[PATCH 2/9] vhost-scsi: adjust vhost_scsi_get_desc() to log vring descriptors

[Dongli Zhang]

Adjust vhost_scsi_get_desc() to facilitate logging of vring descriptors.

Add new arguments to allow passing the log buffer and length to
vhost_get_vq_desc().

In addition, reset 'log_num' since vhost_get_vq_desc() may reset it only
after certain condition checks.

Suggested-by: Joao Martins <joao.m.mart...@oracle.com>
Signed-off-by: Dongli Zhang <dongli.zh...@oracle.com>
---
 drivers/vhost/scsi.c | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/drivers/vhost/scsi.c b/drivers/vhost/scsi.c
index 718fa4e0b31e..ee2310555740 100644
--- a/drivers/vhost/scsi.c
+++ b/drivers/vhost/scsi.c
@@ -950,13 +950,17 @@ vhost_scsi_send_bad_target(struct vhost_scsi *vs,
 
 static int
 vhost_scsi_get_desc(struct vhost_scsi *vs, struct vhost_virtqueue *vq,
-                   struct vhost_scsi_ctx *vc)
+                   struct vhost_scsi_ctx *vc,
+                   struct vhost_log *log, unsigned int *log_num)
 {
        int ret = -ENXIO;
 
+       if (likely(log_num))
+               *log_num = 0;
+
        vc->head = vhost_get_vq_desc(vq, vq->iov,
                                     ARRAY_SIZE(vq->iov), &vc->out, &vc->in,
-                                    NULL, NULL);
+                                    log, log_num);
 
        pr_debug("vhost_get_vq_desc: head: %d, out: %u in: %u\n",
                 vc->head, vc->out, vc->in);
@@ -1086,7 +1090,7 @@ vhost_scsi_handle_vq(struct vhost_scsi *vs, struct 
vhost_virtqueue *vq)
        vhost_disable_notify(&vs->dev, vq);
 
        do {
-               ret = vhost_scsi_get_desc(vs, vq, &vc);
+               ret = vhost_scsi_get_desc(vs, vq, &vc, NULL, NULL);
                if (ret)
                        goto err;
 
@@ -1411,7 +1415,7 @@ vhost_scsi_ctl_handle_vq(struct vhost_scsi *vs, struct 
vhost_virtqueue *vq)
        vhost_disable_notify(&vs->dev, vq);
 
        do {
-               ret = vhost_scsi_get_desc(vs, vq, &vc);
+               ret = vhost_scsi_get_desc(vs, vq, &vc, NULL, NULL);
                if (ret)
                        goto err;
 
-- 
2.39.3