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/proc_fs.h>
  15 #include <linux/init.h>
  16 #include <linux/f2fs_fs.h>
  17 #include <linux/kthread.h>
  18 #include <linux/delay.h>
  19 #include <linux/freezer.h>
  20 #include <linux/blkdev.h>
  21
  22 #include "f2fs.h"
  23 #include "node.h"
  24 #include "segment.h"
  25 #include "gc.h"
  26 #include <trace/events/f2fs.h>
  27
  28 static struct kmem_cache *winode_slab;
  29
  30 static int gc_thread_func(void *data)
  31 {
  32         struct f2fs_sb_info *sbi = data;
  33         wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
  34         long wait_ms;
  35
  36         wait_ms = GC_THREAD_MIN_SLEEP_TIME;
  37
  38         do {
  39                 if (try_to_freeze())
  40                         continue;
  41                 else
  42                         wait_event_interruptible_timeout(*wq,
  43                                                 kthread_should_stop(),
  44                                                 msecs_to_jiffies(wait_ms));
  45                 if (kthread_should_stop())
  46                         break;
  47
  48                 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
  49                         wait_ms = GC_THREAD_MAX_SLEEP_TIME;
  50                         continue;
  51                 }
  52
  53                 /*
  54                  * [GC triggering condition]
  55                  * 0. GC is not conducted currently.
  56                  * 1. There are enough dirty segments.
  57                  * 2. IO subsystem is idle by checking the # of writeback pages.
  58                  * 3. IO subsystem is idle by checking the # of requests in
  59                  *    bdev's request list.
  60                  *
  61                  * Note) We have to avoid triggering GCs too much frequently.
  62                  * Because it is possible that some segments can be
  63                  * invalidated soon after by user update or deletion.
  64                  * So, I'd like to wait some time to collect dirty segments.
  65                  */
  66                 if (!mutex_trylock(&sbi->gc_mutex))
  67                         continue;
  68
  69                 if (!is_idle(sbi)) {
  70                         wait_ms = increase_sleep_time(wait_ms);
  71                         mutex_unlock(&sbi->gc_mutex);
  72                         continue;
  73                 }
  74
  75                 if (has_enough_invalid_blocks(sbi))
  76                         wait_ms = decrease_sleep_time(wait_ms);
  77                 else
  78                         wait_ms = increase_sleep_time(wait_ms);
  79
  80                 sbi->bg_gc++;
  81
  82                 /* if return value is not zero, no victim was selected */
  83                 if (f2fs_gc(sbi))
  84                         wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
  85         } while (!kthread_should_stop());
  86         return 0;
  87 }
  88
  89 int start_gc_thread(struct f2fs_sb_info *sbi)
  90 {
  91         struct f2fs_gc_kthread *gc_th;
  92         dev_t dev = sbi->sb->s_bdev->bd_dev;
  93
  94         if (!test_opt(sbi, BG_GC))
  95                 return 0;
  96         gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
  97         if (!gc_th)
  98                 return -ENOMEM;
  99
 100         sbi->gc_thread = gc_th;
 101         init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
 102         sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
 103                         "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
 104         if (IS_ERR(gc_th->f2fs_gc_task)) {
 105                 kfree(gc_th);
 106                 sbi->gc_thread = NULL;
 107                 return -ENOMEM;
 108         }
 109         return 0;
 110 }
 111
 112 void stop_gc_thread(struct f2fs_sb_info *sbi)
 113 {
 114         struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
 115         if (!gc_th)
 116                 return;
 117         kthread_stop(gc_th->f2fs_gc_task);
 118         kfree(gc_th);
 119         sbi->gc_thread = NULL;
 120 }
 121
 122 static int select_gc_type(int gc_type)
 123 {
 124         return (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
 125 }
 126
 127 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
 128                         int type, struct victim_sel_policy *p)
 129 {
 130         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 131
 132         if (p->alloc_mode == SSR) {
 133                 p->gc_mode = GC_GREEDY;
 134                 p->dirty_segmap = dirty_i->dirty_segmap[type];
 135                 p->ofs_unit = 1;
 136         } else {
 137                 p->gc_mode = select_gc_type(gc_type);
 138                 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
 139                 p->ofs_unit = sbi->segs_per_sec;
 140         }
 141         p->offset = sbi->last_victim[p->gc_mode];
 142 }
 143
 144 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
 145                                 struct victim_sel_policy *p)
 146 {
 147         /* SSR allocates in a segment unit */
 148         if (p->alloc_mode == SSR)
 149                 return 1 << sbi->log_blocks_per_seg;
 150         if (p->gc_mode == GC_GREEDY)
 151                 return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
 152         else if (p->gc_mode == GC_CB)
 153                 return UINT_MAX;
 154         else /* No other gc_mode */
 155                 return 0;
 156 }
 157
 158 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
 159 {
 160         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 161         unsigned int hint = 0;
 162         unsigned int secno;
 163
 164         /*
 165          * If the gc_type is FG_GC, we can select victim segments
 166          * selected by background GC before.
