xref: /openbmc/linux/fs/f2fs/segment.c (revision b34e08d5)
1 /*
2  * fs/f2fs/segment.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/f2fs_fs.h>
13 #include <linux/bio.h>
14 #include <linux/blkdev.h>
15 #include <linux/prefetch.h>
16 #include <linux/kthread.h>
17 #include <linux/vmalloc.h>
18 #include <linux/swap.h>
19 
20 #include "f2fs.h"
21 #include "segment.h"
22 #include "node.h"
23 #include <trace/events/f2fs.h>
24 
25 #define __reverse_ffz(x) __reverse_ffs(~(x))
26 
27 static struct kmem_cache *discard_entry_slab;
28 static struct kmem_cache *flush_cmd_slab;
29 
30 /*
31  * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
32  * MSB and LSB are reversed in a byte by f2fs_set_bit.
33  */
34 static inline unsigned long __reverse_ffs(unsigned long word)
35 {
36 	int num = 0;
37 
38 #if BITS_PER_LONG == 64
39 	if ((word & 0xffffffff) == 0) {
40 		num += 32;
41 		word >>= 32;
42 	}
43 #endif
44 	if ((word & 0xffff) == 0) {
45 		num += 16;
46 		word >>= 16;
47 	}
48 	if ((word & 0xff) == 0) {
49 		num += 8;
50 		word >>= 8;
51 	}
52 	if ((word & 0xf0) == 0)
53 		num += 4;
54 	else
55 		word >>= 4;
56 	if ((word & 0xc) == 0)
57 		num += 2;
58 	else
59 		word >>= 2;
60 	if ((word & 0x2) == 0)
61 		num += 1;
62 	return num;
63 }
64 
65 /*
66  * __find_rev_next(_zero)_bit is copied from lib/find_next_bit.c becasue
67  * f2fs_set_bit makes MSB and LSB reversed in a byte.
68  * Example:
69  *                             LSB <--> MSB
70  *   f2fs_set_bit(0, bitmap) => 0000 0001
71  *   f2fs_set_bit(7, bitmap) => 1000 0000
72  */
73 static unsigned long __find_rev_next_bit(const unsigned long *addr,
74 			unsigned long size, unsigned long offset)
75 {
76 	const unsigned long *p = addr + BIT_WORD(offset);
77 	unsigned long result = offset & ~(BITS_PER_LONG - 1);
78 	unsigned long tmp;
79 	unsigned long mask, submask;
80 	unsigned long quot, rest;
81 
82 	if (offset >= size)
83 		return size;
84 
85 	size -= result;
86 	offset %= BITS_PER_LONG;
87 	if (!offset)
88 		goto aligned;
89 
90 	tmp = *(p++);
91 	quot = (offset >> 3) << 3;
92 	rest = offset & 0x7;
93 	mask = ~0UL << quot;
94 	submask = (unsigned char)(0xff << rest) >> rest;
95 	submask <<= quot;
96 	mask &= submask;
97 	tmp &= mask;
98 	if (size < BITS_PER_LONG)
99 		goto found_first;
100 	if (tmp)
101 		goto found_middle;
102 
103 	size -= BITS_PER_LONG;
104 	result += BITS_PER_LONG;
105 aligned:
106 	while (size & ~(BITS_PER_LONG-1)) {
107 		tmp = *(p++);
108 		if (tmp)
109 			goto found_middle;
110 		result += BITS_PER_LONG;
111 		size -= BITS_PER_LONG;
112 	}
113 	if (!size)
114 		return result;
115 	tmp = *p;
116 found_first:
117 	tmp &= (~0UL >> (BITS_PER_LONG - size));
118 	if (tmp == 0UL)		/* Are any bits set? */
119 		return result + size;   /* Nope. */
120 found_middle:
121 	return result + __reverse_ffs(tmp);
122 }
123 
124 static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
125 			unsigned long size, unsigned long offset)
126 {
127 	const unsigned long *p = addr + BIT_WORD(offset);
128 	unsigned long result = offset & ~(BITS_PER_LONG - 1);
129 	unsigned long tmp;
130 	unsigned long mask, submask;
131 	unsigned long quot, rest;
132 
133 	if (offset >= size)
134 		return size;
135 
136 	size -= result;
137 	offset %= BITS_PER_LONG;
138 	if (!offset)
139 		goto aligned;
140 
141 	tmp = *(p++);
142 	quot = (offset >> 3) << 3;
143 	rest = offset & 0x7;
144 	mask = ~(~0UL << quot);
145 	submask = (unsigned char)~((unsigned char)(0xff << rest) >> rest);
146 	submask <<= quot;
147 	mask += submask;
148 	tmp |= mask;
149 	if (size < BITS_PER_LONG)
150 		goto found_first;
151 	if (~tmp)
152 		goto found_middle;
153 
154 	size -= BITS_PER_LONG;
155 	result += BITS_PER_LONG;
156 aligned:
157 	while (size & ~(BITS_PER_LONG - 1)) {
158 		tmp = *(p++);
159 		if (~tmp)
160 			goto found_middle;
161 		result += BITS_PER_LONG;
162 		size -= BITS_PER_LONG;
163 	}
164 	if (!size)
165 		return result;
166 	tmp = *p;
167 
168 found_first:
169 	tmp |= ~0UL << size;
170 	if (tmp == ~0UL)        /* Are any bits zero? */
171 		return result + size;   /* Nope. */
172 found_middle:
173 	return result + __reverse_ffz(tmp);
174 }
175 
176 /*
177  * This function balances dirty node and dentry pages.
178  * In addition, it controls garbage collection.
179  */
180 void f2fs_balance_fs(struct f2fs_sb_info *sbi)
181 {
182 	/*
183 	 * We should do GC or end up with checkpoint, if there are so many dirty
184 	 * dir/node pages without enough free segments.
185 	 */
186 	if (has_not_enough_free_secs(sbi, 0)) {
187 		mutex_lock(&sbi->gc_mutex);
188 		f2fs_gc(sbi);
189 	}
190 }
191 
192 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
193 {
194 	/* check the # of cached NAT entries and prefree segments */
195 	if (try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK) ||
196 				excess_prefree_segs(sbi))
197 		f2fs_sync_fs(sbi->sb, true);
198 }
199 
200 static int issue_flush_thread(void *data)
201 {
202 	struct f2fs_sb_info *sbi = data;
203 	struct f2fs_sm_info *sm_i = SM_I(sbi);
204 	wait_queue_head_t *q = &sm_i->flush_wait_queue;
205 repeat:
206 	if (kthread_should_stop())
207 		return 0;
208 
209 	spin_lock(&sm_i->issue_lock);
210 	if (sm_i->issue_list) {
211 		sm_i->dispatch_list = sm_i->issue_list;
212 		sm_i->issue_list = sm_i->issue_tail = NULL;
213 	}
214 	spin_unlock(&sm_i->issue_lock);
215 
216 	if (sm_i->dispatch_list) {
217 		struct bio *bio = bio_alloc(GFP_NOIO, 0);
218 		struct flush_cmd *cmd, *next;
219 		int ret;
220 
221 		bio->bi_bdev = sbi->sb->s_bdev;
222 		ret = submit_bio_wait(WRITE_FLUSH, bio);
223 
224 		for (cmd = sm_i->dispatch_list; cmd; cmd = next) {
225 			cmd->ret = ret;
226 			next = cmd->next;
227 			complete(&cmd->wait);
228 		}
229 		sm_i->dispatch_list = NULL;
230 	}
231 
232 	wait_event_interruptible(*q, kthread_should_stop() || sm_i->issue_list);
233 	goto repeat;
234 }
235 
236 int f2fs_issue_flush(struct f2fs_sb_info *sbi)
237 {
238 	struct f2fs_sm_info *sm_i = SM_I(sbi);
239 	struct flush_cmd *cmd;
240 	int ret;
241 
242 	if (!test_opt(sbi, FLUSH_MERGE))
243 		return blkdev_issue_flush(sbi->sb->s_bdev, GFP_KERNEL, NULL);
244 
245 	cmd = f2fs_kmem_cache_alloc(flush_cmd_slab, GFP_ATOMIC);
246 	cmd->next = NULL;
247 	cmd->ret = 0;
248 	init_completion(&cmd->wait);
249 
250 	spin_lock(&sm_i->issue_lock);
251 	if (sm_i->issue_list)
252 		sm_i->issue_tail->next = cmd;
253 	else
254 		sm_i->issue_list = cmd;
255 	sm_i->issue_tail = cmd;
256 	spin_unlock(&sm_i->issue_lock);
257 
258 	if (!sm_i->dispatch_list)
259 		wake_up(&sm_i->flush_wait_queue);
260 
261 	wait_for_completion(&cmd->wait);
262 	ret = cmd->ret;
263 	kmem_cache_free(flush_cmd_slab, cmd);
264 	return ret;
265 }
266 
267 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
268 		enum dirty_type dirty_type)
269 {
270 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
271 
272 	/* need not be added */
273 	if (IS_CURSEG(sbi, segno))
274 		return;
275 
276 	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
277 		dirty_i->nr_dirty[dirty_type]++;
278 
279 	if (dirty_type == DIRTY) {
280 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
281 		enum dirty_type t = sentry->type;
282 
283 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
284 			dirty_i->nr_dirty[t]++;
285 	}
286 }
287 
288 static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
289 		enum dirty_type dirty_type)
290 {
291 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
292 
293 	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
294 		dirty_i->nr_dirty[dirty_type]--;
295 
296 	if (dirty_type == DIRTY) {
297 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
298 		enum dirty_type t = sentry->type;
299 
300 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
301 			dirty_i->nr_dirty[t]--;
302 
303 		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
304 			clear_bit(GET_SECNO(sbi, segno),
305 						dirty_i->victim_secmap);
306 	}
307 }
308 
309 /*
310  * Should not occur error such as -ENOMEM.
