xref: /openbmc/linux/fs/f2fs/segment.c (revision 55523519bc7227e651fd4febeb3aafdd22b8af1c)
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 static int __commit_inmem_pages(struct inode *inode,
254 					struct list_head *revoke_list)
255 {
256 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
257 	struct f2fs_inode_info *fi = F2FS_I(inode);
258 	struct inmem_pages *cur, *tmp;
259 	struct f2fs_io_info fio = {
260 		.sbi = sbi,
261 		.type = DATA,
262 		.op = REQ_OP_WRITE,
263 		.op_flags = REQ_SYNC | REQ_PRIO,
264 		.encrypted_page = NULL,
265 	};
266 	pgoff_t last_idx = ULONG_MAX;
267 	int err = 0;
268 
269 	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
270 		struct page *page = cur->page;
271 
272 		lock_page(page);
273 		if (page->mapping == inode->i_mapping) {
274 			trace_f2fs_commit_inmem_page(page, INMEM);
275 
276 			set_page_dirty(page);
277 			f2fs_wait_on_page_writeback(page, DATA, true);
278 			if (clear_page_dirty_for_io(page)) {
279 				inode_dec_dirty_pages(inode);
280 				remove_dirty_inode(inode);
281 			}
282 
283 			fio.page = page;
284 			err = do_write_data_page(&fio);
285 			if (err) {
286 				unlock_page(page);
287 				break;
288 			}
289 
290 			/* record old blkaddr for revoking */
291 			cur->old_addr = fio.old_blkaddr;
292 			last_idx = page->index;
293 		}
294 		unlock_page(page);
295 		list_move_tail(&cur->list, revoke_list);
296 	}
297 
298 	if (last_idx != ULONG_MAX)
299 		f2fs_submit_merged_bio_cond(sbi, inode, 0, last_idx,
300 							DATA, WRITE);
301 
302 	if (!err)
303 		__revoke_inmem_pages(inode, revoke_list, false, false);
304 
305 	return err;
306 }
307 
308 int commit_inmem_pages(struct inode *inode)
309 {
310 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
311 	struct f2fs_inode_info *fi = F2FS_I(inode);
312 	struct list_head revoke_list;
313 	int err;
314 
315 	INIT_LIST_HEAD(&revoke_list);
316 	f2fs_balance_fs(sbi, true);
317 	f2fs_lock_op(sbi);
318 
319 	set_inode_flag(inode, FI_ATOMIC_COMMIT);
320 
321 	mutex_lock(&fi->inmem_lock);
322 	err = __commit_inmem_pages(inode, &revoke_list);
323 	if (err) {
324 		int ret;
325 		/*
326 		 * try to revoke all committed pages, but still we could fail
327 		 * due to no memory or other reason, if that happened, EAGAIN
328 		 * will be returned, which means in such case, transaction is
329 		 * already not integrity, caller should use journal to do the
330 		 * recovery or rewrite & commit last transaction. For other
331 		 * error number, revoking was done by filesystem itself.
332 		 */
333 		ret = __revoke_inmem_pages(inode, &revoke_list, false, true);
334 		if (ret)
335 			err = ret;
336 
337 		/* drop all uncommitted pages */
338 		__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
339 	}
340 	mutex_unlock(&fi->inmem_lock);
341 
342 	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
343 
344 	f2fs_unlock_op(sbi);
345 	return err;
346 }
347 
348 /*
349  * This function balances dirty node and dentry pages.
350  * In addition, it controls garbage collection.
351  */
352 void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
353 {
354 #ifdef CONFIG_F2FS_FAULT_INJECTION
355 	if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
356 		f2fs_show_injection_info(FAULT_CHECKPOINT);
357 		f2fs_stop_checkpoint(sbi, false);
358 	}
359 #endif
360 
361 	if (!need)
362 		return;
363 
364 	/* balance_fs_bg is able to be pending */
365 	if (excess_cached_nats(sbi))
366 		f2fs_balance_fs_bg(sbi);
367 
368 	/*
369 	 * We should do GC or end up with checkpoint, if there are so many dirty
370 	 * dir/node pages without enough free segments.
371 	 */
372 	if (has_not_enough_free_secs(sbi, 0, 0)) {
373 		mutex_lock(&sbi->gc_mutex);
374 		f2fs_gc(sbi, false, false);
375 	}
376 }
377 
378 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
379 {
380 	/* try to shrink extent cache when there is no enough memory */
381 	if (!available_free_memory(sbi, EXTENT_CACHE))
382 		f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
383 
384 	/* check the # of cached NAT entries */
385 	if (!available_free_memory(sbi, NAT_ENTRIES))
386 		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
387 
388 	if (!available_free_memory(sbi, FREE_NIDS))
389 		try_to_free_nids(sbi, MAX_FREE_NIDS);
390 	else
391 		build_free_nids(sbi, false, false);
392 
393 	if (!is_idle(sbi))
394 		return;
395 
396 	/* checkpoint is the only way to shrink partial cached entries */
397 	if (!available_free_memory(sbi, NAT_ENTRIES) ||
398 			!available_free_memory(sbi, INO_ENTRIES) ||
399 			excess_prefree_segs(sbi) ||
400 			excess_dirty_nats(sbi) ||
401 			f2fs_time_over(sbi, CP_TIME)) {
402 		if (test_opt(sbi, DATA_FLUSH)) {
403 			struct blk_plug plug;
404 
405 			blk_start_plug(&plug);
406 			sync_dirty_inodes(sbi, FILE_INODE);
407 			blk_finish_plug(&plug);
408 		}
409 		f2fs_sync_fs(sbi->sb, true);
410 		stat_inc_bg_cp_count(sbi->stat_info);
411 	}
412 }
413 
414 static int __submit_flush_wait(struct block_device *bdev)
415 {
416 	struct bio *bio = f2fs_bio_alloc(0);
417 	int ret;
418 
419 	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
420 	bio->bi_bdev = bdev;
421 	ret = submit_bio_wait(bio);
422 	bio_put(bio);
423 	return ret;
424 }
425 
426 static int submit_flush_wait(struct f2fs_sb_info *sbi)
427 {
428 	int ret = __submit_flush_wait(sbi->sb->s_bdev);
429 	int i;
430 
431 	if (sbi->s_ndevs && !ret) {
432 		for (i = 1; i < sbi->s_ndevs; i++) {
433 			trace_f2fs_issue_flush(FDEV(i).bdev,
434 					test_opt(sbi, NOBARRIER),
435 					test_opt(sbi, FLUSH_MERGE));
436 			ret = __submit_flush_wait(FDEV(i).bdev);
437 			if (ret)
438 				break;
439 		}
440 	}
441 	return ret;
442 }
443 
444 static int issue_flush_thread(void *data)
445 {
446 	struct f2fs_sb_info *sbi = data;
447 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
448 	wait_queue_head_t *q = &fcc->flush_wait_queue;
449 repeat:
450 	if (kthread_should_stop())
451 		return 0;
452 
453 	if (!llist_empty(&fcc->issue_list)) {
454 		struct flush_cmd *cmd, *next;
455 		int ret;
456 
457 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
458 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
459 
460 		ret = submit_flush_wait(sbi);
461 		llist_for_each_entry_safe(cmd, next,
462 					  fcc->dispatch_list, llnode) {
463 			cmd->ret = ret;
464 			complete(&cmd->wait);
465 		}
466 		fcc->dispatch_list = NULL;
467 	}
468 
469 	wait_event_interruptible(*q,
470 		kthread_should_stop() || !llist_empty(&fcc->issue_list));
471 	goto repeat;
472 }
473 
474 int f2fs_issue_flush(struct f2fs_sb_info *sbi)
475 {
476 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
477 	struct flush_cmd cmd;
478 
479 	if (test_opt(sbi, NOBARRIER))
480 		return 0;
481 
482 	if (!test_opt(sbi, FLUSH_MERGE))
483 		return submit_flush_wait(sbi);
484 
485 	if (!atomic_read(&fcc->submit_flush)) {
486 		int ret;
487 
488 		atomic_inc(&fcc->submit_flush);
489 		ret = submit_flush_wait(sbi);
490 		atomic_dec(&fcc->submit_flush);
491 		return ret;
492 	}
493 
494 	init_completion(&cmd.wait);
495 
496 	atomic_inc(&fcc->submit_flush);
497 	llist_add(&cmd.llnode, &fcc->issue_list);
498 
499 	if (!fcc->dispatch_list)
500 		wake_up(&fcc->flush_wait_queue);
501 
502 	if (fcc->f2fs_issue_flush) {
503 		wait_for_completion(&cmd.wait);
504 		atomic_dec(&fcc->submit_flush);
505 	} else {
506 		llist_del_all(&fcc->issue_list);
507 		atomic_set(&fcc->submit_flush, 0);
508 	}
509 
510 	return cmd.ret;
511 }
512 
513 int create_flush_cmd_control(struct f2fs_sb_info *sbi)
514 {
515 	dev_t dev = sbi->sb->s_bdev->bd_dev;
516 	struct flush_cmd_control *fcc;
517 	int err = 0;
518 
519 	if (SM_I(sbi)->fcc_info) {
520 		fcc = SM_I(sbi)->fcc_info;
521 		goto init_thread;
522 	}
523 
524 	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
525 	if (!fcc)
526 		return -ENOMEM;
527 	atomic_set(&fcc->submit_flush, 0);
528 	init_waitqueue_head(&fcc->flush_wait_queue);
529 	init_llist_head(&fcc->issue_list);
530 	SM_I(sbi)->fcc_info = fcc;
531 init_thread:
532 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
533 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
534 	if (IS_ERR(fcc->f2fs_issue_flush)) {
535 		err = PTR_ERR(fcc->f2fs_issue_flush);
536 		kfree(fcc);
537 		SM_I(sbi)->fcc_info = NULL;
538 		return err;
539 	}
540 
541 	return err;
542 }
543 
544 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
545 {
546 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
547 
548 	if (fcc && fcc->f2fs_issue_flush) {
549 		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
550 
551 		fcc->f2fs_issue_flush = NULL;
552 		kthread_stop(flush_thread);
553 	}
554 	if (free) {
555 		kfree(fcc);
556 		SM_I(sbi)->fcc_info = NULL;
557 	}
558 }
559 
560 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
561 		enum dirty_type dirty_type)
562 {
563 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
564 
565 	/* need not be added */
566 	if (IS_CURSEG(sbi, segno))
567 		return;
568 
569 	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
570 		dirty_i->nr_dirty[dirty_type]++;
571 
572 	if (dirty_type == DIRTY) {
573 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
574 		enum dirty_type t = sentry->type;
575 
576 		if (unlikely(t >= DIRTY)) {
577 			f2fs_bug_on(sbi, 1);
578 			return;
579 		}
580 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
581 			dirty_i->nr_dirty[t]++;
582 	}
583 }
584 
585 static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
586 		enum dirty_type dirty_type)
587 {
588 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
589 
590 	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
591 		dirty_i->nr_dirty[dirty_type]--;
592 
593 	if (dirty_type == DIRTY) {
594 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
595 		enum dirty_type t = sentry->type;
596 
597 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
598 			dirty_i->nr_dirty[t]--;
599 
600 		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
601 			clear_bit(GET_SECNO(sbi, segno),
602 						dirty_i->victim_secmap);
603 	}
604 }
605 
606 /*
607  * Should not occur error such as -ENOMEM.
