fs/dev/sdev_comm.c

	sdev_comm.c revision facf4a8d7b59fde89a8662b4f4c73a758e6c402c
/*
 * 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 2006 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(sdev_upcall_door, &darg)) == 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 *)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;
    uint8_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, 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);
}