xref: /openbmc/linux/fs/f2fs/segment.c (revision 4f6cce39)
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 		else
1040 			end = start - 1;
1041 	}
1042 	mutex_unlock(&dirty_i->seglist_lock);
1043 
1044 	/* send small discards */
1045 	list_for_each_entry_safe(entry, this, head, list) {
1046 		if (force && entry->len < cpc->trim_minlen)
1047 			goto skip;
1048 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
1049 		cpc->trimmed += entry->len;
1050 skip:
1051 		list_del(&entry->list);
1052 		SM_I(sbi)->dcc_info->nr_discards -= entry->len;
1053 		kmem_cache_free(discard_entry_slab, entry);
1054 	}
1055 }
1056 
1057 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
1058 {
1059 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1060 	struct discard_cmd_control *dcc;
1061 	int err = 0;
1062 
1063 	if (SM_I(sbi)->dcc_info) {
1064 		dcc = SM_I(sbi)->dcc_info;
1065 		goto init_thread;
1066 	}
1067 
1068 	dcc = kzalloc(sizeof(struct discard_cmd_control), GFP_KERNEL);
1069 	if (!dcc)
1070 		return -ENOMEM;
1071 
1072 	INIT_LIST_HEAD(&dcc->discard_entry_list);
1073 	INIT_LIST_HEAD(&dcc->discard_cmd_list);
1074 	mutex_init(&dcc->cmd_lock);
1075 	atomic_set(&dcc->submit_discard, 0);
1076 	dcc->nr_discards = 0;
1077 	dcc->max_discards = 0;
1078 
1079 	init_waitqueue_head(&dcc->discard_wait_queue);
1080 	SM_I(sbi)->dcc_info = dcc;
1081 init_thread:
1082 	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
1083 				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
1084 	if (IS_ERR(dcc->f2fs_issue_discard)) {
1085 		err = PTR_ERR(dcc->f2fs_issue_discard);
1086 		kfree(dcc);
1087 		SM_I(sbi)->dcc_info = NULL;
1088 		return err;
1089 	}
1090 
1091 	return err;
1092 }
1093 
1094 static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi, bool free)
1095 {
1096 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1097 
1098 	if (dcc && dcc->f2fs_issue_discard) {
1099 		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
1100 
1101 		dcc->f2fs_issue_discard = NULL;
1102 		kthread_stop(discard_thread);
1103 	}
1104 	if (free) {
1105 		kfree(dcc);
1106 		SM_I(sbi)->dcc_info = NULL;
1107 	}
1108 }
1109 
1110 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
1111 {
1112 	struct sit_info *sit_i = SIT_I(sbi);
1113 
1114 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
1115 		sit_i->dirty_sentries++;
1116 		return false;
1117 	}
1118 
1119 	return true;
1120 }
1121 
1122 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
1123 					unsigned int segno, int modified)
1124 {
1125 	struct seg_entry *se = get_seg_entry(sbi, segno);
1126 	se->type = type;
1127 	if (modified)
1128 		__mark_sit_entry_dirty(sbi, segno);
1129 }
1130 
1131 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
1132 {
1133 	struct seg_entry *se;
1134 	unsigned int segno, offset;
1135 	long int new_vblocks;
1136 
1137 	segno = GET_SEGNO(sbi, blkaddr);
1138 
1139 	se = get_seg_entry(sbi, segno);
1140 	new_vblocks = se->valid_blocks + del;
1141 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1142 
1143 	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
1144 				(new_vblocks > sbi->blocks_per_seg)));
1145 
1146 	se->valid_blocks = new_vblocks;
1147 	se->mtime = get_mtime(sbi);
1148 	SIT_I(sbi)->max_mtime = se->mtime;
1149 
1150 	/* Update valid block bitmap */
1151 	if (del > 0) {
1152 		if (f2fs_test_and_set_bit(offset, se->cur_valid_map)) {
1153 #ifdef CONFIG_F2FS_CHECK_FS
1154 			if (f2fs_test_and_set_bit(offset,
1155 						se->cur_valid_map_mir))
1156 				f2fs_bug_on(sbi, 1);
1157 			else
1158 				WARN_ON(1);
1159 #else
1160 			f2fs_bug_on(sbi, 1);
1161 #endif
1162 		}
1163 		if (f2fs_discard_en(sbi) &&
1164 			!f2fs_test_and_set_bit(offset, se->discard_map))
1165 			sbi->discard_blks--;
1166 	} else {
1167 		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) {
1168 #ifdef CONFIG_F2FS_CHECK_FS
1169 			if (!f2fs_test_and_clear_bit(offset,
1170 						se->cur_valid_map_mir))
1171 				f2fs_bug_on(sbi, 1);
1172 			else
1173 				WARN_ON(1);
1174 #else
1175 			f2fs_bug_on(sbi, 1);
1176 #endif
1177 		}
1178 		if (f2fs_discard_en(sbi) &&
1179 			f2fs_test_and_clear_bit(offset, se->discard_map))
1180 			sbi->discard_blks++;
1181 	}
1182 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
1183 		se->ckpt_valid_blocks += del;
1184 
1185 	__mark_sit_entry_dirty(sbi, segno);
1186 
1187 	/* update total number of valid blocks to be written in ckpt area */
1188 	SIT_I(sbi)->written_valid_blocks += del;
1189 
1190 	if (sbi->segs_per_sec > 1)
1191 		get_sec_entry(sbi, segno)->valid_blocks += del;
1192 }
1193 
1194 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
1195 {
1196 	update_sit_entry(sbi, new, 1);
1197 	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
1198 		update_sit_entry(sbi, old, -1);
1199 
1200 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
1201 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
1202 }
1203 
1204 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
1205 {
1206 	unsigned int segno = GET_SEGNO(sbi, addr);
1207 	struct sit_info *sit_i = SIT_I(sbi);
1208 
1209 	f2fs_bug_on(sbi, addr == NULL_ADDR);
1210 	if (addr == NEW_ADDR)
1211 		return;
1212 
1213 	/* add it into sit main buffer */
1214 	mutex_lock(&sit_i->sentry_lock);
1215 
1216 	update_sit_entry(sbi, addr, -1);
1217 
1218 	/* add it into dirty seglist */
1219 	locate_dirty_segment(sbi, segno);
1220 
1221 	mutex_unlock(&sit_i->sentry_lock);
1222 }
1223 
1224 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
1225 {
1226 	struct sit_info *sit_i = SIT_I(sbi);
1227 	unsigned int segno, offset;
1228 	struct seg_entry *se;
1229 	bool is_cp = false;
1230 
1231 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1232 		return true;
1233 
1234 	mutex_lock(&sit_i->sentry_lock);
1235 
1236 	segno = GET_SEGNO(sbi, blkaddr);
1237 	se = get_seg_entry(sbi, segno);
1238 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1239 
1240 	if (f2fs_test_bit(offset, se->ckpt_valid_map))
1241 		is_cp = true;
1242 
1243 	mutex_unlock(&sit_i->sentry_lock);
1244 
1245 	return is_cp;
1246 }
1247 
1248 /*
1249  * This function should be resided under the curseg_mutex lock
1250  */
1251 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
1252 					struct f2fs_summary *sum)
1253 {
1254 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1255 	void *addr = curseg->sum_blk;
1256 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
1257 	memcpy(addr, sum, sizeof(struct f2fs_summary));
1258 }
1259 
1260 /*
1261  * Calculate the number of current summary pages for writing
1262  */
1263 int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
1264 {
1265 	int valid_sum_count = 0;
1266 	int i, sum_in_page;
1267 
1268 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1269 		if (sbi->ckpt->alloc_type[i] == SSR)
1270 			valid_sum_count += sbi->blocks_per_seg;
1271 		else {
1272 			if (for_ra)
1273 				valid_sum_count += le16_to_cpu(
1274 					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
1275 			else
1276 				valid_sum_count += curseg_blkoff(sbi, i);
1277 		}
1278 	}
1279 
1280 	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
1281 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
1282 	if (valid_sum_count <= sum_in_page)
1283 		return 1;
1284 	else if ((valid_sum_count - sum_in_page) <=
1285 		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
1286 		return 2;
1287 	return 3;
1288 }
1289 
1290 /*
1291  * Caller should put this summary page
1292  */
1293 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
1294 {
1295 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
1296 }
1297 
