fs/f2fs/gc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * fs/f2fs/gc.c
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/module.h>
  10 #include <linux/init.h>
  11 #include <linux/f2fs_fs.h>
  12 #include <linux/kthread.h>
  13 #include <linux/delay.h>
  14 #include <linux/freezer.h>
  15 #include <linux/sched/signal.h>
  16 #include <linux/random.h>
  17 #include <linux/sched/mm.h>
  18
  19 #include "f2fs.h"
  20 #include "node.h"
  21 #include "segment.h"
  22 #include "gc.h"
  23 #include "iostat.h"
  24 #include <trace/events/f2fs.h>
  25
  26 static struct kmem_cache *victim_entry_slab;
  27
  28 static unsigned int count_bits(const unsigned long *addr,
  29                                 unsigned int offset, unsigned int len);
  30
  31 static int gc_thread_func(void *data)
  32 {
  33         struct f2fs_sb_info *sbi = data;
  34         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  35         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  36         wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
  37         unsigned int wait_ms;
  38         struct f2fs_gc_control gc_control = {
  39                 .victim_segno = NULL_SEGNO,
  40                 .should_migrate_blocks = false,
  41                 .err_gc_skipped = false };
  42
  43         wait_ms = gc_th->min_sleep_time;
  44
  45         set_freezable();
  46         do {
  47                 bool sync_mode, foreground = false;
  48
  49                 wait_event_interruptible_timeout(*wq,
  50                                 kthread_should_stop() || freezing(current) ||
  51                                 waitqueue_active(fggc_wq) ||
  52                                 gc_th->gc_wake,
  53                                 msecs_to_jiffies(wait_ms));
  54
  55                 if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
  56                         foreground = true;
  57
  58                 /* give it a try one time */
  59                 if (gc_th->gc_wake)
  60                         gc_th->gc_wake = 0;
  61
  62                 if (try_to_freeze()) {
  63                         stat_other_skip_bggc_count(sbi);
  64                         continue;
  65                 }
  66                 if (kthread_should_stop())
  67                         break;
  68
  69                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  70                         increase_sleep_time(gc_th, &wait_ms);
  71                         stat_other_skip_bggc_count(sbi);
  72                         continue;
  73                 }
  74
  75                 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  76                         f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  77                         f2fs_stop_checkpoint(sbi, false,
  78                                         STOP_CP_REASON_FAULT_INJECT);
  79                 }
  80
  81                 if (!sb_start_write_trylock(sbi->sb)) {
  82                         stat_other_skip_bggc_count(sbi);
  83                         continue;
  84                 }
  85
  86                 /*
  87                  * [GC triggering condition]
  88                  * 0. GC is not conducted currently.
  89                  * 1. There are enough dirty segments.
  90                  * 2. IO subsystem is idle by checking the # of writeback pages.
  91                  * 3. IO subsystem is idle by checking the # of requests in
  92                  *    bdev's request list.
  93                  *
  94                  * Note) We have to avoid triggering GCs frequently.
  95                  * Because it is possible that some segments can be
  96                  * invalidated soon after by user update or deletion.
  97                  * So, I'd like to wait some time to collect dirty segments.
  98                  */
  99                 if (sbi->gc_mode == GC_URGENT_HIGH ||
 100                                 sbi->gc_mode == GC_URGENT_MID) {
 101                         wait_ms = gc_th->urgent_sleep_time;
 102                         f2fs_down_write(&sbi->gc_lock);
 103                         goto do_gc;
 104                 }
 105
 106                 if (foreground) {
 107                         f2fs_down_write(&sbi->gc_lock);
 108                         goto do_gc;
 109                 } else if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
 110                         stat_other_skip_bggc_count(sbi);
 111                         goto next;
 112                 }
 113
 114                 if (!is_idle(sbi, GC_TIME)) {
 115                         increase_sleep_time(gc_th, &wait_ms);
 116                         f2fs_up_write(&sbi->gc_lock);
 117                         stat_io_skip_bggc_count(sbi);
 118                         goto next;
 119                 }
 120
 121                 if (has_enough_invalid_blocks(sbi))
 122                         decrease_sleep_time(gc_th, &wait_ms);
 123                 else
 124                         increase_sleep_time(gc_th, &wait_ms);
 125 do_gc:
 126                 if (!foreground)
 127                         stat_inc_bggc_count(sbi->stat_info);
 128
 129                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 130
 131                 /* foreground GC was been triggered via f2fs_balance_fs() */
 132                 if (foreground)
 133                         sync_mode = false;
 134
 135                 gc_control.init_gc_type = sync_mode ? FG_GC : BG_GC;
 136                 gc_control.no_bg_gc = foreground;
 137                 gc_control.nr_free_secs = foreground ? 1 : 0;
 138
 139                 /* if return value is not zero, no victim was selected */
 140                 if (f2fs_gc(sbi, &gc_control)) {
 141                         /* don't bother wait_ms by foreground gc */
 142                         if (!foreground)
 143                                 wait_ms = gc_th->no_gc_sleep_time;
 144                 }
 145
 146                 if (foreground)
 147                         wake_up_all(&gc_th->fggc_wq);
 148
 149                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 150                                 prefree_segments(sbi), free_segments(sbi));
 151
 152                 /* balancing f2fs's metadata periodically */
 153                 f2fs_balance_fs_bg(sbi, true);
 154 next:
 155                 if (sbi->gc_mode == GC_URGENT_HIGH) {
 156                         spin_lock(&sbi->gc_urgent_high_lock);
 157                         if (sbi->gc_urgent_high_remaining) {
 158                                 sbi->gc_urgent_high_remaining--;
 159                                 if (!sbi->gc_urgent_high_remaining)
 160                                         sbi->gc_mode = GC_NORMAL;
 161                         }
 162                         spin_unlock(&sbi->gc_urgent_high_lock);
 163                 }
 164                 sb_end_write(sbi->sb);
 165
 166         } while (!kthread_should_stop());
 167         return 0;
 168 }
 169
 170 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 171 {
 172         struct f2fs_gc_kthread *gc_th;
 173         dev_t dev = sbi->sb->s_bdev->bd_dev;
 174         int err = 0;
 175
 176         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 177         if (!gc_th) {
 178                 err = -ENOMEM;
 179                 goto out;
 180         }
 181
 182         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 183         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 184         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 185         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 186
 187         gc_th->gc_wake = 0;
 188
 189         sbi->gc_thread = gc_th;
 190         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 191         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 192         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 193                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 194         if (IS_ERR(gc_th->f2fs_gc_task)) {
 195                 err = PTR_ERR(gc_th->f2fs_gc_task);
 196                 kfree(gc_th);
 197                 sbi->gc_thread = NULL;
 198         }
 199 out:
 200         return err;
 201 }
 202
 203 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 204 {
 205         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 206
 207         if (!gc_th)
 208                 return;
 209         kthread_stop(gc_th->f2fs_gc_task);
 210         wake_up_all(&gc_th->fggc_wq);
 211         kfree(gc_th);
 212         sbi->gc_thread = NULL;
 213 }
 214
 215 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 216 {
 217         int gc_mode;
 218
 219         if (gc_type == BG_GC) {
 220                 if (sbi->am.atgc_enabled)
 221                         gc_mode = GC_AT;
 222                 else
 223                         gc_mode = GC_CB;
 224         } else {
 225                 gc_mode = GC_GREEDY;
 226         }
 227
 228         switch (sbi->gc_mode) {
 229         case GC_IDLE_CB:
 230                 gc_mode = GC_CB;
 231                 break;
 232         case GC_IDLE_GREEDY:
 233         case GC_URGENT_HIGH:
 234                 gc_mode = GC_GREEDY;
 235                 break;
 236         case GC_IDLE_AT:
 237                 gc_mode = GC_AT;
 238                 break;
 239         }
 240
 241         return gc_mode;
 242 }
 243
 244 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 245                         int type, struct victim_sel_policy *p)
 246 {
 247         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 248
 249         if (p->alloc_mode == SSR) {
 250                 p->gc_mode = GC_GREEDY;
 251                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 252                 p->max_search = dirty_i->nr_dirty[type];
 253                 p->ofs_unit = 1;
 254         } else if (p->alloc_mode == AT_SSR) {
 255                 p->gc_mode = GC_GREEDY;
 256                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 257                 p->max_search = dirty_i->nr_dirty[type];
 258                 p->ofs_unit = 1;
 259         } else {
 260                 p->gc_mode = select_gc_type(sbi, gc_type);
 261                 p->ofs_unit = sbi->segs_per_sec;
 262                 if (__is_large_section(sbi)) {
 263                         p->dirty_bitmap = dirty_i->dirty_secmap;
 264                         p->max_search = count_bits(p->dirty_bitmap,
 265                                                 0, MAIN_SECS(sbi));
 266                 } else {
 267                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 268                         p->max_search = dirty_i->nr_dirty[DIRTY];
 269                 }
 270         }
 271
 272         /*
 273          * adjust candidates range, should select all dirty segments for
 274          * foreground GC and urgent GC cases.
