1 // SPDX-License-Identifier: GPL-2.0 2 /* 3 * fs/f2fs/gc.c 4 * 5 * Copyright (c) 2012 Samsung Electronics Co., Ltd. 6 * http://www.samsung.com/ 7 */ 8 #include <linux/fs.h> 9 #include <linux/module.h> 10 #include <linux/backing-dev.h> 11 #include <linux/init.h> 12 #include <linux/f2fs_fs.h> 13 #include <linux/kthread.h> 14 #include <linux/delay.h> 15 #include <linux/freezer.h> 16 17 #include "f2fs.h" 18 #include "node.h" 19 #include "segment.h" 20 #include "gc.h" 21 #include <trace/events/f2fs.h> 22 23 static int gc_thread_func(void *data) 24 { 25 struct f2fs_sb_info *sbi = data; 26 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 27 wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head; 28 unsigned int wait_ms; 29 30 wait_ms = gc_th->min_sleep_time; 31 32 set_freezable(); 33 do { 34 wait_event_interruptible_timeout(*wq, 35 kthread_should_stop() || freezing(current) || 36 gc_th->gc_wake, 37 msecs_to_jiffies(wait_ms)); 38 39 /* give it a try one time */ 40 if (gc_th->gc_wake) 41 gc_th->gc_wake = 0; 42 43 if (try_to_freeze()) { 44 stat_other_skip_bggc_count(sbi); 45 continue; 46 } 47 if (kthread_should_stop()) 48 break; 49 50 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) { 51 increase_sleep_time(gc_th, &wait_ms); 52 stat_other_skip_bggc_count(sbi); 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 stat_other_skip_bggc_count(sbi); 63 continue; 64 } 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 (sbi->gc_mode == GC_URGENT) { 80 wait_ms = gc_th->urgent_sleep_time; 81 mutex_lock(&sbi->gc_mutex); 82 goto do_gc; 83 } 84 85 if (!mutex_trylock(&sbi->gc_mutex)) { 86 stat_other_skip_bggc_count(sbi); 87 goto next; 88 } 89 90 if (!is_idle(sbi, GC_TIME)) { 91 increase_sleep_time(gc_th, &wait_ms); 92 mutex_unlock(&sbi->gc_mutex); 93 stat_io_skip_bggc_count(sbi); 94 goto next; 95 } 96 97 if (has_enough_invalid_blocks(sbi)) 98 decrease_sleep_time(gc_th, &wait_ms); 99 else 100 increase_sleep_time(gc_th, &wait_ms); 101 do_gc: 102 stat_inc_bggc_count(sbi); 103 104 /* if return value is not zero, no victim was selected */ 105 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO)) 106 wait_ms = gc_th->no_gc_sleep_time; 107 108 trace_f2fs_background_gc(sbi->sb, wait_ms, 109 prefree_segments(sbi), free_segments(sbi)); 110 111 /* balancing f2fs's metadata periodically */ 112 f2fs_balance_fs_bg(sbi); 113 next: 114 sb_end_write(sbi->sb); 115 116 } while (!kthread_should_stop()); 117 return 0; 118 } 119 120 int f2fs_start_gc_thread(struct f2fs_sb_info *sbi) 121 { 122 struct f2fs_gc_kthread *gc_th; 123 dev_t dev = sbi->sb->s_bdev->bd_dev; 124 int err = 0; 125 126 gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL); 127 if (!gc_th) { 128 err = -ENOMEM; 129 goto out; 130 } 131 132 gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME; 133 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; 134 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; 135 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; 136 137 gc_th->gc_wake= 0; 138 139 sbi->gc_thread = gc_th; 140 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); 141 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, 142 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); 143 if (IS_ERR(gc_th->f2fs_gc_task)) { 144 err = PTR_ERR(gc_th->f2fs_gc_task); 145 kvfree(gc_th); 146 sbi->gc_thread = NULL; 147 } 148 out: 149 return err; 150 } 151 152 void f2fs_stop_gc_thread(struct f2fs_sb_info *sbi) 153 { 154 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 155 if (!gc_th) 156 return; 157 kthread_stop(gc_th->f2fs_gc_task); 158 kvfree(gc_th); 159 sbi->gc_thread = NULL; 160 } 161 162 static int select_gc_type(struct f2fs_sb_info *sbi, int gc_type) 163 { 164 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; 165 166 switch (sbi->gc_mode) { 167 case GC_IDLE_CB: 168 gc_mode = GC_CB; 169 break; 170 case GC_IDLE_GREEDY: 171 case GC_URGENT: 172 gc_mode = GC_GREEDY; 173 break; 174 } 175 return gc_mode; 176 } 177 178 static void select_policy(struct f2fs_sb_info *sbi, int gc_type, 179 int type, struct victim_sel_policy *p) 180 { 181 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 182 183 if (p->alloc_mode == SSR) { 184 p->gc_mode = GC_GREEDY; 185 p->dirty_segmap = dirty_i->dirty_segmap[type]; 186 p->max_search = dirty_i->nr_dirty[type]; 187 p->ofs_unit = 1; 188 } else { 189 p->gc_mode = select_gc_type(sbi, gc_type); 190 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; 191 p->max_search = dirty_i->nr_dirty[DIRTY]; 192 p->ofs_unit = sbi->segs_per_sec; 193 } 194 195 /* we need to check every dirty segments in the FG_GC case */ 196 if (gc_type != FG_GC && 197 (sbi->gc_mode != GC_URGENT) && 198 p->max_search > sbi->max_victim_search) 199 p->max_search = sbi->max_victim_search; 200 201 /* let's select beginning hot/small space first in no_heap mode*/ 202 if (test_opt(sbi, NOHEAP) && 203 (type == CURSEG_HOT_DATA || IS_NODESEG(type))) 204 p->offset = 0; 205 else 206 p->offset = SIT_I(sbi)->last_victim[p->gc_mode]; 207 } 208 209 static unsigned int get_max_cost(struct f2fs_sb_info *sbi, 210 struct victim_sel_policy *p) 211 { 212 /* SSR allocates in a segment unit */ 213 if (p->alloc_mode == SSR) 214 return sbi->blocks_per_seg; 215 if (p->gc_mode == GC_GREEDY) 216 return 2 * sbi->blocks_per_seg * p->ofs_unit; 217 else if (p->gc_mode == GC_CB) 218 return UINT_MAX; 219 else /* No other gc_mode */ 220 return 0; 221 } 222 223 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) 224 { 225 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 226 unsigned int secno; 227 228 /* 229 * If the gc_type is FG_GC, we can select victim segments 230 * selected by background GC before. 231 * Those segments guarantee they have small valid blocks. 232 */ 233 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { 234 if (sec_usage_check(sbi, secno)) 235 continue; 236 clear_bit(secno, dirty_i->victim_secmap); 237 return GET_SEG_FROM_SEC(sbi, secno); 238 } 239 return NULL_SEGNO; 240 } 241 242 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) 243 { 244 struct sit_info *sit_i = SIT_I(sbi); 245 unsigned int secno = GET_SEC_FROM_SEG(sbi, segno); 246 unsigned int start = GET_SEG_FROM_SEC(sbi, secno); 247 unsigned long long mtime = 0; 248 unsigned int vblocks; 249 unsigned char age = 0; 250 unsigned char u; 251 unsigned int i; 252 253 for (i = 0; i < sbi->segs_per_sec; i++) 254 mtime += get_seg_entry(sbi, start + i)->mtime; 255 vblocks = get_valid_blocks(sbi, segno, true); 256 257 mtime = div_u64(mtime, sbi->segs_per_sec); 258 vblocks = div_u64(vblocks, sbi->segs_per_sec); 259 260 u = (vblocks * 100) >> sbi->log_blocks_per_seg; 261 262 /* Handle if the system time has changed by the user */ 263 if (mtime < sit_i->min_mtime) 264 sit_i->min_mtime = mtime; 265 if (mtime > sit_i->max_mtime) 266 sit_i->max_mtime = mtime; 267 if (sit_i->max_mtime != sit_i->min_mtime) 268 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), 269 sit_i->max_mtime - sit_i->min_mtime); 270 271 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); 272 } 273 274 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 275 unsigned int segno, struct victim_sel_policy *p) 276 { 277 if (p->alloc_mode == SSR) 278 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 279 280 /* alloc_mode == LFS */ 281 if (p->gc_mode == GC_GREEDY) 282 return get_valid_blocks(sbi, segno, true); 283 else 284 return get_cb_cost(sbi, segno); 285 } 286 287 static unsigned int count_bits(const unsigned long *addr, 288 unsigned int offset, unsigned int len) 289 { 290 unsigned int end = offset + len, sum = 0; 291 292 while (offset < end) { 293 if (test_bit(offset++, addr)) 294 ++sum; 295 } 296 return sum; 297 } 298 299 /* 300 * This function is called from two paths. 301 * One is garbage collection and the other is SSR segment selection. 302 * When it is called during GC, it just gets a victim segment 303 * and it does not remove it from dirty seglist. 304 * When it is called from SSR segment selection, it finds a segment 305 * which has minimum valid blocks and removes it from dirty seglist. 306 */ 307 static int get_victim_by_default(struct f2fs_sb_info *sbi, 308 unsigned int *result, int gc_type, int type, char alloc_mode) 309 { 310 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 311 struct sit_info *sm = SIT_I(sbi); 312 struct victim_sel_policy p; 313 unsigned int secno, last_victim; 314 unsigned int last_segment = MAIN_SEGS(sbi); 315 unsigned int nsearched = 0; 316 317 mutex_lock(&dirty_i->seglist_lock); 318 319 p.alloc_mode = alloc_mode; 320 select_policy(sbi, gc_type, type, &p); 321 322 p.min_segno = NULL_SEGNO; 323 p.min_cost = get_max_cost(sbi, &p); 324 325 if (*result != NULL_SEGNO) { 326 if (get_valid_blocks(sbi, *result, false) && 327 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result))) 328 p.min_segno = *result; 329 goto out; 330 } 331 332 if (p.max_search == 0) 333 goto out; 334 335 if (__is_large_section(sbi) && p.alloc_mode == LFS) { 336 if (sbi->next_victim_seg[BG_GC] != NULL_SEGNO) { 337 p.min_segno = sbi->next_victim_seg[BG_GC]; 338 *result = p.min_segno; 339 sbi->next_victim_seg[BG_GC] = NULL_SEGNO; 340 goto got_result; 341 } 342 if (gc_type == FG_GC && 343 sbi->next_victim_seg[FG_GC] != NULL_SEGNO) { 344 p.min_segno = sbi->next_victim_seg[FG_GC]; 345 *result = p.min_segno; 346 sbi->next_victim_seg[FG_GC] = NULL_SEGNO; 347 goto got_result; 348 } 349 } 350 351 last_victim = sm->last_victim[p.gc_mode]; 352 if (p.alloc_mode == LFS && gc_type == FG_GC) { 353 p.min_segno = check_bg_victims(sbi); 354 if (p.min_segno != NULL_SEGNO) 355 goto got_it; 356 } 357 358 while (1) { 359 unsigned long cost; 360 unsigned int segno; 361 362 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); 363 if (segno >= last_segment) { 364 if (sm->last_victim[p.gc_mode]) { 365 last_segment = 366 sm->last_victim[p.gc_mode]; 367 sm->last_victim[p.gc_mode] = 0; 368 p.offset = 0; 369 continue; 370 } 371 break; 372 } 373 374 p.offset = segno + p.ofs_unit; 375 if (p.ofs_unit > 1) { 376 p.offset -= segno % p.ofs_unit; 377 nsearched += count_bits(p.dirty_segmap, 378 p.offset - p.ofs_unit, 379 p.ofs_unit); 380 } else { 381 nsearched++; 382 } 383 384 secno = GET_SEC_FROM_SEG(sbi, segno); 385 386 if (sec_usage_check(sbi, secno)) 387 goto next; 388 /* Don't touch checkpointed data */ 389 if (unlikely(is_sbi_flag_set(sbi, SBI_CP_DISABLED) && 390 get_ckpt_valid_blocks(sbi, segno))) 391 goto next; 392 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 393 goto next; 394 395 cost = get_gc_cost(sbi, segno, &p); 396 397 if (p.min_cost > cost) { 398 p.min_segno = segno; 399 p.min_cost = cost; 400 } 401 next: 402 if (nsearched >= p.max_search) { 403 if (!sm->last_victim[p.gc_mode] && segno <= last_victim) 404 sm->last_victim[p.gc_mode] = last_victim + 1; 405 else 406 sm->last_victim[p.gc_mode] = segno + 1; 407 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi); 408 break; 409 } 410 } 411 if (p.min_segno != NULL_SEGNO) { 412 got_it: 413 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 414 got_result: 415 if (p.alloc_mode == LFS) { 416 secno = GET_SEC_FROM_SEG(sbi, p.min_segno); 417 if (gc_type == FG_GC) 418 sbi->cur_victim_sec = secno; 419 else 420 set_bit(secno, dirty_i->victim_secmap); 421 } 422 423 } 424 out: 425 if (p.min_segno != NULL_SEGNO) 426 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 427 sbi->cur_victim_sec, 428 prefree_segments(sbi), free_segments(sbi)); 429 mutex_unlock(&dirty_i->seglist_lock); 430 431 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 432 } 433 434 static const struct victim_selection default_v_ops = { 435 .get_victim = get_victim_by_default, 436 }; 437 438 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 439 { 440 struct inode_entry *ie; 441 442 ie = radix_tree_lookup(&gc_list->iroot, ino); 443 if (ie) 444 return ie->inode; 445 return NULL; 446 } 447 448 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 449 { 450 struct inode_entry *new_ie; 451 452 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 453 iput(inode); 454 return; 455 } 456 new_ie = f2fs_kmem_cache_alloc(f2fs_inode_entry_slab, GFP_NOFS); 457 new_ie->inode = inode; 458 459 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 460 list_add_tail(&new_ie->list, &gc_list->ilist); 461 } 462 463 static void put_gc_inode(struct gc_inode_list *gc_list) 464 { 465 struct inode_entry *ie, *next_ie; 466 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 467 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 468 iput(ie->inode); 469 list_del(&ie->list); 470 kmem_cache_free(f2fs_inode_entry_slab, ie); 471 } 472 } 473 474 static int check_valid_map(struct f2fs_sb_info *sbi, 475 unsigned int segno, int offset) 476 { 477 struct sit_info *sit_i = SIT_I(sbi); 478 struct seg_entry *sentry; 479 int ret; 480 481 down_read(&sit_i->sentry_lock); 482 sentry = get_seg_entry(sbi, segno); 483 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 484 up_read(&sit_i->sentry_lock); 485 return ret; 486 } 487 488 /* 489 * This function compares node address got in summary with that in NAT. 490 * On validity, copy that node with cold status, otherwise (invalid node) 491 * ignore that. 492 */ 493 static int gc_node_segment(struct f2fs_sb_info *sbi, 494 struct f2fs_summary *sum, unsigned int segno, int gc_type) 495 { 496 struct f2fs_summary *entry; 497 block_t start_addr; 498 int off; 499 int phase = 0; 500 bool fggc = (gc_type == FG_GC); 501 int submitted = 0; 502 503 start_addr = START_BLOCK(sbi, segno); 504 505 next_step: 506 entry = sum; 507 508 if (fggc && phase == 2) 509 atomic_inc(&sbi->wb_sync_req[NODE]); 510 511 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 512 nid_t nid = le32_to_cpu(entry->nid); 513 struct page *node_page; 514 struct node_info ni; 515 int err; 516 517 /* stop BG_GC if there is not enough free sections. */ 518 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 519 return submitted; 520 521 if (check_valid_map(sbi, segno, off) == 0) 522 continue; 523 524 if (phase == 0) { 525 f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 526 META_NAT, true); 527 continue; 528 } 529 530 if (phase == 1) { 531 f2fs_ra_node_page(sbi, nid); 532 continue; 533 } 534 535 /* phase == 2 */ 536 node_page = f2fs_get_node_page(sbi, nid); 537 if (IS_ERR(node_page)) 538 continue; 539 540 /* block may become invalid during f2fs_get_node_page */ 541 if (check_valid_map(sbi, segno, off) == 0) { 542 f2fs_put_page(node_page, 1); 543 continue; 544 } 545 546 if (f2fs_get_node_info(sbi, nid, &ni)) { 547 f2fs_put_page(node_page, 1); 548 continue; 549 } 550 551 if (ni.blk_addr != start_addr + off) { 552 f2fs_put_page(node_page, 1); 553 continue; 554 } 555 556 err = f2fs_move_node_page(node_page, gc_type); 557 if (!err && gc_type == FG_GC) 558 submitted++; 559 stat_inc_node_blk_count(sbi, 1, gc_type); 560 } 561 562 if (++phase < 3) 563 goto next_step; 564 565 if (fggc) 566 atomic_dec(&sbi->wb_sync_req[NODE]); 567 return submitted; 568 } 569 570 /* 571 * Calculate start block index indicating the given node offset. 572 * Be careful, caller should give this node offset only indicating direct node 573 * blocks. If any node offsets, which point the other types of node blocks such 574 * as indirect or double indirect node blocks, are given, it must be a caller's 575 * bug. 576 */ 577 block_t f2fs_start_bidx_of_node(unsigned int node_ofs, struct inode *inode) 578 { 579 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 580 unsigned int bidx; 581 582 if (node_ofs == 0) 583 return 0; 584 585 if (node_ofs <= 2) { 586 bidx = node_ofs - 1; 587 } else if (node_ofs <= indirect_blks) { 588 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 589 bidx = node_ofs - 2 - dec; 590 } else { 591 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 592 bidx = node_ofs - 5 - dec; 593 } 594 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode); 595 } 596 597 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 598 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 599 { 600 struct page *node_page; 601 nid_t nid; 602 unsigned int ofs_in_node; 603 block_t source_blkaddr; 604 605 nid = le32_to_cpu(sum->nid); 606 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 607 608 node_page = f2fs_get_node_page(sbi, nid); 609 if (IS_ERR(node_page)) 610 return false; 611 612 if (f2fs_get_node_info(sbi, nid, dni)) { 613 f2fs_put_page(node_page, 1); 614 return false; 615 } 616 617 if (sum->version != dni->version) { 618 f2fs_msg(sbi->sb, KERN_WARNING, 619 "%s: valid data with mismatched node version.", 620 __func__); 621 set_sbi_flag(sbi, SBI_NEED_FSCK); 622 } 623 624 *nofs = ofs_of_node(node_page); 625 source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node); 626 f2fs_put_page(node_page, 1); 627 628 if (source_blkaddr != blkaddr) 629 return false; 630 return true; 631 } 632 633 static int ra_data_block(struct inode *inode, pgoff_t index) 634 { 635 struct f2fs_sb_info *sbi = F2FS_I_SB(inode); 636 struct address_space *mapping = inode->i_mapping; 637 struct dnode_of_data dn; 638 struct page *page; 639 struct extent_info ei = {0, 0, 0}; 640 struct f2fs_io_info fio = { 641 .sbi = sbi, 642 .ino = inode->i_ino, 643 .type = DATA, 644 .temp = COLD, 645 .op = REQ_OP_READ, 646 .op_flags = 0, 647 .encrypted_page = NULL, 648 .in_list = false, 649 .retry = false, 650 }; 651 int err; 652 653 page = f2fs_grab_cache_page(mapping, index, true); 654 if (!page) 655 return -ENOMEM; 656 657 if (f2fs_lookup_extent_cache(inode, index, &ei)) { 658 dn.data_blkaddr = ei.blk + index - ei.fofs; 659 goto got_it; 660 } 661 662 set_new_dnode(&dn, inode, NULL, NULL, 0); 663 err = f2fs_get_dnode_of_data(&dn, index, LOOKUP_NODE); 664 if (err) 665 goto put_page; 666 f2fs_put_dnode(&dn); 667 668 if (unlikely(!f2fs_is_valid_blkaddr(sbi, dn.data_blkaddr, 669 DATA_GENERIC))) { 670 err = -EFAULT; 671 goto put_page; 672 } 673 got_it: 674 /* read page */ 675 fio.page = page; 676 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; 677 678 /* 679 * don't cache encrypted data into meta inode until previous dirty 680 * data were writebacked to avoid racing between GC and flush. 