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kernfs_vfsops.c revision 1.19
      1 /*	$NetBSD: kernfs_vfsops.c,v 1.19 1994/09/15 03:42:39 mycroft Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993
      5  *	The Regents of the University of California.  All rights reserved.
      6  *
      7  * This code is derived from software donated to Berkeley by
      8  * Jan-Simon Pendry.
      9  *
     10  * Redistribution and use in source and binary forms, with or without
     11  * modification, are permitted provided that the following conditions
     12  * are met:
     13  * 1. Redistributions of source code must retain the above copyright
     14  *    notice, this list of conditions and the following disclaimer.
     15  * 2. Redistributions in binary form must reproduce the above copyright
     16  *    notice, this list of conditions and the following disclaimer in the
     17  *    documentation and/or other materials provided with the distribution.
     18  * 3. All advertising materials mentioning features or use of this software
     19  *    must display the following acknowledgement:
     20  *	This product includes software developed by the University of
     21  *	California, Berkeley and its contributors.
     22  * 4. Neither the name of the University nor the names of its contributors
     23  *    may be used to endorse or promote products derived from this software
     24  *    without specific prior written permission.
     25  *
     26  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
     27  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
     28  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
     29  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
     30  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
     31  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
     32  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
     33  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
     34  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
     35  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
     36  * SUCH DAMAGE.
     37  *
     38  *	@(#)kernfs_vfsops.c	8.5 (Berkeley) 6/15/94
     39  */
     40 
     41 /*
     42  * Kernel params Filesystem
     43  */
     44 
     45 #include <sys/param.h>
     46 #include <sys/systm.h>
     47 #include <sys/conf.h>
     48 #include <sys/types.h>
     49 #include <sys/proc.h>
     50 #include <sys/vnode.h>
     51 #include <sys/mount.h>
     52 #include <sys/namei.h>
     53 #include <sys/malloc.h>
     54 
     55 #include <miscfs/specfs/specdev.h>
     56 #include <miscfs/kernfs/kernfs.h>
     57 
     58 dev_t rrootdev = NODEV;
     59 
     60 kernfs_init()
     61 {
     62 
     63 }
     64 
     65 void
     66 kernfs_get_rrootdev()
     67 {
     68 	static int tried = 0;
     69 	int cmaj;
     70 
     71 	if (tried) {
     72 		/* Already did it once. */
     73 		return;
     74 	}
     75 	tried = 1;
     76 
     77 	if (rootdev == NODEV)
     78 		return;
     79 	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
     80 		rrootdev = makedev(cmaj, minor(rootdev));
     81 		if (chrtoblk(rrootdev) == rootdev)
     82 			return;
     83 	}
     84 	rrootdev = NODEV;
     85 	printf("kernfs_get_rrootdev: no raw root device\n");
     86 }
     87 
     88 /*
     89  * Mount the Kernel params filesystem
     90  */
     91 kernfs_mount(mp, path, data, ndp, p)
     92 	struct mount *mp;
     93 	char *path;
     94 	caddr_t data;
     95 	struct nameidata *ndp;
     96 	struct proc *p;
     97 {
     98 	int error = 0;
     99 	u_int size;
    100 	struct kernfs_mount *fmp;
    101 	struct vnode *rvp;
    102 
    103 #ifdef KERNFS_DIAGNOSTIC
    104 	printf("kernfs_mount(mp = %x)\n", mp);
    105 #endif
    106 
    107 	/*
    108 	 * Update is a no-op
    109 	 */
    110 	if (mp->mnt_flag & MNT_UPDATE)
    111 		return (EOPNOTSUPP);
    112 
    113 	if (error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp))
    114 		return (error);
    115 
    116 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
    117 	    M_MISCFSMNT, M_WAITOK);
    118 	rvp->v_type = VDIR;
    119 	rvp->v_flag |= VROOT;
    120 #ifdef KERNFS_DIAGNOSTIC
    121 	printf("kernfs_mount: root vp = %x\n", rvp);
    122 #endif
    123 	fmp->kf_root = rvp;
    124 	mp->mnt_flag |= MNT_LOCAL;
    125 	mp->mnt_data = (qaddr_t)fmp;
    126 	getnewfsid(mp, makefstype(MOUNT_KERNFS));
    127 
    128 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    129 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
    130 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
    131 	bcopy("kernfs", mp->mnt_stat.f_mntfromname, sizeof("kernfs"));
    132 	(void)kernfs_statfs(mp, &mp->mnt_stat, p);
    133 #ifdef KERNFS_DIAGNOSTIC
    134 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
    135 #endif
    136 
    137 	kernfs_get_rrootdev();
    138 	return (0);
    139 }
    140 
    141 kernfs_start(mp, flags, p)
    142 	struct mount *mp;
    143 	int flags;
    144 	struct proc *p;
    145 {
    146 
    147 	return (0);
    148 }
    149 
    150 kernfs_unmount(mp, mntflags, p)
    151 	struct mount *mp;
    152 	int mntflags;
    153 	struct proc *p;
    154 {
    155 	int error;
    156 	int flags = 0;
    157 	extern int doforce;
    158 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
    159 
    160 #ifdef KERNFS_DIAGNOSTIC
    161 	printf("kernfs_unmount(mp = %x)\n", mp);
    162 #endif
    163 
    164 	if (mntflags & MNT_FORCE) {
    165 		/* kernfs can never be rootfs so don't check for it */
    166 		if (!doforce)
    167 			return (EINVAL);
    168 		flags |= FORCECLOSE;
    169 	}
    170 
    171 	/*
    172 	 * Clear out buffer cache.  I don't think we
    173 	 * ever get anything cached at this level at the
    174 	 * moment, but who knows...
