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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 * Originally written by Koji Sato.
17 * Two allocators were unified by Ryusuke Konishi and Amagai Yoshiji.
18 */
19
20#include <linux/types.h>
21#include <linux/buffer_head.h>
22#include <linux/fs.h>
23#include <linux/bitops.h>
24#include <linux/slab.h>
25#include "mdt.h"
26#include "alloc.h"
27
28
29/**
30 * nilfs_palloc_groups_per_desc_block - get the number of groups that a group
31 * descriptor block can maintain
32 * @inode: inode of metadata file using this allocator
33 */
34static inline unsigned long
35nilfs_palloc_groups_per_desc_block(const struct inode *inode)
36{
37 return i_blocksize(inode) /
38 sizeof(struct nilfs_palloc_group_desc);
39}
40
41/**
42 * nilfs_palloc_groups_count - get maximum number of groups
43 * @inode: inode of metadata file using this allocator
44 */
45static inline unsigned long
46nilfs_palloc_groups_count(const struct inode *inode)
47{
48 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
49}
50
51/**
52 * nilfs_palloc_init_blockgroup - initialize private variables for allocator
53 * @inode: inode of metadata file using this allocator
54 * @entry_size: size of the persistent object
55 */
56int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned int entry_size)
57{
58 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
59
60 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
61 if (!mi->mi_bgl)
62 return -ENOMEM;
63
64 bgl_lock_init(mi->mi_bgl);
65
66 nilfs_mdt_set_entry_size(inode, entry_size, 0);
67
68 mi->mi_blocks_per_group =
69 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
70 mi->mi_entries_per_block) + 1;
71 /*
72 * Number of blocks in a group including entry blocks
73 * and a bitmap block
74 */
75 mi->mi_blocks_per_desc_block =
76 nilfs_palloc_groups_per_desc_block(inode) *
77 mi->mi_blocks_per_group + 1;
78 /*
79 * Number of blocks per descriptor including the
80 * descriptor block
81 */
82 return 0;
83}
84
85/**
86 * nilfs_palloc_group - get group number and offset from an entry number
87 * @inode: inode of metadata file using this allocator
88 * @nr: serial number of the entry (e.g. inode number)
89 * @offset: pointer to store offset number in the group
90 */
91static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
92 unsigned long *offset)
93{
94 __u64 group = nr;
95
96 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
97 return group;
98}
99
100/**
101 * nilfs_palloc_desc_blkoff - get block offset of a group descriptor block
102 * @inode: inode of metadata file using this allocator
103 * @group: group number
104 *
105 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor
106 * block which contains a descriptor of the specified group.
107 */
108static unsigned long
109nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
110{
111 unsigned long desc_block =
112 group / nilfs_palloc_groups_per_desc_block(inode);
113 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
114}
115
116/**
117 * nilfs_palloc_bitmap_blkoff - get block offset of a bitmap block
118 * @inode: inode of metadata file using this allocator
119 * @group: group number
120 *
121 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap
122 * block used to allocate/deallocate entries in the specified group.
123 */
124static unsigned long
125nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
126{
127 unsigned long desc_offset =
128 group % nilfs_palloc_groups_per_desc_block(inode);
129 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
130 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
131}
132
133/**
134 * nilfs_palloc_group_desc_nfrees - get the number of free entries in a group
135 * @desc: pointer to descriptor structure for the group
136 * @lock: spin lock protecting @desc
137 */
138static unsigned long
139nilfs_palloc_group_desc_nfrees(const struct nilfs_palloc_group_desc *desc,
140 spinlock_t *lock)
141{
142 unsigned long nfree;
143
144 spin_lock(lock);
145 nfree = le32_to_cpu(desc->pg_nfrees);
146 spin_unlock(lock);
147 return nfree;
148}
149
150/**
151 * nilfs_palloc_group_desc_add_entries - adjust count of free entries
152 * @desc: pointer to descriptor structure for the group
153 * @lock: spin lock protecting @desc
154 * @n: delta to be added
155 */
156static u32
157nilfs_palloc_group_desc_add_entries(struct nilfs_palloc_group_desc *desc,
158 spinlock_t *lock, u32 n)
159{
160 u32 nfree;
161
162 spin_lock(lock);
163 le32_add_cpu(&desc->pg_nfrees, n);
164 nfree = le32_to_cpu(desc->pg_nfrees);
165 spin_unlock(lock);
166 return nfree;
167}
168
169/**
170 * nilfs_palloc_entry_blkoff - get block offset of an entry block
171 * @inode: inode of metadata file using this allocator
172 * @nr: serial number of the entry (e.g. inode number)
173 */
174static unsigned long
175nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
176{
177 unsigned long group, group_offset;
178
179 group = nilfs_palloc_group(inode, nr, &group_offset);
180
181 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
182 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
183}
184
185/**
186 * nilfs_palloc_desc_block_init - initialize buffer of a group descriptor block
187 * @inode: inode of metadata file
188 * @bh: buffer head of the buffer to be initialized
189 * @kaddr: kernel address mapped for the page including the buffer
190 */
191static void nilfs_palloc_desc_block_init(struct inode *inode,
192 struct buffer_head *bh, void *kaddr)
193{
194 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
195 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
196 __le32 nfrees;
197
198 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
199 while (n-- > 0) {
200 desc->pg_nfrees = nfrees;
201 desc++;
202 }
203}
204
205static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
206 int create,
207 void (*init_block)(struct inode *,
208 struct buffer_head *,
209 void *),
210 struct buffer_head **bhp,
211 struct nilfs_bh_assoc *prev,
212 spinlock_t *lock)
213{
214 int ret;
215
216 spin_lock(lock);
217 if (prev->bh && blkoff == prev->blkoff) {
218 get_bh(prev->bh);
219 *bhp = prev->bh;
220 spin_unlock(lock);
221 return 0;
222 }
223 spin_unlock(lock);
224
225 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
226 if (!ret) {
227 spin_lock(lock);
228 /*
229 * The following code must be safe for change of the
230 * cache contents during the get block call.
