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1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * NILFS dat/inode allocator
4 *
5 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
6 *
7 * Originally written by Koji Sato.
8 * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
9 */
10
11#include <linux/types.h>
12#include <linux/buffer_head.h>
13#include <linux/fs.h>
14#include <linux/bitops.h>
15#include <linux/slab.h>
16#include "mdt.h"
17#include "alloc.h"
18
19
20/**
21 * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
22 * descriptor block can maintain
23 * @inode: inode of metadata file using this allocator
24 */
25static inline unsigned long
26nilfs_palloc_groups_per_desc_block(const struct inode *inode)
27{
28 return i_blocksize(inode) /
29 sizeof(struct nilfs_palloc_group_desc);
30}
31
32/**
33 * nilfs_palloc_groups_count - get maximum number of groups
34 * @inode: inode of metadata file using this allocator
35 */
36static inline unsigned long
37nilfs_palloc_groups_count(const struct inode *inode)
38{
39 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
40}
41
42/**
43 * nilfs_palloc_init_blockgroup - initialize private variables for allocator
44 * @inode: inode of metadata file using this allocator
45 * @entry_size: size of the persistent object
46 */
47int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
48{
49 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
50
51 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
52 if (!mi->mi_bgl)
53 return -ENOMEM;
54
55 bgl_lock_init(mi->mi_bgl);
56
57 nilfs_mdt_set_entry_size(inode, entry_size, 0);
58
59 mi->mi_blocks_per_group =
60 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
61 mi->mi_entries_per_block) + 1;
62 /*
63 * Number of blocks in a group including entry blocks
64 * and a bitmap block
65 */
66 mi->mi_blocks_per_desc_block =
67 nilfs_palloc_groups_per_desc_block(inode) *
68 mi->mi_blocks_per_group + 1;
69 /*
70 * Number of blocks per descriptor including the
71 * descriptor block
72 */
73 return 0;
74}
75
76/**
77 * nilfs_palloc_group - get group number and offset from an entry number
78 * @inode: inode of metadata file using this allocator
79 * @nr: serial number of the entry (e.g. inode number)
80 * @offset: pointer to store offset number in the group
81 */
82static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
83 unsigned long *offset)
84{
85 __u64 group = nr;
86
87 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
88 return group;
89}
90
91/**
92 * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
93 * @inode: inode of metadata file using this allocator
94 * @group: group number
95 *
96 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
97 * block which contains a descriptor of the specified group.
98 */
99static unsigned long
100nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
101{
102 unsigned long desc_block =
103 group / nilfs_palloc_groups_per_desc_block(inode);
104 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
105}
106
107/**
108 * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
109 * @inode: inode of metadata file using this allocator
110 * @group: group number
111 *
112 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
113 * block used to allocate/deallocate entries in the specified group.
114 */
115static unsigned long
116nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
117{
118 unsigned long desc_offset =
119 group % nilfs_palloc_groups_per_desc_block(inode);
120 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
121 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
122}
123
124/**
125 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
126 * @desc: pointer to descriptor structure for the group
127 * @lock: spin lock protecting @desc
128 */
129static unsigned long
130nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
131 spinlock_t *lock)
132{
133 unsigned long nfree;
134
135 spin_lock(lock);
136 nfree = le32_to_cpu(desc->pg_nfrees);
137 spin_unlock(lock);
138 return nfree;
139}
140
141/**
142 * nilfs_palloc_group_desc_add_entries - adjust count of free entries
143 * @desc: pointer to descriptor structure for the group
144 * @lock: spin lock protecting @desc
145 * @n: delta to be added
146 */
147static u32
148nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
149 spinlock_t *lock, u32 n)
150{
151 u32 nfree;
152
153 spin_lock(lock);
154 le32_add_cpu(&desc->pg_nfrees, n);
155 nfree = le32_to_cpu(desc->pg_nfrees);
156 spin_unlock(lock);
157 return nfree;
158}
159
160/**
161 * nilfs_palloc_entry_blkoff - get block offset of an entry block
162 * @inode: inode of metadata file using this allocator
163 * @nr: serial number of the entry (e.g. inode number)
164 */
165static unsigned long
166nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
167{
168 unsigned long group, group_offset;
169
170 group = nilfs_palloc_group(inode, nr, &group_offset);
171
172 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
173 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
174}
175
176/**
177 * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
178 * @inode: inode of metadata file
179 * @bh: buffer head of the buffer to be initialized
180 * @kaddr: kernel address mapped for the page including the buffer
181 */
182static void nilfs_palloc_desc_block_init(struct inode *inode,
183 struct buffer_head *bh, void *kaddr)
184{
185 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
186 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
187 __le32 nfrees;
188
189 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
190 while (n-- > 0) {
191 desc->pg_nfrees = nfrees;
192 desc++;
193 }
194}
195
196static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
197 int create,
198 void (*init_block)(struct inode *,
199 struct buffer_head *,
200 void *),
201 struct buffer_head **bhp,
202 struct nilfs_bh_assoc *prev,
203 spinlock_t *lock)
204{
205 int ret;
206
207 spin_lock(lock);
208 if (prev->bh && blkoff == prev->blkoff &&
209 likely(buffer_uptodate(prev->bh))) {
210 get_bh(prev->bh);
211 *bhp = prev->bh;
212 spin_unlock(lock);
213 return 0;
214 }
215 spin_unlock(lock);
216
217 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
218 if (!ret) {
219 spin_lock(lock);
220 /*
221 * The following code must be safe for change of the
222 * cache contents during the get block call.
