extrahd.cgi: Add support for LVM and MDADM devices

This commit adds support for using LVM and mdadm based RAID devices
for the CGI page.

In case one or more drives/partitions are used by such a "grouped"
volume they still will displayed on the page, but can not be
configured/used. Instead the "master" volume of which the
drive/partition is part of is shown in the "mountpoint" input box.

Signed-off-by: Stefan Schantl <stefan.schantl@ipfire.org>
Signed-off-by: Michael Tremer <michael.tremer@ipfire.org>

html/cgi-bin/extrahd.cgi

@@ -51,6 +51,12 @@ my @devices = &get_block_devices();
 # Grab all known UUID's.
 my %uuids = &get_uuids();
 
+# Detect device mapper devices.
+my %device_mapper = &get_device_mapper();
+
+# Grab members of group devices (RAID, LVM)
+my %grouped_devices = &collect_grouped_devices();
+
 # Grab all mountpoints.
 my %mountpoints = &get_mountpoints();
 
@@ -236,7 +242,39 @@ END
 		# Grab the known partitions of the current block device.
 		my @partitions = &get_device_partitions($device);
 
+		# Check if the block device has any partitions for display.
+		if (@partitions) {
+			# Loop through the partitions.
 			foreach my $partition (@partitions) {
+				# Call function to display the row in the WUI.
+				&print_row($partition);
+			}
+		}
+
+		# Also print rows for devices with an UUID.
+		&print_row($device) if($uuids{$device});
+	}
+
+        print <<END
+        <tr><td align="center" colspan="5">&nbsp;</td></tr>
+        <tr><td align="center" colspan="5">&nbsp;</td></tr>
+        <tr><td align="center" colspan="5">$Lang::tr{'extrahd install or load driver'}</td></tr>
+        </table>
+END
+;
+
+&Header::closebox();
+
+&Header::closebigbox();
+&Header::closepage();
+
+
+#
+# Function to print a table row with device data on the WUI.
+#
+sub print_row ($) {
+	my ($partition) = @_;
+
 	my $disabled;
 
 	# Omit the partition size.
@@ -251,6 +289,18 @@ END
 	# Get the mountpoint.
 	my $mountpoint = $mountpoints{$partition};
 
+	# Generate partition string.
+	my $partition_string = "/dev/$partition";
+
+	# Check if the given partition is managed by device mapper.
+	if (exists($device_mapper{$partition})) {
+		# Alter the partition string to used one by the device mapper.
+		$partition_string = "$device_mapper{$partition}";
+	}
+
+	# Check if the device is part of a group.
+	my $grouped_device = &is_grouped_member($partition);
+
 	# If no mountpoint could be determined try to grab from
 	# configured drives.
 	unless($mountpoint) {
@@ -276,19 +326,30 @@ END
 		$disabled = "disabled";
 		$mountpoint = "swap";
 		$fs = "swap";
+
+	# Check if the device is part of a group.
+	} elsif ($grouped_device) {
+		$disabled = "disabled";
+		$mountpoint = "/dev/$grouped_device";
+		$mountpoint = $device_mapper{$grouped_device} if (exists($device_mapper{$grouped_device}));
+	}
+
+	print "<form method='post' action='$ENV{'SCRIPT_NAME'}'>\n";
+
+	# Only display UUID details if an UUID could be obtained.
+	if ( $uuids{$partition} ) {
+		print "<tr><td align='left' colspan=5><strong>UUID=$uuids{$partition}</strong></td></tr>\n";
 	}
 
