svn commit: r205886 - head/sys/kern

[John Baldwin]

Author: jhb
Date: Tue Mar 30 18:31:55 2010
New Revision: 205886
URL: http://svn.freebsd.org/changeset/base/205886

Log:
  Defer freeing a kevent list until after dropping kqueue locks.
  
  LOR:		185
  Submitted by:	Matthew Fleming @ Isilon
  MFC after:	1 week

Modified:
  head/sys/kern/kern_event.c

Modified: head/sys/kern/kern_event.c
==============================================================================
--- head/sys/kern/kern_event.c	Tue Mar 30 18:29:19 2010	(r205885)
+++ head/sys/kern/kern_event.c	Tue Mar 30 18:31:55 2010	(r205886)
@@ -1218,7 +1218,7 @@ static int
 kqueue_expand(struct kqueue *kq, struct filterops *fops, uintptr_t ident,
 	int waitok)
 {
-	struct klist *list, *tmp_knhash;
+	struct klist *list, *tmp_knhash, *to_free;
 	u_long tmp_knhashmask;
 	int size;
 	int fd;
@@ -1226,6 +1226,7 @@ kqueue_expand(struct kqueue *kq, struct 
 
 	KQ_NOTOWNED(kq);
 
+	to_free = NULL;
 	if (fops->f_isfd) {
 		fd = ident;
 		if (kq->kq_knlistsize <= fd) {
@@ -1237,13 +1238,13 @@ kqueue_expand(struct kqueue *kq, struct 
 				return ENOMEM;
 			KQ_LOCK(kq);
 			if (kq->kq_knlistsize > fd) {
-				free(list, M_KQUEUE);
+				to_free = list;
 				list = NULL;
 			} else {
 				if (kq->kq_knlist != NULL) {
 					bcopy(kq->kq_knlist, list,
 					    kq->kq_knlistsize * sizeof(*list));
-					free(kq->kq_knlist, M_KQUEUE);
+					to_free = kq->kq_knlist;
 					kq->kq_knlist = NULL;
 				}
 				bzero((caddr_t)list +
@@ -1265,11 +1266,12 @@ kqueue_expand(struct kqueue *kq, struct 
 				kq->kq_knhash = tmp_knhash;
 				kq->kq_knhashmask = tmp_knhashmask;
 			} else {
-				free(tmp_knhash, M_KQUEUE);
+				to_free = tmp_knhash;
 			}
 			KQ_UNLOCK(kq);
 		}
 	}
+	free(to_free, M_KQUEUE);
 
 	KQ_NOTOWNED(kq);
 	return 0;