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
gc_thread_func(void * data)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 unsigned int wait_ms;
32
33 wait_ms = gc_th->min_sleep_time;
34
35 set_freezable();
36 do {
37 wait_event_interruptible_timeout(*wq,
38 kthread_should_stop() || freezing(current) ||
39 gc_th->gc_wake,
40 msecs_to_jiffies(wait_ms));
41
42 /* give it a try one time */
43 if (gc_th->gc_wake)
44 gc_th->gc_wake = 0;
45
46 if (try_to_freeze())
47 continue;
48 if (kthread_should_stop())
49 break;
50
51 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
52 increase_sleep_time(gc_th, &wait_ms);
53 continue;
54 }
55
56 #ifdef CONFIG_F2FS_FAULT_INJECTION
57 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
58 f2fs_show_injection_info(FAULT_CHECKPOINT);
59 f2fs_stop_checkpoint(sbi, false);
60 }
61 #endif
62
63 if (!sb_start_write_trylock(sbi->sb))
64 continue;
65
66 /*
67 * [GC triggering condition]
68 * 0. GC is not conducted currently.
69 * 1. There are enough dirty segments.
70 * 2. IO subsystem is idle by checking the # of writeback pages.
71 * 3. IO subsystem is idle by checking the # of requests in
72 * bdev's request list.
73 *
74 * Note) We have to avoid triggering GCs frequently.
75 * Because it is possible that some segments can be
76 * invalidated soon after by user update or deletion.
77 * So, I'd like to wait some time to collect dirty segments.
78 */
79 if (gc_th->gc_urgent) {
80 wait_ms = gc_th->urgent_sleep_time;
81 mutex_lock(&sbi->gc_mutex);
82 goto do_gc;
83 }
84
85 if (!mutex_trylock(&sbi->gc_mutex))
86 goto next;
87
88 if (!is_idle(sbi)) {
89 increase_sleep_time(gc_th, &wait_ms);
90 mutex_unlock(&sbi->gc_mutex);
91 goto next;
92 }
93
94 if (has_enough_invalid_blocks(sbi))
95 decrease_sleep_time(gc_th, &wait_ms);
96 else
97 increase_sleep_time(gc_th, &wait_ms);
98 do_gc:
99 stat_inc_bggc_count(sbi);
100
101 /* if return value is not zero, no victim was selected */
102 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
103 wait_ms = gc_th->no_gc_sleep_time;
104
105 trace_f2fs_background_gc(sbi->sb, wait_ms,
106 prefree_segments(sbi), free_segments(sbi));
107
108 /* balancing f2fs's metadata periodically */
109 f2fs_balance_fs_bg(sbi);
110 next:
111 sb_end_write(sbi->sb);
112
113 } while (!kthread_should_stop());
114 return 0;
115 }
116
start_gc_thread(struct f2fs_sb_info * sbi)117 int start_gc_thread(struct f2fs_sb_info *sbi)
118 {
119 struct f2fs_gc_kthread *gc_th;
120 dev_t dev = sbi->sb->s_bdev->bd_dev;
121 int err = 0;
122
123 gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
124 if (!gc_th) {
125 err = -ENOMEM;
126 goto out;
127 }
128
129 gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
130 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
131 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
132 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
133
134 gc_th->gc_idle = 0;
135 gc_th->gc_urgent = 0;
136 gc_th->gc_wake= 0;
137
138 sbi->gc_thread = gc_th;
139 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
140 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
141 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
142 if (IS_ERR(gc_th->f2fs_gc_task)) {
143 err = PTR_ERR(gc_th->f2fs_gc_task);
144 kfree(gc_th);
145 sbi->gc_thread = NULL;
146 }
147 out:
148 return err;
149 }
150
stop_gc_thread(struct f2fs_sb_info * sbi)151 void stop_gc_thread(struct f2fs_sb_info *sbi)
152 {
153 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
154 if (!gc_th)
155 return;
156 kthread_stop(gc_th->f2fs_gc_task);
157 kfree(gc_th);
158 sbi->gc_thread = NULL;
159 }
160
select_gc_type(struct f2fs_gc_kthread * gc_th,int gc_type)161 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
162 {
163 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
164
165 if (!gc_th)
166 return gc_mode;
167
168 if (gc_th->gc_idle) {
169 if (gc_th->gc_idle == 1)
170 gc_mode = GC_CB;
171 else if (gc_th->gc_idle == 2)
172 gc_mode = GC_GREEDY;
173 }
174 if (gc_th->gc_urgent)
175 gc_mode = GC_GREEDY;
176 return gc_mode;
177 }
178
select_policy(struct f2fs_sb_info * sbi,int gc_type,int type,struct victim_sel_policy * p)179 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
