linux/fs/f2fs/gc.c
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   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
  18#include "f2fs.h"
  19#include "node.h"
  20#include "segment.h"
  21#include "gc.h"
  22#include <trace/events/f2fs.h>
  23
  24static struct kmem_cache *victim_entry_slab;
  25
  26static unsigned int count_bits(const unsigned long *addr,
  27                                unsigned int offset, unsigned int len);
  28
  29static int gc_thread_func(void *data)
  30{
  31        struct f2fs_sb_info *sbi = data;
  32        struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  33        wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  34        unsigned int wait_ms;
  35
  36        wait_ms = gc_th->min_sleep_time;
  37
  38        set_freezable();
  39        do {
  40                bool sync_mode;
  41
  42                wait_event_interruptible_timeout(*wq,
  43                                kthread_should_stop() || freezing(current) ||
  44                                gc_th->gc_wake,
  45                                msecs_to_jiffies(wait_ms));
  46
  47                /* give it a try one time */
  48                if (gc_th->gc_wake)
  49                        gc_th->gc_wake = 0;
  50
  51                if (try_to_freeze()) {
  52                        stat_other_skip_bggc_count(sbi);
  53                        continue;
  54                }
  55                if (kthread_should_stop())
  56                        break;
  57
  58                if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  59                        increase_sleep_time(gc_th, &wait_ms);
  60                        stat_other_skip_bggc_count(sbi);
  61                        continue;
  62                }
  63
  64                if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  65                        f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  66                        f2fs_stop_checkpoint(sbi, false);
  67                }
  68
  69                if (!sb_start_write_trylock(sbi->sb)) {
  70                        stat_other_skip_bggc_count(sbi);
  71                        continue;
  72                }
  73
  74                /*
  75                 * [GC triggering condition]
  76                 * 0. GC is not conducted currently.
  77                 * 1. There are enough dirty segments.
  78                 * 2. IO subsystem is idle by checking the # of writeback pages.
  79                 * 3. IO subsystem is idle by checking the # of requests in
  80                 *    bdev's request list.
  81                 *
  82                 * Note) We have to avoid triggering GCs frequently.
  83                 * Because it is possible that some segments can be
  84                 * invalidated soon after by user update or deletion.
  85                 * So, I'd like to wait some time to collect dirty segments.
  86                 */
  87                if (sbi->gc_mode == GC_URGENT_HIGH) {
  88                        wait_ms = gc_th->urgent_sleep_time;
  89                        down_write(&sbi->gc_lock);
  90                        goto do_gc;
  91                }
  92
  93                if (!down_write_trylock(&sbi->gc_lock)) {
  94                        stat_other_skip_bggc_count(sbi);
  95                        goto next;
  96                }
  97
  98                if (!is_idle(sbi, GC_TIME)) {
  99                        increase_sleep_time(gc_th, &wait_ms);
 100                        up_write(&sbi->gc_lock);
 101                        stat_io_skip_bggc_count(sbi);
 102                        goto next;
 103                }
 104
 105                if (has_enough_invalid_blocks(sbi))
 106                        decrease_sleep_time(gc_th, &wait_ms);
 107                else
 108                        increase_sleep_time(gc_th, &wait_ms);
 109do_gc:
 110                stat_inc_bggc_count(sbi->stat_info);
 111
 112                sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 113
 114                /* if return value is not zero, no victim was selected */
 115                if (f2fs_gc(sbi, sync_mode, true, NULL_SEGNO))
 116                        wait_ms = gc_th->no_gc_sleep_time;
 117
 118                trace_f2fs_background_gc(sbi->sb, wait_ms,
 119                                prefree_segments(sbi), free_segments(sbi));
 120
 121                /* balancing f2fs's metadata periodically */
 122                f2fs_balance_fs_bg(sbi, true);
 123next:
 124                sb_end_write(sbi->sb);
 125
 126        } while (!kthread_should_stop());
 127        return 0;
 128}
 129
 130int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 131{
 132        struct f2fs_gc_kthread *gc_th;
 133        dev_t dev = sbi->sb->s_bdev->bd_dev;
 134        int err = 0;
 135
 136        gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 137        if (!gc_th) {
 138                err = -ENOMEM;
 139                goto out;
 140        }
 141
 142        gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 143        gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 144        gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 145        gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 146
 147        gc_th->gc_wake= 0;
 148
 149        sbi->gc_thread = gc_th;
 150        init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 151        sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 152                        "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 153        if (IS_ERR(gc_th->f2fs_gc_task)) {
 154                err = PTR_ERR(gc_th->f2fs_gc_task);
 155                kfree(gc_th);
 156                sbi->gc_thread = NULL;
 157        }
 158out:
 159        return err;
 160}
 161
 162void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 163{
 164        struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 165        if (!gc_th)
 166                return;
 167        kthread_stop(gc_th->f2fs_gc_task);
 168        kfree(gc_th);
 169        sbi->gc_thread = NULL;
 170}
 171
 172static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 173{
 174        int gc_mode;
 175
 176        if (gc_type == BG_GC) {
 177                if (sbi->am.atgc_enabled)
 178                        gc_mode = GC_AT;
 179                else
 180                        gc_mode = GC_CB;
 181        } else {
 182                gc_mode = GC_GREEDY;
 183        }
 184
 185        switch (sbi->gc_mode) {
 186        case GC_IDLE_CB:
 187                gc_mode = GC_CB;
 188                break;
 189        case GC_IDLE_GREEDY:
 190        case GC_URGENT_HIGH:
 191                gc_mode = GC_GREEDY;
 192                break;
 193        case GC_IDLE_AT:
 194                gc_mode = GC_AT;
 195                break;
 196        }
 197
 198        return gc_mode;
 199}
 200
 201static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 202                        int type, struct victim_sel_policy *p)
 203{
 204        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 205
 206        if (p->alloc_mode == SSR) {
 207                p->gc_mode = GC_GREEDY;
 208                p->dirty_bitmap = dirty_i->dirty_segmap[type];
 209                p->max_search = dirty_i->nr_dirty[type];
 210                p->ofs_unit = 1;
 211        } else if (p->alloc_mode == AT_SSR) {
 212                p->gc_mode = GC_GREEDY;
 213                p->dirty_bitmap = dirty_i->dirty_segmap[type];
 214                p->max_search = dirty_i->nr_dirty[type];
 215                p->ofs_unit = 1;
 216        } else {
 217                p->gc_mode = select_gc_type(sbi, gc_type);
 218                p->ofs_unit = sbi->segs_per_sec;
 219                if (__is_large_section(sbi)) {
 220                        p->dirty_bitmap = dirty_i->dirty_secmap;
 221                        p->max_search = count_bits(p->dirty_bitmap,
 222                                                0, MAIN_SECS(sbi));
 223                } else {
 224                        p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 225                        p->max_search = dirty_i->nr_dirty[DIRTY];
 226                }
 227        }
 228
 229        /*
 230         * adjust candidates range, should select all dirty segments for
 231         * foreground GC and urgent GC cases.
 232         */
 233        if (gc_type != FG_GC &&
 234                        (sbi->gc_mode != GC_URGENT_HIGH) &&
 235                        (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 236                        p->max_search > sbi->max_victim_search)
 237                p->max_search = sbi->max_victim_search;
 238
 239        /* let's select beginning hot/small space first in no_heap mode*/
 240        if (test_opt(sbi, NOHEAP) &&
 241                (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 242                p->offset = 0;
 243        else
 244                p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 245}
 246
 247static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 248                                struct victim_sel_policy *p)
 249{
 250        /* SSR allocates in a segment unit */
 251        if (p->alloc_mode == SSR)
 252                return sbi->blocks_per_seg;
 253        else if (p->alloc_mode == AT_SSR)
 254                return UINT_MAX;
 255
 256        /* LFS */
 257        if (p->gc_mode == GC_GREEDY)
 258                return 2 * sbi->blocks_per_seg * p->ofs_unit;
 259        else if (p->gc_mode == GC_CB)
 260                return UINT_MAX;
 261        else if (p->gc_mode == GC_AT)
 262                return UINT_MAX;
 263        else /* No other gc_mode */
 264                return 0;
 265}
 266
 267static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 268{
 269        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 270        unsigned int secno;
 271
 272        /*
 273         * If the gc_type is FG_GC, we can select victim segments
 274         * selected by background GC before.
