[pve-devel] [RFC storage 3/16] volume_import: Use a new name when the the name to import with already exists

Fabian Grünbichler f.gruenbichler at proxmox.com
Wed Feb 5 11:49:55 CET 2020


On January 29, 2020 2:30 pm, Fabian Ebner wrote:
> The ID of the new volume is returned and pvesm import prints it. This is
> useful for migration, since the storage on the target might already contain
> unused/orphaned disks.

this is dangerous, and should be explicitly requested. (see patch #6)

as-is, this can lead to a repeated "allocate and fully replicate into 
new volume" cycle when replication meets an orphaned disk with clashing 
volid.

> 
> Signed-off-by: Fabian Ebner <f.ebner at proxmox.com>
> ---
> 
> Breaks the current migration in QEMU/LXC if there is a collision,
> since the code doesn't die anymore and the config is not updated
> with the new name, i.e. needs patches 1,5,12 and 13.
> 
>  PVE/CLI/pvesm.pm             | 13 ++++++++-----
>  PVE/Storage/LVMPlugin.pm     | 14 +++++++++-----
>  PVE/Storage/Plugin.pm        | 12 ++++++++----
>  PVE/Storage/ZFSPoolPlugin.pm | 10 ++++++----
>  4 files changed, 31 insertions(+), 18 deletions(-)
> 
> diff --git a/PVE/CLI/pvesm.pm b/PVE/CLI/pvesm.pm
> index 510faba..7d8547b 100755
> --- a/PVE/CLI/pvesm.pm
> +++ b/PVE/CLI/pvesm.pm
> @@ -299,7 +299,7 @@ __PACKAGE__->register_method ({
>  	    },
>  	},
>      },
> -    returns => { type => 'null' },
> +    returns => { type => 'string' },
>      code => sub {
>  	my ($param) = @_;
>  
> @@ -352,11 +352,11 @@ __PACKAGE__->register_method ({
>  	my $cfg = PVE::Storage::config();
>  	my $volume = $param->{volume};
>  	my $delete = $param->{'delete-snapshot'};
> -	PVE::Storage::volume_import($cfg, $infh, $volume, $param->{format},
> +	my $volid = PVE::Storage::volume_import($cfg, $infh, $volume, $param->{format},
>  	    $param->{base}, $param->{'with-snapshots'});
> -	PVE::Storage::volume_snapshot_delete($cfg, $volume, $delete)
> +	PVE::Storage::volume_snapshot_delete($cfg, $volid, $delete)
>  	    if defined($delete);
> -	return;
> +	return $volid;
>      }
>  });
>  
> @@ -777,7 +777,10 @@ our $cmddef = {
>      path => [ __PACKAGE__, 'path', ['volume']],
>      extractconfig => [__PACKAGE__, 'extractconfig', ['volume']],
>      export => [ __PACKAGE__, 'export', ['volume', 'format', 'filename']],
> -    import => [ __PACKAGE__, 'import', ['volume', 'format', 'filename']],
> +    import => [ __PACKAGE__, 'import', ['volume', 'format', 'filename'], {}, sub  {
> +	my $volid = shift;
> +	print "successfully imported '$volid'\n";
> +    }],
>  };
>  
>  1;
> diff --git a/PVE/Storage/LVMPlugin.pm b/PVE/Storage/LVMPlugin.pm
> index f02c110..6c575f2 100644
> --- a/PVE/Storage/LVMPlugin.pm
> +++ b/PVE/Storage/LVMPlugin.pm
> @@ -638,17 +638,20 @@ sub volume_import {
>  
>      my $vg = $scfg->{vgname};
>      my $lvs = lvm_list_volumes($vg);
> -    die "volume $vg/$volname already exists\n"
> -	if $lvs->{$vg}->{$volname};
> +
> +    if ($lvs->{$vg}->{$volname}) {
> +	warn "volume $vg/$volname already exists - importing with a different name\n";
> +	$name = undef;
> +    }
>  
>      my ($size) = PVE::Storage::Plugin::read_common_header($fh);
>      $size = int($size/1024);
>  
>      eval {
>  	my $allocname = $class->alloc_image($storeid, $scfg, $vmid, 'raw', $name, $size);
