freebsd/sbin/vinum/v.c

/* vinum.c: vinum interface program */
/*-
 * Copyright (c) 1997, 1998
 *	Nan Yang Computer Services Limited.  All rights reserved.
 *
 *  Written by Greg Lehey
 *
 *  This software is distributed under the so-called ``Berkeley
 *  License'':
 *
 * 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. All advertising materials mentioning features or use of this software
 *    must display the following acknowledgement:
 *	This product includes software developed by Nan Yang Computer
 *      Services Limited.
 * 4. Neither the name of the Company 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 ``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 company 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.
 *
 * $Id: v.c,v 1.27 1999/10/12 05:41:10 grog Exp grog $
 * $FreeBSD$
 */

#include <ctype.h>
#include <errno.h>
#include <fcntl.h>
#include <sys/mman.h>
#include <libutil.h>
#include <netdb.h>
#include <setjmp.h>
#include <signal.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <syslog.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <dev/vinum/vinumhdr.h>
#include "vext.h"
#include <sys/types.h>
#include <sys/wait.h>
#include <readline/history.h>
#include <readline/readline.h>
#include <sys/linker.h>
#include <sys/module.h>
#include <sys/resource.h>

FILE *cf;						    /* config file handle */
FILE *history;						    /* history file */
char *historyfile;					    /* and its name */

char *dateformat;					    /* format in which to store date */

char buffer[BUFSIZE];					    /* buffer to read in to */

int line = 0;						    /* stdin line number for error messages */
int file_line = 0;					    /* and line in input file (yes, this is tacky) */
int inerror;						    /* set to 1 to exit after end of config file */

/* flags */

#if VINUMDEBUG
int debug = 0;						    /* debug flag, usage varies */
#endif
int force = 0;						    /* set to 1 to force some dangerous ops */
int vflag = 0;						    /* set verbose operation or verify */
int Verbose = 0;					    /* set very verbose operation */
int recurse = 0;					    /* set recursion */
int sflag = 0;						    /* show statistics */
int SSize = 0;						    /* sector size for revive */
int dowait = 0;						    /* wait for completion */
char *objectname;					    /* name to be passed for -n flag */

/* Structures to read kernel data into */
struct _vinum_conf vinum_conf;				    /* configuration information */

struct volume vol;
struct plex plex;
struct sd sd;
struct drive drive;

jmp_buf command_fail;					    /* return on a failed command */
int superdev;						    /* vinum super device */

void start_daemon(void);

#define ofs(x) ((void *) (& ((struct confdata *) 0)->x))    /* offset of x in struct confdata */

char *token[MAXARGS];					    /* pointers to individual tokens */
int tokens;						    /* number of tokens */

