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1/*
2 * alloc.c - NILFS dat/inode allocator
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 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
23 */
24
25#include <linux/types.h>
26#include <linux/buffer_head.h>
27#include <linux/fs.h>
28#include <linux/bitops.h>
29#include <linux/slab.h>
30#include "mdt.h"
31#include "alloc.h"
32
33
34/**
35 * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
36 * descriptor block can maintain
37 * @inode: inode of metadata file using this allocator
38 */
39static inline unsigned long
40nilfs_palloc_groups_per_desc_block(const struct inode *inode)
41{
42 return (1UL << inode->i_blkbits) /
43 sizeof(struct nilfs_palloc_group_desc);
44}
45
46/**
47 * nilfs_palloc_groups_count - get maximum number of groups
48 * @inode: inode of metadata file using this allocator
49 */
50static inline unsigned long
51nilfs_palloc_groups_count(const struct inode *inode)
52{
53 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
54}
55
56/**
57 * nilfs_palloc_init_blockgroup - initialize private variables for allocator
58 * @inode: inode of metadata file using this allocator
59 * @entry_size: size of the persistent object
60 */
61int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
62{
63 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
64
65 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
66 if (!mi->mi_bgl)
67 return -ENOMEM;
68
69 bgl_lock_init(mi->mi_bgl);
70
71 nilfs_mdt_set_entry_size(inode, entry_size, 0);
72
73 mi->mi_blocks_per_group =
74 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
75 mi->mi_entries_per_block) + 1;
76 /* Number of blocks in a group including entry blocks and
77 a bitmap block */
78 mi->mi_blocks_per_desc_block =
79 nilfs_palloc_groups_per_desc_block(inode) *
80 mi->mi_blocks_per_group + 1;
81 /* Number of blocks per descriptor including the
82 descriptor block */
83 return 0;
84}
85
86/**
87 * nilfs_palloc_group - get group number and offset from an entry number
88 * @inode: inode of metadata file using this allocator
89 * @nr: serial number of the entry (e.g. inode number)
90 * @offset: pointer to store offset number in the group
91 */
92static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
93 unsigned long *offset)
94{
95 __u64 group = nr;
96
97 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
98 return group;
99}
100
101/**
102 * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
103 * @inode: inode of metadata file using this allocator
104 * @group: group number
105 *
106 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
107 * block which contains a descriptor of the specified group.
108 */
109static unsigned long
110nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
111{
112 unsigned long desc_block =
113 group / nilfs_palloc_groups_per_desc_block(inode);
114 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
115}
116
117/**
118 * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
119 * @inode: inode of metadata file using this allocator
120 * @group: group number
121 *
122 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
123 * block used to allocate/deallocate entries in the specified group.
124 */
125static unsigned long
126nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
127{
128 unsigned long desc_offset =
129 group % nilfs_palloc_groups_per_desc_block(inode);
130 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
131 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
132}
133
134/**
135 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
136 * @inode: inode of metadata file using this allocator
137 * @group: group number
138 * @desc: pointer to descriptor structure for the group
139 */
140static unsigned long
141nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,
142 const struct nilfs_palloc_group_desc *desc)
143{
144 unsigned long nfree;
145
146 spin_lock(nilfs_mdt_bgl_lock(inode, group));
147 nfree = le32_to_cpu(desc->pg_nfrees);
148 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
149 return nfree;
150}
151
152/**
153 * nilfs_palloc_group_desc_add_entries - adjust count of free entries
154 * @inode: inode of metadata file using this allocator
155 * @group: group number
156 * @desc: pointer to descriptor structure for the group
157 * @n: delta to be added
158 */
159static void
160nilfs_palloc_group_desc_add_entries(struct inode *inode,
161 unsigned long group,
162 struct nilfs_palloc_group_desc *desc,
163 u32 n)
164{
165 spin_lock(nilfs_mdt_bgl_lock(inode, group));
166 le32_add_cpu(&desc->pg_nfrees, n);
167 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
168}
169
170/**
171 * nilfs_palloc_entry_blkoff - get block offset of an entry block
172 * @inode: inode of metadata file using this allocator
173 * @nr: serial number of the entry (e.g. inode number)
174 */
175static unsigned long
176nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
177{
178 unsigned long group, group_offset;
179
180 group = nilfs_palloc_group(inode, nr, &group_offset);
181
182 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
183 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
184}
185
186/**
187 * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
188 * @inode: inode of metadata file
189 * @bh: buffer head of the buffer to be initialized
190 * @kaddr: kernel address mapped for the page including the buffer
191 */
192static void nilfs_palloc_desc_block_init(struct inode *inode,
193 struct buffer_head *bh, void *kaddr)
194{
195 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
196 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
197 __le32 nfrees;
198
199 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
200 while (n-- > 0) {
201 desc->pg_nfrees = nfrees;
202 desc++;
203 }
204}
205
206static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
207 int create,
208 void (*init_block)(struct inode *,
209 struct buffer_head *,
210 void *),
211 struct buffer_head **bhp,
212 struct nilfs_bh_assoc *prev,
213 spinlock_t *lock)
214{
215 int ret;
216
217 spin_lock(lock);
218 if (prev->bh && blkoff == prev->blkoff) {
219 get_bh(prev->bh);
220 *bhp = prev->bh;
221 spin_unlock(lock);
222 return 0;
223 }
224 spin_unlock(lock);
225
226 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
227 if (!ret) {
228 spin_lock(lock);
229 /*
230 * The following code must be safe for change of the
231 * cache contents during the get block call.
