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                 bool sync_mode;
  35
  36                 wait_event_interruptible_timeout(*wq,
  37                                 kthread_should_stop() || freezing(current) ||
  38                                 gc_th->gc_wake,
  39                                 msecs_to_jiffies(wait_ms));
  40
  41                 /* give it a try one time */
  42                 if (gc_th->gc_wake)
  43                         gc_th->gc_wake = 0;
  44
  45                 if (try_to_freeze()) {
  46                         stat_other_skip_bggc_count(sbi);
  47                         continue;
  48                 }
  49                 if (kthread_should_stop())
  50                         break;
  51
  52                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  53                         increase_sleep_time(gc_th, &wait_ms);
  54                         stat_other_skip_bggc_count(sbi);
  55                         continue;
  56                 }
  57
  58                 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
  59                         f2fs_show_injection_info(sbi, FAULT_CHECKPOINT);
  60                         f2fs_stop_checkpoint(sbi, false);
  61                 }
  62
  63                 if (!sb_start_write_trylock(sbi->sb)) {
  64                         stat_other_skip_bggc_count(sbi);
  65                         continue;
  66                 }
  67
  68                 /*
  69                  * [GC triggering condition]
  70                  * 0. GC is not conducted currently.
  71                  * 1. There are enough dirty segments.
  72                  * 2. IO subsystem is idle by checking the # of writeback pages.
  73                  * 3. IO subsystem is idle by checking the # of requests in
  74                  *    bdev's request list.
  75                  *
  76                  * Note) We have to avoid triggering GCs frequently.
  77                  * Because it is possible that some segments can be
  78                  * invalidated soon after by user update or deletion.
  79                  * So, I'd like to wait some time to collect dirty segments.
  80                  */
  81                 if (sbi->gc_mode == GC_URGENT) {
  82                         wait_ms = gc_th->urgent_sleep_time;
  83                         down_write(&sbi->gc_lock);
  84                         goto do_gc;
  85                 }
  86
  87                 if (!down_write_trylock(&sbi->gc_lock)) {
  88                         stat_other_skip_bggc_count(sbi);
  89                         goto next;
  90                 }
  91
  92                 if (!is_idle(sbi, GC_TIME)) {
  93                         increase_sleep_time(gc_th, &wait_ms);
  94                         up_write(&sbi->gc_lock);
  95                         stat_io_skip_bggc_count(sbi);
  96                         goto next;
  97                 }
  98
  99                 if (has_enough_invalid_blocks(sbi))
 100                         decrease_sleep_time(gc_th, &wait_ms);
 101                 else
 102                         increase_sleep_time(gc_th, &wait_ms);
 103 do_gc:
 104                 stat_inc_bggc_count(sbi->stat_info);
 105
 106                 sync_mode = F2FS_OPTION(sbi).bggc_mode == BGGC_MODE_SYNC;
 107
 108                 /* if return value is not zero, no victim was selected */
 109                 if (f2fs_gc(sbi, sync_mode, true, NULL_SEGNO))
 110                         wait_ms = gc_th->no_gc_sleep_time;
 111
 112                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 113                                 prefree_segments(sbi), free_segments(sbi));
 114
 115                 /* balancing f2fs's metadata periodically */
 116                 f2fs_balance_fs_bg(sbi, true);
 117 next:
 118                 sb_end_write(sbi->sb);
 119
 120         } while (!kthread_should_stop());
 121         return 0;
 122 }
 123
 124 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 125 {
 126         struct f2fs_gc_kthread *gc_th;
 127         dev_t dev = sbi->sb->s_bdev->bd_dev;
 128         int err = 0;
 129
 130         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 131         if (!gc_th) {
 132                 err = -ENOMEM;
 133                 goto out;
 134         }
 135
 136         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 137         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 138         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 139         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 140
 141         gc_th->gc_wake= 0;
 142
 143         sbi->gc_thread = gc_th;
 144         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 145         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 146                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 147         if (IS_ERR(gc_th->f2fs_gc_task)) {
 148                 err = PTR_ERR(gc_th->f2fs_gc_task);
 149                 kvfree(gc_th);
 150                 sbi->gc_thread = NULL;
 151         }
 152 out:
 153         return err;
 154 }
 155
 156 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 157 {
 158         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 159         if (!gc_th)
 160                 return;
 161         kthread_stop(gc_th->f2fs_gc_task);
 162         kvfree(gc_th);
 163         sbi->gc_thread = NULL;
 164 }
 165
 166 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 167 {
 168         int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
 169
 170         switch (sbi->gc_mode) {
 171         case GC_IDLE_CB:
 172                 gc_mode = GC_CB;
 173                 break;
 174         case GC_IDLE_GREEDY:
 175         case GC_URGENT:
 176                 gc_mode = GC_GREEDY;
 177                 break;
 178         }
 179         return gc_mode;
 180 }
 181
 182 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 183                         int type, struct victim_sel_policy *p)
 184 {
 185         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 186
 187         if (p->alloc_mode == SSR) {
 188                 p->gc_mode = GC_GREEDY;
 189                 p->dirty_segmap = dirty_i->dirty_segmap[type];
 190                 p->max_search = dirty_i->nr_dirty[type];
 191                 p->ofs_unit = 1;
 192         } else {
 193                 p->gc_mode = select_gc_type(sbi, gc_type);
 194                 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
 195                 p->max_search = dirty_i->nr_dirty[DIRTY];
 196                 p->ofs_unit = sbi->segs_per_sec;
 197         }
 198
 199         /*
 200          * adjust candidates range, should select all dirty segments for
 201          * foreground GC and urgent GC cases.
 202          */
 203         if (gc_type != FG_GC &&
 204                         (sbi->gc_mode != GC_URGENT) &&
 205                         p->max_search > sbi->max_victim_search)
 206                 p->max_search = sbi->max_victim_search;
 207
 208         /* let's select beginning hot/small space first in no_heap mode*/
 209         if (test_opt(sbi, NOHEAP) &&
 210                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 211                 p->offset = 0;
 212         else
 213                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 214 }
 215
 216 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 217                                 struct victim_sel_policy *p)
 218 {
 219         /* SSR allocates in a segment unit */
 220         if (p->alloc_mode == SSR)
 221                 return sbi->blocks_per_seg;
 222         if (p->gc_mode == GC_GREEDY)
 223                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 224         else if (p->gc_mode == GC_CB)
 225                 return UINT_MAX;
 226         else /* No other gc_mode */
 227                 return 0;
 228 }
 229
 230 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 231 {
 232         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 233         unsigned int secno;
 234
 235         /*
 236          * If the gc_type is FG_GC, we can select victim segments
 237          * selected by background GC before.
 238          * Those segments guarantee they have small valid blocks.
