/*
* Copyright (c) 1988 University of Utah.
* Copyright (c) 1990, 1993
* The Regents of the University of California. All rights reserved.
*
* This code is derived from software contributed to Berkeley by
* the Systems Programming Group of the University of Utah Computer
* Science Department.
*
* 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.
*
* from: Utah Hdr: vn.c 1.13 94/04/02
*
* @(#)vn.c 8.6 (Berkeley) 4/1/94
*/
/*
* Vnode disk driver.
*
* Block/character interface to a vnode. Allows one to treat a file
* as a disk (e.g. build a filesystem in it, mount it, etc.).
*
* NOTE 1: This uses the VOP_BMAP/VOP_STRATEGY interface to the vnode
* instead of a simple VOP_RDWR. We do this to avoid distorting the
* local buffer cache.
*
* NOTE 2: There is a security issue involved with this driver.
* Once mounted all access to the contents of the "mapped" file via
* the special file is controlled by the permissions on the special
* file, the protection of the mapped file is ignored (effectively,
* by using root credentials in all transactions).
*
* NOTE 3: Doesn't interact with leases, should it?
*/
#include "vn.h"
#if NVN > 0
/* default is to have 8 VN's */
#if NVN < 8
#undef NVN
#define NVN 8
#endif
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/namei.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/ioctl.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/uio.h>
#include <sys/disklabel.h>
#ifdef TEST_LABELLING
#include <sys/diskslice.h>
#include <sys/stat.h>
#endif
#include <miscfs/specfs/specdev.h>
#include <sys/vnioctl.h>
#ifdef DEBUG
int dovncluster = 1;
int vndebug = 0x00;
#define VDB_FOLLOW 0x01
#define VDB_INIT 0x02
#define VDB_IO 0x04
#endif
#ifdef TEST_LABELLING
#define vnunit(dev) dkunit(dev)
#else
#define vnunit(x) (minor(x) >> 3)
#endif
#define getvnbuf() \
((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK))
#define putvnbuf(bp) \
free((caddr_t)(bp), M_DEVBUF)
struct vn_softc {
int sc_flags; /* flags */
size_t sc_size; /* size of vn */
struct vnode *sc_vp; /* vnode */
struct ucred *sc_cred; /* credentials */
int sc_maxactive; /* max # of active requests */
struct buf sc_tab; /* transfer queue */
#ifdef TEST_LABELLING
struct diskslices *sc_slices;
#endif
};
/* sc_flags */
#define VNF_INITED 0x01
struct vn_softc *vn_softc[NVN];
/*
* XXX these decls should be static (without __P(())) or elsewhere.
*/
int vnclose __P((dev_t dev, int flags, int mode, struct proc *p));
int vnopen __P((dev_t dev, int flags, int mode, struct proc *p));
void vnstrategy __P((struct buf *bp));
void vnstart __P((struct vn_softc *vn));
void vniodone __P((struct buf *bp));
int vnioctl __P((dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p));
int vnsetcred __P((struct vn_softc *vn, struct ucred *cred));
void vnthrottle __P((struct vn_softc *vn, struct vnode *vp));
void vnshutdown __P((void));
void vnclear __P((struct vn_softc *vn));
size_t vnsize __P((dev_t dev));
int vndump __P((dev_t dev));
int
vnclose(dev_t dev, int flags, int mode, struct proc *p)
{
struct vn_softc *vn;
vn = vn_softc[vnunit(dev)];
#ifdef TEST_LABELLING
if (vn->sc_slices != NULL)
dsclose(dev, mode, vn->sc_slices);
#endif
vn_softc[vnunit(dev)] = 0;
free(vn, M_DEVBUF);
return (0);
}
int
vnopen(dev_t dev, int flags, int mode, struct proc *p)
{
int unit = vnunit(dev),size;
struct vn_softc *vn;
#ifdef DEBUG
if (vndebug & VDB_FOLLOW)
printf("vnopen(0x%lx, 0x%x, 0x%x, %p)\n", dev, flags, mode, p);
#endif
if (unit >= NVN)
return(ENOENT);
vn = vn_softc[unit];
if (!vn) {
vn = malloc(sizeof *vn, M_DEVBUF, M_WAITOK);
if (!vn)
return (ENOMEM);
bzero(vn, sizeof *vn);
vn_softc[unit] = vn;
}
#ifdef TEST_LABELLING
if (vn->sc_flags & VNF_INITED) {
struct disklabel label;
/* Build label for whole disk. */
bzero(&label, sizeof label);
label.d_secsize = DEV_BSIZE;
label.d_nsectors = 32;
label.d_ntracks = 64;
label.d_ncylinders = vn->sc_size / (32 * 64);
label.d_secpercyl = 32 * 64;
label.d_secperunit = label.d_partitions[RAW_PART].p_size
= vn->sc_size;
return (dsopen("vn", dev, mode, &vn->sc_slices, &label,
vnstrategy, (ds_setgeom_t *)NULL));
}
if (dkslice(dev) != WHOLE_DISK_SLICE || dkpart(dev) != RAW_PART ||
mode != S_IFCHR)
return (ENXIO);
#endif /* TEST_LABELLING */
return(0);
}
/*
* Break the request into bsize pieces and submit using VOP_BMAP/VOP_STRATEGY.
