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        wait_queue_head_t *fggc_wq = &sbi->gc_thread->fggc_wq;
  35        unsigned int wait_ms;
  36
  37        wait_ms = gc_th->min_sleep_time;
  38
  39        set_freezable();
  40        do {
  41                bool sync_mode, foreground = false;
  42
  43                wait_event_interruptible_timeout(*wq,
  44                                kthread_should_stop() || freezing(current) ||
  45                                waitqueue_active(fggc_wq) ||
  46                                gc_th->gc_wake,
  47                                msecs_to_jiffies(wait_ms));
  48
  49                if (test_opt(sbi, GC_MERGE) && waitqueue_active(fggc_wq))
  50                        foreground = true;
  51
  52                /* give it a try one time */
  53                if (gc_th->gc_wake)
  54                        gc_th->gc_wake = 0;
  55
  56                if (try_to_freeze()) {
  57                        stat_other_skip_bggc_count(sbi);
  58                        continue;
  59                }
  60                if (kthread_should_stop())
  61                        break;
  62
  63                if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  64                        increase_sleep_time(gc_th, &wait_ms);
  65                        stat_other_skip_bggc_count(sbi);
  66                        continue;
  67                }
  68
  69                if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  70                        f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  71                        f2fs_stop_checkpoint(sbi, false);
  72                }
  73
  74                if (!sb_start_write_trylock(sbi->sb)) {
  75                        stat_other_skip_bggc_count(sbi);
  76                        continue;
  77                }
  78
  79                /*
  80                 * [GC triggering condition]
  81                 * 0. GC is not conducted currently.
  82                 * 1. There are enough dirty segments.
  83                 * 2. IO subsystem is idle by checking the # of writeback pages.
  84                 * 3. IO subsystem is idle by checking the # of requests in
  85                 *    bdev's request list.
  86                 *
  87                 * Note) We have to avoid triggering GCs frequently.
  88                 * Because it is possible that some segments can be
  89                 * invalidated soon after by user update or deletion.
  90                 * So, I'd like to wait some time to collect dirty segments.
  91                 */
  92                if (sbi->gc_mode == GC_URGENT_HIGH) {
  93                        wait_ms = gc_th->urgent_sleep_time;
  94                        down_write(&sbi->gc_lock);
  95                        goto do_gc;
  96                }
  97
  98                if (foreground) {
  99                        down_write(&sbi->gc_lock);
 100                        goto do_gc;
 101                } else if (!down_write_trylock(&sbi->gc_lock)) {
 102                        stat_other_skip_bggc_count(sbi);
 103                        goto next;
 104                }
 105
 106                if (!is_idle(sbi, GC_TIME)) {
 107                        increase_sleep_time(gc_th, &wait_ms);
 108                        up_write(&sbi->gc_lock);
 109                        stat_io_skip_bggc_count(sbi);
 110                        goto next;
 111                }
 112
 113                if (has_enough_invalid_blocks(sbi))
 114                        decrease_sleep_time(gc_th, &wait_ms);
 115                else
 116                        increase_sleep_time(gc_th, &wait_ms);
 117do_gc:
 118                if (!foreground)
 119                        stat_inc_bggc_count(sbi->stat_info);
 120
 121                sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 122
 123                /* foreground GC was been triggered via f2fs_balance_fs() */
 124                if (foreground)
 125                        sync_mode = false;
 126
 127                /* if return value is not zero, no victim was selected */
 128                if (f2fs_gc(sbi, sync_mode, !foreground, false, NULL_SEGNO))
 129                        wait_ms = gc_th->no_gc_sleep_time;
 130
 131                if (foreground)
 132                        wake_up_all(&gc_th->fggc_wq);
 133
 134                trace_f2fs_background_gc(sbi->sb, wait_ms,
 135                                prefree_segments(sbi), free_segments(sbi));
 136
 137                /* balancing f2fs's metadata periodically */
 138                f2fs_balance_fs_bg(sbi, true);
 139next:
 140                sb_end_write(sbi->sb);
 141
 142        } while (!kthread_should_stop());
 143        return 0;
 144}
 145
 146int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 147{
 148        struct f2fs_gc_kthread *gc_th;
 149        dev_t dev = sbi->sb->s_bdev->bd_dev;
 150        int err = 0;
 151
 152        gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 153        if (!gc_th) {
 154                err = -ENOMEM;
 155                goto out;
 156        }
 157
 158        gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 159        gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 160        gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 161        gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 162
 163        gc_th->gc_wake = 0;
 164
 165        sbi->gc_thread = gc_th;
 166        init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 167        init_waitqueue_head(&sbi->gc_thread->fggc_wq);
 168        sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 169                        "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 170        if (IS_ERR(gc_th->f2fs_gc_task)) {
 171                err = PTR_ERR(gc_th->f2fs_gc_task);
 172                kfree(gc_th);
 173                sbi->gc_thread = NULL;
 174        }
 175out:
 176        return err;
 177}
 178
 179void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 180{
 181        struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 182
 183        if (!gc_th)
 184                return;
 185        kthread_stop(gc_th->f2fs_gc_task);
 186        wake_up_all(&gc_th->fggc_wq);
 187        kfree(gc_th);
 188        sbi->gc_thread = NULL;
 189}
 190
 191static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 192{
 193        int gc_mode;
 194
 195        if (gc_type == BG_GC) {
 196                if (sbi->am.atgc_enabled)
 197                        gc_mode = GC_AT;
 198                else
 199                        gc_mode = GC_CB;
 200        } else {
 201                gc_mode = GC_GREEDY;
 202        }
 203
 204        switch (sbi->gc_mode) {
 205        case GC_IDLE_CB:
 206                gc_mode = GC_CB;
 207                break;
 208        case GC_IDLE_GREEDY:
 209        case GC_URGENT_HIGH:
 210                gc_mode = GC_GREEDY;
 211                break;
 212        case GC_IDLE_AT:
 213                gc_mode = GC_AT;
 214                break;
 215        }
 216
 217        return gc_mode;
 218}
 219
 220static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 221                        int type, struct victim_sel_policy *p)
 222{
 223        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 224
 225        if (p->alloc_mode == SSR) {
 226                p->gc_mode = GC_GREEDY;
 227                p->dirty_bitmap = dirty_i->dirty_segmap[type];
 228                p->max_search = dirty_i->nr_dirty[type];
 229                p->ofs_unit = 1;
 230        } else if (p->alloc_mode == AT_SSR) {
 231                p->gc_mode = GC_GREEDY;
 232                p->dirty_bitmap = dirty_i->dirty_segmap[type];
 233                p->max_search = dirty_i->nr_dirty[type];
 234                p->ofs_unit = 1;
 235        } else {
 236                p->gc_mode = select_gc_type(sbi, gc_type);
 237                p->ofs_unit = sbi->segs_per_sec;
 238                if (__is_large_section(sbi)) {
 239                        p->dirty_bitmap = dirty_i->dirty_secmap;
 240                        p->max_search = count_bits(p->dirty_bitmap,
 241                                                0, MAIN_SECS(sbi));
 242                } else {
 243                        p->dirty_bitmap = dirty_i->dirty_segmap[DIRTY];
 244                        p->max_search = dirty_i->nr_dirty[DIRTY];
 245                }
 246        }
 247
 248        /*
 249         * adjust candidates range, should select all dirty segments for
 250         * foreground GC and urgent GC cases.
 251         */
 252        if (gc_type != FG_GC &&
 253                        (sbi->gc_mode != GC_URGENT_HIGH) &&
 254                        (p->gc_mode != GC_AT && p->alloc_mode != AT_SSR) &&
 255                        p->max_search > sbi->max_victim_search)
 256                p->max_search = sbi->max_victim_search;
 257
 258        /* let's select beginning hot/small space first in no_heap mode*/
 259        if (test_opt(sbi, NOHEAP) &&
 260                (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 261                p->offset = 0;
 262        else
 263                p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 264}
 265
 266static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 267                                struct victim_sel_policy *p)
 268{
 269        /* SSR allocates in a segment unit */
 270        if (p->alloc_mode == SSR)
 271                return sbi->blocks_per_seg;
 272        else if (p->alloc_mode == AT_SSR)
 273                return UINT_MAX;
 274
 275        /* LFS */
 276        if (p->gc_mode == GC_GREEDY)
 277                return 2 * sbi->blocks_per_seg * p->ofs_unit;
 278        else if (p->gc_mode == GC_CB)
 279                return UINT_MAX;
 280        else if (p->gc_mode == GC_AT)
 281                return UINT_MAX;
 282        else /* No other gc_mode */
 283                return 0;
 284}
 285
 286static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 287{
 288        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 289        unsigned int secno;
 290
 291        /*
 292         * If the gc_type is FG_GC, we can select victim segments
 293         * selected by background GC before.
