xref: /openbmc/linux/fs/f2fs/segment.c (revision 46f84c2c058784f42f2d021df79384ec66cdb256)
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/swap.h>
18 #include <linux/timer.h>
19 
20 #include "f2fs.h"
21 #include "segment.h"
22 #include "node.h"
23 #include "trace.h"
24 #include <trace/events/f2fs.h>
25 
26 #define __reverse_ffz(x) __reverse_ffs(~(x))
27 
28 static struct kmem_cache *discard_entry_slab;
29 static struct kmem_cache *discard_cmd_slab;
30 static struct kmem_cache *sit_entry_set_slab;
31 static struct kmem_cache *inmem_entry_slab;
32 
33 static unsigned long __reverse_ulong(unsigned char *str)
34 {
35 	unsigned long tmp = 0;
36 	int shift = 24, idx = 0;
37 
38 #if BITS_PER_LONG == 64
39 	shift = 56;
40 #endif
41 	while (shift >= 0) {
42 		tmp |= (unsigned long)str[idx++] << shift;
43 		shift -= BITS_PER_BYTE;
44 	}
45 	return tmp;
46 }
47 
48 /*
49  * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
50  * MSB and LSB are reversed in a byte by f2fs_set_bit.
51  */
52 static inline unsigned long __reverse_ffs(unsigned long word)
53 {
54 	int num = 0;
55 
56 #if BITS_PER_LONG == 64
57 	if ((word & 0xffffffff00000000UL) == 0)
58 		num += 32;
59 	else
60 		word >>= 32;
61 #endif
62 	if ((word & 0xffff0000) == 0)
63 		num += 16;
64 	else
65 		word >>= 16;
66 
67 	if ((word & 0xff00) == 0)
68 		num += 8;
69 	else
70 		word >>= 8;
71 
72 	if ((word & 0xf0) == 0)
73 		num += 4;
74 	else
75 		word >>= 4;
76 
77 	if ((word & 0xc) == 0)
78 		num += 2;
79 	else
80 		word >>= 2;
81 
82 	if ((word & 0x2) == 0)
83 		num += 1;
84 	return num;
85 }
86 
87 /*
88  * __find_rev_next(_zero)_bit is copied from lib/find_next_bit.c because
89  * f2fs_set_bit makes MSB and LSB reversed in a byte.
90  * @size must be integral times of unsigned long.
91  * Example:
92  *                             MSB <--> LSB
93  *   f2fs_set_bit(0, bitmap) => 1000 0000
94  *   f2fs_set_bit(7, bitmap) => 0000 0001
95  */
96 static unsigned long __find_rev_next_bit(const unsigned long *addr,
97 			unsigned long size, unsigned long offset)
98 {
99 	const unsigned long *p = addr + BIT_WORD(offset);
100 	unsigned long result = size;
101 	unsigned long tmp;
102 
103 	if (offset >= size)
104 		return size;
105 
106 	size -= (offset & ~(BITS_PER_LONG - 1));
107 	offset %= BITS_PER_LONG;
108 
109 	while (1) {
110 		if (*p == 0)
111 			goto pass;
112 
113 		tmp = __reverse_ulong((unsigned char *)p);
114 
115 		tmp &= ~0UL >> offset;
116 		if (size < BITS_PER_LONG)
117 			tmp &= (~0UL << (BITS_PER_LONG - size));
118 		if (tmp)
119 			goto found;
120 pass:
121 		if (size <= BITS_PER_LONG)
122 			break;
123 		size -= BITS_PER_LONG;
124 		offset = 0;
125 		p++;
126 	}
127 	return result;
128 found:
129 	return result - size + __reverse_ffs(tmp);
130 }
131 
132 static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
133 			unsigned long size, unsigned long offset)
134 {
135 	const unsigned long *p = addr + BIT_WORD(offset);
136 	unsigned long result = size;
137 	unsigned long tmp;
138 
139 	if (offset >= size)
140 		return size;
141 
142 	size -= (offset & ~(BITS_PER_LONG - 1));
143 	offset %= BITS_PER_LONG;
144 
145 	while (1) {
146 		if (*p == ~0UL)
147 			goto pass;
148 
149 		tmp = __reverse_ulong((unsigned char *)p);
150 
151 		if (offset)
152 			tmp |= ~0UL << (BITS_PER_LONG - offset);
153 		if (size < BITS_PER_LONG)
154 			tmp |= ~0UL >> size;
155 		if (tmp != ~0UL)
156 			goto found;
157 pass:
158 		if (size <= BITS_PER_LONG)
159 			break;
160 		size -= BITS_PER_LONG;
161 		offset = 0;
162 		p++;
163 	}
164 	return result;
165 found:
166 	return result - size + __reverse_ffz(tmp);
167 }
168 
169 void register_inmem_page(struct inode *inode, struct page *page)
170 {
171 	struct f2fs_inode_info *fi = F2FS_I(inode);
172 	struct inmem_pages *new;
173 
174 	f2fs_trace_pid(page);
175 
176 	set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
177 	SetPagePrivate(page);
178 
179 	new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
180 
181 	/* add atomic page indices to the list */
182 	new->page = page;
183 	INIT_LIST_HEAD(&new->list);
184 
185 	/* increase reference count with clean state */
186 	mutex_lock(&fi->inmem_lock);
187 	get_page(page);
188 	list_add_tail(&new->list, &fi->inmem_pages);
189 	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
190 	mutex_unlock(&fi->inmem_lock);
191 
192 	trace_f2fs_register_inmem_page(page, INMEM);
193 }
194 
195 static int __revoke_inmem_pages(struct inode *inode,
196 				struct list_head *head, bool drop, bool recover)
197 {
198 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
199 	struct inmem_pages *cur, *tmp;
200 	int err = 0;
201 
202 	list_for_each_entry_safe(cur, tmp, head, list) {
203 		struct page *page = cur->page;
204 
205 		if (drop)
206 			trace_f2fs_commit_inmem_page(page, INMEM_DROP);
207 
208 		lock_page(page);
209 
210 		if (recover) {
211 			struct dnode_of_data dn;
212 			struct node_info ni;
213 
214 			trace_f2fs_commit_inmem_page(page, INMEM_REVOKE);
215 
216 			set_new_dnode(&dn, inode, NULL, NULL, 0);
217 			if (get_dnode_of_data(&dn, page->index, LOOKUP_NODE)) {
218 				err = -EAGAIN;
219 				goto next;
220 			}
221 			get_node_info(sbi, dn.nid, &ni);
222 			f2fs_replace_block(sbi, &dn, dn.data_blkaddr,
223 					cur->old_addr, ni.version, true, true);
224 			f2fs_put_dnode(&dn);
225 		}
226 next:
227 		/* we don't need to invalidate this in the sccessful status */
228 		if (drop || recover)
229 			ClearPageUptodate(page);
230 		set_page_private(page, 0);
231 		ClearPagePrivate(page);
232 		f2fs_put_page(page, 1);
233 
234 		list_del(&cur->list);
235 		kmem_cache_free(inmem_entry_slab, cur);
236 		dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
237 	}
238 	return err;
239 }
240 
241 void drop_inmem_pages(struct inode *inode)
242 {
243 	struct f2fs_inode_info *fi = F2FS_I(inode);
244 
245 	mutex_lock(&fi->inmem_lock);
246 	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
247 	mutex_unlock(&fi->inmem_lock);
248 
249 	clear_inode_flag(inode, FI_ATOMIC_FILE);
250 	stat_dec_atomic_write(inode);
251 }
252 
253 void drop_inmem_page(struct inode *inode, struct page *page)
254 {
255 	struct f2fs_inode_info *fi = F2FS_I(inode);
256 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
257 	struct list_head *head = &fi->inmem_pages;
258 	struct inmem_pages *cur = NULL;
259 
260 	f2fs_bug_on(sbi, !IS_ATOMIC_WRITTEN_PAGE(page));
261 
262 	mutex_lock(&fi->inmem_lock);
263 	list_for_each_entry(cur, head, list) {
264 		if (cur->page == page)
265 			break;
266 	}
267 
268 	f2fs_bug_on(sbi, !cur || cur->page != page);
269 	list_del(&cur->list);
270 	mutex_unlock(&fi->inmem_lock);
271 
272 	dec_page_count(sbi, F2FS_INMEM_PAGES);
273 	kmem_cache_free(inmem_entry_slab, cur);
274 
275 	ClearPageUptodate(page);
276 	set_page_private(page, 0);
277 	ClearPagePrivate(page);
278 	f2fs_put_page(page, 0);
279 
280 	trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
281 }
282 
283 static int __commit_inmem_pages(struct inode *inode,
284 					struct list_head *revoke_list)
285 {
286 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
287 	struct f2fs_inode_info *fi = F2FS_I(inode);
288 	struct inmem_pages *cur, *tmp;
289 	struct f2fs_io_info fio = {
290 		.sbi = sbi,
291 		.type = DATA,
292 		.op = REQ_OP_WRITE,
293 		.op_flags = REQ_SYNC | REQ_PRIO,
294 		.encrypted_page = NULL,
295 	};
296 	pgoff_t last_idx = ULONG_MAX;
297 	int err = 0;
298 
299 	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
300 		struct page *page = cur->page;
301 
302 		lock_page(page);
303 		if (page->mapping == inode->i_mapping) {
304 			trace_f2fs_commit_inmem_page(page, INMEM);
305 
306 			set_page_dirty(page);
307 			f2fs_wait_on_page_writeback(page, DATA, true);
308 			if (clear_page_dirty_for_io(page)) {
309 				inode_dec_dirty_pages(inode);
310 				remove_dirty_inode(inode);
311 			}
312 
313 			fio.page = page;
314 			err = do_write_data_page(&fio);
315 			if (err) {
316 				unlock_page(page);
317 				break;
318 			}
319 
320 			/* record old blkaddr for revoking */
321 			cur->old_addr = fio.old_blkaddr;
322 			last_idx = page->index;
323 		}
324 		unlock_page(page);
325 		list_move_tail(&cur->list, revoke_list);
326 	}
327 
328 	if (last_idx != ULONG_MAX)
329 		f2fs_submit_merged_bio_cond(sbi, inode, 0, last_idx,
330 							DATA, WRITE);
331 
332 	if (!err)
333 		__revoke_inmem_pages(inode, revoke_list, false, false);
334 
335 	return err;
336 }
337 
338 int commit_inmem_pages(struct inode *inode)
339 {
340 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
341 	struct f2fs_inode_info *fi = F2FS_I(inode);
342 	struct list_head revoke_list;
343 	int err;
344 
345 	INIT_LIST_HEAD(&revoke_list);
346 	f2fs_balance_fs(sbi, true);
347 	f2fs_lock_op(sbi);
348 
349 	set_inode_flag(inode, FI_ATOMIC_COMMIT);
350 
351 	mutex_lock(&fi->inmem_lock);
352 	err = __commit_inmem_pages(inode, &revoke_list);
353 	if (err) {
354 		int ret;
355 		/*
356 		 * try to revoke all committed pages, but still we could fail
357 		 * due to no memory or other reason, if that happened, EAGAIN
358 		 * will be returned, which means in such case, transaction is
359 		 * already not integrity, caller should use journal to do the
360 		 * recovery or rewrite & commit last transaction. For other
361 		 * error number, revoking was done by filesystem itself.
362 		 */
363 		ret = __revoke_inmem_pages(inode, &revoke_list, false, true);
364 		if (ret)
365 			err = ret;
366 
367 		/* drop all uncommitted pages */
368 		__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
369 	}
370 	mutex_unlock(&fi->inmem_lock);
371 
372 	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
373 
374 	f2fs_unlock_op(sbi);
375 	return err;
376 }
377 
378 /*
379  * This function balances dirty node and dentry pages.
380  * In addition, it controls garbage collection.
381  */
382 void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
383 {
384 #ifdef CONFIG_F2FS_FAULT_INJECTION
385 	if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
386 		f2fs_show_injection_info(FAULT_CHECKPOINT);
387 		f2fs_stop_checkpoint(sbi, false);
388 	}
389 #endif
390 
391 	if (!need)
392 		return;
393 
394 	/* balance_fs_bg is able to be pending */
395 	if (excess_cached_nats(sbi))
396 		f2fs_balance_fs_bg(sbi);
397 
398 	/*
399 	 * We should do GC or end up with checkpoint, if there are so many dirty
400 	 * dir/node pages without enough free segments.
