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kernfs_vfsops.c revision 1.34
      1 /*	$NetBSD: kernfs_vfsops.c,v 1.34 1998/08/09 20:51:08 perry Exp $	*/
      2 
      3 /*
      4  * Copyright (c) 1992, 1993, 1995
      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	8.10 (Berkeley) 5/14/95
     39  */
     40 
     41 /*
     42  * Kernel params Filesystem
     43  */
     44 
     45 #if defined(_KERNEL) && !defined(_LKM)
     46 #include "opt_compat_netbsd.h"
     47 #endif
     48 
     49 #include <sys/param.h>
     50 #include <sys/systm.h>
     51 #include <sys/conf.h>
     52 #include <sys/types.h>
     53 #include <sys/proc.h>
     54 #include <sys/vnode.h>
     55 #include <sys/mount.h>
     56 #include <sys/namei.h>
     57 #include <sys/malloc.h>
     58 
     59 #include <miscfs/specfs/specdev.h>
     60 #include <miscfs/kernfs/kernfs.h>
     61 
     62 dev_t rrootdev = NODEV;
     63 
     64 void	kernfs_init __P((void));
     65 void	kernfs_get_rrootdev __P((void));
     66 int	kernfs_mount __P((struct mount *, const char *, void *,
     67 	    struct nameidata *, struct proc *));
     68 int	kernfs_start __P((struct mount *, int, struct proc *));
     69 int	kernfs_unmount __P((struct mount *, int, struct proc *));
     70 int	kernfs_root __P((struct mount *, struct vnode **));
     71 int	kernfs_statfs __P((struct mount *, struct statfs *, struct proc *));
     72 int	kernfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
     73 			     struct proc *));
     74 int	kernfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
     75 int	kernfs_vget __P((struct mount *, ino_t, struct vnode **));
     76 int	kernfs_fhtovp __P((struct mount *, struct fid *, struct mbuf *,
     77 			   struct vnode **, int *, struct ucred **));
     78 int	kernfs_vptofh __P((struct vnode *, struct fid *));
     79 int	kernfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
     80 			   struct proc *));
     81 
     82 void
     83 kernfs_init()
     84 {
     85 }
     86 
     87 void
     88 kernfs_get_rrootdev()
     89 {
     90 	static int tried = 0;
     91 	int cmaj;
     92 
     93 	if (tried) {
     94 		/* Already did it once. */
     95 		return;
     96 	}
     97 	tried = 1;
     98 
     99 	if (rootdev == NODEV)
    100 		return;
    101 	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
    102 		rrootdev = makedev(cmaj, minor(rootdev));
    103 		if (chrtoblk(rrootdev) == rootdev)
    104 			return;
    105 	}
    106 	rrootdev = NODEV;
    107 	printf("kernfs_get_rrootdev: no raw root device\n");
    108 }
    109 
    110 /*
    111  * Mount the Kernel params filesystem
    112  */
    113 int
    114 kernfs_mount(mp, path, data, ndp, p)
    115 	struct mount *mp;
    116 	const char *path;
    117 	void *data;
    118 	struct nameidata *ndp;
    119 	struct proc *p;
    120 {
    121 	int error = 0;
    122 	size_t size;
    123 	struct kernfs_mount *fmp;
    124 	struct vnode *rvp;
    125 
    126 #ifdef KERNFS_DIAGNOSTIC
    127 	printf("kernfs_mount(mp = %p)\n", mp);
    128 #endif
    129 
    130 	/*
    131 	 * Update is a no-op
    132 	 */
    133 	if (mp->mnt_flag & MNT_UPDATE)
    134 		return (EOPNOTSUPP);
    135 
    136 	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);
    137 	if (error)
    138 		return (error);
    139 
    140 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
    141 	    M_MISCFSMNT, M_WAITOK);
    142 	rvp->v_type = VDIR;
    143 	rvp->v_flag |= VROOT;
    144 #ifdef KERNFS_DIAGNOSTIC
    145 	printf("kernfs_mount: root vp = %p\n", rvp);
    146 #endif
    147 	fmp->kf_root = rvp;
    148 	mp->mnt_flag |= MNT_LOCAL;
    149 	mp->mnt_data = (qaddr_t)fmp;
    150 	vfs_getnewfsid(mp, MOUNT_KERNFS);
    151 
    152 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    153 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    154 	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
    155 	memcpy(mp->mnt_stat.f_mntfromname, "kernfs", sizeof("kernfs"));
    156 #ifdef KERNFS_DIAGNOSTIC
    157 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
    158 #endif
    159 
    160 	kernfs_get_rrootdev();
    161 	return (0);
    162 }
    163 
    164 int
    165 kernfs_start(mp, flags, p)
    166 	struct mount *mp;
    167 	int flags;
    168 	struct proc *p;
    169 {
    170 
    171 	return (0);
    172 }
    173 
    174 int
    175 kernfs_unmount(mp, mntflags, p)
    176 	struct mount *mp;
    177 	int mntflags;
    178 	struct proc *p;
    179 {
    180 	int error;
    181 	int flags = 0;
    182 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
    183 
    184 #ifdef KERNFS_DIAGNOSTIC
    185 	printf("kernfs_unmount(mp = %p)\n", mp);
    186 #endif
    187 
    188 	 if (mntflags & MNT_FORCE)
    189 		flags |= FORCECLOSE;
    190 
    191 	/*
    192 	 * Clear out buffer cache.  I don't think we
    193 	 * ever get anything cached at this level at the
    194 	 * moment, but who knows...
