fs/f2fs/gc.c

   1 /*
   2  * fs/f2fs/gc.c
   3  *
   4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
   5  *             http://www.samsung.com/
   6  *
   7  * This program is free software; you can redistribute it and/or modify
   8  * it under the terms of the GNU General Public License version 2 as
   9  * published by the Free Software Foundation.
  10  */
  11 #include <linux/fs.h>
  12 #include <linux/module.h>
  13 #include <linux/backing-dev.h>
  14 #include <linux/init.h>
  15 #include <linux/f2fs_fs.h>
  16 #include <linux/kthread.h>
  17 #include <linux/delay.h>
  18 #include <linux/freezer.h>
  19
  20 #include "f2fs.h"
  21 #include "node.h"
  22 #include "segment.h"
  23 #include "gc.h"
  24 #include <trace/events/f2fs.h>
  25
  26 static int gc_thread_func(void *data)
  27 {
  28         struct f2fs_sb_info *sbi = data;
  29         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
  30         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  31         unsigned int wait_ms;
  32
  33         wait_ms = gc_th->min_sleep_time;
  34
  35         set_freezable();
  36         do {
  37                 wait_event_interruptible_timeout(*wq,
  38                                 kthread_should_stop() || freezing(current) ||
  39                                 gc_th->gc_wake,
  40                                 msecs_to_jiffies(wait_ms));
  41
  42                 /* give it a try one time */
  43                 if (gc_th->gc_wake)
  44                         gc_th->gc_wake = 0;
  45
  46                 if (try_to_freeze())
  47                         continue;
  48                 if (kthread_should_stop())
  49                         break;
  50
  51                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  52                         increase_sleep_time(gc_th, &wait_ms);
  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                         continue;
  63
  64                 /*
  65                  * [GC triggering condition]
  66                  * 0. GC is not conducted currently.
  67                  * 1. There are enough dirty segments.
  68                  * 2. IO subsystem is idle by checking the # of writeback pages.
  69                  * 3. IO subsystem is idle by checking the # of requests in
  70                  *    bdev's request list.
  71                  *
  72                  * Note) We have to avoid triggering GCs frequently.
  73                  * Because it is possible that some segments can be
  74                  * invalidated soon after by user update or deletion.
  75                  * So, I'd like to wait some time to collect dirty segments.
  76                  */
  77                 if (sbi->gc_mode == GC_URGENT) {
  78                         wait_ms = gc_th->urgent_sleep_time;
  79                         mutex_lock(&sbi->gc_mutex);
  80                         goto do_gc;
  81                 }
  82
  83                 if (!mutex_trylock(&sbi->gc_mutex))
  84                         goto next;
  85
  86                 if (!is_idle(sbi)) {
  87                         increase_sleep_time(gc_th, &wait_ms);
  88                         mutex_unlock(&sbi->gc_mutex);
  89                         goto next;
  90                 }
  91
  92                 if (has_enough_invalid_blocks(sbi))
  93                         decrease_sleep_time(gc_th, &wait_ms);
  94                 else
  95                         increase_sleep_time(gc_th, &wait_ms);
  96 do_gc:
  97                 stat_inc_bggc_count(sbi);
  98
  99                 /* if return value is not zero, no victim was selected */
 100                 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
 101                         wait_ms = gc_th->no_gc_sleep_time;
 102
 103                 trace_f2fs_background_gc(sbi->sb, wait_ms,
 104                                 prefree_segments(sbi), free_segments(sbi));
 105
 106                 /* balancing f2fs's metadata periodically */
 107                 f2fs_balance_fs_bg(sbi);
 108 next:
 109                 sb_end_write(sbi->sb);
 110
 111         } while (!kthread_should_stop());
 112         return 0;
 113 }
 114
 115 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi)
 116 {
 117         struct f2fs_gc_kthread *gc_th;
 118         dev_t dev = sbi->sb->s_bdev->bd_dev;
 119         int err = 0;
 120
 121         gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
 122         if (!gc_th) {
 123                 err = -ENOMEM;
 124                 goto out;
 125         }
 126
 127         gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
 128         gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
 129         gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
 130         gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
 131
 132         gc_th->gc_wake= 0;
 133
 134         sbi->gc_thread = gc_th;
 135         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 136         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 137                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 138         if (IS_ERR(gc_th->f2fs_gc_task)) {
 139                 err = PTR_ERR(gc_th->f2fs_gc_task);
 140                 kfree(gc_th);
 141                 sbi->gc_thread = NULL;
 142         }
 143 out:
 144         return err;
 145 }
 146
 147 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi)
 148 {
 149         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 150         if (!gc_th)
 151                 return;
 152         kthread_stop(gc_th->f2fs_gc_task);
 153         kfree(gc_th);
 154         sbi->gc_thread = NULL;
 155 }
 156
 157 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type)
