[pve-devel] [PATCH storage v2 2/3] disks: die if storage name is already in use

[Aaron Lauterer]

If a storage of that type and name already exists (LVM, zpool, ...) but
we do not have a Proxmox VE Storage config for it, it is possible that
the creation will fail midway due to checks done by the underlying
storage layer itself. This in turn can lead to disks that are already
partitioned. Users would need to clean this up themselves.

By adding checks early on, not only checking against the PVE storage
config, but against the actual storage type itself, we can die early
enough, before we touch any disk.

For ZFS, the logic to gather pool data is moved into its own function to
be called from the index API endpoint and the check in the create
endpoint.

Signed-off-by: Aaron Lauterer <a.lauterer at proxmox.com>
---

changes since v1:
- moved zfs pool gathering from index api endpoint into its own function
to easily call it for the check as well
- zfs pool check is now using perl grep
- removed check if mounted path if a /dev one
- added check if a mount unit exists
    - moved definitions of $path, $mountunitname and $mountunitpath out
    of the worker

 PVE/API2/Disks/Directory.pm | 11 ++++--
 PVE/API2/Disks/LVM.pm       |  3 ++
 PVE/API2/Disks/LVMThin.pm   |  3 ++
 PVE/API2/Disks/ZFS.pm       | 77 +++++++++++++++++++++----------------
 4 files changed, 56 insertions(+), 38 deletions(-)

diff --git a/PVE/API2/Disks/Directory.pm b/PVE/API2/Disks/Directory.pm
index df63ba9..07190de 100644
--- a/PVE/API2/Disks/Directory.pm
+++ b/PVE/API2/Disks/Directory.pm
@@ -203,16 +203,19 @@ __PACKAGE__->register_method ({
 	my $dev = $param->{device};
 	my $node = $param->{node};
 	my $type = $param->{filesystem} // 'ext4';
+	my $path = "/mnt/pve/$name";
+	my $mountunitname = PVE::Systemd::escape_unit($path, 1) . ".mount";
+	my $mountunitpath = "/etc/systemd/system/$mountunitname";
 
 	$dev = PVE::Diskmanage::verify_blockdev_path($dev);
 	PVE::Diskmanage::assert_disk_unused($dev);
 	PVE::Storage::assert_sid_unused($name) if $param->{add_storage};
 
-	my $worker = sub {
-	    my $path = "/mnt/pve/$name";
-	    my $mountunitname = PVE::Systemd::escape_unit($path, 1) . ".mount";
-	    my $mountunitpath = "/etc/systemd/system/$mountunitname";
+	my $mounted = PVE::Diskmanage::mounted_paths();
+	die "a mountpoint for '${name}' already exists: ${path} ($1)\n" if $mounted->{$path};
+	die "a systemd mount unit already exists: ${mountunitpath}\n" if -e $mountunitpath;
 
+	my $worker = sub {
 	    PVE::Diskmanage::locked_disk_action(sub {
 		PVE::Diskmanage::assert_disk_unused($dev);
 
diff --git a/PVE/API2/Disks/LVM.pm b/PVE/API2/Disks/LVM.pm
index 6e4331a..a27afe2 100644
--- a/PVE/API2/Disks/LVM.pm
+++ b/PVE/API2/Disks/LVM.pm
@@ -152,6 +152,9 @@ __PACKAGE__->register_method ({
 	PVE::Diskmanage::assert_disk_unused($dev);
 	PVE::Storage::assert_sid_unused($name) if $param->{add_storage};
 
+	die "volume group with name '${name}' already exists\n"
+	    if PVE::Storage::LVMPlugin::lvm_vgs()->{$name};
+
 	my $worker = sub {
 	    PVE::Diskmanage::locked_disk_action(sub {
 		PVE::Diskmanage::assert_disk_unused($dev);
diff --git a/PVE/API2/Disks/LVMThin.pm b/PVE/API2/Disks/LVMThin.pm
index 58ecb37..690c183 100644
--- a/PVE/API2/Disks/LVMThin.pm
+++ b/PVE/API2/Disks/LVMThin.pm
@@ -110,6 +110,9 @@ __PACKAGE__->register_method ({
 	PVE::Diskmanage::assert_disk_unused($dev);
 	PVE::Storage::assert_sid_unused($name) if $param->{add_storage};
 
