diff options
Diffstat (limited to 'perl-install/partition_table/dos.pm')
| -rw-r--r-- | perl-install/partition_table/dos.pm | 305 |
1 files changed, 279 insertions, 26 deletions
diff --git a/perl-install/partition_table/dos.pm b/perl-install/partition_table/dos.pm index cb687e6b0..aa020131a 100644 --- a/perl-install/partition_table/dos.pm +++ b/perl-install/partition_table/dos.pm @@ -1,4 +1,4 @@ -package partition_table::dos; # $Id$ +package partition_table::dos; use diagnostics; use strict; @@ -6,56 +6,219 @@ use vars qw(@ISA); @ISA = qw(partition_table::raw); +use Time::HiRes qw(usleep); use common; use partition_table::raw; use partition_table; +use fs::proc_partitions; +use fs::type; use c; -my @fields = qw(active start_head start_sec start_cyl type end_head end_sec end_cyl start size); +=head1 SYNOPSYS + +Read/write MBR partition tables + +=head1 Functions + +=over + +=cut + +my @fields = qw(active start_head start_sec start_cyl pt_type end_head end_sec end_cyl start size); my $format = "C8 V2"; my $magic = "\x55\xAA"; my $nb_primary = 4; my $offset = $common::SECTORSIZE - length($magic) - $nb_primary * common::psizeof($format); +sub use_pt_type { 1 } sub hasExtended { 1 } +sub geometry_to_string { + my ($geom) = @_; + "$geom->{cylinders}/$geom->{heads}/$geom->{sectors}"; +} + sub last_usable_sector { my ($hd) = @_; - #- do not use totalsectors, see gi/docs/Partition-ends-after-end-of-disk.txt for more + #- do not use totalsectors, see docs/Partition-ends-after-end-of-disk.txt for more $hd->{geom}{sectors} * $hd->{geom}{heads} * $hd->{geom}{cylinders}; } -sub compute_CHS($$) { - my ($hd, $e) = @_; - my @l = qw(cyl head sec); - @$e{map { "start_$_" } @l} = $e->{start} || $e->{type} ? CHS2rawCHS($hd, sector2CHS($hd, $e->{start})) : (0,0,0); - @$e{map { "end_$_" } @l} = $e->{start} || $e->{type} ? CHS2rawCHS($hd, sector2CHS($hd, $e->{start} + $e->{size} - 1)) : (0,0,0); - 1; +my $two_TB = 2 * 1024 * 1024 * 2048; +sub max_partition_start { $two_TB - 1 } +sub max_partition_size { $two_TB - 1 } + +sub get_rawCHS { + my ($part) = @_; + + exists $part->{start_cyl} or internal_error("get_rawCHS $part->{device}"); + + [ $part->{start_cyl}, $part->{start_head}, $part->{start_sec} ], + [ $part->{end_cyl}, $part->{end_head}, $part->{end_sec} ]; +} +sub set_rawCHS { + my ($part, $raw_chs_start, $raw_chs_end) = @_; + ($part->{start_cyl}, $part->{start_head}, $part->{start_sec}) = @$raw_chs_start; + ($part->{end_cyl}, $part->{end_head}, $part->{end_sec}) = @$raw_chs_end; +} + +sub compute_CHS { + my ($hd, $part) = @_; + my ($chs_start, $chs_end) = CHS_from_part_linear($hd->{geom}, $part); + set_rawCHS($part, $chs_start ? CHS2rawCHS($hd->{geom}, $chs_start) : [0,0,0], + $chs_end ? CHS2rawCHS($hd->{geom}, $chs_end) : [0,0,0]); +} + +sub CHS_from_part_rawCHS { + my ($part) = @_; + + $part->{start} || $part->{pt_type} or return; + + my ($raw_chs_start, $raw_chs_end) = get_rawCHS($part); + rawCHS2CHS($raw_chs_start), rawCHS2CHS($raw_chs_end); +} + +sub CHS_from_part_linear { + my ($geom, $part) = @_; + + $part->{start} || $part->{pt_type} or return; + + sector2CHS($geom, $part->{start}), sector2CHS($geom, $part->{start} + $part->{size} - 1); +} + +sub rawCHS2CHS { + my ($chs) = @_; + my ($c, $h, $s) = @$chs; + [ $c | (($s & 