Re: [libvirt] [PATCH v3] virsh: avoid missing zero value judgement in cmdBlkiotune

On 07/28/2011 05:50 PM, Wen Congyang wrote: > At 07/28/2011 05:52 PM, Alex Jia Write: >> * tools/virsh.c: avoid missing zero value judgement in cmdBlkiotune, >> when >> weight is equal to 0, the cmdBlkiotune will not raise any error >> information >> when judge weight value first time, and execute else branch to judge >> weight >> value again, strncpy(temp->field, VIR_DOMAIN_BLKIO_WEIGHT, >> sizeof(temp->field)) >> will be not executed for ever. However, if and only if param->field >> is equal >> to VIR_DOMAIN_BLKIO_WEIGHT, underlying qemuDomainSetBlkioParameters >> function >> will check whether weight value is in range [100, 1000]. >> >> * how to reproduce? >> >> % virsh blkiotune ${guestname} --weight 0 >> >> Signed-off-by: Alex Jia&lt;ajia(a)redhat.com&gt; >> --- >> tools/virsh.c | 6 +++--- >> 1 files changed, 3 insertions(+), 3 deletions(-) >> >> diff --git a/tools/virsh.c b/tools/virsh.c >> index 8bd22dc..f24050d 100644 >> --- a/tools/virsh.c >> +++ b/tools/virsh.c >> @@ -4037,12 +4037,12 @@ cmdBlkiotune(vshControl * ctl, const vshCmd * >> cmd) >> goto cleanup; >> } >> >> - if (weight) { >> - nparams++; >> - if (weight< 0) { >> + if (vshCommandOptInt(cmd, "weight",&weight)> 0) { > Why you call vshCommandOptInt(cmd, "weight",&weight) again? Make sure weight indeed exists and then checking whether its value is right. if do it like this: if (weight<= 0) { vshError(ctl, _("Invalid value of %d for I/O weight"), weight); goto cleanup; } nparams++; ...... when I run virsh blkiotune ${guestname} --weight 0, I will not hit this error, and when I get weight value by virsh blkiotune ${guestname}, this error will be hit, because vshCommandOptInt(cmd, "weight",&weight) will return 0 and unchange weight value, it means weight will keep initial 0 value, hence vshError will be raise. Thanks, Alex