f2fs: enable inline_dentry by default and add noinline_dentry option
[deliverable/linux.git] / fs / f2fs / gc.c
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 do {
36 if (try_to_freeze())
37 continue;
38 else
39 wait_event_interruptible_timeout(*wq,
40 kthread_should_stop(),
41 msecs_to_jiffies(wait_ms));
42 if (kthread_should_stop())
43 break;
44
45 if (sbi->sb->s_writers.frozen >= SB_FREEZE_WRITE) {
46 increase_sleep_time(gc_th, &wait_ms);
47 continue;
48 }
49
50 /*
51 * [GC triggering condition]
52 * 0. GC is not conducted currently.
53 * 1. There are enough dirty segments.
54 * 2. IO subsystem is idle by checking the # of writeback pages.
55 * 3. IO subsystem is idle by checking the # of requests in
56 * bdev's request list.
57 *
58 * Note) We have to avoid triggering GCs frequently.
59 * Because it is possible that some segments can be
60 * invalidated soon after by user update or deletion.
61 * So, I'd like to wait some time to collect dirty segments.
62 */
63 if (!mutex_trylock(&sbi->gc_mutex))
64 continue;
65
66 if (!is_idle(sbi)) {
67 increase_sleep_time(gc_th, &wait_ms);
68 mutex_unlock(&sbi->gc_mutex);
69 continue;
70 }
71
72 if (has_enough_invalid_blocks(sbi))
73 decrease_sleep_time(gc_th, &wait_ms);
74 else
75 increase_sleep_time(gc_th, &wait_ms);
76
77 stat_inc_bggc_count(sbi);
78
79 /* if return value is not zero, no victim was selected */
80 if (f2fs_gc(sbi, test_opt(sbi, FORCE_FG_GC)))
81 wait_ms = gc_th->no_gc_sleep_time;
82
83 trace_f2fs_background_gc(sbi->sb, wait_ms,
84 prefree_segments(sbi), free_segments(sbi));
85
86 /* balancing f2fs's metadata periodically */
87 f2fs_balance_fs_bg(sbi);
88
89 } while (!kthread_should_stop());
90 return 0;
91 }
92
93 int start_gc_thread(struct f2fs_sb_info *sbi)
94 {
95 struct f2fs_gc_kthread *gc_th;
96 dev_t dev = sbi->sb->s_bdev->bd_dev;
97 int err = 0;
98
99 gc_th = f2fs_kmalloc(sizeof(struct f2fs_gc_kthread), GFP_KERNEL);
100 if (!gc_th) {
101 err = -ENOMEM;
102 goto out;
103 }
104
105 gc_th->min_sleep_time = DEF_GC_THREAD_MIN_SLEEP_TIME;
106 gc_th->max_sleep_time = DEF_GC_THREAD_MAX_SLEEP_TIME;
107 gc_th->no_gc_sleep_time = DEF_GC_THREAD_NOGC_SLEEP_TIME;
108
109 gc_th->gc_idle = 0;
110
111 sbi->gc_thread = gc_th;
112 init_waitqueue_head(&sbi->gc_thread->gc_wait_queue_head);
113 sbi->gc_thread->f2fs_gc_task = kthread_run(gc_thread_func, sbi,
114 "f2fs_gc-%u:%u", MAJOR(dev), MINOR(dev));
115 if (IS_ERR(gc_th->f2fs_gc_task)) {
116 err = PTR_ERR(gc_th->f2fs_gc_task);
117 kfree(gc_th);
118 sbi->gc_thread = NULL;
119 }
120 out:
121 return err;
122 }
123
124 void stop_gc_thread(struct f2fs_sb_info *sbi)
125 {
126 struct f2fs_gc_kthread *gc_th = sbi->gc_thread;
127 if (!gc_th)
128 return;
129 kthread_stop(gc_th->f2fs_gc_task);
130 kfree(gc_th);
131 sbi->gc_thread = NULL;
132 }
133
134 static int select_gc_type(struct f2fs_gc_kthread *gc_th, int gc_type)
135 {
136 int gc_mode = (gc_type == BG_GC) ? GC_CB : GC_GREEDY;
137
138 if (gc_th && gc_th->gc_idle) {
139 if (gc_th->gc_idle == 1)
140 gc_mode = GC_CB;
141 else if (gc_th->gc_idle == 2)
142 gc_mode = GC_GREEDY;
143 }
144 return gc_mode;
145 }
146
147 static void select_policy(struct f2fs_sb_info *sbi, int gc_type,
148 int type, struct victim_sel_policy *p)
149 {
150 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
151
