Re: [PATCH v1.2 3/3] common/ext4: provide custom ext4 scratch fs options

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

On Wed, Aug 03, 2022 at 05:25:11PM -0700, Darrick J. Wong wrote:
> From: Darrick J. Wong <djwong@kernel.org>
> 
> Create a _scratch_options backend for ext* so that we can inject
> pathnames to external log devices into the scratch fs mount options.
> This enables common/dm* to install block device filters, e.g. dm-error
> for stress testing.
> 
> Signed-off-by: Darrick J. Wong <djwong@kernel.org>
> v1.2: refactor _scratch_mkfs_ext4 to use _scratch_options too

Self NAK, this still has broken bits...

> ---
>  common/ext4 |   34 +++++++++++++++++++++++++++++++---
>  common/rc   |    3 +++
>  2 files changed, 34 insertions(+), 3 deletions(-)
> 
> diff --git a/common/ext4 b/common/ext4
> index 287705af..8a3385af 100644
> --- a/common/ext4
> +++ b/common/ext4
> @@ -63,16 +63,24 @@ _setup_large_ext4_fs()
>  	return 0
>  }
>  
> +_scratch_mkfs_ext4_opts()
> +{
> +	mkfs_opts=$*
> +
> +	_scratch_options mkfs
> +
> +	echo "$MKFS_EXT4_PROG -F $SCRATCH_OPTIONS $mkfs_opts"

...the -F should go in _scratch_ext4_options...

> +}
> +
>  _scratch_mkfs_ext4()
>  {
> -	local mkfs_cmd="$MKFS_EXT4_PROG -F"
> +	local mkfs_cmd="`_scratch_mkfs_ext4_opts`"
>  	local mkfs_filter="grep -v -e ^Warning: -e \"^mke2fs \" | grep -v \"^$\""
>  	local tmp=`mktemp -u`
>  	local mkfs_status
>  
>  	[ "$USE_EXTERNAL" = yes -a ! -z "$SCRATCH_LOGDEV" ] && \
> -	    $mkfs_cmd -O journal_dev $MKFS_OPTIONS $SCRATCH_LOGDEV && \
> -	    mkfs_cmd="$mkfs_cmd -J device=$SCRATCH_LOGDEV"
> +	    $MKFS_EXT4_PROG -F -O journal_dev $MKFS_OPTIONS $SCRATCH_LOGDEV
>  
>  	_scratch_do_mkfs "$mkfs_cmd" "$mkfs_filter" $* 2>$tmp.mkfserr 1>$tmp.mkfsstd
>  	mkfs_status=$?
> @@ -154,3 +162,23 @@ _require_scratch_richacl_ext4()
>  		|| _notrun "kernel doesn't support richacl feature on $FSTYP"
>  	_scratch_unmount
>  }
> +
> +_scratch_ext4_options()
> +{
> +    local type=$1
> +    local log_opt=""
> +
> +    case $type in
> +    mkfs)
> +        log_opt="-J device=$SCRATCH_LOGDEV"
> +	;;
> +    mount)
> +	# As of kernel 5.19, the kernel mount option path parser only accepts
> +	# direct paths to block devices--the final path component cannot be a
> +	# symlink.
> +        log_opt="-o journal_path=$(realpath $SCRATCH_LOGDEV)"

...and this ought to be `realpath -q "$SCRATCH_LOGDEV"' to avoid
breaking the non-external-journal case.

> +	;;
> +    esac
> +    [ "$USE_EXTERNAL" = yes -a ! -z "$SCRATCH_LOGDEV" ] && \
> +	SCRATCH_OPTIONS="$SCRATCH_OPTIONS ${log_opt}"

Tab/space insanity here.

--D

> +}
> diff --git a/common/rc b/common/rc
> index dc1d65c3..b82bb36b 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -178,6 +178,9 @@ _scratch_options()
>      "xfs")
>  	_scratch_xfs_options "$@"
>  	;;
> +    ext2|ext3|ext4|ext4dev)
> +	_scratch_ext4_options "$@"
> +	;;
>      esac
>  }
>