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
  17 #include "f2fs.h"
  18 #include "node.h"
  19 #include "segment.h"
  20 #include "gc.h"
  21 #include <trace/events/f2fs.h>
  22
  23 static int gc_thread_func(void *data)
  24 {
  25         struct f2fs_sb_info *sbi = data;
  26         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  27         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  28         unsigned int wait_ms;
  29
  30         wait_ms = gc_th->min_sleep_time;
  31
  32         set_freezable();
  33         do {
  34                 wait_event_interruptible_timeout(*wq,
  35                                 kthread_should_stop() || freezing(current) ||
  36                                 gc_th->gc_wake,
  37                                 msecs_to_jiffies(wait_ms));
  38
  39                 /* give it a try one time */
  40                 if (gc_th->gc_wake)
  41                         gc_th->gc_wake = 0;
  42
  43                 if (try_to_freeze()) {
  44                         stat_other_skip_bggc_count(sbi);
  45                         continue;
  46                 }
  47                 if (kthread_should_stop())
  48                         break;
  49
  50                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  51                         increase_sleep_time(gc_th, &wait_ms);
  52                         stat_other_skip_bggc_count(sbi);
  53                         continue;
  54                 }
  55
  56                 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  57                         f2fs_show_injection_info(FAULT_CHECKPOINT);
  58                         f2fs_stop_checkpoint(sbi, false);
  59                 }
  60
  61                 if (!sb_start_write_trylock(sbi->sb)) {
  62                         stat_other_skip_bggc_count(sbi);
  63                         continue;
  64                 }
  65
  66                 /*
  67                  * [GC triggering condition]
  68                  * 0. GC is not conducted currently.
  69                  * 1. There are enough dirty segments.
  70                  * 2. IO subsystem is idle by checking the # of writeback pages.
  71                  * 3. IO subsystem is idle by checking the # of requests in
  72                  *    bdev's request list.
  73                  *
  74                  * Note) We have to avoid triggering GCs frequently.
  75                  * Because it is possible that some segments can be
  76                  * invalidated soon after by user update or deletion.
  77                  * So, I'd like to wait some time to collect dirty segments.
  78                  */
  79                 if (sbi->gc_mode == GC_URGENT) {
  80                         wait_ms = gc_th->urgent_sleep_time;
  81                         mutex_lock(&sbi->gc_mutex);
  82                         goto do_gc;
  83                 }
  84
  85                 if (!mutex_trylock(&sbi->gc_mutex)) {
  86                         stat_other_skip_bggc_count(sbi);
  87                         goto next;
  88                 }
  89
  90                 if (!is_idle(sbi, GC_TIME)) {
  91                         increase_sleep_time(gc_th, &wait_ms);
  92                         mutex_unlock(&sbi->gc_mutex);
  93                         stat_io_skip_bggc_count(sbi);
  94                         goto next;
  95                 }
  96
  97                 if (has_enough_invalid_blocks(sbi))
  98                         decrease_sleep_time(gc_th, &wait_ms);
  99                 else
 100                         increase_sleep_time(gc_th, &wait_ms);
 101 do_gc:
 102                 stat_inc_bggc_count(sbi);
 103
 104                 /* if return value is not zero, no victim was selected */
 105                 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
 106                         wait_ms = gc_th->no_gc_sleep_time;
 107
 108                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 109                                 prefree_segments(sbi), free_segments(sbi));
 110
 111                 /* balancing f2fs's metadata periodically */
 112                 f2fs_balance_fs_bg(sbi);
 113 next:
 114                 sb_end_write(sbi->sb);
 115
 116         } while (!kthread_should_stop());
 117         return 0;
 118 }
 119
 120 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 121 {
 122         struct f2fs_gc_kthread *gc_th;
 123         dev_t dev = sbi->sb->s_bdev->bd_dev;
 124         int err = 0;
 125
 126         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 127         if (!gc_th) {
 128                 err = -ENOMEM;
 129                 goto out;
 130         }
 131
 132         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 133         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 134         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 135         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 136
 137         gc_th->gc_wake= 0;
 138
 139         sbi->gc_thread = gc_th;
 140         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 141         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 142                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 143         if (IS_ERR(gc_th->f2fs_gc_task)) {
 144                 err = PTR_ERR(gc_th->f2fs_gc_task);
 145                 kfree(gc_th);
 146                 sbi->gc_thread = NULL;
 147         }
 148 out:
 149         return err;
 150 }
 151
 152 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 153 {
 154         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 155         if (!gc_th)
 156                 return;
 157         kthread_stop(gc_th->f2fs_gc_task);
 158         kfree(gc_th);
