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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>
This commit is contained in:
Darrick J. Wong 2012-05-27 08:10:25 -04:00 committed by Theodore Ts'o
parent 3caa487f53
commit 1f56c5890e
2 changed files with 50 additions and 0 deletions
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19
fs/jbd2/commit.c
View File

@ -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);

31
fs/jbd2/recovery.c
View File

@ -375,6 +375,24 @@ 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)
{
@ -685,6 +703,19 @@ 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;