xref: /openbmc/linux/fs/f2fs/node.c (revision 769ec6e5b7d4a8115447736871be8bffaaba3a7d)
1 /*
2  * fs/f2fs/node.c
3  *
4  * Copyright (c) 2012 Samsung Electronics Co., Ltd.
5  *             http://www.samsung.com/
6  *
7  * This program is free software; you can redistribute it and/or modify
8  * it under the terms of the GNU General Public License version 2 as
9  * published by the Free Software Foundation.
10  */
11 #include <linux/fs.h>
12 #include <linux/f2fs_fs.h>
13 #include <linux/mpage.h>
14 #include <linux/backing-dev.h>
15 #include <linux/blkdev.h>
16 #include <linux/pagevec.h>
17 #include <linux/swap.h>
18 
19 #include "f2fs.h"
20 #include "node.h"
21 #include "segment.h"
22 #include <trace/events/f2fs.h>
23 
24 #define on_build_free_nids(nmi) mutex_is_locked(&nm_i->build_lock)
25 
26 static struct kmem_cache *nat_entry_slab;
27 static struct kmem_cache *free_nid_slab;
28 static struct kmem_cache *nat_entry_set_slab;
29 
30 bool available_free_memory(struct f2fs_sb_info *sbi, int type)
31 {
32 	struct f2fs_nm_info *nm_i = NM_I(sbi);
33 	struct sysinfo val;
34 	unsigned long avail_ram;
35 	unsigned long mem_size = 0;
36 	bool res = false;
37 
38 	si_meminfo(&val);
39 
40 	/* only uses low memory */
41 	avail_ram = val.totalram - val.totalhigh;
42 
43 	/* give 25%, 25%, 50%, 50% memory for each components respectively */
44 	if (type == FREE_NIDS) {
45 		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >>
46 							PAGE_CACHE_SHIFT;
47 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
48 	} else if (type == NAT_ENTRIES) {
49 		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >>
50 							PAGE_CACHE_SHIFT;
51 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 2);
52 	} else if (type == DIRTY_DENTS) {
53 		if (sbi->sb->s_bdi->dirty_exceeded)
54 			return false;
55 		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
56 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
57 	} else if (type == INO_ENTRIES) {
58 		int i;
59 
60 		if (sbi->sb->s_bdi->dirty_exceeded)
61 			return false;
62 		for (i = 0; i <= UPDATE_INO; i++)
63 			mem_size += (sbi->im[i].ino_num *
64 				sizeof(struct ino_entry)) >> PAGE_CACHE_SHIFT;
65 		res = mem_size < ((avail_ram * nm_i->ram_thresh / 100) >> 1);
66 	}
67 	return res;
68 }
69 
70 static void clear_node_page_dirty(struct page *page)
71 {
72 	struct address_space *mapping = page->mapping;
73 	unsigned int long flags;
74 
75 	if (PageDirty(page)) {
76 		spin_lock_irqsave(&mapping->tree_lock, flags);
77 		radix_tree_tag_clear(&mapping->page_tree,
78 				page_index(page),
79 				PAGECACHE_TAG_DIRTY);
80 		spin_unlock_irqrestore(&mapping->tree_lock, flags);
81 
82 		clear_page_dirty_for_io(page);
83 		dec_page_count(F2FS_M_SB(mapping), F2FS_DIRTY_NODES);
84 	}
85 	ClearPageUptodate(page);
86 }
87 
88 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
89 {
90 	pgoff_t index = current_nat_addr(sbi, nid);
91 	return get_meta_page(sbi, index);
92 }
93 
94 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
95 {
96 	struct page *src_page;
97 	struct page *dst_page;
98 	pgoff_t src_off;
99 	pgoff_t dst_off;
100 	void *src_addr;
101 	void *dst_addr;
102 	struct f2fs_nm_info *nm_i = NM_I(sbi);
103 
104 	src_off = current_nat_addr(sbi, nid);
105 	dst_off = next_nat_addr(sbi, src_off);
106 
107 	/* get current nat block page with lock */
108 	src_page = get_meta_page(sbi, src_off);
109 	dst_page = grab_meta_page(sbi, dst_off);
110 	f2fs_bug_on(sbi, PageDirty(src_page));
111 
112 	src_addr = page_address(src_page);
113 	dst_addr = page_address(dst_page);
114 	memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
115 	set_page_dirty(dst_page);
116 	f2fs_put_page(src_page, 1);
117 
118 	set_to_next_nat(nm_i, nid);
119 
120 	return dst_page;
121 }
122 
123 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
124 {
125 	return radix_tree_lookup(&nm_i->nat_root, n);
126 }
127 
128 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
129 		nid_t start, unsigned int nr, struct nat_entry **ep)
130 {
131 	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
132 }
133 
134 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
135 {
136 	list_del(&e->list);
137 	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
138 	nm_i->nat_cnt--;
139 	kmem_cache_free(nat_entry_slab, e);
140 }
141 
142 static void __set_nat_cache_dirty(struct f2fs_nm_info *nm_i,
143 						struct nat_entry *ne)
144 {
145 	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
146 	struct nat_entry_set *head;
147 
148 	if (get_nat_flag(ne, IS_DIRTY))
149 		return;
150 retry:
151 	head = radix_tree_lookup(&nm_i->nat_set_root, set);
152 	if (!head) {
153 		head = f2fs_kmem_cache_alloc(nat_entry_set_slab, GFP_ATOMIC);
154 
155 		INIT_LIST_HEAD(&head->entry_list);
156 		INIT_LIST_HEAD(&head->set_list);
157 		head->set = set;
158 		head->entry_cnt = 0;
159 
160 		if (radix_tree_insert(&nm_i->nat_set_root, set, head)) {
161 			kmem_cache_free(nat_entry_set_slab, head);
162 			goto retry;
163 		}
164 	}
165 	list_move_tail(&ne->list, &head->entry_list);
166 	nm_i->dirty_nat_cnt++;
167 	head->entry_cnt++;
168 	set_nat_flag(ne, IS_DIRTY, true);
169 }
170 
171 static void __clear_nat_cache_dirty(struct f2fs_nm_info *nm_i,
172 						struct nat_entry *ne)
173 {
174 	nid_t set = NAT_BLOCK_OFFSET(ne->ni.nid);
175 	struct nat_entry_set *head;
176 
177 	head = radix_tree_lookup(&nm_i->nat_set_root, set);
178 	if (head) {
179 		list_move_tail(&ne->list, &nm_i->nat_entries);
180 		set_nat_flag(ne, IS_DIRTY, false);
181 		head->entry_cnt--;
182 		nm_i->dirty_nat_cnt--;
183 	}
184 }
185 
186 static unsigned int __gang_lookup_nat_set(struct f2fs_nm_info *nm_i,
187 		nid_t start, unsigned int nr, struct nat_entry_set **ep)
188 {
189 	return radix_tree_gang_lookup(&nm_i->nat_set_root, (void **)ep,
190 							start, nr);
191 }
192 
193 bool is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
194 {
195 	struct f2fs_nm_info *nm_i = NM_I(sbi);
196 	struct nat_entry *e;
197 	bool is_cp = true;
198 
199 	down_read(&nm_i->nat_tree_lock);
200 	e = __lookup_nat_cache(nm_i, nid);
201 	if (e && !get_nat_flag(e, IS_CHECKPOINTED))
202 		is_cp = false;
203 	up_read(&nm_i->nat_tree_lock);
204 	return is_cp;
205 }
206 
207 bool has_fsynced_inode(struct f2fs_sb_info *sbi, nid_t ino)
208 {
209 	struct f2fs_nm_info *nm_i = NM_I(sbi);
210 	struct nat_entry *e;
211 	bool fsynced = false;
212 
213 	down_read(&nm_i->nat_tree_lock);
214 	e = __lookup_nat_cache(nm_i, ino);
215 	if (e && get_nat_flag(e, HAS_FSYNCED_INODE))
216 		fsynced = true;
217 	up_read(&nm_i->nat_tree_lock);
218 	return fsynced;
219 }
220 
221 bool need_inode_block_update(struct f2fs_sb_info *sbi, nid_t ino)
222 {
223 	struct f2fs_nm_info *nm_i = NM_I(sbi);
224 	struct nat_entry *e;
225 	bool need_update = true;
226 
227 	down_read(&nm_i->nat_tree_lock);
228 	e = __lookup_nat_cache(nm_i, ino);
229 	if (e && get_nat_flag(e, HAS_LAST_FSYNC) &&
230 			(get_nat_flag(e, IS_CHECKPOINTED) ||
231 			 get_nat_flag(e, HAS_FSYNCED_INODE)))
232 		need_update = false;
233 	up_read(&nm_i->nat_tree_lock);
234 	return need_update;
235 }
236 
237 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
238 {
239 	struct nat_entry *new;
240 
241 	new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
242 	if (!new)
243 		return NULL;
244 	if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
245 		kmem_cache_free(nat_entry_slab, new);
246 		return NULL;
247 	}
248 	memset(new, 0, sizeof(struct nat_entry));
249 	nat_set_nid(new, nid);
250 	nat_reset_flag(new);
251 	list_add_tail(&new->list, &nm_i->nat_entries);
252 	nm_i->nat_cnt++;
253 	return new;
254 }
255 
256 static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
257 						struct f2fs_nat_entry *ne)
258 {
259 	struct nat_entry *e;
260 retry:
261 	down_write(&nm_i->nat_tree_lock);
262 	e = __lookup_nat_cache(nm_i, nid);
263 	if (!e) {
264 		e = grab_nat_entry(nm_i, nid);
265 		if (!e) {
266 			up_write(&nm_i->nat_tree_lock);
267 			goto retry;
268 		}
269 		node_info_from_raw_nat(&e->ni, ne);
270 	}
271 	up_write(&nm_i->nat_tree_lock);
272 }
273 
274 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
275 			block_t new_blkaddr, bool fsync_done)
276 {
277 	struct f2fs_nm_info *nm_i = NM_I(sbi);
278 	struct nat_entry *e;
279 retry:
280 	down_write(&nm_i->nat_tree_lock);
281 	e = __lookup_nat_cache(nm_i, ni->nid);
282 	if (!e) {
283 		e = grab_nat_entry(nm_i, ni->nid);
284 		if (!e) {
285 			up_write(&nm_i->nat_tree_lock);
286 			goto retry;
287 		}
288 		e->ni = *ni;
289 		f2fs_bug_on(sbi, ni->blk_addr == NEW_ADDR);
290 	} else if (new_blkaddr == NEW_ADDR) {
291 		/*
292 		 * when nid is reallocated,
293 		 * previous nat entry can be remained in nat cache.
