f2fs: leave comment for code readability
[deliverable/linux.git] / fs / f2fs / recovery.c
1 /*
2 * fs/f2fs/recovery.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 "f2fs.h"
14 #include "node.h"
15 #include "segment.h"
16
17 /*
18 * Roll forward recovery scenarios.
19 *
20 * [Term] F: fsync_mark, D: dentry_mark
21 *
22 * 1. inode(x) | CP | inode(x) | dnode(F)
23 * -> Update the latest inode(x).
24 *
25 * 2. inode(x) | CP | inode(F) | dnode(F)
26 * -> No problem.
27 *
28 * 3. inode(x) | CP | dnode(F) | inode(x)
29 * -> Recover to the latest dnode(F), and drop the last inode(x)
30 *
31 * 4. inode(x) | CP | dnode(F) | inode(F)
32 * -> No problem.
33 *
34 * 5. CP | inode(x) | dnode(F)
35 * -> The inode(DF) was missing. Should drop this dnode(F).
36 *
37 * 6. CP | inode(DF) | dnode(F)
38 * -> No problem.
39 *
40 * 7. CP | dnode(F) | inode(DF)
41 * -> If f2fs_iget fails, then goto next to find inode(DF).
42 *
43 * 8. CP | dnode(F) | inode(x)
44 * -> If f2fs_iget fails, then goto next to find inode(DF).
45 * But it will fail due to no inode(DF).
46 */
47
48 static struct kmem_cache *fsync_entry_slab;
49
50 bool space_for_roll_forward(struct f2fs_sb_info *sbi)
51 {
52 if (sbi->last_valid_block_count + sbi->alloc_valid_block_count
53 > sbi->user_block_count)
54 return false;
55 return true;
56 }
57
58 static struct fsync_inode_entry *get_fsync_inode(struct list_head *head,
59 nid_t ino)
60 {
61 struct fsync_inode_entry *entry;
62
63 list_for_each_entry(entry, head, list)
64 if (entry->inode->i_ino == ino)
65 return entry;
66
67 return NULL;
68 }
69
70 static int recover_dentry(struct inode *inode, struct page *ipage)
71 {
72 struct f2fs_inode *raw_inode = F2FS_INODE(ipage);
73 nid_t pino = le32_to_cpu(raw_inode->i_pino);
74 struct f2fs_dir_entry *de;
75 struct qstr name;
76 struct page *page;
77 struct inode *dir, *einode;
78 int err = 0;
79
80 dir = f2fs_iget(inode->i_sb, pino);
81 if (IS_ERR(dir)) {
82 err = PTR_ERR(dir);
83 goto out;
84 }
85
86 name.len = le32_to_cpu(raw_inode->i_namelen);
87 name.name = raw_inode->i_name;
88
89 if (unlikely(name.len > F2FS_NAME_LEN)) {
90 WARN_ON(1);
91 err = -ENAMETOOLONG;
92 goto out_err;
93 }
94 retry:
95 de = f2fs_find_entry(dir, &name, &page);
96 if (de && inode->i_ino == le32_to_cpu(de->ino)) {
97 clear_inode_flag(F2FS_I(inode), FI_INC_LINK);
98 goto out_unmap_put;
99 }
100 if (de) {
101 einode = f2fs_iget(inode->i_sb, le32_to_cpu(de->ino));
102 if (IS_ERR(einode)) {
103 WARN_ON(1);
104 err = PTR_ERR(einode);
105 if (err == -ENOENT)
106 err = -EEXIST;
107 goto out_unmap_put;
108 }
109 err = acquire_orphan_inode(F2FS_I_SB(inode));
110 if (err) {
111 iput(einode);
112 goto out_unmap_put;
113 }
114 f2fs_delete_entry(de, page, dir, einode);
