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 inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 271 unsigned int segno, struct victim_sel_policy *p) 272 { 273 if (p->alloc_mode == SSR) 274 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 275 276 /* alloc_mode == LFS */ 277 if (p->gc_mode == GC_GREEDY) 278 return get_valid_blocks(sbi, segno, true); 279 else 280 return get_cb_cost(sbi, segno); 281 } 282 283 static unsigned int count_bits(const unsigned long *addr, 284 unsigned int offset, unsigned int len) 285 { 286 unsigned int end = offset + len, sum = 0; 287 288 while (offset < end) { 289 if (test_bit(offset++, addr)) 290 ++sum; 291 } 292 return sum; 293 } 294 295 /* 296 * This function is called from two paths. 297 * One is garbage collection and the other is SSR segment selection. 298 * When it is called during GC, it just gets a victim segment 299 * and it does not remove it from dirty seglist. 300 * When it is called from SSR segment selection, it finds a segment 301 * which has minimum valid blocks and removes it from dirty seglist. 302 */ 303 static int get_victim_by_default(struct f2fs_sb_info *sbi, 304 unsigned int *result, int gc_type, int type, char alloc_mode) 305 { 306 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 307 struct sit_info *sm = SIT_I(sbi); 308 struct victim_sel_policy p; 309 unsigned int secno, last_victim; 310 unsigned int last_segment = MAIN_SEGS(sbi); 311 unsigned int nsearched = 0; 312 313 mutex_lock(&dirty_i->seglist_lock); 314 315 p.alloc_mode = alloc_mode; 316 select_policy(sbi, gc_type, type, &p); 317 318 p.min_segno = NULL_SEGNO; 319 p.min_cost = get_max_cost(sbi, &p); 320 321 if (*result != NULL_SEGNO) { 322 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) && 323 get_valid_blocks(sbi, *result, false) && 324 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result))) 325 p.min_segno = *result; 326 goto out; 327 } 328 329 if (p.max_search == 0) 330 goto out; 331 332 last_victim = sm->last_victim[p.gc_mode]; 333 if (p.alloc_mode == LFS && gc_type == FG_GC) { 334 p.min_segno = check_bg_victims(sbi); 335 if (p.min_segno != NULL_SEGNO) 336 goto got_it; 337 } 338 339 while (1) { 340 unsigned long cost; 341 unsigned int segno; 342 343 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); 344 if (segno >= last_segment) { 345 if (sm->last_victim[p.gc_mode]) { 346 last_segment = 347 sm->last_victim[p.gc_mode]; 348 sm->last_victim[p.gc_mode] = 0; 349 p.offset = 0; 350 continue; 351 } 352 break; 353 } 354 355 p.offset = segno + p.ofs_unit; 356 if (p.ofs_unit > 1) { 357 p.offset -= segno % p.ofs_unit; 358 nsearched += count_bits(p.dirty_segmap, 359 p.offset - p.ofs_unit, 360 p.ofs_unit); 361 } else { 362 nsearched++; 363 } 364 365 secno = GET_SEC_FROM_SEG(sbi, segno); 366 367 if (sec_usage_check(sbi, secno)) 368 goto next; 369 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 370 goto next; 371 if (gc_type == FG_GC && p.alloc_mode == LFS && 372 no_fggc_candidate(sbi, secno)) 373 goto next; 374 375 cost = get_gc_cost(sbi, segno, &p); 376 377 if (p.min_cost > cost) { 378 p.min_segno = segno; 379 p.min_cost = cost; 380 } 381 next: 382 if (nsearched >= p.max_search) { 383 if (!sm->last_victim[p.gc_mode] && segno <= last_victim) 384 sm->last_victim[p.gc_mode] = last_victim + 1; 385 else 386 sm->last_victim[p.gc_mode] = segno + 1; 387 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi); 388 break; 389 } 390 } 391 if (p.min_segno != NULL_SEGNO) { 392 got_it: 393 if (p.alloc_mode == LFS) { 394 secno = GET_SEC_FROM_SEG(sbi, p.min_segno); 395 if (gc_type == FG_GC) 396 sbi->cur_victim_sec = secno; 397 else 398 set_bit(secno, dirty_i->victim_secmap); 399 } 400 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 401 402 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 