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strparser: initialize all callbacks
[linux/fpc-iii.git] / fs / f2fs / gc.c
blobfa3d2e2df8e70e883011afc5e46c9989e0e834ff
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 long 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 msecs_to_jiffies(wait_ms));
40
41 if (try_to_freeze())
42 continue;
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 #ifdef CONFIG_F2FS_FAULT_INJECTION
52 if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
53 f2fs_show_injection_info(FAULT_CHECKPOINT);
54 f2fs_stop_checkpoint(sbi, false);
55 }
56 #endif
57
58 /*
59 * [GC triggering condition]
60 * 0. GC is not conducted currently.
61 * 1. There are enough dirty segments.
62 * 2. IO subsystem is idle by checking the # of writeback pages.
63 * 3. IO subsystem is idle by checking the # of requests in
64 * bdev's request list.
65 *
66 * Note) We have to avoid triggering GCs frequently.
67 * Because it is possible that some segments can be
68 * invalidated soon after by user update or deletion.
69 * So, I'd like to wait some time to collect dirty segments.
70 */
71 if (!mutex_trylock(&sbi->gc_mutex))
72 continue;
73
74 if (!is_idle(sbi)) {
75 increase_sleep_time(gc_th, &wait_ms);
76 mutex_unlock(&sbi->gc_mutex);
77 continue;
78 }
79
80 if (has_enough_invalid_blocks(sbi))
81 decrease_sleep_time(gc_th, &wait_ms);
82 else
83 increase_sleep_time(gc_th, &wait_ms);
84
85 stat_inc_bggc_count(sbi);
86
87 /* if return value is not zero, no victim was selected */
88 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC), true, NULL_SEGNO))
89 wait_ms = gc_th->no_gc_sleep_time;
90
91 trace_f2fs_background_gc(sbi->sb, wait_ms,
92 prefree_segments(sbi), free_segments(sbi));
93
94 /* balancing f2fs's metadata periodically */
95 f2fs_balance_fs_bg(sbi);
96
97 } while (!kthread_should_stop());
98 return 0;
99 }
100
101 int start_gc_thread(struct f2fs_sb_info *sbi)
102 {
103 struct f2fs_gc_kthread *gc_th;
104 dev_t dev = sbi->sb->s_bdev->bd_dev;
105 int err = 0;
106
107 gc_th = f2fs_kmalloc(sbi, sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
108 if (!gc_th) {
109 err = -ENOMEM;
110 goto out;
111 }
112
113 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
114 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
115 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
116
117 gc_th->gc_idle = 0;
118
119 sbi->gc_thread = gc_th;
120 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
121 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
122 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
123 if (IS_ERR(gc_th->f2fs_gc_task)) {
124 err = PTR_ERR(gc_th->f2fs_gc_task);
125 kfree(gc_th);
126 sbi->gc_thread = NULL;
127 }
128 out:
129 return err;
130 }
131
132 void stop_gc_thread(struct f2fs_sb_info *sbi)
133 {
134 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
135 if (!gc_th)
136 return;
137 kthread_stop(gc_th->f2fs_gc_task);
138 kfree(gc_th);
139 sbi->gc_thread = NULL;
140 }
141
142 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
143 {
144 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
145
146 if (gc_th && gc_th->gc_idle) {
147 if (gc_th->gc_idle == 1)
148 gc_mode = GC_CB;
149 else if (gc_th->gc_idle == 2)
150 gc_mode = GC_GREEDY;
151 }
152 return gc_mode;
153 }
154
155 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
156 int type, struct victim_sel_policy *p)
157 {
158 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
159
160 if (p->alloc_mode == SSR) {
161 p->gc_mode = GC_GREEDY;
162 p->dirty_segmap = dirty_i->dirty_segmap[type];
163 p->max_search = dirty_i->nr_dirty[type];
164 p->ofs_unit = 1;
165 } else {
166 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
167 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
168 p->max_search = dirty_i->nr_dirty[DIRTY];
169 p->ofs_unit = sbi->segs_per_sec;
170 }
171
172 /* we need to check every dirty segments in the FG_GC case */
173 if (gc_type != FG_GC && p->max_search > sbi->max_victim_search)
174 p->max_search = sbi->max_victim_search;
175
176 /* let's select beginning hot/small space first */
177 if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
178 p->offset = 0;
179 else
180 p->offset = SIT_I(sbi)->last_victim[p->gc_mode];
181 }
182
183 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
184 struct victim_sel_policy *p)
185 {
186 /* SSR allocates in a segment unit */
187 if (p->alloc_mode == SSR)
188 return sbi->blocks_per_seg;
189 if (p->gc_mode == GC_GREEDY)
190 return 2 * sbi->blocks_per_seg * p->ofs_unit;
191 else if (p->gc_mode == GC_CB)
192 return UINT_MAX;
193 else /* No other gc_mode */
194 return 0;
195 }
196
197 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
198 {
199 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
200 unsigned int secno;
201
202 /*
203 * If the gc_type is FG_GC, we can select victim segments
204 * selected by background GC before.