681 */ 682 f2fs_wait_on_page_writeback(page, DATA, true, true); 683 684 f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); 685 686 fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(sbi), 687 dn.data_blkaddr, 688 FGP_LOCK | FGP_CREAT, GFP_NOFS); 689 if (!fio.encrypted_page) { 690 err = -ENOMEM; 691 goto put_page; 692 } 693 694 err = f2fs_submit_page_bio(&fio); 695 if (err) 696 goto put_encrypted_page; 697 f2fs_put_page(fio.encrypted_page, 0); 698 f2fs_put_page(page, 1); 699 return 0; 700 put_encrypted_page: 701 f2fs_put_page(fio.encrypted_page, 1); 702 put_page: 703 f2fs_put_page(page, 1); 704 return err; 705 } 706 707 /* 708 * Move data block via META_MAPPING while keeping locked data page. 709 * This can be used to move blocks, aka LBAs, directly on disk. 710 */ 711 static int move_data_block(struct inode *inode, block_t bidx, 712 int gc_type, unsigned int segno, int off) 713 { 714 struct f2fs_io_info fio = { 715 .sbi = F2FS_I_SB(inode), 716 .ino = inode->i_ino, 717 .type = DATA, 718 .temp = COLD, 719 .op = REQ_OP_READ, 720 .op_flags = 0, 721 .encrypted_page = NULL, 722 .in_list = false, 723 .retry = false, 724 }; 725 struct dnode_of_data dn; 726 struct f2fs_summary sum; 727 struct node_info ni; 728 struct page *page, *mpage; 729 block_t newaddr; 730 int err = 0; 731 bool lfs_mode = test_opt(fio.sbi, LFS); 732 733 /* do not read out */ 734 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); 735 if (!page) 736 return -ENOMEM; 737 738 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) { 739 err = -ENOENT; 740 goto out; 741 } 742 743 if (f2fs_is_atomic_file(inode)) { 744 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++; 745 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++; 746 err = -EAGAIN; 747 goto out; 748 } 749 750 if (f2fs_is_pinned_file(inode)) { 751 f2fs_pin_file_control(inode, true); 752 err = -EAGAIN; 753 goto out; 754 } 755 756 set_new_dnode(&dn, inode, NULL, NULL, 0); 757 err = f2fs_get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 758 if (err) 759 goto out; 760 761 if (unlikely(dn.data_blkaddr == NULL_ADDR)) { 762 ClearPageUptodate(page); 763 err = -ENOENT; 764 goto put_out; 765 } 766 767 /* 768 * don't cache encrypted data into meta inode until previous dirty 769 * data were writebacked to avoid racing between GC and flush. 770 */ 771 f2fs_wait_on_page_writeback(page, DATA, true, true); 772 773 f2fs_wait_on_block_writeback(inode, dn.data_blkaddr); 774 775 err = f2fs_get_node_info(fio.sbi, dn.nid, &ni); 776 if (err) 777 goto put_out; 778 779 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 780 781 /* read page */ 782 fio.page = page; 783 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; 784 785 if (lfs_mode) 786 down_write(&fio.sbi->io_order_lock); 787 788 f2fs_allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, 789 &sum, CURSEG_COLD_DATA, NULL, false); 790 791 fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi), 792 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS); 793 if (!fio.encrypted_page) { 794 err = -ENOMEM; 795 goto recover_block; 796 } 797 798 mpage = f2fs_pagecache_get_page(META_MAPPING(fio.sbi), 799 fio.old_blkaddr, FGP_LOCK, GFP_NOFS); 800 if (mpage) { 801 bool updated = false; 802 803 if (PageUptodate(mpage)) { 804 memcpy(page_address(fio.encrypted_page), 805 page_address(mpage), PAGE_SIZE); 806 updated = true; 807 } 808 f2fs_put_page(mpage, 1); 809 invalidate_mapping_pages(META_MAPPING(fio.sbi), 810 fio.old_blkaddr, fio.old_blkaddr); 811 if (updated) 812 goto write_page; 813 } 814 815 err = f2fs_submit_page_bio(&fio); 816 if (err) 817 goto put_page_out; 818 819 /* write page */ 820 lock_page(fio.encrypted_page); 821 822 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { 823 err = -EIO; 824 goto put_page_out; 825 } 826 if (unlikely(!PageUptodate(fio.encrypted_page))) { 827 err = -EIO; 828 goto put_page_out; 829 } 830 831 write_page: 832 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true, true); 833 set_page_dirty(fio.encrypted_page); 834 if (clear_page_dirty_for_io(fio.encrypted_page)) 835 dec_page_count(fio.sbi, F2FS_DIRTY_META); 836 837 set_page_writeback(fio.encrypted_page); 838 ClearPageError(page); 839 840 /* allocate block address */ 841 f2fs_wait_on_page_writeback(dn.node_page, NODE, true, true); 842 843 fio.op = REQ_OP_WRITE; 844 fio.op_flags = REQ_SYNC; 845 fio.new_blkaddr = newaddr; 846 f2fs_submit_page_write(&fio); 847 if (fio.retry) { 848 err = -EAGAIN; 849 if (PageWriteback(fio.encrypted_page)) 850 end_page_writeback(fio.encrypted_page); 851 goto put_page_out; 852 } 853 854 f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE); 855 856 f2fs_update_data_blkaddr(&dn, newaddr); 857 set_inode_flag(inode, FI_APPEND_WRITE); 858 if (page->index == 0) 859 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN); 860 put_page_out: 861 f2fs_put_page(fio.encrypted_page, 1); 862 recover_block: 863 if (lfs_mode) 864 up_write(&fio.sbi->io_order_lock); 865 if (err) 866 f2fs_do_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, 867 true, true); 868 put_out: 869 f2fs_put_dnode(&dn); 870 out: 871 f2fs_put_page(page, 1); 872 return err; 873 } 874 875 static int move_data_page(struct inode *inode, block_t bidx, int gc_type, 876 unsigned int segno, int off) 877 { 878 struct page *page; 879 int err = 0; 880 881 page = f2fs_get_lock_data_page(inode, bidx, true); 882 if (IS_ERR(page)) 883 return PTR_ERR(page); 884 885 if (!check_valid_map(F2FS_I_SB(inode), segno, off)) { 886 err = -ENOENT; 887 goto out; 888 } 889 890 if (f2fs_is_atomic_file(inode)) { 891 F2FS_I(inode)->i_gc_failures[GC_FAILURE_ATOMIC]++; 892 F2FS_I_SB(inode)->skipped_atomic_files[gc_type]++; 893 err = -EAGAIN; 894 goto out; 895 } 896 if (f2fs_is_pinned_file(inode)) { 897 if (gc_type == FG_GC) 898 f2fs_pin_file_control(inode, true); 899 err = -EAGAIN; 900 goto out; 901 } 902 903 if (gc_type == BG_GC) { 904 if (PageWriteback(page)) { 905 err = -EAGAIN; 906 goto out; 907 } 908 set_page_dirty(page); 909 set_cold_data(page); 910 } else { 911 struct f2fs_io_info fio = { 912 .sbi = F2FS_I_SB(inode), 913 .ino = inode->i_ino, 914 .type = DATA, 915 .temp = COLD, 916 .op = REQ_OP_WRITE, 917 .op_flags = REQ_SYNC, 918 .old_blkaddr = NULL_ADDR, 919 .page = page, 920 .encrypted_page = NULL, 921 .need_lock = LOCK_REQ, 922 .io_type = FS_GC_DATA_IO, 923 }; 924 bool is_dirty = PageDirty(page); 925 926 retry: 927 f2fs_wait_on_page_writeback(page, DATA, true, true); 928 929 set_page_dirty(page); 930 if (clear_page_dirty_for_io(page)) { 931 inode_dec_dirty_pages(inode); 932 f2fs_remove_dirty_inode(inode); 933 } 934 935 set_cold_data(page); 936 937 err = f2fs_do_write_data_page(&fio); 938 if (err) { 939 clear_cold_data(page); 940 if (err == -ENOMEM) { 941 congestion_wait(BLK_RW_ASYNC, HZ/50); 942 goto retry; 943 } 944 if (is_dirty) 945 set_page_dirty(page); 946 } 947 } 948 out: 949 f2fs_put_page(page, 1); 950 return err; 951 } 952 953 /* 954 * This function tries to get parent node of victim data block, and identifies 955 * data block validity. If the block is valid, copy that with cold status and 956 * modify parent node. 957 * If the parent node is not valid or the data block address is different, 958 * the victim data block is ignored. 959 */ 960 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 961 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 962 { 963 struct super_block *sb = sbi->sb; 964 struct f2fs_summary *entry; 965 block_t start_addr; 966 int off; 967 int phase = 0; 968 int submitted = 0; 969 970 start_addr = START_BLOCK(sbi, segno); 971 972 next_step: 973 entry = sum; 974 975 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 976 struct page *data_page; 977 struct inode *inode; 978 struct node_info dni; /* dnode info for the data */ 979 unsigned int ofs_in_node, nofs; 980 block_t start_bidx; 981 nid_t nid = le32_to_cpu(entry->nid); 982 983 /* stop BG_GC if there is not enough free sections. */ 984 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) 985 return submitted; 986 987 if (check_valid_map(sbi, segno, off) == 0) 988 continue; 989 990 if (phase == 0) { 991 f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1, 992 META_NAT, true); 993 continue; 994 } 995 996 if (phase == 1) { 997 f2fs_ra_node_page(sbi, nid); 998 continue; 999 } 1000 1001 /* Get an inode by ino with checking validity */ 1002 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 1003 continue; 1004 1005 if (phase == 2) { 1006 f2fs_ra_node_page(sbi, dni.ino); 1007 continue; 1008 } 1009 1010 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 1011 1012 if (phase == 3) { 1013 inode = f2fs_iget(sb, dni.ino); 1014 if (IS_ERR(inode) || is_bad_inode(inode)) 1015 continue; 1016 1017 if (!down_write_trylock( 1018 &F2FS_I(inode)->i_gc_rwsem[WRITE])) { 1019 iput(inode); 1020 sbi->skipped_gc_rwsem++; 1021 continue; 1022 } 1023 1024 start_bidx = f2fs_start_bidx_of_node(nofs, inode) + 1025 ofs_in_node; 1026 1027 if (f2fs_post_read_required(inode)) { 