1 /* 2 * CDDL HEADER START 3 * 4 * The contents of this file are subject to the terms of the 5 * Common Development and Distribution License (the "License"). 6 * You may not use this file except in compliance with the License. 7 * 8 * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE 9 * or http://www.opensolaris.org/os/licensing. 10 * See the License for the specific language governing permissions 11 * and limitations under the License. 12 * 13 * When distributing Covered Code, include this CDDL HEADER in each 14 * file and include the License file at usr/src/OPENSOLARIS.LICENSE. 15 * If applicable, add the following below this CDDL HEADER, with the 16 * fields enclosed by brackets "[]" replaced with your own identifying 17 * information: Portions Copyright [yyyy] [name of copyright owner] 18 * 19 * CDDL HEADER END 20 */ 21 /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ 22 /* All Rights Reserved */ 23 24 25 /* 26 * Copyright 2010 Sun Microsystems, Inc. All rights reserved. 27 * Use is subject to license terms. 28 */ 29 30 #include <sys/types.h> 31 #include <sys/sysmacros.h> 32 #include <sys/param.h> 33 #include <sys/errno.h> 34 #include <sys/signal.h> 35 #include <sys/proc.h> 36 #include <sys/conf.h> 37 #include <sys/cred.h> 38 #include <sys/user.h> 39 #include <sys/vnode.h> 40 #include <sys/file.h> 41 #include <sys/session.h> 42 #include <sys/stream.h> 43 #include <sys/strsubr.h> 44 #include <sys/stropts.h> 45 #include <sys/poll.h> 46 #include <sys/systm.h> 47 #include <sys/cpuvar.h> 48 #include <sys/uio.h> 49 #include <sys/cmn_err.h> 50 #include <sys/priocntl.h> 51 #include <sys/procset.h> 52 #include <sys/vmem.h> 53 #include <sys/bitmap.h> 54 #include <sys/kmem.h> 55 #include <sys/siginfo.h> 56 #include <sys/vtrace.h> 57 #include <sys/callb.h> 58 #include <sys/debug.h> 59 #include <sys/modctl.h> 60 #include <sys/vmsystm.h> 61 #include <vm/page.h> 62 #include <sys/atomic.h> 63 #include <sys/suntpi.h> 64 #include <sys/strlog.h> 65 #include <sys/promif.h> 66 #include <sys/project.h> 67 #include <sys/vm.h> 68 #include <sys/taskq.h> 69 #include <sys/sunddi.h> 70 #include <sys/sunldi_impl.h> 71 #include <sys/strsun.h> 72 #include <sys/isa_defs.h> 73 #include <sys/multidata.h> 74 #include <sys/pattr.h> 75 #include <sys/strft.h> 76 #include <sys/fs/snode.h> 77 #include <sys/zone.h> 78 #include <sys/open.h> 79 #include <sys/sunldi.h> 80 #include <sys/sad.h> 81 #include <sys/netstack.h> 82 83 #define O_SAMESTR(q) (((q)->q_next) && \ 84 (((q)->q_flag & QREADR) == ((q)->q_next->q_flag & QREADR))) 85 86 /* 87 * WARNING: 88 * The variables and routines in this file are private, belonging 89 * to the STREAMS subsystem. These should not be used by modules 90 * or drivers. Compatibility will not be guaranteed. 91 */ 92 93 /* 94 * Id value used to distinguish between different multiplexor links. 95 */ 96 static int32_t lnk_id = 0; 97 98 #define STREAMS_LOPRI MINCLSYSPRI 99 static pri_t streams_lopri = STREAMS_LOPRI; 100 101 #define STRSTAT(x) (str_statistics.x.value.ui64++) 102 typedef struct str_stat { 103 kstat_named_t sqenables; 104 kstat_named_t stenables; 105 kstat_named_t syncqservice; 106 kstat_named_t freebs; 107 kstat_named_t qwr_outer; 108 kstat_named_t rservice; 109 kstat_named_t strwaits; 110 kstat_named_t taskqfails; 111 kstat_named_t bufcalls; 112 kstat_named_t qhelps; 113 kstat_named_t qremoved; 114 kstat_named_t sqremoved; 115 kstat_named_t bcwaits; 116 kstat_named_t sqtoomany; 117 } str_stat_t; 118 119 static str_stat_t str_statistics = { 120 { "sqenables", KSTAT_DATA_UINT64 }, 121 { "stenables", KSTAT_DATA_UINT64 }, 122 { "syncqservice", KSTAT_DATA_UINT64 }, 123 { "freebs", KSTAT_DATA_UINT64 }, 124 { "qwr_outer", KSTAT_DATA_UINT64 }, 125 { "rservice", KSTAT_DATA_UINT64 }, 126 { "strwaits", KSTAT_DATA_UINT64 }, 127 { "taskqfails", KSTAT_DATA_UINT64 }, 128 { "bufcalls", KSTAT_DATA_UINT64 }, 129 { "qhelps", KSTAT_DATA_UINT64 }, 130 { "qremoved", KSTAT_DATA_UINT64 }, 131 { "sqremoved", KSTAT_DATA_UINT64 }, 132 { "bcwaits", KSTAT_DATA_UINT64 }, 133 { "sqtoomany", KSTAT_DATA_UINT64 }, 134 }; 135 136 static kstat_t *str_kstat; 137 138 /* 139 * qrunflag was used previously to control background scheduling of queues. It 140 * is not used anymore, but kept here in case some module still wants to access 141 * it via qready() and setqsched macros. 142 */ 143 char qrunflag; /* Unused */ 144 145 /* 146 * Most of the streams scheduling is done via task queues. Task queues may fail 147 * for non-sleep dispatches, so there are two backup threads servicing failed 148 * requests for queues and syncqs. Both of these threads also service failed 149 * dispatches freebs requests. Queues are put in the list specified by `qhead' 150 * and `qtail' pointers, syncqs use `sqhead' and `sqtail' pointers and freebs 151 * requests are put into `freebs_list' which has no tail pointer. All three 152 * lists are protected by a single `service_queue' lock and use 153 * `services_to_run' condition variable for signaling background threads. Use of 154 * a single lock should not be a problem because it is only used under heavy 155 * loads when task queues start to fail and at that time it may be a good idea 156 * to throttle scheduling requests. 157 * 158 * NOTE: queues and syncqs should be scheduled by two separate threads because 159 * queue servicing may be blocked waiting for a syncq which may be also 160 * scheduled for background execution. This may create a deadlock when only one 161 * thread is used for both. 162 */ 163 164 static taskq_t *streams_taskq; /* Used for most STREAMS scheduling */ 165 166 static kmutex_t service_queue; /* protects all of servicing vars */ 167 static kcondvar_t services_to_run; /* wake up background service thread */ 168 static kcondvar_t syncqs_to_run; /* wake up background service thread */ 169 170 /* 171 * List of queues scheduled for background processing due to lack of resources 172 * in the task queues. Protected by service_queue lock; 173 */ 174 static struct queue *qhead; 175 static struct queue *qtail; 176 177 /* 178 * Same list for syncqs 179 */ 180 static syncq_t *sqhead; 181 static syncq_t *sqtail; 182 183 static mblk_t *freebs_list; /* list of buffers to free */ 184 185 /* 186 * Backup threads for servicing queues and syncqs 187 */ 188 kthread_t *streams_qbkgrnd_thread; 189 kthread_t *streams_sqbkgrnd_thread; 190 191 /* 192 * Bufcalls related variables. 193 */ 194 struct bclist strbcalls; /* list of waiting bufcalls */ 195 kmutex_t strbcall_lock; /* protects bufcall list (strbcalls) */ 196 kcondvar_t strbcall_cv; /* Signaling when a bufcall is added */ 197 kmutex_t bcall_monitor; /* sleep/wakeup style monitor */ 198 kcondvar_t bcall_cv; /* wait 'till executing bufcall completes */ 199 kthread_t *bc_bkgrnd_thread; /* Thread to service bufcall requests */ 200 201 kmutex_t strresources; /* protects global resources */ 202 kmutex_t muxifier; /* single-threads multiplexor creation */ 203 204 static void *str_stack_init(netstackid_t stackid, netstack_t *ns); 205 static void str_stack_shutdown(netstackid_t stackid, void *arg); 206 static void str_stack_fini(netstackid_t stackid, void *arg); 207 208 /* 209 * run_queues is no longer used, but is kept in case some 3rd party 210 * module/driver decides to use it. 211 */ 212 int run_queues = 0; 213 214 /* 215 * sq_max_size is the depth of the syncq (in number of messages) before 216 * qfill_syncq() starts QFULL'ing destination queues. As its primary 217 * consumer - IP is no longer D_MTPERMOD, but there may be other 218 * modules/drivers depend on this syncq flow control, we prefer to 219 * choose a large number as the default value. For potential 220 * performance gain, this value is tunable in /etc/system. 221 */ 222 int sq_max_size = 10000; 223 224 /* 225 * The number of ciputctrl structures per syncq and stream we create when 226 * needed. 227 */ 228 int n_ciputctrl; 229 int max_n_ciputctrl = 16; 230 /* 231 * If n_ciputctrl is < min_n_ciputctrl don't even create ciputctrl_cache. 232 */ 233 int min_n_ciputctrl = 2; 234 235 /* 236 * Per-driver/module syncqs 237 * ======================== 238 * 239 * For drivers/modules that use PERMOD or outer syncqs we keep a list of 240 * perdm structures, new entries being added (and new syncqs allocated) when 241 * setq() encounters a module/driver with a streamtab that it hasn't seen 242 * before. 243 * The reason for this mechanism is that some modules and drivers share a 244 * common streamtab and it is necessary for those modules and drivers to also 245 * share a common PERMOD syncq. 246 * 247 * perdm_list --> dm_str == streamtab_1 248 * dm_sq == syncq_1 249 * dm_ref 250 * dm_next --> dm_str == streamtab_2 251 * dm_sq == syncq_2 252 * dm_ref 253 * dm_next --> ... NULL 254 * 255 * The dm_ref field is incremented for each new driver/module that takes 256 * a reference to the perdm structure and hence shares the syncq. 257 * References are held in the fmodsw_impl_t structure for each STREAMS module 258 * or the dev_impl array (indexed by device major number) for each driver. 259 * 260 * perdm_list -> [dm_ref == 1] -> [dm_ref == 2] -> [dm_ref == 1] -> NULL 261 * ^ ^ ^ ^ 262 * | ______________/ | | 263 * | / | | 264 * dev_impl: ...|x|y|... module A module B 265 * 266 * When a module/driver is unloaded the reference count is decremented and, 267 * when it falls to zero, the perdm structure is removed from the list and 268 * the syncq is freed (see rele_dm()). 269 */ 270 perdm_t *perdm_list = NULL; 271 static krwlock_t perdm_rwlock; 272 cdevsw_impl_t *devimpl; 273 274 extern struct qinit strdata; 275 extern struct qinit stwdata; 276 277 static void runservice(queue_t *); 278 static void streams_bufcall_service(void); 279 static void streams_qbkgrnd_service(void); 280 static void streams_sqbkgrnd_service(void); 281 static syncq_t *new_syncq(void); 282 static void free_syncq(syncq_t *); 283 static void outer_insert(syncq_t *, syncq_t *); 284 static void outer_remove(syncq_t *, syncq_t *); 285 static void write_now(syncq_t *); 286 static void clr_qfull(queue_t *); 287 static void runbufcalls(void); 288 static void sqenable(syncq_t *); 289 static void sqfill_events(syncq_t *, queue_t *, mblk_t *, void (*)()); 290 static void wait_q_syncq(queue_t *); 291 static void backenable_insertedq(queue_t *); 292 293 static void queue_service(queue_t *); 294 static void stream_service(stdata_t *); 295 static void syncq_service(syncq_t *); 296 static void qwriter_outer_service(syncq_t *); 297 static void mblk_free(mblk_t *); 298 #ifdef DEBUG 299 static int qprocsareon(queue_t *); 300 #endif 301 302 static void set_nfsrv_ptr(queue_t *, queue_t *, queue_t *, queue_t *); 303 static void reset_nfsrv_ptr(queue_t *, queue_t *); 304 void set_qfull(queue_t *); 305 306 static void sq_run_events(syncq_t *); 307 static int propagate_syncq(queue_t *); 308 309 static void blocksq(syncq_t *, ushort_t, int); 310 static void unblocksq(syncq_t *, ushort_t, int); 311 static int dropsq(syncq_t *, uint16_t); 312 static void emptysq(syncq_t *); 313 static sqlist_t *sqlist_alloc(struct stdata *, int); 314 static void sqlist_free(sqlist_t *); 315 static sqlist_t *sqlist_build(queue_t *, struct stdata *, boolean_t); 316 static void sqlist_insert(sqlist_t *, syncq_t *); 317 static void sqlist_insertall(sqlist_t *, queue_t *); 318 319 static void strsetuio(stdata_t *); 320 321 struct kmem_cache *stream_head_cache; 322 struct kmem_cache *queue_cache; 323 struct kmem_cache *syncq_cache; 324 struct kmem_cache *qband_cache; 325 struct kmem_cache *linkinfo_cache; 326 struct kmem_cache *ciputctrl_cache = NULL; 327 328 static linkinfo_t *linkinfo_list; 329 330 /* Global esballoc throttling queue */ 331 static esb_queue_t system_esbq; 332 333 /* Array of esballoc throttling queues, of length esbq_nelem */ 334 static esb_queue_t *volatile system_esbq_array; 335 static int esbq_nelem; 336 static kmutex_t esbq_lock; 337 static int esbq_log2_cpus_per_q = 0; 338 339 /* Scale the system_esbq length by setting number of CPUs per queue. */ 340 uint_t esbq_cpus_per_q = 1; 341 342 /* 343 * esballoc tunable parameters. 344 */ 345 int esbq_max_qlen = 0x16; /* throttled queue length */ 346 clock_t esbq_timeout = 0x8; /* timeout to process esb queue */ 347 348 /* 349 * Routines to handle esballoc queueing. 350 */ 351 static void esballoc_process_queue(esb_queue_t *); 352 static void esballoc_enqueue_mblk(mblk_t *); 353 static void esballoc_timer(void *); 354 static void esballoc_set_timer(esb_queue_t *, clock_t); 355 static void esballoc_mblk_free(mblk_t *); 356 357 /* 358 * Qinit structure and Module_info structures 359 * for passthru read and write queues 360 */ 361 362 static void pass_wput(queue_t *, mblk_t *); 363 static queue_t *link_addpassthru(stdata_t *); 364 static void link_rempassthru(queue_t *); 365 366 struct module_info passthru_info = { 367 0, 368 "passthru", 369 0, 370 INFPSZ, 371 STRHIGH, 372 STRLOW 373 }; 374 375 struct qinit passthru_rinit = { 376 (int (*)())putnext, 377 NULL, 378 NULL, 379 NULL, 380 NULL, 381 &passthru_info, 382 NULL 383 }; 384 385 struct qinit passthru_winit = { 386 (int (*)()) pass_wput, 387 NULL, 388 NULL, 389 NULL, 390 NULL, 391 &passthru_info, 392 NULL 393 }; 394 395 /* 396 * Verify correctness of list head/tail pointers. 397 */ 398 #define LISTCHECK(head, tail, link) { \ 399 EQUIV(head, tail); \ 400 IMPLY(tail != NULL, tail->link == NULL); \ 401 } 402 403 /* 404 * Enqueue a list element `el' in the end of a list denoted by `head' and `tail' 405 * using a `link' field. 406 */ 407 #define ENQUEUE(el, head, tail, link) { \ 408 ASSERT(el->link == NULL); \ 409 LISTCHECK(head, tail, link); \ 410 if (head == NULL) \ 411 head = el; \ 412 else \ 413 tail->link = el; \ 414 tail = el; \ 415 } 416 417 /* 418 * Dequeue the first element of the list denoted by `head' and `tail' pointers 419 * using a `link' field and put result into `el'. 420 */ 421 #define DQ(el, head, tail, link) { \ 422 LISTCHECK(head, tail, link); \ 423 el = head; \ 424 if (head != NULL) { \ 425 head = head->link; \ 426 if (head == NULL) \ 427 tail = NULL; \ 428 el->link = NULL; \ 429 } \ 430 } 431 432 /* 433 * Remove `el' from the list using `chase' and `curr' pointers and return result 434 * in `succeed'. 