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 #ifdef CONFIG_F2FS_FAULT_INJECTION 57 if (time_to_inject(sbi, FAULT_CHECKPOINT)) { 58 f2fs_show_injection_info(FAULT_CHECKPOINT); 59 f2fs_stop_checkpoint(sbi, false); 60 } 61 #endif 62 63 if (!sb_start_write_trylock(sbi->sb)) 64 continue; 65 66 /* 67 * [GC triggering condition] 68 * 0. GC is not conducted currently. 69 * 1. There are enough dirty segments. 70 * 2. IO subsystem is idle by checking the # of writeback pages. 71 * 3. IO subsystem is idle by checking the # of requests in 72 * bdev's request list. 73 * 74 * Note) We have to avoid triggering GCs frequently. 75 * Because it is possible that some segments can be 76 * invalidated soon after by user update or deletion. 77 * So, I'd like to wait some time to collect dirty segments. 78 */ 79 if (!mutex_trylock(&sbi->gc_mutex)) 80 goto next; 81 82 if (gc_th->gc_urgent) { 83 wait_ms = gc_th->urgent_sleep_time; 84 goto do_gc; 85 } 86 87 if (!is_idle(sbi)) { 88 increase_sleep_time(gc_th, &wait_ms); 89 mutex_unlock(&sbi->gc_mutex); 90 goto next; 91 } 92 93 if (has_enough_invalid_blocks(sbi)) 94 decrease_sleep_time(gc_th, &wait_ms); 95 else 96 increase_sleep_time(gc_th, &wait_ms); 97 do_gc: 98 stat_inc_bggc_count(sbi); 99 100 /* if return value is not zero, no victim was selected */ 101 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO)) 102 wait_ms = gc_th->no_gc_sleep_time; 103 104 trace_f2fs_background_gc(sbi->sb, wait_ms, 105 prefree_segments(sbi), free_segments(sbi)); 106 107 /* balancing f2fs's metadata periodically */ 108 f2fs_balance_fs_bg(sbi); 109 next: 110 sb_end_write(sbi->sb); 111 112 } while (!kthread_should_stop()); 113 return 0; 114 } 115 116 int start_gc_thread(struct f2fs_sb_info *sbi) 117 { 118 struct f2fs_gc_kthread *gc_th; 119 dev_t dev = sbi->sb->s_bdev->bd_dev; 120 int err = 0; 121 122 gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL); 123 if (!gc_th) { 124 err = -ENOMEM; 125 goto out; 126 } 127 128 gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME; 129 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; 130 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; 131 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; 132 133 gc_th->gc_idle = 0; 134 gc_th->gc_urgent = 0; 135 gc_th->gc_wake= 0; 136 137 sbi->gc_thread = gc_th; 138 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); 139 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, 140 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); 141 if (IS_ERR(gc_th->f2fs_gc_task)) { 142 err = PTR_ERR(gc_th->f2fs_gc_task); 143 kfree(gc_th); 144 sbi->gc_thread = NULL; 145 } 146 out: 147 return err; 148 } 149 150 void stop_gc_thread(struct f2fs_sb_info *sbi) 151 { 152 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 153 if (!gc_th) 154 return; 155 kthread_stop(gc_th->f2fs_gc_task); 156 kfree(gc_th); 157 sbi->gc_thread = NULL; 158 } 159 160 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) 161 { 162 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; 163 164 if (gc_th && gc_th->gc_idle) { 165 if (gc_th->gc_idle == 1) 166 gc_mode = GC_CB; 167 else if (gc_th->gc_idle == 2) 168 gc_mode = GC_GREEDY; 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_thread, 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 && p->max_search > sbi->max_victim_search) 192 p->max_search = sbi->max_victim_search; 193 194 /* let's select beginning hot/small space first */ 195 if (type == CURSEG_HOT_DATA || IS_NODESEG(type)) 196 p->offset = 0; 197 else 198 p->offset = SIT_I(sbi)->last_victim[p->gc_mode]; 199 } 200 201 static unsigned int get_max_cost(struct f2fs_sb_info *sbi, 202 struct victim_sel_policy *p) 203 { 204 /* SSR allocates in a segment unit */ 205 if (p->alloc_mode == SSR) 206 return sbi->blocks_per_seg; 207 if (p->gc_mode == GC_GREEDY) 208 return 2 * sbi->blocks_per_seg * p->ofs_unit; 209 else if (p->gc_mode == GC_CB) 210 return UINT_MAX; 211 else /* No other gc_mode */ 212 return 0; 213 } 214 215 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) 216 { 217 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 218 unsigned int secno; 219 220 /* 221 * If the gc_type is FG_GC, we can select victim segments 222 * selected by background GC before. 