152 if (p->alloc_mode == SSR) {
153 p->gc_mode = GC_GREEDY;
154 p->dirty_segmap = dirty_i->dirty_segmap[type];
155 p->max_search = dirty_i->nr_dirty[type];
156 p->ofs_unit = 1;
157 } else {
158 p->gc_mode = select_gc_type(sbi->gc_thread, gc_type);
159 p->dirty_segmap = dirty_i->dirty_segmap[DIRTY];
160 p->max_search = dirty_i->nr_dirty[DIRTY];
161 p->ofs_unit = sbi->segs_per_sec;
162 }
163
164 if (p->max_search > sbi->max_victim_search)
165 p->max_search = sbi->max_victim_search;
166
167 p->offset = sbi->last_victim[p->gc_mode];
168 }
169
170 static unsigned int get_max_cost(struct f2fs_sb_info *sbi,
171 struct victim_sel_policy *p)
172 {
173 /* SSR allocates in a segment unit */
174 if (p->alloc_mode == SSR)
175 return sbi->blocks_per_seg;
176 if (p->gc_mode == GC_GREEDY)
177 return sbi->blocks_per_seg * p->ofs_unit;
178 else if (p->gc_mode == GC_CB)
179 return UINT_MAX;
180 else /* No other gc_mode */
181 return 0;
182 }
183
184 static unsigned int check_bg_victims(struct f2fs_sb_info *sbi)
185 {
186 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
187 unsigned int secno;
188
189 /*
190 * If the gc_type is FG_GC, we can select victim segments
191 * selected by background GC before.
192 * Those segments guarantee they have small valid blocks.
193 */
194 for_each_set_bit(secno, dirty_i->victim_secmap, MAIN_SECS(sbi)) {
195 if (sec_usage_check(sbi, secno))
196 continue;
197 clear_bit(secno, dirty_i->victim_secmap);
198 return secno * sbi->segs_per_sec;
199 }
200 return NULL_SEGNO;
201 }
202
203 static unsigned int get_cb_cost(struct f2fs_sb_info *sbi, unsigned int segno)
204 {
205 struct sit_info *sit_i = SIT_I(sbi);
206 unsigned int secno = GET_SECNO(sbi, segno);
207 unsigned int start = secno * sbi->segs_per_sec;
208 unsigned long long mtime = 0;
209 unsigned int vblocks;
210 unsigned char age = 0;
211 unsigned char u;
212 unsigned int i;
213
214 for (i = 0; i < sbi->segs_per_sec; i++)
215 mtime += get_seg_entry(sbi, start + i)->mtime;
216 vblocks = get_valid_blocks(sbi, segno, sbi->segs_per_sec);
217
218 mtime = div_u64(mtime, sbi->segs_per_sec);
219 vblocks = div_u64(vblocks, sbi->segs_per_sec);
220
221 u = (vblocks * 100) >> sbi->log_blocks_per_seg;
222
223 /* Handle if the system time has changed by the user */
224 if (mtime < sit_i->min_mtime)
225 sit_i->min_mtime = mtime;
226 if (mtime > sit_i->max_mtime)
227 sit_i->max_mtime = mtime;
228 if (sit_i->max_mtime != sit_i->min_mtime)
229 age = 100 - div64_u64(100 * (mtime - sit_i->min_mtime),
230 sit_i->max_mtime - sit_i->min_mtime);
231
232 return UINT_MAX - ((100 * (100 - u) * age) / (100 + u));
233 }
234
235 static inline unsigned int get_gc_cost(struct f2fs_sb_info *sbi,
236 unsigned int segno, struct victim_sel_policy *p)
237 {
238 if (p->alloc_mode == SSR)
239 return get_seg_entry(sbi, segno)->ckpt_valid_blocks;
240
241 /* alloc_mode == LFS */
242 if (p->gc_mode == GC_GREEDY)
243 return get_valid_blocks(sbi, segno, sbi->segs_per_sec);
244 else
245 return get_cb_cost(sbi, segno);
246 }
247
248 static unsigned int count_bits(const unsigned long *addr,
249 unsigned int offset, unsigned int len)
250 {
251 unsigned int end = offset + len, sum = 0;
252
253 while (offset < end) {
254 if (test_bit(offset++, addr))
255 ++sum;
256 }
257 return sum;
258 }
259
260 /*
261 * This function is called from two paths.
