2 * Copyright (c) 1992, 1993
3 * The Regents of the University of California. All rights reserved.
5 * This code is derived from software contributed to Berkeley by
6 * John Heidemann of the UCLA Ficus project.
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
11 * 1. Redistributions of source code must retain the above copyright
12 * notice, this list of conditions and the following disclaimer.
13 * 2. Redistributions in binary form must reproduce the above copyright
14 * notice, this list of conditions and the following disclaimer in the
15 * documentation and/or other materials provided with the distribution.
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17 * must display the following acknowledgement:
18 * This product includes software developed by the University of
19 * California, Berkeley and its contributors.
20 * 4. Neither the name of the University nor the names of its contributors
21 * may be used to endorse or promote products derived from this software
22 * without specific prior written permission.
24 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
25 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
26 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
27 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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29 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
30 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
31 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
32 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
33 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
36 * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95
39 * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92
40 * $FreeBSD: src/sys/miscfs/nullfs/null_vnops.c,v 1.38.2.6 2002/07/31 00:32:28 semenu Exp $
42 * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project
44 * $FreeBSD: src/sys/miscfs/nullfs/null_vnops.c,v 1.38.2.6 2002/07/31 00:32:28 semenu Exp $
50 * (See mount_null(8) for more information.)
52 * The null layer duplicates a portion of the file system
53 * name space under a new name. In this respect, it is
54 * similar to the loopback file system. It differs from
55 * the loopback fs in two respects: it is implemented using
56 * a stackable layers techniques, and its "null-node"s stack above
57 * all lower-layer vnodes, not just over directory vnodes.
59 * The null layer has two purposes. First, it serves as a demonstration
60 * of layering by proving a layer which does nothing. (It actually
61 * does everything the loopback file system does, which is slightly
62 * more than nothing.) Second, the null layer can serve as a prototype
63 * layer. Since it provides all necessary layer framework,
64 * new file system layers can be created very easily be starting
67 * The remainder of this man page examines the null layer as a basis
68 * for constructing new layers.
71 * INSTANTIATING NEW NULL LAYERS
73 * New null layers are created with mount_null(8).
74 * Mount_null(8) takes two arguments, the pathname
75 * of the lower vfs (target-pn) and the pathname where the null
76 * layer will appear in the namespace (alias-pn). After
77 * the null layer is put into place, the contents
78 * of target-pn subtree will be aliased under alias-pn.
81 * OPERATION OF A NULL LAYER
83 * The null layer is the minimum file system layer,
84 * simply bypassing all possible operations to the lower layer
85 * for processing there. The majority of its activity centers
86 * on the bypass routine, through which nearly all vnode operations
89 * The bypass routine accepts arbitrary vnode operations for
90 * handling by the lower layer. It begins by examing vnode
91 * operation arguments and replacing any null-nodes by their
92 * lower-layer equivlants. It then invokes the operation
93 * on the lower layer. Finally, it replaces the null-nodes
94 * in the arguments and, if a vnode is return by the operation,
95 * stacks a null-node on top of the returned vnode.
97 * Although bypass handles most operations, vop_getattr, vop_lock,
98 * vop_unlock, vop_inactive, vop_reclaim, and vop_print are not
99 * bypassed. Vop_getattr must change the fsid being returned.
100 * Vop_lock and vop_unlock must handle any locking for the
101 * current vnode as well as pass the lock request down.
102 * Vop_inactive and vop_reclaim are not bypassed so that
103 * they can handle freeing null-layer specific data. Vop_print
104 * is not bypassed to avoid excessive debugging information.
105 * Also, certain vnode operations change the locking state within
106 * the operation (create, mknod, remove, link, rename, mkdir, rmdir,
107 * and symlink). Ideally these operations should not change the
108 * lock state, but should be changed to let the caller of the
109 * function unlock them. Otherwise all intermediate vnode layers
110 * (such as union, umapfs, etc) must catch these functions to do
111 * the necessary locking at their layer.