180 int type, struct victim_sel_policy *p)
181 {
182 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
183
184 if (p->alloc_mode == SSR) {
185 p->gc_mode = GC_GREEDY;
186 p->dirty_segmap = dirty_i->dirty_segmap[type];
187 p->max_search = dirty_i->nr_dirty[type];
188 p->ofs_unit = 1;
189 } else {
190 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
191 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
192 p->max_search = dirty_i->nr_dirty[DIRTY];
193 p->ofs_unit = sbi->segs_per_sec;
194 }
195
196 /* we need to check every dirty segments in the FG_GC case */
197 if (gc_type != FG_GC &&
198 (sbi->gc_thread && !sbi->gc_thread->gc_urgent) &&
199 p->max_search > sbi->max_victim_search)
200 p->max_search = sbi->max_victim_search;
201
202 /* let's select beginning hot/small space first in no_heap mode*/
203 if (test_opt(sbi, NOHEAP) &&
204 (type == CURSEG_HOT_DATA || IS_NODESEG(type)))
205 p->offset = 0;
206 else
207 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
208 }
209
get_max_cost(struct f2fs_sb_info * sbi,struct victim_sel_policy * p)210 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
211 struct victim_sel_policy *p)
212 {
213 /* SSR allocates in a segment unit */
214 if (p->alloc_mode == SSR)
215 return sbi->blocks_per_seg;
216 if (p->gc_mode == GC_GREEDY)
217 return 2 * sbi->blocks_per_seg * p->ofs_unit;
218 else if (p->gc_mode == GC_CB)
219 return UINT_MAX;
220 else /* No other gc_mode */
221 return 0;
222 }
223
check_bg_victims(struct f2fs_sb_info * sbi)224 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
225 {
226 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
227 unsigned int secno;
228
229 /*
230 * If the gc_type is FG_GC, we can select victim segments
231 * selected by background GC before.
232 * Those segments guarantee they have small valid blocks.
233 */
234 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
235 if (sec_usage_check(sbi, secno))
236 continue;
237
238 if (no_fggc_candidate(sbi, secno))
239 continue;
240
241 clear_bit(secno, dirty_i->victim_secmap);
242 return GET_SEG_FROM_SEC(sbi, secno);
243 }
244 return NULL_SEGNO;
245 }
246
get_cb_cost(struct f2fs_sb_info * sbi,unsigned int segno)247 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
248 {
249 struct sit_info *sit_i = SIT_I(sbi);
250 unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
251 unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
252 unsigned long long mtime = 0;
253 unsigned int vblocks;
254 unsigned char age = 0;
255 unsigned char u;
256 unsigned int i;
257
258 for (i = 0; i < sbi->segs_per_sec; i++)
259 mtime += get_seg_entry(sbi, start + i)->mtime;
260 vblocks = get_valid_blocks(sbi, segno, true);
261
262 mtime = div_u64(mtime, sbi->segs_per_sec);
263 vblocks = div_u64(vblocks, sbi->segs_per_sec);
264
265 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
266
267 /* Handle if the system time has changed by the user */
268 if (mtime < sit_i->min_mtime)
269 sit_i->min_mtime = mtime;
270 if (mtime > sit_i->max_mtime)
271 sit_i->max_mtime = mtime;
272 if (sit_i->max_mtime != sit_i->min_mtime)
273 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
274 sit_i->max_mtime - sit_i->min_mtime);
275
276 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
277 }
278
get_gc_cost(struct f2fs_sb_info * sbi,unsigned int segno,struct victim_sel_policy * p)279 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
280 unsigned int segno, struct victim_sel_policy *p)
281 {
282 if (p->alloc_mode == SSR)
283 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
284
285 /* alloc_mode == LFS */
286 if (p->gc_mode == GC_GREEDY)
287 return get_valid_blocks(sbi, segno, true);
288 else
289 return get_cb_cost(sbi, segno);
290 }
291
count_bits(const unsigned long * addr,unsigned int offset,unsigned int len)292 static unsigned int count_bits(const unsigned long *addr,
293 unsigned int offset, unsigned int len)
294 {
295 unsigned int end = offset + len, sum = 0;
296
297 while (offset < end) {
298 if (test_bit(offset++, addr))
299 ++sum;
300 }
301 return sum;
302 }
303
304 /*
305 * This function is called from two paths.