115 iput(einode);
116 goto retry;
117 }
118 err = __f2fs_add_link(dir, &name, inode);
119 if (err)
120 goto out_err;
121
122 if (is_inode_flag_set(F2FS_I(dir), FI_DELAY_IPUT)) {
123 iput(dir);
124 } else {
125 add_dirty_dir_inode(dir);
126 set_inode_flag(F2FS_I(dir), FI_DELAY_IPUT);
127 }
128
129 goto out;
130
131 out_unmap_put:
132 f2fs_dentry_kunmap(dir, page);
133 f2fs_put_page(page, 0);
134 out_err:
135 iput(dir);
136 out:
137 f2fs_msg(inode->i_sb, KERN_NOTICE,
138 "%s: ino = %x, name = %s, dir = %lx, err = %d",
139 __func__, ino_of_node(ipage), raw_inode->i_name,
140 IS_ERR(dir) ? 0 : dir->i_ino, err);
141 return err;
142 }
143
144 static void recover_inode(struct inode *inode, struct page *page)
145 {
146 struct f2fs_inode *raw = F2FS_INODE(page);
147
148 inode->i_mode = le16_to_cpu(raw->i_mode);
149 i_size_write(inode, le64_to_cpu(raw->i_size));
150 inode->i_atime.tv_sec = le64_to_cpu(raw->i_mtime);
151 inode->i_ctime.tv_sec = le64_to_cpu(raw->i_ctime);
152 inode->i_mtime.tv_sec = le64_to_cpu(raw->i_mtime);
153 inode->i_atime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
154 inode->i_ctime.tv_nsec = le32_to_cpu(raw->i_ctime_nsec);
155 inode->i_mtime.tv_nsec = le32_to_cpu(raw->i_mtime_nsec);
156
157 f2fs_msg(inode->i_sb, KERN_NOTICE, "recover_inode: ino = %x, name = %s",
158 ino_of_node(page), F2FS_INODE(page)->i_name);
159 }
160
161 static int find_fsync_dnodes(struct f2fs_sb_info *sbi, struct list_head *head)
162 {
163 unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
164 struct curseg_info *curseg;
165 struct page *page = NULL;
166 block_t blkaddr;
167 int err = 0;
168
169 /* get node pages in the current segment */
170 curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
171 blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
172
173 ra_meta_pages(sbi, blkaddr, 1, META_POR);
174
175 while (1) {
176 struct fsync_inode_entry *entry;
177
178 if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
179 return 0;
180
181 page = get_meta_page(sbi, blkaddr);
182
183 if (cp_ver != cpver_of_node(page))
184 break;
185
186 if (!is_fsync_dnode(page))
187 goto next;
188
189 entry = get_fsync_inode(head, ino_of_node(page));
190 if (entry) {
191 if (IS_INODE(page) && is_dent_dnode(page))
192 set_inode_flag(F2FS_I(entry->inode),
193 FI_INC_LINK);
194 } else {
195 if (IS_INODE(page) && is_dent_dnode(page)) {
196 err = recover_inode_page(sbi, page);
197 if (err)
198 break;
199 }
200
201 /* add this fsync inode to the list */
202 entry = kmem_cache_alloc(fsync_entry_slab, GFP_F2FS_ZERO);
203 if (!entry) {
204 err = -ENOMEM;
205 break;
206 }
207 /*
208 * CP | dnode(F) | inode(DF)
209 * For this case, we should not give up now.
