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Merge tag 'linux-kselftest-4.15-rc1' of git://git.kernel.org/pub/scm/linux/kernel...
[linux/fpc-iii.git] / fs / f2fs / gc.c
blob5d5bba462f26390512a50c4359ebc99b3b3481dc
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
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 (!mutex_trylock(&sbi->gc_mutex))
80 goto next;
81
82 if (gc_th->gc_urgent) {
83 wait_ms = gc_th->urgent_sleep_time;
84 goto do_gc;
85 }
86
87 if (!is_idle(sbi)) {
88 increase_sleep_time(gc_th, &wait_ms);
89 mutex_unlock(&sbi->gc_mutex);
90 goto next;
91 }
92
93 if (has_enough_invalid_blocks(sbi))
94 decrease_sleep_time(gc_th, &wait_ms);
95 else
96 increase_sleep_time(gc_th, &wait_ms);
97 do_gc:
98 stat_inc_bggc_count(sbi);
99
100 /* if return value is not zero, no victim was selected */
101 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
102 wait_ms = gc_th->no_gc_sleep_time;
103
104 trace_f2fs_background_gc(sbi->sb, wait_ms,
105 prefree_segments(sbi), free_segments(sbi));
106
107 /* balancing f2fs's metadata periodically */
108 f2fs_balance_fs_bg(sbi);
109 next:
110 sb_end_write(sbi->sb);
111
112 } while (!kthread_should_stop());
113 return 0;
114 }
115
116 int start_gc_thread(struct f2fs_sb_info *sbi)
117 {
118 struct f2fs_gc_kthread *gc_th;
119 dev_t dev = sbi->sb->s_bdev->bd_dev;
120 int err = 0;
121
122 gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
123 if (!gc_th) {
124 err = -ENOMEM;
125 goto out;
126 }
127
128 gc_th->urgent_sleep_time = DEF_GC_THREAD_URGENT_SLEEP_TIME;
129 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
130 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
131 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
132
133 gc_th->gc_idle = 0;
134 gc_th->gc_urgent = 0;
135 gc_th->gc_wake= 0;
136
137 sbi->gc_thread = gc_th;
138 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
139 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
140 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
141 if (IS_ERR(gc_th->f2fs_gc_task)) {
142 err = PTR_ERR(gc_th->f2fs_gc_task);
143 kfree(gc_th);
144 sbi->gc_thread = NULL;
145 }
146 out:
147 return err;
148 }
149
150 void stop_gc_thread(struct f2fs_sb_info *sbi)
151 {
152 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
153 if (!gc_th)
154 return;
155 kthread_stop(gc_th->f2fs_gc_task);
156 kfree(gc_th);
157 sbi->gc_thread = NULL;
158 }
159
160 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
161 {
162 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
163
164 if (gc_th && gc_th->gc_idle) {
165 if (gc_th->gc_idle == 1)
166 gc_mode = GC_CB;
167 else if (gc_th->gc_idle == 2)
168 gc_mode = GC_GREEDY;
169 }
170 return gc_mode;
171 }
172
173 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
174 int type, struct victim_sel_policy *p)
175 {
176 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
177
178 if (p->alloc_mode == SSR) {
179 p->gc_mode = GC_GREEDY;
180 p->dirty_segmap = dirty_i->dirty_segmap[type];
181 p->max_search = dirty_i->nr_dirty[type];
182 p->ofs_unit = 1;
183 } else {
184 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
185 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
186 p->max_search = dirty_i->nr_dirty[DIRTY];
187 p->ofs_unit = sbi->segs_per_sec;
188 }
189
190 /* we need to check every dirty segments in the FG_GC case */
191 if (gc_type != FG_GC && p->max_search > sbi->max_victim_search)
192 p->max_search = sbi->max_victim_search;
193
194 /* let's select beginning hot/small space first */
195 if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
196 p->offset = 0;
197 else
198 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
199 }
200
201 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
202 struct victim_sel_policy *p)
203 {
204 /* SSR allocates in a segment unit */
205 if (p->alloc_mode == SSR)
206 return sbi->blocks_per_seg;
207 if (p->gc_mode == GC_GREEDY)
208 return 2 * sbi->blocks_per_seg * p->ofs_unit;
209 else if (p->gc_mode == GC_CB)
210 return UINT_MAX;
211 else /* No other gc_mode */
212 return 0;
213 }
214
215 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
216 {
217 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
218 unsigned int secno;
219
220 /*
221 * If the gc_type is FG_GC, we can select victim segments
222 * selected by background GC before.
