1
0
mirror of https://git.FreeBSD.org/src.git synced 2024-12-25 11:37:56 +00:00
freebsd/sys/dev/vn/vn.c
Poul-Henning Kamp cba8a5ddd3 Make a "DWIM" function for adding [bc]devsw entries for bdev drivers.
Saves about 280 butes of source per driver, 56 bytes in object size
and another 56 bytes moves from data to bss.

No functional change intended nor expected.

GENERIC should be about one k smaller now :-)
1996-07-23 21:52:43 +00:00

650 lines
16 KiB
C

/*
* 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
*
* from: @(#)vn.c 8.6 (Berkeley) 4/1/94
* $Id: vn.c,v 1.36 1996/03/28 15:25:43 bde Exp $
*/
/*
* 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>
#include <sys/diskslice.h>
#include <sys/stat.h>
#include <sys/conf.h>
#ifdef DEVFS
#include <sys/devfsext.h>
#endif /*DEVFS*/
#include <miscfs/specfs/specdev.h>
#include <sys/vnioctl.h>
static d_open_t vnopen;
static d_close_t vnclose;
static d_ioctl_t vnioctl;
static d_dump_t vndump;
static d_psize_t vnsize;
static d_strategy_t vnstrategy;
#define CDEV_MAJOR 43
#define BDEV_MAJOR 15
static struct cdevsw vn_cdevsw;
static struct bdevsw vn_bdevsw =
{ vnopen, vnclose, vnstrategy, vnioctl, /*15*/
vndump, vnsize, 0, "vn", &vn_cdevsw, -1 };
#ifdef DEBUG
int dovncluster = 1;
int vndebug = 0x00;
#define VDB_FOLLOW 0x01
#define VDB_INIT 0x02
#define VDB_IO 0x04
#endif
#define vnunit(dev) dkunit(dev)
#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 */
#if defined(DEVFS) && defined(notyet)
void *sc_bdev; /* devfs token for whole disk */
void *sc_cdev; /* devfs token for raw whole disk */
#endif
struct vnode *sc_vp; /* vnode */
struct ucred *sc_cred; /* credentials */
int sc_maxactive; /* max # of active requests */
struct buf sc_tab; /* transfer queue */
u_long sc_options; /* options */
struct diskslices *sc_slices;
};
/* sc_flags */
#define VNF_INITED 0x01
static struct vn_softc *vn_softc[NVN];
static u_long vn_options;
#define IFOPT(vn,opt) if (((vn)->sc_options|vn_options) & (opt))
static void vniodone (struct buf *bp);
static int vnsetcred (struct vn_softc *vn, struct ucred *cred);
static void vnshutdown (void);
static void vnclear (struct vn_softc *vn);
static int
vnclose(dev_t dev, int flags, int mode, struct proc *p)
{
struct vn_softc *vn = vn_softc[vnunit(dev)];
IFOPT(vn, VN_LABELS)
if (vn->sc_slices != NULL)
dsclose(dev, mode, vn->sc_slices);
return (0);
}
static int
vnopen(dev_t dev, int flags, int mode, struct proc *p)
{
int unit = vnunit(dev);
struct vn_softc *vn;
if (unit >= NVN) {
if (vn_options & VN_FOLLOW)
printf("vnopen(0x%lx, 0x%x, 0x%x, %p)\n",
dev, flags, mode, p);
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;
}
IFOPT(vn, VN_FOLLOW)
printf("vnopen(0x%lx, 0x%x, 0x%x, %p)\n", dev, flags, mode, p);
IFOPT(vn, VN_LABELS) {
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,
&vn_bdevsw, &vn_cdevsw));
}
if (dkslice(dev) != WHOLE_DISK_SLICE ||
dkpart(dev) != RAW_PART ||
mode != S_IFCHR)
return (ENXIO);
}
return(0);
}
/*
* this code does I/O calls through the appropriate VOP entry point...
* unless a swap_pager I/O request is being done. This strategy (-))
* allows for coherency with mmap except in the case of paging. This
* is necessary, because the VOP calls use lots of memory (and actually
* are not extremely efficient -- but we want to keep semantics correct),
* and the pageout daemon gets really unhappy (and so does the rest of the
* system) when it runs out of memory.
*/
static void
vnstrategy(struct buf *bp)
{
int unit = vnunit(bp->b_dev);
register struct vn_softc *vn = vn_softc[unit];
register daddr_t bn;
int error;
long sz;
struct uio auio;
struct iovec aiov;
IFOPT(vn, VN_DEBUG)
printf("vnstrategy(%p): unit %d\n", bp, unit);
if ((vn->sc_flags & VNF_INITED) == 0) {
bp->b_error = ENXIO;
bp->b_flags |= B_ERROR;
biodone(bp);
return;
}
IFOPT(vn, VN_LABELS) {
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 {
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;
}
}
if( (bp->b_flags & B_PAGING) == 0) {
aiov.iov_base = bp->b_data;
aiov.iov_len = bp->b_bcount;
auio.uio_iov = &aiov;
auio.uio_iovcnt = 1;
auio.uio_offset = dbtob(bn);
auio.uio_segflg = UIO_SYSSPACE;
if( bp->b_flags & B_READ)
auio.uio_rw = UIO_READ;
else
auio.uio_rw = UIO_WRITE;