205 * Those segments guarantee they have small valid blocks.
206 */
207 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
208 if (sec_usage_check(sbi, secno))
209 continue;
210
211 if (no_fggc_candidate(sbi, secno))
212 continue;
213
214 clear_bit(secno, dirty_i->victim_secmap);
215 return GET_SEG_FROM_SEC(sbi, secno);
216 }
217 return NULL_SEGNO;
218 }
219
220 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
221 {
222 struct sit_info *sit_i = SIT_I(sbi);
223 unsigned int secno = GET_SEC_FROM_SEG(sbi, segno);
224 unsigned int start = GET_SEG_FROM_SEC(sbi, secno);
225 unsigned long long mtime = 0;
226 unsigned int vblocks;
227 unsigned char age = 0;
228 unsigned char u;
229 unsigned int i;
230
231 for (i = 0; i < sbi->segs_per_sec; i++)
232 mtime += get_seg_entry(sbi, start + i)->mtime;
233 vblocks = get_valid_blocks(sbi, segno, true);
234
235 mtime = div_u64(mtime, sbi->segs_per_sec);
236 vblocks = div_u64(vblocks, sbi->segs_per_sec);
237
238 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
239
240 /* Handle if the system time has changed by the user */
241 if (mtime < sit_i->min_mtime)
242 sit_i->min_mtime = mtime;
243 if (mtime > sit_i->max_mtime)
244 sit_i->max_mtime = mtime;
245 if (sit_i->max_mtime != sit_i->min_mtime)
246 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
247 sit_i->max_mtime - sit_i->min_mtime);
248
249 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
250 }
251
252 static unsigned int get_greedy_cost(struct f2fs_sb_info *sbi,
253 unsigned int segno)
254 {
255 unsigned int valid_blocks =
256 get_valid_blocks(sbi, segno, true);
257
258 return IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
259 valid_blocks * 2 : valid_blocks;
260 }
261
262 static unsigned int get_ssr_cost(struct f2fs_sb_info *sbi,
263 unsigned int segno)
264 {
265 struct seg_entry *se = get_seg_entry(sbi, segno);
266
267 return se->ckpt_valid_blocks > se->valid_blocks ?
268 se->ckpt_valid_blocks : se->valid_blocks;
269 }
270
271 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
272 unsigned int segno, struct victim_sel_policy *p)
273 {
274 if (p->alloc_mode == SSR)
275 return get_ssr_cost(sbi, segno);
276
277 /* alloc_mode == LFS */
278 if (p->gc_mode == GC_GREEDY)
279 return get_greedy_cost(sbi, segno);
280 else
281 return get_cb_cost(sbi, segno);
282 }
283
284 static unsigned int count_bits(const unsigned long *addr,
285 unsigned int offset, unsigned int len)
286 {
287 unsigned int end = offset + len, sum = 0;
288
289 while (offset < end) {
290 if (test_bit(offset++, addr))
291 ++sum;
292 }
293 return sum;
294 }
295
296 /*
297 * This function is called from two paths.