 275          */
 276         if (gc_type != FG_GC &&
 277                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 278                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 279                         p->max_search > sbi->max_victim_search)
 280                 p->max_search = sbi->max_victim_search;
 281
 282         /* let's select beginning hot/small space first in no_heap mode*/
 283         if (f2fs_need_rand_seg(sbi))
 284                 p->offset = prandom_u32_max(MAIN_SECS(sbi) * sbi->segs_per_sec);
 285         else if (test_opt(sbi, NOHEAP) &&
 286                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 287                 p->offset = 0;
 288         else
 289                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 290 }
 291
 292 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 293                                 struct victim_sel_policy *p)
 294 {
 295         /* SSR allocates in a segment unit */
 296         if (p->alloc_mode == SSR)
 297                 return sbi->blocks_per_seg;
 298         else if (p->alloc_mode == AT_SSR)
 299                 return UINT_MAX;
 300
 301         /* LFS */
 302         if (p->gc_mode == GC_GREEDY)
 303                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 304         else if (p->gc_mode == GC_CB)
 305                 return UINT_MAX;
 306         else if (p->gc_mode == GC_AT)
 307                 return UINT_MAX;
 308         else /* No other gc_mode */
 309                 return 0;
 310 }
 311
 312 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 313 {
 314         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 315         unsigned int secno;
 316
 317         /*
 318          * If the gc_type is FG_GC, we can select victim segments
 319          * selected by background GC before.
 320          * Those segments guarantee they have small valid blocks.
 321          */
 322         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 323                 if (sec_usage_check(sbi, secno))
 324                         continue;
 325                 clear_bit(secno, dirty_i->victim_secmap);
 326                 return GET_SEG_FROM_SEC(sbi, secno);
 327         }
 328         return NULL_SEGNO;
 329 }
 330
 331 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 332 {
 333         struct sit_info *sit_i = SIT_I(sbi);
 334         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 335         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 336         unsigned long long mtime = 0;
 337         unsigned int vblocks;
 338         unsigned char age = 0;
 339         unsigned char u;
 340         unsigned int i;
 341         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 342
 343         for (i = 0; i < usable_segs_per_sec; i++)
 344                 mtime += get_seg_entry(sbi, start + i)->mtime;
 345         vblocks = get_valid_blocks(sbi, segno, true);
 346
 347         mtime = div_u64(mtime, usable_segs_per_sec);
 348         vblocks = div_u64(vblocks, usable_segs_per_sec);
 349
 350         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 351
 352         /* Handle if the system time has changed by the user */
 353         if (mtime < sit_i->min_mtime)
 354                 sit_i->min_mtime = mtime;
 355         if (mtime > sit_i->max_mtime)
 356                 sit_i->max_mtime = mtime;
 357         if (sit_i->max_mtime != sit_i->min_mtime)
 358                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 359                                 sit_i->max_mtime - sit_i->min_mtime);
 360
 361         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 362 }
 363
 364 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 365                         unsigned int segno, struct victim_sel_policy *p)
 366 {
 367         if (p->alloc_mode == SSR)
 368                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 369
 370         /* alloc_mode == LFS */
 371         if (p->gc_mode == GC_GREEDY)
 372                 return get_valid_blocks(sbi, segno, true);
 373         else if (p->gc_mode == GC_CB)
 374                 return get_cb_cost(sbi, segno);
 375
 376         f2fs_bug_on(sbi, 1);
 377         return 0;
 378 }
 379
 380 static unsigned int count_bits(const unsigned long *addr,
 381                                 unsigned int offset, unsigned int len)
 382 {
 383         unsigned int end = offset + len, sum = 0;
 384
 385         while (offset < end) {
 386                 if (test_bit(offset++, addr))
 387                         ++sum;
 388         }
 389         return sum;
 390 }
 391
 392 static bool f2fs_check_victim_tree(struct f2fs_sb_info *sbi,
 393                                 struct rb_root_cached *root)
 394 {
 395 #ifdef CONFIG_F2FS_CHECK_FS
 396         struct rb_node *cur = rb_first_cached(root), *next;
 397         struct victim_entry *cur_ve, *next_ve;
 398
 399         while (cur) {
 400                 next = rb_next(cur);
 401                 if (!next)
 402                         return true;
 403
 404                 cur_ve = rb_entry(cur, struct victim_entry, rb_node);
 405                 next_ve = rb_entry(next, struct victim_entry, rb_node);
 406
 407                 if (cur_ve->mtime > next_ve->mtime) {
 408                         f2fs_info(sbi, "broken victim_rbtree, "
 409                                 "cur_mtime(%llu) next_mtime(%llu)",
 410                                 cur_ve->mtime, next_ve->mtime);
 411                         return false;
 412                 }
 413                 cur = next;
 414         }
 415 #endif
 416         return true;
 417 }
 418
 419 static struct victim_entry *__lookup_victim_entry(struct f2fs_sb_info *sbi,
 420                                         unsigned long long mtime)
 421 {
 422         struct atgc_management *am = &sbi->am;
 423         struct rb_node *node = am->root.rb_root.rb_node;
 424         struct victim_entry *ve = NULL;
 425
 426         while (node) {
 427                 ve = rb_entry(node, struct victim_entry, rb_node);
 428
 429                 if (mtime < ve->mtime)
 430                         node = node->rb_left;
 431                 else
 432                         node = node->rb_right;
 433         }
 434         return ve;
 435 }
 436
 437 static struct victim_entry *__create_victim_entry(struct f2fs_sb_info *sbi,
 438                 unsigned long long mtime, unsigned int segno)
 439 {
 440         struct atgc_management *am = &sbi->am;
 441         struct victim_entry *ve;
 442
 443         ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS, true, NULL);
 444
 445         ve->mtime = mtime;
 446         ve->segno = segno;
 447
 448         list_add_tail(&ve->list, &am->victim_list);
 449         am->victim_count++;
 450
 451         return ve;
 452 }
 453
 454 static void __insert_victim_entry(struct f2fs_sb_info *sbi,
 455                                 unsigned long long mtime, unsigned int segno)
 456 {
 457         struct atgc_management *am = &sbi->am;
 458         struct rb_root_cached *root = &am->root;
 459         struct rb_node **p = &root->rb_root.rb_node;
 460         struct rb_node *parent = NULL;
 461         struct victim_entry *ve;
 462         bool left_most = true;
 463
 464         /* look up rb tree to find parent node */
 465         while (*p) {
 466                 parent = *p;
 467                 ve = rb_entry(parent, struct victim_entry, rb_node);
 468
 469                 if (mtime < ve->mtime) {
 470                         p = &(*p)->rb_left;
 471                 } else {
 472                         p = &(*p)->rb_right;
 473                         left_most = false;
 474                 }
 475         }
 476
 477         ve = __create_victim_entry(sbi, mtime, segno);
 478
 479         rb_link_node(&ve->rb_node, parent, p);
 480         rb_insert_color_cached(&ve->rb_node, root, left_most);
 481 }
 482
 483 static void add_victim_entry(struct f2fs_sb_info *sbi,
 484                                 struct victim_sel_policy *p, unsigned int segno)
 485 {
 486         struct sit_info *sit_i = SIT_I(sbi);
 487         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 488         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 489         unsigned long long mtime = 0;
 490         unsigned int i;
 491
 492         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 493                 if (p->gc_mode == GC_AT &&
 494                         get_valid_blocks(sbi, segno, true) == 0)
 495                         return;
 496         }
 497
 498         for (i = 0; i < sbi->segs_per_sec; i++)
 499                 mtime += get_seg_entry(sbi, start + i)->mtime;
 500         mtime = div_u64(mtime, sbi->segs_per_sec);
 501
 502         /* Handle if the system time has changed by the user */
 503         if (mtime < sit_i->min_mtime)
 504                 sit_i->min_mtime = mtime;
 505         if (mtime > sit_i->max_mtime)
 506                 sit_i->max_mtime = mtime;
 507         if (mtime < sit_i->dirty_min_mtime)
 508                 sit_i->dirty_min_mtime = mtime;
 509         if (mtime > sit_i->dirty_max_mtime)
 510                 sit_i->dirty_max_mtime = mtime;
 511
 512         /* don't choose young section as candidate */
 513         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 514                 return;
 515
 516         __insert_victim_entry(sbi, mtime, segno);
 517 }
 518
 519 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 520                                                 struct victim_sel_policy *p)
 521 {
 522         struct sit_info *sit_i = SIT_I(sbi);
 523         struct atgc_management *am = &sbi->am;
 524         struct rb_root_cached *root = &am->root;
 525         struct rb_node *node;
 526         struct victim_entry *ve;
 527         unsigned long long total_time;
 528         unsigned long long age, u, accu;
 529         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 530         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 531         unsigned int sec_blocks = CAP_BLKS_PER_SEC(sbi);
 532         unsigned int vblocks;
 533         unsigned int dirty_threshold = max(am->max_candidate_count,
 534                                         am->candidate_ratio *
 535                                         am->victim_count / 100);
 536         unsigned int age_weight = am->age_weight;
 537         unsigned int cost;
 538         unsigned int iter = 0;
 539
 540         if (max_mtime < min_mtime)
 541                 return;
 542
 543         max_mtime += 1;
 544         total_time = max_mtime - min_mtime;
 545
 546         accu = div64_u64(ULLONG_MAX, total_time);
 547         accu = min_t(unsigned long long, div_u64(accu, 100),
 548                                         DEFAULT_ACCURACY_CLASS);
 549
 550         node = rb_first_cached(root);
 551 next:
 552         ve = rb_entry_safe(node, struct victim_entry, rb_node);
 553         if (!ve)
 554                 return;
 555