608  * Adding dirty entry into seglist is not critical operation.
609  * If a given segment is one of current working segments, it won't be added.
610  */
611 static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
612 {
613 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
614 	unsigned short valid_blocks;
615 
616 	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
617 		return;
618 
619 	mutex_lock(&dirty_i->seglist_lock);
620 
621 	valid_blocks = get_valid_blocks(sbi, segno, 0);
622 
623 	if (valid_blocks == 0) {
624 		__locate_dirty_segment(sbi, segno, PRE);
625 		__remove_dirty_segment(sbi, segno, DIRTY);
626 	} else if (valid_blocks < sbi->blocks_per_seg) {
627 		__locate_dirty_segment(sbi, segno, DIRTY);
628 	} else {
629 		/* Recovery routine with SSR needs this */
630 		__remove_dirty_segment(sbi, segno, DIRTY);
631 	}
632 
633 	mutex_unlock(&dirty_i->seglist_lock);
634 }
635 
636 static void __add_discard_cmd(struct f2fs_sb_info *sbi,
637 			struct bio *bio, block_t lstart, block_t len)
638 {
639 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
640 	struct list_head *cmd_list = &(dcc->discard_cmd_list);
641 	struct discard_cmd *dc;
642 
643 	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
644 	INIT_LIST_HEAD(&dc->list);
645 	dc->bio = bio;
646 	bio->bi_private = dc;
647 	dc->lstart = lstart;
648 	dc->len = len;
649 	dc->state = D_PREP;
650 	init_completion(&dc->wait);
651 
652 	mutex_lock(&dcc->cmd_lock);
653 	list_add_tail(&dc->list, cmd_list);
654 	mutex_unlock(&dcc->cmd_lock);
655 }
656 
657 static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd *dc)
658 {
659 	int err = dc->bio->bi_error;
660 
661 	if (dc->state == D_DONE)
662 		atomic_dec(&(SM_I(sbi)->dcc_info->submit_discard));
663 
664 	if (err == -EOPNOTSUPP)
665 		err = 0;
666 
667 	if (err)
668 		f2fs_msg(sbi->sb, KERN_INFO,
669 				"Issue discard failed, ret: %d", err);
670 	bio_put(dc->bio);
671 	list_del(&dc->list);
672 	kmem_cache_free(discard_cmd_slab, dc);
673 }
674 
675 /* This should be covered by global mutex, &sit_i->sentry_lock */
676 void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
677 {
678 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
679 	struct list_head *wait_list = &(dcc->discard_cmd_list);
680 	struct discard_cmd *dc, *tmp;
681 	struct blk_plug plug;
682 
683 	mutex_lock(&dcc->cmd_lock);
684 
685 	blk_start_plug(&plug);
686 
687 	list_for_each_entry_safe(dc, tmp, wait_list, list) {
688 
689 		if (blkaddr == NULL_ADDR) {
690 			if (dc->state == D_PREP) {
691 				dc->state = D_SUBMIT;
692 				submit_bio(dc->bio);
693 				atomic_inc(&dcc->submit_discard);
694 			}
695 			continue;
696 		}
697 
698 		if (dc->lstart <= blkaddr && blkaddr < dc->lstart + dc->len) {
699 			if (dc->state == D_SUBMIT)
700 				wait_for_completion_io(&dc->wait);
701 			else
702 				__remove_discard_cmd(sbi, dc);
703 		}
704 	}
705 	blk_finish_plug(&plug);
706 
707 	/* this comes from f2fs_put_super */
708 	if (blkaddr == NULL_ADDR) {
709 		list_for_each_entry_safe(dc, tmp, wait_list, list) {
710 			wait_for_completion_io(&dc->wait);
711 			__remove_discard_cmd(sbi, dc);
712 		}
713 	}
714 	mutex_unlock(&dcc->cmd_lock);
715 }
716 
717 static void f2fs_submit_discard_endio(struct bio *bio)
718 {
719 	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
720 
721 	complete(&dc->wait);
722 	dc->state = D_DONE;
723 }
724 
725 static int issue_discard_thread(void *data)
726 {
727 	struct f2fs_sb_info *sbi = data;
728 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
729 	wait_queue_head_t *q = &dcc->discard_wait_queue;
730 	struct list_head *cmd_list = &dcc->discard_cmd_list;
731 	struct discard_cmd *dc, *tmp;
732 	struct blk_plug plug;
733 	int iter = 0;
734 repeat:
735 	if (kthread_should_stop())
736 		return 0;
737 
738 	blk_start_plug(&plug);
739 
740 	mutex_lock(&dcc->cmd_lock);
741 	list_for_each_entry_safe(dc, tmp, cmd_list, list) {
742 		if (dc->state == D_PREP) {
743 			dc->state = D_SUBMIT;
744 			submit_bio(dc->bio);
745 			atomic_inc(&dcc->submit_discard);
746 			if (iter++ > DISCARD_ISSUE_RATE)
747 				break;
748 		} else if (dc->state == D_DONE) {
749 			__remove_discard_cmd(sbi, dc);
750 		}
751 	}
752 	mutex_unlock(&dcc->cmd_lock);
753 
754 	blk_finish_plug(&plug);
755 
756 	iter = 0;
757 	congestion_wait(BLK_RW_SYNC, HZ/50);
758 
759 	wait_event_interruptible(*q,
760 		kthread_should_stop() || !list_empty(&dcc->discard_cmd_list));
761 	goto repeat;
762 }
763 
764 
765 /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
766 static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
767 		struct block_device *bdev, block_t blkstart, block_t blklen)
768 {
769 	struct bio *bio = NULL;
770 	block_t lblkstart = blkstart;
771 	int err;
772 
773 	trace_f2fs_issue_discard(bdev, blkstart, blklen);
774 
775 	if (sbi->s_ndevs) {
776 		int devi = f2fs_target_device_index(sbi, blkstart);
777 
778 		blkstart -= FDEV(devi).start_blk;
779 	}
780 	err = __blkdev_issue_discard(bdev,
781 				SECTOR_FROM_BLOCK(blkstart),
782 				SECTOR_FROM_BLOCK(blklen),
783 				GFP_NOFS, 0, &bio);
784 	if (!err && bio) {
785 		bio->bi_end_io = f2fs_submit_discard_endio;
786 		bio->bi_opf |= REQ_SYNC;
787 
788 		__add_discard_cmd(sbi, bio, lblkstart, blklen);
789 		wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
790 	}
791 	return err;
792 }
793 
794 #ifdef CONFIG_BLK_DEV_ZONED
795 static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
796 		struct block_device *bdev, block_t blkstart, block_t blklen)
797 {
798 	sector_t sector, nr_sects;
799 	int devi = 0;
800 
801 	if (sbi->s_ndevs) {
802 		devi = f2fs_target_device_index(sbi, blkstart);
803 		blkstart -= FDEV(devi).start_blk;
804 	}
805 
806 	/*
807 	 * We need to know the type of the zone: for conventional zones,
808 	 * use regular discard if the drive supports it. For sequential
809 	 * zones, reset the zone write pointer.
810 	 */
811 	switch (get_blkz_type(sbi, bdev, blkstart)) {
812 
813 	case BLK_ZONE_TYPE_CONVENTIONAL:
814 		if (!blk_queue_discard(bdev_get_queue(bdev)))
815 			return 0;
816 		return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
817 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
818 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
819 		sector = SECTOR_FROM_BLOCK(blkstart);
820 		nr_sects = SECTOR_FROM_BLOCK(blklen);
821 
822 		if (sector & (bdev_zone_sectors(bdev) - 1) ||
823 				nr_sects != bdev_zone_sectors(bdev)) {
824 			f2fs_msg(sbi->sb, KERN_INFO,
825 				"(%d) %s: Unaligned discard attempted (block %x + %x)",
826 				devi, sbi->s_ndevs ? FDEV(devi).path: "",
827 				blkstart, blklen);
828 			return -EIO;
829 		}
830 		trace_f2fs_issue_reset_zone(bdev, blkstart);
831 		return blkdev_reset_zones(bdev, sector,
832 					  nr_sects, GFP_NOFS);
833 	default:
834 		/* Unknown zone type: broken device ? */
835 		return -EIO;
836 	}
837 }
838 #endif
839 
840 static int __issue_discard_async(struct f2fs_sb_info *sbi,
841 		struct block_device *bdev, block_t blkstart, block_t blklen)
842 {
843 #ifdef CONFIG_BLK_DEV_ZONED
844 	if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
845 				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
846 		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
847 #endif
848 	return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
849 }
850 
851 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
852 				block_t blkstart, block_t blklen)
853 {
854 	sector_t start = blkstart, len = 0;
855 	struct block_device *bdev;
856 	struct seg_entry *se;
857 	unsigned int offset;
858 	block_t i;
859 	int err = 0;
860 
861 	bdev = f2fs_target_device(sbi, blkstart, NULL);
862 
863 	for (i = blkstart; i < blkstart + blklen; i++, len++) {
864 		if (i != start) {
865 			struct block_device *bdev2 =
866 				f2fs_target_device(sbi, i, NULL);
867 
868 			if (bdev2 != bdev) {
869 				err = __issue_discard_async(sbi, bdev,
870 						start, len);
871 				if (err)
872 					return err;
873 				bdev = bdev2;
874 				start = i;
875 				len = 0;
876 			}
877 		}
878 
879 		se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
880 		offset = GET_BLKOFF_FROM_SEG0(sbi, i);
881 
882 		if (!f2fs_test_and_set_bit(offset, se->discard_map))
883 			sbi->discard_blks--;
884 	}
885 
886 	if (len)
887 		err = __issue_discard_async(sbi, bdev, start, len);
888 	return err;
889 }
890 
891 static void __add_discard_entry(struct f2fs_sb_info *sbi,
892 		struct cp_control *cpc, struct seg_entry *se,
893 		unsigned int start, unsigned int end)
894 {
895 	struct list_head *head = &SM_I(sbi)->dcc_info->discard_entry_list;
896 	struct discard_entry *new, *last;
897 
898 	if (!list_empty(head)) {
899 		last = list_last_entry(head, struct discard_entry, list);
900 		if (START_BLOCK(sbi, cpc->trim_start) + start ==
901 				last->blkaddr + last->len &&
902 				last->len < MAX_DISCARD_BLOCKS(sbi)) {
903 			last->len += end - start;
904 			goto done;
905 		}
906 	}
907 
908 	new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
909 	INIT_LIST_HEAD(&new->list);
910 	new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
911 	new->len = end - start;
912 	list_add_tail(&new->list, head);
913 done:
914 	SM_I(sbi)->dcc_info->nr_discards += end - start;
915 }
916 
917 static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
918 							bool check_only)
919 {
920 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
921 	int max_blocks = sbi->blocks_per_seg;
922 	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
923 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
924 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
925 	unsigned long *discard_map = (unsigned long *)se->discard_map;
926 	unsigned long *dmap = SIT_I(sbi)->tmp_map;
927 	unsigned int start = 0, end = -1;
928 	bool force = (cpc->reason == CP_DISCARD);
929 	int i;
930 
931 	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
932 		return false;
933 
934 	if (!force) {
935 		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
936 			SM_I(sbi)->dcc_info->nr_discards >=
937 				SM_I(sbi)->dcc_info->max_discards)
938 			return false;
939 	}
940 
941 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
942 	for (i = 0; i < entries; i++)
943 		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
944 				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
945 
946 	while (force || SM_I(sbi)->dcc_info->nr_discards <=
947 				SM_I(sbi)->dcc_info->max_discards) {
948 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
949 		if (start >= max_blocks)
950 			break;
951 
952 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
953 		if (force && start && end != max_blocks
954 					&& (end - start) < cpc->trim_minlen)
955 			continue;
956 
957 		if (check_only)
958 			return true;
959 
960 		__add_discard_entry(sbi, cpc, se, start, end);
961 	}
962 	return false;
963 }
964 
965 void release_discard_addrs(struct f2fs_sb_info *sbi)
966 {
967 	struct list_head *head = &(SM_I(sbi)->dcc_info->discard_entry_list);
968 	struct discard_entry *entry, *this;
969 
970 	/* drop caches */
971 	list_for_each_entry_safe(entry, this, head, list) {
972 		list_del(&entry->list);
973 		kmem_cache_free(discard_entry_slab, entry);
974 	}
975 }
976 
977 /*
978  * Should call clear_prefree_segments after checkpoint is done.
