 @@ -1,1435 +1,1448 @@
-/*	$NetBSD: vfs_mount.c,v 1.48 2017/02/22 09:50:13 hannken Exp $	*/
+/*	$NetBSD: vfs_mount.c,v 1.49 2017/03/06 10:10:43 hannken Exp $	*/
 /*-
  * Copyright (c) 1997-2011 The NetBSD Foundation, Inc.
  * All rights reserved.
+ *
  * This code is derived from software contributed to The NetBSD Foundation
  * by Jason R. Thorpe of the Numerical Aerospace Simulation Facility,
  * NASA Ames Research Center, by Charles M. Hannum, and by Andrew Doran.
+ *
  * 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.
+ *
  * THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. 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 FOUNDATION 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.
  */
 /*
  * Copyright (c) 1989, 1993
  *	The Regents of the University of California.  All rights reserved.
  * (c) UNIX System Laboratories, Inc.
  * All or some portions of this file are derived from material licensed
  * to the University of California by American Telephone and Telegraph
  * Co. or Unix System Laboratories, Inc. and are reproduced herein with
  * the permission of UNIX System Laboratories, Inc.
+ *
  * 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.
+ *
  *	@(#)vfs_subr.c	8.13 (Berkeley) 4/18/94
  */
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.48 2017/02/22 09:50:13 hannken Exp $");
+__KERNEL_RCSID(0, "$NetBSD: vfs_mount.c,v 1.49 2017/03/06 10:10:43 hannken Exp $");
 #include <sys/param.h>
 #include <sys/kernel.h>
 #include <sys/atomic.h>
 #include <sys/buf.h>
 #include <sys/conf.h>
 #include <sys/fcntl.h>
 #include <sys/filedesc.h>
 #include <sys/device.h>
 #include <sys/kauth.h>
 #include <sys/kmem.h>
 #include <sys/module.h>
 #include <sys/mount.h>
 #include <sys/fstrans.h>
 #include <sys/namei.h>
 #include <sys/extattr.h>
 #include <sys/syscallargs.h>
 #include <sys/sysctl.h>
 #include <sys/systm.h>
 #include <sys/vfs_syscalls.h>
 #include <sys/vnode_impl.h>
 #include <miscfs/genfs/genfs.h>
 #include <miscfs/specfs/specdev.h>
 static struct vnode *vfs_vnode_iterator_next1(struct vnode_iterator *,
     bool (*)(void *, struct vnode *), void *, bool);
 /* Root filesystem. */
 vnode_t *			rootvnode;
 /* Mounted filesystem list. */
 struct mntlist			mountlist;
 kmutex_t			mountlist_lock;
 int vnode_offset_next_by_mount	/* XXX: ugly hack for pstat.c */
     = offsetof(vnode_impl_t, vi_mntvnodes.tqe_next);
 kmutex_t			mntvnode_lock;
 kmutex_t			vfs_list_lock;
 static specificdata_domain_t	mount_specificdata_domain;
 static kmutex_t			mntid_lock;
 static kmutex_t			mountgen_lock;
 static uint64_t			mountgen;
 void
 vfs_mount_sysinit(void)
+{
 	TAILQ_INIT(&mountlist);
 	mutex_init(&mountlist_lock, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mntvnode_lock, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&vfs_list_lock, MUTEX_DEFAULT, IPL_NONE);
 	mount_specificdata_domain = specificdata_domain_create();
 	mutex_init(&mntid_lock, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mountgen_lock, MUTEX_DEFAULT, IPL_NONE);
 	mountgen = 0;
+}
 struct mount *
 vfs_mountalloc(struct vfsops *vfsops, vnode_t *vp)
+{
 	struct mount *mp;
 	int error __diagused;
 	mp = kmem_zalloc(sizeof(*mp), KM_SLEEP);
 	if (mp == NULL)
 		return NULL;
 	mp->mnt_op = vfsops;
 	mp->mnt_refcnt = 1;
 	TAILQ_INIT(&mp->mnt_vnodelist);
 	mutex_init(&mp->mnt_unmounting, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mp->mnt_renamelock, MUTEX_DEFAULT, IPL_NONE);
 	mutex_init(&mp->mnt_updating, MUTEX_DEFAULT, IPL_NONE);
 	error = vfs_busy(mp, NULL);
 	KASSERT(error == 0);
 	mp->mnt_vnodecovered = vp;
 	mount_initspecific(mp);
 	mutex_enter(&mountgen_lock);
 	mp->mnt_gen = mountgen++;
 	mutex_exit(&mountgen_lock);
 	return mp;
+}
 /*
  * vfs_rootmountalloc: lookup a filesystem type, and if found allocate and
  * initialize a mount structure for it.
+ *
  * Devname is usually updated by mount(8) after booting.
  */
 int
 vfs_rootmountalloc(const char *fstypename, const char *devname,
     struct mount **mpp)
+{
 	struct vfsops *vfsp = NULL;
 	struct mount *mp;
 	mutex_enter(&vfs_list_lock);
 	LIST_FOREACH(vfsp, &vfs_list, vfs_list)
 		if (!strncmp(vfsp->vfs_name, fstypename,
 		    sizeof(mp->mnt_stat.f_fstypename)))
 			break;
 	if (vfsp == NULL) {
 		mutex_exit(&vfs_list_lock);
 		return (ENODEV);
+	}
 	vfsp->vfs_refcount++;
 	mutex_exit(&vfs_list_lock);
 	if ((mp = vfs_mountalloc(vfsp, NULL)) == NULL)
 		return ENOMEM;
 	mp->mnt_flag = MNT_RDONLY;
 	(void)strlcpy(mp->mnt_stat.f_fstypename, vfsp->vfs_name,
 	    sizeof(mp->mnt_stat.f_fstypename));
 	mp->mnt_stat.f_mntonname[0] = '/';
 	mp->mnt_stat.f_mntonname[1] = '\0';
 	mp->mnt_stat.f_mntfromname[sizeof(mp->mnt_stat.f_mntfromname) - 1] =
 	    '\0';
 	(void)copystr(devname, mp->mnt_stat.f_mntfromname,
 	    sizeof(mp->mnt_stat.f_mntfromname) - 1, 0);
 	*mpp = mp;
 	return 0;
+}
 /*
  * vfs_getnewfsid: get a new unique fsid.
