dracut: support updates=hd:... (#807982)

Since we've removed all UI from initramfs, plain 'updates' no longer
works if you want to load an updates image from disk.

This adds support for fetching updates images, much the same way as we
do with kickstarts.

Note that I'd really like to merge all the *-genrules.sh / fetch-*-disk
junk, but time is short..

1 files changed, 33 insertions, 0 deletions

diff --git a/dracut/fetch-updates-disk b/dracut/fetch-updates-disk
new file mode 100755
index 000000000..168fe5d19
--- /dev/null
+++ b/dracut/fetch-updates-disk
@@ -0,0 +1,33 @@
+#!/bin/bash
+# fetch-updates-disk - fetch updates from a block device
+
+command -v getarg >/dev/null || . /lib/dracut-lib.sh
+command -v unpack_updates_img >/dev/null || . /lib/anaconda-lib.sh
+
+dev="$1"
+path="${2:-/updates.img}"
+
+[ -d "$path" ] && path=$path/updates.img
+[ -b "$dev" ] || exit 1
+
+info "anaconda: fetching updates from $dev:$path"
+
+mnt="$(find_mount $dev)"
+if [ -n "$mnt" ]; then
+    cp $mnt$path /tmp/updates.img
+else
+    tmpmnt="$(mkuniqdir /run/install tmpmnt)"
+    if mount -o ro $dev $tmpmnt; then
+        cp $tmpmnt$path /tmp/updates.img
+        umount $tmpmnt
+    fi
+    rmdir $tmpmnt
+fi
+
+if [ -f /tmp/updates.img ]; then
+    unpack_updates_img /tmp/updates.img /updates
+    rm /tmp/updates.img
+    echo "$dev:$path" >> /tmp/liveupdates.done
+else
+    warn "anaconda: failed to get updates from $dev:$path"
+fi