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/backing-dev.h>
  11 #include <linux/init.h>
  12 #include <linux/f2fs_fs.h>
  13 #include <linux/kthread.h>
  14 #include <linux/delay.h>
  15 #include <linux/freezer.h>
  16 #include <linux/sched/signal.h>
  17 #include <linux/random.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                         wait_ms = gc_th->urgent_sleep_time;
  96                         down_write(&sbi->gc_lock);
  97                         goto do_gc;
  98                 }
  99
 100                 if (foreground) {
 101                         down_write(&sbi->gc_lock);
 102                         goto do_gc;
 103                 } else if (!down_write_trylock(&sbi->gc_lock)) {
 104                         stat_other_skip_bggc_count(sbi);
 105                         goto next;
 106                 }
 107
 108                 if (!is_idle(sbi, GC_TIME)) {
 109                         increase_sleep_time(gc_th, &wait_ms);
 110                         up_write(&sbi->gc_lock);
 111                         stat_io_skip_bggc_count(sbi);
 112                         goto next;
 113                 }
 114
 115                 if (has_enough_invalid_blocks(sbi))
 116                         decrease_sleep_time(gc_th, &wait_ms);
 117                 else
 118                         increase_sleep_time(gc_th, &wait_ms);
 119 do_gc:
 120                 if (!foreground)
 121                         stat_inc_bggc_count(sbi->stat_info);
 122
 123                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 124
 125                 /* foreground GC was been triggered via f2fs_balance_fs() */
 126                 if (foreground)
 127                         sync_mode = false;
 128
 129                 /* if return value is not zero, no victim was selected */
 130                 if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
 131                         wait_ms = gc_th->no_gc_sleep_time;
 132
 133                 if (foreground)
 134                         wake_up_all(&gc_th->fggc_wq);
 135
 136                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 137                                 prefree_segments(sbi), free_segments(sbi));
 138
 139                 /* balancing f2fs's metadata periodically */
 140                 f2fs_balance_fs_bg(sbi, true);
 141 next:
 142                 sb_end_write(sbi->sb);
 143
 144         } while (!kthread_should_stop());
 145         return 0;
 146 }
 147
 148 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 149 {
 150         struct f2fs_gc_kthread *gc_th;
 151         dev_t dev = sbi->sb->s_bdev->bd_dev;
 152         int err = 0;
 153
 154         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 155         if (!gc_th) {
 156                 err = -ENOMEM;
 157                 goto out;
 158         }
 159
 160         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 161         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 162         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 163         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 164
 165         gc_th->gc_wake = 0;
 166
 167         sbi->gc_thread = gc_th;
 168         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 169         init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 170         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 171                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 172         if (IS_ERR(gc_th->f2fs_gc_task)) {
 173                 err = PTR_ERR(gc_th->f2fs_gc_task);
 174                 kfree(gc_th);
 175                 sbi->gc_thread = NULL;
 176         }
 177 out:
 178         return err;
 179 }
 180
 181 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 182 {
 183         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 184
 185         if (!gc_th)
 186                 return;
 187         kthread_stop(gc_th->f2fs_gc_task);
 188         wake_up_all(&gc_th->fggc_wq);
 189         kfree(gc_th);
 190         sbi->gc_thread = NULL;
 191 }
 192
 193 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 194 {
 195         int gc_mode;
 196
 197         if (gc_type == BG_GC) {
 198                 if (sbi->am.atgc_enabled)
 199                         gc_mode = GC_AT;
 200                 else
 201                         gc_mode = GC_CB;
 202         } else {
 203                 gc_mode = GC_GREEDY;
 204         }
 205
 206         switch (sbi->gc_mode) {
 207         case GC_IDLE_CB:
 208                 gc_mode = GC_CB;
 209                 break;
 210         case GC_IDLE_GREEDY:
 211         case GC_URGENT_HIGH:
 212                 gc_mode = GC_GREEDY;
 213                 break;
 214         case GC_IDLE_AT:
 215                 gc_mode = GC_AT;
 216                 break;
 217         }
 218
 219         return gc_mode;
 220 }
 221
 222 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 223                         int type, struct victim_sel_policy *p)
 224 {
 225         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 226
 227         if (p->alloc_mode == SSR) {
 228                 p->gc_mode = GC_GREEDY;
 229                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 230                 p->max_search = dirty_i->nr_dirty[type];
 231                 p->ofs_unit = 1;
 232         } else if (p->alloc_mode == AT_SSR) {
 233                 p->gc_mode = GC_GREEDY;
 234                 p->dirty_bitmap = dirty_i->dirty_segmap[type];
 235                 p->max_search = dirty_i->nr_dirty[type];
 236                 p->ofs_unit = 1;
 237         } else {
 238                 p->gc_mode = select_gc_type(sbi, gc_type);
 239                 p->ofs_unit = sbi->segs_per_sec;
 240                 if (__is_large_section(sbi)) {
 241                         p->dirty_bitmap = dirty_i->dirty_secmap;
 242                         p->max_search = count_bits(p->dirty_bitmap,
 243                                                 0, MAIN_SECS(sbi));
 244                 } else {
 245                         p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 246                         p->max_search = dirty_i->nr_dirty[DIRTY];
 247                 }
 248         }
 249
 250         /*
 251          * adjust candidates range, should select all dirty segments for
 252          * foreground GC and urgent GC cases.
 253          */
 254         if (gc_type != FG_GC &&
 255                         (sbi->gc_mode != GC_URGENT_HIGH) &&
 256                         (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 257                         p->max_search > sbi->max_victim_search)
 258                 p->max_search = sbi->max_victim_search;
 259
 260         /* let's select beginning hot/small space first in no_heap mode*/
 261         if (f2fs_need_rand_seg(sbi))
 262                 p->offset = prandom_u32() % (MAIN_SECS(sbi) * sbi->segs_per_sec);
 263         else if (test_opt(sbi, NOHEAP) &&
 264                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 265                 p->offset = 0;
 266         else
 267                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 268 }
 269
 270 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 271                                 struct victim_sel_policy *p)
 272 {
 273         /* SSR allocates in a segment unit */
 274         if (p->alloc_mode == SSR)
 275                 return sbi->blocks_per_seg;
 276         else if (p->alloc_mode == AT_SSR)
 277                 return UINT_MAX;
 278
 279         /* LFS */
 280         if (p->gc_mode == GC_GREEDY)
 281                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 282         else if (p->gc_mode == GC_CB)
 283                 return UINT_MAX;
 284         else if (p->gc_mode == GC_AT)
 285                 return UINT_MAX;
 286         else /* No other gc_mode */
 287                 return 0;
 288 }
 289
 290 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 291 {
 292         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 293         unsigned int secno;
 294
 295         /*
 296          * If the gc_type is FG_GC, we can select victim segments
 297          * selected by background GC before.
 298          * Those segments guarantee they have small valid blocks.