401 	 */
402 	if (has_not_enough_free_secs(sbi, 0, 0)) {
403 		mutex_lock(&sbi->gc_mutex);
404 		f2fs_gc(sbi, false, false);
405 	}
406 }
407 
408 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
409 {
410 	/* try to shrink extent cache when there is no enough memory */
411 	if (!available_free_memory(sbi, EXTENT_CACHE))
412 		f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
413 
414 	/* check the # of cached NAT entries */
415 	if (!available_free_memory(sbi, NAT_ENTRIES))
416 		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
417 
418 	if (!available_free_memory(sbi, FREE_NIDS))
419 		try_to_free_nids(sbi, MAX_FREE_NIDS);
420 	else
421 		build_free_nids(sbi, false, false);
422 
423 	if (!is_idle(sbi))
424 		return;
425 
426 	/* checkpoint is the only way to shrink partial cached entries */
427 	if (!available_free_memory(sbi, NAT_ENTRIES) ||
428 			!available_free_memory(sbi, INO_ENTRIES) ||
429 			excess_prefree_segs(sbi) ||
430 			excess_dirty_nats(sbi) ||
431 			f2fs_time_over(sbi, CP_TIME)) {
432 		if (test_opt(sbi, DATA_FLUSH)) {
433 			struct blk_plug plug;
434 
435 			blk_start_plug(&plug);
436 			sync_dirty_inodes(sbi, FILE_INODE);
437 			blk_finish_plug(&plug);
438 		}
439 		f2fs_sync_fs(sbi->sb, true);
440 		stat_inc_bg_cp_count(sbi->stat_info);
441 	}
442 }
443 
444 static int __submit_flush_wait(struct f2fs_sb_info *sbi,
445 				struct block_device *bdev)
446 {
447 	struct bio *bio = f2fs_bio_alloc(0);
448 	int ret;
449 
450 	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
451 	bio->bi_bdev = bdev;
452 	ret = submit_bio_wait(bio);
453 	bio_put(bio);
454 
455 	trace_f2fs_issue_flush(bdev, test_opt(sbi, NOBARRIER),
456 				test_opt(sbi, FLUSH_MERGE), ret);
457 	return ret;
458 }
459 
460 static int submit_flush_wait(struct f2fs_sb_info *sbi)
461 {
462 	int ret = __submit_flush_wait(sbi, sbi->sb->s_bdev);
463 	int i;
464 
465 	if (!sbi->s_ndevs || ret)
466 		return ret;
467 
468 	for (i = 1; i < sbi->s_ndevs; i++) {
469 		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
470 		if (ret)
471 			break;
472 	}
473 	return ret;
474 }
475 
476 static int issue_flush_thread(void *data)
477 {
478 	struct f2fs_sb_info *sbi = data;
479 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
480 	wait_queue_head_t *q = &fcc->flush_wait_queue;
481 repeat:
482 	if (kthread_should_stop())
483 		return 0;
484 
485 	if (!llist_empty(&fcc->issue_list)) {
486 		struct flush_cmd *cmd, *next;
487 		int ret;
488 
489 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
490 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
491 
492 		ret = submit_flush_wait(sbi);
493 		atomic_inc(&fcc->issued_flush);
494 
495 		llist_for_each_entry_safe(cmd, next,
496 					  fcc->dispatch_list, llnode) {
497 			cmd->ret = ret;
498 			complete(&cmd->wait);
499 		}
500 		fcc->dispatch_list = NULL;
501 	}
502 
503 	wait_event_interruptible(*q,
504 		kthread_should_stop() || !llist_empty(&fcc->issue_list));
505 	goto repeat;
506 }
507 
508 int f2fs_issue_flush(struct f2fs_sb_info *sbi)
509 {
510 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
511 	struct flush_cmd cmd;
512 	int ret;
513 
514 	if (test_opt(sbi, NOBARRIER))
515 		return 0;
516 
517 	if (!test_opt(sbi, FLUSH_MERGE)) {
518 		ret = submit_flush_wait(sbi);
519 		atomic_inc(&fcc->issued_flush);
520 		return ret;
521 	}
522 
523 	if (!atomic_read(&fcc->issing_flush)) {
524 		atomic_inc(&fcc->issing_flush);
525 		ret = submit_flush_wait(sbi);
526 		atomic_dec(&fcc->issing_flush);
527 
528 		atomic_inc(&fcc->issued_flush);
529 		return ret;
530 	}
531 
532 	init_completion(&cmd.wait);
533 
534 	atomic_inc(&fcc->issing_flush);
535 	llist_add(&cmd.llnode, &fcc->issue_list);
536 
537 	if (!fcc->dispatch_list)
538 		wake_up(&fcc->flush_wait_queue);
539 
540 	if (fcc->f2fs_issue_flush) {
541 		wait_for_completion(&cmd.wait);
542 		atomic_dec(&fcc->issing_flush);
543 	} else {
544 		llist_del_all(&fcc->issue_list);
545 		atomic_set(&fcc->issing_flush, 0);
546 	}
547 
548 	return cmd.ret;
549 }
550 
551 int create_flush_cmd_control(struct f2fs_sb_info *sbi)
552 {
553 	dev_t dev = sbi->sb->s_bdev->bd_dev;
554 	struct flush_cmd_control *fcc;
555 	int err = 0;
556 
557 	if (SM_I(sbi)->fcc_info) {
558 		fcc = SM_I(sbi)->fcc_info;
559 		goto init_thread;
560 	}
561 
562 	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
563 	if (!fcc)
564 		return -ENOMEM;
565 	atomic_set(&fcc->issued_flush, 0);
566 	atomic_set(&fcc->issing_flush, 0);
567 	init_waitqueue_head(&fcc->flush_wait_queue);
568 	init_llist_head(&fcc->issue_list);
569 	SM_I(sbi)->fcc_info = fcc;
570 init_thread:
571 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
572 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
573 	if (IS_ERR(fcc->f2fs_issue_flush)) {
574 		err = PTR_ERR(fcc->f2fs_issue_flush);
575 		kfree(fcc);
576 		SM_I(sbi)->fcc_info = NULL;
577 		return err;
578 	}
579 
580 	return err;
581 }
582 
583 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
584 {
585 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
586 
587 	if (fcc && fcc->f2fs_issue_flush) {
588 		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
589 
590 		fcc->f2fs_issue_flush = NULL;
591 		kthread_stop(flush_thread);
592 	}
593 	if (free) {
594 		kfree(fcc);
595 		SM_I(sbi)->fcc_info = NULL;
596 	}
597 }
598 
599 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
600 		enum dirty_type dirty_type)
601 {
602 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
603 
604 	/* need not be added */
605 	if (IS_CURSEG(sbi, segno))
606 		return;
607 
608 	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
609 		dirty_i->nr_dirty[dirty_type]++;
610 
611 	if (dirty_type == DIRTY) {
612 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
613 		enum dirty_type t = sentry->type;
614 
615 		if (unlikely(t >= DIRTY)) {
616 			f2fs_bug_on(sbi, 1);
617 			return;
618 		}
619 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
620 			dirty_i->nr_dirty[t]++;
621 	}
622 }
623 
624 static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
625 		enum dirty_type dirty_type)
626 {
627 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
628 
629 	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
630 		dirty_i->nr_dirty[dirty_type]--;
631 
632 	if (dirty_type == DIRTY) {
633 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
634 		enum dirty_type t = sentry->type;
635 
636 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
637 			dirty_i->nr_dirty[t]--;
638 
639 		if (get_valid_blocks(sbi, segno, true) == 0)
640 			clear_bit(GET_SEC_FROM_SEG(sbi, segno),
641 						dirty_i->victim_secmap);
642 	}
643 }
644 
645 /*
646  * Should not occur error such as -ENOMEM.
647  * Adding dirty entry into seglist is not critical operation.
648  * If a given segment is one of current working segments, it won't be added.
649  */
650 static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
651 {
652 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
653 	unsigned short valid_blocks;
654 
655 	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
656 		return;
657 
658 	mutex_lock(&dirty_i->seglist_lock);
659 
660 	valid_blocks = get_valid_blocks(sbi, segno, false);
661 
662 	if (valid_blocks == 0) {
663 		__locate_dirty_segment(sbi, segno, PRE);
664 		__remove_dirty_segment(sbi, segno, DIRTY);
665 	} else if (valid_blocks < sbi->blocks_per_seg) {
666 		__locate_dirty_segment(sbi, segno, DIRTY);
667 	} else {
668 		/* Recovery routine with SSR needs this */
669 		__remove_dirty_segment(sbi, segno, DIRTY);
670 	}
671 
672 	mutex_unlock(&dirty_i->seglist_lock);
673 }
674 
675 static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi,
676 		struct block_device *bdev, block_t lstart,
677 		block_t start, block_t len)
678 {
679 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
680 	struct list_head *pend_list = &(dcc->pend_list);
681 	struct discard_cmd *dc;
682 
683 	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
684 	INIT_LIST_HEAD(&dc->list);
685 	dc->bdev = bdev;
686 	dc->lstart = lstart;
687 	dc->start = start;
688 	dc->len = len;
689 	dc->state = D_PREP;
690 	dc->error = 0;
691 	init_completion(&dc->wait);
692 	list_add_tail(&dc->list, pend_list);
693 	atomic_inc(&dcc->discard_cmd_cnt);
694 
695 	return dc;
696 }
697 
698 static struct discard_cmd *__attach_discard_cmd(struct f2fs_sb_info *sbi,
699 				struct block_device *bdev, block_t lstart,
700 				block_t start, block_t len,
701 				struct rb_node *parent, struct rb_node **p)
702 {
703 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
704 	struct discard_cmd *dc;
705 
706 	dc = __create_discard_cmd(sbi, bdev, lstart, start, len);
707 
708 	rb_link_node(&dc->rb_node, parent, p);
709 	rb_insert_color(&dc->rb_node, &dcc->root);
710 
711 	return dc;
712 }
713 
714 static void __detach_discard_cmd(struct discard_cmd_control *dcc,
715 							struct discard_cmd *dc)
716 {
717 	if (dc->state == D_DONE)
718 		atomic_dec(&dcc->issing_discard);
719 
720 	list_del(&dc->list);
721 	rb_erase(&dc->rb_node, &dcc->root);
722 
723 	kmem_cache_free(discard_cmd_slab, dc);
724 
725 	atomic_dec(&dcc->discard_cmd_cnt);
726 }
727 
728 static void __remove_discard_cmd(struct f2fs_sb_info *sbi,
729 							struct discard_cmd *dc)
730 {
731 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
732 
733 	if (dc->error == -EOPNOTSUPP)
734 		dc->error = 0;
735 
736 	if (dc->error)
737 		f2fs_msg(sbi->sb, KERN_INFO,
738 				"Issue discard failed, ret: %d", dc->error);
739 	__detach_discard_cmd(dcc, dc);
740 }
741 
742 static void f2fs_submit_discard_endio(struct bio *bio)
743 {
744 	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
745 
746 	dc->error = bio->bi_error;
747 	dc->state = D_DONE;
748 	complete(&dc->wait);
749 	bio_put(bio);
750 }
751 
752 /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
753 static void __submit_discard_cmd(struct f2fs_sb_info *sbi,
754 				struct discard_cmd *dc)
755 {
756 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
757 	struct bio *bio = NULL;
758 
759 	if (dc->state != D_PREP)
760 		return;
761 
762 	dc->error = __blkdev_issue_discard(dc->bdev,
763 				SECTOR_FROM_BLOCK(dc->start),
764 				SECTOR_FROM_BLOCK(dc->len),
765 				GFP_NOFS, 0, &bio);
766 	if (!dc->error) {
767 		/* should keep before submission to avoid D_DONE right away */
768 		dc->state = D_SUBMIT;
769 		atomic_inc(&dcc->issued_discard);
770 		atomic_inc(&dcc->issing_discard);
771 		if (bio) {
772 			bio->bi_private = dc;
773 			bio->bi_end_io = f2fs_submit_discard_endio;
774 			bio->bi_opf |= REQ_SYNC;
775 			submit_bio(bio);
776 			list_move_tail(&dc->list, &dcc->wait_list);
777 		}
778 	} else {
779 		__remove_discard_cmd(sbi, dc);
780 	}
781 }
782 
783 static struct discard_cmd *__insert_discard_tree(struct f2fs_sb_info *sbi,
784 				struct block_device *bdev, block_t lstart,
785 				block_t start, block_t len,
786 				struct rb_node **insert_p,
787 				struct rb_node *insert_parent)
788 {
789 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
790 	struct rb_node **p = &dcc->root.rb_node;
791 	struct rb_node *parent = NULL;
792 	struct discard_cmd *dc = NULL;
793 
794 	if (insert_p && insert_parent) {
795 		parent = insert_parent;
796 		p = insert_p;
797 		goto do_insert;
798 	}
799 
800 	p = __lookup_rb_tree_for_insert(sbi, &dcc->root, &parent, lstart);
801 do_insert:
802 	dc = __attach_discard_cmd(sbi, bdev, lstart, start, len, parent, p);
803 	if (!dc)
804 		return NULL;
805 
806 	return dc;
807 }
808 
809 static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
810 				struct discard_cmd *dc, block_t blkaddr)
811 {
812 	struct discard_info di = dc->di;
