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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
29 static void clear_node_page_dirty(struct page *page)
30 {
31         struct address_space *mapping = page->mapping;
32         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
33         unsigned int long flags;
34
35         if (PageDirty(page)) {
36                 spin_lock_irqsave(&mapping->tree_lock, flags);
37                 radix_tree_tag_clear(&mapping->page_tree,
38                                 page_index(page),
39                                 PAGECACHE_TAG_DIRTY);
40                 spin_unlock_irqrestore(&mapping->tree_lock, flags);
41
42                 clear_page_dirty_for_io(page);
43                 dec_page_count(sbi, F2FS_DIRTY_NODES);
44         }
45         ClearPageUptodate(page);
46 }
47
48 static struct page *get_current_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
49 {
50         pgoff_t index = current_nat_addr(sbi, nid);
51         return get_meta_page(sbi, index);
52 }
53
54 static struct page *get_next_nat_page(struct f2fs_sb_info *sbi, nid_t nid)
55 {
56         struct page *src_page;
57         struct page *dst_page;
58         pgoff_t src_off;
59         pgoff_t dst_off;
60         void *src_addr;
61         void *dst_addr;
62         struct f2fs_nm_info *nm_i = NM_I(sbi);
63
64         src_off = current_nat_addr(sbi, nid);
65         dst_off = next_nat_addr(sbi, src_off);
66
67         /* get current nat block page with lock */
68         src_page = get_meta_page(sbi, src_off);
69
70         /* Dirty src_page means that it is already the new target NAT page. */
71         if (PageDirty(src_page))
72                 return src_page;
73
74         dst_page = grab_meta_page(sbi, dst_off);
75
76         src_addr = page_address(src_page);
77         dst_addr = page_address(dst_page);
78         memcpy(dst_addr, src_addr, PAGE_CACHE_SIZE);
79         set_page_dirty(dst_page);
80         f2fs_put_page(src_page, 1);
81
82         set_to_next_nat(nm_i, nid);
83
84         return dst_page;
85 }
86
87 static struct nat_entry *__lookup_nat_cache(struct f2fs_nm_info *nm_i, nid_t n)
88 {
89         return radix_tree_lookup(&nm_i->nat_root, n);
90 }
91
92 static unsigned int __gang_lookup_nat_cache(struct f2fs_nm_info *nm_i,
93                 nid_t start, unsigned int nr, struct nat_entry **ep)
94 {
95         return radix_tree_gang_lookup(&nm_i->nat_root, (void **)ep, start, nr);
96 }
97
98 static void __del_from_nat_cache(struct f2fs_nm_info *nm_i, struct nat_entry *e)
99 {
100         list_del(&e->list);
101         radix_tree_delete(&nm_i->nat_root, nat_get_nid(e));
102         nm_i->nat_cnt--;
103         kmem_cache_free(nat_entry_slab, e);
104 }
105
106 int is_checkpointed_node(struct f2fs_sb_info *sbi, nid_t nid)
107 {
108         struct f2fs_nm_info *nm_i = NM_I(sbi);
109         struct nat_entry *e;
110         int is_cp = 1;
111
112         read_lock(&nm_i->nat_tree_lock);
113         e = __lookup_nat_cache(nm_i, nid);
114         if (e && !e->checkpointed)
115                 is_cp = 0;
116         read_unlock(&nm_i->nat_tree_lock);
117         return is_cp;
118 }
119
120 static struct nat_entry *grab_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid)
121 {
122         struct nat_entry *new;
123
124         new = kmem_cache_alloc(nat_entry_slab, GFP_ATOMIC);
125         if (!new)
126                 return NULL;
127         if (radix_tree_insert(&nm_i->nat_root, nid, new)) {
128                 kmem_cache_free(nat_entry_slab, new);
129                 return NULL;
130         }
131         memset(new, 0, sizeof(struct nat_entry));
132         nat_set_nid(new, nid);
133         new->checkpointed = true;
134         list_add_tail(&new->list, &nm_i->nat_entries);
135         nm_i->nat_cnt++;
136         return new;
137 }
138
139 static void cache_nat_entry(struct f2fs_nm_info *nm_i, nid_t nid,
140                                                 struct f2fs_nat_entry *ne)
141 {
142         struct nat_entry *e;
143 retry:
144         write_lock(&nm_i->nat_tree_lock);
145         e = __lookup_nat_cache(nm_i, nid);
146         if (!e) {
147                 e = grab_nat_entry(nm_i, nid);
148                 if (!e) {
149                         write_unlock(&nm_i->nat_tree_lock);
150                         goto retry;
151                 }
152                 nat_set_blkaddr(e, le32_to_cpu(ne->block_addr));
153                 nat_set_ino(e, le32_to_cpu(ne->ino));
154                 nat_set_version(e, ne->version);
155         }
156         write_unlock(&nm_i->nat_tree_lock);
157 }
158
159 static void set_node_addr(struct f2fs_sb_info *sbi, struct node_info *ni,
160                         block_t new_blkaddr)
161 {
162         struct f2fs_nm_info *nm_i = NM_I(sbi);
163         struct nat_entry *e;
164 retry:
165         write_lock(&nm_i->nat_tree_lock);
166         e = __lookup_nat_cache(nm_i, ni->nid);
167         if (!e) {
168                 e = grab_nat_entry(nm_i, ni->nid);
169                 if (!e) {
170                         write_unlock(&nm_i->nat_tree_lock);
171                         goto retry;
172                 }
173                 e->ni = *ni;
174                 f2fs_bug_on(ni->blk_addr == NEW_ADDR);
175         } else if (new_blkaddr == NEW_ADDR) {
176                 /*
177                  * when nid is reallocated,
178                  * previous nat entry can be remained in nat cache.
179                  * So, reinitialize it with new information.
180                  */
181                 e->ni = *ni;
182                 f2fs_bug_on(ni->blk_addr != NULL_ADDR);
183         }
184
185         /* sanity check */
186         f2fs_bug_on(nat_get_blkaddr(e) != ni->blk_addr);
187         f2fs_bug_on(nat_get_blkaddr(e) == NULL_ADDR &&
188                         new_blkaddr == NULL_ADDR);
189         f2fs_bug_on(nat_get_blkaddr(e) == NEW_ADDR &&
190                         new_blkaddr == NEW_ADDR);
191         f2fs_bug_on(nat_get_blkaddr(e) != NEW_ADDR &&
192                         nat_get_blkaddr(e) != NULL_ADDR &&
193                         new_blkaddr == NEW_ADDR);
194
195         /* increament version no as node is removed */
196         if (nat_get_blkaddr(e) != NEW_ADDR && new_blkaddr == NULL_ADDR) {
197                 unsigned char version = nat_get_version(e);
198                 nat_set_version(e, inc_node_version(version));
199         }
200
201         /* change address */
202         nat_set_blkaddr(e, new_blkaddr);
203         __set_nat_cache_dirty(nm_i, e);
204         write_unlock(&nm_i->nat_tree_lock);
205 }
206
207 int try_to_free_nats(struct f2fs_sb_info *sbi, int nr_shrink)
208 {
209         struct f2fs_nm_info *nm_i = NM_I(sbi);
210
211         if (nm_i->nat_cnt <= NM_WOUT_THRESHOLD)
212                 return 0;
213
214         write_lock(&nm_i->nat_tree_lock);
215         while (nr_shrink && !list_empty(&nm_i->nat_entries)) {
216                 struct nat_entry *ne;
217                 ne = list_first_entry(&nm_i->nat_entries,
218                                         struct nat_entry, list);
219                 __del_from_nat_cache(nm_i, ne);
220                 nr_shrink--;
221         }
222         write_unlock(&nm_i->nat_tree_lock);
223         return nr_shrink;
224 }
225
226 /*
227  * This function returns always success
228  */
229 void get_node_info(struct f2fs_sb_info *sbi, nid_t nid, struct node_info *ni)
230 {
231         struct f2fs_nm_info *nm_i = NM_I(sbi);
232         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
233         struct f2fs_summary_block *sum = curseg->sum_blk;
234         nid_t start_nid = START_NID(nid);
235         struct f2fs_nat_block *nat_blk;
236         struct page *page = NULL;
237         struct f2fs_nat_entry ne;
238         struct nat_entry *e;
239         int i;
240
241         memset(&ne, 0, sizeof(struct f2fs_nat_entry));
242         ni->nid = nid;
243
244         /* Check nat cache */
245         read_lock(&nm_i->nat_tree_lock);
246         e = __lookup_nat_cache(nm_i, nid);
247         if (e) {
248                 ni->ino = nat_get_ino(e);
249                 ni->blk_addr = nat_get_blkaddr(e);
250                 ni->version = nat_get_version(e);
251         }
252         read_unlock(&nm_i->nat_tree_lock);
253         if (e)
254                 return;
255
256         /* Check current segment summary */
257         mutex_lock(&curseg->curseg_mutex);
258         i = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 0);
259         if (i >= 0) {
260                 ne = nat_in_journal(sum, i);
261                 node_info_from_raw_nat(ni, &ne);
262         }
263         mutex_unlock(&curseg->curseg_mutex);
264         if (i >= 0)
265                 goto cache;
266
267         /* Fill node_info from nat page */
268         page = get_current_nat_page(sbi, start_nid);
269         nat_blk = (struct f2fs_nat_block *)page_address(page);
270         ne = nat_blk->entries[nid - start_nid];
271         node_info_from_raw_nat(ni, &ne);
272         f2fs_put_page(page, 1);
273 cache:
274         /* cache nat entry */
275         cache_nat_entry(NM_I(sbi), nid, &ne);
276 }
277
278 /*
279  * The maximum depth is four.