* Note that this driver can only be used for swapping over NFS on the hp
* since nfs_strategy on the vax cannot handle u-areas and page tables.
*/
void
vnstrategy(struct buf *bp)
{
int unit = vnunit(bp->b_dev);
register struct vn_softc *vn = vn_softc[unit];
register struct buf *nbp;
register int bn, bsize, resid;
register caddr_t addr;
int sz, flags, error;
#ifdef DEBUG
if (vndebug & VDB_FOLLOW)
printf("vnstrategy(%p): unit %d\n", bp, unit);
#endif
if ((vn->sc_flags & VNF_INITED) == 0) {
bp->b_error = ENXIO;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
#ifdef TEST_LABELLING
bp->b_resid = bp->b_bcount; /* XXX best place to set this? */
if (vn->sc_slices != NULL && dscheck(bp, vn->sc_slices) <= 0) {
biodone(bp);
return;
}
bn = bp->b_pblkno;
bp->b_resid = bp->b_bcount; /* XXX best place to set this? */
#else /* !TEST_LABELLING */
bn = bp->b_blkno;
sz = howmany(bp->b_bcount, DEV_BSIZE);
bp->b_resid = bp->b_bcount;
if (bn < 0 || bn + sz > vn->sc_size) {
if (bn != vn->sc_size) {
bp->b_error = EINVAL;
bp->b_flags |= B_ERROR;
}
biodone(bp);
return;
}
#endif /* TEST_LABELLING */
bn = dbtob(bn);
bsize = vn->sc_vp->v_mount->mnt_stat.f_iosize;
addr = bp->b_data;
flags = bp->b_flags | B_CALL;
for (resid = bp->b_resid; resid; resid -= sz) {
struct vnode *vp;
daddr_t nbn; /* YYY - bn was int !? */
int off, s, nra;
nra = 0;
error = VOP_BMAP(vn->sc_vp, bn / bsize, &vp, &nbn, &nra);
if (error == 0 && (long)nbn == -1)
error = EIO;
#ifdef DEBUG
if (!dovncluster)
nra = 0;
#endif
off = bn % bsize;
if (off)
sz = bsize - off;
else
sz = (1 + nra) * bsize;
if (resid < sz)
sz = resid;
#ifdef DEBUG
if (vndebug & VDB_IO)
printf("vnstrategy: vp %p/%p bn 0x%x/0x%lx sz 0x%x\n",
vn->sc_vp, vp, bn, nbn, sz);
#endif
nbp = getvnbuf();
nbp->b_flags = flags;
nbp->b_bcount = sz;
nbp->b_bufsize = sz;
nbp->b_error = 0;
if (vp->v_type == VBLK || vp->v_type == VCHR)
nbp->b_dev = vp->v_rdev;
else
nbp->b_dev = NODEV;
nbp->b_data = addr;
nbp->b_blkno = nbn + btodb(off);
nbp->b_proc = bp->b_proc;
nbp->b_iodone = vniodone;
nbp->b_vp = vp;
nbp->b_pfcent = (int) bp; /* XXX */
nbp->b_rcred = vn->sc_cred; /* XXX crdup? */
nbp->b_wcred = vn->sc_cred; /* XXX crdup? */
nbp->b_dirtyoff = bp->b_dirtyoff;
nbp->b_dirtyend = bp->b_dirtyend;
nbp->b_validoff = bp->b_validoff;
nbp->b_validend = bp->b_validend;
/*
* If there was an error or a hole in the file...punt.
* Note that we deal with this after the nbp allocation.
* This ensures that we properly clean up any operations
* that we have already fired off.
*
* XXX we could deal with holes here but it would be
* a hassle (in the write case).
