Re: [libvirt] [PATCH v2 1/2] qemu: make attaching disk partition to VM illegal

On 9/30/19 3:41 PM, Pavel Mores wrote: > The way in which the qemu driver generates aliases for disks involves > ignoring the partition number part of a target dev name. This means that > all partitions of a block device and the device itself all end up with the > same alias. If multiple such disks are specified in XML, the resulting > name clash makes qemu invocation fail. > > Since attaching partitions to qemu VMs doesn't seem to make much sense > anyway, disallow partitions in target specifications altogether. > > https://bugzilla.redhat.com/show_bug.cgi?id=1346265 > > Signed-off-by: Pavel Mores <pmores(a)redhat.com&gt; > --- > src/qemu/qemu_domain.c | 15 +++++++++++ > .../disk-attaching-partition-nosupport.xml | 27 +++++++++++++++++++ > tests/qemuxml2argvtest.c | 1 + > 3 files changed, 43 insertions(+) > create mode 100644 tests/qemuxml2argvdata/disk-attaching-partition-nosupport.xml > > diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c > index e8e895d9aa..545c985f40 100644 > --- a/src/qemu/qemu_domain.c > +++ b/src/qemu/qemu_domain.c > @@ -5880,6 +5880,8 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk, > { > const char *driverName = virDomainDiskGetDriver(disk); > virStorageSourcePtr n; > + int idx; > + int partition; > if (disk->src->shared && !disk->src->readonly && > !qemuBlockStorageSourceSupportsConcurrentAccess(disk->src)) { > @@ -5948,6 +5950,19 @@ qemuDomainDeviceDefValidateDisk(const virDomainDiskDef *disk, > return -1; > } > + if (virDiskNameParse(disk->dst, &idx, &partition) < 0) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, > + _("invalid disk target '%s'"), disk->dst); > + return -1; > + } > + > + if (partition != 0) { > + virReportError(VIR_ERR_CONFIG_UNSUPPORTED, > + _("can't attach disk partition '%s', please attach whole disk instead"), > + disk->dst); Hopefully it's not too late, but this error message and the commit title neither don't look okay. You can attach /dev/sda1 to a domain, but we don't want you to put "sda1" into the disk target, we want you to name it just "sda". So perhaps "Refuse partitions in disk targets" as commit tile and "invalid disk target '%s', partitions can't appear in disk targets" for the error message looks better? The patch looks goot otherwise. Currently we are in a freeze, but since this is a bug fix it can go in. Objections anybody? I volunteer to merge it.