280  * Offset[0] will have raw inode offset.
281  */
282 static int get_node_path(struct f2fs_inode_info *fi, long block,
283                                 int offset[4], unsigned int noffset[4])
284 {
285         const long direct_index = ADDRS_PER_INODE(fi);
286         const long direct_blks = ADDRS_PER_BLOCK;
287         const long dptrs_per_blk = NIDS_PER_BLOCK;
288         const long indirect_blks = ADDRS_PER_BLOCK * NIDS_PER_BLOCK;
289         const long dindirect_blks = indirect_blks * NIDS_PER_BLOCK;
290         int n = 0;
291         int level = 0;
292
293         noffset[0] = 0;
294
295         if (block < direct_index) {
296                 offset[n] = block;
297                 goto got;
298         }
299         block -= direct_index;
300         if (block < direct_blks) {
301                 offset[n++] = NODE_DIR1_BLOCK;
302                 noffset[n] = 1;
303                 offset[n] = block;
304                 level = 1;
305                 goto got;
306         }
307         block -= direct_blks;
308         if (block < direct_blks) {
309                 offset[n++] = NODE_DIR2_BLOCK;
310                 noffset[n] = 2;
311                 offset[n] = block;
312                 level = 1;
313                 goto got;
314         }
315         block -= direct_blks;
316         if (block < indirect_blks) {
317                 offset[n++] = NODE_IND1_BLOCK;
318                 noffset[n] = 3;
319                 offset[n++] = block / direct_blks;
320                 noffset[n] = 4 + offset[n - 1];
321                 offset[n] = block % direct_blks;
322                 level = 2;
323                 goto got;
324         }
325         block -= indirect_blks;
326         if (block < indirect_blks) {
327                 offset[n++] = NODE_IND2_BLOCK;
328                 noffset[n] = 4 + dptrs_per_blk;
329                 offset[n++] = block / direct_blks;
330                 noffset[n] = 5 + dptrs_per_blk + offset[n - 1];
331                 offset[n] = block % direct_blks;
332                 level = 2;
333                 goto got;
334         }
335         block -= indirect_blks;
336         if (block < dindirect_blks) {
337                 offset[n++] = NODE_DIND_BLOCK;
338                 noffset[n] = 5 + (dptrs_per_blk * 2);
339                 offset[n++] = block / indirect_blks;
340                 noffset[n] = 6 + (dptrs_per_blk * 2) +
341                               offset[n - 1] * (dptrs_per_blk + 1);
342                 offset[n++] = (block / direct_blks) % dptrs_per_blk;
343                 noffset[n] = 7 + (dptrs_per_blk * 2) +
344                               offset[n - 2] * (dptrs_per_blk + 1) +
345                               offset[n - 1];
346                 offset[n] = block % direct_blks;
347                 level = 3;
348                 goto got;
349         } else {
350                 BUG();
351         }
352 got:
353         return level;
354 }
355
356 /*
357  * Caller should call f2fs_put_dnode(dn).
358  * Also, it should grab and release a rwsem by calling f2fs_lock_op() and
359  * f2fs_unlock_op() only if ro is not set RDONLY_NODE.
360  * In the case of RDONLY_NODE, we don't need to care about mutex.
361  */
362 int get_dnode_of_data(struct dnode_of_data *dn, pgoff_t index, int mode)
363 {
364         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
365         struct page *npage[4];
366         struct page *parent;
367         int offset[4];
368         unsigned int noffset[4];
369         nid_t nids[4];
370         int level, i;
371         int err = 0;
372
373         level = get_node_path(F2FS_I(dn->inode), index, offset, noffset);
374
375         nids[0] = dn->inode->i_ino;
376         npage[0] = dn->inode_page;
377
378         if (!npage[0]) {
379                 npage[0] = get_node_page(sbi, nids[0]);
380                 if (IS_ERR(npage[0]))
381                         return PTR_ERR(npage[0]);
382         }
383         parent = npage[0];
384         if (level != 0)
385                 nids[1] = get_nid(parent, offset[0], true);
386         dn->inode_page = npage[0];
387         dn->inode_page_locked = true;
388
389         /* get indirect or direct nodes */
390         for (i = 1; i <= level; i++) {
391                 bool done = false;
392
393                 if (!nids[i] && mode == ALLOC_NODE) {
394                         /* alloc new node */
395                         if (!alloc_nid(sbi, &(nids[i]))) {
396                                 err = -ENOSPC;
397                                 goto release_pages;
398                         }
399
400                         dn->nid = nids[i];
401                         npage[i] = new_node_page(dn, noffset[i], NULL);
402                         if (IS_ERR(npage[i])) {
403                                 alloc_nid_failed(sbi, nids[i]);
404                                 err = PTR_ERR(npage[i]);
405                                 goto release_pages;
406                         }
407
408                         set_nid(parent, offset[i - 1], nids[i], i == 1);
409                         alloc_nid_done(sbi, nids[i]);
410                         done = true;
411                 } else if (mode == LOOKUP_NODE_RA && i == level && level > 1) {
412                         npage[i] = get_node_page_ra(parent, offset[i - 1]);
413                         if (IS_ERR(npage[i])) {
414                                 err = PTR_ERR(npage[i]);
415                                 goto release_pages;
416                         }
417                         done = true;
418                 }
419                 if (i == 1) {
420                         dn->inode_page_locked = false;
421                         unlock_page(parent);
422                 } else {
423                         f2fs_put_page(parent, 1);
424                 }
425
426                 if (!done) {
427                         npage[i] = get_node_page(sbi, nids[i]);
428                         if (IS_ERR(npage[i])) {
429                                 err = PTR_ERR(npage[i]);
430                                 f2fs_put_page(npage[0], 0);
431                                 goto release_out;
432                         }
433                 }
434                 if (i < level) {
435                         parent = npage[i];
436                         nids[i + 1] = get_nid(parent, offset[i], false);
437                 }
438         }
439         dn->nid = nids[level];
440         dn->ofs_in_node = offset[level];
441         dn->node_page = npage[level];
442         dn->data_blkaddr = datablock_addr(dn->node_page, dn->ofs_in_node);
443         return 0;
444
445 release_pages:
446         f2fs_put_page(parent, 1);
447         if (i > 1)
448                 f2fs_put_page(npage[0], 0);
449 release_out:
450         dn->inode_page = NULL;
451         dn->node_page = NULL;
452         return err;
453 }
454
455 static void truncate_node(struct dnode_of_data *dn)
456 {
457         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
458         struct node_info ni;
459
460         get_node_info(sbi, dn->nid, &ni);
461         if (dn->inode->i_blocks == 0) {
462                 f2fs_bug_on(ni.blk_addr != NULL_ADDR);
463                 goto invalidate;
464         }
465         f2fs_bug_on(ni.blk_addr == NULL_ADDR);
466
467         /* Deallocate node address */
468         invalidate_blocks(sbi, ni.blk_addr);
469         dec_valid_node_count(sbi, dn->inode);
470         set_node_addr(sbi, &ni, NULL_ADDR);
471
472         if (dn->nid == dn->inode->i_ino) {
473                 remove_orphan_inode(sbi, dn->nid);
474                 dec_valid_inode_count(sbi);
475         } else {
476                 sync_inode_page(dn);
477         }
478 invalidate:
479         clear_node_page_dirty(dn->node_page);
480         F2FS_SET_SB_DIRT(sbi);
481
482         f2fs_put_page(dn->node_page, 1);
483
484         invalidate_mapping_pages(NODE_MAPPING(sbi),
485                         dn->node_page->index, dn->node_page->index);
486
487         dn->node_page = NULL;
488         trace_f2fs_truncate_node(dn->inode, dn->nid, ni.blk_addr);
489 }
490
491 static int truncate_dnode(struct dnode_of_data *dn)
492 {
493         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
494         struct page *page;
495
496         if (dn->nid == 0)
497                 return 1;
498
499         /* get direct node */
500         page = get_node_page(sbi, dn->nid);
501         if (IS_ERR(page) && PTR_ERR(page) == -ENOENT)
502                 return 1;
503         else if (IS_ERR(page))
504                 return PTR_ERR(page);
505
506         /* Make dnode_of_data for parameter */
507         dn->node_page = page;
508         dn->ofs_in_node = 0;
509         truncate_data_blocks(dn);
510         truncate_node(dn);
511         return 1;
512 }
513
514 static int truncate_nodes(struct dnode_of_data *dn, unsigned int nofs,
515                                                 int ofs, int depth)
516 {
517         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
518         struct dnode_of_data rdn = *dn;
519         struct page *page;
520         struct f2fs_node *rn;
521         nid_t child_nid;