 158 {
 159         int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
 160
 161         switch (sbi->gc_mode) {
 162         case GC_IDLE_CB:
 163                 gc_mode = GC_CB;
 164                 break;
 165         case GC_IDLE_GREEDY:
 166         case GC_URGENT:
 167                 gc_mode = GC_GREEDY;
 168                 break;
 169         }
 170         return gc_mode;
 171 }
 172
 173 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 174                         int type, struct victim_sel_policy *p)
 175 {
 176         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 177
 178         if (p->alloc_mode == SSR) {
 179                 p->gc_mode = GC_GREEDY;
 180                 p->dirty_segmap = dirty_i->dirty_segmap[type];
 181                 p->max_search = dirty_i->nr_dirty[type];
 182                 p->ofs_unit = 1;
 183         } else {
 184                 p->gc_mode = select_gc_type(sbi, gc_type);
 185                 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
 186                 p->max_search = dirty_i->nr_dirty[DIRTY];
 187                 p->ofs_unit = sbi->segs_per_sec;
 188         }
 189
 190         /* we need to check every dirty segments in the FG_GC case */
 191         if (gc_type != FG_GC &&
 192                         (sbi->gc_mode != GC_URGENT) &&
 193                         p->max_search > sbi->max_victim_search)
 194                 p->max_search = sbi->max_victim_search;
 195
 196         /* let's select beginning hot/small space first in no_heap mode*/
 197         if (test_opt(sbi, NOHEAP) &&
 198                 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
 199                 p->offset = 0;
 200         else
 201                 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
 202 }
 203
 204 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 205                                 struct victim_sel_policy *p)
 206 {
 207         /* SSR allocates in a segment unit */
 208         if (p->alloc_mode == SSR)
 209                 return sbi->blocks_per_seg;
 210         if (p->gc_mode == GC_GREEDY)
 211                 return 2 * sbi->blocks_per_seg * p->ofs_unit;
 212         else if (p->gc_mode == GC_CB)
 213                 return UINT_MAX;
 214         else /* No other gc_mode */
 215                 return 0;
 216 }
 217
 218 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 219 {
 220         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 221         unsigned int secno;
 222
 223         /*
 224          * If the gc_type is FG_GC, we can select victim segments
 225          * selected by background GC before.
 226          * Those segments guarantee they have small valid blocks.
 227          */
 228         for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
 229                 if (sec_usage_check(sbi, secno))
 230                         continue;
 231                 clear_bit(secno, dirty_i->victim_secmap);
 232                 return GET_SEG_FROM_SEC(sbi, secno);
 233         }
 234         return NULL_SEGNO;
 235 }
 236
 237 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 238 {
 239         struct sit_info *sit_i = SIT_I(sbi);
 240         unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
 241         unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
 242         unsigned long long mtime = 0;
 243         unsigned int vblocks;
 244         unsigned char age = 0;
 245         unsigned char u;
 246         unsigned int i;
 247
 248         for (i = 0; i < sbi->segs_per_sec; i++)
 249                 mtime += get_seg_entry(sbi, start + i)->mtime;
 250         vblocks = get_valid_blocks(sbi, segno, true);
 251
 252         mtime = div_u64(mtime, sbi->segs_per_sec);
 253         vblocks = div_u64(vblocks, sbi->segs_per_sec);
 254
 255         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 256
 257         /* Handle if the system time has changed by the user */
 258         if (mtime < sit_i->min_mtime)
 259                 sit_i->min_mtime = mtime;
 260         if (mtime > sit_i->max_mtime)
 261                 sit_i->max_mtime = mtime;
 262         if (sit_i->max_mtime != sit_i->min_mtime)
 263                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 264                                 sit_i->max_mtime - sit_i->min_mtime);
 265
 266         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 267 }
 268
 269 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
 270                         unsigned int segno, struct victim_sel_policy *p)
 271 {
 272         if (p->alloc_mode == SSR)
 273                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 274
 275         /* alloc_mode == LFS */
 276         if (p->gc_mode == GC_GREEDY)
 277                 return get_valid_blocks(sbi, segno, true);
 278         else
 279                 return get_cb_cost(sbi, segno);
 280 }
 281
 282 static unsigned int count_bits(const unsigned long *addr,
 283                                 unsigned int offset, unsigned int len)
 284 {
 285         unsigned int end = offset + len, sum = 0;
 286
 287         while (offset < end) {
 288                 if (test_bit(offset++, addr))
 289                         ++sum;
 290         }
 291         return sum;
 292 }
 293
 294 /*
 295  * This function is called from two paths.
 296  * One is garbage collection and the other is SSR segment selection.
 297  * When it is called during GC, it just gets a victim segment
 298  * and it does not remove it from dirty seglist.
 299  * When it is called from SSR segment selection, it finds a segment
 300  * which has minimum valid blocks and removes it from dirty seglist.
