xref: /openbmc/linux/fs/f2fs/node.c (revision 979ac5ef)
1 // SPDX-License-Identifier: GPL-2.0
2 /*
3  * fs/f2fs/node.c
4  *
5  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
6  *             http://www.samsung.com/
7  */
8 #include <linux/fs.h>
9 #include <linux/f2fs_fs.h>
10 #include <linux/mpage.h>
11 #include <linux/sched/mm.h>
12 #include <linux/blkdev.h>
13 #include <linux/pagevec.h>
14 #include <linux/swap.h>
15 
16 #include "f2fs.h"
17 #include "node.h"
18 #include "segment.h"
19 #include "xattr.h"
20 #include "iostat.h"
21 #include <trace/events/f2fs.h>
22 
23 #define on_f2fs_build_free_nids(nmi) mutex_is_locked(&(nm_i)->build_lock)
24 
25 static struct kmem_cache *nat_entry_slab;
26 static struct kmem_cache *free_nid_slab;
27 static struct kmem_cache *nat_entry_set_slab;
28 static struct kmem_cache *fsync_node_entry_slab;
29 
30 /*
31  * Check whether the given nid is within node id range.
32  */
33 int f2fs_check_nid_range(struct f2fs_sb_info *sbi, nid_t nid)
34 {
35 	if (unlikely(nid < F2FS_ROOT_INO(sbi) || nid >= NM_I(sbi)->max_nid)) {
36 		set_sbi_flag(sbi, SBI_NEED_FSCK);
37 		f2fs_warn(sbi, "%s: out-of-range nid=%x, run fsck to fix.",
38 			  __func__, nid);
39 		f2fs_handle_error(sbi, ERROR_CORRUPTED_INODE);
40 		return -EFSCORRUPTED;
41 	}
42 	return 0;
43 }
44 
45 bool f2fs_available_free_memory(struct f2fs_sb_info *sbi, int type)
46 {
47 	struct f2fs_nm_info *nm_i = NM_I(sbi);
48 	struct discard_cmd_control *dcc = SM_I(sbi)->dcc_info;
49 	struct sysinfo val;
50 	unsigned long avail_ram;
51 	unsigned long mem_size = 0;
52 	bool res = false;
53 
54 	if (!nm_i)
55 		return true;
56 
57 	si_meminfo(&val);
58 
59 	/* only uses low memory */
60 	avail_ram = val.totalram - val.totalhigh;
61 
62 	/*
63 	 * give 25%, 25%, 50%, 50%, 25%, 25% memory for each components respectively
64 	 */
65 	if (type == FREE_NIDS) {
66 		mem_size = (nm_i->nid_cnt[FREE_NID] *
67 				sizeof(struct free_nid)) >> PAGE_SHIFT;
68 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
69 	} else if (type == NAT_ENTRIES) {
70 		mem_size = (nm_i->nat_cnt[TOTAL_NAT] *
71 				sizeof(struct nat_entry)) >> PAGE_SHIFT;
72 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
73 		if (excess_cached_nats(sbi))
74 			res = false;
75 	} else if (type == DIRTY_DENTS) {
76 		if (sbi->sb->s_bdi->wb.dirty_exceeded)
77 			return false;
78 		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
79 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
80 	} else if (type == INO_ENTRIES) {
81 		int i;
82 
83 		for (i = 0; i < MAX_INO_ENTRY; i++)
84 			mem_size += sbi->im[i].ino_num *
85 						sizeof(struct ino_entry);
86 		mem_size >>= PAGE_SHIFT;
87 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
88 	} else if (type == READ_EXTENT_CACHE || type == AGE_EXTENT_CACHE) {
89 		enum extent_type etype = type == READ_EXTENT_CACHE ?
90 						EX_READ : EX_BLOCK_AGE;
91 		struct extent_tree_info *eti = &sbi->extent_tree[etype];
92 
93 		mem_size = (atomic_read(&eti->total_ext_tree) *
94 				sizeof(struct extent_tree) +
95 				atomic_read(&eti->total_ext_node) *
96 				sizeof(struct extent_node)) >> PAGE_SHIFT;
97 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
98 	} else if (type == DISCARD_CACHE) {
99 		mem_size = (atomic_read(&dcc->discard_cmd_cnt) *
100 				sizeof(struct discard_cmd)) >> PAGE_SHIFT;
101 		res = mem_size < (avail_ram * nm_i->ram_thresh / 100);
102 	} else if (type == COMPRESS_PAGE) {
103 #ifdef CONFIG_F2FS_FS_COMPRESSION
104 		unsigned long free_ram = val.freeram;
105 
106 		/*
107 		 * free memory is lower than watermark or cached page count
108 		 * exceed threshold, deny caching compress page.
109 		 */
110 		res = (free_ram > avail_ram * sbi->compress_watermark / 100) &&
111 			(COMPRESS_MAPPING(sbi)->nrpages <
112 			 free_ram * sbi->compress_percent / 100);
113 #else
114 		res = false;
115 #endif
116 	} else {
117 		if (!sbi->sb->s_bdi->wb.dirty_exceeded)
118 			return true;
119 	}
120 	return res;
121 }
122 
123 static void clear_node_page_dirty(struct page *page)
124 {
125 	if (PageDirty(page)) {
126 		f2fs_clear_page_cache_dirty_tag(page);
127 		clear_page_dirty_for_io(page);
128 		dec_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
129 	}
130 	ClearPageUptodate(page);
131 }
132 
133 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
134 {
135 	return f2fs_get_meta_page_retry(sbi, current_nat_addr(sbi, nid));
136 }
137 
138 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
139 {
140 	struct page *src_page;
141 	struct page *dst_page;
142 	pgoff_t dst_off;
143 	void *src_addr;
144 	void *dst_addr;
145 	struct f2fs_nm_info *nm_i = NM_I(sbi);
146 
147 	dst_off = next_nat_addr(sbi, current_nat_addr(sbi, nid));
148 
149 	/* get current nat block page with lock */
150 	src_page = get_current_nat_page(sbi, nid);
151 	if (IS_ERR(src_page))
152 		return src_page;
153 	dst_page = f2fs_grab_meta_page(sbi, dst_off);
154 	f2fs_bug_on(sbi, PageDirty(src_page));
155 
156 	src_addr = page_address(src_page);
157 	dst_addr = page_address(dst_page);
158 	memcpy(dst_addr, src_addr, PAGE_SIZE);
159 	set_page_dirty(dst_page);
160 	f2fs_put_page(src_page, 1);
161 
162 	set_to_next_nat(nm_i, nid);
163 
164 	return dst_page;
165 }
166 
167 static struct nat_entry *__alloc_nat_entry(struct f2fs_sb_info *sbi,
168 						nid_t nid, bool no_fail)
169 {
170 	struct nat_entry *new;
171 
172 	new = f2fs_kmem_cache_alloc(nat_entry_slab,
173 					GFP_F2FS_ZERO, no_fail, sbi);
174 	if (new) {
175 		nat_set_nid(new, nid);
176 		nat_reset_flag(new);
177 	}
178 	return new;
179 }
180 
181 static void __free_nat_entry(struct nat_entry *e)
182 {
183 	kmem_cache_free(nat_entry_slab, e);
184 }
185 
186 /* must be locked by nat_tree_lock */
187 static struct nat_entry *__init_nat_entry(struct f2fs_nm_info *nm_i,
188 	struct nat_entry *ne, struct f2fs_nat_entry *raw_ne, bool no_fail)
189 {
190 	if (no_fail)
191 		f2fs_radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne);
192 	else if (radix_tree_insert(&nm_i->nat_root, nat_get_nid(ne), ne))
193 		return NULL;
194 
195 	if (raw_ne)
196 		node_info_from_raw_nat(&ne->ni, raw_ne);
197 
198 	spin_lock(&nm_i->nat_list_lock);
199 	list_add_tail(&ne->list, &nm_i->nat_entries);
200 	spin_unlock(&nm_i->nat_list_lock);
201 
202 	nm_i->nat_cnt[TOTAL_NAT]++;
203 	nm_i->nat_cnt[RECLAIMABLE_NAT]++;
204 	return ne;
205 }
206 
207 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
208 {
209 	struct nat_entry *ne;
210 
211 	ne = radix_tree_lookup(&nm_i->nat_root, n);
212 
213 	/* for recent accessed nat entry, move it to tail of lru list */
214 	if (ne && !get_nat_flag(ne, IS_DIRTY)) {
215 		spin_lock(&nm_i->nat_list_lock);
216 		if (!list_empty(&ne->list))
217 			list_move_tail(&ne->list, &nm_i->nat_entries);
218 		spin_unlock(&nm_i->nat_list_lock);
219 	}
220 
221 	return ne;
222 }
223 
224 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
225 		nid_t start, unsigned int nr, struct nat_entry **ep)
226 {
227 	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
228 }
229 
230 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
231 {
232 	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
233 	nm_i->nat_cnt[TOTAL_NAT]--;
234 	nm_i->nat_cnt[RECLAIMABLE_NAT]--;
235 	__free_nat_entry(e);
236 }
237 
238 static struct nat_entry_set *__grab_nat_entry_set(struct f2fs_nm_info *nm_i,
239 							struct nat_entry *ne)
240 {
241 	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
242 	struct nat_entry_set *head;
243 
244 	head = radix_tree_lookup(&nm_i->nat_set_root, set);
245 	if (!head) {
246 		head = f2fs_kmem_cache_alloc(nat_entry_set_slab,
247 						GFP_NOFS, true, NULL);
248 
249 		INIT_LIST_HEAD(&head->entry_list);
250 		INIT_LIST_HEAD(&head->set_list);
251 		head->set = set;
252 		head->entry_cnt = 0;
253 		f2fs_radix_tree_insert(&nm_i->nat_set_root, set, head);
254 	}
255 	return head;
256 }
257 
258 static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
259 						struct nat_entry *ne)
260 {
261 	struct nat_entry_set *head;
262 	bool new_ne = nat_get_blkaddr(ne) == NEW_ADDR;
263 
264 	if (!new_ne)
265 		head = __grab_nat_entry_set(nm_i, ne);
266 
267 	/*
268 	 * update entry_cnt in below condition:
269 	 * 1. update NEW_ADDR to valid block address;
270 	 * 2. update old block address to new one;
271 	 */
272 	if (!new_ne && (get_nat_flag(ne, IS_PREALLOC) ||
273 				!get_nat_flag(ne, IS_DIRTY)))
274 		head->entry_cnt++;
275 
276 	set_nat_flag(ne, IS_PREALLOC, new_ne);
277 
278 	if (get_nat_flag(ne, IS_DIRTY))
279 		goto refresh_list;
280 
281 	nm_i->nat_cnt[DIRTY_NAT]++;
282 	nm_i->nat_cnt[RECLAIMABLE_NAT]--;
283 	set_nat_flag(ne, IS_DIRTY, true);
284 refresh_list:
285 	spin_lock(&nm_i->nat_list_lock);
286 	if (new_ne)
287 		list_del_init(&ne->list);
288 	else
289 		list_move_tail(&ne->list, &head->entry_list);
290 	spin_unlock(&nm_i->nat_list_lock);
291 }
292 
293 static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
294 		struct nat_entry_set *set, struct nat_entry *ne)
295 {
296 	spin_lock(&nm_i->nat_list_lock);
297 	list_move_tail(&ne->list, &nm_i->nat_entries);
298 	spin_unlock(&nm_i->nat_list_lock);
299 
300 	set_nat_flag(ne, IS_DIRTY, false);
301 	set->entry_cnt--;
302 	nm_i->nat_cnt[DIRTY_NAT]--;
303 	nm_i->nat_cnt[RECLAIMABLE_NAT]++;
304 }
305 
306 static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
307 		nid_t start, unsigned int nr, struct nat_entry_set **ep)
308 {
309 	return radix_tree_gang_lookup(&nm_i->nat_set_root, (void **)ep,
310 							start, nr);
311 }
312 
313 bool f2fs_in_warm_node_list(struct f2fs_sb_info *sbi, struct page *page)
314 {
315 	return NODE_MAPPING(sbi) == page->mapping &&
316 			IS_DNODE(page) && is_cold_node(page);
317 }
318 
319 void f2fs_init_fsync_node_info(struct f2fs_sb_info *sbi)
320 {
321 	spin_lock_init(&sbi->fsync_node_lock);
322 	INIT_LIST_HEAD(&sbi->fsync_node_list);
323 	sbi->fsync_seg_id = 0;
324 	sbi->fsync_node_num = 0;
325 }
326 
327 static unsigned int f2fs_add_fsync_node_entry(struct f2fs_sb_info *sbi,
328 							struct page *page)
329 {
330 	struct fsync_node_entry *fn;
331 	unsigned long flags;
332 	unsigned int seq_id;
333 
334 	fn = f2fs_kmem_cache_alloc(fsync_node_entry_slab,
335 					GFP_NOFS, true, NULL);
336 
337 	get_page(page);
338 	fn->page = page;
339 	INIT_LIST_HEAD(&fn->list);
340 
341 	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
342 	list_add_tail(&fn->list, &sbi->fsync_node_list);
343 	fn->seq_id = sbi->fsync_seg_id++;
344 	seq_id = fn->seq_id;
345 	sbi->fsync_node_num++;
346 	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
347 
348 	return seq_id;
349 }
350 
351 void f2fs_del_fsync_node_entry(struct f2fs_sb_info *sbi, struct page *page)
352 {
353 	struct fsync_node_entry *fn;
354 	unsigned long flags;
355 
356 	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
357 	list_for_each_entry(fn, &sbi->fsync_node_list, list) {
358 		if (fn->page == page) {
359 			list_del(&fn->list);
360 			sbi->fsync_node_num--;
361 			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
362 			kmem_cache_free(fsync_node_entry_slab, fn);
363 			put_page(page);
364 			return;
365 		}
366 	}
367 	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
368 	f2fs_bug_on(sbi, 1);
369 }
370 
371 void f2fs_reset_fsync_node_info(struct f2fs_sb_info *sbi)
372 {
373 	unsigned long flags;
374 
375 	spin_lock_irqsave(&sbi->fsync_node_lock, flags);
376 	sbi->fsync_seg_id = 0;
377 	spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
378 }
379 
380 int f2fs_need_dentry_mark(struct f2fs_sb_info *sbi, nid_t nid)
381 {
382 	struct f2fs_nm_info *nm_i = NM_I(sbi);
383 	struct nat_entry *e;
384 	bool need = false;
385 
386 	f2fs_down_read(&nm_i->nat_tree_lock);
387 	e = __lookup_nat_cache(nm_i, nid);
388 	if (e) {
389 		if (!get_nat_flag(e, IS_CHECKPOINTED) &&
390 				!get_nat_flag(e, HAS_FSYNCED_INODE))
391 			need = true;
392 	}
393 	f2fs_up_read(&nm_i->nat_tree_lock);
394 	return need;
395 }
396 
397 bool f2fs_is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
398 {
399 	struct f2fs_nm_info *nm_i = NM_I(sbi);
400 	struct nat_entry *e;
401 	bool is_cp = true;
402 
403 	f2fs_down_read(&nm_i->nat_tree_lock);
404 	e = __lookup_nat_cache(nm_i, nid);
405 	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
406 		is_cp = false;
407 	f2fs_up_read(&nm_i->nat_tree_lock);
408 	return is_cp;
409 }
410 
411 bool f2fs_need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
412 {
413 	struct f2fs_nm_info *nm_i = NM_I(sbi);
414 	struct nat_entry *e;
415 	bool need_update = true;
416 
417 	f2fs_down_read(&nm_i->nat_tree_lock);
418 	e = __lookup_nat_cache(nm_i, ino);
419 	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
420 			(get_nat_flag(e, IS_CHECKPOINTED) ||
421 			 get_nat_flag(e, HAS_FSYNCED_INODE)))
422 		need_update = false;
423 	f2fs_up_read(&nm_i->nat_tree_lock);
424 	return need_update;
425 }
426 
427 /* must be locked by nat_tree_lock */
428 static void cache_nat_entry(struct f2fs_sb_info *sbi, nid_t nid,
429 						struct f2fs_nat_entry *ne)
430 {
431 	struct f2fs_nm_info *nm_i = NM_I(sbi);
432 	struct nat_entry *new, *e;
433 
434 	/* Let's mitigate lock contention of nat_tree_lock during checkpoint */
435 	if (f2fs_rwsem_is_locked(&sbi->cp_global_sem))
436 		return;
437 
438 	new = __alloc_nat_entry(sbi, nid, false);
439 	if (!new)
440 		return;
441 
442 	f2fs_down_write(&nm_i->nat_tree_lock);
443 	e = __lookup_nat_cache(nm_i, nid);
444 	if (!e)
445 		e = __init_nat_entry(nm_i, new, ne, false);
446 	else
447 		f2fs_bug_on(sbi, nat_get_ino(e) != le32_to_cpu(ne->ino) ||
448 				nat_get_blkaddr(e) !=
449 					le32_to_cpu(ne->block_addr) ||
450 				nat_get_version(e) != ne->version);
451 	f2fs_up_write(&nm_i->nat_tree_lock);
452 	if (e != new)
453 		__free_nat_entry(new);
454 }
455 
456 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
457 			block_t new_blkaddr, bool fsync_done)
458 {
459 	struct f2fs_nm_info *nm_i = NM_I(sbi);
460 	struct nat_entry *e;
461 	struct nat_entry *new = __alloc_nat_entry(sbi, ni->nid, true);
462 
463 	f2fs_down_write(&nm_i->nat_tree_lock);
464 	e = __lookup_nat_cache(nm_i, ni->nid);
465 	if (!e) {
466 		e = __init_nat_entry(nm_i, new, NULL, true);
467 		copy_node_info(&e->ni, ni);
468 		f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
469 	} else if (new_blkaddr == NEW_ADDR) {
470 		/*
471 		 * when nid is reallocated,
472 		 * previous nat entry can be remained in nat cache.
