#!/usr/pkg/bin/perl

#
# Use dumplfs to find all locations of the Ifile inode on a given disk.
# Order these by serial number and call fsck_lfs on the raw disk for each.
# If any fsck gives errors (lines containing "!", with a few exceptions)
# print an error code with the daddr of the failing Ifile inode location.
#

$| = 1;
$rdev = $ARGV[0];
$gfile = $ARGV[1];
$wfile = $ARGV[2];
$sstart = $ARGV[3];
$rollid = 0;
open(DUMPLFS, "dumplfs $rdev |");

# Look for "roll_id" so we don't use garbage
while (<DUMPLFS>) {
	if ($ssize == 0 && m/ssize *([0-9]*)/) {
		$ssize = $1;
	}
	if ($fsize == 0 && m/fsize *([0-9]*)/) {
		$fsize = $1;
	}
	if (m/roll_id *([x0-9a-f]*)/) {
		$rollid = $1;
		last;
	}
}

# Now look for inodes and segment summaries.  Build a hash table of these
# based on serial number.  Ignore any with serial numbers lower than $sstart.

%iloc = ();
%snloc = ();
%sumloc = ();
print "Reading segments:";
while (<DUMPLFS>) {
	if (m/roll_id *([0-9a-f]*)/) {
		# print "rollid $1\n";
		if ("0x$1" ne $rollid) {
			# Skip the rest of this segment
			while(<DUMPLFS>) {
				last if m/SEGMENT/;
			}
			# Fall through
		}
	}
	if (m/roll_id.*serial *([0-9]*)/) {
		$serno = $1;
		$snloc{$serno} = $segnum;
		$sumloc{$serno} = $sumloc;
		# print "serno $serno\n";
		if ($serno < $sstart) {
			# Skip the rest of this partial segment
			while(<DUMPLFS>) {
				last if m/Segment Summary/ ||
					m/SEGMENT/;
			}
			# Fall through
		}
	}
	if (m/Segment Summary Info at 0x([0-9a-f]*)/) {
		$sumloc = $1;
	}
	if (m/0x([0-9a-f]*)/) {
		foreach $ss (split "0x", $_) {
			if ($ss =~ m/^([0-9a-f][0-9a-f]*)/) {
				# print "iblk 0x$1\n";
				$daddr = $1;
				if (m/[^0-9]1v1/) {
					# print "** ifblk 0x$daddr\n";
					$iloc{$serno} = $daddr;
					$lastaddr = $daddr;
				}
			}
		}
	}
	if (m/SEGMENT *([0-9]*)/) {
		$segnum = $1;
		print " $segnum";
	}
}
print "\n";
close(DUMPLFS);

# If there were no checkpoints, print *something*
if ($#iloc == 0) {
	print "0 $sstart 0\n";
	exit 0;
}

#
# Now fsck each checkpoint in turn, beginning with $sstart.
# Because the log wraps we will have to reconstruct the filesystem image
# as it existed at each checkpoint before running fsck.
#
# Look for lines containing only caps or "!", but ignore known
# false positives.
#
$error = 0;
$lastgood = $sstart - 1;
open(LOG, ">>check-all.log");
print "Available checkpoints:";
print LOG "Available checkpoints:";
foreach $k (sort { $a <=> $b } keys %iloc) {
	$a = $iloc{$k};
	print " $a";
	print LOG " $a";
}
print "\n";
print LOG "\n";

print "Recreating filesystem image as of $sstart:\n";
if ($sstart == 0) {
	$cmd = "dd if=$rdev of=$wfile bs=1m conv=swab,oldebcdic"; # garbage
} else {
	$cmd = "dd if=$gfile of=$wfile bs=1m";
}
print "$cmd\n";
system("$cmd >/dev/null 2>&1");

$blstart = 0;
$fps = $ssize / $fsize;
foreach $k (sort { $a <=> $b } keys %iloc) {
	$a = $iloc{$k};

	if (hex($a) > hex($lastaddr)) {
		print "Skipping out-of-place checkpoint $k at $a\n";
		next;
	}

	# Copy the balance of the "new" fs image over the old one.
	$blstop = int ((hex $a) / $fps) + 1;
	$blstop *= $fps;
	if ($blstop != $blstart) {
		$cmd = "dd if=$rdev of=$wfile bs=$fsize seek=$blstart " .
			"skip=$blstart conv=notrunc";
		if ($blstop) {
			$cmd .= " count=" . ($blstop - $blstart);
		}
		$blstart = $blstop;
		print "$cmd\n";
		system("$cmd >/dev/null 2>&1");
	}

