cd.c

早期freebsd实现

/*
 * Copyright (c) 1988 University of Utah.
 * Copyright (c) 1990, 1993
 *	The Regents of the University of California.  All rights reserved.
 *
 * This code is derived from software contributed to Berkeley by
 * the Systems Programming Group of the University of Utah Computer
 * Science Department.
 *
 * 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 the University of
 *	California, Berkeley and its contributors.
 * 4. Neither the name of the University 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 REGENTS 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 REGENTS 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.
 *
 * from: Utah $Hdr: cd.c 1.6 90/11/28$
 *
 *	@(#)cd.c	8.2 (Berkeley) 11/16/93
 */

/*
 * "Concatenated" disk driver.
 */
#include "cd.h"
#if NCD > 0

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/proc.h>
#include <sys/errno.h>
#include <sys/dkstat.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/conf.h>
#include <sys/stat.h>
#ifdef COMPAT_NOLABEL
#include <sys/ioctl.h>
#include <sys/disklabel.h>
#include <sys/fcntl.h>
#endif

#include <dev/cdvar.h>

#ifdef DEBUG
int cddebug = 0x00;
#define CDB_FOLLOW	0x01
#define CDB_INIT	0x02
#define CDB_IO		0x04
#endif

struct	buf *cdbuffer();
char	*cddevtostr();
void	cdiodone();

#define	cdunit(x)	((minor(x) >> 3) & 0xf)	/* for consistency */

#define	getcbuf()	\
	((struct buf *)malloc(sizeof(struct buf), M_DEVBUF, M_WAITOK))
#define putcbuf(bp)	\
	free((caddr_t)(bp), M_DEVBUF)

struct cd_softc {
	int		 sc_flags;		/* flags */
	size_t		 sc_size;		/* size of cd */
	int		 sc_ileave;		/* interleave */
	int		 sc_ncdisks;		/* number of components */
	struct cdcinfo	 sc_cinfo[NCDISKS];	/* component info */
	struct cdiinfo	 *sc_itable;		/* interleave table */
	int		 sc_usecnt;		/* number of requests active */
	int		 sc_dk;			/* disk index */
};

/* sc_flags */
#define	CDF_ALIVE	0x01
#define CDF_INITED	0x02

struct cd_softc *cd_softc;
int numcd;

/*
 * Since this is called after auto-configuration of devices,
 * we can handle the initialization here.
 *
 * XXX this will not work if you want to use a cd as your primary
 * swap device since swapconf() has been called before now.
 */
void
cdattach(num)
	int num;
{
	char *mem;
	register u_long size;
	register struct cddevice *cd;
	extern int dkn;

	if (num <= 0)
		return;
	size = num * sizeof(struct cd_softc);
	mem = malloc(size, M_DEVBUF, M_NOWAIT);
	if (mem == NULL) {
		printf("WARNING: no memory for concatonated disks\n");
		return;
	}
	bzero(mem, size);
	cd_softc = (struct cd_softc *)mem;
	numcd = num;
	for (cd = cddevice; cd->cd_unit >= 0; cd++) {
		/*
		 * XXX
		 * Assign disk index first so that init routine
		 * can use it (saves having the driver drag around
		 * the cddevice pointer just to set up the dk_*
		 * info in the open routine).
		 */
		if (dkn < DK_NDRIVE)
			cd->cd_dk = dkn++;
		else
			cd->cd_dk = -1;
		if (cdinit(cd))
			printf("cd%d configured\n", cd->cd_unit);
		else if (cd->cd_dk >= 0) {
			cd->cd_dk = -1;
			dkn--;
		}
	}
}

cdinit(cd)
	struct cddevice *cd;
{
	register struct cd_softc *cs = &cd_softc[cd->cd_unit];
	register struct cdcinfo *ci;
	register size_t size;
	register int ix;
	size_t minsize;
	dev_t dev;
	struct bdevsw *bsw;
	int error;
	struct proc *p = curproc; /* XXX */

#ifdef DEBUG
	if (cddebug & (CDB_FOLLOW|CDB_INIT))
		printf("cdinit: unit %d\n", cd->cd_unit);
#endif
	cs->sc_dk = cd->cd_dk;
	cs->sc_size = 0;
	cs->sc_ileave = cd->cd_interleave;
	cs->sc_ncdisks = 0;
	/*
	 * Verify that each component piece exists and record
	 * relevant information about it.
	 */
	minsize = 0;
	for (ix = 0; ix < NCDISKS; ix++) {
		if ((dev = cd->cd_dev[ix]) == NODEV)
			break;
		ci = &cs->sc_cinfo[ix];
		ci->ci_dev = dev;
		bsw = &bdevsw[major(dev)];
		/*
		 * Open the partition
		 */
		if (bsw->d_open &&
		    (error = (*bsw->d_open)(dev, 0, S_IFBLK, p))) {
			printf("cd%d: component %s open failed, error = %d\n",
			       cd->cd_unit, cddevtostr(dev), error);
			return(0);
		}
		/*
		 * Calculate size (truncated to interleave boundary
		 * if necessary.
		 */
		if (bsw->d_psize) {
			size = (size_t) (*bsw->d_psize)(dev);
			if ((int)size < 0)
				size = 0;
		} else
			size = 0;
		if (cs->sc_ileave > 1)
			size -= size % cs->sc_ileave;
		if (size == 0) {
			printf("cd%d: not configured (component %s missing)\n",
			       cd->cd_unit, cddevtostr(dev));
			return(0);
		}
#ifdef COMPAT_NOLABEL
		/*
		 * XXX if this is a 'c' partition then we need to mark the
		 * label area writeable since there cannot be a label.
		 */
		if ((minor(dev) & 7) == 2 && bsw->d_open) {
			int i, flag;

