xref: /openbmc/linux/fs/f2fs/segment.c (revision 2ef79ecb5e906d87475d3e0c49b22425499a89f3)
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 #include <linux/freezer.h>
20 #include <linux/sched/signal.h>
21 
22 #include "f2fs.h"
23 #include "segment.h"
24 #include "node.h"
25 #include "gc.h"
26 #include "trace.h"
27 #include <trace/events/f2fs.h>
28 
29 #define __reverse_ffz(x) __reverse_ffs(~(x))
30 
31 static struct kmem_cache *discard_entry_slab;
32 static struct kmem_cache *discard_cmd_slab;
33 static struct kmem_cache *sit_entry_set_slab;
34 static struct kmem_cache *inmem_entry_slab;
35 
36 static unsigned long __reverse_ulong(unsigned char *str)
37 {
38 	unsigned long tmp = 0;
39 	int shift = 24, idx = 0;
40 
41 #if BITS_PER_LONG == 64
42 	shift = 56;
43 #endif
44 	while (shift >= 0) {
45 		tmp |= (unsigned long)str[idx++] << shift;
46 		shift -= BITS_PER_BYTE;
47 	}
48 	return tmp;
49 }
50 
51 /*
52  * __reverse_ffs is copied from include/asm-generic/bitops/__ffs.h since
53  * MSB and LSB are reversed in a byte by f2fs_set_bit.
54  */
55 static inline unsigned long __reverse_ffs(unsigned long word)
56 {
57 	int num = 0;
58 
59 #if BITS_PER_LONG == 64
60 	if ((word & 0xffffffff00000000UL) == 0)
61 		num += 32;
62 	else
63 		word >>= 32;
64 #endif
65 	if ((word & 0xffff0000) == 0)
66 		num += 16;
67 	else
68 		word >>= 16;
69 
70 	if ((word & 0xff00) == 0)
71 		num += 8;
72 	else
73 		word >>= 8;
74 
75 	if ((word & 0xf0) == 0)
76 		num += 4;
77 	else
78 		word >>= 4;
79 
80 	if ((word & 0xc) == 0)
81 		num += 2;
82 	else
83 		word >>= 2;
84 
85 	if ((word & 0x2) == 0)
86 		num += 1;
87 	return num;
88 }
89 
90 /*
91  * __find_rev_next(_zero)_bit is copied from lib/find_next_bit.c because
92  * f2fs_set_bit makes MSB and LSB reversed in a byte.
93  * @size must be integral times of unsigned long.
94  * Example:
95  *                             MSB <--> LSB
96  *   f2fs_set_bit(0, bitmap) => 1000 0000
97  *   f2fs_set_bit(7, bitmap) => 0000 0001
98  */
99 static unsigned long __find_rev_next_bit(const unsigned long *addr,
100 			unsigned long size, unsigned long offset)
101 {
102 	const unsigned long *p = addr + BIT_WORD(offset);
103 	unsigned long result = size;
104 	unsigned long tmp;
105 
106 	if (offset >= size)
107 		return size;
108 
109 	size -= (offset & ~(BITS_PER_LONG - 1));
110 	offset %= BITS_PER_LONG;
111 
112 	while (1) {
113 		if (*p == 0)
114 			goto pass;
115 
116 		tmp = __reverse_ulong((unsigned char *)p);
117 
118 		tmp &= ~0UL >> offset;
119 		if (size < BITS_PER_LONG)
120 			tmp &= (~0UL << (BITS_PER_LONG - size));
121 		if (tmp)
122 			goto found;
123 pass:
124 		if (size <= BITS_PER_LONG)
125 			break;
126 		size -= BITS_PER_LONG;
127 		offset = 0;
128 		p++;
129 	}
130 	return result;
131 found:
132 	return result - size + __reverse_ffs(tmp);
133 }
134 
135 static unsigned long __find_rev_next_zero_bit(const unsigned long *addr,
136 			unsigned long size, unsigned long offset)
137 {
138 	const unsigned long *p = addr + BIT_WORD(offset);
139 	unsigned long result = size;
140 	unsigned long tmp;
141 
142 	if (offset >= size)
143 		return size;
144 
145 	size -= (offset & ~(BITS_PER_LONG - 1));
146 	offset %= BITS_PER_LONG;
147 
148 	while (1) {
149 		if (*p == ~0UL)
150 			goto pass;
151 
152 		tmp = __reverse_ulong((unsigned char *)p);
153 
154 		if (offset)
155 			tmp |= ~0UL << (BITS_PER_LONG - offset);
156 		if (size < BITS_PER_LONG)
157 			tmp |= ~0UL >> size;
158 		if (tmp != ~0UL)
159 			goto found;
160 pass:
161 		if (size <= BITS_PER_LONG)
162 			break;
163 		size -= BITS_PER_LONG;
164 		offset = 0;
165 		p++;
166 	}
167 	return result;
168 found:
169 	return result - size + __reverse_ffz(tmp);
170 }
171 
172 bool need_SSR(struct f2fs_sb_info *sbi)
173 {
174 	int node_secs = get_blocktype_secs(sbi, F2FS_DIRTY_NODES);
175 	int dent_secs = get_blocktype_secs(sbi, F2FS_DIRTY_DENTS);
176 	int imeta_secs = get_blocktype_secs(sbi, F2FS_DIRTY_IMETA);
177 
178 	if (test_opt(sbi, LFS))
179 		return false;
180 	if (sbi->gc_mode == GC_URGENT)
181 		return true;
182 
183 	return free_sections(sbi) <= (node_secs + 2 * dent_secs + imeta_secs +
184 			SM_I(sbi)->min_ssr_sections + reserved_sections(sbi));
185 }
186 
187 void register_inmem_page(struct inode *inode, struct page *page)
188 {
189 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
190 	struct f2fs_inode_info *fi = F2FS_I(inode);
191 	struct inmem_pages *new;
192 
193 	f2fs_trace_pid(page);
194 
195 	set_page_private(page, (unsigned long)ATOMIC_WRITTEN_PAGE);
196 	SetPagePrivate(page);
197 
198 	new = f2fs_kmem_cache_alloc(inmem_entry_slab, GFP_NOFS);
199 
200 	/* add atomic page indices to the list */
201 	new->page = page;
202 	INIT_LIST_HEAD(&new->list);
203 
204 	/* increase reference count with clean state */
205 	mutex_lock(&fi->inmem_lock);
206 	get_page(page);
207 	list_add_tail(&new->list, &fi->inmem_pages);
208 	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
209 	if (list_empty(&fi->inmem_ilist))
210 		list_add_tail(&fi->inmem_ilist, &sbi->inode_list[ATOMIC_FILE]);
211 	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
212 	inc_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
213 	mutex_unlock(&fi->inmem_lock);
214 
215 	trace_f2fs_register_inmem_page(page, INMEM);
216 }
217 
218 static int __revoke_inmem_pages(struct inode *inode,
219 				struct list_head *head, bool drop, bool recover)
220 {
221 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
222 	struct inmem_pages *cur, *tmp;
223 	int err = 0;
224 
225 	list_for_each_entry_safe(cur, tmp, head, list) {
226 		struct page *page = cur->page;
227 
228 		if (drop)
229 			trace_f2fs_commit_inmem_page(page, INMEM_DROP);
230 
231 		lock_page(page);
232 
233 		f2fs_wait_on_page_writeback(page, DATA, true);
234 
235 		if (recover) {
236 			struct dnode_of_data dn;
237 			struct node_info ni;
238 
239 			trace_f2fs_commit_inmem_page(page, INMEM_REVOKE);
240 retry:
241 			set_new_dnode(&dn, inode, NULL, NULL, 0);
242 			err = get_dnode_of_data(&dn, page->index, LOOKUP_NODE);
243 			if (err) {
244 				if (err == -ENOMEM) {
245 					congestion_wait(BLK_RW_ASYNC, HZ/50);
246 					cond_resched();
247 					goto retry;
248 				}
249 				err = -EAGAIN;
250 				goto next;
251 			}
252 			get_node_info(sbi, dn.nid, &ni);
253 			if (cur->old_addr == NEW_ADDR) {
254 				invalidate_blocks(sbi, dn.data_blkaddr);
255 				f2fs_update_data_blkaddr(&dn, NEW_ADDR);
256 			} else
257 				f2fs_replace_block(sbi, &dn, dn.data_blkaddr,
258 					cur->old_addr, ni.version, true, true);
259 			f2fs_put_dnode(&dn);
260 		}
261 next:
262 		/* we don't need to invalidate this in the sccessful status */
263 		if (drop || recover)
264 			ClearPageUptodate(page);
265 		set_page_private(page, 0);
266 		ClearPagePrivate(page);
267 		f2fs_put_page(page, 1);
268 
269 		list_del(&cur->list);
270 		kmem_cache_free(inmem_entry_slab, cur);
271 		dec_page_count(F2FS_I_SB(inode), F2FS_INMEM_PAGES);
272 	}
273 	return err;
274 }
275 
276 void drop_inmem_pages_all(struct f2fs_sb_info *sbi, bool gc_failure)
277 {
278 	struct list_head *head = &sbi->inode_list[ATOMIC_FILE];
279 	struct inode *inode;
280 	struct f2fs_inode_info *fi;
281 next:
282 	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
283 	if (list_empty(head)) {
284 		spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
285 		return;
286 	}
287 	fi = list_first_entry(head, struct f2fs_inode_info, inmem_ilist);
288 	inode = igrab(&fi->vfs_inode);
289 	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
290 
291 	if (inode) {
292 		if (gc_failure) {
293 			if (fi->i_gc_failures[GC_FAILURE_ATOMIC])
294 				goto drop;
295 			goto skip;
296 		}
297 drop:
298 		set_inode_flag(inode, FI_ATOMIC_REVOKE_REQUEST);
299 		drop_inmem_pages(inode);
300 		iput(inode);
301 	}
302 skip:
303 	congestion_wait(BLK_RW_ASYNC, HZ/50);
304 	cond_resched();
305 	goto next;
306 }
307 
308 void drop_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 
313 	mutex_lock(&fi->inmem_lock);
314 	__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
315 	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
316 	if (!list_empty(&fi->inmem_ilist))
317 		list_del_init(&fi->inmem_ilist);
318 	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
319 	mutex_unlock(&fi->inmem_lock);
320 
321 	clear_inode_flag(inode, FI_ATOMIC_FILE);
322 	fi->i_gc_failures[GC_FAILURE_ATOMIC] = 0;
323 	stat_dec_atomic_write(inode);
324 }
325 
326 void drop_inmem_page(struct inode *inode, struct page *page)
327 {
328 	struct f2fs_inode_info *fi = F2FS_I(inode);
329 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
330 	struct list_head *head = &fi->inmem_pages;
331 	struct inmem_pages *cur = NULL;
332 
333 	f2fs_bug_on(sbi, !IS_ATOMIC_WRITTEN_PAGE(page));
334 
335 	mutex_lock(&fi->inmem_lock);
336 	list_for_each_entry(cur, head, list) {
337 		if (cur->page == page)
338 			break;
339 	}
340 
341 	f2fs_bug_on(sbi, list_empty(head) || cur->page != page);
342 	list_del(&cur->list);
343 	mutex_unlock(&fi->inmem_lock);
344 
345 	dec_page_count(sbi, F2FS_INMEM_PAGES);
346 	kmem_cache_free(inmem_entry_slab, cur);
347 
348 	ClearPageUptodate(page);
349 	set_page_private(page, 0);
350 	ClearPagePrivate(page);
351 	f2fs_put_page(page, 0);
352 
353 	trace_f2fs_commit_inmem_page(page, INMEM_INVALIDATE);
354 }
355 
356 static int __commit_inmem_pages(struct inode *inode)
357 {
358 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
359 	struct f2fs_inode_info *fi = F2FS_I(inode);
360 	struct inmem_pages *cur, *tmp;
361 	struct f2fs_io_info fio = {
362 		.sbi = sbi,
363 		.ino = inode->i_ino,
364 		.type = DATA,
365 		.op = REQ_OP_WRITE,
366 		.op_flags = REQ_SYNC | REQ_PRIO,
367 		.io_type = FS_DATA_IO,
368 	};
369 	struct list_head revoke_list;
370 	pgoff_t last_idx = ULONG_MAX;
371 	int err = 0;
372 
373 	INIT_LIST_HEAD(&revoke_list);
374 
375 	list_for_each_entry_safe(cur, tmp, &fi->inmem_pages, list) {
376 		struct page *page = cur->page;
377 
378 		lock_page(page);
379 		if (page->mapping == inode->i_mapping) {
380 			trace_f2fs_commit_inmem_page(page, INMEM);
381 
382 			set_page_dirty(page);
383 			f2fs_wait_on_page_writeback(page, DATA, true);
384 			if (clear_page_dirty_for_io(page)) {
385 				inode_dec_dirty_pages(inode);
386 				remove_dirty_inode(inode);
387 			}
388 retry:
389 			fio.page = page;
390 			fio.old_blkaddr = NULL_ADDR;
391 			fio.encrypted_page = NULL;
392 			fio.need_lock = LOCK_DONE;
393 			err = do_write_data_page(&fio);
394 			if (err) {
395 				if (err == -ENOMEM) {
396 					congestion_wait(BLK_RW_ASYNC, HZ/50);
397 					cond_resched();
398 					goto retry;
399 				}
400 				unlock_page(page);
401 				break;
402 			}
403 			/* record old blkaddr for revoking */
404 			cur->old_addr = fio.old_blkaddr;
405 			last_idx = page->index;
406 		}
407 		unlock_page(page);
408 		list_move_tail(&cur->list, &revoke_list);
409 	}
410 
411 	if (last_idx != ULONG_MAX)
412 		f2fs_submit_merged_write_cond(sbi, inode, 0, last_idx, DATA);
413 
414 	if (err) {
415 		/*
416 		 * try to revoke all committed pages, but still we could fail
417 		 * due to no memory or other reason, if that happened, EAGAIN
418 		 * will be returned, which means in such case, transaction is
419 		 * already not integrity, caller should use journal to do the
420 		 * recovery or rewrite & commit last transaction. For other
421 		 * error number, revoking was done by filesystem itself.
422 		 */
423 		err = __revoke_inmem_pages(inode, &revoke_list, false, true);
424 
425 		/* drop all uncommitted pages */
426 		__revoke_inmem_pages(inode, &fi->inmem_pages, true, false);
427 	} else {
428 		__revoke_inmem_pages(inode, &revoke_list, false, false);
429 	}
430 
431 	return err;
432 }
433 
434 int commit_inmem_pages(struct inode *inode)
435 {
436 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
437 	struct f2fs_inode_info *fi = F2FS_I(inode);
438 	int err;
439 
440 	f2fs_balance_fs(sbi, true);
441 	f2fs_lock_op(sbi);
442 
443 	set_inode_flag(inode, FI_ATOMIC_COMMIT);
444 
445 	mutex_lock(&fi->inmem_lock);
446 	err = __commit_inmem_pages(inode);
447 
448 	spin_lock(&sbi->inode_lock[ATOMIC_FILE]);
449 	if (!list_empty(&fi->inmem_ilist))
450 		list_del_init(&fi->inmem_ilist);
451 	spin_unlock(&sbi->inode_lock[ATOMIC_FILE]);
452 	mutex_unlock(&fi->inmem_lock);
453 
454 	clear_inode_flag(inode, FI_ATOMIC_COMMIT);
455 
456 	f2fs_unlock_op(sbi);
457 	return err;
458 }
459 
460 /*
461  * This function balances dirty node and dentry pages.
462  * In addition, it controls garbage collection.
463  */
464 void f2fs_balance_fs(struct f2fs_sb_info *sbi, bool need)
465 {
466 #ifdef CONFIG_F2FS_FAULT_INJECTION
467 	if (time_to_inject(sbi, FAULT_CHECKPOINT)) {
468 		f2fs_show_injection_info(FAULT_CHECKPOINT);
469 		f2fs_stop_checkpoint(sbi, false);
470 	}
471 #endif
472 
473 	/* balance_fs_bg is able to be pending */
474 	if (need && excess_cached_nats(sbi))
475 		f2fs_balance_fs_bg(sbi);
476 
477 	/*
478 	 * We should do GC or end up with checkpoint, if there are so many dirty
479 	 * dir/node pages without enough free segments.