294 		 * So, reinitialize it with new information.
295 		 */
296 		e->ni = *ni;
297 		f2fs_bug_on(sbi, ni->blk_addr != NULL_ADDR);
298 	}
299 
300 	/* sanity check */
301 	f2fs_bug_on(sbi, nat_get_blkaddr(e) != ni->blk_addr);
302 	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NULL_ADDR &&
303 			new_blkaddr == NULL_ADDR);
304 	f2fs_bug_on(sbi, nat_get_blkaddr(e) == NEW_ADDR &&
305 			new_blkaddr == NEW_ADDR);
306 	f2fs_bug_on(sbi, nat_get_blkaddr(e) != NEW_ADDR &&
307 			nat_get_blkaddr(e) != NULL_ADDR &&
308 			new_blkaddr == NEW_ADDR);
309 
310 	/* increment version no as node is removed */
311 	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
312 		unsigned char version = nat_get_version(e);
313 		nat_set_version(e, inc_node_version(version));
314 	}
315 
316 	/* change address */
317 	nat_set_blkaddr(e, new_blkaddr);
318 	if (new_blkaddr == NEW_ADDR || new_blkaddr == NULL_ADDR)
319 		set_nat_flag(e, IS_CHECKPOINTED, false);
320 	__set_nat_cache_dirty(nm_i, e);
321 
322 	/* update fsync_mark if its inode nat entry is still alive */
323 	e = __lookup_nat_cache(nm_i, ni->ino);
324 	if (e) {
325 		if (fsync_done && ni->nid == ni->ino)
326 			set_nat_flag(e, HAS_FSYNCED_INODE, true);
327 		set_nat_flag(e, HAS_LAST_FSYNC, fsync_done);
328 	}
329 	up_write(&nm_i->nat_tree_lock);
330 }
331 
332 int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
333 {
334 	struct f2fs_nm_info *nm_i = NM_I(sbi);
335 
336 	if (available_free_memory(sbi, NAT_ENTRIES))
337 		return 0;
338 
339 	down_write(&nm_i->nat_tree_lock);
340 	while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
341 		struct nat_entry *ne;
342 		ne = list_first_entry(&nm_i->nat_entries,
343 					struct nat_entry, list);
344 		__del_from_nat_cache(nm_i, ne);
345 		nr_shrink--;
346 	}
347 	up_write(&nm_i->nat_tree_lock);
348 	return nr_shrink;
349 }
350 
351 /*
352  * This function always returns success
353  */
354 void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
355 {
356 	struct f2fs_nm_info *nm_i = NM_I(sbi);
357 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
358 	struct f2fs_summary_block *sum = curseg->sum_blk;
359 	nid_t start_nid = START_NID(nid);
360 	struct f2fs_nat_block *nat_blk;
361 	struct page *page = NULL;
362 	struct f2fs_nat_entry ne;
363 	struct nat_entry *e;
364 	int i;
365 
366 	memset(&ne, 0, sizeof(struct f2fs_nat_entry));
367 	ni->nid = nid;
368 
369 	/* Check nat cache */
370 	down_read(&nm_i->nat_tree_lock);
371 	e = __lookup_nat_cache(nm_i, nid);
372 	if (e) {
373 		ni->ino = nat_get_ino(e);
374 		ni->blk_addr = nat_get_blkaddr(e);
375 		ni->version = nat_get_version(e);
376 	}
377 	up_read(&nm_i->nat_tree_lock);
378 	if (e)
379 		return;
380 
381 	/* Check current segment summary */
382 	mutex_lock(&curseg->curseg_mutex);
383 	i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
384 	if (i >= 0) {
385 		ne = nat_in_journal(sum, i);
386 		node_info_from_raw_nat(ni, &ne);
387 	}
388 	mutex_unlock(&curseg->curseg_mutex);
389 	if (i >= 0)
390 		goto cache;
391 
392 	/* Fill node_info from nat page */
393 	page = get_current_nat_page(sbi, start_nid);
394 	nat_blk = (struct f2fs_nat_block *)page_address(page);
395 	ne = nat_blk->entries[nid - start_nid];
396 	node_info_from_raw_nat(ni, &ne);
397 	f2fs_put_page(page, 1);
398 cache:
399 	/* cache nat entry */
400 	cache_nat_entry(NM_I(sbi), nid, &ne);
401 }
402 
403 /*
404  * The maximum depth is four.
405  * Offset[0] will have raw inode offset.
406  */
407 static int get_node_path(struct f2fs_inode_info *fi, long block,
408 				int offset[4], unsigned int noffset[4])
409 {
410 	const long direct_index = ADDRS_PER_INODE(fi);
411 	const long direct_blks = ADDRS_PER_BLOCK;
412 	const long dptrs_per_blk = NIDS_PER_BLOCK;
413 	const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
414 	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
415 	int n = 0;
416 	int level = 0;
417 
418 	noffset[0] = 0;
419 
420 	if (block < direct_index) {
421 		offset[n] = block;
422 		goto got;
423 	}
424 	block -= direct_index;
425 	if (block < direct_blks) {
426 		offset[n++] = NODE_DIR1_BLOCK;
427 		noffset[n] = 1;
428 		offset[n] = block;
429 		level = 1;
430 		goto got;
431 	}
432 	block -= direct_blks;
433 	if (block < direct_blks) {
434 		offset[n++] = NODE_DIR2_BLOCK;
435 		noffset[n] = 2;
436 		offset[n] = block;
437 		level = 1;
438 		goto got;
439 	}
440 	block -= direct_blks;
441 	if (block < indirect_blks) {
442 		offset[n++] = NODE_IND1_BLOCK;
443 		noffset[n] = 3;
444 		offset[n++] = block / direct_blks;
445 		noffset[n] = 4 + offset[n - 1];
446 		offset[n] = block % direct_blks;
447 		level = 2;
448 		goto got;
449 	}
450 	block -= indirect_blks;
451 	if (block < indirect_blks) {
452 		offset[n++] = NODE_IND2_BLOCK;
453 		noffset[n] = 4 + dptrs_per_blk;
454 		offset[n++] = block / direct_blks;
455 		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
456 		offset[n] = block % direct_blks;
457 		level = 2;
458 		goto got;
459 	}
460 	block -= indirect_blks;
461 	if (block < dindirect_blks) {
462 		offset[n++] = NODE_DIND_BLOCK;
463 		noffset[n] = 5 + (dptrs_per_blk * 2);
464 		offset[n++] = block / indirect_blks;
465 		noffset[n] = 6 + (dptrs_per_blk * 2) +
466 			      offset[n - 1] * (dptrs_per_blk + 1);
467 		offset[n++] = (block / direct_blks) % dptrs_per_blk;
468 		noffset[n] = 7 + (dptrs_per_blk * 2) +
469 			      offset[n - 2] * (dptrs_per_blk + 1) +
470 			      offset[n - 1];
471 		offset[n] = block % direct_blks;
472 		level = 3;
473 		goto got;
474 	} else {
475 		BUG();
476 	}
477 got:
478 	return level;
479 }
480 
481 /*
482  * Caller should call f2fs_put_dnode(dn).
483  * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
484  * f2fs_unlock_op() only if ro is not set RDONLY_NODE.
485  * In the case of RDONLY_NODE, we don't need to care about mutex.
