... it does that itself (via kmap_atomic())
Signed-off-by: Al Viro <viro@zeniv.linux.org.uk>
                struct page *page = prepared_pages[pg];
                /*
                 * Copy data from userspace to the current page
-                *
-                * Disable pagefault to avoid recursive lock since
-                * the pages are already locked
                 */
-               pagefault_disable();
                copied = iov_iter_copy_from_user_atomic(page, i, offset, count);
-               pagefault_enable();
 
                /* Flush processor's dcache for this page */
                flush_dcache_page(page);
 
                if (mapping_writably_mapped(mapping))
                        flush_dcache_page(page);
 
-               pagefault_disable();
                tmp = iov_iter_copy_from_user_atomic(page, ii, offset, bytes);
-               pagefault_enable();
                flush_dcache_page(page);
 
                mark_page_accessed(page);
 
        char *kaddr;
        size_t copied;
 
-       BUG_ON(!in_atomic());
        kaddr = kmap_atomic(page);
        if (likely(i->nr_segs == 1)) {
                int left;
                if (mapping_writably_mapped(mapping))
                        flush_dcache_page(page);
 
-               pagefault_disable();
                copied = iov_iter_copy_from_user_atomic(page, i, offset, bytes);
-               pagefault_enable();
                flush_dcache_page(page);
 
                mark_page_accessed(page);