210 */
211 entry->inode = f2fs_iget(sbi->sb, ino_of_node(page));
212 if (IS_ERR(entry->inode)) {
213 err = PTR_ERR(entry->inode);
214 kmem_cache_free(fsync_entry_slab, entry);
215 if (err == -ENOENT)
216 goto next;
217 break;
218 }
219 list_add_tail(&entry->list, head);
220 }
221 entry->blkaddr = blkaddr;
222
223 if (IS_INODE(page)) {
224 entry->last_inode = blkaddr;
225 if (is_dent_dnode(page))
226 entry->last_dentry = blkaddr;
227 }
228 next:
229 /* check next segment */
230 blkaddr = next_blkaddr_of_node(page);
231 f2fs_put_page(page, 1);
232
233 ra_meta_pages_cond(sbi, blkaddr);
234 }
235 f2fs_put_page(page, 1);
236 return err;
237 }
238
239 static void destroy_fsync_dnodes(struct list_head *head)
240 {
241 struct fsync_inode_entry *entry, *tmp;
242
243 list_for_each_entry_safe(entry, tmp, head, list) {
244 iput(entry->inode);
245 list_del(&entry->list);
246 kmem_cache_free(fsync_entry_slab, entry);
247 }
248 }
249
250 static int check_index_in_prev_nodes(struct f2fs_sb_info *sbi,
251 block_t blkaddr, struct dnode_of_data *dn)
252 {
253 struct seg_entry *sentry;
254 unsigned int segno = GET_SEGNO(sbi, blkaddr);
255 unsigned short blkoff = GET_BLKOFF_FROM_SEG0(sbi, blkaddr);
256 struct f2fs_summary_block *sum_node;
257 struct f2fs_summary sum;
258 struct page *sum_page, *node_page;
259 nid_t ino, nid;
260 struct inode *inode;
261 unsigned int offset;
262 block_t bidx;
263 int i;
264
265 sentry = get_seg_entry(sbi, segno);
266 if (!f2fs_test_bit(blkoff, sentry->cur_valid_map))
267 return 0;
268
269 /* Get the previous summary */
270 for (i = CURSEG_WARM_DATA; i <= CURSEG_COLD_DATA; i++) {
271 struct curseg_info *curseg = CURSEG_I(sbi, i);
272 if (curseg->segno == segno) {
273 sum = curseg->sum_blk->entries[blkoff];
274 goto got_it;
275 }
276 }
277
278 sum_page = get_sum_page(sbi, segno);
279 sum_node = (struct f2fs_summary_block *)page_address(sum_page);
280 sum = sum_node->entries[blkoff];
281 f2fs_put_page(sum_page, 1);
282 got_it:
283 /* Use the locked dnode page and inode */
284 nid = le32_to_cpu(sum.nid);
285 if (dn->inode->i_ino == nid) {
286 struct dnode_of_data tdn = *dn;
287 tdn.nid = nid;
288 tdn.node_page = dn->inode_page;
289 tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
290 truncate_data_blocks_range(&tdn, 1);
291 return 0;
292 } else if (dn->nid == nid) {
293 struct dnode_of_data tdn = *dn;
294 tdn.ofs_in_node = le16_to_cpu(sum.ofs_in_node);
295 truncate_data_blocks_range(&tdn, 1);
296 return 0;
297 }
298
299 /* Get the node page */
300 node_page = get_node_page(sbi, nid);
301 if (IS_ERR(node_page))
302 return PTR_ERR(node_page);
303
304 offset = ofs_of_node(node_page);
305 ino = ino_of_node(node_page);
306 f2fs_put_page(node_page, 1);
307
308 if (ino != dn->inode->i_ino) {
309 /* Deallocate previous index in the node page */
310 inode = f2fs_iget(sbi->sb, ino);
311 if (IS_ERR(inode))
312 return PTR_ERR(inode);
313 } else {
314 inode = dn->inode;
315 }
316
317 bidx = start_bidx_of_node(offset, F2FS_I(inode)) +
318 le16_to_cpu(sum.ofs_in_node);
319
320 if (ino != dn->inode->i_ino) {
321 truncate_hole(inode, bidx, bidx + 1);
322 iput(inode);
323 } else {
324 struct dnode_of_data tdn;
325 set_new_dnode(&tdn, inode, dn->inode_page, NULL, 0);
326 if (get_dnode_of_data(&tdn, bidx, LOOKUP_NODE))
327 return 0;
328 if (tdn.data_blkaddr != NULL_ADDR)
329 truncate_data_blocks_range(&tdn, 1);
330 f2fs_put_page(tdn.node_page, 1);
331 }
332 return 0;
333 }
334
335 static int do_recover_data(struct f2fs_sb_info *sbi, struct inode *inode,
336 struct page *page, block_t blkaddr)
337 {
338 struct f2fs_inode_info *fi = F2FS_I(inode);
339 unsigned int start, end;
340 struct dnode_of_data dn;
341 struct f2fs_summary sum;
342 struct node_info ni;
343 int err = 0, recovered = 0;
344
345 /* step 1: recover xattr */
346 if (IS_INODE(page)) {
347 recover_inline_xattr(inode, page);
348 } else if (f2fs_has_xattr_block(ofs_of_node(page))) {
349 /*
350 * Deprecated; xattr blocks should be found from cold log.
