[gparted] Use e2image to move/copy ext[234] file systems (#721516)

[Mike Fleetwood <mfleetwo src gnome org>]

commit 86111fe12a26d23d9fc2a9e2d19281290ecaf985
Author: Phillip Susi <psusi ubuntu com>
Date:   Sun Jan 5 00:32:54 2014 -0500

    Use e2image to move/copy ext[234] file systems (#721516)
    
    Use e2image features added in e2fsprogs 1.42.9 to move/copy
    an ext[234] file system more efficiently by skipping unused blocks.
    Fall back to the internal copy algorithm if e2image is not found
    or does not support move/copy.
    
    Bug #721516 - Use e2image to move/copy ext[234] filesystems

 include/ext2.h |    6 ++++++
 src/ext2.cc    |   39 ++++++++++++++++++++++++++++++++++++---
 2 files changed, 42 insertions(+), 3 deletions(-)
---
diff --git a/include/ext2.h b/include/ext2.h
index b9c7af4..778720a 100644
--- a/include/ext2.h
+++ b/include/ext2.h
@@ -38,6 +38,12 @@ public:
        bool create( const Partition & new_partition, OperationDetail & operationdetail ) ;
        bool resize( const Partition & partition_new, OperationDetail & operationdetail, bool fill_partition 
= false ) ;
        bool check_repair( const Partition & partition, OperationDetail & operationdetail ) ;
+       bool move( const Partition & partition_new,
+                  const Partition & partition_old,
+                  OperationDetail & operationdetail );
+       bool copy( const Partition & partition_new,
+                  Partition & partition_old,
+                  OperationDetail & operationdetail );
 };
 
 } //GParted
diff --git a/src/ext2.cc b/src/ext2.cc
index c77d49a..505bcb3 100644
--- a/src/ext2.cc
+++ b/src/ext2.cc
@@ -60,8 +60,18 @@ FS ext2::get_filesystem_support()
 
                if ( fs .check )
                {
-                       fs .copy = FS::GPARTED ;
-                       fs .move = FS::GPARTED ;
+                       fs.copy = fs.move = FS::GPARTED ;
+
+                       //If supported, use e2image to copy/move the file system as it
+                       //  only copies used blocks, skipping unused blocks.  This is more
+                       //  efficient than copying all blocks used by GParted's internal
+                       //  method.
+                       if ( ! Glib::find_program_in_path( "e2image" ) .empty() )
+                       {
+                               Utils::execute_command( "e2image", output, error, true ) ;
+                               if ( Utils::regexp_label( error, "(-o src_offset)" ) == "-o src_offset" )
+                                       fs.copy = fs.move = FS::EXTERNAL ;
+                       }
                }
 
                fs .online_read = FS::EXTERNAL ;
@@ -205,6 +215,29 @@ bool ext2::check_repair( const Partition & partition, OperationDetail & operatio
        return ( exit_status == 0 || exit_status == 1 || exit_status == 2 || exit_status == 256 ) ;
 }
 
-} //GParted
+bool ext2::move( const Partition & partition_new,
+                 const Partition & partition_old,
+                 OperationDetail & operationdetail )
+{
+       Sector distance;
+       Glib::ustring offset;
+       distance = partition_old.sector_start - partition_new.sector_start;
+       offset = Utils::num_to_str( llabs(distance) * partition_new.sector_size );
+       if ( distance < 0 )
+               return ! execute_command( "e2image -ra -p -o " + offset + " " + partition_new.get_path(),
+                                         operationdetail, true, true );
+       else
+               return ! execute_command( "e2image -ra -p -O " + offset + " " + partition_new.get_path(),
+                                         operationdetail, true, true );
 
+}
 
+bool ext2::copy( const Partition & src_part,
+                 Partition & dest_part,
+                 OperationDetail & operationdetail )
+{
+       return ! execute_command( "e2image -ra -p " + src_part.get_path() + " " + dest_part.get_path(),
+                                 operationdetail, true, true );
+}
+
+} //GParted