813 	bool modified = false;
814 
815 	if (dc->state == D_DONE || dc->len == 1) {
816 		__remove_discard_cmd(sbi, dc);
817 		return;
818 	}
819 
820 	if (blkaddr > di.lstart) {
821 		dc->len = blkaddr - dc->lstart;
822 		modified = true;
823 	}
824 
825 	if (blkaddr < di.lstart + di.len - 1) {
826 		if (modified) {
827 			__insert_discard_tree(sbi, dc->bdev, blkaddr + 1,
828 					di.start + blkaddr + 1 - di.lstart,
829 					di.lstart + di.len - 1 - blkaddr,
830 					NULL, NULL);
831 		} else {
832 			dc->lstart++;
833 			dc->len--;
834 			dc->start++;
835 		}
836 	}
837 }
838 
839 static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
840 				struct block_device *bdev, block_t lstart,
841 				block_t start, block_t len)
842 {
843 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
844 	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
845 	struct discard_cmd *dc;
846 	struct discard_info di = {0};
847 	struct rb_node **insert_p = NULL, *insert_parent = NULL;
848 	block_t end = lstart + len;
849 
850 	mutex_lock(&dcc->cmd_lock);
851 
852 	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
853 					NULL, lstart,
854 					(struct rb_entry **)&prev_dc,
855 					(struct rb_entry **)&next_dc,
856 					&insert_p, &insert_parent, true);
857 	if (dc)
858 		prev_dc = dc;
859 
860 	if (!prev_dc) {
861 		di.lstart = lstart;
862 		di.len = next_dc ? next_dc->lstart - lstart : len;
863 		di.len = min(di.len, len);
864 		di.start = start;
865 	}
866 
867 	while (1) {
868 		struct rb_node *node;
869 		bool merged = false;
870 		struct discard_cmd *tdc = NULL;
871 
872 		if (prev_dc) {
873 			di.lstart = prev_dc->lstart + prev_dc->len;
874 			if (di.lstart < lstart)
875 				di.lstart = lstart;
876 			if (di.lstart >= end)
877 				break;
878 
879 			if (!next_dc || next_dc->lstart > end)
880 				di.len = end - di.lstart;
881 			else
882 				di.len = next_dc->lstart - di.lstart;
883 			di.start = start + di.lstart - lstart;
884 		}
885 
886 		if (!di.len)
887 			goto next;
888 
889 		if (prev_dc && prev_dc->state == D_PREP &&
890 			prev_dc->bdev == bdev &&
891 			__is_discard_back_mergeable(&di, &prev_dc->di)) {
892 			prev_dc->di.len += di.len;
893 			di = prev_dc->di;
894 			tdc = prev_dc;
895 			merged = true;
896 		}
897 
898 		if (next_dc && next_dc->state == D_PREP &&
899 			next_dc->bdev == bdev &&
900 			__is_discard_front_mergeable(&di, &next_dc->di)) {
901 			next_dc->di.lstart = di.lstart;
902 			next_dc->di.len += di.len;
903 			next_dc->di.start = di.start;
904 			if (tdc)
905 				__remove_discard_cmd(sbi, tdc);
906 
907 			merged = true;
908 		}
909 
910 		if (!merged)
911 			__insert_discard_tree(sbi, bdev, di.lstart, di.start,
912 							di.len, NULL, NULL);
913  next:
914 		prev_dc = next_dc;
915 		if (!prev_dc)
916 			break;
917 
918 		node = rb_next(&prev_dc->rb_node);
919 		next_dc = rb_entry_safe(node, struct discard_cmd, rb_node);
920 	}
921 
922 	mutex_unlock(&dcc->cmd_lock);
923 }
924 
925 static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
926 		struct block_device *bdev, block_t blkstart, block_t blklen)
927 {
928 	block_t lblkstart = blkstart;
929 
930 	trace_f2fs_issue_discard(bdev, blkstart, blklen);
931 
932 	if (sbi->s_ndevs) {
933 		int devi = f2fs_target_device_index(sbi, blkstart);
934 
935 		blkstart -= FDEV(devi).start_blk;
936 	}
937 	__update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
938 	wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
939 	return 0;
940 }
941 
942 /* This should be covered by global mutex, &sit_i->sentry_lock */
943 void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
944 {
945 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
946 	struct discard_cmd *dc;
947 
948 	mutex_lock(&dcc->cmd_lock);
949 
950 	dc = (struct discard_cmd *)__lookup_rb_tree(&dcc->root, NULL, blkaddr);
951 	if (dc) {
952 		if (dc->state != D_PREP)
953 			wait_for_completion_io(&dc->wait);
954 		__punch_discard_cmd(sbi, dc, blkaddr);
955 	}
956 
957 	mutex_unlock(&dcc->cmd_lock);
958 }
959 
960 /* This comes from f2fs_put_super */
961 void f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
962 {
963 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
964 	struct list_head *pend_list = &(dcc->pend_list);
965 	struct list_head *wait_list = &(dcc->wait_list);
966 	struct discard_cmd *dc, *tmp;
967 	struct blk_plug plug;
968 
969 	mutex_lock(&dcc->cmd_lock);
970 
971 	blk_start_plug(&plug);
972 	list_for_each_entry_safe(dc, tmp, pend_list, list)
973 		__submit_discard_cmd(sbi, dc);
974 	blk_finish_plug(&plug);
975 
976 	list_for_each_entry_safe(dc, tmp, wait_list, list) {
977 		wait_for_completion_io(&dc->wait);
978 		__remove_discard_cmd(sbi, dc);
979 	}
980 
981 	mutex_unlock(&dcc->cmd_lock);
982 }
983 
984 static int issue_discard_thread(void *data)
985 {
986 	struct f2fs_sb_info *sbi = data;
987 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
988 	wait_queue_head_t *q = &dcc->discard_wait_queue;
989 	struct list_head *pend_list = &dcc->pend_list;
990 	struct list_head *wait_list = &dcc->wait_list;
991 	struct discard_cmd *dc, *tmp;
992 	struct blk_plug plug;
993 	int iter = 0;
994 repeat:
995 	if (kthread_should_stop())
996 		return 0;
997 
998 	mutex_lock(&dcc->cmd_lock);
999 	blk_start_plug(&plug);
1000 	list_for_each_entry_safe(dc, tmp, pend_list, list) {
1001 		f2fs_bug_on(sbi, dc->state != D_PREP);
1002 
1003 		if (is_idle(sbi))
1004 			__submit_discard_cmd(sbi, dc);
1005 
1006 		if (iter++ > DISCARD_ISSUE_RATE)
1007 			break;
1008 	}
1009 	blk_finish_plug(&plug);
1010 
1011 	list_for_each_entry_safe(dc, tmp, wait_list, list) {
1012 		if (dc->state == D_DONE) {
1013 			wait_for_completion_io(&dc->wait);
1014 			__remove_discard_cmd(sbi, dc);
1015 		}
1016 	}
1017 	mutex_unlock(&dcc->cmd_lock);
1018 
1019 	iter = 0;
1020 	congestion_wait(BLK_RW_SYNC, HZ/50);
1021 
1022 	wait_event_interruptible(*q, kthread_should_stop() ||
1023 			!list_empty(pend_list) || !list_empty(wait_list));
1024 	goto repeat;
1025 }
1026 
1027 #ifdef CONFIG_BLK_DEV_ZONED
1028 static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
1029 		struct block_device *bdev, block_t blkstart, block_t blklen)
1030 {
1031 	sector_t sector, nr_sects;
1032 	block_t lblkstart = blkstart;
1033 	int devi = 0;
1034 
1035 	if (sbi->s_ndevs) {
1036 		devi = f2fs_target_device_index(sbi, blkstart);
1037 		blkstart -= FDEV(devi).start_blk;
1038 	}
1039 
1040 	/*
1041 	 * We need to know the type of the zone: for conventional zones,
1042 	 * use regular discard if the drive supports it. For sequential
1043 	 * zones, reset the zone write pointer.
1044 	 */
1045 	switch (get_blkz_type(sbi, bdev, blkstart)) {
1046 
1047 	case BLK_ZONE_TYPE_CONVENTIONAL:
1048 		if (!blk_queue_discard(bdev_get_queue(bdev)))
1049 			return 0;
1050 		return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
1051 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
1052 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
1053 		sector = SECTOR_FROM_BLOCK(blkstart);
1054 		nr_sects = SECTOR_FROM_BLOCK(blklen);
1055 
1056 		if (sector & (bdev_zone_sectors(bdev) - 1) ||
1057 				nr_sects != bdev_zone_sectors(bdev)) {
1058 			f2fs_msg(sbi->sb, KERN_INFO,
1059 				"(%d) %s: Unaligned discard attempted (block %x + %x)",
1060 				devi, sbi->s_ndevs ? FDEV(devi).path: "",
1061 				blkstart, blklen);
1062 			return -EIO;
1063 		}
1064 		trace_f2fs_issue_reset_zone(bdev, blkstart);
1065 		return blkdev_reset_zones(bdev, sector,
1066 					  nr_sects, GFP_NOFS);
1067 	default:
1068 		/* Unknown zone type: broken device ? */
1069 		return -EIO;
1070 	}
1071 }
1072 #endif
1073 
1074 static int __issue_discard_async(struct f2fs_sb_info *sbi,
1075 		struct block_device *bdev, block_t blkstart, block_t blklen)
1076 {
1077 #ifdef CONFIG_BLK_DEV_ZONED
1078 	if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
1079 				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
1080 		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
1081 #endif
1082 	return __queue_discard_cmd(sbi, bdev, blkstart, blklen);
1083 }
1084 
1085 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
1086 				block_t blkstart, block_t blklen)
1087 {
1088 	sector_t start = blkstart, len = 0;
1089 	struct block_device *bdev;
1090 	struct seg_entry *se;
1091 	unsigned int offset;
1092 	block_t i;
1093 	int err = 0;
1094 
1095 	bdev = f2fs_target_device(sbi, blkstart, NULL);
1096 
1097 	for (i = blkstart; i < blkstart + blklen; i++, len++) {
1098 		if (i != start) {
1099 			struct block_device *bdev2 =
1100 				f2fs_target_device(sbi, i, NULL);
1101 
1102 			if (bdev2 != bdev) {
1103 				err = __issue_discard_async(sbi, bdev,
1104 						start, len);
1105 				if (err)
1106 					return err;
1107 				bdev = bdev2;
1108 				start = i;
1109 				len = 0;
1110 			}
1111 		}
1112 
1113 		se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
1114 		offset = GET_BLKOFF_FROM_SEG0(sbi, i);
1115 
1116 		if (!f2fs_test_and_set_bit(offset, se->discard_map))
1117 			sbi->discard_blks--;
1118 	}
1119 
1120 	if (len)
1121 		err = __issue_discard_async(sbi, bdev, start, len);
1122 	return err;
1123 }
1124 
1125 static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
1126 							bool check_only)
1127 {
1128 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1129 	int max_blocks = sbi->blocks_per_seg;
1130 	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
1131 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1132 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1133 	unsigned long *discard_map = (unsigned long *)se->discard_map;
1134 	unsigned long *dmap = SIT_I(sbi)->tmp_map;
1135 	unsigned int start = 0, end = -1;
1136 	bool force = (cpc->reason == CP_DISCARD);
1137 	struct discard_entry *de = NULL;
1138 	struct list_head *head = &SM_I(sbi)->dcc_info->entry_list;
1139 	int i;
1140 
1141 	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
1142 		return false;
1143 
1144 	if (!force) {
1145 		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
1146 			SM_I(sbi)->dcc_info->nr_discards >=
1147 				SM_I(sbi)->dcc_info->max_discards)
1148 			return false;
1149 	}
1150 
1151 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
1152 	for (i = 0; i < entries; i++)
1153 		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
1154 				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
1155 
1156 	while (force || SM_I(sbi)->dcc_info->nr_discards <=
1157 				SM_I(sbi)->dcc_info->max_discards) {
1158 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
1159 		if (start >= max_blocks)
1160 			break;
1161 
1162 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
1163 		if (force && start && end != max_blocks
1164 					&& (end - start) < cpc->trim_minlen)
1165 			continue;
1166 
1167 		if (check_only)
1168 			return true;
1169 
1170 		if (!de) {
1171 			de = f2fs_kmem_cache_alloc(discard_entry_slab,
1172 								GFP_F2FS_ZERO);
1173 			de->start_blkaddr = START_BLOCK(sbi, cpc->trim_start);
1174 			list_add_tail(&de->list, head);
1175 		}
1176 
1177 		for (i = start; i < end; i++)
1178 			__set_bit_le(i, (void *)de->discard_map);
1179 
1180 		SM_I(sbi)->dcc_info->nr_discards += end - start;
1181 	}
1182 	return false;
1183 }
1184 
1185 void release_discard_addrs(struct f2fs_sb_info *sbi)
1186 {
1187 	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
1188 	struct discard_entry *entry, *this;
1189 
1190 	/* drop caches */
1191 	list_for_each_entry_safe(entry, this, head, list) {
1192 		list_del(&entry->list);
1193 		kmem_cache_free(discard_entry_slab, entry);
1194 	}
1195 }
1196 
1197 /*
1198  * Should call clear_prefree_segments after checkpoint is done.