 294         * Those segments guarantee they have small valid blocks.
 295         */
 296        for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 297                if (sec_usage_check(sbi, secno))
 298                        continue;
 299                clear_bit(secno, dirty_i->victim_secmap);
 300                return GET_SEG_FROM_SEC(sbi, secno);
 301        }
 302        return NULL_SEGNO;
 303}
 304
 305static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 306{
 307        struct sit_info *sit_i = SIT_I(sbi);
 308        unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 309        unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 310        unsigned long long mtime = 0;
 311        unsigned int vblocks;
 312        unsigned char age = 0;
 313        unsigned char u;
 314        unsigned int i;
 315        unsigned int usable_segs_per_sec = f2fs_usable_segs_in_sec(sbi, segno);
 316
 317        for (i = 0; i < usable_segs_per_sec; i++)
 318                mtime += get_seg_entry(sbi, start + i)->mtime;
 319        vblocks = get_valid_blocks(sbi, segno, true);
 320
 321        mtime = div_u64(mtime, usable_segs_per_sec);
 322        vblocks = div_u64(vblocks, usable_segs_per_sec);
 323
 324        u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 325
 326        /* Handle if the system time has changed by the user */
 327        if (mtime < sit_i->min_mtime)
 328                sit_i->min_mtime = mtime;
 329        if (mtime > sit_i->max_mtime)
 330                sit_i->max_mtime = mtime;
 331        if (sit_i->max_mtime != sit_i->min_mtime)
 332                age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 333                                sit_i->max_mtime - sit_i->min_mtime);
 334
 335        return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 336}
 337
 338static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 339                        unsigned int segno, struct victim_sel_policy *p)
 340{
 341        if (p->alloc_mode == SSR)
 342                return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 343
 344        /* alloc_mode == LFS */
 345        if (p->gc_mode == GC_GREEDY)
 346                return get_valid_blocks(sbi, segno, true);
 347        else if (p->gc_mode == GC_CB)
 348                return get_cb_cost(sbi, segno);
 349
 350        f2fs_bug_on(sbi, 1);
 351        return 0;
 352}
 353
 354static unsigned int count_bits(const unsigned long *addr,
 355                                unsigned int offset, unsigned int len)
 356{
 357        unsigned int end = offset + len, sum = 0;
 358
 359        while (offset < end) {
 360                if (test_bit(offset++, addr))
 361                        ++sum;
 362        }
 363        return sum;
 364}
 365
 366static struct victim_entry *attach_victim_entry(struct f2fs_sb_info *sbi,
 367                                unsigned long long mtime, unsigned int segno,
 368                                struct rb_node *parent, struct rb_node **p,
 369                                bool left_most)
 370{
 371        struct atgc_management *am = &sbi->am;
 372        struct victim_entry *ve;
 373
 374        ve =  f2fs_kmem_cache_alloc(victim_entry_slab, GFP_NOFS);
 375
 376        ve->mtime = mtime;
 377        ve->segno = segno;
 378
 379        rb_link_node(&ve->rb_node, parent, p);
 380        rb_insert_color_cached(&ve->rb_node, &am->root, left_most);
 381
 382        list_add_tail(&ve->list, &am->victim_list);
 383
 384        am->victim_count++;
 385
 386        return ve;
 387}
 388
 389static void insert_victim_entry(struct f2fs_sb_info *sbi,
 390                                unsigned long long mtime, unsigned int segno)
 391{
 392        struct atgc_management *am = &sbi->am;
 393        struct rb_node **p;
 394        struct rb_node *parent = NULL;
 395        bool left_most = true;
 396
 397        p = f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, mtime, &left_most);
 398        attach_victim_entry(sbi, mtime, segno, parent, p, left_most);
 399}
 400
 401static void add_victim_entry(struct f2fs_sb_info *sbi,
 402                                struct victim_sel_policy *p, unsigned int segno)
 403{
 404        struct sit_info *sit_i = SIT_I(sbi);
 405        unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 406        unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 407        unsigned long long mtime = 0;
 408        unsigned int i;
 409
 410        if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 411                if (p->gc_mode == GC_AT &&
 412                        get_valid_blocks(sbi, segno, true) == 0)
 413                        return;
 414        }
 415
 416        for (i = 0; i < sbi->segs_per_sec; i++)
 417                mtime += get_seg_entry(sbi, start + i)->mtime;
 418        mtime = div_u64(mtime, sbi->segs_per_sec);
 419
 420        /* Handle if the system time has changed by the user */
 421        if (mtime < sit_i->min_mtime)
 422                sit_i->min_mtime = mtime;
 423        if (mtime > sit_i->max_mtime)
 424                sit_i->max_mtime = mtime;
 425        if (mtime < sit_i->dirty_min_mtime)
 426                sit_i->dirty_min_mtime = mtime;
 427        if (mtime > sit_i->dirty_max_mtime)
 428                sit_i->dirty_max_mtime = mtime;
 429
 430        /* don't choose young section as candidate */
 431        if (sit_i->dirty_max_mtime - mtime < p->age_threshold)
 432                return;
 433
 434        insert_victim_entry(sbi, mtime, segno);
 435}
 436
 437static struct rb_node *lookup_central_victim(struct f2fs_sb_info *sbi,
 438                                                struct victim_sel_policy *p)
 439{
 440        struct atgc_management *am = &sbi->am;
 441        struct rb_node *parent = NULL;
 442        bool left_most;
 443
 444        f2fs_lookup_rb_tree_ext(sbi, &am->root, &parent, p->age, &left_most);
 445
 446        return parent;
 447}
 448
 449static void atgc_lookup_victim(struct f2fs_sb_info *sbi,
 450                                                struct victim_sel_policy *p)
 451{
 452        struct sit_info *sit_i = SIT_I(sbi);
 453        struct atgc_management *am = &sbi->am;
 454        struct rb_root_cached *root = &am->root;
 455        struct rb_node *node;
 456        struct rb_entry *re;
 457        struct victim_entry *ve;
 458        unsigned long long total_time;
 459        unsigned long long age, u, accu;
 460        unsigned long long max_mtime = sit_i->dirty_max_mtime;
 461        unsigned long long min_mtime = sit_i->dirty_min_mtime;
 462        unsigned int sec_blocks = BLKS_PER_SEC(sbi);
 463        unsigned int vblocks;
 464        unsigned int dirty_threshold = max(am->max_candidate_count,
 465                                        am->candidate_ratio *
 466                                        am->victim_count / 100);
 467        unsigned int age_weight = am->age_weight;
 468        unsigned int cost;
 469        unsigned int iter = 0;
 470
 471        if (max_mtime < min_mtime)
 472                return;
 473
 474        max_mtime += 1;
 475        total_time = max_mtime - min_mtime;
 476
 477        accu = div64_u64(ULLONG_MAX, total_time);
 478        accu = min_t(unsigned long long, div_u64(accu, 100),
 479                                        DEFAULT_ACCURACY_CLASS);
 480
 481        node = rb_first_cached(root);
 482next:
 483        re = rb_entry_safe(node, struct rb_entry, rb_node);
 484        if (!re)
 485                return;
 486
 487        ve = (struct victim_entry *)re;
 488
 489        if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 490                goto skip;
 491
 492        /* age = 10000 * x% * 60 */
 493        age = div64_u64(accu * (max_mtime - ve->mtime), total_time) *
 494                                                                age_weight;
 495
 496        vblocks = get_valid_blocks(sbi, ve->segno, true);
 497        f2fs_bug_on(sbi, !vblocks || vblocks == sec_blocks);
 498
 499        /* u = 10000 * x% * 40 */
 500        u = div64_u64(accu * (sec_blocks - vblocks), sec_blocks) *
 501                                                        (100 - age_weight);
 502
 503        f2fs_bug_on(sbi, age + u >= UINT_MAX);
 504
 505        cost = UINT_MAX - (age + u);
 506        iter++;
 507
 508        if (cost < p->min_cost ||
 509                        (cost == p->min_cost && age > p->oldest_age)) {
 510                p->min_cost = cost;
 511                p->oldest_age = age;
 512                p->min_segno = ve->segno;
 513        }
 514skip:
 515        if (iter < dirty_threshold) {
 516                node = rb_next(node);
 517                goto next;
 518        }
 519}
 520
 521/*
 522 * select candidates around source section in range of
 523 * [target - dirty_threshold, target + dirty_threshold]