223 */
224 brelse(prev->bh);
225 get_bh(*bhp);
226 prev->bh = *bhp;
227 prev->blkoff = blkoff;
228 spin_unlock(lock);
229 }
230 return ret;
231}
232
233/**
234 * nilfs_palloc_delete_block - delete a block on the persistent allocator file
235 * @inode: inode of metadata file using this allocator
236 * @blkoff: block offset
237 * @prev: nilfs_bh_assoc struct of the last used buffer
238 * @lock: spin lock protecting @prev
239 */
240static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
241 struct nilfs_bh_assoc *prev,
242 spinlock_t *lock)
243{
244 spin_lock(lock);
245 if (prev->bh && blkoff == prev->blkoff) {
246 brelse(prev->bh);
247 prev->bh = NULL;
248 }
249 spin_unlock(lock);
250 return nilfs_mdt_delete_block(inode, blkoff);
251}
252
253/**
254 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
255 * @inode: inode of metadata file using this allocator
256 * @group: group number
257 * @create: create flag
258 * @bhp: pointer to store the resultant buffer head
259 */
260static int nilfs_palloc_get_desc_block(struct inode *inode,
261 unsigned long group,
262 int create, struct buffer_head **bhp)
263{
264 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
265
266 return nilfs_palloc_get_block(inode,
267 nilfs_palloc_desc_blkoff(inode, group),
268 create, nilfs_palloc_desc_block_init,
269 bhp, &cache->prev_desc, &cache->lock);
270}
271
272/**
273 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
274 * @inode: inode of metadata file using this allocator
275 * @group: group number
276 * @create: create flag
277 * @bhp: pointer to store the resultant buffer head
278 */
279static int nilfs_palloc_get_bitmap_block(struct inode *inode,
280 unsigned long group,
281 int create, struct buffer_head **bhp)
282{
283 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
284
285 return nilfs_palloc_get_block(inode,
286 nilfs_palloc_bitmap_blkoff(inode, group),
287 create, NULL, bhp,
288 &cache->prev_bitmap, &cache->lock);
289}
290
291/**
292 * nilfs_palloc_delete_bitmap_block - delete a bitmap block
293 * @inode: inode of metadata file using this allocator
294 * @group: group number
295 */
296static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
297 unsigned long group)
298{
299 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
300
301 return nilfs_palloc_delete_block(inode,
302 nilfs_palloc_bitmap_blkoff(inode,
303 group),
304 &cache->prev_bitmap, &cache->lock);
305}
306
307/**
308 * nilfs_palloc_get_entry_block - get buffer head of an entry block
309 * @inode: inode of metadata file using this allocator
310 * @nr: serial number of the entry (e.g. inode number)
311 * @create: create flag
312 * @bhp: pointer to store the resultant buffer head
313 */
314int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
315 int create, struct buffer_head **bhp)
316{
317 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
318
319 return nilfs_palloc_get_block(inode,
320 nilfs_palloc_entry_blkoff(inode, nr),
321 create, NULL, bhp,
322 &cache->prev_entry, &cache->lock);
323}
324
325/**
326 * nilfs_palloc_delete_entry_block - delete an entry block
327 * @inode: inode of metadata file using this allocator
328 * @nr: serial number of the entry
329 */
330static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
331{
332 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
333
334 return nilfs_palloc_delete_block(inode,
335 nilfs_palloc_entry_blkoff(inode, nr),
336 &cache->prev_entry, &cache->lock);
337}
338
339/**
340 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
341 * @inode: inode of metadata file using this allocator
342 * @group: group number
343 * @bh: buffer head of the buffer storing the group descriptor block
344 * @kaddr: kernel address mapped for the page including the buffer
345 */
346static struct nilfs_palloc_group_desc *
347nilfs_palloc_block_get_group_desc(const struct inode *inode,