 299          */
 300         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 301                 if (sec_usage_check(sbi, secno))
 302                         continue;
 303                 clear_bit(secno, dirty_i->victim_secmap);
 304                 return GET_SEG_FROM_SEC(sbi, secno);
 305         }
 306         return NULL_SEGNO;
 307 }
 308
 309 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 310 {
 311         struct sit_info *sit_i = SIT_I(sbi);
 312         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 313         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 314         unsigned long long mtime = 0;
 315         unsigned int vblocks;
 316         unsigned char age = 0;
 317         unsigned char u;
 318         unsigned int i;
 319         unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 320
 321         for (i = 0; i < usable_segs_per_sec; i++)
 322                 mtime += get_seg_entry(sbi, start + i)->mtime;
 323         vblocks = get_valid_blocks(sbi, segno, true);
 324
 325         mtime = div_u64(mtime, usable_segs_per_sec);
 326         vblocks = div_u64(vblocks, usable_segs_per_sec);
 327
 328         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 329
 330         /* Handle if the system time has changed by the user */
 331         if (mtime < sit_i->min_mtime)
 332                 sit_i->min_mtime = mtime;
 333         if (mtime > sit_i->max_mtime)
 334                 sit_i->max_mtime = mtime;
 335         if (sit_i->max_mtime != sit_i->min_mtime)
 336                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 337                                 sit_i->max_mtime - sit_i->min_mtime);
 338
 339         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 340 }
 341
 342 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 343                         unsigned int segno, struct victim_sel_policy *p)
 344 {
 345         if (p->alloc_mode == SSR)
 346                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 347
 348         /* alloc_mode == LFS */
 349         if (p->gc_mode == GC_GREEDY)
 350                 return get_valid_blocks(sbi, segno, true);
 351         else if (p->gc_mode == GC_CB)
 352                 return get_cb_cost(sbi, segno);
 353
 354         f2fs_bug_on(sbi, 1);
 355         return 0;
 356 }
 357
 358 static unsigned int count_bits(const unsigned long *addr,
 359                                 unsigned int offset, unsigned int len)
 360 {
 361         unsigned int end = offset + len, sum = 0;
 362
 363         while (offset < end) {
 364                 if (test_bit(offset++, addr))
 365                         ++sum;
 366         }
 367         return sum;
 368 }
 369
 370 static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 371                                 unsigned long long mtime, unsigned int segno,
 372                                 struct rb_node *parent, struct rb_node **p,
 373                                 bool left_most)
 374 {
 375         struct atgc_management *am = &sbi->am;
 376         struct victim_entry *ve;
 377
 378         ve =  f2fs_kmem_cache_alloc(victim_entry_slab,
 379                                 GFP_NOFS, true, NULL);
 380
 381         ve->mtime = mtime;
 382         ve->segno = segno;
 383
 384         rb_link_node(&ve->rb_node, parent, p);
 385         rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 386
 387         list_add_tail(&ve->list, &am->victim_list);
 388
 389         am->victim_count++;
 390
 391         return ve;
 392 }
 393
 394 static void insert_victim_entry(struct f2fs_sb_info *sbi,
 395                                 unsigned long long mtime, unsigned int segno)
 396 {
 397         struct atgc_management *am = &sbi->am;
 398         struct rb_node **p;
 399         struct rb_node *parent = NULL;
 400         bool left_most = true;
 401
 402         p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 403         attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 404 }
 405
 406 static void add_victim_entry(struct f2fs_sb_info *sbi,
 407                                 struct victim_sel_policy *p, unsigned int segno)
 408 {
 409         struct sit_info *sit_i = SIT_I(sbi);
 410         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 411         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 412         unsigned long long mtime = 0;
 413         unsigned int i;
 414
 415         if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 416                 if (p->gc_mode == GC_AT &&
 417                         get_valid_blocks(sbi, segno, true) == 0)
 418                         return;
 419         }
 420
 421         for (i = 0; i < sbi->segs_per_sec; i++)
 422                 mtime += get_seg_entry(sbi, start + i)->mtime;
 423         mtime = div_u64(mtime, sbi->segs_per_sec);
 424
 425         /* Handle if the system time has changed by the user */
 426         if (mtime < sit_i->min_mtime)
 427                 sit_i->min_mtime = mtime;
 428         if (mtime > sit_i->max_mtime)
 429                 sit_i->max_mtime = mtime;
 430         if (mtime < sit_i->dirty_min_mtime)
 431                 sit_i->dirty_min_mtime = mtime;
 432         if (mtime > sit_i->dirty_max_mtime)
 433                 sit_i->dirty_max_mtime = mtime;
 434
 435         /* don't choose young section as candidate */
 436         if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 437                 return;
 438
 439         insert_victim_entry(sbi, mtime, segno);
 440 }
 441
 442 static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 443                                                 struct victim_sel_policy *p)
 444 {
 445         struct atgc_management *am = &sbi->am;
 446         struct rb_node *parent = NULL;
 447         bool left_most;
 448
 449         f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 450
 451         return parent;
 452 }
 453
 454 static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 455                                                 struct victim_sel_policy *p)
 456 {
 457         struct sit_info *sit_i = SIT_I(sbi);
 458         struct atgc_management *am = &sbi->am;
 459         struct rb_root_cached *root = &am->root;
 460         struct rb_node *node;
 461         struct rb_entry *re;
 462         struct victim_entry *ve;
 463         unsigned long long total_time;
 464         unsigned long long age, u, accu;
 465         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 466         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 467         unsigned int sec_blocks = BLKS_PER_SEC(sbi);
 468         unsigned int vblocks;
 469         unsigned int dirty_threshold = max(am->max_candidate_count,
 470                                         am->candidate_ratio *
 471                                         am->victim_count / 100);
 472         unsigned int age_weight = am->age_weight;
 473         unsigned int cost;
 474         unsigned int iter = 0;
 475
 476         if (max_mtime < min_mtime)
 477                 return;
 478
 479         max_mtime += 1;
 480         total_time = max_mtime - min_mtime;
 481
 482         accu = div64_u64(ULLONG_MAX, total_time);
 483         accu = min_t(unsigned long long, div_u64(accu, 100),
 484                                         DEFAULT_ACCURACY_CLASS);
 485
 486         node = rb_first_cached(root);
 487 next:
 488         re = rb_entry_safe(node, struct rb_entry, rb_node);
 489         if (!re)
 490                 return;
 491
 492         ve = (struct victim_entry *)re;
 493
 494         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 495                 goto skip;
 496
 497         /* age = 10000 * x% * 60 */
 498         age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 499                                                                 age_weight;
 500
 501         vblocks = get_valid_blocks(sbi, ve->segno, true);
 502         f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 503
 504         /* u = 10000 * x% * 40 */
 505         u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 506                                                         (100 - age_weight);
 507
 508         f2fs_bug_on(sbi, age + u >= UINT_MAX);
 509
 510         cost = UINT_MAX - (age + u);
 511         iter++;
 512
 513         if (cost < p->min_cost ||
 514                         (cost == p->min_cost && age > p->oldest_age)) {
 515                 p->min_cost = cost;
 516                 p->oldest_age = age;
 517                 p->min_segno = ve->segno;
 518         }
 519 skip:
 520         if (iter < dirty_threshold) {
 521                 node = rb_next(node);
 522                 goto next;
 523         }
 524 }
 525
 526 /*
 527  * select candidates around source section in range of
 528  * [target - dirty_threshold, target + dirty_threshold]
 529  */
 530 static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 531                                                 struct victim_sel_policy *p)
 532 {
 533         struct sit_info *sit_i = SIT_I(sbi);
 534         struct atgc_management *am = &sbi->am;
 535         struct rb_node *node;
 536         struct rb_entry *re;
 537         struct victim_entry *ve;
 538         unsigned long long age;
 539         unsigned long long max_mtime = sit_i->dirty_max_mtime;
 540         unsigned long long min_mtime = sit_i->dirty_min_mtime;
 541         unsigned int seg_blocks = sbi->blocks_per_seg;
 542         unsigned int vblocks;
 543         unsigned int dirty_threshold = max(am->max_candidate_count,
 544                                         am->candidate_ratio *
 545                                         am->victim_count / 100);
 546         unsigned int cost;
 547         unsigned int iter = 0;
 548         int stage = 0;
 549
 550         if (max_mtime < min_mtime)
 551                 return;
 552         max_mtime += 1;
 553 next_stage:
 554         node = lookup_central_victim(sbi, p);
 555 next_node:
 556         re = rb_entry_safe(node, struct rb_entry, rb_node);
 557         if (!re) {
 558                 if (stage == 0)
 559                         goto skip_stage;
 560                 return;
 561         }
 562
 563         ve = (struct victim_entry *)re;
 564
 565         if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 566                 goto skip_node;
 567
 568         age = max_mtime - ve->mtime;
 569
 570         vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 571         f2fs_bug_on(sbi, !vblocks);
 572
 573         /* rare case */
 574         if (vblocks == seg_blocks)
 575                 goto skip_node;
 576
 577         iter++;
 578
 579         age = max_mtime - abs(p->age - age);
 580         cost = UINT_MAX - vblocks;
 581
 582         if (cost < p->min_cost ||
 583                         (cost == p->min_cost && age > p->oldest_age)) {
 584                 p->min_cost = cost;
 585                 p->oldest_age = age;
 586                 p->min_segno = ve->segno;
 587         }
 588 skip_node:
 589         if (iter < dirty_threshold) {
 590                 if (stage == 0)
 591                         node = rb_prev(node);
 592                 else if (stage == 1)
 593                         node = rb_next(node);
 594                 goto next_node;
 595         }
 596 skip_stage:
 597         if (stage < 1) {
 598                 stage++;
 599                 iter = 0;
 600                 goto next_stage;
 601         }
 602 }
 603 static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 604                                                 struct victim_sel_policy *p)
 605 {
 606         f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 607                                                 &sbi->am.root, true));
 608
 609         if (p->gc_mode == GC_AT)
 610                 atgc_lookup_victim(sbi, p);
 611         else if (p->alloc_mode == AT_SSR)
 612                 atssr_lookup_victim(sbi, p);
 613         else
 614                 f2fs_bug_on(sbi, 1);
 615 }
 616
 617 static void release_victim_entry(struct f2fs_sb_info *sbi)
 618 {
 619         struct atgc_management *am = &sbi->am;
 620         struct victim_entry *ve, *tmp;
 621
 622         list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 623                 list_del(&ve->list);
 624                 kmem_cache_free(victim_entry_slab, ve);
 625                 am->victim_count--;
 626         }
 627
 628         am->root = RB_ROOT_CACHED;
 629
 630         f2fs_bug_on(sbi, am->victim_count);
 631         f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 632 }
 633
 634 /*
 635  * This function is called from two paths.
