Home | History | Annotate | Line # | Download | only in fdesc
fdesc_vfsops.c revision 1.38
      1 /*	$NetBSD: fdesc_vfsops.c,v 1.38 2002/09/21 18:09:27 christos 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  *	@(#)fdesc_vfsops.c	8.10 (Berkeley) 5/14/95
     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/cdefs.h>
     48 __KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.38 2002/09/21 18:09:27 christos Exp $");
     49 
     50 #if defined(_KERNEL_OPT)
     51 #include "opt_compat_netbsd.h"
     52 #endif
     53 
     54 #include <sys/param.h>
     55 #include <sys/systm.h>
     56 #include <sys/time.h>
     57 #include <sys/proc.h>
     58 #include <sys/resourcevar.h>
     59 #include <sys/filedesc.h>
     60 #include <sys/vnode.h>
     61 #include <sys/mount.h>
     62 #include <sys/namei.h>
     63 #include <sys/malloc.h>
     64 #include <miscfs/fdesc/fdesc.h>
     65 
     66 int	fdesc_mount __P((struct mount *, const char *, void *,
     67 			 struct nameidata *, struct proc *));
     68 int	fdesc_start __P((struct mount *, int, struct proc *));
     69 int	fdesc_unmount __P((struct mount *, int, struct proc *));
     70 int	fdesc_quotactl __P((struct mount *, int, uid_t, caddr_t,
     71 			    struct proc *));
     72 int	fdesc_statfs __P((struct mount *, struct statfs *, struct proc *));
     73 int	fdesc_sync __P((struct mount *, int, struct ucred *, struct proc *));
     74 int	fdesc_vget __P((struct mount *, ino_t, struct vnode **));
     75 int	fdesc_fhtovp __P((struct mount *, struct fid *, struct vnode **));
     76 int	fdesc_checkexp __P((struct mount *, struct mbuf *, int *,
     77 			    struct ucred **));
     78 int	fdesc_vptofh __P((struct vnode *, struct fid *));
     79 int	fdesc_sysctl __P((int *, u_int, void *, size_t *, void *, size_t,
     80 			  struct proc *));
     81 
     82 /*
     83  * Mount the per-process file descriptors (/dev/fd)
     84  */
     85 int
     86 fdesc_mount(mp, path, data, ndp, p)
     87 	struct mount *mp;
     88 	const char *path;
     89 	void *data;
     90 	struct nameidata *ndp;
     91 	struct proc *p;
     92 {
     93 	int error = 0;
     94 	size_t size;
     95 	struct fdescmount *fmp;
     96 	struct vnode *rvp;
     97 
     98 	if (mp->mnt_flag & MNT_GETARGS)
     99 		return 0;
    100 	/*
    101 	 * Update is a no-op
    102 	 */
    103 	if (mp->mnt_flag & MNT_UPDATE)
    104 		return (EOPNOTSUPP);
    105 
    106 	error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
    107 	if (error)
    108 		return (error);
    109 
    110 	MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
    111 				M_UFSMNT, M_WAITOK);	/* XXX */
    112 	rvp->v_type = VDIR;
    113 	rvp->v_flag |= VROOT;
    114 	fmp->f_root = rvp;
    115 	mp->mnt_flag |= MNT_LOCAL;
    116 	mp->mnt_data = fmp;
    117 	vfs_getnewfsid(mp);
    118 
    119 	(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
    120 	memset(mp->mnt_stat.f_mntonname + size, 0, MNAMELEN - size);
    121 	memset(mp->mnt_stat.f_mntfromname, 0, MNAMELEN);
    122 	memcpy(mp->mnt_stat.f_mntfromname, "fdesc", sizeof("fdesc"));
    123 	VOP_UNLOCK(rvp, 0);
    124 	return (0);
    125 }
    126 
    127 int
    128 fdesc_start(mp, flags, p)
    129 	struct mount *mp;
    130 	int flags;
    131 	struct proc *p;
    132 {
    133 	return (0);
    134 }
    135 
    136 int
    137 fdesc_unmount(mp, mntflags, p)
    138 	struct mount *mp;
    139 	int mntflags;
    140 	struct proc *p;
    141 {
    142 	int error;
    143 	int flags = 0;
    144 	struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
    145 
    146 	if (mntflags & MNT_FORCE)
    147 		flags |= FORCECLOSE;
    148 
    149 	/*
    150 	 * Clear out buffer cache.  I don't think we
    151 	 * ever get anything cached at this level at the
    152 	 * moment, but who knows...
    153 	 */
    154 	if (rootvp->v_usecount > 1)
    155 		return (EBUSY);
    156 	if ((error = vflush(mp, rootvp, flags)) != 0)
    157 		return (error);
    158 
    159 	/*
    160 	 * Release reference on underlying root vnode
    161 	 */
    162 	vrele(rootvp);
    163 	/*
    164 	 * And blow it away for future re-use
    165 	 */
    166 	vgone(rootvp);
    167 	/*
    168 	 * Finally, throw away the fdescmount structure
    169 	 */
    170 	free(mp->mnt_data, M_UFSMNT);	/* XXX */
    171 	mp->mnt_data = 0;
    172 
    173 	return (0);
    174 }
    175 
    176 int
    177 fdesc_root(mp, vpp)
    178 	struct mount *mp;
    179 	struct vnode **vpp;
    180 {
    181 	struct vnode *vp;
    182 
    183 	/*
    184 	 * Return locked reference to root.
