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_DIR_H__
33 #define	__XFS_DIR_H__
34 
35 /*
36  * Large directories are structured around Btrees where all the data
37  * elements are in the leaf nodes.  Filenames are hashed into an int,
38  * then that int is used as the index into the Btree.  Since the hashval
39  * of a filename may not be unique, we may have duplicate keys.  The
40  * internal links in the Btree are logical block offsets into the file.
41  *
42  * Small directories use a different format and are packed as tightly
43  * as possible so as to fit into the literal area of the inode.
44  */
45 
46 /*========================================================================
47  * Function prototypes for the kernel.
48  *========================================================================*/
49 
50 struct uio;
51 struct xfs_bmap_free;
52 struct xfs_da_args;
53 struct xfs_dinode;
54 struct xfs_inode;
55 struct xfs_mount;
56 struct xfs_trans;
57 
58 /*
59  * Directory function types.
60  * Put in structures (xfs_dirops_t) for v1 and v2 directories.
61  */
62 typedef void	(*xfs_dir_mount_t)(struct xfs_mount *mp);
63 typedef int	(*xfs_dir_isempty_t)(struct xfs_inode *dp);
64 typedef int	(*xfs_dir_init_t)(struct xfs_trans *tp,
65 				  struct xfs_inode *dp,
66 				  struct xfs_inode *pdp);
67 typedef int	(*xfs_dir_createname_t)(struct xfs_trans *tp,
68 					struct xfs_inode *dp,
69 					char *name,
70 					int namelen,
71 					xfs_ino_t inum,
72 					xfs_fsblock_t *first,
73 					struct xfs_bmap_free *flist,
74 					xfs_extlen_t total);
75 typedef int	(*xfs_dir_lookup_t)(struct xfs_trans *tp,
76 				    struct xfs_inode *dp,
77 				    char *name,
78 				    int namelen,
79 				    xfs_ino_t *inum);
80 typedef int	(*xfs_dir_removename_t)(struct xfs_trans *tp,
81 					struct xfs_inode *dp,
82 					char *name,
83 					int namelen,
84 					xfs_ino_t ino,
85 					xfs_fsblock_t *first,
86 					struct xfs_bmap_free *flist,
87 					xfs_extlen_t total);
88 typedef int	(*xfs_dir_getdents_t)(struct xfs_trans *tp,
89 				      struct xfs_inode *dp,
90 				      struct uio *uio,
91 				      int *eofp);
92 typedef int	(*xfs_dir_replace_t)(struct xfs_trans *tp,
93 				     struct xfs_inode *dp,
94 				     char *name,
95 				     int namelen,
96 				     xfs_ino_t inum,
97 				     xfs_fsblock_t *first,
98 				     struct xfs_bmap_free *flist,
99 				     xfs_extlen_t total);
100 typedef int	(*xfs_dir_canenter_t)(struct xfs_trans *tp,
101 				      struct xfs_inode *dp,
102 				      char *name,
103 				      int namelen);
104 typedef int	(*xfs_dir_shortform_validate_ondisk_t)(struct xfs_mount *mp,
105 						       struct xfs_dinode *dip);
106 typedef int	(*xfs_dir_shortform_to_single_t)(struct xfs_da_args *args);
107 
108 typedef struct xfs_dirops {
109 	xfs_dir_mount_t				xd_mount;
110 	xfs_dir_isempty_t			xd_isempty;
111 	xfs_dir_init_t				xd_init;
112 	xfs_dir_createname_t			xd_createname;
113 	xfs_dir_lookup_t			xd_lookup;
114 	xfs_dir_removename_t			xd_removename;
115 	xfs_dir_getdents_t			xd_getdents;
116 	xfs_dir_replace_t			xd_replace;
117 	xfs_dir_canenter_t			xd_canenter;
118 	xfs_dir_shortform_validate_ondisk_t	xd_shortform_validate_ondisk;
119 	xfs_dir_shortform_to_single_t		xd_shortform_to_single;
120 } xfs_dirops_t;
121 
122 /*
123  * Overall external interface routines.
124  */
125 void	xfs_dir_startup(void);	/* called exactly once */
126 
127 #define	XFS_DIR_MOUNT(mp)	\
128 	((mp)->m_dirops.xd_mount(mp))
129 #define	XFS_DIR_ISEMPTY(mp,dp)	\
130 	((mp)->m_dirops.xd_isempty(dp))
131 #define	XFS_DIR_INIT(mp,tp,dp,pdp)	\
132 	((mp)->m_dirops.xd_init(tp,dp,pdp))
133 #define	XFS_DIR_CREATENAME(mp,tp,dp,name,namelen,inum,first,flist,total) \
134 	((mp)->m_dirops.xd_createname(tp,dp,name,namelen,inum,first,flist,\
135 				      total))
136 #define	XFS_DIR_LOOKUP(mp,tp,dp,name,namelen,inum)	\
137 	((mp)->m_dirops.xd_lookup(tp,dp,name,namelen,inum))
138 #define	XFS_DIR_REMOVENAME(mp,tp,dp,name,namelen,ino,first,flist,total)	\
139 	((mp)->m_dirops.xd_removename(tp,dp,name,namelen,ino,first,flist,total))
140 #define	XFS_DIR_GETDENTS(mp,tp,dp,uio,eofp)	\
141 	((mp)->m_dirops.xd_getdents(tp,dp,uio,eofp))
142 #define	XFS_DIR_REPLACE(mp,tp,dp,name,namelen,inum,first,flist,total)	\
143 	((mp)->m_dirops.xd_replace(tp,dp,name,namelen,inum,first,flist,total))
144 #define	XFS_DIR_CANENTER(mp,tp,dp,name,namelen)	\
145 	((mp)->m_dirops.xd_canenter(tp,dp,name,namelen))
146 #define	XFS_DIR_SHORTFORM_VALIDATE_ONDISK(mp,dip)	\
147 	((mp)->m_dirops.xd_shortform_validate_ondisk(mp,dip))
148 #define	XFS_DIR_SHORTFORM_TO_SINGLE(mp,args)	\
149 	((mp)->m_dirops.xd_shortform_to_single(args))
150 
151 #define	XFS_DIR_IS_V1(mp)	((mp)->m_dirversion == 1)
152 extern xfs_dirops_t xfsv1_dirops;
153 
154 #endif	/* __XFS_DIR_H__ */
155