435 */ 436 #define RMQ(el, head, tail, link, chase, curr, succeed) { \ 437 LISTCHECK(head, tail, link); \ 438 chase = NULL; \ 439 succeed = 0; \ 440 for (curr = head; (curr != el) && (curr != NULL); curr = curr->link) \ 441 chase = curr; \ 442 if (curr != NULL) { \ 443 succeed = 1; \ 444 ASSERT(curr == el); \ 445 if (chase != NULL) \ 446 chase->link = curr->link; \ 447 else \ 448 head = curr->link; \ 449 curr->link = NULL; \ 450 if (curr == tail) \ 451 tail = chase; \ 452 } \ 453 LISTCHECK(head, tail, link); \ 454 } 455 456 /* Handling of delayed messages on the inner syncq. */ 457 458 /* 459 * DEBUG versions should use function versions (to simplify tracing) and 460 * non-DEBUG kernels should use macro versions. 461 */ 462 463 /* 464 * Put a queue on the syncq list of queues. 465 * Assumes SQLOCK held. 466 */ 467 #define SQPUT_Q(sq, qp) \ 468 { \ 469 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 470 if (!(qp->q_sqflags & Q_SQQUEUED)) { \ 471 /* The queue should not be linked anywhere */ \ 472 ASSERT((qp->q_sqprev == NULL) && (qp->q_sqnext == NULL)); \ 473 /* Head and tail may only be NULL simultaneously */ \ 474 EQUIV(sq->sq_head, sq->sq_tail); \ 475 /* Queue may be only enqueued on its syncq */ \ 476 ASSERT(sq == qp->q_syncq); \ 477 /* Check the correctness of SQ_MESSAGES flag */ \ 478 EQUIV(sq->sq_head, (sq->sq_flags & SQ_MESSAGES)); \ 479 /* Sanity check first/last elements of the list */ \ 480 IMPLY(sq->sq_head != NULL, sq->sq_head->q_sqprev == NULL);\ 481 IMPLY(sq->sq_tail != NULL, sq->sq_tail->q_sqnext == NULL);\ 482 /* \ 483 * Sanity check of priority field: empty queue should \ 484 * have zero priority \ 485 * and nqueues equal to zero. \ 486 */ \ 487 IMPLY(sq->sq_head == NULL, sq->sq_pri == 0); \ 488 /* Sanity check of sq_nqueues field */ \ 489 EQUIV(sq->sq_head, sq->sq_nqueues); \ 490 if (sq->sq_head == NULL) { \ 491 sq->sq_head = sq->sq_tail = qp; \ 492 sq->sq_flags |= SQ_MESSAGES; \ 493 } else if (qp->q_spri == 0) { \ 494 qp->q_sqprev = sq->sq_tail; \ 495 sq->sq_tail->q_sqnext = qp; \ 496 sq->sq_tail = qp; \ 497 } else { \ 498 /* \ 499 * Put this queue in priority order: higher \ 500 * priority gets closer to the head. \ 501 */ \ 502 queue_t **qpp = &sq->sq_tail; \ 503 queue_t *qnext = NULL; \ 504 \ 505 while (*qpp != NULL && qp->q_spri > (*qpp)->q_spri) { \ 506 qnext = *qpp; \ 507 qpp = &(*qpp)->q_sqprev; \ 508 } \ 509 qp->q_sqnext = qnext; \ 510 qp->q_sqprev = *qpp; \ 511 if (*qpp != NULL) { \ 512 (*qpp)->q_sqnext = qp; \ 513 } else { \ 514 sq->sq_head = qp; \ 515 sq->sq_pri = sq->sq_head->q_spri; \ 516 } \ 517 *qpp = qp; \ 518 } \ 519 qp->q_sqflags |= Q_SQQUEUED; \ 520 qp->q_sqtstamp = ddi_get_lbolt(); \ 521 sq->sq_nqueues++; \ 522 } \ 523 } 524 525 /* 526 * Remove a queue from the syncq list 527 * Assumes SQLOCK held. 528 */ 529 #define SQRM_Q(sq, qp) \ 530 { \ 531 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 532 ASSERT(qp->q_sqflags & Q_SQQUEUED); \ 533 ASSERT(sq->sq_head != NULL && sq->sq_tail != NULL); \ 534 ASSERT((sq->sq_flags & SQ_MESSAGES) != 0); \ 535 /* Check that the queue is actually in the list */ \ 536 ASSERT(qp->q_sqnext != NULL || sq->sq_tail == qp); \ 537 ASSERT(qp->q_sqprev != NULL || sq->sq_head == qp); \ 538 ASSERT(sq->sq_nqueues != 0); \ 539 if (qp->q_sqprev == NULL) { \ 540 /* First queue on list, make head q_sqnext */ \ 541 sq->sq_head = qp->q_sqnext; \ 542 } else { \ 543 /* Make prev->next == next */ \ 544 qp->q_sqprev->q_sqnext = qp->q_sqnext; \ 545 } \ 546 if (qp->q_sqnext == NULL) { \ 547 /* Last queue on list, make tail sqprev */ \ 548 sq->sq_tail = qp->q_sqprev; \ 549 } else { \ 550 /* Make next->prev == prev */ \ 551 qp->q_sqnext->q_sqprev = qp->q_sqprev; \ 552 } \ 553 /* clear out references on this queue */ \ 554 qp->q_sqprev = qp->q_sqnext = NULL; \ 555 qp->q_sqflags &= ~Q_SQQUEUED; \ 556 /* If there is nothing queued, clear SQ_MESSAGES */ \ 557 if (sq->sq_head != NULL) { \ 558 sq->sq_pri = sq->sq_head->q_spri; \ 559 } else { \ 560 sq->sq_flags &= ~SQ_MESSAGES; \ 561 sq->sq_pri = 0; \ 562 } \ 563 sq->sq_nqueues--; \ 564 ASSERT(sq->sq_head != NULL || sq->sq_evhead != NULL || \ 565 (sq->sq_flags & SQ_QUEUED) == 0); \ 566 } 567 568 /* Hide the definition from the header file. */ 569 #ifdef SQPUT_MP 570 #undef SQPUT_MP 571 #endif 572 573 /* 574 * Put a message on the queue syncq. 575 * Assumes QLOCK held. 576 */ 577 #define SQPUT_MP(qp, mp) \ 578 { \ 579 ASSERT(MUTEX_HELD(QLOCK(qp))); \ 580 ASSERT(qp->q_sqhead == NULL || \ 581 (qp->q_sqtail != NULL && \ 582 qp->q_sqtail->b_next == NULL)); \ 583 qp->q_syncqmsgs++; \ 584 ASSERT(qp->q_syncqmsgs != 0); /* Wraparound */ \ 585 if (qp->q_sqhead == NULL) { \ 586 qp->q_sqhead = qp->q_sqtail = mp; \ 587 } else { \ 588 qp->q_sqtail->b_next = mp; \ 589 qp->q_sqtail = mp; \ 590 } \ 591 ASSERT(qp->q_syncqmsgs > 0); \ 592 set_qfull(qp); \ 593 } 594 595 #define SQ_PUTCOUNT_SETFAST_LOCKED(sq) { \ 596 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 597 if ((sq)->sq_ciputctrl != NULL) { \ 598 int i; \ 599 int nlocks = (sq)->sq_nciputctrl; \ 600 ciputctrl_t *cip = (sq)->sq_ciputctrl; \ 601 ASSERT((sq)->sq_type & SQ_CIPUT); \ 602 for (i = 0; i <= nlocks; i++) { \ 603 ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ 604 cip[i].ciputctrl_count |= SQ_FASTPUT; \ 605 } \ 606 } \ 607 } 608 609 610 #define SQ_PUTCOUNT_CLRFAST_LOCKED(sq) { \ 611 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 612 if ((sq)->sq_ciputctrl != NULL) { \ 613 int i; \ 614 int nlocks = (sq)->sq_nciputctrl; \ 615 ciputctrl_t *cip = (sq)->sq_ciputctrl; \ 616 ASSERT((sq)->sq_type & SQ_CIPUT); \ 617 for (i = 0; i <= nlocks; i++) { \ 618 ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ 619 cip[i].ciputctrl_count &= ~SQ_FASTPUT; \ 620 } \ 621 } \ 622 } 623 624 /* 625 * Run service procedures for all queues in the stream head. 626 */ 627 #define STR_SERVICE(stp, q) { \ 628 ASSERT(MUTEX_HELD(&stp->sd_qlock)); \ 629 while (stp->sd_qhead != NULL) { \ 630 DQ(q, stp->sd_qhead, stp->sd_qtail, q_link); \ 631 ASSERT(stp->sd_nqueues > 0); \ 632 stp->sd_nqueues--; \ 633 ASSERT(!(q->q_flag & QINSERVICE)); \ 634 mutex_exit(&stp->sd_qlock); \ 635 queue_service(q); \ 636 mutex_enter(&stp->sd_qlock); \ 637 } \ 638 ASSERT(stp->sd_nqueues == 0); \ 639 ASSERT((stp->sd_qhead == NULL) && (stp->sd_qtail == NULL)); \ 640 } 641 642 /* 643 * Constructor/destructor routines for the stream head cache 644 */ 645 /* ARGSUSED */ 646 static int 647 stream_head_constructor(void *buf, void *cdrarg, int kmflags) 648 { 649 stdata_t *stp = buf; 650 651 mutex_init(&stp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 652 mutex_init(&stp->sd_reflock, NULL, MUTEX_DEFAULT, NULL); 653 mutex_init(&stp->sd_qlock, NULL, MUTEX_DEFAULT, NULL); 654 mutex_init(&stp->sd_pid_list_lock, NULL, MUTEX_DEFAULT, NULL); 655 cv_init(&stp->sd_monitor, NULL, CV_DEFAULT, NULL); 656 cv_init(&stp->sd_iocmonitor, NULL, CV_DEFAULT, NULL); 657 cv_init(&stp->sd_refmonitor, NULL, CV_DEFAULT, NULL); 658 cv_init(&stp->sd_qcv, NULL, CV_DEFAULT, NULL); 659 cv_init(&stp->sd_zcopy_wait, NULL, CV_DEFAULT, NULL); 660 list_create(&stp->sd_pid_list, sizeof (pid_node_t), 661 offsetof(pid_node_t, pn_ref_link)); 662 stp->sd_wrq = NULL; 663 664 return (0); 665 } 666 667 /* ARGSUSED */ 668 static void 669 stream_head_destructor(void *buf, void *cdrarg) 670 { 671 stdata_t *stp = buf; 672 673 mutex_destroy(&stp->sd_lock); 674 mutex_destroy(&stp->sd_reflock); 675 mutex_destroy(&stp->sd_qlock); 676 mutex_destroy(&stp->sd_pid_list_lock); 677 cv_destroy(&stp->sd_monitor); 678 cv_destroy(&stp->sd_iocmonitor); 679 cv_destroy(&stp->sd_refmonitor); 680 cv_destroy(&stp->sd_qcv); 681 cv_destroy(&stp->sd_zcopy_wait); 682 list_destroy(&stp->sd_pid_list); 683 } 684 685 /* 686 * Constructor/destructor routines for the queue cache 687 */ 688 /* ARGSUSED */ 689 static int 690 queue_constructor(void *buf, void *cdrarg, int kmflags) 691 { 692 queinfo_t *qip = buf; 693 queue_t *qp = &qip->qu_rqueue; 694 queue_t *wqp = &qip->qu_wqueue; 695 syncq_t *sq = &qip->qu_syncq; 696 697 qp->q_first = NULL; 698 qp->q_link = NULL; 699 qp->q_count = 0; 700 qp->q_mblkcnt = 0; 701 qp->q_sqhead = NULL; 702 qp->q_sqtail = NULL; 703 qp->q_sqnext = NULL; 704 qp->q_sqprev = NULL; 705 qp->q_sqflags = 0; 706 qp->q_rwcnt = 0; 707 qp->q_spri = 0; 708 709 mutex_init(QLOCK(qp), NULL, MUTEX_DEFAULT, NULL); 710 cv_init(&qp->q_wait, NULL, CV_DEFAULT, NULL); 711 712 wqp->q_first = NULL; 713 wqp->q_link = NULL; 714 wqp->q_count = 0; 715 wqp->q_mblkcnt = 0; 716 wqp->q_sqhead = NULL; 717 wqp->q_sqtail = NULL; 718 wqp->q_sqnext = NULL; 719 wqp->q_sqprev = NULL; 720 wqp->q_sqflags = 0; 721 wqp->q_rwcnt = 0; 722 wqp->q_spri = 0; 723 724 mutex_init(QLOCK(wqp), NULL, MUTEX_DEFAULT, NULL); 725 cv_init(&wqp->q_wait, NULL, CV_DEFAULT, NULL); 726 727 sq->sq_head = NULL; 728 sq->sq_tail = NULL; 729 sq->sq_evhead = NULL; 730 sq->sq_evtail = NULL; 731 sq->sq_callbpend = NULL; 732 sq->sq_outer = NULL; 733 sq->sq_onext = NULL; 734 sq->sq_oprev = NULL; 735 sq->sq_next = NULL; 736 sq->sq_svcflags = 0; 737 sq->sq_servcount = 0; 738 sq->sq_needexcl = 0; 739 sq->sq_nqueues = 0; 740 sq->sq_pri = 0; 741 742 mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); 743 cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); 744 cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); 745 746 return (0); 747 } 748 749 /* ARGSUSED */ 750 static void 751 queue_destructor(void *buf, void *cdrarg) 752 { 753 queinfo_t *qip = buf; 754 queue_t *qp = &qip->qu_rqueue; 755 queue_t *wqp = &qip->qu_wqueue; 756 syncq_t *sq = &qip->qu_syncq; 757 758 ASSERT(qp->q_sqhead == NULL); 759 ASSERT(wqp->q_sqhead == NULL); 760 ASSERT(qp->q_sqnext == NULL); 761 ASSERT(wqp->q_sqnext == NULL); 762 ASSERT(qp->q_rwcnt == 0); 763 ASSERT(wqp->q_rwcnt == 0); 764 765 mutex_destroy(&qp->q_lock); 766 cv_destroy(&qp->q_wait); 767 768 mutex_destroy(&wqp->q_lock); 769 cv_destroy(&wqp->q_wait); 770 771 mutex_destroy(&sq->sq_lock); 772 cv_destroy(&sq->sq_wait); 773 cv_destroy(&sq->sq_exitwait); 774 } 775 776 /* 777 * Constructor/destructor routines for the syncq cache 778 */ 779 /* ARGSUSED */ 780 static int 781 syncq_constructor(void *buf, void *cdrarg, int kmflags) 782 { 783 syncq_t *sq = buf; 784 785 bzero(buf, sizeof (syncq_t)); 786 787 mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); 788 cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); 789 cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); 790 791 return (0); 792 } 793 794 /* ARGSUSED */ 795 static void 796 syncq_destructor(void *buf, void *cdrarg) 797 { 798 syncq_t *sq = buf; 799 800 ASSERT(sq->sq_head == NULL); 801 ASSERT(sq->sq_tail == NULL); 802 ASSERT(sq->sq_evhead == NULL); 803 ASSERT(sq->sq_evtail == NULL); 804 ASSERT(sq->sq_callbpend == NULL); 805 ASSERT(sq->sq_callbflags == 0); 806 ASSERT(sq->sq_outer == NULL); 807 ASSERT(sq->sq_onext == NULL); 808 ASSERT(sq->sq_oprev == NULL); 809 ASSERT(sq->sq_next == NULL); 810 ASSERT(sq->sq_needexcl == 0); 811 ASSERT(sq->sq_svcflags == 0); 812 ASSERT(sq->sq_servcount == 0); 813 ASSERT(sq->sq_nqueues == 0); 814 ASSERT(sq->sq_pri == 0); 815 ASSERT(sq->sq_count == 0); 816 ASSERT(sq->sq_rmqcount == 0); 817 ASSERT(sq->sq_cancelid == 0); 818 ASSERT(sq->sq_ciputctrl == NULL); 819 ASSERT(sq->sq_nciputctrl == 0); 820 ASSERT(sq->sq_type == 0); 821 ASSERT(sq->sq_flags == 0); 822 823 mutex_destroy(&sq->sq_lock); 824 cv_destroy(&sq->sq_wait); 825 cv_destroy(&sq->sq_exitwait); 826 } 827 828 /* ARGSUSED */ 829 static int 830 ciputctrl_constructor(void *buf, void *cdrarg, int kmflags) 831 { 832 ciputctrl_t *cip = buf; 833 int i; 834 835 for (i = 0; i < n_ciputctrl; i++) { 836 cip[i].ciputctrl_count = SQ_FASTPUT; 837 mutex_init(&cip[i].ciputctrl_lock, NULL, MUTEX_DEFAULT, NULL); 838 } 839 840 return (0); 841 } 842 843 /* ARGSUSED */ 844 static void 845 ciputctrl_destructor(void *buf, void *cdrarg) 846 { 847 ciputctrl_t *cip = buf; 848 int i; 849 850 for (i = 0; i < n_ciputctrl; i++) { 851 ASSERT(cip[i].ciputctrl_count & SQ_FASTPUT); 852 mutex_destroy(&cip[i].ciputctrl_lock); 853 } 854 } 855 856 /* 857 * Init routine run from main at boot time. 858 */ 859 void 860 strinit(void) 861 { 862 int ncpus = ((boot_max_ncpus == -1) ? max_ncpus : boot_max_ncpus); 863 864 stream_head_cache = kmem_cache_create("stream_head_cache", 865 sizeof (stdata_t), 0, 866 stream_head_constructor, stream_head_destructor, NULL, 867 NULL, NULL, 0); 868 869 queue_cache = kmem_cache_create("queue_cache", sizeof (queinfo_t), 0, 870 queue_constructor, queue_destructor, NULL, NULL, NULL, 0); 871 872 syncq_cache = kmem_cache_create("syncq_cache", sizeof (syncq_t), 0, 873 syncq_constructor, syncq_destructor, NULL, NULL, NULL, 0); 874 875 qband_cache = kmem_cache_create("qband_cache", 876 sizeof (qband_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 877 878 linkinfo_cache = kmem_cache_create("linkinfo_cache", 879 sizeof (linkinfo_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 880 881 n_ciputctrl = ncpus; 882 n_ciputctrl = 1 << highbit(n_ciputctrl - 1); 883 ASSERT(n_ciputctrl >= 1); 884 n_ciputctrl = MIN(n_ciputctrl, max_n_ciputctrl); 885 if (n_ciputctrl >= min_n_ciputctrl) { 886 ciputctrl_cache = kmem_cache_create("ciputctrl_cache", 887 sizeof (ciputctrl_t) * n_ciputctrl, 888 sizeof (ciputctrl_t), ciputctrl_constructor, 889 ciputctrl_destructor, NULL, NULL, NULL, 0); 890 } 891 892 streams_taskq = system_taskq; 893 894 if (streams_taskq == NULL) 895 panic("strinit: no memory for streams taskq!"); 896 897 bc_bkgrnd_thread = thread_create(NULL, 0, 898 streams_bufcall_service, NULL, 0, &p0, TS_RUN, streams_lopri); 899 900 streams_qbkgrnd_thread = thread_create(NULL, 0, 901 streams_qbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); 902 903 streams_sqbkgrnd_thread = thread_create(NULL, 0, 904 streams_sqbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); 905 906 /* 907 * Create STREAMS kstats. 908 */ 909 str_kstat = kstat_create("streams", 0, "strstat", 910 "net", KSTAT_TYPE_NAMED, 911 sizeof (str_statistics) / sizeof (kstat_named_t), 912 KSTAT_FLAG_VIRTUAL); 913 914 if (str_kstat != NULL) { 915 str_kstat->ks_data = &str_statistics; 916 kstat_install(str_kstat); 917 } 918 919 /* 920 * TPI support routine initialisation. 