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 int 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 block_t start_addr; 400 int off; 401 402 start_addr = START_BLOCK(sbi, segno); 403 404 next_step: 405 entry = sum; 406 407 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 408 nid_t nid = le32_to_cpu(entry->nid); 409 struct page *node_page; 410 struct node_info ni; 411 412 /* stop BG_GC if there is not enough free sections. */ 413 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 414 return 0; 415 416 if (check_valid_map(sbi, segno, off) == 0) 417 continue; 418 419 if (initial) { 420 ra_node_page(sbi, nid); 421 continue; 422 } 423 node_page = get_node_page(sbi, nid); 424 if (IS_ERR(node_page)) 425 continue; 426 427 /* block may become invalid during get_node_page */ 428 if (check_valid_map(sbi, segno, off) == 0) { 429 f2fs_put_page(node_page, 1); 430 continue; 431 } 432 433 get_node_info(sbi, nid, &ni); 434 if (ni.blk_addr != start_addr + off) { 435 f2fs_put_page(node_page, 1); 436 continue; 437 } 438 439 /* set page dirty and write it */ 440 if (gc_type == FG_GC) { 441 f2fs_wait_on_page_writeback(node_page, NODE); 442 set_page_dirty(node_page); 443 } else { 444 if (!PageWriteback(node_page)) 445 set_page_dirty(node_page); 446 } 447 f2fs_put_page(node_page, 1); 448 stat_inc_node_blk_count(sbi, 1, gc_type); 449 } 450 451 if (initial) { 452 initial = false; 453 goto next_step; 454 } 455 456 if (gc_type == FG_GC) { 457 struct writeback_control wbc = { 458 .sync_mode = WB_SYNC_ALL, 459 .nr_to_write = LONG_MAX, 460 .for_reclaim = 0, 461 }; 462 sync_node_pages(sbi, 0, &wbc); 463 464 /* return 1 only if FG_GC succefully reclaimed one */ 465 if (get_valid_blocks(sbi, segno, 1) == 0) 466 return 1; 467 } 468 return 0; 469 } 470 471 /* 472 * Calculate start block index indicating the given node offset. 473 * Be careful, caller should give this node offset only indicating direct node 474 * blocks. If any node offsets, which point the other types of node blocks such 475 * as indirect or double indirect node blocks, are given, it must be a caller's 476 * bug. 477 */ 478 block_t start_bidx_of_node(unsigned int node_ofs, struct f2fs_inode_info *fi) 479 { 480 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4; 481 unsigned int bidx; 482 483 if (node_ofs == 0) 484 return 0; 485 486 if (node_ofs <= 2) { 487 bidx = node_ofs - 1; 488 } else if (node_ofs <= indirect_blks) { 489 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1); 490 bidx = node_ofs - 2 - dec; 491 } else { 492 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1); 493 bidx = node_ofs - 5 - dec; 494 } 495 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(fi); 496 } 497 498 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 499 struct node_info *dni, block_t blkaddr, unsigned int *nofs) 500 { 501 struct page *node_page; 502 nid_t nid; 503 unsigned int ofs_in_node; 504 block_t source_blkaddr; 505 506 nid = le32_to_cpu(sum->nid); 507 ofs_in_node = le16_to_cpu(sum->ofs_in_node); 508 509 node_page = get_node_page(sbi, nid); 510 if (IS_ERR(node_page)) 511 return false; 512 513 get_node_info(sbi, nid, dni); 514 515 if (sum->version != dni->version) { 516 f2fs_put_page(node_page, 1); 517 return false; 518 } 519 520 *nofs = ofs_of_node(node_page); 521 source_blkaddr = datablock_addr(node_page, ofs_in_node); 522 f2fs_put_page(node_page, 1); 523 524 if (source_blkaddr != blkaddr) 525 return false; 526 return true; 527 } 528 529 static void move_encrypted_block(struct inode *inode, block_t bidx) 530 { 531 struct f2fs_io_info fio = { 532 .sbi = F2FS_I_SB(inode), 533 .type = DATA, 534 .rw = READ_SYNC, 535 .encrypted_page = NULL, 536 }; 537 struct dnode_of_data dn; 538 struct f2fs_summary sum; 539 struct node_info ni; 540 struct page *page; 541 int err; 542 543 /* do not read out */ 544 page = grab_cache_page(inode->i_mapping, bidx); 545 if (!page) 546 return; 547 548 set_new_dnode(&dn, inode, NULL, NULL, 0); 549 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE); 550 if (err) 551 goto out; 