Re: [arch-projects] [RFC] Remove cut, grep and sed from mdadm initcpio hook

18 Nov 2011

On 11/16/2011 03:34 AM, Gerardo Exequiel Pozzi wrote:
...
https://gist.github.com/1369428 (this patch)
https://gist.github.com/1369424 (standalone test script)

--- /lib/initcpio/hooks/mdadm    2011-09-14 04:10:48.000000000 -0300
+++ hooks/mdadm    2011-11-16 03:32:30.064535002 -0300
@@ -6,7 +6,7 @@
     # for partitionable raid, we need to load md_mod first!
     modprobe md_mod 2>/dev/null
     # If md is specified on commandline, create config file from 
those parameters.
-    if [ "$(echo $input | grep "md=")" ]; then
+    if [ -n "${md}" ]; then
         #Create initial mdadm.conf
         # scan all devices in /proc/partitions
         echo DEVICE partitions > $mdconfig
@@ -14,26 +14,30 @@
             case $i in
                 # raid
                 md=[0-9]*,/*)
-                    device="$(echo "$i" | sed -e 's|,/.*||g' -e 
's|=||g')"
-                    array="$(echo $i | cut -d, -f2-)"
+                    device="${i%%,*}"
+                    device="${device/=/}"
+                    array="${i#*,}"
                     echo "ARRAY /dev/$device devices=$array" >> 
$mdconfig
                     ;;
                 # partitionable raid
                 md=d[0-9]*,/*)
-                    device="$(echo "$i" | sed -e 's|,/.*||g' -e 
's|=|_|g')"
-                    array="$(echo $i | cut -d, -f2-)"
+                    device="${i%%,*}"
+                    device="${device/=/_}"
+                    array="${i#*,}"
                     echo "ARRAY /dev/$device devices=$array" >> 
$mdconfig
                     ;;
                 # raid UUID
-                md=[0-9]*,[0-9,a-z]*)
-                    device="$(echo "$i" | sed -e 's|,.*||g' -e 
's|=||g')"
-                    array="$(echo $i | cut -d, -f2-)"
+                md=[0-9]*,[0-9,a-f]*)
+                    device="${i%%,*}"
+                    device="${device/=/}"
+                    array="${i#*,}"
                     echo "ARRAY /dev/$device UUID=$array" >> $mdconfig
                     ;;
                 # partitionable raid UUID
-                md=d[0-9]*,[0-9,a-z]*)
-                    device="$(echo "$i" | sed -e 's|,.*||g' -e 
's|=|_|g')"
-                    array="$(echo $i | cut -d, -f2-)"
+                md=d[0-9]*,[0-9,a-f]*)
+                    device="${i%%,*}"
+                    device="${device/=/_}"
+                    array="${i#*,}"
                     echo "ARRAY /dev/$device UUID=$array" >> $mdconfig
                     ;;
             esac
I guess that this code can be simplified a bit, does not make sense 
today differentiate between non-partitioned and partitioned md devs. 
 From mdadm(8) manpage:

"From  kernel version, 2.6.28 the "non-partitioned array" can actually 
be partitioned.  So the "md_dNN" names are no longer needed, and 
partitions such as "/dev/mdNNpXX" are possible."

Maybe we can add some note if user wants the legacy name.



-- 
Gerardo Exequiel Pozzi
\cos^2\alpha + \sin^2\alpha = 1

    