  */
 void
 vfs_getnewfsid(struct mount *mp)
+{
 	static u_short xxxfs_mntid;
 	fsid_t tfsid;
 	int mtype;
 	mutex_enter(&mntid_lock);
 	mtype = makefstype(mp->mnt_op->vfs_name);
 	mp->mnt_stat.f_fsidx.__fsid_val[0] = makedev(mtype, 0);
 	mp->mnt_stat.f_fsidx.__fsid_val[1] = mtype;
 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
 	if (xxxfs_mntid == 0)
 		++xxxfs_mntid;
 	tfsid.__fsid_val[0] = makedev(mtype & 0xff, xxxfs_mntid);
 	tfsid.__fsid_val[1] = mtype;
 	if (!TAILQ_EMPTY(&mountlist)) {
 		while (vfs_getvfs(&tfsid)) {
 			tfsid.__fsid_val[0]++;
 			xxxfs_mntid++;
+		}
+	}
 	mp->mnt_stat.f_fsidx.__fsid_val[0] = tfsid.__fsid_val[0];
 	mp->mnt_stat.f_fsid = mp->mnt_stat.f_fsidx.__fsid_val[0];
 	mutex_exit(&mntid_lock);
+}
 /*
  * Lookup a mount point by filesystem identifier.
+ *
  * XXX Needs to add a reference to the mount point.
  */
 struct mount *
 vfs_getvfs(fsid_t *fsid)
+{
 	struct mount *mp;
 	mutex_enter(&mountlist_lock);
 	TAILQ_FOREACH(mp, &mountlist, mnt_list) {
 		if (mp->mnt_stat.f_fsidx.__fsid_val[0] == fsid->__fsid_val[0] &&
 		    mp->mnt_stat.f_fsidx.__fsid_val[1] == fsid->__fsid_val[1]) {
 			mutex_exit(&mountlist_lock);
 			return (mp);
+		}
+	}
 	mutex_exit(&mountlist_lock);
 	return NULL;
+}
 /*
  * Drop a reference to a mount structure, freeing if the last reference.
  */
 void
 vfs_destroy(struct mount *mp)
+{
 	if (__predict_true((int)atomic_dec_uint_nv(&mp->mnt_refcnt) > 0)) {
 		return;
+	}
 	/*
 	 * Nothing else has visibility of the mount: we can now
 	 * free the data structures.
 	 */
 	KASSERT(mp->mnt_refcnt == 0);
 	specificdata_fini(mount_specificdata_domain, &mp->mnt_specdataref);
 	mutex_destroy(&mp->mnt_unmounting);
 	mutex_destroy(&mp->mnt_updating);
 	mutex_destroy(&mp->mnt_renamelock);
 	if (mp->mnt_op != NULL) {
 		vfs_delref(mp->mnt_op);
+	}
 	kmem_free(mp, sizeof(*mp));
+}
 /*
  * Mark a mount point as busy, and gain a new reference to it.  Used to
  * prevent the file system from being unmounted during critical sections.
+ *
  * vfs_busy can be called multiple times and by multiple threads
  * and must be accompanied by the same number of vfs_unbusy calls.
+ *
  * => The caller must hold a pre-existing reference to the mount.
  * => Will fail if the file system is being unmounted, or is unmounted.
  */
 int
 vfs_busy(struct mount *mp, struct mount **nextp)
+{
 	KASSERT(mp->mnt_refcnt > 0);
 	mutex_enter(&mp->mnt_unmounting);
 	if (__predict_false((mp->mnt_iflag & IMNT_GONE) != 0)) {
 		mutex_exit(&mp->mnt_unmounting);
 		if (nextp != NULL) {
 			KASSERT(mutex_owned(&mountlist_lock));
 			*nextp = TAILQ_NEXT(mp, mnt_list);
+		}
 		return ENOENT;
+	}
 	++mp->mnt_busynest;
 	KASSERT(mp->mnt_busynest != 0);
 	mutex_exit(&mp->mnt_unmounting);
 	if (nextp != NULL) {
 		mutex_exit(&mountlist_lock);
+	}
 	atomic_inc_uint(&mp->mnt_refcnt);
 	return 0;
+}
 /*
  * Unbusy a busy filesystem.
+ *
  * Every successful vfs_busy() call must be undone by a vfs_unbusy() call.
+ *
  * => If keepref is true, preserve reference added by vfs_busy().
  * => If nextp != NULL, acquire mountlist_lock.