114 * INSTANTIATING VNODE STACKS
116 * Mounting associates the null layer with a lower layer,
117 * effect stacking two VFSes. Vnode stacks are instead
118 * created on demand as files are accessed.
120 * The initial mount creates a single vnode stack for the
121 * root of the new null layer. All other vnode stacks
122 * are created as a result of vnode operations on
123 * this or other null vnode stacks.
125 * New vnode stacks come into existance as a result of
126 * an operation which returns a vnode.
127 * The bypass routine stacks a null-node above the new
128 * vnode before returning it to the caller.
130 * For example, imagine mounting a null layer with
131 * "mount_null /usr/include /dev/layer/null".
132 * Changing directory to /dev/layer/null will assign
133 * the root null-node (which was created when the null layer was mounted).
134 * Now consider opening "sys". A vop_lookup would be
135 * done on the root null-node. This operation would bypass through
136 * to the lower layer which would return a vnode representing
137 * the UFS "sys". Null_bypass then builds a null-node
138 * aliasing the UFS "sys" and returns this to the caller.
139 * Later operations on the null-node "sys" will repeat this
140 * process when constructing other vnode stacks.
143 * CREATING OTHER FILE SYSTEM LAYERS
145 * One of the easiest ways to construct new file system layers is to make
146 * a copy of the null layer, rename all files and variables, and
147 * then begin modifing the copy. Sed can be used to easily rename
150 * The umap layer is an example of a layer descended from the
154 * INVOKING OPERATIONS ON LOWER LAYERS
156 * There are two techniques to invoke operations on a lower layer
157 * when the operation cannot be completely bypassed. Each method
158 * is appropriate in different situations. In both cases,
159 * it is the responsibility of the aliasing layer to make
160 * the operation arguments "correct" for the lower layer
161 * by mapping an vnode arguments to the lower layer.
163 * The first approach is to call the aliasing layer's bypass routine.
164 * This method is most suitable when you wish to invoke the operation
165 * currently being handled on the lower layer. It has the advantage
166 * that the bypass routine already must do argument mapping.
167 * An example of this is null_getattrs in the null layer.
169 * A second approach is to directly invoke vnode operations on
170 * the lower layer with the VOP_OPERATIONNAME interface.
171 * The advantage of this method is that it is easy to invoke
172 * arbitrary operations on the lower layer. The disadvantage
173 * is that vnode arguments must be manualy mapped.
177 #include <sys/param.h>
178 #include <sys/systm.h>
179 #include <sys/kernel.h>
180 #include <sys/sysctl.h>
181 #include <sys/vnode.h>
182 #include <sys/mount.h>
183 #include <sys/namei.h>
184 #include <sys/malloc.h>
186 #include <miscfs/nullfs/null.h>
188 static int null_bug_bypass = 0; /* for debugging: enables bypass printf'ing */
189 SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW,
190 &null_bug_bypass, 0, "");
192 static int null_access(struct vop_access_args *ap);
193 static int null_createvobject(struct vop_createvobject_args *ap);
194 static int null_destroyvobject(struct vop_destroyvobject_args *ap);
195 static int null_getattr(struct vop_getattr_args *ap);
196 static int null_getvobject(struct vop_getvobject_args *ap);
197 static int null_inactive(struct vop_inactive_args *ap);
198 static int null_islocked(struct vop_islocked_args *ap);
199 static int null_lock(struct vop_lock_args *ap);
200 static int null_lookup(struct vop_lookup_args *ap);
201 static int null_open(struct vop_open_args *ap);
202 static int null_print(struct vop_print_args *ap);
203 static int null_reclaim(struct vop_reclaim_args *ap);
204 static int null_rename(struct vop_rename_args *ap);
205 static int null_setattr(struct vop_setattr_args *ap);
206 static int null_unlock(struct vop_unlock_args *ap);
209 * This is the 10-Apr-92 bypass routine.
210 * This version has been optimized for speed, throwing away some
211 * safety checks. It should still always work, but it's not as
212 * robust to programmer errors.
214 * In general, we map all vnodes going down and unmap them on the way back.
