/* $NetBSD: rf_diskqueue.c,v 1.1 1998/11/13 04:20:29 oster Exp $ */ /* * Copyright (c) 1995 Carnegie-Mellon University. * All rights reserved. * * Author: Mark Holland * * 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. */ /**************************************************************************************** * * rf_diskqueue.c -- higher-level disk queue code * * the routines here are a generic wrapper around the actual queueing * routines. The code here implements thread scheduling, synchronization, * and locking ops (see below) on top of the lower-level queueing code. * * to support atomic RMW, we implement "locking operations". When a locking op * is dispatched to the lower levels of the driver, the queue is locked, and no further * I/Os are dispatched until the queue receives & completes a corresponding "unlocking * operation". This code relies on the higher layers to guarantee that a locking * op will always be eventually followed by an unlocking op. The model is that * the higher layers are structured so locking and unlocking ops occur in pairs, i.e. * an unlocking op cannot be generated until after a locking op reports completion. * There is no good way to check to see that an unlocking op "corresponds" to the * op that currently has the queue locked, so we make no such attempt. Since by * definition there can be only one locking op outstanding on a disk, this should * not be a problem. * * In the kernel, we allow multiple I/Os to be concurrently dispatched to the disk * driver. In order to support locking ops in this environment, when we decide to * do a locking op, we stop dispatching new I/Os and wait until all dispatched I/Os * have completed before dispatching the locking op. * * Unfortunately, the code is different in the 3 different operating states * (user level, kernel, simulator). In the kernel, I/O is non-blocking, and * we have no disk threads to dispatch for us. Therefore, we have to dispatch * new I/Os to the scsi driver at the time of enqueue, and also at the time * of completion. At user level, I/O is blocking, and so only the disk threads * may dispatch I/Os. Thus at user level, all we can do at enqueue time is * enqueue and wake up the disk thread to do the dispatch. * ***************************************************************************************/ /* * : * * Log: rf_diskqueue.c,v * Revision 1.50 1996/08/07 21:08:38 jimz * b_proc -> kb_proc * * Revision 1.49 1996/07/05 20:36:14 jimz * make rf_ConfigureDiskQueueSystem return 0 * * Revision 1.48 1996/06/18 20:53:11 jimz * fix up disk queueing (remove configure routine, * add shutdown list arg to create routines) * * Revision 1.47 1996/06/14 14:16:36 jimz * fix handling of bogus queue type * * Revision 1.46 1996/06/13 20:41:44 jimz * add scan, cscan, random queueing * * Revision 1.45 1996/06/11 01:27:50 jimz * Fixed bug where diskthread shutdown would crash or hang. This * turned out to be two distinct bugs: * (1) [crash] The thread shutdown code wasn't properly waiting for * all the diskthreads to complete. This caused diskthreads that were * exiting+cleaning up to unlock a destroyed mutex. * (2) [hang] TerminateDiskQueues wasn't locking, and DiskIODequeue * only checked for termination _after_ a wakeup if the queues were * empty. This was a race where the termination wakeup could be lost * by the dequeueing thread, and the system would hang waiting