/* $OpenBSD: spec_vnops.c,v 1.43 2007/06/18 08:30:07 jasper Exp $ */
/* $NetBSD: spec_vnops.c,v 1.29 1996/04/22 01:42:38 christos Exp $ */
/*
* Copyright (c) 1989, 1993
* The Regents of the University of California. All rights reserved.
*
* 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.
*
* @(#)spec_vnops.c 8.8 (Berkeley) 11/21/94
*/
#include <sys/param.h>
#include <sys/proc.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/conf.h>
#include <sys/buf.h>
#include <sys/mount.h>
#include <sys/namei.h>
#include <sys/vnode.h>
#include <sys/stat.h>
#include <sys/errno.h>
#include <sys/ioctl.h>
#include <sys/file.h>
#include <sys/disklabel.h>
#include <sys/lockf.h>
#include <sys/poll.h>
#include <miscfs/specfs/specdev.h>
#define v_lastr v_specinfo->si_lastr
struct vnode *speclisth[SPECHSZ];
int (**spec_vnodeop_p)(void *);
struct vnodeopv_entry_desc spec_vnodeop_entries[] = {
{ &vop_default_desc, vn_default_error },
{ &vop_lookup_desc, spec_lookup }, /* lookup */
{ &vop_create_desc, spec_create }, /* create */
{ &vop_mknod_desc, spec_mknod }, /* mknod */
{ &vop_open_desc, spec_open }, /* open */
{ &vop_close_desc, spec_close }, /* close */
{ &vop_access_desc, spec_access }, /* access */
{ &vop_getattr_desc, spec_getattr }, /* getattr */
{ &vop_setattr_desc, spec_setattr }, /* setattr */
{ &vop_read_desc, spec_read }, /* read */
{ &vop_write_desc, spec_write }, /* write */
{ &vop_ioctl_desc, spec_ioctl }, /* ioctl */
{ &vop_poll_desc, spec_poll }, /* poll */
{ &vop_kqfilter_desc, spec_kqfilter }, /* kqfilter */
{ &vop_revoke_desc, spec_revoke }, /* revoke */
{ &vop_fsync_desc, spec_fsync }, /* fsync */
{ &vop_remove_desc, spec_remove }, /* remove */
{ &vop_link_desc, spec_link }, /* link */
{ &vop_rename_desc, spec_rename }, /* rename */
{ &vop_mkdir_desc, spec_mkdir }, /* mkdir */
{ &vop_rmdir_desc, spec_rmdir }, /* rmdir */
{ &vop_symlink_desc, spec_symlink }, /* symlink */
{ &vop_readdir_desc, spec_readdir }, /* readdir */
{ &vop_readlink_desc, spec_readlink }, /* readlink */
{ &vop_abortop_desc, spec_abortop }, /* abortop */
{ &vop_inactive_desc, spec_inactive }, /* inactive */
{ &vop_reclaim_desc, spec_reclaim }, /* reclaim */
{ &vop_lock_desc, spec_lock }, /* lock */
{ &vop_unlock_desc, spec_unlock }, /* unlock */
{ &vop_bmap_desc, spec_bmap }, /* bmap */
{ &vop_strategy_desc, spec_strategy }, /* strategy */
{ &vop_print_desc, spec_print }, /* print */
{ &vop_islocked_desc, spec_islocked }, /* islocked */
{ &vop_pathconf_desc, spec_pathconf }, /* pathconf */
{ &vop_advlock_desc, spec_advlock }, /* advlock */
{ &vop_bwrite_desc, spec_bwrite }, /* bwrite */
{ NULL, NULL }
};
struct vnodeopv_desc spec_vnodeop_opv_desc =
{ &spec_vnodeop_p, spec_vnodeop_entries };
int
spec_vnoperate(void *v)
{
struct vop_generic_args *ap = v;
return (VOCALL(spec_vnodeop_p, ap->a_desc->vdesc_offset, ap));
}
/*
* Trivial lookup routine that always fails.
*/
int
spec_lookup(void *v)
{
struct vop_lookup_args *ap = v;
*ap->a_vpp = NULL;
return (ENOTDIR);
}
/*
* Open a special file.
*/
/* ARGSUSED */
int
spec_open(void *v)
{
struct vop_open_args *ap = v;
struct proc *p = ap->a_p;
struct vnode *vp = ap->a_vp;
struct vnode *bvp;
dev_t bdev;
dev_t dev = (dev_t)vp->v_rdev;
int maj = major(dev);
int error;
/*
* Don't allow open if fs is mounted -nodev.
