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
 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                 /* if return value is not zero, no victim was selected */
 145                 if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
 146                         wait_ms = gc_th->no_gc_sleep_time;
 147
 148                 if (foreground)
 149                         wake_up_all(&gc_th->fggc_wq);
 150
 151                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 152                                 prefree_segments(sbi), free_segments(sbi));
 153
 154                 /* balancing f2fs's metadata periodically */
 155                 f2fs_balance_fs_bg(sbi, true);
 156 next:
 157                 sb_end_write(sbi->sb);
 158
 159         } while (!kthread_should_stop());
 160         return 0;
 161 }
 162
 163 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 164 {
 165         struct f2fs_gc_kthread *gc_th;
 166         dev_t dev = sbi->sb->s_bdev->bd_dev;
 167         int err = 0;
 168
 169         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 170         if (!gc_th) {
 171                 err = -ENOMEM;
 172                 goto out;
 173         }
 174
 175         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 176         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 177         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 178         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 179
 180         gc_th->gc_wake = 0;
 181
 182         sbi->gc_thread = gc_th;
 183         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 184         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 185         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 186                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 187         if (IS_ERR(gc_th->f2fs_gc_task)) {
 188                 err = PTR_ERR(gc_th->f2fs_gc_task);
 189                 kfree(gc_th);
 190                 sbi->gc_thread = NULL;
 191         }
 192 out:
 193         return err;
 194 }
 195
 196 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 197 {
 198         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 199
 200         if (!gc_th)
 201                 return;
 202         kthread_stop(gc_th->f2fs_gc_task);
 203         wake_up_all(&gc_th->fggc_wq);
 204         kfree(gc_th);
 205         sbi->gc_thread = NULL;
 206 }
 207
 208 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 209 {
 210         int gc_mode;
 211
 212         if (gc_type == BG_GC) {
 213                 if (sbi->am.atgc_enabled)
 214                         gc_mode = GC_AT;
 215                 else
 216                         gc_mode = GC_CB;
 217         } else {
 218                 gc_mode = GC_GREEDY;
 219         }
 220
 221         switch (sbi->gc_mode) {
 222         case GC_IDLE_CB:
 223                 gc_mode = GC_CB;
 224                 break;
 225         case GC_IDLE_GREEDY:
 226         case GC_URGENT_HIGH:
 227                 gc_mode = GC_GREEDY;
 228                 break;
 229         case GC_IDLE_AT:
 230                 gc_mode = GC_AT;
 231                 break;
 232         }
 233
 234         return gc_mode;
 235 }
 236
 237 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 238                         int type, struct victim_sel_policy *p)
 239 {
 240         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 241
 242         if (p->alloc_mode == SSR) {
 243                 p->gc_mode = GC_GREEDY;
 244                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 245                 p->max_search = dirty_i->nr_dirty[type];
 246                 p->ofs_unit = 1;
 247         } else if (p->alloc_mode == AT_SSR) {
 248                 p->gc_mode = GC_GREEDY;
 249                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 250                 p->max_search = dirty_i->nr_dirty[type];
 251                 p->ofs_unit = 1;
 252         } else {
 253                 p->gc_mode = select_gc_type(sbi, gc_type);
 254                 p->ofs_unit = sbi->segs_per_sec;
 255                 if (__is_large_section(sbi)) {
 256                         p->dirty_bitmap = dirty_i->dirty_secmap;
 257                         p->max_search = count_bits(p->dirty_bitmap,
 258                                                 0, MAIN_SECS(sbi));
 259                 } else {
 260                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 261                         p->max_search = dirty_i->nr_dirty[DIRTY];
 262                 }
 263         }
 264
 265         /*
 266          * adjust candidates range, should select all dirty segments for
 267          * foreground GC and urgent GC cases.
 268          */
 269         if (gc_type != FG_GC &&
 270                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 271                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 272                         p->max_search > sbi->max_victim_search)
 273                 p->max_search = sbi->max_victim_search;
 274
 275         /* let's select beginning hot/small space first in no_heap mode*/
 276         if (f2fs_need_rand_seg(sbi))
 277                 p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
 278         else if (test_opt(sbi, NOHEAP) &&
 279                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 280                 p->offset = 0;
 281         else
 282                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 283 }
 284
 285 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 286                                 struct victim_sel_policy *p)
 287 {
 288         /* SSR allocates in a segment unit */
 289         if (p->alloc_mode == SSR)
 290                 return sbi->blocks_per_seg;
 291         else if (p->alloc_mode == AT_SSR)
 292                 return UINT_MAX;
 293
 294         /* LFS */
 295         if (p->gc_mode == GC_GREEDY)
 296                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 297         else if (p->gc_mode == GC_CB)
 298                 return UINT_MAX;
 299         else if (p->gc_mode == GC_AT)
 300                 return UINT_MAX;
 301         else /* No other gc_mode */
 302                 return 0;
 303 }
 304
 305 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 306 {
 307         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 308         unsigned int secno;
 309
 310         /*
 311          * If the gc_type is FG_GC, we can select victim segments
 312          * selected by background GC before.
 313          * Those segments guarantee they have small valid blocks.
 314          */
 315         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 316                 if (sec_usage_check(sbi, secno))
 317                         continue;
 318                 clear_bit(secno, dirty_i->victim_secmap);
 319                 return GET_SEG_FROM_SEC(sbi, secno);
 320         }
 321         return NULL_SEGNO;
 322 }
 323
 324 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 325 {
 326         struct sit_info *sit_i = SIT_I(sbi);
 327         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 328         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 329         unsigned long long mtime = 0;
 330         unsigned int vblocks;
 331         unsigned char age = 0;
 332         unsigned char u;
 333         unsigned int i;
 334         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 335
 336         for (i = 0; i < usable_segs_per_sec; i++)
 337                 mtime += get_seg_entry(sbi, start + i)->mtime;
 338         vblocks = get_valid_blocks(sbi, segno, true);
 339
 340         mtime = div_u64(mtime, usable_segs_per_sec);
 341         vblocks = div_u64(vblocks, usable_segs_per_sec);
 342
 343         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 344
 345         /* Handle if the system time has changed by the user */
 346         if (mtime < sit_i->min_mtime)
 347                 sit_i->min_mtime = mtime;
 348         if (mtime > sit_i->max_mtime)
 349                 sit_i->max_mtime = mtime;
 350         if (sit_i->max_mtime != sit_i->min_mtime)
 351                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 352                                 sit_i->max_mtime - sit_i->min_mtime);
 353
 354         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 355 }
 356
 357 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 358                         unsigned int segno, struct victim_sel_policy *p)
 359 {
 360         if (p->alloc_mode == SSR)
 361                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 362
 363         /* alloc_mode == LFS */
 364         if (p->gc_mode == GC_GREEDY)
 365                 return get_valid_blocks(sbi, segno, true);
 366         else if (p->gc_mode == GC_CB)
 367                 return get_cb_cost(sbi, segno);
 368
 369         f2fs_bug_on(sbi, 1);
 370         return 0;
 371 }
 372
 373 static unsigned int count_bits(const unsigned long *addr,
 374                                 unsigned int offset, unsigned int len)
 375 {
 376         unsigned int end = offset + len, sum = 0;
 377
 378         while (offset < end) {
 379                 if (test_bit(offset++, addr))
 380                         ++sum;
 381         }
 382         return sum;
 383 }
 384
 385 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 386                                 unsigned long long mtime, unsigned int segno,
 387                                 struct rb_node *parent, struct rb_node **p,
 388                                 bool left_most)
 389 {
