fs/xfs/libxfs/xfs_da_btree.h - linux - Git at Google

 /*
  * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
  * Copyright (c) 2013 Red Hat, Inc.
  * All Rights Reserved.
  *
  * 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.
  *
  * This program is distributed in the hope that it would 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 the Free Software Foundation,
  * Inc.,  51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
  */
 #ifndef __XFS_DA_BTREE_H__
 #define	__XFS_DA_BTREE_H__

 struct xfs_defer_ops;
 struct xfs_inode;
 struct xfs_trans;
 struct zone;
 struct xfs_dir_ops;

 /*
  * Directory/attribute geometry information. There will be one of these for each
  * data fork type, and it will be passed around via the xfs_da_args. Global
  * structures will be attached to the xfs_mount.
  */
 struct xfs_da_geometry {
 	int		blksize;	/* da block size in bytes */
 	int		fsbcount;	/* da block size in filesystem blocks */
 	uint8_t		fsblog;		/* log2 of _filesystem_ block size */
 	uint8_t		blklog;		/* log2 of da block size */
 	uint		node_ents;	/* # of entries in a danode */
 	int		magicpct;	/* 37% of block size in bytes */
 	xfs_dablk_t	datablk;	/* blockno of dir data v2 */
 	xfs_dablk_t	leafblk;	/* blockno of leaf data v2 */
 	xfs_dablk_t	freeblk;	/* blockno of free data v2 */
 };

 /*========================================================================
  * Btree searching and modification structure definitions.
  *========================================================================*/

 /*
  * Search comparison results
  */
 enum xfs_dacmp {
 	XFS_CMP_DIFFERENT,	/* names are completely different */
 	XFS_CMP_EXACT,		/* names are exactly the same */
 	XFS_CMP_CASE		/* names are same but differ in case */
 };

 /*
  * Structure to ease passing around component names.
  */
 typedef struct xfs_da_args {
 	struct xfs_da_geometry *geo;	/* da block geometry */
 	const __uint8_t	*name;		/* string (maybe not NULL terminated) */
 	int		namelen;	/* length of string (maybe no NULL) */
 	__uint8_t	filetype;	/* filetype of inode for directories */
 	__uint8_t	*value;		/* set of bytes (maybe contain NULLs) */
 	int		valuelen;	/* length of value */
 	int		flags;		/* argument flags (eg: ATTR_NOCREATE) */
 	xfs_dahash_t	hashval;	/* hash value of name */
 	xfs_ino_t	inumber;	/* input/output inode number */
 	struct xfs_inode *dp;		/* directory inode to manipulate */
 	xfs_fsblock_t	*firstblock;	/* ptr to firstblock for bmap calls */
 	struct xfs_defer_ops *dfops;	/* ptr to freelist for bmap_finish */
 	struct xfs_trans *trans;	/* current trans (changes over time) */
 	xfs_extlen_t	total;		/* total blocks needed, for 1st bmap */
 	int		whichfork;	/* data or attribute fork */
 	xfs_dablk_t	blkno;		/* blkno of attr leaf of interest */
 	int		index;		/* index of attr of interest in blk */
 	xfs_dablk_t	rmtblkno;	/* remote attr value starting blkno */
 	int		rmtblkcnt;	/* remote attr value block count */
 	int		rmtvaluelen;	/* remote attr value length in bytes */
 	xfs_dablk_t	blkno2;		/* blkno of 2nd attr leaf of interest */
 	int		index2;		/* index of 2nd attr in blk */
 	xfs_dablk_t	rmtblkno2;	/* remote attr value starting blkno */
 	int		rmtblkcnt2;	/* remote attr value block count */
 	int		rmtvaluelen2;	/* remote attr value length in bytes */
 	int		op_flags;	/* operation flags */
 	enum xfs_dacmp	cmpresult;	/* name compare result for lookups */
 } xfs_da_args_t;

 /*
  * Operation flags:
  */
 #define XFS_DA_OP_JUSTCHECK	0x0001	/* check for ok with no space */
 #define XFS_DA_OP_RENAME	0x0002	/* this is an atomic rename op */
 #define XFS_DA_OP_ADDNAME	0x0004	/* this is an add operation */
 #define XFS_DA_OP_OKNOENT	0x0008	/* lookup/add op, ENOENT ok, else die */
 #define XFS_DA_OP_CILOOKUP	0x0010	/* lookup to return CI name if found */