306 * One is garbage collection and the other is SSR segment selection.
307 * When it is called during GC, it just gets a victim segment
308 * and it does not remove it from dirty seglist.
309 * When it is called from SSR segment selection, it finds a segment
310 * which has minimum valid blocks and removes it from dirty seglist.
311 */
get_victim_by_default(struct f2fs_sb_info * sbi,unsigned int * result,int gc_type,int type,char alloc_mode)312 static int get_victim_by_default(struct f2fs_sb_info *sbi,
313 unsigned int *result, int gc_type, int type, char alloc_mode)
314 {
315 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
316 struct sit_info *sm = SIT_I(sbi);
317 struct victim_sel_policy p;
318 unsigned int secno, last_victim;
319 unsigned int last_segment = MAIN_SEGS(sbi);
320 unsigned int nsearched = 0;
321
322 mutex_lock(&dirty_i->seglist_lock);
323
324 p.alloc_mode = alloc_mode;
325 select_policy(sbi, gc_type, type, &p);
326
327 p.min_segno = NULL_SEGNO;
328 p.min_cost = get_max_cost(sbi, &p);
329
330 if (*result != NULL_SEGNO) {
331 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) &&
332 get_valid_blocks(sbi, *result, false) &&
333 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
334 p.min_segno = *result;
335 goto out;
336 }
337
338 if (p.max_search == 0)
339 goto out;
340
341 last_victim = sm->last_victim[p.gc_mode];
342 if (p.alloc_mode == LFS && gc_type == FG_GC) {
343 p.min_segno = check_bg_victims(sbi);
344 if (p.min_segno != NULL_SEGNO)
345 goto got_it;
346 }
347
348 while (1) {
349 unsigned long cost;
350 unsigned int segno;
351
352 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
353 if (segno >= last_segment) {
354 if (sm->last_victim[p.gc_mode]) {
355 last_segment =
356 sm->last_victim[p.gc_mode];
357 sm->last_victim[p.gc_mode] = 0;
358 p.offset = 0;
359 continue;
360 }
361 break;
362 }
363
364 p.offset = segno + p.ofs_unit;
365 if (p.ofs_unit > 1) {
366 p.offset -= segno % p.ofs_unit;
367 nsearched += count_bits(p.dirty_segmap,
368 p.offset - p.ofs_unit,
369 p.ofs_unit);
370 } else {
371 nsearched++;
372 }
373
374 secno = GET_SEC_FROM_SEG(sbi, segno);
375
376 if (sec_usage_check(sbi, secno))
377 goto next;
378 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
379 goto next;
380 if (gc_type == FG_GC && p.alloc_mode == LFS &&
381 no_fggc_candidate(sbi, secno))
382 goto next;
383
384 cost = get_gc_cost(sbi, segno, &p);
385
386 if (p.min_cost > cost) {
387 p.min_segno = segno;
388 p.min_cost = cost;
389 }
390 next:
391 if (nsearched >= p.max_search) {
392 if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
393 sm->last_victim[p.gc_mode] = last_victim + 1;
394 else
395 sm->last_victim[p.gc_mode] = segno + 1;
396 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
397 break;
398 }
399 }
400 if (p.min_segno != NULL_SEGNO) {
401 got_it:
402 if (p.alloc_mode == LFS) {
403 secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
404 if (gc_type == FG_GC)
405 sbi->cur_victim_sec = secno;
406 else
407 set_bit(secno, dirty_i->victim_secmap);
408 }
409 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
410
411 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
412 sbi->cur_victim_sec,
413 prefree_segments(sbi), free_segments(sbi));
414 }
415 out:
416 mutex_unlock(&dirty_i->seglist_lock);
417
418 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
419 }
420
421 static const struct victim_selection default_v_ops = {
422 .get_victim = get_victim_by_default,
423 };
424
