1/*
  2 * Copyright (c) 2000,2002,2005 Silicon Graphics, Inc.
  3 * All Rights Reserved.
  4 *
  5 * This program is free software; you can redistribute it and/or
  6 * modify it under the terms of the GNU General Public License as
  7 * published by the Free Software Foundation.
  8 *
  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.
 13 *
 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
 17 */
 18#ifndef __XFS_DA_BTREE_H__
 19#define	__XFS_DA_BTREE_H__
 20
 21struct xfs_buf;
 22struct xfs_bmap_free;
 23struct xfs_inode;
 24struct xfs_mount;
 25struct xfs_trans;
 26struct 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 *
 35 * Is is used to manage a doubly linked list of all blocks at the same
 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 */
 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
 43typedef struct xfs_da_blkinfo {
 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 */
 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
 61typedef struct xfs_da_intnode {
 62	struct xfs_da_node_hdr {	/* constant-structure header block */
 63		xfs_da_blkinfo_t info;	/* block type, links, etc. */
 64		__be16	count;		/* count of active entries */
 65		__be16	level;		/* level above leaves (leaf == 0) */
 66	} hdr;
 67	struct xfs_da_node_entry {
 68		__be32	hashval;	/* hash value for this descendant */
 69		__be32	before;		/* Btree block before this key */
 70	} btree[1];			/* variable sized array of keys */
 71} xfs_da_intnode_t;
 72typedef struct xfs_da_node_hdr xfs_da_node_hdr_t;
 73typedef struct xfs_da_node_entry xfs_da_node_entry_t;
 74
 75#define	XFS_LBSIZE(mp)	(mp)->m_sb.sb_blocksize
 76
 77/*========================================================================
 78 * Btree searching and modification structure definitions.
 79 *========================================================================*/
 80
 81/*
 82 * Search comparison results
 83 */
 84enum 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
 90/*
 91 * Structure to ease passing around component names.
 92 */
 93typedef struct xfs_da_args {
 94	const __uint8_t	*name;		/* string (maybe not NULL terminated) */
 95	int		namelen;	/* length of string (maybe no NULL) */
 96	__uint8_t	*value;		/* set of bytes (maybe contain NULLs) */
 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 */
115	int		op_flags;	/* operation flags */
116	enum xfs_dacmp	cmpresult;	/* name compare result for lookups */
117} xfs_da_args_t;
118
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 */
126#define XFS_DA_OP_CILOOKUP	0x0010	/* lookup to return CI name if found */
127
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
135/*
136 * Structure to describe buffer(s) for a block.
137 * This is needed in the directory version 2 format case, when
138 * multiple non-contiguous fsblocks might be needed to cover one
139 * logical directory block.
140 * If the buffer count is 1 then the data pointer points to the
141 * same place as the b_addr field for the buffer, else to kmem_alloced memory.
142 */
143typedef struct xfs_dabuf {
144	int		nbuf;		/* number of buffer pointers present */
145	short		dirty;		/* data needs to be copied back */
146	short		bbcount;	/* how large is data in bbs */
147	void		*data;		/* pointer for buffers' data */
148	struct xfs_buf	*bps[1];	/* actually nbuf of these */
149} xfs_dabuf_t;
150#define	XFS_DA_BUF_SIZE(n)	\
151	(sizeof(xfs_dabuf_t) + sizeof(struct xfs_buf *) * ((n) - 1))
152
153/*
154 * Storage for holding state during Btree searches and split/join ops.
155 *
156 * Only need space for 5 intermediate nodes.  With a minimum of 62-way
157 * fanout to the Btree, we can support over 900 million directory blocks,
158 * which is slightly more than enough.
159 */
160typedef struct xfs_da_state_blk {
161	xfs_dabuf_t	*bp;		/* buffer containing block */
162	xfs_dablk_t	blkno;		/* filesystem blkno of buffer */
163	xfs_daddr_t	disk_blkno;	/* on-disk blkno (in BBs) of buffer */
164	int		index;		/* relevant index into block */
165	xfs_dahash_t	hashval;	/* last hash value in block */
166	int		magic;		/* blk's magic number, ie: blk type */
167} xfs_da_state_blk_t;
168
169typedef struct xfs_da_state_path {
170	int			active;		/* number of active levels */
171	xfs_da_state_blk_t	blk[XFS_DA_NODE_MAXDEPTH];
172} xfs_da_state_path_t;
173
174typedef struct xfs_da_state {
175	xfs_da_args_t		*args;		/* filename arguments */
176	struct xfs_mount	*mp;		/* filesystem mount point */
177	unsigned int		blocksize;	/* logical block size */
178	unsigned int		node_ents;	/* how many entries in danode */
179	xfs_da_state_path_t	path;		/* search/split paths */
180	xfs_da_state_path_t	altpath;	/* alternate path for join */
181	unsigned char		inleaf;		/* insert into 1->lf, 0->splf */
182	unsigned char		extravalid;	/* T/F: extrablk is in use */
183	unsigned char		extraafter;	/* T/F: extrablk is after new */
184	xfs_da_state_blk_t	extrablk;	/* for double-splits on leaves */
185						/* for dirv2 extrablk is data */
186} xfs_da_state_t;
187
188/*
189 * Utility macros to aid in logging changed structure fields.
