From 42a7106de636ebf9c0b93d25b4230e14f5f2682e Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 27 May 2012 08:08:24 -0400 Subject: [PATCH] jbd2: checksum revocation blocks Compute and verify revoke blocks inside the journal. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/jbd2/recovery.c | 22 ++++++++++++++++++++++ fs/jbd2/revoke.c | 27 ++++++++++++++++++++++++++- 2 files changed, 48 insertions(+), 1 deletion(-) diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index 980f3d6b5f88..728ecd0705d9 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -706,6 +706,25 @@ 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. */ @@ -720,6 +739,9 @@ 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 6973705d6a3d..f30b80b4ce8b 100644 --- a/fs/jbd2/revoke.c +++ b/fs/jbd2/revoke.c @@ -578,6 +578,7 @@ 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; @@ -592,9 +593,13 @@ 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; } @@ -631,6 +636,24 @@ 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 @@ -652,6 +675,8 @@ 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); -- 2.20.1