706 lines
24 KiB
C
706 lines
24 KiB
C
/* $NetBSD: rf_stripelocks.c,v 1.15 2002/09/23 04:34:46 oster Exp $ */
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/*
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* Copyright (c) 1995 Carnegie-Mellon University.
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* All rights reserved.
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*
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* Authors: Mark Holland, Jim Zelenka
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*
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* Permission to use, copy, modify and distribute this software and
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* its documentation is hereby granted, provided that both the copyright
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* notice and this permission notice appear in all copies of the
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* software, derivative works or modified versions, and any portions
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* thereof, and that both notices appear in supporting documentation.
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*
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* CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
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* CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
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* FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
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*
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* Carnegie Mellon requests users of this software to return to
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*
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* Software Distribution Coordinator or Software.Distribution@CS.CMU.EDU
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* School of Computer Science
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* Carnegie Mellon University
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* Pittsburgh PA 15213-3890
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*
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* any improvements or extensions that they make and grant Carnegie the
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* rights to redistribute these changes.
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*/
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/*
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* stripelocks.c -- code to lock stripes for read and write access
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*
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* The code distinguishes between read locks and write locks. There can be
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* as many readers to given stripe as desired. When a write request comes
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* in, no further readers are allowed to enter, and all subsequent requests
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* are queued in FIFO order. When a the number of readers goes to zero, the
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* writer is given the lock. When a writer releases the lock, the list of
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* queued requests is scanned, and all readersq up to the next writer are
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* given the lock.
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*
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* The lock table size must be one less than a power of two, but HASH_STRIPEID
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* is the only function that requires this.
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*
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* The code now supports "range locks". When you ask to lock a stripe, you
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* specify a range of addresses in that stripe that you want to lock. When
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* you acquire the lock, you've locked only this range of addresses, and
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* other threads can concurrently read/write any non-overlapping portions
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* of the stripe. The "addresses" that you lock are abstract in that you
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* can pass in anything you like. The expectation is that you'll pass in
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* the range of physical disk offsets of the parity bits you're planning
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* to update. The idea behind this, of course, is to allow sub-stripe
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* locking. The implementation is perhaps not the best imaginable; in the
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* worst case a lock release is O(n^2) in the total number of outstanding
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* requests to a given stripe. Note that if you're striping with a
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* stripe unit size equal to an entire disk (i.e. not striping), there will
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* be only one stripe and you may spend some significant number of cycles
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* searching through stripe lock descriptors.
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*/
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#include <sys/cdefs.h>
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__KERNEL_RCSID(0, "$NetBSD: rf_stripelocks.c,v 1.15 2002/09/23 04:34:46 oster Exp $");
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#include <dev/raidframe/raidframevar.h>
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#include "rf_raid.h"
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#include "rf_stripelocks.h"
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#include "rf_alloclist.h"
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#include "rf_debugprint.h"
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#include "rf_general.h"
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#include "rf_freelist.h"
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#include "rf_driver.h"
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#include "rf_shutdown.h"
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#ifdef DEBUG
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#define Dprintf1(s,a) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
