svn commit: r190942 - head/sys/kern

[Konstantin Belousov]

Author: kib
Date: Sat Apr 11 16:12:20 2009
New Revision: 190942
URL: http://svn.freebsd.org/changeset/base/190942

Log:
  When zapping v_cache_dd for !MAKEENTRY case in cache_lookup(), we shall
  lock cache as writer.
  
  Reviewed by:	kan

Modified:
  head/sys/kern/vfs_cache.c

Modified: head/sys/kern/vfs_cache.c
==============================================================================
--- head/sys/kern/vfs_cache.c	Sat Apr 11 15:26:31 2009	(r190941)
+++ head/sys/kern/vfs_cache.c	Sat Apr 11 16:12:20 2009	(r190942)
@@ -410,6 +410,8 @@ retry_wlocked:
 				goto unlock;
 			}
 			if ((cnp->cn_flags & MAKEENTRY) == 0) {
+				if (!wlocked && !CACHE_UPGRADE_LOCK())
+					goto wlock;
 				if (dvp->v_cache_dd->nc_flag & NCF_ISDOTDOT)
 					cache_zap(dvp->v_cache_dd);
 				dvp->v_cache_dd = NULL;