NetBSD/sys/miscfs/fdesc/fdesc_vfsops.c

308 lines
7.3 KiB
C

/* $NetBSD: fdesc_vfsops.c,v 1.64 2007/01/19 14:49:10 hannken Exp $ */
/*
* Copyright (c) 1992, 1993, 1995
* The Regents of the University of California. 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. 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 8.10 (Berkeley) 5/14/95
*
* #Id: fdesc_vfsops.c,v 1.9 1993/04/06 15:28:33 jsp Exp #
*/
/*
* /dev/fd Filesystem
*/
#include <sys/cdefs.h>
__KERNEL_RCSID(0, "$NetBSD: fdesc_vfsops.c,v 1.64 2007/01/19 14:49:10 hannken Exp $");
#if defined(_KERNEL_OPT)
#include "opt_compat_netbsd.h"
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/sysctl.h>
#include <sys/time.h>
#include <sys/proc.h>
#include <sys/resourcevar.h>
#include <sys/filedesc.h>
#include <sys/vnode.h>
#include <sys/mount.h>
#include <sys/dirent.h>
#include <sys/namei.h>
#include <sys/malloc.h>
#include <sys/kauth.h>
#include <miscfs/fdesc/fdesc.h>
int fdesc_mount(struct mount *, const char *, void *,
struct nameidata *, struct lwp *);
int fdesc_start(struct mount *, int, struct lwp *);
int fdesc_unmount(struct mount *, int, struct lwp *);
int fdesc_quotactl(struct mount *, int, uid_t, void *,
struct lwp *);
int fdesc_statvfs(struct mount *, struct statvfs *, struct lwp *);
int fdesc_sync(struct mount *, int, kauth_cred_t, struct lwp *);
int fdesc_vget(struct mount *, ino_t, struct vnode **);
/*
* Mount the per-process file descriptors (/dev/fd)
*/
int
fdesc_mount(struct mount *mp, const char *path, void *data,
struct nameidata *ndp, struct lwp *l)
{
int error = 0;
struct fdescmount *fmp;
struct vnode *rvp;
if (mp->mnt_flag & MNT_GETARGS)
return 0;
/*
* 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;
fmp->f_root = rvp;
mp->mnt_stat.f_namemax = MAXNAMLEN;
mp->mnt_flag |= MNT_LOCAL;
mp->mnt_data = fmp;
vfs_getnewfsid(mp);
error = set_statvfs_info(path, UIO_USERSPACE, "fdesc", UIO_SYSSPACE,
mp, l);
VOP_UNLOCK(rvp, 0);
return error;
}
int
fdesc_start(struct mount *mp, int flags,
struct lwp *l)
{
return (0);
}
int
fdesc_unmount(struct mount *mp, int mntflags, struct lwp *l)
{
int error;
int flags = 0;
struct vnode *rtvp = VFSTOFDESC(mp)->f_root;
if (mntflags & MNT_FORCE)
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 (rtvp->v_usecount > 1)
return (EBUSY);
if ((error = vflush(mp, rtvp, flags)) != 0)
return (error);
/*
* Release reference on underlying root vnode
*/
vrele(rtvp);
/*
* And blow it away for future re-use
*/
vgone(rtvp);
/*
* Finally, throw away the fdescmount structure
*/
free(mp->mnt_data, M_UFSMNT); /* XXX */
mp->mnt_data = 0;
return (0);
}
int
fdesc_root(mp, vpp)
struct mount *mp;
struct vnode **vpp;
{
struct vnode *vp;
/*
* Return locked reference to root.
*/
vp = VFSTOFDESC(mp)->f_root;
VREF(vp);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY);
*vpp = vp;
return (0);
}
int
fdesc_quotactl(struct mount *mp, int cmd, uid_t uid,
void *arg, struct lwp *l)
{
return (EOPNOTSUPP);
}
int
fdesc_statvfs(mp, sbp, l)
struct mount *mp;
struct statvfs *sbp;
struct lwp *l;
{
struct filedesc *fdp;
struct proc *p;
int lim;
int i;
int last;
int freefd;
/*
* 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... ]
*/
p = l->l_proc;
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_bsize = DEV_BSIZE;
sbp->f_frsize = 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_bresvd = 0;
sbp->f_files = lim + 1; /* Allow for "." */
sbp->f_ffree = freefd; /* See comments above */
sbp->f_favail = freefd; /* See comments above */
sbp->f_fresvd = 0;
copy_statvfs_info(sbp, mp);
return (0);
}
/*ARGSUSED*/
int
fdesc_sync(struct mount *mp, int waitfor,
kauth_cred_t uc, struct lwp *l)
{
return (0);
}
/*
* Fdesc flat namespace lookup.
* Currently unsupported.
*/
int
fdesc_vget(struct mount *mp, ino_t ino,
struct vnode **vpp)
{
return (EOPNOTSUPP);
}
SYSCTL_SETUP(sysctl_vfs_fdesc_setup, "sysctl vfs.fdesc subtree setup")
{
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "vfs", NULL,
NULL, 0, NULL, 0,
CTL_VFS, CTL_EOL);
sysctl_createv(clog, 0, NULL, NULL,
CTLFLAG_PERMANENT,
CTLTYPE_NODE, "fdesc",
SYSCTL_DESCR("File-descriptor file system"),
NULL, 0, NULL, 0,
CTL_VFS, 7, CTL_EOL);
/*
* XXX the "7" above could be dynamic, thereby eliminating one
* more instance of the "number to vfs" mapping problem, but
* "7" is the order as taken from sys/mount.h
*/
}
extern const struct vnodeopv_desc fdesc_vnodeop_opv_desc;
const struct vnodeopv_desc * const fdesc_vnodeopv_descs[] = {
&fdesc_vnodeop_opv_desc,
NULL,
};
struct vfsops fdesc_vfsops = {
MOUNT_FDESC,
fdesc_mount,
fdesc_start,
fdesc_unmount,
fdesc_root,
fdesc_quotactl,
fdesc_statvfs,
fdesc_sync,
fdesc_vget,
(void *)eopnotsupp, /* vfs_fhtovp */
(void *)eopnotsupp, /* vfs_vptofh */
fdesc_init,
NULL,
fdesc_done,
NULL, /* vfs_mountroot */
(int (*)(struct mount *, struct vnode *, struct timespec *)) eopnotsupp,
vfs_stdextattrctl,
vfs_stdsuspendctl,
fdesc_vnodeopv_descs,
0,
{ NULL, NULL},
};
VFS_ATTACH(fdesc_vfsops);