262 * One is garbage collection and the other is SSR segment selection.
263 * When it is called during GC, it just gets a victim segment
264 * and it does not remove it from dirty seglist.
265 * When it is called from SSR segment selection, it finds a segment
266 * which has minimum valid blocks and removes it from dirty seglist.
267 */
268 static int get_victim_by_default(struct f2fs_sb_info *sbi,
269 unsigned int *result, int gc_type, int type, char alloc_mode)
270 {
271 struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
272 struct victim_sel_policy p;
273 unsigned int secno, max_cost, last_victim;
274 unsigned int last_segment = MAIN_SEGS(sbi);
275 unsigned int nsearched = 0;
276
277 mutex_lock(&dirty_i->seglist_lock);
278
279 p.alloc_mode = alloc_mode;
280 select_policy(sbi, gc_type, type, &p);
281
282 p.min_segno = NULL_SEGNO;
283 p.min_cost = max_cost = get_max_cost(sbi, &p);
284
285 if (p.max_search == 0)
286 goto out;
287
288 last_victim = sbi->last_victim[p.gc_mode];
289 if (p.alloc_mode == LFS && gc_type == FG_GC) {
290 p.min_segno = check_bg_victims(sbi);
291 if (p.min_segno != NULL_SEGNO)
292 goto got_it;
293 }
294
295 while (1) {
296 unsigned long cost;
297 unsigned int segno;
298
299 segno = find_next_bit(p.dirty_segmap, last_segment, p.offset);
300 if (segno >= last_segment) {
301 if (sbi->last_victim[p.gc_mode]) {
302 last_segment = sbi->last_victim[p.gc_mode];
303 sbi->last_victim[p.gc_mode] = 0;
304 p.offset = 0;
305 continue;
306 }
307 break;
308 }
309
310 p.offset = segno + p.ofs_unit;
311 if (p.ofs_unit > 1) {
312 p.offset -= segno % p.ofs_unit;
313 nsearched += count_bits(p.dirty_segmap,
314 p.offset - p.ofs_unit,
315 p.ofs_unit);
316 } else {
317 nsearched++;
318 }
319
320
321 secno = GET_SECNO(sbi, segno);
322
323 if (sec_usage_check(sbi, secno))
324 goto next;
325 if (gc_type == BG_GC && test_bit(secno, dirty_i->victim_secmap))
326 goto next;
327
328 cost = get_gc_cost(sbi, segno, &p);
329
330 if (p.min_cost > cost) {
331 p.min_segno = segno;
332 p.min_cost = cost;
333 }
334 next:
335 if (nsearched >= p.max_search) {
336 if (!sbi->last_victim[p.gc_mode] && segno <= last_victim)
337 sbi->last_victim[p.gc_mode] = last_victim + 1;
338 else
339 sbi->last_victim[p.gc_mode] = segno + 1;
340 break;
341 }
342 }
343 if (p.min_segno != NULL_SEGNO) {
344 got_it:
345 if (p.alloc_mode == LFS) {
346 secno = GET_SECNO(sbi, p.min_segno);
347 if (gc_type == FG_GC)
348 sbi->cur_victim_sec = secno;
349 else
350 set_bit(secno, dirty_i->victim_secmap);
351 }
352 *result = (p.min_segno / p.ofs_unit) * p.ofs_unit;
353
354 trace_f2fs_get_victim(sbi->sb, type, gc_type, &p,
355 sbi->cur_victim_sec,
356 prefree_segments(sbi), free_segments(sbi));
357 }
358 out:
359 mutex_unlock(&dirty_i->seglist_lock);
360
361 return (p.min_segno == NULL_SEGNO) ? 0 : 1;
362 }
363
364 static const struct victim_selection default_v_ops = {
365 .get_victim = get_victim_by_default,
366 };
367
368 static struct inode *find_gc_inode(struct gc_inode_list *gc_list, nid_t ino)
369 {
370 struct inode_entry *ie;
371
