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Date: Mon, 28 Nov 2011 15:28:43 -0800
From: "Darrick J. Wong" <djwong@...ibm.com>
To: Andreas Dilger <adilger.kernel@...ger.ca>,
Theodore Tso <tytso@....edu>,
"Darrick J. Wong" <djwong@...ibm.com>
Cc: Sunil Mushran <sunil.mushran@...cle.com>,
Martin K Petersen <martin.petersen@...cle.com>,
Greg Freemyer <greg.freemyer@...il.com>,
Amir Goldstein <amir73il@...il.com>,
linux-kernel <linux-kernel@...r.kernel.org>,
Andi Kleen <andi@...stfloor.org>,
Mingming Cao <cmm@...ibm.com>,
Joel Becker <jlbec@...lplan.org>,
linux-fsdevel <linux-fsdevel@...r.kernel.org>,
linux-ext4@...r.kernel.org, Coly Li <colyli@...il.com>
Subject: [PATCH 21/22] 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@...ibm.com>
---
fs/jbd2/commit.c | 21 ++++++++++++++++++++-
fs/jbd2/recovery.c | 31 +++++++++++++++++++++++++++++++
include/linux/jbd2.h | 11 +++++++++++
3 files changed, 62 insertions(+), 1 deletions(-)
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index 229d5dc..e083e55 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -86,6 +86,24 @@ 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_uuid_csum, 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
@@ -129,6 +147,7 @@ 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);
@@ -351,7 +370,7 @@ void jbd2_journal_commit_transaction(journal_t *journal)
struct blk_plug plug;
int csum_size = 0;
- if (JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
csum_size = sizeof(struct jbd2_journal_block_tail);
/*
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 7bf250a..173e543 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -372,6 +372,24 @@ 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_uuid_csum, 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)
{
@@ -682,6 +700,19 @@ 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;
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 9d28938..d948ddf 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -155,6 +155,17 @@ typedef struct journal_header_s
#define JBD2_CHECKSUM_BYTES (32 / sizeof(u32))
/*
* Commit block header for storing transactional checksums:
+ *
+ * NOTE: If FEATURE_COMPAT_CHECKSUM (checksum v1) is set, the h_chksum*
+ * fields are used to store a checksum of the descriptor and data blocks.
+ *
+ * If FEATURE_INCOMPAT_CSUM_V2 (checksum v2) is set, then the h_chksum
+ * field is used to store crc32c(uuid+commit_block). Each journal metadata
+ * block gets its own checksum, and data block checksums are stored in
+ * journal_block_tag (in the descriptor). The other h_chksum* fields are
+ * not used.
+ *
+ * Checksum v1 and v2 are mutually exclusive features.
*/
struct commit_header {
__be32 h_magic;
--
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