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 #include <linux/blkdev.h> 20 21 #include "f2fs.h" 22 #include "node.h" 23 #include "segment.h" 24 #include "gc.h" 25 #include <trace/events/f2fs.h> 26 27 static int gc_thread_func(void *data) 28 { 29 struct f2fs_sb_info *sbi = data; 30 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 31 wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head; 32 long wait_ms; 33 34 wait_ms = gc_th->min_sleep_time; 35 36 do { 37 if (try_to_freeze()) 38 continue; 39 else 40 wait_event_interruptible_timeout(*wq, 41 kthread_should_stop(), 42 msecs_to_jiffies(wait_ms)); 43 if (kthread_should_stop()) 44 break; 45 46 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) { 47 increase_sleep_time(gc_th, &wait_ms); 48 continue; 49 } 50 51 /* 52 * [GC triggering condition] 53 * 0. GC is not conducted currently. 54 * 1. There are enough dirty segments. 55 * 2. IO subsystem is idle by checking the # of writeback pages. 56 * 3. IO subsystem is idle by checking the # of requests in 57 * bdev's request list. 58 * 59 * Note) We have to avoid triggering GCs frequently. 60 * Because it is possible that some segments can be 61 * invalidated soon after by user update or deletion. 62 * So, I'd like to wait some time to collect dirty segments. 63 */ 64 if (!mutex_trylock(&sbi->gc_mutex)) 65 continue; 66 67 if (!is_idle(sbi)) { 68 increase_sleep_time(gc_th, &wait_ms); 69 mutex_unlock(&sbi->gc_mutex); 70 continue; 71 } 72 73 if (has_enough_invalid_blocks(sbi)) 74 decrease_sleep_time(gc_th, &wait_ms); 75 else 76 increase_sleep_time(gc_th, &wait_ms); 77 78 stat_inc_bggc_count(sbi); 79 80 /* if return value is not zero, no victim was selected */ 81 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC))) 82 wait_ms = gc_th->no_gc_sleep_time; 83 84 trace_f2fs_background_gc(sbi->sb, wait_ms, 85 prefree_segments(sbi), free_segments(sbi)); 86 87 /* balancing f2fs's metadata periodically */ 88 f2fs_balance_fs_bg(sbi); 89 90 } while (!kthread_should_stop()); 91 return 0; 92 } 93 94 int start_gc_thread(struct f2fs_sb_info *sbi) 95 { 96 struct f2fs_gc_kthread *gc_th; 97 dev_t dev = sbi->sb->s_bdev->bd_dev; 98 int err = 0; 99 100 gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL); 101 if (!gc_th) { 102 err = -ENOMEM; 103 goto out; 104 } 105 106 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; 107 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; 108 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; 109 110 gc_th->gc_idle = 0; 111 112 sbi->gc_thread = gc_th; 113 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); 114 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, 115 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); 116 if (IS_ERR(gc_th->f2fs_gc_task)) { 117 err = PTR_ERR(gc_th->f2fs_gc_task); 118 kfree(gc_th); 119 sbi->gc_thread = NULL; 120 } 121 out: 122 return err; 123 } 124 125 void stop_gc_thread(struct f2fs_sb_info *sbi) 126 { 127 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 128 if (!gc_th) 129 return; 130 kthread_stop(gc_th->f2fs_gc_task); 131 kfree(gc_th); 132 sbi->gc_thread = NULL; 133 } 134 135 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) 136 { 137 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; 138 139 if (gc_th && gc_th->gc_idle) { 140 if (gc_th->gc_idle == 1) 141 gc_mode = GC_CB; 142 else if (gc_th->gc_idle == 2) 143 gc_mode = GC_GREEDY; 144 } 145 return gc_mode; 146 } 147 148 static void select_policy(struct f2fs_sb_info *sbi, int gc_type, 149 int type, struct victim_sel_policy *p) 150 { 151 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 152 153 if (p->alloc_mode == SSR) { 154 p->gc_mode = GC_GREEDY; 155 p->dirty_segmap = dirty_i->dirty_segmap[type]; 156 p->max_search = dirty_i->nr_dirty[type]; 157 p->ofs_unit = 1; 158 } else { 159 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type); 160 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; 