921 */ 922 tpi_init(); 923 924 /* 925 * Handle to have autopush and persistent link information per 926 * zone. 927 * Note: uses shutdown hook instead of destroy hook so that the 928 * persistent links can be torn down before the destroy hooks 929 * in the TCP/IP stack are called. 930 */ 931 netstack_register(NS_STR, str_stack_init, str_stack_shutdown, 932 str_stack_fini); 933 } 934 935 void 936 str_sendsig(vnode_t *vp, int event, uchar_t band, int error) 937 { 938 struct stdata *stp; 939 940 ASSERT(vp->v_stream); 941 stp = vp->v_stream; 942 /* Have to hold sd_lock to prevent siglist from changing */ 943 mutex_enter(&stp->sd_lock); 944 if (stp->sd_sigflags & event) 945 strsendsig(stp->sd_siglist, event, band, error); 946 mutex_exit(&stp->sd_lock); 947 } 948 949 /* 950 * Send the "sevent" set of signals to a process. 951 * This might send more than one signal if the process is registered 952 * for multiple events. The caller should pass in an sevent that only 953 * includes the events for which the process has registered. 954 */ 955 static void 956 dosendsig(proc_t *proc, int events, int sevent, k_siginfo_t *info, 957 uchar_t band, int error) 958 { 959 ASSERT(MUTEX_HELD(&proc->p_lock)); 960 961 info->si_band = 0; 962 info->si_errno = 0; 963 964 if (sevent & S_ERROR) { 965 sevent &= ~S_ERROR; 966 info->si_code = POLL_ERR; 967 info->si_errno = error; 968 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 969 "strsendsig:proc %p info %p", proc, info); 970 sigaddq(proc, NULL, info, KM_NOSLEEP); 971 info->si_errno = 0; 972 } 973 if (sevent & S_HANGUP) { 974 sevent &= ~S_HANGUP; 975 info->si_code = POLL_HUP; 976 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 977 "strsendsig:proc %p info %p", proc, info); 978 sigaddq(proc, NULL, info, KM_NOSLEEP); 979 } 980 if (sevent & S_HIPRI) { 981 sevent &= ~S_HIPRI; 982 info->si_code = POLL_PRI; 983 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 984 "strsendsig:proc %p info %p", proc, info); 985 sigaddq(proc, NULL, info, KM_NOSLEEP); 986 } 987 if (sevent & S_RDBAND) { 988 sevent &= ~S_RDBAND; 989 if (events & S_BANDURG) 990 sigtoproc(proc, NULL, SIGURG); 991 else 992 sigtoproc(proc, NULL, SIGPOLL); 993 } 994 if (sevent & S_WRBAND) { 995 sevent &= ~S_WRBAND; 996 sigtoproc(proc, NULL, SIGPOLL); 997 } 998 if (sevent & S_INPUT) { 999 sevent &= ~S_INPUT; 1000 info->si_code = POLL_IN; 1001 info->si_band = band; 1002 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1003 "strsendsig:proc %p info %p", proc, info); 1004 sigaddq(proc, NULL, info, KM_NOSLEEP); 1005 info->si_band = 0; 1006 } 1007 if (sevent & S_OUTPUT) { 1008 sevent &= ~S_OUTPUT; 1009 info->si_code = POLL_OUT; 1010 info->si_band = band; 1011 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1012 "strsendsig:proc %p info %p", proc, info); 1013 sigaddq(proc, NULL, info, KM_NOSLEEP); 1014 info->si_band = 0; 1015 } 1016 if (sevent & S_MSG) { 1017 sevent &= ~S_MSG; 1018 info->si_code = POLL_MSG; 1019 info->si_band = band; 1020 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1021 "strsendsig:proc %p info %p", proc, info); 1022 sigaddq(proc, NULL, info, KM_NOSLEEP); 1023 info->si_band = 0; 1024 } 1025 if (sevent & S_RDNORM) { 1026 sevent &= ~S_RDNORM; 1027 sigtoproc(proc, NULL, SIGPOLL); 1028 } 1029 if (sevent != 0) { 1030 panic("strsendsig: unknown event(s) %x", sevent); 1031 } 1032 } 1033 1034 /* 1035 * Send SIGPOLL/SIGURG signal to all processes and process groups 1036 * registered on the given signal list that want a signal for at 1037 * least one of the specified events. 1038 * 1039 * Must be called with exclusive access to siglist (caller holding sd_lock). 1040 * 1041 * strioctl(I_SETSIG/I_ESETSIG) will only change siglist when holding 1042 * sd_lock and the ioctl code maintains a PID_HOLD on the pid structure 1043 * while it is in the siglist. 1044 * 1045 * For performance reasons (MP scalability) the code drops pidlock 1046 * when sending signals to a single process. 1047 * When sending to a process group the code holds 1048 * pidlock to prevent the membership in the process group from changing 1049 * while walking the p_pglink list. 1050 */ 1051 void 1052 strsendsig(strsig_t *siglist, int event, uchar_t band, int error) 1053 { 1054 strsig_t *ssp; 1055 k_siginfo_t info; 1056 struct pid *pidp; 1057 proc_t *proc; 1058 1059 info.si_signo = SIGPOLL; 1060 info.si_errno = 0; 1061 for (ssp = siglist; ssp; ssp = ssp->ss_next) { 1062 int sevent; 1063 1064 sevent = ssp->ss_events & event; 1065 if (sevent == 0) 1066 continue; 1067 1068 if ((pidp = ssp->ss_pidp) == NULL) { 1069 /* pid was released but still on event list */ 1070 continue; 1071 } 1072 1073 1074 if (ssp->ss_pid > 0) { 1075 /* 1076 * XXX This unfortunately still generates 1077 * a signal when a fd is closed but 1078 * the proc is active. 1079 */ 1080 ASSERT(ssp->ss_pid == pidp->pid_id); 1081 1082 mutex_enter(&pidlock); 1083 proc = prfind_zone(pidp->pid_id, ALL_ZONES); 1084 if (proc == NULL) { 1085 mutex_exit(&pidlock); 1086 continue; 1087 } 1088 mutex_enter(&proc->p_lock); 1089 mutex_exit(&pidlock); 1090 dosendsig(proc, ssp->ss_events, sevent, &info, 1091 band, error); 1092 mutex_exit(&proc->p_lock); 1093 } else { 1094 /* 1095 * Send to process group. Hold pidlock across 1096 * calls to dosendsig(). 1097 */ 1098 pid_t pgrp = -ssp->ss_pid; 1099 1100 mutex_enter(&pidlock); 1101 proc = pgfind_zone(pgrp, ALL_ZONES); 1102 while (proc != NULL) { 1103 mutex_enter(&proc->p_lock); 1104 dosendsig(proc, ssp->ss_events, sevent, 1105 &info, band, error); 1106 mutex_exit(&proc->p_lock); 1107 proc = proc->p_pglink; 1108 } 1109 mutex_exit(&pidlock); 1110 } 1111 } 1112 } 1113 1114 /* 1115 * Attach a stream device or module. 1116 * qp is a read queue; the new queue goes in so its next 1117 * read ptr is the argument, and the write queue corresponding 1118 * to the argument points to this queue. Return 0 on success, 1119 * or a non-zero errno on failure. 1120 */ 1121 int 1122 qattach(queue_t *qp, dev_t *devp, int oflag, cred_t *crp, fmodsw_impl_t *fp, 1123 boolean_t is_insert) 1124 { 1125 major_t major; 1126 cdevsw_impl_t *dp; 1127 struct streamtab *str; 1128 queue_t *rq; 1129 queue_t *wrq; 1130 uint32_t qflag; 1131 uint32_t sqtype; 1132 perdm_t *dmp; 1133 int error; 1134 int sflag; 1135 1136 rq = allocq(); 1137 wrq = _WR(rq); 1138 STREAM(rq) = STREAM(wrq) = STREAM(qp); 1139 1140 if (fp != NULL) { 1141 str = fp->f_str; 1142 qflag = fp->f_qflag; 1143 sqtype = fp->f_sqtype; 1144 dmp = fp->f_dmp; 1145 IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); 1146 sflag = MODOPEN; 1147 1148 /* 1149 * stash away a pointer to the module structure so we can 1150 * unref it in qdetach. 1151 */ 1152 rq->q_fp = fp; 1153 } else { 1154 ASSERT(!is_insert); 1155 1156 major = getmajor(*devp); 1157 dp = &devimpl[major]; 1158 1159 str = dp->d_str; 1160 ASSERT(str == STREAMSTAB(major)); 1161 1162 qflag = dp->d_qflag; 1163 ASSERT(qflag & QISDRV); 1164 sqtype = dp->d_sqtype; 1165 1166 /* create perdm_t if needed */ 1167 if (NEED_DM(dp->d_dmp, qflag)) 1168 dp->d_dmp = hold_dm(str, qflag, sqtype); 1169 1170 dmp = dp->d_dmp; 1171 sflag = 0; 1172 } 1173 1174 TRACE_2(TR_FAC_STREAMS_FR, TR_QATTACH_FLAGS, 1175 "qattach:qflag == %X(%X)", qflag, *devp); 1176 1177 /* setq might sleep in allocator - avoid holding locks. */ 1178 setq(rq, str->st_rdinit, str->st_wrinit, dmp, qflag, sqtype, B_FALSE); 1179 1180 /* 1181 * Before calling the module's open routine, set up the q_next 1182 * pointer for inserting a module in the middle of a stream. 1183 * 1184 * Note that we can always set _QINSERTING and set up q_next 1185 * pointer for both inserting and pushing a module. Then there 1186 * is no need for the is_insert parameter. In insertq(), called 1187 * by qprocson(), assume that q_next of the new module always points 1188 * to the correct queue and use it for insertion. Everything should 1189 * work out fine. But in the first release of _I_INSERT, we 1190 * distinguish between inserting and pushing to make sure that 1191 * pushing a module follows the same code path as before. 1192 */ 1193 if (is_insert) { 1194 rq->q_flag |= _QINSERTING; 1195 rq->q_next = qp; 1196 } 1197 1198 /* 1199 * If there is an outer perimeter get exclusive access during 1200 * the open procedure. Bump up the reference count on the queue. 1201 */ 1202 entersq(rq->q_syncq, SQ_OPENCLOSE); 1203 error = (*rq->q_qinfo->qi_qopen)(rq, devp, oflag, sflag, crp); 1204 if (error != 0) 1205 goto failed; 1206 leavesq(rq->q_syncq, SQ_OPENCLOSE); 1207 ASSERT(qprocsareon(rq)); 1208 return (0); 1209 1210 failed: 1211 rq->q_flag &= ~_QINSERTING; 1212 if (backq(wrq) != NULL && backq(wrq)->q_next == wrq) 1213 qprocsoff(rq); 1214 leavesq(rq->q_syncq, SQ_OPENCLOSE); 1215 rq->q_next = wrq->q_next = NULL; 1216 qdetach(rq, 0, 0, crp, B_FALSE); 1217 return (error); 1218 } 1219 1220 /* 1221 * Handle second open of stream. For modules, set the 1222 * last argument to MODOPEN and do not pass any open flags. 1223 * Ignore dummydev since this is not the first open. 1224 */ 1225 int 1226 qreopen(queue_t *qp, dev_t *devp, int flag, cred_t *crp) 1227 { 1228 int error; 1229 dev_t dummydev; 1230 queue_t *wqp = _WR(qp); 1231 1232 ASSERT(qp->q_flag & QREADR); 1233 entersq(qp->q_syncq, SQ_OPENCLOSE); 1234 1235 dummydev = *devp; 1236 if (error = ((*qp->q_qinfo->qi_qopen)(qp, &dummydev, 1237 (wqp->q_next ? 0 : flag), (wqp->q_next ? MODOPEN : 0), crp))) { 1238 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1239 mutex_enter(&STREAM(qp)->sd_lock); 1240 qp->q_stream->sd_flag |= STREOPENFAIL; 1241 mutex_exit(&STREAM(qp)->sd_lock); 1242 return (error); 1243 } 1244 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1245 1246 /* 1247 * successful open should have done qprocson() 1248 */ 1249 ASSERT(qprocsareon(_RD(qp))); 1250 return (0); 1251 } 1252 1253 /* 1254 * Detach a stream module or device. 1255 * If clmode == 1 then the module or driver was opened and its 1256 * close routine must be called. If clmode == 0, the module 1257 * or driver was never opened or the open failed, and so its close 1258 * should not be called. 1259 */ 1260 void 1261 qdetach(queue_t *qp, int clmode, int flag, cred_t *crp, boolean_t is_remove) 1262 { 1263 queue_t *wqp = _WR(qp); 1264 ASSERT(STREAM(qp)->sd_flag & (STRCLOSE|STWOPEN|STRPLUMB)); 1265 1266 if (STREAM_NEEDSERVICE(STREAM(qp))) 1267 stream_runservice(STREAM(qp)); 1268 1269 if (clmode) { 1270 /* 1271 * Make sure that all the messages on the write side syncq are 1272 * processed and nothing is left. Since we are closing, no new 1273 * messages may appear there. 1274 */ 1275 wait_q_syncq(wqp); 1276 1277 entersq(qp->q_syncq, SQ_OPENCLOSE); 1278 if (is_remove) { 1279 mutex_enter(QLOCK(qp)); 1280 qp->q_flag |= _QREMOVING; 1281 mutex_exit(QLOCK(qp)); 1282 } 1283 (*qp->q_qinfo->qi_qclose)(qp, flag, crp); 1284 /* 1285 * Check that qprocsoff() was actually called. 1286 */ 1287 ASSERT((qp->q_flag & QWCLOSE) && (wqp->q_flag & QWCLOSE)); 1288 1289 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1290 } else { 1291 disable_svc(qp); 1292 } 1293 1294 /* 1295 * Allow any threads blocked in entersq to proceed and discover 1296 * the QWCLOSE is set. 1297 * Note: This assumes that all users of entersq check QWCLOSE. 1298 * Currently runservice is the only entersq that can happen 1299 * after removeq has finished. 1300 * Removeq will have discarded all messages destined to the closing 1301 * pair of queues from the syncq. 1302 * NOTE: Calling a function inside an assert is unconventional. 1303 * However, it does not cause any problem since flush_syncq() does 1304 * not change any state except when it returns non-zero i.e. 1305 * when the assert will trigger. 1306 */ 1307 ASSERT(flush_syncq(qp->q_syncq, qp) == 0); 1308 ASSERT(flush_syncq(wqp->q_syncq, wqp) == 0); 1309 ASSERT((qp->q_flag & QPERMOD) || 1310 ((qp->q_syncq->sq_head == NULL) && 1311 (wqp->q_syncq->sq_head == NULL))); 1312 1313 /* release any fmodsw_impl_t structure held on behalf of the queue */ 1314 ASSERT(qp->q_fp != NULL || qp->q_flag & QISDRV); 1315 if (qp->q_fp != NULL) 1316 fmodsw_rele(qp->q_fp); 1317 1318 /* freeq removes us from the outer perimeter if any */ 1319 freeq(qp); 1320 } 1321 1322 /* Prevent service procedures from being called */ 1323 void 1324 disable_svc(queue_t *qp) 1325 { 1326 queue_t *wqp = _WR(qp); 1327 1328 ASSERT(qp->q_flag & QREADR); 1329 mutex_enter(QLOCK(qp)); 1330 qp->q_flag |= QWCLOSE; 1331 mutex_exit(QLOCK(qp)); 1332 mutex_enter(QLOCK(wqp)); 1333 wqp->q_flag |= QWCLOSE; 1334 mutex_exit(QLOCK(wqp)); 1335 } 1336 1337 /* Allow service procedures to be called again */ 1338 void 1339 enable_svc(queue_t *qp) 1340 { 1341 queue_t *wqp = _WR(qp); 1342 1343 ASSERT(qp->q_flag & QREADR); 1344 mutex_enter(QLOCK(qp)); 1345 qp->q_flag &= ~QWCLOSE; 1346 mutex_exit(QLOCK(qp)); 1347 mutex_enter(QLOCK(wqp)); 1348 wqp->q_flag &= ~QWCLOSE; 1349 mutex_exit(QLOCK(wqp)); 1350 } 1351 1352 /* 1353 * Remove queue from qhead/qtail if it is enabled. 1354 * Only reset QENAB if the queue was removed from the runlist. 1355 * A queue goes through 3 stages: 1356 * It is on the service list and QENAB is set. 1357 * It is removed from the service list but QENAB is still set. 1358 * QENAB gets changed to QINSERVICE. 1359 * QINSERVICE is reset (when the service procedure is done) 1360 * Thus we can not reset QENAB unless we actually removed it from the service 1361 * queue. 1362 */ 1363 void 1364 remove_runlist(queue_t *qp) 1365 { 1366 if (qp->q_flag & QENAB && qhead != NULL) { 1367 queue_t *q_chase; 1368 queue_t *q_curr; 1369 int removed; 1370 1371 mutex_enter(&service_queue); 1372 RMQ(qp, qhead, qtail, q_link, q_chase, q_curr, removed); 1373 mutex_exit(&service_queue); 1374 if (removed) { 1375 STRSTAT(qremoved); 1376 qp->q_flag &= ~QENAB; 1377 } 1378 } 1379 } 1380 1381 1382 /* 1383 * Wait for any pending service processing to complete. 1384 * The removal of queues from the runlist is not atomic with the 1385 * clearing of the QENABLED flag and setting the INSERVICE flag. 1386 * consequently it is possible for remove_runlist in strclose 1387 * to not find the queue on the runlist but for it to be QENABLED 1388 * and not yet INSERVICE -> hence wait_svc needs to check QENABLED 1389 * as well as INSERVICE. 