xref: /dflybsd-src/sys/vfs/devfs/devfs_core.c (revision 6507240b2fcfebaacc0f92f997dad76922e1d8c0)

/*
 * Copyright (c) 2009 The DragonFly Project.  All rights reserved.
 *
 * This code is derived from software contributed to The DragonFly Project
 * by Alex Hornung <ahornung@gmail.com>
 *
 * 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 DragonFly Project 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 COPYRIGHT HOLDERS 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
 * COPYRIGHT HOLDERS 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.
 */
#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/mount.h>
#include <sys/vnode.h>
#include <sys/types.h>
#include <sys/lock.h>
#include <sys/msgport.h>
#include <sys/msgport2.h>
#include <sys/spinlock2.h>
#include <sys/sysctl.h>
#include <sys/ucred.h>
#include <sys/param.h>
#include <sys/sysref2.h>
#include <sys/systm.h>
#include <vfs/devfs/devfs.h>
#include <vfs/devfs/devfs_rules.h>

MALLOC_DEFINE(M_DEVFS, "devfs", "Device File System (devfs) allocations");
DEVFS_DECLARE_CLONE_BITMAP(ops_id);
/*
 * SYSREF Integration - reference counting, allocation,
 * sysid and syslink integration.
 */
static void devfs_cdev_terminate(cdev_t dev);
static struct sysref_class     cdev_sysref_class = {
	.name =         "cdev",
	.mtype =        M_DEVFS,
	.proto =        SYSREF_PROTO_DEV,
	.offset =       offsetof(struct cdev, si_sysref),
	.objsize =      sizeof(struct cdev),
	.mag_capacity = 32,
	.flags =        0,
	.ops =  {
		.terminate = (sysref_terminate_func_t)devfs_cdev_terminate
	}
};

static struct objcache	*devfs_node_cache;
static struct objcache 	*devfs_msg_cache;
static struct objcache	*devfs_dev_cache;

static struct objcache_malloc_args devfs_node_malloc_args = {
	sizeof(struct devfs_node), M_DEVFS };
struct objcache_malloc_args devfs_msg_malloc_args = {
	sizeof(struct devfs_msg), M_DEVFS };
struct objcache_malloc_args devfs_dev_malloc_args = {
	sizeof(struct cdev), M_DEVFS };

static struct devfs_dev_head devfs_dev_list = TAILQ_HEAD_INITIALIZER(devfs_dev_list);
static struct devfs_mnt_head devfs_mnt_list = TAILQ_HEAD_INITIALIZER(devfs_mnt_list);
static struct devfs_chandler_head devfs_chandler_list = TAILQ_HEAD_INITIALIZER(devfs_chandler_list);
static struct devfs_alias_head devfs_alias_list = TAILQ_HEAD_INITIALIZER(devfs_alias_list);

struct lock 		devfs_lock;
static struct lwkt_port devfs_dispose_port;
static struct lwkt_port devfs_msg_port;
static struct thread 	*td_core;

static ino_t 	d_ino = 0;
static __uint32_t	msg_id = 0;
static struct spinlock  ino_lock;
static int devfs_debug_enable = 0;

static ino_t devfs_fetch_ino(void);
static int devfs_gc_dirs(struct devfs_node *);
static int devfs_gc_links(struct devfs_node *, struct devfs_node *, size_t);
static int devfs_create_all_dev_worker(struct devfs_node *);
static int devfs_create_dev_worker(cdev_t, uid_t, gid_t, int);
static int devfs_destroy_dev_worker(cdev_t);
static int devfs_destroy_subnames_worker(char *);
static int devfs_destroy_dev_by_ops_worker(struct dev_ops *, int);
static int devfs_propagate_dev(cdev_t, int);
static int devfs_unlink_dev(cdev_t dev);

static int devfs_chandler_add_worker(char *, d_clone_t *);
static int devfs_chandler_del_worker(char *);

static void devfs_msg_autofree_reply(lwkt_port_t, lwkt_msg_t);
static void devfs_msg_core(void *);

static int devfs_find_device_by_name_worker(devfs_msg_t);
static int devfs_find_device_by_udev_worker(devfs_msg_t);

static int devfs_apply_reset_rules_caller(char *, int);
static int devfs_apply_reset_rules_worker(struct devfs_node *, int);

static int devfs_scan_callback_worker(devfs_scan_t *);

static struct devfs_node *devfs_resolve_or_create_dir(struct devfs_node *, char *, size_t, int);

static int devfs_make_alias_worker(struct devfs_alias *);
static int devfs_alias_remove(cdev_t);
static int devfs_alias_reap(void);
static int devfs_alias_propagate(struct devfs_alias *);
static int devfs_alias_apply(struct devfs_node *, struct devfs_alias *);
static int devfs_alias_check_create(struct devfs_node *);

static int devfs_clr_subnames_flag_worker(char *, uint32_t);
static int devfs_destroy_subnames_without_flag_worker(char *, uint32_t);

/*
 * devfs_debug() is a SYSCTL and TUNABLE controlled debug output function using kvprintf
 */
int
devfs_debug(int level, char *fmt, ...)
{
	__va_list ap;

	__va_start(ap, fmt);
	if (level <= devfs_debug_enable)
		kvprintf(fmt, ap);
	__va_end(ap);

	return 0;
}

/*
 * devfs_allocp() Allocates a new devfs node with the specified
 * parameters. The node is also automatically linked into the topology
 * if a parent is specified. It also calls the rule and alias stuff to
 * be applied on the new node
 */
struct devfs_node *
devfs_allocp(devfs_nodetype devfsnodetype, char *name,
	     struct devfs_node *parent, struct mount *mp, cdev_t dev)
{
	struct devfs_node *node = NULL;
	size_t namlen = strlen(name);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocp -1- for %s\n", name?name:"NULL");

	node = objcache_get(devfs_node_cache, M_WAITOK);

	bzero(node, sizeof(*node));

	atomic_add_int(&(DEVFS_MNTDATA(mp)->leak_count), 1);

	node->d_dev = NULL;
	node->nchildren = 1;
	node->mp = mp;
	node->d_dir.d_ino = devfs_fetch_ino();
	node->cookie_jar = 2; /* Leave 0 and 1 for '.' and '..', respectively */

	/* Access Control members */
	node->mode = DEVFS_DEFAULT_MODE;	/* files access mode and type */
	node->uid = DEVFS_DEFAULT_UID;		/* owner user id */
	node->gid = DEVFS_DEFAULT_GID;		/* owner group id */

	switch (devfsnodetype) {
	case Proot:
		/* Ensure that we don't recycle the root vnode */
		node->flags |= DEVFS_NODE_LINKED;
	case Pdir:
		TAILQ_INIT(DEVFS_DENODE_HEAD(node));
		node->d_dir.d_type = DT_DIR;
		node->nchildren = 2;
		break;

	case Plink:
		node->d_dir.d_type = DT_LNK;
		break;

	case Preg:
		node->d_dir.d_type = DT_REG;
		break;

	case Pdev:
		if (dev != NULL) {
			node->d_dir.d_type = DT_CHR;
			node->d_dev = dev;
			node->d_dir.d_ino = dev->si_inode;

			node->mode = dev->si_perms;	/* files access mode and type */
			node->uid = dev->si_uid;		/* owner user id */
			node->gid = dev->si_gid;		/* owner group id */

			devfs_alias_check_create(node);
		}
		break;

	default:
		panic("devfs_allocp: unknown node type");
	}

	node->v_node = NULL;
	node->node_type = devfsnodetype;

	/* Init the dirent structure of each devfs vnode */
	KKASSERT(namlen < 256);

	node->d_dir.d_namlen = namlen;
	node->d_dir.d_name = kmalloc(namlen+1, M_DEVFS, M_WAITOK);
	memcpy(node->d_dir.d_name, name, namlen);
	node->d_dir.d_name[namlen] = '\0';

	/* Initialize the parent node element */
	node->parent = parent;

	/* Apply rules */
	devfs_rule_check_apply(node);

	/* xtime members */
	nanotime(&node->atime);
	node->mtime = node->ctime = node->atime;

	/*
	 * Associate with parent as last step, clean out namecache
	 * reference.
	 */
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocp: about to insert node\n");
	if ((parent != NULL) &&
	    ((parent->node_type == Proot) || (parent->node_type == Pdir))) {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "devfs_allocp: node inserted %p\n",
			    node);
		parent->nchildren++;
		node->cookie = parent->cookie_jar++;
		node->flags |= DEVFS_NODE_LINKED;
		TAILQ_INSERT_TAIL(DEVFS_DENODE_HEAD(parent), node, link);

