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
  39         wait_ms = gc_th->min_sleep_time;
  40
  41         set_freezable();
  42         do {
  43                 bool sync_mode, foreground = false;
  44
  45                 wait_event_interruptible_timeout(*wq,
  46                                 kthread_should_stop() || freezing(current) ||
  47                                 waitqueue_active(fggc_wq) ||
  48                                 gc_th->gc_wake,
  49                                 msecs_to_jiffies(wait_ms));
  50
  51                 if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
  52                         foreground = true;
  53
  54                 /* give it a try one time */
  55                 if (gc_th->gc_wake)
  56                         gc_th->gc_wake = 0;
  57
  58                 if (try_to_freeze()) {
  59                         stat_other_skip_bggc_count(sbi);
  60                         continue;
  61                 }
  62                 if (kthread_should_stop())
  63                         break;
  64
  65                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  66                         increase_sleep_time(gc_th, &wait_ms);
  67                         stat_other_skip_bggc_count(sbi);
  68                         continue;
  69                 }
  70
  71                 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  72                         f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  73                         f2fs_stop_checkpoint(sbi, false);
  74                 }
  75
  76                 if (!sb_start_write_trylock(sbi->sb)) {
  77                         stat_other_skip_bggc_count(sbi);
  78                         continue;
  79                 }
  80
  81                 /*
  82                  * [GC triggering condition]
  83                  * 0. GC is not conducted currently.
  84                  * 1. There are enough dirty segments.
  85                  * 2. IO subsystem is idle by checking the # of writeback pages.
  86                  * 3. IO subsystem is idle by checking the # of requests in
  87                  *    bdev's request list.
  88                  *
  89                  * Note) We have to avoid triggering GCs frequently.
  90                  * Because it is possible that some segments can be
  91                  * invalidated soon after by user update or deletion.
  92                  * So, I'd like to wait some time to collect dirty segments.
  93                  */
  94                 if (sbi->gc_mode == GC_URGENT_HIGH) {
  95                         spin_lock(&sbi->gc_urgent_high_lock);
  96                         if (sbi->gc_urgent_high_limited) {
  97                                 if (!sbi->gc_urgent_high_remaining) {
  98                                         sbi->gc_urgent_high_limited = false;
  99                                         spin_unlock(&sbi->gc_urgent_high_lock);
 100                                         sbi->gc_mode = GC_NORMAL;
 101                                         continue;
 102                                 }
 103                                 sbi->gc_urgent_high_remaining--;
 104                         }
 105                         spin_unlock(&sbi->gc_urgent_high_lock);
 106
 107                         wait_ms = gc_th->urgent_sleep_time;
 108                         down_write(&sbi->gc_lock);
 109                         goto do_gc;
 110                 }
 111
 112                 if (foreground) {
 113                         down_write(&sbi->gc_lock);
 114                         goto do_gc;
 115                 } else if (!down_write_trylock(&sbi->gc_lock)) {
 116                         stat_other_skip_bggc_count(sbi);
 117                         goto next;
 118                 }
 119
 120                 if (!is_idle(sbi, GC_TIME)) {
 121                         increase_sleep_time(gc_th, &wait_ms);
 122                         up_write(&sbi->gc_lock);
 123                         stat_io_skip_bggc_count(sbi);
 124                         goto next;
 125                 }
 126
 127                 if (has_enough_invalid_blocks(sbi))
 128                         decrease_sleep_time(gc_th, &wait_ms);
 129                 else
 130                         increase_sleep_time(gc_th, &wait_ms);
 131 do_gc:
 132                 if (!foreground)
 133                         stat_inc_bggc_count(sbi->stat_info);
 134
 135                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 136
 137                 /* foreground GC was been triggered via f2fs_balance_fs() */
 138                 if (foreground)
 139                         sync_mode = false;
 140
 141                 /* if return value is not zero, no victim was selected */
 142                 if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
 143                         wait_ms = gc_th->no_gc_sleep_time;
 144
 145                 if (foreground)
 146                         wake_up_all(&gc_th->fggc_wq);
 147
 148                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 149                                 prefree_segments(sbi), free_segments(sbi));
 150
 151                 /* balancing f2fs's metadata periodically */
 152                 f2fs_balance_fs_bg(sbi, true);
 153 next:
 154                 sb_end_write(sbi->sb);
 155
 156         } while (!kthread_should_stop());
 157         return 0;
 158 }
 159
 160 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 161 {
 162         struct f2fs_gc_kthread *gc_th;
 163         dev_t dev = sbi->sb->s_bdev->bd_dev;
 164         int err = 0;
 165
 166         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 167         if (!gc_th) {
 168                 err = -ENOMEM;
 169                 goto out;
 170         }
 171
 172         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 173         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 174         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 175         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 176
 177         gc_th->gc_wake = 0;
 178
 179         sbi->gc_thread = gc_th;
 180         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 181         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 182         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 183                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 184         if (IS_ERR(gc_th->f2fs_gc_task)) {
 185                 err = PTR_ERR(gc_th->f2fs_gc_task);
 186                 kfree(gc_th);
 187                 sbi->gc_thread = NULL;
 188         }
 189 out:
 190         return err;
 191 }
 192
 193 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 194 {
 195         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 196
 197         if (!gc_th)
 198                 return;
 199         kthread_stop(gc_th->f2fs_gc_task);
 200         wake_up_all(&gc_th->fggc_wq);
 201         kfree(gc_th);
 202         sbi->gc_thread = NULL;
 203 }
 204
 205 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 206 {
 207         int gc_mode;
 208
 209         if (gc_type == BG_GC) {
 210                 if (sbi->am.atgc_enabled)
 211                         gc_mode = GC_AT;
 212                 else
 213                         gc_mode = GC_CB;
 214         } else {
 215                 gc_mode = GC_GREEDY;
 216         }
 217
 218         switch (sbi->gc_mode) {
 219         case GC_IDLE_CB:
 220                 gc_mode = GC_CB;
 221                 break;
 222         case GC_IDLE_GREEDY:
 223         case GC_URGENT_HIGH:
 224                 gc_mode = GC_GREEDY;
 225                 break;
 226         case GC_IDLE_AT:
 227                 gc_mode = GC_AT;
 228                 break;
 229         }
 230
 231         return gc_mode;
 232 }
 233
 234 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 235                         int type, struct victim_sel_policy *p)
 236 {
 237         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 238
 239         if (p->alloc_mode == SSR) {
 240                 p->gc_mode = GC_GREEDY;
 241                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 242                 p->max_search = dirty_i->nr_dirty[type];
 243                 p->ofs_unit = 1;
 244         } else if (p->alloc_mode == AT_SSR) {
 245                 p->gc_mode = GC_GREEDY;
 246                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 247                 p->max_search = dirty_i->nr_dirty[type];
 248                 p->ofs_unit = 1;
 249         } else {
 250                 p->gc_mode = select_gc_type(sbi, gc_type);
 251                 p->ofs_unit = sbi->segs_per_sec;
 252                 if (__is_large_section(sbi)) {
 253                         p->dirty_bitmap = dirty_i->dirty_secmap;
 254                         p->max_search = count_bits(p->dirty_bitmap,
 255                                                 0, MAIN_SECS(sbi));
 256                 } else {
 257                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 258                         p->max_search = dirty_i->nr_dirty[DIRTY];
 259                 }
 260         }
 261
 262         /*
 263          * adjust candidates range, should select all dirty segments for
 264          * foreground GC and urgent GC cases.