	$cmd = "fsck_lfs -n -f -i 0x$a $wfile";
	print "$cmd\n";
	print LOG "$cmd\n";
	open(FSCK, "$cmd 2>&1 |");
	while(<FSCK>) {
		print LOG;
		chomp;

		# Known false positives (mismatch between sb and ifile,
		# which should be expected given we're using an arbitrarily
		# old version fo the ifile)
		if (m/AVAIL GIVEN/ ||
		    m/BFREE GIVEN/ ||
		    m/DMETA GIVEN/ ||
		    m/NCLEAN GIVEN/ ||
		    m/FREE BUT NOT ON FREE LIST/ ||	# UNWRITTEN inodes OK
		    m/FREE LIST HEAD IN SUPERBLOCK/ ) {
			next;
		}

		# Fsck reports errors in ALL CAPS
		# But don't count hex numbers as "lowercase".
		s/0x[0-9a-f]*//g;
		if (m/[A-Z]/ && ! m/[a-z]/) {
			$error = 1;
			$errsn = $k;
			$errstr = "1 $k 0x$a";
			last;
		}
	}
	close(FSCK);
	last if $error;
	$lastgood = $k;	# record last good serial number
}
$errstr = "0 $lastgood 0x$a" unless $errstr;

if ($error == 0) {
	print "Copying this good image to $gfile\n";
	system("dd bs=1m if=$rdev of=$gfile >/dev/null 2>&1");
	print "$errstr\n";
	exit 0;
}

#
# If we found an error, try to find which blocks of the Ifile inode changed
# between the last good checkpoint and this checkpoint; and which blocks
# *should* have changed.  This means (1) which segments were written; and
# (2) which inodes were written.  The 0 block of the Ifile should always
# have changed since lfs_avail is always in flux.
#

$cmd = "dumplfs";
$oseg = -1;
%iblk = ();
%iblk_done = ();
%why = ();
$iblk{0} = 1;
for ($i = $lastgood + 1; $i <= $errsn; $i++) {
	if ($oseg != $snloc{$i}) {
		$oseg = 0 + $snloc{$i};
		$cmd .= " -s$oseg";
	}
}
$cmd .= " $rdev";

open(DUMPLFS, "$cmd |");
while(<DUMPLFS>) {
	if (m/ifpb *([0-9]*)/) {
		$ifpb = $1;
	}
	if (m/sepb *([0-9]*)/) {
		$sepb = $1;
	}
	if (m/cleansz *([0-9]*)/) {
		$cleansz = $1;
	}
	if (m/segtabsz *([0-9]*)/) {
		$segtabsz = $1;
	}
	last if m/SEGMENT/;
}
while(<DUMPLFS>) {
	chomp;

	# Skip over partial segments outside our range of interest
	if (m/roll_id.*serial *([0-9]*)/) {
		$serno = $1;
		if ($serno <= $lastgood || $serno > $errsn) {
			# Skip the rest of this partial segment
			while(<DUMPLFS>) {
				last if m/Segment Summary/ || m/SEGMENT/;
			}
			next;
		}
	}

	# Look for inodes
	if (m/Inode addresses/) {
		s/^[^{]*{/ /o;
		s/}[^{]*$/ /o;
		s/}[^{]*{/,/og;
		s/v[0-9]*//og;
		@ilist = split(',');
		foreach $i (@ilist) {
			$i =~ s/ *//og;
			next if $i == 1;
			$iaddr = $cleansz + $segtabsz + int ($i / $ifpb);
			$iblk{$iaddr} = 1;
			$why{$iaddr} .= " $i";
		}
	}

	# Look for Ifile blocks actually written
	if (m/FINFO for inode: ([0-9]*) version/) {
		$i = $1;
		$inoblkmode = ($i == 1);
	}
	if ($inoblkmode && m/^[-\t 0-9]*$/) {
		s/\t/ /og;
		s/^ *//o;
		s/ *$//o;
		@bn = split(' ');
		foreach $b (@bn) {
			$iblk_done{$b} = 1;
		}
	}
}
close(DUMPLFS);

# Report found and missing Ifile blocks
print "Ifile blocks found:";
foreach $b (sort { $a <=> $b } keys %iblk) {
	if ($iblk_done{$b} == 1) {
		print " $b";
	}
}
print "\n";

print "Ifile blocks missing:";
foreach $b (sort { $a <=> $b } keys %iblk) {
	if ($iblk_done{$b} == 0) {
		$why{$b} =~ s/^ *//o;
		print " $b ($why{$b})";
	}
}
print "\n";

print "$errstr\n";
exit 0;