2 * alloc.c - NILFS dat/inode allocator
4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
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.
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.
16 * You should have received a copy of the GNU General Public License
17 * along with this program; if not, write to the Free Software
18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
20 * Original code was written by Koji Sato <koji@osrg.net>.
21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
22 * Amagai Yoshiji <amagai@osrg.net>.
25 #include <linux/types.h>
26 #include <linux/buffer_head.h>
28 #include <linux/bitops.h>
33 static inline unsigned long
34 nilfs_palloc_groups_per_desc_block(const struct inode *inode)
36 return (1UL << inode->i_blkbits) /
37 sizeof(struct nilfs_palloc_group_desc);
40 static inline unsigned long
41 nilfs_palloc_groups_count(const struct inode *inode)
43 return 1UL << (BITS_PER_LONG - (inode->i_blkbits + 3 /* log2(8) */));
46 int nilfs_palloc_init_blockgroup(struct inode *inode, unsigned entry_size)
48 struct nilfs_mdt_info *mi = NILFS_MDT(inode);
50 mi->mi_bgl = kmalloc(sizeof(*mi->mi_bgl), GFP_NOFS);
54 bgl_lock_init(mi->mi_bgl);
56 nilfs_mdt_set_entry_size(inode, entry_size, 0);
58 mi->mi_blocks_per_group =
59 DIV_ROUND_UP(nilfs_palloc_entries_per_group(inode),
60 mi->mi_entries_per_block) + 1;
61 /* Number of blocks in a group including entry blocks and
63 mi->mi_blocks_per_desc_block =
64 nilfs_palloc_groups_per_desc_block(inode) *
65 mi->mi_blocks_per_group + 1;
66 /* Number of blocks per descriptor including the
71 static unsigned long nilfs_palloc_group(const struct inode *inode, __u64 nr,
72 unsigned long *offset)
76 *offset = do_div(group, nilfs_palloc_entries_per_group(inode));
81 nilfs_palloc_desc_blkoff(const struct inode *inode, unsigned long group)
83 unsigned long desc_block =
84 group / nilfs_palloc_groups_per_desc_block(inode);
85 return desc_block * NILFS_MDT(inode)->mi_blocks_per_desc_block;
89 nilfs_palloc_bitmap_blkoff(const struct inode *inode, unsigned long group)
91 unsigned long desc_offset =
92 group % nilfs_palloc_groups_per_desc_block(inode);
93 return nilfs_palloc_desc_blkoff(inode, group) + 1 +
94 desc_offset * NILFS_MDT(inode)->mi_blocks_per_group;
98 nilfs_palloc_group_desc_nfrees(struct inode *inode, unsigned long group,
99 const struct nilfs_palloc_group_desc *desc)
103 spin_lock(nilfs_mdt_bgl_lock(inode, group));
104 nfree = le32_to_cpu(desc->pg_nfrees);
105 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
110 nilfs_palloc_group_desc_add_entries(struct inode *inode,
112 struct nilfs_palloc_group_desc *desc,
115 spin_lock(nilfs_mdt_bgl_lock(inode, group));
116 le32_add_cpu(&desc->pg_nfrees, n);
117 spin_unlock(nilfs_mdt_bgl_lock(inode, group));
121 nilfs_palloc_entry_blkoff(const struct inode *inode, __u64 nr)
123 unsigned long group, group_offset;
125 group = nilfs_palloc_group(inode, nr, &group_offset);
127 return nilfs_palloc_bitmap_blkoff(inode, group) + 1 +
128 group_offset / NILFS_MDT(inode)->mi_entries_per_block;
131 static void nilfs_palloc_desc_block_init(struct inode *inode,
132 struct buffer_head *bh, void *kaddr)
134 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);
135 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);
138 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));
140 desc->pg_nfrees = nfrees;
145 static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,
147 void (*init_block)(struct inode *,
148 struct buffer_head *,
150 struct buffer_head **bhp,
151 struct nilfs_bh_assoc *prev,
157 if (prev->bh && blkoff == prev->blkoff) {
165 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);
169 * The following code must be safe for change of the
170 * cache contents during the get block call.