 275         * Those segments guarantee they have small valid blocks.
 276         */
 277        for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 278                if (sec_usage_check(sbi, secno))
 279                        continue;
 280                clear_bit(secno, dirty_i->victim_secmap);
 281                return GET_SEG_FROM_SEC(sbi, secno);
 282        }
 283        return NULL_SEGNO;
 284}
 285
 286static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 287{
 288        struct sit_info *sit_i = SIT_I(sbi);
 289        unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 290        unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 291        unsigned long long mtime = 0;
 292        unsigned int vblocks;
 293        unsigned char age = 0;
 294        unsigned char u;
 295        unsigned int i;
 296        unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 297
 298        for (i = 0; i < usable_segs_per_sec; i++)
 299                mtime += get_seg_entry(sbi, start + i)->mtime;
 300        vblocks = get_valid_blocks(sbi, segno, true);
 301
 302        mtime = div_u64(mtime, usable_segs_per_sec);
 303        vblocks = div_u64(vblocks, usable_segs_per_sec);
 304
 305        u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 306
 307        /* Handle if the system time has changed by the user */
 308        if (mtime < sit_i->min_mtime)
 309                sit_i->min_mtime = mtime;
 310        if (mtime > sit_i->max_mtime)
 311                sit_i->max_mtime = mtime;
 312        if (sit_i->max_mtime != sit_i->min_mtime)
 313                age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 314                                sit_i->max_mtime - sit_i->min_mtime);
 315
 316        return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 317}
 318
 319static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 320                        unsigned int segno, struct victim_sel_policy *p)
 321{
 322        if (p->alloc_mode == SSR)
 323                return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 324
 325        /* alloc_mode == LFS */
 326        if (p->gc_mode == GC_GREEDY)
 327                return get_valid_blocks(sbi, segno, true);
 328        else if (p->gc_mode == GC_CB)
 329                return get_cb_cost(sbi, segno);
 330
 331        f2fs_bug_on(sbi, 1);
 332        return 0;
 333}
 334
 335static unsigned int count_bits(const unsigned long *addr,
 336                                unsigned int offset, unsigned int len)
 337{
 338        unsigned int end = offset + len, sum = 0;
 339
 340        while (offset < end) {
 341                if (test_bit(offset++, addr))
 342                        ++sum;
 343        }
 344        return sum;
 345}
 346
 347static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 348                                unsigned long long mtime, unsigned int segno,
 349                                struct rb_node *parent, struct rb_node **p,
 350                                bool left_most)
 351{
 352        struct atgc_management *am = &sbi->am;
 353        struct victim_entry *ve;
 354
 355        ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS);
 356
 357        ve->mtime = mtime;
 358        ve->segno = segno;
 359
 360        rb_link_node(&ve->rb_node, parent, p);
 361        rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 362
 363        list_add_tail(&ve->list, &am->victim_list);
 364
 365        am->victim_count++;
 366
 367        return ve;
 368}
 369
 370static void insert_victim_entry(struct f2fs_sb_info *sbi,
 371                                unsigned long long mtime, unsigned int segno)
 372{
 373        struct atgc_management *am = &sbi->am;
 374        struct rb_node **p;
 375        struct rb_node *parent = NULL;
 376        bool left_most = true;
 377
 378        p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 379        attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 380}
 381
 382static void add_victim_entry(struct f2fs_sb_info *sbi,
 383                                struct victim_sel_policy *p, unsigned int segno)
 384{
 385        struct sit_info *sit_i = SIT_I(sbi);
 386        unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 387        unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 388        unsigned long long mtime = 0;
 389        unsigned int i;
 390
 391        if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 392                if (p->gc_mode == GC_AT &&
 393                        get_valid_blocks(sbi, segno, true) == 0)
 394                        return;
 395
 396                if (p->alloc_mode == AT_SSR &&
 397                        get_seg_entry(sbi, segno)->ckpt_valid_blocks == 0)
 398                        return;
 399        }
 400
 401        for (i = 0; i < sbi->segs_per_sec; i++)
 402                mtime += get_seg_entry(sbi, start + i)->mtime;
 403        mtime = div_u64(mtime, sbi->segs_per_sec);
 404
 405        /* Handle if the system time has changed by the user */
 406        if (mtime < sit_i->min_mtime)
 407                sit_i->min_mtime = mtime;
 408        if (mtime > sit_i->max_mtime)
 409                sit_i->max_mtime = mtime;
 410        if (mtime < sit_i->dirty_min_mtime)
 411                sit_i->dirty_min_mtime = mtime;
 412        if (mtime > sit_i->dirty_max_mtime)
 413                sit_i->dirty_max_mtime = mtime;
 414
 415        /* don't choose young section as candidate */
 416        if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 417                return;
 418
 419        insert_victim_entry(sbi, mtime, segno);
 420}
 421
 422static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 423                                                struct victim_sel_policy *p)
 424{
 425        struct atgc_management *am = &sbi->am;
 426        struct rb_node *parent = NULL;
 427        bool left_most;
 428
 429        f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 430
 431        return parent;
 432}
 433
 434static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 435                                                struct victim_sel_policy *p)
 436{
 437        struct sit_info *sit_i = SIT_I(sbi);
 438        struct atgc_management *am = &sbi->am;
 439        struct rb_root_cached *root = &am->root;
 440        struct rb_node *node;
 441        struct rb_entry *re;
 442        struct victim_entry *ve;
 443        unsigned long long total_time;
 444        unsigned long long age, u, accu;
 445        unsigned long long max_mtime = sit_i->dirty_max_mtime;
 446        unsigned long long min_mtime = sit_i->dirty_min_mtime;
 447        unsigned int sec_blocks = BLKS_PER_SEC(sbi);
 448        unsigned int vblocks;
 449        unsigned int dirty_threshold = max(am->max_candidate_count,
 450                                        am->candidate_ratio *
 451                                        am->victim_count / 100);
 452        unsigned int age_weight = am->age_weight;
 453        unsigned int cost;
 454        unsigned int iter = 0;
 455
 456        if (max_mtime < min_mtime)
 457                return;
 458
 459        max_mtime += 1;
 460        total_time = max_mtime - min_mtime;
 461
 462        accu = div64_u64(ULLONG_MAX, total_time);
 463        accu = min_t(unsigned long long, div_u64(accu, 100),
 464                                        DEFAULT_ACCURACY_CLASS);
 465
 466        node = rb_first_cached(root);
 467next:
 468        re = rb_entry_safe(node, struct rb_entry, rb_node);
 469        if (!re)
 470                return;
 471
 472        ve = (struct victim_entry *)re;
 473
 474        if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 475                goto skip;
 476
 477        /* age = 10000 * x% * 60 */
 478        age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 479                                                                age_weight;
 480
 481        vblocks = get_valid_blocks(sbi, ve->segno, true);
 482        f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 483
 484        /* u = 10000 * x% * 40 */
 485        u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 486                                                        (100 - age_weight);
 487
 488        f2fs_bug_on(sbi, age + u >= UINT_MAX);
 489
 490        cost = UINT_MAX - (age + u);
 491        iter++;
 492
 493        if (cost < p->min_cost ||
 494                        (cost == p->min_cost && age > p->oldest_age)) {
 495                p->min_cost = cost;