 #define XFS_DA_OP_FLAGS \
 	{ XFS_DA_OP_JUSTCHECK,	"JUSTCHECK" }, \
 	{ XFS_DA_OP_RENAME,	"RENAME" }, \
 	{ XFS_DA_OP_ADDNAME,	"ADDNAME" }, \
 	{ XFS_DA_OP_OKNOENT,	"OKNOENT" }, \
 	{ XFS_DA_OP_CILOOKUP,	"CILOOKUP" }

 /*
  * Storage for holding state during Btree searches and split/join ops.
  *
  * Only need space for 5 intermediate nodes.  With a minimum of 62-way
  * fanout to the Btree, we can support over 900 million directory blocks,
  * which is slightly more than enough.
  */
 typedef struct xfs_da_state_blk {
 	struct xfs_buf	*bp;		/* buffer containing block */
 	xfs_dablk_t	blkno;		/* filesystem blkno of buffer */
 	xfs_daddr_t	disk_blkno;	/* on-disk blkno (in BBs) of buffer */
 	int		index;		/* relevant index into block */
 	xfs_dahash_t	hashval;	/* last hash value in block */
 	int		magic;		/* blk's magic number, ie: blk type */
 } xfs_da_state_blk_t;

 typedef struct xfs_da_state_path {
 	int			active;		/* number of active levels */
 	xfs_da_state_blk_t	blk[XFS_DA_NODE_MAXDEPTH];
 } xfs_da_state_path_t;

 typedef struct xfs_da_state {
 	xfs_da_args_t		*args;		/* filename arguments */
 	struct xfs_mount	*mp;		/* filesystem mount point */
 	xfs_da_state_path_t	path;		/* search/split paths */
 	xfs_da_state_path_t	altpath;	/* alternate path for join */
 	unsigned char		inleaf;		/* insert into 1->lf, 0->splf */
 	unsigned char		extravalid;	/* T/F: extrablk is in use */
 	unsigned char		extraafter;	/* T/F: extrablk is after new */
 	xfs_da_state_blk_t	extrablk;	/* for double-splits on leaves */
 						/* for dirv2 extrablk is data */
 } xfs_da_state_t;

 /*
  * Utility macros to aid in logging changed structure fields.
  */
 #define XFS_DA_LOGOFF(BASE, ADDR)	((char *)(ADDR) - (char *)(BASE))
 #define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)	\
 		(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
 		(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)

 /*
  * Name ops for directory and/or attr name operations
  */
 struct xfs_nameops {
 	xfs_dahash_t	(*hashname)(struct xfs_name *);
 	enum xfs_dacmp	(*compname)(struct xfs_da_args *,
 					const unsigned char *, int);
 };


 /*========================================================================
  * Function prototypes.
  *========================================================================*/

 /*
  * Routines used for growing the Btree.
  */
 int	xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
 			    int level, struct xfs_buf **bpp, int whichfork);
 int	xfs_da3_split(xfs_da_state_t *state);

 /*
  * Routines used for shrinking the Btree.
  */
 int	xfs_da3_join(xfs_da_state_t *state);
 void	xfs_da3_fixhashpath(struct xfs_da_state *state,
 			    struct xfs_da_state_path *path_to_to_fix);

 /*
  * Routines used for finding things in the Btree.
  */
 int	xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
 int	xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
 					 int forward, int release, int *result);
 /*
  * Utility routines.
  */
 int	xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
 				       xfs_da_state_blk_t *new_blk);
 int	xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
 			 xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			 struct xfs_buf **bpp, int which_fork);

 /*
  * Utility routines.
  */
 int	xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
 int	xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
 			      int count);
 int	xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 			      xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			      struct xfs_buf **bp, int whichfork);
 int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
 			       xfs_dablk_t bno, xfs_daddr_t mappedbno,
 			       struct xfs_buf **bpp, int whichfork,
 			       const struct xfs_buf_ops *ops);
 xfs_daddr_t	xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
 				xfs_daddr_t mapped_bno, int whichfork,
 				const struct xfs_buf_ops *ops);
 int	xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
 					  struct xfs_buf *dead_buf);

 uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
 enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
 				const unsigned char *name, int len);


 xfs_da_state_t *xfs_da_state_alloc(void);
 void xfs_da_state_free(xfs_da_state_t *state);

 extern struct kmem_zone *xfs_da_state_zone;
 extern const struct xfs_nameops xfs_default_nameops;