 239          */
 240         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 241                 if (sec_usage_check(sbi, secno))
 242                         continue;
 243                 clear_bit(secno, dirty_i->victim_secmap);
 244                 return GET_SEG_FROM_SEC(sbi, secno);
 245         }
 246         return NULL_SEGNO;
 247 }
 248
 249 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 250 {
 251         struct sit_info *sit_i = SIT_I(sbi);
 252         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 253         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 254         unsigned long long mtime = 0;
 255         unsigned int vblocks;
 256         unsigned char age = 0;
 257         unsigned char u;
 258         unsigned int i;
 259
 260         for (i = 0; i < sbi->segs_per_sec; i++)
 261                 mtime += get_seg_entry(sbi, start + i)->mtime;
 262         vblocks = get_valid_blocks(sbi, segno, true);
 263
 264         mtime = div_u64(mtime, sbi->segs_per_sec);
 265         vblocks = div_u64(vblocks, sbi->segs_per_sec);
 266
 267         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 268
 269         /* Handle if the system time has changed by the user */
 270         if (mtime < sit_i->min_mtime)
 271                 sit_i->min_mtime = mtime;
 272         if (mtime > sit_i->max_mtime)
 273                 sit_i->max_mtime = mtime;
 274         if (sit_i->max_mtime != sit_i->min_mtime)
 275                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 276                                 sit_i->max_mtime - sit_i->min_mtime);
 277
 278         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 279 }
 280
 281 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 282                         unsigned int segno, struct victim_sel_policy *p)
 283 {
 284         if (p->alloc_mode == SSR)
 285                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 286
 287         /* alloc_mode == LFS */
 288         if (p->gc_mode == GC_GREEDY)
 289                 return get_valid_blocks(sbi, segno, true);
 290         else
 291                 return get_cb_cost(sbi, segno);
 292 }
 293
 294 static unsigned int count_bits(const unsigned long *addr,
 295                                 unsigned int offset, unsigned int len)
 296 {
 297         unsigned int end = offset + len, sum = 0;
 298
 299         while (offset < end) {
 300                 if (test_bit(offset++, addr))
 301                         ++sum;
 302         }
 303         return sum;
 304 }
 305
 306 /*
 307  * This function is called from two paths.
 308  * One is garbage collection and the other is SSR segment selection.
 309  * When it is called during GC, it just gets a victim segment
 310  * and it does not remove it from dirty seglist.
 311  * When it is called from SSR segment selection, it finds a segment
 312  * which has minimum valid blocks and removes it from dirty seglist.
 313  */
 314 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 315                 unsigned int *result, int gc_type, int type, char alloc_mode)
 316 {
 317         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 318         struct sit_info *sm = SIT_I(sbi);
 319         struct victim_sel_policy p;
 320         unsigned int secno, last_victim;
 321         unsigned int last_segment;
 322         unsigned int nsearched = 0;
 323
 324         mutex_lock(&dirty_i->seglist_lock);
 325         last_segment = MAIN_SECS(sbi) * sbi->segs_per_sec;
 326
 327         p.alloc_mode = alloc_mode;
 328         select_policy(sbi, gc_type, type, &p);
 329
 330         p.min_segno = NULL_SEGNO;
 331         p.min_cost = get_max_cost(sbi, &p);
 332
 333         if (*result != NULL_SEGNO) {
 334                 if (get_valid_blocks(sbi, *result, false) &&
 335                         !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 336                         p.min_segno = *result;
 337                 goto out;
 338         }
 339
 340         if (p.max_search == 0)
 341                 goto out;
 342
 343         if (__is_large_section(sbi) && p.alloc_mode == LFS) {
 344                 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) {
 345                         p.min_segno = sbi->next_victim_seg[BG_GC];
 346                         *result = p.min_segno;
 347                         sbi->next_victim_seg[BG_GC] = NULL_SEGNO;
 348                         goto got_result;
 349                 }
 350                 if (gc_type == FG_GC &&
 351                                 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) {
 352                         p.min_segno = sbi->next_victim_seg[FG_GC];
 353                         *result = p.min_segno;
 354                         sbi->next_victim_seg[FG_GC] = NULL_SEGNO;
 355                         goto got_result;
 356                 }
 357         }
 358
 359         last_victim = sm->last_victim[p.gc_mode];
 360         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 361                 p.min_segno = check_bg_victims(sbi);
 362                 if (p.min_segno != NULL_SEGNO)
 363                         goto got_it;
 364         }
 365
 366         while (1) {
 367                 unsigned long cost;
 368                 unsigned int segno;
 369
 370                 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
 371                 if (segno >= last_segment) {
 372                         if (sm->last_victim[p.gc_mode]) {
 373                                 last_segment =
 374                                         sm->last_victim[p.gc_mode];
 375                                 sm->last_victim[p.gc_mode] = 0;
 376                                 p.offset = 0;
 377                                 continue;
 378                         }
 379                         break;
 380                 }
 381
 382                 p.offset = segno + p.ofs_unit;
 383                 if (p.ofs_unit > 1) {
 384                         p.offset -= segno % p.ofs_unit;
 385                         nsearched += count_bits(p.dirty_segmap,
 386                                                 p.offset - p.ofs_unit,
 387                                                 p.ofs_unit);
 388                 } else {
 389                         nsearched++;
 390                 }
 391
 392 #ifdef CONFIG_F2FS_CHECK_FS
 393                 /*
 394                  * skip selecting the invalid segno (that is failed due to block
 395                  * validity check failure during GC) to avoid endless GC loop in
 396                  * such cases.
