xref: /openbmc/linux/fs/f2fs/segment.c (revision 22ad0b6ab46683975c6da032f1c2593066c7b3bd)
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_stop_checkpoint(sbi, false);
357 #endif
358 
359 	if (!need)
360 		return;
361 
362 	/* balance_fs_bg is able to be pending */
363 	if (excess_cached_nats(sbi))
364 		f2fs_balance_fs_bg(sbi);
365 
366 	/*
367 	 * We should do GC or end up with checkpoint, if there are so many dirty
368 	 * dir/node pages without enough free segments.
369 	 */
370 	if (has_not_enough_free_secs(sbi, 0, 0)) {
371 		mutex_lock(&sbi->gc_mutex);
372 		f2fs_gc(sbi, false, false);
373 	}
374 }
375 
376 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
377 {
378 	/* try to shrink extent cache when there is no enough memory */
379 	if (!available_free_memory(sbi, EXTENT_CACHE))
380 		f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
381 
382 	/* check the # of cached NAT entries */
383 	if (!available_free_memory(sbi, NAT_ENTRIES))
384 		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
385 
386 	if (!available_free_memory(sbi, FREE_NIDS))
387 		try_to_free_nids(sbi, MAX_FREE_NIDS);
388 	else
389 		build_free_nids(sbi, false, false);
390 
391 	if (!is_idle(sbi))
392 		return;
393 
394 	/* checkpoint is the only way to shrink partial cached entries */
395 	if (!available_free_memory(sbi, NAT_ENTRIES) ||
396 			!available_free_memory(sbi, INO_ENTRIES) ||
397 			excess_prefree_segs(sbi) ||
398 			excess_dirty_nats(sbi) ||
399 			f2fs_time_over(sbi, CP_TIME)) {
400 		if (test_opt(sbi, DATA_FLUSH)) {
401 			struct blk_plug plug;
402 
403 			blk_start_plug(&plug);
404 			sync_dirty_inodes(sbi, FILE_INODE);
405 			blk_finish_plug(&plug);
406 		}
407 		f2fs_sync_fs(sbi->sb, true);
408 		stat_inc_bg_cp_count(sbi->stat_info);
409 	}
410 }
411 
412 static int __submit_flush_wait(struct block_device *bdev)
413 {
414 	struct bio *bio = f2fs_bio_alloc(0);
415 	int ret;
416 
417 	bio->bi_opf = REQ_OP_WRITE | REQ_PREFLUSH;
418 	bio->bi_bdev = bdev;
419 	ret = submit_bio_wait(bio);
420 	bio_put(bio);
421 	return ret;
422 }
423 
424 static int submit_flush_wait(struct f2fs_sb_info *sbi)
425 {
426 	int ret = __submit_flush_wait(sbi->sb->s_bdev);
427 	int i;
428 
429 	if (sbi->s_ndevs && !ret) {
430 		for (i = 1; i < sbi->s_ndevs; i++) {
431 			trace_f2fs_issue_flush(FDEV(i).bdev,
432 					test_opt(sbi, NOBARRIER),
433 					test_opt(sbi, FLUSH_MERGE));
434 			ret = __submit_flush_wait(FDEV(i).bdev);
435 			if (ret)
436 				break;
437 		}
438 	}
439 	return ret;
440 }
441 
442 static int issue_flush_thread(void *data)
443 {
444 	struct f2fs_sb_info *sbi = data;
445 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
446 	wait_queue_head_t *q = &fcc->flush_wait_queue;
447 repeat:
448 	if (kthread_should_stop())
449 		return 0;
450 
451 	if (!llist_empty(&fcc->issue_list)) {
452 		struct flush_cmd *cmd, *next;
453 		int ret;
454 
455 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
456 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
457 
458 		ret = submit_flush_wait(sbi);
459 		llist_for_each_entry_safe(cmd, next,
460 					  fcc->dispatch_list, llnode) {
461 			cmd->ret = ret;
462 			complete(&cmd->wait);
463 		}
464 		fcc->dispatch_list = NULL;
465 	}
466 
467 	wait_event_interruptible(*q,
468 		kthread_should_stop() || !llist_empty(&fcc->issue_list));
469 	goto repeat;
470 }
471 
472 int f2fs_issue_flush(struct f2fs_sb_info *sbi)
473 {
474 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
475 	struct flush_cmd cmd;
476 
477 	if (test_opt(sbi, NOBARRIER))
478 		return 0;
479 
480 	if (!test_opt(sbi, FLUSH_MERGE))
481 		return submit_flush_wait(sbi);
482 
483 	if (!atomic_read(&fcc->submit_flush)) {
484 		int ret;
485 
486 		atomic_inc(&fcc->submit_flush);
487 		ret = submit_flush_wait(sbi);
488 		atomic_dec(&fcc->submit_flush);
489 		return ret;
490 	}
491 
492 	init_completion(&cmd.wait);
493 
494 	atomic_inc(&fcc->submit_flush);
495 	llist_add(&cmd.llnode, &fcc->issue_list);
496 
497 	if (!fcc->dispatch_list)
498 		wake_up(&fcc->flush_wait_queue);
499 
500 	if (fcc->f2fs_issue_flush) {
501 		wait_for_completion(&cmd.wait);
502 		atomic_dec(&fcc->submit_flush);
503 	} else {
504 		llist_del_all(&fcc->issue_list);
505 		atomic_set(&fcc->submit_flush, 0);
506 	}
507 
508 	return cmd.ret;
509 }
510 
511 int create_flush_cmd_control(struct f2fs_sb_info *sbi)
512 {
513 	dev_t dev = sbi->sb->s_bdev->bd_dev;
514 	struct flush_cmd_control *fcc;
515 	int err = 0;
516 
517 	if (SM_I(sbi)->fcc_info) {
518 		fcc = SM_I(sbi)->fcc_info;
519 		goto init_thread;
520 	}
521 
522 	fcc = kzalloc(sizeof(struct flush_cmd_control), GFP_KERNEL);
523 	if (!fcc)
524 		return -ENOMEM;
525 	atomic_set(&fcc->submit_flush, 0);
526 	init_waitqueue_head(&fcc->flush_wait_queue);
527 	init_llist_head(&fcc->issue_list);
528 	SM_I(sbi)->fcc_info = fcc;
529 init_thread:
530 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
531 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
532 	if (IS_ERR(fcc->f2fs_issue_flush)) {
533 		err = PTR_ERR(fcc->f2fs_issue_flush);
534 		kfree(fcc);
535 		SM_I(sbi)->fcc_info = NULL;
536 		return err;
537 	}
538 
539 	return err;
540 }
541 
542 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
543 {
544 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
545 
546 	if (fcc && fcc->f2fs_issue_flush) {
547 		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
548 
549 		fcc->f2fs_issue_flush = NULL;
550 		kthread_stop(flush_thread);
551 	}
552 	if (free) {
553 		kfree(fcc);
554 		SM_I(sbi)->fcc_info = NULL;
555 	}
556 }
557 
558 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
559 		enum dirty_type dirty_type)
560 {
561 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
562 
563 	/* need not be added */
564 	if (IS_CURSEG(sbi, segno))
565 		return;
566 
567 	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
568 		dirty_i->nr_dirty[dirty_type]++;
569 
570 	if (dirty_type == DIRTY) {
571 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
572 		enum dirty_type t = sentry->type;
573 
574 		if (unlikely(t >= DIRTY)) {
575 			f2fs_bug_on(sbi, 1);
576 			return;
577 		}
578 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
579 			dirty_i->nr_dirty[t]++;
580 	}
581 }
582 
583 static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
584 		enum dirty_type dirty_type)
585 {
586 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
587 
588 	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
589 		dirty_i->nr_dirty[dirty_type]--;
590 
591 	if (dirty_type == DIRTY) {
592 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
593 		enum dirty_type t = sentry->type;
594 
595 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
596 			dirty_i->nr_dirty[t]--;
597 
598 		if (get_valid_blocks(sbi, segno, sbi->segs_per_sec) == 0)
599 			clear_bit(GET_SECNO(sbi, segno),
600 						dirty_i->victim_secmap);
601 	}
602 }
603 
604 /*
605  * Should not occur error such as -ENOMEM.
606  * Adding dirty entry into seglist is not critical operation.
607  * If a given segment is one of current working segments, it won't be added.