473 		 * So, reinitialize it with new information.
474 		 */
475 		copy_node_info(&e->ni, ni);
476 		f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
477 	}
478 	/* let's free early to reduce memory consumption */
479 	if (e != new)
480 		__free_nat_entry(new);
481 
482 	/* sanity check */
483 	f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
484 	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NULL_ADDR &&
485 			new_blkaddr == NULL_ADDR);
486 	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NEW_ADDR &&
487 			new_blkaddr == NEW_ADDR);
488 	f2fs_bug_on(sbi, __is_valid_data_blkaddr(nat_get_blkaddr(e)) &&
489 			new_blkaddr == NEW_ADDR);
490 
491 	/* increment version no as node is removed */
492 	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
493 		unsigned char version = nat_get_version(e);
494 
495 		nat_set_version(e, inc_node_version(version));
496 	}
497 
498 	/* change address */
499 	nat_set_blkaddr(e, new_blkaddr);
500 	if (!__is_valid_data_blkaddr(new_blkaddr))
501 		set_nat_flag(e, IS_CHECKPOINTED, false);
502 	__set_nat_cache_dirty(nm_i, e);
503 
504 	/* update fsync_mark if its inode nat entry is still alive */
505 	if (ni->nid != ni->ino)
506 		e = __lookup_nat_cache(nm_i, ni->ino);
507 	if (e) {
508 		if (fsync_done && ni->nid == ni->ino)
509 			set_nat_flag(e, HAS_FSYNCED_INODE, true);
510 		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
511 	}
512 	f2fs_up_write(&nm_i->nat_tree_lock);
513 }
514 
515 int f2fs_try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
516 {
517 	struct f2fs_nm_info *nm_i = NM_I(sbi);
518 	int nr = nr_shrink;
519 
520 	if (!f2fs_down_write_trylock(&nm_i->nat_tree_lock))
521 		return 0;
522 
523 	spin_lock(&nm_i->nat_list_lock);
524 	while (nr_shrink) {
525 		struct nat_entry *ne;
526 
527 		if (list_empty(&nm_i->nat_entries))
528 			break;
529 
530 		ne = list_first_entry(&nm_i->nat_entries,
531 					struct nat_entry, list);
532 		list_del(&ne->list);
533 		spin_unlock(&nm_i->nat_list_lock);
534 
535 		__del_from_nat_cache(nm_i, ne);
536 		nr_shrink--;
537 
538 		spin_lock(&nm_i->nat_list_lock);
539 	}
540 	spin_unlock(&nm_i->nat_list_lock);
541 
542 	f2fs_up_write(&nm_i->nat_tree_lock);
543 	return nr - nr_shrink;
544 }
545 
546 int f2fs_get_node_info(struct f2fs_sb_info *sbi, nid_t nid,
547 				struct node_info *ni, bool checkpoint_context)
548 {
549 	struct f2fs_nm_info *nm_i = NM_I(sbi);
550 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
551 	struct f2fs_journal *journal = curseg->journal;
552 	nid_t start_nid = START_NID(nid);
553 	struct f2fs_nat_block *nat_blk;
554 	struct page *page = NULL;
555 	struct f2fs_nat_entry ne;
556 	struct nat_entry *e;
557 	pgoff_t index;
558 	block_t blkaddr;
559 	int i;
560 
561 	ni->nid = nid;
562 retry:
563 	/* Check nat cache */
564 	f2fs_down_read(&nm_i->nat_tree_lock);
565 	e = __lookup_nat_cache(nm_i, nid);
566 	if (e) {
567 		ni->ino = nat_get_ino(e);
568 		ni->blk_addr = nat_get_blkaddr(e);
569 		ni->version = nat_get_version(e);
570 		f2fs_up_read(&nm_i->nat_tree_lock);
571 		return 0;
572 	}
573 
574 	/*
575 	 * Check current segment summary by trying to grab journal_rwsem first.
576 	 * This sem is on the critical path on the checkpoint requiring the above
577 	 * nat_tree_lock. Therefore, we should retry, if we failed to grab here
578 	 * while not bothering checkpoint.
579 	 */
580 	if (!f2fs_rwsem_is_locked(&sbi->cp_global_sem) || checkpoint_context) {
581 		down_read(&curseg->journal_rwsem);
582 	} else if (f2fs_rwsem_is_contended(&nm_i->nat_tree_lock) ||
583 				!down_read_trylock(&curseg->journal_rwsem)) {
584 		f2fs_up_read(&nm_i->nat_tree_lock);
585 		goto retry;
586 	}
587 
588 	i = f2fs_lookup_journal_in_cursum(journal, NAT_JOURNAL, nid, 0);
589 	if (i >= 0) {
590 		ne = nat_in_journal(journal, i);
591 		node_info_from_raw_nat(ni, &ne);
592 	}
593 	up_read(&curseg->journal_rwsem);
594 	if (i >= 0) {
595 		f2fs_up_read(&nm_i->nat_tree_lock);
596 		goto cache;
597 	}
598 
599 	/* Fill node_info from nat page */
600 	index = current_nat_addr(sbi, nid);
601 	f2fs_up_read(&nm_i->nat_tree_lock);
602 
603 	page = f2fs_get_meta_page(sbi, index);
604 	if (IS_ERR(page))
605 		return PTR_ERR(page);
606 
607 	nat_blk = (struct f2fs_nat_block *)page_address(page);
608 	ne = nat_blk->entries[nid - start_nid];
609 	node_info_from_raw_nat(ni, &ne);
610 	f2fs_put_page(page, 1);
611 cache:
612 	blkaddr = le32_to_cpu(ne.block_addr);
613 	if (__is_valid_data_blkaddr(blkaddr) &&
614 		!f2fs_is_valid_blkaddr(sbi, blkaddr, DATA_GENERIC_ENHANCE))
615 		return -EFAULT;
616 
617 	/* cache nat entry */
618 	cache_nat_entry(sbi, nid, &ne);
619 	return 0;
620 }
621 
622 /*
623  * readahead MAX_RA_NODE number of node pages.
624  */
625 static void f2fs_ra_node_pages(struct page *parent, int start, int n)
626 {
627 	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
628 	struct blk_plug plug;
629 	int i, end;
630 	nid_t nid;
631 
632 	blk_start_plug(&plug);
633 
634 	/* Then, try readahead for siblings of the desired node */
635 	end = start + n;
636 	end = min(end, NIDS_PER_BLOCK);
637 	for (i = start; i < end; i++) {
638 		nid = get_nid(parent, i, false);
639 		f2fs_ra_node_page(sbi, nid);
640 	}
641 
642 	blk_finish_plug(&plug);
643 }
644 
645 pgoff_t f2fs_get_next_page_offset(struct dnode_of_data *dn, pgoff_t pgofs)
646 {
647 	const long direct_index = ADDRS_PER_INODE(dn->inode);
648 	const long direct_blks = ADDRS_PER_BLOCK(dn->inode);
649 	const long indirect_blks = ADDRS_PER_BLOCK(dn->inode) * NIDS_PER_BLOCK;
650 	unsigned int skipped_unit = ADDRS_PER_BLOCK(dn->inode);
651 	int cur_level = dn->cur_level;
652 	int max_level = dn->max_level;
653 	pgoff_t base = 0;
654 
655 	if (!dn->max_level)
656 		return pgofs + 1;
657 
658 	while (max_level-- > cur_level)
659 		skipped_unit *= NIDS_PER_BLOCK;
660 
661 	switch (dn->max_level) {
662 	case 3:
663 		base += 2 * indirect_blks;
664 		fallthrough;
665 	case 2:
666 		base += 2 * direct_blks;
667 		fallthrough;
668 	case 1:
669 		base += direct_index;
670 		break;
671 	default:
672 		f2fs_bug_on(F2FS_I_SB(dn->inode), 1);
673 	}
674 
675 	return ((pgofs - base) / skipped_unit + 1) * skipped_unit + base;
676 }
677 
678 /*
679  * The maximum depth is four.
680  * Offset[0] will have raw inode offset.
681  */
682 static int get_node_path(struct inode *inode, long block,
683 				int offset[4], unsigned int noffset[4])
684 {
685 	const long direct_index = ADDRS_PER_INODE(inode);
686 	const long direct_blks = ADDRS_PER_BLOCK(inode);
687 	const long dptrs_per_blk = NIDS_PER_BLOCK;
688 	const long indirect_blks = ADDRS_PER_BLOCK(inode) * NIDS_PER_BLOCK;
689 	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
690 	int n = 0;
691 	int level = 0;
692 
693 	noffset[0] = 0;
694 
695 	if (block < direct_index) {
696 		offset[n] = block;
697 		goto got;
698 	}
699 	block -= direct_index;
700 	if (block < direct_blks) {
701 		offset[n++] = NODE_DIR1_BLOCK;
702 		noffset[n] = 1;
703 		offset[n] = block;
704 		level = 1;
705 		goto got;
706 	}
707 	block -= direct_blks;
708 	if (block < direct_blks) {
709 		offset[n++] = NODE_DIR2_BLOCK;
710 		noffset[n] = 2;
711 		offset[n] = block;
712 		level = 1;
713 		goto got;
714 	}
715 	block -= direct_blks;
716 	if (block < indirect_blks) {
717 		offset[n++] = NODE_IND1_BLOCK;
718 		noffset[n] = 3;
719 		offset[n++] = block / direct_blks;
720 		noffset[n] = 4 + offset[n - 1];
721 		offset[n] = block % direct_blks;
722 		level = 2;
723 		goto got;
724 	}
725 	block -= indirect_blks;
726 	if (block < indirect_blks) {
727 		offset[n++] = NODE_IND2_BLOCK;
728 		noffset[n] = 4 + dptrs_per_blk;
729 		offset[n++] = block / direct_blks;
730 		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
731 		offset[n] = block % direct_blks;
732 		level = 2;
733 		goto got;
734 	}
735 	block -= indirect_blks;
736 	if (block < dindirect_blks) {
737 		offset[n++] = NODE_DIND_BLOCK;
738 		noffset[n] = 5 + (dptrs_per_blk * 2);
739 		offset[n++] = block / indirect_blks;
740 		noffset[n] = 6 + (dptrs_per_blk * 2) +
741 			      offset[n - 1] * (dptrs_per_blk + 1);
742 		offset[n++] = (block / direct_blks) % dptrs_per_blk;
743 		noffset[n] = 7 + (dptrs_per_blk * 2) +
744 			      offset[n - 2] * (dptrs_per_blk + 1) +
745 			      offset[n - 1];
746 		offset[n] = block % direct_blks;
747 		level = 3;
748 		goto got;
749 	} else {
750 		return -E2BIG;
751 	}
752 got:
753 	return level;
754 }
755 
756 /*
757  * Caller should call f2fs_put_dnode(dn).
758  * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
759  * f2fs_unlock_op() only if mode is set with ALLOC_NODE.
