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 long wait_ms; 32 33 wait_ms = gc_th->min_sleep_time; 34 35 do { 36 if (try_to_freeze()) 37 continue; 38 else 39 wait_event_interruptible_timeout(*wq, 40 kthread_should_stop(), 41 msecs_to_jiffies(wait_ms)); 42 if (kthread_should_stop()) 43 break; 44 45 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) { 46 increase_sleep_time(gc_th, &wait_ms); 47 continue; 48 } 49 50 /* 51 * [GC triggering condition] 52 * 0. GC is not conducted currently. 53 * 1. There are enough dirty segments. 54 * 2. IO subsystem is idle by checking the # of writeback pages. 55 * 3. IO subsystem is idle by checking the # of requests in 56 * bdev's request list. 57 * 58 * Note) We have to avoid triggering GCs frequently. 59 * Because it is possible that some segments can be 60 * invalidated soon after by user update or deletion. 61 * So, I'd like to wait some time to collect dirty segments. 62 */ 63 if (!mutex_trylock(&sbi->gc_mutex)) 64 continue; 65 66 if (!is_idle(sbi)) { 67 increase_sleep_time(gc_th, &wait_ms); 68 mutex_unlock(&sbi->gc_mutex); 69 continue; 70 } 71 72 if (has_enough_invalid_blocks(sbi)) 73 decrease_sleep_time(gc_th, &wait_ms); 74 else 75 increase_sleep_time(gc_th, &wait_ms); 76 77 stat_inc_bggc_count(sbi); 78 79 /* if return value is not zero, no victim was selected */ 80 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC))) 81 wait_ms = gc_th->no_gc_sleep_time; 82 83 trace_f2fs_background_gc(sbi->sb, wait_ms, 84 prefree_segments(sbi), free_segments(sbi)); 85 86 /* balancing f2fs's metadata periodically */ 87 f2fs_balance_fs_bg(sbi); 88 89 } while (!kthread_should_stop()); 90 return 0; 91 } 92 93 int start_gc_thread(struct f2fs_sb_info *sbi) 94 { 95 struct f2fs_gc_kthread *gc_th; 96 dev_t dev = sbi->sb->s_bdev->bd_dev; 97 int err = 0; 98 99 gc_th = f2fs_kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL); 100 if (!gc_th) { 101 err = -ENOMEM; 102 goto out; 103 } 104 105 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; 106 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; 107 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; 108 109 gc_th->gc_idle = 0; 110 111 sbi->gc_thread = gc_th; 112 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); 113 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, 114 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); 115 if (IS_ERR(gc_th->f2fs_gc_task)) { 116 err = PTR_ERR(gc_th->f2fs_gc_task); 117 kfree(gc_th); 118 sbi->gc_thread = NULL; 119 } 120 out: 121 return err; 122 } 123 124 void stop_gc_thread(struct f2fs_sb_info *sbi) 125 { 126 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 127 if (!gc_th) 128 return; 129 kthread_stop(gc_th->f2fs_gc_task); 130 kfree(gc_th); 131 sbi->gc_thread = NULL; 132 } 133 134 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) 135 { 136 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; 137 138 if (gc_th && gc_th->gc_idle) { 139 if (gc_th->gc_idle == 1) 140 gc_mode = GC_CB; 141 else if (gc_th->gc_idle == 2) 142 gc_mode = GC_GREEDY; 143 } 144 return gc_mode; 145 } 146 147 static void select_policy(struct f2fs_sb_info *sbi, int gc_type, 148 int type, struct victim_sel_policy *p) 149 { 150 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 151 152 if (p->alloc_mode == SSR) { 153 p->gc_mode = GC_GREEDY; 154 p->dirty_segmap = dirty_i->dirty_segmap[type]; 155 p->max_search = dirty_i->nr_dirty[type]; 156 p->ofs_unit = 1; 157 } else { 158 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type); 159 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; 160 p->max_search = dirty_i->nr_dirty[DIRTY]; 161 p->ofs_unit = sbi->segs_per_sec; 162 } 163 164 if (p->max_search > sbi->max_victim_search) 165 p->max_search = sbi->max_victim_search; 166 167 p->offset = sbi->last_victim[p->gc_mode]; 168 } 169 170 static unsigned int get_max_cost(struct f2fs_sb_info *sbi, 171 struct victim_sel_policy *p) 172 { 173 /* SSR allocates in a segment unit */ 174 if (p->alloc_mode == SSR) 175 return sbi->blocks_per_seg; 176 if (p->gc_mode == GC_GREEDY) 177 return sbi->blocks_per_seg * p->ofs_unit; 178 else if (p->gc_mode == GC_CB) 179 return UINT_MAX; 180 else /* No other gc_mode */ 181 return 0; 182 } 183 184 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) 185 { 186 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 187 unsigned int secno; 188 189 /* 190 * If the gc_type is FG_GC, we can select victim segments 191 * selected by background GC before. 