x86: sysupgrade: refactor platform_do_upgrade

By returning early when no upgrade device can be found and handling the
SAVE_PARTITIONS=0 case differently, we can get rid of two levels of if.

Signed-off-by: Matthias Schiffer <mschiffer@universe-factory.net>

diff --git a/target/linux/x86/base-files/lib/upgrade/platform.sh b/target/linux/x86/base-files/lib/upgrade/platform.sh
index 81b349a81816033eef9df464b2a70fdb998e5a1d..4fa71999be7be3972676a1019488972dccd57fa2 100644 (file)
--- a/target/linux/x86/base-files/lib/upgrade/platform.sh
+++ b/target/linux/x86/base-files/lib/upgrade/platform.sh
@@ -47,40 +47,43 @@ platform_copy_config() {
 platform_do_upgrade() {
        local diskdev partdev diff
 
-       if export_bootdevice && export_partdevice diskdev 0; then
-               sync
-               if [ "$SAVE_PARTITIONS" = "1" ]; then
-                       get_partitions "/dev/$diskdev" bootdisk
-
-                       #extract the boot sector from the image
-                       get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
-
-                       get_partitions /tmp/image.bs image
-
-                       #compare tables
-                       diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
-                       if [ -n "$diff" ]; then
-                               get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
-                               return 0
-                       fi
-
-                       #iterate over each partition from the image and write it to the boot disk
-                       while read part start size; do
-                               if export_partdevice partdev $part; then
-                                       echo "Writing image to /dev/$partdev..."
-                                       get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
-                               else
-                                       echo "Unable to find partition $part device, skipped."
-                               fi
-                       done < /tmp/partmap.image
-
-                       #copy partition uuid
-                       echo "Writing new UUID to /dev/$diskdev..."
-                       get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
+       export_bootdevice && export_partdevice diskdev 0 || {
+               echo "Unable to determine upgrade device"
+               return 1
+       }
+
+       sync
+
+       if [ "$SAVE_PARTITIONS" = "1" ]; then
+               get_partitions "/dev/$diskdev" bootdisk
+
+               #extract the boot sector from the image
+               get_image "$@" | dd of=/tmp/image.bs count=1 bs=512b
+
+               get_partitions /tmp/image.bs image
+
+               #compare tables
+               diff="$(grep -F -x -v -f /tmp/partmap.bootdisk /tmp/partmap.image)"
+       else
+               diff=1
+       fi
+
+       if [ -n "$diff" ]; then
+               get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
+               return 0
+       fi
+
+       #iterate over each partition from the image and write it to the boot disk
+       while read part start size; do
+               if export_partdevice partdev $part; then
+                       echo "Writing image to /dev/$partdev..."
+                       get_image "$@" | dd of="/dev/$partdev" ibs="512" obs=1M skip="$start" count="$size" conv=fsync
                else
-                       get_image "$@" | dd of="/dev/$diskdev" bs=4096 conv=fsync
+                       echo "Unable to find partition $part device, skipped."
                fi
+       done < /tmp/partmap.image
 
-               sleep 1
-       fi
+       #copy partition uuid
+       echo "Writing new UUID to /dev/$diskdev..."
+       get_image "$@" | dd of="/dev/$diskdev" bs=1 skip=440 count=4 seek=440 conv=fsync
 }