svn commit: r328089 - head/sys/dev/nvme

[Warner Losh]

Author: imp
Date: Wed Jan 17 17:08:26 2018
New Revision: 328089
URL: https://svnweb.freebsd.org/changeset/base/328089

Log:
  Move setting of CAM_SIM_QUEUED to before we actually submit it to the
  hardware. Setting it after is racy, and we can lose the race on a
  heavily loaded system.
  
  Reviewed by: scottl@, gallatin@
  Sponsored by: Netflix

Modified:
  head/sys/dev/nvme/nvme_sim.c

Modified: head/sys/dev/nvme/nvme_sim.c
==============================================================================
--- head/sys/dev/nvme/nvme_sim.c	Wed Jan 17 16:55:35 2018	(r328088)
+++ head/sys/dev/nvme/nvme_sim.c	Wed Jan 17 17:08:26 2018	(r328089)
@@ -76,6 +76,7 @@ nvme_sim_nvmeio_done(void *ccb_arg, const struct nvme_
 	 * it means. Make our best guess, though for the status code.
 	 */
 	memcpy(&ccb->nvmeio.cpl, cpl, sizeof(*cpl));
+	ccb->ccb_h.status &= ~CAM_SIM_QUEUED;
 	if (nvme_completion_is_error(cpl)) {
 		ccb->ccb_h.status = CAM_REQ_CMP_ERR;
 		xpt_done(ccb);
@@ -114,6 +115,7 @@ nvme_sim_nvmeio(struct cam_sim *sim, union ccb *ccb)
 		xpt_done(ccb);
 		return;
 	}
+	ccb->ccb_h.status |= CAM_SIM_QUEUED;
 
 	memcpy(&req->cmd, &ccb->nvmeio.cmd, sizeof(ccb->nvmeio.cmd));
 
@@ -121,8 +123,6 @@ nvme_sim_nvmeio(struct cam_sim *sim, union ccb *ccb)
 		nvme_ctrlr_submit_io_request(ctrlr, req);
 	else
 		nvme_ctrlr_submit_admin_request(ctrlr, req);
-
-	ccb->ccb_h.status |= CAM_SIM_QUEUED;
 }
 
 static uint32_t