ccd.c

基于组件方式开发操作系统的OSKIT源代码

/* $Id: ccd.c,v 1.37.2.2 1999/03/11 19:21:31 dg Exp $ */

/*	$NetBSD: ccd.c,v 1.22 1995/12/08 19:13:26 thorpej Exp $	*/

/*
 * Copyright (c) 1995 Jason R. Thorpe.
 * All rights reserved.
 *
 * 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 for the NetBSD Project
 *	by Jason R. Thorpe.
 * 4. The name of the author may not be used to endorse or promote products
 *    derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``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 AUTHOR 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.
 */

/*
 * 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.
 *
 * Dynamic configuration and disklabel support by:
 *	Jason R. Thorpe <[e-mail]>
 *	Numerical Aerodynamic Simulation Facility
 *	Mail Stop 258-6
 *	NASA Ames Research Center
 *	Moffett Field, CA 94035
 */

#include "ccd.h"
#if NCCD > 0

#include <sys/param.h>
#include <sys/systm.h>
#include <sys/kernel.h>
#include <sys/proc.h>
#include <sys/buf.h>
#include <sys/malloc.h>
#include <sys/namei.h>
#include <sys/conf.h>
#include <sys/stat.h>
#include <sys/sysctl.h>
#include <sys/disklabel.h>
#include <ufs/ffs/fs.h> 
#include <sys/device.h>
#include <sys/devicestat.h>
#undef KERNEL			/* XXX */
#include <sys/disk.h>
#define KERNEL
#include <sys/fcntl.h>
#include <sys/vnode.h>

#include <sys/ccdvar.h>

#if defined(CCDDEBUG) && !defined(DEBUG)
#define DEBUG
#endif

#ifdef DEBUG
#define CCDB_FOLLOW	0x01
#define CCDB_INIT	0x02
#define CCDB_IO		0x04
#define CCDB_LABEL	0x08
#define CCDB_VNODE	0x10
static int ccddebug = CCDB_FOLLOW | CCDB_INIT | CCDB_IO | CCDB_LABEL |
    CCDB_VNODE;
SYSCTL_INT(_debug, OID_AUTO, ccddebug, CTLFLAG_RW, &ccddebug, 0, "");
#undef DEBUG
#endif

#define	ccdunit(x)	dkunit(x)
#define ccdpart(x)	dkpart(x)

/*
   This is how mirroring works (only writes are special):

   When initiating a write, ccdbuffer() returns two "struct ccdbuf *"s
   linked together by the cb_mirror field.  "cb_pflags &
   CCDPF_MIRROR_DONE" is set to 0 on both of them.

   When a component returns to ccdiodone(), it checks if "cb_pflags &
   CCDPF_MIRROR_DONE" is set or not.  If not, it sets the partner's
   flag and returns.  If it is, it means its partner has already
   returned, so it will go to the regular cleanup.

 */

struct ccdbuf {
	struct buf	cb_buf;		/* new I/O buf */
	struct buf	*cb_obp;	/* ptr. to original I/O buf */
	int		cb_unit;	/* target unit */
	int		cb_comp;	/* target component */
	int		cb_pflags;	/* mirror/parity status flag */
	struct ccdbuf	*cb_mirror;	/* mirror counterpart */
};

/* bits in cb_pflags */
#define CCDPF_MIRROR_DONE 1	/* if set, mirror counterpart is done */

#define	getccdbuf()		\
	((struct ccdbuf *)malloc(sizeof(struct ccdbuf), M_DEVBUF, M_WAITOK))
#define putccdbuf(cbp)		\
	free((caddr_t)(cbp), M_DEVBUF)

#define CCDLABELDEV(dev)	\
	(makedev(major((dev)), dkmakeminor(ccdunit((dev)), 0, RAW_PART)))

static d_open_t ccdopen;
static d_read_t	ccdread;
static d_write_t ccdwrite;
static d_close_t ccdclose;
static d_strategy_t ccdstrategy;
static d_ioctl_t ccdioctl;
static d_dump_t ccddump;
static d_psize_t ccdsize;

