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 | |