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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 * 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 * @from: kernel address mapped for a chunk of the block
181 *
182 * This function does not yet support the case where block size > PAGE_SIZE.
183 */
184static void nilfs_palloc_desc_block_init(struct inode *inode,
185 struct buffer_head *bh, void *from)
186{
187 struct nilfs_palloc_group_desc *desc = from;
188 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
189 __le32 nfrees;
190
191 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
192 while (n-- > 0) {
193 desc->pg_nfrees = nfrees;
194 desc++;
195 }
196}
197
198static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
199 int create,
200 void (*init_block)(struct inode *,
201 struct buffer_head *,
202 void *),
203 struct buffer_head **bhp,
204 struct nilfs_bh_assoc *prev,
205 spinlock_t *lock)
206{
207 int ret;
208
209 spin_lock(lock);
210 if (prev->bh && blkoff == prev->blkoff &&
211 likely(buffer_uptodate(prev->bh))) {
212 get_bh(prev->bh);
213 *bhp = prev->bh;
214 spin_unlock(lock);
215 return 0;
216 }
217 spin_unlock(lock);
218
219 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
220 if (!ret) {
221 spin_lock(lock);
222 /*
223 * The following code must be safe for change of the
224 * cache contents during the get block call.
225 */
226 brelse(prev->bh);
227 get_bh(*bhp);
228 prev->bh = *bhp;
229 prev->blkoff = blkoff;
230 spin_unlock(lock);
231 }
232 return ret;
233}
234
235/**
236 * nilfs_palloc_delete_block - delete a block on the persistent allocator file
237 * @inode: inode of metadata file using this allocator
238 * @blkoff: block offset
239 * @prev: nilfs_bh_assoc struct of the last used buffer
240 * @lock: spin lock protecting @prev
241 */
242static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,
243 struct nilfs_bh_assoc *prev,
244 spinlock_t *lock)
245{
246 spin_lock(lock);
247 if (prev->bh && blkoff == prev->blkoff) {
248 brelse(prev->bh);
249 prev->bh = NULL;
250 }
251 spin_unlock(lock);
252 return nilfs_mdt_delete_block(inode, blkoff);
253}
254
255/**
256 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block
257 * @inode: inode of metadata file using this allocator
258 * @group: group number
259 * @create: create flag
260 * @bhp: pointer to store the resultant buffer head
261 */
262static int nilfs_palloc_get_desc_block(struct inode *inode,
263 unsigned long group,
264 int create, struct buffer_head **bhp)
265{
266 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
267
268 return nilfs_palloc_get_block(inode,
269 nilfs_palloc_desc_blkoff(inode, group),
270 create, nilfs_palloc_desc_block_init,
271 bhp, &cache->prev_desc, &cache->lock);
272}
273
274/**
275 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block
276 * @inode: inode of metadata file using this allocator
277 * @group: group number
278 * @create: create flag
279 * @bhp: pointer to store the resultant buffer head
280 */
281static int nilfs_palloc_get_bitmap_block(struct inode *inode,
282 unsigned long group,
283 int create, struct buffer_head **bhp)
284{
285 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
286
287 return nilfs_palloc_get_block(inode,
288 nilfs_palloc_bitmap_blkoff(inode, group),
289 create, NULL, bhp,
290 &cache->prev_bitmap, &cache->lock);
291}
292
293/**
294 * nilfs_palloc_delete_bitmap_block - delete a bitmap block
295 * @inode: inode of metadata file using this allocator
296 * @group: group number
297 */
298static int nilfs_palloc_delete_bitmap_block(struct inode *inode,
299 unsigned long group)
300{
301 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
302
303 return nilfs_palloc_delete_block(inode,
304 nilfs_palloc_bitmap_blkoff(inode,
305 group),
306 &cache->prev_bitmap, &cache->lock);
307}
308
309/**
310 * nilfs_palloc_get_entry_block - get buffer head of an entry block
311 * @inode: inode of metadata file using this allocator
312 * @nr: serial number of the entry (e.g. inode number)
313 * @create: create flag
314 * @bhp: pointer to store the resultant buffer head
315 */
316int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
317 int create, struct buffer_head **bhp)
318{
319 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
320
321 return nilfs_palloc_get_block(inode,
322 nilfs_palloc_entry_blkoff(inode, nr),
323 create, NULL, bhp,
324 &cache->prev_entry, &cache->lock);
325}
326
327/**
328 * nilfs_palloc_delete_entry_block - delete an entry block
329 * @inode: inode of metadata file using this allocator
330 * @nr: serial number of the entry
331 */
332static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)
333{
334 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
335
336 return nilfs_palloc_delete_block(inode,
337 nilfs_palloc_entry_blkoff(inode, nr),
338 &cache->prev_entry, &cache->lock);
339}
340
341/**
342 * nilfs_palloc_group_desc_offset - calculate the byte offset of a group
343 * descriptor in the folio containing it
344 * @inode: inode of metadata file using this allocator
345 * @group: group number
346 * @bh: buffer head of the group descriptor block
347 *
348 * Return: Byte offset in the folio of the group descriptor for @group.
