fs/f2fs/gc.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 /*
   3  * fs/f2fs/gc.c
   4  *
   5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   6  *             http://www.samsung.com/
   7  */
   8 #include <linux/fs.h>
   9 #include <linux/module.h>
  10 #include <linux/backing-dev.h>
  11 #include <linux/init.h>
  12 #include <linux/f2fs_fs.h>
  13 #include <linux/kthread.h>
  14 #include <linux/delay.h>
  15 #include <linux/freezer.h>
  16 #include <linux/sched/signal.h>
  17
  18 #include "f2fs.h"
  19 #include "node.h"
  20 #include "segment.h"
  21 #include "gc.h"
  22 #include <trace/events/f2fs.h>
  23
  24 static int gc_thread_func(void *data)
  25 {
  26         struct f2fs_sb_info *sbi = data;
  27         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  28         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  29         unsigned int wait_ms;
  30
  31         wait_ms = gc_th->min_sleep_time;
  32
  33         set_freezable();
  34         do {
  35                 bool sync_mode;
  36
  37                 wait_event_interruptible_timeout(*wq,
  38                                 kthread_should_stop() || freezing(current) ||
  39                                 gc_th->gc_wake,
  40                                 msecs_to_jiffies(wait_ms));
  41
  42                 /* give it a try one time */
  43                 if (gc_th->gc_wake)
  44                         gc_th->gc_wake = 0;
  45
  46                 if (try_to_freeze()) {
  47                         stat_other_skip_bggc_count(sbi);
  48                         continue;
  49                 }
  50                 if (kthread_should_stop())
  51                         break;
  52
  53                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  54                         increase_sleep_time(gc_th, &wait_ms);
  55                         stat_other_skip_bggc_count(sbi);
  56                         continue;
  57                 }
  58
  59                 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  60                         f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  61                         f2fs_stop_checkpoint(sbi, false);
  62                 }
  63
  64                 if (!sb_start_write_trylock(sbi->sb)) {
  65                         stat_other_skip_bggc_count(sbi);
  66                         continue;
  67                 }
  68
  69                 /*
  70                  * [GC triggering condition]
  71                  * 0. GC is not conducted currently.
  72                  * 1. There are enough dirty segments.
  73                  * 2. IO subsystem is idle by checking the # of writeback pages.
  74                  * 3. IO subsystem is idle by checking the # of requests in
  75                  *    bdev's request list.
  76                  *
  77                  * Note) We have to avoid triggering GCs frequently.
  78                  * Because it is possible that some segments can be
  79                  * invalidated soon after by user update or deletion.
  80                  * So, I'd like to wait some time to collect dirty segments.
  81                  */
  82                 if (sbi->gc_mode == GC_URGENT) {
  83                         wait_ms = gc_th->urgent_sleep_time;
  84                         down_write(&sbi->gc_lock);
  85                         goto do_gc;
  86                 }
  87
  88                 if (!down_write_trylock(&sbi->gc_lock)) {
  89                         stat_other_skip_bggc_count(sbi);
  90                         goto next;
  91                 }
  92
  93                 if (!is_idle(sbi, GC_TIME)) {
  94                         increase_sleep_time(gc_th, &wait_ms);
  95                         up_write(&sbi->gc_lock);
  96                         stat_io_skip_bggc_count(sbi);
  97                         goto next;
  98                 }
  99
 100                 if (has_enough_invalid_blocks(sbi))
 101                         decrease_sleep_time(gc_th, &wait_ms);
 102                 else
 103                         increase_sleep_time(gc_th, &wait_ms);
 104 do_gc:
 105                 stat_inc_bggc_count(sbi->stat_info);
 106
 107                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 108
 109                 /* if return value is not zero, no victim was selected */
 110                 if (f2fs_gc(sbi, sync_mode, true, NULL_SEGNO))
 111                         wait_ms = gc_th->no_gc_sleep_time;
 112
 113                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 114                                 prefree_segments(sbi), free_segments(sbi));
 115
 116                 /* balancing f2fs's metadata periodically */
 117                 f2fs_balance_fs_bg(sbi, true);
 118 next:
 119                 sb_end_write(sbi->sb);
 120
 121         } while (!kthread_should_stop());
 122         return 0;
 123 }
 124
 125 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 126 {
 127         struct f2fs_gc_kthread *gc_th;
 128         dev_t dev = sbi->sb->s_bdev->bd_dev;
 129         int err = 0;
 130
 131         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 132         if (!gc_th) {
 133                 err = -ENOMEM;
 134                 goto out;
 135         }
 136
 137         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 138         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 139         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 140         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 141
 142         gc_th->gc_wake= 0;
 143
 144         sbi->gc_thread = gc_th;
 145         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 146         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 147                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 148         if (IS_ERR(gc_th->f2fs_gc_task)) {
 149                 err = PTR_ERR(gc_th->f2fs_gc_task);
 150                 kvfree(gc_th);
 151                 sbi->gc_thread = NULL;
 152         }
 153 out:
 154         return err;
 155 }
 156
 157 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 158 {
 159         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 160         if (!gc_th)
 161                 return;
 162         kthread_stop(gc_th->f2fs_gc_task);
 163         kvfree(gc_th);
 164         sbi->gc_thread = NULL;
 165 }
 166
 167 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 168 {
 169         int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
 170
 171         switch (sbi->gc_mode) {
 172         case GC_IDLE_CB:
 173                 gc_mode = GC_CB;
 174                 break;
 175         case GC_IDLE_GREEDY:
 176         case GC_URGENT:
 177                 gc_mode = GC_GREEDY;
 178                 break;
 179         }
 180         return gc_mode;
 181 }
 182
 183 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 184                         int type, struct victim_sel_policy *p)
 185 {
 186         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 187
 188         if (p->alloc_mode == SSR) {
 189                 p->gc_mode = GC_GREEDY;
 190                 p->dirty_segmap = dirty_i->dirty_segmap[type];
 191                 p->max_search = dirty_i->nr_dirty[type];
 192                 p->ofs_unit = 1;
 193         } else {
 194                 p->gc_mode = select_gc_type(sbi, gc_type);
 195                 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
 196                 p->max_search = dirty_i->nr_dirty[DIRTY];
 197                 p->ofs_unit = sbi->segs_per_sec;
 198         }
 199
 200         /*
 201          * adjust candidates range, should select all dirty segments for
 202          * foreground GC and urgent GC cases.