232 */
233 brelse(prev->bh);
234 get_bh(*bhp);
235 prev->bh = *bhp;
236 prev->blkoff = blkoff;
237 spin_unlock(lock);
238 }
239 return ret;
240}
241
242/**
243 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
244 * @inode: inode of metadata file using this allocator
245 * @group: group number
246 * @create: create flag
247 * @bhp: pointer to store the resultant buffer head
248 */
249static int nilfs_palloc_get_desc_block(struct inode *inode,
250 unsigned long group,
251 int create, struct buffer_head **bhp)
252{
253 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
254
255 return nilfs_palloc_get_block(inode,
256 nilfs_palloc_desc_blkoff(inode, group),
257 create, nilfs_palloc_desc_block_init,
258 bhp, &cache->prev_desc, &cache->lock);
259}
260
261/**
262 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
263 * @inode: inode of metadata file using this allocator
264 * @group: group number
265 * @create: create flag
266 * @bhp: pointer to store the resultant buffer head
267 */
268static int nilfs_palloc_get_bitmap_block(struct inode *inode,
269 unsigned long group,
270 int create, struct buffer_head **bhp)
271{
272 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
273
274 return nilfs_palloc_get_block(inode,
275 nilfs_palloc_bitmap_blkoff(inode, group),
276 create, NULL, bhp,
277 &cache->prev_bitmap, &cache->lock);
278}
279
280/**
281 * nilfs_palloc_get_entry_block - get buffer head of an entry block
282 * @inode: inode of metadata file using this allocator
283 * @nr: serial number of the entry (e.g. inode number)
284 * @create: create flag
285 * @bhp: pointer to store the resultant buffer head
286 */
287int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
288 int create, struct buffer_head **bhp)
289{
290 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
291
292 return nilfs_palloc_get_block(inode,
293 nilfs_palloc_entry_blkoff(inode, nr),
294 create, NULL, bhp,
295 &cache->prev_entry, &cache->lock);
296}
297
298/**
299 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
300 * @inode: inode of metadata file using this allocator
301 * @group: group number
302 * @bh: buffer head of the buffer storing the group descriptor block
303 * @kaddr: kernel address mapped for the page including the buffer
304 */
305static struct nilfs_palloc_group_desc *
306nilfs_palloc_block_get_group_desc(const struct inode *inode,
307 unsigned long group,
308 const struct buffer_head *bh, void *kaddr)
309{
310 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
311 group % nilfs_palloc_groups_per_desc_block(inode);
312}
313
314/**
315 * nilfs_palloc_block_get_entry - get kernel address of an entry
316 * @inode: inode of metadata file using this allocator
317 * @nr: serial number of the entry (e.g. inode number)
318 * @bh: buffer head of the buffer storing the entry block
319 * @kaddr: kernel address mapped for the page including the buffer
320 */
321void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
322 const struct buffer_head *bh, void *kaddr)
323{
324 unsigned long entry_offset, group_offset;
325
326 nilfs_palloc_group(inode, nr, &group_offset);
327 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
328
329 return kaddr + bh_offset(bh) +
330 entry_offset * NILFS_MDT(inode)->mi_entry_size;
331}
332
333/**
334 * nilfs_palloc_find_available_slot - find available slot in a group
335 * @inode: inode of metadata file using this allocator
336 * @group: group number
337 * @target: offset number of an entry in the group (start point)
338 * @bitmap: bitmap of the group
339 * @bsize: size in bits
340 */
341static int nilfs_palloc_find_available_slot(struct inode *inode,
342 unsigned long group,
343 unsigned long target,
344 unsigned char *bitmap,
345 int bsize)
346{
347 int curr, pos, end, i;
348
349 if (target > 0) {
350 end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
351 if (end > bsize)
352 end = bsize;
353 pos = nilfs_find_next_zero_bit(bitmap, end, target);
354 if (pos < end &&
355 !nilfs_set_bit_atomic(
356 nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
357 return pos;
358 } else
359 end = 0;
360
361 for (i = 0, curr = end;
362 i < bsize;
363 i += BITS_PER_LONG, curr += BITS_PER_LONG) {
364 /* wrap around */
365 if (curr >= bsize)
366 curr = 0;
367 while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
368 != ~0UL) {
369 end = curr + BITS_PER_LONG;
370 if (end > bsize)
371 end = bsize;
372 pos = nilfs_find_next_zero_bit(bitmap, end, curr);
373 if ((pos < end) &&
374 !nilfs_set_bit_atomic(
375 nilfs_mdt_bgl_lock(inode, group), pos,
376 bitmap))
377 return pos;
378 }
379 }
380 return -ENOSPC;
381}
382
383/**
384 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
385 * in a group descriptor block
386 * @inode: inode of metadata file using this allocator
387 * @curr: current group number
388 * @max: maximum number of groups
389 */
390static unsigned long
391nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
392 unsigned long curr, unsigned long max)
393{
394 return min_t(unsigned long,
395 nilfs_palloc_groups_per_desc_block(inode) -
396 curr % nilfs_palloc_groups_per_desc_block(inode),
397 max - curr + 1);
398}
399
400/**
401 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
402 * @inode: inode of metadata file using this allocator
403 * @req: nilfs_palloc_req structure exchanged for the allocation
404 */
405int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
406 struct nilfs_palloc_req *req)
407{
408 struct buffer_head *desc_bh, *bitmap_bh;
409 struct nilfs_palloc_group_desc *desc;
410 unsigned char *bitmap;
411 void *desc_kaddr, *bitmap_kaddr;
412 unsigned long group, maxgroup, ngroups;
413 unsigned long group_offset, maxgroup_offset;
414 unsigned long n, entries_per_group, groups_per_desc_block;
415 unsigned long i, j;
416 int pos, ret;
417
418 ngroups = nilfs_palloc_groups_count(inode);
