mouse@mcgill-vision.UUCP (der Mouse ) (06/30/87)
[Comment on the below: it sure as heck isn't seismo, so it must be sun.
I try to avoid that site anyway, as the cwruecmp!sun link has been marked
DEAD in cwruecmp's map for quite a while now. ++bsa]
This is part 1 of 2. Read the README (first thing in the archive) to
see what it's part 1 of. I had to split up even this tiny thing
because someone, either sun or seismo (not sure which), has a 10000
byte limit on mail (yes, only ten thousand bytes).
der Mouse
(mouse@mcgill-vision.uucp)
#! /bin/sh
#
# Shar: Shell Archiver
#
# This archive created Sun Jun 28 17:50:43 1987
# Run this through sh to create:
# README
echo x - README \(5589 characters\)
sed 's/^X//' > README << \SHAR_EOF
Xfiledisk: a pseudo disk driver for UNIX. This driver makes a normal
X file look like a filesystem volume.
X
X Currently in use on 4.3BSD. Originally developed on 4.2BSD,
X but the 4.2 version is buried in the mists of the past, so all
X this says is that it won't take much to make it work on 4.2. I
X have attempted to use a somewhat modified version of this under
X mtXinu 4.3+NFS but unfortunately it keeps crashing the system
X for reasons yet to be discovered. I haven't dared even try to
X make it work on a Sun. I won't, either, until we get source.
X
XYou should have received:
X
X - README (this file)
X - filedisk.c
X - fdconn.c
X - fddisc.c
X
XYou will need to:
X
X - Put filedisk.c somewhere; I'll assume it's in
X ../local/filedisk.c (that's where we have it). If you put
X it somewhere else, change the filename in the next item to
X point to wherever you did put it.
X
X - Put a line
Xlocal/filedisk.c optional memdisk
X in ../conf/files.YOURSYSTEMNAME. For example, our
X configuration is in ../conf/LARRY and the kernel is built in
X ../LARRY; the file with the above line is then
X ../conf/files.LARRY (clear enough?).
X
X - Put a line
Xpseudo-device filedisk 1
X in ../conf/YOURSYSTEMNAME. The 1 specifies how many pseudo
X disk devices you want to configure in; you may want to
X increase it.
X
X - Edit conf.c. This file is in ../vax for VAX and MicroVAX
X configurations and seems to be in ../sun (rather than
X ../machine, which is a link to sun2 or sun3 depending on
X which sort of Sun you have) for Suns. You will need to
X insert the following, somewhere early (before both cdevsw[]
X and bdevsw[]).
X#include "filedisk.h"
X#if NFILEDISK > 0
Xextern int filediskopen();
Xextern int filediskstrategy();
Xextern int filediskread();
Xextern int filediskwrite();
Xextern int filediskioctl();
Xextern int filedisksize();
X#else
X#define filediskopen nodev
X#define filediskstrategy nodev
X#define filediskread nodev
X#define filediskwrite nodev
X#define filediskioctl nodev
X#define filedisksize nodev
X#endif
X Now you need to add a device to each of bdevsw[] and
X cdevsw[]. The bdevsw entry should look like
X { filediskopen, nulldev, filediskstrategy,nodev, /* 10 */
X filedisksize, 0 },
X (the 10 should be changed to whatever number you choose to
X put it at). The cdevsw entry should look like
X filediskopen, nulldev, filediskread, filediskwrite, /* 34 */
X filediskioctl, nulldev, nulldev, 0,
X seltrue, 0,
X again, with the 34 changed to whatever is appropriate.
X
X - add two #define lines to ../h/ioctl.h:
X#define LIOC_FSF_SET _IOW(l,1,char *) /* setup filedisk */
X#define LIOC_FSF_CLEAR _IO(l,2) /* clear filedisk */
X
XYou can now re-run config and rebuild your kernel.
X
XIf I haven't forgotten anything (:-), it should run fine. Test the new
Xkernel. When you are satisfied that adding the filedisk driver hasn't
Xbroken anything else, you can try it out:
X
X - Create entries in /dev. We use /dev/filedisk0 and
X /dev/rfiledisk0 (just 0 since we have just one configured
X in; if we had two, they'd be filedisk0/rfiledisk0 and
X filedisk1/rfiledisk1).
