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-rw-r--r--sys/miscfs/nullfs/null_vnops.c852
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diff --git a/sys/miscfs/nullfs/null_vnops.c b/sys/miscfs/nullfs/null_vnops.c
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index d37ef73..0000000
--- a/sys/miscfs/nullfs/null_vnops.c
+++ /dev/null
@@ -1,852 +0,0 @@
-/*
- * Copyright (c) 1992, 1993
- * The Regents of the University of California. All rights reserved.
- *
- * This code is derived from software contributed to Berkeley by
- * John Heidemann of the UCLA Ficus project.
- *
- * Redistribution and use in source and binary forms, with or without
- * modification, are permitted provided that the following conditions
- * are met:
- * 1. Redistributions of source code must retain the above copyright
- * notice, this list of conditions and the following disclaimer.
- * 2. Redistributions in binary form must reproduce the above copyright
- * notice, this list of conditions and the following disclaimer in the
- * documentation and/or other materials provided with the distribution.
- * 3. All advertising materials mentioning features or use of this software
- * must display the following acknowledgement:
- * This product includes software developed by the University of
- * California, Berkeley and its contributors.
- * 4. Neither the name of the University nor the names of its contributors
- * may be used to endorse or promote products derived from this software
- * without specific prior written permission.
- *
- * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
- * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
- * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
- * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
- * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
- * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
- * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
- * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
- * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
- * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
- * SUCH DAMAGE.
- *
- * @(#)null_vnops.c 8.6 (Berkeley) 5/27/95
- *
- * Ancestors:
- * @(#)lofs_vnops.c 1.2 (Berkeley) 6/18/92
- * ...and...
- * @(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project
- *
- * $FreeBSD$
- */
-
-/*
- * Null Layer
- *
- * (See mount_null(8) for more information.)
- *
- * The null layer duplicates a portion of the file system
- * name space under a new name. In this respect, it is
- * similar to the loopback file system. It differs from
- * the loopback fs in two respects: it is implemented using
- * a stackable layers techniques, and its "null-node"s stack above
- * all lower-layer vnodes, not just over directory vnodes.
- *
- * The null layer has two purposes. First, it serves as a demonstration
- * of layering by proving a layer which does nothing. (It actually
- * does everything the loopback file system does, which is slightly
- * more than nothing.) Second, the null layer can serve as a prototype
- * layer. Since it provides all necessary layer framework,
- * new file system layers can be created very easily be starting
- * with a null layer.
- *
- * The remainder of this man page examines the null layer as a basis
- * for constructing new layers.
- *
- *
- * INSTANTIATING NEW NULL LAYERS
- *
- * New null layers are created with mount_null(8).
- * Mount_null(8) takes two arguments, the pathname
- * of the lower vfs (target-pn) and the pathname where the null
- * layer will appear in the namespace (alias-pn). After
- * the null layer is put into place, the contents
- * of target-pn subtree will be aliased under alias-pn.
- *
- *
- * OPERATION OF A NULL LAYER
- *
- * The null layer is the minimum file system layer,
- * simply bypassing all possible operations to the lower layer
- * for processing there. The majority of its activity centers
- * on the bypass routine, through which nearly all vnode operations
- * pass.
- *
- * The bypass routine accepts arbitrary vnode operations for
- * handling by the lower layer. It begins by examing vnode
- * operation arguments and replacing any null-nodes by their
- * lower-layer equivlants. It then invokes the operation
- * on the lower layer. Finally, it replaces the null-nodes
- * in the arguments and, if a vnode is return by the operation,
- * stacks a null-node on top of the returned vnode.
- *
- * Although bypass handles most operations, vop_getattr, vop_lock,
- * vop_unlock, vop_inactive, vop_reclaim, and vop_print are not
- * bypassed. Vop_getattr must change the fsid being returned.
- * Vop_lock and vop_unlock must handle any locking for the
- * current vnode as well as pass the lock request down.
- * Vop_inactive and vop_reclaim are not bypassed so that
- * they can handle freeing null-layer specific data. Vop_print
- * is not bypassed to avoid excessive debugging information.