979  */
980 static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
981 {
982 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
983 	unsigned int segno;
984 
985 	mutex_lock(&dirty_i->seglist_lock);
986 	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
987 		__set_test_and_free(sbi, segno);
988 	mutex_unlock(&dirty_i->seglist_lock);
989 }
990 
991 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
992 {
993 	struct list_head *head = &(SM_I(sbi)->dcc_info->discard_entry_list);
994 	struct discard_entry *entry, *this;
995 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
996 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
997 	unsigned int start = 0, end = -1;
998 	unsigned int secno, start_segno;
999 	bool force = (cpc->reason == CP_DISCARD);
1000 
1001 	mutex_lock(&dirty_i->seglist_lock);
1002 
1003 	while (1) {
1004 		int i;
1005 		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
1006 		if (start >= MAIN_SEGS(sbi))
1007 			break;
1008 		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
1009 								start + 1);
1010 
1011 		for (i = start; i < end; i++)
1012 			clear_bit(i, prefree_map);
1013 
1014 		dirty_i->nr_dirty[PRE] -= end - start;
1015 
1016 		if (!test_opt(sbi, DISCARD))
1017 			continue;
1018 
1019 		if (force && start >= cpc->trim_start &&
1020 					(end - 1) <= cpc->trim_end)
1021 				continue;
1022 
1023 		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
1024 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
1025 				(end - start) << sbi->log_blocks_per_seg);
1026 			continue;
1027 		}
1028 next:
1029 		secno = GET_SECNO(sbi, start);
1030 		start_segno = secno * sbi->segs_per_sec;
1031 		if (!IS_CURSEC(sbi, secno) &&
1032 			!get_valid_blocks(sbi, start, sbi->segs_per_sec))
1033 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
1034 				sbi->segs_per_sec << sbi->log_blocks_per_seg);
1035 
1036 		start = start_segno + sbi->segs_per_sec;
1037 		if (start < end)
1038 			goto next;
1039 	}
1040 	mutex_unlock(&dirty_i->seglist_lock);
1041 
1042 	/* send small discards */
1043 	list_for_each_entry_safe(entry, this, head, list) {
1044 		if (force && entry->len < cpc->trim_minlen)
1045 			goto skip;
1046 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
1047 		cpc->trimmed += entry->len;
1048 skip:
1049 		list_del(&entry->list);
1050 		SM_I(sbi)->dcc_info->nr_discards -= entry->len;
1051 		kmem_cache_free(discard_entry_slab, entry);
1052 	}
1053 }
1054 
1055 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
1056 {
1057 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1058 	struct discard_cmd_control *dcc;
1059 	int err = 0;
1060 
1061 	if (SM_I(sbi)->dcc_info) {
1062 		dcc = SM_I(sbi)->dcc_info;
1063 		goto init_thread;
1064 	}
1065 
1066 	dcc = kzalloc(sizeof(struct discard_cmd_control), GFP_KERNEL);
1067 	if (!dcc)
1068 		return -ENOMEM;
1069 
1070 	INIT_LIST_HEAD(&dcc->discard_entry_list);
1071 	INIT_LIST_HEAD(&dcc->discard_cmd_list);
1072 	mutex_init(&dcc->cmd_lock);
1073 	atomic_set(&dcc->submit_discard, 0);
1074 	dcc->nr_discards = 0;
1075 	dcc->max_discards = 0;
1076 
1077 	init_waitqueue_head(&dcc->discard_wait_queue);
1078 	SM_I(sbi)->dcc_info = dcc;
1079 init_thread:
1080 	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
1081 				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
1082 	if (IS_ERR(dcc->f2fs_issue_discard)) {
1083 		err = PTR_ERR(dcc->f2fs_issue_discard);
1084 		kfree(dcc);
1085 		SM_I(sbi)->dcc_info = NULL;
1086 		return err;
1087 	}
1088 
1089 	return err;
1090 }
1091 
1092 static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi, bool free)
1093 {
1094 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1095 
1096 	if (dcc && dcc->f2fs_issue_discard) {
1097 		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
1098 
1099 		dcc->f2fs_issue_discard = NULL;
1100 		kthread_stop(discard_thread);
1101 	}
1102 	if (free) {
1103 		kfree(dcc);
1104 		SM_I(sbi)->dcc_info = NULL;
1105 	}
1106 }
1107 
1108 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
1109 {
1110 	struct sit_info *sit_i = SIT_I(sbi);
1111 
1112 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
1113 		sit_i->dirty_sentries++;
1114 		return false;
1115 	}
1116 
1117 	return true;
1118 }
1119 
1120 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
1121 					unsigned int segno, int modified)
1122 {
1123 	struct seg_entry *se = get_seg_entry(sbi, segno);
1124 	se->type = type;
1125 	if (modified)
1126 		__mark_sit_entry_dirty(sbi, segno);
1127 }
1128 
1129 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
1130 {
1131 	struct seg_entry *se;
1132 	unsigned int segno, offset;
1133 	long int new_vblocks;
1134 
1135 	segno = GET_SEGNO(sbi, blkaddr);
1136 
1137 	se = get_seg_entry(sbi, segno);
1138 	new_vblocks = se->valid_blocks + del;
1139 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1140 
1141 	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
1142 				(new_vblocks > sbi->blocks_per_seg)));
1143 
1144 	se->valid_blocks = new_vblocks;
1145 	se->mtime = get_mtime(sbi);
1146 	SIT_I(sbi)->max_mtime = se->mtime;
1147 
1148 	/* Update valid block bitmap */
1149 	if (del > 0) {
1150 		if (f2fs_test_and_set_bit(offset, se->cur_valid_map)) {
1151 #ifdef CONFIG_F2FS_CHECK_FS
1152 			if (f2fs_test_and_set_bit(offset,
1153 						se->cur_valid_map_mir))
1154 				f2fs_bug_on(sbi, 1);
1155 			else
1156 				WARN_ON(1);
1157 #else
1158 			f2fs_bug_on(sbi, 1);
1159 #endif
1160 		}
1161 		if (f2fs_discard_en(sbi) &&
1162 			!f2fs_test_and_set_bit(offset, se->discard_map))
1163 			sbi->discard_blks--;
1164 	} else {
1165 		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) {
1166 #ifdef CONFIG_F2FS_CHECK_FS
1167 			if (!f2fs_test_and_clear_bit(offset,
1168 						se->cur_valid_map_mir))
1169 				f2fs_bug_on(sbi, 1);
1170 			else
1171 				WARN_ON(1);
1172 #else
1173 			f2fs_bug_on(sbi, 1);
1174 #endif
1175 		}
1176 		if (f2fs_discard_en(sbi) &&
1177 			f2fs_test_and_clear_bit(offset, se->discard_map))
1178 			sbi->discard_blks++;
1179 	}
1180 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
1181 		se->ckpt_valid_blocks += del;
1182 
1183 	__mark_sit_entry_dirty(sbi, segno);
1184 
1185 	/* update total number of valid blocks to be written in ckpt area */
1186 	SIT_I(sbi)->written_valid_blocks += del;
1187 
1188 	if (sbi->segs_per_sec > 1)
1189 		get_sec_entry(sbi, segno)->valid_blocks += del;
1190 }
1191 
1192 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
1193 {
1194 	update_sit_entry(sbi, new, 1);
1195 	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
1196 		update_sit_entry(sbi, old, -1);
1197 
1198 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
1199 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
1200 }
1201 
1202 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
1203 {
1204 	unsigned int segno = GET_SEGNO(sbi, addr);
1205 	struct sit_info *sit_i = SIT_I(sbi);
1206 
1207 	f2fs_bug_on(sbi, addr == NULL_ADDR);
1208 	if (addr == NEW_ADDR)
1209 		return;
1210 
1211 	/* add it into sit main buffer */
1212 	mutex_lock(&sit_i->sentry_lock);
1213 
1214 	update_sit_entry(sbi, addr, -1);
1215 
1216 	/* add it into dirty seglist */
1217 	locate_dirty_segment(sbi, segno);
1218 
1219 	mutex_unlock(&sit_i->sentry_lock);
1220 }
1221 
1222 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
1223 {
1224 	struct sit_info *sit_i = SIT_I(sbi);
1225 	unsigned int segno, offset;
1226 	struct seg_entry *se;
1227 	bool is_cp = false;
1228 
1229 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1230 		return true;
1231 
1232 	mutex_lock(&sit_i->sentry_lock);
1233 
1234 	segno = GET_SEGNO(sbi, blkaddr);
1235 	se = get_seg_entry(sbi, segno);
1236 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1237 
1238 	if (f2fs_test_bit(offset, se->ckpt_valid_map))
1239 		is_cp = true;
1240 
1241 	mutex_unlock(&sit_i->sentry_lock);
1242 
1243 	return is_cp;
1244 }
1245 
1246 /*
1247  * This function should be resided under the curseg_mutex lock
1248  */
1249 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
1250 					struct f2fs_summary *sum)
1251 {
1252 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1253 	void *addr = curseg->sum_blk;
1254 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
1255 	memcpy(addr, sum, sizeof(struct f2fs_summary));
1256 }
1257 
1258 /*
1259  * Calculate the number of current summary pages for writing
1260  */
1261 int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
1262 {
1263 	int valid_sum_count = 0;
1264 	int i, sum_in_page;
1265 
1266 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1267 		if (sbi->ckpt->alloc_type[i] == SSR)
1268 			valid_sum_count += sbi->blocks_per_seg;
1269 		else {
1270 			if (for_ra)
1271 				valid_sum_count += le16_to_cpu(
1272 					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
1273 			else
1274 				valid_sum_count += curseg_blkoff(sbi, i);
1275 		}
1276 	}
1277 
1278 	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
1279 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
1280 	if (valid_sum_count <= sum_in_page)
1281 		return 1;
1282 	else if ((valid_sum_count - sum_in_page) <=
1283 		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
1284 		return 2;
1285 	return 3;
1286 }
1287 
1288 /*
1289  * Caller should put this summary page
1290  */
1291 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
1292 {
1293 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
1294 }
1295 
1296 void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
1297 {
1298 	struct page *page = grab_meta_page(sbi, blk_addr);
1299 	void *dst = page_address(page);
1300 
1301 	if (src)
1302 		memcpy(dst, src, PAGE_SIZE);
1303 	else
1304 		memset(dst, 0, PAGE_SIZE);
1305 	set_page_dirty(page);
1306 	f2fs_put_page(page, 1);
1307 }
1308 
1309 static void write_sum_page(struct f2fs_sb_info *sbi,
1310 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
1311 {
1312 	update_meta_page(sbi, (void *)sum_blk, blk_addr);
1313 }
1314 
1315 static void write_current_sum_page(struct f2fs_sb_info *sbi,
1316 						int type, block_t blk_addr)
1317 {
1318 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1319 	struct page *page = grab_meta_page(sbi, blk_addr);
1320 	struct f2fs_summary_block *src = curseg->sum_blk;
1321 	struct f2fs_summary_block *dst;
1322 
1323 	dst = (struct f2fs_summary_block *)page_address(page);
1324 
1325 	mutex_lock(&curseg->curseg_mutex);
1326 
1327 	down_read(&curseg->journal_rwsem);
1328 	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