348 unsigned long group,
349 const struct buffer_head *bh, void *kaddr)
350{
351 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
352 group % nilfs_palloc_groups_per_desc_block(inode);
353}
354
355/**
356 * nilfs_palloc_block_get_entry - get kernel address of an entry
357 * @inode: inode of metadata file using this allocator
358 * @nr: serial number of the entry (e.g. inode number)
359 * @bh: buffer head of the buffer storing the entry block
360 * @kaddr: kernel address mapped for the page including the buffer
361 */
362void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
363 const struct buffer_head *bh, void *kaddr)
364{
365 unsigned long entry_offset, group_offset;
366
367 nilfs_palloc_group(inode, nr, &group_offset);
368 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
369
370 return kaddr + bh_offset(bh) +
371 entry_offset * NILFS_MDT(inode)->mi_entry_size;
372}
373
374/**
375 * nilfs_palloc_find_available_slot - find available slot in a group
376 * @bitmap: bitmap of the group
377 * @target: offset number of an entry in the group (start point)
378 * @bsize: size in bits
379 * @lock: spin lock protecting @bitmap
380 */
381static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
382 unsigned long target,
383 unsigned int bsize,
384 spinlock_t *lock)
385{
386 int pos, end = bsize;
387
388 if (likely(target < bsize)) {
389 pos = target;
390 do {
391 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
392 if (pos >= end)
393 break;
394 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
395 return pos;
396 } while (++pos < end);
397
398 end = target;
399 }
400
401 /* wrap around */
402 for (pos = 0; pos < end; pos++) {
403 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
404 if (pos >= end)
405 break;
406 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
407 return pos;
408 }
409
410 return -ENOSPC;
411}
412
413/**
414 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
415 * in a group descriptor block
416 * @inode: inode of metadata file using this allocator
417 * @curr: current group number
418 * @max: maximum number of groups
419 */
420static unsigned long
421nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
422 unsigned long curr, unsigned long max)
423{
424 return min_t(unsigned long,
425 nilfs_palloc_groups_per_desc_block(inode) -
426 curr % nilfs_palloc_groups_per_desc_block(inode),
427 max - curr + 1);
428}
429
430/**
431 * nilfs_palloc_count_desc_blocks - count descriptor blocks number
432 * @inode: inode of metadata file using this allocator
433 * @desc_blocks: descriptor blocks number [out]
434 */
435static int nilfs_palloc_count_desc_blocks(struct inode *inode,
436 unsigned long *desc_blocks)
437{
438 __u64 blknum;
439 int ret;
440
441 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
442 if (likely(!ret))
443 *desc_blocks = DIV_ROUND_UP(
444 (unsigned long)blknum,
445 NILFS_MDT(inode)->mi_blocks_per_desc_block);
446 return ret;
447}
448
449/**
450 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
451 * MDT file growing
452 * @inode: inode of metadata file using this allocator
453 * @desc_blocks: known current descriptor blocks count
454 */
455static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
456 unsigned long desc_blocks)
457{
458 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
459 nilfs_palloc_groups_count(inode);
460}
461
462/**
463 * nilfs_palloc_count_max_entries - count max number of entries that can be
464 * described by descriptor blocks count
465 * @inode: inode of metadata file using this allocator
466 * @nused: current number of used entries
467 * @nmaxp: max number of entries [out]
468 */
469int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
470{
471 unsigned long desc_blocks = 0;
472 u64 entries_per_desc_block, nmax;
473 int err;
474