 636  * One is garbage collection and the other is SSR segment selection.
 637  * When it is called during GC, it just gets a victim segment
 638  * and it does not remove it from dirty seglist.
 639  * When it is called from SSR segment selection, it finds a segment
 640  * which has minimum valid blocks and removes it from dirty seglist.
 641  */
 642 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 643                         unsigned int *result, int gc_type, int type,
 644                         char alloc_mode, unsigned long long age)
 645 {
 646         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 647         struct sit_info *sm = SIT_I(sbi);
 648         struct victim_sel_policy p;
 649         unsigned int secno, last_victim;
 650         unsigned int last_segment;
 651         unsigned int nsearched;
 652         bool is_atgc;
 653         int ret = 0;
 654
 655         mutex_lock(&dirty_i->seglist_lock);
 656         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 657
 658         p.alloc_mode = alloc_mode;
 659         p.age = age;
 660         p.age_threshold = sbi->am.age_threshold;
 661
 662 retry:
 663         select_policy(sbi, gc_type, type, &p);
 664         p.min_segno = NULL_SEGNO;
 665         p.oldest_age = 0;
 666         p.min_cost = get_max_cost(sbi, &p);
 667
 668         is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 669         nsearched = 0;
 670
 671         if (is_atgc)
 672                 SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 673
 674         if (*result != NULL_SEGNO) {
 675                 if (!get_valid_blocks(sbi, *result, false)) {
 676                         ret = -ENODATA;
 677                         goto out;
 678                 }
 679
 680                 if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 681                         ret = -EBUSY;
 682                 else
 683                         p.min_segno = *result;
 684                 goto out;
 685         }
 686
 687         ret = -ENODATA;
 688         if (p.max_search == 0)
 689                 goto out;
 690
 691         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 692                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 693                         p.min_segno = sbi->next_victim_seg[BG_GC];
 694                         *result = p.min_segno;
 695                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 696                         goto got_result;
 697                 }
 698                 if (gc_type == FG_GC &&
 699                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 700                         p.min_segno = sbi->next_victim_seg[FG_GC];
 701                         *result = p.min_segno;
 702                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 703                         goto got_result;
 704                 }
 705         }
 706
 707         last_victim = sm->last_victim[p.gc_mode];
 708         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 709                 p.min_segno = check_bg_victims(sbi);
 710                 if (p.min_segno != NULL_SEGNO)
 711                         goto got_it;
 712         }
 713
 714         while (1) {
 715                 unsigned long cost, *dirty_bitmap;
 716                 unsigned int unit_no, segno;
 717
 718                 dirty_bitmap = p.dirty_bitmap;
 719                 unit_no = find_next_bit(dirty_bitmap,
 720                                 last_segment / p.ofs_unit,
 721                                 p.offset / p.ofs_unit);
 722                 segno = unit_no * p.ofs_unit;
 723                 if (segno >= last_segment) {
 724                         if (sm->last_victim[p.gc_mode]) {
 725                                 last_segment =
 726                                         sm->last_victim[p.gc_mode];
 727                                 sm->last_victim[p.gc_mode] = 0;
 728                                 p.offset = 0;
 729                                 continue;
 730                         }
 731                         break;
 732                 }
 733
 734                 p.offset = segno + p.ofs_unit;
 735                 nsearched++;
 736
 737 #ifdef CONFIG_F2FS_CHECK_FS
 738                 /*
 739                  * skip selecting the invalid segno (that is failed due to block
 740                  * validity check failure during GC) to avoid endless GC loop in
 741                  * such cases.
 742                  */
 743                 if (test_bit(segno, sm->invalid_segmap))
 744                         goto next;
 745 #endif
 746
 747                 secno = GET_SEC_FROM_SEG(sbi, segno);
 748
 749                 if (sec_usage_check(sbi, secno))
 750                         goto next;
 751
 752                 /* Don't touch checkpointed data */
 753                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 754                         if (p.alloc_mode == LFS) {
 755                                 /*
 756                                  * LFS is set to find source section during GC.
 757                                  * The victim should have no checkpointed data.
 758                                  */
 759                                 if (get_ckpt_valid_blocks(sbi, segno, true))
 760                                         goto next;
 761                         } else {
 762                                 /*
 763                                  * SSR | AT_SSR are set to find target segment
 764                                  * for writes which can be full by checkpointed
 765                                  * and newly written blocks.
