File:  [DragonFly] / src / sys / dev / raid / vinum / vinumvar.h
Revision 1.5: download - view: text, annotated - select for diffs
Wed May 19 22:52:48 2004 UTC (10 years, 7 months ago) by dillon
Branches: MAIN
CVS tags: HEAD, DragonFly_Stable, DragonFly_Snap29Sep2004, DragonFly_Snap13Sep2004, DragonFly_RELEASE_1_4_Slip, DragonFly_RELEASE_1_4, DragonFly_RELEASE_1_2_Slip, DragonFly_RELEASE_1_2, DragonFly_1_0_REL, DragonFly_1_0_RC1, DragonFly_1_0A_REL
Device layer rollup commit.

* cdevsw_add() is now required.  cdevsw_add() and cdevsw_remove() may specify
  a mask/match indicating the range of supported minor numbers.  Multiple
  cdevsw_add()'s using the same major number, but distinctly different
  ranges, may be issued.  All devices that failed to call cdevsw_add() before
  now do.

* cdevsw_remove() now automatically marks all devices within its supported
  range as being destroyed.

* vnode->v_rdev is no longer resolved when the vnode is created.  Instead,
  only v_udev (a newly added field) is resolved.  v_rdev is resolved when
  the vnode is opened and cleared on the last close.

* A great deal of code was making rather dubious assumptions with regards
  to the validity of devices associated with vnodes, primarily due to
  the persistence of a device structure due to being indexed by (major, minor)
  instead of by (cdevsw, major, minor).  In particular, if you run a program
  which connects to a USB device and then you pull the USB device and plug
  it back in, the vnode subsystem will continue to believe that the device
  is open when, in fact, it isn't (because it was destroyed and recreated).

  In particular, note that all the VFS mount procedures now check devices
  via v_udev instead of v_rdev prior to calling VOP_OPEN(), since v_rdev
  is NULL prior to the first open.

* The disk layer's device interaction has been rewritten.  The disk layer
  (i.e. the slice and disklabel management layer) no longer overloads
  its data onto the device structure representing the underlying physical
  disk.  Instead, the disk layer uses the new cdevsw_add() functionality
  to register its own cdevsw using the underlying device's major number,
  and simply does NOT register the underlying device's cdevsw.  No
  confusion is created because the device hash is now based on
  (cdevsw,major,minor) rather then (major,minor).

  NOTE: This also means that underlying raw disk devices may use the entire
  device minor number instead of having to reserve the bits used by the disk
  layer, and also means that can we (theoretically) stack a fully
  disklabel-supported 'disk' on top of any block device.

* The new reference counting scheme prevents this by associating a device
  with a cdevsw and disconnecting the device from its cdevsw when the cdevsw
  is removed.  Additionally, all udev2dev() lookups run through the cdevsw
  mask/match and only successfully find devices still associated with an
  active cdevsw.

* Major work on MFS:  MFS no longer shortcuts vnode and device creation.  It
  now creates a real vnode and a real device and implements real open and
  close VOPs.  Additionally, due to the disk layer changes, MFS is no longer
  limited to 255 mounts.  The new limit is 16 million.  Since MFS creates a
  real device node, mount_mfs will now create a real /dev/mfs<PID> device
  that can be read from userland (e.g. so you can dump an MFS filesystem).

* BUF AND DEVICE STRATEGY changes.  The struct buf contains a b_dev field.
  In order to properly handle stacked devices we now require that the b_dev
  field be initialized before the device strategy routine is called.  This
  required some additional work in various VFS implementations.  To enforce
  this requirement, biodone() now sets b_dev to NODEV.  The new disk layer
  will adjust b_dev before forwarding a request to the actual physical
  device.

* A bug in the ISO CD boot sequence which resulted in a panic has been fixed.

Testing by: lots of people, but David Rhodus found the most aggregious bugs.