192 * Those segments guarantee they have small valid blocks. 193 */ 194 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { 195 if (sec_usage_check(sbi, secno)) 196 continue; 197 clear_bit(secno, dirty_i->victim_secmap); 198 return secno * sbi->segs_per_sec; 199 } 200 return NULL_SEGNO; 201 } 202 203 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) 204 { 205 struct sit_info *sit_i = SIT_I(sbi); 206 unsigned int secno = GET_SECNO(sbi, segno); 207 unsigned int start = secno * sbi->segs_per_sec; 208 unsigned long long mtime = 0; 209 unsigned int vblocks; 210 unsigned char age = 0; 211 unsigned char u; 212 unsigned int i; 213 214 for (i = 0; i < sbi->segs_per_sec; i++) 215 mtime += get_seg_entry(sbi, start + i)->mtime; 216 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec); 217 218 mtime = div_u64(mtime, sbi->segs_per_sec); 219 vblocks = div_u64(vblocks, sbi->segs_per_sec); 220 221 u = (vblocks * 100) >> sbi->log_blocks_per_seg; 222 223 /* Handle if the system time has changed by the user */ 224 if (mtime < sit_i->min_mtime) 225 sit_i->min_mtime = mtime; 226 if (mtime > sit_i->max_mtime) 227 sit_i->max_mtime = mtime; 228 if (sit_i->max_mtime != sit_i->min_mtime) 229 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), 230 sit_i->max_mtime - sit_i->min_mtime); 231 232 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); 233 } 234 235 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 236 unsigned int segno, struct victim_sel_policy *p) 237 { 238 if (p->alloc_mode == SSR) 239 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 240 241 /* alloc_mode == LFS */ 242 if (p->gc_mode == GC_GREEDY) 243 return get_valid_blocks(sbi, segno, sbi->segs_per_sec); 244 else 245 return get_cb_cost(sbi, segno); 246 } 247 248 static unsigned int count_bits(const unsigned long *addr, 249 unsigned int offset, unsigned int len) 250 { 251 unsigned int end = offset + len, sum = 0; 252 253 while (offset < end) { 254 if (test_bit(offset++, addr)) 255 ++sum; 256 } 257 return sum; 258 } 259 260 /* 261 * This function is called from two paths. 262 * One is garbage collection and the other is SSR segment selection. 263 * When it is called during GC, it just gets a victim segment 264 * and it does not remove it from dirty seglist. 265 * When it is called from SSR segment selection, it finds a segment 266 * which has minimum valid blocks and removes it from dirty seglist. 267 */ 268 static int get_victim_by_default(struct f2fs_sb_info *sbi, 269 unsigned int *result, int gc_type, int type, char alloc_mode) 270 { 271 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 272 struct victim_sel_policy p; 273 unsigned int secno, max_cost, last_victim; 274 unsigned int last_segment = MAIN_SEGS(sbi); 275 unsigned int nsearched = 0; 276 277 mutex_lock(&dirty_i->seglist_lock); 278 279 p.alloc_mode = alloc_mode; 280 select_policy(sbi, gc_type, type, &p); 281 282 p.min_segno = NULL_SEGNO; 283 p.min_cost = max_cost = get_max_cost(sbi, &p); 284 285 if (p.max_search == 0) 286 goto out; 287 288 last_victim = sbi->last_victim[p.gc_mode]; 289 if (p.alloc_mode == LFS && gc_type == FG_GC) { 290 p.min_segno = check_bg_victims(sbi); 291 if (p.min_segno != NULL_SEGNO) 292 goto got_it; 293 } 294 295 while (1) { 296 unsigned long cost; 297 unsigned int segno; 298 299 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); 300 if (segno >= last_segment) { 301 if (sbi->last_victim[p.gc_mode]) { 302 last_segment = sbi->last_victim[p.gc_mode]; 303 sbi->last_victim[p.gc_mode] = 0; 304 