 #endif	/* __XFS_DA_BTREE_H__ */
	/*
	* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
	* Copyright (c) 2013 Red Hat, Inc.
	* All Rights Reserved.
	*
	* 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.
	*
	* This program is distributed in the hope that it would 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 the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
	*/
	#ifndef __XFS_DA_BTREE_H__
	#define __XFS_DA_BTREE_H__

	struct xfs_defer_ops;
	struct xfs_inode;
	struct xfs_trans;
	struct zone;
	struct xfs_dir_ops;

	/*
	* Directory/attribute geometry information. There will be one of these for each
	* data fork type, and it will be passed around via the xfs_da_args. Global
	* structures will be attached to the xfs_mount.
	*/
	struct xfs_da_geometry {
	int blksize; /* da block size in bytes */
	int fsbcount; /* da block size in filesystem blocks */
	uint8_t fsblog; /* log2 of _filesystem_ block size */
	uint8_t blklog; /* log2 of da block size */
	uint node_ents; /* # of entries in a danode */
	int magicpct; /* 37% of block size in bytes */
	xfs_dablk_t datablk; /* blockno of dir data v2 */
	xfs_dablk_t leafblk; /* blockno of leaf data v2 */
	xfs_dablk_t freeblk; /* blockno of free data v2 */
	};

	/*========================================================================
	* Btree searching and modification structure definitions.
	========================================================================/

	/*
	* Search comparison results
	*/
	enum xfs_dacmp {
	XFS_CMP_DIFFERENT, /* names are completely different */
	XFS_CMP_EXACT, /* names are exactly the same */
	XFS_CMP_CASE /* names are same but differ in case */
	};

	/*
	* Structure to ease passing around component names.
	*/
	typedef struct xfs_da_args {
	struct xfs_da_geometry geo; / da block geometry */
	const __uint8_t name; / string (maybe not NULL terminated) */
	int namelen; /* length of string (maybe no NULL) */
	__uint8_t filetype; /* filetype of inode for directories */
	__uint8_t value; / set of bytes (maybe contain NULLs) */
	int valuelen; /* length of value */
	int flags; /* argument flags (eg: ATTR_NOCREATE) */
	xfs_dahash_t hashval; /* hash value of name */
	xfs_ino_t inumber; /* input/output inode number */
	struct xfs_inode dp; / directory inode to manipulate */
	xfs_fsblock_t firstblock; / ptr to firstblock for bmap calls */
	struct xfs_defer_ops dfops; / ptr to freelist for bmap_finish */
	struct xfs_trans trans; / current trans (changes over time) */
	xfs_extlen_t total; /* total blocks needed, for 1st bmap */
	int whichfork; /* data or attribute fork */
	xfs_dablk_t blkno; /* blkno of attr leaf of interest */
	int index; /* index of attr of interest in blk */
	xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
	int rmtblkcnt; /* remote attr value block count */
	int rmtvaluelen; /* remote attr value length in bytes */
	xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
	int index2; /* index of 2nd attr in blk */
	xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
	int rmtblkcnt2; /* remote attr value block count */
	int rmtvaluelen2; /* remote attr value length in bytes */
	int op_flags; /* operation flags */
	enum xfs_dacmp cmpresult; /* name compare result for lookups */
	} xfs_da_args_t;

	/*
	* Operation flags:
	*/
	#define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */
	#define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */
	#define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
	#define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
	#define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */

	#define XFS_DA_OP_FLAGS \
	{ XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
	{ XFS_DA_OP_RENAME, "RENAME" }, \
	{ XFS_DA_OP_ADDNAME, "ADDNAME" }, \
	{ XFS_DA_OP_OKNOENT, "OKNOENT" }, \
	{ XFS_DA_OP_CILOOKUP, "CILOOKUP" }