 390         struct atgc_management *am = &sbi->am;
 391         struct victim_entry *ve;
 392
 393         ve =  f2fs_kmem_cache_alloc(victim_entry_slab,
 394                                 GFP_NOFS, true, NULL);
 395
 396         ve->mtime = mtime;
 397         ve->segno = segno;
 398
 399         rb_link_node(&ve->rb_node, parent, p);
 400         rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 401
 402         list_add_tail(&ve->list, &am->victim_list);
 403
 404         am->victim_count++;
 405
 406         return ve;
 407 }
 408
 409 static void insert_victim_entry(struct f2fs_sb_info *sbi,
 410                                 unsigned long long mtime, unsigned int segno)
 411 {
 412         struct atgc_management *am = &sbi->am;
 413         struct rb_node **p;
 414         struct rb_node *parent = NULL;
 415         bool left_most = true;
 416
 417         p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 418         attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 419 }
 420
 421 static void add_victim_entry(struct f2fs_sb_info *sbi,
 422                                 struct victim_sel_policy *p, unsigned int segno)
 423 {
 424         struct sit_info *sit_i = SIT_I(sbi);
 425         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 426         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 427         unsigned long long mtime = 0;
 428         unsigned int i;
 429
 430         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 431                 if (p->gc_mode == GC_AT &&
 432                         get_valid_blocks(sbi, segno, true) == 0)
 433                         return;
 434         }
 435
 436         for (i = 0; i < sbi->segs_per_sec; i++)
 437                 mtime += get_seg_entry(sbi, start + i)->mtime;
 438         mtime = div_u64(mtime, sbi->segs_per_sec);
 439
 440         /* Handle if the system time has changed by the user */
 441         if (mtime < sit_i->min_mtime)
 442                 sit_i->min_mtime = mtime;
 443         if (mtime > sit_i->max_mtime)
 444                 sit_i->max_mtime = mtime;
 445         if (mtime < sit_i->dirty_min_mtime)
 446                 sit_i->dirty_min_mtime = mtime;
 447         if (mtime > sit_i->dirty_max_mtime)
 448                 sit_i->dirty_max_mtime = mtime;
 449
 450         /* don't choose young section as candidate */
 451         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 452                 return;
 453
 454         insert_victim_entry(sbi, mtime, segno);
 455 }
 456
 457 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 458                                                 struct victim_sel_policy *p)
 459 {
 460         struct atgc_management *am = &sbi->am;
 461         struct rb_node *parent = NULL;
 462         bool left_most;
 463
 464         f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 465
 466         return parent;
 467 }
 468
 469 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 470                                                 struct victim_sel_policy *p)
 471 {
 472         struct sit_info *sit_i = SIT_I(sbi);
 473         struct atgc_management *am = &sbi->am;
 474         struct rb_root_cached *root = &am->root;
 475         struct rb_node *node;
 476         struct rb_entry *re;
 477         struct victim_entry *ve;
 478         unsigned long long total_time;
 479         unsigned long long age, u, accu;
 480         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 481         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 482         unsigned int sec_blocks = BLKS_PER_SEC(sbi);
 483         unsigned int vblocks;
 484         unsigned int dirty_threshold = max(am->max_candidate_count,
 485                                         am->candidate_ratio *
 486                                         am->victim_count / 100);
 487         unsigned int age_weight = am->age_weight;
 488         unsigned int cost;
 489         unsigned int iter = 0;
 490
 491         if (max_mtime < min_mtime)
 492                 return;
 493
 494         max_mtime += 1;
 495         total_time = max_mtime - min_mtime;
 496
 497         accu = div64_u64(ULLONG_MAX, total_time);
 498         accu = min_t(unsigned long long, div_u64(accu, 100),
 499                                         DEFAULT_ACCURACY_CLASS);
 500
 501         node = rb_first_cached(root);
 502 next:
 503         re = rb_entry_safe(node, struct rb_entry, rb_node);
 504         if (!re)
 505                 return;
 506
 507         ve = (struct victim_entry *)re;
 508
 509         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 510                 goto skip;
 511
 512         /* age = 10000 * x% * 60 */
 513         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 514                                                                 age_weight;
 515
 516         vblocks = get_valid_blocks(sbi, ve->segno, true);
 517         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 518
 519         /* u = 10000 * x% * 40 */
 520         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 521                                                         (100 - age_weight);
 522
 523         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 524
 525         cost = UINT_MAX - (age + u);
 526         iter++;
 527
 528         if (cost < p->min_cost ||
 529                         (cost == p->min_cost && age > p->oldest_age)) {
 530                 p->min_cost = cost;
 531                 p->oldest_age = age;
 532                 p->min_segno = ve->segno;
 533         }
 534 skip:
 535         if (iter < dirty_threshold) {
 536                 node = rb_next(node);
 537                 goto next;
 538         }
 539 }
 540
 541 /*
 542  * select candidates around source section in range of
 543  * [target - dirty_threshold, target + dirty_threshold]
 544  */
 545 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 546                                                 struct victim_sel_policy *p)
 547 {
 548         struct sit_info *sit_i = SIT_I(sbi);
 549         struct atgc_management *am = &sbi->am;
 550         struct rb_node *node;
 551         struct rb_entry *re;
 552         struct victim_entry *ve;
 553         unsigned long long age;
 554         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 555         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 556         unsigned int seg_blocks = sbi->blocks_per_seg;
 557         unsigned int vblocks;
 558         unsigned int dirty_threshold = max(am->max_candidate_count,
 559                                         am->candidate_ratio *
 560                                         am->victim_count / 100);
 561         unsigned int cost;
 562         unsigned int iter = 0;
 563         int stage = 0;
 564
 565         if (max_mtime < min_mtime)
 566                 return;
 567         max_mtime += 1;
 568 next_stage:
 569         node = lookup_central_victim(sbi, p);
 570 next_node:
 571         re = rb_entry_safe(node, struct rb_entry, rb_node);
 572         if (!re) {
 573                 if (stage == 0)
 574                         goto skip_stage;
 575                 return;
 576         }
 577
 578         ve = (struct victim_entry *)re;
 579
 580         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 581                 goto skip_node;
 582
 583         age = max_mtime - ve->mtime;
 584
 585         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 586         f2fs_bug_on(sbi, !vblocks);
 587
 588         /* rare case */
 589         if (vblocks == seg_blocks)
 590                 goto skip_node;
 591
 592         iter++;
 593
 594         age = max_mtime - abs(p->age - age);
 595         cost = UINT_MAX - vblocks;
 596
 597         if (cost < p->min_cost ||
 598                         (cost == p->min_cost && age > p->oldest_age)) {
 599                 p->min_cost = cost;
 600                 p->oldest_age = age;
 601                 p->min_segno = ve->segno;
 602         }
 603 skip_node:
 604         if (iter < dirty_threshold) {
 605                 if (stage == 0)
 606                         node = rb_prev(node);
 607                 else if (stage == 1)
 608                         node = rb_next(node);
 609                 goto next_node;
 610         }
 611 skip_stage:
 612         if (stage < 1) {
 613                 stage++;
 614                 iter = 0;
 615                 goto next_stage;
 616         }
 617 }
 618 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 619                                                 struct victim_sel_policy *p)
 620 {
 621         f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 622                                                 &sbi->am.root, true));
 623
 624         if (p->gc_mode == GC_AT)
 625                 atgc_lookup_victim(sbi, p);
 626         else if (p->alloc_mode == AT_SSR)
 627                 atssr_lookup_victim(sbi, p);
 628         else
 629                 f2fs_bug_on(sbi, 1);
 630 }
 631
 632 static void release_victim_entry(struct f2fs_sb_info *sbi)
 633 {
 634         struct atgc_management *am = &sbi->am;
 635         struct victim_entry *ve, *tmp;
 636
 637         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 638                 list_del(&ve->list);
 639                 kmem_cache_free(victim_entry_slab, ve);
 640                 am->victim_count--;
 641         }
 642
 643         am->root = RB_ROOT_CACHED;
 644
 645         f2fs_bug_on(sbi, am->victim_count);
 646         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 647 }
 648
 649 /*
 650  * This function is called from two paths.