298 * One is garbage collection and the other is SSR segment selection.
299 * When it is called during GC, it just gets a victim segment
300 * and it does not remove it from dirty seglist.
301 * When it is called from SSR segment selection, it finds a segment
302 * which has minimum valid blocks and removes it from dirty seglist.
303 */
304 static int get_victim_by_default(struct f2fs_sb_info *sbi,
305 unsigned int *result, int gc_type, int type, char alloc_mode)
306 {
307 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
308 struct sit_info *sm = SIT_I(sbi);
309 struct victim_sel_policy p;
310 unsigned int secno, last_victim;
311 unsigned int last_segment = MAIN_SEGS(sbi);
312 unsigned int nsearched = 0;
313
314 mutex_lock(&dirty_i->seglist_lock);
315
316 p.alloc_mode = alloc_mode;
317 select_policy(sbi, gc_type, type, &p);
318
319 p.min_segno = NULL_SEGNO;
320 p.min_cost = get_max_cost(sbi, &p);
321
322 if (*result != NULL_SEGNO) {
323 if (IS_DATASEG(get_seg_entry(sbi, *result)->type) &&
324 get_valid_blocks(sbi, *result, false) &&
325 !sec_usage_check(sbi, GET_SEC_FROM_SEG(sbi, *result)))
326 p.min_segno = *result;
327 goto out;
328 }
329
330 if (p.max_search == 0)
331 goto out;
332
333 last_victim = sm->last_victim[p.gc_mode];
334 if (p.alloc_mode == LFS && gc_type == FG_GC) {
335 p.min_segno = check_bg_victims(sbi);
336 if (p.min_segno != NULL_SEGNO)
337 goto got_it;
338 }
339
340 while (1) {
341 unsigned long cost;
342 unsigned int segno;
343
344 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
345 if (segno >= last_segment) {
346 if (sm->last_victim[p.gc_mode]) {
347 last_segment =
348 sm->last_victim[p.gc_mode];
349 sm->last_victim[p.gc_mode] = 0;
350 p.offset = 0;
351 continue;
352 }
353 break;
354 }
355
356 p.offset = segno + p.ofs_unit;
357 if (p.ofs_unit > 1) {
358 p.offset -= segno % p.ofs_unit;
359 nsearched += count_bits(p.dirty_segmap,
360 p.offset - p.ofs_unit,
361 p.ofs_unit);
362 } else {
363 nsearched++;
364 }
365
366 secno = GET_SEC_FROM_SEG(sbi, segno);
367
368 if (sec_usage_check(sbi, secno))
369 goto next;
370 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
371 goto next;
372 if (gc_type == FG_GC && p.alloc_mode == LFS &&
373 no_fggc_candidate(sbi, secno))
374 goto next;
375
376 cost = get_gc_cost(sbi, segno, &p);
377
378 if (p.min_cost > cost) {
379 p.min_segno = segno;
380 p.min_cost = cost;
381 }
382 next:
383 if (nsearched >= p.max_search) {
384 if (!sm->last_victim[p.gc_mode] && segno <= last_victim)
385 sm->last_victim[p.gc_mode] = last_victim + 1;
386 else
387 sm->last_victim[p.gc_mode] = segno + 1;
388 sm->last_victim[p.gc_mode] %= MAIN_SEGS(sbi);
389 break;
390 }
391 }
392 if (p.min_segno != NULL_SEGNO) {
393 got_it:
394 if (p.alloc_mode == LFS) {
395 secno = GET_SEC_FROM_SEG(sbi, p.min_segno);
396 if (gc_type == FG_GC)
397 sbi->cur_victim_sec = secno;
398 else
399 set_bit(secno, dirty_i->victim_secmap);
400 }
401 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
402
403 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
404 sbi->cur_victim_sec,
405 prefree_segments(sbi), free_segments(sbi));
406 }
407 out:
408 mutex_unlock(&dirty_i->seglist_lock);
409
410 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
411 }
412
413 static const struct victim_selection default_v_ops = {
