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)) 82 wait_ms = gc_th->no_gc_sleep_time; 83 84 /* balancing f2fs's metadata periodically */ 85 f2fs_balance_fs_bg(sbi); 86 87 } while (!kthread_should_stop()); 88 return 0; 89 } 90 91 int start_gc_thread(struct f2fs_sb_info *sbi) 92 { 93 struct f2fs_gc_kthread *gc_th; 94 dev_t dev = sbi->sb->s_bdev->bd_dev; 95 int err = 0; 96 97 gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL); 98 if (!gc_th) { 99 err = -ENOMEM; 100 goto out; 101 } 102 103 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME; 104 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME; 105 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME; 106 107 gc_th->gc_idle = 0; 108 109 sbi->gc_thread = gc_th; 110 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head); 111 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi, 112 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev)); 113 if (IS_ERR(gc_th->f2fs_gc_task)) { 114 err = PTR_ERR(gc_th->f2fs_gc_task); 115 kfree(gc_th); 116 sbi->gc_thread = NULL; 117 } 118 out: 119 return err; 120 } 121 122 void stop_gc_thread(struct f2fs_sb_info *sbi) 123 { 124 struct f2fs_gc_kthread *gc_th = sbi->gc_thread; 125 if (!gc_th) 126 return; 127 kthread_stop(gc_th->f2fs_gc_task); 128 kfree(gc_th); 129 sbi->gc_thread = NULL; 130 } 131 132 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type) 133 { 134 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY; 135 136 if (gc_th && gc_th->gc_idle) { 137 if (gc_th->gc_idle == 1) 138 gc_mode = GC_CB; 139 else if (gc_th->gc_idle == 2) 140 gc_mode = GC_GREEDY; 141 } 142 return gc_mode; 143 } 144 145 static void select_policy(struct f2fs_sb_info *sbi, int gc_type, 146 int type, struct victim_sel_policy *p) 147 { 148 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 149 150 if (p->alloc_mode == SSR) { 151 p->gc_mode = GC_GREEDY; 152 p->dirty_segmap = dirty_i->dirty_segmap[type]; 153 p->max_search = dirty_i->nr_dirty[type]; 154 p->ofs_unit = 1; 155 } else { 156 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type); 157 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY]; 158 p->max_search = dirty_i->nr_dirty[DIRTY]; 159 p->ofs_unit = sbi->segs_per_sec; 160 } 161 162 if (p->max_search > sbi->max_victim_search) 163 p->max_search = sbi->max_victim_search; 164 165 p->offset = sbi->last_victim[p->gc_mode]; 166 } 167 168 static unsigned int get_max_cost(struct f2fs_sb_info *sbi, 169 struct victim_sel_policy *p) 170 { 171 /* SSR allocates in a segment unit */ 172 if (p->alloc_mode == SSR) 173 return 1 << sbi->log_blocks_per_seg; 174 if (p->gc_mode == GC_GREEDY) 175 return (1 << sbi->log_blocks_per_seg) * p->ofs_unit; 176 else if (p->gc_mode == GC_CB) 177 return UINT_MAX; 178 else /* No other gc_mode */ 179 return 0; 180 } 181 182 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi) 183 { 184 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 185 unsigned int secno; 186 187 /* 188 * If the gc_type is FG_GC, we can select victim segments 189 * selected by background GC before. 190 * Those segments guarantee they have small valid blocks. 