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_interruptible_timeout(*wq,
  50                                 kthread_should_stop() || freezing(current) ||
  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 = 0;
  61
  62                 if (try_to_freeze()) {
  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_show_injection_info(sbi, FAULT_CHECKPOINT);
  77                         f2fs_stop_checkpoint(sbi, false);
  78                 }
  79
  80                 if (!sb_start_write_trylock(sbi->sb)) {
  81                         stat_other_skip_bggc_count(sbi);
  82                         continue;
  83                 }
  84
  85                 /*
  86                  * [GC triggering condition]
  87                  * 0. GC is not conducted currently.
  88                  * 1. There are enough dirty segments.
  89                  * 2. IO subsystem is idle by checking the # of writeback pages.
  90                  * 3. IO subsystem is idle by checking the # of requests in
  91                  *    bdev's request list.
  92                  *
  93                  * Note) We have to avoid triggering GCs frequently.
  94                  * Because it is possible that some segments can be
  95                  * invalidated soon after by user update or deletion.
  96                  * So, I'd like to wait some time to collect dirty segments.
  97                  */
  98                 if (sbi->gc_mode == GC_URGENT_HIGH) {
  99                         spin_lock(&sbi->gc_urgent_high_lock);
 100                         if (sbi->gc_urgent_high_remaining) {
 101                                 sbi->gc_urgent_high_remaining--;
 102                                 if (!sbi->gc_urgent_high_remaining)
 103                                         sbi->gc_mode = GC_NORMAL;
 104                         }
 105                         spin_unlock(&sbi->gc_urgent_high_lock);
 106                 }
 107
 108                 if (sbi->gc_mode == GC_URGENT_HIGH ||
 109                                 sbi->gc_mode == GC_URGENT_MID) {
 110                         wait_ms = gc_th->urgent_sleep_time;
 111                         f2fs_down_write(&sbi->gc_lock);
 112                         goto do_gc;
 113                 }
 114
 115                 if (foreground) {
 116                         f2fs_down_write(&sbi->gc_lock);
 117                         goto do_gc;
 118                 } else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
 119                         stat_other_skip_bggc_count(sbi);
 120                         goto next;
 121                 }
 122
 123                 if (!is_idle(sbi, GC_TIME)) {
 124                         increase_sleep_time(gc_th, &wait_ms);
 125                         f2fs_up_write(&sbi->gc_lock);
 126                         stat_io_skip_bggc_count(sbi);
 127                         goto next;
 128                 }
 129
 130                 if (has_enough_invalid_blocks(sbi))
 131                         decrease_sleep_time(gc_th, &wait_ms);
 132                 else
 133                         increase_sleep_time(gc_th, &wait_ms);
 134 do_gc:
 135                 if (!foreground)
 136                         stat_inc_bggc_count(sbi->stat_info);
 137
 138                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 139
 140                 /* foreground GC was been triggered via f2fs_balance_fs() */
 141                 if (foreground)
 142                         sync_mode = false;
 143
 144                 gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
 145                 gc_control.no_bg_gc = foreground;
 146                 gc_control.nr_free_secs = foreground ? 1 : 0;
 147
 148                 /* if return value is not zero, no victim was selected */
 149                 if (f2fs_gc(sbi, &gc_control)) {
 150                         /* don't bother wait_ms by foreground gc */
 151                         if (!foreground)
 152                                 wait_ms = gc_th->no_gc_sleep_time;
 153                 }
 154
 155                 if (foreground)
 156                         wake_up_all(&gc_th->fggc_wq);
 157
 158                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 159                                 prefree_segments(sbi), free_segments(sbi));
 160
 161                 /* balancing f2fs's metadata periodically */
 162                 f2fs_balance_fs_bg(sbi, true);
 163 next:
 164                 sb_end_write(sbi->sb);
 165
 166         } while (!kthread_should_stop());
 167         return 0;
 168 }
 169
 170 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 171 {
 172         struct f2fs_gc_kthread *gc_th;
 173         dev_t dev = sbi->sb->s_bdev->bd_dev;
 174         int err = 0;
 175
 176         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 177         if (!gc_th) {
 178                 err = -ENOMEM;
 179                 goto out;
 180         }
 181
 182         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 183         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 184         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 185         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 186
 187         gc_th->gc_wake = 0;
 188
 189         sbi->gc_thread = gc_th;
 190         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 191         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 192         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 193                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 194         if (IS_ERR(gc_th->f2fs_gc_task)) {
 195                 err = PTR_ERR(gc_th->f2fs_gc_task);
 196                 kfree(gc_th);
 197                 sbi->gc_thread = NULL;
 198         }
 199 out:
 200         return err;
 201 }
 202
 203 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 204 {
 205         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 206
 207         if (!gc_th)
 208                 return;
 209         kthread_stop(gc_th->f2fs_gc_task);
 210         wake_up_all(&gc_th->fggc_wq);
 211         kfree(gc_th);
 212         sbi->gc_thread = NULL;
 213 }
 214
 215 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 216 {
 217         int gc_mode;
 218
 219         if (gc_type == BG_GC) {
 220                 if (sbi->am.atgc_enabled)
 221                         gc_mode = GC_AT;
 222                 else
 223                         gc_mode = GC_CB;
 224         } else {
 225                 gc_mode = GC_GREEDY;
 226         }
 227
 228         switch (sbi->gc_mode) {
 229         case GC_IDLE_CB:
 230                 gc_mode = GC_CB;
 231                 break;
 232         case GC_IDLE_GREEDY:
 233         case GC_URGENT_HIGH:
 234                 gc_mode = GC_GREEDY;
 235                 break;
 236         case GC_IDLE_AT:
 237                 gc_mode = GC_AT;
 238                 break;
 239         }
 240
 241         return gc_mode;
 242 }
 243
 244 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 245                         int type, struct victim_sel_policy *p)
 246 {
 247         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 248
 249         if (p->alloc_mode == SSR) {
 250                 p->gc_mode = GC_GREEDY;
 251                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 252                 p->max_search = dirty_i->nr_dirty[type];
 253                 p->ofs_unit = 1;
 254         } else if (p->alloc_mode == AT_SSR) {
 255                 p->gc_mode = GC_GREEDY;
 256                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 257                 p->max_search = dirty_i->nr_dirty[type];
 258                 p->ofs_unit = 1;
 259         } else {
 260                 p->gc_mode = select_gc_type(sbi, gc_type);
 261                 p->ofs_unit = sbi->segs_per_sec;
 262                 if (__is_large_section(sbi)) {
 263                         p->dirty_bitmap = dirty_i->dirty_secmap;
 264                         p->max_search = count_bits(p->dirty_bitmap,
 265                                                 0, MAIN_SECS(sbi));
 266                 } else {
 267                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 268                         p->max_search = dirty_i->nr_dirty[DIRTY];
 269                 }
 270         }
 271
 272         /*
 273          * adjust candidates range, should select all dirty segments for
 274          * foreground GC and urgent GC cases.
 275          */
 276         if (gc_type != FG_GC &&
 277                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 278                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 279                         p->max_search > sbi->max_victim_search)
 280                 p->max_search = sbi->max_victim_search;
 281
 282         /* let's select beginning hot/small space first in no_heap mode*/
 283         if (f2fs_need_rand_seg(sbi))
 284                 p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
 285         else if (test_opt(sbi, NOHEAP) &&
 286                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 287                 p->offset = 0;
 288         else
 289                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 290 }
 291
 292 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 293                                 struct victim_sel_policy *p)
 294 {
 295         /* SSR allocates in a segment unit */
 296         if (p->alloc_mode == SSR)
 297                 return sbi->blocks_per_seg;
 298         else if (p->alloc_mode == AT_SSR)
 299                 return UINT_MAX;
 300
 301         /* LFS */
 302         if (p->gc_mode == GC_GREEDY)
 303                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 304         else if (p->gc_mode == GC_CB)
 305                 return UINT_MAX;
 306         else if (p->gc_mode == GC_AT)
 307                 return UINT_MAX;
 308         else /* No other gc_mode */
 309                 return 0;
 310 }
 311
 312 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 313 {
 314         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 315         unsigned int secno;
 316
 317         /*
 318          * If the gc_type is FG_GC, we can select victim segments
 319          * selected by background GC before.