215 * As an exception to this, vnodes can be marked "unmapped" by setting
216 * the Nth bit in operation's vdesc_flags.
218 * Also, some BSD vnode operations have the side effect of vrele'ing
219 * their arguments. With stacking, the reference counts are held
220 * by the upper node, not the lower one, so we must handle these
221 * side-effects here. This is not of concern in Sun-derived systems
222 * since there are no such side-effects.
224 * This makes the following assumptions:
225 * - only one returned vpp
226 * - no INOUT vpp's (Sun's vop_open has one of these)
227 * - the vnode operation vector of the first vnode should be used
228 * to determine what implementation of the op should be invoked
229 * - all mapped vnodes are of our vnode-type (NEEDSWORK:
230 * problems on rmdir'ing mount points and renaming?)
234 struct vop_generic_args /* {
235 struct vnodeop_desc *a_desc;
236 <other random data follows, presumably>
239 register struct vnode **this_vp_p;
241 struct vnode *old_vps[VDESC_MAX_VPS];
242 struct vnode **vps_p[VDESC_MAX_VPS];
243 struct vnode ***vppp;
244 struct vnodeop_desc *descp = ap->a_desc;
248 printf ("null_bypass: %s\n", descp->vdesc_name);
252 * We require at least one vp.
254 if (descp->vdesc_vp_offsets == NULL ||
255 descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
256 panic ("null_bypass: no vp's in map");
260 * Map the vnodes going in.
261 * Later, we'll invoke the operation based on
262 * the first mapped vnode's operation vector.
264 reles = descp->vdesc_flags;
265 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
266 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
267 break; /* bail out at end of list */
268 vps_p[i] = this_vp_p =
269 VOPARG_OFFSETTO(struct vnode**,descp->vdesc_vp_offsets[i],ap);
271 * We're not guaranteed that any but the first vnode
272 * are of our type. Check for and don't map any
273 * that aren't. (We must always map first vp or vclean fails.)
275 if (i && (*this_vp_p == NULLVP ||
276 (*this_vp_p)->v_op != null_vnodeop_p)) {
279 old_vps[i] = *this_vp_p;
280 *(vps_p[i]) = NULLVPTOLOWERVP(*this_vp_p);
282 * XXX - Several operations have the side effect
283 * of vrele'ing their vp's. We must account for
284 * that. (This should go away in the future.)
286 if (reles & VDESC_VP0_WILLRELE)
293 * Call the operation on the lower layer
294 * with the modified argument structure.
296 if (vps_p[0] && *vps_p[0])
297 error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
299 printf("null_bypass: no map for %s\n", descp->vdesc_name);
304 * Maintain the illusion of call-by-value
305 * by restoring vnodes in the argument structure
306 * to their original value.
308 reles = descp->vdesc_flags;
309 for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
310 if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
311 break; /* bail out at end of list */
313 *(vps_p[i]) = old_vps[i];
315 if (reles & VDESC_VP0_WILLUNLOCK)
316 VOP_UNLOCK(*(vps_p[i]), LK_THISLAYER, curproc);
318 if (reles & VDESC_VP0_WILLRELE)
324 * Map the possible out-going vpp
325 * (Assumes that the lower layer always returns
326 * a VREF'ed vpp unless it gets an error.)
328 if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
329 !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
332 * XXX - even though some ops have vpp returned vp's,
333 * several ops actually vrele this before returning.
334 * We must avoid these ops.
335 * (This should go away when these ops are regularized.)
337 if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
339 vppp = VOPARG_OFFSETTO(struct vnode***,
340 descp->vdesc_vpp_offset,ap);
342 error = null_node_create(old_vps[0]->v_mount, **vppp, *vppp);
350 * We have to carry on the locking protocol on the null layer vnodes
351 * as we progress through the tree. We also have to enforce read-only
352 * if this layer is mounted read-only.
