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rf_psstatus.h revision 1.13
      1 /*	$NetBSD: rf_psstatus.h,v 1.13 2006/02/14 01:13:33 oster Exp $	*/
      2 /*
      3  * Copyright (c) 1995 Carnegie-Mellon University.
      4  * All rights reserved.
      5  *
      6  * Author: Mark Holland
      7  *
      8  * Permission to use, copy, modify and distribute this software and
      9  * its documentation is hereby granted, provided that both the copyright
     10  * notice and this permission notice appear in all copies of the
     11  * software, derivative works or modified versions, and any portions
     12  * thereof, and that both notices appear in supporting documentation.
     13  *
     14  * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
     15  * CONDITION.  CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
     16  * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
     17  *
     18  * Carnegie Mellon requests users of this software to return to
     19  *
     20  *  Software Distribution Coordinator  or  Software.Distribution (at) CS.CMU.EDU
     21  *  School of Computer Science
     22  *  Carnegie Mellon University
     23  *  Pittsburgh PA 15213-3890
     24  *
     25  * any improvements or extensions that they make and grant Carnegie the
     26  * rights to redistribute these changes.
     27  */
     28 
     29 /*****************************************************************************
     30  *
     31  * psstatus.h
     32  *
     33  * The reconstruction code maintains a bunch of status related to the parity
     34  * stripes that are currently under reconstruction.  This header file defines
     35  * the status structures.
     36  *
     37  *****************************************************************************/
     38 
     39 #ifndef _RF__RF_PSSTATUS_H_
     40 #define _RF__RF_PSSTATUS_H_
     41 
     42 #include <dev/raidframe/raidframevar.h>
     43 
     44 #include "rf_threadstuff.h"
     45 #include "rf_callback.h"
     46 
     47 #define RF_PS_MAX_BUFS 10	/* max number of bufs we'll accumulate before
     48 				 * we do an XOR */
     49 
     50 #define RF_PSS_DEFAULT_TABLESIZE 200
     51 
     52 /*
     53  * Macros to acquire/release the mutex lock on a parity stripe status
     54  * descriptor. Note that we use just one lock for the whole hash chain.
     55  */
     56 #define RF_HASH_PSID(_raid_,_psid_) ( (_psid_) % ((_raid_)->pssTableSize) )	/* simple hash function */
     57 #define RF_LOCK_PSS_MUTEX(_raidPtr, _psid)                                                      \
     58   do {                                                                                          \
     59      RF_LOCK_MUTEX((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex);   \
     60      while((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].lock) {           \
     61           ltsleep(&(_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].lock,     \
     62 	          PRIBIO, "rflockpss", 0,                                                       \
     63 	          &(_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex);   \
     64      }                                                                                          \
     65      (_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].lock = 1;               \
     66      RF_UNLOCK_MUTEX((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex); \
     67   } while (0);
     68 
     69 #define RF_UNLOCK_PSS_MUTEX(_raidPtr, _psid)                                                    \
     70   RF_LOCK_MUTEX((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex);      \
     71   (_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].lock = 0;                  \
     72   wakeup(&(_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].lock);             \
     73   RF_UNLOCK_MUTEX((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex);
     74 
     75 struct RF_ReconParityStripeStatus_s {
     76 	RF_StripeNum_t parityStripeID;	/* the parity stripe ID */
     77 	RF_ReconUnitNum_t which_ru;	/* which reconstruction unit with the
     78 					 * indicated parity stripe */
     79 	RF_PSSFlags_t flags;	/* flags indicating various conditions */
     80 	void   *rbuf;		/* this is the accumulating xor sum */
     81 	void   *writeRbuf;	/* DEBUG ONLY:  a pointer to the rbuf after it
     82 				 * has filled & been sent to disk */
     83 	void   *rbufsForXor[RF_PS_MAX_BUFS];	/* these are buffers still to
     84 						 * be xored into the
     85 						 * accumulating sum */
     86 	int     xorBufCount;	/* num buffers waiting to be xored */
     87 	int     blockCount;	/* count of # proc that have blocked recon on
     88 				 * this parity stripe */
     89 	char   issued[RF_MAXCOL];	/* issued[i]==1 <=> column i has already
     90 				 * issued a read request for the indicated RU */
     91 	RF_CallbackDesc_t *procWaitList;	/* list of user procs waiting
     92 						 * for recon to be done */
     93 	RF_CallbackDesc_t *blockWaitList;	/* list of disks blocked
     94 						 * waiting for user write to
     95 						 * complete */
     96 	RF_CallbackDesc_t *bufWaitList;	/* list of disks blocked waiting to
     97 					 * acquire a buffer for this RU */
     98 	RF_ReconParityStripeStatus_t *next;
     99 };
    100 
    101 struct RF_PSStatusHeader_s {
    102 	RF_DECLARE_MUTEX(mutex)	/* mutex for this hash chain */
    103 	int lock;               /* 1 if this hash chain is locked,
    104 				   0 otherwise */
    105 	RF_ReconParityStripeStatus_t *chain;	/* the hash chain */
    106 };
    107 /* masks for the "flags" field above */
    108 #define RF_PSS_NONE            0x00000000	/* no flags */
    109 #define RF_PSS_UNDER_RECON     0x00000001	/* this parity stripe is
    110 						 * currently under
    111 						 * reconstruction */
    112 #define RF_PSS_FORCED_ON_WRITE 0x00000002	/* indicates a recon was
    113 						 * forced due to a user-write
    114 						 * operation */
    115 #define RF_PSS_FORCED_ON_READ  0x00000004	/* ditto for read, but not
    116 						 * currently implemented */
    117 #define RF_PSS_RECON_BLOCKED   0x00000008	/* reconstruction is currently
    118 						 * blocked due to a pending
    119 						 * user I/O */
    120 #define RF_PSS_CREATE          0x00000010	/* tells LookupRUStatus to
    121 						 * create the entry */
    122 #define RF_PSS_BUFFERWAIT      0x00000020	/* someone is waiting for a
    123 						 * buffer for this RU */
    124 
    125 int rf_ConfigurePSStatus(RF_ShutdownList_t **);
    126 void rf_InitPSStatus(RF_Raid_t *);
    127 RF_PSStatusHeader_t *rf_MakeParityStripeStatusTable(RF_Raid_t *);
    128 void rf_FreeParityStripeStatusTable(RF_Raid_t *, RF_PSStatusHeader_t *);
    129 RF_ReconParityStripeStatus_t *rf_LookupRUStatus(RF_Raid_t *, RF_PSStatusHeader_t *,
    130 						RF_StripeNum_t, RF_ReconUnitNum_t,
    131 						RF_PSSFlags_t,
    132 						RF_ReconParityStripeStatus_t *);
    133 void rf_PSStatusDelete(RF_Raid_t *, RF_PSStatusHeader_t *,
    134 		       RF_ReconParityStripeStatus_t *);
    135 void rf_RemoveFromActiveReconTable(RF_Raid_t *, RF_StripeNum_t, RF_ReconUnitNum_t);
    136 RF_ReconParityStripeStatus_t *rf_AllocPSStatus(RF_Raid_t *);
    137 void rf_FreePSStatus(RF_Raid_t *, RF_ReconParityStripeStatus_t *);
    138 void rf_PrintPSStatusTable(RF_Raid_t *);
    139 
    140 #endif				/* !_RF__RF_PSSTATUS_H_ */
    141