find_gc_inode(struct gc_inode_list * gc_list,nid_t ino)425 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
426 {
427 struct inode_entry *ie;
428
429 ie = radix_tree_lookup(&gc_list->iroot, ino);
430 if (ie)
431 return ie->inode;
432 return NULL;
433 }
434
add_gc_inode(struct gc_inode_list * gc_list,struct inode * inode)435 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
436 {
437 struct inode_entry *new_ie;
438
439 if (inode == find_gc_inode(gc_list, inode->i_ino)) {
440 iput(inode);
441 return;
442 }
443 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
444 new_ie->inode = inode;
445
446 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
447 list_add_tail(&new_ie->list, &gc_list->ilist);
448 }
449
put_gc_inode(struct gc_inode_list * gc_list)450 static void put_gc_inode(struct gc_inode_list *gc_list)
451 {
452 struct inode_entry *ie, *next_ie;
453 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
454 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
455 iput(ie->inode);
456 list_del(&ie->list);
457 kmem_cache_free(inode_entry_slab, ie);
458 }
459 }
460
check_valid_map(struct f2fs_sb_info * sbi,unsigned int segno,int offset)461 static int check_valid_map(struct f2fs_sb_info *sbi,
462 unsigned int segno, int offset)
463 {
464 struct sit_info *sit_i = SIT_I(sbi);
465 struct seg_entry *sentry;
466 int ret;
467
468 down_read(&sit_i->sentry_lock);
469 sentry = get_seg_entry(sbi, segno);
470 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
471 up_read(&sit_i->sentry_lock);
472 return ret;
473 }
474
475 /*
476 * This function compares node address got in summary with that in NAT.
477 * On validity, copy that node with cold status, otherwise (invalid node)
478 * ignore that.
479 */
gc_node_segment(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,unsigned int segno,int gc_type)480 static void gc_node_segment(struct f2fs_sb_info *sbi,
481 struct f2fs_summary *sum, unsigned int segno, int gc_type)
482 {
483 struct f2fs_summary *entry;
484 block_t start_addr;
485 int off;
486 int phase = 0;
487
488 start_addr = START_BLOCK(sbi, segno);
489
490 next_step:
491 entry = sum;
492
493 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
494 nid_t nid = le32_to_cpu(entry->nid);
495 struct page *node_page;
496 struct node_info ni;
497
498 /* stop BG_GC if there is not enough free sections. */
499 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
500 return;
501
502 if (check_valid_map(sbi, segno, off) == 0)
503 continue;
504
505 if (phase == 0) {
506 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
507 META_NAT, true);
508 continue;
509 }
510
511 if (phase == 1) {
512 ra_node_page(sbi, nid);
513 continue;
514 }
515
516 /* phase == 2 */
517 node_page = get_node_page(sbi, nid);
518 if (IS_ERR(node_page))
519 continue;
520
521 /* block may become invalid during get_node_page */
522 if (check_valid_map(sbi, segno, off) == 0) {
523 f2fs_put_page(node_page, 1);
524 continue;
525 }
526
527 get_node_info(sbi, nid, &ni);
528 if (ni.blk_addr != start_addr + off) {
529 f2fs_put_page(node_page, 1);
530 continue;
531 }
532
533 move_node_page(node_page, gc_type);
534 stat_inc_node_blk_count(sbi, 1, gc_type);
535 }
536
537 if (++phase < 3)
538 goto next_step;
539 }
540
541 /*
542 * Calculate start block index indicating the given node offset.
543 * Be careful, caller should give this node offset only indicating direct node
544 * blocks. If any node offsets, which point the other types of node blocks such
545 * as indirect or double indirect node blocks, are given, it must be a caller's
546 * bug.