403 sbi->cur_victim_sec, 404 prefree_segments(sbi), free_segments(sbi)); 405 } 406 out: 407 mutex_unlock(&dirty_i->seglist_lock); 408 409 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 410 } 411 412 static const struct victim_selection default_v_ops = { 413 .get_victim = get_victim_by_default, 414 }; 415 416 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 417 { 418 struct inode_entry *ie; 419 420 ie = radix_tree_lookup(&gc_list->iroot, ino); 421 if (ie) 422 return ie->inode; 423 return NULL; 424 } 425 426 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 427 { 428 struct inode_entry *new_ie; 429 430 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 431 iput(inode); 432 return; 433 } 434 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); 435 new_ie->inode = inode; 436 437 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 438 list_add_tail(&new_ie->list, &gc_list->ilist); 439 } 440 441 static void put_gc_inode(struct gc_inode_list *gc_list) 442 { 443 struct inode_entry *ie, *next_ie; 444 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 445 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 446 iput(ie->inode); 447 list_del(&ie->list); 448 kmem_cache_free(inode_entry_slab, ie); 449 } 450 } 451 452 static int check_valid_map(struct f2fs_sb_info *sbi, 453 unsigned int segno, int offset) 454 { 455 struct sit_info *sit_i = SIT_I(sbi); 456 struct seg_entry *sentry; 457 int ret; 458 459 down_read(&sit_i->sentry_lock); 460 sentry = get_seg_entry(sbi, segno); 461 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 462 up_read(&sit_i->sentry_lock); 463 return ret; 464 } 465 466 /* 467 * This function compares node address got in summary with that in NAT. 468 * On validity, copy that node with cold status, otherwise (invalid node) 469 * ignore that. 470 */ 471 static void gc_node_segment(struct f2fs_sb_info *sbi, 472 struct f2fs_summary *sum, unsigned int segno, int gc_type) 473 { 474 struct f2fs_summary *entry; 475 block_t start_addr; 476 int off; 477 int phase = 0; 478 479 start_addr = START_BLOCK(sbi, segno); 480 481 next_step: 482 entry = sum; 483 484 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 485 nid_t nid = le32_to_cpu(entry->nid); 486 struct page *node_page; 487 struct node_info ni; 488 489 /* stop BG_GC if there is not enough free sections. */ 490 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 491 return; 492 493 if (check_valid_map(sbi, segno, off) == 0) 494 continue; 495 496 if (phase == 0) { 497 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 498 META_NAT, true); 499 continue; 500 } 501 502 if (phase == 1) { 503 ra_node_page(sbi, nid); 504 continue; 505 } 506 507 /* phase == 2 */ 508 node_page = get_node_page(sbi, nid); 509 if (IS_ERR(node_page)) 510 continue; 511 512 /* block may become invalid during get_node_page */ 513 if (check_valid_map(sbi, segno, off) == 0) { 514 f2fs_put_page(node_page, 1); 515 continue; 516 } 517 518 get_node_info(sbi, nid, &ni); 519 if (ni.blk_addr != start_addr + off) { 520 f2fs_put_page(node_page, 1); 521 continue; 522 } 523 524 move_node_page(node_page, gc_type); 525 stat_inc_node_blk_count(sbi, 1, gc_type); 526 } 527 528 if (++phase < 3) 529 goto next_step; 530 } 531 532 /* 533 * Calculate start block index indicating the given node offset. 