original development tree for Linux kernel GTP module; now long in mainline.
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/*
* bmap.h - NILFS block mapping.
*
* Copyright (C) 2006-2008 Nippon Telegraph and Telephone Corporation.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; if not, write to the Free Software
* Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
*
* Written by Koji Sato <koji@osrg.net>.
*/
#ifndef _NILFS_BMAP_H
#define _NILFS_BMAP_H
#include <linux/types.h>
#include <linux/fs.h>
#include <linux/buffer_head.h>
#include <linux/nilfs2_fs.h>
#include "alloc.h"
#include "dat.h"
#define NILFS_BMAP_INVALID_PTR 0
#define nilfs_bmap_keydiff_abs(diff) ((diff) < 0 ? -(diff) : (diff))
struct nilfs_bmap;
/**
* union nilfs_bmap_ptr_req - request for bmap ptr
* @bpr_ptr: bmap pointer
* @bpr_req: request for persistent allocator
*/
union nilfs_bmap_ptr_req {
__u64 bpr_ptr;
struct nilfs_palloc_req bpr_req;
};
/**
* struct nilfs_bmap_stats - bmap statistics
* @bs_nblocks: number of blocks created or deleted
*/
struct nilfs_bmap_stats {
unsigned int bs_nblocks;
};
/**
* struct nilfs_bmap_operations - bmap operation table
*/
struct nilfs_bmap_operations {
int (*bop_lookup)(const struct nilfs_bmap *, __u64, int, __u64 *);
int (*bop_lookup_contig)(const struct nilfs_bmap *, __u64, __u64 *,
unsigned);
int (*bop_insert)(struct nilfs_bmap *, __u64, __u64);
int (*bop_delete)(struct nilfs_bmap *, __u64);
void (*bop_clear)(struct nilfs_bmap *);
int (*bop_propagate)(struct nilfs_bmap *, struct buffer_head *);
void (*bop_lookup_dirty_buffers)(struct nilfs_bmap *,
struct list_head *);
int (*bop_assign)(struct nilfs_bmap *,
struct buffer_head **,
sector_t,
union nilfs_binfo *);
int (*bop_mark)(struct nilfs_bmap *, __u64, int);
/* The following functions are internal use only. */
int (*bop_last_key)(const struct nilfs_bmap *, __u64 *);
int (*bop_check_insert)(const struct nilfs_bmap *, __u64);
int (*bop_check_delete)(struct nilfs_bmap *, __u64);
int (*bop_gather_data)(struct nilfs_bmap *, __u64 *, __u64 *, int);
};
#define NILFS_BMAP_SIZE (NILFS_INODE_BMAP_SIZE * sizeof(__le64))
#define NILFS_BMAP_KEY_BIT (sizeof(unsigned long) * 8 /* CHAR_BIT */)
#define NILFS_BMAP_NEW_PTR_INIT \
(1UL << (sizeof(unsigned long) * 8 /* CHAR_BIT */ - 1))
static inline int nilfs_bmap_is_new_ptr(unsigned long ptr)
{
return !!(ptr & NILFS_BMAP_NEW_PTR_INIT);
}
/**
* struct nilfs_bmap - bmap structure
* @b_u: raw data
* @b_sem: semaphore
* @b_inode: owner of bmap
* @b_ops: bmap operation table
* @b_last_allocated_key: last allocated key for data block
* @b_last_allocated_ptr: last allocated ptr for data block
* @b_ptr_type: pointer type
* @b_state: state
* @b_nchildren_per_block: maximum number of child nodes for non-root nodes
*/
struct nilfs_bmap {
union {
__u8 u_flags;
__le64 u_data[NILFS_BMAP_SIZE / sizeof(__le64)];
} b_u;
struct rw_semaphore b_sem;
struct inode *b_inode;
const struct nilfs_bmap_operations *b_ops;
__u64 b_last_allocated_key;
__u64 b_last_allocated_ptr;
int b_ptr_type;
int b_state;
__u16 b_nchildren_per_block;
};
/* pointer type */
#define NILFS_BMAP_PTR_P 0 /* physical block number (i.e. LBN) */
#define NILFS_BMAP_PTR_VS 1 /* virtual block number (single
version) */
#define NILFS_BMAP_PTR_VM 2 /* virtual block number (has multiple
versions) */
#define NILFS_BMAP_PTR_U (-1) /* never perform pointer operations */
#define NILFS_BMAP_USE_VBN(bmap) ((bmap)->b_ptr_type > 0)
/* state */
#define NILFS_BMAP_DIRTY 0x00000001
/**
* struct nilfs_bmap_store - shadow copy of bmap state
* @data: cached raw block mapping of on-disk inode
* @last_allocated_key: cached value of last allocated key for data block
* @last_allocated_ptr: cached value of last allocated ptr for data block