356 struct vop_lookup_args /* {
357 struct vnode * a_dvp;
358 struct vnode ** a_vpp;
359 struct componentname * a_cnp;
362 struct componentname *cnp = ap->a_cnp;
363 struct vnode *dvp = ap->a_dvp;
364 struct proc *p = cnp->cn_proc;
365 int flags = cnp->cn_flags;
366 struct vnode *vp, *ldvp, *lvp;
369 if ((flags & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
370 (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
373 * Although it is possible to call null_bypass(), we'll do
374 * a direct call to reduce overhead
376 ldvp = NULLVPTOLOWERVP(dvp);
378 error = VOP_LOOKUP(ldvp, &lvp, cnp);
379 if (error == EJUSTRETURN && (flags & ISLASTCN) &&
380 (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
381 (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME))
385 * Rely only on the PDIRUNLOCK flag which should be carefully
386 * tracked by underlying filesystem.
388 if (cnp->cn_flags & PDIRUNLOCK)
389 VOP_UNLOCK(dvp, LK_THISLAYER, p);
390 if ((error == 0 || error == EJUSTRETURN) && lvp != NULL) {
396 error = null_node_create(dvp->v_mount, lvp, &vp);
405 * Setattr call. Disallow write attempts if the layer is mounted read-only.
409 struct vop_setattr_args /* {
410 struct vnodeop_desc *a_desc;
413 struct ucred *a_cred;
417 struct vnode *vp = ap->a_vp;
418 struct vattr *vap = ap->a_vap;
420 if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
421 vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
422 vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) &&
423 (vp->v_mount->mnt_flag & MNT_RDONLY))
425 if (vap->va_size != VNOVAL) {
426 switch (vp->v_type) {
433 if (vap->va_flags != VNOVAL)
440 * Disallow write attempts if the filesystem is
443 if (vp->v_mount->mnt_flag & MNT_RDONLY)
448 return (null_bypass((struct vop_generic_args *)ap));
452 * We handle getattr only to change the fsid.
456 struct vop_getattr_args /* {
459 struct ucred *a_cred;
465 if ((error = null_bypass((struct vop_generic_args *)ap)) != 0)
468 ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
473 * Handle to disallow write access if mounted read-only.
477 struct vop_access_args /* {
480 struct ucred *a_cred;
484 struct vnode *vp = ap->a_vp;
485 mode_t mode = ap->a_mode;
488 * Disallow write attempts on read-only layers;
489 * unless the file is a socket, fifo, or a block or
490 * character device resident on the file system.
493 switch (vp->v_type) {
497 if (vp->v_mount->mnt_flag & MNT_RDONLY)
504 return (null_bypass((struct vop_generic_args *)ap));
508 * We must handle open to be able to catch MNT_NODEV and friends.
512 struct vop_open_args /* {
515 struct ucred *a_cred;
519 struct vnode *vp = ap->a_vp;
520 struct vnode *lvp = NULLVPTOLOWERVP(ap->a_vp);
522 if ((vp->v_mount->mnt_flag & MNT_NODEV) &&
523 (lvp->v_type == VBLK || lvp->v_type == VCHR))
526 return (null_bypass((struct vop_generic_args *)ap));
530 * We handle this to eliminate null FS to lower FS
531 * file moving. Don't know why we don't allow this,
532 * possibly we should.
536 struct vop_rename_args /* {
537 struct vnode *a_fdvp;
539 struct componentname *a_fcnp;
540 struct vnode *a_tdvp;
542 struct componentname *a_tcnp;
545 struct vnode *tdvp = ap->a_tdvp;
546 struct vnode *fvp = ap->a_fvp;
547 struct vnode *fdvp = ap->a_fdvp;
548 struct vnode *tvp = ap->a_tvp;
550 /* Check for cross-device rename. */
551 if ((fvp->v_mount != tdvp->v_mount) ||
552 (tvp && (fvp->v_mount != tvp->v_mount))) {
564 return (null_bypass((struct vop_generic_args *)ap));
568 * We need to process our own vnode lock and then clear the
569 * interlock flag as it applies only to our vnode, not the
570 * vnodes below us on the stack.