760  */
761 int f2fs_get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
762 {
763 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
764 	struct page *npage[4];
765 	struct page *parent = NULL;
766 	int offset[4];
767 	unsigned int noffset[4];
768 	nid_t nids[4];
769 	int level, i = 0;
770 	int err = 0;
771 
772 	level = get_node_path(dn->inode, index, offset, noffset);
773 	if (level < 0)
774 		return level;
775 
776 	nids[0] = dn->inode->i_ino;
777 	npage[0] = dn->inode_page;
778 
779 	if (!npage[0]) {
780 		npage[0] = f2fs_get_node_page(sbi, nids[0]);
781 		if (IS_ERR(npage[0]))
782 			return PTR_ERR(npage[0]);
783 	}
784 
785 	/* if inline_data is set, should not report any block indices */
786 	if (f2fs_has_inline_data(dn->inode) && index) {
787 		err = -ENOENT;
788 		f2fs_put_page(npage[0], 1);
789 		goto release_out;
790 	}
791 
792 	parent = npage[0];
793 	if (level != 0)
794 		nids[1] = get_nid(parent, offset[0], true);
795 	dn->inode_page = npage[0];
796 	dn->inode_page_locked = true;
797 
798 	/* get indirect or direct nodes */
799 	for (i = 1; i <= level; i++) {
800 		bool done = false;
801 
802 		if (!nids[i] && mode == ALLOC_NODE) {
803 			/* alloc new node */
804 			if (!f2fs_alloc_nid(sbi, &(nids[i]))) {
805 				err = -ENOSPC;
806 				goto release_pages;
807 			}
808 
809 			dn->nid = nids[i];
810 			npage[i] = f2fs_new_node_page(dn, noffset[i]);
811 			if (IS_ERR(npage[i])) {
812 				f2fs_alloc_nid_failed(sbi, nids[i]);
813 				err = PTR_ERR(npage[i]);
814 				goto release_pages;
815 			}
816 
817 			set_nid(parent, offset[i - 1], nids[i], i == 1);
818 			f2fs_alloc_nid_done(sbi, nids[i]);
819 			done = true;
820 		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
821 			npage[i] = f2fs_get_node_page_ra(parent, offset[i - 1]);
822 			if (IS_ERR(npage[i])) {
823 				err = PTR_ERR(npage[i]);
824 				goto release_pages;
825 			}
826 			done = true;
827 		}
828 		if (i == 1) {
829 			dn->inode_page_locked = false;
830 			unlock_page(parent);
831 		} else {
832 			f2fs_put_page(parent, 1);
833 		}
834 
835 		if (!done) {
836 			npage[i] = f2fs_get_node_page(sbi, nids[i]);
837 			if (IS_ERR(npage[i])) {
838 				err = PTR_ERR(npage[i]);
839 				f2fs_put_page(npage[0], 0);
840 				goto release_out;
841 			}
842 		}
843 		if (i < level) {
844 			parent = npage[i];
845 			nids[i + 1] = get_nid(parent, offset[i], false);
846 		}
847 	}
848 	dn->nid = nids[level];
849 	dn->ofs_in_node = offset[level];
850 	dn->node_page = npage[level];
851 	dn->data_blkaddr = f2fs_data_blkaddr(dn);
852 
853 	if (is_inode_flag_set(dn->inode, FI_COMPRESSED_FILE) &&
854 					f2fs_sb_has_readonly(sbi)) {
855 		unsigned int c_len = f2fs_cluster_blocks_are_contiguous(dn);
856 		block_t blkaddr;
857 
858 		if (!c_len)
859 			goto out;
860 
861 		blkaddr = f2fs_data_blkaddr(dn);
862 		if (blkaddr == COMPRESS_ADDR)
863 			blkaddr = data_blkaddr(dn->inode, dn->node_page,
864 						dn->ofs_in_node + 1);
865 
866 		f2fs_update_read_extent_tree_range_compressed(dn->inode,
867 					index, blkaddr,
868 					F2FS_I(dn->inode)->i_cluster_size,
869 					c_len);
870 	}
871 out:
872 	return 0;
873 
874 release_pages:
875 	f2fs_put_page(parent, 1);
876 	if (i > 1)
877 		f2fs_put_page(npage[0], 0);
878 release_out:
879 	dn->inode_page = NULL;
880 	dn->node_page = NULL;
881 	if (err == -ENOENT) {
882 		dn->cur_level = i;
883 		dn->max_level = level;
884 		dn->ofs_in_node = offset[level];
885 	}
886 	return err;
887 }
888 
889 static int truncate_node(struct dnode_of_data *dn)
890 {
891 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
892 	struct node_info ni;
893 	int err;
894 	pgoff_t index;
895 
896 	err = f2fs_get_node_info(sbi, dn->nid, &ni, false);
897 	if (err)
898 		return err;
899 
900 	/* Deallocate node address */
901 	f2fs_invalidate_blocks(sbi, ni.blk_addr);
902 	dec_valid_node_count(sbi, dn->inode, dn->nid == dn->inode->i_ino);
903 	set_node_addr(sbi, &ni, NULL_ADDR, false);
904 
905 	if (dn->nid == dn->inode->i_ino) {
906 		f2fs_remove_orphan_inode(sbi, dn->nid);
907 		dec_valid_inode_count(sbi);
908 		f2fs_inode_synced(dn->inode);
909 	}
910 
911 	clear_node_page_dirty(dn->node_page);
912 	set_sbi_flag(sbi, SBI_IS_DIRTY);
913 
914 	index = dn->node_page->index;
915 	f2fs_put_page(dn->node_page, 1);
916 
917 	invalidate_mapping_pages(NODE_MAPPING(sbi),
918 			index, index);
919 
920 	dn->node_page = NULL;
921 	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
922 
923 	return 0;
924 }
925 
926 static int truncate_dnode(struct dnode_of_data *dn)
927 {
928 	struct page *page;
929 	int err;
930 
931 	if (dn->nid == 0)
932 		return 1;
933 
934 	/* get direct node */
935 	page = f2fs_get_node_page(F2FS_I_SB(dn->inode), dn->nid);
936 	if (PTR_ERR(page) == -ENOENT)
937 		return 1;
938 	else if (IS_ERR(page))
939 		return PTR_ERR(page);
940 
941 	/* Make dnode_of_data for parameter */
942 	dn->node_page = page;
943 	dn->ofs_in_node = 0;
944 	f2fs_truncate_data_blocks(dn);
945 	err = truncate_node(dn);
946 	if (err)
947 		return err;
948 
949 	return 1;
950 }
951 
952 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
953 						int ofs, int depth)
954 {
955 	struct dnode_of_data rdn = *dn;
956 	struct page *page;
957 	struct f2fs_node *rn;
958 	nid_t child_nid;
959 	unsigned int child_nofs;
960 	int freed = 0;
961 	int i, ret;
962 
963 	if (dn->nid == 0)
964 		return NIDS_PER_BLOCK + 1;
965 
966 	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
967 
968 	page = f2fs_get_node_page(F2FS_I_SB(dn->inode), dn->nid);
969 	if (IS_ERR(page)) {
970 		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
971 		return PTR_ERR(page);
972 	}
973 
974 	f2fs_ra_node_pages(page, ofs, NIDS_PER_BLOCK);
975 
976 	rn = F2FS_NODE(page);
977 	if (depth < 3) {
978 		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
979 			child_nid = le32_to_cpu(rn->in.nid[i]);
980 			if (child_nid == 0)
981 				continue;
982 			rdn.nid = child_nid;
983 			ret = truncate_dnode(&rdn);
984 			if (ret < 0)
985 				goto out_err;
986 			if (set_nid(page, i, 0, false))
987 				dn->node_changed = true;
988 		}
989 	} else {
990 		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
991 		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
992 			child_nid = le32_to_cpu(rn->in.nid[i]);
993 			if (child_nid == 0) {
994 				child_nofs += NIDS_PER_BLOCK + 1;
995 				continue;
996 			}
997 			rdn.nid = child_nid;
998 			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
999 			if (ret == (NIDS_PER_BLOCK + 1)) {
1000 				if (set_nid(page, i, 0, false))
1001 					dn->node_changed = true;
1002 				child_nofs += ret;
1003 			} else if (ret < 0 && ret != -ENOENT) {
1004 				goto out_err;
1005 			}
1006 		}
1007 		freed = child_nofs;
1008 	}
1009 
1010 	if (!ofs) {
1011 		/* remove current indirect node */
1012 		dn->node_page = page;
1013 		ret = truncate_node(dn);
1014 		if (ret)
1015 			goto out_err;
1016 		freed++;
1017 	} else {
1018 		f2fs_put_page(page, 1);
1019 	}
1020 	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
1021 	return freed;
1022 
1023 out_err:
1024 	f2fs_put_page(page, 1);
1025 	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
1026 	return ret;
1027 }
1028 
1029 static int truncate_partial_nodes(struct dnode_of_data *dn,
1030 			struct f2fs_inode *ri, int *offset, int depth)
1031 {
1032 	struct page *pages[2];
1033 	nid_t nid[3];
1034 	nid_t child_nid;
1035 	int err = 0;
1036 	int i;
1037 	int idx = depth - 2;
1038 
1039 	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
1040 	if (!nid[0])
1041 		return 0;
1042 
1043 	/* get indirect nodes in the path */
1044 	for (i = 0; i < idx + 1; i++) {
1045 		/* reference count'll be increased */
1046 		pages[i] = f2fs_get_node_page(F2FS_I_SB(dn->inode), nid[i]);
1047 		if (IS_ERR(pages[i])) {
1048 			err = PTR_ERR(pages[i]);
1049 			idx = i - 1;
1050 			goto fail;
1051 		}
1052 		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
1053 	}
1054 
1055 	f2fs_ra_node_pages(pages[idx], offset[idx + 1], NIDS_PER_BLOCK);
1056 
1057 	/* free direct nodes linked to a partial indirect node */
1058 	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
1059 		child_nid = get_nid(pages[idx], i, false);
1060 		if (!child_nid)
1061 			continue;
1062 		dn->nid = child_nid;
1063 		err = truncate_dnode(dn);
1064 		if (err < 0)
1065 			goto fail;
1066 		if (set_nid(pages[idx], i, 0, false))
1067 			dn->node_changed = true;
1068 	}
1069 
1070 	if (offset[idx + 1] == 0) {
1071 		dn->node_page = pages[idx];
1072 		dn->nid = nid[idx];
1073 		err = truncate_node(dn);
1074 		if (err)
1075 			goto fail;
1076 	} else {
1077 		f2fs_put_page(pages[idx], 1);
1078 	}
1079 	offset[idx]++;
1080 	offset[idx + 1] = 0;
1081 	idx--;
1082 fail:
1083 	for (i = idx; i >= 0; i--)
1084 		f2fs_put_page(pages[i], 1);
1085 
1086 	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
1087 
1088 	return err;
1089 }
1090 
1091 /*
1092  * All the block addresses of data and nodes should be nullified.
1093  */
1094 int f2fs_truncate_inode_blocks(struct inode *inode, pgoff_t from)
1095 {
1096 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1097 	int err = 0, cont = 1;
1098 	int level, offset[4], noffset[4];
1099 	unsigned int nofs = 0;
1100 	struct f2fs_inode *ri;
1101 	struct dnode_of_data dn;
1102 	struct page *page;
1103 
1104 	trace_f2fs_truncate_inode_blocks_enter(inode, from);
1105 
1106 	level = get_node_path(inode, from, offset, noffset);
1107 	if (level < 0) {
1108 		trace_f2fs_truncate_inode_blocks_exit(inode, level);
1109 		return level;
1110 	}
1111 
1112 	page = f2fs_get_node_page(sbi, inode->i_ino);
1113 	if (IS_ERR(page)) {
1114 		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
1115 		return PTR_ERR(page);
1116 	}
1117 
1118 	set_new_dnode(&dn, inode, page, NULL, 0);
1119 	unlock_page(page);
1120 
1121 	ri = F2FS_INODE(page);
1122 	switch (level) {
1123 	case 0:
1124 	case 1:
1125 		nofs = noffset[1];
1126 		break;
1127 	case 2:
1128 		nofs = noffset[1];
1129 		if (!offset[level - 1])
1130 			goto skip_partial;
1131 		err = truncate_partial_nodes(&dn, ri, offset, level);
1132 		if (err < 0 && err != -ENOENT)
1133 			goto fail;
1134 		nofs += 1 + NIDS_PER_BLOCK;
1135 		break;
1136 	case 3:
1137 		nofs = 5 + 2 * NIDS_PER_BLOCK;
1138 		if (!offset[level - 1])
1139 			goto skip_partial;
1140 		err = truncate_partial_nodes(&dn, ri, offset, level);
1141 		if (err < 0 && err != -ENOENT)
1142 			goto fail;
1143 		break;
1144 	default:
1145 		BUG();
1146 	}
1147 
1148 skip_partial:
1149 	while (cont) {
1150 		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
1151 		switch (offset[0]) {
1152 		case NODE_DIR1_BLOCK:
1153 		case NODE_DIR2_BLOCK:
1154 			err = truncate_dnode(&dn);
1155 			break;
1156 
1157 		case NODE_IND1_BLOCK:
1158 		case NODE_IND2_BLOCK:
1159 			err = truncate_nodes(&dn, nofs, offset[1], 2);
1160 			break;
1161 
1162 		case NODE_DIND_BLOCK:
1163 			err = truncate_nodes(&dn, nofs, offset[1], 3);
1164 			cont = 0;
1165 			break;
1166 
1167 		default:
1168 			BUG();
1169 		}
1170 		if (err < 0 && err != -ENOENT)
1171 			goto fail;
1172 		if (offset[1] == 0 &&
1173 				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
1174 			lock_page(page);
1175 			BUG_ON(page->mapping != NODE_MAPPING(sbi));
1176 			f2fs_wait_on_page_writeback(page, NODE, true, true);
1177 			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
1178 			set_page_dirty(page);
1179 			unlock_page(page);
1180 		}
1181 		offset[1] = 0;
1182 		offset[0]++;
1183 		nofs += err;
1184 	}
1185 fail:
1186 	f2fs_put_page(page, 0);
1187 	trace_f2fs_truncate_inode_blocks_exit(inode, err);
1188 	return err > 0 ? 0 : err;
1189 }
1190 
1191 /* caller must lock inode page */
1192 int f2fs_truncate_xattr_node(struct inode *inode)
1193 {
1194 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1195 	nid_t nid = F2FS_I(inode)->i_xattr_nid;
1196 	struct dnode_of_data dn;
1197 	struct page *npage;
1198 	int err;
1199 
1200 	if (!nid)
1201 		return 0;
1202 
1203 	npage = f2fs_get_node_page(sbi, nid);
1204 	if (IS_ERR(npage))
1205 		return PTR_ERR(npage);
1206 
1207 	set_new_dnode(&dn, inode, NULL, npage, nid);
1208 	err = truncate_node(&dn);
1209 	if (err) {
1210 		f2fs_put_page(npage, 1);
1211 		return err;
1212 	}
1213 
1214 	f2fs_i_xnid_write(inode, 0);
1215 
1216 	return 0;
1217 }
1218 
1219 /*
1220  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
1221  * f2fs_unlock_op().
1222  */
1223 int f2fs_remove_inode_page(struct inode *inode)
1224 {
1225 	struct dnode_of_data dn;
1226 	int err;
1227 
1228 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
1229 	err = f2fs_get_dnode_of_data(&dn, 0, LOOKUP_NODE);
1230 	if (err)
1231 		return err;
1232 
1233 	err = f2fs_truncate_xattr_node(inode);
1234 	if (err) {
1235 		f2fs_put_dnode(&dn);
1236 		return err;
1237 	}
1238 
1239 	/* remove potential inline_data blocks */
1240 	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
1241 				S_ISLNK(inode->i_mode))
1242 		f2fs_truncate_data_blocks_range(&dn, 1);
1243 
1244 	/* 0 is possible, after f2fs_new_inode() has failed */
1245 	if (unlikely(f2fs_cp_error(F2FS_I_SB(inode)))) {
1246 		f2fs_put_dnode(&dn);
1247 		return -EIO;
1248 	}
1249 
1250 	if (unlikely(inode->i_blocks != 0 && inode->i_blocks != 8)) {
1251 		f2fs_warn(F2FS_I_SB(inode),
1252 			"f2fs_remove_inode_page: inconsistent i_blocks, ino:%lu, iblocks:%llu",
1253 			inode->i_ino, (unsigned long long)inode->i_blocks);
1254 		set_sbi_flag(F2FS_I_SB(inode), SBI_NEED_FSCK);
1255 	}
1256 
1257 	/* will put inode & node pages */
1258 	err = truncate_node(&dn);
1259 	if (err) {
1260 		f2fs_put_dnode(&dn);
1261 		return err;
1262 	}
1263 	return 0;
1264 }
1265 
1266 struct page *f2fs_new_inode_page(struct inode *inode)
1267 {
1268 	struct dnode_of_data dn;
1269 
1270 	/* allocate inode page for new inode */
1271 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
1272 
1273 	/* caller should f2fs_put_page(page, 1); */
1274 	return f2fs_new_node_page(&dn, 0);
1275 }
1276 
1277 struct page *f2fs_new_node_page(struct dnode_of_data *dn, unsigned int ofs)
1278 {
1279 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
1280 	struct node_info new_ni;
1281 	struct page *page;
1282 	int err;
1283 
1284 	if (unlikely(is_inode_flag_set(dn->inode, FI_NO_ALLOC)))
1285 		return ERR_PTR(-EPERM);
1286 
1287 	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), dn->nid, false);
1288 	if (!page)
1289 		return ERR_PTR(-ENOMEM);
1290 
1291 	if (unlikely((err = inc_valid_node_count(sbi, dn->inode, !ofs))))
1292 		goto fail;
1293 
1294 #ifdef CONFIG_F2FS_CHECK_FS
1295 	err = f2fs_get_node_info(sbi, dn->nid, &new_ni, false);
1296 	if (err) {
1297 		dec_valid_node_count(sbi, dn->inode, !ofs);
1298 		goto fail;
1299 	}
1300 	if (unlikely(new_ni.blk_addr != NULL_ADDR)) {
1301 		err = -EFSCORRUPTED;
1302 		set_sbi_flag(sbi, SBI_NEED_FSCK);
1303 		f2fs_handle_error(sbi, ERROR_INVALID_BLKADDR);
1304 		goto fail;
1305 	}
1306 #endif
1307 	new_ni.nid = dn->nid;
1308 	new_ni.ino = dn->inode->i_ino;
1309 	new_ni.blk_addr = NULL_ADDR;
1310 	new_ni.flag = 0;
1311 	new_ni.version = 0;
1312 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
1313 
1314 	f2fs_wait_on_page_writeback(page, NODE, true, true);
1315 	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
1316 	set_cold_node(page, S_ISDIR(dn->inode->i_mode));
1317 	if (!PageUptodate(page))
1318 		SetPageUptodate(page);
1319 	if (set_page_dirty(page))
1320 		dn->node_changed = true;
1321 
1322 	if (f2fs_has_xattr_block(ofs))
1323 		f2fs_i_xnid_write(dn->inode, dn->nid);
1324 
1325 	if (ofs == 0)
1326 		inc_valid_inode_count(sbi);
1327 	return page;
1328 
1329 fail:
1330 	clear_node_page_dirty(page);
1331 	f2fs_put_page(page, 1);
1332 	return ERR_PTR(err);
1333 }
1334 
1335 /*
1336  * Caller should do after getting the following values.
