xref: /openbmc/linux/fs/f2fs/node.c (revision b10778a00d40b3d9fdaaf5891e802794781ff71c)
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 mem_size = 0;
35 	bool res = false;
36 
37 	si_meminfo(&val);
38 	/* give 25%, 25%, 50% memory for each components respectively */
39 	if (type == FREE_NIDS) {
40 		mem_size = (nm_i->fcnt * sizeof(struct free_nid)) >> 12;
41 		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 2);
42 	} else if (type == NAT_ENTRIES) {
43 		mem_size = (nm_i->nat_cnt * sizeof(struct nat_entry)) >> 12;
44 		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 2);
45 	} else if (type == DIRTY_DENTS) {
46 		if (sbi->sb->s_bdi->dirty_exceeded)
47 			return false;
48 		mem_size = get_pages(sbi, F2FS_DIRTY_DENTS);
49 		res = mem_size < ((val.totalram * nm_i->ram_thresh / 100) >> 1);
50 	}
51 	return res;
52 }
53 
54 static void clear_node_page_dirty(struct page *page)
55 {
56 	struct address_space *mapping = page->mapping;
57 	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
58 	unsigned int long flags;
59 
60 	if (PageDirty(page)) {
61 		spin_lock_irqsave(&mapping->tree_lock, flags);
62 		radix_tree_tag_clear(&mapping->page_tree,
63 				page_index(page),
64 				PAGECACHE_TAG_DIRTY);
65 		spin_unlock_irqrestore(&mapping->tree_lock, flags);
66 
67 		clear_page_dirty_for_io(page);
68 		dec_page_count(sbi, F2FS_DIRTY_NODES);
69 	}
70 	ClearPageUptodate(page);
71 }
72 
73 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
74 {
75 	pgoff_t index = current_nat_addr(sbi, nid);
76 	return get_meta_page(sbi, index);
77 }
78 
79 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
80 {
81 	struct page *src_page;
82 	struct page *dst_page;
83 	pgoff_t src_off;
84 	pgoff_t dst_off;
85 	void *src_addr;
86 	void *dst_addr;
87 	struct f2fs_nm_info *nm_i = NM_I(sbi);
88 
89 	src_off = current_nat_addr(sbi, nid);
90 	dst_off = next_nat_addr(sbi, src_off);
91 
92 	/* get current nat block page with lock */
93 	src_page = get_meta_page(sbi, src_off);
94 	dst_page = grab_meta_page(sbi, dst_off);
95 	f2fs_bug_on(PageDirty(src_page));
96 
97 	src_addr = page_address(src_page);
98 	dst_addr = page_address(dst_page);
99 	memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
100 	set_page_dirty(dst_page);
101 	f2fs_put_page(src_page, 1);
102 
103 	set_to_next_nat(nm_i, nid);
104 
105 	return dst_page;
106 }
107 
108 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
109 {
110 	return radix_tree_lookup(&nm_i->nat_root, n);
111 }
112 
113 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
114 		nid_t start, unsigned int nr, struct nat_entry **ep)
115 {
116 	return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
117 }
118 
119 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
120 {
121 	list_del(&e->list);
122 	radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
123 	nm_i->nat_cnt--;
124 	kmem_cache_free(nat_entry_slab, e);
125 }
126 
127 int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
128 {
129 	struct f2fs_nm_info *nm_i = NM_I(sbi);
130 	struct nat_entry *e;
131 	int is_cp = 1;
132 
133 	read_lock(&nm_i->nat_tree_lock);
134 	e = __lookup_nat_cache(nm_i, nid);
135 	if (e && !e->checkpointed)
136 		is_cp = 0;
137 	read_unlock(&nm_i->nat_tree_lock);
138 	return is_cp;
139 }
140 
141 bool fsync_mark_done(struct f2fs_sb_info *sbi, nid_t nid)
142 {
143 	struct f2fs_nm_info *nm_i = NM_I(sbi);
144 	struct nat_entry *e;
145 	bool fsync_done = false;
146 
147 	read_lock(&nm_i->nat_tree_lock);
148 	e = __lookup_nat_cache(nm_i, nid);
149 	if (e)
150 		fsync_done = e->fsync_done;
151 	read_unlock(&nm_i->nat_tree_lock);
152 	return fsync_done;
153 }
154 
155 void fsync_mark_clear(struct f2fs_sb_info *sbi, nid_t nid)
156 {
157 	struct f2fs_nm_info *nm_i = NM_I(sbi);
158 	struct nat_entry *e;
159 
160 	write_lock(&nm_i->nat_tree_lock);
161 	e = __lookup_nat_cache(nm_i, nid);
162 	if (e)
163 		e->fsync_done = false;
164 	write_unlock(&nm_i->nat_tree_lock);
165 }
166 
167 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
168 {
169 	struct nat_entry *new;
170 
171 	new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
172 	if (!new)
173 		return NULL;
174 	if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
175 		kmem_cache_free(nat_entry_slab, new);
176 		return NULL;
177 	}
178 	memset(new, 0, sizeof(struct nat_entry));
179 	nat_set_nid(new, nid);
180 	new->checkpointed = true;
181 	list_add_tail(&new->list, &nm_i->nat_entries);
182 	nm_i->nat_cnt++;
183 	return new;
184 }
185 
186 static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
187 						struct f2fs_nat_entry *ne)
188 {
189 	struct nat_entry *e;
190 retry:
191 	write_lock(&nm_i->nat_tree_lock);
192 	e = __lookup_nat_cache(nm_i, nid);
193 	if (!e) {
194 		e = grab_nat_entry(nm_i, nid);
195 		if (!e) {
196 			write_unlock(&nm_i->nat_tree_lock);
197 			goto retry;
198 		}
199 		node_info_from_raw_nat(&e->ni, ne);
200 	}
201 	write_unlock(&nm_i->nat_tree_lock);
202 }
203 
204 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
205 			block_t new_blkaddr, bool fsync_done)
206 {
207 	struct f2fs_nm_info *nm_i = NM_I(sbi);
208 	struct nat_entry *e;
209 retry:
210 	write_lock(&nm_i->nat_tree_lock);
211 	e = __lookup_nat_cache(nm_i, ni->nid);
212 	if (!e) {
213 		e = grab_nat_entry(nm_i, ni->nid);
214 		if (!e) {
215 			write_unlock(&nm_i->nat_tree_lock);
216 			goto retry;
217 		}
218 		e->ni = *ni;
219 		f2fs_bug_on(ni->blk_addr == NEW_ADDR);
220 	} else if (new_blkaddr == NEW_ADDR) {
221 		/*
222 		 * when nid is reallocated,
223 		 * previous nat entry can be remained in nat cache.
224 		 * So, reinitialize it with new information.
225 		 */
226 		e->ni = *ni;
227 		f2fs_bug_on(ni->blk_addr != NULL_ADDR);
228 	}
229 
230 	/* sanity check */
231 	f2fs_bug_on(nat_get_blkaddr(e) != ni->blk_addr);
232 	f2fs_bug_on(nat_get_blkaddr(e) == NULL_ADDR &&
233 			new_blkaddr == NULL_ADDR);
234 	f2fs_bug_on(nat_get_blkaddr(e) == NEW_ADDR &&
235 			new_blkaddr == NEW_ADDR);
236 	f2fs_bug_on(nat_get_blkaddr(e) != NEW_ADDR &&
237 			nat_get_blkaddr(e) != NULL_ADDR &&
238 			new_blkaddr == NEW_ADDR);
239 
240 	/* increment version no as node is removed */
241 	if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
242 		unsigned char version = nat_get_version(e);
243 		nat_set_version(e, inc_node_version(version));
244 	}
245 
246 	/* change address */
247 	nat_set_blkaddr(e, new_blkaddr);
248 	__set_nat_cache_dirty(nm_i, e);
249 
250 	/* update fsync_mark if its inode nat entry is still alive */
251 	e = __lookup_nat_cache(nm_i, ni->ino);
252 	if (e)
253 		e->fsync_done = fsync_done;
254 	write_unlock(&nm_i->nat_tree_lock);
255 }
256 
257 int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
258 {
259 	struct f2fs_nm_info *nm_i = NM_I(sbi);
260 
261 	if (available_free_memory(sbi, NAT_ENTRIES))
262 		return 0;
263 
264 	write_lock(&nm_i->nat_tree_lock);
265 	while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
266 		struct nat_entry *ne;
267 		ne = list_first_entry(&nm_i->nat_entries,
268 					struct nat_entry, list);
269 		__del_from_nat_cache(nm_i, ne);
270 		nr_shrink--;
271 	}
272 	write_unlock(&nm_i->nat_tree_lock);
273 	return nr_shrink;
274 }
275 
276 /*
277  * This function always returns success
278  */
279 void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
280 {
281 	struct f2fs_nm_info *nm_i = NM_I(sbi);
282 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
283 	struct f2fs_summary_block *sum = curseg->sum_blk;
284 	nid_t start_nid = START_NID(nid);
285 	struct f2fs_nat_block *nat_blk;
286 	struct page *page = NULL;
287 	struct f2fs_nat_entry ne;
288 	struct nat_entry *e;
289 	int i;
290 
291 	memset(&ne, 0, sizeof(struct f2fs_nat_entry));
292 	ni->nid = nid;
293 
294 	/* Check nat cache */
295 	read_lock(&nm_i->nat_tree_lock);
296 	e = __lookup_nat_cache(nm_i, nid);
297 	if (e) {
298 		ni->ino = nat_get_ino(e);
299 		ni->blk_addr = nat_get_blkaddr(e);
300 		ni->version = nat_get_version(e);
301 	}
302 	read_unlock(&nm_i->nat_tree_lock);
303 	if (e)
304 		return;
305 
306 	/* Check current segment summary */
307 	mutex_lock(&curseg->curseg_mutex);
308 	i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
309 	if (i >= 0) {
310 		ne = nat_in_journal(sum, i);
311 		node_info_from_raw_nat(ni, &ne);
312 	}
313 	mutex_unlock(&curseg->curseg_mutex);
314 	if (i >= 0)
315 		goto cache;
316 
317 	/* Fill node_info from nat page */
318 	page = get_current_nat_page(sbi, start_nid);
319 	nat_blk = (struct f2fs_nat_block *)page_address(page);
320 	ne = nat_blk->entries[nid - start_nid];
321 	node_info_from_raw_nat(ni, &ne);
322 	f2fs_put_page(page, 1);
323 cache:
324 	/* cache nat entry */
325 	cache_nat_entry(NM_I(sbi), nid, &ne);
326 }
327 
328 /*
329  * The maximum depth is four.