 556         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 557                 goto skip;
 558
 559         /* age = 10000 * x% * 60 */
 560         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 561                                                                 age_weight;
 562
 563         vblocks = get_valid_blocks(sbi, ve->segno, true);
 564         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 565
 566         /* u = 10000 * x% * 40 */
 567         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 568                                                         (100 - age_weight);
 569
 570         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 571
 572         cost = UINT_MAX - (age + u);
 573         iter++;
 574
 575         if (cost < p->min_cost ||
 576                         (cost == p->min_cost && age > p->oldest_age)) {
 577                 p->min_cost = cost;
 578                 p->oldest_age = age;
 579                 p->min_segno = ve->segno;
 580         }
 581 skip:
 582         if (iter < dirty_threshold) {
 583                 node = rb_next(node);
 584                 goto next;
 585         }
 586 }
 587
 588 /*
 589  * select candidates around source section in range of
 590  * [target - dirty_threshold, target + dirty_threshold]
 591  */
 592 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 593                                                 struct victim_sel_policy *p)
 594 {
 595         struct sit_info *sit_i = SIT_I(sbi);
 596         struct atgc_management *am = &sbi->am;
 597         struct victim_entry *ve;
 598         unsigned long long age;
 599         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 600         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 601         unsigned int seg_blocks = sbi->blocks_per_seg;
 602         unsigned int vblocks;
 603         unsigned int dirty_threshold = max(am->max_candidate_count,
 604                                         am->candidate_ratio *
 605                                         am->victim_count / 100);
 606         unsigned int cost, iter;
 607         int stage = 0;
 608
 609         if (max_mtime < min_mtime)
 610                 return;
 611         max_mtime += 1;
 612 next_stage:
 613         iter = 0;
 614         ve = __lookup_victim_entry(sbi, p->age);
 615 next_node:
 616         if (!ve) {
 617                 if (stage++ == 0)
 618                         goto next_stage;
 619                 return;
 620         }
 621
 622         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 623                 goto skip_node;
 624
 625         age = max_mtime - ve->mtime;
 626
 627         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 628         f2fs_bug_on(sbi, !vblocks);
 629
 630         /* rare case */
 631         if (vblocks == seg_blocks)
 632                 goto skip_node;
 633
 634         iter++;
 635
 636         age = max_mtime - abs(p->age - age);
 637         cost = UINT_MAX - vblocks;
 638
 639         if (cost < p->min_cost ||
 640                         (cost == p->min_cost && age > p->oldest_age)) {
 641                 p->min_cost = cost;
 642                 p->oldest_age = age;
 643                 p->min_segno = ve->segno;
 644         }
 645 skip_node:
 646         if (iter < dirty_threshold) {
 647                 ve = rb_entry(stage == 0 ? rb_prev(&ve->rb_node) :
 648                                         rb_next(&ve->rb_node),
 649                                         struct victim_entry, rb_node);
 650                 goto next_node;
 651         }
 652
 653         if (stage++ == 0)
 654                 goto next_stage;
 655 }
 656
 657 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 658                                                 struct victim_sel_policy *p)
 659 {
 660         f2fs_bug_on(sbi, !f2fs_check_victim_tree(sbi, &sbi->am.root));
 661
 662         if (p->gc_mode == GC_AT)
 663                 atgc_lookup_victim(sbi, p);
 664         else if (p->alloc_mode == AT_SSR)
 665                 atssr_lookup_victim(sbi, p);
 666         else
 667                 f2fs_bug_on(sbi, 1);
 668 }
 669
 670 static void release_victim_entry(struct f2fs_sb_info *sbi)
 671 {
 672         struct atgc_management *am = &sbi->am;
 673         struct victim_entry *ve, *tmp;
 674
 675         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 676                 list_del(&ve->list);
 677                 kmem_cache_free(victim_entry_slab, ve);
 678                 am->victim_count--;
 679         }
 680
 681         am->root = RB_ROOT_CACHED;
 682
 683         f2fs_bug_on(sbi, am->victim_count);
 684         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 685 }
 686
 687 static bool f2fs_pin_section(struct f2fs_sb_info *sbi, unsigned int segno)
 688 {
 689         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 690         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 691
 692         if (!dirty_i->enable_pin_section)
 693                 return false;
 694         if (!test_and_set_bit(secno, dirty_i->pinned_secmap))
 695                 dirty_i->pinned_secmap_cnt++;
 696         return true;
 697 }
 698
 699 static bool f2fs_pinned_section_exists(struct dirty_seglist_info *dirty_i)
 700 {
 701         return dirty_i->pinned_secmap_cnt;
 702 }
 703
 704 static bool f2fs_section_is_pinned(struct dirty_seglist_info *dirty_i,
 705                                                 unsigned int secno)
 706 {
 707         return dirty_i->enable_pin_section &&
 708                 f2fs_pinned_section_exists(dirty_i) &&
 709                 test_bit(secno, dirty_i->pinned_secmap);
 710 }
 711
 712 static void f2fs_unpin_all_sections(struct f2fs_sb_info *sbi, bool enable)
 713 {
 714         unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
 715
 716         if (f2fs_pinned_section_exists(DIRTY_I(sbi))) {
 717                 memset(DIRTY_I(sbi)->pinned_secmap, 0, bitmap_size);
 718                 DIRTY_I(sbi)->pinned_secmap_cnt = 0;
 719         }
 720         DIRTY_I(sbi)->enable_pin_section = enable;
 721 }
 722
 723 static int f2fs_gc_pinned_control(struct inode *inode, int gc_type,
 724                                                         unsigned int segno)
 725 {
 726         if (!f2fs_is_pinned_file(inode))
 727                 return 0;
 728         if (gc_type != FG_GC)
 729                 return -EBUSY;
 730         if (!f2fs_pin_section(F2FS_I_SB(inode), segno))
 731                 f2fs_pin_file_control(inode, true);
 732         return -EAGAIN;
 733 }
 734
 735 /*
 736  * This function is called from two paths.
 737  * One is garbage collection and the other is SSR segment selection.
 738  * When it is called during GC, it just gets a victim segment
 739  * and it does not remove it from dirty seglist.
 740  * When it is called from SSR segment selection, it finds a segment
 741  * which has minimum valid blocks and removes it from dirty seglist.
 742  */
 743 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 744                         unsigned int *result, int gc_type, int type,
 745                         char alloc_mode, unsigned long long age)
 746 {
 747         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 748         struct sit_info *sm = SIT_I(sbi);
 749         struct victim_sel_policy p;
 750         unsigned int secno, last_victim;
 751         unsigned int last_segment;
 752         unsigned int nsearched;
 753         bool is_atgc;
 754         int ret = 0;
 755
 756         mutex_lock(&dirty_i->seglist_lock);
 757         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 758
 759         p.alloc_mode = alloc_mode;
 760         p.age = age;
 761         p.age_threshold = sbi->am.age_threshold;
 762
 763 retry:
 764         select_policy(sbi, gc_type, type, &p);
 765         p.min_segno = NULL_SEGNO;
 766         p.oldest_age = 0;
 767         p.min_cost = get_max_cost(sbi, &p);
 768
 769         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 770         nsearched = 0;
 771
 772         if (is_atgc)
 773                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 774
 775         if (*result != NULL_SEGNO) {
 776                 if (!get_valid_blocks(sbi, *result, false)) {
 777                         ret = -ENODATA;
 778                         goto out;
 779                 }
 780
 781                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 782                         ret = -EBUSY;
 783                 else
 784                         p.min_segno = *result;
 785                 goto out;
 786         }
 787
 788         ret = -ENODATA;
 789         if (p.max_search == 0)
 790                 goto out;
 791
 792         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 793                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 794                         p.min_segno = sbi->next_victim_seg[BG_GC];
 795                         *result = p.min_segno;
 796                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 797                         goto got_result;
 798                 }
 799                 if (gc_type == FG_GC &&
 800                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 801                         p.min_segno = sbi->next_victim_seg[FG_GC];
 802                         *result = p.min_segno;
 803                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 804                         goto got_result;
 805                 }
 806         }
 807
 808         last_victim = sm->last_victim[p.gc_mode];
 809         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 810                 p.min_segno = check_bg_victims(sbi);
 811                 if (p.min_segno != NULL_SEGNO)
 812                         goto got_it;
 813         }
 814
 815         while (1) {
 816                 unsigned long cost, *dirty_bitmap;
 817                 unsigned int unit_no, segno;
 818
 819                 dirty_bitmap = p.dirty_bitmap;
 820                 unit_no = find_next_bit(dirty_bitmap,
 821                                 last_segment / p.ofs_unit,
 822                                 p.offset / p.ofs_unit);
 823                 segno = unit_no * p.ofs_unit;
 824                 if (segno >= last_segment) {
 825                         if (sm->last_victim[p.gc_mode]) {
 826                                 last_segment =
 827                                         sm->last_victim[p.gc_mode];
 828                                 sm->last_victim[p.gc_mode] = 0;
 829                                 p.offset = 0;
 830                                 continue;
 831                         }
 832                         break;
 833                 }
 834
 835                 p.offset = segno + p.ofs_unit;
 836                 nsearched++;
 837
 838 #ifdef CONFIG_F2FS_CHECK_FS
 839                 /*
 840                  * skip selecting the invalid segno (that is failed due to block
 841                  * validity check failure during GC) to avoid endless GC loop in
 842                  * such cases.
