qemu: add separate rerror_policy for disk errors

Previously libvirt's disk device XML only had a single attribute, error_policy, to control both read and write error policy, but qemu has separate options for controlling read and write. In one case (enospc) a policy is allowed for write errors but not read errors. This patch adds a separate attribute that sets only the read error policy. If just error_policy is set, it will apply to both read and write error policy (previous behavior), but if the new rerror_policy attribute is set, it will override error_policy for read errors only. Possible values for rerror_policy are "stop", "report", and "ignore" ("report" is the qemu-controlled default for rerror_policy when error_policy isn't specified). For consistency, the value "report" has been added to the possible values for error_policy as well.
2024-12-22 21:55:25 +00:00 · 2011-10-04 14:17:06 -04:00 · 2011-10-04 14:17:06 -04:00 · 4bb4109f7b
commit 4bb4109f7b
parent 91195b4321
9 changed files with 105 additions and 6 deletions
--- a/docs/formatdomain.html.in
+++ b/docs/formatdomain.html.in
@ -1008,9 +1008,21 @@
          </li>
          <li>
            The optional <code>error_policy</code> attribute controls
-            how the hypervisor will behave on an error, possible
-            values are "stop", "ignore", and "enospace".
-            <span class="since">Since 0.8.0</span>
+            how the hypervisor will behave on a disk read or write
+            error, possible values are "stop", "report", "ignore", and
+            "enospace".<span class="since">Since 0.8.0, "report" since
+            0.9.7</span> The default setting of error_policy is "report".
+            There is also an
+            optional <code>rerror_policy</code> that controls behavior
+            for read errors only. <span class="since">Since
+            0.9.7</space>. If no rerror_policy is given, error_policy
+            is used for both read and write errors. If rerror_policy
+            is given, it overrides the <code>error_policy</code> for
+            read errors. Also note that "enospace" is not a valid
+            policy for read errors, so if <code>error_policy</code> is
+            set to "enospace" and no <code>rerror_policy</code> is
+            given, the read error policy will be left at its default,
+            which is "report".
          </li>
          <li>
            The optional <code>io</code> attribute controls specific
--- a/docs/schemas/domaincommon.rng
+++ b/docs/schemas/domaincommon.rng
@ -819,6 +819,9 @@
      <optional>
        <ref name="driverErrorPolicy"/>
      </optional>
+      <optional>
+        <ref name="driverRerrorPolicy"/>
+      </optional>
      <optional>
        <ref name="driverIO"/>
      </optional>
@ -856,11 +859,21 @@
    <attribute name="error_policy">
      <choice>
        <value>stop</value>
+        <value>report</value>
        <value>ignore</value>
        <value>enospace</value>
      </choice>
    </attribute>
  </define>
+  <define name="driverRerrorPolicy">
+    <attribute name="rerror_policy">
+      <choice>
+        <value>stop</value>
+        <value>report</value>
+        <value>ignore</value>
+      </choice>
+    </attribute>
+  </define>
  <define name="driverIO">
    <attribute name="io">
      <choice>
--- a/src/conf/domain_conf.c
+++ b/src/conf/domain_conf.c
@ -176,6 +176,7 @@ VIR_ENUM_IMPL(virDomainDiskCache, VIR_DOMAIN_DISK_CACHE_LAST,
 VIR_ENUM_IMPL(virDomainDiskErrorPolicy, VIR_DOMAIN_DISK_ERROR_POLICY_LAST,
              "default",
              "stop",
+              "report",
              "ignore",
              "enospace")

@ -2297,6 +2298,7 @@ virDomainDiskDefParseXML(virCapsPtr caps,
    char *bus = NULL;
    char *cachetag = NULL;
    char *error_policy = NULL;
+    char *rerror_policy = NULL;
    char *iotag = NULL;
    char *ioeventfd = NULL;
    char *event_idx = NULL;
@ -2416,6 +2418,7 @@ virDomainDiskDefParseXML(virCapsPtr caps,
                driverType = virXMLPropString(cur, "type");
                cachetag = virXMLPropString(cur, "cache");
                error_policy = virXMLPropString(cur, "error_policy");
+                rerror_policy = virXMLPropString(cur, "rerror_policy");
                iotag = virXMLPropString(cur, "io");
                ioeventfd = virXMLPropString(cur, "ioeventfd");
                event_idx = virXMLPropString(cur, "event_idx");
@ -2560,6 +2563,16 @@ virDomainDiskDefParseXML(virCapsPtr caps,
        goto error;
    }

