Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756215AbZLIQK7 (ORCPT ); Wed, 9 Dec 2009 11:10:59 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1756178AbZLIQK5 (ORCPT ); Wed, 9 Dec 2009 11:10:57 -0500 Received: from cantor.suse.de ([195.135.220.2]:59036 "EHLO mx1.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756175AbZLIQKz (ORCPT ); Wed, 9 Dec 2009 11:10:55 -0500 Date: Wed, 9 Dec 2009 17:07:38 +0100 From: Jan Kara To: saeed bishara Cc: Jan Kara , LKML , Andrew Morton , linux-ext4@vger.kernel.org Subject: Re: [PATCH 1/3] ext3: Fix data / filesystem corruption when write fails to copy data Message-ID: <20091209160737.GA3690@quack.suse.cz> References: <1259781409-31318-1-git-send-email-jack@suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 4107 Lines: 103 Hi, On Wed 09-12-09 17:42:12, saeed bishara wrote: > I came a cross data corruption bug when using ext3, this patch fixed > it. the bug exists in 2.6.31 and 32. Yes, I plan to send the fix to stable@kernel.org so that it gets fixed in the stable releases for these kernels as well. Thanks for your notice. Honza > On Wed, Dec 2, 2009 at 9:16 PM, Jan Kara wrote: > > When ext3_write_begin fails after allocating some blocks or > > generic_perform_write fails to copy data to write, we truncate blocks already > > instantiated beyond i_size. Although these blocks were never inside i_size, we > > have to truncate pagecache of these blocks so that corresponding buffers get > > unmapped. Otherwise subsequent __block_prepare_write (called because we are > > retrying the write) will find the buffers mapped, not call ->get_block, and > > thus the page will be backed by already freed blocks leading to filesystem and > > data corruption. > > > > CC: linux-ext4@vger.kernel.org > > Reported-by: James Y Knight > > Signed-off-by: Jan Kara > > --- > > ?fs/ext3/inode.c | ? 18 ++++++++++++++---- > > ?1 files changed, 14 insertions(+), 4 deletions(-) > > > > I will take care of merging this patch. I'm just sending it for completeness... > > > > diff --git a/fs/ext3/inode.c b/fs/ext3/inode.c > > index 354ed3b..f9d6937 100644 > > --- a/fs/ext3/inode.c > > +++ b/fs/ext3/inode.c > > @@ -1151,6 +1151,16 @@ static int do_journal_get_write_access(handle_t *handle, > > ? ? ? ?return ext3_journal_get_write_access(handle, bh); > > ?} > > > > +/* > > + * Truncate blocks that were not used by write. We have to truncate the > > + * pagecache as well so that corresponding buffers get properly unmapped. > > + */ > > +static void ext3_truncate_failed_write(struct inode *inode) > > +{ > > + ? ? ? truncate_inode_pages(inode->i_mapping, inode->i_size); > > + ? ? ? ext3_truncate(inode); > > +} > > + > > ?static int ext3_write_begin(struct file *file, struct address_space *mapping, > > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?loff_t pos, unsigned len, unsigned flags, > > ? ? ? ? ? ? ? ? ? ? ? ? ? ? ? ?struct page **pagep, void **fsdata) > > @@ -1209,7 +1219,7 @@ write_begin_failed: > > ? ? ? ? ? ? ? ?unlock_page(page); > > ? ? ? ? ? ? ? ?page_cache_release(page); > > ? ? ? ? ? ? ? ?if (pos + len > inode->i_size) > > - ? ? ? ? ? ? ? ? ? ? ? ext3_truncate(inode); > > + ? ? ? ? ? ? ? ? ? ? ? ext3_truncate_failed_write(inode); > > ? ? ? ?} > > ? ? ? ?if (ret == -ENOSPC && ext3_should_retry_alloc(inode->i_sb, &retries)) > > ? ? ? ? ? ? ? ?goto retry; > > @@ -1304,7 +1314,7 @@ static int ext3_ordered_write_end(struct file *file, > > ? ? ? ?page_cache_release(page); > > > > ? ? ? ?if (pos + len > inode->i_size) > > - ? ? ? ? ? ? ? ext3_truncate(inode); > > + ? ? ? ? ? ? ? ext3_truncate_failed_write(inode); > > ? ? ? ?return ret ? ret : copied; > > ?} > > > > @@ -1330,7 +1340,7 @@ static int ext3_writeback_write_end(struct file *file, > > ? ? ? ?page_cache_release(page); > > > > ? ? ? ?if (pos + len > inode->i_size) > > - ? ? ? ? ? ? ? ext3_truncate(inode); > > + ? ? ? ? ? ? ? ext3_truncate_failed_write(inode); > > ? ? ? ?return ret ? ret : copied; > > ?} > > > > @@ -1383,7 +1393,7 @@ static int ext3_journalled_write_end(struct file *file, > > ? ? ? ?page_cache_release(page); > > > > ? ? ? ?if (pos + len > inode->i_size) > > - ? ? ? ? ? ? ? ext3_truncate(inode); > > + ? ? ? ? ? ? ? ext3_truncate_failed_write(inode); > > ? ? ? ?return ret ? ret : copied; > > ?} > > > > -- > > 1.6.4.2 > > > > -- > > To unsubscribe from this list: send the line "unsubscribe linux-kernel" in > > the body of a message to majordomo@vger.kernel.org > > More majordomo info at ?http://vger.kernel.org/majordomo-info.html > > Please read the FAQ at ?http://www.tux.org/lkml/ > > -- Jan Kara SUSE Labs, CR -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/