int
main(int argc, char *argv[], char *envp[])
{
    if (modfind(VINUMMOD) < 0) {
	/* need to load the vinum module */
	if (kldload(VINUMMOD) < 0 || modfind(VINUMMOD) < 0) {
	    perror(VINUMMOD ": Kernel module not available");
	    return 1;
	}
    }
    dateformat = getenv("VINUM_DATEFORMAT");
    if (dateformat == NULL)
	dateformat = "%e %b %Y %H:%M:%S";
    historyfile = getenv("VINUM_HISTORY");
    if (historyfile == NULL)
	historyfile = DEFAULT_HISTORYFILE;
    history = fopen(historyfile, "a+");
    if (history != NULL) {
	timestamp();
	fprintf(history, "*** " VINUMMOD " started ***\n");
	fflush(history);				    /* before we start the daemon */
    }
    superdev = open(VINUM_SUPERDEV_NAME, O_RDWR);	    /* open vinum superdevice */
    if (superdev < 0) {					    /* no go */
	if (errno == ENODEV) {				    /* not configured, */
	    superdev = open(VINUM_WRONGSUPERDEV_NAME, O_RDWR); /* do we have a debug mismatch? */
	    if (superdev >= 0) {			    /* yup! */
#if VINUMDEBUG
		fprintf(stderr,
		    "This program is compiled with debug support, but the kernel module does\n"
		    "not have debug support.  This program must be matched with the kernel\n"
		    "module.  Please alter /usr/src/sbin/" VINUMMOD "/Makefile and remove\n"
		    "the option -DVINUMDEBUG from the CFLAGS definition, or alternatively\n"
		    "edit /usr/src/sys/modules/" VINUMMOD "/Makefile and add the option\n"
		    "-DVINUMDEBUG to the CFLAGS definition.  Then rebuild the component\n"
		    "of your choice with 'make clean all install'.  If you rebuild the kernel\n"
		    "module, you must stop " VINUMMOD " and restart it\n");
#else
		fprintf(stderr,
		    "This program is compiled without debug support, but the kernel module\n"
		    "includes debug support.  This program must be matched with the kernel\n"
		    "module.  Please alter /usr/src/sbin/" VINUMMOD "/Makefile and add\n"
		    "the option -DVINUMDEBUG to the CFLAGS definition, or alternatively\n"
		    "edit /usr/src/sys/modules/" VINUMMOD "/Makefile and remove the option\n"
		    "-DVINUMDEBUG from the CFLAGS definition.  Then rebuild the component\n"
		    "of your choice with 'make clean all install'.  If you rebuild the kernel\n"
		    "module, you must stop " VINUMMOD " and restart it\n");
#endif
		return 1;
	    }
	} else if (errno == ENOENT)			    /* we don't have our node, */
	    make_devices();				    /* create them first */
	if (superdev < 0) {
	    perror("Can't open " VINUM_SUPERDEV_NAME);
	    return 1;
	}
    }
    /* Check if the d<>mon is running.  If not, start it in the
     * background */
    start_daemon();

    if (argc > 1) {					    /* we have a command on the line */
	if (setjmp(command_fail) != 0)			    /* long jumped out */
	    return -1;
	parseline(argc - 1, &argv[1]);			    /* do it */
    } else {
	for (;;) {					    /* ugh */
	    char *c;
	    int childstatus;				    /* from wait4 */

	    setjmp(command_fail);			    /* come back here on catastrophic failure */

	    while (wait4(-1, &childstatus, WNOHANG, NULL) > 0);	/* wait for all dead children */
	    c = readline(VINUMMOD " -> ");		    /* get an input */
	    if (c == NULL) {				    /* EOF or error */
		if (ferror(stdin)) {
		    fprintf(stderr, "Can't read input: %s (%d)\n", strerror(errno), errno);
		    return 1;
		} else {				    /* EOF */
		    printf("\n");
		    return 0;
		}
	    } else if (*c) {				    /* got something there */
		add_history(c);				    /* save it in the history */
		strcpy(buffer, c);			    /* put it where we can munge it */
		free(c);
		line++;					    /* count the lines */
		tokens = tokenize(buffer, token);
		/* got something potentially worth parsing */
		if (tokens)
		    parseline(tokens, token);		    /* and do what he says */
	    }
	    if (history)
		fflush(history);
	}
    }
    return 0;						    /* normal completion */
}

/* stop the hard way */
void
vinum_quit(int argc, char *argv[], char *argv0[])
{
    exit(0);
}

#define FUNKEY(x) { kw_##x, &vinum_##x }		    /* create pair "kw_foo", vinum_foo */
#define vinum_move vinum_mv				    /* synonym for 'mv' */

struct funkey {
    enum keyword kw;
    void (*fun) (int argc, char *argv[], char *arg0[]);
} funkeys[] = {