  */
 void
 vfs_unbusy(struct mount *mp, bool keepref, struct mount **nextp)
+{
 	KASSERT(mp->mnt_refcnt > 0);
 	if (nextp != NULL) {
 		mutex_enter(&mountlist_lock);
+	}
 	mutex_enter(&mp->mnt_unmounting);
 	KASSERT(mp->mnt_busynest != 0);
 	mp->mnt_busynest--;
 	mutex_exit(&mp->mnt_unmounting);
 	if (!keepref) {
 		vfs_destroy(mp);
+	}
 	if (nextp != NULL) {
 		KASSERT(mutex_owned(&mountlist_lock));
 		*nextp = TAILQ_NEXT(mp, mnt_list);
+	}
+}
 struct vnode_iterator {
 	vnode_impl_t vi_vnode;
 };
 void
 vfs_vnode_iterator_init(struct mount *mp, struct vnode_iterator **vnip)
+{
 	vnode_t *vp;
 	vnode_impl_t *vip;
 	vp = vnalloc_marker(mp);
 	vip = VNODE_TO_VIMPL(vp);
 	mutex_enter(&mntvnode_lock);
 	TAILQ_INSERT_HEAD(&mp->mnt_vnodelist, vip, vi_mntvnodes);
 	vp->v_usecount = 1;
 	mutex_exit(&mntvnode_lock);
 	*vnip = (struct vnode_iterator *)vip;
+}
 void
 vfs_vnode_iterator_destroy(struct vnode_iterator *vni)
+{
 	vnode_impl_t *mvip = &vni->vi_vnode;
 	vnode_t *mvp = VIMPL_TO_VNODE(mvip);
 	mutex_enter(&mntvnode_lock);
 	KASSERT(vnis_marker(mvp));
 	if (mvp->v_usecount != 0) {
 		TAILQ_REMOVE(&mvp->v_mount->mnt_vnodelist, mvip, vi_mntvnodes);
 		mvp->v_usecount = 0;
+	}
 	mutex_exit(&mntvnode_lock);
 	vnfree_marker(mvp);
+}
 static struct vnode *
 vfs_vnode_iterator_next1(struct vnode_iterator *vni,
     bool (*f)(void *, struct vnode *), void *cl, bool do_wait)
+{
 	vnode_impl_t *mvip = &vni->vi_vnode;
 	struct mount *mp = VIMPL_TO_VNODE(mvip)->v_mount;
 	vnode_t *vp;
 	vnode_impl_t *vip;
 	int error;
 	KASSERT(vnis_marker(VIMPL_TO_VNODE(mvip)));
 	do {
 		mutex_enter(&mntvnode_lock);
 		vip = TAILQ_NEXT(mvip, vi_mntvnodes);
 		TAILQ_REMOVE(&mp->mnt_vnodelist, mvip, vi_mntvnodes);
 		VIMPL_TO_VNODE(mvip)->v_usecount = 0;
 again:
 		vp = VIMPL_TO_VNODE(vip);
 		if (vp == NULL) {
 	       		mutex_exit(&mntvnode_lock);
 	       		return NULL;
+		}
 		mutex_enter(vp->v_interlock);
 		if (vnis_marker(vp) ||
 		    vdead_check(vp, (do_wait ? 0 : VDEAD_NOWAIT)) ||
 		    (f && !(*f)(cl, vp))) {
 			mutex_exit(vp->v_interlock);
 			vip = TAILQ_NEXT(vip, vi_mntvnodes);
 			goto again;
+		}
 		TAILQ_INSERT_AFTER(&mp->mnt_vnodelist, vip, mvip, vi_mntvnodes);
 		VIMPL_TO_VNODE(mvip)->v_usecount = 1;
 		mutex_exit(&mntvnode_lock);
 		error = vcache_vget(vp);
 		KASSERT(error == 0 || error == ENOENT);
 	} while (error != 0);
 	return vp;
+}
 struct vnode *
 vfs_vnode_iterator_next(struct vnode_iterator *vni,
     bool (*f)(void *, struct vnode *), void *cl)
+{
 	return vfs_vnode_iterator_next1(vni, f, cl, false);
+}
 /*
  * Move a vnode from one mount queue to another.
  */
 void
 vfs_insmntque(vnode_t *vp, struct mount *mp)
+{
 	vnode_impl_t *vip = VNODE_TO_VIMPL(vp);
 	struct mount *omp;
 	KASSERT(mp == NULL || (mp->mnt_iflag & IMNT_UNMOUNT) == 0 ||
 	    vp->v_tag == VT_VFS);
 	mutex_enter(&mntvnode_lock);
 	/*
 	 * Delete from old mount point vnode list, if on one.
 	 */
 	if ((omp = vp->v_mount) != NULL)
 		TAILQ_REMOVE(&vp->v_mount->mnt_vnodelist, vip, vi_mntvnodes);
 	/*
 	 * Insert into list of vnodes for the new mount point, if
 	 * available.  The caller must take a reference on the mount
 	 * structure and donate to the vnode.
 	 */
 	if ((vp->v_mount = mp) != NULL)
 		TAILQ_INSERT_TAIL(&mp->mnt_vnodelist, vip, vi_mntvnodes);
 	mutex_exit(&mntvnode_lock);
 	if (omp != NULL) {
 		/* Release reference to old mount. */
 		vfs_destroy(omp);
+	}
+}
 /*
  * Remove any vnodes in the vnode table belonging to mount point mp.
+ *
  * If FORCECLOSE is not specified, there should not be any active ones,
  * return error if any are found (nb: this is a user error, not a
  * system error). If FORCECLOSE is specified, detach any active vnodes
  * that are found.
+ *
  * If WRITECLOSE is set, only flush out regular file vnodes open for
  * writing.
+ *
  * SKIPSYSTEM causes any vnodes marked VV_SYSTEM to be skipped.
  */
 #ifdef DEBUG
 int busyprt = 0;	/* print out busy vnodes */
 struct ctldebug debug1 = { "busyprt", &busyprt };
 #endif
 static vnode_t *
 vflushnext(struct vnode_iterator *marker, int *when)
+{
 	if (hardclock_ticks > *when) {
 		yield();
 		*when = hardclock_ticks + hz / 10;
+	}
 	return vfs_vnode_iterator_next1(marker, NULL, NULL, true);
+}
 /*
  * Flush one vnode.  Referenced on entry, unreferenced on return.
  */
 static int
 vflush_one(vnode_t *vp, vnode_t *skipvp, int flags)
+{
 	int error;
 	struct vattr vattr;
 	if (vp == skipvp ||
 	    ((flags & SKIPSYSTEM) && (vp->v_vflag & VV_SYSTEM))) {
 		vrele(vp);
 		return 0;
+	}
 	/*
 	 * If WRITECLOSE is set, only flush out regular file
 	 * vnodes open for writing or open and unlinked.