1337  * 0: f2fs_put_page(page, 0)
1338  * LOCKED_PAGE or error: f2fs_put_page(page, 1)
1339  */
1340 static int read_node_page(struct page *page, blk_opf_t op_flags)
1341 {
1342 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1343 	struct node_info ni;
1344 	struct f2fs_io_info fio = {
1345 		.sbi = sbi,
1346 		.type = NODE,
1347 		.op = REQ_OP_READ,
1348 		.op_flags = op_flags,
1349 		.page = page,
1350 		.encrypted_page = NULL,
1351 	};
1352 	int err;
1353 
1354 	if (PageUptodate(page)) {
1355 		if (!f2fs_inode_chksum_verify(sbi, page)) {
1356 			ClearPageUptodate(page);
1357 			return -EFSBADCRC;
1358 		}
1359 		return LOCKED_PAGE;
1360 	}
1361 
1362 	err = f2fs_get_node_info(sbi, page->index, &ni, false);
1363 	if (err)
1364 		return err;
1365 
1366 	/* NEW_ADDR can be seen, after cp_error drops some dirty node pages */
1367 	if (unlikely(ni.blk_addr == NULL_ADDR || ni.blk_addr == NEW_ADDR)) {
1368 		ClearPageUptodate(page);
1369 		return -ENOENT;
1370 	}
1371 
1372 	fio.new_blkaddr = fio.old_blkaddr = ni.blk_addr;
1373 
1374 	err = f2fs_submit_page_bio(&fio);
1375 
1376 	if (!err)
1377 		f2fs_update_iostat(sbi, NULL, FS_NODE_READ_IO, F2FS_BLKSIZE);
1378 
1379 	return err;
1380 }
1381 
1382 /*
1383  * Readahead a node page
1384  */
1385 void f2fs_ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
1386 {
1387 	struct page *apage;
1388 	int err;
1389 
1390 	if (!nid)
1391 		return;
1392 	if (f2fs_check_nid_range(sbi, nid))
1393 		return;
1394 
1395 	apage = xa_load(&NODE_MAPPING(sbi)->i_pages, nid);
1396 	if (apage)
1397 		return;
1398 
1399 	apage = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
1400 	if (!apage)
1401 		return;
1402 
1403 	err = read_node_page(apage, REQ_RAHEAD);
1404 	f2fs_put_page(apage, err ? 1 : 0);
1405 }
1406 
1407 static struct page *__get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid,
1408 					struct page *parent, int start)
1409 {
1410 	struct page *page;
1411 	int err;
1412 
1413 	if (!nid)
1414 		return ERR_PTR(-ENOENT);
1415 	if (f2fs_check_nid_range(sbi, nid))
1416 		return ERR_PTR(-EINVAL);
1417 repeat:
1418 	page = f2fs_grab_cache_page(NODE_MAPPING(sbi), nid, false);
1419 	if (!page)
1420 		return ERR_PTR(-ENOMEM);
1421 
1422 	err = read_node_page(page, 0);
1423 	if (err < 0) {
1424 		goto out_put_err;
1425 	} else if (err == LOCKED_PAGE) {
1426 		err = 0;
1427 		goto page_hit;
1428 	}
1429 
1430 	if (parent)
1431 		f2fs_ra_node_pages(parent, start + 1, MAX_RA_NODE);
1432 
1433 	lock_page(page);
1434 
1435 	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1436 		f2fs_put_page(page, 1);
1437 		goto repeat;
1438 	}
1439 
1440 	if (unlikely(!PageUptodate(page))) {
1441 		err = -EIO;
1442 		goto out_err;
1443 	}
1444 
1445 	if (!f2fs_inode_chksum_verify(sbi, page)) {
1446 		err = -EFSBADCRC;
1447 		goto out_err;
1448 	}
1449 page_hit:
1450 	if (likely(nid == nid_of_node(page)))
1451 		return page;
1452 
1453 	f2fs_warn(sbi, "inconsistent node block, nid:%lu, node_footer[nid:%u,ino:%u,ofs:%u,cpver:%llu,blkaddr:%u]",
1454 			  nid, nid_of_node(page), ino_of_node(page),
1455 			  ofs_of_node(page), cpver_of_node(page),
1456 			  next_blkaddr_of_node(page));
1457 	set_sbi_flag(sbi, SBI_NEED_FSCK);
1458 	err = -EINVAL;
1459 out_err:
1460 	ClearPageUptodate(page);
1461 out_put_err:
1462 	/* ENOENT comes from read_node_page which is not an error. */
1463 	if (err != -ENOENT)
1464 		f2fs_handle_page_eio(sbi, page->index, NODE);
1465 	f2fs_put_page(page, 1);
1466 	return ERR_PTR(err);
1467 }
1468 
1469 struct page *f2fs_get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
1470 {
1471 	return __get_node_page(sbi, nid, NULL, 0);
1472 }
1473 
1474 struct page *f2fs_get_node_page_ra(struct page *parent, int start)
1475 {
1476 	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
1477 	nid_t nid = get_nid(parent, start, false);
1478 
1479 	return __get_node_page(sbi, nid, parent, start);
1480 }
1481 
1482 static void flush_inline_data(struct f2fs_sb_info *sbi, nid_t ino)
1483 {
1484 	struct inode *inode;
1485 	struct page *page;
1486 	int ret;
1487 
1488 	/* should flush inline_data before evict_inode */
1489 	inode = ilookup(sbi->sb, ino);
1490 	if (!inode)
1491 		return;
1492 
1493 	page = f2fs_pagecache_get_page(inode->i_mapping, 0,
1494 					FGP_LOCK|FGP_NOWAIT, 0);
1495 	if (!page)
1496 		goto iput_out;
1497 
1498 	if (!PageUptodate(page))
1499 		goto page_out;
1500 
1501 	if (!PageDirty(page))
1502 		goto page_out;
1503 
1504 	if (!clear_page_dirty_for_io(page))
1505 		goto page_out;
1506 
1507 	ret = f2fs_write_inline_data(inode, page);
1508 	inode_dec_dirty_pages(inode);
1509 	f2fs_remove_dirty_inode(inode);
1510 	if (ret)
1511 		set_page_dirty(page);
1512 page_out:
1513 	f2fs_put_page(page, 1);
1514 iput_out:
1515 	iput(inode);
1516 }
1517 
1518 static struct page *last_fsync_dnode(struct f2fs_sb_info *sbi, nid_t ino)
1519 {
1520 	pgoff_t index;
1521 	struct pagevec pvec;
1522 	struct page *last_page = NULL;
1523 	int nr_pages;
1524 
1525 	pagevec_init(&pvec);
1526 	index = 0;
1527 
1528 	while ((nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1529 				PAGECACHE_TAG_DIRTY))) {
1530 		int i;
1531 
1532 		for (i = 0; i < nr_pages; i++) {
1533 			struct page *page = pvec.pages[i];
1534 
1535 			if (unlikely(f2fs_cp_error(sbi))) {
1536 				f2fs_put_page(last_page, 0);
1537 				pagevec_release(&pvec);
1538 				return ERR_PTR(-EIO);
1539 			}
1540 
1541 			if (!IS_DNODE(page) || !is_cold_node(page))
1542 				continue;
1543 			if (ino_of_node(page) != ino)
1544 				continue;
1545 
1546 			lock_page(page);
1547 
1548 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1549 continue_unlock:
1550 				unlock_page(page);
1551 				continue;
1552 			}
1553 			if (ino_of_node(page) != ino)
1554 				goto continue_unlock;
1555 
1556 			if (!PageDirty(page)) {
1557 				/* someone wrote it for us */
1558 				goto continue_unlock;
1559 			}
1560 
1561 			if (last_page)
1562 				f2fs_put_page(last_page, 0);
1563 
1564 			get_page(page);
1565 			last_page = page;
1566 			unlock_page(page);
1567 		}
1568 		pagevec_release(&pvec);
1569 		cond_resched();
1570 	}
1571 	return last_page;
1572 }
1573 
1574 static int __write_node_page(struct page *page, bool atomic, bool *submitted,
1575 				struct writeback_control *wbc, bool do_balance,
1576 				enum iostat_type io_type, unsigned int *seq_id)
1577 {
1578 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1579 	nid_t nid;
1580 	struct node_info ni;
1581 	struct f2fs_io_info fio = {
1582 		.sbi = sbi,
1583 		.ino = ino_of_node(page),
1584 		.type = NODE,
1585 		.op = REQ_OP_WRITE,
1586 		.op_flags = wbc_to_write_flags(wbc),
1587 		.page = page,
1588 		.encrypted_page = NULL,
1589 		.submitted = false,
1590 		.io_type = io_type,
1591 		.io_wbc = wbc,
1592 	};
1593 	unsigned int seq;
1594 
1595 	trace_f2fs_writepage(page, NODE);
1596 
1597 	if (unlikely(f2fs_cp_error(sbi))) {
1598 		ClearPageUptodate(page);
1599 		dec_page_count(sbi, F2FS_DIRTY_NODES);
1600 		unlock_page(page);
1601 		return 0;
1602 	}
1603 
1604 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
1605 		goto redirty_out;
1606 
1607 	if (!is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
1608 			wbc->sync_mode == WB_SYNC_NONE &&
1609 			IS_DNODE(page) && is_cold_node(page))
1610 		goto redirty_out;
1611 
1612 	/* get old block addr of this node page */
1613 	nid = nid_of_node(page);
1614 	f2fs_bug_on(sbi, page->index != nid);
1615 
1616 	if (f2fs_get_node_info(sbi, nid, &ni, !do_balance))
1617 		goto redirty_out;
1618 
1619 	if (wbc->for_reclaim) {
1620 		if (!f2fs_down_read_trylock(&sbi->node_write))
1621 			goto redirty_out;
1622 	} else {
1623 		f2fs_down_read(&sbi->node_write);
1624 	}
1625 
1626 	/* This page is already truncated */
1627 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
1628 		ClearPageUptodate(page);
1629 		dec_page_count(sbi, F2FS_DIRTY_NODES);
1630 		f2fs_up_read(&sbi->node_write);
1631 		unlock_page(page);
1632 		return 0;
1633 	}
1634 
1635 	if (__is_valid_data_blkaddr(ni.blk_addr) &&
1636 		!f2fs_is_valid_blkaddr(sbi, ni.blk_addr,
1637 					DATA_GENERIC_ENHANCE)) {
1638 		f2fs_up_read(&sbi->node_write);
1639 		goto redirty_out;
1640 	}
1641 
1642 	if (atomic && !test_opt(sbi, NOBARRIER) && !f2fs_sb_has_blkzoned(sbi))
1643 		fio.op_flags |= REQ_PREFLUSH | REQ_FUA;
1644 
1645 	/* should add to global list before clearing PAGECACHE status */
1646 	if (f2fs_in_warm_node_list(sbi, page)) {
1647 		seq = f2fs_add_fsync_node_entry(sbi, page);
1648 		if (seq_id)
1649 			*seq_id = seq;
1650 	}
1651 
1652 	set_page_writeback(page);
1653 	ClearPageError(page);
1654 
1655 	fio.old_blkaddr = ni.blk_addr;
1656 	f2fs_do_write_node_page(nid, &fio);
1657 	set_node_addr(sbi, &ni, fio.new_blkaddr, is_fsync_dnode(page));
1658 	dec_page_count(sbi, F2FS_DIRTY_NODES);
1659 	f2fs_up_read(&sbi->node_write);
1660 
1661 	if (wbc->for_reclaim) {
1662 		f2fs_submit_merged_write_cond(sbi, NULL, page, 0, NODE);
1663 		submitted = NULL;
1664 	}
1665 
1666 	unlock_page(page);
1667 
1668 	if (unlikely(f2fs_cp_error(sbi))) {
1669 		f2fs_submit_merged_write(sbi, NODE);
1670 		submitted = NULL;
1671 	}
1672 	if (submitted)
1673 		*submitted = fio.submitted;
1674 
1675 	if (do_balance)
1676 		f2fs_balance_fs(sbi, false);
1677 	return 0;
1678 
1679 redirty_out:
1680 	redirty_page_for_writepage(wbc, page);
1681 	return AOP_WRITEPAGE_ACTIVATE;
1682 }
1683 
1684 int f2fs_move_node_page(struct page *node_page, int gc_type)
1685 {
1686 	int err = 0;
1687 
1688 	if (gc_type == FG_GC) {
1689 		struct writeback_control wbc = {
1690 			.sync_mode = WB_SYNC_ALL,
1691 			.nr_to_write = 1,
1692 			.for_reclaim = 0,
1693 		};
1694 
1695 		f2fs_wait_on_page_writeback(node_page, NODE, true, true);
1696 
1697 		set_page_dirty(node_page);
1698 
1699 		if (!clear_page_dirty_for_io(node_page)) {
1700 			err = -EAGAIN;
1701 			goto out_page;
1702 		}
1703 
1704 		if (__write_node_page(node_page, false, NULL,
1705 					&wbc, false, FS_GC_NODE_IO, NULL)) {
1706 			err = -EAGAIN;
1707 			unlock_page(node_page);
1708 		}
1709 		goto release_page;
1710 	} else {
1711 		/* set page dirty and write it */
1712 		if (!PageWriteback(node_page))
1713 			set_page_dirty(node_page);
1714 	}
1715 out_page:
1716 	unlock_page(node_page);
1717 release_page:
1718 	f2fs_put_page(node_page, 0);
1719 	return err;
1720 }
1721 
1722 static int f2fs_write_node_page(struct page *page,
1723 				struct writeback_control *wbc)
1724 {
1725 	return __write_node_page(page, false, NULL, wbc, false,
1726 						FS_NODE_IO, NULL);
1727 }
1728 
1729 int f2fs_fsync_node_pages(struct f2fs_sb_info *sbi, struct inode *inode,
1730 			struct writeback_control *wbc, bool atomic,
1731 			unsigned int *seq_id)
1732 {
1733 	pgoff_t index;
1734 	struct pagevec pvec;
1735 	int ret = 0;
1736 	struct page *last_page = NULL;
1737 	bool marked = false;
1738 	nid_t ino = inode->i_ino;
1739 	int nr_pages;
1740 	int nwritten = 0;
1741 
1742 	if (atomic) {
1743 		last_page = last_fsync_dnode(sbi, ino);
1744 		if (IS_ERR_OR_NULL(last_page))
1745 			return PTR_ERR_OR_ZERO(last_page);
1746 	}
1747 retry:
1748 	pagevec_init(&pvec);
1749 	index = 0;
1750 
1751 	while ((nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1752 				PAGECACHE_TAG_DIRTY))) {
1753 		int i;
1754 
1755 		for (i = 0; i < nr_pages; i++) {
1756 			struct page *page = pvec.pages[i];
1757 			bool submitted = false;
1758 
1759 			if (unlikely(f2fs_cp_error(sbi))) {
1760 				f2fs_put_page(last_page, 0);
1761 				pagevec_release(&pvec);
1762 				ret = -EIO;
1763 				goto out;
1764 			}
1765 
1766 			if (!IS_DNODE(page) || !is_cold_node(page))
1767 				continue;
1768 			if (ino_of_node(page) != ino)
1769 				continue;
1770 
1771 			lock_page(page);
1772 
1773 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1774 continue_unlock:
