diff options
Diffstat (limited to 'sys/dev/raidframe/rf_stripelocks.c')
-rw-r--r-- | sys/dev/raidframe/rf_stripelocks.c | 667 |
1 files changed, 667 insertions, 0 deletions
diff --git a/sys/dev/raidframe/rf_stripelocks.c b/sys/dev/raidframe/rf_stripelocks.c new file mode 100644 index 0000000..bcee719 --- /dev/null +++ b/sys/dev/raidframe/rf_stripelocks.c @@ -0,0 +1,667 @@ +/* $FreeBSD$ */ +/* $NetBSD: rf_stripelocks.c,v 1.6 2000/12/04 11:35:46 fvdl Exp $ */ +/* + * Copyright (c) 1995 Carnegie-Mellon University. + * All rights reserved. + * + * Authors: Mark Holland, Jim Zelenka + * + * 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.c -- code to lock stripes for read and write access + * + * The code distinguishes between read locks and write locks. There can be + * as many readers to given stripe as desired. When a write request comes + * in, no further readers are allowed to enter, and all subsequent requests + * are queued in FIFO order. When a the number of readers goes to zero, the + * writer is given the lock. When a writer releases the lock, the list of + * queued requests is scanned, and all readersq up to the next writer are + * given the lock. + * + * The lock table size must be one less than a power of two, but HASH_STRIPEID + * is the only function that requires this. + * + * The code now supports "range locks". When you ask to lock a stripe, you + * specify a range of addresses in that stripe that you want to lock. When + * you acquire the lock, you've locked only this range of addresses, and + * other threads can concurrently read/write any non-overlapping portions + * of the stripe. The "addresses" that you lock are abstract in that you + * can pass in anything you like. The expectation is that you'll pass in + * the range of physical disk offsets of the parity bits you're planning + * to update. The idea behind this, of course, is to allow sub-stripe + * locking. The implementation is perhaps not the best imaginable; in the + * worst case a lock release is O(n^2) in the total number of outstanding + * requests to a given stripe. Note that if you're striping with a + * stripe unit size equal to an entire disk (i.e. not striping), there will + * be only one stripe and you may spend some significant number of cycles + * searching through stripe lock descriptors. + */ + +#include <dev/raidframe/rf_types.h> +#include <dev/raidframe/rf_raid.h> +#include <dev/raidframe/rf_stripelocks.h> +#include <dev/raidframe/rf_alloclist.h> +#include <dev/raidframe/rf_general.h> +#include <dev/raidframe/rf_freelist.h> +#include <dev/raidframe/rf_debugprint.h> +#include <dev/raidframe/rf_driver.h> +#include <dev/raidframe/rf_shutdown.h> + +#define Dprintf1(s,a) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL) +#define Dprintf2(s,a,b) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL) +#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) +#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) +#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) +#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) +#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) +#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)) + +#define FLUSH + +#define HASH_STRIPEID(_sid_) ( (_sid_) & (rf_lockTableSize-1) ) + +static void AddToWaitersQueue(RF_LockTableEntry_t * lockTable, RF_StripeLockDesc_t * lockDesc, RF_LockReqDesc_t * lockReqDesc); +static RF_StripeLockDesc_t *AllocStripeLockDesc(RF_StripeNum_t stripeID); +static void FreeStripeLockDesc(RF_StripeLockDesc_t * p); +static void