rf_diskqueue.c revision 1.1 1 /* $NetBSD: rf_diskqueue.c,v 1.1 1998/11/13 04:20:29 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 memset(dqd->bp,0,sizeof(struct buf)); /* if you don't do it, nobody else will.. */
355 /* XXX */
356 /* printf("NEED TO IMPLEMENT THIS BETTER!\n"); */
357 #else
358 dqd->bp = ubc_bufget();
359 #endif
360 if (dqd->bp == NULL) {
361 return(ENOMEM);
362 }
363 #endif /* KERNEL */
364 return(0);
365 }
366
367 static void clean_dqd(dqd)
368 RF_DiskQueueData_t *dqd;
369 {
370 #ifdef KERNEL
371 #ifdef __NetBSD__
372 /* printf("NEED TO IMPLEMENT THIS BETTER(2)!\n"); */
373 /* XXX ? */
374 free( dqd->bp, M_DEVBUF );
375 #else
376 ubc_buffree(dqd->bp);
377 #endif
378
379 #endif /* KERNEL */
380 }
381
382 /* configures a single disk queue */
383 static int config_disk_queue(
384 RF_Raid_t *raidPtr,
385 RF_DiskQueue_t *diskqueue,
386 RF_RowCol_t r, /* row & col -- debug only. BZZT not any more... */
387 RF_RowCol_t c,
388 RF_DiskQueueSW_t *p,
389 RF_SectorCount_t sectPerDisk,
390 dev_t dev,
391 int maxOutstanding,
392 RF_ShutdownList_t **listp,
393 RF_AllocListElem_t *clList)
394 {
395 int rc;
396
397 diskqueue->row = r;
398 diskqueue->col = c;
399 diskqueue->qPtr = p;
400 diskqueue->qHdr = (p->Create)(sectPerDisk, clList, listp);
401 diskqueue->dev = dev;
402 diskqueue->numOutstanding = 0;
403 diskqueue->queueLength = 0;
404 diskqueue->maxOutstanding = maxOutstanding;
405 diskqueue->curPriority = RF_IO_NORMAL_PRIORITY;
406 diskqueue->nextLockingOp = NULL;
407 diskqueue->unlockingOp = NULL;
408 diskqueue->numWaiting=0;
409 diskqueue->flags = 0;
410 diskqueue->raidPtr = raidPtr;
411 #if defined(__NetBSD__) && defined(_KERNEL)
412 diskqueue->rf_cinfo = &raidPtr->raid_cinfo[r][c];
413 #endif
414 rc = rf_create_managed_mutex(listp, &diskqueue->mutex);
415 if (rc) {
416 RF_ERRORMSG3("Unable to init mutex file %s line %d rc=%d\n", __FILE__,
417 __LINE__, rc);
418 return(rc);
419 }
420 rc = rf_create_managed_cond(listp, &diskqueue->cond);
421 if (rc) {
422 RF_ERRORMSG3("Unable to init cond file %s line %d rc=%d\n", __FILE__,
423 __LINE__, rc);
424 return(rc);
425 }
426 return(0);
427 }
428
429 static void rf_ShutdownDiskQueueSystem(ignored)
430 void *ignored;
431 {
432 RF_FREELIST_DESTROY_CLEAN(rf_dqd_freelist,next,(RF_DiskQueueData_t *),clean_dqd);
433 }
434
435 int rf_ConfigureDiskQueueSystem(listp)
436 RF_ShutdownList_t **listp;
437 {
438 int rc;
439
440 RF_FREELIST_CREATE(rf_dqd_freelist, RF_MAX_FREE_DQD,
441 RF_DQD_INC, sizeof(RF_DiskQueueData_t));
442 if (rf_dqd_freelist == NULL)
443 return(ENOMEM);
444 rc = rf_ShutdownCreate(listp, rf_ShutdownDiskQueueSystem, NULL);
445 if (rc) {
446 RF_ERRORMSG3("Unable to add to shutdown list file %s line %d rc=%d\n",
447 __FILE__, __LINE__, rc);
448 rf_ShutdownDiskQueueSystem(NULL);
449 return(rc);
450 }
451 RF_FREELIST_PRIME_INIT(rf_dqd_freelist, RF_DQD_INITIAL,next,