 203          */
 204         if (gc_type != FG_GC &&
 205                         (sbi->gc_mode != GC_URGENT) &&
 206                         p->max_search > sbi->max_victim_search)
 207                 p->max_search = sbi->max_victim_search;
 208
 209         /* let's select beginning hot/small space first in no_heap mode*/
 210         if (test_opt(sbi, NOHEAP) &&
 211                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 212                 p->offset = 0;
 213         else
 214                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 215 }
 216
 217 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 218                                 struct victim_sel_policy *p)
 219 {
 220         /* SSR allocates in a segment unit */
 221         if (p->alloc_mode == SSR)
 222                 return sbi->blocks_per_seg;
 223         if (p->gc_mode == GC_GREEDY)
 224                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 225         else if (p->gc_mode == GC_CB)
 226                 return UINT_MAX;
 227         else /* No other gc_mode */
 228                 return 0;
 229 }
 230
 231 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 232 {
 233         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 234         unsigned int secno;
 235
 236         /*
 237          * If the gc_type is FG_GC, we can select victim segments
 238          * selected by background GC before.
 239          * Those segments guarantee they have small valid blocks.
 240          */
 241         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 242                 if (sec_usage_check(sbi, secno))
 243                         continue;
 244                 clear_bit(secno, dirty_i->victim_secmap);
 245                 return GET_SEG_FROM_SEC(sbi, secno);
 246         }
 247         return NULL_SEGNO;
 248 }
 249
 250 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 251 {
 252         struct sit_info *sit_i = SIT_I(sbi);
 253         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 254         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 255         unsigned long long mtime = 0;
 256         unsigned int vblocks;
 257         unsigned char age = 0;
 258         unsigned char u;
 259         unsigned int i;
 260
 261         for (i = 0; i < sbi->segs_per_sec; i++)
 262                 mtime += get_seg_entry(sbi, start + i)->mtime;
 263         vblocks = get_valid_blocks(sbi, segno, true);
 264
 265         mtime = div_u64(mtime, sbi->segs_per_sec);
 266         vblocks = div_u64(vblocks, sbi->segs_per_sec);
 267
 268         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 269
 270         /* Handle if the system time has changed by the user */
 271         if (mtime < sit_i->min_mtime)
 272                 sit_i->min_mtime = mtime;
 273         if (mtime > sit_i->max_mtime)
 274                 sit_i->max_mtime = mtime;
 275         if (sit_i->max_mtime != sit_i->min_mtime)
 276                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 277                                 sit_i->max_mtime - sit_i->min_mtime);
 278
 279         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 280 }
 281
 282 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 283                         unsigned int segno, struct victim_sel_policy *p)
 284 {
 285         if (p->alloc_mode == SSR)
 286                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 287
 288         /* alloc_mode == LFS */
 289         if (p->gc_mode == GC_GREEDY)
 290                 return get_valid_blocks(sbi, segno, true);
 291         else
 292                 return get_cb_cost(sbi, segno);
 293 }
 294
 295 static unsigned int count_bits(const unsigned long *addr,
 296                                 unsigned int offset, unsigned int len)
 297 {
 298         unsigned int end = offset + len, sum = 0;
 299
 300         while (offset < end) {
 301                 if (test_bit(offset++, addr))
 302                         ++sum;
 303         }
 304         return sum;
 305 }
 306
 307 /*
 308  * This function is called from two paths.
 309  * One is garbage collection and the other is SSR segment selection.
 310  * When it is called during GC, it just gets a victim segment
 311  * and it does not remove it from dirty seglist.
 312  * When it is called from SSR segment selection, it finds a segment
 313  * which has minimum valid blocks and removes it from dirty seglist.
 314  */
 315 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 316                 unsigned int *result, int gc_type, int type, char alloc_mode)
 317 {
 318         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 319         struct sit_info *sm = SIT_I(sbi);
 320         struct victim_sel_policy p;
 321         unsigned int secno, last_victim;
 322         unsigned int last_segment;
 323         unsigned int nsearched = 0;
 324
 325         mutex_lock(&dirty_i->seglist_lock);
 326         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 327
 328         p.alloc_mode = alloc_mode;
 329         select_policy(sbi, gc_type, type, &p);
 330
 331         p.min_segno = NULL_SEGNO;
 332         p.min_cost = get_max_cost(sbi, &p);
 333
 334         if (*result != NULL_SEGNO) {
 335                 if (get_valid_blocks(sbi, *result, false) &&
 336                         !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 337                         p.min_segno = *result;
 338                 goto out;
 339         }
 340
 341         if (p.max_search == 0)
 342                 goto out;
 343
 344         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 345                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 346                         p.min_segno = sbi->next_victim_seg[BG_GC];
 347                         *result = p.min_segno;
 348                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 349                         goto got_result;
 350                 }
 351                 if (gc_type == FG_GC &&
 352                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 353                         p.min_segno = sbi->next_victim_seg[FG_GC];
 354                         *result = p.min_segno;
 355                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 356                         goto got_result;
 357                 }
 358         }
 359
 360         last_victim = sm->last_victim[p.gc_mode];
 361         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 362                 p.min_segno = check_bg_victims(sbi);
 363                 if (p.min_segno != NULL_SEGNO)
 364                         goto got_it;
 365         }
 366
 367         while (1) {
 368                 unsigned long cost;
 369                 unsigned int segno;
 370
 371                 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
 372                 if (segno >= last_segment) {
 373                         if (sm->last_victim[p.gc_mode]) {
 374                                 last_segment =
 375                                         sm->last_victim[p.gc_mode];
 376                                 sm->last_victim[p.gc_mode] = 0;
 377                                 p.offset = 0;
 378                                 continue;
 379                         }
 380                         break;
 381                 }
 382
 383                 p.offset = segno + p.ofs_unit;
 384                 if (p.ofs_unit > 1) {
 385                         p.offset -= segno % p.ofs_unit;
 386                         nsearched += count_bits(p.dirty_segmap,
 387                                                 p.offset - p.ofs_unit,
 388                                                 p.ofs_unit);
 389                 } else {
 390                         nsearched++;
 391                 }
 392
 393 #ifdef CONFIG_F2FS_CHECK_FS
 394                 /*
 395                  * skip selecting the invalid segno (that is failed due to block
 396                  * validity check failure during GC) to avoid endless GC loop in
 397                  * such cases.