 167          * Those segments guarantee they have small valid blocks.
 168          */
 169 next:
 170         secno = find_next_bit(dirty_i->victim_secmap, TOTAL_SECS(sbi), hint++);
 171         if (secno < TOTAL_SECS(sbi)) {
 172                 if (sec_usage_check(sbi, secno))
 173                         goto next;
 174                 clear_bit(secno, dirty_i->victim_secmap);
 175                 return secno * sbi->segs_per_sec;
 176         }
 177         return NULL_SEGNO;
 178 }
 179
 180 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
 181 {
 182         struct sit_info *sit_i = SIT_I(sbi);
 183         unsigned int secno = GET_SECNO(sbi, segno);
 184         unsigned int start = secno * sbi->segs_per_sec;
 185         unsigned long long mtime = 0;
 186         unsigned int vblocks;
 187         unsigned char age = 0;
 188         unsigned char u;
 189         unsigned int i;
 190
 191         for (i = 0; i < sbi->segs_per_sec; i++)
 192                 mtime += get_seg_entry(sbi, start + i)->mtime;
 193         vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
 194
 195         mtime = div_u64(mtime, sbi->segs_per_sec);
 196         vblocks = div_u64(vblocks, sbi->segs_per_sec);
 197
 198         u = (vblocks * 100) >> sbi->log_blocks_per_seg;
 199
 200         /* Handle if the system time is changed by user */
 201         if (mtime < sit_i->min_mtime)
 202                 sit_i->min_mtime = mtime;
 203         if (mtime > sit_i->max_mtime)
 204                 sit_i->max_mtime = mtime;
 205         if (sit_i->max_mtime != sit_i->min_mtime)
 206                 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
 207                                 sit_i->max_mtime - sit_i->min_mtime);
 208
 209         return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
 210 }
 211
 212 static unsigned int get_gc_cost(struct f2fs_sb_info *sbi, unsigned int segno,
 213                                         struct victim_sel_policy *p)
 214 {
 215         if (p->alloc_mode == SSR)
 216                 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
 217
 218         /* alloc_mode == LFS */
 219         if (p->gc_mode == GC_GREEDY)
 220                 return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
 221         else
 222                 return get_cb_cost(sbi, segno);
 223 }
 224
 225 /*
 226  * This function is called from two paths.
 227  * One is garbage collection and the other is SSR segment selection.
 228  * When it is called during GC, it just gets a victim segment
 229  * and it does not remove it from dirty seglist.
 230  * When it is called from SSR segment selection, it finds a segment
 231  * which has minimum valid blocks and removes it from dirty seglist.