414 .get_victim = get_victim_by_default,
415 };
416
417 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
418 {
419 struct inode_entry *ie;
420
421 ie = radix_tree_lookup(&gc_list->iroot, ino);
422 if (ie)
423 return ie->inode;
424 return NULL;
425 }
426
427 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
428 {
429 struct inode_entry *new_ie;
430
431 if (inode == find_gc_inode(gc_list, inode->i_ino)) {
432 iput(inode);
433 return;
434 }
435 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
436 new_ie->inode = inode;
437
438 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
439 list_add_tail(&new_ie->list, &gc_list->ilist);
440 }
441
442 static void put_gc_inode(struct gc_inode_list *gc_list)
443 {
444 struct inode_entry *ie, *next_ie;
445 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
446 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
447 iput(ie->inode);
448 list_del(&ie->list);
449 kmem_cache_free(inode_entry_slab, ie);
450 }
451 }
452
453 static int check_valid_map(struct f2fs_sb_info *sbi,
454 unsigned int segno, int offset)
455 {
456 struct sit_info *sit_i = SIT_I(sbi);
457 struct seg_entry *sentry;
458 int ret;
459
460 mutex_lock(&sit_i->sentry_lock);
461 sentry = get_seg_entry(sbi, segno);
462 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
463 mutex_unlock(&sit_i->sentry_lock);
464 return ret;
465 }
466
467 /*
468 * This function compares node address got in summary with that in NAT.
469 * On validity, copy that node with cold status, otherwise (invalid node)
470 * ignore that.
471 */
472 static void gc_node_segment(struct f2fs_sb_info *sbi,
473 struct f2fs_summary *sum, unsigned int segno, int gc_type)
474 {
475 struct f2fs_summary *entry;
476 block_t start_addr;
477 int off;
478 int phase = 0;
479
480 start_addr = START_BLOCK(sbi, segno);
481
482 next_step:
483 entry = sum;
484
485 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
486 nid_t nid = le32_to_cpu(entry->nid);
487 struct page *node_page;
488 struct node_info ni;
489
490 /* stop BG_GC if there is not enough free sections. */
491 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
492 return;
493
494 if (check_valid_map(sbi, segno, off) == 0)
495 continue;
496
497 if (phase == 0) {
498 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
499 META_NAT, true);
500 continue;
501 }
502
503 if (phase == 1) {
504 ra_node_page(sbi, nid);
505 continue;
506 }
507
508 /* phase == 2 */
509 node_page = get_node_page(sbi, nid);
510 if (IS_ERR(node_page))
511 continue;
512
513 /* block may become invalid during get_node_page */
514 if (check_valid_map(sbi, segno, off) == 0) {
515 f2fs_put_page(node_page, 1);
516 continue;
517 }
518
519 get_node_info(sbi, nid, &ni);
520 if (ni.blk_addr != start_addr + off) {
521 f2fs_put_page(node_page, 1);
522 continue;
523 }
524
525 move_node_page(node_page, gc_type);
526 stat_inc_node_blk_count(sbi, 1, gc_type);
527 }
528
529 if (++phase < 3)
530 goto next_step;
531 }
532
533 /*
534 * Calculate start block index indicating the given node offset.
535 * Be careful, caller should give this node offset only indicating direct node
536 * blocks. If any node offsets, which point the other types of node blocks such
537 * as indirect or double indirect node blocks, are given, it must be a caller's
538 * bug.