372 ie = radix_tree_lookup(&gc_list->iroot, ino);
373 if (ie)
374 return ie->inode;
375 return NULL;
376 }
377
378 static void add_gc_inode(struct gc_inode_list *gc_list, struct inode *inode)
379 {
380 struct inode_entry *new_ie;
381
382 if (inode == find_gc_inode(gc_list, inode->i_ino)) {
383 iput(inode);
384 return;
385 }
386 new_ie = f2fs_kmem_cache_alloc(inode_entry_slab, GFP_NOFS);
387 new_ie->inode = inode;
388
389 f2fs_radix_tree_insert(&gc_list->iroot, inode->i_ino, new_ie);
390 list_add_tail(&new_ie->list, &gc_list->ilist);
391 }
392
393 static void put_gc_inode(struct gc_inode_list *gc_list)
394 {
395 struct inode_entry *ie, *next_ie;
396 list_for_each_entry_safe(ie, next_ie, &gc_list->ilist, list) {
397 radix_tree_delete(&gc_list->iroot, ie->inode->i_ino);
398 iput(ie->inode);
399 list_del(&ie->list);
400 kmem_cache_free(inode_entry_slab, ie);
401 }
402 }
403
404 static int check_valid_map(struct f2fs_sb_info *sbi,
405 unsigned int segno, int offset)
406 {
407 struct sit_info *sit_i = SIT_I(sbi);
408 struct seg_entry *sentry;
409 int ret;
410
411 mutex_lock(&sit_i->sentry_lock);
412 sentry = get_seg_entry(sbi, segno);
413 ret = f2fs_test_bit(offset, sentry->cur_valid_map);
414 mutex_unlock(&sit_i->sentry_lock);
415 return ret;
416 }
417
418 /*
419 * This function compares node address got in summary with that in NAT.
420 * On validity, copy that node with cold status, otherwise (invalid node)
421 * ignore that.
422 */
423 static void gc_node_segment(struct f2fs_sb_info *sbi,
424 struct f2fs_summary *sum, unsigned int segno, int gc_type)
425 {
426 bool initial = true;
427 struct f2fs_summary *entry;
428 block_t start_addr;
429 int off;
430
431 start_addr = START_BLOCK(sbi, segno);
432
433 next_step:
434 entry = sum;
435
436 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
437 nid_t nid = le32_to_cpu(entry->nid);
438 struct page *node_page;
439 struct node_info ni;
440
441 /* stop BG_GC if there is not enough free sections. */
442 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
443 return;
444
445 if (check_valid_map(sbi, segno, off) == 0)
446 continue;
447
448 if (initial) {
449 ra_node_page(sbi, nid);
450 continue;
451 }
452 node_page = get_node_page(sbi, nid);
453 if (IS_ERR(node_page))
454 continue;
455
456 /* block may become invalid during get_node_page */
457 if (check_valid_map(sbi, segno, off) == 0) {
458 f2fs_put_page(node_page, 1);
459 continue;
460 }
461
462 get_node_info(sbi, nid, &ni);
463 if (ni.blk_addr != start_addr + off) {
464 f2fs_put_page(node_page, 1);
465 continue;
466 }
467
468 move_node_page(node_page, gc_type);
469 stat_inc_node_blk_count(sbi, 1, gc_type);
470 }
471
472 if (initial) {
473 initial = false;
474 goto next_step;
475 }
476 }
477
478 /*
479 * Calculate start block index indicating the given node offset.
480 * Be careful, caller should give this node offset only indicating direct node
481 * blocks. If any node offsets, which point the other types of node blocks such
482 * as indirect or double indirect node blocks, are given, it must be a caller's
483 * bug.