 397                  */
 398                 if (test_bit(segno, sm->invalid_segmap))
 399                         goto next;
 400 #endif
 401
 402                 secno = GET_SEC_FROM_SEG(sbi, segno);
 403
 404                 if (sec_usage_check(sbi, secno))
 405                         goto next;
 406                 /* Don't touch checkpointed data */
 407                 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
 408                                         get_ckpt_valid_blocks(sbi, segno) &&
 409                                         p.alloc_mode != SSR))
 410                         goto next;
 411                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 412                         goto next;
 413
 414                 cost = get_gc_cost(sbi, segno, &p);
 415
 416                 if (p.min_cost > cost) {
 417                         p.min_segno = segno;
 418                         p.min_cost = cost;
 419                 }
 420 next:
 421                 if (nsearched >= p.max_search) {
 422                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 423                                 sm->last_victim[p.gc_mode] = last_victim + 1;
 424                         else
 425                                 sm->last_victim[p.gc_mode] = segno + 1;
 426                         sm->last_victim[p.gc_mode] %=
 427                                 (MAIN_SECS(sbi) * sbi->segs_per_sec);
 428                         break;
 429                 }
 430         }
 431         if (p.min_segno != NULL_SEGNO) {
 432 got_it:
 433                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 434 got_result:
 435                 if (p.alloc_mode == LFS) {
 436                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 437                         if (gc_type == FG_GC)
 438                                 sbi->cur_victim_sec = secno;
 439                         else
 440                                 set_bit(secno, dirty_i->victim_secmap);
 441                 }
 442
 443         }
 444 out:
 445         if (p.min_segno != NULL_SEGNO)
 446                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 447                                 sbi->cur_victim_sec,
 448                                 prefree_segments(sbi), free_segments(sbi));
 449         mutex_unlock(&dirty_i->seglist_lock);
 450
 451         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 452 }
 453
 454 static const struct victim_selection default_v_ops = {
 455         .get_victim = get_victim_by_default,
 456 };
 457
 458 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 459 {
 460         struct inode_entry *ie;
 461
 462         ie = radix_tree_lookup(&gc_list->iroot, ino);
 463         if (ie)
 464                 return ie->inode;
 465         return NULL;
 466 }
 467
 468 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 469 {
 470         struct inode_entry *new_ie;
 471
 472         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 473                 iput(inode);
 474                 return;
 475         }
 476         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 477         new_ie->inode = inode;
 478
 479         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 480         list_add_tail(&new_ie->list, &gc_list->ilist);
 481 }
 482
 483 static void put_gc_inode(struct gc_inode_list *gc_list)
 484 {
 485         struct inode_entry *ie, *next_ie;
 486         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 487                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 488                 iput(ie->inode);
 489                 list_del(&ie->list);
 490                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 491         }
 492 }
 493
 494 static int check_valid_map(struct f2fs_sb_info *sbi,
 495                                 unsigned int segno, int offset)
 496 {
 497         struct sit_info *sit_i = SIT_I(sbi);
 498         struct seg_entry *sentry;
 499         int ret;
 500
 501         down_read(&sit_i->sentry_lock);
 502         sentry = get_seg_entry(sbi, segno);
 503         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 504         up_read(&sit_i->sentry_lock);
 505         return ret;
 506 }
 507
 508 /*
 509  * This function compares node address got in summary with that in NAT.
 510  * On validity, copy that node with cold status, otherwise (invalid node)
 511  * ignore that.
 512  */
 513 static int gc_node_segment(struct f2fs_sb_info *sbi,
 514                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 515 {
 516         struct f2fs_summary *entry;
 517         block_t start_addr;
 518         int off;
 519         int phase = 0;
 520         bool fggc = (gc_type == FG_GC);
 521         int submitted = 0;
 522
 523         start_addr = START_BLOCK(sbi, segno);
 524
 525 next_step:
 526         entry = sum;
 527
 528         if (fggc && phase == 2)
 529                 atomic_inc(&sbi->wb_sync_req[NODE]);
 530
 531         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 532                 nid_t nid = le32_to_cpu(entry->nid);
 533                 struct page *node_page;
 534                 struct node_info ni;
 535                 int err;
 536
 537                 /* stop BG_GC if there is not enough free sections. */
 538                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 539                         return submitted;
 540
 541                 if (check_valid_map(sbi, segno, off) == 0)
 542                         continue;
 543
 544                 if (phase == 0) {
 545                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 546                                                         META_NAT, true);
 547                         continue;
 548                 }
 549
 550                 if (phase == 1) {
 551                         f2fs_ra_node_page(sbi, nid);
 552                         continue;
 553                 }
 554
 555                 /* phase == 2 */
 556                 node_page = f2fs_get_node_page(sbi, nid);
 557                 if (IS_ERR(node_page))
 558                         continue;
 559
 560                 /* block may become invalid during f2fs_get_node_page */
 561                 if (check_valid_map(sbi, segno, off) == 0) {
 562                         f2fs_put_page(node_page, 1);
 563                         continue;
 564                 }
 565
 566                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 567                         f2fs_put_page(node_page, 1);
 568                         continue;
 569                 }
 570
 571                 if (ni.blk_addr != start_addr + off) {
 572                         f2fs_put_page(node_page, 1);
 573                         continue;
 574                 }
 575
 576                 err = f2fs_move_node_page(node_page, gc_type);
 577                 if (!err && gc_type == FG_GC)
 578                         submitted++;
 579                 stat_inc_node_blk_count(sbi, 1, gc_type);
 580         }
 581
 582         if (++phase < 3)
 583                 goto next_step;
 584
 585         if (fggc)
 586                 atomic_dec(&sbi->wb_sync_req[NODE]);
 587         return submitted;
 588 }
 589
 590 /*
 591  * Calculate start block index indicating the given node offset.
 592  * Be careful, caller should give this node offset only indicating direct node
 593  * blocks. If any node offsets, which point the other types of node blocks such
 594  * as indirect or double indirect node blocks, are given, it must be a caller's
 595  * bug.