1199  */
1200 static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
1201 {
1202 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1203 	unsigned int segno;
1204 
1205 	mutex_lock(&dirty_i->seglist_lock);
1206 	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
1207 		__set_test_and_free(sbi, segno);
1208 	mutex_unlock(&dirty_i->seglist_lock);
1209 }
1210 
1211 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1212 {
1213 	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
1214 	struct discard_entry *entry, *this;
1215 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1216 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
1217 	unsigned int start = 0, end = -1;
1218 	unsigned int secno, start_segno;
1219 	bool force = (cpc->reason == CP_DISCARD);
1220 
1221 	mutex_lock(&dirty_i->seglist_lock);
1222 
1223 	while (1) {
1224 		int i;
1225 		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
1226 		if (start >= MAIN_SEGS(sbi))
1227 			break;
1228 		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
1229 								start + 1);
1230 
1231 		for (i = start; i < end; i++)
1232 			clear_bit(i, prefree_map);
1233 
1234 		dirty_i->nr_dirty[PRE] -= end - start;
1235 
1236 		if (!test_opt(sbi, DISCARD))
1237 			continue;
1238 
1239 		if (force && start >= cpc->trim_start &&
1240 					(end - 1) <= cpc->trim_end)
1241 				continue;
1242 
1243 		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
1244 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
1245 				(end - start) << sbi->log_blocks_per_seg);
1246 			continue;
1247 		}
1248 next:
1249 		secno = GET_SEC_FROM_SEG(sbi, start);
1250 		start_segno = GET_SEG_FROM_SEC(sbi, secno);
1251 		if (!IS_CURSEC(sbi, secno) &&
1252 			!get_valid_blocks(sbi, start, true))
1253 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
1254 				sbi->segs_per_sec << sbi->log_blocks_per_seg);
1255 
1256 		start = start_segno + sbi->segs_per_sec;
1257 		if (start < end)
1258 			goto next;
1259 		else
1260 			end = start - 1;
1261 	}
1262 	mutex_unlock(&dirty_i->seglist_lock);
1263 
1264 	/* send small discards */
1265 	list_for_each_entry_safe(entry, this, head, list) {
1266 		unsigned int cur_pos = 0, next_pos, len, total_len = 0;
1267 		bool is_valid = test_bit_le(0, entry->discard_map);
1268 
1269 find_next:
1270 		if (is_valid) {
1271 			next_pos = find_next_zero_bit_le(entry->discard_map,
1272 					sbi->blocks_per_seg, cur_pos);
1273 			len = next_pos - cur_pos;
1274 
1275 			if (force && len < cpc->trim_minlen)
1276 				goto skip;
1277 
1278 			f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
1279 									len);
1280 			cpc->trimmed += len;
1281 			total_len += len;
1282 		} else {
1283 			next_pos = find_next_bit_le(entry->discard_map,
1284 					sbi->blocks_per_seg, cur_pos);
1285 		}
1286 skip:
1287 		cur_pos = next_pos;
1288 		is_valid = !is_valid;
1289 
1290 		if (cur_pos < sbi->blocks_per_seg)
1291 			goto find_next;
1292 
1293 		list_del(&entry->list);
1294 		SM_I(sbi)->dcc_info->nr_discards -= total_len;
1295 		kmem_cache_free(discard_entry_slab, entry);
1296 	}
1297 }
1298 
1299 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
1300 {
1301 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1302 	struct discard_cmd_control *dcc;
1303 	int err = 0;
1304 
1305 	if (SM_I(sbi)->dcc_info) {
1306 		dcc = SM_I(sbi)->dcc_info;
1307 		goto init_thread;
1308 	}
1309 
1310 	dcc = kzalloc(sizeof(struct discard_cmd_control), GFP_KERNEL);
1311 	if (!dcc)
1312 		return -ENOMEM;
1313 
1314 	INIT_LIST_HEAD(&dcc->entry_list);
1315 	INIT_LIST_HEAD(&dcc->pend_list);
1316 	INIT_LIST_HEAD(&dcc->wait_list);
1317 	mutex_init(&dcc->cmd_lock);
1318 	atomic_set(&dcc->issued_discard, 0);
1319 	atomic_set(&dcc->issing_discard, 0);
1320 	atomic_set(&dcc->discard_cmd_cnt, 0);
1321 	dcc->nr_discards = 0;
1322 	dcc->max_discards = 0;
1323 	dcc->root = RB_ROOT;
1324 
1325 	init_waitqueue_head(&dcc->discard_wait_queue);
1326 	SM_I(sbi)->dcc_info = dcc;
1327 init_thread:
1328 	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
1329 				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
1330 	if (IS_ERR(dcc->f2fs_issue_discard)) {
1331 		err = PTR_ERR(dcc->f2fs_issue_discard);
1332 		kfree(dcc);
1333 		SM_I(sbi)->dcc_info = NULL;
1334 		return err;
1335 	}
1336 
1337 	return err;
1338 }
1339 
1340 static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
1341 {
1342 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1343 
1344 	if (!dcc)
1345 		return;
1346 
1347 	if (dcc->f2fs_issue_discard) {
1348 		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
1349 
1350 		dcc->f2fs_issue_discard = NULL;
1351 		kthread_stop(discard_thread);
1352 	}
1353 
1354 	kfree(dcc);
1355 	SM_I(sbi)->dcc_info = NULL;
1356 }
1357 
1358 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
1359 {
1360 	struct sit_info *sit_i = SIT_I(sbi);
1361 
1362 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
1363 		sit_i->dirty_sentries++;
1364 		return false;
1365 	}
1366 
1367 	return true;
1368 }
1369 
1370 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
1371 					unsigned int segno, int modified)
1372 {
1373 	struct seg_entry *se = get_seg_entry(sbi, segno);
1374 	se->type = type;
1375 	if (modified)
1376 		__mark_sit_entry_dirty(sbi, segno);
1377 }
1378 
1379 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
1380 {
1381 	struct seg_entry *se;
1382 	unsigned int segno, offset;
1383 	long int new_vblocks;
1384 
1385 	segno = GET_SEGNO(sbi, blkaddr);
1386 
1387 	se = get_seg_entry(sbi, segno);
1388 	new_vblocks = se->valid_blocks + del;
1389 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1390 
1391 	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
1392 				(new_vblocks > sbi->blocks_per_seg)));
1393 
1394 	se->valid_blocks = new_vblocks;
1395 	se->mtime = get_mtime(sbi);
1396 	SIT_I(sbi)->max_mtime = se->mtime;
1397 
1398 	/* Update valid block bitmap */
1399 	if (del > 0) {
1400 		if (f2fs_test_and_set_bit(offset, se->cur_valid_map)) {
1401 #ifdef CONFIG_F2FS_CHECK_FS
1402 			if (f2fs_test_and_set_bit(offset,
1403 						se->cur_valid_map_mir))
1404 				f2fs_bug_on(sbi, 1);
1405 			else
1406 				WARN_ON(1);
1407 #else
1408 			f2fs_bug_on(sbi, 1);
1409 #endif
1410 		}
1411 		if (f2fs_discard_en(sbi) &&
1412 			!f2fs_test_and_set_bit(offset, se->discard_map))
1413 			sbi->discard_blks--;
1414 
1415 		/* don't overwrite by SSR to keep node chain */
1416 		if (se->type == CURSEG_WARM_NODE) {
1417 			if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map))
1418 				se->ckpt_valid_blocks++;
1419 		}
1420 	} else {
1421 		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) {
1422 #ifdef CONFIG_F2FS_CHECK_FS
1423 			if (!f2fs_test_and_clear_bit(offset,
1424 						se->cur_valid_map_mir))
1425 				f2fs_bug_on(sbi, 1);
1426 			else
1427 				WARN_ON(1);
1428 #else
1429 			f2fs_bug_on(sbi, 1);
1430 #endif
1431 		}
1432 		if (f2fs_discard_en(sbi) &&
1433 			f2fs_test_and_clear_bit(offset, se->discard_map))
1434 			sbi->discard_blks++;
1435 	}
1436 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
1437 		se->ckpt_valid_blocks += del;
1438 
1439 	__mark_sit_entry_dirty(sbi, segno);
1440 
1441 	/* update total number of valid blocks to be written in ckpt area */
1442 	SIT_I(sbi)->written_valid_blocks += del;
1443 
1444 	if (sbi->segs_per_sec > 1)
1445 		get_sec_entry(sbi, segno)->valid_blocks += del;
1446 }
1447 
1448 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
1449 {
1450 	update_sit_entry(sbi, new, 1);
1451 	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
1452 		update_sit_entry(sbi, old, -1);
1453 
1454 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
1455 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
1456 }
1457 
1458 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
1459 {
1460 	unsigned int segno = GET_SEGNO(sbi, addr);
1461 	struct sit_info *sit_i = SIT_I(sbi);
1462 
1463 	f2fs_bug_on(sbi, addr == NULL_ADDR);
1464 	if (addr == NEW_ADDR)
1465 		return;
1466 
1467 	/* add it into sit main buffer */
1468 	mutex_lock(&sit_i->sentry_lock);
1469 
1470 	update_sit_entry(sbi, addr, -1);
1471 
1472 	/* add it into dirty seglist */
1473 	locate_dirty_segment(sbi, segno);
1474 
1475 	mutex_unlock(&sit_i->sentry_lock);
1476 }
1477 
1478 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
1479 {
1480 	struct sit_info *sit_i = SIT_I(sbi);
1481 	unsigned int segno, offset;
1482 	struct seg_entry *se;
1483 	bool is_cp = false;
1484 
1485 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1486 		return true;
1487 
1488 	mutex_lock(&sit_i->sentry_lock);
1489 
1490 	segno = GET_SEGNO(sbi, blkaddr);
1491 	se = get_seg_entry(sbi, segno);
1492 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1493 
1494 	if (f2fs_test_bit(offset, se->ckpt_valid_map))
1495 		is_cp = true;
1496 
1497 	mutex_unlock(&sit_i->sentry_lock);
1498 
1499 	return is_cp;
1500 }
1501 
1502 /*
1503  * This function should be resided under the curseg_mutex lock
1504  */
1505 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
1506 					struct f2fs_summary *sum)
1507 {
1508 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1509 	void *addr = curseg->sum_blk;
1510 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
1511 	memcpy(addr, sum, sizeof(struct f2fs_summary));
1512 }
1513 
1514 /*
1515  * Calculate the number of current summary pages for writing
1516  */
1517 int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
1518 {
1519 	int valid_sum_count = 0;
1520 	int i, sum_in_page;
1521 
1522 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1523 		if (sbi->ckpt->alloc_type[i] == SSR)
1524 			valid_sum_count += sbi->blocks_per_seg;
1525 		else {
1526 			if (for_ra)
1527 				valid_sum_count += le16_to_cpu(
1528 					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
1529 			else
1530 				valid_sum_count += curseg_blkoff(sbi, i);
1531 		}
1532 	}
1533 
1534 	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
1535 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
1536 	if (valid_sum_count <= sum_in_page)
1537 		return 1;
1538 	else if ((valid_sum_count - sum_in_page) <=
1539 		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
1540 		return 2;
1541 	return 3;
1542 }
1543 
1544 /*
1545  * Caller should put this summary page
1546  */
1547 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
1548 {
1549 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
1550 }
1551 
1552 void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
1553 {
1554 	struct page *page = grab_meta_page(sbi, blk_addr);
1555 	void *dst = page_address(page);
1556 
1557 	if (src)
1558 		memcpy(dst, src, PAGE_SIZE);
1559 	else
1560 		memset(dst, 0, PAGE_SIZE);
1561 	set_page_dirty(page);
1562 	f2fs_put_page(page, 1);
1563 }
1564 
1565 static void write_sum_page(struct f2fs_sb_info *sbi,
1566 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
1567 {
1568 	update_meta_page(sbi, (void *)sum_blk, blk_addr);
1569 }
1570 
1571 static void write_current_sum_page(struct f2fs_sb_info *sbi,
1572 						int type, block_t blk_addr)
1573 {
1574 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1575 	struct page *page = grab_meta_page(sbi, blk_addr);
1576 	struct f2fs_summary_block *src = curseg->sum_blk;
1577 	struct f2fs_summary_block *dst;
1578 
1579 	dst = (struct f2fs_summary_block *)page_address(page);
1580 
1581 	mutex_lock(&curseg->curseg_mutex);
1582 
1583 	down_read(&curseg->journal_rwsem);
1584 	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
1585 	up_read(&curseg->journal_rwsem);
1586 
1587 	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
1588 	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
1589 
1590 	mutex_unlock(&curseg->curseg_mutex);
1591 
1592 	set_page_dirty(page);
1593 	f2fs_put_page(page, 1);
1594 }
1595 
1596 /*
1597  * Find a new segment from the free segments bitmap to right order
1598  * This function should be returned with success, otherwise BUG
1599  */
1600 static void get_new_segment(struct f2fs_sb_info *sbi,
1601 			unsigned int *newseg, bool new_sec, int dir)
1602 {
1603 	struct free_segmap_info *free_i = FREE_I(sbi);
1604 	unsigned int segno, secno, zoneno;
1605 	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
1606 	unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
1607 	unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
1608 	unsigned int left_start = hint;
1609 	bool init = true;
1610 	int go_left = 0;
1611 	int i;
1612 
1613 	spin_lock(&free_i->segmap_lock);
1614 
1615 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
1616 		segno = find_next_zero_bit(free_i->free_segmap,
1617 			GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
1618 		if (segno < GET_SEG_FROM_SEC(sbi, hint + 1))
1619 			goto got_it;
1620 	}
1621 find_other_zone:
1622 	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
1623 	if (secno >= MAIN_SECS(sbi)) {
1624 		if (dir == ALLOC_RIGHT) {
1625 			secno = find_next_zero_bit(free_i->free_secmap,
1626 							MAIN_SECS(sbi), 0);
1627 			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
1628 		} else {
1629 			go_left = 1;
1630 			left_start = hint - 1;
1631 		}
1632 	}
1633 	if (go_left == 0)
1634 		goto skip_left;
1635 
1636 	while (test_bit(left_start, free_i->free_secmap)) {
1637 		if (left_start > 0) {
1638 			left_start--;
1639 			continue;
1640 		}
1641 		left_start = find_next_zero_bit(free_i->free_secmap,
1642 							MAIN_SECS(sbi), 0);
1643 		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
1644 		break;
1645 	}
1646 	secno = left_start;
1647 skip_left:
1648 	hint = secno;
1649 	segno = GET_SEG_FROM_SEC(sbi, secno);
1650 	zoneno = GET_ZONE_FROM_SEC(sbi, secno);
1651 
1652 	/* give up on finding another zone */
1653 	if (!init)
1654 		goto got_it;
1655 	if (sbi->secs_per_zone == 1)
1656 		goto got_it;
1657 	if (zoneno == old_zoneno)
1658 		goto got_it;
1659 	if (dir == ALLOC_LEFT) {
1660 		if (!go_left && zoneno + 1 >= total_zones)
1661 			goto got_it;
1662 		if (go_left && zoneno == 0)
1663 			goto got_it;
1664 	}
1665 	for (i = 0; i < NR_CURSEG_TYPE; i++)
1666 		if (CURSEG_I(sbi, i)->zone == zoneno)
1667 			break;
1668 
1669 	if (i < NR_CURSEG_TYPE) {
1670 		/* zone is in user, try another */
1671 		if (go_left)
1672 			hint = zoneno * sbi->secs_per_zone - 1;
1673 		else if (zoneno + 1 >= total_zones)
1674 			hint = 0;
1675 		else
1676 			hint = (zoneno + 1) * sbi->secs_per_zone;
1677 		init = false;
1678 		goto find_other_zone;
1679 	}
1680 got_it:
1681 	/* set it as dirty segment in free segmap */
1682 	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
1683 	__set_inuse(sbi, segno);
1684 	*newseg = segno;
1685 	spin_unlock(&free_i->segmap_lock);
1686 }
1687 
1688 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
1689 {
1690 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1691 	struct summary_footer *sum_footer;
1692 
1693 	curseg->segno = curseg->next_segno;
1694 	curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
1695 	curseg->next_blkoff = 0;
1696 	curseg->next_segno = NULL_SEGNO;
1697 
1698 	sum_footer = &(curseg->sum_blk->footer);
1699 	memset(sum_footer, 0, sizeof(struct summary_footer));
1700 	if (IS_DATASEG(type))
1701 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
1702 	if (IS_NODESEG(type))
1703 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
1704 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
1705 }
1706 
1707 static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
1708 {
1709 	if (type == CURSEG_HOT_DATA || IS_NODESEG(type))
1710 		return 0;
1711 
1712 	return CURSEG_I(sbi, type)->segno;
1713 }
1714 
1715 /*
1716  * Allocate a current working segment.