for the * thread to exit, while the thread waited for an I/O or a signal to * check the termination flag. * * Revision 1.44 1996/06/10 11:55:47 jimz * Straightened out some per-array/not-per-array distinctions, fixed * a couple bugs related to confusion. Added shutdown lists. Removed * layout shutdown function (now subsumed by shutdown lists). * * Revision 1.43 1996/06/09 02:36:46 jimz * lots of little crufty cleanup- fixup whitespace * issues, comment #ifdefs, improve typing in some * places (esp size-related) * * Revision 1.42 1996/06/07 22:26:27 jimz * type-ify which_ru (RF_ReconUnitNum_t) * * Revision 1.41 1996/06/07 21:33:04 jimz * begin using consistent types for sector numbers, * stripe numbers, row+col numbers, recon unit numbers * * Revision 1.40 1996/06/06 17:28:04 jimz * track sector number of last I/O dequeued * * Revision 1.39 1996/06/06 01:14:13 jimz * fix crashing bug when tracerec is NULL (ie, from copyback) * initialize req->queue * * Revision 1.38 1996/06/05 19:38:32 jimz * fixed up disk queueing types config * added sstf disk queueing * fixed exit bug on diskthreads (ref-ing bad mem) * * Revision 1.37 1996/06/05 18:06:02 jimz * Major code cleanup. The Great Renaming is now done. * Better modularity. Better typing. Fixed a bunch of * synchronization bugs. Made a lot of global stuff * per-desc or per-array. Removed dead code. * * Revision 1.36 1996/05/30 23:22:16 jimz * bugfixes of serialization, timing problems * more cleanup * * Revision 1.35 1996/05/30 12:59:18 jimz * make etimer happier, more portable * * Revision 1.34 1996/05/30 11:29:41 jimz * Numerous bug fixes. Stripe lock release code disagreed with the taking code * about when stripes should be locked (I made it consistent: no parity, no lock) * There was a lot of extra serialization of I/Os which I've removed- a lot of * it was to calculate values for the cache code, which is no longer with us. * More types, function, macro cleanup. Added code to properly quiesce the array * on shutdown. Made a lot of stuff array-specific which was (bogusly) general * before. Fixed memory allocation, freeing bugs. * * Revision 1.33 1996/05/27 18:56:37 jimz * more code cleanup * better typing * compiles in all 3 environments * * Revision 1.32 1996/05/24 22:17:04 jimz * continue code + namespace cleanup * typed a bunch of flags * * Revision 1.31 1996/05/24 01:59:45 jimz * another checkpoint in code cleanup for release * time to sync kernel tree * * Revision 1.30 1996/05/23 21:46:35 jimz * checkpoint in code cleanup (release prep) * lots of types, function names have been fixed * * Revision 1.29 1996/05/23 00:33:23 jimz * code cleanup: move all debug decls to rf_options.c, all extern * debug decls to rf_options.h, all debug vars preceded by rf_ * * Revision 1.28 1996/05/20 16:14:29 jimz * switch to rf_{mutex,cond}_{init,destroy} * * Revision 1.27 1996/05/18 19:51:34 jimz * major code cleanup- fix syntax, make some types consistent, * add prototypes, clean out dead code, et cetera * * Revision 1.26 1996/05/16 19:21:49 wvcii * fixed typo in init_dqd * * Revision 1.25 1996/05/16 16:02:51 jimz * switch to RF_FREELIST stuff for DiskQueueData * * Revision 1.24 1996/05/10 16:24:14 jimz * new cvscan function names * * Revision 1.23 1996/05/01 16:27:54 jimz * don't use ccmn bp management * * Revision 1.22 1995/12/12 18:10:06 jimz * MIN -> RF_MIN, MAX -> RF_MAX, ASSERT -> RF_ASSERT * fix 80-column