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#define Dprintf2(s,a,b) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL)
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#define Dprintf3(s,a,b,c) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),NULL,NULL,NULL,NULL,NULL)
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#define Dprintf4(s,a,b,c,d) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),NULL,NULL,NULL,NULL)
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#define Dprintf5(s,a,b,c,d,e) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),NULL,NULL,NULL)
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#define Dprintf6(s,a,b,c,d,e,f) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),NULL,NULL)
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#define Dprintf7(s,a,b,c,d,e,f,g) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),NULL)
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#define Dprintf8(s,a,b,c,d,e,f,g,h) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),(void *)((unsigned long)c),(void *)((unsigned long)d),(void *)((unsigned long)e),(void *)((unsigned long)f),(void *)((unsigned long)g),(void *)((unsigned long)h))
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#else /* DEBUG */
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#define Dprintf1(s,a) {}
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#define Dprintf2(s,a,b) {}
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#define Dprintf3(s,a,b,c) {}
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#define Dprintf4(s,a,b,c,d) {}
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#define Dprintf5(s,a,b,c,d,e) {}
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#define Dprintf6(s,a,b,c,d,e,f) {}
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#define Dprintf7(s,a,b,c,d,e,f,g) {}
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#define Dprintf8(s,a,b,c,d,e,f,g,h) {}
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#endif /* DEBUG */
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#define FLUSH
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#define HASH_STRIPEID(_sid_) ( (_sid_) & (rf_lockTableSize-1) )
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static void AddToWaitersQueue(RF_StripeLockDesc_t * lockDesc, RF_LockReqDesc_t * lockReqDesc);
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static RF_StripeLockDesc_t *AllocStripeLockDesc(RF_StripeNum_t stripeID);
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static void FreeStripeLockDesc(RF_StripeLockDesc_t * p);
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#if RF_DEBUG_STRIPELOCK
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static void PrintLockedStripes(RF_LockTableEntry_t * lockTable);
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#endif
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/* determines if two ranges overlap. always yields false if either start value is negative */
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#define SINGLE_RANGE_OVERLAP(_strt1, _stop1, _strt2, _stop2) \
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( (_strt1 >= 0) && (_strt2 >= 0) && (RF_MAX(_strt1, _strt2) <= RF_MIN(_stop1, _stop2)) )
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/* determines if any of the ranges specified in the two lock descriptors overlap each other */
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#define RANGE_OVERLAP(_cand, _pred) \
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( SINGLE_RANGE_OVERLAP((_cand)->start, (_cand)->stop, (_pred)->start, (_pred)->stop ) || \
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SINGLE_RANGE_OVERLAP((_cand)->start2, (_cand)->stop2, (_pred)->start, (_pred)->stop ) || \
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SINGLE_RANGE_OVERLAP((_cand)->start, (_cand)->stop, (_pred)->start2, (_pred)->stop2) || \
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SINGLE_RANGE_OVERLAP((_cand)->start2, (_cand)->stop2, (_pred)->start2, (_pred)->stop2) )
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/* Determines if a candidate lock request conflicts with a predecessor lock req.
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* Note that the arguments are not interchangeable.
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* The rules are:
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* a candidate read conflicts with a predecessor write if any ranges overlap
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* a candidate write conflicts with a predecessor read if any ranges overlap
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* a candidate write conflicts with a predecessor write if any ranges overlap
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*/
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#define STRIPELOCK_CONFLICT(_cand, _pred) \
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RANGE_OVERLAP((_cand), (_pred)) && \
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( ( (((_cand)->type == RF_IO_TYPE_READ) && ((_pred)->type == RF_IO_TYPE_WRITE)) || \
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(((_cand)->type == RF_IO_TYPE_WRITE) && ((_pred)->type == RF_IO_TYPE_READ)) || \
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(((_cand)->type == RF_IO_TYPE_WRITE) && ((_pred)->type == RF_IO_TYPE_WRITE)) \
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) \
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)
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static RF_FreeList_t *rf_stripelock_freelist;
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#define RF_MAX_FREE_STRIPELOCK 128
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#define RF_STRIPELOCK_INC 8
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#define RF_STRIPELOCK_INITIAL 32
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static void rf_ShutdownStripeLockFreeList(void *);
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static void rf_RaidShutdownStripeLocks(void *);
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static void
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rf_ShutdownStripeLockFreeList(ignored)
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void *ignored;
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{
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RF_FREELIST_DESTROY(rf_stripelock_freelist, next, (RF_StripeLockDesc_t *));
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}
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int