330  * Offset[0] will have raw inode offset.
331  */
332 static int get_node_path(struct f2fs_inode_info *fi, long block,
333 				int offset[4], unsigned int noffset[4])
334 {
335 	const long direct_index = ADDRS_PER_INODE(fi);
336 	const long direct_blks = ADDRS_PER_BLOCK;
337 	const long dptrs_per_blk = NIDS_PER_BLOCK;
338 	const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
339 	const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
340 	int n = 0;
341 	int level = 0;
342 
343 	noffset[0] = 0;
344 
345 	if (block < direct_index) {
346 		offset[n] = block;
347 		goto got;
348 	}
349 	block -= direct_index;
350 	if (block < direct_blks) {
351 		offset[n++] = NODE_DIR1_BLOCK;
352 		noffset[n] = 1;
353 		offset[n] = block;
354 		level = 1;
355 		goto got;
356 	}
357 	block -= direct_blks;
358 	if (block < direct_blks) {
359 		offset[n++] = NODE_DIR2_BLOCK;
360 		noffset[n] = 2;
361 		offset[n] = block;
362 		level = 1;
363 		goto got;
364 	}
365 	block -= direct_blks;
366 	if (block < indirect_blks) {
367 		offset[n++] = NODE_IND1_BLOCK;
368 		noffset[n] = 3;
369 		offset[n++] = block / direct_blks;
370 		noffset[n] = 4 + offset[n - 1];
371 		offset[n] = block % direct_blks;
372 		level = 2;
373 		goto got;
374 	}
375 	block -= indirect_blks;
376 	if (block < indirect_blks) {
377 		offset[n++] = NODE_IND2_BLOCK;
378 		noffset[n] = 4 + dptrs_per_blk;
379 		offset[n++] = block / direct_blks;
380 		noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
381 		offset[n] = block % direct_blks;
382 		level = 2;
383 		goto got;
384 	}
385 	block -= indirect_blks;
386 	if (block < dindirect_blks) {
387 		offset[n++] = NODE_DIND_BLOCK;
388 		noffset[n] = 5 + (dptrs_per_blk * 2);
389 		offset[n++] = block / indirect_blks;
390 		noffset[n] = 6 + (dptrs_per_blk * 2) +
391 			      offset[n - 1] * (dptrs_per_blk + 1);
392 		offset[n++] = (block / direct_blks) % dptrs_per_blk;
393 		noffset[n] = 7 + (dptrs_per_blk * 2) +
394 			      offset[n - 2] * (dptrs_per_blk + 1) +
395 			      offset[n - 1];
396 		offset[n] = block % direct_blks;
397 		level = 3;
398 		goto got;
399 	} else {
400 		BUG();
401 	}
402 got:
403 	return level;
404 }
405 
406 /*
407  * Caller should call f2fs_put_dnode(dn).
408  * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
409  * f2fs_unlock_op() only if ro is not set RDONLY_NODE.
410  * In the case of RDONLY_NODE, we don't need to care about mutex.
411  */
412 int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
413 {
414 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
415 	struct page *npage[4];
416 	struct page *parent;
417 	int offset[4];
418 	unsigned int noffset[4];
419 	nid_t nids[4];
420 	int level, i;
421 	int err = 0;
422 
423 	level = get_node_path(F2FS_I(dn->inode), index, offset, noffset);
424 
425 	nids[0] = dn->inode->i_ino;
426 	npage[0] = dn->inode_page;
427 
428 	if (!npage[0]) {
429 		npage[0] = get_node_page(sbi, nids[0]);
430 		if (IS_ERR(npage[0]))
431 			return PTR_ERR(npage[0]);
432 	}
433 	parent = npage[0];
434 	if (level != 0)
435 		nids[1] = get_nid(parent, offset[0], true);
436 	dn->inode_page = npage[0];
437 	dn->inode_page_locked = true;
438 
439 	/* get indirect or direct nodes */
440 	for (i = 1; i <= level; i++) {
441 		bool done = false;
442 
443 		if (!nids[i] && mode == ALLOC_NODE) {
444 			/* alloc new node */
445 			if (!alloc_nid(sbi, &(nids[i]))) {
446 				err = -ENOSPC;
447 				goto release_pages;
448 			}
449 
450 			dn->nid = nids[i];
451 			npage[i] = new_node_page(dn, noffset[i], NULL);
452 			if (IS_ERR(npage[i])) {
453 				alloc_nid_failed(sbi, nids[i]);
454 				err = PTR_ERR(npage[i]);
455 				goto release_pages;
456 			}
457 
458 			set_nid(parent, offset[i - 1], nids[i], i == 1);
459 			alloc_nid_done(sbi, nids[i]);
460 			done = true;
461 		} else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
462 			npage[i] = get_node_page_ra(parent, offset[i - 1]);
463 			if (IS_ERR(npage[i])) {
464 				err = PTR_ERR(npage[i]);
465 				goto release_pages;
466 			}
467 			done = true;
468 		}
469 		if (i == 1) {
470 			dn->inode_page_locked = false;
471 			unlock_page(parent);
472 		} else {
473 			f2fs_put_page(parent, 1);
474 		}
475 
476 		if (!done) {
477 			npage[i] = get_node_page(sbi, nids[i]);
478 			if (IS_ERR(npage[i])) {
479 				err = PTR_ERR(npage[i]);
480 				f2fs_put_page(npage[0], 0);
481 				goto release_out;
482 			}
483 		}
484 		if (i < level) {
485 			parent = npage[i];
486 			nids[i + 1] = get_nid(parent, offset[i], false);
487 		}
488 	}
489 	dn->nid = nids[level];
490 	dn->ofs_in_node = offset[level];
491 	dn->node_page = npage[level];
492 	dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
493 	return 0;
494 
495 release_pages:
496 	f2fs_put_page(parent, 1);
497 	if (i > 1)
498 		f2fs_put_page(npage[0], 0);
499 release_out:
500 	dn->inode_page = NULL;
501 	dn->node_page = NULL;
502 	return err;
503 }
504 
505 static void truncate_node(struct dnode_of_data *dn)
506 {
507 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
508 	struct node_info ni;
509 
510 	get_node_info(sbi, dn->nid, &ni);
511 	if (dn->inode->i_blocks == 0) {
512 		f2fs_bug_on(ni.blk_addr != NULL_ADDR);
513 		goto invalidate;
514 	}
515 	f2fs_bug_on(ni.blk_addr == NULL_ADDR);
516 
517 	/* Deallocate node address */
518 	invalidate_blocks(sbi, ni.blk_addr);
519 	dec_valid_node_count(sbi, dn->inode);
520 	set_node_addr(sbi, &ni, NULL_ADDR, false);
521 
522 	if (dn->nid == dn->inode->i_ino) {
523 		remove_orphan_inode(sbi, dn->nid);
524 		dec_valid_inode_count(sbi);
525 	} else {
526 		sync_inode_page(dn);
527 	}
528 invalidate:
529 	clear_node_page_dirty(dn->node_page);
530 	F2FS_SET_SB_DIRT(sbi);
531 
532 	f2fs_put_page(dn->node_page, 1);
533 
534 	invalidate_mapping_pages(NODE_MAPPING(sbi),
535 			dn->node_page->index, dn->node_page->index);
536 
537 	dn->node_page = NULL;
538 	trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
539 }
540 
541 static int truncate_dnode(struct dnode_of_data *dn)
542 {
543 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
544 	struct page *page;
545 
546 	if (dn->nid == 0)
547 		return 1;
548 
549 	/* get direct node */
550 	page = get_node_page(sbi, dn->nid);
551 	if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
552 		return 1;
553 	else if (IS_ERR(page))
554 		return PTR_ERR(page);
555 
556 	/* Make dnode_of_data for parameter */
557 	dn->node_page = page;
558 	dn->ofs_in_node = 0;
559 	truncate_data_blocks(dn);
560 	truncate_node(dn);
561 	return 1;
562 }
563 
564 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
565 						int ofs, int depth)
566 {
567 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
568 	struct dnode_of_data rdn = *dn;