		/* This forces negative namecache lookups to clear */
		++mp->mnt_namecache_gen;
	}

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocp -end:2-\n");
	return node;
}

/*
 * devfs_allocv() allocates a new vnode based on a devfs node.
 */
int
devfs_allocv(struct vnode **vpp, struct devfs_node *node)
{
	struct vnode *vp;
	int error = 0;

	KKASSERT(node);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -1-\n");

try_again:
	while ((vp = node->v_node) != NULL) {
		error = vget(vp, LK_EXCLUSIVE);
		if (error != ENOENT) {
			*vpp = vp;
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv, code path 2...\n");
			goto out;
		}
	}
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -3-\n");

	if ((error = getnewvnode(VT_DEVFS, node->mp, vpp, 0, 0)) != 0)
		goto out;

	vp = *vpp;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -4-\n");

	if (node->v_node != NULL) {
		vp->v_type = VBAD;
		vx_put(vp);
		goto try_again;
	}

	vp->v_data = node;
	node->v_node = vp;
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -5-\n");

	switch (node->node_type) {
	case Proot:
		vp->v_flag |= VROOT;
	case Pdir:
		vp->v_type = VDIR;
		break;

	case Plink:
		vp->v_type = VLNK;
		break;

	case Preg:
		vp->v_type = VREG;
		break;

	case Pdev:
		vp->v_type = VCHR;
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -6-\n");
		KKASSERT(node->d_dev);

		if (node->d_dev) {
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -7-\n");
			vp->v_uminor = node->d_dev->si_uminor;
			vp->v_umajor = 0;
#if 0
			vp->v_rdev = node->d_dev;
#endif
			v_associate_rdev(vp, node->d_dev);
			vp->v_ops = &node->mp->mnt_vn_spec_ops;
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -8-\n");
		} else {
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv: type is Pdev but d_dev is not set!!!!\n");
		}
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -9-\n");
		break;

	default:
		panic("devfs_allocv: unknown node type");
	}

out:
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -10-\n");
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocv -end:11-\n");
	return error;
}

/*
 * devfs_allocvp allocates both a devfs node (with the given settings) and a vnode
 * based on the newly created devfs node.
 */
int
devfs_allocvp(struct mount *mp, struct vnode **vpp, devfs_nodetype devfsnodetype,
				char *name, struct devfs_node *parent, cdev_t dev)
{
	struct devfs_node *node;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocvp -1-\n");
	node = devfs_allocp(devfsnodetype, name, parent, mp, dev);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocvp -2-\n");
	if (node != NULL)
		devfs_allocv(vpp, node);
	else
		*vpp = NULL;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_allocvp -end:3-\n");

	return 0;
}

/*
 * Destroy the devfs_node.  The node must be unlinked from the topology.
 *
 * This function will also destroy any vnode association with the node
 * and device.
 *
 * The cdev_t itself remains intact.
 */
int
devfs_freep(struct devfs_node *node)
{
	struct vnode *vp;

	KKASSERT(node);
	KKASSERT(((node->flags & DEVFS_NODE_LINKED) == 0) ||
		 (node->node_type == Proot));
	KKASSERT((node->flags & DEVFS_DESTROYED) == 0);

	atomic_subtract_int(&(DEVFS_MNTDATA(node->mp)->leak_count), 1);
	if (node->symlink_name)	{
		kfree(node->symlink_name, M_DEVFS);
		node->symlink_name = NULL;
	}

	/*
	 * Remove the node from the orphan list if it is still on it.
	 */
	if (node->flags & DEVFS_ORPHANED)
		devfs_tracer_del_orphan(node);

	/*
	 * Disassociate the vnode from the node.  This also prevents the
	 * vnode's reclaim code from double-freeing the node.
	 */
	if ((vp = node->v_node) != NULL) {
#if 0
		vp->v_rdev = NULL;
#endif
		v_release_rdev(vp);
		vp->v_data = NULL;
		node->v_node = NULL;
	}
	if (node->d_dir.d_name)
		kfree(node->d_dir.d_name, M_DEVFS);
	node->flags |= DEVFS_DESTROYED;

	objcache_put(devfs_node_cache, node);

	return 0;
}

/*
 * Unlink the devfs node from the topology and add it to the orphan list.
 * The node will later be destroyed by freep.
 *
 * Any vnode association, including the v_rdev and v_data, remains intact
 * until the freep.
 */
int
devfs_unlinkp(struct devfs_node *node)
{
	struct devfs_node *parent;
	KKASSERT(node);

	devfs_tracer_add_orphan(node);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_unlinkp for %s\n", node->d_dir.d_name);
	parent = node->parent;

	/*
	 * If the parent is known we can unlink the node out of the topology
	 */
	if (parent)	{
		TAILQ_REMOVE(DEVFS_DENODE_HEAD(parent), node, link);
		parent->nchildren--;
		KKASSERT((parent->nchildren >= 0));
		node->flags &= ~DEVFS_NODE_LINKED;
	}
	node->parent = NULL;
	return 0;
}

/*
 * devfs_reaperp() is a recursive function that iterates through all the
 * topology, unlinking and freeing all devfs nodes.
 */
int
devfs_reaperp(struct devfs_node *node)
{
	struct devfs_node *node1, *node2;

	if ((node->node_type == Proot) || (node->node_type == Pdir)) {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "This node is Pdir or Proot; has %d children\n",
			    node->nchildren);
		if (node->nchildren > 2) {
			TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node),
					      link, node2) {
				devfs_reaperp(node1);
			}
		}
	}
	devfs_unlinkp(node);
	devfs_freep(node);

	return 0;
}

/*
 * devfs_gc() is devfs garbage collector. It takes care of unlinking and
 * freeing a node, but also removes empty directories and links that link
 * via devfs auto-link mechanism to the node being deleted.
 */
int
devfs_gc(struct devfs_node *node)
{
	struct devfs_node *root_node = DEVFS_MNTDATA(node->mp)->root_node;

	devfs_gc_links(root_node, node, node->nlinks);
	devfs_unlinkp(node);
	devfs_gc_dirs(root_node);

	devfs_freep(node);

	return 0;
}

/*
 * devfs_gc_dirs() is a helper function for devfs_gc, unlinking and freeing
 * empty directories.
 */
static int
devfs_gc_dirs(struct devfs_node *node)
{
	struct devfs_node *node1, *node2;

	if ((node->node_type == Proot) || (node->node_type == Pdir)) {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "This node is Pdir or Proot; has %d children\n",
			    node->nchildren);
		if (node->nchildren > 2) {
			TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node),
					      link, node2) {
				devfs_gc_dirs(node1);
			}
		}

		if (node->nchildren == 2) {
			devfs_debug(DEVFS_DEBUG_DEBUG,
				    "This node is called %s and it is empty\n",
				    node->d_dir.d_name);
			devfs_unlinkp(node);
			devfs_freep(node);
		}
	}

	return 0;
}

/*
 * devfs_gc_links() is a helper function for devfs_gc, unlinking and freeing
 * eauto-linked nodes linking to the node being deleted.
 */
static int
devfs_gc_links(struct devfs_node *node, struct devfs_node *target,
	       size_t nlinks)
{
	struct devfs_node *node1, *node2;

	if (nlinks > 0) {
		if ((node->node_type == Proot) || (node->node_type == Pdir)) {
			devfs_debug(DEVFS_DEBUG_DEBUG, "This node is Pdir or Proot; has %d children\n", node->nchildren);
			if (node->nchildren > 2) {
				TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node), link, node2)	{
					nlinks = devfs_gc_links(node1, target, nlinks);
				}
			}
		} else if (node->link_target == target) {
			nlinks--;
			devfs_unlinkp(node);
			devfs_freep(node);
		}
	}

	KKASSERT(nlinks >= 0);

	return nlinks;
}

/*
 * devfs_create_dev() is the asynchronous entry point for device creation.
 * It just sends a message with the relevant details to the devfs core.
 *
 * This function will reference the passed device.  The reference is owned
 * by devfs and represents all of the device's node associations.
 */
int
devfs_create_dev(cdev_t dev, uid_t uid, gid_t gid, int perms)
{
	__uint64_t id;
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_create_dev -1-, name: %s (%p)\n",
		    dev->si_name, dev);
	reference_dev(dev);
	id = devfs_msg_send_dev(DEVFS_DEVICE_CREATE, dev, uid, gid, perms);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_create_dev -end:2- (unique id: %x) / (%p)\n",
		    id, dev);
	return 0;
}