 265          */
 266         if (gc_type != FG_GC &&
 267                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 268                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 269                         p->max_search > sbi->max_victim_search)
 270                 p->max_search = sbi->max_victim_search;
 271
 272         /* let's select beginning hot/small space first in no_heap mode*/
 273         if (f2fs_need_rand_seg(sbi))
 274                 p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
 275         else if (test_opt(sbi, NOHEAP) &&
 276                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 277                 p->offset = 0;
 278         else
 279                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 280 }
 281
 282 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 283                                 struct victim_sel_policy *p)
 284 {
 285         /* SSR allocates in a segment unit */
 286         if (p->alloc_mode == SSR)
 287                 return sbi->blocks_per_seg;
 288         else if (p->alloc_mode == AT_SSR)
 289                 return UINT_MAX;
 290
 291         /* LFS */
 292         if (p->gc_mode == GC_GREEDY)
 293                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 294         else if (p->gc_mode == GC_CB)
 295                 return UINT_MAX;
 296         else if (p->gc_mode == GC_AT)
 297                 return UINT_MAX;
 298         else /* No other gc_mode */
 299                 return 0;
 300 }
 301
 302 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 303 {
 304         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 305         unsigned int secno;
 306
 307         /*
 308          * If the gc_type is FG_GC, we can select victim segments
 309          * selected by background GC before.
 310          * Those segments guarantee they have small valid blocks.
 311          */
 312         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 313                 if (sec_usage_check(sbi, secno))
 314                         continue;
 315                 clear_bit(secno, dirty_i->victim_secmap);
 316                 return GET_SEG_FROM_SEC(sbi, secno);
 317         }
 318         return NULL_SEGNO;
 319 }
 320
 321 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 322 {
 323         struct sit_info *sit_i = SIT_I(sbi);
 324         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 325         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 326         unsigned long long mtime = 0;
 327         unsigned int vblocks;
 328         unsigned char age = 0;
 329         unsigned char u;
 330         unsigned int i;
 331         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 332
 333         for (i = 0; i < usable_segs_per_sec; i++)
 334                 mtime += get_seg_entry(sbi, start + i)->mtime;
 335         vblocks = get_valid_blocks(sbi, segno, true);
 336
 337         mtime = div_u64(mtime, usable_segs_per_sec);
 338         vblocks = div_u64(vblocks, usable_segs_per_sec);
 339
 340         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 341
 342         /* Handle if the system time has changed by the user */
 343         if (mtime < sit_i->min_mtime)
 344                 sit_i->min_mtime = mtime;
 345         if (mtime > sit_i->max_mtime)
 346                 sit_i->max_mtime = mtime;
 347         if (sit_i->max_mtime != sit_i->min_mtime)
 348                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 349                                 sit_i->max_mtime - sit_i->min_mtime);
 350
 351         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 352 }
 353
 354 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 355                         unsigned int segno, struct victim_sel_policy *p)
 356 {
 357         if (p->alloc_mode == SSR)
 358                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 359
 360         /* alloc_mode == LFS */
 361         if (p->gc_mode == GC_GREEDY)
 362                 return get_valid_blocks(sbi, segno, true);
 363         else if (p->gc_mode == GC_CB)
 364                 return get_cb_cost(sbi, segno);
 365
 366         f2fs_bug_on(sbi, 1);
 367         return 0;
 368 }
 369
 370 static unsigned int count_bits(const unsigned long *addr,
 371                                 unsigned int offset, unsigned int len)
 372 {
 373         unsigned int end = offset + len, sum = 0;
 374
 375         while (offset < end) {
 376                 if (test_bit(offset++, addr))
 377                         ++sum;
 378         }
 379         return sum;
 380 }
 381
 382 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 383                                 unsigned long long mtime, unsigned int segno,
 384                                 struct rb_node *parent, struct rb_node **p,
 385                                 bool left_most)
 386 {
 387         struct atgc_management *am = &sbi->am;
 388         struct victim_entry *ve;
 389
 390         ve =  f2fs_kmem_cache_alloc(victim_entry_slab,
 391                                 GFP_NOFS, true, NULL);
 392
 393         ve->mtime = mtime;
 394         ve->segno = segno;
 395
 396         rb_link_node(&ve->rb_node, parent, p);
 397         rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 398
 399         list_add_tail(&ve->list, &am->victim_list);
 400
 401         am->victim_count++;
 402
 403         return ve;
 404 }
 405
 406 static void insert_victim_entry(struct f2fs_sb_info *sbi,
 407                                 unsigned long long mtime, unsigned int segno)
 408 {
 409         struct atgc_management *am = &sbi->am;
 410         struct rb_node **p;
 411         struct rb_node *parent = NULL;
 412         bool left_most = true;
 413
 414         p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 415         attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 416 }
 417
 418 static void add_victim_entry(struct f2fs_sb_info *sbi,
 419                                 struct victim_sel_policy *p, unsigned int segno)
 420 {
 421         struct sit_info *sit_i = SIT_I(sbi);
 422         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 423         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 424         unsigned long long mtime = 0;
 425         unsigned int i;
 426
 427         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 428                 if (p->gc_mode == GC_AT &&
 429                         get_valid_blocks(sbi, segno, true) == 0)
 430                         return;
 431         }
 432
 433         for (i = 0; i < sbi->segs_per_sec; i++)
 434                 mtime += get_seg_entry(sbi, start + i)->mtime;
 435         mtime = div_u64(mtime, sbi->segs_per_sec);
 436
 437         /* Handle if the system time has changed by the user */
 438         if (mtime < sit_i->min_mtime)
 439                 sit_i->min_mtime = mtime;
 440         if (mtime > sit_i->max_mtime)
 441                 sit_i->max_mtime = mtime;
 442         if (mtime < sit_i->dirty_min_mtime)
 443                 sit_i->dirty_min_mtime = mtime;
 444         if (mtime > sit_i->dirty_max_mtime)
 445                 sit_i->dirty_max_mtime = mtime;
 446
 447         /* don't choose young section as candidate */
 448         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 449                 return;
 450
 451         insert_victim_entry(sbi, mtime, segno);
 452 }
 453
 454 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 455                                                 struct victim_sel_policy *p)
 456 {
 457         struct atgc_management *am = &sbi->am;
 458         struct rb_node *parent = NULL;
 459         bool left_most;
 460
 461         f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 462
 463         return parent;
 464 }
 465
 466 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 467                                                 struct victim_sel_policy *p)
 468 {
 469         struct sit_info *sit_i = SIT_I(sbi);
 470         struct atgc_management *am = &sbi->am;
 471         struct rb_root_cached *root = &am->root;
 472         struct rb_node *node;
 473         struct rb_entry *re;
 474         struct victim_entry *ve;
 475         unsigned long long total_time;
 476         unsigned long long age, u, accu;
 477         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 478         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 479         unsigned int sec_blocks = BLKS_PER_SEC(sbi);
 480         unsigned int vblocks;
 481         unsigned int dirty_threshold = max(am->max_candidate_count,
 482                                         am->candidate_ratio *
 483                                         am->victim_count / 100);
 484         unsigned int age_weight = am->age_weight;
 485         unsigned int cost;
 486         unsigned int iter = 0;
 487
 488         if (max_mtime < min_mtime)
 489                 return;
 490
 491         max_mtime += 1;
 492         total_time = max_mtime - min_mtime;
 493
 494         accu = div64_u64(ULLONG_MAX, total_time);
 495         accu = min_t(unsigned long long, div_u64(accu, 100),
 496                                         DEFAULT_ACCURACY_CLASS);
 497
 498         node = rb_first_cached(root);
 499 next:
 500         re = rb_entry_safe(node, struct rb_entry, rb_node);
 501         if (!re)
 502                 return;
 503
 504         ve = (struct victim_entry *)re;
 505
 506         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 507                 goto skip;
 508
 509         /* age = 10000 * x% * 60 */
 510         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 511                                                                 age_weight;
 512
 513         vblocks = get_valid_blocks(sbi, ve->segno, true);
 514         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 515
