Regularize the vop_stdlock'ing protocol across all the filesystems

that use it. Specifically, vop_stdlock uses the lock pointed to by
vp->v_vnlock. By default, getnewvnode sets up vp->v_vnlock to
reference vp->v_lock. Filesystems that wish to use the default
do not need to allocate a lock at the front of their node structure
(as some still did) or do a lockinit. They can simply start using
vn_lock/VOP_UNLOCK. Filesystems that wish to manage their own locks,
but still use the vop_stdlock functions (such as nullfs) can simply
replace vp->v_vnlock with a pointer to the lock that they wish to
have used for the vnode. Such filesystems are responsible for
setting the vp->v_vnlock back to the default in their vop_reclaim
routine (e.g., vp->v_vnlock = &vp->v_lock).

In theory, this set of changes cleans up the existing filesystem
lock interface and should have no function change to the existing
locking scheme.

Sponsored by:	DARPA & NAI Labs.

1 files changed, 0 insertions, 3 deletions

diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index 1fdd210..f2a43e0 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -226,9 +226,6 @@ null_nodeget(mp, lowervp, vpp)
 	vp->v_type = lowervp->v_type;
 	vp->v_data = xp;
 
-	/* Though v_lock is inited by getnewvnode(), we want our own wmesg */
-	lockinit(&vp->v_lock, PVFS, "nunode", VLKTIMEOUT, LK_NOPAUSE);
-
 	/*
 	 * From NetBSD:
 	 * Now lock the new node. We rely on the fact that we were passed