608  */
609 static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
610 {
611 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
612 	unsigned short valid_blocks;
613 
614 	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
615 		return;
616 
617 	mutex_lock(&dirty_i->seglist_lock);
618 
619 	valid_blocks = get_valid_blocks(sbi, segno, 0);
620 
621 	if (valid_blocks == 0) {
622 		__locate_dirty_segment(sbi, segno, PRE);
623 		__remove_dirty_segment(sbi, segno, DIRTY);
624 	} else if (valid_blocks < sbi->blocks_per_seg) {
625 		__locate_dirty_segment(sbi, segno, DIRTY);
626 	} else {
627 		/* Recovery routine with SSR needs this */
628 		__remove_dirty_segment(sbi, segno, DIRTY);
629 	}
630 
631 	mutex_unlock(&dirty_i->seglist_lock);
632 }
633 
634 static void __add_discard_cmd(struct f2fs_sb_info *sbi,
635 			struct bio *bio, block_t lstart, block_t len)
636 {
637 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
638 	struct list_head *cmd_list = &(dcc->discard_cmd_list);
639 	struct discard_cmd *dc;
640 
641 	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
642 	INIT_LIST_HEAD(&dc->list);
643 	dc->bio = bio;
644 	bio->bi_private = dc;
645 	dc->lstart = lstart;
646 	dc->len = len;
647 	dc->state = D_PREP;
648 	init_completion(&dc->wait);
649 
650 	mutex_lock(&dcc->cmd_lock);
651 	list_add_tail(&dc->list, cmd_list);
652 	mutex_unlock(&dcc->cmd_lock);
653 }
654 
655 static void __remove_discard_cmd(struct f2fs_sb_info *sbi, struct discard_cmd *dc)
656 {
657 	int err = dc->bio->bi_error;
658 
659 	if (dc->state == D_DONE)
660 		atomic_dec(&(SM_I(sbi)->dcc_info->submit_discard));
661 
662 	if (err == -EOPNOTSUPP)
663 		err = 0;
664 
665 	if (err)
666 		f2fs_msg(sbi->sb, KERN_INFO,
667 				"Issue discard failed, ret: %d", err);
668 	bio_put(dc->bio);
669 	list_del(&dc->list);
670 	kmem_cache_free(discard_cmd_slab, dc);
671 }
672 
673 /* This should be covered by global mutex, &sit_i->sentry_lock */
674 void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
675 {
676 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
677 	struct list_head *wait_list = &(dcc->discard_cmd_list);
678 	struct discard_cmd *dc, *tmp;
679 	struct blk_plug plug;
680 
681 	mutex_lock(&dcc->cmd_lock);
682 
683 	blk_start_plug(&plug);
684 
685 	list_for_each_entry_safe(dc, tmp, wait_list, list) {
686 
687 		if (blkaddr == NULL_ADDR) {
688 			if (dc->state == D_PREP) {
689 				dc->state = D_SUBMIT;
690 				submit_bio(dc->bio);
691 				atomic_inc(&dcc->submit_discard);
692 			}
693 			continue;
694 		}
695 
696 		if (dc->lstart <= blkaddr && blkaddr < dc->lstart + dc->len) {
697 			if (dc->state == D_SUBMIT)
698 				wait_for_completion_io(&dc->wait);
699 			else
700 				__remove_discard_cmd(sbi, dc);
701 		}
702 	}
703 	blk_finish_plug(&plug);
704 
705 	/* this comes from f2fs_put_super */
706 	if (blkaddr == NULL_ADDR) {
707 		list_for_each_entry_safe(dc, tmp, wait_list, list) {
708 			wait_for_completion_io(&dc->wait);
709 			__remove_discard_cmd(sbi, dc);
710 		}
711 	}
712 	mutex_unlock(&dcc->cmd_lock);
713 }
714 
715 static void f2fs_submit_discard_endio(struct bio *bio)
716 {
717 	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
718 
719 	complete(&dc->wait);
720 	dc->state = D_DONE;
721 }
722 
723 static int issue_discard_thread(void *data)
724 {
725 	struct f2fs_sb_info *sbi = data;
726 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
727 	wait_queue_head_t *q = &dcc->discard_wait_queue;
728 	struct list_head *cmd_list = &dcc->discard_cmd_list;
729 	struct discard_cmd *dc, *tmp;
730 	struct blk_plug plug;
731 	int iter = 0;
732 repeat:
733 	if (kthread_should_stop())
734 		return 0;
735 
736 	blk_start_plug(&plug);
737 
738 	mutex_lock(&dcc->cmd_lock);
739 	list_for_each_entry_safe(dc, tmp, cmd_list, list) {
740 		if (dc->state == D_PREP) {
741 			dc->state = D_SUBMIT;
742 			submit_bio(dc->bio);
743 			atomic_inc(&dcc->submit_discard);
744 			if (iter++ > DISCARD_ISSUE_RATE)
745 				break;
746 		} else if (dc->state == D_DONE) {
747 			__remove_discard_cmd(sbi, dc);
748 		}
749 	}
750 	mutex_unlock(&dcc->cmd_lock);
751 
752 	blk_finish_plug(&plug);
753 
754 	iter = 0;
755 	congestion_wait(BLK_RW_SYNC, HZ/50);
756 
757 	wait_event_interruptible(*q,
758 		kthread_should_stop() || !list_empty(&dcc->discard_cmd_list));
759 	goto repeat;
760 }
761 
762 
763 /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
764 static int __f2fs_issue_discard_async(struct f2fs_sb_info *sbi,
765 		struct block_device *bdev, block_t blkstart, block_t blklen)
766 {
767 	struct bio *bio = NULL;
768 	block_t lblkstart = blkstart;
769 	int err;
770 
771 	trace_f2fs_issue_discard(bdev, blkstart, blklen);
772 
773 	if (sbi->s_ndevs) {
774 		int devi = f2fs_target_device_index(sbi, blkstart);
775 
776 		blkstart -= FDEV(devi).start_blk;
777 	}
778 	err = __blkdev_issue_discard(bdev,
779 				SECTOR_FROM_BLOCK(blkstart),
780 				SECTOR_FROM_BLOCK(blklen),
781 				GFP_NOFS, 0, &bio);
782 	if (!err && bio) {
783 		bio->bi_end_io = f2fs_submit_discard_endio;
784 		bio->bi_opf |= REQ_SYNC;
785 
786 		__add_discard_cmd(sbi, bio, lblkstart, blklen);
787 		wake_up(&SM_I(sbi)->dcc_info->discard_wait_queue);
788 	}
789 	return err;
790 }
791 
792 #ifdef CONFIG_BLK_DEV_ZONED
793 static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
794 		struct block_device *bdev, block_t blkstart, block_t blklen)
795 {
796 	sector_t sector, nr_sects;
797 	int devi = 0;
798 
799 	if (sbi->s_ndevs) {
800 		devi = f2fs_target_device_index(sbi, blkstart);
801 		blkstart -= FDEV(devi).start_blk;
802 	}
803 
804 	/*
805 	 * We need to know the type of the zone: for conventional zones,
806 	 * use regular discard if the drive supports it. For sequential
807 	 * zones, reset the zone write pointer.
808 	 */
809 	switch (get_blkz_type(sbi, bdev, blkstart)) {
810 
811 	case BLK_ZONE_TYPE_CONVENTIONAL:
812 		if (!blk_queue_discard(bdev_get_queue(bdev)))
813 			return 0;
814 		return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
815 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
816 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
817 		sector = SECTOR_FROM_BLOCK(blkstart);
818 		nr_sects = SECTOR_FROM_BLOCK(blklen);
819 
820 		if (sector & (bdev_zone_sectors(bdev) - 1) ||
821 				nr_sects != bdev_zone_sectors(bdev)) {
822 			f2fs_msg(sbi->sb, KERN_INFO,
823 				"(%d) %s: Unaligned discard attempted (block %x + %x)",
824 				devi, sbi->s_ndevs ? FDEV(devi).path: "",
825 				blkstart, blklen);
826 			return -EIO;
827 		}
828 		trace_f2fs_issue_reset_zone(bdev, blkstart);
829 		return blkdev_reset_zones(bdev, sector,
830 					  nr_sects, GFP_NOFS);
831 	default:
832 		/* Unknown zone type: broken device ? */
833 		return -EIO;
834 	}
835 }
836 #endif
837 
838 static int __issue_discard_async(struct f2fs_sb_info *sbi,
839 		struct block_device *bdev, block_t blkstart, block_t blklen)
840 {
841 #ifdef CONFIG_BLK_DEV_ZONED
842 	if (f2fs_sb_mounted_blkzoned(sbi->sb) &&
843 				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
844 		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
845 #endif
846 	return __f2fs_issue_discard_async(sbi, bdev, blkstart, blklen);
847 }
848 
849 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
850 				block_t blkstart, block_t blklen)
851 {
852 	sector_t start = blkstart, len = 0;
853 	struct block_device *bdev;
854 	struct seg_entry *se;
855 	unsigned int offset;
856 	block_t i;
857 	int err = 0;
858 
859 	bdev = f2fs_target_device(sbi, blkstart, NULL);
860 
861 	for (i = blkstart; i < blkstart + blklen; i++, len++) {
862 		if (i != start) {
863 			struct block_device *bdev2 =
864 				f2fs_target_device(sbi, i, NULL);
865 
866 			if (bdev2 != bdev) {
867 				err = __issue_discard_async(sbi, bdev,
868 						start, len);
869 				if (err)
870 					return err;
871 				bdev = bdev2;
872 				start = i;
873 				len = 0;
874 			}
875 		}
876 
877 		se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
878 		offset = GET_BLKOFF_FROM_SEG0(sbi, i);
879 
880 		if (!f2fs_test_and_set_bit(offset, se->discard_map))
881 			sbi->discard_blks--;
882 	}
883 
884 	if (len)
885 		err = __issue_discard_async(sbi, bdev, start, len);
886 	return err;
887 }
888 
889 static void __add_discard_entry(struct f2fs_sb_info *sbi,
890 		struct cp_control *cpc, struct seg_entry *se,
891 		unsigned int start, unsigned int end)
892 {
893 	struct list_head *head = &SM_I(sbi)->dcc_info->discard_entry_list;
894 	struct discard_entry *new, *last;
895 
896 	if (!list_empty(head)) {
897 		last = list_last_entry(head, struct discard_entry, list);
898 		if (START_BLOCK(sbi, cpc->trim_start) + start ==
899 				last->blkaddr + last->len &&
900 				last->len < MAX_DISCARD_BLOCKS(sbi)) {
901 			last->len += end - start;
902 			goto done;
903 		}
904 	}
905 
906 	new = f2fs_kmem_cache_alloc(discard_entry_slab, GFP_NOFS);
907 	INIT_LIST_HEAD(&new->list);
908 	new->blkaddr = START_BLOCK(sbi, cpc->trim_start) + start;
909 	new->len = end - start;
910 	list_add_tail(&new->list, head);
911 done:
912 	SM_I(sbi)->dcc_info->nr_discards += end - start;
913 }
914 
915 static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
916 							bool check_only)
917 {
918 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
919 	int max_blocks = sbi->blocks_per_seg;
920 	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
921 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
922 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
923 	unsigned long *discard_map = (unsigned long *)se->discard_map;
924 	unsigned long *dmap = SIT_I(sbi)->tmp_map;
925 	unsigned int start = 0, end = -1;
926 	bool force = (cpc->reason == CP_DISCARD);
927 	int i;
928 
929 	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
930 		return false;
931 
932 	if (!force) {
933 		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
934 			SM_I(sbi)->dcc_info->nr_discards >=
935 				SM_I(sbi)->dcc_info->max_discards)
936 			return false;
937 	}
938 
939 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
940 	for (i = 0; i < entries; i++)
941 		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
942 				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
943 
944 	while (force || SM_I(sbi)->dcc_info->nr_discards <=
945 				SM_I(sbi)->dcc_info->max_discards) {
946 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
947 		if (start >= max_blocks)
948 			break;
949 
950 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
951 		if (force && start && end != max_blocks
952 					&& (end - start) < cpc->trim_minlen)
953 			continue;
954 
955 		if (check_only)
956 			return true;
957 
958 		__add_discard_entry(sbi, cpc, se, start, end);
959 	}
960 	return false;
961 }
962 
963 void release_discard_addrs(struct f2fs_sb_info *sbi)
964 {
965 	struct list_head *head = &(SM_I(sbi)->dcc_info->discard_entry_list);
966 	struct discard_entry *entry, *this;
967 
968 	/* drop caches */
969 	list_for_each_entry_safe(entry, this, head, list) {
970 		list_del(&entry->list);
971 		kmem_cache_free(discard_entry_slab, entry);
972 	}
973 }
974 
975 /*
976  * Should call clear_prefree_segments after checkpoint is done.