 232  */
 233 static int get_victim_by_default(struct f2fs_sb_info *sbi,
 234                 unsigned int *result, int gc_type, int type, char alloc_mode)
 235 {
 236         struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
 237         struct victim_sel_policy p;
 238         unsigned int secno;
 239         int nsearched = 0;
 240
 241         p.alloc_mode = alloc_mode;
 242         select_policy(sbi, gc_type, type, &p);
 243
 244         p.min_segno = NULL_SEGNO;
 245         p.min_cost = get_max_cost(sbi, &p);
 246
 247         mutex_lock(&dirty_i->seglist_lock);
 248
 249         if (p.alloc_mode == LFS && gc_type == FG_GC) {
 250                 p.min_segno = check_bg_victims(sbi);
 251                 if (p.min_segno != NULL_SEGNO)
 252                         goto got_it;
 253         }
 254
 255         while (1) {
 256                 unsigned long cost;
 257                 unsigned int segno;
 258
 259                 segno = find_next_bit(p.dirty_segmap,
 260                                                 TOTAL_SEGS(sbi), p.offset);
 261                 if (segno >= TOTAL_SEGS(sbi)) {
 262                         if (sbi->last_victim[p.gc_mode]) {
 263                                 sbi->last_victim[p.gc_mode] = 0;
 264                                 p.offset = 0;
 265                                 continue;
 266                         }
 267                         break;
 268                 }
 269                 p.offset = ((segno / p.ofs_unit) * p.ofs_unit) + p.ofs_unit;
 270                 secno = GET_SECNO(sbi, segno);
 271
 272                 if (sec_usage_check(sbi, secno))
 273                         continue;
 274                 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
 275                         continue;
 276
 277                 cost = get_gc_cost(sbi, segno, &p);
 278
 279                 if (p.min_cost > cost) {
 280                         p.min_segno = segno;
 281                         p.min_cost = cost;
 282                 }
 283
 284                 if (cost == get_max_cost(sbi, &p))
 285                         continue;
 286
 287                 if (nsearched++ >= MAX_VICTIM_SEARCH) {
 288                         sbi->last_victim[p.gc_mode] = segno;
 289                         break;
 290                 }
 291         }
 292 got_it:
 293         if (p.min_segno != NULL_SEGNO) {
 294                 if (p.alloc_mode == LFS) {
 295                         secno = GET_SECNO(sbi, p.min_segno);
 296                         if (gc_type == FG_GC)
 297                                 sbi->cur_victim_sec = secno;
 298                         else
 299                                 set_bit(secno, dirty_i->victim_secmap);
 300                 }
 301                 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
 302
 303                 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
 304                                 sbi->cur_victim_sec,
 305                                 prefree_segments(sbi), free_segments(sbi));
 306         }
 307         mutex_unlock(&dirty_i->seglist_lock);
 308
 309         return (p.min_segno == NULL_SEGNO) ? 0 : 1;
 310 }
 311
 312 static const struct victim_selection default_v_ops = {
 313         .get_victim = get_victim_by_default,
 314 };
 315
 316 static struct inode *find_gc_inode(nid_t ino, struct list_head *ilist)
 317 {
 318         struct list_head *this;
 319         struct inode_entry *ie;
 320
 321         list_for_each(this, ilist) {
 322                 ie = list_entry(this, struct inode_entry, list);
 323                 if (ie->inode->i_ino == ino)
 324                         return ie->inode;
 325         }
 326         return NULL;
 327 }
 328
 329 static void add_gc_inode(struct inode *inode, struct list_head *ilist)
 330 {
 331         struct list_head *this;
 332         struct inode_entry *new_ie, *ie;
 333
 334         list_for_each(this, ilist) {
 335                 ie = list_entry(this, struct inode_entry, list);
 336                 if (ie->inode == inode) {
 337                         iput(inode);
 338                         return;
 339                 }
 340         }
 341 repeat:
 342         new_ie = kmem_cache_alloc(winode_slab, GFP_NOFS);
 343         if (!new_ie) {
 344                 cond_resched();
 345                 goto repeat;
 346         }
 347         new_ie->inode = inode;
 348         list_add_tail(&new_ie->list, ilist);
 349 }
 350
 351 static void put_gc_inode(struct list_head *ilist)
 352 {
 353         struct inode_entry *ie, *next_ie;
 354         list_for_each_entry_safe(ie, next_ie, ilist, list) {
 355                 iput(ie->inode);
 356                 list_del(&ie->list);
 357                 kmem_cache_free(winode_slab, ie);
 358         }
 359 }
 360
 361 static int check_valid_map(struct f2fs_sb_info *sbi,
 362                                 unsigned int segno, int offset)
 363 {
 364         struct sit_info *sit_i = SIT_I(sbi);
 365         struct seg_entry *sentry;
 366         int ret;
 367
 368         mutex_lock(&sit_i->sentry_lock);
 369         sentry = get_seg_entry(sbi, segno);
 370         ret = f2fs_test_bit(offset, sentry->cur_valid_map);
 371         mutex_unlock(&sit_i->sentry_lock);
 372         return ret;
 373 }
 374
 375 /*
 376  * This function compares node address got in summary with that in NAT.
