Return-Path: linux-nfs-owner@vger.kernel.org Received: from mail-pd0-f180.google.com ([209.85.192.180]:58621 "EHLO mail-pd0-f180.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751428AbaLOF1j (ORCPT ); Mon, 15 Dec 2014 00:27:39 -0500 Received: by mail-pd0-f180.google.com with SMTP id w10so10964026pde.11 for ; Sun, 14 Dec 2014 21:27:38 -0800 (PST) From: Omar Sandoval To: Alexander Viro , Andrew Morton , Trond Myklebust , Christoph Hellwig , David Sterba , linux-fsdevel@vger.kernel.org, linux-mm@kvack.org, linux-nfs@vger.kernel.org, linux-kernel@vger.kernel.org Cc: Omar Sandoval Subject: [PATCH 7/8] swap: use direct I/O for SWP_FILE swap_readpage Date: Sun, 14 Dec 2014 21:27:01 -0800 Message-Id: In-Reply-To: References: In-Reply-To: References: Sender: linux-nfs-owner@vger.kernel.org List-ID: On Mon, Nov 17, 2014 at 07:48:17AM -0800, Christoph Hellwig wrote: > With the new iov_iter infrastructure that supprots direct I/O to kernel > pages please get rid of the ->readpage hack first. I'm still utterly > disapoined that this crap ever got merged. Signed-off-by: Omar Sandoval --- mm/page_io.c | 25 +++++++++++++++++++++++-- 1 file changed, 23 insertions(+), 2 deletions(-) diff --git a/mm/page_io.c b/mm/page_io.c index 4741248..956307c 100644 --- a/mm/page_io.c +++ b/mm/page_io.c @@ -346,12 +346,33 @@ int swap_readpage(struct page *page) } if (sis->flags & SWP_FILE) { + struct kiocb kiocb; struct file *swap_file = sis->swap_file; struct address_space *mapping = swap_file->f_mapping; + struct iov_iter to; + struct bio_vec bv = { + .bv_page = page, + .bv_len = PAGE_SIZE, + .bv_offset = 0, + }; + + iov_iter_bvec(&to, ITER_BVEC | READ, &bv, 1, PAGE_SIZE); - ret = mapping->a_ops->readpage(swap_file, page); - if (!ret) + init_sync_kiocb(&kiocb, swap_file); + kiocb.ki_pos = page_file_offset(page); + kiocb.ki_nbytes = PAGE_SIZE; + + ret = mapping->a_ops->direct_IO(READ, &kiocb, &to, + kiocb.ki_pos); + if (ret == PAGE_SIZE) { + SetPageUptodate(page); count_vm_event(PSWPIN); + ret = 0; + } else { + ClearPageUptodate(page); + SetPageError(page); + } + unlock_page(page); return ret; } -- 2.1.3