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rf_ConfigureStripeLockFreeList(listp)
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RF_ShutdownList_t **listp;
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{
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unsigned mask;
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int rc;
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RF_FREELIST_CREATE(rf_stripelock_freelist, RF_MAX_FREE_STRIPELOCK,
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RF_STRIPELOCK_INITIAL, sizeof(RF_StripeLockDesc_t));
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rc = rf_ShutdownCreate(listp, rf_ShutdownStripeLockFreeList, NULL);
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if (rc) {
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rf_print_unable_to_add_shutdown(__FILE__, __LINE__, rc);
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rf_ShutdownStripeLockFreeList(NULL);
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return (rc);
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}
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RF_FREELIST_PRIME(rf_stripelock_freelist, RF_STRIPELOCK_INITIAL, next,
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(RF_StripeLockDesc_t *));
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for (mask = 0x1; mask; mask <<= 1)
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if (rf_lockTableSize == mask)
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break;
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if (!mask) {
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printf("[WARNING: lock table size must be a power of two. Setting to %d.]\n", RF_DEFAULT_LOCK_TABLE_SIZE);
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rf_lockTableSize = RF_DEFAULT_LOCK_TABLE_SIZE;
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}
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return (0);
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}
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RF_LockTableEntry_t *
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rf_MakeLockTable()
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{
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RF_LockTableEntry_t *lockTable;
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int i, rc;
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RF_Calloc(lockTable, ((int) rf_lockTableSize), sizeof(RF_LockTableEntry_t), (RF_LockTableEntry_t *));
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if (lockTable == NULL)
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return (NULL);
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for (i = 0; i < rf_lockTableSize; i++) {
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rc = rf_mutex_init(&lockTable[i].mutex);
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if (rc) {
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rf_print_unable_to_init_mutex(__FILE__, __LINE__, rc);
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/* XXX clean up other mutexes */
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return (NULL);
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}
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}
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return (lockTable);
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}
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void
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rf_ShutdownStripeLocks(RF_LockTableEntry_t * lockTable)
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{
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int i;
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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PrintLockedStripes(lockTable);
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}
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#endif
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for (i = 0; i < rf_lockTableSize; i++) {
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rf_mutex_destroy(&lockTable[i].mutex);
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}
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RF_Free(lockTable, rf_lockTableSize * sizeof(RF_LockTableEntry_t));
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}
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static void
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rf_RaidShutdownStripeLocks(arg)
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void *arg;
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{
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RF_Raid_t *raidPtr = (RF_Raid_t *) arg;
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rf_ShutdownStripeLocks(raidPtr->lockTable);
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}
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int
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rf_ConfigureStripeLocks(
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RF_ShutdownList_t ** listp,
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RF_Raid_t * raidPtr,
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RF_Config_t * cfgPtr)
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{
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int rc;
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raidPtr->lockTable = rf_MakeLockTable();
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if (raidPtr->lockTable == NULL)
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return (ENOMEM);
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rc = rf_ShutdownCreate(listp, rf_RaidShutdownStripeLocks, raidPtr);
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if (rc) {
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rf_print_unable_to_add_shutdown(__FILE__, __LINE__, rc);
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rf_ShutdownStripeLocks(raidPtr->lockTable);
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return (rc);
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}
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return (0);
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}
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/* returns 0 if you've got the lock, and non-zero if you have to wait.
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* if and only if you have to wait, we'll cause cbFunc to get invoked
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* with cbArg when you are granted the lock. We store a tag in *releaseTag
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* that you need to give back to us when you release the lock.