 496                p->oldest_age = age;
 497                p->min_segno = ve->segno;
 498        }
 499skip:
 500        if (iter < dirty_threshold) {
 501                node = rb_next(node);
 502                goto next;
 503        }
 504}
 505
 506/*
 507 * select candidates around source section in range of
 508 * [target - dirty_threshold, target + dirty_threshold]
 509 */
 510static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 511                                                struct victim_sel_policy *p)
 512{
 513        struct sit_info *sit_i = SIT_I(sbi);
 514        struct atgc_management *am = &sbi->am;
 515        struct rb_node *node;
 516        struct rb_entry *re;
 517        struct victim_entry *ve;
 518        unsigned long long age;
 519        unsigned long long max_mtime = sit_i->dirty_max_mtime;
 520        unsigned long long min_mtime = sit_i->dirty_min_mtime;
 521        unsigned int seg_blocks = sbi->blocks_per_seg;
 522        unsigned int vblocks;
 523        unsigned int dirty_threshold = max(am->max_candidate_count,
 524                                        am->candidate_ratio *
 525                                        am->victim_count / 100);
 526        unsigned int cost;
 527        unsigned int iter = 0;
 528        int stage = 0;
 529
 530        if (max_mtime < min_mtime)
 531                return;
 532        max_mtime += 1;
 533next_stage:
 534        node = lookup_central_victim(sbi, p);
 535next_node:
 536        re = rb_entry_safe(node, struct rb_entry, rb_node);
 537        if (!re) {
 538                if (stage == 0)
 539                        goto skip_stage;
 540                return;
 541        }
 542
 543        ve = (struct victim_entry *)re;
 544
 545        if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 546                goto skip_node;
 547
 548        age = max_mtime - ve->mtime;
 549
 550        vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 551        f2fs_bug_on(sbi, !vblocks);
 552
 553        /* rare case */
 554        if (vblocks == seg_blocks)
 555                goto skip_node;
 556
 557        iter++;
 558
 559        age = max_mtime - abs(p->age - age);
 560        cost = UINT_MAX - vblocks;
 561
 562        if (cost < p->min_cost ||
 563                        (cost == p->min_cost && age > p->oldest_age)) {
 564                p->min_cost = cost;
 565                p->oldest_age = age;
 566                p->min_segno = ve->segno;
 567        }
 568skip_node:
 569        if (iter < dirty_threshold) {
 570                if (stage == 0)
 571                        node = rb_prev(node);
 572                else if (stage == 1)
 573                        node = rb_next(node);
 574                goto next_node;
 575        }
 576skip_stage:
 577        if (stage < 1) {
 578                stage++;
 579                iter = 0;
 580                goto next_stage;
 581        }
 582}
 583static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 584                                                struct victim_sel_policy *p)
 585{
 586        f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 587                                                &sbi->am.root, true));
 588
 589        if (p->gc_mode == GC_AT)
 590                atgc_lookup_victim(sbi, p);
 591        else if (p->alloc_mode == AT_SSR)
 592                atssr_lookup_victim(sbi, p);
 593        else
 594                f2fs_bug_on(sbi, 1);
 595}
 596
 597static void release_victim_entry(struct f2fs_sb_info *sbi)
 598{
 599        struct atgc_management *am = &sbi->am;
 600        struct victim_entry *ve, *tmp;
 601
 602        list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 603                list_del(&ve->list);
 604                kmem_cache_free(victim_entry_slab, ve);
 605                am->victim_count--;
 606        }
 607
 608        am->root = RB_ROOT_CACHED;
 609
 610        f2fs_bug_on(sbi, am->victim_count);
 611        f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 612}
 613
 614/*
 615 * This function is called from two paths.
 616 * One is garbage collection and the other is SSR segment selection.
 617 * When it is called during GC, it just gets a victim segment
 618 * and it does not remove it from dirty seglist.
 619 * When it is called from SSR segment selection, it finds a segment
 620 * which has minimum valid blocks and removes it from dirty seglist.
 621 */
 622static int get_victim_by_default(struct f2fs_sb_info *sbi,
 623                        unsigned int *result, int gc_type, int type,
 624                        char alloc_mode, unsigned long long age)
 625{
 626        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 627        struct sit_info *sm = SIT_I(sbi);
 628        struct victim_sel_policy p;
 629        unsigned int secno, last_victim;
 630        unsigned int last_segment;
 631        unsigned int nsearched;
 632        bool is_atgc;
 633        int ret = 0;
 634
 635        mutex_lock(&dirty_i->seglist_lock);
 636        last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 637
 638        p.alloc_mode = alloc_mode;
 639        p.age = age;
 640        p.age_threshold = sbi->am.age_threshold;
 641
 642retry:
 643        select_policy(sbi, gc_type, type, &p);
 644        p.min_segno = NULL_SEGNO;
 645        p.oldest_age = 0;
 646        p.min_cost = get_max_cost(sbi, &p);
 647
 648        is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 649        nsearched = 0;
 650
 651        if (is_atgc)
 652                SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 653
 654        if (*result != NULL_SEGNO) {
 655                if (!get_valid_blocks(sbi, *result, false)) {
 656                        ret = -ENODATA;
 657                        goto out;
 658                }
 659
 660                if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 661                        ret = -EBUSY;
 662                else
 663                        p.min_segno = *result;
 664                goto out;
 665        }
 666
 667        ret = -ENODATA;
 668        if (p.max_search == 0)
 669                goto out;
 670
 671        if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 672                if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 673                        p.min_segno = sbi->next_victim_seg[BG_GC];
 674                        *result = p.min_segno;
 675                        sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 676                        goto got_result;
 677                }
 678                if (gc_type == FG_GC &&
 679                                sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 680                        p.min_segno = sbi->next_victim_seg[FG_GC];
 681                        *result = p.min_segno;
 682                        sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 683                        goto got_result;
 684                }
 685        }
 686
 687        last_victim = sm->last_victim[p.gc_mode];
 688        if (p.alloc_mode == LFS && gc_type == FG_GC) {
 689                p.min_segno = check_bg_victims(sbi);
 690                if (p.min_segno != NULL_SEGNO)
 691                        goto got_it;
 692        }
 693
 694        while (1) {
 695                unsigned long cost, *dirty_bitmap;
 696                unsigned int unit_no, segno;
 697
 698                dirty_bitmap = p.dirty_bitmap;
 699                unit_no = find_next_bit(dirty_bitmap,
 700                                last_segment / p.ofs_unit,
 701                                p.offset / p.ofs_unit);
 702                segno = unit_no * p.ofs_unit;
 703                if (segno >= last_segment) {
 704                        if (sm->last_victim[p.gc_mode]) {
 705                                last_segment =
 706                                        sm->last_victim[p.gc_mode];
 707                                sm->last_victim[p.gc_mode] = 0;
 708                                p.offset = 0;
 709                                continue;
 710                        }
 711                        break;
 712                }
 713
 714                p.offset = segno + p.ofs_unit;
 715                nsearched++;
 716
 717#ifdef CONFIG_F2FS_CHECK_FS
 718                /*
 719                 * skip selecting the invalid segno (that is failed due to block
 720                 * validity check failure during GC) to avoid endless GC loop in
 721                 * such cases.