 320          * Those segments guarantee they have small valid blocks.
 321          */
 322         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 323                 if (sec_usage_check(sbi, secno))
 324                         continue;
 325                 clear_bit(secno, dirty_i->victim_secmap);
 326                 return GET_SEG_FROM_SEC(sbi, secno);
 327         }
 328         return NULL_SEGNO;
 329 }
 330
 331 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 332 {
 333         struct sit_info *sit_i = SIT_I(sbi);
 334         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 335         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 336         unsigned long long mtime = 0;
 337         unsigned int vblocks;
 338         unsigned char age = 0;
 339         unsigned char u;
 340         unsigned int i;
 341         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 342
 343         for (i = 0; i < usable_segs_per_sec; i++)
 344                 mtime += get_seg_entry(sbi, start + i)->mtime;
 345         vblocks = get_valid_blocks(sbi, segno, true);
 346
 347         mtime = div_u64(mtime, usable_segs_per_sec);
 348         vblocks = div_u64(vblocks, usable_segs_per_sec);
 349
 350         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 351
 352         /* Handle if the system time has changed by the user */
 353         if (mtime < sit_i->min_mtime)
 354                 sit_i->min_mtime = mtime;
 355         if (mtime > sit_i->max_mtime)
 356                 sit_i->max_mtime = mtime;
 357         if (sit_i->max_mtime != sit_i->min_mtime)
 358                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 359                                 sit_i->max_mtime - sit_i->min_mtime);
 360
 361         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 362 }
 363
 364 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 365                         unsigned int segno, struct victim_sel_policy *p)
 366 {
 367         if (p->alloc_mode == SSR)
 368                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 369
 370         /* alloc_mode == LFS */
 371         if (p->gc_mode == GC_GREEDY)
 372                 return get_valid_blocks(sbi, segno, true);
 373         else if (p->gc_mode == GC_CB)
 374                 return get_cb_cost(sbi, segno);
 375
 376         f2fs_bug_on(sbi, 1);
 377         return 0;
 378 }
 379
 380 static unsigned int count_bits(const unsigned long *addr,
 381                                 unsigned int offset, unsigned int len)
 382 {
 383         unsigned int end = offset + len, sum = 0;
 384
 385         while (offset < end) {
 386                 if (test_bit(offset++, addr))
 387                         ++sum;
 388         }
 389         return sum;
 390 }
 391
 392 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 393                                 unsigned long long mtime, unsigned int segno,
 394                                 struct rb_node *parent, struct rb_node **p,
 395                                 bool left_most)
 396 {
 397         struct atgc_management *am = &sbi->am;
 398         struct victim_entry *ve;
 399
 400         ve =  f2fs_kmem_cache_alloc(victim_entry_slab,
 401                                 GFP_NOFS, true, NULL);
 402
 403         ve->mtime = mtime;
 404         ve->segno = segno;
 405
 406         rb_link_node(&ve->rb_node, parent, p);
 407         rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 408
 409         list_add_tail(&ve->list, &am->victim_list);
 410
 411         am->victim_count++;
 412
 413         return ve;
 414 }
 415
 416 static void insert_victim_entry(struct f2fs_sb_info *sbi,
 417                                 unsigned long long mtime, unsigned int segno)
 418 {
 419         struct atgc_management *am = &sbi->am;
 420         struct rb_node **p;
 421         struct rb_node *parent = NULL;
 422         bool left_most = true;
 423
 424         p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 425         attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 426 }
 427
 428 static void add_victim_entry(struct f2fs_sb_info *sbi,
 429                                 struct victim_sel_policy *p, unsigned int segno)
 430 {
 431         struct sit_info *sit_i = SIT_I(sbi);
 432         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 433         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 434         unsigned long long mtime = 0;
 435         unsigned int i;
 436
 437         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 438                 if (p->gc_mode == GC_AT &&
 439                         get_valid_blocks(sbi, segno, true) == 0)
 440                         return;
 441         }
 442
 443         for (i = 0; i < sbi->segs_per_sec; i++)
 444                 mtime += get_seg_entry(sbi, start + i)->mtime;
 445         mtime = div_u64(mtime, sbi->segs_per_sec);
 446
 447         /* Handle if the system time has changed by the user */
 448         if (mtime < sit_i->min_mtime)
 449                 sit_i->min_mtime = mtime;
 450         if (mtime > sit_i->max_mtime)
 451                 sit_i->max_mtime = mtime;
 452         if (mtime < sit_i->dirty_min_mtime)
 453                 sit_i->dirty_min_mtime = mtime;
 454         if (mtime > sit_i->dirty_max_mtime)
 455                 sit_i->dirty_max_mtime = mtime;
 456
 457         /* don't choose young section as candidate */
 458         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 459                 return;
 460
 461         insert_victim_entry(sbi, mtime, segno);
 462 }
 463
 464 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 465                                                 struct victim_sel_policy *p)
 466 {
 467         struct atgc_management *am = &sbi->am;
 468         struct rb_node *parent = NULL;
 469         bool left_most;
 470
 471         f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 472
 473         return parent;
 474 }
 475
 476 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 477                                                 struct victim_sel_policy *p)
 478 {
 479         struct sit_info *sit_i = SIT_I(sbi);
 480         struct atgc_management *am = &sbi->am;
 481         struct rb_root_cached *root = &am->root;
 482         struct rb_node *node;
 483         struct rb_entry *re;
 484         struct victim_entry *ve;
 485         unsigned long long total_time;
 486         unsigned long long age, u, accu;
 487         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 488         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 489         unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
 490         unsigned int vblocks;
 491         unsigned int dirty_threshold = max(am->max_candidate_count,
 492                                         am->candidate_ratio *
 493                                         am->victim_count / 100);
 494         unsigned int age_weight = am->age_weight;
 495         unsigned int cost;
 496         unsigned int iter = 0;
 497
 498         if (max_mtime < min_mtime)
 499                 return;
 500
 501         max_mtime += 1;
 502         total_time = max_mtime - min_mtime;
 503
 504         accu = div64_u64(ULLONG_MAX, total_time);
 505         accu = min_t(unsigned long long, div_u64(accu, 100),
 506                                         DEFAULT_ACCURACY_CLASS);
 507
 508         node = rb_first_cached(root);
 509 next:
 510         re = rb_entry_safe(node, struct rb_entry, rb_node);
 511         if (!re)
 512                 return;
 513
 514         ve = (struct victim_entry *)re;
 515
 516         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 517                 goto skip;
 518
 519         /* age = 10000 * x% * 60 */
 520         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 521                                                                 age_weight;
 522
 523         vblocks = get_valid_blocks(sbi, ve->segno, true);
 524         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 525
 526         /* u = 10000 * x% * 40 */
 527         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 528                                                         (100 - age_weight);
 529
 530         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 531
 532         cost = UINT_MAX - (age + u);
 533         iter++;
 534
 535         if (cost < p->min_cost ||
 536                         (cost == p->min_cost && age > p->oldest_age)) {
 537                 p->min_cost = cost;
 538                 p->oldest_age = age;
 539                 p->min_segno = ve->segno;
 540         }
 541 skip:
 542         if (iter < dirty_threshold) {
 543                 node = rb_next(node);
 544                 goto next;
 545         }
 546 }
 547
 548 /*
 549  * select candidates around source section in range of
 550  * [target - dirty_threshold, target + dirty_threshold]
 551  */
 552 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 553                                                 struct victim_sel_policy *p)
 554 {
 555         struct sit_info *sit_i = SIT_I(sbi);
 556         struct atgc_management *am = &sbi->am;
 557         struct rb_node *node;
 558         struct rb_entry *re;
 559         struct victim_entry *ve;
 560         unsigned long long age;
 561         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 562         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 563         unsigned int seg_blocks = sbi->blocks_per_seg;
 564         unsigned int vblocks;
 565         unsigned int dirty_threshold = max(am->max_candidate_count,
 566                                         am->candidate_ratio *
 567                                         am->victim_count / 100);
 568         unsigned int cost;
 569         unsigned int iter = 0;
 570         int stage = 0;
 571
 572         if (max_mtime < min_mtime)
 573                 return;
 574         max_mtime += 1;
 575 next_stage:
 576         node = lookup_central_victim(sbi, p);
 577 next_node:
