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jbd2: checksum data blocks that are stored in the journal

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Calculate and verify checksums of each data block being stored in the journal.

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 08:12:12 -04:00
committed by Theodore Ts'o
parent 1f56c5890e
commit c390087591
3 changed files with 60 additions and 2 deletions
Download Patch File Download Diff File Expand all files Collapse all files

22
fs/jbd2/commit.c
View File

@@ -338,6 +338,26 @@ static void jbd2_descr_block_csum_set(journal_t *j,
tail->t_checksum = cpu_to_be32(csum); tail->t_checksum = cpu_to_be32(csum);
} }
static void jbd2_block_tag_csum_set(journal_t *j, journal_block_tag_t *tag,
struct buffer_head *bh, __u32 sequence)
{
struct page *page = bh->b_page;
__u8 *addr;
__u32 csum;
if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
return;
sequence = cpu_to_be32(sequence);
addr = kmap_atomic(page, KM_USER0);
csum = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
sizeof(sequence));
csum = jbd2_chksum(j, csum, addr + offset_in_page(bh->b_data),
bh->b_size);
kunmap_atomic(addr, KM_USER0);
tag->t_checksum = cpu_to_be32(csum);
}
/* /*
* jbd2_journal_commit_transaction * jbd2_journal_commit_transaction
* *
@@ -669,6 +689,8 @@ void jbd2_journal_commit_transaction(journal_t *journal)
tag = (journal_block_tag_t *) tagp; tag = (journal_block_tag_t *) tagp;
write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr); write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr);
tag->t_flags = cpu_to_be16(tag_flag); tag->t_flags = cpu_to_be16(tag_flag);
jbd2_block_tag_csum_set(journal, tag, jh2bh(new_jh),
commit_transaction->t_tid);
tagp += tag_bytes; tagp += tag_bytes;
space_left -= tag_bytes; space_left -= tag_bytes;

10
fs/jbd2/journal.c
View File

@@ -2097,10 +2097,16 @@ int jbd2_journal_blocks_per_page(struct inode *inode)
*/ */
size_t journal_tag_bytes(journal_t *journal) size_t journal_tag_bytes(journal_t *journal)
{ {
journal_block_tag_t tag;
size_t x = 0;
if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
x += sizeof(tag.t_checksum);
if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT)) if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
return JBD2_TAG_SIZE64; return x + JBD2_TAG_SIZE64;
else else
return JBD2_TAG_SIZE32; return x + JBD2_TAG_SIZE32;
} }
/* /*

30
fs/jbd2/recovery.c
View File

@@ -393,6 +393,23 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf)
return provided == calculated; return provided == calculated;
} }
static int jbd2_block_tag_csum_verify(journal_t *j, journal_block_tag_t *tag,
void *buf, __u32 sequence)
{
__u32 provided, calculated;
if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
return 1;
sequence = cpu_to_be32(sequence);
calculated = jbd2_chksum(j, j->j_csum_seed, (__u8 *)&sequence,
sizeof(sequence));
calculated = jbd2_chksum(j, calculated, buf, j->j_blocksize);
provided = be32_to_cpu(tag->t_checksum);
return provided == cpu_to_be32(calculated);
}
static int do_one_pass(journal_t *journal, static int do_one_pass(journal_t *journal,
struct recovery_info *info, enum passtype pass) struct recovery_info *info, enum passtype pass)
{ {
@@ -569,6 +586,19 @@ static int do_one_pass(journal_t *journal,
goto skip_write; goto skip_write;
} }
/* Look for block corruption */
if (!jbd2_block_tag_csum_verify(
journal, tag, obh->b_data,
be32_to_cpu(tmp->h_sequence))) {
brelse(obh);
success = -EIO;
printk(KERN_ERR "JBD: Invalid "
"checksum recovering "
"block %llu in log\n",
blocknr);
continue;
}
/* Find a buffer for the new /* Find a buffer for the new
* data being restored */ * data being restored */
nbh = __getblk(journal->j_fs_dev, nbh = __getblk(journal->j_fs_dev,