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1.1 nbrk 1: /* $OpenBSD: rf_stripelocks.h,v 1.3 2002/12/16 07:01:05 tdeval Exp $ */
2: /* $NetBSD: rf_stripelocks.h,v 1.3 1999/02/05 00:06:18 oster Exp $ */
3:
4: /*
5: * Copyright (c) 1995 Carnegie-Mellon University.
6: * All rights reserved.
7: *
8: * Author: Mark Holland
9: *
10: * Permission to use, copy, modify and distribute this software and
11: * its documentation is hereby granted, provided that both the copyright
12: * notice and this permission notice appear in all copies of the
13: * software, derivative works or modified versions, and any portions
14: * thereof, and that both notices appear in supporting documentation.
15: *
16: * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
17: * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
18: * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
19: *
20: * Carnegie Mellon requests users of this software to return to
21: *
22: * Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
23: * School of Computer Science
24: * Carnegie Mellon University
25: * Pittsburgh PA 15213-3890
26: *
27: * any improvements or extensions that they make and grant Carnegie the
28: * rights to redistribute these changes.
29: */
30:
31: /*****************************************************************************
32: *
33: * stripelocks.h -- Header file for locking stripes.
34: *
35: * Note that these functions are called from the execution routines of certain
36: * DAG Nodes, and so they must be NON-BLOCKING to assure maximum parallelism
37: * in the DAG. Accordingly, when a node wants to acquire a lock, it calls
38: * AcquireStripeLock, supplying a pointer to a callback function. If the lock
39: * is free at the time of the call, 0 is returned, indicating that the lock
40: * has been acquired. If the lock is not free, 1 is returned, and a copy of
41: * the function pointer and argument are held in the lock table. When the
42: * lock becomes free, the callback function is invoked.
43: *
44: *****************************************************************************/
45:
46: #ifndef _RF__RF_STRIPELOCKS_H_
47: #define _RF__RF_STRIPELOCKS_H_
48:
49: #include <sys/buf.h>
50:
51: #include "rf_types.h"
52: #include "rf_threadstuff.h"
53: #include "rf_general.h"
54:
55: struct RF_LockReqDesc_s {
56: RF_IoType_t type; /* Read or write. */
57: RF_int64 start, stop; /*
58: * Start and end of range to
59: * be locked.
60: */
61: RF_int64 start2, stop2;/*
62: * Start and end of 2nd range
63: * to be locked.
64: */
65: void (*cbFunc) (struct buf *);
66: /* Callback function. */
67: void *cbArg; /*
68: * Argument to callback
69: * function.
70: */
71: RF_LockReqDesc_t *next; /* Next element in chain. */
72: RF_LockReqDesc_t *templink; /*
73: * For making short-lived lists
74: * of request descriptors.
75: */
76: };
77:
78: #define RF_ASSERT_VALID_LOCKREQ(_lr_) do { \
79: RF_ASSERT(RF_IO_IS_R_OR_W((_lr_)->type)); \
80: } while (0)
81:
82: struct RF_StripeLockDesc_s {
83: RF_StripeNum_t stripeID; /* The stripe ID. */
84: RF_LockReqDesc_t *granted; /*
85: * Unordered list of granted
86: * requests.
87: */
88: RF_LockReqDesc_t *waitersH; /* FIFO queue of all waiting
89: * reqs, both read and write
90: * (Head and Tail).
91: */
92: RF_LockReqDesc_t *waitersT;
93: int nWriters; /*
94: * Number of writers either
95: * granted or waiting.
96: */
97: RF_StripeLockDesc_t *next; /*
98: * For hash table collision
99: * resolution.
100: */
101: };
102:
103: struct RF_LockTableEntry_s {
104: RF_DECLARE_MUTEX (mutex); /* Mutex on this hash chain. */
105: RF_StripeLockDesc_t *descList; /*
106: * Hash chain of lock
107: * descriptors.
108: */
109: };
110:
111: /*
112: * Initializes a stripe lock descriptor. _defSize is the number of sectors
113: * that we lock when there is no parity information in the ASM (e.g. RAID0).
114: */
115:
116: #define RF_INIT_LOCK_REQ_DESC(_lrd, _typ, _cbf, _cba, _asm, _defSize) \
117: do { \
118: (_lrd).type = _typ; \
119: (_lrd).start2 = -1; \
120: (_lrd).stop2 = -1; \
121: if ((_asm)->parityInfo) { \
122: (_lrd).start = (_asm)->parityInfo->startSector; \
123: (_lrd).stop = (_asm)->parityInfo->startSector + \
124: (_asm)->parityInfo->numSector-1; \
125: if ((_asm)->parityInfo->next) { \
126: (_lrd).start2 = \
127: (_asm)->parityInfo->next->startSector; \
128: (_lrd).stop2 = \
129: (_asm)->parityInfo->next->startSector + \
130: (_asm)->parityInfo->next->numSector-1; \
131: } \
132: } else { \
133: (_lrd).start = 0; \
134: (_lrd).stop = (_defSize); \
135: } \
136: (_lrd).templink= NULL; \
137: (_lrd).cbFunc = (_cbf); \
138: (_lrd).cbArg = (void *) (_cba); \
139: } while (0)
140:
141: int rf_ConfigureStripeLockFreeList(RF_ShutdownList_t **);
142: RF_LockTableEntry_t *rf_MakeLockTable(void);
143: void rf_ShutdownStripeLocks(RF_LockTableEntry_t *);
144: int rf_ConfigureStripeLocks(RF_ShutdownList_t **, RF_Raid_t *, RF_Config_t *);
145: int rf_AcquireStripeLock(RF_LockTableEntry_t *, RF_StripeNum_t,
146: RF_LockReqDesc_t *);
147: void rf_ReleaseStripeLock(RF_LockTableEntry_t *, RF_StripeNum_t,
148: RF_LockReqDesc_t *);
149:
150: #endif /* !_RF__RF_STRIPELOCKS_H_ */