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*/
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int
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rf_AcquireStripeLock(
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RF_LockTableEntry_t * lockTable,
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RF_StripeNum_t stripeID,
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RF_LockReqDesc_t * lockReqDesc)
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{
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RF_StripeLockDesc_t *lockDesc;
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RF_LockReqDesc_t *p;
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#if defined(DEBUG) && (RF_DEBUG_STRIPELOCK > 0)
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int tid = 0;
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#endif
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int hashval = HASH_STRIPEID(stripeID);
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int retcode = 0;
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RF_ASSERT(RF_IO_IS_R_OR_W(lockReqDesc->type));
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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if (stripeID == -1) {
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Dprintf1("[%d] Lock acquisition supressed (stripeID == -1)\n", tid);
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} else {
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Dprintf8("[%d] Trying to acquire stripe lock table 0x%lx SID %ld type %c range %ld-%ld, range2 %ld-%ld hashval %d\n",
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tid, (unsigned long) lockTable, stripeID, lockReqDesc->type, lockReqDesc->start,
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lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2);
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Dprintf3("[%d] lock %ld hashval %d\n", tid, stripeID, hashval);
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FLUSH;
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}
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}
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#endif
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if (stripeID == -1)
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return (0);
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lockReqDesc->next = NULL; /* just to be sure */
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RF_LOCK_MUTEX(lockTable[hashval].mutex);
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for (lockDesc = lockTable[hashval].descList; lockDesc; lockDesc = lockDesc->next) {
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if (lockDesc->stripeID == stripeID)
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break;
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}
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if (!lockDesc) { /* no entry in table => no one reading or
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* writing */
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lockDesc = AllocStripeLockDesc(stripeID);
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lockDesc->next = lockTable[hashval].descList;
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lockTable[hashval].descList = lockDesc;
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if (lockReqDesc->type == RF_IO_TYPE_WRITE)
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lockDesc->nWriters++;
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lockDesc->granted = lockReqDesc;
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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Dprintf7("[%d] no one waiting: lock %ld %c %ld-%ld %ld-%ld granted\n",
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tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2);
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FLUSH;
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}
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#endif
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} else {
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if (lockReqDesc->type == RF_IO_TYPE_WRITE)
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lockDesc->nWriters++;
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if (lockDesc->nWriters == 0) { /* no need to search any lists
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* if there are no writers
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* anywhere */
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lockReqDesc->next = lockDesc->granted;
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lockDesc->granted = lockReqDesc;
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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Dprintf7("[%d] no writers: lock %ld %c %ld-%ld %ld-%ld granted\n",
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tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2);
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FLUSH;
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}
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#endif
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} else {
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/* search the granted & waiting lists for a conflict.
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* stop searching as soon as we find one */
