struct vhost_scsi {
/* Protected by vhost_scsi->dev.mutex */
- struct tcm_vhost_tpg *vs_tpg[VHOST_SCSI_MAX_TARGET];
+ struct tcm_vhost_tpg **vs_tpg;
char vs_vhost_wwpn[TRANSPORT_IQN_LEN];
- bool vs_endpoint;
struct vhost_dev dev;
struct vhost_virtqueue vqs[VHOST_SCSI_MAX_VQ];
}
}
+static void vhost_scsi_send_bad_target(struct vhost_scsi *vs,
+ struct vhost_virtqueue *vq, int head, unsigned out)
+{
+ struct virtio_scsi_cmd_resp __user *resp;
+ struct virtio_scsi_cmd_resp rsp;
+ int ret;
+
+ memset(&rsp, 0, sizeof(rsp));
+ rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
+ resp = vq->iov[out].iov_base;
+ ret = __copy_to_user(resp, &rsp, sizeof(rsp));
+ if (!ret)
+ vhost_add_used_and_signal(&vs->dev, vq, head, 0);
+ else
+ pr_err("Faulted on virtio_scsi_cmd_resp\n");
+}
+
static void vhost_scsi_handle_vq(struct vhost_scsi *vs,
struct vhost_virtqueue *vq)
{
+ struct tcm_vhost_tpg **vs_tpg;
struct virtio_scsi_cmd_req v_req;
struct tcm_vhost_tpg *tv_tpg;
struct tcm_vhost_cmd *tv_cmd;
int head, ret;
u8 target;
- /* Must use ioctl VHOST_SCSI_SET_ENDPOINT */
- if (unlikely(!vs->vs_endpoint))
+ /*
+ * 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);
+ if (!vs_tpg)
return;
mutex_lock(&vq->mutex);
/* Extract the tpgt */
target = v_req.lun[1];
- tv_tpg = vs->vs_tpg[target];
+ tv_tpg = ACCESS_ONCE(vs_tpg[target]);
/* Target does not exist, fail the request */
if (unlikely(!tv_tpg)) {
- struct virtio_scsi_cmd_resp __user *resp;
- struct virtio_scsi_cmd_resp rsp;
-
- memset(&rsp, 0, sizeof(rsp));
- rsp.response = VIRTIO_SCSI_S_BAD_TARGET;
- resp = vq->iov[out].iov_base;
- ret = __copy_to_user(resp, &rsp, sizeof(rsp));
- if (!ret)
- vhost_add_used_and_signal(&vs->dev,
- vq, head, 0);
- else
- pr_err("Faulted on virtio_scsi_cmd_resp\n");
-
+ vhost_scsi_send_bad_target(vs, vq, head, out);
continue;
}
if (IS_ERR(tv_cmd)) {
vq_err(vq, "vhost_scsi_allocate_cmd failed %ld\n",
PTR_ERR(tv_cmd));
- break;
+ goto err_cmd;
}
pr_debug("Allocated tv_cmd: %p exp_data_len: %d, data_direction"
": %d\n", tv_cmd, exp_data_len, data_direction);
tv_cmd->tvc_vhost = vs;
tv_cmd->tvc_vq = vq;
-
- if (unlikely(vq->iov[out].iov_len !=
- sizeof(struct virtio_scsi_cmd_resp))) {
- vq_err(vq, "Expecting virtio_scsi_cmd_resp, got %zu"
- " bytes, out: %d, in: %d\n",
- vq->iov[out].iov_len, out, in);
- break;
- }
-
tv_cmd->tvc_resp = vq->iov[out].iov_base;
/*
" exceeds SCSI_MAX_VARLEN_CDB_SIZE: %d\n",
scsi_command_size(tv_cmd->tvc_cdb),
TCM_VHOST_MAX_CDB_SIZE);
- break; /* TODO */
+ goto err_free;
}
tv_cmd->tvc_lun = ((v_req.lun[2] << 8) | v_req.lun[3]) & 0x3FFF;
data_direction == DMA_TO_DEVICE);
if (unlikely(ret)) {
vq_err(vq, "Failed to map iov to sgl\n");
- break; /* TODO */
+ goto err_free;
}
}
}
mutex_unlock(&vq->mutex);
+ return;
+
+err_free:
+ vhost_scsi_free_cmd(tv_cmd);
+err_cmd:
+ vhost_scsi_send_bad_target(vs, vq, head, out);
+ mutex_unlock(&vq->mutex);
}
static void vhost_scsi_ctl_handle_kick(struct vhost_work *work)
vhost_scsi_handle_vq(vs, vq);
}
+static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
+{
+ vhost_poll_flush(&vs->dev.vqs[index].poll);
+}
+
+static void vhost_scsi_flush(struct vhost_scsi *vs)
+{
+ int i;
+
+ for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
+ vhost_scsi_flush_vq(vs, i);
+ vhost_work_flush(&vs->dev, &vs->vs_completion_work);
+}
+
/*
* Called from vhost_scsi_ioctl() context to walk the list of available
* tcm_vhost_tpg with an active struct tcm_vhost_nexus
{
struct tcm_vhost_tport *tv_tport;
struct tcm_vhost_tpg *tv_tpg;
+ struct tcm_vhost_tpg **vs_tpg;
+ struct vhost_virtqueue *vq;
+ int index, ret, i, len;
bool match = false;
- int index, ret;
mutex_lock(&vs->dev.mutex);
/* Verify that ring has been setup correctly. */
}
}
+ len = sizeof(vs_tpg[0]) * VHOST_SCSI_MAX_TARGET;