/*
 * devfs_destroy_dev() is the asynchronous entry point for device destruction.
 * It just sends a message with the relevant details to the devfs core.
 */
int
devfs_destroy_dev(cdev_t dev)
{
	devfs_msg_send_dev(DEVFS_DEVICE_DESTROY, dev, 0, 0, 0);
	return 0;
}

/*
 * devfs_mount_add() is the synchronous entry point for adding a new devfs
 * mount.  It sends a synchronous message with the relevant details to the
 * devfs core.
 */
int
devfs_mount_add(struct devfs_mnt_data *mnt)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_mnt = mnt;
	msg = devfs_msg_send_sync(DEVFS_MOUNT_ADD, msg);
	devfs_msg_put(msg);

	return 0;
}

/*
 * devfs_mount_del() is the synchronous entry point for removing a devfs mount.
 * It sends a synchronous message with the relevant details to the devfs core.
 */
int
devfs_mount_del(struct devfs_mnt_data *mnt)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_mnt = mnt;
	msg = devfs_msg_send_sync(DEVFS_MOUNT_DEL, msg);
	devfs_msg_put(msg);

	return 0;
}

/*
 * devfs_destroy_subnames() is the synchronous entry point for device destruction
 * by subname. It just sends a message with the relevant details to the devfs core.
 */
int
devfs_destroy_subnames(char *name)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_load = name;
	msg = devfs_msg_send_sync(DEVFS_DESTROY_SUBNAMES, msg);
	devfs_msg_put(msg);
	return 0;
}

int
devfs_clr_subnames_flag(char *name, uint32_t flag)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_flags.name = name;
	msg->mdv_flags.flag = flag;
	msg = devfs_msg_send_sync(DEVFS_CLR_SUBNAMES_FLAG, msg);
	devfs_msg_put(msg);

	return 0;
}

int
devfs_destroy_subnames_without_flag(char *name, uint32_t flag)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_flags.name = name;
	msg->mdv_flags.flag = flag;
	msg = devfs_msg_send_sync(DEVFS_DESTROY_SUBNAMES_WO_FLAG, msg);
	devfs_msg_put(msg);

	return 0;
}

/*
 * devfs_create_all_dev is the asynchronous entry point to trigger device
 * node creation.  It just sends a message with the relevant details to
 * the devfs core.
 */
int
devfs_create_all_dev(struct devfs_node *root)
{
	devfs_msg_send_generic(DEVFS_CREATE_ALL_DEV, root);
	return 0;
}

/*
 * devfs_destroy_dev_by_ops is the asynchronous entry point to destroy all
 * devices with a specific set of dev_ops and minor.  It just sends a
 * message with the relevant details to the devfs core.
 */
int
devfs_destroy_dev_by_ops(struct dev_ops *ops, int minor)
{
	devfs_msg_send_ops(DEVFS_DESTROY_DEV_BY_OPS, ops, minor);
	return 0;
}

/*
 * devfs_clone_handler_add is the synchronous entry point to add a new
 * clone handler.  It just sends a message with the relevant details to
 * the devfs core.
 */
int
devfs_clone_handler_add(char *name, d_clone_t *nhandler)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
    msg->mdv_chandler.name = name;
	msg->mdv_chandler.nhandler = nhandler;
	msg = devfs_msg_send_sync(DEVFS_CHANDLER_ADD, msg);
	devfs_msg_put(msg);
	return 0;
}

/*
 * devfs_clone_handler_del is the synchronous entry point to remove a
 * clone handler.  It just sends a message with the relevant details to
 * the devfs core.
 */
int
devfs_clone_handler_del(char *name)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();
    msg->mdv_chandler.name = name;
	msg->mdv_chandler.nhandler = NULL;
	msg = devfs_msg_send_sync(DEVFS_CHANDLER_DEL, msg);
	devfs_msg_put(msg);
	return 0;
}

/*
 * devfs_find_device_by_name is the synchronous entry point to find a
 * device given its name.  It sends a synchronous message with the
 * relevant details to the devfs core and returns the answer.
 */
cdev_t
devfs_find_device_by_name(const char *fmt, ...)
{
	cdev_t found = NULL;
	devfs_msg_t msg;
	char target[PATH_MAX+1];
	__va_list ap;
	int i;

	if (fmt == NULL)
		return NULL;


	__va_start(ap, fmt);
	i = kvcprintf(fmt, NULL, target, 10, ap);
	target[i] = '\0';
	__va_end(ap);


	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_find_device_by_name: %s -1-\n", target);
	msg = devfs_msg_get();
	msg->mdv_name = target;
	msg = devfs_msg_send_sync(DEVFS_FIND_DEVICE_BY_NAME, msg);
	found = msg->mdv_cdev;
	devfs_msg_put(msg);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_find_device_by_name found? %s  -end:2-\n", (found)?"YES":"NO");
	return found;
}

/*
 * devfs_find_device_by_udev is the synchronous entry point to find a
 * device given its udev number.  It sends a synchronous message with
 * the relevant details to the devfs core and returns the answer.
 */
cdev_t
devfs_find_device_by_udev(udev_t udev)
{
	cdev_t found = NULL;
	devfs_msg_t msg;

	msg = devfs_msg_get();
	msg->mdv_udev = udev;
	msg = devfs_msg_send_sync(DEVFS_FIND_DEVICE_BY_UDEV, msg);
	found = msg->mdv_cdev;
	devfs_msg_put(msg);

	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_find_device_by_udev found? %s  -end:3-\n",
		    ((found) ? found->si_name:"NO"));
	return found;
}

/*
 * devfs_make_alias is the asynchronous entry point to register an alias
 * for a device.  It just sends a message with the relevant details to the
 * devfs core.
 */
int
devfs_make_alias(char *name, cdev_t dev_target)
{
	struct devfs_alias *alias;

	alias = kmalloc(sizeof(struct devfs_alias), M_DEVFS, M_WAITOK);
	memcpy(alias->name, name, strlen(name) + 1);
	alias->dev_target = dev_target;

	devfs_msg_send_generic(DEVFS_MAKE_ALIAS, alias);
	return 0;
}

/*
 * devfs_apply_rules is the asynchronous entry point to trigger application
 * of all rules.  It just sends a message with the relevant details to the
 * devfs core.
 */
int
devfs_apply_rules(char *mntto)
{
	char *new_name;
	size_t	namelen;

	namelen = strlen(mntto) + 1;

	new_name = kmalloc(namelen, M_DEVFS, M_WAITOK);

	memcpy(new_name, mntto, namelen);

	devfs_msg_send_name(DEVFS_APPLY_RULES, new_name);
	return 0;
}

/*
 * devfs_reset_rules is the asynchronous entry point to trigger reset of all rules.
 * It just sends a message with the relevant details to the devfs core.
 */
int
devfs_reset_rules(char *mntto)
{
	char *new_name;
	size_t	namelen;

	namelen = strlen(mntto) + 1;

	new_name = kmalloc(namelen, M_DEVFS, M_WAITOK);

	memcpy(new_name, mntto, namelen);

	devfs_msg_send_name(DEVFS_RESET_RULES, new_name);
	return 0;
}


/*
 * devfs_scan_callback is the asynchronous entry point to call a callback
 * on all cdevs.
 * It just sends a message with the relevant details to the devfs core.
 */
int
devfs_scan_callback(devfs_scan_t *callback)
{
	devfs_msg_t msg;

	/* Make sure that function pointers have the size of a generic pointer (innecessary) */
	KKASSERT(sizeof(callback) == sizeof(void *));

	msg = devfs_msg_get();
	msg->mdv_load = callback;
	msg = devfs_msg_send_sync(DEVFS_SCAN_CALLBACK, msg);
	devfs_msg_put(msg);

	return 0;
}


/*
 * Acts as a message drain. Any message that is replied to here gets destroyed and
 * the memory freed.
 */
static void
devfs_msg_autofree_reply(lwkt_port_t port, lwkt_msg_t msg)
{
	devfs_msg_put((devfs_msg_t)msg);
}

/*
 * devfs_msg_get allocates a new devfs msg and returns it.
 */
devfs_msg_t
devfs_msg_get()
{
	return objcache_get(devfs_msg_cache, M_WAITOK);
}

/*
 * devfs_msg_put deallocates a given devfs msg.
 */
int
devfs_msg_put(devfs_msg_t msg)
{
	objcache_put(devfs_msg_cache, msg);
	return 0;
}