 651  * One is garbage collection and the other is SSR segment selection.
 652  * When it is called during GC, it just gets a victim segment
 653  * and it does not remove it from dirty seglist.
 654  * When it is called from SSR segment selection, it finds a segment
 655  * which has minimum valid blocks and removes it from dirty seglist.
 656  */
 657 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 658                         unsigned int *result, int gc_type, int type,
 659                         char alloc_mode, unsigned long long age)
 660 {
 661         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 662         struct sit_info *sm = SIT_I(sbi);
 663         struct victim_sel_policy p;
 664         unsigned int secno, last_victim;
 665         unsigned int last_segment;
 666         unsigned int nsearched;
 667         bool is_atgc;
 668         int ret = 0;
 669
 670         mutex_lock(&dirty_i->seglist_lock);
 671         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 672
 673         p.alloc_mode = alloc_mode;
 674         p.age = age;
 675         p.age_threshold = sbi->am.age_threshold;
 676
 677 retry:
 678         select_policy(sbi, gc_type, type, &p);
 679         p.min_segno = NULL_SEGNO;
 680         p.oldest_age = 0;
 681         p.min_cost = get_max_cost(sbi, &p);
 682
 683         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 684         nsearched = 0;
 685
 686         if (is_atgc)
 687                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 688
 689         if (*result != NULL_SEGNO) {
 690                 if (!get_valid_blocks(sbi, *result, false)) {
 691                         ret = -ENODATA;
 692                         goto out;
 693                 }
 694
 695                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 696                         ret = -EBUSY;
 697                 else
 698                         p.min_segno = *result;
 699                 goto out;
 700         }
 701
 702         ret = -ENODATA;
 703         if (p.max_search == 0)
 704                 goto out;
 705
 706         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 707                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 708                         p.min_segno = sbi->next_victim_seg[BG_GC];
 709                         *result = p.min_segno;
 710                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 711                         goto got_result;
 712                 }
 713                 if (gc_type == FG_GC &&
 714                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 715                         p.min_segno = sbi->next_victim_seg[FG_GC];
 716                         *result = p.min_segno;
 717                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 718                         goto got_result;
 719                 }
 720         }
 721
 722         last_victim = sm->last_victim[p.gc_mode];
 723         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 724                 p.min_segno = check_bg_victims(sbi);
 725                 if (p.min_segno != NULL_SEGNO)
 726                         goto got_it;
 727         }
 728
 729         while (1) {
 730                 unsigned long cost, *dirty_bitmap;
 731                 unsigned int unit_no, segno;
 732
 733                 dirty_bitmap = p.dirty_bitmap;
 734                 unit_no = find_next_bit(dirty_bitmap,
 735                                 last_segment / p.ofs_unit,
 736                                 p.offset / p.ofs_unit);
 737                 segno = unit_no * p.ofs_unit;
 738                 if (segno >= last_segment) {
 739                         if (sm->last_victim[p.gc_mode]) {
 740                                 last_segment =
 741                                         sm->last_victim[p.gc_mode];
 742                                 sm->last_victim[p.gc_mode] = 0;
 743                                 p.offset = 0;
 744                                 continue;
 745                         }
 746                         break;
 747                 }
 748
 749                 p.offset = segno + p.ofs_unit;
 750                 nsearched++;
 751
 752 #ifdef CONFIG_F2FS_CHECK_FS
 753                 /*
 754                  * skip selecting the invalid segno (that is failed due to block
 755                  * validity check failure during GC) to avoid endless GC loop in
 756                  * such cases.
 757                  */
 758                 if (test_bit(segno, sm->invalid_segmap))
 759                         goto next;
 760 #endif
 761
 762                 secno = GET_SEC_FROM_SEG(sbi, segno);
 763
 764                 if (sec_usage_check(sbi, secno))
 765                         goto next;
 766
 767                 /* Don't touch checkpointed data */
 768                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 769                         if (p.alloc_mode == LFS) {
 770                                 /*
 771                                  * LFS is set to find source section during GC.
 772                                  * The victim should have no checkpointed data.
 773                                  */
 774                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 775                                         goto next;
 776                         } else {
 777                                 /*
 778                                  * SSR | AT_SSR are set to find target segment
 779                                  * for writes which can be full by checkpointed
 780                                  * and newly written blocks.
 781                                  */
 782                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 783                                         goto next;
 784                         }
 785                 }
 786
 787                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 788                         goto next;
 789
 790                 if (is_atgc) {
 791                         add_victim_entry(sbi, &p, segno);
 792                         goto next;
 793                 }
 794
 795                 cost = get_gc_cost(sbi, segno, &p);
 796
 797                 if (p.min_cost > cost) {
 798                         p.min_segno = segno;
 799                         p.min_cost = cost;
 800                 }
 801 next:
 802                 if (nsearched >= p.max_search) {
 803                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 804                                 sm->last_victim[p.gc_mode] =
 805                                         last_victim + p.ofs_unit;
 806                         else
 807                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 808                         sm->last_victim[p.gc_mode] %=
 809                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 810                         break;
 811                 }
 812         }
 813
 814         /* get victim for GC_AT/AT_SSR */
 815         if (is_atgc) {
 816                 lookup_victim_by_age(sbi, &p);
 817                 release_victim_entry(sbi);
 818         }
 819
 820         if (is_atgc && p.min_segno == NULL_SEGNO &&
 821                         sm->elapsed_time < p.age_threshold) {
 822                 p.age_threshold = 0;
 823                 goto retry;
 824         }
 825
 826         if (p.min_segno != NULL_SEGNO) {
 827 got_it:
 828                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 829 got_result:
 830                 if (p.alloc_mode == LFS) {
 831                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 832                         if (gc_type == FG_GC)
 833                                 sbi->cur_victim_sec = secno;
 834                         else
 835                                 set_bit(secno, dirty_i->victim_secmap);
 836                 }
 837                 ret = 0;
 838
 839         }
 840 out:
 841         if (p.min_segno != NULL_SEGNO)
 842                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 843                                 sbi->cur_victim_sec,
 844                                 prefree_segments(sbi), free_segments(sbi));
 845         mutex_unlock(&dirty_i->seglist_lock);
 846
 847         return ret;
 848 }
 849
 850 static const struct victim_selection default_v_ops = {
 851         .get_victim = get_victim_by_default,
 852 };
 853
 854 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 855 {
 856         struct inode_entry *ie;
 857
 858         ie = radix_tree_lookup(&gc_list->iroot, ino);
 859         if (ie)
 860                 return ie->inode;
 861         return NULL;
 862 }
 863
 864 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 865 {
 866         struct inode_entry *new_ie;
 867
 868         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 869                 iput(inode);
 870                 return;
 871         }
 872         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 873                                         GFP_NOFS, true, NULL);
 874         new_ie->inode = inode;
 875
 876         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 877         list_add_tail(&new_ie->list, &gc_list->ilist);
 878 }
 879
 880 static void put_gc_inode(struct gc_inode_list *gc_list)
 881 {
 882         struct inode_entry *ie, *next_ie;
 883
 884         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 885                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 886                 iput(ie->inode);
 887                 list_del(&ie->list);
 888                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 889         }
 890 }
 891
 892 static int check_valid_map(struct f2fs_sb_info *sbi,
 893                                 unsigned int segno, int offset)
 894 {
 895         struct sit_info *sit_i = SIT_I(sbi);
 896         struct seg_entry *sentry;
 897         int ret;
 898
 899         down_read(&sit_i->sentry_lock);
 900         sentry = get_seg_entry(sbi, segno);
 901         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 902         up_read(&sit_i->sentry_lock);
 903         return ret;
 904 }
 905
 906 /*
 907  * This function compares node address got in summary with that in NAT.