1717  * This function always allocates a free segment in LFS manner.
1718  */
1719 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
1720 {
1721 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1722 	unsigned int segno = curseg->segno;
1723 	int dir = ALLOC_LEFT;
1724 
1725 	write_sum_page(sbi, curseg->sum_blk,
1726 				GET_SUM_BLOCK(sbi, segno));
1727 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
1728 		dir = ALLOC_RIGHT;
1729 
1730 	if (test_opt(sbi, NOHEAP))
1731 		dir = ALLOC_RIGHT;
1732 
1733 	segno = __get_next_segno(sbi, type);
1734 	get_new_segment(sbi, &segno, new_sec, dir);
1735 	curseg->next_segno = segno;
1736 	reset_curseg(sbi, type, 1);
1737 	curseg->alloc_type = LFS;
1738 }
1739 
1740 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
1741 			struct curseg_info *seg, block_t start)
1742 {
1743 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
1744 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1745 	unsigned long *target_map = SIT_I(sbi)->tmp_map;
1746 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1747 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1748 	int i, pos;
1749 
1750 	for (i = 0; i < entries; i++)
1751 		target_map[i] = ckpt_map[i] | cur_map[i];
1752 
1753 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
1754 
1755 	seg->next_blkoff = pos;
1756 }
1757 
1758 /*
1759  * If a segment is written by LFS manner, next block offset is just obtained
1760  * by increasing the current block offset. However, if a segment is written by
1761  * SSR manner, next block offset obtained by calling __next_free_blkoff
1762  */
1763 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
1764 				struct curseg_info *seg)
1765 {
1766 	if (seg->alloc_type == SSR)
1767 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
1768 	else
1769 		seg->next_blkoff++;
1770 }
1771 
1772 /*
1773  * This function always allocates a used segment(from dirty seglist) by SSR
1774  * manner, so it should recover the existing segment information of valid blocks
1775  */
1776 static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
1777 {
1778 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1779 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1780 	unsigned int new_segno = curseg->next_segno;
1781 	struct f2fs_summary_block *sum_node;
1782 	struct page *sum_page;
1783 
1784 	write_sum_page(sbi, curseg->sum_blk,
1785 				GET_SUM_BLOCK(sbi, curseg->segno));
1786 	__set_test_and_inuse(sbi, new_segno);
1787 
1788 	mutex_lock(&dirty_i->seglist_lock);
1789 	__remove_dirty_segment(sbi, new_segno, PRE);
1790 	__remove_dirty_segment(sbi, new_segno, DIRTY);
1791 	mutex_unlock(&dirty_i->seglist_lock);
1792 
1793 	reset_curseg(sbi, type, 1);
1794 	curseg->alloc_type = SSR;
1795 	__next_free_blkoff(sbi, curseg, 0);
1796 
1797 	if (reuse) {
1798 		sum_page = get_sum_page(sbi, new_segno);
1799 		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
1800 		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
1801 		f2fs_put_page(sum_page, 1);
1802 	}
1803 }
1804 
1805 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
1806 {
1807 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1808 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
1809 	int i, cnt;
1810 	bool reversed = false;
1811 
1812 	/* need_SSR() already forces to do this */
1813 	if (v_ops->get_victim(sbi, &(curseg)->next_segno, BG_GC, type, SSR))
1814 		return 1;
1815 
1816 	/* For node segments, let's do SSR more intensively */
1817 	if (IS_NODESEG(type)) {
1818 		if (type >= CURSEG_WARM_NODE) {
1819 			reversed = true;
1820 			i = CURSEG_COLD_NODE;
1821 		} else {
1822 			i = CURSEG_HOT_NODE;
1823 		}
1824 		cnt = NR_CURSEG_NODE_TYPE;
1825 	} else {
1826 		if (type >= CURSEG_WARM_DATA) {
1827 			reversed = true;
1828 			i = CURSEG_COLD_DATA;
1829 		} else {
1830 			i = CURSEG_HOT_DATA;
1831 		}
1832 		cnt = NR_CURSEG_DATA_TYPE;
1833 	}
1834 
1835 	for (; cnt-- > 0; reversed ? i-- : i++) {
1836 		if (i == type)
1837 			continue;
1838 		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
1839 						BG_GC, i, SSR))
1840 			return 1;
1841 	}
1842 	return 0;
1843 }
1844 
1845 /*
1846  * flush out current segment and replace it with new segment
1847  * This function should be returned with success, otherwise BUG
1848  */
1849 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
1850 						int type, bool force)
1851 {
1852 	if (force)
1853 		new_curseg(sbi, type, true);
1854 	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
1855 					type == CURSEG_WARM_NODE)
1856 		new_curseg(sbi, type, false);
1857 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
1858 		change_curseg(sbi, type, true);
1859 	else
1860 		new_curseg(sbi, type, false);
1861 
1862 	stat_inc_seg_type(sbi, CURSEG_I(sbi, type));
1863 }
1864 
1865 void allocate_new_segments(struct f2fs_sb_info *sbi)
1866 {
1867 	struct curseg_info *curseg;
1868 	unsigned int old_segno;
1869 	int i;
1870 
1871 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1872 		curseg = CURSEG_I(sbi, i);
1873 		old_segno = curseg->segno;
1874 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
1875 		locate_dirty_segment(sbi, old_segno);
1876 	}
1877 }
1878 
1879 static const struct segment_allocation default_salloc_ops = {
1880 	.allocate_segment = allocate_segment_by_default,
1881 };
1882 
1883 bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1884 {
1885 	__u64 trim_start = cpc->trim_start;
1886 	bool has_candidate = false;
1887 
1888 	mutex_lock(&SIT_I(sbi)->sentry_lock);
1889 	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
1890 		if (add_discard_addrs(sbi, cpc, true)) {
1891 			has_candidate = true;
1892 			break;
1893 		}
1894 	}
1895 	mutex_unlock(&SIT_I(sbi)->sentry_lock);
1896 
1897 	cpc->trim_start = trim_start;
1898 	return has_candidate;
1899 }
1900 
1901 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
1902 {
1903 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
1904 	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
1905 	unsigned int start_segno, end_segno;
1906 	struct cp_control cpc;
1907 	int err = 0;
1908 
1909 	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
1910 		return -EINVAL;
1911 
1912 	cpc.trimmed = 0;
1913 	if (end <= MAIN_BLKADDR(sbi))
1914 		goto out;
1915 
1916 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1917 		f2fs_msg(sbi->sb, KERN_WARNING,
1918 			"Found FS corruption, run fsck to fix.");
1919 		goto out;
1920 	}
1921 
1922 	/* start/end segment number in main_area */
1923 	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
1924 	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
1925 						GET_SEGNO(sbi, end);
1926 	cpc.reason = CP_DISCARD;
1927 	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
1928 
1929 	/* do checkpoint to issue discard commands safely */
1930 	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
1931 		cpc.trim_start = start_segno;
1932 
1933 		if (sbi->discard_blks == 0)
1934 			break;
1935 		else if (sbi->discard_blks < BATCHED_TRIM_BLOCKS(sbi))
1936 			cpc.trim_end = end_segno;
1937 		else
1938 			cpc.trim_end = min_t(unsigned int,
1939 				rounddown(start_segno +
1940 				BATCHED_TRIM_SEGMENTS(sbi),
1941 				sbi->segs_per_sec) - 1, end_segno);
1942 
1943 		mutex_lock(&sbi->gc_mutex);
1944 		err = write_checkpoint(sbi, &cpc);
1945 		mutex_unlock(&sbi->gc_mutex);
1946 		if (err)
1947 			break;
1948 
1949 		schedule();
1950 	}
1951 out:
1952 	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
1953 	return err;
1954 }
1955 
1956 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
1957 {
1958 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1959 	if (curseg->next_blkoff < sbi->blocks_per_seg)
1960 		return true;
1961 	return false;
1962 }
1963 
1964 static int __get_segment_type_2(struct page *page, enum page_type p_type)
1965 {
1966 	if (p_type == DATA)
1967 		return CURSEG_HOT_DATA;
1968 	else
1969 		return CURSEG_HOT_NODE;
1970 }
1971 
1972 static int __get_segment_type_4(struct page *page, enum page_type p_type)
1973 {
1974 	if (p_type == DATA) {
1975 		struct inode *inode = page->mapping->host;
1976 
1977 		if (S_ISDIR(inode->i_mode))
1978 			return CURSEG_HOT_DATA;
1979 		else
1980 			return CURSEG_COLD_DATA;
1981 	} else {
1982 		if (IS_DNODE(page) && is_cold_node(page))
1983 			return CURSEG_WARM_NODE;
1984 		else
1985 			return CURSEG_COLD_NODE;
1986 	}
1987 }
1988 
1989 static int __get_segment_type_6(struct page *page, enum page_type p_type)
1990 {
1991 	if (p_type == DATA) {
1992 		struct inode *inode = page->mapping->host;
1993 
1994 		if (is_cold_data(page) || file_is_cold(inode))
1995 			return CURSEG_COLD_DATA;
1996 		if (is_inode_flag_set(inode, FI_HOT_DATA))
1997 			return CURSEG_HOT_DATA;
1998 		return CURSEG_WARM_DATA;
1999 	} else {
2000 		if (IS_DNODE(page))
2001 			return is_cold_node(page) ? CURSEG_WARM_NODE :
2002 						CURSEG_HOT_NODE;
2003 		return CURSEG_COLD_NODE;
2004 	}
2005 }
2006 
2007 static int __get_segment_type(struct page *page, enum page_type p_type)
2008 {
2009 	switch (F2FS_P_SB(page)->active_logs) {
2010 	case 2:
2011 		return __get_segment_type_2(page, p_type);
2012 	case 4:
2013 		return __get_segment_type_4(page, p_type);
2014 	}
2015 	/* NR_CURSEG_TYPE(6) logs by default */
2016 	f2fs_bug_on(F2FS_P_SB(page),
2017 		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
2018 	return __get_segment_type_6(page, p_type);
2019 }
2020 
2021 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
2022 		block_t old_blkaddr, block_t *new_blkaddr,
2023 		struct f2fs_summary *sum, int type)
2024 {
2025 	struct sit_info *sit_i = SIT_I(sbi);
2026 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2027 
2028 	mutex_lock(&curseg->curseg_mutex);
2029 	mutex_lock(&sit_i->sentry_lock);
2030 
2031 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
2032 
2033 	f2fs_wait_discard_bio(sbi, *new_blkaddr);
2034 
2035 	/*
2036 	 * __add_sum_entry should be resided under the curseg_mutex
2037 	 * because, this function updates a summary entry in the
2038 	 * current summary block.
2039 	 */
2040 	__add_sum_entry(sbi, type, sum);
2041 
2042 	__refresh_next_blkoff(sbi, curseg);
2043 
2044 	stat_inc_block_count(sbi, curseg);
2045 
2046 	if (!__has_curseg_space(sbi, type))
2047 		sit_i->s_ops->allocate_segment(sbi, type, false);
2048 	/*
2049 	 * SIT information should be updated after segment allocation,
2050 	 * since we need to keep dirty segments precisely under SSR.