539 */
540 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
541 {
542 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
543 unsigned int bidx;
544
545 if (node_ofs == 0)
546 return 0;
547
548 if (node_ofs <= 2) {
549 bidx = node_ofs - 1;
550 } else if (node_ofs <= indirect_blks) {
551 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
552 bidx = node_ofs - 2 - dec;
553 } else {
554 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
555 bidx = node_ofs - 5 - dec;
556 }
557 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
558 }
559
560 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
561 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
562 {
563 struct page *node_page;
564 nid_t nid;
565 unsigned int ofs_in_node;
566 block_t source_blkaddr;
567
568 nid = le32_to_cpu(sum->nid);
569 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
570
571 node_page = get_node_page(sbi, nid);
572 if (IS_ERR(node_page))
573 return false;
574
575 get_node_info(sbi, nid, dni);
576
577 if (sum->version != dni->version) {
578 f2fs_msg(sbi->sb, KERN_WARNING,
579 "%s: valid data with mismatched node version.",
580 __func__);
581 set_sbi_flag(sbi, SBI_NEED_FSCK);
582 }
583
584 *nofs = ofs_of_node(node_page);
585 source_blkaddr = datablock_addr(node_page, ofs_in_node);
586 f2fs_put_page(node_page, 1);
587
588 if (source_blkaddr != blkaddr)
589 return false;
590 return true;
591 }
592
593 static void move_encrypted_block(struct inode *inode, block_t bidx,
594 unsigned int segno, int off)
595 {
596 struct f2fs_io_info fio = {
597 .sbi = F2FS_I_SB(inode),
598 .type = DATA,
599 .temp = COLD,
600 .op = REQ_OP_READ,
601 .op_flags = 0,
602 .encrypted_page = NULL,
603 .in_list = false,
604 };
605 struct dnode_of_data dn;
606 struct f2fs_summary sum;
607 struct node_info ni;
608 struct page *page;
609 block_t newaddr;
610 int err;
611
612 /* do not read out */
613 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
614 if (!page)
615 return;
616
617 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
618 goto out;
619
620 if (f2fs_is_atomic_file(inode))
621 goto out;
622
623 set_new_dnode(&dn, inode, NULL, NULL, 0);
624 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
625 if (err)
626 goto out;
627
628 if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
629 ClearPageUptodate(page);
630 goto put_out;
631 }
632
633 /*
634 * don't cache encrypted data into meta inode until previous dirty
635 * data were writebacked to avoid racing between GC and flush.
636 */
637 f2fs_wait_on_page_writeback(page, DATA, true);
638
639 get_node_info(fio.sbi, dn.nid, &ni);
640 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
641
642 /* read page */
643 fio.page = page;
644 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
645
646 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
647 &sum, CURSEG_COLD_DATA, NULL, false);
648
649 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr,
650 FGP_LOCK | FGP_CREAT, GFP_NOFS);
651 if (!fio.encrypted_page) {
652 err = -ENOMEM;
653 goto recover_block;
654 }
655
656 err = f2fs_submit_page_bio(&fio);
657 if (err)
658 goto put_page_out;
659
660 /* write page */
661 lock_page(fio.encrypted_page);
662
663 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
664 err = -EIO;
665 goto put_page_out;
666 }
667 if (unlikely(!PageUptodate(fio.encrypted_page))) {
668 err = -EIO;
669 goto put_page_out;
670 }
671
672 set_page_dirty(fio.encrypted_page);
673 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
674 if (clear_page_dirty_for_io(fio.encrypted_page))
675 dec_page_count(fio.sbi, F2FS_DIRTY_META);
676
677 set_page_writeback(fio.encrypted_page);
678
679 /* allocate block address */
680 f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
681
682 fio.op = REQ_OP_WRITE;
683 fio.op_flags = REQ_SYNC;
684 fio.new_blkaddr = newaddr;
685 f2fs_submit_page_write(&fio);
686
687 f2fs_update_data_blkaddr(&dn, newaddr);
688 set_inode_flag(inode, FI_APPEND_WRITE);