311  * Adding dirty entry into seglist is not critical operation.
312  * If a given segment is one of current working segments, it won't be added.
313  */
314 static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
315 {
316 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
317 	unsigned short valid_blocks;
318 
319 	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
320 		return;
321 
322 	mutex_lock(&dirty_i->seglist_lock);
323 
324 	valid_blocks = get_valid_blocks(sbi, segno, 0);
325 
326 	if (valid_blocks == 0) {
327 		__locate_dirty_segment(sbi, segno, PRE);
328 		__remove_dirty_segment(sbi, segno, DIRTY);
329 	} else if (valid_blocks < sbi->blocks_per_seg) {
330 		__locate_dirty_segment(sbi, segno, DIRTY);
331 	} else {
332 		/* Recovery routine with SSR needs this */
333 		__remove_dirty_segment(sbi, segno, DIRTY);
334 	}
335 
336 	mutex_unlock(&dirty_i->seglist_lock);
337 }
338 
339 static void f2fs_issue_discard(struct f2fs_sb_info *sbi,
340 				block_t blkstart, block_t blklen)
341 {
342 	sector_t start = SECTOR_FROM_BLOCK(sbi, blkstart);
343 	sector_t len = SECTOR_FROM_BLOCK(sbi, blklen);
344 	blkdev_issue_discard(sbi->sb->s_bdev, start, len, GFP_NOFS, 0);
345 	trace_f2fs_issue_discard(sbi->sb, blkstart, blklen);
346 }
347 
348 static void add_discard_addrs(struct f2fs_sb_info *sbi,
349 			unsigned int segno, struct seg_entry *se)
350 {
351 	struct list_head *head = &SM_I(sbi)->discard_list;
352 	struct discard_entry *new;
353 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
354 	int max_blocks = sbi->blocks_per_seg;
355 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
356 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
357 	unsigned long dmap[entries];
358 	unsigned int start = 0, end = -1;
359 	int i;
360 
361 	if (!test_opt(sbi, DISCARD))
362 		return;
363 
364 	/* zero block will be discarded through the prefree list */
365 	if (!se->valid_blocks || se->valid_blocks == max_blocks)
366 		return;
367 
368 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
369 	for (i = 0; i < entries; i++)
370 		dmap[i] = (cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
371 
372 	while (SM_I(sbi)->nr_discards <= SM_I(sbi)->max_discards) {
373 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
374 		if (start >= max_blocks)
375 			break;
376 
377 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
378 
379 		new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
380 		INIT_LIST_HEAD(&new->list);
381 		new->blkaddr = START_BLOCK(sbi, segno) + start;
382 		new->len = end - start;
383 
384 		list_add_tail(&new->list, head);
385 		SM_I(sbi)->nr_discards += end - start;
386 	}
387 }
388 
389 /*
390  * Should call clear_prefree_segments after checkpoint is done.
391  */
392 static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
393 {
394 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
395 	unsigned int segno = -1;
396 	unsigned int total_segs = TOTAL_SEGS(sbi);
397 
398 	mutex_lock(&dirty_i->seglist_lock);
399 	while (1) {
400 		segno = find_next_bit(dirty_i->dirty_segmap[PRE], total_segs,
401 				segno + 1);
402 		if (segno >= total_segs)
403 			break;
404 		__set_test_and_free(sbi, segno);
405 	}
406 	mutex_unlock(&dirty_i->seglist_lock);
407 }
408 
409 void clear_prefree_segments(struct f2fs_sb_info *sbi)
410 {
411 	struct list_head *head = &(SM_I(sbi)->discard_list);
412 	struct discard_entry *entry, *this;
413 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
414 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
415 	unsigned int total_segs = TOTAL_SEGS(sbi);
416 	unsigned int start = 0, end = -1;
417 
418 	mutex_lock(&dirty_i->seglist_lock);
419 
420 	while (1) {
421 		int i;
422 		start = find_next_bit(prefree_map, total_segs, end + 1);
423 		if (start >= total_segs)
424 			break;
425 		end = find_next_zero_bit(prefree_map, total_segs, start + 1);
426 
427 		for (i = start; i < end; i++)
428 			clear_bit(i, prefree_map);
429 
430 		dirty_i->nr_dirty[PRE] -= end - start;
431 
432 		if (!test_opt(sbi, DISCARD))
433 			continue;
434 
435 		f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
436 				(end - start) << sbi->log_blocks_per_seg);
437 	}
438 	mutex_unlock(&dirty_i->seglist_lock);
439 
440 	/* send small discards */
441 	list_for_each_entry_safe(entry, this, head, list) {
442 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
443 		list_del(&entry->list);
444 		SM_I(sbi)->nr_discards -= entry->len;
445 		kmem_cache_free(discard_entry_slab, entry);
446 	}
447 }
448 
449 static void __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
450 {
451 	struct sit_info *sit_i = SIT_I(sbi);
452 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap))
453 		sit_i->dirty_sentries++;
454 }
455 
456 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
457 					unsigned int segno, int modified)
458 {
459 	struct seg_entry *se = get_seg_entry(sbi, segno);
460 	se->type = type;
461 	if (modified)
462 		__mark_sit_entry_dirty(sbi, segno);
463 }
464 
465 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
466 {
467 	struct seg_entry *se;
468 	unsigned int segno, offset;
469 	long int new_vblocks;
470 
471 	segno = GET_SEGNO(sbi, blkaddr);
472 
473 	se = get_seg_entry(sbi, segno);
474 	new_vblocks = se->valid_blocks + del;
475 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
476 
477 	f2fs_bug_on((new_vblocks >> (sizeof(unsigned short) << 3) ||
478 				(new_vblocks > sbi->blocks_per_seg)));
479 
480 	se->valid_blocks = new_vblocks;
481 	se->mtime = get_mtime(sbi);
482 	SIT_I(sbi)->max_mtime = se->mtime;
483 
484 	/* Update valid block bitmap */
485 	if (del > 0) {
486 		if (f2fs_set_bit(offset, se->cur_valid_map))
487 			BUG();
488 	} else {
489 		if (!f2fs_clear_bit(offset, se->cur_valid_map))
490 			BUG();
491 	}
492 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
493 		se->ckpt_valid_blocks += del;
494 
495 	__mark_sit_entry_dirty(sbi, segno);
496 
497 	/* update total number of valid blocks to be written in ckpt area */
498 	SIT_I(sbi)->written_valid_blocks += del;
499 
500 	if (sbi->segs_per_sec > 1)
501 		get_sec_entry(sbi, segno)->valid_blocks += del;
502 }
503 
504 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
505 {
506 	update_sit_entry(sbi, new, 1);
507 	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
508 		update_sit_entry(sbi, old, -1);
509 
510 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
511 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
512 }
513 
514 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
515 {
516 	unsigned int segno = GET_SEGNO(sbi, addr);
517 	struct sit_info *sit_i = SIT_I(sbi);
518 
519 	f2fs_bug_on(addr == NULL_ADDR);
520 	if (addr == NEW_ADDR)
521 		return;
522 
523 	/* add it into sit main buffer */
524 	mutex_lock(&sit_i->sentry_lock);
525 
526 	update_sit_entry(sbi, addr, -1);
527 
528 	/* add it into dirty seglist */
529 	locate_dirty_segment(sbi, segno);
530 
531 	mutex_unlock(&sit_i->sentry_lock);
532 }
533 
534 /*
535  * This function should be resided under the curseg_mutex lock
536  */
537 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
538 					struct f2fs_summary *sum)
539 {
540 	struct curseg_info *curseg = CURSEG_I(sbi, type);
541 	void *addr = curseg->sum_blk;
542 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
543 	memcpy(addr, sum, sizeof(struct f2fs_summary));
544 }
545 
546 /*
547  * Calculate the number of current summary pages for writing
