[linux.git] / fs / xfs / xfs_da_btree.h

/*
 * Copyright (c) 2000,2002,2005 Silicon Graphics, 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_buf;
struct xfs_bmap_free;
struct xfs_inode;
struct xfs_mount;
struct xfs_trans;
struct zone;

/*========================================================================
 * Directory Structure when greater than XFS_LBSIZE(mp) bytes.
 *========================================================================*/

/*
 * This structure is common to both leaf nodes and non-leaf nodes in the Btree.
 *
 * It is used to manage a doubly linked list of all blocks at the same
 * level in the Btree, and to identify which type of block this is.
 */
#define XFS_DA_NODE_MAGIC	0xfebe	/* magic number: non-leaf blocks */
#define XFS_ATTR_LEAF_MAGIC	0xfbee	/* magic number: attribute leaf blks */
#define	XFS_DIR2_LEAF1_MAGIC	0xd2f1	/* magic number: v2 dirlf single blks */
#define	XFS_DIR2_LEAFN_MAGIC	0xd2ff	/* magic number: v2 dirlf multi blks */

typedef struct xfs_da_blkinfo {
	__be32		forw;			/* previous block in list */
	__be32		back;			/* following block in list */
	__be16		magic;			/* validity check on block */
	__be16		pad;			/* unused */
} xfs_da_blkinfo_t;

/*
 * This is the structure of the root and intermediate nodes in the Btree.
 * The leaf nodes are defined above.
 *
 * Entries are not packed.
 *
 * Since we have duplicate keys, use a binary search but always follow
 * all match in the block, not just the first match found.
 */
#define	XFS_DA_NODE_MAXDEPTH	5	/* max depth of Btree */

typedef struct xfs_da_intnode {
	struct xfs_da_node_hdr {	/* constant-structure header block */
		xfs_da_blkinfo_t info;	/* block type, links, etc. */
		__be16	count;		/* count of active entries */
		__be16	level;		/* level above leaves (leaf == 0) */
	} hdr;
	struct xfs_da_node_entry {
		__be32	hashval;	/* hash value for this descendant */
		__be32	before;		/* Btree block before this key */
	} btree[1];			/* variable sized array of keys */
} xfs_da_intnode_t;
typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
typedef struct xfs_da_node_entry xfs_da_node_entry_t;

#define	XFS_LBSIZE(mp)	(mp)->m_sb.sb_blocksize

/*========================================================================
 * 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 {
	const __uint8_t	*name;		/* string (maybe not NULL terminated) */
	int		namelen;	/* length of string (maybe no NULL) */
	__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_bmap_free *flist;	/* 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 */
	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		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 */
	unsigned int		blocksize;	/* logical block size */
	unsigned int		node_ents;	/* how many entries in danode */
	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_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
					 struct xfs_buf **bpp, int whichfork);
int	xfs_da_split(xfs_da_state_t *state);

/*
 * Routines used for shrinking the Btree.
 */
int	xfs_da_join(xfs_da_state_t *state);
void	xfs_da_fixhashpath(xfs_da_state_t *state,
					  xfs_da_state_path_t *path_to_to_fix);

/*
 * Routines used for finding things in the Btree.
 */
int	xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
int	xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
					 int forward, int release, int *result);
/*
 * Utility routines.
 */
int	xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
				       xfs_da_state_blk_t *new_blk);

