fix #254: iscsi: add support for multipath targets

With this patch Proxmox now tries to login to all discovered portals
in case some of them are not logged yet.
In case of multipath configuration when initially configured portal is
missing for some reason Proxmox don't lose iSCSI storage now and can
successfully restore iSCSI connection between reboots.

Signed-off-by: Yuri Konotopov <ykonotopov@gnome.org>
Reviewed-By: Dominik Csapak <d.csapak@proxmox.com>
Tested-By: Dominik Csapak <d.csapak@proxmox.com>

diff --git a/src/PVE/Storage.pm b/src/PVE/Storage.pm
index 8ad493f897da719389688873c39ae126bc025e8e..0beabbcf060a179030606f1b32f3feb09bbb30da 100755 (executable)
--- a/src/PVE/Storage.pm
+++ b/src/PVE/Storage.pm
@@ -1445,7 +1445,7 @@ sub scan_iscsi {
        die "unable to parse/resolve portal address '${portal_in}'\n";
     }
 
-    return PVE::Storage::ISCSIPlugin::iscsi_discovery($portal);
+    return PVE::Storage::ISCSIPlugin::iscsi_discovery([ $portal ]);
 }
 
 sub storage_default_format {

diff --git a/src/PVE/Storage/ISCSIPlugin.pm b/src/PVE/Storage/ISCSIPlugin.pm
index a79fcb08c56df17e1570f732eec8986bd7751c0e..b4ab1dd09017722e2248ca6c01b78d26647810dc 100644 (file)
--- a/src/PVE/Storage/ISCSIPlugin.pm
+++ b/src/PVE/Storage/ISCSIPlugin.pm
@@ -18,6 +18,9 @@ use base qw(PVE::Storage::Plugin);
 my $ISCSIADM = '/usr/bin/iscsiadm';
 $ISCSIADM = undef if ! -X $ISCSIADM;
 
+# Example: 192.168.122.252:3260,1 iqn.2003-01.org.linux-iscsi.proxmox-nfs.x8664:sn.00567885ba8f
+my $ISCSI_TARGET_RE = qr/^((?:$IPV4RE|\[$IPV6RE\]):\d+)\,\S+\s+(\S+)\s*$/;
+
 sub check_iscsi_support {
     my $noerr = shift;
 
@@ -45,11 +48,12 @@ sub iscsi_session_list {
     eval {
        run_command($cmd, errmsg => 'iscsi session scan failed', outfunc => sub {
            my $line = shift;
-
-           if ($line =~ m/^tcp:\s+\[(\S+)\]\s+\S+\s+(\S+)(\s+\S+)?\s*$/) {
-               my ($session, $target) = ($1, $2);
+           # example: tcp: [1] 192.168.122.252:3260,1 iqn.2003-01.org.linux-iscsi.proxmox-nfs.x8664:sn.00567885ba8f (non-flash)
+           if ($line =~ m/^tcp:\s+\[(\S+)\]\s+((?:$IPV4RE|\[$IPV6RE\]):\d+)\,\S+\s+(\S+)\s+\S+?\s*$/) {
+               my ($session_id, $portal, $target) = ($1, $2, $3);
                # there can be several sessions per target (multipath)
-               push @{$res->{$target}}, $session;
+               my %session = ( session_id => $session_id, portal => $portal );
+               push @{$res->{$target}}, \%session;
            }
        });
     };
@@ -68,42 +72,77 @@ sub iscsi_test_portal {
     return PVE::Network::tcp_ping($server, $port || 3260, 2);
 }
 
-sub iscsi_discovery {
-    my ($portal) = @_;
+sub iscsi_portals {
+    my ($target, $portal_in) = @_;
 
     check_iscsi_support ();
 
-    my $res = {};
-    return $res if !iscsi_test_portal($portal); # fixme: raise exception here?
+    my $res = [];
+    my $cmd = [$ISCSIADM, '--mode', 'node'];
+    eval {
+       run_command($cmd, outfunc => sub {
+           my $line = shift;
 
-    my $cmd = [$ISCSIADM, '--mode', 'discovery', '--type', 'sendtargets', '--portal', $portal];
-    run_command($cmd, outfunc => sub {
-       my $line = shift;
+           if ($line =~ $ISCSI_TARGET_RE) {
+               my ($portal, $portal_target) = ($1, $2);
+               if ($portal_target eq $target) {
+                   push @{$res}, $portal;
+               }
+           }
+       });
+    };
 