231 */
232 brelse(prev->bh);
233 get_bh(*bhp);
234 prev->bh = *bhp;
235 prev->blkoff = blkoff;
236 spin_unlock(lock);
237 }
238 return ret;
239}
240
241/**
242 * nilfs_palloc_delete_block - delete a block on the persistent allocator file
243 * @inode: inode of metadata file using this allocator
244 * @blkoff: block offset
245 * @prev: nilfs_bh_assoc struct of the last used buffer
246 * @lock: spin lock protecting @prev
247 */
248static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
249 struct nilfs_bh_assoc *prev,
250 spinlock_t *lock)
251{
252 spin_lock(lock);
253 if (prev->bh && blkoff == prev->blkoff) {
254 brelse(prev->bh);
255 prev->bh = NULL;
256 }
257 spin_unlock(lock);
258 return nilfs_mdt_delete_block(inode, blkoff);
259}
260
261/**
262 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor 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_desc_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_desc_blkoff(inode, group),
276 create, nilfs_palloc_desc_block_init,
277 bhp, &cache->prev_desc, &cache->lock);
278}
279
280/**
281 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
282 * @inode: inode of metadata file using this allocator
283 * @group: group number
284 * @create: create flag
285 * @bhp: pointer to store the resultant buffer head
286 */
287static int nilfs_palloc_get_bitmap_block(struct inode *inode,
288 unsigned long group,
289 int create, struct buffer_head **bhp)
290{
291 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
292
293 return nilfs_palloc_get_block(inode,
294 nilfs_palloc_bitmap_blkoff(inode, group),
295 create, NULL, bhp,
296 &cache->prev_bitmap, &cache->lock);
297}
298
299/**
300 * nilfs_palloc_delete_bitmap_block - delete a bitmap block
301 * @inode: inode of metadata file using this allocator
302 * @group: group number
303 */
304static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
305 unsigned long group)
306{
307 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
308
309 return nilfs_palloc_delete_block(inode,
310 nilfs_palloc_bitmap_blkoff(inode,
311 group),
312 &cache->prev_bitmap, &cache->lock);
313}
314
315/**
316 * nilfs_palloc_get_entry_block - get buffer head of an entry block
317 * @inode: inode of metadata file using this allocator
318 * @nr: serial number of the entry (e.g. inode number)
319 * @create: create flag
320 * @bhp: pointer to store the resultant buffer head
321 */
322int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
323 int create, struct buffer_head **bhp)
324{
325 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
326
327 return nilfs_palloc_get_block(inode,
328 nilfs_palloc_entry_blkoff(inode, nr),
329 create, NULL, bhp,
330 &cache->prev_entry, &cache->lock);
331}
332
333/**
334 * nilfs_palloc_delete_entry_block - delete an entry block
335 * @inode: inode of metadata file using this allocator
336 * @nr: serial number of the entry
337 */
338static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
339{
340 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
341
342 return nilfs_palloc_delete_block(inode,
343 nilfs_palloc_entry_blkoff(inode, nr),
344 &cache->prev_entry, &cache->lock);
345}
346
347/**
348 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
349 * @inode: inode of metadata file using this allocator
350 * @group: group number
351 * @bh: buffer head of the buffer storing the group descriptor block
352 * @kaddr: kernel address mapped for the page including the buffer
353 */
354static struct nilfs_palloc_group_desc *
355nilfs_palloc_block_get_group_desc(const struct inode *inode,
356 unsigned long group,
357 const struct buffer_head *bh, void *kaddr)
358{
359 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
360 group % nilfs_palloc_groups_per_desc_block(inode);
361}
362
363/**
364 * nilfs_palloc_block_get_entry - get kernel address of an entry
365 * @inode: inode of metadata file using this allocator
366 * @nr: serial number of the entry (e.g. inode number)
367 * @bh: buffer head of the buffer storing the entry block
368 * @kaddr: kernel address mapped for the page including the buffer
369 */
370void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
371 const struct buffer_head *bh, void *kaddr)
372{
373 unsigned long entry_offset, group_offset;
374
375 nilfs_palloc_group(inode, nr, &group_offset);
376 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
377
378 return kaddr + bh_offset(bh) +
379 entry_offset * NILFS_MDT(inode)->mi_entry_size;
380}
381
382/**
383 * nilfs_palloc_find_available_slot - find available slot in a group
384 * @bitmap: bitmap of the group
385 * @target: offset number of an entry in the group (start point)
386 * @bsize: size in bits
387 * @lock: spin lock protecting @bitmap
388 */
389static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
390 unsigned long target,
391 unsigned int bsize,
392 spinlock_t *lock)
393{
394 int pos, end = bsize;
395
396 if (likely(target < bsize)) {
397 pos = target;
398 do {
399 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
400 if (pos >= end)
401 break;
402 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
403 return pos;
404 } while (++pos < end);
405
406 end = target;
407 }
408
409 /* wrap around */
410 for (pos = 0; pos < end; pos++) {
411 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
412 if (pos >= end)
413 break;
414 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
415 return pos;
416 }
417
418 return -ENOSPC;
419}
420
421/**
422 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