1329 	up_read(&curseg->journal_rwsem);
1330 
1331 	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
1332 	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
1333 
1334 	mutex_unlock(&curseg->curseg_mutex);
1335 
1336 	set_page_dirty(page);
1337 	f2fs_put_page(page, 1);
1338 }
1339 
1340 /*
1341  * Find a new segment from the free segments bitmap to right order
1342  * This function should be returned with success, otherwise BUG
1343  */
1344 static void get_new_segment(struct f2fs_sb_info *sbi,
1345 			unsigned int *newseg, bool new_sec, int dir)
1346 {
1347 	struct free_segmap_info *free_i = FREE_I(sbi);
1348 	unsigned int segno, secno, zoneno;
1349 	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
1350 	unsigned int hint = *newseg / sbi->segs_per_sec;
1351 	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
1352 	unsigned int left_start = hint;
1353 	bool init = true;
1354 	int go_left = 0;
1355 	int i;
1356 
1357 	spin_lock(&free_i->segmap_lock);
1358 
1359 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
1360 		segno = find_next_zero_bit(free_i->free_segmap,
1361 				(hint + 1) * sbi->segs_per_sec, *newseg + 1);
1362 		if (segno < (hint + 1) * sbi->segs_per_sec)
1363 			goto got_it;
1364 	}
1365 find_other_zone:
1366 	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
1367 	if (secno >= MAIN_SECS(sbi)) {
1368 		if (dir == ALLOC_RIGHT) {
1369 			secno = find_next_zero_bit(free_i->free_secmap,
1370 							MAIN_SECS(sbi), 0);
1371 			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
1372 		} else {
1373 			go_left = 1;
1374 			left_start = hint - 1;
1375 		}
1376 	}
1377 	if (go_left == 0)
1378 		goto skip_left;
1379 
1380 	while (test_bit(left_start, free_i->free_secmap)) {
1381 		if (left_start > 0) {
1382 			left_start--;
1383 			continue;
1384 		}
1385 		left_start = find_next_zero_bit(free_i->free_secmap,
1386 							MAIN_SECS(sbi), 0);
1387 		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
1388 		break;
1389 	}
1390 	secno = left_start;
1391 skip_left:
1392 	hint = secno;
1393 	segno = secno * sbi->segs_per_sec;
1394 	zoneno = secno / sbi->secs_per_zone;
1395 
1396 	/* give up on finding another zone */
1397 	if (!init)
1398 		goto got_it;
1399 	if (sbi->secs_per_zone == 1)
1400 		goto got_it;
1401 	if (zoneno == old_zoneno)
1402 		goto got_it;
1403 	if (dir == ALLOC_LEFT) {
1404 		if (!go_left && zoneno + 1 >= total_zones)
1405 			goto got_it;
1406 		if (go_left && zoneno == 0)
1407 			goto got_it;
1408 	}
1409 	for (i = 0; i < NR_CURSEG_TYPE; i++)
1410 		if (CURSEG_I(sbi, i)->zone == zoneno)
1411 			break;
1412 
1413 	if (i < NR_CURSEG_TYPE) {
1414 		/* zone is in user, try another */
1415 		if (go_left)
1416 			hint = zoneno * sbi->secs_per_zone - 1;
1417 		else if (zoneno + 1 >= total_zones)
1418 			hint = 0;
1419 		else
1420 			hint = (zoneno + 1) * sbi->secs_per_zone;
1421 		init = false;
1422 		goto find_other_zone;
1423 	}
1424 got_it:
1425 	/* set it as dirty segment in free segmap */
1426 	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
1427 	__set_inuse(sbi, segno);
1428 	*newseg = segno;
1429 	spin_unlock(&free_i->segmap_lock);
1430 }
1431 
1432 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
1433 {
1434 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1435 	struct summary_footer *sum_footer;
1436 
1437 	curseg->segno = curseg->next_segno;
1438 	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
1439 	curseg->next_blkoff = 0;
1440 	curseg->next_segno = NULL_SEGNO;
1441 
1442 	sum_footer = &(curseg->sum_blk->footer);
1443 	memset(sum_footer, 0, sizeof(struct summary_footer));
1444 	if (IS_DATASEG(type))
1445 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
1446 	if (IS_NODESEG(type))
1447 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
1448 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
1449 }
1450 
1451 /*
1452  * Allocate a current working segment.
1453  * This function always allocates a free segment in LFS manner.
1454  */
1455 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
1456 {
1457 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1458 	unsigned int segno = curseg->segno;
1459 	int dir = ALLOC_LEFT;
1460 
1461 	write_sum_page(sbi, curseg->sum_blk,
1462 				GET_SUM_BLOCK(sbi, segno));
1463 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
1464 		dir = ALLOC_RIGHT;
1465 
1466 	if (test_opt(sbi, NOHEAP))
1467 		dir = ALLOC_RIGHT;
1468 
1469 	get_new_segment(sbi, &segno, new_sec, dir);
1470 	curseg->next_segno = segno;
1471 	reset_curseg(sbi, type, 1);
1472 	curseg->alloc_type = LFS;
1473 }
1474 
1475 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
1476 			struct curseg_info *seg, block_t start)
1477 {
1478 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
1479 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1480 	unsigned long *target_map = SIT_I(sbi)->tmp_map;
1481 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1482 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1483 	int i, pos;
1484 
1485 	for (i = 0; i < entries; i++)
1486 		target_map[i] = ckpt_map[i] | cur_map[i];
1487 
1488 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
1489 
1490 	seg->next_blkoff = pos;
1491 }
1492 
1493 /*
1494  * If a segment is written by LFS manner, next block offset is just obtained
1495  * by increasing the current block offset. However, if a segment is written by
1496  * SSR manner, next block offset obtained by calling __next_free_blkoff
1497  */
1498 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
1499 				struct curseg_info *seg)
1500 {
1501 	if (seg->alloc_type == SSR)
1502 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
1503 	else
1504 		seg->next_blkoff++;
1505 }
1506 
1507 /*
1508  * This function always allocates a used segment(from dirty seglist) by SSR
1509  * manner, so it should recover the existing segment information of valid blocks
1510  */
1511 static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
1512 {
1513 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1514 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1515 	unsigned int new_segno = curseg->next_segno;
1516 	struct f2fs_summary_block *sum_node;
1517 	struct page *sum_page;
1518 
1519 	write_sum_page(sbi, curseg->sum_blk,
1520 				GET_SUM_BLOCK(sbi, curseg->segno));
1521 	__set_test_and_inuse(sbi, new_segno);
1522 
1523 	mutex_lock(&dirty_i->seglist_lock);
1524 	__remove_dirty_segment(sbi, new_segno, PRE);
1525 	__remove_dirty_segment(sbi, new_segno, DIRTY);
1526 	mutex_unlock(&dirty_i->seglist_lock);
1527 
1528 	reset_curseg(sbi, type, 1);
1529 	curseg->alloc_type = SSR;
1530 	__next_free_blkoff(sbi, curseg, 0);
1531 
1532 	if (reuse) {
1533 		sum_page = get_sum_page(sbi, new_segno);
1534 		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
1535 		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
1536 		f2fs_put_page(sum_page, 1);
1537 	}
1538 }
1539 
1540 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
1541 {
1542 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1543 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
1544 	int i, n;
1545 
1546 	/* need_SSR() already forces to do this */
1547 	if (v_ops->get_victim(sbi, &(curseg)->next_segno, BG_GC, type, SSR))
1548 		return 1;
1549 
1550 	/* For node segments, let's do SSR more intensively */
1551 	if (IS_NODESEG(type)) {
1552 		i = CURSEG_HOT_NODE;
1553 		n = CURSEG_COLD_NODE;
1554 	} else {
1555 		i = CURSEG_HOT_DATA;
1556 		n = CURSEG_COLD_DATA;
1557 	}
1558 
1559 	for (; i <= n; i++) {
1560 		if (i == type)
1561 			continue;
1562 		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
1563 						BG_GC, i, SSR))
1564 			return 1;
1565 	}
1566 	return 0;
1567 }
1568 
1569 /*
1570  * flush out current segment and replace it with new segment
1571  * This function should be returned with success, otherwise BUG
1572  */
1573 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
1574 						int type, bool force)
1575 {
1576 	if (force)
1577 		new_curseg(sbi, type, true);
1578 	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
1579 					type == CURSEG_WARM_NODE)
1580 		new_curseg(sbi, type, false);
1581 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
1582 		change_curseg(sbi, type, true);
1583 	else
1584 		new_curseg(sbi, type, false);
1585 
1586 	stat_inc_seg_type(sbi, CURSEG_I(sbi, type));
1587 }
1588 
1589 void allocate_new_segments(struct f2fs_sb_info *sbi)
1590 {
1591 	struct curseg_info *curseg;
1592 	unsigned int old_segno;
1593 	int i;
1594 
1595 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1596 		curseg = CURSEG_I(sbi, i);
1597 		old_segno = curseg->segno;
1598 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
1599 		locate_dirty_segment(sbi, old_segno);
1600 	}
1601 }
1602 
1603 static const struct segment_allocation default_salloc_ops = {
1604 	.allocate_segment = allocate_segment_by_default,
1605 };
1606 
1607 bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1608 {
1609 	__u64 trim_start = cpc->trim_start;
1610 	bool has_candidate = false;
1611 
1612 	mutex_lock(&SIT_I(sbi)->sentry_lock);
1613 	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
1614 		if (add_discard_addrs(sbi, cpc, true)) {
1615 			has_candidate = true;
1616 			break;
1617 		}
1618 	}
1619 	mutex_unlock(&SIT_I(sbi)->sentry_lock);
1620 
1621 	cpc->trim_start = trim_start;
1622 	return has_candidate;
1623 }
1624 
1625 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
1626 {
1627 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
1628 	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
1629 	unsigned int start_segno, end_segno;
1630 	struct cp_control cpc;
1631 	int err = 0;
1632 
1633 	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
1634 		return -EINVAL;
1635 
1636 	cpc.trimmed = 0;
1637 	if (end <= MAIN_BLKADDR(sbi))
1638 		goto out;
1639 
1640 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1641 		f2fs_msg(sbi->sb, KERN_WARNING,
1642 			"Found FS corruption, run fsck to fix.");
1643 		goto out;
1644 	}
1645 
1646 	/* start/end segment number in main_area */
1647 	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
1648 	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
1649 						GET_SEGNO(sbi, end);
1650 	cpc.reason = CP_DISCARD;
1651 	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
1652 
1653 	/* do checkpoint to issue discard commands safely */
1654 	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
1655 		cpc.trim_start = start_segno;
1656 
1657 		if (sbi->discard_blks == 0)
