move loopback.pm to fs/loopback.pm

(since it's tightly tight to many fs* things)

1 files changed, 125 insertions, 0 deletions

diff --git a/perl-install/fs/loopback.pm b/perl-install/fs/loopback.pm
new file mode 100644
index 000000000..a7c6c913d
--- /dev/null
+++ b/perl-install/fs/loopback.pm
@@ -0,0 +1,125 @@
+package fs::loopback; # $Id$
+
+use diagnostics;
+use strict;
+
+#-######################################################################################
+#- misc imports
+#-######################################################################################
+use common;
+use fs::type;
+use fs;
+use log;
+
+
+sub carryRootLoopback {
+    my ($part) = @_;
+    $_->{mntpoint} eq '/' and return 1 foreach @{$part->{loopback} || []};
+    0;
+}
+
+sub check_circular_mounts {
+    my ($part, $all_hds) = @_;
+
+    my $fstab = [ fs::get::fstab($all_hds), $part ]; # no pb if $part is already in $all_hds
+
+    my $base_mntpoint = $part->{mntpoint};
+    my $check; $check = sub {
+	my ($part, @seen) = @_;
+	push @seen, $part->{mntpoint} || return;
+	@seen > 1 && $part->{mntpoint} eq $base_mntpoint and die N("Circular mounts %s\n", join(", ", @seen));
+	if (my $part = fs::get::up_mount_point($part->{mntpoint}, $fstab)) {
+	    #- '/' carrier is a special case, it will be mounted first
+	    $check->($part, @seen) if !carryRootLoopback($part);
+	}
+	if (isLoopback($part)) {
+	    $check->($part->{loopback_device}, @seen);
+	}
+    };
+    $check->($part) if !($base_mntpoint eq '/' && isLoopback($part)); #- '/' is a special case, no loop check
+}
+
+sub carryRootCreateSymlink {
+    my ($part, $prefix) = @_;
+
+    carryRootLoopback($part) or return;
+
+    my $mntpoint = "$prefix$part->{mntpoint}";
+    unless (-e $mntpoint) {
+	eval { mkdir_p(dirname($mntpoint)) };
+	#- do non-relative link for install, should be changed to relative link before rebooting
+	symlink "/initrd/loopfs", $mntpoint;
+
+	mkdir_p("/initrd/loopfs/lnx4win/boot");
+	symlink "/initrd/loopfs/lnx4win/boot", "$prefix/boot";
+    }
+    #- indicate kernel to keep initrd
+    mkdir_p("$prefix/initrd");
+}
+
+
+sub format_part {
+    my ($part, $prefix) = @_;
+    fs::mount_part($part->{loopback_device}, $prefix);
+    create($part, $prefix);
+    fs::format::part_raw($part, undef);
+}
+
+sub create {
+    my ($part, $prefix) = @_;
+    my $f = $part->{device} = "$prefix$part->{loopback_device}{mntpoint}$part->{loopback_file}";
+    return if -e $f;
+
+    eval { mkdir_p(dirname($f)) };
+
+    log::l("creating loopback file $f ($part->{size} sectors)");
+
+    my $block_size = 128;
+    my $s = "\0" x (512 * $block_size);
+    sysopen(my $F, $f, 2 | c::O_CREAT()) or die "failed to create loopback file";
+    for (my $i = 0; $i < $part->{size}; $i += $block_size) {
+	syswrite $F, $s or die "failed to create loopback file";
+    }
+}
+
+sub getFree {
+    my ($dir, $part) = @_;
+    my $freespace = $dir ? 
+      2 * (MDK::Common::System::df($dir))[1] : #- df in KiB
+      $part->{size};
+
+    $freespace - sum map { $_->{size} } @{$part->{loopback} || []};
+}
+
+#- returns the size of the loopback file if it already exists
+#- returns -1 is the loopback file can not be used
+sub verifFile {
+    my ($dir, $file, $part) = @_;
+    -e "$dir$file" and return -s "$dir$file";
+
+    $_->{loopback_file} eq $file and return -1 foreach @{$part->{loopback} || []};
+
+    undef;
+}
+
+sub prepare_boot() {
+    my $r = readlink "$::prefix/boot"; 
+    unlink "$::prefix/boot"; 
+    mkdir_p("$::prefix/boot");
+    [$r, $::prefix];
+}
+
+sub save_boot {
+    my ($loop_boot, $prefix) = @{$_[0]};
+    
+    $loop_boot or return;
+
+    my @files = glob_("$prefix/boot/*");
+    cp_af(@files, $loop_boot) if @files;
+    rm_rf("$prefix/boot");
+    symlink $loop_boot, "$prefix/boot";
+}
+
+
+1;
+