svn commit: r351471 - in head/sys: kern sys

[Mateusz Guzik]

Author: mjg
Date: Sun Aug 25 05:11:43 2019
New Revision: 351471
URL: https://svnweb.freebsd.org/changeset/base/351471

Log:
  vfs: add vholdnz (for already held vnodes)
  
  Reviewed by:	kib (previous version)
  Sponsored by:	The FreeBSD Foundation
  Differential Revision:	https://reviews.freebsd.org/D21358

Modified:
  head/sys/kern/vfs_subr.c
  head/sys/sys/vnode.h

Modified: head/sys/kern/vfs_subr.c
==============================================================================
--- head/sys/kern/vfs_subr.c	Sun Aug 25 04:56:33 2019	(r351470)
+++ head/sys/kern/vfs_subr.c	Sun Aug 25 05:11:43 2019	(r351471)
@@ -3018,6 +3018,19 @@ _vhold(struct vnode *vp, bool locked)
 		VI_UNLOCK(vp);
 }
 
+void
+vholdnz(struct vnode *vp)
+{
+
+	CTR2(KTR_VFS, "%s: vp %p", __func__, vp);
+#ifdef INVARIANTS
+	int old = atomic_fetchadd_int(&vp->v_holdcnt, 1);
+	VNASSERT(old > 0, vp, ("%s: wrong hold count", __func__));
+#else
+	atomic_add_int(&vp->v_holdcnt, 1);
+#endif
+}
+
 /*
  * Drop the hold count of the vnode.  If this is the last reference to
  * the vnode we place it on the free list unless it has been vgone'd

Modified: head/sys/sys/vnode.h
==============================================================================
--- head/sys/sys/vnode.h	Sun Aug 25 04:56:33 2019	(r351470)
+++ head/sys/sys/vnode.h	Sun Aug 25 05:11:43 2019	(r351471)
@@ -657,6 +657,7 @@ void	vgone(struct vnode *vp);
 #define	vhold(vp)	_vhold((vp), 0)
 #define	vholdl(vp)	_vhold((vp), 1)
 void	_vhold(struct vnode *, bool);
+void	vholdnz(struct vnode *);
 void	vinactive(struct vnode *, struct thread *);
 int	vinvalbuf(struct vnode *vp, int save, int slpflag, int slptimeo);
 int	vtruncbuf(struct vnode *vp, off_t length, int blksize);