cregit-Linux how code gets into the kernel

Release 4.10 fs/jfs/jfs_btree.h

Directory: fs/jfs
/*
 *   Copyright (C) International Business Machines Corp., 2000-2004
 *
 *   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_BTREE

#define _H_JFS_BTREE

/*
 *      jfs_btree.h: B+-tree
 *
 * JFS B+-tree (dtree and xtree) common definitions
 */

/*
 *      basic btree page - btpage
 *
struct btpage {
        s64 next;               right sibling bn
        s64 prev;               left sibling bn

        u8 flag;
        u8 rsrvd[7];            type specific
        s64 self;               self address

        u8 entry[4064];
};                                              */

/* btpaget_t flag */

#define BT_TYPE		0x07	
/* B+-tree index */

#define	BT_ROOT		0x01	
/* root page */

#define	BT_LEAF		0x02	
/* leaf page */

#define	BT_INTERNAL	0x04	
/* internal page */

#define	BT_RIGHTMOST	0x10	
/* rightmost page */

#define	BT_LEFTMOST	0x20	
/* leftmost page */

#define	BT_SWAPPED	0x80	
/* used by fsck for endian swapping */

/* btorder (in inode) */

#define	BT_RANDOM		0x0000

#define	BT_SEQUENTIAL		0x0001

#define	BT_LOOKUP		0x0010

#define	BT_INSERT		0x0020

#define	BT_DELETE		0x0040

/*
 *      btree page buffer cache access
 */

#define BT_IS_ROOT(MP) (((MP)->xflag & COMMIT_PAGE) == 0)

/* get page from buffer page */

#define BT_PAGE(IP, MP, TYPE, ROOT)\
	(BT_IS_ROOT(MP) ? (TYPE *)&JFS_IP(IP)->ROOT : (TYPE *)(MP)->data)

/* get the page buffer and the page for specified block address */

#define BT_GETPAGE(IP, BN, MP, TYPE, SIZE, P, RC, ROOT)\
{\
        if ((BN) == 0)\
        {\
                MP = (struct metapage *)&JFS_IP(IP)->bxflag;\
                P = (TYPE *)&JFS_IP(IP)->ROOT;\
                RC = 0;\
        }\
        else\
        {\
                MP = read_metapage((IP), BN, SIZE, 1);\
                if (MP) {\
                        RC = 0;\
                        P = (MP)->data;\
                } else {\
                        P = NULL;\
                        jfs_err("bread failed!");\
                        RC = -EIO;\
                }\
        }\
}


#define BT_MARK_DIRTY(MP, IP)\
{\
        if (BT_IS_ROOT(MP))\
                mark_inode_dirty(IP);\
        else\
                mark_metapage_dirty(MP);\
}

/* put the page buffer */

#define BT_PUTPAGE(MP)\
{\
        if (! BT_IS_ROOT(MP)) \
                release_metapage(MP); \
}


/*
 *      btree traversal stack
 *
 * record the path traversed during the search;
 * top frame record the leaf page/entry selected.
 */

struct btframe {	/* stack frame */
	
s64 bn;			/* 8: */
	
s16 index;		/* 2: */
	
s16 lastindex;		/* 2: unused */
	
struct metapage *mp;	/* 4/8: */
};				/* (16/24) */


struct btstack {
	
struct btframe *top;
	
int nsplit;
	
struct btframe stack[MAXTREEHEIGHT];
};


#define BT_CLR(btstack)\
	(btstack)->top = (btstack)->stack


#define BT_STACK_FULL(btstack)\
	( (btstack)->top == &((btstack)->stack[MAXTREEHEIGHT-1]))


#define BT_PUSH(BTSTACK, BN, INDEX)\
{\
        assert(!BT_STACK_FULL(BTSTACK));\
        (BTSTACK)->top->bn = BN;\
        (BTSTACK)->top->index = INDEX;\
        ++(BTSTACK)->top;\
}


#define BT_POP(btstack)\
	( (btstack)->top == (btstack)->stack ? NULL : --(btstack)->top )


#define BT_STACK(btstack)\
	( (btstack)->top == (btstack)->stack ? NULL : (btstack)->top )


static inline void BT_STACK_DUMP(struct btstack *btstack) { int i; printk("btstack dump:\n"); for (i = 0; i < MAXTREEHEIGHT; i++) printk(KERN_ERR "bn = %Lx, index = %d\n", (long long)btstack->stack[i].bn, btstack->stack[i].index); }

Contributors

PersonTokensPropCommitsCommitProp
dave kleikampdave kleikamp5793.44%150.00%
andrew mortonandrew morton46.56%150.00%
Total61100.00%2100.00%

/* retrieve search results */ #define BT_GETSEARCH(IP, LEAF, BN, MP, TYPE, P, INDEX, ROOT)\ {\ BN = (LEAF)->bn;\ MP = (LEAF)->mp;\ if (BN)\ P = (TYPE *)MP->data;\ else\ P = (TYPE *)&JFS_IP(IP)->ROOT;\ INDEX = (LEAF)->index;\ } /* put the page buffer of search */ #define BT_PUTSEARCH(BTSTACK)\ {\ if (! BT_IS_ROOT((BTSTACK)->top->mp))\ release_metapage((BTSTACK)->top->mp);\ } #endif /* _H_JFS_BTREE */

Overall Contributors

PersonTokensPropCommitsCommitProp
dave kleikampdave kleikamp31398.74%583.33%
andrew mortonandrew morton41.26%116.67%
Total317100.00%6100.00%
Directory: fs/jfs
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