    195 	 */
    196 	if (rootvp->v_usecount > 1)
    197 		return (EBUSY);
    198 #ifdef KERNFS_DIAGNOSTIC
    199 	printf("kernfs_unmount: calling vflush\n");
    200 #endif
    201 	if ((error = vflush(mp, rootvp, flags)) != 0)
    202 		return (error);
    203 
    204 #ifdef KERNFS_DIAGNOSTIC
    205 	vprint("kernfs root", rootvp);
    206 #endif
    207 	/*
    208 	 * Clean out the old root vnode for reuse.
    209 	 */
    210 	vrele(rootvp);
    211 	vgone(rootvp);
    212 	/*
    213 	 * Finally, throw away the kernfs_mount structure
    214 	 */
    215 	free(mp->mnt_data, M_MISCFSMNT);
    216 	mp->mnt_data = 0;
    217 	return (0);
    218 }
    219 
    220 int
    221 kernfs_root(mp, vpp)
    222 	struct mount *mp;
    223 	struct vnode **vpp;
    224 {
    225 	struct vnode *vp;
    226 
    227 #ifdef KERNFS_DIAGNOSTIC
    228 	printf("kernfs_root(mp = %p)\n", mp);
    229 #endif
    230 
    231 	/*
    232 	 * Return locked reference to root.
    233 	 */
    234 	vp = VFSTOKERNFS(mp)->kf_root;
    235 	VREF(vp);
    236 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    237 	*vpp = vp;
    238 	return (0);
    239 }
    240 
    241 int
    242 kernfs_quotactl(mp, cmd, uid, arg, p)
    243 	struct mount *mp;
    244 	int cmd;
    245 	uid_t uid;
    246 	caddr_t arg;
    247 	struct proc *p;
    248 {
    249 
    250 	return (EOPNOTSUPP);
    251 }
    252 
    253 int
    254 kernfs_statfs(mp, sbp, p)
    255 	struct mount *mp;
    256 	struct statfs *sbp;
    257 	struct proc *p;
    258 {
    259 
    260 #ifdef KERNFS_DIAGNOSTIC
    261 	printf("kernfs_statfs(mp = %p)\n", mp);
    262 #endif
    263 
    264 	sbp->f_bsize = DEV_BSIZE;
    265 	sbp->f_iosize = DEV_BSIZE;
    266 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    267 	sbp->f_bfree = 0;
    268 	sbp->f_bavail = 0;
    269 	sbp->f_files = 0;
    270 	sbp->f_ffree = 0;
    271 #ifdef COMPAT_09
    272 	sbp->f_type = 7;
    273 #else
    274 	sbp->f_type = 0;
    275 #endif
    276 	if (sbp != &mp->mnt_stat) {
    277 		memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
    278 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
    279 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
    280 	}
    281 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
    282 	return (0);
    283 }
    284 
    285 /*ARGSUSED*/
    286 int
    287 kernfs_sync(mp, waitfor, uc, p)
    288 	struct mount *mp;
    289 	int waitfor;
    290 	struct ucred *uc;
    291 	struct proc *p;
    292 {
    293 
    294 	return (0);
    295 }
    296 
    297 /*
    298  * Kernfs flat namespace lookup.
    299  * Currently unsupported.
    300  */
    301 int
    302 kernfs_vget(mp, ino, vpp)
    303 	struct mount *mp;
    304 	ino_t ino;
    305 	struct vnode **vpp;
    306 {
    307 
    308 	return (EOPNOTSUPP);
    309 }
    310 
    311 /*ARGSUSED*/
    312 int
    313 kernfs_fhtovp(mp, fhp, mb, vpp, what, anon)
    314 	struct mount *mp;
    315 	struct fid *fhp;
    316 	struct mbuf *mb;
    317 	struct vnode **vpp;
    318 	int *what;
    319 	struct ucred **anon;
    320 {
    321 
    322 	return (EOPNOTSUPP);
    323 }
    324 
    325 /*ARGSUSED*/
    326 int
    327 kernfs_vptofh(vp, fhp)
    328 	struct vnode *vp;
    329 	struct fid *fhp;
    330 {
    331 
    332 	return (EOPNOTSUPP);
    333 }
    334 
    335 int
    336 kernfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
    337 	int *name;
    338 	u_int namelen;
    339 	void *oldp;
    340 	size_t *oldlenp;
    341 	void *newp;
    342 	size_t newlen;
    343 	struct proc *p;
    344 {
    345 	return (EOPNOTSUPP);
    346 }
    347 
    348 extern struct vnodeopv_desc kernfs_vnodeop_opv_desc;
    349 
    350 struct vnodeopv_desc *kernfs_vnodeopv_descs[] = {
    351 	&kernfs_vnodeop_opv_desc,
    352 	NULL,
    353 };
    354 
    355 struct vfsops kernfs_vfsops = {
    356 	MOUNT_KERNFS,
    357 	kernfs_mount,
    358 	kernfs_start,
    359 	kernfs_unmount,
    360 	kernfs_root,
    361 	kernfs_quotactl,
    362 	kernfs_statfs,
    363 	kernfs_sync,
    364 	kernfs_vget,
    365 	kernfs_fhtovp,
    366 	kernfs_vptofh,
    367 	kernfs_init,
    368 	kernfs_sysctl,
    369 	NULL,				/* vfs_mountroot */
    370 	kernfs_vnodeopv_descs,
    371 };
    372