161 p->max_search = dirty_i->nr_dirty[DIRTY]; 162 p->ofs_unit = sbi->segs_per_sec; 163 } 164 165 if (p->max_search > sbi->max_victim_search) 166 p->max_search = sbi->max_victim_search; 167 168 p->offset = sbi->last_victim[p->gc_mode]; 169 } 170 171 static unsigned int get_max_cost(struct f2fs_sb_info *sbi, 172 struct victim_sel_policy *p) 173 { 174 /* SSR allocates in a segment unit */ 175 if (p->alloc_mode == SSR) 176 return 1 << sbi->log_blocks_per_seg; 177 if (p->gc_mode == GC_GREEDY) 178 return (1 << sbi->log_blocks_per_seg) * p->ofs_unit; 179 else if (p->gc_mode == GC_CB) 180 return UINT_MAX; 181 else /* No other gc_mode */ 182 return 0; 183 } 184 185 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) 186 { 187 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 188 unsigned int secno; 189 190 /* 191 * If the gc_type is FG_GC, we can select victim segments 192 * selected by background GC before. 193 * Those segments guarantee they have small valid blocks. 194 */ 195 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { 196 if (sec_usage_check(sbi, secno)) 197 continue; 198 clear_bit(secno, dirty_i->victim_secmap); 199 return secno * sbi->segs_per_sec; 200 } 201 return NULL_SEGNO; 202 } 203 204 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) 205 { 206 struct sit_info *sit_i = SIT_I(sbi); 207 unsigned int secno = GET_SECNO(sbi, segno); 208 unsigned int start = secno * sbi->segs_per_sec; 209 unsigned long long mtime = 0; 210 unsigned int vblocks; 211 unsigned char age = 0; 212 unsigned char u; 213 unsigned int i; 214 215 for (i = 0; i < sbi->segs_per_sec; i++) 216 mtime += get_seg_entry(sbi, start + i)->mtime; 217 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec); 218 219 mtime = div_u64(mtime, sbi->segs_per_sec); 220 vblocks = div_u64(vblocks, sbi->segs_per_sec); 221 222 u = (vblocks * 100) >> sbi->log_blocks_per_seg; 223 224 /* Handle if the system time has changed by the user */ 225 if (mtime < sit_i->min_mtime) 226 sit_i->min_mtime = mtime; 227 if (mtime > sit_i->max_mtime) 228 sit_i->max_mtime = mtime; 229 if (sit_i->max_mtime != sit_i->min_mtime) 230 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), 231 sit_i->max_mtime - sit_i->min_mtime); 232 233 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); 234 } 235 236 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 237 unsigned int segno, struct victim_sel_policy *p) 238 { 239 if (p->alloc_mode == SSR) 240 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 241 242 /* alloc_mode == LFS */ 243 if (p->gc_mode == GC_GREEDY) 244 return get_valid_blocks(sbi, segno, sbi->segs_per_sec); 245 else 246 return get_cb_cost(sbi, segno); 247 } 248 249 /* 250 * This function is called from two paths. 251 * One is garbage collection and the other is SSR segment selection. 252 * When it is called during GC, it just gets a victim segment 253 * and it does not remove it from dirty seglist. 254 * When it is called from SSR segment selection, it finds a segment 255 * which has minimum valid blocks and removes it from dirty seglist. 256 */ 257 static int get_victim_by_default(struct f2fs_sb_info *sbi, 258 unsigned int *result, int gc_type, int type, char alloc_mode) 259 { 260 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 261 struct victim_sel_policy p; 262 unsigned int secno, max_cost; 263 unsigned int last_segment = MAIN_SEGS(sbi); 264 int nsearched = 0; 265 266 mutex_lock(&dirty_i->seglist_lock); 267 268 p.alloc_mode = alloc_mode; 269 select_policy(sbi, gc_type, type, &p); 270 271 p.min_segno = NULL_SEGNO; 272 p.min_cost = max_cost = get_max_cost(sbi, &p); 273 274 if (p.max_search == 0) 275 goto out; 276 277 if (p.alloc_mode == LFS && gc_type == FG_GC) { 278 p.min_segno = check_bg_victims(sbi); 279 if (p.min_segno != NULL_SEGNO) 280 goto got_it; 281 } 282 283 while (1) { 284 unsigned long cost; 285 unsigned int segno; 286 287 