534 * Be careful, caller should give this node offset only indicating direct node 535 * blocks. If any node offsets, which point the other types of node blocks such 536 * as indirect or double indirect node blocks, are given, it must be a caller's 537 * bug. 538 */ 539 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode) 540 { 541 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 542 unsigned int bidx; 543 544 if (node_ofs == 0) 545 return 0; 546 547 if (node_ofs <= 2) { 548 bidx = node_ofs - 1; 549 } else if (node_ofs <= indirect_blks) { 550 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 551 bidx = node_ofs - 2 - dec; 552 } else { 553 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 554 bidx = node_ofs - 5 - dec; 555 } 556 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode); 557 } 558 559 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 560 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 561 { 562 struct page *node_page; 563 nid_t nid; 564 unsigned int ofs_in_node; 565 block_t source_blkaddr; 566 567 nid = le32_to_cpu(sum->nid); 568 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 569 570 node_page = get_node_page(sbi, nid); 571 if (IS_ERR(node_page)) 572 return false; 573 574 get_node_info(sbi, nid, dni); 575 576 if (sum->version != dni->version) { 577 f2fs_msg(sbi->sb, KERN_WARNING, 578 "%s: valid data with mismatched node version.", 579 __func__); 580 set_sbi_flag(sbi, SBI_NEED_FSCK); 581 } 582 583 *nofs = ofs_of_node(node_page); 584 source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); 585 f2fs_put_page(node_page, 1); 586 587 if (source_blkaddr != blkaddr) 588 return false; 589 return true; 590 } 591 592 /* 593 * Move data block via META_MAPPING while keeping locked data page. 594 * This can be used to move blocks, aka LBAs, directly on disk. 595 */ 596 static void move_data_block(struct inode *inode, block_t bidx, 597 unsigned int segno, int off) 598 { 599 struct f2fs_io_info fio = { 600 .sbi = F2FS_I_SB(inode), 601 .ino = inode->i_ino, 602 .type = DATA, 603 .temp = COLD, 604 .op = REQ_OP_READ, 605 .op_flags = 0, 606 .encrypted_page = NULL, 607 .in_list = false, 608 }; 609 struct dnode_of_data dn; 610 struct f2fs_summary sum; 611 struct node_info ni; 612 struct page *page; 613 block_t newaddr; 614 int err; 615 616 /* do not read out */ 617 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); 618 if (!page) 619 return; 620 621 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) 622 goto out; 623 624 if (f2fs_is_atomic_file(inode)) 625 goto out; 626 627 if (f2fs_is_pinned_file(inode)) { 628 f2fs_pin_file_control(inode, true); 629 goto out; 630 } 631 632 set_new_dnode(&dn, inode, NULL, NULL, 0); 633 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 634 if (err) 635 goto out; 636 637 if (unlikely(dn.data_blkaddr == NULL_ADDR)) { 638 ClearPageUptodate(page); 639 goto put_out; 640 } 641 642 /* 643 * don't cache encrypted data into meta inode until previous dirty 644 * data were writebacked to avoid racing between GC and flush. 645 */ 646 f2fs_wait_on_page_writeback(page, DATA, true); 647 648 get_node_info(fio.sbi, dn.nid, &ni); 649 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 650 651 /* read page */ 652 fio.page = page; 653 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; 654 655 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, 656 &sum, CURSEG_COLD_DATA, NULL, false); 657 658 fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi), 659 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS); 660 if (!fio.encrypted_page) { 661 err = -ENOMEM; 662 goto recover_block; 663 } 664 665 err = f2fs_submit_page_bio(&fio); 666 if (err) 667 goto put_page_out; 668 669 /* write page */ 670 lock_page(fio.encrypted_page); 671 672 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { 673 err = -EIO; 674 goto put_page_out; 675 } 676 if (unlikely(!PageUptodate(fio.encrypted_page))) { 677 err = -EIO; 678 goto put_page_out; 679 } 680 681 set_page_dirty(fio.encrypted_page); 682 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true); 683 if (clear_page_dirty_for_io(fio.encrypted_page)) 684 dec_page_count(fio.sbi, F2FS_DIRTY_META); 685 686 set_page_writeback(fio.encrypted_page); 687 688 /* allocate block address */ 689 f2fs_wait_on_page_writeback(dn.node_page, NODE, true); 