552 553 if (unlikely(dn.data_blkaddr == NULL_ADDR)) 554 goto put_out; 555 556 get_node_info(fio.sbi, dn.nid, &ni); 557 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version); 558 559 /* read page */ 560 fio.page = page; 561 fio.blk_addr = dn.data_blkaddr; 562 563 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), 564 fio.blk_addr, 565 FGP_LOCK|FGP_CREAT, 566 GFP_NOFS); 567 if (!fio.encrypted_page) 568 goto put_out; 569 570 err = f2fs_submit_page_bio(&fio); 571 if (err) 572 goto put_page_out; 573 574 /* write page */ 575 lock_page(fio.encrypted_page); 576 577 if (unlikely(!PageUptodate(fio.encrypted_page))) 578 goto put_page_out; 579 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) 580 goto put_page_out; 581 582 set_page_dirty(fio.encrypted_page); 583 f2fs_wait_on_page_writeback(fio.encrypted_page, META); 584 if (clear_page_dirty_for_io(fio.encrypted_page)) 585 dec_page_count(fio.sbi, F2FS_DIRTY_META); 586 587 set_page_writeback(fio.encrypted_page); 588 589 /* allocate block address */ 590 f2fs_wait_on_page_writeback(dn.node_page, NODE); 591 allocate_data_block(fio.sbi, NULL, fio.blk_addr, 592 &fio.blk_addr, &sum, CURSEG_COLD_DATA); 593 fio.rw = WRITE_SYNC; 594 f2fs_submit_page_mbio(&fio); 595 596 dn.data_blkaddr = fio.blk_addr; 597 set_data_blkaddr(&dn); 598 f2fs_update_extent_cache(&dn); 599 set_inode_flag(F2FS_I(inode), FI_APPEND_WRITE); 600 if (page->index == 0) 601 set_inode_flag(F2FS_I(inode), FI_FIRST_BLOCK_WRITTEN); 602 put_page_out: 603 f2fs_put_page(fio.encrypted_page, 1); 604 put_out: 605 f2fs_put_dnode(&dn); 606 out: 607 f2fs_put_page(page, 1); 608 } 609 610 static void move_data_page(struct inode *inode, block_t bidx, int gc_type) 611 { 612 struct page *page; 613 614 page = get_lock_data_page(inode, bidx); 615 if (IS_ERR(page)) 616 return; 617 618 if (gc_type == BG_GC) { 619 if (PageWriteback(page)) 620 goto out; 621 set_page_dirty(page); 622 set_cold_data(page); 623 } else { 624 struct f2fs_io_info fio = { 625 .sbi = F2FS_I_SB(inode), 626 .type = DATA, 627 .rw = WRITE_SYNC, 628 .page = page, 629 .encrypted_page = NULL, 630 }; 631 set_page_dirty(page); 632 f2fs_wait_on_page_writeback(page, DATA); 633 if (clear_page_dirty_for_io(page)) 634 inode_dec_dirty_pages(inode); 635 set_cold_data(page); 636 do_write_data_page(&fio); 637 clear_cold_data(page); 638 } 639 out: 640 f2fs_put_page(page, 1); 641 } 642 643 /* 644 * This function tries to get parent node of victim data block, and identifies 645 * data block validity. If the block is valid, copy that with cold status and 646 * modify parent node. 647 * If the parent node is not valid or the data block address is different, 648 * the victim data block is ignored. 649 */ 650 static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum, 651 struct gc_inode_list *gc_list, unsigned int segno, int gc_type) 652 { 653 struct super_block *sb = sbi->sb; 654 struct f2fs_summary *entry; 655 block_t start_addr; 656 int off; 657 int phase = 0; 658 659 start_addr = START_BLOCK(sbi, segno); 660 661 next_step: 662 entry = sum; 663 664 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) { 665 struct page *data_page; 666 struct inode *inode; 667 struct node_info dni; /* dnode info for the data */ 668 unsigned int ofs_in_node, nofs; 669 block_t start_bidx; 670 671 /* stop BG_GC if there is not enough free sections. */ 672 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0)) 673 return 0; 674 675 if (check_valid_map(sbi, segno, off) == 0) 676 continue; 677 678 if (phase == 0) { 679 ra_node_page(sbi, le32_to_cpu(entry->nid)); 680 continue; 681 } 682 683 /* Get an inode by ino with checking validity */ 684 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs)) 685 continue; 686 687 if (phase == 1) { 688 ra_node_page(sbi, dni.ino); 689 continue; 690 } 691 692 ofs_in_node = le16_to_cpu(entry->ofs_in_node); 693 694 if (phase == 2) { 695 inode = f2fs_iget(sb, dni.ino); 696 if (IS_ERR(inode) || is_bad_inode(inode)) 697 continue; 698 699 /* if encrypted inode, let's go phase 3 */ 700 if (f2fs_encrypted_inode(inode) && 701 S_ISREG(inode->i_mode)) { 702 add_gc_inode(gc_list, inode); 703 continue; 704 } 705 706 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)); 707 data_page = get_read_data_page(inode, 708 start_bidx + ofs_in_node, READA); 709 if (IS_ERR(data_page)) { 710 iput(inode); 711 continue; 712 } 713 714 f2fs_put_page(data_page, 0); 715 add_gc_inode(gc_list, inode); 716 continue; 717 } 718 719 /* phase 3 */ 720 inode = find_gc_inode(gc_list, dni.ino); 721 if (inode) { 722 start_bidx = start_bidx_of_node(nofs, F2FS_I(inode)) 723 + ofs_in_node; 724 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode)) 725 move_encrypted_block(inode, start_bidx); 726 else 727 move_data_page(inode, start_bidx, gc_type); 728 stat_inc_data_blk_count(sbi, 1, gc_type); 729 } 730 } 731 732 if (++phase < 4) 733 goto next_step; 734 735 if (gc_type == FG_GC) { 736 f2fs_submit_merged_bio(sbi, DATA, WRITE); 737 738 /* return 1 only if FG_GC succefully reclaimed one */ 739 if (get_valid_blocks(sbi, segno, 1) == 0) 740 return 1; 741 } 742 return 0; 743 } 744 745 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim, 746 int gc_type) 747 { 748 struct sit_info *sit_i = SIT_I(sbi); 749 int ret; 750 751 mutex_lock(&sit_i->sentry_lock); 752 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, 753 NO_CHECK_TYPE, LFS); 754 mutex_unlock(&sit_i->sentry_lock); 755 return ret; 756 } 757 758 static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno, 759 struct gc_inode_list *gc_list, int gc_type) 760 { 761 struct page *sum_page; 762 struct f2fs_summary_block *sum; 763 struct blk_plug plug; 764 int nfree = 0; 765 766 /* read segment summary of victim */ 767 sum_page = get_sum_page(sbi, segno); 768 769 blk_start_plug(&plug); 770 771 sum = page_address(sum_page); 772 773 /* 774 * this is to avoid deadlock: 775 * - lock_page(sum_page) - f2fs_replace_block 776 * - check_valid_map() - mutex_lock(sentry_lock) 777 * - mutex_lock(sentry_lock) - change_curseg() 778 * - lock_page(sum_page) 779 */ 780 unlock_page(sum_page); 781 782 switch (GET_SUM_TYPE((&sum->footer))) { 783 case SUM_TYPE_NODE: 784 nfree = gc_node_segment(sbi, sum->entries, segno, gc_type); 785 break; 786 case SUM_TYPE_DATA: 787 nfree = gc_data_segment(sbi, sum->entries, gc_list, 788 segno, gc_type); 789 break; 790 } 791 blk_finish_plug(&plug); 792 793 stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)), gc_type); 794 stat_inc_call_count(sbi->stat_info); 795 796 f2fs_put_page(sum_page, 0); 797 return nfree; 798 } 799 800 int f2fs_gc(struct f2fs_sb_info *sbi) 801 { 802 unsigned int segno = NULL_SEGNO; 803 unsigned int i; 804 int gc_type = BG_GC; 805 int nfree = 0; 806 int ret = -1; 807 struct cp_control cpc; 808 struct gc_inode_list gc_list = { 809 .ilist = LIST_HEAD_INIT(gc_list.ilist), 810 .iroot = RADIX_TREE_INIT(GFP_NOFS), 811 }; 812 813 cpc.reason = __get_cp_reason(sbi); 814 gc_more: 815 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) 816 goto stop; 817 if (unlikely(f2fs_cp_error(sbi))) 818 goto stop; 819 820 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, nfree)) { 821 gc_type = FG_GC; 822 if (__get_victim(sbi, &segno, gc_type) || prefree_segments(sbi)) 823 write_checkpoint(sbi, &cpc); 824 } 825 826 if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type)) 827 goto stop; 828 ret = 0; 829 830 /* readahead multi ssa blocks those have contiguous address */ 831 if (sbi->segs_per_sec > 1) 832 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno), sbi->segs_per_sec, 833 META_SSA); 834 835 for (i = 0; i < sbi->segs_per_sec; i++) 836 nfree += do_garbage_collect(sbi, segno + i, &gc_list, gc_type); 837 838 if (gc_type == FG_GC) 839 sbi->cur_victim_sec = NULL_SEGNO; 840 841 if (has_not_enough_free_secs(sbi, nfree)) 842 goto gc_more; 843 844 if (gc_type == FG_GC) 845 write_checkpoint(sbi, &cpc); 846 stop: 847 mutex_unlock(&sbi->gc_mutex); 848 849 put_gc_inode(&gc_list); 850 return ret; 851 } 852 853 void build_gc_manager(struct f2fs_sb_info *sbi) 854 { 855 DIRTY_I(sbi)->v_ops = &default_v_ops; 856 } 857