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-rw-r--r--fs/f2fs/gc.c742
-rw-r--r--fs/f2fs/gc.h117
2 files changed, 859 insertions, 0 deletions
diff --git a/fs/f2fs/gc.c b/fs/f2fs/gc.c
new file mode 100644
index 000000000000..46774ce3ae03
--- /dev/null
+++ b/fs/f2fs/gc.c
@@ -0,0 +1,742 @@
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/proc_fs.h>
15#include <linux/init.h>
16#include <linux/f2fs_fs.h>
17#include <linux/kthread.h>
18#include <linux/delay.h>
19#include <linux/freezer.h>
20#include <linux/blkdev.h>
21
22#include "f2fs.h"
23#include "node.h"
24#include "segment.h"
25#include "gc.h"
26
27static struct kmem_cache *winode_slab;
28
29static int gc_thread_func(void *data)
30{
31 struct f2fs_sb_info *sbi = data;
32 wait_queue_head_t *wq = &sbi->gc_thread->gc_wait_queue_head;
33 long wait_ms;
34
35 wait_ms = GC_THREAD_MIN_SLEEP_TIME;
36
37 do {
38 if (try_to_freeze())
39 continue;
40 else
41 wait_event_interruptible_timeout(*wq,
42 kthread_should_stop(),
43 msecs_to_jiffies(wait_ms));
44 if (kthread_should_stop())
45 break;
46
47 f2fs_balance_fs(sbi);
48
49 if (!test_opt(sbi, BG_GC))
50 continue;
51
52 /*
53 * [GC triggering condition]
54 * 0. GC is not conducted currently.
55 * 1. There are enough dirty segments.
56 * 2. IO subsystem is idle by checking the # of writeback pages.
57 * 3. IO subsystem is idle by checking the # of requests in
58 * bdev's request list.
59 *
60 * Note) We have to avoid triggering GCs too much frequently.
61 * Because it is possible that some segments can be
62 * invalidated soon after by user update or deletion.
63 * So, I'd like to wait some time to collect dirty segments.
64 */
65 if (!mutex_trylock(&sbi->gc_mutex))
66 continue;
67
68 if (!is_idle(sbi)) {
69 wait_ms = increase_sleep_time(wait_ms);
70 mutex_unlock(&sbi->gc_mutex);
71 continue;
72 }
73
74 if (has_enough_invalid_blocks(sbi))
75 wait_ms = decrease_sleep_time(wait_ms);
76 else
77 wait_ms = increase_sleep_time(wait_ms);
78
79 sbi->bg_gc++;
80
81 if (f2fs_gc(sbi, 1) == GC_NONE)
82 wait_ms = GC_THREAD_NOGC_SLEEP_TIME;
83 else if (wait_ms == GC_THREAD_NOGC_SLEEP_TIME)
84 wait_ms = GC_THREAD_MAX_SLEEP_TIME;
85
86 } while (!kthread_should_stop());
87 return 0;
88}
89
90int start_gc_thread(struct f2fs_sb_info *sbi)
91{
92 struct f2fs_gc_kthread *gc_th = NULL;
93
94 gc_th = kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
95 if (!gc_th)
96 return -ENOMEM;
97
98 sbi->gc_thread = gc_th;
99 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
100 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
101 GC_THREAD_NAME);
102 if (IS_ERR(gc_th->f2fs_gc_task)) {
103 kfree(gc_th);
104 return -ENOMEM;
105 }
106 return 0;
107}
108
109void stop_gc_thread(struct f2fs_sb_info *sbi)
110{
111 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
112 if (!gc_th)
113 return;
114 kthread_stop(gc_th->f2fs_gc_task);
115 kfree(gc_th);
116 sbi->gc_thread = NULL;
117}
118
119static int select_gc_type(int gc_type)
120{
121 return (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
122}
123
124static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
125 int type, struct victim_sel_policy *p)
126{
127 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
128
129 if (p->alloc_mode) {
130 p->gc_mode = GC_GREEDY;
131 p->dirty_segmap = dirty_i->dirty_segmap[type];
132 p->ofs_unit = 1;
133 } else {
134 p->gc_mode = select_gc_type(gc_type);
135 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
136 p->ofs_unit = sbi->segs_per_sec;
137 }
138 p->offset = sbi->last_victim[p->gc_mode];
139}
140
141static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
142 struct victim_sel_policy *p)
143{
144 if (p->gc_mode == GC_GREEDY)
145 return (1 << sbi->log_blocks_per_seg) * p->ofs_unit;
146 else if (p->gc_mode == GC_CB)
147 return UINT_MAX;
148 else /* No other gc_mode */
149 return 0;
150}
151
152static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
153{
154 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
155 unsigned int segno;
156
157 /*
158 * If the gc_type is FG_GC, we can select victim segments
159 * selected by background GC before.