 516         /* u = 10000 * x% * 40 */
 517         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 518                                                         (100 - age_weight);
 519
 520         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 521
 522         cost = UINT_MAX - (age + u);
 523         iter++;
 524
 525         if (cost < p->min_cost ||
 526                         (cost == p->min_cost && age > p->oldest_age)) {
 527                 p->min_cost = cost;
 528                 p->oldest_age = age;
 529                 p->min_segno = ve->segno;
 530         }
 531 skip:
 532         if (iter < dirty_threshold) {
 533                 node = rb_next(node);
 534                 goto next;
 535         }
 536 }
 537
 538 /*
 539  * select candidates around source section in range of
 540  * [target - dirty_threshold, target + dirty_threshold]
 541  */
 542 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 543                                                 struct victim_sel_policy *p)
 544 {
 545         struct sit_info *sit_i = SIT_I(sbi);
 546         struct atgc_management *am = &sbi->am;
 547         struct rb_node *node;
 548         struct rb_entry *re;
 549         struct victim_entry *ve;
 550         unsigned long long age;
 551         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 552         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 553         unsigned int seg_blocks = sbi->blocks_per_seg;
 554         unsigned int vblocks;
 555         unsigned int dirty_threshold = max(am->max_candidate_count,
 556                                         am->candidate_ratio *
 557                                         am->victim_count / 100);
 558         unsigned int cost;
 559         unsigned int iter = 0;
 560         int stage = 0;
 561
 562         if (max_mtime < min_mtime)
 563                 return;
 564         max_mtime += 1;
 565 next_stage:
 566         node = lookup_central_victim(sbi, p);
 567 next_node:
 568         re = rb_entry_safe(node, struct rb_entry, rb_node);
 569         if (!re) {
 570                 if (stage == 0)
 571                         goto skip_stage;
 572                 return;
 573         }
 574
 575         ve = (struct victim_entry *)re;
 576
 577         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 578                 goto skip_node;
 579
 580         age = max_mtime - ve->mtime;
 581
 582         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 583         f2fs_bug_on(sbi, !vblocks);
 584
 585         /* rare case */
 586         if (vblocks == seg_blocks)
 587                 goto skip_node;
 588
 589         iter++;
 590
 591         age = max_mtime - abs(p->age - age);
 592         cost = UINT_MAX - vblocks;
 593
 594         if (cost < p->min_cost ||
 595                         (cost == p->min_cost && age > p->oldest_age)) {
 596                 p->min_cost = cost;
 597                 p->oldest_age = age;
 598                 p->min_segno = ve->segno;
 599         }
 600 skip_node:
 601         if (iter < dirty_threshold) {
 602                 if (stage == 0)
 603                         node = rb_prev(node);
 604                 else if (stage == 1)
 605                         node = rb_next(node);
 606                 goto next_node;
 607         }
 608 skip_stage:
 609         if (stage < 1) {
 610                 stage++;
 611                 iter = 0;
 612                 goto next_stage;
 613         }
 614 }
 615 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 616                                                 struct victim_sel_policy *p)
 617 {
 618         f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 619                                                 &sbi->am.root, true));
 620
 621         if (p->gc_mode == GC_AT)
 622                 atgc_lookup_victim(sbi, p);
 623         else if (p->alloc_mode == AT_SSR)
 624                 atssr_lookup_victim(sbi, p);
 625         else
 626                 f2fs_bug_on(sbi, 1);
 627 }
 628
 629 static void release_victim_entry(struct f2fs_sb_info *sbi)
 630 {
 631         struct atgc_management *am = &sbi->am;
 632         struct victim_entry *ve, *tmp;
 633
 634         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 635                 list_del(&ve->list);
 636                 kmem_cache_free(victim_entry_slab, ve);
 637                 am->victim_count--;
 638         }
 639
 640         am->root = RB_ROOT_CACHED;
 641
 642         f2fs_bug_on(sbi, am->victim_count);
 643         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 644 }
 645
 646 /*
 647  * This function is called from two paths.
 648  * One is garbage collection and the other is SSR segment selection.
 649  * When it is called during GC, it just gets a victim segment
 650  * and it does not remove it from dirty seglist.
 651  * When it is called from SSR segment selection, it finds a segment
 652  * which has minimum valid blocks and removes it from dirty seglist.
 653  */
 654 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 655                         unsigned int *result, int gc_type, int type,
 656                         char alloc_mode, unsigned long long age)
 657 {
 658         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 659         struct sit_info *sm = SIT_I(sbi);
 660         struct victim_sel_policy p;
 661         unsigned int secno, last_victim;
 662         unsigned int last_segment;
 663         unsigned int nsearched;
 664         bool is_atgc;
 665         int ret = 0;
 666
 667         mutex_lock(&dirty_i->seglist_lock);
 668         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 669
 670         p.alloc_mode = alloc_mode;
 671         p.age = age;
 672         p.age_threshold = sbi->am.age_threshold;
 673
 674 retry:
 675         select_policy(sbi, gc_type, type, &p);
 676         p.min_segno = NULL_SEGNO;
 677         p.oldest_age = 0;
 678         p.min_cost = get_max_cost(sbi, &p);
 679
 680         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 681         nsearched = 0;
 682
 683         if (is_atgc)
 684                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 685
 686         if (*result != NULL_SEGNO) {
 687                 if (!get_valid_blocks(sbi, *result, false)) {
 688                         ret = -ENODATA;
 689                         goto out;
 690                 }
 691
 692                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 693                         ret = -EBUSY;
 694                 else
 695                         p.min_segno = *result;
 696                 goto out;
 697         }
 698
 699         ret = -ENODATA;
 700         if (p.max_search == 0)
 701                 goto out;
 702
 703         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 704                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 705                         p.min_segno = sbi->next_victim_seg[BG_GC];
 706                         *result = p.min_segno;
 707                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 708                         goto got_result;
 709                 }
 710                 if (gc_type == FG_GC &&
 711                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 712                         p.min_segno = sbi->next_victim_seg[FG_GC];
 713                         *result = p.min_segno;
 714                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 715                         goto got_result;
 716                 }
 717         }
 718
 719         last_victim = sm->last_victim[p.gc_mode];
 720         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 721                 p.min_segno = check_bg_victims(sbi);
 722                 if (p.min_segno != NULL_SEGNO)
 723                         goto got_it;
 724         }
 725
 726         while (1) {
 727                 unsigned long cost, *dirty_bitmap;
 728                 unsigned int unit_no, segno;
 729
 730                 dirty_bitmap = p.dirty_bitmap;
 731                 unit_no = find_next_bit(dirty_bitmap,
 732                                 last_segment / p.ofs_unit,
 733                                 p.offset / p.ofs_unit);
 734                 segno = unit_no * p.ofs_unit;
 735                 if (segno >= last_segment) {
 736                         if (sm->last_victim[p.gc_mode]) {
 737                                 last_segment =
 738                                         sm->last_victim[p.gc_mode];
 739                                 sm->last_victim[p.gc_mode] = 0;
 740                                 p.offset = 0;
 741                                 continue;
 742                         }
 743                         break;
 744                 }
 745
 746                 p.offset = segno + p.ofs_unit;
 747                 nsearched++;
 748
 749 #ifdef CONFIG_F2FS_CHECK_FS
 750                 /*
 751                  * skip selecting the invalid segno (that is failed due to block
 752                  * validity check failure during GC) to avoid endless GC loop in
 753                  * such cases.
 754                  */
 755                 if (test_bit(segno, sm->invalid_segmap))
 756                         goto next;
 757 #endif
 758
 759                 secno = GET_SEC_FROM_SEG(sbi, segno);
 760
 761                 if (sec_usage_check(sbi, secno))
 762                         goto next;
 763
 764                 /* Don't touch checkpointed data */
 765                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 766                         if (p.alloc_mode == LFS) {
 767                                 /*
 768                                  * LFS is set to find source section during GC.
 769                                  * The victim should have no checkpointed data.
