From 86f254850d4a80bfa0e7ea53766b505c654660bc Mon Sep 17 00:00:00 2001
From: dave <dprotaso@gmail.com>
Date: Wed, 15 Nov 2017 21:26:52 -0500
Subject: [PATCH] After partitioning we now retry the stat prior to formatting

When waiting for devices to refresh a stat can fail with the
error message 'stat: /dev/vda1: stat: no such file or directory'.

This was observered with empty raw disks (*.img) that was being
created by the moby/hyperkit go library.

This commit restores the previous logic of refreshing with mdev
instead of returning an error.

Signed-off-by: dave protasowski <dprotaso@gmail.com>
---
 pkg/format/format.go | 20 +++++++++++++-------
 1 file changed, 13 insertions(+), 7 deletions(-)

diff --git a/pkg/format/format.go b/pkg/format/format.go
index c967ecb22..713975555 100644
--- a/pkg/format/format.go
+++ b/pkg/format/format.go
@@ -100,13 +100,15 @@ func refreshDevicesAndWaitFor(awaitedDevice string) error {
 	exec.Command("mdev", "-s").Run()
 
 	// wait for device
-	var done bool
+	var (
+		done bool
+		err  error
+		stat os.FileInfo
+	)
+
 	for i := 0; i < timeout; i++ {
-		stat, err := os.Stat(awaitedDevice)
-		if err != nil {
-			return err
-		}
-		if isBlockDevice(&stat) {
+		stat, err = os.Stat(awaitedDevice)
+		if err == nil && isBlockDevice(&stat) {
 			done = true
 			break
 		}
@@ -114,7 +116,11 @@ func refreshDevicesAndWaitFor(awaitedDevice string) error {
 		exec.Command("mdev", "-s").Run()
 	}
 	if !done {
-		return fmt.Errorf("Error waiting for device %s", awaitedDevice)
+		var statMsg string
+		if err != nil {
+			statMsg = fmt.Sprintf(" - stat returned: %v", err)
+		}
+		return fmt.Errorf("Failed to find block device %s%s", awaitedDevice, statMsg)
 	}
 	// even after the device appears we still have a race
 	time.Sleep(1 * time.Second)