sys/dev/raidframe/rf_psstatus.h

   1 /*      $NetBSD: rf_psstatus.h,v 1.12 2005/12/11 12:23:37 christos 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@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_ */