[gparted] Explicitly read the reiser4 volume UUID when present

[Curtis Gedak <gedakc src gnome org>]

commit 690fedfff999ae17b2b63350ed0617c055982014
Author: Mike Fleetwood <mike fleetwood googlemail com>
Date:   Sat Mar 20 16:01:26 2021 +0000

    Explicitly read the reiser4 volume UUID when present
    
    Reiser4 has introduced new disk format which includes support for
    spanning the file system over multiple block devices (subvolumes)
    [1][2].  As such the output of the debugfs.reiser4 for the UUID has
    changed slightly.  So far the new reiser4progs package (version 2.0.x)
    is only available as a Debian experimental package.
    
    Using reiser4progs 1.2.1 the old output was like this:
    
        $ debugfs.reiser4 test.img
        debugfs.reiser4 1.2.1
        Format release: 4.0.2
        Copyright (C) 2001-2005 by Hans Reiser, licensing governed by reiser4progs/COPYING.
    
        Master super block (16):
        magic:          ReIsEr4
        blksize:        4096
        format:         0x0 (format40)
        uuid:           1116afce-99fd-4a6e-94cb-2d9f19c91d67
        label:          <none>
    
        ...
    
    With reiser4progs 2.0.4 the new output is like this:
    
        $ debugfs.reiser4 test.img
        debugfs.reiser4
        Package Version: 2.0.4
        Software Framework Release: 5.1.3
        Copyright (C) 2001-2005 by Hans Reiser, licensing governed by reiser4progs/COPYING.
        Master super block (16):
        magic:          ReIsEr4
        blksize:        4096
        volume:         0x1 (asym)
        distrib:        0x1 (fsx32m)
        format:         0x1 (format41)
        description:    Standard layout for logical volumes.
        stripe bits:    14
        mirror id:      0
        replicas:       0
        volume uuid:    9538bfa3-5694-4abe-864c-edc288a9d801
        subvol uuid:    d841c692-2042-49e6-ac55-57e454691782
        label:          <none>
    
        ...
    
    GParted happens to read the correct UUID just because the first matching
    "uuid" string in the output is the volume UUID.  Make the code more
    robust by explicitly reading the volume uuid when labelled as such.
    
    [1] Logical Volumes Howto
        https://reiser4.wiki.kernel.org/index.php/Logical_Volumes_Howto
    [2] Logical Volumes Background
        https://reiser4.wiki.kernel.org/index.php/Logical_Volumes_Background

 src/reiser4.cc | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)
---
diff --git a/src/reiser4.cc b/src/reiser4.cc
index ed4e1c6c..47f2c2d5 100644
--- a/src/reiser4.cc
+++ b/src/reiser4.cc
@@ -141,7 +141,12 @@ void reiser4::read_uuid( Partition & partition )
                return;
        }
 
-       partition.uuid = Utils::regexp_label(output, "uuid:[[:blank:]]*(" RFC4122_NONE_NIL_UUID_REGEXP ")");
+       Glib::ustring pattern = "uuid:[[:blank:]]*(" RFC4122_NONE_NIL_UUID_REGEXP ")";
+       // Reiser4progs >= 2.0.3 supports subvolumes.  Ensure the volume UUID, rather than
+       // subvolume UUID, is reported.
+       if (output.find("volume uuid:") != Glib::ustring::npos)
+               pattern = "volume " + pattern;
+       partition.uuid = Utils::regexp_label(output, pattern);
 }