690 691 fio.op = REQ_OP_WRITE; 692 fio.op_flags = REQ_SYNC; 693 fio.new_blkaddr = newaddr; 694 err = f2fs_submit_page_write(&fio); 695 if (err) { 696 if (PageWriteback(fio.encrypted_page)) 697 end_page_writeback(fio.encrypted_page); 698 goto put_page_out; 699 } 700 701 f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE); 702 703 f2fs_update_data_blkaddr(&dn, newaddr); 704 set_inode_flag(inode, FI_APPEND_WRITE); 705 if (page->index == 0) 706 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN); 707 put_page_out: 708 f2fs_put_page(fio.encrypted_page, 1); 709 recover_block: 710 if (err) 711 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, 712 true, true); 713 put_out: 714 f2fs_put_dnode(&dn); 715 out: 716 f2fs_put_page(page, 1); 717 } 718 719 static void move_data_page(struct inode *inode, block_t bidx, int gc_type, 720 unsigned int segno, int off) 721 { 722 struct page *page; 723 724 page = get_lock_data_page(inode, bidx, true); 725 if (IS_ERR(page)) 726 return; 727 728 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) 729 goto out; 730 731 if (f2fs_is_atomic_file(inode)) 732 goto out; 733 if (f2fs_is_pinned_file(inode)) { 734 if (gc_type == FG_GC) 735 f2fs_pin_file_control(inode, true); 736 goto out; 737 } 738 739 if (gc_type == BG_GC) { 740 if (PageWriteback(page)) 741 goto out; 742 set_page_dirty(page); 743 set_cold_data(page); 744 } else { 745 struct f2fs_io_info fio = { 746 .sbi = F2FS_I_SB(inode), 747 .ino = inode->i_ino, 748 .type = DATA, 749 .temp = COLD, 750 .op = REQ_OP_WRITE, 751 .op_flags = REQ_SYNC, 752 .old_blkaddr = NULL_ADDR, 753 .page = page, 754 .encrypted_page = NULL, 755 .need_lock = LOCK_REQ, 756 .io_type = FS_GC_DATA_IO, 757 }; 758 bool is_dirty = PageDirty(page); 759 int err; 760 761 retry: 762 set_page_dirty(page); 763 f2fs_wait_on_page_writeback(page, DATA, true); 764 if (clear_page_dirty_for_io(page)) { 765 inode_dec_dirty_pages(inode); 766 remove_dirty_inode(inode); 767 } 768 769 set_cold_data(page); 770 771 err = do_write_data_page(&fio); 772 if (err == -ENOMEM && is_dirty) { 773 congestion_wait(BLK_RW_ASYNC, HZ/50); 774 goto retry; 775 } 776 } 777 out: 778 f2fs_put_page(page, 1); 779 } 780 781 /* 782 * This function tries to get parent node of victim data block, and identifies 783 * data block validity. If the block is valid, copy that with cold status and 784 * modify parent node. 785 * If the parent node is not valid or the data block address is different, 786 * the victim data block is ignored. 787 */ 788 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 789 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 790 { 791 struct super_block *sb = sbi->sb; 792 struct f2fs_summary *entry; 793 block_t start_addr; 794 int off; 795 int phase = 0; 796 797 start_addr = START_BLOCK(sbi, segno); 798 799 next_step: 800 entry = sum; 801 802 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 803 struct page *data_page; 804 struct inode *inode; 805 struct node_info dni; /* dnode info for the data */ 806 unsigned int ofs_in_node, nofs; 807 block_t start_bidx; 808 nid_t nid = le32_to_cpu(entry->nid); 809 810 /* stop BG_GC if there is not enough free sections. */ 811 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 812 return; 813 814 if (check_valid_map(sbi, segno, off) == 0) 815 continue; 816 817 if (phase == 0) { 818 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 819 META_NAT, true); 820 continue; 821 } 822 823 if (phase == 1) { 824 ra_node_page(sbi, nid); 825 continue; 826 } 827 828 /* Get an inode by ino with checking validity */ 829 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 830 continue; 831 832 if (phase == 2) { 833 ra_node_page(sbi, dni.ino); 834 continue; 835 } 836 837 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 838 839 