/*
 * 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);
xfs_daddr_t	xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
			xfs_dablk_t bno, int whichfork);
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__ */
Commit	Line	Data
1da177e4	1	/*
7b718769 NS	2	* Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
7b718769 NS	3	* All Rights Reserved.
1da177e4	4	*
7b718769 NS	5	* This program is free software; you can redistribute it and/or
7b718769 NS	6	* modify it under the terms of the GNU General Public License as
1da177e4 LT	7	* published by the Free Software Foundation.
1da177e4 LT	8	*
7b718769 NS	9	* This program is distributed in the hope that it would be useful,
	10	* but WITHOUT ANY WARRANTY; without even the implied warranty of
	11	* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	12	* GNU General Public License for more details.
1da177e4	13	*
7b718769 NS	14	* You should have received a copy of the GNU General Public License
	15	* along with this program; if not, write the Free Software Foundation,
	16	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
1da177e4 LT	17	*/
	18	#ifndef __XFS_DA_BTREE_H__
	19	#define __XFS_DA_BTREE_H__
	20
	21	struct xfs_buf;
	22	struct xfs_bmap_free;
	23	struct xfs_inode;
	24	struct xfs_mount;
	25	struct xfs_trans;
	26	struct zone;
	27
	28	/*========================================================================
	29	* Directory Structure when greater than XFS_LBSIZE(mp) bytes.
	30	========================================================================/
	31
	32	/*
	33	* This structure is common to both leaf nodes and non-leaf nodes in the Btree.
	34	*
96ee34be	35	* It is used to manage a doubly linked list of all blocks at the same
1da177e4 LT	36	* level in the Btree, and to identify which type of block this is.
	37	*/
	38	#define XFS_DA_NODE_MAGIC 0xfebe /* magic number: non-leaf blocks */
1da177e4 LT	39	#define XFS_ATTR_LEAF_MAGIC 0xfbee /* magic number: attribute leaf blks */
	40	#define XFS_DIR2_LEAF1_MAGIC 0xd2f1 /* magic number: v2 dirlf single blks */
	41	#define XFS_DIR2_LEAFN_MAGIC 0xd2ff /* magic number: v2 dirlf multi blks */
	42
1da177e4	43	typedef struct xfs_da_blkinfo {
89da0544 NS	44	__be32 forw; /* previous block in list */
	45	__be32 back; /* following block in list */
	46	__be16 magic; /* validity check on block */
	47	__be16 pad; /* unused */
1da177e4 LT	48	} xfs_da_blkinfo_t;
	49
	50	/*
	51	* This is the structure of the root and intermediate nodes in the Btree.
	52	* The leaf nodes are defined above.
	53	*
	54	* Entries are not packed.
	55	*
	56	* Since we have duplicate keys, use a binary search but always follow
	57	* all match in the block, not just the first match found.
	58	*/
	59	#define XFS_DA_NODE_MAXDEPTH 5 /* max depth of Btree */
	60
	61	typedef struct xfs_da_intnode {
	62	struct xfs_da_node_hdr { /* constant-structure header block */
	63	xfs_da_blkinfo_t info; /* block type, links, etc. */
fac80cce NS	64	__be16 count; /* count of active entries */
fac80cce NS	65	__be16 level; /* level above leaves (leaf == 0) */
1da177e4 LT	66	} hdr;
1da177e4 LT	67	struct xfs_da_node_entry {
403432dc NS	68	__be32 hashval; /* hash value for this descendant */
403432dc NS	69	__be32 before; /* Btree block before this key */
1da177e4 LT	70	} btree[1]; /* variable sized array of keys */
	71	} xfs_da_intnode_t;
	72	typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
	73	typedef struct xfs_da_node_entry xfs_da_node_entry_t;
	74
a844f451	75	#define XFS_LBSIZE(mp) (mp)->m_sb.sb_blocksize
1da177e4 LT	76
	77	/*========================================================================
	78	* Btree searching and modification structure definitions.