 843                  */
 844                 if (test_bit(segno, sm->invalid_segmap))
 845                         goto next;
 846 #endif
 847
 848                 secno = GET_SEC_FROM_SEG(sbi, segno);
 849
 850                 if (sec_usage_check(sbi, secno))
 851                         goto next;
 852
 853                 /* Don't touch checkpointed data */
 854                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 855                         if (p.alloc_mode == LFS) {
 856                                 /*
 857                                  * LFS is set to find source section during GC.
 858                                  * The victim should have no checkpointed data.
 859                                  */
 860                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 861                                         goto next;
 862                         } else {
 863                                 /*
 864                                  * SSR | AT_SSR are set to find target segment
 865                                  * for writes which can be full by checkpointed
 866                                  * and newly written blocks.
 867                                  */
 868                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 869                                         goto next;
 870                         }
 871                 }
 872
 873                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 874                         goto next;
 875
 876                 if (gc_type == FG_GC && f2fs_section_is_pinned(dirty_i, secno))
 877                         goto next;
 878
 879                 if (is_atgc) {
 880                         add_victim_entry(sbi, &p, segno);
 881                         goto next;
 882                 }
 883
 884                 cost = get_gc_cost(sbi, segno, &p);
 885
 886                 if (p.min_cost > cost) {
 887                         p.min_segno = segno;
 888                         p.min_cost = cost;
 889                 }
 890 next:
 891                 if (nsearched >= p.max_search) {
 892                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 893                                 sm->last_victim[p.gc_mode] =
 894                                         last_victim + p.ofs_unit;
 895                         else
 896                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 897                         sm->last_victim[p.gc_mode] %=
 898                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 899                         break;
 900                 }
 901         }
 902
 903         /* get victim for GC_AT/AT_SSR */
 904         if (is_atgc) {
 905                 lookup_victim_by_age(sbi, &p);
 906                 release_victim_entry(sbi);
 907         }
 908
 909         if (is_atgc && p.min_segno == NULL_SEGNO &&
 910                         sm->elapsed_time < p.age_threshold) {
 911                 p.age_threshold = 0;
 912                 goto retry;
 913         }
 914
 915         if (p.min_segno != NULL_SEGNO) {
 916 got_it:
 917                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 918 got_result:
 919                 if (p.alloc_mode == LFS) {
 920                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 921                         if (gc_type == FG_GC)
 922                                 sbi->cur_victim_sec = secno;
 923                         else
 924                                 set_bit(secno, dirty_i->victim_secmap);
 925                 }
 926                 ret = 0;
 927
 928         }
 929 out:
 930         if (p.min_segno != NULL_SEGNO)
 931                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 932                                 sbi->cur_victim_sec,
 933                                 prefree_segments(sbi), free_segments(sbi));
 934         mutex_unlock(&dirty_i->seglist_lock);
 935
 936         return ret;
 937 }
 938
 939 static const struct victim_selection default_v_ops = {
 940         .get_victim = get_victim_by_default,
 941 };
 942
 943 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 944 {
 945         struct inode_entry *ie;
 946
 947         ie = radix_tree_lookup(&gc_list->iroot, ino);
 948         if (ie)
 949                 return ie->inode;
 950         return NULL;
 951 }
 952
 953 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 954 {
 955         struct inode_entry *new_ie;
 956
 957         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 958                 iput(inode);
 959                 return;
 960         }
 961         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 962                                         GFP_NOFS, true, NULL);
 963         new_ie->inode = inode;
 964
 965         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 966         list_add_tail(&new_ie->list, &gc_list->ilist);
 967 }
 968
 969 static void put_gc_inode(struct gc_inode_list *gc_list)
 970 {
 971         struct inode_entry *ie, *next_ie;
 972
 973         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 974                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 975                 iput(ie->inode);
 976                 list_del(&ie->list);
 977                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 978         }
 979 }
 980
 981 static int check_valid_map(struct f2fs_sb_info *sbi,
 982                                 unsigned int segno, int offset)
 983 {
 984         struct sit_info *sit_i = SIT_I(sbi);
 985         struct seg_entry *sentry;
 986         int ret;
 987
 988         down_read(&sit_i->sentry_lock);
 989         sentry = get_seg_entry(sbi, segno);
 990         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 991         up_read(&sit_i->sentry_lock);
 992         return ret;
 993 }
 994
 995 /*
 996  * This function compares node address got in summary with that in NAT.
 997  * On validity, copy that node with cold status, otherwise (invalid node)
 998  * ignore that.
 999  */
1000 static int gc_node_segment(struct f2fs_sb_info *sbi,
1001                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
1002 {
1003         struct f2fs_summary *entry;
1004         block_t start_addr;
1005         int off;
1006         int phase = 0;
1007         bool fggc = (gc_type == FG_GC);
1008         int submitted = 0;
1009         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1010
1011         start_addr = START_BLOCK(sbi, segno);
1012
1013 next_step:
1014         entry = sum;
1015
1016         if (fggc && phase == 2)
1017                 atomic_inc(&sbi->wb_sync_req[NODE]);
1018
1019         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1020                 nid_t nid = le32_to_cpu(entry->nid);
1021                 struct page *node_page;
1022                 struct node_info ni;
1023                 int err;
1024
1025                 /* stop BG_GC if there is not enough free sections. */
1026                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
1027                         return submitted;
1028
1029                 if (check_valid_map(sbi, segno, off) == 0)
1030                         continue;
1031
1032                 if (phase == 0) {
1033                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1034                                                         META_NAT, true);
1035                         continue;
1036                 }
1037
1038                 if (phase == 1) {
1039                         f2fs_ra_node_page(sbi, nid);
1040                         continue;
1041                 }
1042
1043                 /* phase == 2 */
1044                 node_page = f2fs_get_node_page(sbi, nid);
1045                 if (IS_ERR(node_page))
1046                         continue;
1047
1048                 /* block may become invalid during f2fs_get_node_page */
1049                 if (check_valid_map(sbi, segno, off) == 0) {
1050                         f2fs_put_page(node_page, 1);
1051                         continue;
1052                 }
1053
1054                 if (f2fs_get_node_info(sbi, nid, &ni, false)) {
1055                         f2fs_put_page(node_page, 1);
1056                         continue;
1057                 }
1058
1059                 if (ni.blk_addr != start_addr + off) {
1060                         f2fs_put_page(node_page, 1);
1061                         continue;
1062                 }
1063
1064                 err = f2fs_move_node_page(node_page, gc_type);
1065                 if (!err && gc_type == FG_GC)
1066                         submitted++;
1067                 stat_inc_node_blk_count(sbi, 1, gc_type);
1068         }
1069
1070         if (++phase < 3)
1071                 goto next_step;
1072
1073         if (fggc)
1074                 atomic_dec(&sbi->wb_sync_req[NODE]);
1075         return submitted;
1076 }
1077
1078 /*
1079  * Calculate start block index indicating the given node offset.
1080  * Be careful, caller should give this node offset only indicating direct node
1081  * blocks. If any node offsets, which point the other types of node blocks such
1082  * as indirect or double indirect node blocks, are given, it must be a caller's
1083  * bug.
