rf_diskqueue.c revision 1.3 1 /* $NetBSD: rf_diskqueue.c,v 1.3 1999/01/14 20:29:38 oster Exp $ */
2 /*
3 * Copyright (c) 1995 Carnegie-Mellon University.
4 * All rights reserved.
5 *
6 * Author: Mark Holland
7 *
8 * Permission to use, copy, modify and distribute this software and
9 * its documentation is hereby granted, provided that both the copyright
10 * notice and this permission notice appear in all copies of the
11 * software, derivative works or modified versions, and any portions
12 * thereof, and that both notices appear in supporting documentation.
13 *
14 * CARNEGIE MELLON ALLOWS FREE USE OF THIS SOFTWARE IN ITS "AS IS"
15 * CONDITION. CARNEGIE MELLON DISCLAIMS ANY LIABILITY OF ANY KIND
16 * FOR ANY DAMAGES WHATSOEVER RESULTING FROM THE USE OF THIS SOFTWARE.
17 *
18 * Carnegie Mellon requests users of this software to return to
19 *
20 * Software Distribution Coordinator or Software.Distribution (at) CS.CMU.EDU
21 * School of Computer Science
22 * Carnegie Mellon University
23 * Pittsburgh PA 15213-3890
24 *
25 * any improvements or extensions that they make and grant Carnegie the
26 * rights to redistribute these changes.
27 */
28
29 /****************************************************************************************
30 *
31 * rf_diskqueue.c -- higher-level disk queue code
32 *
33 * the routines here are a generic wrapper around the actual queueing
34 * routines. The code here implements thread scheduling, synchronization,
35 * and locking ops (see below) on top of the lower-level queueing code.
36 *
37 * to support atomic RMW, we implement "locking operations". When a locking op
38 * is dispatched to the lower levels of the driver, the queue is locked, and no further
39 * I/Os are dispatched until the queue receives & completes a corresponding "unlocking
40 * operation". This code relies on the higher layers to guarantee that a locking
41 * op will always be eventually followed by an unlocking op. The model is that
42 * the higher layers are structured so locking and unlocking ops occur in pairs, i.e.
43 * an unlocking op cannot be generated until after a locking op reports completion.
44 * There is no good way to check to see that an unlocking op "corresponds" to the
45 * op that currently has the queue locked, so we make no such attempt. Since by
46 * definition there can be only one locking op outstanding on a disk, this should
47 * not be a problem.
48 *
49 * In the kernel, we allow multiple I/Os to be concurrently dispatched to the disk
50 * driver. In order to support locking ops in this environment, when we decide to
51 * do a locking op, we stop dispatching new I/Os and wait until all dispatched I/Os
52 * have completed before dispatching the locking op.
53 *
54 * Unfortunately, the code is different in the 3 different operating states
55 * (user level, kernel, simulator). In the kernel, I/O is non-blocking, and
56 * we have no disk threads to dispatch for us. Therefore, we have to dispatch
57 * new I/Os to the scsi driver at the time of enqueue, and also at the time
58 * of completion. At user level, I/O is blocking, and so only the disk threads
59 * may dispatch I/Os. Thus at user level, all we can do at enqueue time is
60 * enqueue and wake up the disk thread to do the dispatch.
61 *
62 ***************************************************************************************/
63
64 /*
65 * :
66 *
67 * Log: rf_diskqueue.c,v
68 * Revision 1.50 1996/08/07 21:08:38 jimz
69 * b_proc -> kb_proc
70 *
71 * Revision 1.49 1996/07/05 20:36:14 jimz
72 * make rf_ConfigureDiskQueueSystem return 0
73 *
74 * Revision 1.48 1996/06/18 20:53:11 jimz
75 * fix up disk queueing (remove configure routine,
76 * add shutdown list arg to create routines)
77 *
78 * Revision 1.47 1996/06/14 14:16:36 jimz
79 * fix handling of bogus queue type
80 *
81 * Revision 1.46 1996/06/13 20:41:44 jimz
82 * add scan, cscan, random queueing
83 *
84 * Revision 1.45 1996/06/11 01:27:50 jimz
85 * Fixed bug where diskthread shutdown would crash or hang. This
86 * turned out to be two distinct bugs:
87 * (1) [crash] The thread shutdown code wasn't properly waiting for
88 * all the diskthreads to complete. This caused diskthreads that were
89 * exiting+cleaning up to unlock a destroyed mutex.
90 * (2) [hang] TerminateDiskQueues wasn't locking, and DiskIODequeue
91 * only checked for termination _after_ a wakeup if the queues were
92 * empty. This was a race where the termination wakeup could be lost
93 * by the dequeueing thread, and the system would hang waiting for the
94 * thread to exit, while the thread waited for an I/O or a signal to
95 * check the termination flag.
96 *
97 * Revision 1.44 1996/06/10 11:55:47 jimz
98 * Straightened out some per-array/not-per-array distinctions, fixed
99 * a couple bugs related to confusion. Added shutdown lists. Removed
100 * layout shutdown function (now subsumed by shutdown lists).