977  */
978 static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
979 {
980 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
981 	unsigned int segno;
982 
983 	mutex_lock(&dirty_i->seglist_lock);
984 	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
985 		__set_test_and_free(sbi, segno);
986 	mutex_unlock(&dirty_i->seglist_lock);
987 }
988 
989 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
990 {
991 	struct list_head *head = &(SM_I(sbi)->dcc_info->discard_entry_list);
992 	struct discard_entry *entry, *this;
993 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
994 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
995 	unsigned int start = 0, end = -1;
996 	unsigned int secno, start_segno;
997 	bool force = (cpc->reason == CP_DISCARD);
998 
999 	mutex_lock(&dirty_i->seglist_lock);
1000 
1001 	while (1) {
1002 		int i;
1003 		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
1004 		if (start >= MAIN_SEGS(sbi))
1005 			break;
1006 		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
1007 								start + 1);
1008 
1009 		for (i = start; i < end; i++)
1010 			clear_bit(i, prefree_map);
1011 
1012 		dirty_i->nr_dirty[PRE] -= end - start;
1013 
1014 		if (!test_opt(sbi, DISCARD))
1015 			continue;
1016 
1017 		if (force && start >= cpc->trim_start &&
1018 					(end - 1) <= cpc->trim_end)
1019 				continue;
1020 
1021 		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
1022 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
1023 				(end - start) << sbi->log_blocks_per_seg);
1024 			continue;
1025 		}
1026 next:
1027 		secno = GET_SECNO(sbi, start);
1028 		start_segno = secno * sbi->segs_per_sec;
1029 		if (!IS_CURSEC(sbi, secno) &&
1030 			!get_valid_blocks(sbi, start, sbi->segs_per_sec))
1031 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
1032 				sbi->segs_per_sec << sbi->log_blocks_per_seg);
1033 
1034 		start = start_segno + sbi->segs_per_sec;
1035 		if (start < end)
1036 			goto next;
1037 	}
1038 	mutex_unlock(&dirty_i->seglist_lock);
1039 
1040 	/* send small discards */
1041 	list_for_each_entry_safe(entry, this, head, list) {
1042 		if (force && entry->len < cpc->trim_minlen)
1043 			goto skip;
1044 		f2fs_issue_discard(sbi, entry->blkaddr, entry->len);
1045 		cpc->trimmed += entry->len;
1046 skip:
1047 		list_del(&entry->list);
1048 		SM_I(sbi)->dcc_info->nr_discards -= entry->len;
1049 		kmem_cache_free(discard_entry_slab, entry);
1050 	}
1051 }
1052 
1053 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
1054 {
1055 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1056 	struct discard_cmd_control *dcc;
1057 	int err = 0;
1058 
1059 	if (SM_I(sbi)->dcc_info) {
1060 		dcc = SM_I(sbi)->dcc_info;
1061 		goto init_thread;
1062 	}
1063 
1064 	dcc = kzalloc(sizeof(struct discard_cmd_control), GFP_KERNEL);
1065 	if (!dcc)
1066 		return -ENOMEM;
1067 
1068 	INIT_LIST_HEAD(&dcc->discard_entry_list);
1069 	INIT_LIST_HEAD(&dcc->discard_cmd_list);
1070 	mutex_init(&dcc->cmd_lock);
1071 	atomic_set(&dcc->submit_discard, 0);
1072 	dcc->nr_discards = 0;
1073 	dcc->max_discards = 0;
1074 
1075 	init_waitqueue_head(&dcc->discard_wait_queue);
1076 	SM_I(sbi)->dcc_info = dcc;
1077 init_thread:
1078 	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
1079 				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
1080 	if (IS_ERR(dcc->f2fs_issue_discard)) {
1081 		err = PTR_ERR(dcc->f2fs_issue_discard);
1082 		kfree(dcc);
1083 		SM_I(sbi)->dcc_info = NULL;
1084 		return err;
1085 	}
1086 
1087 	return err;
1088 }
1089 
1090 static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi, bool free)
1091 {
1092 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1093 
1094 	if (dcc && dcc->f2fs_issue_discard) {
1095 		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
1096 
1097 		dcc->f2fs_issue_discard = NULL;
1098 		kthread_stop(discard_thread);
1099 	}
1100 	if (free) {
1101 		kfree(dcc);
1102 		SM_I(sbi)->dcc_info = NULL;
1103 	}
1104 }
1105 
1106 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
1107 {
1108 	struct sit_info *sit_i = SIT_I(sbi);
1109 
1110 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
1111 		sit_i->dirty_sentries++;
1112 		return false;
1113 	}
1114 
1115 	return true;
1116 }
1117 
1118 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
1119 					unsigned int segno, int modified)
1120 {
1121 	struct seg_entry *se = get_seg_entry(sbi, segno);
1122 	se->type = type;
1123 	if (modified)
1124 		__mark_sit_entry_dirty(sbi, segno);
1125 }
1126 
1127 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
1128 {
1129 	struct seg_entry *se;
1130 	unsigned int segno, offset;
1131 	long int new_vblocks;
1132 
1133 	segno = GET_SEGNO(sbi, blkaddr);
1134 
1135 	se = get_seg_entry(sbi, segno);
1136 	new_vblocks = se->valid_blocks + del;
1137 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1138 
1139 	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
1140 				(new_vblocks > sbi->blocks_per_seg)));
1141 
1142 	se->valid_blocks = new_vblocks;
1143 	se->mtime = get_mtime(sbi);
1144 	SIT_I(sbi)->max_mtime = se->mtime;
1145 
1146 	/* Update valid block bitmap */
1147 	if (del > 0) {
1148 		if (f2fs_test_and_set_bit(offset, se->cur_valid_map)) {
1149 #ifdef CONFIG_F2FS_CHECK_FS
1150 			if (f2fs_test_and_set_bit(offset,
1151 						se->cur_valid_map_mir))
1152 				f2fs_bug_on(sbi, 1);
1153 			else
1154 				WARN_ON(1);
1155 #else
1156 			f2fs_bug_on(sbi, 1);
1157 #endif
1158 		}
1159 		if (f2fs_discard_en(sbi) &&
1160 			!f2fs_test_and_set_bit(offset, se->discard_map))
1161 			sbi->discard_blks--;
1162 	} else {
1163 		if (!f2fs_test_and_clear_bit(offset, se->cur_valid_map)) {
1164 #ifdef CONFIG_F2FS_CHECK_FS
1165 			if (!f2fs_test_and_clear_bit(offset,
1166 						se->cur_valid_map_mir))
1167 				f2fs_bug_on(sbi, 1);
1168 			else
1169 				WARN_ON(1);
1170 #else
1171 			f2fs_bug_on(sbi, 1);
1172 #endif
1173 		}
1174 		if (f2fs_discard_en(sbi) &&
1175 			f2fs_test_and_clear_bit(offset, se->discard_map))
1176 			sbi->discard_blks++;
1177 	}
1178 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
1179 		se->ckpt_valid_blocks += del;
1180 
1181 	__mark_sit_entry_dirty(sbi, segno);
1182 
1183 	/* update total number of valid blocks to be written in ckpt area */
1184 	SIT_I(sbi)->written_valid_blocks += del;
1185 
1186 	if (sbi->segs_per_sec > 1)
1187 		get_sec_entry(sbi, segno)->valid_blocks += del;
1188 }
1189 
1190 void refresh_sit_entry(struct f2fs_sb_info *sbi, block_t old, block_t new)
1191 {
1192 	update_sit_entry(sbi, new, 1);
1193 	if (GET_SEGNO(sbi, old) != NULL_SEGNO)
1194 		update_sit_entry(sbi, old, -1);
1195 
1196 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old));
1197 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new));
1198 }
1199 
1200 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
1201 {
1202 	unsigned int segno = GET_SEGNO(sbi, addr);
1203 	struct sit_info *sit_i = SIT_I(sbi);
1204 
1205 	f2fs_bug_on(sbi, addr == NULL_ADDR);
1206 	if (addr == NEW_ADDR)
1207 		return;
1208 
1209 	/* add it into sit main buffer */
1210 	mutex_lock(&sit_i->sentry_lock);
1211 
1212 	update_sit_entry(sbi, addr, -1);
1213 
1214 	/* add it into dirty seglist */
1215 	locate_dirty_segment(sbi, segno);
1216 
1217 	mutex_unlock(&sit_i->sentry_lock);
1218 }
1219 
1220 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
1221 {
1222 	struct sit_info *sit_i = SIT_I(sbi);
1223 	unsigned int segno, offset;
1224 	struct seg_entry *se;
1225 	bool is_cp = false;
1226 
1227 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1228 		return true;
1229 
1230 	mutex_lock(&sit_i->sentry_lock);
1231 
1232 	segno = GET_SEGNO(sbi, blkaddr);
1233 	se = get_seg_entry(sbi, segno);
1234 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1235 
1236 	if (f2fs_test_bit(offset, se->ckpt_valid_map))
1237 		is_cp = true;
1238 
1239 	mutex_unlock(&sit_i->sentry_lock);
1240 
1241 	return is_cp;
1242 }
1243 
1244 /*
1245  * This function should be resided under the curseg_mutex lock
1246  */
1247 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
1248 					struct f2fs_summary *sum)
1249 {
1250 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1251 	void *addr = curseg->sum_blk;
1252 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
1253 	memcpy(addr, sum, sizeof(struct f2fs_summary));
1254 }
1255 
1256 /*
1257  * Calculate the number of current summary pages for writing
1258  */
1259 int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
1260 {
1261 	int valid_sum_count = 0;
1262 	int i, sum_in_page;
1263 
1264 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1265 		if (sbi->ckpt->alloc_type[i] == SSR)
1266 			valid_sum_count += sbi->blocks_per_seg;
1267 		else {
1268 			if (for_ra)
1269 				valid_sum_count += le16_to_cpu(
1270 					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
1271 			else
1272 				valid_sum_count += curseg_blkoff(sbi, i);
1273 		}
1274 	}
1275 
1276 	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
1277 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
1278 	if (valid_sum_count <= sum_in_page)
1279 		return 1;
1280 	else if ((valid_sum_count - sum_in_page) <=
1281 		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
1282 		return 2;
1283 	return 3;
1284 }
1285 
1286 /*
1287  * Caller should put this summary page
1288  */
1289 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
1290 {
1291 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
1292 }
1293 
1294 void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
1295 {
1296 	struct page *page = grab_meta_page(sbi, blk_addr);
1297 	void *dst = page_address(page);
1298 
1299 	if (src)
1300 		memcpy(dst, src, PAGE_SIZE);
1301 	else
1302 		memset(dst, 0, PAGE_SIZE);
1303 	set_page_dirty(page);
1304 	f2fs_put_page(page, 1);
1305 }
1306 
1307 static void write_sum_page(struct f2fs_sb_info *sbi,
1308 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
1309 {
1310 	update_meta_page(sbi, (void *)sum_blk, blk_addr);
1311 }
1312 
1313 static void write_current_sum_page(struct f2fs_sb_info *sbi,
1314 						int type, block_t blk_addr)
1315 {
1316 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1317 	struct page *page = grab_meta_page(sbi, blk_addr);
1318 	struct f2fs_summary_block *src = curseg->sum_blk;
1319 	struct f2fs_summary_block *dst;
1320 
1321 	dst = (struct f2fs_summary_block *)page_address(page);
1322 
1323 	mutex_lock(&curseg->curseg_mutex);
1324 
1325 	down_read(&curseg->journal_rwsem);
1326 	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
1327 	up_read(&curseg->journal_rwsem);
1328 
1329 	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
1330 	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
1331 
1332 	mutex_unlock(&curseg->curseg_mutex);
1333 
1334 	set_page_dirty(page);
1335 	f2fs_put_page(page, 1);
1336 }
1337 
1338 /*
1339  * Find a new segment from the free segments bitmap to right order
1340  * This function should be returned with success, otherwise BUG
1341  */
1342 static void get_new_segment(struct f2fs_sb_info *sbi,
1343 			unsigned int *newseg, bool new_sec, int dir)
1344 {
1345 	struct free_segmap_info *free_i = FREE_I(sbi);
1346 	unsigned int segno, secno, zoneno;
1347 	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
1348 	unsigned int hint = *newseg / sbi->segs_per_sec;
1349 	unsigned int old_zoneno = GET_ZONENO_FROM_SEGNO(sbi, *newseg);
1350 	unsigned int left_start = hint;
1351 	bool init = true;
1352 	int go_left = 0;
1353 	int i;
1354 
1355 	spin_lock(&free_i->segmap_lock);
1356 
1357 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
1358 		segno = find_next_zero_bit(free_i->free_segmap,
1359 				(hint + 1) * sbi->segs_per_sec, *newseg + 1);
1360 		if (segno < (hint + 1) * sbi->segs_per_sec)
1361 			goto got_it;
1362 	}
1363 find_other_zone:
1364 	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
1365 	if (secno >= MAIN_SECS(sbi)) {
1366 		if (dir == ALLOC_RIGHT) {
1367 			secno = find_next_zero_bit(free_i->free_secmap,
1368 							MAIN_SECS(sbi), 0);
1369 			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
1370 		} else {
1371 			go_left = 1;
1372 			left_start = hint - 1;
1373 		}
1374 	}
1375 	if (go_left == 0)
1376 		goto skip_left;
1377 
1378 	while (test_bit(left_start, free_i->free_secmap)) {
1379 		if (left_start > 0) {
1380 			left_start--;
1381 			continue;
1382 		}
1383 		left_start = find_next_zero_bit(free_i->free_secmap,
1384 							MAIN_SECS(sbi), 0);
1385 		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
1386 		break;
1387 	}
1388 	secno = left_start;
1389 skip_left:
1390 	hint = secno;
1391 	segno = secno * sbi->segs_per_sec;
1392 	zoneno = secno / sbi->secs_per_zone;
1393 
1394 	/* give up on finding another zone */
1395 	if (!init)
1396 		goto got_it;
1397 	if (sbi->secs_per_zone == 1)
1398 		goto got_it;
1399 	if (zoneno == old_zoneno)
1400 		goto got_it;
1401 	if (dir == ALLOC_LEFT) {
1402 		if (!go_left && zoneno + 1 >= total_zones)
1403 			goto got_it;
1404 		if (go_left && zoneno == 0)
1405 			goto got_it;
1406 	}
1407 	for (i = 0; i < NR_CURSEG_TYPE; i++)
1408 		if (CURSEG_I(sbi, i)->zone == zoneno)
1409 			break;
1410 
1411 	if (i < NR_CURSEG_TYPE) {
1412 		/* zone is in user, try another */
1413 		if (go_left)
1414 			hint = zoneno * sbi->secs_per_zone - 1;
1415 		else if (zoneno + 1 >= total_zones)
1416 			hint = 0;
1417 		else
1418 			hint = (zoneno + 1) * sbi->secs_per_zone;
1419 		init = false;
1420 		goto find_other_zone;
1421 	}
1422 got_it:
1423 	/* set it as dirty segment in free segmap */
1424 	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
1425 	__set_inuse(sbi, segno);
1426 	*newseg = segno;
1427 	spin_unlock(&free_i->segmap_lock);
1428 }
1429 
1430 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
1431 {
1432 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1433 	struct summary_footer *sum_footer;
1434 
1435 	curseg->segno = curseg->next_segno;
1436 	curseg->zone = GET_ZONENO_FROM_SEGNO(sbi, curseg->segno);
1437 	curseg->next_blkoff = 0;
1438 	curseg->next_segno = NULL_SEGNO;
1439 
1440 	sum_footer = &(curseg->sum_blk->footer);
1441 	memset(sum_footer, 0, sizeof(struct summary_footer));
1442 	if (IS_DATASEG(type))
1443 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
1444 	if (IS_NODESEG(type))
1445 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
1446 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
1447 }
1448 
1449 /*
1450  * Allocate a current working segment.
