/* * Functions related to generic timeout handling of requests. */ #include #include #include #include #include "blk.h" #ifdef CONFIG_FAIL_IO_TIMEOUT static DECLARE_FAULT_ATTR(fail_io_timeout); static int __init setup_fail_io_timeout(char *str) { return setup_fault_attr(&fail_io_timeout, str); } __setup("fail_io_timeout=", setup_fail_io_timeout); int blk_should_fake_timeout(struct request_queue *q) { if (!test_bit(QUEUE_FLAG_FAIL_IO, &q->queue_flags)) return 0; return should_fail(&fail_io_timeout, 1); } static int __init fail_io_timeout_debugfs(void) { return init_fault_attr_dentries(&fail_io_timeout, "fail_io_timeout"); } late_initcall(fail_io_timeout_debugfs); ssize_t part_timeout_show(struct device *dev, struct device_attribute *attr, char *buf) { struct gendisk *disk = dev_to_disk(dev); int set = test_bit(QUEUE_FLAG_FAIL_IO, &disk->queue->queue_flags); return sprintf(buf, "%d\n", set != 0); } ssize_t part_timeout_store(struct device *dev, struct device_attribute *attr, const char *buf, size_t count) { struct gendisk *disk = dev_to_disk(dev); int val; if (count) { struct request_queue *q = disk->queue; char *p = (char *) buf; val = simple_strtoul(p, &p, 10); spin_lock_irq(q->queue_lock); if (val) queue_flag_set(QUEUE_FLAG_FAIL_IO, q); else queue_flag_clear(QUEUE_FLAG_FAIL_IO, q); spin_unlock_irq(q->queue_lock); } return count; } #endif /* CONFIG_FAIL_IO_TIMEOUT */ /* * blk_delete_timer - Delete/cancel timer for a given function. * @req: request that we are canceling timer for * */ void blk_delete_timer(struct request *req) { list_del_init(&req->timeout_list); } static void blk_rq_timed_out(struct request *req) { struct request_queue *q = req->q; enum blk_eh_timer_return ret; ret = q->rq_timed_out_fn(req); switch (ret) { case BLK_EH_HANDLED: __blk_complete_request(req); break; case BLK_EH_RESET_TIMER: blk_clear_rq_complete(req); blk_add_timer(req); break; case BLK_EH_NOT_HANDLED: /* * LLD handles this for now but in the future * we can send a request msg to abort the command * and we can move more of the generic scsi eh code to * the blk layer. */ break; default: printk(KERN_ERR "block: bad eh return: %d\n", ret); break; } } void blk_rq_timed_out_timer(unsigned long data) { struct request_queue *q = (struct request_queue *) data; unsigned long flags, next = 0; struct request *rq, *tmp; spin_lock_irqsave(q->queue_lock, flags); list_for_each_entry_safe(rq, tmp, &q->timeout_list, timeout_list) { if (time_after_eq(jiffies, rq->deadline)) { list_del_init(&rq->timeout_list); /* * Check if we raced with end io completion */ if (blk_mark_rq_complete(rq)) continue; blk_rq_timed_out(rq); } else if (!next || time_after(next, rq->deadline)) next = rq->deadline; } /* * next can never be 0 here with the list non-empty, since we always * bump ->deadline to 1 so we can detect if the timer was ever added * or not. See comment in blk_add_timer() */ if (next) mod_timer(&q->timeout, round_jiffies_up(next)); spin_unlock_irqrestore(q->queue_lock, flags); } /** * blk_abort_request -- Request request recovery for the specified command * @req: pointer to the request of interest * * This function requests that the block layer start recovery for the * request by deleting the timer and calling the q's timeout function. * LLDDs who implement their own error recovery MAY ignore the timeout * event if they generated blk_abort_req. Must hold queue lock. */ void blk_abort_request(struct request *req) { if (blk_mark_rq_complete(req)) return; blk_delete_timer(req); blk_rq_timed_out(req); } EXPORT_SYMBOL_GPL(blk_abort_request); /** * blk_add_timer - Start timeout timer for a single request * @req: request that is about to start running. * * Notes: * Each request has its own timer, and as it is added to the queue, we * set up the timer. When the request completes, we cancel the timer. */ void blk_add_timer(struct request *req) { struct request_queue *q = req->q; unsigned long expiry; if (!q->rq_timed_out_fn) return; BUG_ON(!list_empty(&req->timeout_list)); BUG_ON(test_bit(REQ_ATOM_COMPLETE, &req->atomic_flags)); /* * Some LLDs, like scsi, peek at the timeout to prevent a * command from being retried forever. */ if (!req->timeout) req->timeout = q->rq_timeout; req->deadline = jiffies + req->timeout; list_add_tail(&req->timeout_list, &q->timeout_list); /* * If the timer isn't already pending or this timeout is earlier * than an existing one, modify the timer. Round up to next nearest * second. */ expiry = round_jiffies_up(req->deadline); if (!timer_pending(&q->timeout) || time_before(expiry, q->timeout.expires)) mod_timer(&q->timeout, expiry); } /** * blk_abort_queue -- Abort all request on given queue * @queue: pointer to queue * */ void blk_abort_queue(struct request_queue *q) { unsigned long flags; struct request *rq, *tmp; LIST_HEAD(list); /* * Not a request based block device, nothing to abort */ if (!q->request_fn) return; spin_lock_irqsave(q->queue_lock, flags); elv_abort_queue(q); /* * Splice entries to local list, to avoid deadlocking if entries * get readded to the timeout list by error handling */ list_splice_init(&q->timeout_list, &list); list_for_each_entry_safe(rq, tmp, &list, timeout_list) blk_abort_request(rq); /* * Occasionally, blk_abort_request() will return without * deleting the element from the list. Make sure we add those back * instead of leaving them on the local stack list. */ list_splice(&list, &q->timeout_list); spin_unlock_irqrestore(q->queue_lock, flags); } EXPORT_SYMBOL_GPL(blk_abort_queue); n52' href='#n52'>52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 
/******************************************************************************
 *
 *	(C)Copyright 1998,1999 SysKonnect,
 *	a business unit of Schneider & Koch & Co. Datensysteme GmbH.
 *
 *	See the file "skfddi.c" for further information.
 *
 *	This program is free software; you can redistribute it and/or modify
 *	it under the terms of the GNU General Public License as published by
 *	the Free Software Foundation; either version 2 of the License, or
 *	(at your option) any later version.
 *
 *	The information in this file is provided "AS IS" without warranty.
 *
 ******************************************************************************/