 159         sbi->gc_thread = NULL;
 160 }
 161
 162 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 163 {
 164         int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
 165
 166         switch (sbi->gc_mode) {
 167         case GC_IDLE_CB:
 168                 gc_mode = GC_CB;
 169                 break;
 170         case GC_IDLE_GREEDY:
 171         case GC_URGENT:
 172                 gc_mode = GC_GREEDY;
 173                 break;
 174         }
 175         return gc_mode;
 176 }
 177
 178 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 179                         int type, struct victim_sel_policy *p)
 180 {
 181         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 182
 183         if (p->alloc_mode == SSR) {
 184                 p->gc_mode = GC_GREEDY;
 185                 p->dirty_segmap = dirty_i->dirty_segmap[type];
 186                 p->max_search = dirty_i->nr_dirty[type];
 187                 p->ofs_unit = 1;
 188         } else {
 189                 p->gc_mode = select_gc_type(sbi, gc_type);
 190                 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
 191                 p->max_search = dirty_i->nr_dirty[DIRTY];
 192                 p->ofs_unit = sbi->segs_per_sec;
 193         }
 194
 195         /* we need to check every dirty segments in the FG_GC case */
 196         if (gc_type != FG_GC &&
 197                         (sbi->gc_mode != GC_URGENT) &&
 198                         p->max_search > sbi->max_victim_search)
 199                 p->max_search = sbi->max_victim_search;
 200
 201         /* let's select beginning hot/small space first in no_heap mode*/
 202         if (test_opt(sbi, NOHEAP) &&
 203                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 204                 p->offset = 0;
 205         else
 206                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 207 }
 208
 209 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 210                                 struct victim_sel_policy *p)
 211 {
 212         /* SSR allocates in a segment unit */
 213         if (p->alloc_mode == SSR)
 214                 return sbi->blocks_per_seg;
 215         if (p->gc_mode == GC_GREEDY)
 216                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 217         else if (p->gc_mode == GC_CB)
 218                 return UINT_MAX;
 219         else /* No other gc_mode */
 220                 return 0;
 221 }
 222
 223 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 224 {
 225         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 226         unsigned int secno;
 227
 228         /*
 229          * If the gc_type is FG_GC, we can select victim segments
 230          * selected by background GC before.
 231          * Those segments guarantee they have small valid blocks.
 232          */
 233         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 234                 if (sec_usage_check(sbi, secno))
 235                         continue;
 236                 clear_bit(secno, dirty_i->victim_secmap);
 237                 return GET_SEG_FROM_SEC(sbi, secno);
 238         }
 239         return NULL_SEGNO;
 240 }
 241
 242 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 243 {
 244         struct sit_info *sit_i = SIT_I(sbi);
 245         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 246         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 247         unsigned long long mtime = 0;
 248         unsigned int vblocks;
 249         unsigned char age = 0;
 250         unsigned char u;
 251         unsigned int i;
 252
 253         for (i = 0; i < sbi->segs_per_sec; i++)
 254                 mtime += get_seg_entry(sbi, start + i)->mtime;
 255         vblocks = get_valid_blocks(sbi, segno, true);
 256
 257         mtime = div_u64(mtime, sbi->segs_per_sec);
 258         vblocks = div_u64(vblocks, sbi->segs_per_sec);
 259
 260         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 261
 262         /* Handle if the system time has changed by the user */
 263         if (mtime < sit_i->min_mtime)
 264                 sit_i->min_mtime = mtime;
 265         if (mtime > sit_i->max_mtime)
 266                 sit_i->max_mtime = mtime;
 267         if (sit_i->max_mtime != sit_i->min_mtime)
 268                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 269                                 sit_i->max_mtime - sit_i->min_mtime);
 270
 271         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 272 }
 273
 274 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 275                         unsigned int segno, struct victim_sel_policy *p)
 276 {
 277         if (p->alloc_mode == SSR)
 278                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 279
 280         /* alloc_mode == LFS */
 281         if (p->gc_mode == GC_GREEDY)
 282                 return get_valid_blocks(sbi, segno, true);
 283         else
 284                 return get_cb_cost(sbi, segno);
 285 }
 286
 287 static unsigned int count_bits(const unsigned long *addr,
 288                                 unsigned int offset, unsigned int len)
 289 {
 290         unsigned int end = offset + len, sum = 0;
 291
 292         while (offset < end) {
 293                 if (test_bit(offset++, addr))
 294                         ++sum;
 295         }
 296         return sum;
 297 }
 298
 299 /*
 300  * This function is called from two paths.
 301  * One is garbage collection and the other is SSR segment selection.
 302  * When it is called during GC, it just gets a victim segment
 303  * and it does not remove it from dirty seglist.
 304  * When it is called from SSR segment selection, it finds a segment
 305  * which has minimum valid blocks and removes it from dirty seglist.