 578         re = rb_entry_safe(node, struct rb_entry, rb_node);
 579         if (!re) {
 580                 if (stage == 0)
 581                         goto skip_stage;
 582                 return;
 583         }
 584
 585         ve = (struct victim_entry *)re;
 586
 587         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 588                 goto skip_node;
 589
 590         age = max_mtime - ve->mtime;
 591
 592         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 593         f2fs_bug_on(sbi, !vblocks);
 594
 595         /* rare case */
 596         if (vblocks == seg_blocks)
 597                 goto skip_node;
 598
 599         iter++;
 600
 601         age = max_mtime - abs(p->age - age);
 602         cost = UINT_MAX - vblocks;
 603
 604         if (cost < p->min_cost ||
 605                         (cost == p->min_cost && age > p->oldest_age)) {
 606                 p->min_cost = cost;
 607                 p->oldest_age = age;
 608                 p->min_segno = ve->segno;
 609         }
 610 skip_node:
 611         if (iter < dirty_threshold) {
 612                 if (stage == 0)
 613                         node = rb_prev(node);
 614                 else if (stage == 1)
 615                         node = rb_next(node);
 616                 goto next_node;
 617         }
 618 skip_stage:
 619         if (stage < 1) {
 620                 stage++;
 621                 iter = 0;
 622                 goto next_stage;
 623         }
 624 }
 625 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 626                                                 struct victim_sel_policy *p)
 627 {
 628         f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 629                                                 &sbi->am.root, true));
 630
 631         if (p->gc_mode == GC_AT)
 632                 atgc_lookup_victim(sbi, p);
 633         else if (p->alloc_mode == AT_SSR)
 634                 atssr_lookup_victim(sbi, p);
 635         else
 636                 f2fs_bug_on(sbi, 1);
 637 }
 638
 639 static void release_victim_entry(struct f2fs_sb_info *sbi)
 640 {
 641         struct atgc_management *am = &sbi->am;
 642         struct victim_entry *ve, *tmp;
 643
 644         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 645                 list_del(&ve->list);
 646                 kmem_cache_free(victim_entry_slab, ve);
 647                 am->victim_count--;
 648         }
 649
 650         am->root = RB_ROOT_CACHED;
 651
 652         f2fs_bug_on(sbi, am->victim_count);
 653         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 654 }
 655
 656 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
 657 {
 658         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 659         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 660
 661         if (!dirty_i->enable_pin_section)
 662                 return false;
 663         if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
 664                 dirty_i->pinned_secmap_cnt++;
 665         return true;
 666 }
 667
 668 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
 669 {
 670         return dirty_i->pinned_secmap_cnt;
 671 }
 672
 673 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
 674                                                 unsigned int secno)
 675 {
 676         return dirty_i->enable_pin_section &&
 677                 f2fs_pinned_section_exists(dirty_i) &&
 678                 test_bit(secno, dirty_i->pinned_secmap);
 679 }
 680
 681 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
 682 {
 683         unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 684
 685         if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
 686                 memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
 687                 DIRTY_I(sbi)->pinned_secmap_cnt = 0;
 688         }
 689         DIRTY_I(sbi)->enable_pin_section = enable;
 690 }
 691
 692 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
 693                                                         unsigned int segno)
 694 {
 695         if (!f2fs_is_pinned_file(inode))
 696                 return 0;
 697         if (gc_type != FG_GC)
 698                 return -EBUSY;
 699         if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
 700                 f2fs_pin_file_control(inode, true);
 701         return -EAGAIN;
 702 }
 703
 704 /*
 705  * This function is called from two paths.
 706  * One is garbage collection and the other is SSR segment selection.
 707  * When it is called during GC, it just gets a victim segment
 708  * and it does not remove it from dirty seglist.
 709  * When it is called from SSR segment selection, it finds a segment
 710  * which has minimum valid blocks and removes it from dirty seglist.
 711  */
 712 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 713                         unsigned int *result, int gc_type, int type,
 714                         char alloc_mode, unsigned long long age)
 715 {
 716         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 717         struct sit_info *sm = SIT_I(sbi);
 718         struct victim_sel_policy p;
 719         unsigned int secno, last_victim;
 720         unsigned int last_segment;
 721         unsigned int nsearched;
 722         bool is_atgc;
 723         int ret = 0;
 724
 725         mutex_lock(&dirty_i->seglist_lock);
 726         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 727
 728         p.alloc_mode = alloc_mode;
 729         p.age = age;
 730         p.age_threshold = sbi->am.age_threshold;
 731
 732 retry:
 733         select_policy(sbi, gc_type, type, &p);
 734         p.min_segno = NULL_SEGNO;
 735         p.oldest_age = 0;
 736         p.min_cost = get_max_cost(sbi, &p);
 737
 738         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 739         nsearched = 0;
 740
 741         if (is_atgc)
 742                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 743
 744         if (*result != NULL_SEGNO) {
 745                 if (!get_valid_blocks(sbi, *result, false)) {
 746                         ret = -ENODATA;
 747                         goto out;
 748                 }
 749
 750                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 751                         ret = -EBUSY;
 752                 else
 753                         p.min_segno = *result;
 754                 goto out;
 755         }
 756
 757         ret = -ENODATA;
 758         if (p.max_search == 0)
 759                 goto out;
 760
 761         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 762                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 763                         p.min_segno = sbi->next_victim_seg[BG_GC];
 764                         *result = p.min_segno;
 765                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 766                         goto got_result;
 767                 }
 768                 if (gc_type == FG_GC &&
 769                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 770                         p.min_segno = sbi->next_victim_seg[FG_GC];
 771                         *result = p.min_segno;
 772                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 773                         goto got_result;
 774                 }
 775         }
 776
 777         last_victim = sm->last_victim[p.gc_mode];
 778         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 779                 p.min_segno = check_bg_victims(sbi);
 780                 if (p.min_segno != NULL_SEGNO)
 781                         goto got_it;
 782         }
 783
 784         while (1) {
 785                 unsigned long cost, *dirty_bitmap;
 786                 unsigned int unit_no, segno;
 787
 788                 dirty_bitmap = p.dirty_bitmap;
 789                 unit_no = find_next_bit(dirty_bitmap,
 790                                 last_segment / p.ofs_unit,
 791                                 p.offset / p.ofs_unit);
 792                 segno = unit_no * p.ofs_unit;
 793                 if (segno >= last_segment) {
 794                         if (sm->last_victim[p.gc_mode]) {
 795                                 last_segment =
 796                                         sm->last_victim[p.gc_mode];
 797                                 sm->last_victim[p.gc_mode] = 0;
 798                                 p.offset = 0;
 799                                 continue;
 800                         }
 801                         break;
 802                 }
 803
 804                 p.offset = segno + p.ofs_unit;
 805                 nsearched++;
 806
 807 #ifdef CONFIG_F2FS_CHECK_FS
 808                 /*
 809                  * skip selecting the invalid segno (that is failed due to block
 810                  * validity check failure during GC) to avoid endless GC loop in
 811                  * such cases.
 812                  */
 813                 if (test_bit(segno, sm->invalid_segmap))
 814                         goto next;
 815 #endif
 816
 817                 secno = GET_SEC_FROM_SEG(sbi, segno);
 818
 819                 if (sec_usage_check(sbi, secno))
 820                         goto next;
 821
 822                 /* Don't touch checkpointed data */
 823                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 824                         if (p.alloc_mode == LFS) {
 825                                 /*
 826                                  * LFS is set to find source section during GC.
 827                                  * The victim should have no checkpointed data.
 828                                  */
 829                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 830                                         goto next;
 831                         } else {
 832                                 /*
 833                                  * SSR | AT_SSR are set to find target segment
 834                                  * for writes which can be full by checkpointed
 835                                  * and newly written blocks.