480 	 */
481 	if (has_not_enough_free_secs(sbi, 0, 0)) {
482 		mutex_lock(&sbi->gc_mutex);
483 		f2fs_gc(sbi, false, false, NULL_SEGNO);
484 	}
485 }
486 
487 void f2fs_balance_fs_bg(struct f2fs_sb_info *sbi)
488 {
489 	/* try to shrink extent cache when there is no enough memory */
490 	if (!available_free_memory(sbi, EXTENT_CACHE))
491 		f2fs_shrink_extent_tree(sbi, EXTENT_CACHE_SHRINK_NUMBER);
492 
493 	/* check the # of cached NAT entries */
494 	if (!available_free_memory(sbi, NAT_ENTRIES))
495 		try_to_free_nats(sbi, NAT_ENTRY_PER_BLOCK);
496 
497 	if (!available_free_memory(sbi, FREE_NIDS))
498 		try_to_free_nids(sbi, MAX_FREE_NIDS);
499 	else
500 		build_free_nids(sbi, false, false);
501 
502 	if (!is_idle(sbi) && !excess_dirty_nats(sbi))
503 		return;
504 
505 	/* checkpoint is the only way to shrink partial cached entries */
506 	if (!available_free_memory(sbi, NAT_ENTRIES) ||
507 			!available_free_memory(sbi, INO_ENTRIES) ||
508 			excess_prefree_segs(sbi) ||
509 			excess_dirty_nats(sbi) ||
510 			f2fs_time_over(sbi, CP_TIME)) {
511 		if (test_opt(sbi, DATA_FLUSH)) {
512 			struct blk_plug plug;
513 
514 			blk_start_plug(&plug);
515 			sync_dirty_inodes(sbi, FILE_INODE);
516 			blk_finish_plug(&plug);
517 		}
518 		f2fs_sync_fs(sbi->sb, true);
519 		stat_inc_bg_cp_count(sbi->stat_info);
520 	}
521 }
522 
523 static int __submit_flush_wait(struct f2fs_sb_info *sbi,
524 				struct block_device *bdev)
525 {
526 	struct bio *bio = f2fs_bio_alloc(sbi, 0, true);
527 	int ret;
528 
529 	bio->bi_opf = REQ_OP_WRITE | REQ_SYNC | REQ_PREFLUSH;
530 	bio_set_dev(bio, bdev);
531 	ret = submit_bio_wait(bio);
532 	bio_put(bio);
533 
534 	trace_f2fs_issue_flush(bdev, test_opt(sbi, NOBARRIER),
535 				test_opt(sbi, FLUSH_MERGE), ret);
536 	return ret;
537 }
538 
539 static int submit_flush_wait(struct f2fs_sb_info *sbi, nid_t ino)
540 {
541 	int ret = 0;
542 	int i;
543 
544 	if (!sbi->s_ndevs)
545 		return __submit_flush_wait(sbi, sbi->sb->s_bdev);
546 
547 	for (i = 0; i < sbi->s_ndevs; i++) {
548 		if (!is_dirty_device(sbi, ino, i, FLUSH_INO))
549 			continue;
550 		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
551 		if (ret)
552 			break;
553 	}
554 	return ret;
555 }
556 
557 static int issue_flush_thread(void *data)
558 {
559 	struct f2fs_sb_info *sbi = data;
560 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
561 	wait_queue_head_t *q = &fcc->flush_wait_queue;
562 repeat:
563 	if (kthread_should_stop())
564 		return 0;
565 
566 	sb_start_intwrite(sbi->sb);
567 
568 	if (!llist_empty(&fcc->issue_list)) {
569 		struct flush_cmd *cmd, *next;
570 		int ret;
571 
572 		fcc->dispatch_list = llist_del_all(&fcc->issue_list);
573 		fcc->dispatch_list = llist_reverse_order(fcc->dispatch_list);
574 
575 		cmd = llist_entry(fcc->dispatch_list, struct flush_cmd, llnode);
576 
577 		ret = submit_flush_wait(sbi, cmd->ino);
578 		atomic_inc(&fcc->issued_flush);
579 
580 		llist_for_each_entry_safe(cmd, next,
581 					  fcc->dispatch_list, llnode) {
582 			cmd->ret = ret;
583 			complete(&cmd->wait);
584 		}
585 		fcc->dispatch_list = NULL;
586 	}
587 
588 	sb_end_intwrite(sbi->sb);
589 
590 	wait_event_interruptible(*q,
591 		kthread_should_stop() || !llist_empty(&fcc->issue_list));
592 	goto repeat;
593 }
594 
595 int f2fs_issue_flush(struct f2fs_sb_info *sbi, nid_t ino)
596 {
597 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
598 	struct flush_cmd cmd;
599 	int ret;
600 
601 	if (test_opt(sbi, NOBARRIER))
602 		return 0;
603 
604 	if (!test_opt(sbi, FLUSH_MERGE)) {
605 		ret = submit_flush_wait(sbi, ino);
606 		atomic_inc(&fcc->issued_flush);
607 		return ret;
608 	}
609 
610 	if (atomic_inc_return(&fcc->issing_flush) == 1 || sbi->s_ndevs > 1) {
611 		ret = submit_flush_wait(sbi, ino);
612 		atomic_dec(&fcc->issing_flush);
613 
614 		atomic_inc(&fcc->issued_flush);
615 		return ret;
616 	}
617 
618 	cmd.ino = ino;
619 	init_completion(&cmd.wait);
620 
621 	llist_add(&cmd.llnode, &fcc->issue_list);
622 
623 	/* update issue_list before we wake up issue_flush thread */
624 	smp_mb();
625 
626 	if (waitqueue_active(&fcc->flush_wait_queue))
627 		wake_up(&fcc->flush_wait_queue);
628 
629 	if (fcc->f2fs_issue_flush) {
630 		wait_for_completion(&cmd.wait);
631 		atomic_dec(&fcc->issing_flush);
632 	} else {
633 		struct llist_node *list;
634 
635 		list = llist_del_all(&fcc->issue_list);
636 		if (!list) {
637 			wait_for_completion(&cmd.wait);
638 			atomic_dec(&fcc->issing_flush);
639 		} else {
640 			struct flush_cmd *tmp, *next;
641 
642 			ret = submit_flush_wait(sbi, ino);
643 
644 			llist_for_each_entry_safe(tmp, next, list, llnode) {
645 				if (tmp == &cmd) {
646 					cmd.ret = ret;
647 					atomic_dec(&fcc->issing_flush);
648 					continue;
649 				}
650 				tmp->ret = ret;
651 				complete(&tmp->wait);
652 			}
653 		}
654 	}
655 
656 	return cmd.ret;
657 }
658 
659 int create_flush_cmd_control(struct f2fs_sb_info *sbi)
660 {
661 	dev_t dev = sbi->sb->s_bdev->bd_dev;
662 	struct flush_cmd_control *fcc;
663 	int err = 0;
664 
665 	if (SM_I(sbi)->fcc_info) {
666 		fcc = SM_I(sbi)->fcc_info;
667 		if (fcc->f2fs_issue_flush)
668 			return err;
669 		goto init_thread;
670 	}
671 
672 	fcc = f2fs_kzalloc(sbi, sizeof(struct flush_cmd_control), GFP_KERNEL);
673 	if (!fcc)
674 		return -ENOMEM;
675 	atomic_set(&fcc->issued_flush, 0);
676 	atomic_set(&fcc->issing_flush, 0);
677 	init_waitqueue_head(&fcc->flush_wait_queue);
678 	init_llist_head(&fcc->issue_list);
679 	SM_I(sbi)->fcc_info = fcc;
680 	if (!test_opt(sbi, FLUSH_MERGE))
681 		return err;
682 
683 init_thread:
684 	fcc->f2fs_issue_flush = kthread_run(issue_flush_thread, sbi,
685 				"f2fs_flush-%u:%u", MAJOR(dev), MINOR(dev));
686 	if (IS_ERR(fcc->f2fs_issue_flush)) {
687 		err = PTR_ERR(fcc->f2fs_issue_flush);
688 		kfree(fcc);
689 		SM_I(sbi)->fcc_info = NULL;
690 		return err;
691 	}
692 
693 	return err;
694 }
695 
696 void destroy_flush_cmd_control(struct f2fs_sb_info *sbi, bool free)
697 {
698 	struct flush_cmd_control *fcc = SM_I(sbi)->fcc_info;
699 
700 	if (fcc && fcc->f2fs_issue_flush) {
701 		struct task_struct *flush_thread = fcc->f2fs_issue_flush;
702 
703 		fcc->f2fs_issue_flush = NULL;
704 		kthread_stop(flush_thread);
705 	}
706 	if (free) {
707 		kfree(fcc);
708 		SM_I(sbi)->fcc_info = NULL;
709 	}
710 }
711 
712 int f2fs_flush_device_cache(struct f2fs_sb_info *sbi)
713 {
714 	int ret = 0, i;
715 
716 	if (!sbi->s_ndevs)
717 		return 0;
718 
719 	for (i = 1; i < sbi->s_ndevs; i++) {
720 		if (!f2fs_test_bit(i, (char *)&sbi->dirty_device))
721 			continue;
722 		ret = __submit_flush_wait(sbi, FDEV(i).bdev);
723 		if (ret)
724 			break;
725 
726 		spin_lock(&sbi->dev_lock);
727 		f2fs_clear_bit(i, (char *)&sbi->dirty_device);
728 		spin_unlock(&sbi->dev_lock);
729 	}
730 
731 	return ret;
732 }
733 
734 static void __locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
735 		enum dirty_type dirty_type)
736 {
737 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
738 
739 	/* need not be added */
740 	if (IS_CURSEG(sbi, segno))
741 		return;
742 
743 	if (!test_and_set_bit(segno, dirty_i->dirty_segmap[dirty_type]))
744 		dirty_i->nr_dirty[dirty_type]++;
745 
746 	if (dirty_type == DIRTY) {
747 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
748 		enum dirty_type t = sentry->type;
749 
750 		if (unlikely(t >= DIRTY)) {
751 			f2fs_bug_on(sbi, 1);
752 			return;
753 		}
754 		if (!test_and_set_bit(segno, dirty_i->dirty_segmap[t]))
755 			dirty_i->nr_dirty[t]++;
756 	}
757 }
758 
759 static void __remove_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno,
760 		enum dirty_type dirty_type)
761 {
762 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
763 
764 	if (test_and_clear_bit(segno, dirty_i->dirty_segmap[dirty_type]))
765 		dirty_i->nr_dirty[dirty_type]--;
766 
767 	if (dirty_type == DIRTY) {
768 		struct seg_entry *sentry = get_seg_entry(sbi, segno);
769 		enum dirty_type t = sentry->type;
770 
771 		if (test_and_clear_bit(segno, dirty_i->dirty_segmap[t]))
772 			dirty_i->nr_dirty[t]--;
773 
774 		if (get_valid_blocks(sbi, segno, true) == 0)
775 			clear_bit(GET_SEC_FROM_SEG(sbi, segno),
776 						dirty_i->victim_secmap);
777 	}
778 }
779 
780 /*
781  * Should not occur error such as -ENOMEM.
782  * Adding dirty entry into seglist is not critical operation.
783  * If a given segment is one of current working segments, it won't be added.
784  */
785 static void locate_dirty_segment(struct f2fs_sb_info *sbi, unsigned int segno)
786 {
787 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
788 	unsigned short valid_blocks;
789 
790 	if (segno == NULL_SEGNO || IS_CURSEG(sbi, segno))
791 		return;
792 
793 	mutex_lock(&dirty_i->seglist_lock);
794 
795 	valid_blocks = get_valid_blocks(sbi, segno, false);
796 
797 	if (valid_blocks == 0) {
798 		__locate_dirty_segment(sbi, segno, PRE);
799 		__remove_dirty_segment(sbi, segno, DIRTY);
800 	} else if (valid_blocks < sbi->blocks_per_seg) {
801 		__locate_dirty_segment(sbi, segno, DIRTY);
802 	} else {
803 		/* Recovery routine with SSR needs this */
804 		__remove_dirty_segment(sbi, segno, DIRTY);
805 	}
806 
807 	mutex_unlock(&dirty_i->seglist_lock);
808 }
809 
810 static struct discard_cmd *__create_discard_cmd(struct f2fs_sb_info *sbi,
811 		struct block_device *bdev, block_t lstart,
812 		block_t start, block_t len)
813 {
814 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
815 	struct list_head *pend_list;
816 	struct discard_cmd *dc;
817 
818 	f2fs_bug_on(sbi, !len);
819 
820 	pend_list = &dcc->pend_list[plist_idx(len)];
821 
822 	dc = f2fs_kmem_cache_alloc(discard_cmd_slab, GFP_NOFS);
823 	INIT_LIST_HEAD(&dc->list);
824 	dc->bdev = bdev;
825 	dc->lstart = lstart;
826 	dc->start = start;
827 	dc->len = len;
828 	dc->ref = 0;
829 	dc->state = D_PREP;
830 	dc->error = 0;
831 	init_completion(&dc->wait);
832 	list_add_tail(&dc->list, pend_list);
833 	atomic_inc(&dcc->discard_cmd_cnt);
834 	dcc->undiscard_blks += len;
835 
836 	return dc;
837 }
838 
839 static struct discard_cmd *__attach_discard_cmd(struct f2fs_sb_info *sbi,
840 				struct block_device *bdev, block_t lstart,
841 				block_t start, block_t len,
842 				struct rb_node *parent, struct rb_node **p)
843 {
844 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
845 	struct discard_cmd *dc;
846 
847 	dc = __create_discard_cmd(sbi, bdev, lstart, start, len);
848 
849 	rb_link_node(&dc->rb_node, parent, p);
850 	rb_insert_color(&dc->rb_node, &dcc->root);
851 
852 	return dc;
853 }
854 
855 static void __detach_discard_cmd(struct discard_cmd_control *dcc,
856 							struct discard_cmd *dc)
857 {
858 	if (dc->state == D_DONE)
859 		atomic_dec(&dcc->issing_discard);
860 
861 	list_del(&dc->list);
862 	rb_erase(&dc->rb_node, &dcc->root);
863 	dcc->undiscard_blks -= dc->len;
864 
865 	kmem_cache_free(discard_cmd_slab, dc);
866 
867 	atomic_dec(&dcc->discard_cmd_cnt);
868 }
869 
870 static void __remove_discard_cmd(struct f2fs_sb_info *sbi,
871 							struct discard_cmd *dc)
872 {
873 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
874 
875 	trace_f2fs_remove_discard(dc->bdev, dc->start, dc->len);
876 
877 	f2fs_bug_on(sbi, dc->ref);
878 
879 	if (dc->error == -EOPNOTSUPP)
880 		dc->error = 0;
881 
882 	if (dc->error)
883 		f2fs_msg(sbi->sb, KERN_INFO,
884 			"Issue discard(%u, %u, %u) failed, ret: %d",
885 			dc->lstart, dc->start, dc->len, dc->error);
886 	__detach_discard_cmd(dcc, dc);
887 }
888 
889 static void f2fs_submit_discard_endio(struct bio *bio)
890 {
891 	struct discard_cmd *dc = (struct discard_cmd *)bio->bi_private;
892 
893 	dc->error = blk_status_to_errno(bio->bi_status);
894 	dc->state = D_DONE;
895 	complete_all(&dc->wait);
896 	bio_put(bio);
897 }
898 
899 static void __check_sit_bitmap(struct f2fs_sb_info *sbi,
900 				block_t start, block_t end)
901 {
902 #ifdef CONFIG_F2FS_CHECK_FS
903 	struct seg_entry *sentry;
904 	unsigned int segno;
905 	block_t blk = start;
906 	unsigned long offset, size, max_blocks = sbi->blocks_per_seg;
907 	unsigned long *map;
908 
909 	while (blk < end) {
910 		segno = GET_SEGNO(sbi, blk);
911 		sentry = get_seg_entry(sbi, segno);
912 		offset = GET_BLKOFF_FROM_SEG0(sbi, blk);
913 
914 		if (end < START_BLOCK(sbi, segno + 1))
915 			size = GET_BLKOFF_FROM_SEG0(sbi, end);
916 		else
917 			size = max_blocks;
918 		map = (unsigned long *)(sentry->cur_valid_map);
919 		offset = __find_rev_next_bit(map, size, offset);
920 		f2fs_bug_on(sbi, offset != size);
921 		blk = START_BLOCK(sbi, segno + 1);
922 	}
923 #endif
924 }
925 
926 static void __init_discard_policy(struct f2fs_sb_info *sbi,
927 				struct discard_policy *dpolicy,
928 				int discard_type, unsigned int granularity)
929 {
930 	/* common policy */
931 	dpolicy->type = discard_type;
932 	dpolicy->sync = true;
933 	dpolicy->granularity = granularity;
934 
935 	dpolicy->max_requests = DEF_MAX_DISCARD_REQUEST;
936 	dpolicy->io_aware_gran = MAX_PLIST_NUM;
937 
938 	if (discard_type == DPOLICY_BG) {
939 		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
940 		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
941 		dpolicy->io_aware = true;
942 		dpolicy->sync = false;
943 		if (utilization(sbi) > DEF_DISCARD_URGENT_UTIL) {
944 			dpolicy->granularity = 1;
945 			dpolicy->max_interval = DEF_MIN_DISCARD_ISSUE_TIME;
946 		}
947 	} else if (discard_type == DPOLICY_FORCE) {
948 		dpolicy->min_interval = DEF_MIN_DISCARD_ISSUE_TIME;
949 		dpolicy->max_interval = DEF_MAX_DISCARD_ISSUE_TIME;
950 		dpolicy->io_aware = false;
951 	} else if (discard_type == DPOLICY_FSTRIM) {
952 		dpolicy->io_aware = false;
953 	} else if (discard_type == DPOLICY_UMOUNT) {
954 		dpolicy->max_requests = UINT_MAX;
955 		dpolicy->io_aware = false;
956 	}
957 }
958 
959 
960 /* this function is copied from blkdev_issue_discard from block/blk-lib.c */
961 static void __submit_discard_cmd(struct f2fs_sb_info *sbi,
962 						struct discard_policy *dpolicy,
963 						struct discard_cmd *dc)
964 {
965 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
966 	struct list_head *wait_list = (dpolicy->type == DPOLICY_FSTRIM) ?
967 					&(dcc->fstrim_list) : &(dcc->wait_list);
968 	struct bio *bio = NULL;
969 	int flag = dpolicy->sync ? REQ_SYNC : 0;
970 
971 	if (dc->state != D_PREP)
972 		return;
973 
974 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK))
975 		return;
976 
977 	trace_f2fs_issue_discard(dc->bdev, dc->start, dc->len);
978 
979 	dc->error = __blkdev_issue_discard(dc->bdev,
980 				SECTOR_FROM_BLOCK(dc->start),
981 				SECTOR_FROM_BLOCK(dc->len),
982 				GFP_NOFS, 0, &bio);
983 	if (!dc->error) {
984 		/* should keep before submission to avoid D_DONE right away */
985 		dc->state = D_SUBMIT;
986 		atomic_inc(&dcc->issued_discard);
987 		atomic_inc(&dcc->issing_discard);
988 		if (bio) {
989 			bio->bi_private = dc;
990 			bio->bi_end_io = f2fs_submit_discard_endio;
991 			bio->bi_opf |= flag;
992 			submit_bio(bio);
993 			list_move_tail(&dc->list, wait_list);
994 			__check_sit_bitmap(sbi, dc->start, dc->start + dc->len);
995 
996 			f2fs_update_iostat(sbi, FS_DISCARD, 1);
997 		}
998 	} else {
999 		__remove_discard_cmd(sbi, dc);
1000 	}
1001 }
1002 
1003 static struct discard_cmd *__insert_discard_tree(struct f2fs_sb_info *sbi,
1004 				struct block_device *bdev, block_t lstart,
1005 				block_t start, block_t len,
1006 				struct rb_node **insert_p,
1007 				struct rb_node *insert_parent)
1008 {
1009 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1010 	struct rb_node **p;
1011 	struct rb_node *parent = NULL;
1012 	struct discard_cmd *dc = NULL;
1013 
1014 	if (insert_p && insert_parent) {
1015 		parent = insert_parent;
1016 		p = insert_p;
1017 		goto do_insert;
1018 	}
1019 
1020 	p = __lookup_rb_tree_for_insert(sbi, &dcc->root, &parent, lstart);
1021 do_insert:
1022 	dc = __attach_discard_cmd(sbi, bdev, lstart, start, len, parent, p);
1023 	if (!dc)
1024 		return NULL;
1025 
1026 	return dc;
1027 }
1028 
1029 static void __relocate_discard_cmd(struct discard_cmd_control *dcc,
1030 						struct discard_cmd *dc)
1031 {
1032 	list_move_tail(&dc->list, &dcc->pend_list[plist_idx(dc->len)]);
1033 }
1034 
1035 static void __punch_discard_cmd(struct f2fs_sb_info *sbi,
1036 				struct discard_cmd *dc, block_t blkaddr)
1037 {
1038 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1039 	struct discard_info di = dc->di;
1040 	bool modified = false;
1041 
1042 	if (dc->state == D_DONE || dc->len == 1) {
1043 		__remove_discard_cmd(sbi, dc);
1044 		return;
1045 	}
1046 
1047 	dcc->undiscard_blks -= di.len;
1048 
1049 	if (blkaddr > di.lstart) {
1050 		dc->len = blkaddr - dc->lstart;
1051 		dcc->undiscard_blks += dc->len;
1052 		__relocate_discard_cmd(dcc, dc);
1053 		modified = true;
1054 	}
1055 
1056 	if (blkaddr < di.lstart + di.len - 1) {
1057 		if (modified) {
1058 			__insert_discard_tree(sbi, dc->bdev, blkaddr + 1,
1059 					di.start + blkaddr + 1 - di.lstart,
1060 					di.lstart + di.len - 1 - blkaddr,
1061 					NULL, NULL);
1062 		} else {
1063 			dc->lstart++;
1064 			dc->len--;
1065 			dc->start++;
1066 			dcc->undiscard_blks += dc->len;
1067 			__relocate_discard_cmd(dcc, dc);
1068 		}
1069 	}
1070 }
1071 
1072 static void __update_discard_tree_range(struct f2fs_sb_info *sbi,
1073 				struct block_device *bdev, block_t lstart,
1074 				block_t start, block_t len)
1075 {
1076 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1077 	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
1078 	struct discard_cmd *dc;
1079 	struct discard_info di = {0};
1080 	struct rb_node **insert_p = NULL, *insert_parent = NULL;
1081 	block_t end = lstart + len;
1082 
1083 	mutex_lock(&dcc->cmd_lock);
1084 
1085 	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
1086 					NULL, lstart,
1087 					(struct rb_entry **)&prev_dc,
1088 					(struct rb_entry **)&next_dc,
1089 					&insert_p, &insert_parent, true);
1090 	if (dc)
1091 		prev_dc = dc;
1092 
1093 	if (!prev_dc) {
1094 		di.lstart = lstart;
1095 		di.len = next_dc ? next_dc->lstart - lstart : len;
1096 		di.len = min(di.len, len);
1097 		di.start = start;
1098 	}
1099 
1100 	while (1) {
1101 		struct rb_node *node;
1102 		bool merged = false;
1103 		struct discard_cmd *tdc = NULL;
1104 
1105 		if (prev_dc) {
1106 			di.lstart = prev_dc->lstart + prev_dc->len;
1107 			if (di.lstart < lstart)
1108 				di.lstart = lstart;
1109 			if (di.lstart >= end)
1110 				break;
1111 
1112 			if (!next_dc || next_dc->lstart > end)
1113 				di.len = end - di.lstart;
1114 			else
1115 				di.len = next_dc->lstart - di.lstart;
1116 			di.start = start + di.lstart - lstart;
1117 		}
1118 
1119 		if (!di.len)
1120 			goto next;
1121 
1122 		if (prev_dc && prev_dc->state == D_PREP &&
1123 			prev_dc->bdev == bdev &&
1124 			__is_discard_back_mergeable(&di, &prev_dc->di)) {
1125 			prev_dc->di.len += di.len;
1126 			dcc->undiscard_blks += di.len;
1127 			__relocate_discard_cmd(dcc, prev_dc);
1128 			di = prev_dc->di;
1129 			tdc = prev_dc;
1130 			merged = true;
1131 		}
1132 
1133 		if (next_dc && next_dc->state == D_PREP &&
1134 			next_dc->bdev == bdev &&
1135 			__is_discard_front_mergeable(&di, &next_dc->di)) {
1136 			next_dc->di.lstart = di.lstart;
1137 			next_dc->di.len += di.len;
1138 			next_dc->di.start = di.start;
1139 			dcc->undiscard_blks += di.len;
1140 			__relocate_discard_cmd(dcc, next_dc);
1141 			if (tdc)
1142 				__remove_discard_cmd(sbi, tdc);
1143 			merged = true;
1144 		}
1145 
1146 		if (!merged) {
1147 			__insert_discard_tree(sbi, bdev, di.lstart, di.start,
1148 							di.len, NULL, NULL);
1149 		}
1150  next:
1151 		prev_dc = next_dc;
1152 		if (!prev_dc)
1153 			break;
1154 
1155 		node = rb_next(&prev_dc->rb_node);
1156 		next_dc = rb_entry_safe(node, struct discard_cmd, rb_node);
1157 	}
1158 
1159 	mutex_unlock(&dcc->cmd_lock);
1160 }
1161 
1162 static int __queue_discard_cmd(struct f2fs_sb_info *sbi,
1163 		struct block_device *bdev, block_t blkstart, block_t blklen)
1164 {
1165 	block_t lblkstart = blkstart;
1166 
1167 	trace_f2fs_queue_discard(bdev, blkstart, blklen);
1168 
1169 	if (sbi->s_ndevs) {
1170 		int devi = f2fs_target_device_index(sbi, blkstart);
1171 
1172 		blkstart -= FDEV(devi).start_blk;
1173 	}
1174 	__update_discard_tree_range(sbi, bdev, lblkstart, blkstart, blklen);
1175 	return 0;
1176 }
1177 
1178 static int __issue_discard_cmd(struct f2fs_sb_info *sbi,
1179 					struct discard_policy *dpolicy)
1180 {
1181 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1182 	struct list_head *pend_list;
1183 	struct discard_cmd *dc, *tmp;
1184 	struct blk_plug plug;
1185 	int i, iter = 0, issued = 0;
1186 	bool io_interrupted = false;
1187 
1188 	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
1189 		if (i + 1 < dpolicy->granularity)
1190 			break;
1191 		pend_list = &dcc->pend_list[i];
1192 
1193 		mutex_lock(&dcc->cmd_lock);
1194 		if (list_empty(pend_list))
1195 			goto next;
1196 		f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
1197 		blk_start_plug(&plug);
1198 		list_for_each_entry_safe(dc, tmp, pend_list, list) {
1199 			f2fs_bug_on(sbi, dc->state != D_PREP);
1200 
1201 			if (dpolicy->io_aware && i < dpolicy->io_aware_gran &&
1202 								!is_idle(sbi)) {
1203 				io_interrupted = true;
1204 				goto skip;
1205 			}
1206 
1207 			__submit_discard_cmd(sbi, dpolicy, dc);
1208 			issued++;
1209 skip:
1210 			if (++iter >= dpolicy->max_requests)
1211 				break;
1212 		}
1213 		blk_finish_plug(&plug);
1214 next:
1215 		mutex_unlock(&dcc->cmd_lock);
1216 
1217 		if (iter >= dpolicy->max_requests)
1218 			break;
1219 	}
1220 
1221 	if (!issued && io_interrupted)
1222 		issued = -1;
1223 
1224 	return issued;
1225 }
1226 
1227 static bool __drop_discard_cmd(struct f2fs_sb_info *sbi)
1228 {
1229 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1230 	struct list_head *pend_list;
1231 	struct discard_cmd *dc, *tmp;
1232 	int i;
1233 	bool dropped = false;
1234 
1235 	mutex_lock(&dcc->cmd_lock);
1236 	for (i = MAX_PLIST_NUM - 1; i >= 0; i--) {
1237 		pend_list = &dcc->pend_list[i];
1238 		list_for_each_entry_safe(dc, tmp, pend_list, list) {
1239 			f2fs_bug_on(sbi, dc->state != D_PREP);
1240 			__remove_discard_cmd(sbi, dc);
1241 			dropped = true;
1242 		}
1243 	}
1244 	mutex_unlock(&dcc->cmd_lock);
1245 
1246 	return dropped;
1247 }
1248 
1249 void drop_discard_cmd(struct f2fs_sb_info *sbi)
1250 {
1251 	__drop_discard_cmd(sbi);
1252 }
1253 
1254 static unsigned int __wait_one_discard_bio(struct f2fs_sb_info *sbi,
1255 							struct discard_cmd *dc)
1256 {
1257 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1258 	unsigned int len = 0;
1259 
1260 	wait_for_completion_io(&dc->wait);
1261 	mutex_lock(&dcc->cmd_lock);
1262 	f2fs_bug_on(sbi, dc->state != D_DONE);
1263 	dc->ref--;
1264 	if (!dc->ref) {
1265 		if (!dc->error)
1266 			len = dc->len;
1267 		__remove_discard_cmd(sbi, dc);
1268 	}
1269 	mutex_unlock(&dcc->cmd_lock);
1270 
1271 	return len;
1272 }
1273 
1274 static unsigned int __wait_discard_cmd_range(struct f2fs_sb_info *sbi,
1275 						struct discard_policy *dpolicy,
1276 						block_t start, block_t end)
1277 {
1278 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1279 	struct list_head *wait_list = (dpolicy->type == DPOLICY_FSTRIM) ?