486  */
487 int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
488 {
489 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
490 	struct page *npage[4];
491 	struct page *parent;
492 	int offset[4];
493 	unsigned int noffset[4];
494 	nid_t nids[4];
495 	int level, i;
496 	int err = 0;
497 
498 	level = get_node_path(F2FS_I(dn->inode), index, offset, noffset);
499 
500 	nids[0] = dn->inode->i_ino;
501 	npage[0] = dn->inode_page;
502 
503 	if (!npage[0]) {
504 		npage[0] = get_node_page(sbi, nids[0]);
505 		if (IS_ERR(npage[0]))
506 			return PTR_ERR(npage[0]);
507 	}
508 	parent = npage[0];
509 	if (level != 0)
510 		nids[1] = get_nid(parent, offset[0], true);
511 	dn->inode_page = npage[0];
512 	dn->inode_page_locked = true;
513 
514 	/* get indirect or direct nodes */
515 	for (i = 1; i <= level; i++) {
516 		bool done = false;
517 
518 		if (!nids[i] && mode == ALLOC_NODE) {
519 			/* alloc new node */
520 			if (!alloc_nid(sbi, &(nids[i]))) {
521 				err = -ENOSPC;
522 				goto release_pages;
523 			}
524 
525 			dn->nid = nids[i];
526 			npage[i] = new_node_page(dn, noffset[i], NULL);
527 			if (IS_ERR(npage[i])) {
528 				alloc_nid_failed(sbi, nids[i]);
529 				err = PTR_ERR(npage[i]);
530 				goto release_pages;
531 			}
532 
533 			set_nid(parent, offset[i - 1], nids[i], i == 1);
534 			alloc_nid_done(sbi, nids[i]);
535 			done = true;
536 		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
537 			npage[i] = get_node_page_ra(parent, offset[i - 1]);
538 			if (IS_ERR(npage[i])) {
539 				err = PTR_ERR(npage[i]);
540 				goto release_pages;
541 			}
542 			done = true;
543 		}
544 		if (i == 1) {
545 			dn->inode_page_locked = false;
546 			unlock_page(parent);
547 		} else {
548 			f2fs_put_page(parent, 1);
549 		}
550 
551 		if (!done) {
552 			npage[i] = get_node_page(sbi, nids[i]);
553 			if (IS_ERR(npage[i])) {
554 				err = PTR_ERR(npage[i]);
555 				f2fs_put_page(npage[0], 0);
556 				goto release_out;
557 			}
558 		}
559 		if (i < level) {
560 			parent = npage[i];
561 			nids[i + 1] = get_nid(parent, offset[i], false);
562 		}
563 	}
564 	dn->nid = nids[level];
565 	dn->ofs_in_node = offset[level];
566 	dn->node_page = npage[level];
567 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
568 	return 0;
569 
570 release_pages:
571 	f2fs_put_page(parent, 1);
572 	if (i > 1)
573 		f2fs_put_page(npage[0], 0);
574 release_out:
575 	dn->inode_page = NULL;
576 	dn->node_page = NULL;
577 	return err;
578 }
579 
580 static void truncate_node(struct dnode_of_data *dn)
581 {
582 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
583 	struct node_info ni;
584 
585 	get_node_info(sbi, dn->nid, &ni);
586 	if (dn->inode->i_blocks == 0) {
587 		f2fs_bug_on(sbi, ni.blk_addr != NULL_ADDR);
588 		goto invalidate;
589 	}
590 	f2fs_bug_on(sbi, ni.blk_addr == NULL_ADDR);
591 
592 	/* Deallocate node address */
593 	invalidate_blocks(sbi, ni.blk_addr);
594 	dec_valid_node_count(sbi, dn->inode);
595 	set_node_addr(sbi, &ni, NULL_ADDR, false);
596 
597 	if (dn->nid == dn->inode->i_ino) {
598 		remove_orphan_inode(sbi, dn->nid);
599 		dec_valid_inode_count(sbi);
600 	} else {
601 		sync_inode_page(dn);
602 	}
603 invalidate:
604 	clear_node_page_dirty(dn->node_page);
605 	F2FS_SET_SB_DIRT(sbi);
606 
607 	f2fs_put_page(dn->node_page, 1);
608 
609 	invalidate_mapping_pages(NODE_MAPPING(sbi),
610 			dn->node_page->index, dn->node_page->index);
611 
612 	dn->node_page = NULL;
613 	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
614 }
615 
616 static int truncate_dnode(struct dnode_of_data *dn)
617 {
618 	struct page *page;
619 
620 	if (dn->nid == 0)
621 		return 1;
622 
623 	/* get direct node */
624 	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
625 	if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
626 		return 1;
627 	else if (IS_ERR(page))
628 		return PTR_ERR(page);
629 
630 	/* Make dnode_of_data for parameter */
631 	dn->node_page = page;
632 	dn->ofs_in_node = 0;
633 	truncate_data_blocks(dn);
634 	truncate_node(dn);
635 	return 1;
636 }
637 
638 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
639 						int ofs, int depth)
640 {
641 	struct dnode_of_data rdn = *dn;
642 	struct page *page;
643 	struct f2fs_node *rn;
644 	nid_t child_nid;
645 	unsigned int child_nofs;
646 	int freed = 0;
647 	int i, ret;
648 
649 	if (dn->nid == 0)
650 		return NIDS_PER_BLOCK + 1;
651 
652 	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
653 
654 	page = get_node_page(F2FS_I_SB(dn->inode), dn->nid);
655 	if (IS_ERR(page)) {
656 		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
657 		return PTR_ERR(page);
658 	}
659 
660 	rn = F2FS_NODE(page);
661 	if (depth < 3) {
662 		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
663 			child_nid = le32_to_cpu(rn->in.nid[i]);
664 			if (child_nid == 0)
665 				continue;
666 			rdn.nid = child_nid;
667 			ret = truncate_dnode(&rdn);
668 			if (ret < 0)
669 				goto out_err;
670 			set_nid(page, i, 0, false);
671 		}
672 	} else {
673 		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
674 		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
675 			child_nid = le32_to_cpu(rn->in.nid[i]);
676 			if (child_nid == 0) {
677 				child_nofs += NIDS_PER_BLOCK + 1;
678 				continue;
679 			}
680 			rdn.nid = child_nid;
681 			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
682 			if (ret == (NIDS_PER_BLOCK + 1)) {
683 				set_nid(page, i, 0, false);
684 				child_nofs += ret;
685 			} else if (ret < 0 && ret != -ENOENT) {
686 				goto out_err;
687 			}
688 		}
689 		freed = child_nofs;
690 	}
691 
692 	if (!ofs) {
693 		/* remove current indirect node */
694 		dn->node_page = page;
695 		truncate_node(dn);
696 		freed++;
697 	} else {
698 		f2fs_put_page(page, 1);
699 	}
700 	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
701 	return freed;
702 
703 out_err:
704 	f2fs_put_page(page, 1);
705 	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
706 	return ret;
707 }
708 
709 static int truncate_partial_nodes(struct dnode_of_data *dn,
710 			struct f2fs_inode *ri, int *offset, int depth)
711 {
712 	struct page *pages[2];
713 	nid_t nid[3];
714 	nid_t child_nid;
715 	int err = 0;
716 	int i;
717 	int idx = depth - 2;
718 
719 	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
720 	if (!nid[0])
721 		return 0;
722 
723 	/* get indirect nodes in the path */
724 	for (i = 0; i < idx + 1; i++) {
725 		/* reference count'll be increased */
726 		pages[i] = get_node_page(F2FS_I_SB(dn->inode), nid[i]);
727 		if (IS_ERR(pages[i])) {
728 			err = PTR_ERR(pages[i]);
729 			idx = i - 1;
730 			goto fail;
731 		}
732 		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
733 	}
734 
735 	/* free direct nodes linked to a partial indirect node */
736 	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
737 		child_nid = get_nid(pages[idx], i, false);
738 		if (!child_nid)
739 			continue;
740 		dn->nid = child_nid;
741 		err = truncate_dnode(dn);
742 		if (err < 0)
743 			goto fail;
744 		set_nid(pages[idx], i, 0, false);
745 	}
746 
747 	if (offset[idx + 1] == 0) {
748 		dn->node_page = pages[idx];
749 		dn->nid = nid[idx];
750 		truncate_node(dn);
751 	} else {
752 		f2fs_put_page(pages[idx], 1);
753 	}
754 	offset[idx]++;
755 	offset[idx + 1] = 0;
756 	idx--;
757 fail:
758 	for (i = idx; i >= 0; i--)
759 		f2fs_put_page(pages[i], 1);
760 
761 	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
762 
763 	return err;
764 }
765 
766 /*
767  * All the block addresses of data and nodes should be nullified.