 306  */
 307 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 308                 unsigned int *result, int gc_type, int type, char alloc_mode)
 309 {
 310         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 311         struct sit_info *sm = SIT_I(sbi);
 312         struct victim_sel_policy p;
 313         unsigned int secno, last_victim;
 314         unsigned int last_segment = MAIN_SEGS(sbi);
 315         unsigned int nsearched = 0;
 316
 317         mutex_lock(&dirty_i->seglist_lock);
 318
 319         p.alloc_mode = alloc_mode;
 320         select_policy(sbi, gc_type, type, &p);
 321
 322         p.min_segno = NULL_SEGNO;
 323         p.min_cost = get_max_cost(sbi, &p);
 324
 325         if (*result != NULL_SEGNO) {
 326                 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) &&
 327                         get_valid_blocks(sbi, *result, false) &&
 328                         !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 329                         p.min_segno = *result;
 330                 goto out;
 331         }
 332
 333         if (p.max_search == 0)
 334                 goto out;
 335
 336         last_victim = sm->last_victim[p.gc_mode];
 337         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 338                 p.min_segno = check_bg_victims(sbi);
 339                 if (p.min_segno != NULL_SEGNO)
 340                         goto got_it;
 341         }
 342
 343         while (1) {
 344                 unsigned long cost;
 345                 unsigned int segno;
 346
 347                 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
 348                 if (segno >= last_segment) {
 349                         if (sm->last_victim[p.gc_mode]) {
 350                                 last_segment =
 351                                         sm->last_victim[p.gc_mode];
 352                                 sm->last_victim[p.gc_mode] = 0;
 353                                 p.offset = 0;
 354                                 continue;
 355                         }
 356                         break;
 357                 }
 358
 359                 p.offset = segno + p.ofs_unit;
 360                 if (p.ofs_unit > 1) {
 361                         p.offset -= segno % p.ofs_unit;
 362                         nsearched += count_bits(p.dirty_segmap,
 363                                                 p.offset - p.ofs_unit,
 364                                                 p.ofs_unit);
 365                 } else {
 366                         nsearched++;
 367                 }
 368
 369                 secno = GET_SEC_FROM_SEG(sbi, segno);
 370
 371                 if (sec_usage_check(sbi, secno))
 372                         goto next;
 373                 /* Don't touch checkpointed data */
 374                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
 375                                         get_ckpt_valid_blocks(sbi, segno)))
 376                         goto next;
 377                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 378                         goto next;
 379
 380                 cost = get_gc_cost(sbi, segno, &p);
 381
 382                 if (p.min_cost > cost) {
 383                         p.min_segno = segno;
 384                         p.min_cost = cost;
 385                 }
 386 next:
 387                 if (nsearched >= p.max_search) {
 388                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 389                                 sm->last_victim[p.gc_mode] = last_victim + 1;
 390                         else
 391                                 sm->last_victim[p.gc_mode] = segno + 1;
 392                         sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
 393                         break;
 394                 }
 395         }
 396         if (p.min_segno != NULL_SEGNO) {
 397 got_it:
 398                 if (p.alloc_mode == LFS) {
 399                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 400                         if (gc_type == FG_GC)
 401                                 sbi->cur_victim_sec = secno;
 402                         else
 403                                 set_bit(secno, dirty_i->victim_secmap);
 404                 }
 405                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 406
 407                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 408                                 sbi->cur_victim_sec,
 409                                 prefree_segments(sbi), free_segments(sbi));
 410         }
 411 out:
 412         mutex_unlock(&dirty_i->seglist_lock);
 413
 414         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 415 }
 416
 417 static const struct victim_selection default_v_ops = {
 418         .get_victim = get_victim_by_default,
 419 };
 420
 421 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 422 {
 423         struct inode_entry *ie;
 424
 425         ie = radix_tree_lookup(&gc_list->iroot, ino);
 426         if (ie)
 427                 return ie->inode;
 428         return NULL;
 429 }
 430
 431 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 432 {
 433         struct inode_entry *new_ie;
 434
 435         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 436                 iput(inode);
 437                 return;
 438         }
 439         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 440         new_ie->inode = inode;
 441
 442         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 443         list_add_tail(&new_ie->list, &gc_list->ilist);
 444 }
 445
 446 static void put_gc_inode(struct gc_inode_list *gc_list)
 447 {
 448         struct inode_entry *ie, *next_ie;
 449         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 450                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 451                 iput(ie->inode);
 452                 list_del(&ie->list);
 453                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 454         }
 455 }
 456
 457 static int check_valid_map(struct f2fs_sb_info *sbi,
 458                                 unsigned int segno, int offset)
 459 {
 460         struct sit_info *sit_i = SIT_I(sbi);
 461         struct seg_entry *sentry;
 462         int ret;
 463
 464         down_read(&sit_i->sentry_lock);
 465         sentry = get_seg_entry(sbi, segno);
 466         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 467         up_read(&sit_i->sentry_lock);
 468         return ret;
 469 }
 470
 471 /*
 472  * This function compares node address got in summary with that in NAT.
 473  * On validity, copy that node with cold status, otherwise (invalid node)
 474  * ignore that.
