diff options
Diffstat (limited to 'perl-install/resize_fat/any.pm')
-rw-r--r-- | perl-install/resize_fat/any.pm | 82 |
1 files changed, 82 insertions, 0 deletions
diff --git a/perl-install/resize_fat/any.pm b/perl-install/resize_fat/any.pm new file mode 100644 index 000000000..d78a342be --- /dev/null +++ b/perl-install/resize_fat/any.pm @@ -0,0 +1,82 @@ +package resize_fat::any; + +use diagnostics; +use strict; +use vars qw($FREE $FILE $DIRECTORY); + +use common qw(:common :constant); +use resize_fat::fat; +use resize_fat::directory; +use resize_fat::dir_entry; + + +$FREE = 0; +$FILE = 1; +$DIRECTORY = 2; + + +1; + + +# returns the number of clusters for a given filesystem type +sub min_cluster_count($) { + my ($fs) = @_; + (1 << $ {{ FAT16 => 12, FAT32 => 16 }}{$fs->{fs_type}}) - 12; +} +sub max_cluster_count($) { + my ($fs) = @_; + $resize_fat::bad_cluster_value - 2; +} + + + +# calculates the minimum size of a partition, in physical sectors +sub min_size($) { + my ($fs) = @_; + my $count = $fs->{clusters}->{count}; + + # directories are both in `used' and `dirs', so are counted twice + # It's done on purpose since we're moving all directories. So at the worse + # moment, 2 directories are there, but that way nothing wrong can happen :) + my $min_cluster_count = max(2 + $count->{used} + $count->{bad} + $count->{dirs}, min_cluster_count($fs)); + + $min_cluster_count * divide($fs->{cluster_size}, $SECTORSIZE) + + divide($fs->{cluster_offset}, $SECTORSIZE); +} +# calculates the maximum size of a partition, in physical sectors +sub max_size($) { + my ($fs) = @_; + + my $max_cluster_count = min($fs->{nb_fat_entries} - 2, max_cluster_count($fs)); + + $max_cluster_count * divide($fs->{cluster_size}, $SECTORSIZE) + + divide($fs->{cluster_offset}, $SECTORSIZE); +} + +# fills in $fs->{fat_flag_map}. +# Each FAT entry is flagged as either FREE, FILE or DIRECTORY. +sub flag_clusters { + my ($fs) = @_; + my ($cluster, $entry, $type); + + my $f = sub { + ($entry) = @_; + $cluster = resize_fat::dir_entry::get_cluster($entry); + + if (resize_fat::dir_entry::is_file($entry)) { + $type = $FILE; + } elsif (resize_fat::dir_entry::is_directory($entry)) { + $type = $DIRECTORY; + } else { return } + + for (; !resize_fat::fat::is_eof($cluster); $cluster = resize_fat::fat::next($fs, $cluster)) { + $cluster == 0 and die "Bad FAT: unterminated chain for $entry->{name}\n"; + $fs->{fat_flag_map}->[$cluster] and die "Bad FAT: cluster $cluster is cross-linked for $entry->{name}\n"; + $fs->{fat_flag_map}->[$cluster] = $type; + $fs->{clusters}->{count}->{dirs}++ if $type == $DIRECTORY; + } + }; + $fs->{fat_flag_map} = [ ($FREE) x ($fs->{nb_clusters} + 2) ]; + $fs->{clusters}->{count}->{dirs} = 0; + resize_fat::directory::traverse_all($fs, $f); +} |