1 /* 2 * alloc.h - persistent object (dat entry/disk inode) allocator/deallocator 3 * 4 * Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License as published by 8 * the Free Software Foundation; either version 2 of the License, or 9 * (at your option) any later version. 10 * 11 * This program is distributed in the hope that it will be useful, 12 * but WITHOUT ANY WARRANTY; without even the implied warranty of 13 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 14 * GNU General Public License for more details. 15 * 16 * You should have received a copy of the GNU General Public License 17 * along with this program; if not, write to the Free Software 18 * Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA 19 * 20 * Original code was written by Koji Sato <koji@osrg.net>. 21 * Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>, 22 * Amagai Yoshiji <amagai@osrg.net>. 23 */ 24 25 #ifndef _NILFS_ALLOC_H 26 #define _NILFS_ALLOC_H 27 28 #include <linux/types.h> 29 #include <linux/buffer_head.h> 30 #include <linux/fs.h> 31 32 /** 33 * nilfs_palloc_entries_per_group - get the number of entries per group 34 * @inode: inode of metadata file using this allocator 35 * 36 * The number of entries per group is defined by the number of bits 37 * that a bitmap block can maintain. 38 */ 39 static inline unsigned long 40 nilfs_palloc_entries_per_group(const struct inode *inode) 41 { 42 return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */); 43 } 44 45 int nilfs_palloc_init_blockgroup(struct inode *, unsigned); 46 int nilfs_palloc_get_entry_block(struct inode *, __u64, int, 47 struct buffer_head **); 48 void *nilfs_palloc_block_get_entry(const struct inode *, __u64, 49 const struct buffer_head *, void *); 50 51 /** 52 * nilfs_palloc_req - persistent allocator request and reply 53 * @pr_entry_nr: entry number (vblocknr or inode number) 54 * @pr_desc_bh: buffer head of the buffer containing block group descriptors 55 * @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap 56 * @pr_entry_bh: buffer head of the buffer containing translation entries 57 */ 58 struct nilfs_palloc_req { 59 __u64 pr_entry_nr; 60 struct buffer_head *pr_desc_bh; 61 struct buffer_head *pr_bitmap_bh; 62 struct buffer_head *pr_entry_bh; 63 }; 64 65 int nilfs_palloc_prepare_alloc_entry(struct inode *, 66 struct nilfs_palloc_req *); 67 void nilfs_palloc_commit_alloc_entry(struct inode *, 68 struct nilfs_palloc_req *); 69 void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *); 70 void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *); 71 int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *); 72 void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *); 73 int nilfs_palloc_freev(struct inode *, __u64 *, size_t); 74 75 #define nilfs_set_bit_atomic ext2_set_bit_atomic 76 #define nilfs_clear_bit_atomic ext2_clear_bit_atomic 77 #define nilfs_find_next_zero_bit find_next_zero_bit_le 78 79 /** 80 * struct nilfs_bh_assoc - block offset and buffer head association 81 * @blkoff: block offset 82 * @bh: buffer head 83 */ 84 struct nilfs_bh_assoc { 85 unsigned long blkoff; 86 struct buffer_head *bh; 87 }; 88 89 /** 90 * struct nilfs_palloc_cache - persistent object allocator cache 91 * @lock: cache protecting lock 92 * @prev_desc: blockgroup descriptors cache 93 * @prev_bitmap: blockgroup bitmap cache 94 * @prev_entry: translation entries cache 95 */ 96 struct nilfs_palloc_cache { 97 spinlock_t lock; 98 struct nilfs_bh_assoc prev_desc; 99 struct nilfs_bh_assoc prev_bitmap; 100 struct nilfs_bh_assoc prev_entry; 101 }; 102 103 void nilfs_palloc_setup_cache(struct inode *inode, 104 struct nilfs_palloc_cache *cache); 105 void nilfs_palloc_clear_cache(struct inode *inode); 106 void nilfs_palloc_destroy_cache(struct inode *inode); 107 108 #endif /* _NILFS_ALLOC_H */ 109