Re: [PATCH v4 1/2] common/rc: add functions to check or write objects under /sys/fs/$FSTYP

Eryu Guan
2016-06-21T06:54:37Z

On Mon, Jun 20, 2016 at 09:24:32PM +0800, Zorro Lang wrote:
> XFS add more configurations in /sys/fs/xfs recently. For use
> them, this patch add some common functions for:
> 1. "require" a file/dir in /sys/fs/${FSTYP}.
> 2. write a file in /sys/fs/${FSTYP}.
>
> For common use, these functions can be used by other filesystems.
>
> Signed-off-by: Zorro Lang <zlang@redhat.com>
> ---
>
> Hi,
>
> V4 did below changes:
> 1) function name from *_fs_sys_fs to *_fs_sysfs
> 2) use $UMOUNT_PROG to instead of umount
> 3) use _short_dev
> 4) add comments for new functions
> 5) other little changes
>
> Thanks,
> Zorro
>
> common/rc | 42 ++++++++++++++++++++++++++++++++++++++++++
> 1 file changed, 42 insertions(+)
>
> diff --git a/common/rc b/common/rc
> index 51092a0..88c3777 100644
> --- a/common/rc
> +++ b/common/rc
> @@ -3556,6 +3556,48 @@ run_fsx()
> fi
> }
>
> +# Test for the existence of a sysfs entry at /sys/fs/$FSTYP/$DEV/$ENTRY
> +_require_fs_sysfs()
> +{
> + local dev=$1
> + local entry=$2
> + local tmp_mnt=`mktemp -d`
> +
> + if [ ! -b "$dev" -o -z "$entry" ];then
> + _fail "Usage: _require_fs_sysfs <device> <sysfs_path>"
> + fi

Mixed tab and space in above line.

> +
> + local dname=$(_short_dev $dev)
> + _mount -t $FSTYP `_common_dev_mount_options` $dev $tmp_mnt
> + if [ $? -ne 0 ];then
> + rm -f $tmp_mnt
> + _fail "_require_fs_sysfs: could not mount, mkfs first in your test?"

I'd like to see which device failed to mount in error message.

> + elif [ ! -e /sys/fs/${FSTYP}/${dname}/${entry} ];then
> + $UMOUNT_PROG $tmp_mnt
> + rm -f $tmp_mnt
> + _notrun "/sys/fs/${FSTYP}/${dname}/${entry}: No such file or directory"
> + fi
> + $UMOUNT_PROG $tmp_mnt
> + rm -rf $tmp_mnt
> +}
> +
> +# Write "content" into /sys/fs/$FSTYP/$DEV/$ENTRY
> +_set_fs_sysfs_param()

I think we can have a _get_fs_sysfs_param() helper to ensure the value
is correct.

Maybe naming them as _set|get_fs_sysfs_attr()?

Thanks,
Eryu

> +{
> + local dev=$1
> + shift
> + local entry=$1
> + shift
> + local content="$*"
> +
> + if [ ! -b "$dev" -o -z "$entry" -o -z "$content" ];then
> + _fail "Usage: _set_fs_sysfs_param <mounted_device> <entry> <content>"
> + fi
> +
> + local dname=$(_short_dev $dev)
> + echo "$content" > /sys/fs/${FSTYP}/${dname}/${entry}
> +}
> +
> init_rc
>
> ################################################################################
> --
> 2.5.5
>