Commit 1401c00e authored by David Vrabel's avatar David Vrabel
Browse files

xen/gntdev: convert priv->lock to a mutex 



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

Signed-off-by: default avatarDavid Vrabel <david.vrabel@citrix.com>
Reviewed-by: default avatarStefano Stabellini <stefano.stabellini@eu.citrix.com>
parent 3f9f1c67

drivers/xen/gntdev.c

+20 −20
Original line number Diff line number Diff line
@@ -67,7 +67,7 @@ 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;

};
@@ -221,9 +221,9 @@ static void gntdev_put_map(struct gntdev_priv *priv, struct grant_map *map) 
	}



	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)
@@ -395,9 +395,9 @@ static void gntdev_vma_close(struct vm_area_struct *vma) 
		 * 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);
@@ -441,14 +441,14 @@ static void mn_invl_range_start(struct mmu_notifier *mn, 
	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,
@@ -465,7 +465,7 @@ static void mn_release(struct mmu_notifier *mn, 
	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;
@@ -484,7 +484,7 @@ static void mn_release(struct mmu_notifier *mn, 
		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 = {
@@ -506,7 +506,7 @@ static int gntdev_open(struct inode *inode, struct file *flip) 


	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);
@@ -580,10 +580,10 @@ static long gntdev_ioctl_map_grant_ref(struct gntdev_priv *priv, 
		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;
@@ -602,7 +602,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, 
		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);
@@ -610,7 +610,7 @@ static long gntdev_ioctl_unmap_grant_ref(struct gntdev_priv *priv, 
			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;
@@ -678,7 +678,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) 
	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;
@@ -706,7 +706,7 @@ static long gntdev_ioctl_notify(struct gntdev_priv *priv, void __user *u) 
	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)
@@ -756,7 +756,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) 
	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;
@@ -791,7 +791,7 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) 
			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,
@@ -819,11 +819,11 @@ static int gntdev_mmap(struct file *flip, struct vm_area_struct *vma) 
	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;