1658 			break;
1659 		else if (sbi->discard_blks < BATCHED_TRIM_BLOCKS(sbi))
1660 			cpc.trim_end = end_segno;
1661 		else
1662 			cpc.trim_end = min_t(unsigned int,
1663 				rounddown(start_segno +
1664 				BATCHED_TRIM_SEGMENTS(sbi),
1665 				sbi->segs_per_sec) - 1, end_segno);
1666 
1667 		mutex_lock(&sbi->gc_mutex);
1668 		err = write_checkpoint(sbi, &cpc);
1669 		mutex_unlock(&sbi->gc_mutex);
1670 		if (err)
1671 			break;
1672 
1673 		schedule();
1674 	}
1675 out:
1676 	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
1677 	return err;
1678 }
1679 
1680 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
1681 {
1682 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1683 	if (curseg->next_blkoff < sbi->blocks_per_seg)
1684 		return true;
1685 	return false;
1686 }
1687 
1688 static int __get_segment_type_2(struct page *page, enum page_type p_type)
1689 {
1690 	if (p_type == DATA)
1691 		return CURSEG_HOT_DATA;
1692 	else
1693 		return CURSEG_HOT_NODE;
1694 }
1695 
1696 static int __get_segment_type_4(struct page *page, enum page_type p_type)
1697 {
1698 	if (p_type == DATA) {
1699 		struct inode *inode = page->mapping->host;
1700 
1701 		if (S_ISDIR(inode->i_mode))
1702 			return CURSEG_HOT_DATA;
1703 		else
1704 			return CURSEG_COLD_DATA;
1705 	} else {
1706 		if (IS_DNODE(page) && is_cold_node(page))
1707 			return CURSEG_WARM_NODE;
1708 		else
1709 			return CURSEG_COLD_NODE;
1710 	}
1711 }
1712 
1713 static int __get_segment_type_6(struct page *page, enum page_type p_type)
1714 {
1715 	if (p_type == DATA) {
1716 		struct inode *inode = page->mapping->host;
1717 
1718 		if (S_ISDIR(inode->i_mode))
1719 			return CURSEG_HOT_DATA;
1720 		else if (is_cold_data(page) || file_is_cold(inode))
1721 			return CURSEG_COLD_DATA;
1722 		else
1723 			return CURSEG_WARM_DATA;
1724 	} else {
1725 		if (IS_DNODE(page))
1726 			return is_cold_node(page) ? CURSEG_WARM_NODE :
1727 						CURSEG_HOT_NODE;
1728 		else
1729 			return CURSEG_COLD_NODE;
1730 	}
1731 }
1732 
1733 static int __get_segment_type(struct page *page, enum page_type p_type)
1734 {
1735 	switch (F2FS_P_SB(page)->active_logs) {
1736 	case 2:
1737 		return __get_segment_type_2(page, p_type);
1738 	case 4:
1739 		return __get_segment_type_4(page, p_type);
1740 	}
1741 	/* NR_CURSEG_TYPE(6) logs by default */
1742 	f2fs_bug_on(F2FS_P_SB(page),
1743 		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
1744 	return __get_segment_type_6(page, p_type);
1745 }
1746 
1747 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
1748 		block_t old_blkaddr, block_t *new_blkaddr,
1749 		struct f2fs_summary *sum, int type)
1750 {
1751 	struct sit_info *sit_i = SIT_I(sbi);
1752 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1753 
1754 	mutex_lock(&curseg->curseg_mutex);
1755 	mutex_lock(&sit_i->sentry_lock);
1756 
1757 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
1758 
1759 	f2fs_wait_discard_bio(sbi, *new_blkaddr);
1760 
1761 	/*
1762 	 * __add_sum_entry should be resided under the curseg_mutex
1763 	 * because, this function updates a summary entry in the
1764 	 * current summary block.
1765 	 */
1766 	__add_sum_entry(sbi, type, sum);
1767 
1768 	__refresh_next_blkoff(sbi, curseg);
1769 
1770 	stat_inc_block_count(sbi, curseg);
1771 
1772 	/*
1773 	 * SIT information should be updated before segment allocation,
1774 	 * since SSR needs latest valid block information.
1775 	 */
1776 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
1777 
1778 	if (!__has_curseg_space(sbi, type))
1779 		sit_i->s_ops->allocate_segment(sbi, type, false);
1780 
1781 	mutex_unlock(&sit_i->sentry_lock);
1782 
1783 	if (page && IS_NODESEG(type))
1784 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
1785 
1786 	mutex_unlock(&curseg->curseg_mutex);
1787 }
1788 
1789 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
1790 {
1791 	int type = __get_segment_type(fio->page, fio->type);
1792 	int err;
1793 
1794 	if (fio->type == NODE || fio->type == DATA)
1795 		mutex_lock(&fio->sbi->wio_mutex[fio->type]);
1796 reallocate:
1797 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
1798 					&fio->new_blkaddr, sum, type);
1799 
1800 	/* writeout dirty page into bdev */
1801 	err = f2fs_submit_page_mbio(fio);
1802 	if (err == -EAGAIN) {
1803 		fio->old_blkaddr = fio->new_blkaddr;
1804 		goto reallocate;
1805 	}
1806 
1807 	if (fio->type == NODE || fio->type == DATA)
1808 		mutex_unlock(&fio->sbi->wio_mutex[fio->type]);
1809 }
1810 
1811 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
1812 {
1813 	struct f2fs_io_info fio = {
1814 		.sbi = sbi,
1815 		.type = META,
1816 		.op = REQ_OP_WRITE,
1817 		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
1818 		.old_blkaddr = page->index,
1819 		.new_blkaddr = page->index,
1820 		.page = page,
1821 		.encrypted_page = NULL,
1822 	};
1823 
1824 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
1825 		fio.op_flags &= ~REQ_META;
1826 
1827 	set_page_writeback(page);
1828 	f2fs_submit_page_mbio(&fio);
1829 }
1830 
1831 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
1832 {
1833 	struct f2fs_summary sum;
1834 
1835 	set_summary(&sum, nid, 0, 0);
1836 	do_write_page(&sum, fio);
1837 }
1838 
1839 void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
1840 {
1841 	struct f2fs_sb_info *sbi = fio->sbi;
1842 	struct f2fs_summary sum;
1843 	struct node_info ni;
1844 
1845 	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
1846 	get_node_info(sbi, dn->nid, &ni);
1847 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
1848 	do_write_page(&sum, fio);
1849 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
1850 }
1851 
1852 void rewrite_data_page(struct f2fs_io_info *fio)
1853 {
1854 	fio->new_blkaddr = fio->old_blkaddr;
1855 	stat_inc_inplace_blocks(fio->sbi);
1856 	f2fs_submit_page_mbio(fio);
1857 }
1858 
1859 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1860 				block_t old_blkaddr, block_t new_blkaddr,
1861 				bool recover_curseg, bool recover_newaddr)
1862 {
1863 	struct sit_info *sit_i = SIT_I(sbi);
1864 	struct curseg_info *curseg;
1865 	unsigned int segno, old_cursegno;
1866 	struct seg_entry *se;
1867 	int type;
1868 	unsigned short old_blkoff;
1869 
1870 	segno = GET_SEGNO(sbi, new_blkaddr);
1871 	se = get_seg_entry(sbi, segno);
1872 	type = se->type;
1873 
1874 	if (!recover_curseg) {
1875 		/* for recovery flow */
1876 		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
1877 			if (old_blkaddr == NULL_ADDR)
1878 				type = CURSEG_COLD_DATA;
1879 			else
1880 				type = CURSEG_WARM_DATA;
1881 		}
1882 	} else {
1883 		if (!IS_CURSEG(sbi, segno))
1884 			type = CURSEG_WARM_DATA;
1885 	}
1886 
1887 	curseg = CURSEG_I(sbi, type);
1888 
1889 	mutex_lock(&curseg->curseg_mutex);
1890 	mutex_lock(&sit_i->sentry_lock);
1891 
1892 	old_cursegno = curseg->segno;
1893 	old_blkoff = curseg->next_blkoff;
1894 
1895 	/* change the current segment */
1896 	if (segno != curseg->segno) {
1897 		curseg->next_segno = segno;
1898 		change_curseg(sbi, type, true);
1899 	}
1900 
1901 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
1902 	__add_sum_entry(sbi, type, sum);
1903 
1904 	if (!recover_curseg || recover_newaddr)
1905 		update_sit_entry(sbi, new_blkaddr, 1);
1906 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
1907 		update_sit_entry(sbi, old_blkaddr, -1);
1908 
1909 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
1910 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
1911 
1912 	locate_dirty_segment(sbi, old_cursegno);
1913 
1914 	if (recover_curseg) {
1915 		if (old_cursegno != curseg->segno) {
1916 			curseg->next_segno = old_cursegno;
1917 			change_curseg(sbi, type, true);
1918 		}
1919 		curseg->next_blkoff = old_blkoff;
1920 	}
1921 
1922 	mutex_unlock(&sit_i->sentry_lock);
1923 	mutex_unlock(&curseg->curseg_mutex);
1924 }
1925 
1926 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
1927 				block_t old_addr, block_t new_addr,
1928 				unsigned char version, bool recover_curseg,
1929 				bool recover_newaddr)
1930 {
1931 	struct f2fs_summary sum;
1932 
1933 	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
1934 
1935 	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
1936 					recover_curseg, recover_newaddr);
1937 
1938 	f2fs_update_data_blkaddr(dn, new_addr);
1939 }
1940 
1941 void f2fs_wait_on_page_writeback(struct page *page,
1942 				enum page_type type, bool ordered)
1943 {
1944 	if (PageWriteback(page)) {
1945 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1946 
1947 		f2fs_submit_merged_bio_cond(sbi, page->mapping->host,
1948 						0, page->index, type, WRITE);
1949 		if (ordered)
1950 			wait_on_page_writeback(page);
1951 		else
1952 			wait_for_stable_page(page);
1953 	}
1954 }
1955 
1956 void f2fs_wait_on_encrypted_page_writeback(struct f2fs_sb_info *sbi,
1957 							block_t blkaddr)
1958 {
1959 	struct page *cpage;
1960 
1961 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1962 		return;
1963 
1964 	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
1965 	if (cpage) {
1966 		f2fs_wait_on_page_writeback(cpage, DATA, true);
1967 		f2fs_put_page(cpage, 1);
1968 	}
1969 }
1970 
1971 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
1972 {
1973 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1974 	struct curseg_info *seg_i;
1975 	unsigned char *kaddr;
1976 	struct page *page;
1977 	block_t start;
1978 	int i, j, offset;
1979 
1980 	start = start_sum_block(sbi);
1981 
1982 	page = get_meta_page(sbi, start++);
1983 	kaddr = (unsigned char *)page_address(page);
1984 
1985 	/* Step 1: restore nat cache */
1986 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
1987 	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
1988 
1989 	/* Step 2: restore sit cache */
1990 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
1991 	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
1992 	offset = 2 * SUM_JOURNAL_SIZE;
1993 
1994 	/* Step 3: restore summary entries */
1995 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1996 		unsigned short blk_off;
1997 		unsigned int segno;
1998 
1999 		seg_i = CURSEG_I(sbi, i);
2000 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
2001 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
2002 		seg_i->next_segno = segno;
2003 		reset_curseg(sbi, i, 0);
2004 		seg_i->alloc_type = ckpt->alloc_type[i];
2005 		seg_i->next_blkoff = blk_off;
2006 
2007 		if (seg_i->alloc_type == SSR)
2008 			blk_off = sbi->blocks_per_seg;
2009 
2010 		for (j = 0; j < blk_off; j++) {
