Hi Christoph, On Wed, Sep 18, 2019 at 11:24:12AM -0700, Christoph Hellwig wrote: > Just as a note of record: I don't think either file system move > is a good idea. erofs still needs a lot of work, especially in > interacting with the mm code like abusing page->mapping.
I know what you mean, that is a known stuff in the TODO list, Z_EROFS_MAPPING_STAGING page->mapping just be used as a temporary page mark since page->private is already pointed to another structure, It's now be marked as an non-movable and anon pseudo mapping and most mm code just skip this case. I think a better way is to use a real address_space structure for page->mapping to point. It's easy to update but I need some time to verify. If I am wrong, please point it out... Thanks, Gao Xiang
