Commit e7c0b599 authored Jul 01, 2016 by Vivek Goyal Committed by Miklos Szeredi Jul 03, 2016

ovl: warn instead of error if d_type is not supported

overlay needs underlying fs to support d_type. Recently I put in a
patch in to detect this condition and started failing mount if
underlying fs did not support d_type.

But this breaks existing configurations over kernel upgrade. Those who
are running docker (partially broken configuration) with xfs not
supporting d_type, are surprised that after kernel upgrade docker does
not run anymore.

https://github.com/docker/docker/issues/22937#issuecomment-229881315



So instead of erroring out, detect broken configuration and warn
about it. This should allow existing docker setups to continue
working after kernel upgrade.

Signed-off-by: Vivek Goyal <vgoyal@redhat.com>
Signed-off-by: Miklos Szeredi <mszeredi@redhat.com>
Fixes: 45aebeaf ("ovl: Ensure upper filesystem supports d_type")
Cc: <stable@vger.kernel.org> 4.6

parent 03bea604

fs/overlayfs/super.c

+7 −5

Original line number	Diff line number	Diff line
		@@ -1082,11 +1082,13 @@ static int ovl_fill_super(struct super_block sb, void data, int silent)
		if (err < 0)
		goto out_put_workdir;

		if (!err) {
		pr_err("overlayfs: upper fs needs to support d_type.\n");
		err = -EINVAL;
		goto out_put_workdir;
		}
		/*
		* We allowed this configuration and don't want to
		* break users over kernel upgrade. So warn instead
		* of erroring out.
		*/
		if (!err)
		pr_warn("overlayfs: upper fs needs to support d_type.\n");
		}
		}