From: Keir Fraser <keir.fraser@citrix.com>
Date: Mon, 28 Jan 2008 10:40:58 +0000 (+0000)
Subject: [gntdev] Fix multiple-grant mapping logic
X-Git-Tag: 3.1.3-rc2~1
X-Git-Url: http://xenbits.xensource.com/gitweb?a=commitdiff_plain;h=83750da9af2f7ff8eed09712178656aa89d20d0d;p=people%2Fvhanquez%2Fxen.git

[gntdev] Fix multiple-grant mapping logic
Signed-off-by: Derek Murray <Derek.Murray@cl.cam.ac.uk>
linux-2.6.18-xen changeset:   399:6157dbf408cf9c50a658eb9fdacfc78ca72bd06a
linux-2.6.18-xen date:        Mon Jan 28 10:29:58 2008 +0000
---

diff --git a/linux-2.6-xen-sparse/drivers/xen/gntdev/gntdev.c b/linux-2.6-xen-sparse/drivers/xen/gntdev/gntdev.c
index dab7ccbff..7538c2324 100644
--- a/linux-2.6-xen-sparse/drivers/xen/gntdev/gntdev.c
+++ b/linux-2.6-xen-sparse/drivers/xen/gntdev/gntdev.c
@@ -215,6 +215,8 @@ static int add_grant_reference(struct file *flip,
 	}
 
 	slot_index = private_data->free_list[--private_data->free_list_size];
+	private_data->free_list[private_data->free_list_size]
+		= GNTDEV_FREE_LIST_INVALID;
 
 	/* Copy the grant information into file's private data. */
 	private_data->grants[slot_index].state = GNTDEV_SLOT_NOT_YET_MAPPED;
@@ -271,13 +273,19 @@ static void compress_free_list(struct file *flip)
 {
 	gntdev_file_private_data_t *private_data 
 		= (gntdev_file_private_data_t *) flip->private_data;
-	int i, j = 0, old_size;
+	int i, j = 0, old_size, slot_index;
 	
 	old_size = private_data->free_list_size;
 	for (i = 0; i < old_size; ++i) {
 		if (private_data->free_list[i] != GNTDEV_FREE_LIST_INVALID) {
-			private_data->free_list[j] = 
-				private_data->free_list[i];
+			if (i > j) {
+				slot_index = private_data->free_list[i];
+				private_data->free_list[j] = slot_index;
+				private_data->grants[slot_index].u
+					.free_list_index = j;
+				private_data->free_list[i] 
+					= GNTDEV_FREE_LIST_INVALID;
+			}
 			++j;
 		} else {
 			--private_data->free_list_size;
@@ -908,7 +916,6 @@ static long gntdev_ioctl(struct file *flip,
 				start_index + i;
 			++private_data->free_list_size;
 		}
-		compress_free_list(flip);
 
 	unmap_out:
 		up_write(&private_data->grants_sem);