423 * in a group descriptor block
424 * @inode: inode of metadata file using this allocator
425 * @curr: current group number
426 * @max: maximum number of groups
427 */
428static unsigned long
429nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
430 unsigned long curr, unsigned long max)
431{
432 return min_t(unsigned long,
433 nilfs_palloc_groups_per_desc_block(inode) -
434 curr % nilfs_palloc_groups_per_desc_block(inode),
435 max - curr + 1);
436}
437
438/**
439 * nilfs_palloc_count_desc_blocks - count descriptor blocks number
440 * @inode: inode of metadata file using this allocator
441 * @desc_blocks: descriptor blocks number [out]
442 */
443static int nilfs_palloc_count_desc_blocks(struct inode *inode,
444 unsigned long *desc_blocks)
445{
446 __u64 blknum;
447 int ret;
448
449 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
450 if (likely(!ret))
451 *desc_blocks = DIV_ROUND_UP(
452 (unsigned long)blknum,
453 NILFS_MDT(inode)->mi_blocks_per_desc_block);
454 return ret;
455}
456
457/**
458 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
459 * MDT file growing
460 * @inode: inode of metadata file using this allocator
461 * @desc_blocks: known current descriptor blocks count
462 */
463static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
464 unsigned long desc_blocks)
465{
466 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
467 nilfs_palloc_groups_count(inode);
468}
469
470/**
471 * nilfs_palloc_count_max_entries - count max number of entries that can be
472 * described by descriptor blocks count
473 * @inode: inode of metadata file using this allocator
474 * @nused: current number of used entries
475 * @nmaxp: max number of entries [out]
476 */
477int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
478{
479 unsigned long desc_blocks = 0;
480 u64 entries_per_desc_block, nmax;
481 int err;
482
483 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
484 if (unlikely(err))
485 return err;
486
487 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
488 nilfs_palloc_groups_per_desc_block(inode);
489 nmax = entries_per_desc_block * desc_blocks;
490
491 if (nused == nmax &&
492 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
493 nmax += entries_per_desc_block;
494
495 if (nused > nmax)
496 return -ERANGE;
497
498 *nmaxp = nmax;
499 return 0;
500}
501
502/**
503 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
504 * @inode: inode of metadata file using this allocator
505 * @req: nilfs_palloc_req structure exchanged for the allocation
506 */
507int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
508 struct nilfs_palloc_req *req)
509{
510 struct buffer_head *desc_bh, *bitmap_bh;
511 struct nilfs_palloc_group_desc *desc;
512 unsigned char *bitmap;
513 void *desc_kaddr, *bitmap_kaddr;
514 unsigned long group, maxgroup, ngroups;
515 unsigned long group_offset, maxgroup_offset;
516 unsigned long n, entries_per_group;
517 unsigned long i, j;
518 spinlock_t *lock;
519 int pos, ret;
520
521 ngroups = nilfs_palloc_groups_count(inode);
522 maxgroup = ngroups - 1;
523 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
524 entries_per_group = nilfs_palloc_entries_per_group(inode);
525
526 for (i = 0; i < ngroups; i += n) {
527 if (group >= ngroups) {
528 /* wrap around */
529 group = 0;
530 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
531 &maxgroup_offset) - 1;
532 }
533 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
534 if (ret < 0)
535 return ret;
536 desc_kaddr = kmap(desc_bh->b_page);
537 desc = nilfs_palloc_block_get_group_desc(
538 inode, group, desc_bh, desc_kaddr);
539 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
540 maxgroup);
541 for (j = 0; j < n; j++, desc++, group++) {
542 lock = nilfs_mdt_bgl_lock(inode, group);
543 if (nilfs_palloc_group_desc_nfrees(desc, lock) > 0) {
544 ret = nilfs_palloc_get_bitmap_block(
545 inode, group, 1, &bitmap_bh);
546 if (ret < 0)
547 goto out_desc;
548 bitmap_kaddr = kmap(bitmap_bh->b_page);
549 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
550 pos = nilfs_palloc_find_available_slot(
551 bitmap, group_offset,
552 entries_per_group, lock);
553 if (pos >= 0) {
554 /* found a free entry */
555 nilfs_palloc_group_desc_add_entries(
556 desc, lock, -1);
557 req->pr_entry_nr =
558 entries_per_group * group + pos;
559 kunmap(desc_bh->b_page);
560 kunmap(bitmap_bh->b_page);
561
562 req->pr_desc_bh = desc_bh;
563 req->pr_bitmap_bh = bitmap_bh;
564 return 0;
565 }
566 kunmap(bitmap_bh->b_page);
567 brelse(bitmap_bh);
568 }
569
570 group_offset = 0;
571 }
572
573 kunmap(desc_bh->b_page);
574 brelse(desc_bh);
575 }
576
577 /* no entries left */
578 return -ENOSPC;
579
580 out_desc:
581 kunmap(desc_bh->b_page);
582 brelse(desc_bh);
583 return ret;
584}
585
586/**
587 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
588 * @inode: inode of metadata file using this allocator
589 * @req: nilfs_palloc_req structure exchanged for the allocation
590 */
591void nilfs_palloc_commit_alloc_entry(struct inode *inode,
592 struct nilfs_palloc_req *req)
593{
594 mark_buffer_dirty(req->pr_bitmap_bh);
595 mark_buffer_dirty(req->pr_desc_bh);
596 nilfs_mdt_mark_dirty(inode);
597
598 brelse(req->pr_bitmap_bh);
599 brelse(req->pr_desc_bh);
600}
601
602/**
603 * nilfs_palloc_commit_free_entry - finish 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_commit_free_entry(struct inode *inode,
608 struct nilfs_palloc_req *req)
609{
610 struct nilfs_palloc_group_desc *desc;
611 unsigned long group, group_offset;
