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kernfs_vfsops.c revision 1.39
      1 /*	$NetBSD: kernfs_vfsops.c,v 1.39 2001/02/04 10:20:00 mrg 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_done __P((void));
     66 void	kernfs_get_rrootdev __P((void));
     67 int	kernfs_mount __P((struct mount *, const char *, void *,
     68 	    struct nameidata *, struct proc *));
     69 int	kernfs_start __P((struct mount *, int, struct proc *));
     70 int	kernfs_unmount __P((struct mount *, int, struct proc *));
     71 int	kernfs_root __P((struct mount *, struct vnode **));
     72 int	kernfs_statfs __P((struct mount *, struct statfs *, struct proc *));
     73 int	kernfs_quotactl __P((struct mount *, int, uid_t, caddr_t,
     74 			     struct proc *));
     75 int	kernfs_sync __P((struct mount *, int, struct ucred *, struct proc *));
     76 int	kernfs_vget __P((struct mount *, ino_t, struct vnode **));
     77 int	kernfs_fhtovp __P((struct mount *, struct fid *, struct vnode **));
     78 int	kernfs_checkexp __P((struct mount *, struct mbuf *, int *,
     79 			   struct ucred **));
     80 int	kernfs_vptofh __P((struct vnode *, struct fid *));
     81 int	kernfs_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
     82 			   struct proc *));
     83 
     84 void
     85 kernfs_init()
     86 {
     87 }
     88 
     89 void
     90 kernfs_done()
     91 {
     92 }
     93 
     94 void
     95 kernfs_get_rrootdev()
     96 {
     97 	static int tried = 0;
     98 	int cmaj;
     99 
    100 	if (tried) {
    101 		/* Already did it once. */
    102 		return;
    103 	}
    104 	tried = 1;
    105 
    106 	if (rootdev == NODEV)
    107 		return;
    108 	for (cmaj = 0; cmaj < nchrdev; cmaj++) {
    109 		rrootdev = makedev(cmaj, minor(rootdev));
    110 		if (chrtoblk(rrootdev) == rootdev) {
    111 #ifdef KERNFS_DIAGNOSTIC
    112 	printf("kernfs_mount: rootdev = %u.%u; rrootdev = %u.%u\n",
    113 	    major(rootdev), minor(rootdev), major(rrootdev), minor(rrootdev));
    114 #endif
    115 			return;
    116 		}
    117 	}
    118 	rrootdev = NODEV;
    119 	printf("kernfs_get_rrootdev: no raw root device\n");
    120 }
    121 
    122 /*
    123  * Mount the Kernel params filesystem
    124  */
    125 int
    126 kernfs_mount(mp, path, data, ndp, p)
    127 	struct mount *mp;
    128 	const char *path;
    129 	void *data;
    130 	struct nameidata *ndp;
    131 	struct proc *p;
    132 {
    133 	int error = 0;
    134 	size_t size;
    135 	struct kernfs_mount *fmp;
    136 	struct vnode *rvp;
    137 
    138 #ifdef KERNFS_DIAGNOSTIC
    139 	printf("kernfs_mount(mp = %p)\n", mp);
    140 #endif
    141 
    142 	/*
    143 	 * Update is a no-op
    144 	 */
    145 	if (mp->mnt_flag & MNT_UPDATE)
    146 		return (EOPNOTSUPP);
    147 
    148 	error = getnewvnode(VT_KERNFS, mp, kernfs_vnodeop_p, &rvp);
    149 	if (error)
    150 		return (error);
    151 
    152 	MALLOC(fmp, struct kernfs_mount *, sizeof(struct kernfs_mount),
    153 	    M_MISCFSMNT, M_WAITOK);
    154 	rvp->v_type = VDIR;
    155 	rvp->v_flag |= VROOT;
    156 #ifdef KERNFS_DIAGNOSTIC
    157 	printf("kernfs_mount: root vp = %p\n", rvp);
    158 #endif
    159 	fmp->kf_root = rvp;
    160 	mp->mnt_flag |= MNT_LOCAL;
    161 	mp->mnt_data = (qaddr_t)fmp;
    162 	vfs_getnewfsid(mp);
    163 
    164 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    165 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    166 	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
    167 	memcpy(mp->mnt_stat.f_mntfromname, "kernfs", sizeof("kernfs"));
    168 #ifdef KERNFS_DIAGNOSTIC
    169 	printf("kernfs_mount: at %s\n", mp->mnt_stat.f_mntonname);
    170 #endif
    171 
    172 	kernfs_get_rrootdev();
    173 	return (0);
    174 }
    175 
    176 int
    177 kernfs_start(mp, flags, p)
    178 	struct mount *mp;
    179 	int flags;
    180 	struct proc *p;
    181 {
    182 
    183 	return (0);
    184 }
    185 
    186 int
    187 kernfs_unmount(mp, mntflags, p)
    188 	struct mount *mp;
    189 	int mntflags;
    190 	struct proc *p;
    191 {
    192 	int error;
    193 	int flags = 0;
    194 	struct vnode *rootvp = VFSTOKERNFS(mp)->kf_root;
    195 
    196 #ifdef KERNFS_DIAGNOSTIC
    197 	printf("kernfs_unmount(mp = %p)\n", mp);
    198 #endif
    199 
    200 	 if (mntflags & MNT_FORCE)
    201 		flags |= FORCECLOSE;
    202 
    203 	/*
    204 	 * Clear out buffer cache.  I don't think we
    205 	 * ever get anything cached at this level at the
    206 	 * moment, but who knows...
