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 (get_valid_blocks(sbi, *result, false) &&
 322                         !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
 323                         p.min_segno = *result;
 324                 goto out;
 325         }
 326
 327         if (p.max_search == 0)
 328                 goto out;
 329
 330         last_victim = sm->last_victim[p.gc_mode];
 331         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 332                 p.min_segno = check_bg_victims(sbi);
 333                 if (p.min_segno != NULL_SEGNO)
 334                         goto got_it;
 335         }
 336
 337         while (1) {
 338                 unsigned long cost;
 339                 unsigned int segno;
 340
 341                 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
 342                 if (segno >= last_segment) {
 343                         if (sm->last_victim[p.gc_mode]) {
 344                                 last_segment =
 345                                         sm->last_victim[p.gc_mode];
 346                                 sm->last_victim[p.gc_mode] = 0;
 347                                 p.offset = 0;
 348                                 continue;
 349                         }
 350                         break;
 351                 }
 352
 353                 p.offset = segno + p.ofs_unit;
 354                 if (p.ofs_unit > 1) {
 355                         p.offset -= segno % p.ofs_unit;
 356                         nsearched += count_bits(p.dirty_segmap,
 357                                                 p.offset - p.ofs_unit,
 358                                                 p.ofs_unit);
 359                 } else {
 360                         nsearched++;
 361                 }
 362
 363                 secno = GET_SEC_FROM_SEG(sbi, segno);
 364
 365                 if (sec_usage_check(sbi, secno))
 366                         goto next;
 367                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 368                         goto next;
 369
 370                 cost = get_gc_cost(sbi, segno, &p);
 371
 372                 if (p.min_cost > cost) {
 373                         p.min_segno = segno;
 374                         p.min_cost = cost;
 375                 }
 376 next:
 377                 if (nsearched >= p.max_search) {
 378                         if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
 379                                 sm->last_victim[p.gc_mode] = last_victim + 1;
 380                         else
 381                                 sm->last_victim[p.gc_mode] = segno + 1;
 382                         sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
 383                         break;
 384                 }
 385         }
 386         if (p.min_segno != NULL_SEGNO) {
 387 got_it:
 388                 if (p.alloc_mode == LFS) {
 389                         secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
 390                         if (gc_type == FG_GC)
 391                                 sbi->cur_victim_sec = secno;
 392                         else
 393                                 set_bit(secno, dirty_i->victim_secmap);
 394                 }
 395                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 396
 397                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 398                                 sbi->cur_victim_sec,
 399                                 prefree_segments(sbi), free_segments(sbi));
 400         }
 401 out:
 402         mutex_unlock(&dirty_i->seglist_lock);
 403
 404         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 405 }
 406
 407 static const struct victim_selection default_v_ops = {
 408         .get_victim = get_victim_by_default,
 409 };
 410
 411 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
 412 {
 413         struct inode_entry *ie;
 414
 415         ie = radix_tree_lookup(&gc_list->iroot, ino);
 416         if (ie)
 417                 return ie->inode;
 418         return NULL;
 419 }
 420
 421 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
 422 {
 423         struct inode_entry *new_ie;
 424
 425         if (inode == find_gc_inode(gc_list, inode->i_ino)) {
 426                 iput(inode);
 427                 return;
 428         }
 429         new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS);
 430         new_ie->inode = inode;
 431
 432         f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
 433         list_add_tail(&new_ie->list, &gc_list->ilist);
 434 }
 435
 436 static void put_gc_inode(struct gc_inode_list *gc_list)
 437 {
 438         struct inode_entry *ie, *next_ie;
 439         list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
 440                 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
 441                 iput(ie->inode);
 442                 list_del(&ie->list);
 443                 kmem_cache_free(f2fs_inode_entry_slab, ie);
 444         }
 445 }
 446
 447 static int check_valid_map(struct f2fs_sb_info *sbi,
 448                                 unsigned int segno, int offset)
 449 {
 450         struct sit_info *sit_i = SIT_I(sbi);
 451         struct seg_entry *sentry;
 452         int ret;
 453
 454         down_read(&sit_i->sentry_lock);
 455         sentry = get_seg_entry(sbi, segno);
 456         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 457         up_read(&sit_i->sentry_lock);
 458         return ret;
 459 }
 460
 461 /*
 462  * This function compares node address got in summary with that in NAT.
 463  * On validity, copy that node with cold status, otherwise (invalid node)
 464  * ignore that.
