1 /* $NetBSD: rf_stripelocks.h,v 1.8 2011/05/05 08:21:29 mrg 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 * stripelocks.h -- header file for locking stripes 32 * 33 * Note that these functions are called from the execution routines of certain 34 * DAG Nodes, and so they must be NON-BLOCKING to assure maximum parallelism 35 * in the DAG. Accordingly, when a node wants to acquire a lock, it calls 36 * AcquireStripeLock, supplying a pointer to a callback function. If the lock 37 * is free at the time of the call, 0 is returned, indicating that the lock 38 * has been acquired. If the lock is not free, 1 is returned, and a copy of 39 * the function pointer and argument are held in the lock table. When the 40 * lock becomes free, the callback function is invoked. 41 * 42 *****************************************************************************/ 43 44 #ifndef _RF__RF_STRIPELOCKS_H_ 45 #define _RF__RF_STRIPELOCKS_H_ 46 47 #include <sys/buf.h> 48 #include <dev/raidframe/raidframevar.h> 49 50 #include "rf_threadstuff.h" 51 #include "rf_general.h" 52 53 struct RF_LockReqDesc_s { 54 RF_IoType_t type; /* read or write */ 55 RF_int64 start, stop; /* start and end of range to be locked */ 56 RF_int64 start2, stop2; /* start and end of 2nd range to be locked */ 57 void (*cbFunc) (struct buf *); /* callback function */ 58 void *cbArg; /* argument to callback function */ 59 RF_LockReqDesc_t *next; /* next element in chain */ 60 RF_LockReqDesc_t *templink; /* for making short-lived lists of 61 * request descriptors */ 62 }; 63 #define RF_ASSERT_VALID_LOCKREQ(_lr_) { \ 64 RF_ASSERT(RF_IO_IS_R_OR_W((_lr_)->type)); \ 65 } 66 67 struct RF_StripeLockDesc_s { 68 RF_StripeNum_t stripeID;/* the stripe ID */ 69 RF_LockReqDesc_t *granted; /* unordered list of granted requests */ 70 RF_LockReqDesc_t *waitersH; /* FIFO queue of all waiting reqs, 71 * both read and write (Head and Tail) */ 72 RF_LockReqDesc_t *waitersT; 73 int nWriters; /* number of writers either granted or waiting */ 74 RF_StripeLockDesc_t *next; /* for hash table collision resolution */ 75 }; 76 77 struct RF_LockTableEntry_s { 78 rf_declare_mutex2(mutex); /* mutex on this hash chain */ 79 RF_StripeLockDesc_t *descList; /* hash chain of lock descriptors */ 80 }; 81 /* 82 * Initializes a stripe lock descriptor. _defSize is the number of sectors 83 * that we lock when there is no parity information in the ASM (e.g. RAID0). 84 */ 85 86 #define RF_INIT_LOCK_REQ_DESC(_lrd, _typ, _cbf, _cba, _asm, _defSize) \ 87 { \ 88 (_lrd).type = _typ; \ 89 (_lrd).start2 = -1; \ 90 (_lrd).stop2 = -1; \ 91 if ((_asm)->parityInfo) { \ 92 (_lrd).start = (_asm)->parityInfo->startSector; \ 93 (_lrd).stop = (_asm)->parityInfo->startSector + (_asm)->parityInfo->numSector-1; \ 94 if ((_asm)->parityInfo->next) { \ 95 (_lrd).start2 = (_asm)->parityInfo->next->startSector; \ 96 (_lrd).stop2 = (_asm)->parityInfo->next->startSector + (_asm)->parityInfo->next->numSector-1; \ 97 } \ 98 } else { \ 99 (_lrd).start = 0; \ 100 (_lrd).stop = (_defSize); \ 101 } \ 102 (_lrd).templink= NULL; \ 103 (_lrd).cbFunc = (_cbf); \ 104 (_lrd).cbArg = (void *) (_cba); \ 105 } 106 107 int rf_ConfigureStripeLockFreeList(RF_ShutdownList_t **); 108 int rf_ConfigureStripeLocks(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *); 109 int rf_AcquireStripeLock(RF_LockTableEntry_t *, RF_StripeNum_t, RF_LockReqDesc_t *); 110 void rf_ReleaseStripeLock(RF_LockTableEntry_t *, RF_StripeNum_t, RF_LockReqDesc_t *); 111 112 #endif /* !_RF__RF_STRIPELOCKS_H_ */ 113