547 */
start_bidx_of_node(unsigned int node_ofs,struct inode * inode)548 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
549 {
550 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
551 unsigned int bidx;
552
553 if (node_ofs == 0)
554 return 0;
555
556 if (node_ofs <= 2) {
557 bidx = node_ofs - 1;
558 } else if (node_ofs <= indirect_blks) {
559 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
560 bidx = node_ofs - 2 - dec;
561 } else {
562 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
563 bidx = node_ofs - 5 - dec;
564 }
565 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
566 }
567
is_alive(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,struct node_info * dni,block_t blkaddr,unsigned int * nofs)568 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
569 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
570 {
571 struct page *node_page;
572 nid_t nid;
573 unsigned int ofs_in_node;
574 block_t source_blkaddr;
575
576 nid = le32_to_cpu(sum->nid);
577 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
578
579 node_page = get_node_page(sbi, nid);
580 if (IS_ERR(node_page))
581 return false;
582
583 get_node_info(sbi, nid, dni);
584
585 if (sum->version != dni->version) {
586 f2fs_msg(sbi->sb, KERN_WARNING,
587 "%s: valid data with mismatched node version.",
588 __func__);
589 set_sbi_flag(sbi, SBI_NEED_FSCK);
590 }
591
592 *nofs = ofs_of_node(node_page);
593 source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
594 f2fs_put_page(node_page, 1);
595
596 if (source_blkaddr != blkaddr)
597 return false;
598 return true;
599 }
600
601 /*
602 * Move data block via META_MAPPING while keeping locked data page.
603 * This can be used to move blocks, aka LBAs, directly on disk.
604 */
move_data_block(struct inode * inode,block_t bidx,unsigned int segno,int off)605 static void move_data_block(struct inode *inode, block_t bidx,
606 unsigned int segno, int off)
607 {
608 struct f2fs_io_info fio = {
609 .sbi = F2FS_I_SB(inode),
610 .ino = inode->i_ino,
611 .type = DATA,
612 .temp = COLD,
613 .op = REQ_OP_READ,
614 .op_flags = 0,
615 .encrypted_page = NULL,
616 .in_list = false,
617 };
618 struct dnode_of_data dn;
619 struct f2fs_summary sum;
620 struct node_info ni;
621 struct page *page;
622 block_t newaddr;
623 int err;
624
625 /* do not read out */
626 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
627 if (!page)
628 return;
629
630 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
631 goto out;
632
633 if (f2fs_is_atomic_file(inode))
634 goto out;
635
636 if (f2fs_is_pinned_file(inode)) {
637 f2fs_pin_file_control(inode, true);
638 goto out;
639 }
640
641 set_new_dnode(&dn, inode, NULL, NULL, 0);
642 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
643 if (err)
644 goto out;
645
646 if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
647 ClearPageUptodate(page);
648 goto put_out;
649 }
650
651 /*
652 * don't cache encrypted data into meta inode until previous dirty
653 * data were writebacked to avoid racing between GC and flush.
654 */
655 f2fs_wait_on_page_writeback(page, DATA, true);
656
657 get_node_info(fio.sbi, dn.nid, &ni);
658 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
659
660 /* read page */
661 fio.page = page;
662 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
663
664 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
665 &sum, CURSEG_COLD_DATA, NULL, false);
666
667 fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
668 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
669 if (!fio.encrypted_page) {
670 err = -ENOMEM;
671 goto recover_block;
672 }
673
674 err = f2fs_submit_page_bio(&fio);
675 if (err)
676 goto put_page_out;
677
678 /* write page */
679 lock_page(fio.encrypted_page);
680
681 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
682 err = -EIO;
683 goto put_page_out;
684 }
685 if (unlikely(!PageUptodate(fio.encrypted_page))) {
686 err = -EIO;
687 goto put_page_out;
688 }
689
690 set_page_dirty(fio.encrypted_page);
691 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
