1/* SPDX-License-Identifier: GPL-2.0 */
2/*
3 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
4 * Copyright (c) 2013 Red Hat, Inc.
5 * All Rights Reserved.
6 */
7#ifndef __XFS_DA_BTREE_H__
8#define	__XFS_DA_BTREE_H__
9
10struct xfs_inode;
11struct xfs_trans;
12
13/*
14 * Directory/attribute geometry information. There will be one of these for each
15 * data fork type, and it will be passed around via the xfs_da_args. Global
16 * structures will be attached to the xfs_mount.
17 */
18struct xfs_da_geometry {
19	unsigned int	blksize;	/* da block size in bytes */
20	unsigned int	fsbcount;	/* da block size in filesystem blocks */
21	uint8_t		fsblog;		/* log2 of _filesystem_ block size */
22	uint8_t		blklog;		/* log2 of da block size */
23	unsigned int	node_hdr_size;	/* danode header size in bytes */
24	unsigned int	node_ents;	/* # of entries in a danode */
25	unsigned int	magicpct;	/* 37% of block size in bytes */
26	xfs_dablk_t	datablk;	/* blockno of dir data v2 */
27	unsigned int	leaf_hdr_size;	/* dir2 leaf header size */
28	unsigned int	leaf_max_ents;	/* # of entries in dir2 leaf */
29	xfs_dablk_t	leafblk;	/* blockno of leaf data v2 */
30	unsigned int	free_hdr_size;	/* dir2 free header size */
31	unsigned int	free_max_bests;	/* # of bests entries in dir2 free */
32	xfs_dablk_t	freeblk;	/* blockno of free data v2 */
33	xfs_extnum_t	max_extents;	/* Max. extents in corresponding fork */
34
35	xfs_dir2_data_aoff_t data_first_offset;
36	size_t		data_entry_offset;
37};
38
39/*========================================================================
40 * Btree searching and modification structure definitions.
41 *========================================================================*/
42
43/*
44 * Search comparison results
45 */
46enum xfs_dacmp {
47	XFS_CMP_DIFFERENT,	/* names are completely different */
48	XFS_CMP_EXACT,		/* names are exactly the same */
49	XFS_CMP_CASE		/* names are same but differ in case */
50};
51
52/*
53 * Structure to ease passing around component names.
54 */
55typedef struct xfs_da_args {
56	struct xfs_da_geometry *geo;	/* da block geometry */
57	const uint8_t		*name;		/* string (maybe not NULL terminated) */
58	int		namelen;	/* length of string (maybe no NULL) */
59	uint8_t		filetype;	/* filetype of inode for directories */
60	void		*value;		/* set of bytes (maybe contain NULLs) */
61	int		valuelen;	/* length of value */
62	unsigned int	attr_filter;	/* XFS_ATTR_{ROOT,SECURE,INCOMPLETE} */
63	unsigned int	attr_flags;	/* XATTR_{CREATE,REPLACE} */
64	xfs_dahash_t	hashval;	/* hash value of name */
65	xfs_ino_t	inumber;	/* input/output inode number */
66	struct xfs_inode *dp;		/* directory inode to manipulate */
67	struct xfs_trans *trans;	/* current trans (changes over time) */
68	xfs_extlen_t	total;		/* total blocks needed, for 1st bmap */
69	int		whichfork;	/* data or attribute fork */
70	xfs_dablk_t	blkno;		/* blkno of attr leaf of interest */
71	int		index;		/* index of attr of interest in blk */
72	xfs_dablk_t	rmtblkno;	/* remote attr value starting blkno */
73	int		rmtblkcnt;	/* remote attr value block count */
74	int		rmtvaluelen;	/* remote attr value length in bytes */