- * Also, certain vnode operations change the locking state within
- * the operation (create, mknod, remove, link, rename, mkdir, rmdir,
- * and symlink). Ideally these operations should not change the
- * lock state, but should be changed to let the caller of the
- * function unlock them. Otherwise all intermediate vnode layers
- * (such as union, umapfs, etc) must catch these functions to do
- * the necessary locking at their layer.
- *
- *
- * INSTANTIATING VNODE STACKS
- *
- * Mounting associates the null layer with a lower layer,
- * effect stacking two VFSes. Vnode stacks are instead
- * created on demand as files are accessed.
- *
- * The initial mount creates a single vnode stack for the
- * root of the new null layer. All other vnode stacks
- * are created as a result of vnode operations on
- * this or other null vnode stacks.
- *
- * New vnode stacks come into existance as a result of
- * an operation which returns a vnode.
- * The bypass routine stacks a null-node above the new
- * vnode before returning it to the caller.
- *
- * For example, imagine mounting a null layer with
- * "mount_null /usr/include /dev/layer/null".
- * Changing directory to /dev/layer/null will assign
- * the root null-node (which was created when the null layer was mounted).
- * Now consider opening "sys". A vop_lookup would be
- * done on the root null-node. This operation would bypass through
- * to the lower layer which would return a vnode representing
- * the UFS "sys". Null_bypass then builds a null-node
- * aliasing the UFS "sys" and returns this to the caller.
- * Later operations on the null-node "sys" will repeat this
- * process when constructing other vnode stacks.
- *
- *
- * CREATING OTHER FILE SYSTEM LAYERS
- *
- * One of the easiest ways to construct new file system layers is to make
- * a copy of the null layer, rename all files and variables, and
- * then begin modifing the copy. Sed can be used to easily rename
- * all variables.
- *
- * The umap layer is an example of a layer descended from the
- * null layer.
- *
- *
- * INVOKING OPERATIONS ON LOWER LAYERS
- *
- * There are two techniques to invoke operations on a lower layer
- * when the operation cannot be completely bypassed. Each method
- * is appropriate in different situations. In both cases,
- * it is the responsibility of the aliasing layer to make
- * the operation arguments "correct" for the lower layer
- * by mapping an vnode arguments to the lower layer.
- *
- * The first approach is to call the aliasing layer's bypass routine.
- * This method is most suitable when you wish to invoke the operation
- * currently being handled on the lower layer. It has the advantage
- * that the bypass routine already must do argument mapping.
- * An example of this is null_getattrs in the null layer.
- *
- * A second approach is to directly invoke vnode operations on
- * the lower layer with the VOP_OPERATIONNAME interface.
- * The advantage of this method is that it is easy to invoke
- * arbitrary operations on the lower layer. The disadvantage
- * is that vnode arguments must be manualy mapped.
- *
- */
-
-#include <sys/param.h>
-#include <sys/systm.h>
-#include <sys/conf.h>
-#include <sys/kernel.h>
-#include <sys/lock.h>
-#include <sys/malloc.h>
-#include <sys/mount.h>
-#include <sys/mutex.h>
-#include <sys/namei.h>
-#include <sys/sysctl.h>
-#include <sys/vnode.h>
-
-#include <miscfs/nullfs/null.h>
-
-#include <vm/vm.h>
-#include <vm/vm_extern.h>
-#include <vm/vm_object.h>
-#include <vm/vnode_pager.h>
-
-static int null_bug_bypass = 0; /* for debugging: enables bypass printf'ing */
-SYSCTL_INT(_debug, OID_AUTO, nullfs_bug_bypass, CTLFLAG_RW,
- &null_bug_bypass, 0, "");
-
-static int null_access(struct vop_access_args *ap);
-static int null_createvobject(struct vop_createvobject_args *ap);
-static int null_destroyvobject(struct vop_destroyvobject_args *ap);
-static int null_getattr(struct vop_getattr_args *ap);
-static int null_getvobject(struct vop_getvobject_args *ap);
-static int null_inactive(struct vop_inactive_args *ap);
-static int null_islocked(struct vop_islocked_args *ap);
-static int null_lock(struct vop_lock_args *ap);
-static int null_lookup(struct vop_lookup_args *ap);
-static int null_open(struct vop_open_args *ap);
-static int null_print(struct vop_print_args *ap);
-static int null_reclaim(struct vop_reclaim_args *ap);
-static int null_rename(struct vop_rename_args *ap);
-static int null_setattr(struct vop_setattr_args *ap);
-static int null_unlock(struct vop_unlock_args *ap);
-
-/*
- * This is the 10-Apr-92 bypass routine.