	/*
	* Storage for holding state during Btree searches and split/join ops.
	*
	* Only need space for 5 intermediate nodes. With a minimum of 62-way
	* fanout to the Btree, we can support over 900 million directory blocks,
	* which is slightly more than enough.
	*/
	typedef struct xfs_da_state_blk {
	struct xfs_buf bp; / buffer containing block */
	xfs_dablk_t blkno; /* filesystem blkno of buffer */
	xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
	int index; /* relevant index into block */
	xfs_dahash_t hashval; /* last hash value in block */
	int magic; /* blk's magic number, ie: blk type */
	} xfs_da_state_blk_t;

	typedef struct xfs_da_state_path {
	int active; /* number of active levels */
	xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
	} xfs_da_state_path_t;

	typedef struct xfs_da_state {
	xfs_da_args_t args; / filename arguments */
	struct xfs_mount mp; / filesystem mount point */
	xfs_da_state_path_t path; /* search/split paths */
	xfs_da_state_path_t altpath; /* alternate path for join */
	unsigned char inleaf; /* insert into 1->lf, 0->splf */
	unsigned char extravalid; /* T/F: extrablk is in use */
	unsigned char extraafter; /* T/F: extrablk is after new */
	xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
	/* for dirv2 extrablk is data */
	} xfs_da_state_t;

	/*
	* Utility macros to aid in logging changed structure fields.
	*/
	#define XFS_DA_LOGOFF(BASE, ADDR) ((char )(ADDR) - (char )(BASE))
	#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
	(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
	(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)

	/*
	* Name ops for directory and/or attr name operations
	*/
	struct xfs_nameops {
	xfs_dahash_t (hashname)(struct xfs_name );
	enum xfs_dacmp (compname)(struct xfs_da_args ,
	const unsigned char *, int);
	};


	/*========================================================================
	* Function prototypes.
	========================================================================/

	/*
	* Routines used for growing the Btree.
	*/
	int xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
	int level, struct xfs_buf **bpp, int whichfork);
	int xfs_da3_split(xfs_da_state_t *state);

	/*
	* Routines used for shrinking the Btree.
	*/
	int xfs_da3_join(xfs_da_state_t *state);
	void xfs_da3_fixhashpath(struct xfs_da_state *state,
	struct xfs_da_state_path *path_to_to_fix);

	/*
	* Routines used for finding things in the Btree.
	*/
	int xfs_da3_node_lookup_int(xfs_da_state_t state, int result);
	int xfs_da3_path_shift(xfs_da_state_t state, xfs_da_state_path_t path,
	int forward, int release, int *result);
	/*
	* Utility routines.
	*/
	int xfs_da3_blk_link(xfs_da_state_t state, xfs_da_state_blk_t old_blk,
	xfs_da_state_blk_t *new_blk);
	int xfs_da3_node_read(struct xfs_trans tp, struct xfs_inode dp,
	xfs_dablk_t bno, xfs_daddr_t mappedbno,
	struct xfs_buf **bpp, int which_fork);

	/*
	* Utility routines.
	*/
	int xfs_da_grow_inode(xfs_da_args_t args, xfs_dablk_t new_blkno);
	int xfs_da_grow_inode_int(struct xfs_da_args args, xfs_fileoff_t bno,
	int count);
	int xfs_da_get_buf(struct xfs_trans trans, struct xfs_inode dp,
	xfs_dablk_t bno, xfs_daddr_t mappedbno,
	struct xfs_buf **bp, int whichfork);
	int xfs_da_read_buf(struct xfs_trans trans, struct xfs_inode dp,
	xfs_dablk_t bno, xfs_daddr_t mappedbno,
	struct xfs_buf **bpp, int whichfork,
	const struct xfs_buf_ops *ops);
	xfs_daddr_t xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
	xfs_daddr_t mapped_bno, int whichfork,
	const struct xfs_buf_ops *ops);
	int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
	struct xfs_buf *dead_buf);

	uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
	enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
	const unsigned char *name, int len);


	xfs_da_state_t *xfs_da_state_alloc(void);
	void xfs_da_state_free(xfs_da_state_t *state);

	extern struct kmem_zone *xfs_da_state_zone;
	extern const struct xfs_nameops xfs_default_nameops;

	#endif /* __XFS_DA_BTREE_H__ */