*/
if (vp->v_mount && (vp->v_mount->mnt_flag & MNT_NODEV))
return (ENXIO);
switch (vp->v_type) {
case VCHR:
if ((u_int)maj >= nchrdev)
return (ENXIO);
if (ap->a_cred != FSCRED && (ap->a_mode & FWRITE)) {
/*
* When running in very secure mode, do not allow
* opens for writing of any disk character devices.
*/
if (securelevel >= 2 && cdevsw[maj].d_type == D_DISK)
return (EPERM);
/*
* When running in secure mode, do not allow opens
* for writing of /dev/mem, /dev/kmem, or character
* devices whose corresponding block devices are
* currently mounted.
*/
if (securelevel >= 1) {
if ((bdev = chrtoblk(dev)) != NODEV &&
vfinddev(bdev, VBLK, &bvp) &&
bvp->v_usecount > 0 &&
(error = vfs_mountedon(bvp)))
return (error);
if (iskmemdev(dev))
return (EPERM);
}
}
if (cdevsw[maj].d_type == D_TTY)
vp->v_flag |= VISTTY;
if (cdevsw[maj].d_flags & D_CLONE)
return (spec_open_clone(ap));
VOP_UNLOCK(vp, 0, p);
error = (*cdevsw[maj].d_open)(dev, ap->a_mode, S_IFCHR, ap->a_p);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
case VBLK:
if ((u_int)maj >= nblkdev)
return (ENXIO);
/*
* When running in very secure mode, do not allow
* opens for writing of any disk block devices.
*/
if (securelevel >= 2 && ap->a_cred != FSCRED &&
(ap->a_mode & FWRITE) && bdevsw[maj].d_type == D_DISK)
return (EPERM);
/*
* Do not allow opens of block devices that are
* currently mounted.
*/
if ((error = vfs_mountedon(vp)) != 0)
return (error);
return ((*bdevsw[maj].d_open)(dev, ap->a_mode, S_IFBLK, ap->a_p));
case VNON:
case VLNK:
case VDIR:
case VREG:
case VBAD:
case VFIFO:
case VSOCK:
break;
}
return (0);
}
/*
* Vnode op for read
*/
/* ARGSUSED */
int
spec_read(void *v)
{
struct vop_read_args *ap = v;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr64_t bn, nextbn, bscale;
int bsize;
struct partinfo dpart;
int n, on, majordev;
int (*ioctl)(dev_t, u_long, caddr_t, int, struct proc *);
int error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_READ)
panic("spec_read mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_read proc");
#endif
if (uio->uio_resid == 0)
return (0);
switch (vp->v_type) {
case VCHR:
VOP_UNLOCK(vp, 0, p);
error = (*cdevsw[major(vp->v_rdev)].d_read)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
case VBLK:
if (uio->uio_offset < 0)
return (EINVAL);
bsize = BLKDEV_IOSIZE;
if ((majordev = major(vp->v_rdev)) < nblkdev &&
(ioctl = bdevsw[majordev].d_ioctl) != NULL &&
(*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
u_int32_t frag =
DISKLABELV1_FFS_FRAG(dpart.part->p_fragblock);
u_int32_t fsize =
DISKLABELV1_FFS_FSIZE(dpart.part->p_fragblock);
if (dpart.part->p_fstype == FS_BSDFFS && frag != 0 &&
fsize != 0)
bsize = frag * fsize;
}
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
n = min((bsize - on), uio->uio_resid);
if (vp->v_lastr + bscale == bn) {
nextbn = bn + bscale;
error = breadn(vp, bn, bsize, &nextbn, &bsize,
1, NOCRED, &bp);
} else
error = bread(vp, bn, bsize, NOCRED, &bp);
vp->v_lastr = bn;
n = min(n, bsize - bp->b_resid);
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
brelse(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_read type");
}
/* NOTREACHED */
}
int
spec_inactive(void *v)
{
struct vop_inactive_args *ap = v;
VOP_UNLOCK(ap->a_vp, 0, ap->a_p);
return (0);
}
/*
* Vnode op for write
*/
/* ARGSUSED */
int
spec_write(void *v)
{
struct vop_write_args *ap = v;
struct vnode *vp = ap->a_vp;
struct uio *uio = ap->a_uio;
struct proc *p = uio->uio_procp;
struct buf *bp;
daddr64_t bn, bscale;
int bsize;
struct partinfo dpart;
