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/*
* old (V6 and before) PDP-11 Unix filesystem
*/
#include <u.h>
#include <libc.h>
#include <auth.h>
#include <fcall.h>
#include "tapefs.h"
/*
* v6 disk inode
*/
#define V6NADDR 8
#define V6FMT 0160000
#define V6IFREG 0100000
#define V6IFDIR 0140000
#define V6IFCHR 0120000
#define V6IFBLK 0160000
#define V6MODE 0777
#define V6LARGE 010000
#define V6SUPERB 1
#define V6ROOT 1 /* root inode */
#define V6NAMELEN 14
#define BLSIZE 512
#define LINOPB (BLSIZE/sizeof(struct v6dinode))
#define LNINDIR (BLSIZE/sizeof(unsigned short))
struct v6dinode {
unsigned char flags[2];
unsigned char nlinks;
unsigned char uid;
unsigned char gid;
unsigned char hisize;
unsigned char losize[2];
unsigned char addr[V6NADDR][2];
unsigned char atime[4]; /* pdp-11 order */
unsigned char mtime[4]; /* pdp-11 order */
};
struct v6dir {
uchar ino[2];
char name[V6NAMELEN];
};
int tapefile;
Fileinf iget(int ino);
long bmap(Ram *r, long bno);
void getblk(Ram *r, long bno, char *buf);
void
populate(char *name)
{
Fileinf f;
replete = 0;
tapefile = open(name, OREAD);
if (tapefile<0)
error("Can't open argument file");
f = iget(V6ROOT);
ram->perm = f.mode;
ram->mtime = f.mdate;
ram->addr = f.addr;
ram->data = f.data;
ram->ndata = f.size;
}
void
popdir(Ram *r)
{
int i, ino;
char *cp;
struct v6dir *dp;
Fileinf f;
char name[V6NAMELEN+1];
cp = 0;
for (i=0; i<r->ndata; i+=sizeof(struct v6dir)) {
if (i%BLSIZE==0)
cp = doread(r, i, BLSIZE);
dp = (struct v6dir *)(cp+i%BLSIZE);
ino = dp->ino[0] + (dp->ino[1]<<8);
if (strcmp(dp->name, ".")==0 || strcmp(dp->name, "..")==0)
continue;
if (ino==0)
continue;
f = iget(ino);
strncpy(name, dp->name, V6NAMELEN);
name[V6NAMELEN] = '\0';
f.name = name;
popfile(r, f);
}
r->replete = 1;
}
void
dotrunc(Ram *r)
{
USED(r);
}
void
docreate(Ram *r)
{
USED(r);
}
char *
doread(Ram *r, vlong off, long cnt)
{
static char buf[Maxbuf+BLSIZE];
int bno, i;
bno = off/BLSIZE;
off -= bno*BLSIZE;
if (cnt>Maxbuf)
error("count too large");
if (off)
cnt += off;
i = 0;
while (cnt>0) {
getblk(r, bno, &buf[i*BLSIZE]);
cnt -= BLSIZE;
bno++;
i++;
}
return buf;
}
void
dowrite(Ram *r, char *buf, long off, long cnt)
{
USED(r); USED(buf); USED(off); USED(cnt);
}
int
dopermw(Ram *r)
{
USED(r);
return 0;
}
/*
* fetch an i-node
* -- no sanity check for now
* -- magic inode-to-disk-block stuff here
*/
Fileinf
iget(int ino)
{
char buf[BLSIZE];
struct v6dinode *dp;
long flags, i;
Fileinf f;
memset(&f, 0, sizeof f);
seek(tapefile, BLSIZE*((ino-1)/LINOPB + V6SUPERB + 1), 0);
if (read(tapefile, buf, BLSIZE) != BLSIZE)
error("Can't read inode");
dp = ((struct v6dinode *)buf) + ((ino-1)%LINOPB);
flags = (dp->flags[1]<<8) + dp->flags[0];
f.size = (dp->hisize << 16) + (dp->losize[1]<<8) + dp->losize[0];
if ((flags&V6FMT)==V6IFCHR || (flags&V6FMT)==V6IFBLK)
f.size = 0;
f.data = emalloc(V6NADDR*sizeof(ushort));
for (i = 0; i < V6NADDR; i++)
((ushort*)f.data)[i] = (dp->addr[i][1]<<8) + dp->addr[i][0];
f.mode = flags & V6MODE;
if ((flags&V6FMT)==V6IFDIR)
f.mode |= DMDIR;
f.uid = dp->uid;
f.gid = dp->gid;
f.mdate = (dp->mtime[2]<<0) + (dp->mtime[3]<<8)
+(dp->mtime[0]<<16) + (dp->mtime[1]<<24);
return f;
}
void
getblk(Ram *r, long bno, char *buf)
{
long dbno;
if ((dbno = bmap(r, bno)) == 0) {
memset(buf, 0, BLSIZE);
return;
}
seek(tapefile, dbno*BLSIZE, 0);
if (read(tapefile, buf, BLSIZE) != BLSIZE)
error("bad read");
}
/*
* logical to physical block
* only singly-indirect files for now
*/
long
bmap(Ram *r, long bno)
{
unsigned char indbuf[LNINDIR][2];
if (r->ndata <= V6NADDR*BLSIZE) { /* assume size predicts largeness of file */
if (bno < V6NADDR)
return ((ushort*)r->data)[bno];
return 0;
}
if (bno < V6NADDR*LNINDIR) {
seek(tapefile, ((ushort *)r->data)[bno/LNINDIR]*BLSIZE, 0);
if (read(tapefile, (char *)indbuf, BLSIZE) != BLSIZE)
return 0;
return ((indbuf[bno%LNINDIR][1]<<8) + indbuf[bno%LNINDIR][0]);
}
return 0;
}
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