1280 					&(dcc->fstrim_list) : &(dcc->wait_list);
1281 	struct discard_cmd *dc, *tmp;
1282 	bool need_wait;
1283 	unsigned int trimmed = 0;
1284 
1285 next:
1286 	need_wait = false;
1287 
1288 	mutex_lock(&dcc->cmd_lock);
1289 	list_for_each_entry_safe(dc, tmp, wait_list, list) {
1290 		if (dc->lstart + dc->len <= start || end <= dc->lstart)
1291 			continue;
1292 		if (dc->len < dpolicy->granularity)
1293 			continue;
1294 		if (dc->state == D_DONE && !dc->ref) {
1295 			wait_for_completion_io(&dc->wait);
1296 			if (!dc->error)
1297 				trimmed += dc->len;
1298 			__remove_discard_cmd(sbi, dc);
1299 		} else {
1300 			dc->ref++;
1301 			need_wait = true;
1302 			break;
1303 		}
1304 	}
1305 	mutex_unlock(&dcc->cmd_lock);
1306 
1307 	if (need_wait) {
1308 		trimmed += __wait_one_discard_bio(sbi, dc);
1309 		goto next;
1310 	}
1311 
1312 	return trimmed;
1313 }
1314 
1315 static void __wait_all_discard_cmd(struct f2fs_sb_info *sbi,
1316 						struct discard_policy *dpolicy)
1317 {
1318 	struct discard_policy dp;
1319 
1320 	if (dpolicy) {
1321 		__wait_discard_cmd_range(sbi, dpolicy, 0, UINT_MAX);
1322 		return;
1323 	}
1324 
1325 	/* wait all */
1326 	__init_discard_policy(sbi, &dp, DPOLICY_FSTRIM, 1);
1327 	__wait_discard_cmd_range(sbi, &dp, 0, UINT_MAX);
1328 	__init_discard_policy(sbi, &dp, DPOLICY_UMOUNT, 1);
1329 	__wait_discard_cmd_range(sbi, &dp, 0, UINT_MAX);
1330 }
1331 
1332 /* This should be covered by global mutex, &sit_i->sentry_lock */
1333 static void f2fs_wait_discard_bio(struct f2fs_sb_info *sbi, block_t blkaddr)
1334 {
1335 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1336 	struct discard_cmd *dc;
1337 	bool need_wait = false;
1338 
1339 	mutex_lock(&dcc->cmd_lock);
1340 	dc = (struct discard_cmd *)__lookup_rb_tree(&dcc->root, NULL, blkaddr);
1341 	if (dc) {
1342 		if (dc->state == D_PREP) {
1343 			__punch_discard_cmd(sbi, dc, blkaddr);
1344 		} else {
1345 			dc->ref++;
1346 			need_wait = true;
1347 		}
1348 	}
1349 	mutex_unlock(&dcc->cmd_lock);
1350 
1351 	if (need_wait)
1352 		__wait_one_discard_bio(sbi, dc);
1353 }
1354 
1355 void stop_discard_thread(struct f2fs_sb_info *sbi)
1356 {
1357 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1358 
1359 	if (dcc && dcc->f2fs_issue_discard) {
1360 		struct task_struct *discard_thread = dcc->f2fs_issue_discard;
1361 
1362 		dcc->f2fs_issue_discard = NULL;
1363 		kthread_stop(discard_thread);
1364 	}
1365 }
1366 
1367 /* This comes from f2fs_put_super */
1368 bool f2fs_wait_discard_bios(struct f2fs_sb_info *sbi)
1369 {
1370 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1371 	struct discard_policy dpolicy;
1372 	bool dropped;
1373 
1374 	__init_discard_policy(sbi, &dpolicy, DPOLICY_UMOUNT,
1375 					dcc->discard_granularity);
1376 	__issue_discard_cmd(sbi, &dpolicy);
1377 	dropped = __drop_discard_cmd(sbi);
1378 
1379 	/* just to make sure there is no pending discard commands */
1380 	__wait_all_discard_cmd(sbi, NULL);
1381 	return dropped;
1382 }
1383 
1384 static int issue_discard_thread(void *data)
1385 {
1386 	struct f2fs_sb_info *sbi = data;
1387 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1388 	wait_queue_head_t *q = &dcc->discard_wait_queue;
1389 	struct discard_policy dpolicy;
1390 	unsigned int wait_ms = DEF_MIN_DISCARD_ISSUE_TIME;
1391 	int issued;
1392 
1393 	set_freezable();
1394 
1395 	do {
1396 		__init_discard_policy(sbi, &dpolicy, DPOLICY_BG,
1397 					dcc->discard_granularity);
1398 
1399 		wait_event_interruptible_timeout(*q,
1400 				kthread_should_stop() || freezing(current) ||
1401 				dcc->discard_wake,
1402 				msecs_to_jiffies(wait_ms));
1403 		if (try_to_freeze())
1404 			continue;
1405 		if (f2fs_readonly(sbi->sb))
1406 			continue;
1407 		if (kthread_should_stop())
1408 			return 0;
1409 		if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
1410 			wait_ms = dpolicy.max_interval;
1411 			continue;
1412 		}
1413 
1414 		if (dcc->discard_wake)
1415 			dcc->discard_wake = 0;
1416 
1417 		if (sbi->gc_mode == GC_URGENT)
1418 			__init_discard_policy(sbi, &dpolicy, DPOLICY_FORCE, 1);
1419 
1420 		sb_start_intwrite(sbi->sb);
1421 
1422 		issued = __issue_discard_cmd(sbi, &dpolicy);
1423 		if (issued) {
1424 			__wait_all_discard_cmd(sbi, &dpolicy);
1425 			wait_ms = dpolicy.min_interval;
1426 		} else {
1427 			wait_ms = dpolicy.max_interval;
1428 		}
1429 
1430 		sb_end_intwrite(sbi->sb);
1431 
1432 	} while (!kthread_should_stop());
1433 	return 0;
1434 }
1435 
1436 #ifdef CONFIG_BLK_DEV_ZONED
1437 static int __f2fs_issue_discard_zone(struct f2fs_sb_info *sbi,
1438 		struct block_device *bdev, block_t blkstart, block_t blklen)
1439 {
1440 	sector_t sector, nr_sects;
1441 	block_t lblkstart = blkstart;
1442 	int devi = 0;
1443 
1444 	if (sbi->s_ndevs) {
1445 		devi = f2fs_target_device_index(sbi, blkstart);
1446 		blkstart -= FDEV(devi).start_blk;
1447 	}
1448 
1449 	/*
1450 	 * We need to know the type of the zone: for conventional zones,
1451 	 * use regular discard if the drive supports it. For sequential
1452 	 * zones, reset the zone write pointer.
1453 	 */
1454 	switch (get_blkz_type(sbi, bdev, blkstart)) {
1455 
1456 	case BLK_ZONE_TYPE_CONVENTIONAL:
1457 		if (!blk_queue_discard(bdev_get_queue(bdev)))
1458 			return 0;
1459 		return __queue_discard_cmd(sbi, bdev, lblkstart, blklen);
1460 	case BLK_ZONE_TYPE_SEQWRITE_REQ:
1461 	case BLK_ZONE_TYPE_SEQWRITE_PREF:
1462 		sector = SECTOR_FROM_BLOCK(blkstart);
1463 		nr_sects = SECTOR_FROM_BLOCK(blklen);
1464 
1465 		if (sector & (bdev_zone_sectors(bdev) - 1) ||
1466 				nr_sects != bdev_zone_sectors(bdev)) {
1467 			f2fs_msg(sbi->sb, KERN_INFO,
1468 				"(%d) %s: Unaligned discard attempted (block %x + %x)",
1469 				devi, sbi->s_ndevs ? FDEV(devi).path: "",
1470 				blkstart, blklen);
1471 			return -EIO;
1472 		}
1473 		trace_f2fs_issue_reset_zone(bdev, blkstart);
1474 		return blkdev_reset_zones(bdev, sector,
1475 					  nr_sects, GFP_NOFS);
1476 	default:
1477 		/* Unknown zone type: broken device ? */
1478 		return -EIO;
1479 	}
1480 }
1481 #endif
1482 
1483 static int __issue_discard_async(struct f2fs_sb_info *sbi,
1484 		struct block_device *bdev, block_t blkstart, block_t blklen)
1485 {
1486 #ifdef CONFIG_BLK_DEV_ZONED
1487 	if (f2fs_sb_has_blkzoned(sbi->sb) &&
1488 				bdev_zoned_model(bdev) != BLK_ZONED_NONE)
1489 		return __f2fs_issue_discard_zone(sbi, bdev, blkstart, blklen);
1490 #endif
1491 	return __queue_discard_cmd(sbi, bdev, blkstart, blklen);
1492 }
1493 
1494 static int f2fs_issue_discard(struct f2fs_sb_info *sbi,
1495 				block_t blkstart, block_t blklen)
1496 {
1497 	sector_t start = blkstart, len = 0;
1498 	struct block_device *bdev;
1499 	struct seg_entry *se;
1500 	unsigned int offset;
1501 	block_t i;
1502 	int err = 0;
1503 
1504 	bdev = f2fs_target_device(sbi, blkstart, NULL);
1505 
1506 	for (i = blkstart; i < blkstart + blklen; i++, len++) {
1507 		if (i != start) {
1508 			struct block_device *bdev2 =
1509 				f2fs_target_device(sbi, i, NULL);
1510 
1511 			if (bdev2 != bdev) {
1512 				err = __issue_discard_async(sbi, bdev,
1513 						start, len);
1514 				if (err)
1515 					return err;
1516 				bdev = bdev2;
1517 				start = i;
1518 				len = 0;
1519 			}
1520 		}
1521 
1522 		se = get_seg_entry(sbi, GET_SEGNO(sbi, i));
1523 		offset = GET_BLKOFF_FROM_SEG0(sbi, i);
1524 
1525 		if (!f2fs_test_and_set_bit(offset, se->discard_map))
1526 			sbi->discard_blks--;
1527 	}
1528 
1529 	if (len)
1530 		err = __issue_discard_async(sbi, bdev, start, len);
1531 	return err;
1532 }
1533 
1534 static bool add_discard_addrs(struct f2fs_sb_info *sbi, struct cp_control *cpc,
1535 							bool check_only)
1536 {
1537 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
1538 	int max_blocks = sbi->blocks_per_seg;
1539 	struct seg_entry *se = get_seg_entry(sbi, cpc->trim_start);
1540 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
1541 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
1542 	unsigned long *discard_map = (unsigned long *)se->discard_map;
1543 	unsigned long *dmap = SIT_I(sbi)->tmp_map;
1544 	unsigned int start = 0, end = -1;
1545 	bool force = (cpc->reason & CP_DISCARD);
1546 	struct discard_entry *de = NULL;
1547 	struct list_head *head = &SM_I(sbi)->dcc_info->entry_list;
1548 	int i;
1549 
1550 	if (se->valid_blocks == max_blocks || !f2fs_discard_en(sbi))
1551 		return false;
1552 
1553 	if (!force) {
1554 		if (!test_opt(sbi, DISCARD) || !se->valid_blocks ||
1555 			SM_I(sbi)->dcc_info->nr_discards >=
1556 				SM_I(sbi)->dcc_info->max_discards)
1557 			return false;
1558 	}
1559 
1560 	/* SIT_VBLOCK_MAP_SIZE should be multiple of sizeof(unsigned long) */
1561 	for (i = 0; i < entries; i++)
1562 		dmap[i] = force ? ~ckpt_map[i] & ~discard_map[i] :
1563 				(cur_map[i] ^ ckpt_map[i]) & ckpt_map[i];
1564 
1565 	while (force || SM_I(sbi)->dcc_info->nr_discards <=
1566 				SM_I(sbi)->dcc_info->max_discards) {
1567 		start = __find_rev_next_bit(dmap, max_blocks, end + 1);
1568 		if (start >= max_blocks)
1569 			break;
1570 
1571 		end = __find_rev_next_zero_bit(dmap, max_blocks, start + 1);
1572 		if (force && start && end != max_blocks
1573 					&& (end - start) < cpc->trim_minlen)
1574 			continue;
1575 
1576 		if (check_only)
1577 			return true;
1578 
1579 		if (!de) {
1580 			de = f2fs_kmem_cache_alloc(discard_entry_slab,
1581 								GFP_F2FS_ZERO);
1582 			de->start_blkaddr = START_BLOCK(sbi, cpc->trim_start);
1583 			list_add_tail(&de->list, head);
1584 		}
1585 
1586 		for (i = start; i < end; i++)
1587 			__set_bit_le(i, (void *)de->discard_map);
1588 
1589 		SM_I(sbi)->dcc_info->nr_discards += end - start;
1590 	}
1591 	return false;
1592 }
1593 
1594 static void release_discard_addr(struct discard_entry *entry)
1595 {
1596 	list_del(&entry->list);
1597 	kmem_cache_free(discard_entry_slab, entry);
1598 }
1599 
1600 void release_discard_addrs(struct f2fs_sb_info *sbi)
1601 {
1602 	struct list_head *head = &(SM_I(sbi)->dcc_info->entry_list);
1603 	struct discard_entry *entry, *this;
1604 
1605 	/* drop caches */
1606 	list_for_each_entry_safe(entry, this, head, list)
1607 		release_discard_addr(entry);
1608 }
1609 
1610 /*
1611  * Should call clear_prefree_segments after checkpoint is done.