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset); 288 if (segno >= last_segment) { 289 if (sbi->last_victim[p.gc_mode]) { 290 last_segment = sbi->last_victim[p.gc_mode]; 291 sbi->last_victim[p.gc_mode] = 0; 292 p.offset = 0; 293 continue; 294 } 295 break; 296 } 297 298 p.offset = segno + p.ofs_unit; 299 if (p.ofs_unit > 1) 300 p.offset -= segno % p.ofs_unit; 301 302 secno = GET_SECNO(sbi, segno); 303 304 if (sec_usage_check(sbi, secno)) 305 continue; 306 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 307 continue; 308 309 cost = get_gc_cost(sbi, segno, &p); 310 311 if (p.min_cost > cost) { 312 p.min_segno = segno; 313 p.min_cost = cost; 314 } else if (unlikely(cost == max_cost)) { 315 continue; 316 } 317 318 if (nsearched++ >= p.max_search) { 319 sbi->last_victim[p.gc_mode] = segno; 320 break; 321 } 322 } 323 if (p.min_segno != NULL_SEGNO) { 324 got_it: 325 if (p.alloc_mode == LFS) { 326 secno = GET_SECNO(sbi, p.min_segno); 327 if (gc_type == FG_GC) 328 sbi->cur_victim_sec = secno; 329 else 330 set_bit(secno, dirty_i->victim_secmap); 331 } 332 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 333 334 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 335 sbi->cur_victim_sec, 336 prefree_segments(sbi), free_segments(sbi)); 337 } 338 out: 339 mutex_unlock(&dirty_i->seglist_lock); 340 341 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 342 } 343 344 static const struct victim_selection default_v_ops = { 345 .get_victim = get_victim_by_default, 346 }; 347 348 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 349 { 350 struct inode_entry *ie; 351 352 ie = radix_tree_lookup(&gc_list->iroot, ino); 353 if (ie) 354 return ie->inode; 355 return NULL; 356 } 357 358 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 359 { 360 struct inode_entry *new_ie; 361 362 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 363 iput(inode); 364 return; 365 } 366 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); 367 new_ie->inode = inode; 368 369 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 370 list_add_tail(&new_ie->list, &gc_list->ilist); 371 } 372 373 static void put_gc_inode(struct gc_inode_list *gc_list) 374 { 375 struct inode_entry *ie, *next_ie; 376 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 377 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 378 iput(ie->inode); 379 list_del(&ie->list); 380 kmem_cache_free(inode_entry_slab, ie); 381 } 382 } 383 384 static int check_valid_map(struct f2fs_sb_info *sbi, 385 unsigned int segno, int offset) 386 { 387 struct sit_info *sit_i = SIT_I(sbi); 388 struct seg_entry *sentry; 389 int ret; 390 391 mutex_lock(&sit_i->sentry_lock); 392 sentry = get_seg_entry(sbi, segno); 393 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 394 mutex_unlock(&sit_i->sentry_lock); 395 return ret; 396 } 397 398 /* 399 * This function compares node address got in summary with that in NAT. 400 * On validity, copy that node with cold status, otherwise (invalid node) 401 * ignore that. 402 */ 403 static int gc_node_segment(struct f2fs_sb_info *sbi, 404 struct f2fs_summary *sum, unsigned int segno, int gc_type) 405 { 406 bool initial = true; 407 struct f2fs_summary *entry; 408 block_t start_addr; 409 int off; 410 411 start_addr = START_BLOCK(sbi, segno); 412 413 next_step: 414 entry = sum; 415 416 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 417 nid_t nid = le32_to_cpu(entry->nid); 418 struct page *node_page; 419 struct node_info ni; 420 421 /* stop BG_GC if there is not enough free sections. */ 422 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 423 return 0; 424 425 if (check_valid_map(sbi, segno, off) == 0) 426 continue; 427 428 if (initial) { 429 ra_node_page(sbi, nid); 430 continue; 431 } 432 node_page = get_node_page(sbi, nid); 433 if (IS_ERR(node_page)) 434 continue; 435 436 /* block may become invalid during get_node_page */ 437 if (check_valid_map(sbi, segno, off) == 