 475  */
 476 static int gc_node_segment(struct f2fs_sb_info *sbi,
 477                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 478 {
 479         struct f2fs_summary *entry;
 480         block_t start_addr;
 481         int off;
 482         int phase = 0;
 483         bool fggc = (gc_type == FG_GC);
 484         int submitted = 0;
 485
 486         start_addr = START_BLOCK(sbi, segno);
 487
 488 next_step:
 489         entry = sum;
 490
 491         if (fggc && phase == 2)
 492                 atomic_inc(&sbi->wb_sync_req[NODE]);
 493
 494         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 495                 nid_t nid = le32_to_cpu(entry->nid);
 496                 struct page *node_page;
 497                 struct node_info ni;
 498                 int err;
 499
 500                 /* stop BG_GC if there is not enough free sections. */
 501                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 502                         return submitted;
 503
 504                 if (check_valid_map(sbi, segno, off) == 0)
 505                         continue;
 506
 507                 if (phase == 0) {
 508                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 509                                                         META_NAT, true);
 510                         continue;
 511                 }
 512
 513                 if (phase == 1) {
 514                         f2fs_ra_node_page(sbi, nid);
 515                         continue;
 516                 }
 517
 518                 /* phase == 2 */
 519                 node_page = f2fs_get_node_page(sbi, nid);
 520                 if (IS_ERR(node_page))
 521                         continue;
 522
 523                 /* block may become invalid during f2fs_get_node_page */
 524                 if (check_valid_map(sbi, segno, off) == 0) {
 525                         f2fs_put_page(node_page, 1);
 526                         continue;
 527                 }
 528
 529                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 530                         f2fs_put_page(node_page, 1);
 531                         continue;
 532                 }
 533
 534                 if (ni.blk_addr != start_addr + off) {
 535                         f2fs_put_page(node_page, 1);
 536                         continue;
 537                 }
 538
 539                 err = f2fs_move_node_page(node_page, gc_type);
 540                 if (!err && gc_type == FG_GC)
 541                         submitted++;
 542                 stat_inc_node_blk_count(sbi, 1, gc_type);
 543         }
 544
 545         if (++phase < 3)
 546                 goto next_step;
 547
 548         if (fggc)
 549                 atomic_dec(&sbi->wb_sync_req[NODE]);
 550         return submitted;
 551 }
 552
 553 /*
 554  * Calculate start block index indicating the given node offset.
 555  * Be careful, caller should give this node offset only indicating direct node
 556  * blocks. If any node offsets, which point the other types of node blocks such
 557  * as indirect or double indirect node blocks, are given, it must be a caller's
 558  * bug.
 559  */
 560 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 561 {
 562         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 563         unsigned int bidx;
 564
 565         if (node_ofs == 0)
 566                 return 0;
 567
 568         if (node_ofs <= 2) {
 569                 bidx = node_ofs - 1;
 570         } else if (node_ofs <= indirect_blks) {
 571                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 572                 bidx = node_ofs - 2 - dec;
 573         } else {
 574                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 575                 bidx = node_ofs - 5 - dec;
 576         }
 577         return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
 578 }
 579
 580 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 581                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 582 {
 583         struct page *node_page;
 584         nid_t nid;
 585         unsigned int ofs_in_node;
 586         block_t source_blkaddr;
 587
 588         nid = le32_to_cpu(sum->nid);
 589         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 590
 591         node_page = f2fs_get_node_page(sbi, nid);
 592         if (IS_ERR(node_page))
 593                 return false;
 594
 595         if (f2fs_get_node_info(sbi, nid, dni)) {
 596                 f2fs_put_page(node_page, 1);
 597                 return false;
 598         }
 599
 600         if (sum->version != dni->version) {
 601                 f2fs_msg(sbi->sb, KERN_WARNING,
 602                                 "%s: valid data with mismatched node version.",
 603                                 __func__);
 604                 set_sbi_flag(sbi, SBI_NEED_FSCK);
 605         }
 606
 607         *nofs = ofs_of_node(node_page);
 608         source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
 609         f2fs_put_page(node_page, 1);
 610
 611         if (source_blkaddr != blkaddr)
 612                 return false;
 613         return true;
 614 }
 615
 616 static int ra_data_block(struct inode *inode, pgoff_t index)
 617 {
 618         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 619         struct address_space *mapping = inode->i_mapping;
 620         struct dnode_of_data dn;
 621         struct page *page;
 622         struct extent_info ei = {0, 0, 0};
 623         struct f2fs_io_info fio = {
 624                 .sbi = sbi,
 625                 .ino = inode->i_ino,
 626                 .type = DATA,
 627                 .temp = COLD,
 628                 .op = REQ_OP_READ,
 629                 .op_flags = 0,
 630                 .encrypted_page = NULL,
 631                 .in_list = false,
 632                 .retry = false,
 633         };
 634         int err;
 635
 636         page = f2fs_grab_cache_page(mapping, index, true);
 637         if (!page)
 638                 return -ENOMEM;
 639
 640         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 641                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 642                 goto got_it;
 643         }
 644
 645         set_new_dnode(&dn, inode, NULL, NULL, 0);
 646         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
 647         if (err)
 648                 goto put_page;
 649         f2fs_put_dnode(&dn);
 650
 651         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 652                                                 DATA_GENERIC))) {
 653                 err = -EFAULT;
 654                 goto put_page;
 655         }
 656 got_it:
 657         /* read page */
 658         fio.page = page;
 659         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 660
 661         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
 662                                         dn.data_blkaddr,
 663                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
 664         if (!fio.encrypted_page) {
 665                 err = -ENOMEM;
 666                 goto put_page;
 667         }
 668
 669         err = f2fs_submit_page_bio(&fio);
 670         if (err)
 671                 goto put_encrypted_page;
 672         f2fs_put_page(fio.encrypted_page, 0);
 673         f2fs_put_page(page, 1);
 674         return 0;
 675 put_encrypted_page:
 676         f2fs_put_page(fio.encrypted_page, 1);
 677 put_page:
 678         f2fs_put_page(page, 1);
 679         return err;
 680 }
 681
 682 /*
 683  * Move data block via META_MAPPING while keeping locked data page.
