Re: [libvirt] [PATCH 1/3] conf/domain_conf: usevirStringParseYesNohelper

On 10/16/19 12:10 PM, maozy wrote: > Hi, Michal > > On 10/16/19 4:38 PM, Michal Privoznik wrote: >> On 10/16/19 4:39 AM, Mao Zhongyi wrote: >>> This helper performs a conversion from a "yes|no" string >>> to a corresponding boolean, and several conversions were >>> already done, but there are still some omissions. >>> >>> For most of the remaining usages in domain_conf.c only >>> "yes" is explicitly checked for. This means all other >>> values are implicitly handled as 'false'. In this case, >>> use virStringParseYesNo, but if it returns -1, don't >>> raise an error but set the bool value to false. >>> >>> Cc: crobinso(a)redhat.com >>> Cc: berrange(a)redhat.com >>> Cc: abologna(a)redhat.com >>> Cc: laine(a)laine.org >>> Cc: phrdina(a)redhat.com >>> Cc: mkletzan(a)redhat.com >>> Cc: g.sho1500(a)gmail.com >>> >>> Signed-off-by: Mao Zhongyi <maozhongyi(a)cmss.chinamobile.com&gt; >>> Signed-off-by: Zhang Shengju <zhangshengju(a)cmss.chinamobile.com&gt; >>> --- >>>   src/conf/domain_conf.c | 30 ++++++++++++++---------------- >>>   1 file changed, 14 insertions(+), 16 deletions(-) >>> >>> diff --git a/src/conf/domain_conf.c b/src/conf/domain_conf.c >>> index 10d6bf0eea..7420658726 100644 >>> --- a/src/conf/domain_conf.c >>> +++ b/src/conf/domain_conf.c >>> @@ -7601,8 +7601,8 @@ >>> virDomainHostdevSubsysUSBDefParseXML(xmlNodePtr node, >>>       } >>>       if ((autoAddress = virXMLPropString(node, "autoAddress"))) { >>> -        if (STREQ(autoAddress, "yes")) >>> -            usbsrc->autoAddress = true; >>> +        if (virStringParseYesNo(autoAddress, &usbsrc->autoAddress) >>> < 0) >>> +            usbsrc->autoAddress = false; >> >> I think we should either report a proper error here or don't touch >> this line (because this attribute is generated by libvirt itself, it >> doesn't come from an user). > > This patch replaces all STREQs that explicitly handle 'yes' to true, > reserving the original implicitly handling of other values to false, > so not report an error, which is also the recommendation of Cole > Robinson in BiteSizedtasks. Therefor, I'm not very sure whether it > is better to report an error in this case? If indeed, will fix it in v2. Alright then. But what we can use then is: ignore_value(virStringParseYesNo(autoAddress, &usbsrc->autoAddress)); which is equivallent to existing code and also shorter. > >> >>>       } >>>       /* Product can validly be 0, so we need some extra help to >>> determine >>> @@ -8168,8 +8168,8 @@ virDomainHostdevDefParseXMLSubsys(xmlNodePtr >>> node, >>>        * (e.g. <interface>) with type='hostdev') >>>        */ >>>       if ((managed = virXMLPropString(node, "managed")) != NULL) { >>> -        if (STREQ(managed, "yes")) >>> -            def->managed = true; >>> +        if (virStringParseYesNo(managed, &def->managed) < 0) >>> +            def->managed = false; >> >> Here we need to report a proper error because "managed" attribute >> comes from user, therefore risk of an user providing invalid value is >> high compared to the first hunk. But if we want to be consistent we >> should report error in both cases. >> >>>       } >>>       sgio = virXMLPropString(node, "sgio"); >>> @@ -13807,9 +13807,7 @@ >>> virDomainGraphicsListenDefParseXML(virDomainGraphicsListenDefPtr def, >>>       if (autoGenerated && >>>           flags & VIR_DOMAIN_DEF_PARSE_STATUS) { >>> -        if (STREQ(autoGenerated, "yes")) { >>> -            def->autoGenerated = true; >>> -        } else if (STRNEQ(autoGenerated, "no")) { >>> +        if (virStringParseYesNo(autoGenerated, &def->autoGenerated) >>> < 0) { >>>               virReportError(VIR_ERR_XML_ERROR, >>>                              _("Invalid autoGenerated value: %s"), >>>                              autoGenerated); >> >> This one is correct. >> >>> @@ -13939,12 +13937,11 @@ >>> virDomainGraphicsDefParseXMLVNC(virDomainGraphicsDefPtr def, >>>       } >>>       if (autoport) { >>> -        if (STREQ(autoport, "yes")) { >>> -            if (flags & VIR_DOMAIN_DEF_PARSE_INACTIVE) >>> -                def->data.vnc.port = 0; >>> -            def->data.vnc.autoport = true; >>> -        } else { >>> +        if (virStringParseYesNo(autoport, &def->data.vnc.autoport) >>> < 0) { >>>               def->data.vnc.autoport = false; >>> +        } else { >>> +            if (def->data.vnc.autoport && flags & >>> VIR_DOMAIN_DEF_PARSE_INACTIVE) >>> +                def->data.vnc.port = 0; >> >> This doesn't need to go under else branch really. > > right >> >>>           } >>>       } >>> @@ -13958,8 +13955,9 @@ >>> virDomainGraphicsDefParseXMLVNC(virDomainGraphicsDefPtr def, >>>           } >>>       } >>> -    if (websocketGenerated && STREQ(websocketGenerated, "yes")) >>> -        def->data.vnc.websocketGenerated = true; >>> +    if (websocketGenerated && >>> +        virStringParseYesNo(websocketGenerated, >>> &def->data.vnc.websocketGenerated)) >> >> Ooops, you've missed '< 0' comparison. > > virStringParseYesNo return 0 on succeed and -1 on error, and > here is && operation, so, no explicit comparison '< 0'. The comparison is required because even though the function doesn't return any positive value now it might at some point in the future. In libvirt, there's the following semantics for integer return values: < 0 : an error state,   0 : success, > 0 : success, but also something is signalized to the caller There's plenty of examples, but let me pick just one: The retvals for virConfGetValueBool() are defined as follows: -1 on error,  0 if missing,  1 if the value was present And in this code you're adding, you're interested whether the function failed or not. If we ever add another success value (e.g. 1), we don't have to fix all the places where the function is called.

Michal