[v2,11/14] vfio/mbochs: Fix close when multiple device FDs are open

Commit Message

Jason Gunthorpe July 20, 2021, 5:42 p.m. UTC

mbochs_close() iterates over global device state and frees it. Currently
this is done every time a device FD is closed, but if multiple device FDs
are open this could corrupt other still active FDs.

Change this to use close_device() so it only runs on the last close.

Reviewed-by: Cornelia Huck <[e-mail]>
Signed-off-by: Jason Gunthorpe <[e-mail]>
---
 samples/vfio-mdev/mbochs.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

Comments

Christoph Hellwig July 23, 2021, 8:13 a.m. UTC | #1

On Tue, Jul 20, 2021 at 02:42:57PM -0300, Jason Gunthorpe wrote:
> mbochs_close() iterates over global device state and frees it. Currently
> this is done every time a device FD is closed, but if multiple device FDs
> are open this could corrupt other still active FDs.
> 
> Change this to use close_device() so it only runs on the last close.
> 
> Reviewed-by: Cornelia Huck <[e-mail]>
> Signed-off-by: Jason Gunthorpe <[e-mail]>

Looks good,

Reviewed-by: Christoph Hellwig <[e-mail]>

Patch

diff --git a/samples/vfio-mdev/mbochs.c b/samples/vfio-mdev/mbochs.c
index fb81d11029e8a5..39002b07e692ac 100644
--- a/samples/vfio-mdev/mbochs.c
+++ b/samples/vfio-mdev/mbochs.c
@@ -1277,7 +1277,7 @@  static long mbochs_ioctl(struct vfio_device *vdev, unsigned int cmd,
 	return -ENOTTY;
 }
 
-static void mbochs_close(struct vfio_device *vdev)
+static void mbochs_close_device(struct vfio_device *vdev)
 {
 	struct mdev_state *mdev_state =
 		container_of(vdev, struct mdev_state, vdev);
@@ -1395,7 +1395,7 @@  static struct attribute_group *mdev_type_groups[] = {
 };
 
 static const struct vfio_device_ops mbochs_dev_ops = {
-	.release = mbochs_close,
+	.close_device = mbochs_close_device,
 	.read = mbochs_read,
 	.write = mbochs_write,
 	.ioctl = mbochs_ioctl,