1084  */
1085 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
1086 {
1087         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
1088         unsigned int bidx;
1089
1090         if (node_ofs == 0)
1091                 return 0;
1092
1093         if (node_ofs <= 2) {
1094                 bidx = node_ofs - 1;
1095         } else if (node_ofs <= indirect_blks) {
1096                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
1097
1098                 bidx = node_ofs - 2 - dec;
1099         } else {
1100                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
1101
1102                 bidx = node_ofs - 5 - dec;
1103         }
1104         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1105 }
1106
1107 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1108                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1109 {
1110         struct page *node_page;
1111         nid_t nid;
1112         unsigned int ofs_in_node, max_addrs, base;
1113         block_t source_blkaddr;
1114
1115         nid = le32_to_cpu(sum->nid);
1116         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1117
1118         node_page = f2fs_get_node_page(sbi, nid);
1119         if (IS_ERR(node_page))
1120                 return false;
1121
1122         if (f2fs_get_node_info(sbi, nid, dni, false)) {
1123                 f2fs_put_page(node_page, 1);
1124                 return false;
1125         }
1126
1127         if (sum->version != dni->version) {
1128                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1129                           __func__);
1130                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1131         }
1132
1133         if (f2fs_check_nid_range(sbi, dni->ino)) {
1134                 f2fs_put_page(node_page, 1);
1135                 return false;
1136         }
1137
1138         if (IS_INODE(node_page)) {
1139                 base = offset_in_addr(F2FS_INODE(node_page));
1140                 max_addrs = DEF_ADDRS_PER_INODE;
1141         } else {
1142                 base = 0;
1143                 max_addrs = DEF_ADDRS_PER_BLOCK;
1144         }
1145
1146         if (base + ofs_in_node >= max_addrs) {
1147                 f2fs_err(sbi, "Inconsistent blkaddr offset: base:%u, ofs_in_node:%u, max:%u, ino:%u, nid:%u",
1148                         base, ofs_in_node, max_addrs, dni->ino, dni->nid);
1149                 f2fs_put_page(node_page, 1);
1150                 return false;
1151         }
1152
1153         *nofs = ofs_of_node(node_page);
1154         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1155         f2fs_put_page(node_page, 1);
1156
1157         if (source_blkaddr != blkaddr) {
1158 #ifdef CONFIG_F2FS_CHECK_FS
1159                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1160                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1161
1162                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1163                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1164                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1165                                          blkaddr, source_blkaddr, segno);
1166                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1167                         }
1168                 }
1169 #endif
1170                 return false;
1171         }
1172         return true;
1173 }
1174
1175 static int ra_data_block(struct inode *inode, pgoff_t index)
1176 {
1177         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1178         struct address_space *mapping = inode->i_mapping;
1179         struct dnode_of_data dn;
1180         struct page *page;
1181         struct extent_info ei = {0, };
1182         struct f2fs_io_info fio = {
1183                 .sbi = sbi,
1184                 .ino = inode->i_ino,
1185                 .type = DATA,
1186                 .temp = COLD,
1187                 .op = REQ_OP_READ,
1188                 .op_flags = 0,
1189                 .encrypted_page = NULL,
1190                 .in_list = 0,
1191                 .retry = 0,
1192         };
1193         int err;
1194
1195         page = f2fs_grab_cache_page(mapping, index, true);
1196         if (!page)
1197                 return -ENOMEM;
1198
1199         if (f2fs_lookup_read_extent_cache(inode, index, &ei)) {
1200                 dn.data_blkaddr = ei.blk + index - ei.fofs;
1201                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1202                                                 DATA_GENERIC_ENHANCE_READ))) {
1203                         err = -EFSCORRUPTED;
1204                         f2fs_handle_error(sbi, ERROR_INVALID_BLKADDR);
1205                         goto put_page;
1206                 }
1207                 goto got_it;
1208         }
1209
1210         set_new_dnode(&dn, inode, NULL, NULL, 0);
1211         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1212         if (err)
1213                 goto put_page;
1214         f2fs_put_dnode(&dn);
1215
1216         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1217                 err = -ENOENT;
1218                 goto put_page;
1219         }
1220         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1221                                                 DATA_GENERIC_ENHANCE))) {
1222                 err = -EFSCORRUPTED;
1223                 f2fs_handle_error(sbi, ERROR_INVALID_BLKADDR);
1224                 goto put_page;
1225         }
1226 got_it:
1227         /* read page */
1228         fio.page = page;
1229         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1230
1231         /*
1232          * don't cache encrypted data into meta inode until previous dirty
1233          * data were writebacked to avoid racing between GC and flush.
1234          */
1235         f2fs_wait_on_page_writeback(page, DATA, true, true);
1236
1237         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1238
1239         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1240                                         dn.data_blkaddr,
1241                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1242         if (!fio.encrypted_page) {
1243                 err = -ENOMEM;
1244                 goto put_page;
1245         }
1246
1247         err = f2fs_submit_page_bio(&fio);
1248         if (err)
1249                 goto put_encrypted_page;
1250         f2fs_put_page(fio.encrypted_page, 0);
1251         f2fs_put_page(page, 1);
1252
1253         f2fs_update_iostat(sbi, inode, FS_DATA_READ_IO, F2FS_BLKSIZE);
1254         f2fs_update_iostat(sbi, NULL, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1255
1256         return 0;
1257 put_encrypted_page:
1258         f2fs_put_page(fio.encrypted_page, 1);
1259 put_page:
1260         f2fs_put_page(page, 1);
1261         return err;
1262 }
1263
1264 /*
1265  * Move data block via META_MAPPING while keeping locked data page.
1266  * This can be used to move blocks, aka LBAs, directly on disk.
1267  */
1268 static int move_data_block(struct inode *inode, block_t bidx,
1269                                 int gc_type, unsigned int segno, int off)
1270 {
1271         struct f2fs_io_info fio = {
1272                 .sbi = F2FS_I_SB(inode),
1273                 .ino = inode->i_ino,
1274                 .type = DATA,
1275                 .temp = COLD,
1276                 .op = REQ_OP_READ,
1277                 .op_flags = 0,
1278                 .encrypted_page = NULL,
1279                 .in_list = 0,
1280                 .retry = 0,
1281         };
1282         struct dnode_of_data dn;
1283         struct f2fs_summary sum;
1284         struct node_info ni;
1285         struct page *page, *mpage;
1286         block_t newaddr;
1287         int err = 0;
1288         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1289         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1290                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1291                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1292
1293         /* do not read out */
1294         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1295         if (!page)
1296                 return -ENOMEM;
1297
1298         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1299                 err = -ENOENT;
1300                 goto out;
1301         }
1302
1303         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1304         if (err)
1305                 goto out;
1306
1307         set_new_dnode(&dn, inode, NULL, NULL, 0);
1308         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1309         if (err)
1310                 goto out;
1311
1312         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1313                 ClearPageUptodate(page);
1314                 err = -ENOENT;
1315                 goto put_out;
1316         }
1317
1318         /*
1319          * don't cache encrypted data into meta inode until previous dirty
1320          * data were writebacked to avoid racing between GC and flush.