- * This version has been optimized for speed, throwing away some
- * safety checks. It should still always work, but it's not as
- * robust to programmer errors.
- *
- * In general, we map all vnodes going down and unmap them on the way back.
- * As an exception to this, vnodes can be marked "unmapped" by setting
- * the Nth bit in operation's vdesc_flags.
- *
- * Also, some BSD vnode operations have the side effect of vrele'ing
- * their arguments. With stacking, the reference counts are held
- * by the upper node, not the lower one, so we must handle these
- * side-effects here. This is not of concern in Sun-derived systems
- * since there are no such side-effects.
- *
- * This makes the following assumptions:
- * - only one returned vpp
- * - no INOUT vpp's (Sun's vop_open has one of these)
- * - the vnode operation vector of the first vnode should be used
- * to determine what implementation of the op should be invoked
- * - all mapped vnodes are of our vnode-type (NEEDSWORK:
- * problems on rmdir'ing mount points and renaming?)
- */
-int
-null_bypass(ap)
- struct vop_generic_args /* {
- struct vnodeop_desc *a_desc;
- <other random data follows, presumably>
- } */ *ap;
-{
- register struct vnode **this_vp_p;
- int error;
- struct vnode *old_vps[VDESC_MAX_VPS];
- struct vnode **vps_p[VDESC_MAX_VPS];
- struct vnode ***vppp;
- struct vnodeop_desc *descp = ap->a_desc;
- int reles, i;
-
- if (null_bug_bypass)
- printf ("null_bypass: %s\n", descp->vdesc_name);
-
-#ifdef DIAGNOSTIC
- /*
- * We require at least one vp.
- */
- if (descp->vdesc_vp_offsets == NULL ||
- descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
- panic ("null_bypass: no vp's in map");
-#endif
-
- /*
- * Map the vnodes going in.
- * Later, we'll invoke the operation based on
- * the first mapped vnode's operation vector.
- */
- reles = descp->vdesc_flags;
- for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
- if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
- break; /* bail out at end of list */
- vps_p[i] = this_vp_p =
- VOPARG_OFFSETTO(struct vnode**,descp->vdesc_vp_offsets[i],ap);
- /*
- * We're not guaranteed that any but the first vnode
- * are of our type. Check for and don't map any
- * that aren't. (We must always map first vp or vclean fails.)
- */
- if (i && (*this_vp_p == NULLVP ||
- (*this_vp_p)->v_op != null_vnodeop_p)) {
- old_vps[i] = NULLVP;
- } else {
- old_vps[i] = *this_vp_p;
- *(vps_p[i]) = NULLVPTOLOWERVP(*this_vp_p);
- /*
- * XXX - Several operations have the side effect
- * of vrele'ing their vp's. We must account for
- * that. (This should go away in the future.)
- */
- if (reles & VDESC_VP0_WILLRELE)
- VREF(*this_vp_p);
- }
-
- }
-
- /*
- * Call the operation on the lower layer
- * with the modified argument structure.
- */
- if (vps_p[0] && *vps_p[0])
- error = VCALL(*(vps_p[0]), descp->vdesc_offset, ap);
- else {
- printf("null_bypass: no map for %s\n", descp->vdesc_name);
- error = EINVAL;
- }
-
- /*
- * Maintain the illusion of call-by-value
- * by restoring vnodes in the argument structure
- * to their original value.
- */
- reles = descp->vdesc_flags;
- for (i = 0; i < VDESC_MAX_VPS; reles >>= 1, i++) {
- if (descp->vdesc_vp_offsets[i] == VDESC_NO_OFFSET)
- break; /* bail out at end of list */
- if (old_vps[i]) {
- *(vps_p[i]) = old_vps[i];
-#if 0
- if (reles & VDESC_VP0_WILLUNLOCK)
- VOP_UNLOCK(*(vps_p[i]), LK_THISLAYER, curproc);
-#endif
- if (reles & VDESC_VP0_WILLRELE)
- vrele(*(vps_p[i]));
- }
- }
-
- /*
- * Map the possible out-going vpp
- * (Assumes that the lower layer always returns
- * a VREF'ed vpp unless it gets an error.)