1451  * This function always allocates a free segment in LFS manner.
1452  */
1453 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
1454 {
1455 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1456 	unsigned int segno = curseg->segno;
1457 	int dir = ALLOC_LEFT;
1458 
1459 	write_sum_page(sbi, curseg->sum_blk,
1460 				GET_SUM_BLOCK(sbi, segno));
1461 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
1462 		dir = ALLOC_RIGHT;
1463 
1464 	if (test_opt(sbi, NOHEAP))
1465 		dir = ALLOC_RIGHT;
1466 
1467 	get_new_segment(sbi, &segno, new_sec, dir);
1468 	curseg->next_segno = segno;
1469 	reset_curseg(sbi, type, 1);
1470 	curseg->alloc_type = LFS;
1471 }
1472 
1473 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
1474 			struct curseg_info *seg, block_t start)
1475 {
1476 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
1477 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1478 	unsigned long *target_map = SIT_I(sbi)->tmp_map;
1479 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1480 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1481 	int i, pos;
1482 
1483 	for (i = 0; i < entries; i++)
1484 		target_map[i] = ckpt_map[i] | cur_map[i];
1485 
1486 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
1487 
1488 	seg->next_blkoff = pos;
1489 }
1490 
1491 /*
1492  * If a segment is written by LFS manner, next block offset is just obtained
1493  * by increasing the current block offset. However, if a segment is written by
1494  * SSR manner, next block offset obtained by calling __next_free_blkoff
1495  */
1496 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
1497 				struct curseg_info *seg)
1498 {
1499 	if (seg->alloc_type == SSR)
1500 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
1501 	else
1502 		seg->next_blkoff++;
1503 }
1504 
1505 /*
1506  * This function always allocates a used segment(from dirty seglist) by SSR
1507  * manner, so it should recover the existing segment information of valid blocks
1508  */
1509 static void change_curseg(struct f2fs_sb_info *sbi, int type, bool reuse)
1510 {
1511 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1512 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1513 	unsigned int new_segno = curseg->next_segno;
1514 	struct f2fs_summary_block *sum_node;
1515 	struct page *sum_page;
1516 
1517 	write_sum_page(sbi, curseg->sum_blk,
1518 				GET_SUM_BLOCK(sbi, curseg->segno));
1519 	__set_test_and_inuse(sbi, new_segno);
1520 
1521 	mutex_lock(&dirty_i->seglist_lock);
1522 	__remove_dirty_segment(sbi, new_segno, PRE);
1523 	__remove_dirty_segment(sbi, new_segno, DIRTY);
1524 	mutex_unlock(&dirty_i->seglist_lock);
1525 
1526 	reset_curseg(sbi, type, 1);
1527 	curseg->alloc_type = SSR;
1528 	__next_free_blkoff(sbi, curseg, 0);
1529 
1530 	if (reuse) {
1531 		sum_page = get_sum_page(sbi, new_segno);
1532 		sum_node = (struct f2fs_summary_block *)page_address(sum_page);
1533 		memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
1534 		f2fs_put_page(sum_page, 1);
1535 	}
1536 }
1537 
1538 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
1539 {
1540 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1541 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
1542 	int i, n;
1543 
1544 	/* need_SSR() already forces to do this */
1545 	if (v_ops->get_victim(sbi, &(curseg)->next_segno, BG_GC, type, SSR))
1546 		return 1;
1547 
1548 	/* For node segments, let's do SSR more intensively */
1549 	if (IS_NODESEG(type)) {
1550 		i = CURSEG_HOT_NODE;
1551 		n = CURSEG_COLD_NODE;
1552 	} else {
1553 		i = CURSEG_HOT_DATA;
1554 		n = CURSEG_COLD_DATA;
1555 	}
1556 
1557 	for (; i <= n; i++) {
1558 		if (i == type)
1559 			continue;
1560 		if (v_ops->get_victim(sbi, &(curseg)->next_segno,
1561 						BG_GC, i, SSR))
1562 			return 1;
1563 	}
1564 	return 0;
1565 }
1566 
1567 /*
1568  * flush out current segment and replace it with new segment
1569  * This function should be returned with success, otherwise BUG
1570  */
1571 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
1572 						int type, bool force)
1573 {
1574 	if (force)
1575 		new_curseg(sbi, type, true);
1576 	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
1577 					type == CURSEG_WARM_NODE)
1578 		new_curseg(sbi, type, false);
1579 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
1580 		change_curseg(sbi, type, true);
1581 	else
1582 		new_curseg(sbi, type, false);
1583 
1584 	stat_inc_seg_type(sbi, CURSEG_I(sbi, type));
1585 }
1586 
1587 void allocate_new_segments(struct f2fs_sb_info *sbi)
1588 {
1589 	struct curseg_info *curseg;
1590 	unsigned int old_segno;
1591 	int i;
1592 
1593 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1594 		curseg = CURSEG_I(sbi, i);
1595 		old_segno = curseg->segno;
1596 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
1597 		locate_dirty_segment(sbi, old_segno);
1598 	}
1599 }
1600 
1601 static const struct segment_allocation default_salloc_ops = {
1602 	.allocate_segment = allocate_segment_by_default,
1603 };
1604 
1605 bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1606 {
1607 	__u64 trim_start = cpc->trim_start;
1608 	bool has_candidate = false;
1609 
1610 	mutex_lock(&SIT_I(sbi)->sentry_lock);
1611 	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
1612 		if (add_discard_addrs(sbi, cpc, true)) {
1613 			has_candidate = true;
1614 			break;
1615 		}
1616 	}
1617 	mutex_unlock(&SIT_I(sbi)->sentry_lock);
1618 
1619 	cpc->trim_start = trim_start;
1620 	return has_candidate;
1621 }
1622 
1623 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
1624 {
1625 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
1626 	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
1627 	unsigned int start_segno, end_segno;
1628 	struct cp_control cpc;
1629 	int err = 0;
1630 
1631 	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
1632 		return -EINVAL;
1633 
1634 	cpc.trimmed = 0;
1635 	if (end <= MAIN_BLKADDR(sbi))
1636 		goto out;
1637 
1638 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1639 		f2fs_msg(sbi->sb, KERN_WARNING,
1640 			"Found FS corruption, run fsck to fix.");
1641 		goto out;
1642 	}
1643 
1644 	/* start/end segment number in main_area */
1645 	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
1646 	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
1647 						GET_SEGNO(sbi, end);
1648 	cpc.reason = CP_DISCARD;
1649 	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
1650 
1651 	/* do checkpoint to issue discard commands safely */
1652 	for (; start_segno <= end_segno; start_segno = cpc.trim_end + 1) {
1653 		cpc.trim_start = start_segno;
1654 
1655 		if (sbi->discard_blks == 0)
1656 			break;
1657 		else if (sbi->discard_blks < BATCHED_TRIM_BLOCKS(sbi))
1658 			cpc.trim_end = end_segno;
1659 		else
1660 			cpc.trim_end = min_t(unsigned int,
1661 				rounddown(start_segno +
1662 				BATCHED_TRIM_SEGMENTS(sbi),
1663 				sbi->segs_per_sec) - 1, end_segno);
1664 
1665 		mutex_lock(&sbi->gc_mutex);
1666 		err = write_checkpoint(sbi, &cpc);
1667 		mutex_unlock(&sbi->gc_mutex);
1668 		if (err)
1669 			break;
1670 
1671 		schedule();
1672 	}
1673 out:
1674 	range->len = F2FS_BLK_TO_BYTES(cpc.trimmed);
1675 	return err;
1676 }
1677 
1678 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
1679 {
1680 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1681 	if (curseg->next_blkoff < sbi->blocks_per_seg)
1682 		return true;
1683 	return false;
1684 }
1685 
1686 static int __get_segment_type_2(struct page *page, enum page_type p_type)
1687 {
1688 	if (p_type == DATA)
1689 		return CURSEG_HOT_DATA;
1690 	else
1691 		return CURSEG_HOT_NODE;
1692 }
1693 
1694 static int __get_segment_type_4(struct page *page, enum page_type p_type)
1695 {
1696 	if (p_type == DATA) {
1697 		struct inode *inode = page->mapping->host;
1698 
1699 		if (S_ISDIR(inode->i_mode))
1700 			return CURSEG_HOT_DATA;
1701 		else
1702 			return CURSEG_COLD_DATA;
1703 	} else {
1704 		if (IS_DNODE(page) && is_cold_node(page))
1705 			return CURSEG_WARM_NODE;
1706 		else
1707 			return CURSEG_COLD_NODE;
1708 	}
1709 }
1710 
1711 static int __get_segment_type_6(struct page *page, enum page_type p_type)
1712 {
1713 	if (p_type == DATA) {
1714 		struct inode *inode = page->mapping->host;
1715 
1716 		if (S_ISDIR(inode->i_mode))
1717 			return CURSEG_HOT_DATA;
1718 		else if (is_cold_data(page) || file_is_cold(inode))
1719 			return CURSEG_COLD_DATA;
1720 		else
1721 			return CURSEG_WARM_DATA;
1722 	} else {
1723 		if (IS_DNODE(page))
1724 			return is_cold_node(page) ? CURSEG_WARM_NODE :
1725 						CURSEG_HOT_NODE;
1726 		else
1727 			return CURSEG_COLD_NODE;
1728 	}
1729 }
1730 
1731 static int __get_segment_type(struct page *page, enum page_type p_type)
1732 {
1733 	switch (F2FS_P_SB(page)->active_logs) {
1734 	case 2:
1735 		return __get_segment_type_2(page, p_type);
1736 	case 4:
1737 		return __get_segment_type_4(page, p_type);
1738 	}
1739 	/* NR_CURSEG_TYPE(6) logs by default */
1740 	f2fs_bug_on(F2FS_P_SB(page),
1741 		F2FS_P_SB(page)->active_logs != NR_CURSEG_TYPE);
1742 	return __get_segment_type_6(page, p_type);
1743 }
1744 
1745 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
1746 		block_t old_blkaddr, block_t *new_blkaddr,
1747 		struct f2fs_summary *sum, int type)
1748 {
1749 	struct sit_info *sit_i = SIT_I(sbi);
1750 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1751 
1752 	mutex_lock(&curseg->curseg_mutex);
1753 	mutex_lock(&sit_i->sentry_lock);
1754 
1755 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
1756 
1757 	f2fs_wait_discard_bio(sbi, *new_blkaddr);
1758 
1759 	/*
1760 	 * __add_sum_entry should be resided under the curseg_mutex
1761 	 * because, this function updates a summary entry in the
1762 	 * current summary block.