 	print <<END
 
-			<form method='post' action='$ENV{'SCRIPT_NAME'}'>
-			<tr><td align="left" colspan=5><strong>UUID=$uuids{$partition}</strong></td></tr>
 	<tr>
-			<td align="list">/dev/$partition</td>
+	<td align="list">$partition_string</td>
 		<td align="center">$Lang::tr{'size'} $size</td>
 		<td align="center">$fs</td>
 		<td align="center"><input type='text' name='PATH' value='$mountpoint' $disabled></td>
 		<td align="center">
-					<input type='hidden' name='DEVICE' value='/dev/$partition' />
+			<input type='hidden' name='DEVICE' value='$partition_string' />
 			<input type='hidden' name='UUID' value='$uuids{$partition}' />
 END
 ;
@@ -317,21 +378,8 @@ END
 	print <<END
 	</form></td></tr>
 END
-;		}
-
-	}
-
-	print <<END
-	<tr><td align="center" colspan="5">&nbsp;</td></tr>
-	<tr><td align="center" colspan="5">&nbsp;</td></tr>
-	<tr><td align="center" colspan="5">$Lang::tr{'extrahd install or load driver'}</td></tr>
-	</table>
-END
 ;
-&Header::closebox();
-
-&Header::closebigbox();
-&Header::closepage();
+}
 
 #
 ## Function which return an array with all available block devices.
@@ -486,6 +534,86 @@ sub get_device_size ($) {
 	return $size;
 }
 
+#
+## Function which tries to detect if a block device is a device mapper device and returns the alias a
+## a hash. Example: "dm-0" -> "/dev/mapper/GROUP-DEVICE"
+#
+sub get_device_mapper () {
+	my %mapper_devices = ();
+
+	# Loop through all known block devices.
+	foreach my $block_device (@devices) {
+		# Generate  device directory.
+		my $device_dir = "$sysfs_block_dir/$block_device";
+
+		# Skip the device if it is not managed by device mapper
+		# In this case the "bd" is not present.
+		next unless (-e "$device_dir/dm");
+
+		# Grab the group and volume name.
+		open(NAME, "$device_dir/dm/name") if (-e "$device_dir/dm/name");
+		my $name = <NAME>;
+		close(NAME);
+
+		# Skip device if no name could be determined.
+		next unless($name);
+
+		# Remove any newlines from the name string.
+		chomp($name);
+
+		# Generate path to the dev node in devfs.
+		my $dev_path = "/dev/mapper/$name";
+
+		# Store the device and the omited mapper name in the hash.
+		$mapper_devices{$block_device} = $dev_path;
+	}
+
+	# Return the hash of omited device mapper devices.
+	return %mapper_devices;
+}
+
+#
+## Function which will collect grouped devices and their members as array in a hash and returns them.
+## For example: "sda1" -> "dm-0" in case /dev/sda1 is assigned to a device mapper group.
+#
+sub collect_grouped_devices () {
+	my %grouped_devices = ();
+
+	# Loop through the array of known block devices.
+	foreach my $device (@devices) {
+		# Generate device directory.
+		my $device_dir = "$sysfs_block_dir/$device";
+
+		# Skip device if it has no members.
+		# In this case the "slaves" directory does not exist.
+		next unless (-e "$device_dir/slaves");
+
+		# Tempoarary array to store the members of a group.
+		my @members = ();
+
+		# Grab all members.
+		opendir(MEMBERS, "$device_dir/slaves");
+		while(readdir(MEMBERS)) {
+			next if($_ eq ".");
+			next if($_ eq "..");
+
+			# Add the found member to the array of members.
+			push(@members, $_);
+		}
+
+		closedir(MEMBERS);
+
+		# Skip the device if no members could be grabbed.
+		next unless (@members);
+
+		# Add the array of found members as value to the hash of grouped devices.
+		$grouped_devices{$device} = [ @members ];
+	}
+
+	# Return the hash of found grouped devices and their members.
+	return %grouped_devices;
+}
+
 #
 ## Function which returns all currently mounted devices as a hash.
 ## example: "sda1" -> "/boot"
@@ -708,3 +836,22 @@ sub is_configured ($) {
 	       return 1 if($configured_drives{$uuid} eq "$path");
 	}
 }
+
+#
+## Retruns the device name of the grouped device,if a given device is a group member.
+#
+sub is_grouped_member ($) {
+	my ($device) = @_;
+
+	# Loop through the hash of found grouped devices.
+	foreach my $grouped_device(keys %grouped_devices) {
+		# The found members are stored as arrays.
+		my @members = @{ $grouped_devices{$grouped_device} };
+
+		# Loop through array of members and check if the given
+		# device is part of it.
+		foreach my $member (@members) {
+			return $grouped_device if ($member eq $device);
+		}
+	}
+}