 524 */
 525static void atssr_lookup_victim(struct f2fs_sb_info *sbi,
 526                                                struct victim_sel_policy *p)
 527{
 528        struct sit_info *sit_i = SIT_I(sbi);
 529        struct atgc_management *am = &sbi->am;
 530        struct rb_node *node;
 531        struct rb_entry *re;
 532        struct victim_entry *ve;
 533        unsigned long long age;
 534        unsigned long long max_mtime = sit_i->dirty_max_mtime;
 535        unsigned long long min_mtime = sit_i->dirty_min_mtime;
 536        unsigned int seg_blocks = sbi->blocks_per_seg;
 537        unsigned int vblocks;
 538        unsigned int dirty_threshold = max(am->max_candidate_count,
 539                                        am->candidate_ratio *
 540                                        am->victim_count / 100);
 541        unsigned int cost;
 542        unsigned int iter = 0;
 543        int stage = 0;
 544
 545        if (max_mtime < min_mtime)
 546                return;
 547        max_mtime += 1;
 548next_stage:
 549        node = lookup_central_victim(sbi, p);
 550next_node:
 551        re = rb_entry_safe(node, struct rb_entry, rb_node);
 552        if (!re) {
 553                if (stage == 0)
 554                        goto skip_stage;
 555                return;
 556        }
 557
 558        ve = (struct victim_entry *)re;
 559
 560        if (ve->mtime >= max_mtime || ve->mtime < min_mtime)
 561                goto skip_node;
 562
 563        age = max_mtime - ve->mtime;
 564
 565        vblocks = get_seg_entry(sbi, ve->segno)->ckpt_valid_blocks;
 566        f2fs_bug_on(sbi, !vblocks);
 567
 568        /* rare case */
 569        if (vblocks == seg_blocks)
 570                goto skip_node;
 571
 572        iter++;
 573
 574        age = max_mtime - abs(p->age - age);
 575        cost = UINT_MAX - vblocks;
 576
 577        if (cost < p->min_cost ||
 578                        (cost == p->min_cost && age > p->oldest_age)) {
 579                p->min_cost = cost;
 580                p->oldest_age = age;
 581                p->min_segno = ve->segno;
 582        }
 583skip_node:
 584        if (iter < dirty_threshold) {
 585                if (stage == 0)
 586                        node = rb_prev(node);
 587                else if (stage == 1)
 588                        node = rb_next(node);
 589                goto next_node;
 590        }
 591skip_stage:
 592        if (stage < 1) {
 593                stage++;
 594                iter = 0;
 595                goto next_stage;
 596        }
 597}
 598static void lookup_victim_by_age(struct f2fs_sb_info *sbi,
 599                                                struct victim_sel_policy *p)
 600{
 601        f2fs_bug_on(sbi, !f2fs_check_rb_tree_consistence(sbi,
 602                                                &sbi->am.root, true));
 603
 604        if (p->gc_mode == GC_AT)
 605                atgc_lookup_victim(sbi, p);
 606        else if (p->alloc_mode == AT_SSR)
 607                atssr_lookup_victim(sbi, p);
 608        else
 609                f2fs_bug_on(sbi, 1);
 610}
 611
 612static void release_victim_entry(struct f2fs_sb_info *sbi)
 613{
 614        struct atgc_management *am = &sbi->am;
 615        struct victim_entry *ve, *tmp;
 616
 617        list_for_each_entry_safe(ve, tmp, &am->victim_list, list) {
 618                list_del(&ve->list);
 619                kmem_cache_free(victim_entry_slab, ve);
 620                am->victim_count--;
 621        }
 622
 623        am->root = RB_ROOT_CACHED;
 624
 625        f2fs_bug_on(sbi, am->victim_count);
 626        f2fs_bug_on(sbi, !list_empty(&am->victim_list));
 627}
 628
 629/*
 630 * This function is called from two paths.
 631 * One is garbage collection and the other is SSR segment selection.
 632 * When it is called during GC, it just gets a victim segment
 633 * and it does not remove it from dirty seglist.
 634 * When it is called from SSR segment selection, it finds a segment
 635 * which has minimum valid blocks and removes it from dirty seglist.
 636 */
 637static int get_victim_by_default(struct f2fs_sb_info *sbi,
 638                        unsigned int *result, int gc_type, int type,
 639                        char alloc_mode, unsigned long long age)
 640{
 641        struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 642        struct sit_info *sm = SIT_I(sbi);
 643        struct victim_sel_policy p;
 644        unsigned int secno, last_victim;
 645        unsigned int last_segment;
 646        unsigned int nsearched;
 647        bool is_atgc;
 648        int ret = 0;
 649
 650        mutex_lock(&dirty_i->seglist_lock);
 651        last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 652
 653        p.alloc_mode = alloc_mode;
 654        p.age = age;
 655        p.age_threshold = sbi->am.age_threshold;
 656
 657retry:
 658        select_policy(sbi, gc_type, type, &p);
 659        p.min_segno = NULL_SEGNO;
 660        p.oldest_age = 0;
 661        p.min_cost = get_max_cost(sbi, &p);
 662
 663        is_atgc = (p.gc_mode == GC_AT || p.alloc_mode == AT_SSR);
 664        nsearched = 0;
 665
 666        if (is_atgc)
 667                SIT_I(sbi)->dirty_min_mtime = ULLONG_MAX;
 668
 669        if (*result != NULL_SEGNO) {
 670                if (!get_valid_blocks(sbi, *result, false)) {
 671                        ret = -ENODATA;
 672                        goto out;
 673                }
 674
 675                if (sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 676                        ret = -EBUSY;
 677                else
 678                        p.min_segno = *result;
 679                goto out;
 680        }
 681
 682        ret = -ENODATA;
 683        if (p.max_search == 0)
 684                goto out;
 685
 686        if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 687                if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 688                        p.min_segno = sbi->next_victim_seg[BG_GC];
 689                        *result = p.min_segno;
 690                        sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 691                        goto got_result;
 692                }
 693                if (gc_type == FG_GC &&
 694                                sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 695                        p.min_segno = sbi->next_victim_seg[FG_GC];
 696                        *result = p.min_segno;
 697                        sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 698                        goto got_result;
 699                }
 700        }
 701
 702        last_victim = sm->last_victim[p.gc_mode];
 703        if (p.alloc_mode == LFS && gc_type == FG_GC) {
 704                p.min_segno = check_bg_victims(sbi);
 705                if (p.min_segno != NULL_SEGNO)
 706                        goto got_it;
 707        }
 708
 709        while (1) {
 710                unsigned long cost, *dirty_bitmap;
 711                unsigned int unit_no, segno;
 712
 713                dirty_bitmap = p.dirty_bitmap;
 714                unit_no = find_next_bit(dirty_bitmap,
 715                                last_segment / p.ofs_unit,
 716                                p.offset / p.ofs_unit);
 717                segno = unit_no * p.ofs_unit;
 718                if (segno >= last_segment) {
 719                        if (sm->last_victim[p.gc_mode]) {
 720                                last_segment =
 721                                        sm->last_victim[p.gc_mode];
 722                                sm->last_victim[p.gc_mode] = 0;
 723                                p.offset = 0;
 724                                continue;
 725                        }
 726                        break;
 727                }
 728
 729                p.offset = segno + p.ofs_unit;
 730                nsearched++;
 731
 732#ifdef CONFIG_F2FS_CHECK_FS
 733                /*
 734                 * skip selecting the invalid segno (that is failed due to block
 735                 * validity check failure during GC) to avoid endless GC loop in
 736                 * such cases.
 737                 */
 738                if (test_bit(segno, sm->invalid_segmap))
 739                        goto next;
 740#endif
 741
 742                secno = GET_SEC_FROM_SEG(sbi, segno);
 743
 744                if (sec_usage_check(sbi, secno))
 745                        goto next;
 746
 747                /* Don't touch checkpointed data */
 748                if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED))) {
 749                        if (p.alloc_mode == LFS) {
 750                                /*
 751                                 * LFS is set to find source section during GC.
 752                                 * The victim should have no checkpointed data.
