On Tue, Feb 11, 2020 at 11:43:18PM -0800, Christoph Hellwig wrote: > On Tue, Feb 11, 2020 at 08:18:29PM -0800, Matthew Wilcox wrote: > > From: "Matthew Wilcox (Oracle)" <willy@xxxxxxxxxxxxx> > > > > The page cache needs to know whether the filesystem supports pages > > > PAGE_SIZE. > > Does it make sense to set this flag on the file_system_type, which > is rather broad scope, or a specific superblock or even inode? > > For some file systems we might require on-disk flags that aren't set > for all instances. I don't see why we'd need on-disk flags or need to control this on a per-inode or per-sb basis. My intent for this flag is to represent whether the filesystem understands large pages; how the file is cached should make no difference to the on-disk layout.