 766                                  */
 767                                 if (!f2fs_segment_has_free_slot(sbi, segno))
 768                                         goto next;
 769                         }
 770                 }
 771
 772                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 773                         goto next;
 774
 775                 if (is_atgc) {
 776                         add_victim_entry(sbi, &p, segno);
 777                         goto next;
 778                 }
 779
 780                 cost = get_gc_cost(sbi, segno, &p);
 781
 782                 if (p.min_cost > cost) {
 783                         p.min_segno = segno;
 784                         p.min_cost = cost;
 785                 }
 786 next:
 787                 if (nsearched >= p.max_search) {
 788                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 789                                 sm->last_victim[p.gc_mode] =
 790                                         last_victim + p.ofs_unit;
 791                         else
 792                                 sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 793                         sm->last_victim[p.gc_mode] %=
 794                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 795                         break;
 796                 }
 797         }
 798
 799         /* get victim for GC_AT/AT_SSR */
 800         if (is_atgc) {
 801                 lookup_victim_by_age(sbi, &p);
 802                 release_victim_entry(sbi);
 803         }
 804
 805         if (is_atgc && p.min_segno == NULL_SEGNO &&
 806                         sm->elapsed_time < p.age_threshold) {
 807                 p.age_threshold = 0;
 808                 goto retry;
 809         }
 810
 811         if (p.min_segno != NULL_SEGNO) {
 812 got_it:
 813                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 814 got_result:
 815                 if (p.alloc_mode == LFS) {
 816                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 817                         if (gc_type == FG_GC)
 818                                 sbi->cur_victim_sec = secno;
 819                         else
 820                                 set_bit(secno, dirty_i->victim_secmap);
 821                 }
 822                 ret = 0;
 823
 824         }
 825 out:
 826         if (p.min_segno != NULL_SEGNO)
 827                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 828                                 sbi->cur_victim_sec,
 829                                 prefree_segments(sbi), free_segments(sbi));
 830         mutex_unlock(&dirty_i->seglist_lock);
 831
 832         return ret;
 833 }
 834
 835 static const struct victim_selection default_v_ops = {
 836         .get_victim = get_victim_by_default,
 837 };
 838
 839 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 840 {
 841         struct inode_entry *ie;
 842
 843         ie = radix_tree_lookup(&gc_list->iroot, ino);
 844         if (ie)
 845                 return ie->inode;
 846         return NULL;
 847 }
 848
 849 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 850 {
 851         struct inode_entry *new_ie;
 852
 853         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 854                 iput(inode);
 855                 return;
 856         }
 857         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab,
 858                                         GFP_NOFS, true, NULL);
 859         new_ie->inode = inode;
 860
 861         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 862         list_add_tail(&new_ie->list, &gc_list->ilist);
 863 }
 864
 865 static void put_gc_inode(struct gc_inode_list *gc_list)
 866 {
 867         struct inode_entry *ie, *next_ie;
 868
 869         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 870                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 871                 iput(ie->inode);
 872                 list_del(&ie->list);
 873                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 874         }
 875 }
 876
 877 static int check_valid_map(struct f2fs_sb_info *sbi,
 878                                 unsigned int segno, int offset)
 879 {
 880         struct sit_info *sit_i = SIT_I(sbi);
 881         struct seg_entry *sentry;
 882         int ret;
 883
 884         down_read(&sit_i->sentry_lock);
 885         sentry = get_seg_entry(sbi, segno);
 886         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 887         up_read(&sit_i->sentry_lock);
 888         return ret;
 889 }
 890
 891 /*
 892  * This function compares node address got in summary with that in NAT.
 893  * On validity, copy that node with cold status, otherwise (invalid node)
 894  * ignore that.
 895  */
 896 static int gc_node_segment(struct f2fs_sb_info *sbi,
 897                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 898 {
 899         struct f2fs_summary *entry;
 900         block_t start_addr;
 901         int off;
 902         int phase = 0;
 903         bool fggc = (gc_type == FG_GC);
 904         int submitted = 0;
 905         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 906
 907         start_addr = START_BLOCK(sbi, segno);
 908
 909 next_step:
 910         entry = sum;
 911
 912         if (fggc && phase == 2)
 913                 atomic_inc(&sbi->wb_sync_req[NODE]);
 914
 915         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 916                 nid_t nid = le32_to_cpu(entry->nid);
 917                 struct page *node_page;
 918                 struct node_info ni;
 919                 int err;
 920
 921                 /* stop BG_GC if there is not enough free sections. */
 922                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 923                         return submitted;
 924
 925                 if (check_valid_map(sbi, segno, off) == 0)
 926                         continue;
 927
 928                 if (phase == 0) {
 929                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 930                                                         META_NAT, true);
 931                         continue;
 932                 }
 933
 934                 if (phase == 1) {
 935                         f2fs_ra_node_page(sbi, nid);
 936                         continue;
 937                 }
 938
 939                 /* phase == 2 */
 940                 node_page = f2fs_get_node_page(sbi, nid);
 941                 if (IS_ERR(node_page))
 942                         continue;
 943
 944                 /* block may become invalid during f2fs_get_node_page */
 945                 if (check_valid_map(sbi, segno, off) == 0) {
 946                         f2fs_put_page(node_page, 1);
 947                         continue;
 948                 }
 949
 950                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 951                         f2fs_put_page(node_page, 1);
 952                         continue;
 953                 }
 954
 955                 if (ni.blk_addr != start_addr + off) {
 956                         f2fs_put_page(node_page, 1);
 957                         continue;
 958                 }
 959
 960                 err = f2fs_move_node_page(node_page, gc_type);
 961                 if (!err && gc_type == FG_GC)
 962                         submitted++;
 963                 stat_inc_node_blk_count(sbi, 1, gc_type);
 964         }
 965
 966         if (++phase < 3)
 967                 goto next_step;
 968
 969         if (fggc)
 970                 atomic_dec(&sbi->wb_sync_req[NODE]);
 971         return submitted;
 972 }
 973
 974 /*
 975  * Calculate start block index indicating the given node offset.
 976  * Be careful, caller should give this node offset only indicating direct node
 977  * blocks. If any node offsets, which point the other types of node blocks such
 978  * as indirect or double indirect node blocks, are given, it must be a caller's
 979  * bug.
 980  */
 981 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 982 {
 983         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 984         unsigned int bidx;
 985
 986         if (node_ofs == 0)
 987                 return 0;
 988
 989         if (node_ofs <= 2) {
 990                 bidx = node_ofs - 1;
 991         } else if (node_ofs <= indirect_blks) {
 992                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 993
 994                 bidx = node_ofs - 2 - dec;
 995         } else {
 996                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 997
 998                 bidx = node_ofs - 5 - dec;
 999         }
1000         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
1001 }
1002
1003 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1004                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
1005 {
1006         struct page *node_page;
1007         nid_t nid;
1008         unsigned int ofs_in_node;
1009         block_t source_blkaddr;
1010
1011         nid = le32_to_cpu(sum->nid);
1012         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1013
1014         node_page = f2fs_get_node_page(sbi, nid);
1015         if (IS_ERR(node_page))
1016                 return false;
1017
1018         if (f2fs_get_node_info(sbi, nid, dni)) {
1019                 f2fs_put_page(node_page, 1);
1020                 return false;
1021         }
1022
1023         if (sum->version != dni->version) {
1024                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1025                           __func__);
1026                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1027         }
1028
1029         if (f2fs_check_nid_range(sbi, dni->ino))
1030                 return false;
1031
1032         *nofs = ofs_of_node(node_page);
1033         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1034         f2fs_put_page(node_page, 1);
1035
1036         if (source_blkaddr != blkaddr) {
1037 #ifdef CONFIG_F2FS_CHECK_FS
1038                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
1039                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1040
1041                 if (unlikely(check_valid_map(sbi, segno, offset))) {
1042                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1043                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1044                                          blkaddr, source_blkaddr, segno);
1045                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1046                         }
1047                 }
1048 #endif
1049                 return false;
1050         }
1051         return true;
1052 }
1053
1054 static int ra_data_block(struct inode *inode, pgoff_t index)
1055 {
1056         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1057         struct address_space *mapping = inode->i_mapping;
1058         struct dnode_of_data dn;
1059         struct page *page;
1060         struct extent_info ei = {0, 0, 0};
1061         struct f2fs_io_info fio = {
1062                 .sbi = sbi,
1063                 .ino = inode->i_ino,
1064                 .type = DATA,
1065                 .temp = COLD,
1066                 .op = REQ_OP_READ,
1067                 .op_flags = 0,
1068                 .encrypted_page = NULL,
1069                 .in_list = false,
1070                 .retry = false,
1071         };
1072         int err;
1073
1074         page = f2fs_grab_cache_page(mapping, index, true);
1075         if (!page)
1076                 return -ENOMEM;
1077
1078         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1079                 dn.data_blkaddr = ei.blk + index - ei.fofs;
1080                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1081                                                 DATA_GENERIC_ENHANCE_READ))) {
1082                         err = -EFSCORRUPTED;
1083                         goto put_page;
1084                 }
1085                 goto got_it;
1086         }
1087
1088         set_new_dnode(&dn, inode, NULL, NULL, 0);
1089         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1090         if (err)
1091                 goto put_page;
1092         f2fs_put_dnode(&dn);
1093
1094         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1095                 err = -ENOENT;
1096                 goto put_page;
1097         }
1098         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1099                                                 DATA_GENERIC_ENHANCE))) {
1100                 err = -EFSCORRUPTED;
1101                 goto put_page;
1102         }
1103 got_it:
1104         /* read page */
1105         fio.page = page;
1106         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1107
1108         /*
1109          * don't cache encrypted data into meta inode until previous dirty
1110          * data were writebacked to avoid racing between GC and flush.