1298 void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
1299 {
1300 	struct page *page = grab_meta_page(sbi, blk_addr);
1301 	void *dst = page_address(page);
1302 
1303 	if (src)
1304 		memcpy(dst, src, PAGE_SIZE);
1305 	else
1306 		memset(dst, 0, PAGE_SIZE);
1307 	set_page_dirty(page);
1308 	f2fs_put_page(page, 1);
1309 }
1310 
1311 static void write_sum_page(struct f2fs_sb_info *sbi,
1312 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
1313 {
1314 	update_meta_page(sbi, (void *)sum_blk, blk_addr);
1315 }
1316 
1317 static void write_current_sum_page(struct f2fs_sb_info *sbi,
1318 						int type, block_t blk_addr)
1319 {
1320 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1321 	struct page *page = grab_meta_page(sbi, blk_addr);
1322 	struct f2fs_summary_block *src = curseg->sum_blk;
1323 	struct f2fs_summary_block *dst;
1324 
1325 	dst = (struct f2fs_summary_block *)page_address(page);
1326 
1327 	mutex_lock(&curseg->curseg_mutex);
1328 
1329 	down_read(&curseg->journal_rwsem);
1330 	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
1331 	up_read(&curseg->journal_rwsem);
1332 
1333 	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
1334 	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
1335 
1336 	mutex_unlock(&curseg->curseg_mutex);
1337 
1338 	set_page_dirty(page);
1339 	f2fs_put_page(page, 1);
1340 }
1341 
1342 /*
1343  * Find a new segment from the free segments bitmap to right order
1344  * This function should be returned with success, otherwise BUG
1345  */
1346 static void get_new_segment(struct f2fs_sb_info *sbi,
1347 			unsigned int *newseg, bool new_sec, int dir)
1348 {
1349 	struct free_segmap_info *free_i = FREE_I(sbi);
1350 	unsigned int segno, secno, zoneno;
1351 	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
1352 	unsigned int hint = *newseg / sbi->segs_per_sec;
1353 	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
1354 	unsigned int left_start = hint;
1355 	bool init = true;
1356 	int go_left = 0;
1357 	int i;
1358 
1359 	spin_lock(&free_i->segmap_lock);
1360 
1361 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
1362 		segno = find_next_zero_bit(free_i->free_segmap,
1363 				(hint + 1) * sbi->segs_per_sec, *newseg + 1);
1364 		if (segno < (hint + 1) * sbi->segs_per_sec)
1365 			goto got_it;
1366 	}
1367 find_other_zone:
1368 	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
1369 	if (secno >= MAIN_SECS(sbi)) {
1370 		if (dir == ALLOC_RIGHT) {
1371 			secno = find_next_zero_bit(free_i->free_secmap,
1372 							MAIN_SECS(sbi), 0);
1373 			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
1374 		} else {
1375 			go_left = 1;
1376 			left_start = hint - 1;
1377 		}
1378 	}
1379 	if (go_left == 0)
1380 		goto skip_left;
1381 
1382 	while (test_bit(left_start, free_i->free_secmap)) {
1383 		if (left_start > 0) {
1384 			left_start--;
1385 			continue;
1386 		}
1387 		left_start = find_next_zero_bit(free_i->free_secmap,
1388 							MAIN_SECS(sbi), 0);
1389 		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
1390 		break;
1391 	}
1392 	secno = left_start;
1393 skip_left:
1394 	hint = secno;
1395 	segno = secno * sbi->segs_per_sec;
1396 	zoneno = secno / sbi->secs_per_zone;
1397 
1398 	/* give up on finding another zone */
1399 	if (!init)
1400 		goto got_it;
1401 	if (sbi->secs_per_zone == 1)
1402 		goto got_it;
1403 	if (zoneno == old_zoneno)
1404 		goto got_it;
1405 	if (dir == ALLOC_LEFT) {
1406 		if (!go_left && zoneno + 1 >= total_zones)
1407 			goto got_it;
1408 		if (go_left && zoneno == 0)
1409 			goto got_it;
1410 	}
1411 	for (i = 0; i < NR_CURSEG_TYPE; i++)
1412 		if (CURSEG_I(sbi, i)->zone == zoneno)
1413 			break;
1414 
1415 	if (i < NR_CURSEG_TYPE) {
1416 		/* zone is in user, try another */
1417 		if (go_left)
1418 			hint = zoneno * sbi->secs_per_zone - 1;
1419 		else if (zoneno + 1 >= total_zones)
1420 			hint = 0;
1421 		else
1422 			hint = (zoneno + 1) * sbi->secs_per_zone;
1423 		init = false;
1424 		goto find_other_zone;
1425 	}
1426 got_it:
1427 	/* set it as dirty segment in free segmap */
1428 	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
1429 	__set_inuse(sbi, segno);
1430 	*newseg = segno;
1431 	spin_unlock(&free_i->segmap_lock);
1432 }
1433 
1434 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
1435 {
1436 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1437 	struct summary_footer *sum_footer;
1438 
1439 	curseg->segno = curseg->next_segno;
1440 	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
1441 	curseg->next_blkoff = 0;
1442 	curseg->next_segno = NULL_SEGNO;
1443 
1444 	sum_footer = &(curseg->sum_blk->footer);
1445 	memset(sum_footer, 0, sizeof(struct summary_footer));
1446 	if (IS_DATASEG(type))
1447 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
1448 	if (IS_NODESEG(type))
1449 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
1450 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
1451 }
1452 
1453 /*
1454  * Allocate a current working segment.
1455  * This function always allocates a free segment in LFS manner.
1456  */
1457 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
1458 {
1459 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1460 	unsigned int segno = curseg->segno;
1461 	int dir = ALLOC_LEFT;
1462 
1463 	write_sum_page(sbi, curseg->sum_blk,
1464 				GET_SUM_BLOCK(sbi, segno));
1465 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
1466 		dir = ALLOC_RIGHT;
1467 
1468 	if (test_opt(sbi, NOHEAP))
1469 		dir = ALLOC_RIGHT;
1470 
1471 	get_new_segment(sbi, &segno, new_sec, dir);
1472 	curseg->next_segno = segno;
1473 	reset_curseg(sbi, type, 1);
1474 	curseg->alloc_type = LFS;
1475 }
1476 
1477 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
1478 			struct curseg_info *seg, block_t start)
1479 {
1480 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
1481 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1482 	unsigned long *target_map = SIT_I(sbi)->tmp_map;
1483 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1484 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1485 	int i, pos;
1486 
1487 	for (i = 0; i < entries; i++)
1488 		target_map[i] = ckpt_map[i] | cur_map[i];
1489 
1490 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
1491 
1492 	seg->next_blkoff = pos;
1493 }
1494 
1495 /*
1496  * If a segment is written by LFS manner, next block offset is just obtained
1497  * by increasing the current block offset. However, if a segment is written by
1498  * SSR manner, next block offset obtained by calling __next_free_blkoff
1499  */
1500 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
1501 				struct curseg_info *seg)
1502 {
1503 	if (seg->alloc_type == SSR)
1504 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
1505 	else
1506 		seg->next_blkoff++;
1507 }
1508 
1509 /*
1510  * This function always allocates a used segment(from dirty seglist) by SSR
1511  * manner, so it should recover the existing segment information of valid blocks
1512  */
1513 static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
1514 {
1515 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1516 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1517 	unsigned int new_segno = curseg->next_segno;
1518 	struct f2fs_summary_block *sum_node;
1519 	struct page *sum_page;
1520 
1521 	write_sum_page(sbi, curseg->sum_blk,
1522 				GET_SUM_BLOCK(sbi, curseg->segno));
1523 	__set_test_and_inuse(sbi, new_segno);
1524 
1525 	mutex_lock(&dirty_i->seglist_lock);
1526 	__remove_dirty_segment(sbi, new_segno, PRE);
1527 	__remove_dirty_segment(sbi, new_segno, DIRTY);
1528 	mutex_unlock(&dirty_i->seglist_lock);
1529 
1530 	reset_curseg(sbi, type, 1);