160 * Those segments guarantee they have small valid blocks.
161 */
162 segno = find_next_bit(dirty_i->victim_segmap[BG_GC],
163 TOTAL_SEGS(sbi), 0);
164 if (segno < TOTAL_SEGS(sbi)) {
165 clear_bit(segno, dirty_i->victim_segmap[BG_GC]);
166 return segno;
167 }
168 return NULL_SEGNO;
169}
170
171static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
172{
173 struct sit_info *sit_i = SIT_I(sbi);
174 unsigned int secno = GET_SECNO(sbi, segno);
175 unsigned int start = secno * sbi->segs_per_sec;
176 unsigned long long mtime = 0;
177 unsigned int vblocks;
178 unsigned char age = 0;
179 unsigned char u;
180 unsigned int i;
181
182 for (i = 0; i < sbi->segs_per_sec; i++)
183 mtime += get_seg_entry(sbi, start + i)->mtime;
184 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
185
186 mtime = div_u64(mtime, sbi->segs_per_sec);
187 vblocks = div_u64(vblocks, sbi->segs_per_sec);
188
189 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
190
191 /* Handle if the system time is changed by user */
192 if (mtime < sit_i->min_mtime)
193 sit_i->min_mtime = mtime;
194 if (mtime > sit_i->max_mtime)
195 sit_i->max_mtime = mtime;
196 if (sit_i->max_mtime != sit_i->min_mtime)
197 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
198 sit_i->max_mtime - sit_i->min_mtime);
199
200 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
201}
202
203static unsigned int get_gc_cost(struct f2fs_sb_info *sbi, unsigned int segno,
204 struct victim_sel_policy *p)
205{
206 if (p->alloc_mode == SSR)
207 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
208
209 /* alloc_mode == LFS */
210 if (p->gc_mode == GC_GREEDY)
211 return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
212 else
213 return get_cb_cost(sbi, segno);
214}
215
216/**
217 * This function is called from two pathes.
218 * One is garbage collection and the other is SSR segment selection.
219 * When it is called during GC, it just gets a victim segment
220 * and it does not remove it from dirty seglist.
221 * When it is called from SSR segment selection, it finds a segment
222 * which has minimum valid blocks and removes it from dirty seglist.