175 prev->blkoff = blkoff;
181 static int nilfs_palloc_get_desc_block(struct inode *inode,
183 int create, struct buffer_head **bhp)
185 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
187 return nilfs_palloc_get_block(inode,
188 nilfs_palloc_desc_blkoff(inode, group),
189 create, nilfs_palloc_desc_block_init,
190 bhp, &cache->prev_desc, &cache->lock);
193 static int nilfs_palloc_get_bitmap_block(struct inode *inode,
195 int create, struct buffer_head **bhp)
197 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
199 return nilfs_palloc_get_block(inode,
200 nilfs_palloc_bitmap_blkoff(inode, group),
202 &cache->prev_bitmap, &cache->lock);
205 int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,
206 int create, struct buffer_head **bhp)
208 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
210 return nilfs_palloc_get_block(inode,
211 nilfs_palloc_entry_blkoff(inode, nr),
213 &cache->prev_entry, &cache->lock);
216 static struct nilfs_palloc_group_desc *
217 nilfs_palloc_block_get_group_desc(const struct inode *inode,
219 const struct buffer_head *bh, void *kaddr)
221 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +
222 group % nilfs_palloc_groups_per_desc_block(inode);
225 void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,
226 const struct buffer_head *bh, void *kaddr)
228 unsigned long entry_offset, group_offset;
230 nilfs_palloc_group(inode, nr, &group_offset);
231 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;
233 return kaddr + bh_offset(bh) +
234 entry_offset * NILFS_MDT(inode)->mi_entry_size;
237 static int nilfs_palloc_find_available_slot(struct inode *inode,
239 unsigned long target,
240 unsigned char *bitmap,
241 int bsize) /* size in bits */
243 int curr, pos, end, i;
246 end = (target + BITS_PER_LONG - 1) & ~(BITS_PER_LONG - 1);
249 pos = nilfs_find_next_zero_bit(bitmap, end, target);
251 !nilfs_set_bit_atomic(
252 nilfs_mdt_bgl_lock(inode, group), pos, bitmap))
257 for (i = 0, curr = end;
259 i += BITS_PER_LONG, curr += BITS_PER_LONG) {
263 while (*((unsigned long *)bitmap + curr / BITS_PER_LONG)
265 end = curr + BITS_PER_LONG;
268 pos = nilfs_find_next_zero_bit(bitmap, end, curr);
270 !nilfs_set_bit_atomic(
271 nilfs_mdt_bgl_lock(inode, group), pos,
280 nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,
281 unsigned long curr, unsigned long max)
283 return min_t(unsigned long,
284 nilfs_palloc_groups_per_desc_block(inode) -
285 curr % nilfs_palloc_groups_per_desc_block(inode),
289 int nilfs_palloc_prepare_alloc_entry(struct inode *inode,
290 struct nilfs_palloc_req *req)
292 struct buffer_head *desc_bh, *bitmap_bh;
293 struct nilfs_palloc_group_desc *desc;
294 unsigned char *bitmap;
295 void *desc_kaddr, *bitmap_kaddr;
296 unsigned long group, maxgroup, ngroups;
297 unsigned long group_offset, maxgroup_offset;
298 unsigned long n, entries_per_group, groups_per_desc_block;
302 ngroups = nilfs_palloc_groups_count(inode);
303 maxgroup = ngroups - 1;
304 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
305 entries_per_group = nilfs_palloc_entries_per_group(inode);
306 groups_per_desc_block = nilfs_palloc_groups_per_desc_block(inode);
308 for (i = 0; i < ngroups; i += n) {
309 if (group >= ngroups) {
312 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,
313 &maxgroup_offset) - 1;
315 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
318 desc_kaddr = kmap(desc_bh->b_page);
319 desc = nilfs_palloc_block_get_group_desc(
320 inode, group, desc_bh, desc_kaddr);
321 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,
323 for (j = 0; j < n; j++, desc++, group++) {
324 if (nilfs_palloc_group_desc_nfrees(inode, group, desc)
326 ret = nilfs_palloc_get_bitmap_block(
327 inode, group, 1, &bitmap_bh);
330 bitmap_kaddr = kmap(bitmap_bh->b_page);
331 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
332 pos = nilfs_palloc_find_available_slot(
333 inode, group, group_offset, bitmap,
336 /* found a free entry */
337 nilfs_palloc_group_desc_add_entries(
338 inode, group, desc, -1);
340 entries_per_group * group + pos;
341 kunmap(desc_bh->b_page);
342 kunmap(bitmap_bh->b_page);
344 req->pr_desc_bh = desc_bh;
345 req->pr_bitmap_bh = bitmap_bh;
348 kunmap(bitmap_bh->b_page);
355 kunmap(desc_bh->b_page);
359 /* no entries left */
363 kunmap(desc_bh->b_page);
368 void nilfs_palloc_commit_alloc_entry(struct inode *inode,
369 struct nilfs_palloc_req *req)
371 nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
372 nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
373 nilfs_mdt_mark_dirty(inode);
375 brelse(req->pr_bitmap_bh);
376 brelse(req->pr_desc_bh);
379 void nilfs_palloc_commit_free_entry(struct inode *inode,
380 struct nilfs_palloc_req *req)
382 struct nilfs_palloc_group_desc *desc;
383 unsigned long group, group_offset;
384 unsigned char *bitmap;