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retcode = 0;
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for (p = lockDesc->granted; p; p = p->next)
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if (STRIPELOCK_CONFLICT(lockReqDesc, p)) {
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retcode = 1;
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break;
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}
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if (!retcode)
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for (p = lockDesc->waitersH; p; p = p->next)
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if (STRIPELOCK_CONFLICT(lockReqDesc, p)) {
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retcode = 2;
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break;
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}
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if (!retcode) {
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lockReqDesc->next = lockDesc->granted; /* no conflicts found =>
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* grant lock */
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lockDesc->granted = lockReqDesc;
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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Dprintf7("[%d] no conflicts: lock %ld %c %ld-%ld %ld-%ld granted\n",
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tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop,
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lockReqDesc->start2, lockReqDesc->stop2);
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FLUSH;
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}
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#endif
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} else {
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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Dprintf6("[%d] conflict: lock %ld %c %ld-%ld hashval=%d not granted\n",
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tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop,
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hashval);
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Dprintf3("[%d] lock %ld retcode=%d\n", tid, stripeID, retcode);
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FLUSH;
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}
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#endif
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AddToWaitersQueue(lockDesc, lockReqDesc);
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/* conflict => the current access must wait */
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}
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}
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}
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RF_UNLOCK_MUTEX(lockTable[hashval].mutex);
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return (retcode);
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}
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void
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rf_ReleaseStripeLock(
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RF_LockTableEntry_t * lockTable,
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RF_StripeNum_t stripeID,
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RF_LockReqDesc_t * lockReqDesc)
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{
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RF_StripeLockDesc_t *lockDesc, *ld_t;
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RF_LockReqDesc_t *lr, *lr_t, *callbacklist, *t;
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#if defined(DEBUG) && (RF_DEBUG_STRIPELOCK > 0)
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int tid = 0;
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#endif
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int hashval = HASH_STRIPEID(stripeID);
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int release_it, consider_it;
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RF_LockReqDesc_t *candidate, *candidate_t, *predecessor;
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RF_ASSERT(RF_IO_IS_R_OR_W(lockReqDesc->type));
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#if RF_DEBUG_STRIPELOCK
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if (rf_stripeLockDebug) {
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if (stripeID == -1) {
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Dprintf1("[%d] Lock release supressed (stripeID == -1)\n", tid);
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} else {
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Dprintf8("[%d] Releasing stripe lock on stripe ID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
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tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2, lockTable);
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FLUSH;
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}
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}
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#endif
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if (stripeID == -1)
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return;
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RF_LOCK_MUTEX(lockTable[hashval].mutex);
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/* find the stripe lock descriptor */
