_NAT, true);
1534                         continue;
1535                 }
1536
1537                 if (phase == 1) {
1538                         f2fs_ra_node_page(sbi, nid);
1539                         continue;
1540                 }
1541
1542                 /* Get an inode by ino with checking validity */
1543                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1544                         continue;
1545
1546                 if (phase == 2) {
1547                         f2fs_ra_node_page(sbi, dni.ino);
1548                         continue;
1549                 }
1550
1551                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1552
1553                 if (phase == 3) {
1554                         int err;
1555
1556                         inode = f2fs_iget(sb, dni.ino);
1557                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1558                                         special_file(inode->i_mode))
1559                                 continue;
1560
1561                         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1562                         if (err == -EAGAIN) {
1563                                 iput(inode);
1564                                 return submitted;
1565                         }
1566
1567                         if (!f2fs_down_write_trylock(
1568                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1569                                 iput(inode);
1570                                 sbi->skipped_gc_rwsem++;
1571                                 continue;
1572                         }
1573
1574                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1575                                                                 ofs_in_node;
1576
1577                         if (f2fs_post_read_required(inode)) {
1578                                 int err = ra_data_block(inode, start_bidx);
1579
1580                                 f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1581                                 if (err) {
1582                                         iput(inode);
1583                                         continue;
1584                                 }
1585                                 add_gc_inode(gc_list, inode);
1586                                 continue;
1587                         }
1588
1589                         data_page = f2fs_get_read_data_page(inode, start_bidx,
1590                                                         REQ_RAHEAD, true, NULL);
1591                         f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1592                         if (IS_ERR(data_page)) {
1593                                 iput(inode);
1594                                 continue;
1595                         }
1596
1597                         f2fs_put_page(data_page, 0);
1598                         add_gc_inode(gc_list, inode);
1599                         continue;
1600                 }
1601
1602                 /* phase 4 */
1603                 inode = find_gc_inode(gc_list, dni.ino);
1604                 if (inode) {
1605                         struct f2fs_inode_info *fi = F2FS_I(inode);
1606                         bool locked = false;
1607                         int err;
1608
1609                         if (S_ISREG(inode->i_mode)) {
1610                                 if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[WRITE])) {
1611                                         sbi->skipped_gc_rwsem++;
1612                                         continue;
1613                                 }
1614                                 if (!f2fs_down_write_trylock(
1615                                                 &fi->i_gc_rwsem[READ])) {
1616                                         sbi->skipped_gc_rwsem++;
1617                                         f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1618                                         continue;
1619                                 }
1620                                 locked = true;
1621
1622                                 /* wait for all inflight aio data */
1623                                 inode_dio_wait(inode);
1624                         }
1625
1626                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1627                                                                 + ofs_in_node;
1628                         if (f2fs_post_read_required(inode))
1629                                 err = move_data_block(inode, start_bidx,
1630                                                         gc_type, segno, off);
1631                         else
1632                                 err = move_data_page(inode, start_bidx, gc_type,
1633                                                                 segno, off);
1634
1635                         if (!err && (gc_type == FG_GC ||
1636                                         f2fs_post_read_required(inode)))
1637                                 submitted++;
1638
1639                         if (locked) {
1640                                 f2fs_up_write(&fi->i_gc_rwsem[READ]);
1641                                 f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1642                         }
1643
1644                         stat_inc_data_blk_count(sbi, 1, gc_type);
1645                 }
1646         }
1647
1648         if (++phase < 5)
1649                 goto next_step;