* @state: cached value of state field of bmap structure
*/
struct nilfs_bmap_store {
__le64 data[NILFS_BMAP_SIZE / sizeof(__le64)];
__u64 last_allocated_key;
__u64 last_allocated_ptr;
int state;
};
int nilfs_bmap_test_and_clear_dirty(struct nilfs_bmap *);
int nilfs_bmap_read(struct nilfs_bmap *, struct nilfs_inode *);
void nilfs_bmap_write(struct nilfs_bmap *, struct nilfs_inode *);
int nilfs_bmap_lookup_contig(struct nilfs_bmap *, __u64, __u64 *, unsigned);
int nilfs_bmap_insert(struct nilfs_bmap *, unsigned long, unsigned long);
int nilfs_bmap_delete(struct nilfs_bmap *, unsigned long);
int nilfs_bmap_last_key(struct nilfs_bmap *, unsigned long *);
int nilfs_bmap_truncate(struct nilfs_bmap *, unsigned long);
void nilfs_bmap_clear(struct nilfs_bmap *);
int nilfs_bmap_propagate(struct nilfs_bmap *, struct buffer_head *);
void nilfs_bmap_lookup_dirty_buffers(struct nilfs_bmap *, struct list_head *);
int nilfs_bmap_assign(struct nilfs_bmap *, struct buffer_head **,
unsigned long, union nilfs_binfo *);
int nilfs_bmap_lookup_at_level(struct nilfs_bmap *, __u64, int, __u64 *);
int nilfs_bmap_mark(struct nilfs_bmap *, __u64, int);
void nilfs_bmap_init_gc(struct nilfs_bmap *);
void nilfs_bmap_save(const struct nilfs_bmap *, struct nilfs_bmap_store *);
void nilfs_bmap_restore(struct nilfs_bmap *, const struct nilfs_bmap_store *);
static inline int nilfs_bmap_lookup(struct nilfs_bmap *bmap, __u64 key,
__u64 *ptr)
{
return nilfs_bmap_lookup_at_level(bmap, key, 1, ptr);
}
/*
* Internal use only
*/
struct inode *nilfs_bmap_get_dat(const struct nilfs_bmap *);
static inline int nilfs_bmap_prepare_alloc_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
if (dat)
return nilfs_dat_prepare_alloc(dat, &req->bpr_req);
/* ignore target ptr */
req->bpr_ptr = bmap->b_last_allocated_ptr++;
return 0;
}
static inline void nilfs_bmap_commit_alloc_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
if (dat)
nilfs_dat_commit_alloc(dat, &req->bpr_req);
}
static inline void nilfs_bmap_abort_alloc_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
if (dat)
nilfs_dat_abort_alloc(dat, &req->bpr_req);
else
bmap->b_last_allocated_ptr--;
}
static inline int nilfs_bmap_prepare_end_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
return dat ? nilfs_dat_prepare_end(dat, &req->bpr_req) : 0;
}
static inline void nilfs_bmap_commit_end_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
if (dat)
nilfs_dat_commit_end(dat, &req->bpr_req,
bmap->b_ptr_type == NILFS_BMAP_PTR_VS);
}
static inline void nilfs_bmap_abort_end_ptr(struct nilfs_bmap *bmap,
union nilfs_bmap_ptr_req *req,
struct inode *dat)
{
if (dat)
nilfs_dat_abort_end(dat, &req->bpr_req);
}
static inline void nilfs_bmap_set_target_v(struct nilfs_bmap *bmap, __u64 key,
__u64 ptr)
{
bmap->b_last_allocated_key = key;
bmap->b_last_allocated_ptr = ptr;
}
__u64 nilfs_bmap_data_get_key(const struct nilfs_bmap *,
const struct buffer_head *);
__u64 nilfs_bmap_find_target_seq(const struct nilfs_bmap *, __u64);
__u64 nilfs_bmap_find_target_in_group(const struct nilfs_bmap *);
/* Assume that bmap semaphore is locked. */
static inline int nilfs_bmap_dirty(const struct nilfs_bmap *bmap)
{
return !!(bmap->b_state & NILFS_BMAP_DIRTY);
}
/* Assume that bmap semaphore is locked. */
static inline void nilfs_bmap_set_dirty(struct nilfs_bmap *bmap)
{
bmap->b_state |= NILFS_BMAP_DIRTY;
}
/* Assume that bmap semaphore is locked. */
static inline void nilfs_bmap_clear_dirty(struct nilfs_bmap *bmap)
{
bmap->b_state &= ~NILFS_BMAP_DIRTY;
}
#define NILFS_BMAP_LARGE 0x1
#define NILFS_BMAP_SMALL_LOW NILFS_DIRECT_KEY_MIN
#define NILFS_BMAP_SMALL_HIGH NILFS_DIRECT_KEY_MAX
#define NILFS_BMAP_LARGE_LOW NILFS_BTREE_ROOT_NCHILDREN_MAX
#define NILFS_BMAP_LARGE_HIGH NILFS_BTREE_KEY_MAX
#endif /* _NILFS_BMAP_H */