[Qemu-devel] [PATCH v2 04/15] coroutine-io: handle zero returns from recv

[Paolo Bonzini <pbonzini@redhat.com>]

When the other side is shutdown, read returns zero (writes return EPIPE).
In this case, care must be taken to avoid infinite loops.  This error
was already present in sheepdog.

Cc: MORITA Kazutaka <morita.kazutaka@lab.ntt.co.jp>
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
---
 cutils.c |    8 +++++++-
 1 files changed, 7 insertions(+), 1 deletions(-)

diff --git a/cutils.c b/cutils.c
index b302020..295187f 100644
--- a/cutils.c
+++ b/cutils.c
@@ -501,8 +501,11 @@ static int do_sendv_recvv(int sockfd, struct iovec *iov, int len, int offset,
                 }
                 break;
             }
-            iovlen--, p++;
+            if (rc == 0) {
+                break;
+            }
             ret += rc;
+            iovlen--, p++;
         }
 #endif
     }
@@ -567,6 +570,9 @@ int coroutine_fn qemu_co_sendv(int sockfd, struct iovec *iov,
             }
             break;
         }
+        if (ret == 0) {
+            break;
+        }
         total += ret, len -= ret;
     }
 
-- 
1.7.6