0xc0) << 2), $h, ($s & 0x3f) - 1 ]; } sub CHS2rawCHS { - my ($hd, $chs) = @_; + my ($geom, $chs) = @_; my ($c, $h, $s) = @$chs; if ($c > 1023) { #- no way to have a #cylinder >= 1024 $c = 1023; - $h = $hd->{geom}{heads} - 1; - $s = $hd->{geom}{sectors}; + $h = $geom->{heads} - 1; + $s = $geom->{sectors} - 1; } - ($c & 0xff, $h, $s | (($c >> 2) & 0xc0)); + [ $c & 0xff, $h, ($s + 1) | (($c >> 2) & 0xc0) ]; } -# returns (cylinder, head, sector) +=item sector2CHS($geom, $start) + +returns (cylinder, head, sector) + +=cut + sub sector2CHS { - my ($hd, $start) = @_; + my ($geom, $start) = @_; my ($s, $h); - ($start, $s) = divide($start, $hd->{geom}{sectors}); - ($start, $h) = divide($start, $hd->{geom}{heads}); - [ $start, $h, $s + 1 ]; + ($start, $s) = divide($start, $geom->{sectors}); + ($start, $h) = divide($start, $geom->{heads}); + [ $start, $h, $s ]; +} + +sub is_geometry_valid_for_the_partition_table { + my ($hd, $geom, $no_log) = @_; + + every { + my ($chs_start_v1, $chs_end_v1) = map { join(',', @$_) } CHS_from_part_rawCHS($_) or next; + my ($chs_start_v2, $chs_end_v2) = map { join(',', @$_) } map { [ min($_->[0], 1023), $_->[1], $_->[2] ] } CHS_from_part_linear($geom, $_); + if (!$no_log) { + $chs_start_v1 eq $chs_start_v2 or log::l("is_geometry_valid_for_the_partition_table failed for ($_->{device}, $_->{start}): $chs_start_v1 vs $chs_start_v2 with geometry " . geometry_to_string($geom)); + $chs_end_v1 eq $chs_end_v2 or log::l("is_geometry_valid_for_the_partition_table failed for ($_->{device}, " . ($_->{start} + $_->{size} - 1) . "): $chs_end_v1 vs $chs_end_v2 with geometry " . geometry_to_string($geom)); + } + $chs_start_v1 eq $chs_start_v2 && $chs_end_v1 eq $chs_end_v2; + } @{$hd->{primary}{normal} || []}; +} + +#- from parted, thanks! +my @valid_nb_sectors = (63, 61, 48, 32, 16); +my @valid_nb_heads = (255, 240, 192, 128, 96, 64, 61, 32, 17, 16); + +sub guess_geometry_from_partition_table { + my ($hd) = @_; + + my @chss = map { CHS_from_part_rawCHS($_) } @{$hd->{primary}{normal} || []} or return { empty => 1 }; + my ($nb_heads, $nb_sectors) = (max(map { $_->[1] } @chss) + 1, max(map { $_->[2] } @chss) + 1); + my $geom = { sectors => $nb_sectors, heads => $nb_heads }; + partition_table::raw::compute_nb_cylinders($geom, $hd->{totalsectors}); + log::l("guess_geometry_from_partition_table $hd->{device}: " . geometry_to_string($geom)); + + member($geom->{sectors}, @valid_nb_sectors) or return { invalid => 1 }; + $geom; } -sub read { +sub geometry_from_edd { + my ($hd, $edd_dir) = @_; + + my $sectors = cat_("$edd_dir/legacy_sectors_per_track") or return; + my $heads = cat_("$edd_dir/legacy_max_head") or return; + + my $geom = { sectors => 0 + $sectors, heads => 1 + $heads, from_edd => 1 }; + is_geometry_valid_for_the_partition_table($hd, $geom, 0) or return; + partition_table::raw::compute_nb_cylinders($geom, $hd->{totalsectors}); + + log::l("geometry_from_edd $hd->{device} $hd->{volume_id}: " . geometry_to_string($geom)); + + $geom; +} + + +sub try_every_geometry { + my ($hd) = @_; + + my $geom = {}; + foreach (@valid_nb_sectors) { + $geom->{sectors} = $_; + foreach (@valid_nb_heads) { + $geom->{heads} = $_; + if (is_geometry_valid_for_the_partition_table($hd, $geom, 1)) { + partition_table::raw::compute_nb_cylinders($geom, $hd->{totalsectors}); + log::l("try_every_geometry $hd->{device}: found " . geometry_to_string($geom)); + return $geom; + } + } + } + log::l("$hd->{device}: argh! no geometry exists for this partition table"); + undef; +} + +sub set_best_geometry_for_the_partition_table { + my ($hd) = @_; + + my $guessed_geom = guess_geometry_from_partition_table($hd); + if ($guessed_geom->{empty}) { + log::l("$hd->{device}: would need looking at BIOS info to find out geometry") if !