 722                 */
 723                if (test_bit(segno, sm->invalid_segmap))
 724                        goto next;
 725#endif
 726
 727                secno = GET_SEC_FROM_SEG(sbi, segno);
 728
 729                if (sec_usage_check(sbi, secno))
 730                        goto next;
 731                /* Don't touch checkpointed data */
 732                if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
 733                                        get_ckpt_valid_blocks(sbi, segno) &&
 734                                        p.alloc_mode == LFS))
 735                        goto next;
 736                if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 737                        goto next;
 738
 739                if (is_atgc) {
 740                        add_victim_entry(sbi, &p, segno);
 741                        goto next;
 742                }
 743
 744                cost = get_gc_cost(sbi, segno, &p);
 745
 746                if (p.min_cost > cost) {
 747                        p.min_segno = segno;
 748                        p.min_cost = cost;
 749                }
 750next:
 751                if (nsearched >= p.max_search) {
 752                        if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 753                                sm->last_victim[p.gc_mode] =
 754                                        last_victim + p.ofs_unit;
 755                        else
 756                                sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 757                        sm->last_victim[p.gc_mode] %=
 758                                (MAIN_SECS(sbi) * sbi->segs_per_sec);
 759                        break;
 760                }
 761        }
 762
 763        /* get victim for GC_AT/AT_SSR */
 764        if (is_atgc) {
 765                lookup_victim_by_age(sbi, &p);
 766                release_victim_entry(sbi);
 767        }
 768
 769        if (is_atgc && p.min_segno == NULL_SEGNO &&
 770                        sm->elapsed_time < p.age_threshold) {
 771                p.age_threshold = 0;
 772                goto retry;
 773        }
 774
 775        if (p.min_segno != NULL_SEGNO) {
 776got_it:
 777                *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 778got_result:
 779                if (p.alloc_mode == LFS) {
 780                        secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 781                        if (gc_type == FG_GC)
 782                                sbi->cur_victim_sec = secno;
 783                        else
 784                                set_bit(secno, dirty_i->victim_secmap);
 785                }
 786                ret = 0;
 787
 788        }
 789out:
 790        if (p.min_segno != NULL_SEGNO)
 791                trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 792                                sbi->cur_victim_sec,
 793                                prefree_segments(sbi), free_segments(sbi));
 794        mutex_unlock(&dirty_i->seglist_lock);
 795
 796        return ret;
 797}
 798
 799static const struct victim_selection default_v_ops = {
 800        .get_victim = get_victim_by_default,
 801};
 802
 803static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 804{
 805        struct inode_entry *ie;
 806
 807        ie = radix_tree_lookup(&gc_list->iroot, ino);
 808        if (ie)
 809                return ie->inode;
 810        return NULL;
 811}
 812
 813static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 814{
 815        struct inode_entry *new_ie;
 816
 817        if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 818                iput(inode);
 819                return;
 820        }
 821        new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 822        new_ie->inode = inode;
 823
 824        f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 825        list_add_tail(&new_ie->list, &gc_list->ilist);
 826}
 827
 828static void put_gc_inode(struct gc_inode_list *gc_list)
 829{
 830        struct inode_entry *ie, *next_ie;
 831        list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 832                radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 833                iput(ie->inode);
 834                list_del(&ie->list);
 835                kmem_cache_free(f2fs_inode_entry_slab, ie);
 836        }
 837}
 838
 839static int check_valid_map(struct f2fs_sb_info *sbi,
 840                                unsigned int segno, int offset)
 841{
 842        struct sit_info *sit_i = SIT_I(sbi);
 843        struct seg_entry *sentry;
 844        int ret;
 845
 846        down_read(&sit_i->sentry_lock);
 847        sentry = get_seg_entry(sbi, segno);
 848        ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 849        up_read(&sit_i->sentry_lock);
 850        return ret;
 851}
 852
 853/*
 854 * This function compares node address got in summary with that in NAT.
 855 * On validity, copy that node with cold status, otherwise (invalid node)
 856 * ignore that.
 857 */
 858static int gc_node_segment(struct f2fs_sb_info *sbi,
 859                struct f2fs_summary *sum, unsigned int segno, int gc_type)
 860{
 861        struct f2fs_summary *entry;
 862        block_t start_addr;
 863        int off;
 864        int phase = 0;
 865        bool fggc = (gc_type == FG_GC);
 866        int submitted = 0;
 867        unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 868
 869        start_addr = START_BLOCK(sbi, segno);
 870
 871next_step:
 872        entry = sum;
 873
 874        if (fggc && phase == 2)
 875                atomic_inc(&sbi->wb_sync_req[NODE]);
 876
 877        for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 878                nid_t nid = le32_to_cpu(entry->nid);
 879                struct page *node_page;
 880                struct node_info ni;
 881                int err;
 882
 883                /* stop BG_GC if there is not enough free sections. */
 884                if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 885                        return submitted;
 886
 887                if (check_valid_map(sbi, segno, off) == 0)
 888                        continue;
 889
 890                if (phase == 0) {
 891                        f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 892                                                        META_NAT, true);
 893                        continue;
 894                }
 895
 896                if (phase == 1) {
 897                        f2fs_ra_node_page(sbi, nid);
 898                        continue;
 899                }
 900
 901                /* phase == 2 */
 902                node_page = f2fs_get_node_page(sbi, nid);
 903                if (IS_ERR(node_page))
 904                        continue;
 905
 906                /* block may become invalid during f2fs_get_node_page */
 907                if (check_valid_map(sbi, segno, off) == 0) {
 908                        f2fs_put_page(node_page, 1);
 909                        continue;
 910                }
 911
 912                if (f2fs_get_node_info(sbi, nid, &ni)) {
 913                        f2fs_put_page(node_page, 1);
 914                        continue;
 915                }
 916
 917                if (ni.blk_addr != start_addr + off) {
 918                        f2fs_put_page(node_page, 1);
 919                        continue;
 920                }
 921
 922                err = f2fs_move_node_page(node_page, gc_type);
 923                if (!err && gc_type == FG_GC)
 924                        submitted++;
 925                stat_inc_node_blk_count(sbi, 1, gc_type);
 926        }
 927
 928        if (++phase < 3)
 929                goto next_step;
 930
 931        if (fggc)
 932                atomic_dec(&sbi->wb_sync_req[NODE]);
 933        return submitted;
 934}
 935
 936/*
 937 * Calculate start block index indicating the given node offset.
 938 * Be careful, caller should give this node offset only indicating direct node
 939 * blocks. If any node offsets, which point the other types of node blocks such
 940 * as indirect or double indirect node blocks, are given, it must be a caller's
 941 * bug.
 942 */
 943block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 944{
 945        unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 946        unsigned int bidx;
 947
 948        if (node_ofs == 0)
 949                return 0;
 950
 951        if (node_ofs <= 2) {
 952                bidx = node_ofs - 1;
 953        } else if (node_ofs <= indirect_blks) {
 954                int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 955                bidx = node_ofs - 2 - dec;
 956        } else {
 957                int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 958                bidx = node_ofs - 5 - dec;
 959        }
 960        return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
 961}
 962
 963static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 964                struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 965{
 966        struct page *node_page;
 967        nid_t nid;
 968        unsigned int ofs_in_node;
 969        block_t source_blkaddr;
 970
 971        nid = le32_to_cpu(sum->nid);
 972        ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 973
 974        node_page = f2fs_get_node_page(sbi, nid);
 975        if (IS_ERR(node_page))
 976                return false;
 977
 978        if (f2fs_get_node_info(sbi, nid, dni)) {
 979                f2fs_put_page(node_page, 1);
 980                return false;
 981        }
 982
 983        if (sum->version != dni->version) {
 984                f2fs_warn(sbi, "%s: valid data with mismatched node version.",
 985                          __func__);
 986                set_sbi_flag(sbi, SBI_NEED_FSCK);
 987        }
 988
 989        *nofs = ofs_of_node(node_page);
 990        source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
 991        f2fs_put_page(node_page, 1);
 992
 993        if (source_blkaddr != blkaddr) {
 994#ifdef CONFIG_F2FS_CHECK_FS
 995                unsigned int segno = GET_SEGNO(sbi, blkaddr);
 996                unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 997
 998                if (unlikely(check_valid_map(sbi, segno, offset))) {
 999                        if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1000                                f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n",
1001                                                blkaddr, source_blkaddr, segno);
1002                                f2fs_bug_on(sbi, 1);
1003                        }
1004                }
1005#endif
1006                return false;
1007        }
1008        return true;
1009}
1010
1011static int ra_data_block(struct inode *inode, pgoff_t index)
1012{
1013        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1014        struct address_space *mapping = inode->i_mapping;
1015        struct dnode_of_data dn;
1016        struct page *page;
1017        struct extent_info ei = {0, 0, 0};
1018        struct f2fs_io_info fio = {
1019                .sbi = sbi,
1020                .ino = inode->i_ino,
1021                .type = DATA,
1022                .temp = COLD,
1023                .op = REQ_OP_READ,
1024                .op_flags = 0,
1025                .encrypted_page = NULL,
1026                .in_list = false,
1027                .retry = false,
1028        };
1029        int err;
1030
1031        page = f2fs_grab_cache_page(mapping, index, true);
1032        if (!page)
1033                return -ENOMEM;
1034
1035        if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1036                dn.data_blkaddr = ei.blk + index - ei.fofs;
1037                if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1038                                                DATA_GENERIC_ENHANCE_READ))) {
1039                        err = -EFSCORRUPTED;
1040                        goto put_page;
1041                }
1042                goto got_it;
1043        }
1044
1045        set_new_dnode(&dn, inode, NULL, NULL, 0);
1046        err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1047        if (err)
1048                goto put_page;
1049        f2fs_put_dnode(&dn);
1050
1051        if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1052                err = -ENOENT;
1053                goto put_page;
1054        }
1055        if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1056                                                DATA_GENERIC_ENHANCE))) {
1057                err = -EFSCORRUPTED;
1058                goto put_page;
1059        }
1060got_it:
1061        /* read page */
1062        fio.page = page;
1063        fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1064
1065        /*
1066         * don't cache encrypted data into meta inode until previous dirty
1067         * data were writebacked to avoid racing between GC and flush.
