xref: /onnv-gate/usr/src/uts/common/fs/dev/sdev_comm.c (revision 6997:056043f166c6)

/*
 * CDDL HEADER START
 *
 * The contents of this file are subject to the terms of the
 * Common Development and Distribution License (the "License").
 * You may not use this file except in compliance with the License.
 *
 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE
 * or http://www.opensolaris.org/os/licensing.
 * See the License for the specific language governing permissions
 * and limitations under the License.
 *
 * When distributing Covered Code, include this CDDL HEADER in each
 * file and include the License file at usr/src/OPENSOLARIS.LICENSE.
 * If applicable, add the following below this CDDL HEADER, with the
 * fields enclosed by brackets "[]" replaced with your own identifying
 * information: Portions Copyright [yyyy] [name of copyright owner]
 *
 * CDDL HEADER END
 */
/*
 * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
 * Use is subject to license terms.
 */

#pragma ident	"%Z%%M%	%I%	%E% SMI"

/*
 * routines to invoke user level name lookup services
 */

#include <sys/types.h>
#include <sys/param.h>
#include <sys/t_lock.h>
#include <sys/systm.h>
#include <sys/sysmacros.h>
#include <sys/user.h>
#include <sys/time.h>
#include <sys/vfs.h>
#include <sys/vnode.h>
#include <sys/file.h>
#include <sys/fcntl.h>
#include <sys/flock.h>
#include <sys/kmem.h>
#include <sys/uio.h>
#include <sys/errno.h>
#include <sys/stat.h>
#include <sys/cred.h>
#include <sys/dirent.h>
#include <sys/pathname.h>
#include <sys/cmn_err.h>
#include <sys/debug.h>
#include <sys/mode.h>
#include <sys/policy.h>
#include <sys/disp.h>
#include <sys/door.h>
#include <fs/fs_subr.h>
#include <sys/mount.h>
#include <sys/fs/snode.h>
#include <sys/fs/dv_node.h>
#include <sys/fs/sdev_impl.h>
#include <sys/fs/sdev_node.h>
#include <sys/sunndi.h>
#include <sys/sunddi.h>
#include <sys/sunmdi.h>
#include <sys/conf.h>
#include <sys/modctl.h>
#include <sys/ddi.h>

/* default timeout to wait for devfsadm response in seconds */
#define	DEV_DEVFSADM_STARTUP	(1 * 60)
#define	DEV_NODE_WAIT_TIMEOUT	(5 * 60)

/* atomic bitset for devfsadm status */
volatile uint_t devfsadm_state;

static kmutex_t devfsadm_lock;
static kcondvar_t devfsadm_cv;

int devname_nsmaps_loaded = 0;
static int dev_node_wait_timeout = DEV_NODE_WAIT_TIMEOUT;
static int dev_devfsadm_startup =  DEV_DEVFSADM_STARTUP;

/*
 * Door used to communicate with devfsadmd
 */
static door_handle_t	sdev_upcall_door = NULL;	/* Door for upcalls */
static char		*sdev_door_upcall_filename = NULL;
static int		sdev_upcall_door_revoked = 0;
static int		sdev_door_upcall_filename_size;

static void sdev_devfsadmd_nsrdr(sdev_nsrdr_work_t *);
static int sdev_devfsadm_revoked(void);
static int sdev_ki_call_devfsadmd(sdev_door_arg_t *, sdev_door_res_t *);

/*
 * nsmap_readdir processing thread
 */
static uint_t			sdev_nsrdr_thread_created = 0;
static kmutex_t			sdev_nsrdr_thread_lock;
static kcondvar_t		sdev_nsrdr_thread_cv;
static sdev_nsrdr_work_t	*sdev_nsrdr_thread_workq = NULL;
static sdev_nsrdr_work_t	*sdev_nsrdr_thread_tail = NULL;

void
sdev_devfsadm_lockinit(void)
{
	mutex_init(&devfsadm_lock, NULL, MUTEX_DEFAULT, NULL);
	cv_init(&devfsadm_cv, NULL, CV_DEFAULT, NULL);
}

void
sdev_devfsadm_lockdestroy(void)
{
	mutex_destroy(&devfsadm_lock);
	cv_destroy(&devfsadm_cv);
}

/*
 * Wait for node to be created
 */
int
sdev_wait4lookup(struct sdev_node *dv, int cmd)
{
	clock_t	expire;
	clock_t rv;
	int rval = ENOENT;
	int is_lookup = (cmd == SDEV_LOOKUP);