1612  */
1613 static void set_prefree_as_free_segments(struct f2fs_sb_info *sbi)
1614 {
1615 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1616 	unsigned int segno;
1617 
1618 	mutex_lock(&dirty_i->seglist_lock);
1619 	for_each_set_bit(segno, dirty_i->dirty_segmap[PRE], MAIN_SEGS(sbi))
1620 		__set_test_and_free(sbi, segno);
1621 	mutex_unlock(&dirty_i->seglist_lock);
1622 }
1623 
1624 void clear_prefree_segments(struct f2fs_sb_info *sbi, struct cp_control *cpc)
1625 {
1626 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1627 	struct list_head *head = &dcc->entry_list;
1628 	struct discard_entry *entry, *this;
1629 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
1630 	unsigned long *prefree_map = dirty_i->dirty_segmap[PRE];
1631 	unsigned int start = 0, end = -1;
1632 	unsigned int secno, start_segno;
1633 	bool force = (cpc->reason & CP_DISCARD);
1634 
1635 	mutex_lock(&dirty_i->seglist_lock);
1636 
1637 	while (1) {
1638 		int i;
1639 		start = find_next_bit(prefree_map, MAIN_SEGS(sbi), end + 1);
1640 		if (start >= MAIN_SEGS(sbi))
1641 			break;
1642 		end = find_next_zero_bit(prefree_map, MAIN_SEGS(sbi),
1643 								start + 1);
1644 
1645 		for (i = start; i < end; i++)
1646 			clear_bit(i, prefree_map);
1647 
1648 		dirty_i->nr_dirty[PRE] -= end - start;
1649 
1650 		if (!test_opt(sbi, DISCARD))
1651 			continue;
1652 
1653 		if (force && start >= cpc->trim_start &&
1654 					(end - 1) <= cpc->trim_end)
1655 				continue;
1656 
1657 		if (!test_opt(sbi, LFS) || sbi->segs_per_sec == 1) {
1658 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start),
1659 				(end - start) << sbi->log_blocks_per_seg);
1660 			continue;
1661 		}
1662 next:
1663 		secno = GET_SEC_FROM_SEG(sbi, start);
1664 		start_segno = GET_SEG_FROM_SEC(sbi, secno);
1665 		if (!IS_CURSEC(sbi, secno) &&
1666 			!get_valid_blocks(sbi, start, true))
1667 			f2fs_issue_discard(sbi, START_BLOCK(sbi, start_segno),
1668 				sbi->segs_per_sec << sbi->log_blocks_per_seg);
1669 
1670 		start = start_segno + sbi->segs_per_sec;
1671 		if (start < end)
1672 			goto next;
1673 		else
1674 			end = start - 1;
1675 	}
1676 	mutex_unlock(&dirty_i->seglist_lock);
1677 
1678 	/* send small discards */
1679 	list_for_each_entry_safe(entry, this, head, list) {
1680 		unsigned int cur_pos = 0, next_pos, len, total_len = 0;
1681 		bool is_valid = test_bit_le(0, entry->discard_map);
1682 
1683 find_next:
1684 		if (is_valid) {
1685 			next_pos = find_next_zero_bit_le(entry->discard_map,
1686 					sbi->blocks_per_seg, cur_pos);
1687 			len = next_pos - cur_pos;
1688 
1689 			if (f2fs_sb_has_blkzoned(sbi->sb) ||
1690 			    (force && len < cpc->trim_minlen))
1691 				goto skip;
1692 
1693 			f2fs_issue_discard(sbi, entry->start_blkaddr + cur_pos,
1694 									len);
1695 			total_len += len;
1696 		} else {
1697 			next_pos = find_next_bit_le(entry->discard_map,
1698 					sbi->blocks_per_seg, cur_pos);
1699 		}
1700 skip:
1701 		cur_pos = next_pos;
1702 		is_valid = !is_valid;
1703 
1704 		if (cur_pos < sbi->blocks_per_seg)
1705 			goto find_next;
1706 
1707 		release_discard_addr(entry);
1708 		dcc->nr_discards -= total_len;
1709 	}
1710 
1711 	wake_up_discard_thread(sbi, false);
1712 }
1713 
1714 static int create_discard_cmd_control(struct f2fs_sb_info *sbi)
1715 {
1716 	dev_t dev = sbi->sb->s_bdev->bd_dev;
1717 	struct discard_cmd_control *dcc;
1718 	int err = 0, i;
1719 
1720 	if (SM_I(sbi)->dcc_info) {
1721 		dcc = SM_I(sbi)->dcc_info;
1722 		goto init_thread;
1723 	}
1724 
1725 	dcc = f2fs_kzalloc(sbi, sizeof(struct discard_cmd_control), GFP_KERNEL);
1726 	if (!dcc)
1727 		return -ENOMEM;
1728 
1729 	dcc->discard_granularity = DEFAULT_DISCARD_GRANULARITY;
1730 	INIT_LIST_HEAD(&dcc->entry_list);
1731 	for (i = 0; i < MAX_PLIST_NUM; i++)
1732 		INIT_LIST_HEAD(&dcc->pend_list[i]);
1733 	INIT_LIST_HEAD(&dcc->wait_list);
1734 	INIT_LIST_HEAD(&dcc->fstrim_list);
1735 	mutex_init(&dcc->cmd_lock);
1736 	atomic_set(&dcc->issued_discard, 0);
1737 	atomic_set(&dcc->issing_discard, 0);
1738 	atomic_set(&dcc->discard_cmd_cnt, 0);
1739 	dcc->nr_discards = 0;
1740 	dcc->max_discards = MAIN_SEGS(sbi) << sbi->log_blocks_per_seg;
1741 	dcc->undiscard_blks = 0;
1742 	dcc->root = RB_ROOT;
1743 
1744 	init_waitqueue_head(&dcc->discard_wait_queue);
1745 	SM_I(sbi)->dcc_info = dcc;
1746 init_thread:
1747 	dcc->f2fs_issue_discard = kthread_run(issue_discard_thread, sbi,
1748 				"f2fs_discard-%u:%u", MAJOR(dev), MINOR(dev));
1749 	if (IS_ERR(dcc->f2fs_issue_discard)) {
1750 		err = PTR_ERR(dcc->f2fs_issue_discard);
1751 		kfree(dcc);
1752 		SM_I(sbi)->dcc_info = NULL;
1753 		return err;
1754 	}
1755 
1756 	return err;
1757 }
1758 
1759 static void destroy_discard_cmd_control(struct f2fs_sb_info *sbi)
1760 {
1761 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
1762 
1763 	if (!dcc)
1764 		return;
1765 
1766 	stop_discard_thread(sbi);
1767 
1768 	kfree(dcc);
1769 	SM_I(sbi)->dcc_info = NULL;
1770 }
1771 
1772 static bool __mark_sit_entry_dirty(struct f2fs_sb_info *sbi, unsigned int segno)
1773 {
1774 	struct sit_info *sit_i = SIT_I(sbi);
1775 
1776 	if (!__test_and_set_bit(segno, sit_i->dirty_sentries_bitmap)) {
1777 		sit_i->dirty_sentries++;
1778 		return false;
1779 	}
1780 
1781 	return true;
1782 }
1783 
1784 static void __set_sit_entry_type(struct f2fs_sb_info *sbi, int type,
1785 					unsigned int segno, int modified)
1786 {
1787 	struct seg_entry *se = get_seg_entry(sbi, segno);
1788 	se->type = type;
1789 	if (modified)
1790 		__mark_sit_entry_dirty(sbi, segno);
1791 }
1792 
1793 static void update_sit_entry(struct f2fs_sb_info *sbi, block_t blkaddr, int del)
1794 {
1795 	struct seg_entry *se;
1796 	unsigned int segno, offset;
1797 	long int new_vblocks;
1798 	bool exist;
1799 #ifdef CONFIG_F2FS_CHECK_FS
1800 	bool mir_exist;
1801 #endif
1802 
1803 	segno = GET_SEGNO(sbi, blkaddr);
1804 
1805 	se = get_seg_entry(sbi, segno);
1806 	new_vblocks = se->valid_blocks + del;
1807 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1808 
1809 	f2fs_bug_on(sbi, (new_vblocks >> (sizeof(unsigned short) << 3) ||
1810 				(new_vblocks > sbi->blocks_per_seg)));
1811 
1812 	se->valid_blocks = new_vblocks;
1813 	se->mtime = get_mtime(sbi);
1814 	SIT_I(sbi)->max_mtime = se->mtime;
1815 
1816 	/* Update valid block bitmap */
1817 	if (del > 0) {
1818 		exist = f2fs_test_and_set_bit(offset, se->cur_valid_map);
1819 #ifdef CONFIG_F2FS_CHECK_FS
1820 		mir_exist = f2fs_test_and_set_bit(offset,
1821 						se->cur_valid_map_mir);
1822 		if (unlikely(exist != mir_exist)) {
1823 			f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent error "
1824 				"when setting bitmap, blk:%u, old bit:%d",
1825 				blkaddr, exist);
1826 			f2fs_bug_on(sbi, 1);
1827 		}
1828 #endif
1829 		if (unlikely(exist)) {
1830 			f2fs_msg(sbi->sb, KERN_ERR,
1831 				"Bitmap was wrongly set, blk:%u", blkaddr);
1832 			f2fs_bug_on(sbi, 1);
1833 			se->valid_blocks--;
1834 			del = 0;
1835 		}
1836 
1837 		if (f2fs_discard_en(sbi) &&
1838 			!f2fs_test_and_set_bit(offset, se->discard_map))
1839 			sbi->discard_blks--;
1840 
1841 		/* don't overwrite by SSR to keep node chain */
1842 		if (IS_NODESEG(se->type)) {
1843 			if (!f2fs_test_and_set_bit(offset, se->ckpt_valid_map))
1844 				se->ckpt_valid_blocks++;
1845 		}
1846 	} else {
1847 		exist = f2fs_test_and_clear_bit(offset, se->cur_valid_map);
1848 #ifdef CONFIG_F2FS_CHECK_FS
1849 		mir_exist = f2fs_test_and_clear_bit(offset,
1850 						se->cur_valid_map_mir);
1851 		if (unlikely(exist != mir_exist)) {
1852 			f2fs_msg(sbi->sb, KERN_ERR, "Inconsistent error "
1853 				"when clearing bitmap, blk:%u, old bit:%d",
1854 				blkaddr, exist);
1855 			f2fs_bug_on(sbi, 1);
1856 		}
1857 #endif
1858 		if (unlikely(!exist)) {
1859 			f2fs_msg(sbi->sb, KERN_ERR,
1860 				"Bitmap was wrongly cleared, blk:%u", blkaddr);
1861 			f2fs_bug_on(sbi, 1);
1862 			se->valid_blocks++;
1863 			del = 0;
1864 		}
1865 
1866 		if (f2fs_discard_en(sbi) &&
1867 			f2fs_test_and_clear_bit(offset, se->discard_map))
1868 			sbi->discard_blks++;
1869 	}
1870 	if (!f2fs_test_bit(offset, se->ckpt_valid_map))
1871 		se->ckpt_valid_blocks += del;
1872 
1873 	__mark_sit_entry_dirty(sbi, segno);
1874 
1875 	/* update total number of valid blocks to be written in ckpt area */
1876 	SIT_I(sbi)->written_valid_blocks += del;
1877 
1878 	if (sbi->segs_per_sec > 1)
1879 		get_sec_entry(sbi, segno)->valid_blocks += del;
1880 }
1881 
1882 void invalidate_blocks(struct f2fs_sb_info *sbi, block_t addr)
1883 {
1884 	unsigned int segno = GET_SEGNO(sbi, addr);
1885 	struct sit_info *sit_i = SIT_I(sbi);
1886 
1887 	f2fs_bug_on(sbi, addr == NULL_ADDR);
1888 	if (addr == NEW_ADDR)
1889 		return;
1890 
1891 	/* add it into sit main buffer */
1892 	down_write(&sit_i->sentry_lock);
1893 
1894 	update_sit_entry(sbi, addr, -1);
1895 
1896 	/* add it into dirty seglist */
1897 	locate_dirty_segment(sbi, segno);
1898 
1899 	up_write(&sit_i->sentry_lock);
1900 }
1901 
1902 bool is_checkpointed_data(struct f2fs_sb_info *sbi, block_t blkaddr)
1903 {
1904 	struct sit_info *sit_i = SIT_I(sbi);
1905 	unsigned int segno, offset;
1906 	struct seg_entry *se;
1907 	bool is_cp = false;
1908 
1909 	if (!is_valid_blkaddr(blkaddr))
1910 		return true;
1911 
1912 	down_read(&sit_i->sentry_lock);
1913 
1914 	segno = GET_SEGNO(sbi, blkaddr);
1915 	se = get_seg_entry(sbi, segno);
1916 	offset = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
1917 
1918 	if (f2fs_test_bit(offset, se->ckpt_valid_map))
1919 		is_cp = true;
1920 
1921 	up_read(&sit_i->sentry_lock);
1922 
1923 	return is_cp;
1924 }
1925 
1926 /*
1927  * This function should be resided under the curseg_mutex lock
1928  */
1929 static void __add_sum_entry(struct f2fs_sb_info *sbi, int type,
1930 					struct f2fs_summary *sum)
1931 {
1932 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1933 	void *addr = curseg->sum_blk;
1934 	addr += curseg->next_blkoff * sizeof(struct f2fs_summary);
1935 	memcpy(addr, sum, sizeof(struct f2fs_summary));
1936 }
1937 
1938 /*
1939  * Calculate the number of current summary pages for writing
1940  */
1941 int npages_for_summary_flush(struct f2fs_sb_info *sbi, bool for_ra)
1942 {
1943 	int valid_sum_count = 0;
1944 	int i, sum_in_page;
1945 
1946 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
1947 		if (sbi->ckpt->alloc_type[i] == SSR)
1948 			valid_sum_count += sbi->blocks_per_seg;
1949 		else {
1950 			if (for_ra)
1951 				valid_sum_count += le16_to_cpu(
1952 					F2FS_CKPT(sbi)->cur_data_blkoff[i]);
1953 			else
1954 				valid_sum_count += curseg_blkoff(sbi, i);
1955 		}
1956 	}
1957 
1958 	sum_in_page = (PAGE_SIZE - 2 * SUM_JOURNAL_SIZE -
1959 			SUM_FOOTER_SIZE) / SUMMARY_SIZE;
1960 	if (valid_sum_count <= sum_in_page)
1961 		return 1;
1962 	else if ((valid_sum_count - sum_in_page) <=
1963 		(PAGE_SIZE - SUM_FOOTER_SIZE) / SUMMARY_SIZE)
1964 		return 2;
1965 	return 3;
1966 }
1967 
1968 /*
1969  * Caller should put this summary page
1970  */
1971 struct page *get_sum_page(struct f2fs_sb_info *sbi, unsigned int segno)
1972 {
1973 	return get_meta_page(sbi, GET_SUM_BLOCK(sbi, segno));
1974 }
1975 
1976 void update_meta_page(struct f2fs_sb_info *sbi, void *src, block_t blk_addr)
1977 {
1978 	struct page *page = grab_meta_page(sbi, blk_addr);
1979 
1980 	memcpy(page_address(page), src, PAGE_SIZE);
1981 	set_page_dirty(page);
1982 	f2fs_put_page(page, 1);
1983 }
1984 
1985 static void write_sum_page(struct f2fs_sb_info *sbi,
1986 			struct f2fs_summary_block *sum_blk, block_t blk_addr)
1987 {
1988 	update_meta_page(sbi, (void *)sum_blk, blk_addr);
1989 }
1990 
1991 static void write_current_sum_page(struct f2fs_sb_info *sbi,
1992 						int type, block_t blk_addr)
1993 {
1994 	struct curseg_info *curseg = CURSEG_I(sbi, type);
1995 	struct page *page = grab_meta_page(sbi, blk_addr);
1996 	struct f2fs_summary_block *src = curseg->sum_blk;
1997 	struct f2fs_summary_block *dst;
1998 
1999 	dst = (struct f2fs_summary_block *)page_address(page);
2000 	memset(dst, 0, PAGE_SIZE);
2001 
2002 	mutex_lock(&curseg->curseg_mutex);
2003 
2004 	down_read(&curseg->journal_rwsem);
2005 	memcpy(&dst->journal, curseg->journal, SUM_JOURNAL_SIZE);
2006 	up_read(&curseg->journal_rwsem);
2007 
2008 	memcpy(dst->entries, src->entries, SUM_ENTRY_SIZE);
2009 	memcpy(&dst->footer, &src->footer, SUM_FOOTER_SIZE);
2010 
2011 	mutex_unlock(&curseg->curseg_mutex);
2012 
2013 	set_page_dirty(page);
2014 	f2fs_put_page(page, 1);
2015 }
2016 
2017 static int is_next_segment_free(struct f2fs_sb_info *sbi, int type)
2018 {
2019 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2020 	unsigned int segno = curseg->segno + 1;
2021 	struct free_segmap_info *free_i = FREE_I(sbi);
2022 
2023 	if (segno < MAIN_SEGS(sbi) && segno % sbi->segs_per_sec)
2024 		return !test_bit(segno, free_i->free_segmap);
2025 	return 0;
2026 }
2027 
2028 /*
2029  * Find a new segment from the free segments bitmap to right order
2030  * This function should be returned with success, otherwise BUG
2031  */
2032 static void get_new_segment(struct f2fs_sb_info *sbi,
2033 			unsigned int *newseg, bool new_sec, int dir)
2034 {
2035 	struct free_segmap_info *free_i = FREE_I(sbi);
2036 	unsigned int segno, secno, zoneno;
2037 	unsigned int total_zones = MAIN_SECS(sbi) / sbi->secs_per_zone;
2038 	unsigned int hint = GET_SEC_FROM_SEG(sbi, *newseg);
2039 	unsigned int old_zoneno = GET_ZONE_FROM_SEG(sbi, *newseg);
2040 	unsigned int left_start = hint;
2041 	bool init = true;
2042 	int go_left = 0;
2043 	int i;
2044 
2045 	spin_lock(&free_i->segmap_lock);
2046 
2047 	if (!new_sec && ((*newseg + 1) % sbi->segs_per_sec)) {
2048 		segno = find_next_zero_bit(free_i->free_segmap,
2049 			GET_SEG_FROM_SEC(sbi, hint + 1), *newseg + 1);
2050 		if (segno < GET_SEG_FROM_SEC(sbi, hint + 1))
2051 			goto got_it;
2052 	}
2053 find_other_zone:
2054 	secno = find_next_zero_bit(free_i->free_secmap, MAIN_SECS(sbi), hint);
2055 	if (secno >= MAIN_SECS(sbi)) {
2056 		if (dir == ALLOC_RIGHT) {
2057 			secno = find_next_zero_bit(free_i->free_secmap,
2058 							MAIN_SECS(sbi), 0);
2059 			f2fs_bug_on(sbi, secno >= MAIN_SECS(sbi));
2060 		} else {
2061 			go_left = 1;
2062 			left_start = hint - 1;
2063 		}
2064 	}
2065 	if (go_left == 0)
2066 		goto skip_left;
2067 
2068 	while (test_bit(left_start, free_i->free_secmap)) {
2069 		if (left_start > 0) {
2070 			left_start--;
2071 			continue;
2072 		}
2073 		left_start = find_next_zero_bit(free_i->free_secmap,
2074 							MAIN_SECS(sbi), 0);
2075 		f2fs_bug_on(sbi, left_start >= MAIN_SECS(sbi));
2076 		break;
2077 	}
2078 	secno = left_start;
2079 skip_left:
2080 	segno = GET_SEG_FROM_SEC(sbi, secno);
2081 	zoneno = GET_ZONE_FROM_SEC(sbi, secno);
2082 
2083 	/* give up on finding another zone */
2084 	if (!init)
2085 		goto got_it;
2086 	if (sbi->secs_per_zone == 1)
2087 		goto got_it;
2088 	if (zoneno == old_zoneno)
2089 		goto got_it;
2090 	if (dir == ALLOC_LEFT) {
2091 		if (!go_left && zoneno + 1 >= total_zones)
2092 			goto got_it;
2093 		if (go_left && zoneno == 0)
2094 			goto got_it;
2095 	}
2096 	for (i = 0; i < NR_CURSEG_TYPE; i++)
2097 		if (CURSEG_I(sbi, i)->zone == zoneno)
2098 			break;
2099 
2100 	if (i < NR_CURSEG_TYPE) {
2101 		/* zone is in user, try another */
2102 		if (go_left)
2103 			hint = zoneno * sbi->secs_per_zone - 1;
2104 		else if (zoneno + 1 >= total_zones)
2105 			hint = 0;
2106 		else
2107 			hint = (zoneno + 1) * sbi->secs_per_zone;
2108 		init = false;
2109 		goto find_other_zone;
2110 	}
2111 got_it:
2112 	/* set it as dirty segment in free segmap */
2113 	f2fs_bug_on(sbi, test_bit(segno, free_i->free_segmap));
2114 	__set_inuse(sbi, segno);
2115 	*newseg = segno;
2116 	spin_unlock(&free_i->segmap_lock);
2117 }
2118 
2119 static void reset_curseg(struct f2fs_sb_info *sbi, int type, int modified)
2120 {
2121 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2122 	struct summary_footer *sum_footer;
2123 
2124 	curseg->segno = curseg->next_segno;
2125 	curseg->zone = GET_ZONE_FROM_SEG(sbi, curseg->segno);
2126 	curseg->next_blkoff = 0;
2127 	curseg->next_segno = NULL_SEGNO;
2128 
2129 	sum_footer = &(curseg->sum_blk->footer);
2130 	memset(sum_footer, 0, sizeof(struct summary_footer));
2131 	if (IS_DATASEG(type))
2132 		SET_SUM_TYPE(sum_footer, SUM_TYPE_DATA);
2133 	if (IS_NODESEG(type))
2134 		SET_SUM_TYPE(sum_footer, SUM_TYPE_NODE);
2135 	__set_sit_entry_type(sbi, type, curseg->segno, modified);
2136 }
2137 
2138 static unsigned int __get_next_segno(struct f2fs_sb_info *sbi, int type)
2139 {
2140 	/* if segs_per_sec is large than 1, we need to keep original policy. */
2141 	if (sbi->segs_per_sec != 1)
2142 		return CURSEG_I(sbi, type)->segno;
2143 
2144 	if (test_opt(sbi, NOHEAP) &&
2145 		(type == CURSEG_HOT_DATA || IS_NODESEG(type)))
2146 		return 0;
2147 
2148 	if (SIT_I(sbi)->last_victim[ALLOC_NEXT])
2149 		return SIT_I(sbi)->last_victim[ALLOC_NEXT];
2150 
2151 	/* find segments from 0 to reuse freed segments */
2152 	if (F2FS_OPTION(sbi).alloc_mode == ALLOC_MODE_REUSE)
2153 		return 0;
2154 
2155 	return CURSEG_I(sbi, type)->segno;
2156 }
2157 
2158 /*
2159  * Allocate a current working segment.