*/
if (error) {
nbp->b_error = error;
nbp->b_flags |= B_ERROR;
bp->b_resid -= (resid - sz);
biodone(nbp);
return;
}
/*
* Just sort by block number
*/
/*
* XXX sort at all? The lowest layer should repeat the sort.
*/
#define b_cylinder b_resid /* XXX */
nbp->b_cylinder = nbp->b_blkno;
s = splbio();
disksort(&vn->sc_tab, nbp);
if (vn->sc_tab.b_active < vn->sc_maxactive) {
vn->sc_tab.b_active++;
vnstart(vn);
}
splx(s);
bn += sz;
addr += sz;
}
}
/*
* Feed requests sequentially.
* We do it this way to keep from flooding NFS servers if we are connected
* to an NFS file. This places the burden on the client rather than the
* server.
*/
void
vnstart(struct vn_softc *vn)
{
register struct buf *bp;
/*
* Dequeue now since lower level strategy routine might
* queue using same links
*/
bp = vn->sc_tab.b_actf;
vn->sc_tab.b_actf = bp->b_actf;
#ifdef DEBUG
if (vndebug & VDB_IO)
printf("vnstart(%d): bp %p vp %p blkno 0x%lx addr %p cnt 0x%lx\n",
0, bp, bp->b_vp, bp->b_blkno, bp->b_data,
bp->b_bcount);
#endif
if ((bp->b_flags & B_READ) == 0)
bp->b_vp->v_numoutput++;
VOP_STRATEGY(bp);
}
void
vniodone(struct buf *bp)
{
register struct buf *pbp = (struct buf *)bp->b_pfcent; /* XXX */
register struct vn_softc *vn = vn_softc[vnunit(pbp->b_dev)];
int s;
s = splbio();
#ifdef DEBUG
if (vndebug & VDB_IO)
printf("vniodone(%d): bp %p vp %p blkno 0x%lx addr %p cnt 0x%lx\n",
0, bp, bp->b_vp, bp->b_blkno, bp->b_data,
bp->b_bcount);
#endif
if (bp->b_error) {
#ifdef DEBUG
if (vndebug & VDB_IO)
printf("vniodone: bp %p error %d\n", bp, bp->b_error);
#endif
pbp->b_flags |= B_ERROR;
pbp->b_error = biowait(bp);
}
pbp->b_resid -= bp->b_bcount;
putvnbuf(bp);
if (pbp->b_resid == 0) {
#ifdef DEBUG
if (vndebug & VDB_IO)
printf("vniodone: pbp %p iodone\n", pbp);
#endif
biodone(pbp);
}
if (vn->sc_tab.b_actf)
vnstart(vn);
else
vn->sc_tab.b_active--;
splx(s);
}
/* ARGSUSED */
int
vnioctl(dev_t dev, u_long cmd, caddr_t data, int flag, struct proc *p)
{
int unit = vnunit(dev);
register struct vn_softc *vn;
struct vn_ioctl *vio;
struct vattr vattr;
struct nameidata nd;
int error;
#ifdef DEBUG
if (vndebug & VDB_FOLLOW)
printf("vnioctl(0x%lx, 0x%lx, %p, 0x%x, %p): unit %d\n",
dev, cmd, data, flag, p, unit);
#endif
#ifdef TEST_LABELLING
vn = vn_softc[unit];
if (vn->sc_slices != NULL) {
error = dsioctl(dev, cmd, data, flag, vn->sc_slices,
vnstrategy, (ds_setgeom_t *)NULL);
if (error != -1)
return (error);
}
if (dkslice(dev) != WHOLE_DISK_SLICE || dkpart(dev) != RAW_PART)
return (ENOTTY);
#endif
error = suser(p->p_ucred, &p->p_acflag);
if (error)
return (error);
vn = vn_softc[unit];
vio = (struct vn_ioctl *)data;
switch (cmd) {
case VNIOCSET:
if (vn->sc_flags & VNF_INITED)
return(EBUSY);
/*
* Always open for read and write.
* This is probably bogus, but it lets vn_open()
* weed out directories, sockets, etc. so we don't
* have to worry about them.
