xref: /freebsd/sys/kern/vfs_mount.c (revision 3e0f6b97b257a96f7275e4442204263e44b16686)
1 /*
2  * Copyright (c) 1989, 1993, 1995
3  *	The Regents of the University of California.  All rights reserved.
4  * Copyright (c) 1995 Artisoft, Inc.  All Rights Reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions
8  * are met:
9  * 1. Redistributions of source code must retain the above copyright
10  *    notice, this list of conditions and the following disclaimer.
11  * 2. Redistributions in binary form must reproduce the above copyright
12  *    notice, this list of conditions and the following disclaimer in the
13  *    documentation and/or other materials provided with the distribution.
14  * 3. All advertising materials mentioning features or use of this software
15  *    must display the following acknowledgement:
16  *	This product includes software developed by the University of
17  *	California, Berkeley and its contributors.
18  * 4. Neither the name of the University nor the names of its contributors
19  *    may be used to endorse or promote products derived from this software
20  *    without specific prior written permission.
21  *
22  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
23  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
24  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
25  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
26  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
27  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
28  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
29  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
30  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
31  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
32  * SUCH DAMAGE.
33  *
34  *	@(#)vfs_conf.c	8.8 (Berkeley) 3/31/94
35  * $FreeBSD$
36  */
37 
38 /*
39  * PURPOSE:	This file abstracts the root mounting interface from
40  *		the per file system semantics for handling mounts,
41  *		the overall intent of which is to move the BSD
42  *		internals dependence out of the FS code, both to
43  *		make the FS code more portable and to free up some
44  *		of the BSD internals so that they may more easily
45  *		be changed.
46  *
47  * NOTE1:	Code is single entry/single exit to aid debugging
48  *		and conversion for kernel multithreading.
49  *
50  * NOTE2:	Code notes lock state in headers on entry and exit
51  *		as an aid to conversion for kernel multithreading
52  *		on SMP reentrancy
53  */
54 #include <sys/param.h>		/* dev_t (types.h)*/
55 #include <sys/systm.h>		/* rootvp*/
56 #include <sys/proc.h>		/* curproc*/
57 #include <sys/vnode.h>		/* NULLVP*/
58 #include <sys/mount.h>		/* struct mount*/
59 #include <sys/malloc.h>		/* M_MOUNT*/
60 
61 /*
62  * GLOBALS
63  */
64 
65 /*
66  *  These define the root filesystem, device, and root filesystem type.
67  */
68 struct mount *rootfs;
69 struct vnode *rootvnode;
70 char *mountrootfsname;
71 
72 /*
73  * vfs_init() will set maxvfsconf
74  * to the highest defined type number.
75  */
76 int maxvfsconf;
77 struct vfsconf *vfsconf;
78 
79 /*
80  * Common root mount code shared by all filesystems
81  */
82 #define ROOTNAME	"root_device"
83 
84 /*
85  * vfs_mountrootfs
86  *
87  * Common entry point for root mounts
88  *
89  * PARAMETERS:
90  *		fsname	name of the filesystem
91  *
92  * RETURNS:	0	Success
93  *		!0	error number (errno.h)
94  *
95  * LOCK STATE:
96  *		ENTRY
97  *			<no locks held>
98  *		EXIT
99  *			<no locks held>
100  *
101  * NOTES:
102  *		This code is currently supported only for use for
103  *		the FFS file system type.  This is a matter of
104  *		fixing the other file systems, not this code!
105  */
106 int
107 vfs_mountrootfs(fsname)
108 	char			*fsname;
109 {
110 	struct mount		*mp;
111 	int			err = 0;
112 	struct proc		*p = curproc;	/* XXX */
113 
114 	/*
115 	 *  New root mount structure
116 	 */
117 	err = vfs_rootmountalloc(fsname, ROOTNAME, &mp);
118 	if (err)
119 		return (err);
120 	mp->mnt_flag		|= MNT_ROOTFS;
121 
122 	/*
123 	 * Attempt the mount
124 	 */
125 	err = VFS_MOUNT(mp, NULL, NULL, NULL, p);
126 	if (err)
127 		goto error_2;
128 
129 	simple_lock(&mountlist_slock);
130 	/* Add fs to list of mounted file systems*/
131 	CIRCLEQ_INSERT_TAIL(&mountlist, mp, mnt_list);
132 	simple_unlock(&mountlist_slock);
133 
134 	vfs_unbusy(mp, p);
135 
136 	/* root mount, update system time from FS specific data*/
137 	inittodr(mp->mnt_time);
138 
139 	goto success;
140 
141 
142 error_2:	/* mount error*/
143 
144 	vfs_unbusy(mp, p);
145 
146 error_1:	/* lock error*/
147 
148 	/* free mount struct before failing*/
149 	free( mp, M_MOUNT);
150 
151 success:
152 	return( err);
153 }
154