/*
 * devfs_msg_send is the generic asynchronous message sending facility
 * for devfs. By default the reply port is the automatic disposal port.
 */
__uint32_t
devfs_msg_send(uint32_t cmd, devfs_msg_t devfs_msg)
{
	lwkt_port_t port = &devfs_msg_port;

    lwkt_initmsg(&devfs_msg->hdr, &devfs_dispose_port, 0);

    devfs_msg->hdr.u.ms_result = cmd;
	devfs_msg->id = atomic_fetchadd_int(&msg_id, 1);

    lwkt_sendmsg(port, (lwkt_msg_t)devfs_msg);

	return devfs_msg->id;
}

/*
 * devfs_msg_send_sync is the generic synchronous message sending
 * facility for devfs. It initializes a local reply port and waits
 * for the core's answer. This answer is then returned.
 */
devfs_msg_t
devfs_msg_send_sync(uint32_t cmd, devfs_msg_t devfs_msg)
{
	struct lwkt_port rep_port;
	devfs_msg_t	msg_incoming;
	lwkt_port_t port = &devfs_msg_port;

	lwkt_initport_thread(&rep_port, curthread);
    lwkt_initmsg(&devfs_msg->hdr, &rep_port, 0);

    devfs_msg->hdr.u.ms_result = cmd;
	devfs_msg->id = atomic_fetchadd_int(&msg_id, 1);

    lwkt_sendmsg(port, (lwkt_msg_t)devfs_msg);
	msg_incoming = lwkt_waitport(&rep_port, 0);

	return msg_incoming;
}

/*
 * sends a message with a generic argument.
 */
__uint32_t
devfs_msg_send_generic(uint32_t cmd, void *load)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_load = load;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_send_generic -1- (%p)\n", load);

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with a name argument.
 */
__uint32_t
devfs_msg_send_name(uint32_t cmd, char *name)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_name = name;

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with a mount argument.
 */
__uint32_t
devfs_msg_send_mount(uint32_t cmd, struct devfs_mnt_data *mnt)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_mnt = mnt;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_send_mp -1- (%p)\n", mnt);

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with an ops argument.
 */
__uint32_t
devfs_msg_send_ops(uint32_t cmd, struct dev_ops *ops, int minor)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_ops.ops = ops;
	devfs_msg->mdv_ops.minor = minor;

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with a clone handler argument.
 */
__uint32_t
devfs_msg_send_chandler(uint32_t cmd, char *name, d_clone_t handler)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_chandler.name = name;
	devfs_msg->mdv_chandler.nhandler = handler;

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with a device argument.
 */
__uint32_t
devfs_msg_send_dev(uint32_t cmd, cdev_t dev, uid_t uid, gid_t gid, int perms)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_dev.dev = dev;
	devfs_msg->mdv_dev.uid = uid;
	devfs_msg->mdv_dev.gid = gid;
	devfs_msg->mdv_dev.perms = perms;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_send_dev -1- (%p)\n", dev);

	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * sends a message with a link argument.
 */
__uint32_t
devfs_msg_send_link(uint32_t cmd, char *name, char *target, struct mount *mp)
{
    devfs_msg_t devfs_msg = devfs_msg_get();
    devfs_msg->mdv_link.name = name;
	devfs_msg->mdv_link.target = target;
	devfs_msg->mdv_link.mp = mp;


	return devfs_msg_send(cmd, devfs_msg);
}

/*
 * devfs_msg_core is the main devfs thread. It handles all incoming messages
 * and calls the relevant worker functions. By using messages it's assured
 * that events occur in the correct order.
 */
static void
devfs_msg_core(void *arg)
{
	uint8_t  run = 1;
	devfs_msg_t msg;
	cdev_t	dev;
	struct devfs_mnt_data *mnt;
	struct devfs_node *node;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core -1-\n");
	lwkt_initport_thread(&devfs_msg_port, curthread);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core -2-\n");
	wakeup(td_core/*devfs_id*/);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core -3-\n");

	while (run) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core -loop:4-\n");
		msg = (devfs_msg_t)lwkt_waitport(&devfs_msg_port, 0);
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core, new msg: %x (unique id: %x)\n", (unsigned int)msg->hdr.u.ms_result, msg->id);
		lockmgr(&devfs_lock, LK_EXCLUSIVE);
		switch (msg->hdr.u.ms_result) {

		case DEVFS_DEVICE_CREATE:
			dev = msg->mdv_dev.dev;
			devfs_debug(DEVFS_DEBUG_DEBUG,
				    "devfs_msg_core device create msg %s(%p)\n",
				    dev->si_name, dev);
			devfs_create_dev_worker(dev,
						msg->mdv_dev.uid,
						msg->mdv_dev.gid,
						msg->mdv_dev.perms);
			break;

		case DEVFS_DEVICE_DESTROY:
			devfs_debug(DEVFS_DEBUG_DEBUG,
				    "devfs_msg_core device destroy msg\n");
			dev = msg->mdv_dev.dev;
			devfs_destroy_dev_worker(dev);
			break;

		case DEVFS_DESTROY_SUBNAMES:
			devfs_destroy_subnames_worker(msg->mdv_load);
			break;

		case DEVFS_DESTROY_DEV_BY_OPS:
			devfs_destroy_dev_by_ops_worker(msg->mdv_ops.ops,
							msg->mdv_ops.minor);
			break;

		case DEVFS_CREATE_ALL_DEV:
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_msg_core device create ALL msg\n");
			node = (struct devfs_node *)msg->mdv_load;
			devfs_create_all_dev_worker(node);
			break;

		case DEVFS_MOUNT_ADD:
			mnt = msg->mdv_mnt;
			TAILQ_INSERT_TAIL(&devfs_mnt_list, mnt, link);
			devfs_create_all_dev_worker(mnt->root_node);
			break;

		case DEVFS_MOUNT_DEL:
			mnt = msg->mdv_mnt;
			TAILQ_REMOVE(&devfs_mnt_list, mnt, link);
			devfs_reaperp(mnt->root_node);
			if (mnt->leak_count) {
				devfs_debug(DEVFS_DEBUG_SHOW,
					    "Leaked %d devfs_node elements!\n",
					    mnt->leak_count);
			}
			break;

		case DEVFS_CHANDLER_ADD:
			devfs_chandler_add_worker(msg->mdv_chandler.name, msg->mdv_chandler.nhandler);
			break;

		case DEVFS_CHANDLER_DEL:
			devfs_chandler_del_worker(msg->mdv_chandler.name);
			break;

		case DEVFS_FIND_DEVICE_BY_NAME:
			devfs_find_device_by_name_worker(msg);
			break;

		case DEVFS_FIND_DEVICE_BY_UDEV:
			devfs_find_device_by_udev_worker(msg);
			break;

		case DEVFS_MAKE_ALIAS:
			devfs_make_alias_worker((struct devfs_alias *)msg->mdv_load);
			break;

		case DEVFS_APPLY_RULES:
			devfs_apply_reset_rules_caller(msg->mdv_name, 1);
			break;

		case DEVFS_RESET_RULES:
			devfs_apply_reset_rules_caller(msg->mdv_name, 0);
			break;

		case DEVFS_SCAN_CALLBACK:
			devfs_scan_callback_worker((devfs_scan_t *)msg->mdv_load);
			break;

		case DEVFS_CLR_SUBNAMES_FLAG:
			devfs_clr_subnames_flag_worker(msg->mdv_flags.name,
											msg->mdv_flags.flag);
			break;

		case DEVFS_DESTROY_SUBNAMES_WO_FLAG:
			devfs_destroy_subnames_without_flag_worker(msg->mdv_flags.name,
														msg->mdv_flags.flag);
			break;

		case DEVFS_TERMINATE_CORE:
			run = 0;
			break;
		case DEVFS_SYNC:
			break;
		default:
			devfs_debug(DEVFS_DEBUG_DEBUG,
				    "devfs_msg_core: unknown message "
				    "received at core\n");
			break;
		}
		lockmgr(&devfs_lock, LK_RELEASE);

		lwkt_replymsg((lwkt_msg_t)msg, 0);
	}
	wakeup(td_core/*devfs_id*/);
	lwkt_exit();
}

/*
 * Worker function to insert a new dev into the dev list and initialize its
 * permissions. It also calls devfs_propagate_dev which in turn propagates
 * the change to all mount points.
 *
 * The passed dev is already referenced.  This reference is eaten by this
 * function and represents the dev's linkage into devfs_dev_list.
 */
static int
devfs_create_dev_worker(cdev_t dev, uid_t uid, gid_t gid, int perms)
{
	KKASSERT(dev);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_create_dev_worker -1- -%s- (%p)\n",
		    dev->si_name, dev);

	dev->si_uid = uid;
	dev->si_gid = gid;
	dev->si_perms = perms;

	devfs_link_dev(dev);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_dev_worker -2-\n");
	devfs_propagate_dev(dev, 1);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_dev_worker -end:3-\n");
	return 0;
}

