xref: /openbmc/linux/fs/nilfs2/bmap.c (revision b04b4f78)
1 /*
2  * bmap.c - NILFS block mapping.
3  *
4  * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
5  *
6  * This program is free software; you can redistribute it and/or modify
7  * it under the terms of the GNU General Public License as published by
8  * the Free Software Foundation; either version 2 of the License, or
9  * (at your option) any later version.
10  *
11  * This program is distributed in the hope that it will be useful,
12  * but WITHOUT ANY WARRANTY; without even the implied warranty of
13  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
14  * GNU General Public License for more details.
15  *
16  * You should have received a copy of the GNU General Public License
17  * along with this program; if not, write to the Free Software
18  * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
19  *
20  * Written by Koji Sato <koji@osrg.net>.
21  */
22 
23 #include <linux/fs.h>
24 #include <linux/string.h>
25 #include <linux/errno.h>
26 #include "nilfs.h"
27 #include "bmap.h"
28 #include "sb.h"
29 #include "btnode.h"
30 #include "mdt.h"
31 #include "dat.h"
32 #include "alloc.h"
33 
34 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
35 			       __u64 *ptrp)
36 {
37 	__u64 ptr;
38 	int ret;
39 
40 	down_read(&bmap->b_sem);
41 	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
42 	if (ret < 0)
43 		goto out;
44 	if (bmap->b_pops->bpop_translate != NULL) {
45 		ret = bmap->b_pops->bpop_translate(bmap, *ptrp, &ptr);
46 		if (ret < 0)
47 			goto out;
48 		*ptrp = ptr;
49 	}
50 
51  out:
52 	up_read(&bmap->b_sem);
53 	return ret;
54 }
55 
56 
57 /**
58  * nilfs_bmap_lookup - find a record
59  * @bmap: bmap
60  * @key: key
61  * @recp: pointer to record
62  *
63  * Description: nilfs_bmap_lookup() finds a record whose key matches @key in
64  * @bmap.
65  *
66  * Return Value: On success, 0 is returned and the record associated with @key
67  * is stored in the place pointed by @recp. On error, one of the following
68  * negative error codes is returned.
69  *
70  * %-EIO - I/O error.
71  *
72  * %-ENOMEM - Insufficient amount of memory available.
73  *
74  * %-ENOENT - A record associated with @key does not exist.
75  */
76 int nilfs_bmap_lookup(struct nilfs_bmap *bmap,
77 		      unsigned long key,
78 		      unsigned long *recp)
79 {
80 	__u64 ptr;
81 	int ret;
82 
83 	/* XXX: use macro for level 1 */
84 	ret = nilfs_bmap_lookup_at_level(bmap, key, 1, &ptr);
85 	if (recp != NULL)
86 		*recp = ptr;
87 	return ret;
88 }
89 
90 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
91 {
92 	__u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
93 	__u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
94 	int ret, n;
95 
96 	if (bmap->b_ops->bop_check_insert != NULL) {
97 		ret = bmap->b_ops->bop_check_insert(bmap, key);
98 		if (ret > 0) {
99 			n = bmap->b_ops->bop_gather_data(
100 				bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
101 			if (n < 0)
102 				return n;
103 			ret = nilfs_btree_convert_and_insert(
104 				bmap, key, ptr, keys, ptrs, n,
105 				NILFS_BMAP_LARGE_LOW, NILFS_BMAP_LARGE_HIGH);
106 			if (ret == 0)
107 				bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
108 
109 			return ret;
110 		} else if (ret < 0)
111 			return ret;
112 	}
113 
114 	return bmap->b_ops->bop_insert(bmap, key, ptr);
115 }
116 
117 /**
118  * nilfs_bmap_insert - insert a new key-record pair into a bmap
119  * @bmap: bmap
120  * @key: key
121  * @rec: record
122  *
123  * Description: nilfs_bmap_insert() inserts the new key-record pair specified
124  * by @key and @rec into @bmap.
125  *
126  * Return Value: On success, 0 is returned. On error, one of the following
127  * negative error codes is returned.
128  *
129  * %-EIO - I/O error.
130  *
131  * %-ENOMEM - Insufficient amount of memory available.
132  *
133  * %-EEXIST - A record associated with @key already exist.