p.offset = 0; 305 continue; 306 } 307 break; 308 } 309 310 p.offset = segno + p.ofs_unit; 311 if (p.ofs_unit > 1) { 312 p.offset -= segno % p.ofs_unit; 313 nsearched += count_bits(p.dirty_segmap, 314 p.offset - p.ofs_unit, 315 p.ofs_unit); 316 } else { 317 nsearched++; 318 } 319 320 321 secno = GET_SECNO(sbi, segno); 322 323 if (sec_usage_check(sbi, secno)) 324 goto next; 325 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 326 goto next; 327 328 cost = get_gc_cost(sbi, segno, &p); 329 330 if (p.min_cost > cost) { 331 p.min_segno = segno; 332 p.min_cost = cost; 333 } 334 next: 335 if (nsearched >= p.max_search) { 336 if (!sbi->last_victim[p.gc_mode] && segno <= last_victim) 337 sbi->last_victim[p.gc_mode] = last_victim + 1; 338 else 339 sbi->last_victim[p.gc_mode] = segno + 1; 340 break; 341 } 342 } 343 if (p.min_segno != NULL_SEGNO) { 344 got_it: 345 if (p.alloc_mode == LFS) { 346 secno = GET_SECNO(sbi, p.min_segno); 347 if (gc_type == FG_GC) 348 sbi->cur_victim_sec = secno; 349 else 350 set_bit(secno, dirty_i->victim_secmap); 351 } 352 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 353 354 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 355 sbi->cur_victim_sec, 356 prefree_segments(sbi), free_segments(sbi)); 357 } 358 out: 359 mutex_unlock(&dirty_i->seglist_lock); 360 361 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 362 } 363 364 static const struct victim_selection default_v_ops = { 365 .get_victim = get_victim_by_default, 366 }; 367 368 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 369 { 370 struct inode_entry *ie; 371 372 ie = radix_tree_lookup(&gc_list->iroot, ino); 373 if (ie) 374 return ie->inode; 375 return NULL; 376 } 377 378 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 379 { 380 struct inode_entry *new_ie; 381 382 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 383 iput(inode); 384 return; 385 } 386 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); 387 new_ie->inode = inode; 388 389 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 390 list_add_tail(&new_ie->list, &gc_list->ilist); 391 } 392 393 static void put_gc_inode(struct gc_inode_list *gc_list) 394 { 395 struct inode_entry *ie, *next_ie; 396 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 397 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 398 iput(ie->inode); 399 list_del(&ie->list); 400 kmem_cache_free(inode_entry_slab, ie); 401 } 402 } 403 404 static int check_valid_map(struct f2fs_sb_info *sbi, 405 unsigned int segno, int offset) 406 { 407 struct sit_info *sit_i = SIT_I(sbi); 408 struct seg_entry *sentry; 409 int ret; 410 411 mutex_lock(&sit_i->sentry_lock); 412 sentry = get_seg_entry(sbi, segno); 413 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 414 mutex_unlock(&sit_i->sentry_lock); 415 return ret; 416 } 417 418 /* 419 * This function compares node address got in summary with that in NAT. 420 * On validity, copy that node with cold status, otherwise (invalid node) 421 * ignore that. 422 */ 423 static void gc_node_segment(struct f2fs_sb_info *sbi, 424 struct f2fs_summary *sum, unsigned int segno, int gc_type) 425 { 426 bool initial = true; 427 struct f2fs_summary *entry; 428 block_t start_addr; 429 int off; 430 431 start_addr = START_BLOCK(sbi, segno); 432 433 next_step: 434 entry = sum; 435 436 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 437 nid_t nid = le32_to_cpu(entry->nid); 438 struct page *node_page; 439 struct node_info ni; 440 441 /* stop BG_GC if there is not enough free sections. */ 442 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 443 return; 444 445 if (check_valid_map(sbi, segno, off) == 0) 446 continue; 447 448 if (initial) { 449 ra_node_page(sbi, nid); 450 continue; 451 } 452 node_page = get_node_page(sbi, nid); 453 if (IS_ERR(node_page)) 454 continue; 455 456 /* block may become invalid during get_node_page */ 457 if (check_valid_map(sbi, segno, off) == 0) { 458 f2fs_put_page(node_page, 1); 459 continue; 460 } 461 462 get_node_info(sbi, nid, &ni); 463 if (ni.blk_addr != start_addr + off) { 464 f2fs_put_page(node_page, 1); 465 continue; 466 } 467 468 move_node_page(node_page, gc_type); 469 stat_inc_node_blk_count(sbi, 1, gc_type); 470 } 471 472 if (initial) { 473 initial = false; 474 goto next_step; 475 } 476 } 477 478 /* 479 * Calculate start block index indicating the given node offset. 