[src/trunk]: src/sys/dev/scsipi Wait in detach if the discovery thread is sti...

[mlelstv <mlelstv%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/a82db9aec88c
branches:  trunk
changeset: 366534:a82db9aec88c
user:      mlelstv <mlelstv%NetBSD.org@localhost>
date:      Sat Sep 01 07:20:29 2018 +0000

description:
Wait in detach if the discovery thread is still running. Avoids crashes
when a device is attached/detached rapidly.

diffstat:

 sys/dev/scsipi/scsiconf.c   |  14 +++++++++++---
 sys/dev/scsipi/scsipiconf.h |   3 ++-
 2 files changed, 13 insertions(+), 4 deletions(-)

diffs (73 lines):

diff -r 39a363070a98 -r a82db9aec88c sys/dev/scsipi/scsiconf.c
--- a/sys/dev/scsipi/scsiconf.c Sat Sep 01 07:19:19 2018 +0000
+++ b/sys/dev/scsipi/scsiconf.c Sat Sep 01 07:20:29 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: scsiconf.c,v 1.280 2017/06/17 22:35:50 mlelstv Exp $   */
+/*     $NetBSD: scsiconf.c,v 1.281 2018/09/01 07:20:29 mlelstv Exp $   */
 
 /*-
  * Copyright (c) 1998, 1999, 2004 The NetBSD Foundation, Inc.
@@ -48,7 +48,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: scsiconf.c,v 1.280 2017/06/17 22:35:50 mlelstv Exp $");
+__KERNEL_RCSID(0, "$NetBSD: scsiconf.c,v 1.281 2018/09/01 07:20:29 mlelstv Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -270,7 +270,7 @@
          * Create the discover thread
          */
         if (kthread_create(PRI_NONE, 0, NULL, scsibus_discover_thread, sc,
-            NULL, "%s-d", chan->chan_name)) {
+            &chan->chan_dthread, "%s-d", chan->chan_name)) {
                 aprint_error_dev(sc->sc_dev, "unable to create discovery "
                    "thread for channel %d\n", chan->chan_channel);
                 return;
@@ -283,6 +283,7 @@
        struct scsibus_softc *sc = arg;
 
        scsibus_config(sc);
+       sc->sc_channel->chan_dthread = NULL;
        kthread_exit(0);
 }
 
@@ -336,6 +337,12 @@
        int error;
 
        /*
+        * Defer while discovery thread is running
+        */
+       while (chan->chan_dthread != NULL)
+               kpause("scsibusdet", false, hz, NULL);
+
+       /*
         * Detach all of the periphs.
         */
        error = scsipi_target_detach(chan, -1, -1, flags);
@@ -415,6 +422,7 @@
                 */
                scsipi_set_xfer_mode(chan, target, 1);
        }
+
        scsipi_adapter_delref(chan->chan_adapter);
 ret:
        return (error);
diff -r 39a363070a98 -r a82db9aec88c sys/dev/scsipi/scsipiconf.h
--- a/sys/dev/scsipi/scsipiconf.h       Sat Sep 01 07:19:19 2018 +0000
+++ b/sys/dev/scsipi/scsipiconf.h       Sat Sep 01 07:20:29 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: scsipiconf.h,v 1.127 2018/07/04 03:17:01 kamil Exp $   */
+/*     $NetBSD: scsipiconf.h,v 1.128 2018/09/01 07:20:29 mlelstv Exp $ */
 
 /*-
  * Copyright (c) 1998, 1999, 2000, 2004 The NetBSD Foundation, Inc.
@@ -289,6 +289,7 @@
 
        int     chan_defquirks;         /* default device's quirks */
 
+       struct lwp *chan_dthread;       /* discovery thread */
        struct lwp *chan_thread;        /* completion thread */
        int     chan_tflags;            /* flags for the completion thread */