223 * Those segments guarantee they have small valid blocks. 224 */ 225 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { 226 if (sec_usage_check(sbi, secno)) 227 continue; 228 229 if (no_fggc_candidate(sbi, secno)) 230 continue; 231 232 clear_bit(secno, dirty_i->victim_secmap); 233 return GET_SEG_FROM_SEC(sbi, secno); 234 } 235 return NULL_SEGNO; 236 } 237 238 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) 239 { 240 struct sit_info *sit_i = SIT_I(sbi); 241 unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); 242 unsigned int start = GET_SEG_FROM_SEC(sbi, secno); 243 unsigned long long mtime = 0; 244 unsigned int vblocks; 245 unsigned char age = 0; 246 unsigned char u; 247 unsigned int i; 248 249 for (i = 0; i < sbi->segs_per_sec; i++) 250 mtime += get_seg_entry(sbi, start + i)->mtime; 251 vblocks = get_valid_blocks(sbi, segno, true); 252 253 mtime = div_u64(mtime, sbi->segs_per_sec); 254 vblocks = div_u64(vblocks, sbi->segs_per_sec); 255 256 u = (vblocks * 100) >> sbi->log_blocks_per_seg; 257 258 /* Handle if the system time has changed by the user */ 259 if (mtime < sit_i->min_mtime) 260 sit_i->min_mtime = mtime; 261 if (mtime > sit_i->max_mtime) 262 sit_i->max_mtime = mtime; 263 if (sit_i->max_mtime != sit_i->min_mtime) 264 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), 265 sit_i->max_mtime - sit_i->min_mtime); 266 267 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); 268 } 269 270 static unsigned int get_greedy_cost(struct f2fs_sb_info *sbi, 271 unsigned int segno) 272 { 273 unsigned int valid_blocks = 274 get_valid_blocks(sbi, segno, true); 275 276 return IS_DATASEG(get_seg_entry(sbi, segno)->type) ? 277 valid_blocks * 2 : valid_blocks; 278 } 279 280 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 281 unsigned int segno, struct victim_sel_policy *p) 282 { 283 if (p->alloc_mode == SSR) 284 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 285 286 /* alloc_mode == LFS */ 287 if (p->gc_mode == GC_GREEDY) 288 return get_greedy_cost(sbi, segno); 289 else 290 return get_cb_cost(sbi, segno); 291 } 292 293 static unsigned int count_bits(const unsigned long *addr, 294 unsigned int offset, unsigned int len) 295 { 296 unsigned int end = offset + len, sum = 0; 297 298 while (offset < end) { 299 if (test_bit(offset++, addr)) 300 ++sum; 301 } 302 return sum; 303 } 304 305 /* 306 * This function is called from two paths. 307 * One is garbage collection and the other is SSR segment selection. 308 * When it is called during GC, it just gets a victim segment 309 * and it does not remove it from dirty seglist. 310 * When it is called from SSR segment selection, it finds a segment 311 * which has minimum valid blocks and removes it from dirty seglist. 312 */ 313 static int get_victim_by_default(struct f2fs_sb_info *sbi, 314 unsigned int *result, int gc_type, int type, char alloc_mode) 315 { 316 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 317 struct sit_info *sm = SIT_I(sbi); 318 struct victim_sel_policy p; 319 unsigned int secno, last_victim; 320 unsigned int last_segment = MAIN_SEGS(sbi); 321 unsigned int nsearched = 0; 322 323 mutex_lock(&dirty_i->seglist_lock); 324 325 p.alloc_mode = alloc_mode; 326 select_policy(sbi, gc_type, type, &p); 327 328 p.min_segno = NULL_SEGNO; 329 p.min_cost = get_max_cost(sbi, &p); 330 331 if (*result != NULL_SEGNO) { 332 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) && 333 get_valid_blocks(sbi, *result, false) && 334 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result))) 335 p.min_segno = *result; 336 goto out; 337 } 338 339 if (p.max_search == 0) 340 goto out; 341 342 last_victim = sm->last_victim[p.gc_mode]; 