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 "btree.h"
29 #include "direct.h"
30 #include "btnode.h"
31 #include "mdt.h"
32 #include "dat.h"
33 #include "alloc.h"
34 
nilfs_bmap_get_dat(const struct nilfs_bmap * bmap)35 struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *bmap)
36 {
37 	return NILFS_I_NILFS(bmap->b_inode)->ns_dat;
38 }
39 
nilfs_bmap_convert_error(struct nilfs_bmap * bmap,const char * fname,int err)40 static int nilfs_bmap_convert_error(struct nilfs_bmap *bmap,
41 				     const char *fname, int err)
42 {
43 	struct inode *inode = bmap->b_inode;
44 
45 	if (err == -EINVAL) {
46 		nilfs_error(inode->i_sb, fname,
47 			    "broken bmap (inode number=%lu)\n", inode->i_ino);
48 		err = -EIO;
49 	}
50 	return err;
51 }
52 
53 /**
54  * nilfs_bmap_lookup_at_level - find a data block or node block
55  * @bmap: bmap
56  * @key: key
57  * @level: level
58  * @ptrp: place to store the value associated to @key
59  *
60  * Description: nilfs_bmap_lookup_at_level() finds a record whose key
61  * matches @key in the block at @level of the bmap.
62  *
63  * Return Value: On success, 0 is returned and the record associated with @key
64  * is stored in the place pointed by @ptrp. On error, one of the following
65  * negative error codes is returned.
66  *
67  * %-EIO - I/O error.
68  *
69  * %-ENOMEM - Insufficient amount of memory available.
70  *
71  * %-ENOENT - A record associated with @key does not exist.
72  */
nilfs_bmap_lookup_at_level(struct nilfs_bmap * bmap,__u64 key,int level,__u64 * ptrp)73 int nilfs_bmap_lookup_at_level(struct nilfs_bmap *bmap, __u64 key, int level,
74 			       __u64 *ptrp)
75 {
76 	sector_t blocknr;
77 	int ret;
78 
79 	down_read(&bmap->b_sem);
80 	ret = bmap->b_ops->bop_lookup(bmap, key, level, ptrp);
81 	if (ret < 0) {
82 		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
83 		goto out;
84 	}
85 	if (NILFS_BMAP_USE_VBN(bmap)) {
86 		ret = nilfs_dat_translate(nilfs_bmap_get_dat(bmap), *ptrp,
87 					  &blocknr);
88 		if (!ret)
89 			*ptrp = blocknr;
90 	}
91 
92  out:
93 	up_read(&bmap->b_sem);
94 	return ret;
95 }
96 
nilfs_bmap_lookup_contig(struct nilfs_bmap * bmap,__u64 key,__u64 * ptrp,unsigned maxblocks)97 int nilfs_bmap_lookup_contig(struct nilfs_bmap *bmap, __u64 key, __u64 *ptrp,
98 			     unsigned maxblocks)
99 {
100 	int ret;
101 
102 	down_read(&bmap->b_sem);
103 	ret = bmap->b_ops->bop_lookup_contig(bmap, key, ptrp, maxblocks);
104 	up_read(&bmap->b_sem);
105 
106 	return nilfs_bmap_convert_error(bmap, __func__, ret);
107 }
108 
nilfs_bmap_do_insert(struct nilfs_bmap * bmap,__u64 key,__u64 ptr)109 static int nilfs_bmap_do_insert(struct nilfs_bmap *bmap, __u64 key, __u64 ptr)
110 {
111 	__u64 keys[NILFS_BMAP_SMALL_HIGH + 1];
112 	__u64 ptrs[NILFS_BMAP_SMALL_HIGH + 1];
113 	int ret, n;
114 
115 	if (bmap->b_ops->bop_check_insert != NULL) {
116 		ret = bmap->b_ops->bop_check_insert(bmap, key);
117 		if (ret > 0) {
118 			n = bmap->b_ops->bop_gather_data(
119 				bmap, keys, ptrs, NILFS_BMAP_SMALL_HIGH + 1);
120 			if (n < 0)
121 				return n;
122 			ret = nilfs_btree_convert_and_insert(
123 				bmap, key, ptr, keys, ptrs, n);
124 			if (ret == 0)
125 				bmap->b_u.u_flags |= NILFS_BMAP_LARGE;
126 
127 			return ret;
128 		} else if (ret < 0)
129 			return ret;
130 	}
131 
132 	return bmap->b_ops->bop_insert(bmap, key, ptr);
133 }
134 
135 /**
136  * nilfs_bmap_insert - insert a new key-record pair into a bmap
137  * @bmap: bmap
138  * @key: key
139  * @rec: record
140  *
141  * Description: nilfs_bmap_insert() inserts the new key-record pair specified
142  * by @key and @rec into @bmap.