1531 	curseg->alloc_type = SSR;
1532 	__next_free_blkoff(sbi, curseg, 0);
1533 
1534 	if (reuse) {
1535 		sum_page = get_sum_page(sbi, new_segno);
1536 		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
1537 		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
1538 		f2fs_put_page(sum_page, 1);
1539 	}
1540 }
1541 
1542 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
1543 {
1544 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1545 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
1546 	int i, cnt;
1547 	bool reversed = false;
1548 
1549 	/* need_SSR() already forces to do this */
1550 	if (v_ops->get_victim(sbi, &(curseg)->next_segno, BG_GC, type, SSR))
1551 		return 1;
1552 
1553 	/* For node segments, let's do SSR more intensively */
1554 	if (IS_NODESEG(type)) {
1555 		if (type >= CURSEG_WARM_NODE) {
1556 			reversed = true;
1557 			i = CURSEG_COLD_NODE;
1558 		} else {
1559 			i = CURSEG_HOT_NODE;
1560 		}
1561 		cnt = NR_CURSEG_NODE_TYPE;
1562 	} else {
1563 		if (type >= CURSEG_WARM_DATA) {
1564 			reversed = true;
1565 			i = CURSEG_COLD_DATA;
1566 		} else {
1567 			i = CURSEG_HOT_DATA;
1568 		}
1569 		cnt = NR_CURSEG_DATA_TYPE;
1570 	}
1571 
1572 	for (; cnt-- > 0; reversed ? i-- : i++) {
1573 		if (i == type)
1574 			continue;
1575 		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
1576 						BG_GC, i, SSR))
1577 			return 1;
1578 	}
1579 	return 0;
1580 }
1581 
1582 /*
1583  * flush out current segment and replace it with new segment
1584  * This function should be returned with success, otherwise BUG
1585  */
1586 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
1587 						int type, bool force)
1588 {
1589 	if (force)
1590 		new_curseg(sbi, type, true);
1591 	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
1592 					type == CURSEG_WARM_NODE)
1593 		new_curseg(sbi, type, false);
1594 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
1595 		change_curseg(sbi, type, true);
1596 	else
1597 		new_curseg(sbi, type, false);
1598 
1599 	stat_inc_seg_type(sbi, CURSEG_I(sbi, type));
1600 }
1601 
1602 void allocate_new_segments(struct f2fs_sb_info *sbi)
1603 {
1604 	struct curseg_info *curseg;
1605 	unsigned int old_segno;
1606 	int i;
1607 
1608 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1609 		curseg = CURSEG_I(sbi, i);
1610 		old_segno = curseg->segno;
1611 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
1612 		locate_dirty_segment(sbi, old_segno);
1613 	}
1614 }
1615 
1616 static const struct segment_allocation default_salloc_ops = {
1617 	.allocate_segment = allocate_segment_by_default,
1618 };
1619 
1620 bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1621 {
1622 	__u64 trim_start = cpc->trim_start;
1623 	bool has_candidate = false;
1624 
1625 	mutex_lock(&SIT_I(sbi)->sentry_lock);
1626 	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
1627 		if (add_discard_addrs(sbi, cpc, true)) {
1628 			has_candidate = true;
1629 			break;
1630 		}
1631 	}
1632 	mutex_unlock(&SIT_I(sbi)->sentry_lock);
1633 
1634 	cpc->trim_start = trim_start;
1635 	return has_candidate;
1636 }
1637 
1638 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
1639 {
1640 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
1641 	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
1642 	unsigned int start_segno, end_segno;
1643 	struct cp_control cpc;
1644 	int err = 0;
1645 
1646 	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
1647 		return -EINVAL;
1648 
1649 	cpc.trimmed = 0;
1650 	if (end <= MAIN_BLKADDR(sbi))
1651 		goto out;
1652 
1653 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1654 		f2fs_msg(sbi->sb, KERN_WARNING,
1655 			"Found FS corruption, run fsck to fix.");
1656 		goto out;
1657 	}
1658 
1659 	/* start/end segment number in main_area */
1660 	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
1661 	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
1662 						GET_SEGNO(sbi, end);
1663 	cpc.reason = CP_DISCARD;
1664 	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
1665 
1666 	/* do checkpoint to issue discard commands safely */
1667 	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
1668 		cpc.trim_start = start_segno;
1669 
1670 		if (sbi->discard_blks == 0)
1671 			break;
1672 		else if (sbi->discard_blks < BATCHED_TRIM_BLOCKS(sbi))
1673 			cpc.trim_end = end_segno;
1674 		else
1675 			cpc.trim_end = min_t(unsigned int,
1676 				rounddown(start_segno +
1677 				BATCHED_TRIM_SEGMENTS(sbi),
1678 				sbi->segs_per_sec) - 1, end_segno);
1679 
1680 		mutex_lock(&sbi->gc_mutex);
1681 		err = write_checkpoint(sbi, &cpc);
1682 		mutex_unlock(&sbi->gc_mutex);
1683 		if (err)
1684 			break;
1685 
1686 		schedule();
1687 	}
1688 out:
1689 	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
1690 	return err;
1691 }
1692 
1693 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
1694 {
1695 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1696 	if (curseg->next_blkoff < sbi->blocks_per_seg)
1697 		return true;
1698 	return false;
1699 }
1700 
1701 static int __get_segment_type_2(struct page *page, enum page_type p_type)
1702 {
1703 	if (p_type == DATA)
1704 		return CURSEG_HOT_DATA;
1705 	else
1706 		return CURSEG_HOT_NODE;
1707 }
1708 
1709 static int __get_segment_type_4(struct page *page, enum page_type p_type)
1710 {
1711 	if (p_type == DATA) {
1712 		struct inode *inode = page->mapping->host;
1713 
1714 		if (S_ISDIR(inode->i_mode))
1715 			return CURSEG_HOT_DATA;
1716 		else
1717 			return CURSEG_COLD_DATA;
1718 	} else {
1719 		if (IS_DNODE(page) && is_cold_node(page))
1720 			return CURSEG_WARM_NODE;
1721 		else
1722 			return CURSEG_COLD_NODE;
1723 	}
1724 }
1725 
1726 static int __get_segment_type_6(struct page *page, enum page_type p_type)
1727 {
1728 	if (p_type == DATA) {
1729 		struct inode *inode = page->mapping->host;
1730 
1731 		if (S_ISDIR(inode->i_mode))
1732 			return CURSEG_HOT_DATA;
1733 		else if (is_cold_data(page) || file_is_cold(inode))
1734 			return CURSEG_COLD_DATA;
1735 		else
1736 			return CURSEG_WARM_DATA;
1737 	} else {
1738 		if (IS_DNODE(page))
1739 			return is_cold_node(page) ? CURSEG_WARM_NODE :
1740 						CURSEG_HOT_NODE;
1741 		else
1742 			return CURSEG_COLD_NODE;
1743 	}
1744 }
1745 
1746 static int __get_segment_type(struct page *page, enum page_type p_type)
1747 {
1748 	switch (F2FS_P_SB(page)->active_logs) {
1749 	case 2:
1750 		return __get_segment_type_2(page, p_type);
1751 	case 4:
1752 		return __get_segment_type_4(page, p_type);
1753 	}
1754 	/* NR_CURSEG_TYPE(6) logs by default */
1755 	f2fs_bug_on(F2FS_P_SB(page),
1756 		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
1757 	return __get_segment_type_6(page, p_type);
1758 }
1759 
1760 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
1761 		block_t old_blkaddr, block_t *new_blkaddr,
1762 		struct f2fs_summary *sum, int type)
1763 {
1764 	struct sit_info *sit_i = SIT_I(sbi);
1765 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1766 
1767 	mutex_lock(&curseg->curseg_mutex);
1768 	mutex_lock(&sit_i->sentry_lock);
1769 
1770 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
1771 
1772 	f2fs_wait_discard_bio(sbi, *new_blkaddr);
1773 
1774 	/*
1775 	 * __add_sum_entry should be resided under the curseg_mutex
1776 	 * because, this function updates a summary entry in the
1777 	 * current summary block.
1778 	 */
1779 	__add_sum_entry(sbi, type, sum);
1780 
1781 	__refresh_next_blkoff(sbi, curseg);
1782 
1783 	stat_inc_block_count(sbi, curseg);
1784 
1785 	/*
1786 	 * SIT information should be updated before segment allocation,
1787 	 * since SSR needs latest valid block information.