1390 */ 1391 void 1392 wait_svc(queue_t *qp) 1393 { 1394 queue_t *wqp = _WR(qp); 1395 1396 ASSERT(qp->q_flag & QREADR); 1397 1398 /* 1399 * Try to remove queues from qhead/qtail list. 1400 */ 1401 if (qhead != NULL) { 1402 remove_runlist(qp); 1403 remove_runlist(wqp); 1404 } 1405 /* 1406 * Wait till the syncqs associated with the queue disappear from the 1407 * background processing list. 1408 * This only needs to be done for non-PERMOD perimeters since 1409 * for PERMOD perimeters the syncq may be shared and will only be freed 1410 * when the last module/driver is unloaded. 1411 * If for PERMOD perimeters queue was on the syncq list, removeq() 1412 * should call propagate_syncq() or drain_syncq() for it. Both of these 1413 * functions remove the queue from its syncq list, so sqthread will not 1414 * try to access the queue. 1415 */ 1416 if (!(qp->q_flag & QPERMOD)) { 1417 syncq_t *rsq = qp->q_syncq; 1418 syncq_t *wsq = wqp->q_syncq; 1419 1420 /* 1421 * Disable rsq and wsq and wait for any background processing of 1422 * syncq to complete. 1423 */ 1424 wait_sq_svc(rsq); 1425 if (wsq != rsq) 1426 wait_sq_svc(wsq); 1427 } 1428 1429 mutex_enter(QLOCK(qp)); 1430 while (qp->q_flag & (QINSERVICE|QENAB)) 1431 cv_wait(&qp->q_wait, QLOCK(qp)); 1432 mutex_exit(QLOCK(qp)); 1433 mutex_enter(QLOCK(wqp)); 1434 while (wqp->q_flag & (QINSERVICE|QENAB)) 1435 cv_wait(&wqp->q_wait, QLOCK(wqp)); 1436 mutex_exit(QLOCK(wqp)); 1437 } 1438 1439 /* 1440 * Put ioctl data from userland buffer `arg' into the mblk chain `bp'. 1441 * `flag' must always contain either K_TO_K or U_TO_K; STR_NOSIG may 1442 * also be set, and is passed through to allocb_cred_wait(). 1443 * 1444 * Returns errno on failure, zero on success. 1445 */ 1446 int 1447 putiocd(mblk_t *bp, char *arg, int flag, cred_t *cr) 1448 { 1449 mblk_t *tmp; 1450 ssize_t count; 1451 int error = 0; 1452 1453 ASSERT((flag & (U_TO_K | K_TO_K)) == U_TO_K || 1454 (flag & (U_TO_K | K_TO_K)) == K_TO_K); 1455 1456 if (bp->b_datap->db_type == M_IOCTL) { 1457 count = ((struct iocblk *)bp->b_rptr)->ioc_count; 1458 } else { 1459 ASSERT(bp->b_datap->db_type == M_COPYIN); 1460 count = ((struct copyreq *)bp->b_rptr)->cq_size; 1461 } 1462 /* 1463 * strdoioctl validates ioc_count, so if this assert fails it 1464 * cannot be due to user error. 1465 */ 1466 ASSERT(count >= 0); 1467 1468 if ((tmp = allocb_cred_wait(count, (flag & STR_NOSIG), &error, cr, 1469 curproc->p_pid)) == NULL) { 1470 return (error); 1471 } 1472 error = strcopyin(arg, tmp->b_wptr, count, flag & (U_TO_K|K_TO_K)); 1473 if (error != 0) { 1474 freeb(tmp); 1475 return (error); 1476 } 1477 DB_CPID(tmp) = curproc->p_pid; 1478 tmp->b_wptr += count; 1479 bp->b_cont = tmp; 1480 1481 return (0); 1482 } 1483 1484 /* 1485 * Copy ioctl data to user-land. Return non-zero errno on failure, 1486 * 0 for success. 1487 */ 1488 int 1489 getiocd(mblk_t *bp, char *arg, int copymode) 1490 { 1491 ssize_t count; 1492 size_t n; 1493 int error; 1494 1495 if (bp->b_datap->db_type == M_IOCACK) 1496 count = ((struct iocblk *)bp->b_rptr)->ioc_count; 1497 else { 1498 ASSERT(bp->b_datap->db_type == M_COPYOUT); 1499 count = ((struct copyreq *)bp->b_rptr)->cq_size; 1500 } 1501 ASSERT(count >= 0); 1502 1503 for (bp = bp->b_cont; bp && count; 1504 count -= n, bp = bp->b_cont, arg += n) { 1505 n = MIN(count, bp->b_wptr - bp->b_rptr); 1506 error = strcopyout(bp->b_rptr, arg, n, copymode); 1507 if (error) 1508 return (error); 1509 } 1510 ASSERT(count == 0); 1511 return (0); 1512 } 1513 1514 /* 1515 * Allocate a linkinfo entry given the write queue of the 1516 * bottom module of the top stream and the write queue of the 1517 * stream head of the bottom stream. 1518 */ 1519 linkinfo_t * 1520 alloclink(queue_t *qup, queue_t *qdown, file_t *fpdown) 1521 { 1522 linkinfo_t *linkp; 1523 1524 linkp = kmem_cache_alloc(linkinfo_cache, KM_SLEEP); 1525 1526 linkp->li_lblk.l_qtop = qup; 1527 linkp->li_lblk.l_qbot = qdown; 1528 linkp->li_fpdown = fpdown; 1529 1530 mutex_enter(&strresources); 1531 linkp->li_next = linkinfo_list; 1532 linkp->li_prev = NULL; 1533 if (linkp->li_next) 1534 linkp->li_next->li_prev = linkp; 1535 linkinfo_list = linkp; 1536 linkp->li_lblk.l_index = ++lnk_id; 1537 ASSERT(lnk_id != 0); /* this should never wrap in practice */ 1538 mutex_exit(&strresources); 1539 1540 return (linkp); 1541 } 1542 1543 /* 1544 * Free a linkinfo entry. 1545 */ 1546 void 1547 lbfree(linkinfo_t *linkp) 1548 { 1549 mutex_enter(&strresources); 1550 if (linkp->li_next) 1551 linkp->li_next->li_prev = linkp->li_prev; 1552 if (linkp->li_prev) 1553 linkp->li_prev->li_next = linkp->li_next; 1554 else 1555 linkinfo_list = linkp->li_next; 1556 mutex_exit(&strresources); 1557 1558 kmem_cache_free(linkinfo_cache, linkp); 1559 } 1560 1561 /* 1562 * Check for a potential linking cycle. 1563 * Return 1 if a link will result in a cycle, 1564 * and 0 otherwise. 1565 */ 1566 int 1567 linkcycle(stdata_t *upstp, stdata_t *lostp, str_stack_t *ss) 1568 { 1569 struct mux_node *np; 1570 struct mux_edge *ep; 1571 int i; 1572 major_t lomaj; 1573 major_t upmaj; 1574 /* 1575 * if the lower stream is a pipe/FIFO, return, since link 1576 * cycles can not happen on pipes/FIFOs 1577 */ 1578 if (lostp->sd_vnode->v_type == VFIFO) 1579 return (0); 1580 1581 for (i = 0; i < ss->ss_devcnt; i++) { 1582 np = &ss->ss_mux_nodes[i]; 1583 MUX_CLEAR(np); 1584 } 1585 lomaj = getmajor(lostp->sd_vnode->v_rdev); 1586 upmaj = getmajor(upstp->sd_vnode->v_rdev); 1587 np = &ss->ss_mux_nodes[lomaj]; 1588 for (;;) { 1589 if (!MUX_DIDVISIT(np)) { 1590 if (np->mn_imaj == upmaj) 1591 return (1); 1592 if (np->mn_outp == NULL) { 1593 MUX_VISIT(np); 1594 if (np->mn_originp == NULL) 1595 return (0); 1596 np = np->mn_originp; 1597 continue; 1598 } 1599 MUX_VISIT(np); 1600 np->mn_startp = np->mn_outp; 1601 } else { 1602 if (np->mn_startp == NULL) { 1603 if (np->mn_originp == NULL) 1604 return (0); 1605 else { 1606 np = np->mn_originp; 1607 continue; 1608 } 1609 } 1610 /* 1611 * If ep->me_nodep is a FIFO (me_nodep == NULL), 1612 * ignore the edge and move on. ep->me_nodep gets 1613 * set to NULL in mux_addedge() if it is a FIFO. 1614 * 1615 */ 1616 ep = np->mn_startp; 1617 np->mn_startp = ep->me_nextp; 1618 if (ep->me_nodep == NULL) 1619 continue; 1620 ep->me_nodep->mn_originp = np; 1621 np = ep->me_nodep; 1622 } 1623 } 1624 } 1625 1626 /* 1627 * Find linkinfo entry corresponding to the parameters. 1628 */ 1629 linkinfo_t * 1630 findlinks(stdata_t *stp, int index, int type, str_stack_t *ss) 1631 { 1632 linkinfo_t *linkp; 1633 struct mux_edge *mep; 1634 struct mux_node *mnp; 1635 queue_t *qup; 1636 1637 mutex_enter(&strresources); 1638 if ((type & LINKTYPEMASK) == LINKNORMAL) { 1639 qup = getendq(stp->sd_wrq); 1640 for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { 1641 if ((qup == linkp->li_lblk.l_qtop) && 1642 (!index || (index == linkp->li_lblk.l_index))) { 1643 mutex_exit(&strresources); 1644 return (linkp); 1645 } 1646 } 1647 } else { 1648 ASSERT((type & LINKTYPEMASK) == LINKPERSIST); 1649 mnp = &ss->ss_mux_nodes[getmajor(stp->sd_vnode->v_rdev)]; 1650 mep = mnp->mn_outp; 1651 while (mep) { 1652 if ((index == 0) || (index == mep->me_muxid)) 1653 break; 1654 mep = mep->me_nextp; 1655 } 1656 if (!mep) { 1657 mutex_exit(&strresources); 1658 return (NULL); 1659 } 1660 for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { 1661 if ((!linkp->li_lblk.l_qtop) && 1662 (mep->me_muxid == linkp->li_lblk.l_index)) { 1663 mutex_exit(&strresources); 1664 return (linkp); 1665 } 1666 } 1667 } 1668 mutex_exit(&strresources); 1669 return (NULL); 1670 } 1671 1672 /* 1673 * Given a queue ptr, follow the chain of q_next pointers until you reach the 1674 * last queue on the chain and return it. 1675 */ 1676 queue_t * 1677 getendq(queue_t *q) 1678 { 1679 ASSERT(q != NULL); 1680 while (_SAMESTR(q)) 1681 q = q->q_next; 1682 return (q); 1683 } 1684 1685 /* 1686 * Wait for the syncq count to drop to zero. 1687 * sq could be either outer or inner. 1688 */ 1689 1690 static void 1691 wait_syncq(syncq_t *sq) 1692 { 1693 uint16_t count; 1694 1695 mutex_enter(SQLOCK(sq)); 1696 count = sq->sq_count; 1697 SQ_PUTLOCKS_ENTER(sq); 1698 SUM_SQ_PUTCOUNTS(sq, count); 1699 while (count != 0) { 1700 sq->sq_flags |= SQ_WANTWAKEUP; 1701 SQ_PUTLOCKS_EXIT(sq); 1702 cv_wait(&sq->sq_wait, SQLOCK(sq)); 1703 count = sq->sq_count; 1704 SQ_PUTLOCKS_ENTER(sq); 1705 SUM_SQ_PUTCOUNTS(sq, count); 1706 } 1707 SQ_PUTLOCKS_EXIT(sq); 1708 mutex_exit(SQLOCK(sq)); 1709 } 1710 1711 /* 1712 * Wait while there are any messages for the queue in its syncq. 1713 */ 1714 static void 1715 wait_q_syncq(queue_t *q) 1716 { 1717 if ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { 1718 syncq_t *sq = q->q_syncq; 1719 1720 mutex_enter(SQLOCK(sq)); 1721 while ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { 1722 sq->sq_flags |= SQ_WANTWAKEUP; 1723 cv_wait(&sq->sq_wait, SQLOCK(sq)); 1724 } 1725 mutex_exit(SQLOCK(sq)); 1726 } 1727 } 1728 1729 1730 int 1731 mlink_file(vnode_t *vp, int cmd, struct file *fpdown, cred_t *crp, int *rvalp, 1732 int lhlink) 1733 { 1734 struct stdata *stp; 1735 struct strioctl strioc; 1736 struct linkinfo *linkp; 1737 struct stdata *stpdown; 1738 struct streamtab *str; 1739 queue_t *passq; 1740 syncq_t *passyncq; 1741 queue_t *rq; 1742 cdevsw_impl_t *dp; 1743 uint32_t qflag; 1744 uint32_t sqtype; 1745 perdm_t *dmp; 1746 int error = 0; 1747 netstack_t *ns; 1748 str_stack_t *ss; 1749 1750 stp = vp->v_stream; 1751 TRACE_1(TR_FAC_STREAMS_FR, 1752 TR_I_LINK, "I_LINK/I_PLINK:stp %p", stp); 1753 /* 1754 * Test for invalid upper stream 1755 */ 1756 if (stp->sd_flag & STRHUP) { 1757 return (ENXIO); 1758 } 1759 if (vp->v_type == VFIFO) { 1760 return (EINVAL); 1761 } 1762 if (stp->sd_strtab == NULL) { 1763 return (EINVAL); 1764 } 1765 if (!stp->sd_strtab->st_muxwinit) { 1766 return (EINVAL); 1767 } 1768 if (fpdown == NULL) { 1769 return (EBADF); 1770 } 1771 ns = netstack_find_by_cred(crp); 1772 ASSERT(ns != NULL); 1773 ss = ns->netstack_str; 1774 ASSERT(ss != NULL); 1775 1776 if (getmajor(stp->sd_vnode->v_rdev) >= ss->ss_devcnt) { 1777 netstack_rele(ss->ss_netstack); 1778 return (EINVAL); 1779 } 1780 mutex_enter(&muxifier); 1781 if (stp->sd_flag & STPLEX) { 1782 mutex_exit(&muxifier); 1783 netstack_rele(ss->ss_netstack); 1784 return (ENXIO); 1785 } 1786 1787 /* 1788 * Test for invalid lower stream. 1789 * The check for the v_type != VFIFO and having a major 1790 * number not >= devcnt is done to avoid problems with 1791 * adding mux_node entry past the end of mux_nodes[]. 1792 * For FIFO's we don't add an entry so this isn't a 1793 * problem. 1794 */ 1795 if (((stpdown = fpdown->f_vnode->v_stream) == NULL) || 1796 (stpdown == stp) || (stpdown->sd_flag & 1797 (STPLEX|STRHUP|STRDERR|STWRERR|IOCWAIT|STRPLUMB)) || 1798 ((stpdown->sd_vnode->v_type != VFIFO) && 1799 (getmajor(stpdown->sd_vnode->v_rdev) >= ss->ss_devcnt)) || 1800 linkcycle(stp, stpdown, ss)) { 1801 mutex_exit(&muxifier); 1802 netstack_rele(ss->ss_netstack); 1803 return (EINVAL); 1804 } 1805 TRACE_1(TR_FAC_STREAMS_FR, 1806 TR_STPDOWN, "stpdown:%p", stpdown); 1807 rq = getendq(stp->sd_wrq); 1808 if (cmd == I_PLINK) 1809 rq = NULL; 1810 1811 linkp = alloclink(rq, stpdown->sd_wrq, fpdown); 1812 1813 strioc.ic_cmd = cmd; 1814 strioc.ic_timout = INFTIM; 1815 strioc.ic_len = sizeof (struct linkblk); 1816 strioc.ic_dp = (char *)&linkp->li_lblk; 1817 1818 /* 1819 * STRPLUMB protects plumbing changes and should be set before 1820 * link_addpassthru()/link_rempassthru() are called, so it is set here 1821 * and cleared in the end of mlink when passthru queue is removed. 1822 * Setting of STRPLUMB prevents reopens of the stream while passthru 1823 * queue is in-place (it is not a proper module and doesn't have open 1824 * entry point). 1825 * 1826 * STPLEX prevents any threads from entering the stream from above. It 1827 * can't be set before the call to link_addpassthru() because putnext 1828 * from below may cause stream head I/O routines to be called and these 1829 * routines assert that STPLEX is not set. After link_addpassthru() 1830 * nothing may come from below since the pass queue syncq is blocked. 1831 * Note also that STPLEX should be cleared before the call to 1832 * link_rempassthru() since when messages start flowing to the stream 1833 * head (e.g. because of message propagation from the pass queue) stream 1834 * head I/O routines may be called with STPLEX flag set. 1835 * 1836 * When STPLEX is set, nothing may come into the stream from above and 1837 * it is safe to do a setq which will change stream head. So, the 1838 * correct sequence of actions is: 1839 * 1840 * 1) Set STRPLUMB 1841 * 2) Call link_addpassthru() 1842 * 3) Set STPLEX 1843 * 4) Call setq and update the stream state 1844 * 5) Clear STPLEX 1845 * 6) Call link_rempassthru() 1846 * 7) Clear STRPLUMB 1847 * 1848 * The same sequence applies to munlink() code. 1849 */ 1850 mutex_enter(&stpdown->sd_lock); 1851 stpdown->sd_flag |= STRPLUMB; 1852 mutex_exit(&stpdown->sd_lock); 1853 /* 1854 * Add passthru queue below lower mux. This will block 1855 * syncqs of lower muxs read queue during I_LINK/I_UNLINK. 1856 */ 1857 passq = link_addpassthru(stpdown); 1858 1859 mutex_enter(&stpdown->sd_lock); 1860 stpdown->sd_flag |= STPLEX; 1861 mutex_exit(&stpdown->sd_lock); 1862 1863 rq = _RD(stpdown->sd_wrq); 1864 /* 1865 * There may be messages in the streamhead's syncq due to messages 1866 * that arrived before link_addpassthru() was done. To avoid 1867 * background processing of the syncq happening simultaneous with 1868 * setq processing, we disable the streamhead syncq and wait until 1869 * existing background thread finishes working on it. 1870 */ 1871 wait_sq_svc(rq->q_syncq); 1872 passyncq = passq->q_syncq; 1873 if (!(passyncq->sq_flags & SQ_BLOCKED)) 1874 blocksq(passyncq, SQ_BLOCKED, 0); 1875 1876 ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); 1877 ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); 1878 rq->q_ptr = _WR(rq)->q_ptr = NULL; 1879 1880 /* setq might sleep in allocator - avoid holding locks. */ 1881 /* Note: we are holding muxifier here. */ 1882 1883 str = stp->sd_strtab; 1884 dp = &devimpl[getmajor(vp->v_rdev)]; 1885 ASSERT(dp->d_str == str); 1886 1887 qflag = dp->d_qflag; 1888 sqtype = dp->d_sqtype; 1889 1890 /* create perdm_t if needed */ 1891 if (NEED_DM(dp->d_dmp, qflag)) 1892 dp->d_dmp = hold_dm(str, qflag, sqtype); 1893 1894 dmp = dp->d_dmp; 1895 1896 setq(rq, str->st_muxrinit, str->st_muxwinit, dmp, qflag, sqtype, 1897 B_TRUE); 1898 1899 /* 1900 * XXX Remove any "odd" messages from the queue. 