1 // SPDX-License-Identifier: GPL-2.0+
2 /*
3  * Meta data file for NILFS
4  *
5  * Copyright (C) 2005-2008 Nippon Telegraph and Telephone Corporation.
6  *
7  * Written by Ryusuke Konishi.
8  */
9 
10 #include <linux/buffer_head.h>
11 #include <linux/mpage.h>
12 #include <linux/mm.h>
13 #include <linux/writeback.h>
14 #include <linux/backing-dev.h>
15 #include <linux/swap.h>
16 #include <linux/slab.h>
17 #include "nilfs.h"
18 #include "btnode.h"
19 #include "segment.h"
20 #include "page.h"
21 #include "mdt.h"
22 #include "alloc.h"		/* nilfs_palloc_destroy_cache() */
23 
24 #include <trace/events/nilfs2.h>
25 
26 #define NILFS_MDT_MAX_RA_BLOCKS		(16 - 1)
27 
28 
29 static int
nilfs_mdt_insert_new_block(struct inode * inode,unsigned long block,struct buffer_head * bh,void (* init_block)(struct inode *,struct buffer_head *,void *))30 nilfs_mdt_insert_new_block(struct inode *inode, unsigned long block,
31 			   struct buffer_head *bh,
32 			   void (*init_block)(struct inode *,
33 					      struct buffer_head *, void *))
34 {
35 	struct nilfs_inode_info *ii = NILFS_I(inode);
36 	void *kaddr;
37 	int ret;
38 
39 	/* Caller exclude read accesses using page lock */
40 
41 	/* set_buffer_new(bh); */
42 	bh->b_blocknr = 0;
43 
44 	ret = nilfs_bmap_insert(ii->i_bmap, block, (unsigned long)bh);
45 	if (unlikely(ret))
46 		return ret;
47 
48 	set_buffer_mapped(bh);
49 
50 	kaddr = kmap_local_page(bh->b_page);
51 	memset(kaddr + bh_offset(bh), 0, i_blocksize(inode));
52 	if (init_block)
53 		init_block(inode, bh, kaddr);
54 	flush_dcache_page(bh->b_page);
55 	kunmap_local(kaddr);
56 
57 	set_buffer_uptodate(bh);
58 	mark_buffer_dirty(bh);
59 	nilfs_mdt_mark_dirty(inode);
60 
61 	trace_nilfs2_mdt_insert_new_block(inode, inode->i_ino, block);
62 
63 	return 0;
64 }
65 
nilfs_mdt_create_block(struct inode * inode,unsigned long block,struct buffer_head ** out_bh,void (* init_block)(struct inode *,struct buffer_head *,void *))66 static int nilfs_mdt_create_block(struct inode *inode, unsigned long block,
67 				  struct buffer_head **out_bh,
68 				  void (*init_block)(struct inode *,
69 						     struct buffer_head *,
70 						     void *))
71 {
72 	struct super_block *sb = inode->i_sb;
73 	struct nilfs_transaction_info ti;
74 	struct buffer_head *bh;
75 	int err;
76 
77 	nilfs_transaction_begin(sb, &ti, 0);
78 
79 	err = -ENOMEM;
80 	bh = nilfs_grab_buffer(inode, inode->i_mapping, block, 0);
81 	if (unlikely(!bh))
82 		goto failed_unlock;
83 
84 	err = -EEXIST;
85 	if (buffer_uptodate(bh))
86 		goto failed_bh;
87 
88 	wait_on_buffer(bh);
89 	if (buffer_uptodate(bh))
90 		goto failed_bh;
91 
92 	err = nilfs_mdt_insert_new_block(inode, block, bh, init_block);
93 	if (likely(!err)) {
94 		get_bh(bh);
95 		*out_bh = bh;
96 	}
97 
98  failed_bh:
99 	folio_unlock(bh->b_folio);
100 	folio_put(bh->b_folio);
101 	brelse(bh);
102 
103  failed_unlock:
104 	if (likely(!err))
105 		err = nilfs_transaction_commit(sb);
106 	else
107 		nilfs_transaction_abort(sb);
108 
109 	return err;
110 }
111 
112 static int
nilfs_mdt_submit_block(struct inode * inode,unsigned long blkoff,blk_opf_t opf,struct buffer_head ** out_bh)113 nilfs_mdt_submit_block(struct inode *inode, unsigned long blkoff, blk_opf_t opf,
114 		       struct buffer_head **out_bh)
115 {
116 	struct buffer_head *bh;