    FUNKEY(create),
	FUNKEY(read),
#ifdef VINUMDEBUG
	FUNKEY(debug),
#endif
	FUNKEY(modify),
	FUNKEY(list),
	FUNKEY(ld),
	FUNKEY(ls),
	FUNKEY(lp),
	FUNKEY(lv),
	FUNKEY(info),
	FUNKEY(set),
	FUNKEY(init),
	FUNKEY(label),
	FUNKEY(resetconfig),
	FUNKEY(rm),
	FUNKEY(mv),
	FUNKEY(move),
	FUNKEY(attach),
	FUNKEY(detach),
	FUNKEY(rename),
	FUNKEY(replace),
	FUNKEY(printconfig),
	FUNKEY(saveconfig),
	FUNKEY(start),
	FUNKEY(stop),
	FUNKEY(makedev),
	FUNKEY(help),
	FUNKEY(quit),
	FUNKEY(concat),
	FUNKEY(stripe),
	FUNKEY(raid4),
	FUNKEY(raid5),
	FUNKEY(mirror),
	FUNKEY(setdaemon),
	FUNKEY(readpol),
	FUNKEY(resetstats),
	FUNKEY(setstate),
	FUNKEY(checkparity),
	FUNKEY(rebuildparity)
};

/* Take args arguments at argv and attempt to perform the operation specified */
void
parseline(int args, char *argv[])
{
    int i;
    int j;
    enum keyword command;				    /* command to execute */

    if (history != NULL) {				    /* save the command to history file */
	timestamp();
	for (i = 0; i < args; i++)			    /* all args */
	    fprintf(history, "%s ", argv[i]);
	fputs("\n", history);
    }
    if ((args == 0)					    /* empty line */
    ||(*argv[0] == '#'))				    /* or a comment, */
	return;
    if (args == MAXARGS) {				    /* too many arguments, */
	fprintf(stderr, "Too many arguments to %s, this can't be right\n", argv[0]);
	return;
    }
    command = get_keyword(argv[0], &keyword_set);
    dowait = 0;						    /* initialize flags */
    force = 0;						    /* initialize flags */
    vflag = 0;						    /* initialize flags */
    Verbose = 0;					    /* initialize flags */
    recurse = 0;					    /* initialize flags */
    sflag = 0;						    /* initialize flags */
    objectname = NULL;					    /* no name yet */

    /*
     * first handle generic options
     * We don't use getopt(3) because
     * getopt doesn't allow merging flags
     * (for example, -fr).
     */
    for (i = 1; (i < args) && (argv[i][0] == '-'); i++) {   /* while we have flags */
	for (j = 1; j < strlen(argv[i]); j++)
	    switch (argv[i][j]) {
#if VINUMDEBUG
	    case 'd':					    /* -d: debug */
		debug = 1;
		break;
#endif

	    case 'f':					    /* -f: force */
		force = 1;
		break;

	    case 'n':					    /* -n: get name */
		if (i == args - 1) {			    /* last arg */
		    fprintf(stderr, "-n requires a name parameter\n");
		    return;
		}
		objectname = argv[++i];			    /* pick it up */
		j = strlen(argv[i]);			    /* skip the next parm */
		break;

	    case 'r':					    /* -r: recurse */
		recurse = 1;
		break;

	    case 's':					    /* -s: show statistics */
		sflag = 1;
		break;

	    case 'S':
		SSize = 0;
		if (argv[i][j + 1] != '\0')		    /* operand follows, */
		    SSize = atoi(&argv[i][j + 1]);	    /* use it */
		else if (args > (i + 1))		    /* another following, */
		    SSize = atoi(argv[++i]);		    /* use it */
		if (SSize == 0)				    /* nothing valid, */
		    fprintf(stderr, "-S: no size specified\n");
		break;

	    case 'v':					    /* -v: verbose */
		vflag++;
		break;

	    case 'V':					    /* -V: Very verbose */
		vflag++;
		Verbose++;
		break;

	    case 'w':					    /* -w: wait for completion */
		dowait = 1;
		break;