 753                                 */
 754                                if (get_ckpt_valid_blocks(sbi, segno, true))
 755                                        goto next;
 756                        } else {
 757                                /*
 758                                 * SSR | AT_SSR are set to find target segment
 759                                 * for writes which can be full by checkpointed
 760                                 * and newly written blocks.
 761                                 */
 762                                if (!f2fs_segment_has_free_slot(sbi, segno))
 763                                        goto next;
 764                        }
 765                }
 766
 767                if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 768                        goto next;
 769
 770                if (is_atgc) {
 771                        add_victim_entry(sbi, &p, segno);
 772                        goto next;
 773                }
 774
 775                cost = get_gc_cost(sbi, segno, &p);
 776
 777                if (p.min_cost > cost) {
 778                        p.min_segno = segno;
 779                        p.min_cost = cost;
 780                }
 781next:
 782                if (nsearched >= p.max_search) {
 783                        if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 784                                sm->last_victim[p.gc_mode] =
 785                                        last_victim + p.ofs_unit;
 786                        else
 787                                sm->last_victim[p.gc_mode] = segno + p.ofs_unit;
 788                        sm->last_victim[p.gc_mode] %=
 789                                (MAIN_SECS(sbi) * sbi->segs_per_sec);
 790                        break;
 791                }
 792        }
 793
 794        /* get victim for GC_AT/AT_SSR */
 795        if (is_atgc) {
 796                lookup_victim_by_age(sbi, &p);
 797                release_victim_entry(sbi);
 798        }
 799
 800        if (is_atgc && p.min_segno == NULL_SEGNO &&
 801                        sm->elapsed_time < p.age_threshold) {
 802                p.age_threshold = 0;
 803                goto retry;
 804        }
 805
 806        if (p.min_segno != NULL_SEGNO) {
 807got_it:
 808                *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 809got_result:
 810                if (p.alloc_mode == LFS) {
 811                        secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 812                        if (gc_type == FG_GC)
 813                                sbi->cur_victim_sec = secno;
 814                        else
 815                                set_bit(secno, dirty_i->victim_secmap);
 816                }
 817                ret = 0;
 818
 819        }
 820out:
 821        if (p.min_segno != NULL_SEGNO)
 822                trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 823                                sbi->cur_victim_sec,
 824                                prefree_segments(sbi), free_segments(sbi));
 825        mutex_unlock(&dirty_i->seglist_lock);
 826
 827        return ret;
 828}
 829
 830static const struct victim_selection default_v_ops = {
 831        .get_victim = get_victim_by_default,
 832};
 833
 834static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 835{
 836        struct inode_entry *ie;
 837
 838        ie = radix_tree_lookup(&gc_list->iroot, ino);
 839        if (ie)
 840                return ie->inode;
 841        return NULL;
 842}
 843
 844static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 845{
 846        struct inode_entry *new_ie;
 847
 848        if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 849                iput(inode);
 850                return;
 851        }
 852        new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 853        new_ie->inode = inode;
 854
 855        f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 856        list_add_tail(&new_ie->list, &gc_list->ilist);
 857}
 858
 859static void put_gc_inode(struct gc_inode_list *gc_list)
 860{
 861        struct inode_entry *ie, *next_ie;
 862
 863        list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 864                radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 865                iput(ie->inode);
 866                list_del(&ie->list);
 867                kmem_cache_free(f2fs_inode_entry_slab, ie);
 868        }
 869}
 870
 871static int check_valid_map(struct f2fs_sb_info *sbi,
 872                                unsigned int segno, int offset)
 873{
 874        struct sit_info *sit_i = SIT_I(sbi);
 875        struct seg_entry *sentry;
 876        int ret;
 877
 878        down_read(&sit_i->sentry_lock);
 879        sentry = get_seg_entry(sbi, segno);
 880        ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 881        up_read(&sit_i->sentry_lock);
 882        return ret;
 883}
 884
 885/*
 886 * This function compares node address got in summary with that in NAT.
 887 * On validity, copy that node with cold status, otherwise (invalid node)
 888 * ignore that.
 889 */
 890static int gc_node_segment(struct f2fs_sb_info *sbi,
 891                struct f2fs_summary *sum, unsigned int segno, int gc_type)
 892{
 893        struct f2fs_summary *entry;
 894        block_t start_addr;
 895        int off;
 896        int phase = 0;
 897        bool fggc = (gc_type == FG_GC);
 898        int submitted = 0;
 899        unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
 900
 901        start_addr = START_BLOCK(sbi, segno);
 902
 903next_step:
 904        entry = sum;
 905
 906        if (fggc && phase == 2)
 907                atomic_inc(&sbi->wb_sync_req[NODE]);
 908
 909        for (off = 0; off < usable_blks_in_seg; off++, entry++) {
 910                nid_t nid = le32_to_cpu(entry->nid);
 911                struct page *node_page;
 912                struct node_info ni;
 913                int err;
 914
 915                /* stop BG_GC if there is not enough free sections. */
 916                if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 917                        return submitted;
 918
 919                if (check_valid_map(sbi, segno, off) == 0)
 920                        continue;
 921
 922                if (phase == 0) {
 923                        f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 924                                                        META_NAT, true);
 925                        continue;
 926                }
 927
 928                if (phase == 1) {
 929                        f2fs_ra_node_page(sbi, nid);
 930                        continue;
 931                }
 932
 933                /* phase == 2 */
 934                node_page = f2fs_get_node_page(sbi, nid);
 935                if (IS_ERR(node_page))
 936                        continue;
 937
 938                /* block may become invalid during f2fs_get_node_page */
 939                if (check_valid_map(sbi, segno, off) == 0) {
 940                        f2fs_put_page(node_page, 1);
 941                        continue;
 942                }
 943
 944                if (f2fs_get_node_info(sbi, nid, &ni)) {
 945                        f2fs_put_page(node_page, 1);
 946                        continue;
 947                }
 948
 949                if (ni.blk_addr != start_addr + off) {
 950                        f2fs_put_page(node_page, 1);
 951                        continue;
 952                }
 953
 954                err = f2fs_move_node_page(node_page, gc_type);
 955                if (!err && gc_type == FG_GC)
 956                        submitted++;
 957                stat_inc_node_blk_count(sbi, 1, gc_type);
 958        }
 959
 960        if (++phase < 3)
 961                goto next_step;
 962
 963        if (fggc)
 964                atomic_dec(&sbi->wb_sync_req[NODE]);
 965        return submitted;
 966}
 967
 968/*
 969 * Calculate start block index indicating the given node offset.
 970 * Be careful, caller should give this node offset only indicating direct node
 971 * blocks. If any node offsets, which point the other types of node blocks such
 972 * as indirect or double indirect node blocks, are given, it must be a caller's
 973 * bug.