1775 				unlock_page(page);
1776 				continue;
1777 			}
1778 			if (ino_of_node(page) != ino)
1779 				goto continue_unlock;
1780 
1781 			if (!PageDirty(page) && page != last_page) {
1782 				/* someone wrote it for us */
1783 				goto continue_unlock;
1784 			}
1785 
1786 			f2fs_wait_on_page_writeback(page, NODE, true, true);
1787 
1788 			set_fsync_mark(page, 0);
1789 			set_dentry_mark(page, 0);
1790 
1791 			if (!atomic || page == last_page) {
1792 				set_fsync_mark(page, 1);
1793 				percpu_counter_inc(&sbi->rf_node_block_count);
1794 				if (IS_INODE(page)) {
1795 					if (is_inode_flag_set(inode,
1796 								FI_DIRTY_INODE))
1797 						f2fs_update_inode(inode, page);
1798 					set_dentry_mark(page,
1799 						f2fs_need_dentry_mark(sbi, ino));
1800 				}
1801 				/* may be written by other thread */
1802 				if (!PageDirty(page))
1803 					set_page_dirty(page);
1804 			}
1805 
1806 			if (!clear_page_dirty_for_io(page))
1807 				goto continue_unlock;
1808 
1809 			ret = __write_node_page(page, atomic &&
1810 						page == last_page,
1811 						&submitted, wbc, true,
1812 						FS_NODE_IO, seq_id);
1813 			if (ret) {
1814 				unlock_page(page);
1815 				f2fs_put_page(last_page, 0);
1816 				break;
1817 			} else if (submitted) {
1818 				nwritten++;
1819 			}
1820 
1821 			if (page == last_page) {
1822 				f2fs_put_page(page, 0);
1823 				marked = true;
1824 				break;
1825 			}
1826 		}
1827 		pagevec_release(&pvec);
1828 		cond_resched();
1829 
1830 		if (ret || marked)
1831 			break;
1832 	}
1833 	if (!ret && atomic && !marked) {
1834 		f2fs_debug(sbi, "Retry to write fsync mark: ino=%u, idx=%lx",
1835 			   ino, last_page->index);
1836 		lock_page(last_page);
1837 		f2fs_wait_on_page_writeback(last_page, NODE, true, true);
1838 		set_page_dirty(last_page);
1839 		unlock_page(last_page);
1840 		goto retry;
1841 	}
1842 out:
1843 	if (nwritten)
1844 		f2fs_submit_merged_write_cond(sbi, NULL, NULL, ino, NODE);
1845 	return ret ? -EIO : 0;
1846 }
1847 
1848 static int f2fs_match_ino(struct inode *inode, unsigned long ino, void *data)
1849 {
1850 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1851 	bool clean;
1852 
1853 	if (inode->i_ino != ino)
1854 		return 0;
1855 
1856 	if (!is_inode_flag_set(inode, FI_DIRTY_INODE))
1857 		return 0;
1858 
1859 	spin_lock(&sbi->inode_lock[DIRTY_META]);
1860 	clean = list_empty(&F2FS_I(inode)->gdirty_list);
1861 	spin_unlock(&sbi->inode_lock[DIRTY_META]);
1862 
1863 	if (clean)
1864 		return 0;
1865 
1866 	inode = igrab(inode);
1867 	if (!inode)
1868 		return 0;
1869 	return 1;
1870 }
1871 
1872 static bool flush_dirty_inode(struct page *page)
1873 {
1874 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1875 	struct inode *inode;
1876 	nid_t ino = ino_of_node(page);
1877 
1878 	inode = find_inode_nowait(sbi->sb, ino, f2fs_match_ino, NULL);
1879 	if (!inode)
1880 		return false;
1881 
1882 	f2fs_update_inode(inode, page);
1883 	unlock_page(page);
1884 
1885 	iput(inode);
1886 	return true;
1887 }
1888 
1889 void f2fs_flush_inline_data(struct f2fs_sb_info *sbi)
1890 {
1891 	pgoff_t index = 0;
1892 	struct pagevec pvec;
1893 	int nr_pages;
1894 
1895 	pagevec_init(&pvec);
1896 
1897 	while ((nr_pages = pagevec_lookup_tag(&pvec,
1898 			NODE_MAPPING(sbi), &index, PAGECACHE_TAG_DIRTY))) {
1899 		int i;
1900 
1901 		for (i = 0; i < nr_pages; i++) {
1902 			struct page *page = pvec.pages[i];
1903 
1904 			if (!IS_DNODE(page))
1905 				continue;
1906 
1907 			lock_page(page);
1908 
1909 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1910 continue_unlock:
1911 				unlock_page(page);
1912 				continue;
1913 			}
1914 
1915 			if (!PageDirty(page)) {
1916 				/* someone wrote it for us */
1917 				goto continue_unlock;
1918 			}
1919 
1920 			/* flush inline_data, if it's async context. */
1921 			if (page_private_inline(page)) {
1922 				clear_page_private_inline(page);
1923 				unlock_page(page);
1924 				flush_inline_data(sbi, ino_of_node(page));
1925 				continue;
1926 			}
1927 			unlock_page(page);
1928 		}
1929 		pagevec_release(&pvec);
1930 		cond_resched();
1931 	}
1932 }
1933 
1934 int f2fs_sync_node_pages(struct f2fs_sb_info *sbi,
1935 				struct writeback_control *wbc,
1936 				bool do_balance, enum iostat_type io_type)
1937 {
1938 	pgoff_t index;
1939 	struct pagevec pvec;
1940 	int step = 0;
1941 	int nwritten = 0;
1942 	int ret = 0;
1943 	int nr_pages, done = 0;
1944 
1945 	pagevec_init(&pvec);
1946 
1947 next_step:
1948 	index = 0;
1949 
1950 	while (!done && (nr_pages = pagevec_lookup_tag(&pvec,
1951 			NODE_MAPPING(sbi), &index, PAGECACHE_TAG_DIRTY))) {
1952 		int i;
1953 
1954 		for (i = 0; i < nr_pages; i++) {
1955 			struct page *page = pvec.pages[i];
1956 			bool submitted = false;
1957 
1958 			/* give a priority to WB_SYNC threads */
1959 			if (atomic_read(&sbi->wb_sync_req[NODE]) &&
1960 					wbc->sync_mode == WB_SYNC_NONE) {
1961 				done = 1;
1962 				break;
1963 			}
1964 
1965 			/*
1966 			 * flushing sequence with step:
1967 			 * 0. indirect nodes
1968 			 * 1. dentry dnodes
1969 			 * 2. file dnodes
1970 			 */
1971 			if (step == 0 && IS_DNODE(page))
1972 				continue;
1973 			if (step == 1 && (!IS_DNODE(page) ||
1974 						is_cold_node(page)))
1975 				continue;
1976 			if (step == 2 && (!IS_DNODE(page) ||
1977 						!is_cold_node(page)))
1978 				continue;
1979 lock_node:
1980 			if (wbc->sync_mode == WB_SYNC_ALL)
1981 				lock_page(page);
1982 			else if (!trylock_page(page))
1983 				continue;
1984 
1985 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1986 continue_unlock:
1987 				unlock_page(page);
1988 				continue;
1989 			}
1990 
1991 			if (!PageDirty(page)) {
1992 				/* someone wrote it for us */
1993 				goto continue_unlock;
1994 			}
1995 
1996 			/* flush inline_data/inode, if it's async context. */
1997 			if (!do_balance)
1998 				goto write_node;
1999 
2000 			/* flush inline_data */
2001 			if (page_private_inline(page)) {
2002 				clear_page_private_inline(page);
2003 				unlock_page(page);
2004 				flush_inline_data(sbi, ino_of_node(page));
2005 				goto lock_node;
2006 			}
2007 
2008 			/* flush dirty inode */
2009 			if (IS_INODE(page) && flush_dirty_inode(page))
2010 				goto lock_node;
2011 write_node:
2012 			f2fs_wait_on_page_writeback(page, NODE, true, true);
2013 
2014 			if (!clear_page_dirty_for_io(page))
2015 				goto continue_unlock;
2016 
2017 			set_fsync_mark(page, 0);
2018 			set_dentry_mark(page, 0);
2019 
2020 			ret = __write_node_page(page, false, &submitted,
2021 						wbc, do_balance, io_type, NULL);
2022 			if (ret)
2023 				unlock_page(page);
2024 			else if (submitted)
2025 				nwritten++;
2026 
2027 			if (--wbc->nr_to_write == 0)
2028 				break;
2029 		}
2030 		pagevec_release(&pvec);
2031 		cond_resched();
2032 
2033 		if (wbc->nr_to_write == 0) {
2034 			step = 2;
2035 			break;
2036 		}
2037 	}
2038 
2039 	if (step < 2) {
2040 		if (!is_sbi_flag_set(sbi, SBI_CP_DISABLED) &&
2041 				wbc->sync_mode == WB_SYNC_NONE && step == 1)
2042 			goto out;
2043 		step++;
2044 		goto next_step;
2045 	}
2046 out:
2047 	if (nwritten)
2048 		f2fs_submit_merged_write(sbi, NODE);
2049 
2050 	if (unlikely(f2fs_cp_error(sbi)))
2051 		return -EIO;
2052 	return ret;
2053 }
2054 
2055 int f2fs_wait_on_node_pages_writeback(struct f2fs_sb_info *sbi,
2056 						unsigned int seq_id)
2057 {
2058 	struct fsync_node_entry *fn;
2059 	struct page *page;
2060 	struct list_head *head = &sbi->fsync_node_list;
2061 	unsigned long flags;
2062 	unsigned int cur_seq_id = 0;
2063 	int ret2, ret = 0;
2064 
2065 	while (seq_id && cur_seq_id < seq_id) {
2066 		spin_lock_irqsave(&sbi->fsync_node_lock, flags);
2067 		if (list_empty(head)) {
2068 			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
2069 			break;
2070 		}
2071 		fn = list_first_entry(head, struct fsync_node_entry, list);
2072 		if (fn->seq_id > seq_id) {
2073 			spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
2074 			break;
2075 		}
2076 		cur_seq_id = fn->seq_id;
2077 		page = fn->page;
2078 		get_page(page);
2079 		spin_unlock_irqrestore(&sbi->fsync_node_lock, flags);
2080 
2081 		f2fs_wait_on_page_writeback(page, NODE, true, false);
2082 		if (TestClearPageError(page))
2083 			ret = -EIO;
2084 
2085 		put_page(page);
2086 
2087 		if (ret)
2088 			break;
2089 	}
2090 
2091 	ret2 = filemap_check_errors(NODE_MAPPING(sbi));
2092 	if (!ret)
2093 		ret = ret2;
2094 
2095 	return ret;
2096 }
2097 
2098 static int f2fs_write_node_pages(struct address_space *mapping,
2099 			    struct writeback_control *wbc)
2100 {
2101 	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
2102 	struct blk_plug plug;
2103 	long diff;
2104 
2105 	if (unlikely(is_sbi_flag_set(sbi, SBI_POR_DOING)))
2106 		goto skip_write;
2107 
2108 	/* balancing f2fs's metadata in background */
2109 	f2fs_balance_fs_bg(sbi, true);
2110 
2111 	/* collect a number of dirty node pages and write together */
2112 	if (wbc->sync_mode != WB_SYNC_ALL &&
2113 			get_pages(sbi, F2FS_DIRTY_NODES) <
2114 					nr_pages_to_skip(sbi, NODE))
2115 		goto skip_write;
2116 
2117 	if (wbc->sync_mode == WB_SYNC_ALL)
2118 		atomic_inc(&sbi->wb_sync_req[NODE]);
2119 	else if (atomic_read(&sbi->wb_sync_req[NODE])) {
2120 		/* to avoid potential deadlock */
2121 		if (current->plug)
2122 			blk_finish_plug(current->plug);
2123 		goto skip_write;
2124 	}
2125 
2126 	trace_f2fs_writepages(mapping->host, wbc, NODE);
2127 
2128 	diff = nr_pages_to_write(sbi, NODE, wbc);
2129 	blk_start_plug(&plug);
2130 	f2fs_sync_node_pages(sbi, wbc, true, FS_NODE_IO);
2131 	blk_finish_plug(&plug);
2132 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
2133 
2134 	if (wbc->sync_mode == WB_SYNC_ALL)
2135 		atomic_dec(&sbi->wb_sync_req[NODE]);
2136 	return 0;
2137 
2138 skip_write:
2139 	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
2140 	trace_f2fs_writepages(mapping->host, wbc, NODE);
2141 	return 0;
2142 }
2143 
2144 static bool f2fs_dirty_node_folio(struct address_space *mapping,
2145 		struct folio *folio)
2146 {
2147 	trace_f2fs_set_page_dirty(&folio->page, NODE);
2148 
2149 	if (!folio_test_uptodate(folio))
2150 		folio_mark_uptodate(folio);
2151 #ifdef CONFIG_F2FS_CHECK_FS
2152 	if (IS_INODE(&folio->page))
2153 		f2fs_inode_chksum_set(F2FS_M_SB(mapping), &folio->page);
2154 #endif
2155 	if (filemap_dirty_folio(mapping, folio)) {
2156 		inc_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_NODES);
2157 		set_page_private_reference(&folio->page);
2158 		return true;
2159 	}
2160 	return false;
2161 }
2162 
2163 /*
2164  * Structure of the f2fs node operations
2165  */
2166 const struct address_space_operations f2fs_node_aops = {
2167 	.writepage	= f2fs_write_node_page,
2168 	.writepages	= f2fs_write_node_pages,
2169 	.dirty_folio	= f2fs_dirty_node_folio,
2170 	.invalidate_folio = f2fs_invalidate_folio,
2171 	.release_folio	= f2fs_release_folio,
2172 	.migrate_folio	= filemap_migrate_folio,
2173 };
2174 
2175 static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
2176 						nid_t n)
2177 {
2178 	return radix_tree_lookup(&nm_i->free_nid_root, n);
2179 }
2180 
2181 static int __insert_free_nid(struct f2fs_sb_info *sbi,
2182 				struct free_nid *i)
2183 {
2184 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2185 	int err = radix_tree_insert(&nm_i->free_nid_root, i->nid, i);
2186 
2187 	if (err)
2188 		return err;
2189 
2190 	nm_i->nid_cnt[FREE_NID]++;
2191 	list_add_tail(&i->list, &nm_i->free_nid_list);
2192 	return 0;
2193 }
2194 
2195 static void __remove_free_nid(struct f2fs_sb_info *sbi,
2196 			struct free_nid *i, enum nid_state state)
2197 {
2198 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2199 
2200 	f2fs_bug_on(sbi, state != i->state);
2201 	nm_i->nid_cnt[state]--;
2202 	if (state == FREE_NID)