768  */
769 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
770 {
771 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
772 	int err = 0, cont = 1;
773 	int level, offset[4], noffset[4];
774 	unsigned int nofs = 0;
775 	struct f2fs_inode *ri;
776 	struct dnode_of_data dn;
777 	struct page *page;
778 
779 	trace_f2fs_truncate_inode_blocks_enter(inode, from);
780 
781 	level = get_node_path(F2FS_I(inode), from, offset, noffset);
782 restart:
783 	page = get_node_page(sbi, inode->i_ino);
784 	if (IS_ERR(page)) {
785 		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
786 		return PTR_ERR(page);
787 	}
788 
789 	set_new_dnode(&dn, inode, page, NULL, 0);
790 	unlock_page(page);
791 
792 	ri = F2FS_INODE(page);
793 	switch (level) {
794 	case 0:
795 	case 1:
796 		nofs = noffset[1];
797 		break;
798 	case 2:
799 		nofs = noffset[1];
800 		if (!offset[level - 1])
801 			goto skip_partial;
802 		err = truncate_partial_nodes(&dn, ri, offset, level);
803 		if (err < 0 && err != -ENOENT)
804 			goto fail;
805 		nofs += 1 + NIDS_PER_BLOCK;
806 		break;
807 	case 3:
808 		nofs = 5 + 2 * NIDS_PER_BLOCK;
809 		if (!offset[level - 1])
810 			goto skip_partial;
811 		err = truncate_partial_nodes(&dn, ri, offset, level);
812 		if (err < 0 && err != -ENOENT)
813 			goto fail;
814 		break;
815 	default:
816 		BUG();
817 	}
818 
819 skip_partial:
820 	while (cont) {
821 		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
822 		switch (offset[0]) {
823 		case NODE_DIR1_BLOCK:
824 		case NODE_DIR2_BLOCK:
825 			err = truncate_dnode(&dn);
826 			break;
827 
828 		case NODE_IND1_BLOCK:
829 		case NODE_IND2_BLOCK:
830 			err = truncate_nodes(&dn, nofs, offset[1], 2);
831 			break;
832 
833 		case NODE_DIND_BLOCK:
834 			err = truncate_nodes(&dn, nofs, offset[1], 3);
835 			cont = 0;
836 			break;
837 
838 		default:
839 			BUG();
840 		}
841 		if (err < 0 && err != -ENOENT)
842 			goto fail;
843 		if (offset[1] == 0 &&
844 				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
845 			lock_page(page);
846 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
847 				f2fs_put_page(page, 1);
848 				goto restart;
849 			}
850 			f2fs_wait_on_page_writeback(page, NODE);
851 			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
852 			set_page_dirty(page);
853 			unlock_page(page);
854 		}
855 		offset[1] = 0;
856 		offset[0]++;
857 		nofs += err;
858 	}
859 fail:
860 	f2fs_put_page(page, 0);
861 	trace_f2fs_truncate_inode_blocks_exit(inode, err);
862 	return err > 0 ? 0 : err;
863 }
864 
865 int truncate_xattr_node(struct inode *inode, struct page *page)
866 {
867 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
868 	nid_t nid = F2FS_I(inode)->i_xattr_nid;
869 	struct dnode_of_data dn;
870 	struct page *npage;
871 
872 	if (!nid)
873 		return 0;
874 
875 	npage = get_node_page(sbi, nid);
876 	if (IS_ERR(npage))
877 		return PTR_ERR(npage);
878 
879 	F2FS_I(inode)->i_xattr_nid = 0;
880 
881 	/* need to do checkpoint during fsync */
882 	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
883 
884 	set_new_dnode(&dn, inode, page, npage, nid);
885 
886 	if (page)
887 		dn.inode_page_locked = true;
888 	truncate_node(&dn);
889 	return 0;
890 }
891 
892 /*
893  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
894  * f2fs_unlock_op().
895  */
896 void remove_inode_page(struct inode *inode)
897 {
898 	struct dnode_of_data dn;
899 
900 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
901 	if (get_dnode_of_data(&dn, 0, LOOKUP_NODE))
902 		return;
903 
904 	if (truncate_xattr_node(inode, dn.inode_page)) {
905 		f2fs_put_dnode(&dn);
906 		return;
907 	}
908 
909 	/* remove potential inline_data blocks */
910 	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
911 				S_ISLNK(inode->i_mode))
912 		truncate_data_blocks_range(&dn, 1);
913 
914 	/* 0 is possible, after f2fs_new_inode() has failed */
915 	f2fs_bug_on(F2FS_I_SB(inode),
916 			inode->i_blocks != 0 && inode->i_blocks != 1);
917 
918 	/* will put inode & node pages */
919 	truncate_node(&dn);
920 }
921 
922 struct page *new_inode_page(struct inode *inode)
923 {
924 	struct dnode_of_data dn;
925 
926 	/* allocate inode page for new inode */
927 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
928 
929 	/* caller should f2fs_put_page(page, 1); */
930 	return new_node_page(&dn, 0, NULL);
931 }
932 
933 struct page *new_node_page(struct dnode_of_data *dn,
934 				unsigned int ofs, struct page *ipage)
935 {
936 	struct f2fs_sb_info *sbi = F2FS_I_SB(dn->inode);
937 	struct node_info old_ni, new_ni;
938 	struct page *page;
939 	int err;
940 
941 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
942 		return ERR_PTR(-EPERM);
943 
944 	page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
945 	if (!page)
946 		return ERR_PTR(-ENOMEM);
947 
948 	if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
949 		err = -ENOSPC;
950 		goto fail;
951 	}
952 
953 	get_node_info(sbi, dn->nid, &old_ni);
954 
955 	/* Reinitialize old_ni with new node page */
956 	f2fs_bug_on(sbi, old_ni.blk_addr != NULL_ADDR);
957 	new_ni = old_ni;
958 	new_ni.ino = dn->inode->i_ino;
959 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
960 
961 	f2fs_wait_on_page_writeback(page, NODE);
962 	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
963 	set_cold_node(dn->inode, page);
964 	SetPageUptodate(page);
965 	set_page_dirty(page);
966 
967 	if (f2fs_has_xattr_block(ofs))
968 		F2FS_I(dn->inode)->i_xattr_nid = dn->nid;
969 
970 	dn->node_page = page;
971 	if (ipage)
972 		update_inode(dn->inode, ipage);
973 	else
974 		sync_inode_page(dn);
975 	if (ofs == 0)
976 		inc_valid_inode_count(sbi);
977 
978 	return page;
979 
980 fail:
981 	clear_node_page_dirty(page);
982 	f2fs_put_page(page, 1);
983 	return ERR_PTR(err);
984 }
985 
986 /*
987  * Caller should do after getting the following values.
988  * 0: f2fs_put_page(page, 0)
989  * LOCKED_PAGE: f2fs_put_page(page, 1)
990  * error: nothing
991  */
992 static int read_node_page(struct page *page, int rw)
993 {
994 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
995 	struct node_info ni;
996 
997 	get_node_info(sbi, page->index, &ni);
998 
999 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
1000 		f2fs_put_page(page, 1);
1001 		return -ENOENT;
1002 	}
1003 
1004 	if (PageUptodate(page))
1005 		return LOCKED_PAGE;
1006 
1007 	return f2fs_submit_page_bio(sbi, page, ni.blk_addr, rw);
1008 }
1009 
1010 /*
1011  * Readahead a node page
1012  */
1013 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
1014 {
1015 	struct page *apage;
1016 	int err;
1017 
1018 	apage = find_get_page(NODE_MAPPING(sbi), nid);
1019 	if (apage && PageUptodate(apage)) {
1020 		f2fs_put_page(apage, 0);
1021 		return;
1022 	}
1023 	f2fs_put_page(apage, 0);
1024 
1025 	apage = grab_cache_page(NODE_MAPPING(sbi), nid);
1026 	if (!apage)
1027 		return;
1028 
1029 	err = read_node_page(apage, READA);
1030 	if (err == 0)
1031 		f2fs_put_page(apage, 0);
1032 	else if (err == LOCKED_PAGE)
1033 		f2fs_put_page(apage, 1);
1034 }
1035 
1036 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
1037 {
1038 	struct page *page;
1039 	int err;
1040 repeat:
1041 	page = grab_cache_page(NODE_MAPPING(sbi), nid);
1042 	if (!page)
1043 		return ERR_PTR(-ENOMEM);
1044 
1045 	err = read_node_page(page, READ_SYNC);
1046 	if (err < 0)
1047 		return ERR_PTR(err);
1048 	else if (err == LOCKED_PAGE)
1049 		goto got_it;
1050 
1051 	lock_page(page);
1052 	if (unlikely(!PageUptodate(page) || nid != nid_of_node(page))) {
1053 		f2fs_put_page(page, 1);
1054 		return ERR_PTR(-EIO);
1055 	}
1056 	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1057 		f2fs_put_page(page, 1);
1058 		goto repeat;
1059 	}
1060 got_it:
1061 	return page;
1062 }
1063 
1064 /*
1065  * Return a locked page for the desired node page.
1066  * And, readahead MAX_RA_NODE number of node pages.