/*-
 * Copyright (c) 1997, 1998, 1999
 *	Nan Yang Computer Services Limited.  All rights reserved.
 *
 *  Parts copyright (c) 1997, 1998 Cybernet Corporation, NetMAX project.
 *
 *  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: vinumvar.h,v 1.24 2000/03/01 02:34:57 grog Exp grog $
 * $FreeBSD: src/sys/dev/vinum/vinumvar.h,v 1.32.2.4 2001/05/28 05:56:27 grog Exp $
 * $DragonFly: src/sys/dev/raid/vinum/vinumvar.h,v 1.5 2004/05/19 22:52:48 dillon Exp $
 */

#include <sys/time.h>
#include "vinumstate.h"

/*
 * Some configuration maxima.  They're an enum because
 * we can't define global constants.  Sorry about that.
 *
 * These aren't as bad as they look: most of them are soft limits.
 */

#define VINUMROOT
enum constants {
    VINUM_HEADER = 512,					    /* size of header on disk */
    MAXCONFIGLINE = 1024,				    /* maximum size of a single config line */
    MINVINUMSLICE = 1048576,				    /* minimum size of a slice */

    VINUM_CDEV_MAJOR = 91,				    /* major number for character device */

    ROUND_ROBIN_READPOL = -1,				    /* round robin read policy */

    /* type field in minor number */
    VINUM_VOLUME_TYPE = 0,
    VINUM_PLEX_TYPE = 1,
    VINUM_SD_TYPE = 2,
    VINUM_DRIVE_TYPE = 3,
    VINUM_SUPERDEV_TYPE = 4,				    /* super device. */
    VINUM_RAWPLEX_TYPE = 5,				    /* anonymous plex */
    VINUM_RAWSD_TYPE = 6,				    /* anonymous subdisk */

    /* Shifts for the individual fields in the device */
    VINUM_TYPE_SHIFT = 28,
    VINUM_VOL_SHIFT = 0,
    VINUM_PLEX_SHIFT = 16,
    VINUM_SD_SHIFT = 20,
    VINUM_VOL_WIDTH = 8,
    VINUM_PLEX_WIDTH = 3,
    VINUM_SD_WIDTH = 8,

/*
   * Shifts for the second half of raw plex and
   * subdisk numbers
 */
    VINUM_RAWPLEX_SHIFT = 8,				    /* shift the second half this much */
    VINUM_RAWPLEX_WIDTH = 12,				    /* width of second half */

    MAJORDEV_SHIFT = 8,

    MAXPLEX = 8,					    /* maximum number of plexes in a volume */
    MAXSD = 256,					    /* maximum number of subdisks in a plex */
    MAXDRIVENAME = 32,					    /* maximum length of a device name */
    MAXSDNAME = 64,					    /* maximum length of a subdisk name */
    MAXPLEXNAME = 64,					    /* maximum length of a plex name */
    MAXVOLNAME = 64,					    /* maximum length of a volume name */
    MAXNAME = 64,					    /* maximum length of any name */


    /*
     * Define a minor device number.
     * This is not used directly; instead, it's
     * called by the other macros.
     */
#define VINUMMINOR(v,p,s,t)  ( (v << VINUM_VOL_SHIFT)		\
			      | (p << VINUM_PLEX_SHIFT)		\
			      | (s << VINUM_SD_SHIFT)		\
			      | (t << VINUM_TYPE_SHIFT) )

/* Create device minor numbers */

#ifdef _KERNEL

#define VINUMDEV(v,p,s,t)  	\
		make_adhoc_dev (&vinum_cdevsw, VINUMMINOR (v, p, s, t))

#define VINUM_PLEX(p)		\
		make_adhoc_dev (&vinum_cdevsw,			\
		 (VINUM_RAWPLEX_TYPE << VINUM_TYPE_SHIFT) 	\
		 | (p & 0xff)					\
		 | ((p & ~0xff) << 8) )

#define VINUM_SD(s)		\
		make_adhoc_dev (&vinum_cdevsw,			\
		 (VINUM_RAWSD_TYPE << VINUM_TYPE_SHIFT) 	\
		 | (s & 0xff)					\
		 | ((s & ~0xff) << 8) )

#else

#define VINUMDEV(v,p,s,t)  	\
		makedev(VINUM_CDEV_MAJOR, VINUMMINOR (v, p, s, t))

#define VINUM_PLEX(p)		\
		makedev(VINUM_CDEV_MAJOR,			\
		 (VINUM_RAWPLEX_TYPE << VINUM_TYPE_SHIFT) 	\
		 | (p & 0xff)					\
		 | ((p & ~0xff) << 8) )

#define VINUM_SD(s)		\
		makedev(VINUM_CDEV_MAJOR,			\
		 (VINUM_RAWSD_TYPE << VINUM_TYPE_SHIFT) 	\
		 | (s & 0xff)					\
		 | ((s & ~0xff) << 8) )

#endif

    /* Create a bit mask for x bits */
#define MASK(x)	 ((1 << (x)) - 1)