548  */
549 int npages_for_summary_flush(struct f2fs_sb_info *sbi)
550 {
551 	int valid_sum_count = 0;
552 	int i, sum_in_page;
553 
554 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
555 		if (sbi->ckpt->alloc_type[i] == SSR)
556 			valid_sum_count += sbi->blocks_per_seg;
557 		else
558 			valid_sum_count += curseg_blkoff(sbi, i);
559 	}
560 
561 	sum_in_page = (PAGE_CACHE_SIZE - 2 * SUM_JOURNAL_SIZE -
562 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
563 	if (valid_sum_count <= sum_in_page)
564 		return 1;
565 	else if ((valid_sum_count - sum_in_page) <=
566 		(PAGE_CACHE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
567 		return 2;
568 	return 3;
569 }
570 
571 /*
572  * Caller should put this summary page
573  */
574 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
575 {
576 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
577 }
578 
579 static void write_sum_page(struct f2fs_sb_info *sbi,
580 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
581 {
582 	struct page *page = grab_meta_page(sbi, blk_addr);
583 	void *kaddr = page_address(page);
584 	memcpy(kaddr, sum_blk, PAGE_CACHE_SIZE);
585 	set_page_dirty(page);
586 	f2fs_put_page(page, 1);
587 }
588 
589 static int is_next_segment_free(struct f2fs_sb_info *sbi, int type)
590 {
591 	struct curseg_info *curseg = CURSEG_I(sbi, type);
592 	unsigned int segno = curseg->segno + 1;
593 	struct free_segmap_info *free_i = FREE_I(sbi);
594 
595 	if (segno < TOTAL_SEGS(sbi) && segno % sbi->segs_per_sec)
596 		return !test_bit(segno, free_i->free_segmap);
597 	return 0;
598 }
599 
600 /*
601  * Find a new segment from the free segments bitmap to right order
602  * This function should be returned with success, otherwise BUG
603  */
604 static void get_new_segment(struct f2fs_sb_info *sbi,
605 			unsigned int *newseg, bool new_sec, int dir)
606 {
607 	struct free_segmap_info *free_i = FREE_I(sbi);
608 	unsigned int segno, secno, zoneno;
609 	unsigned int total_zones = TOTAL_SECS(sbi) / sbi->secs_per_zone;
610 	unsigned int hint = *newseg / sbi->segs_per_sec;
611 	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
612 	unsigned int left_start = hint;
613 	bool init = true;
614 	int go_left = 0;
615 	int i;
616 
617 	write_lock(&free_i->segmap_lock);
618 
619 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
620 		segno = find_next_zero_bit(free_i->free_segmap,
621 					TOTAL_SEGS(sbi), *newseg + 1);
622 		if (segno - *newseg < sbi->segs_per_sec -
623 					(*newseg % sbi->segs_per_sec))
624 			goto got_it;
625 	}
626 find_other_zone:
627 	secno = find_next_zero_bit(free_i->free_secmap, TOTAL_SECS(sbi), hint);
628 	if (secno >= TOTAL_SECS(sbi)) {
629 		if (dir == ALLOC_RIGHT) {
630 			secno = find_next_zero_bit(free_i->free_secmap,
631 							TOTAL_SECS(sbi), 0);
632 			f2fs_bug_on(secno >= TOTAL_SECS(sbi));
633 		} else {
634 			go_left = 1;
635 			left_start = hint - 1;
636 		}
637 	}
638 	if (go_left == 0)
639 		goto skip_left;
640 
641 	while (test_bit(left_start, free_i->free_secmap)) {
642 		if (left_start > 0) {
643 			left_start--;
644 			continue;
645 		}
646 		left_start = find_next_zero_bit(free_i->free_secmap,
647 							TOTAL_SECS(sbi), 0);
648 		f2fs_bug_on(left_start >= TOTAL_SECS(sbi));
649 		break;
650 	}
651 	secno = left_start;
652 skip_left:
653 	hint = secno;
654 	segno = secno * sbi->segs_per_sec;
655 	zoneno = secno / sbi->secs_per_zone;
656 
657 	/* give up on finding another zone */
658 	if (!init)
659 		goto got_it;
660 	if (sbi->secs_per_zone == 1)
661 		goto got_it;
662 	if (zoneno == old_zoneno)
663 		goto got_it;
664 	if (dir == ALLOC_LEFT) {
665 		if (!go_left && zoneno + 1 >= total_zones)
666 			goto got_it;
667 		if (go_left && zoneno == 0)
668 			goto got_it;
669 	}
670 	for (i = 0; i < NR_CURSEG_TYPE; i++)
671 		if (CURSEG_I(sbi, i)->zone == zoneno)
672 			break;
673 
674 	if (i < NR_CURSEG_TYPE) {
675 		/* zone is in user, try another */
676 		if (go_left)
677 			hint = zoneno * sbi->secs_per_zone - 1;
678 		else if (zoneno + 1 >= total_zones)
679 			hint = 0;
680 		else
681 			hint = (zoneno + 1) * sbi->secs_per_zone;
682 		init = false;
683 		goto find_other_zone;
684 	}
685 got_it:
686 	/* set it as dirty segment in free segmap */
687 	f2fs_bug_on(test_bit(segno, free_i->free_segmap));
688 	__set_inuse(sbi, segno);
689 	*newseg = segno;
690 	write_unlock(&free_i->segmap_lock);
691 }
692 
693 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
694 {
695 	struct curseg_info *curseg = CURSEG_I(sbi, type);
696 	struct summary_footer *sum_footer;
697 
698 	curseg->segno = curseg->next_segno;
699 	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
700 	curseg->next_blkoff = 0;
701 	curseg->next_segno = NULL_SEGNO;
702 
703 	sum_footer = &(curseg->sum_blk->footer);
704 	memset(sum_footer, 0, sizeof(struct summary_footer));
705 	if (IS_DATASEG(type))
706 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
707 	if (IS_NODESEG(type))
708 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
709 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
710 }
711 
712 /*
713  * Allocate a current working segment.
714  * This function always allocates a free segment in LFS manner.
715  */
716 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
717 {
718 	struct curseg_info *curseg = CURSEG_I(sbi, type);
719 	unsigned int segno = curseg->segno;
720 	int dir = ALLOC_LEFT;
721 
722 	write_sum_page(sbi, curseg->sum_blk,
723 				GET_SUM_BLOCK(sbi, segno));
724 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
725 		dir = ALLOC_RIGHT;
726 
727 	if (test_opt(sbi, NOHEAP))
728 		dir = ALLOC_RIGHT;
729 
730 	get_new_segment(sbi, &segno, new_sec, dir);
731 	curseg->next_segno = segno;
732 	reset_curseg(sbi, type, 1);
733 	curseg->alloc_type = LFS;
734 }
735 
736 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
737 			struct curseg_info *seg, block_t start)
738 {
739 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
740 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
741 	unsigned long target_map[entries];
742 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
743 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
744 	int i, pos;
745 
746 	for (i = 0; i < entries; i++)
747 		target_map[i] = ckpt_map[i] | cur_map[i];
748 
749 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
750 
751 	seg->next_blkoff = pos;
752 }
753 
754 /*
755  * If a segment is written by LFS manner, next block offset is just obtained
756  * by increasing the current block offset. However, if a segment is written by
757  * SSR manner, next block offset obtained by calling __next_free_blkoff
758  */
759 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
760 				struct curseg_info *seg)
761 {
762 	if (seg->alloc_type == SSR)
763 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
764 	else
765 		seg->next_blkoff++;
766 }
767 
768 /*
769  * This function always allocates a used segment (from dirty seglist) by SSR
770  * manner, so it should recover the existing segment information of valid blocks
771  */
772 static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
773 {
774 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
775 	struct curseg_info *curseg = CURSEG_I(sbi, type);
776 	unsigned int new_segno = curseg->next_segno;
777 	struct f2fs_summary_block *sum_node;
778 	struct page *sum_page;
779 
780 	write_sum_page(sbi, curseg->sum_blk,
781 				GET_SUM_BLOCK(sbi, curseg->segno));