> -	if ($allocname ne $volname) {
> -	    my $oldname = $volname;
> -	    $volname = $allocname; # Let the cleanup code know what to free
> +	my $oldname = $volname;
> +	$volname = $allocname;
> +	if (defined($name) && $allocname ne $oldname) {
>  	    die "internal error: unexpected allocated name: '$allocname' != '$oldname'\n";
>  	}
>  	my $file = $class->path($scfg, $volname, $storeid)
> @@ -661,6 +664,7 @@ sub volume_import {
>  	warn $@ if $@;
>  	die $err;
>      }
> +    return "$storeid:$volname";
>  }
>  
>  sub volume_import_write {
> diff --git a/PVE/Storage/Plugin.pm b/PVE/Storage/Plugin.pm
> index 0c39cbd..358a831 100644
> --- a/PVE/Storage/Plugin.pm
> +++ b/PVE/Storage/Plugin.pm
> @@ -1198,16 +1198,19 @@ sub volume_import {
>      # Check for an existing file first since interrupting alloc_image doesn't
>      # free it.
>      my $file = $class->path($scfg, $volname, $storeid);
> -    die "file '$file' already exists\n" if -e $file;
> +    if (-e $file) {
> +	warn "file '$file' already exists - importing with a different name\n";
> +	$name = undef;
> +    }
>  
>      my ($size) = read_common_header($fh);
>      $size = int($size/1024);
>  
>      eval {
>  	my $allocname = $class->alloc_image($storeid, $scfg, $vmid, $file_format, $name, $size);
> -	if ($allocname ne $volname) {
> -	    my $oldname = $volname;
> -	    $volname = $allocname; # Let the cleanup code know what to free
> +	my $oldname = $volname;
> +	$volname = $allocname;
> +	if (defined($name) && $allocname ne $oldname) {
>  	    die "internal error: unexpected allocated name: '$allocname' != '$oldname'\n";
>  	}
>  	my $file = $class->path($scfg, $volname, $storeid)
> @@ -1227,6 +1230,7 @@ sub volume_import {
>  	warn $@ if $@;
>  	die $err;
>      }
> +    return "$storeid:$volname";
>  }
>  
>  sub volume_import_formats {
> diff --git a/PVE/Storage/ZFSPoolPlugin.pm b/PVE/Storage/ZFSPoolPlugin.pm
> index d72ee16..6394692 100644
> --- a/PVE/Storage/ZFSPoolPlugin.pm
> +++ b/PVE/Storage/ZFSPoolPlugin.pm
> @@ -750,15 +750,17 @@ sub volume_import {
>      die "internal error: invalid file handle for volume_import\n"
>  	if !defined($fd);
>  
> -    my $dataset = ($class->parse_volname($volname))[1];
> +    my (undef, $dataset, $vmid) = $class->parse_volname($volname);
>      my $zfspath = "$scfg->{pool}/$dataset";
>      my $suffix = defined($base_snapshot) ? "\@$base_snapshot" : '';
>      my $exists = 0 == run_command(['zfs', 'get', '-H', 'name', $zfspath.$suffix],
>  			     noerr => 1, errfunc => sub {});
>      if (defined($base_snapshot)) {
>  	die "base snapshot '$zfspath\@$base_snapshot' doesn't exist\n" if !$exists;
> -    } else {
> -	die "volume '$zfspath' already exists\n" if $exists;
> +    } elsif ($exists) {
> +	warn "volume '$zfspath' already exists - importing with a different name\n";
> +	$dataset = $class->find_free_diskname($storeid, $scfg, $vmid, $format);
> +	$zfspath = "$scfg->{pool}/$dataset";
>      }
>  
>      eval { run_command(['zfs', 'recv', '-F', '--', $zfspath], input => "<&$fd") };
> @@ -771,7 +773,7 @@ sub volume_import {
>  	die $err;
>      }
>  
> -    return;
> +    return "$storeid:$dataset";
>  }
>  
>  sub volume_import_formats {
> -- 
> 2.20.1
> 
> 
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