 301  */
 302 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 303                 unsigned int *result, int gc_type, int type, char alloc_mode)
 304 {
 305         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 306         struct sit_info *sm = SIT_I(sbi);
 307         struct victim_sel_policy p;
 308         unsigned int secno, last_victim;
 309         unsigned int last_segment = MAIN_SEGS(sbi);
 310         unsigned int nsearched = 0;
 311
 312         mutex_lock(&dirty_i->seglist_lock);
 313
 314         p.alloc_mode = alloc_mode;
 315         select_policy(sbi, gc_type, type, &p);
 316
 317         p.min_segno = NULL_SEGNO;
 318         p.min_cost = get_max_cost(sbi, &p);
 319
 320         if (*result != NULL_SEGNO) {
 321                 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) &&
 322                         get_valid_blocks(sbi, *result, false) &&
 323                         !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 324                         p.min_segno = *result;
 325                 goto out;
 326         }
 327
 328         if (p.max_search == 0)
 329                 goto out;
 330
 331         last_victim = sm->last_victim[p.gc_mode];
 332         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 333                 p.min_segno = check_bg_victims(sbi);
 334                 if (p.min_segno != NULL_SEGNO)
 335                         goto got_it;
 336         }
 337
 338         while (1) {
 339                 unsigned long cost;
 340                 unsigned int segno;
 341
 342                 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
 343                 if (segno >= last_segment) {
 344                         if (sm->last_victim[p.gc_mode]) {
 345                                 last_segment =
 346                                         sm->last_victim[p.gc_mode];
 347                                 sm->last_victim[p.gc_mode] = 0;
 348                                 p.offset = 0;
 349                                 continue;
 350                         }
 351                         break;
 352                 }
 353
 354                 p.offset = segno + p.ofs_unit;
 355                 if (p.ofs_unit > 1) {
 356                         p.offset -= segno % p.ofs_unit;
 357                         nsearched += count_bits(p.dirty_segmap,
 358                                                 p.offset - p.ofs_unit,
 359                                                 p.ofs_unit);
 360                 } else {
 361                         nsearched++;
 362                 }
 363
 364                 secno = GET_SEC_FROM_SEG(sbi, segno);
 365
 366                 if (sec_usage_check(sbi, secno))
 367                         goto next;
 368                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 369                         goto next;
 370
 371                 cost = get_gc_cost(sbi, segno, &p);
 372
 373                 if (p.min_cost > cost) {
 374                         p.min_segno = segno;
 375                         p.min_cost = cost;
 376                 }
 377 next:
 378                 if (nsearched >= p.max_search) {
 379                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 380                                 sm->last_victim[p.gc_mode] = last_victim + 1;
 381                         else
 382                                 sm->last_victim[p.gc_mode] = segno + 1;
 383                         sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
 384                         break;
 385                 }
 386         }
 387         if (p.min_segno != NULL_SEGNO) {
 388 got_it:
 389                 if (p.alloc_mode == LFS) {
 390                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 391                         if (gc_type == FG_GC)
 392                                 sbi->cur_victim_sec = secno;
 393                         else
 394                                 set_bit(secno, dirty_i->victim_secmap);
 395                 }
 396                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 397
 398                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 399                                 sbi->cur_victim_sec,
 400                                 prefree_segments(sbi), free_segments(sbi));
 401         }
 402 out:
 403         mutex_unlock(&dirty_i->seglist_lock);
 404
 405         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 406 }
 407
 408 static const struct victim_selection default_v_ops = {
 409         .get_victim = get_victim_by_default,
 410 };
 411
 412 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 413 {
 414         struct inode_entry *ie;
 415
 416         ie = radix_tree_lookup(&gc_list->iroot, ino);
 417         if (ie)
 418                 return ie->inode;
 419         return NULL;
 420 }
 421
 422 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 423 {
 424         struct inode_entry *new_ie;
 425
 426         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 427                 iput(inode);
 428                 return;
 429         }
 430         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 431         new_ie->inode = inode;
 432
 433         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 434         list_add_tail(&new_ie->list, &gc_list->ilist);
 435 }
 436
 437 static void put_gc_inode(struct gc_inode_list *gc_list)
 438 {
 439         struct inode_entry *ie, *next_ie;
 440         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 441                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 442                 iput(ie->inode);
 443                 list_del(&ie->list);
 444                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 445         }
 446 }
 447
 448 static int check_valid_map(struct f2fs_sb_info *sbi,
 449                                 unsigned int segno, int offset)
 450 {
 451         struct sit_info *sit_i = SIT_I(sbi);
 452         struct seg_entry *sentry;
 453         int ret;
 454
 455         down_read(&sit_i->sentry_lock);
 456         sentry = get_seg_entry(sbi, segno);
 457         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 458         up_read(&sit_i->sentry_lock);
 459         return ret;
 460 }
 461
 462 /*
 463  * This function compares node address got in summary with that in NAT.
 464  * On validity, copy that node with cold status, otherwise (invalid node)
 465  * ignore that.