1028 int err = ra_data_block(inode, start_bidx); 1029 1030 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); 1031 if (err) { 1032 iput(inode); 1033 continue; 1034 } 1035 add_gc_inode(gc_list, inode); 1036 continue; 1037 } 1038 1039 data_page = f2fs_get_read_data_page(inode, 1040 start_bidx, REQ_RAHEAD, true); 1041 up_write(&F2FS_I(inode)->i_gc_rwsem[WRITE]); 1042 if (IS_ERR(data_page)) { 1043 iput(inode); 1044 continue; 1045 } 1046 1047 f2fs_put_page(data_page, 0); 1048 add_gc_inode(gc_list, inode); 1049 continue; 1050 } 1051 1052 /* phase 4 */ 1053 inode = find_gc_inode(gc_list, dni.ino); 1054 if (inode) { 1055 struct f2fs_inode_info *fi = F2FS_I(inode); 1056 bool locked = false; 1057 int err; 1058 1059 if (S_ISREG(inode->i_mode)) { 1060 if (!down_write_trylock(&fi->i_gc_rwsem[READ])) 1061 continue; 1062 if (!down_write_trylock( 1063 &fi->i_gc_rwsem[WRITE])) { 1064 sbi->skipped_gc_rwsem++; 1065 up_write(&fi->i_gc_rwsem[READ]); 1066 continue; 1067 } 1068 locked = true; 1069 1070 /* wait for all inflight aio data */ 1071 inode_dio_wait(inode); 1072 } 1073 1074 start_bidx = f2fs_start_bidx_of_node(nofs, inode) 1075 + ofs_in_node; 1076 if (f2fs_post_read_required(inode)) 1077 err = move_data_block(inode, start_bidx, 1078 gc_type, segno, off); 1079 else 1080 err = move_data_page(inode, start_bidx, gc_type, 1081 segno, off); 1082 1083 if (!err && (gc_type == FG_GC || 1084 f2fs_post_read_required(inode))) 1085 submitted++; 1086 1087 if (locked) { 1088 up_write(&fi->i_gc_rwsem[WRITE]); 1089 up_write(&fi->i_gc_rwsem[READ]); 1090 } 1091 1092 stat_inc_data_blk_count(sbi, 1, gc_type); 1093 } 1094 } 1095 1096 if (++phase < 5) 1097 goto next_step; 1098 1099 return submitted; 1100 } 1101 1102 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 1103 int gc_type) 1104 { 1105 struct sit_info *sit_i = SIT_I(sbi); 1106 int ret; 1107 1108 down_write(&sit_i->sentry_lock); 1109 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 1110 NO_CHECK_TYPE, LFS); 1111 up_write(&sit_i->sentry_lock); 1112 return ret; 1113 } 1114 1115 static int do_garbage_collect(struct f2fs_sb_info *sbi, 1116 unsigned int start_segno, 1117 struct gc_inode_list *gc_list, int gc_type) 1118 { 1119 struct page *sum_page; 1120 struct f2fs_summary_block *sum; 1121 struct blk_plug plug; 1122 unsigned int segno = start_segno; 1123 unsigned int end_segno = start_segno + sbi->segs_per_sec; 1124 int seg_freed = 0, migrated = 0; 1125 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ? 1126 SUM_TYPE_DATA : SUM_TYPE_NODE; 1127 int submitted = 0; 1128 1129 if (__is_large_section(sbi)) 1130 end_segno = rounddown(end_segno, sbi->segs_per_sec); 1131 1132 /* readahead multi ssa blocks those have contiguous address */ 1133 if (__is_large_section(sbi)) 1134 f2fs_ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), 1135 end_segno - segno, META_SSA, true); 1136 1137 /* reference all summary page */ 1138 while (segno < end_segno) { 1139 sum_page = f2fs_get_sum_page(sbi, segno++); 1140 if (IS_ERR(sum_page)) { 1141 int err = PTR_ERR(sum_page); 1142 1143 end_segno = segno - 1; 1144 for (segno = start_segno; segno < end_segno; segno++) { 1145 sum_page = find_get_page(META_MAPPING(sbi), 1146 GET_SUM_BLOCK(sbi, segno)); 1147 f2fs_put_page(sum_page, 0); 1148 f2fs_put_page(sum_page, 0); 1149 } 1150 return err; 1151 } 1152 unlock_page(sum_page); 1153 } 1154 1155 blk_start_plug(&plug); 1156 1157 for (segno = start_segno; segno < end_segno; segno++) { 1158 1159 /* find segment summary of victim */ 1160 sum_page = find_get_page(META_MAPPING(sbi), 1161 GET_SUM_BLOCK(sbi, segno)); 1162 f2fs_put_page(sum_page, 0); 1163 1164 if (get_valid_blocks(sbi, segno, false) == 0) 1165 goto freed; 1166 if (__is_large_section(sbi) && 1167 migrated >= sbi->migration_granularity) 1168 goto skip; 1169 if (!PageUptodate(sum_page) || unlikely(f2fs_cp_error(sbi))) 1170 goto skip; 1171 1172 sum = page_address(sum_page); 1173 if (type != GET_SUM_TYPE((&sum->footer))) { 1174 f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent segment (%u) " 1175 "type [%d, %d] in SSA and SIT", 1176 segno, type, GET_SUM_TYPE((&sum->footer))); 1177 set_sbi_flag(sbi, SBI_NEED_FSCK); 1178 goto skip; 1179 } 1180 1181 /* 1182 * this is to avoid deadlock: 1183 * - lock_page(sum_page) - f2fs_replace_block 1184 * - check_valid_map() - down_write(sentry_lock) 1185 * - down_read(sentry_lock) - change_curseg() 1186 * - lock_page(sum_page) 1187 */ 1188 if (type == SUM_TYPE_NODE) 1189 submitted += gc_node_segment(sbi, sum->entries, segno, 1190 gc_type); 1191 else 1192 submitted += gc_data_segment(sbi, sum->entries, gc_list, 1193 segno, gc_type); 1194 1195 stat_inc_seg_count(sbi, type, gc_type); 1196 1197 freed: 1198 if (gc_type == FG_GC && 1199 get_valid_blocks(sbi, segno, false) == 0) 1200 seg_freed++; 1201 migrated++; 1202 1203 if (__is_large_section(sbi) && segno + 1 < end_segno) 1204 sbi->next_victim_seg[gc_type] = segno + 1; 1205 skip: 1206 f2fs_put_page(sum_page, 0); 1207 } 1208 1209 if (submitted) 1210 f2fs_submit_merged_write(sbi, 1211 (type == SUM_TYPE_NODE) ? NODE : DATA); 1212 1213 blk_finish_plug(&plug); 1214 1215 stat_inc_call_count(sbi->stat_info); 1216 1217 return seg_freed; 1218 } 1219 1220 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync, 1221 bool background, unsigned int segno) 1222 { 1223 int gc_type = sync ? FG_GC : BG_GC; 1224 int sec_freed = 0, seg_freed = 0, total_freed = 0; 1225 int ret = 0; 1226 struct cp_control cpc; 1227 unsigned int init_segno = segno; 1228 struct gc_inode_list gc_list = { 1229 .ilist = LIST_HEAD_INIT(gc_list.ilist), 1230 .iroot = RADIX_TREE_INIT(gc_list.iroot, GFP_NOFS), 1231 }; 1232 unsigned long long last_skipped = sbi->skipped_atomic_files[FG_GC]; 1233 unsigned long long first_skipped; 1234 unsigned int skipped_round = 0, round = 0; 1235 1236 trace_f2fs_gc_begin(sbi->sb, sync, background, 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 cpc.reason = __get_cp_reason(sbi); 1246 sbi->skipped_gc_rwsem = 0; 1247 first_skipped = last_skipped; 1248 gc_more: 1249 if (unlikely(!(sbi->sb->s_flags & SB_ACTIVE))) { 1250 ret = -EINVAL; 1251 goto stop; 1252 } 1253 if (unlikely(f2fs_cp_error(sbi))) { 1254 ret = -EIO; 1255 goto stop; 1256 } 1257 1258 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) { 1259 /* 1260 * For example, if there are many prefree_segments below given 1261 * threshold, we can make them free by checkpoint. Then, we 1262 * secure free segments which doesn't need fggc any more. 1263 */ 1264 if (prefree_segments(sbi) && 1265 !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) { 1266 ret = f2fs_write_checkpoint(sbi, &cpc); 1267 if (ret) 1268 goto stop; 1269 } 1270 if (has_not_enough_free_secs(sbi, 0, 0)) 1271 gc_type = FG_GC; 1272 } 1273 1274 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */ 1275 if (gc_type == BG_GC && !background) { 1276 ret = -EINVAL; 1277 goto stop; 1278 } 1279 if (!__get_victim(sbi, &segno, gc_type)) { 1280 ret = -ENODATA; 1281 goto stop; 1282 } 1283 1284 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); 1285 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) 1286 sec_freed++; 1287 total_freed += seg_freed; 1288 1289 if (gc_type == FG_GC) { 1290 if (sbi->skipped_atomic_files[FG_GC] > last_skipped || 1291 sbi->skipped_gc_rwsem) 1292 skipped_round++; 1293 last_skipped = sbi->skipped_atomic_files[FG_GC]; 1294 round++; 1295 } 1296 1297 if (gc_type == FG_GC) 1298 sbi->cur_victim_sec = NULL_SEGNO; 1299 1300 if (sync) 1301 goto stop; 1302 1303 if (has_not_enough_free_secs(sbi, sec_freed, 0)) { 1304 if (skipped_round <= MAX_SKIP_GC_COUNT || 1305 skipped_round * 2 < round) { 1306 segno = NULL_SEGNO; 1307 goto gc_more; 1308 } 1309 1310 if (first_skipped < last_skipped && 1311 (last_skipped - first_skipped) > 1312 sbi->skipped_gc_rwsem) { 1313 f2fs_drop_inmem_pages_all(sbi, true); 1314 segno = NULL_SEGNO; 1315 goto gc_more; 1316 } 1317 if (gc_type == FG_GC && !is_sbi_flag_set(sbi, SBI_CP_DISABLED)) 1318 ret = f2fs_write_checkpoint(sbi, &cpc); 1319 } 1320 stop: 1321 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0; 1322 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno; 1323 1324 trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed, 1325 get_pages(sbi, F2FS_DIRTY_NODES), 1326 get_pages(sbi, F2FS_DIRTY_DENTS), 1327 get_pages(sbi, F2FS_DIRTY_IMETA), 1328 free_sections(sbi), 1329 free_segments(sbi), 1330 reserved_segments(sbi), 1331 prefree_segments(sbi)); 1332 1333 mutex_unlock(&sbi->gc_mutex); 1334 1335 put_gc_inode(&gc_list); 1336 1337 if (sync && !ret) 1338 ret = sec_freed ? 0 : -EAGAIN; 1339 return ret; 1340 } 1341 1342 void f2fs_build_gc_manager(struct f2fs_sb_info *sbi) 1343 { 1344 DIRTY_I(sbi)->v_ops = &default_v_ops; 1345 1346 sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES; 1347 1348 /* give warm/cold data area from slower device */ 1349 if (sbi->s_ndevs && !__is_large_section(sbi)) 1350 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 1351 GET_SEGNO(sbi, FDEV(0).end_blk) + 1; 1352 } 1353