349 */
350static size_t nilfs_palloc_group_desc_offset(const struct inode *inode,
351 unsigned long group,
352 const struct buffer_head *bh)
353{
354 return offset_in_folio(bh->b_folio, bh->b_data) +
355 sizeof(struct nilfs_palloc_group_desc) *
356 (group % nilfs_palloc_groups_per_desc_block(inode));
357}
358
359/**
360 * nilfs_palloc_bitmap_offset - calculate the byte offset of a bitmap block
361 * in the folio containing it
362 * @bh: buffer head of the bitmap block
363 *
364 * Return: Byte offset in the folio of the bitmap block for @bh.
365 */
366static size_t nilfs_palloc_bitmap_offset(const struct buffer_head *bh)
367{
368 return offset_in_folio(bh->b_folio, bh->b_data);
369}
370
371/**
372 * nilfs_palloc_entry_offset - calculate the byte offset of an entry in the
373 * folio containing it
374 * @inode: inode of metadata file using this allocator
375 * @nr: serial number of the entry (e.g. inode number)
376 * @bh: buffer head of the entry block
377 *
378 * Return: Byte offset in the folio of the entry @nr.
379 */
380size_t nilfs_palloc_entry_offset(const struct inode *inode, __u64 nr,
381 const struct buffer_head *bh)
382{
383 unsigned long entry_index_in_group, entry_index_in_block;
384
385 nilfs_palloc_group(inode, nr, &entry_index_in_group);
386 entry_index_in_block = entry_index_in_group %
387 NILFS_MDT(inode)->mi_entries_per_block;
388
389 return offset_in_folio(bh->b_folio, bh->b_data) +
390 entry_index_in_block * NILFS_MDT(inode)->mi_entry_size;
391}
392
393/**
394 * nilfs_palloc_find_available_slot - find available slot in a group
395 * @bitmap: bitmap of the group
396 * @target: offset number of an entry in the group (start point)
397 * @bsize: size in bits
398 * @lock: spin lock protecting @bitmap
399 * @wrap: whether to wrap around
400 */
401static int nilfs_palloc_find_available_slot(unsigned char *bitmap,
402 unsigned long target,
403 unsigned int bsize,
404 spinlock_t *lock, bool wrap)
405{
406 int pos, end = bsize;
407
408 if (likely(target < bsize)) {
409 pos = target;
410 do {
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 } while (++pos < end);
417
418 end = target;
419 }
420 if (!wrap)
421 return -ENOSPC;
422
423 /* wrap around */
424 for (pos = 0; pos < end; pos++) {
425 pos = nilfs_find_next_zero_bit(bitmap, end, pos);
426 if (pos >= end)
427 break;
428 if (!nilfs_set_bit_atomic(lock, pos, bitmap))
429 return pos;
430 }
431
432 return -ENOSPC;
433}
434
435/**
436 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups
437 * in a group descriptor block
438 * @inode: inode of metadata file using this allocator
439 * @curr: current group number
440 * @max: maximum number of groups
441 */
442static unsigned long
443nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
444 unsigned long curr, unsigned long max)
445{
446 return min_t(unsigned long,
447 nilfs_palloc_groups_per_desc_block(inode) -
448 curr % nilfs_palloc_groups_per_desc_block(inode),
449 max - curr + 1);
450}
451
452/**
453 * nilfs_palloc_count_desc_blocks - count descriptor blocks number
454 * @inode: inode of metadata file using this allocator
455 * @desc_blocks: descriptor blocks number [out]
456 */
457static int nilfs_palloc_count_desc_blocks(struct inode *inode,
458 unsigned long *desc_blocks)
459{
460 __u64 blknum;
461 int ret;
462
463 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);
464 if (likely(!ret))
465 *desc_blocks = DIV_ROUND_UP(
466 (unsigned long)blknum,
467 NILFS_MDT(inode)->mi_blocks_per_desc_block);
468 return ret;
469}
470
471/**
472 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for
