From: "Darrick J. Wong" Subject: [PATCH 19/23] jbd2: Checksum revocation blocks Date: Tue, 06 Mar 2012 12:50:14 -0800 Message-ID: <20120306205013.1663.40234.stgit@elm3b70.beaverton.ibm.com> References: <20120306204750.1663.96751.stgit@elm3b70.beaverton.ibm.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit Cc: Sunil Mushran , Martin K Petersen , Greg Freemyer , Amir Goldstein , linux-kernel , Andi Kleen , Mingming Cao , Joel Becker , linux-fsdevel , linux-ext4@vger.kernel.org, Coly Li To: Andreas Dilger , Theodore Tso , "Darrick J. Wong" Return-path: Received: from e38.co.us.ibm.com ([32.97.110.159]:53577 "EHLO e38.co.us.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031309Ab2CFUvk (ORCPT ); Tue, 6 Mar 2012 15:51:40 -0500 Received: from /spool/local by e38.co.us.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Tue, 6 Mar 2012 13:51:39 -0700 In-Reply-To: <20120306204750.1663.96751.stgit@elm3b70.beaverton.ibm.com> Sender: linux-ext4-owner@vger.kernel.org List-ID: Compute and verify revoke blocks inside the journal. Signed-off-by: Darrick J. Wong --- fs/jbd2/recovery.c | 22 ++++++++++++++++++++++ fs/jbd2/revoke.c | 27 ++++++++++++++++++++++++++- 2 files changed, 48 insertions(+), 1 deletions(-) diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index da6d7ba..bfc52cd 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -703,6 +703,25 @@ static int do_one_pass(journal_t *journal, return err; } +static int jbd2_revoke_block_csum_verify(journal_t *j, + void *buf) +{ + struct jbd2_journal_revoke_tail *tail; + __u32 provided, calculated; + + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + return 1; + + tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize - + sizeof(struct jbd2_journal_revoke_tail)); + provided = tail->r_checksum; + tail->r_checksum = 0; + calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); + tail->r_checksum = provided; + + provided = be32_to_cpu(provided); + return provided == calculated; +} /* Scan a revoke record, marking all blocks mentioned as revoked. */ @@ -717,6 +736,9 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh, offset = sizeof(jbd2_journal_revoke_header_t); max = be32_to_cpu(header->r_count); + if (!jbd2_revoke_block_csum_verify(journal, header)) + return -EINVAL; + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) record_len = 8; diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c index 30b2867..53a7544 100644 --- a/fs/jbd2/revoke.c +++ b/fs/jbd2/revoke.c @@ -582,6 +582,7 @@ static void write_one_revoke_record(journal_t *journal, struct jbd2_revoke_record_s *record, int write_op) { + int csum_size = 0; struct journal_head *descriptor; int offset; journal_header_t *header; @@ -596,9 +597,13 @@ static void write_one_revoke_record(journal_t *journal, descriptor = *descriptorp; offset = *offsetp; + /* Do we need to leave space at the end for a checksum? */ + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + csum_size = sizeof(struct jbd2_journal_revoke_tail); + /* Make sure we have a descriptor with space left for the record */ if (descriptor) { - if (offset == journal->j_blocksize) { + if (offset >= journal->j_blocksize - csum_size) { flush_descriptor(journal, descriptor, offset, write_op); descriptor = NULL; } @@ -635,6 +640,24 @@ static void write_one_revoke_record(journal_t *journal, *offsetp = offset; } +static void jbd2_revoke_csum_set(journal_t *j, + struct journal_head *descriptor) +{ + struct jbd2_journal_revoke_tail *tail; + __u32 csum; + + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + return; + + tail = (struct jbd2_journal_revoke_tail *) + (jh2bh(descriptor)->b_data + j->j_blocksize - + sizeof(struct jbd2_journal_revoke_tail)); + tail->r_checksum = 0; + csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data, + j->j_blocksize); + tail->r_checksum = cpu_to_be32(csum); +} + /* * Flush a revoke descriptor out to the journal. If we are aborting, * this is a noop; otherwise we are generating a buffer which needs to @@ -656,6 +679,8 @@ static void flush_descriptor(journal_t *journal, header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data; header->r_count = cpu_to_be32(offset); + jbd2_revoke_csum_set(journal, descriptor); + set_buffer_jwrite(bh); BUFFER_TRACE(bh, "write"); set_buffer_dirty(bh);