	ASSERT(cmd == SDEV_LOOKUP || cmd == SDEV_READDIR);
	ASSERT(MUTEX_HELD(&dv->sdev_lookup_lock));

	/* tick value at which wait expires */
	expire = ddi_get_lbolt() +
	    drv_usectohz(dev_node_wait_timeout * 1000000);

	sdcmn_err6(("wait4lookup %s %s, %ld %d\n",
	    is_lookup ? "lookup" : "readdir",
	    dv->sdev_name, expire - ddi_get_lbolt(), dv->sdev_state));

	if (SDEV_IS_LGWAITING(dv)) {
		/* devfsadm nodes */
		while (DEVNAME_DEVFSADM_IS_RUNNING(devfsadm_state) &&
		    !sdev_devfsadm_revoked()) {
			/* wait 2 sec and check devfsadm completion */
			rv = cv_timedwait_sig(&dv->sdev_lookup_cv,
			    &dv->sdev_lookup_lock, ddi_get_lbolt() +
			    drv_usectohz(2 * 1000000));

			if (is_lookup && (rv > 0)) {
				/* was this node constructed ? */
				if (dv->sdev_state == SDEV_READY) {
					rval = 0;
				}
				sdcmn_err6(("%s: wait done, %screated %d\n",
				    dv->sdev_name, rval ? "not " : "",
				    dv->sdev_state));
				break;
			} else if (rv == 0) {
				/* interrupted */
				sdcmn_err6(("%s: wait interrupted\n",
				    dv->sdev_name));
				break;
			} else if ((rv == -1) &&
			    (ddi_get_lbolt() >= expire)) {
				sdcmn_err6(("%s: wait time is up\n",
					dv->sdev_name));
				break;
			}
			sdcmn_err6(("%s: wait "
			    "rv %ld state 0x%x expire %ld\n",
			    dv->sdev_name, rv, devfsadm_state,
			    expire - ddi_get_lbolt()));
		}
	} else {
		/*
		 * for the nodes created by
		 * devname_lookup_func callback
		 * or plug-in modules
		 */
		while (SDEV_IS_LOOKUP(dv) || SDEV_IS_READDIR(dv)) {
			cv_wait(&dv->sdev_lookup_cv, &dv->sdev_lookup_lock);
		}
		rval = 0;
	}

	sdcmn_err6(("wait4lookup unblocking %s state 0x%x %d\n",
	    dv->sdev_name, devfsadm_state, dv->sdev_state));

	if (is_lookup) {
		SDEV_UNBLOCK_OTHERS(dv, SDEV_LOOKUP);
	} else {
		SDEV_UNBLOCK_OTHERS(dv, SDEV_READDIR);
	}

	return (rval);
}

void
sdev_unblock_others(struct sdev_node *dv, uint_t cmd)
{
	ASSERT(MUTEX_HELD(&dv->sdev_lookup_lock));

	SDEV_CLEAR_LOOKUP_FLAGS(dv, cmd);
	if (SDEV_IS_LGWAITING(dv)) {
		SDEV_CLEAR_LOOKUP_FLAGS(dv, SDEV_LGWAITING);
	}
	cv_broadcast(&dv->sdev_lookup_cv);
}

/*
 * In the case devfsadmd is down, it is re-started by syseventd
 * upon receiving an event subscribed to by devfsadmd.
 */
static int
sdev_start_devfsadmd()
{
	int		se_err = 0;
	sysevent_t	*ev;
	sysevent_id_t	eid;

	ev = sysevent_alloc(EC_DEVFS, ESC_DEVFS_START, EP_DDI, SE_SLEEP);
	ASSERT(ev);
	if ((se_err = log_sysevent(ev, SE_SLEEP, &eid)) != 0) {
		switch (se_err) {
		case SE_NO_TRANSPORT:
			cmn_err(CE_WARN, "unable to start devfsadm - "
			    "syseventd may not be responding\n");
			break;
		default:
			cmn_err(CE_WARN, "unable to start devfsadm - "
			    "sysevent error %d\n", se_err);
			break;
		}
	}

	sysevent_free(ev);
	return (se_err);
}

static int
sdev_open_upcall_door()
{
	int error;
	clock_t rv;
	clock_t expire;

	ASSERT(sdev_upcall_door == NULL);

	/* tick value at which wait expires */
	expire = ddi_get_lbolt() +
	    drv_usectohz(dev_devfsadm_startup * 1000000);

	if (sdev_door_upcall_filename == NULL) {
		if ((error = sdev_start_devfsadmd()) != 0) {
			return (error);
		}