692 if (clear_page_dirty_for_io(fio.encrypted_page))
693 dec_page_count(fio.sbi, F2FS_DIRTY_META);
694
695 set_page_writeback(fio.encrypted_page);
696
697 /* allocate block address */
698 f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
699
700 fio.op = REQ_OP_WRITE;
701 fio.op_flags = REQ_SYNC;
702 fio.new_blkaddr = newaddr;
703 err = f2fs_submit_page_write(&fio);
704 if (err) {
705 if (PageWriteback(fio.encrypted_page))
706 end_page_writeback(fio.encrypted_page);
707 goto put_page_out;
708 }
709
710 f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
711
712 f2fs_update_data_blkaddr(&dn, newaddr);
713 set_inode_flag(inode, FI_APPEND_WRITE);
714 if (page->index == 0)
715 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
716 put_page_out:
717 f2fs_put_page(fio.encrypted_page, 1);
718 recover_block:
719 if (err)
720 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
721 true, true);
722 put_out:
723 f2fs_put_dnode(&dn);
724 out:
725 f2fs_put_page(page, 1);
726 }
727
move_data_page(struct inode * inode,block_t bidx,int gc_type,unsigned int segno,int off)728 static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
729 unsigned int segno, int off)
730 {
731 struct page *page;
732
733 page = get_lock_data_page(inode, bidx, true);
734 if (IS_ERR(page))
735 return;
736
737 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
738 goto out;
739
740 if (f2fs_is_atomic_file(inode))
741 goto out;
742 if (f2fs_is_pinned_file(inode)) {
743 if (gc_type == FG_GC)
744 f2fs_pin_file_control(inode, true);
745 goto out;
746 }
747
748 if (gc_type == BG_GC) {
749 if (PageWriteback(page))
750 goto out;
751 set_page_dirty(page);
752 set_cold_data(page);
753 } else {
754 struct f2fs_io_info fio = {
755 .sbi = F2FS_I_SB(inode),
756 .ino = inode->i_ino,
757 .type = DATA,
758 .temp = COLD,
759 .op = REQ_OP_WRITE,
760 .op_flags = REQ_SYNC,
761 .old_blkaddr = NULL_ADDR,
762 .page = page,
763 .encrypted_page = NULL,
764 .need_lock = LOCK_REQ,
765 .io_type = FS_GC_DATA_IO,
766 };
767 bool is_dirty = PageDirty(page);
768 int err;
769
770 retry:
771 set_page_dirty(page);
772 f2fs_wait_on_page_writeback(page, DATA, true);
773 if (clear_page_dirty_for_io(page)) {
774 inode_dec_dirty_pages(inode);
775 remove_dirty_inode(inode);
776 }
777
778 set_cold_data(page);
779
780 err = do_write_data_page(&fio);
781 if (err == -ENOMEM && is_dirty) {
782 congestion_wait(BLK_RW_ASYNC, HZ/50);
783 goto retry;
784 }
785 }
786 out:
787 f2fs_put_page(page, 1);
788 }
789
790 /*
791 * This function tries to get parent node of victim data block, and identifies
792 * data block validity. If the block is valid, copy that with cold status and
793 * modify parent node.
794 * If the parent node is not valid or the data block address is different,
795 * the victim data block is ignored.
796 */
gc_data_segment(struct f2fs_sb_info * sbi,struct f2fs_summary * sum,struct gc_inode_list * gc_list,unsigned int segno,int gc_type)797 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
798 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
799 {
800 struct super_block *sb = sbi->sb;
801 struct f2fs_summary *entry;
802 block_t start_addr;
803 int off;
804 int phase = 0;
805
806 start_addr = START_BLOCK(sbi, segno);
807
808 next_step:
809 entry = sum;
810
811 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
812 struct page *data_page;
813 struct inode *inode;
814 struct node_info dni; /* dnode info for the data */
815 unsigned int ofs_in_node, nofs;
816 block_t start_bidx;
817 nid_t nid = le32_to_cpu(entry->nid);
818
819 /* stop BG_GC if there is not enough free sections. */
820 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
821 return;
822
823 if (check_valid_map(sbi, segno, off) == 0)
824 continue;
825
826 if (phase == 0) {
827 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
828 META_NAT, true);
829 continue;
830 }
831
832 if (phase == 1) {
833 ra_node_page(sbi, nid);
834 continue;
835 }
836
837 /* Get an inode by ino with checking validity */
838 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
