Matthew Booth
2010-Oct-12  13:05 UTC
[Libguestfs] [PATCH] Fix device name mapping for libata guests
remap_block_devices was modifying the global device list while remapping device
names for libata guests (which includes RHEL 6). This caused a failure later
when the renamed devices were not present in the original XML.
Fixes RHBZ#641869
---
 lib/Sys/VirtV2V/GuestOS/RedHat.pm |   14 +++++++++++++-
 1 files changed, 13 insertions(+), 1 deletions(-)
diff --git a/lib/Sys/VirtV2V/GuestOS/RedHat.pm
b/lib/Sys/VirtV2V/GuestOS/RedHat.pm
index a322a5d..cc95fd8 100644
--- a/lib/Sys/VirtV2V/GuestOS/RedHat.pm
+++ b/lib/Sys/VirtV2V/GuestOS/RedHat.pm
@@ -1567,7 +1567,19 @@ sub remap_block_devices
                 $letter++;
             }
 
-            map { $_ = $map{$_} } @$devices;
+            # N.B. Don't use map() here because we mustn't modify the
original
+            # devices list
+            my @newdevices;
+            foreach my $device (@$devices) {
+                my $map = $map{$device};
+
+                unless (defined($map)) {
+                    warn ("No mapping for device $device");
+                    next;
+                }
+                push(@newdevices, $map);
+            }
+            $devices = \@newdevices;
         }
     }
 
-- 
1.7.2.3
Daniel P. Berrange
2010-Oct-12  13:08 UTC
[Libguestfs] [PATCH] Fix device name mapping for libata guests
On Tue, Oct 12, 2010 at 02:05:25PM +0100, Matthew Booth wrote:> remap_block_devices was modifying the global device list while remapping device > names for libata guests (which includes RHEL 6). This caused a failure later > when the renamed devices were not present in the original XML. > > Fixes RHBZ#641869 > --- > lib/Sys/VirtV2V/GuestOS/RedHat.pm | 14 +++++++++++++- > 1 files changed, 13 insertions(+), 1 deletions(-) > > diff --git a/lib/Sys/VirtV2V/GuestOS/RedHat.pm b/lib/Sys/VirtV2V/GuestOS/RedHat.pm > index a322a5d..cc95fd8 100644 > --- a/lib/Sys/VirtV2V/GuestOS/RedHat.pm > +++ b/lib/Sys/VirtV2V/GuestOS/RedHat.pm > @@ -1567,7 +1567,19 @@ sub remap_block_devices > $letter++; > } > > - map { $_ = $map{$_} } @$devices; > + # N.B. Don't use map() here because we mustn't modify the original > + # devices listThe problem isn't that you used map(), it is that your map code block has side effects. You should be able to avoid the side effect thus: my @newdevices = map { $map{$_} } @$devices;> + my @newdevices; > + foreach my $device (@$devices) { > + my $map = $map{$device}; > + > + unless (defined($map)) { > + warn ("No mapping for device $device"); > + next; > + } > + push(@newdevices, $map); > + } > + $devices = \@newdevices; > }Regards, Daniel -- |: Red Hat, Engineering, London -o- http://people.redhat.com/berrange/ :| |: http://libvirt.org -o- http://virt-manager.org -o- http://deltacloud.org :| |: http://autobuild.org -o- http://search.cpan.org/~danberr/ :| |: GnuPG: 7D3B9505 -o- F3C9 553F A1DA 4AC2 5648 23C1 B3DF F742 7D3B 9505 :|