351 * But, we should remain this for backward compatibility.
352 */
353 recover_xattr_data(inode, page, blkaddr);
354 goto out;
355 }
356
357 /* step 2: recover inline data */
358 if (recover_inline_data(inode, page))
359 goto out;
360
361 /* step 3: recover data indices */
362 start = start_bidx_of_node(ofs_of_node(page), fi);
363 end = start + ADDRS_PER_PAGE(page, fi);
364
365 f2fs_lock_op(sbi);
366
367 set_new_dnode(&dn, inode, NULL, NULL, 0);
368
369 err = get_dnode_of_data(&dn, start, ALLOC_NODE);
370 if (err) {
371 f2fs_unlock_op(sbi);
372 goto out;
373 }
374
375 f2fs_wait_on_page_writeback(dn.node_page, NODE);
376
377 get_node_info(sbi, dn.nid, &ni);
378 f2fs_bug_on(sbi, ni.ino != ino_of_node(page));
379 f2fs_bug_on(sbi, ofs_of_node(dn.node_page) != ofs_of_node(page));
380
381 for (; start < end; start++) {
382 block_t src, dest;
383
384 src = datablock_addr(dn.node_page, dn.ofs_in_node);
385 dest = datablock_addr(page, dn.ofs_in_node);
386
387 if (src != dest && dest != NEW_ADDR && dest != NULL_ADDR) {
388 if (src == NULL_ADDR) {
389 err = reserve_new_block(&dn);
390 /* We should not get -ENOSPC */
391 f2fs_bug_on(sbi, err);
392 }
393
394 /* Check the previous node page having this index */
395 err = check_index_in_prev_nodes(sbi, dest, &dn);
396 if (err)
397 goto err;
398
399 set_summary(&sum, dn.nid, dn.ofs_in_node, ni.version);
400
401 /* write dummy data page */
402 recover_data_page(sbi, NULL, &sum, src, dest);
403 dn.data_blkaddr = dest;
404 update_extent_cache(&dn);
405 recovered++;
406 }
407 dn.ofs_in_node++;
408 }
409
410 /* write node page in place */
411 set_summary(&sum, dn.nid, 0, 0);
412 if (IS_INODE(dn.node_page))
413 sync_inode_page(&dn);
414
415 copy_node_footer(dn.node_page, page);
416 fill_node_footer(dn.node_page, dn.nid, ni.ino,
417 ofs_of_node(page), false);
418 set_page_dirty(dn.node_page);
419 err:
420 f2fs_put_dnode(&dn);
421 f2fs_unlock_op(sbi);
422 out:
423 f2fs_msg(sbi->sb, KERN_NOTICE,
424 "recover_data: ino = %lx, recovered = %d blocks, err = %d",
425 inode->i_ino, recovered, err);
426 return err;
427 }
428
429 static int recover_data(struct f2fs_sb_info *sbi,
430 struct list_head *head, int type)
431 {
432 unsigned long long cp_ver = cur_cp_version(F2FS_CKPT(sbi));
433 struct curseg_info *curseg;
434 struct page *page = NULL;
435 int err = 0;
436 block_t blkaddr;
437
438 /* get node pages in the current segment */
439 curseg = CURSEG_I(sbi, type);
440 blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
441
442 while (1) {
443 struct fsync_inode_entry *entry;
444
445 if (blkaddr < MAIN_BLKADDR(sbi) || blkaddr >= MAX_BLKADDR(sbi))
446 break;
447
448 ra_meta_pages_cond(sbi, blkaddr);
449
450 page = get_meta_page(sbi, blkaddr);
451
452 if (cp_ver != cpver_of_node(page)) {
453 f2fs_put_page(page, 1);
454 break;
455 }
456
457 entry = get_fsync_inode(head, ino_of_node(page));
458 if (!entry)
459 goto next;
460 /*
461 * inode(x) | CP | inode(x) | dnode(F)
462 * In this case, we can lose the latest inode(x).
