netfs: Fault in smaller chunks for non-large folio mappings

As in commit 4e527d58 ("iomap: fault in smaller chunks for non-large
folio mappings"), we can see a performance loss for filesystems
which have not yet been converted to large folios.

Fixes: c38f4e96 ("netfs: Provide func to copy data to pagecache for buffered write")
Signed-off-by: Matthew Wilcox (Oracle) <willy@infradead.org>
Link: https://lore.kernel.org/r/20240527201735.1898381-1-willy@infradead.org


Reviewed-by: Jeff Layton <jlayton@kernel.org>
Signed-off-by: Christian Brauner <brauner@kernel.org>