480 * Be careful, caller should give this node offset only indicating direct node 481 * blocks. If any node offsets, which point the other types of node blocks such 482 * as indirect or double indirect node blocks, are given, it must be a caller's 483 * bug. 484 */ 485 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode) 486 { 487 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 488 unsigned int bidx; 489 490 if (node_ofs == 0) 491 return 0; 492 493 if (node_ofs <= 2) { 494 bidx = node_ofs - 1; 495 } else if (node_ofs <= indirect_blks) { 496 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 497 bidx = node_ofs - 2 - dec; 498 } else { 499 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 500 bidx = node_ofs - 5 - dec; 501 } 502 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode); 503 } 504 505 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 506 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 507 { 508 struct page *node_page; 509 nid_t nid; 510 unsigned int ofs_in_node; 511 block_t source_blkaddr; 512 513 nid = le32_to_cpu(sum->nid); 514 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 515 516 node_page = get_node_page(sbi, nid); 517 if (IS_ERR(node_page)) 518 return false; 519 520 get_node_info(sbi, nid, dni); 521 522 if (sum->version != dni->version) { 523 f2fs_put_page(node_page, 1); 524 return false; 525 } 526 527 *nofs = ofs_of_node(node_page); 528 source_blkaddr = datablock_addr(node_page, ofs_in_node); 529 f2fs_put_page(node_page, 1); 530 531 if (source_blkaddr != blkaddr) 532 return false; 533 return true; 534 } 535 536 static void move_encrypted_block(struct inode *inode, block_t bidx) 537 { 538 struct f2fs_io_info fio = { 539 .sbi = F2FS_I_SB(inode), 540 .type = DATA, 541 .rw = READ_SYNC, 542 .encrypted_page = NULL, 543 }; 544 struct dnode_of_data dn; 545 struct f2fs_summary sum; 546 struct node_info ni; 547 struct page *page; 548 block_t newaddr; 549 int err; 550 551 /* do not read out */ 552 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); 553 if (!page) 554 return; 555 556 set_new_dnode(&dn, inode, NULL, NULL, 0); 557 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 558 if (err) 559 goto out; 560 561 if (unlikely(dn.data_blkaddr == NULL_ADDR)) { 562 ClearPageUptodate(page); 563 goto put_out; 564 } 565 566 /* 567 * don't cache encrypted data into meta inode until previous dirty 568 * data were writebacked to avoid racing between GC and flush. 569 */ 570 f2fs_wait_on_page_writeback(page, DATA, true); 571 572 get_node_info(fio.sbi, dn.nid, &ni); 573 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 574 575 /* read page */ 576 fio.page = page; 577 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr; 578 579 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr, 580 &sum, CURSEG_COLD_DATA); 581 582 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr, 583 FGP_LOCK | FGP_CREAT, GFP_NOFS); 584 if (!fio.encrypted_page) { 585 err = -ENOMEM; 586 goto recover_block; 587 } 588 589 err = f2fs_submit_page_bio(&fio); 590 if (err) 591 goto put_page_out; 592 593 /* write page */ 594 lock_page(fio.encrypted_page); 595 596 if (unlikely(!PageUptodate(fio.encrypted_page))) { 597 err = -EIO; 598 goto put_page_out; 599 } 600 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) { 601 err = -EIO; 602 goto put_page_out; 603 } 604 605 set_page_dirty(fio.encrypted_page); 606 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true); 607 if (clear_page_dirty_for_io(fio.encrypted_page)) 608 dec_page_count(fio.sbi, F2FS_DIRTY_META); 609 610 set_page_writeback(fio.encrypted_page); 611 612 /* allocate block address */ 613 