From: "Darrick J. Wong" Subject: [PATCH 48/54] e2fsck: Check descriptor block checksum when recovering journal Date: Tue, 06 Mar 2012 16:03:03 -0800 Message-ID: <20120307000303.11945.26133.stgit@elm3b70.beaverton.ibm.com> References: <20120306235720.11945.30629.stgit@elm3b70.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Sunil Mushran , Amir Goldstein , Andi Kleen , Mingming Cao , Joel Becker , linux-ext4@vger.kernel.org, Coly Li To: Andreas Dilger , Theodore Tso , "Darrick J. Wong" Return-path: Received: from e39.co.us.ibm.com ([32.97.110.160]:43162 "EHLO e39.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031610Ab2CGAEN (ORCPT ); Tue, 6 Mar 2012 19:04:13 -0500 Received: from /spool/local by e39.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 6 Mar 2012 17:04:12 -0700 Received: from d01relay05.pok.ibm.com (d01relay05.pok.ibm.com [9.56.227.237]) by d01dlp03.pok.ibm.com (Postfix) with ESMTP id 420F3C9005C for ; Tue, 6 Mar 2012 19:03:11 -0500 (EST) Received: from d01av04.pok.ibm.com (d01av04.pok.ibm.com [9.56.224.64]) by d01relay05.pok.ibm.com (8.13.8/8.13.8/NCO v10.0) with ESMTP id q2703Bc3224256 for ; Tue, 6 Mar 2012 19:03:11 -0500 Received: from d01av04.pok.ibm.com (loopback [127.0.0.1]) by d01av04.pok.ibm.com (8.14.4/8.13.1/NCO v10.0 AVout) with ESMTP id q27038tF011749 for ; Tue, 6 Mar 2012 19:03:11 -0500 In-Reply-To: <20120306235720.11945.30629.stgit@elm3b70.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Verify the descriptor block checksum when recovering a journal. Signed-off-by: Darrick J. Wong --- e2fsck/recovery.c | 39 ++++++++++++++++++++++++++++++++++++++- 1 files changed, 38 insertions(+), 1 deletions(-) diff --git a/e2fsck/recovery.c b/e2fsck/recovery.c index 60c8ceb..f76e7d8 100644 --- a/e2fsck/recovery.c +++ b/e2fsck/recovery.c @@ -174,6 +174,27 @@ static int jread(struct buffer_head **bhp, journal_t *journal, return 0; } +static int jbd2_descr_block_csum_verify(journal_t *j, + void *buf) +{ + struct journal_block_tail *tail; + __u32 provided, calculated; + + if (!JFS_HAS_INCOMPAT_FEATURE(j, JFS_FEATURE_INCOMPAT_CSUM_V2)) + return 1; + + tail = (struct journal_block_tail *)(buf + j->j_blocksize - + sizeof(struct journal_block_tail)); + provided = tail->t_checksum; + tail->t_checksum = 0; + calculated = ext2fs_crc32c_le(~0, j->j_superblock->s_uuid, + sizeof(j->j_superblock->s_uuid)); + calculated = ext2fs_crc32c_le(calculated, buf, j->j_blocksize); + tail->t_checksum = provided; + + provided = ext2fs_be32_to_cpu(provided); + return provided == calculated; +} /* * Count the number of in-use tags in a journal descriptor block. @@ -186,6 +207,9 @@ static int count_tags(journal_t *journal, struct buffer_head *bh) int nr = 0, size = journal->j_blocksize; int tag_bytes = journal_tag_bytes(journal); + if (JFS_HAS_INCOMPAT_FEATURE(journal, JFS_FEATURE_INCOMPAT_CSUM_V2)) + size -= sizeof(struct journal_block_tail); + tagp = &bh->b_data[sizeof(journal_header_t)]; while ((tagp - bh->b_data + tag_bytes) <= size) { @@ -364,6 +388,7 @@ static int do_one_pass(journal_t *journal, int blocktype; int tag_bytes = journal_tag_bytes(journal); __u32 crc32_sum = ~0; /* Transactional Checksums */ + int descr_csum_size = 0; /* Precompute the maximum metadata descriptors in a descriptor block */ int MAX_BLOCKS_PER_DESC; @@ -454,6 +479,18 @@ static int do_one_pass(journal_t *journal, switch(blocktype) { case JFS_DESCRIPTOR_BLOCK: + /* Verify checksum first */ + if (JFS_HAS_INCOMPAT_FEATURE(journal, + JFS_FEATURE_INCOMPAT_CSUM_V2)) + descr_csum_size = + sizeof(struct journal_block_tail); + if (descr_csum_size > 0 && + !jbd2_descr_block_csum_verify(journal, + bh->b_data)) { + err = -EIO; + goto failed; + } + /* If it is a valid descriptor block, replay it * in pass REPLAY; if journal_checksums enabled, then * calculate checksums in PASS_SCAN, otherwise, @@ -484,7 +521,7 @@ static int do_one_pass(journal_t *journal, tagp = &bh->b_data[sizeof(journal_header_t)]; while ((tagp - bh->b_data + tag_bytes) - <= journal->j_blocksize) { + <= journal->j_blocksize - descr_csum_size) { unsigned long io_block; tag = (journal_block_tag_t *) tagp;