From patchwork Tue Jan 15 05:42:50 2013 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Darrick Wong X-Patchwork-Id: 211996 Return-Path: X-Original-To: patchwork-incoming@ozlabs.org Delivered-To: patchwork-incoming@ozlabs.org Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by ozlabs.org (Postfix) with ESMTP id 1BF942C008F for ; Tue, 15 Jan 2013 16:44:12 +1100 (EST) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752038Ab3AOFn4 (ORCPT ); Tue, 15 Jan 2013 00:43:56 -0500 Received: from userp1040.oracle.com ([156.151.31.81]:40532 "EHLO userp1040.oracle.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750826Ab3AOFny (ORCPT ); Tue, 15 Jan 2013 00:43:54 -0500 Received: from acsinet21.oracle.com (acsinet21.oracle.com [141.146.126.237]) by userp1040.oracle.com (Sentrion-MTA-4.2.2/Sentrion-MTA-4.2.2) with ESMTP id r0F5gsYC021061 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Tue, 15 Jan 2013 05:42:55 GMT Received: from acsmt356.oracle.com (acsmt356.oracle.com [141.146.40.156]) by acsinet21.oracle.com (8.14.4+Sun/8.14.4) with ESMTP id r0F5grEb016597 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=NO); Tue, 15 Jan 2013 05:42:53 GMT Received: from abhmt116.oracle.com (abhmt116.oracle.com [141.146.116.68]) by acsmt356.oracle.com (8.12.11.20060308/8.12.11) with ESMTP id r0F5grgm031226; Mon, 14 Jan 2013 23:42:53 -0600 Received: from localhost (/71.198.22.83) by default (Oracle Beehive Gateway v4.0) with ESMTP ; Mon, 14 Jan 2013 21:42:52 -0800 Subject: [PATCH 2/6] mm: Only enforce stable page writes if the backing device requires it To: axboe@kernel.dk, lucho@ionkov.net, jack@suse.cz, darrick.wong@oracle.com, ericvh@gmail.com, tytso@mit.edu, viro@zeniv.linux.org.uk, rminnich@sandia.gov From: "Darrick J. Wong" Cc: martin.petersen@oracle.com, neilb@suse.de, david@fromorbit.com, gnehzuil.liu@gmail.com, linux-kernel@vger.kernel.org, hch@infradead.org, linux-fsdevel@vger.kernel.org, adilger.kernel@dilger.ca, bharrosh@panasas.com, jlayton@samba.org, linux-ext4@vger.kernel.org, hirofumi@mail.parknet.co.jp Date: Mon, 14 Jan 2013 21:42:50 -0800 Message-ID: <20130115054250.1563.40740.stgit@blackbox.djwong.org> In-Reply-To: <20130115054235.1563.12967.stgit@blackbox.djwong.org> References: <20130115054235.1563.12967.stgit@blackbox.djwong.org> User-Agent: StGit/0.15 MIME-Version: 1.0 X-Source-IP: acsinet21.oracle.com [141.146.126.237] Sender: linux-ext4-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-ext4@vger.kernel.org Create a helper function to check if a backing device requires stable page writes and, if so, performs the necessary wait. Then, make it so that all points in the memory manager that handle making pages writable use the helper function. This should provide stable page write support to most filesystems, while eliminating unnecessary waiting for devices that don't require the feature. Signed-off-by: Darrick J. Wong Reviewed-by: Jan Kara Acked-by: Steven Whitehouse --- fs/buffer.c | 2 +- fs/ext4/inode.c | 2 +- fs/gfs2/file.c | 2 +- fs/nilfs2/file.c | 2 +- include/linux/pagemap.h | 1 + mm/filemap.c | 3 ++- mm/page-writeback.c | 20 ++++++++++++++++++++ 7 files changed, 27 insertions(+), 5 deletions(-) -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html diff --git a/fs/buffer.c b/fs/buffer.c index c017a2d..2981449 100644 --- a/fs/buffer.c +++ b/fs/buffer.c @@ -2359,7 +2359,7 @@ int __block_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf, if (unlikely(ret < 0)) goto out_unlock; set_page_dirty(page); - wait_on_page_writeback(page); + wait_for_stable_page(page); return 0; out_unlock: unlock_page(page); diff --git a/fs/ext4/inode.c b/fs/ext4/inode.c index cbfe13b..cd818d8b 100644 --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -4968,7 +4968,7 @@ int ext4_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) 0, len, NULL, ext4_bh_unmapped)) { /* Wait so that we don't change page under IO */ - wait_on_page_writeback(page); + wait_for_stable_page(page); ret = VM_FAULT_LOCKED; goto out; } diff --git a/fs/gfs2/file.c b/fs/gfs2/file.c index 991ab2d..b9e0ca2 100644 --- a/fs/gfs2/file.c +++ b/fs/gfs2/file.c @@ -483,7 +483,7 @@ out: gfs2_holder_uninit(&gh); if (ret == 0) { set_page_dirty(page); - wait_on_page_writeback(page); + wait_for_stable_page(page); } sb_end_pagefault(inode->i_sb); return block_page_mkwrite_return(ret); diff --git a/fs/nilfs2/file.c b/fs/nilfs2/file.c index 6194688..bec4af6 100644 --- a/fs/nilfs2/file.c +++ b/fs/nilfs2/file.c @@ -126,7 +126,7 @@ static int nilfs_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) nilfs_transaction_commit(inode->i_sb); mapped: - wait_on_page_writeback(page); + wait_for_stable_page(page); out: sb_end_pagefault(inode->i_sb); return block_page_mkwrite_return(ret); diff --git a/include/linux/pagemap.h b/include/linux/pagemap.h index 6da609d..0e38e13 100644 --- a/include/linux/pagemap.h +++ b/include/linux/pagemap.h @@ -414,6 +414,7 @@ static inline void wait_on_page_writeback(struct page *page) } extern void end_page_writeback(struct page *page); +void wait_for_stable_page(struct page *page); /* * Add an arbitrary waiter to a page's wait queue diff --git a/mm/filemap.c b/mm/filemap.c index 83efee7..5577dc8 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -1728,6 +1728,7 @@ int filemap_page_mkwrite(struct vm_area_struct *vma, struct vm_fault *vmf) * see the dirty page and writeprotect it again. */ set_page_dirty(page); + wait_for_stable_page(page); out: sb_end_pagefault(inode->i_sb); return ret; @@ -2274,7 +2275,7 @@ repeat: return NULL; } found: - wait_on_page_writeback(page); + wait_for_stable_page(page); return page; } EXPORT_SYMBOL(grab_cache_page_write_begin); diff --git a/mm/page-writeback.c b/mm/page-writeback.c index 0713bfb..9c5af4d 100644 --- a/mm/page-writeback.c +++ b/mm/page-writeback.c @@ -2289,3 +2289,23 @@ int mapping_tagged(struct address_space *mapping, int tag) return radix_tree_tagged(&mapping->page_tree, tag); } EXPORT_SYMBOL(mapping_tagged); + +/** + * wait_for_stable_page() - wait for writeback to finish, if necessary. + * @page: The page to wait on. + * + * This function determines if the given page is related to a backing device + * that requires page contents to be held stable during writeback. If so, then + * it will wait for any pending writeback to complete. + */ +void wait_for_stable_page(struct page *page) +{ + struct address_space *mapping = page_mapping(page); + struct backing_dev_info *bdi = mapping->backing_dev_info; + + if (!bdi_cap_stable_pages_required(bdi)) + return; + + wait_on_page_writeback(page); +} +EXPORT_SYMBOL_GPL(wait_for_stable_page);