jbd2: checksum commit blocks

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 <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>

1 files changed, 19 insertions, 0 deletions

diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 5d505cfd21c2..16e1fe2a769f 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -85,6 +85,24 @@ 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
@@ -128,6 +146,7 @@ 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);