1111          */
1112         f2fs_wait_on_page_writeback(page, DATA, true, true);
1113
1114         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1115
1116         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1117                                         dn.data_blkaddr,
1118                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
1119         if (!fio.encrypted_page) {
1120                 err = -ENOMEM;
1121                 goto put_page;
1122         }
1123
1124         err = f2fs_submit_page_bio(&fio);
1125         if (err)
1126                 goto put_encrypted_page;
1127         f2fs_put_page(fio.encrypted_page, 0);
1128         f2fs_put_page(page, 1);
1129
1130         f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1131         f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1132
1133         return 0;
1134 put_encrypted_page:
1135         f2fs_put_page(fio.encrypted_page, 1);
1136 put_page:
1137         f2fs_put_page(page, 1);
1138         return err;
1139 }
1140
1141 /*
1142  * Move data block via META_MAPPING while keeping locked data page.
1143  * This can be used to move blocks, aka LBAs, directly on disk.
1144  */
1145 static int move_data_block(struct inode *inode, block_t bidx,
1146                                 int gc_type, unsigned int segno, int off)
1147 {
1148         struct f2fs_io_info fio = {
1149                 .sbi = F2FS_I_SB(inode),
1150                 .ino = inode->i_ino,
1151                 .type = DATA,
1152                 .temp = COLD,
1153                 .op = REQ_OP_READ,
1154                 .op_flags = 0,
1155                 .encrypted_page = NULL,
1156                 .in_list = false,
1157                 .retry = false,
1158         };
1159         struct dnode_of_data dn;
1160         struct f2fs_summary sum;
1161         struct node_info ni;
1162         struct page *page, *mpage;
1163         block_t newaddr;
1164         int err = 0;
1165         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1166         int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1167                                 (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1168                                 CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1169
1170         /* do not read out */
1171         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1172         if (!page)
1173                 return -ENOMEM;
1174
1175         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1176                 err = -ENOENT;
1177                 goto out;
1178         }
1179
1180         if (f2fs_is_atomic_file(inode)) {
1181                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1182                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1183                 err = -EAGAIN;
1184                 goto out;
1185         }
1186
1187         if (f2fs_is_pinned_file(inode)) {
1188                 f2fs_pin_file_control(inode, true);
1189                 err = -EAGAIN;
1190                 goto out;
1191         }
1192
1193         set_new_dnode(&dn, inode, NULL, NULL, 0);
1194         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1195         if (err)
1196                 goto out;
1197
1198         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1199                 ClearPageUptodate(page);
1200                 err = -ENOENT;
1201                 goto put_out;
1202         }
1203
1204         /*
1205          * don't cache encrypted data into meta inode until previous dirty
1206          * data were writebacked to avoid racing between GC and flush.
1207          */
1208         f2fs_wait_on_page_writeback(page, DATA, true, true);
1209
1210         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1211
1212         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
1213         if (err)
1214                 goto put_out;
1215
1216         /* read page */
1217         fio.page = page;
1218         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1219
1220         if (lfs_mode)
1221                 down_write(&fio.sbi->io_order_lock);
1222
1223         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1224                                         fio.old_blkaddr, false);
1225         if (!mpage) {
1226                 err = -ENOMEM;
1227                 goto up_out;
1228         }
1229
1230         fio.encrypted_page = mpage;
1231
1232         /* read source block in mpage */
1233         if (!PageUptodate(mpage)) {
1234                 err = f2fs_submit_page_bio(&fio);
1235                 if (err) {
1236                         f2fs_put_page(mpage, 1);
1237                         goto up_out;
1238                 }
1239
1240                 f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1241                 f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1242
1243                 lock_page(mpage);
1244                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1245                                                 !PageUptodate(mpage))) {
1246                         err = -EIO;
1247                         f2fs_put_page(mpage, 1);
1248                         goto up_out;
1249                 }
1250         }
1251
1252         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1253
1254         /* allocate block address */
1255         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1256                                 &sum, type, NULL);
1257
1258         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1259                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1260         if (!fio.encrypted_page) {
1261                 err = -ENOMEM;
1262                 f2fs_put_page(mpage, 1);
1263                 goto recover_block;
1264         }
1265
1266         /* write target block */
1267         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1268         memcpy(page_address(fio.encrypted_page),
1269                                 page_address(mpage), PAGE_SIZE);
1270         f2fs_put_page(mpage, 1);
1271         invalidate_mapping_pages(META_MAPPING(fio.sbi),
1272                                 fio.old_blkaddr, fio.old_blkaddr);
1273         f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1274
1275         set_page_dirty(fio.encrypted_page);
1276         if (clear_page_dirty_for_io(fio.encrypted_page))
1277                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
1278
1279         set_page_writeback(fio.encrypted_page);
1280         ClearPageError(page);
1281
1282         fio.op = REQ_OP_WRITE;
1283         fio.op_flags = REQ_SYNC;
1284         fio.new_blkaddr = newaddr;
1285         f2fs_submit_page_write(&fio);
1286         if (fio.retry) {
1287                 err = -EAGAIN;
1288                 if (PageWriteback(fio.encrypted_page))
1289                         end_page_writeback(fio.encrypted_page);
1290                 goto put_page_out;
1291         }
1292
1293         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1294
1295         f2fs_update_data_blkaddr(&dn, newaddr);
1296         set_inode_flag(inode, FI_APPEND_WRITE);
1297         if (page->index == 0)
1298                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1299 put_page_out:
1300         f2fs_put_page(fio.encrypted_page, 1);
1301 recover_block:
1302         if (err)
1303                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1304                                                         true, true, true);
1305 up_out:
1306         if (lfs_mode)
1307                 up_write(&fio.sbi->io_order_lock);
1308 put_out:
1309         f2fs_put_dnode(&dn);
1310 out:
1311         f2fs_put_page(page, 1);
1312         return err;
1313 }
1314
1315 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1316                                                         unsigned int segno, int off)
1317 {
1318         struct page *page;
1319         int err = 0;
1320
1321         page = f2fs_get_lock_data_page(inode, bidx, true);
1322         if (IS_ERR(page))
1323                 return PTR_ERR(page);
1324
1325         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1326                 err = -ENOENT;
1327                 goto out;
1328         }
1329
1330         if (f2fs_is_atomic_file(inode)) {
1331                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1332                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1333                 err = -EAGAIN;
1334                 goto out;
1335         }
1336         if (f2fs_is_pinned_file(inode)) {
1337                 if (gc_type == FG_GC)
1338                         f2fs_pin_file_control(inode, true);
1339                 err = -EAGAIN;
1340                 goto out;
1341         }
1342
1343         if (gc_type == BG_GC) {
1344                 if (PageWriteback(page)) {
1345                         err = -EAGAIN;
1346                         goto out;
1347                 }
1348                 set_page_dirty(page);
1349                 set_page_private_gcing(page);
1350         } else {
1351                 struct f2fs_io_info fio = {
1352                         .sbi = F2FS_I_SB(inode),
1353                         .ino = inode->i_ino,
1354                         .type = DATA,
1355                         .temp = COLD,
1356                         .op = REQ_OP_WRITE,
1357                         .op_flags = REQ_SYNC,
1358                         .old_blkaddr = NULL_ADDR,
1359                         .page = page,
1360                         .encrypted_page = NULL,
1361                         .need_lock = LOCK_REQ,
1362                         .io_type = FS_GC_DATA_IO,
1363                 };
1364                 bool is_dirty = PageDirty(page);
1365
1366 retry:
1367                 f2fs_wait_on_page_writeback(page, DATA, true, true);
1368
1369                 set_page_dirty(page);
1370                 if (clear_page_dirty_for_io(page)) {
1371                         inode_dec_dirty_pages(inode);
1372                         f2fs_remove_dirty_inode(inode);
1373                 }
1374
1375                 set_page_private_gcing(page);
1376
1377                 err = f2fs_do_write_data_page(&fio);
1378                 if (err) {
1379                         clear_page_private_gcing(page);
1380                         if (err == -ENOMEM) {
1381                                 congestion_wait(BLK_RW_ASYNC,
1382                                                 DEFAULT_IO_TIMEOUT);
1383                                 goto retry;
1384                         }
1385                         if (is_dirty)
1386                                 set_page_dirty(page);
1387                 }
1388         }
1389 out:
1390         f2fs_put_page(page, 1);
1391         return err;
1392 }
1393
1394 /*
1395  * This function tries to get parent node of victim data block, and identifies
1396  * data block validity. If the block is valid, copy that with cold status and
1397  * modify parent node.