475 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
476 if (unlikely(err))
477 return err;
478
479 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
480 nilfs_palloc_groups_per_desc_block(inode);
481 nmax = entries_per_desc_block * desc_blocks;
482
483 if (nused == nmax &&
484 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
485 nmax += entries_per_desc_block;
486
487 if (nused > nmax)
488 return -ERANGE;
489
490 *nmaxp = nmax;
491 return 0;
492}
493
494/**
495 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
496 * @inode: inode of metadata file using this allocator
497 * @req: nilfs_palloc_req structure exchanged for the allocation
498 */
499int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
500 struct nilfs_palloc_req *req)
501{
502 struct buffer_head *desc_bh, *bitmap_bh;
503 struct nilfs_palloc_group_desc *desc;
504 unsigned char *bitmap;
505 void *desc_kaddr, *bitmap_kaddr;
506 unsigned long group, maxgroup, ngroups;
507 unsigned long group_offset, maxgroup_offset;
508 unsigned long n, entries_per_group;
509 unsigned long i, j;
510 spinlock_t *lock;
511 int pos, ret;
512
513 ngroups = nilfs_palloc_groups_count(inode);
514 maxgroup = ngroups - 1;
515 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
516 entries_per_group = nilfs_palloc_entries_per_group(inode);
517
518 for (i = 0; i < ngroups; i += n) {
519 if (group >= ngroups) {
520 /* wrap around */
521 group = 0;
522 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
523 &maxgroup_offset) - 1;
524 }
525 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
526 if (ret < 0)
527 return ret;
528 desc_kaddr = kmap(desc_bh->b_page);
529 desc = nilfs_palloc_block_get_group_desc(
530 inode, group, desc_bh, desc_kaddr);
531 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
532 maxgroup);
533 for (j = 0; j < n; j++, desc++, group++) {
534 lock = nilfs_mdt_bgl_lock(inode, group);
535 if (nilfs_palloc_group_desc_nfrees(desc, lock) > 0) {
536 ret = nilfs_palloc_get_bitmap_block(
537 inode, group, 1, &bitmap_bh);
538 if (ret < 0)
539 goto out_desc;
540 bitmap_kaddr = kmap(bitmap_bh->b_page);
541 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
542 pos = nilfs_palloc_find_available_slot(
543 bitmap, group_offset,
544 entries_per_group, lock);
545 if (pos >= 0) {
546 /* found a free entry */
547 nilfs_palloc_group_desc_add_entries(
548 desc, lock, -1);
549 req->pr_entry_nr =
550 entries_per_group * group + pos;
551 kunmap(desc_bh->b_page);
552 kunmap(bitmap_bh->b_page);
553
554 req->pr_desc_bh = desc_bh;
555 req->pr_bitmap_bh = bitmap_bh;
556 return 0;
557 }
558 kunmap(bitmap_bh->b_page);
559 brelse(bitmap_bh);
560 }
561
562 group_offset = 0;
563 }
564
565 kunmap(desc_bh->b_page);
566 brelse(desc_bh);
567 }
568
569 /* no entries left */
570 return -ENOSPC;
571
572 out_desc:
573 kunmap(desc_bh->b_page);
574 brelse(desc_bh);
575 return ret;
576}
577
578/**
579 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
580 * @inode: inode of metadata file using this allocator
581 * @req: nilfs_palloc_req structure exchanged for the allocation
582 */
583void nilfs_palloc_commit_alloc_entry(struct inode *inode,
584 struct nilfs_palloc_req *req)
585{
586 mark_buffer_dirty(req->pr_bitmap_bh);
587 mark_buffer_dirty(req->pr_desc_bh);
588 nilfs_mdt_mark_dirty(inode);
589
590 brelse(req->pr_bitmap_bh);
591 brelse(req->pr_desc_bh);
592}
593
594/**
595 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
596 * @inode: inode of metadata file using this allocator
597 * @req: nilfs_palloc_req structure exchanged for the removal
598 */
599void nilfs_palloc_commit_free_entry(struct inode *inode,
600 struct nilfs_palloc_req *req)
601{
602 struct nilfs_palloc_group_desc *desc;
603 unsigned long group, group_offset;
604 unsigned char *bitmap;
605 void *desc_kaddr, *bitmap_kaddr;
606 spinlock_t *lock;
607
608 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
