 @@ -1,994 +1,995 @@
-/*	$NetBSD: layer_vnops.c,v 1.35 2008/01/30 09:50:23 ad Exp $	*/
+/*	$NetBSD: layer_vnops.c,v 1.36 2009/01/03 04:38:07 dholland Exp $	*/
 /*
  * Copyright (c) 1999 National Aeronautics & Space Administration
  * All rights reserved.
+ *
  * This software was written by William Studenmund of the
  * Numerical Aerospace Simulation Facility, NASA Ames Research Center.
+ *
  * 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. Neither the name of the National Aeronautics & Space Administration
  *    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 NATIONAL AERONAUTICS & SPACE ADMINISTRATION
  * ``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 ADMINISTRATION OR CONTRIB-
  * UTORS 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.
  */
 /*
  * 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. 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
  *	Id: lofs_vnops.c,v 1.11 1992/05/30 10:05:43 jsp Exp jsp
  *	...and...
  *	@(#)null_vnodeops.c 1.20 92/07/07 UCLA Ficus project
  */
 /*
  * Null Layer vnode routines.
+ *
  * (See mount_null(8) for more information.)
+ *
  * The layer.h, layer_extern.h, layer_vfs.c, and layer_vnops.c files provide
  * the core implementation of the null file system and most other stacked
  * fs's. The description below refers to the null file system, but the
  * services provided by the layer* files are useful for all layered fs's.
+ *
  * 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 it's "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 the 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.
+ *
  * It is conceivable that other overlay filesystems will take different
  * parameters. For instance, data migration or access controll layers might
  * only take one pathname which will serve both as the target-pn and
  * alias-pn described above.
+ *
+ *
  * 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 layered nodes by their
  * lower-layer equivalents.  It then invokes the operation
  * on the lower layer.  Finally, it replaces the layered nodes
  * in the arguments and, if a vnode is return by the operation,
  * stacks a layered node on top of the returned vnode.
+ *
  * The bypass routine in this file, layer_bypass(), is suitable for use
  * by many different layered filesystems. It can be used by multiple
  * filesystems simultaneously. Alternatively, a layered fs may provide
  * its own bypass routine, in which case layer_bypass() should be used as
  * a model. For instance, the main functionality provided by umapfs, the user
  * identity mapping file system, is handled by a custom bypass routine.
+ *
  * Typically a layered fs registers its selected bypass routine as the
  * default vnode operation in its vnodeopv_entry_desc table. Additionally
  * the filesystem must store the bypass entry point in the layerm_bypass
  * field of struct layer_mount. All other layer routines in this file will
  * use the layerm_bypass routine.
+ *
  * Although the bypass routine handles most operations outright, a number
  * of operations are special cased, and handled by the layered fs. One
  * group, layer_setattr, layer_getattr, layer_access, layer_open, and
  * layer_fsync, perform layer-specific manipulation in addition to calling
  * the bypass routine. The other group
  * 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 existence 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".  layer_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 vnodes' arguments must be manually mapped.
+ *
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.35 2008/01/30 09:50:23 ad Exp $");
+__KERNEL_RCSID(0, "$NetBSD: layer_vnops.c,v 1.36 2009/01/03 04:38:07 dholland Exp $");
 #include <sys/param.h>
 #include <sys/systm.h>
 #include <sys/proc.h>
 #include <sys/time.h>
 #include <sys/vnode.h>
 #include <sys/mount.h>
 #include <sys/namei.h>
 #include <sys/kmem.h>
 #include <sys/buf.h>
 #include <sys/kauth.h>
 #include <miscfs/genfs/layer.h>
 #include <miscfs/genfs/layer_extern.h>
 #include <miscfs/genfs/genfs.h>
 /*
  * This is the 08-June-99 bypass routine, based on the 10-Apr-92 bypass
  *		routine by John Heidemann.
  *	The new element for this version is that the whole nullfs
  * system gained the concept of locks on the lower node, and locks on
  * our nodes. When returning from a call to the lower layer, we may
  * need to update lock state ONLY on our layer. The LAYERFS_UPPER*LOCK()
  * macros provide this functionality.
  *    The 10-Apr-92 version was optimized for speed, throwing away some
  * safety checks.  It should still always work, but it's not as
  * robust to programmer errors.
  *    Define SAFETY to include some error checking code.
+ *
  * In general, we map all vnodes going down and unmap them on the way back.
