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					sbi->skipped_gc_rwsem++;
1502					continue;
1503				}
1504				if (!down_write_trylock(
1505						&fi->i_gc_rwsem[WRITE])) {
1506					sbi->skipped_gc_rwsem++;
1507					up_write(&fi->i_gc_rwsem[READ]);
1508					continue;
1509				}
1510				locked = true;
1511
1512				/* wait for all inflight aio data */
1513				inode_dio_wait(inode);
1514			}
1515
1516			start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1517								+ ofs_in_node;
1518			if (f2fs_post_read_required(inode))
1519				err = move_data_block(inode, start_bidx,
1520							gc_type, segno, off);
1521			else
1522				err = move_data_page(inode, start_bidx, gc_type,
1523								segno, off);
1524
1525			if (!err && (gc_type == FG_GC ||
1526					f2fs_post_read_required(inode)))
1527				submitted++;
1528
1529			if (locked) {
1530				up_write(&fi->i_gc_rwsem[WRITE]);
1531				up_write(&fi->i_gc_rwsem[READ]);
1532			}
1533
1534			stat_inc_data_blk_count(sbi, 1, gc_type);
1535		}
1536	}
1537
1538	if (++phase < 5)
1539		goto next_step;
1540
1541	return submitted;
1542}
1543
1544static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1545			int gc_type)
1546{
1547	struct sit_info *sit_i = SIT_I(sbi);
1548	int ret;
1549
1550	down_write(&sit_i->sentry_lock);
1551	ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1552					      NO_CHECK_TYPE, LFS, 0);
1553	up_write(&sit_i->sentry_lock);
1554	return ret;
1555}
1556
1557static int do_garbage_collect(struct f2fs_sb_info *sbi,
1558				unsigned int start_segno,
1559				struct gc_inode_list *gc_list, int gc_type,
1560				bool force_migrate)
1561{
1562	struct page *sum_page;
1563	struct f2fs_summary_block *sum;
1564	struct blk_plug plug;
1565	unsigned int segno = start_segno;
1566	unsigned int end_segno = start_segno + sbi->segs_per_sec;
1567	int seg_freed = 0, migrated = 0;
1568	unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1569						SUM_TYPE_DATA : SUM_TYPE_NODE;
1570	int submitted = 0;
1571
1572	if (__is_large_section(sbi))
1573		end_segno = rounddown(end_segno, sbi->segs_per_sec);
1574
1575	/*
1576	 * zone-capacity can be less than zone-size in zoned devices,
1577	 * resulting in less than expected usable segments in the zone,
1578	 * calculate the end segno in the zone which can be garbage collected
1579	 */
1580	if (f2fs_sb_has_blkzoned(sbi))
1581		end_segno -= sbi->segs_per_sec -
1582					f2fs_usable_segs_in_sec(sbi, segno);
1583
1584	sanity_check_seg_type(sbi, get_seg_entry(sbi, segno)->type);
1585
1586	/* readahead multi ssa blocks those have contiguous address */
1587	if (__is_large_section(sbi))
1588		f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1589					end_segno - segno, META_SSA, true);
1590
1591	/* reference all summary page */
1592	while (segno < end_segno) {
1593		sum_page = f2fs_get_sum_page(sbi, segno++);
1594		if (IS_ERR(sum_page)) {
1595			int err = PTR_ERR(sum_page);
1596
1597			end_segno = segno - 1;
1598			for (segno = start_segno; segno < end_segno; segno++) {
1599				sum_page = find_get_page(META_MAPPING(sbi),
1600						GET_SUM_BLOCK(sbi, segno));
1601				f2fs_put_page(sum_page, 0);
1602				f2fs_put_page(sum_page, 0);
1603			}
1604			return err;
1605		}
1606		unlock_page(sum_page);
1607	}
1608
1609	blk_start_plug(&plug);
1610
1611	for (segno = start_segno; segno < end_segno; segno++) {
1612
1613		/* find segment summary of victim */
1614		sum_page = find_get_page(META_MAPPING(sbi),
1615					GET_SUM_BLOCK(sbi, segno));
1616		f2fs_put_page(sum_page, 0);
1617
1618		if (get_valid_blocks(sbi, segno, false) == 0)
1619			goto freed;
1620		if (gc_type == BG_GC && __is_large_section(sbi) &&
1621				migrated >= sbi->migration_granularity)
1622			goto skip;
1623		if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1624			goto skip;
1625
1626		sum = page_address(sum_page);
1627		if (type != GET_SUM_TYPE((&sum->footer))) {
1628			f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1629				 segno, type, GET_SUM_TYPE((&sum->footer)));
1630			set_sbi_flag(sbi, SBI_NEED_FSCK);
1631			f2fs_stop_checkpoint(sbi, false);
 
