Re: [PATCH] f2fs: introduce on-disk layout version checking functionality

[Christoph Hellwig]

On Fri, May 20, 2016 at 11:30:43AM -0700, Viacheslav Dubeyko wrote:
> I am not sure that I follow to your point. The F2FS has "feature" field
> (__le32 feature) into on-disk superblock (struct f2fs_super_block). The
> suggested patch introduces the new F2FS_FEATURE_16TB_SUPPORT flag. And
> it looks like as your comment.

It does, but at the same time you also introduce a major version
superblock
field.

> So, necessary changes in on-disk layout for 16+TB volumes support will
> be incompatible with current available version of F2FS driver. It means
> that, anyway, we need to increase version of on-disk layout (major_ver
> of struct f2fs_super_block). The presence of superblock's version and
> F2FS_FEATURE_16TB_SUPPORT flag will be very useful for consistency
> checking by fsck tool.

Why is the feature not enough for that?