223 * Those segments guarantee they have small valid blocks.
224 */
225 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
226 if (sec_usage_check(sbi, secno))
227 continue;
228
229 if (no_fggc_candidate(sbi, secno))
230 continue;
231
232 clear_bit(secno, dirty_i->victim_secmap);
233 return GET_SEG_FROM_SEC(sbi, secno);
234 }
235 return NULL_SEGNO;
236 }
237
238 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
239 {
240 struct sit_info *sit_i = SIT_I(sbi);
241 unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
242 unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
243 unsigned long long mtime = 0;
244 unsigned int vblocks;
245 unsigned char age = 0;
246 unsigned char u;
247 unsigned int i;
248
249 for (i = 0; i < sbi->segs_per_sec; i++)
250 mtime += get_seg_entry(sbi, start + i)->mtime;
251 vblocks = get_valid_blocks(sbi, segno, true);
252
253 mtime = div_u64(mtime, sbi->segs_per_sec);
254 vblocks = div_u64(vblocks, sbi->segs_per_sec);
255
256 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
257
258 /* Handle if the system time has changed by the user */
259 if (mtime < sit_i->min_mtime)
260 sit_i->min_mtime = mtime;
261 if (mtime > sit_i->max_mtime)
262 sit_i->max_mtime = mtime;
263 if (sit_i->max_mtime != sit_i->min_mtime)
264 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
265 sit_i->max_mtime - sit_i->min_mtime);
266
267 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
268 }
269
270 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
271 unsigned int segno, struct victim_sel_policy *p)
272 {
273 if (p->alloc_mode == SSR)
274 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
275
276 /* alloc_mode == LFS */
277 if (p->gc_mode == GC_GREEDY)
278 return get_valid_blocks(sbi, segno, true);
279 else
280 return get_cb_cost(sbi, segno);
281 }
282
283 static unsigned int count_bits(const unsigned long *addr,
284 unsigned int offset, unsigned int len)
285 {
286 unsigned int end = offset + len, sum = 0;
287
288 while (offset < end) {
289 if (test_bit(offset++, addr))
290 ++sum;
291 }
292 return sum;
293 }
294
295 /*
296 * This function is called from two paths.
297 * One is garbage collection and the other is SSR segment selection.
298 * When it is called during GC, it just gets a victim segment
299 * and it does not remove it from dirty seglist.
300 * When it is called from SSR segment selection, it finds a segment
301 * which has minimum valid blocks and removes it from dirty seglist.
302 */
303 static int get_victim_by_default(struct f2fs_sb_info *sbi,
304 unsigned int *result, int gc_type, int type, char alloc_mode)
305 {
306 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
307 struct sit_info *sm = SIT_I(sbi);
308 struct victim_sel_policy p;
309 unsigned int secno, last_victim;
310 unsigned int last_segment = MAIN_SEGS(sbi);
311 unsigned int nsearched = 0;
312
313 mutex_lock(&dirty_i->seglist_lock);
314
315 p.alloc_mode = alloc_mode;
316 select_policy(sbi, gc_type, type, &p);
317
318 p.min_segno = NULL_SEGNO;
319 p.min_cost = get_max_cost(sbi, &p);
320
321 if (*result != NULL_SEGNO) {
322 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) &&
323 get_valid_blocks(sbi, *result, false) &&
324 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
325 p.min_segno = *result;
326 goto out;
327 }
328
329 if (p.max_search == 0)
330 goto out;
331
332 last_victim = sm->last_victim[p.gc_mode];
333 if (p.alloc_mode == LFS && gc_type == FG_GC) {
334 p.min_segno = check_bg_victims(sbi);
335 if (p.min_segno != NULL_SEGNO)
336 goto got_it;
337 }
338
339 while (1) {
340 unsigned long cost;
341 unsigned int segno;
342
343 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
344 if (segno >= last_segment) {
345 if (sm->last_victim[p.gc_mode]) {
346 last_segment =
347 sm->last_victim[p.gc_mode];
348 sm->last_victim[p.gc_mode] = 0;
349 p.offset = 0;
350 continue;
351 }
352 break;
353 }
354
355 p.offset = segno + p.ofs_unit;
356 if (p.ofs_unit > 1) {
357 p.offset -= segno % p.ofs_unit;
358 nsearched += count_bits(p.dirty_segmap,
359 p.offset - p.ofs_unit,
360 p.ofs_unit);
361 } else {
362 nsearched++;
363 }
364
365 secno = GET_SEC_FROM_SEG(sbi, segno);
366
367 if (sec_usage_check(sbi, secno))
368 goto next;
