1 /*
2  * Copyright (c) 2000 Silicon Graphics, Inc.  All Rights Reserved.
3  *
4  * This program is free software; you can redistribute it and/or modify it
5  * under the terms of version 2 of the GNU General Public License as
6  * published by the Free Software Foundation.
7  *
8  * This program is distributed in the hope that it would be useful, but
9  * WITHOUT ANY WARRANTY; without even the implied warranty of
10  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
11  *
12  * Further, this software is distributed without any warranty that it is
13  * free of the rightful claim of any third person regarding infringement
14  * or the like.  Any license provided herein, whether implied or
15  * otherwise, applies only to this software file.  Patent licenses, if
16  * any, provided herein do not apply to combinations of this program with
17  * other software, or any other product whatsoever.
18  *
19  * You should have received a copy of the GNU General Public License along
20  * with this program; if not, write the Free Software Foundation, Inc., 59
21  * Temple Place - Suite 330, Boston MA 02111-1307, USA.
22  *
23  * Contact information: Silicon Graphics, Inc., 1600 Amphitheatre Pkwy,
24  * Mountain View, CA  94043, or:
25  *
26  * http://www.sgi.com
27  *
28  * For further information regarding this notice, see:
29  *
30  * http://oss.sgi.com/projects/GenInfo/SGIGPLNoticeExplan/
31  */
32 #ifndef __XFS_DIR2_DATA_H__
33 #define	__XFS_DIR2_DATA_H__
34 
35 /*
36  * Directory format 2, data block structures.
37  */
38 
39 struct xfs_dabuf;
40 struct xfs_da_args;
41 struct xfs_inode;
42 struct xfs_trans;
43 
44 /*
45  * Constants.
46  */
47 #define	XFS_DIR2_DATA_MAGIC	0x58443244	/* XD2D: for multiblock dirs */
48 #define	XFS_DIR2_DATA_ALIGN_LOG	3		/* i.e., 8 bytes */
49 #define	XFS_DIR2_DATA_ALIGN	(1 << XFS_DIR2_DATA_ALIGN_LOG)
50 #define	XFS_DIR2_DATA_FREE_TAG	0xffff
51 #define	XFS_DIR2_DATA_FD_COUNT	3
52 
53 /*
54  * Directory address space divided into sections,
55  * spaces separated by 32gb.
56  */
57 #define	XFS_DIR2_SPACE_SIZE	(1ULL << (32 + XFS_DIR2_DATA_ALIGN_LOG))
58 #define	XFS_DIR2_DATA_SPACE	0
59 #define	XFS_DIR2_DATA_OFFSET	(XFS_DIR2_DATA_SPACE * XFS_DIR2_SPACE_SIZE)
60 #define	XFS_DIR2_DATA_FIRSTDB(mp)	\
61 	XFS_DIR2_BYTE_TO_DB(mp, XFS_DIR2_DATA_OFFSET)
62 
63 /*
64  * Offsets of . and .. in data space (always block 0)
65  */
66 #define	XFS_DIR2_DATA_DOT_OFFSET	\
67 	((xfs_dir2_data_aoff_t)sizeof(xfs_dir2_data_hdr_t))
68 #define	XFS_DIR2_DATA_DOTDOT_OFFSET	\
69 	(XFS_DIR2_DATA_DOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(1))
70 #define	XFS_DIR2_DATA_FIRST_OFFSET		\
71 	(XFS_DIR2_DATA_DOTDOT_OFFSET + XFS_DIR2_DATA_ENTSIZE(2))
72 
73 /*
74  * Structures.
75  */
76 
77 /*
78  * Describe a free area in the data block.
79  * The freespace will be formatted as a xfs_dir2_data_unused_t.
80  */
81 typedef struct xfs_dir2_data_free {
82 	xfs_dir2_data_off_t	offset;		/* start of freespace */
83 	xfs_dir2_data_off_t	length;		/* length of freespace */
84 } xfs_dir2_data_free_t;
85 
86 /*
87  * Header for the data blocks.
88  * Always at the beginning of a directory-sized block.
89  * The code knows that XFS_DIR2_DATA_FD_COUNT is 3.
90  */
91 typedef struct xfs_dir2_data_hdr {
92 	__uint32_t		magic;		/* XFS_DIR2_DATA_MAGIC */
93 						/* or XFS_DIR2_BLOCK_MAGIC */
94 	xfs_dir2_data_free_t	bestfree[XFS_DIR2_DATA_FD_COUNT];
95 } xfs_dir2_data_hdr_t;
96 
97 /*
98  * Active entry in a data block.  Aligned to 8 bytes.
99  * Tag appears as the last 2 bytes.
100  */
101 typedef struct xfs_dir2_data_entry {
102 	xfs_ino_t		inumber;	/* inode number */
103 	__uint8_t		namelen;	/* name length */
104 	__uint8_t		name[1];	/* name bytes, no null */
105 						/* variable offset */
106 	xfs_dir2_data_off_t	tag;		/* starting offset of us */
107 } xfs_dir2_data_entry_t;
108 
109 /*
110  * Unused entry in a data block.  Aligned to 8 bytes.
111  * Tag appears as the last 2 bytes.
