Fix insta-panic on assert of unlocked periph mtx in ciss(4) when

logical volume state changes.

Currently, I view this as a critical fix for users and will MFC this rapidly as
my testing has shown data loss when the disk is failed by removing it when
under some amount of write activity and this code panics the box.

Reviewed by:	mav@ scottl@
MFC after:	3 days
Sponsored by:	Yahoo! Inc.

1 files changed, 11 insertions, 24 deletions

diff --git a/sys/dev/ciss/ciss.c b/sys/dev/ciss/ciss.c
index bb84726..c8dee70 100644
--- a/sys/dev/ciss/ciss.c
+++ b/sys/dev/ciss/ciss.c
@@ -180,8 +180,6 @@ static int	ciss_cam_emulate(struct ciss_softc *sc, struct ccb_scsiio *csio);
 static void	ciss_cam_poll(struct cam_sim *sim);
 static void	ciss_cam_complete(struct ciss_request *cr);
 static void	ciss_cam_complete_fixup(struct ciss_softc *sc, struct ccb_scsiio *csio);
-static struct cam_periph *ciss_find_periph(struct ciss_softc *sc,
-					   int bus, int target);
 static int	ciss_name_device(struct ciss_softc *sc, int bus, int target);
 
 /* periodic status monitoring */
@@ -3413,27 +3411,6 @@ ciss_cam_complete_fixup(struct ciss_softc *sc, struct ccb_scsiio *csio)
 
 
 /********************************************************************************
- * Find a peripheral attached at (target)
- */
-static struct cam_periph *
-ciss_find_periph(struct ciss_softc *sc, int bus, int target)
-{
-    struct cam_periph	*periph;
-    struct cam_path	*path;
-    int			status;
-
-    status = xpt_create_path(&path, NULL, cam_sim_path(sc->ciss_cam_sim[bus]),
-			     target, 0);
-    if (status == CAM_REQ_CMP) {
-	periph = cam_periph_find(path, NULL);
-	xpt_free_path(path);
-    } else {
-	periph = NULL;
-    }
-    return(periph);
-}
-
-/********************************************************************************
  * Name the device at (target)
  *
  * XXX is this strictly correct?
@@ -3442,12 +3419,22 @@ static int
 ciss_name_device(struct ciss_softc *sc, int bus, int target)
 {
     struct cam_periph	*periph;
+    struct cam_path	*path;
+    int			status;
 
     if (CISS_IS_PHYSICAL(bus))
 	return (0);
-    if ((periph = ciss_find_periph(sc, bus, target)) != NULL) {
+
+    status = xpt_create_path(&path, NULL, cam_sim_path(sc->ciss_cam_sim[bus]),
+			     target, 0);
+
+    if (status == CAM_REQ_CMP) {
+	xpt_path_lock(path);
+	periph = cam_periph_find(path, NULL);
 	sprintf(sc->ciss_logical[bus][target].cl_name, "%s%d",
 		periph->periph_name, periph->unit_number);
+	xpt_path_unlock(path);
+	xpt_free_path(path);
 	return(0);
     }
     sc->ciss_logical[bus][target].cl_name[0] = 0;