 377  * On validity, copy that node with cold status, otherwise (invalid node)
 378  * ignore that.
 379  */
 380 static void gc_node_segment(struct f2fs_sb_info *sbi,
 381                 struct f2fs_summary *sum, unsigned int segno, int gc_type)
 382 {
 383         bool initial = true;
 384         struct f2fs_summary *entry;
 385         int off;
 386
 387 next_step:
 388         entry = sum;
 389
 390         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 391                 nid_t nid = le32_to_cpu(entry->nid);
 392                 struct page *node_page;
 393
 394                 /* stop BG_GC if there is not enough free sections. */
 395                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
 396                         return;
 397
 398                 if (check_valid_map(sbi, segno, off) == 0)
 399                         continue;
 400
 401                 if (initial) {
 402                         ra_node_page(sbi, nid);
 403                         continue;
 404                 }
 405                 node_page = get_node_page(sbi, nid);
 406                 if (IS_ERR(node_page))
 407                         continue;
 408
 409                 /* set page dirty and write it */
 410                 if (gc_type == FG_GC) {
 411                         f2fs_submit_bio(sbi, NODE, true);
 412                         wait_on_page_writeback(node_page);
 413                         set_page_dirty(node_page);
 414                 } else {
 415                         if (!PageWriteback(node_page))
 416                                 set_page_dirty(node_page);
 417                 }
 418                 f2fs_put_page(node_page, 1);
 419                 stat_inc_node_blk_count(sbi, 1);
 420         }
 421
 422         if (initial) {
 423                 initial = false;
 424                 goto next_step;
 425         }
 426
 427         if (gc_type == FG_GC) {
 428                 struct writeback_control wbc = {
 429                         .sync_mode = WB_SYNC_ALL,
 430                         .nr_to_write = LONG_MAX,
 431                         .for_reclaim = 0,
 432                 };
 433                 sync_node_pages(sbi, 0, &wbc);
 434
 435                 /*
 436                  * In the case of FG_GC, it'd be better to reclaim this victim
 437                  * completely.
 438                  */
 439                 if (get_valid_blocks(sbi, segno, 1) != 0)
 440                         goto next_step;
 441         }
 442 }
 443
 444 /*
 445  * Calculate start block index indicating the given node offset.
 446  * Be careful, caller should give this node offset only indicating direct node
 447  * blocks. If any node offsets, which point the other types of node blocks such
 448  * as indirect or double indirect node blocks, are given, it must be a caller's
 449  * bug.