#define CDEV_MAJOR 74
#define BDEV_MAJOR 21

static struct cdevsw ccd_cdevsw = {
	  ccdopen,	ccdclose,	ccdread,	ccdwrite,
	  ccdioctl,	nostop,		nullreset,	nodevtotty,
	  seltrue,	nommap,		ccdstrategy,	"ccd",
	  NULL, 	-1,		ccddump,	ccdsize,
	  D_DISK,	0,		-1 };

/* Called by main() during pseudo-device attachment */
static void	ccdattach __P((void *));
PSEUDO_SET(ccdattach, ccd);

/* called by biodone() at interrupt time */
static	void ccdiodone __P((struct ccdbuf *cbp));

static	void ccdstart __P((struct ccd_softc *, struct buf *));
static	void ccdinterleave __P((struct ccd_softc *, int));
static	void ccdintr __P((struct ccd_softc *, struct buf *));
static	int ccdinit __P((struct ccddevice *, char **, struct proc *));
static	int ccdlookup __P((char *, struct proc *p, struct vnode **));
static	void ccdbuffer __P((struct ccdbuf **ret, struct ccd_softc *,
		struct buf *, daddr_t, caddr_t, long));
static	void ccdgetdisklabel __P((dev_t));
static	void ccdmakedisklabel __P((struct ccd_softc *));
static	int ccdlock __P((struct ccd_softc *));
static	void ccdunlock __P((struct ccd_softc *));

#ifdef DEBUG
static	void printiinfo __P((struct ccdiinfo *));
#endif

/* Non-private for the benefit of libkvm. */
struct	ccd_softc *ccd_softc;
struct	ccddevice *ccddevs;
static	int numccd = 0;

static int ccd_devsw_installed = 0;

/*
 * Number of blocks to untouched in front of a component partition.
 * This is to avoid violating its disklabel area when it starts at the
 * beginning of the slice.
 */
#if !defined(CCD_OFFSET)
#define CCD_OFFSET 16
#endif

/*
 * Called by main() during pseudo-device attachment.  All we need
 * to do is allocate enough space for devices to be configured later, and
 * add devsw entries.
 */
static void
ccdattach(dummy)
	void *dummy;
{
	int i;
	int num = NCCD;

	if (num > 1)
		printf("ccd0-%d: Concatenated disk drivers\n", num-1);
	else
		printf("ccd0: Concatenated disk driver\n");

	ccd_softc = (struct ccd_softc *)malloc(num * sizeof(struct ccd_softc),
	    M_DEVBUF, M_NOWAIT);
	ccddevs = (struct ccddevice *)malloc(num * sizeof(struct ccddevice),
	    M_DEVBUF, M_NOWAIT);
	if ((ccd_softc == NULL) || (ccddevs == NULL)) {
		printf("WARNING: no memory for concatenated disks\n");
		if (ccd_softc != NULL)
			free(ccd_softc, M_DEVBUF);
		if (ccddevs != NULL)
			free(ccddevs, M_DEVBUF);
		return;
	}
	numccd = num;
	bzero(ccd_softc, num * sizeof(struct ccd_softc));
	bzero(ccddevs, num * sizeof(struct ccddevice));

	/* XXX: is this necessary? */
	for (i = 0; i < numccd; ++i)
		ccddevs[i].ccd_dk = -1;

	if( ! ccd_devsw_installed ) {
		cdevsw_add_generic(BDEV_MAJOR,CDEV_MAJOR, &ccd_cdevsw);
		ccd_devsw_installed = 1;
    	}
	else {
		printf("huh?\n");
	}
}

static int
ccdinit(ccd, cpaths, p)
	struct ccddevice *ccd;
	char **cpaths;
	struct proc *p;
{
	register struct ccd_softc *cs = &ccd_softc[ccd->ccd_unit];
	register struct ccdcinfo *ci = NULL;	/* XXX */
	register size_t size;
	register int ix;
	struct vnode *vp;
	struct vattr va;
	size_t minsize;
	int maxsecsize;
	struct partinfo dpart;
	struct ccdgeom *ccg = &cs->sc_geom;
	char tmppath[MAXPATHLEN];
	int error;