143  *
144  * Return Value: On success, 0 is returned. On error, one of the following
145  * negative error codes is returned.
146  *
147  * %-EIO - I/O error.
148  *
149  * %-ENOMEM - Insufficient amount of memory available.
150  *
151  * %-EEXIST - A record associated with @key already exist.
152  */
nilfs_bmap_insert(struct nilfs_bmap * bmap,unsigned long key,unsigned long rec)153 int nilfs_bmap_insert(struct nilfs_bmap *bmap,
154 		      unsigned long key,
155 		      unsigned long rec)
156 {
157 	int ret;
158 
159 	down_write(&bmap->b_sem);
160 	ret = nilfs_bmap_do_insert(bmap, key, rec);
161 	up_write(&bmap->b_sem);
162 
163 	return nilfs_bmap_convert_error(bmap, __func__, ret);
164 }
165 
nilfs_bmap_do_delete(struct nilfs_bmap * bmap,__u64 key)166 static int nilfs_bmap_do_delete(struct nilfs_bmap *bmap, __u64 key)
167 {
168 	__u64 keys[NILFS_BMAP_LARGE_LOW + 1];
169 	__u64 ptrs[NILFS_BMAP_LARGE_LOW + 1];
170 	int ret, n;
171 
172 	if (bmap->b_ops->bop_check_delete != NULL) {
173 		ret = bmap->b_ops->bop_check_delete(bmap, key);
174 		if (ret > 0) {
175 			n = bmap->b_ops->bop_gather_data(
176 				bmap, keys, ptrs, NILFS_BMAP_LARGE_LOW + 1);
177 			if (n < 0)
178 				return n;
179 			ret = nilfs_direct_delete_and_convert(
180 				bmap, key, keys, ptrs, n);
181 			if (ret == 0)
182 				bmap->b_u.u_flags &= ~NILFS_BMAP_LARGE;
183 
184 			return ret;
185 		} else if (ret < 0)
186 			return ret;
187 	}
188 
189 	return bmap->b_ops->bop_delete(bmap, key);
190 }
191 
nilfs_bmap_last_key(struct nilfs_bmap * bmap,unsigned long * key)192 int nilfs_bmap_last_key(struct nilfs_bmap *bmap, unsigned long *key)
193 {
194 	__u64 lastkey;
195 	int ret;
196 
197 	down_read(&bmap->b_sem);
198 	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
199 	up_read(&bmap->b_sem);
200 
201 	if (ret < 0)
202 		ret = nilfs_bmap_convert_error(bmap, __func__, ret);
203 	else
204 		*key = lastkey;
205 	return ret;
206 }
207 
208 /**
209  * nilfs_bmap_delete - delete a key-record pair from a bmap
210  * @bmap: bmap
211  * @key: key
212  *
213  * Description: nilfs_bmap_delete() deletes the key-record pair specified by
214  * @key from @bmap.
215  *
216  * Return Value: On success, 0 is returned. On error, one of the following
217  * negative error codes is returned.
218  *
219  * %-EIO - I/O error.
220  *
221  * %-ENOMEM - Insufficient amount of memory available.
222  *
223  * %-ENOENT - A record associated with @key does not exist.
224  */
nilfs_bmap_delete(struct nilfs_bmap * bmap,unsigned long key)225 int nilfs_bmap_delete(struct nilfs_bmap *bmap, unsigned long key)
226 {
227 	int ret;
228 
229 	down_write(&bmap->b_sem);
230 	ret = nilfs_bmap_do_delete(bmap, key);
231 	up_write(&bmap->b_sem);
232 
233 	return nilfs_bmap_convert_error(bmap, __func__, ret);
234 }
235 
nilfs_bmap_do_truncate(struct nilfs_bmap * bmap,unsigned long key)236 static int nilfs_bmap_do_truncate(struct nilfs_bmap *bmap, unsigned long key)
237 {
238 	__u64 lastkey;
239 	int ret;
240 
241 	ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
242 	if (ret < 0) {
243 		if (ret == -ENOENT)
244 			ret = 0;
245 		return ret;
246 	}
247 
248 	while (key <= lastkey) {
249 		ret = nilfs_bmap_do_delete(bmap, lastkey);
250 		if (ret < 0)
251 			return ret;
252 		ret = bmap->b_ops->bop_last_key(bmap, &lastkey);
253 		if (ret < 0) {
254 			if (ret == -ENOENT)
255 				ret = 0;
256 			return ret;
257 		}
258 	}
259 	return 0;
260 }
261 
262 /**
263  * nilfs_bmap_truncate - truncate a bmap to a specified key
264  * @bmap: bmap
265  * @key: key
266  *
267  * Description: nilfs_bmap_truncate() removes key-record pairs whose keys are
268  * greater than or equal to @key from @bmap.