2051 	 */
2052 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
2053 
2054 	mutex_unlock(&sit_i->sentry_lock);
2055 
2056 	if (page && IS_NODESEG(type))
2057 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
2058 
2059 	mutex_unlock(&curseg->curseg_mutex);
2060 }
2061 
2062 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
2063 {
2064 	int type = __get_segment_type(fio->page, fio->type);
2065 	int err;
2066 
2067 	if (fio->type == NODE || fio->type == DATA)
2068 		mutex_lock(&fio->sbi->wio_mutex[fio->type]);
2069 reallocate:
2070 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
2071 					&fio->new_blkaddr, sum, type);
2072 
2073 	/* writeout dirty page into bdev */
2074 	err = f2fs_submit_page_mbio(fio);
2075 	if (err == -EAGAIN) {
2076 		fio->old_blkaddr = fio->new_blkaddr;
2077 		goto reallocate;
2078 	}
2079 
2080 	if (fio->type == NODE || fio->type == DATA)
2081 		mutex_unlock(&fio->sbi->wio_mutex[fio->type]);
2082 }
2083 
2084 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
2085 {
2086 	struct f2fs_io_info fio = {
2087 		.sbi = sbi,
2088 		.type = META,
2089 		.op = REQ_OP_WRITE,
2090 		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
2091 		.old_blkaddr = page->index,
2092 		.new_blkaddr = page->index,
2093 		.page = page,
2094 		.encrypted_page = NULL,
2095 	};
2096 
2097 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
2098 		fio.op_flags &= ~REQ_META;
2099 
2100 	set_page_writeback(page);
2101 	f2fs_submit_page_mbio(&fio);
2102 }
2103 
2104 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
2105 {
2106 	struct f2fs_summary sum;
2107 
2108 	set_summary(&sum, nid, 0, 0);
2109 	do_write_page(&sum, fio);
2110 }
2111 
2112 void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
2113 {
2114 	struct f2fs_sb_info *sbi = fio->sbi;
2115 	struct f2fs_summary sum;
2116 	struct node_info ni;
2117 
2118 	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
2119 	get_node_info(sbi, dn->nid, &ni);
2120 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
2121 	do_write_page(&sum, fio);
2122 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
2123 }
2124 
2125 int rewrite_data_page(struct f2fs_io_info *fio)
2126 {
2127 	fio->new_blkaddr = fio->old_blkaddr;
2128 	stat_inc_inplace_blocks(fio->sbi);
2129 	return f2fs_submit_page_bio(fio);
2130 }
2131 
2132 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
2133 				block_t old_blkaddr, block_t new_blkaddr,
2134 				bool recover_curseg, bool recover_newaddr)
2135 {
2136 	struct sit_info *sit_i = SIT_I(sbi);
2137 	struct curseg_info *curseg;
2138 	unsigned int segno, old_cursegno;
2139 	struct seg_entry *se;
2140 	int type;
2141 	unsigned short old_blkoff;
2142 
2143 	segno = GET_SEGNO(sbi, new_blkaddr);
2144 	se = get_seg_entry(sbi, segno);
2145 	type = se->type;
2146 
2147 	if (!recover_curseg) {
2148 		/* for recovery flow */
2149 		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
2150 			if (old_blkaddr == NULL_ADDR)
2151 				type = CURSEG_COLD_DATA;
2152 			else
2153 				type = CURSEG_WARM_DATA;
2154 		}
2155 	} else {
2156 		if (!IS_CURSEG(sbi, segno))
2157 			type = CURSEG_WARM_DATA;
2158 	}
2159 
2160 	curseg = CURSEG_I(sbi, type);
2161 
2162 	mutex_lock(&curseg->curseg_mutex);
2163 	mutex_lock(&sit_i->sentry_lock);
2164 
2165 	old_cursegno = curseg->segno;
2166 	old_blkoff = curseg->next_blkoff;
2167 
2168 	/* change the current segment */
2169 	if (segno != curseg->segno) {
2170 		curseg->next_segno = segno;
2171 		change_curseg(sbi, type, true);
2172 	}
2173 
2174 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
2175 	__add_sum_entry(sbi, type, sum);
2176 
2177 	if (!recover_curseg || recover_newaddr)
2178 		update_sit_entry(sbi, new_blkaddr, 1);
2179 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
2180 		update_sit_entry(sbi, old_blkaddr, -1);
2181 
2182 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
2183 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
2184 
2185 	locate_dirty_segment(sbi, old_cursegno);
2186 
2187 	if (recover_curseg) {
2188 		if (old_cursegno != curseg->segno) {
2189 			curseg->next_segno = old_cursegno;
2190 			change_curseg(sbi, type, true);
2191 		}
2192 		curseg->next_blkoff = old_blkoff;
2193 	}
2194 
2195 	mutex_unlock(&sit_i->sentry_lock);
2196 	mutex_unlock(&curseg->curseg_mutex);
2197 }
2198 
2199 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
2200 				block_t old_addr, block_t new_addr,
2201 				unsigned char version, bool recover_curseg,
2202 				bool recover_newaddr)
2203 {
2204 	struct f2fs_summary sum;
2205 
2206 	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
2207 
2208 	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
2209 					recover_curseg, recover_newaddr);
2210 
2211 	f2fs_update_data_blkaddr(dn, new_addr);
2212 }
2213 
2214 void f2fs_wait_on_page_writeback(struct page *page,
2215 				enum page_type type, bool ordered)
2216 {
2217 	if (PageWriteback(page)) {
2218 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
2219 
2220 		f2fs_submit_merged_bio_cond(sbi, page->mapping->host,
2221 						0, page->index, type, WRITE);
2222 		if (ordered)
2223 			wait_on_page_writeback(page);
2224 		else
2225 			wait_for_stable_page(page);
2226 	}
2227 }
2228 
2229 void f2fs_wait_on_encrypted_page_writeback(struct f2fs_sb_info *sbi,
2230 							block_t blkaddr)
2231 {
2232 	struct page *cpage;
2233 
2234 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
2235 		return;
2236 
2237 	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
2238 	if (cpage) {
2239 		f2fs_wait_on_page_writeback(cpage, DATA, true);
2240 		f2fs_put_page(cpage, 1);
2241 	}
2242 }
2243 
2244 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
2245 {
2246 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2247 	struct curseg_info *seg_i;
2248 	unsigned char *kaddr;
2249 	struct page *page;
2250 	block_t start;
2251 	int i, j, offset;
2252 
2253 	start = start_sum_block(sbi);
2254 
2255 	page = get_meta_page(sbi, start++);
2256 	kaddr = (unsigned char *)page_address(page);
2257 
2258 	/* Step 1: restore nat cache */
2259 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2260 	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
2261 
2262 	/* Step 2: restore sit cache */
2263 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2264 	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
2265 	offset = 2 * SUM_JOURNAL_SIZE;
2266 
2267 	/* Step 3: restore summary entries */
2268 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2269 		unsigned short blk_off;
2270 		unsigned int segno;
2271 
2272 		seg_i = CURSEG_I(sbi, i);
2273 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
2274 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
2275 		seg_i->next_segno = segno;
2276 		reset_curseg(sbi, i, 0);
2277 		seg_i->alloc_type = ckpt->alloc_type[i];
2278 		seg_i->next_blkoff = blk_off;
2279 
2280 		if (seg_i->alloc_type == SSR)
2281 			blk_off = sbi->blocks_per_seg;
2282 
2283 		for (j = 0; j < blk_off; j++) {
2284 			struct f2fs_summary *s;
2285 			s = (struct f2fs_summary *)(kaddr + offset);
2286 			seg_i->sum_blk->entries[j] = *s;
2287 			offset += SUMMARY_SIZE;
2288 			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
2289 						SUM_FOOTER_SIZE)
2290 				continue;
2291 
2292 			f2fs_put_page(page, 1);
2293 			page = NULL;
2294 
2295 			page = get_meta_page(sbi, start++);
2296 			kaddr = (unsigned char *)page_address(page);
2297 			offset = 0;
2298 		}
2299 	}
2300 	f2fs_put_page(page, 1);
2301 	return 0;
2302 }
2303 
2304 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
2305 {
2306 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2307 	struct f2fs_summary_block *sum;
2308 	struct curseg_info *curseg;
2309 	struct page *new;
2310 	unsigned short blk_off;
2311 	unsigned int segno = 0;
2312 	block_t blk_addr = 0;
2313 
2314 	/* get segment number and block addr */
2315 	if (IS_DATASEG(type)) {
2316 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
2317 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
2318 							CURSEG_HOT_DATA]);
2319 		if (__exist_node_summaries(sbi))
2320 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
2321 		else
2322 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
2323 	} else {
2324 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
2325 							CURSEG_HOT_NODE]);
2326 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
2327 							CURSEG_HOT_NODE]);
2328 		if (__exist_node_summaries(sbi))
2329 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
2330 							type - CURSEG_HOT_NODE);
2331 		else
2332 			blk_addr = GET_SUM_BLOCK(sbi, segno);
2333 	}
2334 
2335 	new = get_meta_page(sbi, blk_addr);
2336 	sum = (struct f2fs_summary_block *)page_address(new);
2337 
2338 	if (IS_NODESEG(type)) {
2339 		if (__exist_node_summaries(sbi)) {
2340 			struct f2fs_summary *ns = &sum->entries[0];
2341 			int i;
2342 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
2343 				ns->version = 0;
2344 				ns->ofs_in_node = 0;
2345 			}
2346 		} else {
2347 			int err;
2348 
2349 			err = restore_node_summary(sbi, segno, sum);
2350 			if (err) {
2351 				f2fs_put_page(new, 1);
2352 				return err;
2353 			}
2354 		}
2355 	}
2356 
2357 	/* set uncompleted segment to curseg */
2358 	curseg = CURSEG_I(sbi, type);
2359 	mutex_lock(&curseg->curseg_mutex);
2360 
2361 	/* update journal info */
2362 	down_write(&curseg->journal_rwsem);
2363 	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
2364 	up_write(&curseg->journal_rwsem);
2365 
2366 	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
2367 	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
2368 	curseg->next_segno = segno;
2369 	reset_curseg(sbi, type, 0);
2370 	curseg->alloc_type = ckpt->alloc_type[type];
2371 	curseg->next_blkoff = blk_off;
2372 	mutex_unlock(&curseg->curseg_mutex);
2373 	f2fs_put_page(new, 1);
2374 	return 0;
2375 }
2376 
2377 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
2378 {
2379 	int type = CURSEG_HOT_DATA;
2380 	int err;
2381 
2382 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
2383 		int npages = npages_for_summary_flush(sbi, true);
2384 
2385 		if (npages >= 2)
2386 			ra_meta_pages(sbi, start_sum_block(sbi), npages,
2387 							META_CP, true);
2388 
2389 		/* restore for compacted data summary */
2390 		if (read_compacted_summaries(sbi))
2391 			return -EINVAL;
2392 		type = CURSEG_HOT_NODE;
2393 	}
2394 
2395 	if (__exist_node_summaries(sbi))
2396 		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
2397 					NR_CURSEG_TYPE - type, META_CP, true);
2398 
2399 	for (; type <= CURSEG_COLD_NODE; type++) {
2400 		err = read_normal_summaries(sbi, type);
2401 		if (err)
2402 			return err;
2403 	}
2404 
2405 	return 0;
2406 }
2407 
2408 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
2409 {
2410 	struct page *page;
2411 	unsigned char *kaddr;
2412 	struct f2fs_summary *summary;
2413 	struct curseg_info *seg_i;
2414 	int written_size = 0;
2415 	int i, j;
2416 
2417 	page = grab_meta_page(sbi, blkaddr++);
2418 	kaddr = (unsigned char *)page_address(page);
2419 
2420 	/* Step 1: write nat cache */
2421 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2422 	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
2423 	written_size += SUM_JOURNAL_SIZE;
2424 
2425 	/* Step 2: write sit cache */
2426 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2427 	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
2428 	written_size += SUM_JOURNAL_SIZE;
2429 
2430 	/* Step 3: write summary entries */
2431 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2432 		unsigned short blkoff;
2433 		seg_i = CURSEG_I(sbi, i);
2434 		if (sbi->ckpt->alloc_type[i] == SSR)
2435 			blkoff = sbi->blocks_per_seg;
2436 		else
2437 			blkoff = curseg_blkoff(sbi, i);
2438 
2439 		for (j = 0; j < blkoff; j++) {
2440 			if (!page) {
2441 				page = grab_meta_page(sbi, blkaddr++);
2442 				kaddr = (unsigned char *)page_address(page);
2443 				written_size = 0;
2444 			}
2445 			summary = (struct f2fs_summary *)(kaddr + written_size);
2446 			*summary = seg_i->sum_blk->entries[j];
2447 			written_size += SUMMARY_SIZE;
2448 
2449 			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
2450 							SUM_FOOTER_SIZE)
2451 				continue;
2452 
2453 			set_page_dirty(page);
2454 			f2fs_put_page(page, 1);
2455 			page = NULL;
2456 		}
2457 	}
2458 	if (page) {
2459 		set_page_dirty(page);
2460 		f2fs_put_page(page, 1);
2461 	}
2462 }
2463 
2464 static void write_normal_summaries(struct f2fs_sb_info *sbi,
2465 					block_t blkaddr, int type)
2466 {
2467 	int i, end;
2468 	if (IS_DATASEG(type))
2469 		end = type + NR_CURSEG_DATA_TYPE;
2470 	else
2471 		end = type + NR_CURSEG_NODE_TYPE;
2472 
