[src/trunk]: src/sys driver(9): Make vdevgone call config_detach_commit if ap...

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

details:   https://anonhg.NetBSD.org/src/rev/9df7a090e68a
branches:  trunk
changeset: 364524:9df7a090e68a
user:      riastradh <riastradh%NetBSD.org@localhost>
date:      Mon Mar 28 12:38:33 2022 +0000

description:
driver(9): Make vdevgone call config_detach_commit if appropriate.

Make sure to do this before spec_node_lookup_by_dev -- that might wait
for a concurrent revoke to complete, which in turn might wait for a
concurrent open to complete, which in turn might be waiting for the
device to commit to detaching.

diffstat:

 sys/kern/subr_devsw.c |  40 ++++++++++++++++++++++++++++++++++++++--
 sys/kern/vfs_subr.c   |  18 ++++++++++++++++--
 sys/sys/conf.h        |   6 +++++-
 3 files changed, 59 insertions(+), 5 deletions(-)

diffs (134 lines):

diff -r 6bf79b298bcc -r 9df7a090e68a sys/kern/subr_devsw.c
--- a/sys/kern/subr_devsw.c     Mon Mar 28 12:38:24 2022 +0000
+++ b/sys/kern/subr_devsw.c     Mon Mar 28 12:38:33 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: subr_devsw.c,v 1.42 2022/03/28 12:34:08 riastradh Exp $        */
+/*     $NetBSD: subr_devsw.c,v 1.43 2022/03/28 12:38:33 riastradh Exp $        */
 
 /*-
  * Copyright (c) 2001, 2002, 2007, 2008 The NetBSD Foundation, Inc.
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.42 2022/03/28 12:34:08 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_devsw.c,v 1.43 2022/03/28 12:38:33 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_dtrace.h"
@@ -1068,6 +1068,24 @@
        return rv;
 }
 
+void
+bdev_detached(dev_t dev)
+{
+       const struct bdevsw *d;
+       device_t dv;
+       int unit;
+
+       if ((d = bdevsw_lookup(dev)) == NULL)
+               return;
+       if (d->d_devtounit == NULL)
+               return;
+       if ((unit = (*d->d_devtounit)(dev)) == -1)
+               return;
+       if ((dv = device_lookup(d->d_cfdriver, unit)) == NULL)
+               return;
+       config_detach_commit(dv);
+}
+
 int
 cdev_open(dev_t dev, int flag, int devtype, lwp_t *l)
 {
@@ -1288,6 +1306,24 @@
        return d->d_flag & D_TYPEMASK;
 }
 
+void
+cdev_detached(dev_t dev)
+{
+       const struct cdevsw *d;
+       device_t dv;
+       int unit;
+
+       if ((d = cdevsw_lookup(dev)) == NULL)
+               return;
+       if (d->d_devtounit == NULL)
+               return;
+       if ((unit = (*d->d_devtounit)(dev)) == -1)
+               return;
+       if ((dv = device_lookup(d->d_cfdriver, unit)) == NULL)
+               return;
+       config_detach_commit(dv);
+}
+
 /*
  * nommap(dev, off, prot)
  *
diff -r 6bf79b298bcc -r 9df7a090e68a sys/kern/vfs_subr.c
--- a/sys/kern/vfs_subr.c       Mon Mar 28 12:38:24 2022 +0000
+++ b/sys/kern/vfs_subr.c       Mon Mar 28 12:38:33 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: vfs_subr.c,v 1.492 2022/03/28 12:37:46 riastradh Exp $ */
+/*     $NetBSD: vfs_subr.c,v 1.493 2022/03/28 12:38:33 riastradh Exp $ */
 
 /*-
  * Copyright (c) 1997, 1998, 2004, 2005, 2007, 2008, 2019, 2020
@@ -69,7 +69,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.492 2022/03/28 12:37:46 riastradh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_subr.c,v 1.493 2022/03/28 12:38:33 riastradh Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -512,6 +512,20 @@
        for (mn = minl; mn <= minh; mn++) {
                dev = makedev(maj, mn);
                /*
+                * Notify anyone trying to get at this device that it
+                * has been detached, and then revoke it.
+                */
+               switch (type) {
+               case VBLK:
+                       bdev_detached(dev);
+                       break;
+               case VCHR:
+                       cdev_detached(dev);
+                       break;
+               default:
+                       panic("invalid specnode type: %d", type);
+               }
+               /*
                 * Passing 0 as flags, instead of VDEAD_NOWAIT, means
                 * spec_node_lookup_by_dev will wait for vnodes it
                 * finds concurrently being revoked before returning.
diff -r 6bf79b298bcc -r 9df7a090e68a sys/sys/conf.h
--- a/sys/sys/conf.h    Mon Mar 28 12:38:24 2022 +0000
+++ b/sys/sys/conf.h    Mon Mar 28 12:38:33 2022 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: conf.h,v 1.158 2022/03/28 12:34:17 riastradh Exp $     */
+/*     $NetBSD: conf.h,v 1.159 2022/03/28 12:38:33 riastradh Exp $     */
 
 /*-
  * Copyright (c) 1990, 1993
@@ -172,6 +172,8 @@
 dev_type_size(bdev_size);
 dev_type_discard(bdev_discard);
 
+void   bdev_detached(dev_t);
+
 dev_type_open(cdev_open);
 dev_type_close(cdev_close);
 dev_type_read(cdev_read);
@@ -184,6 +186,8 @@
 dev_type_kqfilter(cdev_kqfilter);
 dev_type_discard(cdev_discard);
 
+void   cdev_detached(dev_t);
+
 int    cdev_type(dev_t);
 int    cdev_flags(dev_t);
 int    bdev_type(dev_t);