util: add spdk_iovmove()

It's the same as spdk_iovcpy(), but the dst/src buffers can overlap.

Signed-off-by: Konrad Sztyber <konrad.sztyber@intel.com>
Change-Id: I6daa0a846d7d1deac2c01d1a1be09171fa8bf796
Reviewed-on: https://review.spdk.io/gerrit/c/spdk/spdk/+/15747
Tested-by: SPDK CI Jenkins <sys_sgci@intel.com>
Reviewed-by: Ben Walker <benjamin.walker@intel.com>
Reviewed-by: Jim Harris <james.r.harris@intel.com>
Reviewed-by: Aleksey Marchuk <alexeymar@nvidia.com>

include/spdk/util.h

@@ -108,6 +108,13 @@ spdk_divide_round_up(uint64_t num, uint64_t divisor)
  */
 size_t spdk_iovcpy(struct iovec *siov, size_t siovcnt, struct iovec *diov, size_t diovcnt);
 
+/**
+ * Same as spdk_iovcpy(), but the src/dst buffers might overlap.
+ *
+ * \return The number of bytes copied.
+ */
+size_t spdk_iovmove(struct iovec *siov, size_t siovcnt, struct iovec *diov, size_t diovcnt);
+
 /**
  * An iovec iterator. Can be allocated on the stack.
  */

lib/util/iov.c

@@ -104,6 +104,24 @@ spdk_iovcpy(struct iovec *siov, size_t siovcnt, struct iovec *diov, size_t diovc
 	return total_sz;
 }
 
+size_t
+spdk_iovmove(struct iovec *siov, size_t siovcnt, struct iovec *diov, size_t diovcnt)
+{
+	struct spdk_ioviter iter;
+	size_t len, total_sz;
+	void *src, *dst;
+
+	total_sz = 0;
+	for (len = spdk_ioviter_first(&iter, siov, siovcnt, diov, diovcnt, &src, &dst);
+	     len != 0;
+	     len = spdk_ioviter_next(&iter, &src, &dst)) {
+		memmove(dst, src, len);
+		total_sz += len;
+	}
+
+	return total_sz;
+}
+
 void
 spdk_copy_iovs_to_buf(void *buf, size_t buf_len, struct iovec *iovs, int iovcnt)
 {

lib/util/spdk_util.map

@@ -131,6 +131,7 @@
 	spdk_u32log2;
 	spdk_u64log2;
 	spdk_iovcpy;
+	spdk_iovmove;
 	spdk_ioviter_first;
 	spdk_ioviter_next;
 	spdk_copy_iovs_to_buf;