[openib-general] [PATCH] support kernel-level sockets in sdp

[Michael S. Tsirkin]

Hi!
I plan to commit the following. Comments?

---

The following patch adds support for kernel-level sockets in SDP Zcopy
(currently used with AIO).

Signed-off-by: Michael S. Tsirkin <mst at mellanox.co.il>

Index: drivers/infiniband/ulp/sdp/sdp_iocb.c
===================================================================
--- drivers/infiniband/ulp/sdp/sdp_iocb.c	(revision 3958)
+++ drivers/infiniband/ulp/sdp/sdp_iocb.c	(working copy)
@@ -176,30 +176,40 @@
 	if (!iocb->page_array)
 		goto err_page;
  
-	down_read(&current->mm->mmap_sem);
- 
-        result = get_user_pages(current, current->mm,
-				iocb->addr, iocb->page_count,
-			      !!(iocb->flags & SDP_IOCB_F_RECV), 0,
-			      iocb->page_array, NULL);
+	if (segment_eq(get_fs(), get_ds())) {
+		/* Kernel request */
+		for (i = 0; i< iocb->page_count; ++i) {
+			iocb->page_array[i] = virt_to_page(addr);
+			iocb->addr_array[i] = page_to_phys(iocb->page_array[i]);
+			addr += PAGE_SIZE;
+		}
+	} else {
+		/* User-level request */
+		down_read(&current->mm->mmap_sem);
 
-	up_read(&current->mm->mmap_sem);
+		result = get_user_pages(current, current->mm,
+					iocb->addr, iocb->page_count,
+					!!(iocb->flags & SDP_IOCB_F_RECV), 0,
+					iocb->page_array, NULL);
 
-	if (result != iocb->page_count) {
-		sdp_dbg_err("unable to lock <%lx:%Zu> error <%d> <%d>",
-			    iocb->addr, iocb->size, result, iocb->page_count);
-		goto err_get;
+		up_read(&current->mm->mmap_sem);
+
+		if (result != iocb->page_count) {
+			sdp_dbg_err("unable to lock <%lx:%Zu> error <%d> <%d>",
+				    iocb->addr, iocb->size, result,
+				    iocb->page_count);
+			goto err_get;
+		}
+
+		iocb->flags |= SDP_IOCB_F_LOCKED;
+		iocb->mm     = current->mm;
+		iocb->tsk    = current;
+
+
+		for (i = 0; i< iocb->page_count; ++i) {
+			iocb->addr_array[i] = page_to_phys(iocb->page_array[i]);
+		}
 	}
- 
-	iocb->flags |= SDP_IOCB_F_LOCKED;
-	iocb->mm     = current->mm;
-	iocb->tsk    = current;
- 
- 
-	for (i = 0; i< iocb->page_count; ++i) {
-		iocb->addr_array[i] = page_to_phys(iocb->page_array[i]);
- 	}
- 
  	return 0;
  
 err_get:

-- 
MST