117 	__u64 blknum = 0;
118 	int ret = -ENOMEM;
119 
120 	bh = nilfs_grab_buffer(inode, inode->i_mapping, blkoff, 0);
121 	if (unlikely(!bh))
122 		goto failed;
123 
124 	ret = -EEXIST; /* internal code */
125 	if (buffer_uptodate(bh))
126 		goto out;
127 
128 	if (opf & REQ_RAHEAD) {
129 		if (!trylock_buffer(bh)) {
130 			ret = -EBUSY;
131 			goto failed_bh;
132 		}
133 	} else /* opf == REQ_OP_READ */
134 		lock_buffer(bh);
135 
136 	if (buffer_uptodate(bh)) {
137 		unlock_buffer(bh);
138 		goto out;
139 	}
140 
141 	ret = nilfs_bmap_lookup(NILFS_I(inode)->i_bmap, blkoff, &blknum);
142 	if (unlikely(ret)) {
143 		unlock_buffer(bh);
144 		goto failed_bh;
145 	}
146 	map_bh(bh, inode->i_sb, (sector_t)blknum);
147 
148 	bh->b_end_io = end_buffer_read_sync;
149 	get_bh(bh);
150 	submit_bh(opf, bh);
151 	ret = 0;
152 
153 	trace_nilfs2_mdt_submit_block(inode, inode->i_ino, blkoff,
154 				      opf & REQ_OP_MASK);
155  out:
156 	get_bh(bh);
157 	*out_bh = bh;
158 
159  failed_bh:
160 	folio_unlock(bh->b_folio);
161 	folio_put(bh->b_folio);
162 	brelse(bh);
163  failed:
164 	return ret;
165 }
166 
nilfs_mdt_read_block(struct inode * inode,unsigned long block,int readahead,struct buffer_head ** out_bh)167 static int nilfs_mdt_read_block(struct inode *inode, unsigned long block,
168 				int readahead, struct buffer_head **out_bh)
169 {
170 	struct buffer_head *first_bh, *bh;
171 	unsigned long blkoff;
172 	int i, nr_ra_blocks = NILFS_MDT_MAX_RA_BLOCKS;
173 	int err;
174 
175 	err = nilfs_mdt_submit_block(inode, block, REQ_OP_READ, &first_bh);
176 	if (err == -EEXIST) /* internal code */
177 		goto out;
178 
179 	if (unlikely(err))
180 		goto failed;
181 
182 	if (readahead) {
183 		blkoff = block + 1;
184 		for (i = 0; i < nr_ra_blocks; i++, blkoff++) {
185 			err = nilfs_mdt_submit_block(inode, blkoff,
186 						REQ_OP_READ | REQ_RAHEAD, &bh);
187 			if (likely(!err || err == -EEXIST))
188 				brelse(bh);
189 			else if (err != -EBUSY)
190 				break;
191 				/* abort readahead if bmap lookup failed */
192 			if (!buffer_locked(first_bh))
193 				goto out_no_wait;
194 		}
195 	}
196 
197 	wait_on_buffer(first_bh);
198 
199  out_no_wait:
200 	err = -EIO;
201 	if (!buffer_uptodate(first_bh)) {
202 		nilfs_err(inode->i_sb,
203 			  "I/O error reading meta-data file (ino=%lu, block-offset=%lu)",
204 			  inode->i_ino, block);
205 		goto failed_bh;
206 	}
207  out:
208 	*out_bh = first_bh;
209 	return 0;
210 
211  failed_bh:
212 	brelse(first_bh);
213  failed:
214 	return err;
215 }
216 
217 /**
218  * nilfs_mdt_get_block - read or create a buffer on meta data file.
219  * @inode: inode of the meta data file
220  * @blkoff: block offset
221  * @create: create flag
222  * @init_block: initializer used for newly allocated block
223  * @out_bh: output of a pointer to the buffer_head
224  *
225  * nilfs_mdt_get_block() looks up the specified buffer and tries to create
226  * a new buffer if @create is not zero.  On success, the returned buffer is
227  * assured to be either existing or formatted using a buffer lock on success.
228  * @out_bh is substituted only when zero is returned.
229  *
230  * Return Value: On success, it returns 0. On error, the following negative
231  * error code is returned.
232  *
233  * %-ENOMEM - Insufficient memory available.