 596  */
 597 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 598 {
 599         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 600         unsigned int bidx;
 601
 602         if (node_ofs == 0)
 603                 return 0;
 604
 605         if (node_ofs <= 2) {
 606                 bidx = node_ofs - 1;
 607         } else if (node_ofs <= indirect_blks) {
 608                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 609                 bidx = node_ofs - 2 - dec;
 610         } else {
 611                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 612                 bidx = node_ofs - 5 - dec;
 613         }
 614         return bidx * ADDRS_PER_BLOCK(inode) + ADDRS_PER_INODE(inode);
 615 }
 616
 617 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 618                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 619 {
 620         struct page *node_page;
 621         nid_t nid;
 622         unsigned int ofs_in_node;
 623         block_t source_blkaddr;
 624
 625         nid = le32_to_cpu(sum->nid);
 626         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 627
 628         node_page = f2fs_get_node_page(sbi, nid);
 629         if (IS_ERR(node_page))
 630                 return false;
 631
 632         if (f2fs_get_node_info(sbi, nid, dni)) {
 633                 f2fs_put_page(node_page, 1);
 634                 return false;
 635         }
 636
 637         if (sum->version != dni->version) {
 638                 f2fs_warn(sbi, "%s: valid data with mismatched node version.",
 639                           __func__);
 640                 set_sbi_flag(sbi, SBI_NEED_FSCK);
 641         }
 642
 643         *nofs = ofs_of_node(node_page);
 644         source_blkaddr = data_blkaddr(NULL, node_page, ofs_in_node);
 645         f2fs_put_page(node_page, 1);
 646
 647         if (source_blkaddr != blkaddr) {
 648 #ifdef CONFIG_F2FS_CHECK_FS
 649                 unsigned int segno = GET_SEGNO(sbi, blkaddr);
 650                 unsigned long offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
 651
 652                 if (unlikely(check_valid_map(sbi, segno, offset))) {
 653                         if (!test_and_set_bit(segno, SIT_I(sbi)->invalid_segmap)) {
 654                                 f2fs_err(sbi, "mismatched blkaddr %u (source_blkaddr %u) in seg %u\n",
 655                                                 blkaddr, source_blkaddr, segno);
 656                                 f2fs_bug_on(sbi, 1);
 657                         }
 658                 }
 659 #endif
 660                 return false;
 661         }
 662         return true;
 663 }
 664
 665 static int ra_data_block(struct inode *inode, pgoff_t index)
 666 {
 667         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 668         struct address_space *mapping = inode->i_mapping;
 669         struct dnode_of_data dn;
 670         struct page *page;
 671         struct extent_info ei = {0, 0, 0};
 672         struct f2fs_io_info fio = {
 673                 .sbi = sbi,
 674                 .ino = inode->i_ino,
 675                 .type = DATA,
 676                 .temp = COLD,
 677                 .op = REQ_OP_READ,
 678                 .op_flags = 0,
 679                 .encrypted_page = NULL,
 680                 .in_list = false,
 681                 .retry = false,
 682         };
 683         int err;
 684
 685         page = f2fs_grab_cache_page(mapping, index, true);
 686         if (!page)
 687                 return -ENOMEM;
 688
 689         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 690                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 691                 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 692                                                 DATA_GENERIC_ENHANCE_READ))) {
 693                         err = -EFSCORRUPTED;
 694                         goto put_page;
 695                 }
 696                 goto got_it;
 697         }
 698
 699         set_new_dnode(&dn, inode, NULL, NULL, 0);
 700         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
 701         if (err)
 702                 goto put_page;
 703         f2fs_put_dnode(&dn);
 704
 705         if (!__is_valid_data_blkaddr(dn.data_blkaddr)) {
 706                 err = -ENOENT;
 707                 goto put_page;
 708         }
 709         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 710                                                 DATA_GENERIC_ENHANCE))) {
 711                 err = -EFSCORRUPTED;
 712                 goto put_page;
 713         }
 714 got_it:
 715         /* read page */
 716         fio.page = page;
 717         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 718
 719         /*
 720          * don't cache encrypted data into meta inode until previous dirty
 721          * data were writebacked to avoid racing between GC and flush.
 722          */
 723         f2fs_wait_on_page_writeback(page, DATA, true, true);
 724
 725         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
 726
 727         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
 728                                         dn.data_blkaddr,
 729                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
 730         if (!fio.encrypted_page) {
 731                 err = -ENOMEM;
 732                 goto put_page;
 733         }
 734
 735         err = f2fs_submit_page_bio(&fio);
 736         if (err)
 737                 goto put_encrypted_page;
 738         f2fs_put_page(fio.encrypted_page, 0);
 739         f2fs_put_page(page, 1);
 740         return 0;
 741 put_encrypted_page:
 742         f2fs_put_page(fio.encrypted_page, 1);
 743 put_page:
 744         f2fs_put_page(page, 1);
 745         return err;
 746 }
 747
 748 /*
 749  * Move data block via META_MAPPING while keeping locked data page.
 750  * This can be used to move blocks, aka LBAs, directly on disk.
 751  */
 752 static int move_data_block(struct inode *inode, block_t bidx,
 753                                 int gc_type, unsigned int segno, int off)
 754 {
 755         struct f2fs_io_info fio = {
 756                 .sbi = F2FS_I_SB(inode),
 757                 .ino = inode->i_ino,
 758                 .type = DATA,
 759                 .temp = COLD,
 760                 .op = REQ_OP_READ,
 761                 .op_flags = 0,
 762                 .encrypted_page = NULL,
 763                 .in_list = false,
 764                 .retry = false,
 765         };
 766         struct dnode_of_data dn;
 767         struct f2fs_summary sum;
 768         struct node_info ni;
 769         struct page *page, *mpage;
 770         block_t newaddr;
 771         int err = 0;
 772         bool lfs_mode = f2fs_lfs_mode(fio.sbi);
 773
 774         /* do not read out */
 775         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
 776         if (!page)
 777                 return -ENOMEM;
 778
 779         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 780                 err = -ENOENT;
 781                 goto out;
 782         }
 783
 784         if (f2fs_is_atomic_file(inode)) {
 785                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 786                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 787                 err = -EAGAIN;
 788                 goto out;
 789         }
 790
 791         if (f2fs_is_pinned_file(inode)) {
 792                 f2fs_pin_file_control(inode, true);
 793                 err = -EAGAIN;
 794                 goto out;
 795         }
 796
 797         set_new_dnode(&dn, inode, NULL, NULL, 0);
 798         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 799         if (err)
 800                 goto out;
 801
 802         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 803                 ClearPageUptodate(page);
 804                 err = -ENOENT;
 805                 goto put_out;
 806         }
 807
 808         /*
 809          * don't cache encrypted data into meta inode until previous dirty
 810          * data were writebacked to avoid racing between GC and flush.
