udev-cache: refactor conditionals and error handling

Most of /etc/init.d/udev-cache is in a conditional block which can be
replaced by a `[ ... ] || exit 0` to reduce nesting.

This also provides an opportunity to add some additional messages
when VERBOSE is set.

Capture and report errors encountered in the cache generation process,
using set -e and trap EXIT. These errors were previously being ignored.

(From OE-Core rev: a1357f3c78e46cd4297fefab56acf87342967132)

Signed-off-by: Richard Tollerton <rich.tollerton@ni.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 22 insertions, 13 deletions

diff --git a/meta/recipes-core/udev/udev/udev-cache b/meta/recipes-core/udev/udev/udev-cache
index 3c18061991..895b1971c4 100644
--- a/meta/recipes-core/udev/udev/udev-cache
+++ b/meta/recipes-core/udev/udev/udev-cache
@@ -42,19 +42,28 @@ if [ "$ROOTFS_READ_ONLY" = "yes" ]; then
     exit 0
 fi
 
-if [ "$DEVCACHE" != "" -a -e "$DEVCACHE_REGEN" ]; then
-        echo "Populating dev cache"
-        (
-                udevadm control --stop-exec-queue
-                sysconf_cmd > "$SYSCONF_TMP"
-                find /dev -xdev \( -type b -o -type c -o -type l \) | cut -c 2- \
-                        | xargs tar cf "${DEVCACHE_TMP}" -T-
-                        gzip < "${DEVCACHE_TMP}" > "$DEVCACHE"
-                        rm -f "${DEVCACHE_TMP}"
-                        mv "$SYSCONF_TMP" "$SYSCONF_CACHED"
-                        udevadm control --start-exec-queue
-                        rm -f "$DEVCACHE_REGEN"
-        ) &
+[ "$DEVCACHE" != "" ] || exit 0
+[ "${VERBOSE}" == "no" ] || echo -n "udev-cache: checking for ${DEVCACHE_REGEN}... "
+if ! [ -e "$DEVCACHE_REGEN" ]; then
+        [ "${VERBOSE}" == "no" ] || echo "not found."
+        exit 0
 fi
+[ "${VERBOSE}" == "no" ] || echo "found."
+echo "Populating dev cache"
+
+(
+        set -e
+        trap 'echo "udev-cache: update failed!"' EXIT
+        udevadm control --stop-exec-queue
+        sysconf_cmd > "$SYSCONF_TMP"
+        find /dev -xdev \( -type b -o -type c -o -type l \) | cut -c 2- \
+                | xargs tar cf "${DEVCACHE_TMP}" -T-
+        gzip < "${DEVCACHE_TMP}" > "$DEVCACHE"
+        rm -f "${DEVCACHE_TMP}"
+        mv "$SYSCONF_TMP" "$SYSCONF_CACHED"
+        udevadm control --start-exec-queue
+        rm -f "$DEVCACHE_REGEN"
+        trap - EXIT
+) &
 
 exit 0