    /* Create a raw block device minor number */
#define VINUMRMINOR(d,t) ( ((d & MASK (VINUM_VOL_WIDTH)) << VINUM_VOL_SHIFT)	\
			  | ((d & ~MASK (VINUM_VOL_WIDTH))			\
			     << (VINUM_PLEX_SHIFT + VINUM_VOL_WIDTH))		\
			  | (t << VINUM_TYPE_SHIFT) )

    /* extract device type */
#define DEVTYPE(x) ((minor (x) >> VINUM_TYPE_SHIFT) & 7)

    /*
     * This mess is used to catch people who compile
     * a debug vinum(8) and non-debug kernel module,
     * or the other way round.
     */

#ifdef VINUMDEBUG
#define	VINUM_SUPERDEV VINUMMINOR (1, 0, 0, VINUM_SUPERDEV_TYPE) /* superdevice number */
#define	VINUM_WRONGSUPERDEV VINUMMINOR (2, 0, 0, VINUM_SUPERDEV_TYPE) /* non-debug superdevice number */
#else
#define	VINUM_SUPERDEV VINUMMINOR (2, 0, 0, VINUM_SUPERDEV_TYPE) /* superdevice number */
#define	VINUM_WRONGSUPERDEV VINUMMINOR (1, 0, 0, VINUM_SUPERDEV_TYPE) /* debug superdevice number */
#endif

#define	VINUM_DAEMON_DEV VINUMMINOR (0, 0, 0, VINUM_SUPERDEV_TYPE) /* daemon superdevice number */

/*
 * the number of object entries to cater for initially, and also the
 * value by which they are incremented.  It doesn't take long
 * to extend them, so theoretically we could start with 1 of each, but
 * it's untidy to allocate such small areas.  These values are
 * probably too small.
 */

    INITIAL_DRIVES = 4,
    INITIAL_VOLUMES = 4,
    INITIAL_PLEXES = 8,
    INITIAL_SUBDISKS = 16,
    INITIAL_SUBDISKS_IN_PLEX = 4,			    /* number of subdisks to allocate to a plex */
    INITIAL_SUBDISKS_IN_DRIVE = 4,			    /* number of subdisks to allocate to a drive */
    INITIAL_DRIVE_FREELIST = 16,			    /* number of entries in drive freelist */
    PLEX_REGION_TABLE_SIZE = 8,				    /* number of entries in plex region tables */
    PLEX_LOCKS = 256,					    /* number of locks to allocate to a plex */
    MAX_REVIVE_BLOCKSIZE = MAXPHYS,			    /* maximum revive block size */
    DEFAULT_REVIVE_BLOCKSIZE = 65536,			    /* default revive block size */
    VINUMHOSTNAMELEN = 32,				    /* host name field in label */
};

/* device numbers */

/*
 *  31 30   28  27                  20  19 18    16  15                 8    7                   0
 * |-----------------------------------------------------------------------------------------------|
 * |X |  Type  |    Subdisk number     | X| Plex   |      Major number     |  volume number        |
 * |-----------------------------------------------------------------------------------------------|
 *
 *    0x2                 03                 1           19                      06
 *
 * The fields in the minor number are interpreted as follows:
 *
 * Volume:              Only type and volume number are relevant
 * Plex in volume:      type, plex number in volume and volume number are relevant
 * raw plex:            type, plex number is made of bits 27-16 and 7-0
 * raw subdisk:         type, subdisk number is made of bits 27-16 and 7-0
 */

/* This doesn't get used.  Consider removing it. */
struct devcode {
/*
 * CARE.  These fields assume a big-endian word.  On a
 * little-endian system, they're the wrong way around
 */
    unsigned volume:8;					    /* up to 256 volumes */
    unsigned major:8;					    /* this is where the major number fits */
    unsigned plex:3;					    /* up to 8 plexes per volume */
    unsigned unused:1;					    /* up for grabs */
    unsigned sd:8;					    /* up to 256 subdisks per plex */
    unsigned type:3;					    /* type of object */
    /*
     * type field
     VINUM_VOLUME = 0,
     VINUM_PLEX = 1,
     VINUM_SUBDISK = 2,
     VINUM_DRIVE = 3,
     VINUM_SUPERDEV = 4,
     VINUM_RAWPLEX = 5,
     VINUM_RAWSD = 6 */
    unsigned signbit:1;					    /* to make 32 bits */
};