75	xfs_dablk_t	blkno2;		/* blkno of 2nd attr leaf of interest */
76	int		index2;		/* index of 2nd attr in blk */
77	xfs_dablk_t	rmtblkno2;	/* remote attr value starting blkno */
78	int		rmtblkcnt2;	/* remote attr value block count */
79	int		rmtvaluelen2;	/* remote attr value length in bytes */
80	uint32_t	op_flags;	/* operation flags */
81	enum xfs_dacmp	cmpresult;	/* name compare result for lookups */
82} xfs_da_args_t;
83
84/*
85 * Operation flags:
86 */
87#define XFS_DA_OP_JUSTCHECK	(1u << 0) /* check for ok with no space */
88#define XFS_DA_OP_REPLACE	(1u << 1) /* this is an atomic replace op */
89#define XFS_DA_OP_ADDNAME	(1u << 2) /* this is an add operation */
90#define XFS_DA_OP_OKNOENT	(1u << 3) /* lookup op, ENOENT ok, else die */
91#define XFS_DA_OP_CILOOKUP	(1u << 4) /* lookup returns CI name if found */
92#define XFS_DA_OP_NOTIME	(1u << 5) /* don't update inode timestamps */
93#define XFS_DA_OP_REMOVE	(1u << 6) /* this is a remove operation */
94#define XFS_DA_OP_RECOVERY	(1u << 7) /* Log recovery operation */
95#define XFS_DA_OP_LOGGED	(1u << 8) /* Use intent items to track op */
96
97#define XFS_DA_OP_FLAGS \
98	{ XFS_DA_OP_JUSTCHECK,	"JUSTCHECK" }, \
99	{ XFS_DA_OP_REPLACE,	"REPLACE" }, \
100	{ XFS_DA_OP_ADDNAME,	"ADDNAME" }, \
101	{ XFS_DA_OP_OKNOENT,	"OKNOENT" }, \
102	{ XFS_DA_OP_CILOOKUP,	"CILOOKUP" }, \
103	{ XFS_DA_OP_NOTIME,	"NOTIME" }, \
104	{ XFS_DA_OP_REMOVE,	"REMOVE" }, \
105	{ XFS_DA_OP_RECOVERY,	"RECOVERY" }, \
106	{ XFS_DA_OP_LOGGED,	"LOGGED" }
107
108/*
109 * Storage for holding state during Btree searches and split/join ops.
110 *
111 * Only need space for 5 intermediate nodes.  With a minimum of 62-way
112 * fanout to the Btree, we can support over 900 million directory blocks,
113 * which is slightly more than enough.
114 */
115typedef struct xfs_da_state_blk {
116	struct xfs_buf	*bp;		/* buffer containing block */
117	xfs_dablk_t	blkno;		/* filesystem blkno of buffer */
118	xfs_daddr_t	disk_blkno;	/* on-disk blkno (in BBs) of buffer */
119	int		index;		/* relevant index into block */
120	xfs_dahash_t	hashval;	/* last hash value in block */
121	int		magic;		/* blk's magic number, ie: blk type */
122} xfs_da_state_blk_t;
123
124typedef struct xfs_da_state_path {
125	int			active;		/* number of active levels */
126	xfs_da_state_blk_t	blk[XFS_DA_NODE_MAXDEPTH];
127} xfs_da_state_path_t;
128
129typedef struct xfs_da_state {
130	xfs_da_args_t		*args;		/* filename arguments */
131	struct xfs_mount	*mp;		/* filesystem mount point */
132	xfs_da_state_path_t	path;		/* search/split paths */
133	xfs_da_state_path_t	altpath;	/* alternate path for join */
134	unsigned char		inleaf;		/* insert into 1->lf, 0->splf */
135	unsigned char		extravalid;	/* T/F: extrablk is in use */
136	unsigned char		extraafter;	/* T/F: extrablk is after new */
137	xfs_da_state_blk_t	extrablk;	/* for double-splits on leaves */
138						/* for dirv2 extrablk is data */
139} xfs_da_state_t;
140
141/*
142 * In-core version of the node header to abstract the differences in the v2 and
143 * v3 disk format of the headers. Callers need to convert to/from disk format as
144 * appropriate.