/*
	SMT CFM
	Configuration Management
	DAS with single MAC
*/

/*
 *	Hardware independent state machine implemantation
 *	The following external SMT functions are referenced :
 *
 *		queue_event()
 *
 *	The following external HW dependent functions are referenced :
 *		config_mux()
 *
 *	The following HW dependent events are required :
 *		NONE 
 */

#include "h/types.h"
#include "h/fddi.h"
#include "h/smc.h"

#define KERNEL
#include "h/smtstate.h"

#ifndef	lint
static const char ID_sccs[] = "@(#)cfm.c	2.18 98/10/06 (C) SK " ;
#endif

/*
 * FSM Macros
 */
#define AFLAG	0x10
#define GO_STATE(x)	(smc->mib.fddiSMTCF_State = (x)|AFLAG)
#define ACTIONS_DONE()	(smc->mib.fddiSMTCF_State &= ~AFLAG)
#define ACTIONS(x)	(x|AFLAG)

#ifdef	DEBUG
/*
 * symbolic state names
 */
static const char * const cfm_states[] = {
	"SC0_ISOLATED","CF1","CF2","CF3","CF4",
	"SC1_WRAP_A","SC2_WRAP_B","SC5_TRHU_B","SC7_WRAP_S",
	"SC9_C_WRAP_A","SC10_C_WRAP_B","SC11_C_WRAP_S","SC4_THRU_A"
} ;