522         unsigned int child_nofs;
523         int freed = 0;
524         int i, ret;
525
526         if (dn->nid == 0)
527                 return NIDS_PER_BLOCK + 1;
528
529         trace_f2fs_truncate_nodes_enter(dn->inode, dn->nid, dn->data_blkaddr);
530
531         page = get_node_page(sbi, dn->nid);
532         if (IS_ERR(page)) {
533                 trace_f2fs_truncate_nodes_exit(dn->inode, PTR_ERR(page));
534                 return PTR_ERR(page);
535         }
536
537         rn = F2FS_NODE(page);
538         if (depth < 3) {
539                 for (i = ofs; i < NIDS_PER_BLOCK; i++, freed++) {
540                         child_nid = le32_to_cpu(rn->in.nid[i]);
541                         if (child_nid == 0)
542                                 continue;
543                         rdn.nid = child_nid;
544                         ret = truncate_dnode(&rdn);
545                         if (ret < 0)
546                                 goto out_err;
547                         set_nid(page, i, 0, false);
548                 }
549         } else {
550                 child_nofs = nofs + ofs * (NIDS_PER_BLOCK + 1) + 1;
551                 for (i = ofs; i < NIDS_PER_BLOCK; i++) {
552                         child_nid = le32_to_cpu(rn->in.nid[i]);
553                         if (child_nid == 0) {
554                                 child_nofs += NIDS_PER_BLOCK + 1;
555                                 continue;
556                         }
557                         rdn.nid = child_nid;
558                         ret = truncate_nodes(&rdn, child_nofs, 0, depth - 1);
559                         if (ret == (NIDS_PER_BLOCK + 1)) {
560                                 set_nid(page, i, 0, false);
561                                 child_nofs += ret;
562                         } else if (ret < 0 && ret != -ENOENT) {
563                                 goto out_err;
564                         }
565                 }
566                 freed = child_nofs;
567         }
568
569         if (!ofs) {
570                 /* remove current indirect node */
571                 dn->node_page = page;
572                 truncate_node(dn);
573                 freed++;
574         } else {
575                 f2fs_put_page(page, 1);
576         }
577         trace_f2fs_truncate_nodes_exit(dn->inode, freed);
578         return freed;
579
580 out_err:
581         f2fs_put_page(page, 1);
582         trace_f2fs_truncate_nodes_exit(dn->inode, ret);
583         return ret;
584 }
585
586 static int truncate_partial_nodes(struct dnode_of_data *dn,
587                         struct f2fs_inode *ri, int *offset, int depth)
588 {
589         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
590         struct page *pages[2];
591         nid_t nid[3];
592         nid_t child_nid;
593         int err = 0;
594         int i;
595         int idx = depth - 2;
596
597         nid[0] = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
598         if (!nid[0])
599                 return 0;
600
601         /* get indirect nodes in the path */
602         for (i = 0; i < idx + 1; i++) {
603                 /* refernece count'll be increased */
604                 pages[i] = get_node_page(sbi, nid[i]);
605                 if (IS_ERR(pages[i])) {
606                         err = PTR_ERR(pages[i]);
607                         idx = i - 1;
608                         goto fail;
609                 }
610                 nid[i + 1] = get_nid(pages[i], offset[i + 1], false);
611         }
612
613         /* free direct nodes linked to a partial indirect node */
614         for (i = offset[idx + 1]; i < NIDS_PER_BLOCK; i++) {
615                 child_nid = get_nid(pages[idx], i, false);
616                 if (!child_nid)
617                         continue;
618                 dn->nid = child_nid;
619                 err = truncate_dnode(dn);
620                 if (err < 0)
621                         goto fail;
622                 set_nid(pages[idx], i, 0, false);
623         }
624
625         if (offset[idx + 1] == 0) {
626                 dn->node_page = pages[idx];
627                 dn->nid = nid[idx];
628                 truncate_node(dn);
629         } else {
630                 f2fs_put_page(pages[idx], 1);
631         }
632         offset[idx]++;
633         offset[idx + 1] = 0;
634         idx--;
635 fail:
636         for (i = idx; i >= 0; i--)
637                 f2fs_put_page(pages[i], 1);
638
639         trace_f2fs_truncate_partial_nodes(dn->inode, nid, depth, err);
640
641         return err;
642 }
643
644 /*
645  * All the block addresses of data and nodes should be nullified.
646  */
647 int truncate_inode_blocks(struct inode *inode, pgoff_t from)
648 {
649         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
650         int err = 0, cont = 1;
651         int level, offset[4], noffset[4];
652         unsigned int nofs = 0;
653         struct f2fs_inode *ri;
654         struct dnode_of_data dn;
655         struct page *page;
656
657         trace_f2fs_truncate_inode_blocks_enter(inode, from);
658
659         level = get_node_path(F2FS_I(inode), from, offset, noffset);
660 restart:
661         page = get_node_page(sbi, inode->i_ino);
662         if (IS_ERR(page)) {
663                 trace_f2fs_truncate_inode_blocks_exit(inode, PTR_ERR(page));
664                 return PTR_ERR(page);
665         }
666
667         set_new_dnode(&dn, inode, page, NULL, 0);
668         unlock_page(page);
669
670         ri = F2FS_INODE(page);
671         switch (level) {
672         case 0:
673         case 1:
674                 nofs = noffset[1];
675                 break;
676         case 2:
677                 nofs = noffset[1];
678                 if (!offset[level - 1])
679                         goto skip_partial;
680                 err = truncate_partial_nodes(&dn, ri, offset, level);
681                 if (err < 0 && err != -ENOENT)
682                         goto fail;
683                 nofs += 1 + NIDS_PER_BLOCK;
684                 break;
685         case 3:
686                 nofs = 5 + 2 * NIDS_PER_BLOCK;
687                 if (!offset[level - 1])
688                         goto skip_partial;
689                 err = truncate_partial_nodes(&dn, ri, offset, level);
690                 if (err < 0 && err != -ENOENT)
691                         goto fail;
692                 break;
693         default:
694                 BUG();
695         }
696
697 skip_partial:
698         while (cont) {
699                 dn.nid = le32_to_cpu(ri->i_nid[offset[0] - NODE_DIR1_BLOCK]);
700                 switch (offset[0]) {
701                 case NODE_DIR1_BLOCK:
702                 case NODE_DIR2_BLOCK:
703                         err = truncate_dnode(&dn);
704                         break;
705
706                 case NODE_IND1_BLOCK:
707                 case NODE_IND2_BLOCK:
708                         err = truncate_nodes(&dn, nofs, offset[1], 2);
709                         break;
710
711                 case NODE_DIND_BLOCK:
712                         err = truncate_nodes(&dn, nofs, offset[1], 3);
713                         cont = 0;
714                         break;
715
716                 default:
717                         BUG();
718                 }
719                 if (err < 0 && err != -ENOENT)
720                         goto fail;
721                 if (offset[1] == 0 &&
722                                 ri->i_nid[offset[0] - NODE_DIR1_BLOCK]) {
723                         lock_page(page);
724                         if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
725                                 f2fs_put_page(page, 1);
726                                 goto restart;
727                         }
728                         wait_on_page_writeback(page);
729                         ri->i_nid[offset[0] - NODE_DIR1_BLOCK] = 0;
730                         set_page_dirty(page);
731                         unlock_page(page);
732                 }
733                 offset[1] = 0;
734                 offset[0]++;
735                 nofs += err;
736         }
737 fail:
738         f2fs_put_page(page, 0);
739         trace_f2fs_truncate_inode_blocks_exit(inode, err);
740         return err > 0 ? 0 : err;
741 }
742
743 int truncate_xattr_node(struct inode *inode, struct page *page)
744 {
745         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
746         nid_t nid = F2FS_I(inode)->i_xattr_nid;
747         struct dnode_of_data dn;
748         struct page *npage;
749
750         if (!nid)
751                 return 0;
752
753         npage = get_node_page(sbi, nid);
754         if (IS_ERR(npage))
755                 return PTR_ERR(npage);
756
757         F2FS_I(inode)->i_xattr_nid = 0;
758
759         /* need to do checkpoint during fsync */
760         F2FS_I(inode)->xattr_ver = cur_cp_version(F2FS_CKPT(sbi));
761
762         set_new_dnode(&dn, inode, page, npage, nid);
763
764         if (page)
765                 dn.inode_page_locked = true;
766         truncate_node(&dn);
767         return 0;
768 }
769
770 /*
771  * Caller should grab and release a rwsem by calling f2fs_lock_op() and
772  * f2fs_unlock_op().