X
X - Compile fdconn.c and fddisc.c; put the binaries wherever you
X feel appropriate. As with any disk drive, the /dev entries
X should be mode xx0, probably mode 600 is best, unless you
X wouldn't mind entrusting all your users with your root
X password. Fdconn and fddisc must be able to open the raw
X device /dev/rfiledisk0 (or rfiledisk1, or 2, or...) in order
X to function.
X
XNow to test it. I should explain what fdconn and fddisc do. Fdconn
Xconnects a pseudo-disk unit to a file; fddisc breaks the connection
Xcreated by fdconn. A pseudo-disk unit must be connected to a file
Xbefore it can do anything useful, of course.
X
XLet's test it by just creating a half-meg file and using that as our
Xfilesystem. First let's create the half-meg file:
X
Xdd if=/dev/full bs=....uh, what, you mean this is the filedisk
Xdistribution rather than the /dev/full driver distribution? ;-)
X
Xyes | dd conv=sync bs=65536 count=8 > bigfile
X
X(65536*8 is 512k; conv=sync makes dd pad each bufferful to the bs=
Xfigure.) After a few seconds, dd will report 0+8 records in, 8+0
Xrecords out. Then you will get a "Broken pipe" message, which you
Xshould ignore. Now we connect this to unit 0:
X
X# fdconn 0 bigfile
X
XNow /dev/filedisk0 and /dev/rfiledisk0 are pseudo-filesystems
Xcontaining lots of junk. Let's make a filesystem there:
X
X# /etc/mkfs /dev/rfiledisk0 1024
X....mkfs messages....
X
XNow sync the disk just to be safe. It works just as well to run fsck
Xon it, I find; but if you do neither, I have had it crash mysteriously
Xsometimes (I suspect that some critical filesystem data, like
Xsuperblocks, is still waiting to be written to the disk, because the
Xmkfs used /dev/rfiledisk0 instead of /dev/filedisk0).
X
X# sync
X
XNow we can mount it somewhere:
X
X# /etc/mount /dev/filedisk0 /mnt
X
XAnd away we go! Note that you pay two penalties for using this driver.
XOne is speed, of course; the other is storage space, since there is all
Xthe usual filesystem overhead. Most of the uses for this driver are
Xsuch that these really don't matter. For example, recently I wanted to
Xbuild a boot tape with a slightly non-standard mini-root filesystem on
Xit. So I just used dd to copy the mini-root off the tape onto a disk
Xfile and then used this driver to mount the mini-root filesystem
Xsomewhere. Then of course it was trivial to arrange things on the
Xmini-root as I wanted them. Then just unmount and run fddisc, and use
Xdd to put it back on tape.
X
X der Mouse
X
X (mouse@mcgill-vision.uucp)
SHAR_EOF
if test 5589 -ne "`wc -c README`"
then
echo shar: error transmitting README \(should have been 5589 characters\)
fi
exit 0
# end of shell archivemouse@mcgill-vision.UUCP (der Mouse ) (06/30/87)
This is part 2 of 2. Read the README (in part 1) to see what it's part
2 of. I had to split up even this tiny thing because someone, either
sun or seismo (not sure which), has a 10000 byte limit on mail (yes,
only ten thousand bytes).
der Mouse
(mouse@mcgill-vision.uucp)
#! /bin/sh
#
# Shar: Shell Archiver
#
# This archive created Sun Jun 28 17:50:43 1987
# Run this through sh to create:
# filedisk.c
# fdconn.c
# fddisc.c
echo x - filedisk.c \(4378 characters\)
sed 's/^X//' > filedisk.c << \SHAR_EOF
X/*
X * Filesystem-in-a-file pseudo-disk driver.