 811          */
 812         f2fs_wait_on_page_writeback(page, DATA, true, true);
 813
 814         f2fs_wait_on_block_writeback(inode, dn.data_blkaddr);
 815
 816         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 817         if (err)
 818                 goto put_out;
 819
 820         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
 821
 822         /* read page */
 823         fio.page = page;
 824         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 825
 826         if (lfs_mode)
 827                 down_write(&fio.sbi->io_order_lock);
 828
 829         mpage = f2fs_grab_cache_page(META_MAPPING(fio.sbi),
 830                                         fio.old_blkaddr, false);
 831         if (!mpage)
 832                 goto up_out;
 833
 834         fio.encrypted_page = mpage;
 835
 836         /* read source block in mpage */
 837         if (!PageUptodate(mpage)) {
 838                 err = f2fs_submit_page_bio(&fio);
 839                 if (err) {
 840                         f2fs_put_page(mpage, 1);
 841                         goto up_out;
 842                 }
 843                 lock_page(mpage);
 844                 if (unlikely(mpage->mapping != META_MAPPING(fio.sbi) ||
 845                                                 !PageUptodate(mpage))) {
 846                         err = -EIO;
 847                         f2fs_put_page(mpage, 1);
 848                         goto up_out;
 849                 }
 850         }
 851
 852         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
 853                                         &sum, CURSEG_COLD_DATA, NULL, false);
 854
 855         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 856                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
 857         if (!fio.encrypted_page) {
 858                 err = -ENOMEM;
 859                 f2fs_put_page(mpage, 1);
 860                 goto recover_block;
 861         }
 862
 863         /* write target block */
 864         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true);
 865         memcpy(page_address(fio.encrypted_page),
 866                                 page_address(mpage), PAGE_SIZE);
 867         f2fs_put_page(mpage, 1);
 868         invalidate_mapping_pages(META_MAPPING(fio.sbi),
 869                                 fio.old_blkaddr, fio.old_blkaddr);
 870
 871         set_page_dirty(fio.encrypted_page);
 872         if (clear_page_dirty_for_io(fio.encrypted_page))
 873                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
 874
 875         set_page_writeback(fio.encrypted_page);
 876         ClearPageError(page);
 877
 878         /* allocate block address */
 879         f2fs_wait_on_page_writeback(dn.node_page, NODE, true, true);
 880
 881         fio.op = REQ_OP_WRITE;
 882         fio.op_flags = REQ_SYNC;
 883         fio.new_blkaddr = newaddr;
 884         f2fs_submit_page_write(&fio);
 885         if (fio.retry) {
 886                 err = -EAGAIN;
 887                 if (PageWriteback(fio.encrypted_page))
 888                         end_page_writeback(fio.encrypted_page);
 889                 goto put_page_out;
 890         }
 891
 892         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
 893
 894         f2fs_update_data_blkaddr(&dn, newaddr);
 895         set_inode_flag(inode, FI_APPEND_WRITE);
 896         if (page->index == 0)
 897                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 898 put_page_out:
 899         f2fs_put_page(fio.encrypted_page, 1);
 900 recover_block:
 901         if (err)
 902                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
 903                                                                 true, true);
 904 up_out:
 905         if (lfs_mode)
 906                 up_write(&fio.sbi->io_order_lock);
 907 put_out:
 908         f2fs_put_dnode(&dn);
 909 out:
 910         f2fs_put_page(page, 1);
 911         return err;
 912 }
 913
 914 static int move_data_page(struct inode *inode, block_t bidx, int gc_type,
 915                                                         unsigned int segno, int off)
 916 {
 917         struct page *page;
 918         int err = 0;
 919
 920         page = f2fs_get_lock_data_page(inode, bidx, true);
 921         if (IS_ERR(page))
 922                 return PTR_ERR(page);
 923
 924         if (!check_valid_map(F2FS_I_SB(inode), segno, off)) {
 925                 err = -ENOENT;
 926                 goto out;
 927         }
 928
 929         if (f2fs_is_atomic_file(inode)) {
 930                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 931                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 932                 err = -EAGAIN;
 933                 goto out;
 934         }
 935         if (f2fs_is_pinned_file(inode)) {
 936                 if (gc_type == FG_GC)
 937                         f2fs_pin_file_control(inode, true);
 938                 err = -EAGAIN;
 939                 goto out;
 940         }
 941
 942         if (gc_type == BG_GC) {
 943                 if (PageWriteback(page)) {
 944                         err = -EAGAIN;
 945                         goto out;
 946                 }
 947                 set_page_dirty(page);
 948                 set_cold_data(page);
 949         } else {
 950                 struct f2fs_io_info fio = {
 951                         .sbi = F2FS_I_SB(inode),
 952                         .ino = inode->i_ino,
 953                         .type = DATA,
 954                         .temp = COLD,
 955                         .op = REQ_OP_WRITE,
 956                         .op_flags = REQ_SYNC,
 957                         .old_blkaddr = NULL_ADDR,
 958                         .page = page,
 959                         .encrypted_page = NULL,
 960                         .need_lock = LOCK_REQ,
 961                         .io_type = FS_GC_DATA_IO,
 962                 };
 963                 bool is_dirty = PageDirty(page);
 964
 965 retry:
 966                 f2fs_wait_on_page_writeback(page, DATA, true, true);
 967
 968                 set_page_dirty(page);
 969                 if (clear_page_dirty_for_io(page)) {
 970                         inode_dec_dirty_pages(inode);
 971                         f2fs_remove_dirty_inode(inode);
 972                 }
 973
 974                 set_cold_data(page);
 975
 976                 err = f2fs_do_write_data_page(&fio);
 977                 if (err) {
 978                         clear_cold_data(page);
 979                         if (err == -ENOMEM) {
 980                                 congestion_wait(BLK_RW_ASYNC,
 981                                                 DEFAULT_IO_TIMEOUT);
 982                                 goto retry;
 983                         }
 984                         if (is_dirty)
 985                                 set_page_dirty(page);
 986                 }
 987         }
 988 out:
 989         f2fs_put_page(page, 1);
 990         return err;
 991 }
 992
 993 /*
 994  * This function tries to get parent node of victim data block, and identifies
 995  * data block validity. If the block is valid, copy that with cold status and
 996  * modify parent node.
 997  * If the parent node is not valid or the data block address is different,
 998  * the victim data block is ignored.
 999  */
1000 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1001                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
1002 {
1003         struct super_block *sb = sbi->sb;
1004         struct f2fs_summary *entry;
1005         block_t start_addr;
1006         int off;
1007         int phase = 0;
1008         int submitted = 0;
1009
1010         start_addr = START_BLOCK(sbi, segno);
1011
1012 next_step:
1013         entry = sum;
1014
1015         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
1016                 struct page *data_page;
1017                 struct inode *inode;
1018                 struct node_info dni; /* dnode info for the data */
1019                 unsigned int ofs_in_node, nofs;
1020                 block_t start_bidx;
1021                 nid_t nid = le32_to_cpu(entry->nid);
1022
1023                 /*
1024                  * stop BG_GC if there is not enough free sections.
1025                  * Or, stop GC if the segment becomes fully valid caused by
1026                  * race condition along with SSR block allocation.