+ *
  * 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.
+ *
  * New for the 08-June-99 version: we also handle operations which unlock
  * the passed-in node (typically they vput the node).
+ *
  * 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
 layer_bypass(v)
 	void *v;
+{
 	struct vop_generic_args /* {
 		struct vnodeop_desc *a_desc;
 		<other random data follows, presumably>
 	} */ *ap = v;
 	int (**our_vnodeop_p)(void *);
 	struct vnode **this_vp_p;
 	int error, error1;
 	struct vnode *old_vps[VDESC_MAX_VPS], *vp0;
 	struct vnode **vps_p[VDESC_MAX_VPS];
 	struct vnode ***vppp;
 	struct mount *mp;
 	struct vnodeop_desc *descp = ap->a_desc;
 	int reles, i, flags;
 #ifdef SAFETY
 	/*
 	 * We require at least one vp.
 	 */
 	if (descp->vdesc_vp_offsets == NULL ||
 	    descp->vdesc_vp_offsets[0] == VDESC_NO_OFFSET)
 		panic("%s: no vp's in map.\n", __func__);
 #endif
 	vps_p[0] =
 	    VOPARG_OFFSETTO(struct vnode**, descp->vdesc_vp_offsets[0], ap);
 	vp0 = *vps_p[0];
 	mp = vp0->v_mount;
 	flags = MOUNTTOLAYERMOUNT(mp)->layerm_flags;
 	our_vnodeop_p = vp0->v_op;
 	if (flags & LAYERFS_MBYPASSDEBUG)
 		printf("%s: %s\n", __func__, descp->vdesc_name);
 	/*
 	 * 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 == NULL ||
 		    (*this_vp_p)->v_op != our_vnodeop_p)) {
 			old_vps[i] = NULL;
 		} else {
 			old_vps[i] = *this_vp_p;
 			*(vps_p[i]) = LAYERVPTOLOWERVP(*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.
 	 */
 	error = VCALL(*vps_p[0], descp->vdesc_offset, ap);
 	/*
 	 * 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 (reles & VDESC_VP0_WILLUNLOCK)
 				LAYERFS_UPPERUNLOCK(*(vps_p[i]), 0, error1);
 			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);
 		/*
 		 * Only vop_lookup, vop_create, vop_makedir, vop_bmap,
 		 * vop_mknod, and vop_symlink return vpp's. vop_bmap
 		 * doesn't call bypass as the lower vpp is fine (we're just
 		 * going to do i/o on it). vop_lookup doesn't call bypass
 		 * as a lookup on "." would generate a locking error.
 		 * So all the calls which get us here have a locked vpp. :-)
 		 */
 		error = layer_node_create(mp, **vppp, *vppp);
 		if (error) {
 			vput(**vppp);
 			**vppp = NULL;
+		}
+	}
  out:
 	return (error);
+}
 /*
  * We have to carry on the locking protocol on the layer vnodes
  * as we progress through the tree. We also have to enforce read-only
  * if this layer is mounted read-only.
  */
 int
 layer_lookup(v)
 	void *v;
+{
 	struct vop_lookup_args /* {
 		struct vnodeop_desc *a_desc;
 		struct vnode * a_dvp;
 		struct vnode ** a_vpp;
 		struct componentname * a_cnp;
 	} */ *ap = v;
 	struct componentname *cnp = ap->a_cnp;
 	int flags = cnp->cn_flags;
 	struct vnode *dvp, *lvp, *ldvp;
 	int error;
 	dvp = ap->a_dvp;
 	if ((flags & ISLASTCN) && (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
 	    (cnp->cn_nameiop == DELETE || cnp->cn_nameiop == RENAME))
 		return (EROFS);
 	ldvp = LAYERVPTOLOWERVP(dvp);
 	ap->a_dvp = ldvp;
 	error = VCALL(ldvp, ap->a_desc->vdesc_offset, ap);
 	lvp = *ap->a_vpp;
 	*ap->a_vpp = NULL;
 	if (error == EJUSTRETURN && (flags & ISLASTCN) &&
 	    (dvp->v_mount->mnt_flag & MNT_RDONLY) &&
 	    (cnp->cn_nameiop == CREATE || cnp->cn_nameiop == RENAME))
 		error = EROFS;
 	/*
 	 * We must do the same locking and unlocking at this layer as
 	 * is done in the layers below us.