1788 	 */
1789 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
1790 
1791 	if (!__has_curseg_space(sbi, type))
1792 		sit_i->s_ops->allocate_segment(sbi, type, false);
1793 
1794 	mutex_unlock(&sit_i->sentry_lock);
1795 
1796 	if (page && IS_NODESEG(type))
1797 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
1798 
1799 	mutex_unlock(&curseg->curseg_mutex);
1800 }
1801 
1802 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
1803 {
1804 	int type = __get_segment_type(fio->page, fio->type);
1805 	int err;
1806 
1807 	if (fio->type == NODE || fio->type == DATA)
1808 		mutex_lock(&fio->sbi->wio_mutex[fio->type]);
1809 reallocate:
1810 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
1811 					&fio->new_blkaddr, sum, type);
1812 
1813 	/* writeout dirty page into bdev */
1814 	err = f2fs_submit_page_mbio(fio);
1815 	if (err == -EAGAIN) {
1816 		fio->old_blkaddr = fio->new_blkaddr;
1817 		goto reallocate;
1818 	}
1819 
1820 	if (fio->type == NODE || fio->type == DATA)
1821 		mutex_unlock(&fio->sbi->wio_mutex[fio->type]);
1822 }
1823 
1824 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
1825 {
1826 	struct f2fs_io_info fio = {
1827 		.sbi = sbi,
1828 		.type = META,
1829 		.op = REQ_OP_WRITE,
1830 		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
1831 		.old_blkaddr = page->index,
1832 		.new_blkaddr = page->index,
1833 		.page = page,
1834 		.encrypted_page = NULL,
1835 	};
1836 
1837 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
1838 		fio.op_flags &= ~REQ_META;
1839 
1840 	set_page_writeback(page);
1841 	f2fs_submit_page_mbio(&fio);
1842 }
1843 
1844 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
1845 {
1846 	struct f2fs_summary sum;
1847 
1848 	set_summary(&sum, nid, 0, 0);
1849 	do_write_page(&sum, fio);
1850 }
1851 
1852 void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
1853 {
1854 	struct f2fs_sb_info *sbi = fio->sbi;
1855 	struct f2fs_summary sum;
1856 	struct node_info ni;
1857 
1858 	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
1859 	get_node_info(sbi, dn->nid, &ni);
1860 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
1861 	do_write_page(&sum, fio);
1862 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
1863 }
1864 
1865 void rewrite_data_page(struct f2fs_io_info *fio)
1866 {
1867 	fio->new_blkaddr = fio->old_blkaddr;
1868 	stat_inc_inplace_blocks(fio->sbi);
1869 	f2fs_submit_page_mbio(fio);
1870 }
1871 
1872 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1873 				block_t old_blkaddr, block_t new_blkaddr,
1874 				bool recover_curseg, bool recover_newaddr)
1875 {
1876 	struct sit_info *sit_i = SIT_I(sbi);
1877 	struct curseg_info *curseg;
1878 	unsigned int segno, old_cursegno;
1879 	struct seg_entry *se;
1880 	int type;
1881 	unsigned short old_blkoff;
1882 
1883 	segno = GET_SEGNO(sbi, new_blkaddr);
1884 	se = get_seg_entry(sbi, segno);
1885 	type = se->type;
1886 
1887 	if (!recover_curseg) {
1888 		/* for recovery flow */
1889 		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
1890 			if (old_blkaddr == NULL_ADDR)
1891 				type = CURSEG_COLD_DATA;
1892 			else
1893 				type = CURSEG_WARM_DATA;
1894 		}
1895 	} else {
1896 		if (!IS_CURSEG(sbi, segno))
1897 			type = CURSEG_WARM_DATA;
1898 	}
1899 
1900 	curseg = CURSEG_I(sbi, type);
1901 
1902 	mutex_lock(&curseg->curseg_mutex);
1903 	mutex_lock(&sit_i->sentry_lock);
1904 
1905 	old_cursegno = curseg->segno;
1906 	old_blkoff = curseg->next_blkoff;
1907 
1908 	/* change the current segment */
1909 	if (segno != curseg->segno) {
1910 		curseg->next_segno = segno;
1911 		change_curseg(sbi, type, true);
1912 	}
1913 
1914 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
1915 	__add_sum_entry(sbi, type, sum);
1916 
1917 	if (!recover_curseg || recover_newaddr)
1918 		update_sit_entry(sbi, new_blkaddr, 1);
1919 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
1920 		update_sit_entry(sbi, old_blkaddr, -1);
1921 
1922 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
1923 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
1924 
1925 	locate_dirty_segment(sbi, old_cursegno);
1926 
1927 	if (recover_curseg) {
1928 		if (old_cursegno != curseg->segno) {
1929 			curseg->next_segno = old_cursegno;
1930 			change_curseg(sbi, type, true);
1931 		}
1932 		curseg->next_blkoff = old_blkoff;
1933 	}
1934 
1935 	mutex_unlock(&sit_i->sentry_lock);
1936 	mutex_unlock(&curseg->curseg_mutex);
1937 }
1938 
1939 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
1940 				block_t old_addr, block_t new_addr,
1941 				unsigned char version, bool recover_curseg,
1942 				bool recover_newaddr)
1943 {
1944 	struct f2fs_summary sum;
1945 
1946 	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
1947 
1948 	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
1949 					recover_curseg, recover_newaddr);
1950 
1951 	f2fs_update_data_blkaddr(dn, new_addr);
1952 }
1953 
1954 void f2fs_wait_on_page_writeback(struct page *page,
1955 				enum page_type type, bool ordered)
1956 {
1957 	if (PageWriteback(page)) {
1958 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1959 
1960 		f2fs_submit_merged_bio_cond(sbi, page->mapping->host,
1961 						0, page->index, type, WRITE);
1962 		if (ordered)
1963 			wait_on_page_writeback(page);
1964 		else
1965 			wait_for_stable_page(page);
1966 	}
1967 }
1968 
1969 void f2fs_wait_on_encrypted_page_writeback(struct f2fs_sb_info *sbi,
1970 							block_t blkaddr)
1971 {
1972 	struct page *cpage;
1973 
1974 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1975 		return;
1976 
1977 	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
1978 	if (cpage) {
1979 		f2fs_wait_on_page_writeback(cpage, DATA, true);
1980 		f2fs_put_page(cpage, 1);
1981 	}
1982 }
1983 
1984 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
1985 {
1986 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1987 	struct curseg_info *seg_i;
1988 	unsigned char *kaddr;
1989 	struct page *page;
1990 	block_t start;
1991 	int i, j, offset;
1992 
1993 	start = start_sum_block(sbi);
1994 
1995 	page = get_meta_page(sbi, start++);
1996 	kaddr = (unsigned char *)page_address(page);
1997 
1998 	/* Step 1: restore nat cache */
1999 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2000 	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
2001 
2002 	/* Step 2: restore sit cache */
2003 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2004 	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
2005 	offset = 2 * SUM_JOURNAL_SIZE;
2006 
2007 	/* Step 3: restore summary entries */
2008 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2009 		unsigned short blk_off;
2010 		unsigned int segno;
2011 
2012 		seg_i = CURSEG_I(sbi, i);
2013 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
2014 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
2015 		seg_i->next_segno = segno;
2016 		reset_curseg(sbi, i, 0);
2017 		seg_i->alloc_type = ckpt->alloc_type[i];
2018 		seg_i->next_blkoff = blk_off;
2019 
2020 		if (seg_i->alloc_type == SSR)
2021 			blk_off = sbi->blocks_per_seg;
2022 
2023 		for (j = 0; j < blk_off; j++) {
2024 			struct f2fs_summary *s;
2025 			s = (struct f2fs_summary *)(kaddr + offset);
2026 			seg_i->sum_blk->entries[j] = *s;
2027 			offset += SUMMARY_SIZE;
2028 			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
2029 						SUM_FOOTER_SIZE)
2030 				continue;
2031 
2032 			f2fs_put_page(page, 1);
2033 			page = NULL;
2034 
2035 			page = get_meta_page(sbi, start++);
2036 			kaddr = (unsigned char *)page_address(page);
2037 			offset = 0;
2038 		}
2039 	}
2040 	f2fs_put_page(page, 1);
2041 	return 0;
2042 }
2043 
2044 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
2045 {
2046 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2047 	struct f2fs_summary_block *sum;
2048 	struct curseg_info *curseg;
2049 	struct page *new;
2050 	unsigned short blk_off;
2051 	unsigned int segno = 0;
2052 	block_t blk_addr = 0;
2053 
2054 	/* get segment number and block addr */
2055 	if (IS_DATASEG(type)) {
2056 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
2057 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
2058 							CURSEG_HOT_DATA]);
2059 		if (__exist_node_summaries(sbi))
2060 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
2061 		else
2062 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
2063 	} else {
2064 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
2065 							CURSEG_HOT_NODE]);
2066 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
2067 							CURSEG_HOT_NODE]);
2068 		if (__exist_node_summaries(sbi))
2069 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
2070 							type - CURSEG_HOT_NODE);
2071 		else
2072 			blk_addr = GET_SUM_BLOCK(sbi, segno);
2073 	}
2074 
2075 	new = get_meta_page(sbi, blk_addr);
