[pve-devel] [PATCH qemu-server] add detect_zeroes option

Wolfgang Bumiller w.bumiller at proxmox.com
Thu Dec 17 14:58:12 CET 2015


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).
---
 PVE/QemuServer.pm | 31 +++++++++++++++++++++----------
 1 file changed, 21 insertions(+), 10 deletions(-)

diff --git a/PVE/QemuServer.pm b/PVE/QemuServer.pm
index c21955f..28d2193 100644
--- a/PVE/QemuServer.pm
+++ b/PVE/QemuServer.pm
@@ -532,7 +532,7 @@ 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);
@@ -540,7 +540,7 @@ 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);
@@ -548,7 +548,7 @@ 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);
@@ -556,7 +556,7 @@ 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);
@@ -925,8 +925,8 @@ 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) = @_;
@@ -947,7 +947,7 @@ 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';
@@ -985,6 +985,7 @@ 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);
 
@@ -1033,7 +1034,7 @@ 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};
     }
 
@@ -1261,8 +1262,18 @@ 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," : '';
 
-- 
2.1.4




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