269  *
270  * Return Value: On success, 0 is returned. On error, one of the following
271  * negative error codes is returned.
272  *
273  * %-EIO - I/O error.
274  *
275  * %-ENOMEM - Insufficient amount of memory available.
276  */
nilfs_bmap_truncate(struct nilfs_bmap * bmap,unsigned long key)277 int nilfs_bmap_truncate(struct nilfs_bmap *bmap, unsigned long key)
278 {
279 	int ret;
280 
281 	down_write(&bmap->b_sem);
282 	ret = nilfs_bmap_do_truncate(bmap, key);
283 	up_write(&bmap->b_sem);
284 
285 	return nilfs_bmap_convert_error(bmap, __func__, ret);
286 }
287 
288 /**
289  * nilfs_bmap_clear - free resources a bmap holds
290  * @bmap: bmap
291  *
292  * Description: nilfs_bmap_clear() frees resources associated with @bmap.
293  */
nilfs_bmap_clear(struct nilfs_bmap * bmap)294 void nilfs_bmap_clear(struct nilfs_bmap *bmap)
295 {
296 	down_write(&bmap->b_sem);
297 	if (bmap->b_ops->bop_clear != NULL)
298 		bmap->b_ops->bop_clear(bmap);
299 	up_write(&bmap->b_sem);
300 }
301 
302 /**
303  * nilfs_bmap_propagate - propagate dirty state
304  * @bmap: bmap
305  * @bh: buffer head
306  *
307  * Description: nilfs_bmap_propagate() marks the buffers that directly or
308  * indirectly refer to the block specified by @bh dirty.
309  *
310  * Return Value: On success, 0 is returned. On error, one of the following
311  * negative error codes is returned.
312  *
313  * %-EIO - I/O error.
314  *
315  * %-ENOMEM - Insufficient amount of memory available.
316  */
nilfs_bmap_propagate(struct nilfs_bmap * bmap,struct buffer_head * bh)317 int nilfs_bmap_propagate(struct nilfs_bmap *bmap, struct buffer_head *bh)
318 {
319 	int ret;
320 
321 	down_write(&bmap->b_sem);
322 	ret = bmap->b_ops->bop_propagate(bmap, bh);
323 	up_write(&bmap->b_sem);
324 
325 	return nilfs_bmap_convert_error(bmap, __func__, ret);
326 }
327 
328 /**
329  * nilfs_bmap_lookup_dirty_buffers -
330  * @bmap: bmap
331  * @listp: pointer to buffer head list
332  */
nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap * bmap,struct list_head * listp)333 void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *bmap,
334 				     struct list_head *listp)
335 {
336 	if (bmap->b_ops->bop_lookup_dirty_buffers != NULL)
337 		bmap->b_ops->bop_lookup_dirty_buffers(bmap, listp);
338 }
339 
340 /**
341  * nilfs_bmap_assign - assign a new block number to a block
342  * @bmap: bmap
343  * @bhp: pointer to buffer head
344  * @blocknr: block number
345  * @binfo: block information
346  *
347  * Description: nilfs_bmap_assign() assigns the block number @blocknr to the
348  * buffer specified by @bh.
349  *
350  * Return Value: On success, 0 is returned and the buffer head of a newly
351  * create buffer and the block information associated with the buffer are
352  * stored in the place pointed by @bh and @binfo, respectively. On error, one
353  * of the following negative error codes is returned.
354  *
355  * %-EIO - I/O error.
356  *
357  * %-ENOMEM - Insufficient amount of memory available.