2076 	sum = (struct f2fs_summary_block *)page_address(new);
2077 
2078 	if (IS_NODESEG(type)) {
2079 		if (__exist_node_summaries(sbi)) {
2080 			struct f2fs_summary *ns = &sum->entries[0];
2081 			int i;
2082 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
2083 				ns->version = 0;
2084 				ns->ofs_in_node = 0;
2085 			}
2086 		} else {
2087 			int err;
2088 
2089 			err = restore_node_summary(sbi, segno, sum);
2090 			if (err) {
2091 				f2fs_put_page(new, 1);
2092 				return err;
2093 			}
2094 		}
2095 	}
2096 
2097 	/* set uncompleted segment to curseg */
2098 	curseg = CURSEG_I(sbi, type);
2099 	mutex_lock(&curseg->curseg_mutex);
2100 
2101 	/* update journal info */
2102 	down_write(&curseg->journal_rwsem);
2103 	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
2104 	up_write(&curseg->journal_rwsem);
2105 
2106 	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
2107 	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
2108 	curseg->next_segno = segno;
2109 	reset_curseg(sbi, type, 0);
2110 	curseg->alloc_type = ckpt->alloc_type[type];
2111 	curseg->next_blkoff = blk_off;
2112 	mutex_unlock(&curseg->curseg_mutex);
2113 	f2fs_put_page(new, 1);
2114 	return 0;
2115 }
2116 
2117 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
2118 {
2119 	int type = CURSEG_HOT_DATA;
2120 	int err;
2121 
2122 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
2123 		int npages = npages_for_summary_flush(sbi, true);
2124 
2125 		if (npages >= 2)
2126 			ra_meta_pages(sbi, start_sum_block(sbi), npages,
2127 							META_CP, true);
2128 
2129 		/* restore for compacted data summary */
2130 		if (read_compacted_summaries(sbi))
2131 			return -EINVAL;
2132 		type = CURSEG_HOT_NODE;
2133 	}
2134 
2135 	if (__exist_node_summaries(sbi))
2136 		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
2137 					NR_CURSEG_TYPE - type, META_CP, true);
2138 
2139 	for (; type <= CURSEG_COLD_NODE; type++) {
2140 		err = read_normal_summaries(sbi, type);
2141 		if (err)
2142 			return err;
2143 	}
2144 
2145 	return 0;
2146 }
2147 
2148 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
2149 {
2150 	struct page *page;
2151 	unsigned char *kaddr;
2152 	struct f2fs_summary *summary;
2153 	struct curseg_info *seg_i;
2154 	int written_size = 0;
2155 	int i, j;
2156 
2157 	page = grab_meta_page(sbi, blkaddr++);
2158 	kaddr = (unsigned char *)page_address(page);
2159 
2160 	/* Step 1: write nat cache */
2161 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2162 	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
2163 	written_size += SUM_JOURNAL_SIZE;
2164 
2165 	/* Step 2: write sit cache */
2166 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2167 	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
2168 	written_size += SUM_JOURNAL_SIZE;
2169 
2170 	/* Step 3: write summary entries */
2171 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2172 		unsigned short blkoff;
2173 		seg_i = CURSEG_I(sbi, i);
2174 		if (sbi->ckpt->alloc_type[i] == SSR)
2175 			blkoff = sbi->blocks_per_seg;
2176 		else
2177 			blkoff = curseg_blkoff(sbi, i);
2178 
2179 		for (j = 0; j < blkoff; j++) {
2180 			if (!page) {
2181 				page = grab_meta_page(sbi, blkaddr++);
2182 				kaddr = (unsigned char *)page_address(page);
2183 				written_size = 0;
2184 			}
2185 			summary = (struct f2fs_summary *)(kaddr + written_size);
2186 			*summary = seg_i->sum_blk->entries[j];
2187 			written_size += SUMMARY_SIZE;
2188 
2189 			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
2190 							SUM_FOOTER_SIZE)
2191 				continue;
2192 
2193 			set_page_dirty(page);
2194 			f2fs_put_page(page, 1);
2195 			page = NULL;
2196 		}
2197 	}
2198 	if (page) {
2199 		set_page_dirty(page);
2200 		f2fs_put_page(page, 1);
2201 	}
2202 }
2203 
2204 static void write_normal_summaries(struct f2fs_sb_info *sbi,
2205 					block_t blkaddr, int type)
2206 {
2207 	int i, end;
2208 	if (IS_DATASEG(type))
2209 		end = type + NR_CURSEG_DATA_TYPE;
2210 	else
2211 		end = type + NR_CURSEG_NODE_TYPE;
2212 
2213 	for (i = type; i < end; i++)
2214 		write_current_sum_page(sbi, i, blkaddr + (i - type));
2215 }
2216 
2217 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2218 {
2219 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
2220 		write_compacted_summaries(sbi, start_blk);
2221 	else
2222 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
2223 }
2224 
2225 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2226 {
2227 	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
2228 }
2229 
2230 int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
2231 					unsigned int val, int alloc)
2232 {
2233 	int i;
2234 
2235 	if (type == NAT_JOURNAL) {
2236 		for (i = 0; i < nats_in_cursum(journal); i++) {
2237 			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
2238 				return i;
2239 		}
2240 		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
2241 			return update_nats_in_cursum(journal, 1);
2242 	} else if (type == SIT_JOURNAL) {
2243 		for (i = 0; i < sits_in_cursum(journal); i++)
2244 			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
2245 				return i;
2246 		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
2247 			return update_sits_in_cursum(journal, 1);
2248 	}
2249 	return -1;
2250 }
2251 
2252 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
2253 					unsigned int segno)
2254 {
2255 	return get_meta_page(sbi, current_sit_addr(sbi, segno));
2256 }
2257 
2258 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
2259 					unsigned int start)
2260 {
2261 	struct sit_info *sit_i = SIT_I(sbi);
2262 	struct page *src_page, *dst_page;
2263 	pgoff_t src_off, dst_off;
2264 	void *src_addr, *dst_addr;
2265 
2266 	src_off = current_sit_addr(sbi, start);
2267 	dst_off = next_sit_addr(sbi, src_off);
2268 
2269 	/* get current sit block page without lock */
2270 	src_page = get_meta_page(sbi, src_off);
2271 	dst_page = grab_meta_page(sbi, dst_off);
2272 	f2fs_bug_on(sbi, PageDirty(src_page));
2273 
2274 	src_addr = page_address(src_page);
2275 	dst_addr = page_address(dst_page);
2276 	memcpy(dst_addr, src_addr, PAGE_SIZE);
2277 
2278 	set_page_dirty(dst_page);
2279 	f2fs_put_page(src_page, 1);
2280 
2281 	set_to_next_sit(sit_i, start);
2282 
2283 	return dst_page;
2284 }
2285 
2286 static struct sit_entry_set *grab_sit_entry_set(void)
2287 {
2288 	struct sit_entry_set *ses =
2289 			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
2290 
2291 	ses->entry_cnt = 0;
2292 	INIT_LIST_HEAD(&ses->set_list);
2293 	return ses;
2294 }
2295 
2296 static void release_sit_entry_set(struct sit_entry_set *ses)
2297 {
2298 	list_del(&ses->set_list);
2299 	kmem_cache_free(sit_entry_set_slab, ses);
2300 }
2301 
2302 static void adjust_sit_entry_set(struct sit_entry_set *ses,
2303 						struct list_head *head)
2304 {
2305 	struct sit_entry_set *next = ses;
2306 
2307 	if (list_is_last(&ses->set_list, head))
2308 		return;
2309 
2310 	list_for_each_entry_continue(next, head, set_list)
2311 		if (ses->entry_cnt <= next->entry_cnt)
2312 			break;
2313 
2314 	list_move_tail(&ses->set_list, &next->set_list);
2315 }
2316 
2317 static void add_sit_entry(unsigned int segno, struct list_head *head)
2318 {
2319 	struct sit_entry_set *ses;
2320 	unsigned int start_segno = START_SEGNO(segno);
2321 
2322 	list_for_each_entry(ses, head, set_list) {
2323 		if (ses->start_segno == start_segno) {
2324 			ses->entry_cnt++;
2325 			adjust_sit_entry_set(ses, head);
2326 			return;
2327 		}
2328 	}
2329 
2330 	ses = grab_sit_entry_set();
2331 
2332 	ses->start_segno = start_segno;
2333 	ses->entry_cnt++;
2334 	list_add(&ses->set_list, head);
2335 }
2336 
2337 static void add_sits_in_set(struct f2fs_sb_info *sbi)
2338 {
2339 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2340 	struct list_head *set_list = &sm_info->sit_entry_set;
2341 	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
2342 	unsigned int segno;
2343 
2344 	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
2345 		add_sit_entry(segno, set_list);
2346 }
2347 
2348 static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
2349 {
2350 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2351 	struct f2fs_journal *journal = curseg->journal;
2352 	int i;
2353 
2354 	down_write(&curseg->journal_rwsem);
2355 	for (i = 0; i < sits_in_cursum(journal); i++) {
2356 		unsigned int segno;
2357 		bool dirtied;
2358 
2359 		segno = le32_to_cpu(segno_in_journal(journal, i));
2360 		dirtied = __mark_sit_entry_dirty(sbi, segno);
2361 
2362 		if (!dirtied)
2363 			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
2364 	}
2365 	update_sits_in_cursum(journal, -i);
2366 	up_write(&curseg->journal_rwsem);
2367 }
2368 
2369 /*
2370  * CP calls this function, which flushes SIT entries including sit_journal,
2371  * and moves prefree segs to free segs.