 465  */
 466 static void gc_node_segment(struct f2fs_sb_info *sbi,
 467                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 468 {
 469         struct f2fs_summary *entry;
 470         block_t start_addr;
 471         int off;
 472         int phase = 0;
 473         bool fggc = (gc_type == FG_GC);
 474
 475         start_addr = START_BLOCK(sbi, segno);
 476
 477 next_step:
 478         entry = sum;
 479
 480         if (fggc && phase == 2)
 481                 atomic_inc(&sbi->wb_sync_req[NODE]);
 482
 483         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 484                 nid_t nid = le32_to_cpu(entry->nid);
 485                 struct page *node_page;
 486                 struct node_info ni;
 487
 488                 /* stop BG_GC if there is not enough free sections. */
 489                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 490                         return;
 491
 492                 if (check_valid_map(sbi, segno, off) == 0)
 493                         continue;
 494
 495                 if (phase == 0) {
 496                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 497                                                         META_NAT, true);
 498                         continue;
 499                 }
 500
 501                 if (phase == 1) {
 502                         f2fs_ra_node_page(sbi, nid);
 503                         continue;
 504                 }
 505
 506                 /* phase == 2 */
 507                 node_page = f2fs_get_node_page(sbi, nid);
 508                 if (IS_ERR(node_page))
 509                         continue;
 510
 511                 /* block may become invalid during f2fs_get_node_page */
 512                 if (check_valid_map(sbi, segno, off) == 0) {
 513                         f2fs_put_page(node_page, 1);
 514                         continue;
 515                 }
 516
 517                 if (f2fs_get_node_info(sbi, nid, &ni)) {
 518                         f2fs_put_page(node_page, 1);
 519                         continue;
 520                 }
 521
 522                 if (ni.blk_addr != start_addr + off) {
 523                         f2fs_put_page(node_page, 1);
 524                         continue;
 525                 }
 526
 527                 f2fs_move_node_page(node_page, gc_type);
 528                 stat_inc_node_blk_count(sbi, 1, gc_type);
 529         }
 530
 531         if (++phase < 3)
 532                 goto next_step;
 533
 534         if (fggc)
 535                 atomic_dec(&sbi->wb_sync_req[NODE]);
 536 }
 537
 538 /*
 539  * Calculate start block index indicating the given node offset.
 540  * Be careful, caller should give this node offset only indicating direct node
 541  * blocks. If any node offsets, which point the other types of node blocks such
 542  * as indirect or double indirect node blocks, are given, it must be a caller's
 543  * bug.
 544  */
 545 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
 546 {
 547         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 548         unsigned int bidx;
 549
 550         if (node_ofs == 0)
 551                 return 0;
 552
 553         if (node_ofs <= 2) {
 554                 bidx = node_ofs - 1;
 555         } else if (node_ofs <= indirect_blks) {
 556                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 557                 bidx = node_ofs - 2 - dec;
 558         } else {
 559                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 560                 bidx = node_ofs - 5 - dec;
 561         }
 562         return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
 563 }
 564
 565 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 566                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 567 {
 568         struct page *node_page;
 569         nid_t nid;
 570         unsigned int ofs_in_node;
 571         block_t source_blkaddr;
 572
 573         nid = le32_to_cpu(sum->nid);
 574         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 575
 576         node_page = f2fs_get_node_page(sbi, nid);
 577         if (IS_ERR(node_page))
 578                 return false;
 579
 580         if (f2fs_get_node_info(sbi, nid, dni)) {
 581                 f2fs_put_page(node_page, 1);
 582                 return false;
 583         }
 584
 585         if (sum->version != dni->version) {
 586                 f2fs_msg(sbi->sb, KERN_WARNING,
 587                                 "%s: valid data with mismatched node version.",
 588                                 __func__);
 589                 set_sbi_flag(sbi, SBI_NEED_FSCK);
 590         }
 591
 592         *nofs = ofs_of_node(node_page);
 593         source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