1398  * If the parent node is not valid or the data block address is different,
1399  * the victim data block is ignored.
1400  */
1401 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1402                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1403                 bool force_migrate)
1404 {
1405         struct super_block *sb = sbi->sb;
1406         struct f2fs_summary *entry;
1407         block_t start_addr;
1408         int off;
1409         int phase = 0;
1410         int submitted = 0;
1411         unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1412
1413         start_addr = START_BLOCK(sbi, segno);
1414
1415 next_step:
1416         entry = sum;
1417
1418         for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1419                 struct page *data_page;
1420                 struct inode *inode;
1421                 struct node_info dni; /* dnode info for the data */
1422                 unsigned int ofs_in_node, nofs;
1423                 block_t start_bidx;
1424                 nid_t nid = le32_to_cpu(entry->nid);
1425
1426                 /*
1427                  * stop BG_GC if there is not enough free sections.
1428                  * Or, stop GC if the segment becomes fully valid caused by
1429                  * race condition along with SSR block allocation.
1430                  */
1431                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1432                         (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1433                                                         BLKS_PER_SEC(sbi)))
1434                         return submitted;
1435
1436                 if (check_valid_map(sbi, segno, off) == 0)
1437                         continue;
1438
1439                 if (phase == 0) {
1440                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1441                                                         META_NAT, true);
1442                         continue;
1443                 }
1444
1445                 if (phase == 1) {
1446                         f2fs_ra_node_page(sbi, nid);
1447                         continue;
1448                 }
1449
1450                 /* Get an inode by ino with checking validity */
1451                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1452                         continue;
1453
1454                 if (phase == 2) {
1455                         f2fs_ra_node_page(sbi, dni.ino);
1456                         continue;
1457                 }
1458
1459                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1460
1461                 if (phase == 3) {
1462                         inode = f2fs_iget(sb, dni.ino);
1463                         if (IS_ERR(inode) || is_bad_inode(inode) ||
1464                                         special_file(inode->i_mode))
1465                                 continue;
1466
1467                         if (!down_write_trylock(
1468                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1469                                 iput(inode);
1470                                 sbi->skipped_gc_rwsem++;
1471                                 continue;
1472                         }
1473
1474                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1475                                                                 ofs_in_node;
1476
1477                         if (f2fs_post_read_required(inode)) {
1478                                 int err = ra_data_block(inode, start_bidx);
1479
1480                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1481                                 if (err) {
1482                                         iput(inode);
1483                                         continue;
1484                                 }
1485                                 add_gc_inode(gc_list, inode);
1486                                 continue;
1487                         }
1488
1489                         data_page = f2fs_get_read_data_page(inode,
1490                                                 start_bidx, REQ_RAHEAD, true);
1491                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1492                         if (IS_ERR(data_page)) {
1493                                 iput(inode);
1494                                 continue;
1495                         }
1496
1497                         f2fs_put_page(data_page, 0);
1498                         add_gc_inode(gc_list, inode);
1499                         continue;
1500                 }
1501
1502                 /* phase 4 */
1503                 inode = find_gc_inode(gc_list, dni.ino);
1504                 if (inode) {
1505                         struct f2fs_inode_info *fi = F2FS_I(inode);
1506                         bool locked = false;
1507                         int err;
1508
1509                         if (S_ISREG(inode->i_mode)) {
1510                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ])) {
1511                                         sbi->skipped_gc_rwsem++;
1512                                         continue;
1513                                 }
1514                                 if (!down_write_trylock(
1515                                                 &fi->i_gc_rwsem[WRITE])) {
1516                                         sbi->skipped_gc_rwsem++;
1517                                         up_write(&fi->i_gc_rwsem[READ]);
1518                                         continue;
1519                                 }
1520                                 locked = true;
1521
1522                                 /* wait for all inflight aio data */
1523                                 inode_dio_wait(inode);
1524                         }
1525
1526                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1527                                                                 + ofs_in_node;
1528                         if (f2fs_post_read_required(inode))
1529                                 err = move_data_block(inode, start_bidx,
1530                                                         gc_type, segno, off);
1531                         else
1532                                 err = move_data_page(inode, start_bidx, gc_type,
1533                                                                 segno, off);
1534
1535                         if (!err && (gc_type == FG_GC ||
1536                                         f2fs_post_read_required(inode)))
1537                                 submitted++;
1538
1539                         if (locked) {
1540                                 up_write(&fi->i_gc_rwsem[WRITE]);
1541                                 up_write(&fi->i_gc_rwsem[READ]);
1542                         }
1543
1544                         stat_inc_data_blk_count(sbi, 1, gc_type);
1545                 }
1546         }
1547
1548         if (++phase < 5)
1549                 goto next_step;
1550
1551         return submitted;
1552 }
1553
1554 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1555                         int gc_type)
1556 {
1557         struct sit_info *sit_i = SIT_I(sbi);
1558         int ret;
1559
1560         down_write(&sit_i->sentry_lock);
1561         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1562                                               NO_CHECK_TYPE, LFS, 0);
1563         up_write(&sit_i->sentry_lock);
1564         return ret;
1565 }
1566
1567 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1568                                 unsigned int start_segno,
1569                                 struct gc_inode_list *gc_list, int gc_type,
1570                                 bool force_migrate)
1571 {
1572         struct page *sum_page;
1573         struct f2fs_summary_block *sum;
1574         struct blk_plug plug;
1575         unsigned int segno = start_segno;
1576         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1577         int seg_freed = 0, migrated = 0;
1578         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1579                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1580         int submitted = 0;
1581
1582         if (__is_large_section(sbi))
1583                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1584
1585         /*
1586          * zone-capacity can be less than zone-size in zoned devices,
1587          * resulting in less than expected usable segments in the zone,
1588          * calculate the end segno in the zone which can be garbage collected
1589          */
1590         if (f2fs_sb_has_blkzoned(sbi))
1591                 end_segno -= sbi->segs_per_sec -
1592                                         f2fs_usable_segs_in_sec(sbi, segno);
1593
1594         sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1595
1596         /* readahead multi ssa blocks those have contiguous address */
1597         if (__is_large_section(sbi))
1598                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1599                                         end_segno - segno, META_SSA, true);
1600
1601         /* reference all summary page */
1602         while (segno < end_segno) {
1603                 sum_page = f2fs_get_sum_page(sbi, segno++);
1604                 if (IS_ERR(sum_page)) {
1605                         int err = PTR_ERR(sum_page);
1606
1607                         end_segno = segno - 1;
1608                         for (segno = start_segno; segno < end_segno; segno++) {
1609                                 sum_page = find_get_page(META_MAPPING(sbi),
1610                                                 GET_SUM_BLOCK(sbi, segno));
1611                                 f2fs_put_page(sum_page, 0);
1612                                 f2fs_put_page(sum_page, 0);
1613                         }
1614                         return err;
1615                 }
1616                 unlock_page(sum_page);
