[libvirt] [PATCH v1 07/32] util: netdev: use VIR_AUTOPTR for aggregate types

Erik Skultety eskultet at redhat.com
Fri Aug 3 09:19:01 UTC 2018


On Sat, Jul 28, 2018 at 11:31:22PM +0530, Sukrit Bhatnagar wrote:
> By making use of GNU C's cleanup attribute handled by the
> VIR_AUTOPTR macro for declaring aggregate pointer variables,
> majority of the calls to *Free functions can be dropped, which
> in turn leads to getting rid of most of our cleanup sections.
>
> Signed-off-by: Sukrit Bhatnagar <skrtbhtngr at gmail.com>
> ---
>  src/util/virnetdev.c | 129 ++++++++++++++++++++++-----------------------------
>  1 file changed, 55 insertions(+), 74 deletions(-)
>
> diff --git a/src/util/virnetdev.c b/src/util/virnetdev.c
> index 7653f8b..c5871b4 100644
> --- a/src/util/virnetdev.c
> +++ b/src/util/virnetdev.c
> @@ -1855,16 +1855,15 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>                         const char *stateDir,
>                         bool saveVlan)
>  {
> -    int ret = -1;
>      const char *pfDevName = NULL;
>      VIR_AUTOFREE(char *) pfDevOrig = NULL;
>      VIR_AUTOFREE(char *) vfDevOrig = NULL;
>      VIR_AUTOFREE(char *) filePath = NULL;
>      VIR_AUTOFREE(char *) fileStr = NULL;
> +    VIR_AUTOPTR(virJSONValue) configJSON = NULL;
>      virMacAddr oldMAC;
>      char MACStr[VIR_MAC_STRING_BUFLEN];
>      int oldVlanTag = -1;
> -    virJSONValuePtr configJSON = NULL;
>
>      if (vf >= 0) {
>          /* linkdev is the PF */
> @@ -1872,7 +1871,7 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>
>          /* linkdev should get the VF's netdev name (or NULL if none) */
>          if (virNetDevPFGetVF(pfDevName, vf, &vfDevOrig) < 0)
> -            goto cleanup;
> +            return -1;
>
>          linkdev = vfDevOrig;
>          saveVlan = true;
> @@ -1884,12 +1883,12 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>           */
>
>          if (virNetDevGetPhysicalFunction(linkdev, &pfDevOrig) < 0)
> -            goto cleanup;
> +            return -1;
>
>          pfDevName = pfDevOrig;
>
>          if (virNetDevGetVirtualFunctionIndex(pfDevName, linkdev, &vf) < 0)
> -            goto cleanup;
> +            return -1;
>      }
>
>      if (pfDevName) {
> @@ -1907,7 +1906,7 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>           * explicitly enable the PF in the host system network config.
>           */
>          if (virNetDevGetOnline(pfDevName, &pfIsOnline) < 0)
> -            goto cleanup;
> +            return -1;
>
>          if (!pfIsOnline) {
>              virReportError(VIR_ERR_INTERNAL_ERROR,
> @@ -1916,12 +1915,12 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>                               "change host network config to put the "
>                               "PF online."),
>                             vf, pfDevName);
> -            goto cleanup;
> +            return -1;
>          }
>      }
>
>      if (!(configJSON = virJSONValueNewObject()))
> -        goto cleanup;
> +        return -1;
>
>      /* if there is a PF, it's now in pfDevName, and linkdev is either
>       * the VF's name, or NULL (if the VF isn't bound to a net driver
> @@ -1930,11 +1929,11 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>
>      if (pfDevName && saveVlan) {
>          if (virAsprintf(&filePath, "%s/%s_vf%d", stateDir, pfDevName, vf) < 0)
> -            goto cleanup;
> +            return -1;
>
>          /* get admin MAC and vlan tag */
>          if (virNetDevGetVfConfig(pfDevName, vf, &oldMAC, &oldVlanTag) < 0)
> -            goto cleanup;
> +            return -1;
>
>          if (virJSONValueObjectAppendString(configJSON,
>                                             VIR_NETDEV_KEYNAME_ADMIN_MAC,
> @@ -1942,39 +1941,36 @@ virNetDevSaveNetConfig(const char *linkdev, int vf,
>              virJSONValueObjectAppendNumberInt(configJSON,
>                                                VIR_NETDEV_KEYNAME_VLAN_TAG,
>                                                oldVlanTag) < 0) {
> -            goto cleanup;
> +            return -1;
>          }
>
>      } else {
>          if (virAsprintf(&filePath, "%s/%s", stateDir, linkdev) < 0)
> -            goto cleanup;
> +            return -1;
>      }
>
>      if (linkdev) {
>          if (virNetDevGetMAC(linkdev, &oldMAC) < 0)
> -            goto cleanup;
> +            return -1;
>
>          /* for interfaces with no pfDevName (i.e. not a VF, this will
>           * be the only value in the file.
>           */
>          if (virJSONValueObjectAppendString(configJSON, VIR_NETDEV_KEYNAME_MAC,
>                                             virMacAddrFormat(&oldMAC, MACStr)) < 0)
> -           goto cleanup;
> +            return -1;
>      }
>
>      if (!(fileStr = virJSONValueToString(configJSON, true)))
> -        goto cleanup;
> +        return -1;
>
>      if (virFileWriteStr(filePath, fileStr, O_CREAT|O_TRUNC|O_WRONLY) < 0) {
>          virReportSystemError(errno, _("Unable to preserve mac/vlan tag "
>                                        "for device = %s, vf = %d"), linkdev, vf);
> -        goto cleanup;
> +        return -1;
>      }
>
> -    ret = 0;
> - cleanup:
> -    virJSONValueFree(configJSON);
> -    return ret;
> +    return 0;
>  }
>
>
> @@ -2012,7 +2008,10 @@ virNetDevReadNetConfig(const char *linkdev, int vf,
>      VIR_AUTOFREE(char *) vfDevOrig = NULL;
>      VIR_AUTOFREE(char *) filePath = NULL;
>      VIR_AUTOFREE(char *) fileStr = NULL;
> -    virJSONValuePtr configJSON = NULL;
> +    VIR_AUTOPTR(virJSONValue) configJSON = NULL;
> +    VIR_AUTOPTR(virMacAddr) tempAdminMAC = NULL;
> +    VIR_AUTOPTR(virMacAddr) tempMAC = NULL;
> +    VIR_AUTOPTR(virNetDevVlan) tempVlan = NULL;
>      const char *MACStr = NULL;
>      const char *adminMACStr = NULL;
>      int vlanTag = -1;
> @@ -2176,15 +2175,12 @@ virNetDevReadNetConfig(const char *linkdev, int vf,
>      /* we won't need the file again */
>      ignore_value(unlink(filePath));
>
> -    ret = 0;
> +    return 0;
>   cleanup:
> -    if (ret < 0) {
> -        VIR_FREE(*adminMAC);
> -        VIR_FREE(*MAC);
> -        VIR_FREE(*vlan);
> -    }
> +    VIR_STEAL_PTR(tempAdminMAC, *adminMAC);
> +    VIR_STEAL_PTR(tempMAC, *MAC);
> +    VIR_STEAL_PTR(tempVlan, *vlan);