 594         f2fs_put_page(node_page, 1);
 595
 596         if (source_blkaddr != blkaddr)
 597                 return false;
 598         return true;
 599 }
 600
 601 static int ra_data_block(struct inode *inode, pgoff_t index)
 602 {
 603         struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
 604         struct address_space *mapping = inode->i_mapping;
 605         struct dnode_of_data dn;
 606         struct page *page;
 607         struct extent_info ei = {0, 0, 0};
 608         struct f2fs_io_info fio = {
 609                 .sbi = sbi,
 610                 .ino = inode->i_ino,
 611                 .type = DATA,
 612                 .temp = COLD,
 613                 .op = REQ_OP_READ,
 614                 .op_flags = 0,
 615                 .encrypted_page = NULL,
 616                 .in_list = false,
 617                 .retry = false,
 618         };
 619         int err;
 620
 621         page = f2fs_grab_cache_page(mapping, index, true);
 622         if (!page)
 623                 return -ENOMEM;
 624
 625         if (f2fs_lookup_extent_cache(inode, index, &ei)) {
 626                 dn.data_blkaddr = ei.blk + index - ei.fofs;
 627                 goto got_it;
 628         }
 629
 630         set_new_dnode(&dn, inode, NULL, NULL, 0);
 631         err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE);
 632         if (err)
 633                 goto put_page;
 634         f2fs_put_dnode(&dn);
 635
 636         if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr,
 637                                                 DATA_GENERIC))) {
 638                 err = -EFSCORRUPTED;
 639                 goto put_page;
 640         }
 641 got_it:
 642         /* read page */
 643         fio.page = page;
 644         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 645
 646         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi),
 647                                         dn.data_blkaddr,
 648                                         FGP_LOCK | FGP_CREAT, GFP_NOFS);
 649         if (!fio.encrypted_page) {
 650                 err = -ENOMEM;
 651                 goto put_page;
 652         }
 653
 654         err = f2fs_submit_page_bio(&fio);
 655         if (err)
 656                 goto put_encrypted_page;
 657         f2fs_put_page(fio.encrypted_page, 0);
 658         f2fs_put_page(page, 1);
 659         return 0;
 660 put_encrypted_page:
 661         f2fs_put_page(fio.encrypted_page, 1);
 662 put_page:
 663         f2fs_put_page(page, 1);
 664         return err;
 665 }
 666
 667 /*
 668  * Move data block via META_MAPPING while keeping locked data page.
 669  * This can be used to move blocks, aka LBAs, directly on disk.
 670  */
 671 static void move_data_block(struct inode *inode, block_t bidx,
 672                                 int gc_type, unsigned int segno, int off)
 673 {
 674         struct f2fs_io_info fio = {
 675                 .sbi = F2FS_I_SB(inode),
 676                 .ino = inode->i_ino,
 677                 .type = DATA,
 678                 .temp = COLD,
 679                 .op = REQ_OP_READ,
 680                 .op_flags = 0,
 681                 .encrypted_page = NULL,
 682                 .in_list = false,
 683                 .retry = false,
 684         };
 685         struct dnode_of_data dn;
 686         struct f2fs_summary sum;
 687         struct node_info ni;
 688         struct page *page, *mpage;
 689         block_t newaddr;
 690         int err;
 691         bool lfs_mode = test_opt(fio.sbi, LFS);
 692
 693         /* do not read out */
 694         page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
 695         if (!page)
 696                 return;
 697
 698         if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 699                 goto out;
 700
 701         if (f2fs_is_atomic_file(inode)) {
 702                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 703                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 704                 goto out;
 705         }
 706
 707         if (f2fs_is_pinned_file(inode)) {
 708                 f2fs_pin_file_control(inode, true);
 709                 goto out;
 710         }
 711
 712         set_new_dnode(&dn, inode, NULL, NULL, 0);
 713         err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
 714         if (err)
 715                 goto out;
 716
 717         if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
 718                 ClearPageUptodate(page);
 719                 goto put_out;
 720         }
 721
 722         /*
 723          * don't cache encrypted data into meta inode until previous dirty
 724          * data were writebacked to avoid racing between GC and flush.