369 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
370 goto next;
371 if (gc_type == FG_GC && p.alloc_mode == LFS &&
372 no_fggc_candidate(sbi, secno))
373 goto next;
374
375 cost = get_gc_cost(sbi, segno, &p);
376
377 if (p.min_cost > cost) {
378 p.min_segno = segno;
379 p.min_cost = cost;
380 }
381 next:
382 if (nsearched >= p.max_search) {
383 if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
384 sm->last_victim[p.gc_mode] = last_victim + 1;
385 else
386 sm->last_victim[p.gc_mode] = segno + 1;
387 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
388 break;
389 }
390 }
391 if (p.min_segno != NULL_SEGNO) {
392 got_it:
393 if (p.alloc_mode == LFS) {
394 secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
395 if (gc_type == FG_GC)
396 sbi->cur_victim_sec = secno;
397 else
398 set_bit(secno, dirty_i->victim_secmap);
399 }
400 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
401
402 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
403 sbi->cur_victim_sec,
404 prefree_segments(sbi), free_segments(sbi));
405 }
406 out:
407 mutex_unlock(&dirty_i->seglist_lock);
408
409 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
410 }
411
412 static const struct victim_selection default_v_ops = {
413 .get_victim = get_victim_by_default,
414 };
415
416 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
417 {
418 struct inode_entry *ie;
419
420 ie = radix_tree_lookup(&gc_list->iroot, ino);
421 if (ie)
422 return ie->inode;
423 return NULL;
424 }
425
426 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
427 {
428 struct inode_entry *new_ie;
429
430 if (inode == find_gc_inode(gc_list, inode->i_ino)) {
431 iput(inode);
432 return;
433 }
434 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
435 new_ie->inode = inode;
436
437 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
438 list_add_tail(&new_ie->list, &gc_list->ilist);
439 }
440
441 static void put_gc_inode(struct gc_inode_list *gc_list)
442 {
443 struct inode_entry *ie, *next_ie;
444 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
445 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
446 iput(ie->inode);
447 list_del(&ie->list);
448 kmem_cache_free(inode_entry_slab, ie);
449 }
450 }
451
452 static int check_valid_map(struct f2fs_sb_info *sbi,
453 unsigned int segno, int offset)
454 {
455 struct sit_info *sit_i = SIT_I(sbi);
456 struct seg_entry *sentry;
457 int ret;
458
459 down_read(&sit_i->sentry_lock);
460 sentry = get_seg_entry(sbi, segno);
461 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
462 up_read(&sit_i->sentry_lock);
463 return ret;
464 }
465
466 /*
467 * This function compares node address got in summary with that in NAT.
468 * On validity, copy that node with cold status, otherwise (invalid node)
469 * ignore that.
470 */
471 static void gc_node_segment(struct f2fs_sb_info *sbi,
472 struct f2fs_summary *sum, unsigned int segno, int gc_type)
473 {
474 struct f2fs_summary *entry;
475 block_t start_addr;
476 int off;
477 int phase = 0;
478
479 start_addr = START_BLOCK(sbi, segno);
480
481 next_step:
482 entry = sum;
483
484 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
485 nid_t nid = le32_to_cpu(entry->nid);
486 struct page *node_page;
487 struct node_info ni;
488
489 /* stop BG_GC if there is not enough free sections. */
490 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
491 return;
492
493 if (check_valid_map(sbi, segno, off) == 0)
494 continue;
495
496 if (phase == 0) {
497 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
498 META_NAT, true);
499 continue;
500 }
501
502 if (phase == 1) {
503 ra_node_page(sbi, nid);
504 continue;
505 }
506
507 /* phase == 2 */
508 node_page = get_node_page(sbi, nid);
509 if (IS_ERR(node_page))
510 continue;
511
512 /* block may become invalid during get_node_page */
513 if (check_valid_map(sbi, segno, off) == 0) {
514 f2fs_put_page(node_page, 1);
515 continue;
516 }
517
518 get_node_info(sbi, nid, &ni);
519 if (ni.blk_addr != start_addr + off) {
520 f2fs_put_page(node_page, 1);
521 continue;
522 }
523
524 move_node_page(node_page, gc_type);
525 stat_inc_node_blk_count(sbi, 1, gc_type);
526 }
527
528 if (++phase < 3)
529 goto next_step;
530 }
531
532 /*
533 * Calculate start block index indicating the given node offset.