773  */
774 void remove_inode_page(struct inode *inode)
775 {
776         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
777         struct page *page;
778         nid_t ino = inode->i_ino;
779         struct dnode_of_data dn;
780
781         page = get_node_page(sbi, ino);
782         if (IS_ERR(page))
783                 return;
784
785         if (truncate_xattr_node(inode, page)) {
786                 f2fs_put_page(page, 1);
787                 return;
788         }
789         /* 0 is possible, after f2fs_new_inode() is failed */
790         f2fs_bug_on(inode->i_blocks != 0 && inode->i_blocks != 1);
791         set_new_dnode(&dn, inode, page, page, ino);
792         truncate_node(&dn);
793 }
794
795 struct page *new_inode_page(struct inode *inode, const struct qstr *name)
796 {
797         struct dnode_of_data dn;
798
799         /* allocate inode page for new inode */
800         set_new_dnode(&dn, inode, NULL, NULL, inode->i_ino);
801
802         /* caller should f2fs_put_page(page, 1); */
803         return new_node_page(&dn, 0, NULL);
804 }
805
806 struct page *new_node_page(struct dnode_of_data *dn,
807                                 unsigned int ofs, struct page *ipage)
808 {
809         struct f2fs_sb_info *sbi = F2FS_SB(dn->inode->i_sb);
810         struct node_info old_ni, new_ni;
811         struct page *page;
812         int err;
813
814         if (unlikely(is_inode_flag_set(F2FS_I(dn->inode), FI_NO_ALLOC)))
815                 return ERR_PTR(-EPERM);
816
817         page = grab_cache_page(NODE_MAPPING(sbi), dn->nid);
818         if (!page)
819                 return ERR_PTR(-ENOMEM);
820
821         if (unlikely(!inc_valid_node_count(sbi, dn->inode))) {
822                 err = -ENOSPC;
823                 goto fail;
824         }
825
826         get_node_info(sbi, dn->nid, &old_ni);
827
828         /* Reinitialize old_ni with new node page */
829         f2fs_bug_on(old_ni.blk_addr != NULL_ADDR);
830         new_ni = old_ni;
831         new_ni.ino = dn->inode->i_ino;
832         set_node_addr(sbi, &new_ni, NEW_ADDR);
833
834         fill_node_footer(page, dn->nid, dn->inode->i_ino, ofs, true);
835         set_cold_node(dn->inode, page);
836         SetPageUptodate(page);
837         set_page_dirty(page);
838
839         if (f2fs_has_xattr_block(ofs))
840                 F2FS_I(dn->inode)->i_xattr_nid = dn->nid;
841
842         dn->node_page = page;
843         if (ipage)
844                 update_inode(dn->inode, ipage);
845         else
846                 sync_inode_page(dn);
847         if (ofs == 0)
848                 inc_valid_inode_count(sbi);
849
850         return page;
851
852 fail:
853         clear_node_page_dirty(page);
854         f2fs_put_page(page, 1);
855         return ERR_PTR(err);
856 }
857
858 /*
859  * Caller should do after getting the following values.
860  * 0: f2fs_put_page(page, 0)
861  * LOCKED_PAGE: f2fs_put_page(page, 1)
862  * error: nothing
863  */
864 static int read_node_page(struct page *page, int rw)
865 {
866         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
867         struct node_info ni;
868
869         get_node_info(sbi, page->index, &ni);
870
871         if (unlikely(ni.blk_addr == NULL_ADDR)) {
872                 f2fs_put_page(page, 1);
873                 return -ENOENT;
874         }
875
876         if (PageUptodate(page))
877                 return LOCKED_PAGE;
878
879         return f2fs_submit_page_bio(sbi, page, ni.blk_addr, rw);
880 }
881
882 /*
883  * Readahead a node page
884  */
885 void ra_node_page(struct f2fs_sb_info *sbi, nid_t nid)
886 {
887         struct page *apage;
888         int err;
889
890         apage = find_get_page(NODE_MAPPING(sbi), nid);
891         if (apage && PageUptodate(apage)) {
892                 f2fs_put_page(apage, 0);
893                 return;
894         }
895         f2fs_put_page(apage, 0);
896
897         apage = grab_cache_page(NODE_MAPPING(sbi), nid);
898         if (!apage)
899                 return;
900
901         err = read_node_page(apage, READA);
902         if (err == 0)
903                 f2fs_put_page(apage, 0);
904         else if (err == LOCKED_PAGE)
905                 f2fs_put_page(apage, 1);
906 }
907
908 struct page *get_node_page(struct f2fs_sb_info *sbi, pgoff_t nid)
909 {
910         struct page *page;
911         int err;
912 repeat:
913         page = grab_cache_page(NODE_MAPPING(sbi), nid);
914         if (!page)
915                 return ERR_PTR(-ENOMEM);
916
917         err = read_node_page(page, READ_SYNC);
918         if (err < 0)
919                 return ERR_PTR(err);
920         else if (err == LOCKED_PAGE)
921                 goto got_it;
922
923         lock_page(page);
924         if (unlikely(!PageUptodate(page))) {
925                 f2fs_put_page(page, 1);
926                 return ERR_PTR(-EIO);
927         }
928         if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
929                 f2fs_put_page(page, 1);
930                 goto repeat;
931         }
932 got_it:
933         f2fs_bug_on(nid != nid_of_node(page));
934         mark_page_accessed(page);
935         return page;
936 }
937
938 /*
939  * Return a locked page for the desired node page.
940  * And, readahead MAX_RA_NODE number of node pages.
941  */
942 struct page *get_node_page_ra(struct page *parent, int start)
943 {
944         struct f2fs_sb_info *sbi = F2FS_SB(parent->mapping->host->i_sb);
945         struct blk_plug plug;
946         struct page *page;
947         int err, i, end;
948         nid_t nid;
949
950         /* First, try getting the desired direct node. */
951         nid = get_nid(parent, start, false);
952         if (!nid)
953                 return ERR_PTR(-ENOENT);
954 repeat:
955         page = grab_cache_page(NODE_MAPPING(sbi), nid);
956         if (!page)
957                 return ERR_PTR(-ENOMEM);
958
959         err = read_node_page(page, READ_SYNC);
960         if (err < 0)
961                 return ERR_PTR(err);
962         else if (err == LOCKED_PAGE)
963                 goto page_hit;
964
965         blk_start_plug(&plug);
966
967         /* Then, try readahead for siblings of the desired node */
968         end = start + MAX_RA_NODE;
969         end = min(end, NIDS_PER_BLOCK);
970         for (i = start + 1; i < end; i++) {
971                 nid = get_nid(parent, i, false);
972                 if (!nid)
973                         continue;
974                 ra_node_page(sbi, nid);
975         }
976
977         blk_finish_plug(&plug);
978
979         lock_page(page);
980         if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
981                 f2fs_put_page(page, 1);
982                 goto repeat;
983         }
984 page_hit:
985         if (unlikely(!PageUptodate(page))) {
986                 f2fs_put_page(page, 1);
987                 return ERR_PTR(-EIO);
988         }
989         mark_page_accessed(page);
990         return page;
991 }
992
993 void sync_inode_page(struct dnode_of_data *dn)
994 {
995         if (IS_INODE(dn->node_page) || dn->inode_page == dn->node_page) {
996                 update_inode(dn->inode, dn->node_page);
997         } else if (dn->inode_page) {
998                 if (!dn->inode_page_locked)
999                         lock_page(dn->inode_page);
1000                 update_inode(dn->inode, dn->inode_page);
1001                 if (!dn->inode_page_locked)
1002                         unlock_page(dn->inode_page);
1003         } else {
1004                 update_inode_page(dn->inode);
1005         }
1006 }
1007
1008 int sync_node_pages(struct f2fs_sb_info *sbi, nid_t ino,
1009                                         struct writeback_control *wbc)
1010 {
1011         pgoff_t index, end;
1012         struct pagevec pvec;
1013         int step = ino ? 2 : 0;
1014         int nwritten = 0, wrote = 0;
1015
1016         pagevec_init(&pvec, 0);
1017
1018 next_step:
1019         index = 0;
1020         end = LONG_MAX;
1021
1022         while (index <= end) {
1023                 int i, nr_pages;
1024                 nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1025                                 PAGECACHE_TAG_DIRTY,
1026                                 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1027                 if (nr_pages == 0)
1028                         break;
1029
1030                 for (i = 0; i < nr_pages; i++) {
1031                         struct page *page = pvec.pages[i];
1032
1033                         /*
1034                          * flushing sequence with step:
1035                          * 0. indirect nodes
1036                          * 1. dentry dnodes
1037                          * 2. file dnodes
1038                          */
1039                         if (step == 0 && IS_DNODE(page))
1040                                 continue;
1041                         if (step == 1 && (!IS_DNODE(page) ||
1042                                                 is_cold_node(page)))
1043                                 continue;
1044                         if (step == 2 && (!IS_DNODE(page) ||
1045                                                 !is_cold_node(page)))
1046                                 continue;
1047
1048                         /*
1049                          * If an fsync mode,
1050                          * we should not skip writing node pages.
