dev/raidframe/rf_psstatus.h

/*	$NetBSD: rf_psstatus.h,v 1.1 1998/11/13 04:20:32 oster Exp $	*/
/*
 * Copyright (c) 1995 Carnegie-Mellon University.
 * All rights reserved.
 *
 * Author: Mark Holland
 *
 * Permission to use, copy, modify and distribute this software and
 * its documentation is hereby granted, provided that both the copyright
 * notice and this permission notice appear in all copies of the
 * software, derivative works or modified versions, and any portions
 * thereof, and that both notices appear in supporting documentation.
 *
 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
 * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
 *
 * Carnegie Mellon requests users of this software to return to
 *
 *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
 *  School of Computer Science
 *  Carnegie Mellon University
 *  Pittsburgh PA 15213-3890
 *
 * any improvements or extensions that they make and grant Carnegie the
 * rights to redistribute these changes.
 */

/*****************************************************************************
 *
 * psstatus.h
 *
 * The reconstruction code maintains a bunch of status related to the parity
 * stripes that are currently under reconstruction.  This header file defines
 * the status structures.
 *
 *****************************************************************************/

/* :
 * Log: rf_psstatus.h,v
 * Revision 1.16  1996/06/10 11:55:47  jimz
 * Straightened out some per-array/not-per-array distinctions, fixed
 * a couple bugs related to confusion. Added shutdown lists. Removed
 * layout shutdown function (now subsumed by shutdown lists).
 *
 * Revision 1.15  1996/06/07  22:26:27  jimz
 * type-ify which_ru (RF_ReconUnitNum_t)
 *
 * Revision 1.14  1996/06/07  21:33:04  jimz
 * begin using consistent types for sector numbers,
 * stripe numbers, row+col numbers, recon unit numbers
 *
 * Revision 1.13  1996/06/05  18:06:02  jimz
 * Major code cleanup. The Great Renaming is now done.
 * Better modularity. Better typing. Fixed a bunch of
 * synchronization bugs. Made a lot of global stuff
 * per-desc or per-array. Removed dead code.
 *
 * Revision 1.12  1996/06/02  17:31:48  jimz
 * Moved a lot of global stuff into array structure, where it belongs.
 * Fixed up paritylogging, pss modules in this manner. Some general
 * code cleanup. Removed lots of dead code, some dead files.
 *
 * Revision 1.11  1996/05/24  22:17:04  jimz
 * continue code + namespace cleanup
 * typed a bunch of flags
 *
 * Revision 1.10  1996/05/23  21:46:35  jimz
 * checkpoint in code cleanup (release prep)
 * lots of types, function names have been fixed
 *
 * Revision 1.9  1996/05/23  00:33:23  jimz
 * code cleanup: move all debug decls to rf_options.c, all extern
 * debug decls to rf_options.h, all debug vars preceded by rf_
 *
 * Revision 1.8  1996/05/18  19:51:34  jimz
 * major code cleanup- fix syntax, make some types consistent,
 * add prototypes, clean out dead code, et cetera
 *
 * Revision 1.7  1995/11/30  16:17:28  wvcii
 * added copyright info
 *
 */

#ifndef _RF__RF_PSSTATUS_H_
#define _RF__RF_PSSTATUS_H_

#include "rf_types.h"
#include "rf_threadstuff.h"
#include "rf_callback.h"

#define RF_PS_MAX_BUFS 10 /* max number of bufs we'll accumulate before we do an XOR */

