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rf_psstatus.h revision 1.9
      1 /*	$NetBSD: rf_psstatus.h,v 1.9 2004/03/18 16:54:54 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   RF_UNLOCK_MUTEX((_raidPtr)->reconControl->pssTable[ RF_HASH_PSID(_raidPtr,_psid) ].mutex);
     73 
     74 struct RF_ReconParityStripeStatus_s {
     75 	RF_StripeNum_t parityStripeID;	/* the parity stripe ID */
     76 	RF_ReconUnitNum_t which_ru;	/* which reconstruction unit with the
     77 					 * indicated parity stripe */
     78 	RF_PSSFlags_t flags;	/* flags indicating various conditions */
     79 	void   *rbuf;		/* this is the accumulating xor sum */
     80 	void   *writeRbuf;	/* DEBUG ONLY:  a pointer to the rbuf after it
     81 				 * has filled & been sent to disk */
     82 	void   *rbufsForXor[RF_PS_MAX_BUFS];	/* these are buffers still to
     83 						 * be xored into the
     84 						 * accumulating sum */
     85 	int     xorBufCount;	/* num buffers waiting to be xored */
     86 	int     blockCount;	/* count of # proc that have blocked recon on
     87 				 * this parity stripe */
     88 	char   issued[RF_MAXCOL];	/* issued[i]==1 <=> column i has already
     89 				 * issued a read request for the indicated RU */
     90 	RF_CallbackDesc_t *procWaitList;	/* list of user procs waiting
     91 						 * for recon to be done */
     92 	RF_CallbackDesc_t *blockWaitList;	/* list of disks blocked
     93 						 * waiting for user write to
     94 						 * complete */
     95 	RF_CallbackDesc_t *bufWaitList;	/* list of disks blocked waiting to
     96 					 * acquire a buffer for this RU */
     97 	RF_ReconParityStripeStatus_t *next;
     98 };
     99 
    100 struct RF_PSStatusHeader_s {
    101 	RF_DECLARE_MUTEX(mutex)	/* mutex for this hash chain */
    102 	int lock;               /* 1 if this hash chain is locked,
    103 				   0 otherwise */
    104 	RF_ReconParityStripeStatus_t *chain;	/* the hash chain */
    105 };
    106 /* masks for the "flags" field above */
    107 #define RF_PSS_NONE            0x00000000	/* no flags */
    108 #define RF_PSS_UNDER_RECON     0x00000001	/* this parity stripe is
    109 						 * currently under
    110 						 * reconstruction */
    111 #define RF_PSS_FORCED_ON_WRITE 0x00000002	/* indicates a recon was
    112 						 * forced due to a user-write
    113 						 * operation */
    114 #define RF_PSS_FORCED_ON_READ  0x00000004	/* ditto for read, but not
    115 						 * currently implemented */
    116 #define RF_PSS_RECON_BLOCKED   0x00000008	/* reconstruction is currently
    117 						 * blocked due to a pending
    118 						 * user I/O */
    119 #define RF_PSS_CREATE          0x00000010	/* tells LookupRUStatus to
    120 						 * create the entry */
    121 #define RF_PSS_BUFFERWAIT      0x00000020	/* someone is waiting for a
    122 						 * buffer for this RU */
    123 
    124 int rf_ConfigurePSStatus(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *);
    125 RF_PSStatusHeader_t *rf_MakeParityStripeStatusTable(RF_Raid_t *);
    126 void rf_FreeParityStripeStatusTable(RF_Raid_t *, RF_PSStatusHeader_t *);
    127 RF_ReconParityStripeStatus_t *rf_LookupRUStatus(RF_Raid_t *, RF_PSStatusHeader_t *,
    128 						RF_StripeNum_t, RF_ReconUnitNum_t,
    129 						RF_PSSFlags_t,
    130 						RF_ReconParityStripeStatus_t *);
    131 void rf_PSStatusDelete(RF_Raid_t *, RF_PSStatusHeader_t *,
    132 		       RF_ReconParityStripeStatus_t *);
    133 void rf_RemoveFromActiveReconTable(RF_Raid_t *, RF_StripeNum_t, RF_ReconUnitNum_t);
    134 RF_ReconParityStripeStatus_t *rf_AllocPSStatus(RF_Raid_t *);
    135 void rf_FreePSStatus(RF_Raid_t *, RF_ReconParityStripeStatus_t *);
    136 void rf_PrintPSStatusTable(RF_Raid_t *);
    137 
    138 #endif				/* !_RF__RF_PSSTATUS_H_ */
    139