419 maxgroup = ngroups - 1;
420 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
421 entries_per_group = nilfs_palloc_entries_per_group(inode);
422 groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
423
424 for (i = 0; i < ngroups; i += n) {
425 if (group >= ngroups) {
426 /* wrap around */
427 group = 0;
428 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
429 &maxgroup_offset) - 1;
430 }
431 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
432 if (ret < 0)
433 return ret;
434 desc_kaddr = kmap(desc_bh->b_page);
435 desc = nilfs_palloc_block_get_group_desc(
436 inode, group, desc_bh, desc_kaddr);
437 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
438 maxgroup);
439 for (j = 0; j < n; j++, desc++, group++) {
440 if (nilfs_palloc_group_desc_nfrees(inode, group, desc)
441 > 0) {
442 ret = nilfs_palloc_get_bitmap_block(
443 inode, group, 1, &bitmap_bh);
444 if (ret < 0)
445 goto out_desc;
446 bitmap_kaddr = kmap(bitmap_bh->b_page);
447 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
448 pos = nilfs_palloc_find_available_slot(
449 inode, group, group_offset, bitmap,
450 entries_per_group);
451 if (pos >= 0) {
452 /* found a free entry */
453 nilfs_palloc_group_desc_add_entries(
454 inode, group, desc, -1);
455 req->pr_entry_nr =
456 entries_per_group * group + pos;
457 kunmap(desc_bh->b_page);
458 kunmap(bitmap_bh->b_page);
459
460 req->pr_desc_bh = desc_bh;
461 req->pr_bitmap_bh = bitmap_bh;
462 return 0;
463 }
464 kunmap(bitmap_bh->b_page);
465 brelse(bitmap_bh);
466 }
467
468 group_offset = 0;
469 }
470
471 kunmap(desc_bh->b_page);
472 brelse(desc_bh);
473 }
474
475 /* no entries left */
476 return -ENOSPC;
477
478 out_desc:
479 kunmap(desc_bh->b_page);
480 brelse(desc_bh);
481 return ret;
482}
483
484/**
485 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
486 * @inode: inode of metadata file using this allocator
487 * @req: nilfs_palloc_req structure exchanged for the allocation
488 */
489void nilfs_palloc_commit_alloc_entry(struct inode *inode,
490 struct nilfs_palloc_req *req)
491{
492 mark_buffer_dirty(req->pr_bitmap_bh);
493 mark_buffer_dirty(req->pr_desc_bh);
494 nilfs_mdt_mark_dirty(inode);
495
496 brelse(req->pr_bitmap_bh);
497 brelse(req->pr_desc_bh);
498}
499
500/**
501 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
502 * @inode: inode of metadata file using this allocator
503 * @req: nilfs_palloc_req structure exchanged for the removal
504 */
505void nilfs_palloc_commit_free_entry(struct inode *inode,
506 struct nilfs_palloc_req *req)
507{
508 struct nilfs_palloc_group_desc *desc;
509 unsigned long group, group_offset;
510 unsigned char *bitmap;
511 void *desc_kaddr, *bitmap_kaddr;
512
513 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
514 desc_kaddr = kmap(req->pr_desc_bh->b_page);
515 desc = nilfs_palloc_block_get_group_desc(inode, group,
516 req->pr_desc_bh, desc_kaddr);
517 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
518 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
519
520 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
521 group_offset, bitmap))
522 printk(KERN_WARNING "%s: entry number %llu already freed\n",
523 __func__, (unsigned long long)req->pr_entry_nr);
524 else
525 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
526
527 kunmap(req->pr_bitmap_bh->b_page);
528 kunmap(req->pr_desc_bh->b_page);
529
530 mark_buffer_dirty(req->pr_desc_bh);
531 mark_buffer_dirty(req->pr_bitmap_bh);
532 nilfs_mdt_mark_dirty(inode);
533
534 brelse(req->pr_bitmap_bh);
535 brelse(req->pr_desc_bh);
536}
537
538/**
539 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
540 * @inode: inode of metadata file using this allocator
541 * @req: nilfs_palloc_req structure exchanged for the allocation
542 */
543void nilfs_palloc_abort_alloc_entry(struct inode *inode,
544 struct nilfs_palloc_req *req)
545{
546 struct nilfs_palloc_group_desc *desc;
547 void *desc_kaddr, *bitmap_kaddr;
548 unsigned char *bitmap;
549 unsigned long group, group_offset;
550
551 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
552 desc_kaddr = kmap(req->pr_desc_bh->b_page);
553 desc = nilfs_palloc_block_get_group_desc(inode, group,
554 req->pr_desc_bh, desc_kaddr);
555 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
556 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
557 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
558 group_offset, bitmap))
559 printk(KERN_WARNING "%s: entry number %llu already freed\n",
560 __func__, (unsigned long long)req->pr_entry_nr);
561 else
562 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
563
564 kunmap(req->pr_bitmap_bh->b_page);
565 kunmap(req->pr_desc_bh->b_page);
566
567 brelse(req->pr_bitmap_bh);
568 brelse(req->pr_desc_bh);
569
570 req->pr_entry_nr = 0;
571 req->pr_bitmap_bh = NULL;
572 req->pr_desc_bh = NULL;
573}
574
575/**
576 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
577 * @inode: inode of metadata file using this allocator
578 * @req: nilfs_palloc_req structure exchanged for the removal
579 */
580int nilfs_palloc_prepare_free_entry(struct inode *inode,
581 struct nilfs_palloc_req *req)
582{
583 struct buffer_head *desc_bh, *bitmap_bh;
584 unsigned long group, group_offset;
585 int ret;
586
587 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
588 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
589 if (ret < 0)
590 return ret;
591 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
592 if (ret < 0) {
593 brelse(desc_bh);
594 return ret;
595 }
596
597 req->pr_desc_bh = desc_bh;
598 req->pr_bitmap_bh = bitmap_bh;
599 return 0;
600}
601
602/**
603 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
604 * @inode: inode of metadata file using this allocator
605 * @req: nilfs_palloc_req structure exchanged for the removal
606 */
607void nilfs_palloc_abort_free_entry(struct inode *inode,
608 struct nilfs_palloc_req *req)