#define VINUM_DIR   "/dev/vinum"

/*
 * These definitions help catch
 * userland/kernel mismatches.
 */
#if VINUMDEBUG
#define VINUM_WRONGSUPERDEV_NAME VINUM_DIR"/control"	    /* normal super device */
#define VINUM_SUPERDEV_NAME VINUM_DIR"/Control"		    /* debug super device */
#else
#define VINUM_WRONGSUPERDEV_NAME VINUM_DIR"/Control"	    /* debug super device */
#define VINUM_SUPERDEV_NAME VINUM_DIR"/control"		    /* normal super device */
#endif
#define VINUM_DAEMON_DEV_NAME VINUM_DIR"/controld"	    /* super device for daemon only */

/*
 * Flags for all objects.  Most of them only apply to
 * specific objects, but we have space for all in any
 * 32 bit flags word.
 */
enum objflags {
    VF_LOCKED = 1,					    /* somebody has locked access to this object */
    VF_LOCKING = 2,					    /* we want access to this object */
    VF_OPEN = 4,					    /* object has openers */
    VF_WRITETHROUGH = 8,				    /* volume: write through */
    VF_INITED = 0x10,					    /* unit has been initialized */
    VF_WLABEL = 0x20,					    /* label area is writable */
    VF_LABELLING = 0x40,				    /* unit is currently being labelled */
    VF_WANTED = 0x80,					    /* someone is waiting to obtain a lock */
    VF_RAW = 0x100,					    /* raw volume (no file system) */
    VF_LOADED = 0x200,					    /* module is loaded */
    VF_CONFIGURING = 0x400,				    /* somebody is changing the config */
    VF_WILL_CONFIGURE = 0x800,				    /* somebody wants to change the config */
    VF_CONFIG_INCOMPLETE = 0x1000,			    /* haven't finished changing the config */
    VF_CONFIG_SETUPSTATE = 0x2000,			    /* set a volume up if all plexes are empty */
    VF_READING_CONFIG = 0x4000,				    /* we're reading config database from disk */
    VF_FORCECONFIG = 0x8000,				    /* configure drives even with different names */
    VF_NEWBORN = 0x10000,				    /* for objects: we've just created it */
    VF_CONFIGURED = 0x20000,				    /* for drives: we read the config */
    VF_STOPPING = 0x40000,				    /* for vinum_conf: stop on last close */
    VF_DAEMONOPEN = 0x80000,				    /* the daemon has us open (only superdev) */
    VF_CREATED = 0x100000,				    /* for volumes: freshly created, more then new */
    VF_HOTSPARE = 0x200000,				    /* for drives: use as hot spare */
    VF_RETRYERRORS = 0x400000,				    /* don't down subdisks on I/O errors */
};

/* Global configuration information for the vinum subsystem */
struct _vinum_conf {
    /* Pointers to vinum structures */
    struct drive *drive;
    struct sd *sd;
    struct plex *plex;
    struct volume *volume;

    /* the number allocated */
    int drives_allocated;
    int subdisks_allocated;
    int plexes_allocated;
    int volumes_allocated;

    /* and the number currently in use */
    int drives_used;
    int subdisks_used;
    int plexes_used;
    int volumes_used;

    int flags;

#define VINUM_MAXACTIVE  30000				    /* maximum number of active requests */
    int active;						    /* current number of requests outstanding */
    int maxactive;					    /* maximum number of requests ever outstanding */
#if VINUMDEBUG
    struct request *lastrq;
    struct buf *lastbuf;
#endif
};

/* Use these defines to simplify code */
#define DRIVE vinum_conf.drive
#define SD vinum_conf.sd
#define PLEX vinum_conf.plex
#define VOL vinum_conf.volume
#define VFLAGS vinum_conf.flags

/*
 * Slice header
 *
 * Vinum drives start with this structure:
 *
 *\                                            Sector
 * |--------------------------------------|
 * |   PDP-11 memorial boot block         |      0
 * |--------------------------------------|
 * |   Disk label, maybe                  |      1
 * |--------------------------------------|
 * |   Slice definition  (vinum_hdr)      |      8
 * |--------------------------------------|
 * |                                      |
 * |   Configuration info, first copy     |      9
 * |                                      |
 * |--------------------------------------|
 * |                                      |
 * |   Configuration info, second copy    |      9 + size of config
 * |                                      |
 * |--------------------------------------|
 */