 908  * On validity, copy that node with cold status, otherwise (invalid node)
 909  * ignore that.
 910  */
 911 static int gc_node_segment(struct f2fs_sb_info *sbi,
 912                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 913 {
 914         struct f2fs_summary *entry;
 915         block_t start_addr;
 916         int off;
 917         int phase = 0;
 918         bool fggc = (gc_type == FG_GC);
 919         int submitted = 0;
 920         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 921
 922         start_addr = START_BLOCK(sbi, segno);
 923
 924 next_step:
 925         entry = sum;
 926
 927         if (fggc && phase == 2)
 928                 atomic_inc(&sbi->wb_sync_req[NODE]);
 929
 930         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 931                 nid_t nid = le32_to_cpu(entry->nid);
 932                 struct page *node_page;
 933                 struct node_info ni;
 934                 int err;
 935
 936                 /* stop BG_GC if there is not enough free sections. */
 937                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 938                         return submitted;
 939
 940                 if (check_valid_map(sbi, segno, off) == 0)
 941                         continue;
 942
 943                 if (phase == 0) {
 944                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 945                                                         META_NAT, true);
 946                         continue;
 947                 }
 948
 949                 if (phase == 1) {
 950                         f2fs_ra_node_page(sbi, nid);
 951                         continue;
 952                 }
 953
 954                 /* phase == 2 */
 955                 node_page = f2fs_get_node_page(sbi, nid);
 956                 if (IS_ERR(node_page))
 957                         continue;
 958
 959                 /* block may become invalid during f2fs_get_node_page */
 960                 if (check_valid_map(sbi, segno, off) == 0) {
 961                         f2fs_put_page(node_page, 1);
 962                         continue;
 963                 }
 964
 965                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
 966                         f2fs_put_page(node_page, 1);
 967                         continue;
 968                 }
 969
 970                 if (ni.blk_addr != start_addr + off) {
 971                         f2fs_put_page(node_page, 1);
 972                         continue;
 973                 }
 974
 975                 err = f2fs_move_node_page(node_page, gc_type);
 976                 if (!err && gc_type == FG_GC)
 977                         submitted++;
 978                 stat_inc_node_blk_count(sbi, 1, gc_type);
 979         }
 980
 981         if (++phase < 3)
 982                 goto next_step;
 983
 984         if (fggc)
 985                 atomic_dec(&sbi->wb_sync_req[NODE]);
 986         return submitted;
 987 }
 988
 989 /*
 990  * Calculate start block index indicating the given node offset.
 991  * Be careful, caller should give this node offset only indicating direct node
 992  * blocks. If any node offsets, which point the other types of node blocks such
 993  * as indirect or double indirect node blocks, are given, it must be a caller's
 994  * bug.
 995  */
 996 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 997 {
 998         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 999         unsigned int bidx;
1000
1001         if (node_ofs == 0)
1002                 return 0;
1003
1004         if (node_ofs <= 2) {
1005                 bidx = node_ofs - 1;
1006         } else if (node_ofs <= indirect_blks) {
1007                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1008
1009                 bidx = node_ofs - 2 - dec;
1010         } else {
1011                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1012
1013                 bidx = node_ofs - 5 - dec;
1014         }
1015         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1016 }
1017
1018 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1019                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1020 {
1021         struct page *node_page;
1022         nid_t nid;
1023         unsigned int ofs_in_node;
1024         block_t source_blkaddr;
1025
1026         nid = le32_to_cpu(sum->nid);
1027         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1028
1029         node_page = f2fs_get_node_page(sbi, nid);
1030         if (IS_ERR(node_page))
1031                 return false;
1032
1033         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1034                 f2fs_put_page(node_page, 1);
1035                 return false;
1036         }
1037
1038         if (sum->version != dni->version) {
1039                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1040                           __func__);
1041                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1042         }
1043
1044         if (f2fs_check_nid_range(sbi, dni->ino)) {
1045                 f2fs_put_page(node_page, 1);
1046                 return false;
1047         }
1048
1049         *nofs = ofs_of_node(node_page);
1050         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1051         f2fs_put_page(node_page, 1);
1052
1053         if (source_blkaddr != blkaddr) {
1054 #ifdef CONFIG_F2FS_CHECK_FS
1055                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1056                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1057
1058                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1059                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1060                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1061                                          blkaddr, source_blkaddr, segno);
1062                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1063                         }
1064                 }
1065 #endif
1066                 return false;
1067         }
1068         return true;
1069 }
1070
1071 static int ra_data_block(struct inode *inode, pgoff_t index)
1072 {
1073         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1074         struct address_space *mapping = inode->i_mapping;
1075         struct dnode_of_data dn;
1076         struct page *page;
1077         struct extent_info ei = {0, 0, 0};
1078         struct f2fs_io_info fio = {
1079                 .sbi = sbi,
1080                 .ino = inode->i_ino,
1081                 .type = DATA,
1082                 .temp = COLD,
1083                 .op = REQ_OP_READ,
1084                 .op_flags = 0,
1085                 .encrypted_page = NULL,
1086                 .in_list = false,
1087                 .retry = false,
1088         };
1089         int err;
1090
1091         page = f2fs_grab_cache_page(mapping, index, true);
1092         if (!page)
1093                 return -ENOMEM;
1094
1095         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1096                 dn.data_blkaddr = ei.blk + index - ei.fofs;
1097                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1098                                                 DATA_GENERIC_ENHANCE_READ))) {
1099                         err = -EFSCORRUPTED;
1100                         goto put_page;
1101                 }
1102                 goto got_it;
1103         }
1104
1105         set_new_dnode(&dn, inode, NULL, NULL, 0);
1106         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1107         if (err)
1108                 goto put_page;
1109         f2fs_put_dnode(&dn);
1110
1111         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1112                 err = -ENOENT;
1113                 goto put_page;
1114         }
1115         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1116                                                 DATA_GENERIC_ENHANCE))) {
1117                 err = -EFSCORRUPTED;
1118                 goto put_page;
1119         }
1120 got_it:
1121         /* read page */
1122         fio.page = page;
1123         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1124
1125         /*
1126          * don't cache encrypted data into meta inode until previous dirty
1127          * data were writebacked to avoid racing between GC and flush.