1321          */
1322         f2fs_wait_on_page_writeback(page, DATA, true, true);
1323
1324         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1325
1326         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni, false);
1327         if (err)
1328                 goto put_out;
1329
1330         /* read page */
1331         fio.page = page;
1332         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1333
1334         if (lfs_mode)
1335                 f2fs_down_write(&fio.sbi->io_order_lock);
1336
1337         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1338                                         fio.old_blkaddr, false);
1339         if (!mpage) {
1340                 err = -ENOMEM;
1341                 goto up_out;
1342         }
1343
1344         fio.encrypted_page = mpage;
1345
1346         /* read source block in mpage */
1347         if (!PageUptodate(mpage)) {
1348                 err = f2fs_submit_page_bio(&fio);
1349                 if (err) {
1350                         f2fs_put_page(mpage, 1);
1351                         goto up_out;
1352                 }
1353
1354                 f2fs_update_iostat(fio.sbi, inode, FS_DATA_READ_IO,
1355                                                         F2FS_BLKSIZE);
1356                 f2fs_update_iostat(fio.sbi, NULL, FS_GDATA_READ_IO,
1357                                                         F2FS_BLKSIZE);
1358
1359                 lock_page(mpage);
1360                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1361                                                 !PageUptodate(mpage))) {
1362                         err = -EIO;
1363                         f2fs_put_page(mpage, 1);
1364                         goto up_out;
1365                 }
1366         }
1367
1368         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1369
1370         /* allocate block address */
1371         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1372                                 &sum, type, NULL);
1373
1374         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1375                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1376         if (!fio.encrypted_page) {
1377                 err = -ENOMEM;
1378                 f2fs_put_page(mpage, 1);
1379                 goto recover_block;
1380         }
1381
1382         /* write target block */
1383         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1384         memcpy(page_address(fio.encrypted_page),
1385                                 page_address(mpage), PAGE_SIZE);
1386         f2fs_put_page(mpage, 1);
1387         invalidate_mapping_pages(META_MAPPING(fio.sbi),
1388                                 fio.old_blkaddr, fio.old_blkaddr);
1389         f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1390
1391         set_page_dirty(fio.encrypted_page);
1392         if (clear_page_dirty_for_io(fio.encrypted_page))
1393                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1394
1395         set_page_writeback(fio.encrypted_page);
1396         ClearPageError(page);
1397
1398         fio.op = REQ_OP_WRITE;
1399         fio.op_flags = REQ_SYNC;
1400         fio.new_blkaddr = newaddr;
1401         f2fs_submit_page_write(&fio);
1402         if (fio.retry) {
1403                 err = -EAGAIN;
1404                 if (PageWriteback(fio.encrypted_page))
1405                         end_page_writeback(fio.encrypted_page);
1406                 goto put_page_out;
1407         }
1408
1409         f2fs_update_iostat(fio.sbi, NULL, FS_GC_DATA_IO, F2FS_BLKSIZE);
1410
1411         f2fs_update_data_blkaddr(&dn, newaddr);
1412         set_inode_flag(inode, FI_APPEND_WRITE);
1413 put_page_out:
1414         f2fs_put_page(fio.encrypted_page, 1);
1415 recover_block:
1416         if (err)
1417                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1418                                                         true, true, true);
1419 up_out:
1420         if (lfs_mode)
1421                 f2fs_up_write(&fio.sbi->io_order_lock);
1422 put_out:
1423         f2fs_put_dnode(&dn);
1424 out:
1425         f2fs_put_page(page, 1);
1426         return err;
1427 }
1428
1429 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1430                                                         unsigned int segno, int off)
1431 {
1432         struct page *page;
1433         int err = 0;
1434
1435         page = f2fs_get_lock_data_page(inode, bidx, true);
1436         if (IS_ERR(page))
1437                 return PTR_ERR(page);
1438
1439         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1440                 err = -ENOENT;
1441                 goto out;
1442         }
1443
1444         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1445         if (err)
1446                 goto out;
1447
1448         if (gc_type == BG_GC) {
1449                 if (PageWriteback(page)) {
1450                         err = -EAGAIN;
1451                         goto out;
1452                 }
1453                 set_page_dirty(page);
1454                 set_page_private_gcing(page);
1455         } else {
1456                 struct f2fs_io_info fio = {
1457                         .sbi = F2FS_I_SB(inode),
1458                         .ino = inode->i_ino,
1459                         .type = DATA,
1460                         .temp = COLD,
1461                         .op = REQ_OP_WRITE,
1462                         .op_flags = REQ_SYNC,
1463                         .old_blkaddr = NULL_ADDR,
1464                         .page = page,
1465                         .encrypted_page = NULL,
1466                         .need_lock = LOCK_REQ,
1467                         .io_type = FS_GC_DATA_IO,
1468                 };
1469                 bool is_dirty = PageDirty(page);
1470
1471 retry:
1472                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1473
1474                 set_page_dirty(page);
1475                 if (clear_page_dirty_for_io(page)) {
1476                         inode_dec_dirty_pages(inode);
1477                         f2fs_remove_dirty_inode(inode);
1478                 }
1479
1480                 set_page_private_gcing(page);
1481
1482                 err = f2fs_do_write_data_page(&fio);
1483                 if (err) {
1484                         clear_page_private_gcing(page);
1485                         if (err == -ENOMEM) {
1486                                 memalloc_retry_wait(GFP_NOFS);
1487                                 goto retry;
1488                         }
1489                         if (is_dirty)
1490                                 set_page_dirty(page);
1491                 }
1492         }
1493 out:
1494         f2fs_put_page(page, 1);
1495         return err;
1496 }
1497
1498 /*
1499  * This function tries to get parent node of victim data block, and identifies
1500  * data block validity. If the block is valid, copy that with cold status and
1501  * modify parent node.
1502  * If the parent node is not valid or the data block address is different,
1503  * the victim data block is ignored.
1504  */
1505 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1506                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1507                 bool force_migrate)
1508 {
1509         struct super_block *sb = sbi->sb;
1510         struct f2fs_summary *entry;
1511         block_t start_addr;
1512         int off;
1513         int phase = 0;
1514         int submitted = 0;
1515         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1516
1517         start_addr = START_BLOCK(sbi, segno);
1518
1519 next_step:
1520         entry = sum;
1521
1522         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1523                 struct page *data_page;
1524                 struct inode *inode;
1525                 struct node_info dni; /* dnode info for the data */
1526                 unsigned int ofs_in_node, nofs;
1527                 block_t start_bidx;
1528                 nid_t nid = le32_to_cpu(entry->nid);
1529
1530                 /*
1531                  * stop BG_GC if there is not enough free sections.
1532                  * Or, stop GC if the segment becomes fully valid caused by
1533                  * race condition along with SSR block allocation.
1534                  */
1535                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1536                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1537                                                         CAP_BLKS_PER_SEC(sbi)))
1538                         return submitted;
1539
1540                 if (check_valid_map(sbi, segno, off) == 0)
1541                         continue;
1542
1543                 if (phase == 0) {
1544                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1545                                                         META_NAT, true);
1546                         continue;
1547                 }
1548
1549                 if (phase == 1) {
1550                         f2fs_ra_node_page(sbi, nid);
1551                         continue;
1552                 }
1553
1554                 /* Get an inode by ino with checking validity */
1555                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1556                         continue;
1557
1558                 if (phase == 2) {
1559                         f2fs_ra_node_page(sbi, dni.ino);
1560                         continue;
1561                 }
1562
1563                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1564
1565                 if (phase == 3) {
1566                         int err;
1567
1568                         inode = f2fs_iget(sb, dni.ino);
1569                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1570                                         special_file(inode->i_mode))
1571                                 continue;
1572
1573                         err = f2fs_gc_pinned_control(inode, gc_type, segno);
1574                         if (err == -EAGAIN) {
1575                                 iput(inode);
1576                                 return submitted;
1577                         }
1578
1579                         if (!f2fs_down_write_trylock(
1580                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1581                                 iput(inode);
1582                                 sbi->skipped_gc_rwsem++;
1583                                 continue;
1584                         }
1585
1586                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1587                                                                 ofs_in_node;
1588
1589                         if (f2fs_post_read_required(inode)) {
1590                                 int err = ra_data_block(inode, start_bidx);
1591
1592                                 f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1593                                 if (err) {
1594                                         iput(inode);
1595                                         continue;
1596                                 }
1597                                 add_gc_inode(gc_list, inode);
1598                                 continue;
1599                         }
1600
1601                         data_page = f2fs_get_read_data_page(inode, start_bidx,
1602                                                         REQ_RAHEAD, true, NULL);
1603                         f2fs_up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1604                         if (IS_ERR(data_page)) {
1605                                 iput(inode);
1606                                 continue;
1607                         }
1608
1609                         f2fs_put_page(data_page, 0);
1610                         add_gc_inode(gc_list, inode);
1611                         continue;
1612                 }
1613
1614                 /* phase 4 */
1615                 inode = find_gc_inode(gc_list, dni.ino);
1616                 if (inode) {
1617                         struct f2fs_inode_info *fi = F2FS_I(inode);
1618                         bool locked = false;
1619                         int err;
1620
1621                         if (S_ISREG(inode->i_mode)) {
1622                                 if (!f2fs_down_write_trylock(&fi->i_gc_rwsem[READ])) {
1623                                         sbi->skipped_gc_rwsem++;
1624                                         continue;