609{
610 brelse(req->pr_bitmap_bh);
611 brelse(req->pr_desc_bh);
612
613 req->pr_entry_nr = 0;
614 req->pr_bitmap_bh = NULL;
615 req->pr_desc_bh = NULL;
616}
617
618/**
619 * nilfs_palloc_group_is_in - judge if an entry is in a group
620 * @inode: inode of metadata file using this allocator
621 * @group: group number
622 * @nr: serial number of the entry (e.g. inode number)
623 */
624static int
625nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
626{
627 __u64 first, last;
628
629 first = group * nilfs_palloc_entries_per_group(inode);
630 last = first + nilfs_palloc_entries_per_group(inode) - 1;
631 return (nr >= first) && (nr <= last);
632}
633
634/**
635 * nilfs_palloc_freev - deallocate a set of persistent objects
636 * @inode: inode of metadata file using this allocator
637 * @entry_nrs: array of entry numbers to be deallocated
638 * @nitems: number of entries stored in @entry_nrs
639 */
640int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
641{
642 struct buffer_head *desc_bh, *bitmap_bh;
643 struct nilfs_palloc_group_desc *desc;
644 unsigned char *bitmap;
645 void *desc_kaddr, *bitmap_kaddr;
646 unsigned long group, group_offset;
647 int i, j, n, ret;
648
649 for (i = 0; i < nitems; i = j) {
650 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
651 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
652 if (ret < 0)
653 return ret;
654 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
655 &bitmap_bh);
656 if (ret < 0) {
657 brelse(desc_bh);
658 return ret;
659 }
660 desc_kaddr = kmap(desc_bh->b_page);
661 desc = nilfs_palloc_block_get_group_desc(
662 inode, group, desc_bh, desc_kaddr);
663 bitmap_kaddr = kmap(bitmap_bh->b_page);
664 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
665 for (j = i, n = 0;
666 (j < nitems) && nilfs_palloc_group_is_in(inode, group,
667 entry_nrs[j]);
668 j++) {
669 nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
670 if (!nilfs_clear_bit_atomic(
671 nilfs_mdt_bgl_lock(inode, group),
672 group_offset, bitmap)) {
673 printk(KERN_WARNING
674 "%s: entry number %llu already freed\n",
675 __func__,
676 (unsigned long long)entry_nrs[j]);
677 } else {
678 n++;
679 }
680 }
681 nilfs_palloc_group_desc_add_entries(inode, group, desc, n);
682
683 kunmap(bitmap_bh->b_page);
684 kunmap(desc_bh->b_page);
685
686 mark_buffer_dirty(desc_bh);
687 mark_buffer_dirty(bitmap_bh);
688 nilfs_mdt_mark_dirty(inode);
689
690 brelse(bitmap_bh);
691 brelse(desc_bh);
692 }
693 return 0;
694}
695
696void nilfs_palloc_setup_cache(struct inode *inode,
697 struct nilfs_palloc_cache *cache)
698{
699 NILFS_MDT(inode)->mi_palloc_cache = cache;
700 spin_lock_init(&cache->lock);
701}
702
703void nilfs_palloc_clear_cache(struct inode *inode)
704{
705 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
706
707 spin_lock(&cache->lock);
708 brelse(cache->prev_desc.bh);
709 brelse(cache->prev_bitmap.bh);
710 brelse(cache->prev_entry.bh);
711 cache->prev_desc.bh = NULL;
712 cache->prev_bitmap.bh = NULL;
713 cache->prev_entry.bh = NULL;
714 spin_unlock(&cache->lock);
715}
716
717void nilfs_palloc_destroy_cache(struct inode *inode)
718{
719 nilfs_palloc_clear_cache(inode);
720 NILFS_MDT(inode)->mi_palloc_cache = NULL;
721}
1/*
2 * alloc.c - NILFS dat/inode allocator
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 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
23 */
24
25#include <linux/types.h>
26#include <linux/buffer_head.h>
27#include <linux/fs.h>
28#include <linux/bitops.h>
29#include <linux/slab.h>
30#include "mdt.h"
31#include "alloc.h"
32
33
34/**
35 * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
36 * descriptor block can maintain
37 * @inode: inode of metadata file using this allocator
38 */
39static inline unsigned long
40nilfs_palloc_groups_per_desc_block(const struct inode *inode)
41{
42 return (1UL << inode->i_blkbits) /
43 sizeof(struct nilfs_palloc_group_desc);
44}
45
46/**
47 * nilfs_palloc_groups_count - get maximum number of groups
48 * @inode: inode of metadata file using this allocator
49 */
50static inline unsigned long
51nilfs_palloc_groups_count(const struct inode *inode)
52{
53 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
54}
55
56/**
57 * nilfs_palloc_init_blockgroup - initialize private variables for allocator
58 * @inode: inode of metadata file using this allocator
59 * @entry_size: size of the persistent object
60 */
61int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
62{
63 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
64
65 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
66 if (!mi->mi_bgl)
67 return -ENOMEM;
68
69 bgl_lock_init(mi->mi_bgl);
70
71 nilfs_mdt_set_entry_size(inode, entry_size, 0);
72
73 mi->mi_blocks_per_group =
74 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
75 mi->mi_entries_per_block) + 1;
76 /* Number of blocks in a group including entry blocks and
77 a bitmap block */
78 mi->mi_blocks_per_desc_block =
79 nilfs_palloc_groups_per_desc_block(inode) *
80 mi->mi_blocks_per_group + 1;
81 /* Number of blocks per descriptor including the
82 descriptor block */
83 return 0;
84}
85
86/**
87 * nilfs_palloc_group - get group number and offset from an entry number
88 * @inode: inode of metadata file using this allocator
89 * @nr: serial number of the entry (e.g. inode number)
90 * @offset: pointer to store offset number in the group
91 */
92static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
93 unsigned long *offset)
94{
95 __u64 group = nr;
96
97 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
98 return group;
99}
100
101/**
102 * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
103 * @inode: inode of metadata file using this allocator
104 * @group: group number
105 *
106 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
107 * block which contains a descriptor of the specified group.
