Re: [libvirt] [PATCH 2/4] qemu: introduce CHECK_STREQ_NULLABLE in qemuDomainDiskChangeSupported
On 3/28/19 10:34 AM, Ján Tomko wrote:
A marco for comparing string fields of the disk.
Polo'ed-by: Laine Stump <laine(a)laine.org>
(seriously, though - s/marco/macro/ :-)
https://bugzilla.redhat.com/show_bug.cgi?id=1601677
Signed-off-by: Ján Tomko <jtomko(a)redhat.com>
---
src/qemu/qemu_domain.c | 13 +++++++++++++
1 file changed, 13 insertions(+)
diff --git a/src/qemu/qemu_domain.c b/src/qemu/qemu_domain.c
index bb3a672d47..72e322d6a7 100644
--- a/src/qemu/qemu_domain.c
+++ b/src/qemu/qemu_domain.c
@@ -9322,6 +9322,18 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
} \
} while (0)
+#define CHECK_STREQ_NULLABLE(field, field_name) \
+ do { \
+ if (!disk->field) \
+ break; \
So is a missing value in the updated XML equal to "no change"? Or Does a
missing value actually mean "this should be un-set if it has been set to
something"?
(I'm asking this because in the case of MTU for <interface>, if the
existing interface has an mtu set (even to 1500), and the updated XML
has no MTU, we consider that a change (and don't allow it).
Reviewed-by: Laine Stump <laine(a)laine.org>
once the commit message typo is fixed, and if the meaning of "not
specified" for a field in the update truly is meant to be "don't
change"
rather than "remove any previous setting of this field and return it to
default".
+ if (STRNEQ_NULLABLE(disk->field, orig_disk->field)) {
\
+ virReportError(VIR_ERR_OPERATION_UNSUPPORTED, \
+ _("cannot modify field '%s' of the disk"),
\
+ field_name); \
+ return false; \
+ } \
+ } while (0)
+
CHECK_EQ(device, "device", false);
CHECK_EQ(bus, "bus", false);
if (STRNEQ(disk->dst, orig_disk->dst)) {
@@ -9469,6 +9481,7 @@ qemuDomainDiskChangeSupported(virDomainDiskDefPtr disk,
}
#undef CHECK_EQ
+#undef CHECK_STREQ_NULLABLE
return true;
}