[libvirt] [PATCH 2/2] qemu: migration: Ignore null ptr in qemuMigrationStopNBDServer
qemuMigrationCookiePtr mig->nbd may be null when MigrationCookie do not have nbd information ,but nbd port did allocated before and must be released here, so ignore mig->nbd null ptr and just warn. Signed-off-by: Weiwei Li <nuonuoli@tencent.com> --- src/qemu/qemu_migration.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 0ad8054..134b041 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1584,7 +1584,7 @@ qemuMigrationStopNBDServer(virQEMUDriverPtr driver, qemuDomainObjPrivatePtr priv = vm->privateData; if (!mig->nbd) - return; + VIR_WARN("mig->nbd is null"); if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0) -- 1.7.1
On 10/31/2014 09:17 AM, weiwei li wrote:
qemuMigrationCookiePtr mig->nbd may be null when MigrationCookie do not have nbd information ,but nbd port did allocated before and must be released here, so ignore mig->nbd null ptr and just warn.
StartNBDServer is only run when mig->nbd is present, so if it's not there we didn't start the server or allocate the port. Are you sure this patch is necessary? Jan
Signed-off-by: Weiwei Li <nuonuoli@tencent.com <mailto:nuonuoli@tencent.com>> --- src/qemu/qemu_migration.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 0ad8054..134b041 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1584,7 +1584,7 @@ qemuMigrationStopNBDServer(virQEMUDriverPtr driver, qemuDomainObjPrivatePtr priv = vm->privateData;
if (!mig->nbd) - return; + VIR_WARN("mig->nbd is null");
if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
mig->nbd is initialized by qemuMigrationCookieXMLParse（called by qemuMigrationEatCookie），with a condition that the nbd infomation contained in Cookie string. I found in debug info that qemuMigrationStartNBDServer had been called in qemuMigrationPrepareAny（mig->nbd not null）, but at in qemuMigrationFinish qemuMigrationStopNBDServer can not really stop nbd server bucause mig->nbd is not initialized(that is because cookie string does not contain nbd information ). so ,there are two solutions: 1 qemuMigrationStopNBDServer ignore mig->nbd null ptr 2 add cookie info for nbd same stage (that is lost in which stage i am not sure~ ) I choose an easy way solution 1 with least code changing， maybe is not google way ：） cookie log is like this: 2014-10-30 08:38:14.106+0000: 15078: debug : qemuMigrationRun:3254 : driver=0x7f936413cd40, vm=0x7f934400b850, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <nbd port='49153'/> </qemu-migration> 2014-10-30 08:39:12.527+0000: 15076: debug : virObjectRef:296 : OBJECT_REF: obj=0x7f9364138880 2014-10-30 08:39:12.527+0000: 15076: debug : qemuMigrationFinish:4507 : driver=0x7f936413cd40, dconn=0x7f9358002720, vm=0x7f935c002da0, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <feature name='persistent'/> <domain type='kvm'> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <memory unit='KiB'>2097152</memory> <currentMemory unit='KiB'>2097152</currentMemory> <vcpu placement='static' cpuset='0-7'>2</vcpu> <os> <type arch='x86_64' machine='pc-i440fx-2.0'>hvm</type> <boot dev='hd'/> </os> <features> <acpi/> <apic/> <pae/> </features> <clock offset='localtime'/> <on_poweroff>destroy</on_poweroff> <on_reboot>restart</on_reboot> <on_crash>restart</on_crash> <devices> <emulator>/usr/bin/qemu-system-x86_64</emulator> <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/tvm/tvm/3cd4c349-e058-4a1a-8b3d-cc988efd11e2/tlinux1.2-tvm-64bit-2.2-20140716_incremental.qcow2'/> <target dev='vda' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x04' function='0x0'/> </disk> <disk type='file' device='disk'> <driver name='qemu' type='qcow2' cache='none'/> <source file='/tvm/tvm/3cd4c349-e058-4a1a-8b3d-cc988efd11e2/EXT3_50G.qcow2_incremental.qcow2'/> <target dev='vdb' bus='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x05' function='0x0'/> </disk> <interface type='bridge'> <mac address='54:52:00:02:b2:32'/> <source bridge='br1'/> <model type='virtio'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x03' function='0x0'/> </interface> <serial type='pty'> <target port='0'/> </serial> <console type='pty'> <target type='serial' port='0'/> </console> <input type='mouse' bus='ps2'/> <graphics type='vnc' port='-1' autoport='yes' listen='0.0.0.0'> <listen type='address' address='0.0.0.0'/> </graphics> <video> <model type='cirrus' vram='9216' heads='1'/> <address type='pci' domain='0x0000' bus='0x00' slot='0x02' function='0x0'/> </video> <memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> </domain> <nbd/> </qemu-migration> , cookieinlen=2567, cookieout=0x7f93722eab08, cookieoutlen=0x7f93722eab14, flags=289, retcode=0 2014-10-31 18:05 GMT+08:00 Ján Tomko <jtomko@redhat.com>:
On 10/31/2014 09:17 AM, weiwei li wrote:
qemuMigrationCookiePtr mig->nbd may be null when MigrationCookie do not have nbd information ,but nbd port did allocated before and must be released here, so ignore mig->nbd null ptr and just warn.