1068         */
1069        f2fs_wait_on_page_writeback(page, DATA, true, true);
1070
1071        f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1072
1073        fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1074                                        dn.data_blkaddr,
1075                                        FGP_LOCK | FGP_CREAT, GFP_NOFS);
1076        if (!fio.encrypted_page) {
1077                err = -ENOMEM;
1078                goto put_page;
1079        }
1080
1081        err = f2fs_submit_page_bio(&fio);
1082        if (err)
1083                goto put_encrypted_page;
1084        f2fs_put_page(fio.encrypted_page, 0);
1085        f2fs_put_page(page, 1);
1086
1087        f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1088        f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1089
1090        return 0;
1091put_encrypted_page:
1092        f2fs_put_page(fio.encrypted_page, 1);
1093put_page:
1094        f2fs_put_page(page, 1);
1095        return err;
1096}
1097
1098/*
1099 * Move data block via META_MAPPING while keeping locked data page.
1100 * This can be used to move blocks, aka LBAs, directly on disk.
1101 */
1102static int move_data_block(struct inode *inode, block_t bidx,
1103                                int gc_type, unsigned int segno, int off)
1104{
1105        struct f2fs_io_info fio = {
1106                .sbi = F2FS_I_SB(inode),
1107                .ino = inode->i_ino,
1108                .type = DATA,
1109                .temp = COLD,
1110                .op = REQ_OP_READ,
1111                .op_flags = 0,
1112                .encrypted_page = NULL,
1113                .in_list = false,
1114                .retry = false,
1115        };
1116        struct dnode_of_data dn;
1117        struct f2fs_summary sum;
1118        struct node_info ni;
1119        struct page *page, *mpage;
1120        block_t newaddr;
1121        int err = 0;
1122        bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1123        int type = fio.sbi->am.atgc_enabled ?
1124                                CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1125
1126        /* do not read out */
1127        page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1128        if (!page)
1129                return -ENOMEM;
1130
1131        if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1132                err = -ENOENT;
1133                goto out;
1134        }
1135
1136        if (f2fs_is_atomic_file(inode)) {
1137                F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1138                F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1139                err = -EAGAIN;
1140                goto out;
1141        }
1142
1143        if (f2fs_is_pinned_file(inode)) {
1144                f2fs_pin_file_control(inode, true);
1145                err = -EAGAIN;
1146                goto out;
1147        }
1148
1149        set_new_dnode(&dn, inode, NULL, NULL, 0);
1150        err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1151        if (err)
1152                goto out;
1153
1154        if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1155                ClearPageUptodate(page);
1156                err = -ENOENT;
1157                goto put_out;
1158        }
1159
1160        /*
1161         * don't cache encrypted data into meta inode until previous dirty
1162         * data were writebacked to avoid racing between GC and flush.
1163         */
1164        f2fs_wait_on_page_writeback(page, DATA, true, true);
1165
1166        f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1167
1168        err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
1169        if (err)
1170                goto put_out;
1171
1172        set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1173
1174        /* read page */
1175        fio.page = page;
1176        fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1177
1178        if (lfs_mode)
1179                down_write(&fio.sbi->io_order_lock);
1180
1181        mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1182                                        fio.old_blkaddr, false);
1183        if (!mpage) {
1184                err = -ENOMEM;
1185                goto up_out;
1186        }
1187
1188        fio.encrypted_page = mpage;
1189
1190        /* read source block in mpage */
1191        if (!PageUptodate(mpage)) {
1192                err = f2fs_submit_page_bio(&fio);
1193                if (err) {
1194                        f2fs_put_page(mpage, 1);
1195                        goto up_out;
1196                }
1197
1198                f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1199                f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1200
1201                lock_page(mpage);
1202                if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1203                                                !PageUptodate(mpage))) {
1204                        err = -EIO;
1205                        f2fs_put_page(mpage, 1);
1206                        goto up_out;
1207                }
1208        }
1209
1210        f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1211                                &sum, type, NULL);
1212
1213        fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1214                                newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1215        if (!fio.encrypted_page) {
1216                err = -ENOMEM;
1217                f2fs_put_page(mpage, 1);
1218                goto recover_block;
1219        }
1220
1221        /* write target block */
1222        f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1223        memcpy(page_address(fio.encrypted_page),
1224                                page_address(mpage), PAGE_SIZE);
1225        f2fs_put_page(mpage, 1);
1226        invalidate_mapping_pages(META_MAPPING(fio.sbi),
1227                                fio.old_blkaddr, fio.old_blkaddr);
1228
1229        set_page_dirty(fio.encrypted_page);
1230        if (clear_page_dirty_for_io(fio.encrypted_page))
1231                dec_page_count(fio.sbi, F2FS_DIRTY_META);
1232
1233        set_page_writeback(fio.encrypted_page);
1234        ClearPageError(page);
1235
1236        /* allocate block address */
1237        f2fs_wait_on_page_writeback(dn.node_page, NODE, true, true);
1238
1239        fio.op = REQ_OP_WRITE;
1240        fio.op_flags = REQ_SYNC;
1241        fio.new_blkaddr = newaddr;
1242        f2fs_submit_page_write(&fio);
1243        if (fio.retry) {
1244                err = -EAGAIN;
1245                if (PageWriteback(fio.encrypted_page))
1246                        end_page_writeback(fio.encrypted_page);
1247                goto put_page_out;
1248        }
1249
1250        f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1251
1252        f2fs_update_data_blkaddr(&dn, newaddr);
1253        set_inode_flag(inode, FI_APPEND_WRITE);
1254        if (page->index == 0)
1255                set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1256put_page_out:
1257        f2fs_put_page(fio.encrypted_page, 1);
1258recover_block:
1259        if (err)
1260                f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1261                                                        true, true, true);
1262up_out:
1263        if (lfs_mode)
1264                up_write(&fio.sbi->io_order_lock);
1265put_out:
1266        f2fs_put_dnode(&dn);
1267out:
1268        f2fs_put_page(page, 1);
1269        return err;
1270}
1271
1272static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1273                                                        unsigned int segno, int off)
1274{
1275        struct page *page;
1276        int err = 0;
1277
1278        page = f2fs_get_lock_data_page(inode, bidx, true);
1279        if (IS_ERR(page))
1280                return PTR_ERR(page);
1281
1282        if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1283                err = -ENOENT;
1284                goto out;
1285        }
1286
1287        if (f2fs_is_atomic_file(inode)) {
1288                F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1289                F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1290                err = -EAGAIN;
1291                goto out;
1292        }
1293        if (f2fs_is_pinned_file(inode)) {
1294                if (gc_type == FG_GC)
1295                        f2fs_pin_file_control(inode, true);
1296                err = -EAGAIN;
1297                goto out;
1298        }
1299
1300        if (gc_type == BG_GC) {
1301                if (PageWriteback(page)) {
1302                        err = -EAGAIN;
1303                        goto out;
1304                }
1305                set_page_dirty(page);
1306                set_cold_data(page);
1307        } else {
1308                struct f2fs_io_info fio = {
1309                        .sbi = F2FS_I_SB(inode),
1310                        .ino = inode->i_ino,
1311                        .type = DATA,
1312                        .temp = COLD,
1313                        .op = REQ_OP_WRITE,
1314                        .op_flags = REQ_SYNC,
1315                        .old_blkaddr = NULL_ADDR,
1316                        .page = page,
1317                        .encrypted_page = NULL,
1318                        .need_lock = LOCK_REQ,
1319                        .io_type = FS_GC_DATA_IO,
1320                };
1321                bool is_dirty = PageDirty(page);
1322
1323retry:
1324                f2fs_wait_on_page_writeback(page, DATA, true, true);
1325
1326                set_page_dirty(page);
1327                if (clear_page_dirty_for_io(page)) {
1328                        inode_dec_dirty_pages(inode);
1329                        f2fs_remove_dirty_inode(inode);
1330                }
1331
1332                set_cold_data(page);
1333
1334                err = f2fs_do_write_data_page(&fio);
1335                if (err) {
1336                        clear_cold_data(page);
1337                        if (err == -ENOMEM) {
1338                                congestion_wait(BLK_RW_ASYNC,
1339                                                DEFAULT_IO_TIMEOUT);
1340                                goto retry;
1341                        }
1342                        if (is_dirty)
1343                                set_page_dirty(page);
1344                }
1345        }
1346out:
1347        f2fs_put_page(page, 1);
1348        return err;
1349}
1350
1351/*
1352 * This function tries to get parent node of victim data block, and identifies
1353 * data block validity. If the block is valid, copy that with cold status and
1354 * modify parent node.