1763 	 */
1764 	__add_sum_entry(sbi, type, sum);
1765 
1766 	__refresh_next_blkoff(sbi, curseg);
1767 
1768 	stat_inc_block_count(sbi, curseg);
1769 
1770 	/*
1771 	 * SIT information should be updated before segment allocation,
1772 	 * since SSR needs latest valid block information.
1773 	 */
1774 	refresh_sit_entry(sbi, old_blkaddr, *new_blkaddr);
1775 
1776 	if (!__has_curseg_space(sbi, type))
1777 		sit_i->s_ops->allocate_segment(sbi, type, false);
1778 
1779 	mutex_unlock(&sit_i->sentry_lock);
1780 
1781 	if (page && IS_NODESEG(type))
1782 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
1783 
1784 	mutex_unlock(&curseg->curseg_mutex);
1785 }
1786 
1787 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
1788 {
1789 	int type = __get_segment_type(fio->page, fio->type);
1790 	int err;
1791 
1792 	if (fio->type == NODE || fio->type == DATA)
1793 		mutex_lock(&fio->sbi->wio_mutex[fio->type]);
1794 reallocate:
1795 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
1796 					&fio->new_blkaddr, sum, type);
1797 
1798 	/* writeout dirty page into bdev */
1799 	err = f2fs_submit_page_mbio(fio);
1800 	if (err == -EAGAIN) {
1801 		fio->old_blkaddr = fio->new_blkaddr;
1802 		goto reallocate;
1803 	}
1804 
1805 	if (fio->type == NODE || fio->type == DATA)
1806 		mutex_unlock(&fio->sbi->wio_mutex[fio->type]);
1807 }
1808 
1809 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page)
1810 {
1811 	struct f2fs_io_info fio = {
1812 		.sbi = sbi,
1813 		.type = META,
1814 		.op = REQ_OP_WRITE,
1815 		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
1816 		.old_blkaddr = page->index,
1817 		.new_blkaddr = page->index,
1818 		.page = page,
1819 		.encrypted_page = NULL,
1820 	};
1821 
1822 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
1823 		fio.op_flags &= ~REQ_META;
1824 
1825 	set_page_writeback(page);
1826 	f2fs_submit_page_mbio(&fio);
1827 }
1828 
1829 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
1830 {
1831 	struct f2fs_summary sum;
1832 
1833 	set_summary(&sum, nid, 0, 0);
1834 	do_write_page(&sum, fio);
1835 }
1836 
1837 void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
1838 {
1839 	struct f2fs_sb_info *sbi = fio->sbi;
1840 	struct f2fs_summary sum;
1841 	struct node_info ni;
1842 
1843 	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
1844 	get_node_info(sbi, dn->nid, &ni);
1845 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
1846 	do_write_page(&sum, fio);
1847 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
1848 }
1849 
1850 void rewrite_data_page(struct f2fs_io_info *fio)
1851 {
1852 	fio->new_blkaddr = fio->old_blkaddr;
1853 	stat_inc_inplace_blocks(fio->sbi);
1854 	f2fs_submit_page_mbio(fio);
1855 }
1856 
1857 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
1858 				block_t old_blkaddr, block_t new_blkaddr,
1859 				bool recover_curseg, bool recover_newaddr)
1860 {
1861 	struct sit_info *sit_i = SIT_I(sbi);
1862 	struct curseg_info *curseg;
1863 	unsigned int segno, old_cursegno;
1864 	struct seg_entry *se;
1865 	int type;
1866 	unsigned short old_blkoff;
1867 
1868 	segno = GET_SEGNO(sbi, new_blkaddr);
1869 	se = get_seg_entry(sbi, segno);
1870 	type = se->type;
1871 
1872 	if (!recover_curseg) {
1873 		/* for recovery flow */
1874 		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
1875 			if (old_blkaddr == NULL_ADDR)
1876 				type = CURSEG_COLD_DATA;
1877 			else
1878 				type = CURSEG_WARM_DATA;
1879 		}
1880 	} else {
1881 		if (!IS_CURSEG(sbi, segno))
1882 			type = CURSEG_WARM_DATA;
1883 	}
1884 
1885 	curseg = CURSEG_I(sbi, type);
1886 
1887 	mutex_lock(&curseg->curseg_mutex);
1888 	mutex_lock(&sit_i->sentry_lock);
1889 
1890 	old_cursegno = curseg->segno;
1891 	old_blkoff = curseg->next_blkoff;
1892 
1893 	/* change the current segment */
1894 	if (segno != curseg->segno) {
1895 		curseg->next_segno = segno;
1896 		change_curseg(sbi, type, true);
1897 	}
1898 
1899 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
1900 	__add_sum_entry(sbi, type, sum);
1901 
1902 	if (!recover_curseg || recover_newaddr)
1903 		update_sit_entry(sbi, new_blkaddr, 1);
1904 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
1905 		update_sit_entry(sbi, old_blkaddr, -1);
1906 
1907 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
1908 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
1909 
1910 	locate_dirty_segment(sbi, old_cursegno);
1911 
1912 	if (recover_curseg) {
1913 		if (old_cursegno != curseg->segno) {
1914 			curseg->next_segno = old_cursegno;
1915 			change_curseg(sbi, type, true);
1916 		}
1917 		curseg->next_blkoff = old_blkoff;
1918 	}
1919 
1920 	mutex_unlock(&sit_i->sentry_lock);
1921 	mutex_unlock(&curseg->curseg_mutex);
1922 }
1923 
1924 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
1925 				block_t old_addr, block_t new_addr,
1926 				unsigned char version, bool recover_curseg,
1927 				bool recover_newaddr)
1928 {
1929 	struct f2fs_summary sum;
1930 
1931 	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
1932 
1933 	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
1934 					recover_curseg, recover_newaddr);
1935 
1936 	f2fs_update_data_blkaddr(dn, new_addr);
1937 }
1938 
1939 void f2fs_wait_on_page_writeback(struct page *page,
1940 				enum page_type type, bool ordered)
1941 {
1942 	if (PageWriteback(page)) {
1943 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1944 
1945 		f2fs_submit_merged_bio_cond(sbi, page->mapping->host,
1946 						0, page->index, type, WRITE);
1947 		if (ordered)
1948 			wait_on_page_writeback(page);
1949 		else
1950 			wait_for_stable_page(page);
1951 	}
1952 }
1953 
1954 void f2fs_wait_on_encrypted_page_writeback(struct f2fs_sb_info *sbi,
1955 							block_t blkaddr)
1956 {
1957 	struct page *cpage;
1958 
1959 	if (blkaddr == NEW_ADDR || blkaddr == NULL_ADDR)
1960 		return;
1961 
1962 	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
1963 	if (cpage) {
1964 		f2fs_wait_on_page_writeback(cpage, DATA, true);
1965 		f2fs_put_page(cpage, 1);
1966 	}
1967 }
1968 
1969 static int read_compacted_summaries(struct f2fs_sb_info *sbi)
1970 {
1971 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
1972 	struct curseg_info *seg_i;
1973 	unsigned char *kaddr;
1974 	struct page *page;
1975 	block_t start;
1976 	int i, j, offset;
1977 
1978 	start = start_sum_block(sbi);
1979 
1980 	page = get_meta_page(sbi, start++);
1981 	kaddr = (unsigned char *)page_address(page);
1982 
1983 	/* Step 1: restore nat cache */
1984 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
1985 	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
1986 
1987 	/* Step 2: restore sit cache */
1988 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
1989 	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
1990 	offset = 2 * SUM_JOURNAL_SIZE;
1991 
1992 	/* Step 3: restore summary entries */
1993 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1994 		unsigned short blk_off;
1995 		unsigned int segno;
1996 
1997 		seg_i = CURSEG_I(sbi, i);
1998 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
1999 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
2000 		seg_i->next_segno = segno;
2001 		reset_curseg(sbi, i, 0);
2002 		seg_i->alloc_type = ckpt->alloc_type[i];
2003 		seg_i->next_blkoff = blk_off;
2004 
2005 		if (seg_i->alloc_type == SSR)
2006 			blk_off = sbi->blocks_per_seg;
2007 
2008 		for (j = 0; j < blk_off; j++) {
2009 			struct f2fs_summary *s;
2010 			s = (struct f2fs_summary *)(kaddr + offset);
2011 			seg_i->sum_blk->entries[j] = *s;
2012 			offset += SUMMARY_SIZE;
2013 			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
2014 						SUM_FOOTER_SIZE)
2015 				continue;
2016 
2017 			f2fs_put_page(page, 1);
2018 			page = NULL;
2019 
2020 			page = get_meta_page(sbi, start++);
2021 			kaddr = (unsigned char *)page_address(page);
2022 			offset = 0;
2023 		}
2024 	}
2025 	f2fs_put_page(page, 1);
2026 	return 0;
2027 }
2028 
2029 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
2030 {
2031 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2032 	struct f2fs_summary_block *sum;
2033 	struct curseg_info *curseg;
2034 	struct page *new;
2035 	unsigned short blk_off;
2036 	unsigned int segno = 0;
2037 	block_t blk_addr = 0;
2038 
2039 	/* get segment number and block addr */
2040 	if (IS_DATASEG(type)) {
2041 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
2042 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
2043 							CURSEG_HOT_DATA]);
2044 		if (__exist_node_summaries(sbi))
2045 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
2046 		else
2047 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
2048 	} else {
2049 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
2050 							CURSEG_HOT_NODE]);
2051 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
2052 							CURSEG_HOT_NODE]);
2053 		if (__exist_node_summaries(sbi))
2054 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
2055 							type - CURSEG_HOT_NODE);
2056 		else
2057 			blk_addr = GET_SUM_BLOCK(sbi, segno);
2058 	}
2059 
2060 	new = get_meta_page(sbi, blk_addr);
2061 	sum = (struct f2fs_summary_block *)page_address(new);
2062 
2063 	if (IS_NODESEG(type)) {
2064 		if (__exist_node_summaries(sbi)) {
2065 			struct f2fs_summary *ns = &sum->entries[0];
2066 			int i;
2067 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
2068 				ns->version = 0;
2069 				ns->ofs_in_node = 0;