609 desc_kaddr = kmap(req->pr_desc_bh->b_page);
610 desc = nilfs_palloc_block_get_group_desc(inode, group,
611 req->pr_desc_bh, desc_kaddr);
612 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
613 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
614 lock = nilfs_mdt_bgl_lock(inode, group);
615
616 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
617 nilfs_warn(inode->i_sb,
618 "%s (ino=%lu): entry number %llu already freed",
619 __func__, inode->i_ino,
620 (unsigned long long)req->pr_entry_nr);
621 else
622 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
623
624 kunmap(req->pr_bitmap_bh->b_page);
625 kunmap(req->pr_desc_bh->b_page);
626
627 mark_buffer_dirty(req->pr_desc_bh);
628 mark_buffer_dirty(req->pr_bitmap_bh);
629 nilfs_mdt_mark_dirty(inode);
630
631 brelse(req->pr_bitmap_bh);
632 brelse(req->pr_desc_bh);
633}
634
635/**
636 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
637 * @inode: inode of metadata file using this allocator
638 * @req: nilfs_palloc_req structure exchanged for the allocation
639 */
640void nilfs_palloc_abort_alloc_entry(struct inode *inode,
641 struct nilfs_palloc_req *req)
642{
643 struct nilfs_palloc_group_desc *desc;
644 void *desc_kaddr, *bitmap_kaddr;
645 unsigned char *bitmap;
646 unsigned long group, group_offset;
647 spinlock_t *lock;
648
649 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
650 desc_kaddr = kmap(req->pr_desc_bh->b_page);
651 desc = nilfs_palloc_block_get_group_desc(inode, group,
652 req->pr_desc_bh, desc_kaddr);
653 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
654 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
655 lock = nilfs_mdt_bgl_lock(inode, group);
656
657 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
658 nilfs_warn(inode->i_sb,
659 "%s (ino=%lu): entry number %llu already freed",
660 __func__, inode->i_ino,
661 (unsigned long long)req->pr_entry_nr);
662 else
663 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
664
665 kunmap(req->pr_bitmap_bh->b_page);
666 kunmap(req->pr_desc_bh->b_page);
667
668 brelse(req->pr_bitmap_bh);
669 brelse(req->pr_desc_bh);
670
671 req->pr_entry_nr = 0;
672 req->pr_bitmap_bh = NULL;
673 req->pr_desc_bh = NULL;
674}
675
676/**
677 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
678 * @inode: inode of metadata file using this allocator
679 * @req: nilfs_palloc_req structure exchanged for the removal
680 */
681int nilfs_palloc_prepare_free_entry(struct inode *inode,
682 struct nilfs_palloc_req *req)
683{
684 struct buffer_head *desc_bh, *bitmap_bh;
685 unsigned long group, group_offset;
686 int ret;
687
688 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
689 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
690 if (ret < 0)
691 return ret;
692 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
693 if (ret < 0) {
694 brelse(desc_bh);
695 return ret;
696 }
697
698 req->pr_desc_bh = desc_bh;
699 req->pr_bitmap_bh = bitmap_bh;
700 return 0;
701}
702
703/**
704 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
705 * @inode: inode of metadata file using this allocator
706 * @req: nilfs_palloc_req structure exchanged for the removal
707 */
708void nilfs_palloc_abort_free_entry(struct inode *inode,
709 struct nilfs_palloc_req *req)
710{
711 brelse(req->pr_bitmap_bh);
712 brelse(req->pr_desc_bh);
713
714 req->pr_entry_nr = 0;
715 req->pr_bitmap_bh = NULL;
716 req->pr_desc_bh = NULL;
717}
718
719/**
720 * nilfs_palloc_freev - deallocate a set of persistent objects
721 * @inode: inode of metadata file using this allocator
722 * @entry_nrs: array of entry numbers to be deallocated
723 * @nitems: number of entries stored in @entry_nrs
724 */
725int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
726{
727 struct buffer_head *desc_bh, *bitmap_bh;
728 struct nilfs_palloc_group_desc *desc;
729 unsigned char *bitmap;