2372  */
2373 void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
2374 {
2375 	struct sit_info *sit_i = SIT_I(sbi);
2376 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
2377 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2378 	struct f2fs_journal *journal = curseg->journal;
2379 	struct sit_entry_set *ses, *tmp;
2380 	struct list_head *head = &SM_I(sbi)->sit_entry_set;
2381 	bool to_journal = true;
2382 	struct seg_entry *se;
2383 
2384 	mutex_lock(&sit_i->sentry_lock);
2385 
2386 	if (!sit_i->dirty_sentries)
2387 		goto out;
2388 
2389 	/*
2390 	 * add and account sit entries of dirty bitmap in sit entry
2391 	 * set temporarily
2392 	 */
2393 	add_sits_in_set(sbi);
2394 
2395 	/*
2396 	 * if there are no enough space in journal to store dirty sit
2397 	 * entries, remove all entries from journal and add and account
2398 	 * them in sit entry set.
2399 	 */
2400 	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
2401 		remove_sits_in_journal(sbi);
2402 
2403 	/*
2404 	 * there are two steps to flush sit entries:
2405 	 * #1, flush sit entries to journal in current cold data summary block.
2406 	 * #2, flush sit entries to sit page.
2407 	 */
2408 	list_for_each_entry_safe(ses, tmp, head, set_list) {
2409 		struct page *page = NULL;
2410 		struct f2fs_sit_block *raw_sit = NULL;
2411 		unsigned int start_segno = ses->start_segno;
2412 		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
2413 						(unsigned long)MAIN_SEGS(sbi));
2414 		unsigned int segno = start_segno;
2415 
2416 		if (to_journal &&
2417 			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
2418 			to_journal = false;
2419 
2420 		if (to_journal) {
2421 			down_write(&curseg->journal_rwsem);
2422 		} else {
2423 			page = get_next_sit_page(sbi, start_segno);
2424 			raw_sit = page_address(page);
2425 		}
2426 
2427 		/* flush dirty sit entries in region of current sit set */
2428 		for_each_set_bit_from(segno, bitmap, end) {
2429 			int offset, sit_offset;
2430 
2431 			se = get_seg_entry(sbi, segno);
2432 
2433 			/* add discard candidates */
2434 			if (cpc->reason != CP_DISCARD) {
2435 				cpc->trim_start = segno;
2436 				add_discard_addrs(sbi, cpc, false);
2437 			}
2438 
2439 			if (to_journal) {
2440 				offset = lookup_journal_in_cursum(journal,
2441 							SIT_JOURNAL, segno, 1);
2442 				f2fs_bug_on(sbi, offset < 0);
2443 				segno_in_journal(journal, offset) =
2444 							cpu_to_le32(segno);
2445 				seg_info_to_raw_sit(se,
2446 					&sit_in_journal(journal, offset));
2447 			} else {
2448 				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
2449 				seg_info_to_raw_sit(se,
2450 						&raw_sit->entries[sit_offset]);
2451 			}
2452 
2453 			__clear_bit(segno, bitmap);
2454 			sit_i->dirty_sentries--;
2455 			ses->entry_cnt--;
2456 		}
2457 
2458 		if (to_journal)
2459 			up_write(&curseg->journal_rwsem);
2460 		else
2461 			f2fs_put_page(page, 1);
2462 
2463 		f2fs_bug_on(sbi, ses->entry_cnt);
2464 		release_sit_entry_set(ses);
2465 	}
2466 
2467 	f2fs_bug_on(sbi, !list_empty(head));
2468 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
2469 out:
2470 	if (cpc->reason == CP_DISCARD) {
2471 		__u64 trim_start = cpc->trim_start;
2472 
2473 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
2474 			add_discard_addrs(sbi, cpc, false);
2475 
2476 		cpc->trim_start = trim_start;
2477 	}
2478 	mutex_unlock(&sit_i->sentry_lock);
2479 
2480 	set_prefree_as_free_segments(sbi);
2481 }
2482 
2483 static int build_sit_info(struct f2fs_sb_info *sbi)
2484 {
2485 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2486 	struct sit_info *sit_i;
2487 	unsigned int sit_segs, start;
2488 	char *src_bitmap;
2489 	unsigned int bitmap_size;
2490 
2491 	/* allocate memory for SIT information */
2492 	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
2493 	if (!sit_i)
2494 		return -ENOMEM;
2495 
2496 	SM_I(sbi)->sit_info = sit_i;
2497 
2498 	sit_i->sentries = f2fs_kvzalloc(MAIN_SEGS(sbi) *
2499 					sizeof(struct seg_entry), GFP_KERNEL);
2500 	if (!sit_i->sentries)
2501 		return -ENOMEM;
2502 
2503 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2504 	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2505 	if (!sit_i->dirty_sentries_bitmap)
2506 		return -ENOMEM;
2507 
2508 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2509 		sit_i->sentries[start].cur_valid_map
2510 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2511 		sit_i->sentries[start].ckpt_valid_map
2512 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2513 		if (!sit_i->sentries[start].cur_valid_map ||
2514 				!sit_i->sentries[start].ckpt_valid_map)
2515 			return -ENOMEM;
2516 
2517 #ifdef CONFIG_F2FS_CHECK_FS
2518 		sit_i->sentries[start].cur_valid_map_mir
2519 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2520 		if (!sit_i->sentries[start].cur_valid_map_mir)
2521 			return -ENOMEM;
2522 #endif
2523 
2524 		if (f2fs_discard_en(sbi)) {
2525 			sit_i->sentries[start].discard_map
2526 				= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2527 			if (!sit_i->sentries[start].discard_map)
2528 				return -ENOMEM;
2529 		}
2530 	}
2531 
2532 	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2533 	if (!sit_i->tmp_map)
2534 		return -ENOMEM;
2535 
2536 	if (sbi->segs_per_sec > 1) {
2537 		sit_i->sec_entries = f2fs_kvzalloc(MAIN_SECS(sbi) *
2538 					sizeof(struct sec_entry), GFP_KERNEL);
2539 		if (!sit_i->sec_entries)
2540 			return -ENOMEM;
2541 	}
2542 
2543 	/* get information related with SIT */
2544 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
2545 
2546 	/* setup SIT bitmap from ckeckpoint pack */
2547 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
2548 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
2549 
2550 	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2551 	if (!sit_i->sit_bitmap)
2552 		return -ENOMEM;
2553 
2554 #ifdef CONFIG_F2FS_CHECK_FS
2555 	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2556 	if (!sit_i->sit_bitmap_mir)
2557 		return -ENOMEM;
2558 #endif
2559 
2560 	/* init SIT information */
2561 	sit_i->s_ops = &default_salloc_ops;
2562 
2563 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
2564 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
2565 	sit_i->written_valid_blocks = 0;
2566 	sit_i->bitmap_size = bitmap_size;
2567 	sit_i->dirty_sentries = 0;
2568 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
2569 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
2570 	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
2571 	mutex_init(&sit_i->sentry_lock);
2572 	return 0;
2573 }
2574 
2575 static int build_free_segmap(struct f2fs_sb_info *sbi)
2576 {
2577 	struct free_segmap_info *free_i;
2578 	unsigned int bitmap_size, sec_bitmap_size;
2579 
2580 	/* allocate memory for free segmap information */
2581 	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
2582 	if (!free_i)
