[PATCH 3.10 23/56] xen/gntdev: convert priv->lock to a mutex

[Greg Kroah-Hartman <gregkh@linuxfoundation.org>]

3.10-stable review patch.  If anyone has any objections, please let me know.

------------------

From: David Vrabel <david.vrabel@citrix.com>

commit 1401c00e59ea021c575f74612fe2dbba36d6a4ee upstream.

Unmapping may require sleeping and we unmap while holding priv->lock, so
convert it to a mutex.

Signed-off-by: David Vrabel <david.vrabel@citrix.com>
Reviewed-by: Stefano Stabellini <stefano.stabellini@eu.citrix.com>
Cc: Ian Campbell <ian.campbell@citrix.com>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

---
 drivers/xen/gntdev.c |   40 ++++++++++++++++++++--------------------
 1 file changed, 20 insertions(+), 20 deletions(-)

--- a/drivers/xen/gntdev.c
+++ b/drivers/xen/gntdev.c
@@ -65,7 +65,7 @@ struct gntdev_priv {
 	 * Only populated if populate_freeable_maps == 1 */
 	struct list_head freeable_maps;
 	/* lock protects maps and freeable_maps */
-	spinlock_t lock;
+	struct mutex lock;
 	struct mm_struct *mm;
 	struct mmu_notifier mn;
 };
@@ -214,9 +214,9 @@ static void gntdev_put_map(struct gntdev
 	}
 
 	if (populate_freeable_maps && priv) {
-		spin_lock(&priv->lock);
+		mutex_lock(&priv->lock);
 		list_del(&map->next);
-		spin_unlock(&priv->lock);
+		mutex_unlock(&priv->lock);
 	}
 
 	if (map->pages && !use_ptemod)
@@ -392,9 +392,9 @@ static void gntdev_vma_close(struct vm_a
 		 * not do any unmapping, since that has been done prior to
 		 * closing the vma, but it may still iterate the unmap_ops list.
 		 */
-		spin_lock(&priv->lock);
+		mutex_lock(&priv->lock);
 		map->vma = NULL;
-		spin_unlock(&priv->lock);
+		mutex_unlock(&priv->lock);
 	}
 	vma->vm_private_data = NULL;
 	gntdev_put_map(priv, map);
@@ -438,14 +438,14 @@ static void mn_invl_range_start(struct m
 	struct gntdev_priv *priv = container_of(mn, struct gntdev_priv, mn);
 	struct grant_map *map;
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 	list_for_each_entry(map, &priv->maps, next) {
 		unmap_if_in_range(map, start, end);
 	}
 	list_for_each_entry(map, &priv->freeable_maps, next) {
 		unmap_if_in_range(map, start, end);
 	}
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 }
 
 static void mn_invl_page(struct mmu_notifier *mn,
@@ -462,7 +462,7 @@ static void mn_release(struct mmu_notifi
 	struct grant_map *map;
 	int err;
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 	list_for_each_entry(map, &priv->maps, next) {
 		if (!map->vma)
 			continue;
@@ -481,7 +481,7 @@ static void mn_release(struct mmu_notifi
 		err = unmap_grant_pages(map, /* offset */ 0, map->count);
 		WARN_ON(err);
 	}
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 }
 
 static struct mmu_notifier_ops gntdev_mmu_ops = {
@@ -503,7 +503,7 @@ static int gntdev_open(struct inode *ino
 
 	INIT_LIST_HEAD(&priv->maps);
 	INIT_LIST_HEAD(&priv->freeable_maps);
-	spin_lock_init(&priv->lock);
+	mutex_init(&priv->lock);
 
 	if (use_ptemod) {
 		priv->mm = get_task_mm(current);
@@ -579,10 +579,10 @@ static long gntdev_ioctl_map_grant_ref(s
 		return -EFAULT;
 	}
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 	gntdev_add_map(priv, map);
 	op.index = map->index << PAGE_SHIFT;
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 
 	if (copy_to_user(u, &op, sizeof(op)) != 0)
 		return -EFAULT;
@@ -601,7 +601,7 @@ static long gntdev_ioctl_unmap_grant_ref
 		return -EFAULT;
 	pr_debug("priv %p, del %d+%d\n", priv, (int)op.index, (int)op.count);
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 	map = gntdev_find_map_index(priv, op.index >> PAGE_SHIFT, op.count);
 	if (map) {
 		list_del(&map->next);
@@ -609,7 +609,7 @@ static long gntdev_ioctl_unmap_grant_ref
 			list_add_tail(&map->next, &priv->freeable_maps);
 		err = 0;
 	}
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 	if (map)
 		gntdev_put_map(priv, map);
 	return err;
@@ -677,7 +677,7 @@ static long gntdev_ioctl_notify(struct g
 	out_flags = op.action;
 	out_event = op.event_channel_port;
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 
 	list_for_each_entry(map, &priv->maps, next) {
 		uint64_t begin = map->index << PAGE_SHIFT;
@@ -705,7 +705,7 @@ static long gntdev_ioctl_notify(struct g
 	rc = 0;
 
  unlock_out:
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 
 	/* Drop the reference to the event channel we did not save in the map */
 	if (out_flags & UNMAP_NOTIFY_SEND_EVENT)
@@ -755,7 +755,7 @@ static int gntdev_mmap(struct file *flip
 	pr_debug("map %d+%d at %lx (pgoff %lx)\n",
 			index, count, vma->vm_start, vma->vm_pgoff);
 
-	spin_lock(&priv->lock);
+	mutex_lock(&priv->lock);
 	map = gntdev_find_map_index(priv, index, count);
 	if (!map)
 		goto unlock_out;
@@ -790,7 +790,7 @@ static int gntdev_mmap(struct file *flip
 			map->flags |= GNTMAP_readonly;
 	}
 
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 
 	if (use_ptemod) {
 		err = apply_to_page_range(vma->vm_mm, vma->vm_start,
@@ -818,11 +818,11 @@ static int gntdev_mmap(struct file *flip
 	return 0;
 
 unlock_out:
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 	return err;
 
 out_unlock_put:
-	spin_unlock(&priv->lock);
+	mutex_unlock(&priv->lock);
 out_put_map:
 	if (use_ptemod)
 		map->vma = NULL;