The callee force_page_cache_readahead() already does this and unlike
do_readahead(), force_page_cache_readahead() remembers to check for
->readpages() as well.
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
 do_readahead(struct address_space *mapping, struct file *filp,
             pgoff_t index, unsigned long nr)
 {
-       if (!mapping || !mapping->a_ops || !mapping->a_ops->readpage)
+       if (!mapping || !mapping->a_ops)
                return -EINVAL;
 
        force_page_cache_readahead(mapping, filp, index, nr);