1650
1651         return submitted;
1652 }
1653
1654 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1655                         int gc_type)
1656 {
1657         struct sit_info *sit_i = SIT_I(sbi);
1658         int ret;
1659
1660         down_write(&sit_i->sentry_lock);
1661         ret = f2fs_get_victim(sbi, victim, gc_type, NO_CHECK_TYPE, LFS, 0);
1662         up_write(&sit_i->sentry_lock);
1663         return ret;
1664 }
1665
1666 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1667                                 unsigned int start_segno,
1668                                 struct gc_inode_list *gc_list, int gc_type,
1669                                 bool force_migrate)
1670 {
1671         struct page *sum_page;
1672         struct f2fs_summary_block *sum;
1673         struct blk_plug plug;
1674         unsigned int segno = start_segno;
1675         unsigned int end_segno = start_segno + SEGS_PER_SEC(sbi);
1676         int seg_freed = 0, migrated = 0;
1677         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1678                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1679         unsigned char data_type = (type == SUM_TYPE_DATA) ? DATA : NODE;
1680         int submitted = 0;
1681
1682         if (__is_large_section(sbi))
1683                 end_segno = rounddown(end_segno, SEGS_PER_SEC(sbi));
1684
1685         /*
1686          * zone-capacity can be less than zone-size in zoned devices,
1687          * resulting in less than expected usable segments in the zone,
1688          * calculate the end segno in the zone which can be garbage collected
1689          */
1690         if (f2fs_sb_has_blkzoned(sbi))
1691                 end_segno -= SEGS_PER_SEC(sbi) -
1692                                         f2fs_usable_segs_in_sec(sbi, segno);
1693
1694         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1695
1696         /* readahead multi ssa blocks those have contiguous address */
1697         if (__is_large_section(sbi))
1698                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1699                                         end_segno - segno, META_SSA, true);
1700
1701         /* reference all summary page */
1702         while (segno < end_segno) {
1703                 sum_page = f2fs_get_sum_page(sbi, segno++);
1704                 if (IS_ERR(sum_page)) {
1705                         int err = PTR_ERR(sum_page);
1706
1707                         end_segno = segno - 1;
1708                         for (segno = start_segno; segno < end_segno; segno++) {
1709                                 sum_page = find_get_page(META_MAPPING(sbi),
1710                                                 GET_SUM_BLOCK(sbi, segno));
1711                                 f2fs_put_page(sum_page, 0);
1712                                 f2fs_put_page(sum_page, 0);
1713                         }
1714                         return err;
1715                 }
1716                 unlock_page(sum_page);
1717         }
1718
1719         blk_start_plug(&plug);
1720
1721         for (segno = start_segno; segno < end_segno; segno++) {
1722
1723                 /* find segment summary of victim */
1724                 sum_page = find_get_page(META_MAPPING(sbi),
1725                                         GET_SUM_BLOCK(sbi, segno));
1726                 f2fs_put_page(sum_page, 0);
1727
1728                 if (get_valid_blocks(sbi, segno, false) == 0)
1729                         goto freed;
1730                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1731                                 migrated >= sbi->migration_granularity)
1732                         goto skip;
1733                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1734                         goto skip;
1735
1736                 sum = page_address(sum_page);
1737                 if (type != GET_SUM_TYPE((&sum->footer))) {
1738                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1739                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1740                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1741                         f2fs_stop_checkpoint(sbi, false,
1742                                 STOP_CP_REASON_CORRUPTED_SUMMARY);
1743                         goto skip;
1744                 }
1745
1746                 /*
1747                  * this is to avoid deadlock:
1748                  * - lock_page(sum_page)         - f2fs_replace_block
1749                  *  - check_valid_map()            - down_write(sentry_lock)
1750                  *   - down_read(sentry_lock)     - change_curseg()
1751                  *                                  - lock_page(sum_page)
1752                  */
1753                 if (type == SUM_TYPE_NODE)
1754                         submitted += gc_node_segment(sbi, sum->entries, segno,
1755                                                                 gc_type);
1756                 else
1757                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1758                                                         segno, gc_type,
1759                                                         force_migrate);
1760
1761                 stat_inc_gc_seg_count(sbi, data_type, gc_type);
1762                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1763                 migrated++;
1764
1765 freed:
1766                 if (gc_type == FG_GC &&