 398                  */
 399                 if (test_bit(segno, sm->invalid_segmap))
 400                         goto next;
 401 #endif
 402
 403                 secno = GET_SEC_FROM_SEG(sbi, segno);
 404
 405                 if (sec_usage_check(sbi, secno))
 406                         goto next;
 407                 /* Don't touch checkpointed data */
 408                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
 409                                         get_ckpt_valid_blocks(sbi, segno) &&
 410                                         p.alloc_mode != SSR))
 411                         goto next;
 412                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 413                         goto next;
 414
 415                 cost = get_gc_cost(sbi, segno, &p);
 416
 417                 if (p.min_cost > cost) {
 418                         p.min_segno = segno;
 419                         p.min_cost = cost;
 420                 }
 421 next:
 422                 if (nsearched >= p.max_search) {
 423                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 424                                 sm->last_victim[p.gc_mode] = last_victim + 1;
 425                         else
 426                                 sm->last_victim[p.gc_mode] = segno + 1;
 427                         sm->last_victim[p.gc_mode] %=
 428                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 429                         break;
 430                 }
 431         }
 432         if (p.min_segno != NULL_SEGNO) {
 433 got_it:
 434                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 435 got_result:
 436                 if (p.alloc_mode == LFS) {
 437                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 438                         if (gc_type == FG_GC)
 439                                 sbi->cur_victim_sec = secno;
 440                         else
 441                                 set_bit(secno, dirty_i->victim_secmap);
 442                 }
 443
 444         }
 445 out:
 446         if (p.min_segno != NULL_SEGNO)
 447                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 448                                 sbi->cur_victim_sec,
 449                                 prefree_segments(sbi), free_segments(sbi));
 450         mutex_unlock(&dirty_i->seglist_lock);
 451
 452         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 453 }
 454
 455 static const struct victim_selection default_v_ops = {
 456         .get_victim = get_victim_by_default,
 457 };
 458
 459 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 460 {
 461         struct inode_entry *ie;
 462
 463         ie = radix_tree_lookup(&gc_list->iroot, ino);
 464         if (ie)
 465                 return ie->inode;
 466         return NULL;
 467 }
 468
 469 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 470 {
 471         struct inode_entry *new_ie;
 472
 473         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 474                 iput(inode);
 475                 return;
 476         }
 477         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 478         new_ie->inode = inode;
 479
 480         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 481         list_add_tail(&new_ie->list, &gc_list->ilist);
 482 }
 483
 484 static void put_gc_inode(struct gc_inode_list *gc_list)
 485 {
 486         struct inode_entry *ie, *next_ie;
 487         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 488                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 489                 iput(ie->inode);
 490                 list_del(&ie->list);
 491                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 492         }
 493 }
 494
 495 static int check_valid_map(struct f2fs_sb_info *sbi,
 496                                 unsigned int segno, int offset)
 497 {
 498         struct sit_info *sit_i = SIT_I(sbi);
 499         struct seg_entry *sentry;
 500         int ret;
 501
 502         down_read(&sit_i->sentry_lock);
 503         sentry = get_seg_entry(sbi, segno);
 504         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 505         up_read(&sit_i->sentry_lock);
 506         return ret;
 507 }
 508
 509 /*
 510  * This function compares node address got in summary with that in NAT.
 511  * On validity, copy that node with cold status, otherwise (invalid node)
 512  * ignore that.
 513  */
 514 static int gc_node_segment(struct f2fs_sb_info *sbi,
 515                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 516 {
 517         struct f2fs_summary *entry;
 518         block_t start_addr;
 519         int off;
 520         int phase = 0;
 521         bool fggc = (gc_type == FG_GC);
 522         int submitted = 0;
 523
 524         start_addr = START_BLOCK(sbi, segno);
 525
 526 next_step:
 527         entry = sum;
 528
 529         if (fggc && phase == 2)
 530                 atomic_inc(&sbi->wb_sync_req[NODE]);
 531
 532         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 533                 nid_t nid = le32_to_cpu(entry->nid);
 534                 struct page *node_page;
 535                 struct node_info ni;
 536                 int err;
 537
 538                 /* stop BG_GC if there is not enough free sections. */
 539                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 540                         return submitted;
 541
 542                 if (check_valid_map(sbi, segno, off) == 0)
 543                         continue;
 544
 545                 if (phase == 0) {
 546                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 547                                                         META_NAT, true);
 548                         continue;
 549                 }
 550
 551                 if (phase == 1) {
 552                         f2fs_ra_node_page(sbi, nid);
 553                         continue;
 554                 }
 555
 556                 /* phase == 2 */
 557                 node_page = f2fs_get_node_page(sbi, nid);
 558                 if (IS_ERR(node_page))
 559                         continue;
 560
 561                 /* block may become invalid during f2fs_get_node_page */
 562                 if (check_valid_map(sbi, segno, off) == 0) {
 563                         f2fs_put_page(node_page, 1);
 564                         continue;
 565                 }
 566
 567                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 568                         f2fs_put_page(node_page, 1);
 569                         continue;
 570                 }
 571
 572                 if (ni.blk_addr != start_addr + off) {
 573                         f2fs_put_page(node_page, 1);
 574                         continue;
 575                 }
 576
 577                 err = f2fs_move_node_page(node_page, gc_type);
 578                 if (!err && gc_type == FG_GC)
 579                         submitted++;
 580                 stat_inc_node_blk_count(sbi, 1, gc_type);
 581         }
 582
 583         if (++phase < 3)
 584                 goto next_step;
 585
 586         if (fggc)
 587                 atomic_dec(&sbi->wb_sync_req[NODE]);
 588         return submitted;
 589 }
 590
 591 /*
 592  * Calculate start block index indicating the given node offset.
 593  * Be careful, caller should give this node offset only indicating direct node
 594  * blocks. If any node offsets, which point the other types of node blocks such
 595  * as indirect or double indirect node blocks, are given, it must be a caller's
 596  * bug.