574 struct vop_lock_args /* {
580 struct vnode *vp = ap->a_vp;
581 int flags = ap->a_flags;
582 struct proc *p = ap->a_p;
583 struct null_node *np = VTONULL(vp);
587 if (flags & LK_THISLAYER) {
588 if (vp->v_vnlock != NULL) {
589 /* lock is shared across layers */
590 if (flags & LK_INTERLOCK)
591 simple_unlock(&vp->v_interlock);
594 error = lockmgr(&np->null_lock, flags & ~LK_THISLAYER,
595 &vp->v_interlock, p);
599 if (vp->v_vnlock != NULL) {
601 * The lower level has exported a struct lock to us. Use
602 * it so that all vnodes in the stack lock and unlock
603 * simultaneously. Note: we don't DRAIN the lock as DRAIN
604 * decommissions the lock - just because our vnode is
605 * going away doesn't mean the struct lock below us is.
606 * LK_EXCLUSIVE is fine.
608 if ((flags & LK_TYPE_MASK) == LK_DRAIN) {
609 NULLFSDEBUG("null_lock: avoiding LK_DRAIN\n");
610 return(lockmgr(vp->v_vnlock,
611 (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE,
612 &vp->v_interlock, p));
614 return(lockmgr(vp->v_vnlock, flags, &vp->v_interlock, p));
617 * To prevent race conditions involving doing a lookup
618 * on "..", we have to lock the lower node, then lock our
619 * node. Most of the time it won't matter that we lock our
620 * node (as any locking would need the lower one locked
621 * first). But we can LK_DRAIN the upper lock as a step
622 * towards decomissioning it.
624 lvp = NULLVPTOLOWERVP(vp);
626 return (lockmgr(&np->null_lock, flags, &vp->v_interlock, p));
627 if (flags & LK_INTERLOCK) {
629 flags &= ~LK_INTERLOCK;
631 if ((flags & LK_TYPE_MASK) == LK_DRAIN) {
632 error = VOP_LOCK(lvp,
633 (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE, p);
635 error = VOP_LOCK(lvp, flags, p);
638 error = lockmgr(&np->null_lock, flags, &vp->v_interlock, p);
640 VOP_UNLOCK(lvp, 0, p);
645 * We need to process our own vnode unlock and then clear the
646 * interlock flag as it applies only to our vnode, not the
647 * vnodes below us on the stack.
651 struct vop_unlock_args /* {
657 struct vnode *vp = ap->a_vp;
658 int flags = ap->a_flags;
659 struct proc *p = ap->a_p;
660 struct null_node *np = VTONULL(vp);
663 if (vp->v_vnlock != NULL) {
664 if (flags & LK_THISLAYER)
665 return 0; /* the lock is shared across layers */
666 flags &= ~LK_THISLAYER;
667 return (lockmgr(vp->v_vnlock, flags | LK_RELEASE,
668 &vp->v_interlock, p));
670 lvp = NULLVPTOLOWERVP(vp);
672 return (lockmgr(&np->null_lock, flags | LK_RELEASE, &vp->v_interlock, p));
673 if ((flags & LK_THISLAYER) == 0) {
674 if (flags & LK_INTERLOCK) {
676 flags &= ~LK_INTERLOCK;
678 VOP_UNLOCK(lvp, flags, p);
680 flags &= ~LK_THISLAYER;
682 return (lockmgr(&np->null_lock, flags | LK_RELEASE, &vp->v_interlock, p));
687 struct vop_islocked_args /* {
692 struct vnode *vp = ap->a_vp;
693 struct proc *p = ap->a_p;
695 if (vp->v_vnlock != NULL)
696 return (lockstatus(vp->v_vnlock, p));
697 return (lockstatus(&VTONULL(vp)->null_lock, p));
702 * There is no way to tell that someone issued remove/rmdir operation
703 * on the underlying filesystem. For now we just have to release lowevrp
704 * as soon as possible.