108 */
109static unsigned long
110nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
111{
112 unsigned long desc_block =
113 group / nilfs_palloc_groups_per_desc_block(inode);
114 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
115}
116
117/**
118 * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
119 * @inode: inode of metadata file using this allocator
120 * @group: group number
121 *
122 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
123 * block used to allocate/deallocate entries in the specified group.
124 */
125static unsigned long
126nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
127{
128 unsigned long desc_offset =
129 group % nilfs_palloc_groups_per_desc_block(inode);
130 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
131 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
132}
133
134/**
135 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
136 * @inode: inode of metadata file using this allocator
137 * @group: group number
138 * @desc: pointer to descriptor structure for the group
139 */
140static unsigned long
141nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,
142 const struct nilfs_palloc_group_desc *desc)
143{
144 unsigned long nfree;
145
146 spin_lock(nilfs_mdt_bgl_lock(inode, group));
147 nfree = le32_to_cpu(desc->pg_nfrees);
148 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
149 return nfree;
150}
151
152/**
153 * nilfs_palloc_group_desc_add_entries - adjust count of free entries
154 * @inode: inode of metadata file using this allocator
155 * @group: group number
156 * @desc: pointer to descriptor structure for the group
157 * @n: delta to be added
158 */
159static void
160nilfs_palloc_group_desc_add_entries(struct inode *inode,
161 unsigned long group,
162 struct nilfs_palloc_group_desc *desc,
163 u32 n)
164{
165 spin_lock(nilfs_mdt_bgl_lock(inode, group));
166 le32_add_cpu(&desc->pg_nfrees, n);
167 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
168}
169
170/**
171 * nilfs_palloc_entry_blkoff - get block offset of an entry block
172 * @inode: inode of metadata file using this allocator
173 * @nr: serial number of the entry (e.g. inode number)
174 */
175static unsigned long
176nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
177{
178 unsigned long group, group_offset;
179
180 group = nilfs_palloc_group(inode, nr, &group_offset);
181
182 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
183 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
184}
185
186/**
187 * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
188 * @inode: inode of metadata file
189 * @bh: buffer head of the buffer to be initialized
190 * @kaddr: kernel address mapped for the page including the buffer
191 */
192static void nilfs_palloc_desc_block_init(struct inode *inode,
193 struct buffer_head *bh, void *kaddr)
194{
195 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
196 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
197 __le32 nfrees;
198
199 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
200 while (n-- > 0) {
201 desc->pg_nfrees = nfrees;
202 desc++;
203 }
204}
205
206static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
207 int create,
208 void (*init_block)(struct inode *,
209 struct buffer_head *,
210 void *),
211 struct buffer_head **bhp,
212 struct nilfs_bh_assoc *prev,
213 spinlock_t *lock)
214{
215 int ret;
216
217 spin_lock(lock);
218 if (prev->bh && blkoff == prev->blkoff) {
219 get_bh(prev->bh);
220 *bhp = prev->bh;
221 spin_unlock(lock);
222 return 0;
223 }
224 spin_unlock(lock);
225
226 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
227 if (!ret) {
228 spin_lock(lock);
229 /*
230 * The following code must be safe for change of the
231 * cache contents during the get block call.