if (phase == 3) { 840 inode = f2fs_iget(sb, dni.ino); 841 if (IS_ERR(inode) || is_bad_inode(inode)) 842 continue; 843 844 /* if encrypted inode, let's go phase 3 */ 845 if (f2fs_encrypted_file(inode)) { 846 add_gc_inode(gc_list, inode); 847 continue; 848 } 849 850 if (!down_write_trylock( 851 &F2FS_I(inode)->dio_rwsem[WRITE])) { 852 iput(inode); 853 continue; 854 } 855 856 start_bidx = start_bidx_of_node(nofs, inode); 857 data_page = get_read_data_page(inode, 858 start_bidx + ofs_in_node, REQ_RAHEAD, 859 true); 860 up_write(&F2FS_I(inode)->dio_rwsem[WRITE]); 861 if (IS_ERR(data_page)) { 862 iput(inode); 863 continue; 864 } 865 866 f2fs_put_page(data_page, 0); 867 add_gc_inode(gc_list, inode); 868 continue; 869 } 870 871 /* phase 4 */ 872 inode = find_gc_inode(gc_list, dni.ino); 873 if (inode) { 874 struct f2fs_inode_info *fi = F2FS_I(inode); 875 bool locked = false; 876 877 if (S_ISREG(inode->i_mode)) { 878 if (!down_write_trylock(&fi->dio_rwsem[READ])) 879 continue; 880 if (!down_write_trylock( 881 &fi->dio_rwsem[WRITE])) { 882 up_write(&fi->dio_rwsem[READ]); 883 continue; 884 } 885 locked = true; 886 887 /* wait for all inflight aio data */ 888 inode_dio_wait(inode); 889 } 890 891 start_bidx = start_bidx_of_node(nofs, inode) 892 + ofs_in_node; 893 if (f2fs_encrypted_file(inode)) 894 move_data_block(inode, start_bidx, segno, off); 895 else 896 move_data_page(inode, start_bidx, gc_type, 897 segno, off); 898 899 if (locked) { 900 up_write(&fi->dio_rwsem[WRITE]); 901 up_write(&fi->dio_rwsem[READ]); 902 } 903 904 stat_inc_data_blk_count(sbi, 1, gc_type); 905 } 906 } 907 908 if (++phase < 5) 909 goto next_step; 910 } 911 912 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 913 int gc_type) 914 { 915 struct sit_info *sit_i = SIT_I(sbi); 916 int ret; 917 918 down_write(&sit_i->sentry_lock); 919 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 920 NO_CHECK_TYPE, LFS); 921 up_write(&sit_i->sentry_lock); 922 return ret; 923 } 924 925 static int do_garbage_collect(struct f2fs_sb_info *sbi, 926 unsigned int start_segno, 927 struct gc_inode_list *gc_list, int gc_type) 928 { 929 struct page *sum_page; 930 struct f2fs_summary_block *sum; 931 struct blk_plug plug; 932 unsigned int segno = start_segno; 933 unsigned int end_segno = start_segno + sbi->segs_per_sec; 934 int seg_freed = 0; 935 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ? 936 SUM_TYPE_DATA : SUM_TYPE_NODE; 937 938 /* readahead multi ssa blocks those have contiguous address */ 939 if (sbi->segs_per_sec > 1) 940 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), 941 sbi->segs_per_sec, META_SSA, true); 942 943 /* reference all summary page */ 944 while (segno < end_segno) { 945 sum_page = get_sum_page(sbi, segno++); 946 unlock_page(sum_page); 947 } 948 949 blk_start_plug(&plug); 950 951 for (segno = start_segno; segno < end_segno; segno++) { 952 953 /* find segment summary of victim */ 954 sum_page = find_get_page(META_MAPPING(sbi), 955 GET_SUM_BLOCK(sbi, segno)); 956 f2fs_put_page(sum_page, 0); 957 958 if (get_valid_blocks(sbi, segno, false) == 0 || 959 !PageUptodate(sum_page) || 960 unlikely(f2fs_cp_error(sbi))) 961 goto next; 962 963 sum = page_address(sum_page); 964 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer))); 965 966 /* 967 * this is to avoid deadlock: 968 * - lock_page(sum_page) - f2fs_replace_block 969 * - check_valid_map() - down_write(sentry_lock) 970 * - down_read(sentry_lock) - change_curseg() 971 * - lock_page(sum_page) 972 */ 973 if (type == SUM_TYPE_NODE) 974 gc_node_segment(sbi, sum->entries, segno, gc_type); 975 else 976 gc_data_segment(sbi, sum->entries, gc_list, segno, 977 gc_type); 978 979 stat_inc_seg_count(sbi, type, gc_type); 980 981 if (gc_type == FG_GC && 982 get_valid_blocks(sbi, segno, false) == 0) 983 seg_freed++; 