1067  */
1068 struct page *get_node_page_ra(struct page *parent, int start)
1069 {
1070 	struct f2fs_sb_info *sbi = F2FS_P_SB(parent);
1071 	struct blk_plug plug;
1072 	struct page *page;
1073 	int err, i, end;
1074 	nid_t nid;
1075 
1076 	/* First, try getting the desired direct node. */
1077 	nid = get_nid(parent, start, false);
1078 	if (!nid)
1079 		return ERR_PTR(-ENOENT);
1080 repeat:
1081 	page = grab_cache_page(NODE_MAPPING(sbi), nid);
1082 	if (!page)
1083 		return ERR_PTR(-ENOMEM);
1084 
1085 	err = read_node_page(page, READ_SYNC);
1086 	if (err < 0)
1087 		return ERR_PTR(err);
1088 	else if (err == LOCKED_PAGE)
1089 		goto page_hit;
1090 
1091 	blk_start_plug(&plug);
1092 
1093 	/* Then, try readahead for siblings of the desired node */
1094 	end = start + MAX_RA_NODE;
1095 	end = min(end, NIDS_PER_BLOCK);
1096 	for (i = start + 1; i < end; i++) {
1097 		nid = get_nid(parent, i, false);
1098 		if (!nid)
1099 			continue;
1100 		ra_node_page(sbi, nid);
1101 	}
1102 
1103 	blk_finish_plug(&plug);
1104 
1105 	lock_page(page);
1106 	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1107 		f2fs_put_page(page, 1);
1108 		goto repeat;
1109 	}
1110 page_hit:
1111 	if (unlikely(!PageUptodate(page))) {
1112 		f2fs_put_page(page, 1);
1113 		return ERR_PTR(-EIO);
1114 	}
1115 	return page;
1116 }
1117 
1118 void sync_inode_page(struct dnode_of_data *dn)
1119 {
1120 	if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
1121 		update_inode(dn->inode, dn->node_page);
1122 	} else if (dn->inode_page) {
1123 		if (!dn->inode_page_locked)
1124 			lock_page(dn->inode_page);
1125 		update_inode(dn->inode, dn->inode_page);
1126 		if (!dn->inode_page_locked)
1127 			unlock_page(dn->inode_page);
1128 	} else {
1129 		update_inode_page(dn->inode);
1130 	}
1131 }
1132 
1133 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
1134 					struct writeback_control *wbc)
1135 {
1136 	pgoff_t index, end;
1137 	struct pagevec pvec;
1138 	int step = ino ? 2 : 0;
1139 	int nwritten = 0, wrote = 0;
1140 
1141 	pagevec_init(&pvec, 0);
1142 
1143 next_step:
1144 	index = 0;
1145 	end = LONG_MAX;
1146 
1147 	while (index <= end) {
1148 		int i, nr_pages;
1149 		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1150 				PAGECACHE_TAG_DIRTY,
1151 				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1152 		if (nr_pages == 0)
1153 			break;
1154 
1155 		for (i = 0; i < nr_pages; i++) {
1156 			struct page *page = pvec.pages[i];
1157 
1158 			/*
1159 			 * flushing sequence with step:
1160 			 * 0. indirect nodes
1161 			 * 1. dentry dnodes
1162 			 * 2. file dnodes
1163 			 */
1164 			if (step == 0 && IS_DNODE(page))
1165 				continue;
1166 			if (step == 1 && (!IS_DNODE(page) ||
1167 						is_cold_node(page)))
1168 				continue;
1169 			if (step == 2 && (!IS_DNODE(page) ||
1170 						!is_cold_node(page)))
1171 				continue;
1172 
1173 			/*
1174 			 * If an fsync mode,
1175 			 * we should not skip writing node pages.
1176 			 */
1177 			if (ino && ino_of_node(page) == ino)
1178 				lock_page(page);
1179 			else if (!trylock_page(page))
1180 				continue;
1181 
1182 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1183 continue_unlock:
1184 				unlock_page(page);
1185 				continue;
1186 			}
1187 			if (ino && ino_of_node(page) != ino)
1188 				goto continue_unlock;
1189 
1190 			if (!PageDirty(page)) {
1191 				/* someone wrote it for us */
1192 				goto continue_unlock;
1193 			}
1194 
1195 			if (!clear_page_dirty_for_io(page))
1196 				goto continue_unlock;
1197 
1198 			/* called by fsync() */
1199 			if (ino && IS_DNODE(page)) {
1200 				set_fsync_mark(page, 1);
1201 				if (IS_INODE(page)) {
1202 					if (!is_checkpointed_node(sbi, ino) &&
1203 						!has_fsynced_inode(sbi, ino))
1204 						set_dentry_mark(page, 1);
1205 					else
1206 						set_dentry_mark(page, 0);
1207 				}
1208 				nwritten++;
1209 			} else {
1210 				set_fsync_mark(page, 0);
1211 				set_dentry_mark(page, 0);
1212 			}
1213 
1214 			if (NODE_MAPPING(sbi)->a_ops->writepage(page, wbc))
1215 				unlock_page(page);
1216 			else
1217 				wrote++;
1218 
1219 			if (--wbc->nr_to_write == 0)
1220 				break;
1221 		}
1222 		pagevec_release(&pvec);
1223 		cond_resched();
1224 
1225 		if (wbc->nr_to_write == 0) {
1226 			step = 2;
1227 			break;
1228 		}
1229 	}
1230 
1231 	if (step < 2) {
1232 		step++;
1233 		goto next_step;
1234 	}
1235 
1236 	if (wrote)
1237 		f2fs_submit_merged_bio(sbi, NODE, WRITE);
1238 	return nwritten;
1239 }
1240 
1241 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
1242 {
1243 	pgoff_t index = 0, end = LONG_MAX;
1244 	struct pagevec pvec;
1245 	int ret2 = 0, ret = 0;
1246 
1247 	pagevec_init(&pvec, 0);
1248 
1249 	while (index <= end) {
1250 		int i, nr_pages;
1251 		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1252 				PAGECACHE_TAG_WRITEBACK,
1253 				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1254 		if (nr_pages == 0)
1255 			break;
1256 
1257 		for (i = 0; i < nr_pages; i++) {
1258 			struct page *page = pvec.pages[i];
1259 
1260 			/* until radix tree lookup accepts end_index */
1261 			if (unlikely(page->index > end))
1262 				continue;
1263 
1264 			if (ino && ino_of_node(page) == ino) {
1265 				f2fs_wait_on_page_writeback(page, NODE);
1266 				if (TestClearPageError(page))
1267 					ret = -EIO;
1268 			}
1269 		}
1270 		pagevec_release(&pvec);
1271 		cond_resched();
1272 	}
1273 
1274 	if (unlikely(test_and_clear_bit(AS_ENOSPC, &NODE_MAPPING(sbi)->flags)))
1275 		ret2 = -ENOSPC;
1276 	if (unlikely(test_and_clear_bit(AS_EIO, &NODE_MAPPING(sbi)->flags)))
1277 		ret2 = -EIO;
1278 	if (!ret)
1279 		ret = ret2;
1280 	return ret;
1281 }
1282 
1283 static int f2fs_write_node_page(struct page *page,
1284 				struct writeback_control *wbc)
1285 {
1286 	struct f2fs_sb_info *sbi = F2FS_P_SB(page);
1287 	nid_t nid;
1288 	block_t new_addr;
1289 	struct node_info ni;
1290 	struct f2fs_io_info fio = {
1291 		.type = NODE,
1292 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1293 	};
1294 
1295 	trace_f2fs_writepage(page, NODE);
1296 
1297 	if (unlikely(sbi->por_doing))
1298 		goto redirty_out;
1299 	if (unlikely(f2fs_cp_error(sbi)))
1300 		goto redirty_out;
1301 
1302 	f2fs_wait_on_page_writeback(page, NODE);
1303 
1304 	/* get old block addr of this node page */
1305 	nid = nid_of_node(page);
1306 	f2fs_bug_on(sbi, page->index != nid);
1307 
1308 	get_node_info(sbi, nid, &ni);
1309 
1310 	/* This page is already truncated */
1311 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
1312 		dec_page_count(sbi, F2FS_DIRTY_NODES);
1313 		unlock_page(page);
1314 		return 0;
1315 	}
1316 
1317 	if (wbc->for_reclaim) {
1318 		if (!down_read_trylock(&sbi->node_write))
1319 			goto redirty_out;
1320 	} else {
1321 		down_read(&sbi->node_write);
1322 	}
1323 	set_page_writeback(page);
1324 	write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
1325 	set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
1326 	dec_page_count(sbi, F2FS_DIRTY_NODES);
1327 	up_read(&sbi->node_write);
1328 	unlock_page(page);
1329 
1330 	if (wbc->for_reclaim)
1331 		f2fs_submit_merged_bio(sbi, NODE, WRITE);
1332 
1333 	return 0;
1334 
1335 redirty_out:
1336 	redirty_page_for_writepage(wbc, page);
1337 	return AOP_WRITEPAGE_ACTIVATE;
1338 }
1339 
1340 static int f2fs_write_node_pages(struct address_space *mapping,
1341 			    struct writeback_control *wbc)
1342 {
1343 	struct f2fs_sb_info *sbi = F2FS_M_SB(mapping);
1344 	long diff;
1345 
1346 	trace_f2fs_writepages(mapping->host, wbc, NODE);
1347 
1348 	/* balancing f2fs's metadata in background */
1349 	f2fs_balance_fs_bg(sbi);
1350 
1351 	/* collect a number of dirty node pages and write together */
1352 	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