#ifdef DEBUG
	if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
		printf("ccdinit: unit %d\n", ccd->ccd_unit);
#endif

	cs->sc_size = 0;
	cs->sc_ileave = ccd->ccd_interleave;
	cs->sc_nccdisks = ccd->ccd_ndev;

	/* Allocate space for the component info. */
	cs->sc_cinfo = malloc(cs->sc_nccdisks * sizeof(struct ccdcinfo),
	    M_DEVBUF, M_WAITOK);

	/*
	 * Verify that each component piece exists and record
	 * relevant information about it.
	 */
	maxsecsize = 0;
	minsize = 0;
	for (ix = 0; ix < cs->sc_nccdisks; ix++) {
		vp = ccd->ccd_vpp[ix];
		ci = &cs->sc_cinfo[ix];
		ci->ci_vp = vp;

		/*
		 * Copy in the pathname of the component.
		 */
		bzero(tmppath, sizeof(tmppath));	/* sanity */
		if (error = copyinstr(cpaths[ix], tmppath,
		    MAXPATHLEN, &ci->ci_pathlen)) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				printf("ccd%d: can't copy path, error = %d\n",
				    ccd->ccd_unit, error);
#endif
			while (ci > cs->sc_cinfo) {
				ci--;
				free(ci->ci_path, M_DEVBUF);
			}
			free(cs->sc_cinfo, M_DEVBUF);
			return (error);
		}
		ci->ci_path = malloc(ci->ci_pathlen, M_DEVBUF, M_WAITOK);
		bcopy(tmppath, ci->ci_path, ci->ci_pathlen);

		/*
		 * XXX: Cache the component's dev_t.
		 */
		if (error = VOP_GETATTR(vp, &va, p->p_ucred, p)) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				printf("ccd%d: %s: getattr failed %s = %d\n",
				    ccd->ccd_unit, ci->ci_path,
				    "error", error);
#endif
			while (ci >= cs->sc_cinfo) {
				free(ci->ci_path, M_DEVBUF);
				ci--;
			}
			free(cs->sc_cinfo, M_DEVBUF);
			return (error);
		}
		ci->ci_dev = va.va_rdev;

		/*
		 * Get partition information for the component.
		 */
		if (error = VOP_IOCTL(vp, DIOCGPART, (caddr_t)&dpart,
		    FREAD, p->p_ucred, p)) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				 printf("ccd%d: %s: ioctl failed, error = %d\n",
				     ccd->ccd_unit, ci->ci_path, error);
#endif
			while (ci >= cs->sc_cinfo) {
				free(ci->ci_path, M_DEVBUF);
				ci--;
			}
			free(cs->sc_cinfo, M_DEVBUF);
			return (error);
		}
		if (dpart.part->p_fstype == FS_BSDFFS) {
			maxsecsize =
			    ((dpart.disklab->d_secsize > maxsecsize) ?
			    dpart.disklab->d_secsize : maxsecsize);
			size = dpart.part->p_size - CCD_OFFSET;
		} else {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				printf("ccd%d: %s: incorrect partition type\n",
				    ccd->ccd_unit, ci->ci_path);
#endif
			while (ci >= cs->sc_cinfo) {
				free(ci->ci_path, M_DEVBUF);
				ci--;
			}
			free(cs->sc_cinfo, M_DEVBUF);
			return (EFTYPE);
		}