2070 			}
2071 		} else {
2072 			int err;
2073 
2074 			err = restore_node_summary(sbi, segno, sum);
2075 			if (err) {
2076 				f2fs_put_page(new, 1);
2077 				return err;
2078 			}
2079 		}
2080 	}
2081 
2082 	/* set uncompleted segment to curseg */
2083 	curseg = CURSEG_I(sbi, type);
2084 	mutex_lock(&curseg->curseg_mutex);
2085 
2086 	/* update journal info */
2087 	down_write(&curseg->journal_rwsem);
2088 	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
2089 	up_write(&curseg->journal_rwsem);
2090 
2091 	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
2092 	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
2093 	curseg->next_segno = segno;
2094 	reset_curseg(sbi, type, 0);
2095 	curseg->alloc_type = ckpt->alloc_type[type];
2096 	curseg->next_blkoff = blk_off;
2097 	mutex_unlock(&curseg->curseg_mutex);
2098 	f2fs_put_page(new, 1);
2099 	return 0;
2100 }
2101 
2102 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
2103 {
2104 	int type = CURSEG_HOT_DATA;
2105 	int err;
2106 
2107 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
2108 		int npages = npages_for_summary_flush(sbi, true);
2109 
2110 		if (npages >= 2)
2111 			ra_meta_pages(sbi, start_sum_block(sbi), npages,
2112 							META_CP, true);
2113 
2114 		/* restore for compacted data summary */
2115 		if (read_compacted_summaries(sbi))
2116 			return -EINVAL;
2117 		type = CURSEG_HOT_NODE;
2118 	}
2119 
2120 	if (__exist_node_summaries(sbi))
2121 		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
2122 					NR_CURSEG_TYPE - type, META_CP, true);
2123 
2124 	for (; type <= CURSEG_COLD_NODE; type++) {
2125 		err = read_normal_summaries(sbi, type);
2126 		if (err)
2127 			return err;
2128 	}
2129 
2130 	return 0;
2131 }
2132 
2133 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
2134 {
2135 	struct page *page;
2136 	unsigned char *kaddr;
2137 	struct f2fs_summary *summary;
2138 	struct curseg_info *seg_i;
2139 	int written_size = 0;
2140 	int i, j;
2141 
2142 	page = grab_meta_page(sbi, blkaddr++);
2143 	kaddr = (unsigned char *)page_address(page);
2144 
2145 	/* Step 1: write nat cache */
2146 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
2147 	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
2148 	written_size += SUM_JOURNAL_SIZE;
2149 
2150 	/* Step 2: write sit cache */
2151 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
2152 	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
2153 	written_size += SUM_JOURNAL_SIZE;
2154 
2155 	/* Step 3: write summary entries */
2156 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2157 		unsigned short blkoff;
2158 		seg_i = CURSEG_I(sbi, i);
2159 		if (sbi->ckpt->alloc_type[i] == SSR)
2160 			blkoff = sbi->blocks_per_seg;
2161 		else
2162 			blkoff = curseg_blkoff(sbi, i);
2163 
2164 		for (j = 0; j < blkoff; j++) {
2165 			if (!page) {
2166 				page = grab_meta_page(sbi, blkaddr++);
2167 				kaddr = (unsigned char *)page_address(page);
2168 				written_size = 0;
2169 			}
2170 			summary = (struct f2fs_summary *)(kaddr + written_size);
2171 			*summary = seg_i->sum_blk->entries[j];
2172 			written_size += SUMMARY_SIZE;
2173 
2174 			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
2175 							SUM_FOOTER_SIZE)
2176 				continue;
2177 
2178 			set_page_dirty(page);
2179 			f2fs_put_page(page, 1);
2180 			page = NULL;
2181 		}
2182 	}
2183 	if (page) {
2184 		set_page_dirty(page);
2185 		f2fs_put_page(page, 1);
2186 	}
2187 }
2188 
2189 static void write_normal_summaries(struct f2fs_sb_info *sbi,
2190 					block_t blkaddr, int type)
2191 {
2192 	int i, end;
2193 	if (IS_DATASEG(type))
2194 		end = type + NR_CURSEG_DATA_TYPE;
2195 	else
2196 		end = type + NR_CURSEG_NODE_TYPE;
2197 
2198 	for (i = type; i < end; i++)
2199 		write_current_sum_page(sbi, i, blkaddr + (i - type));
2200 }
2201 
2202 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2203 {
2204 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
2205 		write_compacted_summaries(sbi, start_blk);
2206 	else
2207 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
2208 }
2209 
2210 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
2211 {
2212 	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
2213 }
2214 
2215 int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
2216 					unsigned int val, int alloc)
2217 {
2218 	int i;
2219 
2220 	if (type == NAT_JOURNAL) {
2221 		for (i = 0; i < nats_in_cursum(journal); i++) {
2222 			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
2223 				return i;
2224 		}
2225 		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
2226 			return update_nats_in_cursum(journal, 1);
2227 	} else if (type == SIT_JOURNAL) {
2228 		for (i = 0; i < sits_in_cursum(journal); i++)
2229 			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
2230 				return i;
2231 		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
2232 			return update_sits_in_cursum(journal, 1);
2233 	}
2234 	return -1;
2235 }
2236 
2237 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
2238 					unsigned int segno)
2239 {
2240 	return get_meta_page(sbi, current_sit_addr(sbi, segno));
2241 }
2242 
2243 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
2244 					unsigned int start)
2245 {
2246 	struct sit_info *sit_i = SIT_I(sbi);
2247 	struct page *src_page, *dst_page;
2248 	pgoff_t src_off, dst_off;
2249 	void *src_addr, *dst_addr;
2250 
2251 	src_off = current_sit_addr(sbi, start);
2252 	dst_off = next_sit_addr(sbi, src_off);
2253 
2254 	/* get current sit block page without lock */
2255 	src_page = get_meta_page(sbi, src_off);
2256 	dst_page = grab_meta_page(sbi, dst_off);
2257 	f2fs_bug_on(sbi, PageDirty(src_page));
2258 
2259 	src_addr = page_address(src_page);
2260 	dst_addr = page_address(dst_page);
2261 	memcpy(dst_addr, src_addr, PAGE_SIZE);
2262 
2263 	set_page_dirty(dst_page);
2264 	f2fs_put_page(src_page, 1);
2265 
2266 	set_to_next_sit(sit_i, start);
2267 
2268 	return dst_page;
2269 }
2270 
2271 static struct sit_entry_set *grab_sit_entry_set(void)
2272 {
2273 	struct sit_entry_set *ses =
2274 			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
2275 
2276 	ses->entry_cnt = 0;
2277 	INIT_LIST_HEAD(&ses->set_list);
2278 	return ses;
2279 }
2280 
2281 static void release_sit_entry_set(struct sit_entry_set *ses)
2282 {
2283 	list_del(&ses->set_list);
2284 	kmem_cache_free(sit_entry_set_slab, ses);
2285 }
2286 
2287 static void adjust_sit_entry_set(struct sit_entry_set *ses,
2288 						struct list_head *head)
2289 {
2290 	struct sit_entry_set *next = ses;
2291 
2292 	if (list_is_last(&ses->set_list, head))
2293 		return;
2294 
2295 	list_for_each_entry_continue(next, head, set_list)
2296 		if (ses->entry_cnt <= next->entry_cnt)
2297 			break;
2298 
2299 	list_move_tail(&ses->set_list, &next->set_list);
2300 }
2301 
2302 static void add_sit_entry(unsigned int segno, struct list_head *head)
2303 {
2304 	struct sit_entry_set *ses;
2305 	unsigned int start_segno = START_SEGNO(segno);
2306 
2307 	list_for_each_entry(ses, head, set_list) {
2308 		if (ses->start_segno == start_segno) {
2309 			ses->entry_cnt++;
2310 			adjust_sit_entry_set(ses, head);
2311 			return;
2312 		}
2313 	}
2314 
2315 	ses = grab_sit_entry_set();
2316 
2317 	ses->start_segno = start_segno;
2318 	ses->entry_cnt++;
2319 	list_add(&ses->set_list, head);
2320 }
2321 
2322 static void add_sits_in_set(struct f2fs_sb_info *sbi)
2323 {
2324 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2325 	struct list_head *set_list = &sm_info->sit_entry_set;
2326 	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
2327 	unsigned int segno;
2328 
2329 	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
2330 		add_sit_entry(segno, set_list);
2331 }
2332 
2333 static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
2334 {
2335 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2336 	struct f2fs_journal *journal = curseg->journal;
2337 	int i;
2338 
2339 	down_write(&curseg->journal_rwsem);
2340 	for (i = 0; i < sits_in_cursum(journal); i++) {
2341 		unsigned int segno;
2342 		bool dirtied;
2343 
2344 		segno = le32_to_cpu(segno_in_journal(journal, i));
2345 		dirtied = __mark_sit_entry_dirty(sbi, segno);
2346 
2347 		if (!dirtied)
2348 			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
2349 	}
2350 	update_sits_in_cursum(journal, -i);
2351 	up_write(&curseg->journal_rwsem);
2352 }
2353 
2354 /*
2355  * CP calls this function, which flushes SIT entries including sit_journal,
2356  * and moves prefree segs to free segs.
2357  */
2358 void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
2359 {
2360 	struct sit_info *sit_i = SIT_I(sbi);
2361 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
2362 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2363 	struct f2fs_journal *journal = curseg->journal;
2364 	struct sit_entry_set *ses, *tmp;
2365 	struct list_head *head = &SM_I(sbi)->sit_entry_set;
2366 	bool to_journal = true;
2367 	struct seg_entry *se;
2368 
2369 	mutex_lock(&sit_i->sentry_lock);
2370 
2371 	if (!sit_i->dirty_sentries)
2372 		goto out;
2373 
2374 	/*
2375 	 * add and account sit entries of dirty bitmap in sit entry
2376 	 * set temporarily
2377 	 */
2378 	add_sits_in_set(sbi);
2379 
2380 	/*
2381 	 * if there are no enough space in journal to store dirty sit
2382 	 * entries, remove all entries from journal and add and account
2383 	 * them in sit entry set.