 597  */
 598 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 599 {
 600         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 601         unsigned int bidx;
 602
 603         if (node_ofs == 0)
 604                 return 0;
 605
 606         if (node_ofs <= 2) {
 607                 bidx = node_ofs - 1;
 608         } else if (node_ofs <= indirect_blks) {
 609                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 610                 bidx = node_ofs - 2 - dec;
 611         } else {
 612                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 613                 bidx = node_ofs - 5 - dec;
 614         }
 615         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
 616 }
 617
 618 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 619                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 620 {
 621         struct page *node_page;
 622         nid_t nid;
 623         unsigned int ofs_in_node;
 624         block_t source_blkaddr;
 625
 626         nid = le32_to_cpu(sum->nid);
 627         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 628
 629         node_page = f2fs_get_node_page(sbi, nid);
 630         if (IS_ERR(node_page))
 631                 return false;
 632
 633         if (f2fs_get_node_info(sbi, nid, dni)) {
 634                 f2fs_put_page(node_page, 1);
 635                 return false;
 636         }
 637
 638         if (sum->version != dni->version) {
 639                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
 640                           __func__);
 641                 set_sbi_flag(sbi, SBI_NEED_FSCK);
 642         }
 643
 644         *nofs = ofs_of_node(node_page);
 645         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
 646         f2fs_put_page(node_page, 1);
 647
 648         if (source_blkaddr != blkaddr) {
 649 #ifdef CONFIG_F2FS_CHECK_FS
 650                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
 651                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 652
 653                 if (unlikely(check_valid_map(sbi, segno, offset))) {
 654                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
 655                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n",
 656                                                 blkaddr, source_blkaddr, segno);
 657                                 f2fs_bug_on(sbi, 1);
 658                         }
 659                 }
 660 #endif
 661                 return false;
 662         }
 663         return true;
 664 }
 665
 666 static int ra_data_block(struct inode *inode, pgoff_t index)
 667 {
 668         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 669         struct address_space *mapping = inode->i_mapping;
 670         struct dnode_of_data dn;
 671         struct page *page;
 672         struct extent_info ei = {0, 0, 0};
 673         struct f2fs_io_info fio = {
 674                 .sbi = sbi,
 675                 .ino = inode->i_ino,
 676                 .type = DATA,
 677                 .temp = COLD,
 678                 .op = REQ_OP_READ,
 679                 .op_flags = 0,
 680                 .encrypted_page = NULL,
 681                 .in_list = false,
 682                 .retry = false,
 683         };
 684         int err;
 685
 686         page = f2fs_grab_cache_page(mapping, index, true);
 687         if (!page)
 688                 return -ENOMEM;
 689
 690         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 691                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 692                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 693                                                 DATA_GENERIC_ENHANCE_READ))) {
 694                         err = -EFSCORRUPTED;
 695                         goto put_page;
 696                 }
 697                 goto got_it;
 698         }
 699
 700         set_new_dnode(&dn, inode, NULL, NULL, 0);
 701         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
 702         if (err)
 703                 goto put_page;
 704         f2fs_put_dnode(&dn);
 705
 706         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
 707                 err = -ENOENT;
 708                 goto put_page;
 709         }
 710         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 711                                                 DATA_GENERIC_ENHANCE))) {
 712                 err = -EFSCORRUPTED;
 713                 goto put_page;
 714         }
 715 got_it:
 716         /* read page */
 717         fio.page = page;
 718         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 719
 720         /*
 721          * don't cache encrypted data into meta inode until previous dirty
 722          * data were writebacked to avoid racing between GC and flush.
 723          */
 724         f2fs_wait_on_page_writeback(page, DATA, true, true);
 725
 726         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
 727
 728         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
 729                                         dn.data_blkaddr,
 730                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
 731         if (!fio.encrypted_page) {
 732                 err = -ENOMEM;
 733                 goto put_page;
 734         }
 735
 736         err = f2fs_submit_page_bio(&fio);
 737         if (err)
 738                 goto put_encrypted_page;
 739         f2fs_put_page(fio.encrypted_page, 0);
 740         f2fs_put_page(page, 1);
 741
 742         f2fs_update_iostat(sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
 743         f2fs_update_iostat(sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
 744
 745         return 0;
 746 put_encrypted_page:
 747         f2fs_put_page(fio.encrypted_page, 1);
 748 put_page:
 749         f2fs_put_page(page, 1);
 750         return err;
 751 }
 752
 753 /*
 754  * Move data block via META_MAPPING while keeping locked data page.
 755  * This can be used to move blocks, aka LBAs, directly on disk.
 756  */
 757 static int move_data_block(struct inode *inode, block_t bidx,
 758                                 int gc_type, unsigned int segno, int off)
 759 {
 760         struct f2fs_io_info fio = {
 761                 .sbi = F2FS_I_SB(inode),
 762                 .ino = inode->i_ino,
 763                 .type = DATA,
 764                 .temp = COLD,
 765                 .op = REQ_OP_READ,
 766                 .op_flags = 0,
 767                 .encrypted_page = NULL,
 768                 .in_list = false,
 769                 .retry = false,
 770         };
 771         struct dnode_of_data dn;
 772         struct f2fs_summary sum;
 773         struct node_info ni;
 774         struct page *page, *mpage;
 775         block_t newaddr;
 776         int err = 0;
 777         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
 778
 779         /* do not read out */
 780         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
 781         if (!page)
 782                 return -ENOMEM;
 783
 784         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 785                 err = -ENOENT;
 786                 goto out;
 787         }
 788
 789         if (f2fs_is_atomic_file(inode)) {
 790                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 791                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 792                 err = -EAGAIN;
 793                 goto out;
 794         }
 795
 796         if (f2fs_is_pinned_file(inode)) {
 797                 f2fs_pin_file_control(inode, true);
 798                 err = -EAGAIN;
 799                 goto out;
 800         }
 801
 802         set_new_dnode(&dn, inode, NULL, NULL, 0);
 803         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 804         if (err)
 805                 goto out;
 806
 807         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 808                 ClearPageUptodate(page);
 809                 err = -ENOENT;
 810                 goto put_out;
 811         }
 812
 813         /*
 814          * don't cache encrypted data into meta inode until previous dirty
 815          * data were writebacked to avoid racing between GC and flush.
