Re: [libvirt] [PATCH] qemu: Add missing VIR_DOMAIN_BLOCK_COMMIT_DELETE flags

On 27.08.2013 10:58, Alex Jia wrote: > On 08/27/2013 04:47 PM, Peter Krempa wrote: >> On 08/27/13 09:53, Alex Jia wrote: >>> The flag "VIR_DOMAIN_BLOCK_COMMIT_DELETE" is missed by >>> qemuDomainBlockCommit(), >>> and then will hit error "unsupported flags (0x2) in function >>> qemuDomainBlockCommit" if users run 'virsh blockcommit' with >>> '--delete' option. >>> >>> RHBZ: https://bugzilla.redhat.com/show_bug.cgi?id=1001475 >>> >>> Signed-off-by: Alex Jia&lt;ajia(a)redhat.com&gt; >>> --- >>> src/qemu/qemu_driver.c | 3 ++- >>> 1 files changed, 2 insertions(+), 1 deletions(-) >>> >>> diff --git a/src/qemu/qemu_driver.c b/src/qemu/qemu_driver.c >>> index ed29373..8863124 100644 >>> --- a/src/qemu/qemu_driver.c >>> +++ b/src/qemu/qemu_driver.c >>> @@ -14444,7 +14444,8 @@ qemuDomainBlockCommit(virDomainPtr dom, const >>> char *path, const char *base, >>> const char *base_canon = NULL; >>> bool clean_access = false; >>> >>> - virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW, -1); >>> + virCheckFlags(VIR_DOMAIN_BLOCK_COMMIT_SHALLOW | >>> + VIR_DOMAIN_BLOCK_COMMIT_DELETE, -1); >>> >>> if (!(vm = qemuDomObjFromDomain(dom))) >>> goto cleanup; >>> >> The code doesn't seem to support the BLOCK_COMMIT_DELETE flag. It was > > Yes, the codes haven't any implementation for BLOCK_COMMIT_DELETE flag > now, maybe, only need to raise a friendly error message in here instead > of "unsupported flags (0x2) xxxx". I agree that this error message is not user-friendly. Bare virsh users know nothing about our flags and their numerical expression. However, I don't think there is a way how to produce "Unsupported flag VIR_DOMAIN_BLOCK_COMMIT_DELETE" instead of "Unsupported flag 0x2" since all we see in the qemuDomainBlockCommit() function is just number. I mean, mapping of flag onto numeric value is not one-to-one function (aka injective function). That is, a value 0x2 can express VIR_DOMAIN_BLOCK_COMMIT_DELETE, VIR_DOMAIN_START_AUTODESTROY, VIR_DUMP_DESTROY, etc. (git grep "1 << 1," include/). If we want to make it work, we have to introduce an injective function, e.g. virUnsupportedFlags(), which would accept a list (not an ORed value) of all flags that are not supported. Too much effort for not much outcome.

Michal