612 unsigned char *bitmap;
613 void *desc_kaddr, *bitmap_kaddr;
614 spinlock_t *lock;
615
616 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
617 desc_kaddr = kmap(req->pr_desc_bh->b_page);
618 desc = nilfs_palloc_block_get_group_desc(inode, group,
619 req->pr_desc_bh, desc_kaddr);
620 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
621 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
622 lock = nilfs_mdt_bgl_lock(inode, group);
623
624 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
625 nilfs_msg(inode->i_sb, KERN_WARNING,
626 "%s (ino=%lu): entry number %llu already freed",
627 __func__, inode->i_ino,
628 (unsigned long long)req->pr_entry_nr);
629 else
630 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
631
632 kunmap(req->pr_bitmap_bh->b_page);
633 kunmap(req->pr_desc_bh->b_page);
634
635 mark_buffer_dirty(req->pr_desc_bh);
636 mark_buffer_dirty(req->pr_bitmap_bh);
637 nilfs_mdt_mark_dirty(inode);
638
639 brelse(req->pr_bitmap_bh);
640 brelse(req->pr_desc_bh);
641}
642
643/**
644 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
645 * @inode: inode of metadata file using this allocator
646 * @req: nilfs_palloc_req structure exchanged for the allocation
647 */
648void nilfs_palloc_abort_alloc_entry(struct inode *inode,
649 struct nilfs_palloc_req *req)
650{
651 struct nilfs_palloc_group_desc *desc;
652 void *desc_kaddr, *bitmap_kaddr;
653 unsigned char *bitmap;
654 unsigned long group, group_offset;
655 spinlock_t *lock;
656
657 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
658 desc_kaddr = kmap(req->pr_desc_bh->b_page);
659 desc = nilfs_palloc_block_get_group_desc(inode, group,
660 req->pr_desc_bh, desc_kaddr);
661 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
662 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
663 lock = nilfs_mdt_bgl_lock(inode, group);
664
665 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
666 nilfs_msg(inode->i_sb, KERN_WARNING,
667 "%s (ino=%lu): entry number %llu already freed",
668 __func__, inode->i_ino,
669 (unsigned long long)req->pr_entry_nr);
670 else
671 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
672
673 kunmap(req->pr_bitmap_bh->b_page);
674 kunmap(req->pr_desc_bh->b_page);
675
676 brelse(req->pr_bitmap_bh);
677 brelse(req->pr_desc_bh);
678
679 req->pr_entry_nr = 0;
680 req->pr_bitmap_bh = NULL;
681 req->pr_desc_bh = NULL;
682}
683
684/**
685 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
686 * @inode: inode of metadata file using this allocator
687 * @req: nilfs_palloc_req structure exchanged for the removal
688 */
689int nilfs_palloc_prepare_free_entry(struct inode *inode,
690 struct nilfs_palloc_req *req)
691{
692 struct buffer_head *desc_bh, *bitmap_bh;
693 unsigned long group, group_offset;
694 int ret;
695
696 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
697 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
698 if (ret < 0)
699 return ret;
700 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
701 if (ret < 0) {
702 brelse(desc_bh);
703 return ret;
704 }
705
706 req->pr_desc_bh = desc_bh;
707 req->pr_bitmap_bh = bitmap_bh;
708 return 0;
709}
710
711/**
712 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
713 * @inode: inode of metadata file using this allocator
714 * @req: nilfs_palloc_req structure exchanged for the removal
715 */
716void nilfs_palloc_abort_free_entry(struct inode *inode,
717 struct nilfs_palloc_req *req)
718{
719 brelse(req->pr_bitmap_bh);
720 brelse(req->pr_desc_bh);
721
722 req->pr_entry_nr = 0;
723 req->pr_bitmap_bh = NULL;
724 req->pr_desc_bh = NULL;
725}
726
727/**
728 * nilfs_palloc_freev - deallocate a set of persistent objects
729 * @inode: inode of metadata file using this allocator
730 * @entry_nrs: array of entry numbers to be deallocated
731 * @nitems: number of entries stored in @entry_nrs
732 */
733int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
734{
735 struct buffer_head *desc_bh, *bitmap_bh;
736 struct nilfs_palloc_group_desc *desc;
737 unsigned char *bitmap;
738 void *desc_kaddr, *bitmap_kaddr;
739 unsigned long group, group_offset;
740 __u64 group_min_nr, last_nrs[8];
741 const unsigned long epg = nilfs_palloc_entries_per_group(inode);
742 const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
743 unsigned int entry_start, end, pos;
744 spinlock_t *lock;
745 int i, j, k, ret;
746 u32 nfree;
747
748 for (i = 0; i < nitems; i = j) {
749 int change_group = false;
750 int nempties = 0, n = 0;
751
752 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
753 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
754 if (ret < 0)
755 return ret;
756 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
757 &bitmap_bh);
758 if (ret < 0) {
759 brelse(desc_bh);
760 return ret;
761 }
762
763 /* Get the first entry number of the group */
764 group_min_nr = (__u64)group * epg;
765
766 bitmap_kaddr = kmap(bitmap_bh->b_page);
767 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
768 lock = nilfs_mdt_bgl_lock(inode, group);
769
770 j = i;
771 entry_start = rounddown(group_offset, epb);
772 do {
773 if (!nilfs_clear_bit_atomic(lock, group_offset,
774 bitmap)) {
775 nilfs_msg(inode->i_sb, KERN_WARNING,
776 "%s (ino=%lu): entry number %llu already freed",
777 __func__, inode->i_ino,
778 (unsigned long long)entry_nrs[j]);
779 } else {
780 n++;
781 }
782
783 j++;
784 if (j >= nitems || entry_nrs[j] < group_min_nr ||
785 entry_nrs[j] >= group_min_nr + epg) {
786 change_group = true;
787 } else {
788 group_offset = entry_nrs[j] - group_min_nr;