- */
- if (descp->vdesc_vpp_offset != VDESC_NO_OFFSET &&
- !(descp->vdesc_flags & VDESC_NOMAP_VPP) &&
- !error) {
- /*
- * XXX - even though some ops have vpp returned vp's,
- * several ops actually vrele this before returning.
- * We must avoid these ops.
- * (This should go away when these ops are regularized.)
- */
- if (descp->vdesc_flags & VDESC_VPP_WILLRELE)
- goto out;
- vppp = VOPARG_OFFSETTO(struct vnode***,
- descp->vdesc_vpp_offset,ap);
- if (*vppp)
- error = null_node_create(old_vps[0]->v_mount, **vppp, *vppp);
- }
-
- out:
- return (error);
-}
-
-/*
- * We have to carry on the locking protocol on the null layer vnodes
- * as we progress through the tree. We also have to enforce read-only
- * if this layer is mounted read-only.
- */
-static int
-null_lookup(ap)
- struct vop_lookup_args /* {
- struct vnode * a_dvp;
- struct vnode ** a_vpp;
- struct componentname * a_cnp;
- } */ *ap;
-{
- struct componentname *cnp = ap->a_cnp;
- struct vnode *dvp = ap->a_dvp;
- struct proc *p = cnp->cn_proc;
- int flags = cnp->cn_flags;
- struct vnode *vp, *ldvp, *lvp;
- int error;
-
- if ((flags & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
- (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
- return (EROFS);
- /*
- * Although it is possible to call null_bypass(), we'll do
- * a direct call to reduce overhead
- */
- ldvp = NULLVPTOLOWERVP(dvp);
- vp = lvp = NULL;
- error = VOP_LOOKUP(ldvp, &lvp, cnp);
- if (error == EJUSTRETURN && (flags & ISLASTCN) &&
- (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
- (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME))
- error = EROFS;
-
- /*
- * Rely only on the PDIRUNLOCK flag which should be carefully
- * tracked by underlying filesystem.
- */
- if (cnp->cn_flags & PDIRUNLOCK)
- VOP_UNLOCK(dvp, LK_THISLAYER, p);
- if ((error == 0 || error == EJUSTRETURN) && lvp != NULL) {
- if (ldvp == lvp) {
- *ap->a_vpp = dvp;
- VREF(dvp);
- vrele(lvp);
- } else {
- error = null_node_create(dvp->v_mount, lvp, &vp);
- if (error == 0)
- *ap->a_vpp = vp;
- }
- }
- return (error);
-}
-
-/*
- * Setattr call. Disallow write attempts if the layer is mounted read-only.
- */
-int
-null_setattr(ap)
- struct vop_setattr_args /* {
- struct vnodeop_desc *a_desc;
- struct vnode *a_vp;
- struct vattr *a_vap;
- struct ucred *a_cred;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- struct vattr *vap = ap->a_vap;
-
- if ((vap->va_flags != VNOVAL || vap->va_uid != (uid_t)VNOVAL ||
- vap->va_gid != (gid_t)VNOVAL || vap->va_atime.tv_sec != VNOVAL ||
- vap->va_mtime.tv_sec != VNOVAL || vap->va_mode != (mode_t)VNOVAL) &&
- (vp->v_mount->mnt_flag & MNT_RDONLY))
- return (EROFS);
- if (vap->va_size != VNOVAL) {
- switch (vp->v_type) {
- case VDIR:
- return (EISDIR);
- case VCHR:
- case VBLK:
- case VSOCK:
- case VFIFO:
- if (vap->va_flags != VNOVAL)
- return (EOPNOTSUPP);
- return (0);
- case VREG:
- case VLNK:
- default:
- /*
- * Disallow write attempts if the filesystem is
- * mounted read-only.