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for (ld_t = NULL, lockDesc = lockTable[hashval].descList; lockDesc; ld_t = lockDesc, lockDesc = lockDesc->next) {
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if (lockDesc->stripeID == stripeID)
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break;
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}
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RF_ASSERT(lockDesc); /* major error to release a lock that doesn't
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* exist */
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/* find the stripe lock request descriptor & delete it from the list */
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for (lr_t = NULL, lr = lockDesc->granted; lr; lr_t = lr, lr = lr->next)
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if (lr == lockReqDesc)
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break;
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RF_ASSERT(lr && (lr == lockReqDesc)); /* major error to release a
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* lock that hasn't been
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* granted */
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if (lr_t)
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lr_t->next = lr->next;
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else {
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RF_ASSERT(lr == lockDesc->granted);
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lockDesc->granted = lr->next;
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}
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lr->next = NULL;
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if (lockReqDesc->type == RF_IO_TYPE_WRITE)
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lockDesc->nWriters--;
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/* search through the waiters list to see if anyone needs to be woken
|
|
* up. for each such descriptor in the wait list, we check it against
|
|
* everything granted and against everything _in front_ of it in the
|
|
* waiters queue. If it conflicts with none of these, we release it.
|
|
*
|
|
* DON'T TOUCH THE TEMPLINK POINTER OF ANYTHING IN THE GRANTED LIST HERE.
|
|
* This will roach the case where the callback tries to acquire a new
|
|
* lock in the same stripe. There are some asserts to try and detect
|
|
* this.
|
|
*
|
|
* We apply 2 performance optimizations: (1) if releasing this lock
|
|
* results in no more writers to this stripe, we just release
|
|
* everybody waiting, since we place no restrictions on the number of
|
|
* concurrent reads. (2) we consider as candidates for wakeup only
|
|
* those waiters that have a range overlap with either the descriptor
|
|
* being woken up or with something in the callbacklist (i.e.
|
|
* something we've just now woken up). This allows us to avoid the
|
|
* long evaluation for some descriptors. */
|
|
|
|
callbacklist = NULL;
|
|
if (lockDesc->nWriters == 0) { /* performance tweak (1) */
|
|
while (lockDesc->waitersH) {
|
|
|
|
lr = lockDesc->waitersH; /* delete from waiters
|
|
* list */
|
|
lockDesc->waitersH = lr->next;
|
|
|
|
RF_ASSERT(lr->type == RF_IO_TYPE_READ);
|
|
|
|
lr->next = lockDesc->granted; /* add to granted list */
|
|
lockDesc->granted = lr;
|
|
|
|
RF_ASSERT(!lr->templink);
|
|
lr->templink = callbacklist; /* put on callback list
|
|
* so that we'll invoke
|
|
* callback below */
|
|
callbacklist = lr;
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf8("[%d] No writers: granting lock stripe ID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
|
|
tid, stripeID, lr->type, lr->start, lr->stop, lr->start2, lr->stop2, (unsigned long) lockTable);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
}
|
|
lockDesc->waitersT = NULL; /* we've purged the whole
|
|
* waiters list */
|
|
|
|
} else
|
|
for (candidate_t = NULL, candidate = lockDesc->waitersH; candidate;) {
|
|
|
|
/* performance tweak (2) */
|
|
consider_it = 0;
|
|
if (RANGE_OVERLAP(lockReqDesc, candidate))
|
|
consider_it = 1;
|
|
else
|
|
for (t = callbacklist; t; t = t->templink)
|
|
if (RANGE_OVERLAP(t, candidate)) {
|
|
consider_it = 1;
|
|
break;
|
|
}
|
|
if (!consider_it) {
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf8("[%d] No overlap: rejecting candidate stripeID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
|
|
tid, stripeID, candidate->type, candidate->start, candidate->stop, candidate->start2, candidate->stop2,
|
|
(unsigned long) lockTable);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
candidate_t = candidate;
|
|
candidate = candidate->next;
|
|
continue;
|
|
}
|
|
/* we have a candidate for release. check to make
|
|
* sure it is not blocked by any granted locks */
|
|
release_it = 1;
|
|
for (predecessor = lockDesc->granted; predecessor; predecessor = predecessor->next) {
|
|
if (STRIPELOCK_CONFLICT(candidate, predecessor)) {
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf8("[%d] Conflicts with granted lock: rejecting candidate stripeID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
|
|
tid, stripeID, candidate->type, candidate->start, candidate->stop, candidate->start2, candidate->stop2,
|
|
(unsigned long) lockTable);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
release_it = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* now check to see if the candidate is blocked by any
|
|
