[PATCH 21/23] jbd2: Checksum commit blocks
From: Darrick J. Wong <hidden>
Date: 2011-12-14 00:48:38
Also in:
linux-fsdevel, lkml
Subsystem:
filesystems (vfs and infrastructure), journalling layer for block devices (jbd2), the rest · Maintainers:
Alexander Viro, Christian Brauner, "Theodore Ts'o", Jan Kara, Linus Torvalds
Calculate and verify the checksum of commit blocks. In checksum v2, deprecate most of the checksum v1 commit block checksum fields, since each block has its own checksum. Signed-off-by: Darrick J. Wong <redacted> --- fs/jbd2/commit.c | 21 ++++++++++++++++++++- fs/jbd2/recovery.c | 31 +++++++++++++++++++++++++++++++ 2 files changed, 51 insertions(+), 1 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 99dbb9a..ccf0b6f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c@@ -86,6 +86,24 @@ nope: __brelse(bh); } +static void jbd2_commit_block_csum_set(journal_t *j, + struct journal_head *descriptor) +{ + struct commit_header *h; + __u32 csum; + + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + return; + + h = (struct commit_header *)(jh2bh(descriptor)->b_data); + h->h_chksum_type = 0; + h->h_chksum_size = 0; + h->h_chksum[0] = 0; + csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data, + j->j_blocksize); + h->h_chksum[0] = cpu_to_be32(csum); +} + /* * Done it all: now submit the commit record. We should have * cleaned up our previous buffers by now, so if we are in abort
@@ -129,6 +147,7 @@ static int journal_submit_commit_record(journal_t *journal, tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE; tmp->h_chksum[0] = cpu_to_be32(crc32_sum); } + jbd2_commit_block_csum_set(journal, descriptor); JBUFFER_TRACE(descriptor, "submit commit block"); lock_buffer(bh);
@@ -351,7 +370,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) struct blk_plug plug; int csum_size = 0; - if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) csum_size = sizeof(struct jbd2_journal_block_tail); /*
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 513006b..a757d8d 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c@@ -372,6 +372,24 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh, return 0; } +static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) +{ + struct commit_header *h; + __u32 provided, calculated; + + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + return 1; + + h = buf; + provided = h->h_chksum[0]; + h->h_chksum[0] = 0; + calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize); + h->h_chksum[0] = provided; + + provided = be32_to_cpu(provided); + return provided == calculated; +} + static int do_one_pass(journal_t *journal, struct recovery_info *info, enum passtype pass) {
@@ -682,6 +700,19 @@ static int do_one_pass(journal_t *journal, } crc32_sum = ~0; } + if (pass == PASS_SCAN && + !jbd2_commit_block_csum_verify(journal, + bh->b_data)) { + info->end_transaction = next_commit_ID; + + if (!JBD2_HAS_INCOMPAT_FEATURE(journal, + JBD2_FEATURE_INCOMPAT_ASYNC_COMMIT)) { + journal->j_failed_commit = + next_commit_ID; + brelse(bh); + break; + } + } brelse(bh); next_commit_ID++; continue;