aboutsummaryrefslogtreecommitdiff
path: root/fs/xfs/xfs_da_btree.h
blob: e64c6924996f3e68395746a11d189d000f70b3be (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
/*
 * 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.
 *
 * Is 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_DA_MAXHASH	((xfs_dahash_t)-1) /* largest valid hash value */

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

#define	XFS_DA_MAKE_BNOENTRY(mp,bno,entry)	\
	(((bno) << (mp)->m_dircook_elog) | (entry))
#define	XFS_DA_MAKE_COOKIE(mp,bno,entry,hash)	\
	(((xfs_off_t)XFS_DA_MAKE_BNOENTRY(mp, bno, entry) << 32) | (hash))
#define	XFS_DA_COOKIE_HASH(mp,cookie)		((xfs_dahash_t)cookie)
#define	XFS_DA_COOKIE_BNO(mp,cookie)		\
	((((xfs_off_t)(cookie) >> 31) == -1LL ? \
		(xfs_dablk_t)0 : \
		(xfs_dablk_t)((xfs_off_t)(cookie) >> \
				((mp)->m_dircook_elog + 32))))
#define	XFS_DA_COOKIE_ENTRY(mp,cookie)		\
	((((xfs_off_t)(cookie) >> 31) == -1LL ?	\
		(xfs_dablk_t)0 : \
		(xfs_dablk_t)(((xfs_off_t)(cookie) >> 32) & \
				((1 << (mp)->m_dircook_elog) - 1))))


/*========================================================================
 * 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 uchar_t	*name;		/* string (maybe not NULL terminated) */
	int		namelen;	/* length of string (maybe no NULL) */
	uchar_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 */
	unsigned char	justcheck;	/* T/F: check for ok with no space */
	unsigned char	rename;		/* T/F: this is an atomic rename op */
	unsigned char	addname;	/* T/F: this is an add operation */
	unsigned char	oknoent;	/* T/F: ok to return ENOENT, else die */
	enum xfs_dacmp	cmpresult;	/* name compare result for lookups */
} xfs_da_args_t;

/*
 * Structure to describe buffer(s) for a block.
 * This is needed in the directory version 2 format case, when
 * multiple non-contiguous fsblocks might be needed to cover one
 * logical directory block.
 * If the buffer count is 1 then the data pointer points to the
 * same place as the b_addr field for the buffer, else to kmem_alloced memory.
 */
typedef struct xfs_dabuf {
	int		nbuf;		/* number of buffer pointers present */
	short		dirty;		/* data needs to be copied back */
	short		bbcount;	/* how large is data in bbs */
	void		*data;		/* pointer for buffers' data */
#ifdef XFS_DABUF_DEBUG
	inst_t		*ra;		/* return address of caller to make */
	struct xfs_dabuf *next;		/* next in global chain */
	struct xfs_dabuf *prev;		/* previous in global chain */
	struct xfs_buftarg *target;	/* device for buffer */
	xfs_daddr_t	blkno;		/* daddr first in bps[0] */
#endif
	struct xfs_buf	*bps[1];	/* actually nbuf of these */
} xfs_dabuf_t;
#define	XFS_DA_BUF_SIZE(n)	\
	(sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))

#ifdef XFS_DABUF_DEBUG
extern xfs_dabuf_t	*xfs_dabuf_global_list;
#endif

/*
 * 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 {
	xfs_dabuf_t	*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 leafs */
						/* 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 char *, int);
};


#ifdef __KERNEL__
/*========================================================================
 * Function prototypes for the kernel.
 *========================================================================*/

/*
 * Routines used for growing the Btree.
 */
int	xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
					 xfs_dabuf_t **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_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
			      xfs_dablk_t bno, xfs_daddr_t mappedbno,
			      xfs_dabuf_t **bp, int whichfork);
int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
			       xfs_dablk_t bno, xfs_daddr_t mappedbno,
			       xfs_dabuf_t **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,
					  xfs_dabuf_t *dead_buf);

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


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

void xfs_da_buf_done(xfs_dabuf_t *dabuf);
void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
			   uint last);
void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);

extern struct kmem_zone *xfs_da_state_zone;
extern struct kmem_zone *xfs_dabuf_zone;
#endif	/* __KERNEL__ */

#endif	/* __XFS_DA_BTREE_H__ */