234  *
235  * %-EIO - I/O error
236  *
237  * %-ENOENT - the specified block does not exist (hole block)
238  *
239  * %-EROFS - Read only filesystem (for create mode)
240  */
nilfs_mdt_get_block(struct inode * inode,unsigned long blkoff,int create,void (* init_block)(struct inode *,struct buffer_head *,void *),struct buffer_head ** out_bh)241 int nilfs_mdt_get_block(struct inode *inode, unsigned long blkoff, int create,
242 			void (*init_block)(struct inode *,
243 					   struct buffer_head *, void *),
244 			struct buffer_head **out_bh)
245 {
246 	int ret;
247 
248 	/* Should be rewritten with merging nilfs_mdt_read_block() */
249  retry:
250 	ret = nilfs_mdt_read_block(inode, blkoff, !create, out_bh);
251 	if (!create || ret != -ENOENT)
252 		return ret;
253 
254 	ret = nilfs_mdt_create_block(inode, blkoff, out_bh, init_block);
255 	if (unlikely(ret == -EEXIST)) {
256 		/* create = 0; */  /* limit read-create loop retries */
257 		goto retry;
258 	}
259 	return ret;
260 }
261 
262 /**
263  * nilfs_mdt_find_block - find and get a buffer on meta data file.
264  * @inode: inode of the meta data file
265  * @start: start block offset (inclusive)
266  * @end: end block offset (inclusive)
267  * @blkoff: block offset
268  * @out_bh: place to store a pointer to buffer_head struct
269  *
270  * nilfs_mdt_find_block() looks up an existing block in range of
271  * [@start, @end] and stores pointer to a buffer head of the block to
272  * @out_bh, and block offset to @blkoff, respectively.  @out_bh and
273  * @blkoff are substituted only when zero is returned.
274  *
275  * Return Value: On success, it returns 0. On error, the following negative
276  * error code is returned.
277  *
278  * %-ENOMEM - Insufficient memory available.
279  *
280  * %-EIO - I/O error
281  *
282  * %-ENOENT - no block was found in the range
283  */
nilfs_mdt_find_block(struct inode * inode,unsigned long start,unsigned long end,unsigned long * blkoff,struct buffer_head ** out_bh)284 int nilfs_mdt_find_block(struct inode *inode, unsigned long start,
285 			 unsigned long end, unsigned long *blkoff,
286 			 struct buffer_head **out_bh)
287 {
288 	__u64 next;
289 	int ret;
290 
291 	if (unlikely(start > end))
292 		return -ENOENT;
293 
294 	ret = nilfs_mdt_read_block(inode, start, true, out_bh);
295 	if (!ret) {
296 		*blkoff = start;
297 		goto out;
298 	}
299 	if (unlikely(ret != -ENOENT || start == ULONG_MAX))
300 		goto out;
301 
302 	ret = nilfs_bmap_seek_key(NILFS_I(inode)->i_bmap, start + 1, &next);
303 	if (!ret) {
304 		if (next <= end) {
305 			ret = nilfs_mdt_read_block(inode, next, true, out_bh);
306 			if (!ret)
307 				*blkoff = next;
308 		} else {
309 			ret = -ENOENT;
310 		}
311 	}
312 out:
313 	return ret;
314 }
315 
316 /**
317  * nilfs_mdt_delete_block - make a hole on the meta data file.
318  * @inode: inode of the meta data file
319  * @block: block offset
320  *
321  * Return Value: On success, zero is returned.
322  * On error, one of the following negative error code is returned.
323  *
324  * %-ENOMEM - Insufficient memory available.
325  *
326  * %-EIO - I/O error
327  */
nilfs_mdt_delete_block(struct inode * inode,unsigned long block)328 int nilfs_mdt_delete_block(struct inode *inode, unsigned long block)
329 {
330 	struct nilfs_inode_info *ii = NILFS_I(inode);
331 	int err;
332 
333 	err = nilfs_bmap_delete(ii->i_bmap, block);
334 	if (!err || err == -ENOENT) {
335 		nilfs_mdt_mark_dirty(inode);
336 		nilfs_mdt_forget_block(inode, block);
337 	}
338 	return err;
339 }
340 
341 /**
342  * nilfs_mdt_forget_block - discard dirty state and try to remove the page
343  * @inode: inode of the meta data file
344  * @block: block offset
345  *
346  * nilfs_mdt_forget_block() clears a dirty flag of the specified buffer, and
347  * tries to release the page including the buffer from a page cache.