232 */
233 brelse(prev->bh);
234 get_bh(*bhp);
235 prev->bh = *bhp;
236 prev->blkoff = blkoff;
237 spin_unlock(lock);
238 }
239 return ret;
240}
241
242/**
243 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
244 * @inode: inode of metadata file using this allocator
245 * @group: group number
246 * @create: create flag
247 * @bhp: pointer to store the resultant buffer head
248 */
249static int nilfs_palloc_get_desc_block(struct inode *inode,
250 unsigned long group,
251 int create, struct buffer_head **bhp)
252{
253 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
254
255 return nilfs_palloc_get_block(inode,
256 nilfs_palloc_desc_blkoff(inode, group),
257 create, nilfs_palloc_desc_block_init,
258 bhp, &cache->prev_desc, &cache->lock);
259}
260
261/**
262 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
263 * @inode: inode of metadata file using this allocator
264 * @group: group number
265 * @create: create flag
266 * @bhp: pointer to store the resultant buffer head
267 */
268static int nilfs_palloc_get_bitmap_block(struct inode *inode,
269 unsigned long group,
270 int create, struct buffer_head **bhp)
271{
272 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
273
274 return nilfs_palloc_get_block(inode,
275 nilfs_palloc_bitmap_blkoff(inode, group),
276 create, NULL, bhp,
277 &cache->prev_bitmap, &cache->lock);
278}
279
280/**
281 * nilfs_palloc_get_entry_block - get buffer head of an entry block
282 * @inode: inode of metadata file using this allocator
283 * @nr: serial number of the entry (e.g. inode number)
284 * @create: create flag
285 * @bhp: pointer to store the resultant buffer head
286 */
287int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
288 int create, struct buffer_head **bhp)
289{
290 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
291
292 return nilfs_palloc_get_block(inode,
293 nilfs_palloc_entry_blkoff(inode, nr),
294 create, NULL, bhp,
295 &cache->prev_entry, &cache->lock);
296}
297
298/**
299 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
300 * @inode: inode of metadata file using this allocator
301 * @group: group number
302 * @bh: buffer head of the buffer storing the group descriptor block
303 * @kaddr: kernel address mapped for the page including the buffer
304 */
305static struct nilfs_palloc_group_desc *
306nilfs_palloc_block_get_group_desc(const struct inode *inode,
307 unsigned long group,
308 const struct buffer_head *bh, void *kaddr)
309{
310 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
311 group % nilfs_palloc_groups_per_desc_block(inode);
312}
313
314/**
315 * nilfs_palloc_block_get_entry - get kernel address of an entry
316 * @inode: inode of metadata file using this allocator
317 * @nr: serial number of the entry (e.g. inode number)
318 * @bh: buffer head of the buffer storing the entry block
319 * @kaddr: kernel address mapped for the page including the buffer
320 */
321void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
322 const struct buffer_head *bh, void *kaddr)
323{
324 unsigned long entry_offset, group_offset;
325
326 nilfs_palloc_group(inode, nr, &group_offset);
327 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
328
329 return kaddr + bh_offset(bh) +
330 entry_offset * NILFS_MDT(inode)->mi_entry_size;
331}
332
333/**
334 * nilfs_palloc_find_available_slot - find available slot in a group
335 * @inode: inode of metadata file using this allocator
336 * @group: group number
337 * @target: offset number of an entry in the group (start point)
338 * @bitmap: bitmap of the group
339 * @bsize: size in bits
340 */
341static int nilfs_palloc_find_available_slot(struct inode *inode,
342 unsigned long group,
343 unsigned long target,
344 unsigned char *bitmap,
345 int bsize)
346{
347 int curr, pos, end, i;
348
349 if (target > 0) {
350 end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
351 if (end > bsize)
352 end = bsize;
353 pos = nilfs_find_next_zero_bit(bitmap, end, target);
354 if (pos < end &&
355 !nilfs_set_bit_atomic(
356 nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
357 return pos;
358 } else
359 end = 0;
360
361 for (i = 0, curr = end;
362 i < bsize;
363 i += BITS_PER_LONG, curr += BITS_PER_LONG) {
364 /* wrap around */
365 if (curr >= bsize)
366 curr = 0;
367 while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
368 != ~0UL) {
369 end = curr + BITS_PER_LONG;
370 if (end > bsize)
371 end = bsize;
372 pos = nilfs_find_next_zero_bit(bitmap, end, curr);
373 if ((pos < end) &&
374 !nilfs_set_bit_atomic(
375 nilfs_mdt_bgl_lock(inode, group), pos,
376 bitmap))
377 return pos;
378 }
379 }
380 return -ENOSPC;
381}
382
383/**
384 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
385 * in a group descriptor block
386 * @inode: inode of metadata file using this allocator
387 * @curr: current group number
388 * @max: maximum number of groups
389 */
390static unsigned long
391nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
392 unsigned long curr, unsigned long max)
393{
394 return min_t(unsigned long,
395 nilfs_palloc_groups_per_desc_block(inode) -
396 curr % nilfs_palloc_groups_per_desc_block(inode),
397 max - curr + 1);
398}
399
400/**
401 * nilfs_palloc_count_desc_blocks - count descriptor blocks number
402 * @inode: inode of metadata file using this allocator
403 * @desc_blocks: descriptor blocks number [out]
404 */
405static int nilfs_palloc_count_desc_blocks(struct inode *inode,
406 unsigned long *desc_blocks)
407{
408 unsigned long blknum;
409 int ret;
410
411 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
412 if (likely(!ret))
413 *desc_blocks = DIV_ROUND_UP(