- */
- if (vp->v_mount->mnt_flag & MNT_RDONLY)
- return (EROFS);
- }
- }
-
- return (null_bypass((struct vop_generic_args *)ap));
-}
-
-/*
- * We handle getattr only to change the fsid.
- */
-static int
-null_getattr(ap)
- struct vop_getattr_args /* {
- struct vnode *a_vp;
- struct vattr *a_vap;
- struct ucred *a_cred;
- struct proc *a_p;
- } */ *ap;
-{
- int error;
-
- if ((error = null_bypass((struct vop_generic_args *)ap)) != 0)
- return (error);
-
- ap->a_vap->va_fsid = ap->a_vp->v_mount->mnt_stat.f_fsid.val[0];
- return (0);
-}
-
-/*
- * Handle to disallow write access if mounted read-only.
- */
-static int
-null_access(ap)
- struct vop_access_args /* {
- struct vnode *a_vp;
- int a_mode;
- struct ucred *a_cred;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- mode_t mode = ap->a_mode;
-
- /*
- * Disallow write attempts on read-only layers;
- * unless the file is a socket, fifo, or a block or
- * character device resident on the file system.
- */
- if (mode & VWRITE) {
- switch (vp->v_type) {
- case VDIR:
- case VLNK:
- case VREG:
- if (vp->v_mount->mnt_flag & MNT_RDONLY)
- return (EROFS);
- break;
- default:
- break;
- }
- }
- return (null_bypass((struct vop_generic_args *)ap));
-}
-
-/*
- * We must handle open to be able to catch MNT_NODEV and friends.
- */
-static int
-null_open(ap)
- struct vop_open_args /* {
- struct vnode *a_vp;
- int a_mode;
- struct ucred *a_cred;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- struct vnode *lvp = NULLVPTOLOWERVP(ap->a_vp);
-
- if ((vp->v_mount->mnt_flag & MNT_NODEV) &&
- (lvp->v_type == VBLK || lvp->v_type == VCHR))
- return ENXIO;
-
- return (null_bypass((struct vop_generic_args *)ap));
-}
-
-/*
- * We handle this to eliminate null FS to lower FS
- * file moving. Don't know why we don't allow this,
- * possibly we should.
- */
-static int
-null_rename(ap)
- struct vop_rename_args /* {
- struct vnode *a_fdvp;
- struct vnode *a_fvp;
- struct componentname *a_fcnp;
- struct vnode *a_tdvp;
- struct vnode *a_tvp;
- struct componentname *a_tcnp;
- } */ *ap;
-{
- struct vnode *tdvp = ap->a_tdvp;
- struct vnode *fvp = ap->a_fvp;
- struct vnode *fdvp = ap->a_fdvp;
- struct vnode *tvp = ap->a_tvp;
-
- /* Check for cross-device rename. */
- if ((fvp->v_mount != tdvp->v_mount) ||
- (tvp && (fvp->v_mount != tvp->v_mount))) {
- if (tdvp == tvp)
- vrele(tdvp);
- else
- vput(tdvp);
- if (tvp)
- vput(tvp);
- vrele(fdvp);
- vrele(fvp);
- return (EXDEV);
- }
-
- return (null_bypass((struct vop_generic_args *)ap));
-}
-
-/*
- * We need to process our own vnode lock and then clear the
- * interlock flag as it applies only to our vnode, not the
- * vnodes below us on the stack.
- */
-static int
-null_lock(ap)
- struct vop_lock_args /* {
- struct vnode *a_vp;
- int a_flags;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- int flags = ap->a_flags;
- struct proc *p = ap->a_p;
- struct vnode *lvp;
- int error;
-
- if (flags & LK_THISLAYER) {
- if (vp->v_vnlock != NULL)
- return 0; /* lock is shared across layers */
- error = lockmgr(&vp->v_lock, flags & ~LK_THISLAYER,
- &vp->v_interlock, p);
- return (error);
- }
-
- if (vp->v_vnlock != NULL) {
- /*
- * The lower level has exported a struct lock to us. Use
- * it so that all vnodes in the stack lock and unlock
- * simultaneously. Note: we don't DRAIN the lock as DRAIN
- * decommissions the lock - just because our vnode is
- * going away doesn't mean the struct lock below us is.
