xref: /freebsd/sys/fs/unionfs/union.h (revision 19261079b74319502c6ffa1249920079f0f69a72)
1 /*-
2  * SPDX-License-Identifier: BSD-3-Clause
3  *
4  * Copyright (c) 1994 The Regents of the University of California.
5  * Copyright (c) 1994 Jan-Simon Pendry.
6  * Copyright (c) 2005, 2006 Masanori Ozawa <ozawa@ongs.co.jp>, ONGS Inc.
7  * Copyright (c) 2006 Daichi Goto <daichi@freebsd.org>
8  * All rights reserved.
9  *
10  * This code is derived from software donated to Berkeley by
11  * Jan-Simon Pendry.
12  *
13  * Redistribution and use in source and binary forms, with or without
14  * modification, are permitted provided that the following conditions
15  * are met:
16  * 1. Redistributions of source code must retain the above copyright
17  *    notice, this list of conditions and the following disclaimer.
18  * 2. Redistributions in binary form must reproduce the above copyright
19  *    notice, this list of conditions and the following disclaimer in the
20  *    documentation and/or other materials provided with the distribution.
21  * 3. Neither the name of the University nor the names of its contributors
22  *    may be used to endorse or promote products derived from this software
23  *    without specific prior written permission.
24  *
25  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
26  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
27  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
28  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
29  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
30  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
31  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
32  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
33  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
34  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
35  * SUCH DAMAGE.
36  *
37  *	@(#)union.h	8.9 (Berkeley) 12/10/94
38  * $FreeBSD$
39  */
40 
41 #ifdef _KERNEL
42 
43 /* copy method of attr from lower to upper */
44 typedef enum _unionfs_copymode {
45 	UNIONFS_TRADITIONAL = 0,
46 	UNIONFS_TRANSPARENT,
47 	UNIONFS_MASQUERADE
48 } unionfs_copymode;
49 
50 /* whiteout policy of upper layer */
51 typedef enum _unionfs_whitemode {
52        UNIONFS_WHITE_ALWAYS = 0,
53        UNIONFS_WHITE_WHENNEEDED
54 } unionfs_whitemode;
55 
56 struct unionfs_mount {
57 	struct vnode   *um_lowervp;	/* VREFed once */
58 	struct vnode   *um_uppervp;	/* VREFed once */
59 	struct vnode   *um_rootvp;	/* ROOT vnode */
60 	struct mount_upper_node	um_lower_link;	/* node in lower FS list of uppers */
61 	struct mount_upper_node	um_upper_link;	/* node in upper FS list of uppers */
62 	unionfs_copymode um_copymode;
63 	unionfs_whitemode um_whitemode;
64 	uid_t		um_uid;
65 	gid_t		um_gid;
66 	u_short		um_udir;
67 	u_short		um_ufile;
68 };
69 
70 /* unionfs status list */
71 struct unionfs_node_status {
72 	LIST_ENTRY(unionfs_node_status) uns_list;	/* Status list */
73 	pid_t		uns_pid;		/* current process id */
74 	int		uns_node_flag;		/* uns flag */
75 	int		uns_lower_opencnt;	/* open count of lower */
76 	int		uns_upper_opencnt;	/* open count of upper */
77 	int		uns_lower_openmode;	/* open mode of lower */
78 	int		uns_readdir_status;	/* read status of readdir */
79 };
80 
81 /* union node status flags */
82 #define	UNS_OPENL_4_READDIR	0x01	/* open lower layer for readdir */
83 
84 /* A cache of vnode references */
85 struct unionfs_node {
86 	struct vnode   *un_lowervp;		/* lower side vnode */
87 	struct vnode   *un_uppervp;		/* upper side vnode */
88 	struct vnode   *un_dvp;			/* parent unionfs vnode */
89 	struct vnode   *un_vnode;		/* Back pointer */
90 	LIST_HEAD(, unionfs_node_status) un_unshead;
91 						/* unionfs status head */
92 	LIST_HEAD(unionfs_node_hashhead, unionfs_node) *un_hashtbl;
93 						/* dir vnode hash table */
94 	union {
95 		LIST_ENTRY(unionfs_node) un_hash; /* hash list entry */
96 		STAILQ_ENTRY(unionfs_node) un_rele; /* deferred release list */
97 	};
98 
99 	u_long		un_hashmask;		/* bit mask */
100 	char           *un_path;		/* path */
101 	int		un_pathlen;		/* strlen of path */
102 	int		un_flag;		/* unionfs node flag */
103 };
104 
105 /*
106  * unionfs node flags
107  * It needs the vnode with exclusive lock, when changing the un_flag variable.
108  */
109 #define UNIONFS_OPENEXTL	0x01	/* openextattr (lower) */
110 #define UNIONFS_OPENEXTU	0x02	/* openextattr (upper) */
111 
112 #define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
113 #define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
114 #define	UNIONFSTOV(xp) ((xp)->un_vnode)
115 
116 int	unionfs_init(struct vfsconf *);
117 int	unionfs_uninit(struct vfsconf *);
118 int	unionfs_nodeget(struct mount *, struct vnode *, struct vnode *,
119 	    struct vnode *, struct vnode **, struct componentname *,
120 	    struct thread *);
121 void	unionfs_noderem(struct vnode *, struct thread *);
122 void	unionfs_get_node_status(struct unionfs_node *, struct thread *,
123 	    struct unionfs_node_status **);
124 void	unionfs_tryrem_node_status(struct unionfs_node *,
125 	    struct unionfs_node_status *);
126 int	unionfs_check_rmdir(struct vnode *, struct ucred *, struct thread *td);
127 int	unionfs_copyfile(struct unionfs_node *, int, struct ucred *,
128 	    struct thread *);
129 void	unionfs_create_uppervattr_core(struct unionfs_mount *, struct vattr *,
130 	    struct vattr *, struct thread *);
131 int	unionfs_create_uppervattr(struct unionfs_mount *, struct vnode *,
132 	    struct vattr *, struct ucred *, struct thread *);
133 int	unionfs_mkshadowdir(struct unionfs_mount *, struct vnode *,
134 	    struct unionfs_node *, struct componentname *, struct thread *);
135 int	unionfs_mkwhiteout(struct vnode *, struct componentname *,
136 	    struct thread *, char *, int);
137 int	unionfs_relookup(struct vnode *, struct vnode **,
138 	    struct componentname *, struct componentname *, struct thread *,
139 	    char *, int, u_long);
140 int	unionfs_relookup_for_create(struct vnode *, struct componentname *,
141 	    struct thread *td);
142 int	unionfs_relookup_for_delete(struct vnode *, struct componentname *,
143 	    struct thread *);
144 int	unionfs_relookup_for_rename(struct vnode *, struct componentname *,
145 	    struct thread *td);
146 
147 #ifdef DIAGNOSTIC
148 struct vnode   *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
149 struct vnode   *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
150 #define	UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
151 #define	UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
152 #else
153 #define	UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
154 #define	UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
155 #endif
156 
157 extern struct vop_vector unionfs_vnodeops;
158 
159 #ifdef MALLOC_DECLARE
160 MALLOC_DECLARE(M_UNIONFSNODE);
161 MALLOC_DECLARE(M_UNIONFSPATH);
162 #endif
163 
164 #ifdef UNIONFS_DEBUG
165 #define UNIONFSDEBUG(format, args...) printf(format ,## args)
166 #else
167 #define UNIONFSDEBUG(format, args...)
168 #endif				/* UNIONFS_DEBUG */
169 
170 #endif				/* _KERNEL */
171