534 * Be careful, caller should give this node offset only indicating direct node
535 * blocks. If any node offsets, which point the other types of node blocks such
536 * as indirect or double indirect node blocks, are given, it must be a caller's
537 * bug.
538 */
539 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
540 {
541 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
542 unsigned int bidx;
543
544 if (node_ofs == 0)
545 return 0;
546
547 if (node_ofs <= 2) {
548 bidx = node_ofs - 1;
549 } else if (node_ofs <= indirect_blks) {
550 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
551 bidx = node_ofs - 2 - dec;
552 } else {
553 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
554 bidx = node_ofs - 5 - dec;
555 }
556 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
557 }
558
559 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
560 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
561 {
562 struct page *node_page;
563 nid_t nid;
564 unsigned int ofs_in_node;
565 block_t source_blkaddr;
566
567 nid = le32_to_cpu(sum->nid);
568 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
569
570 node_page = get_node_page(sbi, nid);
571 if (IS_ERR(node_page))
572 return false;
573
574 get_node_info(sbi, nid, dni);
575
576 if (sum->version != dni->version) {
577 f2fs_msg(sbi->sb, KERN_WARNING,
578 "%s: valid data with mismatched node version.",
579 __func__);
580 set_sbi_flag(sbi, SBI_NEED_FSCK);
581 }
582
583 *nofs = ofs_of_node(node_page);
584 source_blkaddr = datablock_addr(NULL, node_page, ofs_in_node);
585 f2fs_put_page(node_page, 1);
586
587 if (source_blkaddr != blkaddr)
588 return false;
589 return true;
590 }
591
592 /*
593 * Move data block via META_MAPPING while keeping locked data page.
594 * This can be used to move blocks, aka LBAs, directly on disk.
595 */
596 static void move_data_block(struct inode *inode, block_t bidx,
597 unsigned int segno, int off)
598 {
599 struct f2fs_io_info fio = {
600 .sbi = F2FS_I_SB(inode),
601 .ino = inode->i_ino,
602 .type = DATA,
603 .temp = COLD,
604 .op = REQ_OP_READ,
605 .op_flags = 0,
606 .encrypted_page = NULL,
607 .in_list = false,
608 };
609 struct dnode_of_data dn;
610 struct f2fs_summary sum;
611 struct node_info ni;
612 struct page *page;
613 block_t newaddr;
614 int err;
615
616 /* do not read out */
617 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
618 if (!page)
619 return;
620
621 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
622 goto out;
623
624 if (f2fs_is_atomic_file(inode))
625 goto out;
626
627 set_new_dnode(&dn, inode, NULL, NULL, 0);
628 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
629 if (err)
630 goto out;
631
632 if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
633 ClearPageUptodate(page);
634 goto put_out;
635 }
636
637 /*
638 * don't cache encrypted data into meta inode until previous dirty
639 * data were writebacked to avoid racing between GC and flush.
