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1// SPDX-License-Identifier: GPL-2.0+2/*3 * NILFS dat/inode allocator4 *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 group22 * descriptor block can maintain23 * @inode: inode of metadata file using this allocator24 */25static inline unsigned long26nilfs_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 groups34 * @inode: inode of metadata file using this allocator35 */36static inline unsigned long37nilfs_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 allocator44 * @inode: inode of metadata file using this allocator45 * @entry_size: size of the persistent object46 */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 blocks64 * and a bitmap block65 */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 the71 * descriptor block72 */73 return 0;74}75 76/**77 * nilfs_palloc_group - get group number and offset from an entry number78 * @inode: inode of metadata file using this allocator79 * @nr: serial number of the entry (e.g. inode number)80 * @offset: pointer to store offset number in the group81 */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 block93 * @inode: inode of metadata file using this allocator94 * @group: group number95 *96 * nilfs_palloc_desc_blkoff() returns block offset of the descriptor97 * block which contains a descriptor of the specified group.98 */99static unsigned long100nilfs_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 block109 * @inode: inode of metadata file using this allocator110 * @group: group number111 *112 * nilfs_palloc_bitmap_blkoff() returns block offset of the bitmap113 * block used to allocate/deallocate entries in the specified group.114 */115static unsigned long116nilfs_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 group126 * @desc: pointer to descriptor structure for the group127 * @lock: spin lock protecting @desc128 */129static unsigned long130nilfs_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 entries143 * @desc: pointer to descriptor structure for the group144 * @lock: spin lock protecting @desc145 * @n: delta to be added146 */147static u32148nilfs_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 block162 * @inode: inode of metadata file using this allocator163 * @nr: serial number of the entry (e.g. inode number)164 */165static unsigned long166nilfs_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 block178 * @inode: inode of metadata file179 * @bh: buffer head of the buffer to be initialized180 * @kaddr: kernel address mapped for the page including the buffer181 */182static void nilfs_palloc_desc_block_init(struct inode *inode,183 struct buffer_head *bh, void *kaddr)184{185 struct nilfs_palloc_group_desc *desc = kaddr + bh_offset(bh);186 unsigned long n = nilfs_palloc_groups_per_desc_block(inode);187 __le32 nfrees;188 189 nfrees = cpu_to_le32(nilfs_palloc_entries_per_group(inode));190 while (n-- > 0) {191 desc->pg_nfrees = nfrees;192 desc++;193 }194}195 196static int nilfs_palloc_get_block(struct inode *inode, unsigned long blkoff,197 int create,198 void (*init_block)(struct inode *,199 struct buffer_head *,200 void *),201 struct buffer_head **bhp,202 struct nilfs_bh_assoc *prev,203 spinlock_t *lock)204{205 int ret;206 207 spin_lock(lock);208 if (prev->bh && blkoff == prev->blkoff &&209 likely(buffer_uptodate(prev->bh))) {210 get_bh(prev->bh);211 *bhp = prev->bh;212 spin_unlock(lock);213 return 0;214 }215 spin_unlock(lock);216 217 ret = nilfs_mdt_get_block(inode, blkoff, create, init_block, bhp);218 if (!ret) {219 spin_lock(lock);220 /*221 * The following code must be safe for change of the222 * cache contents during the get block call.223 */224 brelse(prev->bh);225 get_bh(*bhp);226 prev->bh = *bhp;227 prev->blkoff = blkoff;228 spin_unlock(lock);229 }230 return ret;231}232 233/**234 * nilfs_palloc_delete_block - delete a block on the persistent allocator