191 */ 192 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) { 193 if (sec_usage_check(sbi, secno)) 194 continue; 195 clear_bit(secno, dirty_i->victim_secmap); 196 return secno * sbi->segs_per_sec; 197 } 198 return NULL_SEGNO; 199 } 200 201 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno) 202 { 203 struct sit_info *sit_i = SIT_I(sbi); 204 unsigned int secno = GET_SECNO(sbi, segno); 205 unsigned int start = secno * sbi->segs_per_sec; 206 unsigned long long mtime = 0; 207 unsigned int vblocks; 208 unsigned char age = 0; 209 unsigned char u; 210 unsigned int i; 211 212 for (i = 0; i < sbi->segs_per_sec; i++) 213 mtime += get_seg_entry(sbi, start + i)->mtime; 214 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec); 215 216 mtime = div_u64(mtime, sbi->segs_per_sec); 217 vblocks = div_u64(vblocks, sbi->segs_per_sec); 218 219 u = (vblocks * 100) >> sbi->log_blocks_per_seg; 220 221 /* Handle if the system time has changed by the user */ 222 if (mtime < sit_i->min_mtime) 223 sit_i->min_mtime = mtime; 224 if (mtime > sit_i->max_mtime) 225 sit_i->max_mtime = mtime; 226 if (sit_i->max_mtime != sit_i->min_mtime) 227 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime), 228 sit_i->max_mtime - sit_i->min_mtime); 229 230 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u)); 231 } 232 233 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi, 234 unsigned int segno, struct victim_sel_policy *p) 235 { 236 if (p->alloc_mode == SSR) 237 return get_seg_entry(sbi, segno)->ckpt_valid_blocks; 238 239 /* alloc_mode == LFS */ 240 if (p->gc_mode == GC_GREEDY) 241 return get_valid_blocks(sbi, segno, sbi->segs_per_sec); 242 else 243 return get_cb_cost(sbi, segno); 244 } 245 246 /* 247 * This function is called from two paths. 248 * One is garbage collection and the other is SSR segment selection. 249 * When it is called during GC, it just gets a victim segment 250 * and it does not remove it from dirty seglist. 251 * When it is called from SSR segment selection, it finds a segment 252 * which has minimum valid blocks and removes it from dirty seglist. 253 */ 254 static int get_victim_by_default(struct f2fs_sb_info *sbi, 255 unsigned int *result, int gc_type, int type, char alloc_mode) 256 { 257 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi); 258 struct victim_sel_policy p; 259 unsigned int secno, max_cost; 260 int nsearched = 0; 261 262 mutex_lock(&dirty_i->seglist_lock); 263 264 p.alloc_mode = alloc_mode; 265 select_policy(sbi, gc_type, type, &p); 266 267 p.min_segno = NULL_SEGNO; 268 p.min_cost = max_cost = get_max_cost(sbi, &p); 269 270 if (p.alloc_mode == LFS && gc_type == FG_GC) { 271 p.min_segno = check_bg_victims(sbi); 272 if (p.min_segno != NULL_SEGNO) 273 goto got_it; 274 } 275 276 while (1) { 277 unsigned long cost; 278 unsigned int segno; 279 280 segno = find_next_bit(p.dirty_segmap, MAIN_SEGS(sbi), p.offset); 281 if (segno >= MAIN_SEGS(sbi)) { 282 if (sbi->last_victim[p.gc_mode]) { 283 sbi->last_victim[p.gc_mode] = 0; 284 p.offset = 0; 285 continue; 286 } 287 break; 288 } 289 290 p.offset = segno + p.ofs_unit; 291 if (p.ofs_unit > 1) 292 p.offset -= segno % p.ofs_unit; 293 294 secno = GET_SECNO(sbi, segno); 295 296 if (sec_usage_check(sbi, secno)) 297 continue; 298 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap)) 299 continue; 300 301 cost = get_gc_cost(sbi, segno, &p); 302 303 if (p.min_cost > cost) { 304 p.min_segno = segno; 305 p.min_cost = cost; 306 } else if (unlikely(cost == max_cost)) { 307 continue; 308 } 309 310 if (nsearched++ >= p.max_search) { 311 sbi->last_victim[p.gc_mode] = segno; 312 break; 313 } 314 } 315 if (p.min_segno != NULL_SEGNO) { 316 got_it: 317 if (p.alloc_mode == LFS) { 318 secno = GET_SECNO(sbi, p.min_segno); 319 if (gc_type == FG_GC) 320 sbi->cur_victim_sec = secno; 321 else 322 set_bit(secno, dirty_i->victim_secmap); 323 } 324 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit; 325 326 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p, 327 sbi->cur_victim_sec, 328 prefree_segments(sbi), free_segments(sbi)); 329 } 330 mutex_unlock(&dirty_i->seglist_lock); 331 332 return (p.min_segno == NULL_SEGNO) ? 