X */
X
X#include "filedisk.h"
X
X#if NFILEDISK > 0
X
X#include "../h/param.h"
X#include "../h/systm.h"
X#include "../h/ioctl.h"
X#include "../h/buf.h"
X#include "../h/conf.h"
X#include "../h/dir.h"
X#include "../h/file.h"
X#include "../h/inode.h"
X#include "../h/namei.h"
X#include "../h/user.h"
X#include "../h/proc.h"
X#include "../h/uio.h"
X#include "../h/mount.h"
X#include "../h/fs.h"
X#include "../h/kernel.h"
X
Xstatic struct fdinfo {
X int alive;
X int unit;
X struct inode *ino;
X int nblocks; } info[NFILEDISK];
Xstatic int didinit = 0;
X
X#define OKUNIT(u) (((u)>=0)&&((u)<NFILEDISK))
X
Xfilediskopen(dev,flag)
Xdev_t dev;
Xint flag;
X{
X int unit;
X
X#ifdef lint
X flag = flag;
X#endif
X if (! didinit)
X { for (unit=0;unit<NFILEDISK;unit++)
X { info[unit].alive = 0;
X info[unit].unit = unit;
X }
X didinit = 1;
X }
X unit = minor(dev);
X if (!OKUNIT(unit))
X { return(ENXIO);
X }
X return(0);
X}
X
Xfilediskstrategy(bp)
Xstruct buf *bp;
X{
X int s;
X
X if (! buf_ok(bp))
X { return;
X }
X s = splhigh();
X splx(s);
X if (s != 0)
X { printf("IPL=%d\n",s);
X panic("filediskstrategy: high ipl\n");
X }
X else
X { doionow(bp);
X }
X}
X
Xfilediskread(dev,uio)
Xdev_t dev;
Xstruct uio *uio;
X{
X static struct buf b;
X int unit;
X
X unit = minor(dev);
X if (!OKUNIT(unit))
X { return(ENXIO);
X }
X return(physio(filediskstrategy,&b,dev,B_READ,minphys,uio));
X}
X
Xfilediskwrite(dev,uio)
Xdev_t dev;
Xstruct uio *uio;
X{
X static struct buf b;
X int unit;
X
X unit = minor(dev);
X if (!OKUNIT(unit))
X { return(ENXIO);
X }
X return(physio(filediskstrategy,&b,dev,B_WRITE,minphys,uio));
X}
X
Xstatic int unit_mounted(unit)
Xint unit;
X{
X struct mount *mp;
X int s;
X dev_t dev;
X
X s = spl4(); /* as long as ipl > 0, (u)mounts can't happen */
X for (mp= &mount[0];mp<&mount[NMOUNT];mp++)
X { if (mp->m_bufp != 0)
X { dev = mp->m_dev;
X if ( (bdevsw[major(dev)].d_strategy == filediskstrategy) &&
X (minor(dev) == unit) )
X { splx(s);
X return(1);
X }
X }
X }
X splx(s);
X return(0);
X}
X
Xfilediskioctl(dev,cmd,data,flag)
Xdev_t dev;
Xint cmd;
Xcaddr_t data;
Xint flag;
X{
X int unit;
X int rv;
X struct inode *ip;
X register struct nameidata *ndp;
X
X#ifdef lint
X flag = flag;
X#endif
X unit = minor(dev);
X rv = EIO;
X switch (cmd)
X { case LIOC_FSF_SET:
X if (! suser())
X { rv = EPERM;
X break;
X }
X if (info[unit].alive)
X { rv = EBUSY;
X break;
X }
X ndp = &u.u_nd;
X ndp->ni_segflg = UIO_USERSPACE;
X ndp->ni_dirp = *(char **)data;
X ndp->ni_nameiop = LOOKUP | FOLLOW;
X ip = namei(ndp);
X if (ip == 0)
X { rv = u.u_error;
X break;
X }
X if ((ip->i_mode&IFMT) != IFREG)
X { iput(ip);
X rv = EINVAL;
X break;
X }
X info[unit].ino = ip;
X info[unit].nblocks = btodb(ip->i_size);
X info[unit].alive = 1;
X iunlock(ip);
X rv = 0;
X break;
X case LIOC_FSF_CLEAR:
X if (! suser())
X { rv = EPERM;
X break;
X }
X if (unit_mounted(unit))
X { rv = EBUSY;
X break;
X }
X if (info[unit].alive)
X { info[unit].alive = 0;
X irele(info[unit].ino);
X rv = 0;
X }
X else
X { rv = ENXIO;
X }
X break;
X }
X return(rv);
X}
X
Xfilediskdump()
X{
X return(ENXIO);
X}
X
Xfiledisksize(dev)
Xdev_t dev;
X{
X int unit;