348  *
349  * Return Value: On success, 0 is returned. On error, one of the following
350  * negative error code is returned.
351  *
352  * %-EBUSY - page has an active buffer.
353  *
354  * %-ENOENT - page cache has no page addressed by the offset.
355  */
nilfs_mdt_forget_block(struct inode * inode,unsigned long block)356 int nilfs_mdt_forget_block(struct inode *inode, unsigned long block)
357 {
358 	pgoff_t index = block >> (PAGE_SHIFT - inode->i_blkbits);
359 	struct folio *folio;
360 	struct buffer_head *bh;
361 	int ret = 0;
362 	int still_dirty;
363 
364 	folio = filemap_lock_folio(inode->i_mapping, index);
365 	if (IS_ERR(folio))
366 		return -ENOENT;
367 
368 	folio_wait_writeback(folio);
369 
370 	bh = folio_buffers(folio);
371 	if (bh) {
372 		unsigned long first_block = index <<
373 				(PAGE_SHIFT - inode->i_blkbits);
374 		bh = get_nth_bh(bh, block - first_block);
375 		nilfs_forget_buffer(bh);
376 	}
377 	still_dirty = folio_test_dirty(folio);
378 	folio_unlock(folio);
379 	folio_put(folio);
380 
381 	if (still_dirty ||
382 	    invalidate_inode_pages2_range(inode->i_mapping, index, index) != 0)
383 		ret = -EBUSY;
384 	return ret;
385 }
386 
nilfs_mdt_fetch_dirty(struct inode * inode)387 int nilfs_mdt_fetch_dirty(struct inode *inode)
388 {
389 	struct nilfs_inode_info *ii = NILFS_I(inode);
390 
391 	if (nilfs_bmap_test_and_clear_dirty(ii->i_bmap)) {
392 		set_bit(NILFS_I_DIRTY, &ii->i_state);
393 		return 1;
394 	}
395 	return test_bit(NILFS_I_DIRTY, &ii->i_state);
396 }
397 
398 static int
nilfs_mdt_write_page(struct page * page,struct writeback_control * wbc)399 nilfs_mdt_write_page(struct page *page, struct writeback_control *wbc)
400 {
401 	struct folio *folio = page_folio(page);
402 	struct inode *inode = folio->mapping->host;
403 	struct super_block *sb;
404 	int err = 0;
405 
406 	if (inode && sb_rdonly(inode->i_sb)) {
407 		/*
408 		 * It means that filesystem was remounted in read-only
409 		 * mode because of error or metadata corruption. But we
410 		 * have dirty folios that try to be flushed in background.
411 		 * So, here we simply discard this dirty folio.
412 		 */
413 		nilfs_clear_folio_dirty(folio);
414 		folio_unlock(folio);
415 		return -EROFS;
416 	}
417 
418 	folio_redirty_for_writepage(wbc, folio);
419 	folio_unlock(folio);
420 
421 	if (!inode)
422 		return 0;
423 
424 	sb = inode->i_sb;
425 
426 	if (wbc->sync_mode == WB_SYNC_ALL)
427 		err = nilfs_construct_segment(sb);
428 	else if (wbc->for_reclaim)
429 		nilfs_flush_segment(sb, inode->i_ino);
430 
431 	return err;
432 }
433 
434 
435 static const struct address_space_operations def_mdt_aops = {
436 	.dirty_folio		= block_dirty_folio,
437 	.invalidate_folio	= block_invalidate_folio,
438 	.writepage		= nilfs_mdt_write_page,
439 };
440 
441 static const struct inode_operations def_mdt_iops;
442 static const struct file_operations def_mdt_fops;
443 
444 
nilfs_mdt_init(struct inode * inode,gfp_t gfp_mask,size_t objsz)445 int nilfs_mdt_init(struct inode *inode, gfp_t gfp_mask, size_t objsz)
446 {
447 	struct nilfs_mdt_info *mi;
448 
449 	mi = kzalloc(max(sizeof(*mi), objsz), GFP_NOFS);
450 	if (!mi)
451 		return -ENOMEM;
452 
453 	init_rwsem(&mi->mi_sem);
454 	inode->i_private = mi;
455 
456 	inode->i_mode = S_IFREG;
457 	mapping_set_gfp_mask(inode->i_mapping, gfp_mask);
458 
459 	inode->i_op = &def_mdt_iops;
460 	inode->i_fop = &def_mdt_fops;