 684  * This can be used to move blocks, aka LBAs, directly on disk.
 685  */
 686 static int move_data_block(struct inode *inode, block_t bidx,
 687                                 int gc_type, unsigned int segno, int off)
 688 {
 689         struct f2fs_io_info fio = {
 690                 .sbi = F2FS_I_SB(inode),
 691                 .ino = inode->i_ino,
 692                 .type = DATA,
 693                 .temp = COLD,
 694                 .op = REQ_OP_READ,
 695                 .op_flags = 0,
 696                 .encrypted_page = NULL,
 697                 .in_list = false,
 698                 .retry = false,
 699         };
 700         struct dnode_of_data dn;
 701         struct f2fs_summary sum;
 702         struct node_info ni;
 703         struct page *page, *mpage;
 704         block_t newaddr;
 705         int err = 0;
 706         bool lfs_mode = test_opt(fio.sbi, LFS);
 707
 708         /* do not read out */
 709         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
 710         if (!page)
 711                 return -ENOMEM;
 712
 713         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 714                 err = -ENOENT;
 715                 goto out;
 716         }
 717
 718         if (f2fs_is_atomic_file(inode)) {
 719                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 720                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 721                 err = -EAGAIN;
 722                 goto out;
 723         }
 724
 725         if (f2fs_is_pinned_file(inode)) {
 726                 f2fs_pin_file_control(inode, true);
 727                 err = -EAGAIN;
 728                 goto out;
 729         }
 730
 731         set_new_dnode(&dn, inode, NULL, NULL, 0);
 732         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 733         if (err)
 734                 goto out;
 735
 736         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 737                 ClearPageUptodate(page);
 738                 err = -ENOENT;
 739                 goto put_out;
 740         }
 741
 742         /*
 743          * don't cache encrypted data into meta inode until previous dirty
 744          * data were writebacked to avoid racing between GC and flush.
 745          */
 746         f2fs_wait_on_page_writeback(page, DATA, true);
 747
 748         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 749         if (err)
 750                 goto put_out;
 751
 752         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
 753
 754         /* read page */
 755         fio.page = page;
 756         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 757
 758         if (lfs_mode)
 759                 down_write(&fio.sbi->io_order_lock);
 760
 761         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
 762                                         &sum, CURSEG_COLD_DATA, NULL, false);
 763
 764         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 765                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
 766         if (!fio.encrypted_page) {
 767                 err = -ENOMEM;
 768                 goto recover_block;
 769         }
 770
 771         mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 772                                         fio.old_blkaddr, FGP_LOCK, GFP_NOFS);
 773         if (mpage) {
 774                 bool updated = false;
 775
 776                 if (PageUptodate(mpage)) {
 777                         memcpy(page_address(fio.encrypted_page),
 778                                         page_address(mpage), PAGE_SIZE);
 779                         updated = true;
 780                 }
 781                 f2fs_put_page(mpage, 1);
 782                 invalidate_mapping_pages(META_MAPPING(fio.sbi),
 783                                         fio.old_blkaddr, fio.old_blkaddr);
 784                 if (updated)
 785                         goto write_page;
 786         }
 787
 788         err = f2fs_submit_page_bio(&fio);
 789         if (err)
 790                 goto put_page_out;
 791
 792         /* write page */
 793         lock_page(fio.encrypted_page);
 794
 795         if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
 796                 err = -EIO;
 797                 goto put_page_out;
 798         }
 799         if (unlikely(!PageUptodate(fio.encrypted_page))) {
 800                 err = -EIO;
 801                 goto put_page_out;
 802         }
 803
 804 write_page:
 805         set_page_dirty(fio.encrypted_page);
 806         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
 807         if (clear_page_dirty_for_io(fio.encrypted_page))
 808                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
 809
 810         set_page_writeback(fio.encrypted_page);
 811         ClearPageError(page);
 812
 813         /* allocate block address */
 814         f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
 815
 816         fio.op = REQ_OP_WRITE;
 817         fio.op_flags = REQ_SYNC;
 818         fio.new_blkaddr = newaddr;
 819         f2fs_submit_page_write(&fio);
 820         if (fio.retry) {
 821                 err = -EAGAIN;
 822                 if (PageWriteback(fio.encrypted_page))
 823                         end_page_writeback(fio.encrypted_page);
 824                 goto put_page_out;
 825         }
 826
 827         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
 828
 829         f2fs_update_data_blkaddr(&dn, newaddr);
 830         set_inode_flag(inode, FI_APPEND_WRITE);
 831         if (page->index == 0)
 832                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 833 put_page_out:
 834         f2fs_put_page(fio.encrypted_page, 1);
 835 recover_block:
 836         if (lfs_mode)
 837                 up_write(&fio.sbi->io_order_lock);
 838         if (err)
 839                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
 840                                                                 true, true);
 841 put_out:
 842         f2fs_put_dnode(&dn);
 843 out:
 844         f2fs_put_page(page, 1);
 845         return err;
 846 }
 847
 848 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
 849                                                         unsigned int segno, int off)
 850 {
 851         struct page *page;
 852         int err = 0;
 853
 854         page = f2fs_get_lock_data_page(inode, bidx, true);
 855         if (IS_ERR(page))
 856                 return PTR_ERR(page);
 857