1353 		goto skip_write;
1354 
1355 	diff = nr_pages_to_write(sbi, NODE, wbc);
1356 	wbc->sync_mode = WB_SYNC_NONE;
1357 	sync_node_pages(sbi, 0, wbc);
1358 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1359 	return 0;
1360 
1361 skip_write:
1362 	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
1363 	return 0;
1364 }
1365 
1366 static int f2fs_set_node_page_dirty(struct page *page)
1367 {
1368 	trace_f2fs_set_page_dirty(page, NODE);
1369 
1370 	SetPageUptodate(page);
1371 	if (!PageDirty(page)) {
1372 		__set_page_dirty_nobuffers(page);
1373 		inc_page_count(F2FS_P_SB(page), F2FS_DIRTY_NODES);
1374 		SetPagePrivate(page);
1375 		return 1;
1376 	}
1377 	return 0;
1378 }
1379 
1380 static void f2fs_invalidate_node_page(struct page *page, unsigned int offset,
1381 				      unsigned int length)
1382 {
1383 	struct inode *inode = page->mapping->host;
1384 	if (PageDirty(page))
1385 		dec_page_count(F2FS_I_SB(inode), F2FS_DIRTY_NODES);
1386 	ClearPagePrivate(page);
1387 }
1388 
1389 static int f2fs_release_node_page(struct page *page, gfp_t wait)
1390 {
1391 	ClearPagePrivate(page);
1392 	return 1;
1393 }
1394 
1395 /*
1396  * Structure of the f2fs node operations
1397  */
1398 const struct address_space_operations f2fs_node_aops = {
1399 	.writepage	= f2fs_write_node_page,
1400 	.writepages	= f2fs_write_node_pages,
1401 	.set_page_dirty	= f2fs_set_node_page_dirty,
1402 	.invalidatepage	= f2fs_invalidate_node_page,
1403 	.releasepage	= f2fs_release_node_page,
1404 };
1405 
1406 static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
1407 						nid_t n)
1408 {
1409 	return radix_tree_lookup(&nm_i->free_nid_root, n);
1410 }
1411 
1412 static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
1413 						struct free_nid *i)
1414 {
1415 	list_del(&i->list);
1416 	radix_tree_delete(&nm_i->free_nid_root, i->nid);
1417 }
1418 
1419 static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
1420 {
1421 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1422 	struct free_nid *i;
1423 	struct nat_entry *ne;
1424 	bool allocated = false;
1425 
1426 	if (!available_free_memory(sbi, FREE_NIDS))
1427 		return -1;
1428 
1429 	/* 0 nid should not be used */
1430 	if (unlikely(nid == 0))
1431 		return 0;
1432 
1433 	if (build) {
1434 		/* do not add allocated nids */
1435 		down_read(&nm_i->nat_tree_lock);
1436 		ne = __lookup_nat_cache(nm_i, nid);
1437 		if (ne &&
1438 			(!get_nat_flag(ne, IS_CHECKPOINTED) ||
1439 				nat_get_blkaddr(ne) != NULL_ADDR))
1440 			allocated = true;
1441 		up_read(&nm_i->nat_tree_lock);
1442 		if (allocated)
1443 			return 0;
1444 	}
1445 
1446 	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
1447 	i->nid = nid;
1448 	i->state = NID_NEW;
1449 
1450 	if (radix_tree_preload(GFP_NOFS)) {
1451 		kmem_cache_free(free_nid_slab, i);
1452 		return 0;
1453 	}
1454 
1455 	spin_lock(&nm_i->free_nid_list_lock);
1456 	if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
1457 		spin_unlock(&nm_i->free_nid_list_lock);
1458 		radix_tree_preload_end();
1459 		kmem_cache_free(free_nid_slab, i);
1460 		return 0;
1461 	}
1462 	list_add_tail(&i->list, &nm_i->free_nid_list);
1463 	nm_i->fcnt++;
1464 	spin_unlock(&nm_i->free_nid_list_lock);
1465 	radix_tree_preload_end();
1466 	return 1;
1467 }
1468 
1469 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1470 {
1471 	struct free_nid *i;
1472 	bool need_free = false;
1473 
1474 	spin_lock(&nm_i->free_nid_list_lock);
1475 	i = __lookup_free_nid_list(nm_i, nid);
1476 	if (i && i->state == NID_NEW) {
1477 		__del_from_free_nid_list(nm_i, i);
1478 		nm_i->fcnt--;
1479 		need_free = true;
1480 	}
1481 	spin_unlock(&nm_i->free_nid_list_lock);
1482 
1483 	if (need_free)
1484 		kmem_cache_free(free_nid_slab, i);
1485 }
1486 
1487 static void scan_nat_page(struct f2fs_sb_info *sbi,
1488 			struct page *nat_page, nid_t start_nid)
1489 {
1490 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1491 	struct f2fs_nat_block *nat_blk = page_address(nat_page);
1492 	block_t blk_addr;
1493 	int i;
1494 
1495 	i = start_nid % NAT_ENTRY_PER_BLOCK;
1496 
1497 	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
1498 
1499 		if (unlikely(start_nid >= nm_i->max_nid))
1500 			break;
1501 
1502 		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
1503 		f2fs_bug_on(sbi, blk_addr == NEW_ADDR);
1504 		if (blk_addr == NULL_ADDR) {
1505 			if (add_free_nid(sbi, start_nid, true) < 0)
1506 				break;
1507 		}
1508 	}
1509 }
1510 
1511 static void build_free_nids(struct f2fs_sb_info *sbi)
1512 {
1513 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1514 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1515 	struct f2fs_summary_block *sum = curseg->sum_blk;
1516 	int i = 0;
1517 	nid_t nid = nm_i->next_scan_nid;
1518 
1519 	/* Enough entries */
1520 	if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
1521 		return;
1522 
1523 	/* readahead nat pages to be scanned */
1524 	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
1525 
1526 	while (1) {
1527 		struct page *page = get_current_nat_page(sbi, nid);
1528 
1529 		scan_nat_page(sbi, page, nid);
1530 		f2fs_put_page(page, 1);
1531 
1532 		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
1533 		if (unlikely(nid >= nm_i->max_nid))
1534 			nid = 0;
1535 
1536 		if (i++ == FREE_NID_PAGES)
1537 			break;
1538 	}
1539 
1540 	/* go to the next free nat pages to find free nids abundantly */
1541 	nm_i->next_scan_nid = nid;
1542 
1543 	/* find free nids from current sum_pages */
1544 	mutex_lock(&curseg->curseg_mutex);
1545 	for (i = 0; i < nats_in_cursum(sum); i++) {
1546 		block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
1547 		nid = le32_to_cpu(nid_in_journal(sum, i));
1548 		if (addr == NULL_ADDR)
1549 			add_free_nid(sbi, nid, true);
1550 		else
1551 			remove_free_nid(nm_i, nid);
1552 	}
1553 	mutex_unlock(&curseg->curseg_mutex);
1554 }
1555 
1556 /*
1557  * If this function returns success, caller can obtain a new nid
1558  * from second parameter of this function.
1559  * The returned nid could be used ino as well as nid when inode is created.
1560  */
1561 bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
1562 {
1563 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1564 	struct free_nid *i = NULL;
1565 retry:
1566 	if (unlikely(sbi->total_valid_node_count + 1 > nm_i->available_nids))
1567 		return false;
1568 
1569 	spin_lock(&nm_i->free_nid_list_lock);
1570 
1571 	/* We should not use stale free nids created by build_free_nids */
1572 	if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
1573 		f2fs_bug_on(sbi, list_empty(&nm_i->free_nid_list));
1574 		list_for_each_entry(i, &nm_i->free_nid_list, list)
1575 			if (i->state == NID_NEW)
1576 				break;
1577 
1578 		f2fs_bug_on(sbi, i->state != NID_NEW);
1579 		*nid = i->nid;
1580 		i->state = NID_ALLOC;
1581 		nm_i->fcnt--;
1582 		spin_unlock(&nm_i->free_nid_list_lock);
1583 		return true;
1584 	}
1585 	spin_unlock(&nm_i->free_nid_list_lock);
1586 
1587 	/* Let's scan nat pages and its caches to get free nids */
1588 	mutex_lock(&nm_i->build_lock);
1589 	build_free_nids(sbi);
1590 	mutex_unlock(&nm_i->build_lock);
1591 	goto retry;
1592 }
1593 
1594 /*
1595  * alloc_nid() should be called prior to this function.
1596  */
1597 void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
1598 {
1599 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1600 	struct free_nid *i;
1601 
1602 	spin_lock(&nm_i->free_nid_list_lock);
1603 	i = __lookup_free_nid_list(nm_i, nid);
1604 	f2fs_bug_on(sbi, !i || i->state != NID_ALLOC);
1605 	__del_from_free_nid_list(nm_i, i);
1606 	spin_unlock(&nm_i->free_nid_list_lock);
1607 
1608 	kmem_cache_free(free_nid_slab, i);
1609 }
1610 
1611 /*
1612  * alloc_nid() should be called prior to this function.
