[src/prg-localcount2]: src/sys/kern Release the interlock mutex before callin...

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

details:   https://anonhg.NetBSD.org/src/rev/f7bd4b7fa4a8
branches:  prg-localcount2
changeset: 823529:f7bd4b7fa4a8
user:      pgoyette <pgoyette%NetBSD.org@localhost>
date:      Sun Apr 30 05:18:53 2017 +0000

description:
Release the interlock mutex before calling device_release().

Ensure that device_release() gets called even if the (ca->ca_detach)()
call fails.

diffstat:

 sys/kern/subr_autoconf.c |  12 +++++++++---
 1 files changed, 9 insertions(+), 3 deletions(-)

diffs (42 lines):

diff -r ca5f4c0c0986 -r f7bd4b7fa4a8 sys/kern/subr_autoconf.c
--- a/sys/kern/subr_autoconf.c  Sun Apr 30 05:16:52 2017 +0000
+++ b/sys/kern/subr_autoconf.c  Sun Apr 30 05:18:53 2017 +0000
@@ -1,4 +1,4 @@
-/* $NetBSD: subr_autoconf.c,v 1.252.4.2 2017/04/28 06:00:33 pgoyette Exp $ */
+/* $NetBSD: subr_autoconf.c,v 1.252.4.3 2017/04/30 05:18:53 pgoyette Exp $ */
 
 /*
  * Copyright (c) 1996, 2000 Christopher G. Demetriou
@@ -77,7 +77,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.252.4.2 2017/04/28 06:00:33 pgoyette Exp $");
+__KERNEL_RCSID(0, "$NetBSD: subr_autoconf.c,v 1.252.4.3 2017/04/30 05:18:53 pgoyette Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_ddb.h"
@@ -1277,9 +1277,13 @@
 
        /*
         * Release the reference that was held by (the caller of)
-        * config_detach_release()
+        * config_detach_release().  Note that since device_release()
+        * might need to acquire the alldevs.lock mutex, we need to
+        * release and then reacquire the mutex.
         */
+       mutex_exit(&alldevs.lock);
        device_release(dev);
+       mutex_enter(&alldevs.lock);
 
        /* Now wait for references to drain - no new refs are possible */
        localcount_drain(&dev->dv_localcnt, &config_drain_cv,
@@ -1866,6 +1870,8 @@
                }
        }
        config_alldevs_exit(&af);
+       if (rv != 0)
+               device_release(dev);
 
        return rv;
 }