From 123feea1fab225478046db43454b10453df95b51 Mon Sep 17 00:00:00 2001

From: P J P <ppandit@redhat.com>

Date: Fri, 11 Oct 2013 19:26:51 +0530

Subject: [PATCH] Add lzo, lz4 compression and read INITRD_COMPRESS

This patch adds support for lzop(1) & lz4(1) compression

algorithms to compress iniramfs image file. Both are supported

by the Linux kernel.

Linux kernel exports user's choice of initramfs compression

algorithm as a shell environment variable: INITRD_COMPRESS.

This patch adds support to read this variable and duly compress

the initramfs image file.

Environment variable INITRD_COMPRESS has less precedence than the

command line options --gzip, etc. Ie. command line options could

override the compression algorithm defined by $INITRD_COMPRESS.

Signed-off-by: P J P <ppandit@redhat.com>

[Edited-by: Harald Hoyer: add documentation about lzo and lz4]

---

 dracut.8.asc | 16 ++++++++++++++++

 dracut.sh    | 13 +++++++++++++

 2 files changed, 29 insertions(+)

diff --git a/dracut.8.asc b/dracut.8.asc

index 584514c..2ea6744 100644

--- a/dracut.8.asc

+++ b/dracut.8.asc

@@ -365,6 +365,22 @@ Make sure your kernel has xz decompression support compiled in, otherwise you

 will not be able to boot. Equivalent to "lzma --compress=xz --check=crc32 --lzma2=dict=1MiB"

 ====

+**--lzo**::

+    Compress the generated initramfs using lzop.

+[WARNING]

+====

+Make sure your kernel has lzo decompression support compiled in, otherwise you

+will not be able to boot.

+====

+

+**--lz4**::

+    Compress the generated initramfs using lz4.

+[WARNING]

+====

+Make sure your kernel has lz4 decompression support compiled in, otherwise you

+will not be able to boot.

+====

+

 **--compress** _<compressor>_::

     Compress the generated initramfs using the passed compression program. If

     you pass it just the name of a compression program, it will call that

diff --git a/dracut.sh b/dracut.sh

index d9533dd..173a259 100755

--- a/dracut.sh

+++ b/dracut.sh

@@ -165,6 +165,12 @@ Creates initial ramdisk images for preloading modules

   --xz                  Compress the generated initramfs using xz.

                          Make sure that your kernel has xz support compiled

                          in, otherwise you will not be able to boot.

+  --lzo                  Compress the generated initramfs using lzop.

+                         Make sure that your kernel has lzo support compiled

+                         in, otherwise you will not be able to boot.

+  --lz4                  Compress the generated initramfs using lz4.

+                         Make sure that your kernel has lz4 support compiled

+                         in, otherwise you will not be able to boot.

   --compress [COMPRESSION] Compress the generated initramfs with the

                          passed compression program.  Make sure your kernel

                          knows how to decompress the generated initramfs,

@@ -342,6 +348,8 @@ TEMP=$(unset POSIXLY_CORRECT; getopt \

     --long bzip2 \

     --long lzma \

     --long xz \

+    --long lzo \

+    --long lz4 \

     --long no-compress \

     --long gzip \

     --long list-modules \

@@ -430,6 +438,8 @@ while :; do

         --bzip2)       compress_l="bzip2";;

         --lzma)        compress_l="lzma";;

         --xz)          compress_l="xz";;

+        --lzo)         compress_l="lzo";;

+        --lz4)         compress_l="lz4";;

         --no-compress) _no_compress_l="cat";;

         --gzip)        compress_l="gzip";;

         --list-modules) do_list="yes";;

@@ -673,6 +683,7 @@ stdloglvl=$((stdloglvl + verbosity_mod_l))

 [[ $fw_dir ]] || fw_dir="/lib/firmware/updates /lib/firmware"

 [[ $tmpdir_l ]] && tmpdir="$tmpdir_l"

 [[ $tmpdir ]] || tmpdir=/var/tmp

+[[ $INITRD_COMPRESS ]] && compress=$INITRD_COMPRESS

 [[ $compress_l ]] && compress=$compress_l

 [[ $show_modules_l ]] && show_modules=$show_modules_l

 [[ $nofscks_l ]] && nofscks="yes"

@@ -689,6 +700,8 @@ case $compress in

     lzma)  compress="lzma -9";;

     xz)    compress="xz --check=crc32 --lzma2=dict=1MiB";;

     gzip)  compress="gzip -9"; command -v pigz > /dev/null 2>&1 && compress="pigz -9";;

+    lzo)   compress="lzop -9";;

+    lz4)   compress="lz4 -9";;

 esac

 if [[ $_no_compress_l = "cat" ]]; then

     compress="cat"