2203 		list_del(&i->list);
2204 	radix_tree_delete(&nm_i->free_nid_root, i->nid);
2205 }
2206 
2207 static void __move_free_nid(struct f2fs_sb_info *sbi, struct free_nid *i,
2208 			enum nid_state org_state, enum nid_state dst_state)
2209 {
2210 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2211 
2212 	f2fs_bug_on(sbi, org_state != i->state);
2213 	i->state = dst_state;
2214 	nm_i->nid_cnt[org_state]--;
2215 	nm_i->nid_cnt[dst_state]++;
2216 
2217 	switch (dst_state) {
2218 	case PREALLOC_NID:
2219 		list_del(&i->list);
2220 		break;
2221 	case FREE_NID:
2222 		list_add_tail(&i->list, &nm_i->free_nid_list);
2223 		break;
2224 	default:
2225 		BUG_ON(1);
2226 	}
2227 }
2228 
2229 bool f2fs_nat_bitmap_enabled(struct f2fs_sb_info *sbi)
2230 {
2231 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2232 	unsigned int i;
2233 	bool ret = true;
2234 
2235 	f2fs_down_read(&nm_i->nat_tree_lock);
2236 	for (i = 0; i < nm_i->nat_blocks; i++) {
2237 		if (!test_bit_le(i, nm_i->nat_block_bitmap)) {
2238 			ret = false;
2239 			break;
2240 		}
2241 	}
2242 	f2fs_up_read(&nm_i->nat_tree_lock);
2243 
2244 	return ret;
2245 }
2246 
2247 static void update_free_nid_bitmap(struct f2fs_sb_info *sbi, nid_t nid,
2248 							bool set, bool build)
2249 {
2250 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2251 	unsigned int nat_ofs = NAT_BLOCK_OFFSET(nid);
2252 	unsigned int nid_ofs = nid - START_NID(nid);
2253 
2254 	if (!test_bit_le(nat_ofs, nm_i->nat_block_bitmap))
2255 		return;
2256 
2257 	if (set) {
2258 		if (test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
2259 			return;
2260 		__set_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
2261 		nm_i->free_nid_count[nat_ofs]++;
2262 	} else {
2263 		if (!test_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]))
2264 			return;
2265 		__clear_bit_le(nid_ofs, nm_i->free_nid_bitmap[nat_ofs]);
2266 		if (!build)
2267 			nm_i->free_nid_count[nat_ofs]--;
2268 	}
2269 }
2270 
2271 /* return if the nid is recognized as free */
2272 static bool add_free_nid(struct f2fs_sb_info *sbi,
2273 				nid_t nid, bool build, bool update)
2274 {
2275 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2276 	struct free_nid *i, *e;
2277 	struct nat_entry *ne;
2278 	int err = -EINVAL;
2279 	bool ret = false;
2280 
2281 	/* 0 nid should not be used */
2282 	if (unlikely(nid == 0))
2283 		return false;
2284 
2285 	if (unlikely(f2fs_check_nid_range(sbi, nid)))
2286 		return false;
2287 
2288 	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS, true, NULL);
2289 	i->nid = nid;
2290 	i->state = FREE_NID;
2291 
2292 	radix_tree_preload(GFP_NOFS | __GFP_NOFAIL);
2293 
2294 	spin_lock(&nm_i->nid_list_lock);
2295 
2296 	if (build) {
2297 		/*
2298 		 *   Thread A             Thread B
2299 		 *  - f2fs_create
2300 		 *   - f2fs_new_inode
2301 		 *    - f2fs_alloc_nid
2302 		 *     - __insert_nid_to_list(PREALLOC_NID)
2303 		 *                     - f2fs_balance_fs_bg
2304 		 *                      - f2fs_build_free_nids
2305 		 *                       - __f2fs_build_free_nids
2306 		 *                        - scan_nat_page
2307 		 *                         - add_free_nid
2308 		 *                          - __lookup_nat_cache
2309 		 *  - f2fs_add_link
2310 		 *   - f2fs_init_inode_metadata
2311 		 *    - f2fs_new_inode_page
2312 		 *     - f2fs_new_node_page
2313 		 *      - set_node_addr
2314 		 *  - f2fs_alloc_nid_done
2315 		 *   - __remove_nid_from_list(PREALLOC_NID)
2316 		 *                         - __insert_nid_to_list(FREE_NID)
2317 		 */
2318 		ne = __lookup_nat_cache(nm_i, nid);
2319 		if (ne && (!get_nat_flag(ne, IS_CHECKPOINTED) ||
2320 				nat_get_blkaddr(ne) != NULL_ADDR))
2321 			goto err_out;
2322 
2323 		e = __lookup_free_nid_list(nm_i, nid);
2324 		if (e) {
2325 			if (e->state == FREE_NID)
2326 				ret = true;
2327 			goto err_out;
2328 		}
2329 	}
2330 	ret = true;
2331 	err = __insert_free_nid(sbi, i);
2332 err_out:
2333 	if (update) {
2334 		update_free_nid_bitmap(sbi, nid, ret, build);
2335 		if (!build)
2336 			nm_i->available_nids++;
2337 	}
2338 	spin_unlock(&nm_i->nid_list_lock);
2339 	radix_tree_preload_end();
2340 
2341 	if (err)
2342 		kmem_cache_free(free_nid_slab, i);
2343 	return ret;
2344 }
2345 
2346 static void remove_free_nid(struct f2fs_sb_info *sbi, nid_t nid)
2347 {
2348 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2349 	struct free_nid *i;
2350 	bool need_free = false;
2351 
2352 	spin_lock(&nm_i->nid_list_lock);
2353 	i = __lookup_free_nid_list(nm_i, nid);
2354 	if (i && i->state == FREE_NID) {
2355 		__remove_free_nid(sbi, i, FREE_NID);
2356 		need_free = true;
2357 	}
2358 	spin_unlock(&nm_i->nid_list_lock);
2359 
2360 	if (need_free)
2361 		kmem_cache_free(free_nid_slab, i);
2362 }
2363 
2364 static int scan_nat_page(struct f2fs_sb_info *sbi,
2365 			struct page *nat_page, nid_t start_nid)
2366 {
2367 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2368 	struct f2fs_nat_block *nat_blk = page_address(nat_page);
2369 	block_t blk_addr;
2370 	unsigned int nat_ofs = NAT_BLOCK_OFFSET(start_nid);
2371 	int i;
2372 
2373 	__set_bit_le(nat_ofs, nm_i->nat_block_bitmap);
2374 
2375 	i = start_nid % NAT_ENTRY_PER_BLOCK;
2376 
2377 	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
2378 		if (unlikely(start_nid >= nm_i->max_nid))
2379 			break;
2380 
2381 		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
2382 
2383 		if (blk_addr == NEW_ADDR)
2384 			return -EINVAL;
2385 
2386 		if (blk_addr == NULL_ADDR) {
2387 			add_free_nid(sbi, start_nid, true, true);
2388 		} else {
2389 			spin_lock(&NM_I(sbi)->nid_list_lock);
2390 			update_free_nid_bitmap(sbi, start_nid, false, true);
2391 			spin_unlock(&NM_I(sbi)->nid_list_lock);
2392 		}
2393 	}
2394 
2395 	return 0;
2396 }
2397 
2398 static void scan_curseg_cache(struct f2fs_sb_info *sbi)
2399 {
2400 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
2401 	struct f2fs_journal *journal = curseg->journal;
2402 	int i;
2403 
2404 	down_read(&curseg->journal_rwsem);
2405 	for (i = 0; i < nats_in_cursum(journal); i++) {
2406 		block_t addr;
2407 		nid_t nid;
2408 
2409 		addr = le32_to_cpu(nat_in_journal(journal, i).block_addr);
2410 		nid = le32_to_cpu(nid_in_journal(journal, i));
2411 		if (addr == NULL_ADDR)
2412 			add_free_nid(sbi, nid, true, false);
2413 		else
2414 			remove_free_nid(sbi, nid);
2415 	}
2416 	up_read(&curseg->journal_rwsem);
2417 }
2418 
2419 static void scan_free_nid_bits(struct f2fs_sb_info *sbi)
2420 {
2421 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2422 	unsigned int i, idx;
2423 	nid_t nid;
2424 
2425 	f2fs_down_read(&nm_i->nat_tree_lock);
2426 
2427 	for (i = 0; i < nm_i->nat_blocks; i++) {
2428 		if (!test_bit_le(i, nm_i->nat_block_bitmap))
2429 			continue;
2430 		if (!nm_i->free_nid_count[i])
2431 			continue;
2432 		for (idx = 0; idx < NAT_ENTRY_PER_BLOCK; idx++) {
2433 			idx = find_next_bit_le(nm_i->free_nid_bitmap[i],
2434 						NAT_ENTRY_PER_BLOCK, idx);
2435 			if (idx >= NAT_ENTRY_PER_BLOCK)
2436 				break;
2437 
2438 			nid = i * NAT_ENTRY_PER_BLOCK + idx;
2439 			add_free_nid(sbi, nid, true, false);
2440 
2441 			if (nm_i->nid_cnt[FREE_NID] >= MAX_FREE_NIDS)
2442 				goto out;
2443 		}
2444 	}
2445 out:
2446 	scan_curseg_cache(sbi);
2447 
2448 	f2fs_up_read(&nm_i->nat_tree_lock);
2449 }
2450 
2451 static int __f2fs_build_free_nids(struct f2fs_sb_info *sbi,
2452 						bool sync, bool mount)
2453 {
2454 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2455 	int i = 0, ret;
2456 	nid_t nid = nm_i->next_scan_nid;
2457 
2458 	if (unlikely(nid >= nm_i->max_nid))
2459 		nid = 0;
2460 
2461 	if (unlikely(nid % NAT_ENTRY_PER_BLOCK))
2462 		nid = NAT_BLOCK_OFFSET(nid) * NAT_ENTRY_PER_BLOCK;
2463 
2464 	/* Enough entries */
2465 	if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
2466 		return 0;
2467 
2468 	if (!sync && !f2fs_available_free_memory(sbi, FREE_NIDS))
2469 		return 0;
2470 
2471 	if (!mount) {
2472 		/* try to find free nids in free_nid_bitmap */
2473 		scan_free_nid_bits(sbi);
2474 
2475 		if (nm_i->nid_cnt[FREE_NID] >= NAT_ENTRY_PER_BLOCK)
2476 			return 0;
2477 	}
2478 
2479 	/* readahead nat pages to be scanned */
2480 	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES,
2481 							META_NAT, true);
2482 
2483 	f2fs_down_read(&nm_i->nat_tree_lock);
2484 
2485 	while (1) {
2486 		if (!test_bit_le(NAT_BLOCK_OFFSET(nid),
2487 						nm_i->nat_block_bitmap)) {
2488 			struct page *page = get_current_nat_page(sbi, nid);
2489 
2490 			if (IS_ERR(page)) {
2491 				ret = PTR_ERR(page);
2492 			} else {
2493 				ret = scan_nat_page(sbi, page, nid);
2494 				f2fs_put_page(page, 1);
2495 			}
2496 
2497 			if (ret) {
2498 				f2fs_up_read(&nm_i->nat_tree_lock);
2499 				f2fs_err(sbi, "NAT is corrupt, run fsck to fix it");
2500 				return ret;
2501 			}
2502 		}
2503 
2504 		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
2505 		if (unlikely(nid >= nm_i->max_nid))
2506 			nid = 0;
2507 
2508 		if (++i >= FREE_NID_PAGES)
2509 			break;
2510 	}
2511 
2512 	/* go to the next free nat pages to find free nids abundantly */
2513 	nm_i->next_scan_nid = nid;
2514 
2515 	/* find free nids from current sum_pages */
2516 	scan_curseg_cache(sbi);
2517 
2518 	f2fs_up_read(&nm_i->nat_tree_lock);
2519 
2520 	f2fs_ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nm_i->next_scan_nid),
2521 					nm_i->ra_nid_pages, META_NAT, false);
2522 
2523 	return 0;
2524 }
2525 
2526 int f2fs_build_free_nids(struct f2fs_sb_info *sbi, bool sync, bool mount)
2527 {
2528 	int ret;
2529 
2530 	mutex_lock(&NM_I(sbi)->build_lock);
2531 	ret = __f2fs_build_free_nids(sbi, sync, mount);
2532 	mutex_unlock(&NM_I(sbi)->build_lock);
2533 
2534 	return ret;
2535 }
2536 
2537 /*
2538  * If this function returns success, caller can obtain a new nid
2539  * from second parameter of this function.
2540  * The returned nid could be used ino as well as nid when inode is created.
2541  */
2542 bool f2fs_alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
2543 {
2544 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2545 	struct free_nid *i = NULL;
2546 retry:
2547 	if (time_to_inject(sbi, FAULT_ALLOC_NID)) {
2548 		f2fs_show_injection_info(sbi, FAULT_ALLOC_NID);
2549 		return false;
2550 	}
2551 
2552 	spin_lock(&nm_i->nid_list_lock);
2553 
2554 	if (unlikely(nm_i->available_nids == 0)) {
2555 		spin_unlock(&nm_i->nid_list_lock);
2556 		return false;
2557 	}
2558 
2559 	/* We should not use stale free nids created by f2fs_build_free_nids */
2560 	if (nm_i->nid_cnt[FREE_NID] && !on_f2fs_build_free_nids(nm_i)) {
2561 		f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
2562 		i = list_first_entry(&nm_i->free_nid_list,
2563 					struct free_nid, list);
2564 		*nid = i->nid;
2565 
2566 		__move_free_nid(sbi, i, FREE_NID, PREALLOC_NID);
2567 		nm_i->available_nids--;
2568 
2569 		update_free_nid_bitmap(sbi, *nid, false, false);
2570 
2571 		spin_unlock(&nm_i->nid_list_lock);
2572 		return true;
2573 	}
2574 	spin_unlock(&nm_i->nid_list_lock);
2575 
2576 	/* Let's scan nat pages and its caches to get free nids */
2577 	if (!f2fs_build_free_nids(sbi, true, false))
2578 		goto retry;
2579 	return false;
2580 }
2581 
2582 /*
2583  * f2fs_alloc_nid() should be called prior to this function.
2584  */
2585 void f2fs_alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
2586 {
2587 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2588 	struct free_nid *i;
2589 
2590 	spin_lock(&nm_i->nid_list_lock);
2591 	i = __lookup_free_nid_list(nm_i, nid);
2592 	f2fs_bug_on(sbi, !i);
2593 	__remove_free_nid(sbi, i, PREALLOC_NID);
2594 	spin_unlock(&nm_i->nid_list_lock);
2595 
2596 	kmem_cache_free(free_nid_slab, i);
2597 }
2598 
2599 /*
2600  * f2fs_alloc_nid() should be called prior to this function.