#define RF_PSS_DEFAULT_TABLESIZE 200

/*
 * Macros to acquire/release the mutex lock on a parity stripe status
 * descriptor. Note that we use just one lock for the whole hash chain.
 */
#define RF_HASH_PSID(_raid_,_psid_) ( (_psid_) % ((_raid_)->pssTableSize) )   /* simple hash function */
#define RF_LOCK_PSS_MUTEX(_raidPtr, _row, _psid) \
  RF_LOCK_MUTEX((_raidPtr)->reconControl[_row]->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex)
#define RF_UNLOCK_PSS_MUTEX(_raidPtr, _row, _psid) \
  RF_UNLOCK_MUTEX((_raidPtr)->reconControl[_row]->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex)

struct RF_ReconParityStripeStatus_s {
  RF_StripeNum_t    parityStripeID; /* the parity stripe ID */
  RF_ReconUnitNum_t which_ru;       /* which reconstruction unit with the indicated parity stripe */
  RF_PSSFlags_t     flags;          /* flags indicating various conditions */
  void           *rbuf;         /* this is the accumulating xor sum */
  void           *writeRbuf;    /* DEBUG ONLY:  a pointer to the rbuf after it has filled & been sent to disk */
  void     *rbufsForXor[RF_PS_MAX_BUFS]; /* these are buffers still to be xored into the accumulating sum */
  int             xorBufCount;  /* num buffers waiting to be xored */
  int             blockCount;   /* count of # proc that have blocked recon on this parity stripe */
  char           *issued;       /* issued[i]==1 <=> column i has already issued a read request for the indicated RU */
  RF_CallbackDesc_t *procWaitList; /* list of user procs waiting for recon to be done */
  RF_CallbackDesc_t *blockWaitList;/* list of disks blocked waiting for user write to complete */
  RF_CallbackDesc_t *bufWaitList;  /* list of disks blocked waiting to acquire a buffer for this RU */
  RF_ReconParityStripeStatus_t *next;
};

struct RF_PSStatusHeader_s {
  RF_DECLARE_MUTEX(mutex)               /* mutex for this hash chain */
  RF_ReconParityStripeStatus_t *chain;  /* the hash chain */
};

/* masks for the "flags" field above */
#define RF_PSS_NONE            0x00000000      /* no flags */
#define RF_PSS_UNDER_RECON     0x00000001      /* this parity stripe is currently under reconstruction */
#define RF_PSS_FORCED_ON_WRITE 0x00000002      /* indicates a recon was forced due to a user-write operation */
#define RF_PSS_FORCED_ON_READ  0x00000004      /* ditto for read, but not currently implemented */
#define RF_PSS_RECON_BLOCKED   0x00000008      /* reconstruction is currently blocked due to a pending user I/O */
#define RF_PSS_CREATE          0x00000010      /* tells LookupRUStatus to create the entry */
#define RF_PSS_BUFFERWAIT      0x00000020      /* someone is waiting for a buffer for this RU */

int rf_ConfigurePSStatus(RF_ShutdownList_t **listp, RF_Raid_t *raidPtr,
	RF_Config_t *cfgPtr);

RF_PSStatusHeader_t *rf_MakeParityStripeStatusTable(RF_Raid_t *raidPtr);
void rf_FreeParityStripeStatusTable(RF_Raid_t *raidPtr,
	RF_PSStatusHeader_t *pssTable);
RF_ReconParityStripeStatus_t *rf_LookupRUStatus(RF_Raid_t *raidPtr,
	RF_PSStatusHeader_t *pssTable, RF_StripeNum_t psID,
	RF_ReconUnitNum_t which_ru, RF_PSSFlags_t flags, int *created);
void rf_PSStatusDelete(RF_Raid_t *raidPtr, RF_PSStatusHeader_t *pssTable,
	RF_ReconParityStripeStatus_t *pssPtr);
void rf_RemoveFromActiveReconTable(RF_Raid_t *raidPtr, RF_RowCol_t row,
	RF_StripeNum_t psid, RF_ReconUnitNum_t which_ru);
RF_ReconParityStripeStatus_t *rf_AllocPSStatus(RF_Raid_t *raidPtr);
void rf_FreePSStatus(RF_Raid_t *raidPtr, RF_ReconParityStripeStatus_t *p);
void rf_PrintPSStatusTable(RF_Raid_t *raidPtr, RF_RowCol_t row);

#endif /* !_RF__RF_PSSTATUS_H_ */