* waiters that occur before it it the wait queue */
|
|
if (release_it)
|
|
for (predecessor = lockDesc->waitersH; predecessor != candidate; predecessor = predecessor->next) {
|
|
if (STRIPELOCK_CONFLICT(candidate, predecessor)) {
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf8("[%d] Conflicts with waiting lock: rejecting candidate stripeID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
|
|
tid, stripeID, candidate->type, candidate->start, candidate->stop, candidate->start2, candidate->stop2,
|
|
(unsigned long) lockTable);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
release_it = 0;
|
|
break;
|
|
}
|
|
}
|
|
|
|
/* release it if indicated */
|
|
if (release_it) {
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf8("[%d] Granting lock to candidate stripeID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n",
|
|
tid, stripeID, candidate->type, candidate->start, candidate->stop, candidate->start2, candidate->stop2,
|
|
(unsigned long) lockTable);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
if (candidate_t) {
|
|
candidate_t->next = candidate->next;
|
|
if (lockDesc->waitersT == candidate)
|
|
lockDesc->waitersT = candidate_t; /* cannot be waitersH since candidate_t is not NULL */
|
|
} else {
|
|
RF_ASSERT(candidate == lockDesc->waitersH);
|
|
lockDesc->waitersH = lockDesc->waitersH->next;
|
|
if (!lockDesc->waitersH)
|
|
lockDesc->waitersT = NULL;
|
|
}
|
|
candidate->next = lockDesc->granted; /* move it to the
|
|
* granted list */
|
|
lockDesc->granted = candidate;
|
|
|
|
RF_ASSERT(!candidate->templink);
|
|
candidate->templink = callbacklist; /* put it on the list of
|
|
* things to be called
|
|
* after we release the
|
|
* mutex */
|
|
callbacklist = candidate;
|
|
|
|
if (!candidate_t)
|
|
candidate = lockDesc->waitersH;
|
|
else
|
|
candidate = candidate_t->next; /* continue with the
|
|
* rest of the list */
|
|
} else {
|
|
candidate_t = candidate;
|
|
candidate = candidate->next; /* continue with the
|
|
* rest of the list */
|
|
}
|
|
}
|
|
|
|
/* delete the descriptor if no one is waiting or active */
|
|
if (!lockDesc->granted && !lockDesc->waitersH) {
|
|
RF_ASSERT(lockDesc->nWriters == 0);
|
|
#if RF_DEBUG_STRIPELOCK
|
|
if (rf_stripeLockDebug) {
|
|
Dprintf3("[%d] Last lock released (table 0x%lx): deleting desc for stripeID %ld\n", tid, (unsigned long) lockTable, stripeID);
|
|
FLUSH;
|
|
}
|
|
#endif
|
|
if (ld_t)
|
|
ld_t->next = lockDesc->next;
|
|
else {
|
|
RF_ASSERT(lockDesc == lockTable[hashval].descList);
|
|
lockTable[hashval].descList = lockDesc->next;
|
|
}
|
|
FreeStripeLockDesc(lockDesc);
|
|
lockDesc = NULL;/* only for the ASSERT below */
|
|
}
|
|
RF_UNLOCK_MUTEX(lockTable[hashval].mutex);
|
|
|
|
/* now that we've unlocked the mutex, invoke the callback on all the
|
|
* descriptors in the list */
|
|
RF_ASSERT(!((callbacklist) && (!lockDesc))); /* if we deleted the
|
|
* descriptor, we should
|
|
* have no callbacks to
|
|
* do */
|
|
for (candidate = callbacklist; candidate;) {
|
|
t = candidate;
|
|
candidate = candidate->templink;
|
|
t->templink = NULL;
|
|
(t->cbFunc) (t->cbArg);
|
|
}
|
|
}
|
|
/* must have the indicated lock table mutex upon entry */
|
|
static void
|
|
AddToWaitersQueue(
|
|
RF_StripeLockDesc_t * lockDesc,
|
|
RF_LockReqDesc_t * lockReqDesc)
|
|
{
|
|
if (!lockDesc->waitersH) {
|
|
lockDesc->waitersH = lockDesc->waitersT = lockReqDesc;
|
|
} else {
|
|
lockDesc->waitersT->next = lockReqDesc;
|
|
lockDesc->waitersT = lockReqDesc;
|
|
}
|
|
}
|
|
|
|
static RF_StripeLockDesc_t *
|
|
AllocStripeLockDesc(RF_StripeNum_t stripeID)
|
|
{
|
|
RF_StripeLockDesc_t *p;
|
|
|
|
RF_FREELIST_GET(rf_stripelock_freelist, p, next, (RF_StripeLockDesc_t *));
|
|
if (p) {
|
|
p->stripeID = stripeID;
|
|
}
|
|
return (p);
|
|
}
|
|
|
|
static void
|
|
FreeStripeLockDesc(RF_StripeLockDesc_t * p)
|
|
{
|
|
RF_FREELIST_FREE(rf_stripelock_freelist, p, next);
|
|
}
|
|
|
|
#if RF_DEBUG_STRIPELOCK
|
|
static void
|
|
PrintLockedStripes(lockTable)
|
|
RF_LockTableEntry_t *lockTable;
|
|
{
|
|
int i, j, foundone = 0, did;
|
|
RF_StripeLockDesc_t *p;
|
|
RF_LockReqDesc_t *q;
|
|
|
|
RF_LOCK_MUTEX(rf_printf_mutex);
|
|
printf("Locked stripes:\n");
|
|
for (i = 0; i < rf_lockTableSize; i++)
|
|
if (lockTable[i].descList) {
|
|
foundone = 1;
|
|
for (p = lockTable[i].descList; p; p = p->next) {
|
|
printf("Stripe ID 0x%lx (%d) nWriters %d\n",
|
|
(long) p->stripeID, (int) p->stripeID, p->nWriters);
|
|
|
|
if (!(p->granted))
|
|
printf("Granted: (none)\n");
|
|
else
|
|
printf("Granted:\n");
|
|
for (did = 1, j = 0, q = p->granted; q; j++, q = q->next) {
|
|
printf(" %c(%ld-%ld", q->type, (long) q->start, (long) q->stop);
|
|
if (q->start2 != -1)
|
|
printf(",%ld-%ld) ", (long) q->start2,
|
|
(long) q->stop2);
|
|
else
|
|
printf(") ");
|
|
if (j && !(j % 4)) {
|
|
printf("\n");
|
|
did = 1;
|
|
} else
|
|
did = 0;
|
|
}
|
|
if (!did)
|
|
printf("\n");
|
|
|
|
if (!(p->waitersH))
|
|
printf("Waiting: (none)\n");
|
|
else
|
|
printf("Waiting:\n");
|
|
for (did = 1, j = 0, q = p->waitersH; q; j++, q = q->next) {
|
|
printf("%c(%ld-%ld", q->type, (long) q->start, (long) q->stop);
|
|
if (q->start2 != -1)
|
|
printf(",%ld-%ld) ", (long) q->start2, (long) q->stop2);
|
|
else
|
|
printf(") ");
|
|
if (j && !(j % 4)) {
|
|
printf("\n ");
|
|
did = 1;
|
|
} else
|
|
did = 0;
|
|
}
|
|
if (!did)
|
|
printf("\n");
|
|
}
|
|
}
|
|
if (!foundone)
|
|
printf("(none)\n");
|
|
else
|
|
printf("\n");
|
|
RF_UNLOCK_MUTEX(rf_printf_mutex);
|
|
}
|
|
#endif
|