You'd want the opposite VIR_STEAL_PTR direction, so that the cleanup label
could be dropped completely.

>
> -    virJSONValueFree(configJSON);
>      return ret;
>  }
>
> @@ -2214,13 +2210,12 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>                        const virMacAddr *MAC,
>                        bool setVlan)
>  {
> -    int ret = -1;
>      char MACStr[VIR_MAC_STRING_BUFLEN];
>      const char *pfDevName = NULL;
>      VIR_AUTOFREE(char *) pfDevOrig = NULL;
>      VIR_AUTOFREE(char *) vfDevOrig = NULL;
> +    VIR_AUTOPTR(virPCIDevice) vfPCIDevice = NULL;
>      int vlanTag = -1;
> -    virPCIDevicePtr vfPCIDevice = NULL;
>
>      if (vf >= 0) {
>          /* linkdev is the PF */
> @@ -2228,7 +2223,7 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>
>          /* linkdev should get the VF's netdev name (or NULL if none) */
>          if (virNetDevPFGetVF(pfDevName, vf, &vfDevOrig) < 0)
> -            goto cleanup;
> +            return -1;
>
>          linkdev = vfDevOrig;
>
> @@ -2239,12 +2234,12 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>           */
>
>          if (virNetDevGetPhysicalFunction(linkdev, &pfDevOrig) < 0)
> -            goto cleanup;
> +            return -1;
>
>          pfDevName = pfDevOrig;
>
>          if (virNetDevGetVirtualFunctionIndex(pfDevName, linkdev, &vf) < 0)
> -            goto cleanup;
> +            return -1;
>      }
>
>
> @@ -2256,14 +2251,14 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>              virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>                             _("admin MAC can only be set for SR-IOV VFs, but "
>                               "%s is not a VF"), linkdev);
> -            goto cleanup;
> +            return -1;
>          }
>
>          if (vlan) {
>              virReportError(VIR_ERR_CONFIG_UNSUPPORTED,
>                             _("vlan can only be set for SR-IOV VFs, but "
>                               "%s is not a VF"), linkdev);
> -            goto cleanup;
> +            return -1;
>          }
>
>      } else {
> @@ -2272,14 +2267,14 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>                  virReportError(VIR_ERR_CONFIG_UNSUPPORTED, "%s",
>                                 _("vlan trunking is not supported "
>                                   "by SR-IOV network devices"));
> -                goto cleanup;
> +                return -1;
>              }
>
>              if (!setVlan) {
>                  virReportError(VIR_ERR_INTERNAL_ERROR, "%s",
>                                 _("vlan tag set for interface %s but "
>                                   "caller requested it not be set"));
> -                goto cleanup;
> +                return -1;
>              }
>
>              vlanTag = vlan->tag[0];
> @@ -2297,7 +2292,7 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>                             _("VF %d of PF '%s' is not bound to a net driver, "
>                               "so its MAC address cannot be set to %s"),
>                             vf, pfDevName, virMacAddrFormat(MAC, MACStr));
> -            goto cleanup;
> +            return -1;
>          }
>
>          setMACrc = virNetDevSetMACInternal(linkdev, MAC, !!pfDevOrig);
> @@ -2308,7 +2303,7 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>              /* if pfDevOrig == NULL, this isn't a VF, so we've failed */
>              if (!pfDevOrig ||
>                  (errno != EADDRNOTAVAIL && errno != EPERM))
> -                goto cleanup;
> +                return -1;
>
>              /* Otherwise this is a VF, and virNetDevSetMAC failed with
>               * EADDRNOTAVAIL/EPERM, which could be due to the