/* Sizes and offsets of our information */
enum {
    VINUM_LABEL_OFFSET = 4096,				    /* offset of vinum label */
    VINUMHEADERLEN = 512,				    /* size of vinum label */
    VINUM_CONFIG_OFFSET = 4608,				    /* offset of first config copy */
    MAXCONFIG = 65536,					    /* and size of config copy */
    DATASTART = (MAXCONFIG * 2 + VINUM_CONFIG_OFFSET) / DEV_BSIZE /* this is where the data starts */
};

/*
 * hostname is 256 bytes long, but we don't need to shlep
 * multiple copies in vinum.  We use the host name just
 * to identify this system, and 32 bytes should be ample
 * for that purpose
 */

struct vinum_label {
    char sysname[VINUMHOSTNAMELEN];			    /* system name at time of creation */
    char name[MAXDRIVENAME];				    /* our name of the drive */
    struct timeval date_of_birth;			    /* the time it was created */
    struct timeval last_update;				    /* and the time of last update */
    /*
     * total size in bytes of the drive.  This value
     * includes the headers.
     */
    off_t drive_size;
};

struct vinum_hdr {
    uint64_t magic;					    /* we're long on magic numbers */
#define VINUM_MAGIC    22322600044678729LL		    /* should be this */
#define VINUM_NOMAGIC  22322600044678990LL		    /* becomes this after obliteration */
    /*
     * Size in bytes of each copy of the
     * configuration info.  This must be a multiple
     * of the sector size.
     */
    int config_length;
    struct vinum_label label;				    /* unique label */
};

/* Information returned from read_drive_label */
enum drive_label_info {
    DL_CANT_OPEN,					    /* invalid partition */
    DL_NOT_OURS,					    /* valid partition, but no vinum label */
    DL_DELETED_LABEL,					    /* valid partition, deleted label found */
    DL_WRONG_DRIVE,					    /* drive name doesn't match */
    DL_OURS						    /* valid partition and label found */
};

/*** Drive definitions ***/
/*
 * A drive corresponds to a disk slice.  We use a different term to show
 * the difference in usage: it doesn't have to be a slice, and could
 * theoretically be a complete, unpartitioned disk
 */

struct drive {
    char devicename[MAXDRIVENAME];			    /* name of the slice it's on */
    enum drivestate state;				    /* current state */
    int flags;						    /* flags */
    int subdisks_allocated;				    /* number of entries in sd */
    int subdisks_used;					    /* and the number used */
    int blocksize;					    /* size of fs blocks */
    int pid;						    /* of locker */
    u_int64_t sectors_available;			    /* number of sectors still available */
    int secsperblock;
    int lasterror;					    /* last error on drive */
    int driveno;					    /* index of drive in vinum_conf */
    int opencount;					    /* number of up subdisks */
    u_int64_t reads;					    /* number of reads on this drive */
    u_int64_t writes;					    /* number of writes on this drive */
    u_int64_t bytes_read;				    /* number of bytes read */
    u_int64_t bytes_written;				    /* number of bytes written */
    struct vinum_label label;				    /* and the label information */
#define DRIVE_MAXACTIVE  30000				    /* maximum number of active requests */
    int active;						    /* current number of requests outstanding */
    int maxactive;					    /* maximum number of requests ever outstanding */
    int freelist_size;					    /* number of entries alloced in free list */
    int freelist_entries;				    /* number of entries used in free list */
    struct drive_freelist {				    /* sorted list of free space on drive */
	u_int64_t offset;				    /* offset of entry */
	u_int64_t sectors;				    /* and length in sectors */
    } *freelist;
    struct partinfo partinfo;				    /* partition information */
/* XXX kludge until we get this struct cleaned up */
#if _KERNEL
    dev_t dev;						    /* device information */
#else
    char dev [sizeof (int *)];
#endif
#ifdef VINUMDEBUG
    char lockfilename[16];				    /* name of file from which we were locked */
    int lockline;					    /* and the line number */
#endif
};