134  */
135 int nilfs_bmap_insert(struct nilfs_bmap *bmap,
136 		      unsigned long key,
137 		      unsigned long rec)
138 {
139 	int ret;
140 
141 	down_write(&bmap->b_sem);
142 	ret = nilfs_bmap_do_insert(bmap, key, rec);
143 	up_write(&bmap->b_sem);
144 	return ret;
145 }
146 
147 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
148 {
149 	__u64 keys[NILFS_BMAP_LARGE_LOW + 1];
150 	__u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
151 	int ret, n;
152 
153 	if (bmap->b_ops->bop_check_delete != NULL) {
154 		ret = bmap->b_ops->bop_check_delete(bmap, key);
155 		if (ret > 0) {
156 			n = bmap->b_ops->bop_gather_data(
157 				bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
158 			if (n < 0)
159 				return n;
160 			ret = nilfs_direct_delete_and_convert(
161 				bmap, key, keys, ptrs, n,
162 				NILFS_BMAP_SMALL_LOW, NILFS_BMAP_SMALL_HIGH);
163 			if (ret == 0)
164 				bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
165 
166 			return ret;
167 		} else if (ret < 0)
168 			return ret;
169 	}
170 
171 	return bmap->b_ops->bop_delete(bmap, key);
172 }
173 
174 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
175 {
176 	__u64 lastkey;
177 	int ret;
178 
179 	down_read(&bmap->b_sem);
180 	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
181 	if (!ret)
182 		*key = lastkey;
183 	up_read(&bmap->b_sem);
184 	return ret;
185 }
186 
187 /**
188  * nilfs_bmap_delete - delete a key-record pair from a bmap
189  * @bmap: bmap
190  * @key: key
191  *
192  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
193  * @key from @bmap.
194  *
195  * Return Value: On success, 0 is returned. On error, one of the following
196  * negative error codes is returned.
197  *
198  * %-EIO - I/O error.
199  *
200  * %-ENOMEM - Insufficient amount of memory available.
201  *
202  * %-ENOENT - A record associated with @key does not exist.
203  */
204 int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
205 {
206 	int ret;
207 
208 	down_write(&bmap->b_sem);
209 	ret = nilfs_bmap_do_delete(bmap, key);
210 	up_write(&bmap->b_sem);
211 	return ret;
212 }
213 
214 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
215 {
216 	__u64 lastkey;
217 	int ret;
218 
219 	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
220 	if (ret < 0) {
221 		if (ret == -ENOENT)
222 			ret = 0;
223 		return ret;
224 	}
225 
226 	while (key <= lastkey) {
227 		ret = nilfs_bmap_do_delete(bmap, lastkey);
228 		if (ret < 0)
229 			return ret;
230 		ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
231 		if (ret < 0) {
232 			if (ret == -ENOENT)
233 				ret = 0;
234 			return ret;
235 		}
236 	}
237 	return 0;
238 }
239 
240 /**
241  * nilfs_bmap_truncate - truncate a bmap to a specified key
242  * @bmap: bmap
243  * @key: key
244  *
245  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
246  * greater than or equal to @key from @bmap.
247  *
248  * Return Value: On success, 0 is returned. On error, one of the following
249  * negative error codes is returned.
250  *
251  * %-EIO - I/O error.
252  *
253  * %-ENOMEM - Insufficient amount of memory available.
254  */
255 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
256 {
257 	int ret;
258 
259 	down_write(&bmap->b_sem);
260 	ret = nilfs_bmap_do_truncate(bmap, key);
261 	up_write(&bmap->b_sem);
262 	return ret;
263 }
264 
265 /**
266  * nilfs_bmap_clear - free resources a bmap holds
267  * @bmap: bmap
268  *
269  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
270  */
271 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
272 {
273 	down_write(&bmap->b_sem);
274 	if (bmap->b_ops->bop_clear != NULL)
275 		bmap->b_ops->bop_clear(bmap);
276 	up_write(&bmap->b_sem);
277 }
278 
279 /**
280  * nilfs_bmap_propagate - propagate dirty state
281  * @bmap: bmap
282  * @bh: buffer head
283  *
284  * Description: nilfs_bmap_propagate() marks the buffers that directly or
285  * indirectly refer to the block specified by @bh dirty.
286  *
287  * Return Value: On success, 0 is returned. On error, one of the following
288  * negative error codes is returned.
289  *
290  * %-EIO - I/O error.
291  *
292  * %-ENOMEM - Insufficient amount of memory available.