 	 */
 	if ((flags & WRITECLOSE)) {
 		if (vp->v_type != VREG) {
 			vrele(vp);
 			return 0;
+		}
 		error = vn_lock(vp, LK_EXCLUSIVE);
 		if (error) {
 			KASSERT(error == ENOENT);
 			vrele(vp);
 			return 0;
+		}
 		error = VOP_FSYNC(vp, curlwp->l_cred, FSYNC_WAIT, 0, 0);
 		if (error == 0)
 			error = VOP_GETATTR(vp, &vattr, curlwp->l_cred);
 		VOP_UNLOCK(vp);
 		if (error) {
 			vrele(vp);
 			return error;
+		}
 		if (vp->v_writecount == 0 && vattr.va_nlink > 0) {
 			vrele(vp);
 			return 0;
+		}
+	}
 	/*
 	 * First try to recycle the vnode.
 	 */
 	if (vrecycle(vp))
 		return 0;
 	/*
 	 * If FORCECLOSE is set, forcibly close the vnode.
 	 */
 	if (flags & FORCECLOSE) {
 		vgone(vp);
 		return 0;
+	}
 	vrele(vp);
 	return EBUSY;
+}
 int
 vflush(struct mount *mp, vnode_t *skipvp, int flags)
+{
 	vnode_t *vp;
 	struct vnode_iterator *marker;
 	int busy, error, when, retries = 2;
 	do {
 		busy = error = when = 0;
 		/*
 		 * First, flush out any vnode references from the
 		 * deferred vrele list.
 		 */
 		vfs_drainvnodes();
 		vfs_vnode_iterator_init(mp, &marker);
 		while ((vp = vflushnext(marker, &when)) != NULL) {
 			error = vflush_one(vp, skipvp, flags);
 			if (error == EBUSY) {
 				error = 0;
 				busy++;
 #ifdef DEBUG
 				if (busyprt && retries == 0)
 					vprint("vflush: busy vnode", vp);
 #endif
 			} else if (error != 0) {
 				break;
+			}
+		}
 		vfs_vnode_iterator_destroy(marker);
 	} while (error == 0 && busy > 0 && retries-- > 0);
 	if (error)
 		return error;
 	if (busy)
 		return EBUSY;
 	return 0;
+}
 /*
  * Mount a file system.
  */
 /*
  * Scan all active processes to see if any of them have a current or root
  * directory onto which the new filesystem has just been  mounted. If so,
  * replace them with the new mount point.
  */
 static void
 mount_checkdirs(vnode_t *olddp)
+{
 	vnode_t *newdp, *rele1, *rele2;
 	struct cwdinfo *cwdi;
 	struct proc *p;
 	bool retry;
 	if (olddp->v_usecount == 1) {
 		return;
+	}
 	if (VFS_ROOT(olddp->v_mountedhere, &newdp))
 		panic("mount: lost mount");
 	do {
 		retry = false;
 		mutex_enter(proc_lock);
 		PROCLIST_FOREACH(p, &allproc) {
 			if ((cwdi = p->p_cwdi) == NULL)
 				continue;
 			/*
 			 * Cannot change to the old directory any more,
 			 * so even if we see a stale value it is not a
 			 * problem.
 			 */
 			if (cwdi->cwdi_cdir != olddp &&
 			    cwdi->cwdi_rdir != olddp)
 				continue;
 			retry = true;
 			rele1 = NULL;
 			rele2 = NULL;
 			atomic_inc_uint(&cwdi->cwdi_refcnt);
 			mutex_exit(proc_lock);
 			rw_enter(&cwdi->cwdi_lock, RW_WRITER);
 			if (cwdi->cwdi_cdir == olddp) {
 				rele1 = cwdi->cwdi_cdir;
 				vref(newdp);
 				cwdi->cwdi_cdir = newdp;
+			}
 			if (cwdi->cwdi_rdir == olddp) {
 				rele2 = cwdi->cwdi_rdir;
 				vref(newdp);
 				cwdi->cwdi_rdir = newdp;
+			}
 			rw_exit(&cwdi->cwdi_lock);
 			cwdfree(cwdi);
 			if (rele1 != NULL)
 				vrele(rele1);
 			if (rele2 != NULL)
 				vrele(rele2);
 			mutex_enter(proc_lock);
 			break;
+		}
 		mutex_exit(proc_lock);
 	} while (retry);
 	if (rootvnode == olddp) {
 		vrele(rootvnode);
 		vref(newdp);
 		rootvnode = newdp;
+	}
 	vput(newdp);
+}
 /*
  * Start extended attributes
  */
 static int
 start_extattr(struct mount *mp)
+{
 	int error;
 	error = VFS_EXTATTRCTL(mp, EXTATTR_CMD_START, NULL, 0, NULL);
 	if (error)
 		printf("%s: failed to start extattr: error = %d\n",
 		       mp->mnt_stat.f_mntonname, error);
 	return error;
+}
 int
 mount_domount(struct lwp *l, vnode_t **vpp, struct vfsops *vfsops,
     const char *path, int flags, void *data, size_t *data_len)
+{
 	vnode_t *vp = *vpp;
 	struct mount *mp;
 	struct pathbuf *pb;
 	struct nameidata nd;
 	int error;
 	error = kauth_authorize_system(l->l_cred, KAUTH_SYSTEM_MOUNT,
 	    KAUTH_REQ_SYSTEM_MOUNT_NEW, vp, KAUTH_ARG(flags), data);
 	if (error) {
 		vfs_delref(vfsops);
 		return error;
+	}
 	/* Cannot make a non-dir a mount-point (from here anyway). */
 	if (vp->v_type != VDIR) {
 		vfs_delref(vfsops);
 		return ENOTDIR;
+	}
 	if (flags & MNT_EXPORTED) {
 		vfs_delref(vfsops);
 		return EINVAL;
+	}
 	if ((mp = vfs_mountalloc(vfsops, vp)) == NULL) {
 		vfs_delref(vfsops);
 		return ENOMEM;
+	}
 	if ((error = fstrans_mount(mp)) != 0) {
 		vfs_unbusy(mp, false, NULL);
 		vfs_destroy(mp);
 		return error;
+	}
 	mp->mnt_stat.f_owner = kauth_cred_geteuid(l->l_cred);
 	/*
 	 * The underlying file system may refuse the mount for
 	 * various reasons.  Allow the user to force it to happen.
