From 2aa3560294ae0d86236064afee8515c2fe5ae2e4 Mon Sep 17 00:00:00 2001
From: Herbert Xu <herbert@gondor.apana.org.au>
Date: Wed, 29 Aug 2007 16:31:34 +0800
Subject: [PATCH] --- yaml --- r: 67023 b: refs/heads/master c:
 5fa0fea27461f5ff7fad07687618db08272e9502 h: refs/heads/master i:   67021:
 010f6cd444a7c5f74199a8af255a4df5bb164d4f   67019:
 6a133b5c86310a4d9b493840fbacbdbcc88422d5   67015:
 3db42c6f1ba91d45e416303b671d23a4537c57b3   67007:
 69f88417c94ec7c849f02d266bf3b5aa3bd2f145 v: v3

---
 [refs]                     |  2 +-
 trunk/crypto/scatterwalk.c | 22 ++++++++++++++++++++++
 trunk/crypto/scatterwalk.h |  3 +++
 3 files changed, 26 insertions(+), 1 deletion(-)

diff --git a/[refs] b/[refs]
index 8ec94fd5f9cb..74a20e6a839a 100644
--- a/[refs]
+++ b/[refs]
@@ -1,2 +1,2 @@
 ---
-refs/heads/master: e962a653f3146330d99aefa5adadeaed60bc9bb5
+refs/heads/master: 5fa0fea27461f5ff7fad07687618db08272e9502
diff --git a/trunk/crypto/scatterwalk.c b/trunk/crypto/scatterwalk.c
index 81afd1790a1d..e93a8f6f35d4 100644
--- a/trunk/crypto/scatterwalk.c
+++ b/trunk/crypto/scatterwalk.c
@@ -107,3 +107,25 @@ void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
 	}
 }
 EXPORT_SYMBOL_GPL(scatterwalk_copychunks);
+
+void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
+			      unsigned int start, unsigned int nbytes, int out)
+{
+	struct scatter_walk walk;
+	unsigned int offset = 0;
+
+	for (;;) {
+		scatterwalk_start(&walk, sg);
+
+		if (start < offset + sg->length)
+			break;
+
+		offset += sg->length;
+		sg = sg_next(sg);
+	}
+
+	scatterwalk_advance(&walk, start - offset);
+	scatterwalk_copychunks(buf, &walk, nbytes, out);
+	scatterwalk_done(&walk, out, 0);
+}
+EXPORT_SYMBOL_GPL(scatterwalk_map_and_copy);
diff --git a/trunk/crypto/scatterwalk.h b/trunk/crypto/scatterwalk.h
index f1592cc2d0f4..500a220ad908 100644
--- a/trunk/crypto/scatterwalk.h
+++ b/trunk/crypto/scatterwalk.h
@@ -74,4 +74,7 @@ void scatterwalk_copychunks(void *buf, struct scatter_walk *walk,
 void *scatterwalk_map(struct scatter_walk *walk, int out);
 void scatterwalk_done(struct scatter_walk *walk, int out, int more);
 
+void scatterwalk_map_and_copy(void *buf, struct scatterlist *sg,
+			      unsigned int start, unsigned int nbytes, int out);
+
 #endif  /* _CRYPTO_SCATTERWALK_H */