1632			goto skip;
1633		}
1634
1635		/*
1636		 * this is to avoid deadlock:
1637		 * - lock_page(sum_page)         - f2fs_replace_block
1638		 *  - check_valid_map()            - down_write(sentry_lock)
1639		 *   - down_read(sentry_lock)     - change_curseg()
1640		 *                                  - lock_page(sum_page)
1641		 */
1642		if (type == SUM_TYPE_NODE)
1643			submitted += gc_node_segment(sbi, sum->entries, segno,
1644								gc_type);
1645		else
1646			submitted += gc_data_segment(sbi, sum->entries, gc_list,
1647							segno, gc_type,
1648							force_migrate);
1649
1650		stat_inc_seg_count(sbi, type, gc_type);
 
1651		migrated++;
1652
1653freed:
1654		if (gc_type == FG_GC &&
1655				get_valid_blocks(sbi, segno, false) == 0)
1656			seg_freed++;
1657
1658		if (__is_large_section(sbi) && segno + 1 < end_segno)
1659			sbi->next_victim_seg[gc_type] = segno + 1;
 
1660skip:
1661		f2fs_put_page(sum_page, 0);
1662	}
1663
1664	if (submitted)
1665		f2fs_submit_merged_write(sbi,
1666				(type == SUM_TYPE_NODE) ? NODE : DATA);
1667
1668	blk_finish_plug(&plug);
1669
1670	stat_inc_call_count(sbi->stat_info);
1671
1672	return seg_freed;
1673}
1674
1675int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1676			bool background, bool force, unsigned int segno)
1677{
1678	int gc_type = sync ? FG_GC : BG_GC;
 
1679	int sec_freed = 0, seg_freed = 0, total_freed = 0;
1680	int ret = 0;
1681	struct cp_control cpc;
1682	unsigned int init_segno = segno;
1683	struct gc_inode_list gc_list = {
1684		.ilist = LIST_HEAD_INIT(gc_list.ilist),
1685		.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1686	};
1687	unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1688	unsigned long long first_skipped;
1689	unsigned int skipped_round = 0, round = 0;
1690
1691	trace_f2fs_gc_begin(sbi->sb, sync, background,
 
1692				get_pages(sbi, F2FS_DIRTY_NODES),
1693				get_pages(sbi, F2FS_DIRTY_DENTS),
1694				get_pages(sbi, F2FS_DIRTY_IMETA),
1695				free_sections(sbi),
1696				free_segments(sbi),
1697				reserved_segments(sbi),
1698				prefree_segments(sbi));
1699
1700	cpc.reason = __get_cp_reason(sbi);
1701	sbi->skipped_gc_rwsem = 0;
1702	first_skipped = last_skipped;
1703gc_more:
1704	if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1705		ret = -EINVAL;
1706		goto stop;
1707	}
1708	if (unlikely(f2fs_cp_error(sbi))) {
1709		ret = -EIO;
1710		goto stop;
1711	}
1712
1713	if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1714		/*
1715		 * For example, if there are many prefree_segments below given
1716		 * threshold, we can make them free by checkpoint. Then, we
1717		 * secure free segments which doesn't need fggc any more.
1718		 */
1719		if (prefree_segments(sbi) &&
1720				!is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1721			ret = f2fs_write_checkpoint(sbi, &cpc);
1722			if (ret)
1723				goto stop;
1724		}
1725		if (has_not_enough_free_secs(sbi, 0, 0))
1726			gc_type = FG_GC;
1727	}
1728
1729	/* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1730	if (gc_type == BG_GC && !background) {
1731		ret = -EINVAL;
1732		goto stop;
1733	}
 