730 void *desc_kaddr, *bitmap_kaddr;
731 unsigned long group, group_offset;
732 __u64 group_min_nr, last_nrs[8];
733 const unsigned long epg = nilfs_palloc_entries_per_group(inode);
734 const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
735 unsigned int entry_start, end, pos;
736 spinlock_t *lock;
737 int i, j, k, ret;
738 u32 nfree;
739
740 for (i = 0; i < nitems; i = j) {
741 int change_group = false;
742 int nempties = 0, n = 0;
743
744 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
745 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
746 if (ret < 0)
747 return ret;
748 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
749 &bitmap_bh);
750 if (ret < 0) {
751 brelse(desc_bh);
752 return ret;
753 }
754
755 /* Get the first entry number of the group */
756 group_min_nr = (__u64)group * epg;
757
758 bitmap_kaddr = kmap(bitmap_bh->b_page);
759 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
760 lock = nilfs_mdt_bgl_lock(inode, group);
761
762 j = i;
763 entry_start = rounddown(group_offset, epb);
764 do {
765 if (!nilfs_clear_bit_atomic(lock, group_offset,
766 bitmap)) {
767 nilfs_warn(inode->i_sb,
768 "%s (ino=%lu): entry number %llu already freed",
769 __func__, inode->i_ino,
770 (unsigned long long)entry_nrs[j]);
771 } else {
772 n++;
773 }
774
775 j++;
776 if (j >= nitems || entry_nrs[j] < group_min_nr ||
777 entry_nrs[j] >= group_min_nr + epg) {
778 change_group = true;
779 } else {
780 group_offset = entry_nrs[j] - group_min_nr;
781 if (group_offset >= entry_start &&
782 group_offset < entry_start + epb) {
783 /* This entry is in the same block */
784 continue;
785 }
786 }
787
788 /* Test if the entry block is empty or not */
789 end = entry_start + epb;
790 pos = nilfs_find_next_bit(bitmap, end, entry_start);
791 if (pos >= end) {
792 last_nrs[nempties++] = entry_nrs[j - 1];
793 if (nempties >= ARRAY_SIZE(last_nrs))
794 break;
795 }
796
797 if (change_group)
798 break;
799
800 /* Go on to the next entry block */
801 entry_start = rounddown(group_offset, epb);
802 } while (true);
803
804 kunmap(bitmap_bh->b_page);
805 mark_buffer_dirty(bitmap_bh);
806 brelse(bitmap_bh);
807
808 for (k = 0; k < nempties; k++) {
809 ret = nilfs_palloc_delete_entry_block(inode,
810 last_nrs[k]);
811 if (ret && ret != -ENOENT)
812 nilfs_warn(inode->i_sb,
813 "error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
814 ret, (unsigned long long)last_nrs[k],
815 inode->i_ino);
816 }
817
818 desc_kaddr = kmap_atomic(desc_bh->b_page);
819 desc = nilfs_palloc_block_get_group_desc(
820 inode, group, desc_bh, desc_kaddr);
821 nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
822 kunmap_atomic(desc_kaddr);
823 mark_buffer_dirty(desc_bh);
824 nilfs_mdt_mark_dirty(inode);
825 brelse(desc_bh);
826
827 if (nfree == nilfs_palloc_entries_per_group(inode)) {
828 ret = nilfs_palloc_delete_bitmap_block(inode, group);
829 if (ret && ret != -ENOENT)
830 nilfs_warn(inode->i_sb,
831 "error %d deleting bitmap block of group=%lu, ino=%lu",
832 ret, group, inode->i_ino);
833 }
834 }
835 return 0;
836}
837
838void nilfs_palloc_setup_cache(struct inode *inode,
839 struct nilfs_palloc_cache *cache)
840{
841 NILFS_MDT(inode)->mi_palloc_cache = cache;
842 spin_lock_init(&cache->lock);
843}
844
845void nilfs_palloc_clear_cache(struct inode *inode)
846{
847 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
848
849 spin_lock(&cache->lock);
850 brelse(cache->prev_desc.bh);
851 brelse(cache->prev_bitmap.bh);
852 brelse(cache->prev_entry.bh);
853 cache->prev_desc.bh = NULL;
854 cache->prev_bitmap.bh = NULL;
855 cache->prev_entry.bh = NULL;
856 spin_unlock(&cache->lock);
857}
858
859void nilfs_palloc_destroy_cache(struct inode *inode)
860{
861 nilfs_palloc_clear_cache(inode);
862 NILFS_MDT(inode)->mi_palloc_cache = NULL;
863}
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}