erts: Fix fd leak when an active socket is closed remotely

Fixes #4540

1 files changed, 17 insertions, 10 deletions

diff --git a/erts/emulator/drivers/common/inet_drv.c b/erts/emulator/drivers/common/inet_drv.c
index b71ce0389d..e4fc0d1a6b 100644
--- a/erts/emulator/drivers/common/inet_drv.c
+++ b/erts/emulator/drivers/common/inet_drv.c
@@ -9922,6 +9922,15 @@ static void tcp_inet_stop(ErlDrvData e)
     tcp_close_check(desc);
     tcp_clear_input(desc);
 
+#ifdef HAVE_SENDFILE
+    if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
+        desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
+        close(desc->sendfile.dup_file_fd);
+        DEBUGF(("tcp_inet_stop(%p): SENDFILE dup closed %d\r\n",
+                desc->inet.port, desc->sendfile.dup_file_fd));
+    }
+#endif
+
     DEBUGF(("tcp_inet_stop(%ld) }\r\n", (long)desc->inet.port));
     inet_stop(INETP(desc));
 }
@@ -9937,12 +9946,6 @@ static void tcp_inet_stop(ErlDrvData e)
  * will be freed through tcp_inet_stop later on. */
 static void tcp_desc_close(tcp_descriptor* desc)
 {
-#ifdef HAVE_SENDFILE
-    if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
-        desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
-        close(desc->sendfile.dup_file_fd);
-    }
-#endif
 
     tcp_clear_input(desc);
     tcp_clear_output(desc);
@@ -10315,6 +10318,9 @@ static ErlDrvSSizeT tcp_inet_ctl(ErlDrvData e, unsigned int cmd,
 
         desc->sendfile.dup_file_fd = dup(raw_file_fd);
 
+        DEBUGF(("tcp_inet_ctl(%p): SENDFILE dup %d\r\n",
+                desc->inet.port, desc->sendfile.dup_file_fd));
+
         if(desc->sendfile.dup_file_fd == -1) {
             return ctl_error(errno, rbuf, rsize);
         }
@@ -10492,11 +10498,9 @@ static void tcp_inet_flush(ErlDrvData e)
 
 #ifdef HAVE_SENDFILE
     /* The old file driver aborted when it was stopped during sendfile, so
-     * we'll clear the flag and discard all output. */
+     * we'll clear the flag and discard all output. It is the job of
+     * tcp_inet_stop to close the extra sendfile fd. */
     if(desc->tcp_add_flags & TCP_ADDF_SENDFILE) {
-        desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
-        close(desc->sendfile.dup_file_fd);
-
         discard_output = 1;
     }
 #endif
@@ -11634,6 +11638,9 @@ static int tcp_sendfile_completed(tcp_descriptor* desc) {
     desc->tcp_add_flags &= ~TCP_ADDF_SENDFILE;
     close(desc->sendfile.dup_file_fd);
 
+    DEBUGF(("tcp_sendfile_completed(%p): SENDFILE dup closed %d\r\n",
+            desc->inet.port, desc->sendfile.dup_file_fd));
+
     /* While we flushed the output queue prior to sending the file, we've
      * deferred clearing busy status until now as there's no point in doing so
      * while we still have a file to send.