112  */
113 typedef struct xfs_dir2_data_unused {
114 	__uint16_t		freetag;	/* XFS_DIR2_DATA_FREE_TAG */
115 	xfs_dir2_data_off_t	length;		/* total free length */
116 						/* variable offset */
117 	xfs_dir2_data_off_t	tag;		/* starting offset of us */
118 } xfs_dir2_data_unused_t;
119 
120 typedef union {
121 	xfs_dir2_data_entry_t	entry;
122 	xfs_dir2_data_unused_t	unused;
123 } xfs_dir2_data_union_t;
124 
125 /*
126  * Generic data block structure, for xfs_db.
127  */
128 typedef struct xfs_dir2_data {
129 	xfs_dir2_data_hdr_t	hdr;		/* magic XFS_DIR2_DATA_MAGIC */
130 	xfs_dir2_data_union_t	u[1];
131 } xfs_dir2_data_t;
132 
133 /*
134  * Macros.
135  */
136 
137 /*
138  * Size of a data entry.
139  */
140 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_ENTSIZE)
141 int xfs_dir2_data_entsize(int n);
142 #define XFS_DIR2_DATA_ENTSIZE(n)	xfs_dir2_data_entsize(n)
143 #else
144 #define	XFS_DIR2_DATA_ENTSIZE(n)	\
145 	((int)(roundup(offsetof(xfs_dir2_data_entry_t, name[0]) + (n) + \
146 		 (uint)sizeof(xfs_dir2_data_off_t), XFS_DIR2_DATA_ALIGN)))
147 #endif
148 
149 /*
150  * Pointer to an entry's tag word.
151  */
152 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_ENTRY_TAG_P)
153 xfs_dir2_data_off_t *xfs_dir2_data_entry_tag_p(xfs_dir2_data_entry_t *dep);
154 #define	XFS_DIR2_DATA_ENTRY_TAG_P(dep)	xfs_dir2_data_entry_tag_p(dep)
155 #else
156 #define	XFS_DIR2_DATA_ENTRY_TAG_P(dep)	\
157 	((xfs_dir2_data_off_t *)\
158 	 ((char *)(dep) + XFS_DIR2_DATA_ENTSIZE((dep)->namelen) - \
159 	  (uint)sizeof(xfs_dir2_data_off_t)))
160 #endif
161 
162 /*
163  * Pointer to a freespace's tag word.
164  */
165 #if XFS_WANT_FUNCS || (XFS_WANT_SPACE && XFSSO_XFS_DIR2_DATA_UNUSED_TAG_P)
166 xfs_dir2_data_off_t *xfs_dir2_data_unused_tag_p_arch(
167 	xfs_dir2_data_unused_t *dup, xfs_arch_t arch);
168 #define	XFS_DIR2_DATA_UNUSED_TAG_P_ARCH(dup,arch) \
169 	xfs_dir2_data_unused_tag_p_arch(dup,arch)
170 #else
171 #define	XFS_DIR2_DATA_UNUSED_TAG_P_ARCH(dup,arch)	\
172 	((xfs_dir2_data_off_t *)\
173 	 ((char *)(dup) + INT_GET((dup)->length, arch) \
174 			- (uint)sizeof(xfs_dir2_data_off_t)))
175 #endif
176 
177 /*
178  * Function declarations.
179  */
180 
181 #ifdef DEBUG
182 extern void
183 	xfs_dir2_data_check(struct xfs_inode *dp, struct xfs_dabuf *bp);
184 #else
185 #define	xfs_dir2_data_check(dp,bp)
186 #endif
187 
188 extern xfs_dir2_data_free_t *
189 	xfs_dir2_data_freefind(xfs_dir2_data_t *d,
190 			       xfs_dir2_data_unused_t *dup);
191 
192 extern xfs_dir2_data_free_t *
193 	xfs_dir2_data_freeinsert(xfs_dir2_data_t *d,
194 				 xfs_dir2_data_unused_t *dup, int *loghead);
195 
196 extern void
197 	xfs_dir2_data_freeremove(xfs_dir2_data_t *d,
198 				 xfs_dir2_data_free_t *dfp, int *loghead);
199 
200 extern void
201 	xfs_dir2_data_freescan(struct xfs_mount *mp, xfs_dir2_data_t *d,
202 			       int *loghead, char *aendp);
203 
204 extern int
205 	xfs_dir2_data_init(struct xfs_da_args *args, xfs_dir2_db_t blkno,
206 			   struct xfs_dabuf **bpp);
207 
208 extern void
209 	xfs_dir2_data_log_entry(struct xfs_trans *tp, struct xfs_dabuf *bp,
210 				xfs_dir2_data_entry_t *dep);
211 
212 extern void
213 	xfs_dir2_data_log_header(struct xfs_trans *tp, struct xfs_dabuf *bp);
214 
215 extern void
216 	xfs_dir2_data_log_unused(struct xfs_trans *tp, struct xfs_dabuf *bp,
217 				 xfs_dir2_data_unused_t *dup);
218 
219 extern void
220 	xfs_dir2_data_make_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
221 				xfs_dir2_data_aoff_t offset,
222 				xfs_dir2_data_aoff_t len, int *needlogp,
223 				int *needscanp);
224 
225 extern void
226 	xfs_dir2_data_use_free(struct xfs_trans *tp, struct xfs_dabuf *bp,
227 			       xfs_dir2_data_unused_t *dup,
228 			       xfs_dir2_data_aoff_t offset,
229 			       xfs_dir2_data_aoff_t len, int *needlogp,
230 			       int *needscanp);
231 
232 #endif	/* __XFS_DIR2_DATA_H__ */
233