xref: /freebsd/sys/fs/unionfs/union.h (revision 5e53a4f90f82c4345f277dd87cc9292f26e04a29)
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 	unionfs_copymode um_copymode;
61 	unionfs_whitemode um_whitemode;
62 	uid_t		um_uid;
63 	gid_t		um_gid;
64 	u_short		um_udir;
65 	u_short		um_ufile;
66 };
67 
68 /* unionfs status list */
69 struct unionfs_node_status {
70 	LIST_ENTRY(unionfs_node_status) uns_list;	/* Status list */
71 	pid_t		uns_pid;		/* current process id */
72 	int		uns_node_flag;		/* uns flag */
73 	int		uns_lower_opencnt;	/* open count of lower */
74 	int		uns_upper_opencnt;	/* open count of upper */
75 	int		uns_lower_openmode;	/* open mode of lower */
76 	int		uns_readdir_status;	/* read status of readdir */
77 };
78 
79 /* union node status flags */
80 #define	UNS_OPENL_4_READDIR	0x01	/* open lower layer for readdir */
81 
82 /* A cache of vnode references */
83 struct unionfs_node {
84 	struct vnode   *un_lowervp;		/* lower side vnode */
85 	struct vnode   *un_uppervp;		/* upper side vnode */
86 	struct vnode   *un_dvp;			/* parent unionfs vnode */
87 	struct vnode   *un_vnode;		/* Back pointer */
88 	LIST_HEAD(, unionfs_node_status) un_unshead;
89 						/* unionfs status head */
90 	LIST_HEAD(unionfs_node_hashhead, unionfs_node) *un_hashtbl;
91 						/* dir vnode hash table */
92 	LIST_ENTRY(unionfs_node)   un_hash;	/* hash list entry */
93 	u_long		un_hashmask;		/* bit mask */
94 	char           *un_path;		/* path */
95 	int		un_flag;		/* unionfs node flag */
96 };
97 
98 /*
99  * unionfs node flags
100  * It needs the vnode with exclusive lock, when changing the un_flag variable.
101  */
102 #define UNIONFS_OPENEXTL	0x01	/* openextattr (lower) */
103 #define UNIONFS_OPENEXTU	0x02	/* openextattr (upper) */
104 
105 #define	MOUNTTOUNIONFSMOUNT(mp) ((struct unionfs_mount *)((mp)->mnt_data))
106 #define	VTOUNIONFS(vp) ((struct unionfs_node *)(vp)->v_data)
107 #define	UNIONFSTOV(xp) ((xp)->un_vnode)
108 
109 int unionfs_init(struct vfsconf *vfsp);
110 int unionfs_uninit(struct vfsconf *vfsp);
111 int unionfs_nodeget(struct mount *mp, struct vnode *uppervp, struct vnode *lowervp, struct vnode *dvp, struct vnode **vpp, struct componentname *cnp, struct thread *td);
112 void unionfs_noderem(struct vnode *vp, struct thread *td);
113 void unionfs_get_node_status(struct unionfs_node *unp, struct thread *td, struct unionfs_node_status **unspp);
114 void unionfs_tryrem_node_status(struct unionfs_node *unp, struct unionfs_node_status *unsp);
115 
116 int unionfs_check_rmdir(struct vnode *vp, struct ucred *cred, struct thread *td);
117 int unionfs_copyfile(struct unionfs_node *unp, int docopy, struct ucred *cred, struct thread *td);
118 void unionfs_create_uppervattr_core(struct unionfs_mount *ump, struct vattr *lva, struct vattr *uva, struct thread *td);
119 int unionfs_create_uppervattr(struct unionfs_mount *ump, struct vnode *lvp, struct vattr *uva, struct ucred *cred, struct thread *td);
120 int unionfs_mkshadowdir(struct unionfs_mount *ump, struct vnode *duvp, struct unionfs_node *unp, struct componentname *cnp, struct thread *td);
121 int unionfs_mkwhiteout(struct vnode *dvp, struct componentname *cnp, struct thread *td, char *path);
122 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);
123 int unionfs_relookup_for_create(struct vnode *dvp, struct componentname *cnp, struct thread *td);
124 int unionfs_relookup_for_delete(struct vnode *dvp, struct componentname *cnp, struct thread *td);
125 int unionfs_relookup_for_rename(struct vnode *dvp, struct componentname *cnp, struct thread *td);
126 
127 #ifdef DIAGNOSTIC
128 struct vnode   *unionfs_checklowervp(struct vnode *vp, char *fil, int lno);
129 struct vnode   *unionfs_checkuppervp(struct vnode *vp, char *fil, int lno);
130 #define	UNIONFSVPTOLOWERVP(vp) unionfs_checklowervp((vp), __FILE__, __LINE__)
131 #define	UNIONFSVPTOUPPERVP(vp) unionfs_checkuppervp((vp), __FILE__, __LINE__)
132 #else
133 #define	UNIONFSVPTOLOWERVP(vp) (VTOUNIONFS(vp)->un_lowervp)
134 #define	UNIONFSVPTOUPPERVP(vp) (VTOUNIONFS(vp)->un_uppervp)
135 #endif
136 
137 extern struct vop_vector unionfs_vnodeops;
138 
139 #ifdef MALLOC_DECLARE
140 MALLOC_DECLARE(M_UNIONFSNODE);
141 MALLOC_DECLARE(M_UNIONFSPATH);
142 #endif
143 
144 #ifdef UNIONFS_DEBUG
145 #define UNIONFSDEBUG(format, args...) printf(format ,## args)
146 #else
147 #define UNIONFSDEBUG(format, args...)
148 #endif				/* UNIONFS_DEBUG */
149 
150 #endif				/* _KERNEL */
151