$hd->{geom}{from_edd}; + return; + } + my $default_ok = is_geometry_valid_for_the_partition_table($hd, $hd->{geom}, 0); + if ($guessed_geom->{invalid}) { + log::l("$hd->{device}: no valid geometry guessed from partition table"); + $default_ok and return; + $guessed_geom = try_every_geometry($hd) or return; + } + + if ($guessed_geom->{heads} == $hd->{geom}{heads} && $guessed_geom->{sectors} == $hd->{geom}{sectors}) { + # cool! + } else { + my $guessed_ok = is_geometry_valid_for_the_partition_table($hd, $guessed_geom, 0); + if ($default_ok && $guessed_ok) { + #- oh my!? + log::l("$hd->{device}: both guessed and default are valid??? " . geometry_to_string($hd->{geom}) . " vs " . geometry_to_string($guessed_geom)); + } elsif ($default_ok) { + log::l("$hd->{device}: keeping default geometry " . geometry_to_string($hd->{geom})); + } elsif ($guessed_ok) { + log::l("$hd->{device}: using guessed geometry " . geometry_to_string($guessed_geom) . " instead of " . geometry_to_string($hd->{geom})); + put_in_hash($hd->{geom}, $guessed_geom); + } else { + log::l("$hd->{device}: argh! no valid geometry found"); + } + } +} + +sub read_one { my ($hd, $sector) = @_; my $tmp; @@ -64,7 +227,10 @@ sub read { my @pt = map { sysread $F, $tmp, psizeof($format) or die "error while reading partition table in sector $sector"; - my %h; @h{@fields} = unpack $format, $tmp; + my %h; + @h{@fields} = unpack $format, $tmp; + $h{pt_type} = 'BIOS_GRUB' if $h{pt_type} == 0 && $h{size} > 0; + fs::type::set_pt_type(\%h, $h{pt_type}); \%h; } (1..$nb_primary); @@ -72,13 +238,32 @@ sub read { sysread $F, $tmp, length $magic or die "error reading magic number on disk $hd->{device}"; $tmp eq $magic or die "bad magic number on disk $hd->{device}"; + if ($hd->{current_pt_table_type} ne "dos") { + # libparted may have ignored it because of overlapping partitions or other error + # while it is actually a partition table. + $hd->{fs_type_from_magic} and die "unpartitionned disk"; + my $primary = partition_table::raw::pt_info_to_primary($hd, [ @pt ]); + foreach my $i (@{$primary->{normal}}) { + if ($i->{active} && $i->{active} != 0x80 || + $hd->{totalsectors} && $i->{start} > $hd->{totalsectors}) { + die "Invalid DOS partition table"; + } + } + } + [ @pt ]; } -# write the partition table (and extended ones) -# for each entry, it uses fields: start, size, type, active -sub write($$$;$) { - my ($hd, $sector, $pt) = @_; +=item start_write($hd) + +Prepare to write the partition table (and extended ones) + +=cut + +sub start_write { + my ($hd) = @_; + + log::l("partition::dos::write $hd->{device}"); #- handle testing for writing partition table on file only! my $F; @@ -87,6 +272,27 @@ sub write($$$;$) { open $F, ">$file" or die "error opening test file $file"; } else { $F = partition_table::raw::openit($hd, 