		/* wait for devfsadmd start */
		mutex_enter(&devfsadm_lock);
		while (sdev_door_upcall_filename == NULL) {
			sdcmn_err6(("waiting for dev_door creation, %ld\n",
			    expire - ddi_get_lbolt()));
			rv = cv_timedwait_sig(&devfsadm_cv, &devfsadm_lock,
			    expire);
			sdcmn_err6(("dev_door wait rv %ld\n", rv));
			if (rv <= 0) {
				sdcmn_err6(("devfsadmd startup error\n"));
				mutex_exit(&devfsadm_lock);
				return (EBADF);
			}
		}
		sdcmn_err6(("devfsadmd is ready\n"));
		mutex_exit(&devfsadm_lock);
	}

	if ((error = door_ki_open(sdev_door_upcall_filename,
	    &sdev_upcall_door)) != 0) {
		sdcmn_err6(("upcall_lookup: door open error %d\n",
		    error));
		return (error);
	}

	return (0);
}

static void
sdev_release_door()
{
	if (sdev_upcall_door) {
		door_ki_rele(sdev_upcall_door);
		sdev_upcall_door = NULL;
	}
	if (sdev_door_upcall_filename) {
		kmem_free(sdev_door_upcall_filename,
		    sdev_door_upcall_filename_size);
		sdev_door_upcall_filename = NULL;
	}
}

static int
sdev_ki_call_devfsadmd(sdev_door_arg_t *argp, sdev_door_res_t *resultp)
{
	door_arg_t	darg, save_arg;
	int		error;
	int		retry;

	if (((sdev_upcall_door == NULL) &&
	    ((error = sdev_open_upcall_door()) != 0)) ||
	    sdev_devfsadm_revoked()) {
		sdcmn_err6(("call_devfsadm: upcall lookup error\n"));
		return (error);
	}

	ASSERT(argp);
	darg.data_ptr = (char *)argp;
	darg.data_size = sizeof (struct sdev_door_arg);
	darg.desc_ptr = NULL;
	darg.desc_num = 0;
	darg.rbuf = (char *)(resultp);
	darg.rsize = sizeof (struct sdev_door_res);

	ASSERT(sdev_upcall_door);
	save_arg = darg;
	for (retry = 0; ; retry++) {
		sdcmn_err6(("call devfsadm: upcall lookup, retry %d\n", retry));
		if ((error = door_ki_upcall_limited(sdev_upcall_door, &darg,
		    NULL, SIZE_MAX, 0)) == 0) {
			sdcmn_err6(("call devfsadm: upcall lookup ok\n"));
			break;
		}

		/*
		 * handle door call errors
		 */
		if (sdev_devfsadm_revoked()) {
			sdcmn_err6(("upcall lookup door revoked, "
			    "error %d\n", error));
			return (error);
		}

		switch (error) {
		case EINTR:
			/* return error here? */
			sdcmn_err6(("sdev_ki_call_devfsadm: EINTR\n"));
			delay(hz);
			break;
		case EAGAIN:
			sdcmn_err6(("sdev_ki_call_devfsadm: EAGAIN\n"));
			delay(2 * hz);
			break;
		case EBADF:
			if (retry > 4) {
				sdcmn_err6(("sdev_ki_call_devfsadm: EBADF\n"));
				return (EBADF);
			}
			sdcmn_err6((
			    "sdev_ki_call_devfsadm: EBADF, re-binding\n"));
			sdev_release_door();
			delay(retry * hz);
			error = sdev_open_upcall_door();
			if (error != 0) {
				sdcmn_err6(("sdev_ki_call_devfsadm: "
				    "EBADF lookup error %d\n", error));
				if (!sdev_devfsadm_revoked())
					cmn_err(CE_NOTE,
					    "?unable to invoke devfsadm - "
					    "please run manually\n");
				return (EBADF);
			}
			break;
		case EINVAL:
		default:
			cmn_err(CE_CONT,
			    "?sdev: door_ki_upcall unexpected result %d\n",
			    error);
			return (error);
		}

		darg = save_arg;
	}

	if (!error) {
		ASSERT((struct sdev_door_res *)(intptr_t)darg.rbuf == resultp);
		if (resultp->devfsadm_error != 0) {
			sdcmn_err6(("sdev_ki_call_devfsadmd: result %d\n",
			    resultp->devfsadm_error));
			error = resultp->devfsadm_error;
		}
	} else {
		sdcmn_err6(("sdev_ki_call_devfsadmd with error %d\n", error));
	}