984 next: 985 f2fs_put_page(sum_page, 0); 986 } 987 988 if (gc_type == FG_GC) 989 f2fs_submit_merged_write(sbi, 990 (type == SUM_TYPE_NODE) ? NODE : DATA); 991 992 blk_finish_plug(&plug); 993 994 stat_inc_call_count(sbi->stat_info); 995 996 return seg_freed; 997 } 998 999 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, 1000 bool background, unsigned int segno) 1001 { 1002 int gc_type = sync ? FG_GC : BG_GC; 1003 int sec_freed = 0, seg_freed = 0, total_freed = 0; 1004 int ret = 0; 1005 struct cp_control cpc; 1006 unsigned int init_segno = segno; 1007 struct gc_inode_list gc_list = { 1008 .ilist = LIST_HEAD_INIT(gc_list.ilist), 1009 .iroot = RADIX_TREE_INIT(GFP_NOFS), 1010 }; 1011 1012 trace_f2fs_gc_begin(sbi->sb, sync, background, 1013 get_pages(sbi, F2FS_DIRTY_NODES), 1014 get_pages(sbi, F2FS_DIRTY_DENTS), 1015 get_pages(sbi, F2FS_DIRTY_IMETA), 1016 free_sections(sbi), 1017 free_segments(sbi), 1018 reserved_segments(sbi), 1019 prefree_segments(sbi)); 1020 1021 cpc.reason = __get_cp_reason(sbi); 1022 gc_more: 1023 if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) { 1024 ret = -EINVAL; 1025 goto stop; 1026 } 1027 if (unlikely(f2fs_cp_error(sbi))) { 1028 ret = -EIO; 1029 goto stop; 1030 } 1031 1032 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) { 1033 /* 1034 * For example, if there are many prefree_segments below given 1035 * threshold, we can make them free by checkpoint. Then, we 1036 * secure free segments which doesn't need fggc any more. 1037 */ 1038 if (prefree_segments(sbi)) { 1039 ret = write_checkpoint(sbi, &cpc); 1040 if (ret) 1041 goto stop; 1042 } 1043 if (has_not_enough_free_secs(sbi, 0, 0)) 1044 gc_type = FG_GC; 1045 } 1046 1047 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ 1048 if (gc_type == BG_GC && !background) { 1049 ret = -EINVAL; 1050 goto stop; 1051 } 1052 if (!__get_victim(sbi, &segno, gc_type)) { 1053 ret = -ENODATA; 1054 goto stop; 1055 } 1056 1057 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); 1058 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) 1059 sec_freed++; 1060 total_freed += seg_freed; 1061 1062 if (gc_type == FG_GC) 1063 sbi->cur_victim_sec = NULL_SEGNO; 1064 1065 if (!sync) { 1066 if (has_not_enough_free_secs(sbi, sec_freed, 0)) { 1067 segno = NULL_SEGNO; 1068 goto gc_more; 1069 } 1070 1071 if (gc_type == FG_GC) 1072 ret = write_checkpoint(sbi, &cpc); 1073 } 1074 stop: 1075 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0; 1076 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno; 1077 1078 trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed, 1079 get_pages(sbi, F2FS_DIRTY_NODES), 1080 get_pages(sbi, F2FS_DIRTY_DENTS), 1081 get_pages(sbi, F2FS_DIRTY_IMETA), 1082 free_sections(sbi), 1083 free_segments(sbi), 1084 reserved_segments(sbi), 1085 prefree_segments(sbi)); 1086 1087 mutex_unlock(&sbi->gc_mutex); 1088 1089 put_gc_inode(&gc_list); 1090 1091 if (sync) 1092 ret = sec_freed ? 0 : -EAGAIN; 1093 return ret; 1094 } 1095 1096 void build_gc_manager(struct f2fs_sb_info *sbi) 1097 { 1098 u64 main_count, resv_count, ovp_count; 1099 1100 DIRTY_I(sbi)->v_ops = &default_v_ops; 1101 1102 /* threshold of # of valid blocks in a section for victims of FG_GC */ 1103 main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg; 1104 resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg; 1105 ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg; 1106 1107 sbi->fggc_threshold = div64_u64((main_count - ovp_count) * 1108 BLKS_PER_SEC(sbi), (main_count - resv_count)); 1109 sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES; 1110 1111 /* give warm/cold data area from slower device */ 1112 if (sbi->s_ndevs && sbi->segs_per_sec == 1) 1113 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 1114 GET_SEGNO(sbi, FDEV(0).end_blk) + 1; 1115 } 1116