2160  * This function always allocates a free segment in LFS manner.
2161  */
2162 static void new_curseg(struct f2fs_sb_info *sbi, int type, bool new_sec)
2163 {
2164 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2165 	unsigned int segno = curseg->segno;
2166 	int dir = ALLOC_LEFT;
2167 
2168 	write_sum_page(sbi, curseg->sum_blk,
2169 				GET_SUM_BLOCK(sbi, segno));
2170 	if (type == CURSEG_WARM_DATA || type == CURSEG_COLD_DATA)
2171 		dir = ALLOC_RIGHT;
2172 
2173 	if (test_opt(sbi, NOHEAP))
2174 		dir = ALLOC_RIGHT;
2175 
2176 	segno = __get_next_segno(sbi, type);
2177 	get_new_segment(sbi, &segno, new_sec, dir);
2178 	curseg->next_segno = segno;
2179 	reset_curseg(sbi, type, 1);
2180 	curseg->alloc_type = LFS;
2181 }
2182 
2183 static void __next_free_blkoff(struct f2fs_sb_info *sbi,
2184 			struct curseg_info *seg, block_t start)
2185 {
2186 	struct seg_entry *se = get_seg_entry(sbi, seg->segno);
2187 	int entries = SIT_VBLOCK_MAP_SIZE / sizeof(unsigned long);
2188 	unsigned long *target_map = SIT_I(sbi)->tmp_map;
2189 	unsigned long *ckpt_map = (unsigned long *)se->ckpt_valid_map;
2190 	unsigned long *cur_map = (unsigned long *)se->cur_valid_map;
2191 	int i, pos;
2192 
2193 	for (i = 0; i < entries; i++)
2194 		target_map[i] = ckpt_map[i] | cur_map[i];
2195 
2196 	pos = __find_rev_next_zero_bit(target_map, sbi->blocks_per_seg, start);
2197 
2198 	seg->next_blkoff = pos;
2199 }
2200 
2201 /*
2202  * If a segment is written by LFS manner, next block offset is just obtained
2203  * by increasing the current block offset. However, if a segment is written by
2204  * SSR manner, next block offset obtained by calling __next_free_blkoff
2205  */
2206 static void __refresh_next_blkoff(struct f2fs_sb_info *sbi,
2207 				struct curseg_info *seg)
2208 {
2209 	if (seg->alloc_type == SSR)
2210 		__next_free_blkoff(sbi, seg, seg->next_blkoff + 1);
2211 	else
2212 		seg->next_blkoff++;
2213 }
2214 
2215 /*
2216  * This function always allocates a used segment(from dirty seglist) by SSR
2217  * manner, so it should recover the existing segment information of valid blocks
2218  */
2219 static void change_curseg(struct f2fs_sb_info *sbi, int type)
2220 {
2221 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
2222 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2223 	unsigned int new_segno = curseg->next_segno;
2224 	struct f2fs_summary_block *sum_node;
2225 	struct page *sum_page;
2226 
2227 	write_sum_page(sbi, curseg->sum_blk,
2228 				GET_SUM_BLOCK(sbi, curseg->segno));
2229 	__set_test_and_inuse(sbi, new_segno);
2230 
2231 	mutex_lock(&dirty_i->seglist_lock);
2232 	__remove_dirty_segment(sbi, new_segno, PRE);
2233 	__remove_dirty_segment(sbi, new_segno, DIRTY);
2234 	mutex_unlock(&dirty_i->seglist_lock);
2235 
2236 	reset_curseg(sbi, type, 1);
2237 	curseg->alloc_type = SSR;
2238 	__next_free_blkoff(sbi, curseg, 0);
2239 
2240 	sum_page = get_sum_page(sbi, new_segno);
2241 	sum_node = (struct f2fs_summary_block *)page_address(sum_page);
2242 	memcpy(curseg->sum_blk, sum_node, SUM_ENTRY_SIZE);
2243 	f2fs_put_page(sum_page, 1);
2244 }
2245 
2246 static int get_ssr_segment(struct f2fs_sb_info *sbi, int type)
2247 {
2248 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2249 	const struct victim_selection *v_ops = DIRTY_I(sbi)->v_ops;
2250 	unsigned segno = NULL_SEGNO;
2251 	int i, cnt;
2252 	bool reversed = false;
2253 
2254 	/* need_SSR() already forces to do this */
2255 	if (v_ops->get_victim(sbi, &segno, BG_GC, type, SSR)) {
2256 		curseg->next_segno = segno;
2257 		return 1;
2258 	}
2259 
2260 	/* For node segments, let's do SSR more intensively */
2261 	if (IS_NODESEG(type)) {
2262 		if (type >= CURSEG_WARM_NODE) {
2263 			reversed = true;
2264 			i = CURSEG_COLD_NODE;
2265 		} else {
2266 			i = CURSEG_HOT_NODE;
2267 		}
2268 		cnt = NR_CURSEG_NODE_TYPE;
2269 	} else {
2270 		if (type >= CURSEG_WARM_DATA) {
2271 			reversed = true;
2272 			i = CURSEG_COLD_DATA;
2273 		} else {
2274 			i = CURSEG_HOT_DATA;
2275 		}
2276 		cnt = NR_CURSEG_DATA_TYPE;
2277 	}
2278 
2279 	for (; cnt-- > 0; reversed ? i-- : i++) {
2280 		if (i == type)
2281 			continue;
2282 		if (v_ops->get_victim(sbi, &segno, BG_GC, i, SSR)) {
2283 			curseg->next_segno = segno;
2284 			return 1;
2285 		}
2286 	}
2287 	return 0;
2288 }
2289 
2290 /*
2291  * flush out current segment and replace it with new segment
2292  * This function should be returned with success, otherwise BUG
2293  */
2294 static void allocate_segment_by_default(struct f2fs_sb_info *sbi,
2295 						int type, bool force)
2296 {
2297 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2298 
2299 	if (force)
2300 		new_curseg(sbi, type, true);
2301 	else if (!is_set_ckpt_flags(sbi, CP_CRC_RECOVERY_FLAG) &&
2302 					type == CURSEG_WARM_NODE)
2303 		new_curseg(sbi, type, false);
2304 	else if (curseg->alloc_type == LFS && is_next_segment_free(sbi, type))
2305 		new_curseg(sbi, type, false);
2306 	else if (need_SSR(sbi) && get_ssr_segment(sbi, type))
2307 		change_curseg(sbi, type);
2308 	else
2309 		new_curseg(sbi, type, false);
2310 
2311 	stat_inc_seg_type(sbi, curseg);
2312 }
2313 
2314 void allocate_new_segments(struct f2fs_sb_info *sbi)
2315 {
2316 	struct curseg_info *curseg;
2317 	unsigned int old_segno;
2318 	int i;
2319 
2320 	down_write(&SIT_I(sbi)->sentry_lock);
2321 
2322 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
2323 		curseg = CURSEG_I(sbi, i);
2324 		old_segno = curseg->segno;
2325 		SIT_I(sbi)->s_ops->allocate_segment(sbi, i, true);
2326 		locate_dirty_segment(sbi, old_segno);
2327 	}
2328 
2329 	up_write(&SIT_I(sbi)->sentry_lock);
2330 }
2331 
2332 static const struct segment_allocation default_salloc_ops = {
2333 	.allocate_segment = allocate_segment_by_default,
2334 };
2335 
2336 bool exist_trim_candidates(struct f2fs_sb_info *sbi, struct cp_control *cpc)
2337 {
2338 	__u64 trim_start = cpc->trim_start;
2339 	bool has_candidate = false;
2340 
2341 	down_write(&SIT_I(sbi)->sentry_lock);
2342 	for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++) {
2343 		if (add_discard_addrs(sbi, cpc, true)) {
2344 			has_candidate = true;
2345 			break;
2346 		}
2347 	}
2348 	up_write(&SIT_I(sbi)->sentry_lock);
2349 
2350 	cpc->trim_start = trim_start;
2351 	return has_candidate;
2352 }
2353 
2354 static void __issue_discard_cmd_range(struct f2fs_sb_info *sbi,
2355 					struct discard_policy *dpolicy,
2356 					unsigned int start, unsigned int end)
2357 {
2358 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
2359 	struct discard_cmd *prev_dc = NULL, *next_dc = NULL;
2360 	struct rb_node **insert_p = NULL, *insert_parent = NULL;
2361 	struct discard_cmd *dc;
2362 	struct blk_plug plug;
2363 	int issued;
2364 
2365 next:
2366 	issued = 0;
2367 
2368 	mutex_lock(&dcc->cmd_lock);
2369 	f2fs_bug_on(sbi, !__check_rb_tree_consistence(sbi, &dcc->root));
2370 
2371 	dc = (struct discard_cmd *)__lookup_rb_tree_ret(&dcc->root,
2372 					NULL, start,
2373 					(struct rb_entry **)&prev_dc,
2374 					(struct rb_entry **)&next_dc,
2375 					&insert_p, &insert_parent, true);
2376 	if (!dc)
2377 		dc = next_dc;
2378 
2379 	blk_start_plug(&plug);
2380 
2381 	while (dc && dc->lstart <= end) {
2382 		struct rb_node *node;
2383 
2384 		if (dc->len < dpolicy->granularity)
2385 			goto skip;
2386 
2387 		if (dc->state != D_PREP) {
2388 			list_move_tail(&dc->list, &dcc->fstrim_list);
2389 			goto skip;
2390 		}
2391 
2392 		__submit_discard_cmd(sbi, dpolicy, dc);
2393 
2394 		if (++issued >= dpolicy->max_requests) {
2395 			start = dc->lstart + dc->len;
2396 
2397 			blk_finish_plug(&plug);
2398 			mutex_unlock(&dcc->cmd_lock);
2399 			__wait_all_discard_cmd(sbi, NULL);
2400 			congestion_wait(BLK_RW_ASYNC, HZ/50);
2401 			goto next;
2402 		}
2403 skip:
2404 		node = rb_next(&dc->rb_node);
2405 		dc = rb_entry_safe(node, struct discard_cmd, rb_node);
2406 
2407 		if (fatal_signal_pending(current))
2408 			break;
2409 	}
2410 
2411 	blk_finish_plug(&plug);
2412 	mutex_unlock(&dcc->cmd_lock);
2413 }
2414 
2415 int f2fs_trim_fs(struct f2fs_sb_info *sbi, struct fstrim_range *range)
2416 {
2417 	__u64 start = F2FS_BYTES_TO_BLK(range->start);
2418 	__u64 end = start + F2FS_BYTES_TO_BLK(range->len) - 1;
2419 	unsigned int start_segno, end_segno;
2420 	block_t start_block, end_block;
2421 	struct cp_control cpc;
2422 	struct discard_policy dpolicy;
2423 	unsigned long long trimmed = 0;
2424 	int err = 0;
2425 
2426 	if (start >= MAX_BLKADDR(sbi) || range->len < sbi->blocksize)
2427 		return -EINVAL;
2428 
2429 	if (end <= MAIN_BLKADDR(sbi))
2430 		return -EINVAL;
2431 
2432 	if (is_sbi_flag_set(sbi, SBI_NEED_FSCK)) {
2433 		f2fs_msg(sbi->sb, KERN_WARNING,
2434 			"Found FS corruption, run fsck to fix.");
2435 		return -EIO;
2436 	}
2437 
2438 	/* start/end segment number in main_area */
2439 	start_segno = (start <= MAIN_BLKADDR(sbi)) ? 0 : GET_SEGNO(sbi, start);
2440 	end_segno = (end >= MAX_BLKADDR(sbi)) ? MAIN_SEGS(sbi) - 1 :
2441 						GET_SEGNO(sbi, end);
2442 
2443 	cpc.reason = CP_DISCARD;
2444 	cpc.trim_minlen = max_t(__u64, 1, F2FS_BYTES_TO_BLK(range->minlen));
2445 	cpc.trim_start = start_segno;
2446 	cpc.trim_end = end_segno;
2447 
2448 	if (sbi->discard_blks == 0)
2449 		goto out;
2450 
2451 	mutex_lock(&sbi->gc_mutex);
2452 	err = write_checkpoint(sbi, &cpc);
2453 	mutex_unlock(&sbi->gc_mutex);
2454 	if (err)
2455 		goto out;
2456 
2457 	start_block = START_BLOCK(sbi, start_segno);
2458 	end_block = START_BLOCK(sbi, end_segno + 1);
2459 
2460 	__init_discard_policy(sbi, &dpolicy, DPOLICY_FSTRIM, cpc.trim_minlen);
2461 	__issue_discard_cmd_range(sbi, &dpolicy, start_block, end_block);
2462 
2463 	/*
2464 	 * We filed discard candidates, but actually we don't need to wait for
2465 	 * all of them, since they'll be issued in idle time along with runtime
2466 	 * discard option. User configuration looks like using runtime discard
2467 	 * or periodic fstrim instead of it.
2468 	 */
2469 	if (!test_opt(sbi, DISCARD)) {
2470 		trimmed = __wait_discard_cmd_range(sbi, &dpolicy,
2471 					start_block, end_block);
2472 		range->len = F2FS_BLK_TO_BYTES(trimmed);
2473 	}
2474 out:
2475 	return err;
2476 }
2477 
2478 static bool __has_curseg_space(struct f2fs_sb_info *sbi, int type)
2479 {
2480 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2481 	if (curseg->next_blkoff < sbi->blocks_per_seg)
2482 		return true;
2483 	return false;
2484 }
2485 
2486 int rw_hint_to_seg_type(enum rw_hint hint)
2487 {
2488 	switch (hint) {
2489 	case WRITE_LIFE_SHORT:
2490 		return CURSEG_HOT_DATA;
2491 	case WRITE_LIFE_EXTREME:
2492 		return CURSEG_COLD_DATA;
2493 	default:
2494 		return CURSEG_WARM_DATA;
2495 	}
2496 }
2497 
2498 /* This returns write hints for each segment type. This hints will be
2499  * passed down to block layer. There are mapping tables which depend on
2500  * the mount option 'whint_mode'.
2501  *
2502  * 1) whint_mode=off. F2FS only passes down WRITE_LIFE_NOT_SET.
2503  *
2504  * 2) whint_mode=user-based. F2FS tries to pass down hints given by users.
2505  *
2506  * User                  F2FS                     Block
2507  * ----                  ----                     -----
2508  *                       META                     WRITE_LIFE_NOT_SET
2509  *                       HOT_NODE                 "
2510  *                       WARM_NODE                "
2511  *                       COLD_NODE                "
2512  * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
2513  * extension list        "                        "
2514  *
2515  * -- buffered io
2516  * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
2517  * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
2518  * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
2519  * WRITE_LIFE_NONE       "                        "
2520  * WRITE_LIFE_MEDIUM     "                        "
2521  * WRITE_LIFE_LONG       "                        "
2522  *
2523  * -- direct io
2524  * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
2525  * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
2526  * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
2527  * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
2528  * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
2529  * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
2530  *
2531  * 3) whint_mode=fs-based. F2FS passes down hints with its policy.
2532  *
2533  * User                  F2FS                     Block
2534  * ----                  ----                     -----
2535  *                       META                     WRITE_LIFE_MEDIUM;
2536  *                       HOT_NODE                 WRITE_LIFE_NOT_SET
2537  *                       WARM_NODE                "
2538  *                       COLD_NODE                WRITE_LIFE_NONE
2539  * ioctl(COLD)           COLD_DATA                WRITE_LIFE_EXTREME
2540  * extension list        "                        "
2541  *
2542  * -- buffered io
2543  * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
2544  * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
2545  * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_LONG
2546  * WRITE_LIFE_NONE       "                        "
2547  * WRITE_LIFE_MEDIUM     "                        "
2548  * WRITE_LIFE_LONG       "                        "
2549  *
2550  * -- direct io
2551  * WRITE_LIFE_EXTREME    COLD_DATA                WRITE_LIFE_EXTREME
2552  * WRITE_LIFE_SHORT      HOT_DATA                 WRITE_LIFE_SHORT
2553  * WRITE_LIFE_NOT_SET    WARM_DATA                WRITE_LIFE_NOT_SET
2554  * WRITE_LIFE_NONE       "                        WRITE_LIFE_NONE
2555  * WRITE_LIFE_MEDIUM     "                        WRITE_LIFE_MEDIUM
2556  * WRITE_LIFE_LONG       "                        WRITE_LIFE_LONG
2557  */
2558 
2559 enum rw_hint io_type_to_rw_hint(struct f2fs_sb_info *sbi,
2560 				enum page_type type, enum temp_type temp)
2561 {
2562 	if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_USER) {
2563 		if (type == DATA) {
2564 			if (temp == WARM)
2565 				return WRITE_LIFE_NOT_SET;
2566 			else if (temp == HOT)
2567 				return WRITE_LIFE_SHORT;
2568 			else if (temp == COLD)
2569 				return WRITE_LIFE_EXTREME;
2570 		} else {
2571 			return WRITE_LIFE_NOT_SET;
2572 		}
2573 	} else if (F2FS_OPTION(sbi).whint_mode == WHINT_MODE_FS) {
2574 		if (type == DATA) {
2575 			if (temp == WARM)
2576 				return WRITE_LIFE_LONG;
2577 			else if (temp == HOT)
2578 				return WRITE_LIFE_SHORT;
2579 			else if (temp == COLD)
2580 				return WRITE_LIFE_EXTREME;
2581 		} else if (type == NODE) {
2582 			if (temp == WARM || temp == HOT)
2583 				return WRITE_LIFE_NOT_SET;
2584 			else if (temp == COLD)
2585 				return WRITE_LIFE_NONE;
2586 		} else if (type == META) {
2587 			return WRITE_LIFE_MEDIUM;
2588 		}
2589 	}
2590 	return WRITE_LIFE_NOT_SET;
2591 }
2592 
2593 static int __get_segment_type_2(struct f2fs_io_info *fio)
2594 {
2595 	if (fio->type == DATA)
2596 		return CURSEG_HOT_DATA;
2597 	else
2598 		return CURSEG_HOT_NODE;
2599 }
2600 
2601 static int __get_segment_type_4(struct f2fs_io_info *fio)
2602 {
2603 	if (fio->type == DATA) {
2604 		struct inode *inode = fio->page->mapping->host;
2605 
2606 		if (S_ISDIR(inode->i_mode))
2607 			return CURSEG_HOT_DATA;
2608 		else
2609 			return CURSEG_COLD_DATA;
2610 	} else {
2611 		if (IS_DNODE(fio->page) && is_cold_node(fio->page))
2612 			return CURSEG_WARM_NODE;
2613 		else
2614 			return CURSEG_COLD_NODE;
2615 	}
2616 }
2617 
2618 static int __get_segment_type_6(struct f2fs_io_info *fio)
2619 {
2620 	if (fio->type == DATA) {
2621 		struct inode *inode = fio->page->mapping->host;
2622 
2623 		if (is_cold_data(fio->page) || file_is_cold(inode))
2624 			return CURSEG_COLD_DATA;
2625 		if (file_is_hot(inode) ||
2626 				is_inode_flag_set(inode, FI_HOT_DATA) ||
2627 				is_inode_flag_set(inode, FI_ATOMIC_FILE) ||
2628 				is_inode_flag_set(inode, FI_VOLATILE_FILE))
2629 			return CURSEG_HOT_DATA;
2630 		return rw_hint_to_seg_type(inode->i_write_hint);
2631 	} else {
2632 		if (IS_DNODE(fio->page))
2633 			return is_cold_node(fio->page) ? CURSEG_WARM_NODE :
2634 						CURSEG_HOT_NODE;
2635 		return CURSEG_COLD_NODE;
2636 	}
2637 }
2638 
2639 static int __get_segment_type(struct f2fs_io_info *fio)
2640 {
2641 	int type = 0;
2642 
2643 	switch (F2FS_OPTION(fio->sbi).active_logs) {
2644 	case 2:
2645 		type = __get_segment_type_2(fio);
2646 		break;
2647 	case 4:
2648 		type = __get_segment_type_4(fio);
2649 		break;
2650 	case 6:
2651 		type = __get_segment_type_6(fio);
2652 		break;
2653 	default:
2654 		f2fs_bug_on(fio->sbi, true);
2655 	}
2656 
2657 	if (IS_HOT(type))
2658 		fio->temp = HOT;
2659 	else if (IS_WARM(type))
2660 		fio->temp = WARM;
2661 	else
2662 		fio->temp = COLD;
2663 	return type;
2664 }
2665 
2666 void allocate_data_block(struct f2fs_sb_info *sbi, struct page *page,
2667 		block_t old_blkaddr, block_t *new_blkaddr,
2668 		struct f2fs_summary *sum, int type,
2669 		struct f2fs_io_info *fio, bool add_list)
2670 {
2671 	struct sit_info *sit_i = SIT_I(sbi);
2672 	struct curseg_info *curseg = CURSEG_I(sbi, type);
2673 
2674 	down_read(&SM_I(sbi)->curseg_lock);
2675 
2676 	mutex_lock(&curseg->curseg_mutex);
2677 	down_write(&sit_i->sentry_lock);
2678 
2679 	*new_blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
2680 
2681 	f2fs_wait_discard_bio(sbi, *new_blkaddr);
2682 
2683 	/*
2684 	 * __add_sum_entry should be resided under the curseg_mutex
2685 	 * because, this function updates a summary entry in the
2686 	 * current summary block.