PrintLockedStripes(RF_LockTableEntry_t * lockTable); + +/* determines if two ranges overlap. always yields false if either start value is negative */ +#define SINGLE_RANGE_OVERLAP(_strt1, _stop1, _strt2, _stop2) \ + ( (_strt1 >= 0) && (_strt2 >= 0) && (RF_MAX(_strt1, _strt2) <= RF_MIN(_stop1, _stop2)) ) + +/* determines if any of the ranges specified in the two lock descriptors overlap each other */ +#define RANGE_OVERLAP(_cand, _pred) \ + ( SINGLE_RANGE_OVERLAP((_cand)->start, (_cand)->stop, (_pred)->start, (_pred)->stop ) || \ + SINGLE_RANGE_OVERLAP((_cand)->start2, (_cand)->stop2, (_pred)->start, (_pred)->stop ) || \ + SINGLE_RANGE_OVERLAP((_cand)->start, (_cand)->stop, (_pred)->start2, (_pred)->stop2) || \ + SINGLE_RANGE_OVERLAP((_cand)->start2, (_cand)->stop2, (_pred)->start2, (_pred)->stop2) ) + +/* Determines if a candidate lock request conflicts with a predecessor lock req. + * Note that the arguments are not interchangeable. + * The rules are: + * a candidate read conflicts with a predecessor write if any ranges overlap + * a candidate write conflicts with a predecessor read if any ranges overlap + * a candidate write conflicts with a predecessor write if any ranges overlap + */ +#define STRIPELOCK_CONFLICT(_cand, _pred) \ + RANGE_OVERLAP((_cand), (_pred)) && \ + ( ( (((_cand)->type == RF_IO_TYPE_READ) && ((_pred)->type == RF_IO_TYPE_WRITE)) || \ + (((_cand)->type == RF_IO_TYPE_WRITE) && ((_pred)->type == RF_IO_TYPE_READ)) || \ + (((_cand)->type == RF_IO_TYPE_WRITE) && ((_pred)->type == RF_IO_TYPE_WRITE)) \ + ) \ + ) + +static RF_FreeList_t *rf_stripelock_freelist; +#define RF_MAX_FREE_STRIPELOCK 128 +#define RF_STRIPELOCK_INC 8 +#define RF_STRIPELOCK_INITIAL 32 + +static void rf_ShutdownStripeLockFreeList(void *); +static void rf_RaidShutdownStripeLocks(void *); + +static void +rf_ShutdownStripeLockFreeList(ignored) + void *ignored; +{ + RF_FREELIST_DESTROY(rf_stripelock_freelist, next, (RF_StripeLockDesc_t *)); +} + +int +rf_ConfigureStripeLockFreeList(listp) + RF_ShutdownList_t **listp; +{ + unsigned mask; + int rc; + + RF_FREELIST_CREATE(rf_stripelock_freelist, RF_MAX_FREE_STRIPELOCK, + RF_STRIPELOCK_INITIAL, sizeof(RF_StripeLockDesc_t)); + rc = rf_ShutdownCreate(listp, rf_ShutdownStripeLockFreeList, NULL); + if (rc) { + RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", + __FILE__, __LINE__, rc); + rf_ShutdownStripeLockFreeList(NULL); + return (rc); + } + RF_FREELIST_PRIME(rf_stripelock_freelist, RF_STRIPELOCK_INITIAL, next, + (RF_StripeLockDesc_t *)); + for (mask = 0x1; mask; mask <<= 1) + if (rf_lockTableSize == mask) + break; + if (!mask) { + printf("[WARNING: lock table size must be a power of two. Setting to %d.]\n", RF_DEFAULT_LOCK_TABLE_SIZE); + rf_lockTableSize = RF_DEFAULT_LOCK_TABLE_SIZE; + } + return (0); +} + +RF_LockTableEntry_t * +rf_MakeLockTable() +{ + RF_LockTableEntry_t *lockTable; + int i, rc; + + RF_Calloc(lockTable, ((int) rf_lockTableSize), sizeof(RF_LockTableEntry_t), (RF_LockTableEntry_t *)); + if (lockTable == NULL) + return (NULL); + for (i = 0; i < rf_lockTableSize; i++) { + rc = rf_mutex_init(&lockTable[i].mutex, __FUNCTION__); + if (rc) { + RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__, + __LINE__, rc); + /* XXX clean up other mutexes */ + return (NULL); + } + } + return (lockTable); +} + +void +rf_ShutdownStripeLocks(RF_LockTableEntry_t * lockTable) +{ + int i; + + if (rf_stripeLockDebug) { + PrintLockedStripes(lockTable); + } + for (i = 0; i < rf_lockTableSize; i++) { + rf_mutex_destroy(&lockTable[i].mutex); + } + RF_Free(lockTable, rf_lockTableSize * sizeof(RF_LockTableEntry_t)); +} + +static void +rf_RaidShutdownStripeLocks(arg) + void *arg; +{ + RF_Raid_t *raidPtr = (RF_Raid_t *) arg; + rf_ShutdownStripeLocks(raidPtr->lockTable); +} + +int +rf_ConfigureStripeLocks( + RF_ShutdownList_t ** listp, + RF_Raid_t * raidPtr, + RF_Config_t * cfgPtr) +{ + int rc; + + raidPtr->lockTable = rf_MakeLockTable(); + if (raidPtr->lockTable == NULL) + return (ENOMEM); + rc = rf_ShutdownCreate(listp, rf_RaidShutdownStripeLocks, raidPtr); + if (rc) { + RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", + __FILE__, __LINE__, rc); + rf_ShutdownStripeLocks(raidPtr->lockTable); + return (rc); + } + return (0); +} +/* returns 0 if you've got the lock, and non-zero if you have to wait. + * if and only if you have to wait, we'll cause cbFunc to get invoked + * with cbArg when you are granted the lock. We store a tag in *releaseTag + * that you need to give back to us when you release the lock. + */ +int +rf_AcquireStripeLock( + RF_LockTableEntry_t * lockTable, + RF_StripeNum_t stripeID, + RF_LockReqDesc_t * lockReqDesc) +{ + RF_StripeLockDesc_t *lockDesc; + RF_LockReqDesc_t *p; + int tid = 0, hashval = HASH_STRIPEID(stripeID); + int retcode = 0; + + RF_ASSERT(RF_IO_IS_R_OR_W(lockReqDesc->type)); + + if (rf_stripeLockDebug) { + if (stripeID == -1) + Dprintf1("[%d] Lock acquisition supressed (stripeID == -1)\n", tid); + else { + Dprintf8("[%d] Trying to acquire stripe lock table 0x%lx SID %ld type %c range %ld-%ld, range2 %ld-%ld hashval %d\n", + tid, (unsigned long) lockTable, stripeID, lockReqDesc->type, lockReqDesc->start, + lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2); + Dprintf3("[%d] lock %ld hashval %d\n", tid, stripeID, hashval); + FLUSH; + } + } + if (stripeID == -1) + return (0); + lockReqDesc->next = NULL; /* just to be sure */ + + RF_LOCK_MUTEX(lockTable[hashval].mutex); + for (lockDesc = lockTable[hashval].descList; lockDesc; lockDesc = lockDesc->next) { + if (lockDesc->stripeID == stripeID) + break; + } + + if (!lockDesc) { /* no entry in table => no one reading or + * writing */ + lockDesc = AllocStripeLockDesc(stripeID); + lockDesc->next = lockTable[hashval].descList; + lockTable[hashval].descList = lockDesc; + if (lockReqDesc->type == RF_IO_TYPE_WRITE) + lockDesc->nWriters++; + lockDesc->granted = lockReqDesc; + if (rf_stripeLockDebug) { + Dprintf7("[%d] no one waiting: lock %ld %c %ld-%ld %ld-%ld granted\n", + tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2); + FLUSH; + } + } else { + + if (lockReqDesc->type == RF_IO_TYPE_WRITE) + lockDesc->nWriters++; + + if (lockDesc->nWriters == 0) { /* no need to search any lists + * if there are no writers + * anywhere */ + lockReqDesc->next = lockDesc->granted; + lockDesc->granted = lockReqDesc; + if (rf_stripeLockDebug) { + Dprintf7("[%d] no writers: lock %ld %c %ld-%ld %ld-%ld granted\n", + tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2); + FLUSH; + } + } else { + + /* search the granted & waiting lists for a conflict. + * stop searching as soon as we find one */ + retcode = 0; + for (p = lockDesc->granted; p; p = p->next) + if (STRIPELOCK_CONFLICT(lockReqDesc, p)) { + retcode = 1; + break; + } + if (!retcode) + for (p = lockDesc->waitersH; p; p = p->next) + if (STRIPELOCK_CONFLICT(lockReqDesc, p)) { + retcode = 2; + break; + } + if (!retcode) { + lockReqDesc->next = lockDesc->granted; /* no conflicts found => + * grant lock */ + lockDesc->granted = lockReqDesc; + if (rf_stripeLockDebug) { + Dprintf7("[%d] no conflicts: lock %ld %c %ld-%ld %ld-%ld