auio.uio_resid = bp->b_bcount;
auio.uio_procp = curproc;
if( bp->b_flags & B_READ)
error = VOP_READ(vn->sc_vp, &auio, 0, vn->sc_cred);
else
error = VOP_WRITE(vn->sc_vp, &auio, 0, vn->sc_cred);
bp->b_resid = auio.uio_resid;
if( error )
bp->b_flags |= B_ERROR;
biodone(bp);
} else {
long bsize, resid;
off_t byten;
int flags;
caddr_t addr;
struct buf *nbp;
nbp = getvnbuf();
byten = 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; ) {
struct vnode *vp;
daddr_t nbn;
int off, s, nra;
nra = 0;
error = VOP_BMAP(vn->sc_vp, (daddr_t)(byten / bsize),
&vp, &nbn, &nra, NULL);
if (error == 0 && nbn == -1)
error = EIO;
IFOPT(vn, VN_DONTCLUSTER)
nra = 0;
off = byten % bsize;
if (off)
sz = bsize - off;
else
sz = (1 + nra) * bsize;
if (resid < sz)
sz = resid;
if (error) {
bp->b_resid -= (resid - sz);
bp->b_flags |= B_ERROR;
biodone(bp);
putvnbuf(nbp);
return;
}
IFOPT(vn,VN_IO)
printf(
/* XXX no %qx in kernel. Synthesize it. */
"vnstrategy: vp %p/%p bn 0x%lx%08lx/0x%lx sz 0x%x\n",
vn->sc_vp, vp, (long)(byten >> 32),
(u_long)byten, nbn, sz);
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_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 ((nbp->b_flags & B_READ) == 0)
nbp->b_vp->v_numoutput++;
VOP_STRATEGY(nbp);
s = splbio();
while ((nbp->b_flags & B_DONE) == 0) {
nbp->b_flags |= B_WANTED;
tsleep(nbp, PRIBIO, "vnwait", 0);
}
splx(s);
if( nbp->b_flags & B_ERROR) {
bp->b_flags |= B_ERROR;
bp->b_resid -= (resid - sz);
biodone(bp);
putvnbuf(nbp);
return;
}
byten += sz;
addr += sz;
resid -= sz;
}
biodone(bp);
putvnbuf(nbp);
}
}
void
vniodone( struct buf *bp) {
bp->b_flags |= B_DONE;
wakeup((caddr_t) bp);
}
/* ARGSUSED */
static int
vnioctl(dev_t dev, int cmd, caddr_t data, int flag, struct proc *p)
{
struct vn_softc *vn = vn_softc[vnunit(dev)];
struct vn_ioctl *vio;
struct vattr vattr;
struct nameidata nd;
int error;
u_long *f;
IFOPT(vn,VN_FOLLOW)
printf("vnioctl(0x%lx, 0x%x, %p, 0x%x, %p): unit %d\n",
dev, cmd, data, flag, p, vnunit(dev));
switch (cmd) {
case VNIOCATTACH:
case VNIOCDETACH:
case VNIOCGSET:
case VNIOCGCLEAR:
case VNIOCUSET:
case VNIOCUCLEAR:
goto vn_specific;
}
IFOPT(vn,VN_LABELS) {
if (vn->sc_slices != NULL) {
error = dsioctl("vn", 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);
}
vn_specific:
error = suser(p->p_ucred, &p->p_acflag);
if (error)
return (error);
vio = (struct vn_ioctl *)data;
f = (u_long*)data;
switch (cmd) {
case VNIOCATTACH:
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);
}
vio->vn_size = dbtob(vn->sc_size);
vn->sc_flags |= VNF_INITED;
IFOPT(vn, VN_LABELS) {
/*
* 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);
}
IFOPT(vn, VN_FOLLOW)
printf("vnioctl: SET vp %p size %x\n",
vn->sc_vp, vn->sc_size);
break;
case VNIOCDETACH:
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);
IFOPT(vn, VN_FOLLOW)
printf("vnioctl: CLRed\n");
break;
case VNIOCGSET:
vn_options |= *f;
*f = vn_options;
break;
case VNIOCGCLEAR:
vn_options &= ~(*f);
*f = vn_options;
break;
case VNIOCUSET:
vn->sc_options |= *f;
*f = vn->sc_options;
break;
case VNIOCUCLEAR:
vn->sc_options &= ~(*f);
*f = vn->sc_options;
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);
}
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 */
IFOPT(vn, VN_FOLLOW)
printf("vnclear(%p): vp=%p\n", vn, vp);
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;
if (vn->sc_slices != NULL)
dsgone(&vn->sc_slices);
}
static int
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);
}
static int
vndump(dev_t dev)
{
return (ENODEV);
}
static vn_devsw_installed = 0;
static void
vn_drvinit(void *unused)
{
#ifdef DEVFS
int mynor;
int unit;
struct vn_softc *vn;
#endif
if( ! vn_devsw_installed ) {
bdevsw_add_generic(BDEV_MAJOR,CDEV_MAJOR, &vn_bdevsw);
vn_devsw_installed = 1;
#ifdef DEVFS
for (unit = 0; unit < NVN; unit++) {
vn = vn_softc[unit];
mynor = dkmakeminor(unit, WHOLE_DISK_SLICE, RAW_PART);
/*
* XXX not saving tokens yet. The vn devices don't
* exist until after they have been opened :-).
*/
devfs_add_devswf(&vn_bdevsw, mynor, DV_BLK,
UID_ROOT, GID_OPERATOR, 0640,
"vn%d", unit);
devfs_add_devswf(&vn_cdevsw, mynor, DV_CHR,
UID_ROOT, GID_OPERATOR, 0640,
"rvn%d", unit);
}
#endif
}
}
SYSINIT(vndev,SI_SUB_DRIVERS,SI_ORDER_MIDDLE+CDEV_MAJOR,vn_drvinit,NULL)
#endif