1051                          */
1052                         if (ino && ino_of_node(page) == ino)
1053                                 lock_page(page);
1054                         else if (!trylock_page(page))
1055                                 continue;
1056
1057                         if (unlikely(page->mapping != NODE_MAPPING(sbi))) {
1058 continue_unlock:
1059                                 unlock_page(page);
1060                                 continue;
1061                         }
1062                         if (ino && ino_of_node(page) != ino)
1063                                 goto continue_unlock;
1064
1065                         if (!PageDirty(page)) {
1066                                 /* someone wrote it for us */
1067                                 goto continue_unlock;
1068                         }
1069
1070                         if (!clear_page_dirty_for_io(page))
1071                                 goto continue_unlock;
1072
1073                         /* called by fsync() */
1074                         if (ino && IS_DNODE(page)) {
1075                                 int mark = !is_checkpointed_node(sbi, ino);
1076                                 set_fsync_mark(page, 1);
1077                                 if (IS_INODE(page))
1078                                         set_dentry_mark(page, mark);
1079                                 nwritten++;
1080                         } else {
1081                                 set_fsync_mark(page, 0);
1082                                 set_dentry_mark(page, 0);
1083                         }
1084                         NODE_MAPPING(sbi)->a_ops->writepage(page, wbc);
1085                         wrote++;
1086
1087                         if (--wbc->nr_to_write == 0)
1088                                 break;
1089                 }
1090                 pagevec_release(&pvec);
1091                 cond_resched();
1092
1093                 if (wbc->nr_to_write == 0) {
1094                         step = 2;
1095                         break;
1096                 }
1097         }
1098
1099         if (step < 2) {
1100                 step++;
1101                 goto next_step;
1102         }
1103
1104         if (wrote)
1105                 f2fs_submit_merged_bio(sbi, NODE, WRITE);
1106         return nwritten;
1107 }
1108
1109 int wait_on_node_pages_writeback(struct f2fs_sb_info *sbi, nid_t ino)
1110 {
1111         pgoff_t index = 0, end = LONG_MAX;
1112         struct pagevec pvec;
1113         int ret2 = 0, ret = 0;
1114
1115         pagevec_init(&pvec, 0);
1116
1117         while (index <= end) {
1118                 int i, nr_pages;
1119                 nr_pages = pagevec_lookup_tag(&pvec, NODE_MAPPING(sbi), &index,
1120                                 PAGECACHE_TAG_WRITEBACK,
1121                                 min(end - index, (pgoff_t)PAGEVEC_SIZE-1) + 1);
1122                 if (nr_pages == 0)
1123                         break;
1124
1125                 for (i = 0; i < nr_pages; i++) {
1126                         struct page *page = pvec.pages[i];
1127
1128                         /* until radix tree lookup accepts end_index */
1129                         if (unlikely(page->index > end))
1130                                 continue;
1131
1132                         if (ino && ino_of_node(page) == ino) {
1133                                 wait_on_page_writeback(page);
1134                                 if (TestClearPageError(page))
1135                                         ret = -EIO;
1136                         }
1137                 }
1138                 pagevec_release(&pvec);
1139                 cond_resched();
1140         }
1141
1142         if (unlikely(test_and_clear_bit(AS_ENOSPC, &NODE_MAPPING(sbi)->flags)))
1143                 ret2 = -ENOSPC;
1144         if (unlikely(test_and_clear_bit(AS_EIO, &NODE_MAPPING(sbi)->flags)))
1145                 ret2 = -EIO;
1146         if (!ret)
1147                 ret = ret2;
1148         return ret;
1149 }
1150
1151 static int f2fs_write_node_page(struct page *page,
1152                                 struct writeback_control *wbc)
1153 {
1154         struct f2fs_sb_info *sbi = F2FS_SB(page->mapping->host->i_sb);
1155         nid_t nid;
1156         block_t new_addr;
1157         struct node_info ni;
1158         struct f2fs_io_info fio = {
1159                 .type = NODE,
1160                 .rw = (wbc->sync_mode == WB_SYNC_ALL) ? WRITE_SYNC : WRITE,
1161         };
1162
1163         if (unlikely(sbi->por_doing))
1164                 goto redirty_out;
1165
1166         wait_on_page_writeback(page);
1167
1168         /* get old block addr of this node page */
1169         nid = nid_of_node(page);
1170         f2fs_bug_on(page->index != nid);
1171
1172         get_node_info(sbi, nid, &ni);
1173
1174         /* This page is already truncated */
1175         if (unlikely(ni.blk_addr == NULL_ADDR)) {
1176                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1177                 unlock_page(page);
1178                 return 0;
1179         }
1180
1181         if (wbc->for_reclaim)
1182                 goto redirty_out;
1183
1184         mutex_lock(&sbi->node_write);
1185         set_page_writeback(page);
1186         write_node_page(sbi, page, &fio, nid, ni.blk_addr, &new_addr);
1187         set_node_addr(sbi, &ni, new_addr);
1188         dec_page_count(sbi, F2FS_DIRTY_NODES);
1189         mutex_unlock(&sbi->node_write);
1190         unlock_page(page);
1191         return 0;
1192
1193 redirty_out:
1194         dec_page_count(sbi, F2FS_DIRTY_NODES);
1195         wbc->pages_skipped++;
1196         account_page_redirty(page);
1197         set_page_dirty(page);
1198         return AOP_WRITEPAGE_ACTIVATE;
1199 }
1200
1201 static int f2fs_write_node_pages(struct address_space *mapping,
1202                             struct writeback_control *wbc)
1203 {
1204         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1205         long nr_to_write = wbc->nr_to_write;
1206
1207         /* balancing f2fs's metadata in background */
1208         f2fs_balance_fs_bg(sbi);
1209
1210         /* collect a number of dirty node pages and write together */
1211         if (get_pages(sbi, F2FS_DIRTY_NODES) < nr_pages_to_skip(sbi, NODE))
1212                 return 0;
1213
1214         /* if mounting is failed, skip writing node pages */
1215         wbc->nr_to_write = 3 * max_hw_blocks(sbi);
1216         wbc->sync_mode = WB_SYNC_NONE;
1217         sync_node_pages(sbi, 0, wbc);
1218         wbc->nr_to_write = nr_to_write - (3 * max_hw_blocks(sbi) -
1219                                                 wbc->nr_to_write);
1220         return 0;
1221 }
1222
1223 static int f2fs_set_node_page_dirty(struct page *page)
1224 {
1225         struct address_space *mapping = page->mapping;
1226         struct f2fs_sb_info *sbi = F2FS_SB(mapping->host->i_sb);
1227
1228         trace_f2fs_set_page_dirty(page, NODE);
1229
1230         SetPageUptodate(page);
1231         if (!PageDirty(page)) {
1232                 __set_page_dirty_nobuffers(page);
1233                 inc_page_count(sbi, F2FS_DIRTY_NODES);
1234                 SetPagePrivate(page);
1235                 return 1;
1236         }
1237         return 0;
1238 }
1239
1240 static void f2fs_invalidate_node_page(struct page *page, unsigned int offset,
1241                                       unsigned int length)
1242 {
1243         struct inode *inode = page->mapping->host;
1244         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1245         if (PageDirty(page))
1246                 dec_page_count(sbi, F2FS_DIRTY_NODES);
1247         ClearPagePrivate(page);
1248 }
1249
1250 static int f2fs_release_node_page(struct page *page, gfp_t wait)
