Commit 79c14141 authored by Nicholas Bellinger's avatar Nicholas Bellinger
Browse files

vhost/scsi: Convert completion path to use copy_to_iter 



Required for ANY_LAYOUT support when the incoming virtio-scsi response
header + fixed size sense buffer payload may span more than a single
iovec entry.

This changes existing code to save cmd->tvc_resp_iov instead of the
first single iovec base pointer from &vq->iov[out].

Cc: Michael S. Tsirkin <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>
Cc: Al Viro <viro@zeniv.linux.org.uk>
Signed-off-by: default avatarNicholas Bellinger <nab@linux-iscsi.org>
parent b44a2b67

drivers/vhost/scsi.c

+12 −5
Original line number Diff line number Diff line
@@ -72,6 +72,8 @@ struct tcm_vhost_cmd { 
	int tvc_vq_desc;

	/* virtio-scsi initiator task attribute */

	int tvc_task_attr;

	/* virtio-scsi response incoming iovecs */

	int tvc_in_iovs;

	/* virtio-scsi initiator data direction */

	enum dma_data_direction tvc_data_direction;

	/* Expected data transfer length from virtio-scsi header */
@@ -87,8 +89,8 @@ struct tcm_vhost_cmd { 
	struct scatterlist *tvc_sgl;

	struct scatterlist *tvc_prot_sgl;

	struct page **tvc_upages;

	/* Pointer to response */

	struct virtio_scsi_cmd_resp __user *tvc_resp;

	/* Pointer to response header iovec */

	struct iovec *tvc_resp_iov;

	/* Pointer to vhost_scsi for our device */

	struct vhost_scsi *tvc_vhost;

	/* Pointer to vhost_virtqueue for the cmd */
@@ -682,6 +684,7 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) 
	struct tcm_vhost_cmd *cmd;

	struct llist_node *llnode;

	struct se_cmd *se_cmd;

	struct iov_iter iov_iter;

	int ret, vq;



	bitmap_zero(signal, VHOST_SCSI_MAX_VQ);
@@ -703,8 +706,11 @@ static void vhost_scsi_complete_cmd_work(struct vhost_work *work) 
						 se_cmd->scsi_sense_length);

		memcpy(v_rsp.sense, cmd->tvc_sense_buf,

		       se_cmd->scsi_sense_length);

		ret = copy_to_user(cmd->tvc_resp, &v_rsp, sizeof(v_rsp));

		if (likely(ret == 0)) {



		iov_iter_init(&iov_iter, READ, cmd->tvc_resp_iov,

			      cmd->tvc_in_iovs, sizeof(v_rsp));

		ret = copy_to_iter(&v_rsp, sizeof(v_rsp), &iov_iter);

		if (likely(ret == sizeof(v_rsp))) {

			struct vhost_scsi_virtqueue *q;

			vhost_add_used(cmd->tvc_vq, cmd->tvc_vq_desc, 0);

			q = container_of(cmd->tvc_vq, struct vhost_scsi_virtqueue, vq);
@@ -1159,7 +1165,8 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct vhost_virtqueue *vq) 


		cmd->tvc_vhost = vs;

		cmd->tvc_vq = vq;

		cmd->tvc_resp = vq->iov[out].iov_base;

		cmd->tvc_resp_iov = &vq->iov[out];

		cmd->tvc_in_iovs = in;



		pr_debug("vhost_scsi got command opcode: %#02x, lun: %d\n",

			cmd->tvc_cdb[0], cmd->tvc_lun);

CRA Git | Maintained and supported by SUSTech CRA and CCSE