 466  */
 467 static void gc_node_segment(struct f2fs_sb_info *sbi,
 468                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 469 {
 470         struct f2fs_summary *entry;
 471         block_t start_addr;
 472         int off;
 473         int phase = 0;
 474         bool fggc = (gc_type == FG_GC);
 475
 476         start_addr = START_BLOCK(sbi, segno);
 477
 478 next_step:
 479         entry = sum;
 480
 481         if (fggc && phase == 2)
 482                 atomic_inc(&sbi->wb_sync_req[NODE]);
 483
 484         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 485                 nid_t nid = le32_to_cpu(entry->nid);
 486                 struct page *node_page;
 487                 struct node_info ni;
 488
 489                 /* stop BG_GC if there is not enough free sections. */
 490                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 491                         return;
 492
 493                 if (check_valid_map(sbi, segno, off) == 0)
 494                         continue;
 495
 496                 if (phase == 0) {
 497                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 498                                                         META_NAT, true);
 499                         continue;
 500                 }
 501
 502                 if (phase == 1) {
 503                         f2fs_ra_node_page(sbi, nid);
 504                         continue;
 505                 }
 506
 507                 /* phase == 2 */
 508                 node_page = f2fs_get_node_page(sbi, nid);
 509                 if (IS_ERR(node_page))
 510                         continue;
 511
 512                 /* block may become invalid during f2fs_get_node_page */
 513                 if (check_valid_map(sbi, segno, off) == 0) {
 514                         f2fs_put_page(node_page, 1);
 515                         continue;
 516                 }
 517
 518                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 519                         f2fs_put_page(node_page, 1);
 520                         continue;
 521                 }
 522
 523                 if (ni.blk_addr != start_addr + off) {
 524                         f2fs_put_page(node_page, 1);
 525                         continue;
 526                 }
 527
 528                 f2fs_move_node_page(node_page, gc_type);
 529                 stat_inc_node_blk_count(sbi, 1, gc_type);
 530         }
 531
 532         if (++phase < 3)
 533                 goto next_step;
 534
 535         if (fggc)
 536                 atomic_dec(&sbi->wb_sync_req[NODE]);
 537 }
 538
 539 /*
 540  * Calculate start block index indicating the given node offset.
 541  * Be careful, caller should give this node offset only indicating direct node
 542  * blocks. If any node offsets, which point the other types of node blocks such
 543  * as indirect or double indirect node blocks, are given, it must be a caller's
 544  * bug.
 545  */
 546 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 547 {
 548         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 549         unsigned int bidx;
 550
 551         if (node_ofs == 0)
 552                 return 0;
 553
 554         if (node_ofs <= 2) {
 555                 bidx = node_ofs - 1;
 556         } else if (node_ofs <= indirect_blks) {
 557                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 558                 bidx = node_ofs - 2 - dec;
 559         } else {
 560                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 561                 bidx = node_ofs - 5 - dec;
 562         }
 563         return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
 564 }
 565
 566 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 567                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 568 {
 569         struct page *node_page;
 570         nid_t nid;
 571         unsigned int ofs_in_node;
 572         block_t source_blkaddr;
 573
 574         nid = le32_to_cpu(sum->nid);
 575         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 576
 577         node_page = f2fs_get_node_page(sbi, nid);
 578         if (IS_ERR(node_page))
 579                 return false;
 580
 581         if (f2fs_get_node_info(sbi, nid, dni)) {
 582                 f2fs_put_page(node_page, 1);
 583                 return false;
 584         }
 585
 586         if (sum->version != dni->version) {
 587                 f2fs_msg(sbi->sb, KERN_WARNING,
 588                                 "%s: valid data with mismatched node version.",
 589                                 __func__);
 590                 set_sbi_flag(sbi, SBI_NEED_FSCK);
 591         }
 592
 593         *nofs = ofs_of_node(node_page);
 594         source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
 595         f2fs_put_page(node_page, 1);
 596
 597         if (source_blkaddr != blkaddr)
 598                 return false;
 599         return true;
 600 }
 601
 602 static int ra_data_block(struct inode *inode, pgoff_t index)
 603 {
 604         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 605         struct address_space *mapping = inode->i_mapping;
 606         struct dnode_of_data dn;
 607         struct page *page;
 608         struct extent_info ei = {0, 0, 0};
 609         struct f2fs_io_info fio = {
 610                 .sbi = sbi,
 611                 .ino = inode->i_ino,
 612                 .type = DATA,
 613                 .temp = COLD,
 614                 .op = REQ_OP_READ,
 615                 .op_flags = 0,
 616                 .encrypted_page = NULL,
 617                 .in_list = false,
 618                 .retry = false,
 619         };
 620         int err;
 621
 622         page = f2fs_grab_cache_page(mapping, index, true);
 623         if (!page)
 624                 return -ENOMEM;
 625
 626         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 627                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 628                 goto got_it;
 629         }
 630
 631         set_new_dnode(&dn, inode, NULL, NULL, 0);
 632         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
 633         if (err)
 634                 goto put_page;
 635         f2fs_put_dnode(&dn);
 636
 637         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 638                                                 DATA_GENERIC))) {
 639                 err = -EFSCORRUPTED;
 640                 goto put_page;
 641         }
 642 got_it:
 643         /* read page */
 644         fio.page = page;
 645         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 646
 647         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
 648                                         dn.data_blkaddr,
 649                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
 650         if (!fio.encrypted_page) {
 651                 err = -ENOMEM;
 652                 goto put_page;
 653         }
 654
 655         err = f2fs_submit_page_bio(&fio);
 656         if (err)
 657                 goto put_encrypted_page;
 658         f2fs_put_page(fio.encrypted_page, 0);
 659         f2fs_put_page(page, 1);
 660         return 0;
 661 put_encrypted_page:
 662         f2fs_put_page(fio.encrypted_page, 1);
 663 put_page:
 664         f2fs_put_page(page, 1);
 665         return err;
 666 }
 667
 668 /*
 669  * Move data block via META_MAPPING while keeping locked data page.
