From: Matthew Dillon <dillon@apollo.backplane.com>
Date: Thu, 18 Nov 2010 17:20:23 +0000 (-0800)
Subject: kernel - Fix global counter used in lockf assertions
X-Git-Url: http://gitweb.dragonflybsd.org/dragonfly.git/commitdiff_plain/20b10249803190a9d3299b2e6f2a71c4fe2918e4

kernel - Fix global counter used in lockf assertions

* lockf elements can be accessed MP.

* This may fix the 'panic: assertion: lf_global_counter>=0 in lf_destroy_range'
  panic.

Reported-by: Peter Avalos <peter@theshell.com>
---

diff --git a/sys/kern/kern_lockf.c b/sys/kern/kern_lockf.c
index f660b20..33cecf0 100644
--- a/sys/kern/kern_lockf.c
+++ b/sys/kern/kern_lockf.c
@@ -812,7 +812,7 @@ lf_alloc_range(void)
 	struct lockf_range *range;
 
 #ifdef INVARIANTS
-	lf_global_counter++;
+	atomic_add_int(&lf_global_counter, 1);
 #endif
 	range = kmalloc(sizeof(struct lockf_range), M_LOCKF, M_WAITOK);
 	range->lf_owner = NULL;
@@ -853,8 +853,8 @@ lf_destroy_range(struct lockf_range *range)
 		  range->lf_start, range->lf_end);
 	kfree(range, M_LOCKF);
 #ifdef INVARIANTS
-	lf_global_counter--;
-	KKASSERT(lf_global_counter>=0);
+	atomic_add_int(&lf_global_counter, -1);
+	KKASSERT(lf_global_counter >= 0);
 #endif
 }