/*** Subdisk definitions ***/

struct sd {
    char name[MAXSDNAME];				    /* name of subdisk */
    enum sdstate state;					    /* state */
    int flags;
    int lasterror;					    /* last error occurred */
    /* offsets in blocks */
    int64_t driveoffset;				    /* offset on drive */
    /*
     * plexoffset is the offset from the beginning
     * of the plex to the very first part of the
     * subdisk, in sectors.  For striped, RAID-4 and
     * RAID-5 plexes, only the first stripe is
     * located at this offset
     */
    int64_t plexoffset;					    /* offset in plex */
    u_int64_t sectors;					    /* and length in sectors */
    int plexno;						    /* index of plex, if it belongs */
    int driveno;					    /* index of the drive on which it is located */
    int sdno;						    /* our index in vinum_conf */
    int plexsdno;					    /* and our number in our plex */
    /* (undefined if no plex) */
    u_int64_t reads;					    /* number of reads on this subdisk */
    u_int64_t writes;					    /* number of writes on this subdisk */
    u_int64_t bytes_read;				    /* number of bytes read */
    u_int64_t bytes_written;				    /* number of bytes written */
    /* revive parameters */
    u_int64_t revived;					    /* block number of current revive request */
    int revive_blocksize;				    /* revive block size (bytes) */
    int revive_interval;				    /* and time to wait between transfers */
    pid_t reviver;					    /* PID of reviving process */
    /* init parameters */
    u_int64_t initialized;				    /* block number of current init request */
    int init_blocksize;					    /* init block size (bytes) */
    int init_interval;					    /* and time to wait between transfers */
    struct request *waitlist;				    /* list of requests waiting on revive op */
};

/*** Plex definitions ***/

/* kinds of plex organization */
enum plexorg {
    plex_disorg,					    /* disorganized */
    plex_concat,					    /* concatenated plex */
    plex_striped,					    /* striped plex */
    plex_raid4,						    /* RAID4 plex */
    plex_raid5						    /* RAID5 plex */
};

/* Recognize plex organizations */
#define isstriped(p) (p->organization >= plex_striped)	    /* RAID 1, 4 or 5 */
#define isparity(p) (p->organization >= plex_raid4)	    /* RAID 4 or 5 */

struct plex {
    char name[MAXPLEXNAME];				    /* name of plex */
    enum plexorg organization;				    /* Plex organization */
    enum plexstate state;				    /* and current state */
    u_int64_t length;					    /* total length of plex (sectors) */
    int flags;
    int stripesize;					    /* size of stripe or raid band, in sectors */
    int subdisks;					    /* number of associated subdisks */
    int subdisks_allocated;				    /* number of subdisks allocated space for */
    int *sdnos;						    /* list of component subdisks */
    int plexno;						    /* index of plex in vinum_conf */
    int volno;						    /* index of volume */
    int volplexno;					    /* number of plex in volume */
    /* Statistics */
    u_int64_t reads;					    /* number of reads on this plex */
    u_int64_t writes;					    /* number of writes on this plex */
    u_int64_t bytes_read;				    /* number of bytes read */
    u_int64_t bytes_written;				    /* number of bytes written */
    u_int64_t recovered_reads;				    /* number of recovered read operations */
    u_int64_t degraded_writes;				    /* number of degraded writes */
    u_int64_t parityless_writes;			    /* number of parityless writes */
    u_int64_t multiblock;				    /* requests that needed more than one block */
    u_int64_t multistripe;				    /* requests that needed more than one stripe */
    int sddowncount;					    /* number of subdisks down */
    /* Lock information */
    int usedlocks;					    /* number currently in use */
    int lockwaits;					    /* and number of waits for locks */
    off_t checkblock;					    /* block number for parity op */
    struct rangelock *lock;				    /* ranges of locked addresses */
};

/*** Volume definitions ***/

/* Address range definitions, for locking volumes */
struct rangelock {
    daddr_t stripe;					    /* address + 1 of the range being locked  */
    struct buf *bp;					    /* user's buffer pointer */
};

struct volume {
    char name[MAXVOLNAME];				    /* name of volume */
    enum volumestate state;				    /* current state */
    int plexes;						    /* number of plexes */
    int preferred_plex;					    /* plex to read from, -1 for round-robin */
    /*
     * index of plex used for last read, for
     * round-robin.
     */
    int last_plex_read;
    int volno;						    /* volume number */
    int flags;						    /* status and configuration flags */
    int openflags;					    /* flags supplied to last open(2) */
    u_int64_t size;					    /* size of volume */
    int blocksize;					    /* logical block size */
    int active;						    /* number of outstanding requests active */
    int subops;						    /* and the number of suboperations */
    /* Statistics */
    u_int64_t bytes_read;				    /* number of bytes read */
    u_int64_t bytes_written;				    /* number of bytes written */
    u_int64_t reads;					    /* number of reads on this volume */
    u_int64_t writes;					    /* number of writes on this volume */
    u_int64_t recovered_reads;				    /* reads recovered from another plex */
    /*
     * Unlike subdisks in the plex, space for the
     * plex pointers is static.
     */
    int plex[MAXPLEX];					    /* index of plexes */
    struct disklabel label;				    /* for DIOCGPART */
};