484 */
485 block_t start_bidx_of_node(unsigned int node_ofs, struct inode *inode)
486 {
487 unsigned int indirect_blks = 2 * NIDS_PER_BLOCK + 4;
488 unsigned int bidx;
489
490 if (node_ofs == 0)
491 return 0;
492
493 if (node_ofs <= 2) {
494 bidx = node_ofs - 1;
495 } else if (node_ofs <= indirect_blks) {
496 int dec = (node_ofs - 4) / (NIDS_PER_BLOCK + 1);
497 bidx = node_ofs - 2 - dec;
498 } else {
499 int dec = (node_ofs - indirect_blks - 3) / (NIDS_PER_BLOCK + 1);
500 bidx = node_ofs - 5 - dec;
501 }
502 return bidx * ADDRS_PER_BLOCK + ADDRS_PER_INODE(inode);
503 }
504
505 static bool is_alive(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
506 struct node_info *dni, block_t blkaddr, unsigned int *nofs)
507 {
508 struct page *node_page;
509 nid_t nid;
510 unsigned int ofs_in_node;
511 block_t source_blkaddr;
512
513 nid = le32_to_cpu(sum->nid);
514 ofs_in_node = le16_to_cpu(sum->ofs_in_node);
515
516 node_page = get_node_page(sbi, nid);
517 if (IS_ERR(node_page))
518 return false;
519
520 get_node_info(sbi, nid, dni);
521
522 if (sum->version != dni->version) {
523 f2fs_put_page(node_page, 1);
524 return false;
525 }
526
527 *nofs = ofs_of_node(node_page);
528 source_blkaddr = datablock_addr(node_page, ofs_in_node);
529 f2fs_put_page(node_page, 1);
530
531 if (source_blkaddr != blkaddr)
532 return false;
533 return true;
534 }
535
536 static void move_encrypted_block(struct inode *inode, block_t bidx)
537 {
538 struct f2fs_io_info fio = {
539 .sbi = F2FS_I_SB(inode),
540 .type = DATA,
541 .op = REQ_OP_READ,
542 .op_flags = READ_SYNC,
543 .encrypted_page = NULL,
544 };
545 struct dnode_of_data dn;
546 struct f2fs_summary sum;
547 struct node_info ni;
548 struct page *page;
549 block_t newaddr;
550 int err;
551
552 /* do not read out */
553 page = f2fs_grab_cache_page(inode->i_mapping, bidx, false);
554 if (!page)
555 return;
556
557 set_new_dnode(&dn, inode, NULL, NULL, 0);
558 err = get_dnode_of_data(&dn, bidx, LOOKUP_NODE);
559 if (err)
560 goto out;
561
562 if (unlikely(dn.data_blkaddr == NULL_ADDR)) {
563 ClearPageUptodate(page);
564 goto put_out;
565 }
566
567 /*
568 * don't cache encrypted data into meta inode until previous dirty
569 * data were writebacked to avoid racing between GC and flush.
