Make insmntque() externally visibile and allow it to fail (e.g. during

late stages of unmount).  On failure, the vnode is recycled.

Add insmntque1(), to allow for file system specific cleanup when
recycling vnode on failure.

Change getnewvnode() to no longer call insmntque().  Previously,
embryonic vnodes were put onto the list of vnode belonging to a file
system, which is unsafe for a file system marked MPSAFE.

Change vfs_hash_insert() to no longer lock the vnode.  The caller now
has that responsibility.

Change most file systems to lock the vnode and call insmntque() or
insmntque1() after a new vnode has been sufficiently setup.  Handle
failed insmntque*() calls by propagating errors to callers, possibly
after some file system specific cleanup.

Approved by:	re (kensmith)
Reviewed by:	kib
In collaboration with:	kib

1 files changed, 15 insertions, 0 deletions

diff --git a/sys/fs/nullfs/null_subr.c b/sys/fs/nullfs/null_subr.c
index 5dc7c63..66144c0 100644
--- a/sys/fs/nullfs/null_subr.c
+++ b/sys/fs/nullfs/null_subr.c
@@ -185,6 +185,18 @@ null_hashins(mp, xp)
 	return (NULLVP);
 }
 
+static void
+null_insmntque_dtr(struct vnode *vp, void *xp)
+{
+	vp->v_data = NULL;
+	vp->v_vnlock = &vp->v_lock;
+	FREE(xp, M_NULLFSNODE);
+	vp->v_op = &dead_vnodeops;
+	(void) vn_lock(vp, LK_EXCLUSIVE | LK_RETRY, curthread);
+	vgone(vp);
+	vput(vp);
+}
+
 /*
  * Make a new or get existing nullfs node.
  * Vp is the alias vnode, lowervp is the lower vnode.
@@ -239,6 +251,9 @@ null_nodeget(mp, lowervp, vpp)
 	vp->v_vnlock = lowervp->v_vnlock;
 	if (vp->v_vnlock == NULL)
 		panic("null_nodeget: Passed a NULL vnlock.\n");
+	error = insmntque1(vp, mp, null_insmntque_dtr, xp);
+	if (error != 0)
+		return (error);
 	/*
 	 * Atomically insert our new node into the hash or vget existing 
 	 * if someone else has beaten us to it.