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?
> 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
>
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