570 */
571 f2fs_wait_on_page_writeback(page, DATA, true);
572
573 get_node_info(fio.sbi, dn.nid, &ni);
574 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
575
576 /* read page */
577 fio.page = page;
578 fio.new_blkaddr = fio.old_blkaddr = dn.data_blkaddr;
579
580 allocate_data_block(fio.sbi, NULL, fio.old_blkaddr, &newaddr,
581 &sum, CURSEG_COLD_DATA);
582
583 fio.encrypted_page = pagecache_get_page(META_MAPPING(fio.sbi), newaddr,
584 FGP_LOCK | FGP_CREAT, GFP_NOFS);
585 if (!fio.encrypted_page) {
586 err = -ENOMEM;
587 goto recover_block;
588 }
589
590 err = f2fs_submit_page_bio(&fio);
591 if (err)
592 goto put_page_out;
593
594 /* write page */
595 lock_page(fio.encrypted_page);
596
597 if (unlikely(fio.encrypted_page->mapping != META_MAPPING(fio.sbi))) {
598 err = -EIO;
599 goto put_page_out;
600 }
601 if (unlikely(!PageUptodate(fio.encrypted_page))) {
602 err = -EIO;
603 goto put_page_out;
604 }
605
606 set_page_dirty(fio.encrypted_page);
607 f2fs_wait_on_page_writeback(fio.encrypted_page, DATA, true);
608 if (clear_page_dirty_for_io(fio.encrypted_page))
609 dec_page_count(fio.sbi, F2FS_DIRTY_META);
610
611 set_page_writeback(fio.encrypted_page);
612
613 /* allocate block address */
614 f2fs_wait_on_page_writeback(dn.node_page, NODE, true);
615
616 fio.op = REQ_OP_WRITE;
617 fio.op_flags = WRITE_SYNC;
618 fio.new_blkaddr = newaddr;
619 f2fs_submit_page_mbio(&fio);
620
621 f2fs_update_data_blkaddr(&dn, newaddr);
622 set_inode_flag(inode, FI_APPEND_WRITE);
623 if (page->index == 0)
624 set_inode_flag(inode, FI_FIRST_BLOCK_WRITTEN);
625 put_page_out:
626 f2fs_put_page(fio.encrypted_page, 1);
627 recover_block:
628 if (err)
629 __f2fs_replace_block(fio.sbi, &sum, newaddr, fio.old_blkaddr,
630 true, true);
631 put_out:
632 f2fs_put_dnode(&dn);
633 out:
634 f2fs_put_page(page, 1);
635 }
636
637 static void move_data_page(struct inode *inode, block_t bidx, int gc_type)
638 {
639 struct page *page;
640
641 page = get_lock_data_page(inode, bidx, true);
642 if (IS_ERR(page))
643 return;
644
645 if (gc_type == BG_GC) {
646 if (PageWriteback(page))
647 goto out;
648 set_page_dirty(page);
649 set_cold_data(page);
650 } else {
651 struct f2fs_io_info fio = {
652 .sbi = F2FS_I_SB(inode),
653 .type = DATA,
654 .op = REQ_OP_WRITE,
655 .op_flags = WRITE_SYNC,
656 .page = page,
657 .encrypted_page = NULL,
658 };
659 bool is_dirty = PageDirty(page);
660 int err;
661
662 retry:
663 set_page_dirty(page);
664 f2fs_wait_on_page_writeback(page, DATA, true);
665 if (clear_page_dirty_for_io(page))
666 inode_dec_dirty_pages(inode);
667
668 set_cold_data(page);
669
670 err = do_write_data_page(&fio);
671 if (err == -ENOMEM && is_dirty) {
672 congestion_wait(BLK_RW_ASYNC, HZ/50);
673 goto retry;
674 }
675
676 clear_cold_data(page);
677 }
678 out:
679 f2fs_put_page(page, 1);
680 }
681
682 /*
683 * This function tries to get parent node of victim data block, and identifies
684 * data block validity. If the block is valid, copy that with cold status and
685 * modify parent node.
686 * If the parent node is not valid or the data block address is different,
687 * the victim data block is ignored.
