From 8cbee49ed7348e9b2b708d75c8ff8941032cb488 Mon Sep 17 00:00:00 2001
From: Eric Blake <eblake@redhat.com>
Date: Fri, 27 Oct 2017 12:40:30 +0200
Subject: [PATCH] nbd/server: Simplify nbd_negotiate_options loop

Instead of making each caller check whether a transmission error
occurred, we can sink a common error check to the end of the loop.

Signed-off-by: Eric Blake <eblake@redhat.com>
Message-Id: <20171027104037.8319-6-eblake@redhat.com>
[eblake: squash in compiler warning fix]
Reviewed-by: Vladimir Sementsov-Ogievskiy <vsementsov@virtuozzo.com>
---
 nbd/server.c | 19 ++++---------------
 1 file changed, 4 insertions(+), 15 deletions(-)

diff --git a/nbd/server.c b/nbd/server.c
index 05ff7470d5..2f03059b4c 100644
--- a/nbd/server.c
+++ b/nbd/server.c
@@ -678,6 +678,7 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                 if (!tioc) {
                     return -EIO;
                 }
+                ret = 0;
                 object_unref(OBJECT(client->ioc));
                 client->ioc = QIO_CHANNEL(tioc);
                 break;
@@ -698,9 +699,6 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                                                  "Option 0x%" PRIx32
                                                  "not permitted before TLS",
                                                  option);
-                if (ret < 0) {
-                    return ret;
-                }
                 /* Let the client keep trying, unless they asked to
                  * quit. In this mode, we've already sent an error, so
                  * we can't ack the abort.  */
@@ -713,9 +711,6 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
             switch (option) {
             case NBD_OPT_LIST:
                 ret = nbd_negotiate_handle_list(client, length, errp);
-                if (ret < 0) {
-                    return ret;
-                }
                 break;
 
             case NBD_OPT_ABORT:
@@ -738,9 +733,6 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                     assert(option == NBD_OPT_GO);
                     return 0;
                 }
-                if (ret) {
-                    return ret;
-                }
                 break;
 
             case NBD_OPT_STARTTLS:
@@ -758,9 +750,6 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                                                      option, errp,
                                                      "TLS not configured");
                 }
-                if (ret < 0) {
-                    return ret;
-                }
                 break;
             default:
                 if (nbd_drop(client->ioc, length, errp) < 0) {
@@ -772,9 +761,6 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                                                  "Unsupported option 0x%"
                                                  PRIx32 " (%s)", option,
                                                  nbd_opt_lookup(option));
-                if (ret < 0) {
-                    return ret;
-                }
                 break;
             }
         } else {
@@ -794,6 +780,9 @@ static int nbd_negotiate_options(NBDClient *client, uint16_t myflags,
                 return -EINVAL;
             }
         }
+        if (ret < 0) {
+            return ret;
+        }
     }
 }