452 (RF_DiskQueueData_t *),init_dqd);
453 return(0);
454 }
455
456 #ifndef KERNEL
457 /* this is called prior to shutdown to wakeup everyone waiting on a disk queue
458 * and tell them to exit
459 */
460 void rf_TerminateDiskQueues(raidPtr)
461 RF_Raid_t *raidPtr;
462 {
463 RF_RowCol_t r, c;
464
465 raidPtr->terminate_disk_queues = 1;
466 for (r=0; r<raidPtr->numRow; r++) {
467 for (c=0; c<raidPtr->numCol + ((r==0) ? raidPtr->numSpare : 0); c++) {
468 RF_LOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues");
469 RF_BROADCAST_COND(raidPtr->Queues[r][c].cond);
470 RF_UNLOCK_QUEUE_MUTEX(&raidPtr->Queues[r][c], "TerminateDiskQueues");
471 }
472 }
473 }
474 #endif /* !KERNEL */
475
476 int rf_ConfigureDiskQueues(
477 RF_ShutdownList_t **listp,
478 RF_Raid_t *raidPtr,
479 RF_Config_t *cfgPtr)
480 {
481 RF_DiskQueue_t **diskQueues, *spareQueues;
482 RF_DiskQueueSW_t *p;
483 RF_RowCol_t r, c;
484 int rc, i;
485
486 raidPtr->maxQueueDepth = cfgPtr->maxOutstandingDiskReqs;
487
488 for(p=NULL,i=0;i<NUM_DISK_QUEUE_TYPES;i++) {
489 if (!strcmp(diskqueuesw[i].queueType, cfgPtr->diskQueueType)) {
490 p = &diskqueuesw[i];
491 break;
492 }
493 }
494 if (p == NULL) {
495 RF_ERRORMSG2("Unknown queue type \"%s\". Using %s\n",cfgPtr->diskQueueType, diskqueuesw[0].queueType);
496 p = &diskqueuesw[0];
497 }
498
499 RF_CallocAndAdd(diskQueues, raidPtr->numRow, sizeof(RF_DiskQueue_t *), (RF_DiskQueue_t **), raidPtr->cleanupList);
500 if (diskQueues == NULL) {
501 return(ENOMEM);
502 }
503 raidPtr->Queues = diskQueues;
504 for (r=0; r<raidPtr->numRow; r++) {
505 RF_CallocAndAdd(diskQueues[r], raidPtr->numCol + ((r==0) ? raidPtr->numSpare : 0), sizeof(RF_DiskQueue_t), (RF_DiskQueue_t *), raidPtr->cleanupList);
506 if (diskQueues[r] == NULL)
507 return(ENOMEM);
508 for (c=0; c<raidPtr->numCol; c++) {
509 rc = config_disk_queue(raidPtr, &diskQueues[r][c], r, c, p,
510 raidPtr->sectorsPerDisk, raidPtr->Disks[r][c].dev,
511 cfgPtr->maxOutstandingDiskReqs, listp, raidPtr->cleanupList);
512 if (rc)
513 return(rc);
514 }
515 }
516
517 spareQueues = &raidPtr->Queues[0][raidPtr->numCol];
518 for (r=0; r<raidPtr->numSpare; r++) {
519 rc = config_disk_queue(raidPtr, &spareQueues[r],
520 0, raidPtr->numCol+r, p,
521 raidPtr->sectorsPerDisk,
522 raidPtr->Disks[0][raidPtr->numCol+r].dev,
523 cfgPtr->maxOutstandingDiskReqs, listp,
524 raidPtr->cleanupList);
525 if (rc)
526 return(rc);
527 }
528 return(0);
529 }
530
531 /* Enqueue a disk I/O
532 *
533 * Unfortunately, we have to do things differently in the different
534 * environments (simulator, user-level, kernel).
535 * At user level, all I/O is blocking, so we have 1 or more threads/disk
536 * and the thread that enqueues is different from the thread that dequeues.
537 * In the kernel, I/O is non-blocking and so we'd like to have multiple
538 * I/Os outstanding on the physical disks when possible.
