svn commit: r362339 - stable/12/sys/dev/nvme

[Alexander Motin]

Author: mav
Date: Thu Jun 18 20:23:46 2020
New Revision: 362339
URL: https://svnweb.freebsd.org/changeset/base/362339

Log:
  MFC r360503 (by imp): Move / reword a comment.
  
  Explain what we're doing with mapping CAM's notion of a LUN to NVMe's
  notion of a namespace.

Modified:
  stable/12/sys/dev/nvme/nvme_sim.c
Directory Properties:
  stable/12/   (props changed)

Modified: stable/12/sys/dev/nvme/nvme_sim.c
==============================================================================
--- stable/12/sys/dev/nvme/nvme_sim.c	Thu Jun 18 19:32:34 2020	(r362338)
+++ stable/12/sys/dev/nvme/nvme_sim.c	Thu Jun 18 20:23:46 2020	(r362339)
@@ -172,12 +172,6 @@ nvme_sim_action(struct cam_sim *sim, union ccb *ccb)
 		struct ccb_pathinq	*cpi = &ccb->cpi;
 		device_t		dev = ctrlr->dev;
 
-		/*
-		 * NVMe may have multiple LUNs on the same path. Current generation
-		 * of NVMe devives support only a single name space. Multiple name
-		 * space drives are coming, but it's unclear how we should report
-		 * them up the stack.
-		 */
 		cpi->version_num = 1;
 		cpi->hba_inquiry = 0;
 		cpi->target_sprt = 0;
@@ -330,13 +324,17 @@ nvme_sim_new_ns(struct nvme_namespace *ns, void *sc_ar
 		return (NULL);
 	}
 
+	/*
+	 * We map the NVMe namespace idea onto the CAM unit LUN. For
+	 * each new namespace, we create a new CAM path for it. We then
+	 * rescan the path to get it to enumerate.
+	 */
 	if (xpt_create_path(&ccb->ccb_h.path, /*periph*/NULL,
 	    cam_sim_path(sc->s_sim), 0, ns->id) != CAM_REQ_CMP) {
 		printf("unable to create path for rescan\n");
 		xpt_free_ccb(ccb);
 		return (NULL);
 	}
-
 	xpt_rescan(ccb);
 
 	return (ns);