708 struct vop_inactive_args /* {
713 struct vnode *vp = ap->a_vp;
714 struct proc *p = ap->a_p;
715 struct null_node *xp = VTONULL(vp);
716 struct vnode *lowervp = xp->null_lowervp;
718 lockmgr(&null_hashlock, LK_EXCLUSIVE, NULL, p);
719 LIST_REMOVE(xp, null_hash);
720 lockmgr(&null_hashlock, LK_RELEASE, NULL, p);
722 xp->null_lowervp = NULLVP;
723 if (vp->v_vnlock != NULL) {
724 vp->v_vnlock = &xp->null_lock; /* we no longer share the lock */
726 VOP_UNLOCK(vp, LK_THISLAYER, p);
730 * Now it is safe to drop references to the lower vnode.
731 * VOP_INACTIVE() will be called by vrele() if necessary.
739 * We can free memory in null_inactive, but we do this
740 * here. (Possible to guard vp->v_data to point somewhere)
744 struct vop_reclaim_args /* {
749 struct vnode *vp = ap->a_vp;
750 void *vdata = vp->v_data;
753 FREE(vdata, M_NULLFSNODE);
760 struct vop_print_args /* {
764 struct vnode *vp = ap->a_vp;
766 printf ("\ttag VT_NULLFS, vp=%p, lowervp=%p\n", vp, NULLVPTOLOWERVP(vp));
767 if (vp->v_vnlock != NULL) {
768 printf("\tvnlock: ");
769 lockmgr_printinfo(vp->v_vnlock);
771 printf("\tnull_lock: ");
772 lockmgr_printinfo(&VTONULL(vp)->null_lock);
779 * Let an underlying filesystem do the work
782 null_createvobject(ap)
783 struct vop_createvobject_args /* {
789 struct vnode *vp = ap->a_vp;
790 struct vnode *lowervp = VTONULL(vp) ? NULLVPTOLOWERVP(vp) : NULL;
793 if (vp->v_type == VNON || lowervp == NULL)
795 error = VOP_CREATEVOBJECT(lowervp, ap->a_cred, ap->a_p);
798 vp->v_flag |= VOBJBUF;
803 * We have nothing to destroy and this operation shouldn't be bypassed.
806 null_destroyvobject(ap)
807 struct vop_destroyvobject_args /* {
811 struct vnode *vp = ap->a_vp;
813 vp->v_flag &= ~VOBJBUF;
819 struct vop_getvobject_args /* {
821 struct vm_object **objpp;
824 struct vnode *lvp = NULLVPTOLOWERVP(ap->a_vp);
828 return (VOP_GETVOBJECT(lvp, ap->a_objpp));
832 * Global vfs data structures
834 vop_t **null_vnodeop_p;
835 static struct vnodeopv_entry_desc null_vnodeop_entries[] = {
836 { &vop_default_desc, (vop_t *) null_bypass },
837 { &vop_access_desc, (vop_t *) null_access },
838 { &vop_createvobject_desc, (vop_t *) null_createvobject },
839 { &vop_destroyvobject_desc, (vop_t *) null_destroyvobject },
840 { &vop_getattr_desc, (vop_t *) null_getattr },
841 { &vop_getvobject_desc, (vop_t *) null_getvobject },
842 { &vop_inactive_desc, (vop_t *) null_inactive },
843 { &vop_islocked_desc, (vop_t *) null_islocked },
844 { &vop_lock_desc, (vop_t *) null_lock },
845 { &vop_lookup_desc, (vop_t *) null_lookup },
846 { &vop_open_desc, (vop_t *) null_open },
847 { &vop_print_desc, (vop_t *) null_print },
848 { &vop_reclaim_desc, (vop_t *) null_reclaim },
849 { &vop_rename_desc, (vop_t *) null_rename },
850 { &vop_setattr_desc, (vop_t *) null_setattr },
851 { &vop_unlock_desc, (vop_t *) null_unlock },
854 static struct vnodeopv_desc null_vnodeop_opv_desc =
855 { &null_vnodeop_p, null_vnodeop_entries };
857 VNODEOP_SET(null_vnodeop_opv_desc);