 974 */
 975block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 976{
 977        unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 978        unsigned int bidx;
 979
 980        if (node_ofs == 0)
 981                return 0;
 982
 983        if (node_ofs <= 2) {
 984                bidx = node_ofs - 1;
 985        } else if (node_ofs <= indirect_blks) {
 986                int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 987
 988                bidx = node_ofs - 2 - dec;
 989        } else {
 990                int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 991
 992                bidx = node_ofs - 5 - dec;
 993        }
 994        return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
 995}
 996
 997static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 998                struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 999{
1000        struct page *node_page;
1001        nid_t nid;
1002        unsigned int ofs_in_node;
1003        block_t source_blkaddr;
1004
1005        nid = le32_to_cpu(sum->nid);
1006        ofs_in_node = le16_to_cpu(sum->ofs_in_node);
1007
1008        node_page = f2fs_get_node_page(sbi, nid);
1009        if (IS_ERR(node_page))
1010                return false;
1011
1012        if (f2fs_get_node_info(sbi, nid, dni)) {
1013                f2fs_put_page(node_page, 1);
1014                return false;
1015        }
1016
1017        if (sum->version != dni->version) {
1018                f2fs_warn(sbi, "%s: valid data with mismatched node version.",
1019                          __func__);
1020                set_sbi_flag(sbi, SBI_NEED_FSCK);
1021        }
1022
1023        *nofs = ofs_of_node(node_page);
1024        source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
1025        f2fs_put_page(node_page, 1);
1026
1027        if (source_blkaddr != blkaddr) {
1028#ifdef CONFIG_F2FS_CHECK_FS
1029                unsigned int segno = GET_SEGNO(sbi, blkaddr);
1030                unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1031
1032                if (unlikely(check_valid_map(sbi, segno, offset))) {
1033                        if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
1034                                f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u",
1035                                         blkaddr, source_blkaddr, segno);
1036                                f2fs_bug_on(sbi, 1);
1037                        }
1038                }
1039#endif
1040                return false;
1041        }
1042        return true;
1043}
1044
1045static int ra_data_block(struct inode *inode, pgoff_t index)
1046{
1047        struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1048        struct address_space *mapping = inode->i_mapping;
1049        struct dnode_of_data dn;
1050        struct page *page;
1051        struct extent_info ei = {0, 0, 0};
1052        struct f2fs_io_info fio = {
1053                .sbi = sbi,
1054                .ino = inode->i_ino,
1055                .type = DATA,
1056                .temp = COLD,
1057                .op = REQ_OP_READ,
1058                .op_flags = 0,
1059                .encrypted_page = NULL,
1060                .in_list = false,
1061                .retry = false,
1062        };
1063        int err;
1064
1065        page = f2fs_grab_cache_page(mapping, index, true);
1066        if (!page)
1067                return -ENOMEM;
1068
1069        if (f2fs_lookup_extent_cache(inode, index, &ei)) {
1070                dn.data_blkaddr = ei.blk + index - ei.fofs;
1071                if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1072                                                DATA_GENERIC_ENHANCE_READ))) {
1073                        err = -EFSCORRUPTED;
1074                        goto put_page;
1075                }
1076                goto got_it;
1077        }
1078
1079        set_new_dnode(&dn, inode, NULL, NULL, 0);
1080        err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
1081        if (err)
1082                goto put_page;
1083        f2fs_put_dnode(&dn);
1084
1085        if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
1086                err = -ENOENT;
1087                goto put_page;
1088        }
1089        if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
1090                                                DATA_GENERIC_ENHANCE))) {
1091                err = -EFSCORRUPTED;
1092                goto put_page;
1093        }
1094got_it:
1095        /* read page */
1096        fio.page = page;
1097        fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1098
1099        /*
1100         * don't cache encrypted data into meta inode until previous dirty
1101         * data were writebacked to avoid racing between GC and flush.
1102         */
1103        f2fs_wait_on_page_writeback(page, DATA, true, true);
1104
1105        f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1106
1107        fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
1108                                        dn.data_blkaddr,
1109                                        FGP_LOCK | FGP_CREAT, GFP_NOFS);
1110        if (!fio.encrypted_page) {
1111                err = -ENOMEM;
1112                goto put_page;
1113        }
1114
1115        err = f2fs_submit_page_bio(&fio);
1116        if (err)
1117                goto put_encrypted_page;
1118        f2fs_put_page(fio.encrypted_page, 0);
1119        f2fs_put_page(page, 1);
1120
1121        f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1122        f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1123
1124        return 0;
1125put_encrypted_page:
1126        f2fs_put_page(fio.encrypted_page, 1);
1127put_page:
1128        f2fs_put_page(page, 1);
1129        return err;
1130}
1131
1132/*
1133 * Move data block via META_MAPPING while keeping locked data page.
1134 * This can be used to move blocks, aka LBAs, directly on disk.
1135 */
1136static int move_data_block(struct inode *inode, block_t bidx,
1137                                int gc_type, unsigned int segno, int off)
1138{
1139        struct f2fs_io_info fio = {
1140                .sbi = F2FS_I_SB(inode),
1141                .ino = inode->i_ino,
1142                .type = DATA,
1143                .temp = COLD,
1144                .op = REQ_OP_READ,
1145                .op_flags = 0,
1146                .encrypted_page = NULL,
1147                .in_list = false,
1148                .retry = false,
1149        };
1150        struct dnode_of_data dn;
1151        struct f2fs_summary sum;
1152        struct node_info ni;
1153        struct page *page, *mpage;
1154        block_t newaddr;
1155        int err = 0;
1156        bool lfs_mode = f2fs_lfs_mode(fio.sbi);
1157        int type = fio.sbi->am.atgc_enabled && (gc_type == BG_GC) &&
1158                                (fio.sbi->gc_mode != GC_URGENT_HIGH) ?
1159                                CURSEG_ALL_DATA_ATGC : CURSEG_COLD_DATA;
1160
1161        /* do not read out */
1162        page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
1163        if (!page)
1164                return -ENOMEM;
1165
1166        if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1167                err = -ENOENT;
1168                goto out;
1169        }
1170
1171        if (f2fs_is_atomic_file(inode)) {
1172                F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1173                F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1174                err = -EAGAIN;
1175                goto out;
1176        }
1177
1178        if (f2fs_is_pinned_file(inode)) {
1179                f2fs_pin_file_control(inode, true);
1180                err = -EAGAIN;
1181                goto out;
1182        }
1183
1184        set_new_dnode(&dn, inode, NULL, NULL, 0);
1185        err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
1186        if (err)
1187                goto out;
1188
1189        if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
1190                ClearPageUptodate(page);
1191                err = -ENOENT;
1192                goto put_out;
1193        }
1194
1195        /*
1196         * don't cache encrypted data into meta inode until previous dirty
1197         * data were writebacked to avoid racing between GC and flush.
1198         */
1199        f2fs_wait_on_page_writeback(page, DATA, true, true);
1200
1201        f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
1202
1203        err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
1204        if (err)
1205                goto put_out;
1206
1207        /* read page */
1208        fio.page = page;
1209        fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
1210
1211        if (lfs_mode)
1212                down_write(&fio.sbi->io_order_lock);
1213
1214        mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
1215                                        fio.old_blkaddr, false);
1216        if (!mpage) {
1217                err = -ENOMEM;
1218                goto up_out;
1219        }
1220
1221        fio.encrypted_page = mpage;
1222
1223        /* read source block in mpage */
1224        if (!PageUptodate(mpage)) {
1225                err = f2fs_submit_page_bio(&fio);
1226                if (err) {
1227                        f2fs_put_page(mpage, 1);
1228                        goto up_out;
1229                }
1230
1231                f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
1232                f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
1233
1234                lock_page(mpage);
1235                if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
1236                                                !PageUptodate(mpage))) {
1237                        err = -EIO;
1238                        f2fs_put_page(mpage, 1);
1239                        goto up_out;
1240                }
1241        }
1242
1243        set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
1244
1245        /* allocate block address */
1246        f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
1247                                &sum, type, NULL);
1248
1249        fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
1250                                newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
1251        if (!fio.encrypted_page) {
1252                err = -ENOMEM;
1253                f2fs_put_page(mpage, 1);
1254                goto recover_block;
1255        }
1256
1257        /* write target block */
1258        f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
1259        memcpy(page_address(fio.encrypted_page),
1260                                page_address(mpage), PAGE_SIZE);
1261        f2fs_put_page(mpage, 1);
1262        invalidate_mapping_pages(META_MAPPING(fio.sbi),
1263                                fio.old_blkaddr, fio.old_blkaddr);
1264        f2fs_invalidate_compress_page(fio.sbi, fio.old_blkaddr);
1265
1266        set_page_dirty(fio.encrypted_page);
1267        if (clear_page_dirty_for_io(fio.encrypted_page))
1268                dec_page_count(fio.sbi, F2FS_DIRTY_META);
1269
1270        set_page_writeback(fio.encrypted_page);
1271        ClearPageError(page);
1272