file235 * @inode: inode of metadata file using this allocator236 * @blkoff: block offset237 * @prev: nilfs_bh_assoc struct of the last used buffer238 * @lock: spin lock protecting @prev239 */240static int nilfs_palloc_delete_block(struct inode *inode, unsigned long blkoff,241 struct nilfs_bh_assoc *prev,242 spinlock_t *lock)243{244 spin_lock(lock);245 if (prev->bh && blkoff == prev->blkoff) {246 brelse(prev->bh);247 prev->bh = NULL;248 }249 spin_unlock(lock);250 return nilfs_mdt_delete_block(inode, blkoff);251}252 253/**254 * nilfs_palloc_get_desc_block - get buffer head of a group descriptor block255 * @inode: inode of metadata file using this allocator256 * @group: group number257 * @create: create flag258 * @bhp: pointer to store the resultant buffer head259 */260static int nilfs_palloc_get_desc_block(struct inode *inode,261 unsigned long group,262 int create, struct buffer_head **bhp)263{264 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;265 266 return nilfs_palloc_get_block(inode,267 nilfs_palloc_desc_blkoff(inode, group),268 create, nilfs_palloc_desc_block_init,269 bhp, &cache->prev_desc, &cache->lock);270}271 272/**273 * nilfs_palloc_get_bitmap_block - get buffer head of a bitmap block274 * @inode: inode of metadata file using this allocator275 * @group: group number276 * @create: create flag277 * @bhp: pointer to store the resultant buffer head278 */279static int nilfs_palloc_get_bitmap_block(struct inode *inode,280 unsigned long group,281 int create, struct buffer_head **bhp)282{283 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;284 285 return nilfs_palloc_get_block(inode,286 nilfs_palloc_bitmap_blkoff(inode, group),287 create, NULL, bhp,288 &cache->prev_bitmap, &cache->lock);289}290 291/**292 * nilfs_palloc_delete_bitmap_block - delete a bitmap block293 * @inode: inode of metadata file using this allocator294 * @group: group number295 */296static int nilfs_palloc_delete_bitmap_block(struct inode *inode,297 unsigned long group)298{299 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;300 301 return nilfs_palloc_delete_block(inode,302 nilfs_palloc_bitmap_blkoff(inode,303 group),304 &cache->prev_bitmap, &cache->lock);305}306 307/**308 * nilfs_palloc_get_entry_block - get buffer head of an entry block309 * @inode: inode of metadata file using this allocator310 * @nr: serial number of the entry (e.g. inode number)311 * @create: create flag312 * @bhp: pointer to store the resultant buffer head313 */314int nilfs_palloc_get_entry_block(struct inode *inode, __u64 nr,315 int create, struct buffer_head **bhp)316{317 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;318 319 return nilfs_palloc_get_block(inode,320 nilfs_palloc_entry_blkoff(inode, nr),321 create, NULL, bhp,322 &cache->prev_entry, &cache->lock);323}324 325/**326 * nilfs_palloc_delete_entry_block - delete an entry block327 * @inode: inode of metadata file using this allocator328 * @nr: serial number of the entry329 */330static int nilfs_palloc_delete_entry_block(struct inode *inode, __u64 nr)331{332 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;333 334 return nilfs_palloc_delete_block(inode,335 nilfs_palloc_entry_blkoff(inode, nr),336 &cache->prev_entry, &cache->lock);337}338 339/**340 * nilfs_palloc_block_get_group_desc - get kernel address of a group descriptor341 * @inode: inode of metadata file using this allocator342 * @group: group number343 * @bh: buffer head of the buffer storing the group descriptor block344 * @kaddr: kernel address mapped for the page including the buffer345 */346static struct nilfs_palloc_group_desc *347nilfs_palloc_block_get_group_desc(const struct inode *inode,348 unsigned long group,349 const struct buffer_head *bh, void *kaddr)350{351 return (struct nilfs_palloc_group_desc *)(kaddr + bh_offset(bh)) +352 group % nilfs_palloc_groups_per_desc_block(inode);353}354 355/**356 * nilfs_palloc_block_get_entry - get kernel address of an entry357 * @inode: inode of metadata file using this allocator358 * @nr: serial number of the entry (e.g. inode number)359 * @bh: buffer head of the buffer storing the entry block360 * @kaddr: kernel address mapped for the page including the buffer361 */362void *nilfs_palloc_block_get_entry(const struct inode *inode, __u64 nr,363 const struct buffer_head *bh, void *kaddr)364{365 unsigned long entry_offset, group_offset;366 367 nilfs_palloc_group(inode, nr, &group_offset);368 entry_offset = group_offset % NILFS_MDT(inode)->mi_entries_per_block;369 370 return kaddr + bh_offset(bh) +371 entry_offset * NILFS_MDT(inode)->mi_entry_size;372}373 374/**375 * nilfs_palloc_find_available_slot - find available slot in a group376 * @bitmap: bitmap of the group377 * @target: offset number of an entry in the group (start point)378 * @bsize: size in bits379 * @lock: spin lock protecting @bitmap380 * @wrap: whether to wrap around381 */382static int nilfs_palloc_find_available_slot(unsigned char *bitmap,383 unsigned long target,384 unsigned int bsize,385 spinlock_t *lock, bool wrap)386{387 int pos, end = bsize;388 389 if (likely(target < bsize)) {390 pos = target;391 do {392 pos = nilfs_find_next_zero_bit(bitmap, end, pos);393 if (pos >= end)394 break;395 if (!nilfs_set_bit_atomic(lock, pos, bitmap))396 return pos;397 } while (++pos < end);398 399 end = target;400 }401 if (!wrap)402 return -ENOSPC;403 404 /* wrap around */405 for (pos = 0; pos < end; pos++) {406 pos = nilfs_find_next_zero_bit(bitmap, end, pos);407 if (pos >= end)408 break;409 if (!nilfs_set_bit_atomic(lock, pos, bitmap))410 return pos;411 }412 413 return -ENOSPC;414}415 416/**417 * nilfs_palloc_rest_groups_in_desc_block - get the remaining number of groups418 * in a group descriptor block419 * @inode: inode of metadata file using this allocator420 * @curr: current group number421 * @max: maximum number of groups422 */423static unsigned long424nilfs_palloc_rest_groups_in_desc_block(const struct inode *inode,425 unsigned long curr, unsigned long max)426{427 return min_t(unsigned long,428 nilfs_palloc_groups_per_desc_block(inode) -429 curr % nilfs_palloc_groups_per_desc_block(inode),430 max - curr + 1);431}432 433/**434 * nilfs_palloc_count_desc_blocks - count descriptor blocks number435 * @inode: inode of metadata file using this allocator436 * @desc_blocks: descriptor blocks number [out]437 */438static int nilfs_palloc_count_desc_blocks(struct inode *inode,439 unsigned long *desc_blocks)440{441 __u64 blknum;442 int ret;443 444 ret = nilfs_bmap_last_key(NILFS_I(inode)->i_bmap, &blknum);445 if (likely(!ret))446 *desc_blocks = DIV_ROUND_UP(447 (unsigned long)blknum,448 NILFS_MDT(inode)->mi_blocks_per_desc_block);449 return ret;450}451 452/**453 * nilfs_palloc_mdt_file_can_grow - check potential opportunity for454 * MDT file growing455 * @inode: inode of metadata file using this allocator456 * @desc_blocks: known current descriptor blocks count457 */458static inline bool nilfs_palloc_mdt_file_can_grow(struct inode *inode,459 unsigned long desc_blocks)460{461 return (nilfs_palloc_groups_per_desc_block(inode) * desc_blocks) <462 nilfs_palloc_groups_count(inode);463}464 465/**466 * nilfs_palloc_count_max_entries - count max number of entries that can be467 * described by descriptor blocks count468 * @inode: inode of metadata file using this allocator469 * @nused: current number of used entries470 * @nmaxp: max number of entries [out]471 */472int nilfs_palloc_count_max_entries(struct inode *inode, u64 nused, u64 *nmaxp)473{474 unsigned long desc_blocks = 0;475 u64 entries_per_desc_block, nmax;476 int err;477 478 err = nilfs_palloc_count_desc_blocks(inode, &desc_blocks);479 if (unlikely(err))480 return err;481 482 entries_per_desc_block = (u64)nilfs_palloc_entries_per_group(inode) *483 nilfs_palloc_groups_per_desc_block(inode);484 nmax = entries_per_desc_block * desc_blocks;485 486 if (nused == nmax &&487 nilfs_palloc_mdt_file_can_grow(inode, desc_blocks))488 nmax += entries_per_desc_block;489 490 if (nused > nmax)491 return -ERANGE;492 493 *nmaxp = nmax;494 return 0;495}496 497/**498 * nilfs_palloc_prepare_alloc_entry - prepare to allocate a persistent object499 * @inode: inode of metadata file using this allocator500 * @req: nilfs_palloc_req structure exchanged for the allocation501 * @wrap: whether to wrap around502 */503int nilfs_palloc_prepare_alloc_entry(struct inode *inode,504 struct nilfs_palloc_req *req, bool wrap)505{506 struct buffer_head *desc_bh, *bitmap_bh;507 struct nilfs_palloc_group_desc *desc;508 unsigned char *bitmap;509 void *desc_kaddr, *bitmap_kaddr;510 unsigned long group, maxgroup, ngroups;511 unsigned long group_offset, maxgroup_offset;512 unsigned long n, entries_per_group;513 unsigned long i, j;514 spinlock_t *lock;515 int pos, ret;516 517 ngroups = nilfs_palloc_groups_count(inode);518 maxgroup = ngroups - 1;519 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);520 entries_per_group = nilfs_palloc_entries_per_group(inode);521 522 for (i = 0; i < ngroups; i += n) {523 if (group >= ngroups && wrap) {524 /* wrap around */525 group = 0;526 maxgroup = nilfs_palloc_group(inode, req->pr_entry_nr,527 &maxgroup_offset) - 1;528 }529 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);530 if (ret < 0)531 return ret;532 desc_kaddr = kmap_local_page(desc_bh->b_page);533 desc = nilfs_palloc_block_get_group_desc(534 inode, group, desc_bh, desc_kaddr);535 n = nilfs_palloc_rest_groups_in_desc_block(inode, group,536 maxgroup);537 for (j = 0; j < n; j++, desc++, group++, group_offset = 0) {538 lock = nilfs_mdt_bgl_lock(inode, group);539 if (nilfs_palloc_group_desc_nfrees(desc, lock) == 0)540 continue;541 542 kunmap_local(desc_kaddr);543 ret = nilfs_palloc_get_bitmap_block(inode, group, 1,544 &bitmap_bh);545 if (unlikely(ret < 0)) {546 brelse(desc_bh);547 return ret;548 }549 550 desc_kaddr = kmap_local_page(desc_bh->b_page);551 desc = nilfs_palloc_block_get_group_desc(552 inode, group, desc_bh, desc_kaddr);553 554 bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);555 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);556 pos = nilfs_palloc_find_available_slot(557 bitmap, group_offset, entries_per_group, lock,558 wrap);559 /*560 * Since the search for a free slot in the second and561 * subsequent bitmap blocks always starts from the562 * beginning, the wrap flag only has an effect on the563 * first search.564 */565 kunmap_local(bitmap_kaddr);566 if (pos >= 0)567 goto found;568 569 brelse(bitmap_bh);570 }571 572 kunmap_local(desc_kaddr);573 brelse(desc_bh);574 }575 576 /* no entries left */577 return -ENOSPC;578 579found:580 /* found a free entry */581 nilfs_palloc_group_desc_add_entries(desc, lock, -1);582 req->pr_entry_nr = entries_per_group * group + pos;583 kunmap_local(desc_kaddr);584 585 req->pr_desc_bh = desc_bh;586 req->pr_bitmap_bh = bitmap_bh;587 return 0;588}589 590/**591 * nilfs_palloc_commit_alloc_entry - finish allocation of a persistent object592 * @inode: inode of metadata file using this allocator593 * @req: nilfs_palloc_req structure exchanged for the allocation594 */595void nilfs_palloc_commit_alloc_entry(struct inode *inode,596 struct nilfs_palloc_req *req)597{598 mark_buffer_dirty(req->pr_bitmap_bh);599 mark_buffer_dirty(req->pr_desc_bh);600 nilfs_mdt_mark_dirty(inode);601 602 brelse(req->pr_bitmap_bh);603 brelse(req->pr_desc_bh);604}605 606/**607 * nilfs_palloc_commit_free_entry - finish deallocating a persistent object608 * @inode: inode of metadata file using this allocator609 * @req: nilfs_palloc_req structure exchanged for the removal610 */611void nilfs_palloc_commit_free_entry(struct inode *inode,612 struct nilfs_palloc_req *req)613{614 struct nilfs_palloc_group_desc *desc;615 unsigned long