2583 		return -ENOMEM;
2584 
2585 	SM_I(sbi)->free_info = free_i;
2586 
2587 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2588 	free_i->free_segmap = f2fs_kvmalloc(bitmap_size, GFP_KERNEL);
2589 	if (!free_i->free_segmap)
2590 		return -ENOMEM;
2591 
2592 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2593 	free_i->free_secmap = f2fs_kvmalloc(sec_bitmap_size, GFP_KERNEL);
2594 	if (!free_i->free_secmap)
2595 		return -ENOMEM;
2596 
2597 	/* set all segments as dirty temporarily */
2598 	memset(free_i->free_segmap, 0xff, bitmap_size);
2599 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
2600 
2601 	/* init free segmap information */
2602 	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
2603 	free_i->free_segments = 0;
2604 	free_i->free_sections = 0;
2605 	spin_lock_init(&free_i->segmap_lock);
2606 	return 0;
2607 }
2608 
2609 static int build_curseg(struct f2fs_sb_info *sbi)
2610 {
2611 	struct curseg_info *array;
2612 	int i;
2613 
2614 	array = kcalloc(NR_CURSEG_TYPE, sizeof(*array), GFP_KERNEL);
2615 	if (!array)
2616 		return -ENOMEM;
2617 
2618 	SM_I(sbi)->curseg_array = array;
2619 
2620 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2621 		mutex_init(&array[i].curseg_mutex);
2622 		array[i].sum_blk = kzalloc(PAGE_SIZE, GFP_KERNEL);
2623 		if (!array[i].sum_blk)
2624 			return -ENOMEM;
2625 		init_rwsem(&array[i].journal_rwsem);
2626 		array[i].journal = kzalloc(sizeof(struct f2fs_journal),
2627 							GFP_KERNEL);
2628 		if (!array[i].journal)
2629 			return -ENOMEM;
2630 		array[i].segno = NULL_SEGNO;
2631 		array[i].next_blkoff = 0;
2632 	}
2633 	return restore_curseg_summaries(sbi);
2634 }
2635 
2636 static void build_sit_entries(struct f2fs_sb_info *sbi)
2637 {
2638 	struct sit_info *sit_i = SIT_I(sbi);
2639 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2640 	struct f2fs_journal *journal = curseg->journal;
2641 	struct seg_entry *se;
2642 	struct f2fs_sit_entry sit;
2643 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
2644 	unsigned int i, start, end;
2645 	unsigned int readed, start_blk = 0;
2646 
2647 	do {
2648 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
2649 							META_SIT, true);
2650 
2651 		start = start_blk * sit_i->sents_per_block;
2652 		end = (start_blk + readed) * sit_i->sents_per_block;
2653 
2654 		for (; start < end && start < MAIN_SEGS(sbi); start++) {
2655 			struct f2fs_sit_block *sit_blk;
2656 			struct page *page;
2657 
2658 			se = &sit_i->sentries[start];
2659 			page = get_current_sit_page(sbi, start);
2660 			sit_blk = (struct f2fs_sit_block *)page_address(page);
2661 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
2662 			f2fs_put_page(page, 1);
2663 
2664 			check_block_count(sbi, start, &sit);
2665 			seg_info_from_raw_sit(se, &sit);
2666 
2667 			/* build discard map only one time */
2668 			if (f2fs_discard_en(sbi)) {
2669 				memcpy(se->discard_map, se->cur_valid_map,
2670 							SIT_VBLOCK_MAP_SIZE);
2671 				sbi->discard_blks += sbi->blocks_per_seg -
2672 							se->valid_blocks;
2673 			}
2674 
2675 			if (sbi->segs_per_sec > 1)
2676 				get_sec_entry(sbi, start)->valid_blocks +=
2677 							se->valid_blocks;
2678 		}
2679 		start_blk += readed;
2680 	} while (start_blk < sit_blk_cnt);
2681 
2682 	down_read(&curseg->journal_rwsem);
2683 	for (i = 0; i < sits_in_cursum(journal); i++) {
2684 		unsigned int old_valid_blocks;
2685 
2686 		start = le32_to_cpu(segno_in_journal(journal, i));
2687 		se = &sit_i->sentries[start];
2688 		sit = sit_in_journal(journal, i);
2689 
2690 		old_valid_blocks = se->valid_blocks;
2691 
2692 		check_block_count(sbi, start, &sit);
2693 		seg_info_from_raw_sit(se, &sit);
2694 
2695 		if (f2fs_discard_en(sbi)) {
2696 			memcpy(se->discard_map, se->cur_valid_map,
2697 						SIT_VBLOCK_MAP_SIZE);
2698 			sbi->discard_blks += old_valid_blocks -
2699 						se->valid_blocks;
2700 		}
2701 
2702 		if (sbi->segs_per_sec > 1)
2703 			get_sec_entry(sbi, start)->valid_blocks +=
2704 				se->valid_blocks - old_valid_blocks;
2705 	}
2706 	up_read(&curseg->journal_rwsem);
2707 }
2708 
2709 static void init_free_segmap(struct f2fs_sb_info *sbi)
2710 {
2711 	unsigned int start;
2712 	int type;
2713 
2714 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2715 		struct seg_entry *sentry = get_seg_entry(sbi, start);
2716 		if (!sentry->valid_blocks)
2717 			__set_free(sbi, start);
2718 		else
2719 			SIT_I(sbi)->written_valid_blocks +=
2720 						sentry->valid_blocks;
2721 	}
2722 
2723 	/* set use the current segments */
2724 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
2725 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
2726 		__set_test_and_inuse(sbi, curseg_t->segno);
2727 	}
2728 }
2729 
2730 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
2731 {
2732 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2733 	struct free_segmap_info *free_i = FREE_I(sbi);
2734 	unsigned int segno = 0, offset = 0;
2735 	unsigned short valid_blocks;
2736 
2737 	while (1) {
2738 		/* find dirty segment based on free segmap */
2739 		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
2740 		if (segno >= MAIN_SEGS(sbi))
2741 			break;
2742 		offset = segno + 1;
2743 		valid_blocks = get_valid_blocks(sbi, segno, 0);
2744 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
2745 			continue;
2746 		if (valid_blocks > sbi->blocks_per_seg) {
2747 			f2fs_bug_on(sbi, 1);
2748 			continue;
2749 		}
2750 		mutex_lock(&dirty_i->seglist_lock);
2751 		__locate_dirty_segment(sbi, segno, DIRTY);
2752 		mutex_unlock(&dirty_i->seglist_lock);
2753 	}
2754 }
2755 
2756 static int init_victim_secmap(struct f2fs_sb_info *sbi)
2757 {
2758 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2759 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2760 
2761 	dirty_i->victim_secmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2762 	if (!dirty_i->victim_secmap)
2763 		return -ENOMEM;
2764 	return 0;
2765 }
2766 
2767 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
2768 {
2769 	struct dirty_seglist_info *dirty_i;
2770 	unsigned int bitmap_size, i;
2771 
2772 	/* allocate memory for dirty segments list information */
2773 	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
2774 	if (!dirty_i)
2775 		return -ENOMEM;
2776 
2777 	SM_I(sbi)->dirty_info = dirty_i;
2778 	mutex_init(&dirty_i->seglist_lock);
2779 
2780 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2781 
2782 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
2783 		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2784 		if (!dirty_i->dirty_segmap[i])
2785 			return -ENOMEM;
2786 	}
2787 
2788 	init_dirty_segmap(sbi);
2789 	return init_victim_secmap(sbi);
2790 }
2791 
2792 /*
2793  * Update min, max modified time for cost-benefit GC algorithm
2794  */
2795 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
2796 {
2797 	struct sit_info *sit_i = SIT_I(sbi);