473 * MDT file growing
474 * @inode: inode of metadata file using this allocator
475 * @desc_blocks: known current descriptor blocks count
476 */
477static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,
478 unsigned long desc_blocks)
479{
480 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <
481 nilfs_palloc_groups_count(inode);
482}
483
484/**
485 * nilfs_palloc_count_max_entries - count max number of entries that can be
486 * described by descriptor blocks count
487 * @inode: inode of metadata file using this allocator
488 * @nused: current number of used entries
489 * @nmaxp: max number of entries [out]
490 */
491int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)
492{
493 unsigned long desc_blocks = 0;
494 u64 entries_per_desc_block, nmax;
495 int err;
496
497 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);
498 if (unlikely(err))
499 return err;
500
501 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *
502 nilfs_palloc_groups_per_desc_block(inode);
503 nmax = entries_per_desc_block * desc_blocks;
504
505 if (nused == nmax &&
506 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))
507 nmax += entries_per_desc_block;
508
509 if (nused > nmax)
510 return -ERANGE;
511
512 *nmaxp = nmax;
513 return 0;
514}
515
516/**
517 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object
518 * @inode: inode of metadata file using this allocator
519 * @req: nilfs_palloc_req structure exchanged for the allocation
520 * @wrap: whether to wrap around
521 */
522int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
523 struct nilfs_palloc_req *req, bool wrap)
524{
525 struct buffer_head *desc_bh, *bitmap_bh;
526 struct nilfs_palloc_group_desc *desc;
527 unsigned char *bitmap;
528 size_t doff, boff;
529 unsigned long group, maxgroup, ngroups;
530 unsigned long group_offset, maxgroup_offset;
531 unsigned long n, entries_per_group;
532 unsigned long i, j;
533 spinlock_t *lock;
534 int pos, ret;
535
536 ngroups = nilfs_palloc_groups_count(inode);
537 maxgroup = ngroups - 1;
538 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
539 entries_per_group = nilfs_palloc_entries_per_group(inode);
540
541 for (i = 0; i < ngroups; i += n) {
542 if (group >= ngroups && wrap) {
543 /* wrap around */
544 group = 0;
545 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
546 &maxgroup_offset) - 1;
547 }
548 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
549 if (ret < 0)
550 return ret;
551
552 doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh);
553 desc = kmap_local_folio(desc_bh->b_folio, doff);
554 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
555 maxgroup);
556 for (j = 0; j < n; j++, group++, group_offset = 0) {
557 lock = nilfs_mdt_bgl_lock(inode, group);
558 if (nilfs_palloc_group_desc_nfrees(&desc[j], lock) == 0)
559 continue;
560
561 kunmap_local(desc);
562 ret = nilfs_palloc_get_bitmap_block(inode, group, 1,
563 &bitmap_bh);
564 if (unlikely(ret < 0)) {
565 brelse(desc_bh);
566 return ret;
567 }
568
569 /*
570 * Re-kmap the folio containing the first (and
571 * subsequent) group descriptors.
572 */
573 desc = kmap_local_folio(desc_bh->b_folio, doff);
574
575 boff = nilfs_palloc_bitmap_offset(bitmap_bh);
576 bitmap = kmap_local_folio(bitmap_bh->b_folio, boff);
577 pos = nilfs_palloc_find_available_slot(
578 bitmap, group_offset, entries_per_group, lock,
579 wrap);
580 /*
581 * Since the search for a free slot in the second and
582 * subsequent bitmap blocks always starts from the
583 * beginning, the wrap flag only has an effect on the
584 * first search.