1128          */
1129         f2fs_wait_on_page_writeback(page, DATA, true, true);
1130
1131         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1132
1133         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1134                                         dn.data_blkaddr,
1135                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1136         if (!fio.encrypted_page) {
1137                 err = -ENOMEM;
1138                 goto put_page;
1139         }
1140
1141         err = f2fs_submit_page_bio(&fio);
1142         if (err)
1143                 goto put_encrypted_page;
1144         f2fs_put_page(fio.encrypted_page, 0);
1145         f2fs_put_page(page, 1);
1146
1147         f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1148         f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1149
1150         return 0;
1151 put_encrypted_page:
1152         f2fs_put_page(fio.encrypted_page, 1);
1153 put_page:
1154         f2fs_put_page(page, 1);
1155         return err;
1156 }
1157
1158 /*
1159  * Move data block via META_MAPPING while keeping locked data page.
1160  * This can be used to move blocks, aka LBAs, directly on disk.
1161  */
1162 static int move_data_block(struct inode *inode, block_t bidx,
1163                                 int gc_type, unsigned int segno, int off)
1164 {
1165         struct f2fs_io_info fio = {
1166                 .sbi = F2FS_I_SB(inode),
1167                 .ino = inode->i_ino,
1168                 .type = DATA,
1169                 .temp = COLD,
1170                 .op = REQ_OP_READ,
1171                 .op_flags = 0,
1172                 .encrypted_page = NULL,
1173                 .in_list = false,
1174                 .retry = false,
1175         };
1176         struct dnode_of_data dn;
1177         struct f2fs_summary sum;
1178         struct node_info ni;
1179         struct page *page, *mpage;
1180         block_t newaddr;
1181         int err = 0;
1182         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1183         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1184                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1185                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1186
1187         /* do not read out */
1188         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1189         if (!page)
1190                 return -ENOMEM;
1191
1192         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1193                 err = -ENOENT;
1194                 goto out;
1195         }
1196
1197         if (f2fs_is_atomic_file(inode)) {
1198                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1199                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1200                 err = -EAGAIN;
1201                 goto out;
1202         }
1203
1204         if (f2fs_is_pinned_file(inode)) {
1205                 f2fs_pin_file_control(inode, true);
1206                 err = -EAGAIN;
1207                 goto out;
1208         }
1209
1210         set_new_dnode(&dn, inode, NULL, NULL, 0);
1211         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1212         if (err)
1213                 goto out;
1214
1215         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1216                 ClearPageUptodate(page);
1217                 err = -ENOENT;
1218                 goto put_out;
1219         }
1220
1221         /*
1222          * don't cache encrypted data into meta inode until previous dirty
1223          * data were writebacked to avoid racing between GC and flush.
1224          */
1225         f2fs_wait_on_page_writeback(page, DATA, true, true);
1226
1227         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1228
1229         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1230         if (err)
1231                 goto put_out;
1232
1233         /* read page */
1234         fio.page = page;
1235         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1236
1237         if (lfs_mode)
1238                 f2fs_down_write(&fio.sbi->io_order_lock);
1239
1240         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1241                                         fio.old_blkaddr, false);
1242         if (!mpage) {
1243                 err = -ENOMEM;
1244                 goto up_out;
1245         }
1246
1247         fio.encrypted_page = mpage;
1248
1249         /* read source block in mpage */
1250         if (!PageUptodate(mpage)) {
1251                 err = f2fs_submit_page_bio(&fio);
1252                 if (err) {
1253                         f2fs_put_page(mpage, 1);
1254                         goto up_out;
1255                 }
1256
1257                 f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1258                 f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1259
1260                 lock_page(mpage);
1261                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1262                                                 !PageUptodate(mpage))) {
1263                         err = -EIO;
1264                         f2fs_put_page(mpage, 1);
1265                         goto up_out;
1266                 }
1267         }
1268
1269         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1270
1271         /* allocate block address */
1272         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1273                                 &sum, type, NULL);
1274
1275         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1276                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1277         if (!fio.encrypted_page) {
1278                 err = -ENOMEM;
1279                 f2fs_put_page(mpage, 1);
1280                 goto recover_block;
1281         }
1282
1283         /* write target block */
1284         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1285         memcpy(page_address(fio.encrypted_page),
1286                                 page_address(mpage), PAGE_SIZE);
1287         f2fs_put_page(mpage, 1);
1288         invalidate_mapping_pages(META_MAPPING(fio.sbi),
1289                                 fio.old_blkaddr, fio.old_blkaddr);
1290         f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1291
1292         set_page_dirty(fio.encrypted_page);
1293         if (clear_page_dirty_for_io(fio.encrypted_page))
1294                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1295
1296         set_page_writeback(fio.encrypted_page);
1297         ClearPageError(page);
1298
1299         fio.op = REQ_OP_WRITE;
1300         fio.op_flags = REQ_SYNC;
1301         fio.new_blkaddr = newaddr;
1302         f2fs_submit_page_write(&fio);
1303         if (fio.retry) {
1304                 err = -EAGAIN;
1305                 if (PageWriteback(fio.encrypted_page))
1306                         end_page_writeback(fio.encrypted_page);
1307                 goto put_page_out;
1308         }
1309
1310         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1311
1312         f2fs_update_data_blkaddr(&dn, newaddr);
1313         set_inode_flag(inode, FI_APPEND_WRITE);
1314         if (page->index == 0)
1315                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1316 put_page_out:
1317         f2fs_put_page(fio.encrypted_page, 1);
1318 recover_block:
1319         if (err)
1320                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1321                                                         true, true, true);
1322 up_out:
1323         if (lfs_mode)
1324                 f2fs_up_write(&fio.sbi->io_order_lock);
1325 put_out:
1326         f2fs_put_dnode(&dn);
1327 out:
1328         f2fs_put_page(page, 1);
1329         return err;
1330 }
1331
1332 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1333                                                         unsigned int segno, int off)
1334 {
1335         struct page *page;
1336         int err = 0;
1337
1338         page = f2fs_get_lock_data_page(inode, bidx, true);
1339         if (IS_ERR(page))
1340                 return PTR_ERR(page);
1341
1342         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1343                 err = -ENOENT;
1344                 goto out;
1345         }
1346
1347         if (f2fs_is_atomic_file(inode)) {
1348                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1349                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1350                 err = -EAGAIN;
1351                 goto out;
1352         }
1353         if (f2fs_is_pinned_file(inode)) {
1354                 if (gc_type == FG_GC)
1355                         f2fs_pin_file_control(inode, true);
1356                 err = -EAGAIN;
1357                 goto out;
1358         }
1359
1360         if (gc_type == BG_GC) {
1361                 if (PageWriteback(page)) {
1362                         err = -EAGAIN;
1363                         goto out;
1364                 }
1365                 set_page_dirty(page);
1366                 set_page_private_gcing(page);
1367         } else {
1368                 struct f2fs_io_info fio = {
1369                         .sbi = F2FS_I_SB(inode),
1370                         .ino = inode->i_ino,
1371                         .type = DATA,
1372                         .temp = COLD,
1373                         .op = REQ_OP_WRITE,
1374                         .op_flags = REQ_SYNC,
1375                         .old_blkaddr = NULL_ADDR,
1376                         .page = page,
1377                         .encrypted_page = NULL,
1378                         .need_lock = LOCK_REQ,
1379                         .io_type = FS_GC_DATA_IO,
1380                 };
1381                 bool is_dirty = PageDirty(page);
1382
1383 retry:
1384                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1385
1386                 set_page_dirty(page);
1387                 if (clear_page_dirty_for_io(page)) {
1388                         inode_dec_dirty_pages(inode);
1389                         f2fs_remove_dirty_inode(inode);
1390                 }
1391
1392                 set_page_private_gcing(page);
1393
1394                 err = f2fs_do_write_data_page(&fio);
1395                 if (err) {
1396                         clear_page_private_gcing(page);
1397                         if (err == -ENOMEM) {
1398                                 memalloc_retry_wait(GFP_NOFS);
1399                                 goto retry;
1400                         }
1401                         if (is_dirty)
1402                                 set_page_dirty(page);
1403                 }
1404         }
1405 out:
1406         f2fs_put_page(page, 1);
1407         return err;
1408 }
1409
1410 /*
1411  * This function tries to get parent node of victim data block, and identifies
1412  * data block validity. If the block is valid, copy that with cold status and
1413  * modify parent node.