1273        fio.op = REQ_OP_WRITE;
1274        fio.op_flags = REQ_SYNC;
1275        fio.new_blkaddr = newaddr;
1276        f2fs_submit_page_write(&fio);
1277        if (fio.retry) {
1278                err = -EAGAIN;
1279                if (PageWriteback(fio.encrypted_page))
1280                        end_page_writeback(fio.encrypted_page);
1281                goto put_page_out;
1282        }
1283
1284        f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
1285
1286        f2fs_update_data_blkaddr(&dn, newaddr);
1287        set_inode_flag(inode, FI_APPEND_WRITE);
1288        if (page->index == 0)
1289                set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
1290put_page_out:
1291        f2fs_put_page(fio.encrypted_page, 1);
1292recover_block:
1293        if (err)
1294                f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
1295                                                        true, true, true);
1296up_out:
1297        if (lfs_mode)
1298                up_write(&fio.sbi->io_order_lock);
1299put_out:
1300        f2fs_put_dnode(&dn);
1301out:
1302        f2fs_put_page(page, 1);
1303        return err;
1304}
1305
1306static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
1307                                                        unsigned int segno, int off)
1308{
1309        struct page *page;
1310        int err = 0;
1311
1312        page = f2fs_get_lock_data_page(inode, bidx, true);
1313        if (IS_ERR(page))
1314                return PTR_ERR(page);
1315
1316        if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
1317                err = -ENOENT;
1318                goto out;
1319        }
1320
1321        if (f2fs_is_atomic_file(inode)) {
1322                F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
1323                F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
1324                err = -EAGAIN;
1325                goto out;
1326        }
1327        if (f2fs_is_pinned_file(inode)) {
1328                if (gc_type == FG_GC)
1329                        f2fs_pin_file_control(inode, true);
1330                err = -EAGAIN;
1331                goto out;
1332        }
1333
1334        if (gc_type == BG_GC) {
1335                if (PageWriteback(page)) {
1336                        err = -EAGAIN;
1337                        goto out;
1338                }
1339                set_page_dirty(page);
1340                set_page_private_gcing(page);
1341        } else {
1342                struct f2fs_io_info fio = {
1343                        .sbi = F2FS_I_SB(inode),
1344                        .ino = inode->i_ino,
1345                        .type = DATA,
1346                        .temp = COLD,
1347                        .op = REQ_OP_WRITE,
1348                        .op_flags = REQ_SYNC,
1349                        .old_blkaddr = NULL_ADDR,
1350                        .page = page,
1351                        .encrypted_page = NULL,
1352                        .need_lock = LOCK_REQ,
1353                        .io_type = FS_GC_DATA_IO,
1354                };
1355                bool is_dirty = PageDirty(page);
1356
1357retry:
1358                f2fs_wait_on_page_writeback(page, DATA, true, true);
1359
1360                set_page_dirty(page);
1361                if (clear_page_dirty_for_io(page)) {
1362                        inode_dec_dirty_pages(inode);
1363                        f2fs_remove_dirty_inode(inode);
1364                }
1365
1366                set_page_private_gcing(page);
1367
1368                err = f2fs_do_write_data_page(&fio);
1369                if (err) {
1370                        clear_page_private_gcing(page);
1371                        if (err == -ENOMEM) {
1372                                congestion_wait(BLK_RW_ASYNC,
1373                                                DEFAULT_IO_TIMEOUT);
1374                                goto retry;
1375                        }
1376                        if (is_dirty)
1377                                set_page_dirty(page);
1378                }
1379        }
1380out:
1381        f2fs_put_page(page, 1);
1382        return err;
1383}
1384
1385/*
1386 * This function tries to get parent node of victim data block, and identifies
1387 * data block validity. If the block is valid, copy that with cold status and
1388 * modify parent node.
1389 * If the parent node is not valid or the data block address is different,
1390 * the victim data block is ignored.
1391 */
1392static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1393                struct gc_inode_list *gc_list, unsigned int segno, int gc_type,
1394                bool force_migrate)
1395{
1396        struct super_block *sb = sbi->sb;
1397        struct f2fs_summary *entry;
1398        block_t start_addr;
1399        int off;
1400        int phase = 0;
1401        int submitted = 0;
1402        unsigned int usable_blks_in_seg = f2fs_usable_blks_in_seg(sbi, segno);
1403
1404        start_addr = START_BLOCK(sbi, segno);
1405
1406next_step:
1407        entry = sum;
1408
1409        for (off = 0; off < usable_blks_in_seg; off++, entry++) {
1410                struct page *data_page;
1411                struct inode *inode;
1412                struct node_info dni; /* dnode info for the data */
1413                unsigned int ofs_in_node, nofs;
1414                block_t start_bidx;
1415                nid_t nid = le32_to_cpu(entry->nid);
1416
1417                /*
1418                 * stop BG_GC if there is not enough free sections.
1419                 * Or, stop GC if the segment becomes fully valid caused by
1420                 * race condition along with SSR block allocation.
1421                 */
1422                if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1423                        (!force_migrate && get_valid_blocks(sbi, segno, true) ==
1424                                                        BLKS_PER_SEC(sbi)))
1425                        return submitted;
1426
1427                if (check_valid_map(sbi, segno, off) == 0)
1428                        continue;
1429
1430                if (phase == 0) {
1431                        f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1432                                                        META_NAT, true);
1433                        continue;
1434                }
1435
1436                if (phase == 1) {
1437                        f2fs_ra_node_page(sbi, nid);
1438                        continue;
1439                }
1440
1441                /* Get an inode by ino with checking validity */
1442                if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1443                        continue;
1444
1445                if (phase == 2) {
1446                        f2fs_ra_node_page(sbi, dni.ino);
1447                        continue;
1448                }
1449
1450                ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1451
1452                if (phase == 3) {
1453                        inode = f2fs_iget(sb, dni.ino);
1454                        if (IS_ERR(inode) || is_bad_inode(inode))
1455                                continue;
1456
1457                        if (!down_write_trylock(
1458                                &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1459                                iput(inode);
1460                                sbi->skipped_gc_rwsem++;
1461                                continue;
1462                        }
1463
1464                        start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1465                                                                ofs_in_node;
1466
1467                        if (f2fs_post_read_required(inode)) {
1468                                int err = ra_data_block(inode, start_bidx);
1469
1470                                up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1471                                if (err) {
1472                                        iput(inode);
1473                                        continue;
1474                                }
1475                                add_gc_inode(gc_list, inode);
1476                                continue;
1477                        }
1478
1479                        data_page = f2fs_get_read_data_page(inode,
1480                                                start_bidx, REQ_RAHEAD, true);
1481                        up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1482                        if (IS_ERR(data_page)) {
1483                                iput(inode);
1484                                continue;
1485                        }
1486
1487                        f2fs_put_page(data_page, 0);
1488                        add_gc_inode(gc_list, inode);
1489                        continue;
1490                }
1491
1492                /* phase 4 */
1493                inode = find_gc_inode(gc_list, dni.ino);
1494                if (inode) {
1495                        struct f2fs_inode_info *fi = F2FS_I(inode);
1496                        bool locked = false;
1497                        int err;
1498
1499                        if (S_ISREG(inode->i_mode)) {
1500                                if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1501                                        continue;
1502                                if (!down_write_trylock(
1503                                                &fi->i_gc_rwsem[WRITE])) {
1504                                        sbi->skipped_gc_rwsem++;
1505                                        up_write(&fi->i_gc_rwsem[READ]);
1506                                        continue;
1507                                }
1508                                locked = true;
1509
1510                                /* wait for all inflight aio data */
1511                                inode_dio_wait(inode);
1512                        }
1513
1514                        start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1515                                                                + ofs_in_node;
1516                        if (f2fs_post_read_required(inode))
1517                                err = move_data_block(inode, start_bidx,
1518                                                        gc_type, segno, off);
1519                        else
1520                                err = move_data_page(inode, start_bidx, gc_type,
1521                                                                segno, off);
1522
1523                        if (!err && (gc_type == FG_GC ||
1524                                        f2fs_post_read_required(inode)))
1525                                submitted++;
1526
1527                        if (locked) {
1528                                up_write(&fi->i_gc_rwsem[WRITE]);
1529                                up_write(&fi->i_gc_rwsem[READ]);
1530                        }
1531
1532                        stat_inc_data_blk_count(sbi, 1, gc_type);
1533                }
1534        }
1535
1536        if (++phase < 5)
1537                goto next_step;
1538
1539        return submitted;
1540}
1541