+ vs_tpg = kzalloc(len, GFP_KERNEL);
+ if (!vs_tpg) {
+ mutex_unlock(&vs->dev.mutex);
+ return -ENOMEM;
+ }
+ if (vs->vs_tpg)
+ memcpy(vs_tpg, vs->vs_tpg, len);
+
mutex_lock(&tcm_vhost_mutex);
list_for_each_entry(tv_tpg, &tcm_vhost_list, tv_tpg_list) {
mutex_lock(&tv_tpg->tv_tpg_mutex);
tv_tport = tv_tpg->tport;
if (!strcmp(tv_tport->tport_name, t->vhost_wwpn)) {
- if (vs->vs_tpg[tv_tpg->tport_tpgt]) {
+ if (vs->vs_tpg && vs->vs_tpg[tv_tpg->tport_tpgt]) {
mutex_unlock(&tv_tpg->tv_tpg_mutex);
mutex_unlock(&tcm_vhost_mutex);
mutex_unlock(&vs->dev.mutex);
+ kfree(vs_tpg);
return -EEXIST;
}
tv_tpg->tv_tpg_vhost_count++;
- vs->vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
+ vs_tpg[tv_tpg->tport_tpgt] = tv_tpg;
smp_mb__after_atomic_inc();
match = true;
}
if (match) {
memcpy(vs->vs_vhost_wwpn, t->vhost_wwpn,
sizeof(vs->vs_vhost_wwpn));
- vs->vs_endpoint = true;
+ for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
+ vq = &vs->vqs[i];
+ /* Flushing the vhost_work acts as synchronize_rcu */
+ mutex_lock(&vq->mutex);
+ rcu_assign_pointer(vq->private_data, vs_tpg);
+ vhost_init_used(vq);
+ mutex_unlock(&vq->mutex);
+ }
ret = 0;
} else {
ret = -EEXIST;
}
+ /*
+ * Act as synchronize_rcu to make sure access to
+ * old vs->vs_tpg is finished.
+ */
+ vhost_scsi_flush(vs);
+ kfree(vs->vs_tpg);
+ vs->vs_tpg = vs_tpg;
+
mutex_unlock(&vs->dev.mutex);
return ret;
}
{
struct tcm_vhost_tport *tv_tport;
struct tcm_vhost_tpg *tv_tpg;
+ struct vhost_virtqueue *vq;
+ bool match = false;
int index, ret, i;
u8 target;
goto err_dev;
}
}
+
+ if (!vs->vs_tpg) {
+ mutex_unlock(&vs->dev.mutex);
+ return 0;
+ }
+
for (i = 0; i < VHOST_SCSI_MAX_TARGET; i++) {
target = i;
-
tv_tpg = vs->vs_tpg[target];
if (!tv_tpg)
continue;
}
tv_tpg->tv_tpg_vhost_count--;
vs->vs_tpg[target] = NULL;
- vs->vs_endpoint = false;
+ match = true;
mutex_unlock(&tv_tpg->tv_tpg_mutex);
}
+ if (match) {
+ for (i = 0; i < VHOST_SCSI_MAX_VQ; i++) {
+ vq = &vs->vqs[i];
+ /* Flushing the vhost_work acts as synchronize_rcu */
+ mutex_lock(&vq->mutex);
+ rcu_assign_pointer(vq->private_data, NULL);
+ mutex_unlock(&vq->mutex);
+ }
+ }
+ /*
+ * Act as synchronize_rcu to make sure access to
+ * old vs->vs_tpg is finished.
+ */
+ vhost_scsi_flush(vs);
+ kfree(vs->vs_tpg);
+ vs->vs_tpg = NULL;
mutex_unlock(&vs->dev.mutex);
+
return 0;
err_tpg:
return ret;
}
+static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
+{
+ if (features & ~VHOST_SCSI_FEATURES)
+ return -EOPNOTSUPP;
+
+ mutex_lock(&vs->dev.mutex);
+ if ((features & (1 << VHOST_F_LOG_ALL)) &&
+ !vhost_log_access_ok(&vs->dev)) {
+ mutex_unlock(&vs->dev.mutex);
+ return -EFAULT;
+ }
+ vs->dev.acked_features = features;
+ smp_wmb();
+ vhost_scsi_flush(vs);
+ mutex_unlock(&vs->dev.mutex);
+ return 0;
+}
+
static int vhost_scsi_open(struct inode *inode, struct file *f)
{
struct vhost_scsi *s;
return 0;
}
-static void vhost_scsi_flush_vq(struct vhost_scsi *vs, int index)
-{
- vhost_poll_flush(&vs->dev.vqs[index].poll);
-}
-
-static void vhost_scsi_flush(struct vhost_scsi *vs)
-{
- int i;
-
- for (i = 0; i < VHOST_SCSI_MAX_VQ; i++)
- vhost_scsi_flush_vq(vs, i);
- vhost_work_flush(&vs->dev, &vs->vs_completion_work);
-}
-
-static int vhost_scsi_set_features(struct vhost_scsi *vs, u64 features)
-{
- if (features & ~VHOST_SCSI_FEATURES)
- return -EOPNOTSUPP;
-
- mutex_lock(&vs->dev.mutex);
- if ((features & (1 << VHOST_F_LOG_ALL)) &&
- !vhost_log_access_ok(&vs->dev)) {
- mutex_unlock(&vs->dev.mutex);
- return -EFAULT;
- }
- vs->dev.acked_features = features;
- smp_wmb();
- vhost_scsi_flush(vs);
- mutex_unlock(&vs->dev.mutex);
- return 0;
-}
-
static long vhost_scsi_ioctl(struct file *f, unsigned int ioctl,
unsigned long arg)
{
projects / firefly-linux-kernel-4.4.55.git / blobdiff