782 	__set_test_and_inuse(sbi, new_segno);
783 
784 	mutex_lock(&dirty_i->seglist_lock);
785 	__remove_dirty_segment(sbi, new_segno, PRE);
786 	__remove_dirty_segment(sbi, new_segno, DIRTY);
787 	mutex_unlock(&dirty_i->seglist_lock);
788 
789 	reset_curseg(sbi, type, 1);
790 	curseg->alloc_type = SSR;
791 	__next_free_blkoff(sbi, curseg, 0);
792 
793 	if (reuse) {
794 		sum_page = get_sum_page(sbi, new_segno);
795 		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
796 		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
797 		f2fs_put_page(sum_page, 1);
798 	}
799 }
800 
801 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
802 {
803 	struct curseg_info *curseg = CURSEG_I(sbi, type);
804 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
805 
806 	if (IS_NODESEG(type) || !has_not_enough_free_secs(sbi, 0))
807 		return v_ops->get_victim(sbi,
808 				&(curseg)->next_segno, BG_GC, type, SSR);
809 
810 	/* For data segments, let's do SSR more intensively */
811 	for (; type >= CURSEG_HOT_DATA; type--)
812 		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
813 						BG_GC, type, SSR))
814 			return 1;
815 	return 0;
816 }
817 
818 /*
819  * flush out current segment and replace it with new segment
820  * This function should be returned with success, otherwise BUG
821  */
822 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
823 						int type, bool force)
824 {
825 	struct curseg_info *curseg = CURSEG_I(sbi, type);
826 
827 	if (force)
828 		new_curseg(sbi, type, true);
829 	else if (type == CURSEG_WARM_NODE)
830 		new_curseg(sbi, type, false);
831 	else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
832 		new_curseg(sbi, type, false);
833 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
834 		change_curseg(sbi, type, true);
835 	else
836 		new_curseg(sbi, type, false);
837 
838 	stat_inc_seg_type(sbi, curseg);
839 }
840 
841 void allocate_new_segments(struct f2fs_sb_info *sbi)
842 {
843 	struct curseg_info *curseg;
844 	unsigned int old_curseg;
845 	int i;
846 
847 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
848 		curseg = CURSEG_I(sbi, i);
849 		old_curseg = curseg->segno;
850 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
851 		locate_dirty_segment(sbi, old_curseg);
852 	}
853 }
854 
855 static const struct segment_allocation default_salloc_ops = {
856 	.allocate_segment = allocate_segment_by_default,
857 };
858 
859 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
860 {
861 	struct curseg_info *curseg = CURSEG_I(sbi, type);
862 	if (curseg->next_blkoff < sbi->blocks_per_seg)
863 		return true;
864 	return false;
865 }
866 
867 static int __get_segment_type_2(struct page *page, enum page_type p_type)
868 {
869 	if (p_type == DATA)
870 		return CURSEG_HOT_DATA;
871 	else
872 		return CURSEG_HOT_NODE;
873 }
874 
875 static int __get_segment_type_4(struct page *page, enum page_type p_type)
876 {
877 	if (p_type == DATA) {
878 		struct inode *inode = page->mapping->host;
879 
880 		if (S_ISDIR(inode->i_mode))
881 			return CURSEG_HOT_DATA;
882 		else
883 			return CURSEG_COLD_DATA;
884 	} else {
885 		if (IS_DNODE(page) && !is_cold_node(page))
886 			return CURSEG_HOT_NODE;
887 		else
888 			return CURSEG_COLD_NODE;
889 	}
890 }
891 
892 static int __get_segment_type_6(struct page *page, enum page_type p_type)
893 {
894 	if (p_type == DATA) {
895 		struct inode *inode = page->mapping->host;
896 
897 		if (S_ISDIR(inode->i_mode))
898 			return CURSEG_HOT_DATA;
899 		else if (is_cold_data(page) || file_is_cold(inode))
900 			return CURSEG_COLD_DATA;
901 		else
902 			return CURSEG_WARM_DATA;
903 	} else {
904 		if (IS_DNODE(page))
905 			return is_cold_node(page) ? CURSEG_WARM_NODE :
906 						CURSEG_HOT_NODE;
907 		else
908 			return CURSEG_COLD_NODE;
909 	}
910 }
911 
912 static int __get_segment_type(struct page *page, enum page_type p_type)
913 {
914 	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
915 	switch (sbi->active_logs) {
916 	case 2:
917 		return __get_segment_type_2(page, p_type);
918 	case 4:
919 		return __get_segment_type_4(page, p_type);
920 	}
921 	/* NR_CURSEG_TYPE(6) logs by default */
922 	f2fs_bug_on(sbi->active_logs != NR_CURSEG_TYPE);
923 	return __get_segment_type_6(page, p_type);
924 }
925 
926 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
927 		block_t old_blkaddr, block_t *new_blkaddr,
928 		struct f2fs_summary *sum, int type)
929 {
930 	struct sit_info *sit_i = SIT_I(sbi);
931 	struct curseg_info *curseg;
932 	unsigned int old_cursegno;
933 
934 	curseg = CURSEG_I(sbi, type);
935 
936 	mutex_lock(&curseg->curseg_mutex);
937 
938 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
939 	old_cursegno = curseg->segno;
940 
941 	/*
942 	 * __add_sum_entry should be resided under the curseg_mutex
943 	 * because, this function updates a summary entry in the
944 	 * current summary block.
945 	 */
946 	__add_sum_entry(sbi, type, sum);
947 
948 	mutex_lock(&sit_i->sentry_lock);
949 	__refresh_next_blkoff(sbi, curseg);
950 
951 	stat_inc_block_count(sbi, curseg);
952 
953 	if (!__has_curseg_space(sbi, type))
954 		sit_i->s_ops->allocate_segment(sbi, type, false);
955 	/*
956 	 * SIT information should be updated before segment allocation,
957 	 * since SSR needs latest valid block information.
958 	 */
959 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
960 	locate_dirty_segment(sbi, old_cursegno);
961 
962 	mutex_unlock(&sit_i->sentry_lock);
963 
964 	if (page && IS_NODESEG(type))
965 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
966 
967 	mutex_unlock(&curseg->curseg_mutex);
968 }
969 
970 static void do_write_page(struct f2fs_sb_info *sbi, struct page *page,
971 			block_t old_blkaddr, block_t *new_blkaddr,
972 			struct f2fs_summary *sum, struct f2fs_io_info *fio)
973 {
974 	int type = __get_segment_type(page, fio->type);
975 
976 	allocate_data_block(sbi, page, old_blkaddr, new_blkaddr, sum, type);
977 
978 	/* writeout dirty page into bdev */
979 	f2fs_submit_page_mbio(sbi, page, *new_blkaddr, fio);
980 }
981 
982 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
983 {
984 	struct f2fs_io_info fio = {
985 		.type = META,
986 		.rw = WRITE_SYNC | REQ_META | REQ_PRIO
987 	};
988 
989 	set_page_writeback(page);
990 	f2fs_submit_page_mbio(sbi, page, page->index, &fio);
991 }
992 
993 void write_node_page(struct f2fs_sb_info *sbi, struct page *page,
994 		struct f2fs_io_info *fio,
995 		unsigned int nid, block_t old_blkaddr, block_t *new_blkaddr)
996 {
997 	struct f2fs_summary sum;
998 	set_summary(&sum, nid, 0, 0);
999 	do_write_page(sbi, page, old_blkaddr, new_blkaddr, &sum, fio);
1000 }
1001 
1002 void write_data_page(struct page *page, struct dnode_of_data *dn,
1003 		block_t *new_blkaddr, struct f2fs_io_info *fio)
1004 {
1005 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
1006 	struct f2fs_summary sum;
1007 	struct node_info ni;
1008 
1009 	f2fs_bug_on(dn->data_blkaddr == NULL_ADDR);
1010 	get_node_info(sbi, dn->nid, &ni);
1011 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
1012 
1013 	do_write_page(sbi, page, dn->data_blkaddr, new_blkaddr, &sum, fio);
1014 }
1015 
1016 void rewrite_data_page(struct page *page, block_t old_blkaddr,
1017 					struct f2fs_io_info *fio)
1018 {
1019 	struct inode *inode = page->mapping->host;
1020 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1021 	f2fs_submit_page_mbio(sbi, page, old_blkaddr, fio);
1022 }
1023 