640 */
641 f2fs_wait_on_page_writeback(page, DATA, true);
642
643 get_node_info(fio.sbi, dn.nid, &ni);
644 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
645
646 /* read page */
647 fio.page = page;
648 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
649
650 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
651 &sum, CURSEG_COLD_DATA, NULL, false);
652
653 fio.encrypted_page = f2fs_pagecache_get_page(META_MAPPING(fio.sbi),
654 newaddr, FGP_LOCK | FGP_CREAT, GFP_NOFS);
655 if (!fio.encrypted_page) {
656 err = -ENOMEM;
657 goto recover_block;
658 }
659
660 err = f2fs_submit_page_bio(&fio);
661 if (err)
662 goto put_page_out;
663
664 /* write page */
665 lock_page(fio.encrypted_page);
666
667 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
668 err = -EIO;
669 goto put_page_out;
670 }
671 if (unlikely(!PageUptodate(fio.encrypted_page))) {
672 err = -EIO;
673 goto put_page_out;
674 }
675
676 set_page_dirty(fio.encrypted_page);
677 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
678 if (clear_page_dirty_for_io(fio.encrypted_page))
679 dec_page_count(fio.sbi, F2FS_DIRTY_META);
680
681 set_page_writeback(fio.encrypted_page);
682
683 /* allocate block address */
684 f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
685
686 fio.op = REQ_OP_WRITE;
687 fio.op_flags = REQ_SYNC;
688 fio.new_blkaddr = newaddr;
689 f2fs_submit_page_write(&fio);
690
691 f2fs_update_iostat(fio.sbi, FS_GC_DATA_IO, F2FS_BLKSIZE);
692
693 f2fs_update_data_blkaddr(&dn, newaddr);
694 set_inode_flag(inode, FI_APPEND_WRITE);
695 if (page->index == 0)
696 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
697 put_page_out:
698 f2fs_put_page(fio.encrypted_page, 1);
699 recover_block:
700 if (err)
701 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
702 true, true);
703 put_out:
704 f2fs_put_dnode(&dn);
705 out:
706 f2fs_put_page(page, 1);
707 }
708
709 static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
710 unsigned int segno, int off)
711 {
712 struct page *page;
713
714 page = get_lock_data_page(inode, bidx, true);
715 if (IS_ERR(page))
716 return;
717
718 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
719 goto out;
720
721 if (f2fs_is_atomic_file(inode))
722 goto out;
723
724 if (gc_type == BG_GC) {
725 if (PageWriteback(page))
726 goto out;
727 set_page_dirty(page);
728 set_cold_data(page);
729 } else {
730 struct f2fs_io_info fio = {
731 .sbi = F2FS_I_SB(inode),
732 .ino = inode->i_ino,
733 .type = DATA,
734 .temp = COLD,
735 .op = REQ_OP_WRITE,
736 .op_flags = REQ_SYNC,
737 .old_blkaddr = NULL_ADDR,
738 .page = page,
739 .encrypted_page = NULL,
740 .need_lock = LOCK_REQ,
741 .io_type = FS_GC_DATA_IO,
742 };
743 bool is_dirty = PageDirty(page);
744 int err;
745
746 retry:
747 set_page_dirty(page);
748 f2fs_wait_on_page_writeback(page, DATA, true);
749 if (clear_page_dirty_for_io(page)) {
750 inode_dec_dirty_pages(inode);
751 remove_dirty_inode(inode);
752 }
753
754 set_cold_data(page);
755
756 err = do_write_data_page(&fio);
757 if (err == -ENOMEM && is_dirty) {
758 congestion_wait(BLK_RW_ASYNC, HZ/50);
759 goto retry;
760 }
761 }
762 out:
763 f2fs_put_page(page, 1);
764 }
765
766 /*
767 * This function tries to get parent node of victim data block, and identifies
768 * data block validity. If the block is valid, copy that with cold status and
769 * modify parent node.
770 * If the parent node is not valid or the data block address is different,
771 * the victim data block is ignored.
772 */
773 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
774 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
775 {
776 struct super_block *sb = sbi->sb;
777 struct f2fs_summary *entry;
778 block_t start_addr;
779 int off;
780 int phase = 0;
781
782 start_addr = START_BLOCK(sbi, segno);
783
784 next_step:
785 entry = sum;
786
787 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
788 struct page *data_page;
789 struct inode *inode;
790 struct node_info dni; /* dnode info for the data */
791 unsigned int ofs_in_node, nofs;
792 block_t start_bidx;
793 nid_t nid = le32_to_cpu(entry->nid);
794