0 : 1; 333 } 334 335 static const struct victim_selection default_v_ops = { 336 .get_victim = get_victim_by_default, 337 }; 338 339 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino) 340 { 341 struct inode_entry *ie; 342 343 ie = radix_tree_lookup(&gc_list->iroot, ino); 344 if (ie) 345 return ie->inode; 346 return NULL; 347 } 348 349 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode) 350 { 351 struct inode_entry *new_ie; 352 353 if (inode == find_gc_inode(gc_list, inode->i_ino)) { 354 iput(inode); 355 return; 356 } 357 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS); 358 new_ie->inode = inode; 359 360 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie); 361 list_add_tail(&new_ie->list, &gc_list->ilist); 362 } 363 364 static void put_gc_inode(struct gc_inode_list *gc_list) 365 { 366 struct inode_entry *ie, *next_ie; 367 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) { 368 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino); 369 iput(ie->inode); 370 list_del(&ie->list); 371 kmem_cache_free(inode_entry_slab, ie); 372 } 373 } 374 375 static int check_valid_map(struct f2fs_sb_info *sbi, 376 unsigned int segno, int offset) 377 { 378 struct sit_info *sit_i = SIT_I(sbi); 379 struct seg_entry *sentry; 380 int ret; 381 382 mutex_lock(&sit_i->sentry_lock); 383 sentry = get_seg_entry(sbi, segno); 384 ret = f2fs_test_bit(offset, sentry->cur_valid_map); 385 mutex_unlock(&sit_i->sentry_lock); 386 return ret; 387 } 388 389 /* 390 * This function compares node address got in summary with that in NAT. 391 * On validity, copy that node with cold status, otherwise (invalid node) 392 * ignore that. 393 */ 394 static void gc_node_segment(struct f2fs_sb_info *sbi, 395 struct f2fs_summary *sum, unsigned int segno, int gc_type) 396 { 397 bool initial = true; 398 struct f2fs_summary *entry; 399 int off; 400 401 next_step: 402 entry = sum; 403 404 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 405 nid_t nid = le32_to_cpu(entry->nid); 406 struct page *node_page; 407 408 /* stop BG_GC if there is not enough free sections. */ 409 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 410 return; 411 412 if (check_valid_map(sbi, segno, off) == 0) 413 continue; 414 415 if (initial) { 416 ra_node_page(sbi, nid); 417 continue; 418 } 419 node_page = get_node_page(sbi, nid); 420 if (IS_ERR(node_page)) 421 continue; 422 423 /* block may become invalid during get_node_page */ 424 if (check_valid_map(sbi, segno, off) == 0) { 425 f2fs_put_page(node_page, 1); 426 continue; 427 } 428 429 /* set page dirty and write it */ 430 if (gc_type == FG_GC) { 431 f2fs_wait_on_page_writeback(node_page, NODE); 432 set_page_dirty(node_page); 433 } else { 434 if (!PageWriteback(node_page)) 435 set_page_dirty(node_page); 436 } 437 f2fs_put_page(node_page, 1); 438 stat_inc_node_blk_count(sbi, 1, gc_type); 439 } 440 441 if (initial) { 442 initial = false; 443 goto next_step; 444 } 445 446 if (gc_type == FG_GC) { 447 struct writeback_control wbc = { 448 .sync_mode = WB_SYNC_ALL, 449 .nr_to_write = LONG_MAX, 450 .for_reclaim = 0, 451 }; 452 sync_node_pages(sbi, 0, &wbc); 453 454 /* 455 * In the case of FG_GC, it'd be better to reclaim this victim 456 * completely. 