KASSERT() for VOP_*

[Martin Pieuchot]

This is mostly the same diff that has been backed out months ago with
the VOP_CLOSE() case fixed.  VOP_CLOSE() can accept a NULL argument
instead of `curproc' when garbage collecting passed FDs.

The intent is to stop passing a "struct proc *" when a function applies
only to `curproc'.  Synchronization/locking primitives are obviously
different if a CPU can modify the fields of any thread or only of the
current one.

Index: kern/vfs_vops.c
===================================================================
RCS file: /cvs/src/sys/kern/vfs_vops.c,v
retrieving revision 1.28
diff -u -p -r1.28 vfs_vops.c
--- kern/vfs_vops.c     8 Apr 2020 08:07:51 -0000       1.28
+++ kern/vfs_vops.c     27 Apr 2020 08:10:02 -0000
@@ -145,6 +145,8 @@ VOP_OPEN(struct vnode *vp, int mode, str
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == curproc);
+
        if (vp->v_op->vop_open == NULL)
                return (EOPNOTSUPP);
 
@@ -164,6 +166,7 @@ VOP_CLOSE(struct vnode *vp, int fflag, s
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == NULL || p == curproc);
        ASSERT_VP_ISLOCKED(vp);
 
        if (vp->v_op->vop_close == NULL)
@@ -184,6 +187,7 @@ VOP_ACCESS(struct vnode *vp, int mode, s
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        ASSERT_VP_ISLOCKED(vp);
 
        if (vp->v_op->vop_access == NULL)
@@ -202,6 +206,7 @@ VOP_GETATTR(struct vnode *vp, struct vat
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        if (vp->v_op->vop_getattr == NULL)
                return (EOPNOTSUPP);
 
@@ -219,6 +224,7 @@ VOP_SETATTR(struct vnode *vp, struct vat
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        ASSERT_VP_ISLOCKED(vp);
 
        if (vp->v_op->vop_setattr == NULL)
@@ -282,6 +288,7 @@ VOP_IOCTL(struct vnode *vp, u_long comma
        a.a_cred = cred;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        if (vp->v_op->vop_ioctl == NULL)
                return (EOPNOTSUPP);
 
@@ -300,6 +307,7 @@ VOP_POLL(struct vnode *vp, int fflag, in
        a.a_events = events;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        if (vp->v_op->vop_poll == NULL)
                return (EOPNOTSUPP);
 
@@ -344,6 +352,7 @@ VOP_FSYNC(struct vnode *vp, struct ucred
        a.a_waitfor = waitfor;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        ASSERT_VP_ISLOCKED(vp);
 
        if (vp->v_op->vop_fsync == NULL)
@@ -565,6 +574,7 @@ VOP_INACTIVE(struct vnode *vp, struct pr
        a.a_vp = vp;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        ASSERT_VP_ISLOCKED(vp);
 
        if (vp->v_op->vop_inactive == NULL)
@@ -581,6 +591,7 @@ VOP_RECLAIM(struct vnode *vp, struct pro
        a.a_vp = vp;
        a.a_p = p;
 
+       KASSERT(p == curproc);
        if (vp->v_op->vop_reclaim == NULL)
                return (EOPNOTSUPP);