293  */
294 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
295 {
296 	int ret;
297 
298 	down_write(&bmap->b_sem);
299 	ret = bmap->b_ops->bop_propagate(bmap, bh);
300 	up_write(&bmap->b_sem);
301 	return ret;
302 }
303 
304 /**
305  * nilfs_bmap_lookup_dirty_buffers -
306  * @bmap: bmap
307  * @listp: pointer to buffer head list
308  */
309 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
310 				     struct list_head *listp)
311 {
312 	if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
313 		bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
314 }
315 
316 /**
317  * nilfs_bmap_assign - assign a new block number to a block
318  * @bmap: bmap
319  * @bhp: pointer to buffer head
320  * @blocknr: block number
321  * @binfo: block information
322  *
323  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
324  * buffer specified by @bh.
325  *
326  * Return Value: On success, 0 is returned and the buffer head of a newly
327  * create buffer and the block information associated with the buffer are
328  * stored in the place pointed by @bh and @binfo, respectively. On error, one
329  * of the following negative error codes is returned.
330  *
331  * %-EIO - I/O error.
332  *
333  * %-ENOMEM - Insufficient amount of memory available.
334  */
335 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
336 		      struct buffer_head **bh,
337 		      unsigned long blocknr,
338 		      union nilfs_binfo *binfo)
339 {
340 	int ret;
341 
342 	down_write(&bmap->b_sem);
343 	ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
344 	up_write(&bmap->b_sem);
345 	return ret;
346 }
347 
348 /**
349  * nilfs_bmap_mark - mark block dirty
350  * @bmap: bmap
351  * @key: key
352  * @level: level
353  *
354  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
355  * as dirty.
356  *
357  * Return Value: On success, 0 is returned. On error, one of the following
358  * negative error codes is returned.
359  *
360  * %-EIO - I/O error.
361  *
362  * %-ENOMEM - Insufficient amount of memory available.
363  */
364 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
365 {
366 	int ret;
367 
368 	if (bmap->b_ops->bop_mark == NULL)
369 		return 0;
370 
371 	down_write(&bmap->b_sem);
372 	ret = bmap->b_ops->bop_mark(bmap, key, level);
373 	up_write(&bmap->b_sem);
374 	return ret;
375 }
376 
377 /**
378  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
379  * @bmap: bmap
380  *
381  * Description: nilfs_test_and_clear() is the atomic operation to test and
382  * clear the dirty state of @bmap.
383  *
384  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
385  */
386 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
387 {
388 	int ret;
389 
390 	down_write(&bmap->b_sem);
391 	ret = nilfs_bmap_dirty(bmap);
392 	nilfs_bmap_clear_dirty(bmap);
393 	up_write(&bmap->b_sem);
394 	return ret;
395 }
396 
397 
398 /*
399  * Internal use only
400  */
401 
402 void nilfs_bmap_add_blocks(const struct nilfs_bmap *bmap, int n)
403 {
404 	inode_add_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
405 	if (NILFS_MDT(bmap->b_inode))
406 		nilfs_mdt_mark_dirty(bmap->b_inode);
407 	else
408 		mark_inode_dirty(bmap->b_inode);
409 }
410 
411 void nilfs_bmap_sub_blocks(const struct nilfs_bmap *bmap, int n)
412 {
413 	inode_sub_bytes(bmap->b_inode, (1 << bmap->b_inode->i_blkbits) * n);
414 	if (NILFS_MDT(bmap->b_inode))
415 		nilfs_mdt_mark_dirty(bmap->b_inode);
416 	else
417 		mark_inode_dirty(bmap->b_inode);
418 }
419 
420 int nilfs_bmap_get_block(const struct nilfs_bmap *bmap, __u64 ptr,
421 			 struct buffer_head **bhp)
422 {
423 	return nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
424 				ptr, 0, bhp, 0);
425 }
426 
427 void nilfs_bmap_put_block(const struct nilfs_bmap *bmap,
428 			  struct buffer_head *bh)
429 {
430 	brelse(bh);
431 }
432 
433 int nilfs_bmap_get_new_block(const struct nilfs_bmap *bmap, __u64 ptr,