585 */
586 kunmap_local(bitmap);
587 if (pos >= 0)
588 goto found;
589
590 brelse(bitmap_bh);
591 }
592
593 kunmap_local(desc);
594 brelse(desc_bh);
595 }
596
597 /* no entries left */
598 return -ENOSPC;
599
600found:
601 /* found a free entry */
602 nilfs_palloc_group_desc_add_entries(&desc[j], lock, -1);
603 req->pr_entry_nr = entries_per_group * group + pos;
604 kunmap_local(desc);
605
606 req->pr_desc_bh = desc_bh;
607 req->pr_bitmap_bh = bitmap_bh;
608 return 0;
609}
610
611/**
612 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object
613 * @inode: inode of metadata file using this allocator
614 * @req: nilfs_palloc_req structure exchanged for the allocation
615 */
616void nilfs_palloc_commit_alloc_entry(struct inode *inode,
617 struct nilfs_palloc_req *req)
618{
619 mark_buffer_dirty(req->pr_bitmap_bh);
620 mark_buffer_dirty(req->pr_desc_bh);
621 nilfs_mdt_mark_dirty(inode);
622
623 brelse(req->pr_bitmap_bh);
624 brelse(req->pr_desc_bh);
625}
626
627/**
628 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object
629 * @inode: inode of metadata file using this allocator
630 * @req: nilfs_palloc_req structure exchanged for the removal
631 */
632void nilfs_palloc_commit_free_entry(struct inode *inode,
633 struct nilfs_palloc_req *req)
634{
635 unsigned long group, group_offset;
636 size_t doff, boff;
637 struct nilfs_palloc_group_desc *desc;
638 unsigned char *bitmap;
639 spinlock_t *lock;
640
641 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
642 doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh);
643 desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff);
644
645 boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh);
646 bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff);
647 lock = nilfs_mdt_bgl_lock(inode, group);
648
649 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
650 nilfs_warn(inode->i_sb,
651 "%s (ino=%lu): entry number %llu already freed",
652 __func__, inode->i_ino,
653 (unsigned long long)req->pr_entry_nr);
654 else
655 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
656
657 kunmap_local(bitmap);
658 kunmap_local(desc);
659
660 mark_buffer_dirty(req->pr_desc_bh);
661 mark_buffer_dirty(req->pr_bitmap_bh);
662 nilfs_mdt_mark_dirty(inode);
663
664 brelse(req->pr_bitmap_bh);
665 brelse(req->pr_desc_bh);
666}
667
668/**
669 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object
670 * @inode: inode of metadata file using this allocator
671 * @req: nilfs_palloc_req structure exchanged for the allocation
672 */
673void nilfs_palloc_abort_alloc_entry(struct inode *inode,
674 struct nilfs_palloc_req *req)
675{
676 struct nilfs_palloc_group_desc *desc;
677 size_t doff, boff;
678 unsigned char *bitmap;
679 unsigned long group, group_offset;
680 spinlock_t *lock;
681
682 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
683 doff = nilfs_palloc_group_desc_offset(inode, group, req->pr_desc_bh);
684 desc = kmap_local_folio(req->pr_desc_bh->b_folio, doff);
685
686 boff = nilfs_palloc_bitmap_offset(req->pr_bitmap_bh);
687 bitmap = kmap_local_folio(req->pr_bitmap_bh->b_folio, boff);
688 lock = nilfs_mdt_bgl_lock(inode, group);
689
690 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))
691 nilfs_warn(inode->i_sb,
692 "%s (ino=%lu): entry number %llu already freed",
693 __func__, inode->i_ino,
694 (unsigned long long)req->pr_entry_nr);
695 else
696 nilfs_palloc_group_desc_add_entries(desc, lock, 1);
697
698 kunmap_local(bitmap);
699 kunmap_local(desc);
700
701 brelse(req->pr_bitmap_bh);
702 brelse(req->pr_desc_bh);
703
704 req->pr_entry_nr = 0;
705 req->pr_bitmap_bh = NULL;
706 req->pr_desc_bh = NULL;
707}
708
709/**
710 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object
711 * @inode: inode of metadata file using this allocator
712 * @req: nilfs_palloc_req structure exchanged for the removal
713 */
714int nilfs_palloc_prepare_free_entry(struct inode *inode,
715 struct nilfs_palloc_req *req)
716{
717 struct buffer_head *desc_bh, *bitmap_bh;
718 unsigned long group, group_offset;
719 int ret;
720
721 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
722 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
723 if (ret < 0)
724 return ret;
725 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
726 if (ret < 0) {
727 brelse(desc_bh);
728 return ret;
729 }
730
731 req->pr_desc_bh = desc_bh;
732 req->pr_bitmap_bh = bitmap_bh;
733 return 0;
734}
735
736/**
737 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object
738 * @inode: inode of metadata file using this allocator