	return (error);
}

static int
sdev_devfsadm_revoked(void)
{
	struct door_info info;
	int rv;
	extern int sys_shutdown;

	if (sys_shutdown) {
		sdcmn_err6(("dev: shutdown observed\n"));
		return (1);
	}

	if (sdev_upcall_door && !sdev_upcall_door_revoked) {
		rv = door_ki_info(sdev_upcall_door, &info);
		if ((rv == 0) && info.di_attributes & DOOR_REVOKED) {
			sdcmn_err6(("lookup door: revoked\n"));
			sdev_upcall_door_revoked = 1;
		}
	}

	return (sdev_upcall_door_revoked);
}

/*ARGSUSED*/
static void
sdev_config_all_thread(struct sdev_node *dv)
{
	int32_t error = 0;
	sdev_door_arg_t	*argp;
	sdev_door_res_t result;

	argp = kmem_zalloc(sizeof (sdev_door_arg_t), KM_SLEEP);
	argp->devfsadm_cmd = DEVFSADMD_RUN_ALL;

	error = sdev_ki_call_devfsadmd(argp, &result);
	if (!error) {
		sdcmn_err6(("devfsadm result error: %d\n",
		    result.devfsadm_error));
		if (!result.devfsadm_error) {
			DEVNAME_DEVFSADM_SET_RUN(devfsadm_state);
		} else {
			DEVNAME_DEVFSADM_SET_STOP(devfsadm_state);
		}
	} else {
		DEVNAME_DEVFSADM_SET_STOP(devfsadm_state);
	}

	kmem_free(argp, sizeof (sdev_door_arg_t));
done:
	sdcmn_err6(("sdev_config_all_thread: stopping, devfsadm state 0x%x\n",
	    devfsadm_state));
	thread_exit();
}

/*
 * launch an asynchronous thread to do the devfsadm dev_config_all
 */
/*ARGSUSED*/
void
sdev_devfsadmd_thread(struct sdev_node *ddv, struct sdev_node *dv,
    struct cred *cred)
{
	ASSERT(i_ddi_io_initialized());
	DEVNAME_DEVFSADM_SET_RUNNING(devfsadm_state);
	(void) thread_create(NULL, 0, sdev_config_all_thread, dv, 0,
	    &p0, TS_RUN, MINCLSYSPRI);
}

int
devname_filename_register(int cmd, char *name)
{
	int error = 0;
	char *strbuf;
	char *namep;
	int n;

	ASSERT(cmd == MODDEVNAME_LOOKUPDOOR ||
	    cmd == MODDEVNAME_DEVFSADMNODE);

	strbuf = kmem_zalloc(MOD_MAXPATH, KM_SLEEP);

	if (copyinstr(name, strbuf, MOD_MAXPATH, 0)) {
		sdcmn_err6(("error copyin \n"));
		error = EFAULT;
	} else {
		sdcmn_err6(("file %s is registering\n", strbuf));
		switch (cmd) {
		case MODDEVNAME_LOOKUPDOOR:
			/* handling the daemon re-start situations */
			n = strlen(strbuf) + 1;
			namep = i_ddi_strdup(strbuf, KM_SLEEP);
			mutex_enter(&devfsadm_lock);
			sdev_release_door();
			sdev_door_upcall_filename_size = n;
			sdev_door_upcall_filename = namep;
			sdcmn_err6(("size %d file name %s\n",
			    sdev_door_upcall_filename_size,
			    sdev_door_upcall_filename));
			cv_broadcast(&devfsadm_cv);
			mutex_exit(&devfsadm_lock);
			break;
		case MODDEVNAME_DEVFSADMNODE:
			break;
		}
	}

	kmem_free(strbuf, MOD_MAXPATH);
	return (error);
}
static void
sdev_nsrdr_thread(void)
{
	sdev_nsrdr_work_t *work;

	for (;;) {
		mutex_enter(&sdev_nsrdr_thread_lock);
		if (sdev_nsrdr_thread_workq == NULL) {
			cv_wait(&sdev_nsrdr_thread_cv, &sdev_nsrdr_thread_lock);
		}
		work = sdev_nsrdr_thread_workq;
		sdev_nsrdr_thread_workq = work->next;
		if (sdev_nsrdr_thread_tail == work)
			sdev_nsrdr_thread_tail = work->next;
		mutex_exit(&sdev_nsrdr_thread_lock);
		sdev_devfsadmd_nsrdr(work);
	}
	/*NOTREACHED*/
}

