NetBSD/sys/dev/raidframe/rf_stripelocks.h

119 lines
5.7 KiB
C

/* $NetBSD: rf_stripelocks.h,v 1.5 2003/04/10 04:10:17 simonb Exp $ */
/*
* Copyright (c) 1995 Carnegie-Mellon University.
* All rights reserved.
*
* Author: Mark Holland
*
* Permission to use, copy, modify and distribute this software and
* its documentation is hereby granted, provided that both the copyright
* notice and this permission notice appear in all copies of the
* software, derivative works or modified versions, and any portions
* thereof, and that both notices appear in supporting documentation.
*
* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
*
* Carnegie Mellon requests users of this software to return to
*
* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
* School of Computer Science
* Carnegie Mellon University
* Pittsburgh PA 15213-3890
*
* any improvements or extensions that they make and grant Carnegie the
* rights to redistribute these changes.
*/
/*****************************************************************************
*
* stripelocks.h -- header file for locking stripes
*
* Note that these functions are called from the execution routines of certain
* DAG Nodes, and so they must be NON-BLOCKING to assure maximum parallelism
* in the DAG. Accordingly, when a node wants to acquire a lock, it calls
* AcquireStripeLock, supplying a pointer to a callback function. If the lock
* is free at the time of the call, 0 is returned, indicating that the lock
* has been acquired. If the lock is not free, 1 is returned, and a copy of
* the function pointer and argument are held in the lock table. When the
* lock becomes free, the callback function is invoked.
*
*****************************************************************************/
#ifndef _RF__RF_STRIPELOCKS_H_
#define _RF__RF_STRIPELOCKS_H_
#include <sys/buf.h>
#include <dev/raidframe/raidframevar.h>
#include "rf_threadstuff.h"
#include "rf_general.h"
struct RF_LockReqDesc_s {
RF_IoType_t type; /* read or write */
RF_int64 start, stop; /* start and end of range to be locked */
RF_int64 start2, stop2; /* start and end of 2nd range to be locked */
void (*cbFunc) (struct buf *); /* callback function */
void *cbArg; /* argument to callback function */
RF_LockReqDesc_t *next; /* next element in chain */
RF_LockReqDesc_t *templink; /* for making short-lived lists of
* request descriptors */
};
#define RF_ASSERT_VALID_LOCKREQ(_lr_) { \
RF_ASSERT(RF_IO_IS_R_OR_W((_lr_)->type)); \
}
struct RF_StripeLockDesc_s {
RF_StripeNum_t stripeID;/* the stripe ID */
RF_LockReqDesc_t *granted; /* unordered list of granted requests */
RF_LockReqDesc_t *waitersH; /* FIFO queue of all waiting reqs,
* both read and write (Head and Tail) */
RF_LockReqDesc_t *waitersT;
int nWriters; /* number of writers either granted or waiting */
RF_StripeLockDesc_t *next; /* for hash table collision resolution */
};
struct RF_LockTableEntry_s {
RF_DECLARE_MUTEX(mutex) /* mutex on this hash chain */
RF_StripeLockDesc_t *descList; /* hash chain of lock descriptors */
};
/*
* Initializes a stripe lock descriptor. _defSize is the number of sectors
* that we lock when there is no parity information in the ASM (e.g. RAID0).
*/
#define RF_INIT_LOCK_REQ_DESC(_lrd, _typ, _cbf, _cba, _asm, _defSize) \
{ \
(_lrd).type = _typ; \
(_lrd).start2 = -1; \
(_lrd).stop2 = -1; \
if ((_asm)->parityInfo) { \
(_lrd).start = (_asm)->parityInfo->startSector; \
(_lrd).stop = (_asm)->parityInfo->startSector + (_asm)->parityInfo->numSector-1; \
if ((_asm)->parityInfo->next) { \
(_lrd).start2 = (_asm)->parityInfo->next->startSector; \
(_lrd).stop2 = (_asm)->parityInfo->next->startSector + (_asm)->parityInfo->next->numSector-1; \
} \
} else { \
(_lrd).start = 0; \
(_lrd).stop = (_defSize); \
} \
(_lrd).templink= NULL; \
(_lrd).cbFunc = (_cbf); \
(_lrd).cbArg = (void *) (_cba); \
}
int rf_ConfigureStripeLockFreeList(RF_ShutdownList_t ** listp);
int
rf_ConfigureStripeLocks(RF_ShutdownList_t ** listp, RF_Raid_t * raidPtr,
RF_Config_t * cfgPtr);
int
rf_AcquireStripeLock(RF_LockTableEntry_t * lockTable,
RF_StripeNum_t stripeID, RF_LockReqDesc_t * lockReqDesc);
void
rf_ReleaseStripeLock(RF_LockTableEntry_t * lockTable,
RF_StripeNum_t stripeID, RF_LockReqDesc_t * lockReqDesc);
#endif /* !_RF__RF_STRIPELOCKS_H_ */