1251 {
1252         ClearPagePrivate(page);
1253         return 1;
1254 }
1255
1256 /*
1257  * Structure of the f2fs node operations
1258  */
1259 const struct address_space_operations f2fs_node_aops = {
1260         .writepage      = f2fs_write_node_page,
1261         .writepages     = f2fs_write_node_pages,
1262         .set_page_dirty = f2fs_set_node_page_dirty,
1263         .invalidatepage = f2fs_invalidate_node_page,
1264         .releasepage    = f2fs_release_node_page,
1265 };
1266
1267 static struct free_nid *__lookup_free_nid_list(struct f2fs_nm_info *nm_i,
1268                                                 nid_t n)
1269 {
1270         return radix_tree_lookup(&nm_i->free_nid_root, n);
1271 }
1272
1273 static void __del_from_free_nid_list(struct f2fs_nm_info *nm_i,
1274                                                 struct free_nid *i)
1275 {
1276         list_del(&i->list);
1277         radix_tree_delete(&nm_i->free_nid_root, i->nid);
1278         kmem_cache_free(free_nid_slab, i);
1279 }
1280
1281 static int add_free_nid(struct f2fs_nm_info *nm_i, nid_t nid, bool build)
1282 {
1283         struct free_nid *i;
1284         struct nat_entry *ne;
1285         bool allocated = false;
1286
1287         if (nm_i->fcnt > 2 * MAX_FREE_NIDS)
1288                 return -1;
1289
1290         /* 0 nid should not be used */
1291         if (unlikely(nid == 0))
1292                 return 0;
1293
1294         if (build) {
1295                 /* do not add allocated nids */
1296                 read_lock(&nm_i->nat_tree_lock);
1297                 ne = __lookup_nat_cache(nm_i, nid);
1298                 if (ne &&
1299                         (!ne->checkpointed || nat_get_blkaddr(ne) != NULL_ADDR))
1300                         allocated = true;
1301                 read_unlock(&nm_i->nat_tree_lock);
1302                 if (allocated)
1303                         return 0;
1304         }
1305
1306         i = f2fs_kmem_cache_alloc(free_nid_slab, GFP_NOFS);
1307         i->nid = nid;
1308         i->state = NID_NEW;
1309
1310         spin_lock(&nm_i->free_nid_list_lock);
1311         if (radix_tree_insert(&nm_i->free_nid_root, i->nid, i)) {
1312                 spin_unlock(&nm_i->free_nid_list_lock);
1313                 kmem_cache_free(free_nid_slab, i);
1314                 return 0;
1315         }
1316         list_add_tail(&i->list, &nm_i->free_nid_list);
1317         nm_i->fcnt++;
1318         spin_unlock(&nm_i->free_nid_list_lock);
1319         return 1;
1320 }
1321
1322 static void remove_free_nid(struct f2fs_nm_info *nm_i, nid_t nid)
1323 {
1324         struct free_nid *i;
1325         spin_lock(&nm_i->free_nid_list_lock);
1326         i = __lookup_free_nid_list(nm_i, nid);
1327         if (i && i->state == NID_NEW) {
1328                 __del_from_free_nid_list(nm_i, i);
1329                 nm_i->fcnt--;
1330         }
1331         spin_unlock(&nm_i->free_nid_list_lock);
1332 }
1333
1334 static void scan_nat_page(struct f2fs_nm_info *nm_i,
1335                         struct page *nat_page, nid_t start_nid)
1336 {
1337         struct f2fs_nat_block *nat_blk = page_address(nat_page);
1338         block_t blk_addr;
1339         int i;
1340
1341         i = start_nid % NAT_ENTRY_PER_BLOCK;
1342
1343         for (; i < NAT_ENTRY_PER_BLOCK; i++, start_nid++) {
1344
1345                 if (unlikely(start_nid >= nm_i->max_nid))
1346                         break;
1347
1348                 blk_addr = le32_to_cpu(nat_blk->entries[i].block_addr);
1349                 f2fs_bug_on(blk_addr == NEW_ADDR);
1350                 if (blk_addr == NULL_ADDR) {
1351                         if (add_free_nid(nm_i, start_nid, true) < 0)
1352                                 break;
1353                 }
1354         }
1355 }
1356
1357 static void build_free_nids(struct f2fs_sb_info *sbi)
1358 {
1359         struct f2fs_nm_info *nm_i = NM_I(sbi);
1360         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1361         struct f2fs_summary_block *sum = curseg->sum_blk;
1362         int i = 0;
1363         nid_t nid = nm_i->next_scan_nid;
1364
1365         /* Enough entries */
1366         if (nm_i->fcnt > NAT_ENTRY_PER_BLOCK)
1367                 return;
1368
1369         /* readahead nat pages to be scanned */
1370         ra_meta_pages(sbi, NAT_BLOCK_OFFSET(nid), FREE_NID_PAGES, META_NAT);
1371
1372         while (1) {
1373                 struct page *page = get_current_nat_page(sbi, nid);
1374
1375                 scan_nat_page(nm_i, page, nid);
1376                 f2fs_put_page(page, 1);
1377
1378                 nid += (NAT_ENTRY_PER_BLOCK - (nid % NAT_ENTRY_PER_BLOCK));
1379                 if (unlikely(nid >= nm_i->max_nid))
1380                         nid = 0;
1381
1382                 if (i++ == FREE_NID_PAGES)
1383                         break;
1384         }
1385
1386         /* go to the next free nat pages to find free nids abundantly */
1387         nm_i->next_scan_nid = nid;
1388
1389         /* find free nids from current sum_pages */
1390         mutex_lock(&curseg->curseg_mutex);
1391         for (i = 0; i < nats_in_cursum(sum); i++) {
1392                 block_t addr = le32_to_cpu(nat_in_journal(sum, i).block_addr);
1393                 nid = le32_to_cpu(nid_in_journal(sum, i));
1394                 if (addr == NULL_ADDR)
1395                         add_free_nid(nm_i, nid, true);
1396                 else
1397                         remove_free_nid(nm_i, nid);
1398         }
1399         mutex_unlock(&curseg->curseg_mutex);
1400 }
1401
1402 /*
1403  * If this function returns success, caller can obtain a new nid
1404  * from second parameter of this function.
1405  * The returned nid could be used ino as well as nid when inode is created.
1406  */
1407 bool alloc_nid(struct f2fs_sb_info *sbi, nid_t *nid)
1408 {
1409         struct f2fs_nm_info *nm_i = NM_I(sbi);
1410         struct free_nid *i = NULL;
1411         struct list_head *this;
1412 retry:
1413         if (unlikely(sbi->total_valid_node_count + 1 >= nm_i->max_nid))
1414                 return false;
1415
1416         spin_lock(&nm_i->free_nid_list_lock);
1417
1418         /* We should not use stale free nids created by build_free_nids */
1419         if (nm_i->fcnt && !on_build_free_nids(nm_i)) {
1420                 f2fs_bug_on(list_empty(&nm_i->free_nid_list));
1421                 list_for_each(this, &nm_i->free_nid_list) {
1422                         i = list_entry(this, struct free_nid, list);
1423                         if (i->state == NID_NEW)
1424                                 break;
1425                 }
1426
1427                 f2fs_bug_on(i->state != NID_NEW);
1428                 *nid = i->nid;
1429                 i->state = NID_ALLOC;
1430                 nm_i->fcnt--;
1431                 spin_unlock(&nm_i->free_nid_list_lock);
1432                 return true;
1433         }
1434         spin_unlock(&nm_i->free_nid_list_lock);
1435
1436         /* Let's scan nat pages and its caches to get free nids */
1437         mutex_lock(&nm_i->build_lock);
1438         build_free_nids(sbi);
1439         mutex_unlock(&nm_i->build_lock);
1440         goto retry;
1441 }
1442
1443 /*
1444  * alloc_nid() should be called prior to this function.
1445  */
1446 void alloc_nid_done(struct f2fs_sb_info *sbi, nid_t nid)
1447 {
1448         struct f2fs_nm_info *nm_i = NM_I(sbi);
1449         struct free_nid *i;
1450
1451         spin_lock(&nm_i->free_nid_list_lock);
1452         i = __lookup_free_nid_list(nm_i, nid);
1453         f2fs_bug_on(!i || i->state != NID_ALLOC);
1454         __del_from_free_nid_list(nm_i, i);
1455         spin_unlock(&nm_i->free_nid_list_lock);
1456 }
1457
1458 /*
1459  * alloc_nid() should be called prior to this function.