539 *
540 * when any request arrives at a queue, we have two choices:
541 * dispatch it to the lower levels
542 * queue it up
543 *
544 * kernel rules for when to do what:
545 * locking request: queue empty => dispatch and lock queue,
546 * else queue it
547 * unlocking req : always dispatch it
548 * normal req : queue empty => dispatch it & set priority
549 * queue not full & priority is ok => dispatch it
550 * else queue it
551 *
552 * user-level rules:
553 * always enqueue. In the special case of an unlocking op, enqueue
554 * in a special way that will cause the unlocking op to be the next
555 * thing dequeued.
556 *
557 * simulator rules:
558 * Do the same as at user level, with the sleeps and wakeups suppressed.
559 */
560 void rf_DiskIOEnqueue(queue, req, pri)
561 RF_DiskQueue_t *queue;
562 RF_DiskQueueData_t *req;
563 int pri;
564 {
565 int tid;
566
567 RF_ETIMER_START(req->qtime);
568 rf_get_threadid(tid);
569 RF_ASSERT(req->type == RF_IO_TYPE_NOP || req->numSector);
570 req->priority = pri;
571
572 if (rf_queueDebug && (req->numSector == 0)) {
573 printf("Warning: Enqueueing zero-sector access\n");
574 }
575
576 #ifdef KERNEL
577 /*
578 * kernel
579 */
580 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
581 /* locking request */
582 if (RF_LOCKING_REQ(req)) {
583 if (RF_QUEUE_EMPTY(queue)) {
584 Dprintf3("Dispatching pri %d locking op to r %d c %d (queue empty)\n",pri,queue->row, queue->col);
585 RF_LOCK_QUEUE(queue);
586 rf_DispatchKernelIO(queue, req);
587 } else {
588 queue->queueLength++; /* increment count of number of requests waiting in this queue */
589 Dprintf3("Enqueueing pri %d locking op to r %d c %d (queue not empty)\n",pri,queue->row, queue->col);
590 req->queue = (void *)queue;
591 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
592 }
593 }
594 /* unlocking request */
595 else if (RF_UNLOCKING_REQ(req)) { /* we'll do the actual unlock when this I/O completes */
596 Dprintf3("Dispatching pri %d unlocking op to r %d c %d\n",pri,queue->row, queue->col);
597 RF_ASSERT(RF_QUEUE_LOCKED(queue));
598 rf_DispatchKernelIO(queue, req);
599 }
600 /* normal request */
601 else if (RF_OK_TO_DISPATCH(queue, req)) {
602 Dprintf3("Dispatching pri %d regular op to r %d c %d (ok to dispatch)\n",pri,queue->row, queue->col);
603 rf_DispatchKernelIO(queue, req);
604 } else {
605 queue->queueLength++; /* increment count of number of requests waiting in this queue */
606 Dprintf3("Enqueueing pri %d regular op to r %d c %d (not ok to dispatch)\n",pri,queue->row, queue->col);
607 req->queue = (void *)queue;
608 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
609 }
610 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
611
612 #else /* KERNEL */
613 /*
614 * user-level
615 */
616 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
617 queue->queueLength++; /* increment count of number of requests waiting in this queue */
618 /* unlocking request */
619 if (RF_UNLOCKING_REQ(req)) {
620 Dprintf4("[%d] enqueueing pri %d unlocking op & signalling r %d c %d\n", tid, pri, queue->row, queue->col);
621 RF_ASSERT(RF_QUEUE_LOCKED(queue) && queue->unlockingOp == NULL);
622 queue->unlockingOp = req;
623 }
624 /* locking and normal requests */
625 else {
626 req->queue = (void *)queue;
627 Dprintf5("[%d] enqueueing pri %d %s op & signalling r %d c %d\n", tid, pri,
628 (RF_LOCKING_REQ(req)) ? "locking" : "regular",queue->row,queue->col);
629 (queue->qPtr->Enqueue)(queue->qHdr, req, pri);