223 */
224static int get_victim_by_default(struct f2fs_sb_info *sbi,
225 unsigned int *result, int gc_type, int type, char alloc_mode)
226{
227 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
228 struct victim_sel_policy p;
229 unsigned int segno;
230 int nsearched = 0;
231
232 p.alloc_mode = alloc_mode;
233 select_policy(sbi, gc_type, type, &p);
234
235 p.min_segno = NULL_SEGNO;
236 p.min_cost = get_max_cost(sbi, &p);
237
238 mutex_lock(&dirty_i->seglist_lock);
239
240 if (p.alloc_mode == LFS && gc_type == FG_GC) {
241 p.min_segno = check_bg_victims(sbi);
242 if (p.min_segno != NULL_SEGNO)
243 goto got_it;
244 }
245
246 while (1) {
247 unsigned long cost;
248
249 segno = find_next_bit(p.dirty_segmap,
250 TOTAL_SEGS(sbi), p.offset);
251 if (segno >= TOTAL_SEGS(sbi)) {
252 if (sbi->last_victim[p.gc_mode]) {
253 sbi->last_victim[p.gc_mode] = 0;
254 p.offset = 0;
255 continue;
256 }
257 break;
258 }
259 p.offset = ((segno / p.ofs_unit) * p.ofs_unit) + p.ofs_unit;
260
261 if (test_bit(segno, dirty_i->victim_segmap[FG_GC]))
262 continue;
263 if (gc_type == BG_GC &&
264 test_bit(segno, dirty_i->victim_segmap[BG_GC]))
265 continue;
266 if (IS_CURSEC(sbi, GET_SECNO(sbi, segno)))
267 continue;
268
269 cost = get_gc_cost(sbi, segno, &p);
270
271 if (p.min_cost > cost) {
272 p.min_segno = segno;
273 p.min_cost = cost;
274 }
275
276 if (cost == get_max_cost(sbi, &p))
277 continue;
278
279 if (nsearched++ >= MAX_VICTIM_SEARCH) {
280 sbi->last_victim[p.gc_mode] = segno;
281 break;
282 }
283 }
284got_it:
285 if (p.min_segno != NULL_SEGNO) {
286 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
287 if (p.alloc_mode == LFS) {
288 int i;
289 for (i = 0; i < p.ofs_unit; i++)
290 set_bit(*result + i,
291 dirty_i->victim_segmap[gc_type]);
292 }
293 }
294 mutex_unlock(&dirty_i->seglist_lock);
295
296 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
297}
298
299static const struct victim_selection default_v_ops = {
300 .get_victim = get_victim_by_default,
301};
302
303static struct inode *find_gc_inode(nid_t ino, struct list_head *ilist)
304{
305 struct list_head *this;
306 struct inode_entry *ie;
307
308 list_for_each(this, ilist) {
309 ie = list_entry(this, struct inode_entry, list);
310 if (ie->inode->i_ino == ino)
311 return ie->inode;
312 }
313 return NULL;
314}
315
316static void add_gc_inode(struct inode *inode, struct list_head *ilist)
317{
318 struct list_head *this;
319 struct inode_entry *new_ie, *ie;
320
321 list_for_each(this, ilist) {
322 ie = list_entry(this, struct inode_entry, list);
323 if (ie->inode == inode) {
324 iput(inode);
325 return;
326 }
327 }
328repeat:
329 new_ie = kmem_cache_alloc(winode_slab, GFP_NOFS);
330 if (!new_ie) {
331 cond_resched();
332 goto repeat;
333 }
334 new_ie->inode = inode;
335 list_add_tail(&new_ie->list, ilist);
336}
337
338static void put_gc_inode(struct list_head *ilist)
339{
340 struct inode_entry *ie, *next_ie;
341 list_for_each_entry_safe(ie, next_ie, ilist, list) {
342 iput(ie->inode);
343 list_del(&ie->list);
344 kmem_cache_free(winode_slab, ie);
345 }
346}
347
348static int check_valid_map(struct f2fs_sb_info *sbi,
349 unsigned int segno, int offset)
350{
351 struct sit_info *sit_i = SIT_I(sbi);
352 struct seg_entry *sentry;
353 int ret;
354
355 mutex_lock(&sit_i->sentry_lock);
356 sentry = get_seg_entry(sbi, segno);
357 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
358 mutex_unlock(&sit_i->sentry_lock);
359 return ret ? GC_OK : GC_NEXT;
360}
361
362/**
363 * This function compares node address got in summary with that in NAT.
364 * On validity, copy that node with cold status, otherwise (invalid node)
365 * ignore that.
366 */
367static int gc_node_segment(struct f2fs_sb_info *sbi,
368 struct f2fs_summary *sum, unsigned int segno, int gc_type)
369{
370 bool initial = true;
371 struct f2fs_summary *entry;
372 int off;
373
374next_step:
375 entry = sum;
376 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
377 nid_t nid = le32_to_cpu(entry->nid);
378 struct page *node_page;
379 int err;
380
381 /*
382 * It makes sure that free segments are able to write
383 * all the dirty node pages before CP after this CP.