int n, on, majordev;
int (*ioctl)(dev_t, u_long, caddr_t, int, struct proc *);
int error = 0;
#ifdef DIAGNOSTIC
if (uio->uio_rw != UIO_WRITE)
panic("spec_write mode");
if (uio->uio_segflg == UIO_USERSPACE && uio->uio_procp != curproc)
panic("spec_write proc");
#endif
switch (vp->v_type) {
case VCHR:
VOP_UNLOCK(vp, 0, p);
error = (*cdevsw[major(vp->v_rdev)].d_write)
(vp->v_rdev, uio, ap->a_ioflag);
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, p);
return (error);
case VBLK:
if (uio->uio_resid == 0)
return (0);
if (uio->uio_offset < 0)
return (EINVAL);
bsize = BLKDEV_IOSIZE;
if ((majordev = major(vp->v_rdev)) < nblkdev &&
(ioctl = bdevsw[majordev].d_ioctl) != NULL &&
(*ioctl)(vp->v_rdev, DIOCGPART, (caddr_t)&dpart, FREAD, p) == 0) {
u_int32_t frag =
DISKLABELV1_FFS_FRAG(dpart.part->p_fragblock);
u_int32_t fsize =
DISKLABELV1_FFS_FSIZE(dpart.part->p_fragblock);
if (dpart.part->p_fstype == FS_BSDFFS && frag != 0 &&
fsize != 0)
bsize = frag * fsize;
}
bscale = btodb(bsize);
do {
bn = btodb(uio->uio_offset) & ~(bscale - 1);
on = uio->uio_offset % bsize;
n = min((bsize - on), uio->uio_resid);
error = bread(vp, bn, bsize, NOCRED, &bp);
n = min(n, bsize - bp->b_resid);
if (error) {
brelse(bp);
return (error);
}
error = uiomove((char *)bp->b_data + on, n, uio);
if (n + on == bsize)
bawrite(bp);
else
bdwrite(bp);
} while (error == 0 && uio->uio_resid > 0 && n != 0);
return (error);
default:
panic("spec_write type");
}
/* NOTREACHED */
}
/*
* Device ioctl operation.
*/
/* ARGSUSED */
int
spec_ioctl(void *v)
{
struct vop_ioctl_args *ap = v;
dev_t dev = ap->a_vp->v_rdev;
int maj = major(dev);
switch (ap->a_vp->v_type) {
case VCHR:
return ((*cdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
ap->a_fflag, ap->a_p));
case VBLK:
return ((*bdevsw[maj].d_ioctl)(dev, ap->a_command, ap->a_data,
ap->a_fflag, ap->a_p));
default:
panic("spec_ioctl");
/* NOTREACHED */
}
}
/* ARGSUSED */
int
spec_poll(void *v)
{
struct vop_poll_args *ap = v;
dev_t dev;
switch (ap->a_vp->v_type) {
default:
return (ap->a_events &
(POLLIN | POLLOUT | POLLRDNORM | POLLWRNORM));
case VCHR:
dev = ap->a_vp->v_rdev;
return (*cdevsw[major(dev)].d_poll)(dev, ap->a_events, ap->a_p);
}
}
/* ARGSUSED */
int
spec_kqfilter(void *v)
{
struct vop_kqfilter_args *ap = v;
dev_t dev;
dev = ap->a_vp->v_rdev;
if (cdevsw[major(dev)].d_flags & D_KQFILTER)
return (*cdevsw[major(dev)].d_kqfilter)(dev, ap->a_kn);
return (1);
}
/*
* Synch buffers associated with a block device
*/
/* ARGSUSED */
int
spec_fsync(void *v)
{
struct vop_fsync_args *ap = v;
struct vnode *vp = ap->a_vp;
struct buf *bp;
struct buf *nbp;
int s;
if (vp->v_type == VCHR)
return (0);
/*
* Flush all dirty buffers associated with a block device.
*/
loop:
s = splbio();
for (bp = LIST_FIRST(&vp->v_dirtyblkhd);
bp != LIST_END(&vp->v_dirtyblkhd); bp = nbp) {
nbp = LIST_NEXT(bp, b_vnbufs);
if ((bp->b_flags & B_BUSY))
continue;
if ((bp->b_flags & B_DELWRI) == 0)
panic("spec_fsync: not dirty");
bremfree(bp);
bp->b_flags |= B_BUSY;
splx(s);
bawrite(bp);
goto loop;
}
if (ap->a_waitfor == MNT_WAIT) {
vwaitforio (vp, 0, "spec_fsync", 0);
#ifdef DIAGNOSTIC
if (!LIST_EMPTY(&vp->v_dirtyblkhd)) {
splx(s);
vprint("spec_fsync: dirty", vp);
goto loop;
}
#endif
}
splx(s);
return (0);
}
int
spec_strategy(void *v)
{
struct vop_strategy_args *ap = v;
struct buf *bp = ap->a_bp;
int maj = major(bp->b_dev);
if (LIST_FIRST(&bp->b_dep) != NULL)
buf_start(bp);
(*bdevsw[maj].d_strategy)(bp);
return (0);
}
/*
* This is a noop, simply returning what one has been given.