1460  */
1461 void alloc_nid_failed(struct f2fs_sb_info *sbi, nid_t nid)
1462 {
1463         struct f2fs_nm_info *nm_i = NM_I(sbi);
1464         struct free_nid *i;
1465
1466         if (!nid)
1467                 return;
1468
1469         spin_lock(&nm_i->free_nid_list_lock);
1470         i = __lookup_free_nid_list(nm_i, nid);
1471         f2fs_bug_on(!i || i->state != NID_ALLOC);
1472         if (nm_i->fcnt > 2 * MAX_FREE_NIDS) {
1473                 __del_from_free_nid_list(nm_i, i);
1474         } else {
1475                 i->state = NID_NEW;
1476                 nm_i->fcnt++;
1477         }
1478         spin_unlock(&nm_i->free_nid_list_lock);
1479 }
1480
1481 void recover_node_page(struct f2fs_sb_info *sbi, struct page *page,
1482                 struct f2fs_summary *sum, struct node_info *ni,
1483                 block_t new_blkaddr)
1484 {
1485         rewrite_node_page(sbi, page, sum, ni->blk_addr, new_blkaddr);
1486         set_node_addr(sbi, ni, new_blkaddr);
1487         clear_node_page_dirty(page);
1488 }
1489
1490 void recover_inline_xattr(struct inode *inode, struct page *page)
1491 {
1492         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1493         void *src_addr, *dst_addr;
1494         size_t inline_size;
1495         struct page *ipage;
1496         struct f2fs_inode *ri;
1497
1498         if (!f2fs_has_inline_xattr(inode))
1499                 return;
1500
1501         if (!IS_INODE(page))
1502                 return;
1503
1504         ri = F2FS_INODE(page);
1505         if (!(ri->i_inline & F2FS_INLINE_XATTR))
1506                 return;
1507
1508         ipage = get_node_page(sbi, inode->i_ino);
1509         f2fs_bug_on(IS_ERR(ipage));
1510
1511         dst_addr = inline_xattr_addr(ipage);
1512         src_addr = inline_xattr_addr(page);
1513         inline_size = inline_xattr_size(inode);
1514
1515         memcpy(dst_addr, src_addr, inline_size);
1516
1517         update_inode(inode, ipage);
1518         f2fs_put_page(ipage, 1);
1519 }
1520
1521 bool recover_xattr_data(struct inode *inode, struct page *page, block_t blkaddr)
1522 {
1523         struct f2fs_sb_info *sbi = F2FS_SB(inode->i_sb);
1524         nid_t prev_xnid = F2FS_I(inode)->i_xattr_nid;
1525         nid_t new_xnid = nid_of_node(page);
1526         struct node_info ni;
1527
1528         recover_inline_xattr(inode, page);
1529
1530         if (!f2fs_has_xattr_block(ofs_of_node(page)))
1531                 return false;
1532
1533         /* 1: invalidate the previous xattr nid */
1534         if (!prev_xnid)
1535                 goto recover_xnid;
1536
1537         /* Deallocate node address */
1538         get_node_info(sbi, prev_xnid, &ni);
1539         f2fs_bug_on(ni.blk_addr == NULL_ADDR);
1540         invalidate_blocks(sbi, ni.blk_addr);
1541         dec_valid_node_count(sbi, inode);
1542         set_node_addr(sbi, &ni, NULL_ADDR);
1543
1544 recover_xnid:
1545         /* 2: allocate new xattr nid */
1546         if (unlikely(!inc_valid_node_count(sbi, inode)))
1547                 f2fs_bug_on(1);
1548
1549         remove_free_nid(NM_I(sbi), new_xnid);
1550         get_node_info(sbi, new_xnid, &ni);
1551         ni.ino = inode->i_ino;
1552         set_node_addr(sbi, &ni, NEW_ADDR);
1553         F2FS_I(inode)->i_xattr_nid = new_xnid;
1554
1555         /* 3: update xattr blkaddr */
1556         refresh_sit_entry(sbi, NEW_ADDR, blkaddr);
1557         set_node_addr(sbi, &ni, blkaddr);
1558
1559         update_inode_page(inode);
1560         return true;
1561 }
1562
1563 int recover_inode_page(struct f2fs_sb_info *sbi, struct page *page)
1564 {
1565         struct f2fs_inode *src, *dst;
1566         nid_t ino = ino_of_node(page);
1567         struct node_info old_ni, new_ni;
1568         struct page *ipage;
1569
1570         ipage = grab_cache_page(NODE_MAPPING(sbi), ino);
1571         if (!ipage)
1572                 return -ENOMEM;
1573
1574         /* Should not use this inode  from free nid list */
1575         remove_free_nid(NM_I(sbi), ino);
1576
1577         get_node_info(sbi, ino, &old_ni);
1578         SetPageUptodate(ipage);
1579         fill_node_footer(ipage, ino, ino, 0, true);
1580
1581         src = F2FS_INODE(page);
1582         dst = F2FS_INODE(ipage);
1583
1584         memcpy(dst, src, (unsigned long)&src->i_ext - (unsigned long)src);
1585         dst->i_size = 0;
1586         dst->i_blocks = cpu_to_le64(1);
1587         dst->i_links = cpu_to_le32(1);
1588         dst->i_xattr_nid = 0;
1589
1590         new_ni = old_ni;
1591         new_ni.ino = ino;
1592
1593         if (unlikely(!inc_valid_node_count(sbi, NULL)))
1594                 WARN_ON(1);
1595         set_node_addr(sbi, &new_ni, NEW_ADDR);
1596         inc_valid_inode_count(sbi);
1597         f2fs_put_page(ipage, 1);
1598         return 0;
1599 }
1600
1601 /*
1602  * ra_sum_pages() merge contiguous pages into one bio and submit.
1603  * these pre-readed pages are linked in pages list.
1604  */
1605 static int ra_sum_pages(struct f2fs_sb_info *sbi, struct list_head *pages,
1606                                 int start, int nrpages)
1607 {
1608         struct page *page;
1609         int page_idx = start;
1610         struct f2fs_io_info fio = {
1611                 .type = META,
1612                 .rw = READ_SYNC | REQ_META | REQ_PRIO
1613         };
1614
1615         for (; page_idx < start + nrpages; page_idx++) {
1616                 /* alloc temporal page for read node summary info*/
1617                 page = alloc_page(GFP_F2FS_ZERO);
1618                 if (!page)
1619                         break;
1620
1621                 lock_page(page);
1622                 page->index = page_idx;
1623                 list_add_tail(&page->lru, pages);
1624         }
1625
1626         list_for_each_entry(page, pages, lru)
1627                 f2fs_submit_page_mbio(sbi, page, page->index, &fio);
1628
1629         f2fs_submit_merged_bio(sbi, META, READ);
1630
1631         return page_idx - start;
1632 }
1633
1634 int restore_node_summary(struct f2fs_sb_info *sbi,
1635                         unsigned int segno, struct f2fs_summary_block *sum)
1636 {
1637         struct f2fs_node *rn;
1638         struct f2fs_summary *sum_entry;
1639         struct page *page, *tmp;
1640         block_t addr;
1641         int bio_blocks = MAX_BIO_BLOCKS(max_hw_blocks(sbi));
1642         int i, last_offset, nrpages, err = 0;
1643         LIST_HEAD(page_list);
1644
1645         /* scan the node segment */
1646         last_offset = sbi->blocks_per_seg;
1647         addr = START_BLOCK(sbi, segno);
1648         sum_entry = &sum->entries[0];
1649
1650         for (i = 0; !err && i < last_offset; i += nrpages, addr += nrpages) {
1651                 nrpages = min(last_offset - i, bio_blocks);
1652
1653                 /* read ahead node pages */
1654                 nrpages = ra_sum_pages(sbi, &page_list, addr, nrpages);
1655                 if (!nrpages)
1656                         return -ENOMEM;
1657
1658                 list_for_each_entry_safe(page, tmp, &page_list, lru) {
1659                         if (err)
1660                                 goto skip;
1661
1662                         lock_page(page);
1663                         if (unlikely(!PageUptodate(page))) {
1664                                 err = -EIO;
1665                         } else {
1666                                 rn = F2FS_NODE(page);
1667                                 sum_entry->nid = rn->footer.nid;
1668                                 sum_entry->version = 0;
1669                                 sum_entry->ofs_in_node = 0;
1670                                 sum_entry++;
1671                         }
1672                         unlock_page(page);
1673 skip:
1674                         list_del(&page->lru);
1675                         __free_pages(page, 0);
1676                 }
1677         }
1678         return err;
1679 }
1680
1681 static bool flush_nats_in_journal(struct f2fs_sb_info *sbi)
1682 {
1683         struct f2fs_nm_info *nm_i = NM_I(sbi);
1684         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1685         struct f2fs_summary_block *sum = curseg->sum_blk;
1686         int i;
1687
1688         mutex_lock(&curseg->curseg_mutex);
1689
1690         if (nats_in_cursum(sum) < NAT_JOURNAL_ENTRIES) {
1691                 mutex_unlock(&curseg->curseg_mutex);
1692                 return false;
1693         }
1694
1695         for (i = 0; i < nats_in_cursum(sum); i++) {
1696                 struct nat_entry *ne;
1697                 struct f2fs_nat_entry raw_ne;
1698                 nid_t nid = le32_to_cpu(nid_in_journal(sum, i));
1699
1700                 raw_ne = nat_in_journal(sum, i);
1701 retry:
1702                 write_lock(&nm_i->nat_tree_lock);
1703                 ne = __lookup_nat_cache(nm_i, nid);
1704                 if (ne) {
1705                         __set_nat_cache_dirty(nm_i, ne);
1706                         write_unlock(&nm_i->nat_tree_lock);
1707                         continue;
1708                 }
1709                 ne = grab_nat_entry(nm_i, nid);
1710                 if (!ne) {
1711                         write_unlock(&nm_i->nat_tree_lock);
1712                         goto retry;
1713                 }
1714                 nat_set_blkaddr(ne, le32_to_cpu(raw_ne.block_addr));
1715                 nat_set_ino(ne, le32_to_cpu(raw_ne.ino));
1716                 nat_set_version(ne, raw_ne.version);
1717                 __set_nat_cache_dirty(nm_i, ne);
1718                 write_unlock(&nm_i->nat_tree_lock);
1719         }
1720         update_nats_in_cursum(sum, -i);
1721         mutex_unlock(&curseg->curseg_mutex);
1722         return true;
1723 }
1724
1725 /*
1726  * This function is called during the checkpointing process.