1414  * If the parent node is not valid or the data block address is different,
1415  * the victim data block is ignored.
1416  */
1417 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1418                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1419                 bool force_migrate)
1420 {
1421         struct super_block *sb = sbi->sb;
1422         struct f2fs_summary *entry;
1423         block_t start_addr;
1424         int off;
1425         int phase = 0;
1426         int submitted = 0;
1427         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1428
1429         start_addr = START_BLOCK(sbi, segno);
1430
1431 next_step:
1432         entry = sum;
1433
1434         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1435                 struct page *data_page;
1436                 struct inode *inode;
1437                 struct node_info dni; /* dnode info for the data */
1438                 unsigned int ofs_in_node, nofs;
1439                 block_t start_bidx;
1440                 nid_t nid = le32_to_cpu(entry->nid);
1441
1442                 /*
1443                  * stop BG_GC if there is not enough free sections.
1444                  * Or, stop GC if the segment becomes fully valid caused by
1445                  * race condition along with SSR block allocation.
1446                  */
1447                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1448                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1449                                                         BLKS_PER_SEC(sbi)))
1450                         return submitted;
1451
1452                 if (check_valid_map(sbi, segno, off) == 0)
1453                         continue;
1454
1455                 if (phase == 0) {
1456                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1457                                                         META_NAT, true);
1458                         continue;
1459                 }
1460
1461                 if (phase == 1) {
1462                         f2fs_ra_node_page(sbi, nid);
1463                         continue;
1464                 }
1465
1466                 /* Get an inode by ino with checking validity */
1467                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1468                         continue;
1469
1470                 if (phase == 2) {
1471                         f2fs_ra_node_page(sbi, dni.ino);
1472                         continue;
1473                 }
1474
1475                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1476
1477                 if (phase == 3) {
1478                         inode = f2fs_iget(sb, dni.ino);
1479                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1480                                         special_file(inode->i_mode))
1481                                 continue;
1482
1483                         if (!f2fs_down_write_trylock(
1484                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1485                                 iput(inode);
1486                                 sbi->skipped_gc_rwsem++;
1487                                 continue;
1488                         }
1489
1490                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1491                                                                 ofs_in_node;
1492
1493                         if (f2fs_post_read_required(inode)) {
1494                                 int err = ra_data_block(inode, start_bidx);
1495
1496                                 f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1497                                 if (err) {
1498                                         iput(inode);
1499                                         continue;
1500                                 }
1501                                 add_gc_inode(gc_list, inode);
1502                                 continue;
1503                         }
1504
1505                         data_page = f2fs_get_read_data_page(inode,
1506                                                 start_bidx, REQ_RAHEAD, true);
1507                         f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1508                         if (IS_ERR(data_page)) {
1509                                 iput(inode);
1510                                 continue;
1511                         }
1512
1513                         f2fs_put_page(data_page, 0);
1514                         add_gc_inode(gc_list, inode);
1515                         continue;
1516                 }
1517
1518                 /* phase 4 */
1519                 inode = find_gc_inode(gc_list, dni.ino);
1520                 if (inode) {
1521                         struct f2fs_inode_info *fi = F2FS_I(inode);
1522                         bool locked = false;
1523                         int err;
1524
1525                         if (S_ISREG(inode->i_mode)) {
1526                                 if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[READ])) {
1527                                         sbi->skipped_gc_rwsem++;
1528                                         continue;
1529                                 }
1530                                 if (!f2fs_down_write_trylock(
1531                                                 &fi->i_gc_rwsem[WRITE])) {
1532                                         sbi->skipped_gc_rwsem++;
1533                                         f2fs_up_write(&fi->i_gc_rwsem[READ]);
1534                                         continue;
1535                                 }
1536                                 locked = true;
1537
1538                                 /* wait for all inflight aio data */
1539                                 inode_dio_wait(inode);
1540                         }
1541
1542                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1543                                                                 + ofs_in_node;
1544                         if (f2fs_post_read_required(inode))
1545                                 err = move_data_block(inode, start_bidx,
1546                                                         gc_type, segno, off);
1547                         else
1548                                 err = move_data_page(inode, start_bidx, gc_type,
1549                                                                 segno, off);
1550
1551                         if (!err && (gc_type == FG_GC ||
1552                                         f2fs_post_read_required(inode)))
1553                                 submitted++;
1554
1555                         if (locked) {
1556                                 f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1557                                 f2fs_up_write(&fi->i_gc_rwsem[READ]);
1558                         }
1559
1560                         stat_inc_data_blk_count(sbi, 1, gc_type);
1561                 }
1562         }
1563
1564         if (++phase < 5)
1565                 goto next_step;
1566
1567         return submitted;
1568 }
1569
1570 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1571                         int gc_type)
1572 {
1573         struct sit_info *sit_i = SIT_I(sbi);
1574         int ret;
1575
1576         down_write(&sit_i->sentry_lock);
1577         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1578                                               NO_CHECK_TYPE, LFS, 0);
1579         up_write(&sit_i->sentry_lock);
1580         return ret;
1581 }
1582
1583 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1584                                 unsigned int start_segno,
1585                                 struct gc_inode_list *gc_list, int gc_type,
1586                                 bool force_migrate)
1587 {
1588         struct page *sum_page;
1589         struct f2fs_summary_block *sum;
1590         struct blk_plug plug;
1591         unsigned int segno = start_segno;
1592         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1593         int seg_freed = 0, migrated = 0;
1594         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1595                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1596         int submitted = 0;
1597
1598         if (__is_large_section(sbi))
1599                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1600
1601         /*
1602          * zone-capacity can be less than zone-size in zoned devices,
1603          * resulting in less than expected usable segments in the zone,
1604          * calculate the end segno in the zone which can be garbage collected
1605          */
1606         if (f2fs_sb_has_blkzoned(sbi))
1607                 end_segno -= sbi->segs_per_sec -
1608                                         f2fs_usable_segs_in_sec(sbi, segno);
1609
1610         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1611
1612         /* readahead multi ssa blocks those have contiguous address */
1613         if (__is_large_section(sbi))
1614                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1615                                         end_segno - segno, META_SSA, true);
1616
1617         /* reference all summary page */
1618         while (segno < end_segno) {
1619                 sum_page = f2fs_get_sum_page(sbi, segno++);
1620                 if (IS_ERR(sum_page)) {
1621                         int err = PTR_ERR(sum_page);
1622
1623                         end_segno = segno - 1;
1624                         for (segno = start_segno; segno < end_segno; segno++) {
1625                                 sum_page = find_get_page(META_MAPPING(sbi),
1626                                                 GET_SUM_BLOCK(sbi, segno));
1627                                 f2fs_put_page(sum_page, 0);
1628                                 f2fs_put_page(sum_page, 0);
1629                         }
1630                         return err;
1631                 }
