1 /*
2  * Copyright (c) 2000,2005 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_DIR_H__
19 #define	__XFS_DIR_H__
20 
21 /*
22  * Large directories are structured around Btrees where all the data
23  * elements are in the leaf nodes.  Filenames are hashed into an int,
24  * then that int is used as the index into the Btree.  Since the hashval
25  * of a filename may not be unique, we may have duplicate keys.  The
26  * internal links in the Btree are logical block offsets into the file.
27  *
28  * Small directories use a different format and are packed as tightly
29  * as possible so as to fit into the literal area of the inode.
30  */
31 
32 /*========================================================================
33  * Function prototypes for the kernel.
34  *========================================================================*/
35 
36 struct uio;
37 struct xfs_bmap_free;
38 struct xfs_da_args;
39 struct xfs_dinode;
40 struct xfs_inode;
41 struct xfs_mount;
42 struct xfs_trans;
43 
44 /*
45  * Directory function types.
46  * Put in structures (xfs_dirops_t) for v1 and v2 directories.
47  */
48 typedef void	(*xfs_dir_mount_t)(struct xfs_mount *mp);
49 typedef int	(*xfs_dir_isempty_t)(struct xfs_inode *dp);
50 typedef int	(*xfs_dir_init_t)(struct xfs_trans *tp,
51 				  struct xfs_inode *dp,
52 				  struct xfs_inode *pdp);
53 typedef int	(*xfs_dir_createname_t)(struct xfs_trans *tp,
54 					struct xfs_inode *dp,
55 					char *name,
56 					int namelen,
57 					xfs_ino_t inum,
58 					xfs_fsblock_t *first,
59 					struct xfs_bmap_free *flist,
60 					xfs_extlen_t total);
61 typedef int	(*xfs_dir_lookup_t)(struct xfs_trans *tp,
62 				    struct xfs_inode *dp,
63 				    char *name,
64 				    int namelen,
65 				    xfs_ino_t *inum);
66 typedef int	(*xfs_dir_removename_t)(struct xfs_trans *tp,
67 					struct xfs_inode *dp,
68 					char *name,
69 					int namelen,
70 					xfs_ino_t ino,
71 					xfs_fsblock_t *first,
72 					struct xfs_bmap_free *flist,
73 					xfs_extlen_t total);
74 typedef int	(*xfs_dir_getdents_t)(struct xfs_trans *tp,
75 				      struct xfs_inode *dp,
76 				      struct uio *uio,
77 				      int *eofp);
78 typedef int	(*xfs_dir_replace_t)(struct xfs_trans *tp,
79 				     struct xfs_inode *dp,
80 				     char *name,
81 				     int namelen,
82 				     xfs_ino_t inum,
83 				     xfs_fsblock_t *first,
84 				     struct xfs_bmap_free *flist,
85 				     xfs_extlen_t total);
86 typedef int	(*xfs_dir_canenter_t)(struct xfs_trans *tp,
87 				      struct xfs_inode *dp,
88 				      char *name,
89 				      int namelen);
90 typedef int	(*xfs_dir_shortform_validate_ondisk_t)(struct xfs_mount *mp,
91 						       struct xfs_dinode *dip);
92 typedef int	(*xfs_dir_shortform_to_single_t)(struct xfs_da_args *args);
93 
94 typedef struct xfs_dirops {
95 	xfs_dir_mount_t				xd_mount;
96 	xfs_dir_isempty_t			xd_isempty;
97 	xfs_dir_init_t				xd_init;
98 	xfs_dir_createname_t			xd_createname;
99 	xfs_dir_lookup_t			xd_lookup;
100 	xfs_dir_removename_t			xd_removename;
101 	xfs_dir_getdents_t			xd_getdents;
102 	xfs_dir_replace_t			xd_replace;
103 	xfs_dir_canenter_t			xd_canenter;
104 	xfs_dir_shortform_validate_ondisk_t	xd_shortform_validate_ondisk;
105 	xfs_dir_shortform_to_single_t		xd_shortform_to_single;
106 } xfs_dirops_t;
107 
108 /*
109  * Overall external interface routines.
110  */
111 void	xfs_dir_startup(void);	/* called exactly once */
112 
113 #define	XFS_DIR_MOUNT(mp)	\
114 	((mp)->m_dirops.xd_mount(mp))
115 #define	XFS_DIR_ISEMPTY(mp,dp)	\
116 	((mp)->m_dirops.xd_isempty(dp))
117 #define	XFS_DIR_INIT(mp,tp,dp,pdp)	\
118 	((mp)->m_dirops.xd_init(tp,dp,pdp))
119 #define	XFS_DIR_CREATENAME(mp,tp,dp,name,namelen,inum,first,flist,total) \
120 	((mp)->m_dirops.xd_createname(tp,dp,name,namelen,inum,first,flist,\
121 				      total))
122 #define	XFS_DIR_LOOKUP(mp,tp,dp,name,namelen,inum)	\
123 	((mp)->m_dirops.xd_lookup(tp,dp,name,namelen,inum))
124 #define	XFS_DIR_REMOVENAME(mp,tp,dp,name,namelen,ino,first,flist,total)	\
125 	((mp)->m_dirops.xd_removename(tp,dp,name,namelen,ino,first,flist,total))
126 #define	XFS_DIR_GETDENTS(mp,tp,dp,uio,eofp)	\
127 	((mp)->m_dirops.xd_getdents(tp,dp,uio,eofp))
128 #define	XFS_DIR_REPLACE(mp,tp,dp,name,namelen,inum,first,flist,total)	\
129 	((mp)->m_dirops.xd_replace(tp,dp,name,namelen,inum,first,flist,total))
130 #define	XFS_DIR_CANENTER(mp,tp,dp,name,namelen)	\
131 	((mp)->m_dirops.xd_canenter(tp,dp,name,namelen))
132 #define	XFS_DIR_SHORTFORM_VALIDATE_ONDISK(mp,dip)	\
133 	((mp)->m_dirops.xd_shortform_validate_ondisk(mp,dip))
134 #define	XFS_DIR_SHORTFORM_TO_SINGLE(mp,args)	\
135 	((mp)->m_dirops.xd_shortform_to_single(args))
136 
137 #define	XFS_DIR_IS_V1(mp)	((mp)->m_dirversion == 1)
138 #define	XFS_DIR_IS_V2(mp)	((mp)->m_dirversion == 2)
139 extern xfs_dirops_t xfsv1_dirops;
140 extern xfs_dirops_t xfsv2_dirops;
141 
142 #endif	/* __XFS_DIR_H__ */
143