 770                                  */
 771                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 772                                         goto next;
 773                         } else {
 774                                 /*
 775                                  * SSR | AT_SSR are set to find target segment
 776                                  * for writes which can be full by checkpointed
 777                                  * and newly written blocks.
 778                                  */
 779                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 780                                         goto next;
 781                         }
 782                 }
 783
 784                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 785                         goto next;
 786
 787                 if (is_atgc) {
 788                         add_victim_entry(sbi, &p, segno);
 789                         goto next;
 790                 }
 791
 792                 cost = get_gc_cost(sbi, segno, &p);
 793
 794                 if (p.min_cost > cost) {
 795                         p.min_segno = segno;
 796                         p.min_cost = cost;
 797                 }
 798 next:
 799                 if (nsearched >= p.max_search) {
 800                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 801                                 sm->last_victim[p.gc_mode] =
 802                                         last_victim + p.ofs_unit;
 803                         else
 804                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 805                         sm->last_victim[p.gc_mode] %=
 806                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 807                         break;
 808                 }
 809         }
 810
 811         /* get victim for GC_AT/AT_SSR */
 812         if (is_atgc) {
 813                 lookup_victim_by_age(sbi, &p);
 814                 release_victim_entry(sbi);
 815         }
 816
 817         if (is_atgc && p.min_segno == NULL_SEGNO &&
 818                         sm->elapsed_time < p.age_threshold) {
 819                 p.age_threshold = 0;
 820                 goto retry;
 821         }
 822
 823         if (p.min_segno != NULL_SEGNO) {
 824 got_it:
 825                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 826 got_result:
 827                 if (p.alloc_mode == LFS) {
 828                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 829                         if (gc_type == FG_GC)
 830                                 sbi->cur_victim_sec = secno;
 831                         else
 832                                 set_bit(secno, dirty_i->victim_secmap);
 833                 }
 834                 ret = 0;
 835
 836         }
 837 out:
 838         if (p.min_segno != NULL_SEGNO)
 839                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 840                                 sbi->cur_victim_sec,
 841                                 prefree_segments(sbi), free_segments(sbi));
 842         mutex_unlock(&dirty_i->seglist_lock);
 843
 844         return ret;
 845 }
 846
 847 static const struct victim_selection default_v_ops = {
 848         .get_victim = get_victim_by_default,
 849 };
 850
 851 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 852 {
 853         struct inode_entry *ie;
 854
 855         ie = radix_tree_lookup(&gc_list->iroot, ino);
 856         if (ie)
 857                 return ie->inode;
 858         return NULL;
 859 }
 860
 861 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 862 {
 863         struct inode_entry *new_ie;
 864
 865         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 866                 iput(inode);
 867                 return;
 868         }
 869         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 870                                         GFP_NOFS, true, NULL);
 871         new_ie->inode = inode;
 872
 873         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 874         list_add_tail(&new_ie->list, &gc_list->ilist);
 875 }
 876
 877 static void put_gc_inode(struct gc_inode_list *gc_list)
 878 {
 879         struct inode_entry *ie, *next_ie;
 880
 881         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 882                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 883                 iput(ie->inode);
 884                 list_del(&ie->list);
 885                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 886         }
 887 }
 888
 889 static int check_valid_map(struct f2fs_sb_info *sbi,
 890                                 unsigned int segno, int offset)
 891 {
 892         struct sit_info *sit_i = SIT_I(sbi);
 893         struct seg_entry *sentry;
 894         int ret;
 895
 896         down_read(&sit_i->sentry_lock);
 897         sentry = get_seg_entry(sbi, segno);
 898         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 899         up_read(&sit_i->sentry_lock);
 900         return ret;
 901 }
 902
 903 /*
 904  * This function compares node address got in summary with that in NAT.
 905  * On validity, copy that node with cold status, otherwise (invalid node)
 906  * ignore that.
 907  */
 908 static int gc_node_segment(struct f2fs_sb_info *sbi,
 909                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 910 {
 911         struct f2fs_summary *entry;
 912         block_t start_addr;
 913         int off;
 914         int phase = 0;
 915         bool fggc = (gc_type == FG_GC);
 916         int submitted = 0;
 917         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 918
 919         start_addr = START_BLOCK(sbi, segno);
 920
 921 next_step:
 922         entry = sum;
 923
 924         if (fggc && phase == 2)
 925                 atomic_inc(&sbi->wb_sync_req[NODE]);
 926
 927         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 928                 nid_t nid = le32_to_cpu(entry->nid);
 929                 struct page *node_page;
 930                 struct node_info ni;
 931                 int err;
 932
 933                 /* stop BG_GC if there is not enough free sections. */
 934                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 935                         return submitted;
 936
 937                 if (check_valid_map(sbi, segno, off) == 0)
 938                         continue;
 939
 940                 if (phase == 0) {
 941                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 942                                                         META_NAT, true);
 943                         continue;
 944                 }
 945
 946                 if (phase == 1) {
 947                         f2fs_ra_node_page(sbi, nid);
 948                         continue;
 949                 }
 950
 951                 /* phase == 2 */
 952                 node_page = f2fs_get_node_page(sbi, nid);
 953                 if (IS_ERR(node_page))
 954                         continue;
 955
 956                 /* block may become invalid during f2fs_get_node_page */
 957                 if (check_valid_map(sbi, segno, off) == 0) {
 958                         f2fs_put_page(node_page, 1);
 959                         continue;
 960                 }
 961
 962                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
 963                         f2fs_put_page(node_page, 1);
 964                         continue;
 965                 }
 966
 967                 if (ni.blk_addr != start_addr + off) {
 968                         f2fs_put_page(node_page, 1);
 969                         continue;
 970                 }
 971
 972                 err = f2fs_move_node_page(node_page, gc_type);
 973                 if (!err && gc_type == FG_GC)
 974                         submitted++;
 975                 stat_inc_node_blk_count(sbi, 1, gc_type);
 976         }
 977
 978         if (++phase < 3)
 979                 goto next_step;
 980
 981         if (fggc)
 982                 atomic_dec(&sbi->wb_sync_req[NODE]);
 983         return submitted;
 984 }
 985
 986 /*
 987  * Calculate start block index indicating the given node offset.
 988  * Be careful, caller should give this node offset only indicating direct node
 989  * blocks. If any node offsets, which point the other types of node blocks such
 990  * as indirect or double indirect node blocks, are given, it must be a caller's
 991  * bug.