- * LK_EXCLUSIVE is fine.
- */
- if ((flags & LK_TYPE_MASK) == LK_DRAIN) {
- NULLFSDEBUG("null_lock: avoiding LK_DRAIN\n");
- return(lockmgr(vp->v_vnlock,
- (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE,
- &vp->v_interlock, p));
- }
- return(lockmgr(vp->v_vnlock, flags, &vp->v_interlock, p));
- } else {
- /*
- * To prevent race conditions involving doing a lookup
- * on "..", we have to lock the lower node, then lock our
- * node. Most of the time it won't matter that we lock our
- * node (as any locking would need the lower one locked
- * first). But we can LK_DRAIN the upper lock as a step
- * towards decomissioning it.
- */
- lvp = NULLVPTOLOWERVP(vp);
- if (lvp == NULL)
- return (lockmgr(&vp->v_lock, flags, &vp->v_interlock, p));
- if (flags & LK_INTERLOCK) {
- mtx_unlock(&vp->v_interlock);
- flags &= ~LK_INTERLOCK;
- }
- if ((flags & LK_TYPE_MASK) == LK_DRAIN) {
- error = VOP_LOCK(lvp,
- (flags & ~LK_TYPE_MASK) | LK_EXCLUSIVE, p);
- } else
- error = VOP_LOCK(lvp, flags, p);
- if (error)
- return (error);
- error = lockmgr(&vp->v_lock, flags, &vp->v_interlock, p);
- if (error)
- VOP_UNLOCK(lvp, 0, p);
- return (error);
- }
-}
-
-/*
- * We need to process our own vnode unlock and then clear the
- * interlock flag as it applies only to our vnode, not the
- * vnodes below us on the stack.
- */
-static int
-null_unlock(ap)
- struct vop_unlock_args /* {
- struct vnode *a_vp;
- int a_flags;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- int flags = ap->a_flags;
- struct proc *p = ap->a_p;
- struct vnode *lvp;
-
- if (vp->v_vnlock != NULL) {
- if (flags & LK_THISLAYER)
- return 0; /* the lock is shared across layers */
- flags &= ~LK_THISLAYER;
- return (lockmgr(vp->v_vnlock, flags | LK_RELEASE,
- &vp->v_interlock, p));
- }
- lvp = NULLVPTOLOWERVP(vp);
- if (lvp == NULL)
- return (lockmgr(&vp->v_lock, flags | LK_RELEASE, &vp->v_interlock, p));
- if ((flags & LK_THISLAYER) == 0) {
- if (flags & LK_INTERLOCK) {
- mtx_unlock(&vp->v_interlock);
- flags &= ~LK_INTERLOCK;
- }
- VOP_UNLOCK(lvp, flags & ~LK_INTERLOCK, p);
- } else
- flags &= ~LK_THISLAYER;
- return (lockmgr(&vp->v_lock, flags | LK_RELEASE, &vp->v_interlock, p));
-}
-
-static int
-null_islocked(ap)
- struct vop_islocked_args /* {
- struct vnode *a_vp;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- struct proc *p = ap->a_p;
-
- if (vp->v_vnlock != NULL)
- return (lockstatus(vp->v_vnlock, p));
- return (lockstatus(&vp->v_lock, p));
-}
-
-/*
- * There is no way to tell that someone issued remove/rmdir operation
- * on the underlying filesystem. For now we just have to release lowevrp
- * as soon as possible.
- */
-static int
-null_inactive(ap)
- struct vop_inactive_args /* {
- struct vnode *a_vp;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- struct proc *p = ap->a_p;
- struct null_node *xp = VTONULL(vp);
- struct vnode *lowervp = xp->null_lowervp;
-
- lockmgr(&null_hashlock, LK_EXCLUSIVE, NULL, p);
- LIST_REMOVE(xp, null_hash);
- lockmgr(&null_hashlock, LK_RELEASE, NULL, p);
-
- xp->null_lowervp = NULLVP;
- if (vp->v_vnlock != NULL) {
- vp->v_vnlock = &vp->v_lock; /* we no longer share the lock */
- } else
- VOP_UNLOCK(vp, LK_THISLAYER, p);
-
- vput(lowervp);
- /*
- * Now it is safe to drop references to the lower vnode.