569 	struct page *page;
570 	struct f2fs_node *rn;
571 	nid_t child_nid;
572 	unsigned int child_nofs;
573 	int freed = 0;
574 	int i, ret;
575 
576 	if (dn->nid == 0)
577 		return NIDS_PER_BLOCK + 1;
578 
579 	trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
580 
581 	page = get_node_page(sbi, dn->nid);
582 	if (IS_ERR(page)) {
583 		trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
584 		return PTR_ERR(page);
585 	}
586 
587 	rn = F2FS_NODE(page);
588 	if (depth < 3) {
589 		for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
590 			child_nid = le32_to_cpu(rn->in.nid[i]);
591 			if (child_nid == 0)
592 				continue;
593 			rdn.nid = child_nid;
594 			ret = truncate_dnode(&rdn);
595 			if (ret < 0)
596 				goto out_err;
597 			set_nid(page, i, 0, false);
598 		}
599 	} else {
600 		child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
601 		for (i = ofs; i < NIDS_PER_BLOCK; i++) {
602 			child_nid = le32_to_cpu(rn->in.nid[i]);
603 			if (child_nid == 0) {
604 				child_nofs += NIDS_PER_BLOCK + 1;
605 				continue;
606 			}
607 			rdn.nid = child_nid;
608 			ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
609 			if (ret == (NIDS_PER_BLOCK + 1)) {
610 				set_nid(page, i, 0, false);
611 				child_nofs += ret;
612 			} else if (ret < 0 && ret != -ENOENT) {
613 				goto out_err;
614 			}
615 		}
616 		freed = child_nofs;
617 	}
618 
619 	if (!ofs) {
620 		/* remove current indirect node */
621 		dn->node_page = page;
622 		truncate_node(dn);
623 		freed++;
624 	} else {
625 		f2fs_put_page(page, 1);
626 	}
627 	trace_f2fs_truncate_nodes_exit(dn->inode, freed);
628 	return freed;
629 
630 out_err:
631 	f2fs_put_page(page, 1);
632 	trace_f2fs_truncate_nodes_exit(dn->inode, ret);
633 	return ret;
634 }
635 
636 static int truncate_partial_nodes(struct dnode_of_data *dn,
637 			struct f2fs_inode *ri, int *offset, int depth)
638 {
639 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
640 	struct page *pages[2];
641 	nid_t nid[3];
642 	nid_t child_nid;
643 	int err = 0;
644 	int i;
645 	int idx = depth - 2;
646 
647 	nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
648 	if (!nid[0])
649 		return 0;
650 
651 	/* get indirect nodes in the path */
652 	for (i = 0; i < idx + 1; i++) {
653 		/* reference count'll be increased */
654 		pages[i] = get_node_page(sbi, nid[i]);
655 		if (IS_ERR(pages[i])) {
656 			err = PTR_ERR(pages[i]);
657 			idx = i - 1;
658 			goto fail;
659 		}
660 		nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
661 	}
662 
663 	/* free direct nodes linked to a partial indirect node */
664 	for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
665 		child_nid = get_nid(pages[idx], i, false);
666 		if (!child_nid)
667 			continue;
668 		dn->nid = child_nid;
669 		err = truncate_dnode(dn);
670 		if (err < 0)
671 			goto fail;
672 		set_nid(pages[idx], i, 0, false);
673 	}
674 
675 	if (offset[idx + 1] == 0) {
676 		dn->node_page = pages[idx];
677 		dn->nid = nid[idx];
678 		truncate_node(dn);
679 	} else {
680 		f2fs_put_page(pages[idx], 1);
681 	}
682 	offset[idx]++;
683 	offset[idx + 1] = 0;
684 	idx--;
685 fail:
686 	for (i = idx; i >= 0; i--)
687 		f2fs_put_page(pages[i], 1);
688 
689 	trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
690 
691 	return err;
692 }
693 
694 /*
695  * All the block addresses of data and nodes should be nullified.
696  */
697 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
698 {
699 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
700 	int err = 0, cont = 1;
701 	int level, offset[4], noffset[4];
702 	unsigned int nofs = 0;
703 	struct f2fs_inode *ri;
704 	struct dnode_of_data dn;
705 	struct page *page;
706 
707 	trace_f2fs_truncate_inode_blocks_enter(inode, from);
708 
709 	level = get_node_path(F2FS_I(inode), from, offset, noffset);
710 restart:
711 	page = get_node_page(sbi, inode->i_ino);
712 	if (IS_ERR(page)) {
713 		trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
714 		return PTR_ERR(page);
715 	}
716 
717 	set_new_dnode(&dn, inode, page, NULL, 0);
718 	unlock_page(page);
719 
720 	ri = F2FS_INODE(page);
721 	switch (level) {
722 	case 0:
723 	case 1:
724 		nofs = noffset[1];
725 		break;
726 	case 2:
727 		nofs = noffset[1];
728 		if (!offset[level - 1])
729 			goto skip_partial;
730 		err = truncate_partial_nodes(&dn, ri, offset, level);
731 		if (err < 0 && err != -ENOENT)
732 			goto fail;
733 		nofs += 1 + NIDS_PER_BLOCK;
734 		break;
735 	case 3:
736 		nofs = 5 + 2 * NIDS_PER_BLOCK;
737 		if (!offset[level - 1])
738 			goto skip_partial;
739 		err = truncate_partial_nodes(&dn, ri, offset, level);
740 		if (err < 0 && err != -ENOENT)
741 			goto fail;
742 		break;
743 	default:
744 		BUG();
745 	}
746 
747 skip_partial:
748 	while (cont) {
749 		dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
750 		switch (offset[0]) {
751 		case NODE_DIR1_BLOCK:
752 		case NODE_DIR2_BLOCK:
753 			err = truncate_dnode(&dn);
754 			break;
755 
756 		case NODE_IND1_BLOCK:
757 		case NODE_IND2_BLOCK:
758 			err = truncate_nodes(&dn, nofs, offset[1], 2);
759 			break;
760 
761 		case NODE_DIND_BLOCK:
762 			err = truncate_nodes(&dn, nofs, offset[1], 3);
763 			cont = 0;
764 			break;
765 
766 		default:
767 			BUG();
768 		}
769 		if (err < 0 && err != -ENOENT)
770 			goto fail;
771 		if (offset[1] == 0 &&
772 				ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
773 			lock_page(page);
774 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
775 				f2fs_put_page(page, 1);
776 				goto restart;
777 			}
778 			f2fs_wait_on_page_writeback(page, NODE);
779 			ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
780 			set_page_dirty(page);
781 			unlock_page(page);
782 		}
783 		offset[1] = 0;
784 		offset[0]++;
785 		nofs += err;
786 	}
787 fail:
788 	f2fs_put_page(page, 0);
789 	trace_f2fs_truncate_inode_blocks_exit(inode, err);
790 	return err > 0 ? 0 : err;
791 }
792 
793 int truncate_xattr_node(struct inode *inode, struct page *page)
794 {
795 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
796 	nid_t nid = F2FS_I(inode)->i_xattr_nid;
797 	struct dnode_of_data dn;
798 	struct page *npage;
799 
800 	if (!nid)
801 		return 0;
802 
803 	npage = get_node_page(sbi, nid);
804 	if (IS_ERR(npage))
805 		return PTR_ERR(npage);
806 
807 	F2FS_I(inode)->i_xattr_nid = 0;
808 
809 	/* need to do checkpoint during fsync */
810 	F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
811 
812 	set_new_dnode(&dn, inode, page, npage, nid);
813 
814 	if (page)
815 		dn.inode_page_locked = true;
816 	truncate_node(&dn);
817 	return 0;
818 }
819 
820 /*
821  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
822  * f2fs_unlock_op().
