savevm: make qemu_file_put_notify() return errors

[qemu.git] / iov.c

diff --git a/iov.c b/iov.c
index 7cc08f0fe4156392fc34b4c8f196df4ba73db2ab..c6a66f0afe2a584e8af548d1601016ee8b6d513d 100644 (file)
--- a/iov.c
+++ b/iov.c
@@ -26,7 +26,7 @@
 # include <sys/socket.h>
 #endif
 
-size_t iov_from_buf(struct iovec *iov, unsigned int iov_cnt,
+size_t iov_from_buf(const struct iovec *iov, unsigned int iov_cnt,
                     size_t offset, const void *buf, size_t bytes)
 {
     size_t done;
@@ -114,9 +114,9 @@ do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send)
 #else
     /* else send piece-by-piece */
     /*XXX Note: windows has WSASend() and WSARecv() */
-    unsigned i;
-    size_t count = 0;
-    for (i = 0; i < iov_cnt; ++i) {
+    unsigned i = 0;
+    ssize_t ret = 0;
+    while (i < iov_cnt) {
         ssize_t r = do_send
             ? send(sockfd, iov[i].iov_base, iov[i].iov_len, 0)
             : recv(sockfd, iov[i].iov_base, iov[i].iov_len, 0);
@@ -130,12 +130,13 @@ do_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt, bool do_send)
             /* else it is some "other" error,
              * only return if there was no data processed. */
             if (ret == 0) {
-                return -1;
+                ret = -1;
             }
             break;
         }
+        i++;
     }
-    return count;
+    return ret;
 #endif
 }
 
@@ -145,6 +146,13 @@ ssize_t iov_send_recv(int sockfd, struct iovec *iov, unsigned iov_cnt,
 {
     ssize_t ret;
     unsigned si, ei;            /* start and end indexes */
+    if (bytes == 0) {
+        /* Catch the do-nothing case early, as otherwise we will pass an
+         * empty iovec to sendmsg/recvmsg(), and not all implementations
+         * accept this.
+         */
+        return 0;
+    }
 
     /* Find the start position, skipping `offset' bytes:
      * first, skip all full-sized vector elements, */