Poll DASD status for 'online' or 'unformatted' (#536803)

Give DASD devices some time to enter the online or unformatted state
before calling udevadm settle.  Max duration of loop is suggestion from
IBM.

1 files changed, 24 insertions, 0 deletions

diff --git a/loader/linuxrc.s390 b/loader/linuxrc.s390
index a3ee66564..7fd3f4fa2 100644
--- a/loader/linuxrc.s390
+++ b/loader/linuxrc.s390
@@ -129,6 +129,25 @@ function sysecho () {
     [ -f "$file" ] && echo $* > $file
 }
 
+function dasd_settle() {
+    local dasd=/sys/bus/ccw/devices/$1
+    if [ ! -d "$dasd" ]; then
+        return 1
+    fi
+    local i=1
+    while [ $i -le 30 ] ; do
+        status="$(< /sys/bus/ccw/devices/$dasd/status 2>/dev/null)"
+        case $status in
+            online|unformatted)
+                return 0 ;;
+            *)
+                sleep 0.1
+                i=$((i+1)) ;;
+        esac
+    done
+    return 1
+}
+
 function startinetd()
 {
     echo
@@ -190,6 +209,11 @@ function readcmsfile() # $1=dasdport $2=filename
         return 1
     fi
     udevadm settle
+    if ! dasd_settle $dev ; then
+        echo $"Could not access DASD $dev in time"
+        return 1
+    fi
+    udevadm settle
     if ! cmsfscat -d /dev/dasda -a $2 > /tmp/$2; then
         echo $"Could not read conf file $2 on CMS DASD $1."
     fi