 816          */
 817         f2fs_wait_on_page_writeback(page, DATA, true, true);
 818
 819         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
 820
 821         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 822         if (err)
 823                 goto put_out;
 824
 825         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
 826
 827         /* read page */
 828         fio.page = page;
 829         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 830
 831         if (lfs_mode)
 832                 down_write(&fio.sbi->io_order_lock);
 833
 834         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
 835                                         fio.old_blkaddr, false);
 836         if (!mpage)
 837                 goto up_out;
 838
 839         fio.encrypted_page = mpage;
 840
 841         /* read source block in mpage */
 842         if (!PageUptodate(mpage)) {
 843                 err = f2fs_submit_page_bio(&fio);
 844                 if (err) {
 845                         f2fs_put_page(mpage, 1);
 846                         goto up_out;
 847                 }
 848
 849                 f2fs_update_iostat(fio.sbi, FS_DATA_READ_IO, F2FS_BLKSIZE);
 850                 f2fs_update_iostat(fio.sbi, FS_GDATA_READ_IO, F2FS_BLKSIZE);
 851
 852                 lock_page(mpage);
 853                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
 854                                                 !PageUptodate(mpage))) {
 855                         err = -EIO;
 856                         f2fs_put_page(mpage, 1);
 857                         goto up_out;
 858                 }
 859         }
 860
 861         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
 862                                         &sum, CURSEG_COLD_DATA, NULL, false);
 863
 864         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 865                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
 866         if (!fio.encrypted_page) {
 867                 err = -ENOMEM;
 868                 f2fs_put_page(mpage, 1);
 869                 goto recover_block;
 870         }
 871
 872         /* write target block */
 873         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
 874         memcpy(page_address(fio.encrypted_page),
 875                                 page_address(mpage), PAGE_SIZE);
 876         f2fs_put_page(mpage, 1);
 877         invalidate_mapping_pages(META_MAPPING(fio.sbi),
 878                                 fio.old_blkaddr, fio.old_blkaddr);
 879
 880         set_page_dirty(fio.encrypted_page);
 881         if (clear_page_dirty_for_io(fio.encrypted_page))
 882                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
 883
 884         set_page_writeback(fio.encrypted_page);
 885         ClearPageError(page);
 886
 887         /* allocate block address */
 888         f2fs_wait_on_page_writeback(dn.node_page, NODE, true, true);
 889
 890         fio.op = REQ_OP_WRITE;
 891         fio.op_flags = REQ_SYNC;
 892         fio.new_blkaddr = newaddr;
 893         f2fs_submit_page_write(&fio);
 894         if (fio.retry) {
 895                 err = -EAGAIN;
 896                 if (PageWriteback(fio.encrypted_page))
 897                         end_page_writeback(fio.encrypted_page);
 898                 goto put_page_out;
 899         }
 900
 901         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
 902
 903         f2fs_update_data_blkaddr(&dn, newaddr);
 904         set_inode_flag(inode, FI_APPEND_WRITE);
 905         if (page->index == 0)
 906                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 907 put_page_out:
 908         f2fs_put_page(fio.encrypted_page, 1);
 909 recover_block:
 910         if (err)
 911                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
 912                                                                 true, true);
 913 up_out:
 914         if (lfs_mode)
 915                 up_write(&fio.sbi->io_order_lock);
 916 put_out:
 917         f2fs_put_dnode(&dn);
 918 out:
 919         f2fs_put_page(page, 1);
 920         return err;
 921 }
 922
 923 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
 924                                                         unsigned int segno, int off)
 925 {
 926         struct page *page;
 927         int err = 0;
 928
 929         page = f2fs_get_lock_data_page(inode, bidx, true);
 930         if (IS_ERR(page))
 931                 return PTR_ERR(page);
 932
 933         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 934                 err = -ENOENT;
 935                 goto out;
 936         }
 937
 938         if (f2fs_is_atomic_file(inode)) {
 939                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 940                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 941                 err = -EAGAIN;
 942                 goto out;
 943         }
 944         if (f2fs_is_pinned_file(inode)) {
 945                 if (gc_type == FG_GC)
 946                         f2fs_pin_file_control(inode, true);
 947                 err = -EAGAIN;
 948                 goto out;
 949         }
 950
 951         if (gc_type == BG_GC) {
 952                 if (PageWriteback(page)) {
 953                         err = -EAGAIN;
 954                         goto out;
 955                 }
 956                 set_page_dirty(page);
 957                 set_cold_data(page);
 958         } else {
 959                 struct f2fs_io_info fio = {
 960                         .sbi = F2FS_I_SB(inode),
 961                         .ino = inode->i_ino,
 962                         .type = DATA,
 963                         .temp = COLD,
 964                         .op = REQ_OP_WRITE,
 965                         .op_flags = REQ_SYNC,
 966                         .old_blkaddr = NULL_ADDR,
 967                         .page = page,
 968                         .encrypted_page = NULL,
 969                         .need_lock = LOCK_REQ,
 970                         .io_type = FS_GC_DATA_IO,
 971                 };
 972                 bool is_dirty = PageDirty(page);
 973
 974 retry:
 975                 f2fs_wait_on_page_writeback(page, DATA, true, true);
 976
 977                 set_page_dirty(page);
 978                 if (clear_page_dirty_for_io(page)) {
 979                         inode_dec_dirty_pages(inode);
 980                         f2fs_remove_dirty_inode(inode);
 981                 }
 982
 983                 set_cold_data(page);
 984
 985                 err = f2fs_do_write_data_page(&fio);
 986                 if (err) {
 987                         clear_cold_data(page);
 988                         if (err == -ENOMEM) {
 989                                 congestion_wait(BLK_RW_ASYNC,
 990                                                 DEFAULT_IO_TIMEOUT);
 991                                 goto retry;
 992                         }
 993                         if (is_dirty)
 994                                 set_page_dirty(page);
 995                 }
 996         }
 997 out:
 998         f2fs_put_page(page, 1);
 999         return err;
1000 }
1001
1002 /*
1003  * This function tries to get parent node of victim data block, and identifies
1004  * data block validity. If the block is valid, copy that with cold status and
1005  * modify parent node.
1006  * If the parent node is not valid or the data block address is different,
1007  * the victim data block is ignored.
1008  */
1009 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1010                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
1011 {
1012         struct super_block *sb = sbi->sb;
1013         struct f2fs_summary *entry;
1014         block_t start_addr;
1015         int off;
1016         int phase = 0;
1017         int submitted = 0;
1018
1019         start_addr = START_BLOCK(sbi, segno);
1020
1021 next_step:
1022         entry = sum;
1023
1024         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
1025                 struct page *data_page;
1026                 struct inode *inode;
1027                 struct node_info dni; /* dnode info for the data */
1028                 unsigned int ofs_in_node, nofs;
1029                 block_t start_bidx;
1030                 nid_t nid = le32_to_cpu(entry->nid);
1031
1032                 /*
1033                  * stop BG_GC if there is not enough free sections.
