Re: [PATCH 0/7] Create ext* filesystems using debugfs

[Saul Wold <sgw@linux.intel.com>]

On 02/26/2013 01:24 AM, Robert Yang wrote:
> ===Contents===
>    * Summary
>    * Brief design
>    * Test info
>    * The rootfs generation time changes
>    * The rootfs size changes
>
> * Summary:
>    The ext3 and ext4 rootfs generation relied on genext2fs and flipping
>    some bits to "convert" the ext2 filesystem to ext3 and ext4 in the past,
>    now we use the mkfs.ext3/ext4 to create the image, and use mkdebugfs.sh
>    to copy the files to the image.
>
> * Brief design:
>    - Upgrade the e2fsprogs to the update to date version (the git
>      repo) which contains the "symlink" command in debugfs shell that we
>      need.
This should really be an RFC

This work was intended to be a step toward incorporating it into 
genext2fs directly.  At this point we do not want to switch to the GIT 
version of e2fsprogs, there is an update to e2fsprogs pending on the 
patch queue that addes the symlink support (crossed with your request)

>    - Replace the current genext2fs command with mkdebugfs.sh in
>      image_types.bbclass.

The goal is to change genext2fs to support a rootfs option an not 
replace it with mkdebugfs.

>    - The new steps to generate the root filesystem are:
>      -> use "dd" command to make rootfs.ext* file
Why the dd?

>      -> run "mkfs.ext* rootfs.ext*" to create the filesystem
>      -> run the mkdebugfs.sh to generate the root filesystem
>



> * Test info: (MACHINE = qemuarm, IMAGE_FSTYPES = "ext2 ext3 ext4 tar.bz2")
>    $ bitbake core-image-minimal core-image-sato meta-toolchain-sdk core-image-sato-sdk
>    $ runqemu runqemu qemuarm core-image-sato ext3
>    $ runqemu runqemu qemuarm core-image-minimal ext3
>
>    All of them are OK

What about booting an ext4 image, part of the goal of this was to enable 
ext4.

>
> * The rootfs generation time changes
>    - For a core-image-minimal generation (IMAGE_FSTYPES="tar.bz2 ext3"):
>
>      Before:
>      $ time bitbake core-image-minimal
>
>      real    1m10.823s
>      user    0m37.108s
>      sys     0m15.894s
>
>      After:
>      $ time bitbake core-image-minimal
>
>      real    1m17.501s
>      user    0m29.304s
>      sys     0m20.731s
>
>      # 7 seconds lost.
>
>    - For a core-image-sato generation (IMAGE_FSTYPES="tar.bz2 ext3"):
>
>      Before:
>      $ time bitbake core-image-sato
>
>      real    11m10.645s
>      user    2m43.503s
>      sys     1m1.589s
>
>      After:
>      $ time bitbake core-image-sato
>
>      real    11m53.131s
>      user    3m18.988s
>      sys     2m8.350s
>
>      # 43 seconds lost.
>
> * The rootfs size changes
>    - The image size are the same by "ls -h", but different by "du -sh":
>      (core-image-sato)
>
>      $ ls -lh BEFORE.rootfs.ext3 AFTER.rootfs.ext3 | awk '{print $5"\t"$NF}'
>      357M BEFORE.rootfs.ext3
>      357M AFTER.rootfs.ext3
>
>      $ du -sh BEFORE.rootfs.ext3 AFTER.rootfs.ext3
>      238M    BEFORE.rootfs.ext3
>      357M    AFTER.rootfs.ext3
>
>      It seems that the genext2fs has optimized the rootfs generation.
>
> // Robert
>
> The following changes since commit 2cc4fe4a0874c42421b1bf3fa100160a9e60a9da:
>
>    upstream_tracking.inc: Coonectivity and multimedia packages updates (2013-02-25 05:58:20 -0800)
>
> are available in the git repository at:
>
>    git://git.pokylinux.org/poky-contrib robert/e2fsprogs
>    http://git.pokylinux.org/cgit.cgi/poky-contrib/log/?h=robert/e2fsprogs
>
> Robert Yang (7):
>    e2fsprogs: upgrade to the git version (rename only)
>    e2fsprogs: upgrade to the git version
>    e2fsprogs: add the original mkdebugfs.sh
>    mkdebugfs.sh: convert the tab to 4 spaces
>    mkdebugfs.sh: several fixes
>    e2fsprogs: ship mkfsdebug.sh
>    image_types.bbclass: replace genext2fs with mkdebugfs.sh
>
>   meta/classes/image_types.bbclass                   | 45 +++++-------
>   meta/recipes-devtools/e2fsprogs/e2fsprogs.inc      |  4 +-
>   .../{e2fsprogs-1.42.6 => e2fsprogs}/acinclude.m4   |  0
>   .../fallocate.patch                                |  0
>   .../e2fsprogs/e2fsprogs/mkdebugfs.sh               | 82 ++++++++++++++++++++++
>   .../{e2fsprogs-1.42.6 => e2fsprogs}/mkdir.patch    |  0
>   .../remove.ldconfig.call.patch                     |  0
>   .../{e2fsprogs_1.42.6.bb => e2fsprogs_git.bb}      |  6 +-
>   8 files changed, 106 insertions(+), 31 deletions(-)
>   rename meta/recipes-devtools/e2fsprogs/{e2fsprogs-1.42.6 => e2fsprogs}/acinclude.m4 (100%)
>   rename meta/recipes-devtools/e2fsprogs/{e2fsprogs-1.42.6 => e2fsprogs}/fallocate.patch (100%)
>   create mode 100644 meta/recipes-devtools/e2fsprogs/e2fsprogs/mkdebugfs.sh
>   rename meta/recipes-devtools/e2fsprogs/{e2fsprogs-1.42.6 => e2fsprogs}/mkdir.patch (100%)
>   rename meta/recipes-devtools/e2fsprogs/{e2fsprogs-1.42.6 => e2fsprogs}/remove.ldconfig.call.patch (100%)
>   rename meta/recipes-devtools/e2fsprogs/{e2fsprogs_1.42.6.bb => e2fsprogs_git.bb} (92%)
>