	    default:
		fprintf(stderr, "Invalid flag: %s\n", argv[i]);
	    }
    }

    /* Pass what we have left to the command to handle it */
    for (j = 0; j < (sizeof(funkeys) / sizeof(struct funkey)); j++) {
	if (funkeys[j].kw == command) {			    /* found the command */
	    funkeys[j].fun(args - i, &argv[i], &argv[0]);
	    return;
	}
    }
    fprintf(stderr, "Unknown command: %s\n", argv[0]);
}

void
get_drive_info(struct drive *drive, int index)
{
    *(int *) drive = index;				    /* put in drive to hand to driver */
    if (ioctl(superdev, VINUM_DRIVECONFIG, drive) < 0) {
	fprintf(stderr,
	    "Can't get config for drive %d: %s\n",
	    index,
	    strerror(errno));
	longjmp(command_fail, -1);
    }
}

void
get_sd_info(struct sd *sd, int index)
{
    *(int *) sd = index;				    /* put in sd to hand to driver */
    if (ioctl(superdev, VINUM_SDCONFIG, sd) < 0) {
	fprintf(stderr,
	    "Can't get config for subdisk %d: %s\n",
	    index,
	    strerror(errno));
	longjmp(command_fail, -1);
    }
}

/* Get the contents of the sd entry for subdisk <sdno>
 * of the specified plex. */
void
get_plex_sd_info(struct sd *sd, int plexno, int sdno)
{
    ((int *) sd)[0] = plexno;
    ((int *) sd)[1] = sdno;				    /* pass parameters */
    if (ioctl(superdev, VINUM_PLEXSDCONFIG, sd) < 0) {
	fprintf(stderr,
	    "Can't get config for subdisk %d (part of plex %d): %s\n",
	    sdno,
	    plexno,
	    strerror(errno));
	longjmp(command_fail, -1);
    }
}

void
get_plex_info(struct plex *plex, int index)
{
    *(int *) plex = index;				    /* put in plex to hand to driver */
    if (ioctl(superdev, VINUM_PLEXCONFIG, plex) < 0) {
	fprintf(stderr,
	    "Can't get config for plex %d: %s\n",
	    index,
	    strerror(errno));
	longjmp(command_fail, -1);
    }
}

void
get_volume_info(struct volume *volume, int index)
{
    *(int *) volume = index;				    /* put in volume to hand to driver */
    if (ioctl(superdev, VINUM_VOLCONFIG, volume) < 0) {
	fprintf(stderr,
	    "Can't get config for volume %d: %s\n",
	    index,
	    strerror(errno));
	longjmp(command_fail, -1);
    }
}

struct drive *
find_drive_by_devname(char *name)
{
    int driveno;

    if (ioctl(superdev, VINUM_GETCONFIG, &vinum_conf) < 0) {
	perror("Can't get vinum config");
	return NULL;
    }
    for (driveno = 0; driveno < vinum_conf.drives_allocated; driveno++) {
	get_drive_info(&drive, driveno);
	if ((drive.state != drive_unallocated)		    /* real drive */
	&&(!strcmp(drive.devicename, name)))		    /* and the name's right, */
	    return &drive;				    /* found it */
    }
    return NULL;					    /* no drive of that name */
}

/* Create the device nodes for vinum objects */
void
make_devices(void)
{
    int volno;
    int plexno;
    int sdno;
    int driveno;

    if (access("/dev", W_OK) < 0) {			    /* can't access /dev to write? */
	if (errno == EROFS)				    /* because it's read-only, */
	    fprintf(stderr, VINUMMOD ": /dev is mounted read-only, not rebuilding " VINUM_DIR "\n");
	else
	    perror(VINUMMOD ": Can't write to /dev");
	return;
    }
    if (history) {
	timestamp();
	fprintf(history, "*** Created devices ***\n");
    }
    if (superdev >= 0)					    /* super device open */
	close(superdev);

    system("rm -rf " VINUM_DIR);			    /* remove the old directories */
    system("mkdir -p " VINUM_DIR "/drive "		    /* and make them again */
	VINUM_DIR "/plex "
	VINUM_DIR "/sd "
	VINUM_DIR "/vol ");

