From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail138.messagelabs.com (mail138.messagelabs.com [216.82.249.35]) by kanga.kvack.org (Postfix) with ESMTP id ED4ED6B0012 for ; Fri, 27 May 2011 15:23:43 -0400 (EDT) Received: from d03relay02.boulder.ibm.com (d03relay02.boulder.ibm.com [9.17.195.227]) by e35.co.us.ibm.com (8.14.4/8.13.1) with ESMTP id p4RJ6Ih0031529 for ; Fri, 27 May 2011 13:06:19 -0600 Received: from d03av02.boulder.ibm.com (d03av02.boulder.ibm.com [9.17.195.168]) by d03relay02.boulder.ibm.com (8.13.8/8.13.8/NCO v9.1) with ESMTP id p4RJNbDg111326 for ; Fri, 27 May 2011 13:23:37 -0600 Received: from d03av02.boulder.ibm.com (loopback [127.0.0.1]) by d03av02.boulder.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id p4RDN9NJ003094 for ; Fri, 27 May 2011 07:23:10 -0600 Subject: [PATCH 1/2] mm: Wait for writeback when grabbing pages to begin a write From: "Darrick J. Wong" Date: Fri, 27 May 2011 12:23:34 -0700 Message-ID: <20110527192334.32105.99904.stgit@elm3c44.beaverton.ibm.com> In-Reply-To: <20110527192326.32105.34164.stgit@elm3c44.beaverton.ibm.com> References: <20110527192326.32105.34164.stgit@elm3c44.beaverton.ibm.com> MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Sender: owner-linux-mm@kvack.org List-ID: To: Christoph Hellwig , Alexander Viro , "Darrick J. Wong" Cc: Jens Axboe , Theodore Tso , "Martin K. Petersen" , Jeff Layton , Dave Chinner , linux-kernel , Dave Hansen , linux-mm@kvack.org, Chris Mason , Joel Becker , linux-scsi , linux-fsdevel , Jan Kara , linux-ext4@vger.kernel.org, Mingming Cao When grabbing a page for a buffered IO write, the mm should wait for writeback on the page to complete so that the page does not become writable during the IO operation. This change is needed to provide page stability during writes for all filesystems. Signed-off-by: Darrick J. Wong --- mm/filemap.c | 4 +++- 1 files changed, 3 insertions(+), 1 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index bcdc393..dac95a2 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2327,7 +2327,7 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping, repeat: page = find_lock_page(mapping, index); if (page) - return page; + goto found; page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~gfp_notmask); if (!page) @@ -2340,6 +2340,8 @@ repeat: goto repeat; return NULL; } +found: + wait_on_page_writeback(page); return page; } EXPORT_SYMBOL(grab_cache_page_write_begin); -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org