343 if (p.alloc_mode == LFS && gc_type == FG_GC) { 344 p.min_segno = check_bg_victims(sbi); 345 if (p.min_segno != NULL_SEGNO) 346 goto got_it; 347 } 348 349 while (1) { 350 unsigned long cost; 351 unsigned int segno; 352 353 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); 354 if (segno >= last_segment) { 355 if (sm->last_victim[p.gc_mode]) { 356 last_segment = 357 sm->last_victim[p.gc_mode]; 358 sm->last_victim[p.gc_mode] = 0; 359 p.offset = 0; 360 continue; 361 } 362 break; 363 } 364 365 p.offset = segno + p.ofs_unit; 366 if (p.ofs_unit > 1) { 367 p.offset -= segno % p.ofs_unit; 368 nsearched += count_bits(p.dirty_segmap, 369 p.offset - p.ofs_unit, 370 p.ofs_unit); 371 } else { 372 nsearched++; 373 } 374 375 secno = GET_SEC_FROM_SEG(sbi, segno); 376 377 if (sec_usage_check(sbi, secno)) 378 goto next; 379 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 380 goto next; 381 if (gc_type == FG_GC && p.alloc_mode == LFS && 382 no_fggc_candidate(sbi, secno)) 383 goto next; 384 385 cost = get_gc_cost(sbi, segno, &p); 386 387 if (p.min_cost > cost) { 388 p.min_segno = segno; 389 p.min_cost = cost; 390 } 391 next: 392 if (nsearched >= p.max_search) { 393 if (!sm->last_victim[p.gc_mode] && segno <= last_victim) 394 sm->last_victim[p.gc_mode] = last_victim + 1; 395 else 396 sm->last_victim[p.gc_mode] = segno + 1; 397 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi); 398 break; 399 } 400 } 401 if (p.min_segno != NULL_SEGNO) { 402 got_it: 403 if (p.alloc_mode == LFS) { 404 secno = GET_SEC_FROM_SEG(sbi, p.min_segno); 405 if (gc_type == FG_GC) 406 sbi->cur_victim_sec = secno; 407 else 408 set_bit(secno, dirty_i->victim_secmap); 409 } 410 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 411 412 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 413 sbi->cur_victim_sec, 414 prefree_segments(sbi), free_segments(sbi)); 415 } 416 out: 417 mutex_unlock(&dirty_i->seglist_lock); 418 419 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 420 } 421 422 static const struct victim_selection default_v_ops = { 423 .get_victim = get_victim_by_default, 424 }; 425 426 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 427 { 428 struct inode_entry *ie; 429 430 ie = radix_tree_lookup(&gc_list->iroot, ino); 431 if (ie) 432 return ie->inode; 433 return NULL; 434 } 435 436 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 437 { 438 struct inode_entry *new_ie; 439 440 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 441 iput(inode); 442 return; 443 } 444 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); 445 new_ie->inode = inode; 446 447 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 448 list_add_tail(&new_ie->list, &gc_list->ilist); 449 } 450 451 static void put_gc_inode(struct gc_inode_list *gc_list) 452 { 453 struct inode_entry *ie, *next_ie; 454 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 455 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 456 iput(ie->inode); 457 list_del(&ie->list); 458 kmem_cache_free(inode_entry_slab, ie); 459 } 460 } 461 462 static int check_valid_map(struct f2fs_sb_info *sbi, 463 unsigned int segno, int offset) 464 { 465 struct sit_info *sit_i = SIT_I(sbi); 466 struct seg_entry *sentry; 467 int ret; 468 469 mutex_lock(&sit_i->sentry_lock); 470 sentry = get_seg_entry(sbi, segno); 471 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 472 mutex_unlock(&sit_i->sentry_lock); 473 return ret; 474 } 475 476 /* 477 * This function compares node address got in summary with that in NAT. 478 * On validity, copy that node with cold status, otherwise (invalid node) 479 * ignore that. 480 */ 481 static void gc_node_segment(struct f2fs_sb_info *sbi, 482 struct f2fs_summary *sum, unsigned int segno, int gc_type) 483 { 484 struct f2fs_summary *entry; 485 block_t start_addr; 486 int off; 487 int phase = 0; 488 489 start_addr = START_BLOCK(sbi, segno); 490 491 next_step: 492 entry = sum; 493 494 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 