789 if (group_offset >= entry_start &&
790 group_offset < entry_start + epb) {
791 /* This entry is in the same block */
792 continue;
793 }
794 }
795
796 /* Test if the entry block is empty or not */
797 end = entry_start + epb;
798 pos = nilfs_find_next_bit(bitmap, end, entry_start);
799 if (pos >= end) {
800 last_nrs[nempties++] = entry_nrs[j - 1];
801 if (nempties >= ARRAY_SIZE(last_nrs))
802 break;
803 }
804
805 if (change_group)
806 break;
807
808 /* Go on to the next entry block */
809 entry_start = rounddown(group_offset, epb);
810 } while (true);
811
812 kunmap(bitmap_bh->b_page);
813 mark_buffer_dirty(bitmap_bh);
814 brelse(bitmap_bh);
815
816 for (k = 0; k < nempties; k++) {
817 ret = nilfs_palloc_delete_entry_block(inode,
818 last_nrs[k]);
819 if (ret && ret != -ENOENT)
820 nilfs_msg(inode->i_sb, KERN_WARNING,
821 "error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
822 ret, (unsigned long long)last_nrs[k],
823 inode->i_ino);
824 }
825
826 desc_kaddr = kmap_atomic(desc_bh->b_page);
827 desc = nilfs_palloc_block_get_group_desc(
828 inode, group, desc_bh, desc_kaddr);
829 nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
830 kunmap_atomic(desc_kaddr);
831 mark_buffer_dirty(desc_bh);
832 nilfs_mdt_mark_dirty(inode);
833 brelse(desc_bh);
834
835 if (nfree == nilfs_palloc_entries_per_group(inode)) {
836 ret = nilfs_palloc_delete_bitmap_block(inode, group);
837 if (ret && ret != -ENOENT)
838 nilfs_msg(inode->i_sb, KERN_WARNING,
839 "error %d deleting bitmap block of group=%lu, ino=%lu",
840 ret, group, inode->i_ino);
841 }
842 }
843 return 0;
844}
845
846void nilfs_palloc_setup_cache(struct inode *inode,
847 struct nilfs_palloc_cache *cache)
848{
849 NILFS_MDT(inode)->mi_palloc_cache = cache;
850 spin_lock_init(&cache->lock);
851}
852
853void nilfs_palloc_clear_cache(struct inode *inode)
854{
855 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
856
857 spin_lock(&cache->lock);
858 brelse(cache->prev_desc.bh);
859 brelse(cache->prev_bitmap.bh);
860 brelse(cache->prev_entry.bh);
861 cache->prev_desc.bh = NULL;
862 cache->prev_bitmap.bh = NULL;
863 cache->prev_entry.bh = NULL;
864 spin_unlock(&cache->lock);
865}
866
867void nilfs_palloc_destroy_cache(struct inode *inode)
868{
869 nilfs_palloc_clear_cache(inode);
870 NILFS_MDT(inode)->mi_palloc_cache = NULL;
871}
1// SPDX-License-Identifier: GPL-2.0+
2/*
3 * alloc.c - 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 get_bh(prev->bh);
210 *bhp = prev->bh;
211 spin_unlock(lock);
212 return 0;
213 }
214 spin_unlock(lock);
215
216 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
217 if (!ret) {
218 spin_lock(lock);
219 /*
220 * The following code must be safe for change of the
221 * cache contents during the get block call.
222 */
223 brelse(prev->bh);
224 get_bh(*bhp);
225 prev->bh = *bhp;
226 prev->blkoff = blkoff;
227 spin_unlock(lock);
228 }
229 return ret;
230}
231
232/**
233 * nilfs_palloc_delete_block - delete a block on the persistent allocator file
234 * @inode: inode of metadata file using this allocator
235 * @blkoff: block offset
236 * @prev: nilfs_bh_assoc struct of the last used buffer
237 * @lock: spin lock protecting @prev
238 */
239static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
240 struct nilfs_bh_assoc *prev,
241 spinlock_t *lock)
242{
243 spin_lock(lock);
244 if (prev->bh && blkoff == prev->blkoff) {
245 brelse(prev->bh);
246 prev->bh = NULL;
247 }
248 spin_unlock(lock);
249 return nilfs_mdt_delete_block(inode, blkoff);
250}
251
252/**
253 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
254 * @inode: inode of metadata file using this allocator
255 * @group: group number
256 * @create: create flag
257 * @bhp: pointer to store the resultant buffer head
258 */
259static int nilfs_palloc_get_desc_block(struct inode *inode,
260 unsigned long group,
261 int create, struct buffer_head **bhp)
262{
263 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
264
265 return nilfs_palloc_get_block(inode,
266 nilfs_palloc_desc_blkoff(inode, group),
267 create, nilfs_palloc_desc_block_init,
268 bhp, &cache->prev_desc, &cache->lock);
269}
270
271/**
272 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
273 * @inode: inode of metadata file using this allocator
274 * @group: group number
275 * @create: create flag
276 * @bhp: pointer to store the resultant buffer head
277 */
278static int nilfs_palloc_get_bitmap_block(struct inode *inode,
279 unsigned long group,
280 int create, struct buffer_head **bhp)
281{
282 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
283
284 return nilfs_palloc_get_block(inode,
285 nilfs_palloc_bitmap_blkoff(inode, group),
286 create, NULL, bhp,
287 &cache->prev_bitmap, &cache->lock);
288}
289
290/**
291 * nilfs_palloc_delete_bitmap_block - delete a bitmap block
292 * @inode: inode of metadata file using this allocator
293 * @group: group number
294 */
295static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
296 unsigned long group)
297{
298 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
299
300 return nilfs_palloc_delete_block(inode,
301 nilfs_palloc_bitmap_blkoff(inode,
302 group),
303 &cache->prev_bitmap, &cache->lock);
304}
305
306/**
307 * nilfs_palloc_get_entry_block - get buffer head of an entry block
308 * @inode: inode of metadata file using this allocator
309 * @nr: serial number of the entry (e.g. inode number)
310 * @create: create flag
311 * @bhp: pointer to store the resultant buffer head
312 */
313int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