145 */
146struct xfs_da3_icnode_hdr {
147	uint32_t		forw;
148	uint32_t		back;
149	uint16_t		magic;
150	uint16_t		count;
151	uint16_t		level;
152
153	/*
154	 * Pointer to the on-disk format entries, which are behind the
155	 * variable size (v4 vs v5) header in the on-disk block.
156	 */
157	struct xfs_da_node_entry *btree;
158};
159
160/*
161 * Utility macros to aid in logging changed structure fields.
162 */
163#define XFS_DA_LOGOFF(BASE, ADDR)	((char *)(ADDR) - (char *)(BASE))
164#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)	\
165		(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
166		(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
167
168/*========================================================================
169 * Function prototypes.
170 *========================================================================*/
171
172/*
173 * Routines used for growing the Btree.
174 */
175int	xfs_da3_node_create(struct xfs_da_args *args, xfs_dablk_t blkno,
176			    int level, struct xfs_buf **bpp, int whichfork);
177int	xfs_da3_split(xfs_da_state_t *state);
178
179/*
180 * Routines used for shrinking the Btree.
181 */
182int	xfs_da3_join(xfs_da_state_t *state);
183void	xfs_da3_fixhashpath(struct xfs_da_state *state,
184			    struct xfs_da_state_path *path_to_to_fix);
185
186/*
187 * Routines used for finding things in the Btree.
188 */
189int	xfs_da3_node_lookup_int(xfs_da_state_t *state, int *result);
190int	xfs_da3_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
191					 int forward, int release, int *result);
192/*
193 * Utility routines.
194 */
195int	xfs_da3_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
196				       xfs_da_state_blk_t *new_blk);
197int	xfs_da3_node_read(struct xfs_trans *tp, struct xfs_inode *dp,
198			xfs_dablk_t bno, struct xfs_buf **bpp, int whichfork);
199int	xfs_da3_node_read_mapped(struct xfs_trans *tp, struct xfs_inode *dp,
200			xfs_daddr_t mappedbno, struct xfs_buf **bpp,
201			int whichfork);
202
203/*
204 * Utility routines.
205 */
206
207#define XFS_DABUF_MAP_HOLE_OK	(1u << 0)
208
209int	xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
210int	xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
211			      int count);
212int	xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
213		xfs_dablk_t bno, struct xfs_buf **bp, int whichfork);
214int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
215		xfs_dablk_t bno, unsigned int flags, struct xfs_buf **bpp,
216		int whichfork, const struct xfs_buf_ops *ops);
217int	xfs_da_reada_buf(struct xfs_inode *dp, xfs_dablk_t bno,
218		unsigned int flags, int whichfork,
219		const struct xfs_buf_ops *ops);
220int	xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
221					  struct xfs_buf *dead_buf);
222void	xfs_da_buf_copy(struct xfs_buf *dst, struct xfs_buf *src,
223			size_t size);
224
225uint xfs_da_hashname(const uint8_t *name_string, int name_length);
226enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
227				const unsigned char *name, int len);
228
229
230struct xfs_da_state *xfs_da_state_alloc(struct xfs_da_args *args);
231void xfs_da_state_free(xfs_da_state_t *state);
232void xfs_da_state_reset(struct xfs_da_state *state, struct xfs_da_args *args);
233
234void	xfs_da3_node_hdr_from_disk(struct xfs_mount *mp,
235		struct xfs_da3_icnode_hdr *to, struct xfs_da_intnode *from);
236void	xfs_da3_node_hdr_to_disk(struct xfs_mount *mp,
237		struct xfs_da_intnode *to, struct xfs_da3_icnode_hdr *from);
238
239extern struct kmem_cache	*xfs_da_state_cache;
240
241#endif	/* __XFS_DA_BTREE_H__ */
242