X
X unit = minor(dev);
X if ((unit < 0) || (unit >= NFILEDISK) || !info[unit].alive)
X { return(-1);
X }
X return(info[unit].nblocks);
X}
X
Xfilediskreset(uban)
Xint uban;
X{
X printf("filedisk reset on %d?\n",uban);
X}
X
Xstatic int buf_ok(bp)
Xstruct buf *bp;
X{
X int unit;
X int nblk;
X
X#define FAIL() return((bp->b_flags|=B_ERROR),(iodone(bp)),0)
X unit = minor(bp->b_dev);
X if (bp->b_bcount & (DEV_BSIZE-1))
X { FAIL();
X }
X nblk = btodb(bp->b_bcount);
X if (! info[unit].alive)
X { FAIL();
X }
X if ( (bp->b_blkno < 0) ||
X (bp->b_blkno+nblk > info[unit].nblocks) )
X { FAIL();
X }
X if (! info[unit].ino)
X { FAIL();
X }
X return(1);
X#undef FAIL
X}
X
Xstatic doionow(bp)
Xstruct buf *bp;
X{
X int unit = minor(bp->b_dev);
X struct inode *ip = info[unit].ino;
X
X ilock(ip);
X if (bp->b_flags & B_READ)
X { bp->b_error = rdwri( UIO_READ,
X ip,
X bp->b_un.b_addr,
X bp->b_bcount,
X dbtob(bp->b_blkno),
X 1,
X &bp->b_resid );
X if (bp->b_error)
X { bp->b_flags |= B_ERROR;
X }
X }
X else
X { bp->b_error = rdwri( UIO_WRITE,
X ip,
X bp->b_un.b_addr,
X bp->b_bcount,
X dbtob(bp->b_blkno),
X 1,
X &bp->b_resid );
X if (bp->b_error)
X { bp->b_flags |= B_ERROR;
X }
X }
X iunlock(ip);
X iodone(bp);
X}
X
X#endif
SHAR_EOF
if test 4378 -ne "`wc -c filedisk.c`"
then
echo shar: error transmitting filedisk.c \(should have been 4378 characters\)
fi
echo x - fdconn.c \(664 characters\)
sed 's/^X//' > fdconn.c << \SHAR_EOF
X#include <stdio.h>
X#include <sys/file.h>
X#include <sys/ioctl.h>
X
Xchar **argvec;
X
X/* usage: fdconn <unit> <filename> */
X
Xchar dname[64];
Xint dfd;
X
Xmain(ac,av)
Xint ac;
Xchar **av;
X{
X int unit;
X
X argvec = av;
X if (ac != 3)
X { fprintf(stderr,"Usage: %s unit file\n",argvec[0]);
X exit(1);
X }
X unit = atoi(av[1]);
X sprintf(dname,"/dev/rfiledisk%d",unit);
X dfd = open(dname,O_RDWR,0);
X if (dfd < 0)
X { fprintf(stderr,"%s: cannot open %s: ",argvec[0],dname);
X perror((char *)0);
X exit(1);
X }
X if (ioctl(dfd,LIOC_FSF_SET,&av[2]) < 0)
X { fprintf(stderr,"%s: cannot connect %s to %s: ",argvec[0],dname,av[2]);
X perror((char *)0);
X exit(1);
X }
X exit(0);
X}
SHAR_EOF
if test 664 -ne "`wc -c fdconn.c`"
then
echo shar: error transmitting fdconn.c \(should have been 664 characters\)
fi
echo x - fddisc.c \(636 characters\)
sed 's/^X//' > fddisc.c << \SHAR_EOF
X#include <stdio.h>
X#include <sys/file.h>
X#include <sys/ioctl.h>
X
Xchar **argvec;
X
X/* usage: fddisc <unit> */
X
Xchar dname[64];
Xint dfd;
X
Xmain(ac,av)
Xint ac;
Xchar **av;
X{
X int unit;
X
X argvec = av;
X if (ac != 2)
X { fprintf(stderr,"Usage: %s unit\n",argvec[0]);
X exit(1);
X }
X unit = atoi(av[1]);
X sprintf(dname,"/dev/rfiledisk%d",unit);
X dfd = open(dname,O_RDWR,0);
X if (dfd < 0)
X { fprintf(stderr,"%s: cannot open %s: ",argvec[0],dname);
X perror((char *)0);
X exit(1);
X }
X if (ioctl(dfd,LIOC_FSF_CLEAR,0) < 0)
X { fprintf(stderr,"%s: cannot disconnect %s: ",argvec[0],dname);
X perror((char *)0);
X exit(1);
X }
X exit(0);
X}
SHAR_EOF
if test 636 -ne "`wc -c fddisc.c`"
then
echo shar: error transmitting fddisc.c \(should have been 636 characters\)
fi
exit 0
# end of shell archive