*/
int
spec_bmap(void *v)
{
struct vop_bmap_args *ap = v;
if (ap->a_vpp != NULL)
*ap->a_vpp = ap->a_vp;
if (ap->a_bnp != NULL)
*ap->a_bnp = ap->a_bn;
if (ap->a_runp != NULL)
*ap->a_runp = 0;
return (0);
}
/*
* Device close routine
*/
/* ARGSUSED */
int
spec_close(void *v)
{
struct vop_close_args *ap = v;
struct vnode *vp = ap->a_vp;
dev_t dev = vp->v_rdev;
int (*devclose)(dev_t, int, int, struct proc *);
int mode, error;
switch (vp->v_type) {
case VCHR:
/*
* Hack: a tty device that is a controlling terminal
* has a reference from the session structure.
* We cannot easily tell that a character device is
* a controlling terminal, unless it is the closing
* process' controlling terminal. In that case,
* if the reference count is 2 (this last descriptor
* plus the session), release the reference from the session.
*/
if (vcount(vp) == 2 && ap->a_p &&
vp == ap->a_p->p_session->s_ttyvp) {
vrele(vp);
ap->a_p->p_session->s_ttyvp = NULL;
}
/*
* If the vnode is locked, then we are in the midst
* of forcably closing the device, otherwise we only
* close on last reference.
*/
if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
return (0);
if (cdevsw[major(dev)].d_flags & D_CLONE)
return (spec_close_clone(ap));
devclose = cdevsw[major(dev)].d_close;
mode = S_IFCHR;
break;
case VBLK:
/*
* On last close of a block device (that isn't mounted)
* we must invalidate any in core blocks, so that
* we can, for instance, change floppy disks. In order to do
* that, we must lock the vnode. If we are coming from
* vclean(), the vnode is already locked.
*/
if (!(vp->v_flag & VXLOCK))
vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, ap->a_p);
error = vinvalbuf(vp, V_SAVE, ap->a_cred, ap->a_p, 0, 0);
if (!(vp->v_flag & VXLOCK))
VOP_UNLOCK(vp, 0, ap->a_p);
if (error)
return (error);
/*
* We do not want to really close the device if it
* is still in use unless we are trying to close it
* forcibly. Since every use (buffer, vnode, swap, cmap)
* holds a reference to the vnode, and because we mark
* any other vnodes that alias this device, when the
* sum of the reference counts on all the aliased
* vnodes descends to one, we are on last close.
*/
if (vcount(vp) > 1 && (vp->v_flag & VXLOCK) == 0)
return (0);
devclose = bdevsw[major(dev)].d_close;
mode = S_IFBLK;
break;
default:
panic("spec_close: not special");
}
return ((*devclose)(dev, ap->a_fflag, mode, ap->a_p));
}
/*
* Print out the contents of a special device vnode.
*/
int
spec_print(void *v)
{
struct vop_print_args *ap = v;
printf("tag VT_NON, dev %d, %d\n", major(ap->a_vp->v_rdev),
minor(ap->a_vp->v_rdev));
return 0;
}
/*
* Return POSIX pathconf information applicable to special devices.
*/
int
spec_pathconf(void *v)
{
struct vop_pathconf_args *ap = v;
switch (ap->a_name) {
case _PC_LINK_MAX:
*ap->a_retval = LINK_MAX;
return (0);
case _PC_MAX_CANON:
*ap->a_retval = MAX_CANON;
return (0);
case _PC_MAX_INPUT:
*ap->a_retval = MAX_INPUT;
return (0);
case _PC_PIPE_BUF:
*ap->a_retval = PIPE_BUF;
return (0);
case _PC_CHOWN_RESTRICTED:
*ap->a_retval = 1;
return (0);
case _PC_VDISABLE:
*ap->a_retval = _POSIX_VDISABLE;
return (0);
default:
return (EINVAL);
}
/* NOTREACHED */
}
/*
* Special device advisory byte-level locks.
*/
/* ARGSUSED */
int
spec_advlock(void *v)
{
struct vop_advlock_args *ap = v;
struct vnode *vp = ap->a_vp;
return (lf_advlock(&vp->v_speclockf, (off_t)0, ap->a_id,
ap->a_op, ap->a_fl, ap->a_flags));
}
/*
* Special device failed operation
*/
/*ARGSUSED*/
int
spec_ebadf(void *v)
{
return (EBADF);
}
/*
* Special device bad operation
*/
/*ARGSUSED*/
int
spec_badop(void *v)
{
panic("spec_badop called");
/* NOTREACHED */
}
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