823  */
824 void remove_inode_page(struct inode *inode)
825 {
826 	struct dnode_of_data dn;
827 
828 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
829 	if (get_dnode_of_data(&dn, 0, LOOKUP_NODE))
830 		return;
831 
832 	if (truncate_xattr_node(inode, dn.inode_page)) {
833 		f2fs_put_dnode(&dn);
834 		return;
835 	}
836 
837 	/* remove potential inline_data blocks */
838 	if (S_ISREG(inode->i_mode) || S_ISDIR(inode->i_mode) ||
839 				S_ISLNK(inode->i_mode))
840 		truncate_data_blocks_range(&dn, 1);
841 
842 	/* 0 is possible, after f2fs_new_inode() has failed */
843 	f2fs_bug_on(inode->i_blocks != 0 && inode->i_blocks != 1);
844 
845 	/* will put inode & node pages */
846 	truncate_node(&dn);
847 }
848 
849 struct page *new_inode_page(struct inode *inode)
850 {
851 	struct dnode_of_data dn;
852 
853 	/* allocate inode page for new inode */
854 	set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
855 
856 	/* caller should f2fs_put_page(page, 1); */
857 	return new_node_page(&dn, 0, NULL);
858 }
859 
860 struct page *new_node_page(struct dnode_of_data *dn,
861 				unsigned int ofs, struct page *ipage)
862 {
863 	struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
864 	struct node_info old_ni, new_ni;
865 	struct page *page;
866 	int err;
867 
868 	if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
869 		return ERR_PTR(-EPERM);
870 
871 	page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
872 	if (!page)
873 		return ERR_PTR(-ENOMEM);
874 
875 	if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
876 		err = -ENOSPC;
877 		goto fail;
878 	}
879 
880 	get_node_info(sbi, dn->nid, &old_ni);
881 
882 	/* Reinitialize old_ni with new node page */
883 	f2fs_bug_on(old_ni.blk_addr != NULL_ADDR);
884 	new_ni = old_ni;
885 	new_ni.ino = dn->inode->i_ino;
886 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
887 
888 	f2fs_wait_on_page_writeback(page, NODE);
889 	fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
890 	set_cold_node(dn->inode, page);
891 	SetPageUptodate(page);
892 	set_page_dirty(page);
893 
894 	if (f2fs_has_xattr_block(ofs))
895 		F2FS_I(dn->inode)->i_xattr_nid = dn->nid;
896 
897 	dn->node_page = page;
898 	if (ipage)
899 		update_inode(dn->inode, ipage);
900 	else
901 		sync_inode_page(dn);
902 	if (ofs == 0)
903 		inc_valid_inode_count(sbi);
904 
905 	return page;
906 
907 fail:
908 	clear_node_page_dirty(page);
909 	f2fs_put_page(page, 1);
910 	return ERR_PTR(err);
911 }
912 
913 /*
914  * Caller should do after getting the following values.
915  * 0: f2fs_put_page(page, 0)
916  * LOCKED_PAGE: f2fs_put_page(page, 1)
917  * error: nothing
918  */
919 static int read_node_page(struct page *page, int rw)
920 {
921 	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
922 	struct node_info ni;
923 
924 	get_node_info(sbi, page->index, &ni);
925 
926 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
927 		f2fs_put_page(page, 1);
928 		return -ENOENT;
929 	}
930 
931 	if (PageUptodate(page))
932 		return LOCKED_PAGE;
933 
934 	return f2fs_submit_page_bio(sbi, page, ni.blk_addr, rw);
935 }
936 
937 /*
938  * Readahead a node page
939  */
940 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
941 {
942 	struct page *apage;
943 	int err;
944 
945 	apage = find_get_page(NODE_MAPPING(sbi), nid);
946 	if (apage && PageUptodate(apage)) {
947 		f2fs_put_page(apage, 0);
948 		return;
949 	}
950 	f2fs_put_page(apage, 0);
951 
952 	apage = grab_cache_page(NODE_MAPPING(sbi), nid);
953 	if (!apage)
954 		return;
955 
956 	err = read_node_page(apage, READA);
957 	if (err == 0)
958 		f2fs_put_page(apage, 0);
959 	else if (err == LOCKED_PAGE)
960 		f2fs_put_page(apage, 1);
961 }
962 
963 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
964 {
965 	struct page *page;
966 	int err;
967 repeat:
968 	page = grab_cache_page(NODE_MAPPING(sbi), nid);
969 	if (!page)
970 		return ERR_PTR(-ENOMEM);
971 
972 	err = read_node_page(page, READ_SYNC);
973 	if (err < 0)
974 		return ERR_PTR(err);
975 	else if (err == LOCKED_PAGE)
976 		goto got_it;
977 
978 	lock_page(page);
979 	if (unlikely(!PageUptodate(page) || nid != nid_of_node(page))) {
980 		f2fs_put_page(page, 1);
981 		return ERR_PTR(-EIO);
982 	}
983 	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
984 		f2fs_put_page(page, 1);
985 		goto repeat;
986 	}
987 got_it:
988 	return page;
989 }
990 
991 /*
992  * Return a locked page for the desired node page.
993  * And, readahead MAX_RA_NODE number of node pages.
994  */
995 struct page *get_node_page_ra(struct page *parent, int start)
996 {
997 	struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
998 	struct blk_plug plug;
999 	struct page *page;
1000 	int err, i, end;
1001 	nid_t nid;
1002 
1003 	/* First, try getting the desired direct node. */
1004 	nid = get_nid(parent, start, false);
1005 	if (!nid)
1006 		return ERR_PTR(-ENOENT);
1007 repeat:
1008 	page = grab_cache_page(NODE_MAPPING(sbi), nid);
1009 	if (!page)
1010 		return ERR_PTR(-ENOMEM);
1011 
1012 	err = read_node_page(page, READ_SYNC);
1013 	if (err < 0)
1014 		return ERR_PTR(err);
1015 	else if (err == LOCKED_PAGE)
1016 		goto page_hit;
1017 
1018 	blk_start_plug(&plug);
1019 
1020 	/* Then, try readahead for siblings of the desired node */
1021 	end = start + MAX_RA_NODE;
1022 	end = min(end, NIDS_PER_BLOCK);
1023 	for (i = start + 1; i < end; i++) {
1024 		nid = get_nid(parent, i, false);
1025 		if (!nid)
1026 			continue;
1027 		ra_node_page(sbi, nid);
1028 	}
1029 
1030 	blk_finish_plug(&plug);
1031 
1032 	lock_page(page);
1033 	if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1034 		f2fs_put_page(page, 1);
1035 		goto repeat;
1036 	}
1037 page_hit:
1038 	if (unlikely(!PageUptodate(page))) {
1039 		f2fs_put_page(page, 1);
1040 		return ERR_PTR(-EIO);
1041 	}
1042 	return page;
1043 }
1044 
1045 void sync_inode_page(struct dnode_of_data *dn)
1046 {
1047 	if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
1048 		update_inode(dn->inode, dn->node_page);
1049 	} else if (dn->inode_page) {
1050 		if (!dn->inode_page_locked)
1051 			lock_page(dn->inode_page);
1052 		update_inode(dn->inode, dn->inode_page);
1053 		if (!dn->inode_page_locked)
1054 			unlock_page(dn->inode_page);
1055 	} else {
1056 		update_inode_page(dn->inode);
1057 	}
1058 }
1059 
1060 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
1061 					struct writeback_control *wbc)
1062 {
1063 	pgoff_t index, end;
1064 	struct pagevec pvec;
1065 	int step = ino ? 2 : 0;
1066 	int nwritten = 0, wrote = 0;
1067 
1068 	pagevec_init(&pvec, 0);
1069 
1070 next_step:
1071 	index = 0;
1072 	end = LONG_MAX;
1073 
1074 	while (index <= end) {
1075 		int i, nr_pages;
1076 		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1077 				PAGECACHE_TAG_DIRTY,
1078 				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1079 		if (nr_pages == 0)
1080 			break;
1081 
1082 		for (i = 0; i < nr_pages; i++) {
1083 			struct page *page = pvec.pages[i];
1084 
1085 			/*
1086 			 * flushing sequence with step:
1087 			 * 0. indirect nodes
1088 			 * 1. dentry dnodes
1089 			 * 2. file dnodes
1090 			 */
1091 			if (step == 0 && IS_DNODE(page))
1092 				continue;
1093 			if (step == 1 && (!IS_DNODE(page) ||
1094 						is_cold_node(page)))
1095 				continue;
1096 			if (step == 2 && (!IS_DNODE(page) ||
1097 						!is_cold_node(page)))
1098 				continue;
1099 
1100 			/*
1101 			 * If an fsync mode,
1102 			 * we should not skip writing node pages.