795 /* stop BG_GC if there is not enough free sections. */
796 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
797 return;
798
799 if (check_valid_map(sbi, segno, off) == 0)
800 continue;
801
802 if (phase == 0) {
803 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
804 META_NAT, true);
805 continue;
806 }
807
808 if (phase == 1) {
809 ra_node_page(sbi, nid);
810 continue;
811 }
812
813 /* Get an inode by ino with checking validity */
814 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
815 continue;
816
817 if (phase == 2) {
818 ra_node_page(sbi, dni.ino);
819 continue;
820 }
821
822 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
823
824 if (phase == 3) {
825 inode = f2fs_iget(sb, dni.ino);
826 if (IS_ERR(inode) || is_bad_inode(inode))
827 continue;
828
829 /* if encrypted inode, let's go phase 3 */
830 if (f2fs_encrypted_file(inode)) {
831 add_gc_inode(gc_list, inode);
832 continue;
833 }
834
835 if (!down_write_trylock(
836 &F2FS_I(inode)->dio_rwsem[WRITE])) {
837 iput(inode);
838 continue;
839 }
840
841 start_bidx = start_bidx_of_node(nofs, inode);
842 data_page = get_read_data_page(inode,
843 start_bidx + ofs_in_node, REQ_RAHEAD,
844 true);
845 up_write(&F2FS_I(inode)->dio_rwsem[WRITE]);
846 if (IS_ERR(data_page)) {
847 iput(inode);
848 continue;
849 }
850
851 f2fs_put_page(data_page, 0);
852 add_gc_inode(gc_list, inode);
853 continue;
854 }
855
856 /* phase 4 */
857 inode = find_gc_inode(gc_list, dni.ino);
858 if (inode) {
859 struct f2fs_inode_info *fi = F2FS_I(inode);
860 bool locked = false;
861
862 if (S_ISREG(inode->i_mode)) {
863 if (!down_write_trylock(&fi->dio_rwsem[READ]))
864 continue;
865 if (!down_write_trylock(
866 &fi->dio_rwsem[WRITE])) {
867 up_write(&fi->dio_rwsem[READ]);
868 continue;
869 }
870 locked = true;
871
872 /* wait for all inflight aio data */
873 inode_dio_wait(inode);
874 }
875
876 start_bidx = start_bidx_of_node(nofs, inode)
877 + ofs_in_node;
878 if (f2fs_encrypted_file(inode))
879 move_data_block(inode, start_bidx, segno, off);
880 else
881 move_data_page(inode, start_bidx, gc_type,
882 segno, off);
883
884 if (locked) {
885 up_write(&fi->dio_rwsem[WRITE]);
886 up_write(&fi->dio_rwsem[READ]);
887 }
888
889 stat_inc_data_blk_count(sbi, 1, gc_type);
890 }
891 }
892
893 if (++phase < 5)
894 goto next_step;
895 }
896
897 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
898 int gc_type)
899 {
900 struct sit_info *sit_i = SIT_I(sbi);
901 int ret;
902
903 down_write(&sit_i->sentry_lock);
904 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
905 NO_CHECK_TYPE, LFS);
906 up_write(&sit_i->sentry_lock);
907 return ret;
908 }
909
910 static int do_garbage_collect(struct f2fs_sb_info *sbi,
911 unsigned int start_segno,
912 struct gc_inode_list *gc_list, int gc_type)
913 {
914 struct page *sum_page;
915 struct f2fs_summary_block *sum;
916 struct blk_plug plug;
917 unsigned int segno = start_segno;
918 unsigned int end_segno = start_segno + sbi->segs_per_sec;
919 int seg_freed = 0;
920 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
921 SUM_TYPE_DATA : SUM_TYPE_NODE;
922
923 /* readahead multi ssa blocks those have contiguous address */
924 if (sbi->segs_per_sec > 1)
925 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
926 sbi->segs_per_sec, META_SSA, true);
927
928 /* reference all summary page */
929 while (segno < end_segno) {
930 sum_page = get_sum_page(sbi, segno++);
931 unlock_page(sum_page);
932 }
933
934 blk_start_plug(&plug);
935
936 for (segno = start_segno; segno < end_segno; segno++) {
937
938 /* find segment summary of victim */
939 sum_page = find_get_page(META_MAPPING(sbi),
940 GET_SUM_BLOCK(sbi, segno));
941 f2fs_put_page(sum_page, 0);
942
943 if (get_valid_blocks(sbi, segno, false) == 0 ||
944 !PageUptodate(sum_page) ||
945 unlikely(f2fs_cp_error(sbi)))
946 goto next;
947
948 sum = page_address(sum_page);
949 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer)));
950
951 /*
952 * this is to avoid deadlock:
953 * - lock_page(sum_page) - f2fs_replace_block
954 * - check_valid_map() - down_write(sentry_lock)
955 * - down_read(sentry_lock) - change_curseg()