2011 			struct f2fs_summary *s;
2012 			s = (struct f2fs_summary *)(kaddr + offset);
2013 			seg_i->sum_blk->entries[j] = *s;
2014 			offset += SUMMARY_SIZE;
2015 			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
2016 						SUM_FOOTER_SIZE)
2017 				continue;
2018 
2019 			f2fs_put_page(page, 1);
2020 			page = NULL;
2021 
2022 			page = get_meta_page(sbi, start++);
2023 			kaddr = (unsigned char *)page_address(page);
2024 			offset = 0;
2025 		}
2026 	}
2027 	f2fs_put_page(page, 1);
2028 	return 0;
2029 }
2030 
2031 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
2032 {
2033 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2034 	struct f2fs_summary_block *sum;
2035 	struct curseg_info *curseg;
2036 	struct page *new;
2037 	unsigned short blk_off;
2038 	unsigned int segno = 0;
2039 	block_t blk_addr = 0;
2040 
2041 	/* get segment number and block addr */
2042 	if (IS_DATASEG(type)) {
2043 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
2044 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
2045 							CURSEG_HOT_DATA]);
2046 		if (__exist_node_summaries(sbi))
2047 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
2048 		else
2049 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
2050 	} else {
2051 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
2052 							CURSEG_HOT_NODE]);
2053 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
2054 							CURSEG_HOT_NODE]);
2055 		if (__exist_node_summaries(sbi))
2056 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
2057 							type - CURSEG_HOT_NODE);
2058 		else
2059 			blk_addr = GET_SUM_BLOCK(sbi, segno);
2060 	}
2061 
2062 	new = get_meta_page(sbi, blk_addr);
2063 	sum = (struct f2fs_summary_block *)page_address(new);
2064 
2065 	if (IS_NODESEG(type)) {
2066 		if (__exist_node_summaries(sbi)) {
2067 			struct f2fs_summary *ns = &sum->entries[0];
2068 			int i;
2069 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
2070 				ns->version = 0;
2071 				ns->ofs_in_node = 0;
2072 			}
2073 		} else {
2074 			int err;
2075 
2076 			err = restore_node_summary(sbi, segno, sum);
2077 			if (err) {
2078 				f2fs_put_page(new, 1);
2079 				return err;
2080 			}
2081 		}
2082 	}
2083 
2084 	/* set uncompleted segment to curseg */
2085 	curseg = CURSEG_I(sbi, type);
2086 	mutex_lock(&curseg->curseg_mutex);
2087 
2088 	/* update journal info */
2089 	down_write(&curseg->journal_rwsem);
2090 	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
2091 	up_write(&curseg->journal_rwsem);
2092 
2093 	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
2094 	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
2095 	curseg->next_segno = segno;
2096 	reset_curseg(sbi, type, 0);
2097 	curseg->alloc_type = ckpt->alloc_type[type];
2098 	curseg->next_blkoff = blk_off;
2099 	mutex_unlock(&curseg->curseg_mutex);
2100 	f2fs_put_page(new, 1);
2101 	return 0;
2102 }
2103 
2104 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
2105 {
2106 	int type = CURSEG_HOT_DATA;
2107 	int err;
2108 
2109 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
2110 		int npages = npages_for_summary_flush(sbi, true);
2111 
2112 		if (npages >= 2)
2113 			ra_meta_pages(sbi, start_sum_block(sbi), npages,
2114 							META_CP, true);
2115 
2116 		/* restore for compacted data summary */
2117 		if (read_compacted_summaries(sbi))
2118 			return -EINVAL;
2119 		type = CURSEG_HOT_NODE;
2120 	}
2121 
2122 	if (__exist_node_summaries(sbi))
2123 		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
2124 					NR_CURSEG_TYPE - type, META_CP, true);
2125 
2126 	for (; type <= CURSEG_COLD_NODE; type++) {
2127 		err = read_normal_summaries(sbi, type);
2128 		if (err)
2129 			return err;
2130 	}
2131 
2132 	return 0;
2133 }
2134 
2135 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
2136 {
2137 	struct page *page;
2138 	unsigned char *kaddr;
2139 	struct f2fs_summary *summary;
2140 	struct curseg_info *seg_i;
2141 	int written_size = 0;
2142 	int i, j;
2143 
2144 	page = grab_meta_page(sbi, blkaddr++);
2145 	kaddr = (unsigned char *)page_address(page);
2146 
2147 	/* Step 1: write nat cache */
2148 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2149 	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
2150 	written_size += SUM_JOURNAL_SIZE;
2151 
2152 	/* Step 2: write sit cache */
2153 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2154 	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
2155 	written_size += SUM_JOURNAL_SIZE;
2156 
2157 	/* Step 3: write summary entries */
2158 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2159 		unsigned short blkoff;
2160 		seg_i = CURSEG_I(sbi, i);
2161 		if (sbi->ckpt->alloc_type[i] == SSR)
2162 			blkoff = sbi->blocks_per_seg;
2163 		else
2164 			blkoff = curseg_blkoff(sbi, i);
2165 
2166 		for (j = 0; j < blkoff; j++) {
2167 			if (!page) {
2168 				page = grab_meta_page(sbi, blkaddr++);
2169 				kaddr = (unsigned char *)page_address(page);
2170 				written_size = 0;
2171 			}
2172 			summary = (struct f2fs_summary *)(kaddr + written_size);
2173 			*summary = seg_i->sum_blk->entries[j];
2174 			written_size += SUMMARY_SIZE;
2175 
2176 			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
2177 							SUM_FOOTER_SIZE)
2178 				continue;
2179 
2180 			set_page_dirty(page);
2181 			f2fs_put_page(page, 1);
2182 			page = NULL;
2183 		}
2184 	}
2185 	if (page) {
2186 		set_page_dirty(page);
2187 		f2fs_put_page(page, 1);
2188 	}
2189 }
2190 
2191 static void write_normal_summaries(struct f2fs_sb_info *sbi,
2192 					block_t blkaddr, int type)
2193 {
2194 	int i, end;
2195 	if (IS_DATASEG(type))
2196 		end = type + NR_CURSEG_DATA_TYPE;
2197 	else
2198 		end = type + NR_CURSEG_NODE_TYPE;
2199 
2200 	for (i = type; i < end; i++)
2201 		write_current_sum_page(sbi, i, blkaddr + (i - type));
2202 }
2203 
2204 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2205 {
2206 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
2207 		write_compacted_summaries(sbi, start_blk);
2208 	else
2209 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
2210 }
2211 
2212 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2213 {
2214 	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
2215 }
2216 
2217 int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
2218 					unsigned int val, int alloc)
2219 {
2220 	int i;
2221 
2222 	if (type == NAT_JOURNAL) {
2223 		for (i = 0; i < nats_in_cursum(journal); i++) {
2224 			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
2225 				return i;
2226 		}
2227 		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
2228 			return update_nats_in_cursum(journal, 1);
2229 	} else if (type == SIT_JOURNAL) {
2230 		for (i = 0; i < sits_in_cursum(journal); i++)
2231 			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
2232 				return i;
2233 		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
2234 			return update_sits_in_cursum(journal, 1);
2235 	}
2236 	return -1;
2237 }
2238 
2239 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
2240 					unsigned int segno)
2241 {
2242 	return get_meta_page(sbi, current_sit_addr(sbi, segno));
2243 }
2244 
2245 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
2246 					unsigned int start)
2247 {
2248 	struct sit_info *sit_i = SIT_I(sbi);
2249 	struct page *src_page, *dst_page;
2250 	pgoff_t src_off, dst_off;
2251 	void *src_addr, *dst_addr;
2252 
2253 	src_off = current_sit_addr(sbi, start);
2254 	dst_off = next_sit_addr(sbi, src_off);
2255 
2256 	/* get current sit block page without lock */
2257 	src_page = get_meta_page(sbi, src_off);
2258 	dst_page = grab_meta_page(sbi, dst_off);
2259 	f2fs_bug_on(sbi, PageDirty(src_page));
2260 
2261 	src_addr = page_address(src_page);
2262 	dst_addr = page_address(dst_page);
2263 	memcpy(dst_addr, src_addr, PAGE_SIZE);
2264 
2265 	set_page_dirty(dst_page);
2266 	f2fs_put_page(src_page, 1);
2267 
2268 	set_to_next_sit(sit_i, start);
2269 
2270 	return dst_page;
2271 }
2272 
2273 static struct sit_entry_set *grab_sit_entry_set(void)
2274 {
2275 	struct sit_entry_set *ses =
2276 			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
2277 
2278 	ses->entry_cnt = 0;
2279 	INIT_LIST_HEAD(&ses->set_list);
2280 	return ses;
2281 }
2282 
2283 static void release_sit_entry_set(struct sit_entry_set *ses)
2284 {
2285 	list_del(&ses->set_list);
2286 	kmem_cache_free(sit_entry_set_slab, ses);
2287 }
2288 
2289 static void adjust_sit_entry_set(struct sit_entry_set *ses,
2290 						struct list_head *head)
2291 {
2292 	struct sit_entry_set *next = ses;
2293 
2294 	if (list_is_last(&ses->set_list, head))
2295 		return;
2296 
2297 	list_for_each_entry_continue(next, head, set_list)
2298 		if (ses->entry_cnt <= next->entry_cnt)
2299 			break;
2300 
2301 	list_move_tail(&ses->set_list, &next->set_list);
2302 }
2303 
2304 static void add_sit_entry(unsigned int segno, struct list_head *head)
2305 {
2306 	struct sit_entry_set *ses;
2307 	unsigned int start_segno = START_SEGNO(segno);
2308 
2309 	list_for_each_entry(ses, head, set_list) {
2310 		if (ses->start_segno == start_segno) {
2311 			ses->entry_cnt++;
2312 			adjust_sit_entry_set(ses, head);
2313 			return;
2314 		}
2315 	}
2316 
2317 	ses = grab_sit_entry_set();
2318 
2319 	ses->start_segno = start_segno;
2320 	ses->entry_cnt++;
2321 	list_add(&ses->set_list, head);
2322 }
2323 
2324 static void add_sits_in_set(struct f2fs_sb_info *sbi)
2325 {
2326 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2327 	struct list_head *set_list = &sm_info->sit_entry_set;
2328 	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
2329 	unsigned int segno;
2330 
2331 	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
2332 		add_sit_entry(segno, set_list);
2333 }
2334 
2335 static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
2336 {
2337 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2338 	struct f2fs_journal *journal = curseg->journal;
2339 	int i;
2340 
2341 	down_write(&curseg->journal_rwsem);
2342 	for (i = 0; i < sits_in_cursum(journal); i++) {
2343 		unsigned int segno;
2344 		bool dirtied;
2345 
2346 		segno = le32_to_cpu(segno_in_journal(journal, i));
2347 		dirtied = __mark_sit_entry_dirty(sbi, segno);
2348 
2349 		if (!dirtied)
2350 			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
2351 	}
2352 	update_sits_in_cursum(journal, -i);
2353 	up_write(&curseg->journal_rwsem);
2354 }
2355 
2356 /*
2357  * CP calls this function, which flushes SIT entries including sit_journal,
2358  * and moves prefree segs to free segs.