1355 * If the parent node is not valid or the data block address is different,
1356 * the victim data block is ignored.
1357 */
1358static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1359                struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
1360{
1361        struct super_block *sb = sbi->sb;
1362        struct f2fs_summary *entry;
1363        block_t start_addr;
1364        int off;
1365        int phase = 0;
1366        int submitted = 0;
1367        unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1368
1369        start_addr = START_BLOCK(sbi, segno);
1370
1371next_step:
1372        entry = sum;
1373
1374        for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1375                struct page *data_page;
1376                struct inode *inode;
1377                struct node_info dni; /* dnode info for the data */
1378                unsigned int ofs_in_node, nofs;
1379                block_t start_bidx;
1380                nid_t nid = le32_to_cpu(entry->nid);
1381
1382                /*
1383                 * stop BG_GC if there is not enough free sections.
1384                 * Or, stop GC if the segment becomes fully valid caused by
1385                 * race condition along with SSR block allocation.
1386                 */
1387                if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1388                                get_valid_blocks(sbi, segno, true) ==
1389                                                        BLKS_PER_SEC(sbi))
1390                        return submitted;
1391
1392                if (check_valid_map(sbi, segno, off) == 0)
1393                        continue;
1394
1395                if (phase == 0) {
1396                        f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1397                                                        META_NAT, true);
1398                        continue;
1399                }
1400
1401                if (phase == 1) {
1402                        f2fs_ra_node_page(sbi, nid);
1403                        continue;
1404                }
1405
1406                /* Get an inode by ino with checking validity */
1407                if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1408                        continue;
1409
1410                if (phase == 2) {
1411                        f2fs_ra_node_page(sbi, dni.ino);
1412                        continue;
1413                }
1414
1415                ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1416
1417                if (phase == 3) {
1418                        inode = f2fs_iget(sb, dni.ino);
1419                        if (IS_ERR(inode) || is_bad_inode(inode)) {
1420                                set_sbi_flag(sbi, SBI_NEED_FSCK);
1421                                continue;
1422                        }
1423
1424                        if (!down_write_trylock(
1425                                &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1426                                iput(inode);
1427                                sbi->skipped_gc_rwsem++;
1428                                continue;
1429                        }
1430
1431                        start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1432                                                                ofs_in_node;
1433
1434                        if (f2fs_post_read_required(inode)) {
1435                                int err = ra_data_block(inode, start_bidx);
1436
1437                                up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1438                                if (err) {
1439                                        iput(inode);
1440                                        continue;
1441                                }
1442                                add_gc_inode(gc_list, inode);
1443                                continue;
1444                        }
1445
1446                        data_page = f2fs_get_read_data_page(inode,
1447                                                start_bidx, REQ_RAHEAD, true);
1448                        up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1449                        if (IS_ERR(data_page)) {
1450                                iput(inode);
1451                                continue;
1452                        }
1453
1454                        f2fs_put_page(data_page, 0);
1455                        add_gc_inode(gc_list, inode);
1456                        continue;
1457                }
1458
1459                /* phase 4 */
1460                inode = find_gc_inode(gc_list, dni.ino);
1461                if (inode) {
1462                        struct f2fs_inode_info *fi = F2FS_I(inode);
1463                        bool locked = false;
1464                        int err;
1465
1466                        if (S_ISREG(inode->i_mode)) {
1467                                if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1468                                        continue;
1469                                if (!down_write_trylock(
1470                                                &fi->i_gc_rwsem[WRITE])) {
1471                                        sbi->skipped_gc_rwsem++;
1472                                        up_write(&fi->i_gc_rwsem[READ]);
1473                                        continue;
1474                                }
1475                                locked = true;
1476
1477                                /* wait for all inflight aio data */
1478                                inode_dio_wait(inode);
1479                        }
1480
1481                        start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1482                                                                + ofs_in_node;
1483                        if (f2fs_post_read_required(inode))
1484                                err = move_data_block(inode, start_bidx,
1485                                                        gc_type, segno, off);
1486                        else
1487                                err = move_data_page(inode, start_bidx, gc_type,
1488                                                                segno, off);
1489
1490                        if (!err && (gc_type == FG_GC ||
1491                                        f2fs_post_read_required(inode)))
1492                                submitted++;
1493
1494                        if (locked) {
1495                                up_write(&fi->i_gc_rwsem[WRITE]);
1496                                up_write(&fi->i_gc_rwsem[READ]);
1497                        }
1498
1499                        stat_inc_data_blk_count(sbi, 1, gc_type);
1500                }
1501        }
1502
1503        if (++phase < 5)
1504                goto next_step;
1505
1506        return submitted;
1507}
1508
1509static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1510                        int gc_type)
1511{
1512        struct sit_info *sit_i = SIT_I(sbi);
1513        int ret;
1514
1515        down_write(&sit_i->sentry_lock);
1516        ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1517                                              NO_CHECK_TYPE, LFS, 0);
1518        up_write(&sit_i->sentry_lock);
1519        return ret;
1520}
1521
1522static int do_garbage_collect(struct f2fs_sb_info *sbi,
1523                                unsigned int start_segno,
1524                                struct gc_inode_list *gc_list, int gc_type)
1525{
1526        struct page *sum_page;
1527        struct f2fs_summary_block *sum;
1528        struct blk_plug plug;
1529        unsigned int segno = start_segno;
1530        unsigned int end_segno = start_segno + sbi->segs_per_sec;
1531        int seg_freed = 0, migrated = 0;
1532        unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1533                                                SUM_TYPE_DATA : SUM_TYPE_NODE;
1534        int submitted = 0;
1535
1536        if (__is_large_section(sbi))
1537                end_segno = rounddown(end_segno, sbi->segs_per_sec);
1538
1539        /*
1540         * zone-capacity can be less than zone-size in zoned devices,
1541         * resulting in less than expected usable segments in the zone,
1542         * calculate the end segno in the zone which can be garbage collected
1543         */
1544        if (f2fs_sb_has_blkzoned(sbi))
1545                end_segno -= sbi->segs_per_sec -
1546                                        f2fs_usable_segs_in_sec(sbi, segno);
1547
1548        sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1549
1550        /* readahead multi ssa blocks those have contiguous address */
1551        if (__is_large_section(sbi))
1552                f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1553                                        end_segno - segno, META_SSA, true);
1554
1555        /* reference all summary page */
1556        while (segno < end_segno) {
1557                sum_page = f2fs_get_sum_page(sbi, segno++);
1558                if (IS_ERR(sum_page)) {
1559                        int err = PTR_ERR(sum_page);
1560
1561                        end_segno = segno - 1;
1562                        for (segno = start_segno; segno < end_segno; segno++) {
1563                                sum_page = find_get_page(META_MAPPING(sbi),
1564                                                GET_SUM_BLOCK(sbi, segno));
1565                                f2fs_put_page(sum_page, 0);
1566                                f2fs_put_page(sum_page, 0);
