scsi: iscsi_tcp: Use sendmsg(MSG_SPLICE_PAGES) rather than sendpage

Use sendmsg() with MSG_SPLICE_PAGES rather than sendpage.  This allows
multiple pages and multipage folios to be passed through.

Signed-off-by: David Howells <dhowells@redhat.com>
Reviewed-by: Mike Christie <michael.christie@oracle.com>
cc: Lee Duncan <lduncan@suse.com>
cc: Chris Leech <cleech@redhat.com>
cc: "James E.J. Bottomley" <jejb@linux.ibm.com>
cc: "Martin K. Petersen" <martin.petersen@oracle.com>
cc: Jens Axboe <axboe@kernel.dk>
cc: Matthew Wilcox <willy@infradead.org>
cc: Al Viro <viro@zeniv.linux.org.uk>
cc: open-iscsi@googlegroups.com
Link: https://lore.kernel.org/r/20230623225513.2732256-12-dhowells@redhat.com
Signed-off-by: Jakub Kicinski <kuba@kernel.org>

diff --git a/drivers/scsi/iscsi_tcp.c b/drivers/scsi/iscsi_tcp.c
index 9637d4b..9ab8555 100644 (file)
--- a/drivers/scsi/iscsi_tcp.c
+++ b/drivers/scsi/iscsi_tcp.c
@@ -301,35 +301,32 @@ static int iscsi_sw_tcp_xmit_segment(struct iscsi_tcp_conn *tcp_conn,
 
        while (!iscsi_tcp_segment_done(tcp_conn, segment, 0, r)) {
                struct scatterlist *sg;
+               struct msghdr msg = {};
+               struct bio_vec bv;
                unsigned int offset, copy;
-               int flags = 0;
 
                r = 0;
                offset = segment->copied;
                copy = segment->size - offset;
 
                if (segment->total_copied + segment->size < segment->total_size)
-                       flags |= MSG_MORE | MSG_SENDPAGE_NOTLAST;
+                       msg.msg_flags |= MSG_MORE;
 
                if (tcp_sw_conn->queue_recv)
-                       flags |= MSG_DONTWAIT;
+                       msg.msg_flags |= MSG_DONTWAIT;
 
-               /* Use sendpage if we can; else fall back to sendmsg */
                if (!segment->data) {
+                       if (!tcp_conn->iscsi_conn->datadgst_en)
+                               msg.msg_flags |= MSG_SPLICE_PAGES;
                        sg = segment->sg;
                        offset += segment->sg_offset + sg->offset;
-                       r = tcp_sw_conn->sendpage(sk, sg_page(sg), offset,
-                                                 copy, flags);
+                       bvec_set_page(&bv, sg_page(sg), copy, offset);
                } else {
-                       struct msghdr msg = { .msg_flags = flags };
-                       struct kvec iov = {
-                               .iov_base = segment->data + offset,
-                               .iov_len = copy
-                       };
-
-                       r = kernel_sendmsg(sk, &msg, &iov, 1, copy);
+                       bvec_set_virt(&bv, segment->data + offset, copy);
                }
+               iov_iter_bvec(&msg.msg_iter, ITER_SOURCE, &bv, 1, copy);
 
+               r = sock_sendmsg(sk, &msg);
                if (r < 0) {
                        iscsi_tcp_segment_unmap(segment);
                        return r;
@@ -746,7 +743,6 @@ iscsi_sw_tcp_conn_bind(struct iscsi_cls_session *cls_session,
        sock_no_linger(sk);
 
        iscsi_sw_tcp_conn_set_callbacks(conn);
-       tcp_sw_conn->sendpage = tcp_sw_conn->sock->ops->sendpage;
        /*
         * set receive state machine into initial state
         */
@@ -777,8 +773,6 @@ static int iscsi_sw_tcp_conn_set_param(struct iscsi_cls_conn *cls_conn,
                        return -ENOTCONN;
                }
                iscsi_set_param(cls_conn, param, buf, buflen);
-               tcp_sw_conn->sendpage = conn->datadgst_en ?
-                       sock_no_sendpage : tcp_sw_conn->sock->ops->sendpage;
                mutex_unlock(&tcp_sw_conn->sock_lock);
                break;
        case ISCSI_PARAM_MAX_R2T:

diff --git a/drivers/scsi/iscsi_tcp.h b/drivers/scsi/iscsi_tcp.h
index 68e14a3..89a6fc5 100644 (file)
--- a/drivers/scsi/iscsi_tcp.h
+++ b/drivers/scsi/iscsi_tcp.h
@@ -47,8 +47,6 @@ struct iscsi_sw_tcp_conn {
        /* MIB custom statistics */
        uint32_t                sendpage_failures_cnt;
        uint32_t                discontiguous_hdr_cnt;
-
-       ssize_t (*sendpage)(struct socket *, struct page *, int, size_t, int);
 };
 
 struct iscsi_sw_tcp_host {