writeback: add wbc_to_write_flags()

Add wbc_to_write_flags(), which returns the write modifier flags to use,
based on a struct writeback_control. No functional changes in this
patch, but it prepares us for factoring other wbc fields for write type.

Signed-off-by: Jens Axboe <axboe@fb.com>
Reviewed-by: Jan Kara <jack@suse.cz>
Reviewed-by: Christoph Hellwig <hch@lst.de>

1 files changed, 9 insertions, 0 deletions

diff --git a/include/linux/writeback.h b/include/linux/writeback.h
index e4c38703bf4e..50c96ee8108f 100644
--- a/include/linux/writeback.h
+++ b/include/linux/writeback.h
@@ -9,6 +9,7 @@
 #include <linux/fs.h>
 #include <linux/flex_proportions.h>
 #include <linux/backing-dev-defs.h>
+#include <linux/blk_types.h>
 
 struct bio;
 
@@ -102,6 +103,14 @@ struct writeback_control {
 #endif
 };
 
+static inline int wbc_to_write_flags(struct writeback_control *wbc)
+{
+	if (wbc->sync_mode == WB_SYNC_ALL)
+		return REQ_SYNC;
+
+	return 0;
+}
+
 /*
  * A wb_domain represents a domain that wb's (bdi_writeback's) belong to
  * and are measured against each other in.  There always is one global