314 int create, struct buffer_head **bhp)
315{
316 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
317
318 return nilfs_palloc_get_block(inode,
319 nilfs_palloc_entry_blkoff(inode, nr),
320 create, NULL, bhp,
321 &cache->prev_entry, &cache->lock);
322}
323
324/**
325 * nilfs_palloc_delete_entry_block - delete an entry block
326 * @inode: inode of metadata file using this allocator
327 * @nr: serial number of the entry
328 */
329static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
330{
331 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
332
333 return nilfs_palloc_delete_block(inode,
334 nilfs_palloc_entry_blkoff(inode, nr),
335 &cache->prev_entry, &cache->lock);
336}
337
338/**
339 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor
340 * @inode: inode of metadata file using this allocator
341 * @group: group number
342 * @bh: buffer head of the buffer storing the group descriptor block
343 * @kaddr: kernel address mapped for the page including the buffer
344 */
345static struct nilfs_palloc_group_desc *
346nilfs_palloc_block_get_group_desc(const struct inode *inode,
347 unsigned long group,
348 const struct buffer_head *bh, void *kaddr)
349{
350 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
351 group % nilfs_palloc_groups_per_desc_block(inode);
352}
353
354/**
355 * nilfs_palloc_block_get_entry - get kernel address of an entry
356 * @inode: inode of metadata file using this allocator
357 * @nr: serial number of the entry (e.g. inode number)
358 * @bh: buffer head of the buffer storing the entry block
359 * @kaddr: kernel address mapped for the page including the buffer
360 */
361void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
362 const struct buffer_head *bh, void *kaddr)
363{
364 unsigned long entry_offset, group_offset;
365
366 nilfs_palloc_group(inode, nr, &group_offset);
367 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
368
369 return kaddr + bh_offset(bh) +
370 entry_offset * NILFS_MDT(inode)->mi_entry_size;
371}
372
373/**
374 * nilfs_palloc_find_available_slot - find available slot in a group
375 * @bitmap: bitmap of the group
376 * @target: offset number of an entry in the group (start point)
377 * @bsize: size in bits
378 * @lock: spin lock protecting @bitmap
379 */
380static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
381 unsigned long target,
382 unsigned int bsize,
383 spinlock_t *lock)
384{
385 int pos, end = bsize;
386
387 if (likely(target < bsize)) {
388 pos = target;
389 do {
390 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
391 if (pos >= end)
392 break;
393 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
394 return pos;
395 } while (++pos < end);
396
397 end = target;
398 }
399
400 /* wrap around */
401 for (pos = 0; pos < end; pos++) {
402 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
403 if (pos >= end)
404 break;
405 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
406 return pos;
407 }
408
409 return -ENOSPC;
410}
411
412/**
413 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
414 * in a group descriptor block
415 * @inode: inode of metadata file using this allocator
416 * @curr: current group number
417 * @max: maximum number of groups
418 */
419static unsigned long
420nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
421 unsigned long curr, unsigned long max)
422{
423 return min_t(unsigned long,
424 nilfs_palloc_groups_per_desc_block(inode) -
425 curr % nilfs_palloc_groups_per_desc_block(inode),
426 max - curr + 1);
427}
428
429/**
430 * nilfs_palloc_count_desc_blocks - count descriptor blocks number
431 * @inode: inode of metadata file using this allocator
432 * @desc_blocks: descriptor blocks number [out]
433 */
434static int nilfs_palloc_count_desc_blocks(struct inode *inode,
435 unsigned long *desc_blocks)
436{
437 __u64 blknum;
438 int ret;
439
440 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
441 if (likely(!ret))
442 *desc_blocks = DIV_ROUND_UP(
443 (unsigned long)blknum,
444 NILFS_MDT(inode)->mi_blocks_per_desc_block);
445 return ret;
446}
447
448/**
449 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
450 * MDT file growing
451 * @inode: inode of metadata file using this allocator
452 * @desc_blocks: known current descriptor blocks count
453 */
454static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
455 unsigned long desc_blocks)
456{
457 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
458 nilfs_palloc_groups_count(inode);
459}
460
461/**
462 * nilfs_palloc_count_max_entries - count max number of entries that can be
463 * described by descriptor blocks count
464 * @inode: inode of metadata file using this allocator
465 * @nused: current number of used entries
466 * @nmaxp: max number of entries [out]
467 */
468int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
469{
470 unsigned long desc_blocks = 0;
471 u64 entries_per_desc_block, nmax;
472 int err;
473
474 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
475 if (unlikely(err))
476 return err;
477
478 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
479 nilfs_palloc_groups_per_desc_block(inode);
480 nmax = entries_per_desc_block * desc_blocks;
481
482 if (nused == nmax &&
483 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
484 nmax += entries_per_desc_block;
485
486 if (nused > nmax)
487 return -ERANGE;
488
489 *nmaxp = nmax;
490 return 0;
491}
492
493/**
494 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
495 * @inode: inode of metadata file using this allocator
