On 2018/11/6 上午1:33, 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(-)
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;
}
Acked-by: Jason Wang <jasowang@xxxxxxxxxx>
