vinumio.c

来自「基于组件方式开发操作系统的OSKIT源代码」· C语言 代码 · 共 1,103 行 · 第 1/3 页

	if (error) {
	    brelse(bp);
	    return error;
	}
	error = uiomove((char *) bp->b_data + blockoff, count, &uio); /* move the data */
	brelse(bp);
    }
    while (error == 0 && uio.uio_resid > 0 && count != 0);
    return error;
}

/*
 * Write data to a drive
 *
 * Return error number
 */
int 
write_drive(struct drive *drive, void *buf, size_t length, off_t offset)
{
    int error;
    struct buf *bp;
    struct uio uio;
    struct iovec iov;
    daddr_t blocknum;					    /* block number */
    int blockoff;					    /* offset in block */
    int count;						    /* amount to transfer */
    int blockshift;

    if (drive->state == drive_down)			    /* currently down */
	return 0;					    /* ignore */
    if (drive->vp == NULL) {
	drive->lasterror = ENODEV;
	return ENODEV;					    /* not configured yet */
    }
    iov.iov_base = buf;
    iov.iov_len = length;

    uio.uio_iov = &iov;
    uio.uio_iovcnt = length;
    uio.uio_offset = offset;
    uio.uio_resid = length;
    uio.uio_segflg = UIO_SYSSPACE;
    uio.uio_rw = UIO_WRITE;
    uio.uio_procp = curproc;

    error = 0;
    blockshift = btodb(drive->blocksize) - 1;		    /* amount to shift block number
							    * to get sector number */
    do {
	blocknum = btodb(uio.uio_offset) & ~blockshift;	    /* get the block number */
	blockoff = uio.uio_offset % drive->blocksize;	    /* offset in block */
	count = min((unsigned) (drive->blocksize - blockoff), /* amount to transfer in this block */
	    uio.uio_resid);
	if (count == drive->blocksize)			    /* the whole block */
	    bp = getblk(drive->vp, blocknum, drive->blocksize, 0, 0); /* just transfer it */
	else						    /* partial block: */
	    error = bread(drive->vp,			    /* read it first */
		blocknum,
		drive->blocksize,
		NOCRED,
		&bp);
	count = min(count, drive->blocksize - bp->b_resid); /* how much will we transfer now? */
	if (error == 0)
	    error = uiomove((char *) bp->b_data + blockoff, /* move the data to the block */
		count,
		&uio);
	if (error) {
	    brelse(bp);
	    drive->lasterror = error;
	    switch (error) {
	    case EIO:
		set_drive_state(drive->driveno, drive_down, setstate_force);
		break;

		/* XXX Add other possibilities here */
	    default:
	    }
	    return error;
	}
	if (count + blockoff == drive->blocksize)
	    /*
	     * The transfer goes to the end of the block.  There's
	     * no need to wait for any more data to arrive. 
	     */
	    bawrite(bp);				    /* start the write now */
	else
	    bdwrite(bp);				    /* do a delayed write */
    }
    while (error == 0 && uio.uio_resid > 0 && count != 0);
    if (error)
	drive->lasterror = error;
    return error;					    /* OK */
}

/* Wake up on completion */
void 
drive_io_done(struct buf *bp)
{
    wakeup((caddr_t) bp);				    /* Wachet auf! */
    bp->b_flags &= ~B_CALL;				    /* don't do this again */
}

/*
 * Check a drive for a vinum header.  If found, 
 * update the drive information.  We come here
 * with a partially populated drive structure
 * which includes the device name.
 *
 * Return information on what we found.
 *
 * This function is called from two places: check_drive,
 * which wants to find out whether the drive is a
 * Vinum drive, and config_drive, which asserts that
 * it is a vinum drive.  In the first case, we don't
 * print error messages (verbose==0), in the second
 * we do (verbose==1).
 */
enum drive_label_info 
read_drive_label(struct drive *drive, int verbose)
{
    int error;
    int result;						    /* result of our search */
    struct vinum_hdr *vhdr;				    /* and as header */

    error = init_drive(drive, 0);			    /* find the drive */
    if (error)						    /* find the drive */
	return DL_CANT_OPEN;				    /* not ours */