358  */
nilfs_bmap_assign(struct nilfs_bmap * bmap,struct buffer_head ** bh,unsigned long blocknr,union nilfs_binfo * binfo)359 int nilfs_bmap_assign(struct nilfs_bmap *bmap,
360 		      struct buffer_head **bh,
361 		      unsigned long blocknr,
362 		      union nilfs_binfo *binfo)
363 {
364 	int ret;
365 
366 	down_write(&bmap->b_sem);
367 	ret = bmap->b_ops->bop_assign(bmap, bh, blocknr, binfo);
368 	up_write(&bmap->b_sem);
369 
370 	return nilfs_bmap_convert_error(bmap, __func__, ret);
371 }
372 
373 /**
374  * nilfs_bmap_mark - mark block dirty
375  * @bmap: bmap
376  * @key: key
377  * @level: level
378  *
379  * Description: nilfs_bmap_mark() marks the block specified by @key and @level
380  * as dirty.
381  *
382  * Return Value: On success, 0 is returned. On error, one of the following
383  * negative error codes is returned.
384  *
385  * %-EIO - I/O error.
386  *
387  * %-ENOMEM - Insufficient amount of memory available.
388  */
nilfs_bmap_mark(struct nilfs_bmap * bmap,__u64 key,int level)389 int nilfs_bmap_mark(struct nilfs_bmap *bmap, __u64 key, int level)
390 {
391 	int ret;
392 
393 	if (bmap->b_ops->bop_mark == NULL)
394 		return 0;
395 
396 	down_write(&bmap->b_sem);
397 	ret = bmap->b_ops->bop_mark(bmap, key, level);
398 	up_write(&bmap->b_sem);
399 
400 	return nilfs_bmap_convert_error(bmap, __func__, ret);
401 }
402 
403 /**
404  * nilfs_bmap_test_and_clear_dirty - test and clear a bmap dirty state
405  * @bmap: bmap
406  *
407  * Description: nilfs_test_and_clear() is the atomic operation to test and
408  * clear the dirty state of @bmap.
409  *
410  * Return Value: 1 is returned if @bmap is dirty, or 0 if clear.
411  */
nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap * bmap)412 int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *bmap)
413 {
414 	int ret;
415 
416 	down_write(&bmap->b_sem);
417 	ret = nilfs_bmap_dirty(bmap);
418 	nilfs_bmap_clear_dirty(bmap);
419 	up_write(&bmap->b_sem);
420 	return ret;
421 }
422 
423 
424 /*
425  * Internal use only
426  */
nilfs_bmap_data_get_key(const struct nilfs_bmap * bmap,const struct buffer_head * bh)427 __u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *bmap,
428 			      const struct buffer_head *bh)
429 {
430 	struct buffer_head *pbh;
431 	__u64 key;
432 
433 	key = page_index(bh->b_page) << (PAGE_CACHE_SHIFT -
434 					 bmap->b_inode->i_blkbits);
435 	for (pbh = page_buffers(bh->b_page); pbh != bh; pbh = pbh->b_this_page)
436 		key++;
437 
438 	return key;
439 }
440 
nilfs_bmap_find_target_seq(const struct nilfs_bmap * bmap,__u64 key)441 __u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *bmap, __u64 key)
442 {
443 	__s64 diff;
444 
445 	diff = key - bmap->b_last_allocated_key;
446 	if ((nilfs_bmap_keydiff_abs(diff) < NILFS_INODE_BMAP_SIZE) &&
447 	    (bmap->b_last_allocated_ptr != NILFS_BMAP_INVALID_PTR) &&
448 	    (bmap->b_last_allocated_ptr + diff > 0))
449 		return bmap->b_last_allocated_ptr + diff;
450 	else
451 		return NILFS_BMAP_INVALID_PTR;
452 }
453 
454 #define NILFS_BMAP_GROUP_DIV	8
nilfs_bmap_find_target_in_group(const struct nilfs_bmap * bmap)455 __u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *bmap)
456 {
457 	struct inode *dat = nilfs_bmap_get_dat(bmap);
458 	unsigned long entries_per_group = nilfs_palloc_entries_per_group(dat);
459 	unsigned long group = bmap->b_inode->i_ino / entries_per_group;
460 
461 	return group * entries_per_group +
462 		(bmap->b_inode->i_ino % NILFS_BMAP_GROUP_DIV) *
463 		(entries_per_group / NILFS_BMAP_GROUP_DIV);
464 }
465 
466 static struct lock_class_key nilfs_bmap_dat_lock_key;
467 static struct lock_class_key nilfs_bmap_mdt_lock_key;
468 
469 /**
470  * nilfs_bmap_read - read a bmap from an inode
471  * @bmap: bmap
472  * @raw_inode: on-disk inode
473  *
474  * Description: nilfs_bmap_read() initializes the bmap @bmap.
475  *
476  * Return Value: On success, 0 is returned. On error, the following negative
477  * error code is returned.