2384 	 */
2385 	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
2386 		remove_sits_in_journal(sbi);
2387 
2388 	/*
2389 	 * there are two steps to flush sit entries:
2390 	 * #1, flush sit entries to journal in current cold data summary block.
2391 	 * #2, flush sit entries to sit page.
2392 	 */
2393 	list_for_each_entry_safe(ses, tmp, head, set_list) {
2394 		struct page *page = NULL;
2395 		struct f2fs_sit_block *raw_sit = NULL;
2396 		unsigned int start_segno = ses->start_segno;
2397 		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
2398 						(unsigned long)MAIN_SEGS(sbi));
2399 		unsigned int segno = start_segno;
2400 
2401 		if (to_journal &&
2402 			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
2403 			to_journal = false;
2404 
2405 		if (to_journal) {
2406 			down_write(&curseg->journal_rwsem);
2407 		} else {
2408 			page = get_next_sit_page(sbi, start_segno);
2409 			raw_sit = page_address(page);
2410 		}
2411 
2412 		/* flush dirty sit entries in region of current sit set */
2413 		for_each_set_bit_from(segno, bitmap, end) {
2414 			int offset, sit_offset;
2415 
2416 			se = get_seg_entry(sbi, segno);
2417 
2418 			/* add discard candidates */
2419 			if (cpc->reason != CP_DISCARD) {
2420 				cpc->trim_start = segno;
2421 				add_discard_addrs(sbi, cpc, false);
2422 			}
2423 
2424 			if (to_journal) {
2425 				offset = lookup_journal_in_cursum(journal,
2426 							SIT_JOURNAL, segno, 1);
2427 				f2fs_bug_on(sbi, offset < 0);
2428 				segno_in_journal(journal, offset) =
2429 							cpu_to_le32(segno);
2430 				seg_info_to_raw_sit(se,
2431 					&sit_in_journal(journal, offset));
2432 			} else {
2433 				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
2434 				seg_info_to_raw_sit(se,
2435 						&raw_sit->entries[sit_offset]);
2436 			}
2437 
2438 			__clear_bit(segno, bitmap);
2439 			sit_i->dirty_sentries--;
2440 			ses->entry_cnt--;
2441 		}
2442 
2443 		if (to_journal)
2444 			up_write(&curseg->journal_rwsem);
2445 		else
2446 			f2fs_put_page(page, 1);
2447 
2448 		f2fs_bug_on(sbi, ses->entry_cnt);
2449 		release_sit_entry_set(ses);
2450 	}
2451 
2452 	f2fs_bug_on(sbi, !list_empty(head));
2453 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
2454 out:
2455 	if (cpc->reason == CP_DISCARD) {
2456 		__u64 trim_start = cpc->trim_start;
2457 
2458 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
2459 			add_discard_addrs(sbi, cpc, false);
2460 
2461 		cpc->trim_start = trim_start;
2462 	}
2463 	mutex_unlock(&sit_i->sentry_lock);
2464 
2465 	set_prefree_as_free_segments(sbi);
2466 }
2467 
2468 static int build_sit_info(struct f2fs_sb_info *sbi)
2469 {
2470 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2471 	struct sit_info *sit_i;
2472 	unsigned int sit_segs, start;
2473 	char *src_bitmap;
2474 	unsigned int bitmap_size;
2475 
2476 	/* allocate memory for SIT information */
2477 	sit_i = kzalloc(sizeof(struct sit_info), GFP_KERNEL);
2478 	if (!sit_i)
2479 		return -ENOMEM;
2480 
2481 	SM_I(sbi)->sit_info = sit_i;
2482 
2483 	sit_i->sentries = f2fs_kvzalloc(MAIN_SEGS(sbi) *
2484 					sizeof(struct seg_entry), GFP_KERNEL);
2485 	if (!sit_i->sentries)
2486 		return -ENOMEM;
2487 
2488 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2489 	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2490 	if (!sit_i->dirty_sentries_bitmap)
2491 		return -ENOMEM;
2492 
2493 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2494 		sit_i->sentries[start].cur_valid_map
2495 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2496 		sit_i->sentries[start].ckpt_valid_map
2497 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2498 		if (!sit_i->sentries[start].cur_valid_map ||
2499 				!sit_i->sentries[start].ckpt_valid_map)
2500 			return -ENOMEM;
2501 
2502 #ifdef CONFIG_F2FS_CHECK_FS
2503 		sit_i->sentries[start].cur_valid_map_mir
2504 			= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2505 		if (!sit_i->sentries[start].cur_valid_map_mir)
2506 			return -ENOMEM;
2507 #endif
2508 
2509 		if (f2fs_discard_en(sbi)) {
2510 			sit_i->sentries[start].discard_map
2511 				= kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2512 			if (!sit_i->sentries[start].discard_map)
2513 				return -ENOMEM;
2514 		}
2515 	}
2516 
2517 	sit_i->tmp_map = kzalloc(SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
2518 	if (!sit_i->tmp_map)
2519 		return -ENOMEM;
2520 
2521 	if (sbi->segs_per_sec > 1) {
2522 		sit_i->sec_entries = f2fs_kvzalloc(MAIN_SECS(sbi) *
2523 					sizeof(struct sec_entry), GFP_KERNEL);
2524 		if (!sit_i->sec_entries)
2525 			return -ENOMEM;
2526 	}
2527 
2528 	/* get information related with SIT */
2529 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
2530 
2531 	/* setup SIT bitmap from ckeckpoint pack */
2532 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
2533 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
2534 
2535 	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2536 	if (!sit_i->sit_bitmap)
2537 		return -ENOMEM;
2538 
2539 #ifdef CONFIG_F2FS_CHECK_FS
2540 	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
2541 	if (!sit_i->sit_bitmap_mir)
2542 		return -ENOMEM;
2543 #endif
2544 
2545 	/* init SIT information */
2546 	sit_i->s_ops = &default_salloc_ops;
2547 
2548 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
2549 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
2550 	sit_i->written_valid_blocks = 0;
2551 	sit_i->bitmap_size = bitmap_size;
2552 	sit_i->dirty_sentries = 0;
2553 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
2554 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
2555 	sit_i->mounted_time = CURRENT_TIME_SEC.tv_sec;
2556 	mutex_init(&sit_i->sentry_lock);
2557 	return 0;
2558 }
2559 
2560 static int build_free_segmap(struct f2fs_sb_info *sbi)
2561 {
2562 	struct free_segmap_info *free_i;
2563 	unsigned int bitmap_size, sec_bitmap_size;
2564 
2565 	/* allocate memory for free segmap information */
2566 	free_i = kzalloc(sizeof(struct free_segmap_info), GFP_KERNEL);
2567 	if (!free_i)
2568 		return -ENOMEM;
2569 
2570 	SM_I(sbi)->free_info = free_i;
2571 
2572 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2573 	free_i->free_segmap = f2fs_kvmalloc(bitmap_size, GFP_KERNEL);
2574 	if (!free_i->free_segmap)
2575 		return -ENOMEM;
2576 
2577 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2578 	free_i->free_secmap = f2fs_kvmalloc(sec_bitmap_size, GFP_KERNEL);
2579 	if (!free_i->free_secmap)
2580 		return -ENOMEM;
2581 
2582 	/* set all segments as dirty temporarily */
2583 	memset(free_i->free_segmap, 0xff, bitmap_size);
2584 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
2585 
2586 	/* init free segmap information */
2587 	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
2588 	free_i->free_segments = 0;
2589 	free_i->free_sections = 0;
2590 	spin_lock_init(&free_i->segmap_lock);
2591 	return 0;
2592 }
2593 
2594 static int build_curseg(struct f2fs_sb_info *sbi)
2595 {
2596 	struct curseg_info *array;
2597 	int i;
2598 
2599 	array = kcalloc(NR_CURSEG_TYPE, sizeof(*array), GFP_KERNEL);
2600 	if (!array)
2601 		return -ENOMEM;
2602 
2603 	SM_I(sbi)->curseg_array = array;
2604 
2605 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2606 		mutex_init(&array[i].curseg_mutex);
2607 		array[i].sum_blk = kzalloc(PAGE_SIZE, GFP_KERNEL);
2608 		if (!array[i].sum_blk)
2609 			return -ENOMEM;
2610 		init_rwsem(&array[i].journal_rwsem);
2611 		array[i].journal = kzalloc(sizeof(struct f2fs_journal),
2612 							GFP_KERNEL);
2613 		if (!array[i].journal)
2614 			return -ENOMEM;
2615 		array[i].segno = NULL_SEGNO;
2616 		array[i].next_blkoff = 0;
2617 	}
2618 	return restore_curseg_summaries(sbi);
2619 }
2620 
2621 static void build_sit_entries(struct f2fs_sb_info *sbi)
2622 {
2623 	struct sit_info *sit_i = SIT_I(sbi);
2624 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
2625 	struct f2fs_journal *journal = curseg->journal;
2626 	struct seg_entry *se;
2627 	struct f2fs_sit_entry sit;
2628 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
2629 	unsigned int i, start, end;
2630 	unsigned int readed, start_blk = 0;
2631 
2632 	do {
2633 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
2634 							META_SIT, true);
2635 
2636 		start = start_blk * sit_i->sents_per_block;
2637 		end = (start_blk + readed) * sit_i->sents_per_block;
2638 
2639 		for (; start < end && start < MAIN_SEGS(sbi); start++) {
2640 			struct f2fs_sit_block *sit_blk;
2641 			struct page *page;
2642 
2643 			se = &sit_i->sentries[start];
2644 			page = get_current_sit_page(sbi, start);
2645 			sit_blk = (struct f2fs_sit_block *)page_address(page);
2646 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
2647 			f2fs_put_page(page, 1);
2648 
2649 			check_block_count(sbi, start, &sit);
2650 			seg_info_from_raw_sit(se, &sit);
2651 
2652 			/* build discard map only one time */
2653 			if (f2fs_discard_en(sbi)) {
2654 				memcpy(se->discard_map, se->cur_valid_map,
2655 							SIT_VBLOCK_MAP_SIZE);
2656 				sbi->discard_blks += sbi->blocks_per_seg -
2657 							se->valid_blocks;
2658 			}
2659 
2660 			if (sbi->segs_per_sec > 1)
2661 				get_sec_entry(sbi, start)->valid_blocks +=
2662 							se->valid_blocks;
2663 		}
2664 		start_blk += readed;
2665 	} while (start_blk < sit_blk_cnt);
2666 
2667 	down_read(&curseg->journal_rwsem);
2668 	for (i = 0; i < sits_in_cursum(journal); i++) {
2669 		unsigned int old_valid_blocks;
2670 
2671 		start = le32_to_cpu(segno_in_journal(journal, i));
2672 		se = &sit_i->sentries[start];
2673 		sit = sit_in_journal(journal, i);
2674 
2675 		old_valid_blocks = se->valid_blocks;
2676 
2677 		check_block_count(sbi, start, &sit);
2678 		seg_info_from_raw_sit(se, &sit);
2679 
2680 		if (f2fs_discard_en(sbi)) {
2681 			memcpy(se->discard_map, se->cur_valid_map,
2682 						SIT_VBLOCK_MAP_SIZE);
2683 			sbi->discard_blks += old_valid_blocks -
2684 						se->valid_blocks;
2685 		}