 670  * This can be used to move blocks, aka LBAs, directly on disk.
 671  */
 672 static void move_data_block(struct inode *inode, block_t bidx,
 673                                 int gc_type, unsigned int segno, int off)
 674 {
 675         struct f2fs_io_info fio = {
 676                 .sbi = F2FS_I_SB(inode),
 677                 .ino = inode->i_ino,
 678                 .type = DATA,
 679                 .temp = COLD,
 680                 .op = REQ_OP_READ,
 681                 .op_flags = 0,
 682                 .encrypted_page = NULL,
 683                 .in_list = false,
 684                 .retry = false,
 685         };
 686         struct dnode_of_data dn;
 687         struct f2fs_summary sum;
 688         struct node_info ni;
 689         struct page *page, *mpage;
 690         block_t newaddr;
 691         int err;
 692         bool lfs_mode = test_opt(fio.sbi, LFS);
 693
 694         /* do not read out */
 695         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
 696         if (!page)
 697                 return;
 698
 699         if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 700                 goto out;
 701
 702         if (f2fs_is_atomic_file(inode)) {
 703                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 704                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 705                 goto out;
 706         }
 707
 708         if (f2fs_is_pinned_file(inode)) {
 709                 f2fs_pin_file_control(inode, true);
 710                 goto out;
 711         }
 712
 713         set_new_dnode(&dn, inode, NULL, NULL, 0);
 714         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 715         if (err)
 716                 goto out;
 717
 718         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 719                 ClearPageUptodate(page);
 720                 goto put_out;
 721         }
 722
 723         /*
 724          * don't cache encrypted data into meta inode until previous dirty
 725          * data were writebacked to avoid racing between GC and flush.
 726          */
 727         f2fs_wait_on_page_writeback(page, DATA, true);
 728
 729         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 730         if (err)
 731                 goto put_out;
 732
 733         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
 734
 735         /* read page */
 736         fio.page = page;
 737         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 738
 739         if (lfs_mode)
 740                 down_write(&fio.sbi->io_order_lock);
 741
 742         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
 743                                         &sum, CURSEG_COLD_DATA, NULL, false);
 744
 745         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 746                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
 747         if (!fio.encrypted_page) {
 748                 err = -ENOMEM;
 749                 goto recover_block;
 750         }
 751
 752         mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 753                                         fio.old_blkaddr, FGP_LOCK, GFP_NOFS);
 754         if (mpage) {
 755                 bool updated = false;
 756
 757                 if (PageUptodate(mpage)) {
 758                         memcpy(page_address(fio.encrypted_page),
 759                                         page_address(mpage), PAGE_SIZE);
 760                         updated = true;
 761                 }
 762                 f2fs_put_page(mpage, 1);
 763                 invalidate_mapping_pages(META_MAPPING(fio.sbi),
 764                                         fio.old_blkaddr, fio.old_blkaddr);
 765                 if (updated)
 766                         goto write_page;
 767         }
 768
 769         err = f2fs_submit_page_bio(&fio);
 770         if (err)
 771                 goto put_page_out;
 772
 773         /* write page */
 774         lock_page(fio.encrypted_page);
 775
 776         if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
 777                 err = -EIO;
 778                 goto put_page_out;
 779         }
 780         if (unlikely(!PageUptodate(fio.encrypted_page))) {
 781                 err = -EIO;
 782                 goto put_page_out;
 783         }
 784
 785 write_page:
 786         set_page_dirty(fio.encrypted_page);
 787         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
 788         if (clear_page_dirty_for_io(fio.encrypted_page))