2) or die "error opening device $hd->{device} for writing"; + if ($hd->{was_hybrid_iso}) { + log::l("partition::dos::start_write erasing hybrid iso9660 signature"); + c::lseek_sector(fileno($F), 0, 0x8001) or return 0; + syswrite $F, "\0\0\0\0\0", 5 or return 0; + $hd->{was_hybrid_iso} = 0; + } + } + $F; +} + +=item start_write($hd, $F, $sector, $pt) + +Write the partition table (and extended ones). +For each entry, it uses fields: start, size, pt_type, active + +=cut + +sub write { + my ($hd, $F, $sector, $pt) = @_; + + if (!$::testing) { c::lseek_sector(fileno($F), $sector, $offset) or return 0; } @@ -94,13 +300,60 @@ sub write($$$;$) { foreach (@$pt) { compute_CHS($hd, $_); local $_->{start} = $_->{local_start} || 0; - $_->{active} ||= 0; $_->{type} ||= 0; $_->{size} ||= 0; #- for no warning + $_->{active} ||= 0; $_->{pt_type} ||= 0; $_->{size} ||= 0; #- for no warning syswrite $F, pack($format, @$_{@fields}), psizeof($format) or return 0; } syswrite $F, $magic, length $magic or return 0; 1; } -sub clear_raw { { raw => [ ({}) x $nb_primary ] } } +sub end_write { + my ($hd, $F) = @_; + close $F; +} + +sub need_to_tell_kernel { + my ($hd) = @_; + # Whenever udevd receives a change event for a raw disk device it is watching, it asks the kernel to + # rescan the partition table on that device by calling the BLKRRPART ioctl. This is only successful + # if none of the partitions on that device are currently mounted. So if any partitions are mounted, + # we need to tell the kernel what has changed ourselves. + # The udev/rules.d/60-block.rules file causes the raw disk devices to be watched by udev. This file is + # not present in the cut-down system used to run the classic installer, so we always need to tell the + # kernel in that case. + # diskdrake will not let the user delete an individual partition that is mounted, but will let the + # user clear all partitions. So initialize() records if any partitions were mounted and we take note + # of that here. + return 1 if ! -e '/usr/lib/udev/rules.d/60-block.rules' || delete $hd->{hadMountedPartitions} || any { $_->{isMounted} } partition_table::get_normal_parts($hd); + + # No further actions must be performed until the kernel has been informed of the changes. There is + # no easy way to check that udevd has received the uevent and called the BLKRRPART ioctl, so do it + # the hard way. + my $tries = 0; + do { + usleep(100000); + log::l("checking that udevd has informed the kernel of partition table changes"); + eval { fs::proc_partitions::compare($hd) }; + return 0 if !$@; + $tries++; + } while $tries < 5; + + # We don't expect to get here, but fail safe if so. + log::l("udevd failed to inform kernel of partition table changes"); + $hd->{rebootNeeded} = 1; + 1; +} + +sub empty_raw { { raw => [ ({}) x $nb_primary ] } } + +sub initialize { + my ($class, $hd) = @_; + # Remember whether any existing partitions are mounted, for use by need_to_tell_kernel(). + $hd->{hadMountedPartitions} = 1 if any { $_->{isMounted} } partition_table::get_normal_parts($hd); + # Remember whether this was a hybrid ISO so we can wipe the iso9660 signature. + $hd->{was_hybrid_iso} = 1 if $hd->{primary}{is_hybrid_iso}; + $hd->{primary} = empty_raw(); + bless $hd, $class; +} 1; |