2359  */
2360 void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
2361 {
2362 	struct sit_info *sit_i = SIT_I(sbi);
2363 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
2364 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2365 	struct f2fs_journal *journal = curseg->journal;
2366 	struct sit_entry_set *ses, *tmp;
2367 	struct list_head *head = &SM_I(sbi)->sit_entry_set;
2368 	bool to_journal = true;
2369 	struct seg_entry *se;
2370 
2371 	mutex_lock(&sit_i->sentry_lock);
2372 
2373 	if (!sit_i->dirty_sentries)
2374 		goto out;
2375 
2376 	/*
2377 	 * add and account sit entries of dirty bitmap in sit entry
2378 	 * set temporarily
2379 	 */
2380 	add_sits_in_set(sbi);
2381 
2382 	/*
2383 	 * if there are no enough space in journal to store dirty sit
2384 	 * entries, remove all entries from journal and add and account
2385 	 * them in sit entry set.
2386 	 */
2387 	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
2388 		remove_sits_in_journal(sbi);
2389 
2390 	/*
2391 	 * there are two steps to flush sit entries:
2392 	 * #1, flush sit entries to journal in current cold data summary block.
2393 	 * #2, flush sit entries to sit page.
2394 	 */
2395 	list_for_each_entry_safe(ses, tmp, head, set_list) {
2396 		struct page *page = NULL;
2397 		struct f2fs_sit_block *raw_sit = NULL;
2398 		unsigned int start_segno = ses->start_segno;
2399 		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
2400 						(unsigned long)MAIN_SEGS(sbi));
2401 		unsigned int segno = start_segno;
2402 
2403 		if (to_journal &&
2404 			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
2405 			to_journal = false;
2406 
2407 		if (to_journal) {
2408 			down_write(&curseg->journal_rwsem);
2409 		} else {
2410 			page = get_next_sit_page(sbi, start_segno);
2411 			raw_sit = page_address(page);
2412 		}
2413 
2414 		/* flush dirty sit entries in region of current sit set */
2415 		for_each_set_bit_from(segno, bitmap, end) {
2416 			int offset, sit_offset;
2417 
2418 			se = get_seg_entry(sbi, segno);
2419 
2420 			/* add discard candidates */
2421 			if (cpc->reason != CP_DISCARD) {
2422 				cpc->trim_start = segno;
2423 				add_discard_addrs(sbi, cpc, false);
2424 			}
2425 
2426 			if (to_journal) {
2427 				offset = lookup_journal_in_cursum(journal,
2428 							SIT_JOURNAL, segno, 1);
2429 				f2fs_bug_on(sbi, offset < 0);
2430 				segno_in_journal(journal, offset) =
2431 							cpu_to_le32(segno);
2432 				seg_info_to_raw_sit(se,
2433 					&sit_in_journal(journal, offset));
2434 			} else {
2435 				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
2436 				seg_info_to_raw_sit(se,
2437 						&raw_sit->entries[sit_offset]);
2438 			}
2439 
2440 			__clear_bit(segno, bitmap);
2441 			sit_i->dirty_sentries--;
2442 			ses->entry_cnt--;
2443 		}
2444 
2445 		if (to_journal)
2446 			up_write(&curseg->journal_rwsem);
2447 		else
2448 			f2fs_put_page(page, 1);
2449 
2450 		f2fs_bug_on(sbi, ses->entry_cnt);
2451 		release_sit_entry_set(ses);
2452 	}
2453 
2454 	f2fs_bug_on(sbi, !list_empty(head));
2455 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
2456 out:
2457 	if (cpc->reason == CP_DISCARD) {
2458 		__u64 trim_start = cpc->trim_start;
2459 
2460 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
2461 			add_discard_addrs(sbi, cpc, false);
2462 
2463 		cpc->trim_start = trim_start;
2464 	}
2465 	mutex_unlock(&sit_i->sentry_lock);
2466 
2467 	set_prefree_as_free_segments(sbi);
2468 }
2469 
2470 static int build_sit_info(struct f2fs_sb_info *sbi)
2471 {
2472 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2473 	struct sit_info *sit_i;
2474 	unsigned int sit_segs, start;
2475 	char *src_bitmap;
2476 	unsigned int bitmap_size;
2477 
2478 	/* allocate memory for SIT information */
2479 	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
2480 	if (!sit_i)
2481 		return -ENOMEM;
2482 
2483 	SM_I(sbi)->sit_info = sit_i;
2484 
2485 	sit_i->sentries = f2fs_kvzalloc(MAIN_SEGS(sbi) *
2486 					sizeof(struct seg_entry), GFP_KERNEL);
2487 	if (!sit_i->sentries)
2488 		return -ENOMEM;
2489 
2490 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2491 	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2492 	if (!sit_i->dirty_sentries_bitmap)
2493 		return -ENOMEM;
2494 
2495 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2496 		sit_i->sentries[start].cur_valid_map
2497 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2498 		sit_i->sentries[start].ckpt_valid_map
2499 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2500 		if (!sit_i->sentries[start].cur_valid_map ||
2501 				!sit_i->sentries[start].ckpt_valid_map)
2502 			return -ENOMEM;
2503 
2504 #ifdef CONFIG_F2FS_CHECK_FS
2505 		sit_i->sentries[start].cur_valid_map_mir
2506 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2507 		if (!sit_i->sentries[start].cur_valid_map_mir)
2508 			return -ENOMEM;
2509 #endif
2510 
2511 		if (f2fs_discard_en(sbi)) {
2512 			sit_i->sentries[start].discard_map
2513 				= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2514 			if (!sit_i->sentries[start].discard_map)
2515 				return -ENOMEM;
2516 		}
2517 	}
2518 
2519 	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2520 	if (!sit_i->tmp_map)
2521 		return -ENOMEM;
2522 
2523 	if (sbi->segs_per_sec > 1) {
2524 		sit_i->sec_entries = f2fs_kvzalloc(MAIN_SECS(sbi) *
2525 					sizeof(struct sec_entry), GFP_KERNEL);
2526 		if (!sit_i->sec_entries)
2527 			return -ENOMEM;
2528 	}
2529 
2530 	/* get information related with SIT */
2531 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
2532 
2533 	/* setup SIT bitmap from ckeckpoint pack */
2534 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
2535 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
2536 
2537 	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2538 	if (!sit_i->sit_bitmap)
2539 		return -ENOMEM;
2540 
2541 #ifdef CONFIG_F2FS_CHECK_FS
2542 	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2543 	if (!sit_i->sit_bitmap_mir)
2544 		return -ENOMEM;
2545 #endif
2546 
2547 	/* init SIT information */
2548 	sit_i->s_ops = &default_salloc_ops;
2549 
2550 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
2551 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
2552 	sit_i->written_valid_blocks = 0;
2553 	sit_i->bitmap_size = bitmap_size;
2554 	sit_i->dirty_sentries = 0;
2555 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
2556 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
2557 	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
2558 	mutex_init(&sit_i->sentry_lock);
2559 	return 0;
2560 }
2561 
2562 static int build_free_segmap(struct f2fs_sb_info *sbi)
2563 {
2564 	struct free_segmap_info *free_i;
2565 	unsigned int bitmap_size, sec_bitmap_size;
2566 
2567 	/* allocate memory for free segmap information */
2568 	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
2569 	if (!free_i)
2570 		return -ENOMEM;
2571 
2572 	SM_I(sbi)->free_info = free_i;
2573 
2574 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2575 	free_i->free_segmap = f2fs_kvmalloc(bitmap_size, GFP_KERNEL);
2576 	if (!free_i->free_segmap)
2577 		return -ENOMEM;
2578 
2579 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2580 	free_i->free_secmap = f2fs_kvmalloc(sec_bitmap_size, GFP_KERNEL);
2581 	if (!free_i->free_secmap)
2582 		return -ENOMEM;
2583 
2584 	/* set all segments as dirty temporarily */
2585 	memset(free_i->free_segmap, 0xff, bitmap_size);
2586 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
2587 
2588 	/* init free segmap information */
2589 	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
2590 	free_i->free_segments = 0;
2591 	free_i->free_sections = 0;
2592 	spin_lock_init(&free_i->segmap_lock);
2593 	return 0;
2594 }
2595 
2596 static int build_curseg(struct f2fs_sb_info *sbi)
2597 {
2598 	struct curseg_info *array;
2599 	int i;
2600 
2601 	array = kcalloc(NR_CURSEG_TYPE, sizeof(*array), GFP_KERNEL);
2602 	if (!array)
2603 		return -ENOMEM;
2604 
2605 	SM_I(sbi)->curseg_array = array;
2606 
2607 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2608 		mutex_init(&array[i].curseg_mutex);
2609 		array[i].sum_blk = kzalloc(PAGE_SIZE, GFP_KERNEL);
2610 		if (!array[i].sum_blk)
2611 			return -ENOMEM;
2612 		init_rwsem(&array[i].journal_rwsem);
2613 		array[i].journal = kzalloc(sizeof(struct f2fs_journal),
2614 							GFP_KERNEL);
2615 		if (!array[i].journal)
2616 			return -ENOMEM;
2617 		array[i].segno = NULL_SEGNO;
2618 		array[i].next_blkoff = 0;
2619 	}
2620 	return restore_curseg_summaries(sbi);
2621 }
2622 
2623 static void build_sit_entries(struct f2fs_sb_info *sbi)
2624 {
2625 	struct sit_info *sit_i = SIT_I(sbi);
2626 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2627 	struct f2fs_journal *journal = curseg->journal;
2628 	struct seg_entry *se;
2629 	struct f2fs_sit_entry sit;
2630 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
2631 	unsigned int i, start, end;
2632 	unsigned int readed, start_blk = 0;
2633 
2634 	do {
2635 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
2636 							META_SIT, true);
2637 
2638 		start = start_blk * sit_i->sents_per_block;
2639 		end = (start_blk + readed) * sit_i->sents_per_block;
2640 
2641 		for (; start < end && start < MAIN_SEGS(sbi); start++) {
2642 			struct f2fs_sit_block *sit_blk;
2643 			struct page *page;
2644 
2645 			se = &sit_i->sentries[start];
2646 			page = get_current_sit_page(sbi, start);
2647 			sit_blk = (struct f2fs_sit_block *)page_address(page);
2648 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
2649 			f2fs_put_page(page, 1);
2650 
2651 			check_block_count(sbi, start, &sit);
2652 			seg_info_from_raw_sit(se, &sit);
2653 
2654 			/* build discard map only one time */
2655 			if (f2fs_discard_en(sbi)) {
2656 				memcpy(se->discard_map, se->cur_valid_map,
2657 							SIT_VBLOCK_MAP_SIZE);
2658 				sbi->discard_blks += sbi->blocks_per_seg -
2659 							se->valid_blocks;
2660 			}
2661 
2662 			if (sbi->segs_per_sec > 1)
2663 				get_sec_entry(sbi, start)->valid_blocks +=
2664 							se->valid_blocks;
2665 		}
2666 		start_blk += readed;
2667 	} while (start_blk < sit_blk_cnt);
2668 
2669 	down_read(&curseg->journal_rwsem);
2670 	for (i = 0; i < sits_in_cursum(journal); i++) {
2671 		unsigned int old_valid_blocks;
2672 
2673 		start = le32_to_cpu(segno_in_journal(journal, i));