 858         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 859                 err = -ENOENT;
 860                 goto out;
 861         }
 862
 863         if (f2fs_is_atomic_file(inode)) {
 864                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 865                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 866                 err = -EAGAIN;
 867                 goto out;
 868         }
 869         if (f2fs_is_pinned_file(inode)) {
 870                 if (gc_type == FG_GC)
 871                         f2fs_pin_file_control(inode, true);
 872                 err = -EAGAIN;
 873                 goto out;
 874         }
 875
 876         if (gc_type == BG_GC) {
 877                 if (PageWriteback(page)) {
 878                         err = -EAGAIN;
 879                         goto out;
 880                 }
 881                 set_page_dirty(page);
 882                 set_cold_data(page);
 883         } else {
 884                 struct f2fs_io_info fio = {
 885                         .sbi = F2FS_I_SB(inode),
 886                         .ino = inode->i_ino,
 887                         .type = DATA,
 888                         .temp = COLD,
 889                         .op = REQ_OP_WRITE,
 890                         .op_flags = REQ_SYNC,
 891                         .old_blkaddr = NULL_ADDR,
 892                         .page = page,
 893                         .encrypted_page = NULL,
 894                         .need_lock = LOCK_REQ,
 895                         .io_type = FS_GC_DATA_IO,
 896                 };
 897                 bool is_dirty = PageDirty(page);
 898
 899 retry:
 900                 set_page_dirty(page);
 901                 f2fs_wait_on_page_writeback(page, DATA, true);
 902                 if (clear_page_dirty_for_io(page)) {
 903                         inode_dec_dirty_pages(inode);
 904                         f2fs_remove_dirty_inode(inode);
 905                 }
 906
 907                 set_cold_data(page);
 908
 909                 err = f2fs_do_write_data_page(&fio);
 910                 if (err) {
 911                         clear_cold_data(page);
 912                         if (err == -ENOMEM) {
 913                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 914                                 goto retry;
 915                         }
 916                         if (is_dirty)
 917                                 set_page_dirty(page);
 918                 }
 919         }
 920 out:
 921         f2fs_put_page(page, 1);
 922         return err;
 923 }
 924
 925 /*
 926  * This function tries to get parent node of victim data block, and identifies
 927  * data block validity. If the block is valid, copy that with cold status and
 928  * modify parent node.
 929  * If the parent node is not valid or the data block address is different,
 930  * the victim data block is ignored.
 931  */
 932 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 933                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
 934 {
 935         struct super_block *sb = sbi->sb;
 936         struct f2fs_summary *entry;
 937         block_t start_addr;
 938         int off;
 939         int phase = 0;
 940         int submitted = 0;
 941
 942         start_addr = START_BLOCK(sbi, segno);
 943
 944 next_step:
 945         entry = sum;
 946
 947         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 948                 struct page *data_page;
 949                 struct inode *inode;
 950                 struct node_info dni; /* dnode info for the data */
 951                 unsigned int ofs_in_node, nofs;
 952                 block_t start_bidx;
 953                 nid_t nid = le32_to_cpu(entry->nid);
 954
 955                 /* stop BG_GC if there is not enough free sections. */
 956                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 957                         return submitted;
 958
 959                 if (check_valid_map(sbi, segno, off) == 0)
 960                         continue;
 961
 962                 if (phase == 0) {
 963                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 964                                                         META_NAT, true);
 965                         continue;
 966                 }
 967
 968                 if (phase == 1) {
 969                         f2fs_ra_node_page(sbi, nid);
 970                         continue;
 971                 }
 972
 973                 /* Get an inode by ino with checking validity */
 974                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
 975                         continue;
 976
 977                 if (phase == 2) {
 978                         f2fs_ra_node_page(sbi, dni.ino);
 979                         continue;
 980                 }
 981
 982                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
 983
 984                 if (phase == 3) {
 985                         inode = f2fs_iget(sb, dni.ino);
 986                         if (IS_ERR(inode) || is_bad_inode(inode))
 987                                 continue;
 988
 989                         if (!down_write_trylock(
 990                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
 991                                 iput(inode);
 992                                 sbi->skipped_gc_rwsem++;
 993                                 continue;
 994                         }
 995
 996                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
 997                                                                 ofs_in_node;
 998
 999                         if (f2fs_post_read_required(inode)) {
1000                                 int err = ra_data_block(inode, start_bidx);
1001
1002                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1003                                 if (err) {
1004                                         iput(inode);
1005                                         continue;
1006                                 }
1007                                 add_gc_inode(gc_list, inode);
1008                                 continue;
1009                         }
1010
1011                         data_page = f2fs_get_read_data_page(inode,
1012                                                 start_bidx, REQ_RAHEAD, true);
1013                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1014                         if (IS_ERR(data_page)) {
1015                                 iput(inode);