+    if (rerror_policy &&
+        (((def->rerror_policy
+           = virDomainDiskErrorPolicyTypeFromString(rerror_policy)) <= 0) ||
+         (def->rerror_policy == VIR_DOMAIN_DISK_ERROR_POLICY_ENOSPACE))) {
+        virDomainReportError(VIR_ERR_INTERNAL_ERROR,
+                             _("unknown disk read error policy '%s'"),
+                             rerror_policy);
+        goto error;
+    }
+
    if (iotag) {
        if ((def->iomode = virDomainDiskIoTypeFromString(iotag)) < 0 ||
            def->iomode == VIR_DOMAIN_DISK_IO_DEFAULT) {
@ -2667,6 +2680,7 @@ cleanup:
    VIR_FREE(driverName);
    VIR_FREE(cachetag);
    VIR_FREE(error_policy);
+    VIR_FREE(rerror_policy);
    VIR_FREE(iotag);
    VIR_FREE(ioeventfd);
    VIR_FREE(event_idx);
@ -9127,6 +9141,7 @@ virDomainDiskDefFormat(virBufferPtr buf,
    const char *bus = virDomainDiskBusTypeToString(def->bus);
    const char *cachemode = virDomainDiskCacheTypeToString(def->cachemode);
    const char *error_policy = virDomainDiskErrorPolicyTypeToString(def->error_policy);
+    const char *rerror_policy = virDomainDiskErrorPolicyTypeToString(def->rerror_policy);
    const char *iomode = virDomainDiskIoTypeToString(def->iomode);
    const char *ioeventfd = virDomainIoEventFdTypeToString(def->ioeventfd);
    const char *event_idx = virDomainVirtioEventIdxTypeToString(def->event_idx);
@ -9177,6 +9192,8 @@ virDomainDiskDefFormat(virBufferPtr buf,
            virBufferAsprintf(buf, " cache='%s'", cachemode);
        if (def->error_policy)
            virBufferAsprintf(buf, " error_policy='%s'", error_policy);
+        if (def->rerror_policy)
+            virBufferAsprintf(buf, " rerror_policy='%s'", rerror_policy);
        if (def->iomode)
            virBufferAsprintf(buf, " io='%s'", iomode);
        if (def->ioeventfd)
--- a/src/conf/domain_conf.h
+++ b/src/conf/domain_conf.h
@ -209,6 +209,7 @@ enum  virDomainDiskCache {
 enum  virDomainDiskErrorPolicy {
    VIR_DOMAIN_DISK_ERROR_POLICY_DEFAULT,
    VIR_DOMAIN_DISK_ERROR_POLICY_STOP,
+    VIR_DOMAIN_DISK_ERROR_POLICY_REPORT,
    VIR_DOMAIN_DISK_ERROR_POLICY_IGNORE,
    VIR_DOMAIN_DISK_ERROR_POLICY_ENOSPACE,

@ -284,7 +285,8 @@ struct _virDomainDiskDef {
    char *driverType;
    char *serial;
    int cachemode;
-    int error_policy;
+    int error_policy;  /* enum virDomainDiskErrorPolicy */
+    int rerror_policy; /* enum virDomainDiskErrorPolicy */
    int bootIndex;
    int iomode;
    int ioeventfd;
--- a/src/qemu/qemu_command.c
+++ b/src/qemu/qemu_command.c
@ -1696,6 +1696,8 @@ qemuBuildDriveStr(virDomainDiskDefPtr disk,

        if (disk->error_policy)
            wpolicy = virDomainDiskErrorPolicyTypeToString(disk->error_policy);
+        if (disk->rerror_policy)
+            rpolicy = virDomainDiskErrorPolicyTypeToString(disk->rerror_policy);

        if (disk->error_policy == VIR_DOMAIN_DISK_ERROR_POLICY_ENOSPACE) {
            /* in the case of enospace, the option is spelled
@ -5631,14 +5633,22 @@ qemuParseCommandLineDisk(virCapsPtr caps,
                def->cachemode = VIR_DOMAIN_DISK_CACHE_DIRECTSYNC;
            else if (STREQ(values[i], "unsafe"))
                def->cachemode = VIR_DOMAIN_DISK_CACHE_UNSAFE;
-        } else if (STREQ(keywords[i], "werror") ||
-                   STREQ(keywords[i], "rerror")) {
+        } else if (STREQ(keywords[i], "werror")) {
            if (STREQ(values[i], "stop"))
                def->error_policy = VIR_DOMAIN_DISK_ERROR_POLICY_STOP;
+            else if (STREQ(values[i], "report"))
+                def->error_policy = VIR_DOMAIN_DISK_ERROR_POLICY_REPORT;
            else if (STREQ(values[i], "ignore"))
                def->error_policy = VIR_DOMAIN_DISK_ERROR_POLICY_IGNORE;
            else if (STREQ(values[i], "enospc"))
                def->error_policy = VIR_DOMAIN_DISK_ERROR_POLICY_ENOSPACE;
+        } else if (STREQ(keywords[i], "rerror")) {
+            if (STREQ(values[i], "stop"))
+                def->rerror_policy = VIR_DOMAIN_DISK_ERROR_POLICY_STOP;
+            else if (STREQ(values[i], "report"))
+                def->rerror_policy = VIR_DOMAIN_DISK_ERROR_POLICY_REPORT;
+            else if (STREQ(values[i], "ignore"))
+                def->rerror_policy = VIR_DOMAIN_DISK_ERROR_POLICY_IGNORE;
        } else if (STREQ(keywords[i], "index")) {
            if (virStrToLong_i(values[i], NULL, 10, &idx) < 0) {
                virDomainDiskDefFree(def);
@ -5674,6 +5684,9 @@ qemuParseCommandLineDisk(virCapsPtr caps,
        }
    }

