From: Chris Wright Subject: [patch 70/76] jbd2: correctly unescape journal data blocks Date: Fri, 21 Mar 2008 15:44:00 -0700 Message-ID: <20080321224451.150546511@sous-sol.org> References: <20080321224250.144333319@sous-sol.org> Cc: Justin Forbes , Zwane Mwaikambo , "Theodore Ts'o" , Randy Dunlap , Dave Jones , Chuck Wolber , Chris Wedgwood , Michael Krufky , Chuck Ebbert , Domenico Andreoli , torvalds@linux-foundation.org, akpm@linux-foundation.org, alan@lxorguk.ukuu.org.uk, Duane Griffin , Jan Kara , , Greg Kroah-Hartman To: linux-kernel@vger.kernel.org, stable@kernel.org, jejb@kernel.org Return-path: Received: from 216-99-217-87.dsl.aracnet.com ([216.99.217.87]:41345 "EHLO sous-sol.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1762623AbYCUWwc (ORCPT ); Fri, 21 Mar 2008 18:52:32 -0400 Content-Disposition: inline; filename=jbd2-correctly-unescape-journal-data-blocks.patch Sender: linux-ext4-owner@vger.kernel.org List-ID: -stable review patch. If anyone has any objections, please let us know. --------------------- 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 JBD2_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: Signed-off-by: Andrew Morton Signed-off-by: Linus Torvalds Signed-off-by: Chris Wright Signed-off-by: Greg Kroah-Hartman --- fs/jbd2/recovery.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -488,7 +488,7 @@ static int do_one_pass(journal_t *journa memcpy(nbh->b_data, obh->b_data, journal->j_blocksize); if (flags & JBD2_FLAG_ESCAPE) { - *((__be32 *)bh->b_data) = + *((__be32 *)nbh->b_data) = cpu_to_be32(JBD2_MAGIC_NUMBER); } --