101 *
102 * Revision 1.43 1996/06/09 02:36:46 jimz
103 * lots of little crufty cleanup- fixup whitespace
104 * issues, comment #ifdefs, improve typing in some
105 * places (esp size-related)
106 *
107 * Revision 1.42 1996/06/07 22:26:27 jimz
108 * type-ify which_ru (RF_ReconUnitNum_t)
109 *
110 * Revision 1.41 1996/06/07 21:33:04 jimz
111 * begin using consistent types for sector numbers,
112 * stripe numbers, row+col numbers, recon unit numbers
113 *
114 * Revision 1.40 1996/06/06 17:28:04 jimz
115 * track sector number of last I/O dequeued
116 *
117 * Revision 1.39 1996/06/06 01:14:13 jimz
118 * fix crashing bug when tracerec is NULL (ie, from copyback)
119 * initialize req->queue
120 *
121 * Revision 1.38 1996/06/05 19:38:32 jimz
122 * fixed up disk queueing types config
123 * added sstf disk queueing
124 * fixed exit bug on diskthreads (ref-ing bad mem)
125 *
126 * Revision 1.37 1996/06/05 18:06:02 jimz
127 * Major code cleanup. The Great Renaming is now done.
128 * Better modularity. Better typing. Fixed a bunch of
129 * synchronization bugs. Made a lot of global stuff
130 * per-desc or per-array. Removed dead code.
131 *
132 * Revision 1.36 1996/05/30 23:22:16 jimz
133 * bugfixes of serialization, timing problems
134 * more cleanup
135 *
136 * Revision 1.35 1996/05/30 12:59:18 jimz
137 * make etimer happier, more portable
138 *
139 * Revision 1.34 1996/05/30 11:29:41 jimz
140 * Numerous bug fixes. Stripe lock release code disagreed with the taking code
141 * about when stripes should be locked (I made it consistent: no parity, no lock)
142 * There was a lot of extra serialization of I/Os which I've removed- a lot of
143 * it was to calculate values for the cache code, which is no longer with us.
144 * More types, function, macro cleanup. Added code to properly quiesce the array
145 * on shutdown. Made a lot of stuff array-specific which was (bogusly) general
146 * before. Fixed memory allocation, freeing bugs.
147 *
148 * Revision 1.33 1996/05/27 18:56:37 jimz
149 * more code cleanup
150 * better typing
151 * compiles in all 3 environments
152 *
153 * Revision 1.32 1996/05/24 22:17:04 jimz
154 * continue code + namespace cleanup
155 * typed a bunch of flags
156 *
157 * Revision 1.31 1996/05/24 01:59:45 jimz
158 * another checkpoint in code cleanup for release
159 * time to sync kernel tree
160 *
161 * Revision 1.30 1996/05/23 21:46:35 jimz
162 * checkpoint in code cleanup (release prep)
163 * lots of types, function names have been fixed
164 *
165 * Revision 1.29 1996/05/23 00:33:23 jimz
166 * code cleanup: move all debug decls to rf_options.c, all extern
167 * debug decls to rf_options.h, all debug vars preceded by rf_
168 *
169 * Revision 1.28 1996/05/20 16:14:29 jimz
170 * switch to rf_{mutex,cond}_{init,destroy}
171 *
172 * Revision 1.27 1996/05/18 19:51:34 jimz
173 * major code cleanup- fix syntax, make some types consistent,
174 * add prototypes, clean out dead code, et cetera
175 *
176 * Revision 1.26 1996/05/16 19:21:49 wvcii
177 * fixed typo in init_dqd
178 *
179 * Revision 1.25 1996/05/16 16:02:51 jimz
180 * switch to RF_FREELIST stuff for DiskQueueData
181 *
182 * Revision 1.24 1996/05/10 16:24:14 jimz
183 * new cvscan function names
184 *
185 * Revision 1.23 1996/05/01 16:27:54 jimz
186 * don't use ccmn bp management
187 *
188 * Revision 1.22 1995/12/12 18:10:06 jimz
189 * MIN -> RF_MIN, MAX -> RF_MAX, ASSERT -> RF_ASSERT
190 * fix 80-column brain damage in comments
191 *
192 * Revision 1.21 1995/12/01 15:59:59 root
193 * added copyright info
194 *
195 * Revision 1.20 1995/11/07 16:27:20 wvcii
196 * added Peek() function to diskqueuesw
