jbd2: make journal y2038 safe

The jbd2 journal stores the commit time in 64-bit seconds and 32-bit
nanoseconds, which avoids an overflow in 2038, but it gets the numbers
from current_kernel_time(), which uses 'long' seconds on 32-bit
architectures.

This simply changes the code to call current_kernel_time64() so
we use 64-bit seconds consistently.
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: Theodore Ts'o <tytso@mit.edu>
Reviewed-by: Jan Kara <jack@suse.cz>
Cc: stable@vger.kernel.org

fs/jbd2/commit.c

@@ -124,7 +124,7 @@ static int journal_submit_commit_record(journal_t *journal,
 	struct commit_header *tmp;
 	struct buffer_head *bh;
 	int ret;
-	struct timespec now = current_kernel_time();
+	struct timespec64 now = current_kernel_time64();
 
 	*cbh = NULL;