0) { 438 f2fs_put_page(node_page, 1); 439 continue; 440 } 441 442 get_node_info(sbi, nid, &ni); 443 if (ni.blk_addr != start_addr + off) { 444 f2fs_put_page(node_page, 1); 445 continue; 446 } 447 448 /* set page dirty and write it */ 449 if (gc_type == FG_GC) { 450 f2fs_wait_on_page_writeback(node_page, NODE); 451 set_page_dirty(node_page); 452 } else { 453 if (!PageWriteback(node_page)) 454 set_page_dirty(node_page); 455 } 456 f2fs_put_page(node_page, 1); 457 stat_inc_node_blk_count(sbi, 1, gc_type); 458 } 459 460 if (initial) { 461 initial = false; 462 goto next_step; 463 } 464 465 if (gc_type == FG_GC) { 466 struct writeback_control wbc = { 467 .sync_mode = WB_SYNC_ALL, 468 .nr_to_write = LONG_MAX, 469 .for_reclaim = 0, 470 }; 471 sync_node_pages(sbi, 0, &wbc); 472 473 /* return 1 only if FG_GC succefully reclaimed one */ 474 if (get_valid_blocks(sbi, segno, 1) == 0) 475 return 1; 476 } 477 return 0; 478 } 479 480 /* 481 * Calculate start block index indicating the given node offset. 482 * Be careful, caller should give this node offset only indicating direct node 483 * blocks. If any node offsets, which point the other types of node blocks such 484 * as indirect or double indirect node blocks, are given, it must be a caller's 485 * bug. 486 */ 487 block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi) 488 { 489 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 490 unsigned int bidx; 491 492 if (node_ofs == 0) 493 return 0; 494 495 if (node_ofs <= 2) { 496 bidx = node_ofs - 1; 497 } else if (node_ofs <= indirect_blks) { 498 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 499 bidx = node_ofs - 2 - dec; 500 } else { 501 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 502 bidx = node_ofs - 5 - dec; 503 } 504 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi); 505 } 506 507 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 508 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 509 { 510 struct page *node_page; 511 nid_t nid; 512 unsigned int ofs_in_node; 513 block_t source_blkaddr; 514 515 nid = le32_to_cpu(sum->nid); 516 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 517 518 node_page = get_node_page(sbi, nid); 519 if (IS_ERR(node_page)) 520 return false; 521 522 get_node_info(sbi, nid, dni); 523 524 if (sum->version != dni->version) { 525 f2fs_put_page(node_page, 1); 526 return false; 527 } 528 529 *nofs = ofs_of_node(node_page); 530 source_blkaddr = datablock_addr(node_page, ofs_in_node); 531 f2fs_put_page(node_page, 1); 532 533 if (source_blkaddr != blkaddr) 534 return false; 535 return true; 536 } 537 538 static void move_encrypted_block(struct inode *inode, block_t bidx) 539 { 540 struct f2fs_io_info fio = { 541 .sbi = F2FS_I_SB(inode), 542 .type = DATA, 543 .rw = READ_SYNC, 544 .encrypted_page = NULL, 545 }; 546 struct dnode_of_data dn; 547 struct f2fs_summary sum; 548 struct node_info ni; 549 struct page *page; 550 int err; 551 552 /* do not read out */ 553 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false); 554 if (!page) 555 return; 556 557 set_new_dnode(&dn, inode, NULL, NULL, 0); 558 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 559 if (err) 560 goto out; 561 562 if (unlikely(dn.data_blkaddr == NULL_ADDR)) { 563 ClearPageUptodate(page); 564 goto put_out; 565 } 566 567 /* 568 * don't cache encrypted data into meta inode until previous dirty 569 * data were writebacked to avoid racing between GC and flush. 