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fdesc_vfsops.c revision 1.22
      1 /*	$NetBSD: fdesc_vfsops.c,v 1.22 1996/12/22 10:10:19 cgd 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  *	@(#)fdesc_vfsops.c	8.4 (Berkeley) 1/21/94
     39  *
     40  * #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp #
     41  */
     42 
     43 /*
     44  * /dev/fd Filesystem
     45  */
     46 
     47 #include <sys/param.h>
     48 #include <sys/systm.h>
     49 #include <sys/time.h>
     50 #include <sys/types.h>
     51 #include <sys/proc.h>
     52 #include <sys/resourcevar.h>
     53 #include <sys/filedesc.h>
     54 #include <sys/vnode.h>
     55 #include <sys/mount.h>
     56 #include <sys/namei.h>
     57 #include <sys/malloc.h>
     58 #include <miscfs/fdesc/fdesc.h>
     59 
     60 int	fdesc_mount __P((struct mount *, const char *, void *,
     61 			 struct nameidata *, struct proc *));
     62 int	fdesc_start __P((struct mount *, int, struct proc *));
     63 int	fdesc_unmount __P((struct mount *, int, struct proc *));
     64 int	fdesc_root __P((struct mount *, struct vnode **));
     65 int	fdesc_quotactl __P((struct mount *, int, uid_t, caddr_t,
     66 			    struct proc *));
     67 int	fdesc_statfs __P((struct mount *, struct statfs *, struct proc *));
     68 int	fdesc_sync __P((struct mount *, int, struct ucred *, struct proc *));
     69 int	fdesc_vget __P((struct mount *, ino_t, struct vnode **));
     70 int	fdesc_fhtovp __P((struct mount *, struct fid *, struct mbuf *,
     71 			  struct vnode **, int *, struct ucred **));
     72 int	fdesc_vptofh __P((struct vnode *, struct fid *));
     73 
     74 /*
     75  * Mount the per-process file descriptors (/dev/fd)
     76  */
     77 int
     78 fdesc_mount(mp, path, data, ndp, p)
     79 	struct mount *mp;
     80 	const char *path;
     81 	void *data;
     82 	struct nameidata *ndp;
     83 	struct proc *p;
     84 {
     85 	int error = 0;
     86 	size_t size;
     87 	struct fdescmount *fmp;
     88 	struct vnode *rvp;
     89 
     90 	/*
     91 	 * Update is a no-op
     92 	 */
     93 	if (mp->mnt_flag & MNT_UPDATE)
     94 		return (EOPNOTSUPP);
     95 
     96 	error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
     97 	if (error)
     98 		return (error);
     99 
    100 	MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
    101 				M_UFSMNT, M_WAITOK);	/* XXX */
    102 	rvp->v_type = VDIR;
    103 	rvp->v_flag |= VROOT;
    104 	fmp->f_root = rvp;
    105 	mp->mnt_flag |= MNT_LOCAL;
    106 	mp->mnt_data = (qaddr_t)fmp;
    107 	getnewfsid(mp, makefstype(MOUNT_FDESC));
    108 
    109 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    110 	bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
    111 	bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
    112 	bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
    113 	return (0);
    114 }
    115 
    116 int
    117 fdesc_start(mp, flags, p)
    118 	struct mount *mp;
    119 	int flags;
    120 	struct proc *p;
    121 {
    122 	return (0);
    123 }
    124 
    125 int
    126 fdesc_unmount(mp, mntflags, p)
    127 	struct mount *mp;
    128 	int mntflags;
    129 	struct proc *p;
    130 {
    131 	int error;
    132 	int flags = 0;
    133 	extern int doforce;
    134 	struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
    135 
    136 	if (mntflags & MNT_FORCE) {
    137 		/* fdesc can never be rootfs so don't check for it */
    138 		if (!doforce)
    139 			return (EINVAL);
    140 		flags |= FORCECLOSE;
    141 	}
    142 
    143 	/*
    144 	 * Clear out buffer cache.  I don't think we
    145 	 * ever get anything cached at this level at the
    146 	 * moment, but who knows...
    147 	 */
    148 	if (rootvp->v_usecount > 1)
    149 		return (EBUSY);
    150 	if ((error = vflush(mp, rootvp, flags)) != 0)
    151 		return (error);
    152 
    153 	/*
    154 	 * Release reference on underlying root vnode
    155 	 */
    156 	vrele(rootvp);
    157 	/*
    158 	 * And blow it away for future re-use
    159 	 */
    160 	vgone(rootvp);
    161 	/*
    162 	 * Finally, throw away the fdescmount structure
    163 	 */
    164 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    165 	mp->mnt_data = 0;
    166 
    167 	return (0);
    168 }
    169 
    170 int
    171 fdesc_root(mp, vpp)
    172 	struct mount *mp;
    173 	struct vnode **vpp;
    174 {
    175 	struct vnode *vp;
    176 
    177 	/*
    178 	 * Return locked reference to root.