414 blknum, NILFS_MDT(inode)->mi_blocks_per_desc_block);
415 return ret;
416}
417
418/**
419 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
420 * MDT file growing
421 * @inode: inode of metadata file using this allocator
422 * @desc_blocks: known current descriptor blocks count
423 */
424static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
425 unsigned long desc_blocks)
426{
427 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
428 nilfs_palloc_groups_count(inode);
429}
430
431/**
432 * nilfs_palloc_count_max_entries - count max number of entries that can be
433 * described by descriptor blocks count
434 * @inode: inode of metadata file using this allocator
435 * @nused: current number of used entries
436 * @nmaxp: max number of entries [out]
437 */
438int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
439{
440 unsigned long desc_blocks = 0;
441 u64 entries_per_desc_block, nmax;
442 int err;
443
444 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
445 if (unlikely(err))
446 return err;
447
448 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
449 nilfs_palloc_groups_per_desc_block(inode);
450 nmax = entries_per_desc_block * desc_blocks;
451
452 if (nused == nmax &&
453 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
454 nmax += entries_per_desc_block;
455
456 if (nused > nmax)
457 return -ERANGE;
458
459 *nmaxp = nmax;
460 return 0;
461}
462
463/**
464 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
465 * @inode: inode of metadata file using this allocator
466 * @req: nilfs_palloc_req structure exchanged for the allocation
467 */
468int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
469 struct nilfs_palloc_req *req)
470{
471 struct buffer_head *desc_bh, *bitmap_bh;
472 struct nilfs_palloc_group_desc *desc;
473 unsigned char *bitmap;
474 void *desc_kaddr, *bitmap_kaddr;
475 unsigned long group, maxgroup, ngroups;
476 unsigned long group_offset, maxgroup_offset;
477 unsigned long n, entries_per_group, groups_per_desc_block;
478 unsigned long i, j;
479 int pos, ret;
480
481 ngroups = nilfs_palloc_groups_count(inode);
482 maxgroup = ngroups - 1;
483 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
484 entries_per_group = nilfs_palloc_entries_per_group(inode);
485 groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
486
487 for (i = 0; i < ngroups; i += n) {
488 if (group >= ngroups) {
489 /* wrap around */
490 group = 0;
491 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
492 &maxgroup_offset) - 1;
493 }
494 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
495 if (ret < 0)
496 return ret;
497 desc_kaddr = kmap(desc_bh->b_page);
498 desc = nilfs_palloc_block_get_group_desc(
499 inode, group, desc_bh, desc_kaddr);
500 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
501 maxgroup);
502 for (j = 0; j < n; j++, desc++, group++) {
503 if (nilfs_palloc_group_desc_nfrees(inode, group, desc)
504 > 0) {
505 ret = nilfs_palloc_get_bitmap_block(
506 inode, group, 1, &bitmap_bh);
507 if (ret < 0)
508 goto out_desc;
509 bitmap_kaddr = kmap(bitmap_bh->b_page);
510 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
511 pos = nilfs_palloc_find_available_slot(
512 inode, group, group_offset, bitmap,
513 entries_per_group);
514 if (pos >= 0) {
515 /* found a free entry */
516 nilfs_palloc_group_desc_add_entries(
517 inode, group, desc, -1);
518 req->pr_entry_nr =
519 entries_per_group * group + pos;
520 kunmap(desc_bh->b_page);
521 kunmap(bitmap_bh->b_page);
522
523 req->pr_desc_bh = desc_bh;
524 req->pr_bitmap_bh = bitmap_bh;
525 return 0;
526 }
527 kunmap(bitmap_bh->b_page);
528 brelse(bitmap_bh);
529 }
530
531 group_offset = 0;
532 }
533
534 kunmap(desc_bh->b_page);
535 brelse(desc_bh);
536 }
537
538 /* no entries left */
539 return -ENOSPC;
540
541 out_desc:
542 kunmap(desc_bh->b_page);
543 brelse(desc_bh);
544 return ret;
545}
546
547/**
548 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
549 * @inode: inode of metadata file using this allocator
550 * @req: nilfs_palloc_req structure exchanged for the allocation
551 */
552void nilfs_palloc_commit_alloc_entry(struct inode *inode,
553 struct nilfs_palloc_req *req)
554{
555 mark_buffer_dirty(req->pr_bitmap_bh);
556 mark_buffer_dirty(req->pr_desc_bh);
557 nilfs_mdt_mark_dirty(inode);
558
559 brelse(req->pr_bitmap_bh);
560 brelse(req->pr_desc_bh);
561}
562
563/**
564 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
565 * @inode: inode of metadata file using this allocator
566 * @req: nilfs_palloc_req structure exchanged for the removal
567 */
568void nilfs_palloc_commit_free_entry(struct inode *inode,
569 struct nilfs_palloc_req *req)
570{
571 struct nilfs_palloc_group_desc *desc;
572 unsigned long group, group_offset;
573 unsigned char *bitmap;
574 void *desc_kaddr, *bitmap_kaddr;
575
576 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
577 desc_kaddr = kmap(req->pr_desc_bh->b_page);
578 desc = nilfs_palloc_block_get_group_desc(inode, group,
579 req->pr_desc_bh, desc_kaddr);
580 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
581 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
582
583 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
584 group_offset, bitmap))
585 printk(KERN_WARNING "%s: entry number %llu already freed\n",
586 __func__, (unsigned long long)req->pr_entry_nr);
587 else
588 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
589
590 kunmap(req->pr_bitmap_bh->b_page);
591 kunmap(req->pr_desc_bh->b_page);
592
593 mark_buffer_dirty(req->pr_desc_bh);
594 mark_buffer_dirty(req->pr_bitmap_bh);
595 nilfs_mdt_mark_dirty(inode);
596