434 			     struct buffer_head **bhp)
435 {
436 	int ret;
437 
438 	ret = nilfs_btnode_get(&NILFS_BMAP_I(bmap)->i_btnode_cache,
439 			       ptr, 0, bhp, 1);
440 	if (ret < 0)
441 		return ret;
442 	set_buffer_nilfs_volatile(*bhp);
443 	return 0;
444 }
445 
446 void nilfs_bmap_delete_block(const struct nilfs_bmap *bmap,
447 			     struct buffer_head *bh)
448 {
449 	nilfs_btnode_delete(bh);
450 }
451 
452 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
453 			      const struct buffer_head *bh)
454 {
455 	struct buffer_head *pbh;
456 	__u64 key;
457 
458 	key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
459 					 bmap->b_inode->i_blkbits);
460 	for (pbh = page_buffers(bh->b_page); pbh != bh;
461 	     pbh = pbh->b_this_page, key++);
462 
463 	return key;
464 }
465 
466 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
467 {
468 	__s64 diff;
469 
470 	diff = key - bmap->b_last_allocated_key;
471 	if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
472 	    (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
473 	    (bmap->b_last_allocated_ptr + diff > 0))
474 		return bmap->b_last_allocated_ptr + diff;
475 	else
476 		return NILFS_BMAP_INVALID_PTR;
477 }
478 
479 static struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
480 {
481 	return nilfs_dat_inode(NILFS_I_NILFS(bmap->b_inode));
482 }
483 
484 #define NILFS_BMAP_GROUP_DIV	8
485 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
486 {
487 	struct inode *dat = nilfs_bmap_get_dat(bmap);
488 	unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
489 	unsigned long group = bmap->b_inode->i_ino / entries_per_group;
490 
491 	return group * entries_per_group +
492 		(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
493 		(entries_per_group / NILFS_BMAP_GROUP_DIV);
494 }
495 
496 static int nilfs_bmap_prepare_alloc_v(struct nilfs_bmap *bmap,
497 				      union nilfs_bmap_ptr_req *req)
498 {
499 	return nilfs_dat_prepare_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
500 }
501 
502 static void nilfs_bmap_commit_alloc_v(struct nilfs_bmap *bmap,
503 				      union nilfs_bmap_ptr_req *req)
504 {
505 	nilfs_dat_commit_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
506 }
507 
508 static void nilfs_bmap_abort_alloc_v(struct nilfs_bmap *bmap,
509 				     union nilfs_bmap_ptr_req *req)
510 {
511 	nilfs_dat_abort_alloc(nilfs_bmap_get_dat(bmap), &req->bpr_req);
512 }
513 
514 static int nilfs_bmap_prepare_start_v(struct nilfs_bmap *bmap,
515 				      union nilfs_bmap_ptr_req *req)
516 {
517 	return nilfs_dat_prepare_start(nilfs_bmap_get_dat(bmap), &req->bpr_req);
518 }
519 
520 static void nilfs_bmap_commit_start_v(struct nilfs_bmap *bmap,
521 				      union nilfs_bmap_ptr_req *req,
522 				      sector_t blocknr)
523 {
524 	nilfs_dat_commit_start(nilfs_bmap_get_dat(bmap), &req->bpr_req,
525 			       blocknr);
526 }
527 
528 static void nilfs_bmap_abort_start_v(struct nilfs_bmap *bmap,
529 				     union nilfs_bmap_ptr_req *req)
530 {
531 	nilfs_dat_abort_start(nilfs_bmap_get_dat(bmap), &req->bpr_req);
532 }
533 
534 static int nilfs_bmap_prepare_end_v(struct nilfs_bmap *bmap,
535 				    union nilfs_bmap_ptr_req *req)
536 {
537 	return nilfs_dat_prepare_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
538 }
539 
540 static void nilfs_bmap_commit_end_v(struct nilfs_bmap *bmap,
541 				    union nilfs_bmap_ptr_req *req)
542 {
543 	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 0);
544 }
545 
546 static void nilfs_bmap_commit_end_vmdt(struct nilfs_bmap *bmap,
547 				       union nilfs_bmap_ptr_req *req)
548 {
549 	nilfs_dat_commit_end(nilfs_bmap_get_dat(bmap), &req->bpr_req, 1);
550 }
551 
552 static void nilfs_bmap_abort_end_v(struct nilfs_bmap *bmap,
553 				   union nilfs_bmap_ptr_req *req)
554 {
555 	nilfs_dat_abort_end(nilfs_bmap_get_dat(bmap), &req->bpr_req);
556 }
557 
558 int nilfs_bmap_move_v(const struct nilfs_bmap *bmap, __u64 vblocknr,
