X-Git-Url: http://git.cascardo.info/?a=blobdiff_plain;f=drivers%2Fvhost%2Ftcm_vhost.c;h=957a0b98a5d90f689c68fb92ba76e60c72f89944;hb=bb33db7a076f4719dc68c235e187dd4bfb16b621;hp=2968b4934659aab01dd626334a9ab7fc0e607383;hpb=cd0e4a9dd432b2f0209d84b5b2420695c1fd3eb7;p=cascardo%2Flinux.git diff --git a/drivers/vhost/tcm_vhost.c b/drivers/vhost/tcm_vhost.c index 2968b4934659..957a0b98a5d9 100644 --- a/drivers/vhost/tcm_vhost.c +++ b/drivers/vhost/tcm_vhost.c @@ -74,9 +74,8 @@ enum { 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]; @@ -579,9 +578,27 @@ static void tcm_vhost_submission_work(struct work_struct *work) } } +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; @@ -590,8 +607,16 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, 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); @@ -661,23 +686,11 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, /* 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; } @@ -690,22 +703,13 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, 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; /* @@ -725,7 +729,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, " 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; @@ -738,7 +742,7 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, data_direction == DMA_TO_DEVICE); if (unlikely(ret)) { vq_err(vq, "Failed to map iov to sgl\n"); - break; /* TODO */ + goto err_free; } } @@ -759,6 +763,13 @@ static void vhost_scsi_handle_vq(struct vhost_scsi *vs, } 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) @@ -780,6 +791,20 @@ static void vhost_scsi_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 @@ -790,8 +815,10 @@ static int vhost_scsi_set_endpoint( { 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. */ @@ -803,6 +830,15 @@ static int vhost_scsi_set_endpoint( } } + 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); @@ -817,14 +853,15 @@ static int vhost_scsi_set_endpoint( 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; } @@ -835,12 +872,27 @@ static int vhost_scsi_set_endpoint( 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; } @@ -851,6 +903,8 @@ static int vhost_scsi_clear_endpoint( { 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; @@ -862,9 +916,14 @@ static int vhost_scsi_clear_endpoint( 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; @@ -886,10 +945,27 @@ static int vhost_scsi_clear_endpoint( } 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: @@ -899,6 +975,24 @@ err_dev: 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; @@ -939,38 +1033,6 @@ static int vhost_scsi_release(struct inode *inode, struct file *f) 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) {