1632                 unlock_page(sum_page);
1633         }
1634
1635         blk_start_plug(&plug);
1636
1637         for (segno = start_segno; segno < end_segno; segno++) {
1638
1639                 /* find segment summary of victim */
1640                 sum_page = find_get_page(META_MAPPING(sbi),
1641                                         GET_SUM_BLOCK(sbi, segno));
1642                 f2fs_put_page(sum_page, 0);
1643
1644                 if (get_valid_blocks(sbi, segno, false) == 0)
1645                         goto freed;
1646                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1647                                 migrated >= sbi->migration_granularity)
1648                         goto skip;
1649                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1650                         goto skip;
1651
1652                 sum = page_address(sum_page);
1653                 if (type != GET_SUM_TYPE((&sum->footer))) {
1654                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1655                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1656                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1657                         f2fs_stop_checkpoint(sbi, false);
1658                         goto skip;
1659                 }
1660
1661                 /*
1662                  * this is to avoid deadlock:
1663                  * - lock_page(sum_page)         - f2fs_replace_block
1664                  *  - check_valid_map()            - down_write(sentry_lock)
1665                  *   - down_read(sentry_lock)     - change_curseg()
1666                  *                                  - lock_page(sum_page)
1667                  */
1668                 if (type == SUM_TYPE_NODE)
1669                         submitted += gc_node_segment(sbi, sum->entries, segno,
1670                                                                 gc_type);
1671                 else
1672                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1673                                                         segno, gc_type,
1674                                                         force_migrate);
1675
1676                 stat_inc_seg_count(sbi, type, gc_type);
1677                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1678                 migrated++;
1679
1680 freed:
1681                 if (gc_type == FG_GC &&
1682                                 get_valid_blocks(sbi, segno, false) == 0)
1683                         seg_freed++;
1684
1685                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1686                         sbi->next_victim_seg[gc_type] = segno + 1;
1687 skip:
1688                 f2fs_put_page(sum_page, 0);
1689         }
1690
1691         if (submitted)
1692                 f2fs_submit_merged_write(sbi,
1693                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1694
1695         blk_finish_plug(&plug);
1696
1697         stat_inc_call_count(sbi->stat_info);
1698
1699         return seg_freed;
1700 }
1701
1702 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1703                         bool background, bool force, unsigned int segno)
1704 {
1705         int gc_type = sync ? FG_GC : BG_GC;
1706         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1707         int ret = 0;
1708         struct cp_control cpc;
1709         unsigned int init_segno = segno;
1710         struct gc_inode_list gc_list = {
1711                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1712                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1713         };
1714         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1715         unsigned long long first_skipped;
1716         unsigned int skipped_round = 0, round = 0;
1717
1718         trace_f2fs_gc_begin(sbi->sb, sync, background,
1719                                 get_pages(sbi, F2FS_DIRTY_NODES),
1720                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1721                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1722                                 free_sections(sbi),
1723                                 free_segments(sbi),
1724                                 reserved_segments(sbi),
1725                                 prefree_segments(sbi));
1726
1727         cpc.reason = __get_cp_reason(sbi);
1728         sbi->skipped_gc_rwsem = 0;
1729         first_skipped = last_skipped;
1730 gc_more:
1731         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1732                 ret = -EINVAL;
1733                 goto stop;
1734         }
1735         if (unlikely(f2fs_cp_error(sbi))) {
1736                 ret = -EIO;
1737                 goto stop;
1738         }
1739
1740         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1741                 /*
1742                  * For example, if there are many prefree_segments below given
1743                  * threshold, we can make them free by checkpoint. Then, we
1744                  * secure free segments which doesn't need fggc any more.
1745                  */
1746                 if (prefree_segments(sbi) &&
1747                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1748                         ret = f2fs_write_checkpoint(sbi, &cpc);
1749                         if (ret)
1750                                 goto stop;
1751                 }
1752                 if (has_not_enough_free_secs(sbi, 0, 0))
1753                         gc_type = FG_GC;
1754         }
1755
1756         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1757         if (gc_type == BG_GC && !background) {
1758                 ret = -EINVAL;
1759                 goto stop;
1760         }
1761         ret = __get_victim(sbi, &segno, gc_type);
1762         if (ret)
1763                 goto stop;
1764
1765         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1766         if (gc_type == FG_GC &&
1767                 seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1768                 sec_freed++;
1769         total_freed += seg_freed;
1770
1771         if (gc_type == FG_GC) {
1772                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1773                                                 sbi->skipped_gc_rwsem)
1774                         skipped_round++;
1775                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1776                 round++;
1777         }
1778
1779         if (gc_type == FG_GC)
1780                 sbi->cur_victim_sec = NULL_SEGNO;
1781
1782         if (sync)
1783                 goto stop;
1784
1785         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1786                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1787                                         skipped_round * 2 < round) {
1788                         segno = NULL_SEGNO;
1789                         goto gc_more;
1790                 }
1791
1792                 if (first_skipped < last_skipped &&
1793                                 (last_skipped - first_skipped) >
1794                                                 sbi->skipped_gc_rwsem) {
1795                         f2fs_drop_inmem_pages_all(sbi, true);
1796                         segno = NULL_SEGNO;
1797                         goto gc_more;
1798                 }
1799                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1800                         ret = f2fs_write_checkpoint(sbi, &cpc);
1801         }
1802 stop:
1803         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1804         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1805
1806         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1807                                 get_pages(sbi, F2FS_DIRTY_NODES),
1808                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1809                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1810                                 free_sections(sbi),
1811                                 free_segments(sbi),
1812                                 reserved_segments(sbi),
1813                                 prefree_segments(sbi));
1814
1815         f2fs_up_write(&sbi->gc_lock);
1816
1817         put_gc_inode(&gc_list);
1818
1819         if (sync && !ret)
1820                 ret = sec_freed ? 0 : -EAGAIN;
1821         return ret;
1822 }
1823
1824 int __init f2fs_create_garbage_collection_cache(void)
1825 {
1826         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1827                                         sizeof(struct victim_entry));
1828         if (!victim_entry_slab)
1829                 return -ENOMEM;
1830         return 0;
1831 }
1832
1833 void f2fs_destroy_garbage_collection_cache(void)
1834 {
1835         kmem_cache_destroy(victim_entry_slab);
1836 }
1837
1838 static void init_atgc_management(struct f2fs_sb_info *sbi)
1839 {
1840         struct atgc_management *am = &sbi->am;
1841
1842         if (test_opt(sbi, ATGC) &&
1843                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1844                 am->atgc_enabled = true;
1845
1846         am->root = RB_ROOT_CACHED;
1847         INIT_LIST_HEAD(&am->victim_list);
1848         am->victim_count = 0;
1849
1850         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1851         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1852         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1853         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1854 }
1855
1856 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1857 {
1858         DIRTY_I(sbi)->v_ops = &default_v_ops;
1859
1860         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1861
1862         /* give warm/cold data area from slower device */
1863         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1864                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1865                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1866