group, group_offset;616 unsigned char *bitmap;617 void *desc_kaddr, *bitmap_kaddr;618 spinlock_t *lock;619 620 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);621 desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);622 desc = nilfs_palloc_block_get_group_desc(inode, group,623 req->pr_desc_bh, desc_kaddr);624 bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);625 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);626 lock = nilfs_mdt_bgl_lock(inode, group);627 628 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))629 nilfs_warn(inode->i_sb,630 "%s (ino=%lu): entry number %llu already freed",631 __func__, inode->i_ino,632 (unsigned long long)req->pr_entry_nr);633 else634 nilfs_palloc_group_desc_add_entries(desc, lock, 1);635 636 kunmap_local(bitmap_kaddr);637 kunmap_local(desc_kaddr);638 639 mark_buffer_dirty(req->pr_desc_bh);640 mark_buffer_dirty(req->pr_bitmap_bh);641 nilfs_mdt_mark_dirty(inode);642 643 brelse(req->pr_bitmap_bh);644 brelse(req->pr_desc_bh);645}646 647/**648 * nilfs_palloc_abort_alloc_entry - cancel allocation of a persistent object649 * @inode: inode of metadata file using this allocator650 * @req: nilfs_palloc_req structure exchanged for the allocation651 */652void nilfs_palloc_abort_alloc_entry(struct inode *inode,653 struct nilfs_palloc_req *req)654{655 struct nilfs_palloc_group_desc *desc;656 void *desc_kaddr, *bitmap_kaddr;657 unsigned char *bitmap;658 unsigned long group, group_offset;659 spinlock_t *lock;660 661 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);662 desc_kaddr = kmap_local_page(req->pr_desc_bh->b_page);663 desc = nilfs_palloc_block_get_group_desc(inode, group,664 req->pr_desc_bh, desc_kaddr);665 bitmap_kaddr = kmap_local_page(req->pr_bitmap_bh->b_page);666 bitmap = bitmap_kaddr + bh_offset(req->pr_bitmap_bh);667 lock = nilfs_mdt_bgl_lock(inode, group);668 669 if (!nilfs_clear_bit_atomic(lock, group_offset, bitmap))670 nilfs_warn(inode->i_sb,671 "%s (ino=%lu): entry number %llu already freed",672 __func__, inode->i_ino,673 (unsigned long long)req->pr_entry_nr);674 else675 nilfs_palloc_group_desc_add_entries(desc, lock, 1);676 677 kunmap_local(bitmap_kaddr);678 kunmap_local(desc_kaddr);679 680 brelse(req->pr_bitmap_bh);681 brelse(req->pr_desc_bh);682 683 req->pr_entry_nr = 0;684 req->pr_bitmap_bh = NULL;685 req->pr_desc_bh = NULL;686}687 688/**689 * nilfs_palloc_prepare_free_entry - prepare to deallocate a persistent object690 * @inode: inode of metadata file using this allocator691 * @req: nilfs_palloc_req structure exchanged for the removal692 */693int nilfs_palloc_prepare_free_entry(struct inode *inode,694 struct nilfs_palloc_req *req)695{696 struct buffer_head *desc_bh, *bitmap_bh;697 unsigned long group, group_offset;698 int ret;699 700 group = nilfs_palloc_group(inode, req->pr_entry_nr, &group_offset);701 ret = nilfs_palloc_get_desc_block(inode, group, 1, &desc_bh);702 if (ret < 0)703 return ret;704 ret = nilfs_palloc_get_bitmap_block(inode, group, 1, &bitmap_bh);705 if (ret < 0) {706 brelse(desc_bh);707 return ret;708 }709 710 req->pr_desc_bh = desc_bh;711 req->pr_bitmap_bh = bitmap_bh;712 return 0;713}714 715/**716 * nilfs_palloc_abort_free_entry - cancel deallocating a persistent object717 * @inode: inode of metadata file using this allocator718 * @req: nilfs_palloc_req structure exchanged for the removal719 */720void nilfs_palloc_abort_free_entry(struct inode *inode,721 struct nilfs_palloc_req *req)722{723 brelse(req->pr_bitmap_bh);724 brelse(req->pr_desc_bh);725 726 req->pr_entry_nr = 0;727 req->pr_bitmap_bh = NULL;728 req->pr_desc_bh = NULL;729}730 731/**732 * nilfs_palloc_freev - deallocate a set of persistent objects733 * @inode: inode of metadata file using this allocator734 * @entry_nrs: array of entry numbers to be deallocated735 * @nitems: number of entries stored in @entry_nrs736 */737int nilfs_palloc_freev(struct inode *inode, __u64 *entry_nrs, size_t nitems)738{739 struct buffer_head *desc_bh, *bitmap_bh;740 struct nilfs_palloc_group_desc *desc;741 unsigned char *bitmap;742 void *desc_kaddr, *bitmap_kaddr;743 unsigned long group, group_offset;744 __u64 group_min_nr, last_nrs[8];745 const unsigned long epg = nilfs_palloc_entries_per_group(inode);746 const unsigned int epb = NILFS_MDT(inode)->mi_entries_per_block;747 unsigned int entry_start, end, pos;748 spinlock_t *lock;749 int i, j, k, ret;750 u32 nfree;751 752 for (i = 0; i < nitems; i = j) {753 int change_group = false;754 int nempties = 0, n = 0;755 756 group = nilfs_palloc_group(inode, entry_nrs[i], &group_offset);757 ret = nilfs_palloc_get_desc_block(inode, group, 0, &desc_bh);758 if (ret < 0)759 return ret;760 ret = nilfs_palloc_get_bitmap_block(inode, group, 0,761 &bitmap_bh);762 if (ret < 0) {763 brelse(desc_bh);764 return ret;765 }766 767 /* Get the first entry number of the group */768 group_min_nr = (__u64)group * epg;769 770 bitmap_kaddr = kmap_local_page(bitmap_bh->b_page);771 bitmap = bitmap_kaddr + bh_offset(bitmap_bh);772 lock = nilfs_mdt_bgl_lock(inode, group);773 774 j = i;775 entry_start = rounddown(group_offset, epb);776 do {777 if (!nilfs_clear_bit_atomic(lock, group_offset,778 bitmap)) {779 nilfs_warn(inode->i_sb,780 "%s (ino=%lu): entry number %llu already freed",781 __func__, inode->i_ino,782 (unsigned long long)entry_nrs[j]);783 } else {784 n++;785 }786 787 j++;788 if (j >= nitems || entry_nrs[j] < group_min_nr ||789 entry_nrs[j] >= group_min_nr + epg) {790 change_group = true;791 } else {792 group_offset = entry_nrs[j] - group_min_nr;793 if (group_offset >= entry_start &&794 group_offset < entry_start + epb) {795 /* This entry is in the same block */796 continue;797 }798 }799 800 /* Test if the entry block is empty or not */801 end = entry_start + epb;802 pos = nilfs_find_next_bit(bitmap, end, entry_start);803 if (pos >= end) {804 last_nrs[nempties++] = entry_nrs[j - 1];805 if (nempties >= ARRAY_SIZE(last_nrs))806 break;807 }808 809 if (change_group)810 break;811 812 /* Go on to the next entry block */813 entry_start = rounddown(group_offset, epb);814 } while (true);815 816 kunmap_local(bitmap_kaddr);817 mark_buffer_dirty(bitmap_bh);818 brelse(bitmap_bh);819 820 for (k = 0; k < nempties; k++) {821 ret = nilfs_palloc_delete_entry_block(inode,822 last_nrs[k]);823 if (ret && ret != -ENOENT)824 nilfs_warn(inode->i_sb,825 "error %d deleting block that object (entry=%llu, ino=%lu) belongs to",826 ret, (unsigned long long)last_nrs[k],827 inode->i_ino);828 }829 830 desc_kaddr = kmap_local_page(desc_bh->b_page);831 desc = nilfs_palloc_block_get_group_desc(832 inode, group, desc_bh, desc_kaddr);833 nfree = nilfs_palloc_group_desc_add_entries(desc, lock, n);834 kunmap_local(desc_kaddr);835 mark_buffer_dirty(desc_bh);836 nilfs_mdt_mark_dirty(inode);837 brelse(desc_bh);838 839 if (nfree == nilfs_palloc_entries_per_group(inode)) {840 ret = nilfs_palloc_delete_bitmap_block(inode, group);841 if (ret && ret != -ENOENT)842 nilfs_warn(inode->i_sb,843 "error %d deleting bitmap block of group=%lu, ino=%lu",844 ret, group, inode->i_ino);845 }846 }847 return 0;848}849 850void nilfs_palloc_setup_cache(struct inode *inode,851 struct nilfs_palloc_cache *cache)852{853 NILFS_MDT(inode)->mi_palloc_cache = cache;854 spin_lock_init(&cache->lock);855}856 857void nilfs_palloc_clear_cache(struct inode *inode)858{859 struct nilfs_palloc_cache *cache = NILFS_MDT(inode)->mi_palloc_cache;860 861 spin_lock(&cache->lock);862 brelse(cache->prev_desc.bh);863 brelse(cache->prev_bitmap.bh);864 brelse(cache->prev_entry.bh);865 cache->prev_desc.bh = NULL;866 cache->prev_bitmap.bh = NULL;867 cache->prev_entry.bh = NULL;868 spin_unlock(&cache->lock);869}870 871void nilfs_palloc_destroy_cache(struct inode *inode)872{873 nilfs_palloc_clear_cache(inode);874 NILFS_MDT(inode)->mi_palloc_cache = NULL;875}876