cregit-Linux how code gets into the kernel

Release 4.11 fs/jfs/jfs_dtree.h

Directory: fs/jfs
/*
 *   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 */

Overall Contributors

PersonTokensPropCommitsCommitProp
Dave Kleikamp60799.02%675.00%
Al Viro40.65%112.50%
Shaun Zinck20.33%112.50%
Total613100.00%8100.00%
Directory: fs/jfs
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