2798 	unsigned int segno;
2799 
2800 	mutex_lock(&sit_i->sentry_lock);
2801 
2802 	sit_i->min_mtime = LLONG_MAX;
2803 
2804 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
2805 		unsigned int i;
2806 		unsigned long long mtime = 0;
2807 
2808 		for (i = 0; i < sbi->segs_per_sec; i++)
2809 			mtime += get_seg_entry(sbi, segno + i)->mtime;
2810 
2811 		mtime = div_u64(mtime, sbi->segs_per_sec);
2812 
2813 		if (sit_i->min_mtime > mtime)
2814 			sit_i->min_mtime = mtime;
2815 	}
2816 	sit_i->max_mtime = get_mtime(sbi);
2817 	mutex_unlock(&sit_i->sentry_lock);
2818 }
2819 
2820 int build_segment_manager(struct f2fs_sb_info *sbi)
2821 {
2822 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2823 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2824 	struct f2fs_sm_info *sm_info;
2825 	int err;
2826 
2827 	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
2828 	if (!sm_info)
2829 		return -ENOMEM;
2830 
2831 	/* init sm info */
2832 	sbi->sm_info = sm_info;
2833 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
2834 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
2835 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
2836 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
2837 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
2838 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
2839 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
2840 	sm_info->rec_prefree_segments = sm_info->main_segments *
2841 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
2842 	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
2843 		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
2844 
2845 	if (!test_opt(sbi, LFS))
2846 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
2847 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
2848 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
2849 
2850 	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
2851 
2852 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
2853 
2854 	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
2855 		err = create_flush_cmd_control(sbi);
2856 		if (err)
2857 			return err;
2858 	}
2859 
2860 	err = create_discard_cmd_control(sbi);
2861 	if (err)
2862 		return err;
2863 
2864 	err = build_sit_info(sbi);
2865 	if (err)
2866 		return err;
2867 	err = build_free_segmap(sbi);
2868 	if (err)
2869 		return err;
2870 	err = build_curseg(sbi);
2871 	if (err)
2872 		return err;
2873 
2874 	/* reinit free segmap based on SIT */
2875 	build_sit_entries(sbi);
2876 
2877 	init_free_segmap(sbi);
2878 	err = build_dirty_segmap(sbi);
2879 	if (err)
2880 		return err;
2881 
2882 	init_min_max_mtime(sbi);
2883 	return 0;
2884 }
2885 
2886 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
2887 		enum dirty_type dirty_type)
2888 {
2889 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2890 
2891 	mutex_lock(&dirty_i->seglist_lock);
2892 	kvfree(dirty_i->dirty_segmap[dirty_type]);
2893 	dirty_i->nr_dirty[dirty_type] = 0;
2894 	mutex_unlock(&dirty_i->seglist_lock);
2895 }
2896 
2897 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
2898 {
2899 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2900 	kvfree(dirty_i->victim_secmap);
2901 }
2902 
2903 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
2904 {
2905 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2906 	int i;
2907 
2908 	if (!dirty_i)
2909 		return;
2910 
2911 	/* discard pre-free/dirty segments list */
2912 	for (i = 0; i < NR_DIRTY_TYPE; i++)
2913 		discard_dirty_segmap(sbi, i);
2914 
2915 	destroy_victim_secmap(sbi);
2916 	SM_I(sbi)->dirty_info = NULL;
2917 	kfree(dirty_i);
2918 }
2919 
2920 static void destroy_curseg(struct f2fs_sb_info *sbi)
2921 {
2922 	struct curseg_info *array = SM_I(sbi)->curseg_array;
2923 	int i;
2924 
2925 	if (!array)
2926 		return;
2927 	SM_I(sbi)->curseg_array = NULL;
2928 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2929 		kfree(array[i].sum_blk);
2930 		kfree(array[i].journal);
2931 	}
2932 	kfree(array);
2933 }
2934 
2935 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
2936 {
2937 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
2938 	if (!free_i)
2939 		return;
2940 	SM_I(sbi)->free_info = NULL;
2941 	kvfree(free_i->free_segmap);
2942 	kvfree(free_i->free_secmap);
2943 	kfree(free_i);
2944 }
2945 
2946 static void destroy_sit_info(struct f2fs_sb_info *sbi)
2947 {
2948 	struct sit_info *sit_i = SIT_I(sbi);
2949 	unsigned int start;
2950 
2951 	if (!sit_i)
2952 		return;
2953 
2954 	if (sit_i->sentries) {
2955 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
2956 			kfree(sit_i->sentries[start].cur_valid_map);
2957 #ifdef CONFIG_F2FS_CHECK_FS
2958 			kfree(sit_i->sentries[start].cur_valid_map_mir);
2959 #endif
2960 			kfree(sit_i->sentries[start].ckpt_valid_map);
2961 			kfree(sit_i->sentries[start].discard_map);
2962 		}
2963 	}
2964 	kfree(sit_i->tmp_map);
2965 
2966 	kvfree(sit_i->sentries);
2967 	kvfree(sit_i->sec_entries);
2968 	kvfree(sit_i->dirty_sentries_bitmap);
2969 
2970 	SM_I(sbi)->sit_info = NULL;
2971 	kfree(sit_i->sit_bitmap);
2972 #ifdef CONFIG_F2FS_CHECK_FS
2973 	kfree(sit_i->sit_bitmap_mir);
2974 #endif
2975 	kfree(sit_i);
2976 }
2977 
2978 void destroy_segment_manager(struct f2fs_sb_info *sbi)
2979 {
2980 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2981 
2982 	if (!sm_info)
2983 		return;
2984 	destroy_flush_cmd_control(sbi, true);
2985 	destroy_discard_cmd_control(sbi, true);
2986 	destroy_dirty_segmap(sbi);
2987 	destroy_curseg(sbi);
2988 	destroy_free_segmap(sbi);
2989 	destroy_sit_info(sbi);
2990 	sbi->sm_info = NULL;
2991 	kfree(sm_info);
2992 }
2993 
2994 int __init create_segment_manager_caches(void)
2995 {
2996 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
2997 			sizeof(struct discard_entry));
2998 	if (!discard_entry_slab)
2999 		goto fail;
3000 
3001 	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
3002 			sizeof(struct discard_cmd));
3003 	if (!discard_cmd_slab)
3004 		goto destroy_discard_entry;
3005 
3006 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
3007 			sizeof(struct sit_entry_set));
3008 	if (!sit_entry_set_slab)
3009 		goto destroy_discard_cmd;
3010 
3011 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
3012 			sizeof(struct inmem_pages));
3013 	if (!inmem_entry_slab)
3014 		goto destroy_sit_entry_set;
3015 	return 0;
3016 
3017 destroy_sit_entry_set:
3018 	kmem_cache_destroy(sit_entry_set_slab);
3019 destroy_discard_cmd:
3020 	kmem_cache_destroy(discard_cmd_slab);
3021 destroy_discard_entry:
3022 	kmem_cache_destroy(discard_entry_slab);
3023 fail:
3024 	return -ENOMEM;
3025 }
3026 
3027 void destroy_segment_manager_caches(void)
3028 {
3029 	kmem_cache_destroy(sit_entry_set_slab);
3030 	kmem_cache_destroy(discard_cmd_slab);
3031 	kmem_cache_destroy(discard_entry_slab);
3032 	kmem_cache_destroy(inmem_entry_slab);
3033 }
3034