1767                                 get_valid_blocks(sbi, segno, false) == 0)
1768                         seg_freed++;
1769
1770                 if (__is_large_section(sbi))
1771                         sbi->next_victim_seg[gc_type] =
1772                                 (segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
1773 skip:
1774                 f2fs_put_page(sum_page, 0);
1775         }
1776
1777         if (submitted)
1778                 f2fs_submit_merged_write(sbi, data_type);
1779
1780         blk_finish_plug(&plug);
1781
1782         if (migrated)
1783                 stat_inc_gc_sec_count(sbi, data_type, gc_type);
1784
1785         return seg_freed;
1786 }
1787
1788 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1789 {
1790         int gc_type = gc_control->init_gc_type;
1791         unsigned int segno = gc_control->victim_segno;
1792         int sec_freed = 0, seg_freed = 0, total_freed = 0, total_sec_freed = 0;
1793         int ret = 0;
1794         struct cp_control cpc;
1795         struct gc_inode_list gc_list = {
1796                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1797                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1798         };
1799         unsigned int skipped_round = 0, round = 0;
1800         unsigned int upper_secs;
1801
1802         trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1803                                 gc_control->nr_free_secs,
1804                                 get_pages(sbi, F2FS_DIRTY_NODES),
1805                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1806                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1807                                 free_sections(sbi),
1808                                 free_segments(sbi),
1809                                 reserved_segments(sbi),
1810                                 prefree_segments(sbi));
1811
1812         cpc.reason = __get_cp_reason(sbi);
1813 gc_more:
1814         sbi->skipped_gc_rwsem = 0;
1815         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1816                 ret = -EINVAL;
1817                 goto stop;
1818         }
1819         if (unlikely(f2fs_cp_error(sbi))) {
1820                 ret = -EIO;
1821                 goto stop;
1822         }
1823
1824         /* Let's run FG_GC, if we don't have enough space. */
1825         if (has_not_enough_free_secs(sbi, 0, 0)) {
1826                 gc_type = FG_GC;
1827
1828                 /*
1829                  * For example, if there are many prefree_segments below given
1830                  * threshold, we can make them free by checkpoint. Then, we
1831                  * secure free segments which doesn't need fggc any more.
1832                  */
1833                 if (prefree_segments(sbi)) {
1834                         stat_inc_cp_call_count(sbi, TOTAL_CALL);
1835                         ret = f2fs_write_checkpoint(sbi, &cpc);
1836                         if (ret)
1837                                 goto stop;
1838                         /* Reset due to checkpoint */
1839                         sec_freed = 0;
1840                 }
1841         }
1842
1843         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1844         if (gc_type == BG_GC && gc_control->no_bg_gc) {
1845                 ret = -EINVAL;
1846                 goto stop;
1847         }
1848 retry:
1849         ret = __get_victim(sbi, &segno, gc_type);
1850         if (ret) {
1851                 /* allow to search victim from sections has pinned data */
1852                 if (ret == -ENODATA && gc_type == FG_GC &&
1853                                 f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1854                         f2fs_unpin_all_sections(sbi, false);
1855                         goto retry;
1856                 }
1857                 goto stop;
1858         }
1859
1860         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1861                                 gc_control->should_migrate_blocks);
1862         if (seg_freed < 0)
1863                 goto stop;
1864
1865         total_freed += seg_freed;
1866
1867         if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno)) {
1868                 sec_freed++;
1869                 total_sec_freed++;
1870         }
1871
1872         if (gc_type == FG_GC) {
1873                 sbi->cur_victim_sec = NULL_SEGNO;
1874
1875                 if (has_enough_free_secs(sbi, sec_freed, 0)) {
1876                         if (!gc_control->no_bg_gc &&
1877                             total_sec_freed < gc_control->nr_free_secs)
1878                                 goto go_gc_more;
1879                         goto stop;
1880                 }
1881                 if (sbi->skipped_gc_rwsem)
1882                         skipped_round++;
1883                 round++;
1884                 if (skipped_round > MAX_SKIP_GC_COUNT &&
1885                                 skipped_round * 2 >= round) {
1886                         stat_inc_cp_call_count(sbi, TOTAL_CALL);
1887                         ret = f2fs_write_checkpoint(sbi, &cpc);
1888                         goto stop;
1889                 }
1890         } else if (has_enough_free_secs(sbi, 0, 0)) {
1891                 goto stop;
1892         }
1893
1894         __get_secs_required(sbi, NULL, &upper_secs, NULL);
1895
1896         /*
1897          * Write checkpoint to reclaim prefree segments.