1027                  */
1028                 if ((gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) ||
1029                                 get_valid_blocks(sbi, segno, true) ==
1030                                                         BLKS_PER_SEC(sbi))
1031                         return submitted;
1032
1033                 if (check_valid_map(sbi, segno, off) == 0)
1034                         continue;
1035
1036                 if (phase == 0) {
1037                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
1038                                                         META_NAT, true);
1039                         continue;
1040                 }
1041
1042                 if (phase == 1) {
1043                         f2fs_ra_node_page(sbi, nid);
1044                         continue;
1045                 }
1046
1047                 /* Get an inode by ino with checking validity */
1048                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
1049                         continue;
1050
1051                 if (phase == 2) {
1052                         f2fs_ra_node_page(sbi, dni.ino);
1053                         continue;
1054                 }
1055
1056                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
1057
1058                 if (phase == 3) {
1059                         inode = f2fs_iget(sb, dni.ino);
1060                         if (IS_ERR(inode) || is_bad_inode(inode)) {
1061                                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1062                                 continue;
1063                         }
1064
1065                         if (!down_write_trylock(
1066                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
1067                                 iput(inode);
1068                                 sbi->skipped_gc_rwsem++;
1069                                 continue;
1070                         }
1071
1072                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
1073                                                                 ofs_in_node;
1074
1075                         if (f2fs_post_read_required(inode)) {
1076                                 int err = ra_data_block(inode, start_bidx);
1077
1078                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1079                                 if (err) {
1080                                         iput(inode);
1081                                         continue;
1082                                 }
1083                                 add_gc_inode(gc_list, inode);
1084                                 continue;
1085                         }
1086
1087                         data_page = f2fs_get_read_data_page(inode,
1088                                                 start_bidx, REQ_RAHEAD, true);
1089                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
1090                         if (IS_ERR(data_page)) {
1091                                 iput(inode);
1092                                 continue;
1093                         }
1094
1095                         f2fs_put_page(data_page, 0);
1096                         add_gc_inode(gc_list, inode);
1097                         continue;
1098                 }
1099
1100                 /* phase 4 */
1101                 inode = find_gc_inode(gc_list, dni.ino);
1102                 if (inode) {
1103                         struct f2fs_inode_info *fi = F2FS_I(inode);
1104                         bool locked = false;
1105                         int err;
1106
1107                         if (S_ISREG(inode->i_mode)) {
1108                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1109                                         continue;
1110                                 if (!down_write_trylock(
1111                                                 &fi->i_gc_rwsem[WRITE])) {
1112                                         sbi->skipped_gc_rwsem++;
1113                                         up_write(&fi->i_gc_rwsem[READ]);
1114                                         continue;
1115                                 }
1116                                 locked = true;
1117
1118                                 /* wait for all inflight aio data */
1119                                 inode_dio_wait(inode);
1120                         }
1121
1122                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1123                                                                 + ofs_in_node;
1124                         if (f2fs_post_read_required(inode))
1125                                 err = move_data_block(inode, start_bidx,
1126                                                         gc_type, segno, off);
1127                         else
1128                                 err = move_data_page(inode, start_bidx, gc_type,
1129                                                                 segno, off);
1130
1131                         if (!err && (gc_type == FG_GC ||
1132                                         f2fs_post_read_required(inode)))
1133                                 submitted++;
1134
1135                         if (locked) {
1136                                 up_write(&fi->i_gc_rwsem[WRITE]);
1137                                 up_write(&fi->i_gc_rwsem[READ]);
1138                         }
1139
1140                         stat_inc_data_blk_count(sbi, 1, gc_type);
1141                 }
1142         }
1143
1144         if (++phase < 5)
1145                 goto next_step;
1146
1147         return submitted;
1148 }
1149
1150 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1151                         int gc_type)
1152 {
1153         struct sit_info *sit_i = SIT_I(sbi);
1154         int ret;
1155
1156         down_write(&sit_i->sentry_lock);
1157         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1158                                               NO_CHECK_TYPE, LFS);
1159         up_write(&sit_i->sentry_lock);
1160         return ret;
1161 }
1162
1163 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1164                                 unsigned int start_segno,
1165                                 struct gc_inode_list *gc_list, int gc_type)
1166 {
1167         struct page *sum_page;
1168         struct f2fs_summary_block *sum;
1169         struct blk_plug plug;
1170         unsigned int segno = start_segno;
1171         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1172         int seg_freed = 0, migrated = 0;
1173         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1174                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1175         int submitted = 0;
1176
1177         if (__is_large_section(sbi))
1178                 end_segno = rounddown(end_segno, sbi->segs_per_sec);
1179
1180         /* readahead multi ssa blocks those have contiguous address */
1181         if (__is_large_section(sbi))
1182                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1183                                         end_segno - segno, META_SSA, true);
1184
1185         /* reference all summary page */
1186         while (segno < end_segno) {
1187                 sum_page = f2fs_get_sum_page(sbi, segno++);
1188                 if (IS_ERR(sum_page)) {
1189                         int err = PTR_ERR(sum_page);
1190
1191                         end_segno = segno - 1;
1192                         for (segno = start_segno; segno < end_segno; segno++) {
1193                                 sum_page = find_get_page(META_MAPPING(sbi),
1194                                                 GET_SUM_BLOCK(sbi, segno));
1195                                 f2fs_put_page(sum_page, 0);
1196                                 f2fs_put_page(sum_page, 0);
1197                         }
1198                         return err;
1199                 }
1200                 unlock_page(sum_page);
1201         }
1202
1203         blk_start_plug(&plug);
1204
1205         for (segno = start_segno; segno < end_segno; segno++) {
1206
1207                 /* find segment summary of victim */
1208                 sum_page = find_get_page(META_MAPPING(sbi),
1209                                         GET_SUM_BLOCK(sbi, segno));
1210                 f2fs_put_page(sum_page, 0);
1211
1212                 if (get_valid_blocks(sbi, segno, false) == 0)
1213                         goto freed;
1214                 if (gc_type == BG_GC && __is_large_section(sbi) &&
1215                                 migrated >= sbi->migration_granularity)
1216                         goto skip;
1217                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1218                         goto skip;
1219
1220                 sum = page_address(sum_page);
1221                 if (type != GET_SUM_TYPE((&sum->footer))) {
1222                         f2fs_err(sbi, "Inconsistent segment (%u) type [%d, %d] in SSA and SIT",
1223                                  segno, type, GET_SUM_TYPE((&sum->footer)));
1224                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1225                         f2fs_stop_checkpoint(sbi, false);
1226                         goto skip;
1227                 }
1228
1229                 /*
1230                  * this is to avoid deadlock:
1231                  * - lock_page(sum_page)         - f2fs_replace_block
1232                  *  - check_valid_map()            - down_write(sentry_lock)
1233                  *   - down_read(sentry_lock)     - change_curseg()
1234                  *                                  - lock_page(sum_page)
1235                  */
1236                 if (type == SUM_TYPE_NODE)
1237                         submitted += gc_node_segment(sbi, sum->entries, segno,
1238                                                                 gc_type);
1239                 else
1240                         submitted += gc_data_segment(sbi, sum->entries, gc_list,
1241                                                         segno, gc_type);
1242
1243                 stat_inc_seg_count(sbi, type, gc_type);
1244                 migrated++;
1245
1246 freed:
1247                 if (gc_type == FG_GC &&
1248                                 get_valid_blocks(sbi, segno, false) == 0)
1249                         seg_freed++;
1250
1251                 if (__is_large_section(sbi) && segno + 1 < end_segno)
1252                         sbi->next_victim_seg[gc_type] = segno + 1;
1253 skip:
1254                 f2fs_put_page(sum_page, 0);
1255         }
1256
1257         if (submitted)
1258                 f2fs_submit_merged_write(sbi,
1259                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1260
1261         blk_finish_plug(&plug);
1262
1263         stat_inc_call_count(sbi->stat_info);
1264
1265         return seg_freed;
1266 }
1267
1268 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1269                         bool background, unsigned int segno)
1270 {
1271         int gc_type = sync ? FG_GC : BG_GC;
1272         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1273         int ret = 0;
1274         struct cp_control cpc;
1275         unsigned int init_segno = segno;
1276         struct gc_inode_list gc_list = {
1277                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1278                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1279         };
1280         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1281         unsigned long long first_skipped;
1282         unsigned int skipped_round = 0, round = 0;
1283
1284         trace_f2fs_gc_begin(sbi->sb, sync, background,
1285                                 get_pages(sbi, F2FS_DIRTY_NODES),
1286                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1287                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1288                                 free_sections(sbi),
1289                                 free_segments(sbi),
1290                                 reserved_segments(sbi),
1291                                 prefree_segments(sbi));
1292
1293         cpc.reason = __get_cp_reason(sbi);
1294         sbi->skipped_gc_rwsem = 0;
1295         first_skipped = last_skipped;
1296 gc_more:
1297         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1298                 ret = -EINVAL;
1299                 goto stop;
1300         }
1301         if (unlikely(f2fs_cp_error(sbi))) {
1302                 ret = -EIO;
1303                 goto stop;
1304         }
1305
1306         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1307                 /*
1308                  * For example, if there are many prefree_segments below given
1309                  * threshold, we can make them free by checkpoint. Then, we
1310                  * secure free segments which doesn't need fggc any more.