2674 		se = &sit_i->sentries[start];
2675 		sit = sit_in_journal(journal, i);
2676 
2677 		old_valid_blocks = se->valid_blocks;
2678 
2679 		check_block_count(sbi, start, &sit);
2680 		seg_info_from_raw_sit(se, &sit);
2681 
2682 		if (f2fs_discard_en(sbi)) {
2683 			memcpy(se->discard_map, se->cur_valid_map,
2684 						SIT_VBLOCK_MAP_SIZE);
2685 			sbi->discard_blks += old_valid_blocks -
2686 						se->valid_blocks;
2687 		}
2688 
2689 		if (sbi->segs_per_sec > 1)
2690 			get_sec_entry(sbi, start)->valid_blocks +=
2691 				se->valid_blocks - old_valid_blocks;
2692 	}
2693 	up_read(&curseg->journal_rwsem);
2694 }
2695 
2696 static void init_free_segmap(struct f2fs_sb_info *sbi)
2697 {
2698 	unsigned int start;
2699 	int type;
2700 
2701 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2702 		struct seg_entry *sentry = get_seg_entry(sbi, start);
2703 		if (!sentry->valid_blocks)
2704 			__set_free(sbi, start);
2705 		else
2706 			SIT_I(sbi)->written_valid_blocks +=
2707 						sentry->valid_blocks;
2708 	}
2709 
2710 	/* set use the current segments */
2711 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
2712 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
2713 		__set_test_and_inuse(sbi, curseg_t->segno);
2714 	}
2715 }
2716 
2717 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
2718 {
2719 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2720 	struct free_segmap_info *free_i = FREE_I(sbi);
2721 	unsigned int segno = 0, offset = 0;
2722 	unsigned short valid_blocks;
2723 
2724 	while (1) {
2725 		/* find dirty segment based on free segmap */
2726 		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
2727 		if (segno >= MAIN_SEGS(sbi))
2728 			break;
2729 		offset = segno + 1;
2730 		valid_blocks = get_valid_blocks(sbi, segno, 0);
2731 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
2732 			continue;
2733 		if (valid_blocks > sbi->blocks_per_seg) {
2734 			f2fs_bug_on(sbi, 1);
2735 			continue;
2736 		}
2737 		mutex_lock(&dirty_i->seglist_lock);
2738 		__locate_dirty_segment(sbi, segno, DIRTY);
2739 		mutex_unlock(&dirty_i->seglist_lock);
2740 	}
2741 }
2742 
2743 static int init_victim_secmap(struct f2fs_sb_info *sbi)
2744 {
2745 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2746 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2747 
2748 	dirty_i->victim_secmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2749 	if (!dirty_i->victim_secmap)
2750 		return -ENOMEM;
2751 	return 0;
2752 }
2753 
2754 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
2755 {
2756 	struct dirty_seglist_info *dirty_i;
2757 	unsigned int bitmap_size, i;
2758 
2759 	/* allocate memory for dirty segments list information */
2760 	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
2761 	if (!dirty_i)
2762 		return -ENOMEM;
2763 
2764 	SM_I(sbi)->dirty_info = dirty_i;
2765 	mutex_init(&dirty_i->seglist_lock);
2766 
2767 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2768 
2769 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
2770 		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2771 		if (!dirty_i->dirty_segmap[i])
2772 			return -ENOMEM;
2773 	}
2774 
2775 	init_dirty_segmap(sbi);
2776 	return init_victim_secmap(sbi);
2777 }
2778 
2779 /*
2780  * Update min, max modified time for cost-benefit GC algorithm
2781  */
2782 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
2783 {
2784 	struct sit_info *sit_i = SIT_I(sbi);
2785 	unsigned int segno;
2786 
2787 	mutex_lock(&sit_i->sentry_lock);
2788 
2789 	sit_i->min_mtime = LLONG_MAX;
2790 
2791 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
2792 		unsigned int i;
2793 		unsigned long long mtime = 0;
2794 
2795 		for (i = 0; i < sbi->segs_per_sec; i++)
2796 			mtime += get_seg_entry(sbi, segno + i)->mtime;
2797 
2798 		mtime = div_u64(mtime, sbi->segs_per_sec);
2799 
2800 		if (sit_i->min_mtime > mtime)
2801 			sit_i->min_mtime = mtime;
2802 	}
2803 	sit_i->max_mtime = get_mtime(sbi);
2804 	mutex_unlock(&sit_i->sentry_lock);
2805 }
2806 
2807 int build_segment_manager(struct f2fs_sb_info *sbi)
2808 {
2809 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2810 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2811 	struct f2fs_sm_info *sm_info;
2812 	int err;
2813 
2814 	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
2815 	if (!sm_info)
2816 		return -ENOMEM;
2817 
2818 	/* init sm info */
2819 	sbi->sm_info = sm_info;
2820 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
2821 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
2822 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
2823 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
2824 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
2825 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
2826 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
2827 	sm_info->rec_prefree_segments = sm_info->main_segments *
2828 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
2829 	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
2830 		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
2831 
2832 	if (!test_opt(sbi, LFS))
2833 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
2834 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
2835 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
2836 
2837 	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
2838 
2839 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
2840 
2841 	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
2842 		err = create_flush_cmd_control(sbi);
2843 		if (err)
2844 			return err;
2845 	}
2846 
2847 	err = create_discard_cmd_control(sbi);
2848 	if (err)
2849 		return err;
2850 
2851 	err = build_sit_info(sbi);
2852 	if (err)
2853 		return err;
2854 	err = build_free_segmap(sbi);
2855 	if (err)
2856 		return err;
2857 	err = build_curseg(sbi);
2858 	if (err)
2859 		return err;
2860 
2861 	/* reinit free segmap based on SIT */
2862 	build_sit_entries(sbi);
2863 
2864 	init_free_segmap(sbi);
2865 	err = build_dirty_segmap(sbi);
2866 	if (err)
2867 		return err;
2868 
2869 	init_min_max_mtime(sbi);
2870 	return 0;
2871 }
2872 
2873 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
2874 		enum dirty_type dirty_type)
2875 {
2876 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2877 
2878 	mutex_lock(&dirty_i->seglist_lock);
2879 	kvfree(dirty_i->dirty_segmap[dirty_type]);
2880 	dirty_i->nr_dirty[dirty_type] = 0;
2881 	mutex_unlock(&dirty_i->seglist_lock);
2882 }
2883 
2884 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
2885 {
2886 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2887 	kvfree(dirty_i->victim_secmap);
2888 }
2889 
2890 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
2891 {
2892 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2893 	int i;
2894 
2895 	if (!dirty_i)
2896 		return;
2897 
2898 	/* discard pre-free/dirty segments list */
2899 	for (i = 0; i < NR_DIRTY_TYPE; i++)
2900 		discard_dirty_segmap(sbi, i);
2901 
2902 	destroy_victim_secmap(sbi);
2903 	SM_I(sbi)->dirty_info = NULL;
2904 	kfree(dirty_i);
2905 }
2906 
2907 static void destroy_curseg(struct f2fs_sb_info *sbi)
2908 {
2909 	struct curseg_info *array = SM_I(sbi)->curseg_array;
2910 	int i;
2911 
2912 	if (!array)
2913 		return;
2914 	SM_I(sbi)->curseg_array = NULL;
2915 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2916 		kfree(array[i].sum_blk);
2917 		kfree(array[i].journal);
2918 	}
2919 	kfree(array);
2920 }
2921 
2922 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
2923 {
2924 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
2925 	if (!free_i)
2926 		return;
2927 	SM_I(sbi)->free_info = NULL;
2928 	kvfree(free_i->free_segmap);
2929 	kvfree(free_i->free_secmap);
2930 	kfree(free_i);
2931 }
2932 
2933 static void destroy_sit_info(struct f2fs_sb_info *sbi)
2934 {
2935 	struct sit_info *sit_i = SIT_I(sbi);
2936 	unsigned int start;
2937 
2938 	if (!sit_i)
2939 		return;
2940 
2941 	if (sit_i->sentries) {
2942 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
2943 			kfree(sit_i->sentries[start].cur_valid_map);
2944 #ifdef CONFIG_F2FS_CHECK_FS
2945 			kfree(sit_i->sentries[start].cur_valid_map_mir);
2946 #endif
2947 			kfree(sit_i->sentries[start].ckpt_valid_map);
2948 			kfree(sit_i->sentries[start].discard_map);
2949 		}
2950 	}
2951 	kfree(sit_i->tmp_map);
2952 
2953 	kvfree(sit_i->sentries);
2954 	kvfree(sit_i->sec_entries);
2955 	kvfree(sit_i->dirty_sentries_bitmap);
2956 
2957 	SM_I(sbi)->sit_info = NULL;
2958 	kfree(sit_i->sit_bitmap);
2959 #ifdef CONFIG_F2FS_CHECK_FS
2960 	kfree(sit_i->sit_bitmap_mir);
2961 #endif
2962 	kfree(sit_i);
2963 }
2964 
2965 void destroy_segment_manager(struct f2fs_sb_info *sbi)
2966 {
2967 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2968 
2969 	if (!sm_info)
2970 		return;
2971 	destroy_flush_cmd_control(sbi, true);
2972 	destroy_discard_cmd_control(sbi, true);
2973 	destroy_dirty_segmap(sbi);
2974 	destroy_curseg(sbi);
2975 	destroy_free_segmap(sbi);
2976 	destroy_sit_info(sbi);
2977 	sbi->sm_info = NULL;
2978 	kfree(sm_info);
2979 }
2980 
2981 int __init create_segment_manager_caches(void)
2982 {
2983 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
2984 			sizeof(struct discard_entry));
2985 	if (!discard_entry_slab)
2986 		goto fail;
2987 
2988 	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
2989 			sizeof(struct discard_cmd));
2990 	if (!discard_cmd_slab)
2991 		goto destroy_discard_entry;
2992 
2993 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
2994 			sizeof(struct sit_entry_set));
2995 	if (!sit_entry_set_slab)
2996 		goto destroy_discard_cmd;
2997 
2998 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
2999 			sizeof(struct inmem_pages));
3000 	if (!inmem_entry_slab)
3001 		goto destroy_sit_entry_set;
3002 	return 0;
3003 
3004 destroy_sit_entry_set:
3005 	kmem_cache_destroy(sit_entry_set_slab);
3006 destroy_discard_cmd:
3007 	kmem_cache_destroy(discard_cmd_slab);
3008 destroy_discard_entry:
3009 	kmem_cache_destroy(discard_entry_slab);
3010 fail:
3011 	return -ENOMEM;
3012 }
3013 
3014 void destroy_segment_manager_caches(void)
3015 {
3016 	kmem_cache_destroy(sit_entry_set_slab);
3017 	kmem_cache_destroy(discard_cmd_slab);
3018 	kmem_cache_destroy(discard_entry_slab);
3019 	kmem_cache_destroy(inmem_entry_slab);
3020 }
3021