197 * non-locking accesses are never blocked (assume clients enforce proper
198 * respect for lock acquisition)
199 *
200 * Revision 1.19 1995/10/05 18:56:52 jimz
201 * fix req handling in IOComplete
202 *
203 * Revision 1.18 1995/10/04 20:13:50 wvcii
204 * added asserts to monitor numOutstanding queueLength
205 *
206 * Revision 1.17 1995/10/04 07:43:52 wvcii
207 * queue->numOutstanding now valid for user & sim
208 * added queue->queueLength
209 * user tested & verified, sim untested
210 *
211 * Revision 1.16 1995/09/12 00:21:19 wvcii
212 * added support for tracing disk queue time
213 *
214 */
215
216 #include "rf_types.h"
217 #include "rf_threadstuff.h"
218 #include "rf_threadid.h"
219 #include "rf_raid.h"
220 #include "rf_diskqueue.h"
221 #include "rf_alloclist.h"
222 #include "rf_acctrace.h"
223 #include "rf_etimer.h"
224 #include "rf_configure.h"
225 #include "rf_general.h"
226 #include "rf_freelist.h"
227 #include "rf_debugprint.h"
228 #include "rf_shutdown.h"
229 #include "rf_cvscan.h"
230 #include "rf_sstf.h"
231 #include "rf_fifo.h"
232
233 #ifdef SIMULATE
234 #include "rf_diskevent.h"
235 #endif /* SIMULATE */
236
237 #if !defined(__NetBSD__)
238 extern struct buf *ubc_bufget();
239 #endif
240
241 static int init_dqd(RF_DiskQueueData_t *);
242 static void clean_dqd(RF_DiskQueueData_t *);
243 static void rf_ShutdownDiskQueueSystem(void *);
244 /* From rf_kintf.c */
245 int rf_DispatchKernelIO(RF_DiskQueue_t *,RF_DiskQueueData_t *);
246
247
248 #define Dprintf1(s,a) if (rf_queueDebug) rf_debug_printf(s,(void *)((unsigned long)a),NULL,NULL,NULL,NULL,NULL,NULL,NULL)
249 #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)
250 #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)
251 #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)
252 #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)
253
254 #if !defined(KERNEL) && !defined(SIMULATE)
255
256 /* queue must be locked before invoking this */
257 #define SIGNAL_DISK_QUEUE(_q_,_wh_) \
258 { \
259 if ( (_q_)->numWaiting > 0) { \
260 (_q_)->numWaiting--; \
261 RF_SIGNAL_COND( ((_q_)->cond) ); \
262 } \
263 }
264
265 /* queue must be locked before invoking this */
266 #define WAIT_DISK_QUEUE(_q_,_wh_) \
267 { \
268 (_q_)->numWaiting++; \
269 RF_WAIT_COND( ((_q_)->cond), ((_q_)->mutex) ); \
270 }
271
272 #else /* !defined(KERNEL) && !defined(SIMULATE) */
273
274 #define SIGNAL_DISK_QUEUE(_q_,_wh_)
275 #define WAIT_DISK_QUEUE(_q_,_wh_)
276
277 #endif /* !defined(KERNEL) && !defined(SIMULATE) */
278
279 /*****************************************************************************************
280 *
281 * the disk queue switch defines all the functions used in the different queueing
282 * disciplines
283 * queue ID, init routine, enqueue routine, dequeue routine
284 *
285 ****************************************************************************************/
286
287 static RF_DiskQueueSW_t diskqueuesw[] = {
288 {"fifo", /* FIFO */
289 rf_FifoCreate,
290 rf_FifoEnqueue,
291 rf_FifoDequeue,
292 rf_FifoPeek,
293 rf_FifoPromote},
294
295 {"cvscan", /* cvscan */
296 rf_CvscanCreate,
297 rf_CvscanEnqueue,
298 rf_CvscanDequeue,
299 rf_CvscanPeek,
300 rf_CvscanPromote },
301
302 {"sstf", /* shortest seek time first */
303 rf_SstfCreate,
304 rf_SstfEnqueue,
305 rf_SstfDequeue,
306 rf_SstfPeek,
307 rf_SstfPromote},
308
309 {"scan", /* SCAN (two-way elevator) */
310 rf_ScanCreate,
311 rf_SstfEnqueue,
312 rf_ScanDequeue,
313 rf_ScanPeek,
314 rf_SstfPromote},
315
316 {"cscan", /* CSCAN (one-way elevator) */
317 rf_CscanCreate,
318 rf_SstfEnqueue,
319 rf_CscanDequeue,
320 rf_CscanPeek,
