Re: [Qemu-devel] [PATCH] qemu: avoid memory leak while remove disk

[wangjian]

ok, I will send the patch by git send-email.

On 12/15/2018 4:22 AM, Michael S. Tsirkin wrote:
> On Fri, Dec 07, 2018 at 09:53:06AM +0800, wangjian wrote:
> > Memset vhost_dev to zero in the vhost_dev_cleanup function.
> > This causes dev.vqs to be NULL, so that
> > vqs does not free up space when calling the g_free function.
> > This will result in a memory leak. But you can't release vqs
> > directly in the vhost_dev_cleanup function, because vhost_net
> > will also call this function, and vhost_net's vqs is assigned by array.
> > In order to solve this problem, we first save the pointer of vqs,
> > and release the space of vqs after vhost_dev_cleanup is called.
> >
> > Signed-off-by: Jian Wang <address@hidden>
> The patch does not seem to apply.
> I suspect it was corrupted by your mailer, judging by
> the fact that you also sent the patch in HTML format.
>
> Can you please fix and repost?
> Thanks!
>
>
> > ---
> >   hw/block/vhost-user-blk.c | 7 +++++--
> >   hw/scsi/vhost-scsi.c      | 3 ++-
> >   hw/scsi/vhost-user-scsi.c | 3 ++-
> >   3 files changed, 9 insertions(+), 4 deletions(-)
> >
> > diff --git a/hw/block/vhost-user-blk.c b/hw/block/vhost-user-blk.c
> > index 1451940..c3af28f 100644
> > --- a/hw/block/vhost-user-blk.c
> > +++ b/hw/block/vhost-user-blk.c
> > @@ -250,6 +250,7 @@ static void vhost_user_blk_device_realize(DeviceState *dev, 
> > Error **errp)
> >       VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >       VHostUserBlk *s = VHOST_USER_BLK(vdev);
> >       VhostUserState *user;
> > +    struct vhost_virtqueue *vqs = NULL;
> >       int i, ret;
> >
> >       if (!s->chardev.chr) {
> > @@ -288,6 +289,7 @@ static void vhost_user_blk_device_realize(DeviceState *dev, 
> > Error **errp)
> >       s->dev.vqs = g_new(struct vhost_virtqueue, s->dev.nvqs);
> >       s->dev.vq_index = 0;
> >       s->dev.backend_features = 0;
> > +    vqs = s->dev.vqs;
> >
> >       vhost_dev_set_config_notifier(&s->dev, &blk_ops);
> >
> > @@ -314,7 +316,7 @@ static void vhost_user_blk_device_realize(DeviceState *dev, 
> > Error **errp)
> >   vhost_err:
> >       vhost_dev_cleanup(&s->dev);
> >   virtio_err:
> > -    g_free(s->dev.vqs);
> > +    g_free(vqs);
> >       virtio_cleanup(vdev);
> >
> >       vhost_user_cleanup(user);
> > @@ -326,10 +328,11 @@ static void vhost_user_blk_device_unrealize(DeviceState 
> > *dev, Error **errp)
> >   {
> >       VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >       VHostUserBlk *s = VHOST_USER_BLK(dev);
> > +    struct vhost_virtqueue *vqs = s->dev.vqs;
> >
> >       vhost_user_blk_set_status(vdev, 0);
> >       vhost_dev_cleanup(&s->dev);
> > -    g_free(s->dev.vqs);
> > +    g_free(vqs);
> >       virtio_cleanup(vdev);
> >
> >       if (s->vhost_user) {
> > diff --git a/hw/scsi/vhost-scsi.c b/hw/scsi/vhost-scsi.c
> > index 7f21b4f..61e2e57 100644
> > --- a/hw/scsi/vhost-scsi.c
> > +++ b/hw/scsi/vhost-scsi.c
> > @@ -215,6 +215,7 @@ static void vhost_scsi_unrealize(DeviceState *dev, Error 
> > **errp)
> >   {
> >       VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >       VHostSCSICommon *vsc = VHOST_SCSI_COMMON(dev);
> > +    struct vhost_virtqueue *vqs = vsc->dev.vqs;
> >
> >       migrate_del_blocker(vsc->migration_blocker);
> >       error_free(vsc->migration_blocker);
> > @@ -223,7 +224,7 @@ static void vhost_scsi_unrealize(DeviceState *dev, Error 
> > **errp)
> >       vhost_scsi_set_status(vdev, 0);
> >
> >       vhost_dev_cleanup(&vsc->dev);
> > -    g_free(vsc->dev.vqs);
> > +    g_free(vqs);
> >
> >       virtio_scsi_common_unrealize(dev, errp);
> >   }
> > diff --git a/hw/scsi/vhost-user-scsi.c b/hw/scsi/vhost-user-scsi.c
> > index 2e1ba4a..6728878 100644
> > --- a/hw/scsi/vhost-user-scsi.c
> > +++ b/hw/scsi/vhost-user-scsi.c
> > @@ -121,12 +121,13 @@ static void vhost_user_scsi_unrealize(DeviceState *dev, 
> > Error **errp)
> >       VirtIODevice *vdev = VIRTIO_DEVICE(dev);
> >       VHostUserSCSI *s = VHOST_USER_SCSI(dev);
> >       VHostSCSICommon *vsc = VHOST_SCSI_COMMON(s);
> > +    struct vhost_virtqueue *vqs = vsc->dev.vqs;
> >
> >       /* This will stop the vhost backend. */
> >       vhost_user_scsi_set_status(vdev, 0);
> >
> >       vhost_dev_cleanup(&vsc->dev);
> > -    g_free(vsc->dev.vqs);
> > +    g_free(vqs);
> >
> >       virtio_scsi_common_unrealize(dev, errp);
> >
> > --
> > 1.8.3.1
> .