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Use a more robust scheme for determining how many blocks to skip

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after an EOT-terminated volume. We keep track of the current record
number, and synchronise it with the c_tapea field each time we read
a header. Avoid the use of c_firstrec because some bugs in dump can
cause it to be set incorrectly.

Move the initialisation of some variables to avoid compiler warnings.
This commit is contained in:
Ian Dowse 2002-02-18 02:29:47 +00:00
parent 939bc65715
commit ab3d6ee098
1 changed files with 18 additions and 15 deletions
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33
sbin/restore/tape.c
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@ -74,7 +74,7 @@ static int numtrec;
static char *tapebuf;
static union u_spcl endoftapemark;
static long blksread; /* blocks read since last header */
static long tpblksread = 0; /* TP_BSIZE blocks read */
static long tapeaddr = 0; /* current TP_BSIZE tape record */
static long tapesread;
static jmp_buf restart;
static int gettingfile = 0; /* restart has a valid frame */
@ -211,7 +211,6 @@ setup()
if (gethead(&spcl) == FAIL) {
blkcnt--; /* push back this block */
blksread--;
tpblksread--;
cvtflag++;
if (gethead(&spcl) == FAIL) {
fprintf(stderr, "Tape is not a dump tape\n");
@ -300,7 +299,7 @@ void
getvol(nextvol)
long nextvol;
{
long newvol, savecnt, savetpcnt, i;
long newvol, prevtapea, savecnt, i;
union u_spcl tmpspcl;
# define tmpbuf tmpspcl.s_spcl
char buf[TP_BSIZE];
@ -309,6 +308,8 @@ getvol(nextvol)
tapesread = 0;
gettingfile = 0;
}
prevtapea = tapeaddr;
savecnt = blksread;
if (pipein) {
if (nextvol != 1) {
panic("Changing volumes on pipe input?\n");
@ -320,10 +321,7 @@ getvol(nextvol)
return;
goto gethdr;
}
savecnt = blksread;
savetpcnt = tpblksread;
again:
tpblksread = savetpcnt;
if (pipein)
done(1); /* pipes do not get a second chance */
if (command == 'R' || command == 'r' || curfile.action != SKIP)
@ -425,11 +423,10 @@ gethdr:
* If coming to this volume at random, skip to the beginning
* of the next record.
*/
dprintf(stdout, "read %ld recs, tape starts with %ld\n",
tpblksread, tmpbuf.c_firstrec);
dprintf(stdout, "last rec %ld, tape starts with %ld\n", prevtapea,
tmpbuf.c_tapea);
if (tmpbuf.c_type == TS_TAPE && (tmpbuf.c_flags & DR_NEWHEADER)) {
if (curfile.action != USING) {
tpblksread = tmpbuf.c_firstrec;
/*
* XXX Dump incorrectly sets c_count to 1 in the
* volume header of the first tape, so ignore
@ -438,12 +435,17 @@ gethdr:
if (volno != 1)
for (i = tmpbuf.c_count; i > 0; i--)
readtape(buf);
} else if (tmpbuf.c_firstrec > 0 &&
tmpbuf.c_firstrec < tpblksread - 1) {
} else if (tmpbuf.c_tapea <= prevtapea) {
/*
* -1 since we've read the volume header
* Normally the value of c_tapea in the volume
* header is the record number of the header itself.
* However in the volume header following an EOT-
* terminated tape, it is the record number of the
* first continuation data block (dump bug?).
*
* The next record we want is `prevtapea + 1'.
*/
i = tpblksread - tmpbuf.c_firstrec - 1;
i = prevtapea + 1 - tmpbuf.c_tapea;
dprintf(stderr, "Skipping %ld duplicate record%s.\n",
i, i > 1 ? "s" : "");
while (--i >= 0)
@ -855,7 +857,7 @@ readtape(buf)
if (blkcnt < numtrec) {
memmove(buf, &tapebuf[(blkcnt++ * TP_BSIZE)], (long)TP_BSIZE);
blksread++;
tpblksread++;
tapeaddr++;
return;
}
for (i = 0; i < ntrec; i++)
@ -961,7 +963,7 @@ getmore:
blkcnt = 0;
memmove(buf, &tapebuf[(blkcnt++ * TP_BSIZE)], (long)TP_BSIZE);
blksread++;
tpblksread++;
tapeaddr++;
}
static void
@ -1153,6 +1155,7 @@ good:
buf->c_dinode.di_uid = buf->c_dinode.di_ouid;
buf->c_dinode.di_gid = buf->c_dinode.di_ogid;
}
tapeaddr = buf->c_tapea;
if (dflag)
accthdr(buf);
return(GOOD);