Re: [PATCH 1/1] runqemu-export-rootfs and friends: don't put pseudo db in target fs

[Scott Garman <scott.a.garman@intel.com>]

On 08/21/2012 11:31 AM, Peter Seebach wrote:
> In a few places, we have scripts which use <rootfs>/var/pseudo for
> the pseudo state directory controlling a given filesystem. This
> seems possibly risky because it means that stuff running under
> qemu or whatnot could wipe out the data being used to handle that
> rootfs.
>
> Signed-off-by: Peter Seebach <peter.seebach@windriver.com>
> ---
>   .../installer/adt-installer/scripts/extract_rootfs |    7 +++----
>   scripts/runqemu-export-rootfs                      |    2 +-
>   scripts/runqemu-extract-sdk                        |   13 +++++++------
>   3 files changed, 11 insertions(+), 11 deletions(-)
>
> diff --git a/meta/recipes-devtools/installer/adt-installer/scripts/extract_rootfs b/meta/recipes-devtools/installer/adt-installer/scripts/extract_rootfs
> index 62dc170..0bbbeef 100755
> --- a/meta/recipes-devtools/installer/adt-installer/scripts/extract_rootfs
> +++ b/meta/recipes-devtools/installer/adt-installer/scripts/extract_rootfs
> @@ -28,7 +28,6 @@ extract_rootfs()
>     native_sysroot=$3
>     target_sysroot=$2
>     PSEUDO_COMMAND="$native_sysroot/usr/bin/pseudo"
> -  PSEUDO_OPTS="-P $natvie_sysroot/usr"
>     TAR_OPTS="-xjf"
>     PSEUDO_OPTS="-P $native_sysroot/usr"
>
> @@ -46,9 +45,9 @@ extract_rootfs()
>       mkdir -p "$target_sysroot"
>     fi
>
> -  mkdir -p "$target_sysroot/var/pseudo"
> -  touch "$target_sysroot/var/pseudo/pseudo.pid"
> -  PSEUDO_LOCALSTATEDIR="$target_sysroot/var/pseudo"
> +  mkdir -p "$target_sysroot/../pseudo_state"
> +  touch "$target_sysroot/../pseudo_state/pseudo.pid"
> +  PSEUDO_LOCALSTATEDIR="$target_sysroot/../pseudo_state"
>     export PSEUDO_LOCALSTATEDIR

This would mean that if someone tried to put multiple rootfs directories 
in the same subdirectory, they could clobber each other's pseudo_state 
data, correct? Putting multiple rootfs directories in the same subdir is 
a common use case already, I don't think we could break that.

If you appended the top-level rootfs directory name to ../pseudo_state, 
e.g, ../pseudo_state_<dirname>, that would keep the pseudo_state 
directories separate and make it fairly obvious what rootfs they 
belonged to.

Also, neither of these schemes would support having $target_sysroot 
directly under / (though I'm not sure why someone would do that).

Scott

-- 
Scott Garman
Embedded Linux Engineer - Yocto Project
Intel Open Source Technology Center