+	die "volume group with name '${name}' already exists\n"
+	    if PVE::Storage::LVMPlugin::lvm_vgs()->{$name};
+
 	my $worker = sub {
 	    PVE::Diskmanage::locked_disk_action(sub {
 		PVE::Diskmanage::assert_disk_unused($dev);
diff --git a/PVE/API2/Disks/ZFS.pm b/PVE/API2/Disks/ZFS.pm
index eeb9f48..51380c4 100644
--- a/PVE/API2/Disks/ZFS.pm
+++ b/PVE/API2/Disks/ZFS.pm
@@ -18,6 +18,43 @@ use base qw(PVE::RESTHandler);
 my $ZPOOL = '/sbin/zpool';
 my $ZFS = '/sbin/zfs';
 
+sub get_pool_data {
+    if (!-f $ZPOOL) {
+	die "zfsutils-linux not installed\n";
+    }
+
+    my $propnames = [qw(name size alloc free frag dedup health)];
+    my $numbers = {
+	size => 1,
+	alloc => 1,
+	free => 1,
+	frag => 1,
+	dedup => 1,
+    };
+
+    my $cmd = [$ZPOOL,'list', '-HpPLo', join(',', @$propnames)];
+
+    my $pools = [];
+
+    run_command($cmd, outfunc => sub {
+	my ($line) = @_;
+
+	    my @props = split('\s+', trim($line));
+	    my $pool = {};
+	    for (my $i = 0; $i < scalar(@$propnames); $i++) {
+		if ($numbers->{$propnames->[$i]}) {
+		    $pool->{$propnames->[$i]} = $props[$i] + 0;
+		} else {
+		    $pool->{$propnames->[$i]} = $props[$i];
+		}
+	    }
+
+	    push @$pools, $pool;
+    });
+
+    return $pools;
+}
+
 __PACKAGE__->register_method ({
     name => 'index',
     path => '',
@@ -74,40 +111,7 @@ __PACKAGE__->register_method ({
     code => sub {
 	my ($param) = @_;
 
-	if (!-f $ZPOOL) {
-	    die "zfsutils-linux not installed\n";
-	}
-
-	my $propnames = [qw(name size alloc free frag dedup health)];
-	my $numbers = {
-	    size => 1,
-	    alloc => 1,
-	    free => 1,
-	    frag => 1,
-	    dedup => 1,
-	};
-
-	my $cmd = [$ZPOOL,'list', '-HpPLo', join(',', @$propnames)];
-
-	my $pools = [];
-
-	run_command($cmd, outfunc => sub {
-	    my ($line) = @_;
-
-		my @props = split('\s+', trim($line));
-		my $pool = {};
-		for (my $i = 0; $i < scalar(@$propnames); $i++) {
-		    if ($numbers->{$propnames->[$i]}) {
-			$pool->{$propnames->[$i]} = $props[$i] + 0;
-		    } else {
-			$pool->{$propnames->[$i]} = $props[$i];
-		    }
-		}
-
-		push @$pools, $pool;
-	});
-
-	return $pools;
+	return get_pool_data();
     }});
 
 sub preparetree {
@@ -336,6 +340,7 @@ __PACKAGE__->register_method ({
 	my $user = $rpcenv->get_user();
 
 	my $name = $param->{name};
+	my $node = $param->{node};
 	my $devs = [PVE::Tools::split_list($param->{devices})];
 	my $raidlevel = $param->{raidlevel};
 	my $compression = $param->{compression} // 'on';
@@ -346,6 +351,10 @@ __PACKAGE__->register_method ({
 	}
 	PVE::Storage::assert_sid_unused($name) if $param->{add_storage};
 
+	my $pools = get_pool_data();
+	die "pool '${name}' already exists on node '$node'\n"
+	    if grep { $_->{name} eq $name } @{$pools};
+
 	my $numdisks = scalar(@$devs);
 	my $mindisks = {
 	    single => 1,
-- 
2.30.2