2687 	 */
2688 	__add_sum_entry(sbi, type, sum);
2689 
2690 	__refresh_next_blkoff(sbi, curseg);
2691 
2692 	stat_inc_block_count(sbi, curseg);
2693 
2694 	/*
2695 	 * SIT information should be updated before segment allocation,
2696 	 * since SSR needs latest valid block information.
2697 	 */
2698 	update_sit_entry(sbi, *new_blkaddr, 1);
2699 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
2700 		update_sit_entry(sbi, old_blkaddr, -1);
2701 
2702 	if (!__has_curseg_space(sbi, type))
2703 		sit_i->s_ops->allocate_segment(sbi, type, false);
2704 
2705 	/*
2706 	 * segment dirty status should be updated after segment allocation,
2707 	 * so we just need to update status only one time after previous
2708 	 * segment being closed.
2709 	 */
2710 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
2711 	locate_dirty_segment(sbi, GET_SEGNO(sbi, *new_blkaddr));
2712 
2713 	up_write(&sit_i->sentry_lock);
2714 
2715 	if (page && IS_NODESEG(type)) {
2716 		fill_node_footer_blkaddr(page, NEXT_FREE_BLKADDR(sbi, curseg));
2717 
2718 		f2fs_inode_chksum_set(sbi, page);
2719 	}
2720 
2721 	if (add_list) {
2722 		struct f2fs_bio_info *io;
2723 
2724 		INIT_LIST_HEAD(&fio->list);
2725 		fio->in_list = true;
2726 		io = sbi->write_io[fio->type] + fio->temp;
2727 		spin_lock(&io->io_lock);
2728 		list_add_tail(&fio->list, &io->io_list);
2729 		spin_unlock(&io->io_lock);
2730 	}
2731 
2732 	mutex_unlock(&curseg->curseg_mutex);
2733 
2734 	up_read(&SM_I(sbi)->curseg_lock);
2735 }
2736 
2737 static void update_device_state(struct f2fs_io_info *fio)
2738 {
2739 	struct f2fs_sb_info *sbi = fio->sbi;
2740 	unsigned int devidx;
2741 
2742 	if (!sbi->s_ndevs)
2743 		return;
2744 
2745 	devidx = f2fs_target_device_index(sbi, fio->new_blkaddr);
2746 
2747 	/* update device state for fsync */
2748 	set_dirty_device(sbi, fio->ino, devidx, FLUSH_INO);
2749 
2750 	/* update device state for checkpoint */
2751 	if (!f2fs_test_bit(devidx, (char *)&sbi->dirty_device)) {
2752 		spin_lock(&sbi->dev_lock);
2753 		f2fs_set_bit(devidx, (char *)&sbi->dirty_device);
2754 		spin_unlock(&sbi->dev_lock);
2755 	}
2756 }
2757 
2758 static void do_write_page(struct f2fs_summary *sum, struct f2fs_io_info *fio)
2759 {
2760 	int type = __get_segment_type(fio);
2761 	int err;
2762 	bool keep_order = (test_opt(fio->sbi, LFS) && type == CURSEG_COLD_DATA);
2763 
2764 	if (keep_order)
2765 		down_read(&fio->sbi->io_order_lock);
2766 reallocate:
2767 	allocate_data_block(fio->sbi, fio->page, fio->old_blkaddr,
2768 			&fio->new_blkaddr, sum, type, fio, true);
2769 
2770 	/* writeout dirty page into bdev */
2771 	err = f2fs_submit_page_write(fio);
2772 	if (err == -EAGAIN) {
2773 		fio->old_blkaddr = fio->new_blkaddr;
2774 		goto reallocate;
2775 	} else if (!err) {
2776 		update_device_state(fio);
2777 	}
2778 	if (keep_order)
2779 		up_read(&fio->sbi->io_order_lock);
2780 }
2781 
2782 void write_meta_page(struct f2fs_sb_info *sbi, struct page *page,
2783 					enum iostat_type io_type)
2784 {
2785 	struct f2fs_io_info fio = {
2786 		.sbi = sbi,
2787 		.type = META,
2788 		.temp = HOT,
2789 		.op = REQ_OP_WRITE,
2790 		.op_flags = REQ_SYNC | REQ_META | REQ_PRIO,
2791 		.old_blkaddr = page->index,
2792 		.new_blkaddr = page->index,
2793 		.page = page,
2794 		.encrypted_page = NULL,
2795 		.in_list = false,
2796 	};
2797 
2798 	if (unlikely(page->index >= MAIN_BLKADDR(sbi)))
2799 		fio.op_flags &= ~REQ_META;
2800 
2801 	set_page_writeback(page);
2802 	ClearPageError(page);
2803 	f2fs_submit_page_write(&fio);
2804 
2805 	f2fs_update_iostat(sbi, io_type, F2FS_BLKSIZE);
2806 }
2807 
2808 void write_node_page(unsigned int nid, struct f2fs_io_info *fio)
2809 {
2810 	struct f2fs_summary sum;
2811 
2812 	set_summary(&sum, nid, 0, 0);
2813 	do_write_page(&sum, fio);
2814 
2815 	f2fs_update_iostat(fio->sbi, fio->io_type, F2FS_BLKSIZE);
2816 }
2817 
2818 void write_data_page(struct dnode_of_data *dn, struct f2fs_io_info *fio)
2819 {
2820 	struct f2fs_sb_info *sbi = fio->sbi;
2821 	struct f2fs_summary sum;
2822 	struct node_info ni;
2823 
2824 	f2fs_bug_on(sbi, dn->data_blkaddr == NULL_ADDR);
2825 	get_node_info(sbi, dn->nid, &ni);
2826 	set_summary(&sum, dn->nid, dn->ofs_in_node, ni.version);
2827 	do_write_page(&sum, fio);
2828 	f2fs_update_data_blkaddr(dn, fio->new_blkaddr);
2829 
2830 	f2fs_update_iostat(sbi, fio->io_type, F2FS_BLKSIZE);
2831 }
2832 
2833 int rewrite_data_page(struct f2fs_io_info *fio)
2834 {
2835 	int err;
2836 	struct f2fs_sb_info *sbi = fio->sbi;
2837 
2838 	fio->new_blkaddr = fio->old_blkaddr;
2839 	/* i/o temperature is needed for passing down write hints */
2840 	__get_segment_type(fio);
2841 
2842 	f2fs_bug_on(sbi, !IS_DATASEG(get_seg_entry(sbi,
2843 			GET_SEGNO(sbi, fio->new_blkaddr))->type));
2844 
2845 	stat_inc_inplace_blocks(fio->sbi);
2846 
2847 	err = f2fs_submit_page_bio(fio);
2848 	if (!err)
2849 		update_device_state(fio);
2850 
2851 	f2fs_update_iostat(fio->sbi, fio->io_type, F2FS_BLKSIZE);
2852 
2853 	return err;
2854 }
2855 
2856 static inline int __f2fs_get_curseg(struct f2fs_sb_info *sbi,
2857 						unsigned int segno)
2858 {
2859 	int i;
2860 
2861 	for (i = CURSEG_HOT_DATA; i < NO_CHECK_TYPE; i++) {
2862 		if (CURSEG_I(sbi, i)->segno == segno)
2863 			break;
2864 	}
2865 	return i;
2866 }
2867 
2868 void __f2fs_replace_block(struct f2fs_sb_info *sbi, struct f2fs_summary *sum,
2869 				block_t old_blkaddr, block_t new_blkaddr,
2870 				bool recover_curseg, bool recover_newaddr)
2871 {
2872 	struct sit_info *sit_i = SIT_I(sbi);
2873 	struct curseg_info *curseg;
2874 	unsigned int segno, old_cursegno;
2875 	struct seg_entry *se;
2876 	int type;
2877 	unsigned short old_blkoff;
2878 
2879 	segno = GET_SEGNO(sbi, new_blkaddr);
2880 	se = get_seg_entry(sbi, segno);
2881 	type = se->type;
2882 
2883 	down_write(&SM_I(sbi)->curseg_lock);
2884 
2885 	if (!recover_curseg) {
2886 		/* for recovery flow */
2887 		if (se->valid_blocks == 0 && !IS_CURSEG(sbi, segno)) {
2888 			if (old_blkaddr == NULL_ADDR)
2889 				type = CURSEG_COLD_DATA;
2890 			else
2891 				type = CURSEG_WARM_DATA;
2892 		}
2893 	} else {
2894 		if (IS_CURSEG(sbi, segno)) {
2895 			/* se->type is volatile as SSR allocation */
2896 			type = __f2fs_get_curseg(sbi, segno);
2897 			f2fs_bug_on(sbi, type == NO_CHECK_TYPE);
2898 		} else {
2899 			type = CURSEG_WARM_DATA;
2900 		}
2901 	}
2902 
2903 	f2fs_bug_on(sbi, !IS_DATASEG(type));
2904 	curseg = CURSEG_I(sbi, type);
2905 
2906 	mutex_lock(&curseg->curseg_mutex);
2907 	down_write(&sit_i->sentry_lock);
2908 
2909 	old_cursegno = curseg->segno;
2910 	old_blkoff = curseg->next_blkoff;
2911 
2912 	/* change the current segment */
2913 	if (segno != curseg->segno) {
2914 		curseg->next_segno = segno;
2915 		change_curseg(sbi, type);
2916 	}
2917 
2918 	curseg->next_blkoff = GET_BLKOFF_FROM_SEG0(sbi, new_blkaddr);
2919 	__add_sum_entry(sbi, type, sum);
2920 
2921 	if (!recover_curseg || recover_newaddr)
2922 		update_sit_entry(sbi, new_blkaddr, 1);
2923 	if (GET_SEGNO(sbi, old_blkaddr) != NULL_SEGNO)
2924 		update_sit_entry(sbi, old_blkaddr, -1);
2925 
2926 	locate_dirty_segment(sbi, GET_SEGNO(sbi, old_blkaddr));
2927 	locate_dirty_segment(sbi, GET_SEGNO(sbi, new_blkaddr));
2928 
2929 	locate_dirty_segment(sbi, old_cursegno);
2930 
2931 	if (recover_curseg) {
2932 		if (old_cursegno != curseg->segno) {
2933 			curseg->next_segno = old_cursegno;
2934 			change_curseg(sbi, type);
2935 		}
2936 		curseg->next_blkoff = old_blkoff;
2937 	}
2938 
2939 	up_write(&sit_i->sentry_lock);
2940 	mutex_unlock(&curseg->curseg_mutex);
2941 	up_write(&SM_I(sbi)->curseg_lock);
2942 }
2943 
2944 void f2fs_replace_block(struct f2fs_sb_info *sbi, struct dnode_of_data *dn,
2945 				block_t old_addr, block_t new_addr,
2946 				unsigned char version, bool recover_curseg,
2947 				bool recover_newaddr)
2948 {
2949 	struct f2fs_summary sum;
2950 
2951 	set_summary(&sum, dn->nid, dn->ofs_in_node, version);
2952 
2953 	__f2fs_replace_block(sbi, &sum, old_addr, new_addr,
2954 					recover_curseg, recover_newaddr);
2955 
2956 	f2fs_update_data_blkaddr(dn, new_addr);
2957 }
2958 
2959 void f2fs_wait_on_page_writeback(struct page *page,
2960 				enum page_type type, bool ordered)
2961 {
2962 	if (PageWriteback(page)) {
2963 		struct f2fs_sb_info *sbi = F2FS_P_SB(page);
2964 
2965 		f2fs_submit_merged_write_cond(sbi, page->mapping->host,
2966 						0, page->index, type);
2967 		if (ordered)
2968 			wait_on_page_writeback(page);
2969 		else
2970 			wait_for_stable_page(page);
2971 	}
2972 }
2973 
2974 void f2fs_wait_on_block_writeback(struct f2fs_sb_info *sbi, block_t blkaddr)
2975 {
2976 	struct page *cpage;
2977 
2978 	if (!is_valid_blkaddr(blkaddr))
2979 		return;
2980 
2981 	cpage = find_lock_page(META_MAPPING(sbi), blkaddr);
2982 	if (cpage) {
2983 		f2fs_wait_on_page_writeback(cpage, DATA, true);
2984 		f2fs_put_page(cpage, 1);
2985 	}
2986 }
2987 
2988 static void read_compacted_summaries(struct f2fs_sb_info *sbi)
2989 {
2990 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
2991 	struct curseg_info *seg_i;
2992 	unsigned char *kaddr;
2993 	struct page *page;
2994 	block_t start;
2995 	int i, j, offset;
2996 
2997 	start = start_sum_block(sbi);
2998 
2999 	page = get_meta_page(sbi, start++);
3000 	kaddr = (unsigned char *)page_address(page);
3001 
3002 	/* Step 1: restore nat cache */
3003 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
3004 	memcpy(seg_i->journal, kaddr, SUM_JOURNAL_SIZE);
3005 
3006 	/* Step 2: restore sit cache */
3007 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
3008 	memcpy(seg_i->journal, kaddr + SUM_JOURNAL_SIZE, SUM_JOURNAL_SIZE);
3009 	offset = 2 * SUM_JOURNAL_SIZE;
3010 
3011 	/* Step 3: restore summary entries */
3012 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
3013 		unsigned short blk_off;
3014 		unsigned int segno;
3015 
3016 		seg_i = CURSEG_I(sbi, i);
3017 		segno = le32_to_cpu(ckpt->cur_data_segno[i]);
3018 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[i]);
3019 		seg_i->next_segno = segno;
3020 		reset_curseg(sbi, i, 0);
3021 		seg_i->alloc_type = ckpt->alloc_type[i];
3022 		seg_i->next_blkoff = blk_off;
3023 
3024 		if (seg_i->alloc_type == SSR)
3025 			blk_off = sbi->blocks_per_seg;
3026 
3027 		for (j = 0; j < blk_off; j++) {
3028 			struct f2fs_summary *s;
3029 			s = (struct f2fs_summary *)(kaddr + offset);
3030 			seg_i->sum_blk->entries[j] = *s;
3031 			offset += SUMMARY_SIZE;
3032 			if (offset + SUMMARY_SIZE <= PAGE_SIZE -
3033 						SUM_FOOTER_SIZE)
3034 				continue;
3035 
3036 			f2fs_put_page(page, 1);
3037 			page = NULL;
3038 
3039 			page = get_meta_page(sbi, start++);
3040 			kaddr = (unsigned char *)page_address(page);
3041 			offset = 0;
3042 		}
3043 	}
3044 	f2fs_put_page(page, 1);
3045 }
3046 
3047 static int read_normal_summaries(struct f2fs_sb_info *sbi, int type)
3048 {
3049 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
3050 	struct f2fs_summary_block *sum;
3051 	struct curseg_info *curseg;
3052 	struct page *new;
3053 	unsigned short blk_off;
3054 	unsigned int segno = 0;
3055 	block_t blk_addr = 0;
3056 
3057 	/* get segment number and block addr */
3058 	if (IS_DATASEG(type)) {
3059 		segno = le32_to_cpu(ckpt->cur_data_segno[type]);
3060 		blk_off = le16_to_cpu(ckpt->cur_data_blkoff[type -
3061 							CURSEG_HOT_DATA]);
3062 		if (__exist_node_summaries(sbi))
3063 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_TYPE, type);
3064 		else
3065 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_DATA_TYPE, type);
3066 	} else {
3067 		segno = le32_to_cpu(ckpt->cur_node_segno[type -
3068 							CURSEG_HOT_NODE]);
3069 		blk_off = le16_to_cpu(ckpt->cur_node_blkoff[type -
3070 							CURSEG_HOT_NODE]);
3071 		if (__exist_node_summaries(sbi))
3072 			blk_addr = sum_blk_addr(sbi, NR_CURSEG_NODE_TYPE,
3073 							type - CURSEG_HOT_NODE);
3074 		else
3075 			blk_addr = GET_SUM_BLOCK(sbi, segno);
3076 	}
3077 
3078 	new = get_meta_page(sbi, blk_addr);
3079 	sum = (struct f2fs_summary_block *)page_address(new);
3080 
3081 	if (IS_NODESEG(type)) {
3082 		if (__exist_node_summaries(sbi)) {
3083 			struct f2fs_summary *ns = &sum->entries[0];
3084 			int i;
3085 			for (i = 0; i < sbi->blocks_per_seg; i++, ns++) {
3086 				ns->version = 0;
3087 				ns->ofs_in_node = 0;
3088 			}
3089 		} else {
3090 			restore_node_summary(sbi, segno, sum);
3091 		}
3092 	}
3093 
3094 	/* set uncompleted segment to curseg */
3095 	curseg = CURSEG_I(sbi, type);
3096 	mutex_lock(&curseg->curseg_mutex);
3097 
3098 	/* update journal info */
3099 	down_write(&curseg->journal_rwsem);
3100 	memcpy(curseg->journal, &sum->journal, SUM_JOURNAL_SIZE);
3101 	up_write(&curseg->journal_rwsem);
3102 
3103 	memcpy(curseg->sum_blk->entries, sum->entries, SUM_ENTRY_SIZE);
3104 	memcpy(&curseg->sum_blk->footer, &sum->footer, SUM_FOOTER_SIZE);
3105 	curseg->next_segno = segno;
3106 	reset_curseg(sbi, type, 0);
3107 	curseg->alloc_type = ckpt->alloc_type[type];
3108 	curseg->next_blkoff = blk_off;
3109 	mutex_unlock(&curseg->curseg_mutex);
3110 	f2fs_put_page(new, 1);
3111 	return 0;
3112 }
3113 
3114 static int restore_curseg_summaries(struct f2fs_sb_info *sbi)
3115 {
3116 	struct f2fs_journal *sit_j = CURSEG_I(sbi, CURSEG_COLD_DATA)->journal;
3117 	struct f2fs_journal *nat_j = CURSEG_I(sbi, CURSEG_HOT_DATA)->journal;
3118 	int type = CURSEG_HOT_DATA;
3119 	int err;
3120 
3121 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG)) {
3122 		int npages = npages_for_summary_flush(sbi, true);
3123 
3124 		if (npages >= 2)
3125 			ra_meta_pages(sbi, start_sum_block(sbi), npages,
3126 							META_CP, true);
3127 
3128 		/* restore for compacted data summary */
3129 		read_compacted_summaries(sbi);
3130 		type = CURSEG_HOT_NODE;
3131 	}
3132 
3133 	if (__exist_node_summaries(sbi))
3134 		ra_meta_pages(sbi, sum_blk_addr(sbi, NR_CURSEG_TYPE, type),
3135 					NR_CURSEG_TYPE - type, META_CP, true);
3136 
3137 	for (; type <= CURSEG_COLD_NODE; type++) {
3138 		err = read_normal_summaries(sbi, type);
3139 		if (err)
3140 			return err;
3141 	}
3142 
3143 	/* sanity check for summary blocks */
3144 	if (nats_in_cursum(nat_j) > NAT_JOURNAL_ENTRIES ||
3145 			sits_in_cursum(sit_j) > SIT_JOURNAL_ENTRIES)
3146 		return -EINVAL;
3147 
3148 	return 0;
3149 }
3150 
3151 static void write_compacted_summaries(struct f2fs_sb_info *sbi, block_t blkaddr)
3152 {
3153 	struct page *page;
3154 	unsigned char *kaddr;
3155 	struct f2fs_summary *summary;
3156 	struct curseg_info *seg_i;
3157 	int written_size = 0;
3158 	int i, j;
3159 
3160 	page = grab_meta_page(sbi, blkaddr++);