689 if (page->index == 0)
690 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
691 put_page_out:
692 f2fs_put_page(fio.encrypted_page, 1);
693 recover_block:
694 if (err)
695 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
696 true, true);
697 put_out:
698 f2fs_put_dnode(&dn);
699 out:
700 f2fs_put_page(page, 1);
701 }
702
703 static void move_data_page(struct inode *inode, block_t bidx, int gc_type,
704 unsigned int segno, int off)
705 {
706 struct page *page;
707
708 page = get_lock_data_page(inode, bidx, true);
709 if (IS_ERR(page))
710 return;
711
712 if (!check_valid_map(F2FS_I_SB(inode), segno, off))
713 goto out;
714
715 if (f2fs_is_atomic_file(inode))
716 goto out;
717
718 if (gc_type == BG_GC) {
719 if (PageWriteback(page))
720 goto out;
721 set_page_dirty(page);
722 set_cold_data(page);
723 } else {
724 struct f2fs_io_info fio = {
725 .sbi = F2FS_I_SB(inode),
726 .type = DATA,
727 .temp = COLD,
728 .op = REQ_OP_WRITE,
729 .op_flags = REQ_SYNC,
730 .old_blkaddr = NULL_ADDR,
731 .page = page,
732 .encrypted_page = NULL,
733 .need_lock = LOCK_REQ,
734 };
735 bool is_dirty = PageDirty(page);
736 int err;
737
738 retry:
739 set_page_dirty(page);
740 f2fs_wait_on_page_writeback(page, DATA, true);
741 if (clear_page_dirty_for_io(page)) {
742 inode_dec_dirty_pages(inode);
743 remove_dirty_inode(inode);
744 }
745
746 set_cold_data(page);
747
748 err = do_write_data_page(&fio);
749 if (err == -ENOMEM && is_dirty) {
750 congestion_wait(BLK_RW_ASYNC, HZ/50);
751 goto retry;
752 }
753 }
754 out:
755 f2fs_put_page(page, 1);
756 }
757
758 /*
759 * This function tries to get parent node of victim data block, and identifies
760 * data block validity. If the block is valid, copy that with cold status and
761 * modify parent node.
762 * If the parent node is not valid or the data block address is different,
763 * the victim data block is ignored.
764 */
765 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
766 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
767 {
768 struct super_block *sb = sbi->sb;
769 struct f2fs_summary *entry;
770 block_t start_addr;
771 int off;
772 int phase = 0;
773
774 start_addr = START_BLOCK(sbi, segno);
775
776 next_step:
777 entry = sum;
778
779 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
780 struct page *data_page;
781 struct inode *inode;
782 struct node_info dni; /* dnode info for the data */
783 unsigned int ofs_in_node, nofs;
784 block_t start_bidx;
785 nid_t nid = le32_to_cpu(entry->nid);
786
787 /* stop BG_GC if there is not enough free sections. */
788 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0))
789 return;
790
791 if (check_valid_map(sbi, segno, off) == 0)
792 continue;
793
794 if (phase == 0) {
795 ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), 1,
796 META_NAT, true);
797 continue;
798 }
799
800 if (phase == 1) {
801 ra_node_page(sbi, nid);
802 continue;
803 }
804
805 /* Get an inode by ino with checking validity */
806 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
807 continue;
808
809 if (phase == 2) {
810 ra_node_page(sbi, dni.ino);
811 continue;
812 }
813
814 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
815
816 if (phase == 3) {
817 inode = f2fs_iget(sb, dni.ino);
818 if (IS_ERR(inode) || is_bad_inode(inode))
819 continue;
820
821 /* if encrypted inode, let's go phase 3 */
822 if (f2fs_encrypted_inode(inode) &&
823 S_ISREG(inode->i_mode)) {
824 add_gc_inode(gc_list, inode);
825 continue;
826 }
827
828 start_bidx = start_bidx_of_node(nofs, inode);
829 data_page = get_read_data_page(inode,
830 start_bidx + ofs_in_node, REQ_RAHEAD,
831 true);
832 if (IS_ERR(data_page)) {
833 iput(inode);
834 continue;
835 }
836
837 f2fs_put_page(data_page, 0);
838 add_gc_inode(gc_list, inode);
839 continue;
840 }
841
842 /* phase 4 */
843 inode = find_gc_inode(gc_list, dni.ino);
844 if (inode) {
845 struct f2fs_inode_info *fi = F2FS_I(inode);
846 bool locked = false;
847
848 if (S_ISREG(inode->i_mode)) {
