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_ */