svn commit: r306841 - head/sys/kern

[Mateusz Guzik]

Author: mjg
Date: Sat Oct  8 13:36:59 2016
New Revision: 306841
URL: https://svnweb.freebsd.org/changeset/base/306841

Log:
  vfs: clear the tmp free list flag before taking the free vnode list lock
  
  Safe access is already guaranteed because of the mnt_listmx lock.

Modified:
  head/sys/kern/vfs_subr.c

Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c	Sat Oct  8 12:53:23 2016	(r306840)
+++ head/sys/kern/vfs_subr.c	Sat Oct  8 13:36:59 2016	(r306841)
@@ -1066,16 +1066,16 @@ vnlru_return_batch_locked(struct mount *
 	if (mp->mnt_tmpfreevnodelistsize == 0)
 		return;
 
-	mtx_lock(&vnode_free_list_mtx);
 	TAILQ_FOREACH(vp, &mp->mnt_tmpfreevnodelist, v_actfreelist) {
 		VNASSERT((vp->v_mflag & VMP_TMPMNTFREELIST) != 0, vp,
 		    ("vnode without VMP_TMPMNTFREELIST on mnt_tmpfreevnodelist"));
 		vp->v_mflag &= ~VMP_TMPMNTFREELIST;
 	}
+	mtx_lock(&vnode_free_list_mtx);
 	TAILQ_CONCAT(&vnode_free_list, &mp->mnt_tmpfreevnodelist, v_actfreelist);
 	freevnodes += mp->mnt_tmpfreevnodelistsize;
-	mp->mnt_tmpfreevnodelistsize = 0;
 	mtx_unlock(&vnode_free_list_mtx);
+	mp->mnt_tmpfreevnodelistsize = 0;
 }
 
 static void