From b0472eac111268e2cae783097d0eccc1986e1762 Mon Sep 17 00:00:00 2001

From: Fabian Deutsch <fabiand@fedoraproject.org>

Date: Thu, 19 Feb 2015 10:09:14 +0100

Subject: [PATCH] dmsquash: Add squashfs support to rd.live.fsimg

Previously rd.live.fsimg only supported filesystems residing in

(compressed) archives.

Now rd.live.fsimg can also be used when a squashfs image is used.

This is achieved by extracting the rootfs image from the squashfs and

then continue with the default routines for rd.live.fsimg.

In addition some code duplication got removed and some documentation

got added.

Signed-off-by: Fabian Deutsch <fabiand@fedoraproject.org>

---

 dracut.cmdline.7.asc                            |  9 ++++

 modules.d/90dmsquash-live/dmsquash-live-root.sh | 64 +++++++++++++------------

 2 files changed, 42 insertions(+), 31 deletions(-)

diff --git a/dracut.cmdline.7.asc b/dracut.cmdline.7.asc

index 9ddad0f..e51fd1b 100644

--- a/dracut.cmdline.7.asc

+++ b/dracut.cmdline.7.asc

@@ -834,6 +834,10 @@ Enables debug output from the live boot process.

 Specifies the directory within the squashfs where the ext3fs.img or rootfs.img

 can be found.  By default, this is __LiveOS__.

+**rd.live.ram=**1::

+Copy the complete image to RAM and use this for booting. This is useful

+when the image resides on i.e. a DVD which needs to be ejected later on.

+

 **rd.live.overlay.thin=**1::

 Enables the usage of thin snapshots instead of classic dm snapshots.

 The advantage of thin snapshots is, that they support discards, and will free

@@ -846,6 +850,11 @@ Enables writable filesystem support.  The system will boot with a fully

 writable filesystem without snapshots __(see notes above about available live boot options)__.

 You can use the **rootflags** option to set mount options for the live

 filesystem as well __(see documentation about rootflags in the **Standard** section above)__.

+This implies that the whole image is copied to RAM before the boot continues.

++

+NOTE: There must be enough free RAM available to hold the complete image.

++

+This method is very suitable for diskless boots.

 Plymouth Boot Splash

diff --git a/modules.d/90dmsquash-live/dmsquash-live-root.sh b/modules.d/90dmsquash-live/dmsquash-live-root.sh

index 45f724c..b632f6a 100755

--- a/modules.d/90dmsquash-live/dmsquash-live-root.sh

+++ b/modules.d/90dmsquash-live/dmsquash-live-root.sh

@@ -148,6 +148,7 @@ do_live_overlay() {

         base=$BASE_LOOPDEV

         over=$OVERLAY_LOOPDEV

     fi

+

     if [ -n "$thin_snapshot" ]; then

         modprobe dm_thin_pool

         mkdir /run/initramfs/thin-overlay

@@ -199,29 +200,6 @@ if [ -n "$OSMINSQFS" ]; then

     umount -l /run/initramfs/squashfs.osmin

 fi

-# we might have an embedded fs image to use as rootfs (uncompressed live)

-if [ -e /run/initramfs/live/${live_dir}/ext3fs.img ]; then

-    FSIMG="/run/initramfs/live/${live_dir}/ext3fs.img"

-elif [ -e /run/initramfs/live/${live_dir}/rootfs.img ]; then

-    FSIMG="/run/initramfs/live/${live_dir}/rootfs.img"

-fi

-

-if [ -n "$FSIMG" ] ; then

-    BASE_LOOPDEV=$( losetup -f )

-

-    if [ -n "$writable_fsimg" ] ; then

-        # mount the provided fileysstem read/write

-        echo "Unpacking live filesystem (may take some time)"

-        unpack_archive $FSIMG /run/initramfs/fsimg/

-        losetup $BASE_LOOPDEV /run/initramfs/fsimg/rootfs.img

-        echo "0 $( blockdev --getsize $BASE_LOOPDEV ) linear $BASE_LOOPDEV 0" | dmsetup create live-rw

-    else

-        # mount the filesystem read-only and add a dm snapshot for writes

-        losetup -r $BASE_LOOPDEV $FSIMG

-        do_live_from_base_loop

-    fi

-fi

-

 # we might have an embedded fs image on squashfs (compressed live)

 if [ -e /run/initramfs/live/${live_dir}/${squash_image} ]; then

     SQUASHED="/run/initramfs/live/${live_dir}/${squash_image}"

@@ -242,18 +220,42 @@ if [ -e "$SQUASHED" ] ; then

     mkdir -m 0755 -p /run/initramfs/squashfs

     mount -n -t squashfs -o ro $SQUASHED_LOOPDEV /run/initramfs/squashfs

-    BASE_LOOPDEV=$( losetup -f )

-    if [ -f /run/initramfs/squashfs/LiveOS/ext3fs.img ]; then

-        losetup -r $BASE_LOOPDEV /run/initramfs/squashfs/LiveOS/ext3fs.img

-    elif [ -f /run/initramfs/squashfs/LiveOS/rootfs.img ]; then

-        losetup -r $BASE_LOOPDEV /run/initramfs/squashfs/LiveOS/rootfs.img

-    fi

+fi

+

+# we might have an embedded fs image to use as rootfs (uncompressed live)

+if [ -e /run/initramfs/live/${live_dir}/ext3fs.img ]; then

+    FSIMG="/run/initramfs/live/${live_dir}/ext3fs.img"

+elif [ -e /run/initramfs/live/${live_dir}/rootfs.img ]; then

+    FSIMG="/run/initramfs/live/${live_dir}/rootfs.img"

+elif [ -f /run/initramfs/squashfs/LiveOS/ext3fs.img ]; then

+    FSIMG="/run/initramfs/squashfs/LiveOS/ext3fs.img"

+elif [ -f /run/initramfs/squashfs/LiveOS/rootfs.img ]; then

+    FSIMG="/run/initramfs/squashfs/LiveOS/rootfs.img"

+fi

-    umount -l /run/initramfs/squashfs

+if [ -n "$FSIMG" ] ; then

+    BASE_LOOPDEV=$( losetup -f )

-    do_live_from_base_loop

+    if [ -n "$writable_fsimg" ] ; then

+        # mount the provided fileysstem read/write

+        echo "Unpacking live filesystem (may take some time)"

+        mkdir /run/initramfs/fsimg/

+        if [ -n "$SQUASHED" ]; then

+            cp -v $FSIMG /run/initramfs/fsimg/rootfs.img

+        else

+            unpack_archive $FSIMG /run/initramfs/fsimg/

+        fi

+        losetup $BASE_LOOPDEV /run/initramfs/fsimg/rootfs.img

+        echo "0 $( blockdev --getsize $BASE_LOOPDEV ) linear $BASE_LOOPDEV 0" | dmsetup create live-rw

+    else

+        # mount the filesystem read-only and add a dm snapshot for writes

+        losetup -r $BASE_LOOPDEV $FSIMG

+        do_live_from_base_loop

+    fi

 fi

+[ -e "$SQUASHED" ] && umount -l /run/initramfs/squashfs

+

 if [ -b "$OSMIN_LOOPDEV" ]; then

     # set up the devicemapper snapshot device, which will merge

     # the normal live fs image, and the delta, into a minimzied fs image