1625                                 }
1626                                 if (!f2fs_down_write_trylock(
1627                                                 &fi->i_gc_rwsem[WRITE])) {
1628                                         sbi->skipped_gc_rwsem++;
1629                                         f2fs_up_write(&fi->i_gc_rwsem[READ]);
1630                                         continue;
1631                                 }
1632                                 locked = true;
1633
1634                                 /* wait for all inflight aio data */
1635                                 inode_dio_wait(inode);
1636                         }
1637
1638                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1639                                                                 + ofs_in_node;
1640                         if (f2fs_post_read_required(inode))
1641                                 err = move_data_block(inode, start_bidx,
1642                                                         gc_type, segno, off);
1643                         else
1644                                 err = move_data_page(inode, start_bidx, gc_type,
1645                                                                 segno, off);
1646
1647                         if (!err && (gc_type == FG_GC ||
1648                                         f2fs_post_read_required(inode)))
1649                                 submitted++;
1650
1651                         if (locked) {
1652                                 f2fs_up_write(&fi->i_gc_rwsem[WRITE]);
1653                                 f2fs_up_write(&fi->i_gc_rwsem[READ]);
1654                         }
1655
1656                         stat_inc_data_blk_count(sbi, 1, gc_type);
1657                 }
1658         }
1659
1660         if (++phase < 5)
1661                 goto next_step;
1662
1663         return submitted;
1664 }
1665
1666 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1667                         int gc_type)
1668 {
1669         struct sit_info *sit_i = SIT_I(sbi);
1670         int ret;
1671
1672         down_write(&sit_i->sentry_lock);
1673         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1674                                               NO_CHECK_TYPE, LFS, 0);
1675         up_write(&sit_i->sentry_lock);
1676         return ret;
1677 }
1678
1679 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1680                                 unsigned int start_segno,
1681                                 struct gc_inode_list *gc_list, int gc_type,
1682                                 bool force_migrate)
1683 {
1684         struct page *sum_page;
1685         struct f2fs_summary_block *sum;
1686         struct blk_plug plug;
1687         unsigned int segno = start_segno;
1688         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1689         int seg_freed = 0, migrated = 0;
1690         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1691                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1692         int submitted = 0;
1693
1694         if (__is_large_section(sbi))
1695                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1696
1697         /*
1698          * zone-capacity can be less than zone-size in zoned devices,
1699          * resulting in less than expected usable segments in the zone,
1700          * calculate the end segno in the zone which can be garbage collected
1701          */
1702         if (f2fs_sb_has_blkzoned(sbi))
1703                 end_segno -= sbi->segs_per_sec -
1704                                         f2fs_usable_segs_in_sec(sbi, segno);
1705
1706         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1707
1708         /* readahead multi ssa blocks those have contiguous address */
1709         if (__is_large_section(sbi))
1710                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1711                                         end_segno - segno, META_SSA, true);
1712
1713         /* reference all summary page */
1714         while (segno < end_segno) {
1715                 sum_page = f2fs_get_sum_page(sbi, segno++);
1716                 if (IS_ERR(sum_page)) {
1717                         int err = PTR_ERR(sum_page);
1718
1719                         end_segno = segno - 1;
1720                         for (segno = start_segno; segno < end_segno; segno++) {
1721                                 sum_page = find_get_page(META_MAPPING(sbi),
1722                                                 GET_SUM_BLOCK(sbi, segno));
1723                                 f2fs_put_page(sum_page, 0);
1724                                 f2fs_put_page(sum_page, 0);
1725                         }
1726                         return err;
1727                 }
1728                 unlock_page(sum_page);
1729         }
1730
1731         blk_start_plug(&plug);
1732
1733         for (segno = start_segno; segno < end_segno; segno++) {
1734
1735                 /* find segment summary of victim */
1736                 sum_page = find_get_page(META_MAPPING(sbi),
1737                                         GET_SUM_BLOCK(sbi, segno));
1738                 f2fs_put_page(sum_page, 0);
1739
1740                 if (get_valid_blocks(sbi, segno, false) == 0)
1741                         goto freed;
1742                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1743                                 migrated >= sbi->migration_granularity)
1744                         goto skip;
1745                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1746                         goto skip;
1747
1748                 sum = page_address(sum_page);
1749                 if (type != GET_SUM_TYPE((&sum->footer))) {
1750                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1751                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1752                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1753                         f2fs_stop_checkpoint(sbi, false,
1754                                 STOP_CP_REASON_CORRUPTED_SUMMARY);
1755                         goto skip;
1756                 }
1757
1758                 /*
1759                  * this is to avoid deadlock:
1760                  * - lock_page(sum_page)         - f2fs_replace_block
1761                  *  - check_valid_map()            - down_write(sentry_lock)
1762                  *   - down_read(sentry_lock)     - change_curseg()
1763                  *                                  - lock_page(sum_page)
1764                  */
1765                 if (type == SUM_TYPE_NODE)
1766                         submitted += gc_node_segment(sbi, sum->entries, segno,
1767                                                                 gc_type);
1768                 else
1769                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1770                                                         segno, gc_type,
1771                                                         force_migrate);
1772
1773                 stat_inc_seg_count(sbi, type, gc_type);
1774                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1775                 migrated++;
1776
1777 freed:
1778                 if (gc_type == FG_GC &&
1779                                 get_valid_blocks(sbi, segno, false) == 0)
1780                         seg_freed++;
1781
1782                 if (__is_large_section(sbi))
1783                         sbi->next_victim_seg[gc_type] =
1784                                 (segno + 1 < end_segno) ? segno + 1 : NULL_SEGNO;
1785 skip:
1786                 f2fs_put_page(sum_page, 0);
1787         }
1788
1789         if (submitted)
1790                 f2fs_submit_merged_write(sbi,
1791                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1792
1793         blk_finish_plug(&plug);
1794
1795         stat_inc_call_count(sbi->stat_info);
1796
1797         return seg_freed;
1798 }
1799
1800 int f2fs_gc(struct f2fs_sb_info *sbi, struct f2fs_gc_control *gc_control)
1801 {
1802         int gc_type = gc_control->init_gc_type;
1803         unsigned int segno = gc_control->victim_segno;
1804         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1805         int ret = 0;
1806         struct cp_control cpc;
1807         struct gc_inode_list gc_list = {
1808                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1809                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1810         };
1811         unsigned int skipped_round = 0, round = 0;
1812         unsigned int upper_secs;
1813
1814         trace_f2fs_gc_begin(sbi->sb, gc_type, gc_control->no_bg_gc,
1815                                 gc_control->nr_free_secs,
1816                                 get_pages(sbi, F2FS_DIRTY_NODES),
1817                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1818                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1819                                 free_sections(sbi),
1820                                 free_segments(sbi),
1821                                 reserved_segments(sbi),
1822                                 prefree_segments(sbi));
1823
1824         cpc.reason = __get_cp_reason(sbi);
1825 gc_more:
1826         sbi->skipped_gc_rwsem = 0;
1827         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1828                 ret = -EINVAL;
1829                 goto stop;
1830         }
1831         if (unlikely(f2fs_cp_error(sbi))) {
1832                 ret = -EIO;
1833                 goto stop;
1834         }
1835
1836         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1837                 /*
1838                  * For example, if there are many prefree_segments below given
1839                  * threshold, we can make them free by checkpoint. Then, we
1840                  * secure free segments which doesn't need fggc any more.
1841                  */
1842                 if (prefree_segments(sbi)) {
1843                         ret = f2fs_write_checkpoint(sbi, &cpc);
1844                         if (ret)
1845                                 goto stop;
1846                 }
1847                 if (has_not_enough_free_secs(sbi, 0, 0))
1848                         gc_type = FG_GC;
1849         }
1850
1851         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1852         if (gc_type == BG_GC && gc_control->no_bg_gc) {
1853                 ret = -EINVAL;
1854                 goto stop;
1855         }
1856 retry:
1857         ret = __get_victim(sbi, &segno, gc_type);
1858         if (ret) {
1859                 /* allow to search victim from sections has pinned data */
1860                 if (ret == -ENODATA && gc_type == FG_GC &&
1861                                 f2fs_pinned_section_exists(DIRTY_I(sbi))) {
1862                         f2fs_unpin_all_sections(sbi, false);
1863                         goto retry;
1864                 }
1865                 goto stop;
1866         }
1867
1868         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type,
1869                                 gc_control->should_migrate_blocks);
1870         total_freed += seg_freed;
1871
1872         if (seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1873                 sec_freed++;
1874
1875         if (gc_type == FG_GC)
1876                 sbi->cur_victim_sec = NULL_SEGNO;
1877
1878         if (gc_control->init_gc_type == FG_GC ||
1879             !has_not_enough_free_secs(sbi,
1880                                 (gc_type == FG_GC) ? sec_freed : 0, 0)) {
1881                 if (gc_type == FG_GC && sec_freed < gc_control->nr_free_secs)
1882                         goto go_gc_more;
1883                 goto stop;
1884         }
1885
1886         /* FG_GC stops GC by skip_count */
1887         if (gc_type == FG_GC) {
1888                 if (sbi->skipped_gc_rwsem)
1889                         skipped_round++;
1890                 round++;
1891                 if (skipped_round > MAX_SKIP_GC_COUNT &&
1892                                 skipped_round * 2 >= round) {
1893                         ret = f2fs_write_checkpoint(sbi, &cpc);
1894                         goto stop;
1895                 }
1896         }
1897
1898         __get_secs_required(sbi, NULL, &upper_secs, NULL);
1899
1900         /*
1901          * Write checkpoint to reclaim prefree segments.
1902          * We need more three extra sections for writer's data/node/dentry.