630 }
631 SIGNAL_DISK_QUEUE( queue, "DiskIOEnqueue");
632 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOEnqueue" );
633 #endif /* KERNEL */
634 }
635
636 #if !defined(KERNEL) && !defined(SIMULATE)
637 /* user-level only: tell all threads to wake up & recheck the queue */
638 void rf_BroadcastOnQueue(queue)
639 RF_DiskQueue_t *queue;
640 {
641 int i;
642
643 if (queue->maxOutstanding > 1) for (i=0; i<queue->maxOutstanding; i++) {
644 SIGNAL_DISK_QUEUE(queue, "BroadcastOnQueue" );
645 }
646 }
647 #endif /* !KERNEL && !SIMULATE */
648
649 #ifndef KERNEL /* not used in kernel */
650
651 RF_DiskQueueData_t *rf_DiskIODequeue(queue)
652 RF_DiskQueue_t *queue;
653 {
654 RF_DiskQueueData_t *p, *headItem;
655 int tid;
656
657 rf_get_threadid(tid);
658 RF_LOCK_QUEUE_MUTEX( queue, "DiskIODequeue" );
659 for (p=NULL; !p; ) {
660 if (queue->unlockingOp) {
661 /* unlocking request */
662 RF_ASSERT(RF_QUEUE_LOCKED(queue));
663 p = queue->unlockingOp;
664 queue->unlockingOp = NULL;
665 Dprintf4("[%d] dequeueing pri %d unlocking op r %d c %d\n", tid, p->priority, queue->row,queue->col);
666 }
667 else {
668 headItem = (queue->qPtr->Peek)(queue->qHdr);
669 if (headItem) {
670 if (RF_LOCKING_REQ(headItem)) {
671 /* locking request */
672 if (!RF_QUEUE_LOCKED(queue)) {
673 /* queue isn't locked, so dequeue the request & lock the queue */
674 p = (queue->qPtr->Dequeue)( queue->qHdr );
675 if (p)
676 Dprintf4("[%d] dequeueing pri %d locking op r %d c %d\n", tid, p->priority, queue->row, queue->col);
677 else
678 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
679 }
680 else {
681 /* queue already locked, no dequeue occurs */
682 Dprintf3("[%d] no dequeue -- queue is locked r %d c %d\n", tid, queue->row, queue->col);
683 p = NULL;
684 }
685 }
686 else {
687 /* normal request, always dequeue and assume caller already has lock (if needed) */
688 p = (queue->qPtr->Dequeue)( queue->qHdr );
689 if (p)
690 Dprintf4("[%d] dequeueing pri %d regular op r %d c %d\n", tid, p->priority, queue->row, queue->col);
691 else
692 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
693 }
694 }
695 else {
696 Dprintf3("[%d] no dequeue -- raw queue empty r %d c %d\n", tid, queue->row, queue->col);
697 }
698 }
699
700 if (queue->raidPtr->terminate_disk_queues) {
701 p = NULL;
702 break;
703 }
704 #ifdef SIMULATE
705 break; /* in simulator, return NULL on empty queue instead of blocking */
706 #else /* SIMULATE */
707 if (!p) {
708 Dprintf3("[%d] nothing to dequeue: waiting r %d c %d\n", tid, queue->row, queue->col);
709 WAIT_DISK_QUEUE( queue, "DiskIODequeue" );
710 }
711 #endif /* SIMULATE */
712 }
713
714 if (p) {
715 queue->queueLength--; /* decrement count of number of requests waiting in this queue */
716 RF_ASSERT(queue->queueLength >= 0);
717 queue->numOutstanding++;
718 queue->last_deq_sector = p->sectorOffset;
719 /* record the amount of time this request spent in the disk queue */
720 RF_ETIMER_STOP(p->qtime);
721 RF_ETIMER_EVAL(p->qtime);
722 if (p->tracerec)
723 p->tracerec->diskqueue_us += RF_ETIMER_VAL_US(p->qtime);
724 }
725
726 if (p && RF_LOCKING_REQ(p)) {
727 RF_ASSERT(!RF_QUEUE_LOCKED(queue));
728 Dprintf3("[%d] locking queue r %d c %d\n",tid,queue->row,queue->col);
729 RF_LOCK_QUEUE(queue);
730 }
731 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIODequeue" );
732
733 return(p);
734 }
735
736 #else /* !KERNEL */
737
738 /* get the next set of I/Os started, kernel version only */