463 * So, call recover_inode for the inode update.
464 */
465 if (entry->last_inode == blkaddr)
466 recover_inode(entry->inode, page);
467 if (entry->last_dentry == blkaddr) {
468 err = recover_dentry(entry->inode, page);
469 if (err) {
470 f2fs_put_page(page, 1);
471 break;
472 }
473 }
474 err = do_recover_data(sbi, entry->inode, page, blkaddr);
475 if (err) {
476 f2fs_put_page(page, 1);
477 break;
478 }
479
480 if (entry->blkaddr == blkaddr) {
481 iput(entry->inode);
482 list_del(&entry->list);
483 kmem_cache_free(fsync_entry_slab, entry);
484 }
485 next:
486 /* check next segment */
487 blkaddr = next_blkaddr_of_node(page);
488 f2fs_put_page(page, 1);
489 }
490 if (!err)
491 allocate_new_segments(sbi);
492 return err;
493 }
494
495 int recover_fsync_data(struct f2fs_sb_info *sbi)
496 {
497 struct curseg_info *curseg = CURSEG_I(sbi, CURSEG_WARM_NODE);
498 struct list_head inode_list;
499 block_t blkaddr;
500 int err;
501 bool need_writecp = false;
502
503 fsync_entry_slab = f2fs_kmem_cache_create("f2fs_fsync_inode_entry",
504 sizeof(struct fsync_inode_entry));
505 if (!fsync_entry_slab)
506 return -ENOMEM;
507
508 INIT_LIST_HEAD(&inode_list);
509
510 /* step #1: find fsynced inode numbers */
511 sbi->por_doing = true;
512
513 /* prevent checkpoint */
514 mutex_lock(&sbi->cp_mutex);
515
516 blkaddr = NEXT_FREE_BLKADDR(sbi, curseg);
517
518 err = find_fsync_dnodes(sbi, &inode_list);
519 if (err)
520 goto out;
521
522 if (list_empty(&inode_list))
523 goto out;
524
525 need_writecp = true;
526
527 /* step #2: recover data */
528 err = recover_data(sbi, &inode_list, CURSEG_WARM_NODE);
529 if (!err)
530 f2fs_bug_on(sbi, !list_empty(&inode_list));
531 out:
532 destroy_fsync_dnodes(&inode_list);
533 kmem_cache_destroy(fsync_entry_slab);
534
535 /* truncate meta pages to be used by the recovery */
536 truncate_inode_pages_range(META_MAPPING(sbi),
537 MAIN_BLKADDR(sbi) << PAGE_CACHE_SHIFT, -1);
538
539 if (err) {
540 truncate_inode_pages_final(NODE_MAPPING(sbi));
541 truncate_inode_pages_final(META_MAPPING(sbi));
542 }
543
544 sbi->por_doing = false;
545 if (err) {
546 discard_next_dnode(sbi, blkaddr);
547
548 /* Flush all the NAT/SIT pages */
549 while (get_pages(sbi, F2FS_DIRTY_META))
550 sync_meta_pages(sbi, META, LONG_MAX);
551 set_ckpt_flags(sbi->ckpt, CP_ERROR_FLAG);
552 mutex_unlock(&sbi->cp_mutex);
553 } else if (need_writecp) {
554 struct cp_control cpc = {
555 .reason = CP_SYNC,
556 };
557 mutex_unlock(&sbi->cp_mutex);
558 write_checkpoint(sbi, &cpc);
559 } else {
560 mutex_unlock(&sbi->cp_mutex);
561 }
562 return err;
563 }
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