 992  */
 993 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 994 {
 995         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 996         unsigned int bidx;
 997
 998         if (node_ofs == 0)
 999                 return 0;
1000
1001         if (node_ofs <= 2) {
1002                 bidx = node_ofs - 1;
1003         } else if (node_ofs <= indirect_blks) {
1004                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1005
1006                 bidx = node_ofs - 2 - dec;
1007         } else {
1008                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1009
1010                 bidx = node_ofs - 5 - dec;
1011         }
1012         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1013 }
1014
1015 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1016                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1017 {
1018         struct page *node_page;
1019         nid_t nid;
1020         unsigned int ofs_in_node;
1021         block_t source_blkaddr;
1022
1023         nid = le32_to_cpu(sum->nid);
1024         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1025
1026         node_page = f2fs_get_node_page(sbi, nid);
1027         if (IS_ERR(node_page))
1028                 return false;
1029
1030         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1031                 f2fs_put_page(node_page, 1);
1032                 return false;
1033         }
1034
1035         if (sum->version != dni->version) {
1036                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1037                           __func__);
1038                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1039         }
1040
1041         if (f2fs_check_nid_range(sbi, dni->ino))
1042                 return false;
1043
1044         *nofs = ofs_of_node(node_page);
1045         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1046         f2fs_put_page(node_page, 1);
1047
1048         if (source_blkaddr != blkaddr) {
1049 #ifdef CONFIG_F2FS_CHECK_FS
1050                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1051                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1052
1053                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1054                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1055                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1056                                          blkaddr, source_blkaddr, segno);
1057                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1058                         }
1059                 }
1060 #endif
1061                 return false;
1062         }
1063         return true;
1064 }
1065
1066 static int ra_data_block(struct inode *inode, pgoff_t index)
1067 {
1068         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1069         struct address_space *mapping = inode->i_mapping;
1070         struct dnode_of_data dn;
1071         struct page *page;
1072         struct extent_info ei = {0, 0, 0};
1073         struct f2fs_io_info fio = {
1074                 .sbi = sbi,
1075                 .ino = inode->i_ino,
1076                 .type = DATA,
1077                 .temp = COLD,
1078                 .op = REQ_OP_READ,
1079                 .op_flags = 0,
1080                 .encrypted_page = NULL,
1081                 .in_list = false,
1082                 .retry = false,
1083         };
1084         int err;
1085
1086         page = f2fs_grab_cache_page(mapping, index, true);
1087         if (!page)
1088                 return -ENOMEM;
1089
1090         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1091                 dn.data_blkaddr = ei.blk + index - ei.fofs;
1092                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1093                                                 DATA_GENERIC_ENHANCE_READ))) {
1094                         err = -EFSCORRUPTED;
1095                         goto put_page;
1096                 }
1097                 goto got_it;
1098         }
1099
1100         set_new_dnode(&dn, inode, NULL, NULL, 0);
1101         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1102         if (err)
1103                 goto put_page;
1104         f2fs_put_dnode(&dn);
1105
1106         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1107                 err = -ENOENT;
1108                 goto put_page;
1109         }
1110         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1111                                                 DATA_GENERIC_ENHANCE))) {
1112                 err = -EFSCORRUPTED;
1113                 goto put_page;
1114         }
1115 got_it:
1116         /* read page */
1117         fio.page = page;
1118         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1119
1120         /*
1121          * don't cache encrypted data into meta inode until previous dirty
1122          * data were writebacked to avoid racing between GC and flush.
1123          */
1124         f2fs_wait_on_page_writeback(page, DATA, true, true);
1125
1126         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1127
1128         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1129                                         dn.data_blkaddr,
1130                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1131         if (!fio.encrypted_page) {
1132                 err = -ENOMEM;
1133                 goto put_page;
1134         }
1135
1136         err = f2fs_submit_page_bio(&fio);
1137         if (err)
1138                 goto put_encrypted_page;
1139         f2fs_put_page(fio.encrypted_page, 0);
1140         f2fs_put_page(page, 1);
1141
1142         f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1143         f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1144
1145         return 0;
1146 put_encrypted_page:
1147         f2fs_put_page(fio.encrypted_page, 1);
1148 put_page:
1149         f2fs_put_page(page, 1);
1150         return err;
1151 }
1152
1153 /*
1154  * Move data block via META_MAPPING while keeping locked data page.
1155  * This can be used to move blocks, aka LBAs, directly on disk.
1156  */
1157 static int move_data_block(struct inode *inode, block_t bidx,
1158                                 int gc_type, unsigned int segno, int off)
1159 {
1160         struct f2fs_io_info fio = {
1161                 .sbi = F2FS_I_SB(inode),
1162                 .ino = inode->i_ino,
1163                 .type = DATA,
1164                 .temp = COLD,
1165                 .op = REQ_OP_READ,
1166                 .op_flags = 0,
1167                 .encrypted_page = NULL,
1168                 .in_list = false,
1169                 .retry = false,
1170         };
1171         struct dnode_of_data dn;
1172         struct f2fs_summary sum;
1173         struct node_info ni;
1174         struct page *page, *mpage;
1175         block_t newaddr;
1176         int err = 0;
1177         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1178         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1179                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1180                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1181
1182         /* do not read out */
1183         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1184         if (!page)
1185                 return -ENOMEM;
1186
1187         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1188                 err = -ENOENT;
1189                 goto out;
1190         }
1191
1192         if (f2fs_is_atomic_file(inode)) {
1193                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1194                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1195                 err = -EAGAIN;
1196                 goto out;
1197         }
1198
1199         if (f2fs_is_pinned_file(inode)) {
1200                 f2fs_pin_file_control(inode, true);
1201                 err = -EAGAIN;
1202                 goto out;
1203         }
1204
1205         set_new_dnode(&dn, inode, NULL, NULL, 0);
1206         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1207         if (err)
1208                 goto out;
1209
1210         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1211                 ClearPageUptodate(page);
1212                 err = -ENOENT;
1213                 goto put_out;
1214         }
1215
1216         /*
1217          * don't cache encrypted data into meta inode until previous dirty
1218          * data were writebacked to avoid racing between GC and flush.
1219          */
1220         f2fs_wait_on_page_writeback(page, DATA, true, true);
1221
1222         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1223
1224         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1225         if (err)
1226                 goto put_out;
1227
1228         /* read page */
1229         fio.page = page;
1230         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1231
1232         if (lfs_mode)
1233                 down_write(&fio.sbi->io_order_lock);
1234
1235         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1236                                         fio.old_blkaddr, false);
1237         if (!mpage) {
1238                 err = -ENOMEM;
1239                 goto up_out;
1240         }
1241
1242         fio.encrypted_page = mpage;
1243
1244         /* read source block in mpage */
1245         if (!PageUptodate(mpage)) {
1246                 err = f2fs_submit_page_bio(&fio);
1247                 if (err) {
1248                         f2fs_put_page(mpage, 1);
1249                         goto up_out;
1250                 }
1251
1252                 f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1253                 f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1254
1255                 lock_page(mpage);
1256                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1257                                                 !PageUptodate(mpage))) {
1258                         err = -EIO;
1259                         f2fs_put_page(mpage, 1);
1260                         goto up_out;
1261                 }
1262         }
1263
1264         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1265
1266         /* allocate block address */
1267         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1268                                 &sum, type, NULL);
1269
1270         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1271                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1272         if (!fio.encrypted_page) {
1273                 err = -ENOMEM;
1274                 f2fs_put_page(mpage, 1);
1275                 goto recover_block;
1276         }
1277
1278         /* write target block */
1279         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1280         memcpy(page_address(fio.encrypted_page),
1281                                 page_address(mpage), PAGE_SIZE);
1282         f2fs_put_page(mpage, 1);
1283         invalidate_mapping_pages(META_MAPPING(fio.sbi),
1284                                 fio.old_blkaddr, fio.old_blkaddr);
1285         f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1286
1287         set_page_dirty(fio.encrypted_page);
1288         if (clear_page_dirty_for_io(fio.encrypted_page))
1289                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1290