190 */
191#define XFS_DA_LOGOFF(BASE, ADDR)	((char *)(ADDR) - (char *)(BASE))
192#define XFS_DA_LOGRANGE(BASE, ADDR, SIZE)	\
193		(uint)(XFS_DA_LOGOFF(BASE, ADDR)), \
194		(uint)(XFS_DA_LOGOFF(BASE, ADDR)+(SIZE)-1)
195
196/*
197 * Name ops for directory and/or attr name operations
198 */
199struct xfs_nameops {
200	xfs_dahash_t	(*hashname)(struct xfs_name *);
201	enum xfs_dacmp	(*compname)(struct xfs_da_args *,
202					const unsigned char *, int);
203};
204
205
206/*========================================================================
207 * Function prototypes.
208 *========================================================================*/
209
210/*
211 * Routines used for growing the Btree.
212 */
213int	xfs_da_node_create(xfs_da_args_t *args, xfs_dablk_t blkno, int level,
214					 xfs_dabuf_t **bpp, int whichfork);
215int	xfs_da_split(xfs_da_state_t *state);
216
217/*
218 * Routines used for shrinking the Btree.
219 */
220int	xfs_da_join(xfs_da_state_t *state);
221void	xfs_da_fixhashpath(xfs_da_state_t *state,
222					  xfs_da_state_path_t *path_to_to_fix);
223
224/*
225 * Routines used for finding things in the Btree.
226 */
227int	xfs_da_node_lookup_int(xfs_da_state_t *state, int *result);
228int	xfs_da_path_shift(xfs_da_state_t *state, xfs_da_state_path_t *path,
229					 int forward, int release, int *result);
230/*
231 * Utility routines.
232 */
233int	xfs_da_blk_link(xfs_da_state_t *state, xfs_da_state_blk_t *old_blk,
234				       xfs_da_state_blk_t *new_blk);
235
236/*
237 * Utility routines.
238 */
239int	xfs_da_grow_inode(xfs_da_args_t *args, xfs_dablk_t *new_blkno);
240int	xfs_da_grow_inode_int(struct xfs_da_args *args, xfs_fileoff_t *bno,
241			      int count);
242int	xfs_da_get_buf(struct xfs_trans *trans, struct xfs_inode *dp,
243			      xfs_dablk_t bno, xfs_daddr_t mappedbno,
244			      xfs_dabuf_t **bp, int whichfork);
245int	xfs_da_read_buf(struct xfs_trans *trans, struct xfs_inode *dp,
246			       xfs_dablk_t bno, xfs_daddr_t mappedbno,
247			       xfs_dabuf_t **bpp, int whichfork);
248xfs_daddr_t	xfs_da_reada_buf(struct xfs_trans *trans, struct xfs_inode *dp,
249			xfs_dablk_t bno, int whichfork);
250int	xfs_da_shrink_inode(xfs_da_args_t *args, xfs_dablk_t dead_blkno,
251					  xfs_dabuf_t *dead_buf);
252
253uint xfs_da_hashname(const __uint8_t *name_string, int name_length);
254enum xfs_dacmp xfs_da_compname(struct xfs_da_args *args,
255				const unsigned char *name, int len);
256
257
258xfs_da_state_t *xfs_da_state_alloc(void);
259void xfs_da_state_free(xfs_da_state_t *state);
260
261void xfs_da_buf_done(xfs_dabuf_t *dabuf);
262void xfs_da_log_buf(struct xfs_trans *tp, xfs_dabuf_t *dabuf, uint first,
263			   uint last);
264void xfs_da_brelse(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
265void xfs_da_binval(struct xfs_trans *tp, xfs_dabuf_t *dabuf);
266xfs_daddr_t xfs_da_blkno(xfs_dabuf_t *dabuf);
267
268extern struct kmem_zone *xfs_da_state_zone;
269extern struct kmem_zone *xfs_dabuf_zone;
270extern const struct xfs_nameops xfs_default_nameops;
271
272#endif	/* __XFS_DA_BTREE_H__ */