svn commit: r249157 - stable/9/sys/cam/scsi

[Alexander Motin]

Author: mav
Date: Fri Apr  5 11:52:33 2013
New Revision: 249157
URL: http://svnweb.freebsd.org/changeset/base/249157

Log:
  MFC r245306:
  Do not schedule periph for payload/TUR requests if reprobe is in progress
  to avoid sending extra READ CAPACITY requests by dastart().  Schedule periph
  again on reprobe completion, or otherwise it may stuck indefinitely long.
  
  This should fix USB explore thread hanging on device unplug, waiting for
  periph destruction.

Modified:
  stable/9/sys/cam/scsi/scsi_da.c
Directory Properties:
  stable/9/sys/   (props changed)

Modified: stable/9/sys/cam/scsi/scsi_da.c
==============================================================================
--- stable/9/sys/cam/scsi/scsi_da.c	Fri Apr  5 11:50:05 2013	(r249156)
+++ stable/9/sys/cam/scsi/scsi_da.c	Fri Apr  5 11:52:33 2013	(r249157)
@@ -1081,6 +1081,9 @@ daschedule(struct cam_periph *periph)
 	struct da_softc *softc = (struct da_softc *)periph->softc;
 	uint32_t prio;
 
+	if (softc->state != DA_STATE_NORMAL)
+		return;
+
 	/* Check if cam_periph_getccb() was called. */
 	prio = periph->immediate_priority;
 
@@ -1425,10 +1428,10 @@ daasync(void *callback_arg, u_int32_t co
 	}
 	case AC_SCSI_AEN:
 		softc = (struct da_softc *)periph->softc;
-		if (softc->state == DA_STATE_NORMAL && !softc->tur) {
+		if (!softc->tur) {
 			if (cam_periph_acquire(periph) == CAM_REQ_CMP) {
 				softc->tur = 1;
-				xpt_schedule(periph, CAM_PRIORITY_DEV);
+				daschedule(periph);
 			}
 		}
 		/* FALLTHROUGH */
@@ -2167,6 +2170,7 @@ dadone(struct cam_periph *periph, union 
 	struct da_softc *softc;
 	struct ccb_scsiio *csio;
 	u_int32_t  priority;
+	da_ccb_state state;
 
 	softc = (struct da_softc *)periph->softc;
 	priority = done_ccb->ccb_h.pinfo.priority;
@@ -2174,7 +2178,8 @@ dadone(struct cam_periph *periph, union 
 	CAM_DEBUG(periph->path, CAM_DEBUG_TRACE, ("dadone\n"));
 
 	csio = &done_ccb->csio;
-	switch (csio->ccb_h.ccb_state & DA_CCB_TYPE_MASK) {
+	state = csio->ccb_h.ccb_state & DA_CCB_TYPE_MASK;
+	switch (state) {
 	case DA_CCB_BUFFER_IO:
 	case DA_CCB_DELETE:
 	{
@@ -2272,8 +2277,7 @@ dadone(struct cam_periph *periph, union 
 				  softc->outstanding_cmds);
 		}
 
-		if ((csio->ccb_h.ccb_state & DA_CCB_TYPE_MASK) ==
-		    DA_CCB_DELETE) {
+		if (state == DA_CCB_DELETE) {
 			while ((bp1 = bioq_takefirst(&softc->delete_run_queue))
 			    != NULL) {
 				bp1->bio_resid = bp->bio_resid;
@@ -2299,7 +2303,7 @@ dadone(struct cam_periph *periph, union 
 
 		rdcap = NULL;
 		rcaplong = NULL;
-		if (softc->state == DA_STATE_PROBE)
+		if (state == DA_CCB_PROBE)
 			rdcap =(struct scsi_read_capacity_data *)csio->data_ptr;
 		else
 			rcaplong = (struct scsi_read_capacity_data_long *)
@@ -2312,7 +2316,7 @@ dadone(struct cam_periph *periph, union 
 			u_int lbppbe;	/* LB per physical block exponent. */
 			u_int lalba;	/* Lowest aligned LBA. */
 
-			if (softc->state == DA_STATE_PROBE) {
+			if (state == DA_CCB_PROBE) {
 				block_size = scsi_4btoul(rdcap->length);
 				maxsector = scsi_4btoul(rdcap->addr);
 				lbppbe = 0;
@@ -2425,7 +2429,7 @@ dadone(struct cam_periph *periph, union 
 				 * If we tried READ CAPACITY(16) and failed,
 				 * fallback to READ CAPACITY(10).
 				 */
-				if ((softc->state == DA_STATE_PROBE2) &&
+				if ((state == DA_CCB_PROBE2) &&
 				    (softc->flags & DA_FLAG_CAN_RC16) &&
 				    (((csio->ccb_h.status & CAM_STATUS_MASK) ==
 					CAM_REQ_INVALID) ||
@@ -2505,7 +2509,8 @@ dadone(struct cam_periph *periph, union 
 		 * operation.
 		 */
 		xpt_release_ccb(done_ccb);
-		softc->state = DA_STATE_NORMAL;	
+		softc->state = DA_STATE_NORMAL;
+		daschedule(periph);
 		wakeup(&softc->disk->d_mediasize);
 		if ((softc->flags & DA_FLAG_PROBED) == 0) {
 			softc->flags |= DA_FLAG_PROBED;
@@ -2630,7 +2635,7 @@ damediapoll(void *arg)
 	struct cam_periph *periph = arg;
 	struct da_softc *softc = periph->softc;
 
-	if (softc->state == DA_STATE_NORMAL && !softc->tur) {
+	if (!softc->tur && softc->outstanding_cmds == 0) {
 		if (cam_periph_acquire(periph) == CAM_REQ_CMP) {
 			softc->tur = 1;
 			daschedule(periph);