 836                                  */
 837                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 838                                         goto next;
 839                         }
 840                 }
 841
 842                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 843                         goto next;
 844
 845                 if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
 846                         goto next;
 847
 848                 if (is_atgc) {
 849                         add_victim_entry(sbi, &p, segno);
 850                         goto next;
 851                 }
 852
 853                 cost = get_gc_cost(sbi, segno, &p);
 854
 855                 if (p.min_cost > cost) {
 856                         p.min_segno = segno;
 857                         p.min_cost = cost;
 858                 }
 859 next:
 860                 if (nsearched >= p.max_search) {
 861                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 862                                 sm->last_victim[p.gc_mode] =
 863                                         last_victim + p.ofs_unit;
 864                         else
 865                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 866                         sm->last_victim[p.gc_mode] %=
 867                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 868                         break;
 869                 }
 870         }
 871
 872         /* get victim for GC_AT/AT_SSR */
 873         if (is_atgc) {
 874                 lookup_victim_by_age(sbi, &p);
 875                 release_victim_entry(sbi);
 876         }
 877
 878         if (is_atgc && p.min_segno == NULL_SEGNO &&
 879                         sm->elapsed_time < p.age_threshold) {
 880                 p.age_threshold = 0;
 881                 goto retry;
 882         }
 883
 884         if (p.min_segno != NULL_SEGNO) {
 885 got_it:
 886                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 887 got_result:
 888                 if (p.alloc_mode == LFS) {
 889                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 890                         if (gc_type == FG_GC)
 891                                 sbi->cur_victim_sec = secno;
 892                         else
 893                                 set_bit(secno, dirty_i->victim_secmap);
 894                 }
 895                 ret = 0;
 896
 897         }
 898 out:
 899         if (p.min_segno != NULL_SEGNO)
 900                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 901                                 sbi->cur_victim_sec,
 902                                 prefree_segments(sbi), free_segments(sbi));
 903         mutex_unlock(&dirty_i->seglist_lock);
 904
 905         return ret;
 906 }
 907
 908 static const struct victim_selection default_v_ops = {
 909         .get_victim = get_victim_by_default,
 910 };
 911
 912 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 913 {
 914         struct inode_entry *ie;
 915
 916         ie = radix_tree_lookup(&gc_list->iroot, ino);
 917         if (ie)
 918                 return ie->inode;
 919         return NULL;
 920 }
 921
 922 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 923 {
 924         struct inode_entry *new_ie;
 925
 926         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 927                 iput(inode);
 928                 return;
 929         }
 930         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 931                                         GFP_NOFS, true, NULL);
 932         new_ie->inode = inode;
 933
 934         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 935         list_add_tail(&new_ie->list, &gc_list->ilist);
 936 }
 937
 938 static void put_gc_inode(struct gc_inode_list *gc_list)
 939 {
 940         struct inode_entry *ie, *next_ie;
 941
 942         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 943                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 944                 iput(ie->inode);
 945                 list_del(&ie->list);
 946                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 947         }
 948 }
 949
 950 static int check_valid_map(struct f2fs_sb_info *sbi,
 951                                 unsigned int segno, int offset)
 952 {
 953         struct sit_info *sit_i = SIT_I(sbi);
 954         struct seg_entry *sentry;
 955         int ret;
 956
 957         down_read(&sit_i->sentry_lock);
 958         sentry = get_seg_entry(sbi, segno);
 959         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 960         up_read(&sit_i->sentry_lock);
 961         return ret;
 962 }
 963
 964 /*
 965  * This function compares node address got in summary with that in NAT.
 966  * On validity, copy that node with cold status, otherwise (invalid node)
 967  * ignore that.
 968  */
 969 static int gc_node_segment(struct f2fs_sb_info *sbi,
 970                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 971 {
 972         struct f2fs_summary *entry;
 973         block_t start_addr;
 974         int off;
 975         int phase = 0;
 976         bool fggc = (gc_type == FG_GC);
 977         int submitted = 0;
 978         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 979
 980         start_addr = START_BLOCK(sbi, segno);
 981
 982 next_step:
 983         entry = sum;
 984
 985         if (fggc && phase == 2)
 986                 atomic_inc(&sbi->wb_sync_req[NODE]);
 987
 988         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 989                 nid_t nid = le32_to_cpu(entry->nid);
 990                 struct page *node_page;
 991                 struct node_info ni;
 992                 int err;
 993
 994                 /* stop BG_GC if there is not enough free sections. */
 995                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 996                         return submitted;
 997
 998                 if (check_valid_map(sbi, segno, off) == 0)
 999                         continue;
1000
1001                 if (phase == 0) {
1002                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1003                                                         META_NAT, true);
1004                         continue;
1005                 }
1006
1007                 if (phase == 1) {
1008                         f2fs_ra_node_page(sbi, nid);
1009                         continue;
1010                 }
1011
1012                 /* phase == 2 */
1013                 node_page = f2fs_get_node_page(sbi, nid);
1014                 if (IS_ERR(node_page))
1015                         continue;
1016
1017                 /* block may become invalid during f2fs_get_node_page */
1018                 if (check_valid_map(sbi, segno, off) == 0) {
1019                         f2fs_put_page(node_page, 1);
1020                         continue;
1021                 }
1022
1023                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1024                         f2fs_put_page(node_page, 1);
1025                         continue;
1026                 }
1027
1028                 if (ni.blk_addr != start_addr + off) {
1029                         f2fs_put_page(node_page, 1);
1030                         continue;
1031                 }
1032
1033                 err = f2fs_move_node_page(node_page, gc_type);
1034                 if (!err && gc_type == FG_GC)
1035                         submitted++;
1036                 stat_inc_node_blk_count(sbi, 1, gc_type);
1037         }
1038
1039         if (++phase < 3)
1040                 goto next_step;
1041
1042         if (fggc)
1043                 atomic_dec(&sbi->wb_sync_req[NODE]);
1044         return submitted;
1045 }
1046
1047 /*
1048  * Calculate start block index indicating the given node offset.
1049  * Be careful, caller should give this node offset only indicating direct node
1050  * blocks. If any node offsets, which point the other types of node blocks such
1051  * as indirect or double indirect node blocks, are given, it must be a caller's
1052  * bug.