 450  */
 451 block_t start_bidx_of_node(unsigned int node_ofs)
 452 {
 453         unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
 454         unsigned int bidx;
 455
 456         if (node_ofs == 0)
 457                 return 0;
 458
 459         if (node_ofs <= 2) {
 460                 bidx = node_ofs - 1;
 461         } else if (node_ofs <= indirect_blks) {
 462                 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
 463                 bidx = node_ofs - 2 - dec;
 464         } else {
 465                 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
 466                 bidx = node_ofs - 5 - dec;
 467         }
 468         return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE;
 469 }
 470
 471 static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 472                 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
 473 {
 474         struct page *node_page;
 475         nid_t nid;
 476         unsigned int ofs_in_node;
 477         block_t source_blkaddr;
 478
 479         nid = le32_to_cpu(sum->nid);
 480         ofs_in_node = le16_to_cpu(sum->ofs_in_node);
 481
 482         node_page = get_node_page(sbi, nid);
 483         if (IS_ERR(node_page))
 484                 return 0;
 485
 486         get_node_info(sbi, nid, dni);
 487
 488         if (sum->version != dni->version) {
 489                 f2fs_put_page(node_page, 1);
 490                 return 0;
 491         }
 492
 493         *nofs = ofs_of_node(node_page);
 494         source_blkaddr = datablock_addr(node_page, ofs_in_node);
 495         f2fs_put_page(node_page, 1);
 496
 497         if (source_blkaddr != blkaddr)
 498                 return 0;
 499         return 1;
 500 }
 501
 502 static void move_data_page(struct inode *inode, struct page *page, int gc_type)
 503 {
 504         if (gc_type == BG_GC) {
 505                 if (PageWriteback(page))
 506                         goto out;
 507                 set_page_dirty(page);
 508                 set_cold_data(page);
 509         } else {
 510                 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
 511
 512                 if (PageWriteback(page)) {
 513                         f2fs_submit_bio(sbi, DATA, true);
 514                         wait_on_page_writeback(page);
 515                 }
 516
 517                 if (clear_page_dirty_for_io(page) &&
 518                         S_ISDIR(inode->i_mode)) {
 519                         dec_page_count(sbi, F2FS_DIRTY_DENTS);
 520                         inode_dec_dirty_dents(inode);
 521                 }
 522                 set_cold_data(page);
 523                 do_write_data_page(page);
 524                 clear_cold_data(page);
 525         }
 526 out:
 527         f2fs_put_page(page, 1);
 528 }
 529
 530 /*
 531  * This function tries to get parent node of victim data block, and identifies
 532  * data block validity. If the block is valid, copy that with cold status and
 533  * modify parent node.
 534  * If the parent node is not valid or the data block address is different,
 535  * the victim data block is ignored.
 536  */
 537 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
 538                 struct list_head *ilist, unsigned int segno, int gc_type)
 539 {
 540         struct super_block *sb = sbi->sb;
 541         struct f2fs_summary *entry;
 542         block_t start_addr;
 543         int off;
 544         int phase = 0;
 545
 546         start_addr = START_BLOCK(sbi, segno);
 547
 548 next_step:
 549         entry = sum;
 550
 551         for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
 552                 struct page *data_page;
 553                 struct inode *inode;
 554                 struct node_info dni; /* dnode info for the data */
 555                 unsigned int ofs_in_node, nofs;
 556                 block_t start_bidx;
 557
 558                 /* stop BG_GC if there is not enough free sections. */
 559                 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
 560                         return;
 561
 562                 if (check_valid_map(sbi, segno, off) == 0)
 563                         continue;
 564
 565                 if (phase == 0) {
 566                         ra_node_page(sbi, le32_to_cpu(entry->nid));
 567                         continue;
 568                 }
 569
 570                 /* Get an inode by ino with checking validity */
 571                 if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0)
 572                         continue;
 573
 574                 if (phase == 1) {
 575                         ra_node_page(sbi, dni.ino);
 576                         continue;
 577                 }
 578
 579                 start_bidx = start_bidx_of_node(nofs);
 580                 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
 581
 582                 if (phase == 2) {
 583                         inode = f2fs_iget(sb, dni.ino);
 584                         if (IS_ERR(inode))
 585                                 continue;
 586
 587                         data_page = find_data_page(inode,
 588                                         start_bidx + ofs_in_node, false);
 589                         if (IS_ERR(data_page))
 590                                 goto next_iput;
 591
 592                         f2fs_put_page(data_page, 0);
 593                         add_gc_inode(inode, ilist);
 594                 } else {
 595                         inode = find_gc_inode(dni.ino, ilist);
 596                         if (inode) {
 597                                 data_page = get_lock_data_page(inode,
 598                                                 start_bidx + ofs_in_node);
 599                                 if (IS_ERR(data_page))
 600                                         continue;
 601                                 move_data_page(inode, data_page, gc_type);
 602                                 stat_inc_data_blk_count(sbi, 1);
 603                         }
 604                 }
 605                 continue;
 606 next_iput:
 607                 iput(inode);
 608         }
 609
 610         if (++phase < 4)
 611                 goto next_step;
 612
 613         if (gc_type == FG_GC) {
 614                 f2fs_submit_bio(sbi, DATA, true);
 615
 616                 /*
 617                  * In the case of FG_GC, it'd be better to reclaim this victim
 618                  * completely.