1311                  */
1312                 if (prefree_segments(sbi) &&
1313                                 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) {
1314                         ret = f2fs_write_checkpoint(sbi, &cpc);
1315                         if (ret)
1316                                 goto stop;
1317                 }
1318                 if (has_not_enough_free_secs(sbi, 0, 0))
1319                         gc_type = FG_GC;
1320         }
1321
1322         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1323         if (gc_type == BG_GC && !background) {
1324                 ret = -EINVAL;
1325                 goto stop;
1326         }
1327         if (!__get_victim(sbi, &segno, gc_type)) {
1328                 ret = -ENODATA;
1329                 goto stop;
1330         }
1331
1332         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1333         if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1334                 sec_freed++;
1335         total_freed += seg_freed;
1336
1337         if (gc_type == FG_GC) {
1338                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1339                                                 sbi->skipped_gc_rwsem)
1340                         skipped_round++;
1341                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1342                 round++;
1343         }
1344
1345         if (gc_type == FG_GC && seg_freed)
1346                 sbi->cur_victim_sec = NULL_SEGNO;
1347
1348         if (sync)
1349                 goto stop;
1350
1351         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1352                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1353                                         skipped_round * 2 < round) {
1354                         segno = NULL_SEGNO;
1355                         goto gc_more;
1356                 }
1357
1358                 if (first_skipped < last_skipped &&
1359                                 (last_skipped - first_skipped) >
1360                                                 sbi->skipped_gc_rwsem) {
1361                         f2fs_drop_inmem_pages_all(sbi, true);
1362                         segno = NULL_SEGNO;
1363                         goto gc_more;
1364                 }
1365                 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED))
1366                         ret = f2fs_write_checkpoint(sbi, &cpc);
1367         }
1368 stop:
1369         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1370         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1371
1372         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1373                                 get_pages(sbi, F2FS_DIRTY_NODES),
1374                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1375                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1376                                 free_sections(sbi),
1377                                 free_segments(sbi),
1378                                 reserved_segments(sbi),
1379                                 prefree_segments(sbi));
1380
1381         up_write(&sbi->gc_lock);
1382
1383         put_gc_inode(&gc_list);
1384
1385         if (sync && !ret)
1386                 ret = sec_freed ? 0 : -EAGAIN;
1387         return ret;
1388 }
1389
1390 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1391 {
1392         DIRTY_I(sbi)->v_ops = &default_v_ops;
1393
1394         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1395
1396         /* give warm/cold data area from slower device */
1397         if (f2fs_is_multi_device(sbi) && !__is_large_section(sbi))
1398                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1399                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1400 }
1401
1402 static int free_segment_range(struct f2fs_sb_info *sbi, unsigned int start,
1403                                                         unsigned int end)
1404 {
1405         int type;
1406         unsigned int segno, next_inuse;
1407         int err = 0;
1408
1409         /* Move out cursegs from the target range */
1410         for (type = CURSEG_HOT_DATA; type < NR_CURSEG_TYPE; type++)
1411                 allocate_segment_for_resize(sbi, type, start, end);
1412
1413         /* do GC to move out valid blocks in the range */
1414         for (segno = start; segno <= end; segno += sbi->segs_per_sec) {
1415                 struct gc_inode_list gc_list = {
1416                         .ilist = LIST_HEAD_INIT(gc_list.ilist),
1417                         .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1418                 };
1419
1420                 down_write(&sbi->gc_lock);
1421                 do_garbage_collect(sbi, segno, &gc_list, FG_GC);
1422                 up_write(&sbi->gc_lock);
1423                 put_gc_inode(&gc_list);
1424
1425                 if (get_valid_blocks(sbi, segno, true))
1426                         return -EAGAIN;
1427         }
1428
1429         err = f2fs_sync_fs(sbi->sb, 1);
1430         if (err)
1431                 return err;
1432
1433         next_inuse = find_next_inuse(FREE_I(sbi), end + 1, start);
1434         if (next_inuse <= end) {
1435                 f2fs_err(sbi, "segno %u should be free but still inuse!",
1436                          next_inuse);
1437                 f2fs_bug_on(sbi, 1);
1438         }
1439         return err;
1440 }
1441
1442 static void update_sb_metadata(struct f2fs_sb_info *sbi, int secs)
1443 {
1444         struct f2fs_super_block *raw_sb = F2FS_RAW_SUPER(sbi);
1445         int section_count;
1446         int segment_count;
1447         int segment_count_main;
1448         long long block_count;
1449         int segs = secs * sbi->segs_per_sec;
1450
1451         down_write(&sbi->sb_lock);
1452
1453         section_count = le32_to_cpu(raw_sb->section_count);
1454         segment_count = le32_to_cpu(raw_sb->segment_count);
1455         segment_count_main = le32_to_cpu(raw_sb->segment_count_main);
1456         block_count = le64_to_cpu(raw_sb->block_count);
1457
1458         raw_sb->section_count = cpu_to_le32(section_count + secs);
1459         raw_sb->segment_count = cpu_to_le32(segment_count + segs);
1460         raw_sb->segment_count_main = cpu_to_le32(segment_count_main + segs);
1461         raw_sb->block_count = cpu_to_le64(block_count +