1024 void recover_data_page(struct f2fs_sb_info *sbi,
1025 			struct page *page, struct f2fs_summary *sum,
1026 			block_t old_blkaddr, block_t new_blkaddr)
1027 {
1028 	struct sit_info *sit_i = SIT_I(sbi);
1029 	struct curseg_info *curseg;
1030 	unsigned int segno, old_cursegno;
1031 	struct seg_entry *se;
1032 	int type;
1033 
1034 	segno = GET_SEGNO(sbi, new_blkaddr);
1035 	se = get_seg_entry(sbi, segno);
1036 	type = se->type;
1037 
1038 	if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
1039 		if (old_blkaddr == NULL_ADDR)
1040 			type = CURSEG_COLD_DATA;
1041 		else
1042 			type = CURSEG_WARM_DATA;
1043 	}
1044 	curseg = CURSEG_I(sbi, type);
1045 
1046 	mutex_lock(&curseg->curseg_mutex);
1047 	mutex_lock(&sit_i->sentry_lock);
1048 
1049 	old_cursegno = curseg->segno;
1050 
1051 	/* change the current segment */
1052 	if (segno != curseg->segno) {
1053 		curseg->next_segno = segno;
1054 		change_curseg(sbi, type, true);
1055 	}
1056 
1057 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
1058 	__add_sum_entry(sbi, type, sum);
1059 
1060 	refresh_sit_entry(sbi, old_blkaddr, new_blkaddr);
1061 	locate_dirty_segment(sbi, old_cursegno);
1062 
1063 	mutex_unlock(&sit_i->sentry_lock);
1064 	mutex_unlock(&curseg->curseg_mutex);
1065 }
1066 
1067 void rewrite_node_page(struct f2fs_sb_info *sbi,
1068 			struct page *page, struct f2fs_summary *sum,
1069 			block_t old_blkaddr, block_t new_blkaddr)
1070 {
1071 	struct sit_info *sit_i = SIT_I(sbi);
1072 	int type = CURSEG_WARM_NODE;
1073 	struct curseg_info *curseg;
1074 	unsigned int segno, old_cursegno;
1075 	block_t next_blkaddr = next_blkaddr_of_node(page);
1076 	unsigned int next_segno = GET_SEGNO(sbi, next_blkaddr);
1077 	struct f2fs_io_info fio = {
1078 		.type = NODE,
1079 		.rw = WRITE_SYNC,
1080 	};
1081 
1082 	curseg = CURSEG_I(sbi, type);
1083 
1084 	mutex_lock(&curseg->curseg_mutex);
1085 	mutex_lock(&sit_i->sentry_lock);
1086 
1087 	segno = GET_SEGNO(sbi, new_blkaddr);
1088 	old_cursegno = curseg->segno;
1089 
1090 	/* change the current segment */
1091 	if (segno != curseg->segno) {
1092 		curseg->next_segno = segno;
1093 		change_curseg(sbi, type, true);
1094 	}
1095 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
1096 	__add_sum_entry(sbi, type, sum);
1097 
1098 	/* change the current log to the next block addr in advance */
1099 	if (next_segno != segno) {
1100 		curseg->next_segno = next_segno;
1101 		change_curseg(sbi, type, true);
1102 	}
1103 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, next_blkaddr);
1104 
1105 	/* rewrite node page */
1106 	set_page_writeback(page);
1107 	f2fs_submit_page_mbio(sbi, page, new_blkaddr, &fio);
1108 	f2fs_submit_merged_bio(sbi, NODE, WRITE);
1109 	refresh_sit_entry(sbi, old_blkaddr, new_blkaddr);
1110 	locate_dirty_segment(sbi, old_cursegno);
1111 
1112 	mutex_unlock(&sit_i->sentry_lock);
1113 	mutex_unlock(&curseg->curseg_mutex);
1114 }
1115 
1116 static inline bool is_merged_page(struct f2fs_sb_info *sbi,
1117 					struct page *page, enum page_type type)
1118 {
1119 	enum page_type btype = PAGE_TYPE_OF_BIO(type);
1120 	struct f2fs_bio_info *io = &sbi->write_io[btype];
1121 	struct bio_vec *bvec;
1122 	int i;
1123 
1124 	down_read(&io->io_rwsem);
1125 	if (!io->bio)
1126 		goto out;
1127 
1128 	bio_for_each_segment_all(bvec, io->bio, i) {
1129 		if (page == bvec->bv_page) {
1130 			up_read(&io->io_rwsem);
1131 			return true;
1132 		}
1133 	}
1134 
1135 out:
1136 	up_read(&io->io_rwsem);
1137 	return false;
1138 }
1139 
1140 void f2fs_wait_on_page_writeback(struct page *page,
1141 				enum page_type type)
1142 {
1143 	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
1144 	if (PageWriteback(page)) {
1145 		if (is_merged_page(sbi, page, type))
1146 			f2fs_submit_merged_bio(sbi, type, WRITE);
1147 		wait_on_page_writeback(page);
1148 	}
1149 }
1150 
1151 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
1152 {
1153 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1154 	struct curseg_info *seg_i;
1155 	unsigned char *kaddr;
1156 	struct page *page;
1157 	block_t start;
1158 	int i, j, offset;
1159 
1160 	start = start_sum_block(sbi);
1161 
1162 	page = get_meta_page(sbi, start++);
1163 	kaddr = (unsigned char *)page_address(page);
1164 
1165 	/* Step 1: restore nat cache */
1166 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
1167 	memcpy(&seg_i->sum_blk->n_nats, kaddr, SUM_JOURNAL_SIZE);
1168 
1169 	/* Step 2: restore sit cache */
1170 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
1171 	memcpy(&seg_i->sum_blk->n_sits, kaddr + SUM_JOURNAL_SIZE,
1172 						SUM_JOURNAL_SIZE);
1173 	offset = 2 * SUM_JOURNAL_SIZE;
1174 
1175 	/* Step 3: restore summary entries */
1176 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1177 		unsigned short blk_off;
1178 		unsigned int segno;
1179 
1180 		seg_i = CURSEG_I(sbi, i);
1181 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
1182 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
1183 		seg_i->next_segno = segno;
1184 		reset_curseg(sbi, i, 0);
1185 		seg_i->alloc_type = ckpt->alloc_type[i];
1186 		seg_i->next_blkoff = blk_off;
1187 
1188 		if (seg_i->alloc_type == SSR)
1189 			blk_off = sbi->blocks_per_seg;
1190 
1191 		for (j = 0; j < blk_off; j++) {
1192 			struct f2fs_summary *s;
1193 			s = (struct f2fs_summary *)(kaddr + offset);
1194 			seg_i->sum_blk->entries[j] = *s;
1195 			offset += SUMMARY_SIZE;
1196 			if (offset + SUMMARY_SIZE <= PAGE_CACHE_SIZE -
1197 						SUM_FOOTER_SIZE)
1198 				continue;
1199 
1200 			f2fs_put_page(page, 1);
1201 			page = NULL;
1202 
1203 			page = get_meta_page(sbi, start++);
1204 			kaddr = (unsigned char *)page_address(page);
1205 			offset = 0;
1206 		}
1207 	}
1208 	f2fs_put_page(page, 1);
1209 	return 0;
1210 }
1211 
1212 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
1213 {
1214 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1215 	struct f2fs_summary_block *sum;
1216 	struct curseg_info *curseg;
1217 	struct page *new;
1218 	unsigned short blk_off;
1219 	unsigned int segno = 0;
1220 	block_t blk_addr = 0;
1221 
1222 	/* get segment number and block addr */
1223 	if (IS_DATASEG(type)) {
1224 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
1225 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
1226 							CURSEG_HOT_DATA]);
1227 		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG))
1228 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
1229 		else
1230 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
1231 	} else {
1232 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
1233 							CURSEG_HOT_NODE]);
1234 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
1235 							CURSEG_HOT_NODE]);
1236 		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG))
1237 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
1238 							type - CURSEG_HOT_NODE);
1239 		else
1240 			blk_addr = GET_SUM_BLOCK(sbi, segno);
1241 	}
1242 
1243 	new = get_meta_page(sbi, blk_addr);
1244 	sum = (struct f2fs_summary_block *)page_address(new);
1245 
1246 	if (IS_NODESEG(type)) {
1247 		if (is_set_ckpt_flags(ckpt, CP_UMOUNT_FLAG)) {
1248 			struct f2fs_summary *ns = &sum->entries[0];
1249 			int i;
1250 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
1251 				ns->version = 0;
1252 				ns->ofs_in_node = 0;
1253 			}
1254 		} else {
1255 			int err;
1256 
1257 			err = restore_node_summary(sbi, segno, sum);
1258 			if (err) {
1259 				f2fs_put_page(new, 1);
1260 				return err;