597 brelse(req->pr_bitmap_bh);
598 brelse(req->pr_desc_bh);
599}
600
601/**
602 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
603 * @inode: inode of metadata file using this allocator
604 * @req: nilfs_palloc_req structure exchanged for the allocation
605 */
606void nilfs_palloc_abort_alloc_entry(struct inode *inode,
607 struct nilfs_palloc_req *req)
608{
609 struct nilfs_palloc_group_desc *desc;
610 void *desc_kaddr, *bitmap_kaddr;
611 unsigned char *bitmap;
612 unsigned long group, group_offset;
613
614 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
615 desc_kaddr = kmap(req->pr_desc_bh->b_page);
616 desc = nilfs_palloc_block_get_group_desc(inode, group,
617 req->pr_desc_bh, desc_kaddr);
618 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
619 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
620 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
621 group_offset, bitmap))
622 printk(KERN_WARNING "%s: entry number %llu already freed\n",
623 __func__, (unsigned long long)req->pr_entry_nr);
624 else
625 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
626
627 kunmap(req->pr_bitmap_bh->b_page);
628 kunmap(req->pr_desc_bh->b_page);
629
630 brelse(req->pr_bitmap_bh);
631 brelse(req->pr_desc_bh);
632
633 req->pr_entry_nr = 0;
634 req->pr_bitmap_bh = NULL;
635 req->pr_desc_bh = NULL;
636}
637
638/**
639 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
640 * @inode: inode of metadata file using this allocator
641 * @req: nilfs_palloc_req structure exchanged for the removal
642 */
643int nilfs_palloc_prepare_free_entry(struct inode *inode,
644 struct nilfs_palloc_req *req)
645{
646 struct buffer_head *desc_bh, *bitmap_bh;
647 unsigned long group, group_offset;
648 int ret;
649
650 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
651 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
652 if (ret < 0)
653 return ret;
654 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
655 if (ret < 0) {
656 brelse(desc_bh);
657 return ret;
658 }
659
660 req->pr_desc_bh = desc_bh;
661 req->pr_bitmap_bh = bitmap_bh;
662 return 0;
663}
664
665/**
666 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
667 * @inode: inode of metadata file using this allocator
668 * @req: nilfs_palloc_req structure exchanged for the removal
669 */
670void nilfs_palloc_abort_free_entry(struct inode *inode,
671 struct nilfs_palloc_req *req)
672{
673 brelse(req->pr_bitmap_bh);
674 brelse(req->pr_desc_bh);
675
676 req->pr_entry_nr = 0;
677 req->pr_bitmap_bh = NULL;
678 req->pr_desc_bh = NULL;
679}
680
681/**
682 * nilfs_palloc_group_is_in - judge if an entry is in a group
683 * @inode: inode of metadata file using this allocator
684 * @group: group number
685 * @nr: serial number of the entry (e.g. inode number)
686 */
687static int
688nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
689{
690 __u64 first, last;
691
692 first = group * nilfs_palloc_entries_per_group(inode);
693 last = first + nilfs_palloc_entries_per_group(inode) - 1;
694 return (nr >= first) && (nr <= last);
695}
696
697/**
698 * nilfs_palloc_freev - deallocate a set of persistent objects
699 * @inode: inode of metadata file using this allocator
700 * @entry_nrs: array of entry numbers to be deallocated
701 * @nitems: number of entries stored in @entry_nrs
702 */
703int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
704{
705 struct buffer_head *desc_bh, *bitmap_bh;
706 struct nilfs_palloc_group_desc *desc;
707 unsigned char *bitmap;
708 void *desc_kaddr, *bitmap_kaddr;
709 unsigned long group, group_offset;
710 int i, j, n, ret;
711
712 for (i = 0; i < nitems; i = j) {
713 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
714 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
715 if (ret < 0)
716 return ret;
717 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
718 &bitmap_bh);
719 if (ret < 0) {
720 brelse(desc_bh);
721 return ret;
722 }
723 desc_kaddr = kmap(desc_bh->b_page);
724 desc = nilfs_palloc_block_get_group_desc(
725 inode, group, desc_bh, desc_kaddr);
726 bitmap_kaddr = kmap(bitmap_bh->b_page);
727 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
728 for (j = i, n = 0;
729 (j < nitems) && nilfs_palloc_group_is_in(inode, group,
730 entry_nrs[j]);
731 j++) {
732 nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
733 if (!nilfs_clear_bit_atomic(
734 nilfs_mdt_bgl_lock(inode, group),
735 group_offset, bitmap)) {
736 printk(KERN_WARNING
737 "%s: entry number %llu already freed\n",
738 __func__,
739 (unsigned long long)entry_nrs[j]);
740 } else {
741 n++;
742 }
743 }
744 nilfs_palloc_group_desc_add_entries(inode, group, desc, n);
745
746 kunmap(bitmap_bh->b_page);
747 kunmap(desc_bh->b_page);
748
749 mark_buffer_dirty(desc_bh);
750 mark_buffer_dirty(bitmap_bh);
751 nilfs_mdt_mark_dirty(inode);
752
753 brelse(bitmap_bh);
754 brelse(desc_bh);
755 }
756 return 0;
757}
758
759void nilfs_palloc_setup_cache(struct inode *inode,
760 struct nilfs_palloc_cache *cache)
761{
762 NILFS_MDT(inode)->mi_palloc_cache = cache;
763 spin_lock_init(&cache->lock);
764}
765
766void nilfs_palloc_clear_cache(struct inode *inode)
767{
768 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
769
770 spin_lock(&cache->lock);
771 brelse(cache->prev_desc.bh);
772 brelse(cache->prev_bitmap.bh);
773 brelse(cache->prev_entry.bh);
774 cache->prev_desc.bh = NULL;
775 cache->prev_bitmap.bh = NULL;
776 cache->prev_entry.bh = NULL;
777 spin_unlock(&cache->lock);
778}
779
780void nilfs_palloc_destroy_cache(struct inode *inode)
781{
782 nilfs_palloc_clear_cache(inode);
783 NILFS_MDT(inode)->mi_palloc_cache = NULL;
784}