1867         init_atgc_management(sbi);
1868 }
1869
1870 static int free_segment_range(struct f2fs_sb_info *sbi,
1871                                 unsigned int secs, bool gc_only)
1872 {
1873         unsigned int segno, next_inuse, start, end;
1874         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1875         int gc_mode, gc_type;
1876         int err = 0;
1877         int type;
1878
1879         /* Force block allocation for GC */
1880         MAIN_SECS(sbi) -= secs;
1881         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1882         end = MAIN_SEGS(sbi) - 1;
1883
1884         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1885         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1886                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1887                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1888
1889         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1890                 if (sbi->next_victim_seg[gc_type] >= start)
1891                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1892         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1893
1894         /* Move out cursegs from the target range */
1895         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1896                 f2fs_allocate_segment_for_resize(sbi, type, start, end);
1897
1898         /* do GC to move out valid blocks in the range */
1899         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1900                 struct gc_inode_list gc_list = {
1901                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1902                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1903                 };
1904
1905                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1906                 put_gc_inode(&gc_list);
1907
1908                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1909                         err = -EAGAIN;
1910                         goto out;
1911                 }
1912                 if (fatal_signal_pending(current)) {
1913                         err = -ERESTARTSYS;
1914                         goto out;
1915                 }
1916         }
1917         if (gc_only)
1918                 goto out;
1919
1920         err = f2fs_write_checkpoint(sbi, &cpc);
1921         if (err)
1922                 goto out;
1923
1924         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1925         if (next_inuse <= end) {
1926                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1927                          next_inuse);
1928                 f2fs_bug_on(sbi, 1);
1929         }
1930 out:
1931         MAIN_SECS(sbi) += secs;
1932         return err;
1933 }
1934
1935 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1936 {
1937         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1938         int section_count;
1939         int segment_count;
1940         int segment_count_main;
1941         long long block_count;
1942         int segs = secs * sbi->segs_per_sec;
1943
1944         f2fs_down_write(&sbi->sb_lock);
1945
1946         section_count = le32_to_cpu(raw_sb->section_count);
1947         segment_count = le32_to_cpu(raw_sb->segment_count);
1948         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1949         block_count = le64_to_cpu(raw_sb->block_count);
1950
1951         raw_sb->section_count = cpu_to_le32(section_count + secs);
1952         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1953         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1954         raw_sb->block_count = cpu_to_le64(block_count +
1955                                         (long long)segs * sbi->blocks_per_seg);
1956         if (f2fs_is_multi_device(sbi)) {
1957                 int last_dev = sbi->s_ndevs - 1;
1958                 int dev_segs =
1959                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1960
1961                 raw_sb->devs[last_dev].total_segments =
1962                                                 cpu_to_le32(dev_segs + segs);
1963         }
1964
1965         f2fs_up_write(&sbi->sb_lock);
1966 }
1967
1968 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1969 {
1970         int segs = secs * sbi->segs_per_sec;
1971         long long blks = (long long)segs * sbi->blocks_per_seg;
1972         long long user_block_count =
1973                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1974
1975         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1976         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1977         MAIN_SECS(sbi) += secs;
1978         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1979         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1980         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1981
1982         if (f2fs_is_multi_device(sbi)) {
1983                 int last_dev = sbi->s_ndevs - 1;
1984
1985                 FDEV(last_dev).total_segments =
1986                                 (int)FDEV(last_dev).total_segments + segs;
1987                 FDEV(last_dev).end_blk =
1988                                 (long long)FDEV(last_dev).end_blk + blks;
1989 #ifdef CONFIG_BLK_DEV_ZONED
1990                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1991                                         (int)(blks >> sbi->log_blocks_per_blkz);
1992 #endif
1993         }
1994 }
1995
1996 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1997 {
1998         __u64 old_block_count, shrunk_blocks;
1999         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2000         unsigned int secs;
2001         int err = 0;
2002         __u32 rem;
2003
2004         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2005         if (block_count > old_block_count)
2006                 return -EINVAL;
2007
2008         if (f2fs_is_multi_device(sbi)) {
2009                 int last_dev = sbi->s_ndevs - 1;
2010                 __u64 last_segs = FDEV(last_dev).total_segments;
2011
2012                 if (block_count + last_segs * sbi->blocks_per_seg <=
2013                                                                 old_block_count)
2014                         return -EINVAL;
2015         }
2016
2017         /* new fs size should align to section size */
2018         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2019         if (rem)
2020                 return -EINVAL;
2021
2022         if (block_count == old_block_count)
2023                 return 0;
2024
2025         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2026                 f2fs_err(sbi, "Should run fsck to repair first.");
2027                 return -EFSCORRUPTED;
2028         }
2029
2030         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2031                 f2fs_err(sbi, "Checkpoint should be enabled.");
2032                 return -EINVAL;
2033         }
2034
2035         shrunk_blocks = old_block_count - block_count;
2036         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2037
2038         /* stop other GC */
2039         if (!f2fs_down_write_trylock(&sbi->gc_lock))
2040                 return -EAGAIN;
2041
2042         /* stop CP to protect MAIN_SEC in free_segment_range */
2043         f2fs_lock_op(sbi);
2044
2045         spin_lock(&sbi->stat_lock);
2046         if (shrunk_blocks + valid_user_blocks(sbi) +
2047                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2048                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2049                 err = -ENOSPC;
2050         spin_unlock(&sbi->stat_lock);
2051
2052         if (err)
2053                 goto out_unlock;
2054
2055         err = free_segment_range(sbi, secs, true);
2056
2057 out_unlock:
2058         f2fs_unlock_op(sbi);
2059         f2fs_up_write(&sbi->gc_lock);
2060         if (err)
2061                 return err;
2062
2063         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2064
2065         freeze_super(sbi->sb);
2066         f2fs_down_write(&sbi->gc_lock);
2067         f2fs_down_write(&sbi->cp_global_sem);
2068
2069         spin_lock(&sbi->stat_lock);
2070         if (shrunk_blocks + valid_user_blocks(sbi) +
2071                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2072                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2073                 err = -ENOSPC;
2074         else
2075                 sbi->user_block_count -= shrunk_blocks;
2076         spin_unlock(&sbi->stat_lock);
2077         if (err)
2078                 goto out_err;
2079
2080         err = free_segment_range(sbi, secs, false);
2081         if (err)
2082                 goto recover_out;
2083
2084         update_sb_metadata(sbi, -secs);
2085
2086         err = f2fs_commit_super(sbi, false);
2087         if (err) {
2088                 update_sb_metadata(sbi, secs);
2089                 goto recover_out;
2090         }
2091
2092         update_fs_metadata(sbi, -secs);
2093         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2094         set_sbi_flag(sbi, SBI_IS_DIRTY);
2095
2096         err = f2fs_write_checkpoint(sbi, &cpc);
2097         if (err) {
2098                 update_fs_metadata(sbi, secs);
2099                 update_sb_metadata(sbi, secs);
2100                 f2fs_commit_super(sbi, false);
2101         }
2102 recover_out:
2103         if (err) {
2104                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2105                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2106
2107                 spin_lock(&sbi->stat_lock);
2108                 sbi->user_block_count += shrunk_blocks;
2109                 spin_unlock(&sbi->stat_lock);
2110         }
2111 out_err:
2112         f2fs_up_write(&sbi->cp_global_sem);
2113         f2fs_up_write(&sbi->gc_lock);
2114         thaw_super(sbi->sb);
2115         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2116         return err;
2117 }