1291         set_page_writeback(fio.encrypted_page);
1292         ClearPageError(page);
1293
1294         fio.op = REQ_OP_WRITE;
1295         fio.op_flags = REQ_SYNC;
1296         fio.new_blkaddr = newaddr;
1297         f2fs_submit_page_write(&fio);
1298         if (fio.retry) {
1299                 err = -EAGAIN;
1300                 if (PageWriteback(fio.encrypted_page))
1301                         end_page_writeback(fio.encrypted_page);
1302                 goto put_page_out;
1303         }
1304
1305         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1306
1307         f2fs_update_data_blkaddr(&dn, newaddr);
1308         set_inode_flag(inode, FI_APPEND_WRITE);
1309         if (page->index == 0)
1310                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1311 put_page_out:
1312         f2fs_put_page(fio.encrypted_page, 1);
1313 recover_block:
1314         if (err)
1315                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1316                                                         true, true, true);
1317 up_out:
1318         if (lfs_mode)
1319                 up_write(&fio.sbi->io_order_lock);
1320 put_out:
1321         f2fs_put_dnode(&dn);
1322 out:
1323         f2fs_put_page(page, 1);
1324         return err;
1325 }
1326
1327 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1328                                                         unsigned int segno, int off)
1329 {
1330         struct page *page;
1331         int err = 0;
1332
1333         page = f2fs_get_lock_data_page(inode, bidx, true);
1334         if (IS_ERR(page))
1335                 return PTR_ERR(page);
1336
1337         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1338                 err = -ENOENT;
1339                 goto out;
1340         }
1341
1342         if (f2fs_is_atomic_file(inode)) {
1343                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1344                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1345                 err = -EAGAIN;
1346                 goto out;
1347         }
1348         if (f2fs_is_pinned_file(inode)) {
1349                 if (gc_type == FG_GC)
1350                         f2fs_pin_file_control(inode, true);
1351                 err = -EAGAIN;
1352                 goto out;
1353         }
1354
1355         if (gc_type == BG_GC) {
1356                 if (PageWriteback(page)) {
1357                         err = -EAGAIN;
1358                         goto out;
1359                 }
1360                 set_page_dirty(page);
1361                 set_page_private_gcing(page);
1362         } else {
1363                 struct f2fs_io_info fio = {
1364                         .sbi = F2FS_I_SB(inode),
1365                         .ino = inode->i_ino,
1366                         .type = DATA,
1367                         .temp = COLD,
1368                         .op = REQ_OP_WRITE,
1369                         .op_flags = REQ_SYNC,
1370                         .old_blkaddr = NULL_ADDR,
1371                         .page = page,
1372                         .encrypted_page = NULL,
1373                         .need_lock = LOCK_REQ,
1374                         .io_type = FS_GC_DATA_IO,
1375                 };
1376                 bool is_dirty = PageDirty(page);
1377
1378 retry:
1379                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1380
1381                 set_page_dirty(page);
1382                 if (clear_page_dirty_for_io(page)) {
1383                         inode_dec_dirty_pages(inode);
1384                         f2fs_remove_dirty_inode(inode);
1385                 }
1386
1387                 set_page_private_gcing(page);
1388
1389                 err = f2fs_do_write_data_page(&fio);
1390                 if (err) {
1391                         clear_page_private_gcing(page);
1392                         if (err == -ENOMEM) {
1393                                 memalloc_retry_wait(GFP_NOFS);
1394                                 goto retry;
1395                         }
1396                         if (is_dirty)
1397                                 set_page_dirty(page);
1398                 }
1399         }
1400 out:
1401         f2fs_put_page(page, 1);
1402         return err;
1403 }
1404
1405 /*
1406  * This function tries to get parent node of victim data block, and identifies
1407  * data block validity. If the block is valid, copy that with cold status and
1408  * modify parent node.
1409  * If the parent node is not valid or the data block address is different,
1410  * the victim data block is ignored.
1411  */
1412 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1413                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1414                 bool force_migrate)
1415 {
1416         struct super_block *sb = sbi->sb;
1417         struct f2fs_summary *entry;
1418         block_t start_addr;
1419         int off;
1420         int phase = 0;
1421         int submitted = 0;
1422         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1423
1424         start_addr = START_BLOCK(sbi, segno);
1425
1426 next_step:
1427         entry = sum;
1428
1429         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1430                 struct page *data_page;
1431                 struct inode *inode;
1432                 struct node_info dni; /* dnode info for the data */
1433                 unsigned int ofs_in_node, nofs;
1434                 block_t start_bidx;
1435                 nid_t nid = le32_to_cpu(entry->nid);
1436
1437                 /*
1438                  * stop BG_GC if there is not enough free sections.
1439                  * Or, stop GC if the segment becomes fully valid caused by
1440                  * race condition along with SSR block allocation.
1441                  */
1442                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1443                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1444                                                         BLKS_PER_SEC(sbi)))
1445                         return submitted;
1446
1447                 if (check_valid_map(sbi, segno, off) == 0)
1448                         continue;
1449
1450                 if (phase == 0) {
1451                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1452                                                         META_NAT, true);
1453                         continue;
1454                 }
1455
1456                 if (phase == 1) {
1457                         f2fs_ra_node_page(sbi, nid);
1458                         continue;
1459                 }
1460
1461                 /* Get an inode by ino with checking validity */
1462                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1463                         continue;
1464
1465                 if (phase == 2) {
1466                         f2fs_ra_node_page(sbi, dni.ino);
1467                         continue;
1468                 }
1469
1470                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1471
1472                 if (phase == 3) {
1473                         inode = f2fs_iget(sb, dni.ino);
1474                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1475                                         special_file(inode->i_mode))
1476                                 continue;
1477
1478                         if (!down_write_trylock(
1479                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1480                                 iput(inode);
1481                                 sbi->skipped_gc_rwsem++;
1482                                 continue;
1483                         }
1484
1485                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1486                                                                 ofs_in_node;
1487
1488                         if (f2fs_post_read_required(inode)) {
1489                                 int err = ra_data_block(inode, start_bidx);
1490
1491                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1492                                 if (err) {
1493                                         iput(inode);
1494                                         continue;
1495                                 }
1496                                 add_gc_inode(gc_list, inode);
1497                                 continue;
1498                         }
1499
1500                         data_page = f2fs_get_read_data_page(inode,
1501                                                 start_bidx, REQ_RAHEAD, true);
1502                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1503                         if (IS_ERR(data_page)) {
1504                                 iput(inode);
1505                                 continue;
1506                         }
1507
1508                         f2fs_put_page(data_page, 0);
1509                         add_gc_inode(gc_list, inode);
1510                         continue;
1511                 }
1512
1513                 /* phase 4 */
1514                 inode = find_gc_inode(gc_list, dni.ino);
1515                 if (inode) {
1516                         struct f2fs_inode_info *fi = F2FS_I(inode);
1517                         bool locked = false;
1518                         int err;
1519
1520                         if (S_ISREG(inode->i_mode)) {
1521                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ])) {
1522                                         sbi->skipped_gc_rwsem++;
1523                                         continue;
1524                                 }
1525                                 if (!down_write_trylock(
1526                                                 &fi->i_gc_rwsem[WRITE])) {
1527                                         sbi->skipped_gc_rwsem++;
1528                                         up_write(&fi->i_gc_rwsem[READ]);
1529                                         continue;
1530                                 }
1531                                 locked = true;
1532
1533                                 /* wait for all inflight aio data */
1534                                 inode_dio_wait(inode);
1535                         }
1536
1537                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1538                                                                 + ofs_in_node;
1539                         if (f2fs_post_read_required(inode))
1540                                 err = move_data_block(inode, start_bidx,
1541                                                         gc_type, segno, off);
1542                         else
1543                                 err = move_data_page(inode, start_bidx, gc_type,
1544                                                                 segno, off);
1545
1546                         if (!err && (gc_type == FG_GC ||
1547                                         f2fs_post_read_required(inode)))
1548                                 submitted++;
1549
1550                         if (locked) {
1551                                 up_write(&fi->i_gc_rwsem[WRITE]);
1552                                 up_write(&fi->i_gc_rwsem[READ]);
1553                         }
1554
1555                         stat_inc_data_blk_count(sbi, 1, gc_type);
1556                 }
1557         }
1558
1559         if (++phase < 5)
1560                 goto next_step;
1561