    179 	 */
    180 	vp = VFSTOFDESC(mp)->f_root;
    181 	VREF(vp);
    182 	VOP_LOCK(vp);
    183 	*vpp = vp;
    184 	return (0);
    185 }
    186 
    187 int
    188 fdesc_quotactl(mp, cmd, uid, arg, p)
    189 	struct mount *mp;
    190 	int cmd;
    191 	uid_t uid;
    192 	caddr_t arg;
    193 	struct proc *p;
    194 {
    195 
    196 	return (EOPNOTSUPP);
    197 }
    198 
    199 int
    200 fdesc_statfs(mp, sbp, p)
    201 	struct mount *mp;
    202 	struct statfs *sbp;
    203 	struct proc *p;
    204 {
    205 	struct filedesc *fdp;
    206 	int lim;
    207 	int i;
    208 	int last;
    209 	int freefd;
    210 
    211 	/*
    212 	 * Compute number of free file descriptors.
    213 	 * [ Strange results will ensue if the open file
    214 	 * limit is ever reduced below the current number
    215 	 * of open files... ]
    216 	 */
    217 	lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
    218 	fdp = p->p_fd;
    219 	last = min(fdp->fd_nfiles, lim);
    220 	freefd = 0;
    221 	for (i = fdp->fd_freefile; i < last; i++)
    222 		if (fdp->fd_ofiles[i] == NULL)
    223 			freefd++;
    224 
    225 	/*
    226 	 * Adjust for the fact that the fdesc array may not
    227 	 * have been fully allocated yet.
    228 	 */
    229 	if (fdp->fd_nfiles < lim)
    230 		freefd += (lim - fdp->fd_nfiles);
    231 
    232 #ifdef COMPAT_09
    233 	sbp->f_type = 6;
    234 #else
    235 	sbp->f_type = 0;
    236 #endif
    237 	sbp->f_bsize = DEV_BSIZE;
    238 	sbp->f_iosize = DEV_BSIZE;
    239 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    240 	sbp->f_bfree = 0;
    241 	sbp->f_bavail = 0;
    242 	sbp->f_files = lim + 1;		/* Allow for "." */
    243 	sbp->f_ffree = freefd;		/* See comments above */
    244 	if (sbp != &mp->mnt_stat) {
    245 		bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
    246 		bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
    247 		bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
    248 	}
    249 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
    250 	return (0);
    251 }
    252 
    253 /*ARGSUSED*/
    254 int
    255 fdesc_sync(mp, waitfor, uc, p)
    256 	struct mount *mp;
    257 	int waitfor;
    258 	struct ucred *uc;
    259 	struct proc *p;
    260 {
    261 
    262 	return (0);
    263 }
    264 
    265 /*
    266  * Fdesc flat namespace lookup.
    267  * Currently unsupported.
    268  */
    269 int
    270 fdesc_vget(mp, ino, vpp)
    271 	struct mount *mp;
    272 	ino_t ino;
    273 	struct vnode **vpp;
    274 {
    275 
    276 	return (EOPNOTSUPP);
    277 }
    278 
    279 
    280 /*ARGSUSED*/
    281 int
    282 fdesc_fhtovp(mp, fhp, nam, vpp, exflagsp, credanonp)
    283 	struct mount *mp;
    284 	struct fid *fhp;
    285 	struct mbuf *nam;
    286 	struct vnode **vpp;
    287 	int *exflagsp;
    288 	struct ucred **credanonp;
    289 {
    290 
    291 	return (EOPNOTSUPP);
    292 }
    293 
    294 /*ARGSUSED*/
    295 int
    296 fdesc_vptofh(vp, fhp)
    297 	struct vnode *vp;
    298 	struct fid *fhp;
    299 {
    300 	return (EOPNOTSUPP);
    301 }
    302 
    303 struct vfsops fdesc_vfsops = {
    304 	MOUNT_FDESC,
    305 	fdesc_mount,
    306 	fdesc_start,
    307 	fdesc_unmount,
    308 	fdesc_root,
    309 	fdesc_quotactl,
    310 	fdesc_statfs,
    311 	fdesc_sync,
    312 	fdesc_vget,
    313 	fdesc_fhtovp,
    314 	fdesc_vptofh,
    315 	fdesc_init,
    316 };
    317