1901 * Keep only M_DATA, M_PROTO, M_PCPROTO. 1902 */ 1903 error = strdoioctl(stp, &strioc, FNATIVE, 1904 K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); 1905 if (error != 0) { 1906 lbfree(linkp); 1907 1908 if (!(passyncq->sq_flags & SQ_BLOCKED)) 1909 blocksq(passyncq, SQ_BLOCKED, 0); 1910 /* 1911 * Restore the stream head queue and then remove 1912 * the passq. Turn off STPLEX before we turn on 1913 * the stream by removing the passq. 1914 */ 1915 rq->q_ptr = _WR(rq)->q_ptr = stpdown; 1916 setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, 1917 B_TRUE); 1918 1919 mutex_enter(&stpdown->sd_lock); 1920 stpdown->sd_flag &= ~STPLEX; 1921 mutex_exit(&stpdown->sd_lock); 1922 1923 link_rempassthru(passq); 1924 1925 mutex_enter(&stpdown->sd_lock); 1926 stpdown->sd_flag &= ~STRPLUMB; 1927 /* Wakeup anyone waiting for STRPLUMB to clear. */ 1928 cv_broadcast(&stpdown->sd_monitor); 1929 mutex_exit(&stpdown->sd_lock); 1930 1931 mutex_exit(&muxifier); 1932 netstack_rele(ss->ss_netstack); 1933 return (error); 1934 } 1935 mutex_enter(&fpdown->f_tlock); 1936 fpdown->f_count++; 1937 mutex_exit(&fpdown->f_tlock); 1938 1939 /* 1940 * if we've made it here the linkage is all set up so we should also 1941 * set up the layered driver linkages 1942 */ 1943 1944 ASSERT((cmd == I_LINK) || (cmd == I_PLINK)); 1945 if (cmd == I_LINK) { 1946 ldi_mlink_fp(stp, fpdown, lhlink, LINKNORMAL); 1947 } else { 1948 ldi_mlink_fp(stp, fpdown, lhlink, LINKPERSIST); 1949 } 1950 1951 link_rempassthru(passq); 1952 1953 mux_addedge(stp, stpdown, linkp->li_lblk.l_index, ss); 1954 1955 /* 1956 * Mark the upper stream as having dependent links 1957 * so that strclose can clean it up. 1958 */ 1959 if (cmd == I_LINK) { 1960 mutex_enter(&stp->sd_lock); 1961 stp->sd_flag |= STRHASLINKS; 1962 mutex_exit(&stp->sd_lock); 1963 } 1964 /* 1965 * Wake up any other processes that may have been 1966 * waiting on the lower stream. These will all 1967 * error out. 1968 */ 1969 mutex_enter(&stpdown->sd_lock); 1970 /* The passthru module is removed so we may release STRPLUMB */ 1971 stpdown->sd_flag &= ~STRPLUMB; 1972 cv_broadcast(&rq->q_wait); 1973 cv_broadcast(&_WR(rq)->q_wait); 1974 cv_broadcast(&stpdown->sd_monitor); 1975 mutex_exit(&stpdown->sd_lock); 1976 mutex_exit(&muxifier); 1977 *rvalp = linkp->li_lblk.l_index; 1978 netstack_rele(ss->ss_netstack); 1979 return (0); 1980 } 1981 1982 int 1983 mlink(vnode_t *vp, int cmd, int arg, cred_t *crp, int *rvalp, int lhlink) 1984 { 1985 int ret; 1986 struct file *fpdown; 1987 1988 fpdown = getf(arg); 1989 ret = mlink_file(vp, cmd, fpdown, crp, rvalp, lhlink); 1990 if (fpdown != NULL) 1991 releasef(arg); 1992 return (ret); 1993 } 1994 1995 /* 1996 * Unlink a multiplexor link. Stp is the controlling stream for the 1997 * link, and linkp points to the link's entry in the linkinfo list. 1998 * The muxifier lock must be held on entry and is dropped on exit. 1999 * 2000 * NOTE : Currently it is assumed that mux would process all the messages 2001 * sitting on it's queue before ACKing the UNLINK. It is the responsibility 2002 * of the mux to handle all the messages that arrive before UNLINK. 2003 * If the mux has to send down messages on its lower stream before 2004 * ACKing I_UNLINK, then it *should* know to handle messages even 2005 * after the UNLINK is acked (actually it should be able to handle till we 2006 * re-block the read side of the pass queue here). If the mux does not 2007 * open up the lower stream, any messages that arrive during UNLINK 2008 * will be put in the stream head. In the case of lower stream opening 2009 * up, some messages might land in the stream head depending on when 2010 * the message arrived and when the read side of the pass queue was 2011 * re-blocked. 2012 */ 2013 int 2014 munlink(stdata_t *stp, linkinfo_t *linkp, int flag, cred_t *crp, int *rvalp, 2015 str_stack_t *ss) 2016 { 2017 struct strioctl strioc; 2018 struct stdata *stpdown; 2019 queue_t *rq, *wrq; 2020 queue_t *passq; 2021 syncq_t *passyncq; 2022 int error = 0; 2023 file_t *fpdown; 2024 2025 ASSERT(MUTEX_HELD(&muxifier)); 2026 2027 stpdown = linkp->li_fpdown->f_vnode->v_stream; 2028 2029 /* 2030 * See the comment in mlink() concerning STRPLUMB/STPLEX flags. 2031 */ 2032 mutex_enter(&stpdown->sd_lock); 2033 stpdown->sd_flag |= STRPLUMB; 2034 mutex_exit(&stpdown->sd_lock); 2035 2036 /* 2037 * Add passthru queue below lower mux. This will block 2038 * syncqs of lower muxs read queue during I_LINK/I_UNLINK. 2039 */ 2040 passq = link_addpassthru(stpdown); 2041 2042 if ((flag & LINKTYPEMASK) == LINKNORMAL) 2043 strioc.ic_cmd = I_UNLINK; 2044 else 2045 strioc.ic_cmd = I_PUNLINK; 2046 strioc.ic_timout = INFTIM; 2047 strioc.ic_len = sizeof (struct linkblk); 2048 strioc.ic_dp = (char *)&linkp->li_lblk; 2049 2050 error = strdoioctl(stp, &strioc, FNATIVE, 2051 K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); 2052 2053 /* 2054 * If there was an error and this is not called via strclose, 2055 * return to the user. Otherwise, pretend there was no error 2056 * and close the link. 2057 */ 2058 if (error) { 2059 if (flag & LINKCLOSE) { 2060 cmn_err(CE_WARN, "KERNEL: munlink: could not perform " 2061 "unlink ioctl, closing anyway (%d)\n", error); 2062 } else { 2063 link_rempassthru(passq); 2064 mutex_enter(&stpdown->sd_lock); 2065 stpdown->sd_flag &= ~STRPLUMB; 2066 cv_broadcast(&stpdown->sd_monitor); 2067 mutex_exit(&stpdown->sd_lock); 2068 mutex_exit(&muxifier); 2069 return (error); 2070 } 2071 } 2072 2073 mux_rmvedge(stp, linkp->li_lblk.l_index, ss); 2074 fpdown = linkp->li_fpdown; 2075 lbfree(linkp); 2076 2077 /* 2078 * We go ahead and drop muxifier here--it's a nasty global lock that 2079 * can slow others down. It's okay to since attempts to mlink() this 2080 * stream will be stopped because STPLEX is still set in the stdata 2081 * structure, and munlink() is stopped because mux_rmvedge() and 2082 * lbfree() have removed it from mux_nodes[] and linkinfo_list, 2083 * respectively. Note that we defer the closef() of fpdown until 2084 * after we drop muxifier since strclose() can call munlinkall(). 2085 */ 2086 mutex_exit(&muxifier); 2087 2088 wrq = stpdown->sd_wrq; 2089 rq = _RD(wrq); 2090 2091 /* 2092 * Get rid of outstanding service procedure runs, before we make 2093 * it a stream head, since a stream head doesn't have any service 2094 * procedure. 2095 */ 2096 disable_svc(rq); 2097 wait_svc(rq); 2098 2099 /* 2100 * Since we don't disable the syncq for QPERMOD, we wait for whatever 2101 * is queued up to be finished. mux should take care that nothing is 2102 * send down to this queue. We should do it now as we're going to block 2103 * passyncq if it was unblocked. 2104 */ 2105 if (wrq->q_flag & QPERMOD) { 2106 syncq_t *sq = wrq->q_syncq; 2107 2108 mutex_enter(SQLOCK(sq)); 2109 while (wrq->q_sqflags & Q_SQQUEUED) { 2110 sq->sq_flags |= SQ_WANTWAKEUP; 2111 cv_wait(&sq->sq_wait, SQLOCK(sq)); 2112 } 2113 mutex_exit(SQLOCK(sq)); 2114 } 2115 passyncq = passq->q_syncq; 2116 if (!(passyncq->sq_flags & SQ_BLOCKED)) { 2117 2118 syncq_t *sq, *outer; 2119 2120 /* 2121 * Messages could be flowing from underneath. We will 2122 * block the read side of the passq. This would be 2123 * sufficient for QPAIR and QPERQ muxes to ensure 2124 * that no data is flowing up into this queue 2125 * and hence no thread active in this instance of 2126 * lower mux. But for QPERMOD and QMTOUTPERIM there 2127 * could be messages on the inner and outer/inner 2128 * syncqs respectively. We will wait for them to drain. 2129 * Because passq is blocked messages end up in the syncq 2130 * And qfill_syncq could possibly end up setting QFULL 2131 * which will access the rq->q_flag. Hence, we have to 2132 * acquire the QLOCK in setq. 2133 * 2134 * XXX Messages can also flow from top into this 2135 * queue though the unlink is over (Ex. some instance 2136 * in putnext() called from top that has still not 2137 * accessed this queue. And also putq(lowerq) ?). 2138 * Solution : How about blocking the l_qtop queue ? 2139 * Do we really care about such pure D_MP muxes ? 2140 */ 2141 2142 blocksq(passyncq, SQ_BLOCKED, 0); 2143 2144 sq = rq->q_syncq; 2145 if ((outer = sq->sq_outer) != NULL) { 2146 2147 /* 2148 * We have to just wait for the outer sq_count 2149 * drop to zero. As this does not prevent new 2150 * messages to enter the outer perimeter, this 2151 * is subject to starvation. 2152 * 2153 * NOTE :Because of blocksq above, messages could 2154 * be in the inner syncq only because of some 2155 * thread holding the outer perimeter exclusively. 2156 * Hence it would be sufficient to wait for the 2157 * exclusive holder of the outer perimeter to drain 2158 * the inner and outer syncqs. But we will not depend 2159 * on this feature and hence check the inner syncqs 2160 * separately. 2161 */ 2162 wait_syncq(outer); 2163 } 2164 2165 2166 /* 2167 * There could be messages destined for 2168 * this queue. Let the exclusive holder 2169 * drain it. 2170 */ 2171 2172 wait_syncq(sq); 2173 ASSERT((rq->q_flag & QPERMOD) || 2174 ((rq->q_syncq->sq_head == NULL) && 2175 (_WR(rq)->q_syncq->sq_head == NULL))); 2176 } 2177 2178 /* 2179 * We haven't taken care of QPERMOD case yet. QPERMOD is a special 2180 * case as we don't disable its syncq or remove it off the syncq 2181 * service list. 2182 */ 2183 if (rq->q_flag & QPERMOD) { 2184 syncq_t *sq = rq->q_syncq; 2185 2186 mutex_enter(SQLOCK(sq)); 2187 while (rq->q_sqflags & Q_SQQUEUED) { 2188 sq->sq_flags |= SQ_WANTWAKEUP; 2189 cv_wait(&sq->sq_wait, SQLOCK(sq)); 2190 } 2191 mutex_exit(SQLOCK(sq)); 2192 } 2193 2194 /* 2195 * flush_syncq changes states only when there are some messages to 2196 * free, i.e. when it returns non-zero value to return. 2197 */ 2198 ASSERT(flush_syncq(rq->q_syncq, rq) == 0); 2199 ASSERT(flush_syncq(wrq->q_syncq, wrq) == 0); 2200 2201 /* 2202 * Nobody else should know about this queue now. 2203 * If the mux did not process the messages before 2204 * acking the I_UNLINK, free them now. 2205 */ 2206 2207 flushq(rq, FLUSHALL); 2208 flushq(_WR(rq), FLUSHALL); 2209 2210 /* 2211 * Convert the mux lower queue into a stream head queue. 2212 * Turn off STPLEX before we turn on the stream by removing the passq. 2213 */ 2214 rq->q_ptr = wrq->q_ptr = stpdown; 2215 setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_TRUE); 2216 2217 ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); 2218 ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); 2219 2220 enable_svc(rq); 2221 2222 /* 2223 * Now it is a proper stream, so STPLEX is cleared. But STRPLUMB still 2224 * needs to be set to prevent reopen() of the stream - such reopen may 2225 * try to call non-existent pass queue open routine and panic. 2226 */ 2227 mutex_enter(&stpdown->sd_lock); 2228 stpdown->sd_flag &= ~STPLEX; 2229 mutex_exit(&stpdown->sd_lock); 2230 2231 ASSERT(((flag & LINKTYPEMASK) == LINKNORMAL) || 2232 ((flag & LINKTYPEMASK) == LINKPERSIST)); 2233 2234 /* clean up the layered driver linkages */ 2235 if ((flag & LINKTYPEMASK) == LINKNORMAL) { 2236 ldi_munlink_fp(stp, fpdown, LINKNORMAL); 2237 } else { 2238 ldi_munlink_fp(stp, fpdown, LINKPERSIST); 2239 } 2240 2241 link_rempassthru(passq); 2242 2243 /* 2244 * Now all plumbing changes are finished and STRPLUMB is no 2245 * longer needed. 2246 */ 2247 mutex_enter(&stpdown->sd_lock); 2248 stpdown->sd_flag &= ~STRPLUMB; 2249 cv_broadcast(&stpdown->sd_monitor); 2250 mutex_exit(&stpdown->sd_lock); 2251 2252 (void) closef(fpdown); 2253 return (0); 2254 } 2255 2256 /* 2257 * Unlink all multiplexor links for which stp is the controlling stream. 2258 * Return 0, or a non-zero errno on failure. 2259 */ 2260 int 2261 munlinkall(stdata_t *stp, int flag, cred_t *crp, int *rvalp, str_stack_t *ss) 2262 { 2263 linkinfo_t *linkp; 2264 int error = 0; 2265 2266 mutex_enter(&muxifier); 2267 while (linkp = findlinks(stp, 0, flag, ss)) { 2268 /* 2269 * munlink() releases the muxifier lock. 2270 */ 2271 if (error = munlink(stp, linkp, flag, crp, rvalp, ss)) 2272 return (error); 2273 mutex_enter(&muxifier); 2274 } 2275 mutex_exit(&muxifier); 2276 return (0); 2277 } 2278 2279 /* 2280 * A multiplexor link has been made. Add an 2281 * edge to the directed graph. 2282 */ 2283 void 2284 mux_addedge(stdata_t *upstp, stdata_t *lostp, int muxid, str_stack_t *ss) 2285 { 2286 struct mux_node *np; 2287 struct mux_edge *ep; 2288 major_t upmaj; 2289 major_t lomaj; 2290 2291 upmaj = getmajor(upstp->sd_vnode->v_rdev); 2292 lomaj = getmajor(lostp->sd_vnode->v_rdev); 2293 np = &ss->ss_mux_nodes[upmaj]; 2294 if (np->mn_outp) { 2295 ep = np->mn_outp; 2296 while (ep->me_nextp) 2297 ep = ep->me_nextp; 2298 ep->me_nextp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); 2299 ep = ep->me_nextp; 2300 } else { 2301 np->mn_outp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); 2302 ep = np->mn_outp; 2303 } 2304 ep->me_nextp = NULL; 2305 ep->me_muxid = muxid; 2306 /* 2307 * Save the dev_t for the purposes of str_stack_shutdown. 2308 * str_stack_shutdown assumes that the device allows reopen, since 2309 * this dev_t is the one after any cloning by xx_open(). 2310 * Would prefer finding the dev_t from before any cloning, 2311 * but specfs doesn't retain that. 2312 */ 2313 ep->me_dev = upstp->sd_vnode->v_rdev; 2314 if (lostp->sd_vnode->v_type == VFIFO) 2315 ep->me_nodep = NULL; 2316 else 2317 ep->me_nodep = &ss->ss_mux_nodes[lomaj]; 2318 } 2319 2320 /* 2321 * A multiplexor link has been removed. Remove the 2322 * edge in the directed graph. 