granted\n", + tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, + lockReqDesc->start2, lockReqDesc->stop2); + FLUSH; + } + } else { + if (rf_stripeLockDebug) { + Dprintf6("[%d] conflict: lock %ld %c %ld-%ld hashval=%d not granted\n", + tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, + hashval); + Dprintf3("[%d] lock %ld retcode=%d\n", tid, stripeID, retcode); + FLUSH; + } + AddToWaitersQueue(lockTable, lockDesc, lockReqDesc); /* conflict => the + * current access must + * wait */ + } + } + } + + RF_UNLOCK_MUTEX(lockTable[hashval].mutex); + return (retcode); +} + +void +rf_ReleaseStripeLock( + RF_LockTableEntry_t * lockTable, + RF_StripeNum_t stripeID, + RF_LockReqDesc_t * lockReqDesc) +{ + RF_StripeLockDesc_t *lockDesc, *ld_t; + RF_LockReqDesc_t *lr, *lr_t, *callbacklist, *t; + RF_IoType_t type = lockReqDesc->type; + int tid = 0, hashval = HASH_STRIPEID(stripeID); + int release_it, consider_it; + RF_LockReqDesc_t *candidate, *candidate_t, *predecessor; + + RF_ASSERT(RF_IO_IS_R_OR_W(type)); + + if (rf_stripeLockDebug) { + if (stripeID == -1) + Dprintf1("[%d] Lock release supressed (stripeID == -1)\n", tid); + else { + Dprintf8("[%d] Releasing stripe lock on stripe ID %ld, type %c range %ld-%ld %ld-%ld table 0x%lx\n", + tid, stripeID, lockReqDesc->type, lockReqDesc->start, lockReqDesc->stop, lockReqDesc->start2, lockReqDesc->stop2, lockTable); + FLUSH; + } + } + if (stripeID == -1) + return; + + RF_LOCK_MUTEX(lockTable[hashval].mutex); + + /* find the stripe lock descriptor */ + for (ld_t = NULL, lockDesc = lockTable[hashval].descList; lockDesc; ld_t = lockDesc, lockDesc = lockDesc->next) { + if (lockDesc->stripeID == stripeID) + break; + } + RF_ASSERT(lockDesc); /* major error to release a lock that doesn't + * exist */ + + /* find the stripe lock request descriptor & delete it from the list */ + for (lr_t = NULL, lr = lockDesc->granted; lr; lr_t = lr, lr = lr->next) + if (lr == lockReqDesc) + break; + + RF_ASSERT(lr && (lr == lockReqDesc)); /* major error to release a + * lock that hasn't been + * granted */ + if (lr_t) + lr_t->next = lr->next; + else { + RF_ASSERT(lr == lockDesc->granted); + lockDesc->granted = lr->next; + } + lr->next = NULL; + + if (lockReqDesc->type == RF_IO_TYPE_WRITE) + lockDesc->nWriters--; + + /* 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_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; + } + } + 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_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; + } + 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_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; + } + 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_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; + } + release_it = 0; + break; + } + } + + /* release it if indicated */ + if (release_it) { + 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; + } + 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_stripeLockDebug) { + Dprintf3("[%d] Last lock released (table 0x%lx): deleting desc for stripeID %ld\n", tid, (unsigned long) lockTable, stripeID); + FLUSH; + } + 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_LockTableEntry_t * lockTable, + RF_StripeLockDesc_t * lockDesc, + RF_LockReqDesc_t * lockReqDesc) +{ +#if 0 /* XXX fvdl -- unitialized use of 'tid' */ + int tid; + + if (rf_stripeLockDebug) { + Dprintf3("[%d] Waiting on lock for stripe %ld table 0x%lx\n", tid, lockDesc->stripeID, (unsigned long) lockTable); + FLUSH; + } +#endif + 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); +} + +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); +} |