739 * @req: nilfs_palloc_req structure exchanged for the removal
740 */
741void nilfs_palloc_abort_free_entry(struct inode *inode,
742 struct nilfs_palloc_req *req)
743{
744 brelse(req->pr_bitmap_bh);
745 brelse(req->pr_desc_bh);
746
747 req->pr_entry_nr = 0;
748 req->pr_bitmap_bh = NULL;
749 req->pr_desc_bh = NULL;
750}
751
752/**
753 * nilfs_palloc_freev - deallocate a set of persistent objects
754 * @inode: inode of metadata file using this allocator
755 * @entry_nrs: array of entry numbers to be deallocated
756 * @nitems: number of entries stored in @entry_nrs
757 */
758int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
759{
760 struct buffer_head *desc_bh, *bitmap_bh;
761 struct nilfs_palloc_group_desc *desc;
762 unsigned char *bitmap;
763 size_t doff, boff;
764 unsigned long group, group_offset;
765 __u64 group_min_nr, last_nrs[8];
766 const unsigned long epg = nilfs_palloc_entries_per_group(inode);
767 const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;
768 unsigned int entry_start, end, pos;
769 spinlock_t *lock;
770 int i, j, k, ret;
771 u32 nfree;
772
773 for (i = 0; i < nitems; i = j) {
774 int change_group = false;
775 int nempties = 0, n = 0;
776
777 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
778 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
779 if (ret < 0)
780 return ret;
781 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
782 &bitmap_bh);
783 if (ret < 0) {
784 brelse(desc_bh);
785 return ret;
786 }
787
788 /* Get the first entry number of the group */
789 group_min_nr = (__u64)group * epg;
790
791 boff = nilfs_palloc_bitmap_offset(bitmap_bh);
792 bitmap = kmap_local_folio(bitmap_bh->b_folio, boff);
793 lock = nilfs_mdt_bgl_lock(inode, group);
794
795 j = i;
796 entry_start = rounddown(group_offset, epb);
797 do {
798 if (!nilfs_clear_bit_atomic(lock, group_offset,
799 bitmap)) {
800 nilfs_warn(inode->i_sb,
801 "%s (ino=%lu): entry number %llu already freed",
802 __func__, inode->i_ino,
803 (unsigned long long)entry_nrs[j]);
804 } else {
805 n++;
806 }
807
808 j++;
809 if (j >= nitems || entry_nrs[j] < group_min_nr ||
810 entry_nrs[j] >= group_min_nr + epg) {
811 change_group = true;
812 } else {
813 group_offset = entry_nrs[j] - group_min_nr;
814 if (group_offset >= entry_start &&
815 group_offset < entry_start + epb) {
816 /* This entry is in the same block */
817 continue;
818 }
819 }
820
821 /* Test if the entry block is empty or not */
822 end = entry_start + epb;
823 pos = nilfs_find_next_bit(bitmap, end, entry_start);
824 if (pos >= end) {
825 last_nrs[nempties++] = entry_nrs[j - 1];
826 if (nempties >= ARRAY_SIZE(last_nrs))
827 break;
828 }
829
830 if (change_group)
831 break;
832
833 /* Go on to the next entry block */
834 entry_start = rounddown(group_offset, epb);
835 } while (true);
836
837 kunmap_local(bitmap);
838 mark_buffer_dirty(bitmap_bh);
839 brelse(bitmap_bh);
840
841 for (k = 0; k < nempties; k++) {
842 ret = nilfs_palloc_delete_entry_block(inode,
843 last_nrs[k]);
844 if (ret && ret != -ENOENT)
845 nilfs_warn(inode->i_sb,
846 "error %d deleting block that object (entry=%llu, ino=%lu) belongs to",
847 ret, (unsigned long long)last_nrs[k],
848 inode->i_ino);
849 }
850
851 doff = nilfs_palloc_group_desc_offset(inode, group, desc_bh);
852 desc = kmap_local_folio(desc_bh->b_folio, doff);
853 nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);
854 kunmap_local(desc);
855 mark_buffer_dirty(desc_bh);
856 nilfs_mdt_mark_dirty(inode);
857 brelse(desc_bh);
858
859 if (nfree == nilfs_palloc_entries_per_group(inode)) {
860 ret = nilfs_palloc_delete_bitmap_block(inode, group);
861 if (ret && ret != -ENOENT)
862 nilfs_warn(inode->i_sb,
863 "error %d deleting bitmap block of group=%lu, ino=%lu",
864 ret, group, inode->i_ino);
865 }
866 }
867 return 0;
868}
869
870void nilfs_palloc_setup_cache(struct inode *inode,
871 struct nilfs_palloc_cache *cache)
872{
873 NILFS_MDT(inode)->mi_palloc_cache = cache;
874 spin_lock_init(&cache->lock);
875}
876
877void nilfs_palloc_clear_cache(struct inode *inode)
878{
879 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
880
881 spin_lock(&cache->lock);
882 brelse(cache->prev_desc.bh);
883 brelse(cache->prev_bitmap.bh);
884 brelse(cache->prev_entry.bh);
885 cache->prev_desc.bh = NULL;
886 cache->prev_bitmap.bh = NULL;
887 cache->prev_entry.bh = NULL;
888 spin_unlock(&cache->lock);
889}
890
891void nilfs_palloc_destroy_cache(struct inode *inode)
892{
893 nilfs_palloc_clear_cache(inode);
894 NILFS_MDT(inode)->mi_palloc_cache = NULL;
895}