1542static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1543                        int gc_type)
1544{
1545        struct sit_info *sit_i = SIT_I(sbi);
1546        int ret;
1547
1548        down_write(&sit_i->sentry_lock);
1549        ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1550                                              NO_CHECK_TYPE, LFS, 0);
1551        up_write(&sit_i->sentry_lock);
1552        return ret;
1553}
1554
1555static int do_garbage_collect(struct f2fs_sb_info *sbi,
1556                                unsigned int start_segno,
1557                                struct gc_inode_list *gc_list, int gc_type,
1558                                bool force_migrate)
1559{
1560        struct page *sum_page;
1561        struct f2fs_summary_block *sum;
1562        struct blk_plug plug;
1563        unsigned int segno = start_segno;
1564        unsigned int end_segno = start_segno + sbi->segs_per_sec;
1565        int seg_freed = 0, migrated = 0;
1566        unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1567                                                SUM_TYPE_DATA : SUM_TYPE_NODE;
1568        int submitted = 0;
1569
1570        if (__is_large_section(sbi))
1571                end_segno = rounddown(end_segno, sbi->segs_per_sec);
1572
1573        /*
1574         * zone-capacity can be less than zone-size in zoned devices,
1575         * resulting in less than expected usable segments in the zone,
1576         * calculate the end segno in the zone which can be garbage collected
1577         */
1578        if (f2fs_sb_has_blkzoned(sbi))
1579                end_segno -= sbi->segs_per_sec -
1580                                        f2fs_usable_segs_in_sec(sbi, segno);
1581
1582        sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1583
1584        /* readahead multi ssa blocks those have contiguous address */
1585        if (__is_large_section(sbi))
1586                f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1587                                        end_segno - segno, META_SSA, true);
1588
1589        /* reference all summary page */
1590        while (segno < end_segno) {
1591                sum_page = f2fs_get_sum_page(sbi, segno++);
1592                if (IS_ERR(sum_page)) {
1593                        int err = PTR_ERR(sum_page);
1594
1595                        end_segno = segno - 1;
1596                        for (segno = start_segno; segno < end_segno; segno++) {
1597                                sum_page = find_get_page(META_MAPPING(sbi),
1598                                                GET_SUM_BLOCK(sbi, segno));
1599                                f2fs_put_page(sum_page, 0);
1600                                f2fs_put_page(sum_page, 0);
1601                        }
1602                        return err;
1603                }
1604                unlock_page(sum_page);
1605        }
1606
1607        blk_start_plug(&plug);
1608
1609        for (segno = start_segno; segno < end_segno; segno++) {
1610
1611                /* find segment summary of victim */
1612                sum_page = find_get_page(META_MAPPING(sbi),
1613                                        GET_SUM_BLOCK(sbi, segno));
1614                f2fs_put_page(sum_page, 0);
1615
1616                if (get_valid_blocks(sbi, segno, false) == 0)
1617                        goto freed;
1618                if (gc_type == BG_GC && __is_large_section(sbi) &&
1619                                migrated >= sbi->migration_granularity)
1620                        goto skip;
1621                if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1622                        goto skip;
1623
1624                sum = page_address(sum_page);
1625                if (type != GET_SUM_TYPE((&sum->footer))) {
1626                        f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1627                                 segno, type, GET_SUM_TYPE((&sum->footer)));
1628                        set_sbi_flag(sbi, SBI_NEED_FSCK);
1629                        f2fs_stop_checkpoint(sbi, false);
1630                        goto skip;
1631                }
1632
1633                /*
1634                 * this is to avoid deadlock:
1635                 * - lock_page(sum_page)         - f2fs_replace_block
1636                 *  - check_valid_map()            - down_write(sentry_lock)
1637                 *   - down_read(sentry_lock)     - change_curseg()
1638                 *                                  - lock_page(sum_page)
1639                 */
1640                if (type == SUM_TYPE_NODE)
1641                        submitted += gc_node_segment(sbi, sum->entries, segno,
1642                                                                gc_type);
1643                else
1644                        submitted += gc_data_segment(sbi, sum->entries, gc_list,
1645                                                        segno, gc_type,
1646                                                        force_migrate);
1647
1648                stat_inc_seg_count(sbi, type, gc_type);
1649                migrated++;
1650
1651freed:
1652                if (gc_type == FG_GC &&
1653                                get_valid_blocks(sbi, segno, false) == 0)
1654                        seg_freed++;
1655
1656                if (__is_large_section(sbi) && segno + 1 < end_segno)
1657                        sbi->next_victim_seg[gc_type] = segno + 1;
1658skip:
1659                f2fs_put_page(sum_page, 0);
1660        }
1661
1662        if (submitted)
1663                f2fs_submit_merged_write(sbi,
1664                                (type == SUM_TYPE_NODE) ? NODE : DATA);
1665
1666        blk_finish_plug(&plug);
1667
1668        stat_inc_call_count(sbi->stat_info);
1669
1670        return seg_freed;
1671}
1672
1673int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1674                        bool background, bool force, unsigned int segno)
1675{
1676        int gc_type = sync ? FG_GC : BG_GC;
1677        int sec_freed = 0, seg_freed = 0, total_freed = 0;
1678        int ret = 0;
1679        struct cp_control cpc;
1680        unsigned int init_segno = segno;
1681        struct gc_inode_list gc_list = {
1682                .ilist = LIST_HEAD_INIT(gc_list.ilist),
1683                .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1684        };
1685        unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1686        unsigned long long first_skipped;
1687        unsigned int skipped_round = 0, round = 0;
1688
1689        trace_f2fs_gc_begin(sbi->sb, sync, background,
1690                                get_pages(sbi, F2FS_DIRTY_NODES),
1691                                get_pages(sbi, F2FS_DIRTY_DENTS),
1692                                get_pages(sbi, F2FS_DIRTY_IMETA),
1693                                free_sections(sbi),
1694                                free_segments(sbi),
1695                                reserved_segments(sbi),
1696                                prefree_segments(sbi));
1697
1698        cpc.reason = __get_cp_reason(sbi);
1699        sbi->skipped_gc_rwsem = 0;
1700        first_skipped = last_skipped;
1701gc_more:
1702        if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1703                ret = -EINVAL;
1704                goto stop;
1705        }
1706        if (unlikely(f2fs_cp_error(sbi))) {
1707                ret = -EIO;
1708                goto stop;
1709        }
1710
1711        if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1712                /*
1713                 * For example, if there are many prefree_segments below given
1714                 * threshold, we can make them free by checkpoint. Then, we
1715                 * secure free segments which doesn't need fggc any more.
1716                 */
1717                if (prefree_segments(sbi) &&
1718                                !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1719                        ret = f2fs_write_checkpoint(sbi, &cpc);
1720                        if (ret)
1721                                goto stop;
1722                }
1723                if (has_not_enough_free_secs(sbi, 0, 0))
1724                        gc_type = FG_GC;
1725        }
1726
1727        /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1728        if (gc_type == BG_GC && !background) {
1729                ret = -EINVAL;
1730                goto stop;
1731        }
1732        ret = __get_victim(sbi, &segno, gc_type);
1733        if (ret)
1734                goto stop;
1735
1736        seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1737        if (gc_type == FG_GC &&
1738                seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1739                sec_freed++;
1740        total_freed += seg_freed;
1741
1742        if (gc_type == FG_GC) {
1743                if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1744                                                sbi->skipped_gc_rwsem)
1745                        skipped_round++;
1746                last_skipped = sbi->skipped_atomic_files[FG_GC];
1747                round++;
1748        }
1749
1750        if (gc_type == FG_GC && seg_freed)
1751                sbi->cur_victim_sec = NULL_SEGNO;
1752
1753        if (sync)
1754                goto stop;
1755
1756        if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1757                if (skipped_round <= MAX_SKIP_GC_COUNT ||
1758                                        skipped_round * 2 < round) {
1759                        segno = NULL_SEGNO;
1760                        goto gc_more;
1761                }
1762
1763                if (first_skipped < last_skipped &&
1764                                (last_skipped - first_skipped) >
1765                                                sbi->skipped_gc_rwsem) {
1766                        f2fs_drop_inmem_pages_all(sbi, true);
1767                        segno = NULL_SEGNO;
1768                        goto gc_more;
1769                }
1770                if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1771                        ret = f2fs_write_checkpoint(sbi, &cpc);
1772        }
1773stop:
1774        SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1775        SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1776
1777        trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1778                                get_pages(sbi, F2FS_DIRTY_NODES),
1779                                get_pages(sbi, F2FS_DIRTY_DENTS),
1780                                get_pages(sbi, F2FS_DIRTY_IMETA),
1781                                free_sections(sbi),
1782                                free_segments(sbi),
1783                                reserved_segments(sbi),
1784                                prefree_segments(sbi));
1785
1786        up_write(&sbi->gc_lock);
1787
1788        put_gc_inode(&gc_list);
1789
1790        if (sync && !ret)
1791                ret = sec_freed ? 0 : -EAGAIN;
1792        return ret;
1793}
1794
1795int __init f2fs_create_garbage_collection_cache(void)
1796{
1797        victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1798                                        sizeof(struct victim_entry));
1799        if (!victim_entry_slab)