1053  */
1054 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1055 {
1056         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1057         unsigned int bidx;
1058
1059         if (node_ofs == 0)
1060                 return 0;
1061
1062         if (node_ofs <= 2) {
1063                 bidx = node_ofs - 1;
1064         } else if (node_ofs <= indirect_blks) {
1065                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1066
1067                 bidx = node_ofs - 2 - dec;
1068         } else {
1069                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1070
1071                 bidx = node_ofs - 5 - dec;
1072         }
1073         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1074 }
1075
1076 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1077                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1078 {
1079         struct page *node_page;
1080         nid_t nid;
1081         unsigned int ofs_in_node, max_addrs;
1082         block_t source_blkaddr;
1083
1084         nid = le32_to_cpu(sum->nid);
1085         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1086
1087         node_page = f2fs_get_node_page(sbi, nid);
1088         if (IS_ERR(node_page))
1089                 return false;
1090
1091         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1092                 f2fs_put_page(node_page, 1);
1093                 return false;
1094         }
1095
1096         if (sum->version != dni->version) {
1097                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1098                           __func__);
1099                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1100         }
1101
1102         if (f2fs_check_nid_range(sbi, dni->ino)) {
1103                 f2fs_put_page(node_page, 1);
1104                 return false;
1105         }
1106
1107         max_addrs = IS_INODE(node_page) ? DEF_ADDRS_PER_INODE :
1108                                                 DEF_ADDRS_PER_BLOCK;
1109         if (ofs_in_node >= max_addrs) {
1110                 f2fs_err(sbi, "Inconsistent ofs_in_node:%u in summary, ino:%u, nid:%u, max:%u",
1111                         ofs_in_node, dni->ino, dni->nid, max_addrs);
1112                 return false;
1113         }
1114
1115         *nofs = ofs_of_node(node_page);
1116         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1117         f2fs_put_page(node_page, 1);
1118
1119         if (source_blkaddr != blkaddr) {
1120 #ifdef CONFIG_F2FS_CHECK_FS
1121                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1122                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1123
1124                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1125                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1126                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1127                                          blkaddr, source_blkaddr, segno);
1128                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1129                         }
1130                 }
1131 #endif
1132                 return false;
1133         }
1134         return true;
1135 }
1136
1137 static int ra_data_block(struct inode *inode, pgoff_t index)
1138 {
1139         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1140         struct address_space *mapping = inode->i_mapping;
1141         struct dnode_of_data dn;
1142         struct page *page;
1143         struct extent_info ei = {0, 0, 0};
1144         struct f2fs_io_info fio = {
1145                 .sbi = sbi,
1146                 .ino = inode->i_ino,
1147                 .type = DATA,
1148                 .temp = COLD,
1149                 .op = REQ_OP_READ,
1150                 .op_flags = 0,
1151                 .encrypted_page = NULL,
1152                 .in_list = false,
1153                 .retry = false,
1154         };
1155         int err;
1156
1157         page = f2fs_grab_cache_page(mapping, index, true);
1158         if (!page)
1159                 return -ENOMEM;
1160
1161         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1162                 dn.data_blkaddr = ei.blk + index - ei.fofs;
1163                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1164                                                 DATA_GENERIC_ENHANCE_READ))) {
1165                         err = -EFSCORRUPTED;
1166                         goto put_page;
1167                 }
1168                 goto got_it;
1169         }
1170
1171         set_new_dnode(&dn, inode, NULL, NULL, 0);
1172         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1173         if (err)
1174                 goto put_page;
1175         f2fs_put_dnode(&dn);
1176
1177         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1178                 err = -ENOENT;
1179                 goto put_page;
1180         }
1181         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1182                                                 DATA_GENERIC_ENHANCE))) {
1183                 err = -EFSCORRUPTED;
1184                 goto put_page;
1185         }
1186 got_it:
1187         /* read page */
1188         fio.page = page;
1189         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1190
1191         /*
1192          * don't cache encrypted data into meta inode until previous dirty
1193          * data were writebacked to avoid racing between GC and flush.
1194          */
1195         f2fs_wait_on_page_writeback(page, DATA, true, true);
1196
1197         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1198
1199         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1200                                         dn.data_blkaddr,
1201                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1202         if (!fio.encrypted_page) {
1203                 err = -ENOMEM;
1204                 goto put_page;
1205         }
1206
1207         err = f2fs_submit_page_bio(&fio);
1208         if (err)
1209                 goto put_encrypted_page;
1210         f2fs_put_page(fio.encrypted_page, 0);
1211         f2fs_put_page(page, 1);
1212
1213         f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1214         f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1215
1216         return 0;
1217 put_encrypted_page:
1218         f2fs_put_page(fio.encrypted_page, 1);
1219 put_page:
1220         f2fs_put_page(page, 1);
1221         return err;
1222 }
1223
1224 /*
1225  * Move data block via META_MAPPING while keeping locked data page.
1226  * This can be used to move blocks, aka LBAs, directly on disk.
1227  */
1228 static int move_data_block(struct inode *inode, block_t bidx,
1229                                 int gc_type, unsigned int segno, int off)
1230 {
1231         struct f2fs_io_info fio = {
1232                 .sbi = F2FS_I_SB(inode),
1233                 .ino = inode->i_ino,
1234                 .type = DATA,
1235                 .temp = COLD,
1236                 .op = REQ_OP_READ,
1237                 .op_flags = 0,
1238                 .encrypted_page = NULL,
1239                 .in_list = false,
1240                 .retry = false,
1241         };
1242         struct dnode_of_data dn;
1243         struct f2fs_summary sum;
1244         struct node_info ni;
1245         struct page *page, *mpage;
1246         block_t newaddr;
1247         int err = 0;
1248         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1249         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1250                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1251                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1252
1253         /* do not read out */
1254         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1255         if (!page)
1256                 return -ENOMEM;
1257
1258         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1259                 err = -ENOENT;
1260                 goto out;
1261         }
1262
1263         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1264         if (err)
1265                 goto out;
1266
1267         set_new_dnode(&dn, inode, NULL, NULL, 0);
1268         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1269         if (err)
1270                 goto out;
1271
1272         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1273                 ClearPageUptodate(page);
1274                 err = -ENOENT;
1275                 goto put_out;
1276         }
1277
1278         /*
1279          * don't cache encrypted data into meta inode until previous dirty
1280          * data were writebacked to avoid racing between GC and flush.
1281          */
1282         f2fs_wait_on_page_writeback(page, DATA, true, true);
1283
1284         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1285
1286         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1287         if (err)
1288                 goto put_out;
1289
1290         /* read page */
1291         fio.page = page;
1292         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1293
1294         if (lfs_mode)
1295                 f2fs_down_write(&fio.sbi->io_order_lock);
1296
1297         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1298                                         fio.old_blkaddr, false);
1299         if (!mpage) {
1300                 err = -ENOMEM;
1301                 goto up_out;
1302         }
1303
1304         fio.encrypted_page = mpage;
1305
1306         /* read source block in mpage */
1307         if (!PageUptodate(mpage)) {
1308                 err = f2fs_submit_page_bio(&fio);
1309                 if (err) {
1310                         f2fs_put_page(mpage, 1);
1311                         goto up_out;
1312                 }
1313
1314                 f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1315                                                         F2FS_BLKSIZE);
1316                 f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1317                                                         F2FS_BLKSIZE);
1318
1319                 lock_page(mpage);
1320                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1321                                                 !PageUptodate(mpage))) {
1322                         err = -EIO;
1323                         f2fs_put_page(mpage, 1);
1324                         goto up_out;
1325                 }
1326         }
1327
1328         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1329
1330         /* allocate block address */
1331         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1332                                 &sum, type, NULL);
1333
1334         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1335                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1336         if (!fio.encrypted_page) {
1337                 err = -ENOMEM;
1338                 f2fs_put_page(mpage, 1);
1339                 goto recover_block;
1340         }
1341
1342         /* write target block */
1343         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1344         memcpy(page_address(fio.encrypted_page),
1345                                 page_address(mpage), PAGE_SIZE);
1346         f2fs_put_page(mpage, 1);
1347         invalidate_mapping_pages(META_MAPPING(fio.sbi),
1348                                 fio.old_blkaddr, fio.old_blkaddr);
1349         f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1350
1351         set_page_dirty(fio.encrypted_page);
1352         if (clear_page_dirty_for_io(fio.encrypted_page))
1353                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1354
1355         set_page_writeback(fio.encrypted_page);
1356         ClearPageError(page);
1357
1358         fio.op = REQ_OP_WRITE;
1359         fio.op_flags = REQ_SYNC;
1360         fio.new_blkaddr = newaddr;
1361         f2fs_submit_page_write(&fio);
1362         if (fio.retry) {
1363                 err = -EAGAIN;
1364                 if (PageWriteback(fio.encrypted_page))
1365                         end_page_writeback(fio.encrypted_page);
1366                 goto put_page_out;
1367         }
1368
1369         f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1370
1371         f2fs_update_data_blkaddr(&dn, newaddr);
1372         set_inode_flag(inode, FI_APPEND_WRITE);
1373         if (page->index == 0)
1374                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1375 put_page_out:
1376         f2fs_put_page(fio.encrypted_page, 1);
1377 recover_block:
1378         if (err)
1379                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1380                                                         true, true, true);
1381 up_out:
1382         if (lfs_mode)
1383                 f2fs_up_write(&fio.sbi->io_order_lock);
1384 put_out:
1385         f2fs_put_dnode(&dn);
1386 out:
1387         f2fs_put_page(page, 1);
1388         return err;
1389 }
1390
1391 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1392                                                         unsigned int segno, int off)
1393 {
1394         struct page *page;
1395         int err = 0;
1396
1397         page = f2fs_get_lock_data_page(inode, bidx, true);
1398         if (IS_ERR(page))
1399                 return PTR_ERR(page);
1400
1401         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1402                 err = -ENOENT;
1403                 goto out;
1404         }
1405
1406         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1407         if (err)
1408                 goto out;
1409
1410         if (gc_type == BG_GC) {
1411                 if (PageWriteback(page)) {
1412                         err = -EAGAIN;
1413                         goto out;
1414                 }
1415                 set_page_dirty(page);
1416                 set_page_private_gcing(page);
1417         } else {
1418                 struct f2fs_io_info fio = {
1419                         .sbi = F2FS_I_SB(inode),
1420                         .ino = inode->i_ino,
1421                         .type = DATA,
1422                         .temp = COLD,
1423                         .op = REQ_OP_WRITE,
1424                         .op_flags = REQ_SYNC,
1425                         .old_blkaddr = NULL_ADDR,
1426                         .page = page,
1427                         .encrypted_page = NULL,
1428                         .need_lock = LOCK_REQ,
1429                         .io_type = FS_GC_DATA_IO,
1430                 };
1431                 bool is_dirty = PageDirty(page);
1432
1433 retry:
1434                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1435
1436                 set_page_dirty(page);
1437                 if (clear_page_dirty_for_io(page)) {
1438                         inode_dec_dirty_pages(inode);
1439                         f2fs_remove_dirty_inode(inode);
1440                 }
1441
1442                 set_page_private_gcing(page);
1443
1444                 err = f2fs_do_write_data_page(&fio);
1445                 if (err) {
1446                         clear_page_private_gcing(page);
1447                         if (err == -ENOMEM) {
1448                                 memalloc_retry_wait(GFP_NOFS);
1449                                 goto retry;
1450                         }
1451                         if (is_dirty)
1452                                 set_page_dirty(page);
1453                 }
1454         }
1455 out:
1456         f2fs_put_page(page, 1);
1457         return err;
1458 }
1459
1460 /*
1461  * This function tries to get parent node of victim data block, and identifies
1462  * data block validity. If the block is valid, copy that with cold status and
1463  * modify parent node.
