[PATCH 5/8] libceph: define and use in_msg_pos_next()

[Alex Elder <elder@inktank.com>]

Define a new function in_msg_pos_next() to match out_msg_pos_next(),
and use it in place of code at the end of read_partial_message_pages()
and read_partial_message_bio().

Signed-off-by: Alex Elder <elder@inktank.com>
---
 net/ceph/messenger.c |   57
++++++++++++++++++++++++++++++++------------------
 1 file changed, 37 insertions(+), 20 deletions(-)

diff --git a/net/ceph/messenger.c b/net/ceph/messenger.c
index 2017b88..fb5f6e7 100644
--- a/net/ceph/messenger.c
+++ b/net/ceph/messenger.c
@@ -1052,6 +1052,28 @@ static void out_msg_pos_next(struct
ceph_connection *con, struct page *page,
 #endif
 }

+static void in_msg_pos_next(struct ceph_connection *con, size_t len,
+				size_t received)
+{
+	struct ceph_msg *msg = con->in_msg;
+
+	BUG_ON(!msg);
+	BUG_ON(!received);
+
+	con->in_msg_pos.data_pos += received;
+	con->in_msg_pos.page_pos += received;
+	if (received < len)
+		return;
+
+	BUG_ON(received != len);
+	con->in_msg_pos.page_pos = 0;
+	con->in_msg_pos.page++;
+#ifdef CONFIG_BLOCK
+	if (msg->bio)
+		iter_bio_next(&msg->bio_iter, &msg->bio_seg);
+#endif /* CONFIG_BLOCK */
+}
+
 /*
  * Write as much message data payload as we can.  If we finish, queue
  * up the footer.
@@ -1789,6 +1811,7 @@ static int read_partial_message_pages(struct
ceph_connection *con,
 				      struct page **pages,
 				      unsigned int data_len, bool do_datacrc)
 {
+	struct page *page;
 	void *p;
 	int ret;
 	int left;
@@ -1797,22 +1820,18 @@ static int read_partial_message_pages(struct
ceph_connection *con,
 		   (int)(PAGE_SIZE - con->in_msg_pos.page_pos));
 	/* (page) data */
 	BUG_ON(pages == NULL);
-	p = kmap(pages[con->in_msg_pos.page]);
-	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
-			       left);
+	page = pages[con->in_msg_pos.page];
+	p = kmap(page);
+	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos, left);
 	if (ret > 0 && do_datacrc)
 		con->in_data_crc =
 			crc32c(con->in_data_crc,
 				  p + con->in_msg_pos.page_pos, ret);
-	kunmap(pages[con->in_msg_pos.page]);
+	kunmap(page);
 	if (ret <= 0)
 		return ret;
-	con->in_msg_pos.data_pos += ret;
-	con->in_msg_pos.page_pos += ret;
-	if (con->in_msg_pos.page_pos == PAGE_SIZE) {
-		con->in_msg_pos.page_pos = 0;
-		con->in_msg_pos.page++;
-	}
+
+	in_msg_pos_next(con, left, ret);

 	return ret;
 }
@@ -1823,32 +1842,30 @@ static int read_partial_message_bio(struct
ceph_connection *con,
 {
 	struct ceph_msg *msg = con->in_msg;
 	struct bio_vec *bv;
+	struct page *page;
 	void *p;
 	int ret, left;

 	BUG_ON(!msg);
 	BUG_ON(!msg->bio_iter);
 	bv = bio_iovec_idx(msg->bio_iter, msg->bio_seg);
+
 	left = min((int)(data_len - con->in_msg_pos.data_pos),
 		   (int)(bv->bv_len - con->in_msg_pos.page_pos));

-	p = kmap(bv->bv_page) + bv->bv_offset;
+	page = bv->bv_page;
+	p = kmap(page) + bv->bv_offset;

-	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos,
-			       left);
+	ret = ceph_tcp_recvmsg(con->sock, p + con->in_msg_pos.page_pos, left);
 	if (ret > 0 && do_datacrc)
 		con->in_data_crc =
 			crc32c(con->in_data_crc,
 				  p + con->in_msg_pos.page_pos, ret);
-	kunmap(bv->bv_page);
+	kunmap(page);
 	if (ret <= 0)
 		return ret;
-	con->in_msg_pos.data_pos += ret;
-	con->in_msg_pos.page_pos += ret;
-	if (con->in_msg_pos.page_pos == bv->bv_len) {
-		con->in_msg_pos.page_pos = 0;
-		iter_bio_next(&msg->bio_iter, &msg->bio_seg);
-	}
+
+	in_msg_pos_next(con, left, ret);

 	return ret;
 }
-- 
1.7.9.5