478  *
479  * %-ENOMEM - Insufficient amount of memory available.
480  */
nilfs_bmap_read(struct nilfs_bmap * bmap,struct nilfs_inode * raw_inode)481 int nilfs_bmap_read(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
482 {
483 	if (raw_inode == NULL)
484 		memset(bmap->b_u.u_data, 0, NILFS_BMAP_SIZE);
485 	else
486 		memcpy(bmap->b_u.u_data, raw_inode->i_bmap, NILFS_BMAP_SIZE);
487 
488 	init_rwsem(&bmap->b_sem);
489 	bmap->b_state = 0;
490 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
491 	switch (bmap->b_inode->i_ino) {
492 	case NILFS_DAT_INO:
493 		bmap->b_ptr_type = NILFS_BMAP_PTR_P;
494 		bmap->b_last_allocated_key = 0;
495 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
496 		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_dat_lock_key);
497 		break;
498 	case NILFS_CPFILE_INO:
499 	case NILFS_SUFILE_INO:
500 		bmap->b_ptr_type = NILFS_BMAP_PTR_VS;
501 		bmap->b_last_allocated_key = 0;
502 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
503 		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
504 		break;
505 	case NILFS_IFILE_INO:
506 		lockdep_set_class(&bmap->b_sem, &nilfs_bmap_mdt_lock_key);
507 		/* Fall through */
508 	default:
509 		bmap->b_ptr_type = NILFS_BMAP_PTR_VM;
510 		bmap->b_last_allocated_key = 0;
511 		bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
512 		break;
513 	}
514 
515 	return (bmap->b_u.u_flags & NILFS_BMAP_LARGE) ?
516 		nilfs_btree_init(bmap) : nilfs_direct_init(bmap);
517 }
518 
519 /**
520  * nilfs_bmap_write - write back a bmap to an inode
521  * @bmap: bmap
522  * @raw_inode: on-disk inode
523  *
524  * Description: nilfs_bmap_write() stores @bmap in @raw_inode.
525  */
nilfs_bmap_write(struct nilfs_bmap * bmap,struct nilfs_inode * raw_inode)526 void nilfs_bmap_write(struct nilfs_bmap *bmap, struct nilfs_inode *raw_inode)
527 {
528 	down_write(&bmap->b_sem);
529 	memcpy(raw_inode->i_bmap, bmap->b_u.u_data,
530 	       NILFS_INODE_BMAP_SIZE * sizeof(__le64));
531 	if (bmap->b_inode->i_ino == NILFS_DAT_INO)
532 		bmap->b_last_allocated_ptr = NILFS_BMAP_NEW_PTR_INIT;
533 
534 	up_write(&bmap->b_sem);
535 }
536 
nilfs_bmap_init_gc(struct nilfs_bmap * bmap)537 void nilfs_bmap_init_gc(struct nilfs_bmap *bmap)
538 {
539 	memset(&bmap->b_u, 0, NILFS_BMAP_SIZE);
540 	init_rwsem(&bmap->b_sem);
541 	bmap->b_inode = &NILFS_BMAP_I(bmap)->vfs_inode;
542 	bmap->b_ptr_type = NILFS_BMAP_PTR_U;
543 	bmap->b_last_allocated_key = 0;
544 	bmap->b_last_allocated_ptr = NILFS_BMAP_INVALID_PTR;
545 	bmap->b_state = 0;
546 	nilfs_btree_init_gc(bmap);
547 }
548 
nilfs_bmap_save(const struct nilfs_bmap * bmap,struct nilfs_bmap_store * store)549 void nilfs_bmap_save(const struct nilfs_bmap *bmap,
550 		     struct nilfs_bmap_store *store)
551 {
552 	memcpy(store->data, bmap->b_u.u_data, sizeof(store->data));
553 	store->last_allocated_key = bmap->b_last_allocated_key;
554 	store->last_allocated_ptr = bmap->b_last_allocated_ptr;
555 	store->state = bmap->b_state;
556 }
557 
nilfs_bmap_restore(struct nilfs_bmap * bmap,const struct nilfs_bmap_store * store)558 void nilfs_bmap_restore(struct nilfs_bmap *bmap,
559 			const struct nilfs_bmap_store *store)
560 {
561 	memcpy(bmap->b_u.u_data, store->data, sizeof(store->data));
562 	bmap->b_last_allocated_key = store->last_allocated_key;
563 	bmap->b_last_allocated_ptr = store->last_allocated_ptr;
564 	bmap->b_state = store->state;
565 }
566