brain damage in comments * * Revision 1.21 1995/12/01 15:59:59 root * added copyright info * * Revision 1.20 1995/11/07 16:27:20 wvcii * added Peek() function to diskqueuesw * non-locking accesses are never blocked (assume clients enforce proper * respect for lock acquisition) * * Revision 1.19 1995/10/05 18:56:52 jimz * fix req handling in IOComplete * * Revision 1.18 1995/10/04 20:13:50 wvcii * added asserts to monitor numOutstanding queueLength * * Revision 1.17 1995/10/04 07:43:52 wvcii * queue->numOutstanding now valid for user & sim * added queue->queueLength * user tested & verified, sim untested * * Revision 1.16 1995/09/12 00:21:19 wvcii * added support for tracing disk queue time * */ #include "rf_types.h" #include "rf_threadstuff.h" #include "rf_threadid.h" #include "rf_raid.h" #include "rf_diskqueue.h" #include "rf_alloclist.h" #include "rf_acctrace.h" #include "rf_etimer.h" #include "rf_configure.h" #include "rf_general.h" #include "rf_freelist.h" #include "rf_debugprint.h" #include "rf_shutdown.h" #include "rf_cvscan.h" #include "rf_sstf.h" #include "rf_fifo.h" #ifdef SIMULATE #include "rf_diskevent.h" #endif /* SIMULATE */ #if !defined(__NetBSD__) extern struct buf *ubc_bufget(); #endif static int init_dqd(RF_DiskQueueData_t *); static void clean_dqd(RF_DiskQueueData_t *); static void rf_ShutdownDiskQueueSystem(void *); /* From rf_kintf.c */ int rf_DispatchKernelIO(RF_DiskQueue_t *,RF_DiskQueueData_t *); #define Dprintf1(s,a) if (rf_queueDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL) #define Dprintf2(s,a,b) if (rf_queueDebug) rf_debug_printf(s,(void *)((unsigned long)a),(void *)((unsigned long)b),NULL,NULL,NULL,NULL,NULL,NULL) #define Dprintf3(s,a,b,c) if (rf_queueDebug) 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) if (rf_queueDebug) 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) if (rf_queueDebug) 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) #if !defined(KERNEL) && !defined(SIMULATE) /* queue must be locked before invoking this */ #define SIGNAL_DISK_QUEUE(_q_,_wh_) \ { \ if ( (_q_)->numWaiting > 0) { \ (_q_)->numWaiting--; \ RF_SIGNAL_COND( ((_q_)->cond) ); \ } \ } /* queue must be locked before invoking this */ #define WAIT_DISK_QUEUE(_q_,_wh_) \ { \ (_q_)->numWaiting++; \ RF_WAIT_COND( ((_q_)->cond), ((_q_)->mutex) ); \ } #else /* !defined(KERNEL) && !defined(SIMULATE) */ #define SIGNAL_DISK_QUEUE(_q_,_wh_) #define WAIT_DISK_QUEUE(_q_,_wh_) #endif /* !defined(KERNEL) && !defined(SIMULATE) */ /***************************************************************************************** * * the disk queue switch defines all the functions used in the different queueing * disciplines * queue ID, init routine, enqueue routine, dequeue routine * ****************************************************************************************/ static RF_DiskQueueSW_t diskqueuesw[] = { {"fifo", /* FIFO */ rf_FifoCreate, rf_FifoEnqueue, rf_FifoDequeue, rf_FifoPeek, rf_FifoPromote}, {"cvscan", /* cvscan */ rf_CvscanCreate, rf_CvscanEnqueue, rf_CvscanDequeue, rf_CvscanPeek, rf_CvscanPromote }, {"sstf", /* shortest seek time first */ rf_SstfCreate, rf_SstfEnqueue, rf_SstfDequeue, rf_SstfPeek, rf_SstfPromote}, {"scan", /* SCAN (two-way elevator) */ rf_ScanCreate, rf_SstfEnqueue, rf_ScanDequeue, rf_ScanPeek, rf_SstfPromote}, {"cscan", /* CSCAN (one-way elevator) */ rf_CscanCreate, rf_SstfEnqueue, rf_CscanDequeue, rf_CscanPeek, rf_SstfPromote}, #if !defined(KERNEL) && RF_INCLUDE_QUEUE_RANDOM > 0 /* to make a point to Chris :-> */ {"random", /* random */ rf_FifoCreate, rf_FifoEnqueue, rf_RandomDequeue, rf_RandomPeek, rf_FifoPromote}, #endif /* !KERNEL && RF_INCLUDE_QUEUE_RANDOM > 0 */ }; #define NUM_DISK_QUEUE_TYPES (sizeof(diskqueuesw)/sizeof(RF_DiskQueueSW_t)) static RF_FreeList_t *rf_dqd_freelist; #define RF_MAX_FREE_DQD 256 #define RF_DQD_INC 16 #define RF_DQD_INITIAL 64 #ifdef __NetBSD__ #ifdef _KERNEL #include #endif #endif static int init_dqd(dqd) RF_DiskQueueData_t *dqd; { #ifdef KERNEL #ifdef __NetBSD__ /* XXX not sure if the following malloc is appropriate... probably not quite... */ dqd->bp = (struct buf *) malloc( sizeof(struct buf), M_DEVBUF, M_NOWAIT); memset(dqd->bp,0,sizeof(struct buf)); /* if you don't do it, nobody else will.. */ /* XXX */ /* printf("NEED TO IMPLEMENT THIS BETTER!\n"); */ #else dqd->bp = ubc_bufget(); #endif if (dqd->bp == NULL) { return(ENOMEM); } #endif /* KERNEL */ return(0); } static void clean_dqd(dqd) RF_DiskQueueData_t *dqd; { #ifdef KERNEL #ifdef __NetBSD__ /* printf("NEED TO IMPLEMENT THIS BETTER(2)!\n"); */ /* XXX ? */ free( dqd->bp, M_DEVBUF ); #else ubc_buffree(dqd->bp); #endif #endif /* KERNEL */ } /* configures a single disk queue */ static int config_disk_queue( RF_Raid_t *raidPtr, RF_DiskQueue_t *diskqueue, RF_RowCol_t r, /* row & col -- debug only. BZZT not any more... */ RF_RowCol_t c, RF_DiskQueueSW_t *p, RF_SectorCount_t sectPerDisk, dev_t dev, int maxOutstanding, RF_ShutdownList_t **listp, RF_AllocListElem_t *clList) { int rc; diskqueue->row = r; diskqueue->col = c; diskqueue->qPtr = p; diskqueue->qHdr = (p->Create)(sectPerDisk, clList, listp); diskqueue->dev = dev; diskqueue->numOutstanding = 0; diskqueue->queueLength = 0; diskqueue->maxOutstanding = maxOutstanding; diskqueue->curPriority = RF_IO_NORMAL_PRIORITY; diskqueue->nextLockingOp = NULL; diskqueue->unlockingOp = NULL; diskqueue->numWaiting=0; diskqueue->flags = 0; diskqueue->raidPtr = raidPtr; #if defined(__NetBSD__) && defined(_KERNEL) diskqueue->rf_cinfo = &raidPtr->raid_cinfo[r][c]; #endif rc = rf_create_managed_mutex(listp, &diskqueue->mutex); if (rc) { RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__, __LINE__, rc); return(rc); } rc = rf_create_managed_cond(listp, &diskqueue->cond); if (rc) { RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__, __LINE__, rc); return(rc); } return(0); } static void rf_ShutdownDiskQueueSystem(ignored) void *ignored; { RF_FREELIST_DESTROY_CLEAN(rf_dqd_freelist,next,(RF_DiskQueueData_t *),clean_dqd); } int rf_ConfigureDiskQueueSystem(listp) RF_ShutdownList_t **listp; { int rc; RF_FREELIST_CREATE(rf_dqd_freelist, RF_MAX_FREE_DQD, RF_DQD_INC, sizeof(RF_DiskQueueData_t)); if (rf_dqd_freelist == NULL) return(ENOMEM); rc = rf_ShutdownCreate(listp, rf_ShutdownDiskQueueSystem, NULL); if (rc) { RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n", __FILE__, __LINE__, rc); rf_ShutdownDiskQueueSystem(NULL); return(rc); } RF_FREELIST_PRIME_INIT(rf_dqd_freelist, RF_DQD_INITIAL,next, (RF_DiskQueueData_t *),init_dqd); return(0); } #ifndef KERNEL /* this is called prior to shutdown to wakeup everyone waiting on a disk queue * and tell them to exit */ void rf_TerminateDiskQueues(raidPtr) RF_Raid_t *raidPtr; { RF_RowCol_t r, c; raidPtr->terminate_disk_queues = 1; for (r=0; rnumRow; r++) { for (c=0; cnumCol + ((r==0) ? raidPtr->numSpare : 0); c++) { RF_LOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues"); RF_BROADCAST_COND(raidPtr->Queues[r][c].cond); RF_UNLOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues"); } } } #endif /* !KERNEL */ int rf_ConfigureDiskQueues( RF_ShutdownList_t **listp, RF_Raid_t *raidPtr, RF_Config_t *cfgPtr) { RF_DiskQueue_t **diskQueues, *spareQueues; RF_DiskQueueSW_t *p; RF_RowCol_t r, c; int rc, i; raidPtr->maxQueueDepth = cfgPtr->maxOutstandingDiskReqs; for(p=NULL,i=0;idiskQueueType)) { p = &diskqueuesw[i]; break; } } if (p == NULL) { RF_ERRORMSG2("Unknown queue type \"%s\". Using %s\n",cfgPtr->diskQueueType, diskqueuesw[0].queueType); p = &diskqueuesw[0]; } RF_CallocAndAdd(diskQueues, raidPtr->numRow, sizeof(RF_DiskQueue_t *), (RF_DiskQueue_t **), raidPtr->cleanupList); if (diskQueues == NULL) { return(ENOMEM); } raidPtr->Queues = diskQueues; for (r=0; rnumRow; r++) { RF_CallocAndAdd(diskQueues[r], raidPtr->numCol + ((r==0) ? raidPtr->numSpare : 0), sizeof(RF_DiskQueue_t), (RF_DiskQueue_t *), raidPtr->cleanupList); if (diskQueues[r] == NULL) return(ENOMEM); for (c=0; cnumCol; c++) { rc = config_disk_queue(raidPtr, &diskQueues[r][c], r, c, p, raidPtr->sectorsPerDisk, raidPtr->Disks[r][c].dev, cfgPtr->maxOutstandingDiskReqs, listp, raidPtr->cleanupList); if (rc) return(rc); } } spareQueues = &raidPtr->Queues[0][raidPtr->numCol]; for (r=0; rnumSpare; r++) { rc = config_disk_queue(raidPtr, &spareQueues[r], 0, raidPtr->numCol+r, p, raidPtr->sectorsPerDisk, raidPtr->Disks[0][raidPtr->numCol+r].dev, cfgPtr->maxOutstandingDiskReqs, listp, raidPtr->cleanupList); if (rc) return(rc); } return(0); } /* Enqueue a disk I/O * * Unfortunately, we have to do things differently in the different * environments (simulator, user-level, kernel). * At user level, all I/O is blocking, so we have 1 or more threads/disk * and the thread that enqueues is different from the thread that dequeues. * In the kernel, I/O is non-blocking and so we'd like to have multiple * I/Os outstanding on the physical disks when possible. * * when any request arrives at a queue, we have two choices: * dispatch it to the lower levels * queue it up * * kernel rules for when to do what: * locking request: queue empty => dispatch and lock queue, * else queue it * unlocking req : always dispatch it * normal req : queue empty => dispatch it & set priority * queue not full & priority is ok => dispatch it * else queue it * * user-level rules: * always enqueue. In the special case of an unlocking op, enqueue * in a special way that will cause the unlocking op to be the next * thing dequeued. * * simulator rules: * Do the same as at user level, with the sleeps and wakeups suppressed. */ void rf_DiskIOEnqueue(queue, req, pri) RF_DiskQueue_t *queue; RF_DiskQueueData_t *req; int pri; { int tid; RF_ETIMER_START(req->qtime); rf_get_threadid(tid); RF_ASSERT(req->type == RF_IO_TYPE_NOP || req->numSector); req->priority = pri; if (rf_queueDebug && (req->numSector == 0)) { printf("Warning: Enqueueing zero-sector access\n"); } #ifdef KERNEL /* * kernel */ RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" ); /* locking request */ if (RF_LOCKING_REQ(req)) { if (RF_QUEUE_EMPTY(queue)) { Dprintf3("Dispatching pri %d locking op to r %d c %d (queue empty)\n",pri,queue->row, queue->col); RF_LOCK_QUEUE(queue); rf_DispatchKernelIO(queue, req); } else { queue->queueLength++; /* increment count of number of requests waiting in this queue */ Dprintf3("Enqueueing pri %d locking op to r %d c %d (queue not empty)\n",pri,queue->row, queue->col); req->queue = (void *)queue; (queue->qPtr->Enqueue)(queue->qHdr, req, pri); } } /* unlocking request */ else if (RF_UNLOCKING_REQ(req)) { /* we'll do the actual unlock when this I/O completes */ Dprintf3("Dispatching pri %d unlocking op to r %d c %d\n",pri,queue->row, queue->col); RF_ASSERT(RF_QUEUE_LOCKED(queue)); rf_DispatchKernelIO(queue, req); } /* normal request */ else if (RF_OK_TO_DISPATCH(queue, req)) { Dprintf3("Dispatching pri %d regular op to r %d c %d (ok to dispatch)\n",pri,queue->row, queue->col); rf_DispatchKernelIO(queue, req); } else { queue->queueLength++; /* increment count of number of requests waiting in this queue */ Dprintf3("Enqueueing pri %d regular op to r %d c %d (not ok to dispatch)\n",pri,queue->row, queue->col); req->queue = (void *)queue; (queue->qPtr->Enqueue)(queue->qHdr, req, pri); } RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" ); #else /* KERNEL */ /* * user-level */ RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" ); queue->queueLength++; /* increment count of number of requests waiting in this queue */ /* unlocking request */ if (RF_UNLOCKING_REQ(req)) { Dprintf4("[%d] enqueueing pri %d unlocking op & signalling r %d c %d\n", tid, pri, queue->row, queue->col); RF_ASSERT(RF_QUEUE_LOCKED(queue) && queue->unlockingOp == NULL); queue->unlockingOp = req; } /* locking and normal requests */ else { req->queue = (void *)queue; Dprintf5("[%d] enqueueing pri %d %s op & signalling r %d c %d\n", tid, pri, (RF_LOCKING_REQ(req)) ? "locking" : "regular",queue->row,queue->col); (queue->qPtr->Enqueue)(queue->qHdr, req, pri); } SIGNAL_DISK_QUEUE( queue, "DiskIOEnqueue"); RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" ); #endif /* KERNEL */ } #if !defined(KERNEL) && !defined(SIMULATE) /* user-level only: tell all threads to wake up & recheck the queue */ void rf_BroadcastOnQueue(queue) RF_DiskQueue_t *queue; { int i; if (queue->maxOutstanding > 1) for (i=0; imaxOutstanding; i++) { SIGNAL_DISK_QUEUE(queue, "BroadcastOnQueue" ); } } #endif /* !KERNEL && !SIMULATE */ #ifndef KERNEL /* not used in kernel */ RF_DiskQueueData_t *rf_DiskIODequeue(queue) RF_DiskQueue_t *queue; { RF_DiskQueueData_t *p, *headItem; int tid; rf_get_threadid(tid); RF_LOCK_QUEUE_MUTEX( queue, "DiskIODequeue" ); for (p=NULL; !p; ) { if (queue->unlockingOp) { /* unlocking request */ RF_ASSERT(RF_QUEUE_LOCKED(queue)); p = queue->unlockingOp; queue->unlockingOp = NULL; Dprintf4("[%d] dequeueing pri %d unlocking op r %d c %d\n", tid, p->priority, queue->row,queue->col); } else { headItem = (queue->qPtr->Peek)(queue->qHdr); if (headItem) { if (RF_LOCKING_REQ(headItem)) { /* locking request */ if (!RF_QUEUE_LOCKED(queue)) { /* queue isn't locked, so dequeue the request & lock the queue */ p = (queue->qPtr->Dequeue)( queue->qHdr ); if (p) Dprintf4("[%d] dequeueing pri %d locking op r %d c %d\n", tid, p->priority, queue->row, queue->col); else Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col); } else { /* queue already locked, no dequeue occurs */ Dprintf3("[%d] no dequeue -- queue is locked r %d c %d\n", tid, queue->row, queue->col); p = NULL; } } else { /* normal request, always dequeue and assume caller already has lock (if needed) */ p = (queue->qPtr->Dequeue)( queue->qHdr ); if (p) Dprintf4("[%d] dequeueing pri %d regular op r %d c %d\n", tid, p->priority, queue->row, queue->col); else Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col); } } else { Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col); } } if (queue->raidPtr->terminate_disk_queues) { p = NULL; break; } #ifdef SIMULATE break; /* in simulator, return NULL on empty queue instead of blocking */ #else /* SIMULATE */ if (!p) { Dprintf3("[%d] nothing to dequeue: waiting r %d c %d\n", tid, queue->row, queue->col); WAIT_DISK_QUEUE( queue, "DiskIODequeue" ); } #endif /* SIMULATE */ } if (p) { queue->queueLength--; /* decrement count of number of requests waiting in this queue */ RF_ASSERT(queue->queueLength >= 0); queue->numOutstanding++; queue->last_deq_sector = p->sectorOffset; /* record the amount of time this request spent in the disk queue */ RF_ETIMER_STOP(p->qtime); RF_ETIMER_EVAL(p->qtime); if (p->tracerec) p->tracerec->diskqueue_us += RF_ETIMER_VAL_US(p->qtime); } if (p && RF_LOCKING_REQ(p)) { RF_ASSERT(!RF_QUEUE_LOCKED(queue)); Dprintf3("[%d] locking queue r %d c %d\n",tid,queue->row,queue->col); RF_LOCK_QUEUE(queue); } RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIODequeue" ); return(p); } #else /* !KERNEL */ /* get the next set of I/Os started, kernel version only */ void rf_DiskIOComplete(queue, req, status) RF_DiskQueue_t *queue; RF_DiskQueueData_t *req; int status; { int done=0; RF_LOCK_QUEUE_MUTEX( queue, "DiskIOComplete" ); /* unlock the queue: (1) after an unlocking req completes (2) after a locking req fails */ if (RF_UNLOCKING_REQ(req) || (RF_LOCKING_REQ(req) && status)) { Dprintf2("DiskIOComplete: unlocking queue at r %d c %d\n", queue->row, queue->col); RF_ASSERT(RF_QUEUE_LOCKED(queue) && (queue->unlockingOp == NULL)); RF_UNLOCK_QUEUE(queue); } queue->numOutstanding--; RF_ASSERT(queue->numOutstanding >= 0); /* dispatch requests to the disk until we find one that we can't. */ /* no reason to continue once we've filled up the queue */ /* no reason to even start if the queue is locked */ while (!done && !RF_QUEUE_FULL(queue) && !RF_QUEUE_LOCKED(queue)) { if (queue->nextLockingOp) { req = queue->nextLockingOp; queue->nextLockingOp = NULL; Dprintf3("DiskIOComplete: a pri %d locking req was pending at r %d c %d\n",req->priority,queue->row, queue->col); } else { req = (queue->qPtr->Dequeue)( queue->qHdr ); Dprintf3("DiskIOComplete: extracting pri %d req from queue at r %d c %d\n",req->priority,queue->row, queue->col); } if (req) { queue->queueLength--; /* decrement count of number of requests waiting in this queue */ RF_ASSERT(queue->queueLength >= 0); } if (!req) done=1; else if (RF_LOCKING_REQ(req)) { if (RF_QUEUE_EMPTY(queue)) { /* dispatch it */ Dprintf3("DiskIOComplete: dispatching pri %d locking req to r %d c %d (queue empty)\n",req->priority,queue->row, queue->col); RF_LOCK_QUEUE(queue); rf_DispatchKernelIO(queue, req); done = 1; } else { /* put it aside to wait for the queue to drain */ Dprintf3("DiskIOComplete: postponing pri %d locking req to r %d c %d\n",req->priority,queue->row, queue->col); RF_ASSERT(queue->nextLockingOp == NULL); queue->nextLockingOp = req; done = 1; } } else if (RF_UNLOCKING_REQ(req)) { /* should not happen: unlocking ops should not get queued */ RF_ASSERT(RF_QUEUE_LOCKED(queue)); /* support it anyway for the future */ Dprintf3("DiskIOComplete: dispatching pri %d unl req to r %d c %d (SHOULD NOT SEE THIS)\n",req->priority,queue->row, queue->col); rf_DispatchKernelIO(queue, req); done = 1; } else if (RF_OK_TO_DISPATCH(queue, req)) { Dprintf3("DiskIOComplete: dispatching pri %d regular req to r %d c %d (ok to dispatch)\n",req->priority,queue->row, queue->col); rf_DispatchKernelIO(queue, req); } else { /* we can't dispatch it, so just re-enqueue it. */ /* potential trouble here if disk queues batch reqs */ Dprintf3("DiskIOComplete: re-enqueueing pri %d regular req to r %d c %d\n",req->priority,queue->row, queue->col); queue->queueLength++; (queue->qPtr->Enqueue)(queue->qHdr, req, req->priority); done = 1; } } RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOComplete" ); } #endif /* !KERNEL */ /* promotes accesses tagged with the given parityStripeID from low priority * to normal priority. This promotion is optional, meaning that a queue * need not implement it. If there is no promotion routine associated with * a queue, this routine does nothing and returns -1. */ int rf_DiskIOPromote(queue, parityStripeID, which_ru) RF_DiskQueue_t *queue; RF_StripeNum_t parityStripeID; RF_ReconUnitNum_t which_ru; { int retval; if (!queue->qPtr->Promote) return(-1); RF_LOCK_QUEUE_MUTEX( queue, "DiskIOPromote" ); retval = (queue->qPtr->Promote)( queue->qHdr, parityStripeID, which_ru ); RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOPromote" ); return(retval); } RF_DiskQueueData_t *rf_CreateDiskQueueData( RF_IoType_t typ, RF_SectorNum_t ssect, RF_SectorCount_t nsect, caddr_t buf, RF_StripeNum_t parityStripeID, RF_ReconUnitNum_t which_ru, int (*wakeF)(void *,int), void *arg, RF_DiskQueueData_t *next, RF_AccTraceEntry_t *tracerec, void *raidPtr, RF_DiskQueueDataFlags_t flags, void *kb_proc) { RF_DiskQueueData_t *p; RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd); p->sectorOffset = ssect + rf_protectedSectors; p->numSector = nsect; p->type = typ; p->buf = buf; p->parityStripeID= parityStripeID; p->which_ru = which_ru; p->CompleteFunc = wakeF; p->argument = arg; p->next = next; p->tracerec = tracerec; p->priority = RF_IO_NORMAL_PRIORITY; p->AuxFunc = NULL; p->buf2 = NULL; #ifdef SIMULATE p->owner = rf_GetCurrentOwner(); #endif /* SIMULATE */ p->raidPtr = raidPtr; p->flags = flags; #ifdef KERNEL p->b_proc = kb_proc; #endif /* KERNEL */ return(p); } RF_DiskQueueData_t *rf_CreateDiskQueueDataFull( RF_IoType_t typ, RF_SectorNum_t ssect, RF_SectorCount_t nsect, caddr_t buf, RF_StripeNum_t parityStripeID, RF_ReconUnitNum_t which_ru, int (*wakeF)(void *,int), void *arg, RF_DiskQueueData_t *next, RF_AccTraceEntry_t *tracerec, int priority, int (*AuxFunc)(void *,...), caddr_t buf2, void *raidPtr, RF_DiskQueueDataFlags_t flags, void *kb_proc) { RF_DiskQueueData_t *p; RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd); p->sectorOffset = ssect + rf_protectedSectors; p->numSector = nsect; p->type = typ; p->buf = buf; p->parityStripeID= parityStripeID; p->which_ru = which_ru; p->CompleteFunc = wakeF; p->argument = arg; p->next = next; p->tracerec = tracerec; p->priority = priority; p->AuxFunc = AuxFunc; p->buf2 = buf2; #ifdef SIMULATE p->owner = rf_GetCurrentOwner(); #endif /* SIMULATE */ p->raidPtr = raidPtr; p->flags = flags; #ifdef KERNEL p->b_proc = kb_proc; #endif /* KERNEL */ return(p); } void rf_FreeDiskQueueData(p) RF_DiskQueueData_t *p; { RF_FREELIST_FREE_CLEAN(rf_dqd_freelist,p,next,clean_dqd); }