    vhdr = (struct vinum_hdr *) Malloc(VINUMHEADERLEN);	    /* allocate buffers */
    CHECKALLOC(vhdr, "Can't allocate memory");

    error = read_drive(drive, (void *) vhdr, VINUMHEADERLEN, VINUM_LABEL_OFFSET);
    if (vhdr->magic == VINUM_MAGIC) {			    /* ours! */
	if (drive->label.name[0]			    /* we have a name for this drive */
	&&(strcmp(drive->label.name, vhdr->label.name))) {  /* but it doesn't match the real name */
	    drive->lasterror = EINVAL;
	    result = DL_WRONG_DRIVE;			    /* it's the wrong drive */
	} else {
	    drive->state = drive_up;			    /* it's OK by us */
	    result = DL_OURS;
	}
	/*
	 * We copy the drive anyway so that we have
	 * the correct name in the drive info.  This
	 * may not be the name specified 
	 */
	drive->label = vhdr->label;			    /* put in the label information */
    } else if (vhdr->magic == VINUM_NOMAGIC)		    /* was ours, but we gave it away */
	result = DL_DELETED_LABEL;			    /* and return the info */
    else
	result = DL_NOT_OURS;				    /* we could have it, but we don't yet */
    Free(vhdr);						    /* that's all. */
    return result;
}

/*
 * Check a drive for a vinum header.  If found, 
 * read configuration information from the drive and
 * incorporate the data into the configuration.
 *
 * Return drive number.
 */
struct drive *
check_drive(char *devicename)
{
    int driveno;
    int i;
    struct drive *drive;

    driveno = find_drive_by_dev(devicename, 1);		    /* if entry doesn't exist, create it */
    drive = &vinum_conf.drive[driveno];			    /* and get a pointer */

    if (read_drive_label(drive, 0) == DL_OURS) {	    /* not ours */
	for (i = 0; i < vinum_conf.drives_allocated; i++) { /* see if the name already exists */
	    if ((i != driveno)				    /* not this drive */
&&(DRIVE[i].state != drive_unallocated)			    /* and it's allocated */
	    &&(strcmp(DRIVE[i].label.name,
			DRIVE[driveno].label.name) == 0)) { /* and it has the same name */
		struct drive *mydrive = &DRIVE[i];

		if (mydrive->devicename[0] == '/') {	    /* we know a device name for it */
		    /*
		     * set an error, but don't take the drive down:
		     * that would cause unneeded error messages.
		     */
		    drive->lasterror = EEXIST;
		    break;
		} else {				    /* it's just a place holder, */
		    int sdno;

		    for (sdno = 0; sdno < vinum_conf.subdisks_allocated; sdno++) { /* look at each subdisk */
			if ((SD[sdno].driveno == i)	    /* it's pointing to this one, */
			&&(SD[sdno].state != sd_unallocated)) {	/* and it's a real subdisk */
			    SD[sdno].driveno = drive->driveno; /* point to the one we found */
			    update_sd_state(sdno);	    /* and update its state */
			}
		    }
		    bzero(mydrive, sizeof(struct drive));   /* don't deallocate it, just remove it */
		}
	    }
	}
    } else {
	if (drive->lasterror == 0)
	    drive->lasterror = ENODEV;
	set_drive_state(drive->driveno, drive_down, setstate_force);
    }
    return drive;
}

static char *
sappend(char *txt, char *s)
{
    while ((*s++ = *txt++) != 0);
    return s - 1;
}

/* Kludge: kernel printf doesn't handle quads correctly XXX */
static char *lltoa(long long l, char *s);

static char *
lltoa(long long l, char *s)
{
    if (l < 0) {
	*s++ = '-';
	l = -l;
    }
    if (l > 9) {
	s = lltoa(l / 10, s);
	l %= 10;
    }
    *s++ = l + '0';
    return s;
}
/*
 * Format the configuration in text form into the buffer
 * at config.  Don't go beyond len bytes
 * XXX this stinks.  Fix soon. 
 */
void 
format_config(char *config, int len)
{
    int i;
    int j;
    char *s = config;

    bzero(config, len);