+	 *
 	 * Set the mount level flags.
 	 */
 	mp->mnt_flag = flags & (MNT_BASIC_FLAGS | MNT_FORCE | MNT_IGNORE);
 	mutex_enter(&mp->mnt_updating);
 	error = VFS_MOUNT(mp, path, data, data_len);
 	mp->mnt_flag &= ~MNT_OP_FLAGS;
 	if (error != 0)
 		goto err_unmounted;
 	/*
 	 * Validate and prepare the mount point.
 	 */
 	error = pathbuf_copyin(path, &pb);
 	if (error != 0) {
 		goto err_mounted;
+	}
 	NDINIT(&nd, LOOKUP, FOLLOW | LOCKLEAF | TRYEMULROOT, pb);
 	error = namei(&nd);
 	pathbuf_destroy(pb);
 	if (error != 0) {
 		goto err_mounted;
+	}
 	if (nd.ni_vp != vp) {
 		vput(nd.ni_vp);
 		error = EINVAL;
 		goto err_mounted;
+	}
 	if (vp->v_mountedhere != NULL) {
 		vput(nd.ni_vp);
 		error = EBUSY;
 		goto err_mounted;
+	}
 	error = vinvalbuf(vp, V_SAVE, l->l_cred, l, 0, 0);
 	if (error != 0) {
 		vput(nd.ni_vp);
 		goto err_mounted;
+	}
 	/*
 	 * Put the new filesystem on the mount list after root.
 	 */
 	cache_purge(vp);
 	mp->mnt_iflag &= ~IMNT_WANTRDWR;
 	mutex_enter(&mountlist_lock);
 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 	mutex_exit(&mountlist_lock);
 	if ((mp->mnt_flag & (MNT_RDONLY | MNT_ASYNC)) == 0)
 		vfs_syncer_add_to_worklist(mp);
 	vp->v_mountedhere = mp;
 	vput(nd.ni_vp);
 	mount_checkdirs(vp);
 	mutex_exit(&mp->mnt_updating);
 	/* Hold an additional reference to the mount across VFS_START(). */
 	vfs_unbusy(mp, true, NULL);
 	(void) VFS_STATVFS(mp, &mp->mnt_stat);
 	error = VFS_START(mp, 0);
        if (error) {
 		vrele(vp);
 	} else if (flags & MNT_EXTATTR) {
 		(void)start_extattr(mp);
+	}
 	/* Drop reference held for VFS_START(). */
 	vfs_destroy(mp);
 	*vpp = NULL;
 	return error;
 err_mounted:
 	if (VFS_UNMOUNT(mp, MNT_FORCE) != 0)
 		panic("Unmounting fresh file system failed");
 err_unmounted:
 	vp->v_mountedhere = NULL;
 	mutex_exit(&mp->mnt_updating);
 	fstrans_unmount(mp);
 	vfs_unbusy(mp, false, NULL);
 	vfs_destroy(mp);
 	return error;
+}
 /*
  * Do the actual file system unmount.  File system is assumed to have
  * been locked by the caller.
+ *
  * => Caller hold reference to the mount, explicitly for dounmount().
  */
 int
 dounmount(struct mount *mp, int flags, struct lwp *l)
+{
 	struct mount *cmp;
 	vnode_t *coveredvp;
 	int error, async, used_syncer, used_extattr;
 #if NVERIEXEC > 0
 	error = veriexec_unmountchk(mp);
 	if (error)
 		return (error);
 #endif /* NVERIEXEC > 0 */
 	/*
 	 * No unmount below layered mounts.
 	 */
 	mutex_enter(&mountlist_lock);
 	TAILQ_FOREACH(cmp, &mountlist, mnt_list) {
 		if (cmp->mnt_lower == mp) {
 			mutex_exit(&mountlist_lock);
 			return EBUSY;
+		}
+	}
 	mutex_exit(&mountlist_lock);
 	/*
 	 * XXX Freeze syncer.  Must do this before locking the
 	 * mount point.  See dounmount() for details.
 	 */
 	mutex_enter(&syncer_mutex);
 	/*
 	 * Abort unmount attempt when the filesystem is in use
 	 */
 	mutex_enter(&mp->mnt_unmounting);
 	if (mp->mnt_busynest != 0) {
 		mutex_exit(&mp->mnt_unmounting);
 		mutex_exit(&syncer_mutex);
 		return EBUSY;
+	}
 	/*
 	 * Abort unmount attempt when the filesystem is not mounted
 	 */
 	if ((mp->mnt_iflag & IMNT_GONE) != 0) {
 		mutex_exit(&mp->mnt_unmounting);
 		mutex_exit(&syncer_mutex);
 		return ENOENT;
+	}
 	used_syncer = (mp->mnt_iflag & IMNT_ONWORKLIST) != 0;
 	used_extattr = mp->mnt_flag & MNT_EXTATTR;
 	/*
 	 * XXX Syncer must be frozen when we get here.  This should really
 	 * be done on a per-mountpoint basis, but the syncer doesn't work
 	 * like that.