 619                  */
 620                 if (get_valid_blocks(sbi, segno, 1) != 0) {
 621                         phase = 2;
 622                         goto next_step;
 623                 }
 624         }
 625 }
 626
 627 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
 628                                                 int gc_type, int type)
 629 {
 630         struct sit_info *sit_i = SIT_I(sbi);
 631         int ret;
 632         mutex_lock(&sit_i->sentry_lock);
 633         ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, type, LFS);
 634         mutex_unlock(&sit_i->sentry_lock);
 635         return ret;
 636 }
 637
 638 static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
 639                                 struct list_head *ilist, int gc_type)
 640 {
 641         struct page *sum_page;
 642         struct f2fs_summary_block *sum;
 643         struct blk_plug plug;
 644
 645         /* read segment summary of victim */
 646         sum_page = get_sum_page(sbi, segno);
 647         if (IS_ERR(sum_page))
 648                 return;
 649
 650         blk_start_plug(&plug);
 651
 652         sum = page_address(sum_page);
 653
 654         switch (GET_SUM_TYPE((&sum->footer))) {
 655         case SUM_TYPE_NODE:
 656                 gc_node_segment(sbi, sum->entries, segno, gc_type);
 657                 break;
 658         case SUM_TYPE_DATA:
 659                 gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
 660                 break;
 661         }
 662         blk_finish_plug(&plug);
 663
 664         stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
 665         stat_inc_call_count(sbi->stat_info);
 666
 667         f2fs_put_page(sum_page, 1);
 668 }
 669
 670 int f2fs_gc(struct f2fs_sb_info *sbi)
 671 {
 672         struct list_head ilist;
 673         unsigned int segno, i;
 674         int gc_type = BG_GC;
 675         int nfree = 0;
 676         int ret = -1;
 677
 678         INIT_LIST_HEAD(&ilist);
 679 gc_more:
 680         if (!(sbi->sb->s_flags & MS_ACTIVE))
 681                 goto stop;
 682
 683         if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) {
 684                 gc_type = FG_GC;
 685                 write_checkpoint(sbi, false);
 686         }
 687
 688         if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
 689                 goto stop;
 690         ret = 0;
 691
 692         for (i = 0; i < sbi->segs_per_sec; i++)
 693                 do_garbage_collect(sbi, segno + i, &ilist, gc_type);
 694
 695         if (gc_type == FG_GC) {
 696                 sbi->cur_victim_sec = NULL_SEGNO;
 697                 nfree++;
 698                 WARN_ON(get_valid_blocks(sbi, segno, sbi->segs_per_sec));
 699         }
 700
 701         if (has_not_enough_free_secs(sbi, nfree))
 702                 goto gc_more;
 703
 704         if (gc_type == FG_GC)
 705                 write_checkpoint(sbi, false);
 706 stop:
 707         mutex_unlock(&sbi->gc_mutex);
 708
 709         put_gc_inode(&ilist);
 710         return ret;
 711 }
 712
 713 void build_gc_manager(struct f2fs_sb_info *sbi)
 714 {
 715         DIRTY_I(sbi)->v_ops = &default_v_ops;
 716 }
 717
 718 int __init create_gc_caches(void)
 719 {
 720         winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
 721                         sizeof(struct inode_entry), NULL);
 722         if (!winode_slab)
 723                 return -ENOMEM;
 724         return 0;
 725 }
 726
 727 void destroy_gc_caches(void)
 728 {
 729         kmem_cache_destroy(winode_slab);
 730 }