559 		      sector_t blocknr)
560 {
561 	return nilfs_dat_move(nilfs_bmap_get_dat(bmap), vblocknr, blocknr);
562 }
563 
564 int nilfs_bmap_mark_dirty(const struct nilfs_bmap *bmap, __u64 vblocknr)
565 {
566 	return nilfs_dat_mark_dirty(nilfs_bmap_get_dat(bmap), vblocknr);
567 }
568 
569 int nilfs_bmap_prepare_update(struct nilfs_bmap *bmap,
570 			      union nilfs_bmap_ptr_req *oldreq,
571 			      union nilfs_bmap_ptr_req *newreq)
572 {
573 	int ret;
574 
575 	ret = bmap->b_pops->bpop_prepare_end_ptr(bmap, oldreq);
576 	if (ret < 0)
577 		return ret;
578 	ret = bmap->b_pops->bpop_prepare_alloc_ptr(bmap, newreq);
579 	if (ret < 0)
580 		bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
581 
582 	return ret;
583 }
584 
585 void nilfs_bmap_commit_update(struct nilfs_bmap *bmap,
586 			      union nilfs_bmap_ptr_req *oldreq,
587 			      union nilfs_bmap_ptr_req *newreq)
588 {
589 	bmap->b_pops->bpop_commit_end_ptr(bmap, oldreq);
590 	bmap->b_pops->bpop_commit_alloc_ptr(bmap, newreq);
591 }
592 
593 void nilfs_bmap_abort_update(struct nilfs_bmap *bmap,
594 			     union nilfs_bmap_ptr_req *oldreq,
595 			     union nilfs_bmap_ptr_req *newreq)
596 {
597 	bmap->b_pops->bpop_abort_end_ptr(bmap, oldreq);
598 	bmap->b_pops->bpop_abort_alloc_ptr(bmap, newreq);
599 }
600 
601 static int nilfs_bmap_translate_v(const struct nilfs_bmap *bmap, __u64 ptr,
602 				  __u64 *ptrp)
603 {
604 	sector_t blocknr;
605 	int ret;
606 
607 	ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), ptr, &blocknr);
608 	if (ret < 0)
609 		return ret;
610 	if (ptrp != NULL)
611 		*ptrp = blocknr;
612 	return 0;
613 }
614 
615 static int nilfs_bmap_prepare_alloc_p(struct nilfs_bmap *bmap,
616 				      union nilfs_bmap_ptr_req *req)
617 {
618 	/* ignore target ptr */
619 	req->bpr_ptr = bmap->b_last_allocated_ptr++;
620 	return 0;
621 }
622 
623 static void nilfs_bmap_commit_alloc_p(struct nilfs_bmap *bmap,
624 				      union nilfs_bmap_ptr_req *req)
625 {
626 	/* do nothing */
627 }
628 
629 static void nilfs_bmap_abort_alloc_p(struct nilfs_bmap *bmap,
630 				     union nilfs_bmap_ptr_req *req)
631 {
632 	bmap->b_last_allocated_ptr--;
633 }
634 
635 static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_v = {
636 	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
637 	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
638 	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
639 	.bpop_prepare_start_ptr	=	nilfs_bmap_prepare_start_v,
640 	.bpop_commit_start_ptr	=	nilfs_bmap_commit_start_v,
641 	.bpop_abort_start_ptr	=	nilfs_bmap_abort_start_v,
642 	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
643 	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_v,
644 	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
645 
646 	.bpop_translate		=	nilfs_bmap_translate_v,
647 };
648 
649 static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_vmdt = {
650 	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_v,
651 	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_v,
652 	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_v,
653 	.bpop_prepare_start_ptr	=	nilfs_bmap_prepare_start_v,
654 	.bpop_commit_start_ptr	=	nilfs_bmap_commit_start_v,
655 	.bpop_abort_start_ptr	=	nilfs_bmap_abort_start_v,
656 	.bpop_prepare_end_ptr	=	nilfs_bmap_prepare_end_v,
657 	.bpop_commit_end_ptr	=	nilfs_bmap_commit_end_vmdt,
658 	.bpop_abort_end_ptr	=	nilfs_bmap_abort_end_v,
659 
660 	.bpop_translate		=	nilfs_bmap_translate_v,
661 };
662 
663 static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_p = {
664 	.bpop_prepare_alloc_ptr	=	nilfs_bmap_prepare_alloc_p,
665 	.bpop_commit_alloc_ptr	=	nilfs_bmap_commit_alloc_p,
666 	.bpop_abort_alloc_ptr	=	nilfs_bmap_abort_alloc_p,
667 	.bpop_prepare_start_ptr	=	NULL,
668 	.bpop_commit_start_ptr	=	NULL,
669 	.bpop_abort_start_ptr	=	NULL,
670 	.bpop_prepare_end_ptr	=	NULL,
671 	.bpop_commit_end_ptr	=	NULL,