495 nid_t nid = le32_to_cpu(entry->nid); 496 struct page *node_page; 497 struct node_info ni; 498 499 /* stop BG_GC if there is not enough free sections. */ 500 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 501 return; 502 503 if (check_valid_map(sbi, segno, off) == 0) 504 continue; 505 506 if (phase == 0) { 507 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 508 META_NAT, true); 509 continue; 510 } 511 512 if (phase == 1) { 513 ra_node_page(sbi, nid); 514 continue; 515 } 516 517 /* phase == 2 */ 518 node_page = get_node_page(sbi, nid); 519 if (IS_ERR(node_page)) 520 continue; 521 522 /* block may become invalid during get_node_page */ 523 if (check_valid_map(sbi, segno, off) == 0) { 524 f2fs_put_page(node_page, 1); 525 continue; 526 } 527 528 get_node_info(sbi, nid, &ni); 529 if (ni.blk_addr != start_addr + off) { 530 f2fs_put_page(node_page, 1); 531 continue; 532 } 533 534 move_node_page(node_page, gc_type); 535 stat_inc_node_blk_count(sbi, 1, gc_type); 536 } 537 538 if (++phase < 3) 539 goto next_step; 540 } 541 542 /* 543 * Calculate start block index indicating the given node offset. 544 * Be careful, caller should give this node offset only indicating direct node 545 * blocks. If any node offsets, which point the other types of node blocks such 546 * as indirect or double indirect node blocks, are given, it must be a caller's 547 * bug. 548 */ 549 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode) 550 { 551 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 552 unsigned int bidx; 553 554 if (node_ofs == 0) 555 return 0; 556 557 if (node_ofs <= 2) { 558 bidx = node_ofs - 1; 559 } else if (node_ofs <= indirect_blks) { 560 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 561 bidx = node_ofs - 2 - dec; 562 } else { 563 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 564 bidx = node_ofs - 5 - dec; 565 } 566 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode); 567 } 568 569 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 570 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 571 { 572 struct page *node_page; 573 nid_t nid; 574 unsigned int ofs_in_node; 575 block_t source_blkaddr; 576 577 nid = le32_to_cpu(sum->nid); 578 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 579 580 node_page = get_node_page(sbi, nid); 581 if (IS_ERR(node_page)) 582 return false; 583 584 get_node_info(sbi, nid, dni); 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 /* 603 * Move data block via META_MAPPING while keeping locked data page. 604 * This can be used to move blocks, aka LBAs, directly on disk. 605 */ 606 static void move_data_block(struct inode *inode, block_t bidx, 607 unsigned int segno, int off) 608 { 609 struct f2fs_io_info fio = { 610 .sbi = F2FS_I_SB(inode), 611 .type = DATA, 612 .temp = COLD, 613 .op = REQ_OP_READ, 614 .op_flags = 0, 615 .encrypted_page = NULL, 616 .in_list = false, 617 }; 618 struct dnode_of_data dn; 619 struct f2fs_summary sum; 620 struct node_info ni; 621 struct page *page; 622 block_t newaddr; 623 int err; 624 625 /* do not read out */ 626 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); 627 if (!page) 628 return; 629 630 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) 631 goto out; 632 633 if (f2fs_is_atomic_file(inode)) 634 goto out; 635 636 set_new_dnode(&dn, inode, NULL, NULL, 0); 637 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 638 if (err) 639 goto out; 640 641 if (unlikely(dn.data_blkaddr == NULL_ADDR)) { 642 ClearPageUptodate(page); 643 goto put_out; 644 } 645 646 /* 647 * don't cache encrypted data into meta inode until previous dirty 648 * data were writebacked to avoid racing between GC and flush. 