1734	ret = __get_victim(sbi, &segno, gc_type);
1735	if (ret)
 
 
 
 
 
 
1736		goto stop;
 
1737
1738	seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type, force);
1739	if (gc_type == FG_GC &&
1740		seg_freed == f2fs_usable_segs_in_sec(sbi, segno))
1741		sec_freed++;
1742	total_freed += seg_freed;
1743
1744	if (gc_type == FG_GC) {
1745		if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1746						sbi->skipped_gc_rwsem)
1747			skipped_round++;
1748		last_skipped = sbi->skipped_atomic_files[FG_GC];
1749		round++;
1750	}
1751
1752	if (gc_type == FG_GC && seg_freed)
1753		sbi->cur_victim_sec = NULL_SEGNO;
1754
1755	if (sync)
 
 
 
 
1756		goto stop;
 
1757
1758	if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1759		if (skipped_round <= MAX_SKIP_GC_COUNT ||
1760					skipped_round * 2 < round) {
1761			segno = NULL_SEGNO;
1762			goto gc_more;
 
 
 
 
1763		}
 
1764
1765		if (first_skipped < last_skipped &&
1766				(last_skipped - first_skipped) >
1767						sbi->skipped_gc_rwsem) {
1768			f2fs_drop_inmem_pages_all(sbi, true);
1769			segno = NULL_SEGNO;
1770			goto gc_more;
1771		}
1772		if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1773			ret = f2fs_write_checkpoint(sbi, &cpc);
1774	}
 
 
 
 
1775stop:
1776	SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1777	SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
 
 
 