570 */ 571 f2fs_wait_on_page_writeback(page, DATA); 572 573 get_node_info(fio.sbi, dn.nid, &ni); 574 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 575 576 /* read page */ 577 fio.page = page; 578 fio.blk_addr = dn.data_blkaddr; 579 580 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), 581 fio.blk_addr, 582 FGP_LOCK|FGP_CREAT, 583 GFP_NOFS); 584 if (!fio.encrypted_page) 585 goto put_out; 586 587 err = f2fs_submit_page_bio(&fio); 588 if (err) 589 goto put_page_out; 590 591 /* write page */ 592 lock_page(fio.encrypted_page); 593 594 if (unlikely(!PageUptodate(fio.encrypted_page))) 595 goto put_page_out; 596 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) 597 goto put_page_out; 598 599 set_page_dirty(fio.encrypted_page); 600 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA); 601 if (clear_page_dirty_for_io(fio.encrypted_page)) 602 dec_page_count(fio.sbi, F2FS_DIRTY_META); 603 604 set_page_writeback(fio.encrypted_page); 605 606 /* allocate block address */ 607 f2fs_wait_on_page_writeback(dn.node_page, NODE); 608 allocate_data_block(fio.sbi, NULL, fio.blk_addr, 609 &fio.blk_addr, &sum, CURSEG_COLD_DATA); 610 fio.rw = WRITE_SYNC; 611 f2fs_submit_page_mbio(&fio); 612 613 dn.data_blkaddr = fio.blk_addr; 614 set_data_blkaddr(&dn); 615 f2fs_update_extent_cache(&dn); 616 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE); 617 if (page->index == 0) 618 set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN); 619 put_page_out: 620 f2fs_put_page(fio.encrypted_page, 1); 621 put_out: 622 f2fs_put_dnode(&dn); 623 out: 624 f2fs_put_page(page, 1); 625 } 626 627 static void move_data_page(struct inode *inode, block_t bidx, int gc_type) 628 { 629 struct page *page; 630 631 page = get_lock_data_page(inode, bidx, true); 632 if (IS_ERR(page)) 633 return; 634 635 if (gc_type == BG_GC) { 636 if (PageWriteback(page)) 637 goto out; 638 set_page_dirty(page); 639 set_cold_data(page); 640 } else { 641 struct f2fs_io_info fio = { 642 .sbi = F2FS_I_SB(inode), 643 .type = DATA, 644 .rw = WRITE_SYNC, 645 .page = page, 646 .encrypted_page = NULL, 647 }; 648 set_page_dirty(page); 649 f2fs_wait_on_page_writeback(page, DATA); 650 if (clear_page_dirty_for_io(page)) 651 inode_dec_dirty_pages(inode); 652 set_cold_data(page); 653 do_write_data_page(&fio); 654 clear_cold_data(page); 655 } 656 out: 657 f2fs_put_page(page, 1); 658 } 659 660 /* 661 * This function tries to get parent node of victim data block, and identifies 662 * data block validity. If the block is valid, copy that with cold status and 663 * modify parent node. 664 * If the parent node is not valid or the data block address is different, 665 * the victim data block is ignored. 666 */ 667 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 668 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 669 { 670 struct super_block *sb = sbi->sb; 671 struct f2fs_summary *entry; 672 block_t start_addr; 673 int off; 674 int phase = 0; 675 676 start_addr = START_BLOCK(sbi, segno); 677 678 next_step: 679 entry = sum; 680 681 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 682 struct page *data_page; 683 struct inode *inode; 684 struct node_info dni; /* dnode info for the data */ 685 unsigned int ofs_in_node, nofs; 686 block_t start_bidx; 687 688 /* stop BG_GC if there is not enough free sections. */ 689 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 690 return 0; 691 692 if (check_valid_map(sbi, segno, off) == 0) 693 continue; 694 695 if (phase == 0) { 696 ra_node_page(sbi, le32_to_cpu(entry->nid)); 697 continue; 698 } 699 700 /* Get an inode by ino with checking validity */ 701 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 702 continue; 703 704 if (phase == 1) { 705 ra_node_page(sbi, dni.ino); 706 continue; 707 } 708 709 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 710 711 if (phase == 2) { 712 inode = f2fs_iget(sb, dni.ino); 713 if (IS_ERR(inode) || is_bad_inode(inode)) 714 continue; 715 716 /* if encrypted inode, let's go phase 3 */ 717 if (f2fs_encrypted_inode(inode) && 718 S_ISREG(inode->i_mode)) { 719 add_gc_inode(gc_list, inode); 720 continue; 721 } 722 723 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)); 724 data_page = get_read_data_page(inode, 725 start_bidx + ofs_in_node, READA, true); 726 if (IS_ERR(data_page)) { 727 iput(inode); 728 continue; 729 } 730 731 f2fs_put_page(data_page, 0); 732 