1016                                 continue;
1017                         }
1018
1019                         f2fs_put_page(data_page, 0);
1020                         add_gc_inode(gc_list, inode);
1021                         continue;
1022                 }
1023
1024                 /* phase 4 */
1025                 inode = find_gc_inode(gc_list, dni.ino);
1026                 if (inode) {
1027                         struct f2fs_inode_info *fi = F2FS_I(inode);
1028                         bool locked = false;
1029                         int err;
1030
1031                         if (S_ISREG(inode->i_mode)) {
1032                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1033                                         continue;
1034                                 if (!down_write_trylock(
1035                                                 &fi->i_gc_rwsem[WRITE])) {
1036                                         sbi->skipped_gc_rwsem++;
1037                                         up_write(&fi->i_gc_rwsem[READ]);
1038                                         continue;
1039                                 }
1040                                 locked = true;
1041
1042                                 /* wait for all inflight aio data */
1043                                 inode_dio_wait(inode);
1044                         }
1045
1046                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1047                                                                 + ofs_in_node;
1048                         if (f2fs_post_read_required(inode))
1049                                 err = move_data_block(inode, start_bidx,
1050                                                         gc_type, segno, off);
1051                         else
1052                                 err = move_data_page(inode, start_bidx, gc_type,
1053                                                                 segno, off);
1054
1055                         if (!err && (gc_type == FG_GC ||
1056                                         f2fs_post_read_required(inode)))
1057                                 submitted++;
1058
1059                         if (locked) {
1060                                 up_write(&fi->i_gc_rwsem[WRITE]);
1061                                 up_write(&fi->i_gc_rwsem[READ]);
1062                         }
1063
1064                         stat_inc_data_blk_count(sbi, 1, gc_type);
1065                 }
1066         }
1067
1068         if (++phase < 5)
1069                 goto next_step;
1070
1071         return submitted;
1072 }
1073
1074 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1075                         int gc_type)
1076 {
1077         struct sit_info *sit_i = SIT_I(sbi);
1078         int ret;
1079
1080         down_write(&sit_i->sentry_lock);
1081         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1082                                               NO_CHECK_TYPE, LFS);
1083         up_write(&sit_i->sentry_lock);
1084         return ret;
1085 }
1086
1087 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1088                                 unsigned int start_segno,
1089                                 struct gc_inode_list *gc_list, int gc_type)
1090 {
1091         struct page *sum_page;
1092         struct f2fs_summary_block *sum;
1093         struct blk_plug plug;
1094         unsigned int segno = start_segno;
1095         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1096         int seg_freed = 0;
1097         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1098                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1099         int submitted = 0;
1100
1101         /* readahead multi ssa blocks those have contiguous address */
1102         if (sbi->segs_per_sec > 1)
1103                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1104                                         sbi->segs_per_sec, META_SSA, true);
1105
1106         /* reference all summary page */
1107         while (segno < end_segno) {
1108                 sum_page = f2fs_get_sum_page(sbi, segno++);
1109                 if (IS_ERR(sum_page)) {
1110                         int err = PTR_ERR(sum_page);
1111
1112                         end_segno = segno - 1;
1113                         for (segno = start_segno; segno < end_segno; segno++) {
1114                                 sum_page = find_get_page(META_MAPPING(sbi),
1115                                                 GET_SUM_BLOCK(sbi, segno));
1116                                 f2fs_put_page(sum_page, 0);
1117                                 f2fs_put_page(sum_page, 0);
1118                         }
1119                         return err;
1120                 }
1121                 unlock_page(sum_page);
1122         }
1123
1124         blk_start_plug(&plug);
1125
1126         for (segno = start_segno; segno < end_segno; segno++) {
1127
1128                 /* find segment summary of victim */
1129                 sum_page = find_get_page(META_MAPPING(sbi),
1130                                         GET_SUM_BLOCK(sbi, segno));
1131                 f2fs_put_page(sum_page, 0);
1132
1133                 if (get_valid_blocks(sbi, segno, false) == 0 ||
1134                                 !PageUptodate(sum_page) ||
1135                                 unlikely(f2fs_cp_error(sbi)))
1136                         goto next;
1137
1138                 sum = page_address(sum_page);
1139                 if (type != GET_SUM_TYPE((&sum->footer))) {
1140                         f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) "
1141                                 "type [%d, %d] in SSA and SIT",
1142                                 segno, type, GET_SUM_TYPE((&sum->footer)));
1143                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1144                         goto next;
1145                 }
1146
1147                 /*
1148                  * this is to avoid deadlock:
1149                  * - lock_page(sum_page)         - f2fs_replace_block
1150                  *  - check_valid_map()            - down_write(sentry_lock)
1151                  *   - down_read(sentry_lock)     - change_curseg()
1152                  *                                  - lock_page(sum_page)
1153                  */
1154                 if (type == SUM_TYPE_NODE)
1155                         submitted += gc_node_segment(sbi, sum->entries, segno,
1156                                                                 gc_type);
1157                 else
