1 files changed, 37 insertions, 4 deletions

diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index 384c6c469661..b0f4ef77fa70 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -31,18 +31,51 @@ struct xfs_log_vec {
 #define XFS_LOG_VEC_ORDERED	(-1)
 
 static inline void *
-xlog_copy_iovec(struct xfs_log_iovec **vecp, uint type, void *data, int len)
+xlog_prepare_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+		uint type)
 {
 	struct xfs_log_iovec *vec = *vecp;
 
+	if (vec) {
+		ASSERT(vec - lv->lv_iovecp < lv->lv_niovecs);
+		vec++;
+	} else {
+		vec = &lv->lv_iovecp[0];
+	}
+
 	vec->i_type = type;
-	vec->i_addr = data;
-	vec->i_len = len;
+	vec->i_addr = lv->lv_buf + lv->lv_buf_len;
+
+	ASSERT(IS_ALIGNED((unsigned long)vec->i_addr, sizeof(uint64_t)));
 
-	*vecp = vec + 1;
+	*vecp = vec;
 	return vec->i_addr;
 }
 
+static inline void
+xlog_finish_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec *vec, int len)
+{
+	/*
+	 * We need to make sure the next buffer is naturally aligned for the
+	 * biggest basic data type we put into it.  We already accounted for
+	 * this when sizing the buffer.
+	 */
+	lv->lv_buf_len += round_up(len, sizeof(uint64_t));
+	vec->i_len = len;
+}
+
+static inline void *
+xlog_copy_iovec(struct xfs_log_vec *lv, struct xfs_log_iovec **vecp,
+		uint type, void *data, int len)
+{
+	void *buf;
+
+	buf = xlog_prepare_iovec(lv, vecp, type);
+	memcpy(buf, data, len);
+	xlog_finish_iovec(lv, *vecp, len);
+	return buf;
+}
+
 /*
  * Structure used to pass callback function and the function's argument
  * to the log manager.