1898          * We need more three extra sections for writer's data/node/dentry.
1899          */
1900         if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
1901                                 prefree_segments(sbi)) {
1902                 stat_inc_cp_call_count(sbi, TOTAL_CALL);
1903                 ret = f2fs_write_checkpoint(sbi, &cpc);
1904                 if (ret)
1905                         goto stop;
1906                 /* Reset due to checkpoint */
1907                 sec_freed = 0;
1908         }
1909 go_gc_more:
1910         segno = NULL_SEGNO;
1911         goto gc_more;
1912
1913 stop:
1914         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1915         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1916
1917         if (gc_type == FG_GC)
1918                 f2fs_unpin_all_sections(sbi, true);
1919
1920         trace_f2fs_gc_end(sbi->sb, ret, total_freed, total_sec_freed,
1921                                 get_pages(sbi, F2FS_DIRTY_NODES),
1922                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1923                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1924                                 free_sections(sbi),
1925                                 free_segments(sbi),
1926                                 reserved_segments(sbi),
1927                                 prefree_segments(sbi));
1928
1929         f2fs_up_write(&sbi->gc_lock);
1930
1931         put_gc_inode(&gc_list);
1932
1933         if (gc_control->err_gc_skipped && !ret)
1934                 ret = total_sec_freed ? 0 : -EAGAIN;
1935         return ret;
1936 }
1937
1938 int __init f2fs_create_garbage_collection_cache(void)
1939 {
1940         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1941                                         sizeof(struct victim_entry));
1942         return victim_entry_slab ? 0 : -ENOMEM;
1943 }
1944
1945 void f2fs_destroy_garbage_collection_cache(void)
1946 {
1947         kmem_cache_destroy(victim_entry_slab);
1948 }
1949
1950 static void init_atgc_management(struct f2fs_sb_info *sbi)
1951 {
1952         struct atgc_management *am = &sbi->am;
1953
1954         if (test_opt(sbi, ATGC) &&
1955                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1956                 am->atgc_enabled = true;
1957
1958         am->root = RB_ROOT_CACHED;
1959         INIT_LIST_HEAD(&am->victim_list);
1960         am->victim_count = 0;
1961
1962         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1963         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1964         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1965         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1966 }
1967
1968 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1969 {
1970         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1971
1972         /* give warm/cold data area from slower device */
1973         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1974                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1975                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1976
1977         init_atgc_management(sbi);
1978 }
1979
1980 int f2fs_gc_range(struct f2fs_sb_info *sbi,
1981                 unsigned int start_seg, unsigned int end_seg,
1982                 bool dry_run, unsigned int dry_run_sections)
1983 {
1984         unsigned int segno;
1985         unsigned int gc_secs = dry_run_sections;
1986
1987         if (unlikely(f2fs_cp_error(sbi)))
1988                 return -EIO;
1989
1990         for (segno = start_seg; segno <= end_seg; segno += SEGS_PER_SEC(sbi)) {
1991                 struct gc_inode_list gc_list = {
1992                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1993                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1994                 };
1995
1996                 do_garbage_collect(sbi, segno, &gc_list, FG_GC,
1997                                                 dry_run_sections == 0);
1998                 put_gc_inode(&gc_list);
1999
2000                 if (!dry_run && get_valid_blocks(sbi, segno, true))
2001                         return -EAGAIN;
2002                 if (dry_run && dry_run_sections &&
2003                     !get_valid_blocks(sbi, segno, true) && --gc_secs == 0)
2004                         break;
2005
2006                 if (fatal_signal_pending(current))
2007                         return -ERESTARTSYS;
2008         }
2009
2010         return 0;
2011 }
2012
2013 static int free_segment_range(struct f2fs_sb_info *sbi,
2014                                 unsigned int secs, bool dry_run)
2015 {
2016         unsigned int next_inuse, start, end;
2017         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2018         int gc_mode, gc_type;
2019         int err = 0;
2020         int type;