/*
 * Worker function to delete a dev from the dev list and free the cdev.
 * It also calls devfs_propagate_dev which in turn propagates the change
 * to all mount points.
 */
static int
devfs_destroy_dev_worker(cdev_t dev)
{
	int error;

	KKASSERT(dev);
	KKASSERT((lockstatus(&devfs_lock, curthread)) == LK_EXCLUSIVE);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_destroy_dev_worker -1- %s\n", dev->si_name);
	error = devfs_unlink_dev(dev);
	devfs_propagate_dev(dev, 0);
	if (error == 0)
		release_dev(dev);	/* link ref */
	release_dev(dev);
	release_dev(dev);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_destroy_dev_worker -end:5-\n");
	return 0;
}

/*
 * Worker function to destroy all devices with a certain basename.
 * Calls devfs_destroy_dev_worker for the actual destruction.
 */
static int
devfs_destroy_subnames_worker(char *name)
{
	cdev_t dev, dev1;
	size_t len = strlen(name);

	TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		if (!strncmp(dev->si_name, name, len)) {
			if (dev->si_name[len] != '\0') {
				devfs_destroy_dev_worker(dev);
				/* release_dev(dev); */
			}
		}
	}
	return 0;
}

static int
devfs_clr_subnames_flag_worker(char *name, uint32_t flag)
{
	cdev_t dev, dev1;
	size_t len = strlen(name);

	TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		if (!strncmp(dev->si_name, name, len)) {
			if (dev->si_name[len] != '\0') {
				dev->si_flags &= ~flag;
			}
		}
	}

	return 0;
}

static int
devfs_destroy_subnames_without_flag_worker(char *name, uint32_t flag)
{
	cdev_t dev, dev1;
	size_t len = strlen(name);

	TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		if (!strncmp(dev->si_name, name, len)) {
			if (dev->si_name[len] != '\0') {
				if (!(dev->si_flags & flag)) {
					devfs_destroy_dev_worker(dev);
				}
			}
		}
	}

	return 0;
}

/*
 * Worker function that creates all device nodes on top of a devfs
 * root node.
 */
static int
devfs_create_all_dev_worker(struct devfs_node *root)
{
	cdev_t dev;

	KKASSERT(root);
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_all_dev_worker -1-\n");

    TAILQ_FOREACH(dev, &devfs_dev_list, link) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_all_dev_worker -loop:2- -%s-\n", dev->si_name);
		devfs_create_device_node(root, dev, NULL, NULL);
    }
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_all_dev_worker -end:3-\n");
	return 0;
}

/*
 * Worker function that destroys all devices that match a specific
 * dev_ops and/or minor. If minor is less than 0, it is not matched
 * against. It also propagates all changes.
 */
static int
devfs_destroy_dev_by_ops_worker(struct dev_ops *ops, int minor)
{
	cdev_t dev, dev1;

	KKASSERT(ops);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_destroy_dev_by_ops_worker -1-\n");

	TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		if (dev->si_ops != ops)
			continue;
		if ((minor < 0) || (dev->si_uminor == minor)) {
			devfs_debug(DEVFS_DEBUG_DEBUG,
				    "devfs_destroy_dev_by_ops_worker "
				    "-loop:2- -%s-\n",
				    dev->si_name);
			devfs_destroy_dev_worker(dev);
		}
	}
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "devfs_destroy_dev_by_ops_worker -end:3-\n");
	return 0;
}

/*
 * Worker function that registers a new clone handler in devfs.
 */
static int
devfs_chandler_add_worker(char *name, d_clone_t *nhandler)
{
	struct devfs_clone_handler *chandler = NULL;
	u_char len = strlen(name);

	if (len == 0)
		return 1;

	TAILQ_FOREACH(chandler, &devfs_chandler_list, link) {
		if (chandler->namlen == len) {
			if (!memcmp(chandler->name, name, len)) {
				/* Clonable basename already exists */
				return 1;
			}
		}
	}

	chandler = kmalloc(sizeof(*chandler), M_DEVFS, M_WAITOK | M_ZERO);
	memcpy(chandler->name, name, len+1);
	chandler->namlen = len;
	chandler->nhandler = nhandler;

	TAILQ_INSERT_TAIL(&devfs_chandler_list, chandler, link);
	return 0;
}

/*
 * Worker function that removes a given clone handler from the
 * clone handler list.
 */
static int
devfs_chandler_del_worker(char *name)
{
	struct devfs_clone_handler *chandler, *chandler2;
	u_char len = strlen(name);

	if (len == 0)
		return 1;

	TAILQ_FOREACH_MUTABLE(chandler, &devfs_chandler_list, link, chandler2) {
		if (chandler->namlen != len)
			continue;
		if (memcmp(chandler->name, name, len))
			continue;
		TAILQ_REMOVE(&devfs_chandler_list, chandler, link);
		kfree(chandler, M_DEVFS);
	}

	return 0;
}

/*
 * Worker function that finds a given device name and changes
 * the message received accordingly so that when replied to,
 * the answer is returned to the caller.
 */
static int
devfs_find_device_by_name_worker(devfs_msg_t devfs_msg)
{
	struct devfs_alias *alias;
	cdev_t dev;
	cdev_t found = NULL;

	TAILQ_FOREACH(dev, &devfs_dev_list, link) {
		if (strcmp(devfs_msg->mdv_name, dev->si_name) == 0) {
			found = dev;
			break;
		}
	}
	if (found == NULL) {
		TAILQ_FOREACH(alias, &devfs_alias_list, link) {
			if (strcmp(devfs_msg->mdv_name, alias->name) == 0) {
				found = alias->dev_target;
				break;
			}
		}
	}
	devfs_msg->mdv_cdev = found;

	return 0;
}

/*
 * Worker function that finds a given device udev and changes
 * the message received accordingly so that when replied to,
 * the answer is returned to the caller.
 */
static int
devfs_find_device_by_udev_worker(devfs_msg_t devfs_msg)
{
	cdev_t dev, dev1;
	cdev_t found = NULL;

	TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		if (((udev_t)dev->si_inode) == devfs_msg->mdv_udev) {
			found = dev;
			break;
		}
	}
	devfs_msg->mdv_cdev = found;

	return 0;
}

/*
 * Worker function that inserts a given alias into the
 * alias list, and propagates the alias to all mount
 * points.
 */
static int
devfs_make_alias_worker(struct devfs_alias *alias)
{
	struct devfs_alias *alias2;
	size_t len = strlen(alias->name);
	int found = 0;

	TAILQ_FOREACH(alias2, &devfs_alias_list, link) {
		if (!memcmp(alias->name, alias2->name, len)) { /* XXX */
			found = 1;
			break;
		}
	}

	if (!found) {
		TAILQ_INSERT_TAIL(&devfs_alias_list, alias, link);
		devfs_alias_propagate(alias);
	} else {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "Warning: duplicate devfs_make_alias for %s\n",
			    alias->name);
		kfree(alias, M_DEVFS);
	}

	return 0;
}

/*
 * Function that removes and frees all aliases.
 */
static int
devfs_alias_reap(void)
{
	struct devfs_alias *alias, *alias2;

	TAILQ_FOREACH_MUTABLE(alias, &devfs_alias_list, link, alias2) {
		TAILQ_REMOVE(&devfs_alias_list, alias, link);
		kfree(alias, M_DEVFS);
	}
	return 0;
}

/*
 * Function that removes an alias matching a specific cdev and frees
 * it accordingly.
 */
static int
devfs_alias_remove(cdev_t dev)
{
	struct devfs_alias *alias, *alias2;

	TAILQ_FOREACH_MUTABLE(alias, &devfs_alias_list, link, alias2) {
		if (alias->dev_target == dev) {
			TAILQ_REMOVE(&devfs_alias_list, alias, link);
			kfree(alias, M_DEVFS);
		}
	}
	return 0;
}

/*
 * This function propagates a new alias to all mount points.
 */
static int
devfs_alias_propagate(struct devfs_alias *alias)
{
	struct devfs_mnt_data *mnt;

	TAILQ_FOREACH(mnt, &devfs_mnt_list, link) {
		devfs_alias_apply(mnt->root_node, alias);
	}
	return 0;
}

/*
 * This function is a recursive function iterating through
 * all device nodes in the topology and, if applicable,
 * creating the relevant alias for a device node.
 */
static int
devfs_alias_apply(struct devfs_node *node, struct devfs_alias *alias)
{
	struct devfs_node *node1, *node2;