321 rf_SstfPromote},
322
323 #if !defined(KERNEL) && RF_INCLUDE_QUEUE_RANDOM > 0
324 /* to make a point to Chris :-> */
325 {"random", /* random */
326 rf_FifoCreate,
327 rf_FifoEnqueue,
328 rf_RandomDequeue,
329 rf_RandomPeek,
330 rf_FifoPromote},
331 #endif /* !KERNEL && RF_INCLUDE_QUEUE_RANDOM > 0 */
332 };
333 #define NUM_DISK_QUEUE_TYPES (sizeof(diskqueuesw)/sizeof(RF_DiskQueueSW_t))
334
335 static RF_FreeList_t *rf_dqd_freelist;
336
337 #define RF_MAX_FREE_DQD 256
338 #define RF_DQD_INC 16
339 #define RF_DQD_INITIAL 64
340
341 #ifdef __NetBSD__
342 #ifdef _KERNEL
343 #include <sys/buf.h>
344 #endif
345 #endif
346
347 static int init_dqd(dqd)
348 RF_DiskQueueData_t *dqd;
349 {
350 #ifdef KERNEL
351 #ifdef __NetBSD__
352 /* XXX not sure if the following malloc is appropriate... probably not quite... */
353 dqd->bp = (struct buf *) malloc( sizeof(struct buf), M_DEVBUF, M_NOWAIT);
354 /* XXX */
355 /* printf("NEED TO IMPLEMENT THIS BETTER!\n"); */
356 #else
357 dqd->bp = ubc_bufget();
358 #endif
359 if (dqd->bp == NULL) {
360 return(ENOMEM);
361 }
362 #ifdef __NetBSD__
363 memset(dqd->bp,0,sizeof(struct buf)); /* if you don't do it, nobody else will.. */
364 #endif
365 #endif /* KERNEL */
366 return(0);
367 }
368
369 static void clean_dqd(dqd)
370 RF_DiskQueueData_t *dqd;
371 {
372 #ifdef KERNEL
373 #ifdef __NetBSD__
374 /* printf("NEED TO IMPLEMENT THIS BETTER(2)!\n"); */
375 /* XXX ? */
376 free( dqd->bp, M_DEVBUF );
377 #else
378 ubc_buffree(dqd->bp);
379 #endif
380
381 #endif /* KERNEL */
382 }
383
384 /* configures a single disk queue */
385 static int config_disk_queue(
386 RF_Raid_t *raidPtr,
387 RF_DiskQueue_t *diskqueue,
388 RF_RowCol_t r, /* row & col -- debug only. BZZT not any more... */
389 RF_RowCol_t c,
390 RF_DiskQueueSW_t *p,
391 RF_SectorCount_t sectPerDisk,
392 dev_t dev,
393 int maxOutstanding,
394 RF_ShutdownList_t **listp,
395 RF_AllocListElem_t *clList)
396 {
397 int rc;
398
399 diskqueue->row = r;
400 diskqueue->col = c;
401 diskqueue->qPtr = p;
402 diskqueue->qHdr = (p->Create)(sectPerDisk, clList, listp);
403 diskqueue->dev = dev;
404 diskqueue->numOutstanding = 0;
405 diskqueue->queueLength = 0;
406 diskqueue->maxOutstanding = maxOutstanding;
407 diskqueue->curPriority = RF_IO_NORMAL_PRIORITY;
408 diskqueue->nextLockingOp = NULL;
409 diskqueue->unlockingOp = NULL;
410 diskqueue->numWaiting=0;
411 diskqueue->flags = 0;
412 diskqueue->raidPtr = raidPtr;
413 #if defined(__NetBSD__) && defined(_KERNEL)
414 diskqueue->rf_cinfo = &raidPtr->raid_cinfo[r][c];
415 #endif
416 rc = rf_create_managed_mutex(listp, &diskqueue->mutex);
417 if (rc) {
418 RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
419 __LINE__, rc);
420 return(rc);
421 }
422 rc = rf_create_managed_cond(listp, &diskqueue->cond);
423 if (rc) {
424 RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__,
425 __LINE__, rc);
426 return(rc);
427 }
428 return(0);
429 }
430
431 static void rf_ShutdownDiskQueueSystem(ignored)
432 void *ignored;
433 {
434 RF_FREELIST_DESTROY_CLEAN(rf_dqd_freelist,next,(RF_DiskQueueData_t *),clean_dqd);
435 }
436
437 int rf_ConfigureDiskQueueSystem(listp)
438 RF_ShutdownList_t **listp;
439 {
440 int rc;
441
442 RF_FREELIST_CREATE(rf_dqd_freelist, RF_MAX_FREE_DQD,
443 RF_DQD_INC, sizeof(RF_DiskQueueData_t));
444 if (rf_dqd_freelist == NULL)
445 return(ENOMEM);
446 rc = rf_ShutdownCreate(listp, rf_ShutdownDiskQueueSystem, NULL);
447 if (rc) {
448 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
449 __FILE__, __LINE__, rc);
450 rf_ShutdownDiskQueueSystem(NULL);
451 return(rc);
452 }
453 RF_FREELIST_PRIME_INIT(rf_dqd_freelist, RF_DQD_INITIAL,next,