1617         }
1618
1619         blk_start_plug(&plug);
1620
1621         for (segno = start_segno; segno < end_segno; segno++) {
1622
1623                 /* find segment summary of victim */
1624                 sum_page = find_get_page(META_MAPPING(sbi),
1625                                         GET_SUM_BLOCK(sbi, segno));
1626                 f2fs_put_page(sum_page, 0);
1627
1628                 if (get_valid_blocks(sbi, segno, false) == 0)
1629                         goto freed;
1630                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1631                                 migrated >= sbi->migration_granularity)
1632                         goto skip;
1633                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1634                         goto skip;
1635
1636                 sum = page_address(sum_page);
1637                 if (type != GET_SUM_TYPE((&sum->footer))) {
1638                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1639                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1640                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1641                         f2fs_stop_checkpoint(sbi, false);
1642                         goto skip;
1643                 }
1644
1645                 /*
1646                  * this is to avoid deadlock:
1647                  * - lock_page(sum_page)         - f2fs_replace_block
1648                  *  - check_valid_map()            - down_write(sentry_lock)
1649                  *   - down_read(sentry_lock)     - change_curseg()
1650                  *                                  - lock_page(sum_page)
1651                  */
1652                 if (type == SUM_TYPE_NODE)
1653                         submitted += gc_node_segment(sbi, sum->entries, segno,
1654                                                                 gc_type);
1655                 else
1656                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1657                                                         segno, gc_type,
1658                                                         force_migrate);
1659
1660                 stat_inc_seg_count(sbi, type, gc_type);
1661                 sbi->gc_reclaimed_segs[sbi->gc_mode]++;
1662                 migrated++;
1663
1664 freed:
1665                 if (gc_type == FG_GC &&
1666                                 get_valid_blocks(sbi, segno, false) == 0)
1667                         seg_freed++;
1668
1669                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1670                         sbi->next_victim_seg[gc_type] = segno + 1;
1671 skip:
1672                 f2fs_put_page(sum_page, 0);
1673         }
1674
1675         if (submitted)
1676                 f2fs_submit_merged_write(sbi,
1677                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1678
1679         blk_finish_plug(&plug);
1680
1681         stat_inc_call_count(sbi->stat_info);
1682
1683         return seg_freed;
1684 }
1685
1686 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1687                         bool background, bool force, unsigned int segno)
1688 {
1689         int gc_type = sync ? FG_GC : BG_GC;
1690         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1691         int ret = 0;
1692         struct cp_control cpc;
1693         unsigned int init_segno = segno;
1694         struct gc_inode_list gc_list = {
1695                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1696                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1697         };
1698         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1699         unsigned long long first_skipped;
1700         unsigned int skipped_round = 0, round = 0;
1701
1702         trace_f2fs_gc_begin(sbi->sb, sync, background,
1703                                 get_pages(sbi, F2FS_DIRTY_NODES),
1704                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1705                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1706                                 free_sections(sbi),
1707                                 free_segments(sbi),
1708                                 reserved_segments(sbi),
1709                                 prefree_segments(sbi));
1710
1711         cpc.reason = __get_cp_reason(sbi);
1712         sbi->skipped_gc_rwsem = 0;
1713         first_skipped = last_skipped;
1714 gc_more:
1715         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1716                 ret = -EINVAL;
1717                 goto stop;
1718         }
1719         if (unlikely(f2fs_cp_error(sbi))) {
1720                 ret = -EIO;
1721                 goto stop;
1722         }
1723
1724         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1725                 /*
1726                  * For example, if there are many prefree_segments below given
1727                  * threshold, we can make them free by checkpoint. Then, we
1728                  * secure free segments which doesn't need fggc any more.
1729                  */
1730                 if (prefree_segments(sbi) &&
1731                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1732                         ret = f2fs_write_checkpoint(sbi, &cpc);
1733                         if (ret)
1734                                 goto stop;
1735                 }
1736                 if (has_not_enough_free_secs(sbi, 0, 0))
1737                         gc_type = FG_GC;
1738         }
1739
1740         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1741         if (gc_type == BG_GC && !background) {
1742                 ret = -EINVAL;
1743                 goto stop;
1744         }
1745         ret = __get_victim(sbi, &segno, gc_type);
1746         if (ret)
1747                 goto stop;
1748
1749         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1750         if (gc_type == FG_GC &&
1751                 seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1752                 sec_freed++;
1753         total_freed += seg_freed;
1754
1755         if (gc_type == FG_GC) {
1756                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1757                                                 sbi->skipped_gc_rwsem)
1758                         skipped_round++;
1759                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1760                 round++;
1761         }
1762
1763         if (gc_type == FG_GC)
1764                 sbi->cur_victim_sec = NULL_SEGNO;
1765
1766         if (sync)
1767                 goto stop;
1768
1769         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1770                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1771                                         skipped_round * 2 < round) {
1772                         segno = NULL_SEGNO;
1773                         goto gc_more;
1774                 }
1775
1776                 if (first_skipped < last_skipped &&
1777                                 (last_skipped - first_skipped) >
1778                                                 sbi->skipped_gc_rwsem) {
1779                         f2fs_drop_inmem_pages_all(sbi, true);
1780                         segno = NULL_SEGNO;
1781                         goto gc_more;
1782                 }
1783                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1784                         ret = f2fs_write_checkpoint(sbi, &cpc);
1785         }
1786 stop:
1787         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1788         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1789
1790         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1791                                 get_pages(sbi, F2FS_DIRTY_NODES),
1792                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1793                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1794                                 free_sections(sbi),
1795                                 free_segments(sbi),
1796                                 reserved_segments(sbi),
1797                                 prefree_segments(sbi));
1798
1799         up_write(&sbi->gc_lock);
1800
1801         put_gc_inode(&gc_list);
1802
1803         if (sync && !ret)
1804                 ret = sec_freed ? 0 : -EAGAIN;
1805         return ret;
1806 }
1807
1808 int __init f2fs_create_garbage_collection_cache(void)
1809 {
1810         victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1811                                         sizeof(struct victim_entry));
1812         if (!victim_entry_slab)
1813                 return -ENOMEM;
1814         return 0;
1815 }
1816
1817 void f2fs_destroy_garbage_collection_cache(void)
1818 {
1819         kmem_cache_destroy(victim_entry_slab);
1820 }
1821
1822 static void init_atgc_management(struct f2fs_sb_info *sbi)
1823 {
1824         struct atgc_management *am = &sbi->am;
1825
1826         if (test_opt(sbi, ATGC) &&
1827                 SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1828                 am->atgc_enabled = true;
1829
1830         am->root = RB_ROOT_CACHED;
1831         INIT_LIST_HEAD(&am->victim_list);
1832         am->victim_count = 0;
1833
1834         am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1835         am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1836         am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1837         am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1838 }
1839
1840 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1841 {
1842         DIRTY_I(sbi)->v_ops = &default_v_ops;
1843
1844         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1845
1846         /* give warm/cold data area from slower device */
1847         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1848                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1849                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1850