1103 			 */
1104 			if (ino && ino_of_node(page) == ino)
1105 				lock_page(page);
1106 			else if (!trylock_page(page))
1107 				continue;
1108 
1109 			if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1110 continue_unlock:
1111 				unlock_page(page);
1112 				continue;
1113 			}
1114 			if (ino && ino_of_node(page) != ino)
1115 				goto continue_unlock;
1116 
1117 			if (!PageDirty(page)) {
1118 				/* someone wrote it for us */
1119 				goto continue_unlock;
1120 			}
1121 
1122 			if (!clear_page_dirty_for_io(page))
1123 				goto continue_unlock;
1124 
1125 			/* called by fsync() */
1126 			if (ino && IS_DNODE(page)) {
1127 				int mark = !is_checkpointed_node(sbi, ino);
1128 				set_fsync_mark(page, 1);
1129 				if (IS_INODE(page))
1130 					set_dentry_mark(page, mark);
1131 				nwritten++;
1132 			} else {
1133 				set_fsync_mark(page, 0);
1134 				set_dentry_mark(page, 0);
1135 			}
1136 
1137 			if (NODE_MAPPING(sbi)->a_ops->writepage(page, wbc))
1138 				unlock_page(page);
1139 			else
1140 				wrote++;
1141 
1142 			if (--wbc->nr_to_write == 0)
1143 				break;
1144 		}
1145 		pagevec_release(&pvec);
1146 		cond_resched();
1147 
1148 		if (wbc->nr_to_write == 0) {
1149 			step = 2;
1150 			break;
1151 		}
1152 	}
1153 
1154 	if (step < 2) {
1155 		step++;
1156 		goto next_step;
1157 	}
1158 
1159 	if (wrote)
1160 		f2fs_submit_merged_bio(sbi, NODE, WRITE);
1161 	return nwritten;
1162 }
1163 
1164 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
1165 {
1166 	pgoff_t index = 0, end = LONG_MAX;
1167 	struct pagevec pvec;
1168 	int ret2 = 0, ret = 0;
1169 
1170 	pagevec_init(&pvec, 0);
1171 
1172 	while (index <= end) {
1173 		int i, nr_pages;
1174 		nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1175 				PAGECACHE_TAG_WRITEBACK,
1176 				min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1177 		if (nr_pages == 0)
1178 			break;
1179 
1180 		for (i = 0; i < nr_pages; i++) {
1181 			struct page *page = pvec.pages[i];
1182 
1183 			/* until radix tree lookup accepts end_index */
1184 			if (unlikely(page->index > end))
1185 				continue;
1186 
1187 			if (ino && ino_of_node(page) == ino) {
1188 				f2fs_wait_on_page_writeback(page, NODE);
1189 				if (TestClearPageError(page))
1190 					ret = -EIO;
1191 			}
1192 		}
1193 		pagevec_release(&pvec);
1194 		cond_resched();
1195 	}
1196 
1197 	if (unlikely(test_and_clear_bit(AS_ENOSPC, &NODE_MAPPING(sbi)->flags)))
1198 		ret2 = -ENOSPC;
1199 	if (unlikely(test_and_clear_bit(AS_EIO, &NODE_MAPPING(sbi)->flags)))
1200 		ret2 = -EIO;
1201 	if (!ret)
1202 		ret = ret2;
1203 	return ret;
1204 }
1205 
1206 static int f2fs_write_node_page(struct page *page,
1207 				struct writeback_control *wbc)
1208 {
1209 	struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
1210 	nid_t nid;
1211 	block_t new_addr;
1212 	struct node_info ni;
1213 	struct f2fs_io_info fio = {
1214 		.type = NODE,
1215 		.rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1216 	};
1217 
1218 	trace_f2fs_writepage(page, NODE);
1219 
1220 	if (unlikely(sbi->por_doing))
1221 		goto redirty_out;
1222 	if (unlikely(f2fs_cp_error(sbi)))
1223 		goto redirty_out;
1224 
1225 	f2fs_wait_on_page_writeback(page, NODE);
1226 
1227 	/* get old block addr of this node page */
1228 	nid = nid_of_node(page);
1229 	f2fs_bug_on(page->index != nid);
1230 
1231 	get_node_info(sbi, nid, &ni);
1232 
1233 	/* This page is already truncated */
1234 	if (unlikely(ni.blk_addr == NULL_ADDR)) {
1235 		dec_page_count(sbi, F2FS_DIRTY_NODES);
1236 		unlock_page(page);
1237 		return 0;
1238 	}
1239 
1240 	if (wbc->for_reclaim)
1241 		goto redirty_out;
1242 
1243 	down_read(&sbi->node_write);
1244 	set_page_writeback(page);
1245 	write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
1246 	set_node_addr(sbi, &ni, new_addr, is_fsync_dnode(page));
1247 	dec_page_count(sbi, F2FS_DIRTY_NODES);
1248 	up_read(&sbi->node_write);
1249 	unlock_page(page);
1250 	return 0;
1251 
1252 redirty_out:
1253 	redirty_page_for_writepage(wbc, page);
1254 	return AOP_WRITEPAGE_ACTIVATE;
1255 }
1256 
1257 static int f2fs_write_node_pages(struct address_space *mapping,
1258 			    struct writeback_control *wbc)
1259 {
1260 	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1261 	long diff;
1262 
1263 	trace_f2fs_writepages(mapping->host, wbc, NODE);
1264 
1265 	/* balancing f2fs's metadata in background */
1266 	f2fs_balance_fs_bg(sbi);
1267 
1268 	/* collect a number of dirty node pages and write together */
1269 	if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
1270 		goto skip_write;
1271 
1272 	diff = nr_pages_to_write(sbi, NODE, wbc);
1273 	wbc->sync_mode = WB_SYNC_NONE;
1274 	sync_node_pages(sbi, 0, wbc);
1275 	wbc->nr_to_write = max((long)0, wbc->nr_to_write - diff);
1276 	return 0;
1277 
1278 skip_write:
1279 	wbc->pages_skipped += get_pages(sbi, F2FS_DIRTY_NODES);
1280 	return 0;
1281 }
1282 
1283 static int f2fs_set_node_page_dirty(struct page *page)
1284 {
1285 	struct address_space *mapping = page->mapping;
1286 	struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1287 
1288 	trace_f2fs_set_page_dirty(page, NODE);
1289 
1290 	SetPageUptodate(page);
1291 	if (!PageDirty(page)) {
1292 		__set_page_dirty_nobuffers(page);
1293 		inc_page_count(sbi, F2FS_DIRTY_NODES);
1294 		SetPagePrivate(page);
1295 		return 1;
1296 	}
1297 	return 0;
1298 }
1299 
1300 static void f2fs_invalidate_node_page(struct page *page, unsigned int offset,
1301 				      unsigned int length)
1302 {
1303 	struct inode *inode = page->mapping->host;
1304 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1305 	if (PageDirty(page))
1306 		dec_page_count(sbi, F2FS_DIRTY_NODES);
1307 	ClearPagePrivate(page);
1308 }
1309 
1310 static int f2fs_release_node_page(struct page *page, gfp_t wait)
1311 {
1312 	ClearPagePrivate(page);
1313 	return 1;
1314 }
1315 
1316 /*
1317  * Structure of the f2fs node operations
1318  */
1319 const struct address_space_operations f2fs_node_aops = {
1320 	.writepage	= f2fs_write_node_page,
1321 	.writepages	= f2fs_write_node_pages,
1322 	.set_page_dirty	= f2fs_set_node_page_dirty,
1323 	.invalidatepage	= f2fs_invalidate_node_page,
1324 	.releasepage	= f2fs_release_node_page,
1325 };
1326 
1327 static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
1328 						nid_t n)
1329 {
1330 	return radix_tree_lookup(&nm_i->free_nid_root, n);
1331 }
1332 
1333 static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
1334 						struct free_nid *i)
1335 {
1336 	list_del(&i->list);
1337 	radix_tree_delete(&nm_i->free_nid_root, i->nid);
1338 }
1339 
1340 static int add_free_nid(struct f2fs_sb_info *sbi, nid_t nid, bool build)
1341 {
1342 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1343 	struct free_nid *i;
1344 	struct nat_entry *ne;
1345 	bool allocated = false;
1346 
1347 	if (!available_free_memory(sbi, FREE_NIDS))
1348 		return -1;
1349 
1350 	/* 0 nid should not be used */
1351 	if (unlikely(nid == 0))
1352 		return 0;
1353 
1354 	if (build) {
1355 		/* do not add allocated nids */
1356 		read_lock(&nm_i->nat_tree_lock);
1357 		ne = __lookup_nat_cache(nm_i, nid);
1358 		if (ne &&
1359 			(!ne->checkpointed || nat_get_blkaddr(ne) != NULL_ADDR))
1360 			allocated = true;
1361 		read_unlock(&nm_i->nat_tree_lock);
1362 		if (allocated)
1363 			return 0;
1364 	}
1365 
1366 	i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
1367 	i->nid = nid;
1368 	i->state = NID_NEW;
1369 
1370 	spin_lock(&nm_i->free_nid_list_lock);
1371 	if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
1372 		spin_unlock(&nm_i->free_nid_list_lock);
1373 		kmem_cache_free(free_nid_slab, i);
1374 		return 0;
1375 	}
1376 	list_add_tail(&i->list, &nm_i->free_nid_list);
1377 	nm_i->fcnt++;
1378 	spin_unlock(&nm_i->free_nid_list_lock);
1379 	return 1;
1380 }
1381 
1382 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1383 {
1384 	struct free_nid *i;
1385 	bool need_free = false;
1386 
1387 	spin_lock(&nm_i->free_nid_list_lock);
1388 	i = __lookup_free_nid_list(nm_i, nid);
1389 	if (i && i->state == NID_NEW) {
1390 		__del_from_free_nid_list(nm_i, i);
1391 		nm_i->fcnt--;
1392 		need_free = true;
1393 	}