f2fs_wait_on_page_writeback(dn.node_page, NODE, true); 614 615 fio.rw = WRITE_SYNC; 616 fio.new_blkaddr = newaddr; 617 f2fs_submit_page_mbio(&fio); 618 619 f2fs_update_data_blkaddr(&dn, newaddr); 620 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE); 621 if (page->index == 0) 622 set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN); 623 put_page_out: 624 f2fs_put_page(fio.encrypted_page, 1); 625 recover_block: 626 if (err) 627 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr, 628 true, true); 629 put_out: 630 f2fs_put_dnode(&dn); 631 out: 632 f2fs_put_page(page, 1); 633 } 634 635 static void move_data_page(struct inode *inode, block_t bidx, int gc_type) 636 { 637 struct page *page; 638 639 page = get_lock_data_page(inode, bidx, true); 640 if (IS_ERR(page)) 641 return; 642 643 if (gc_type == BG_GC) { 644 if (PageWriteback(page)) 645 goto out; 646 set_page_dirty(page); 647 set_cold_data(page); 648 } else { 649 struct f2fs_io_info fio = { 650 .sbi = F2FS_I_SB(inode), 651 .type = DATA, 652 .rw = WRITE_SYNC, 653 .page = page, 654 .encrypted_page = NULL, 655 }; 656 set_page_dirty(page); 657 f2fs_wait_on_page_writeback(page, DATA, true); 658 if (clear_page_dirty_for_io(page)) 659 inode_dec_dirty_pages(inode); 660 set_cold_data(page); 661 do_write_data_page(&fio); 662 clear_cold_data(page); 663 } 664 out: 665 f2fs_put_page(page, 1); 666 } 667 668 /* 669 * This function tries to get parent node of victim data block, and identifies 670 * data block validity. If the block is valid, copy that with cold status and 671 * modify parent node. 672 * If the parent node is not valid or the data block address is different, 673 * the victim data block is ignored. 674 */ 675 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 676 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 677 { 678 struct super_block *sb = sbi->sb; 679 struct f2fs_summary *entry; 680 block_t start_addr; 681 int off; 682 int phase = 0; 683 684 start_addr = START_BLOCK(sbi, segno); 685 686 next_step: 687 entry = sum; 688 689 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 690 struct page *data_page; 691 struct inode *inode; 692 struct node_info dni; /* dnode info for the data */ 693 unsigned int ofs_in_node, nofs; 694 block_t start_bidx; 695 696 /* stop BG_GC if there is not enough free sections. */ 697 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 698 return; 699 700 if (check_valid_map(sbi, segno, off) == 0) 701 continue; 702 703 if (phase == 0) { 704 ra_node_page(sbi, le32_to_cpu(entry->nid)); 705 continue; 706 } 707 708 /* Get an inode by ino with checking validity */ 709 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 710 continue; 711 712 if (phase == 1) { 713 ra_node_page(sbi, dni.ino); 714 continue; 715 } 716 717 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 718 719 if (phase == 2) { 720 inode = f2fs_iget(sb, dni.ino); 721 if (IS_ERR(inode) || is_bad_inode(inode)) 722 continue; 723 724 /* if encrypted inode, let's go phase 3 */ 725 if (f2fs_encrypted_inode(inode) && 726 S_ISREG(inode->i_mode)) { 727 add_gc_inode(gc_list, inode); 728 continue; 729 } 730 731 start_bidx = start_bidx_of_node(nofs, inode); 732 data_page = get_read_data_page(inode, 733 start_bidx + ofs_in_node, READA, true); 734 if (IS_ERR(data_page)) { 735 iput(inode); 736 continue; 737 } 738 739 f2fs_put_page(data_page, 0); 740 add_gc_inode(gc_list, inode); 741 continue; 742 } 743 744 /* phase 3 */ 745 inode = find_gc_inode(gc_list, dni.ino); 746 if (inode) { 747 start_bidx = start_bidx_of_node(nofs, inode) 748 + ofs_in_node; 749 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) 750 move_encrypted_block(inode, start_bidx); 751 else 752 move_data_page(inode, start_bidx, gc_type); 753 stat_inc_data_blk_count(sbi, 1, gc_type); 754 } 755 } 756 757 if (++phase < 4) 758 goto next_step; 759 } 760 761 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 762 int gc_type) 763 { 764 struct sit_info *sit_i = SIT_I(sbi); 765 int ret; 766 767 mutex_lock(&sit_i->sentry_lock); 768 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 769 NO_CHECK_TYPE, LFS); 770 mutex_unlock(&sit_i->sentry_lock); 771 return ret; 772 } 773 774 static int do_garbage_collect(struct f2fs_sb_info *sbi, 775 unsigned int start_segno, 776 struct gc_inode_list *gc_list, int gc_type) 777 { 778 struct page *sum_page; 779 struct f2fs_summary_block *sum; 780 struct blk_plug plug; 781 unsigned int segno = start_segno; 782 unsigned int end_segno = start_segno + sbi->segs_per_sec; 783 int seg_freed = 0; 784 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ? 