shutdown: pamper RAID devices with external metadata

Ensure that these devices (likely FakeRAID) are clean before stopping,
to avoid leaving them in the dirty state and forcing a rebuild.

Signed-off-by: Dave Reisner <dreisner@archlinux.org>

1 files changed, 8 insertions, 0 deletions

diff --git a/shutdown b/shutdown
index a9ac8c6..483f5b1 100644
--- a/shutdown
+++ b/shutdown
@@ -29,6 +29,14 @@ stop_device() {
             }
             ;;
         raid*)
+            # wait for arrays with external metadata to be marked as
+            # clean. unfortunately, there isn't a whole lot we can do
+            # if this fails, and the array may need a full rebuild on
+            # the next reboot.
+            IFS=: read metadata _ < "/sys/class/block/$1/md/metadata_version"
+            if [ "$metdata" = external ]; then
+                mdadm --wait-clean "/dev/$1"
+            fi
             mdadm --stop "/dev/$1"
             ;;
         dmraid)