1261 			}
1262 		}
1263 	}
1264 
1265 	/* set uncompleted segment to curseg */
1266 	curseg = CURSEG_I(sbi, type);
1267 	mutex_lock(&curseg->curseg_mutex);
1268 	memcpy(curseg->sum_blk, sum, PAGE_CACHE_SIZE);
1269 	curseg->next_segno = segno;
1270 	reset_curseg(sbi, type, 0);
1271 	curseg->alloc_type = ckpt->alloc_type[type];
1272 	curseg->next_blkoff = blk_off;
1273 	mutex_unlock(&curseg->curseg_mutex);
1274 	f2fs_put_page(new, 1);
1275 	return 0;
1276 }
1277 
1278 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
1279 {
1280 	int type = CURSEG_HOT_DATA;
1281 	int err;
1282 
1283 	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG)) {
1284 		/* restore for compacted data summary */
1285 		if (read_compacted_summaries(sbi))
1286 			return -EINVAL;
1287 		type = CURSEG_HOT_NODE;
1288 	}
1289 
1290 	for (; type <= CURSEG_COLD_NODE; type++) {
1291 		err = read_normal_summaries(sbi, type);
1292 		if (err)
1293 			return err;
1294 	}
1295 
1296 	return 0;
1297 }
1298 
1299 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
1300 {
1301 	struct page *page;
1302 	unsigned char *kaddr;
1303 	struct f2fs_summary *summary;
1304 	struct curseg_info *seg_i;
1305 	int written_size = 0;
1306 	int i, j;
1307 
1308 	page = grab_meta_page(sbi, blkaddr++);
1309 	kaddr = (unsigned char *)page_address(page);
1310 
1311 	/* Step 1: write nat cache */
1312 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
1313 	memcpy(kaddr, &seg_i->sum_blk->n_nats, SUM_JOURNAL_SIZE);
1314 	written_size += SUM_JOURNAL_SIZE;
1315 
1316 	/* Step 2: write sit cache */
1317 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
1318 	memcpy(kaddr + written_size, &seg_i->sum_blk->n_sits,
1319 						SUM_JOURNAL_SIZE);
1320 	written_size += SUM_JOURNAL_SIZE;
1321 
1322 	/* Step 3: write summary entries */
1323 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1324 		unsigned short blkoff;
1325 		seg_i = CURSEG_I(sbi, i);
1326 		if (sbi->ckpt->alloc_type[i] == SSR)
1327 			blkoff = sbi->blocks_per_seg;
1328 		else
1329 			blkoff = curseg_blkoff(sbi, i);
1330 
1331 		for (j = 0; j < blkoff; j++) {
1332 			if (!page) {
1333 				page = grab_meta_page(sbi, blkaddr++);
1334 				kaddr = (unsigned char *)page_address(page);
1335 				written_size = 0;
1336 			}
1337 			summary = (struct f2fs_summary *)(kaddr + written_size);
1338 			*summary = seg_i->sum_blk->entries[j];
1339 			written_size += SUMMARY_SIZE;
1340 
1341 			if (written_size + SUMMARY_SIZE <= PAGE_CACHE_SIZE -
1342 							SUM_FOOTER_SIZE)
1343 				continue;
1344 
1345 			set_page_dirty(page);
1346 			f2fs_put_page(page, 1);
1347 			page = NULL;
1348 		}
1349 	}
1350 	if (page) {
1351 		set_page_dirty(page);
1352 		f2fs_put_page(page, 1);
1353 	}
1354 }
1355 
1356 static void write_normal_summaries(struct f2fs_sb_info *sbi,
1357 					block_t blkaddr, int type)
1358 {
1359 	int i, end;
1360 	if (IS_DATASEG(type))
1361 		end = type + NR_CURSEG_DATA_TYPE;
1362 	else
1363 		end = type + NR_CURSEG_NODE_TYPE;
1364 
1365 	for (i = type; i < end; i++) {
1366 		struct curseg_info *sum = CURSEG_I(sbi, i);
1367 		mutex_lock(&sum->curseg_mutex);
1368 		write_sum_page(sbi, sum->sum_blk, blkaddr + (i - type));
1369 		mutex_unlock(&sum->curseg_mutex);
1370 	}
1371 }
1372 
1373 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
1374 {
1375 	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_COMPACT_SUM_FLAG))
1376 		write_compacted_summaries(sbi, start_blk);
1377 	else
1378 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
1379 }
1380 
1381 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
1382 {
1383 	if (is_set_ckpt_flags(F2FS_CKPT(sbi), CP_UMOUNT_FLAG))
1384 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
1385 }
1386 
1387 int lookup_journal_in_cursum(struct f2fs_summary_block *sum, int type,
1388 					unsigned int val, int alloc)
1389 {
1390 	int i;
1391 
1392 	if (type == NAT_JOURNAL) {
1393 		for (i = 0; i < nats_in_cursum(sum); i++) {
1394 			if (le32_to_cpu(nid_in_journal(sum, i)) == val)
1395 				return i;
1396 		}
1397 		if (alloc && nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES)
1398 			return update_nats_in_cursum(sum, 1);
1399 	} else if (type == SIT_JOURNAL) {
1400 		for (i = 0; i < sits_in_cursum(sum); i++)
1401 			if (le32_to_cpu(segno_in_journal(sum, i)) == val)
1402 				return i;
1403 		if (alloc && sits_in_cursum(sum) < SIT_JOURNAL_ENTRIES)
1404 			return update_sits_in_cursum(sum, 1);
1405 	}
1406 	return -1;
1407 }
1408 
1409 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
1410 					unsigned int segno)
1411 {
1412 	struct sit_info *sit_i = SIT_I(sbi);
1413 	unsigned int offset = SIT_BLOCK_OFFSET(sit_i, segno);
1414 	block_t blk_addr = sit_i->sit_base_addr + offset;
1415 
1416 	check_seg_range(sbi, segno);
1417 
1418 	/* calculate sit block address */
1419 	if (f2fs_test_bit(offset, sit_i->sit_bitmap))
1420 		blk_addr += sit_i->sit_blocks;
1421 
1422 	return get_meta_page(sbi, blk_addr);
1423 }
1424 
1425 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
1426 					unsigned int start)
1427 {
1428 	struct sit_info *sit_i = SIT_I(sbi);
1429 	struct page *src_page, *dst_page;
1430 	pgoff_t src_off, dst_off;
1431 	void *src_addr, *dst_addr;
1432 
1433 	src_off = current_sit_addr(sbi, start);
1434 	dst_off = next_sit_addr(sbi, src_off);
1435 
1436 	/* get current sit block page without lock */
1437 	src_page = get_meta_page(sbi, src_off);
1438 	dst_page = grab_meta_page(sbi, dst_off);
1439 	f2fs_bug_on(PageDirty(src_page));
1440 
1441 	src_addr = page_address(src_page);
1442 	dst_addr = page_address(dst_page);
1443 	memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
1444 
1445 	set_page_dirty(dst_page);
1446 	f2fs_put_page(src_page, 1);
1447 
1448 	set_to_next_sit(sit_i, start);
1449 
1450 	return dst_page;
1451 }
1452 
1453 static bool flush_sits_in_journal(struct f2fs_sb_info *sbi)
1454 {
1455 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
1456 	struct f2fs_summary_block *sum = curseg->sum_blk;
1457 	int i;
1458 
1459 	/*
1460 	 * If the journal area in the current summary is full of sit entries,
1461 	 * all the sit entries will be flushed. Otherwise the sit entries
1462 	 * are not able to replace with newly hot sit entries.
1463 	 */
1464 	if (sits_in_cursum(sum) >= SIT_JOURNAL_ENTRIES) {
1465 		for (i = sits_in_cursum(sum) - 1; i >= 0; i--) {
1466 			unsigned int segno;
1467 			segno = le32_to_cpu(segno_in_journal(sum, i));
1468 			__mark_sit_entry_dirty(sbi, segno);
1469 		}
1470 		update_sits_in_cursum(sum, -sits_in_cursum(sum));
1471 		return true;
1472 	}
1473 	return false;
1474 }
1475 
1476 /*
1477  * CP calls this function, which flushes SIT entries including sit_journal,
1478  * and moves prefree segs to free segs.
1479  */
1480 void flush_sit_entries(struct f2fs_sb_info *sbi)
1481 {
1482 	struct sit_info *sit_i = SIT_I(sbi);
1483 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
1484 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
1485 	struct f2fs_summary_block *sum = curseg->sum_blk;
1486 	unsigned long nsegs = TOTAL_SEGS(sbi);
1487 	struct page *page = NULL;
1488 	struct f2fs_sit_block *raw_sit = NULL;
1489 	unsigned int start = 0, end = 0;
1490 	unsigned int segno = -1;
1491 	bool flushed;
1492 
1493 	mutex_lock(&curseg->curseg_mutex);
1494 	mutex_lock(&sit_i->sentry_lock);
1495 
1496 	/*
1497 	 * "flushed" indicates whether sit entries in journal are flushed
1498 	 * to the SIT area or not.