839 continue;
840
841 if (phase == 2) {
842 ra_node_page(sbi, dni.ino);
843 continue;
844 }
845
846 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
847
848 if (phase == 3) {
849 inode = f2fs_iget(sb, dni.ino);
850 if (IS_ERR(inode) || is_bad_inode(inode))
851 continue;
852
853 /* if inode uses special I/O path, let's go phase 3 */
854 if (f2fs_post_read_required(inode)) {
855 add_gc_inode(gc_list, inode);
856 continue;
857 }
858
859 if (!down_write_trylock(
860 &F2FS_I(inode)->dio_rwsem[WRITE])) {
861 iput(inode);
862 continue;
863 }
864
865 start_bidx = start_bidx_of_node(nofs, inode);
866 data_page = get_read_data_page(inode,
867 start_bidx + ofs_in_node, REQ_RAHEAD,
868 true);
869 up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
870 if (IS_ERR(data_page)) {
871 iput(inode);
872 continue;
873 }
874
875 f2fs_put_page(data_page, 0);
876 add_gc_inode(gc_list, inode);
877 continue;
878 }
879
880 /* phase 4 */
881 inode = find_gc_inode(gc_list, dni.ino);
882 if (inode) {
883 struct f2fs_inode_info *fi = F2FS_I(inode);
884 bool locked = false;
885
886 if (S_ISREG(inode->i_mode)) {
887 if (!down_write_trylock(&fi->dio_rwsem[READ]))
888 continue;
889 if (!down_write_trylock(
890 &fi->dio_rwsem[WRITE])) {
891 up_write(&fi->dio_rwsem[READ]);
892 continue;
893 }
894 locked = true;
895
896 /* wait for all inflight aio data */
897 inode_dio_wait(inode);
898 }
899
900 start_bidx = start_bidx_of_node(nofs, inode)
901 + ofs_in_node;
902 if (f2fs_post_read_required(inode))
903 move_data_block(inode, start_bidx, segno, off);
904 else
905 move_data_page(inode, start_bidx, gc_type,
906 segno, off);
907
908 if (locked) {
909 up_write(&fi->dio_rwsem[WRITE]);
910 up_write(&fi->dio_rwsem[READ]);
911 }
912
913 stat_inc_data_blk_count(sbi, 1, gc_type);
914 }
915 }
916
917 if (++phase < 5)
918 goto next_step;
919 }
920
__get_victim(struct f2fs_sb_info * sbi,unsigned int * victim,int gc_type)921 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
922 int gc_type)
923 {
924 struct sit_info *sit_i = SIT_I(sbi);
925 int ret;
926
927 down_write(&sit_i->sentry_lock);
928 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
929 NO_CHECK_TYPE, LFS);
930 up_write(&sit_i->sentry_lock);
931 return ret;
932 }
933
do_garbage_collect(struct f2fs_sb_info * sbi,unsigned int start_segno,struct gc_inode_list * gc_list,int gc_type)934 static int do_garbage_collect(struct f2fs_sb_info *sbi,
935 unsigned int start_segno,
936 struct gc_inode_list *gc_list, int gc_type)
937 {
938 struct page *sum_page;
939 struct f2fs_summary_block *sum;
940 struct blk_plug plug;
941 unsigned int segno = start_segno;
942 unsigned int end_segno = start_segno + sbi->segs_per_sec;
943 int seg_freed = 0;
944 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
945 SUM_TYPE_DATA : SUM_TYPE_NODE;
946
947 /* readahead multi ssa blocks those have contiguous address */
948 if (sbi->segs_per_sec > 1)
949 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
950 sbi->segs_per_sec, META_SSA, true);
951
952 /* reference all summary page */
953 while (segno < end_segno) {
954 sum_page = get_sum_page(sbi, segno++);
955 unlock_page(sum_page);
956 }
957
958 blk_start_plug(&plug);
959
960 for (segno = start_segno; segno < end_segno; segno++) {
961
962 /* find segment summary of victim */
963 sum_page = find_get_page(META_MAPPING(sbi),
964 GET_SUM_BLOCK(sbi, segno));
965 f2fs_put_page(sum_page, 0);
966
967 if (get_valid_blocks(sbi, segno, false) == 0 ||
968 !PageUptodate(sum_page) ||
969 unlikely(f2fs_cp_error(sbi)))
970 goto next;
971
972 sum = page_address(sum_page);
973 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer)));
974
975 /*
976 * this is to avoid deadlock:
977 * - lock_page(sum_page) - f2fs_replace_block
978 * - check_valid_map() - down_write(sentry_lock)
979 * - down_read(sentry_lock) - change_curseg()
980 * - lock_page(sum_page)
981 */
982 if (type == SUM_TYPE_NODE)
983 gc_node_segment(sbi, sum->entries, segno, gc_type);
984 else
985 gc_data_segment(sbi, sum->entries, gc_list, segno,
986 gc_type);
987