+	 *
 	 * The caller of dounmount() must acquire syncer_mutex because
 	 * the syncer itself acquires locks in syncer_mutex -> vfs_busy
 	 * order, and we must preserve that order to avoid deadlock.
+	 *
 	 * So, if the file system did not use the syncer, now is
 	 * the time to release the syncer_mutex.
 	 */
 	if (used_syncer == 0) {
 		mutex_exit(&syncer_mutex);
+	}
 	mp->mnt_iflag |= IMNT_UNMOUNT;
 	mutex_enter(&mp->mnt_updating);
 	async = mp->mnt_flag & MNT_ASYNC;
 	mp->mnt_flag &= ~MNT_ASYNC;
 	cache_purgevfs(mp);	/* remove cache entries for this file sys */
 	if (used_syncer)
 		vfs_syncer_remove_from_worklist(mp);
 	error = 0;
 	if (((mp->mnt_flag & MNT_RDONLY) == 0) && ((flags & MNT_FORCE) == 0)) {
 		error = VFS_SYNC(mp, MNT_WAIT, l->l_cred);
+	}
 	if (error == 0 || (flags & MNT_FORCE)) {
 		error = VFS_UNMOUNT(mp, flags);
+	}
 	if (error) {
 		mp->mnt_iflag &= ~IMNT_UNMOUNT;
 		mutex_exit(&mp->mnt_unmounting);
 		if ((mp->mnt_flag & (MNT_RDONLY | MNT_ASYNC)) == 0)
 			vfs_syncer_add_to_worklist(mp);
 		mp->mnt_flag |= async;
 		mutex_exit(&mp->mnt_updating);
 		if (used_syncer)
 			mutex_exit(&syncer_mutex);
 		if (used_extattr) {
 			if (start_extattr(mp) != 0)
 				mp->mnt_flag &= ~MNT_EXTATTR;
 			else
 				mp->mnt_flag |= MNT_EXTATTR;
+		}
 		return (error);
+	}
 	mutex_exit(&mp->mnt_updating);
 	/*
 	 * release mnt_umounting lock here, because other code calls
 	 * vfs_busy() while holding the mountlist_lock.
+	 *
 	 * mark filesystem as gone to prevent further umounts
 	 * after mnt_umounting lock is gone, this also prevents
 	 * vfs_busy() from succeeding.
 	 */
 	mp->mnt_iflag |= IMNT_GONE;
 	mutex_exit(&mp->mnt_unmounting);
 	if ((coveredvp = mp->mnt_vnodecovered) != NULLVP) {
 		vn_lock(coveredvp, LK_EXCLUSIVE | LK_RETRY);
 		coveredvp->v_mountedhere = NULL;
 		VOP_UNLOCK(coveredvp);
+	}
 	mutex_enter(&mountlist_lock);
 	TAILQ_REMOVE(&mountlist, mp, mnt_list);
 	mutex_exit(&mountlist_lock);
 	if (TAILQ_FIRST(&mp->mnt_vnodelist) != NULL)
 		panic("unmount: dangling vnode");
 	if (used_syncer)
 		mutex_exit(&syncer_mutex);
 	vfs_hooks_unmount(mp);
 	fstrans_unmount(mp);
 	vfs_destroy(mp);	/* reference from mount() */
 	if (coveredvp != NULLVP) {
 		vrele(coveredvp);
+	}
 	return (0);
+}
 /*
  * Unmount all file systems.
  * We traverse the list in reverse order under the assumption that doing so
  * will avoid needing to worry about dependencies.
  */
 bool
 vfs_unmountall(struct lwp *l)
+{
 	printf("unmounting file systems...\n");
 	return vfs_unmountall1(l, true, true);
+}
 static void
 vfs_unmount_print(struct mount *mp, const char *pfx)
+{
 	aprint_verbose("%sunmounted %s on %s type %s\n", pfx,
 	    mp->mnt_stat.f_mntfromname, mp->mnt_stat.f_mntonname,
 	    mp->mnt_stat.f_fstypename);
+}
 bool
 vfs_unmount_forceone(struct lwp *l)
+{
 	struct mount *mp, *nmp;
 	int error;
 	nmp = NULL;
 	TAILQ_FOREACH_REVERSE(mp, &mountlist, mntlist, mnt_list) {
 		if (nmp == NULL || mp->mnt_gen > nmp->mnt_gen) {
 			nmp = mp;
+		}
+	}
 	if (nmp == NULL) {
 		return false;
+	}
 #ifdef DEBUG
 	printf("forcefully unmounting %s (%s)...\n",
 	    nmp->mnt_stat.f_mntonname, nmp->mnt_stat.f_mntfromname);
 #endif
 	atomic_inc_uint(&nmp->mnt_refcnt);
 	if ((error = dounmount(nmp, MNT_FORCE, l)) == 0) {
 		vfs_unmount_print(nmp, "forcefully ");
 		return true;
 	} else {
 		vfs_destroy(nmp);
+	}
 #ifdef DEBUG
 	printf("forceful unmount of %s failed with error %d\n",
 	    nmp->mnt_stat.f_mntonname, error);
 #endif
 	return false;
+}
 bool
 vfs_unmountall1(struct lwp *l, bool force, bool verbose)
+{
 	struct mount *mp, *nmp;
 	bool any_error = false, progress = false;
 	int error;
 	TAILQ_FOREACH_REVERSE_SAFE(mp, &mountlist, mntlist, mnt_list, nmp) {
 #ifdef DEBUG
 		printf("unmounting %p %s (%s)...\n",
 		    (void *)mp, mp->mnt_stat.f_mntonname,
 		    mp->mnt_stat.f_mntfromname);
 #endif
 		atomic_inc_uint(&mp->mnt_refcnt);
 		if ((error = dounmount(mp, force ? MNT_FORCE : 0, l)) == 0) {
 			vfs_unmount_print(mp, "");
 			progress = true;
 		} else {
 			vfs_destroy(mp);
 			if (verbose) {
 				printf("unmount of %s failed with error %d\n",
 				    mp->mnt_stat.f_mntonname, error);
+			}
 			any_error = true;
+		}
+	}
 	if (verbose) {
 		printf("unmounting done\n");
+	}
 	if (any_error && verbose) {
 		printf("WARNING: some file systems would not unmount\n");
+	}
 	return progress;
+}
 void
 vfs_sync_all(struct lwp *l)
+{
 	printf("syncing disks... ");
 	/* remove user processes from run queue */
 	suspendsched();
 	(void)spl0();
 	/* avoid coming back this way again if we panic. */
 	doing_shutdown = 1;
 	do_sys_sync(l);
 	/* Wait for sync to finish. */
 	if (buf_syncwait() != 0) {
 #if defined(DDB) && defined(DEBUG_HALT_BUSY)
 		Debugger();
 #endif
 		printf("giving up\n");
 		return;
 	} else
 		printf("done\n");
+}
 /*
  * Sync and unmount file systems before shutting down.