454 (RF_DiskQueueData_t *),init_dqd);
455 return(0);
456 }
457
458 #ifndef KERNEL
459 /* this is called prior to shutdown to wakeup everyone waiting on a disk queue
460 * and tell them to exit
461 */
462 void rf_TerminateDiskQueues(raidPtr)
463 RF_Raid_t *raidPtr;
464 {
465 RF_RowCol_t r, c;
466
467 raidPtr->terminate_disk_queues = 1;
468 for (r=0; r<raidPtr->numRow; r++) {
469 for (c=0; c<raidPtr->numCol + ((r==0) ? raidPtr->numSpare : 0); c++) {
470 RF_LOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues");
471 RF_BROADCAST_COND(raidPtr->Queues[r][c].cond);
472 RF_UNLOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues");
473 }
474 }
475 }
476 #endif /* !KERNEL */
477
478 int rf_ConfigureDiskQueues(
479 RF_ShutdownList_t **listp,
480 RF_Raid_t *raidPtr,
481 RF_Config_t *cfgPtr)
482 {
483 RF_DiskQueue_t **diskQueues, *spareQueues;
484 RF_DiskQueueSW_t *p;
485 RF_RowCol_t r, c;
486 int rc, i;
487
488 raidPtr->maxQueueDepth = cfgPtr->maxOutstandingDiskReqs;
489
490 for(p=NULL,i=0;i<NUM_DISK_QUEUE_TYPES;i++) {
491 if (!strcmp(diskqueuesw[i].queueType, cfgPtr->diskQueueType)) {
492 p = &diskqueuesw[i];
493 break;
494 }
495 }
496 if (p == NULL) {
497 RF_ERRORMSG2("Unknown queue type \"%s\". Using %s\n",cfgPtr->diskQueueType, diskqueuesw[0].queueType);
498 p = &diskqueuesw[0];
499 }
500
501 RF_CallocAndAdd(diskQueues, raidPtr->numRow, sizeof(RF_DiskQueue_t *), (RF_DiskQueue_t **), raidPtr->cleanupList);
502 if (diskQueues == NULL) {
503 return(ENOMEM);
504 }
505 raidPtr->Queues = diskQueues;
506 for (r=0; r<raidPtr->numRow; r++) {
507 RF_CallocAndAdd(diskQueues[r], raidPtr->numCol + ((r==0) ? raidPtr->numSpare : 0), sizeof(RF_DiskQueue_t), (RF_DiskQueue_t *), raidPtr->cleanupList);
508 if (diskQueues[r] == NULL)
509 return(ENOMEM);
510 for (c=0; c<raidPtr->numCol; c++) {
511 rc = config_disk_queue(raidPtr, &diskQueues[r][c], r, c, p,
512 raidPtr->sectorsPerDisk, raidPtr->Disks[r][c].dev,
513 cfgPtr->maxOutstandingDiskReqs, listp, raidPtr->cleanupList);
514 if (rc)
515 return(rc);
516 }
517 }
518
519 spareQueues = &raidPtr->Queues[0][raidPtr->numCol];
520 for (r=0; r<raidPtr->numSpare; r++) {
521 rc = config_disk_queue(raidPtr, &spareQueues[r],
522 0, raidPtr->numCol+r, p,
523 raidPtr->sectorsPerDisk,
524 raidPtr->Disks[0][raidPtr->numCol+r].dev,
525 cfgPtr->maxOutstandingDiskReqs, listp,
526 raidPtr->cleanupList);
527 if (rc)
528 return(rc);
529 }
530 return(0);
531 }
532
533 /* Enqueue a disk I/O
534 *
535 * Unfortunately, we have to do things differently in the different
536 * environments (simulator, user-level, kernel).
537 * At user level, all I/O is blocking, so we have 1 or more threads/disk
538 * and the thread that enqueues is different from the thread that dequeues.
539 * In the kernel, I/O is non-blocking and so we'd like to have multiple
540 * I/Os outstanding on the physical disks when possible.
541 *
542 * when any request arrives at a queue, we have two choices:
543 * dispatch it to the lower levels
544 * queue it up
545 *
546 * kernel rules for when to do what:
547 * locking request: queue empty => dispatch and lock queue,
548 * else queue it
549 * unlocking req : always dispatch it
550 * normal req : queue empty => dispatch it & set priority
551 * queue not full & priority is ok => dispatch it
552 * else queue it
553 *
554 * user-level rules:
555 * always enqueue. In the special case of an unlocking op, enqueue
556 * in a special way that will cause the unlocking op to be the next
557 * thing dequeued.
558 *
559 * simulator rules:
560 * Do the same as at user level, with the sleeps and wakeups suppressed.