	KKASSERT(alias != NULL);

	if ((node->node_type == Proot) || (node->node_type == Pdir)) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "This node is Pdir or Proot; has %d children\n", node->nchildren);
		if (node->nchildren > 2) {
			TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node), link, node2) {
				devfs_alias_apply(node1, alias);
			}
		}
	} else {
		if (node->d_dev == alias->dev_target)
			devfs_alias_create(alias->name, node);
	}
	return 0;
}

/*
 * This function checks if any alias possibly is applicable
 * to the given node. If so, the alias is created.
 */
static int
devfs_alias_check_create(struct devfs_node *node)
{
	struct devfs_alias *alias;

	TAILQ_FOREACH(alias, &devfs_alias_list, link) {
		if (node->d_dev == alias->dev_target)
			devfs_alias_create(alias->name, node);
	}
	return 0;
}

/*
 * This function creates an alias with a given name
 * linking to a given devfs node. It also increments
 * the link count on the target node.
 */
int
devfs_alias_create(char *name_orig, struct devfs_node *target)
{
	struct mount *mp = target->mp;
	struct devfs_node *parent = DEVFS_MNTDATA(mp)->root_node;
	struct devfs_node *linknode;
	char *create_path = NULL;
	char *name, name_buf[PATH_MAX];

	KKASSERT((lockstatus(&devfs_lock, curthread)) == LK_EXCLUSIVE);

	devfs_resolve_name_path(name_orig, name_buf, &create_path, &name);

	if (create_path)
		parent = devfs_resolve_or_create_path(parent, create_path, 1);


	if (devfs_find_device_node_by_name(parent, name)) {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "Node already exists: %s "
			    "(devfs_make_alias_worker)!\n",
			    name);
		return 1;
	}


	linknode = devfs_allocp(Plink, name, parent, mp, NULL);
	if (linknode == NULL)
		return 1;

	linknode->link_target = target;
	target->nlinks++;
#if 0
	linknode->flags |= DEVFS_LINK;
#endif

	return 0;
}

/*
 * This function is called by the core and handles mount point
 * strings. It either calls the relevant worker (devfs_apply_
 * reset_rules_worker) on all mountpoints or only a specific
 * one.
 */
static int
devfs_apply_reset_rules_caller(char *mountto, int apply)
{
	struct devfs_mnt_data *mnt;
	size_t len = strlen(mountto);

	if (mountto[0] != '*') {
		TAILQ_FOREACH(mnt, &devfs_mnt_list, link) {
			if ((len == mnt->mntonnamelen) &&
				(!memcmp(mnt->mp->mnt_stat.f_mntonname, mountto, len))) {
				devfs_apply_reset_rules_worker(mnt->root_node, apply);
				break;
			}
		}
	} else {
		TAILQ_FOREACH(mnt, &devfs_mnt_list, link) {
			devfs_apply_reset_rules_worker(mnt->root_node, apply);
		}
	}

	kfree(mountto, M_DEVFS);
	return 0;
}

/*
 * This worker function applies or resets, depending on the arguments, a rule
 * to the whole given topology. *RECURSIVE*
 */
static int
devfs_apply_reset_rules_worker(struct devfs_node *node, int apply)
{
	struct devfs_node *node1, *node2;

	if ((node->node_type == Proot) || (node->node_type == Pdir)) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "This node is Pdir or Proot; has %d children\n", node->nchildren);
		if (node->nchildren > 2) {
			TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node), link, node2)	{
				devfs_apply_reset_rules_worker(node1, apply);
			}
		}
	}

	if (apply)
		devfs_rule_check_apply(node);
	else
		devfs_rule_reset_node(node);

	return 0;
}


/*
 * This function calls a given callback function for
 * every dev node in the devfs dev list.
 */
static int
devfs_scan_callback_worker(devfs_scan_t *callback)
{
	cdev_t dev, dev1;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_scan_callback: %p -1-\n", callback);

    TAILQ_FOREACH_MUTABLE(dev, &devfs_dev_list, link, dev1) {
		callback(dev);
    }

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_scan_callback: finished\n");
	return 0;
}


/*
 * This function tries to resolve a given directory, or if not
 * found and creation requested, creates the given directory.
 */
static struct devfs_node *
devfs_resolve_or_create_dir(struct devfs_node *parent, char *dir_name,
			    size_t name_len, int create)
{
	struct devfs_node *node, *found = NULL;

	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(parent), link) {
		if (name_len == node->d_dir.d_namlen) {
			if (!memcmp(dir_name, node->d_dir.d_name, name_len)) {
				found = node;
				break;
			}
		}
	}

	if ((found == NULL) && (create)) {
		found = devfs_allocp(Pdir, dir_name, parent, parent->mp, NULL);
	}

	return found;
}

/*
 * This function tries to resolve a complete path. If creation is requested,
 * if a given part of the path cannot be resolved (because it doesn't exist),
 * it is created.
 */
struct devfs_node *
devfs_resolve_or_create_path(struct devfs_node *parent, char *path, int create)
{
	struct devfs_node *node = parent;
	char buf[PATH_MAX];
	size_t idx = 0;


	if (path == NULL)
		return parent;


	for (; *path != '\0' ; path++) {
		if (*path != '/') {
			buf[idx++] = *path;
		} else {
			buf[idx] = '\0';
			node = devfs_resolve_or_create_dir(node, buf, idx, create);
			if (node == NULL)
				return NULL;
			idx = 0;
		}
	}
	buf[idx] = '\0';
	return devfs_resolve_or_create_dir(node, buf, idx, create);
}

/*
 * Takes a full path and strips it into a directory path and a name.
 * For a/b/c/foo, it returns foo in namep and a/b/c in pathp. It
 * requires a working buffer with enough size to keep the whole
 * fullpath.
 */
int
devfs_resolve_name_path(char *fullpath, char *buf, char **pathp, char **namep)
{
	char *name = NULL;
	char *path = NULL;
	size_t len = strlen(fullpath) + 1;
	int i;

	KKASSERT((fullpath != NULL) && (buf != NULL) && (pathp != NULL) && (namep != NULL));

	memcpy(buf, fullpath, len);

	for (i = len-1; i>= 0; i--) {
		if (buf[i] == '/') {
			buf[i] = '\0';
			name = &(buf[i+1]);
			path = buf;
			break;
		}
	}

	*pathp = path;

	if (name) {
		*namep = name;
	} else {
		*namep = buf;
	}

	return 0;
}

/*
 * This function creates a new devfs node for a given device.  It can
 * handle a complete path as device name, and accordingly creates
 * the path and the final device node.
 *
 * The reference count on the passed dev remains unchanged.
 */
struct devfs_node *
devfs_create_device_node(struct devfs_node *root, cdev_t dev,
			 char *dev_name, char *path_fmt, ...)
{
	struct devfs_node *parent, *node = NULL;
	char *path = NULL;
	char *name, name_buf[PATH_MAX];
	__va_list ap;
	int i, found;

	char *create_path = NULL;
	char *names = "pqrsPQRS";

	if (path_fmt != NULL) {
		path = kmalloc(PATH_MAX+1, M_DEVFS, M_WAITOK);

		__va_start(ap, path_fmt);
		i = kvcprintf(path_fmt, NULL, path, 10, ap);
		path[i] = '\0';
		__va_end(ap);
	}

	parent = devfs_resolve_or_create_path(root, path, 1);
	KKASSERT(parent);

	devfs_resolve_name_path(((dev_name == NULL) && (dev))?(dev->si_name):(dev_name), name_buf, &create_path, &name);

	if (create_path)
		parent = devfs_resolve_or_create_path(parent, create_path, 1);


	if (devfs_find_device_node_by_name(parent, name)) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_device_node: "
			"DEVICE %s ALREADY EXISTS!!! Ignoring creation request.\n", name);
		goto out;
	}
	devfs_debug(DEVFS_DEBUG_DEBUG, "parent->d_dir.d_name=%s\n", parent->d_dir.d_name);
	node = devfs_allocp(Pdev, name, parent, parent->mp, dev);
	devfs_debug(DEVFS_DEBUG_DEBUG, "node->d_dir.d_name=%s\n", node->d_dir.d_name);