461 	inode->i_mapping->a_ops = &def_mdt_aops;
462 
463 	return 0;
464 }
465 
466 /**
467  * nilfs_mdt_clear - do cleanup for the metadata file
468  * @inode: inode of the metadata file
469  */
nilfs_mdt_clear(struct inode * inode)470 void nilfs_mdt_clear(struct inode *inode)
471 {
472 	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
473 	struct nilfs_shadow_map *shadow = mdi->mi_shadow;
474 
475 	if (mdi->mi_palloc_cache)
476 		nilfs_palloc_destroy_cache(inode);
477 
478 	if (shadow) {
479 		struct inode *s_inode = shadow->inode;
480 
481 		shadow->inode = NULL;
482 		iput(s_inode);
483 		mdi->mi_shadow = NULL;
484 	}
485 }
486 
487 /**
488  * nilfs_mdt_destroy - release resources used by the metadata file
489  * @inode: inode of the metadata file
490  */
nilfs_mdt_destroy(struct inode * inode)491 void nilfs_mdt_destroy(struct inode *inode)
492 {
493 	struct nilfs_mdt_info *mdi = NILFS_MDT(inode);
494 
495 	kfree(mdi->mi_bgl); /* kfree(NULL) is safe */
496 	kfree(mdi);
497 }
498 
nilfs_mdt_set_entry_size(struct inode * inode,unsigned int entry_size,unsigned int header_size)499 void nilfs_mdt_set_entry_size(struct inode *inode, unsigned int entry_size,
500 			      unsigned int header_size)
501 {
502 	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
503 
504 	mi->mi_entry_size = entry_size;
505 	mi->mi_entries_per_block = i_blocksize(inode) / entry_size;
506 	mi->mi_first_entry_offset = DIV_ROUND_UP(header_size, entry_size);
507 }
508 
509 /**
510  * nilfs_mdt_setup_shadow_map - setup shadow map and bind it to metadata file
511  * @inode: inode of the metadata file
512  * @shadow: shadow mapping
513  */
nilfs_mdt_setup_shadow_map(struct inode * inode,struct nilfs_shadow_map * shadow)514 int nilfs_mdt_setup_shadow_map(struct inode *inode,
515 			       struct nilfs_shadow_map *shadow)
516 {
517 	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
518 	struct inode *s_inode;
519 
520 	INIT_LIST_HEAD(&shadow->frozen_buffers);
521 
522 	s_inode = nilfs_iget_for_shadow(inode);
523 	if (IS_ERR(s_inode))
524 		return PTR_ERR(s_inode);
525 
526 	shadow->inode = s_inode;
527 	mi->mi_shadow = shadow;
528 	return 0;
529 }
530 
531 /**
532  * nilfs_mdt_save_to_shadow_map - copy bmap and dirty pages to shadow map
533  * @inode: inode of the metadata file
534  */
nilfs_mdt_save_to_shadow_map(struct inode * inode)535 int nilfs_mdt_save_to_shadow_map(struct inode *inode)
536 {
537 	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
538 	struct nilfs_inode_info *ii = NILFS_I(inode);
539 	struct nilfs_shadow_map *shadow = mi->mi_shadow;
540 	struct inode *s_inode = shadow->inode;
541 	int ret;
542 
543 	ret = nilfs_copy_dirty_pages(s_inode->i_mapping, inode->i_mapping);
544 	if (ret)
545 		goto out;
546 
547 	ret = nilfs_copy_dirty_pages(NILFS_I(s_inode)->i_assoc_inode->i_mapping,
548 				     ii->i_assoc_inode->i_mapping);
549 	if (ret)
550 		goto out;
551 
552 	nilfs_bmap_save(ii->i_bmap, &shadow->bmap_store);
553  out:
554 	return ret;
555 }
556 
nilfs_mdt_freeze_buffer(struct inode * inode,struct buffer_head * bh)557 int nilfs_mdt_freeze_buffer(struct inode *inode, struct buffer_head *bh)
558 {
559 	struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
560 	struct buffer_head *bh_frozen;
561 	struct folio *folio;
562 	int blkbits = inode->i_blkbits;
563 
564 	folio = filemap_grab_folio(shadow->inode->i_mapping,
565 			bh->b_folio->index);
566 	if (IS_ERR(folio))