    207 	 */
    208 	if (rootvp->v_usecount > 1)
    209 		return (EBUSY);
    210 #ifdef KERNFS_DIAGNOSTIC
    211 	printf("kernfs_unmount: calling vflush\n");
    212 #endif
    213 	if ((error = vflush(mp, rootvp, flags)) != 0)
    214 		return (error);
    215 
    216 #ifdef KERNFS_DIAGNOSTIC
    217 	vprint("kernfs root", rootvp);
    218 #endif
    219 	/*
    220 	 * Clean out the old root vnode for reuse.
    221 	 */
    222 	vrele(rootvp);
    223 	vgone(rootvp);
    224 	/*
    225 	 * Finally, throw away the kernfs_mount structure
    226 	 */
    227 	free(mp->mnt_data, M_MISCFSMNT);
    228 	mp->mnt_data = 0;
    229 	return (0);
    230 }
    231 
    232 int
    233 kernfs_root(mp, vpp)
    234 	struct mount *mp;
    235 	struct vnode **vpp;
    236 {
    237 	struct vnode *vp;
    238 
    239 #ifdef KERNFS_DIAGNOSTIC
    240 	printf("kernfs_root(mp = %p)\n", mp);
    241 #endif
    242 
    243 	/*
    244 	 * Return locked reference to root.
    245 	 */
    246 	vp = VFSTOKERNFS(mp)->kf_root;
    247 	VREF(vp);
    248 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    249 	*vpp = vp;
    250 	return (0);
    251 }
    252 
    253 int
    254 kernfs_quotactl(mp, cmd, uid, arg, p)
    255 	struct mount *mp;
    256 	int cmd;
    257 	uid_t uid;
    258 	caddr_t arg;
    259 	struct proc *p;
    260 {
    261 
    262 	return (EOPNOTSUPP);
    263 }
    264 
    265 int
    266 kernfs_statfs(mp, sbp, p)
    267 	struct mount *mp;
    268 	struct statfs *sbp;
    269 	struct proc *p;
    270 {
    271 
    272 #ifdef KERNFS_DIAGNOSTIC
    273 	printf("kernfs_statfs(mp = %p)\n", mp);
    274 #endif
    275 
    276 	sbp->f_bsize = DEV_BSIZE;
    277 	sbp->f_iosize = DEV_BSIZE;
    278 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    279 	sbp->f_bfree = 0;
    280 	sbp->f_bavail = 0;
    281 	sbp->f_files = 0;
    282 	sbp->f_ffree = 0;
    283 #ifdef COMPAT_09
    284 	sbp->f_type = 7;
    285 #else
    286 	sbp->f_type = 0;
    287 #endif
    288 	if (sbp != &mp->mnt_stat) {
    289 		memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
    290 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
    291 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
    292 	}
    293 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
    294 	return (0);
    295 }
    296 
    297 /*ARGSUSED*/
    298 int
    299 kernfs_sync(mp, waitfor, uc, p)
    300 	struct mount *mp;
    301 	int waitfor;
    302 	struct ucred *uc;
    303 	struct proc *p;
    304 {
    305 
    306 	return (0);
    307 }
    308 
    309 /*
    310  * Kernfs flat namespace lookup.
    311  * Currently unsupported.
    312  */
    313 int
    314 kernfs_vget(mp, ino, vpp)
    315 	struct mount *mp;
    316 	ino_t ino;
    317 	struct vnode **vpp;
    318 {
    319 
    320 	return (EOPNOTSUPP);
    321 }
    322 
    323 /*ARGSUSED*/
    324 int
    325 kernfs_fhtovp(mp, fhp, vpp)
    326 	struct mount *mp;
    327 	struct fid *fhp;
    328 	struct vnode **vpp;
    329 {
    330 
    331 	return (EOPNOTSUPP);
    332 }
    333 
    334 /*ARGSUSED*/
    335 int
    336 kernfs_checkexp(mp, mb, what, anon)
    337 	struct mount *mp;
    338 	struct mbuf *mb;
    339 	int *what;
    340 	struct ucred **anon;
    341 {
    342 
    343 	return (EOPNOTSUPP);
    344 }
    345 
    346 /*ARGSUSED*/
    347 int
    348 kernfs_vptofh(vp, fhp)
    349 	struct vnode *vp;
    350 	struct fid *fhp;
    351 {
    352 
    353 	return (EOPNOTSUPP);
    354 }
    355 
    356 int
    357 kernfs_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
    358 	int *name;
    359 	u_int namelen;
    360 	void *oldp;
    361 	size_t *oldlenp;
    362 	void *newp;
    363 	size_t newlen;
    364 	struct proc *p;
    365 {
    366 	return (EOPNOTSUPP);
    367 }
    368 
    369 extern const struct vnodeopv_desc kernfs_vnodeop_opv_desc;
    370 
    371 const struct vnodeopv_desc * const kernfs_vnodeopv_descs[] = {
    372 	&kernfs_vnodeop_opv_desc,
    373 	NULL,
    374 };
    375 
    376 struct vfsops kernfs_vfsops = {
    377 	MOUNT_KERNFS,
    378 	kernfs_mount,
    379 	kernfs_start,
    380 	kernfs_unmount,
    381 	kernfs_root,
    382 	kernfs_quotactl,
    383 	kernfs_statfs,
    384 	kernfs_sync,
    385 	kernfs_vget,
    386 	kernfs_fhtovp,
    387 	kernfs_vptofh,
    388 	kernfs_init,
    389 	kernfs_done,
    390 	kernfs_sysctl,
    391 	NULL,				/* vfs_mountroot */
    392 	kernfs_checkexp,
    393 	kernfs_vnodeopv_descs,
    394 };
    395