diff options
| -rw-r--r-- | drivers/vhost/net.c | 37 | ||||
| -rw-r--r-- | drivers/vhost/scsi.c | 17 | ||||
| -rw-r--r-- | drivers/vhost/test.c | 6 | ||||
| -rw-r--r-- | drivers/vhost/vhost.h | 10 |
4 files changed, 26 insertions, 44 deletions
diff --git a/drivers/vhost/net.c b/drivers/vhost/net.c index 027be91db139..969a85960e9f 100644 --- a/drivers/vhost/net.c +++ b/drivers/vhost/net.c @@ -15,7 +15,6 @@ #include <linux/moduleparam.h> #include <linux/mutex.h> #include <linux/workqueue.h> -#include <linux/rcupdate.h> #include <linux/file.h> #include <linux/slab.h> @@ -346,12 +345,11 @@ static void handle_tx(struct vhost_net *net) struct vhost_net_ubuf_ref *uninitialized_var(ubufs); bool zcopy, zcopy_used; - /* TODO: check that we are running from vhost_worker? */ - sock = rcu_dereference_check(vq->private_data, 1); + mutex_lock(&vq->mutex); + sock = vq->private_data; if (!sock) - return; + goto out; - mutex_lock(&vq->mutex); vhost_disable_notify(&net->dev, vq); hdr_size = nvq->vhost_hlen; @@ -461,7 +459,7 @@ static void handle_tx(struct vhost_net *net) break; } } - +out: mutex_unlock(&vq->mutex); } @@ -570,14 +568,14 @@ static void handle_rx(struct vhost_net *net) s16 headcount; size_t vhost_hlen, sock_hlen; size_t vhost_len, sock_len; - /* TODO: check that we are running from vhost_worker? */ - struct socket *sock = rcu_dereference_check(vq->private_data, 1); - - if (!sock) - return; + struct socket *sock; mutex_lock(&vq->mutex); + sock = vq->private_data; + if (!sock) + goto out; vhost_disable_notify(&net->dev, vq); + vhost_hlen = nvq->vhost_hlen; sock_hlen = nvq->sock_hlen; @@ -652,7 +650,7 @@ static void handle_rx(struct vhost_net *net) break; } } - +out: mutex_unlock(&vq->mutex); } @@ -750,8 +748,7 @@ static int vhost_net_enable_vq(struct vhost_net *n, struct vhost_poll *poll = n->poll + (nvq - n->vqs); struct socket *sock; - sock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + sock = vq->private_data; if (!sock) return 0; @@ -764,10 +761,9 @@ static struct socket *vhost_net_stop_vq(struct vhost_net *n, struct socket *sock; mutex_lock(&vq->mutex); - sock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + sock = vq->private_data; vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, NULL); + vq->private_data = NULL; mutex_unlock(&vq->mutex); return sock; } @@ -923,8 +919,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } /* start polling new socket */ - oldsock = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); + oldsock = vq->private_data; if (sock != oldsock) { ubufs = vhost_net_ubuf_alloc(vq, sock && vhost_sock_zcopy(sock)); @@ -934,7 +929,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) } vhost_net_disable_vq(n, vq); - rcu_assign_pointer(vq->private_data, sock); + vq->private_data = sock; r = vhost_init_used(vq); if (r) goto err_used; @@ -968,7 +963,7 @@ static long vhost_net_set_backend(struct vhost_net *n, unsigned index, int fd) return 0; err_used: - rcu_assign_pointer(vq->private_data, oldsock); + vq->private_data = oldsock; vhost_net_enable_vq(n, vq); if (ubufs) vhost_net_ubuf_put_wait_and_free(ubufs); diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c index 06adf31a9248..0c27c7df1b09 100644 --- a/drivers/vhost/scsi.c +++ b/drivers/vhost/scsi.c @@ -902,19 +902,15 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) int head, ret; u8 target; + mutex_lock(&vq->mutex); /* * We can handle the vq only after the endpoint is setup by calling the * VHOST_SCSI_SET_ENDPOINT ioctl. - * - * TODO: Check that we are running from vhost_worker which acts - * as read-side critical section for vhost kind of RCU. - * See the comments in struct vhost_virtqueue in drivers/vhost/vhost.h */ - vs_tpg = rcu_dereference_check(vq->private_data, 1); + vs_tpg = vq->private_data; if (!vs_tpg) - return; + goto out; - mutex_lock(&vq->mutex); vhost_disable_notify(&vs->dev, vq); for (;;) { @@ -1064,6 +1060,7 @@ err_free: vhost_scsi_free_cmd(cmd); err_cmd: vhost_scsi_send_bad_target(vs, vq, head, out); +out: mutex_unlock(&vq->mutex); } @@ -1232,9 +1229,8 @@ vhost_scsi_set_endpoint(struct vhost_scsi *vs, sizeof(vs->vs_vhost_wwpn)); for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) { vq = &vs->vqs[i].vq; - /* Flushing the vhost_work acts as synchronize_rcu */ mutex_lock(&vq->mutex); - rcu_assign_pointer(vq->private_data, vs_tpg); + vq->private_data = vs_tpg; vhost_init_used(vq); mutex_unlock(&vq->mutex); } @@ -1313,9 +1309,8 @@ vhost_scsi_clear_endpoint(struct vhost_scsi *vs, if (match) { for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) { vq = &vs->vqs[i].vq; - /* Flushing the vhost_work acts as synchronize_rcu */ mutex_lock(&vq->mutex); - rcu_assign_pointer(vq->private_data, NULL); + vq->private_data = NULL; mutex_unlock(&vq->mutex); } } diff --git a/drivers/vhost/test.c b/drivers/vhost/test.c index a73ea217f24d..339eae85859a 100644 --- a/drivers/vhost/test.c +++ b/drivers/vhost/test.c @@ -13,7 +13,6 @@ #include <linux/module.h> #include <linux/mutex.h> #include <linux/workqueue.h> -#include <linux/rcupdate.h> #include <linux/file.h> #include <linux/slab.h> @@ -200,9 +199,8 @@ static long vhost_test_run(struct vhost_test *n, int test) priv = test ? n : NULL; /* start polling new socket */ - oldpriv = rcu_dereference_protected(vq->private_data, - lockdep_is_held(&vq->mutex)); - rcu_assign_pointer(vq->private_data, priv); + oldpriv = vq->private_data; + vq->private_data = priv; r = vhost_init_used(&n->vqs[index]); diff --git a/drivers/vhost/vhost.h b/drivers/vhost/vhost.h index 42298cd23c73..4465ed5f316d 100644 --- a/drivers/vhost/vhost.h +++ b/drivers/vhost/vhost.h @@ -103,14 +103,8 @@ struct vhost_virtqueue { struct iovec iov[UIO_MAXIOV]; struct iovec *indirect; struct vring_used_elem *heads; - /* We use a kind of RCU to access private pointer. - * All readers access it from worker, which makes it possible to - * flush the vhost_work instead of synchronize_rcu. Therefore readers do - * not need to call rcu_read_lock/rcu_read_unlock: the beginning of - * vhost_work execution acts instead of rcu_read_lock() and the end of - * vhost_work execution acts instead of rcu_read_unlock(). - * Writers use virtqueue mutex. */ - void __rcu *private_data; + /* Protected by virtqueue mutex. */ + void *private_data; /* Log write descriptors */ void __user *log_base; struct vhost_log *log; |