  */
 void
 vfs_shutdown(void)
+{
 	lwp_t *l = curlwp;
 	vfs_sync_all(l);
 	/*
 	 * If we have paniced - do not make the situation potentially
 	 * worse by unmounting the file systems.
 	 */
 	if (panicstr != NULL) {
 		return;
+	}
 	/* Unmount file systems. */
 	vfs_unmountall(l);
+}
 /*
  * Print a list of supported file system types (used by vfs_mountroot)
  */
 static void
 vfs_print_fstypes(void)
+{
 	struct vfsops *v;
 	int cnt = 0;
 	mutex_enter(&vfs_list_lock);
 	LIST_FOREACH(v, &vfs_list, vfs_list)
 		++cnt;
 	mutex_exit(&vfs_list_lock);
 	if (cnt == 0) {
 		printf("WARNING: No file system modules have been loaded.\n");
 		return;
+	}
 	printf("Supported file systems:");
 	mutex_enter(&vfs_list_lock);
 	LIST_FOREACH(v, &vfs_list, vfs_list) {
 		printf(" %s", v->vfs_name);
+	}
 	mutex_exit(&vfs_list_lock);
 	printf("\n");
+}
 /*
  * Mount the root file system.  If the operator didn't specify a
  * file system to use, try all possible file systems until one
  * succeeds.
  */
 int
 vfs_mountroot(void)
+{
 	struct vfsops *v;
 	int error = ENODEV;
 	if (root_device == NULL)
 		panic("vfs_mountroot: root device unknown");
 	switch (device_class(root_device)) {
 	case DV_IFNET:
 		if (rootdev != NODEV)
 			panic("vfs_mountroot: rootdev set for DV_IFNET "
 			    "(0x%llx -> %llu,%llu)",
 			    (unsigned long long)rootdev,
 			    (unsigned long long)major(rootdev),
 			    (unsigned long long)minor(rootdev));
 		break;
 	case DV_DISK:
 		if (rootdev == NODEV)
 			panic("vfs_mountroot: rootdev not set for DV_DISK");
 	        if (bdevvp(rootdev, &rootvp))
 	                panic("vfs_mountroot: can't get vnode for rootdev");
 		error = VOP_OPEN(rootvp, FREAD, FSCRED);
 		if (error) {
 			printf("vfs_mountroot: can't open root device\n");
 			return (error);
+		}
 		break;
 	case DV_VIRTUAL:
 		break;
 	default:
 		printf("%s: inappropriate for root file system\n",
 		    device_xname(root_device));
 		return (ENODEV);
+	}
 	/*
 	 * If user specified a root fs type, use it.  Make sure the
 	 * specified type exists and has a mount_root()
 	 */
 	if (strcmp(rootfstype, ROOT_FSTYPE_ANY) != 0) {
 		v = vfs_getopsbyname(rootfstype);
 		error = EFTYPE;
 		if (v != NULL) {
 			if (v->vfs_mountroot != NULL) {
 				error = (v->vfs_mountroot)();
+			}
 			v->vfs_refcount--;
+		}
 		goto done;
+	}
 	/*
 	 * Try each file system currently configured into the kernel.
 	 */
 	mutex_enter(&vfs_list_lock);
 	LIST_FOREACH(v, &vfs_list, vfs_list) {
 		if (v->vfs_mountroot == NULL)
 			continue;
 #ifdef DEBUG
 		aprint_normal("mountroot: trying %s...\n", v->vfs_name);
 #endif
 		v->vfs_refcount++;
 		mutex_exit(&vfs_list_lock);
 		error = (*v->vfs_mountroot)();
 		mutex_enter(&vfs_list_lock);
 		v->vfs_refcount--;
 		if (!error) {
 			aprint_normal("root file system type: %s\n",
 			    v->vfs_name);
 			break;
+		}
+	}
 	mutex_exit(&vfs_list_lock);
 	if (v == NULL) {
 		vfs_print_fstypes();
 		printf("no file system for %s", device_xname(root_device));
 		if (device_class(root_device) == DV_DISK)
 			printf(" (dev 0x%llx)", (unsigned long long)rootdev);
 		printf("\n");
 		error = EFTYPE;
+	}
 done:
 	if (error && device_class(root_device) == DV_DISK) {
 		VOP_CLOSE(rootvp, FREAD, FSCRED);
 		vrele(rootvp);
+	}
 	if (error == 0) {
 		struct mount *mp;
 		extern struct cwdinfo cwdi0;
 		mp = TAILQ_FIRST(&mountlist);
 		mp->mnt_flag |= MNT_ROOTFS;
 		mp->mnt_op->vfs_refcount++;
 		error = fstrans_mount(mp);
 		KASSERT(error == 0);
 		/*
 		 * Get the vnode for '/'.  Set cwdi0.cwdi_cdir to
 		 * reference it.