 725          */
 726         f2fs_wait_on_page_writeback(page, DATA, true);
 727
 728         err = f2fs_get_node_info(fio.sbi, dn.nid, &ni);
 729         if (err)
 730                 goto put_out;
 731
 732         set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
 733
 734         /* read page */
 735         fio.page = page;
 736         fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
 737
 738         if (lfs_mode)
 739                 down_write(&fio.sbi->io_order_lock);
 740
 741         f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
 742                                         &sum, CURSEG_COLD_DATA, NULL, false);
 743
 744         fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 745                                 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
 746         if (!fio.encrypted_page) {
 747                 err = -ENOMEM;
 748                 goto recover_block;
 749         }
 750
 751         mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
 752                                         fio.old_blkaddr, FGP_LOCK, GFP_NOFS);
 753         if (mpage) {
 754                 bool updated = false;
 755
 756                 if (PageUptodate(mpage)) {
 757                         memcpy(page_address(fio.encrypted_page),
 758                                         page_address(mpage), PAGE_SIZE);
 759                         updated = true;
 760                 }
 761                 f2fs_put_page(mpage, 1);
 762                 invalidate_mapping_pages(META_MAPPING(fio.sbi),
 763                                         fio.old_blkaddr, fio.old_blkaddr);
 764                 if (updated)
 765                         goto write_page;
 766         }
 767
 768         err = f2fs_submit_page_bio(&fio);
 769         if (err)
 770                 goto put_page_out;
 771
 772         /* write page */
 773         lock_page(fio.encrypted_page);
 774
 775         if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
 776                 err = -EIO;
 777                 goto put_page_out;
 778         }
 779         if (unlikely(!PageUptodate(fio.encrypted_page))) {
 780                 err = -EIO;
 781                 goto put_page_out;
 782         }
 783
 784 write_page:
 785         set_page_dirty(fio.encrypted_page);
 786         f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
 787         if (clear_page_dirty_for_io(fio.encrypted_page))
 788                 dec_page_count(fio.sbi, F2FS_DIRTY_META);
 789
 790         set_page_writeback(fio.encrypted_page);
 791         ClearPageError(page);
 792
 793         /* allocate block address */
 794         f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
 795
 796         fio.op = REQ_OP_WRITE;
 797         fio.op_flags = REQ_SYNC;
 798         fio.new_blkaddr = newaddr;
 799         f2fs_submit_page_write(&fio);
 800         if (fio.retry) {
 801                 if (PageWriteback(fio.encrypted_page))
 802                         end_page_writeback(fio.encrypted_page);
 803                 goto put_page_out;
 804         }
 805
 806         f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
 807
 808         f2fs_update_data_blkaddr(&dn, newaddr);
 809         set_inode_flag(inode, FI_APPEND_WRITE);
 810         if (page->index == 0)
 811                 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
 812 put_page_out:
 813         f2fs_put_page(fio.encrypted_page, 1);
 814 recover_block:
 815         if (lfs_mode)
 816                 up_write(&fio.sbi->io_order_lock);
 817         if (err)
 818                 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
 819                                                                 true, true);
 820 put_out:
 821         f2fs_put_dnode(&dn);
 822 out:
 823         f2fs_put_page(page, 1);
 824 }
 825
 826 static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
 827                                                         unsigned int segno, int off)
 828 {
 829         struct page *page;
 830
 831         page = f2fs_get_lock_data_page(inode, bidx, true);
 832         if (IS_ERR(page))
 833                 return;
 834
 835         if (!check_valid_map(F2FS_I_SB(inode), segno, off))
 836                 goto out;
 837
 838         if (f2fs_is_atomic_file(inode)) {
 839                 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++;
 840                 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++;
 841                 goto out;
 842         }
 843         if (f2fs_is_pinned_file(inode)) {
 844                 if (gc_type == FG_GC)
 845                         f2fs_pin_file_control(inode, true);
 846                 goto out;
 847         }
 848
 849         if (gc_type == BG_GC) {
 850                 if (PageWriteback(page))
 851                         goto out;
 852                 set_page_dirty(page);
 853                 set_cold_data(page);
 854         } else {
 855                 struct f2fs_io_info fio = {
 856                         .sbi = F2FS_I_SB(inode),
 857                         .ino = inode->i_ino,
 858                         .type = DATA,
 859                         .temp = COLD,
 860                         .op = REQ_OP_WRITE,
 861                         .op_flags = REQ_SYNC,
 862                         .old_blkaddr = NULL_ADDR,
 863                         .page = page,
 864                         .encrypted_page = NULL,
 865                         .need_lock = LOCK_REQ,
 866                         .io_type = FS_GC_DATA_IO,
 867                 };
 868                 bool is_dirty = PageDirty(page);
 869                 int err;
 870
 871 retry:
 872                 set_page_dirty(page);
 873                 f2fs_wait_on_page_writeback(page, DATA, true);
 874                 if (clear_page_dirty_for_io(page)) {
 875                         inode_dec_dirty_pages(inode);
 876                         f2fs_remove_dirty_inode(inode);
 877                 }
 878
 879                 set_cold_data(page);
 880
 881                 err = f2fs_do_write_data_page(&fio);
 882                 if (err) {
 883                         clear_cold_data(page);
 884                         if (err == -ENOMEM) {
 885                                 congestion_wait(BLK_RW_ASYNC, HZ/50);
 886                                 goto retry;
 887                         }
 888                         if (is_dirty)
 889                                 set_page_dirty(page);
 890                 }
 891         }
 892 out:
 893         f2fs_put_page(page, 1);
 894 }
 895
 896 /*
 897  * This function tries to get parent node of victim data block, and identifies
 898  * data block validity. If the block is valid, copy that with cold status and
 899  * modify parent node.
