xfs: introduce xlog_copy_iovec

Add a helper to abstract out filling the log iovecs in the log item
format handlers.  This will allow us to change the way we do the log
item formatting more easily.

The copy in the name is a bit confusing for now as it just assigns a
pointer and lets the CIL code perform the copy, but that will change
soon.

Signed-off-by: Christoph Hellwig <hch@lst.de>
Reviewed-by: Dave Chinner <dchinner@redhat.com>
Signed-off-by: Dave Chinner <david@fromorbit.com>

1 files changed, 13 insertions, 0 deletions

diff --git a/fs/xfs/xfs_log.h b/fs/xfs/xfs_log.h
index e148719..384c6c4 100644
--- a/fs/xfs/xfs_log.h
+++ b/fs/xfs/xfs_log.h
@@ -30,6 +30,19 @@ 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)
+{
+	struct xfs_log_iovec *vec = *vecp;
+
+	vec->i_type = type;
+	vec->i_addr = data;
+	vec->i_len = len;
+
+	*vecp = vec + 1;
+	return vec->i_addr;
+}
+
 /*
  * Structure used to pass callback function and the function's argument
  * to the log manager.