2473 	for (i = type; i < end; i++)
2474 		write_current_sum_page(sbi, i, blkaddr + (i - type));
2475 }
2476 
2477 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2478 {
2479 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
2480 		write_compacted_summaries(sbi, start_blk);
2481 	else
2482 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
2483 }
2484 
2485 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2486 {
2487 	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
2488 }
2489 
2490 int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
2491 					unsigned int val, int alloc)
2492 {
2493 	int i;
2494 
2495 	if (type == NAT_JOURNAL) {
2496 		for (i = 0; i < nats_in_cursum(journal); i++) {
2497 			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
2498 				return i;
2499 		}
2500 		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
2501 			return update_nats_in_cursum(journal, 1);
2502 	} else if (type == SIT_JOURNAL) {
2503 		for (i = 0; i < sits_in_cursum(journal); i++)
2504 			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
2505 				return i;
2506 		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
2507 			return update_sits_in_cursum(journal, 1);
2508 	}
2509 	return -1;
2510 }
2511 
2512 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
2513 					unsigned int segno)
2514 {
2515 	return get_meta_page(sbi, current_sit_addr(sbi, segno));
2516 }
2517 
2518 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
2519 					unsigned int start)
2520 {
2521 	struct sit_info *sit_i = SIT_I(sbi);
2522 	struct page *src_page, *dst_page;
2523 	pgoff_t src_off, dst_off;
2524 	void *src_addr, *dst_addr;
2525 
2526 	src_off = current_sit_addr(sbi, start);
2527 	dst_off = next_sit_addr(sbi, src_off);
2528 
2529 	/* get current sit block page without lock */
2530 	src_page = get_meta_page(sbi, src_off);
2531 	dst_page = grab_meta_page(sbi, dst_off);
2532 	f2fs_bug_on(sbi, PageDirty(src_page));
2533 
2534 	src_addr = page_address(src_page);
2535 	dst_addr = page_address(dst_page);
2536 	memcpy(dst_addr, src_addr, PAGE_SIZE);
2537 
2538 	set_page_dirty(dst_page);
2539 	f2fs_put_page(src_page, 1);
2540 
2541 	set_to_next_sit(sit_i, start);
2542 
2543 	return dst_page;
2544 }
2545 
2546 static struct sit_entry_set *grab_sit_entry_set(void)
2547 {
2548 	struct sit_entry_set *ses =
2549 			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
2550 
2551 	ses->entry_cnt = 0;
2552 	INIT_LIST_HEAD(&ses->set_list);
2553 	return ses;
2554 }
2555 
2556 static void release_sit_entry_set(struct sit_entry_set *ses)
2557 {
2558 	list_del(&ses->set_list);
2559 	kmem_cache_free(sit_entry_set_slab, ses);
2560 }
2561 
2562 static void adjust_sit_entry_set(struct sit_entry_set *ses,
2563 						struct list_head *head)
2564 {
2565 	struct sit_entry_set *next = ses;
2566 
2567 	if (list_is_last(&ses->set_list, head))
2568 		return;
2569 
2570 	list_for_each_entry_continue(next, head, set_list)
2571 		if (ses->entry_cnt <= next->entry_cnt)
2572 			break;
2573 
2574 	list_move_tail(&ses->set_list, &next->set_list);
2575 }
2576 
2577 static void add_sit_entry(unsigned int segno, struct list_head *head)
2578 {
2579 	struct sit_entry_set *ses;
2580 	unsigned int start_segno = START_SEGNO(segno);
2581 
2582 	list_for_each_entry(ses, head, set_list) {
2583 		if (ses->start_segno == start_segno) {
2584 			ses->entry_cnt++;
2585 			adjust_sit_entry_set(ses, head);
2586 			return;
2587 		}
2588 	}
2589 
2590 	ses = grab_sit_entry_set();
2591 
2592 	ses->start_segno = start_segno;
2593 	ses->entry_cnt++;
2594 	list_add(&ses->set_list, head);
2595 }
2596 
2597 static void add_sits_in_set(struct f2fs_sb_info *sbi)
2598 {
2599 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2600 	struct list_head *set_list = &sm_info->sit_entry_set;
2601 	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
2602 	unsigned int segno;
2603 
2604 	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
2605 		add_sit_entry(segno, set_list);
2606 }
2607 
2608 static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
2609 {
2610 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2611 	struct f2fs_journal *journal = curseg->journal;
2612 	int i;
2613 
2614 	down_write(&curseg->journal_rwsem);
2615 	for (i = 0; i < sits_in_cursum(journal); i++) {
2616 		unsigned int segno;
2617 		bool dirtied;
2618 
2619 		segno = le32_to_cpu(segno_in_journal(journal, i));
2620 		dirtied = __mark_sit_entry_dirty(sbi, segno);
2621 
2622 		if (!dirtied)
2623 			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
2624 	}
2625 	update_sits_in_cursum(journal, -i);
2626 	up_write(&curseg->journal_rwsem);
2627 }
2628 
2629 /*
2630  * CP calls this function, which flushes SIT entries including sit_journal,
2631  * and moves prefree segs to free segs.
2632  */
2633 void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
2634 {
2635 	struct sit_info *sit_i = SIT_I(sbi);
2636 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
2637 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2638 	struct f2fs_journal *journal = curseg->journal;
2639 	struct sit_entry_set *ses, *tmp;
2640 	struct list_head *head = &SM_I(sbi)->sit_entry_set;
2641 	bool to_journal = true;
2642 	struct seg_entry *se;
2643 
2644 	mutex_lock(&sit_i->sentry_lock);
2645 
2646 	if (!sit_i->dirty_sentries)
2647 		goto out;
2648 
2649 	/*
2650 	 * add and account sit entries of dirty bitmap in sit entry
2651 	 * set temporarily
2652 	 */
2653 	add_sits_in_set(sbi);
2654 
2655 	/*
2656 	 * if there are no enough space in journal to store dirty sit
2657 	 * entries, remove all entries from journal and add and account
2658 	 * them in sit entry set.
2659 	 */
2660 	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
2661 		remove_sits_in_journal(sbi);
2662 
2663 	/*
2664 	 * there are two steps to flush sit entries:
2665 	 * #1, flush sit entries to journal in current cold data summary block.
2666 	 * #2, flush sit entries to sit page.
2667 	 */
2668 	list_for_each_entry_safe(ses, tmp, head, set_list) {
2669 		struct page *page = NULL;
2670 		struct f2fs_sit_block *raw_sit = NULL;
2671 		unsigned int start_segno = ses->start_segno;
2672 		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
2673 						(unsigned long)MAIN_SEGS(sbi));
2674 		unsigned int segno = start_segno;
2675 
2676 		if (to_journal &&
2677 			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
2678 			to_journal = false;
2679 
2680 		if (to_journal) {
2681 			down_write(&curseg->journal_rwsem);
2682 		} else {
2683 			page = get_next_sit_page(sbi, start_segno);
2684 			raw_sit = page_address(page);
2685 		}
2686 
2687 		/* flush dirty sit entries in region of current sit set */
2688 		for_each_set_bit_from(segno, bitmap, end) {
2689 			int offset, sit_offset;
2690 
2691 			se = get_seg_entry(sbi, segno);
2692 
2693 			/* add discard candidates */
2694 			if (cpc->reason != CP_DISCARD) {
2695 				cpc->trim_start = segno;
2696 				add_discard_addrs(sbi, cpc, false);
2697 			}
2698 
2699 			if (to_journal) {
2700 				offset = lookup_journal_in_cursum(journal,
2701 							SIT_JOURNAL, segno, 1);
2702 				f2fs_bug_on(sbi, offset < 0);
2703 				segno_in_journal(journal, offset) =
2704 							cpu_to_le32(segno);
2705 				seg_info_to_raw_sit(se,
2706 					&sit_in_journal(journal, offset));
2707 			} else {
2708 				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
2709 				seg_info_to_raw_sit(se,
2710 						&raw_sit->entries[sit_offset]);
2711 			}
2712 
2713 			__clear_bit(segno, bitmap);
2714 			sit_i->dirty_sentries--;
2715 			ses->entry_cnt--;
2716 		}
2717 
2718 		if (to_journal)
2719 			up_write(&curseg->journal_rwsem);
2720 		else
2721 			f2fs_put_page(page, 1);
2722 
2723 		f2fs_bug_on(sbi, ses->entry_cnt);
2724 		release_sit_entry_set(ses);
2725 	}
2726 
2727 	f2fs_bug_on(sbi, !list_empty(head));
2728 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
2729 out:
2730 	if (cpc->reason == CP_DISCARD) {
2731 		__u64 trim_start = cpc->trim_start;
2732 
2733 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
2734 			add_discard_addrs(sbi, cpc, false);
2735 
2736 		cpc->trim_start = trim_start;
2737 	}
2738 	mutex_unlock(&sit_i->sentry_lock);
2739 
2740 	set_prefree_as_free_segments(sbi);
2741 }
2742 
2743 static int build_sit_info(struct f2fs_sb_info *sbi)
2744 {
2745 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2746 	struct sit_info *sit_i;
2747 	unsigned int sit_segs, start;
2748 	char *src_bitmap;
2749 	unsigned int bitmap_size;
2750 
2751 	/* allocate memory for SIT information */
2752 	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
2753 	if (!sit_i)
2754 		return -ENOMEM;
2755 
2756 	SM_I(sbi)->sit_info = sit_i;
2757 
2758 	sit_i->sentries = f2fs_kvzalloc(MAIN_SEGS(sbi) *
2759 					sizeof(struct seg_entry), GFP_KERNEL);
2760 	if (!sit_i->sentries)
2761 		return -ENOMEM;
2762 
2763 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2764 	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2765 	if (!sit_i->dirty_sentries_bitmap)
2766 		return -ENOMEM;
2767 
2768 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2769 		sit_i->sentries[start].cur_valid_map
2770 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2771 		sit_i->sentries[start].ckpt_valid_map
2772 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2773 		if (!sit_i->sentries[start].cur_valid_map ||
2774 				!sit_i->sentries[start].ckpt_valid_map)
2775 			return -ENOMEM;
2776 
2777 #ifdef CONFIG_F2FS_CHECK_FS
2778 		sit_i->sentries[start].cur_valid_map_mir
2779 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2780 		if (!sit_i->sentries[start].cur_valid_map_mir)
2781 			return -ENOMEM;
2782 #endif
2783 
2784 		if (f2fs_discard_en(sbi)) {
2785 			sit_i->sentries[start].discard_map
2786 				= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2787 			if (!sit_i->sentries[start].discard_map)
2788 				return -ENOMEM;
2789 		}
2790 	}
2791 
2792 	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2793 	if (!sit_i->tmp_map)
2794 		return -ENOMEM;
2795 
2796 	if (sbi->segs_per_sec > 1) {
2797 		sit_i->sec_entries = f2fs_kvzalloc(MAIN_SECS(sbi) *
2798 					sizeof(struct sec_entry), GFP_KERNEL);
2799 		if (!sit_i->sec_entries)
2800 			return -ENOMEM;
2801 	}
2802 
2803 	/* get information related with SIT */
2804 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
2805 
2806 	/* setup SIT bitmap from ckeckpoint pack */
2807 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
2808 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
2809 
2810 	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2811 	if (!sit_i->sit_bitmap)
2812 		return -ENOMEM;
2813 
2814 #ifdef CONFIG_F2FS_CHECK_FS
2815 	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2816 	if (!sit_i->sit_bitmap_mir)
2817 		return -ENOMEM;
2818 #endif
2819 
2820 	/* init SIT information */
2821 	sit_i->s_ops = &default_salloc_ops;
2822 
2823 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
2824 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
2825 	sit_i->written_valid_blocks = 0;
2826 	sit_i->bitmap_size = bitmap_size;
2827 	sit_i->dirty_sentries = 0;
2828 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
2829 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
2830 	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
2831 	mutex_init(&sit_i->sentry_lock);
2832 	return 0;
2833 }
2834 
2835 static int build_free_segmap(struct f2fs_sb_info *sbi)
2836 {
2837 	struct free_segmap_info *free_i;
2838 	unsigned int bitmap_size, sec_bitmap_size;
2839 
2840 	/* allocate memory for free segmap information */
2841 	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
2842 	if (!free_i)
2843 		return -ENOMEM;
2844 
2845 	SM_I(sbi)->free_info = free_i;
2846 
2847 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2848 	free_i->free_segmap = f2fs_kvmalloc(bitmap_size, GFP_KERNEL);
2849 	if (!free_i->free_segmap)
2850 		return -ENOMEM;
2851 
2852 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2853 	free_i->free_secmap = f2fs_kvmalloc(sec_bitmap_size, GFP_KERNEL);
2854 	if (!free_i->free_secmap)
2855 		return -ENOMEM;
2856 
2857 	/* set all segments as dirty temporarily */
2858 	memset(free_i->free_segmap, 0xff, bitmap_size);
2859 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
2860 
2861 	/* init free segmap information */
2862 	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
2863 	free_i->free_segments = 0;
2864 	free_i->free_sections = 0;
2865 	spin_lock_init(&free_i->segmap_lock);
2866 	return 0;
2867 }
2868 
2869 static int build_curseg(struct f2fs_sb_info *sbi)
2870 {
2871 	struct curseg_info *array;
2872 	int i;
2873 
2874 	array = kcalloc(NR_CURSEG_TYPE, sizeof(*array), GFP_KERNEL);
2875 	if (!array)
2876 		return -ENOMEM;