add_gc_inode(gc_list, inode); 733 continue; 734 } 735 736 /* phase 3 */ 737 inode = find_gc_inode(gc_list, dni.ino); 738 if (inode) { 739 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)) 740 + ofs_in_node; 741 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) 742 move_encrypted_block(inode, start_bidx); 743 else 744 move_data_page(inode, start_bidx, gc_type); 745 stat_inc_data_blk_count(sbi, 1, gc_type); 746 } 747 } 748 749 if (++phase < 4) 750 goto next_step; 751 752 if (gc_type == FG_GC) { 753 f2fs_submit_merged_bio(sbi, DATA, WRITE); 754 755 /* return 1 only if FG_GC succefully reclaimed one */ 756 if (get_valid_blocks(sbi, segno, 1) == 0) 757 return 1; 758 } 759 return 0; 760 } 761 762 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 763 int gc_type) 764 { 765 struct sit_info *sit_i = SIT_I(sbi); 766 int ret; 767 768 mutex_lock(&sit_i->sentry_lock); 769 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 770 NO_CHECK_TYPE, LFS); 771 mutex_unlock(&sit_i->sentry_lock); 772 return ret; 773 } 774 775 static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int 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 int nfree = 0; 782 783 /* read segment summary of victim */ 784 sum_page = get_sum_page(sbi, segno); 785 786 blk_start_plug(&plug); 787 788 sum = page_address(sum_page); 789 790 /* 791 * this is to avoid deadlock: 792 * - lock_page(sum_page) - f2fs_replace_block 793 * - check_valid_map() - mutex_lock(sentry_lock) 794 * - mutex_lock(sentry_lock) - change_curseg() 795 * - lock_page(sum_page) 796 */ 797 unlock_page(sum_page); 798 799 switch (GET_SUM_TYPE((&sum->footer))) { 800 case SUM_TYPE_NODE: 801 nfree = gc_node_segment(sbi, sum->entries, segno, gc_type); 802 break; 803 case SUM_TYPE_DATA: 804 nfree = gc_data_segment(sbi, sum->entries, gc_list, 805 segno, gc_type); 806 break; 807 } 808 blk_finish_plug(&plug); 809 810 stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type); 811 stat_inc_call_count(sbi->stat_info); 812 813 f2fs_put_page(sum_page, 0); 814 return nfree; 815 } 816 817 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync) 818 { 819 unsigned int segno, i; 820 int gc_type = sync ? FG_GC : BG_GC; 821 int sec_freed = 0; 822 int ret = -EINVAL; 823 struct cp_control cpc; 824 struct gc_inode_list gc_list = { 825 .ilist = LIST_HEAD_INIT(gc_list.ilist), 826 .iroot = RADIX_TREE_INIT(GFP_NOFS), 827 }; 828 829 cpc.reason = __get_cp_reason(sbi); 830 gc_more: 831 segno = NULL_SEGNO; 832 833 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) 834 goto stop; 835 if (unlikely(f2fs_cp_error(sbi))) 836 goto stop; 837 838 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed)) { 839 gc_type = FG_GC; 840 if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) 841 write_checkpoint(sbi, &cpc); 842 } 843 844 if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type)) 845 goto stop; 846 ret = 0; 847 848 /* readahead multi ssa blocks those have contiguous address */ 849 if (sbi->segs_per_sec > 1) 850 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec, 851 META_SSA, true); 852 853 for (i = 0; i < sbi->segs_per_sec; i++) { 854 /* 855 * for FG_GC case, halt gcing left segments once failed one 856 * of segments in selected section to avoid long latency. 857 */ 858 if (!do_garbage_collect(sbi, segno + i, &gc_list, gc_type) && 859 gc_type == FG_GC) 860 break; 861 } 862 863 if (i == sbi->segs_per_sec && gc_type == FG_GC) 864 sec_freed++; 865 866 if (gc_type == FG_GC) 867 sbi->cur_victim_sec = NULL_SEGNO; 868 869 if (!sync) { 870 if (has_not_enough_free_secs(sbi, sec_freed)) 871 goto gc_more; 872 873 if (gc_type == FG_GC) 874 write_checkpoint(sbi, &cpc); 875 } 876 stop: 877 mutex_unlock(&sbi->gc_mutex); 878 879 put_gc_inode(&gc_list); 880 881 if (sync) 882 ret = sec_freed ? 0 : -EAGAIN; 883 return ret; 884 } 885 886 void build_gc_manager(struct f2fs_sb_info *sbi) 887 { 888 DIRTY_I(sbi)->v_ops = &default_v_ops; 889 } 890