[dpdk-dev] [PATCH] Unlink existing unused sockets at start up

[Zhihong Wang <zhihong.wang@intel.com>]

This patch unlinks existing unused sockets (which cause new bindings to fail, e.g. vHost PMD) to ensure smooth startup.
In a lot of cases DPDK applications are terminated abnormally without proper resource release. Therefore, DPDK libs should be able to deal with unclean boot environment.

Signed-off-by: Zhihong Wang <zhihong.wang@intel.com>
---
 lib/librte_vhost/vhost_user/vhost-net-user.c | 28 ++++++++++++++++++++++++----
 1 file changed, 24 insertions(+), 4 deletions(-)

diff --git a/lib/librte_vhost/vhost_user/vhost-net-user.c b/lib/librte_vhost/vhost_user/vhost-net-user.c
index 8b7a448..eac0721 100644
--- a/lib/librte_vhost/vhost_user/vhost-net-user.c
+++ b/lib/librte_vhost/vhost_user/vhost-net-user.c
@@ -120,18 +120,38 @@ uds_socket(const char *path)
 	sockfd = socket(AF_UNIX, SOCK_STREAM, 0);
 	if (sockfd < 0)
 		return -1;
-	RTE_LOG(INFO, VHOST_CONFIG, "socket created, fd:%d\n", sockfd);
+	RTE_LOG(INFO, VHOST_CONFIG, "socket created, fd: %d\n", sockfd);
 
 	memset(&un, 0, sizeof(un));
 	un.sun_family = AF_UNIX;
 	snprintf(un.sun_path, sizeof(un.sun_path), "%s", path);
 	ret = bind(sockfd, (struct sockaddr *)&un, sizeof(un));
 	if (ret == -1) {
-		RTE_LOG(ERR, VHOST_CONFIG, "fail to bind fd:%d, remove file:%s and try again.\n",
+		RTE_LOG(ERR, VHOST_CONFIG,
+			"bind fd: %d to file: %s failed, checking socket...\n",
 			sockfd, path);
-		goto err;
+		ret = connect(sockfd, (struct sockaddr *)&un, sizeof(un));
+		if (ret == -1) {
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"socket: %s is inactive, rebinding after unlink...\n", path);
+			unlink(path);
+			ret = bind(sockfd, (struct sockaddr *)&un, sizeof(un));
+			if (ret == -1) {
+				RTE_LOG(ERR, VHOST_CONFIG,
+					"bind fd: %d to file: %s failed even after unlink\n",
+					sockfd, path);
+				goto err;
+			}
+		} else {
+			RTE_LOG(INFO, VHOST_CONFIG,
+				"socket: %s is alive, remove it and try again\n", path);
+			RTE_LOG(ERR, VHOST_CONFIG,
+				"bind fd: %d to file: %s failed\n", sockfd, path);
+			goto err;
+		}
 	}
-	RTE_LOG(INFO, VHOST_CONFIG, "bind to %s\n", path);
+	RTE_LOG(INFO, VHOST_CONFIG,
+		"bind fd: %d to file: %s successful\n", sockfd, path);
 
 	ret = listen(sockfd, MAX_VIRTIO_BACKLOG);
 	if (ret == -1)
-- 
2.5.0