1462                                         (long long)segs * sbi->blocks_per_seg);
1463         if (f2fs_is_multi_device(sbi)) {
1464                 int last_dev = sbi->s_ndevs - 1;
1465                 int dev_segs =
1466                         le32_to_cpu(raw_sb->devs[last_dev].total_segments);
1467
1468                 raw_sb->devs[last_dev].total_segments =
1469                                                 cpu_to_le32(dev_segs + segs);
1470         }
1471
1472         up_write(&sbi->sb_lock);
1473 }
1474
1475 static void update_fs_metadata(struct f2fs_sb_info *sbi, int secs)
1476 {
1477         int segs = secs * sbi->segs_per_sec;
1478         long long blks = (long long)segs * sbi->blocks_per_seg;
1479         long long user_block_count =
1480                                 le64_to_cpu(F2FS_CKPT(sbi)->user_block_count);
1481
1482         SM_I(sbi)->segment_count = (int)SM_I(sbi)->segment_count + segs;
1483         MAIN_SEGS(sbi) = (int)MAIN_SEGS(sbi) + segs;
1484         FREE_I(sbi)->free_sections = (int)FREE_I(sbi)->free_sections + secs;
1485         FREE_I(sbi)->free_segments = (int)FREE_I(sbi)->free_segments + segs;
1486         F2FS_CKPT(sbi)->user_block_count = cpu_to_le64(user_block_count + blks);
1487
1488         if (f2fs_is_multi_device(sbi)) {
1489                 int last_dev = sbi->s_ndevs - 1;
1490
1491                 FDEV(last_dev).total_segments =
1492                                 (int)FDEV(last_dev).total_segments + segs;
1493                 FDEV(last_dev).end_blk =
1494                                 (long long)FDEV(last_dev).end_blk + blks;
1495 #ifdef CONFIG_BLK_DEV_ZONED
1496                 FDEV(last_dev).nr_blkz = (int)FDEV(last_dev).nr_blkz +
1497                                         (int)(blks >> sbi->log_blocks_per_blkz);
1498 #endif
1499         }
1500 }
1501
1502 int f2fs_resize_fs(struct f2fs_sb_info *sbi, __u64 block_count)
1503 {
1504         __u64 old_block_count, shrunk_blocks;
1505         unsigned int secs;
1506         int gc_mode, gc_type;
1507         int err = 0;
1508         __u32 rem;
1509
1510         old_block_count = le64_to_cpu(F2FS_RAW_SUPER(sbi)->block_count);
1511         if (block_count > old_block_count)
1512                 return -EINVAL;
1513
1514         if (f2fs_is_multi_device(sbi)) {
1515                 int last_dev = sbi->s_ndevs - 1;
1516                 __u64 last_segs = FDEV(last_dev).total_segments;
1517
1518                 if (block_count + last_segs * sbi->blocks_per_seg <=
1519                                                                 old_block_count)
1520                         return -EINVAL;
1521         }
1522
1523         /* new fs size should align to section size */
1524         div_u64_rem(block_count, BLKS_PER_SEC(sbi), &rem);
1525         if (rem)
1526                 return -EINVAL;
1527
1528         if (block_count == old_block_count)
1529                 return 0;
1530
1531         if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1532                 f2fs_err(sbi, "Should run fsck to repair first.");
1533                 return -EFSCORRUPTED;
1534         }
1535
1536         if (test_opt(sbi, DISABLE_CHECKPOINT)) {
1537                 f2fs_err(sbi, "Checkpoint should be enabled.");
1538                 return -EINVAL;
1539         }
1540
1541         freeze_bdev(sbi->sb->s_bdev);
1542
1543         shrunk_blocks = old_block_count - block_count;
1544         secs = div_u64(shrunk_blocks, BLKS_PER_SEC(sbi));
1545         spin_lock(&sbi->stat_lock);
1546         if (shrunk_blocks + valid_user_blocks(sbi) +
1547                 sbi->current_reserved_blocks + sbi->unusable_block_count +
1548                 F2FS_OPTION(sbi).root_reserved_blocks > sbi->user_block_count)
1549                 err = -ENOSPC;
1550         else
1551                 sbi->user_block_count -= shrunk_blocks;
1552         spin_unlock(&sbi->stat_lock);
1553         if (err) {
1554                 thaw_bdev(sbi->sb->s_bdev, sbi->sb);
1555                 return err;
1556         }
1557
1558         mutex_lock(&sbi->resize_mutex);
1559         set_sbi_flag(sbi, SBI_IS_RESIZEFS);
1560
1561         mutex_lock(&DIRTY_I(sbi)->seglist_lock);
1562
1563         MAIN_SECS(sbi) -= secs;
1564
1565         for (gc_mode = 0; gc_mode < MAX_GC_POLICY; gc_mode++)
1566                 if (SIT_I(sbi)->last_victim[gc_mode] >=
1567                                         MAIN_SECS(sbi) * sbi->segs_per_sec)
1568                         SIT_I(sbi)->last_victim[gc_mode] = 0;
1569
1570         for (gc_type = BG_GC; gc_type <= FG_GC; gc_type++)
1571                 if (sbi->next_victim_seg[gc_type] >=
1572                                         MAIN_SECS(sbi) * sbi->segs_per_sec)
1573                         sbi->next_victim_seg[gc_type] = NULL_SEGNO;
1574
1575         mutex_unlock(&DIRTY_I(sbi)->seglist_lock);
1576
1577         err = free_segment_range(sbi, MAIN_SECS(sbi) * sbi->segs_per_sec,
1578                         MAIN_SEGS(sbi) - 1);
1579         if (err)
1580                 goto out;
1581
1582         update_sb_metadata(sbi, -secs);
1583
1584         err = f2fs_commit_super(sbi, false);
1585         if (err) {
1586                 update_sb_metadata(sbi, secs);
1587                 goto out;
1588         }
1589
1590         mutex_lock(&sbi->cp_mutex);
1591         update_fs_metadata(sbi, -secs);
1592         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
1593         set_sbi_flag(sbi, SBI_IS_DIRTY);
1594         mutex_unlock(&sbi->cp_mutex);
1595
1596         err = f2fs_sync_fs(sbi->sb, 1);
1597         if (err) {
1598                 mutex_lock(&sbi->cp_mutex);
1599                 update_fs_metadata(sbi, secs);
1600                 mutex_unlock(&sbi->cp_mutex);
1601                 update_sb_metadata(sbi, secs);
1602                 f2fs_commit_super(sbi, false);
1603         }
1604 out:
1605         if (err) {
1606                 set_sbi_flag(sbi, SBI_NEED_FSCK);
1607                 f2fs_err(sbi, "resize_fs failed, should run fsck to repair!");
1608
1609                 MAIN_SECS(sbi) += secs;
1610                 spin_lock(&sbi->stat_lock);
1611                 sbi->user_block_count += shrunk_blocks;
1612                 spin_unlock(&sbi->stat_lock);
1613         }
1614         clear_sbi_flag(sbi, SBI_IS_RESIZEFS);
1615         mutex_unlock(&sbi->resize_mutex);
1616         thaw_bdev(sbi->sb->s_bdev, sbi->sb);
1617         return err;
1618 }