vfs_mount.c revision 47423 
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 * $Id: vfs_conf.c,v 1.26 1998/09/14 19:56:40 sos Exp $
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 "opt_bootp.h"
55#include "opt_mfs.h"
56
57#include <sys/param.h>		/* dev_t (types.h)*/
58#include <sys/kernel.h>
59#include <sys/systm.h>		/* rootvp*/
60#include <sys/proc.h>		/* curproc*/
61#include <sys/vnode.h>		/* NULLVP*/
62#include <sys/mount.h>		/* struct mount*/
63#include <sys/malloc.h>		/* M_MOUNT*/
64
65/*
66 * GLOBALS
67 */
68
69MALLOC_DEFINE(M_MOUNT, "mount", "vfs mount struct");
70
71/*
72 *  These define the root filesystem, device, and root filesystem type.
73 */
74dev_t rootdevs[] = { NODEV, NODEV };
75char *rootdevnames[2];
76struct vnode *rootvnode;
77char *mountrootfsname;
78#ifdef BOOTP
79extern void bootpc_init __P((void));
80#endif
81
82/*
83 * vfs_init() will set maxvfsconf
84 * to the highest defined type number.
85 */
86int maxvfsconf;
87struct vfsconf *vfsconf;
88
89/*
90 * Common root mount code shared by all filesystems
91 */
92#define ROOTNAME	"root_device"
93
94/*
95 * vfs_mountrootfs
96 *
97 * Common entry point for root mounts
98 *
99 * PARAMETERS:
100 * 		NONE
101 *
102 * RETURNS:	0	Success
103 *		!0	error number (errno.h)
104 *
105 * LOCK STATE:
106 *		ENTRY
107 *			<no locks held>
108 *		EXIT
109 *			<no locks held>
110 *
111 * NOTES:
112 *		This code is currently supported only for use for
113 *		the FFS file system type.  This is a matter of
114 *		fixing the other file systems, not this code!
115 */
116static void
117vfs_mountrootfs(void *unused)
118{
119	struct mount		*mp;
120	int			err;
121	struct proc		*p = curproc;	/* XXX */
122#ifndef MFS_ROOT
123	int			i;
124	dev_t			orootdev;
125#endif
126
127#ifdef BOOTP
128	bootpc_init();
129#endif
130	/*
131	 *  New root mount structure
132	 */
133	if ((err = vfs_rootmountalloc(mountrootfsname, ROOTNAME, &mp))) {
134		printf("error %d: ", err);
135		panic("cannot mount root\n");
136		return ;
137	}
138	mp->mnt_flag		|= MNT_ROOTFS;
139
140	/*
141	 * Attempt the mount
142	 */
143#ifdef	MFS_ROOT
144	err = VFS_MOUNT(mp, NULL, NULL, NULL, p);
145#else
146	err = ENXIO;
147	orootdev = rootdev;
148	if (rootdevs[0] == NODEV)
149		rootdevs[0] = rootdev;
150	for (i = 0; i < sizeof(rootdevs) / sizeof(rootdevs[0]); i++) {
151		if (rootdevs[i] == NODEV)
152			break;
153		rootdev = rootdevs[i];
154		if (rootdev != orootdev) {
155			printf("changing root device to %s\n", rootdevnames[i]);
156			orootdev = rootdev;
157		}
158		strncpy(mp->mnt_stat.f_mntfromname,
159		    rootdevnames[i] ? rootdevnames[i] : ROOTNAME, MNAMELEN - 1);
160		err = VFS_MOUNT(mp, NULL, NULL, NULL, p);
161		if (err != ENXIO)
162			break;
163	}
164#endif
165	if (err) {
166		/*
167		 * XXX should ask the user for the name in some cases.
168		 * Why do we call vfs_unbusy() here and not after ENXIO
169		 * is returned above?
170		 */
171		vfs_unbusy(mp, p);
172		/*
173		 * free mount struct before failing
174		 * (hardly worthwhile with the PANIC eh?)
175		 */
176		free( mp, M_MOUNT);
177		printf("error %d: ", err);
178		panic("cannot mount root (2)\n");
179		return;
180	}
181
182	simple_lock(&mountlist_slock);
183
184	/*
185	 * Add fs to list of mounted file systems
186	 */
187	CIRCLEQ_INSERT_HEAD(&mountlist, mp, mnt_list);
188
189	simple_unlock(&mountlist_slock);
190	vfs_unbusy(mp, p);
191
192	/* root mount, update system time from FS specific data*/
193	inittodr(mp->mnt_time);
194	return;
195}
196
197SYSINIT(mountroot, SI_SUB_MOUNT_ROOT, SI_ORDER_FIRST, vfs_mountrootfs, NULL)
198
199