649 */ 650 f2fs_wait_on_page_writeback(page, DATA, true); 651 652 get_node_info(fio.sbi, dn.nid, &ni); 653 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 654 655 /* read page */ 656 fio.page = page; 657 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; 658 659 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, 660 &sum, CURSEG_COLD_DATA, NULL, false); 661 662 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr, 663 FGP_LOCK | FGP_CREAT, GFP_NOFS); 664 if (!fio.encrypted_page) { 665 err = -ENOMEM; 666 goto recover_block; 667 } 668 669 err = f2fs_submit_page_bio(&fio); 670 if (err) 671 goto put_page_out; 672 673 /* write page */ 674 lock_page(fio.encrypted_page); 675 676 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { 677 err = -EIO; 678 goto put_page_out; 679 } 680 if (unlikely(!PageUptodate(fio.encrypted_page))) { 681 err = -EIO; 682 goto put_page_out; 683 } 684 685 set_page_dirty(fio.encrypted_page); 686 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true); 687 if (clear_page_dirty_for_io(fio.encrypted_page)) 688 dec_page_count(fio.sbi, F2FS_DIRTY_META); 689 690 set_page_writeback(fio.encrypted_page); 691 692 /* allocate block address */ 693 f2fs_wait_on_page_writeback(dn.node_page, NODE, true); 694 695 fio.op = REQ_OP_WRITE; 696 fio.op_flags = REQ_SYNC; 697 fio.new_blkaddr = newaddr; 698 f2fs_submit_page_write(&fio); 699 700 f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE); 701 702 f2fs_update_data_blkaddr(&dn, newaddr); 703 set_inode_flag(inode, FI_APPEND_WRITE); 704 if (page->index == 0) 705 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN); 706 put_page_out: 707 f2fs_put_page(fio.encrypted_page, 1); 708 recover_block: 709 if (err) 710 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, 711 true, true); 712 put_out: 713 f2fs_put_dnode(&dn); 714 out: 715 f2fs_put_page(page, 1); 716 } 717 718 static void move_data_page(struct inode *inode, block_t bidx, int gc_type, 719 unsigned int segno, int off) 720 { 721 struct page *page; 722 723 page = get_lock_data_page(inode, bidx, true); 724 if (IS_ERR(page)) 725 return; 726 727 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) 728 goto out; 729 730 if (f2fs_is_atomic_file(inode)) 731 goto out; 732 733 if (gc_type == BG_GC) { 734 if (PageWriteback(page)) 735 goto out; 736 set_page_dirty(page); 737 set_cold_data(page); 738 } else { 739 struct f2fs_io_info fio = { 740 .sbi = F2FS_I_SB(inode), 741 .type = DATA, 742 .temp = COLD, 743 .op = REQ_OP_WRITE, 744 .op_flags = REQ_SYNC, 745 .old_blkaddr = NULL_ADDR, 746 .page = page, 747 .encrypted_page = NULL, 748 .need_lock = LOCK_REQ, 749 .io_type = FS_GC_DATA_IO, 750 }; 751 bool is_dirty = PageDirty(page); 752 int err; 753 754 retry: 755 set_page_dirty(page); 756 f2fs_wait_on_page_writeback(page, DATA, true); 757 if (clear_page_dirty_for_io(page)) { 758 inode_dec_dirty_pages(inode); 759 remove_dirty_inode(inode); 760 } 761 762 set_cold_data(page); 763 764 err = do_write_data_page(&fio); 765 if (err == -ENOMEM && is_dirty) { 766 congestion_wait(BLK_RW_ASYNC, HZ/50); 767 goto retry; 768 } 769 } 770 out: 771 f2fs_put_page(page, 1); 772 } 773 774 /* 775 * This function tries to get parent node of victim data block, and identifies 776 * data block validity. If the block is valid, copy that with cold status and 777 * modify parent node. 778 * If the parent node is not valid or the data block address is different, 779 * the victim data block is ignored. 780 */ 781 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 782 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 783 { 784 struct super_block *sb = sbi->sb; 785 struct f2fs_summary *entry; 786 block_t start_addr; 787 int off; 788 int phase = 0; 789 790 start_addr = START_BLOCK(sbi, segno); 791 792 next_step: 793 entry = sum; 794 795 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 796 struct page *data_page; 797 struct inode *inode; 798 struct node_info dni; /* dnode info for the data */ 799 unsigned int ofs_in_node, nofs; 800 block_t start_bidx; 801 nid_t nid = le32_to_cpu(entry->nid); 802 803 /* stop BG_GC if there is not enough free sections. */ 804 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 805 return; 806 