457 */ 458 if (get_valid_blocks(sbi, segno, 1) != 0) 459 goto next_step; 460 } 461 } 462 463 /* 464 * Calculate start block index indicating the given node offset. 465 * Be careful, caller should give this node offset only indicating direct node 466 * blocks. If any node offsets, which point the other types of node blocks such 467 * as indirect or double indirect node blocks, are given, it must be a caller's 468 * bug. 469 */ 470 block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi) 471 { 472 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 473 unsigned int bidx; 474 475 if (node_ofs == 0) 476 return 0; 477 478 if (node_ofs <= 2) { 479 bidx = node_ofs - 1; 480 } else if (node_ofs <= indirect_blks) { 481 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 482 bidx = node_ofs - 2 - dec; 483 } else { 484 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 485 bidx = node_ofs - 5 - dec; 486 } 487 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi); 488 } 489 490 static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 491 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 492 { 493 struct page *node_page; 494 nid_t nid; 495 unsigned int ofs_in_node; 496 block_t source_blkaddr; 497 498 nid = le32_to_cpu(sum->nid); 499 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 500 501 node_page = get_node_page(sbi, nid); 502 if (IS_ERR(node_page)) 503 return 0; 504 505 get_node_info(sbi, nid, dni); 506 507 if (sum->version != dni->version) { 508 f2fs_put_page(node_page, 1); 509 return 0; 510 } 511 512 *nofs = ofs_of_node(node_page); 513 source_blkaddr = datablock_addr(node_page, ofs_in_node); 514 f2fs_put_page(node_page, 1); 515 516 if (source_blkaddr != blkaddr) 517 return 0; 518 return 1; 519 } 520 521 static void move_encrypted_block(struct inode *inode, block_t bidx) 522 { 523 struct f2fs_io_info fio = { 524 .sbi = F2FS_I_SB(inode), 525 .type = DATA, 526 .rw = READ_SYNC, 527 .encrypted_page = NULL, 528 }; 529 struct dnode_of_data dn; 530 struct f2fs_summary sum; 531 struct node_info ni; 532 struct page *page; 533 int err; 534 535 /* do not read out */ 536 page = grab_cache_page(inode->i_mapping, bidx); 537 if (!page) 538 return; 539 540 set_new_dnode(&dn, inode, NULL, NULL, 0); 541 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 542 if (err) 543 goto out; 544 545 if (unlikely(dn.data_blkaddr == NULL_ADDR)) 546 goto put_out; 547 548 get_node_info(fio.sbi, dn.nid, &ni); 549 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 550 551 /* read page */ 552 fio.page = page; 553 fio.blk_addr = dn.data_blkaddr; 554 555 fio.encrypted_page = grab_cache_page(META_MAPPING(fio.sbi), fio.blk_addr); 556 if (!fio.encrypted_page) 557 goto put_out; 558 559 err = f2fs_submit_page_bio(&fio); 560 if (err) 561 goto put_page_out; 562 563 /* write page */ 564 lock_page(fio.encrypted_page); 565 566 if (unlikely(!PageUptodate(fio.encrypted_page))) 567 goto put_page_out; 568 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) 569 goto put_page_out; 570 571 set_page_dirty(fio.encrypted_page); 572 f2fs_wait_on_page_writeback(fio.encrypted_page, META); 573 if (clear_page_dirty_for_io(fio.encrypted_page)) 574 dec_page_count(fio.sbi, F2FS_DIRTY_META); 575 576 set_page_writeback(fio.encrypted_page); 577 578 /* allocate block address */ 579 f2fs_wait_on_page_writeback(dn.node_page, NODE); 580 