988 stat_inc_seg_count(sbi, type, gc_type);
989
990 if (gc_type == FG_GC &&
991 get_valid_blocks(sbi, segno, false) == 0)
992 seg_freed++;
993 next:
994 f2fs_put_page(sum_page, 0);
995 }
996
997 if (gc_type == FG_GC)
998 f2fs_submit_merged_write(sbi,
999 (type == SUM_TYPE_NODE) ? NODE : DATA);
1000
1001 blk_finish_plug(&plug);
1002
1003 stat_inc_call_count(sbi->stat_info);
1004
1005 return seg_freed;
1006 }
1007
f2fs_gc(struct f2fs_sb_info * sbi,bool sync,bool background,unsigned int segno)1008 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
1009 bool background, unsigned int segno)
1010 {
1011 int gc_type = sync ? FG_GC : BG_GC;
1012 int sec_freed = 0, seg_freed = 0, total_freed = 0;
1013 int ret = 0;
1014 struct cp_control cpc;
1015 unsigned int init_segno = segno;
1016 struct gc_inode_list gc_list = {
1017 .ilist = LIST_HEAD_INIT(gc_list.ilist),
1018 .iroot = RADIX_TREE_INIT(GFP_NOFS),
1019 };
1020
1021 trace_f2fs_gc_begin(sbi->sb, sync, background,
1022 get_pages(sbi, F2FS_DIRTY_NODES),
1023 get_pages(sbi, F2FS_DIRTY_DENTS),
1024 get_pages(sbi, F2FS_DIRTY_IMETA),
1025 free_sections(sbi),
1026 free_segments(sbi),
1027 reserved_segments(sbi),
1028 prefree_segments(sbi));
1029
1030 cpc.reason = __get_cp_reason(sbi);
1031 gc_more:
1032 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) {
1033 ret = -EINVAL;
1034 goto stop;
1035 }
1036 if (unlikely(f2fs_cp_error(sbi))) {
1037 ret = -EIO;
1038 goto stop;
1039 }
1040
1041 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1042 /*
1043 * For example, if there are many prefree_segments below given
1044 * threshold, we can make them free by checkpoint. Then, we
1045 * secure free segments which doesn't need fggc any more.
1046 */
1047 if (prefree_segments(sbi)) {
1048 ret = write_checkpoint(sbi, &cpc);
1049 if (ret)
1050 goto stop;
1051 }
1052 if (has_not_enough_free_secs(sbi, 0, 0))
1053 gc_type = FG_GC;
1054 }
1055
1056 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1057 if (gc_type == BG_GC && !background) {
1058 ret = -EINVAL;
1059 goto stop;
1060 }
1061 if (!__get_victim(sbi, &segno, gc_type)) {
1062 ret = -ENODATA;
1063 goto stop;
1064 }
1065
1066 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1067 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1068 sec_freed++;
1069 total_freed += seg_freed;
1070
1071 if (gc_type == FG_GC)
1072 sbi->cur_victim_sec = NULL_SEGNO;
1073
1074 if (!sync) {
1075 if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1076 segno = NULL_SEGNO;
1077 goto gc_more;
1078 }
1079
1080 if (gc_type == FG_GC)
1081 ret = write_checkpoint(sbi, &cpc);
1082 }
1083 stop:
1084 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1085 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1086
1087 trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1088 get_pages(sbi, F2FS_DIRTY_NODES),
1089 get_pages(sbi, F2FS_DIRTY_DENTS),
1090 get_pages(sbi, F2FS_DIRTY_IMETA),
1091 free_sections(sbi),
1092 free_segments(sbi),
1093 reserved_segments(sbi),
1094 prefree_segments(sbi));
1095
1096 mutex_unlock(&sbi->gc_mutex);
1097
1098 put_gc_inode(&gc_list);
1099
1100 if (sync)
1101 ret = sec_freed ? 0 : -EAGAIN;
1102 return ret;
1103 }
1104
build_gc_manager(struct f2fs_sb_info * sbi)1105 void build_gc_manager(struct f2fs_sb_info *sbi)
1106 {
1107 u64 main_count, resv_count, ovp_count;
1108
1109 DIRTY_I(sbi)->v_ops = &default_v_ops;
1110
1111 /* threshold of # of valid blocks in a section for victims of FG_GC */
1112 main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg;
1113 resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg;
1114 ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
1115
1116 sbi->fggc_threshold = div64_u64((main_count - ovp_count) *
1117 BLKS_PER_SEC(sbi), (main_count - resv_count));
1118 sbi->gc_pin_file_threshold = DEF_GC_FAILED_PINNED_FILES;
1119
1120 /* give warm/cold data area from slower device */
1121 if (sbi->s_ndevs && sbi->segs_per_sec == 1)
1122 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1123 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1124 }
1125