From: Xavi Hernandez <xhernandez@gmail.com>
Date: Fri, 14 Feb 2025 16:01:07 +0000 (+0100)
Subject: libcephfs_proxy: gracefully handle connection close
X-Git-Tag: v20.3.0~362^2~8
X-Git-Url: http://git.apps.os.sepia.ceph.com/?a=commitdiff_plain;h=5093852ae08981c2e13606124e763055f02737eb;p=ceph.git

libcephfs_proxy: gracefully handle connection close

When a connection is closed while not expecting data, just return a
0-bytes read instead of raising an error.

Signed-off-by: Xavi Hernandez <xhernandez@gmail.com>
---

diff --git a/src/libcephfs_proxy/libcephfsd.c b/src/libcephfs_proxy/libcephfsd.c
index 5c1fc4a44b111..6d04838465cdd 100644
--- a/src/libcephfs_proxy/libcephfsd.c
+++ b/src/libcephfs_proxy/libcephfsd.c
@@ -1627,28 +1627,32 @@ static void serve_binary(proxy_client_t *client)
 		req_iov[1].iov_len = size;
 
 		err = proxy_link_req_recv(client->sd, req_iov, 2);
-		if (err > 0) {
-			if (req.header.op >= LIBCEPHFSD_OP_TOTAL_OPS) {
-				err = send_error(client, -ENOSYS);
-			} else if (libcephfsd_handlers[req.header.op] == NULL) {
-				err = send_error(client, -EOPNOTSUPP);
-			} else {
-				err = libcephfsd_handlers[req.header.op](
-					client, &req, req_iov[1].iov_base,
-					req.header.data_len);
-			}
+		if (err <= 0) {
+			break;
 		}
 
-		if (req_iov[1].iov_base != buffer) {
-			/* Free the buffer if it was temporarily allocated. */
-			proxy_free(req_iov[1].iov_base);
+		if (req.header.op >= LIBCEPHFSD_OP_TOTAL_OPS) {
+			err = send_error(client, -ENOSYS);
+		} else if (libcephfsd_handlers[req.header.op] == NULL) {
+			err = send_error(client, -EOPNOTSUPP);
+		} else {
+			err = libcephfsd_handlers[req.header.op](
+				client, &req, req_iov[1].iov_base,
+				req.header.data_len);
 		}
-
 		if (err < 0) {
 			break;
 		}
+
+		if (req_iov[1].iov_base != buffer) {
+			/* Free the buffer if it was temporarily allocated. */
+			proxy_free(req_iov[1].iov_base);
+		}
 	}
 
+	if (req_iov[1].iov_base != buffer) {
+		proxy_free(req_iov[1].iov_base);
+	}
 	proxy_free(buffer);
 }
 
diff --git a/src/libcephfs_proxy/proxy_link.c b/src/libcephfs_proxy/proxy_link.c
index c1ae0c13d9826..066aa8ef546dd 100644
--- a/src/libcephfs_proxy/proxy_link.c
+++ b/src/libcephfs_proxy/proxy_link.c
@@ -731,7 +731,11 @@ int32_t proxy_link_recv(int32_t sd, struct iovec *iov, int32_t count)
 					 "Failed to receive data");
 		}
 		if (len == 0) {
-			return proxy_log(LOG_ERR, ENODATA, "Partial read");
+			if (total > 0) {
+				return proxy_log(LOG_ERR, EPIPE,
+						 "Partial read");
+			}
+			return 0;
 		}
 		total += len;
 
@@ -773,7 +777,7 @@ int32_t proxy_link_req_recv(int32_t sd, struct iovec *iov, int32_t count)
 	len = iov->iov_len;
 	iov->iov_len = sizeof(proxy_link_req_t);
 	err = proxy_link_recv(sd, iov, 1);
-	if (err < 0) {
+	if (err <= 0) {
 		return err;
 	}
 	total = err;
@@ -813,7 +817,10 @@ int32_t proxy_link_req_recv(int32_t sd, struct iovec *iov, int32_t count)
 	}
 
 	err = proxy_link_recv(sd, iov, count);
-	if (err < 0) {
+	if (err <= 0) {
+		if (err == 0) {
+			return proxy_log(LOG_ERR, EPIPE, "Partial read");
+		}
 		return err;
 	}
 
@@ -843,7 +850,12 @@ int32_t proxy_link_ans_recv(int32_t sd, struct iovec *iov, int32_t count)
 	len = iov->iov_len;
 	iov->iov_len = sizeof(proxy_link_ans_t);
 	err = proxy_link_recv(sd, iov, 1);
-	if (err < 0) {
+	if (err <= 0) {
+		if (err == 0) {
+			return proxy_log(LOG_ERR, EPIPE,
+					 "Connection closed while waiting for "
+					 "an answer");
+		}
 		return err;
 	}
 	total = err;
@@ -876,7 +888,10 @@ int32_t proxy_link_ans_recv(int32_t sd, struct iovec *iov, int32_t count)
 	}
 
 	err = proxy_link_recv(sd, iov, count);
-	if (err < 0) {
+	if (err <= 0) {
+		if (err == 0) {
+			return proxy_log(LOG_ERR, EPIPE, "Partial read");
+		}
 		return err;
 	}