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| author | Darrick J. Wong <djwong@us.ibm.com> | 2012-05-27 12:10:22 (GMT) |
|---|---|---|
| committer | Theodore Ts'o <tytso@mit.edu> | 2012-05-27 12:10:22 (GMT) |
| commit | 3caa487f53f65fd1e3950a6b6ae1709e6c43b334 (patch) | |
| tree | 02ee3f18422d9ffed974eb1019e98b2ee1ade01c /fs/jbd2/commit.c | |
| parent | 42a7106de636ebf9c0b93d25b4230e14f5f2682e (diff) | |
| download | linux-3caa487f53f65fd1e3950a6b6ae1709e6c43b334.tar.xz | |
jbd2: checksum descriptor blocks
Calculate and verify a checksum of each descriptor block.
Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
Signed-off-by: "Theodore Ts'o" <tytso@mit.edu>
Diffstat (limited to 'fs/jbd2/commit.c')
| -rw-r--r-- | fs/jbd2/commit.c | 25 |
1 files changed, 24 insertions, 1 deletions
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 69d7803..5d505cf 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -301,6 +301,24 @@ static void write_tag_block(int tag_bytes, journal_block_tag_t *tag, tag->t_blocknr_high = cpu_to_be32((block >> 31) >> 1); } +static void jbd2_descr_block_csum_set(journal_t *j, + struct journal_head *descriptor) +{ + struct jbd2_journal_block_tail *tail; + __u32 csum; + + if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + return; + + tail = (struct jbd2_journal_block_tail *) + (jh2bh(descriptor)->b_data + j->j_blocksize - + sizeof(struct jbd2_journal_block_tail)); + tail->t_checksum = 0; + csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data, + j->j_blocksize); + tail->t_checksum = cpu_to_be32(csum); +} + /* * jbd2_journal_commit_transaction * @@ -334,6 +352,10 @@ void jbd2_journal_commit_transaction(journal_t *journal) unsigned long first_block; tid_t first_tid; int update_tail; + int csum_size = 0; + + if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2)) + csum_size = sizeof(struct jbd2_journal_block_tail); /* * First job: lock down the current transaction and wait for @@ -643,7 +665,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) if (bufs == journal->j_wbufsize || commit_transaction->t_buffers == NULL || - space_left < tag_bytes + 16) { + space_left < tag_bytes + 16 + csum_size) { jbd_debug(4, "JBD2: Submit %d IOs\n", bufs); @@ -653,6 +675,7 @@ void jbd2_journal_commit_transaction(journal_t *journal) tag->t_flags |= cpu_to_be16(JBD2_FLAG_LAST_TAG); + jbd2_descr_block_csum_set(journal, descriptor); start_journal_io: for (i = 0; i < bufs; i++) { struct buffer_head *bh = wbuf[i]; |