[libvirt] [PATCH v7 12/19] utils: Mark inpipe as non-blocking

[Stefan Berger]

Mark a virCommand's inpipe (write-end of pipe) as non-blocking so that it
will never block when we were to try to write too many bytes to it while
it doesn't have the capacity to hold them.

Signed-off-by: Stefan Berger <stefanb at linux.ibm.com>
Reviewed-by: Daniel P. Berrangé <berrange at redhat.com>
---
 src/util/vircommand.c | 13 +++++++++++++
 1 file changed, 13 insertions(+)

diff --git a/src/util/vircommand.c b/src/util/vircommand.c
index f29b679b77..50e14fd8be 100644
--- a/src/util/vircommand.c
+++ b/src/util/vircommand.c
@@ -2537,6 +2537,19 @@ virCommandRunAsync(virCommandPtr cmd, pid_t *pid)
         }
         cmd->infd = infd[0];
         cmd->inpipe = infd[1];
+#if defined (F_SETFL)
+        if (fcntl(cmd->inpipe, F_SETFL, O_NONBLOCK) < 0) {
+            virReportSystemError(errno, "%s",
+                                 _("fcntl failed to set O_NONBLOCK"));
+            cmd->has_error = -1;
+            ret = -1;
+            goto cleanup;
+        }
+#else /* !defined(F_SETFL) */
+        cmd->has_error = ENOTSUP;
+        ret = -1;
+        goto cleanup;
+#endif
     } else if ((cmd->inbuf && cmd->infd == -1) ||
                (cmd->outbuf && cmd->outfdptr != &cmd->outfd) ||
                (cmd->errbuf && cmd->errfdptr != &cmd->errfd)) {
-- 
2.20.1