 900  * If the parent node is not valid or the data block address is different,
 901  * the victim data block is ignored.
 902  */
 903 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 904                 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
 905 {
 906         struct super_block *sb = sbi->sb;
 907         struct f2fs_summary *entry;
 908         block_t start_addr;
 909         int off;
 910         int phase = 0;
 911
 912         start_addr = START_BLOCK(sbi, segno);
 913
 914 next_step:
 915         entry = sum;
 916
 917         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 918                 struct page *data_page;
 919                 struct inode *inode;
 920                 struct node_info dni; /* dnode info for the data */
 921                 unsigned int ofs_in_node, nofs;
 922                 block_t start_bidx;
 923                 nid_t nid = le32_to_cpu(entry->nid);
 924
 925                 /* stop BG_GC if there is not enough free sections. */
 926                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
 927                         return;
 928
 929                 if (check_valid_map(sbi, segno, off) == 0)
 930                         continue;
 931
 932                 if (phase == 0) {
 933                         f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
 934                                                         META_NAT, true);
 935                         continue;
 936                 }
 937
 938                 if (phase == 1) {
 939                         f2fs_ra_node_page(sbi, nid);
 940                         continue;
 941                 }
 942
 943                 /* Get an inode by ino with checking validity */
 944                 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
 945                         continue;
 946
 947                 if (phase == 2) {
 948                         f2fs_ra_node_page(sbi, dni.ino);
 949                         continue;
 950                 }
 951
 952                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
 953
 954                 if (phase == 3) {
 955                         inode = f2fs_iget(sb, dni.ino);
 956                         if (IS_ERR(inode) || is_bad_inode(inode))
 957                                 continue;
 958
 959                         if (!down_write_trylock(
 960                                 &F2FS_I(inode)->i_gc_rwsem[WRITE])) {
 961                                 iput(inode);
 962                                 sbi->skipped_gc_rwsem++;
 963                                 continue;
 964                         }
 965
 966                         start_bidx = f2fs_start_bidx_of_node(nofs, inode) +
 967                                                                 ofs_in_node;
 968
 969                         if (f2fs_post_read_required(inode)) {
 970                                 int err = ra_data_block(inode, start_bidx);
 971
 972                                 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 973                                 if (err) {
 974                                         iput(inode);
 975                                         continue;
 976                                 }
 977                                 add_gc_inode(gc_list, inode);
 978                                 continue;
 979                         }
 980
 981                         data_page = f2fs_get_read_data_page(inode,
 982                                                 start_bidx, REQ_RAHEAD, true);
 983                         up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]);
 984                         if (IS_ERR(data_page)) {
 985                                 iput(inode);
 986                                 continue;
 987                         }
 988
 989                         f2fs_put_page(data_page, 0);
 990                         add_gc_inode(gc_list, inode);
 991                         continue;
 992                 }
 993
 994                 /* phase 4 */
 995                 inode = find_gc_inode(gc_list, dni.ino);
 996                 if (inode) {
 997                         struct f2fs_inode_info *fi = F2FS_I(inode);
 998                         bool locked = false;
 999
1000                         if (S_ISREG(inode->i_mode)) {
1001                                 if (!down_write_trylock(&fi->i_gc_rwsem[READ])) {
1002                                         sbi->skipped_gc_rwsem++;
1003                                         continue;
1004                                 }
1005                                 if (!down_write_trylock(
1006                                                 &fi->i_gc_rwsem[WRITE])) {
1007                                         sbi->skipped_gc_rwsem++;
1008                                         up_write(&fi->i_gc_rwsem[READ]);
1009                                         continue;
1010                                 }
1011                                 locked = true;
1012
1013                                 /* wait for all inflight aio data */
1014                                 inode_dio_wait(inode);
1015                         }
1016
1017                         start_bidx = f2fs_start_bidx_of_node(nofs, inode)