956 * - lock_page(sum_page)
957 */
958 if (type == SUM_TYPE_NODE)
959 gc_node_segment(sbi, sum->entries, segno, gc_type);
960 else
961 gc_data_segment(sbi, sum->entries, gc_list, segno,
962 gc_type);
963
964 stat_inc_seg_count(sbi, type, gc_type);
965
966 if (gc_type == FG_GC &&
967 get_valid_blocks(sbi, segno, false) == 0)
968 seg_freed++;
969 next:
970 f2fs_put_page(sum_page, 0);
971 }
972
973 if (gc_type == FG_GC)
974 f2fs_submit_merged_write(sbi,
975 (type == SUM_TYPE_NODE) ? NODE : DATA);
976
977 blk_finish_plug(&plug);
978
979 stat_inc_call_count(sbi->stat_info);
980
981 return seg_freed;
982 }
983
984 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
985 bool background, unsigned int segno)
986 {
987 int gc_type = sync ? FG_GC : BG_GC;
988 int sec_freed = 0, seg_freed = 0, total_freed = 0;
989 int ret = 0;
990 struct cp_control cpc;
991 unsigned int init_segno = segno;
992 struct gc_inode_list gc_list = {
993 .ilist = LIST_HEAD_INIT(gc_list.ilist),
994 .iroot = RADIX_TREE_INIT(GFP_NOFS),
995 };
996
997 trace_f2fs_gc_begin(sbi->sb, sync, background,
998 get_pages(sbi, F2FS_DIRTY_NODES),
999 get_pages(sbi, F2FS_DIRTY_DENTS),
1000 get_pages(sbi, F2FS_DIRTY_IMETA),
1001 free_sections(sbi),
1002 free_segments(sbi),
1003 reserved_segments(sbi),
1004 prefree_segments(sbi));
1005
1006 cpc.reason = __get_cp_reason(sbi);
1007 gc_more:
1008 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) {
1009 ret = -EINVAL;
1010 goto stop;
1011 }
1012 if (unlikely(f2fs_cp_error(sbi))) {
1013 ret = -EIO;
1014 goto stop;
1015 }
1016
1017 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
1018 /*
1019 * For example, if there are many prefree_segments below given
1020 * threshold, we can make them free by checkpoint. Then, we
1021 * secure free segments which doesn't need fggc any more.
1022 */
1023 if (prefree_segments(sbi)) {
1024 ret = write_checkpoint(sbi, &cpc);
1025 if (ret)
1026 goto stop;
1027 }
1028 if (has_not_enough_free_secs(sbi, 0, 0))
1029 gc_type = FG_GC;
1030 }
1031
1032 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1033 if (gc_type == BG_GC && !background) {
1034 ret = -EINVAL;
1035 goto stop;
1036 }
1037 if (!__get_victim(sbi, &segno, gc_type)) {
1038 ret = -ENODATA;
1039 goto stop;
1040 }
1041
1042 seg_freed = do_garbage_collect(sbi, segno, &gc_list, gc_type);
1043 if (gc_type == FG_GC && seg_freed == sbi->segs_per_sec)
1044 sec_freed++;
1045 total_freed += seg_freed;
1046
1047 if (gc_type == FG_GC)
1048 sbi->cur_victim_sec = NULL_SEGNO;
1049
1050 if (!sync) {
1051 if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1052 segno = NULL_SEGNO;
1053 goto gc_more;
1054 }
1055
1056 if (gc_type == FG_GC)
1057 ret = write_checkpoint(sbi, &cpc);
1058 }
1059 stop:
1060 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1061 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1062
1063 trace_f2fs_gc_end(sbi->sb, ret, total_freed, sec_freed,
1064 get_pages(sbi, F2FS_DIRTY_NODES),
1065 get_pages(sbi, F2FS_DIRTY_DENTS),
1066 get_pages(sbi, F2FS_DIRTY_IMETA),
1067 free_sections(sbi),
1068 free_segments(sbi),
1069 reserved_segments(sbi),
1070 prefree_segments(sbi));
1071
1072 mutex_unlock(&sbi->gc_mutex);
1073
1074 put_gc_inode(&gc_list);
1075
1076 if (sync)
1077 ret = sec_freed ? 0 : -EAGAIN;
1078 return ret;
1079 }
1080
1081 void build_gc_manager(struct f2fs_sb_info *sbi)
1082 {
1083 u64 main_count, resv_count, ovp_count;
1084
1085 DIRTY_I(sbi)->v_ops = &default_v_ops;
1086
1087 /* threshold of # of valid blocks in a section for victims of FG_GC */
1088 main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg;
1089 resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg;
1090 ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
1091
1092 sbi->fggc_threshold = div64_u64((main_count - ovp_count) *
1093 BLKS_PER_SEC(sbi), (main_count - resv_count));
1094
1095 /* give warm/cold data area from slower device */
1096 if (sbi->s_ndevs && sbi->segs_per_sec == 1)
1097 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1098 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1099 }
Linux with added FPC-III support