1034                  * Or, stop GC if the segment becomes fully valid caused by
1035                  * race condition along with SSR block allocation.
1036                  */
1037                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1038                                 get_valid_blocks(sbi, segno, true) ==
1039                                                         BLKS_PER_SEC(sbi))
1040                         return submitted;
1041
1042                 if (check_valid_map(sbi, segno, off) == 0)
1043                         continue;
1044
1045                 if (phase == 0) {
1046                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1047                                                         META_NAT, true);
1048                         continue;
1049                 }
1050
1051                 if (phase == 1) {
1052                         f2fs_ra_node_page(sbi, nid);
1053                         continue;
1054                 }
1055
1056                 /* Get an inode by ino with checking validity */
1057                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1058                         continue;
1059
1060                 if (phase == 2) {
1061                         f2fs_ra_node_page(sbi, dni.ino);
1062                         continue;
1063                 }
1064
1065                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1066
1067                 if (phase == 3) {
1068                         inode = f2fs_iget(sb, dni.ino);
1069                         if (IS_ERR(inode) || is_bad_inode(inode)) {
1070                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1071                                 continue;
1072                         }
1073
1074                         if (!down_write_trylock(
1075                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1076                                 iput(inode);
1077                                 sbi->skipped_gc_rwsem++;
1078                                 continue;
1079                         }
1080
1081                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1082                                                                 ofs_in_node;
1083
1084                         if (f2fs_post_read_required(inode)) {
1085                                 int err = ra_data_block(inode, start_bidx);
1086
1087                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1088                                 if (err) {
1089                                         iput(inode);
1090                                         continue;
1091                                 }
1092                                 add_gc_inode(gc_list, inode);
1093                                 continue;
1094                         }
1095
1096                         data_page = f2fs_get_read_data_page(inode,
1097                                                 start_bidx, REQ_RAHEAD, true);
1098                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1099                         if (IS_ERR(data_page)) {
1100                                 iput(inode);
1101                                 continue;
1102                         }
1103
1104                         f2fs_put_page(data_page, 0);
1105                         add_gc_inode(gc_list, inode);
1106                         continue;
1107                 }
1108
1109                 /* phase 4 */
1110                 inode = find_gc_inode(gc_list, dni.ino);
1111                 if (inode) {
1112                         struct f2fs_inode_info *fi = F2FS_I(inode);
1113                         bool locked = false;
1114                         int err;
1115
1116                         if (S_ISREG(inode->i_mode)) {
1117                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1118                                         continue;
1119                                 if (!down_write_trylock(
1120                                                 &fi->i_gc_rwsem[WRITE])) {
1121                                         sbi->skipped_gc_rwsem++;
1122                                         up_write(&fi->i_gc_rwsem[READ]);
1123                                         continue;
1124                                 }
1125                                 locked = true;
1126
1127                                 /* wait for all inflight aio data */
1128                                 inode_dio_wait(inode);
1129                         }
1130
1131                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1132                                                                 + ofs_in_node;
1133                         if (f2fs_post_read_required(inode))
1134                                 err = move_data_block(inode, start_bidx,
1135                                                         gc_type, segno, off);
1136                         else
1137                                 err = move_data_page(inode, start_bidx, gc_type,
1138                                                                 segno, off);
1139
1140                         if (!err && (gc_type == FG_GC ||
1141                                         f2fs_post_read_required(inode)))
1142                                 submitted++;
1143
1144                         if (locked) {
1145                                 up_write(&fi->i_gc_rwsem[WRITE]);
1146                                 up_write(&fi->i_gc_rwsem[READ]);
1147                         }
1148
1149                         stat_inc_data_blk_count(sbi, 1, gc_type);
1150                 }
1151         }
1152
1153         if (++phase < 5)
1154                 goto next_step;
1155
1156         return submitted;
1157 }
1158
1159 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1160                         int gc_type)
1161 {
1162         struct sit_info *sit_i = SIT_I(sbi);
1163         int ret;
1164
1165         down_write(&sit_i->sentry_lock);
1166         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1167                                               NO_CHECK_TYPE, LFS);
1168         up_write(&sit_i->sentry_lock);
1169         return ret;
1170 }
1171
1172 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1173                                 unsigned int start_segno,
1174                                 struct gc_inode_list *gc_list, int gc_type)
1175 {
1176         struct page *sum_page;
1177         struct f2fs_summary_block *sum;
1178         struct blk_plug plug;
1179         unsigned int segno = start_segno;
1180         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1181         int seg_freed = 0, migrated = 0;
1182         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1183                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1184         int submitted = 0;
1185
1186         if (__is_large_section(sbi))
1187                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1188
1189         /* readahead multi ssa blocks those have contiguous address */
1190         if (__is_large_section(sbi))
1191                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1192                                         end_segno - segno, META_SSA, true);
1193
1194         /* reference all summary page */
1195         while (segno < end_segno) {
1196                 sum_page = f2fs_get_sum_page(sbi, segno++);
1197                 if (IS_ERR(sum_page)) {
1198                         int err = PTR_ERR(sum_page);
1199
1200                         end_segno = segno - 1;
1201                         for (segno = start_segno; segno < end_segno; segno++) {
1202                                 sum_page = find_get_page(META_MAPPING(sbi),
1203                                                 GET_SUM_BLOCK(sbi, segno));
1204                                 f2fs_put_page(sum_page, 0);
1205                                 f2fs_put_page(sum_page, 0);
1206                         }
1207                         return err;
1208                 }
1209                 unlock_page(sum_page);
1210         }
1211
1212         blk_start_plug(&plug);
1213
1214         for (segno = start_segno; segno < end_segno; segno++) {
1215
1216                 /* find segment summary of victim */
1217                 sum_page = find_get_page(META_MAPPING(sbi),
1218                                         GET_SUM_BLOCK(sbi, segno));
1219                 f2fs_put_page(sum_page, 0);
1220
1221                 if (get_valid_blocks(sbi, segno, false) == 0)
1222                         goto freed;
1223                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1224                                 migrated >= sbi->migration_granularity)