1778
1779	trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1780				get_pages(sbi, F2FS_DIRTY_NODES),
1781				get_pages(sbi, F2FS_DIRTY_DENTS),
1782				get_pages(sbi, F2FS_DIRTY_IMETA),
1783				free_sections(sbi),
1784				free_segments(sbi),
1785				reserved_segments(sbi),
1786				prefree_segments(sbi));
1787
1788	up_write(&sbi->gc_lock);
1789
1790	put_gc_inode(&gc_list);
1791
1792	if (sync && !ret)
1793		ret = sec_freed ? 0 : -EAGAIN;
1794	return ret;
1795}
1796
1797int __init f2fs_create_garbage_collection_cache(void)
1798{
1799	victim_entry_slab = f2fs_kmem_cache_create("f2fs_victim_entry",
1800					sizeof(struct victim_entry));
1801	if (!victim_entry_slab)
1802		return -ENOMEM;
1803	return 0;
1804}
1805
1806void f2fs_destroy_garbage_collection_cache(void)
1807{
1808	kmem_cache_destroy(victim_entry_slab);
1809}
1810
1811static void init_atgc_management(struct f2fs_sb_info *sbi)
1812{
1813	struct atgc_management *am = &sbi->am;
1814
1815	if (test_opt(sbi, ATGC) &&
1816		SIT_I(sbi)->elapsed_time >= DEF_GC_THREAD_AGE_THRESHOLD)
1817		am->atgc_enabled = true;
1818
1819	am->root = RB_ROOT_CACHED;
1820	INIT_LIST_HEAD(&am->victim_list);
1821	am->victim_count = 0;
1822
1823	am->candidate_ratio = DEF_GC_THREAD_CANDIDATE_RATIO;
1824	am->max_candidate_count = DEF_GC_THREAD_MAX_CANDIDATE_COUNT;
1825	am->age_weight = DEF_GC_THREAD_AGE_WEIGHT;
1826	am->age_threshold = DEF_GC_THREAD_AGE_THRESHOLD;
1827}
1828
1829void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1830{
1831	DIRTY_I(sbi)->v_ops = &default_v_ops;
1832
1833	sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1834
1835	/* give warm/cold data area from slower device */
1836	if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1837		SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1838				GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1839
1840	init_atgc_management(sbi);
1841}
1842
1843static int free_segment_range(struct f2fs_sb_info *sbi,
1844				unsigned int secs, bool gc_only)
1845{
1846	unsigned int segno, next_inuse, start, end;
1847	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1848	int gc_mode, gc_type;
1849	int err = 0;
1850	int type;
1851
1852	/* Force block allocation for GC */
1853	MAIN_SECS(sbi) -= secs;
1854	start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1855	end = MAIN_SEGS(sbi) - 1;
1856
1857	mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1858	for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1859		if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1860			SIT_I(sbi)->last_victim[gc_mode] = 0;
1861
1862	for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1863		if (sbi->next_victim_seg[gc_type] >= start)
1864			sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1865	mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1866
1867	/* Move out cursegs from the target range */
1868	for (type = CURSEG_HOT_DATA; type < NR_CURSEG_PERSIST_TYPE; type++)
1869		f2fs_allocate_segment_for_resize(sbi, type, start, end);
1870
1871	/* do GC to move out valid blocks in the range */
1872	for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1873		struct gc_inode_list gc_list = {
1874			.ilist = LIST_HEAD_INIT(gc_list.ilist),
1875			.iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1876		};
1877
1878		do_garbage_collect(sbi, segno, &gc_list, FG_GC, true);
1879		put_gc_inode(&gc_list);
1880
1881		if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1882			err = -EAGAIN;
1883			goto out;
1884		}
1885		if (fatal_signal_pending(current)) {
1886			err = -ERESTARTSYS;
1887			goto out;
1888		}
1889	}
1890	if (gc_only)
1891		goto out;
1892
1893	err = f2fs_write_checkpoint(sbi, &cpc);
1894	if (err)
1895		goto out;
1896
1897	next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1898	if (next_inuse <= end) {
1899		f2fs_err(sbi, "segno %u should be free but still inuse!",
1900			 next_inuse);
1901		f2fs_bug_on(sbi, 1);
1902	}
1903out:
1904	MAIN_SECS(sbi) += secs;
1905	return err;
1906}
1907
1908static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1909{
1910	struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1911	int section_count;
1912	int segment_count;
1913	int segment_count_main;
1914	long long block_count;
1915	int segs = secs * sbi->segs_per_sec;
1916
1917	down_write(&sbi->sb_lock);
1918
1919	section_count = le32_to_cpu(raw_sb->section_count);
1920	segment_count = le32_to_cpu(raw_sb->segment_count);
1921	segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1922	block_count = le64_to_cpu(raw_sb->block_count);
1923
1924	raw_sb->section_count = cpu_to_le32(section_count + secs);
1925	raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1926	raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1927	raw_sb->block_count = cpu_to_le64(block_count +
1928					(long long)segs * sbi->blocks_per_seg);
