From: "Duane Griffin" Subject: [PATCH] jbd2: correctly unescape journal data blocks Date: Sat, 15 Mar 2008 18:49:45 +0000 Message-ID: <1205606985-22645-3-git-send-email-duaneg@dghda.com> References: <1205606985-22645-1-git-send-email-duaneg@dghda.com> <1205606985-22645-2-git-send-email-duaneg@dghda.com> Cc: linux-ext4@vger.kernel.org, duaneg@dghda.com To: sct@redhat.com, akpm@linux-foundation.org Return-path: Received: from kumera.dghda.com ([80.68.90.171]:2841 "EHLO kumera.dghda.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752248AbYCOStx (ORCPT ); Sat, 15 Mar 2008 14:49:53 -0400 In-Reply-To: <1205606985-22645-2-git-send-email-duaneg@dghda.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: 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 --- fs/jbd2/recovery.c | 2 +- 1 files changed, 1 insertions(+), 1 deletions(-) diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 1464113..5d0405a 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -535,7 +535,7 @@ static int do_one_pass(journal_t *journal, 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); } -- 1.5.3.7