 789                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
 790
 791         set_page_writeback(fio.encrypted_page);
 792         ClearPageError(page);
 793
 794         /* allocate block address */
 795         f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
 796
 797         fio.op = REQ_OP_WRITE;
 798         fio.op_flags = REQ_SYNC;
 799         fio.new_blkaddr = newaddr;
 800         f2fs_submit_page_write(&fio);
 801         if (fio.retry) {
 802                 if (PageWriteback(fio.encrypted_page))
 803                         end_page_writeback(fio.encrypted_page);
 804                 goto put_page_out;
 805         }
 806
 807         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
 808
 809         f2fs_update_data_blkaddr(&dn, newaddr);
 810         set_inode_flag(inode, FI_APPEND_WRITE);
 811         if (page->index == 0)
 812                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 813 put_page_out:
 814         f2fs_put_page(fio.encrypted_page, 1);
 815 recover_block:
 816         if (lfs_mode)
 817                 up_write(&fio.sbi->io_order_lock);
 818         if (err)
 819                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
 820                                                                 true, true);
 821 put_out:
 822         f2fs_put_dnode(&dn);
 823 out:
 824         f2fs_put_page(page, 1);
 825 }
 826
 827 static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
 828                                                         unsigned int segno, int off)
 829 {
 830         struct page *page;
 831
 832         page = f2fs_get_lock_data_page(inode, bidx, true);
 833         if (IS_ERR(page))
 834                 return;
 835
 836         if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 837                 goto out;
 838
 839         if (f2fs_is_atomic_file(inode)) {
 840                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 841                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 842                 goto out;
 843         }
 844         if (f2fs_is_pinned_file(inode)) {
 845                 if (gc_type == FG_GC)
 846                         f2fs_pin_file_control(inode, true);
 847                 goto out;
 848         }
 849
 850         if (gc_type == BG_GC) {
 851                 if (PageWriteback(page))
 852                         goto out;
 853                 set_page_dirty(page);
 854                 set_cold_data(page);
 855         } else {
 856                 struct f2fs_io_info fio = {
 857                         .sbi = F2FS_I_SB(inode),
 858                         .ino = inode->i_ino,
 859                         .type = DATA,
 860                         .temp = COLD,
 861                         .op = REQ_OP_WRITE,
 862                         .op_flags = REQ_SYNC,
 863                         .old_blkaddr = NULL_ADDR,
 864                         .page = page,
 865                         .encrypted_page = NULL,
 866                         .need_lock = LOCK_REQ,
 867                         .io_type = FS_GC_DATA_IO,
 868                 };
 869                 bool is_dirty = PageDirty(page);
 870                 int err;
 871
 872 retry:
 873                 set_page_dirty(page);
 874                 f2fs_wait_on_page_writeback(page, DATA, true);
 875                 if (clear_page_dirty_for_io(page)) {
 876                         inode_dec_dirty_pages(inode);
 877                         f2fs_remove_dirty_inode(inode);
 878                 }
 879
 880                 set_cold_data(page);
 881
 882                 err = f2fs_do_write_data_page(&fio);
 883                 if (err) {
 884                         clear_cold_data(page);
 885                         if (err == -ENOMEM) {
 886                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 887                                 goto retry;
 888                         }
 889                         if (is_dirty)
 890                                 set_page_dirty(page);
 891                 }
 892         }
 893 out:
 894         f2fs_put_page(page, 1);
 895 }
 896
 897 /*
 898  * This function tries to get parent node of victim data block, and identifies
 899  * data block validity. If the block is valid, copy that with cold status and
 900  * modify parent node.
 901  * If the parent node is not valid or the data block address is different,
 902  * the victim data block is ignored.