#if 0
	/* Ugly unix98 pty magic, to hide pty master (ptm) devices and their directory */
	if ((dev) && (strlen(dev->si_name) >= 4) && (!memcmp(dev->si_name, "ptm/", 4))) {
		node->parent->flags |= DEVFS_HIDDEN;
		node->flags |= DEVFS_HIDDEN;
	}
#endif
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_device_node: marker A\n");
	/* Ugly pty magic, to tag pty devices as such and hide them if needed */
	if ((strlen(name) >= 3) && (!memcmp(name, "pty", 3)))
		node->flags |= (DEVFS_PTY | DEVFS_INVISIBLE);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_device_node: marker B\n");
	if ((strlen(name) >= 3) && (!memcmp(name, "tty", 3))) {
		found = 0;
		for (i = 0; i < strlen(names); i++) {
			if (name[3] == names[i]) {
				found = 1;
				break;
			}
		}
		if (found)
			node->flags |= (DEVFS_PTY | DEVFS_INVISIBLE);
	}
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_create_device_node: marker C\n");

out:
	if (path_fmt != NULL)
		kfree(path, M_DEVFS);

	return node;
}

/*
 * This function finds a given device node in the topology with a given
 * cdev.
 */
struct devfs_node *
devfs_find_device_node(struct devfs_node *node, cdev_t target)
{
	struct devfs_node *node1, *node2, *found = NULL;

	if ((node->node_type == Proot) || (node->node_type == Pdir)) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "This node is Pdir or Proot; has %d children\n", node->nchildren);
		if (node->nchildren > 2) {
			TAILQ_FOREACH_MUTABLE(node1, DEVFS_DENODE_HEAD(node), link, node2)	{
				if ((found = devfs_find_device_node(node1, target)))
					return found;
			}
		}
	} else if (node->node_type == Pdev) {
		if (node->d_dev == target)
			return node;
	}

	return NULL;
}

/*
 * This function finds a device node in the topology by its
 * name and returns it.
 */
struct devfs_node *
devfs_find_device_node_by_name(struct devfs_node *parent, char *target)
{
	struct devfs_node *node, *found = NULL;
	size_t len = strlen(target);

	TAILQ_FOREACH(node, DEVFS_DENODE_HEAD(parent), link) {
		if ((len == node->d_dir.d_namlen) && (!memcmp(node->d_dir.d_name, target, len))) {
			found = node;
			break;
		}
	}

	return found;
}

/*
 * This function takes a cdev and removes its devfs node in the
 * given topology.  The cdev remains intact.
 */
int
devfs_destroy_device_node(struct devfs_node *root, cdev_t target)
{
	struct devfs_node *node, *parent;
	char *name, name_buf[PATH_MAX];
	char *create_path = NULL;

	KKASSERT(target);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_destroy_device_node\n");
	memcpy(name_buf, target->si_name, strlen(target->si_name)+1);

	devfs_resolve_name_path(target->si_name, name_buf, &create_path, &name);
	devfs_debug(DEVFS_DEBUG_DEBUG, "create_path: %s\n", create_path);
	devfs_debug(DEVFS_DEBUG_DEBUG, "name: %s\n", name);

	if (create_path)
		parent = devfs_resolve_or_create_path(root, create_path, 0);
	else
		parent = root;
	devfs_debug(DEVFS_DEBUG_DEBUG, "-> marker <-\n");
	if (parent == NULL)
		return 1;
	devfs_debug(DEVFS_DEBUG_DEBUG, "->d_dir.d_name=%s\n", parent->d_dir.d_name);
	node = devfs_find_device_node_by_name(parent, name);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "->d_dir.d_name=%s\n",
		    ((node) ? (node->d_dir.d_name) : "SHIT!"));
	if (node)
		devfs_gc(node);

	return 0;
}

/*
 * Just set perms and ownership for given node.
 */
int
devfs_set_perms(struct devfs_node *node, uid_t uid, gid_t gid, u_short mode, u_long flags)
{
	node->mode = mode;		/* files access mode and type */
	node->uid = uid;		/* owner user id */
	node->gid = gid;		/* owner group id */

	return 0;
}

/*
 * Propagates a device attach/detach to all mount
 * points. Also takes care of automatic alias removal
 * for a deleted cdev.
 */
static int
devfs_propagate_dev(cdev_t dev, int attach)
{
	struct devfs_mnt_data *mnt;

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_propagate_dev -1-\n");
	TAILQ_FOREACH(mnt, &devfs_mnt_list, link) {
		devfs_debug(DEVFS_DEBUG_DEBUG,
			    "devfs_propagate_dev -loop:2-\n");
		if (attach) {
			/* Device is being attached */
			devfs_create_device_node(mnt->root_node, dev,
						 NULL, NULL );
		} else {
			/* Device is being detached */
			devfs_alias_remove(dev);
			devfs_destroy_device_node(mnt->root_node, dev);
		}
	}
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_propagate_dev -end:3-\n");
	return 0;
}

/*
 * devfs_node_to_path takes a node and a buffer of a size of
 * at least PATH_MAX, resolves the full path from the root
 * node and writes it in a humanly-readable format into the
 * buffer.
 * If DEVFS_STASH_DEPTH is less than the directory level up
 * to the root node, only the last DEVFS_STASH_DEPTH levels
 * of the path are resolved.
 */
int
devfs_node_to_path(struct devfs_node *node, char *buffer)
{
#define DEVFS_STASH_DEPTH	32
	struct devfs_node *node_stash[DEVFS_STASH_DEPTH];
	int i, offset;
	memset(buffer, 0, PATH_MAX);

	for (i = 0; (i < DEVFS_STASH_DEPTH) && (node->node_type != Proot); i++) {
		node_stash[i] = node;
		node = node->parent;
	}
	i--;

	for (offset = 0; i >= 0; i--) {
		memcpy(buffer+offset, node_stash[i]->d_dir.d_name, node_stash[i]->d_dir.d_namlen);
		offset += node_stash[i]->d_dir.d_namlen;
		if (i > 0) {
			*(buffer+offset) = '/';
			offset++;
		}
	}
#undef DEVFS_STASH_DEPTH
	return 0;
}

/*
 * devfs_clone either returns a basename from a complete name by
 * returning the length of the name without trailing digits, or,
 * if clone != 0, calls the device's clone handler to get a new
 * device, which in turn is returned in devp.
 */
int
devfs_clone(char *name, size_t *namlenp, cdev_t *devp, int clone, struct ucred *cred)
{
	KKASSERT(namlenp);

	size_t len = *namlenp;
	int error = 1;
	struct devfs_clone_handler *chandler;
	struct dev_clone_args ap;

	if (!clone) {
		for (; (len > 0) && (DEVFS_ISDIGIT(name[len-1])); len--);
	}

    TAILQ_FOREACH(chandler, &devfs_chandler_list, link) {
		devfs_debug(DEVFS_DEBUG_DEBUG, "len=%d, chandler->namlen=%d\n", len, chandler->namlen);
		devfs_debug(DEVFS_DEBUG_DEBUG, "name=%s, chandler->name=%s\n", name, chandler->name);
		if ((chandler->namlen == len) &&
			(!memcmp(chandler->name, name, len)) &&
			(chandler->nhandler)) {
			devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_nclone: found clone handler for the base name at %p\n", chandler->nhandler);
			if (clone) {
				ap.a_dev = NULL;
				ap.a_name = name;
				ap.a_namelen = len;
				ap.a_cred = cred;
				error = (chandler->nhandler)(&ap);
				KKASSERT(devp);
				*devp = ap.a_dev;
			} else {
				*namlenp = len;
				error = 0;
			}

			break;
		}
	}

	return error;
}


/*
 * Registers a new orphan in the orphan list.
 */
void
devfs_tracer_add_orphan(struct devfs_node *node)
{
	struct devfs_orphan *orphan;

	KKASSERT(node);
	orphan = kmalloc(sizeof(struct devfs_orphan), M_DEVFS, M_WAITOK);
	orphan->node = node;

	KKASSERT((node->flags & DEVFS_ORPHANED) == 0);
	node->flags |= DEVFS_ORPHANED;
	TAILQ_INSERT_TAIL(DEVFS_ORPHANLIST(node->mp), orphan, link);
}

/*
 * Removes an orphan from the orphan list.
 */
void
devfs_tracer_del_orphan(struct devfs_node *node)
{
	struct devfs_orphan *orphan;

	KKASSERT(node);

	TAILQ_FOREACH(orphan, DEVFS_ORPHANLIST(node->mp), link)	{
		if (orphan->node == node) {
			node->flags &= ~DEVFS_ORPHANED;
			TAILQ_REMOVE(DEVFS_ORPHANLIST(node->mp), orphan, link);
			kfree(orphan, M_DEVFS);
			break;
		}
	}
}

/*
 * Counts the orphans in the orphan list, and if cleanup
 * is specified, also frees the orphan and removes it from
 * the list.
 */
size_t
devfs_tracer_orphan_count(struct mount *mp, int cleanup)
{
	struct devfs_orphan *orphan, *orphan2;
	size_t count = 0;

