Re: [PATCH] fsck.xfs: fix fsck.xfs run by different shells when fsck.mode=force is set

["Darrick J. Wong" <djwong@kernel.org>]

On Tue, Aug 13, 2024 at 03:25:51PM +0800, Gerald Yang wrote:
> When fsck.mode=force is specified in the kernel command line, fsck.xfs
> is executed during the boot process. However, when the default shell is
> not bash, $PS1 should be a different value, consider the following script:
> cat ps1.sh
> echo "$PS1"
> 
> run ps1.sh with different shells:
> ash ./ps1.sh
> $
> bash ./ps1.sh
> 
> dash ./ps1.sh
> $
> ksh ./ps1.sh
> 
> zsh ./ps1.sh
> 
> On systems like Ubuntu, where dash is the default shell during the boot
> process to improve startup speed. This results in FORCE being incorrectly
> set to false and then xfs_repair is not invoked:
> if [ -n "$PS1" -o -t 0 ]; then
>         FORCE=false
> fi
> 
> Other distros may encounter this issue too if the default shell is set
> to anoother shell.
> 
> Check "-t 0" is enough to determine if we are in interactive mode, and
> xfs_repair is invoked as expected regardless of the shell used.
> 
> Fixes: 04a2d5dc ("fsck.xfs: allow forced repairs using xfs_repair")
> Signed-off-by: Gerald Yang <gerald.yang@canonical.com>
> ---
>  fsck/xfs_fsck.sh | 4 ++--
>  1 file changed, 2 insertions(+), 2 deletions(-)
> 
> diff --git a/fsck/xfs_fsck.sh b/fsck/xfs_fsck.sh
> index 62a1e0b3..19ada9a7 100755
> --- a/fsck/xfs_fsck.sh
> +++ b/fsck/xfs_fsck.sh
> @@ -55,12 +55,12 @@ fi
>  # directly.
>  #
>  # Use multiple methods to capture most of the cases:
> -# The case for *i* and -n "$PS1" are commonly suggested in bash manual
> +# The case for *i* is commonly suggested in bash manual
>  # and the -t 0 test checks stdin
>  case $- in
>  	*i*) FORCE=false ;;

I can't remember why we allow any argument with the letter 'i' in it to
derail an xfs_repair -f invocation??

Regardless, the bits you changed look correct so
Reviewed-by: Darrick J. Wong <djwong@kernel.org>

--D

>  esac
> -if [ -n "$PS1" -o -t 0 ]; then
> +if [ -t 0 ]; then
>  	FORCE=false
>  fi
>  
> -- 
> 2.43.0
> 
>