+    if (def->rerror_policy == def->error_policy)
+        def->rerror_policy = 0;
+
    if (!def->src &&
        def->device == VIR_DOMAIN_DISK_DEVICE_DISK &&
        def->type != VIR_DOMAIN_DISK_TYPE_NETWORK) {
--- a/tests/qemuargv2xmltest.c
+++ b/tests/qemuargv2xmltest.c
@ -165,6 +165,7 @@ mymain(void)
    DO_TEST("disk-drive-cache-v1-none");
    DO_TEST("disk-drive-error-policy-stop");
    DO_TEST("disk-drive-error-policy-enospace");
+    DO_TEST("disk-drive-error-policy-wreport-rignore");
    DO_TEST("disk-drive-cache-v2-wt");
    DO_TEST("disk-drive-cache-v2-wb");
    DO_TEST("disk-drive-cache-v2-none");
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-wreport-rignore.args
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-wreport-rignore.args
@ -0,0 +1,6 @@
+LC_ALL=C PATH=/bin HOME=/home/test USER=test LOGNAME=test /usr/bin/qemu -S -M \
+pc -m 214 -smp 1 -nographic -monitor unix:/tmp/test-monitor,server,nowait \
+-no-acpi -boot c -drive file=/dev/HostVG/QEMUGuest1,if=ide,bus=0,unit=0,\
+format=qcow2,cache=off,werror=report,rerror=ignore -drive \
+file=/dev/HostVG/QEMUGuest2,if=ide,media=cdrom,bus=1,unit=0,format=raw -net \
+none -serial none -parallel none -usb
--- a/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-wreport-rignore.xml
+++ b/tests/qemuxml2argvdata/qemuxml2argv-disk-drive-error-policy-wreport-rignore.xml
@ -0,0 +1,33 @@
+<domain type='qemu'>
+  <name>QEMUGuest1</name>
+  <uuid>c7a5fdbd-edaf-9455-926a-d65c16db1809</uuid>
+  <memory>219136</memory>
+  <currentMemory>219136</currentMemory>
+  <vcpu>1</vcpu>
+  <os>
+    <type arch='i686' machine='pc'>hvm</type>
+    <boot dev='hd'/>
+  </os>
+  <clock offset='utc'/>
+  <on_poweroff>destroy</on_poweroff>
+  <on_reboot>restart</on_reboot>
+  <on_crash>destroy</on_crash>
+  <devices>
+    <emulator>/usr/bin/qemu</emulator>
+    <disk type='block' device='disk'>
+      <driver name='qemu' type='qcow2' cache='none' error_policy='report' rerror_policy='ignore'/>
+      <source dev='/dev/HostVG/QEMUGuest1'/>
+      <target dev='hda' bus='ide'/>
+      <address type='drive' controller='0' bus='0' unit='0'/>
+    </disk>
+    <disk type='block' device='cdrom'>
+      <driver name='qemu' type='raw'/>
+      <source dev='/dev/HostVG/QEMUGuest2'/>
+      <target dev='hdc' bus='ide'/>
+      <readonly/>
+      <address type='drive' controller='0' bus='1' unit='0'/>
+    </disk>
+    <controller type='ide' index='0'/>
+    <memballoon model='virtio'/>
+  </devices>
+</domain>
--- a/tests/qemuxml2argvtest.c
+++ b/tests/qemuxml2argvtest.c
@ -334,6 +334,8 @@ mymain(void)
            QEMU_CAPS_DRIVE, QEMU_CAPS_MONITOR_JSON, QEMU_CAPS_DRIVE_FORMAT);
    DO_TEST("disk-drive-error-policy-enospace", false,
            QEMU_CAPS_DRIVE, QEMU_CAPS_MONITOR_JSON, QEMU_CAPS_DRIVE_FORMAT);
+    DO_TEST("disk-drive-error-policy-wreport-rignore", false,
+            QEMU_CAPS_DRIVE, QEMU_CAPS_MONITOR_JSON, QEMU_CAPS_DRIVE_FORMAT);
    DO_TEST("disk-drive-cache-v2-wt", false,
            QEMU_CAPS_DRIVE, QEMU_CAPS_DRIVE_CACHE_V2, QEMU_CAPS_DRIVE_FORMAT);
    DO_TEST("disk-drive-cache-v2-wb", false,