1851         init_atgc_management(sbi);
1852 }
1853
1854 static int free_segment_range(struct f2fs_sb_info *sbi,
1855                                 unsigned int secs, bool gc_only)
1856 {
1857         unsigned int segno, next_inuse, start, end;
1858         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1859         int gc_mode, gc_type;
1860         int err = 0;
1861         int type;
1862
1863         /* Force block allocation for GC */
1864         MAIN_SECS(sbi) -= secs;
1865         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1866         end = MAIN_SEGS(sbi) - 1;
1867
1868         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1869         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1870                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1871                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1872
1873         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1874                 if (sbi->next_victim_seg[gc_type] >= start)
1875                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1876         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1877
1878         /* Move out cursegs from the target range */
1879         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1880                 f2fs_allocate_segment_for_resize(sbi, type, start, end);
1881
1882         /* do GC to move out valid blocks in the range */
1883         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1884                 struct gc_inode_list gc_list = {
1885                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1886                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1887                 };
1888
1889                 do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1890                 put_gc_inode(&gc_list);
1891
1892                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1893                         err = -EAGAIN;
1894                         goto out;
1895                 }
1896                 if (fatal_signal_pending(current)) {
1897                         err = -ERESTARTSYS;
1898                         goto out;
1899                 }
1900         }
1901         if (gc_only)
1902                 goto out;
1903
1904         err = f2fs_write_checkpoint(sbi, &cpc);
1905         if (err)
1906                 goto out;
1907
1908         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1909         if (next_inuse <= end) {
1910                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1911                          next_inuse);
1912                 f2fs_bug_on(sbi, 1);
1913         }
1914 out:
1915         MAIN_SECS(sbi) += secs;
1916         return err;
1917 }
1918
1919 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1920 {
1921         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1922         int section_count;
1923         int segment_count;
1924         int segment_count_main;
1925         long long block_count;
1926         int segs = secs * sbi->segs_per_sec;
1927
1928         down_write(&sbi->sb_lock);
1929
1930         section_count = le32_to_cpu(raw_sb->section_count);
1931         segment_count = le32_to_cpu(raw_sb->segment_count);
1932         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1933         block_count = le64_to_cpu(raw_sb->block_count);
1934
1935         raw_sb->section_count = cpu_to_le32(section_count + secs);
1936         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1937         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1938         raw_sb->block_count = cpu_to_le64(block_count +
1939                                         (long long)segs * sbi->blocks_per_seg);
1940         if (f2fs_is_multi_device(sbi)) {
1941                 int last_dev = sbi->s_ndevs - 1;
1942                 int dev_segs =
1943                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1944
1945                 raw_sb->devs[last_dev].total_segments =
1946                                                 cpu_to_le32(dev_segs + segs);
1947         }
1948
1949         up_write(&sbi->sb_lock);
1950 }
1951
1952 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1953 {
1954         int segs = secs * sbi->segs_per_sec;
1955         long long blks = (long long)segs * sbi->blocks_per_seg;
1956         long long user_block_count =
1957                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1958
1959         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1960         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1961         MAIN_SECS(sbi) += secs;
1962         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1963         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1964         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1965
1966         if (f2fs_is_multi_device(sbi)) {
1967                 int last_dev = sbi->s_ndevs - 1;
1968
1969                 FDEV(last_dev).total_segments =
1970                                 (int)FDEV(last_dev).total_segments + segs;
1971                 FDEV(last_dev).end_blk =
1972                                 (long long)FDEV(last_dev).end_blk + blks;
1973 #ifdef CONFIG_BLK_DEV_ZONED
1974                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1975                                         (int)(blks >> sbi->log_blocks_per_blkz);
1976 #endif
1977         }
1978 }
1979
1980 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1981 {
1982         __u64 old_block_count, shrunk_blocks;
1983         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1984         unsigned int secs;
1985         int err = 0;
1986         __u32 rem;
1987
1988         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1989         if (block_count > old_block_count)
1990                 return -EINVAL;
1991
1992         if (f2fs_is_multi_device(sbi)) {
1993                 int last_dev = sbi->s_ndevs - 1;
1994                 __u64 last_segs = FDEV(last_dev).total_segments;
1995
1996                 if (block_count + last_segs * sbi->blocks_per_seg <=
1997                                                                 old_block_count)
1998                         return -EINVAL;
1999         }
2000
2001         /* new fs size should align to section size */
2002         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
2003         if (rem)
2004                 return -EINVAL;
2005
2006         if (block_count == old_block_count)
2007                 return 0;
2008
2009         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2010                 f2fs_err(sbi, "Should run fsck to repair first.");
2011                 return -EFSCORRUPTED;
2012         }
2013
2014         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2015                 f2fs_err(sbi, "Checkpoint should be enabled.");
2016                 return -EINVAL;
2017         }
2018
2019         shrunk_blocks = old_block_count - block_count;
2020         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2021
2022         /* stop other GC */
2023         if (!down_write_trylock(&sbi->gc_lock))
2024                 return -EAGAIN;
2025
2026         /* stop CP to protect MAIN_SEC in free_segment_range */
2027         f2fs_lock_op(sbi);
2028
2029         spin_lock(&sbi->stat_lock);
2030         if (shrunk_blocks + valid_user_blocks(sbi) +
2031                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2032                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2033                 err = -ENOSPC;
2034         spin_unlock(&sbi->stat_lock);
2035
2036         if (err)
2037                 goto out_unlock;
2038
2039         err = free_segment_range(sbi, secs, true);
2040
2041 out_unlock:
2042         f2fs_unlock_op(sbi);
2043         up_write(&sbi->gc_lock);
2044         if (err)
2045                 return err;
2046
2047         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2048
2049         freeze_super(sbi->sb);
2050         down_write(&sbi->gc_lock);
2051         down_write(&sbi->cp_global_sem);
2052
2053         spin_lock(&sbi->stat_lock);
2054         if (shrunk_blocks + valid_user_blocks(sbi) +
2055                 sbi->current_reserved_blocks + sbi->unusable_block_count +
2056                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2057                 err = -ENOSPC;
2058         else
2059                 sbi->user_block_count -= shrunk_blocks;
2060         spin_unlock(&sbi->stat_lock);
2061         if (err)
2062                 goto out_err;
2063
2064         err = free_segment_range(sbi, secs, false);
2065         if (err)
2066                 goto recover_out;
2067
2068         update_sb_metadata(sbi, -secs);
2069
2070         err = f2fs_commit_super(sbi, false);
2071         if (err) {
2072                 update_sb_metadata(sbi, secs);
2073                 goto recover_out;
2074         }
2075
2076         update_fs_metadata(sbi, -secs);
2077         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2078         set_sbi_flag(sbi, SBI_IS_DIRTY);
2079
2080         err = f2fs_write_checkpoint(sbi, &cpc);
2081         if (err) {
2082                 update_fs_metadata(sbi, secs);
2083                 update_sb_metadata(sbi, secs);
2084                 f2fs_commit_super(sbi, false);
2085         }
2086 recover_out:
2087         if (err) {
2088                 set_sbi_flag(sbi, SBI_NEED_FSCK);
2089                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2090
2091                 spin_lock(&sbi->stat_lock);
2092                 sbi->user_block_count += shrunk_blocks;
2093                 spin_unlock(&sbi->stat_lock);
2094         }
2095 out_err:
2096         up_write(&sbi->cp_global_sem);
2097         up_write(&sbi->gc_lock);
2098         thaw_super(sbi->sb);
2099         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2100         return err;
2101 }