2877 
2878 	SM_I(sbi)->curseg_array = array;
2879 
2880 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2881 		mutex_init(&array[i].curseg_mutex);
2882 		array[i].sum_blk = kzalloc(PAGE_SIZE, GFP_KERNEL);
2883 		if (!array[i].sum_blk)
2884 			return -ENOMEM;
2885 		init_rwsem(&array[i].journal_rwsem);
2886 		array[i].journal = kzalloc(sizeof(struct f2fs_journal),
2887 							GFP_KERNEL);
2888 		if (!array[i].journal)
2889 			return -ENOMEM;
2890 		array[i].segno = NULL_SEGNO;
2891 		array[i].next_blkoff = 0;
2892 	}
2893 	return restore_curseg_summaries(sbi);
2894 }
2895 
2896 static void build_sit_entries(struct f2fs_sb_info *sbi)
2897 {
2898 	struct sit_info *sit_i = SIT_I(sbi);
2899 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2900 	struct f2fs_journal *journal = curseg->journal;
2901 	struct seg_entry *se;
2902 	struct f2fs_sit_entry sit;
2903 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
2904 	unsigned int i, start, end;
2905 	unsigned int readed, start_blk = 0;
2906 
2907 	do {
2908 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
2909 							META_SIT, true);
2910 
2911 		start = start_blk * sit_i->sents_per_block;
2912 		end = (start_blk + readed) * sit_i->sents_per_block;
2913 
2914 		for (; start < end && start < MAIN_SEGS(sbi); start++) {
2915 			struct f2fs_sit_block *sit_blk;
2916 			struct page *page;
2917 
2918 			se = &sit_i->sentries[start];
2919 			page = get_current_sit_page(sbi, start);
2920 			sit_blk = (struct f2fs_sit_block *)page_address(page);
2921 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
2922 			f2fs_put_page(page, 1);
2923 
2924 			check_block_count(sbi, start, &sit);
2925 			seg_info_from_raw_sit(se, &sit);
2926 
2927 			/* build discard map only one time */
2928 			if (f2fs_discard_en(sbi)) {
2929 				memcpy(se->discard_map, se->cur_valid_map,
2930 							SIT_VBLOCK_MAP_SIZE);
2931 				sbi->discard_blks += sbi->blocks_per_seg -
2932 							se->valid_blocks;
2933 			}
2934 
2935 			if (sbi->segs_per_sec > 1)
2936 				get_sec_entry(sbi, start)->valid_blocks +=
2937 							se->valid_blocks;
2938 		}
2939 		start_blk += readed;
2940 	} while (start_blk < sit_blk_cnt);
2941 
2942 	down_read(&curseg->journal_rwsem);
2943 	for (i = 0; i < sits_in_cursum(journal); i++) {
2944 		unsigned int old_valid_blocks;
2945 
2946 		start = le32_to_cpu(segno_in_journal(journal, i));
2947 		se = &sit_i->sentries[start];
2948 		sit = sit_in_journal(journal, i);
2949 
2950 		old_valid_blocks = se->valid_blocks;
2951 
2952 		check_block_count(sbi, start, &sit);
2953 		seg_info_from_raw_sit(se, &sit);
2954 
2955 		if (f2fs_discard_en(sbi)) {
2956 			memcpy(se->discard_map, se->cur_valid_map,
2957 						SIT_VBLOCK_MAP_SIZE);
2958 			sbi->discard_blks += old_valid_blocks -
2959 						se->valid_blocks;
2960 		}
2961 
2962 		if (sbi->segs_per_sec > 1)
2963 			get_sec_entry(sbi, start)->valid_blocks +=
2964 				se->valid_blocks - old_valid_blocks;
2965 	}
2966 	up_read(&curseg->journal_rwsem);
2967 }
2968 
2969 static void init_free_segmap(struct f2fs_sb_info *sbi)
2970 {
2971 	unsigned int start;
2972 	int type;
2973 
2974 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2975 		struct seg_entry *sentry = get_seg_entry(sbi, start);
2976 		if (!sentry->valid_blocks)
2977 			__set_free(sbi, start);
2978 		else
2979 			SIT_I(sbi)->written_valid_blocks +=
2980 						sentry->valid_blocks;
2981 	}
2982 
2983 	/* set use the current segments */
2984 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
2985 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
2986 		__set_test_and_inuse(sbi, curseg_t->segno);
2987 	}
2988 }
2989 
2990 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
2991 {
2992 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2993 	struct free_segmap_info *free_i = FREE_I(sbi);
2994 	unsigned int segno = 0, offset = 0;
2995 	unsigned short valid_blocks;
2996 
2997 	while (1) {
2998 		/* find dirty segment based on free segmap */
2999 		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
3000 		if (segno >= MAIN_SEGS(sbi))
3001 			break;
3002 		offset = segno + 1;
3003 		valid_blocks = get_valid_blocks(sbi, segno, false);
3004 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
3005 			continue;
3006 		if (valid_blocks > sbi->blocks_per_seg) {
3007 			f2fs_bug_on(sbi, 1);
3008 			continue;
3009 		}
3010 		mutex_lock(&dirty_i->seglist_lock);
3011 		__locate_dirty_segment(sbi, segno, DIRTY);
3012 		mutex_unlock(&dirty_i->seglist_lock);
3013 	}
3014 }
3015 
3016 static int init_victim_secmap(struct f2fs_sb_info *sbi)
3017 {
3018 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3019 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
3020 
3021 	dirty_i->victim_secmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
3022 	if (!dirty_i->victim_secmap)
3023 		return -ENOMEM;
3024 	return 0;
3025 }
3026 
3027 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
3028 {
3029 	struct dirty_seglist_info *dirty_i;
3030 	unsigned int bitmap_size, i;
3031 
3032 	/* allocate memory for dirty segments list information */
3033 	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
3034 	if (!dirty_i)
3035 		return -ENOMEM;
3036 
3037 	SM_I(sbi)->dirty_info = dirty_i;
3038 	mutex_init(&dirty_i->seglist_lock);
3039 
3040 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
3041 
3042 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
3043 		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
3044 		if (!dirty_i->dirty_segmap[i])
3045 			return -ENOMEM;
3046 	}
3047 
3048 	init_dirty_segmap(sbi);
3049 	return init_victim_secmap(sbi);
3050 }
3051 
3052 /*
3053  * Update min, max modified time for cost-benefit GC algorithm
3054  */
3055 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
3056 {
3057 	struct sit_info *sit_i = SIT_I(sbi);
3058 	unsigned int segno;
3059 
3060 	mutex_lock(&sit_i->sentry_lock);
3061 
3062 	sit_i->min_mtime = LLONG_MAX;
3063 
3064 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
3065 		unsigned int i;
3066 		unsigned long long mtime = 0;
3067 
3068 		for (i = 0; i < sbi->segs_per_sec; i++)
3069 			mtime += get_seg_entry(sbi, segno + i)->mtime;
3070 
3071 		mtime = div_u64(mtime, sbi->segs_per_sec);
3072 
3073 		if (sit_i->min_mtime > mtime)
3074 			sit_i->min_mtime = mtime;
3075 	}
3076 	sit_i->max_mtime = get_mtime(sbi);
3077 	mutex_unlock(&sit_i->sentry_lock);
3078 }
3079 
3080 int build_segment_manager(struct f2fs_sb_info *sbi)
3081 {
3082 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
3083 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
3084 	struct f2fs_sm_info *sm_info;
3085 	int err;
3086 
3087 	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
3088 	if (!sm_info)
3089 		return -ENOMEM;
3090 
3091 	/* init sm info */
3092 	sbi->sm_info = sm_info;
3093 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
3094 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
3095 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
3096 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
3097 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
3098 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
3099 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
3100 	sm_info->rec_prefree_segments = sm_info->main_segments *
3101 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
3102 	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
3103 		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
3104 
3105 	if (!test_opt(sbi, LFS))
3106 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
3107 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
3108 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
3109 	sm_info->min_hot_blocks = DEF_MIN_HOT_BLOCKS;
3110 
3111 	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
3112 
3113 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
3114 
3115 	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
3116 		err = create_flush_cmd_control(sbi);
3117 		if (err)
3118 			return err;
3119 	}
3120 
3121 	err = create_discard_cmd_control(sbi);
3122 	if (err)
3123 		return err;
3124 
3125 	err = build_sit_info(sbi);
3126 	if (err)
3127 		return err;
3128 	err = build_free_segmap(sbi);
3129 	if (err)
3130 		return err;
3131 	err = build_curseg(sbi);
3132 	if (err)
3133 		return err;
3134 
3135 	/* reinit free segmap based on SIT */
3136 	build_sit_entries(sbi);
3137 
3138 	init_free_segmap(sbi);
3139 	err = build_dirty_segmap(sbi);
3140 	if (err)
3141 		return err;
3142 
3143 	init_min_max_mtime(sbi);
3144 	return 0;
3145 }
3146 
3147 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
3148 		enum dirty_type dirty_type)
3149 {
3150 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3151 
3152 	mutex_lock(&dirty_i->seglist_lock);
3153 	kvfree(dirty_i->dirty_segmap[dirty_type]);
3154 	dirty_i->nr_dirty[dirty_type] = 0;
3155 	mutex_unlock(&dirty_i->seglist_lock);
3156 }
3157 
3158 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
3159 {
3160 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3161 	kvfree(dirty_i->victim_secmap);
3162 }
3163 
3164 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
3165 {
3166 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3167 	int i;
3168 
3169 	if (!dirty_i)
3170 		return;
3171 
3172 	/* discard pre-free/dirty segments list */
3173 	for (i = 0; i < NR_DIRTY_TYPE; i++)
3174 		discard_dirty_segmap(sbi, i);
3175 
3176 	destroy_victim_secmap(sbi);
3177 	SM_I(sbi)->dirty_info = NULL;
3178 	kfree(dirty_i);
3179 }
3180 
3181 static void destroy_curseg(struct f2fs_sb_info *sbi)
3182 {
3183 	struct curseg_info *array = SM_I(sbi)->curseg_array;
3184 	int i;
3185 
3186 	if (!array)
3187 		return;
3188 	SM_I(sbi)->curseg_array = NULL;
3189 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
3190 		kfree(array[i].sum_blk);
3191 		kfree(array[i].journal);
3192 	}
3193 	kfree(array);
3194 }
3195 
3196 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
3197 {
3198 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
3199 	if (!free_i)
3200 		return;
3201 	SM_I(sbi)->free_info = NULL;
3202 	kvfree(free_i->free_segmap);
3203 	kvfree(free_i->free_secmap);
3204 	kfree(free_i);
3205 }
3206 
3207 static void destroy_sit_info(struct f2fs_sb_info *sbi)
3208 {
3209 	struct sit_info *sit_i = SIT_I(sbi);
3210 	unsigned int start;
3211 
3212 	if (!sit_i)
3213 		return;
3214 
3215 	if (sit_i->sentries) {
3216 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
3217 			kfree(sit_i->sentries[start].cur_valid_map);
3218 #ifdef CONFIG_F2FS_CHECK_FS
3219 			kfree(sit_i->sentries[start].cur_valid_map_mir);
3220 #endif
3221 			kfree(sit_i->sentries[start].ckpt_valid_map);
3222 			kfree(sit_i->sentries[start].discard_map);
3223 		}
3224 	}
3225 	kfree(sit_i->tmp_map);
3226 
3227 	kvfree(sit_i->sentries);
3228 	kvfree(sit_i->sec_entries);
3229 	kvfree(sit_i->dirty_sentries_bitmap);
3230 
3231 	SM_I(sbi)->sit_info = NULL;
3232 	kfree(sit_i->sit_bitmap);
3233 #ifdef CONFIG_F2FS_CHECK_FS
3234 	kfree(sit_i->sit_bitmap_mir);
3235 #endif
3236 	kfree(sit_i);
3237 }
3238 
3239 void destroy_segment_manager(struct f2fs_sb_info *sbi)
3240 {
3241 	struct f2fs_sm_info *sm_info = SM_I(sbi);
3242 
3243 	if (!sm_info)
3244 		return;
3245 	destroy_flush_cmd_control(sbi, true);
3246 	destroy_discard_cmd_control(sbi);
3247 	destroy_dirty_segmap(sbi);
3248 	destroy_curseg(sbi);
3249 	destroy_free_segmap(sbi);
3250 	destroy_sit_info(sbi);
3251 	sbi->sm_info = NULL;
3252 	kfree(sm_info);
3253 }
3254 
3255 int __init create_segment_manager_caches(void)
3256 {
3257 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
3258 			sizeof(struct discard_entry));
3259 	if (!discard_entry_slab)
3260 		goto fail;
3261 
3262 	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
3263 			sizeof(struct discard_cmd));
3264 	if (!discard_cmd_slab)
3265 		goto destroy_discard_entry;
3266 
3267 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
3268 			sizeof(struct sit_entry_set));
3269 	if (!sit_entry_set_slab)
3270 		goto destroy_discard_cmd;
3271 
3272 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
3273 			sizeof(struct inmem_pages));
3274 	if (!inmem_entry_slab)
3275 		goto destroy_sit_entry_set;
3276 	return 0;
3277 
3278 destroy_sit_entry_set:
3279 	kmem_cache_destroy(sit_entry_set_slab);
3280 destroy_discard_cmd:
3281 	kmem_cache_destroy(discard_cmd_slab);
3282 destroy_discard_entry:
3283 	kmem_cache_destroy(discard_entry_slab);
3284 fail:
3285 	return -ENOMEM;
3286 }
3287 
3288 void destroy_segment_manager_caches(void)
3289 {
3290 	kmem_cache_destroy(sit_entry_set_slab);
3291 	kmem_cache_destroy(discard_cmd_slab);
3292 	kmem_cache_destroy(discard_entry_slab);
3293 	kmem_cache_destroy(inmem_entry_slab);
3294 }
3295