1567                        }
1568                        return err;
1569                }
1570                unlock_page(sum_page);
1571        }
1572
1573        blk_start_plug(&plug);
1574
1575        for (segno = start_segno; segno < end_segno; segno++) {
1576
1577                /* find segment summary of victim */
1578                sum_page = find_get_page(META_MAPPING(sbi),
1579                                        GET_SUM_BLOCK(sbi, segno));
1580                f2fs_put_page(sum_page, 0);
1581
1582                if (get_valid_blocks(sbi, segno, false) == 0)
1583                        goto freed;
1584                if (gc_type == BG_GC && __is_large_section(sbi) &&
1585                                migrated >= sbi->migration_granularity)
1586                        goto skip;
1587                if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1588                        goto skip;
1589
1590                sum = page_address(sum_page);
1591                if (type != GET_SUM_TYPE((&sum->footer))) {
1592                        f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1593                                 segno, type, GET_SUM_TYPE((&sum->footer)));
1594                        set_sbi_flag(sbi, SBI_NEED_FSCK);
1595                        f2fs_stop_checkpoint(sbi, false);
1596                        goto skip;
1597                }
1598
1599                /*
1600                 * this is to avoid deadlock:
1601                 * - lock_page(sum_page)         - f2fs_replace_block
1602                 *  - check_valid_map()            - down_write(sentry_lock)
1603                 *   - down_read(sentry_lock)     - change_curseg()
1604                 *                                  - lock_page(sum_page)
1605                 */
1606                if (type == SUM_TYPE_NODE)
1607                        submitted += gc_node_segment(sbi, sum->entries, segno,
1608                                                                gc_type);
1609                else
1610                        submitted += gc_data_segment(sbi, sum->entries, gc_list,
1611                                                        segno, gc_type);
1612
1613                stat_inc_seg_count(sbi, type, gc_type);
1614                migrated++;
1615
1616freed:
1617                if (gc_type == FG_GC &&
1618                                get_valid_blocks(sbi, segno, false) == 0)
1619                        seg_freed++;
1620
1621                if (__is_large_section(sbi) && segno + 1 < end_segno)
1622                        sbi->next_victim_seg[gc_type] = segno + 1;
1623skip:
1624                f2fs_put_page(sum_page, 0);
1625        }
1626
1627        if (submitted)
1628                f2fs_submit_merged_write(sbi,
1629                                (type == SUM_TYPE_NODE) ? NODE : DATA);
1630
1631        blk_finish_plug(&plug);
1632
1633        stat_inc_call_count(sbi->stat_info);
1634
1635        return seg_freed;
1636}
1637
1638int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1639                        bool background, unsigned int segno)
1640{
1641        int gc_type = sync ? FG_GC : BG_GC;
1642        int sec_freed = 0, seg_freed = 0, total_freed = 0;
1643        int ret = 0;
1644        struct cp_control cpc;
1645        unsigned int init_segno = segno;
1646        struct gc_inode_list gc_list = {
1647                .ilist = LIST_HEAD_INIT(gc_list.ilist),
1648                .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1649        };
1650        unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1651        unsigned long long first_skipped;
1652        unsigned int skipped_round = 0, round = 0;
1653
1654        trace_f2fs_gc_begin(sbi->sb, sync, background,
1655                                get_pages(sbi, F2FS_DIRTY_NODES),
1656                                get_pages(sbi, F2FS_DIRTY_DENTS),
1657                                get_pages(sbi, F2FS_DIRTY_IMETA),
1658                                free_sections(sbi),
1659                                free_segments(sbi),
1660                                reserved_segments(sbi),
1661                                prefree_segments(sbi));
1662
1663        cpc.reason = __get_cp_reason(sbi);
1664        sbi->skipped_gc_rwsem = 0;
1665        first_skipped = last_skipped;
1666gc_more:
1667        if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1668                ret = -EINVAL;
1669                goto stop;
1670        }
1671        if (unlikely(f2fs_cp_error(sbi))) {
1672                ret = -EIO;
1673                goto stop;
1674        }
1675
1676        if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1677                /*
1678                 * For example, if there are many prefree_segments below given
1679                 * threshold, we can make them free by checkpoint. Then, we
1680                 * secure free segments which doesn't need fggc any more.
1681                 */
1682                if (prefree_segments(sbi) &&
1683                                !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1684                        ret = f2fs_write_checkpoint(sbi, &cpc);
1685                        if (ret)
1686                                goto stop;
1687                }
1688                if (has_not_enough_free_secs(sbi, 0, 0))
1689                        gc_type = FG_GC;
1690        }
1691
1692        /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1693        if (gc_type == BG_GC && !background) {
1694                ret = -EINVAL;
1695                goto stop;
1696        }
1697        ret = __get_victim(sbi, &segno, gc_type);
1698        if (ret)
1699                goto stop;
1700
1701        seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1702        if (gc_type == FG_GC &&
1703                seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1704                sec_freed++;
1705        total_freed += seg_freed;
1706
1707        if (gc_type == FG_GC) {
1708                if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1709                                                sbi->skipped_gc_rwsem)
1710                        skipped_round++;
1711                last_skipped = sbi->skipped_atomic_files[FG_GC];
1712                round++;
1713        }
1714
1715        if (gc_type == FG_GC && seg_freed)
1716                sbi->cur_victim_sec = NULL_SEGNO;
1717
1718        if (sync)
1719                goto stop;
1720
1721        if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1722                if (skipped_round <= MAX_SKIP_GC_COUNT ||
1723                                        skipped_round * 2 < round) {
1724                        segno = NULL_SEGNO;
1725                        goto gc_more;
1726                }
1727
1728                if (first_skipped < last_skipped &&
1729                                (last_skipped - first_skipped) >
1730                                                sbi->skipped_gc_rwsem) {
1731                        f2fs_drop_inmem_pages_all(sbi, true);
1732                        segno = NULL_SEGNO;
1733                        goto gc_more;
1734                }
1735                if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1736                        ret = f2fs_write_checkpoint(sbi, &cpc);
1737        }
1738stop:
1739        SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1740        SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1741
1742        trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1743                                get_pages(sbi, F2FS_DIRTY_NODES),
1744                                get_pages(sbi, F2FS_DIRTY_DENTS),
1745                                get_pages(sbi, F2FS_DIRTY_IMETA),
1746                                free_sections(sbi),
1747                                free_segments(sbi),
1748                                reserved_segments(sbi),
1749                                prefree_segments(sbi));
1750
1751        up_write(&sbi->gc_lock);
1752
1753        put_gc_inode(&gc_list);
1754
1755        if (sync && !ret)
1756                ret = sec_freed ? 0 : -EAGAIN;
1757        return ret;
1758}
1759
1760int __init f2fs_create_garbage_collection_cache(void)
1761{
1762        victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1763                                        sizeof(struct victim_entry));
1764        if (!victim_entry_slab)
1765                return -ENOMEM;
1766        return 0;
1767}
1768
1769void f2fs_destroy_garbage_collection_cache(void)
1770{
1771        kmem_cache_destroy(victim_entry_slab);
1772}
1773
1774static void init_atgc_management(struct f2fs_sb_info *sbi)
1775{
1776        struct atgc_management *am = &sbi->am;
1777
1778        if (test_opt(sbi, ATGC) &&
1779                SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1780                am->atgc_enabled = true;
1781
1782        am->root = RB_ROOT_CACHED;
1783        INIT_LIST_HEAD(&am->victim_list);
1784        am->victim_count = 0;
1785
1786        am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1787        am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1788        am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1789}
1790
1791void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1792{
1793        DIRTY_I(sbi)->v_ops = &default_v_ops;
1794
1795        sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1796
1797        /* give warm/cold data area from slower device */