1613  */
1614 void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
1615 {
1616 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1617 	struct free_nid *i;
1618 	bool need_free = false;
1619 
1620 	if (!nid)
1621 		return;
1622 
1623 	spin_lock(&nm_i->free_nid_list_lock);
1624 	i = __lookup_free_nid_list(nm_i, nid);
1625 	f2fs_bug_on(sbi, !i || i->state != NID_ALLOC);
1626 	if (!available_free_memory(sbi, FREE_NIDS)) {
1627 		__del_from_free_nid_list(nm_i, i);
1628 		need_free = true;
1629 	} else {
1630 		i->state = NID_NEW;
1631 		nm_i->fcnt++;
1632 	}
1633 	spin_unlock(&nm_i->free_nid_list_lock);
1634 
1635 	if (need_free)
1636 		kmem_cache_free(free_nid_slab, i);
1637 }
1638 
1639 void recover_inline_xattr(struct inode *inode, struct page *page)
1640 {
1641 	void *src_addr, *dst_addr;
1642 	size_t inline_size;
1643 	struct page *ipage;
1644 	struct f2fs_inode *ri;
1645 
1646 	ipage = get_node_page(F2FS_I_SB(inode), inode->i_ino);
1647 	f2fs_bug_on(F2FS_I_SB(inode), IS_ERR(ipage));
1648 
1649 	ri = F2FS_INODE(page);
1650 	if (!(ri->i_inline & F2FS_INLINE_XATTR)) {
1651 		clear_inode_flag(F2FS_I(inode), FI_INLINE_XATTR);
1652 		goto update_inode;
1653 	}
1654 
1655 	dst_addr = inline_xattr_addr(ipage);
1656 	src_addr = inline_xattr_addr(page);
1657 	inline_size = inline_xattr_size(inode);
1658 
1659 	f2fs_wait_on_page_writeback(ipage, NODE);
1660 	memcpy(dst_addr, src_addr, inline_size);
1661 update_inode:
1662 	update_inode(inode, ipage);
1663 	f2fs_put_page(ipage, 1);
1664 }
1665 
1666 void recover_xattr_data(struct inode *inode, struct page *page, block_t blkaddr)
1667 {
1668 	struct f2fs_sb_info *sbi = F2FS_I_SB(inode);
1669 	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
1670 	nid_t new_xnid = nid_of_node(page);
1671 	struct node_info ni;
1672 
1673 	/* 1: invalidate the previous xattr nid */
1674 	if (!prev_xnid)
1675 		goto recover_xnid;
1676 
1677 	/* Deallocate node address */
1678 	get_node_info(sbi, prev_xnid, &ni);
1679 	f2fs_bug_on(sbi, ni.blk_addr == NULL_ADDR);
1680 	invalidate_blocks(sbi, ni.blk_addr);
1681 	dec_valid_node_count(sbi, inode);
1682 	set_node_addr(sbi, &ni, NULL_ADDR, false);
1683 
1684 recover_xnid:
1685 	/* 2: allocate new xattr nid */
1686 	if (unlikely(!inc_valid_node_count(sbi, inode)))
1687 		f2fs_bug_on(sbi, 1);
1688 
1689 	remove_free_nid(NM_I(sbi), new_xnid);
1690 	get_node_info(sbi, new_xnid, &ni);
1691 	ni.ino = inode->i_ino;
1692 	set_node_addr(sbi, &ni, NEW_ADDR, false);
1693 	F2FS_I(inode)->i_xattr_nid = new_xnid;
1694 
1695 	/* 3: update xattr blkaddr */
1696 	refresh_sit_entry(sbi, NEW_ADDR, blkaddr);
1697 	set_node_addr(sbi, &ni, blkaddr, false);
1698 
1699 	update_inode_page(inode);
1700 }
1701 
1702 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
1703 {
1704 	struct f2fs_inode *src, *dst;
1705 	nid_t ino = ino_of_node(page);
1706 	struct node_info old_ni, new_ni;
1707 	struct page *ipage;
1708 
1709 	get_node_info(sbi, ino, &old_ni);
1710 
1711 	if (unlikely(old_ni.blk_addr != NULL_ADDR))
1712 		return -EINVAL;
1713 
1714 	ipage = grab_cache_page(NODE_MAPPING(sbi), ino);
1715 	if (!ipage)
1716 		return -ENOMEM;
1717 
1718 	/* Should not use this inode from free nid list */
1719 	remove_free_nid(NM_I(sbi), ino);
1720 
1721 	SetPageUptodate(ipage);
1722 	fill_node_footer(ipage, ino, ino, 0, true);
1723 
1724 	src = F2FS_INODE(page);
1725 	dst = F2FS_INODE(ipage);
1726 
1727 	memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
1728 	dst->i_size = 0;
1729 	dst->i_blocks = cpu_to_le64(1);
1730 	dst->i_links = cpu_to_le32(1);
1731 	dst->i_xattr_nid = 0;
1732 	dst->i_inline = src->i_inline & F2FS_INLINE_XATTR;
1733 
1734 	new_ni = old_ni;
1735 	new_ni.ino = ino;
1736 
1737 	if (unlikely(!inc_valid_node_count(sbi, NULL)))
1738 		WARN_ON(1);
1739 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
1740 	inc_valid_inode_count(sbi);
1741 	set_page_dirty(ipage);
1742 	f2fs_put_page(ipage, 1);
1743 	return 0;
1744 }
1745 
1746 /*
1747  * ra_sum_pages() merge contiguous pages into one bio and submit.
1748  * these pre-read pages are allocated in bd_inode's mapping tree.
1749  */
1750 static int ra_sum_pages(struct f2fs_sb_info *sbi, struct page **pages,
1751 				int start, int nrpages)
1752 {
1753 	struct inode *inode = sbi->sb->s_bdev->bd_inode;
1754 	struct address_space *mapping = inode->i_mapping;
1755 	int i, page_idx = start;
1756 	struct f2fs_io_info fio = {
1757 		.type = META,
1758 		.rw = READ_SYNC | REQ_META | REQ_PRIO
1759 	};
1760 
1761 	for (i = 0; page_idx < start + nrpages; page_idx++, i++) {
1762 		/* alloc page in bd_inode for reading node summary info */
1763 		pages[i] = grab_cache_page(mapping, page_idx);
1764 		if (!pages[i])
1765 			break;
1766 		f2fs_submit_page_mbio(sbi, pages[i], page_idx, &fio);
1767 	}
1768 
1769 	f2fs_submit_merged_bio(sbi, META, READ);
1770 	return i;
1771 }
1772 
1773 int restore_node_summary(struct f2fs_sb_info *sbi,
1774 			unsigned int segno, struct f2fs_summary_block *sum)
1775 {
1776 	struct f2fs_node *rn;
1777 	struct f2fs_summary *sum_entry;
1778 	struct inode *inode = sbi->sb->s_bdev->bd_inode;
1779 	block_t addr;
1780 	int bio_blocks = MAX_BIO_BLOCKS(sbi);
1781 	struct page *pages[bio_blocks];
1782 	int i, idx, last_offset, nrpages, err = 0;
1783 
1784 	/* scan the node segment */
1785 	last_offset = sbi->blocks_per_seg;
1786 	addr = START_BLOCK(sbi, segno);
1787 	sum_entry = &sum->entries[0];
1788 
1789 	for (i = 0; !err && i < last_offset; i += nrpages, addr += nrpages) {
1790 		nrpages = min(last_offset - i, bio_blocks);
1791 
1792 		/* readahead node pages */
1793 		nrpages = ra_sum_pages(sbi, pages, addr, nrpages);
1794 		if (!nrpages)
1795 			return -ENOMEM;
1796 
1797 		for (idx = 0; idx < nrpages; idx++) {
1798 			if (err)
1799 				goto skip;
1800 
1801 			lock_page(pages[idx]);
1802 			if (unlikely(!PageUptodate(pages[idx]))) {
1803 				err = -EIO;
1804 			} else {
1805 				rn = F2FS_NODE(pages[idx]);
1806 				sum_entry->nid = rn->footer.nid;
1807 				sum_entry->version = 0;
1808 				sum_entry->ofs_in_node = 0;
1809 				sum_entry++;
1810 			}
1811 			unlock_page(pages[idx]);
1812 skip:
1813 			page_cache_release(pages[idx]);
1814 		}
1815 
1816 		invalidate_mapping_pages(inode->i_mapping, addr,
1817 							addr + nrpages);
1818 	}
1819 	return err;
1820 }
1821 
1822 static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
1823 {
1824 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1825 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1826 	struct f2fs_summary_block *sum = curseg->sum_blk;
1827 	int i;
1828 
1829 	mutex_lock(&curseg->curseg_mutex);
1830 	for (i = 0; i < nats_in_cursum(sum); i++) {
1831 		struct nat_entry *ne;
1832 		struct f2fs_nat_entry raw_ne;
1833 		nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
1834 
1835 		raw_ne = nat_in_journal(sum, i);
1836 retry:
1837 		down_write(&nm_i->nat_tree_lock);
1838 		ne = __lookup_nat_cache(nm_i, nid);
1839 		if (ne)
1840 			goto found;
1841 
1842 		ne = grab_nat_entry(nm_i, nid);
1843 		if (!ne) {
1844 			up_write(&nm_i->nat_tree_lock);
1845 			goto retry;
1846 		}
1847 		node_info_from_raw_nat(&ne->ni, &raw_ne);
1848 found:
1849 		__set_nat_cache_dirty(nm_i, ne);
1850 		up_write(&nm_i->nat_tree_lock);
1851 	}
1852 	update_nats_in_cursum(sum, -i);
1853 	mutex_unlock(&curseg->curseg_mutex);
1854 }
1855 
1856 static void __adjust_nat_entry_set(struct nat_entry_set *nes,
1857 						struct list_head *head, int max)
1858 {
1859 	struct nat_entry_set *cur;
1860 
1861 	if (nes->entry_cnt >= max)
1862 		goto add_out;
1863 
1864 	list_for_each_entry(cur, head, set_list) {
1865 		if (cur->entry_cnt >= nes->entry_cnt) {
1866 			list_add(&nes->set_list, cur->set_list.prev);
1867 			return;
1868 		}
1869 	}
1870 add_out:
1871 	list_add_tail(&nes->set_list, head);
1872 }
1873 
1874 static void __flush_nat_entry_set(struct f2fs_sb_info *sbi,
1875 					struct nat_entry_set *set)
1876 {
1877 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1878 	struct f2fs_summary_block *sum = curseg->sum_blk;
1879 	nid_t start_nid = set->set * NAT_ENTRY_PER_BLOCK;
1880 	bool to_journal = true;
1881 	struct f2fs_nat_block *nat_blk;
1882 	struct nat_entry *ne, *cur;
1883 	struct page *page = NULL;
1884 
1885 	/*
1886 	 * there are two steps to flush nat entries:
1887 	 * #1, flush nat entries to journal in current hot data summary block.