2021
2022         /* Force block allocation for GC */
2023         MAIN_SECS(sbi) -= secs;
2024         start = MAIN_SECS(sbi) * SEGS_PER_SEC(sbi);
2025         end = MAIN_SEGS(sbi) - 1;
2026
2027         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2028         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
2029                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
2030                         SIT_I(sbi)->last_victim[gc_mode] = 0;
2031
2032         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
2033                 if (sbi->next_victim_seg[gc_type] >= start)
2034                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
2035         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
2036
2037         /* Move out cursegs from the target range */
2038         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++) {
2039                 err = f2fs_allocate_segment_for_resize(sbi, type, start, end);
2040                 if (err)
2041                         goto out;
2042         }
2043
2044         /* do GC to move out valid blocks in the range */
2045         err = f2fs_gc_range(sbi, start, end, dry_run, 0);
2046         if (err || dry_run)
2047                 goto out;
2048
2049         stat_inc_cp_call_count(sbi, TOTAL_CALL);
2050         err = f2fs_write_checkpoint(sbi, &cpc);
2051         if (err)
2052                 goto out;
2053
2054         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
2055         if (next_inuse <= end) {
2056                 f2fs_err(sbi, "segno %u should be free but still inuse!",
2057                          next_inuse);
2058                 f2fs_bug_on(sbi, 1);
2059         }
2060 out:
2061         MAIN_SECS(sbi) += secs;
2062         return err;
2063 }
2064
2065 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2066 {
2067         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2068         int section_count;
2069         int segment_count;
2070         int segment_count_main;
2071         long long block_count;
2072         int segs = secs * SEGS_PER_SEC(sbi);
2073
2074         f2fs_down_write(&sbi->sb_lock);
2075
2076         section_count = le32_to_cpu(raw_sb->section_count);
2077         segment_count = le32_to_cpu(raw_sb->segment_count);
2078         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2079         block_count = le64_to_cpu(raw_sb->block_count);
2080
2081         raw_sb->section_count = cpu_to_le32(section_count + secs);
2082         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2083         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2084         raw_sb->block_count = cpu_to_le64(block_count +
2085                         (long long)SEGS_TO_BLKS(sbi, segs));
2086         if (f2fs_is_multi_device(sbi)) {
2087                 int last_dev = sbi->s_ndevs - 1;
2088                 int dev_segs =
2089                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2090
2091                 raw_sb->devs[last_dev].total_segments =
2092                                                 cpu_to_le32(dev_segs + segs);
2093         }
2094
2095         f2fs_up_write(&sbi->sb_lock);
2096 }
2097
2098 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2099 {
2100         int segs = secs * SEGS_PER_SEC(sbi);
2101         long long blks = SEGS_TO_BLKS(sbi, segs);
2102         long long user_block_count =
2103                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2104
2105         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2106         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2107         MAIN_SECS(sbi) += secs;
2108         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2109         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2110         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2111
2112         if (f2fs_is_multi_device(sbi)) {
2113                 int last_dev = sbi->s_ndevs - 1;
2114
2115                 FDEV(last_dev).total_segments =
2116                                 (int)FDEV(last_dev).total_segments + segs;
2117                 FDEV(last_dev).end_blk =
2118                                 (long long)FDEV(last_dev).end_blk + blks;
2119 #ifdef CONFIG_BLK_DEV_ZONED
2120                 FDEV(last_dev).nr_blkz = FDEV(last_dev).nr_blkz +
2121                                         div_u64(blks, sbi->blocks_per_blkz);
2122 #endif
2123         }
2124 }
2125
2126 int f2fs_resize_fs(struct file *filp, __u64 block_count)
2127 {
2128         struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2129         __u64 old_block_count, shrunk_blocks;
2130         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2131         unsigned int secs;
2132         int err = 0;
2133         __u32 rem;
2134
2135         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2136         if (block_count > old_block_count)
