[kexec-tools] dracut-kdump.sh: Issue a sync after saving vmcore-dmesg.txt

[WANG Chao]

commit 7f2717aa0ad98c01a32a59735f0579498fee84ec
Author: Vivek Goyal <vgoyal at redhat.com>
Date:   Thu Jul 24 13:43:48 2014 -0400

    dracut-kdump.sh: Issue a sync after saving vmcore-dmesg.txt
    
    Recently somebody reported an issue where vmcore-dmesg.txt was saved
    successfully but later saving vmcore failed to due to lack of space on disk.
    System rebooted but after reboot there was nothing on disk. Not even
    vmcore-dmesg.txt.
    
    Issue a sync after saving vmcore-dmesg.txt to solve this issue.
    
    I think this is happening because we are doing "reboot -f" instead of going
    through systemd reboot path. Anyway, doing a sync now should take care of
    this.
    
    Signed-off-by: Vivek Goyal <vgoyal at redhat.com>
    Acked-by: WANG Chao <chaowang at redhat.com>

 dracut-kdump.sh |    5 +++++
 1 files changed, 5 insertions(+), 0 deletions(-)
---
diff --git a/dracut-kdump.sh b/dracut-kdump.sh
index 9958317..e6faf9c 100755
--- a/dracut-kdump.sh
+++ b/dracut-kdump.sh
@@ -179,6 +179,11 @@ save_vmcore_dmesg_fs() {
     _exitcode=$?
     if [ $_exitcode -eq 0 ]; then
         mv ${_path}/vmcore-dmesg-incomplete.txt ${_path}/vmcore-dmesg.txt
+
+	# Make sure file is on disk. There have been instances where later
+	# saving vmcore failed and system rebooted without sync and there
+	# was no vmcore-dmesg.txt available.
+        sync
         echo "kdump: saving vmcore-dmesg.txt complete"
     else
         echo "kdump: saving vmcore-dmesg.txt failed"