384 * So let's check the space of dirty node pages.
385 */
386 if (should_do_checkpoint(sbi)) {
387 mutex_lock(&sbi->cp_mutex);
388 block_operations(sbi);
389 return GC_BLOCKED;
390 }
391
392 err = check_valid_map(sbi, segno, off);
393 if (err == GC_ERROR)
394 return err;
395 else if (err == GC_NEXT)
396 continue;
397
398 if (initial) {
399 ra_node_page(sbi, nid);
400 continue;
401 }
402 node_page = get_node_page(sbi, nid);
403 if (IS_ERR(node_page))
404 continue;
405
406 /* set page dirty and write it */
407 if (!PageWriteback(node_page))
408 set_page_dirty(node_page);
409 f2fs_put_page(node_page, 1);
410 stat_inc_node_blk_count(sbi, 1);
411 }
412 if (initial) {
413 initial = false;
414 goto next_step;
415 }
416
417 if (gc_type == FG_GC) {
418 struct writeback_control wbc = {
419 .sync_mode = WB_SYNC_ALL,
420 .nr_to_write = LONG_MAX,
421 .for_reclaim = 0,
422 };
423 sync_node_pages(sbi, 0, &wbc);
424 }
425 return GC_DONE;
426}
427
428/**
429 * Calculate start block index that this node page contains
430 */
431block_t start_bidx_of_node(unsigned int node_ofs)
432{
433 block_t start_bidx;
434 unsigned int bidx, indirect_blks;
435 int dec;
436
437 indirect_blks = 2 * NIDS_PER_BLOCK + 4;
438
439 start_bidx = 1;
440 if (node_ofs == 0) {
441 start_bidx = 0;
442 } else if (node_ofs <= 2) {
443 bidx = node_ofs - 1;
444 } else if (node_ofs <= indirect_blks) {
445 dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
446 bidx = node_ofs - 2 - dec;
447 } else {
448 dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
449 bidx = node_ofs - 5 - dec;
450 }
451
452 if (start_bidx)
453 start_bidx = bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE;
454 return start_bidx;
455}
456
457static int check_dnode(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
458 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
459{
460 struct page *node_page;
461 nid_t nid;
462 unsigned int ofs_in_node;
463 block_t source_blkaddr;
464
465 nid = le32_to_cpu(sum->nid);
466 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
467
468 node_page = get_node_page(sbi, nid);
469 if (IS_ERR(node_page))
470 return GC_NEXT;
471
472 get_node_info(sbi, nid, dni);
473
474 if (sum->version != dni->version) {
475 f2fs_put_page(node_page, 1);
476 return GC_NEXT;
477 }
478
479 *nofs = ofs_of_node(node_page);
480 source_blkaddr = datablock_addr(node_page, ofs_in_node);
481 f2fs_put_page(node_page, 1);
482
483 if (source_blkaddr != blkaddr)
484 return GC_NEXT;
485 return GC_OK;
486}
487
488static void move_data_page(struct inode *inode, struct page *page, int gc_type)
489{
490 if (page->mapping != inode->i_mapping)
491 goto out;
492
493 if (inode != page->mapping->host)
494 goto out;
495
496 if (PageWriteback(page))
497 goto out;
498
499 if (gc_type == BG_GC) {
500 set_page_dirty(page);
501 set_cold_data(page);
502 } else {
503 struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
504 mutex_lock_op(sbi, DATA_WRITE);
505 if (clear_page_dirty_for_io(page) &&
506 S_ISDIR(inode->i_mode)) {
507 dec_page_count(sbi, F2FS_DIRTY_DENTS);
508 inode_dec_dirty_dents(inode);
509 }
510 set_cold_data(page);
511 do_write_data_page(page);
512 mutex_unlock_op(sbi, DATA_WRITE);
513 clear_cold_data(page);
514 }
515out:
516 f2fs_put_page(page, 1);
517}
518
519/**
520 * This function tries to get parent node of victim data block, and identifies
521 * data block validity. If the block is valid, copy that with cold status and
522 * modify parent node.