2601  */
2602 void f2fs_alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
2603 {
2604 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2605 	struct free_nid *i;
2606 	bool need_free = false;
2607 
2608 	if (!nid)
2609 		return;
2610 
2611 	spin_lock(&nm_i->nid_list_lock);
2612 	i = __lookup_free_nid_list(nm_i, nid);
2613 	f2fs_bug_on(sbi, !i);
2614 
2615 	if (!f2fs_available_free_memory(sbi, FREE_NIDS)) {
2616 		__remove_free_nid(sbi, i, PREALLOC_NID);
2617 		need_free = true;
2618 	} else {
2619 		__move_free_nid(sbi, i, PREALLOC_NID, FREE_NID);
2620 	}
2621 
2622 	nm_i->available_nids++;
2623 
2624 	update_free_nid_bitmap(sbi, nid, true, false);
2625 
2626 	spin_unlock(&nm_i->nid_list_lock);
2627 
2628 	if (need_free)
2629 		kmem_cache_free(free_nid_slab, i);
2630 }
2631 
2632 int f2fs_try_to_free_nids(struct f2fs_sb_info *sbi, int nr_shrink)
2633 {
2634 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2635 	int nr = nr_shrink;
2636 
2637 	if (nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
2638 		return 0;
2639 
2640 	if (!mutex_trylock(&nm_i->build_lock))
2641 		return 0;
2642 
2643 	while (nr_shrink && nm_i->nid_cnt[FREE_NID] > MAX_FREE_NIDS) {
2644 		struct free_nid *i, *next;
2645 		unsigned int batch = SHRINK_NID_BATCH_SIZE;
2646 
2647 		spin_lock(&nm_i->nid_list_lock);
2648 		list_for_each_entry_safe(i, next, &nm_i->free_nid_list, list) {
2649 			if (!nr_shrink || !batch ||
2650 				nm_i->nid_cnt[FREE_NID] <= MAX_FREE_NIDS)
2651 				break;
2652 			__remove_free_nid(sbi, i, FREE_NID);
2653 			kmem_cache_free(free_nid_slab, i);
2654 			nr_shrink--;
2655 			batch--;
2656 		}
2657 		spin_unlock(&nm_i->nid_list_lock);
2658 	}
2659 
2660 	mutex_unlock(&nm_i->build_lock);
2661 
2662 	return nr - nr_shrink;
2663 }
2664 
2665 int f2fs_recover_inline_xattr(struct inode *inode, struct page *page)
2666 {
2667 	void *src_addr, *dst_addr;
2668 	size_t inline_size;
2669 	struct page *ipage;
2670 	struct f2fs_inode *ri;
2671 
2672 	ipage = f2fs_get_node_page(F2FS_I_SB(inode), inode->i_ino);
2673 	if (IS_ERR(ipage))
2674 		return PTR_ERR(ipage);
2675 
2676 	ri = F2FS_INODE(page);
2677 	if (ri->i_inline & F2FS_INLINE_XATTR) {
2678 		if (!f2fs_has_inline_xattr(inode)) {
2679 			set_inode_flag(inode, FI_INLINE_XATTR);
2680 			stat_inc_inline_xattr(inode);
2681 		}
2682 	} else {
2683 		if (f2fs_has_inline_xattr(inode)) {
2684 			stat_dec_inline_xattr(inode);
2685 			clear_inode_flag(inode, FI_INLINE_XATTR);
2686 		}
2687 		goto update_inode;
2688 	}
2689 
2690 	dst_addr = inline_xattr_addr(inode, ipage);
2691 	src_addr = inline_xattr_addr(inode, page);
2692 	inline_size = inline_xattr_size(inode);
2693 
2694 	f2fs_wait_on_page_writeback(ipage, NODE, true, true);
2695 	memcpy(dst_addr, src_addr, inline_size);
2696 update_inode:
2697 	f2fs_update_inode(inode, ipage);
2698 	f2fs_put_page(ipage, 1);
2699 	return 0;
2700 }
2701 
2702 int f2fs_recover_xattr_data(struct inode *inode, struct page *page)
2703 {
2704 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
2705 	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
2706 	nid_t new_xnid;
2707 	struct dnode_of_data dn;
2708 	struct node_info ni;
2709 	struct page *xpage;
2710 	int err;
2711 
2712 	if (!prev_xnid)
2713 		goto recover_xnid;
2714 
2715 	/* 1: invalidate the previous xattr nid */
2716 	err = f2fs_get_node_info(sbi, prev_xnid, &ni, false);
2717 	if (err)
2718 		return err;
2719 
2720 	f2fs_invalidate_blocks(sbi, ni.blk_addr);
2721 	dec_valid_node_count(sbi, inode, false);
2722 	set_node_addr(sbi, &ni, NULL_ADDR, false);
2723 
2724 recover_xnid:
2725 	/* 2: update xattr nid in inode */
2726 	if (!f2fs_alloc_nid(sbi, &new_xnid))
2727 		return -ENOSPC;
2728 
2729 	set_new_dnode(&dn, inode, NULL, NULL, new_xnid);
2730 	xpage = f2fs_new_node_page(&dn, XATTR_NODE_OFFSET);
2731 	if (IS_ERR(xpage)) {
2732 		f2fs_alloc_nid_failed(sbi, new_xnid);
2733 		return PTR_ERR(xpage);
2734 	}
2735 
2736 	f2fs_alloc_nid_done(sbi, new_xnid);
2737 	f2fs_update_inode_page(inode);
2738 
2739 	/* 3: update and set xattr node page dirty */
2740 	memcpy(F2FS_NODE(xpage), F2FS_NODE(page), VALID_XATTR_BLOCK_SIZE);
2741 
2742 	set_page_dirty(xpage);
2743 	f2fs_put_page(xpage, 1);
2744 
2745 	return 0;
2746 }
2747 
2748 int f2fs_recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
2749 {
2750 	struct f2fs_inode *src, *dst;
2751 	nid_t ino = ino_of_node(page);
2752 	struct node_info old_ni, new_ni;
2753 	struct page *ipage;
2754 	int err;
2755 
2756 	err = f2fs_get_node_info(sbi, ino, &old_ni, false);
2757 	if (err)
2758 		return err;
2759 
2760 	if (unlikely(old_ni.blk_addr != NULL_ADDR))
2761 		return -EINVAL;
2762 retry:
2763 	ipage = f2fs_grab_cache_page(NODE_MAPPING(sbi), ino, false);
2764 	if (!ipage) {
2765 		memalloc_retry_wait(GFP_NOFS);
2766 		goto retry;
2767 	}
2768 
2769 	/* Should not use this inode from free nid list */
2770 	remove_free_nid(sbi, ino);
2771 
2772 	if (!PageUptodate(ipage))
2773 		SetPageUptodate(ipage);
2774 	fill_node_footer(ipage, ino, ino, 0, true);
2775 	set_cold_node(ipage, false);
2776 
2777 	src = F2FS_INODE(page);
2778 	dst = F2FS_INODE(ipage);
2779 
2780 	memcpy(dst, src, offsetof(struct f2fs_inode, i_ext));
2781 	dst->i_size = 0;
2782 	dst->i_blocks = cpu_to_le64(1);
2783 	dst->i_links = cpu_to_le32(1);
2784 	dst->i_xattr_nid = 0;
2785 	dst->i_inline = src->i_inline & (F2FS_INLINE_XATTR | F2FS_EXTRA_ATTR);
2786 	if (dst->i_inline & F2FS_EXTRA_ATTR) {
2787 		dst->i_extra_isize = src->i_extra_isize;
2788 
2789 		if (f2fs_sb_has_flexible_inline_xattr(sbi) &&
2790 			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
2791 							i_inline_xattr_size))
2792 			dst->i_inline_xattr_size = src->i_inline_xattr_size;
2793 
2794 		if (f2fs_sb_has_project_quota(sbi) &&
2795 			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
2796 								i_projid))
2797 			dst->i_projid = src->i_projid;
2798 
2799 		if (f2fs_sb_has_inode_crtime(sbi) &&
2800 			F2FS_FITS_IN_INODE(src, le16_to_cpu(src->i_extra_isize),
2801 							i_crtime_nsec)) {
2802 			dst->i_crtime = src->i_crtime;
2803 			dst->i_crtime_nsec = src->i_crtime_nsec;
2804 		}
2805 	}
2806 
2807 	new_ni = old_ni;
2808 	new_ni.ino = ino;
2809 
2810 	if (unlikely(inc_valid_node_count(sbi, NULL, true)))
2811 		WARN_ON(1);
2812 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
2813 	inc_valid_inode_count(sbi);
2814 	set_page_dirty(ipage);
2815 	f2fs_put_page(ipage, 1);
2816 	return 0;
2817 }
2818 
2819 int f2fs_restore_node_summary(struct f2fs_sb_info *sbi,
2820 			unsigned int segno, struct f2fs_summary_block *sum)
2821 {
2822 	struct f2fs_node *rn;
2823 	struct f2fs_summary *sum_entry;
2824 	block_t addr;
2825 	int i, idx, last_offset, nrpages;
2826 
2827 	/* scan the node segment */
2828 	last_offset = sbi->blocks_per_seg;
2829 	addr = START_BLOCK(sbi, segno);
2830 	sum_entry = &sum->entries[0];
2831 
2832 	for (i = 0; i < last_offset; i += nrpages, addr += nrpages) {
2833 		nrpages = bio_max_segs(last_offset - i);
2834 
2835 		/* readahead node pages */
2836 		f2fs_ra_meta_pages(sbi, addr, nrpages, META_POR, true);
2837 
2838 		for (idx = addr; idx < addr + nrpages; idx++) {
2839 			struct page *page = f2fs_get_tmp_page(sbi, idx);
2840 
2841 			if (IS_ERR(page))
2842 				return PTR_ERR(page);
2843 
2844 			rn = F2FS_NODE(page);
2845 			sum_entry->nid = rn->footer.nid;
2846 			sum_entry->version = 0;
2847 			sum_entry->ofs_in_node = 0;
2848 			sum_entry++;
2849 			f2fs_put_page(page, 1);
2850 		}
2851 
2852 		invalidate_mapping_pages(META_MAPPING(sbi), addr,
2853 							addr + nrpages);
2854 	}
2855 	return 0;
2856 }
2857 
2858 static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
2859 {
2860 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2861 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
2862 	struct f2fs_journal *journal = curseg->journal;
2863 	int i;
2864 
2865 	down_write(&curseg->journal_rwsem);
2866 	for (i = 0; i < nats_in_cursum(journal); i++) {
2867 		struct nat_entry *ne;
2868 		struct f2fs_nat_entry raw_ne;
2869 		nid_t nid = le32_to_cpu(nid_in_journal(journal, i));
2870 
2871 		if (f2fs_check_nid_range(sbi, nid))
2872 			continue;
2873 
2874 		raw_ne = nat_in_journal(journal, i);
2875 
2876 		ne = __lookup_nat_cache(nm_i, nid);
2877 		if (!ne) {
2878 			ne = __alloc_nat_entry(sbi, nid, true);
2879 			__init_nat_entry(nm_i, ne, &raw_ne, true);
2880 		}
2881 
2882 		/*
2883 		 * if a free nat in journal has not been used after last
2884 		 * checkpoint, we should remove it from available nids,
2885 		 * since later we will add it again.
2886 		 */
2887 		if (!get_nat_flag(ne, IS_DIRTY) &&
2888 				le32_to_cpu(raw_ne.block_addr) == NULL_ADDR) {
2889 			spin_lock(&nm_i->nid_list_lock);
2890 			nm_i->available_nids--;
2891 			spin_unlock(&nm_i->nid_list_lock);
2892 		}
2893 
2894 		__set_nat_cache_dirty(nm_i, ne);
2895 	}
2896 	update_nats_in_cursum(journal, -i);
2897 	up_write(&curseg->journal_rwsem);
2898 }
2899 
2900 static void __adjust_nat_entry_set(struct nat_entry_set *nes,
2901 						struct list_head *head, int max)
2902 {
2903 	struct nat_entry_set *cur;
2904 
2905 	if (nes->entry_cnt >= max)
2906 		goto add_out;
2907 
2908 	list_for_each_entry(cur, head, set_list) {
2909 		if (cur->entry_cnt >= nes->entry_cnt) {
2910 			list_add(&nes->set_list, cur->set_list.prev);
2911 			return;
2912 		}
2913 	}
2914 add_out:
2915 	list_add_tail(&nes->set_list, head);
2916 }
2917 
2918 static void __update_nat_bits(struct f2fs_nm_info *nm_i, unsigned int nat_ofs,
2919 							unsigned int valid)
2920 {
2921 	if (valid == 0) {
2922 		__set_bit_le(nat_ofs, nm_i->empty_nat_bits);
2923 		__clear_bit_le(nat_ofs, nm_i->full_nat_bits);
2924 		return;
2925 	}
2926 
2927 	__clear_bit_le(nat_ofs, nm_i->empty_nat_bits);
2928 	if (valid == NAT_ENTRY_PER_BLOCK)
2929 		__set_bit_le(nat_ofs, nm_i->full_nat_bits);
2930 	else
2931 		__clear_bit_le(nat_ofs, nm_i->full_nat_bits);
2932 }
2933 
2934 static void update_nat_bits(struct f2fs_sb_info *sbi, nid_t start_nid,
2935 						struct page *page)
2936 {
2937 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2938 	unsigned int nat_index = start_nid / NAT_ENTRY_PER_BLOCK;
2939 	struct f2fs_nat_block *nat_blk = page_address(page);
2940 	int valid = 0;
2941 	int i = 0;
2942 
2943 	if (!is_set_ckpt_flags(sbi, CP_NAT_BITS_FLAG))
2944 		return;
2945 
2946 	if (nat_index == 0) {
2947 		valid = 1;
2948 		i = 1;
2949 	}
2950 	for (; i < NAT_ENTRY_PER_BLOCK; i++) {
2951 		if (le32_to_cpu(nat_blk->entries[i].block_addr) != NULL_ADDR)
2952 			valid++;
2953 	}
2954 
2955 	__update_nat_bits(nm_i, nat_index, valid);
2956 }
2957 
2958 void f2fs_enable_nat_bits(struct f2fs_sb_info *sbi)
2959 {
2960 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2961 	unsigned int nat_ofs;
2962 
2963 	f2fs_down_read(&nm_i->nat_tree_lock);
2964 
2965 	for (nat_ofs = 0; nat_ofs < nm_i->nat_blocks; nat_ofs++) {
2966 		unsigned int valid = 0, nid_ofs = 0;
2967 
2968 		/* handle nid zero due to it should never be used */
2969 		if (unlikely(nat_ofs == 0)) {
2970 			valid = 1;
2971 			nid_ofs = 1;
2972 		}
2973 
2974 		for (; nid_ofs < NAT_ENTRY_PER_BLOCK; nid_ofs++) {
2975 			if (!test_bit_le(nid_ofs,
2976 					nm_i->free_nid_bitmap[nat_ofs]))
2977 				valid++;
2978 		}
2979 
2980 		__update_nat_bits(nm_i, nat_ofs, valid);
2981 	}
2982 
2983 	f2fs_up_read(&nm_i->nat_tree_lock);
2984 }
2985 
2986 static int __flush_nat_entry_set(struct f2fs_sb_info *sbi,
2987 		struct nat_entry_set *set, struct cp_control *cpc)
2988 {
2989 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
2990 	struct f2fs_journal *journal = curseg->journal;
2991 	nid_t start_nid = set->set * NAT_ENTRY_PER_BLOCK;
2992 	bool to_journal = true;
2993 	struct f2fs_nat_block *nat_blk;
2994 	struct nat_entry *ne, *cur;
2995 	struct page *page = NULL;
2996 
2997 	/*
2998 	 * there are two steps to flush nat entries:
2999 	 * #1, flush nat entries to journal in current hot data summary block.
3000 	 * #2, flush nat entries to nat page.
3001 	 */
3002 	if ((cpc->reason & CP_UMOUNT) ||
3003 		!__has_cursum_space(journal, set->entry_cnt, NAT_JOURNAL))
3004 		to_journal = false;
3005 
3006 	if (to_journal) {
3007 		down_write(&curseg->journal_rwsem);
3008 	} else {
3009 		page = get_next_nat_page(sbi, start_nid);
3010 		if (IS_ERR(page))
3011 			return PTR_ERR(page);
3012 
3013 		nat_blk = page_address(page);
3014 		f2fs_bug_on(sbi, !nat_blk);
3015 	}
3016 
3017 	/* flush dirty nats in nat entry set */
3018 	list_for_each_entry_safe(ne, cur, &set->entry_list, list) {
3019 		struct f2fs_nat_entry *raw_ne;
3020 		nid_t nid = nat_get_nid(ne);
3021 		int offset;
3022 
3023 		f2fs_bug_on(sbi, nat_get_blkaddr(ne) == NEW_ADDR);
3024 
3025 		if (to_journal) {
3026 			offset = f2fs_lookup_journal_in_cursum(journal,
3027 							NAT_JOURNAL, nid, 1);
3028 			f2fs_bug_on(sbi, offset < 0);
3029 			raw_ne = &nat_in_journal(journal, offset);
3030 			nid_in_journal(journal, offset) = cpu_to_le32(nid);
3031 		} else {
3032 			raw_ne = &nat_blk->entries[nid - start_nid];
3033 		}
3034 		raw_nat_from_node_info(raw_ne, &ne->ni);
3035 		nat_reset_flag(ne);
3036 		__clear_nat_cache_dirty(NM_I(sbi), set, ne);
3037 		if (nat_get_blkaddr(ne) == NULL_ADDR) {
3038 			add_free_nid(sbi, nid, false, true);
3039 		} else {
3040 			spin_lock(&NM_I(sbi)->nid_list_lock);
3041 			update_free_nid_bitmap(sbi, nid, false, false);
3042 			spin_unlock(&NM_I(sbi)->nid_list_lock);
3043 		}
3044 	}
3045 
3046 	if (to_journal) {
3047 		up_write(&curseg->journal_rwsem);
3048 	} else {
3049 		update_nat_bits(sbi, start_nid, page);
3050 		f2fs_put_page(page, 1);
3051 	}
3052 
3053 	/* Allow dirty nats by node block allocation in write_begin */
3054 	if (!set->entry_cnt) {
3055 		radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
3056 		kmem_cache_free(nat_entry_set_slab, set);
3057 	}
3058 	return 0;
3059 }
3060 
3061 /*
3062  * This function is called during the checkpointing process.