/*
 * Table expansion.  Expand table, which contains oldcount
 * entries of type element, by increment entries, and change
 * oldcount accordingly
 */
#define EXPAND(table, element, oldcount, increment)         \
{							    \
  expand_table ((void **) &table,			    \
		oldcount * sizeof (element),		    \
		(oldcount + increment) * sizeof (element) ); \
  oldcount += increment;				    \
  }

/* Information on vinum's memory usage */
struct meminfo {
    int mallocs;					    /* number of malloced blocks */
    int total_malloced;					    /* total amount malloced */
    int highwater;					    /* maximum number of mallocs */
    struct mc *malloced;				    /* pointer to kernel table */
};

#define MCFILENAMELEN	16
struct mc {
    struct timeval time;
    int seq;
    int size;
    short line;
    caddr_t address;
    char file[MCFILENAMELEN];
};

/*
 * These enums are used by the state transition
 * routines.  They're in bit map format:
 *
 * Bit 0: Other plexes in the volume are down
 * Bit 1: Other plexes in the volume are up
 * Bit 2: The current plex is up
 * Maybe they should be local to
 * state.c
 */
enum volplexstate {
    volplex_onlyusdown = 0,				    /* 0: we're the only plex, and we're down */
    volplex_alldown,					    /* 1: another plex is down, and so are we */
    volplex_otherup,					    /* 2: another plex is up */
    volplex_otherupdown,				    /* 3: other plexes are up and down */
    volplex_onlyus,					    /* 4: we're up and alone */
    volplex_onlyusup,					    /* 5: only we are up, others are down */
    volplex_allup,					    /* 6: all plexes are up */
    volplex_someup					    /* 7: some plexes are up, including us */
};

/* state map for plex */
enum sdstates {
    sd_emptystate = 1,
    sd_downstate = 2,					    /* SD is down */
    sd_crashedstate = 4,				    /* SD is crashed */
    sd_obsoletestate = 8,				    /* SD is obsolete */
    sd_stalestate = 16,					    /* SD is stale */
    sd_rebornstate = 32,				    /* SD is reborn */
    sd_upstate = 64,					    /* SD is up */
    sd_initstate = 128,					    /* SD is initializing */
    sd_initializedstate = 256,				    /* SD is initialized */
    sd_otherstate = 512,				    /* SD is in some other state */
};

/*
 * This is really just a parameter to pass to
 * set_<foo>_state, but since it needs to be known
 * in the external definitions, we need to define
 * it here
 */
enum setstateflags {
    setstate_none = 0,					    /* no flags */
    setstate_force = 1,					    /* force the state change */
    setstate_configuring = 2,				    /* we're currently configuring, don't save */
};

/* Operations for parityops to perform. */
enum parityop {
    checkparity,
    rebuildparity,
    rebuildandcheckparity,				    /* rebuildparity with the -v option */
};

#ifdef VINUMDEBUG
/* Debugging stuff */
enum debugflags {
    DEBUG_ADDRESSES = 1,				    /* show buffer information during requests */
    DEBUG_NUMOUTPUT = 2,				    /* show the value of vp->v_numoutput */
    DEBUG_RESID = 4,					    /* go into debugger in complete_rqe */
    DEBUG_LASTREQS = 8,					    /* keep a circular buffer of last requests */
    DEBUG_REVIVECONFLICT = 16,				    /* print info about revive conflicts */
    DEBUG_EOFINFO = 32,					    /* print info about EOF detection */
    DEBUG_MEMFREE = 64,					    /* keep info about Frees */
    DEBUG_BIGDRIVE = 128,				    /* pretend our drives are 100 times the size */
    DEBUG_REMOTEGDB = 256,				    /* go into remote gdb */
    DEBUG_WARNINGS = 512,				    /* log various relatively harmless warnings  */
};

#ifdef _KERNEL
#ifdef __i386__
#define longjmp LongJmp					    /* test our longjmps */
#endif
#endif
#endif
/* Local Variables: */
/* fill-column: 50 */
/* End: */