496 * @req: nilfs_palloc_req structure exchanged for the allocation
497 */
498int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
499 struct nilfs_palloc_req *req)
500{
501 struct buffer_head *desc_bh, *bitmap_bh;
502 struct nilfs_palloc_group_desc *desc;
503 unsigned char *bitmap;
504 void *desc_kaddr, *bitmap_kaddr;
505 unsigned long group, maxgroup, ngroups;
506 unsigned long group_offset, maxgroup_offset;
507 unsigned long n, entries_per_group;
508 unsigned long i, j;
509 spinlock_t *lock;
510 int pos, ret;
511
512 ngroups = nilfs_palloc_groups_count(inode);
513 maxgroup = ngroups - 1;
514 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
515 entries_per_group = nilfs_palloc_entries_per_group(inode);
516
517 for (i = 0; i < ngroups; i += n) {
518 if (group >= ngroups) {
519 /* wrap around */
520 group = 0;
521 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
522 &maxgroup_offset) - 1;
523 }
524 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
525 if (ret < 0)
526 return ret;
527 desc_kaddr = kmap(desc_bh->b_page);
528 desc = nilfs_palloc_block_get_group_desc(
529 inode, group, desc_bh, desc_kaddr);
530 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
531 maxgroup);
532 for (j = 0; j < n; j++, desc++, group++) {
533 lock = nilfs_mdt_bgl_lock(inode, group);
534 if (nilfs_palloc_group_desc_nfrees(desc, lock) > 0) {
535 ret = nilfs_palloc_get_bitmap_block(
536 inode, group, 1, &bitmap_bh);
537 if (ret < 0)
538 goto out_desc;
539 bitmap_kaddr = kmap(bitmap_bh->b_page);
540 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
541 pos = nilfs_palloc_find_available_slot(
542 bitmap, group_offset,
543 entries_per_group, lock);
544 if (pos >= 0) {
545 /* found a free entry */
546 nilfs_palloc_group_desc_add_entries(
547 desc, lock, -1);
548 req->pr_entry_nr =
549 entries_per_group * group + pos;
550 kunmap(desc_bh->b_page);
551 kunmap(bitmap_bh->b_page);
552
553 req->pr_desc_bh = desc_bh;
554 req->pr_bitmap_bh = bitmap_bh;
555 return 0;
556 }
557 kunmap(bitmap_bh->b_page);
558 brelse(bitmap_bh);
559 }
560
561 group_offset = 0;
562 }
563
564 kunmap(desc_bh->b_page);
565 brelse(desc_bh);
566 }
567
568 /* no entries left */
569 return -ENOSPC;
570
571 out_desc:
572 kunmap(desc_bh->b_page);
573 brelse(desc_bh);
574 return ret;
575}
576
577/**
578 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
579 * @inode: inode of metadata file using this allocator
580 * @req: nilfs_palloc_req structure exchanged for the allocation
581 */
582void nilfs_palloc_commit_alloc_entry(struct inode *inode,
583 struct nilfs_palloc_req *req)
584{
585 mark_buffer_dirty(req->pr_bitmap_bh);
586 mark_buffer_dirty(req->pr_desc_bh);
587 nilfs_mdt_mark_dirty(inode);
588
589 brelse(req->pr_bitmap_bh);
590 brelse(req->pr_desc_bh);
591}
592
593/**
594 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
595 * @inode: inode of metadata file using this allocator
596 * @req: nilfs_palloc_req structure exchanged for the removal
597 */
598void nilfs_palloc_commit_free_entry(struct inode *inode,
599 struct nilfs_palloc_req *req)
600{
601 struct nilfs_palloc_group_desc *desc;
602 unsigned long group, group_offset;
603 unsigned char *bitmap;
604 void *desc_kaddr, *bitmap_kaddr;
605 spinlock_t *lock;
606
607 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
608 desc_kaddr = kmap(req->pr_desc_bh->b_page);
609 desc = nilfs_palloc_block_get_group_desc(inode, group,
610 req->pr_desc_bh, desc_kaddr);
611 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
612 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
613 lock = nilfs_mdt_bgl_lock(inode, group);
614
615 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
616 nilfs_msg(inode->i_sb, KERN_WARNING,
617 "%s (ino=%lu): entry number %llu already freed",
618 __func__, inode->i_ino,
619 (unsigned long long)req->pr_entry_nr);
620 else
621 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
622
623 kunmap(req->pr_bitmap_bh->b_page);
624 kunmap(req->pr_desc_bh->b_page);
625
626 mark_buffer_dirty(req->pr_desc_bh);
627 mark_buffer_dirty(req->pr_bitmap_bh);
628 nilfs_mdt_mark_dirty(inode);
629
630 brelse(req->pr_bitmap_bh);
631 brelse(req->pr_desc_bh);
632}
633
634/**
635 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
636 * @inode: inode of metadata file using this allocator
637 * @req: nilfs_palloc_req structure exchanged for the allocation
638 */
639void nilfs_palloc_abort_alloc_entry(struct inode *inode,
640 struct nilfs_palloc_req *req)
641{
642 struct nilfs_palloc_group_desc *desc;
643 void *desc_kaddr, *bitmap_kaddr;
644 unsigned char *bitmap;
645 unsigned long group, group_offset;
646 spinlock_t *lock;
647
648 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
649 desc_kaddr = kmap(req->pr_desc_bh->b_page);
650 desc = nilfs_palloc_block_get_group_desc(inode, group,
651 req->pr_desc_bh, desc_kaddr);
652 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
653 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
654 lock = nilfs_mdt_bgl_lock(inode, group);
655
656 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
657 nilfs_msg(inode->i_sb, KERN_WARNING,
658 "%s (ino=%lu): entry number %llu already freed",
659 __func__, inode->i_ino,
660 (unsigned long long)req->pr_entry_nr);
661 else
662 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
663
664 kunmap(req->pr_bitmap_bh->b_page);
665 kunmap(req->pr_desc_bh->b_page);
666
667 brelse(req->pr_bitmap_bh);
668 brelse(req->pr_desc_bh);
669
670 req->pr_entry_nr = 0;
671 req->pr_bitmap_bh = NULL;