 903  */
 904 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 905                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
 906 {
 907         struct super_block *sb = sbi->sb;
 908         struct f2fs_summary *entry;
 909         block_t start_addr;
 910         int off;
 911         int phase = 0;
 912
 913         start_addr = START_BLOCK(sbi, segno);
 914
 915 next_step:
 916         entry = sum;
 917
 918         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 919                 struct page *data_page;
 920                 struct inode *inode;
 921                 struct node_info dni; /* dnode info for the data */
 922                 unsigned int ofs_in_node, nofs;
 923                 block_t start_bidx;
 924                 nid_t nid = le32_to_cpu(entry->nid);
 925
 926                 /* stop BG_GC if there is not enough free sections. */
 927                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 928                         return;
 929
 930                 if (check_valid_map(sbi, segno, off) == 0)
 931                         continue;
 932
 933                 if (phase == 0) {
 934                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 935                                                         META_NAT, true);
 936                         continue;
 937                 }
 938
 939                 if (phase == 1) {
 940                         f2fs_ra_node_page(sbi, nid);
 941                         continue;
 942                 }
 943
 944                 /* Get an inode by ino with checking validity */
 945                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
 946                         continue;
 947
 948                 if (phase == 2) {
 949                         f2fs_ra_node_page(sbi, dni.ino);
 950                         continue;
 951                 }
 952
 953                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
 954
 955                 if (phase == 3) {
 956                         inode = f2fs_iget(sb, dni.ino);
 957                         if (IS_ERR(inode) || is_bad_inode(inode))
 958                                 continue;
 959
 960                         if (!down_write_trylock(
 961                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
 962                                 iput(inode);
 963                                 sbi->skipped_gc_rwsem++;
 964                                 continue;
 965                         }
 966
 967                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
 968                                                                 ofs_in_node;
 969
 970                         if (f2fs_post_read_required(inode)) {
 971                                 int err = ra_data_block(inode, start_bidx);
 972
 973                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 974                                 if (err) {
 975                                         iput(inode);
 976                                         continue;
 977                                 }
 978                                 add_gc_inode(gc_list, inode);
 979                                 continue;
 980                         }
 981
 982                         data_page = f2fs_get_read_data_page(inode,
 983                                                 start_bidx, REQ_RAHEAD, true);
 984                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 985                         if (IS_ERR(data_page)) {
 986                                 iput(inode);
 987                                 continue;
 988                         }
 989
 990                         f2fs_put_page(data_page, 0);
 991                         add_gc_inode(gc_list, inode);
 992                         continue;
 993                 }
 994
 995                 /* phase 4 */
 996                 inode = find_gc_inode(gc_list, dni.ino);
 997                 if (inode) {
 998                         struct f2fs_inode_info *fi = F2FS_I(inode);
 999                         bool locked = false;
1000
1001                         if (S_ISREG(inode->i_mode)) {
1002                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ]))
1003                                         continue;
1004                                 if (!down_write_trylock(
1005                                                 &fi->i_gc_rwsem[WRITE])) {
1006                                         sbi->skipped_gc_rwsem++;
1007                                         up_write(&fi->i_gc_rwsem[READ]);
1008                                         continue;
1009                                 }
1010                                 locked = true;
1011
1012                                 /* wait for all inflight aio data */
1013                                 inode_dio_wait(inode);
1014                         }
1015
1016                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1017                                                                 + ofs_in_node;
1018                         if (f2fs_post_read_required(inode))
1019                                 move_data_block(inode, start_bidx, gc_type,
1020                                                                 segno, off);
1021                         else
1022                                 move_data_page(inode, start_bidx, gc_type,
1023                                                                 segno, off);
1024
1025                         if (locked) {
1026                                 up_write(&fi->i_gc_rwsem[WRITE]);
1027                                 up_write(&fi->i_gc_rwsem[READ]);
1028                         }
1029
1030                         stat_inc_data_blk_count(sbi, 1, gc_type);
1031                 }
1032         }
1033
1034         if (++phase < 5)
1035                 goto next_step;
1036 }
1037
1038 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1039                         int gc_type)
1040 {
1041         struct sit_info *sit_i = SIT_I(sbi);
1042         int ret;
1043
1044         down_write(&sit_i->sentry_lock);
1045         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1046                                               NO_CHECK_TYPE, LFS);
1047         up_write(&sit_i->sentry_lock);
1048         return ret;
1049 }
1050
1051 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1052                                 unsigned int start_segno,
1053                                 struct gc_inode_list *gc_list, int gc_type)
1054 {
1055         struct page *sum_page;
1056         struct f2fs_summary_block *sum;
1057         struct blk_plug plug;
1058         unsigned int segno = start_segno;
1059         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1060         int seg_freed = 0;
1061         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1062                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1063
1064         /* readahead multi ssa blocks those have contiguous address */
1065         if (sbi->segs_per_sec > 1)
1066                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1067                                         sbi->segs_per_sec, META_SSA, true);
1068
1069         /* reference all summary page */
1070         while (segno < end_segno) {
1071                 sum_page = f2fs_get_sum_page(sbi, segno++);
1072                 unlock_page(sum_page);
1073         }
1074
1075         blk_start_plug(&plug);
1076
1077         for (segno = start_segno; segno < end_segno; segno++) {
1078
1079                 /* find segment summary of victim */
1080                 sum_page = find_get_page(META_MAPPING(sbi),
1081                                         GET_SUM_BLOCK(sbi, segno));