1464  * If the parent node is not valid or the data block address is different,
1465  * the victim data block is ignored.
1466  */
1467 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1468                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1469                 bool force_migrate)
1470 {
1471         struct super_block *sb = sbi->sb;
1472         struct f2fs_summary *entry;
1473         block_t start_addr;
1474         int off;
1475         int phase = 0;
1476         int submitted = 0;
1477         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1478
1479         start_addr = START_BLOCK(sbi, segno);
1480
1481 next_step:
1482         entry = sum;
1483
1484         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1485                 struct page *data_page;
1486                 struct inode *inode;
1487                 struct node_info dni; /* dnode info for the data */
1488                 unsigned int ofs_in_node, nofs;
1489                 block_t start_bidx;
1490                 nid_t nid = le32_to_cpu(entry->nid);
1491
1492                 /*
1493                  * stop BG_GC if there is not enough free sections.
1494                  * Or, stop GC if the segment becomes fully valid caused by
1495                  * race condition along with SSR block allocation.
1496                  */
1497                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1498                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1499                                                         CAP_BLKS_PER_SEC(sbi)))
1500                         return submitted;
1501
1502                 if (check_valid_map(sbi, segno, off) == 0)
1503                         continue;
1504
1505                 if (phase == 0) {
1506                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1507                                                         META_NAT, true);
1508                         continue;
1509                 }
1510
1511                 if (phase == 1) {
1512                         f2fs_ra_node_page(sbi, nid);
1513                         continue;
1514                 }
1515
1516                 /* Get an inode by ino with checking validity */
1517                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1518                         continue;
1519
1520                 if (phase == 2) {
1521                         f2fs_ra_node_page(sbi, dni.ino);
1522                         continue;
1523                 }
1524
1525                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1526
1527                 if (phase == 3) {
1528                         int err;
1529
1530                         inode = f2fs_iget(sb, dni.ino);
1531                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1532                                         special_file(inode->i_mode))
1533                                 continue;
1534
1535                         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1536                         if (err == -EAGAIN) {
1537                                 iput(inode);
1538                                 return submitted;
1539                         }
1540
1541                         if (!f2fs_down_write_trylock(
1542                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1543                                 iput(inode);
1544                                 sbi->skipped_gc_rwsem++;
1545                                 continue;
1546                         }
1547
1548                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1549                                                                 ofs_in_node;
1550
1551                         if (f2fs_post_read_required(inode)) {
1552                                 int err = ra_data_block(inode, start_bidx);
1553
1554                                 f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1555                                 if (err) {
1556                                         iput(inode);
1557                                         continue;
1558                                 }
1559                                 add_gc_inode(gc_list, inode);
1560                                 continue;
1561                         }
1562
1563                         data_page = f2fs_get_read_data_page(inode,
1564                                                 start_bidx, REQ_RAHEAD, true);
1565                         f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1566                         if (IS_ERR(data_page)) {
1567                                 iput(inode);
1568                                 continue;
1569                         }
1570
1571                         f2fs_put_page(data_page, 0);
1572                         add_gc_inode(gc_list, inode);
1573                         continue;
1574                 }
1575
1576                 /* phase 4 */
1577                 inode = find_gc_inode(gc_list, dni.ino);
1578                 if (inode) {
1579                         struct f2fs_inode_info *fi = F2FS_I(inode);
1580                         bool locked = false;
1581                         int err;
1582
1583                         if (S_ISREG(inode->i_mode)) {
1584                                 if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[READ])) {
1585                                         sbi->skipped_gc_rwsem++;
1586                                         continue;
1587                                 }
1588                                 if (!f2fs_down_write_trylock(
1589                                                 &fi->i_gc_rwsem[WRITE])) {
1590                                         sbi->skipped_gc_rwsem++;
1591                                         f2fs_up_write(&fi->i_gc_rwsem[READ]);
1592                                         continue;
1593                                 }
1594                                 locked = true;
1595
1596                                 /* wait for all inflight aio data */
1597                                 inode_dio_wait(inode);
1598                         }
1599
1600                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1601                                                                 + ofs_in_node;
1602                         if (f2fs_post_read_required(inode))
1603                                 err = move_data_block(inode, start_bidx,
1604                                                         gc_type, segno, off);
1605                         else
1606                                 err = move_data_page(inode, start_bidx, gc_type,
1607                                                                 segno, off);
1608
1609                         if (!err && (gc_type == FG_GC ||
1610                                         f2fs_post_read_required(inode)))
1611                                 submitted++;
1612
1613                         if (locked) {
1614                                 f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1615                                 f2fs_up_write(&fi->i_gc_rwsem[READ]);
1616                         }
1617
1618                         stat_inc_data_blk_count(sbi, 1, gc_type);
1619                 }
1620         }
1621
1622         if (++phase < 5)
1623                 goto next_step;
1624
1625         return submitted;
1626 }
1627
1628 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1629                         int gc_type)
1630 {
1631         struct sit_info *sit_i = SIT_I(sbi);
1632         int ret;
1633
1634         down_write(&sit_i->sentry_lock);
1635         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1636                                               NO_CHECK_TYPE, LFS, 0);
1637         up_write(&sit_i->sentry_lock);
1638         return ret;
1639 }
1640
1641 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1642                                 unsigned int start_segno,
1643                                 struct gc_inode_list *gc_list, int gc_type,
1644                                 bool force_migrate)
1645 {
1646         struct page *sum_page;
1647         struct f2fs_summary_block *sum;
1648         struct blk_plug plug;
1649         unsigned int segno = start_segno;
1650         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1651         int seg_freed = 0, migrated = 0;
1652         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1653                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1654         int submitted = 0;
1655
1656         if (__is_large_section(sbi))
1657                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1658
1659         /*
1660          * zone-capacity can be less than zone-size in zoned devices,
1661          * resulting in less than expected usable segments in the zone,
1662          * calculate the end segno in the zone which can be garbage collected
1663          */
1664         if (f2fs_sb_has_blkzoned(sbi))
1665                 end_segno -= sbi->segs_per_sec -
1666                                         f2fs_usable_segs_in_sec(sbi, segno);
1667
1668         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1669
1670         /* readahead multi ssa blocks those have contiguous address */
1671         if (__is_large_section(sbi))
1672                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1673                                         end_segno - segno, META_SSA, true);
1674
1675         /* reference all summary page */
1676         while (segno < end_segno) {
1677                 sum_page = f2fs_get_sum_page(sbi, segno++);
1678                 if (IS_ERR(sum_page)) {
1679                         int err = PTR_ERR(sum_page);
1680
1681                         end_segno = segno - 1;
1682                         for (segno = start_segno; segno < end_segno; segno++) {
1683                                 sum_page = find_get_page(META_MAPPING(sbi),
1684                                                 GET_SUM_BLOCK(sbi, segno));
1685                                 f2fs_put_page(sum_page, 0);
1686                                 f2fs_put_page(sum_page, 0);