			for (i = 0; i < nchrdev; i++)
				if (cdevsw[i].d_open == bsw->d_open)
					break;
			if (i != nchrdev && cdevsw[i].d_ioctl) {
				flag = 1;
				(void)(*cdevsw[i].d_ioctl)(dev, DIOCWLABEL,
					(caddr_t)&flag, FWRITE, p);
			}
		}
#endif
		if (minsize == 0 || size < minsize)
			minsize = size;
		ci->ci_size = size;
		cs->sc_size += size;
		cs->sc_ncdisks++;
	}
	/*
	 * If uniform interleave is desired set all sizes to that of
	 * the smallest component.
	 */
	if (cd->cd_flags & CDF_UNIFORM) {
		for (ci = cs->sc_cinfo;
		     ci < &cs->sc_cinfo[cs->sc_ncdisks]; ci++)
			ci->ci_size = minsize;
		cs->sc_size = cs->sc_ncdisks * minsize;
	}
	/*
	 * Construct the interleave table
	 */
	if (!cdinterleave(cs))
		return(0);
	if (cd->cd_dk >= 0)
		dk_wpms[cd->cd_dk] = 32 * (60 * DEV_BSIZE / 2);	/* XXX */
	printf("cd%d: %d components ", cd->cd_unit, cs->sc_ncdisks);
	for (ix = 0; ix < cs->sc_ncdisks; ix++)
		printf("%c%s%c",
		       ix == 0 ? '(' : ' ',
		       cddevtostr(cs->sc_cinfo[ix].ci_dev),
		       ix == cs->sc_ncdisks - 1 ? ')' : ',');
	printf(", %d blocks ", cs->sc_size);
	if (cs->sc_ileave)
		printf("interleaved at %d blocks\n", cs->sc_ileave);
	else
		printf("concatenated\n");
	cs->sc_flags = CDF_ALIVE | CDF_INITED;
	return(1);
}

/*
 * XXX not really cd specific.
 * Could be called something like bdevtostr in machine/conf.c.
 */
char *
cddevtostr(dev)
	dev_t dev;
{
	static char dbuf[5];

	switch (major(dev)) {
#ifdef hp300
	case 2:
		dbuf[0] = 'r'; dbuf[1] = 'd';
		break;
	case 4:
		dbuf[0] = 's'; dbuf[1] = 'd';
		break;
	case 5:
		dbuf[0] = 'c'; dbuf[1] = 'd';
		break;
	case 6:
		dbuf[0] = 'v'; dbuf[1] = 'n';
		break;
#endif
	default:
		dbuf[0] = dbuf[1] = '?';
		break;
	}
	dbuf[2] = (minor(dev) >> 3) + '0';
	dbuf[3] = (minor(dev) & 7) + 'a';
	dbuf[4] = '\0';
	return (dbuf);
}

cdinterleave(cs)
	register struct cd_softc *cs;
{
	register struct cdcinfo *ci, *smallci;
	register struct cdiinfo *ii;
	register daddr_t bn, lbn;
	register int ix;
	u_long size;

#ifdef DEBUG
	if (cddebug & CDB_INIT)
		printf("cdinterleave(%x): ileave %d\n", cs, cs->sc_ileave);
#endif
	/*
	 * Allocate an interleave table.
	 * Chances are this is too big, but we don't care.
	 */
	size = (cs->sc_ncdisks + 1) * sizeof(struct cdiinfo);
	cs->sc_itable = (struct cdiinfo *)malloc(size, M_DEVBUF, M_WAITOK);
	bzero((caddr_t)cs->sc_itable, size);
	/*
	 * Trivial case: no interleave (actually interleave of disk size).
	 * Each table entry represent a single component in its entirety.
	 */
	if (cs->sc_ileave == 0) {
		bn = 0;
		ii = cs->sc_itable;
		for (ix = 0; ix < cs->sc_ncdisks; ix++) {
			ii->ii_ndisk = 1;
			ii->ii_startblk = bn;
			ii->ii_startoff = 0;
			ii->ii_index[0] = ix;
			bn += cs->sc_cinfo[ix].ci_size;
			ii++;
		}
		ii->ii_ndisk = 0;
#ifdef DEBUG
		if (cddebug & CDB_INIT)
			printiinfo(cs->sc_itable);
#endif
		return(1);
	}
	/*
	 * The following isn't fast or pretty; it doesn't have to be.
	 */
	size = 0;
	bn = lbn = 0;
	for (ii = cs->sc_itable; ; ii++) {
		/*
		 * Locate the smallest of the remaining components
		 */
		smallci = NULL;
		for (ci = cs->sc_cinfo;
		     ci < &cs->sc_cinfo[cs->sc_ncdisks]; ci++)
			if (ci->ci_size > size &&
			    (smallci == NULL ||
			     ci->ci_size < smallci->ci_size))