1888 	 * #2, flush nat entries to nat page.
1889 	 */
1890 	if (!__has_cursum_space(sum, set->entry_cnt, NAT_JOURNAL))
1891 		to_journal = false;
1892 
1893 	if (to_journal) {
1894 		mutex_lock(&curseg->curseg_mutex);
1895 	} else {
1896 		page = get_next_nat_page(sbi, start_nid);
1897 		nat_blk = page_address(page);
1898 		f2fs_bug_on(sbi, !nat_blk);
1899 	}
1900 
1901 	/* flush dirty nats in nat entry set */
1902 	list_for_each_entry_safe(ne, cur, &set->entry_list, list) {
1903 		struct f2fs_nat_entry *raw_ne;
1904 		nid_t nid = nat_get_nid(ne);
1905 		int offset;
1906 
1907 		if (nat_get_blkaddr(ne) == NEW_ADDR)
1908 			continue;
1909 
1910 		if (to_journal) {
1911 			offset = lookup_journal_in_cursum(sum,
1912 							NAT_JOURNAL, nid, 1);
1913 			f2fs_bug_on(sbi, offset < 0);
1914 			raw_ne = &nat_in_journal(sum, offset);
1915 			nid_in_journal(sum, offset) = cpu_to_le32(nid);
1916 		} else {
1917 			raw_ne = &nat_blk->entries[nid - start_nid];
1918 		}
1919 		raw_nat_from_node_info(raw_ne, &ne->ni);
1920 
1921 		down_write(&NM_I(sbi)->nat_tree_lock);
1922 		nat_reset_flag(ne);
1923 		__clear_nat_cache_dirty(NM_I(sbi), ne);
1924 		up_write(&NM_I(sbi)->nat_tree_lock);
1925 
1926 		if (nat_get_blkaddr(ne) == NULL_ADDR)
1927 			add_free_nid(sbi, nid, false);
1928 	}
1929 
1930 	if (to_journal)
1931 		mutex_unlock(&curseg->curseg_mutex);
1932 	else
1933 		f2fs_put_page(page, 1);
1934 
1935 	f2fs_bug_on(sbi, set->entry_cnt);
1936 
1937 	radix_tree_delete(&NM_I(sbi)->nat_set_root, set->set);
1938 	kmem_cache_free(nat_entry_set_slab, set);
1939 }
1940 
1941 /*
1942  * This function is called during the checkpointing process.
1943  */
1944 void flush_nat_entries(struct f2fs_sb_info *sbi)
1945 {
1946 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1947 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1948 	struct f2fs_summary_block *sum = curseg->sum_blk;
1949 	struct nat_entry_set *setvec[NATVEC_SIZE];
1950 	struct nat_entry_set *set, *tmp;
1951 	unsigned int found;
1952 	nid_t set_idx = 0;
1953 	LIST_HEAD(sets);
1954 
1955 	if (!nm_i->dirty_nat_cnt)
1956 		return;
1957 	/*
1958 	 * if there are no enough space in journal to store dirty nat
1959 	 * entries, remove all entries from journal and merge them
1960 	 * into nat entry set.
1961 	 */
1962 	if (!__has_cursum_space(sum, nm_i->dirty_nat_cnt, NAT_JOURNAL))
1963 		remove_nats_in_journal(sbi);
1964 
1965 	while ((found = __gang_lookup_nat_set(nm_i,
1966 					set_idx, NATVEC_SIZE, setvec))) {
1967 		unsigned idx;
1968 		set_idx = setvec[found - 1]->set + 1;
1969 		for (idx = 0; idx < found; idx++)
1970 			__adjust_nat_entry_set(setvec[idx], &sets,
1971 							MAX_NAT_JENTRIES(sum));
1972 	}
1973 
1974 	/* flush dirty nats in nat entry set */
1975 	list_for_each_entry_safe(set, tmp, &sets, set_list)
1976 		__flush_nat_entry_set(sbi, set);
1977 
1978 	f2fs_bug_on(sbi, nm_i->dirty_nat_cnt);
1979 }
1980 
1981 static int init_node_manager(struct f2fs_sb_info *sbi)
1982 {
1983 	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
1984 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1985 	unsigned char *version_bitmap;
1986 	unsigned int nat_segs, nat_blocks;
1987 
1988 	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
1989 
1990 	/* segment_count_nat includes pair segment so divide to 2. */
1991 	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
1992 	nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
1993 
1994 	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
1995 
1996 	/* not used nids: 0, node, meta, (and root counted as valid node) */
1997 	nm_i->available_nids = nm_i->max_nid - F2FS_RESERVED_NODE_NUM;
1998 	nm_i->fcnt = 0;
1999 	nm_i->nat_cnt = 0;
2000 	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
2001 
2002 	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
2003 	INIT_LIST_HEAD(&nm_i->free_nid_list);
2004 	INIT_RADIX_TREE(&nm_i->nat_root, GFP_NOIO);
2005 	INIT_RADIX_TREE(&nm_i->nat_set_root, GFP_NOIO);
2006 	INIT_LIST_HEAD(&nm_i->nat_entries);
2007 
2008 	mutex_init(&nm_i->build_lock);
2009 	spin_lock_init(&nm_i->free_nid_list_lock);
2010 	init_rwsem(&nm_i->nat_tree_lock);
2011 
2012 	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
2013 	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
2014 	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
2015 	if (!version_bitmap)
2016 		return -EFAULT;
2017 
2018 	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
2019 					GFP_KERNEL);
2020 	if (!nm_i->nat_bitmap)
2021 		return -ENOMEM;
2022 	return 0;
2023 }
2024 
2025 int build_node_manager(struct f2fs_sb_info *sbi)
2026 {
2027 	int err;
2028 
2029 	sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
2030 	if (!sbi->nm_info)
2031 		return -ENOMEM;
2032 
2033 	err = init_node_manager(sbi);
2034 	if (err)
2035 		return err;
2036 
2037 	build_free_nids(sbi);
2038 	return 0;
2039 }
2040 
2041 void destroy_node_manager(struct f2fs_sb_info *sbi)
2042 {
2043 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2044 	struct free_nid *i, *next_i;
2045 	struct nat_entry *natvec[NATVEC_SIZE];
2046 	nid_t nid = 0;
2047 	unsigned int found;
2048 
2049 	if (!nm_i)
2050 		return;
2051 
2052 	/* destroy free nid list */
2053 	spin_lock(&nm_i->free_nid_list_lock);
2054 	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
2055 		f2fs_bug_on(sbi, i->state == NID_ALLOC);
2056 		__del_from_free_nid_list(nm_i, i);
2057 		nm_i->fcnt--;
2058 		spin_unlock(&nm_i->free_nid_list_lock);
2059 		kmem_cache_free(free_nid_slab, i);
2060 		spin_lock(&nm_i->free_nid_list_lock);
2061 	}
2062 	f2fs_bug_on(sbi, nm_i->fcnt);
2063 	spin_unlock(&nm_i->free_nid_list_lock);
2064 
2065 	/* destroy nat cache */
2066 	down_write(&nm_i->nat_tree_lock);
2067 	while ((found = __gang_lookup_nat_cache(nm_i,
2068 					nid, NATVEC_SIZE, natvec))) {
2069 		unsigned idx;
2070 		nid = nat_get_nid(natvec[found - 1]) + 1;
2071 		for (idx = 0; idx < found; idx++)
2072 			__del_from_nat_cache(nm_i, natvec[idx]);
2073 	}
2074 	f2fs_bug_on(sbi, nm_i->nat_cnt);
2075 	up_write(&nm_i->nat_tree_lock);
2076 
2077 	kfree(nm_i->nat_bitmap);
2078 	sbi->nm_info = NULL;
2079 	kfree(nm_i);
2080 }
2081 
2082 int __init create_node_manager_caches(void)
2083 {
2084 	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
2085 			sizeof(struct nat_entry));
2086 	if (!nat_entry_slab)
2087 		goto fail;
2088 
2089 	free_nid_slab = f2fs_kmem_cache_create("free_nid",
2090 			sizeof(struct free_nid));
2091 	if (!free_nid_slab)
2092 		goto destroy_nat_entry;
2093 
2094 	nat_entry_set_slab = f2fs_kmem_cache_create("nat_entry_set",
2095 			sizeof(struct nat_entry_set));
2096 	if (!nat_entry_set_slab)
2097 		goto destroy_free_nid;
2098 	return 0;
2099 
2100 destroy_free_nid:
2101 	kmem_cache_destroy(free_nid_slab);
2102 destroy_nat_entry:
2103 	kmem_cache_destroy(nat_entry_slab);
2104 fail:
2105 	return -ENOMEM;
2106 }
2107 
2108 void destroy_node_manager_caches(void)
2109 {
2110 	kmem_cache_destroy(nat_entry_set_slab);
2111 	kmem_cache_destroy(free_nid_slab);
2112 	kmem_cache_destroy(nat_entry_slab);
2113 }
2114