1225                         goto skip;
1226                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1227                         goto skip;
1228
1229                 sum = page_address(sum_page);
1230                 if (type != GET_SUM_TYPE((&sum->footer))) {
1231                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1232                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1233                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1234                         f2fs_stop_checkpoint(sbi, false);
1235                         goto skip;
1236                 }
1237
1238                 /*
1239                  * this is to avoid deadlock:
1240                  * - lock_page(sum_page)         - f2fs_replace_block
1241                  *  - check_valid_map()            - down_write(sentry_lock)
1242                  *   - down_read(sentry_lock)     - change_curseg()
1243                  *                                  - lock_page(sum_page)
1244                  */
1245                 if (type == SUM_TYPE_NODE)
1246                         submitted += gc_node_segment(sbi, sum->entries, segno,
1247                                                                 gc_type);
1248                 else
1249                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1250                                                         segno, gc_type);
1251
1252                 stat_inc_seg_count(sbi, type, gc_type);
1253                 migrated++;
1254
1255 freed:
1256                 if (gc_type == FG_GC &&
1257                                 get_valid_blocks(sbi, segno, false) == 0)
1258                         seg_freed++;
1259
1260                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1261                         sbi->next_victim_seg[gc_type] = segno + 1;
1262 skip:
1263                 f2fs_put_page(sum_page, 0);
1264         }
1265
1266         if (submitted)
1267                 f2fs_submit_merged_write(sbi,
1268                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1269
1270         blk_finish_plug(&plug);
1271
1272         stat_inc_call_count(sbi->stat_info);
1273
1274         return seg_freed;
1275 }
1276
1277 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1278                         bool background, unsigned int segno)
1279 {
1280         int gc_type = sync ? FG_GC : BG_GC;
1281         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1282         int ret = 0;
1283         struct cp_control cpc;
1284         unsigned int init_segno = segno;
1285         struct gc_inode_list gc_list = {
1286                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1287                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1288         };
1289         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1290         unsigned long long first_skipped;
1291         unsigned int skipped_round = 0, round = 0;
1292
1293         trace_f2fs_gc_begin(sbi->sb, sync, background,
1294                                 get_pages(sbi, F2FS_DIRTY_NODES),
1295                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1296                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1297                                 free_sections(sbi),
1298                                 free_segments(sbi),
1299                                 reserved_segments(sbi),
1300                                 prefree_segments(sbi));
1301
1302         cpc.reason = __get_cp_reason(sbi);
1303         sbi->skipped_gc_rwsem = 0;
1304         first_skipped = last_skipped;
1305 gc_more:
1306         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1307                 ret = -EINVAL;
1308                 goto stop;
1309         }
1310         if (unlikely(f2fs_cp_error(sbi))) {
1311                 ret = -EIO;
1312                 goto stop;
1313         }
1314
1315         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1316                 /*
1317                  * For example, if there are many prefree_segments below given
1318                  * threshold, we can make them free by checkpoint. Then, we
1319                  * secure free segments which doesn't need fggc any more.
1320                  */
1321                 if (prefree_segments(sbi) &&
1322                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1323                         ret = f2fs_write_checkpoint(sbi, &cpc);
1324                         if (ret)
1325                                 goto stop;
1326                 }
1327                 if (has_not_enough_free_secs(sbi, 0, 0))
1328                         gc_type = FG_GC;
1329         }
1330
1331         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1332         if (gc_type == BG_GC && !background) {
1333                 ret = -EINVAL;
1334                 goto stop;
1335         }
1336         if (!__get_victim(sbi, &segno, gc_type)) {
1337                 ret = -ENODATA;
1338                 goto stop;
1339         }
1340
1341         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1342         if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1343                 sec_freed++;
1344         total_freed += seg_freed;
1345
1346         if (gc_type == FG_GC) {
1347                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1348                                                 sbi->skipped_gc_rwsem)
1349                         skipped_round++;
1350                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1351                 round++;
1352         }
1353
1354         if (gc_type == FG_GC && seg_freed)
1355                 sbi->cur_victim_sec = NULL_SEGNO;
1356
1357         if (sync)
1358                 goto stop;
1359
1360         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1361                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1362                                         skipped_round * 2 < round) {
1363                         segno = NULL_SEGNO;
1364                         goto gc_more;
1365                 }
1366
1367                 if (first_skipped < last_skipped &&
1368                                 (last_skipped - first_skipped) >
1369                                                 sbi->skipped_gc_rwsem) {
1370                         f2fs_drop_inmem_pages_all(sbi, true);
1371                         segno = NULL_SEGNO;
1372                         goto gc_more;
1373                 }
1374                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1375                         ret = f2fs_write_checkpoint(sbi, &cpc);
1376         }
1377 stop:
1378         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1379         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1380
1381         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1382                                 get_pages(sbi, F2FS_DIRTY_NODES),
1383                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1384                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1385                                 free_sections(sbi),
1386                                 free_segments(sbi),
1387                                 reserved_segments(sbi),
1388                                 prefree_segments(sbi));
1389
1390         up_write(&sbi->gc_lock);
1391
1392         put_gc_inode(&gc_list);
1393
1394         if (sync && !ret)
1395                 ret = sec_freed ? 0 : -EAGAIN;
1396         return ret;
1397 }
1398
1399 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1400 {
1401         DIRTY_I(sbi)->v_ops = &default_v_ops;
1402
1403         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1404
1405         /* give warm/cold data area from slower device */
1406         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1407                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1408                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1409 }
1410
1411 static int free_segment_range(struct f2fs_sb_info *sbi,
1412                                 unsigned int secs, bool gc_only)
1413 {
1414         unsigned int segno, next_inuse, start, end;
1415         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1416         int gc_mode, gc_type;
1417         int err = 0;
1418         int type;
1419
1420         /* Force block allocation for GC */
1421         MAIN_SECS(sbi) -= secs;
1422         start = MAIN_SECS(sbi) * sbi->segs_per_sec;
1423         end = MAIN_SEGS(sbi) - 1;
1424
1425         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1426         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1427                 if (SIT_I(sbi)->last_victim[gc_mode] >= start)
