From 591a89c9d2d0b0581742a13cd95a6457810597cf Mon Sep 17 00:00:00 2001
From: Marek Marczykowski <marmarek@invisiblethingslab.com>
Date: Sat, 25 Aug 2012 01:22:00 +0200
Subject: [PATCH] vm/filecopy: support nonblocking fd in read_all

This will be needed to (non blocking) check if data is available on pipe -
especially to receive possible error from the other end (which will be
introduced sometime later).
---
 qubes_rpc/ioall.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/qubes_rpc/ioall.c b/qubes_rpc/ioall.c
index 355b88f..2a81df4 100644
--- a/qubes_rpc/ioall.c
+++ b/qubes_rpc/ioall.c
@@ -75,9 +75,14 @@ int read_all(int fd, void *buf, int size)
 			return 0;
 		}
 		if (ret < 0) {
-			perror_wrapper("read");
+			if (errno != EAGAIN)
+				perror_wrapper("read");
 			return 0;
 		}
+		if (got_read == 0) {
+			// force blocking operation on further reads
+			set_block(fd);
+		}
 		got_read += ret;
 	}
 //      fprintf(stderr, "read %d bytes\n", size);