 	 */
 	if (ldvp == lvp) {
 		/*
-		 * Did lookup on "." or ".." in the root node of a mount point.
+		 * Got the same object back, because we looked up ".",
-		 * So we return dvp after a VREF.
+		 * or ".." in the root node of a mount point.
 		 * So we make another reference to dvp and return it.
 		 */
 		VREF(dvp);
 		*ap->a_vpp = dvp;
 		vrele(lvp);
 	} else if (lvp != NULL) {
 		/* dvp, ldvp and vp are all locked */
 		error = layer_node_create(dvp->v_mount, lvp, ap->a_vpp);
 		if (error) {
 			vput(lvp);
+		}
+	}
 	return (error);
+}
 /*
  * Setattr call. Disallow write attempts if the layer is mounted read-only.
  */
 int
 layer_setattr(v)
 	void *v;
+{
 	struct vop_setattr_args /* {
 		struct vnodeop_desc *a_desc;
 		struct vnode *a_vp;
 		struct vattr *a_vap;
 		kauth_cred_t a_cred;
 		struct lwp *a_l;
 	} */ *ap = v;
 	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:
 			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 (LAYERFS_DO_BYPASS(vp, ap));
+}
 /*
  *  We handle getattr only to change the fsid.
  */
 int
 layer_getattr(v)
 	void *v;
+{
 	struct vop_getattr_args /* {
 		struct vnode *a_vp;
 		struct vattr *a_vap;
 		kauth_cred_t a_cred;
 		struct lwp *a_l;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	int error;
 	if ((error = LAYERFS_DO_BYPASS(vp, ap)) != 0)
 		return (error);
 	/* Requires that arguments be restored. */
 	ap->a_vap->va_fsid = vp->v_mount->mnt_stat.f_fsidx.__fsid_val[0];
 	return (0);
+}
 int
 layer_access(v)
 	void *v;
+{
 	struct vop_access_args /* {
 		struct vnode *a_vp;
 		int  a_mode;
 		kauth_cred_t a_cred;
 		struct lwp *a_l;
 	} */ *ap = v;
 	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 (LAYERFS_DO_BYPASS(vp, ap));
+}
 /*
  * We must handle open to be able to catch MNT_NODEV and friends.
  */
 int
 layer_open(v)
 	void *v;
+{
 	struct vop_open_args *ap = v;
 	struct vnode *vp = ap->a_vp;
 	enum vtype lower_type = LAYERVPTOLOWERVP(vp)->v_type;
 	if (((lower_type == VBLK) || (lower_type == VCHR)) &&
 	    (vp->v_mount->mnt_flag & MNT_NODEV))
 		return ENXIO;
 	return LAYERFS_DO_BYPASS(vp, 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.
  */
 int
 layer_lock(v)
 	void *v;
+{
 	struct vop_lock_args /* {
 		struct vnode *a_vp;
 		int a_flags;
 		struct proc *a_p;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp, *lowervp;
 	int	flags = ap->a_flags, error;
 	if (flags & LK_INTERLOCK) {
 		mutex_exit(&vp->v_interlock);
 		flags &= ~LK_INTERLOCK;
+	}
 	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.
 		 */
 		return (vlockmgr(vp->v_vnlock, flags));
 	} else {
 		/*
 		 * Ahh well. It would be nice if the fs we're over would
 		 * export a struct lock for us to use, but it doesn't.
+		 *
 		 * 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).
 		 */
 		lowervp = LAYERVPTOLOWERVP(vp);
 		error = VOP_LOCK(lowervp, flags);
 		if (error)
 			return (error);
 		if ((error = vlockmgr(&vp->v_lock, flags))) {
 			VOP_UNLOCK(lowervp, 0);
+		}
 		return (error);
+	}
+}
 /*
  */
 int
 layer_unlock(v)
 	void *v;
+{
 	struct vop_unlock_args /* {
 		struct vnode *a_vp;
 		int a_flags;
 		struct proc *a_p;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	int	flags = ap->a_flags;
 	if (flags & LK_INTERLOCK) {
 		mutex_exit(&vp->v_interlock);
 		flags &= ~LK_INTERLOCK;
+	}
 	if (vp->v_vnlock != NULL) {
 		return (vlockmgr(vp->v_vnlock, ap->a_flags | LK_RELEASE));
 	} else {
 		VOP_UNLOCK(LAYERVPTOLOWERVP(vp), flags);
 		return (vlockmgr(&vp->v_lock, flags | LK_RELEASE));
+	}
+}
 int
 layer_islocked(v)
 	void *v;
+{
 	struct vop_islocked_args /* {
 		struct vnode *a_vp;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	int lkstatus;
 	if (vp->v_vnlock != NULL)
 		return vlockstatus(vp->v_vnlock);
 	lkstatus = VOP_ISLOCKED(LAYERVPTOLOWERVP(vp));
 	if (lkstatus)
 		return lkstatus;
 	return vlockstatus(&vp->v_lock);
+}
 /*
  * If vinvalbuf is calling us, it's a "shallow fsync" -- don't bother
  * syncing the underlying vnodes, since they'll be fsync'ed when
  * reclaimed; otherwise,
  * pass it through to the underlying layer.
