[Scst-svn] [master] iscsi-scst: Port to Linux kernel v6.5

[Gleb C. <lna...@ya...>]

Commit: 16a17c2
GitHub URL: https://github.com/SCST-project/scst/commit/16a17c259bc6c349871c6c60fe5e254301efd72e
Author: Gleb Chesnokov
Date: 2023-07-10T10:34:57+03:00
Log Message:
-----------
iscsi-scst: Port to Linux kernel v6.5

Use sendmsg() conditionally with MSG_SPLICE_PAGES in write_data()
rather than calling sendpage().

Support for the following net layer changes in the Linux kernel v6.5:

- dc97391e6610 ("sock: Remove ->sendpage*() in favour of
  sendmsg(MSG_SPLICE_PAGES)")

Modified Paths:
--------------
 iscsi-scst/kernel/conn.c    |  9 +++--
 iscsi-scst/kernel/nthread.c | 26 ++++++++++++---
 2 files changed, 25 insertions(+), 10 deletions(-)

===================================================================
diff --git a/iscsi-scst/kernel/conn.c b/iscsi-scst/kernel/conn.c
index 031e6c3..487cf65 100644
--- a/iscsi-scst/kernel/conn.c
+++ b/iscsi-scst/kernel/conn.c
@@ -741,7 +741,6 @@ int conn_activate(struct iscsi_conn *conn)
 
 static int conn_setup_sock(struct iscsi_conn *conn)
 {
-	int res = 0;
 	int opt = 1;
 	mm_segment_t oldfs;
 	struct iscsi_session *session = conn->session;
@@ -750,12 +749,13 @@ static int conn_setup_sock(struct iscsi_conn *conn)
 
 	conn->sock = SOCKET_I(file_inode(conn->file));
 
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 5, 0)
 	if (conn->sock->ops->sendpage == NULL) {
 		PRINT_ERROR("Socket for sid %llx doesn't support sendpage()",
 			    (unsigned long long)session->sid);
-		res = -EINVAL;
-		goto out;
+		return -EINVAL;
 	}
+#endif
 
 #if 0
 	conn->sock->sk->sk_allocation = GFP_NOIO;
@@ -768,8 +768,7 @@ static int conn_setup_sock(struct iscsi_conn *conn)
 				    KERNEL_SOCKPTR(&opt), sizeof(opt));
 	set_fs(oldfs);
 
-out:
-	return res;
+	return 0;
 }
 
 void iscsi_tcp_conn_free(struct iscsi_conn *conn)
diff --git a/iscsi-scst/kernel/nthread.c b/iscsi-scst/kernel/nthread.c
index d335340..09a2330 100644
--- a/iscsi-scst/kernel/nthread.c
+++ b/iscsi-scst/kernel/nthread.c
@@ -1096,8 +1096,13 @@ out:
 static int write_data(struct iscsi_conn *conn)
 {
 	struct socket *sock;
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 5, 0)
 	ssize_t (*sock_sendpage)(struct socket *sock, struct page *page,
 				 int offset, size_t size, int flags);
+#else
+	struct msghdr msg = {};
+	struct bio_vec bvec;
+#endif
 	struct iscsi_cmnd *write_cmnd, *parent_req;
 	struct iscsi_cmnd *ref_cmd;
 	struct page *page;
@@ -1190,9 +1195,13 @@ static int write_data(struct iscsi_conn *conn)
 	if (sg != write_cmnd->rsp_sg &&
 	    (!parent_req->scst_cmd || parent_req->scst_state == ISCSI_CMD_STATE_AEN ||
 	     !scst_cmd_get_dh_data_buff_alloced(parent_req->scst_cmd)))
+#if LINUX_VERSION_CODE >= KERNEL_VERSION(6, 5, 0)
+		flags |= MSG_SPLICE_PAGES;
+#else
 		sock_sendpage = sock->ops->sendpage;
 	else
 		sock_sendpage = sock_no_sendpage;
+#endif
 
 	sg_size = size;
 
@@ -1236,14 +1245,21 @@ static int write_data(struct iscsi_conn *conn)
 			flags |= MSG_MORE;
 
 		while (sendsize) {
+#if LINUX_VERSION_CODE < KERNEL_VERSION(6, 5, 0)
 			res = sock_sendpage(sock, page, offset, sendsize, flags);
+#else
+			memset(&msg, 0, sizeof(struct msghdr));
+			msg.msg_flags = flags;
+
+			bvec_set_page(&bvec, page, sendsize, offset);
+			iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bvec, 1, sendsize);
+			res = sock_sendmsg(sock, &msg);
+#endif
 			TRACE_WRITE(
-	"%s sid %#Lx, cid %u, res %d (page index %lu, offset %u, sendsize %lu, size %lu, cmd %p, page %p)",
-				    (sock_sendpage != sock_no_sendpage) ?
-				    "sendpage" : "sock_no_sendpage",
+	"sid %#Lx cid %u: res %d (page[%p] index %lu, offset %u, sendsize %lu, size %lu, cmd %p)",
 				    (unsigned long long)conn->session->sid, conn->cid,
-				    res, page->index, offset, sendsize, size,
-				    write_cmnd, page);
+				    res, page, page->index, offset, sendsize, size,
+				    write_cmnd);
 
 			if (unlikely(res <= 0)) {
 				if (res == -EINTR)