3161 	kaddr = (unsigned char *)page_address(page);
3162 	memset(kaddr, 0, PAGE_SIZE);
3163 
3164 	/* Step 1: write nat cache */
3165 	seg_i = CURSEG_I(sbi, CURSEG_HOT_DATA);
3166 	memcpy(kaddr, seg_i->journal, SUM_JOURNAL_SIZE);
3167 	written_size += SUM_JOURNAL_SIZE;
3168 
3169 	/* Step 2: write sit cache */
3170 	seg_i = CURSEG_I(sbi, CURSEG_COLD_DATA);
3171 	memcpy(kaddr + written_size, seg_i->journal, SUM_JOURNAL_SIZE);
3172 	written_size += SUM_JOURNAL_SIZE;
3173 
3174 	/* Step 3: write summary entries */
3175 	for (i = CURSEG_HOT_DATA; i <= CURSEG_COLD_DATA; i++) {
3176 		unsigned short blkoff;
3177 		seg_i = CURSEG_I(sbi, i);
3178 		if (sbi->ckpt->alloc_type[i] == SSR)
3179 			blkoff = sbi->blocks_per_seg;
3180 		else
3181 			blkoff = curseg_blkoff(sbi, i);
3182 
3183 		for (j = 0; j < blkoff; j++) {
3184 			if (!page) {
3185 				page = grab_meta_page(sbi, blkaddr++);
3186 				kaddr = (unsigned char *)page_address(page);
3187 				memset(kaddr, 0, PAGE_SIZE);
3188 				written_size = 0;
3189 			}
3190 			summary = (struct f2fs_summary *)(kaddr + written_size);
3191 			*summary = seg_i->sum_blk->entries[j];
3192 			written_size += SUMMARY_SIZE;
3193 
3194 			if (written_size + SUMMARY_SIZE <= PAGE_SIZE -
3195 							SUM_FOOTER_SIZE)
3196 				continue;
3197 
3198 			set_page_dirty(page);
3199 			f2fs_put_page(page, 1);
3200 			page = NULL;
3201 		}
3202 	}
3203 	if (page) {
3204 		set_page_dirty(page);
3205 		f2fs_put_page(page, 1);
3206 	}
3207 }
3208 
3209 static void write_normal_summaries(struct f2fs_sb_info *sbi,
3210 					block_t blkaddr, int type)
3211 {
3212 	int i, end;
3213 	if (IS_DATASEG(type))
3214 		end = type + NR_CURSEG_DATA_TYPE;
3215 	else
3216 		end = type + NR_CURSEG_NODE_TYPE;
3217 
3218 	for (i = type; i < end; i++)
3219 		write_current_sum_page(sbi, i, blkaddr + (i - type));
3220 }
3221 
3222 void write_data_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
3223 {
3224 	if (is_set_ckpt_flags(sbi, CP_COMPACT_SUM_FLAG))
3225 		write_compacted_summaries(sbi, start_blk);
3226 	else
3227 		write_normal_summaries(sbi, start_blk, CURSEG_HOT_DATA);
3228 }
3229 
3230 void write_node_summaries(struct f2fs_sb_info *sbi, block_t start_blk)
3231 {
3232 	write_normal_summaries(sbi, start_blk, CURSEG_HOT_NODE);
3233 }
3234 
3235 int lookup_journal_in_cursum(struct f2fs_journal *journal, int type,
3236 					unsigned int val, int alloc)
3237 {
3238 	int i;
3239 
3240 	if (type == NAT_JOURNAL) {
3241 		for (i = 0; i < nats_in_cursum(journal); i++) {
3242 			if (le32_to_cpu(nid_in_journal(journal, i)) == val)
3243 				return i;
3244 		}
3245 		if (alloc && __has_cursum_space(journal, 1, NAT_JOURNAL))
3246 			return update_nats_in_cursum(journal, 1);
3247 	} else if (type == SIT_JOURNAL) {
3248 		for (i = 0; i < sits_in_cursum(journal); i++)
3249 			if (le32_to_cpu(segno_in_journal(journal, i)) == val)
3250 				return i;
3251 		if (alloc && __has_cursum_space(journal, 1, SIT_JOURNAL))
3252 			return update_sits_in_cursum(journal, 1);
3253 	}
3254 	return -1;
3255 }
3256 
3257 static struct page *get_current_sit_page(struct f2fs_sb_info *sbi,
3258 					unsigned int segno)
3259 {
3260 	return get_meta_page(sbi, current_sit_addr(sbi, segno));
3261 }
3262 
3263 static struct page *get_next_sit_page(struct f2fs_sb_info *sbi,
3264 					unsigned int start)
3265 {
3266 	struct sit_info *sit_i = SIT_I(sbi);
3267 	struct page *page;
3268 	pgoff_t src_off, dst_off;
3269 
3270 	src_off = current_sit_addr(sbi, start);
3271 	dst_off = next_sit_addr(sbi, src_off);
3272 
3273 	page = grab_meta_page(sbi, dst_off);
3274 	seg_info_to_sit_page(sbi, page, start);
3275 
3276 	set_page_dirty(page);
3277 	set_to_next_sit(sit_i, start);
3278 
3279 	return page;
3280 }
3281 
3282 static struct sit_entry_set *grab_sit_entry_set(void)
3283 {
3284 	struct sit_entry_set *ses =
3285 			f2fs_kmem_cache_alloc(sit_entry_set_slab, GFP_NOFS);
3286 
3287 	ses->entry_cnt = 0;
3288 	INIT_LIST_HEAD(&ses->set_list);
3289 	return ses;
3290 }
3291 
3292 static void release_sit_entry_set(struct sit_entry_set *ses)
3293 {
3294 	list_del(&ses->set_list);
3295 	kmem_cache_free(sit_entry_set_slab, ses);
3296 }
3297 
3298 static void adjust_sit_entry_set(struct sit_entry_set *ses,
3299 						struct list_head *head)
3300 {
3301 	struct sit_entry_set *next = ses;
3302 
3303 	if (list_is_last(&ses->set_list, head))
3304 		return;
3305 
3306 	list_for_each_entry_continue(next, head, set_list)
3307 		if (ses->entry_cnt <= next->entry_cnt)
3308 			break;
3309 
3310 	list_move_tail(&ses->set_list, &next->set_list);
3311 }
3312 
3313 static void add_sit_entry(unsigned int segno, struct list_head *head)
3314 {
3315 	struct sit_entry_set *ses;
3316 	unsigned int start_segno = START_SEGNO(segno);
3317 
3318 	list_for_each_entry(ses, head, set_list) {
3319 		if (ses->start_segno == start_segno) {
3320 			ses->entry_cnt++;
3321 			adjust_sit_entry_set(ses, head);
3322 			return;
3323 		}
3324 	}
3325 
3326 	ses = grab_sit_entry_set();
3327 
3328 	ses->start_segno = start_segno;
3329 	ses->entry_cnt++;
3330 	list_add(&ses->set_list, head);
3331 }
3332 
3333 static void add_sits_in_set(struct f2fs_sb_info *sbi)
3334 {
3335 	struct f2fs_sm_info *sm_info = SM_I(sbi);
3336 	struct list_head *set_list = &sm_info->sit_entry_set;
3337 	unsigned long *bitmap = SIT_I(sbi)->dirty_sentries_bitmap;
3338 	unsigned int segno;
3339 
3340 	for_each_set_bit(segno, bitmap, MAIN_SEGS(sbi))
3341 		add_sit_entry(segno, set_list);
3342 }
3343 
3344 static void remove_sits_in_journal(struct f2fs_sb_info *sbi)
3345 {
3346 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
3347 	struct f2fs_journal *journal = curseg->journal;
3348 	int i;
3349 
3350 	down_write(&curseg->journal_rwsem);
3351 	for (i = 0; i < sits_in_cursum(journal); i++) {
3352 		unsigned int segno;
3353 		bool dirtied;
3354 
3355 		segno = le32_to_cpu(segno_in_journal(journal, i));
3356 		dirtied = __mark_sit_entry_dirty(sbi, segno);
3357 
3358 		if (!dirtied)
3359 			add_sit_entry(segno, &SM_I(sbi)->sit_entry_set);
3360 	}
3361 	update_sits_in_cursum(journal, -i);
3362 	up_write(&curseg->journal_rwsem);
3363 }
3364 
3365 /*
3366  * CP calls this function, which flushes SIT entries including sit_journal,
3367  * and moves prefree segs to free segs.
3368  */
3369 void flush_sit_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
3370 {
3371 	struct sit_info *sit_i = SIT_I(sbi);
3372 	unsigned long *bitmap = sit_i->dirty_sentries_bitmap;
3373 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
3374 	struct f2fs_journal *journal = curseg->journal;
3375 	struct sit_entry_set *ses, *tmp;
3376 	struct list_head *head = &SM_I(sbi)->sit_entry_set;
3377 	bool to_journal = true;
3378 	struct seg_entry *se;
3379 
3380 	down_write(&sit_i->sentry_lock);
3381 
3382 	if (!sit_i->dirty_sentries)
3383 		goto out;
3384 
3385 	/*
3386 	 * add and account sit entries of dirty bitmap in sit entry
3387 	 * set temporarily
3388 	 */
3389 	add_sits_in_set(sbi);
3390 
3391 	/*
3392 	 * if there are no enough space in journal to store dirty sit
3393 	 * entries, remove all entries from journal and add and account
3394 	 * them in sit entry set.
3395 	 */
3396 	if (!__has_cursum_space(journal, sit_i->dirty_sentries, SIT_JOURNAL))
3397 		remove_sits_in_journal(sbi);
3398 
3399 	/*
3400 	 * there are two steps to flush sit entries:
3401 	 * #1, flush sit entries to journal in current cold data summary block.
3402 	 * #2, flush sit entries to sit page.
3403 	 */
3404 	list_for_each_entry_safe(ses, tmp, head, set_list) {
3405 		struct page *page = NULL;
3406 		struct f2fs_sit_block *raw_sit = NULL;
3407 		unsigned int start_segno = ses->start_segno;
3408 		unsigned int end = min(start_segno + SIT_ENTRY_PER_BLOCK,
3409 						(unsigned long)MAIN_SEGS(sbi));
3410 		unsigned int segno = start_segno;
3411 
3412 		if (to_journal &&
3413 			!__has_cursum_space(journal, ses->entry_cnt, SIT_JOURNAL))
3414 			to_journal = false;
3415 
3416 		if (to_journal) {
3417 			down_write(&curseg->journal_rwsem);
3418 		} else {
3419 			page = get_next_sit_page(sbi, start_segno);
3420 			raw_sit = page_address(page);
3421 		}
3422 
3423 		/* flush dirty sit entries in region of current sit set */
3424 		for_each_set_bit_from(segno, bitmap, end) {
3425 			int offset, sit_offset;
3426 
3427 			se = get_seg_entry(sbi, segno);
3428 #ifdef CONFIG_F2FS_CHECK_FS
3429 			if (memcmp(se->cur_valid_map, se->cur_valid_map_mir,
3430 						SIT_VBLOCK_MAP_SIZE))
3431 				f2fs_bug_on(sbi, 1);
3432 #endif
3433 
3434 			/* add discard candidates */
3435 			if (!(cpc->reason & CP_DISCARD)) {
3436 				cpc->trim_start = segno;
3437 				add_discard_addrs(sbi, cpc, false);
3438 			}
3439 
3440 			if (to_journal) {
3441 				offset = lookup_journal_in_cursum(journal,
3442 							SIT_JOURNAL, segno, 1);
3443 				f2fs_bug_on(sbi, offset < 0);
3444 				segno_in_journal(journal, offset) =
3445 							cpu_to_le32(segno);
3446 				seg_info_to_raw_sit(se,
3447 					&sit_in_journal(journal, offset));
3448 				check_block_count(sbi, segno,
3449 					&sit_in_journal(journal, offset));
3450 			} else {
3451 				sit_offset = SIT_ENTRY_OFFSET(sit_i, segno);
3452 				seg_info_to_raw_sit(se,
3453 						&raw_sit->entries[sit_offset]);
3454 				check_block_count(sbi, segno,
3455 						&raw_sit->entries[sit_offset]);
3456 			}
3457 
3458 			__clear_bit(segno, bitmap);
3459 			sit_i->dirty_sentries--;
3460 			ses->entry_cnt--;
3461 		}
3462 
3463 		if (to_journal)
3464 			up_write(&curseg->journal_rwsem);
3465 		else
3466 			f2fs_put_page(page, 1);
3467 
3468 		f2fs_bug_on(sbi, ses->entry_cnt);
3469 		release_sit_entry_set(ses);
3470 	}
3471 
3472 	f2fs_bug_on(sbi, !list_empty(head));
3473 	f2fs_bug_on(sbi, sit_i->dirty_sentries);
3474 out:
3475 	if (cpc->reason & CP_DISCARD) {
3476 		__u64 trim_start = cpc->trim_start;
3477 
3478 		for (; cpc->trim_start <= cpc->trim_end; cpc->trim_start++)
3479 			add_discard_addrs(sbi, cpc, false);
3480 
3481 		cpc->trim_start = trim_start;
3482 	}
3483 	up_write(&sit_i->sentry_lock);
3484 
3485 	set_prefree_as_free_segments(sbi);
3486 }
3487 
3488 static int build_sit_info(struct f2fs_sb_info *sbi)
3489 {
3490 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
3491 	struct sit_info *sit_i;
3492 	unsigned int sit_segs, start;
3493 	char *src_bitmap;
3494 	unsigned int bitmap_size;
3495 
3496 	/* allocate memory for SIT information */
3497 	sit_i = f2fs_kzalloc(sbi, sizeof(struct sit_info), GFP_KERNEL);
3498 	if (!sit_i)
3499 		return -ENOMEM;
3500 
3501 	SM_I(sbi)->sit_info = sit_i;
3502 
3503 	sit_i->sentries = f2fs_kvzalloc(sbi, MAIN_SEGS(sbi) *
3504 					sizeof(struct seg_entry), GFP_KERNEL);
3505 	if (!sit_i->sentries)
3506 		return -ENOMEM;
3507 
3508 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
3509 	sit_i->dirty_sentries_bitmap = f2fs_kvzalloc(sbi, bitmap_size,
3510 								GFP_KERNEL);
3511 	if (!sit_i->dirty_sentries_bitmap)
3512 		return -ENOMEM;
3513 
3514 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
3515 		sit_i->sentries[start].cur_valid_map
3516 			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
3517 		sit_i->sentries[start].ckpt_valid_map
3518 			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
3519 		if (!sit_i->sentries[start].cur_valid_map ||
3520 				!sit_i->sentries[start].ckpt_valid_map)
3521 			return -ENOMEM;
3522 
3523 #ifdef CONFIG_F2FS_CHECK_FS
3524 		sit_i->sentries[start].cur_valid_map_mir
3525 			= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
3526 		if (!sit_i->sentries[start].cur_valid_map_mir)
3527 			return -ENOMEM;
3528 #endif
3529 
3530 		if (f2fs_discard_en(sbi)) {
3531 			sit_i->sentries[start].discard_map
3532 				= f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE,
3533 								GFP_KERNEL);
3534 			if (!sit_i->sentries[start].discard_map)
3535 				return -ENOMEM;
3536 		}
3537 	}
3538 
3539 	sit_i->tmp_map = f2fs_kzalloc(sbi, SIT_VBLOCK_MAP_SIZE, GFP_KERNEL);
3540 	if (!sit_i->tmp_map)
3541 		return -ENOMEM;
3542 
3543 	if (sbi->segs_per_sec > 1) {
3544 		sit_i->sec_entries = f2fs_kvzalloc(sbi, MAIN_SECS(sbi) *
3545 					sizeof(struct sec_entry), GFP_KERNEL);
3546 		if (!sit_i->sec_entries)
3547 			return -ENOMEM;
3548 	}
3549 
3550 	/* get information related with SIT */
3551 	sit_segs = le32_to_cpu(raw_super->segment_count_sit) >> 1;
3552 
3553 	/* setup SIT bitmap from ckeckpoint pack */
3554 	bitmap_size = __bitmap_size(sbi, SIT_BITMAP);
3555 	src_bitmap = __bitmap_ptr(sbi, SIT_BITMAP);
3556 
3557 	sit_i->sit_bitmap = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
3558 	if (!sit_i->sit_bitmap)
3559 		return -ENOMEM;
3560 
3561 #ifdef CONFIG_F2FS_CHECK_FS
3562 	sit_i->sit_bitmap_mir = kmemdup(src_bitmap, bitmap_size, GFP_KERNEL);
3563 	if (!sit_i->sit_bitmap_mir)
3564 		return -ENOMEM;
3565 #endif
3566 
3567 	/* init SIT information */
3568 	sit_i->s_ops = &default_salloc_ops;
3569 
3570 	sit_i->sit_base_addr = le32_to_cpu(raw_super->sit_blkaddr);
3571 	sit_i->sit_blocks = sit_segs << sbi->log_blocks_per_seg;
3572 	sit_i->written_valid_blocks = 0;
3573 	sit_i->bitmap_size = bitmap_size;
3574 	sit_i->dirty_sentries = 0;
3575 	sit_i->sents_per_block = SIT_ENTRY_PER_BLOCK;
3576 	sit_i->elapsed_time = le64_to_cpu(sbi->ckpt->elapsed_time);
3577 	sit_i->mounted_time = ktime_get_real_seconds();
3578 	init_rwsem(&sit_i->sentry_lock);
3579 	return 0;
3580 }
3581 
3582 static int build_free_segmap(struct f2fs_sb_info *sbi)
3583 {
3584 	struct free_segmap_info *free_i;
3585 	unsigned int bitmap_size, sec_bitmap_size;
3586 
3587 	/* allocate memory for free segmap information */
3588 	free_i = f2fs_kzalloc(sbi, sizeof(struct free_segmap_info), GFP_KERNEL);
3589 	if (!free_i)
3590 		return -ENOMEM;
3591 
3592 	SM_I(sbi)->free_info = free_i;
3593 
3594 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
3595 	free_i->free_segmap = f2fs_kvmalloc(sbi, bitmap_size, GFP_KERNEL);
3596 	if (!free_i->free_segmap)
3597 		return -ENOMEM;
3598 
3599 	sec_bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
3600 	free_i->free_secmap = f2fs_kvmalloc(sbi, sec_bitmap_size, GFP_KERNEL);
3601 	if (!free_i->free_secmap)
3602 		return -ENOMEM;
3603 
3604 	/* set all segments as dirty temporarily */
3605 	memset(free_i->free_segmap, 0xff, bitmap_size);
3606 	memset(free_i->free_secmap, 0xff, sec_bitmap_size);
3607 
3608 	/* init free segmap information */
3609 	free_i->start_segno = GET_SEGNO_FROM_SEG0(sbi, MAIN_BLKADDR(sbi));
3610 	free_i->free_segments = 0;
3611 	free_i->free_sections = 0;
3612 	spin_lock_init(&free_i->segmap_lock);
3613 	return 0;
3614 }
3615 
