Re: [f2fs-dev] [PATCH v2] f2fs/012: adapt lookup_mode=x mount option

[Zorro L. <zl...@re...>]

On Sat, Aug 16, 2025 at 03:29:09PM +0800, Chao Yu wrote:
> w/ below change [1], f2fs will enable lookup_mode=perf by default, it
> will change f2fs dirent lookup method from linear based lookup to hash
> based lookup.
> 
> So that, f2fs will ignore sb.s_encoding_flags by default, which is not
> compatible w/ f2fs/012 testcase, in where it will control lookup method
> by configuring this flag w/ fsck.f2fs.
> 
> To avoid failure of f2fs/012, let's check whether f2fs has supported
> "lookup_mode=auto" mount option, mount w/ the option if it can,
> otherwise, don't.
> 
> [1] https://lore.kernel.org/linux-f2fs-devel/202...@go...
> 
> Cc: Jaegeuk Kim <ja...@ke...>
> Cc: Daniel Lee <ch...@go...>
> Signed-off-by: Chao Yu <ch...@ke...>
> ---
> v2:
> - ignore error from _try_scratch_mount "-o lookup_mode=auto"

This version looks good to me, thanks for fixing it.

Reviewed-by: Zorro Lang <zl...@re...>

>  tests/f2fs/012 | 13 +++++++++++--
>  1 file changed, 11 insertions(+), 2 deletions(-)
> 
> diff --git a/tests/f2fs/012 b/tests/f2fs/012
> index b3df9a8f..7438d9ce 100755
> --- a/tests/f2fs/012
> +++ b/tests/f2fs/012
> @@ -22,6 +22,15 @@ _require_scratch_nocheck
>  _require_command "$F2FS_IO_PROG" f2fs_io
>  _require_command "$F2FS_INJECT_PROG" inject.f2fs
>  
> +#check whether f2fs supports "lookup_mode=x" mount option
> +mntopt=""
> +_scratch_mkfs -O casefold -C utf8 >> $seqres.full
> +_try_scratch_mount "-o lookup_mode=auto" >> $seqres.full 2>&1
> +if [ $? == 0 ]; then
> +	mntopt="-o lookup_mode=auto"
> +	_scratch_unmount
> +fi
> +
>  check_lookup()
>  {
>  	local nolinear_lookup=$1
> @@ -30,7 +39,7 @@ check_lookup()
>  	local redheart=$dir/$'\u2764\ufe0f'
>  
>  	_scratch_mkfs -O casefold -C utf8 >> $seqres.full
> -	_scratch_mount
> +	_scratch_mount $mntopt
>  
>  	mkdir $dir
>  	$F2FS_IO_PROG setflags casefold $dir >> $seqres.full
> @@ -52,7 +61,7 @@ check_lookup()
>  
>  	$F2FS_INJECT_PROG --dent --mb d_hash --nid $ino --val 0x9a2ea068 $SCRATCH_DEV >> $seqres.full
>  
> -	_scratch_mount
> +	_scratch_mount $mntopt
>  	if [ $nolinear_lookup == "1" ]; then
>  		[ -f $redheart ] && _fail "red heart file should not exist"
>  	else
> -- 
> 2.49.0
>