xref: /freebsd/sys/fs/unionfs/union.h (revision 40a8ac8f62b535d30349faf28cf47106b7041b83)
1 /*-
2  * Copyright (c) 1994 The Regents of the University of California.
3  * Copyright (c) 1994 Jan-Simon Pendry.
4  * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
5  * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
6  * All rights reserved.
7  *
8  * This code is derived from software donated to Berkeley by
9  * Jan-Simon Pendry.
10  *
11  * Redistribution and use in source and binary forms, with or without
12  * modification, are permitted provided that the following conditions
13  * are met:
14  * 1. Redistributions of source code must retain the above copyright
15  *    notice, this list of conditions and the following disclaimer.
16  * 2. Redistributions in binary form must reproduce the above copyright
17  *    notice, this list of conditions and the following disclaimer in the
18  *    documentation and/or other materials provided with the distribution.
19  * 4. Neither the name of the University nor the names of its contributors
20  *    may be used to endorse or promote products derived from this software
21  *    without specific prior written permission.
22  *
23  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
24  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
25  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
26  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
27  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
28  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
29  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
30  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
31  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
32  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
33  * SUCH DAMAGE.
34  *
35  *	@(#)union.h	8.9 (Berkeley) 12/10/94
36  * $FreeBSD$
37  */
38 
39 #ifdef _KERNEL
40 
41 /* copy method of attr from lower to upper */
42 typedef enum _unionfs_copymode {
43 	UNIONFS_TRADITIONAL = 0,
44 	UNIONFS_TRANSPARENT,
45 	UNIONFS_MASQUERADE
46 } unionfs_copymode;
47 
48 /* whiteout policy of upper layer */
49 typedef enum _unionfs_whitemode {
50        UNIONFS_WHITE_ALWAYS = 0,
51        UNIONFS_WHITE_WHENNEEDED
52 } unionfs_whitemode;
53 
54 struct unionfs_mount {
55 	struct vnode   *um_lowervp;	/* VREFed once */
56 	struct vnode   *um_uppervp;	/* VREFed once */
57 	struct vnode   *um_rootvp;	/* ROOT vnode */
58 	unionfs_copymode um_copymode;
59 	unionfs_whitemode um_whitemode;
60 	uid_t		um_uid;
61 	gid_t		um_gid;
62 	u_short		um_udir;
63 	u_short		um_ufile;
64 };
65 
66 /* unionfs status list */
67 struct unionfs_node_status {
68 	LIST_ENTRY(unionfs_node_status) uns_list;	/* Status list */
69 	pid_t		uns_pid;		/* current process id */
70 	int		uns_node_flag;		/* uns flag */
71 	int		uns_lower_opencnt;	/* open count of lower */
72 	int		uns_upper_opencnt;	/* open count of upper */
73 	int		uns_lower_openmode;	/* open mode of lower */
74 	int		uns_readdir_status;	/* read status of readdir */
75 };
76 
77 /* union node status flags */
78 #define	UNS_OPENL_4_READDIR	0x01	/* open lower layer for readdir */
79 
80 /* A cache of vnode references */
81 struct unionfs_node {
82 	struct vnode   *un_lowervp;		/* lower side vnode */
83 	struct vnode   *un_uppervp;		/* upper side vnode */
84 	struct vnode   *un_dvp;			/* parent unionfs vnode */
85 	struct vnode   *un_vnode;		/* Back pointer */
86 	LIST_HEAD(, unionfs_node_status) un_unshead;
87 						/* unionfs status head */
88 	LIST_HEAD(unionfs_node_hashhead, unionfs_node) *un_hashtbl;
89 						/* dir vnode hash table */
90 	LIST_ENTRY(unionfs_node)   un_hash;	/* hash list entry */
91 	u_long		un_hashmask;		/* bit mask */
92 	char           *un_path;		/* path */
93 	int		un_flag;		/* unionfs node flag */
94 };
95 
96 /*
97  * unionfs node flags
98  * It needs the vnode with exclusive lock, when changing the un_flag variable.
99  */
100 #define UNIONFS_OPENEXTL	0x01	/* openextattr (lower) */
101 #define UNIONFS_OPENEXTU	0x02	/* openextattr (upper) */
102 
103 #define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
104 #define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
105 #define	UNIONFSTOV(xp) ((xp)->un_vnode)
106 
107 int unionfs_init(struct vfsconf *vfsp);
108 int unionfs_uninit(struct vfsconf *vfsp);
109 int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
110 void unionfs_noderem(struct vnode *vp, struct thread *td);
111 void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
112 void unionfs_tryrem_node_status(struct unionfs_node *unp, struct unionfs_node_status *unsp);
113 
114 int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td);
115 int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td);
116 void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td);
117 int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
118 int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
119 int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
120 int unionfs_relookup(struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct componentname *cn, struct thread *td, char *path, int pathlen, u_long nameiop);
121 int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
122 int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
123 int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);
124 
125 #ifdef DIAGNOSTIC
126 struct vnode   *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
127 struct vnode   *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
128 #define	UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
129 #define	UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
130 #else
131 #define	UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
132 #define	UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
133 #endif
134 
135 extern struct vop_vector unionfs_vnodeops;
136 
137 #ifdef MALLOC_DECLARE
138 MALLOC_DECLARE(M_UNIONFSNODE);
139 MALLOC_DECLARE(M_UNIONFSPATH);
140 #endif
141 
142 #ifdef UNIONFS_DEBUG
143 #define UNIONFSDEBUG(format, args...) printf(format ,## args)
144 #else
145 #define UNIONFSDEBUG(format, args...)
146 #endif				/* UNIONFS_DEBUG */
147 
148 #endif				/* _KERNEL */
149