From a73b2e25e1e2b69fb172fbb391e5bd1c3878e881 Mon Sep 17 00:00:00 2001
From: Warner Losh <imp@FreeBSD.org>
Date: Wed, 13 Feb 2019 00:10:12 +0000
Subject: [PATCH] Fix panic message.

The panic message lead people to believe some userland CAM request had
caused a problem when in reallity it was for a kernel request (eg the
USER bit was cleared). Reword message. Also, improve a couple of
comments to reflect that the periph shouldn't be completely torn down
before we get here (so the path and sim pointers should be valid, but
aren't and the code is designed to be robust enough in the face of
that to give a specific panic message).
---
 sys/cam/cam_xpt.c | 7 ++++---
 1 file changed, 4 insertions(+), 3 deletions(-)

diff --git a/sys/cam/cam_xpt.c b/sys/cam/cam_xpt.c
index 0679ca9cea49..2217ecc6d2ff 100644
--- a/sys/cam/cam_xpt.c
+++ b/sys/cam/cam_xpt.c
@@ -5411,8 +5411,9 @@ xpt_done_process(struct ccb_hdr *ccb_h)
 	}
 
 	/*
-	 * Insulate against a race where the periph is destroyed
-	 * but CCBs are still not all processed.
+	 * Insulate against a race where the periph is destroyed but CCBs are
+	 * still not all processed. This shouldn't happen, but allows us better
+	 * bug diagnostic when it does.
 	 */
 	if (ccb_h->path->bus)
 		sim = ccb_h->path->bus->sim;
@@ -5434,7 +5435,7 @@ xpt_done_process(struct ccb_hdr *ccb_h)
 
 		if (sim)
 			devq = sim->devq;
-		KASSERT(devq, ("sim missing for XPT_FC_USER_CCB request"));
+		KASSERT(devq, ("Periph disappeared with request pending."));
 
 		mtx_lock(&devq->send_mtx);
 		devq->send_active--;