    if (mknod(VINUM_SUPERDEV_NAME,
	    S_IRUSR | S_IWUSR | S_IFCHR,		    /* user only */
	    makedev(VINUM_CDEV_MAJOR, VINUM_SUPERDEV)) < 0)
	fprintf(stderr, "Can't create %s: %s\n", VINUM_SUPERDEV_NAME, strerror(errno));

    if (mknod(VINUM_WRONGSUPERDEV_NAME,
	    S_IRUSR | S_IWUSR | S_IFCHR,		    /* user only */
	    makedev(VINUM_CDEV_MAJOR, VINUM_WRONGSUPERDEV)) < 0)
	fprintf(stderr, "Can't create %s: %s\n", VINUM_WRONGSUPERDEV_NAME, strerror(errno));

    superdev = open(VINUM_SUPERDEV_NAME, O_RDWR);	    /* open the super device */

    if (mknod(VINUM_DAEMON_DEV_NAME,			    /* daemon super device */
	    S_IRUSR | S_IWUSR | S_IFCHR,		    /* user only */
	    makedev(VINUM_CDEV_MAJOR, VINUM_DAEMON_DEV)) < 0)
	fprintf(stderr, "Can't create %s: %s\n", VINUM_DAEMON_DEV_NAME, strerror(errno));

    if (ioctl(superdev, VINUM_GETCONFIG, &vinum_conf) < 0) {
	perror("Can't get vinum config");
	return;
    }
    for (volno = 0; volno < vinum_conf.volumes_allocated; volno++)
	make_vol_dev(volno, 0);

    for (plexno = 0; plexno < vinum_conf.plexes_allocated; plexno++)
	make_plex_dev(plexno, 0);

    for (sdno = 0; sdno < vinum_conf.subdisks_allocated; sdno++)
	make_sd_dev(sdno);

    /* Drives.  Do this later (both logical and physical names) XXX */
    for (driveno = 0; driveno < vinum_conf.drives_allocated; driveno++) {
	char filename[PATH_MAX];			    /* for forming file names */

	get_drive_info(&drive, driveno);
	if (drive.state > drive_referenced) {
	    sprintf(filename, "ln -s %s " VINUM_DIR "/drive/%s", drive.devicename, drive.label.name);
	    system(filename);
	}
    }
}

/* make the devices for a volume */
void
make_vol_dev(int volno, int recurse)
{
    dev_t voldev;
    char filename[PATH_MAX];				    /* for forming file names */
    int plexno;

    get_volume_info(&vol, volno);
    if (vol.state != volume_unallocated) {		    /* we could have holes in our lists */
	voldev = VINUMDEV(volno, 0, 0, VINUM_VOLUME_TYPE);  /* create a device number */

	/* Create /dev/vinum/<myvol> */
	sprintf(filename, VINUM_DIR "/%s", vol.name);
	if (mknod(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR, voldev) < 0)
	    fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));

	/* Create /dev/vinum/vol/<myvol> */
	sprintf(filename, VINUM_DIR "/vol/%s", vol.name);
	if (mknod(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR, voldev) < 0)
	    fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));

	if (vol.plexes > 0) {
	    /* Create /dev/vinum/vol/<myvol>.plex/ */
	    sprintf(filename, VINUM_DIR "/vol/%s.plex", vol.name);
	    if (mkdir(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IXOTH) < 0)
		fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));
	}
	if (recurse)
	    for (plexno = 0; plexno < vol.plexes; plexno++)
		make_plex_dev(plex.plexno, recurse);
    }
}

/*
 * Create device entries for the plexes in
 * /dev/vinum/<vol>.plex/ and /dev/vinum/plex.
 */
void
make_plex_dev(int plexno, int recurse)
{
    dev_t plexdev;					    /* device */
    char filename[PATH_MAX];				    /* for forming file names */
    int sdno;

    get_plex_info(&plex, plexno);
    if (plex.state != plex_unallocated) {
	plexdev = VINUM_PLEX(plexno);