523 * If the parent node is not valid or the data block address is different,
524 * the victim data block is ignored.
525 */
526static int gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
527 struct list_head *ilist, unsigned int segno, int gc_type)
528{
529 struct super_block *sb = sbi->sb;
530 struct f2fs_summary *entry;
531 block_t start_addr;
532 int err, off;
533 int phase = 0;
534
535 start_addr = START_BLOCK(sbi, segno);
536
537next_step:
538 entry = sum;
539 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
540 struct page *data_page;
541 struct inode *inode;
542 struct node_info dni; /* dnode info for the data */
543 unsigned int ofs_in_node, nofs;
544 block_t start_bidx;
545
546 /*
547 * It makes sure that free segments are able to write
548 * all the dirty node pages before CP after this CP.
549 * So let's check the space of dirty node pages.
550 */
551 if (should_do_checkpoint(sbi)) {
552 mutex_lock(&sbi->cp_mutex);
553 block_operations(sbi);
554 err = GC_BLOCKED;
555 goto stop;
556 }
557
558 err = check_valid_map(sbi, segno, off);
559 if (err == GC_ERROR)
560 goto stop;
561 else if (err == GC_NEXT)
562 continue;
563
564 if (phase == 0) {
565 ra_node_page(sbi, le32_to_cpu(entry->nid));
566 continue;
567 }
568
569 /* Get an inode by ino with checking validity */
570 err = check_dnode(sbi, entry, &dni, start_addr + off, &nofs);
571 if (err == GC_ERROR)
572 goto stop;
573 else if (err == GC_NEXT)
574 continue;
575
576 if (phase == 1) {
577 ra_node_page(sbi, dni.ino);
578 continue;
579 }
580
581 start_bidx = start_bidx_of_node(nofs);
582 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
583
584 if (phase == 2) {
585 inode = f2fs_iget_nowait(sb, dni.ino);
586 if (IS_ERR(inode))
587 continue;
588
589 data_page = find_data_page(inode,
590 start_bidx + ofs_in_node);
591 if (IS_ERR(data_page))
592 goto next_iput;
593
594 f2fs_put_page(data_page, 0);
595 add_gc_inode(inode, ilist);
596 } else {
597 inode = find_gc_inode(dni.ino, ilist);
598 if (inode) {
599 data_page = get_lock_data_page(inode,
600 start_bidx + ofs_in_node);
601 if (IS_ERR(data_page))
602 continue;
603 move_data_page(inode, data_page, gc_type);
604 stat_inc_data_blk_count(sbi, 1);
605 }
606 }
607 continue;
608next_iput:
609 iput(inode);
610 }
611 if (++phase < 4)
612 goto next_step;
613 err = GC_DONE;
614stop:
615 if (gc_type == FG_GC)
616 f2fs_submit_bio(sbi, DATA, true);
617 return err;
618}
619
620static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
621 int gc_type, int type)
622{
623 struct sit_info *sit_i = SIT_I(sbi);
624 int ret;
625 mutex_lock(&sit_i->sentry_lock);
626 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type, type, LFS);
627 mutex_unlock(&sit_i->sentry_lock);
628 return ret;
629}
630
631static int do_garbage_collect(struct f2fs_sb_info *sbi, unsigned int segno,
632 struct list_head *ilist, int gc_type)
633{
634 struct page *sum_page;
635 struct f2fs_summary_block *sum;
636 int ret = GC_DONE;
637
638 /* read segment summary of victim */
639 sum_page = get_sum_page(sbi, segno);
640 if (IS_ERR(sum_page))
641 return GC_ERROR;
642
643 /*
644 * CP needs to lock sum_page. In this time, we don't need
645 * to lock this page, because this summary page is not gone anywhere.