*/
NDINIT(&nd, LOOKUP, FOLLOW, UIO_USERSPACE, vio->vn_file, p);
error = vn_open(&nd, FREAD|FWRITE, 0);
if (error)
return(error);
error = VOP_GETATTR(nd.ni_vp, &vattr, p->p_ucred, p);
if (error) {
VOP_UNLOCK(nd.ni_vp);
(void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p);
return(error);
}
VOP_UNLOCK(nd.ni_vp);
vn->sc_vp = nd.ni_vp;
vn->sc_size = btodb(vattr.va_size); /* note truncation */
error = vnsetcred(vn, p->p_ucred);
if (error) {
(void) vn_close(nd.ni_vp, FREAD|FWRITE, p->p_ucred, p);
return(error);
}
vnthrottle(vn, vn->sc_vp);
vio->vn_size = dbtob(vn->sc_size);
vn->sc_flags |= VNF_INITED;
#ifdef TEST_LABELLING
/*
* Reopen so that `ds' knows which devices are open. If
* this is the first VNIOCSET, then we've guaranteed that
* the device is the cdev and that no other slices or
* labels are open. Otherwise, we rely on VNIOCCLR not
* being abused.
*/
error = vnopen(dev, flag, S_IFCHR, p);
if (error)
vnclear(vn);
#endif
#ifdef DEBUG
if (vndebug & VDB_INIT)
printf("vnioctl: SET vp %p size %x\n",
vn->sc_vp, vn->sc_size);
#endif
break;
case VNIOCCLR:
if ((vn->sc_flags & VNF_INITED) == 0)
return(ENXIO);
/*
* XXX handle i/o in progress. Return EBUSY, or wait, or
* flush the i/o.
* XXX handle multiple opens of the device. Return EBUSY,
* or revoke the fd's.
* How are these problems handled for removable and failing
* hardware devices?
*/
vnclear(vn);
#ifdef DEBUG
if (vndebug & VDB_INIT)
printf("vnioctl: CLRed\n");
#endif
break;
default:
return (ENOTTY);
}
return(0);
}
/*
* Duplicate the current processes' credentials. Since we are called only
* as the result of a SET ioctl and only root can do that, any future access
* to this "disk" is essentially as root. Note that credentials may change
* if some other uid can write directly to the mapped file (NFS).
*/
int
vnsetcred(struct vn_softc *vn, struct ucred *cred)
{
struct uio auio;
struct iovec aiov;
char *tmpbuf;
int error;
vn->sc_cred = crdup(cred);
tmpbuf = malloc(DEV_BSIZE, M_TEMP, M_WAITOK);
/* XXX: Horrible kludge to establish credentials for NFS */
aiov.iov_base = tmpbuf;
aiov.iov_len = min(DEV_BSIZE, dbtob(vn->sc_size));
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = 0;
auio.uio_rw = UIO_READ;
auio.uio_segflg = UIO_SYSSPACE;
auio.uio_resid = aiov.iov_len;
error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred);
free(tmpbuf, M_TEMP);
return (error);
}
/*
* Set maxactive based on FS type
*/
void
vnthrottle(struct vn_softc *vn, struct vnode *vp)
{
#if 0
extern int (**nfsv2_vnodeop_p)();
if (vp->v_op == nfsv2_vnodeop_p)
vn->sc_maxactive = 2;
else
#endif
vn->sc_maxactive = 8;
if (vn->sc_maxactive < 1)
vn->sc_maxactive = 1;
}
void
vnshutdown()
{
int i;
for (i = 0; i < NVN; i++)
if (vn_softc[i] && vn_softc[i]->sc_flags & VNF_INITED)
vnclear(vn_softc[i]);
}
TEXT_SET(cleanup_set, vnshutdown);
void
vnclear(struct vn_softc *vn)
{
register struct vnode *vp = vn->sc_vp;
struct proc *p = curproc; /* XXX */
#ifdef DEBUG
if (vndebug & VDB_FOLLOW)
printf("vnclear(%p): vp %p\n", vn, vp);
#endif
vn->sc_flags &= ~VNF_INITED;
if (vp == (struct vnode *)0)
panic("vnclear: null vp");
(void) vn_close(vp, FREAD|FWRITE, vn->sc_cred, p);
crfree(vn->sc_cred);
vn->sc_vp = (struct vnode *)0;
vn->sc_cred = (struct ucred *)0;
vn->sc_size = 0;
#ifdef TEST_LABELLING
if (vn->sc_slices != NULL)
dsgone(&vn->sc_slices);
#endif
}
size_t
vnsize(dev_t dev)
{
int unit = vnunit(dev);
if (unit >= NVN || (!vn_softc[unit]) ||
(vn_softc[unit]->sc_flags & VNF_INITED) == 0)
return(-1);
return(vn_softc[unit]->sc_size);
}
int
vndump(dev_t dev)
{
return (ENODEV);
}
#endif