 		 */
 		error = VFS_ROOT(mp, &rootvnode);
 		if (error)
 			panic("cannot find root vnode, error=%d", error);
 		cwdi0.cwdi_cdir = rootvnode;
 		vref(cwdi0.cwdi_cdir);
 		VOP_UNLOCK(rootvnode);
 		cwdi0.cwdi_rdir = NULL;
 		/*
 		 * Now that root is mounted, we can fixup initproc's CWD
 		 * info.  All other processes are kthreads, which merely
 		 * share proc0's CWD info.
 		 */
 		initproc->p_cwdi->cwdi_cdir = rootvnode;
 		vref(initproc->p_cwdi->cwdi_cdir);
 		initproc->p_cwdi->cwdi_rdir = NULL;
 		/*
 		 * Enable loading of modules from the filesystem
 		 */
 		module_load_vfs_init();
+	}
 	return (error);
+}
 /*
  * mount_specific_key_create --
  *	Create a key for subsystem mount-specific data.
  */
 int
 mount_specific_key_create(specificdata_key_t *keyp, specificdata_dtor_t dtor)
+{
 	return specificdata_key_create(mount_specificdata_domain, keyp, dtor);
+}
 /*
  * mount_specific_key_delete --
  *	Delete a key for subsystem mount-specific data.
  */
 void
 mount_specific_key_delete(specificdata_key_t key)
+{
 	specificdata_key_delete(mount_specificdata_domain, key);
+}
 /*
  * mount_initspecific --
  *	Initialize a mount's specificdata container.
  */
 void
 mount_initspecific(struct mount *mp)
+{
 	int error __diagused;
 	error = specificdata_init(mount_specificdata_domain,
 				  &mp->mnt_specdataref);
 	KASSERT(error == 0);
+}
 /*
  * mount_finispecific --
  *	Finalize a mount's specificdata container.
  */
 void
 mount_finispecific(struct mount *mp)
+{
 	specificdata_fini(mount_specificdata_domain, &mp->mnt_specdataref);
+}
 /*
  * mount_getspecific --
  *	Return mount-specific data corresponding to the specified key.
  */
 void *
 mount_getspecific(struct mount *mp, specificdata_key_t key)
+{
 	return specificdata_getspecific(mount_specificdata_domain,
 					 &mp->mnt_specdataref, key);
+}
 /*
  * mount_setspecific --
  *	Set mount-specific data corresponding to the specified key.
  */
 void
 mount_setspecific(struct mount *mp, specificdata_key_t key, void *data)
+{
 	specificdata_setspecific(mount_specificdata_domain,
 				 &mp->mnt_specdataref, key, data);
+}
 /*
  * Check to see if a filesystem is mounted on a block device.
  */
 int
 vfs_mountedon(vnode_t *vp)
+{
 	vnode_t *vq;
 	int error = 0;
 	if (vp->v_type != VBLK)
 		return ENOTBLK;
 	if (spec_node_getmountedfs(vp) != NULL)
 		return EBUSY;
 	if (spec_node_lookup_by_dev(vp->v_type, vp->v_rdev, &vq) == 0) {
 		if (spec_node_getmountedfs(vq) != NULL)
 			error = EBUSY;
 		vrele(vq);
+	}
 	return error;
+}
 /*
  * Check if a device pointed to by vp is mounted.
+ *
  * Returns:
  *   EINVAL	if it's not a disk
  *   EBUSY	if it's a disk and mounted
  *   0		if it's a disk and not mounted
  */
 int
 rawdev_mounted(vnode_t *vp, vnode_t **bvpp)
+{
 	vnode_t *bvp;
 	dev_t dev;
 	int d_type;
 	bvp = NULL;
 	d_type = D_OTHER;
 	if (iskmemvp(vp))
 		return EINVAL;
 	switch (vp->v_type) {
 	case VCHR: {
 		const struct cdevsw *cdev;
 		dev = vp->v_rdev;
 		cdev = cdevsw_lookup(dev);
 		if (cdev != NULL) {
 			dev_t blkdev;
 			blkdev = devsw_chr2blk(dev);
 			if (blkdev != NODEV) {
 				if (vfinddev(blkdev, VBLK, &bvp) != 0) {
 					d_type = (cdev->d_flag & D_TYPEMASK);
 					/* XXX: what if bvp disappears? */
 					vrele(bvp);
+				}
+			}
+		}
 		break;
+		}
 	case VBLK: {
 		const struct bdevsw *bdev;
 		dev = vp->v_rdev;
 		bdev = bdevsw_lookup(dev);
 		if (bdev != NULL)
 			d_type = (bdev->d_flag & D_TYPEMASK);
 		bvp = vp;
 		break;
+		}
 	default:
 		break;
+	}
 	if (d_type != D_DISK)
 		return EINVAL;
 	if (bvpp != NULL)
 		*bvpp = bvp;
 	/*
 	 * XXX: This is bogus. We should be failing the request
 	 * XXX: not only if this specific slice is mounted, but
 	 * XXX: if it's on a disk with any other mounted slice.
 	 */
 	if (vfs_mountedon(bvp))
 		return EBUSY;
 	return 0;
+}
 /*
  * Make a 'unique' number from a mount type name.
  */
 long
 makefstype(const char *type)
+{
 	long rv;
 	for (rv = 0; *type; type++) {
 		rv <<= 2;
 		rv ^= *type;
+	}
 	return rv;
+}
 void
 mountlist_append(struct mount *mp)
+{
 	mutex_enter(&mountlist_lock);
 	TAILQ_INSERT_TAIL(&mountlist, mp, mnt_list);
 	mutex_exit(&mountlist_lock);
+}