JBD2: Fix NULL pointer bh->b_data on NUMA box with journal checksumming.
Current journal checksumming patch failed fsstress test on NUMA. The
bh->b_data passed to the crc32_be () function could be NULL pointer,
which caused kernel oops immediately when running fsstress with -o
journal_checksum. It is because the page is part of highmem on NUMA box.
We need to kmap the page before access the bh->b_data to calculate
the checksums.
Signed-off-by: Mingming Cao <cmm@xxxxxxxxxx>
---
fs/jbd2/commit.c | 19 ++++++++++++++++---
1 file changed, 16 insertions(+), 3 deletions(-)
Index: linux-2.6.24-rc1/fs/jbd2/commit.c
===================================================================
--- linux-2.6.24-rc1.orig/fs/jbd2/commit.c 2007-11-01 11:15:08.000000000 -0700
+++ linux-2.6.24-rc1/fs/jbd2/commit.c 2007-11-01 12:27:02.000000000 -0700
@@ -352,6 +352,20 @@ write_out_data:
journal_do_submit_data(wbuf, bufs);
}
+static inline __u32 jbd2_checksum_data(__u32 crc32_sum, struct buffer_head *bh)
+{
+ struct page *page = bh->b_page;
+ char *addr;
+ __u32 checksum;
+
+ addr = kmap(page);
+ checksum = crc32_be(crc32_sum,
+ (void *)(addr + offset_in_page(bh->b_data)), bh->b_size);
+ kunmap(page);
+
+ return checksum;
+}
+
static inline void write_tag_block(int tag_bytes, journal_block_tag_t *tag,
unsigned long long block)
{
@@ -715,9 +729,8 @@ start_journal_io:
*/
if (JBD2_HAS_COMPAT_FEATURE(journal,
JBD2_FEATURE_COMPAT_CHECKSUM)) {
- crc32_sum = crc32_be(crc32_sum,
- (void *)bh->b_data,
- bh->b_size);
+ crc32_sum =
+ jbd2_checksum_data(crc32_sum, bh);
}
lock_buffer(bh);
-
To unsubscribe from this list: send the line "unsubscribe linux-ext4" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