1394 	spin_unlock(&nm_i->free_nid_list_lock);
1395 
1396 	if (need_free)
1397 		kmem_cache_free(free_nid_slab, i);
1398 }
1399 
1400 static void scan_nat_page(struct f2fs_sb_info *sbi,
1401 			struct page *nat_page, nid_t start_nid)
1402 {
1403 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1404 	struct f2fs_nat_block *nat_blk = page_address(nat_page);
1405 	block_t blk_addr;
1406 	int i;
1407 
1408 	i = start_nid % NAT_ENTRY_PER_BLOCK;
1409 
1410 	for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
1411 
1412 		if (unlikely(start_nid >= nm_i->max_nid))
1413 			break;
1414 
1415 		blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
1416 		f2fs_bug_on(blk_addr == NEW_ADDR);
1417 		if (blk_addr == NULL_ADDR) {
1418 			if (add_free_nid(sbi, start_nid, true) < 0)
1419 				break;
1420 		}
1421 	}
1422 }
1423 
1424 static void build_free_nids(struct f2fs_sb_info *sbi)
1425 {
1426 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1427 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1428 	struct f2fs_summary_block *sum = curseg->sum_blk;
1429 	int i = 0;
1430 	nid_t nid = nm_i->next_scan_nid;
1431 
1432 	/* Enough entries */
1433 	if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
1434 		return;
1435 
1436 	/* readahead nat pages to be scanned */
1437 	ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
1438 
1439 	while (1) {
1440 		struct page *page = get_current_nat_page(sbi, nid);
1441 
1442 		scan_nat_page(sbi, page, nid);
1443 		f2fs_put_page(page, 1);
1444 
1445 		nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
1446 		if (unlikely(nid >= nm_i->max_nid))
1447 			nid = 0;
1448 
1449 		if (i++ == FREE_NID_PAGES)
1450 			break;
1451 	}
1452 
1453 	/* go to the next free nat pages to find free nids abundantly */
1454 	nm_i->next_scan_nid = nid;
1455 
1456 	/* find free nids from current sum_pages */
1457 	mutex_lock(&curseg->curseg_mutex);
1458 	for (i = 0; i < nats_in_cursum(sum); i++) {
1459 		block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
1460 		nid = le32_to_cpu(nid_in_journal(sum, i));
1461 		if (addr == NULL_ADDR)
1462 			add_free_nid(sbi, nid, true);
1463 		else
1464 			remove_free_nid(nm_i, nid);
1465 	}
1466 	mutex_unlock(&curseg->curseg_mutex);
1467 }
1468 
1469 /*
1470  * If this function returns success, caller can obtain a new nid
1471  * from second parameter of this function.
1472  * The returned nid could be used ino as well as nid when inode is created.
1473  */
1474 bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
1475 {
1476 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1477 	struct free_nid *i = NULL;
1478 retry:
1479 	if (unlikely(sbi->total_valid_node_count + 1 > nm_i->available_nids))
1480 		return false;
1481 
1482 	spin_lock(&nm_i->free_nid_list_lock);
1483 
1484 	/* We should not use stale free nids created by build_free_nids */
1485 	if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
1486 		f2fs_bug_on(list_empty(&nm_i->free_nid_list));
1487 		list_for_each_entry(i, &nm_i->free_nid_list, list)
1488 			if (i->state == NID_NEW)
1489 				break;
1490 
1491 		f2fs_bug_on(i->state != NID_NEW);
1492 		*nid = i->nid;
1493 		i->state = NID_ALLOC;
1494 		nm_i->fcnt--;
1495 		spin_unlock(&nm_i->free_nid_list_lock);
1496 		return true;
1497 	}
1498 	spin_unlock(&nm_i->free_nid_list_lock);
1499 
1500 	/* Let's scan nat pages and its caches to get free nids */
1501 	mutex_lock(&nm_i->build_lock);
1502 	build_free_nids(sbi);
1503 	mutex_unlock(&nm_i->build_lock);
1504 	goto retry;
1505 }
1506 
1507 /*
1508  * alloc_nid() should be called prior to this function.
1509  */
1510 void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
1511 {
1512 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1513 	struct free_nid *i;
1514 
1515 	spin_lock(&nm_i->free_nid_list_lock);
1516 	i = __lookup_free_nid_list(nm_i, nid);
1517 	f2fs_bug_on(!i || i->state != NID_ALLOC);
1518 	__del_from_free_nid_list(nm_i, i);
1519 	spin_unlock(&nm_i->free_nid_list_lock);
1520 
1521 	kmem_cache_free(free_nid_slab, i);
1522 }
1523 
1524 /*
1525  * alloc_nid() should be called prior to this function.
1526  */
1527 void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
1528 {
1529 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1530 	struct free_nid *i;
1531 	bool need_free = false;
1532 
1533 	if (!nid)
1534 		return;
1535 
1536 	spin_lock(&nm_i->free_nid_list_lock);
1537 	i = __lookup_free_nid_list(nm_i, nid);
1538 	f2fs_bug_on(!i || i->state != NID_ALLOC);
1539 	if (!available_free_memory(sbi, FREE_NIDS)) {
1540 		__del_from_free_nid_list(nm_i, i);
1541 		need_free = true;
1542 	} else {
1543 		i->state = NID_NEW;
1544 		nm_i->fcnt++;
1545 	}
1546 	spin_unlock(&nm_i->free_nid_list_lock);
1547 
1548 	if (need_free)
1549 		kmem_cache_free(free_nid_slab, i);
1550 }
1551 
1552 void recover_inline_xattr(struct inode *inode, struct page *page)
1553 {
1554 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1555 	void *src_addr, *dst_addr;
1556 	size_t inline_size;
1557 	struct page *ipage;
1558 	struct f2fs_inode *ri;
1559 
1560 	ipage = get_node_page(sbi, inode->i_ino);
1561 	f2fs_bug_on(IS_ERR(ipage));
1562 
1563 	ri = F2FS_INODE(page);
1564 	if (!(ri->i_inline & F2FS_INLINE_XATTR)) {
1565 		clear_inode_flag(F2FS_I(inode), FI_INLINE_XATTR);
1566 		goto update_inode;
1567 	}
1568 
1569 	dst_addr = inline_xattr_addr(ipage);
1570 	src_addr = inline_xattr_addr(page);
1571 	inline_size = inline_xattr_size(inode);
1572 
1573 	f2fs_wait_on_page_writeback(ipage, NODE);
1574 	memcpy(dst_addr, src_addr, inline_size);
1575 update_inode:
1576 	update_inode(inode, ipage);
1577 	f2fs_put_page(ipage, 1);
1578 }
1579 
1580 void recover_xattr_data(struct inode *inode, struct page *page, block_t blkaddr)
1581 {
1582 	struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1583 	nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
1584 	nid_t new_xnid = nid_of_node(page);
1585 	struct node_info ni;
1586 
1587 	/* 1: invalidate the previous xattr nid */
1588 	if (!prev_xnid)
1589 		goto recover_xnid;
1590 
1591 	/* Deallocate node address */
1592 	get_node_info(sbi, prev_xnid, &ni);
1593 	f2fs_bug_on(ni.blk_addr == NULL_ADDR);
1594 	invalidate_blocks(sbi, ni.blk_addr);
1595 	dec_valid_node_count(sbi, inode);
1596 	set_node_addr(sbi, &ni, NULL_ADDR, false);
1597 
1598 recover_xnid:
1599 	/* 2: allocate new xattr nid */
1600 	if (unlikely(!inc_valid_node_count(sbi, inode)))
1601 		f2fs_bug_on(1);
1602 
1603 	remove_free_nid(NM_I(sbi), new_xnid);
1604 	get_node_info(sbi, new_xnid, &ni);
1605 	ni.ino = inode->i_ino;
1606 	set_node_addr(sbi, &ni, NEW_ADDR, false);
1607 	F2FS_I(inode)->i_xattr_nid = new_xnid;
1608 
1609 	/* 3: update xattr blkaddr */
1610 	refresh_sit_entry(sbi, NEW_ADDR, blkaddr);
1611 	set_node_addr(sbi, &ni, blkaddr, false);
1612 
1613 	update_inode_page(inode);
1614 }
1615 
1616 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
1617 {
1618 	struct f2fs_inode *src, *dst;
1619 	nid_t ino = ino_of_node(page);
1620 	struct node_info old_ni, new_ni;
1621 	struct page *ipage;
1622 
1623 	get_node_info(sbi, ino, &old_ni);
1624 
1625 	if (unlikely(old_ni.blk_addr != NULL_ADDR))
1626 		return -EINVAL;
1627 
1628 	ipage = grab_cache_page(NODE_MAPPING(sbi), ino);
1629 	if (!ipage)
1630 		return -ENOMEM;
1631 
1632 	/* Should not use this inode from free nid list */
1633 	remove_free_nid(NM_I(sbi), ino);
1634 
1635 	SetPageUptodate(ipage);
1636 	fill_node_footer(ipage, ino, ino, 0, true);
1637 
1638 	src = F2FS_INODE(page);
1639 	dst = F2FS_INODE(ipage);
1640 
1641 	memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
1642 	dst->i_size = 0;
1643 	dst->i_blocks = cpu_to_le64(1);
1644 	dst->i_links = cpu_to_le32(1);
1645 	dst->i_xattr_nid = 0;
1646 	dst->i_inline = src->i_inline & F2FS_INLINE_XATTR;
1647 
1648 	new_ni = old_ni;
1649 	new_ni.ino = ino;
1650 
1651 	if (unlikely(!inc_valid_node_count(sbi, NULL)))
1652 		WARN_ON(1);
1653 	set_node_addr(sbi, &new_ni, NEW_ADDR, false);
1654 	inc_valid_inode_count(sbi);
1655 	set_page_dirty(ipage);
1656 	f2fs_put_page(ipage, 1);
1657 	return 0;
1658 }
1659 
1660 /*
1661  * ra_sum_pages() merge contiguous pages into one bio and submit.