allocate_data_block(fio.sbi, NULL, fio.blk_addr, 581 &fio.blk_addr, &sum, CURSEG_COLD_DATA); 582 fio.rw = WRITE_SYNC; 583 f2fs_submit_page_mbio(&fio); 584 585 dn.data_blkaddr = fio.blk_addr; 586 set_data_blkaddr(&dn); 587 f2fs_update_extent_cache(&dn); 588 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE); 589 if (page->index == 0) 590 set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN); 591 put_page_out: 592 f2fs_put_page(fio.encrypted_page, 1); 593 put_out: 594 f2fs_put_dnode(&dn); 595 out: 596 f2fs_put_page(page, 1); 597 } 598 599 static void move_data_page(struct inode *inode, block_t bidx, int gc_type) 600 { 601 struct page *page; 602 603 page = get_lock_data_page(inode, bidx); 604 if (IS_ERR(page)) 605 return; 606 607 if (gc_type == BG_GC) { 608 if (PageWriteback(page)) 609 goto out; 610 set_page_dirty(page); 611 set_cold_data(page); 612 } else { 613 struct f2fs_io_info fio = { 614 .sbi = F2FS_I_SB(inode), 615 .type = DATA, 616 .rw = WRITE_SYNC, 617 .page = page, 618 .encrypted_page = NULL, 619 }; 620 set_page_dirty(page); 621 f2fs_wait_on_page_writeback(page, DATA); 622 if (clear_page_dirty_for_io(page)) 623 inode_dec_dirty_pages(inode); 624 set_cold_data(page); 625 do_write_data_page(&fio); 626 clear_cold_data(page); 627 } 628 out: 629 f2fs_put_page(page, 1); 630 } 631 632 /* 633 * This function tries to get parent node of victim data block, and identifies 634 * data block validity. If the block is valid, copy that with cold status and 635 * modify parent node. 636 * If the parent node is not valid or the data block address is different, 637 * the victim data block is ignored. 638 */ 639 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 640 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 641 { 642 struct super_block *sb = sbi->sb; 643 struct f2fs_summary *entry; 644 block_t start_addr; 645 int off; 646 int phase = 0; 647 648 start_addr = START_BLOCK(sbi, segno); 649 650 next_step: 651 entry = sum; 652 653 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 654 struct page *data_page; 655 struct inode *inode; 656 struct node_info dni; /* dnode info for the data */ 657 unsigned int ofs_in_node, nofs; 658 block_t start_bidx; 659 660 /* stop BG_GC if there is not enough free sections. */ 661 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 662 return; 663 664 if (check_valid_map(sbi, segno, off) == 0) 665 continue; 666 667 if (phase == 0) { 668 ra_node_page(sbi, le32_to_cpu(entry->nid)); 669 continue; 670 } 671 672 /* Get an inode by ino with checking validity */ 673 if (check_dnode(sbi, entry, &dni, start_addr + off, &nofs) == 0) 674 continue; 675 676 if (phase == 1) { 677 ra_node_page(sbi, dni.ino); 678 continue; 679 } 680 681 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 682 683 if (phase == 2) { 684 inode = f2fs_iget(sb, dni.ino); 685 if (IS_ERR(inode) || is_bad_inode(inode)) 686 continue; 687 688 /* if encrypted inode, let's go phase 3 */ 689 if (f2fs_encrypted_inode(inode) && 690 S_ISREG(inode->i_mode)) { 691 add_gc_inode(gc_list, inode); 692 continue; 693 } 694 695 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)); 696 data_page = get_read_data_page(inode, 697 start_bidx + ofs_in_node, READA); 698 if (IS_ERR(data_page)) { 699 iput(inode); 700 continue; 701 } 702 703 f2fs_put_page(data_page, 0); 704 add_gc_inode(gc_list, inode); 705 continue; 706 } 707 708 /* phase 3 */ 709 inode = find_gc_inode(gc_list, dni.ino); 710 if (inode) { 711 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)) 712 + ofs_in_node; 713 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) 714 move_encrypted_block(inode, start_bidx); 715 else 716 move_data_page(inode, start_bidx, gc_type); 717 stat_inc_data_blk_count(sbi, 1, gc_type); 718 } 719 } 720 721 if (++phase < 4) 722 goto next_step; 723 724 if (gc_type == FG_GC) { 725 f2fs_submit_merged_bio(sbi, DATA, WRITE); 726 727 /* 728 * In the case of FG_GC, it'd be better to reclaim this victim 729 * completely. 