Re: [libvirt] [PATCH] qemu: Adjust size for qcow2/qed if not on sector boundary

>>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >>> index 4bb4819..3e407d7 100644 >>> --- a/src/qemu/qemu_driver.c >>> +++ b/src/qemu/qemu_driver.c >>> @@ -9421,6 +9421,7 @@ qemuDomainBlockResize(virDomainPtr dom, >>> virDomainObjPtr vm; >>> qemuDomainObjPrivatePtr priv; >>> int ret = -1, idx; >>> + unsigned long long size_up; >>> char *device = NULL; >>> virDomainDiskDefPtr disk = NULL; >>> >>> @@ -9467,6 +9474,21 @@ qemuDomainBlockResize(virDomainPtr dom, >>> } >>> disk = vm->def->disks[idx]; >>> >>> + /* qcow2 and qed must be sized appropriately, so be sure our value >>> + * is sized appropriately and will fit >>> + */ >>> + if (size != size_up && >>> + (disk->src.format == VIR_STORAGE_FILE_QCOW2 || >>> + disk->src.format == VIR_STORAGE_FILE_QED)) { >>> + if (size_up > ULLONG_MAX) { > > This is always false. > An OVERLy cautious check - I cannot remember what I was thinking about a month ago... I think this was the check can VIR_ROUND_UP provide an incorrect value. I can send a follow-up patch to remove those lines if that's desired.

>>> + virReportError(VIR_ERR_OVERFLOW, >>> + _("size must be less than %llu KiB"), >>> + ULLONG_MAX / 1024); >>> + goto endjob; >>> + } >>> + size = size_up; > > Just a nitpick: rounding it up unconditionally here would get rid of the > temporary variable and have no effect on values specified without the BYTES flag. > Only qcow2 and qed have this issue regarding needing to be on a 512 byte boundary. Since this is a generic routine I was limiting the rounding to the two types from the bz rather than taking a chance that some generic round up would cause some other issue. Or am I misinterpreting your comment?