    /* First, the volume configuration */
    for (i = 0; i < vinum_conf.volumes_allocated; i++) {
	struct volume *vol;

	vol = &vinum_conf.volume[i];
	if ((vol->state > volume_uninit)
	    && (vol->name[0] != '\0')) {		    /* paranoia */
	    if (vol->preferred_plex >= 0)		    /* preferences, */
		sprintf(s,
		    "volume %s state %s readpol prefer %s",
		    vol->name,
		    volume_state(vol->state),
		    vinum_conf.plex[vol->preferred_plex].name);
	    else					    /* default round-robin */
		sprintf(s,
		    "volume %s state %s",
		    vol->name,
		    volume_state(vol->state));
	    while (*s)
		s++;					    /* find the end */
	    s = sappend("\n", s);
	    if (s > &config[len - 80]) {
		log(LOG_ERR, "vinum: configuration data overflow\n");
		return;
	    }
	}
    }

    /* Then the plex configuration */
    for (i = 0; i < vinum_conf.plexes_allocated; i++) {
	struct plex *plex;

	plex = &vinum_conf.plex[i];
	if ((plex->state != plex_referenced)
	    && (plex->name[0] != '\0')) {		    /* paranoia */
	    sprintf(s, "plex name %s state %s org %s ",
		plex->name,
		plex_state(plex->state),
		plex_org(plex->organization));
	    while (*s)
		s++;					    /* find the end */
	    if ((plex->organization == plex_striped)
		|| (plex->organization == plex_raid5)) {
		sprintf(s, "%db ", (int) plex->stripesize);
		while (*s)
		    s++;				    /* find the end */
	    }
	    if (plex->volno >= 0)			    /* we have a volume */
		sprintf(s, "vol %s ", vinum_conf.volume[plex->volno].name);
	    while (*s)
		s++;					    /* find the end */
	    for (j = 0; j < plex->subdisks; j++) {
		sprintf(s, " sd %s", vinum_conf.sd[plex->sdnos[j]].name);
	    }
	    s = sappend("\n", s);
	    if (s > &config[len - 80]) {
		log(LOG_ERR, "vinum: configuration data overflow\n");
		return;
	    }
	}
    }

    /* And finally the subdisk configuration */
    for (i = 0; i < vinum_conf.subdisks_allocated; i++) {
	struct sd *sd;

	sd = &SD[i];
	if ((sd->state != sd_referenced)
	    && (sd->name[0] != '\0')) {			    /* paranoia */
	    sprintf(s,
		"sd name %s drive %s plex %s state %s len ",
		sd->name,
		vinum_conf.drive[sd->driveno].label.name,
		vinum_conf.plex[sd->plexno].name,
		sd_state(sd->state));
	    while (*s)
		s++;					    /* find the end */
	    s = lltoa(sd->sectors, s);
	    s = sappend("b driveoffset ", s);
	    s = lltoa(sd->driveoffset, s);
	    s = sappend("b plexoffset ", s);
	    s = lltoa(sd->plexoffset, s);
	    s = sappend("b\n", s);
	    if (s > &config[len - 80]) {
		log(LOG_ERR, "vinum: configuration data overflow\n");
		return;
	    }
	}
    }
}

/*
 * issue a save config request to the d鎚on.  The actual work
 * is done in process context by daemon_save_config 
 */
void 
save_config(void)
{
    queue_daemon_request(daemonrq_saveconfig, (union daemoninfo) NULL);
}

/*
 * Write the configuration to all vinum slices.  This
 * is performed by the d鎚on only 
 */
void 
daemon_save_config(void)
{
    int error;
    int written_config;					    /* set when we first write the config to disk */
    int driveno;
    struct drive *drive;				    /* point to current drive info */
    struct vinum_hdr *vhdr;				    /* and as header */
    char *config;					    /* point to config data */
    int wlabel_on;					    /* to set writing label on/off */

    /* don't save the configuration while we're still working on it */
    if (vinum_conf.flags & VF_CONFIGURING)
	return;
    written_config = 0;					    /* no config written yet */
    /* Build a volume header */