-       if ($line =~ m/^((?:$IPV4RE|\[$IPV6RE\]):\d+)\,\S+\s+(\S+)\s*$/) {
-           my $portal = $1;
-           my $target = $2;
-           # one target can have more than one portal (multipath).
-           push @{$res->{$target}}, $portal;
-       }
-    });
+    if ($@) {
+       warn $@;
+       return [ $portal_in ];
+    }
+
+    return $res;
+}
+
+sub iscsi_discovery {
+    my ($portals) = @_;
+
+    check_iscsi_support ();
+
+    my $res = {};
+    for my $portal ($portals->@*) {
+       next if !iscsi_test_portal($portal); # fixme: raise exception here?
+
+       my $cmd = [$ISCSIADM, '--mode', 'discovery', '--type', 'sendtargets', '--portal', $portal];
+       eval {
+           run_command($cmd, outfunc => sub {
+               my $line = shift;
+
+               if ($line =~ $ISCSI_TARGET_RE) {
+                   my ($portal, $target) = ($1, $2);
+                   # one target can have more than one portal (multipath)
+                   # and sendtargets should return all of them in single call
+                   push @{$res->{$target}}, $portal;
+               }
+           });
+       };
+
+       # In case of multipath we can stop after receiving targets from any available portal
+       last if scalar(keys %$res) > 0;
+    }
 
     return $res;
 }
 
 sub iscsi_login {
-    my ($target, $portal_in) = @_;
+    my ($target, $portals) = @_;
 
     check_iscsi_support();
 
-    eval { iscsi_discovery($portal_in); };
+    eval { iscsi_discovery($portals); };
     warn $@ if $@;
 
     run_command([$ISCSIADM, '--mode', 'node', '--targetname',  $target, '--login']);
 }
 
 sub iscsi_logout {
-    my ($target, $portal) = @_;
+    my ($target) = @_;
 
     check_iscsi_support();
 
@@ -133,7 +172,7 @@ sub iscsi_session_rescan {
     }
 
     foreach my $session (@$session_list) {
-       my $cmd = [$ISCSIADM, '--mode', 'session', '--sid', $session, '--rescan'];
+       my $cmd = [$ISCSIADM, '--mode', 'session', '--sid', $session->{session_id}, '--rescan'];
        eval { run_command($cmd, outfunc => sub {}); };
        warn $@ if $@;
     }
@@ -379,14 +418,28 @@ sub activate_storage {
 
     return if !check_iscsi_support(1);
 
-    my $session = iscsi_session($cache, $scfg->{target});
+    my $sessions = iscsi_session($cache, $scfg->{target});
+    my $portals = iscsi_portals($scfg->{target}, $scfg->{portal});
+    my $do_login = !defined($sessions);
 
-    if (!defined ($session)) {
-       eval { iscsi_login($scfg->{target}, $scfg->{portal}); };
+    if (!$do_login) {
+       # We should check that sessions for all portals are available
+       my $session_portals = [ map { $_->{portal} } (@$sessions) ];
+
+       for my $portal (@$portals) {
+           if (!grep(/^\Q$portal\E$/, @$session_portals)) {
+               $do_login = 1;
+               last;
+           }
+       }
+    }
+
+    if ($do_login) {
+       eval { iscsi_login($scfg->{target}, $portals); };
        warn $@ if $@;
     } else {
        # make sure we get all devices
-       iscsi_session_rescan($session);
+       iscsi_session_rescan($sessions);
     }
 }
 
@@ -396,15 +449,21 @@ sub deactivate_storage {
     return if !check_iscsi_support(1);
 
     if (defined(iscsi_session($cache, $scfg->{target}))) {
-       iscsi_logout($scfg->{target}, $scfg->{portal});
+       iscsi_logout($scfg->{target});
     }
 }
 
 sub check_connection {
     my ($class, $storeid, $scfg) = @_;
 
-    my $portal = $scfg->{portal};
-    return iscsi_test_portal($portal);
+    my $portals = iscsi_portals($scfg->{target}, $scfg->{portal});
+
+    for my $portal (@$portals) {
+       my $result = iscsi_test_portal($portal);
+       return $result if $result;
+    }
+
+    return 0;
 }
 
 sub volume_resize {