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jbd2: checksum commit blocks

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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;