[libvirt] [PATCH v2 09/11] qemu: Disallow pivot of shared disks to unsupported storage

Pivoting to a unsupported storage type might break the assumption that shared disks will not corrupt metadata. Resolves: https://bugzilla.redhat.com/show_bug.cgi?id=1511480 --- src/qemu/qemu_driver.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c index aa1f1e36d2..180f96ad5c 100644 --- a/src/qemu/qemu_driver.c +++ b/src/qemu/qemu_driver.c @@ -16501,6 +16501,16 @@ qemuDomainBlockPivot(virQEMUDriverPtr driver, goto cleanup; } + /* When pivoting to a shareable disk we need to make sure that the disk can + * be safely shared, since block copy might have changed the format. */ + if (disk->src->shared && !disk->src->readonly && + !qemuBlockStorageSourceSupportsConcurrentAccess(disk->mirror)) { + virReportError(VIR_ERR_OPERATION_UNSUPPORTED, "%s", + _("can't pivot a shared disk to a storage volume not " + "supporting sharing")); + goto cleanup; + } + /* For active commit, the mirror is part of the already labeled * chain. For blockcopy, we previously labeled only the top-level * image; but if the user is reusing an external image that -- 2.14.3