849 if (!down_write_trylock(&fi->dio_rwsem[READ]))
850 continue;
851 if (!down_write_trylock(
852 &fi->dio_rwsem[WRITE])) {
853 up_write(&fi->dio_rwsem[READ]);
854 continue;
855 }
856 locked = true;
857 }
858
859 start_bidx = start_bidx_of_node(nofs, inode)
860 + ofs_in_node;
861 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
862 move_encrypted_block(inode, start_bidx, segno, off);
863 else
864 move_data_page(inode, start_bidx, gc_type, segno, off);
865
866 if (locked) {
867 up_write(&fi->dio_rwsem[WRITE]);
868 up_write(&fi->dio_rwsem[READ]);
869 }
870
871 stat_inc_data_blk_count(sbi, 1, gc_type);
872 }
873 }
874
875 if (++phase < 5)
876 goto next_step;
877 }
878
879 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
880 int gc_type)
881 {
882 struct sit_info *sit_i = SIT_I(sbi);
883 int ret;
884
885 mutex_lock(&sit_i->sentry_lock);
886 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
887 NO_CHECK_TYPE, LFS);
888 mutex_unlock(&sit_i->sentry_lock);
889 return ret;
890 }
891
892 static int do_garbage_collect(struct f2fs_sb_info *sbi,
893 unsigned int start_segno,
894 struct gc_inode_list *gc_list, int gc_type)
895 {
896 struct page *sum_page;
897 struct f2fs_summary_block *sum;
898 struct blk_plug plug;
899 unsigned int segno = start_segno;
900 unsigned int end_segno = start_segno + sbi->segs_per_sec;
901 int sec_freed = 0;
902 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
903 SUM_TYPE_DATA : SUM_TYPE_NODE;
904
905 /* readahead multi ssa blocks those have contiguous address */
906 if (sbi->segs_per_sec > 1)
907 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
908 sbi->segs_per_sec, META_SSA, true);
909
910 /* reference all summary page */
911 while (segno < end_segno) {
912 sum_page = get_sum_page(sbi, segno++);
913 unlock_page(sum_page);
914 }
915
916 blk_start_plug(&plug);
917
918 for (segno = start_segno; segno < end_segno; segno++) {
919
920 /* find segment summary of victim */
921 sum_page = find_get_page(META_MAPPING(sbi),
922 GET_SUM_BLOCK(sbi, segno));
923 f2fs_put_page(sum_page, 0);
924
925 if (get_valid_blocks(sbi, segno, false) == 0 ||
926 !PageUptodate(sum_page) ||
927 unlikely(f2fs_cp_error(sbi)))
928 goto next;
929
930 sum = page_address(sum_page);
931 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer)));
932
933 /*
934 * this is to avoid deadlock:
935 * - lock_page(sum_page) - f2fs_replace_block
936 * - check_valid_map() - mutex_lock(sentry_lock)
937 * - mutex_lock(sentry_lock) - change_curseg()
938 * - lock_page(sum_page)
939 */
940 if (type == SUM_TYPE_NODE)
941 gc_node_segment(sbi, sum->entries, segno, gc_type);
942 else
943 gc_data_segment(sbi, sum->entries, gc_list, segno,
944 gc_type);
945
946 stat_inc_seg_count(sbi, type, gc_type);
947 next:
948 f2fs_put_page(sum_page, 0);
949 }
950
951 if (gc_type == FG_GC)
952 f2fs_submit_merged_write(sbi,
953 (type == SUM_TYPE_NODE) ? NODE : DATA);
954
955 blk_finish_plug(&plug);
956
957 if (gc_type == FG_GC &&
958 get_valid_blocks(sbi, start_segno, true) == 0)
959 sec_freed = 1;
960
961 stat_inc_call_count(sbi->stat_info);
962
963 return sec_freed;
964 }
965
966 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync,
967 bool background, unsigned int segno)
968 {
969 int gc_type = sync ? FG_GC : BG_GC;
970 int sec_freed = 0;
971 int ret;
972 struct cp_control cpc;
973 unsigned int init_segno = segno;
974 struct gc_inode_list gc_list = {
975 .ilist = LIST_HEAD_INIT(gc_list.ilist),
976 .iroot = RADIX_TREE_INIT(GFP_NOFS),
977 };
978
979 cpc.reason = __get_cp_reason(sbi);
980 gc_more:
981 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE))) {
982 ret = -EINVAL;
983 goto stop;
984 }
985 if (unlikely(f2fs_cp_error(sbi))) {
986 ret = -EIO;
987 goto stop;
988 }
989
990 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0, 0)) {
991 /*
992 * For example, if there are many prefree_segments below given
993 * threshold, we can make them free by checkpoint. Then, we
994 * secure free segments which doesn't need fggc any more.