1562         return submitted;
1563 }
1564
1565 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1566                         int gc_type)
1567 {
1568         struct sit_info *sit_i = SIT_I(sbi);
1569         int ret;
1570
1571         down_write(&sit_i->sentry_lock);
1572         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1573                                               NO_CHECK_TYPE, LFS, 0);
1574         up_write(&sit_i->sentry_lock);
1575         return ret;
1576 }
1577
1578 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1579                                 unsigned int start_segno,
1580                                 struct gc_inode_list *gc_list, int gc_type,
1581                                 bool force_migrate)
1582 {
1583         struct page *sum_page;
1584         struct f2fs_summary_block *sum;
1585         struct blk_plug plug;
1586         unsigned int segno = start_segno;
1587         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1588         int seg_freed = 0, migrated = 0;
1589         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1590                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1591         int submitted = 0;
1592
1593         if (__is_large_section(sbi))
1594                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1595
1596         /*
1597          * zone-capacity can be less than zone-size in zoned devices,
1598          * resulting in less than expected usable segments in the zone,
1599          * calculate the end segno in the zone which can be garbage collected
1600          */
1601         if (f2fs_sb_has_blkzoned(sbi))
1602                 end_segno -= sbi->segs_per_sec -
1603                                         f2fs_usable_segs_in_sec(sbi, segno);
1604
1605         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1606
1607         /* readahead multi ssa blocks those have contiguous address */
1608         if (__is_large_section(sbi))
1609                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1610                                         end_segno - segno, META_SSA, true);
1611
1612         /* reference all summary page */
1613         while (segno < end_segno) {
1614                 sum_page = f2fs_get_sum_page(sbi, segno++);
1615                 if (IS_ERR(sum_page)) {
1616                         int err = PTR_ERR(sum_page);
1617
1618                         end_segno = segno - 1;
1619                         for (segno = start_segno; segno < end_segno; segno++) {
1620                                 sum_page = find_get_page(META_MAPPING(sbi),
1621                                                 GET_SUM_BLOCK(sbi, segno));
1622                                 f2fs_put_page(sum_page, 0);
1623                                 f2fs_put_page(sum_page, 0);
1624                         }
1625                         return err;
1626                 }
1627                 unlock_page(sum_page);
1628         }
1629
1630         blk_start_plug(&plug);
1631
1632         for (segno = start_segno; segno < end_segno; segno++) {
1633
1634                 /* find segment summary of victim */
1635                 sum_page = find_get_page(META_MAPPING(sbi),
1636                                         GET_SUM_BLOCK(sbi, segno));
1637                 f2fs_put_page(sum_page, 0);
1638
1639                 if (get_valid_blocks(sbi, segno, false) == 0)
1640                         goto freed;
1641                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1642                                 migrated >= sbi->migration_granularity)
1643                         goto skip;
1644                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1645                         goto skip;
1646
1647                 sum = page_address(sum_page);
1648                 if (type != GET_SUM_TYPE((&sum->footer))) {
1649                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1650                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1651                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1652                         f2fs_stop_checkpoint(sbi, false);
1653                         goto skip;
1654                 }
1655
1656                 /*
1657                  * this is to avoid deadlock:
1658                  * - lock_page(sum_page)         - f2fs_replace_block
1659                  *  - check_valid_map()            - down_write(sentry_lock)
1660                  *   - down_read(sentry_lock)     - change_curseg()
1661                  *                                  - lock_page(sum_page)
1662                  */
1663                 if (type == SUM_TYPE_NODE)
1664                         submitted += gc_node_segment(sbi, sum->entries, segno,
1665                                                                 gc_type);
1666                 else
1667                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1668                                                         segno, gc_type,
1669                                                         force_migrate);
1670
1671                 stat_inc_seg_count(sbi, type, gc_type);
1672                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1673                 migrated++;
1674
1675 freed:
1676                 if (gc_type == FG_GC &&
1677                                 get_valid_blocks(sbi, segno, false) == 0)
1678                         seg_freed++;
1679
1680                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1681                         sbi->next_victim_seg[gc_type] = segno + 1;
1682 skip:
1683                 f2fs_put_page(sum_page, 0);
1684         }
1685
1686         if (submitted)
1687                 f2fs_submit_merged_write(sbi,
1688                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1689
1690         blk_finish_plug(&plug);
1691
1692         stat_inc_call_count(sbi->stat_info);
1693
1694         return seg_freed;
1695 }
1696
1697 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1698                         bool background, bool force, unsigned int segno)
1699 {
1700         int gc_type = sync ? FG_GC : BG_GC;
1701         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1702         int ret = 0;
1703         struct cp_control cpc;
1704         unsigned int init_segno = segno;
1705         struct gc_inode_list gc_list = {
1706                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1707                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1708         };
1709         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1710         unsigned long long first_skipped;
1711         unsigned int skipped_round = 0, round = 0;
1712
1713         trace_f2fs_gc_begin(sbi->sb, sync, background,
1714                                 get_pages(sbi, F2FS_DIRTY_NODES),
1715                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1716                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1717                                 free_sections(sbi),
1718                                 free_segments(sbi),
1719                                 reserved_segments(sbi),
1720                                 prefree_segments(sbi));
1721
1722         cpc.reason = __get_cp_reason(sbi);
1723         sbi->skipped_gc_rwsem = 0;
1724         first_skipped = last_skipped;
1725 gc_more:
1726         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1727                 ret = -EINVAL;
1728                 goto stop;
1729         }
1730         if (unlikely(f2fs_cp_error(sbi))) {
1731                 ret = -EIO;
1732                 goto stop;
1733         }
1734
1735         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1736                 /*
1737                  * For example, if there are many prefree_segments below given
1738                  * threshold, we can make them free by checkpoint. Then, we
1739                  * secure free segments which doesn't need fggc any more.
1740                  */
1741                 if (prefree_segments(sbi) &&
1742                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1743                         ret = f2fs_write_checkpoint(sbi, &cpc);
1744                         if (ret)
1745                                 goto stop;
1746                 }
1747                 if (has_not_enough_free_secs(sbi, 0, 0))
1748                         gc_type = FG_GC;
1749         }
1750
1751         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1752         if (gc_type == BG_GC && !background) {
1753                 ret = -EINVAL;
1754                 goto stop;
1755         }
1756         ret = __get_victim(sbi, &segno, gc_type);
1757         if (ret)
1758                 goto stop;
1759
1760         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1761         if (gc_type == FG_GC &&
1762                 seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1763                 sec_freed++;
1764         total_freed += seg_freed;
1765
1766         if (gc_type == FG_GC) {
1767                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1768                                                 sbi->skipped_gc_rwsem)
1769                         skipped_round++;
1770                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1771                 round++;
1772         }
1773
1774         if (gc_type == FG_GC)
1775                 sbi->cur_victim_sec = NULL_SEGNO;
1776
1777         if (sync)
1778                 goto stop;
1779
1780         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1781                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1782                                         skipped_round * 2 < round) {
1783                         segno = NULL_SEGNO;
1784                         goto gc_more;
1785                 }
1786
1787                 if (first_skipped < last_skipped &&
1788                                 (last_skipped - first_skipped) >
1789                                                 sbi->skipped_gc_rwsem) {
1790                         f2fs_drop_inmem_pages_all(sbi, true);
1791                         segno = NULL_SEGNO;
1792                         goto gc_more;
1793                 }
1794                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1795                         ret = f2fs_write_checkpoint(sbi, &cpc);
1796         }
1797 stop:
1798         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1799         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1800
1801         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1802                                 get_pages(sbi, F2FS_DIRTY_NODES),
1803                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1804                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1805                                 free_sections(sbi),
1806                                 free_segments(sbi),
1807                                 reserved_segments(sbi),
1808                                 prefree_segments(sbi));
1809
1810         up_write(&sbi->gc_lock);
1811
1812         put_gc_inode(&gc_list);
1813
1814         if (sync && !ret)
1815                 ret = sec_freed ? 0 : -EAGAIN;
1816         return ret;
1817 }
1818
1819 int __init f2fs_create_garbage_collection_cache(void)
1820 {