785 SUM_TYPE_DATA : SUM_TYPE_NODE; 786 787 /* readahead multi ssa blocks those have contiguous address */ 788 if (sbi->segs_per_sec > 1) 789 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), 790 sbi->segs_per_sec, META_SSA, true); 791 792 /* reference all summary page */ 793 while (segno < end_segno) { 794 sum_page = get_sum_page(sbi, segno++); 795 unlock_page(sum_page); 796 } 797 798 blk_start_plug(&plug); 799 800 for (segno = start_segno; segno < end_segno; segno++) { 801 /* find segment summary of victim */ 802 sum_page = find_get_page(META_MAPPING(sbi), 803 GET_SUM_BLOCK(sbi, segno)); 804 f2fs_bug_on(sbi, !PageUptodate(sum_page)); 805 f2fs_put_page(sum_page, 0); 806 807 sum = page_address(sum_page); 808 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer))); 809 810 /* 811 * this is to avoid deadlock: 812 * - lock_page(sum_page) - f2fs_replace_block 813 * - check_valid_map() - mutex_lock(sentry_lock) 814 * - mutex_lock(sentry_lock) - change_curseg() 815 * - lock_page(sum_page) 816 */ 817 818 if (type == SUM_TYPE_NODE) 819 gc_node_segment(sbi, sum->entries, segno, gc_type); 820 else 821 gc_data_segment(sbi, sum->entries, gc_list, segno, 822 gc_type); 823 824 stat_inc_seg_count(sbi, type, gc_type); 825 826 f2fs_put_page(sum_page, 0); 827 } 828 829 if (gc_type == FG_GC) 830 f2fs_submit_merged_bio(sbi, 831 (type == SUM_TYPE_NODE) ? NODE : DATA, WRITE); 832 833 blk_finish_plug(&plug); 834 835 if (gc_type == FG_GC) { 836 while (start_segno < end_segno) 837 if (get_valid_blocks(sbi, start_segno++, 1) == 0) 838 seg_freed++; 839 } 840 841 stat_inc_call_count(sbi->stat_info); 842 843 return seg_freed; 844 } 845 846 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync) 847 { 848 unsigned int segno; 849 int gc_type = sync ? FG_GC : BG_GC; 850 int sec_freed = 0, seg_freed; 851 int ret = -EINVAL; 852 struct cp_control cpc; 853 struct gc_inode_list gc_list = { 854 .ilist = LIST_HEAD_INIT(gc_list.ilist), 855 .iroot = RADIX_TREE_INIT(GFP_NOFS), 856 }; 857 858 cpc.reason = __get_cp_reason(sbi); 859 gc_more: 860 segno = NULL_SEGNO; 861 862 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) 863 goto stop; 864 if (unlikely(f2fs_cp_error(sbi))) { 865 ret = -EIO; 866 goto stop; 867 } 868 869 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed)) { 870 gc_type = FG_GC; 871 /* 872 * If there is no victim and no prefree segment but still not 873 * enough free sections, we should flush dent/node blocks and do 874 * garbage collections. 875 */ 876 if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) 877 write_checkpoint(sbi, &cpc); 878 else if (has_not_enough_free_secs(sbi, 0)) 879 write_checkpoint(sbi, &cpc); 880 } 881 882 if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type)) 883 goto stop; 884 ret = 0; 885 886 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type); 887 888 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec) 889 sec_freed++; 890 891 if (gc_type == FG_GC) 892 sbi->cur_victim_sec = NULL_SEGNO; 893 894 if (!sync) { 895 if (has_not_enough_free_secs(sbi, sec_freed)) 896 goto gc_more; 897 898 if (gc_type == FG_GC) 899 write_checkpoint(sbi, &cpc); 900 } 901 stop: 902 mutex_unlock(&sbi->gc_mutex); 903 904 put_gc_inode(&gc_list); 905 906 if (sync) 907 ret = sec_freed ? 0 : -EAGAIN; 908 return ret; 909 } 910 911 void build_gc_manager(struct f2fs_sb_info *sbi) 912 { 913 DIRTY_I(sbi)->v_ops = &default_v_ops; 914 } 915