2323 */ 2324 void 2325 mux_rmvedge(stdata_t *upstp, int muxid, str_stack_t *ss) 2326 { 2327 struct mux_node *np; 2328 struct mux_edge *ep; 2329 struct mux_edge *pep = NULL; 2330 major_t upmaj; 2331 2332 upmaj = getmajor(upstp->sd_vnode->v_rdev); 2333 np = &ss->ss_mux_nodes[upmaj]; 2334 ASSERT(np->mn_outp != NULL); 2335 ep = np->mn_outp; 2336 while (ep) { 2337 if (ep->me_muxid == muxid) { 2338 if (pep) 2339 pep->me_nextp = ep->me_nextp; 2340 else 2341 np->mn_outp = ep->me_nextp; 2342 kmem_free(ep, sizeof (struct mux_edge)); 2343 return; 2344 } 2345 pep = ep; 2346 ep = ep->me_nextp; 2347 } 2348 ASSERT(0); /* should not reach here */ 2349 } 2350 2351 /* 2352 * Translate the device flags (from conf.h) to the corresponding 2353 * qflag and sq_flag (type) values. 2354 */ 2355 int 2356 devflg_to_qflag(struct streamtab *stp, uint32_t devflag, uint32_t *qflagp, 2357 uint32_t *sqtypep) 2358 { 2359 uint32_t qflag = 0; 2360 uint32_t sqtype = 0; 2361 2362 if (devflag & _D_OLD) 2363 goto bad; 2364 2365 /* Inner perimeter presence and scope */ 2366 switch (devflag & D_MTINNER_MASK) { 2367 case D_MP: 2368 qflag |= QMTSAFE; 2369 sqtype |= SQ_CI; 2370 break; 2371 case D_MTPERQ|D_MP: 2372 qflag |= QPERQ; 2373 break; 2374 case D_MTQPAIR|D_MP: 2375 qflag |= QPAIR; 2376 break; 2377 case D_MTPERMOD|D_MP: 2378 qflag |= QPERMOD; 2379 break; 2380 default: 2381 goto bad; 2382 } 2383 2384 /* Outer perimeter */ 2385 if (devflag & D_MTOUTPERIM) { 2386 switch (devflag & D_MTINNER_MASK) { 2387 case D_MP: 2388 case D_MTPERQ|D_MP: 2389 case D_MTQPAIR|D_MP: 2390 break; 2391 default: 2392 goto bad; 2393 } 2394 qflag |= QMTOUTPERIM; 2395 } 2396 2397 /* Inner perimeter modifiers */ 2398 if (devflag & D_MTINNER_MOD) { 2399 switch (devflag & D_MTINNER_MASK) { 2400 case D_MP: 2401 goto bad; 2402 default: 2403 break; 2404 } 2405 if (devflag & D_MTPUTSHARED) 2406 sqtype |= SQ_CIPUT; 2407 if (devflag & _D_MTOCSHARED) { 2408 /* 2409 * The code in putnext assumes that it has the 2410 * highest concurrency by not checking sq_count. 2411 * Thus _D_MTOCSHARED can only be supported when 2412 * D_MTPUTSHARED is set. 2413 */ 2414 if (!(devflag & D_MTPUTSHARED)) 2415 goto bad; 2416 sqtype |= SQ_CIOC; 2417 } 2418 if (devflag & _D_MTCBSHARED) { 2419 /* 2420 * The code in putnext assumes that it has the 2421 * highest concurrency by not checking sq_count. 2422 * Thus _D_MTCBSHARED can only be supported when 2423 * D_MTPUTSHARED is set. 2424 */ 2425 if (!(devflag & D_MTPUTSHARED)) 2426 goto bad; 2427 sqtype |= SQ_CICB; 2428 } 2429 if (devflag & _D_MTSVCSHARED) { 2430 /* 2431 * The code in putnext assumes that it has the 2432 * highest concurrency by not checking sq_count. 2433 * Thus _D_MTSVCSHARED can only be supported when 2434 * D_MTPUTSHARED is set. Also _D_MTSVCSHARED is 2435 * supported only for QPERMOD. 2436 */ 2437 if (!(devflag & D_MTPUTSHARED) || !(qflag & QPERMOD)) 2438 goto bad; 2439 sqtype |= SQ_CISVC; 2440 } 2441 } 2442 2443 /* Default outer perimeter concurrency */ 2444 sqtype |= SQ_CO; 2445 2446 /* Outer perimeter modifiers */ 2447 if (devflag & D_MTOCEXCL) { 2448 if (!(devflag & D_MTOUTPERIM)) { 2449 /* No outer perimeter */ 2450 goto bad; 2451 } 2452 sqtype &= ~SQ_COOC; 2453 } 2454 2455 /* Synchronous Streams extended qinit structure */ 2456 if (devflag & D_SYNCSTR) 2457 qflag |= QSYNCSTR; 2458 2459 /* 2460 * Private flag used by a transport module to indicate 2461 * to sockfs that it supports direct-access mode without 2462 * having to go through STREAMS. 2463 */ 2464 if (devflag & _D_DIRECT) { 2465 /* Reject unless the module is fully-MT (no perimeter) */ 2466 if ((qflag & QMT_TYPEMASK) != QMTSAFE) 2467 goto bad; 2468 qflag |= _QDIRECT; 2469 } 2470 2471 *qflagp = qflag; 2472 *sqtypep = sqtype; 2473 return (0); 2474 2475 bad: 2476 cmn_err(CE_WARN, 2477 "stropen: bad MT flags (0x%x) in driver '%s'", 2478 (int)(qflag & D_MTSAFETY_MASK), 2479 stp->st_rdinit->qi_minfo->mi_idname); 2480 2481 return (EINVAL); 2482 } 2483 2484 /* 2485 * Set the interface values for a pair of queues (qinit structure, 2486 * packet sizes, water marks). 2487 * setq assumes that the caller does not have a claim (entersq or claimq) 2488 * on the queue. 2489 */ 2490 void 2491 setq(queue_t *rq, struct qinit *rinit, struct qinit *winit, 2492 perdm_t *dmp, uint32_t qflag, uint32_t sqtype, boolean_t lock_needed) 2493 { 2494 queue_t *wq; 2495 syncq_t *sq, *outer; 2496 2497 ASSERT(rq->q_flag & QREADR); 2498 ASSERT((qflag & QMT_TYPEMASK) != 0); 2499 IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); 2500 2501 wq = _WR(rq); 2502 rq->q_qinfo = rinit; 2503 rq->q_hiwat = rinit->qi_minfo->mi_hiwat; 2504 rq->q_lowat = rinit->qi_minfo->mi_lowat; 2505 rq->q_minpsz = rinit->qi_minfo->mi_minpsz; 2506 rq->q_maxpsz = rinit->qi_minfo->mi_maxpsz; 2507 wq->q_qinfo = winit; 2508 wq->q_hiwat = winit->qi_minfo->mi_hiwat; 2509 wq->q_lowat = winit->qi_minfo->mi_lowat; 2510 wq->q_minpsz = winit->qi_minfo->mi_minpsz; 2511 wq->q_maxpsz = winit->qi_minfo->mi_maxpsz; 2512 2513 /* Remove old syncqs */ 2514 sq = rq->q_syncq; 2515 outer = sq->sq_outer; 2516 if (outer != NULL) { 2517 ASSERT(wq->q_syncq->sq_outer == outer); 2518 outer_remove(outer, rq->q_syncq); 2519 if (wq->q_syncq != rq->q_syncq) 2520 outer_remove(outer, wq->q_syncq); 2521 } 2522 ASSERT(sq->sq_outer == NULL); 2523 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 2524 2525 if (sq != SQ(rq)) { 2526 if (!(rq->q_flag & QPERMOD)) 2527 free_syncq(sq); 2528 if (wq->q_syncq == rq->q_syncq) 2529 wq->q_syncq = NULL; 2530 rq->q_syncq = NULL; 2531 } 2532 if (wq->q_syncq != NULL && wq->q_syncq != sq && 2533 wq->q_syncq != SQ(rq)) { 2534 free_syncq(wq->q_syncq); 2535 wq->q_syncq = NULL; 2536 } 2537 ASSERT(rq->q_syncq == NULL || (rq->q_syncq->sq_head == NULL && 2538 rq->q_syncq->sq_tail == NULL)); 2539 ASSERT(wq->q_syncq == NULL || (wq->q_syncq->sq_head == NULL && 2540 wq->q_syncq->sq_tail == NULL)); 2541 2542 if (!(rq->q_flag & QPERMOD) && 2543 rq->q_syncq != NULL && rq->q_syncq->sq_ciputctrl != NULL) { 2544 ASSERT(rq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); 2545 SUMCHECK_CIPUTCTRL_COUNTS(rq->q_syncq->sq_ciputctrl, 2546 rq->q_syncq->sq_nciputctrl, 0); 2547 ASSERT(ciputctrl_cache != NULL); 2548 kmem_cache_free(ciputctrl_cache, rq->q_syncq->sq_ciputctrl); 2549 rq->q_syncq->sq_ciputctrl = NULL; 2550 rq->q_syncq->sq_nciputctrl = 0; 2551 } 2552 2553 if (!(wq->q_flag & QPERMOD) && 2554 wq->q_syncq != NULL && wq->q_syncq->sq_ciputctrl != NULL) { 2555 ASSERT(wq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); 2556 SUMCHECK_CIPUTCTRL_COUNTS(wq->q_syncq->sq_ciputctrl, 2557 wq->q_syncq->sq_nciputctrl, 0); 2558 ASSERT(ciputctrl_cache != NULL); 2559 kmem_cache_free(ciputctrl_cache, wq->q_syncq->sq_ciputctrl); 2560 wq->q_syncq->sq_ciputctrl = NULL; 2561 wq->q_syncq->sq_nciputctrl = 0; 2562 } 2563 2564 sq = SQ(rq); 2565 ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); 2566 ASSERT(sq->sq_outer == NULL); 2567 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 2568 2569 /* 2570 * Create syncqs based on qflag and sqtype. Set the SQ_TYPES_IN_FLAGS 2571 * bits in sq_flag based on the sqtype. 2572 */ 2573 ASSERT((sq->sq_flags & ~SQ_TYPES_IN_FLAGS) == 0); 2574 2575 rq->q_syncq = wq->q_syncq = sq; 2576 sq->sq_type = sqtype; 2577 sq->sq_flags = (sqtype & SQ_TYPES_IN_FLAGS); 2578 2579 /* 2580 * We are making sq_svcflags zero, 2581 * resetting SQ_DISABLED in case it was set by 2582 * wait_svc() in the munlink path. 2583 * 2584 */ 2585 ASSERT((sq->sq_svcflags & SQ_SERVICE) == 0); 2586 sq->sq_svcflags = 0; 2587 2588 /* 2589 * We need to acquire the lock here for the mlink and munlink case, 2590 * where canputnext, backenable, etc can access the q_flag. 2591 */ 2592 if (lock_needed) { 2593 mutex_enter(QLOCK(rq)); 2594 rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2595 mutex_exit(QLOCK(rq)); 2596 mutex_enter(QLOCK(wq)); 2597 wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2598 mutex_exit(QLOCK(wq)); 2599 } else { 2600 rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2601 wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2602 } 2603 2604 if (qflag & QPERQ) { 2605 /* Allocate a separate syncq for the write side */ 2606 sq = new_syncq(); 2607 sq->sq_type = rq->q_syncq->sq_type; 2608 sq->sq_flags = rq->q_syncq->sq_flags; 2609 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 2610 sq->sq_oprev == NULL); 2611 wq->q_syncq = sq; 2612 } 2613 if (qflag & QPERMOD) { 2614 sq = dmp->dm_sq; 2615 2616 /* 2617 * Assert that we do have an inner perimeter syncq and that it 2618 * does not have an outer perimeter associated with it. 2619 */ 2620 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 2621 sq->sq_oprev == NULL); 2622 rq->q_syncq = wq->q_syncq = sq; 2623 } 2624 if (qflag & QMTOUTPERIM) { 2625 outer = dmp->dm_sq; 2626 2627 ASSERT(outer->sq_outer == NULL); 2628 outer_insert(outer, rq->q_syncq); 2629 if (wq->q_syncq != rq->q_syncq) 2630 outer_insert(outer, wq->q_syncq); 2631 } 2632 ASSERT((rq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == 2633 (rq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); 2634 ASSERT((wq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == 2635 (wq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); 2636 ASSERT((rq->q_flag & QMT_TYPEMASK) == (qflag & QMT_TYPEMASK)); 2637 2638 /* 2639 * Initialize struio() types. 2640 */ 2641 rq->q_struiot = 2642 (rq->q_flag & QSYNCSTR) ? rinit->qi_struiot : STRUIOT_NONE; 2643 wq->q_struiot = 2644 (wq->q_flag & QSYNCSTR) ? winit->qi_struiot : STRUIOT_NONE; 2645 } 2646 2647 perdm_t * 2648 hold_dm(struct streamtab *str, uint32_t qflag, uint32_t sqtype) 2649 { 2650 syncq_t *sq; 2651 perdm_t **pp; 2652 perdm_t *p; 2653 perdm_t *dmp; 2654 2655 ASSERT(str != NULL); 2656 ASSERT(qflag & (QPERMOD | QMTOUTPERIM)); 2657 2658 rw_enter(&perdm_rwlock, RW_READER); 2659 for (p = perdm_list; p != NULL; p = p->dm_next) { 2660 if (p->dm_str == str) { /* found one */ 2661 atomic_inc_32(&(p->dm_ref)); 2662 rw_exit(&perdm_rwlock); 2663 return (p); 2664 } 2665 } 2666 rw_exit(&perdm_rwlock); 2667 2668 sq = new_syncq(); 2669 if (qflag & QPERMOD) { 2670 sq->sq_type = sqtype | SQ_PERMOD; 2671 sq->sq_flags = sqtype & SQ_TYPES_IN_FLAGS; 2672 } else { 2673 ASSERT(qflag & QMTOUTPERIM); 2674 sq->sq_onext = sq->sq_oprev = sq; 2675 } 2676 2677 dmp = kmem_alloc(sizeof (perdm_t), KM_SLEEP); 2678 dmp->dm_sq = sq; 2679 dmp->dm_str = str; 2680 dmp->dm_ref = 1; 2681 dmp->dm_next = NULL; 2682 2683 rw_enter(&perdm_rwlock, RW_WRITER); 2684 for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) { 2685 if (p->dm_str == str) { /* already present */ 2686 p->dm_ref++; 2687 rw_exit(&perdm_rwlock); 2688 free_syncq(sq); 2689 kmem_free(dmp, sizeof (perdm_t)); 2690 return (p); 2691 } 2692 } 2693 2694 *pp = dmp; 2695 rw_exit(&perdm_rwlock); 2696 return (dmp); 2697 } 2698 2699 void 2700 rele_dm(perdm_t *dmp) 2701 { 2702 perdm_t **pp; 2703 perdm_t *p; 2704 2705 rw_enter(&perdm_rwlock, RW_WRITER); 2706 ASSERT(dmp->dm_ref > 0); 2707 2708 if (--dmp->dm_ref > 0) { 2709 rw_exit(&perdm_rwlock); 2710 return; 2711 } 2712 2713 for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) 2714 if (p == dmp) 2715 break; 2716 ASSERT(p == dmp); 2717 *pp = p->dm_next; 2718 rw_exit(&perdm_rwlock); 2719 2720 /* 2721 * Wait for any background processing that relies on the 2722 * syncq to complete before it is freed. 2723 */ 2724 wait_sq_svc(p->dm_sq); 2725 free_syncq(p->dm_sq); 2726 kmem_free(p, sizeof (perdm_t)); 2727 } 2728 2729 /* 2730 * Make a protocol message given control and data buffers. 2731 * n.b., this can block; be careful of what locks you hold when calling it. 2732 * 2733 * If sd_maxblk is less than *iosize this routine can fail part way through 2734 * (due to an allocation failure). In this case on return *iosize will contain 2735 * the amount that was consumed. Otherwise *iosize will not be modified 2736 * i.e. it will contain the amount that was consumed. 2737 */ 2738 int 2739 strmakemsg( 2740 struct strbuf *mctl, 2741 ssize_t *iosize, 2742 struct uio *uiop, 2743 stdata_t *stp, 2744 int32_t flag, 2745 mblk_t **mpp) 2746 { 2747 mblk_t *mpctl = NULL; 2748 mblk_t *mpdata = NULL; 2749 int error; 2750 2751 ASSERT(uiop != NULL); 2752 2753 *mpp = NULL; 2754 /* Create control part, if any */ 2755 if ((mctl != NULL) && (mctl->len >= 0)) { 2756 error = strmakectl(mctl, flag, uiop->uio_fmode, &mpctl); 2757 if (error) 2758 return (error); 2759 } 2760 /* Create data part, if any */ 2761 if (*iosize >= 0) { 2762 error = strmakedata(iosize, uiop, stp, flag, &mpdata); 2763 if (error) { 2764 freemsg(mpctl); 2765 return (error); 2766 } 2767 } 2768 if (mpctl != NULL) { 2769 if (mpdata != NULL) 2770 linkb(mpctl, mpdata); 2771 *mpp = mpctl; 2772 } else { 2773 *mpp = mpdata; 2774 } 2775 return (0); 2776 } 2777 2778 /* 2779 * Make the control part of a protocol message given a control buffer. 2780 * n.b., this can block; be careful of what locks you hold when calling it. 2781 */ 2782 int 2783 strmakectl( 2784 struct strbuf *mctl, 2785 int32_t flag, 2786 int32_t fflag, 2787 mblk_t **mpp) 2788 { 2789 mblk_t *bp = NULL; 2790 unsigned char msgtype; 2791 int error = 0; 2792 cred_t *cr = CRED(); 2793 2794 /* We do not support interrupt threads using the stream head to send */ 2795 ASSERT(cr != NULL); 2796 2797 *mpp = NULL; 2798 /* 2799 * Create control part of message, if any. 2800 */ 2801 if ((mctl != NULL) && (mctl->len >= 0)) { 2802 caddr_t base; 2803 int ctlcount; 2804 int allocsz; 2805 2806 if (flag & RS_HIPRI) 2807 msgtype = M_PCPROTO; 2808 else 2809 msgtype = M_PROTO; 2810 2811 ctlcount = mctl->len; 2812 base = mctl->buf; 2813 2814 /* 2815 * Give modules a better chance to reuse M_PROTO/M_PCPROTO 2816 * blocks by increasing the size to something more usable. 2817 */ 2818 allocsz = MAX(ctlcount, 64); 2819 2820 /* 2821 * Range checking has already been done; simply try 2822 * to allocate a message block for the ctl part. 2823 */ 2824 while ((bp = allocb_cred(allocsz, cr, 2825 curproc->p_pid)) == NULL) { 2826 if (fflag & (FNDELAY|FNONBLOCK)) 2827 return (EAGAIN); 2828 if (error = strwaitbuf(allocsz, BPRI_MED)) 2829 return (error); 2830 } 2831 2832 bp->b_datap->db_type = msgtype; 2833 if (copyin(base, bp->b_wptr, ctlcount)) { 2834 freeb(bp); 2835 return (EFAULT); 2836 } 2837 bp->b_wptr += ctlcount; 2838 } 2839 *mpp = bp; 2840 return (0); 2841 } 2842 2843 /* 2844 * Make a protocol message given data buffers. 