	/* /dev/vinum/plex/<plex> */
	sprintf(filename, VINUM_DIR "/plex/%s", plex.name);
	if (mknod(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR, plexdev) < 0)
	    fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));

	if (plex.volno >= 0) {
	    get_volume_info(&vol, plex.volno);
	    plexdev = VINUMDEV(plex.volno, plexno, 0, VINUM_PLEX_TYPE);

	    /* Create device /dev/vinum/vol/<vol>.plex/<plex> */
	    sprintf(filename, VINUM_DIR "/vol/%s.plex/%s", vol.name, plex.name);
	    if (mknod(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR, plexdev) < 0)
		fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));

	    /* Create directory /dev/vinum/vol/<vol>.plex/<plex>.sd */
	    sprintf(filename, VINUM_DIR "/vol/%s.plex/%s.sd", vol.name, plex.name);
	    if (mkdir(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IXOTH) < 0)
		fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));
	}
	if (recurse) {
	    for (sdno = 0; sdno < plex.subdisks; sdno++) {
		get_plex_sd_info(&sd, plex.plexno, sdno);
		make_sd_dev(sd.sdno);
	    }
	}
    }
}

/* Create the contents of /dev/vinum/sd and /dev/vinum/rsd */
void
make_sd_dev(int sdno)
{
    dev_t sddev;					    /* device */
    char filename[PATH_MAX];				    /* for forming file names */

    get_sd_info(&sd, sdno);
    if (sd.state != sd_unallocated) {
	sddev = VINUM_SD(sdno);

	/* /dev/vinum/sd/<sd> */
	sprintf(filename, VINUM_DIR "/sd/%s", sd.name);
	if (mknod(filename, S_IRUSR | S_IWUSR | S_IRGRP | S_IFCHR, sddev) < 0)
	    fprintf(stderr, "Can't create %s: %s\n", filename, strerror(errno));
    }
}

/* command line interface for the 'makedev' command */
void
vinum_makedev(int argc, char *argv[], char *arg0[])
{
    make_devices();
}

/*
 * Find the object "name".  Return object type at type,
 * and the index as the return value.
 * If not found, return -1 and invalid_object.
 */
int
find_object(const char *name, enum objecttype *type)
{
    int object;

    if (ioctl(superdev, VINUM_GETCONFIG, &vinum_conf) < 0) {
	perror("Can't get vinum config");
	*type = invalid_object;
	return -1;
    }
    /* Search the drive table */
    for (object = 0; object < vinum_conf.drives_allocated; object++) {
	get_drive_info(&drive, object);
	if (strcmp(name, drive.label.name) == 0) {
	    *type = drive_object;
	    return object;
	}
    }

    /* Search the subdisk table */
    for (object = 0; object < vinum_conf.subdisks_allocated; object++) {
	get_sd_info(&sd, object);
	if (strcmp(name, sd.name) == 0) {
	    *type = sd_object;
	    return object;
	}
    }

    /* Search the plex table */
    for (object = 0; object < vinum_conf.plexes_allocated; object++) {
	get_plex_info(&plex, object);
	if (strcmp(name, plex.name) == 0) {
	    *type = plex_object;
	    return object;
	}
    }

    /* Search the volume table */
    for (object = 0; object < vinum_conf.volumes_allocated; object++) {
	get_volume_info(&vol, object);
	if (strcmp(name, vol.name) == 0) {
	    *type = volume_object;
	    return object;
	}
    }