807 if (check_valid_map(sbi, segno, off) == 0) 808 continue; 809 810 if (phase == 0) { 811 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 812 META_NAT, true); 813 continue; 814 } 815 816 if (phase == 1) { 817 ra_node_page(sbi, nid); 818 continue; 819 } 820 821 /* Get an inode by ino with checking validity */ 822 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 823 continue; 824 825 if (phase == 2) { 826 ra_node_page(sbi, dni.ino); 827 continue; 828 } 829 830 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 831 832 if (phase == 3) { 833 inode = f2fs_iget(sb, dni.ino); 834 if (IS_ERR(inode) || is_bad_inode(inode)) 835 continue; 836 837 /* if encrypted inode, let's go phase 3 */ 838 if (f2fs_encrypted_file(inode)) { 839 add_gc_inode(gc_list, inode); 840 continue; 841 } 842 843 start_bidx = start_bidx_of_node(nofs, inode); 844 data_page = get_read_data_page(inode, 845 start_bidx + ofs_in_node, REQ_RAHEAD, 846 true); 847 if (IS_ERR(data_page)) { 848 iput(inode); 849 continue; 850 } 851 852 f2fs_put_page(data_page, 0); 853 add_gc_inode(gc_list, inode); 854 continue; 855 } 856 857 /* phase 4 */ 858 inode = find_gc_inode(gc_list, dni.ino); 859 if (inode) { 860 struct f2fs_inode_info *fi = F2FS_I(inode); 861 bool locked = false; 862 863 if (S_ISREG(inode->i_mode)) { 864 if (!down_write_trylock(&fi->dio_rwsem[READ])) 865 continue; 866 if (!down_write_trylock( 867 &fi->dio_rwsem[WRITE])) { 868 up_write(&fi->dio_rwsem[READ]); 869 continue; 870 } 871 locked = true; 872 873 /* wait for all inflight aio data */ 874 inode_dio_wait(inode); 875 } 876 877 start_bidx = start_bidx_of_node(nofs, inode) 878 + ofs_in_node; 879 if (f2fs_encrypted_file(inode)) 880 move_data_block(inode, start_bidx, segno, off); 881 else 882 move_data_page(inode, start_bidx, gc_type, 883 segno, off); 884 885 if (locked) { 886 up_write(&fi->dio_rwsem[WRITE]); 887 up_write(&fi->dio_rwsem[READ]); 888 } 889 890 stat_inc_data_blk_count(sbi, 1, gc_type); 891 } 892 } 893 894 if (++phase < 5) 895 goto next_step; 896 } 897 898 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 899 int gc_type) 900 { 901 struct sit_info *sit_i = SIT_I(sbi); 902 int ret; 903 904 mutex_lock(&sit_i->sentry_lock); 905 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 906 NO_CHECK_TYPE, LFS); 907 mutex_unlock(&sit_i->sentry_lock); 908 return ret; 909 } 910 911 static int do_garbage_collect(struct f2fs_sb_info *sbi, 912 unsigned int start_segno, 913 struct gc_inode_list *gc_list, int gc_type) 914 { 915 struct page *sum_page; 916 struct f2fs_summary_block *sum; 917 struct blk_plug plug; 918 unsigned int segno = start_segno; 919 unsigned int end_segno = start_segno + sbi->segs_per_sec; 920 int seg_freed = 0; 921 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ? 922 SUM_TYPE_DATA : SUM_TYPE_NODE; 923 924 /* readahead multi ssa blocks those have contiguous address */ 925 if (sbi->segs_per_sec > 1) 926 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), 927 sbi->segs_per_sec, META_SSA, true); 928 929 /* reference all summary page */ 930 while (segno < end_segno) { 931 sum_page = get_sum_page(sbi, segno++); 932 unlock_page(sum_page); 933 } 934 935 blk_start_plug(&plug); 936 937 for (segno = start_segno; segno < end_segno; segno++) { 938 939 /* find segment summary of victim */ 940 sum_page = find_get_page(META_MAPPING(sbi), 941 GET_SUM_BLOCK(sbi, segno)); 942 f2fs_put_page(sum_page, 0); 943 944 if (get_valid_blocks(sbi, segno, false) == 0 || 945 !PageUptodate(sum_page) || 946 unlikely(f2fs_cp_error(sbi))) 947 goto next; 948 949 sum = page_address(sum_page); 950 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer))); 951 952 /* 953 * this is to avoid deadlock: 954 * - lock_page(sum_page) - f2fs_replace_block 955 * - check_valid_map() - mutex_lock(sentry_lock) 956 * - mutex_lock(sentry_lock) - change_curseg() 957 * - lock_page(sum_page) 958 */ 959 if (type == SUM_TYPE_NODE) 960 gc_node_segment(sbi, sum->entries, segno, gc_type); 