From c390087591dcbecd244c31d979ccdad49ae83364 Mon Sep 17 00:00:00 2001 From: "Darrick J. Wong" Date: Sun, 27 May 2012 08:12:12 -0400 Subject: [PATCH] jbd2: checksum data blocks that are stored in the journal Calculate and verify checksums of each data block being stored in the journal. Signed-off-by: Darrick J. Wong Signed-off-by: "Theodore Ts'o" --- fs/jbd2/commit.c | 22 ++++++++++++++++++++++ fs/jbd2/journal.c | 10 ++++++++-- fs/jbd2/recovery.c | 30 ++++++++++++++++++++++++++++++ 3 files changed, 60 insertions(+), 2 deletions(-) diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c index 16e1fe2a769..216f4299f65 100644 --- a/fs/jbd2/commit.c +++ b/fs/jbd2/commit.c @@ -338,6 +338,26 @@ static void jbd2_descr_block_csum_set(journal_t *j, 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 * @@ -669,6 +689,8 @@ void jbd2_journal_commit_transaction(journal_t *journal) tag = (journal_block_tag_t *) tagp; write_tag_block(tag_bytes, tag, jh2bh(jh)->b_blocknr); 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; space_left -= tag_bytes; diff --git a/fs/jbd2/journal.c b/fs/jbd2/journal.c index 9072f03d30b..e9a3c4c8559 100644 --- a/fs/jbd2/journal.c +++ b/fs/jbd2/journal.c @@ -2097,10 +2097,16 @@ int jbd2_journal_blocks_per_page(struct inode *inode) */ 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)) - return JBD2_TAG_SIZE64; + return x + JBD2_TAG_SIZE64; else - return JBD2_TAG_SIZE32; + return x + JBD2_TAG_SIZE32; } /* diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c index df4a20e7d85..0131e436253 100644 --- a/fs/jbd2/recovery.c +++ b/fs/jbd2/recovery.c @@ -393,6 +393,23 @@ static int jbd2_commit_block_csum_verify(journal_t *j, void *buf) 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, struct recovery_info *info, enum passtype pass) { @@ -569,6 +586,19 @@ static int do_one_pass(journal_t *journal, 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 * data being restored */ nbh = __getblk(journal->j_fs_dev, -- 2.41.0