int
devname_nsmaps_register(char *nvlbuf, size_t nvlsize)
{
	int error = 0;
	nvlist_t *nvl, *attrs;
	nvpair_t *nvp = NULL;
	nvpair_t *kvp = NULL;
	char *buf;
	char *key;
	char *dirname = NULL;
	char *dirmodule = NULL;
	char *dirmap = NULL;
	char *orig_module;
	char *orig_map;
	int len = 0;
	char *tmpmap;
	int mapcount = 0;

	buf = kmem_zalloc(nvlsize, KM_SLEEP);
	if ((error = ddi_copyin(nvlbuf, buf, nvlsize, 0)) != 0) {
		kmem_free(buf, nvlsize);
		return (error);
	}

	ASSERT(buf);
	sdcmn_err6(("devname_nsmaps_register: nsmap buf %p\n", (void *)buf));
	nvl = NULL;
	error = nvlist_unpack(buf, nvlsize, &nvl, KM_SLEEP);
	kmem_free(buf, nvlsize);
	if (error || (nvl == NULL))
		return (error);

	/* invalidate all the nsmaps */
	mutex_enter(&devname_nsmaps_lock);
	sdev_invalidate_nsmaps();
	for (nvp = nvlist_next_nvpair(nvl, NULL); nvp != NULL;
	    nvp = nvlist_next_nvpair(nvl, nvp)) {
		dirname = nvpair_name(nvp);
		if (dirname == NULL) {
			nvlist_free(nvl);
			mutex_exit(&devname_nsmaps_lock);
			return (-1);
		}

		sdcmn_err6(("dirname %s\n", dirname));
		(void) nvpair_value_nvlist(nvp, &attrs);
		for (kvp = nvlist_next_nvpair(attrs, NULL); kvp;
		    kvp = nvlist_next_nvpair(attrs, kvp)) {
			key = nvpair_name(kvp);
			sdcmn_err6(("key %s\n", key));
			if (strcmp(key, "module") == 0) {
				(void) nvpair_value_string(kvp, &orig_module);
				sdcmn_err6(("module %s\n", orig_module));
				dirmodule = i_ddi_strdup(orig_module, KM_SLEEP);
				if (strcmp(dirmodule, "devname_null") == 0)
					dirmodule = NULL;
			}

			if (strcmp(key, "nsconfig") == 0) {
				(void) nvpair_value_string(kvp, &orig_map);
				sdcmn_err6(("dirmap %s\n", orig_map));
				dirmap = i_ddi_strdup(orig_map, KM_SLEEP);
				if (strcmp(dirmap, "devname_null") == 0)
					dirmap = NULL;
				else if (dirmap[0] != '/') {
					len = strlen(dirmap) +
					    strlen(ETC_DEV_DIR) + 2;
					tmpmap = i_ddi_strdup(dirmap, KM_SLEEP);
					(void) snprintf(dirmap, len, "%s/%s",
					    ETC_DEV_DIR, tmpmap);
					kmem_free(tmpmap, strlen(tmpmap) + 1);
				}
			}
		}

		if (dirmodule == NULL && dirmap == NULL) {
			nvlist_free(nvl);
			mutex_exit(&devname_nsmaps_lock);
			return (-1);
		}

		sdcmn_err6(("sdev_nsmaps_register: dir %s module %s map %s\n",
		    dirname, dirmodule, dirmap));
		sdev_insert_nsmap(dirname, dirmodule, dirmap);
		mapcount++;
	}

	if (mapcount > 0)
		devname_nsmaps_loaded = 1;

	/* clean up obsolete nsmaps */
	sdev_validate_nsmaps();
	mutex_exit(&devname_nsmaps_lock);
	if (nvl)
		nvlist_free(nvl);

	if (sdev_nsrdr_thread_created) {
		return (0);
	}

	mutex_init(&sdev_nsrdr_thread_lock, NULL, MUTEX_DEFAULT, NULL);
	cv_init(&sdev_nsrdr_thread_cv, NULL, CV_DEFAULT, NULL);
	(void) thread_create(NULL, 0, (void (*)())sdev_nsrdr_thread, NULL, 0,
	    &p0, TS_RUN, minclsyspri);
	sdev_nsrdr_thread_created = 1;

	return (0);
}

void
sdev_dispatch_to_nsrdr_thread(struct sdev_node *ddv, char *dir_map,
    devname_rdr_result_t *result)
{
	sdev_nsrdr_work_t *new_work;