672 req->pr_desc_bh = NULL;
673}
674
675/**
676 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
677 * @inode: inode of metadata file using this allocator
678 * @req: nilfs_palloc_req structure exchanged for the removal
679 */
680int nilfs_palloc_prepare_free_entry(struct inode *inode,
681 struct nilfs_palloc_req *req)
682{
683 struct buffer_head *desc_bh, *bitmap_bh;
684 unsigned long group, group_offset;
685 int ret;
686
687 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
688 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
689 if (ret < 0)
690 return ret;
691 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
692 if (ret < 0) {
693 brelse(desc_bh);
694 return ret;
695 }
696
697 req->pr_desc_bh = desc_bh;
698 req->pr_bitmap_bh = bitmap_bh;
699 return 0;
700}
701
702/**
703 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
704 * @inode: inode of metadata file using this allocator
705 * @req: nilfs_palloc_req structure exchanged for the removal
706 */
707void nilfs_palloc_abort_free_entry(struct inode *inode,
708 struct nilfs_palloc_req *req)
709{
710 brelse(req->pr_bitmap_bh);
711 brelse(req->pr_desc_bh);
712
713 req->pr_entry_nr = 0;
714 req->pr_bitmap_bh = NULL;
715 req->pr_desc_bh = NULL;
716}
717
718/**
719 * nilfs_palloc_freev - deallocate a set of persistent objects
720 * @inode: inode of metadata file using this allocator
721 * @entry_nrs: array of entry numbers to be deallocated
722 * @nitems: number of entries stored in @entry_nrs
723 */
724int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
725{
726 struct buffer_head *desc_bh, *bitmap_bh;
727 struct nilfs_palloc_group_desc *desc;
728 unsigned char *bitmap;
729 void *desc_kaddr, *bitmap_kaddr;
730 unsigned long group, group_offset;
731 __u64 group_min_nr, last_nrs[8];
732 const unsigned long epg = nilfs_palloc_entries_per_group(inode);
733 const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
734 unsigned int entry_start, end, pos;
735 spinlock_t *lock;
736 int i, j, k, ret;
737 u32 nfree;
738
739 for (i = 0; i < nitems; i = j) {
740 int change_group = false;
741 int nempties = 0, n = 0;
742
743 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
744 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
745 if (ret < 0)
746 return ret;
747 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
748 &bitmap_bh);
749 if (ret < 0) {
750 brelse(desc_bh);
751 return ret;
752 }
753
754 /* Get the first entry number of the group */
755 group_min_nr = (__u64)group * epg;
756
757 bitmap_kaddr = kmap(bitmap_bh->b_page);
758 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
759 lock = nilfs_mdt_bgl_lock(inode, group);
760
761 j = i;
762 entry_start = rounddown(group_offset, epb);
763 do {
764 if (!nilfs_clear_bit_atomic(lock, group_offset,
765 bitmap)) {
766 nilfs_msg(inode->i_sb, KERN_WARNING,
767 "%s (ino=%lu): entry number %llu already freed",
768 __func__, inode->i_ino,
769 (unsigned long long)entry_nrs[j]);
770 } else {
771 n++;
772 }
773
774 j++;
775 if (j >= nitems || entry_nrs[j] < group_min_nr ||
776 entry_nrs[j] >= group_min_nr + epg) {
777 change_group = true;
778 } else {
779 group_offset = entry_nrs[j] - group_min_nr;
780 if (group_offset >= entry_start &&
781 group_offset < entry_start + epb) {
782 /* This entry is in the same block */
783 continue;
784 }
785 }
786
787 /* Test if the entry block is empty or not */
788 end = entry_start + epb;
789 pos = nilfs_find_next_bit(bitmap, end, entry_start);
790 if (pos >= end) {
791 last_nrs[nempties++] = entry_nrs[j - 1];
792 if (nempties >= ARRAY_SIZE(last_nrs))
793 break;
794 }
795
796 if (change_group)
797 break;
798
799 /* Go on to the next entry block */
800 entry_start = rounddown(group_offset, epb);
801 } while (true);
802
803 kunmap(bitmap_bh->b_page);
804 mark_buffer_dirty(bitmap_bh);
805 brelse(bitmap_bh);
806
807 for (k = 0; k < nempties; k++) {
808 ret = nilfs_palloc_delete_entry_block(inode,
809 last_nrs[k]);
810 if (ret && ret != -ENOENT)
811 nilfs_msg(inode->i_sb, KERN_WARNING,
812 "error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
813 ret, (unsigned long long)last_nrs[k],
814 inode->i_ino);
815 }
816
817 desc_kaddr = kmap_atomic(desc_bh->b_page);
818 desc = nilfs_palloc_block_get_group_desc(
819 inode, group, desc_bh, desc_kaddr);
820 nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
821 kunmap_atomic(desc_kaddr);
822 mark_buffer_dirty(desc_bh);
823 nilfs_mdt_mark_dirty(inode);
824 brelse(desc_bh);
825
826 if (nfree == nilfs_palloc_entries_per_group(inode)) {
827 ret = nilfs_palloc_delete_bitmap_block(inode, group);
828 if (ret && ret != -ENOENT)
829 nilfs_msg(inode->i_sb, KERN_WARNING,
830 "error %d deleting bitmap block of group=%lu, ino=%lu",
831 ret, group, inode->i_ino);
832 }
833 }
834 return 0;
835}
836
837void nilfs_palloc_setup_cache(struct inode *inode,
838 struct nilfs_palloc_cache *cache)
839{
840 NILFS_MDT(inode)->mi_palloc_cache = cache;
841 spin_lock_init(&cache->lock);
842}
843
844void nilfs_palloc_clear_cache(struct inode *inode)
845{
846 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
847
848 spin_lock(&cache->lock);
849 brelse(cache->prev_desc.bh);
850 brelse(cache->prev_bitmap.bh);
851 brelse(cache->prev_entry.bh);
852 cache->prev_desc.bh = NULL;
853 cache->prev_bitmap.bh = NULL;
854 cache->prev_entry.bh = NULL;
855 spin_unlock(&cache->lock);
856}
857
858void nilfs_palloc_destroy_cache(struct inode *inode)
859{
860 nilfs_palloc_clear_cache(inode);
861 NILFS_MDT(inode)->mi_palloc_cache = NULL;
862}