    175 	 */
    176 	if (rootvp->v_usecount > 1)
    177 		return (EBUSY);
    178 #ifdef KERNFS_DIAGNOSTIC
    179 	printf("kernfs_unmount: calling vflush\n");
    180 #endif
    181 	if (error = vflush(mp, rootvp, flags))
    182 		return (error);
    183 
    184 #ifdef KERNFS_DIAGNOSTIC
    185 	vprint("kernfs root", rootvp);
    186 #endif
    187 	/*
    188 	 * Clean out the old root vnode for reuse.
    189 	 */
    190 	vrele(rootvp);
    191 	vgone(rootvp);
    192 	/*
    193 	 * Finally, throw away the kernfs_mount structure
    194 	 */
    195 	free(mp->mnt_data, M_MISCFSMNT);
    196 	mp->mnt_data = 0;
    197 	return (0);
    198 }
    199 
    200 kernfs_root(mp, vpp)
    201 	struct mount *mp;
    202 	struct vnode **vpp;
    203 {
    204 	struct vnode *vp;
    205 
    206 #ifdef KERNFS_DIAGNOSTIC
    207 	printf("kernfs_root(mp = %x)\n", mp);
    208 #endif
    209 
    210 	/*
    211 	 * Return locked reference to root.
    212 	 */
    213 	vp = VFSTOKERNFS(mp)->kf_root;
    214 	VREF(vp);
    215 	VOP_LOCK(vp);
    216 	*vpp = vp;
    217 	return (0);
    218 }
    219 
    220 kernfs_quotactl(mp, cmd, uid, arg, p)
    221 	struct mount *mp;
    222 	int cmd;
    223 	uid_t uid;
    224 	caddr_t arg;
    225 	struct proc *p;
    226 {
    227 
    228 	return (EOPNOTSUPP);
    229 }
    230 
    231 kernfs_statfs(mp, sbp, p)
    232 	struct mount *mp;
    233 	struct statfs *sbp;
    234 	struct proc *p;
    235 {
    236 
    237 #ifdef KERNFS_DIAGNOSTIC
    238 	printf("kernfs_statfs(mp = %x)\n", mp);
    239 #endif
    240 
    241 #ifdef COMPAT_09
    242 	sbp->f_type = 7;
    243 #else
    244 	sbp->f_type = 0;
    245 #endif
    246 	sbp->f_bsize = DEV_BSIZE;
    247 	sbp->f_iosize = DEV_BSIZE;
    248 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    249 	sbp->f_bfree = 0;
    250 	sbp->f_bavail = 0;
    251 	sbp->f_files = 0;
    252 	sbp->f_ffree = 0;
    253 	if (sbp != &mp->mnt_stat) {
    254 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
    255 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
    256 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
    257 	}
    258 	strncpy(&sbp->f_fstypename[0], mp->mnt_op->vfs_name, MFSNAMELEN);
    259 	sbp->f_fstypename[MFSNAMELEN] = '\0';
    260 	return (0);
    261 }
    262 
    263 kernfs_sync(mp, waitfor)
    264 	struct mount *mp;
    265 	int waitfor;
    266 {
    267 
    268 	return (0);
    269 }
    270 
    271 /*
    272  * Kernfs flat namespace lookup.
    273  * Currently unsupported.
    274  */
    275 kernfs_vget(mp, ino, vpp)
    276 	struct mount *mp;
    277 	ino_t ino;
    278 	struct vnode **vpp;
    279 {
    280 
    281 	return (EOPNOTSUPP);
    282 }
    283 
    284 
    285 kernfs_fhtovp(mp, fhp, setgen, vpp)
    286 	struct mount *mp;
    287 	struct fid *fhp;
    288 	int setgen;
    289 	struct vnode **vpp;
    290 {
    291 
    292 	return (EOPNOTSUPP);
    293 }
    294 
    295 kernfs_vptofh(vp, fhp)
    296 	struct vnode *vp;
    297 	struct fid *fhp;
    298 {
    299 
    300 	return (EOPNOTSUPP);
    301 }
    302 
    303 struct vfsops kernfs_vfsops = {
    304 	MOUNT_KERNFS,
    305 	kernfs_mount,
    306 	kernfs_start,
    307 	kernfs_unmount,
    308 	kernfs_root,
    309 	kernfs_quotactl,
    310 	kernfs_statfs,
    311 	kernfs_sync,
    312 	kernfs_vget,
    313 	kernfs_fhtovp,
    314 	kernfs_vptofh,
    315 	kernfs_init,
    316 };
    317