- 根目录:
- fs
- jfs
- jfs_dtree.h
/*
* Copyright (C) International Business Machines Corp., 2000-2002
*
* 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., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef _H_JFS_DTREE
#define _H_JFS_DTREE
/*
* jfs_dtree.h: directory B+-tree manager
*/
#include "jfs_btree.h"
typedef union {
struct {
tid_t tid;
struct inode *ip;
u32 ino;
} leaf;
pxd_t xd;
} ddata_t;
/*
* entry segment/slot
*
* an entry consists of type dependent head/only segment/slot and
* additional segments/slots linked vi next field;
* N.B. last/only segment of entry is terminated by next = -1;
*/
/*
* directory page slot
*/
struct dtslot {
s8 next; /* 1: */
s8 cnt; /* 1: */
__le16 name[15]; /* 30: */
}; /* (32) */
#define DATASLOTSIZE 16
#define L2DATASLOTSIZE 4
#define DTSLOTSIZE 32
#define L2DTSLOTSIZE 5
#define DTSLOTHDRSIZE 2
#define DTSLOTDATASIZE 30
#define DTSLOTDATALEN 15
/*
* internal node entry head/only segment
*/
struct idtentry {
pxd_t xd; /* 8: child extent descriptor */
s8 next; /* 1: */
u8 namlen; /* 1: */
__le16 name[11]; /* 22: 2-byte aligned */
}; /* (32) */
#define DTIHDRSIZE 10
#define DTIHDRDATALEN 11
/* compute number of slots for entry */
#define NDTINTERNAL(klen) (DIV_ROUND_UP((4 + (klen)), 15))
/*
* leaf node entry head/only segment
*
* For legacy filesystems, name contains 13 wchars -- no index field
*/
struct ldtentry {
__le32 inumber; /* 4: 4-byte aligned */
s8 next; /* 1: */
u8 namlen; /* 1: */
__le16 name[11]; /* 22: 2-byte aligned */
__le32 index; /* 4: index into dir_table */
}; /* (32) */
#define DTLHDRSIZE 6
#define DTLHDRDATALEN_LEGACY 13 /* Old (OS/2) format */
#define DTLHDRDATALEN 11
/*
* dir_table used for directory traversal during readdir
*/
/*
* Keep persistent index for directory entries
*/
#define DO_INDEX(INODE) (JFS_SBI((INODE)->i_sb)->mntflag & JFS_DIR_INDEX)
/*
* Maximum entry in inline directory table
*/
#define MAX_INLINE_DIRTABLE_ENTRY 13
struct dir_table_slot {
u8 rsrvd; /* 1: */
u8 flag; /* 1: 0 if free */
u8 slot; /* 1: slot within leaf page of entry */
u8 addr1; /* 1: upper 8 bits of leaf page address */
__le32 addr2; /* 4: lower 32 bits of leaf page address -OR-
index of next entry when this entry was deleted */
}; /* (8) */
/*
* flag values
*/
#define DIR_INDEX_VALID 1
#define DIR_INDEX_FREE 0
#define DTSaddress(dir_table_slot, address64)\
{\
(dir_table_slot)->addr1 = ((u64)address64) >> 32;\
(dir_table_slot)->addr2 = __cpu_to_le32((address64) & 0xffffffff);\
}
#define addressDTS(dts)\
( ((s64)((dts)->addr1)) << 32 | __le32_to_cpu((dts)->addr2) )
/* compute number of slots for entry */
#define NDTLEAF_LEGACY(klen) (DIV_ROUND_UP((2 + (klen)), 15))
#define NDTLEAF NDTINTERNAL
/*
* directory root page (in-line in on-disk inode):
*
* cf. dtpage_t below.