730 */ 731 if (get_valid_blocks(sbi, segno, 1) != 0) { 732 phase = 2; 733 goto next_step; 734 } 735 } 736 } 737 738 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 739 int gc_type) 740 { 741 struct sit_info *sit_i = SIT_I(sbi); 742 int ret; 743 744 mutex_lock(&sit_i->sentry_lock); 745 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 746 NO_CHECK_TYPE, LFS); 747 mutex_unlock(&sit_i->sentry_lock); 748 return ret; 749 } 750 751 static void do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, 752 struct gc_inode_list *gc_list, int gc_type) 753 { 754 struct page *sum_page; 755 struct f2fs_summary_block *sum; 756 struct blk_plug plug; 757 758 /* read segment summary of victim */ 759 sum_page = get_sum_page(sbi, segno); 760 761 blk_start_plug(&plug); 762 763 sum = page_address(sum_page); 764 765 /* 766 * this is to avoid deadlock: 767 * - lock_page(sum_page) - f2fs_replace_block 768 * - check_valid_map() - mutex_lock(sentry_lock) 769 * - mutex_lock(sentry_lock) - change_curseg() 770 * - lock_page(sum_page) 771 */ 772 unlock_page(sum_page); 773 774 switch (GET_SUM_TYPE((&sum->footer))) { 775 case SUM_TYPE_NODE: 776 gc_node_segment(sbi, sum->entries, segno, gc_type); 777 break; 778 case SUM_TYPE_DATA: 779 gc_data_segment(sbi, sum->entries, gc_list, segno, gc_type); 780 break; 781 } 782 blk_finish_plug(&plug); 783 784 stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type); 785 stat_inc_call_count(sbi->stat_info); 786 787 f2fs_put_page(sum_page, 0); 788 } 789 790 int f2fs_gc(struct f2fs_sb_info *sbi) 791 { 792 unsigned int segno, i; 793 int gc_type = BG_GC; 794 int nfree = 0; 795 int ret = -1; 796 struct cp_control cpc; 797 struct gc_inode_list gc_list = { 798 .ilist = LIST_HEAD_INIT(gc_list.ilist), 799 .iroot = RADIX_TREE_INIT(GFP_NOFS), 800 }; 801 802 cpc.reason = __get_cp_reason(sbi); 803 gc_more: 804 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) 805 goto stop; 806 if (unlikely(f2fs_cp_error(sbi))) 807 goto stop; 808 809 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) { 810 gc_type = FG_GC; 811 write_checkpoint(sbi, &cpc); 812 } 813 814 if (!__get_victim(sbi, &segno, gc_type)) 815 goto stop; 816 ret = 0; 817 818 /* readahead multi ssa blocks those have contiguous address */ 819 if (sbi->segs_per_sec > 1) 820 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec, 821 META_SSA); 822 823 for (i = 0; i < sbi->segs_per_sec; i++) 824 do_garbage_collect(sbi, segno + i, &gc_list, gc_type); 825 826 if (gc_type == FG_GC) { 827 sbi->cur_victim_sec = NULL_SEGNO; 828 nfree++; 829 WARN_ON(get_valid_blocks(sbi, segno, sbi->segs_per_sec)); 830 } 831 832 if (has_not_enough_free_secs(sbi, nfree)) 833 goto gc_more; 834 835 if (gc_type == FG_GC) 836 write_checkpoint(sbi, &cpc); 837 stop: 838 mutex_unlock(&sbi->gc_mutex); 839 840 put_gc_inode(&gc_list); 841 return ret; 842 } 843 844 void build_gc_manager(struct f2fs_sb_info *sbi) 845 { 846 DIRTY_I(sbi)->v_ops = &default_v_ops; 847 } 848