Re: [PATCH v3] common/defrag: skip defrag tests on DAX-enabled filesystems

[Zorro Lang <zlang@kernel.org>]

On Mon, Jun 08, 2026 at 03:53:28PM +0530, Disha Goel wrote:
> Online defragmentation is not supported on ext4 DAX-enabled filesystems.
> The ext4 defrag ioctl (EXT4_IOC_MOVE_EXT) returns EOPNOTSUPP when used
> on DAX files.
> 
> Add an ext4-specific check in _require_defrag() to skip tests when DAX
> is enabled, avoiding false failures on ext4/301-304, ext4/308, and
> generic/018.
> 
> XFS defrag works with DAX, so this check is ext4-specific.
> 
> Suggested-by: Darrick J. Wong <djwong@kernel.org>
> Signed-off-by: Disha Goel <disgoel@linux.ibm.com>
> Reviewed-by: Ojaswin Mujoo <ojaswin@linux.ibm.com>
> ---
> Changes in v3:
> - Move the DAX check inside the ext4 case statement as
>   suggested by Darrick

Make sense to me,

Reviewed-by: Zorro Lang <zlang@kernel.org>

> 
>  common/defrag | 2 ++
>  1 file changed, 2 insertions(+)
> 
> diff --git a/common/defrag b/common/defrag
> index 055d0d0e..baf05d94 100644
> --- a/common/defrag
> +++ b/common/defrag
> @@ -13,6 +13,8 @@ _require_defrag()
>          DEFRAG_PROG="$XFS_FSR_PROG"
>  	;;
>      ext4)
> +        __scratch_uses_fsdax && _notrun "ext4 online defrag not supported with DAX"
> +
>  	testfile="$TEST_DIR/$$-test.defrag"
>  	donorfile="$TEST_DIR/$$-donor.defrag"
>  	bsize=`_get_block_size $TEST_DIR`
> -- 
> 2.45.1
> 
>