1798        if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1799                SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1800                                GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1801
1802        init_atgc_management(sbi);
1803}
1804
1805static int free_segment_range(struct f2fs_sb_info *sbi,
1806                                unsigned int secs, bool gc_only)
1807{
1808        unsigned int segno, next_inuse, start, end;
1809        struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1810        int gc_mode, gc_type;
1811        int err = 0;
1812        int type;
1813
1814        /* Force block allocation for GC */
1815        MAIN_SECS(sbi) -= secs;
1816        start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1817        end = MAIN_SEGS(sbi) - 1;
1818
1819        mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1820        for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1821                if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1822                        SIT_I(sbi)->last_victim[gc_mode] = 0;
1823
1824        for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1825                if (sbi->next_victim_seg[gc_type] >= start)
1826                        sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1827        mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1828
1829        /* Move out cursegs from the target range */
1830        for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1831                f2fs_allocate_segment_for_resize(sbi, type, start, end);
1832
1833        /* do GC to move out valid blocks in the range */
1834        for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1835                struct gc_inode_list gc_list = {
1836                        .ilist = LIST_HEAD_INIT(gc_list.ilist),
1837                        .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1838                };
1839
1840                do_garbage_collect(sbi, segno, &gc_list, FG_GC);
1841                put_gc_inode(&gc_list);
1842
1843                if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1844                        err = -EAGAIN;
1845                        goto out;
1846                }
1847                if (fatal_signal_pending(current)) {
1848                        err = -ERESTARTSYS;
1849                        goto out;
1850                }
1851        }
1852        if (gc_only)
1853                goto out;
1854
1855        err = f2fs_write_checkpoint(sbi, &cpc);
1856        if (err)
1857                goto out;
1858
1859        next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1860        if (next_inuse <= end) {
1861                f2fs_err(sbi, "segno %u should be free but still inuse!",
1862                         next_inuse);
1863                f2fs_bug_on(sbi, 1);
1864        }
1865out:
1866        MAIN_SECS(sbi) += secs;
1867        return err;
1868}
1869
1870static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1871{
1872        struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1873        int section_count;
1874        int segment_count;
1875        int segment_count_main;
1876        long long block_count;
1877        int segs = secs * sbi->segs_per_sec;
1878
1879        down_write(&sbi->sb_lock);
1880
1881        section_count = le32_to_cpu(raw_sb->section_count);
1882        segment_count = le32_to_cpu(raw_sb->segment_count);
1883        segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1884        block_count = le64_to_cpu(raw_sb->block_count);
1885
1886        raw_sb->section_count = cpu_to_le32(section_count + secs);
1887        raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1888        raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1889        raw_sb->block_count = cpu_to_le64(block_count +
1890                                        (long long)segs * sbi->blocks_per_seg);
1891        if (f2fs_is_multi_device(sbi)) {
1892                int last_dev = sbi->s_ndevs - 1;
1893                int dev_segs =
1894                        le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1895
1896                raw_sb->devs[last_dev].total_segments =
1897                                                cpu_to_le32(dev_segs + segs);
1898        }
1899
1900        up_write(&sbi->sb_lock);
1901}
1902
1903static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1904{
1905        int segs = secs * sbi->segs_per_sec;
1906        long long blks = (long long)segs * sbi->blocks_per_seg;
1907        long long user_block_count =
1908                                le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1909
1910        SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1911        MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1912        MAIN_SECS(sbi) += secs;
1913        FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1914        FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1915        F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1916
1917        if (f2fs_is_multi_device(sbi)) {
1918                int last_dev = sbi->s_ndevs - 1;
1919
1920                FDEV(last_dev).total_segments =
1921                                (int)FDEV(last_dev).total_segments + segs;
1922                FDEV(last_dev).end_blk =
1923                                (long long)FDEV(last_dev).end_blk + blks;
1924#ifdef CONFIG_BLK_DEV_ZONED
1925                FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1926                                        (int)(blks >> sbi->log_blocks_per_blkz);
1927#endif
1928        }
1929}
1930
1931int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1932{
1933        __u64 old_block_count, shrunk_blocks;
1934        struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1935        unsigned int secs;
1936        int err = 0;
1937        __u32 rem;
1938
1939        old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1940        if (block_count > old_block_count)
1941                return -EINVAL;
1942
1943        if (f2fs_is_multi_device(sbi)) {
1944                int last_dev = sbi->s_ndevs - 1;
1945                __u64 last_segs = FDEV(last_dev).total_segments;
1946
1947                if (block_count + last_segs * sbi->blocks_per_seg <=
1948                                                                old_block_count)
1949                        return -EINVAL;
1950        }
1951
1952        /* new fs size should align to section size */
1953        div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
1954        if (rem)
1955                return -EINVAL;
1956
1957        if (block_count == old_block_count)
1958                return 0;
1959
1960        if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1961                f2fs_err(sbi, "Should run fsck to repair first.");
1962                return -EFSCORRUPTED;
1963        }
1964
1965        if (test_opt(sbi, DISABLE_CHECKPOINT)) {
1966                f2fs_err(sbi, "Checkpoint should be enabled.");
1967                return -EINVAL;
1968        }
1969
1970        shrunk_blocks = old_block_count - block_count;
1971        secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
1972
1973        /* stop other GC */
1974        if (!down_write_trylock(&sbi->gc_lock))
1975                return -EAGAIN;
1976
1977        /* stop CP to protect MAIN_SEC in free_segment_range */
1978        f2fs_lock_op(sbi);
1979        err = free_segment_range(sbi, secs, true);
1980        f2fs_unlock_op(sbi);
1981        up_write(&sbi->gc_lock);
1982        if (err)
1983                return err;
1984
1985        set_sbi_flag(sbi, SBI_IS_RESIZEFS);
1986
1987        freeze_super(sbi->sb);
1988        down_write(&sbi->gc_lock);
1989        mutex_lock(&sbi->cp_mutex);
1990
1991        spin_lock(&sbi->stat_lock);
1992        if (shrunk_blocks + valid_user_blocks(sbi) +
1993                sbi->current_reserved_blocks + sbi->unusable_block_count +
1994                F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
1995                err = -ENOSPC;
1996        else
1997                sbi->user_block_count -= shrunk_blocks;
1998        spin_unlock(&sbi->stat_lock);
1999        if (err)
2000                goto out_err;
2001
2002        err = free_segment_range(sbi, secs, false);
2003        if (err)
2004                goto recover_out;
2005
2006        update_sb_metadata(sbi, -secs);
2007
2008        err = f2fs_commit_super(sbi, false);
2009        if (err) {
2010                update_sb_metadata(sbi, secs);
2011                goto recover_out;
2012        }
2013
2014        update_fs_metadata(sbi, -secs);
2015        clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2016        set_sbi_flag(sbi, SBI_IS_DIRTY);
2017
2018        err = f2fs_write_checkpoint(sbi, &cpc);
2019        if (err) {
2020                update_fs_metadata(sbi, secs);
2021                update_sb_metadata(sbi, secs);
2022                f2fs_commit_super(sbi, false);
2023        }
2024recover_out:
2025        if (err) {
2026                set_sbi_flag(sbi, SBI_NEED_FSCK);
2027                f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2028
2029                spin_lock(&sbi->stat_lock);
2030                sbi->user_block_count += shrunk_blocks;
2031                spin_unlock(&sbi->stat_lock);
2032        }
2033out_err:
2034        mutex_unlock(&sbi->cp_mutex);
2035        up_write(&sbi->gc_lock);
2036        thaw_super(sbi->sb);
2037        clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2038        return err;
2039}
2040