995 */
996 if (prefree_segments(sbi)) {
997 ret = write_checkpoint(sbi, &cpc);
998 if (ret)
999 goto stop;
1000 }
1001 if (has_not_enough_free_secs(sbi, 0, 0))
1002 gc_type = FG_GC;
1003 }
1004
1005 ret = -EINVAL;
1006 /* f2fs_balance_fs doesn't need to do BG_GC in critical path. */
1007 if (gc_type == BG_GC && !background)
1008 goto stop;
1009 if (!__get_victim(sbi, &segno, gc_type))
1010 goto stop;
1011 ret = 0;
1012
1013 if (do_garbage_collect(sbi, segno, &gc_list, gc_type) &&
1014 gc_type == FG_GC)
1015 sec_freed++;
1016
1017 if (gc_type == FG_GC)
1018 sbi->cur_victim_sec = NULL_SEGNO;
1019
1020 if (!sync) {
1021 if (has_not_enough_free_secs(sbi, sec_freed, 0)) {
1022 segno = NULL_SEGNO;
1023 goto gc_more;
1024 }
1025
1026 if (gc_type == FG_GC)
1027 ret = write_checkpoint(sbi, &cpc);
1028 }
1029 stop:
1030 SIT_I(sbi)->last_victim[ALLOC_NEXT] = 0;
1031 SIT_I(sbi)->last_victim[FLUSH_DEVICE] = init_segno;
1032 mutex_unlock(&sbi->gc_mutex);
1033
1034 put_gc_inode(&gc_list);
1035
1036 if (sync)
1037 ret = sec_freed ? 0 : -EAGAIN;
1038 return ret;
1039 }
1040
1041 void build_gc_manager(struct f2fs_sb_info *sbi)
1042 {
1043 u64 main_count, resv_count, ovp_count;
1044
1045 DIRTY_I(sbi)->v_ops = &default_v_ops;
1046
1047 /* threshold of # of valid blocks in a section for victims of FG_GC */
1048 main_count = SM_I(sbi)->main_segments << sbi->log_blocks_per_seg;
1049 resv_count = SM_I(sbi)->reserved_segments << sbi->log_blocks_per_seg;
1050 ovp_count = SM_I(sbi)->ovp_segments << sbi->log_blocks_per_seg;
1051
1052 sbi->fggc_threshold = div64_u64((main_count - ovp_count) *
1053 BLKS_PER_SEC(sbi), (main_count - resv_count));
1054
1055 /* give warm/cold data area from slower device */
1056 if (sbi->s_ndevs && sbi->segs_per_sec == 1)
1057 SIT_I(sbi)->last_victim[ALLOC_NEXT] =
1058 GET_SEGNO(sbi, FDEV(0).end_blk) + 1;
1059 }
Linux with added FPC-III support