1662  * these pre-read pages are allocated in bd_inode's mapping tree.
1663  */
1664 static int ra_sum_pages(struct f2fs_sb_info *sbi, struct page **pages,
1665 				int start, int nrpages)
1666 {
1667 	struct inode *inode = sbi->sb->s_bdev->bd_inode;
1668 	struct address_space *mapping = inode->i_mapping;
1669 	int i, page_idx = start;
1670 	struct f2fs_io_info fio = {
1671 		.type = META,
1672 		.rw = READ_SYNC | REQ_META | REQ_PRIO
1673 	};
1674 
1675 	for (i = 0; page_idx < start + nrpages; page_idx++, i++) {
1676 		/* alloc page in bd_inode for reading node summary info */
1677 		pages[i] = grab_cache_page(mapping, page_idx);
1678 		if (!pages[i])
1679 			break;
1680 		f2fs_submit_page_mbio(sbi, pages[i], page_idx, &fio);
1681 	}
1682 
1683 	f2fs_submit_merged_bio(sbi, META, READ);
1684 	return i;
1685 }
1686 
1687 int restore_node_summary(struct f2fs_sb_info *sbi,
1688 			unsigned int segno, struct f2fs_summary_block *sum)
1689 {
1690 	struct f2fs_node *rn;
1691 	struct f2fs_summary *sum_entry;
1692 	struct inode *inode = sbi->sb->s_bdev->bd_inode;
1693 	block_t addr;
1694 	int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
1695 	struct page *pages[bio_blocks];
1696 	int i, idx, last_offset, nrpages, err = 0;
1697 
1698 	/* scan the node segment */
1699 	last_offset = sbi->blocks_per_seg;
1700 	addr = START_BLOCK(sbi, segno);
1701 	sum_entry = &sum->entries[0];
1702 
1703 	for (i = 0; !err && i < last_offset; i += nrpages, addr += nrpages) {
1704 		nrpages = min(last_offset - i, bio_blocks);
1705 
1706 		/* readahead node pages */
1707 		nrpages = ra_sum_pages(sbi, pages, addr, nrpages);
1708 		if (!nrpages)
1709 			return -ENOMEM;
1710 
1711 		for (idx = 0; idx < nrpages; idx++) {
1712 			if (err)
1713 				goto skip;
1714 
1715 			lock_page(pages[idx]);
1716 			if (unlikely(!PageUptodate(pages[idx]))) {
1717 				err = -EIO;
1718 			} else {
1719 				rn = F2FS_NODE(pages[idx]);
1720 				sum_entry->nid = rn->footer.nid;
1721 				sum_entry->version = 0;
1722 				sum_entry->ofs_in_node = 0;
1723 				sum_entry++;
1724 			}
1725 			unlock_page(pages[idx]);
1726 skip:
1727 			page_cache_release(pages[idx]);
1728 		}
1729 
1730 		invalidate_mapping_pages(inode->i_mapping, addr,
1731 							addr + nrpages);
1732 	}
1733 	return err;
1734 }
1735 
1736 static struct nat_entry_set *grab_nat_entry_set(void)
1737 {
1738 	struct nat_entry_set *nes =
1739 			f2fs_kmem_cache_alloc(nat_entry_set_slab, GFP_ATOMIC);
1740 
1741 	nes->entry_cnt = 0;
1742 	INIT_LIST_HEAD(&nes->set_list);
1743 	INIT_LIST_HEAD(&nes->entry_list);
1744 	return nes;
1745 }
1746 
1747 static void release_nat_entry_set(struct nat_entry_set *nes,
1748 						struct f2fs_nm_info *nm_i)
1749 {
1750 	f2fs_bug_on(!list_empty(&nes->entry_list));
1751 
1752 	nm_i->dirty_nat_cnt -= nes->entry_cnt;
1753 	list_del(&nes->set_list);
1754 	kmem_cache_free(nat_entry_set_slab, nes);
1755 }
1756 
1757 static void adjust_nat_entry_set(struct nat_entry_set *nes,
1758 						struct list_head *head)
1759 {
1760 	struct nat_entry_set *next = nes;
1761 
1762 	if (list_is_last(&nes->set_list, head))
1763 		return;
1764 
1765 	list_for_each_entry_continue(next, head, set_list)
1766 		if (nes->entry_cnt <= next->entry_cnt)
1767 			break;
1768 
1769 	list_move_tail(&nes->set_list, &next->set_list);
1770 }
1771 
1772 static void add_nat_entry(struct nat_entry *ne, struct list_head *head)
1773 {
1774 	struct nat_entry_set *nes;
1775 	nid_t start_nid = START_NID(ne->ni.nid);
1776 
1777 	list_for_each_entry(nes, head, set_list) {
1778 		if (nes->start_nid == start_nid) {
1779 			list_move_tail(&ne->list, &nes->entry_list);
1780 			nes->entry_cnt++;
1781 			adjust_nat_entry_set(nes, head);
1782 			return;
1783 		}
1784 	}
1785 
1786 	nes = grab_nat_entry_set();
1787 
1788 	nes->start_nid = start_nid;
1789 	list_move_tail(&ne->list, &nes->entry_list);
1790 	nes->entry_cnt++;
1791 	list_add(&nes->set_list, head);
1792 }
1793 
1794 static void merge_nats_in_set(struct f2fs_sb_info *sbi)
1795 {
1796 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1797 	struct list_head *dirty_list = &nm_i->dirty_nat_entries;
1798 	struct list_head *set_list = &nm_i->nat_entry_set;
1799 	struct nat_entry *ne, *tmp;
1800 
1801 	write_lock(&nm_i->nat_tree_lock);
1802 	list_for_each_entry_safe(ne, tmp, dirty_list, list) {
1803 		if (nat_get_blkaddr(ne) == NEW_ADDR)
1804 			continue;
1805 		add_nat_entry(ne, set_list);
1806 		nm_i->dirty_nat_cnt++;
1807 	}
1808 	write_unlock(&nm_i->nat_tree_lock);
1809 }
1810 
1811 static bool __has_cursum_space(struct f2fs_summary_block *sum, int size)
1812 {
1813 	if (nats_in_cursum(sum) + size <= NAT_JOURNAL_ENTRIES)
1814 		return true;
1815 	else
1816 		return false;
1817 }
1818 
1819 static void remove_nats_in_journal(struct f2fs_sb_info *sbi)
1820 {
1821 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1822 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1823 	struct f2fs_summary_block *sum = curseg->sum_blk;
1824 	int i;
1825 
1826 	mutex_lock(&curseg->curseg_mutex);
1827 	for (i = 0; i < nats_in_cursum(sum); i++) {
1828 		struct nat_entry *ne;
1829 		struct f2fs_nat_entry raw_ne;
1830 		nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
1831 
1832 		raw_ne = nat_in_journal(sum, i);
1833 retry:
1834 		write_lock(&nm_i->nat_tree_lock);
1835 		ne = __lookup_nat_cache(nm_i, nid);
1836 		if (ne)
1837 			goto found;
1838 
1839 		ne = grab_nat_entry(nm_i, nid);
1840 		if (!ne) {
1841 			write_unlock(&nm_i->nat_tree_lock);
1842 			goto retry;
1843 		}
1844 		node_info_from_raw_nat(&ne->ni, &raw_ne);
1845 found:
1846 		__set_nat_cache_dirty(nm_i, ne);
1847 		write_unlock(&nm_i->nat_tree_lock);
1848 	}
1849 	update_nats_in_cursum(sum, -i);
1850 	mutex_unlock(&curseg->curseg_mutex);
1851 }
1852 
1853 /*
1854  * This function is called during the checkpointing process.