    185 	 */
    186 	vp = VFSTOFDESC(mp)->f_root;
    187 	VREF(vp);
    188 	vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
    189 	*vpp = vp;
    190 	return (0);
    191 }
    192 
    193 int
    194 fdesc_quotactl(mp, cmd, uid, arg, p)
    195 	struct mount *mp;
    196 	int cmd;
    197 	uid_t uid;
    198 	caddr_t arg;
    199 	struct proc *p;
    200 {
    201 
    202 	return (EOPNOTSUPP);
    203 }
    204 
    205 int
    206 fdesc_statfs(mp, sbp, p)
    207 	struct mount *mp;
    208 	struct statfs *sbp;
    209 	struct proc *p;
    210 {
    211 	struct filedesc *fdp;
    212 	int lim;
    213 	int i;
    214 	int last;
    215 	int freefd;
    216 
    217 	/*
    218 	 * Compute number of free file descriptors.
    219 	 * [ Strange results will ensue if the open file
    220 	 * limit is ever reduced below the current number
    221 	 * of open files... ]
    222 	 */
    223 	lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
    224 	fdp = p->p_fd;
    225 	last = min(fdp->fd_nfiles, lim);
    226 	freefd = 0;
    227 	for (i = fdp->fd_freefile; i < last; i++)
    228 		if (fdp->fd_ofiles[i] == NULL)
    229 			freefd++;
    230 
    231 	/*
    232 	 * Adjust for the fact that the fdesc array may not
    233 	 * have been fully allocated yet.
    234 	 */
    235 	if (fdp->fd_nfiles < lim)
    236 		freefd += (lim - fdp->fd_nfiles);
    237 
    238 	sbp->f_bsize = DEV_BSIZE;
    239 	sbp->f_iosize = DEV_BSIZE;
    240 	sbp->f_blocks = 2;		/* 1K to keep df happy */
    241 	sbp->f_bfree = 0;
    242 	sbp->f_bavail = 0;
    243 	sbp->f_files = lim + 1;		/* Allow for "." */
    244 	sbp->f_ffree = freefd;		/* See comments above */
    245 #ifdef COMPAT_09
    246 	sbp->f_type = 6;
    247 #else
    248 	sbp->f_type = 0;
    249 #endif
    250 	if (sbp != &mp->mnt_stat) {
    251 		memcpy(&sbp->f_fsid, &mp->mnt_stat.f_fsid, sizeof(sbp->f_fsid));
    252 		memcpy(sbp->f_mntonname, mp->mnt_stat.f_mntonname, MNAMELEN);
    253 		memcpy(sbp->f_mntfromname, mp->mnt_stat.f_mntfromname, MNAMELEN);
    254 	}
    255 	strncpy(sbp->f_fstypename, mp->mnt_op->vfs_name, MFSNAMELEN);
    256 	return (0);
    257 }
    258 
    259 /*ARGSUSED*/
    260 int
    261 fdesc_sync(mp, waitfor, uc, p)
    262 	struct mount *mp;
    263 	int waitfor;
    264 	struct ucred *uc;
    265 	struct proc *p;
    266 {
    267 
    268 	return (0);
    269 }
    270 
    271 /*
    272  * Fdesc flat namespace lookup.
    273  * Currently unsupported.
    274  */
    275 int
    276 fdesc_vget(mp, ino, vpp)
    277 	struct mount *mp;
    278 	ino_t ino;
    279 	struct vnode **vpp;
    280 {
    281 
    282 	return (EOPNOTSUPP);
    283 }
    284 
    285 
    286 /*ARGSUSED*/
    287 int
    288 fdesc_fhtovp(mp, fhp, vpp)
    289 	struct mount *mp;
    290 	struct fid *fhp;
    291 	struct vnode **vpp;
    292 {
    293 
    294 	return (EOPNOTSUPP);
    295 }
    296 
    297 /*ARGSUSED*/
    298 int
    299 fdesc_checkexp(mp, nam, exflagsp, credanonp)
    300 	struct mount *mp;
    301 	struct mbuf *nam;
    302 	int *exflagsp;
    303 	struct ucred **credanonp;
    304 {
    305 
    306 	return (EOPNOTSUPP);
    307 }
    308 
    309 /*ARGSUSED*/
    310 int
    311 fdesc_vptofh(vp, fhp)
    312 	struct vnode *vp;
    313 	struct fid *fhp;
    314 {
    315 	return (EOPNOTSUPP);
    316 }
    317 
    318 int
    319 fdesc_sysctl(name, namelen, oldp, oldlenp, newp, newlen, p)
    320 	int *name;
    321 	u_int namelen;
    322 	void *oldp;
    323 	size_t *oldlenp;
    324 	void *newp;
    325 	size_t newlen;
    326 	struct proc *p;
    327 {
    328 	return (EOPNOTSUPP);
    329 }
    330 
    331 extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc;
    332 
    333 const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = {
    334 	&fdesc_vnodeop_opv_desc,
    335 	NULL,
    336 };
    337 
    338 struct vfsops fdesc_vfsops = {
    339 	MOUNT_FDESC,
    340 	fdesc_mount,
    341 	fdesc_start,
    342 	fdesc_unmount,
    343 	fdesc_root,
    344 	fdesc_quotactl,
    345 	fdesc_statfs,
    346 	fdesc_sync,
    347 	fdesc_vget,
    348 	fdesc_fhtovp,
    349 	fdesc_vptofh,
    350 	fdesc_init,
    351 	NULL,
    352 	fdesc_done,
    353 	fdesc_sysctl,
    354 	NULL,				/* vfs_mountroot */
    355 	fdesc_checkexp,
    356 	fdesc_vnodeopv_descs,
    357 };
    358