1082                 f2fs_put_page(sum_page, 0);
1083
1084                 if (get_valid_blocks(sbi, segno, false) == 0 ||
1085                                 !PageUptodate(sum_page) ||
1086                                 unlikely(f2fs_cp_error(sbi)))
1087                         goto next;
1088
1089                 sum = page_address(sum_page);
1090                 if (type != GET_SUM_TYPE((&sum->footer))) {
1091                         f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) "
1092                                 "type [%d, %d] in SSA and SIT",
1093                                 segno, type, GET_SUM_TYPE((&sum->footer)));
1094                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1095                         goto next;
1096                 }
1097
1098                 /*
1099                  * this is to avoid deadlock:
1100                  * - lock_page(sum_page)         - f2fs_replace_block
1101                  *  - check_valid_map()            - down_write(sentry_lock)
1102                  *   - down_read(sentry_lock)     - change_curseg()
1103                  *                                  - lock_page(sum_page)
1104                  */
1105                 if (type == SUM_TYPE_NODE)
1106                         gc_node_segment(sbi, sum->entries, segno, gc_type);
1107                 else
1108                         gc_data_segment(sbi, sum->entries, gc_list, segno,
1109                                                                 gc_type);
1110
1111                 stat_inc_seg_count(sbi, type, gc_type);
1112
1113                 if (gc_type == FG_GC &&
1114                                 get_valid_blocks(sbi, segno, false) == 0)
1115                         seg_freed++;
1116 next:
1117                 f2fs_put_page(sum_page, 0);
1118         }
1119
1120         if (gc_type == FG_GC)
1121                 f2fs_submit_merged_write(sbi,
1122                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1123
1124         blk_finish_plug(&plug);
1125
1126         stat_inc_call_count(sbi->stat_info);
1127
1128         return seg_freed;
1129 }
1130
1131 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1132                         bool background, unsigned int segno)
1133 {
1134         int gc_type = sync ? FG_GC : BG_GC;
1135         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1136         int ret = 0;
1137         struct cp_control cpc;
1138         unsigned int init_segno = segno;
1139         struct gc_inode_list gc_list = {
1140                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1141                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1142         };
1143         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1144         unsigned long long first_skipped;
1145         unsigned int skipped_round = 0, round = 0;
1146
1147         trace_f2fs_gc_begin(sbi->sb, sync, background,
1148                                 get_pages(sbi, F2FS_DIRTY_NODES),
1149                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1150                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1151                                 free_sections(sbi),
1152                                 free_segments(sbi),
1153                                 reserved_segments(sbi),
1154                                 prefree_segments(sbi));
1155
1156         cpc.reason = __get_cp_reason(sbi);
1157         sbi->skipped_gc_rwsem = 0;
1158         first_skipped = last_skipped;
1159 gc_more:
1160         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1161                 ret = -EINVAL;
1162                 goto stop;
1163         }
1164         if (unlikely(f2fs_cp_error(sbi))) {
1165                 ret = -EIO;
1166                 goto stop;
1167         }
1168
1169         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1170                 /*
1171                  * For example, if there are many prefree_segments below given
1172                  * threshold, we can make them free by checkpoint. Then, we
1173                  * secure free segments which doesn't need fggc any more.
1174                  */
1175                 if (prefree_segments(sbi)) {
1176                         ret = f2fs_write_checkpoint(sbi, &cpc);
1177                         if (ret)
1178                                 goto stop;
1179                 }
1180                 if (has_not_enough_free_secs(sbi, 0, 0))
1181                         gc_type = FG_GC;
1182         }
1183
1184         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1185         if (gc_type == BG_GC && !background) {
1186                 ret = -EINVAL;
1187                 goto stop;
1188         }
1189         if (!__get_victim(sbi, &segno, gc_type)) {
1190                 ret = -ENODATA;
1191                 goto stop;
1192         }
1193
1194         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1195         if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1196                 sec_freed++;
1197         total_freed += seg_freed;
1198
1199         if (gc_type == FG_GC) {
1200                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1201                                                 sbi->skipped_gc_rwsem)
1202                         skipped_round++;
1203                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1204                 round++;
1205         }
1206
1207         if (gc_type == FG_GC)
1208                 sbi->cur_victim_sec = NULL_SEGNO;
1209
1210         if (sync)
1211                 goto stop;
1212
1213         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1214                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1215                                         skipped_round * 2 < round) {
1216                         segno = NULL_SEGNO;
1217                         goto gc_more;
1218                 }
1219
1220                 if (first_skipped < last_skipped &&
1221                                 (last_skipped - first_skipped) >
1222                                                 sbi->skipped_gc_rwsem) {
1223                         f2fs_drop_inmem_pages_all(sbi, true);
1224                         segno = NULL_SEGNO;
1225                         goto gc_more;
1226                 }
1227                 if (gc_type == FG_GC)
1228                         ret = f2fs_write_checkpoint(sbi, &cpc);
1229         }
1230 stop:
1231         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1232         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1233
1234         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1235                                 get_pages(sbi, F2FS_DIRTY_NODES),
1236                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1237                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1238                                 free_sections(sbi),
1239                                 free_segments(sbi),
1240                                 reserved_segments(sbi),
1241                                 prefree_segments(sbi));
1242
1243         mutex_unlock(&sbi->gc_mutex);
1244
1245         put_gc_inode(&gc_list);
1246
1247         if (sync)
1248                 ret = sec_freed ? 0 : -EAGAIN;
1249         return ret;
1250 }
1251
1252 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1253 {
1254         DIRTY_I(sbi)->v_ops = &default_v_ops;
1255
1256         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1257
1258         /* give warm/cold data area from slower device */
1259         if (f2fs_is_multi_device(sbi) && sbi->segs_per_sec == 1)
1260                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1261                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1262 }