From: akpm@linux-foundation.org Subject: [patch 18/35] jbd: correctly unescape journal data blocks Date: Wed, 19 Mar 2008 17:00:53 -0700 Message-ID: <200803200000.m2K00rVf011844@imap1.linux-foundation.org> Cc: akpm@linux-foundation.org, duaneg@dghda.com, jack@suse.cz, linux-ext4@vger.kernel.org, stable@kernel.org To: torvalds@linux-foundation.org Return-path: Received: from smtp1.linux-foundation.org ([140.211.169.13]:53575 "EHLO smtp1.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S966217AbYCTALv (ORCPT ); Wed, 19 Mar 2008 20:11:51 -0400 Sender: linux-ext4-owner@vger.kernel.org List-ID: From: "Duane Griffin" Fix a long-standing typo (predating git) that will cause data corruption if a journal data block needs unescaping. At the moment the wrong buffer head's data is being unescaped. To test this case mount a filesystem with data=journal, start creating and deleting a bunch of files containing only JFS_MAGIC_NUMBER (0xc03b3998), then pull the plug on the device. Without this patch the files will contain zeros instead of the correct data after recovery. Signed-off-by: Duane Griffin Acked-by: Jan Kara Cc: Cc: Signed-off-by: Andrew Morton --- fs/jbd/recovery.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff -puN fs/jbd/recovery.c~jbd-correctly-unescape-journal-data-blocks fs/jbd/recovery.c --- a/fs/jbd/recovery.c~jbd-correctly-unescape-journal-data-blocks +++ a/fs/jbd/recovery.c @@ -478,7 +478,7 @@ static int do_one_pass(journal_t *journa memcpy(nbh->b_data, obh->b_data, journal->j_blocksize); if (flags & JFS_FLAG_ESCAPE) { - *((__be32 *)bh->b_data) = + *((__be32 *)nbh->b_data) = cpu_to_be32(JFS_MAGIC_NUMBER); } _