Currently, ->lru is a way to arrange non-LRU pages and has some
in-kernel users. In order to minimize noticable issues of page
reclaim and cache thrashing under high memory presure, limited
temporary pages were all chained with ->lru and can be reused
during the request. However, it seems that ->lru could be removed
when folio is landing.
Let's use page->private to chain temporary pages for now instead
and transform EROFS formally after the topic of the folio / file
page design is finalized.
Cc: Matthew Wilcox <willy@xxxxxxxxxxxxx>
Cc: Kent Overstreet <kent.overstreet@xxxxxxxxx>
Cc: Chao Yu <chao@xxxxxxxxxx>
Signed-off-by: Gao Xiang <hsiangkao@xxxxxxxxxxxxxxxxx>