forked from Minki/linux
db55d92252
The implementation of persistent object allocator (alloc.c) is poorly documented. This adds kernel doc style comments on that functions. Signed-off-by: Ryusuke Konishi <konishi.ryusuke@lab.ntt.co.jp>
101 lines
3.5 KiB
C
101 lines
3.5 KiB
C
/*
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* alloc.h - persistent object (dat entry/disk inode) allocator/deallocator
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*
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* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
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*
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* This program is free software; you can redistribute it and/or modify
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* it under the terms of the GNU General Public License as published by
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* the Free Software Foundation; either version 2 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU General Public License for more details.
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*
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* You should have received a copy of the GNU General Public License
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* along with this program; if not, write to the Free Software
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* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
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*
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* Original code was written by Koji Sato <koji@osrg.net>.
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* Two allocators were unified by Ryusuke Konishi <ryusuke@osrg.net>,
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* Amagai Yoshiji <amagai@osrg.net>.
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*/
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#ifndef _NILFS_ALLOC_H
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#define _NILFS_ALLOC_H
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#include <linux/types.h>
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#include <linux/buffer_head.h>
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#include <linux/fs.h>
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/**
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* nilfs_palloc_entries_per_group - get the number of entries per group
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* @inode: inode of metadata file using this allocator
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*
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* The number of entries per group is defined by the number of bits
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* that a bitmap block can maintain.
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*/
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static inline unsigned long
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nilfs_palloc_entries_per_group(const struct inode *inode)
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{
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return 1UL << (inode->i_blkbits + 3 /* log2(8 = CHAR_BITS) */);
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}
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int nilfs_palloc_init_blockgroup(struct inode *, unsigned);
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int nilfs_palloc_get_entry_block(struct inode *, __u64, int,
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struct buffer_head **);
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void *nilfs_palloc_block_get_entry(const struct inode *, __u64,
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const struct buffer_head *, void *);
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/**
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* nilfs_palloc_req - persistent allocator request and reply
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* @pr_entry_nr: entry number (vblocknr or inode number)
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* @pr_desc_bh: buffer head of the buffer containing block group descriptors
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* @pr_bitmap_bh: buffer head of the buffer containing a block group bitmap
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* @pr_entry_bh: buffer head of the buffer containing translation entries
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*/
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struct nilfs_palloc_req {
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__u64 pr_entry_nr;
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struct buffer_head *pr_desc_bh;
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struct buffer_head *pr_bitmap_bh;
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struct buffer_head *pr_entry_bh;
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};
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int nilfs_palloc_prepare_alloc_entry(struct inode *,
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struct nilfs_palloc_req *);
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void nilfs_palloc_commit_alloc_entry(struct inode *,
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struct nilfs_palloc_req *);
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void nilfs_palloc_abort_alloc_entry(struct inode *, struct nilfs_palloc_req *);
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void nilfs_palloc_commit_free_entry(struct inode *, struct nilfs_palloc_req *);
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int nilfs_palloc_prepare_free_entry(struct inode *, struct nilfs_palloc_req *);
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void nilfs_palloc_abort_free_entry(struct inode *, struct nilfs_palloc_req *);
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int nilfs_palloc_freev(struct inode *, __u64 *, size_t);
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#define nilfs_set_bit_atomic ext2_set_bit_atomic
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#define nilfs_clear_bit_atomic ext2_clear_bit_atomic
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#define nilfs_find_next_zero_bit ext2_find_next_zero_bit
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/*
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* persistent object allocator cache
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*/
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struct nilfs_bh_assoc {
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unsigned long blkoff;
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struct buffer_head *bh;
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};
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struct nilfs_palloc_cache {
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spinlock_t lock;
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struct nilfs_bh_assoc prev_desc;
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struct nilfs_bh_assoc prev_bitmap;
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struct nilfs_bh_assoc prev_entry;
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};
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void nilfs_palloc_setup_cache(struct inode *inode,
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struct nilfs_palloc_cache *cache);
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void nilfs_palloc_clear_cache(struct inode *inode);
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void nilfs_palloc_destroy_cache(struct inode *inode);
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#endif /* _NILFS_ALLOC_H */
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