3063  */
3064 int f2fs_flush_nat_entries(struct f2fs_sb_info *sbi, struct cp_control *cpc)
3065 {
3066 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3067 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
3068 	struct f2fs_journal *journal = curseg->journal;
3069 	struct nat_entry_set *setvec[SETVEC_SIZE];
3070 	struct nat_entry_set *set, *tmp;
3071 	unsigned int found;
3072 	nid_t set_idx = 0;
3073 	LIST_HEAD(sets);
3074 	int err = 0;
3075 
3076 	/*
3077 	 * during unmount, let's flush nat_bits before checking
3078 	 * nat_cnt[DIRTY_NAT].
3079 	 */
3080 	if (cpc->reason & CP_UMOUNT) {
3081 		f2fs_down_write(&nm_i->nat_tree_lock);
3082 		remove_nats_in_journal(sbi);
3083 		f2fs_up_write(&nm_i->nat_tree_lock);
3084 	}
3085 
3086 	if (!nm_i->nat_cnt[DIRTY_NAT])
3087 		return 0;
3088 
3089 	f2fs_down_write(&nm_i->nat_tree_lock);
3090 
3091 	/*
3092 	 * if there are no enough space in journal to store dirty nat
3093 	 * entries, remove all entries from journal and merge them
3094 	 * into nat entry set.
3095 	 */
3096 	if (cpc->reason & CP_UMOUNT ||
3097 		!__has_cursum_space(journal,
3098 			nm_i->nat_cnt[DIRTY_NAT], NAT_JOURNAL))
3099 		remove_nats_in_journal(sbi);
3100 
3101 	while ((found = __gang_lookup_nat_set(nm_i,
3102 					set_idx, SETVEC_SIZE, setvec))) {
3103 		unsigned idx;
3104 
3105 		set_idx = setvec[found - 1]->set + 1;
3106 		for (idx = 0; idx < found; idx++)
3107 			__adjust_nat_entry_set(setvec[idx], &sets,
3108 						MAX_NAT_JENTRIES(journal));
3109 	}
3110 
3111 	/* flush dirty nats in nat entry set */
3112 	list_for_each_entry_safe(set, tmp, &sets, set_list) {
3113 		err = __flush_nat_entry_set(sbi, set, cpc);
3114 		if (err)
3115 			break;
3116 	}
3117 
3118 	f2fs_up_write(&nm_i->nat_tree_lock);
3119 	/* Allow dirty nats by node block allocation in write_begin */
3120 
3121 	return err;
3122 }
3123 
3124 static int __get_nat_bitmaps(struct f2fs_sb_info *sbi)
3125 {
3126 	struct f2fs_checkpoint *ckpt = F2FS_CKPT(sbi);
3127 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3128 	unsigned int nat_bits_bytes = nm_i->nat_blocks / BITS_PER_BYTE;
3129 	unsigned int i;
3130 	__u64 cp_ver = cur_cp_version(ckpt);
3131 	block_t nat_bits_addr;
3132 
3133 	nm_i->nat_bits_blocks = F2FS_BLK_ALIGN((nat_bits_bytes << 1) + 8);
3134 	nm_i->nat_bits = f2fs_kvzalloc(sbi,
3135 			nm_i->nat_bits_blocks << F2FS_BLKSIZE_BITS, GFP_KERNEL);
3136 	if (!nm_i->nat_bits)
3137 		return -ENOMEM;
3138 
3139 	nm_i->full_nat_bits = nm_i->nat_bits + 8;
3140 	nm_i->empty_nat_bits = nm_i->full_nat_bits + nat_bits_bytes;
3141 
3142 	if (!is_set_ckpt_flags(sbi, CP_NAT_BITS_FLAG))
3143 		return 0;
3144 
3145 	nat_bits_addr = __start_cp_addr(sbi) + sbi->blocks_per_seg -
3146 						nm_i->nat_bits_blocks;
3147 	for (i = 0; i < nm_i->nat_bits_blocks; i++) {
3148 		struct page *page;
3149 
3150 		page = f2fs_get_meta_page(sbi, nat_bits_addr++);
3151 		if (IS_ERR(page))
3152 			return PTR_ERR(page);
3153 
3154 		memcpy(nm_i->nat_bits + (i << F2FS_BLKSIZE_BITS),
3155 					page_address(page), F2FS_BLKSIZE);
3156 		f2fs_put_page(page, 1);
3157 	}
3158 
3159 	cp_ver |= (cur_cp_crc(ckpt) << 32);
3160 	if (cpu_to_le64(cp_ver) != *(__le64 *)nm_i->nat_bits) {
3161 		clear_ckpt_flags(sbi, CP_NAT_BITS_FLAG);
3162 		f2fs_notice(sbi, "Disable nat_bits due to incorrect cp_ver (%llu, %llu)",
3163 			cp_ver, le64_to_cpu(*(__le64 *)nm_i->nat_bits));
3164 		return 0;
3165 	}
3166 
3167 	f2fs_notice(sbi, "Found nat_bits in checkpoint");
3168 	return 0;
3169 }
3170 
3171 static inline void load_free_nid_bitmap(struct f2fs_sb_info *sbi)
3172 {
3173 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3174 	unsigned int i = 0;
3175 	nid_t nid, last_nid;
3176 
3177 	if (!is_set_ckpt_flags(sbi, CP_NAT_BITS_FLAG))
3178 		return;
3179 
3180 	for (i = 0; i < nm_i->nat_blocks; i++) {
3181 		i = find_next_bit_le(nm_i->empty_nat_bits, nm_i->nat_blocks, i);
3182 		if (i >= nm_i->nat_blocks)
3183 			break;
3184 
3185 		__set_bit_le(i, nm_i->nat_block_bitmap);
3186 
3187 		nid = i * NAT_ENTRY_PER_BLOCK;
3188 		last_nid = nid + NAT_ENTRY_PER_BLOCK;
3189 
3190 		spin_lock(&NM_I(sbi)->nid_list_lock);
3191 		for (; nid < last_nid; nid++)
3192 			update_free_nid_bitmap(sbi, nid, true, true);
3193 		spin_unlock(&NM_I(sbi)->nid_list_lock);
3194 	}
3195 
3196 	for (i = 0; i < nm_i->nat_blocks; i++) {
3197 		i = find_next_bit_le(nm_i->full_nat_bits, nm_i->nat_blocks, i);
3198 		if (i >= nm_i->nat_blocks)
3199 			break;
3200 
3201 		__set_bit_le(i, nm_i->nat_block_bitmap);
3202 	}
3203 }
3204 
3205 static int init_node_manager(struct f2fs_sb_info *sbi)
3206 {
3207 	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
3208 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3209 	unsigned char *version_bitmap;
3210 	unsigned int nat_segs;
3211 	int err;
3212 
3213 	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
3214 
3215 	/* segment_count_nat includes pair segment so divide to 2. */
3216 	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
3217 	nm_i->nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
3218 	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nm_i->nat_blocks;
3219 
3220 	/* not used nids: 0, node, meta, (and root counted as valid node) */
3221 	nm_i->available_nids = nm_i->max_nid - sbi->total_valid_node_count -
3222 						F2FS_RESERVED_NODE_NUM;
3223 	nm_i->nid_cnt[FREE_NID] = 0;
3224 	nm_i->nid_cnt[PREALLOC_NID] = 0;
3225 	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
3226 	nm_i->ra_nid_pages = DEF_RA_NID_PAGES;
3227 	nm_i->dirty_nats_ratio = DEF_DIRTY_NAT_RATIO_THRESHOLD;
3228 	nm_i->max_rf_node_blocks = DEF_RF_NODE_BLOCKS;
3229 
3230 	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
3231 	INIT_LIST_HEAD(&nm_i->free_nid_list);
3232 	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);
3233 	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
3234 	INIT_LIST_HEAD(&nm_i->nat_entries);
3235 	spin_lock_init(&nm_i->nat_list_lock);
3236 
3237 	mutex_init(&nm_i->build_lock);
3238 	spin_lock_init(&nm_i->nid_list_lock);
3239 	init_f2fs_rwsem(&nm_i->nat_tree_lock);
3240 
3241 	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
3242 	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
3243 	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
3244 	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
3245 					GFP_KERNEL);
3246 	if (!nm_i->nat_bitmap)
3247 		return -ENOMEM;
3248 
3249 	err = __get_nat_bitmaps(sbi);
3250 	if (err)
3251 		return err;
3252 
3253 #ifdef CONFIG_F2FS_CHECK_FS
3254 	nm_i->nat_bitmap_mir = kmemdup(version_bitmap, nm_i->bitmap_size,
3255 					GFP_KERNEL);
3256 	if (!nm_i->nat_bitmap_mir)
3257 		return -ENOMEM;
3258 #endif
3259 
3260 	return 0;
3261 }
3262 
3263 static int init_free_nid_cache(struct f2fs_sb_info *sbi)
3264 {
3265 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3266 	int i;
3267 
3268 	nm_i->free_nid_bitmap =
3269 		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned char *),
3270 					      nm_i->nat_blocks),
3271 			      GFP_KERNEL);
3272 	if (!nm_i->free_nid_bitmap)
3273 		return -ENOMEM;
3274 
3275 	for (i = 0; i < nm_i->nat_blocks; i++) {
3276 		nm_i->free_nid_bitmap[i] = f2fs_kvzalloc(sbi,
3277 			f2fs_bitmap_size(NAT_ENTRY_PER_BLOCK), GFP_KERNEL);
3278 		if (!nm_i->free_nid_bitmap[i])
3279 			return -ENOMEM;
3280 	}
3281 
3282 	nm_i->nat_block_bitmap = f2fs_kvzalloc(sbi, nm_i->nat_blocks / 8,
3283 								GFP_KERNEL);
3284 	if (!nm_i->nat_block_bitmap)
3285 		return -ENOMEM;
3286 
3287 	nm_i->free_nid_count =
3288 		f2fs_kvzalloc(sbi, array_size(sizeof(unsigned short),
3289 					      nm_i->nat_blocks),
3290 			      GFP_KERNEL);
3291 	if (!nm_i->free_nid_count)
3292 		return -ENOMEM;
3293 	return 0;
3294 }
3295 
3296 int f2fs_build_node_manager(struct f2fs_sb_info *sbi)
3297 {
3298 	int err;
3299 
3300 	sbi->nm_info = f2fs_kzalloc(sbi, sizeof(struct f2fs_nm_info),
3301 							GFP_KERNEL);
3302 	if (!sbi->nm_info)
3303 		return -ENOMEM;
3304 
3305 	err = init_node_manager(sbi);
3306 	if (err)
3307 		return err;
3308 
3309 	err = init_free_nid_cache(sbi);
3310 	if (err)
3311 		return err;
3312 
3313 	/* load free nid status from nat_bits table */
3314 	load_free_nid_bitmap(sbi);
3315 
3316 	return f2fs_build_free_nids(sbi, true, true);
3317 }
3318 
3319 void f2fs_destroy_node_manager(struct f2fs_sb_info *sbi)
3320 {
3321 	struct f2fs_nm_info *nm_i = NM_I(sbi);
3322 	struct free_nid *i, *next_i;
3323 	struct nat_entry *natvec[NATVEC_SIZE];
3324 	struct nat_entry_set *setvec[SETVEC_SIZE];
3325 	nid_t nid = 0;
3326 	unsigned int found;
3327 
3328 	if (!nm_i)
3329 		return;
3330 
3331 	/* destroy free nid list */
3332 	spin_lock(&nm_i->nid_list_lock);
3333 	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
3334 		__remove_free_nid(sbi, i, FREE_NID);
3335 		spin_unlock(&nm_i->nid_list_lock);
3336 		kmem_cache_free(free_nid_slab, i);
3337 		spin_lock(&nm_i->nid_list_lock);
3338 	}
3339 	f2fs_bug_on(sbi, nm_i->nid_cnt[FREE_NID]);
3340 	f2fs_bug_on(sbi, nm_i->nid_cnt[PREALLOC_NID]);
3341 	f2fs_bug_on(sbi, !list_empty(&nm_i->free_nid_list));
3342 	spin_unlock(&nm_i->nid_list_lock);
3343 
3344 	/* destroy nat cache */
3345 	f2fs_down_write(&nm_i->nat_tree_lock);
3346 	while ((found = __gang_lookup_nat_cache(nm_i,
3347 					nid, NATVEC_SIZE, natvec))) {
3348 		unsigned idx;
3349 
3350 		nid = nat_get_nid(natvec[found - 1]) + 1;
3351 		for (idx = 0; idx < found; idx++) {
3352 			spin_lock(&nm_i->nat_list_lock);
3353 			list_del(&natvec[idx]->list);
3354 			spin_unlock(&nm_i->nat_list_lock);
3355 
3356 			__del_from_nat_cache(nm_i, natvec[idx]);
3357 		}
3358 	}
3359 	f2fs_bug_on(sbi, nm_i->nat_cnt[TOTAL_NAT]);
3360 
3361 	/* destroy nat set cache */
3362 	nid = 0;
3363 	while ((found = __gang_lookup_nat_set(nm_i,
3364 					nid, SETVEC_SIZE, setvec))) {
3365 		unsigned idx;
3366 
3367 		nid = setvec[found - 1]->set + 1;
3368 		for (idx = 0; idx < found; idx++) {
3369 			/* entry_cnt is not zero, when cp_error was occurred */
3370 			f2fs_bug_on(sbi, !list_empty(&setvec[idx]->entry_list));
3371 			radix_tree_delete(&nm_i->nat_set_root, setvec[idx]->set);
3372 			kmem_cache_free(nat_entry_set_slab, setvec[idx]);
3373 		}
3374 	}
3375 	f2fs_up_write(&nm_i->nat_tree_lock);
3376 
3377 	kvfree(nm_i->nat_block_bitmap);
3378 	if (nm_i->free_nid_bitmap) {
3379 		int i;
3380 
3381 		for (i = 0; i < nm_i->nat_blocks; i++)
3382 			kvfree(nm_i->free_nid_bitmap[i]);
3383 		kvfree(nm_i->free_nid_bitmap);
3384 	}
3385 	kvfree(nm_i->free_nid_count);
3386 
3387 	kvfree(nm_i->nat_bitmap);
3388 	kvfree(nm_i->nat_bits);
3389 #ifdef CONFIG_F2FS_CHECK_FS
3390 	kvfree(nm_i->nat_bitmap_mir);
3391 #endif
3392 	sbi->nm_info = NULL;
3393 	kfree(nm_i);
3394 }
3395 
3396 int __init f2fs_create_node_manager_caches(void)
3397 {
3398 	nat_entry_slab = f2fs_kmem_cache_create("f2fs_nat_entry",
3399 			sizeof(struct nat_entry));
3400 	if (!nat_entry_slab)
3401 		goto fail;
3402 
3403 	free_nid_slab = f2fs_kmem_cache_create("f2fs_free_nid",
3404 			sizeof(struct free_nid));
3405 	if (!free_nid_slab)
3406 		goto destroy_nat_entry;
3407 
3408 	nat_entry_set_slab = f2fs_kmem_cache_create("f2fs_nat_entry_set",
3409 			sizeof(struct nat_entry_set));
3410 	if (!nat_entry_set_slab)
3411 		goto destroy_free_nid;
3412 
3413 	fsync_node_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_node_entry",
3414 			sizeof(struct fsync_node_entry));
3415 	if (!fsync_node_entry_slab)
3416 		goto destroy_nat_entry_set;
3417 	return 0;
3418 
3419 destroy_nat_entry_set:
3420 	kmem_cache_destroy(nat_entry_set_slab);
3421 destroy_free_nid:
3422 	kmem_cache_destroy(free_nid_slab);
3423 destroy_nat_entry:
3424 	kmem_cache_destroy(nat_entry_slab);
3425 fail:
3426 	return -ENOMEM;
3427 }
3428 
3429 void f2fs_destroy_node_manager_caches(void)
3430 {
3431 	kmem_cache_destroy(fsync_node_entry_slab);
3432 	kmem_cache_destroy(nat_entry_set_slab);
3433 	kmem_cache_destroy(free_nid_slab);
3434 	kmem_cache_destroy(nat_entry_slab);
3435 }
3436