1727  */
1728 void flush_nat_entries(struct f2fs_sb_info *sbi)
1729 {
1730         struct f2fs_nm_info *nm_i = NM_I(sbi);
1731         struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_HOT_DATA);
1732         struct f2fs_summary_block *sum = curseg->sum_blk;
1733         struct list_head *cur, *n;
1734         struct page *page = NULL;
1735         struct f2fs_nat_block *nat_blk = NULL;
1736         nid_t start_nid = 0, end_nid = 0;
1737         bool flushed;
1738
1739         flushed = flush_nats_in_journal(sbi);
1740
1741         if (!flushed)
1742                 mutex_lock(&curseg->curseg_mutex);
1743
1744         /* 1) flush dirty nat caches */
1745         list_for_each_safe(cur, n, &nm_i->dirty_nat_entries) {
1746                 struct nat_entry *ne;
1747                 nid_t nid;
1748                 struct f2fs_nat_entry raw_ne;
1749                 int offset = -1;
1750                 block_t new_blkaddr;
1751
1752                 ne = list_entry(cur, struct nat_entry, list);
1753                 nid = nat_get_nid(ne);
1754
1755                 if (nat_get_blkaddr(ne) == NEW_ADDR)
1756                         continue;
1757                 if (flushed)
1758                         goto to_nat_page;
1759
1760                 /* if there is room for nat enries in curseg->sumpage */
1761                 offset = lookup_journal_in_cursum(sum, NAT_JOURNAL, nid, 1);
1762                 if (offset >= 0) {
1763                         raw_ne = nat_in_journal(sum, offset);
1764                         goto flush_now;
1765                 }
1766 to_nat_page:
1767                 if (!page || (start_nid > nid || nid > end_nid)) {
1768                         if (page) {
1769                                 f2fs_put_page(page, 1);
1770                                 page = NULL;
1771                         }
1772                         start_nid = START_NID(nid);
1773                         end_nid = start_nid + NAT_ENTRY_PER_BLOCK - 1;
1774
1775                         /*
1776                          * get nat block with dirty flag, increased reference
1777                          * count, mapped and lock
1778                          */
1779                         page = get_next_nat_page(sbi, start_nid);
1780                         nat_blk = page_address(page);
1781                 }
1782
1783                 f2fs_bug_on(!nat_blk);
1784                 raw_ne = nat_blk->entries[nid - start_nid];
1785 flush_now:
1786                 new_blkaddr = nat_get_blkaddr(ne);
1787
1788                 raw_ne.ino = cpu_to_le32(nat_get_ino(ne));
1789                 raw_ne.block_addr = cpu_to_le32(new_blkaddr);
1790                 raw_ne.version = nat_get_version(ne);
1791
1792                 if (offset < 0) {
1793                         nat_blk->entries[nid - start_nid] = raw_ne;
1794                 } else {
1795                         nat_in_journal(sum, offset) = raw_ne;
1796                         nid_in_journal(sum, offset) = cpu_to_le32(nid);
1797                 }
1798
1799                 if (nat_get_blkaddr(ne) == NULL_ADDR &&
1800                                 add_free_nid(NM_I(sbi), nid, false) <= 0) {
1801                         write_lock(&nm_i->nat_tree_lock);
1802                         __del_from_nat_cache(nm_i, ne);
1803                         write_unlock(&nm_i->nat_tree_lock);
1804                 } else {
1805                         write_lock(&nm_i->nat_tree_lock);
1806                         __clear_nat_cache_dirty(nm_i, ne);
1807                         write_unlock(&nm_i->nat_tree_lock);
1808                 }
1809         }
1810         if (!flushed)
1811                 mutex_unlock(&curseg->curseg_mutex);
1812         f2fs_put_page(page, 1);
1813
1814         /* 2) shrink nat caches if necessary */
1815         try_to_free_nats(sbi, nm_i->nat_cnt - NM_WOUT_THRESHOLD);
1816 }
1817
1818 static int init_node_manager(struct f2fs_sb_info *sbi)
1819 {
1820         struct f2fs_super_block *sb_raw = F2FS_RAW_SUPER(sbi);
1821         struct f2fs_nm_info *nm_i = NM_I(sbi);
1822         unsigned char *version_bitmap;
1823         unsigned int nat_segs, nat_blocks;
1824
1825         nm_i->nat_blkaddr = le32_to_cpu(sb_raw->nat_blkaddr);
1826
1827         /* segment_count_nat includes pair segment so divide to 2. */
1828         nat_segs = le32_to_cpu(sb_raw->segment_count_nat) >> 1;
1829         nat_blocks = nat_segs << le32_to_cpu(sb_raw->log_blocks_per_seg);
1830
1831         /* not used nids: 0, node, meta, (and root counted as valid node) */
1832         nm_i->max_nid = NAT_ENTRY_PER_BLOCK * nat_blocks - 3;
1833         nm_i->fcnt = 0;
1834         nm_i->nat_cnt = 0;
1835
1836         INIT_RADIX_TREE(&nm_i->free_nid_root, GFP_ATOMIC);
1837         INIT_LIST_HEAD(&nm_i->free_nid_list);
1838         INIT_RADIX_TREE(&nm_i->nat_root, GFP_ATOMIC);
1839         INIT_LIST_HEAD(&nm_i->nat_entries);
1840         INIT_LIST_HEAD(&nm_i->dirty_nat_entries);
1841
1842         mutex_init(&nm_i->build_lock);
1843         spin_lock_init(&nm_i->free_nid_list_lock);
1844         rwlock_init(&nm_i->nat_tree_lock);
1845
1846         nm_i->next_scan_nid = le32_to_cpu(sbi->ckpt->next_free_nid);
1847         nm_i->bitmap_size = __bitmap_size(sbi, NAT_BITMAP);
1848         version_bitmap = __bitmap_ptr(sbi, NAT_BITMAP);
1849         if (!version_bitmap)
1850                 return -EFAULT;
1851
1852         nm_i->nat_bitmap = kmemdup(version_bitmap, nm_i->bitmap_size,
1853                                         GFP_KERNEL);
1854         if (!nm_i->nat_bitmap)
1855                 return -ENOMEM;
1856         return 0;
1857 }
1858
1859 int build_node_manager(struct f2fs_sb_info *sbi)
1860 {
1861         int err;
1862
1863         sbi->nm_info = kzalloc(sizeof(struct f2fs_nm_info), GFP_KERNEL);
1864         if (!sbi->nm_info)
1865                 return -ENOMEM;
1866
1867         err = init_node_manager(sbi);
1868         if (err)
1869                 return err;
1870
1871         build_free_nids(sbi);
1872         return 0;
1873 }
1874
1875 void destroy_node_manager(struct f2fs_sb_info *sbi)
1876 {
1877         struct f2fs_nm_info *nm_i = NM_I(sbi);
1878         struct free_nid *i, *next_i;
1879         struct nat_entry *natvec[NATVEC_SIZE];
1880         nid_t nid = 0;
1881         unsigned int found;
1882
1883         if (!nm_i)
1884                 return;
1885
1886         /* destroy free nid list */
1887         spin_lock(&nm_i->free_nid_list_lock);
1888         list_for_each_entry_safe(i, next_i, &nm_i->free_nid_list, list) {
1889                 f2fs_bug_on(i->state == NID_ALLOC);
1890                 __del_from_free_nid_list(nm_i, i);
1891                 nm_i->fcnt--;
1892         }
1893         f2fs_bug_on(nm_i->fcnt);
1894         spin_unlock(&nm_i->free_nid_list_lock);
1895
1896         /* destroy nat cache */
1897         write_lock(&nm_i->nat_tree_lock);
1898         while ((found = __gang_lookup_nat_cache(nm_i,
1899                                         nid, NATVEC_SIZE, natvec))) {
1900                 unsigned idx;
1901                 nid = nat_get_nid(natvec[found - 1]) + 1;
1902                 for (idx = 0; idx < found; idx++)
1903                         __del_from_nat_cache(nm_i, natvec[idx]);
1904         }
1905         f2fs_bug_on(nm_i->nat_cnt);
1906         write_unlock(&nm_i->nat_tree_lock);
1907
1908         kfree(nm_i->nat_bitmap);
1909         sbi->nm_info = NULL;
1910         kfree(nm_i);
1911 }
1912
1913 int __init create_node_manager_caches(void)
1914 {
1915         nat_entry_slab = f2fs_kmem_cache_create("nat_entry",
1916                         sizeof(struct nat_entry));
1917         if (!nat_entry_slab)
1918                 return -ENOMEM;
1919
1920         free_nid_slab = f2fs_kmem_cache_create("free_nid",
1921                         sizeof(struct free_nid));
1922         if (!free_nid_slab) {
1923                 kmem_cache_destroy(nat_entry_slab);
1924                 return -ENOMEM;
1925         }
1926         return 0;
1927 }
1928
1929 void destroy_node_manager_caches(void)
1930 {
1931         kmem_cache_destroy(free_nid_slab);
1932         kmem_cache_destroy(nat_entry_slab);
1933 }