739 void rf_DiskIOComplete(queue, req, status)
740 RF_DiskQueue_t *queue;
741 RF_DiskQueueData_t *req;
742 int status;
743 {
744 int done=0;
745
746 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOComplete" );
747
748 /* unlock the queue:
749 (1) after an unlocking req completes
750 (2) after a locking req fails
751 */
752 if (RF_UNLOCKING_REQ(req) || (RF_LOCKING_REQ(req) && status)) {
753 Dprintf2("DiskIOComplete: unlocking queue at r %d c %d\n", queue->row, queue->col);
754 RF_ASSERT(RF_QUEUE_LOCKED(queue) && (queue->unlockingOp == NULL));
755 RF_UNLOCK_QUEUE(queue);
756 }
757
758 queue->numOutstanding--;
759 RF_ASSERT(queue->numOutstanding >= 0);
760
761 /* dispatch requests to the disk until we find one that we can't. */
762 /* no reason to continue once we've filled up the queue */
763 /* no reason to even start if the queue is locked */
764
765 while (!done && !RF_QUEUE_FULL(queue) && !RF_QUEUE_LOCKED(queue)) {
766 if (queue->nextLockingOp) {
767 req = queue->nextLockingOp; queue->nextLockingOp = NULL;
768 Dprintf3("DiskIOComplete: a pri %d locking req was pending at r %d c %d\n",req->priority,queue->row, queue->col);
769 } else {
770 req = (queue->qPtr->Dequeue)( queue->qHdr );
771 Dprintf3("DiskIOComplete: extracting pri %d req from queue at r %d c %d\n",req->priority,queue->row, queue->col);
772 }
773 if (req) {
774 queue->queueLength--; /* decrement count of number of requests waiting in this queue */
775 RF_ASSERT(queue->queueLength >= 0);
776 }
777 if (!req) done=1;
778 else if (RF_LOCKING_REQ(req)) {
779 if (RF_QUEUE_EMPTY(queue)) { /* dispatch it */
780 Dprintf3("DiskIOComplete: dispatching pri %d locking req to r %d c %d (queue empty)\n",req->priority,queue->row, queue->col);
781 RF_LOCK_QUEUE(queue);
782 rf_DispatchKernelIO(queue, req);
783 done = 1;
784 } else { /* put it aside to wait for the queue to drain */
785 Dprintf3("DiskIOComplete: postponing pri %d locking req to r %d c %d\n",req->priority,queue->row, queue->col);
786 RF_ASSERT(queue->nextLockingOp == NULL);
787 queue->nextLockingOp = req;
788 done = 1;
789 }
790 } else if (RF_UNLOCKING_REQ(req)) { /* should not happen: unlocking ops should not get queued */
791 RF_ASSERT(RF_QUEUE_LOCKED(queue)); /* support it anyway for the future */
792 Dprintf3("DiskIOComplete: dispatching pri %d unl req to r %d c %d (SHOULD NOT SEE THIS)\n",req->priority,queue->row, queue->col);
793 rf_DispatchKernelIO(queue, req);
794 done = 1;
795 } else if (RF_OK_TO_DISPATCH(queue, req)) {
796 Dprintf3("DiskIOComplete: dispatching pri %d regular req to r %d c %d (ok to dispatch)\n",req->priority,queue->row, queue->col);
797 rf_DispatchKernelIO(queue, req);
798 } else { /* we can't dispatch it, so just re-enqueue it. */
799 /* potential trouble here if disk queues batch reqs */
800 Dprintf3("DiskIOComplete: re-enqueueing pri %d regular req to r %d c %d\n",req->priority,queue->row, queue->col);
801 queue->queueLength++;
802 (queue->qPtr->Enqueue)(queue->qHdr, req, req->priority);
803 done = 1;
804 }
805 }
806
807 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOComplete" );
808 }
809 #endif /* !KERNEL */
810
811 /* promotes accesses tagged with the given parityStripeID from low priority
812 * to normal priority. This promotion is optional, meaning that a queue
813 * need not implement it. If there is no promotion routine associated with
814 * a queue, this routine does nothing and returns -1.
