Do not reread SCSI disk VPD pages on every device open.

Instead of rereading VPD pages on every device open, do it only on initial
device probe, and in cases when device reported via UNIT ATTENTIONs that
something has changed.  Capacity is still rereaded on every open because
it is more critical for operation and more probable to change in run time.

On my tests with Intel 530 SSDs on mps(4) HBA this change reduces time
GEOM needs to retaste the device (that includes few open/close cycles)
from ~150ms to ~30ms.

MFC after:	2 weeks
Sponsored by:	iXsystems, Inc.

1 files changed, 35 insertions, 10 deletions

diff --git a/sys/cam/scsi/scsi_da.c b/sys/cam/scsi/scsi_da.c
index 2faa8dd..0015231 100644
--- a/sys/cam/scsi/scsi_da.c
+++ b/sys/cam/scsi/scsi_da.c
@@ -90,7 +90,8 @@ typedef enum {
 	DA_FLAG_SCTX_INIT	= 0x200,
 	DA_FLAG_CAN_RC16	= 0x400,
 	DA_FLAG_PROBED		= 0x800,
-	DA_FLAG_DIRTY		= 0x1000
+	DA_FLAG_DIRTY		= 0x1000,
+	DA_FLAG_ANNOUNCED	= 0x2000
 } da_flags;
 
 typedef enum {
@@ -1658,10 +1659,18 @@ daasync(void *callback_arg, u_int32_t code,
 		     &error_code, &sense_key, &asc, &ascq)) {
 			if (asc == 0x2A && ascq == 0x09) {
 				xpt_print(ccb->ccb_h.path,
-				    "capacity data has changed\n");
+				    "Capacity data has changed\n");
+				softc->flags &= ~DA_FLAG_PROBED;
 				dareprobe(periph);
-			} else if (asc == 0x28 && ascq == 0x00)
+			} else if (asc == 0x28 && ascq == 0x00) {
+				softc->flags &= ~DA_FLAG_PROBED;
 				disk_media_changed(softc->disk, M_NOWAIT);
+			} else if (asc == 0x3F && ascq == 0x03) {
+				xpt_print(ccb->ccb_h.path,
+				    "INQUIRY data has changed\n");
+				softc->flags &= ~DA_FLAG_PROBED;
+				dareprobe(periph);
+			}
 		}
 		cam_periph_async(periph, code, path, arg);
 		break;
@@ -1891,7 +1900,7 @@ daprobedone(struct cam_periph *periph, union ccb *ccb)
 
 	dadeletemethodchoose(softc, DA_DELETE_NONE);
 
-	if (bootverbose && (softc->flags & DA_FLAG_PROBED) == 0) {
+	if (bootverbose && (softc->flags & DA_FLAG_ANNOUNCED) == 0) {
 		char buf[80];
 		int i, sep;
 
@@ -1932,10 +1941,11 @@ daprobedone(struct cam_periph *periph, union ccb *ccb)
 	 */
 	xpt_release_ccb(ccb);
 	softc->state = DA_STATE_NORMAL;
+	softc->flags |= DA_FLAG_PROBED;
 	daschedule(periph);
 	wakeup(&softc->disk->d_mediasize);
-	if ((softc->flags & DA_FLAG_PROBED) == 0) {
-		softc->flags |= DA_FLAG_PROBED;
+	if ((softc->flags & DA_FLAG_ANNOUNCED) == 0) {
+		softc->flags |= DA_FLAG_ANNOUNCED;
 		cam_periph_unhold(periph);
 	} else
 		cam_periph_release_locked(periph);
@@ -3190,7 +3200,8 @@ dadone(struct cam_periph *periph, union ccb *done_ccb)
 			}
 		}
 		free(csio->data_ptr, M_SCSIDA);
-		if (announce_buf[0] != '\0' && ((softc->flags & DA_FLAG_PROBED) == 0)) {
+		if (announce_buf[0] != '\0' &&
+		    ((softc->flags & DA_FLAG_ANNOUNCED) == 0)) {
 			/*
 			 * Create our sysctl variables, now that we know
 			 * we have successfully attached.
@@ -3208,6 +3219,12 @@ dadone(struct cam_periph *periph, union ccb *done_ccb)
 			}
 		}
 
+		/* We already probed the device. */
+		if (softc->flags & DA_FLAG_PROBED) {
+			daprobedone(periph, done_ccb);
+			return;
+		}
+
 		/* Ensure re-probe doesn't see old delete. */
 		softc->delete_available = 0;
 		if (lbp && (softc->quirks & DA_Q_NO_UNMAP) == 0) {
@@ -3546,13 +3563,21 @@ daerror(union ccb *ccb, u_int32_t cam_flags, u_int32_t sense_flags)
 		 */
 		else if (sense_key == SSD_KEY_UNIT_ATTENTION &&
 		    asc == 0x2A && ascq == 0x09) {
-			xpt_print(periph->path, "capacity data has changed\n");
+			xpt_print(periph->path, "Capacity data has changed\n");
+			softc->flags &= ~DA_FLAG_PROBED;
 			dareprobe(periph);
 			sense_flags |= SF_NO_PRINT;
 		} else if (sense_key == SSD_KEY_UNIT_ATTENTION &&
-		    asc == 0x28 && ascq == 0x00)
+		    asc == 0x28 && ascq == 0x00) {
+			softc->flags &= ~DA_FLAG_PROBED;
 			disk_media_changed(softc->disk, M_NOWAIT);
-		else if (sense_key == SSD_KEY_NOT_READY &&
+		} else if (sense_key == SSD_KEY_UNIT_ATTENTION &&
+		    asc == 0x3F && ascq == 0x03) {
+			xpt_print(periph->path, "INQUIRY data has changed\n");
+			softc->flags &= ~DA_FLAG_PROBED;
+			dareprobe(periph);
+			sense_flags |= SF_NO_PRINT;
+		} else if (sense_key == SSD_KEY_NOT_READY &&
 		    asc == 0x3a && (softc->flags & DA_FLAG_PACK_INVALID) == 0) {
 			softc->flags |= DA_FLAG_PACK_INVALID;
 			disk_media_gone(softc->disk, M_NOWAIT);