	79	========================================================================/
	80
5163f95a BN	81	/*
	82	* Search comparison results
	83	*/
	84	enum xfs_dacmp {
	85	XFS_CMP_DIFFERENT, /* names are completely different */
	86	XFS_CMP_EXACT, /* names are exactly the same */
	87	XFS_CMP_CASE /* names are same but differ in case */
	88	};
	89
1da177e4 LT	90	/*
	91	* Structure to ease passing around component names.
	92	*/
	93	typedef struct xfs_da_args {
a5687787	94	const __uint8_t name; / string (maybe not NULL terminated) */
1da177e4	95	int namelen; /* length of string (maybe no NULL) */
a5687787	96	__uint8_t value; / set of bytes (maybe contain NULLs) */
1da177e4 LT	97	int valuelen; /* length of value */
	98	int flags; /* argument flags (eg: ATTR_NOCREATE) */
	99	xfs_dahash_t hashval; /* hash value of name */
	100	xfs_ino_t inumber; /* input/output inode number */
	101	struct xfs_inode dp; / directory inode to manipulate */
	102	xfs_fsblock_t firstblock; / ptr to firstblock for bmap calls */
	103	struct xfs_bmap_free flist; / ptr to freelist for bmap_finish */
	104	struct xfs_trans trans; / current trans (changes over time) */
	105	xfs_extlen_t total; /* total blocks needed, for 1st bmap */
	106	int whichfork; /* data or attribute fork */
	107	xfs_dablk_t blkno; /* blkno of attr leaf of interest */
	108	int index; /* index of attr of interest in blk */
	109	xfs_dablk_t rmtblkno; /* remote attr value starting blkno */
	110	int rmtblkcnt; /* remote attr value block count */
	111	xfs_dablk_t blkno2; /* blkno of 2nd attr leaf of interest */
	112	int index2; /* index of 2nd attr in blk */
	113	xfs_dablk_t rmtblkno2; /* remote attr value starting blkno */
	114	int rmtblkcnt2; /* remote attr value block count */
6a178100	115	int op_flags; /* operation flags */
5163f95a	116	enum xfs_dacmp cmpresult; /* name compare result for lookups */
1da177e4 LT	117	} xfs_da_args_t;
1da177e4 LT	118
6a178100 BN	119	/*
	120	* Operation flags:
	121	*/
	122	#define XFS_DA_OP_JUSTCHECK 0x0001 /* check for ok with no space */
	123	#define XFS_DA_OP_RENAME 0x0002 /* this is an atomic rename op */
	124	#define XFS_DA_OP_ADDNAME 0x0004 /* this is an add operation */
	125	#define XFS_DA_OP_OKNOENT 0x0008 /* lookup/add op, ENOENT ok, else die */
384f3ced	126	#define XFS_DA_OP_CILOOKUP 0x0010 /* lookup to return CI name if found */
6a178100	127
0b1b213f CH	128	#define XFS_DA_OP_FLAGS \
	129	{ XFS_DA_OP_JUSTCHECK, "JUSTCHECK" }, \
	130	{ XFS_DA_OP_RENAME, "RENAME" }, \
	131	{ XFS_DA_OP_ADDNAME, "ADDNAME" }, \
	132	{ XFS_DA_OP_OKNOENT, "OKNOENT" }, \
	133	{ XFS_DA_OP_CILOOKUP, "CILOOKUP" }
	134
1da177e4 LT	135	/*
	136	* Storage for holding state during Btree searches and split/join ops.
	137	*
	138	* Only need space for 5 intermediate nodes. With a minimum of 62-way
	139	* fanout to the Btree, we can support over 900 million directory blocks,
	140	* which is slightly more than enough.
	141	*/
	142	typedef struct xfs_da_state_blk {
1d9025e5	143	struct xfs_buf bp; / buffer containing block */
1da177e4 LT	144	xfs_dablk_t blkno; /* filesystem blkno of buffer */
	145	xfs_daddr_t disk_blkno; /* on-disk blkno (in BBs) of buffer */
	146	int index; /* relevant index into block */
	147	xfs_dahash_t hashval; /* last hash value in block */
	148	int magic; /* blk's magic number, ie: blk type */
	149	} xfs_da_state_blk_t;
	150
	151	typedef struct xfs_da_state_path {
	152	int active; /* number of active levels */
	153	xfs_da_state_blk_t blk[XFS_DA_NODE_MAXDEPTH];
	154	} xfs_da_state_path_t;
	155
	156	typedef struct xfs_da_state {
	157	xfs_da_args_t args; / filename arguments */
	158	struct xfs_mount mp; / filesystem mount point */
	159	unsigned int blocksize; /* logical block size */