2845 * n.b., this can block; be careful of what locks you hold when calling it. 2846 * 2847 * If sd_maxblk is less than *iosize this routine can fail part way through 2848 * (due to an allocation failure). In this case on return *iosize will contain 2849 * the amount that was consumed. Otherwise *iosize will not be modified 2850 * i.e. it will contain the amount that was consumed. 2851 */ 2852 int 2853 strmakedata( 2854 ssize_t *iosize, 2855 struct uio *uiop, 2856 stdata_t *stp, 2857 int32_t flag, 2858 mblk_t **mpp) 2859 { 2860 mblk_t *mp = NULL; 2861 mblk_t *bp; 2862 int wroff = (int)stp->sd_wroff; 2863 int tail_len = (int)stp->sd_tail; 2864 int extra = wroff + tail_len; 2865 int error = 0; 2866 ssize_t maxblk; 2867 ssize_t count = *iosize; 2868 cred_t *cr; 2869 2870 *mpp = NULL; 2871 if (count < 0) 2872 return (0); 2873 2874 /* We do not support interrupt threads using the stream head to send */ 2875 cr = CRED(); 2876 ASSERT(cr != NULL); 2877 2878 maxblk = stp->sd_maxblk; 2879 if (maxblk == INFPSZ) 2880 maxblk = count; 2881 2882 /* 2883 * Create data part of message, if any. 2884 */ 2885 do { 2886 ssize_t size; 2887 dblk_t *dp; 2888 2889 ASSERT(uiop); 2890 2891 size = MIN(count, maxblk); 2892 2893 while ((bp = allocb_cred(size + extra, cr, 2894 curproc->p_pid)) == NULL) { 2895 error = EAGAIN; 2896 if ((uiop->uio_fmode & (FNDELAY|FNONBLOCK)) || 2897 (error = strwaitbuf(size + extra, BPRI_MED)) != 0) { 2898 if (count == *iosize) { 2899 freemsg(mp); 2900 return (error); 2901 } else { 2902 *iosize -= count; 2903 *mpp = mp; 2904 return (0); 2905 } 2906 } 2907 } 2908 dp = bp->b_datap; 2909 dp->db_cpid = curproc->p_pid; 2910 ASSERT(wroff <= dp->db_lim - bp->b_wptr); 2911 bp->b_wptr = bp->b_rptr = bp->b_rptr + wroff; 2912 2913 if (flag & STRUIO_POSTPONE) { 2914 /* 2915 * Setup the stream uio portion of the 2916 * dblk for subsequent use by struioget(). 2917 */ 2918 dp->db_struioflag = STRUIO_SPEC; 2919 dp->db_cksumstart = 0; 2920 dp->db_cksumstuff = 0; 2921 dp->db_cksumend = size; 2922 *(long long *)dp->db_struioun.data = 0ll; 2923 bp->b_wptr += size; 2924 } else { 2925 if (stp->sd_copyflag & STRCOPYCACHED) 2926 uiop->uio_extflg |= UIO_COPY_CACHED; 2927 2928 if (size != 0) { 2929 error = uiomove(bp->b_wptr, size, UIO_WRITE, 2930 uiop); 2931 if (error != 0) { 2932 freeb(bp); 2933 freemsg(mp); 2934 return (error); 2935 } 2936 } 2937 bp->b_wptr += size; 2938 2939 if (stp->sd_wputdatafunc != NULL) { 2940 mblk_t *newbp; 2941 2942 newbp = (stp->sd_wputdatafunc)(stp->sd_vnode, 2943 bp, NULL, NULL, NULL, NULL); 2944 if (newbp == NULL) { 2945 freeb(bp); 2946 freemsg(mp); 2947 return (ECOMM); 2948 } 2949 bp = newbp; 2950 } 2951 } 2952 2953 count -= size; 2954 2955 if (mp == NULL) 2956 mp = bp; 2957 else 2958 linkb(mp, bp); 2959 } while (count > 0); 2960 2961 *mpp = mp; 2962 return (0); 2963 } 2964 2965 /* 2966 * Wait for a buffer to become available. Return non-zero errno 2967 * if not able to wait, 0 if buffer is probably there. 2968 */ 2969 int 2970 strwaitbuf(size_t size, int pri) 2971 { 2972 bufcall_id_t id; 2973 2974 mutex_enter(&bcall_monitor); 2975 if ((id = bufcall(size, pri, (void (*)(void *))cv_broadcast, 2976 &ttoproc(curthread)->p_flag_cv)) == 0) { 2977 mutex_exit(&bcall_monitor); 2978 return (ENOSR); 2979 } 2980 if (!cv_wait_sig(&(ttoproc(curthread)->p_flag_cv), &bcall_monitor)) { 2981 unbufcall(id); 2982 mutex_exit(&bcall_monitor); 2983 return (EINTR); 2984 } 2985 unbufcall(id); 2986 mutex_exit(&bcall_monitor); 2987 return (0); 2988 } 2989 2990 /* 2991 * This function waits for a read or write event to happen on a stream. 2992 * fmode can specify FNDELAY and/or FNONBLOCK. 2993 * The timeout is in ms with -1 meaning infinite. 2994 * The flag values work as follows: 2995 * READWAIT Check for read side errors, send M_READ 2996 * GETWAIT Check for read side errors, no M_READ 2997 * WRITEWAIT Check for write side errors. 2998 * NOINTR Do not return error if nonblocking or timeout. 2999 * STR_NOERROR Ignore all errors except STPLEX. 3000 * STR_NOSIG Ignore/hold signals during the duration of the call. 3001 * STR_PEEK Pass through the strgeterr(). 3002 */ 3003 int 3004 strwaitq(stdata_t *stp, int flag, ssize_t count, int fmode, clock_t timout, 3005 int *done) 3006 { 3007 int slpflg, errs; 3008 int error; 3009 kcondvar_t *sleepon; 3010 mblk_t *mp; 3011 ssize_t *rd_count; 3012 clock_t rval; 3013 3014 ASSERT(MUTEX_HELD(&stp->sd_lock)); 3015 if ((flag & READWAIT) || (flag & GETWAIT)) { 3016 slpflg = RSLEEP; 3017 sleepon = &_RD(stp->sd_wrq)->q_wait; 3018 errs = STRDERR|STPLEX; 3019 } else { 3020 slpflg = WSLEEP; 3021 sleepon = &stp->sd_wrq->q_wait; 3022 errs = STWRERR|STRHUP|STPLEX; 3023 } 3024 if (flag & STR_NOERROR) 3025 errs = STPLEX; 3026 3027 if (stp->sd_wakeq & slpflg) { 3028 /* 3029 * A strwakeq() is pending, no need to sleep. 3030 */ 3031 stp->sd_wakeq &= ~slpflg; 3032 *done = 0; 3033 return (0); 3034 } 3035 3036 if (stp->sd_flag & errs) { 3037 /* 3038 * Check for errors before going to sleep since the 3039 * caller might not have checked this while holding 3040 * sd_lock. 3041 */ 3042 error = strgeterr(stp, errs, (flag & STR_PEEK)); 3043 if (error != 0) { 3044 *done = 1; 3045 return (error); 3046 } 3047 } 3048 3049 /* 3050 * If any module downstream has requested read notification 3051 * by setting SNDMREAD flag using M_SETOPTS, send a message 3052 * down stream. 3053 */ 3054 if ((flag & READWAIT) && (stp->sd_flag & SNDMREAD)) { 3055 mutex_exit(&stp->sd_lock); 3056 if (!(mp = allocb_wait(sizeof (ssize_t), BPRI_MED, 3057 (flag & STR_NOSIG), &error))) { 3058 mutex_enter(&stp->sd_lock); 3059 *done = 1; 3060 return (error); 3061 } 3062 mp->b_datap->db_type = M_READ; 3063 rd_count = (ssize_t *)mp->b_wptr; 3064 *rd_count = count; 3065 mp->b_wptr += sizeof (ssize_t); 3066 /* 3067 * Send the number of bytes requested by the 3068 * read as the argument to M_READ. 3069 */ 3070 stream_willservice(stp); 3071 putnext(stp->sd_wrq, mp); 3072 stream_runservice(stp); 3073 mutex_enter(&stp->sd_lock); 3074 3075 /* 3076 * If any data arrived due to inline processing 3077 * of putnext(), don't sleep. 3078 */ 3079 if (_RD(stp->sd_wrq)->q_first != NULL) { 3080 *done = 0; 3081 return (0); 3082 } 3083 } 3084 3085 if (fmode & (FNDELAY|FNONBLOCK)) { 3086 if (!(flag & NOINTR)) 3087 error = EAGAIN; 3088 else 3089 error = 0; 3090 *done = 1; 3091 return (error); 3092 } 3093 3094 stp->sd_flag |= slpflg; 3095 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAIT2, 3096 "strwaitq sleeps (2):%p, %X, %lX, %X, %p", 3097 stp, flag, count, fmode, done); 3098 3099 rval = str_cv_wait(sleepon, &stp->sd_lock, timout, flag & STR_NOSIG); 3100 if (rval > 0) { 3101 /* EMPTY */ 3102 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAKE2, 3103 "strwaitq awakes(2):%X, %X, %X, %X, %X", 3104 stp, flag, count, fmode, done); 3105 } else if (rval == 0) { 3106 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_INTR2, 3107 "strwaitq interrupt #2:%p, %X, %lX, %X, %p", 3108 stp, flag, count, fmode, done); 3109 stp->sd_flag &= ~slpflg; 3110 cv_broadcast(sleepon); 3111 if (!(flag & NOINTR)) 3112 error = EINTR; 3113 else 3114 error = 0; 3115 *done = 1; 3116 return (error); 3117 } else { 3118 /* timeout */ 3119 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_TIME, 3120 "strwaitq timeout:%p, %X, %lX, %X, %p", 3121 stp, flag, count, fmode, done); 3122 *done = 1; 3123 if (!(flag & NOINTR)) 3124 return (ETIME); 3125 else 3126 return (0); 3127 } 3128 /* 3129 * If the caller implements delayed errors (i.e. queued after data) 3130 * we can not check for errors here since data as well as an 3131 * error might have arrived at the stream head. We return to 3132 * have the caller check the read queue before checking for errors. 3133 */ 3134 if ((stp->sd_flag & errs) && !(flag & STR_DELAYERR)) { 3135 error = strgeterr(stp, errs, (flag & STR_PEEK)); 3136 if (error != 0) { 3137 *done = 1; 3138 return (error); 3139 } 3140 } 3141 *done = 0; 3142 return (0); 3143 } 3144 3145 /* 3146 * Perform job control discipline access checks. 3147 * Return 0 for success and the errno for failure. 3148 */ 3149 3150 #define cantsend(p, t, sig) \ 3151 (sigismember(&(p)->p_ignore, sig) || signal_is_blocked((t), sig)) 3152 3153 int 3154 straccess(struct stdata *stp, enum jcaccess mode) 3155 { 3156 extern kcondvar_t lbolt_cv; /* XXX: should be in a header file */ 3157 kthread_t *t = curthread; 3158 proc_t *p = ttoproc(t); 3159 sess_t *sp; 3160 3161 ASSERT(mutex_owned(&stp->sd_lock)); 3162 3163 if (stp->sd_sidp == NULL || stp->sd_vnode->v_type == VFIFO) 3164 return (0); 3165 3166 mutex_enter(&p->p_lock); /* protects p_pgidp */ 3167 3168 for (;;) { 3169 mutex_enter(&p->p_splock); /* protects p->p_sessp */ 3170 sp = p->p_sessp; 3171 mutex_enter(&sp->s_lock); /* protects sp->* */ 3172 3173 /* 3174 * If this is not the calling process's controlling terminal 3175 * or if the calling process is already in the foreground 3176 * then allow access. 3177 */ 3178 if (sp->s_dev != stp->sd_vnode->v_rdev || 3179 p->p_pgidp == stp->sd_pgidp) { 3180 mutex_exit(&sp->s_lock); 3181 mutex_exit(&p->p_splock); 3182 mutex_exit(&p->p_lock); 3183 return (0); 3184 } 3185 3186 /* 3187 * Check to see if controlling terminal has been deallocated. 3188 */ 3189 if (sp->s_vp == NULL) { 3190 if (!cantsend(p, t, SIGHUP)) 3191 sigtoproc(p, t, SIGHUP); 3192 mutex_exit(&sp->s_lock); 3193 mutex_exit(&p->p_splock); 3194 mutex_exit(&p->p_lock); 3195 return (EIO); 3196 } 3197 3198 mutex_exit(&sp->s_lock); 3199 mutex_exit(&p->p_splock); 3200 3201 if (mode == JCGETP) { 3202 mutex_exit(&p->p_lock); 3203 return (0); 3204 } 3205 3206 if (mode == JCREAD) { 3207 if (p->p_detached || cantsend(p, t, SIGTTIN)) { 3208 mutex_exit(&p->p_lock); 3209 return (EIO); 3210 } 3211 mutex_exit(&p->p_lock); 3212 mutex_exit(&stp->sd_lock); 3213 pgsignal(p->p_pgidp, SIGTTIN); 3214 mutex_enter(&stp->sd_lock); 3215 mutex_enter(&p->p_lock); 3216 } else { /* mode == JCWRITE or JCSETP */ 3217 if ((mode == JCWRITE && !(stp->sd_flag & STRTOSTOP)) || 3218 cantsend(p, t, SIGTTOU)) { 3219 mutex_exit(&p->p_lock); 3220 return (0); 3221 } 3222 if (p->p_detached) { 3223 mutex_exit(&p->p_lock); 3224 return (EIO); 3225 } 3226 mutex_exit(&p->p_lock); 3227 mutex_exit(&stp->sd_lock); 3228 pgsignal(p->p_pgidp, SIGTTOU); 3229 mutex_enter(&stp->sd_lock); 3230 mutex_enter(&p->p_lock); 3231 } 3232 3233 /* 3234 * We call cv_wait_sig_swap() to cause the appropriate 3235 * action for the jobcontrol signal to take place. 3236 * If the signal is being caught, we will take the 3237 * EINTR error return. Otherwise, the default action 3238 * of causing the process to stop will take place. 3239 * In this case, we rely on the periodic cv_broadcast() on 3240 * &lbolt_cv to wake us up to loop around and test again. 3241 * We can't get here if the signal is ignored or 3242 * if the current thread is blocking the signal. 3243 */ 3244 mutex_exit(&stp->sd_lock); 3245 if (!cv_wait_sig_swap(&lbolt_cv, &p->p_lock)) { 3246 mutex_exit(&p->p_lock); 3247 mutex_enter(&stp->sd_lock); 3248 return (EINTR); 3249 } 3250 mutex_exit(&p->p_lock); 3251 mutex_enter(&stp->sd_lock); 3252 mutex_enter(&p->p_lock); 3253 } 3254 } 3255 3256 /* 3257 * Return size of message of block type (bp->b_datap->db_type) 3258 */ 3259 size_t 3260 xmsgsize(mblk_t *bp) 3261 { 3262 unsigned char type; 3263 size_t count = 0; 3264 3265 type = bp->b_datap->db_type; 3266 3267 for (; bp; bp = bp->b_cont) { 3268 if (type != bp->b_datap->db_type) 3269 break; 3270 ASSERT(bp->b_wptr >= bp->b_rptr); 3271 count += bp->b_wptr - bp->b_rptr; 3272 } 3273 return (count); 3274 } 3275 3276 /* 3277 * Allocate a stream head. 3278 */ 3279 struct stdata * 3280 shalloc(queue_t *qp) 3281 { 3282 stdata_t *stp; 3283 3284 stp = kmem_cache_alloc(stream_head_cache, KM_SLEEP); 3285 3286 stp->sd_wrq = _WR(qp); 3287 stp->sd_strtab = NULL; 3288 stp->sd_iocid = 0; 3289 stp->sd_mate = NULL; 3290 stp->sd_freezer = NULL; 3291 stp->sd_refcnt = 0; 3292 stp->sd_wakeq = 0; 3293 stp->sd_anchor = 0; 3294 stp->sd_struiowrq = NULL; 3295 stp->sd_struiordq = NULL; 3296 stp->sd_struiodnak = 0; 3297 stp->sd_struionak = NULL; 3298 stp->sd_t_audit_data = NULL; 3299 stp->sd_rput_opt = 0; 3300 stp->sd_wput_opt = 0; 3301 stp->sd_read_opt = 0; 3302 stp->sd_rprotofunc = strrput_proto; 3303 stp->sd_rmiscfunc = strrput_misc; 3304 stp->sd_rderrfunc = stp->sd_wrerrfunc = NULL; 3305 stp->sd_rputdatafunc = stp->sd_wputdatafunc = NULL; 3306 stp->sd_ciputctrl = NULL; 3307 stp->sd_nciputctrl = 0; 3308 stp->sd_qhead = NULL; 3309 stp->sd_qtail = NULL; 3310 stp->sd_servid = NULL; 3311 stp->sd_nqueues = 0; 3312 stp->sd_svcflags = 0; 3313 stp->sd_copyflag = 0; 3314 3315 return (stp); 3316 } 3317 3318 /* 3319 * Free a stream head. 3320 */ 3321 void 3322 shfree(stdata_t *stp) 3323 { 3324 pid_node_t *pn; 3325 3326 ASSERT(MUTEX_NOT_HELD(&stp->sd_lock)); 3327 3328 stp->sd_wrq = NULL; 3329 3330 mutex_enter(&stp->sd_qlock); 3331 while (stp->sd_svcflags & STRS_SCHEDULED) { 3332 STRSTAT(strwaits); 3333 cv_wait(&stp->sd_qcv, &stp->sd_qlock); 3334 } 3335 mutex_exit(&stp->sd_qlock); 3336 3337 if (stp->sd_ciputctrl != NULL) { 3338 ASSERT(stp->sd_nciputctrl == n_ciputctrl - 1); 3339 SUMCHECK_CIPUTCTRL_COUNTS(stp->sd_ciputctrl, 3340 stp->sd_nciputctrl, 0); 3341 ASSERT(ciputctrl_cache != NULL); 3342 kmem_cache_free(ciputctrl_cache, stp->sd_ciputctrl); 3343 stp->sd_ciputctrl = NULL; 3344 stp->sd_nciputctrl = 0; 3345 } 3346 ASSERT(stp->sd_qhead == NULL); 3347 ASSERT(stp->sd_qtail == NULL); 3348 ASSERT(stp->sd_nqueues == 0); 3349 3350 mutex_enter(&stp->sd_pid_list_lock); 3351 while ((pn = list_head(&stp->sd_pid_list)) != NULL) { 3352 list_remove(&stp->sd_pid_list, pn); 3353 kmem_free(pn, sizeof (*pn)); 3354 } 3355 mutex_exit(&stp->sd_pid_list_lock); 3356 3357 kmem_cache_free(stream_head_cache, stp); 3358 } 3359 3360 void 3361 sh_insert_pid(struct stdata *stp, pid_t pid) 3362 { 3363 pid_node_t *pn; 3364 3365 mutex_enter(&stp->sd_pid_list_lock); 3366 for (pn = list_head(&stp->sd_pid_list); 3367 pn != NULL && pn->pn_pid != pid; 3368 pn = list_next(&stp->sd_pid_list, pn)) 3369 ; 3370 3371 if (pn != NULL) { 3372 pn->pn_count++; 3373 } else { 3374 pn = kmem_zalloc(sizeof (*pn), KM_SLEEP); 3375 list_link_init(&pn->pn_ref_link); 3376 pn->pn_pid = pid; 3377 pn->pn_count = 1; 3378 list_insert_tail(&stp->sd_pid_list, pn); 3379 } 3380 mutex_exit(&stp->sd_pid_list_lock); 3381 } 3382 3383 void 3384 sh_remove_pid(struct