561 */
562 void rf_DiskIOEnqueue(queue, req, pri)
563 RF_DiskQueue_t *queue;
564 RF_DiskQueueData_t *req;
565 int pri;
566 {
567 int tid;
568
569 RF_ETIMER_START(req->qtime);
570 rf_get_threadid(tid);
571 RF_ASSERT(req->type == RF_IO_TYPE_NOP || req->numSector);
572 req->priority = pri;
573
574 if (rf_queueDebug && (req->numSector == 0)) {
575 printf("Warning: Enqueueing zero-sector access\n");
576 }
577
578 #ifdef KERNEL
579 /*
580 * kernel
581 */
582 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
583 /* locking request */
584 if (RF_LOCKING_REQ(req)) {
585 if (RF_QUEUE_EMPTY(queue)) {
586 Dprintf3("Dispatching pri %d locking op to r %d c %d (queue empty)\n",pri,queue->row, queue->col);
587 RF_LOCK_QUEUE(queue);
588 rf_DispatchKernelIO(queue, req);
589 } else {
590 queue->queueLength++; /* increment count of number of requests waiting in this queue */
591 Dprintf3("Enqueueing pri %d locking op to r %d c %d (queue not empty)\n",pri,queue->row, queue->col);
592 req->queue = (void *)queue;
593 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
594 }
595 }
596 /* unlocking request */
597 else if (RF_UNLOCKING_REQ(req)) { /* we'll do the actual unlock when this I/O completes */
598 Dprintf3("Dispatching pri %d unlocking op to r %d c %d\n",pri,queue->row, queue->col);
599 RF_ASSERT(RF_QUEUE_LOCKED(queue));
600 rf_DispatchKernelIO(queue, req);
601 }
602 /* normal request */
603 else if (RF_OK_TO_DISPATCH(queue, req)) {
604 Dprintf3("Dispatching pri %d regular op to r %d c %d (ok to dispatch)\n",pri,queue->row, queue->col);
605 rf_DispatchKernelIO(queue, req);
606 } else {
607 queue->queueLength++; /* increment count of number of requests waiting in this queue */
608 Dprintf3("Enqueueing pri %d regular op to r %d c %d (not ok to dispatch)\n",pri,queue->row, queue->col);
609 req->queue = (void *)queue;
610 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
611 }
612 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
613
614 #else /* KERNEL */
615 /*
616 * user-level
617 */
618 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
619 queue->queueLength++; /* increment count of number of requests waiting in this queue */
620 /* unlocking request */
621 if (RF_UNLOCKING_REQ(req)) {
622 Dprintf4("[%d] enqueueing pri %d unlocking op & signalling r %d c %d\n", tid, pri, queue->row, queue->col);
623 RF_ASSERT(RF_QUEUE_LOCKED(queue) && queue->unlockingOp == NULL);
624 queue->unlockingOp = req;
625 }
626 /* locking and normal requests */
627 else {
628 req->queue = (void *)queue;
629 Dprintf5("[%d] enqueueing pri %d %s op & signalling r %d c %d\n", tid, pri,
630 (RF_LOCKING_REQ(req)) ? "locking" : "regular",queue->row,queue->col);
631 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
632 }
633 SIGNAL_DISK_QUEUE( queue, "DiskIOEnqueue");
634 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
635 #endif /* KERNEL */
636 }
637
638 #if !defined(KERNEL) && !defined(SIMULATE)
639 /* user-level only: tell all threads to wake up & recheck the queue */
640 void rf_BroadcastOnQueue(queue)
641 RF_DiskQueue_t *queue;
642 {
643 int i;
644
645 if (queue->maxOutstanding > 1) for (i=0; i<queue->maxOutstanding; i++) {
646 SIGNAL_DISK_QUEUE(queue, "BroadcastOnQueue" );
647 }
648 }
649 #endif /* !KERNEL && !SIMULATE */
650
651 #ifndef KERNEL /* not used in kernel */
652
653 RF_DiskQueueData_t *rf_DiskIODequeue(queue)
654 RF_DiskQueue_t *queue;
655 {
656 RF_DiskQueueData_t *p, *headItem;
657 int tid;
658
659 rf_get_threadid(tid);
660 RF_LOCK_QUEUE_MUTEX( queue, "DiskIODequeue" );
661 for (p=NULL; !p; ) {
662 if (queue->unlockingOp) {
663 /* unlocking request */
664 RF_ASSERT(RF_QUEUE_LOCKED(queue));
665 p = queue->unlockingOp;
666 queue->unlockingOp = NULL;
667 Dprintf4("[%d] dequeueing pri %d unlocking op r %d c %d\n", tid, p->priority, queue->row,queue->col);
668 }
669 else {
670 headItem = (queue->qPtr->Peek)(queue->qHdr);
671 if (headItem) {
672 if (RF_LOCKING_REQ(headItem)) {
673 /* locking request */
674 if (!RF_QUEUE_LOCKED(queue)) {
675 /* queue isn't locked, so dequeue the request & lock the queue */
676 p = (queue->qPtr->Dequeue)( queue->qHdr );
677 if (p)
678 Dprintf4("[%d] dequeueing pri %d locking op r %d c %d\n", tid, p->priority, queue->row, queue->col);
679 else
680 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
681 }
682 else {
683 /* queue already locked, no dequeue occurs */
684 Dprintf3("[%d] no dequeue -- queue is locked r %d c %d\n", tid, queue->row, queue->col);
685 p = NULL;
686 }
687 }
688 else {
689 /* normal request, always dequeue and assume caller already has lock (if needed) */
690 p = (queue->qPtr->Dequeue)( queue->qHdr );
691 if (p)
692 Dprintf4("[%d] dequeueing pri %d regular op r %d c %d\n", tid, p->priority, queue->row, queue->col);
693 else
694 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
695 }