+ *
  * XXX Do we still need to worry about shallow fsync?
  */
 int
 layer_fsync(v)
 	void *v;
+{
 	struct vop_fsync_args /* {
 		struct vnode *a_vp;
 		kauth_cred_t a_cred;
 		int  a_flags;
 		off_t offlo;
 		off_t offhi;
 		struct lwp *a_l;
 	} */ *ap = v;
 	if (ap->a_flags & FSYNC_RECLAIM) {
 		return 0;
+	}
 	return (LAYERFS_DO_BYPASS(ap->a_vp, ap));
+}
 int
 layer_inactive(v)
 	void *v;
+{
 	struct vop_inactive_args /* {
 		struct vnode *a_vp;
 		bool *a_recycle;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	/*
 	 * ..., but don't cache the device node. Also, if we did a
 	 * remove, don't cache the node.
 	 */
 	*ap->a_recycle = (vp->v_type == VBLK || vp->v_type == VCHR
 	    || (VTOLAYER(vp)->layer_flags & LAYERFS_REMOVED));
 	/*
 	 * Do nothing (and _don't_ bypass).
 	 * Wait to vrele lowervp until reclaim,
 	 * so that until then our layer_node is in the
 	 * cache and reusable.
+	 *
 	 * NEEDSWORK: Someday, consider inactive'ing
 	 * the lowervp and then trying to reactivate it
 	 * with capabilities (v_id)
 	 * like they do in the name lookup cache code.
 	 * That's too much work for now.
 	 */
 	VOP_UNLOCK(vp, 0);
 	return (0);
+}
 int
 layer_remove(v)
 	void *v;
+{
 	struct vop_remove_args /* {
 		struct vonde		*a_dvp;
 		struct vnode		*a_vp;
 		struct componentname	*a_cnp;
 	} */ *ap = v;
 	int		error;
 	struct vnode	*vp = ap->a_vp;
 	vref(vp);
 	if ((error = LAYERFS_DO_BYPASS(vp, ap)) == 0)
 		VTOLAYER(vp)->layer_flags |= LAYERFS_REMOVED;
 	vrele(vp);
 	return (error);
+}
 int
 layer_rename(v)
 	void *v;
+{
 	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 = v;
 	int error;
 	struct vnode *fdvp = ap->a_fdvp;
 	struct vnode *tvp;
 	tvp = ap->a_tvp;
 	if (tvp) {
 		if (tvp->v_mount != fdvp->v_mount)
 			tvp = NULL;
 		else
 			vref(tvp);
+	}
 	error = LAYERFS_DO_BYPASS(fdvp, ap);
 	if (tvp) {
 		if (error == 0)
 			VTOLAYER(tvp)->layer_flags |= LAYERFS_REMOVED;
 		vrele(tvp);
+	}
 	return (error);
+}
 int
 layer_rmdir(v)
 	void *v;
+{
 	struct vop_rmdir_args /* {
 		struct vnode		*a_dvp;
 		struct vnode		*a_vp;
 		struct componentname	*a_cnp;
 	} */ *ap = v;
 	int		error;
 	struct vnode	*vp = ap->a_vp;
 	vref(vp);
 	if ((error = LAYERFS_DO_BYPASS(vp, ap)) == 0)
 		VTOLAYER(vp)->layer_flags |= LAYERFS_REMOVED;
 	vrele(vp);
 	return (error);
+}
 int
 layer_reclaim(v)
 	void *v;
+{
 	struct vop_reclaim_args /* {
 		struct vnode *a_vp;
 		struct lwp *a_l;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	struct layer_mount *lmp = MOUNTTOLAYERMOUNT(vp->v_mount);
 	struct layer_node *xp = VTOLAYER(vp);
 	struct vnode *lowervp = xp->layer_lowervp;
 	/*
 	 * Note: in vop_reclaim, the node's struct lock has been
 	 * decomissioned, so we have to be careful about calling
 	 * VOP's on ourself.  We must be careful as VXLOCK is set.