> @@ -2322,18 +2317,18 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>
>              if (virNetDevSetVfConfig(pfDevName, vf,
>                                       MAC, vlanTag, &allowRetry) < 0) {
> -                goto cleanup;
> +                return -1;
>              }
>
>              /* admin MAC is set, now we need to construct a virPCIDevice
>               * object so we can call virPCIDeviceRebind()
>               */
>              if (!(vfPCIDevice = virNetDevGetPCIDevice(linkdev)))
> -                goto cleanup;
> +                return -1;
>
>              /* Rebind the device. This should set the proper MAC address */
>              if (virPCIDeviceRebind(vfPCIDevice) < 0)
> -                goto cleanup;
> +                return -1;
>
>              /* Wait until virNetDevGetIndex for the VF netdev returns success.
>               * This indicates that the device is ready to be used. If we don't
> @@ -2385,20 +2380,17 @@ virNetDevSetNetConfig(const char *linkdev, int vf,
>               * with the "locally administered" bit set.
>               */
>              if (!allowRetry)
> -                goto cleanup;
> +                return -1;
>
>              allowRetry = false;
>              if (virNetDevSetVfConfig(pfDevName, vf,
>                                       &altZeroMAC, vlanTag, &allowRetry) < 0) {
> -                goto cleanup;
> +                return -1;
>              }
>          }
>      }
>
> -    ret = 0;
> - cleanup:
> -    virPCIDeviceFree(vfPCIDevice);
> -    return ret;
> +    return 0;
>  }
>
>
> @@ -2873,30 +2865,31 @@ virNetDevRxFilterFree(virNetDevRxFilterPtr filter)
>  int virNetDevGetRxFilter(const char *ifname,
>                           virNetDevRxFilterPtr *filter)
>  {
> -    int ret = -1;
>      bool receive = false;
> -    virNetDevRxFilterPtr fil = virNetDevRxFilterNew();
> +    VIR_AUTOPTR(virNetDevRxFilter) fil = virNetDevRxFilterNew();
> +
> +    *filter = NULL;
>
>      if (!fil)
> -        goto cleanup;
> +        return -1;
>
>      if (virNetDevGetMAC(ifname, &fil->mac))
> -        goto cleanup;
> +        return -1;
>
>      if (virNetDevGetMulticastTable(ifname, fil))
> -        goto cleanup;
> +        return -1;
>
>      if (virNetDevGetPromiscuous(ifname, &fil->promiscuous))
> -        goto cleanup;
> +        return -1;
>
>      if (virNetDevGetRcvAllMulti(ifname, &receive))
> -        goto cleanup;
> +        return -1;
>
>      if (receive) {
>          fil->multicast.mode = VIR_NETDEV_RX_FILTER_MODE_ALL;
>      } else {
>          if (virNetDevGetRcvMulti(ifname, &receive))
> -            goto cleanup;
> +            return -1;
>
>          if (receive)
>              fil->multicast.mode = VIR_NETDEV_RX_FILTER_MODE_NORMAL;
> @@ -2904,15 +2897,8 @@ int virNetDevGetRxFilter(const char *ifname,
>              fil->multicast.mode = VIR_NETDEV_RX_FILTER_MODE_NONE;
>      }
>
> -    ret = 0;
> - cleanup:
> -    if (ret < 0) {
> -        virNetDevRxFilterFree(fil);
> -        fil = NULL;
> -    }
> -
> -    *filter = fil;
> -    return ret;
> +    VIR_STEAL_PTR(*filter, fil);

Yep, this is the correct usage of VIR_STEAL_PTR.

> +    return 0;
>  }
>
>  #if defined(SIOCETHTOOL) && defined(HAVE_STRUCT_IFREQ)
> @@ -3185,12 +3171,12 @@ virNetDevSwitchdevFeature(const char *ifname,
>  {
>      struct nl_msg *nl_msg = NULL;
>      VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
> +    VIR_AUTOFREE(char *) pfname = NULL;

^This code movement should be dropped and a we should follow a different scheme
separating the VIR_AUTO* variables. Otherwise looks fine.

Erik




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