[parted-devel] [PATCH] libparted: Fail early when detecting nilfs2

[Brian C. Lane]

On Fri, Mar 29, 2024 at 03:39:44PM +0100, Oldřich Jedlička wrote:
> The possibly checked LUKS area might be protected with OPAL HW encryption
> and not yet fully unlocked, so try to detect nilfs2 at the beginning of the
> area first and if that succeeds, detect it at the end of the area. This
> prevents having read errors from the locked area.
> 
> Signed-off-by: Oldřich Jedlička <oldium.pro at gmail.com>
> ---
>  libparted/fs/nilfs2/nilfs2.c | 7 ++++---
>  1 file changed, 4 insertions(+), 3 deletions(-)
> 
> diff --git a/libparted/fs/nilfs2/nilfs2.c b/libparted/fs/nilfs2/nilfs2.c
> index 6204542..40f8567 100644
> --- a/libparted/fs/nilfs2/nilfs2.c
> +++ b/libparted/fs/nilfs2/nilfs2.c
> @@ -118,11 +118,12 @@ nilfs2_probe (PedGeometry* geom)
>  
>  	if (ped_geometry_read(geom, buf, 0, sectors))
>  		sb = (struct nilfs2_super_block*)(buf + 1024);
> +	if (!sb || !is_valid_nilfs_sb(sb))
> +		return NULL;
> +
>  	if (ped_geometry_read(geom, buff2, sb2off, sectors2))
>  		sb2 = (struct nilfs2_super_block*)buff2;
> -
> -	if ((!sb || !is_valid_nilfs_sb(sb)) &&
> -	    (!sb2 || !is_valid_nilfs_sb(sb2)))
> +	if (!sb2 || !is_valid_nilfs_sb(sb2))
>  		return NULL;
>  
>  	/* reserve 4k bytes for secondary superblock */
> -- 
> 2.39.2
> 
> 

Thanks for the patch! And thanks for looking into this, I hadn't had a
chance to try to dig deeper.

Could you update the commit message with a bit more background, most
readers probably don't know what your situation is.

You should also point out that this is a behavior change. Previously it
would fail only if both locations were invalid. In practice I doubt this
really matters since this is just a filesystem probe to populate the
label.

Brian
-- 
Brian C. Lane (PST8PDT) - weldr.io - lorax - parted - pykickstart