linux sendfile: exit with an error if the file gets smaller in the middle of

a request.

With this patch, a faked up shrinking file, and LogLevel info, the log contains:
[Fri May 17 13:34:45 2002] [info] (20514)End of file found: core_output_filter:
writing data to the network

...and the assert in sendfile_it_all doesn't hit.

Is APR_EOF appropriate?  beats me; it gets the job done.  If you think of
something better, please speak up soon because I plan on doing FreeBSD next.


git-svn-id: https://svn.apache.org/repos/asf/apr/apr/trunk@63408 13f79535-47bb-0310-9956-ffa450edef68

1 files changed, 19 insertions, 7 deletions

diff --git a/network_io/unix/sendrecv.c b/network_io/unix/sendrecv.c
index f9229c8fe..da54464d4 100644
--- a/network_io/unix/sendrecv.c
+++ b/network_io/unix/sendrecv.c
@@ -390,16 +390,28 @@ do_select:
 
     nbytes += rv;
 
-    /* If this was a partial write, return now with the partial byte count; 
-     * this is a non-blocking socket.
-     */
-
     if (rv < *len) {
         *len = nbytes;
-        if (sock->timeout) {
-            sock->netmask |= APR_INCOMPLETE_WRITE;
+        arv = apr_setsocketopt(sock, APR_TCP_NOPUSH, 0);
+        if (rv > 0) {
+                
+            /* If this was a partial write, return now with the 
+             * partial byte count;  this is a non-blocking socket.
+             */
+
+            if (sock->timeout) {
+                sock->netmask |= APR_INCOMPLETE_WRITE;
+            }
+            return arv;
+        }
+        else {
+            /* If the file got smaller mid-request, eventually the offset
+             * becomes equal to the new file size and the kernel returns 0.  
+             * Make this an error so the caller knows to log something and
+             * exit.
+             */
+            return APR_EOF;
         }
-        return apr_setsocketopt(sock, APR_TCP_NOPUSH, 0);
     }
 
     /* Now write the footers */