1018                                                                 + ofs_in_node;
1019                         if (f2fs_post_read_required(inode))
1020                                 move_data_block(inode, start_bidx, gc_type,
1021                                                                 segno, off);
1022                         else
1023                                 move_data_page(inode, start_bidx, gc_type,
1024                                                                 segno, off);
1025
1026                         if (locked) {
1027                                 up_write(&fi->i_gc_rwsem[WRITE]);
1028                                 up_write(&fi->i_gc_rwsem[READ]);
1029                         }
1030
1031                         stat_inc_data_blk_count(sbi, 1, gc_type);
1032                 }
1033         }
1034
1035         if (++phase < 5)
1036                 goto next_step;
1037 }
1038
1039 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
1040                         int gc_type)
1041 {
1042         struct sit_info *sit_i = SIT_I(sbi);
1043         int ret;
1044
1045         down_write(&sit_i->sentry_lock);
1046         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
1047                                               NO_CHECK_TYPE, LFS);
1048         up_write(&sit_i->sentry_lock);
1049         return ret;
1050 }
1051
1052 static int do_garbage_collect(struct f2fs_sb_info *sbi,
1053                                 unsigned int start_segno,
1054                                 struct gc_inode_list *gc_list, int gc_type)
1055 {
1056         struct page *sum_page;
1057         struct f2fs_summary_block *sum;
1058         struct blk_plug plug;
1059         unsigned int segno = start_segno;
1060         unsigned int end_segno = start_segno + sbi->segs_per_sec;
1061         int seg_freed = 0;
1062         unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
1063                                                 SUM_TYPE_DATA : SUM_TYPE_NODE;
1064
1065         /* readahead multi ssa blocks those have contiguous address */
1066         if (sbi->segs_per_sec > 1)
1067                 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
1068                                         sbi->segs_per_sec, META_SSA, true);
1069
1070         /* reference all summary page */
1071         while (segno < end_segno) {
1072                 sum_page = f2fs_get_sum_page(sbi, segno++);
1073                 unlock_page(sum_page);
1074         }
1075
1076         blk_start_plug(&plug);
1077
1078         for (segno = start_segno; segno < end_segno; segno++) {
1079
1080                 /* find segment summary of victim */
1081                 sum_page = find_get_page(META_MAPPING(sbi),
1082                                         GET_SUM_BLOCK(sbi, segno));
1083                 f2fs_put_page(sum_page, 0);
1084
1085                 if (get_valid_blocks(sbi, segno, false) == 0)
1086                         goto freed;
1087                 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi)))
1088                         goto next;
1089
1090                 sum = page_address(sum_page);
1091                 if (type != GET_SUM_TYPE((&sum->footer))) {
1092                         f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) "
1093                                 "type [%d, %d] in SSA and SIT",
1094                                 segno, type, GET_SUM_TYPE((&sum->footer)));
1095                         set_sbi_flag(sbi, SBI_NEED_FSCK);
1096                         goto next;
1097                 }
1098
1099                 /*
1100                  * this is to avoid deadlock:
1101                  * - lock_page(sum_page)         - f2fs_replace_block
1102                  *  - check_valid_map()            - down_write(sentry_lock)
1103                  *   - down_read(sentry_lock)     - change_curseg()
1104                  *                                  - lock_page(sum_page)
1105                  */
1106                 if (type == SUM_TYPE_NODE)
1107                         gc_node_segment(sbi, sum->entries, segno, gc_type);
1108                 else
1109                         gc_data_segment(sbi, sum->entries, gc_list, segno,
1110                                                                 gc_type);
1111
1112                 stat_inc_seg_count(sbi, type, gc_type);
1113
1114 freed:
1115                 if (gc_type == FG_GC &&
1116                                 get_valid_blocks(sbi, segno, false) == 0)
1117                         seg_freed++;
1118 next:
1119                 f2fs_put_page(sum_page, 0);
1120         }
1121
1122         if (gc_type == FG_GC)
1123                 f2fs_submit_merged_write(sbi,
1124                                 (type == SUM_TYPE_NODE) ? NODE : DATA);
1125
1126         blk_finish_plug(&plug);
1127
1128         stat_inc_call_count(sbi->stat_info);
1129
1130         return seg_freed;
1131 }
1132
1133 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1134                         bool background, unsigned int segno)
1135 {
1136         int gc_type = sync ? FG_GC : BG_GC;
1137         int sec_freed = 0, seg_freed = 0, total_freed = 0;
1138         int ret = 0;
1139         struct cp_control cpc;
1140         unsigned int init_segno = segno;
1141         struct gc_inode_list gc_list = {
