From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sun, 5 May 2002 16:52:13 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sun, 5 May 2002 16:52:12 -0400 Received: from parcelfarce.linux.theplanet.co.uk ([195.92.249.252]:40969 "EHLO www.linux.org.uk") by vger.kernel.org with ESMTP id ; Sun, 5 May 2002 16:52:09 -0400 Message-ID: <3CD59C04.350E191B@zip.com.au> Date: Sun, 05 May 2002 13:54:28 -0700 From: Andrew Morton X-Mailer: Mozilla 4.79 [en] (X11; U; Linux 2.4.19-pre4 i686) X-Accept-Language: en MIME-Version: 1.0 To: Linus Torvalds CC: lkml Subject: [patch 3/10] Allow truncate to discard unmapped buffers Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org The buffer state "uptodate, dirty, unmapped" is legal. It occurs when a mapped page with attached buffers which is over a hole is dirtied. So discard_buffer() needs to be able to discard those buffers as well; otherwise the page ends up clean, with dirty buffers and is unfreeable. ===================================== --- 2.5.13/fs/buffer.c~truncate-leak Sun May 5 13:32:00 2002 +++ 2.5.13-akpm/fs/buffer.c Sun May 5 13:32:37 2002 @@ -1091,17 +1091,15 @@ EXPORT_SYMBOL(set_bh_page); /* * Called when truncating a buffer on a page completely. */ -static void discard_buffer(struct buffer_head * bh) +static /* inline */ void discard_buffer(struct buffer_head * bh) { - if (buffer_mapped(bh)) { - clear_buffer_dirty(bh); - lock_buffer(bh); - bh->b_bdev = NULL; - clear_buffer_mapped(bh); - clear_buffer_req(bh); - clear_buffer_new(bh); - unlock_buffer(bh); - } + lock_buffer(bh); + clear_buffer_dirty(bh); + bh->b_bdev = NULL; + clear_buffer_mapped(bh); + clear_buffer_req(bh); + clear_buffer_new(bh); + unlock_buffer(bh); } /** --- 2.5.13/fs/jbd/transaction.c~truncate-leak Sun May 5 13:32:00 2002 +++ 2.5.13-akpm/fs/jbd/transaction.c Sun May 5 13:32:37 2002 @@ -1587,7 +1587,7 @@ static int __journal_try_to_free_buffer( goto out; } - if (!buffer_uptodate(bh)) + if (!buffer_uptodate(bh)) /* AKPM: why? */ goto out; if (jh->b_next_transaction != 0) @@ -1775,9 +1775,6 @@ static int journal_unmap_buffer(journal_ BUFFER_TRACE(bh, "entry"); - if (!buffer_mapped(bh)) - return 1; - /* It is safe to proceed here without the * journal_datalist_spinlock because the buffers cannot be * stolen by try_to_free_buffers as long as we are holding the