	160	unsigned int node_ents; /* how many entries in danode */
	161	xfs_da_state_path_t path; /* search/split paths */
	162	xfs_da_state_path_t altpath; /* alternate path for join */
	163	unsigned char inleaf; /* insert into 1->lf, 0->splf */
	164	unsigned char extravalid; /* T/F: extrablk is in use */
	165	unsigned char extraafter; /* T/F: extrablk is after new */
9da096fd	166	xfs_da_state_blk_t extrablk; /* for double-splits on leaves */
1da177e4 LT	167	/* for dirv2 extrablk is data */
	168	} xfs_da_state_t;
	169
	170	/*
	171	* Utility macros to aid in logging changed structure fields.
	172	*/
	173	#define XFS_DA_LOGOFF(BASE, ADDR) ((char )(ADDR) - (char )(BASE))
	174	#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE) \
	175	(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
	176	(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
	177
5163f95a BN	178	/*
	179	* Name ops for directory and/or attr name operations
	180	*/
	181	struct xfs_nameops {
	182	xfs_dahash_t (hashname)(struct xfs_name );
2bc75421 DC	183	enum xfs_dacmp (compname)(struct xfs_da_args ,
2bc75421 DC	184	const unsigned char *, int);
5163f95a BN	185	};
5163f95a BN	186
1da177e4	187
1da177e4	188	/*========================================================================
847fff5c	189	* Function prototypes.
1da177e4 LT	190	========================================================================/
	191
	192	/*
	193	* Routines used for growing the Btree.
	194	*/
	195	int xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
1d9025e5	196	struct xfs_buf **bpp, int whichfork);
1da177e4 LT	197	int xfs_da_split(xfs_da_state_t *state);
	198
	199	/*
	200	* Routines used for shrinking the Btree.
	201	*/
	202	int xfs_da_join(xfs_da_state_t *state);
	203	void xfs_da_fixhashpath(xfs_da_state_t *state,
	204	xfs_da_state_path_t *path_to_to_fix);
	205
	206	/*
	207	* Routines used for finding things in the Btree.
	208	*/
	209	int xfs_da_node_lookup_int(xfs_da_state_t state, int result);
	210	int xfs_da_path_shift(xfs_da_state_t state, xfs_da_state_path_t path,
	211	int forward, int release, int *result);
	212	/*
	213	* Utility routines.
	214	*/
1da177e4 LT	215	int xfs_da_blk_link(xfs_da_state_t state, xfs_da_state_blk_t old_blk,
	216	xfs_da_state_blk_t *new_blk);
	217
	218	/*
	219	* Utility routines.
	220	*/
	221	int xfs_da_grow_inode(xfs_da_args_t args, xfs_dablk_t new_blkno);
77936d02 CH	222	int xfs_da_grow_inode_int(struct xfs_da_args args, xfs_fileoff_t bno,
77936d02 CH	223	int count);
1da177e4 LT	224	int xfs_da_get_buf(struct xfs_trans trans, struct xfs_inode dp,
1da177e4 LT	225	xfs_dablk_t bno, xfs_daddr_t mappedbno,
1d9025e5	226	struct xfs_buf **bp, int whichfork);
1da177e4 LT	227	int xfs_da_read_buf(struct xfs_trans trans, struct xfs_inode dp,
1da177e4 LT	228	xfs_dablk_t bno, xfs_daddr_t mappedbno,
1d9025e5	229	struct xfs_buf **bpp, int whichfork);
1da177e4 LT	230	xfs_daddr_t xfs_da_reada_buf(struct xfs_trans trans, struct xfs_inode dp,
	231	xfs_dablk_t bno, int whichfork);
	232	int xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
1d9025e5	233	struct xfs_buf *dead_buf);
1da177e4	234
a5687787	235	uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
5163f95a	236	enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
2bc75421	237	const unsigned char *name, int len);
5163f95a BN	238
5163f95a BN	239
1da177e4 LT	240	xfs_da_state_t *xfs_da_state_alloc(void);
1da177e4 LT	241	void xfs_da_state_free(xfs_da_state_t *state);
1da177e4	242
1da177e4	243	extern struct kmem_zone *xfs_da_state_zone;
24418492	244	extern const struct xfs_nameops xfs_default_nameops;
1da177e4 LT	245
1da177e4 LT	246	#endif /* __XFS_DA_BTREE_H__ */