672 	.bpop_abort_end_ptr	=	NULL,
673 
674 	.bpop_translate		=	NULL,
675 };
676 
677 static const struct nilfs_bmap_ptr_operations nilfs_bmap_ptr_ops_gc = {
678 	.bpop_prepare_alloc_ptr	=	NULL,
679 	.bpop_commit_alloc_ptr	=	NULL,
680 	.bpop_abort_alloc_ptr	=	NULL,
681 	.bpop_prepare_start_ptr	=	NULL,
682 	.bpop_commit_start_ptr	=	NULL,
683 	.bpop_abort_start_ptr	=	NULL,
684 	.bpop_prepare_end_ptr	=	NULL,
685 	.bpop_commit_end_ptr	=	NULL,
686 	.bpop_abort_end_ptr	=	NULL,
687 
688 	.bpop_translate		=	NULL,
689 };
690 
691 static struct lock_class_key nilfs_bmap_dat_lock_key;
692 
693 /**
694  * nilfs_bmap_read - read a bmap from an inode
695  * @bmap: bmap
696  * @raw_inode: on-disk inode
697  *
698  * Description: nilfs_bmap_read() initializes the bmap @bmap.
699  *
700  * Return Value: On success, 0 is returned. On error, the following negative
701  * error code is returned.
702  *
703  * %-ENOMEM - Insufficient amount of memory available.
704  */
705 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
706 {
707 	if (raw_inode == NULL)
708 		memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
709 	else
710 		memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
711 
712 	init_rwsem(&bmap->b_sem);
713 	bmap->b_state = 0;
714 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
715 	switch (bmap->b_inode->i_ino) {
716 	case NILFS_DAT_INO:
717 		bmap->b_pops = &nilfs_bmap_ptr_ops_p;
718 		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
719 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
720 		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
721 		break;
722 	case NILFS_CPFILE_INO:
723 	case NILFS_SUFILE_INO:
724 		bmap->b_pops = &nilfs_bmap_ptr_ops_vmdt;
725 		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
726 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
727 		break;
728 	default:
729 		bmap->b_pops = &nilfs_bmap_ptr_ops_v;
730 		bmap->b_last_allocated_key = 0;	/* XXX: use macro */
731 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
732 		break;
733 	}
734 
735 	return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
736 		nilfs_btree_init(bmap,
737 				 NILFS_BMAP_LARGE_LOW,
738 				 NILFS_BMAP_LARGE_HIGH) :
739 		nilfs_direct_init(bmap,
740 				  NILFS_BMAP_SMALL_LOW,
741 				  NILFS_BMAP_SMALL_HIGH);
742 }
743 
744 /**
745  * nilfs_bmap_write - write back a bmap to an inode
746  * @bmap: bmap
747  * @raw_inode: on-disk inode
748  *
749  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
750  */
751 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
752 {
753 	down_write(&bmap->b_sem);
754 	memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
755 	       NILFS_INODE_BMAP_SIZE * sizeof(__le64));
756 	if (bmap->b_inode->i_ino == NILFS_DAT_INO)
757 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
758 
759 	up_write(&bmap->b_sem);
760 }
761 
762 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
763 {
764 	memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
765 	init_rwsem(&bmap->b_sem);
766 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
767 	bmap->b_pops = &nilfs_bmap_ptr_ops_gc;
768 	bmap->b_last_allocated_key = 0;
769 	bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
770 	bmap->b_state = 0;
771 	nilfs_btree_init_gc(bmap);
772 }
773 
774 void nilfs_bmap_init_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
775 {
776 	memcpy(gcbmap, bmap, sizeof(union nilfs_bmap_union));
777 	init_rwsem(&gcbmap->b_sem);
778 	lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
779 	gcbmap->b_inode = &NILFS_BMAP_I(gcbmap)->vfs_inode;
780 }
781 
782 void nilfs_bmap_commit_gcdat(struct nilfs_bmap *gcbmap, struct nilfs_bmap *bmap)
783 {
784 	memcpy(bmap, gcbmap, sizeof(union nilfs_bmap_union));
785 	init_rwsem(&bmap->b_sem);
786 	lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
787 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
788 }
789