Re: [PATCH V4 01/11] common/xfs: Add a helper to get an inode fork's extent count

Darrick J. Wong
2021-03-04T00:26:59Z

On Mon, Jan 18, 2021 at 11:50:12AM +0530, Chandan Babu R wrote:
> This commit adds the helper _scratch_get_iext_count() which returns an
> inode fork's extent count.
>
> Signed-off-by: Chandan Babu R <chandanrlinux@gmail.com>
> ---
> common/xfs | 22 ++++++++++++++++++++++
> 1 file changed, 22 insertions(+)
>
> diff --git a/common/xfs b/common/xfs
> index 3f5c14ba..641d6195 100644
> --- a/common/xfs
> +++ b/common/xfs
> @@ -903,6 +903,28 @@ _scratch_get_bmx_prefix() {
> return 1
> }
>
> +_scratch_get_iext_count()
> +{
> + ino=$1
> + whichfork=$2

Function variables should be declared with 'local' so they don't bleed
into the global namespace (yay bash!), e.g.

local ino="$1"

Also, now that Eric has landed the xfs_db 'path' command upstream, you
might consider using it:

_scratch_xfs_get_metadata_field "core.nextents" "path /windows/system.ini"

> +
> + case $whichfork in
> + "attr")
> + field=core.naextents
> + ;;
> + "data")
> + field=core.nextents
> + ;;
> + *)
> + return 1
> + esac
> +
> + nextents=$(_scratch_xfs_db -c "inode $ino" -c "print $field")
> + nextents=${nextents##${field} = }

_scratch_xfs_get_metadata_field?

--D

> +
> + echo $nextents
> +}
> +
> #
> # Ensures that we don't pass any mount options incompatible with XFS v4
> #
> --
> 2.29.2
>