1800                return -ENOMEM;
1801        return 0;
1802}
1803
1804void f2fs_destroy_garbage_collection_cache(void)
1805{
1806        kmem_cache_destroy(victim_entry_slab);
1807}
1808
1809static void init_atgc_management(struct f2fs_sb_info *sbi)
1810{
1811        struct atgc_management *am = &sbi->am;
1812
1813        if (test_opt(sbi, ATGC) &&
1814                SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1815                am->atgc_enabled = true;
1816
1817        am->root = RB_ROOT_CACHED;
1818        INIT_LIST_HEAD(&am->victim_list);
1819        am->victim_count = 0;
1820
1821        am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1822        am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1823        am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1824        am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1825}
1826
1827void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1828{
1829        DIRTY_I(sbi)->v_ops = &default_v_ops;
1830
1831        sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1832
1833        /* give warm/cold data area from slower device */
1834        if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1835                SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1836                                GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1837
1838        init_atgc_management(sbi);
1839}
1840
1841static int free_segment_range(struct f2fs_sb_info *sbi,
1842                                unsigned int secs, bool gc_only)
1843{
1844        unsigned int segno, next_inuse, start, end;
1845        struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1846        int gc_mode, gc_type;
1847        int err = 0;
1848        int type;
1849
1850        /* Force block allocation for GC */
1851        MAIN_SECS(sbi) -= secs;
1852        start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1853        end = MAIN_SEGS(sbi) - 1;
1854
1855        mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1856        for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1857                if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1858                        SIT_I(sbi)->last_victim[gc_mode] = 0;
1859
1860        for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1861                if (sbi->next_victim_seg[gc_type] >= start)
1862                        sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1863        mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1864
1865        /* Move out cursegs from the target range */
1866        for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1867                f2fs_allocate_segment_for_resize(sbi, type, start, end);
1868
1869        /* do GC to move out valid blocks in the range */
1870        for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1871                struct gc_inode_list gc_list = {
1872                        .ilist = LIST_HEAD_INIT(gc_list.ilist),
1873                        .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1874                };
1875
1876                do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1877                put_gc_inode(&gc_list);
1878
1879                if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1880                        err = -EAGAIN;
1881                        goto out;
1882                }
1883                if (fatal_signal_pending(current)) {
1884                        err = -ERESTARTSYS;
1885                        goto out;
1886                }
1887        }
1888        if (gc_only)
1889                goto out;
1890
1891        err = f2fs_write_checkpoint(sbi, &cpc);
1892        if (err)
1893                goto out;
1894
1895        next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1896        if (next_inuse <= end) {
1897                f2fs_err(sbi, "segno %u should be free but still inuse!",
1898                         next_inuse);
1899                f2fs_bug_on(sbi, 1);
1900        }
1901out:
1902        MAIN_SECS(sbi) += secs;
1903        return err;
1904}
1905
1906static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1907{
1908        struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1909        int section_count;
1910        int segment_count;
1911        int segment_count_main;
1912        long long block_count;
1913        int segs = secs * sbi->segs_per_sec;
1914
1915        down_write(&sbi->sb_lock);
1916
1917        section_count = le32_to_cpu(raw_sb->section_count);
1918        segment_count = le32_to_cpu(raw_sb->segment_count);
1919        segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1920        block_count = le64_to_cpu(raw_sb->block_count);
1921
1922        raw_sb->section_count = cpu_to_le32(section_count + secs);
1923        raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1924        raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1925        raw_sb->block_count = cpu_to_le64(block_count +
1926                                        (long long)segs * sbi->blocks_per_seg);
1927        if (f2fs_is_multi_device(sbi)) {
1928                int last_dev = sbi->s_ndevs - 1;
1929                int dev_segs =
1930                        le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1931
1932                raw_sb->devs[last_dev].total_segments =
1933                                                cpu_to_le32(dev_segs + segs);
1934        }
1935
1936        up_write(&sbi->sb_lock);
1937}
1938
1939static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1940{
1941        int segs = secs * sbi->segs_per_sec;
1942        long long blks = (long long)segs * sbi->blocks_per_seg;
1943        long long user_block_count =
1944                                le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1945
1946        SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1947        MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1948        MAIN_SECS(sbi) += secs;
1949        FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1950        FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1951        F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1952
1953        if (f2fs_is_multi_device(sbi)) {
1954                int last_dev = sbi->s_ndevs - 1;
1955
1956                FDEV(last_dev).total_segments =
1957                                (int)FDEV(last_dev).total_segments + segs;
1958                FDEV(last_dev).end_blk =
1959                                (long long)FDEV(last_dev).end_blk + blks;
1960#ifdef CONFIG_BLK_DEV_ZONED
1961                FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1962                                        (int)(blks >> sbi->log_blocks_per_blkz);
1963#endif
1964        }
1965}
1966
1967int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1968{
1969        __u64 old_block_count, shrunk_blocks;
1970        struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1971        unsigned int secs;
1972        int err = 0;
1973        __u32 rem;
1974
1975        old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1976        if (block_count > old_block_count)
1977                return -EINVAL;
1978
1979        if (f2fs_is_multi_device(sbi)) {
1980                int last_dev = sbi->s_ndevs - 1;
1981                __u64 last_segs = FDEV(last_dev).total_segments;
1982
1983                if (block_count + last_segs * sbi->blocks_per_seg <=
1984                                                                old_block_count)
1985                        return -EINVAL;
1986        }
1987
1988        /* new fs size should align to section size */
1989        div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
1990        if (rem)
1991                return -EINVAL;
1992
1993        if (block_count == old_block_count)
1994                return 0;
1995
1996        if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1997                f2fs_err(sbi, "Should run fsck to repair first.");
1998                return -EFSCORRUPTED;
1999        }
2000
2001        if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2002                f2fs_err(sbi, "Checkpoint should be enabled.");
2003                return -EINVAL;
2004        }
2005
2006        shrunk_blocks = old_block_count - block_count;
2007        secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2008
2009        /* stop other GC */
2010        if (!down_write_trylock(&sbi->gc_lock))
2011                return -EAGAIN;
2012
2013        /* stop CP to protect MAIN_SEC in free_segment_range */
2014        f2fs_lock_op(sbi);
2015
2016        spin_lock(&sbi->stat_lock);
2017        if (shrunk_blocks + valid_user_blocks(sbi) +
2018                sbi->current_reserved_blocks + sbi->unusable_block_count +
2019                F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2020                err = -ENOSPC;
2021        spin_unlock(&sbi->stat_lock);
2022
2023        if (err)
2024                goto out_unlock;
2025
2026        err = free_segment_range(sbi, secs, true);
2027
2028out_unlock:
2029        f2fs_unlock_op(sbi);
2030        up_write(&sbi->gc_lock);
2031        if (err)
2032                return err;
2033
2034        set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2035
2036        freeze_super(sbi->sb);
2037        down_write(&sbi->gc_lock);
2038        down_write(&sbi->cp_global_sem);
2039
2040        spin_lock(&sbi->stat_lock);
2041        if (shrunk_blocks + valid_user_blocks(sbi) +
2042                sbi->current_reserved_blocks + sbi->unusable_block_count +
2043                F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2044                err = -ENOSPC;
2045        else
2046                sbi->user_block_count -= shrunk_blocks;
2047        spin_unlock(&sbi->stat_lock);
2048        if (err)
2049                goto out_err;
2050
2051        err = free_segment_range(sbi, secs, false);
2052        if (err)
2053                goto recover_out;
2054
2055        update_sb_metadata(sbi, -secs);
2056
2057        err = f2fs_commit_super(sbi, false);
2058        if (err) {
2059                update_sb_metadata(sbi, secs);
2060                goto recover_out;
2061        }
2062
2063        update_fs_metadata(sbi, -secs);
2064        clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2065        set_sbi_flag(sbi, SBI_IS_DIRTY);
2066
2067        err = f2fs_write_checkpoint(sbi, &cpc);
2068        if (err) {
2069                update_fs_metadata(sbi, secs);
2070                update_sb_metadata(sbi, secs);
2071                f2fs_commit_super(sbi, false);
2072        }
2073recover_out:
2074        if (err) {
2075                set_sbi_flag(sbi, SBI_NEED_FSCK);
2076                f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2077
2078                spin_lock(&sbi->stat_lock);
2079                sbi->user_block_count += shrunk_blocks;
2080                spin_unlock(&sbi->stat_lock);
2081        }
2082out_err:
2083        up_write(&sbi->cp_global_sem);
2084        up_write(&sbi->gc_lock);
2085        thaw_super(sbi->sb);
2086        clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2087        return err;
2088}
2089
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