1929	if (f2fs_is_multi_device(sbi)) {
1930		int last_dev = sbi->s_ndevs - 1;
1931		int dev_segs =
1932			le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1933
1934		raw_sb->devs[last_dev].total_segments =
1935						cpu_to_le32(dev_segs + segs);
1936	}
1937
1938	up_write(&sbi->sb_lock);
1939}
1940
1941static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1942{
1943	int segs = secs * sbi->segs_per_sec;
1944	long long blks = (long long)segs * sbi->blocks_per_seg;
1945	long long user_block_count =
1946				le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1947
1948	SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1949	MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1950	MAIN_SECS(sbi) += secs;
1951	FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1952	FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1953	F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1954
1955	if (f2fs_is_multi_device(sbi)) {
1956		int last_dev = sbi->s_ndevs - 1;
1957
1958		FDEV(last_dev).total_segments =
1959				(int)FDEV(last_dev).total_segments + segs;
1960		FDEV(last_dev).end_blk =
1961				(long long)FDEV(last_dev).end_blk + blks;
1962#ifdef CONFIG_BLK_DEV_ZONED
1963		FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1964					(int)(blks >> sbi->log_blocks_per_blkz);
1965#endif
1966	}
1967}
1968
1969int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1970{
1971	__u64 old_block_count, shrunk_blocks;
1972	struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1973	unsigned int secs;
1974	int err = 0;
1975	__u32 rem;
1976
1977	old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1978	if (block_count > old_block_count)
1979		return -EINVAL;
1980
1981	if (f2fs_is_multi_device(sbi)) {
1982		int last_dev = sbi->s_ndevs - 1;
1983		__u64 last_segs = FDEV(last_dev).total_segments;
1984
1985		if (block_count + last_segs * sbi->blocks_per_seg <=
1986								old_block_count)
1987			return -EINVAL;
1988	}
1989
1990	/* new fs size should align to section size */
1991	div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
1992	if (rem)
1993		return -EINVAL;
1994
1995	if (block_count == old_block_count)
1996		return 0;
1997
1998	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1999		f2fs_err(sbi, "Should run fsck to repair first.");
2000		return -EFSCORRUPTED;
2001	}
2002
2003	if (test_opt(sbi, DISABLE_CHECKPOINT)) {
2004		f2fs_err(sbi, "Checkpoint should be enabled.");
2005		return -EINVAL;
2006	}
2007
2008	shrunk_blocks = old_block_count - block_count;
2009	secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
2010
2011	/* stop other GC */
2012	if (!down_write_trylock(&sbi->gc_lock))
2013		return -EAGAIN;
2014
2015	/* stop CP to protect MAIN_SEC in free_segment_range */
2016	f2fs_lock_op(sbi);
2017
2018	spin_lock(&sbi->stat_lock);
2019	if (shrunk_blocks + valid_user_blocks(sbi) +
2020		sbi->current_reserved_blocks + sbi->unusable_block_count +
2021		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2022		err = -ENOSPC;
2023	spin_unlock(&sbi->stat_lock);
2024
2025	if (err)
2026		goto out_unlock;
2027
2028	err = free_segment_range(sbi, secs, true);
2029
2030out_unlock:
2031	f2fs_unlock_op(sbi);
2032	up_write(&sbi->gc_lock);
2033	if (err)
2034		return err;
2035
2036	set_sbi_flag(sbi, SBI_IS_RESIZEFS);
2037
2038	freeze_super(sbi->sb);
2039	down_write(&sbi->gc_lock);
2040	down_write(&sbi->cp_global_sem);
2041
2042	spin_lock(&sbi->stat_lock);
2043	if (shrunk_blocks + valid_user_blocks(sbi) +
2044		sbi->current_reserved_blocks + sbi->unusable_block_count +
2045		F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
2046		err = -ENOSPC;
2047	else
2048		sbi->user_block_count -= shrunk_blocks;
2049	spin_unlock(&sbi->stat_lock);
2050	if (err)
2051		goto out_err;
2052
 
2053	err = free_segment_range(sbi, secs, false);
2054	if (err)
2055		goto recover_out;
2056
2057	update_sb_metadata(sbi, -secs);
2058
2059	err = f2fs_commit_super(sbi, false);
2060	if (err) {
2061		update_sb_metadata(sbi, secs);
2062		goto recover_out;
2063	}
2064
2065	update_fs_metadata(sbi, -secs);
2066	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2067	set_sbi_flag(sbi, SBI_IS_DIRTY);
2068
2069	err = f2fs_write_checkpoint(sbi, &cpc);
2070	if (err) {
2071		update_fs_metadata(sbi, secs);
2072		update_sb_metadata(sbi, secs);
2073		f2fs_commit_super(sbi, false);
2074	}
2075recover_out:
 
2076	if (err) {
2077		set_sbi_flag(sbi, SBI_NEED_FSCK);
2078		f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
2079
2080		spin_lock(&sbi->stat_lock);
2081		sbi->user_block_count += shrunk_blocks;
2082		spin_unlock(&sbi->stat_lock);
2083	}
2084out_err:
2085	up_write(&sbi->cp_global_sem);
2086	up_write(&sbi->gc_lock);
2087	thaw_super(sbi->sb);
2088	clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
2089	return err;
2090}