 	 */
 	/* After this assignment, this node will not be re-used. */
 	if ((vp == lmp->layerm_rootvp)) {
 		/*
 		 * Oops! We no longer have a root node. Most likely reason is
 		 * that someone forcably unmunted the underlying fs.
+		 *
 		 * Now getting the root vnode will fail. We're dead. :-(
 		 */
 		lmp->layerm_rootvp = NULL;
+	}
 	xp->layer_lowervp = NULL;
 	mutex_enter(&lmp->layerm_hashlock);
 	LIST_REMOVE(xp, layer_hash);
 	mutex_exit(&lmp->layerm_hashlock);
 	kmem_free(vp->v_data, lmp->layerm_size);
 	vp->v_data = NULL;
 	vrele(lowervp);
 	return (0);
+}
 /*
  * We just feed the returned vnode up to the caller - there's no need
  * to build a layer node on top of the node on which we're going to do
  * i/o. :-)
  */
 int
 layer_bmap(v)
 	void *v;
+{
 	struct vop_bmap_args /* {
 		struct vnode *a_vp;
 		daddr_t  a_bn;
 		struct vnode **a_vpp;
 		daddr_t *a_bnp;
 		int *a_runp;
 	} */ *ap = v;
 	struct vnode *vp;
 	ap->a_vp = vp = LAYERVPTOLOWERVP(ap->a_vp);
 	return (VCALL(vp, ap->a_desc->vdesc_offset, ap));
+}
 int
 layer_print(v)
 	void *v;
+{
 	struct vop_print_args /* {
 		struct vnode *a_vp;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	printf ("\ttag VT_LAYERFS, vp=%p, lowervp=%p\n", vp, LAYERVPTOLOWERVP(vp));
 	return (0);
+}
 /*
  * XXX - vop_bwrite must be hand coded because it has no
  * vnode in its arguments.
  * This goes away with a merged VM/buffer cache.
  */
 int
 layer_bwrite(v)
 	void *v;
+{
 	struct vop_bwrite_args /* {
 		struct buf *a_bp;
 	} */ *ap = v;
 	struct buf *bp = ap->a_bp;
 	int error;
 	struct vnode *savedvp;
 	savedvp = bp->b_vp;
 	bp->b_vp = LAYERVPTOLOWERVP(bp->b_vp);
 	error = VOP_BWRITE(bp);
 	bp->b_vp = savedvp;
 	return (error);
+}
 int
 layer_getpages(v)
 	void *v;
+{
 	struct vop_getpages_args /* {
 		struct vnode *a_vp;
 		voff_t a_offset;
 		struct vm_page **a_m;
 		int *a_count;
 		int a_centeridx;
 		vm_prot_t a_access_type;
 		int a_advice;
 		int a_flags;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	int error;
 	/*
 	 * just pass the request on to the underlying layer.
 	 */
 	if (ap->a_flags & PGO_LOCKED) {
 		return EBUSY;
+	}
 	ap->a_vp = LAYERVPTOLOWERVP(vp);
 	mutex_exit(&vp->v_interlock);
 	mutex_enter(&ap->a_vp->v_interlock);
 	error = VCALL(ap->a_vp, VOFFSET(vop_getpages), ap);
 	return error;
+}
 int
 layer_putpages(v)
 	void *v;
+{
 	struct vop_putpages_args /* {
 		struct vnode *a_vp;
 		voff_t a_offlo;
 		voff_t a_offhi;
 		int a_flags;
 	} */ *ap = v;
 	struct vnode *vp = ap->a_vp;
 	int error;
 	/*
 	 * just pass the request on to the underlying layer.
 	 */
 	ap->a_vp = LAYERVPTOLOWERVP(vp);
 	mutex_exit(&vp->v_interlock);
 	if (ap->a_flags & PGO_RECLAIM) {
 		return 0;
+	}
 	mutex_enter(&ap->a_vp->v_interlock);
 	error = VCALL(ap->a_vp, VOFFSET(vop_putpages), ap);
 	return error;
+}