1903          */
1904         if (free_sections(sbi) <= upper_secs + NR_GC_CHECKPOINT_SECS &&
1905                                 prefree_segments(sbi)) {
1906                 ret = f2fs_write_checkpoint(sbi, &cpc);
1907                 if (ret)
1908                         goto stop;
1909         }
1910 go_gc_more:
1911         segno = NULL_SEGNO;
1912         goto gc_more;
1913
1914 stop:
1915         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1916         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = gc_control->victim_segno;
1917
1918         if (gc_type == FG_GC)
1919                 f2fs_unpin_all_sections(sbi, true);
1920
1921         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1922                                 get_pages(sbi, F2FS_DIRTY_NODES),
1923                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1924                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1925                                 free_sections(sbi),
1926                                 free_segments(sbi),
1927                                 reserved_segments(sbi),
1928                                 prefree_segments(sbi));
1929
1930         f2fs_up_write(&sbi->gc_lock);
1931
1932         put_gc_inode(&gc_list);
1933
1934         if (gc_control->err_gc_skipped && !ret)
1935                 ret = sec_freed ? 0 : -EAGAIN;
1936         return ret;
1937 }
1938
1939 int __init f2fs_create_garbage_collection_cache(void)
1940 {
1941         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1942                                         sizeof(struct victim_entry));
1943         if (!victim_entry_slab)
1944                 return -ENOMEM;
1945         return 0;
1946 }
1947
1948 void f2fs_destroy_garbage_collection_cache(void)
1949 {
1950         kmem_cache_destroy(victim_entry_slab);
1951 }
1952
1953 static void init_atgc_management(struct f2fs_sb_info *sbi)
1954 {
1955         struct atgc_management *am = &sbi->am;
1956
1957         if (test_opt(sbi, ATGC) &&
1958                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1959                 am->atgc_enabled = true;
1960
1961         am->root = RB_ROOT_CACHED;
1962         INIT_LIST_HEAD(&am->victim_list);
1963         am->victim_count = 0;
1964
1965         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1966         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1967         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1968         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1969 }
1970
1971 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1972 {
1973         DIRTY_I(sbi)->v_ops = &default_v_ops;
1974
1975         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1976
1977         /* give warm/cold data area from slower device */
1978         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1979                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1980                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1981
1982         init_atgc_management(sbi);
1983 }
1984
1985 static int free_segment_range(struct f2fs_sb_info *sbi,
1986                                 unsigned int secs, bool gc_only)
1987 {
1988         unsigned int segno, next_inuse, start, end;
1989         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1990         int gc_mode, gc_type;
1991         int err = 0;
1992         int type;
1993
1994         /* Force block allocation for GC */
1995         MAIN_SECS(sbi) -= secs;
1996         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1997         end = MAIN_SEGS(sbi) - 1;
1998
1999         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
2000         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
2001                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
2002                         SIT_I(sbi)->last_victim[gc_mode] = 0;
2003
2004         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
2005                 if (sbi->next_victim_seg[gc_type] >= start)
2006                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
2007         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
2008
2009         /* Move out cursegs from the target range */
2010         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
2011                 f2fs_allocate_segment_for_resize(sbi, type, start, end);
2012
2013         /* do GC to move out valid blocks in the range */
2014         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
2015                 struct gc_inode_list gc_list = {
2016                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
2017                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
2018                 };
2019
2020                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
2021                 put_gc_inode(&gc_list);
2022
2023                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
2024                         err = -EAGAIN;
2025                         goto out;
2026                 }
2027                 if (fatal_signal_pending(current)) {
2028                         err = -ERESTARTSYS;
2029                         goto out;
2030                 }
2031         }
2032         if (gc_only)
2033                 goto out;
2034
2035         err = f2fs_write_checkpoint(sbi, &cpc);
2036         if (err)
2037                 goto out;
2038
2039         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
2040         if (next_inuse <= end) {
2041                 f2fs_err(sbi, "segno %u should be free but still inuse!",
2042                          next_inuse);
2043                 f2fs_bug_on(sbi, 1);
2044         }
2045 out:
2046         MAIN_SECS(sbi) += secs;
2047         return err;
2048 }
2049
2050 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
2051 {
2052         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
2053         int section_count;
2054         int segment_count;
2055         int segment_count_main;
2056         long long block_count;
2057         int segs = secs * sbi->segs_per_sec;
2058
2059         f2fs_down_write(&sbi->sb_lock);
2060
2061         section_count = le32_to_cpu(raw_sb->section_count);
2062         segment_count = le32_to_cpu(raw_sb->segment_count);
2063         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
2064         block_count = le64_to_cpu(raw_sb->block_count);
2065
2066         raw_sb->section_count = cpu_to_le32(section_count + secs);
2067         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
2068         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
2069         raw_sb->block_count = cpu_to_le64(block_count +
2070                                         (long long)segs * sbi->blocks_per_seg);
2071         if (f2fs_is_multi_device(sbi)) {
2072                 int last_dev = sbi->s_ndevs - 1;
2073                 int dev_segs =
2074                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
2075
2076                 raw_sb->devs[last_dev].total_segments =
2077                                                 cpu_to_le32(dev_segs + segs);
2078         }
2079
2080         f2fs_up_write(&sbi->sb_lock);
2081 }
2082
2083 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
2084 {
2085         int segs = secs * sbi->segs_per_sec;
2086         long long blks = (long long)segs * sbi->blocks_per_seg;
2087         long long user_block_count =
2088                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
2089
2090         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
2091         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
2092         MAIN_SECS(sbi) += secs;
2093         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
2094         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
2095         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
2096
2097         if (f2fs_is_multi_device(sbi)) {
2098                 int last_dev = sbi->s_ndevs - 1;
2099
2100                 FDEV(last_dev).total_segments =
2101                                 (int)FDEV(last_dev).total_segments + segs;
2102                 FDEV(last_dev).end_blk =
2103                                 (long long)FDEV(last_dev).end_blk + blks;
2104 #ifdef CONFIG_BLK_DEV_ZONED
2105                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
2106                                         (int)(blks >> sbi->log_blocks_per_blkz);
2107 #endif
2108         }
2109 }
2110
2111 int f2fs_resize_fs(struct file *filp, __u64 block_count)
2112 {
2113         struct f2fs_sb_info *sbi = F2FS_I_SB(file_inode(filp));
2114         __u64 old_block_count, shrunk_blocks;
2115         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
2116         unsigned int secs;
2117         int err = 0;
2118         __u32 rem;
2119
2120         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
2121         if (block_count > old_block_count)
2122                 return -EINVAL;
2123
2124         if (f2fs_is_multi_device(sbi)) {
2125                 int last_dev = sbi->s_ndevs - 1;
2126                 __u64 last_segs = FDEV(last_dev).total_segments;
2127
2128                 if (block_count + last_segs * sbi->blocks_per_seg <=
2129                                                                 old_block_count)
2130                         return -EINVAL;
2131         }
2132
2133         /* new fs size should align to section size */
2134         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2135         if (rem)
2136                 return -EINVAL;
2137
2138         if (block_count == old_block_count)
2139                 return 0;
2140
2141         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2142                 f2fs_err(sbi, "Should run fsck to repair first.");
2143                 return -EFSCORRUPTED;
2144         }
2145
2146         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2147                 f2fs_err(sbi, "Checkpoint should be enabled.");
2148                 return -EINVAL;
2149         }
2150
2151         err = mnt_want_write_file(filp);
2152         if (err)
2153                 return err;
2154
2155         shrunk_blocks = old_block_count - block_count;
2156         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2157
2158         /* stop other GC */
2159         if (!f2fs_down_write_trylock(&sbi->gc_lock)) {
2160                 err = -EAGAIN;
2161                 goto out_drop_write;
2162         }
2163
2164         /* stop CP to protect MAIN_SEC in free_segment_range */
2165         f2fs_lock_op(sbi);
2166
2167         spin_lock(&sbi->stat_lock);
2168         if (shrunk_blocks + valid_user_blocks(sbi) +
2169                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2170                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2171                 err = -ENOSPC;
2172         spin_unlock(&sbi->stat_lock);
2173
2174         if (err)
2175                 goto out_unlock;
2176
2177         err = free_segment_range(sbi, secs, true);
2178
2179 out_unlock:
2180         f2fs_unlock_op(sbi);
2181         f2fs_up_write(&sbi->gc_lock);
2182 out_drop_write:
2183         mnt_drop_write_file(filp);
2184         if (err)
2185                 return err;
2186
2187         err = freeze_super(sbi->sb);
2188         if (err)
2189                 return err;
2190
2191         if (f2fs_readonly(sbi->sb)) {
2192                 thaw_super(sbi->sb);
2193                 return -EROFS;
2194         }
2195
2196         f2fs_down_write(&sbi->gc_lock);
2197         f2fs_down_write(&sbi->cp_global_sem);
2198
2199         spin_lock(&sbi->stat_lock);
2200         if (shrunk_blocks + valid_user_blocks(sbi) +
2201                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2202                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2203                 err = -ENOSPC;
2204         else
2205                 sbi->user_block_count -= shrunk_blocks;
2206         spin_unlock(&sbi->stat_lock);
2207         if (err)
2208                 goto out_err;
2209
2210         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2211         err = free_segment_range(sbi, secs, false);
2212         if (err)
2213                 goto recover_out;
2214
2215         update_sb_metadata(sbi, -secs);
2216
2217         err = f2fs_commit_super(sbi, false);
2218         if (err) {
2219                 update_sb_metadata(sbi, secs);
2220                 goto recover_out;
2221         }
2222
2223         update_fs_metadata(sbi, -secs);
2224         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2225         set_sbi_flag(sbi, SBI_IS_DIRTY);
2226
2227         err = f2fs_write_checkpoint(sbi, &cpc);
2228         if (err) {
2229                 update_fs_metadata(sbi, secs);
2230                 update_sb_metadata(sbi, secs);
2231                 f2fs_commit_super(sbi, false);
2232         }
2233 recover_out:
2234         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2235         if (err) {
2236                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2237                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2238
2239                 spin_lock(&sbi->stat_lock);
2240                 sbi->user_block_count += shrunk_blocks;
2241                 spin_unlock(&sbi->stat_lock);
2242         }
2243 out_err:
2244         f2fs_up_write(&sbi->cp_global_sem);
2245         f2fs_up_write(&sbi->gc_lock);
2246         thaw_super(sbi->sb);
2247         return err;
2248 }