1855  */
1856 void flush_nat_entries(struct f2fs_sb_info *sbi)
1857 {
1858 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1859 	struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1860 	struct f2fs_summary_block *sum = curseg->sum_blk;
1861 	struct nat_entry_set *nes, *tmp;
1862 	struct list_head *head = &nm_i->nat_entry_set;
1863 	bool to_journal = true;
1864 
1865 	/* merge nat entries of dirty list to nat entry set temporarily */
1866 	merge_nats_in_set(sbi);
1867 
1868 	/*
1869 	 * if there are no enough space in journal to store dirty nat
1870 	 * entries, remove all entries from journal and merge them
1871 	 * into nat entry set.
1872 	 */
1873 	if (!__has_cursum_space(sum, nm_i->dirty_nat_cnt)) {
1874 		remove_nats_in_journal(sbi);
1875 
1876 		/*
1877 		 * merge nat entries of dirty list to nat entry set temporarily
1878 		 */
1879 		merge_nats_in_set(sbi);
1880 	}
1881 
1882 	if (!nm_i->dirty_nat_cnt)
1883 		return;
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 	list_for_each_entry_safe(nes, tmp, head, set_list) {
1891 		struct f2fs_nat_block *nat_blk;
1892 		struct nat_entry *ne, *cur;
1893 		struct page *page;
1894 		nid_t start_nid = nes->start_nid;
1895 
1896 		if (to_journal && !__has_cursum_space(sum, nes->entry_cnt))
1897 			to_journal = false;
1898 
1899 		if (to_journal) {
1900 			mutex_lock(&curseg->curseg_mutex);
1901 		} else {
1902 			page = get_next_nat_page(sbi, start_nid);
1903 			nat_blk = page_address(page);
1904 			f2fs_bug_on(!nat_blk);
1905 		}
1906 
1907 		/* flush dirty nats in nat entry set */
1908 		list_for_each_entry_safe(ne, cur, &nes->entry_list, list) {
1909 			struct f2fs_nat_entry *raw_ne;
1910 			nid_t nid = nat_get_nid(ne);
1911 			int offset;
1912 
1913 			if (to_journal) {
1914 				offset = lookup_journal_in_cursum(sum,
1915 							NAT_JOURNAL, nid, 1);
1916 				f2fs_bug_on(offset < 0);
1917 				raw_ne = &nat_in_journal(sum, offset);
1918 				nid_in_journal(sum, offset) = cpu_to_le32(nid);
1919 			} else {
1920 				raw_ne = &nat_blk->entries[nid - start_nid];
1921 			}
1922 			raw_nat_from_node_info(raw_ne, &ne->ni);
1923 
1924 			if (nat_get_blkaddr(ne) == NULL_ADDR &&
1925 				add_free_nid(sbi, nid, false) <= 0) {
1926 				write_lock(&nm_i->nat_tree_lock);
1927 				__del_from_nat_cache(nm_i, ne);
1928 				write_unlock(&nm_i->nat_tree_lock);
1929 			} else {
1930 				write_lock(&nm_i->nat_tree_lock);
1931 				__clear_nat_cache_dirty(nm_i, ne);
1932 				write_unlock(&nm_i->nat_tree_lock);
1933 			}
1934 		}
1935 
1936 		if (to_journal)
1937 			mutex_unlock(&curseg->curseg_mutex);
1938 		else
1939 			f2fs_put_page(page, 1);
1940 
1941 		release_nat_entry_set(nes, nm_i);
1942 	}
1943 
1944 	f2fs_bug_on(!list_empty(head));
1945 	f2fs_bug_on(nm_i->dirty_nat_cnt);
1946 }
1947 
1948 static int init_node_manager(struct f2fs_sb_info *sbi)
1949 {
1950 	struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
1951 	struct f2fs_nm_info *nm_i = NM_I(sbi);
1952 	unsigned char *version_bitmap;
1953 	unsigned int nat_segs, nat_blocks;
1954 
1955 	nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
1956 
1957 	/* segment_count_nat includes pair segment so divide to 2. */
1958 	nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
1959 	nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
1960 
1961 	nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks;
1962 
1963 	/* not used nids: 0, node, meta, (and root counted as valid node) */
1964 	nm_i->available_nids = nm_i->max_nid - F2FS_RESERVED_NODE_NUM;
1965 	nm_i->fcnt = 0;
1966 	nm_i->nat_cnt = 0;
1967 	nm_i->ram_thresh = DEF_RAM_THRESHOLD;
1968 
1969 	INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
1970 	INIT_LIST_HEAD(&nm_i->free_nid_list);
1971 	INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);
1972 	INIT_LIST_HEAD(&nm_i->nat_entries);
1973 	INIT_LIST_HEAD(&nm_i->dirty_nat_entries);
1974 	INIT_LIST_HEAD(&nm_i->nat_entry_set);
1975 
1976 	mutex_init(&nm_i->build_lock);
1977 	spin_lock_init(&nm_i->free_nid_list_lock);
1978 	rwlock_init(&nm_i->nat_tree_lock);
1979 
1980 	nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
1981 	nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
1982 	version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
1983 	if (!version_bitmap)
1984 		return -EFAULT;
1985 
1986 	nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
1987 					GFP_KERNEL);
1988 	if (!nm_i->nat_bitmap)
1989 		return -ENOMEM;
1990 	return 0;
1991 }
1992 
1993 int build_node_manager(struct f2fs_sb_info *sbi)
1994 {
1995 	int err;
1996 
1997 	sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
1998 	if (!sbi->nm_info)
1999 		return -ENOMEM;
2000 
2001 	err = init_node_manager(sbi);
2002 	if (err)
2003 		return err;
2004 
2005 	build_free_nids(sbi);
2006 	return 0;
2007 }
2008 
2009 void destroy_node_manager(struct f2fs_sb_info *sbi)
2010 {
2011 	struct f2fs_nm_info *nm_i = NM_I(sbi);
2012 	struct free_nid *i, *next_i;
2013 	struct nat_entry *natvec[NATVEC_SIZE];
2014 	nid_t nid = 0;
2015 	unsigned int found;
2016 
2017 	if (!nm_i)
2018 		return;
2019 
2020 	/* destroy free nid list */
2021 	spin_lock(&nm_i->free_nid_list_lock);
2022 	list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
2023 		f2fs_bug_on(i->state == NID_ALLOC);
2024 		__del_from_free_nid_list(nm_i, i);
2025 		nm_i->fcnt--;
2026 		spin_unlock(&nm_i->free_nid_list_lock);
2027 		kmem_cache_free(free_nid_slab, i);
2028 		spin_lock(&nm_i->free_nid_list_lock);
2029 	}
2030 	f2fs_bug_on(nm_i->fcnt);
2031 	spin_unlock(&nm_i->free_nid_list_lock);
2032 
2033 	/* destroy nat cache */
2034 	write_lock(&nm_i->nat_tree_lock);
2035 	while ((found = __gang_lookup_nat_cache(nm_i,
2036 					nid, NATVEC_SIZE, natvec))) {
2037 		unsigned idx;
2038 		nid = nat_get_nid(natvec[found - 1]) + 1;
2039 		for (idx = 0; idx < found; idx++)
2040 			__del_from_nat_cache(nm_i, natvec[idx]);
2041 	}
2042 	f2fs_bug_on(nm_i->nat_cnt);
2043 	write_unlock(&nm_i->nat_tree_lock);
2044 
2045 	kfree(nm_i->nat_bitmap);
2046 	sbi->nm_info = NULL;
2047 	kfree(nm_i);
2048 }
2049 
2050 int __init create_node_manager_caches(void)
2051 {
2052 	nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
2053 			sizeof(struct nat_entry));
2054 	if (!nat_entry_slab)
2055 		goto fail;
2056 
2057 	free_nid_slab = f2fs_kmem_cache_create("free_nid",
2058 			sizeof(struct free_nid));
2059 	if (!free_nid_slab)
2060 		goto destory_nat_entry;
2061 
2062 	nat_entry_set_slab = f2fs_kmem_cache_create("nat_entry_set",
2063 			sizeof(struct nat_entry_set));
2064 	if (!nat_entry_set_slab)
2065 		goto destory_free_nid;
2066 	return 0;
2067 
2068 destory_free_nid:
2069 	kmem_cache_destroy(free_nid_slab);
2070 destory_nat_entry:
2071 	kmem_cache_destroy(nat_entry_slab);
2072 fail:
2073 	return -ENOMEM;
2074 }
2075 
2076 void destroy_node_manager_caches(void)
2077 {
2078 	kmem_cache_destroy(nat_entry_set_slab);
2079 	kmem_cache_destroy(free_nid_slab);
2080 	kmem_cache_destroy(nat_entry_slab);
2081 }
2082