815 */
816 int rf_DiskIOPromote(queue, parityStripeID, which_ru)
817 RF_DiskQueue_t *queue;
818 RF_StripeNum_t parityStripeID;
819 RF_ReconUnitNum_t which_ru;
820 {
821 int retval;
822
823 if (!queue->qPtr->Promote)
824 return(-1);
825 RF_LOCK_QUEUE_MUTEX( queue, "DiskIOPromote" );
826 retval = (queue->qPtr->Promote)( queue->qHdr, parityStripeID, which_ru );
827 RF_UNLOCK_QUEUE_MUTEX( queue, "DiskIOPromote" );
828 return(retval);
829 }
830
831 RF_DiskQueueData_t *rf_CreateDiskQueueData(
832 RF_IoType_t typ,
833 RF_SectorNum_t ssect,
834 RF_SectorCount_t nsect,
835 caddr_t buf,
836 RF_StripeNum_t parityStripeID,
837 RF_ReconUnitNum_t which_ru,
838 int (*wakeF)(void *,int),
839 void *arg,
840 RF_DiskQueueData_t *next,
841 RF_AccTraceEntry_t *tracerec,
842 void *raidPtr,
843 RF_DiskQueueDataFlags_t flags,
844 void *kb_proc)
845 {
846 RF_DiskQueueData_t *p;
847
848 RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd);
849
850 p->sectorOffset = ssect + rf_protectedSectors;
851 p->numSector = nsect;
852 p->type = typ;
853 p->buf = buf;
854 p->parityStripeID= parityStripeID;
855 p->which_ru = which_ru;
856 p->CompleteFunc = wakeF;
857 p->argument = arg;
858 p->next = next;
859 p->tracerec = tracerec;
860 p->priority = RF_IO_NORMAL_PRIORITY;
861 p->AuxFunc = NULL;
862 p->buf2 = NULL;
863 #ifdef SIMULATE
864 p->owner = rf_GetCurrentOwner();
865 #endif /* SIMULATE */
866 p->raidPtr = raidPtr;
867 p->flags = flags;
868 #ifdef KERNEL
869 p->b_proc = kb_proc;
870 #endif /* KERNEL */
871 return(p);
872 }
873
874 RF_DiskQueueData_t *rf_CreateDiskQueueDataFull(
875 RF_IoType_t typ,
876 RF_SectorNum_t ssect,
877 RF_SectorCount_t nsect,
878 caddr_t buf,
879 RF_StripeNum_t parityStripeID,
880 RF_ReconUnitNum_t which_ru,
881 int (*wakeF)(void *,int),
882 void *arg,
883 RF_DiskQueueData_t *next,
884 RF_AccTraceEntry_t *tracerec,
885 int priority,
886 int (*AuxFunc)(void *,...),
887 caddr_t buf2,
888 void *raidPtr,
889 RF_DiskQueueDataFlags_t flags,
890 void *kb_proc)
891 {
892 RF_DiskQueueData_t *p;
893
894 RF_FREELIST_GET_INIT(rf_dqd_freelist,p,next,(RF_DiskQueueData_t *),init_dqd);
895
896 p->sectorOffset = ssect + rf_protectedSectors;
897 p->numSector = nsect;
898 p->type = typ;
899 p->buf = buf;
900 p->parityStripeID= parityStripeID;
901 p->which_ru = which_ru;
902 p->CompleteFunc = wakeF;
903 p->argument = arg;
904 p->next = next;
905 p->tracerec = tracerec;
906 p->priority = priority;
907 p->AuxFunc = AuxFunc;
908 p->buf2 = buf2;
909 #ifdef SIMULATE
910 p->owner = rf_GetCurrentOwner();
911 #endif /* SIMULATE */
912 p->raidPtr = raidPtr;
913 p->flags = flags;
914 #ifdef KERNEL
915 p->b_proc = kb_proc;
916 #endif /* KERNEL */
917 return(p);
918 }
919
920 void rf_FreeDiskQueueData(p)
921 RF_DiskQueueData_t *p;
922 {
923 RF_FREELIST_FREE_CLEAN(rf_dqd_freelist,p,next,clean_dqd);
924 }
925