		/*
		 * Calculate the size, truncating to an interleave
		 * boundary if necessary.
		 */

		if (cs->sc_ileave > 1)
			size -= size % cs->sc_ileave;

		if (size == 0) {
#ifdef DEBUG
			if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
				printf("ccd%d: %s: size == 0\n",
				    ccd->ccd_unit, ci->ci_path);
#endif
			while (ci >= cs->sc_cinfo) {
				free(ci->ci_path, M_DEVBUF);
				ci--;
			}
			free(cs->sc_cinfo, M_DEVBUF);
			return (ENODEV);
		}

		if (minsize == 0 || size < minsize)
			minsize = size;
		ci->ci_size = size;
		cs->sc_size += size;
	}

	/*
	 * Don't allow the interleave to be smaller than
	 * the biggest component sector.
	 */
	if ((cs->sc_ileave > 0) &&
	    (cs->sc_ileave < (maxsecsize / DEV_BSIZE))) {
#ifdef DEBUG
		if (ccddebug & (CCDB_FOLLOW|CCDB_INIT))
			printf("ccd%d: interleave must be at least %d\n",
			    ccd->ccd_unit, (maxsecsize / DEV_BSIZE));
#endif
		while (ci >= cs->sc_cinfo) {
			free(ci->ci_path, M_DEVBUF);
			ci--;
		}
		free(cs->sc_cinfo, M_DEVBUF);
		return (EINVAL);
	}

	/*
	 * If uniform interleave is desired set all sizes to that of
	 * the smallest component.
	 */
	if (ccd->ccd_flags & CCDF_UNIFORM) {
		for (ci = cs->sc_cinfo;
		     ci < &cs->sc_cinfo[cs->sc_nccdisks]; ci++)
			ci->ci_size = minsize;
		if (ccd->ccd_flags & CCDF_MIRROR) {
			/*
			 * Check to see if an even number of components
			 * have been specified.
			 */
			if (cs->sc_nccdisks % 2) {
				printf("ccd%d: mirroring requires an even number of disks\n", ccd->ccd_unit );
				while (ci > cs->sc_cinfo) {
					ci--;
					free(ci->ci_path, M_DEVBUF);
				}
				free(cs->sc_cinfo, M_DEVBUF);
				return (EINVAL);
			}
			cs->sc_size = (cs->sc_nccdisks/2) * minsize;
		}
		else if (ccd->ccd_flags & CCDF_PARITY)
			cs->sc_size = (cs->sc_nccdisks-1) * minsize;
		else
			cs->sc_size = cs->sc_nccdisks * minsize;
	}

	/*
	 * Construct the interleave table.
	 */
	ccdinterleave(cs, ccd->ccd_unit);

	/*
	 * Create pseudo-geometry based on 1MB cylinders.  It's
	 * pretty close.
	 */
	ccg->ccg_secsize = maxsecsize;
	ccg->ccg_ntracks = 1;
	ccg->ccg_nsectors = 1024 * (1024 / ccg->ccg_secsize);
	ccg->ccg_ncylinders = cs->sc_size / ccg->ccg_nsectors;

	/*
	 * Add an devstat entry for this device.
	 */
	devstat_add_entry(&cs->device_stats, "ccd", ccd->ccd_unit,
			  ccg->ccg_secsize, DEVSTAT_ALL_SUPPORTED,
			  DEVSTAT_TYPE_ASC0 |DEVSTAT_TYPE_IF_OTHER,
			  DEVSTAT_PRIORITY_CCD);

	cs->sc_flags |= CCDF_INITED;
	cs->sc_cflags = ccd->ccd_flags;	/* So we can find out later... */
	cs->sc_unit = ccd->ccd_unit;
	return (0);
}

static void
ccdinterleave(cs, unit)
	register struct ccd_softc *cs;
	int unit;
{
	register struct ccdcinfo *ci, *smallci;
	register struct ccdiinfo *ii;
	register daddr_t bn, lbn;
	register int ix;
	u_long size;

#ifdef DEBUG
	if (ccddebug & CCDB_INIT)
		printf("ccdinterleave(%x): ileave %d\n", cs, cs->sc_ileave);
#endif