From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758013AbZFJDtM (ORCPT ); Tue, 9 Jun 2009 23:49:12 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757712AbZFJDhK (ORCPT ); Tue, 9 Jun 2009 23:37:10 -0400 Received: from kroah.org ([198.145.64.141]:57535 "EHLO coco.kroah.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757927AbZFJDhH (ORCPT ); Tue, 9 Jun 2009 23:37:07 -0400 X-Mailbox-Line: From greg@blue.kroah.org Tue Jun 9 17:23:53 2009 Message-Id: <20090610002352.821983080@blue.kroah.org> User-Agent: quilt/0.48-1 Date: Tue, 09 Jun 2009 17:14:25 -0700 From: Greg KH To: linux-kernel@vger.kernel.org, stable@kernel.org Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , Willy Tarreau , Rodrigo Rubira Branco , Jake Edge , Eugene Teo , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, linux-ext4@vger.kernel.org, "Aneesh Kumar K.V" , Greg Kroah-Hartman Subject: [patch 57/60] ext4: Fix sub-block zeroing for writes into preallocated extents References: <20090610001328.251476848@blue.kroah.org> Content-Disposition: inline; filename=ext4-fix-sub-block-zeroing-for-writes-into-preallocated-extents.patch In-Reply-To: <20090610032135.GA19346@kroah.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org -stable review patch. If anyone has any objections, please let us know. ------------------ From: Aneesh Kumar K.V (cherry picked from commit 9c1ee184a30394e54165fa4c15923cabd952c106) We need to mark the buffer_head mapping preallocated space as new during write_begin. Otherwise we don't zero out the page cache content properly for a partial write. This will cause file corruption with preallocation. Now that we mark the buffer_head new we also need to have a valid buffer_head blocknr so that unmap_underlying_metadata() unmaps the correct block. Signed-off-by: Aneesh Kumar K.V Signed-off-by: "Theodore Ts'o" Signed-off-by: Greg Kroah-Hartman --- fs/ext4/extents.c | 2 ++ fs/ext4/inode.c | 7 +++++++ 2 files changed, 9 insertions(+) --- a/fs/ext4/extents.c +++ b/fs/ext4/extents.c @@ -2670,6 +2670,8 @@ int ext4_ext_get_blocks(handle_t *handle if (allocated > max_blocks) allocated = max_blocks; set_buffer_unwritten(bh_result); + bh_result->b_bdev = inode->i_sb->s_bdev; + bh_result->b_blocknr = newblock; goto out2; } --- a/fs/ext4/inode.c +++ b/fs/ext4/inode.c @@ -2131,6 +2131,13 @@ static int ext4_da_get_block_prep(struct set_buffer_delay(bh_result); } else if (ret > 0) { bh_result->b_size = (ret << inode->i_blkbits); + /* + * With sub-block writes into unwritten extents + * we also need to mark the buffer as new so that + * the unwritten parts of the buffer gets correctly zeroed. + */ + if (buffer_unwritten(bh_result)) + set_buffer_new(bh_result); ret = 0; }