1499 	 */
1500 	flushed = flush_sits_in_journal(sbi);
1501 
1502 	while ((segno = find_next_bit(bitmap, nsegs, segno + 1)) < nsegs) {
1503 		struct seg_entry *se = get_seg_entry(sbi, segno);
1504 		int sit_offset, offset;
1505 
1506 		sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
1507 
1508 		/* add discard candidates */
1509 		if (SM_I(sbi)->nr_discards < SM_I(sbi)->max_discards)
1510 			add_discard_addrs(sbi, segno, se);
1511 
1512 		if (flushed)
1513 			goto to_sit_page;
1514 
1515 		offset = lookup_journal_in_cursum(sum, SIT_JOURNAL, segno, 1);
1516 		if (offset >= 0) {
1517 			segno_in_journal(sum, offset) = cpu_to_le32(segno);
1518 			seg_info_to_raw_sit(se, &sit_in_journal(sum, offset));
1519 			goto flush_done;
1520 		}
1521 to_sit_page:
1522 		if (!page || (start > segno) || (segno > end)) {
1523 			if (page) {
1524 				f2fs_put_page(page, 1);
1525 				page = NULL;
1526 			}
1527 
1528 			start = START_SEGNO(sit_i, segno);
1529 			end = start + SIT_ENTRY_PER_BLOCK - 1;
1530 
1531 			/* read sit block that will be updated */
1532 			page = get_next_sit_page(sbi, start);
1533 			raw_sit = page_address(page);
1534 		}
1535 
1536 		/* udpate entry in SIT block */
1537 		seg_info_to_raw_sit(se, &raw_sit->entries[sit_offset]);
1538 flush_done:
1539 		__clear_bit(segno, bitmap);
1540 		sit_i->dirty_sentries--;
1541 	}
1542 	mutex_unlock(&sit_i->sentry_lock);
1543 	mutex_unlock(&curseg->curseg_mutex);
1544 
1545 	/* writeout last modified SIT block */
1546 	f2fs_put_page(page, 1);
1547 
1548 	set_prefree_as_free_segments(sbi);
1549 }
1550 
1551 static int build_sit_info(struct f2fs_sb_info *sbi)
1552 {
1553 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
1554 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1555 	struct sit_info *sit_i;
1556 	unsigned int sit_segs, start;
1557 	char *src_bitmap, *dst_bitmap;
1558 	unsigned int bitmap_size;
1559 
1560 	/* allocate memory for SIT information */
1561 	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
1562 	if (!sit_i)
1563 		return -ENOMEM;
1564 
1565 	SM_I(sbi)->sit_info = sit_i;
1566 
1567 	sit_i->sentries = vzalloc(TOTAL_SEGS(sbi) * sizeof(struct seg_entry));
1568 	if (!sit_i->sentries)
1569 		return -ENOMEM;
1570 
1571 	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
1572 	sit_i->dirty_sentries_bitmap = kzalloc(bitmap_size, GFP_KERNEL);
1573 	if (!sit_i->dirty_sentries_bitmap)
1574 		return -ENOMEM;
1575 
1576 	for (start = 0; start < TOTAL_SEGS(sbi); start++) {
1577 		sit_i->sentries[start].cur_valid_map
1578 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
1579 		sit_i->sentries[start].ckpt_valid_map
1580 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
1581 		if (!sit_i->sentries[start].cur_valid_map
1582 				|| !sit_i->sentries[start].ckpt_valid_map)
1583 			return -ENOMEM;
1584 	}
1585 
1586 	if (sbi->segs_per_sec > 1) {
1587 		sit_i->sec_entries = vzalloc(TOTAL_SECS(sbi) *
1588 					sizeof(struct sec_entry));
1589 		if (!sit_i->sec_entries)
1590 			return -ENOMEM;
1591 	}
1592 
1593 	/* get information related with SIT */
1594 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
1595 
1596 	/* setup SIT bitmap from ckeckpoint pack */
1597 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
1598 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
1599 
1600 	dst_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
1601 	if (!dst_bitmap)
1602 		return -ENOMEM;
1603 
1604 	/* init SIT information */
1605 	sit_i->s_ops = &default_salloc_ops;
1606 
1607 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
1608 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
1609 	sit_i->written_valid_blocks = le64_to_cpu(ckpt->valid_block_count);
1610 	sit_i->sit_bitmap = dst_bitmap;
1611 	sit_i->bitmap_size = bitmap_size;
1612 	sit_i->dirty_sentries = 0;
1613 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
1614 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
1615 	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
1616 	mutex_init(&sit_i->sentry_lock);
1617 	return 0;
1618 }
1619 
1620 static int build_free_segmap(struct f2fs_sb_info *sbi)
1621 {
1622 	struct f2fs_sm_info *sm_info = SM_I(sbi);
1623 	struct free_segmap_info *free_i;
1624 	unsigned int bitmap_size, sec_bitmap_size;
1625 
1626 	/* allocate memory for free segmap information */
1627 	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
1628 	if (!free_i)
1629 		return -ENOMEM;
1630 
1631 	SM_I(sbi)->free_info = free_i;
1632 
1633 	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
1634 	free_i->free_segmap = kmalloc(bitmap_size, GFP_KERNEL);
1635 	if (!free_i->free_segmap)
1636 		return -ENOMEM;
1637 
1638 	sec_bitmap_size = f2fs_bitmap_size(TOTAL_SECS(sbi));
1639 	free_i->free_secmap = kmalloc(sec_bitmap_size, GFP_KERNEL);
1640 	if (!free_i->free_secmap)
1641 		return -ENOMEM;
1642 
1643 	/* set all segments as dirty temporarily */
1644 	memset(free_i->free_segmap, 0xff, bitmap_size);
1645 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
1646 
1647 	/* init free segmap information */
1648 	free_i->start_segno =
1649 		(unsigned int) GET_SEGNO_FROM_SEG0(sbi, sm_info->main_blkaddr);
1650 	free_i->free_segments = 0;
1651 	free_i->free_sections = 0;
1652 	rwlock_init(&free_i->segmap_lock);
1653 	return 0;
1654 }
1655 
1656 static int build_curseg(struct f2fs_sb_info *sbi)
1657 {
1658 	struct curseg_info *array;
1659 	int i;
1660 
1661 	array = kzalloc(sizeof(*array) * NR_CURSEG_TYPE, GFP_KERNEL);
1662 	if (!array)
1663 		return -ENOMEM;
1664 
1665 	SM_I(sbi)->curseg_array = array;
1666 
1667 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
1668 		mutex_init(&array[i].curseg_mutex);
1669 		array[i].sum_blk = kzalloc(PAGE_CACHE_SIZE, GFP_KERNEL);
1670 		if (!array[i].sum_blk)
1671 			return -ENOMEM;
1672 		array[i].segno = NULL_SEGNO;
1673 		array[i].next_blkoff = 0;
1674 	}
1675 	return restore_curseg_summaries(sbi);
1676 }
1677 
1678 static void build_sit_entries(struct f2fs_sb_info *sbi)
1679 {
1680 	struct sit_info *sit_i = SIT_I(sbi);
1681 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
1682 	struct f2fs_summary_block *sum = curseg->sum_blk;
1683 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
1684 	unsigned int i, start, end;
1685 	unsigned int readed, start_blk = 0;
1686 	int nrpages = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
1687 
1688 	do {
1689 		readed = ra_meta_pages(sbi, start_blk, nrpages, META_SIT);
1690 
1691 		start = start_blk * sit_i->sents_per_block;
1692 		end = (start_blk + readed) * sit_i->sents_per_block;
1693 
1694 		for (; start < end && start < TOTAL_SEGS(sbi); start++) {
1695 			struct seg_entry *se = &sit_i->sentries[start];
1696 			struct f2fs_sit_block *sit_blk;
1697 			struct f2fs_sit_entry sit;
1698 			struct page *page;
1699 
1700 			mutex_lock(&curseg->curseg_mutex);
1701 			for (i = 0; i < sits_in_cursum(sum); i++) {
1702 				if (le32_to_cpu(segno_in_journal(sum, i))
1703 								== start) {
1704 					sit = sit_in_journal(sum, i);
1705 					mutex_unlock(&curseg->curseg_mutex);
1706 					goto got_it;
1707 				}
1708 			}
1709 			mutex_unlock(&curseg->curseg_mutex);
1710 
1711 			page = get_current_sit_page(sbi, start);
1712 			sit_blk = (struct f2fs_sit_block *)page_address(page);
1713 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
1714 			f2fs_put_page(page, 1);
1715 got_it:
1716 			check_block_count(sbi, start, &sit);
1717 			seg_info_from_raw_sit(se, &sit);
1718 			if (sbi->segs_per_sec > 1) {
1719 				struct sec_entry *e = get_sec_entry(sbi, start);
1720 				e->valid_blocks += se->valid_blocks;
1721 			}
1722 		}
1723 		start_blk += readed;
1724 	} while (start_blk < sit_blk_cnt);
1725 }
1726 
1727 static void init_free_segmap(struct f2fs_sb_info *sbi)
1728 {
1729 	unsigned int start;
1730 	int type;
1731 
1732 	for (start = 0; start < TOTAL_SEGS(sbi); start++) {
1733 		struct seg_entry *sentry = get_seg_entry(sbi, start);
1734 		if (!sentry->valid_blocks)
1735 			__set_free(sbi, start);
1736 	}
1737 
1738 	/* set use the current segments */
1739 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
1740 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