688 */
689 static void gc_data_segment(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
690 struct gc_inode_list *gc_list, unsigned int segno, int gc_type)
691 {
692 struct super_block *sb = sbi->sb;
693 struct f2fs_summary *entry;
694 block_t start_addr;
695 int off;
696 int phase = 0;
697
698 start_addr = START_BLOCK(sbi, segno);
699
700 next_step:
701 entry = sum;
702
703 for (off = 0; off < sbi->blocks_per_seg; off++, entry++) {
704 struct page *data_page;
705 struct inode *inode;
706 struct node_info dni; /* dnode info for the data */
707 unsigned int ofs_in_node, nofs;
708 block_t start_bidx;
709
710 /* stop BG_GC if there is not enough free sections. */
711 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, 0))
712 return;
713
714 if (check_valid_map(sbi, segno, off) == 0)
715 continue;
716
717 if (phase == 0) {
718 ra_node_page(sbi, le32_to_cpu(entry->nid));
719 continue;
720 }
721
722 /* Get an inode by ino with checking validity */
723 if (!is_alive(sbi, entry, &dni, start_addr + off, &nofs))
724 continue;
725
726 if (phase == 1) {
727 ra_node_page(sbi, dni.ino);
728 continue;
729 }
730
731 ofs_in_node = le16_to_cpu(entry->ofs_in_node);
732
733 if (phase == 2) {
734 inode = f2fs_iget(sb, dni.ino);
735 if (IS_ERR(inode) || is_bad_inode(inode))
736 continue;
737
738 /* if encrypted inode, let's go phase 3 */
739 if (f2fs_encrypted_inode(inode) &&
740 S_ISREG(inode->i_mode)) {
741 add_gc_inode(gc_list, inode);
742 continue;
743 }
744
745 start_bidx = start_bidx_of_node(nofs, inode);
746 data_page = get_read_data_page(inode,
747 start_bidx + ofs_in_node, REQ_RAHEAD,
748 true);
749 if (IS_ERR(data_page)) {
750 iput(inode);
751 continue;
752 }
753
754 f2fs_put_page(data_page, 0);
755 add_gc_inode(gc_list, inode);
756 continue;
757 }
758
759 /* phase 3 */
760 inode = find_gc_inode(gc_list, dni.ino);
761 if (inode) {
762 struct f2fs_inode_info *fi = F2FS_I(inode);
763 bool locked = false;
764
765 if (S_ISREG(inode->i_mode)) {
766 if (!down_write_trylock(&fi->dio_rwsem[READ]))
767 continue;
768 if (!down_write_trylock(
769 &fi->dio_rwsem[WRITE])) {
770 up_write(&fi->dio_rwsem[READ]);
771 continue;
772 }
773 locked = true;
774 }
775
776 start_bidx = start_bidx_of_node(nofs, inode)
777 + ofs_in_node;
778 if (f2fs_encrypted_inode(inode) && S_ISREG(inode->i_mode))
779 move_encrypted_block(inode, start_bidx);
780 else
781 move_data_page(inode, start_bidx, gc_type);
782
783 if (locked) {
784 up_write(&fi->dio_rwsem[WRITE]);
785 up_write(&fi->dio_rwsem[READ]);
786 }
787
788 stat_inc_data_blk_count(sbi, 1, gc_type);
789 }
790 }
791
792 if (++phase < 4)
793 goto next_step;
794 }
795
796 static int __get_victim(struct f2fs_sb_info *sbi, unsigned int *victim,
797 int gc_type)
798 {
799 struct sit_info *sit_i = SIT_I(sbi);
800 int ret;
801
802 mutex_lock(&sit_i->sentry_lock);
803 ret = DIRTY_I(sbi)->v_ops->get_victim(sbi, victim, gc_type,
804 NO_CHECK_TYPE, LFS);
805 mutex_unlock(&sit_i->sentry_lock);
806 return ret;
807 }
808
809 static int do_garbage_collect(struct f2fs_sb_info *sbi,
810 unsigned int start_segno,
811 struct gc_inode_list *gc_list, int gc_type)
812 {
813 struct page *sum_page;
814 struct f2fs_summary_block *sum;
815 struct blk_plug plug;
816 unsigned int segno = start_segno;
817 unsigned int end_segno = start_segno + sbi->segs_per_sec;
818 int sec_freed = 0;
819 unsigned char type = IS_DATASEG(get_seg_entry(sbi, segno)->type) ?