961 else 962 gc_data_segment(sbi, sum->entries, gc_list, segno, 963 gc_type); 964 965 stat_inc_seg_count(sbi, type, gc_type); 966 967 if (gc_type == FG_GC && 968 get_valid_blocks(sbi, segno, false) == 0) 969 seg_freed++; 970 next: 971 f2fs_put_page(sum_page, 0); 972 } 973 974 if (gc_type == FG_GC) 975 f2fs_submit_merged_write(sbi, 976 (type == SUM_TYPE_NODE) ? NODE : DATA); 977 978 blk_finish_plug(&plug); 979 980 stat_inc_call_count(sbi->stat_info); 981 982 return seg_freed; 983 } 984 985 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, 986 bool background, unsigned int segno) 987 { 988 int gc_type = sync ? FG_GC : BG_GC; 989 int sec_freed = 0, seg_freed = 0, total_freed = 0; 990 int ret = 0; 991 struct cp_control cpc; 992 unsigned int init_segno = segno; 993 struct gc_inode_list gc_list = { 994 .ilist = LIST_HEAD_INIT(gc_list.ilist), 995 .iroot = RADIX_TREE_INIT(GFP_NOFS), 996 }; 997 998 trace_f2fs_gc_begin(sbi->sb, sync, background, 999 get_pages(sbi, F2FS_DIRTY_NODES), 1000 get_pages(sbi, F2FS_DIRTY_DENTS), 1001 get_pages(sbi, F2FS_DIRTY_IMETA), 1002 free_sections(sbi), 1003 free_segments(sbi), 1004 reserved_segments(sbi), 1005 prefree_segments(sbi)); 1006 1007 cpc.reason = __get_cp_reason(sbi); 1008 gc_more: 1009 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) { 1010 ret = -EINVAL; 1011 goto stop; 1012 } 1013 if (unlikely(f2fs_cp_error(sbi))) { 1014 ret = -EIO; 1015 goto stop; 1016 } 1017 1018 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) { 1019 /* 1020 * For example, if there are many prefree_segments below given 1021 * threshold, we can make them free by checkpoint. Then, we 1022 * secure free segments which doesn't need fggc any more. 1023 */ 1024 if (prefree_segments(sbi)) { 1025 ret = write_checkpoint(sbi, &cpc); 1026 if (ret) 1027 goto stop; 1028 } 1029 if (has_not_enough_free_secs(sbi, 0, 0)) 1030 gc_type = FG_GC; 1031 } 1032 1033 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ 1034 if (gc_type == BG_GC && !background) { 1035 ret = -EINVAL; 1036 goto stop; 1037 } 1038 if (!__get_victim(sbi, &segno, gc_type)) { 1039 ret = -ENODATA; 1040 goto stop; 1041 } 1042 1043 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); 1044 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) 1045 sec_freed++; 1046 total_freed += seg_freed; 1047 1048 if (gc_type == FG_GC) 1049 sbi->cur_victim_sec = NULL_SEGNO; 1050 1051 if (!sync) { 1052 if (has_not_enough_free_secs(sbi, sec_freed, 0)) { 1053 segno = NULL_SEGNO; 1054 goto gc_more; 1055 } 1056 1057 if (gc_type == FG_GC) 1058 ret = write_checkpoint(sbi, &cpc); 1059 } 1060 stop: 1061 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0; 1062 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno; 1063 1064 trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed, 1065 get_pages(sbi, F2FS_DIRTY_NODES), 1066 get_pages(sbi, F2FS_DIRTY_DENTS), 1067 get_pages(sbi, F2FS_DIRTY_IMETA), 1068 free_sections(sbi), 1069 free_segments(sbi), 1070 reserved_segments(sbi), 1071 prefree_segments(sbi)); 1072 1073 mutex_unlock(&sbi->gc_mutex); 1074 1075 put_gc_inode(&gc_list); 1076 1077 if (sync) 1078 ret = sec_freed ? 0 : -EAGAIN; 1079 return ret; 1080 } 1081 1082 void build_gc_manager(struct f2fs_sb_info *sbi) 1083 { 1084 u64 main_count, resv_count, ovp_count; 1085 1086 DIRTY_I(sbi)->v_ops = &default_v_ops; 1087 1088 /* threshold of # of valid blocks in a section for victims of FG_GC */ 1089 main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg; 1090 resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg; 1091 ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg; 1092 1093 sbi->fggc_threshold = div64_u64((main_count - ovp_count) * 1094 BLKS_PER_SEC(sbi), (main_count - resv_count)); 1095 1096 /* give warm/cold data area from slower device */ 1097 if (sbi->s_ndevs && sbi->segs_per_sec == 1) 1098 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 1099 GET_SEGNO(sbi, FDEV(0).end_blk) + 1; 1100 } 1101