lkml.org 
[lkml]   [2012]   [Jan]   [7]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
Patch in this message
/
Subject[PATCH 19/23] jbd2: Checksum revocation blocks
From
Date
Compute and verify revoke blocks inside the journal.

Signed-off-by: Darrick J. Wong <djwong@us.ibm.com>
---
fs/jbd2/recovery.c | 22 ++++++++++++++++++++++
fs/jbd2/revoke.c | 27 ++++++++++++++++++++++++++-
2 files changed, 48 insertions(+), 1 deletions(-)

diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index da6d7ba..bfc52cd 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -703,6 +703,25 @@ static int do_one_pass(journal_t *journal,
return err;
}

+static int jbd2_revoke_block_csum_verify(journal_t *j,
+ void *buf)
+{
+ struct jbd2_journal_revoke_tail *tail;
+ __u32 provided, calculated;
+
+ if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ return 1;
+
+ tail = (struct jbd2_journal_revoke_tail *)(buf + j->j_blocksize -
+ sizeof(struct jbd2_journal_revoke_tail));
+ provided = tail->r_checksum;
+ tail->r_checksum = 0;
+ calculated = jbd2_chksum(j, j->j_csum_seed, buf, j->j_blocksize);
+ tail->r_checksum = provided;
+
+ provided = be32_to_cpu(provided);
+ return provided == calculated;
+}

/* Scan a revoke record, marking all blocks mentioned as revoked. */

@@ -717,6 +736,9 @@ static int scan_revoke_records(journal_t *journal, struct buffer_head *bh,
offset = sizeof(jbd2_journal_revoke_header_t);
max = be32_to_cpu(header->r_count);

+ if (!jbd2_revoke_block_csum_verify(journal, header))
+ return -EINVAL;
+
if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_64BIT))
record_len = 8;

diff --git a/fs/jbd2/revoke.c b/fs/jbd2/revoke.c
index 69fd935..a197ba5 100644
--- a/fs/jbd2/revoke.c
+++ b/fs/jbd2/revoke.c
@@ -548,6 +548,7 @@ static void write_one_revoke_record(journal_t *journal,
struct jbd2_revoke_record_s *record,
int write_op)
{
+ int csum_size = 0;
struct journal_head *descriptor;
int offset;
journal_header_t *header;
@@ -562,9 +563,13 @@ static void write_one_revoke_record(journal_t *journal,
descriptor = *descriptorp;
offset = *offsetp;

+ /* Do we need to leave space at the end for a checksum? */
+ if (JBD2_HAS_INCOMPAT_FEATURE(journal, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ csum_size = sizeof(struct jbd2_journal_revoke_tail);
+
/* Make sure we have a descriptor with space left for the record */
if (descriptor) {
- if (offset == journal->j_blocksize) {
+ if (offset >= journal->j_blocksize - csum_size) {
flush_descriptor(journal, descriptor, offset, write_op);
descriptor = NULL;
}
@@ -601,6 +606,24 @@ static void write_one_revoke_record(journal_t *journal,
*offsetp = offset;
}

+static void jbd2_revoke_csum_set(journal_t *j,
+ struct journal_head *descriptor)
+{
+ struct jbd2_journal_revoke_tail *tail;
+ __u32 csum;
+
+ if (!JBD2_HAS_INCOMPAT_FEATURE(j, JBD2_FEATURE_INCOMPAT_CSUM_V2))
+ return;
+
+ tail = (struct jbd2_journal_revoke_tail *)
+ (jh2bh(descriptor)->b_data + j->j_blocksize -
+ sizeof(struct jbd2_journal_revoke_tail));
+ tail->r_checksum = 0;
+ csum = jbd2_chksum(j, j->j_csum_seed, jh2bh(descriptor)->b_data,
+ j->j_blocksize);
+ tail->r_checksum = cpu_to_be32(csum);
+}
+
/*
* Flush a revoke descriptor out to the journal. If we are aborting,
* this is a noop; otherwise we are generating a buffer which needs to
@@ -622,6 +645,8 @@ static void flush_descriptor(journal_t *journal,

header = (jbd2_journal_revoke_header_t *) jh2bh(descriptor)->b_data;
header->r_count = cpu_to_be32(offset);
+ jbd2_revoke_csum_set(journal, descriptor);
+
set_buffer_jwrite(bh);
BUFFER_TRACE(bh, "write");
set_buffer_dirty(bh);


\
 
 \ /
  Last update: 2012-01-07 09:33    [W:0.280 / U:0.872 seconds]
©2003-2014 Jasper Spaans. Advertise on this site