1142                 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1143                 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS),
1144         };
1145         unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC];
1146         unsigned long long first_skipped;
1147         unsigned int skipped_round = 0, round = 0;
1148
1149         trace_f2fs_gc_begin(sbi->sb, sync, background,
1150                                 get_pages(sbi, F2FS_DIRTY_NODES),
1151                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1152                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1153                                 free_sections(sbi),
1154                                 free_segments(sbi),
1155                                 reserved_segments(sbi),
1156                                 prefree_segments(sbi));
1157
1158         cpc.reason = __get_cp_reason(sbi);
1159         sbi->skipped_gc_rwsem = 0;
1160         first_skipped = last_skipped;
1161 gc_more:
1162         if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) {
1163                 ret = -EINVAL;
1164                 goto stop;
1165         }
1166         if (unlikely(f2fs_cp_error(sbi))) {
1167                 ret = -EIO;
1168                 goto stop;
1169         }
1170
1171         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1172                 /*
1173                  * For example, if there are many prefree_segments below given
1174                  * threshold, we can make them free by checkpoint. Then, we
1175                  * secure free segments which doesn't need fggc any more.
1176                  */
1177                 if (prefree_segments(sbi)) {
1178                         ret = f2fs_write_checkpoint(sbi, &cpc);
1179                         if (ret)
1180                                 goto stop;
1181                 }
1182                 if (has_not_enough_free_secs(sbi, 0, 0))
1183                         gc_type = FG_GC;
1184         }
1185
1186         /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1187         if (gc_type == BG_GC && !background) {
1188                 ret = -EINVAL;
1189                 goto stop;
1190         }
1191         if (!__get_victim(sbi, &segno, gc_type)) {
1192                 ret = -ENODATA;
1193                 goto stop;
1194         }
1195
1196         seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1197         if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1198                 sec_freed++;
1199         total_freed += seg_freed;
1200
1201         if (gc_type == FG_GC) {
1202                 if (sbi->skipped_atomic_files[FG_GC] > last_skipped ||
1203                                                 sbi->skipped_gc_rwsem)
1204                         skipped_round++;
1205                 last_skipped = sbi->skipped_atomic_files[FG_GC];
1206                 round++;
1207         }
1208
1209         if (gc_type == FG_GC)
1210                 sbi->cur_victim_sec = NULL_SEGNO;
1211
1212         if (sync)
1213                 goto stop;
1214
1215         if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1216                 if (skipped_round <= MAX_SKIP_GC_COUNT ||
1217                                         skipped_round * 2 < round) {
1218                         segno = NULL_SEGNO;
1219                         goto gc_more;
1220                 }
1221
1222                 if (first_skipped < last_skipped &&
1223                                 (last_skipped - first_skipped) >
1224                                                 sbi->skipped_gc_rwsem) {
1225                         f2fs_drop_inmem_pages_all(sbi, true);
1226                         segno = NULL_SEGNO;
1227                         goto gc_more;
1228                 }
1229                 if (gc_type == FG_GC)
1230                         ret = f2fs_write_checkpoint(sbi, &cpc);
1231         }
1232 stop:
1233         SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1234         SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1235
1236         trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1237                                 get_pages(sbi, F2FS_DIRTY_NODES),
1238                                 get_pages(sbi, F2FS_DIRTY_DENTS),
1239                                 get_pages(sbi, F2FS_DIRTY_IMETA),
1240                                 free_sections(sbi),
1241                                 free_segments(sbi),
1242                                 reserved_segments(sbi),
1243                                 prefree_segments(sbi));
1244
1245         mutex_unlock(&sbi->gc_mutex);
1246
1247         put_gc_inode(&gc_list);
1248
1249         if (sync && !ret)
1250                 ret = sec_freed ? 0 : -EAGAIN;
1251         return ret;
1252 }
1253
1254 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi)
1255 {
1256         DIRTY_I(sbi)->v_ops = &default_v_ops;
1257
1258         sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1259
1260         /* give warm/cold data area from slower device */
1261         if (f2fs_is_multi_device(sbi) && sbi->segs_per_sec == 1)
1262                 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1263                                 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1264 }