1821         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1822                                         sizeof(struct victim_entry));
1823         if (!victim_entry_slab)
1824                 return -ENOMEM;
1825         return 0;
1826 }
1827
1828 void f2fs_destroy_garbage_collection_cache(void)
1829 {
1830         kmem_cache_destroy(victim_entry_slab);
1831 }
1832
1833 static void init_atgc_management(struct f2fs_sb_info *sbi)
1834 {
1835         struct atgc_management *am = &sbi->am;
1836
1837         if (test_opt(sbi, ATGC) &&
1838                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1839                 am->atgc_enabled = true;
1840
1841         am->root = RB_ROOT_CACHED;
1842         INIT_LIST_HEAD(&am->victim_list);
1843         am->victim_count = 0;
1844
1845         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1846         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1847         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1848         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1849 }
1850
1851 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1852 {
1853         DIRTY_I(sbi)->v_ops = &default_v_ops;
1854
1855         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1856
1857         /* give warm/cold data area from slower device */
1858         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1859                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1860                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1861
1862         init_atgc_management(sbi);
1863 }
1864
1865 static int free_segment_range(struct f2fs_sb_info *sbi,
1866                                 unsigned int secs, bool gc_only)
1867 {
1868         unsigned int segno, next_inuse, start, end;
1869         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1870         int gc_mode, gc_type;
1871         int err = 0;
1872         int type;
1873
1874         /* Force block allocation for GC */
1875         MAIN_SECS(sbi) -= secs;
1876         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1877         end = MAIN_SEGS(sbi) - 1;
1878
1879         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1880         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1881                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1882                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1883
1884         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1885                 if (sbi->next_victim_seg[gc_type] >= start)
1886                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1887         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1888
1889         /* Move out cursegs from the target range */
1890         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1891                 f2fs_allocate_segment_for_resize(sbi, type, start, end);
1892
1893         /* do GC to move out valid blocks in the range */
1894         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1895                 struct gc_inode_list gc_list = {
1896                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1897                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1898                 };
1899
1900                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1901                 put_gc_inode(&gc_list);
1902
1903                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1904                         err = -EAGAIN;
1905                         goto out;
1906                 }
1907                 if (fatal_signal_pending(current)) {
1908                         err = -ERESTARTSYS;
1909                         goto out;
1910                 }
1911         }
1912         if (gc_only)
1913                 goto out;
1914
1915         err = f2fs_write_checkpoint(sbi, &cpc);
1916         if (err)
1917                 goto out;
1918
1919         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1920         if (next_inuse <= end) {
1921                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1922                          next_inuse);
1923                 f2fs_bug_on(sbi, 1);
1924         }
1925 out:
1926         MAIN_SECS(sbi) += secs;
1927         return err;
1928 }
1929
1930 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1931 {
1932         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1933         int section_count;
1934         int segment_count;
1935         int segment_count_main;
1936         long long block_count;
1937         int segs = secs * sbi->segs_per_sec;
1938
1939         down_write(&sbi->sb_lock);
1940
1941         section_count = le32_to_cpu(raw_sb->section_count);
1942         segment_count = le32_to_cpu(raw_sb->segment_count);
1943         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1944         block_count = le64_to_cpu(raw_sb->block_count);
1945
1946         raw_sb->section_count = cpu_to_le32(section_count + secs);
1947         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1948         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1949         raw_sb->block_count = cpu_to_le64(block_count +
1950                                         (long long)segs * sbi->blocks_per_seg);
1951         if (f2fs_is_multi_device(sbi)) {
1952                 int last_dev = sbi->s_ndevs - 1;
1953                 int dev_segs =
1954                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1955
1956                 raw_sb->devs[last_dev].total_segments =
1957                                                 cpu_to_le32(dev_segs + segs);
1958         }
1959
1960         up_write(&sbi->sb_lock);
1961 }
1962
1963 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1964 {
1965         int segs = secs * sbi->segs_per_sec;
1966         long long blks = (long long)segs * sbi->blocks_per_seg;
1967         long long user_block_count =
1968                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1969
1970         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1971         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1972         MAIN_SECS(sbi) += secs;
1973         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1974         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1975         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1976
1977         if (f2fs_is_multi_device(sbi)) {
1978                 int last_dev = sbi->s_ndevs - 1;
1979
1980                 FDEV(last_dev).total_segments =
1981                                 (int)FDEV(last_dev).total_segments + segs;
1982                 FDEV(last_dev).end_blk =
1983                                 (long long)FDEV(last_dev).end_blk + blks;
1984 #ifdef CONFIG_BLK_DEV_ZONED
1985                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1986                                         (int)(blks >> sbi->log_blocks_per_blkz);
1987 #endif
1988         }
1989 }
1990
1991 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1992 {
1993         __u64 old_block_count, shrunk_blocks;
1994         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1995         unsigned int secs;
1996         int err = 0;
1997         __u32 rem;
1998
1999         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2000         if (block_count > old_block_count)
2001                 return -EINVAL;
2002
2003         if (f2fs_is_multi_device(sbi)) {
2004                 int last_dev = sbi->s_ndevs - 1;
2005                 __u64 last_segs = FDEV(last_dev).total_segments;
2006
2007                 if (block_count + last_segs * sbi->blocks_per_seg <=
2008                                                                 old_block_count)
2009                         return -EINVAL;
2010         }
2011
2012         /* new fs size should align to section size */
2013         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2014         if (rem)
2015                 return -EINVAL;
2016
2017         if (block_count == old_block_count)
2018                 return 0;
2019
2020         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2021                 f2fs_err(sbi, "Should run fsck to repair first.");
2022                 return -EFSCORRUPTED;
2023         }
2024
2025         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2026                 f2fs_err(sbi, "Checkpoint should be enabled.");
2027                 return -EINVAL;
2028         }
2029
2030         shrunk_blocks = old_block_count - block_count;
2031         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2032
2033         /* stop other GC */
2034         if (!down_write_trylock(&sbi->gc_lock))
2035                 return -EAGAIN;
2036
2037         /* stop CP to protect MAIN_SEC in free_segment_range */
2038         f2fs_lock_op(sbi);
2039
2040         spin_lock(&sbi->stat_lock);
2041         if (shrunk_blocks + valid_user_blocks(sbi) +
2042                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2043                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2044                 err = -ENOSPC;
2045         spin_unlock(&sbi->stat_lock);
2046
2047         if (err)
2048                 goto out_unlock;
2049
2050         err = free_segment_range(sbi, secs, true);
2051
2052 out_unlock:
2053         f2fs_unlock_op(sbi);
2054         up_write(&sbi->gc_lock);
2055         if (err)
2056                 return err;
2057
2058         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2059
2060         freeze_super(sbi->sb);
2061         down_write(&sbi->gc_lock);
2062         down_write(&sbi->cp_global_sem);
2063
2064         spin_lock(&sbi->stat_lock);
2065         if (shrunk_blocks + valid_user_blocks(sbi) +
2066                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2067                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2068                 err = -ENOSPC;
2069         else
2070                 sbi->user_block_count -= shrunk_blocks;
2071         spin_unlock(&sbi->stat_lock);
2072         if (err)
2073                 goto out_err;
2074
2075         err = free_segment_range(sbi, secs, false);
2076         if (err)
2077                 goto recover_out;
2078
2079         update_sb_metadata(sbi, -secs);
2080
2081         err = f2fs_commit_super(sbi, false);
2082         if (err) {
2083                 update_sb_metadata(sbi, secs);
2084                 goto recover_out;
2085         }
2086
2087         update_fs_metadata(sbi, -secs);
2088         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2089         set_sbi_flag(sbi, SBI_IS_DIRTY);
2090
2091         err = f2fs_write_checkpoint(sbi, &cpc);
2092         if (err) {
2093                 update_fs_metadata(sbi, secs);
2094                 update_sb_metadata(sbi, secs);
2095                 f2fs_commit_super(sbi, false);
2096         }
2097 recover_out:
2098         if (err) {
2099                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2100                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2101
2102                 spin_lock(&sbi->stat_lock);
2103                 sbi->user_block_count += shrunk_blocks;
2104                 spin_unlock(&sbi->stat_lock);
2105         }
2106 out_err:
2107         up_write(&sbi->cp_global_sem);
2108         up_write(&sbi->gc_lock);
2109         thaw_super(sbi->sb);
2110         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2111         return err;
2112 }