[PATCH 1/2] scatterlist: add sg_nents

[Maxim Levitsky <maximlevitsky@gmail.com>]

Useful helper to know the number of entries in scatterlist.

Signed-off-by: Maxim Levitsky <maximlevitsky@gmail.com>
---
 include/linux/scatterlist.h |    1 +
 lib/scatterlist.c           |   22 ++++++++++++++++++++++
 2 files changed, 23 insertions(+)

diff --git a/include/linux/scatterlist.h b/include/linux/scatterlist.h
index 7b600da..4bd6c06 100644
--- a/include/linux/scatterlist.h
+++ b/include/linux/scatterlist.h
@@ -201,6 +201,7 @@ static inline void *sg_virt(struct scatterlist *sg)
 	return page_address(sg_page(sg)) + sg->offset;
 }
 
+int sg_nents(struct scatterlist *sg);
 struct scatterlist *sg_next(struct scatterlist *);
 struct scatterlist *sg_last(struct scatterlist *s, unsigned int);
 void sg_init_table(struct scatterlist *, unsigned int);
diff --git a/lib/scatterlist.c b/lib/scatterlist.c
index e76d85c..5cd9cdc 100644
--- a/lib/scatterlist.c
+++ b/lib/scatterlist.c
@@ -39,6 +39,28 @@ struct scatterlist *sg_next(struct scatterlist *sg)
 EXPORT_SYMBOL(sg_next);
 
 /**
+ * sg_nents - return total count of entries in scatterlist
+ * @sg:		The scatterlist
+ *
+ * Description:
+ * Allows to know how many entries are in sg, taking into acount
+ * chaining as well
+ *
+ **/
+int sg_nents(struct scatterlist *sg)
+{
+	int nents = 0;
+	while (sg) {
+		nents++;
+		sg = sg_next(sg);
+	}
+
+	return nents;
+}
+EXPORT_SYMBOL(sg_nents);
+
+
+/**
  * sg_last - return the last scatterlist entry in a list
  * @sgl:	First entry in the scatterlist
  * @nents:	Number of entries in the scatterlist
-- 
1.7.9.5