696 }
697 else {
698 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
699 }
700 }
701
702 if (queue->raidPtr->terminate_disk_queues) {
703 p = NULL;
704 break;
705 }
706 #ifdef SIMULATE
707 break; /* in simulator, return NULL on empty queue instead of blocking */
708 #else /* SIMULATE */
709 if (!p) {
710 Dprintf3("[%d] nothing to dequeue: waiting r %d c %d\n", tid, queue->row, queue->col);
711 WAIT_DISK_QUEUE( queue, "DiskIODequeue" );
712 }
713 #endif /* SIMULATE */
714 }
715
716 if (p) {
717 queue->queueLength--; /* decrement count of number of requests waiting in this queue */
718 RF_ASSERT(queue->queueLength >= 0);
719 queue->numOutstanding++;
720 queue->last_deq_sector = p->sectorOffset;
721 /* record the amount of time this request spent in the disk queue */
722 RF_ETIMER_STOP(p->qtime);
723 RF_ETIMER_EVAL(p->qtime);
724 if (p->tracerec)
725 p->tracerec->diskqueue_us += RF_ETIMER_VAL_US(p->qtime);
726 }
727
728 if (p && RF_LOCKING_REQ(p)) {
729 RF_ASSERT(!RF_QUEUE_LOCKED(queue));
730 Dprintf3("[%d] locking queue r %d c %d\n",tid,queue->row,queue->col);
731 RF_LOCK_QUEUE(queue);
732 }
733 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIODequeue" );
734
735 return(p);
736 }
737
738 #else /* !KERNEL */
739
740 /* get the next set of I/Os started, kernel version only */
741 void rf_DiskIOComplete(queue, req, status)
742 RF_DiskQueue_t *queue;
743 RF_DiskQueueData_t *req;
744 int status;
745 {
746 int done=0;
747
748 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOComplete" );
749
750 /* unlock the queue:
751 (1) after an unlocking req completes
752 (2) after a locking req fails
753 */
754 if (RF_UNLOCKING_REQ(req) || (RF_LOCKING_REQ(req) && status)) {
755 Dprintf2("DiskIOComplete: unlocking queue at r %d c %d\n", queue->row, queue->col);
756 RF_ASSERT(RF_QUEUE_LOCKED(queue) && (queue->unlockingOp == NULL));
757 RF_UNLOCK_QUEUE(queue);
758 }
759
760 queue->numOutstanding--;
761 RF_ASSERT(queue->numOutstanding >= 0);
762
763 /* dispatch requests to the disk until we find one that we can't. */
764 /* no reason to continue once we've filled up the queue */
765 /* no reason to even start if the queue is locked */
766
767 while (!done && !RF_QUEUE_FULL(queue) && !RF_QUEUE_LOCKED(queue)) {
768 if (queue->nextLockingOp) {
769 req = queue->nextLockingOp; queue->nextLockingOp = NULL;
770 Dprintf3("DiskIOComplete: a pri %d locking req was pending at r %d c %d\n",req->priority,queue->row, queue->col);
771 } else {
772 req = (queue->qPtr->Dequeue)( queue->qHdr );
773 if (req != NULL) {
774 Dprintf3("DiskIOComplete: extracting pri %d req from queue at r %d c %d\n",req->priority,queue->row, queue->col);
775 } else {
776 Dprintf1("DiskIOComplete: no more requests to extract.\n","");
777 }
778 }
779 if (req) {
780 queue->queueLength--; /* decrement count of number of requests waiting in this queue */
781 RF_ASSERT(queue->queueLength >= 0);
782 }
783 if (!req) done=1;
784 else if (RF_LOCKING_REQ(req)) {
785 if (RF_QUEUE_EMPTY(queue)) { /* dispatch it */
786 Dprintf3("DiskIOComplete: dispatching pri %d locking req to r %d c %d (queue empty)\n",req->priority,queue->row, queue->col);
787 RF_LOCK_QUEUE(queue);
788 rf_DispatchKernelIO(queue, req);
789 done = 1;
790 } else { /* put it aside to wait for the queue to drain */
791 Dprintf3("DiskIOComplete: postponing pri %d locking req to r %d c %d\n",req->priority,queue->row, queue->col);
792 RF_ASSERT(queue->nextLockingOp == NULL);
793 queue->nextLockingOp = req;
794 done = 1;
795 }
796 } else if (RF_UNLOCKING_REQ(req)) { /* should not happen: unlocking ops should not get queued */
797 RF_ASSERT(RF_QUEUE_LOCKED(queue)); /* support it anyway for the future */
798 Dprintf3("DiskIOComplete: dispatching pri %d unl req to r %d c %d (SHOULD NOT SEE THIS)\n",req->priority,queue->row, queue->col);
799 rf_DispatchKernelIO(queue, req);
800 done = 1;
801 } else if (RF_OK_TO_DISPATCH(queue, req)) {
802 Dprintf3("DiskIOComplete: dispatching pri %d regular req to r %d c %d (ok to dispatch)\n",req->priority,queue->row, queue->col);
803 rf_DispatchKernelIO(queue, req);
804 } else { /* we can't dispatch it, so just re-enqueue it. */
805 /* potential trouble here if disk queues batch reqs */
806 Dprintf3("DiskIOComplete: re-enqueueing pri %d regular req to r %d c %d\n",req->priority,queue->row, queue->col);
807 queue->queueLength++;
808 (queue->qPtr->Enqueue)(queue->qHdr, req, req->priority);
809 done = 1;
810 }
811 }
812
813 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOComplete" );
814 }
815 #endif /* !KERNEL */
816
817 /* promotes accesses tagged with the given parityStripeID from low priority
818 * to normal priority. This promotion is optional, meaning that a queue
819 * need not implement it. If there is no promotion routine associated with
820 * a queue, this routine does nothing and returns -1.