646 * Also, this page is not gonna be updated before GC is done.
647 */
648 unlock_page(sum_page);
649 sum = page_address(sum_page);
650
651 switch (GET_SUM_TYPE((&sum->footer))) {
652 case SUM_TYPE_NODE:
653 ret = gc_node_segment(sbi, sum->entries, segno, gc_type);
654 break;
655 case SUM_TYPE_DATA:
656 ret = gc_data_segment(sbi, sum->entries, ilist, segno, gc_type);
657 break;
658 }
659 stat_inc_seg_count(sbi, GET_SUM_TYPE((&sum->footer)));
660 stat_inc_call_count(sbi->stat_info);
661
662 f2fs_put_page(sum_page, 0);
663 return ret;
664}
665
666int f2fs_gc(struct f2fs_sb_info *sbi, int nGC)
667{
668 unsigned int segno;
669 int old_free_secs, cur_free_secs;
670 int gc_status, nfree;
671 struct list_head ilist;
672 int gc_type = BG_GC;
673
674 INIT_LIST_HEAD(&ilist);
675gc_more:
676 nfree = 0;
677 gc_status = GC_NONE;
678
679 if (has_not_enough_free_secs(sbi))
680 old_free_secs = reserved_sections(sbi);
681 else
682 old_free_secs = free_sections(sbi);
683
684 while (sbi->sb->s_flags & MS_ACTIVE) {
685 int i;
686 if (has_not_enough_free_secs(sbi))
687 gc_type = FG_GC;
688
689 cur_free_secs = free_sections(sbi) + nfree;
690
691 /* We got free space successfully. */
692 if (nGC < cur_free_secs - old_free_secs)
693 break;
694
695 if (!__get_victim(sbi, &segno, gc_type, NO_CHECK_TYPE))
696 break;
697
698 for (i = 0; i < sbi->segs_per_sec; i++) {
699 /*
700 * do_garbage_collect will give us three gc_status:
701 * GC_ERROR, GC_DONE, and GC_BLOCKED.
702 * If GC is finished uncleanly, we have to return
703 * the victim to dirty segment list.
704 */
705 gc_status = do_garbage_collect(sbi, segno + i,
706 &ilist, gc_type);
707 if (gc_status != GC_DONE)
708 goto stop;
709 nfree++;
710 }
711 }
712stop:
713 if (has_not_enough_free_secs(sbi) || gc_status == GC_BLOCKED) {
714 write_checkpoint(sbi, (gc_status == GC_BLOCKED), false);
715 if (nfree)
716 goto gc_more;
717 }
718 mutex_unlock(&sbi->gc_mutex);
719
720 put_gc_inode(&ilist);
721 BUG_ON(!list_empty(&ilist));
722 return gc_status;
723}
724
725void build_gc_manager(struct f2fs_sb_info *sbi)
726{
727 DIRTY_I(sbi)->v_ops = &default_v_ops;
728}
729
730int create_gc_caches(void)
731{
732 winode_slab = f2fs_kmem_cache_create("f2fs_gc_inodes",
733 sizeof(struct inode_entry), NULL);
734 if (!winode_slab)
735 return -ENOMEM;
736 return 0;
737}
738
739void destroy_gc_caches(void)
740{
741 kmem_cache_destroy(winode_slab);
742}
diff --git a/fs/f2fs/gc.h b/fs/f2fs/gc.h
new file mode 100644
index 000000000000..cf42a554ca0a
--- /dev/null
+++ b/fs/f2fs/gc.h
@@ -0,0 +1,117 @@
1/**
2 * fs/f2fs/gc.h
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#define GC_THREAD_NAME "f2fs_gc_task"
12#define GC_THREAD_MIN_WB_PAGES 1 /*
13 * a threshold to determine
14 * whether IO subsystem is idle
15 * or not
16 */
17#define GC_THREAD_MIN_SLEEP_TIME 10000 /* milliseconds */
18#define GC_THREAD_MAX_SLEEP_TIME 30000
19#define GC_THREAD_NOGC_SLEEP_TIME 10000