1687                         }
1688                         return err;
1689                 }
1690                 unlock_page(sum_page);
1691         }
1692
1693         blk_start_plug(&plug);
1694
1695         for (segno = start_segno; segno < end_segno; segno++) {
1696
1697                 /* find segment summary of victim */
1698                 sum_page = find_get_page(META_MAPPING(sbi),
1699                                         GET_SUM_BLOCK(sbi, segno));
1700                 f2fs_put_page(sum_page, 0);
1701
1702                 if (get_valid_blocks(sbi, segno, false) == 0)
1703                         goto freed;
1704                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1705                                 migrated >= sbi->migration_granularity)
1706                         goto skip;
1707                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1708                         goto skip;
1709
1710                 sum = page_address(sum_page);
1711                 if (type != GET_SUM_TYPE((&sum->footer))) {
1712                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1713                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1714                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1715                         f2fs_stop_checkpoint(sbi, false);
1716                         goto skip;
1717                 }
1718
1719                 /*
1720                  * this is to avoid deadlock:
1721                  * - lock_page(sum_page)         - f2fs_replace_block
1722                  *  - check_valid_map()            - down_write(sentry_lock)
1723                  *   - down_read(sentry_lock)     - change_curseg()
1724                  *                                  - lock_page(sum_page)
1725                  */
1726                 if (type == SUM_TYPE_NODE)
1727                         submitted += gc_node_segment(sbi, sum->entries, segno,
1728                                                                 gc_type);
1729                 else
1730                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1731                                                         segno, gc_type,
1732                                                         force_migrate);
1733
1734                 stat_inc_seg_count(sbi, type, gc_type);
1735                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1736                 migrated++;
1737
1738 freed:
1739                 if (gc_type == FG_GC &&
1740                                 get_valid_blocks(sbi, segno, false) == 0)
1741                         seg_freed++;
1742
1743                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1744                         sbi->next_victim_seg[gc_type] = segno + 1;
1745 skip:
1746                 f2fs_put_page(sum_page, 0);
1747         }
1748
1749         if (submitted)
1750                 f2fs_submit_merged_write(sbi,
1751                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1752
1753         blk_finish_plug(&plug);
1754
1755         stat_inc_call_count(sbi->stat_info);
1756
1757         return seg_freed;
1758 }
1759
1760 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1761 {
1762         int gc_type = gc_control->init_gc_type;
1763         unsigned int segno = gc_control->victim_segno;
1764         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1765         int ret = 0;
1766         struct cp_control cpc;
1767         struct gc_inode_list gc_list = {
1768                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1769                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1770         };
1771         unsigned int skipped_round = 0, round = 0;
1772
1773         trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1774                                 gc_control->nr_free_secs,
1775                                 get_pages(sbi, F2FS_DIRTY_NODES),
1776                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1777                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1778                                 free_sections(sbi),
1779                                 free_segments(sbi),
1780                                 reserved_segments(sbi),
1781                                 prefree_segments(sbi));
1782
1783         cpc.reason = __get_cp_reason(sbi);
1784         sbi->skipped_gc_rwsem = 0;
1785 gc_more:
1786         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1787                 ret = -EINVAL;
1788                 goto stop;
1789         }
1790         if (unlikely(f2fs_cp_error(sbi))) {
1791                 ret = -EIO;
1792                 goto stop;
1793         }
1794
1795         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1796                 /*
1797                  * For example, if there are many prefree_segments below given
1798                  * threshold, we can make them free by checkpoint. Then, we
1799                  * secure free segments which doesn't need fggc any more.
1800                  */
1801                 if (prefree_segments(sbi)) {
1802                         ret = f2fs_write_checkpoint(sbi, &cpc);
1803                         if (ret)
1804                                 goto stop;
1805                 }
1806                 if (has_not_enough_free_secs(sbi, 0, 0))
1807                         gc_type = FG_GC;
1808         }
1809
1810         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1811         if (gc_type == BG_GC && gc_control->no_bg_gc) {
1812                 ret = -EINVAL;
1813                 goto stop;
1814         }
1815 retry:
1816         ret = __get_victim(sbi, &segno, gc_type);
1817         if (ret) {
1818                 /* allow to search victim from sections has pinned data */
1819                 if (ret == -ENODATA && gc_type == FG_GC &&
1820                                 f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1821                         f2fs_unpin_all_sections(sbi, false);
1822                         goto retry;
1823                 }
1824                 goto stop;
1825         }
1826
1827         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1828                                 gc_control->should_migrate_blocks);
1829         total_freed += seg_freed;
1830
1831         if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1832                 sec_freed++;
1833
1834         if (gc_type == FG_GC)
1835                 sbi->cur_victim_sec = NULL_SEGNO;
1836
1837         if (gc_control->init_gc_type == FG_GC ||
1838             !has_not_enough_free_secs(sbi,
1839                                 (gc_type == FG_GC) ? sec_freed : 0, 0)) {
1840                 if (gc_type == FG_GC && sec_freed < gc_control->nr_free_secs)
1841                         goto go_gc_more;
1842                 goto stop;
1843         }
1844
1845         /* FG_GC stops GC by skip_count */
1846         if (gc_type == FG_GC) {
1847                 if (sbi->skipped_gc_rwsem)
1848                         skipped_round++;
1849                 round++;
1850                 if (skipped_round > MAX_SKIP_GC_COUNT &&
1851                                 skipped_round * 2 >= round) {
1852                         ret = f2fs_write_checkpoint(sbi, &cpc);
1853                         goto stop;
1854                 }
1855         }
1856
1857         /* Write checkpoint to reclaim prefree segments */
1858         if (free_sections(sbi) < NR_CURSEG_PERSIST_TYPE &&
1859                                 prefree_segments(sbi)) {
1860                 ret = f2fs_write_checkpoint(sbi, &cpc);
1861                 if (ret)
1862                         goto stop;
1863         }
1864 go_gc_more:
1865         segno = NULL_SEGNO;
1866         goto gc_more;
1867
1868 stop:
1869         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1870         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1871
1872         if (gc_type == FG_GC)
1873                 f2fs_unpin_all_sections(sbi, true);
1874
1875         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1876                                 get_pages(sbi, F2FS_DIRTY_NODES),
1877                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1878                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1879                                 free_sections(sbi),
1880                                 free_segments(sbi),
1881                                 reserved_segments(sbi),
1882                                 prefree_segments(sbi));
1883
1884         f2fs_up_write(&sbi->gc_lock);
1885
1886         put_gc_inode(&gc_list);
1887
1888         if (gc_control->err_gc_skipped && !ret)
1889                 ret = sec_freed ? 0 : -EAGAIN;
1890         return ret;
1891 }
1892
1893 int __init f2fs_create_garbage_collection_cache(void)
1894 {
1895         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1896                                         sizeof(struct victim_entry));
1897         if (!victim_entry_slab)
1898                 return -ENOMEM;
1899         return 0;
1900 }
1901
1902 void f2fs_destroy_garbage_collection_cache(void)
1903 {
1904         kmem_cache_destroy(victim_entry_slab);
1905 }
1906
1907 static void init_atgc_management(struct f2fs_sb_info *sbi)
1908 {
1909         struct atgc_management *am = &sbi->am;
1910
1911         if (test_opt(sbi, ATGC) &&
1912                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1913                 am->atgc_enabled = true;
1914
1915         am->root = RB_ROOT_CACHED;
1916         INIT_LIST_HEAD(&am->victim_list);
1917         am->victim_count = 0;
1918
1919         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1920         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1921         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1922         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1923 }
1924
1925 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1926 {
1927         DIRTY_I(sbi)->v_ops = &default_v_ops;
1928
1929         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1930
1931         /* give warm/cold data area from slower device */