/*
 * symbolic event names
 */
static const char * const cfm_events[] = {
	"NONE","CF_LOOP_A","CF_LOOP_B","CF_JOIN_A","CF_JOIN_B"
} ;
#endif

/*
 * map from state to downstream port type
 */
static const u_char cf_to_ptype[] = {
	TNONE,TNONE,TNONE,TNONE,TNONE,
	TNONE,TB,TB,TS,
	TA,TB,TS,TB
} ;

/*
 * CEM port states
 */
#define	CEM_PST_DOWN	0
#define	CEM_PST_UP	1
#define	CEM_PST_HOLD	2
/* define portstate array only for A and B port */
/* Do this within the smc structure (use in multiple cards) */

/*
 * all Globals  are defined in smc.h
 * struct s_cfm
 */

/*
 * function declarations
 */
static void cfm_fsm(struct s_smc *smc, int cmd);

/*
	init CFM state machine
	clear all CFM vars and flags
*/
void cfm_init(struct s_smc *smc)
{
	smc->mib.fddiSMTCF_State = ACTIONS(SC0_ISOLATED) ;
	smc->r.rm_join = 0 ;
	smc->r.rm_loop = 0 ;
	smc->y[PA].scrub = 0 ;
	smc->y[PB].scrub = 0 ;
	smc->y[PA].cem_pst = CEM_PST_DOWN ;
	smc->y[PB].cem_pst = CEM_PST_DOWN ;
}

/* Some terms conditions used by the selection criteria */
#define THRU_ENABLED(smc)	(smc->y[PA].pc_mode != PM_TREE && \
				 smc->y[PB].pc_mode != PM_TREE)
/* Selection criteria for the ports */
static void selection_criteria (struct s_smc *smc, struct s_phy *phy)
{

	switch (phy->mib->fddiPORTMy_Type) {
	case TA:
		if ( !THRU_ENABLED(smc) && smc->y[PB].cf_join ) {
			phy->wc_flag = TRUE ;
		} else {
			phy->wc_flag = FALSE ;
		}

		break;
	case TB:
		/* take precedence over PA */
		phy->wc_flag = FALSE ;
		break;
	case TS:
		phy->wc_flag = FALSE ;
		break;
	case TM:
		phy->wc_flag = FALSE ;
		break;
	}

}

void all_selection_criteria(struct s_smc *smc)
{
	struct s_phy	*phy ;
	int		p ;

	for ( p = 0,phy = smc->y ; p < NUMPHYS; p++, phy++ ) {
		/* Do the selection criteria */
		selection_criteria (smc,phy);
	}
}

static void cem_priv_state(struct s_smc *smc, int event)
/* State machine for private PORT states: used to optimize dual homing */
{
	int	np;	/* Number of the port */
	int	i;

	/* Do this only in a DAS */
	if (smc->s.sas != SMT_DAS )
		return ;

	np = event - CF_JOIN;

	if (np != PA && np != PB) {
		return ;
	}
	/* Change the port state according to the event (portnumber) */
	if (smc->y[np].cf_join) {
		smc->y[np].cem_pst = CEM_PST_UP ;
	} else if (!smc->y[np].wc_flag) {
		/* set the port to done only if it is not withheld */
		smc->y[np].cem_pst = CEM_PST_DOWN ;
	}

	/* Don't set an hold port to down */

	/* Check all ports of restart conditions */
	for (i = 0 ; i < 2 ; i ++ ) {
		/* Check all port for PORT is on hold and no withhold is done */
		if ( smc->y[i].cem_pst == CEM_PST_HOLD && !smc->y[i].wc_flag ) {
			smc->y[i].cem_pst = CEM_PST_DOWN;
			queue_event(smc,(int)(EVENT_PCM+i),PC_START) ;
		}
		if ( smc->y[i].cem_pst == CEM_PST_UP && smc->y[i].wc_flag ) {
			smc->y[i].cem_pst = CEM_PST_HOLD;
			queue_event(smc,(int)(EVENT_PCM+i),PC_START) ;
		}
		if ( smc->y[i].cem_pst == CEM_PST_DOWN && smc->y[i].wc_flag ) {
			/*