On Thu, Nov 29, 2018 at 02:03:26PM +0000, Stefan Hajnoczi wrote:
> On Mon, Nov 05, 2018 at 05:33:22PM +0000, Stefan Hajnoczi wrote:
> > Now that there are no more data path users of vhost_vsock_lock, it can
> > be turned into a mutex. It's only used by .release() and in the
> > .ioctl() path.
> >
> > Depends-on: <20181105103547.22018-1-stefanha@xxxxxxxxxx>
> > Suggested-by: Jason Wang <jasowang@xxxxxxxxxx>
> > Signed-off-by: Stefan Hajnoczi <stefanha@xxxxxxxxxx>
> > ---
> > Hi Jason,
> > Thanks for pointing out that spin_lock_bh() is no longer necessary.
> > Let's switch to a mutex.
> > ---
> > drivers/vhost/vsock.c | 16 ++++++++--------
> > 1 file changed, 8 insertions(+), 8 deletions(-)
>
> Ping?
I'll put it on the next tree for 4.21.
Thanks!
> > diff --git a/drivers/vhost/vsock.c b/drivers/vhost/vsock.c
> > index 51879ed18652..d95b0c04cc9b 100644
> > --- a/drivers/vhost/vsock.c
> > +++ b/drivers/vhost/vsock.c
> > @@ -27,14 +27,14 @@ enum {
> > };
> >
> > /* Used to track all the vhost_vsock instances on the system. */
> > -static DEFINE_SPINLOCK(vhost_vsock_lock);
> > +static DEFINE_MUTEX(vhost_vsock_mutex);
> > static DEFINE_READ_MOSTLY_HASHTABLE(vhost_vsock_hash, 8);
> >
> > struct vhost_vsock {
> > struct vhost_dev dev;
> > struct vhost_virtqueue vqs[2];
> >
> > - /* Link to global vhost_vsock_hash, writes use vhost_vsock_lock */
> > + /* Link to global vhost_vsock_hash, writes use vhost_vsock_mutex */
> > struct hlist_node hash;
> >
> > struct vhost_work send_pkt_work;
> > @@ -51,7 +51,7 @@ static u32 vhost_transport_get_local_cid(void)
> > return VHOST_VSOCK_DEFAULT_HOST_CID;
> > }
> >
> > -/* Callers that dereference the return value must hold vhost_vsock_lock or the
> > +/* Callers that dereference the return value must hold vhost_vsock_mutex or the
> > * RCU read lock.
> > */
> > static struct vhost_vsock *vhost_vsock_get(u32 guest_cid)
> > @@ -576,10 +576,10 @@ static int vhost_vsock_dev_release(struct inode *inode, struct file *file)
> > {
> > struct vhost_vsock *vsock = file->private_data;
> >
> > - spin_lock_bh(&vhost_vsock_lock);
> > + mutex_lock(&vhost_vsock_mutex);
> > if (vsock->guest_cid)
> > hash_del_rcu(&vsock->hash);
> > - spin_unlock_bh(&vhost_vsock_lock);
> > + mutex_unlock(&vhost_vsock_mutex);
> >
> > /* Wait for other CPUs to finish using vsock */
> > synchronize_rcu();
> > @@ -623,10 +623,10 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
> > return -EINVAL;
> >
> > /* Refuse if CID is already in use */
> > - spin_lock_bh(&vhost_vsock_lock);
> > + mutex_lock(&vhost_vsock_mutex);
> > other = vhost_vsock_get(guest_cid);
> > if (other && other != vsock) {
> > - spin_unlock_bh(&vhost_vsock_lock);
> > + mutex_unlock(&vhost_vsock_mutex);
> > return -EADDRINUSE;
> > }
> >
> > @@ -635,7 +635,7 @@ static int vhost_vsock_set_cid(struct vhost_vsock *vsock, u64 guest_cid)
> >
> > vsock->guest_cid = guest_cid;
> > hash_add_rcu(vhost_vsock_hash, &vsock->hash, guest_cid);
> > - spin_unlock_bh(&vhost_vsock_lock);
> > + mutex_unlock(&vhost_vsock_mutex);
> >
> > return 0;
> > }
> > --
> > 2.19.1
> >