	new_work = kmem_zalloc(sizeof (sdev_nsrdr_work_t), KM_SLEEP);
	new_work->dir_name = i_ddi_strdup(ddv->sdev_name, KM_SLEEP);
	new_work->dir_map = i_ddi_strdup(dir_map, KM_SLEEP);
	new_work->dir_dv = ddv;
	new_work->result = &result;
	mutex_enter(&sdev_nsrdr_thread_lock);
	if (sdev_nsrdr_thread_workq == NULL) {
		sdev_nsrdr_thread_workq = new_work;
		sdev_nsrdr_thread_tail = new_work;
		new_work->next = NULL;
	} else {
		sdev_nsrdr_thread_tail->next = new_work;
		sdev_nsrdr_thread_tail = new_work;
		new_work->next = NULL;
	}
	cv_signal(&sdev_nsrdr_thread_cv);
	mutex_exit(&sdev_nsrdr_thread_lock);
}

static void
sdev_devfsadmd_nsrdr(sdev_nsrdr_work_t *work)
{
	int32_t error;
	struct sdev_door_arg *argp;
	struct sdev_door_res res;
	struct sdev_node *ddv = work->dir_dv;
	uint32_t mapcount;

	argp = kmem_zalloc(sizeof (sdev_door_arg_t), KM_SLEEP);
	argp->devfsadm_cmd = DEVFSADMD_NS_READDIR;

	(void) snprintf(argp->ns_hdl.ns_name,
	    strlen(work->dir_dv->sdev_path) + 1, "%s", work->dir_dv->sdev_path);
	(void) snprintf(argp->ns_hdl.ns_map, strlen(work->dir_map) + 1, "%s",
	    work->dir_map);

	sdcmn_err6(("sdev_devfsadmd_nsrdr: ns_name %s, ns_map %s\n",
	    argp->ns_hdl.ns_name, argp->ns_hdl.ns_map));
	error = sdev_ki_call_devfsadmd(argp, &res);
	sdcmn_err6(("sdev_devfsadmd_nsrdr error %d\n", error));
	if (error == 0) {
		error = res.devfsadm_error;
		if (error) {
			goto out;
		}

		mapcount = (uint32_t)res.ns_rdr_hdl.ns_mapcount;
		sdcmn_err6(("nsmapcount %d\n", mapcount));
		if (mapcount > 0) {
			struct devname_nsmap *map =
			    ddv->sdev_mapinfo;
			ASSERT(map && map->dir_map);
			rw_enter(&map->dir_lock, RW_WRITER);
			map->dir_maploaded = 1;
			rw_exit(&map->dir_lock);
		}
	}

out:
	mutex_enter(&ddv->sdev_lookup_lock);
	SDEV_UNBLOCK_OTHERS(ddv, SDEV_READDIR);
	mutex_exit(&ddv->sdev_lookup_lock);

	kmem_free(argp, sizeof (sdev_door_arg_t));
}


int
devname_nsmap_lookup(devname_lkp_arg_t *args, devname_lkp_result_t **result)
{
	int32_t error = 0;
	struct sdev_door_arg *argp;
	struct sdev_door_res resp;
	char *link;
	devname_spec_t spec;

	argp = kmem_zalloc(sizeof (sdev_door_arg_t), KM_SLEEP);
	argp->devfsadm_cmd = DEVFSADMD_NS_LOOKUP;

	(void) snprintf(argp->ns_hdl.ns_name, strlen(args->devname_name) + 1,
	    "%s", args->devname_name);
	(void) snprintf(argp->ns_hdl.ns_map, strlen(args->devname_map) + 1,
	    "%s", args->devname_map);

	error = sdev_ki_call_devfsadmd(argp, &resp);
	if (error == 0) {
		error = resp.devfsadm_error;
		sdcmn_err6(("devfsadm: error %d\n", error));
		if (error) {
			goto done;
		}
		link = resp.ns_lkp_hdl.devfsadm_link;
		if (link == NULL) {
			error = ENOENT;
			goto done;
		}
		spec = resp.ns_lkp_hdl.devfsadm_spec;
		sdcmn_err6(("devfsadm_link %s spec %d\n",
		    link, (int)spec));


		(*result)->devname_spec = (devname_spec_t)spec;
		(*result)->devname_link = i_ddi_strdup(link, KM_SLEEP);
	} else {
		(*result)->devname_spec = DEVNAME_NS_NONE;
		(*result)->devname_link = NULL;
	}
done:
	kmem_free(argp, sizeof (sdev_door_arg_t));
	return (error);
}