| 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 | |