StartNBDServer is only run when mig->nbd is present, so if it's not there we didn't start the server or allocate the port. Are you sure this patch is necessary?
Jan
Signed-off-by: Weiwei Li <nuonuoli@tencent.com <mailto:
nuonuoli@tencent.com>>
--- src/qemu/qemu_migration.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-)
diff --git a/src/qemu/qemu_migration.c b/src/qemu/qemu_migration.c index 0ad8054..134b041 100644 --- a/src/qemu/qemu_migration.c +++ b/src/qemu/qemu_migration.c @@ -1584,7 +1584,7 @@ qemuMigrationStopNBDServer(virQEMUDriverPtr driver, qemuDomainObjPrivatePtr priv = vm->privateData;
if (!mig->nbd) - return; + VIR_WARN("mig->nbd is null");
if (qemuDomainObjEnterMonitorAsync(driver, vm, QEMU_ASYNC_JOB_MIGRATION_IN) < 0)
On 11/03/2014 05:22 AM, weiwei li wrote:
mig->nbd is initialized by qemuMigrationCookieXMLParse（called by qemuMigrationEatCookie），with a condition that the nbd infomation contained in Cookie string. I found in debug info that qemuMigrationStartNBDServer had been called in qemuMigrationPrepareAny（mig->nbd not null）, but at in qemuMigrationFinish qemuMigrationStopNBDServer can not really stop nbd server bucause mig->nbd is not initialized(that is because cookie string does not contain nbd information ).
so ,there are two solutions: 1 qemuMigrationStopNBDServer ignore mig->nbd null ptr 2 add cookie info for nbd same stage (that is lost in which stage i am not sure~ )
I choose an easy way solution 1 with least code changing， maybe is not google way ：）
cookie log is like this: 2014-10-30 08:38:14.106+0000: 15078: debug : qemuMigrationRun:3254 : driver=0x7f936413cd40, vm=0x7f934400b850, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <nbd port='49153'/> </qemu-migration>
2014-10-30 08:39:12.527+0000: 15076: debug : virObjectRef:296 : OBJECT_REF: obj=0x7f9364138880 2014-10-30 08:39:12.527+0000: 15076: debug : qemuMigrationFinish:4507 : driver=0x7f936413cd40, dconn=0x7f9358002720, vm=0x7f935c002da0, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <feature name='persistent'/>
...
<memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> </domain>
<nbd/>
So the <nbd/> element is there, we just don't parse it because qemuMigrationFinish calls qemuMigrationEatCookie without the QEMU_MIGRATION_COOKIE_NBD flag. I believe the proper fix is to add this flag there. Jan
</qemu-migration> , cookieinlen=2567, cookieout=0x7f93722eab08, cookieoutlen=0x7f93722eab14, flags=289, retcode=0
agree，I have tested the flag and it works well, i will post another patch later. Thanks very much! 2014-11-03 20:03 GMT+08:00 Ján Tomko <jtomko@redhat.com>:
On 11/03/2014 05:22 AM, weiwei li wrote:
mig->nbd is initialized by qemuMigrationCookieXMLParse（called by qemuMigrationEatCookie），with a condition that the nbd infomation contained in Cookie string. I found in debug info that qemuMigrationStartNBDServer had been called in qemuMigrationPrepareAny（mig->nbd not null）, but at in qemuMigrationFinish qemuMigrationStopNBDServer can not really stop nbd server bucause mig->nbd is not initialized(that is because cookie string does not contain nbd information ).
so ,there are two solutions: 1 qemuMigrationStopNBDServer ignore mig->nbd null ptr 2 add cookie info for nbd same stage (that is lost in which stage i am not sure~ )
I choose an easy way solution 1 with least code changing， maybe is not google way ：）
cookie log is like this: 2014-10-30 08:38:14.106+0000: 15078: debug : qemuMigrationRun:3254 : driver=0x7f936413cd40, vm=0x7f934400b850, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <nbd port='49153'/> </qemu-migration>
2014-10-30 08:39:12.527+0000: 15076: debug : virObjectRef:296 : OBJECT_REF: obj=0x7f9364138880 2014-10-30 08:39:12.527+0000: 15076: debug : qemuMigrationFinish:4507 : driver=0x7f936413cd40, dconn=0x7f9358002720, vm=0x7f935c002da0, cookiein=<qemu-migration> <name>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</name> <uuid>3cd4c349-e058-4a1a-8b3d-cc988efd11e2</uuid> <hostname>50e54929-059c-ffff-ffff-ffffffffffff_10.180.39.36</hostname> <hostuuid>50e54929-059c-ffff-ffff-ffffffffffff</hostuuid> <feature name='persistent'/>
...
<memballoon model='virtio'> <address type='pci' domain='0x0000' bus='0x00' slot='0x06' function='0x0'/> </memballoon> </devices> </domain>
<nbd/>
So the <nbd/> element is there, we just don't parse it because qemuMigrationFinish calls qemuMigrationEatCookie without the QEMU_MIGRATION_COOKIE_NBD flag.
I believe the proper fix is to add this flag there.
Jan
</qemu-migration> , cookieinlen=2567, cookieout=0x7f93722eab08, cookieoutlen=0x7f93722eab14, flags=289, retcode=0
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