[libvirt] [PATCH v5 3/5] storage: add support for creating qcow2 images with extensions

[Ján Tomko]

On 06/21/2013 08:40 PM, John Ferlan wrote:
> On 06/19/2013 11:24 AM, Ján Tomko wrote:

>> +    if (features && format == VIR_STORAGE_FILE_QCOW2) {
>> +        for (i = 0; i < VIR_STORAGE_FILE_FEATURE_LAST; i++) {
>> +            ignore_value(virBitmapGetBit(features, i, &b));
>> +            if (b) {
>> +                switch (i) {
>> +                case VIR_STORAGE_FILE_FEATURE_LAZY_REFCOUNTS:
>> +                    if (STREQ(compat, "0.10")) {
>> +                        virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>> +                                       _("Feature %s not supported with compat"
>> +                                         " level %s"),
>> +                                       virStorageFileFeatureTypeToString(i),
>> +                                       compat);
>> +                        goto error;
>> +                    }
>> +                    break;
> 
> 
> With the patches for virNetDevSetupControlFull() my Coverity now runs;
> however, it's not very happy here...
> 
> The pushed source code  has:
> ...
> +                case VIR_STORAGE_FILE_FEATURE_NONE:
> +                case VIR_STORAGE_FILE_FEATURE_LAST:
> +                    ;
> 
> But VIR_STORAGE_FILE_FEATURE_NONE = -1 and VIR_STORAGE_FILE_FEATURE_LAST
> is used as the loop ender and thus Coverity deems the code unreachable
> eliciting a "DEADCODE" error since 'i' could never be one or the other.
> 
> I suppose the loop could change to:
> 
> for (i = VIR_STORAGE_FILE_FEATURE_NONE;
>      i <= VIR_STORAGE_FILE_FEATURE_LAST; i++)
> 
> but that'd cause virBitmapGetBit() failure since 'i' cannot be negative
> in the call to it.
> 
> John
> 

I've pushed a fix for that:

commit 7a99eb912f8c99c23dc3e015a35224fc2c925459
Author:     Ján Tomko <jtomko at redhat.com>
AuthorDate: 2013-06-24 08:35:59 +0200
Commit:     Ján Tomko <jtomko at redhat.com>
CommitDate: 2013-06-24 08:44:46 +0200

    Get rid of useless VIR_STORAGE_FILE_FEATURE_NONE

    It's not used anywhere except for the switch in
    virStorageBackendCreateQemuImgOpts, where leaving it in causes
    a dead code coverity warning and omitting it breaks compilation
    because of unhandled enum value.

    Introduced by 6298f74.

git describe: v1.0.6-119-g7a99eb9

Jan