821 */
822 int rf_DiskIOPromote(queue, parityStripeID, which_ru)
823 RF_DiskQueue_t *queue;
824 RF_StripeNum_t parityStripeID;
825 RF_ReconUnitNum_t which_ru;
826 {
827 int retval;
828
829 if (!queue->qPtr->Promote)
830 return(-1);
831 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOPromote" );
832 retval = (queue->qPtr->Promote)( queue->qHdr, parityStripeID, which_ru );
833 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOPromote" );
834 return(retval);
835 }
836
837 RF_DiskQueueData_t *rf_CreateDiskQueueData(
838 RF_IoType_t typ,
839 RF_SectorNum_t ssect,
840 RF_SectorCount_t nsect,
841 caddr_t buf,
842 RF_StripeNum_t parityStripeID,
843 RF_ReconUnitNum_t which_ru,
844 int (*wakeF)(void *,int),
845 void *arg,
846 RF_DiskQueueData_t *next,
847 RF_AccTraceEntry_t *tracerec,
848 void *raidPtr,
849 RF_DiskQueueDataFlags_t flags,
850 void *kb_proc)
851 {
852 RF_DiskQueueData_t *p;
853
854 RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd);
855
856 p->sectorOffset = ssect + rf_protectedSectors;
857 p->numSector = nsect;
858 p->type = typ;
859 p->buf = buf;
860 p->parityStripeID= parityStripeID;
861 p->which_ru = which_ru;
862 p->CompleteFunc = wakeF;
863 p->argument = arg;
864 p->next = next;
865 p->tracerec = tracerec;
866 p->priority = RF_IO_NORMAL_PRIORITY;
867 p->AuxFunc = NULL;
868 p->buf2 = NULL;
869 #ifdef SIMULATE
870 p->owner = rf_GetCurrentOwner();
871 #endif /* SIMULATE */
872 p->raidPtr = raidPtr;
873 p->flags = flags;
874 #ifdef KERNEL
875 p->b_proc = kb_proc;
876 #endif /* KERNEL */
877 return(p);
878 }
879
880 RF_DiskQueueData_t *rf_CreateDiskQueueDataFull(
881 RF_IoType_t typ,
882 RF_SectorNum_t ssect,
883 RF_SectorCount_t nsect,
884 caddr_t buf,
885 RF_StripeNum_t parityStripeID,
886 RF_ReconUnitNum_t which_ru,
887 int (*wakeF)(void *,int),
888 void *arg,
889 RF_DiskQueueData_t *next,
890 RF_AccTraceEntry_t *tracerec,
891 int priority,
892 int (*AuxFunc)(void *,...),
893 caddr_t buf2,
894 void *raidPtr,
895 RF_DiskQueueDataFlags_t flags,
896 void *kb_proc)
897 {
898 RF_DiskQueueData_t *p;
899
900 RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd);
901
902 p->sectorOffset = ssect + rf_protectedSectors;
903 p->numSector = nsect;
904 p->type = typ;
905 p->buf = buf;
906 p->parityStripeID= parityStripeID;
907 p->which_ru = which_ru;
908 p->CompleteFunc = wakeF;
909 p->argument = arg;
910 p->next = next;
911 p->tracerec = tracerec;
912 p->priority = priority;
913 p->AuxFunc = AuxFunc;
914 p->buf2 = buf2;
915 #ifdef SIMULATE
916 p->owner = rf_GetCurrentOwner();
917 #endif /* SIMULATE */
918 p->raidPtr = raidPtr;
919 p->flags = flags;
920 #ifdef KERNEL
921 p->b_proc = kb_proc;
922 #endif /* KERNEL */
923 return(p);
924 }
925
926 void rf_FreeDiskQueueData(p)
927 RF_DiskQueueData_t *p;
928 {
929 RF_FREELIST_FREE_CLEAN(rf_dqd_freelist,p,next,clean_dqd);
930 }
931