The CRC32c polynomial provides better error detection and can be hardware
accelerated on certain machines. To that end, add support for it to jbd2.
Signed-off-by: Darrick J. Wong <djwong@xxxxxxxxxx>
---
fs/jbd2/Kconfig | 1 +
fs/jbd2/commit.c | 6 +++---
fs/jbd2/recovery.c | 20 +++++++++++++++++---
include/linux/jbd2.h | 1 +
4 files changed, 22 insertions(+), 6 deletions(-)
diff --git a/fs/jbd2/Kconfig b/fs/jbd2/Kconfig
index f32f346..40a126b 100644
--- a/fs/jbd2/Kconfig
+++ b/fs/jbd2/Kconfig
@@ -1,6 +1,7 @@
config JBD2
tristate
select CRC32
+ select LIBCRC32C
help
This is a generic journaling layer for block devices that support
both 32-bit and 64-bit block numbers. It is currently used by
diff --git a/fs/jbd2/commit.c b/fs/jbd2/commit.c
index eef6979..00387be 100644
--- a/fs/jbd2/commit.c
+++ b/fs/jbd2/commit.c
@@ -21,7 +21,7 @@
#include <linux/mm.h>
#include <linux/pagemap.h>
#include <linux/jiffies.h>
-#include <linux/crc32.h>
+#include <linux/crc32c.h>
#include <linux/writeback.h>
#include <linux/backing-dev.h>
#include <linux/bio.h>
@@ -125,7 +125,7 @@ static int journal_submit_commit_record(journal_t *journal,
if (JBD2_HAS_COMPAT_FEATURE(journal,
JBD2_FEATURE_COMPAT_CHECKSUM)) {
- tmp->h_chksum_type = JBD2_CRC32_CHKSUM;
+ tmp->h_chksum_type = JBD2_CRC32C_CHKSUM;
tmp->h_chksum_size = JBD2_CRC32_CHKSUM_SIZE;
tmp->h_chksum[0] = cpu_to_be32(crc32_sum);
}
@@ -287,7 +287,7 @@ static __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
__u32 checksum;
addr = kmap_atomic(page, KM_USER0);
- checksum = crc32_be(crc32_sum,
+ checksum = crc32c_le(crc32_sum,
(void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
kunmap_atomic(addr, KM_USER0);
diff --git a/fs/jbd2/recovery.c b/fs/jbd2/recovery.c
index 1cad869..4bab4dd 100644
--- a/fs/jbd2/recovery.c
+++ b/fs/jbd2/recovery.c
@@ -21,6 +21,7 @@
#include <linux/jbd2.h>
#include <linux/errno.h>
#include <linux/crc32.h>
+#include <linux/crc32c.h>
#endif
/*
@@ -323,7 +324,8 @@ static inline unsigned long long read_tag_block(int tag_bytes, journal_block_tag
* descriptor block.
*/
static int calc_chksums(journal_t *journal, struct buffer_head *bh,
- unsigned long *next_log_block, __u32 *crc32_sum)
+ unsigned long *next_log_block, __u32 *crc32_sum,
+ __u32 *crc32c_sum)
{
int i, num_blks, err;
unsigned long io_block;
@@ -332,6 +334,7 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh,
num_blks = count_tags(journal, bh);
/* Calculate checksum of the descriptor block. */
*crc32_sum = crc32_be(*crc32_sum, (void *)bh->b_data, bh->b_size);
+ *crc32c_sum = crc32c_le(*crc32c_sum, (void *)bh->b_data, bh->b_size);
for (i = 0; i < num_blks; i++) {
io_block = (*next_log_block)++;
@@ -344,6 +347,9 @@ static int calc_chksums(journal_t *journal, struct buffer_head *bh,
} else {
*crc32_sum = crc32_be(*crc32_sum, (void *)obh->b_data,
obh->b_size);
+ *crc32c_sum = crc32c_le(*crc32c_sum,
+ (void *)obh->b_data,
+ obh->b_size);
}
put_bh(obh);
}
@@ -363,6 +369,7 @@ static int do_one_pass(journal_t *journal,
int blocktype;
int tag_bytes = journal_tag_bytes(journal);
__u32 crc32_sum = ~0; /* Transactional Checksums */
+ __u32 crc32c_sum = ~0; /* Transactional Checksums */
/*
* First thing is to establish what we expect to find in the log
@@ -459,7 +466,8 @@ static int do_one_pass(journal_t *journal,
!info->end_transaction) {
if (calc_chksums(journal, bh,
&next_log_block,
- &crc32_sum)) {
+ &crc32_sum,
+ &crc32c_sum)) {
put_bh(bh);
break;
}
@@ -617,7 +625,12 @@ static int do_one_pass(journal_t *journal,
cbh->h_chksum_type == JBD2_CRC32_CHKSUM &&
cbh->h_chksum_size ==
JBD2_CRC32_CHKSUM_SIZE)
- chksum_seen = 1;
+ chksum_seen = 1;
+ else if (crc32c_sum == found_chksum &&
+ cbh->h_chksum_type == JBD2_CRC32C_CHKSUM &&
+ cbh->h_chksum_size ==
+ JBD2_CRC32_CHKSUM_SIZE)
+ chksum_seen = 1;
else if (!(cbh->h_chksum_type == 0 &&
cbh->h_chksum_size == 0 &&
found_chksum == 0 &&
@@ -646,6 +659,7 @@ static int do_one_pass(journal_t *journal,
}
}
crc32_sum = ~0;
+ crc32c_sum = ~0;
}
brelse(bh);
next_commit_ID++;
diff --git a/include/linux/jbd2.h b/include/linux/jbd2.h
index 38f307b..de3ec23 100644
--- a/include/linux/jbd2.h
+++ b/include/linux/jbd2.h
@@ -147,6 +147,7 @@ typedef struct journal_header_s
#define JBD2_CRC32_CHKSUM 1
#define JBD2_MD5_CHKSUM 2
#define JBD2_SHA1_CHKSUM 3
+#define JBD2_CRC32C_CHKSUM 4
#define JBD2_CRC32_CHKSUM_SIZE 4
--
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