add detect_zeroes option

On some storages BLKZEROOUT commands do not work properly
and return without error while having no effect whatsoever.
This can produce various filesystem errors and thus needs
to be made optional.

A drive can now have 'detect_zeroes=off' to disable this
behavior. By default the behavior is the same as before:
always-on (and set to 'unmap' if discard is enabled).

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index d15db5d3597b39f6f0aaba16e353216193d3c0cf..13e96092dc183f40a38289b200b94dfbdd585d85 100644 (file)
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -489,7 +489,7 @@ my $drivename_hash;
 my $idedesc = {
     optional => 1,
     type => 'string', format => 'pve-qm-drive',
-    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads] [,discard=ignore|on] [,serial=serial][,model=model]',
+    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads] [,discard=ignore|on] [,detect_zeroes=on|off] [,serial=serial][,model=model]',
     description => "Use volume as IDE hard disk or CD-ROM (n is 0 to " .($MAX_IDE_DISKS -1) . ").",
 };
 PVE::JSONSchema::register_standard_option("pve-qm-ide", $idedesc);
@@ -497,7 +497,7 @@ PVE::JSONSchema::register_standard_option("pve-qm-ide", $idedesc);
 my $scsidesc = {
     optional => 1,
     type => 'string', format => 'pve-qm-drive',
-    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads] [,discard=ignore|on] [,iothread=on] [,queues=<nbqueues>] [,serial=serial]',
+    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads] [,discard=ignore|on] [,detect_zeroes=on|off] [,iothread=on] [,queues=<nbqueues>] [,serial=serial]',
     description => "Use volume as SCSI hard disk or CD-ROM (n is 0 to " . ($MAX_SCSI_DISKS - 1) . ").",
 };
 PVE::JSONSchema::register_standard_option("pve-qm-scsi", $scsidesc);
@@ -505,7 +505,7 @@ PVE::JSONSchema::register_standard_option("pve-qm-scsi", $scsidesc);
 my $satadesc = {
     optional => 1,
     type => 'string', format => 'pve-qm-drive',
-    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads]  [,discard=ignore|on] [,serial=serial]',
+    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads]  [,discard=ignore|on] [,detect_zeroes=on|off] [,serial=serial]',
     description => "Use volume as SATA hard disk or CD-ROM (n is 0 to " . ($MAX_SATA_DISKS - 1). ").",
 };
 PVE::JSONSchema::register_standard_option("pve-qm-sata", $satadesc);
@@ -513,7 +513,7 @@ PVE::JSONSchema::register_standard_option("pve-qm-sata", $satadesc);
 my $virtiodesc = {
     optional => 1,
     type => 'string', format => 'pve-qm-drive',
-    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads]  [,discard=ignore|on] [,iothread=on] [,serial=serial]',
+    typetext => '[volume=]volume,] [,media=cdrom|disk] [,cyls=c,heads=h,secs=s[,trans=t]] [,snapshot=on|off] [,cache=none|writethrough|writeback|unsafe|directsync] [,format=f] [,backup=yes|no] [,rerror=ignore|report|stop] [,werror=enospc|ignore|report|stop] [,aio=native|threads]  [,discard=ignore|on] [,detect_zeroes=on|off] [,iothread=on] [,serial=serial]',
     description => "Use volume as VIRTIO hard disk (n is 0 to " . ($MAX_VIRTIO_DISKS - 1) . ").",
 };
 PVE::JSONSchema::register_standard_option("pve-qm-virtio", $virtiodesc);
@@ -882,8 +882,8 @@ my $format_size = sub {
 # ideX = [volume=]volume-id[,media=d][,cyls=c,heads=h,secs=s[,trans=t]]
 #        [,snapshot=on|off][,cache=on|off][,format=f][,backup=yes|no]
 #        [,rerror=ignore|report|stop][,werror=enospc|ignore|report|stop]
-#        [,aio=native|threads][,discard=ignore|on][,iothread=on]
-#        [,serial=serial][,model=model]
+#        [,aio=native|threads][,discard=ignore|on][,detect_zeroes=on|off]
+#        [,iothread=on][,serial=serial][,model=model]
 
 sub parse_drive {
     my ($key, $data) = @_;
@@ -904,7 +904,7 @@ sub parse_drive {
     foreach my $p (split (/,/, $data)) {
        next if $p =~ m/^\s*$/;
 
-       if ($p =~ m/^(file|volume|cyls|heads|secs|trans|media|snapshot|cache|format|rerror|werror|backup|aio|bps|mbps|mbps_max|bps_rd|mbps_rd|mbps_rd_max|bps_wr|mbps_wr|mbps_wr_max|iops|iops_max|iops_rd|iops_rd_max|iops_wr|iops_wr_max|size|discard|iothread|queues|serial|model)=(.+)$/) {
+       if ($p =~ m/^(file|volume|cyls|heads|secs|trans|media|snapshot|cache|format|rerror|werror|backup|aio|bps|mbps|mbps_max|bps_rd|mbps_rd|mbps_rd_max|bps_wr|mbps_wr|mbps_wr_max|iops|iops_max|iops_rd|iops_rd_max|iops_wr|iops_wr_max|size|discard|detect_zeroes|iothread|queues|serial|model)=(.+)$/) {
            my ($k, $v) = ($1, $2);
 
            $k = 'file' if $k eq 'volume';
@@ -942,6 +942,7 @@ sub parse_drive {
     return undef if $res->{backup} && $res->{backup} !~ m/^(yes|no)$/;
     return undef if $res->{aio} && $res->{aio} !~ m/^(native|threads)$/;
     return undef if $res->{discard} && $res->{discard} !~ m/^(ignore|on)$/;
+    return undef if $res->{detect_zeroes} && $res->{detect_zeroes} !~ m/^(on|off)$/;
     return undef if $res->{iothread} && $res->{iothread} !~ m/^(on)$/;
     return undef if $res->{queues} && ($res->{queues} !~ m/^\d+$/ || $res->{queues} < 2);
 
@@ -990,7 +991,7 @@ sub print_drive {
     my ($vmid, $drive) = @_;
 
     my $opts = '';
-    foreach my $o (@qemu_drive_options, 'mbps', 'mbps_rd', 'mbps_wr', 'mbps_max', 'mbps_rd_max', 'mbps_wr_max', 'backup', 'iothread', 'queues') {
+    foreach my $o (@qemu_drive_options, qw(mbps mbps_rd mbps_wr mbps_max mbps_rd_max mbps_wr_max backup iothread queues detect_zeroes)) {
        $opts .= ",$o=$drive->{$o}" if $drive->{$o};
     }
 
@@ -1218,8 +1219,18 @@ sub print_drive_full {
        }
     }
 
-    my $detectzeroes = $drive->{discard} ? "unmap" : "on";
-    $opts .= ",detect-zeroes=$detectzeroes" if !drive_is_cdrom($drive);
+    if (!drive_is_cdrom($drive)) {
+       my $detectzeroes;
+       if ($drive->{detect_zeroes} && $drive->{detect_zeroes} eq 'off') {
+           $detectzeroes = 'off';
+       } elsif ($drive->{discard}) {
+           $detectzeroes = $drive->{discard} eq 'on' ? 'unmap' : 'on';
+       } else {
+           # This used to be our default with discard not being specified:
+           $detectzeroes = 'on';
+       }
+       $opts .= ",detect-zeroes=$detectzeroes" if $detectzeroes;
+    }
 
     my $pathinfo = $path ? "file=$path," : '';