    /* Didn't find the name: invalid */
    *type = invalid_object;
    return -1;
}

/* Continue reviving a subdisk in the background */
void
continue_revive(int sdno)
{
    struct sd sd;
    pid_t pid;
    get_sd_info(&sd, sdno);

    if (dowait == 0)
	pid = fork();					    /* do this in the background */
    else
	pid = 0;
    if (pid == 0) {					    /* we're the child */
	struct _ioctl_reply reply;
	struct vinum_ioctl_msg *message = (struct vinum_ioctl_msg *) &reply;

	openlog(VINUMMOD, LOG_CONS | LOG_PERROR | LOG_PID, LOG_KERN);
	syslog(LOG_INFO | LOG_KERN, "reviving %s", sd.name);
	setproctitle("reviving %s", sd.name);

	for (reply.error = EAGAIN; reply.error == EAGAIN;) { /* revive the subdisk */
	    message->index = sdno;			    /* pass sd number */
	    message->type = sd_object;			    /* and type of object */
	    message->state = object_up;
	    ioctl(superdev, VINUM_SETSTATE, message);
	}
	if (reply.error) {
	    syslog(LOG_ERR | LOG_KERN,
		"can't revive %s: %s",
		sd.name,
		reply.msg[0] ? reply.msg : strerror(reply.error));
	    if (dowait == 0)
		exit(1);
	} else {
	    get_sd_info(&sd, sdno);			    /* update the info */
	    syslog(LOG_INFO | LOG_KERN, "%s is %s", sd.name, sd_state(sd.state));
	    if (dowait == 0)
		exit(0);
	}
    } else if (pid < 0)					    /* couldn't fork? */
	fprintf(stderr, "Can't continue reviving %s: %s\n", sd.name, strerror(errno));
    else
	printf("Reviving %s in the background\n", sd.name);
}

/*
 * Check if the daemon is running,
 * start it if it isn't.  The check itself
 * could take a while, so we do it as a separate
 * process, which will become the daemon if one isn't
 * running already
 */
void
start_daemon(void)
{
    int pid;
    int status;
    int error;

    pid = (int) fork();

    if (pid == 0) {					    /* We're the child, do the work */
	/*
	 * We have a problem when stopping the subsystem:
	 * The only way to know that we're idle is when
	 * all open superdevs close.  But we want the
	 * daemon to clean up for us, and since we can't
	 * count the opens, we need to have the main device
	 * closed when we stop.  We solve this conundrum
	 * by getting the daemon to open a separate device.
	 */
	close(superdev);				    /* this is the wrong device */
	superdev = open(VINUM_DAEMON_DEV_NAME, O_RDWR);	    /* open deamon superdevice */
	if (superdev < 0) {
	    perror("Can't open " VINUM_DAEMON_DEV_NAME);
	    exit(1);
	}
	error = daemon(0, 0);				    /* this will fork again, but who's counting? */
	if (error != 0) {
	    fprintf(stderr, "Can't start daemon: %s (%d)\n", strerror(errno), errno);
	    exit(1);
	}
	setproctitle(VINUMMOD " daemon");		    /* show what we're doing */
	status = ioctl(superdev, VINUM_FINDDAEMON, NULL);
	if (status != 0) {				    /* no daemon, */
	    ioctl(superdev, VINUM_DAEMON, &vflag);	    /* we should hang here */
	    syslog(LOG_ERR | LOG_KERN, "%s", strerror(errno));
	    exit(1);
	}
	exit(0);					    /* when told to die */
    } else if (pid < 0)					    /* couldn't fork */
	printf("Can't fork to check daemon\n");
}

void
timestamp()
{
    struct timeval now;
    struct tm *date;
    char datetext[MAXDATETEXT];
    time_t sec;

    if (history != NULL) {
	if (gettimeofday(&now, NULL) != 0) {
	    fprintf(stderr, "Can't get time: %s\n", strerror(errno));
	    return;
	}
	sec = now.tv_sec;
	date = localtime(&sec);
	strftime(datetext, MAXDATETEXT, dateformat, date),
	    fprintf(history,
	    "%s.%06ld ",
	    datetext,
	    now.tv_usec);
    }
}