4.4BSD/usr/src/sys/miscfs/fdesc/fdesc_vfsops.c
/*
* Copyright (c) 1992, 1993
* The Regents of the University of California. All rights reserved.
* All rights reserved.
*
* This code is derived from software donated to Berkeley by
* Jan-Simon Pendry.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* 3. All advertising materials mentioning features or use of this software
* must display the following acknowledgement:
* This product includes software developed by the University of
* California, Berkeley and its contributors.
* 4. Neither the name of the University nor the names of its contributors
* may be used to endorse or promote products derived from this software
* without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
* FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
* DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
* OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
* HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
* LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
* OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
*
* @(#)fdesc_vfsops.c 8.1 (Berkeley) 6/10/93
*
* $Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp $
*/
/*
* /dev/fd Filesystem
*/
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/time.h>
#include <sys/types.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <miscfs/fdesc/fdesc.h>
dev_t devctty;
fdesc_init()
{
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_init\n"); /* printed during system boot */
#endif
devctty = makedev(nchrdev, 0);
}
/*
* Mount the per-process file descriptors (/dev/fd)
*/
fdesc_mount(mp, path, data, ndp, p)
struct mount *mp;
char *path;
caddr_t data;
struct nameidata *ndp;
struct proc *p;
{
int error = 0;
u_int size;
struct fdescmount *fmp;
struct vnode *rvp;
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_mount(mp = %x)\n", mp);
#endif
/*
* Update is a no-op
*/
if (mp->mnt_flag & MNT_UPDATE)
return (EOPNOTSUPP);
error = fdesc_allocvp(Froot, FD_ROOT, mp, &rvp);
if (error)
return (error);
MALLOC(fmp, struct fdescmount *, sizeof(struct fdescmount),
M_UFSMNT, M_WAITOK); /* XXX */
rvp->v_type = VDIR;
rvp->v_flag |= VROOT;
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_mount: root vp = %x\n", rvp);
#endif
fmp->f_root = rvp;
/* XXX -- don't mark as local to work around fts() problems */
/*mp->mnt_flag |= MNT_LOCAL;*/
mp->mnt_data = (qaddr_t) fmp;
getnewfsid(mp, MOUNT_FDESC);
(void) copyinstr(path, mp->mnt_stat.f_mntonname, MNAMELEN - 1, &size);
bzero(mp->mnt_stat.f_mntonname + size, MNAMELEN - size);
bzero(mp->mnt_stat.f_mntfromname, MNAMELEN);
bcopy("fdesc", mp->mnt_stat.f_mntfromname, sizeof("fdesc"));
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_mount: at %s\n", mp->mnt_stat.f_mntonname);
#endif
return (0);
}
fdesc_start(mp, flags, p)
struct mount *mp;
int flags;
struct proc *p;
{
return (0);
}
fdesc_unmount(mp, mntflags, p)
struct mount *mp;
int mntflags;
struct proc *p;
{
int error;
int flags = 0;
extern int doforce;
struct vnode *rootvp = VFSTOFDESC(mp)->f_root;
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_unmount(mp = %x)\n", mp);
#endif
if (mntflags & MNT_FORCE) {
/* fdesc can never be rootfs so don't check for it */
if (!doforce)
return (EINVAL);
flags |= FORCECLOSE;
}
/*
* Clear out buffer cache. I don't think we
* ever get anything cached at this level at the
* moment, but who knows...
*/
#if 0
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_unmount: calling mntflushbuf\n");
#endif
mntflushbuf(mp, 0);
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_unmount: calling mntinvalbuf\n");
#endif
if (mntinvalbuf(mp, 1))
return (EBUSY);
#endif
if (rootvp->v_usecount > 1)
return (EBUSY);
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_unmount: calling vflush\n");
#endif
if (error = vflush(mp, rootvp, flags))
return (error);
#ifdef FDESC_DIAGNOSTIC
vprint("fdesc root", rootvp);
#endif
/*
* Release reference on underlying root vnode
*/
vrele(rootvp);
/*
* And blow it away for future re-use
*/
vgone(rootvp);
/*
* Finally, throw away the fdescmount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return 0;
}
fdesc_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct vnode *vp;
int error;
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_root(mp = %x)\n", mp);
#endif
/*
* Return locked reference to root.
*/
vp = VFSTOFDESC(mp)->f_root;
VREF(vp);
VOP_LOCK(vp);
*vpp = vp;
return (0);
}
fdesc_quotactl(mp, cmd, uid, arg, p)
struct mount *mp;
int cmd;
uid_t uid;
caddr_t arg;
struct proc *p;
{
return (EOPNOTSUPP);
}
fdesc_statfs(mp, sbp, p)
struct mount *mp;
struct statfs *sbp;
struct proc *p;
{
struct filedesc *fdp;
int lim;
int i;
int last;
int freefd;
#ifdef FDESC_DIAGNOSTIC
printf("fdesc_statfs(mp = %x)\n", mp);
#endif
/*
* Compute number of free file descriptors.
* [ Strange results will ensue if the open file
* limit is ever reduced below the current number
* of open files... ]
*/
lim = p->p_rlimit[RLIMIT_NOFILE].rlim_cur;
fdp = p->p_fd;
last = min(fdp->fd_nfiles, lim);
freefd = 0;
for (i = fdp->fd_freefile; i < last; i++)
if (fdp->fd_ofiles[i] == NULL)
freefd++;
/*
* Adjust for the fact that the fdesc array may not
* have been fully allocated yet.
*/
if (fdp->fd_nfiles < lim)
freefd += (lim - fdp->fd_nfiles);
sbp->f_type = MOUNT_FDESC;
sbp->f_flags = 0;
sbp->f_bsize = DEV_BSIZE;
sbp->f_iosize = DEV_BSIZE;
sbp->f_blocks = 2; /* 1K to keep df happy */
sbp->f_bfree = 0;
sbp->f_bavail = 0;
sbp->f_files = lim + 1; /* Allow for "." */
sbp->f_ffree = freefd; /* See comments above */
if (sbp != &mp->mnt_stat) {
bcopy(&mp->mnt_stat.f_fsid, &sbp->f_fsid, sizeof(sbp->f_fsid));
bcopy(mp->mnt_stat.f_mntonname, sbp->f_mntonname, MNAMELEN);
bcopy(mp->mnt_stat.f_mntfromname, sbp->f_mntfromname, MNAMELEN);
}
return (0);
}
fdesc_sync(mp, waitfor)
struct mount *mp;
int waitfor;
{
return (0);
}
/*
* Fdesc flat namespace lookup.
* Currently unsupported.
*/
fdesc_vget(mp, ino, vpp)
struct mount *mp;
ino_t ino;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
fdesc_fhtovp(mp, fhp, setgen, vpp)
struct mount *mp;
struct fid *fhp;
int setgen;
struct vnode **vpp;
{
return (EOPNOTSUPP);
}
fdesc_vptofh(vp, fhp)
struct vnode *vp;
struct fid *fhp;
{
return (EOPNOTSUPP);
}
struct vfsops fdesc_vfsops = {
fdesc_mount,
fdesc_start,
fdesc_unmount,
fdesc_root,
fdesc_quotactl,
fdesc_statfs,
fdesc_sync,
fdesc_vget,
fdesc_fhtovp,
fdesc_vptofh,
fdesc_init,
};