1428                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1429
1430         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1431                 if (sbi->next_victim_seg[gc_type] >= start)
1432                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1433         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1434
1435         /* Move out cursegs from the target range */
1436         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++)
1437                 allocate_segment_for_resize(sbi, type, start, end);
1438
1439         /* do GC to move out valid blocks in the range */
1440         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1441                 struct gc_inode_list gc_list = {
1442                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1443                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1444                 };
1445
1446                 do_garbage_collect(sbi, segno, &gc_list, FG_GC);
1447                 put_gc_inode(&gc_list);
1448
1449                 if (!gc_only && get_valid_blocks(sbi, segno, true)) {
1450                         err = -EAGAIN;
1451                         goto out;
1452                 }
1453                 if (fatal_signal_pending(current)) {
1454                         err = -ERESTARTSYS;
1455                         goto out;
1456                 }
1457         }
1458         if (gc_only)
1459                 goto out;
1460
1461         err = f2fs_write_checkpoint(sbi, &cpc);
1462         if (err)
1463                 goto out;
1464
1465         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1466         if (next_inuse <= end) {
1467                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1468                          next_inuse);
1469                 f2fs_bug_on(sbi, 1);
1470         }
1471 out:
1472         MAIN_SECS(sbi) += secs;
1473         return err;
1474 }
1475
1476 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1477 {
1478         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1479         int section_count;
1480         int segment_count;
1481         int segment_count_main;
1482         long long block_count;
1483         int segs = secs * sbi->segs_per_sec;
1484
1485         down_write(&sbi->sb_lock);
1486
1487         section_count = le32_to_cpu(raw_sb->section_count);
1488         segment_count = le32_to_cpu(raw_sb->segment_count);
1489         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1490         block_count = le64_to_cpu(raw_sb->block_count);
1491
1492         raw_sb->section_count = cpu_to_le32(section_count + secs);
1493         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1494         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1495         raw_sb->block_count = cpu_to_le64(block_count +
1496                                         (long long)segs * sbi->blocks_per_seg);
1497         if (f2fs_is_multi_device(sbi)) {
1498                 int last_dev = sbi->s_ndevs - 1;
1499                 int dev_segs =
1500                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1501
1502                 raw_sb->devs[last_dev].total_segments =
1503                                                 cpu_to_le32(dev_segs + segs);
1504         }
1505
1506         up_write(&sbi->sb_lock);
1507 }
1508
1509 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1510 {
1511         int segs = secs * sbi->segs_per_sec;
1512         long long blks = (long long)segs * sbi->blocks_per_seg;
1513         long long user_block_count =
1514                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1515
1516         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1517         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1518         MAIN_SECS(sbi) += secs;
1519         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1520         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1521         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1522
1523         if (f2fs_is_multi_device(sbi)) {
1524                 int last_dev = sbi->s_ndevs - 1;
1525
1526                 FDEV(last_dev).total_segments =
1527                                 (int)FDEV(last_dev).total_segments + segs;
1528                 FDEV(last_dev).end_blk =
1529                                 (long long)FDEV(last_dev).end_blk + blks;
1530 #ifdef CONFIG_BLK_DEV_ZONED
1531                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1532                                         (int)(blks >> sbi->log_blocks_per_blkz);
1533 #endif
1534         }
1535 }
1536
1537 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1538 {
1539         __u64 old_block_count, shrunk_blocks;
1540         struct cp_control cpc = { CP_RESIZE, 0, 0, 0 };
1541         unsigned int secs;
1542         int err = 0;
1543         __u32 rem;
1544
1545         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1546         if (block_count > old_block_count)
1547                 return -EINVAL;
1548
1549         if (f2fs_is_multi_device(sbi)) {
1550                 int last_dev = sbi->s_ndevs - 1;
1551                 __u64 last_segs = FDEV(last_dev).total_segments;
1552
1553                 if (block_count + last_segs * sbi->blocks_per_seg <=
1554                                                                 old_block_count)
1555                         return -EINVAL;
1556         }
1557
1558         /* new fs size should align to section size */
1559         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
1560         if (rem)
1561                 return -EINVAL;
1562
1563         if (block_count == old_block_count)
1564                 return 0;
1565
1566         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1567                 f2fs_err(sbi, "Should run fsck to repair first.");
1568                 return -EFSCORRUPTED;
1569         }
1570
1571         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
1572                 f2fs_err(sbi, "Checkpoint should be enabled.");
1573                 return -EINVAL;
1574         }
1575
1576         shrunk_blocks = old_block_count - block_count;
1577         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
1578
1579         /* stop other GC */
1580         if (!down_write_trylock(&sbi->gc_lock))
1581                 return -EAGAIN;
1582
1583         /* stop CP to protect MAIN_SEC in free_segment_range */
1584         f2fs_lock_op(sbi);
1585         err = free_segment_range(sbi, secs, true);
1586         f2fs_unlock_op(sbi);
1587         up_write(&sbi->gc_lock);
1588         if (err)
1589                 return err;
1590
1591         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
1592
1593         freeze_super(sbi->sb);
1594         down_write(&sbi->gc_lock);
1595         mutex_lock(&sbi->cp_mutex);
1596
1597         spin_lock(&sbi->stat_lock);
1598         if (shrunk_blocks + valid_user_blocks(sbi) +
1599                 sbi->current_reserved_blocks + sbi->unusable_block_count +
1600                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
1601                 err = -ENOSPC;
1602         else
1603                 sbi->user_block_count -= shrunk_blocks;
1604         spin_unlock(&sbi->stat_lock);
1605         if (err)
1606                 goto out_err;
1607
1608         err = free_segment_range(sbi, secs, false);
1609         if (err)
1610                 goto recover_out;
1611
1612         update_sb_metadata(sbi, -secs);
1613
1614         err = f2fs_commit_super(sbi, false);
1615         if (err) {
1616                 update_sb_metadata(sbi, secs);
1617                 goto recover_out;
1618         }
1619
1620         update_fs_metadata(sbi, -secs);
1621         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
1622         set_sbi_flag(sbi, SBI_IS_DIRTY);
1623
1624         err = f2fs_write_checkpoint(sbi, &cpc);
1625         if (err) {
1626                 update_fs_metadata(sbi, secs);
1627                 update_sb_metadata(sbi, secs);
1628                 f2fs_commit_super(sbi, false);
1629         }
1630 recover_out:
1631         if (err) {
1632                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1633                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
1634
1635                 spin_lock(&sbi->stat_lock);
1636                 sbi->user_block_count += shrunk_blocks;
1637                 spin_unlock(&sbi->stat_lock);
1638         }
1639 out_err:
1640         mutex_unlock(&sbi->cp_mutex);
1641         up_write(&sbi->gc_lock);
1642         thaw_super(sbi->sb);
1643         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
1644         return err;
1645 }