1158                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1159                                                         segno, gc_type);
1160
1161                 stat_inc_seg_count(sbi, type, gc_type);
1162
1163                 if (gc_type == FG_GC &&
1164                                 get_valid_blocks(sbi, segno, false) == 0)
1165                         seg_freed++;
1166 next:
1167                 f2fs_put_page(sum_page, 0);
1168         }
1169
1170         if (submitted)
1171                 f2fs_submit_merged_write(sbi,
1172                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1173
1174         blk_finish_plug(&plug);
1175
1176         stat_inc_call_count(sbi->stat_info);
1177
1178         return seg_freed;
1179 }
1180
1181 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1182                         bool background, unsigned int segno)
1183 {
1184         int gc_type = sync ? FG_GC : BG_GC;
1185         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1186         int ret = 0;
1187         struct cp_control cpc;
1188         unsigned int init_segno = segno;
1189         struct gc_inode_list gc_list = {
1190                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1191                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1192         };
1193         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1194         unsigned long long first_skipped;
1195         unsigned int skipped_round = 0, round = 0;
1196
1197         trace_f2fs_gc_begin(sbi->sb, sync, background,
1198                                 get_pages(sbi, F2FS_DIRTY_NODES),
1199                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1200                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1201                                 free_sections(sbi),
1202                                 free_segments(sbi),
1203                                 reserved_segments(sbi),
1204                                 prefree_segments(sbi));
1205
1206         cpc.reason = __get_cp_reason(sbi);
1207         sbi->skipped_gc_rwsem = 0;
1208         first_skipped = last_skipped;
1209 gc_more:
1210         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1211                 ret = -EINVAL;
1212                 goto stop;
1213         }
1214         if (unlikely(f2fs_cp_error(sbi))) {
1215                 ret = -EIO;
1216                 goto stop;
1217         }
1218
1219         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1220                 /*
1221                  * For example, if there are many prefree_segments below given
1222                  * threshold, we can make them free by checkpoint. Then, we
1223                  * secure free segments which doesn't need fggc any more.
1224                  */
1225                 if (prefree_segments(sbi) &&
1226                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1227                         ret = f2fs_write_checkpoint(sbi, &cpc);
1228                         if (ret)
1229                                 goto stop;
1230                 }
1231                 if (has_not_enough_free_secs(sbi, 0, 0))
1232                         gc_type = FG_GC;
1233         }
1234
1235         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1236         if (gc_type == BG_GC && !background) {
1237                 ret = -EINVAL;
1238                 goto stop;
1239         }
1240         if (!__get_victim(sbi, &segno, gc_type)) {
1241                 ret = -ENODATA;
1242                 goto stop;
1243         }
1244
1245         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1246         if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1247                 sec_freed++;
1248         total_freed += seg_freed;
1249
1250         if (gc_type == FG_GC) {
1251                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1252                                                 sbi->skipped_gc_rwsem)
1253                         skipped_round++;
1254                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1255                 round++;
1256         }
1257
1258         if (gc_type == FG_GC)
1259                 sbi->cur_victim_sec = NULL_SEGNO;
1260
1261         if (sync)
1262                 goto stop;
1263
1264         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1265                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1266                                         skipped_round * 2 < round) {
1267                         segno = NULL_SEGNO;
1268                         goto gc_more;
1269                 }
1270
1271                 if (first_skipped < last_skipped &&
1272                                 (last_skipped - first_skipped) >
1273                                                 sbi->skipped_gc_rwsem) {
1274                         f2fs_drop_inmem_pages_all(sbi, true);
1275                         segno = NULL_SEGNO;
1276                         goto gc_more;
1277                 }
1278                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1279                         ret = f2fs_write_checkpoint(sbi, &cpc);
1280         }
1281 stop:
1282         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1283         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1284
1285         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1286                                 get_pages(sbi, F2FS_DIRTY_NODES),
1287                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1288                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1289                                 free_sections(sbi),
1290                                 free_segments(sbi),
1291                                 reserved_segments(sbi),
1292                                 prefree_segments(sbi));
1293
1294         mutex_unlock(&sbi->gc_mutex);
1295
1296         put_gc_inode(&gc_list);
1297
1298         if (sync && !ret)
1299                 ret = sec_freed ? 0 : -EAGAIN;
1300         return ret;
1301 }
1302
1303 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1304 {
1305         DIRTY_I(sbi)->v_ops = &default_v_ops;
1306
1307         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1308
1309         /* give warm/cold data area from slower device */
1310         if (sbi->s_ndevs && sbi->segs_per_sec == 1)
1311                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1312                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1313 }