3616 static int build_curseg(struct f2fs_sb_info *sbi)
3617 {
3618 	struct curseg_info *array;
3619 	int i;
3620 
3621 	array = f2fs_kzalloc(sbi, sizeof(*array) * NR_CURSEG_TYPE, GFP_KERNEL);
3622 	if (!array)
3623 		return -ENOMEM;
3624 
3625 	SM_I(sbi)->curseg_array = array;
3626 
3627 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
3628 		mutex_init(&array[i].curseg_mutex);
3629 		array[i].sum_blk = f2fs_kzalloc(sbi, PAGE_SIZE, GFP_KERNEL);
3630 		if (!array[i].sum_blk)
3631 			return -ENOMEM;
3632 		init_rwsem(&array[i].journal_rwsem);
3633 		array[i].journal = f2fs_kzalloc(sbi,
3634 				sizeof(struct f2fs_journal), GFP_KERNEL);
3635 		if (!array[i].journal)
3636 			return -ENOMEM;
3637 		array[i].segno = NULL_SEGNO;
3638 		array[i].next_blkoff = 0;
3639 	}
3640 	return restore_curseg_summaries(sbi);
3641 }
3642 
3643 static int build_sit_entries(struct f2fs_sb_info *sbi)
3644 {
3645 	struct sit_info *sit_i = SIT_I(sbi);
3646 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_COLD_DATA);
3647 	struct f2fs_journal *journal = curseg->journal;
3648 	struct seg_entry *se;
3649 	struct f2fs_sit_entry sit;
3650 	int sit_blk_cnt = SIT_BLK_CNT(sbi);
3651 	unsigned int i, start, end;
3652 	unsigned int readed, start_blk = 0;
3653 	int err = 0;
3654 	block_t total_node_blocks = 0;
3655 
3656 	do {
3657 		readed = ra_meta_pages(sbi, start_blk, BIO_MAX_PAGES,
3658 							META_SIT, true);
3659 
3660 		start = start_blk * sit_i->sents_per_block;
3661 		end = (start_blk + readed) * sit_i->sents_per_block;
3662 
3663 		for (; start < end && start < MAIN_SEGS(sbi); start++) {
3664 			struct f2fs_sit_block *sit_blk;
3665 			struct page *page;
3666 
3667 			se = &sit_i->sentries[start];
3668 			page = get_current_sit_page(sbi, start);
3669 			sit_blk = (struct f2fs_sit_block *)page_address(page);
3670 			sit = sit_blk->entries[SIT_ENTRY_OFFSET(sit_i, start)];
3671 			f2fs_put_page(page, 1);
3672 
3673 			err = check_block_count(sbi, start, &sit);
3674 			if (err)
3675 				return err;
3676 			seg_info_from_raw_sit(se, &sit);
3677 			if (IS_NODESEG(se->type))
3678 				total_node_blocks += se->valid_blocks;
3679 
3680 			/* build discard map only one time */
3681 			if (f2fs_discard_en(sbi)) {
3682 				if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
3683 					memset(se->discard_map, 0xff,
3684 						SIT_VBLOCK_MAP_SIZE);
3685 				} else {
3686 					memcpy(se->discard_map,
3687 						se->cur_valid_map,
3688 						SIT_VBLOCK_MAP_SIZE);
3689 					sbi->discard_blks +=
3690 						sbi->blocks_per_seg -
3691 						se->valid_blocks;
3692 				}
3693 			}
3694 
3695 			if (sbi->segs_per_sec > 1)
3696 				get_sec_entry(sbi, start)->valid_blocks +=
3697 							se->valid_blocks;
3698 		}
3699 		start_blk += readed;
3700 	} while (start_blk < sit_blk_cnt);
3701 
3702 	down_read(&curseg->journal_rwsem);
3703 	for (i = 0; i < sits_in_cursum(journal); i++) {
3704 		unsigned int old_valid_blocks;
3705 
3706 		start = le32_to_cpu(segno_in_journal(journal, i));
3707 		if (start >= MAIN_SEGS(sbi)) {
3708 			f2fs_msg(sbi->sb, KERN_ERR,
3709 					"Wrong journal entry on segno %u",
3710 					start);
3711 			set_sbi_flag(sbi, SBI_NEED_FSCK);
3712 			err = -EINVAL;
3713 			break;
3714 		}
3715 
3716 		se = &sit_i->sentries[start];
3717 		sit = sit_in_journal(journal, i);
3718 
3719 		old_valid_blocks = se->valid_blocks;
3720 		if (IS_NODESEG(se->type))
3721 			total_node_blocks -= old_valid_blocks;
3722 
3723 		err = check_block_count(sbi, start, &sit);
3724 		if (err)
3725 			break;
3726 		seg_info_from_raw_sit(se, &sit);
3727 		if (IS_NODESEG(se->type))
3728 			total_node_blocks += se->valid_blocks;
3729 
3730 		if (f2fs_discard_en(sbi)) {
3731 			if (is_set_ckpt_flags(sbi, CP_TRIMMED_FLAG)) {
3732 				memset(se->discard_map, 0xff,
3733 							SIT_VBLOCK_MAP_SIZE);
3734 			} else {
3735 				memcpy(se->discard_map, se->cur_valid_map,
3736 							SIT_VBLOCK_MAP_SIZE);
3737 				sbi->discard_blks += old_valid_blocks;
3738 				sbi->discard_blks -= se->valid_blocks;
3739 			}
3740 		}
3741 
3742 		if (sbi->segs_per_sec > 1) {
3743 			get_sec_entry(sbi, start)->valid_blocks +=
3744 							se->valid_blocks;
3745 			get_sec_entry(sbi, start)->valid_blocks -=
3746 							old_valid_blocks;
3747 		}
3748 	}
3749 	up_read(&curseg->journal_rwsem);
3750 
3751 	if (!err && total_node_blocks != valid_node_count(sbi)) {
3752 		f2fs_msg(sbi->sb, KERN_ERR,
3753 			"SIT is corrupted node# %u vs %u",
3754 			total_node_blocks, valid_node_count(sbi));
3755 		set_sbi_flag(sbi, SBI_NEED_FSCK);
3756 		err = -EINVAL;
3757 	}
3758 
3759 	return err;
3760 }
3761 
3762 static void init_free_segmap(struct f2fs_sb_info *sbi)
3763 {
3764 	unsigned int start;
3765 	int type;
3766 
3767 	for (start = 0; start < MAIN_SEGS(sbi); start++) {
3768 		struct seg_entry *sentry = get_seg_entry(sbi, start);
3769 		if (!sentry->valid_blocks)
3770 			__set_free(sbi, start);
3771 		else
3772 			SIT_I(sbi)->written_valid_blocks +=
3773 						sentry->valid_blocks;
3774 	}
3775 
3776 	/* set use the current segments */
3777 	for (type = CURSEG_HOT_DATA; type <= CURSEG_COLD_NODE; type++) {
3778 		struct curseg_info *curseg_t = CURSEG_I(sbi, type);
3779 		__set_test_and_inuse(sbi, curseg_t->segno);
3780 	}
3781 }
3782 
3783 static void init_dirty_segmap(struct f2fs_sb_info *sbi)
3784 {
3785 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3786 	struct free_segmap_info *free_i = FREE_I(sbi);
3787 	unsigned int segno = 0, offset = 0;
3788 	unsigned short valid_blocks;
3789 
3790 	while (1) {
3791 		/* find dirty segment based on free segmap */
3792 		segno = find_next_inuse(free_i, MAIN_SEGS(sbi), offset);
3793 		if (segno >= MAIN_SEGS(sbi))
3794 			break;
3795 		offset = segno + 1;
3796 		valid_blocks = get_valid_blocks(sbi, segno, false);
3797 		if (valid_blocks == sbi->blocks_per_seg || !valid_blocks)
3798 			continue;
3799 		if (valid_blocks > sbi->blocks_per_seg) {
3800 			f2fs_bug_on(sbi, 1);
3801 			continue;
3802 		}
3803 		mutex_lock(&dirty_i->seglist_lock);
3804 		__locate_dirty_segment(sbi, segno, DIRTY);
3805 		mutex_unlock(&dirty_i->seglist_lock);
3806 	}
3807 }
3808 
3809 static int init_victim_secmap(struct f2fs_sb_info *sbi)
3810 {
3811 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3812 	unsigned int bitmap_size = f2fs_bitmap_size(MAIN_SECS(sbi));
3813 
3814 	dirty_i->victim_secmap = f2fs_kvzalloc(sbi, bitmap_size, GFP_KERNEL);
3815 	if (!dirty_i->victim_secmap)
3816 		return -ENOMEM;
3817 	return 0;
3818 }
3819 
3820 static int build_dirty_segmap(struct f2fs_sb_info *sbi)
3821 {
3822 	struct dirty_seglist_info *dirty_i;
3823 	unsigned int bitmap_size, i;
3824 
3825 	/* allocate memory for dirty segments list information */
3826 	dirty_i = f2fs_kzalloc(sbi, sizeof(struct dirty_seglist_info),
3827 								GFP_KERNEL);
3828 	if (!dirty_i)
3829 		return -ENOMEM;
3830 
3831 	SM_I(sbi)->dirty_info = dirty_i;
3832 	mutex_init(&dirty_i->seglist_lock);
3833 
3834 	bitmap_size = f2fs_bitmap_size(MAIN_SEGS(sbi));
3835 
3836 	for (i = 0; i < NR_DIRTY_TYPE; i++) {
3837 		dirty_i->dirty_segmap[i] = f2fs_kvzalloc(sbi, bitmap_size,
3838 								GFP_KERNEL);
3839 		if (!dirty_i->dirty_segmap[i])
3840 			return -ENOMEM;
3841 	}
3842 
3843 	init_dirty_segmap(sbi);
3844 	return init_victim_secmap(sbi);
3845 }
3846 
3847 /*
3848  * Update min, max modified time for cost-benefit GC algorithm
3849  */
3850 static void init_min_max_mtime(struct f2fs_sb_info *sbi)
3851 {
3852 	struct sit_info *sit_i = SIT_I(sbi);
3853 	unsigned int segno;
3854 
3855 	down_write(&sit_i->sentry_lock);
3856 
3857 	sit_i->min_mtime = ULLONG_MAX;
3858 
3859 	for (segno = 0; segno < MAIN_SEGS(sbi); segno += sbi->segs_per_sec) {
3860 		unsigned int i;
3861 		unsigned long long mtime = 0;
3862 
3863 		for (i = 0; i < sbi->segs_per_sec; i++)
3864 			mtime += get_seg_entry(sbi, segno + i)->mtime;
3865 
3866 		mtime = div_u64(mtime, sbi->segs_per_sec);
3867 
3868 		if (sit_i->min_mtime > mtime)
3869 			sit_i->min_mtime = mtime;
3870 	}
3871 	sit_i->max_mtime = get_mtime(sbi);
3872 	up_write(&sit_i->sentry_lock);
3873 }
3874 
3875 int build_segment_manager(struct f2fs_sb_info *sbi)
3876 {
3877 	struct f2fs_super_block *raw_super = F2FS_RAW_SUPER(sbi);
3878 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
3879 	struct f2fs_sm_info *sm_info;
3880 	int err;
3881 
3882 	sm_info = f2fs_kzalloc(sbi, sizeof(struct f2fs_sm_info), GFP_KERNEL);
3883 	if (!sm_info)
3884 		return -ENOMEM;
3885 
3886 	/* init sm info */
3887 	sbi->sm_info = sm_info;
3888 	sm_info->seg0_blkaddr = le32_to_cpu(raw_super->segment0_blkaddr);
3889 	sm_info->main_blkaddr = le32_to_cpu(raw_super->main_blkaddr);
3890 	sm_info->segment_count = le32_to_cpu(raw_super->segment_count);
3891 	sm_info->reserved_segments = le32_to_cpu(ckpt->rsvd_segment_count);
3892 	sm_info->ovp_segments = le32_to_cpu(ckpt->overprov_segment_count);
3893 	sm_info->main_segments = le32_to_cpu(raw_super->segment_count_main);
3894 	sm_info->ssa_blkaddr = le32_to_cpu(raw_super->ssa_blkaddr);
3895 	sm_info->rec_prefree_segments = sm_info->main_segments *
3896 					DEF_RECLAIM_PREFREE_SEGMENTS / 100;
3897 	if (sm_info->rec_prefree_segments > DEF_MAX_RECLAIM_PREFREE_SEGMENTS)
3898 		sm_info->rec_prefree_segments = DEF_MAX_RECLAIM_PREFREE_SEGMENTS;
3899 
3900 	if (!test_opt(sbi, LFS))
3901 		sm_info->ipu_policy = 1 << F2FS_IPU_FSYNC;
3902 	sm_info->min_ipu_util = DEF_MIN_IPU_UTIL;
3903 	sm_info->min_fsync_blocks = DEF_MIN_FSYNC_BLOCKS;
3904 	sm_info->min_hot_blocks = DEF_MIN_HOT_BLOCKS;
3905 	sm_info->min_ssr_sections = reserved_sections(sbi);
3906 
3907 	INIT_LIST_HEAD(&sm_info->sit_entry_set);
3908 
3909 	init_rwsem(&sm_info->curseg_lock);
3910 
3911 	if (!f2fs_readonly(sbi->sb)) {
3912 		err = create_flush_cmd_control(sbi);
3913 		if (err)
3914 			return err;
3915 	}
3916 
3917 	err = create_discard_cmd_control(sbi);
3918 	if (err)
3919 		return err;
3920 
3921 	err = build_sit_info(sbi);
3922 	if (err)
3923 		return err;
3924 	err = build_free_segmap(sbi);
3925 	if (err)
3926 		return err;
3927 	err = build_curseg(sbi);
3928 	if (err)
3929 		return err;
3930 
3931 	/* reinit free segmap based on SIT */
3932 	err = build_sit_entries(sbi);
3933 	if (err)
3934 		return err;
3935 
3936 	init_free_segmap(sbi);
3937 	err = build_dirty_segmap(sbi);
3938 	if (err)
3939 		return err;
3940 
3941 	init_min_max_mtime(sbi);
3942 	return 0;
3943 }
3944 
3945 static void discard_dirty_segmap(struct f2fs_sb_info *sbi,
3946 		enum dirty_type dirty_type)
3947 {
3948 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3949 
3950 	mutex_lock(&dirty_i->seglist_lock);
3951 	kvfree(dirty_i->dirty_segmap[dirty_type]);
3952 	dirty_i->nr_dirty[dirty_type] = 0;
3953 	mutex_unlock(&dirty_i->seglist_lock);
3954 }
3955 
3956 static void destroy_victim_secmap(struct f2fs_sb_info *sbi)
3957 {
3958 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3959 	kvfree(dirty_i->victim_secmap);
3960 }
3961 
3962 static void destroy_dirty_segmap(struct f2fs_sb_info *sbi)
3963 {
3964 	struct dirty_seglist_info *dirty_i = DIRTY_I(sbi);
3965 	int i;
3966 
3967 	if (!dirty_i)
3968 		return;
3969 
3970 	/* discard pre-free/dirty segments list */
3971 	for (i = 0; i < NR_DIRTY_TYPE; i++)
3972 		discard_dirty_segmap(sbi, i);
3973 
3974 	destroy_victim_secmap(sbi);
3975 	SM_I(sbi)->dirty_info = NULL;
3976 	kfree(dirty_i);
3977 }
3978 
3979 static void destroy_curseg(struct f2fs_sb_info *sbi)
3980 {
3981 	struct curseg_info *array = SM_I(sbi)->curseg_array;
3982 	int i;
3983 
3984 	if (!array)
3985 		return;
3986 	SM_I(sbi)->curseg_array = NULL;
3987 	for (i = 0; i < NR_CURSEG_TYPE; i++) {
3988 		kfree(array[i].sum_blk);
3989 		kfree(array[i].journal);
3990 	}
3991 	kfree(array);
3992 }
3993 
3994 static void destroy_free_segmap(struct f2fs_sb_info *sbi)
3995 {
3996 	struct free_segmap_info *free_i = SM_I(sbi)->free_info;
3997 	if (!free_i)
3998 		return;
3999 	SM_I(sbi)->free_info = NULL;
4000 	kvfree(free_i->free_segmap);
4001 	kvfree(free_i->free_secmap);
4002 	kfree(free_i);
4003 }
4004 
4005 static void destroy_sit_info(struct f2fs_sb_info *sbi)
4006 {
4007 	struct sit_info *sit_i = SIT_I(sbi);
4008 	unsigned int start;
4009 
4010 	if (!sit_i)
4011 		return;
4012 
4013 	if (sit_i->sentries) {
4014 		for (start = 0; start < MAIN_SEGS(sbi); start++) {
4015 			kfree(sit_i->sentries[start].cur_valid_map);
4016 #ifdef CONFIG_F2FS_CHECK_FS
4017 			kfree(sit_i->sentries[start].cur_valid_map_mir);
4018 #endif
4019 			kfree(sit_i->sentries[start].ckpt_valid_map);
4020 			kfree(sit_i->sentries[start].discard_map);
4021 		}
4022 	}
4023 	kfree(sit_i->tmp_map);
4024 
4025 	kvfree(sit_i->sentries);
4026 	kvfree(sit_i->sec_entries);
4027 	kvfree(sit_i->dirty_sentries_bitmap);
4028 
4029 	SM_I(sbi)->sit_info = NULL;
4030 	kfree(sit_i->sit_bitmap);
4031 #ifdef CONFIG_F2FS_CHECK_FS
4032 	kfree(sit_i->sit_bitmap_mir);
4033 #endif
4034 	kfree(sit_i);
4035 }
4036 
4037 void destroy_segment_manager(struct f2fs_sb_info *sbi)
4038 {
4039 	struct f2fs_sm_info *sm_info = SM_I(sbi);
4040 
4041 	if (!sm_info)
4042 		return;
4043 	destroy_flush_cmd_control(sbi, true);
4044 	destroy_discard_cmd_control(sbi);
4045 	destroy_dirty_segmap(sbi);
4046 	destroy_curseg(sbi);
4047 	destroy_free_segmap(sbi);
4048 	destroy_sit_info(sbi);
4049 	sbi->sm_info = NULL;
4050 	kfree(sm_info);
4051 }
4052 
4053 int __init create_segment_manager_caches(void)
4054 {
4055 	discard_entry_slab = f2fs_kmem_cache_create("discard_entry",
4056 			sizeof(struct discard_entry));
4057 	if (!discard_entry_slab)
4058 		goto fail;
4059 
4060 	discard_cmd_slab = f2fs_kmem_cache_create("discard_cmd",
4061 			sizeof(struct discard_cmd));
4062 	if (!discard_cmd_slab)
4063 		goto destroy_discard_entry;
4064 
4065 	sit_entry_set_slab = f2fs_kmem_cache_create("sit_entry_set",
4066 			sizeof(struct sit_entry_set));
4067 	if (!sit_entry_set_slab)
4068 		goto destroy_discard_cmd;
4069 
4070 	inmem_entry_slab = f2fs_kmem_cache_create("inmem_page_entry",
4071 			sizeof(struct inmem_pages));
4072 	if (!inmem_entry_slab)
4073 		goto destroy_sit_entry_set;
4074 	return 0;
4075 
4076 destroy_sit_entry_set:
4077 	kmem_cache_destroy(sit_entry_set_slab);
4078 destroy_discard_cmd:
4079 	kmem_cache_destroy(discard_cmd_slab);
4080 destroy_discard_entry:
4081 	kmem_cache_destroy(discard_entry_slab);
4082 fail:
4083 	return -ENOMEM;
4084 }
4085 
4086 void destroy_segment_manager_caches(void)
4087 {
4088 	kmem_cache_destroy(sit_entry_set_slab);
4089 	kmem_cache_destroy(discard_cmd_slab);
4090 	kmem_cache_destroy(discard_entry_slab);
4091 	kmem_cache_destroy(inmem_entry_slab);
4092 }
4093