2137                 return -EINVAL;
2138
2139         if (f2fs_is_multi_device(sbi)) {
2140                 int last_dev = sbi->s_ndevs - 1;
2141                 __u64 last_segs = FDEV(last_dev).total_segments;
2142
2143                 if (block_count + SEGS_TO_BLKS(sbi, last_segs) <=
2144                                                                 old_block_count)
2145                         return -EINVAL;
2146         }
2147
2148         /* new fs size should align to section size */
2149         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2150         if (rem)
2151                 return -EINVAL;
2152
2153         if (block_count == old_block_count)
2154                 return 0;
2155
2156         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2157                 f2fs_err(sbi, "Should run fsck to repair first.");
2158                 return -EFSCORRUPTED;
2159         }
2160
2161         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2162                 f2fs_err(sbi, "Checkpoint should be enabled.");
2163                 return -EINVAL;
2164         }
2165
2166         err = mnt_want_write_file(filp);
2167         if (err)
2168                 return err;
2169
2170         shrunk_blocks = old_block_count - block_count;
2171         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2172
2173         /* stop other GC */
2174         if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
2175                 err = -EAGAIN;
2176                 goto out_drop_write;
2177         }
2178
2179         /* stop CP to protect MAIN_SEC in free_segment_range */
2180         f2fs_lock_op(sbi);
2181
2182         spin_lock(&sbi->stat_lock);
2183         if (shrunk_blocks + valid_user_blocks(sbi) +
2184                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2185                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2186                 err = -ENOSPC;
2187         spin_unlock(&sbi->stat_lock);
2188
2189         if (err)
2190                 goto out_unlock;
2191
2192         err = free_segment_range(sbi, secs, true);
2193
2194 out_unlock:
2195         f2fs_unlock_op(sbi);
2196         f2fs_up_write(&sbi->gc_lock);
2197 out_drop_write:
2198         mnt_drop_write_file(filp);
2199         if (err)
2200                 return err;
2201
2202         err = freeze_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2203         if (err)
2204                 return err;
2205
2206         if (f2fs_readonly(sbi->sb)) {
2207                 err = thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2208                 if (err)
2209                         return err;
2210                 return -EROFS;
2211         }
2212
2213         f2fs_down_write(&sbi->gc_lock);
2214         f2fs_down_write(&sbi->cp_global_sem);
2215
2216         spin_lock(&sbi->stat_lock);
2217         if (shrunk_blocks + valid_user_blocks(sbi) +
2218                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2219                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2220                 err = -ENOSPC;
2221         else
2222                 sbi->user_block_count -= shrunk_blocks;
2223         spin_unlock(&sbi->stat_lock);
2224         if (err)
2225                 goto out_err;
2226
2227         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2228         err = free_segment_range(sbi, secs, false);
2229         if (err)
2230                 goto recover_out;
2231
2232         update_sb_metadata(sbi, -secs);
2233
2234         err = f2fs_commit_super(sbi, false);
2235         if (err) {
2236                 update_sb_metadata(sbi, secs);
2237                 goto recover_out;
2238         }
2239
2240         update_fs_metadata(sbi, -secs);
2241         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2242         set_sbi_flag(sbi, SBI_IS_DIRTY);
2243
2244         stat_inc_cp_call_count(sbi, TOTAL_CALL);
2245         err = f2fs_write_checkpoint(sbi, &cpc);
2246         if (err) {
2247                 update_fs_metadata(sbi, secs);
2248                 update_sb_metadata(sbi, secs);
2249                 f2fs_commit_super(sbi, false);
2250         }
2251 recover_out:
2252         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2253         if (err) {
2254                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2255                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2256
2257                 spin_lock(&sbi->stat_lock);
2258                 sbi->user_block_count += shrunk_blocks;
2259                 spin_unlock(&sbi->stat_lock);
2260         }
2261 out_err:
2262         f2fs_up_write(&sbi->cp_global_sem);
2263         f2fs_up_write(&sbi->gc_lock);
2264         thaw_super(sbi->sb, FREEZE_HOLDER_USERSPACE);
2265         return err;
2266 }