From: "Darrick J. Wong" Subject: [PATCH v3 3/3] mm: Wait for writeback when grabbing pages to begin a write Date: Wed, 4 May 2011 10:42:27 -0700 Message-ID: <20110504174227.GH20579@tux1.beaverton.ibm.com> References: <20110321164305.GC7153@quack.suse.cz> <20110406232938.GF1110@tux1.beaverton.ibm.com> <20110407165700.GB7363@quack.suse.cz> <20110408203135.GH1110@tux1.beaverton.ibm.com> <20110411124229.47bc28f6@corrin.poochiereds.net> <1302543595-sup-4352@think> <1302569212.2580.13.camel@mingming-laptop> <20110412005719.GA23077@infradead.org> <1302742128.2586.274.camel@mingming-laptop> <20110422000226.GA22189@tux1.beaverton.ibm.com> Reply-To: djwong@us.ibm.com Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Christoph Hellwig , Chris Mason , Jeff Layton , Jan Kara , Dave Chinner , Joel Becker , "Martin K. Petersen" , Jens Axboe , linux-kernel , linux-fsdevel , Mingming Cao , linux-scsi , Dave Hansen , linux-mm@kvack.org, linux-ext4 To: "Theodore Ts'o" Return-path: Content-Disposition: inline In-Reply-To: <20110422000226.GA22189@tux1.beaverton.ibm.com> Sender: linux-kernel-owner@vger.kernel.org List-Id: linux-ext4.vger.kernel.org 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. Signed-off-by: Darrick J. Wong --- mm/filemap.c | 5 ++++- 1 files changed, 4 insertions(+), 1 deletions(-) diff --git a/mm/filemap.c b/mm/filemap.c index c641edf..c22675f 100644 --- a/mm/filemap.c +++ b/mm/filemap.c @@ -2287,8 +2287,10 @@ struct page *grab_cache_page_write_begin(struct address_space *mapping, gfp_notmask = __GFP_FS; repeat: page = find_lock_page(mapping, index); - if (page) + if (page) { + wait_on_page_writeback(page); return page; + } page = __page_cache_alloc(mapping_gfp_mask(mapping) & ~gfp_notmask); if (!page) @@ -2301,6 +2303,7 @@ repeat: goto repeat; return NULL; } + wait_on_page_writeback(page); return page; } EXPORT_SYMBOL(grab_cache_page_write_begin);