567 		return PTR_ERR(folio);
568 
569 	bh_frozen = folio_buffers(folio);
570 	if (!bh_frozen)
571 		bh_frozen = create_empty_buffers(folio, 1 << blkbits, 0);
572 
573 	bh_frozen = get_nth_bh(bh_frozen, bh_offset(bh) >> blkbits);
574 
575 	if (!buffer_uptodate(bh_frozen))
576 		nilfs_copy_buffer(bh_frozen, bh);
577 	if (list_empty(&bh_frozen->b_assoc_buffers)) {
578 		list_add_tail(&bh_frozen->b_assoc_buffers,
579 			      &shadow->frozen_buffers);
580 		set_buffer_nilfs_redirected(bh);
581 	} else {
582 		brelse(bh_frozen); /* already frozen */
583 	}
584 
585 	folio_unlock(folio);
586 	folio_put(folio);
587 	return 0;
588 }
589 
590 struct buffer_head *
nilfs_mdt_get_frozen_buffer(struct inode * inode,struct buffer_head * bh)591 nilfs_mdt_get_frozen_buffer(struct inode *inode, struct buffer_head *bh)
592 {
593 	struct nilfs_shadow_map *shadow = NILFS_MDT(inode)->mi_shadow;
594 	struct buffer_head *bh_frozen = NULL;
595 	struct folio *folio;
596 	int n;
597 
598 	folio = filemap_lock_folio(shadow->inode->i_mapping,
599 			bh->b_folio->index);
600 	if (!IS_ERR(folio)) {
601 		bh_frozen = folio_buffers(folio);
602 		if (bh_frozen) {
603 			n = bh_offset(bh) >> inode->i_blkbits;
604 			bh_frozen = get_nth_bh(bh_frozen, n);
605 		}
606 		folio_unlock(folio);
607 		folio_put(folio);
608 	}
609 	return bh_frozen;
610 }
611 
nilfs_release_frozen_buffers(struct nilfs_shadow_map * shadow)612 static void nilfs_release_frozen_buffers(struct nilfs_shadow_map *shadow)
613 {
614 	struct list_head *head = &shadow->frozen_buffers;
615 	struct buffer_head *bh;
616 
617 	while (!list_empty(head)) {
618 		bh = list_first_entry(head, struct buffer_head,
619 				      b_assoc_buffers);
620 		list_del_init(&bh->b_assoc_buffers);
621 		brelse(bh); /* drop ref-count to make it releasable */
622 	}
623 }
624 
625 /**
626  * nilfs_mdt_restore_from_shadow_map - restore dirty pages and bmap state
627  * @inode: inode of the metadata file
628  */
nilfs_mdt_restore_from_shadow_map(struct inode * inode)629 void nilfs_mdt_restore_from_shadow_map(struct inode *inode)
630 {
631 	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
632 	struct nilfs_inode_info *ii = NILFS_I(inode);
633 	struct nilfs_shadow_map *shadow = mi->mi_shadow;
634 
635 	down_write(&mi->mi_sem);
636 
637 	if (mi->mi_palloc_cache)
638 		nilfs_palloc_clear_cache(inode);
639 
640 	nilfs_clear_dirty_pages(inode->i_mapping);
641 	nilfs_copy_back_pages(inode->i_mapping, shadow->inode->i_mapping);
642 
643 	nilfs_clear_dirty_pages(ii->i_assoc_inode->i_mapping);
644 	nilfs_copy_back_pages(ii->i_assoc_inode->i_mapping,
645 			      NILFS_I(shadow->inode)->i_assoc_inode->i_mapping);
646 
647 	nilfs_bmap_restore(ii->i_bmap, &shadow->bmap_store);
648 
649 	up_write(&mi->mi_sem);
650 }
651 
652 /**
653  * nilfs_mdt_clear_shadow_map - truncate pages in shadow map caches
654  * @inode: inode of the metadata file
655  */
nilfs_mdt_clear_shadow_map(struct inode * inode)656 void nilfs_mdt_clear_shadow_map(struct inode *inode)
657 {
658 	struct nilfs_mdt_info *mi = NILFS_MDT(inode);
659 	struct nilfs_shadow_map *shadow = mi->mi_shadow;
660 	struct inode *shadow_btnc_inode = NILFS_I(shadow->inode)->i_assoc_inode;
661 
662 	down_write(&mi->mi_sem);
663 	nilfs_release_frozen_buffers(shadow);
664 	truncate_inode_pages(shadow->inode->i_mapping, 0);
665 	truncate_inode_pages(shadow_btnc_inode->i_mapping, 0);
666 	up_write(&mi->mi_sem);
667 }
668