1932         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1933                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1934                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1935
1936         init_atgc_management(sbi);
1937 }
1938
1939 static int free_segment_range(struct f2fs_sb_info *sbi,
1940                                 unsigned int secs, bool gc_only)
1941 {
1942         unsigned int segno, next_inuse, start, end;
1943         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1944         int gc_mode, gc_type;
1945         int err = 0;
1946         int type;
1947
1948         /* Force block allocation for GC */
1949         MAIN_SECS(sbi) -= secs;
1950         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1951         end = MAIN_SEGS(sbi) - 1;
1952
1953         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1954         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1955                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1956                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1957
1958         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1959                 if (sbi->next_victim_seg[gc_type] >= start)
1960                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1961         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1962
1963         /* Move out cursegs from the target range */
1964         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1965                 f2fs_allocate_segment_for_resize(sbi, type, start, end);
1966
1967         /* do GC to move out valid blocks in the range */
1968         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1969                 struct gc_inode_list gc_list = {
1970                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1971                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1972                 };
1973
1974                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1975                 put_gc_inode(&gc_list);
1976
1977                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1978                         err = -EAGAIN;
1979                         goto out;
1980                 }
1981                 if (fatal_signal_pending(current)) {
1982                         err = -ERESTARTSYS;
1983                         goto out;
1984                 }
1985         }
1986         if (gc_only)
1987                 goto out;
1988
1989         err = f2fs_write_checkpoint(sbi, &cpc);
1990         if (err)
1991                 goto out;
1992
1993         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1994         if (next_inuse <= end) {
1995                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1996                          next_inuse);
1997                 f2fs_bug_on(sbi, 1);
1998         }
1999 out:
2000         MAIN_SECS(sbi) += secs;
2001         return err;
2002 }
2003
2004 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2005 {
2006         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2007         int section_count;
2008         int segment_count;
2009         int segment_count_main;
2010         long long block_count;
2011         int segs = secs * sbi->segs_per_sec;
2012
2013         f2fs_down_write(&sbi->sb_lock);
2014
2015         section_count = le32_to_cpu(raw_sb->section_count);
2016         segment_count = le32_to_cpu(raw_sb->segment_count);
2017         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2018         block_count = le64_to_cpu(raw_sb->block_count);
2019
2020         raw_sb->section_count = cpu_to_le32(section_count + secs);
2021         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2022         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2023         raw_sb->block_count = cpu_to_le64(block_count +
2024                                         (long long)segs * sbi->blocks_per_seg);
2025         if (f2fs_is_multi_device(sbi)) {
2026                 int last_dev = sbi->s_ndevs - 1;
2027                 int dev_segs =
2028                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2029
2030                 raw_sb->devs[last_dev].total_segments =
2031                                                 cpu_to_le32(dev_segs + segs);
2032         }
2033
2034         f2fs_up_write(&sbi->sb_lock);
2035 }
2036
2037 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2038 {
2039         int segs = secs * sbi->segs_per_sec;
2040         long long blks = (long long)segs * sbi->blocks_per_seg;
2041         long long user_block_count =
2042                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2043
2044         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2045         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2046         MAIN_SECS(sbi) += secs;
2047         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2048         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2049         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2050
2051         if (f2fs_is_multi_device(sbi)) {
2052                 int last_dev = sbi->s_ndevs - 1;
2053
2054                 FDEV(last_dev).total_segments =
2055                                 (int)FDEV(last_dev).total_segments + segs;
2056                 FDEV(last_dev).end_blk =
2057                                 (long long)FDEV(last_dev).end_blk + blks;
2058 #ifdef CONFIG_BLK_DEV_ZONED
2059                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
2060                                         (int)(blks >> sbi->log_blocks_per_blkz);
2061 #endif
2062         }
2063 }
2064
2065 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
2066 {
2067         __u64 old_block_count, shrunk_blocks;
2068         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2069         unsigned int secs;
2070         int err = 0;
2071         __u32 rem;
2072
2073         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2074         if (block_count > old_block_count)
2075                 return -EINVAL;
2076
2077         if (f2fs_is_multi_device(sbi)) {
2078                 int last_dev = sbi->s_ndevs - 1;
2079                 __u64 last_segs = FDEV(last_dev).total_segments;
2080
2081                 if (block_count + last_segs * sbi->blocks_per_seg <=
2082                                                                 old_block_count)
2083                         return -EINVAL;
2084         }
2085
2086         /* new fs size should align to section size */
2087         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2088         if (rem)
2089                 return -EINVAL;
2090
2091         if (block_count == old_block_count)
2092                 return 0;
2093
2094         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2095                 f2fs_err(sbi, "Should run fsck to repair first.");
2096                 return -EFSCORRUPTED;
2097         }
2098
2099         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2100                 f2fs_err(sbi, "Checkpoint should be enabled.");
2101                 return -EINVAL;
2102         }
2103
2104         shrunk_blocks = old_block_count - block_count;
2105         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2106
2107         /* stop other GC */
2108         if (!f2fs_down_write_trylock(&sbi->gc_lock))
2109                 return -EAGAIN;
2110
2111         /* stop CP to protect MAIN_SEC in free_segment_range */
2112         f2fs_lock_op(sbi);
2113
2114         spin_lock(&sbi->stat_lock);
2115         if (shrunk_blocks + valid_user_blocks(sbi) +
2116                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2117                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2118                 err = -ENOSPC;
2119         spin_unlock(&sbi->stat_lock);
2120
2121         if (err)
2122                 goto out_unlock;
2123
2124         err = free_segment_range(sbi, secs, true);
2125
2126 out_unlock:
2127         f2fs_unlock_op(sbi);
2128         f2fs_up_write(&sbi->gc_lock);
2129         if (err)
2130                 return err;
2131
2132         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2133
2134         freeze_super(sbi->sb);
2135         f2fs_down_write(&sbi->gc_lock);
2136         f2fs_down_write(&sbi->cp_global_sem);
2137
2138         spin_lock(&sbi->stat_lock);
2139         if (shrunk_blocks + valid_user_blocks(sbi) +
2140                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2141                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2142                 err = -ENOSPC;
2143         else
2144                 sbi->user_block_count -= shrunk_blocks;
2145         spin_unlock(&sbi->stat_lock);
2146         if (err)
2147                 goto out_err;
2148
2149         err = free_segment_range(sbi, secs, false);
2150         if (err)
2151                 goto recover_out;
2152
2153         update_sb_metadata(sbi, -secs);
2154
2155         err = f2fs_commit_super(sbi, false);
2156         if (err) {
2157                 update_sb_metadata(sbi, secs);
2158                 goto recover_out;
2159         }
2160
2161         update_fs_metadata(sbi, -secs);
2162         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2163         set_sbi_flag(sbi, SBI_IS_DIRTY);
2164
2165         err = f2fs_write_checkpoint(sbi, &cpc);
2166         if (err) {
2167                 update_fs_metadata(sbi, secs);
2168                 update_sb_metadata(sbi, secs);
2169                 f2fs_commit_super(sbi, false);
2170         }
2171 recover_out:
2172         if (err) {
2173                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2174                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2175
2176                 spin_lock(&sbi->stat_lock);
2177                 sbi->user_block_count += shrunk_blocks;
2178                 spin_unlock(&sbi->stat_lock);
2179         }
2180 out_err:
2181         f2fs_up_write(&sbi->cp_global_sem);
2182         f2fs_up_write(&sbi->gc_lock);
2183         thaw_super(sbi->sb);
2184         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2185         return err;
2186 }