820 SUM_TYPE_DATA : SUM_TYPE_NODE;
821
822 /* readahead multi ssa blocks those have contiguous address */
823 if (sbi->segs_per_sec > 1)
824 ra_meta_pages(sbi, GET_SUM_BLOCK(sbi, segno),
825 sbi->segs_per_sec, META_SSA, true);
826
827 /* reference all summary page */
828 while (segno < end_segno) {
829 sum_page = get_sum_page(sbi, segno++);
830 unlock_page(sum_page);
831 }
832
833 blk_start_plug(&plug);
834
835 for (segno = start_segno; segno < end_segno; segno++) {
836
837 if (get_valid_blocks(sbi, segno, 1) == 0)
838 continue;
839
840 /* find segment summary of victim */
841 sum_page = find_get_page(META_MAPPING(sbi),
842 GET_SUM_BLOCK(sbi, segno));
843 f2fs_bug_on(sbi, !PageUptodate(sum_page));
844 f2fs_put_page(sum_page, 0);
845
846 sum = page_address(sum_page);
847 f2fs_bug_on(sbi, type != GET_SUM_TYPE((&sum->footer)));
848
849 /*
850 * this is to avoid deadlock:
851 * - lock_page(sum_page) - f2fs_replace_block
852 * - check_valid_map() - mutex_lock(sentry_lock)
853 * - mutex_lock(sentry_lock) - change_curseg()
854 * - lock_page(sum_page)
855 */
856
857 if (type == SUM_TYPE_NODE)
858 gc_node_segment(sbi, sum->entries, segno, gc_type);
859 else
860 gc_data_segment(sbi, sum->entries, gc_list, segno,
861 gc_type);
862
863 stat_inc_seg_count(sbi, type, gc_type);
864
865 f2fs_put_page(sum_page, 0);
866 }
867
868 if (gc_type == FG_GC)
869 f2fs_submit_merged_bio(sbi,
870 (type == SUM_TYPE_NODE) ? NODE : DATA, WRITE);
871
872 blk_finish_plug(&plug);
873
874 if (gc_type == FG_GC &&
875 get_valid_blocks(sbi, start_segno, sbi->segs_per_sec) == 0)
876 sec_freed = 1;
877
878 stat_inc_call_count(sbi->stat_info);
879
880 return sec_freed;
881 }
882
883 int f2fs_gc(struct f2fs_sb_info *sbi, bool sync)
884 {
885 unsigned int segno;
886 int gc_type = sync ? FG_GC : BG_GC;
887 int sec_freed = 0;
888 int ret = -EINVAL;
889 struct cp_control cpc;
890 struct gc_inode_list gc_list = {
891 .ilist = LIST_HEAD_INIT(gc_list.ilist),
892 .iroot = RADIX_TREE_INIT(GFP_NOFS),
893 };
894
895 cpc.reason = __get_cp_reason(sbi);
896 gc_more:
897 segno = NULL_SEGNO;
898
899 if (unlikely(!(sbi->sb->s_flags & MS_ACTIVE)))
900 goto stop;
901 if (unlikely(f2fs_cp_error(sbi))) {
902 ret = -EIO;
903 goto stop;
904 }
905
906 if (gc_type == BG_GC && has_not_enough_free_secs(sbi, sec_freed)) {
907 gc_type = FG_GC;
908 /*
909 * If there is no victim and no prefree segment but still not
910 * enough free sections, we should flush dent/node blocks and do
911 * garbage collections.
912 */
913 if (__get_victim(sbi, &segno, gc_type) ||
914 prefree_segments(sbi)) {
915 write_checkpoint(sbi, &cpc);
916 segno = NULL_SEGNO;
917 } else if (has_not_enough_free_secs(sbi, 0)) {
918 write_checkpoint(sbi, &cpc);
919 }
920 }
921
922 if (segno == NULL_SEGNO && !__get_victim(sbi, &segno, gc_type))
923 goto stop;
924 ret = 0;
925
926 if (do_garbage_collect(sbi, segno, &gc_list, gc_type) &&
927 gc_type == FG_GC)
928 sec_freed++;
929
930 if (gc_type == FG_GC)
931 sbi->cur_victim_sec = NULL_SEGNO;
932
933 if (!sync) {
934 if (has_not_enough_free_secs(sbi, sec_freed))
935 goto gc_more;
936
937 if (gc_type == FG_GC)
938 write_checkpoint(sbi, &cpc);
939 }
940 stop:
941 mutex_unlock(&sbi->gc_mutex);
942
943 put_gc_inode(&gc_list);
944
945 if (sync)
946 ret = sec_freed ? 0 : -EAGAIN;
947 return ret;
948 }
949
950 void build_gc_manager(struct f2fs_sb_info *sbi)
951 {
952 DIRTY_I(sbi)->v_ops = &default_v_ops;
953 }
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