[libvirt] [PATCH v3 03/11] util: netlink: use VIR_AUTOFREE instead of VIR_FREE for scalar types

[Erik Skultety]

On Thu, Aug 09, 2018 at 09:42:11AM +0530, Sukrit Bhatnagar wrote:
> By making use of GNU C's cleanup attribute handled by the
> VIR_AUTOFREE macro for declaring scalar variables, majority
> of the VIR_FREE calls 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/virnetlink.c | 43 ++++++++++++++++++++-----------------------
>  1 file changed, 20 insertions(+), 23 deletions(-)
>
> diff --git a/src/util/virnetlink.c b/src/util/virnetlink.c
> index ecf62c9..fcdc09d 100644
> --- a/src/util/virnetlink.c
> +++ b/src/util/virnetlink.c
> @@ -342,10 +342,8 @@ virNetlinkDumpCommand(struct nl_msg *nl_msg,
>                        unsigned int protocol, unsigned int groups,
>                        void *opaque)
>  {
> -    int ret = -1;
>      bool end = false;
>      int len = 0;
> -    struct nlmsghdr *resp = NULL;
>      struct nlmsghdr *msg = NULL;
>
>      struct sockaddr_nl nladdr = {
> @@ -357,9 +355,11 @@ virNetlinkDumpCommand(struct nl_msg *nl_msg,
>
>      if (!(nlhandle = virNetlinkSendRequest(nl_msg, src_pid, nladdr,
>                                             protocol, groups)))
> -        goto cleanup;
> +        return -1;
>
>      while (!end) {
> +        VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
> +
>          len = nl_recv(nlhandle, &nladdr, (unsigned char **)&resp, NULL);
>          VIR_WARNINGS_NO_CAST_ALIGN
>          for (msg = resp; NLMSG_OK(msg, len); msg = NLMSG_NEXT(msg, len)) {
> @@ -368,19 +368,14 @@ virNetlinkDumpCommand(struct nl_msg *nl_msg,
>                  end = true;
>
>              if (virNetlinkGetErrorCode(msg, len) < 0)
> -                goto cleanup;
> +                return -1;
>
>              if (callback(msg, opaque) < 0)
> -                goto cleanup;
> +                return -1;
>          }
> -        VIR_FREE(resp);
>      }
>
> -    ret = 0;
> -
> - cleanup:
> -    VIR_FREE(resp);
> -    return ret;
> +    return 0;
>  }
>
>  /**
> @@ -408,7 +403,6 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
>                     uint32_t src_pid, uint32_t dst_pid)
>  {
>      int rc = -1;
> -    struct nlmsghdr *resp = NULL;
>      struct nlmsgerr *err;
>      struct ifinfomsg ifinfo = {
>          .ifi_family = AF_UNSPEC,
> @@ -416,6 +410,9 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
>      };
>      unsigned int recvbuflen;
>      struct nl_msg *nl_msg;
> +    VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
> +
> +    *nlData = NULL;

unnecessary...

>
>      if (ifname && ifindex <= 0 && virNetDevGetIndex(ifname, &ifindex) < 0)
>          return -1;
> @@ -483,12 +480,12 @@ virNetlinkDumpLink(const char *ifname, int ifindex,
>      default:
>          goto malformed_resp;
>      }
> +
> +    VIR_STEAL_PTR(*nlData, resp);
>      rc = 0;
> +
>   cleanup:
>      nlmsg_free(nl_msg);
> -    if (rc < 0)
> -       VIR_FREE(resp);
> -    *nlData = resp;
>      return rc;
>
>   malformed_resp:
> @@ -522,11 +519,11 @@ int
>  virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback)
>  {
>      int rc = -1;
> -    struct nlmsghdr *resp = NULL;
>      struct nlmsgerr *err;
>      struct ifinfomsg ifinfo = { .ifi_family = AF_UNSPEC };
>      unsigned int recvbuflen;
>      struct nl_msg *nl_msg;
> +    VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
>
>      nl_msg = nlmsg_alloc_simple(RTM_DELLINK,
>                                  NLM_F_REQUEST | NLM_F_CREATE | NLM_F_EXCL);
> @@ -577,7 +574,6 @@ virNetlinkDelLink(const char *ifname, virNetlinkDelLinkFallback fallback)
>      rc = 0;
>   cleanup:
>      nlmsg_free(nl_msg);
> -    VIR_FREE(resp);
>      return rc;
>
>   malformed_resp:
> @@ -610,13 +606,15 @@ int
>  virNetlinkGetNeighbor(void **nlData, uint32_t src_pid, uint32_t dst_pid)
>  {
>      int rc = -1;
> -    struct nlmsghdr *resp = NULL;
>      struct nlmsgerr *err;
>      struct ndmsg ndinfo = {
>          .ndm_family = AF_UNSPEC,
>      };
>      unsigned int recvbuflen;
>      struct nl_msg *nl_msg;
> +    VIR_AUTOFREE(struct nlmsghdr *) resp = NULL;
> +
> +    *nlData = NULL;

unnecessary...

The rest is fine, I'll adjust before merging.
Reviewed-by: Erik Skultety <eskultet at redhat.com>

>
>      nl_msg = nlmsg_alloc_simple(RTM_GETNEIGH, NLM_F_DUMP | NLM_F_REQUEST);
>      if (!nl_msg) {
> @@ -654,13 +652,12 @@ virNetlinkGetNeighbor(void **nlData, uint32_t src_pid, uint32_t dst_pid)
>      default:
>          goto malformed_resp;
>      }
> +
> +    VIR_STEAL_PTR(*nlData, resp);
>      rc = recvbuflen;
>
>   cleanup:
>      nlmsg_free(nl_msg);
> -    if (rc < 0)
> -       VIR_FREE(resp);
> -    *nlData = resp;
>      return rc;
>
>   malformed_resp:
> @@ -766,12 +763,12 @@ virNetlinkEventCallback(int watch,
>                          void *opaque)
>  {
>      virNetlinkEventSrvPrivatePtr srv = opaque;
> -    struct nlmsghdr *msg;
>      struct sockaddr_nl peer;
>      struct ucred *creds = NULL;
>      size_t i;
>      int length;
>      bool handled = false;
> +    VIR_AUTOFREE(struct nlmsghdr *) msg = NULL;
>
>      length = nl_recv(srv->netlinknh, &peer,
>                       (unsigned char **)&msg, &creds);
> @@ -801,7 +798,7 @@ virNetlinkEventCallback(int watch,
>
>      if (!handled)
>          VIR_DEBUG("event not handled.");
> -    VIR_FREE(msg);
> +
>      virNetlinkEventServerUnlock(srv);
>  }
>
> --
> 1.8.3.1
>
> --
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