- * VOP_INACTIVE() will be called by vrele() if necessary.
- */
- vrele (lowervp);
-
- return (0);
-}
-
-/*
- * We can free memory in null_inactive, but we do this
- * here. (Possible to guard vp->v_data to point somewhere)
- */
-static int
-null_reclaim(ap)
- struct vop_reclaim_args /* {
- struct vnode *a_vp;
- struct proc *a_p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- void *vdata = vp->v_data;
-
- vp->v_data = NULL;
- FREE(vdata, M_NULLFSNODE);
-
- return (0);
-}
-
-static int
-null_print(ap)
- struct vop_print_args /* {
- struct vnode *a_vp;
- } */ *ap;
-{
- register struct vnode *vp = ap->a_vp;
- printf ("\ttag VT_NULLFS, vp=%p, lowervp=%p\n", vp, NULLVPTOLOWERVP(vp));
- return (0);
-}
-
-/*
- * Let an underlying filesystem do the work
- */
-static int
-null_createvobject(ap)
- struct vop_createvobject_args /* {
- struct vnode *vp;
- struct ucred *cred;
- struct proc *p;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
- struct vnode *lowervp = VTONULL(vp) ? NULLVPTOLOWERVP(vp) : NULL;
- int error;
-
- if (vp->v_type == VNON || lowervp == NULL)
- return 0;
- error = VOP_CREATEVOBJECT(lowervp, ap->a_cred, ap->a_p);
- if (error)
- return (error);
- vp->v_flag |= VOBJBUF;
- return (0);
-}
-
-/*
- * We have nothing to destroy and this operation shouldn't be bypassed.
- */
-static int
-null_destroyvobject(ap)
- struct vop_destroyvobject_args /* {
- struct vnode *vp;
- } */ *ap;
-{
- struct vnode *vp = ap->a_vp;
-
- vp->v_flag &= ~VOBJBUF;
- return (0);
-}
-
-static int
-null_getvobject(ap)
- struct vop_getvobject_args /* {
- struct vnode *vp;
- struct vm_object **objpp;
- } */ *ap;
-{
- struct vnode *lvp = NULLVPTOLOWERVP(ap->a_vp);
-
- if (lvp == NULL)
- return EINVAL;
- return (VOP_GETVOBJECT(lvp, ap->a_objpp));
-}
-
-/*
- * Global vfs data structures
- */
-vop_t **null_vnodeop_p;
-static struct vnodeopv_entry_desc null_vnodeop_entries[] = {
- { &vop_default_desc, (vop_t *) null_bypass },
-
- { &vop_access_desc, (vop_t *) null_access },
- { &vop_bmap_desc, (vop_t *) vop_eopnotsupp },
- { &vop_createvobject_desc, (vop_t *) null_createvobject },
- { &vop_destroyvobject_desc, (vop_t *) null_destroyvobject },
- { &vop_getattr_desc, (vop_t *) null_getattr },
- { &vop_getvobject_desc, (vop_t *) null_getvobject },
- { &vop_getwritemount_desc, (vop_t *) vop_stdgetwritemount},
- { &vop_inactive_desc, (vop_t *) null_inactive },
- { &vop_islocked_desc, (vop_t *) null_islocked },
- { &vop_lock_desc, (vop_t *) null_lock },
- { &vop_lookup_desc, (vop_t *) null_lookup },
- { &vop_open_desc, (vop_t *) null_open },
- { &vop_print_desc, (vop_t *) null_print },
- { &vop_reclaim_desc, (vop_t *) null_reclaim },
- { &vop_rename_desc, (vop_t *) null_rename },
- { &vop_setattr_desc, (vop_t *) null_setattr },
- { &vop_strategy_desc, (vop_t *) vop_eopnotsupp },
- { &vop_unlock_desc, (vop_t *) null_unlock },
- { NULL, NULL }
-};
-static struct vnodeopv_desc null_vnodeop_opv_desc =
- { &null_vnodeop_p, null_vnodeop_entries };
-
-VNODEOP_SET(null_vnodeop_opv_desc);
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