385 void *desc_kaddr, *bitmap_kaddr;
387 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
388 desc_kaddr = kmap(req->pr_desc_bh->b_page);
389 desc = nilfs_palloc_block_get_group_desc(inode, group,
390 req->pr_desc_bh, desc_kaddr);
391 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
392 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
394 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
395 group_offset, bitmap))
396 printk(KERN_WARNING "%s: entry number %llu already freed\n",
397 __func__, (unsigned long long)req->pr_entry_nr);
399 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
401 kunmap(req->pr_bitmap_bh->b_page);
402 kunmap(req->pr_desc_bh->b_page);
404 nilfs_mdt_mark_buffer_dirty(req->pr_desc_bh);
405 nilfs_mdt_mark_buffer_dirty(req->pr_bitmap_bh);
406 nilfs_mdt_mark_dirty(inode);
408 brelse(req->pr_bitmap_bh);
409 brelse(req->pr_desc_bh);
412 void nilfs_palloc_abort_alloc_entry(struct inode *inode,
413 struct nilfs_palloc_req *req)
415 struct nilfs_palloc_group_desc *desc;
416 void *desc_kaddr, *bitmap_kaddr;
417 unsigned char *bitmap;
418 unsigned long group, group_offset;
420 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
421 desc_kaddr = kmap(req->pr_desc_bh->b_page);
422 desc = nilfs_palloc_block_get_group_desc(inode, group,
423 req->pr_desc_bh, desc_kaddr);
424 bitmap_kaddr = kmap(req->pr_bitmap_bh->b_page);
425 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);
426 if (!nilfs_clear_bit_atomic(nilfs_mdt_bgl_lock(inode, group),
427 group_offset, bitmap))
428 printk(KERN_WARNING "%s: entry numer %llu already freed\n",
429 __func__, (unsigned long long)req->pr_entry_nr);
431 nilfs_palloc_group_desc_add_entries(inode, group, desc, 1);
433 kunmap(req->pr_bitmap_bh->b_page);
434 kunmap(req->pr_desc_bh->b_page);
436 brelse(req->pr_bitmap_bh);
437 brelse(req->pr_desc_bh);
439 req->pr_entry_nr = 0;
440 req->pr_bitmap_bh = NULL;
441 req->pr_desc_bh = NULL;
444 int nilfs_palloc_prepare_free_entry(struct inode *inode,
445 struct nilfs_palloc_req *req)
447 struct buffer_head *desc_bh, *bitmap_bh;
448 unsigned long group, group_offset;
451 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);
452 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);
455 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);
461 req->pr_desc_bh = desc_bh;
462 req->pr_bitmap_bh = bitmap_bh;
466 void nilfs_palloc_abort_free_entry(struct inode *inode,
467 struct nilfs_palloc_req *req)
469 brelse(req->pr_bitmap_bh);
470 brelse(req->pr_desc_bh);
472 req->pr_entry_nr = 0;
473 req->pr_bitmap_bh = NULL;
474 req->pr_desc_bh = NULL;
478 nilfs_palloc_group_is_in(struct inode *inode, unsigned long group, __u64 nr)
482 first = group * nilfs_palloc_entries_per_group(inode);
483 last = first + nilfs_palloc_entries_per_group(inode) - 1;
484 return (nr >= first) && (nr <= last);
487 int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)
489 struct buffer_head *desc_bh, *bitmap_bh;
490 struct nilfs_palloc_group_desc *desc;
491 unsigned char *bitmap;
492 void *desc_kaddr, *bitmap_kaddr;
493 unsigned long group, group_offset;
496 for (i = 0; i < nitems; i += n) {
497 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);
498 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);
501 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,
507 desc_kaddr = kmap(desc_bh->b_page);
508 desc = nilfs_palloc_block_get_group_desc(
509 inode, group, desc_bh, desc_kaddr);
510 bitmap_kaddr = kmap(bitmap_bh->b_page);
511 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);
513 (j < nitems) && nilfs_palloc_group_is_in(inode, group,
516 nilfs_palloc_group(inode, entry_nrs[j], &group_offset);
517 if (!nilfs_clear_bit_atomic(
518 nilfs_mdt_bgl_lock(inode, group),
519 group_offset, bitmap)) {
521 "%s: entry number %llu already freed\n",
523 (unsigned long long)entry_nrs[j]);
526 nilfs_palloc_group_desc_add_entries(inode, group, desc, n);
528 kunmap(bitmap_bh->b_page);
529 kunmap(desc_bh->b_page);
531 nilfs_mdt_mark_buffer_dirty(desc_bh);
532 nilfs_mdt_mark_buffer_dirty(bitmap_bh);
533 nilfs_mdt_mark_dirty(inode);
541 void nilfs_palloc_setup_cache(struct inode *inode,
542 struct nilfs_palloc_cache *cache)
544 NILFS_MDT(inode)->mi_palloc_cache = cache;
545 spin_lock_init(&cache->lock);
548 void nilfs_palloc_clear_cache(struct inode *inode)
550 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;
552 spin_lock(&cache->lock);
553 brelse(cache->prev_desc.bh);
554 brelse(cache->prev_bitmap.bh);
555 brelse(cache->prev_entry.bh);
556 cache->prev_desc.bh = NULL;
557 cache->prev_bitmap.bh = NULL;
558 cache->prev_entry.bh = NULL;
559 spin_unlock(&cache->lock);
562 void nilfs_palloc_destroy_cache(struct inode *inode)
564 nilfs_palloc_clear_cache(inode);
565 NILFS_MDT(inode)->mi_palloc_cache = NULL;