	TAILQ_FOREACH_MUTABLE(orphan, DEVFS_ORPHANLIST(mp), link, orphan2)	{
		count++;
		if (cleanup) {
			TAILQ_REMOVE(DEVFS_ORPHANLIST(mp), orphan, link);
			orphan->node->flags &= ~DEVFS_ORPHANED;
			devfs_freep(orphan->node);
			kfree(orphan, M_DEVFS);
		}
	}

	return count;
}

/*
 * Fetch an ino_t from the global d_ino by increasing it
 * while spinlocked.
 */
static ino_t
devfs_fetch_ino(void)
{
	ino_t	ret;

	spin_lock_wr(&ino_lock);
	ret = d_ino++;
	spin_unlock_wr(&ino_lock);

	return ret;
}

/*
 * Allocates a new cdev and initializes it's most basic
 * fields.
 */
cdev_t
devfs_new_cdev(struct dev_ops *ops, int minor)
{
	cdev_t dev = sysref_alloc(&cdev_sysref_class);
	sysref_activate(&dev->si_sysref);
	reference_dev(dev);
	devfs_debug(DEVFS_DEBUG_DEBUG,
		    "new_cdev: clearing first %d bytes\n",
		    offsetof(struct cdev, si_sysref));
	memset(dev, 0, offsetof(struct cdev, si_sysref));

	dev->si_uid = 0;
	dev->si_gid = 0;
	dev->si_perms = 0;
	dev->si_drv1 = NULL;
	dev->si_drv2 = NULL;
	dev->si_lastread = 0;		/* time_second */
	dev->si_lastwrite = 0;		/* time_second */

	dev->si_ops = ops;
	dev->si_flags = 0;
	dev->si_umajor = 0;
	dev->si_uminor = minor;
	dev->si_inode = makeudev(devfs_reference_ops(ops), minor);

	return dev;
}

static void
devfs_cdev_terminate(cdev_t dev)
{
	int locked = 0;

	/* Check if it is locked already. if not, we acquire the devfs lock */
	if (!(lockstatus(&devfs_lock, curthread)) == LK_EXCLUSIVE) {
		lockmgr(&devfs_lock, LK_EXCLUSIVE);
		locked = 1;
	}

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_cdev_terminate: Taking care of dev->si_name=%s\n", dev->si_name);

	/* Propagate destruction, just in case */
	devfs_propagate_dev(dev, 0);

	/* If we acquired the lock, we also get rid of it */
	if (locked)
		lockmgr(&devfs_lock, LK_RELEASE);

	devfs_release_ops(dev->si_ops);

	/* Finally destroy the device */
	sysref_put(&dev->si_sysref);
}

/*
 * Links a given cdev into the dev list.
 */
int
devfs_link_dev(cdev_t dev)
{
	KKASSERT((dev->si_flags & SI_DEVFS_LINKED) == 0);
	dev->si_flags |= SI_DEVFS_LINKED;
	TAILQ_INSERT_TAIL(&devfs_dev_list, dev, link);

	return 0;
}

/*
 * Removes a given cdev from the dev list.  The caller is responsible for
 * releasing the reference on the device associated with the linkage.
 *
 * Returns EALREADY if the dev has already been unlinked.
 */
static int
devfs_unlink_dev(cdev_t dev)
{
	if ((dev->si_flags & SI_DEVFS_LINKED)) {
		TAILQ_REMOVE(&devfs_dev_list, dev, link);
		dev->si_flags &= ~SI_DEVFS_LINKED;
		return (0);
	}
	return (EALREADY);
}

int
devfs_node_is_accessible(struct devfs_node *node)
{
	if ((node) && (!(node->flags & DEVFS_HIDDEN)))
		return 1;
	else
		return 0;
}

int
devfs_reference_ops(struct dev_ops *ops)
{
	int unit;

	if (ops->head.refs == 0) {
		ops->head.id = devfs_clone_bitmap_get(&DEVFS_CLONE_BITMAP(ops_id), 255);
		if (ops->head.id == -1) {
			/* Ran out of unique ids */
			kprintf("devfs_reference_ops: WARNING: ran out of unique ids\n");
		}
	}
	unit = ops->head.id;
	++ops->head.refs;

	return unit;
}

void
devfs_release_ops(struct dev_ops *ops)
{
	--ops->head.refs;

	if (ops->head.refs == 0) {
		devfs_clone_bitmap_put(&DEVFS_CLONE_BITMAP(ops_id), ops->head.id);
	}
}

void
devfs_config(void *arg)
{
	devfs_msg_t msg;

	msg = devfs_msg_get();

	kprintf("devfs_config: sync'ing up\n");
	msg = devfs_msg_send_sync(DEVFS_SYNC, msg);
	devfs_msg_put(msg);
}

/*
 * Called on init of devfs; creates the objcaches and
 * spawns off the devfs core thread. Also initializes
 * locks.
 */
static void
devfs_init(void)
{
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_init() called\n");
	/* Create objcaches for nodes, msgs and devs */
    devfs_node_cache = objcache_create("devfs-node-cache", 0, 0,
			NULL, NULL, NULL,
			objcache_malloc_alloc,
			objcache_malloc_free,
			&devfs_node_malloc_args );

    devfs_msg_cache = objcache_create("devfs-msg-cache", 0, 0,
			NULL, NULL, NULL,
			objcache_malloc_alloc,
			objcache_malloc_free,
			&devfs_msg_malloc_args );

    devfs_dev_cache = objcache_create("devfs-dev-cache", 0, 0,
			NULL, NULL, NULL,
			objcache_malloc_alloc,
			objcache_malloc_free,
			&devfs_dev_malloc_args );

	devfs_clone_bitmap_init(&DEVFS_CLONE_BITMAP(ops_id));
#if 0
	devfs_clone_bitmap_set(&DEVFS_CLONE_BITMAP(ops_id), 0);
#endif

	/* Initialize the reply-only port which acts as a message drain */
	lwkt_initport_replyonly(&devfs_dispose_port, devfs_msg_autofree_reply);

	/* Initialize *THE* devfs lock */
	lockinit(&devfs_lock, "devfs_core lock", 0, 0);


	lwkt_create(devfs_msg_core, /*args*/NULL, &td_core, NULL,
		    0, 0, "devfs_msg_core");

	tsleep(td_core/*devfs_id*/, 0, "devfsc", 0);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_init finished\n");
}

/*
 * Called on unload of devfs; takes care of destroying the core
 * and the objcaches. Also removes aliases that are no longer needed.
 */
static void
devfs_uninit(void)
{
	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs_uninit() called\n");

	devfs_msg_send(DEVFS_TERMINATE_CORE, NULL);

	tsleep(td_core/*devfs_id*/, 0, "devfsc", 0);
	tsleep(td_core/*devfs_id*/, 0, "devfsc", 10000);

	devfs_clone_bitmap_uninit(&DEVFS_CLONE_BITMAP(ops_id));

	/* Destroy the objcaches */
	objcache_destroy(devfs_msg_cache);
	objcache_destroy(devfs_node_cache);
	objcache_destroy(devfs_dev_cache);

	devfs_alias_reap();
}

/*
 * This is a sysctl handler to assist userland devname(3) to
 * find the device name for a given udev.
 */
static int
devfs_sysctl_devname_helper(SYSCTL_HANDLER_ARGS)
{
	udev_t 	udev;
	cdev_t	found;
	int		error;


	if ((error = SYSCTL_IN(req, &udev, sizeof(udev_t))))
		return (error);

	devfs_debug(DEVFS_DEBUG_DEBUG, "devfs sysctl, received udev: %d\n", udev);

	if (udev == NOUDEV)
		return(EINVAL);

	if ((found = devfs_find_device_by_udev(udev)) == NULL)
		return(ENOENT);

	return(SYSCTL_OUT(req, found->si_name, strlen(found->si_name) + 1));
}


SYSCTL_PROC(_kern, OID_AUTO, devname, CTLTYPE_OPAQUE|CTLFLAG_RW|CTLFLAG_ANYBODY,
			NULL, 0, devfs_sysctl_devname_helper, "", "helper for devname(3)");

static SYSCTL_NODE(_vfs, OID_AUTO, devfs, CTLFLAG_RW, 0, "devfs");
TUNABLE_INT("vfs.devfs.debug", &devfs_debug_enable);
SYSCTL_INT(_vfs_devfs, OID_AUTO, debug, CTLFLAG_RW, &devfs_debug_enable, 0, "Enable DevFS debugging");

SYSINIT(vfs_devfs_register, SI_SUB_PRE_DRIVERS, SI_ORDER_FIRST, devfs_init, NULL);
SYSUNINIT(vfs_devfs_register, SI_SUB_PRE_DRIVERS, SI_ORDER_ANY, devfs_uninit, NULL);