1741 		__set_test_and_inuse(sbi, curseg_t->segno);
1742 	}
1743 }
1744 
1745 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
1746 {
1747 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1748 	struct free_segmap_info *free_i = FREE_I(sbi);
1749 	unsigned int segno = 0, offset = 0, total_segs = TOTAL_SEGS(sbi);
1750 	unsigned short valid_blocks;
1751 
1752 	while (1) {
1753 		/* find dirty segment based on free segmap */
1754 		segno = find_next_inuse(free_i, total_segs, offset);
1755 		if (segno >= total_segs)
1756 			break;
1757 		offset = segno + 1;
1758 		valid_blocks = get_valid_blocks(sbi, segno, 0);
1759 		if (valid_blocks >= sbi->blocks_per_seg || !valid_blocks)
1760 			continue;
1761 		mutex_lock(&dirty_i->seglist_lock);
1762 		__locate_dirty_segment(sbi, segno, DIRTY);
1763 		mutex_unlock(&dirty_i->seglist_lock);
1764 	}
1765 }
1766 
1767 static int init_victim_secmap(struct f2fs_sb_info *sbi)
1768 {
1769 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1770 	unsigned int bitmap_size = f2fs_bitmap_size(TOTAL_SECS(sbi));
1771 
1772 	dirty_i->victim_secmap = kzalloc(bitmap_size, GFP_KERNEL);
1773 	if (!dirty_i->victim_secmap)
1774 		return -ENOMEM;
1775 	return 0;
1776 }
1777 
1778 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
1779 {
1780 	struct dirty_seglist_info *dirty_i;
1781 	unsigned int bitmap_size, i;
1782 
1783 	/* allocate memory for dirty segments list information */
1784 	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
1785 	if (!dirty_i)
1786 		return -ENOMEM;
1787 
1788 	SM_I(sbi)->dirty_info = dirty_i;
1789 	mutex_init(&dirty_i->seglist_lock);
1790 
1791 	bitmap_size = f2fs_bitmap_size(TOTAL_SEGS(sbi));
1792 
1793 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
1794 		dirty_i->dirty_segmap[i] = kzalloc(bitmap_size, GFP_KERNEL);
1795 		if (!dirty_i->dirty_segmap[i])
1796 			return -ENOMEM;
1797 	}
1798 
1799 	init_dirty_segmap(sbi);
1800 	return init_victim_secmap(sbi);
1801 }
1802 
1803 /*
1804  * Update min, max modified time for cost-benefit GC algorithm
1805  */
1806 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
1807 {
1808 	struct sit_info *sit_i = SIT_I(sbi);
1809 	unsigned int segno;
1810 
1811 	mutex_lock(&sit_i->sentry_lock);
1812 
1813 	sit_i->min_mtime = LLONG_MAX;
1814 
1815 	for (segno = 0; segno < TOTAL_SEGS(sbi); segno += sbi->segs_per_sec) {
1816 		unsigned int i;
1817 		unsigned long long mtime = 0;
1818 
1819 		for (i = 0; i < sbi->segs_per_sec; i++)
1820 			mtime += get_seg_entry(sbi, segno + i)->mtime;
1821 
1822 		mtime = div_u64(mtime, sbi->segs_per_sec);
1823 
1824 		if (sit_i->min_mtime > mtime)
1825 			sit_i->min_mtime = mtime;
1826 	}
1827 	sit_i->max_mtime = get_mtime(sbi);
1828 	mutex_unlock(&sit_i->sentry_lock);
1829 }
1830 
1831 int build_segment_manager(struct f2fs_sb_info *sbi)
1832 {
1833 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
1834 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1835 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1836 	struct f2fs_sm_info *sm_info;
1837 	int err;
1838 
1839 	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
1840 	if (!sm_info)
1841 		return -ENOMEM;
1842 
1843 	/* init sm info */
1844 	sbi->sm_info = sm_info;
1845 	INIT_LIST_HEAD(&sm_info->wblist_head);
1846 	spin_lock_init(&sm_info->wblist_lock);
1847 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
1848 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
1849 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
1850 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
1851 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
1852 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
1853 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
1854 	sm_info->rec_prefree_segments = sm_info->main_segments *
1855 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
1856 	sm_info->ipu_policy = F2FS_IPU_DISABLE;
1857 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
1858 
1859 	INIT_LIST_HEAD(&sm_info->discard_list);
1860 	sm_info->nr_discards = 0;
1861 	sm_info->max_discards = 0;
1862 
1863 	if (test_opt(sbi, FLUSH_MERGE)) {
1864 		spin_lock_init(&sm_info->issue_lock);
1865 		init_waitqueue_head(&sm_info->flush_wait_queue);
1866 
1867 		sm_info->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
1868 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
1869 		if (IS_ERR(sm_info->f2fs_issue_flush))
1870 			return PTR_ERR(sm_info->f2fs_issue_flush);
1871 	}
1872 
1873 	err = build_sit_info(sbi);
1874 	if (err)
1875 		return err;
1876 	err = build_free_segmap(sbi);
1877 	if (err)
1878 		return err;
1879 	err = build_curseg(sbi);
1880 	if (err)
1881 		return err;
1882 
1883 	/* reinit free segmap based on SIT */
1884 	build_sit_entries(sbi);
1885 
1886 	init_free_segmap(sbi);
1887 	err = build_dirty_segmap(sbi);
1888 	if (err)
1889 		return err;
1890 
1891 	init_min_max_mtime(sbi);
1892 	return 0;
1893 }
1894 
1895 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
1896 		enum dirty_type dirty_type)
1897 {
1898 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1899 
1900 	mutex_lock(&dirty_i->seglist_lock);
1901 	kfree(dirty_i->dirty_segmap[dirty_type]);
1902 	dirty_i->nr_dirty[dirty_type] = 0;
1903 	mutex_unlock(&dirty_i->seglist_lock);
1904 }
1905 
1906 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
1907 {
1908 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1909 	kfree(dirty_i->victim_secmap);
1910 }
1911 
1912 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
1913 {
1914 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1915 	int i;
1916 
1917 	if (!dirty_i)
1918 		return;
1919 
1920 	/* discard pre-free/dirty segments list */
1921 	for (i = 0; i < NR_DIRTY_TYPE; i++)
1922 		discard_dirty_segmap(sbi, i);
1923 
1924 	destroy_victim_secmap(sbi);
1925 	SM_I(sbi)->dirty_info = NULL;
1926 	kfree(dirty_i);
1927 }
1928 
1929 static void destroy_curseg(struct f2fs_sb_info *sbi)
1930 {
1931 	struct curseg_info *array = SM_I(sbi)->curseg_array;
1932 	int i;
1933 
1934 	if (!array)
1935 		return;
1936 	SM_I(sbi)->curseg_array = NULL;
1937 	for (i = 0; i < NR_CURSEG_TYPE; i++)
1938 		kfree(array[i].sum_blk);
1939 	kfree(array);
1940 }
1941 
1942 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
1943 {
1944 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
1945 	if (!free_i)
1946 		return;
1947 	SM_I(sbi)->free_info = NULL;
1948 	kfree(free_i->free_segmap);
1949 	kfree(free_i->free_secmap);
1950 	kfree(free_i);
1951 }
1952 
1953 static void destroy_sit_info(struct f2fs_sb_info *sbi)
1954 {
1955 	struct sit_info *sit_i = SIT_I(sbi);
1956 	unsigned int start;
1957 
1958 	if (!sit_i)
1959 		return;
1960 
1961 	if (sit_i->sentries) {
1962 		for (start = 0; start < TOTAL_SEGS(sbi); start++) {
1963 			kfree(sit_i->sentries[start].cur_valid_map);
1964 			kfree(sit_i->sentries[start].ckpt_valid_map);
1965 		}
1966 	}
1967 	vfree(sit_i->sentries);
1968 	vfree(sit_i->sec_entries);
1969 	kfree(sit_i->dirty_sentries_bitmap);
1970 
1971 	SM_I(sbi)->sit_info = NULL;
1972 	kfree(sit_i->sit_bitmap);
1973 	kfree(sit_i);
1974 }
1975 
1976 void destroy_segment_manager(struct f2fs_sb_info *sbi)
1977 {
1978 	struct f2fs_sm_info *sm_info = SM_I(sbi);
1979 	if (!sm_info)
1980 		return;
1981 	if (sm_info->f2fs_issue_flush)
1982 		kthread_stop(sm_info->f2fs_issue_flush);
1983 	destroy_dirty_segmap(sbi);
1984 	destroy_curseg(sbi);
1985 	destroy_free_segmap(sbi);
1986 	destroy_sit_info(sbi);
1987 	sbi->sm_info = NULL;
1988 	kfree(sm_info);
1989 }
1990 
1991 int __init create_segment_manager_caches(void)
1992 {
1993 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
1994 			sizeof(struct discard_entry));
1995 	if (!discard_entry_slab)
1996 		return -ENOMEM;
1997 	flush_cmd_slab = f2fs_kmem_cache_create("flush_command",
1998 			sizeof(struct flush_cmd));
1999 	if (!flush_cmd_slab) {
2000 		kmem_cache_destroy(discard_entry_slab);
2001 		return -ENOMEM;
2002 	}
2003 	return 0;
2004 }
2005 
2006 void destroy_segment_manager_caches(void)
2007 {
2008 	kmem_cache_destroy(discard_entry_slab);
2009 	kmem_cache_destroy(flush_cmd_slab);
2010 }
2011