*/
typedef union {
struct {
struct dasd DASD; /* 16: DASD limit/usage info */
u8 flag; /* 1: */
u8 nextindex; /* 1: next free entry in stbl */
s8 freecnt; /* 1: free count */
s8 freelist; /* 1: freelist header */
__le32 idotdot; /* 4: parent inode number */
s8 stbl[8]; /* 8: sorted entry index table */
} header; /* (32) */
struct dtslot slot[9];
} dtroot_t;
#define PARENT(IP) \
(le32_to_cpu(JFS_IP(IP)->i_dtroot.header.idotdot))
#define DTROOTMAXSLOT 9
#define dtEmpty(IP) (JFS_IP(IP)->i_dtroot.header.nextindex == 0)
/*
* directory regular page:
*
* entry slot array of 32 byte slot
*
* sorted entry slot index table (stbl):
* contiguous slots at slot specified by stblindex,
* 1-byte per entry
* 512 byte block: 16 entry tbl (1 slot)
* 1024 byte block: 32 entry tbl (1 slot)
* 2048 byte block: 64 entry tbl (2 slot)
* 4096 byte block: 128 entry tbl (4 slot)
*
* data area:
* 512 byte block: 16 - 2 = 14 slot
* 1024 byte block: 32 - 2 = 30 slot
* 2048 byte block: 64 - 3 = 61 slot
* 4096 byte block: 128 - 5 = 123 slot
*
* N.B. index is 0-based; index fields refer to slot index
* except nextindex which refers to entry index in stbl;
* end of entry stot list or freelist is marked with -1.
*/
typedef union {
struct {
__le64 next; /* 8: next sibling */
__le64 prev; /* 8: previous sibling */
u8 flag; /* 1: */
u8 nextindex; /* 1: next entry index in stbl */
s8 freecnt; /* 1: */
s8 freelist; /* 1: slot index of head of freelist */
u8 maxslot; /* 1: number of slots in page slot[] */
u8 stblindex; /* 1: slot index of start of stbl */
u8 rsrvd[2]; /* 2: */
pxd_t self; /* 8: self pxd */
} header; /* (32) */
struct dtslot slot[128];
} dtpage_t;
#define DTPAGEMAXSLOT 128
#define DT8THPGNODEBYTES 512
#define DT8THPGNODETSLOTS 1
#define DT8THPGNODESLOTS 16
#define DTQTRPGNODEBYTES 1024
#define DTQTRPGNODETSLOTS 1
#define DTQTRPGNODESLOTS 32
#define DTHALFPGNODEBYTES 2048
#define DTHALFPGNODETSLOTS 2
#define DTHALFPGNODESLOTS 64
#define DTFULLPGNODEBYTES 4096
#define DTFULLPGNODETSLOTS 4
#define DTFULLPGNODESLOTS 128
#define DTENTRYSTART 1
/* get sorted entry table of the page */
#define DT_GETSTBL(p) ( ((p)->header.flag & BT_ROOT) ?\
((dtroot_t *)(p))->header.stbl : \
(s8 *)&(p)->slot[(p)->header.stblindex] )
/*
* Flags for dtSearch
*/
#define JFS_CREATE 1
#define JFS_LOOKUP 2
#define JFS_REMOVE 3
#define JFS_RENAME 4
/*
* Maximum file offset for directories.
*/
#define DIREND INT_MAX
/*
* external declarations
*/
extern void dtInitRoot(tid_t tid, struct inode *ip, u32 idotdot);
extern int dtSearch(struct inode *ip, struct component_name * key,
ino_t * data, struct btstack * btstack, int flag);
extern int dtInsert(tid_t tid, struct inode *ip, struct component_name * key,
ino_t * ino, struct btstack * btstack);
extern int dtDelete(tid_t tid, struct inode *ip, struct component_name * key,
ino_t * data, int flag);
extern int dtModify(tid_t tid, struct inode *ip, struct component_name * key,
ino_t * orig_ino, ino_t new_ino, int flag);
extern int jfs_readdir(struct file *file, struct dir_context *ctx);
#endif /* !_H_JFS_DTREE */