20#define LIMIT_INVALID_BLOCK 40 /* percentage over total user space */
21#define LIMIT_FREE_BLOCK 40 /* percentage over invalid + free space */
22
23/* Search max. number of dirty segments to select a victim segment */
24#define MAX_VICTIM_SEARCH 20
25
26enum {
27 GC_NONE = 0,
28 GC_ERROR,
29 GC_OK,
30 GC_NEXT,
31 GC_BLOCKED,
32 GC_DONE,
33};
34
35struct f2fs_gc_kthread {
36 struct task_struct *f2fs_gc_task;
37 wait_queue_head_t gc_wait_queue_head;
38};
39
40struct inode_entry {
41 struct list_head list;
42 struct inode *inode;
43};
44
45/**
46 * inline functions
47 */
48static inline block_t free_user_blocks(struct f2fs_sb_info *sbi)
49{
50 if (free_segments(sbi) < overprovision_segments(sbi))
51 return 0;
52 else
53 return (free_segments(sbi) - overprovision_segments(sbi))
54 << sbi->log_blocks_per_seg;
55}
56
57static inline block_t limit_invalid_user_blocks(struct f2fs_sb_info *sbi)
58{
59 return (long)(sbi->user_block_count * LIMIT_INVALID_BLOCK) / 100;
60}
61
62static inline block_t limit_free_user_blocks(struct f2fs_sb_info *sbi)
63{
64 block_t reclaimable_user_blocks = sbi->user_block_count -
65 written_block_count(sbi);
66 return (long)(reclaimable_user_blocks * LIMIT_FREE_BLOCK) / 100;
67}
68
69static inline long increase_sleep_time(long wait)
70{
71 wait += GC_THREAD_MIN_SLEEP_TIME;
72 if (wait > GC_THREAD_MAX_SLEEP_TIME)
73 wait = GC_THREAD_MAX_SLEEP_TIME;
74 return wait;
75}
76
77static inline long decrease_sleep_time(long wait)
78{
79 wait -= GC_THREAD_MIN_SLEEP_TIME;
80 if (wait <= GC_THREAD_MIN_SLEEP_TIME)
81 wait = GC_THREAD_MIN_SLEEP_TIME;
82 return wait;
83}
84
85static inline bool has_enough_invalid_blocks(struct f2fs_sb_info *sbi)
86{
87 block_t invalid_user_blocks = sbi->user_block_count -
88 written_block_count(sbi);
89 /*
90 * Background GC is triggered with the following condition.
91 * 1. There are a number of invalid blocks.
92 * 2. There is not enough free space.
93 */
94 if (invalid_user_blocks > limit_invalid_user_blocks(sbi) &&
95 free_user_blocks(sbi) < limit_free_user_blocks(sbi))
96 return true;
97 return false;
98}
99
100static inline int is_idle(struct f2fs_sb_info *sbi)
101{
102 struct block_device *bdev = sbi->sb->s_bdev;
103 struct request_queue *q = bdev_get_queue(bdev);
104 struct request_list *rl = &q->root_rl;
105 return !(rl->count[BLK_RW_SYNC]) && !(rl->count[BLK_RW_ASYNC]);
106}
107
108static inline bool should_do_checkpoint(struct f2fs_sb_info *sbi)
109{
110 unsigned int pages_per_sec = sbi->segs_per_sec *
111 (1 << sbi->log_blocks_per_seg);
112 int node_secs = ((get_pages(sbi, F2FS_DIRTY_NODES) + pages_per_sec - 1)
113 >> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
114 int dent_secs = ((get_pages(sbi, F2FS_DIRTY_DENTS) + pages_per_sec - 1)
115 >> sbi->log_blocks_per_seg) / sbi->segs_per_sec;
116 return free_sections(sbi) <= (node_secs + 2 * dent_secs + 2);
117}
generated by cgit v1.2.2 (git 2.25.0) at 2025-03-11 20:27:05 -0400