2686 
2687 		if (sbi->segs_per_sec > 1)
2688 			get_sec_entry(sbi, start)->valid_blocks +=
2689 				se->valid_blocks - old_valid_blocks;
2690 	}
2691 	up_read(&curseg->journal_rwsem);
2692 }
2693 
2694 static void init_free_segmap(struct f2fs_sb_info *sbi)
2695 {
2696 	unsigned int start;
2697 	int type;
2698 
2699 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
2700 		struct seg_entry *sentry = get_seg_entry(sbi, start);
2701 		if (!sentry->valid_blocks)
2702 			__set_free(sbi, start);
2703 		else
2704 			SIT_I(sbi)->written_valid_blocks +=
2705 						sentry->valid_blocks;
2706 	}
2707 
2708 	/* set use the current segments */
2709 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
2710 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
2711 		__set_test_and_inuse(sbi, curseg_t->segno);
2712 	}
2713 }
2714 
2715 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
2716 {
2717 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2718 	struct free_segmap_info *free_i = FREE_I(sbi);
2719 	unsigned int segno = 0, offset = 0;
2720 	unsigned short valid_blocks;
2721 
2722 	while (1) {
2723 		/* find dirty segment based on free segmap */
2724 		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
2725 		if (segno >= MAIN_SEGS(sbi))
2726 			break;
2727 		offset = segno + 1;
2728 		valid_blocks = get_valid_blocks(sbi, segno, 0);
2729 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
2730 			continue;
2731 		if (valid_blocks > sbi->blocks_per_seg) {
2732 			f2fs_bug_on(sbi, 1);
2733 			continue;
2734 		}
2735 		mutex_lock(&dirty_i->seglist_lock);
2736 		__locate_dirty_segment(sbi, segno, DIRTY);
2737 		mutex_unlock(&dirty_i->seglist_lock);
2738 	}
2739 }
2740 
2741 static int init_victim_secmap(struct f2fs_sb_info *sbi)
2742 {
2743 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2744 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
2745 
2746 	dirty_i->victim_secmap = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2747 	if (!dirty_i->victim_secmap)
2748 		return -ENOMEM;
2749 	return 0;
2750 }
2751 
2752 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
2753 {
2754 	struct dirty_seglist_info *dirty_i;
2755 	unsigned int bitmap_size, i;
2756 
2757 	/* allocate memory for dirty segments list information */
2758 	dirty_i = kzalloc(sizeof(struct dirty_seglist_info), GFP_KERNEL);
2759 	if (!dirty_i)
2760 		return -ENOMEM;
2761 
2762 	SM_I(sbi)->dirty_info = dirty_i;
2763 	mutex_init(&dirty_i->seglist_lock);
2764 
2765 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
2766 
2767 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
2768 		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(bitmap_size, GFP_KERNEL);
2769 		if (!dirty_i->dirty_segmap[i])
2770 			return -ENOMEM;
2771 	}
2772 
2773 	init_dirty_segmap(sbi);
2774 	return init_victim_secmap(sbi);
2775 }
2776 
2777 /*
2778  * Update min, max modified time for cost-benefit GC algorithm
2779  */
2780 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
2781 {
2782 	struct sit_info *sit_i = SIT_I(sbi);
2783 	unsigned int segno;
2784 
2785 	mutex_lock(&sit_i->sentry_lock);
2786 
2787 	sit_i->min_mtime = LLONG_MAX;
2788 
2789 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
2790 		unsigned int i;
2791 		unsigned long long mtime = 0;
2792 
2793 		for (i = 0; i < sbi->segs_per_sec; i++)
2794 			mtime += get_seg_entry(sbi, segno + i)->mtime;
2795 
2796 		mtime = div_u64(mtime, sbi->segs_per_sec);
2797 
2798 		if (sit_i->min_mtime > mtime)
2799 			sit_i->min_mtime = mtime;
2800 	}
2801 	sit_i->max_mtime = get_mtime(sbi);
2802 	mutex_unlock(&sit_i->sentry_lock);
2803 }
2804 
2805 int build_segment_manager(struct f2fs_sb_info *sbi)
2806 {
2807 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
2808 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2809 	struct f2fs_sm_info *sm_info;
2810 	int err;
2811 
2812 	sm_info = kzalloc(sizeof(struct f2fs_sm_info), GFP_KERNEL);
2813 	if (!sm_info)
2814 		return -ENOMEM;
2815 
2816 	/* init sm info */
2817 	sbi->sm_info = sm_info;
2818 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
2819 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
2820 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
2821 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
2822 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
2823 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
2824 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
2825 	sm_info->rec_prefree_segments = sm_info->main_segments *
2826 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
2827 	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
2828 		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
2829 
2830 	if (!test_opt(sbi, LFS))
2831 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
2832 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
2833 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
2834 
2835 	sm_info->trim_sections = DEF_BATCHED_TRIM_SECTIONS;
2836 
2837 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
2838 
2839 	if (test_opt(sbi, FLUSH_MERGE) && !f2fs_readonly(sbi->sb)) {
2840 		err = create_flush_cmd_control(sbi);
2841 		if (err)
2842 			return err;
2843 	}
2844 
2845 	err = create_discard_cmd_control(sbi);
2846 	if (err)
2847 		return err;
2848 
2849 	err = build_sit_info(sbi);
2850 	if (err)
2851 		return err;
2852 	err = build_free_segmap(sbi);
2853 	if (err)
2854 		return err;
2855 	err = build_curseg(sbi);
2856 	if (err)
2857 		return err;
2858 
2859 	/* reinit free segmap based on SIT */
2860 	build_sit_entries(sbi);
2861 
2862 	init_free_segmap(sbi);
2863 	err = build_dirty_segmap(sbi);
2864 	if (err)
2865 		return err;
2866 
2867 	init_min_max_mtime(sbi);
2868 	return 0;
2869 }
2870 
2871 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
2872 		enum dirty_type dirty_type)
2873 {
2874 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2875 
2876 	mutex_lock(&dirty_i->seglist_lock);
2877 	kvfree(dirty_i->dirty_segmap[dirty_type]);
2878 	dirty_i->nr_dirty[dirty_type] = 0;
2879 	mutex_unlock(&dirty_i->seglist_lock);
2880 }
2881 
2882 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
2883 {
2884 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2885 	kvfree(dirty_i->victim_secmap);
2886 }
2887 
2888 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
2889 {
2890 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2891 	int i;
2892 
2893 	if (!dirty_i)
2894 		return;
2895 
2896 	/* discard pre-free/dirty segments list */
2897 	for (i = 0; i < NR_DIRTY_TYPE; i++)
2898 		discard_dirty_segmap(sbi, i);
2899 
2900 	destroy_victim_secmap(sbi);
2901 	SM_I(sbi)->dirty_info = NULL;
2902 	kfree(dirty_i);
2903 }
2904 
2905 static void destroy_curseg(struct f2fs_sb_info *sbi)
2906 {
2907 	struct curseg_info *array = SM_I(sbi)->curseg_array;
2908 	int i;
2909 
2910 	if (!array)
2911 		return;
2912 	SM_I(sbi)->curseg_array = NULL;
2913 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
2914 		kfree(array[i].sum_blk);
2915 		kfree(array[i].journal);
2916 	}
2917 	kfree(array);
2918 }
2919 
2920 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
2921 {
2922 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
2923 	if (!free_i)
2924 		return;
2925 	SM_I(sbi)->free_info = NULL;
2926 	kvfree(free_i->free_segmap);
2927 	kvfree(free_i->free_secmap);
2928 	kfree(free_i);
2929 }
2930 
2931 static void destroy_sit_info(struct f2fs_sb_info *sbi)
2932 {
2933 	struct sit_info *sit_i = SIT_I(sbi);
2934 	unsigned int start;
2935 
2936 	if (!sit_i)
2937 		return;
2938 
2939 	if (sit_i->sentries) {
2940 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
2941 			kfree(sit_i->sentries[start].cur_valid_map);
2942 #ifdef CONFIG_F2FS_CHECK_FS
2943 			kfree(sit_i->sentries[start].cur_valid_map_mir);
2944 #endif
2945 			kfree(sit_i->sentries[start].ckpt_valid_map);
2946 			kfree(sit_i->sentries[start].discard_map);
2947 		}
2948 	}
2949 	kfree(sit_i->tmp_map);
2950 
2951 	kvfree(sit_i->sentries);
2952 	kvfree(sit_i->sec_entries);
2953 	kvfree(sit_i->dirty_sentries_bitmap);
2954 
2955 	SM_I(sbi)->sit_info = NULL;
2956 	kfree(sit_i->sit_bitmap);
2957 #ifdef CONFIG_F2FS_CHECK_FS
2958 	kfree(sit_i->sit_bitmap_mir);
2959 #endif
2960 	kfree(sit_i);
2961 }
2962 
2963 void destroy_segment_manager(struct f2fs_sb_info *sbi)
2964 {
2965 	struct f2fs_sm_info *sm_info = SM_I(sbi);
2966 
2967 	if (!sm_info)
2968 		return;
2969 	destroy_flush_cmd_control(sbi, true);
2970 	destroy_discard_cmd_control(sbi, true);
2971 	destroy_dirty_segmap(sbi);
2972 	destroy_curseg(sbi);
2973 	destroy_free_segmap(sbi);
2974 	destroy_sit_info(sbi);
2975 	sbi->sm_info = NULL;
2976 	kfree(sm_info);
2977 }
2978 
2979 int __init create_segment_manager_caches(void)
2980 {
2981 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
2982 			sizeof(struct discard_entry));
2983 	if (!discard_entry_slab)
2984 		goto fail;
2985 
2986 	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
2987 			sizeof(struct discard_cmd));
2988 	if (!discard_cmd_slab)
2989 		goto destroy_discard_entry;
2990 
2991 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
2992 			sizeof(struct sit_entry_set));
2993 	if (!sit_entry_set_slab)
2994 		goto destroy_discard_cmd;
2995 
2996 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
2997 			sizeof(struct inmem_pages));
2998 	if (!inmem_entry_slab)
2999 		goto destroy_sit_entry_set;
3000 	return 0;
3001 
3002 destroy_sit_entry_set:
3003 	kmem_cache_destroy(sit_entry_set_slab);
3004 destroy_discard_cmd:
3005 	kmem_cache_destroy(discard_cmd_slab);
3006 destroy_discard_entry:
3007 	kmem_cache_destroy(discard_entry_slab);
3008 fail:
3009 	return -ENOMEM;
3010 }
3011 
3012 void destroy_segment_manager_caches(void)
3013 {
3014 	kmem_cache_destroy(sit_entry_set_slab);
3015 	kmem_cache_destroy(discard_cmd_slab);
3016 	kmem_cache_destroy(discard_entry_slab);
3017 	kmem_cache_destroy(inmem_entry_slab);
3018 }
3019