stdata *stp, pid_t pid) 3385 { 3386 pid_node_t *pn; 3387 3388 mutex_enter(&stp->sd_pid_list_lock); 3389 for (pn = list_head(&stp->sd_pid_list); 3390 pn != NULL && pn->pn_pid != pid; 3391 pn = list_next(&stp->sd_pid_list, pn)) 3392 ; 3393 3394 if (pn != NULL) { 3395 if (pn->pn_count > 1) { 3396 pn->pn_count--; 3397 } else { 3398 list_remove(&stp->sd_pid_list, pn); 3399 kmem_free(pn, sizeof (*pn)); 3400 } 3401 } 3402 mutex_exit(&stp->sd_pid_list_lock); 3403 } 3404 3405 mblk_t * 3406 sh_get_pid_mblk(struct stdata *stp) 3407 { 3408 mblk_t *mblk; 3409 int sz, n = 0; 3410 pid_t *pids; 3411 pid_node_t *pn; 3412 conn_pid_info_t *cpi; 3413 3414 mutex_enter(&stp->sd_pid_list_lock); 3415 3416 n = list_numnodes(&stp->sd_pid_list); 3417 sz = sizeof (conn_pid_info_t); 3418 sz += (n > 1) ? ((n - 1) * sizeof (pid_t)) : 0; 3419 if ((mblk = allocb(sz, BPRI_HI)) == NULL) { 3420 mutex_exit(&stp->sd_pid_list_lock); 3421 return (NULL); 3422 } 3423 mblk->b_wptr += sz; 3424 cpi = (conn_pid_info_t *)mblk->b_datap->db_base; 3425 cpi->cpi_magic = CONN_PID_INFO_MGC; 3426 cpi->cpi_contents = CONN_PID_INFO_XTI; 3427 cpi->cpi_pids_cnt = n; 3428 cpi->cpi_tot_size = sz; 3429 cpi->cpi_pids[0] = 0; 3430 3431 if (cpi->cpi_pids_cnt > 0) { 3432 pids = cpi->cpi_pids; 3433 for (pn = list_head(&stp->sd_pid_list); pn != NULL; 3434 pids++, pn = list_next(&stp->sd_pid_list, pn)) 3435 *pids = pn->pn_pid; 3436 } 3437 mutex_exit(&stp->sd_pid_list_lock); 3438 return (mblk); 3439 } 3440 3441 /* 3442 * Allocate a pair of queues and a syncq for the pair 3443 */ 3444 queue_t * 3445 allocq(void) 3446 { 3447 queinfo_t *qip; 3448 queue_t *qp, *wqp; 3449 syncq_t *sq; 3450 3451 qip = kmem_cache_alloc(queue_cache, KM_SLEEP); 3452 3453 qp = &qip->qu_rqueue; 3454 wqp = &qip->qu_wqueue; 3455 sq = &qip->qu_syncq; 3456 3457 qp->q_last = NULL; 3458 qp->q_next = NULL; 3459 qp->q_ptr = NULL; 3460 qp->q_flag = QUSE | QREADR; 3461 qp->q_bandp = NULL; 3462 qp->q_stream = NULL; 3463 qp->q_syncq = sq; 3464 qp->q_nband = 0; 3465 qp->q_nfsrv = NULL; 3466 qp->q_draining = 0; 3467 qp->q_syncqmsgs = 0; 3468 qp->q_spri = 0; 3469 qp->q_qtstamp = 0; 3470 qp->q_sqtstamp = 0; 3471 qp->q_fp = NULL; 3472 3473 wqp->q_last = NULL; 3474 wqp->q_next = NULL; 3475 wqp->q_ptr = NULL; 3476 wqp->q_flag = QUSE; 3477 wqp->q_bandp = NULL; 3478 wqp->q_stream = NULL; 3479 wqp->q_syncq = sq; 3480 wqp->q_nband = 0; 3481 wqp->q_nfsrv = NULL; 3482 wqp->q_draining = 0; 3483 wqp->q_syncqmsgs = 0; 3484 wqp->q_qtstamp = 0; 3485 wqp->q_sqtstamp = 0; 3486 wqp->q_spri = 0; 3487 3488 sq->sq_count = 0; 3489 sq->sq_rmqcount = 0; 3490 sq->sq_flags = 0; 3491 sq->sq_type = 0; 3492 sq->sq_callbflags = 0; 3493 sq->sq_cancelid = 0; 3494 sq->sq_ciputctrl = NULL; 3495 sq->sq_nciputctrl = 0; 3496 sq->sq_needexcl = 0; 3497 sq->sq_svcflags = 0; 3498 3499 return (qp); 3500 } 3501 3502 /* 3503 * Free a pair of queues and the "attached" syncq. 3504 * Discard any messages left on the syncq(s), remove the syncq(s) from the 3505 * outer perimeter, and free the syncq(s) if they are not the "attached" syncq. 3506 */ 3507 void 3508 freeq(queue_t *qp) 3509 { 3510 qband_t *qbp, *nqbp; 3511 syncq_t *sq, *outer; 3512 queue_t *wqp = _WR(qp); 3513 3514 ASSERT(qp->q_flag & QREADR); 3515 3516 /* 3517 * If a previously dispatched taskq job is scheduled to run 3518 * sync_service() or a service routine is scheduled for the 3519 * queues about to be freed, wait here until all service is 3520 * done on the queue and all associated queues and syncqs. 3521 */ 3522 wait_svc(qp); 3523 3524 (void) flush_syncq(qp->q_syncq, qp); 3525 (void) flush_syncq(wqp->q_syncq, wqp); 3526 ASSERT(qp->q_syncqmsgs == 0 && wqp->q_syncqmsgs == 0); 3527 3528 /* 3529 * Flush the queues before q_next is set to NULL This is needed 3530 * in order to backenable any downstream queue before we go away. 3531 * Note: we are already removed from the stream so that the 3532 * backenabling will not cause any messages to be delivered to our 3533 * put procedures. 3534 */ 3535 flushq(qp, FLUSHALL); 3536 flushq(wqp, FLUSHALL); 3537 3538 /* Tidy up - removeq only does a half-remove from stream */ 3539 qp->q_next = wqp->q_next = NULL; 3540 ASSERT(!(qp->q_flag & QENAB)); 3541 ASSERT(!(wqp->q_flag & QENAB)); 3542 3543 outer = qp->q_syncq->sq_outer; 3544 if (outer != NULL) { 3545 outer_remove(outer, qp->q_syncq); 3546 if (wqp->q_syncq != qp->q_syncq) 3547 outer_remove(outer, wqp->q_syncq); 3548 } 3549 /* 3550 * Free any syncqs that are outside what allocq returned. 3551 */ 3552 if (qp->q_syncq != SQ(qp) && !(qp->q_flag & QPERMOD)) 3553 free_syncq(qp->q_syncq); 3554 if (qp->q_syncq != wqp->q_syncq && wqp->q_syncq != SQ(qp)) 3555 free_syncq(wqp->q_syncq); 3556 3557 ASSERT((qp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); 3558 ASSERT((wqp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); 3559 ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); 3560 ASSERT(MUTEX_NOT_HELD(QLOCK(wqp))); 3561 sq = SQ(qp); 3562 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 3563 ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); 3564 ASSERT(sq->sq_outer == NULL); 3565 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 3566 ASSERT(sq->sq_callbpend == NULL); 3567 ASSERT(sq->sq_needexcl == 0); 3568 3569 if (sq->sq_ciputctrl != NULL) { 3570 ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); 3571 SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, 3572 sq->sq_nciputctrl, 0); 3573 ASSERT(ciputctrl_cache != NULL); 3574 kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); 3575 sq->sq_ciputctrl = NULL; 3576 sq->sq_nciputctrl = 0; 3577 } 3578 3579 ASSERT(qp->q_first == NULL && wqp->q_first == NULL); 3580 ASSERT(qp->q_count == 0 && wqp->q_count == 0); 3581 ASSERT(qp->q_mblkcnt == 0 && wqp->q_mblkcnt == 0); 3582 3583 qp->q_flag &= ~QUSE; 3584 wqp->q_flag &= ~QUSE; 3585 3586 /* NOTE: Uncomment the assert below once bugid 1159635 is fixed. */ 3587 /* ASSERT((qp->q_flag & QWANTW) == 0 && (wqp->q_flag & QWANTW) == 0); */ 3588 3589 qbp = qp->q_bandp; 3590 while (qbp) { 3591 nqbp = qbp->qb_next; 3592 freeband(qbp); 3593 qbp = nqbp; 3594 } 3595 qbp = wqp->q_bandp; 3596 while (qbp) { 3597 nqbp = qbp->qb_next; 3598 freeband(qbp); 3599 qbp = nqbp; 3600 } 3601 kmem_cache_free(queue_cache, qp); 3602 } 3603 3604 /* 3605 * Allocate a qband structure. 3606 */ 3607 qband_t * 3608 allocband(void) 3609 { 3610 qband_t *qbp; 3611 3612 qbp = kmem_cache_alloc(qband_cache, KM_NOSLEEP); 3613 if (qbp == NULL) 3614 return (NULL); 3615 3616 qbp->qb_next = NULL; 3617 qbp->qb_count = 0; 3618 qbp->qb_mblkcnt = 0; 3619 qbp->qb_first = NULL; 3620 qbp->qb_last = NULL; 3621 qbp->qb_flag = 0; 3622 3623 return (qbp); 3624 } 3625 3626 /* 3627 * Free a qband structure. 3628 */ 3629 void 3630 freeband(qband_t *qbp) 3631 { 3632 kmem_cache_free(qband_cache, qbp); 3633 } 3634 3635 /* 3636 * Just like putnextctl(9F), except that allocb_wait() is used. 3637 * 3638 * Consolidation Private, and of course only callable from the stream head or 3639 * routines that may block. 3640 */ 3641 int 3642 putnextctl_wait(queue_t *q, int type) 3643 { 3644 mblk_t *bp; 3645 int error; 3646 3647 if ((datamsg(type) && (type != M_DELAY)) || 3648 (bp = allocb_wait(0, BPRI_HI, 0, &error)) == NULL) 3649 return (0); 3650 3651 bp->b_datap->db_type = (unsigned char)type; 3652 putnext(q, bp); 3653 return (1); 3654 } 3655 3656 /* 3657 * Run any possible bufcalls. 3658 */ 3659 void 3660 runbufcalls(void) 3661 { 3662 strbufcall_t *bcp; 3663 3664 mutex_enter(&bcall_monitor); 3665 mutex_enter(&strbcall_lock); 3666 3667 if (strbcalls.bc_head) { 3668 size_t count; 3669 int nevent; 3670 3671 /* 3672 * count how many events are on the list 3673 * now so we can check to avoid looping 3674 * in low memory situations 3675 */ 3676 nevent = 0; 3677 for (bcp = strbcalls.bc_head; bcp; bcp = bcp->bc_next) 3678 nevent++; 3679 3680 /* 3681 * get estimate of available memory from kmem_avail(). 3682 * awake all bufcall functions waiting for 3683 * memory whose request could be satisfied 3684 * by 'count' memory and let 'em fight for it. 3685 */ 3686 count = kmem_avail(); 3687 while ((bcp = strbcalls.bc_head) != NULL && nevent) { 3688 STRSTAT(bufcalls); 3689 --nevent; 3690 if (bcp->bc_size <= count) { 3691 bcp->bc_executor = curthread; 3692 mutex_exit(&strbcall_lock); 3693 (*bcp->bc_func)(bcp->bc_arg); 3694 mutex_enter(&strbcall_lock); 3695 bcp->bc_executor = NULL; 3696 cv_broadcast(&bcall_cv); 3697 strbcalls.bc_head = bcp->bc_next; 3698 kmem_free(bcp, sizeof (strbufcall_t)); 3699 } else { 3700 /* 3701 * too big, try again later - note 3702 * that nevent was decremented above 3703 * so we won't retry this one on this 3704 * iteration of the loop 3705 */ 3706 if (bcp->bc_next != NULL) { 3707 strbcalls.bc_head = bcp->bc_next; 3708 bcp->bc_next = NULL; 3709 strbcalls.bc_tail->bc_next = bcp; 3710 strbcalls.bc_tail = bcp; 3711 } 3712 } 3713 } 3714 if (strbcalls.bc_head == NULL) 3715 strbcalls.bc_tail = NULL; 3716 } 3717 3718 mutex_exit(&strbcall_lock); 3719 mutex_exit(&bcall_monitor); 3720 } 3721 3722 3723 /* 3724 * Actually run queue's service routine. 3725 */ 3726 static void 3727 runservice(queue_t *q) 3728 { 3729 qband_t *qbp; 3730 3731 ASSERT(q->q_qinfo->qi_srvp); 3732 again: 3733 entersq(q->q_syncq, SQ_SVC); 3734 TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_START, 3735 "runservice starts:%p", q); 3736 3737 if (!(q->q_flag & QWCLOSE)) 3738 (*q->q_qinfo->qi_srvp)(q); 3739 3740 TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_END, 3741 "runservice ends:(%p)", q); 3742 3743 leavesq(q->q_syncq, SQ_SVC); 3744 3745 mutex_enter(QLOCK(q)); 3746 if (q->q_flag & QENAB) { 3747 q->q_flag &= ~QENAB; 3748 mutex_exit(QLOCK(q)); 3749 goto again; 3750 } 3751 q->q_flag &= ~QINSERVICE; 3752 q->q_flag &= ~QBACK; 3753 for (qbp = q->q_bandp; qbp; qbp = qbp->qb_next) 3754 qbp->qb_flag &= ~QB_BACK; 3755 /* 3756 * Wakeup thread waiting for the service procedure 3757 * to be run (strclose and qdetach). 3758 */ 3759 cv_broadcast(&q->q_wait); 3760 3761 mutex_exit(QLOCK(q)); 3762 } 3763 3764 /* 3765 * Background processing of bufcalls. 3766 */ 3767 void 3768 streams_bufcall_service(void) 3769 { 3770 callb_cpr_t cprinfo; 3771 3772 CALLB_CPR_INIT(&cprinfo, &strbcall_lock, callb_generic_cpr, 3773 "streams_bufcall_service"); 3774 3775 mutex_enter(&strbcall_lock); 3776 3777 for (;;) { 3778 if (strbcalls.bc_head != NULL && kmem_avail() > 0) { 3779 mutex_exit(&strbcall_lock); 3780 runbufcalls(); 3781 mutex_enter(&strbcall_lock); 3782 } 3783 if (strbcalls.bc_head != NULL) { 3784 STRSTAT(bcwaits); 3785 /* Wait for memory to become available */ 3786 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3787 (void) cv_reltimedwait(&memavail_cv, &strbcall_lock, 3788 SEC_TO_TICK(60), TR_CLOCK_TICK); 3789 CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); 3790 } 3791 3792 /* Wait for new work to arrive */ 3793 if (strbcalls.bc_head == NULL) { 3794 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3795 cv_wait(&strbcall_cv, &strbcall_lock); 3796 CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); 3797 } 3798 } 3799 } 3800 3801 /* 3802 * Background processing of streams background tasks which failed 3803 * taskq_dispatch. 3804 */ 3805 static void 3806 streams_qbkgrnd_service(void) 3807 { 3808 callb_cpr_t cprinfo; 3809 queue_t *q; 3810 3811 CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, 3812 "streams_bkgrnd_service"); 3813 3814 mutex_enter(&service_queue); 3815 3816 for (;;) { 3817 /* 3818 * Wait for work to arrive. 3819 */ 3820 while ((freebs_list == NULL) && (qhead == NULL)) { 3821 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3822 cv_wait(&services_to_run, &service_queue); 3823 CALLB_CPR_SAFE_END(&cprinfo, &service_queue); 3824 } 3825 /* 3826 * Handle all pending freebs requests to free memory. 3827 */ 3828 while (freebs_list != NULL) { 3829 mblk_t *mp = freebs_list; 3830 freebs_list = mp->b_next; 3831 mutex_exit(&service_queue); 3832 mblk_free(mp); 3833 mutex_enter(&service_queue); 3834 } 3835 /* 3836 * Run pending queues. 3837 */ 3838 while (qhead != NULL) { 3839 DQ(q, qhead, qtail, q_link); 3840 ASSERT(q != NULL); 3841 mutex_exit(&service_queue); 3842 queue_service(q); 3843 mutex_enter(&service_queue); 3844 } 3845 ASSERT(qhead == NULL && qtail == NULL); 3846 } 3847 } 3848 3849 /* 3850 * Background processing of streams background tasks which failed 3851 * taskq_dispatch. 3852 */ 3853 static void 3854 streams_sqbkgrnd_service(void) 3855 { 3856 callb_cpr_t cprinfo; 3857 syncq_t *sq; 3858 3859 CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, 3860 "streams_sqbkgrnd_service"); 3861 3862 mutex_enter(&service_queue); 3863 3864 for (;;) { 3865 /* 3866 * Wait for work to arrive. 3867 */ 3868 while (sqhead == NULL) { 3869 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3870 cv_wait(&syncqs_to_run, &service_queue); 3871 CALLB_CPR_SAFE_END(&cprinfo, &service_queue); 3872 } 3873 3874 /* 3875 * Run pending syncqs. 3876 */ 3877 while (sqhead != NULL) { 3878 DQ(sq, sqhead, sqtail, sq_next); 3879 ASSERT(sq != NULL); 3880 ASSERT(sq->sq_svcflags & SQ_BGTHREAD); 3881 mutex_exit(&service_queue); 3882 syncq_service(sq); 3883 mutex_enter(&service_queue); 3884 } 3885 } 3886 } 3887 3888 /* 3889 * Disable the syncq and wait for background syncq processing to complete. 3890 * If the syncq is placed on the sqhead/sqtail queue, try to remove it from the 3891 * list. 3892 */ 3893 void 3894 wait_sq_svc(syncq_t *sq) 3895 { 3896 mutex_enter(SQLOCK(sq)); 3897 sq->sq_svcflags |= SQ_DISABLED; 3898 if (sq->sq_svcflags & SQ_BGTHREAD) { 3899 syncq_t *sq_chase; 3900 syncq_t *sq_curr; 3901 int removed; 3902 3903 ASSERT(sq->sq_servcount == 1); 3904 mutex_enter(&service_queue); 3905 RMQ(sq, sqhead, sqtail, sq_next, sq_chase, sq_curr, removed); 3906 mutex_exit(&service_queue); 3907 if (removed) { 3908 sq->sq_svcflags &= ~SQ_BGTHREAD; 3909 sq->sq_servcount = 0; 3910 STRSTAT(sqremoved); 3911 goto done; 3912 } 3913 } 3914 while (sq->sq_servcount != 0) { 3915 sq->sq_flags |= SQ_WANTWAKEUP; 3916 cv_wait(&sq->sq_wait, SQLOCK(sq)); 3917 } 3918 done: 3919 mutex_exit(SQLOCK(sq)); 3920 } 3921 3922 /* 3923 * Put a syncq on the list of syncq's to be serviced by the sqthread. 3924 * Add the argument to the end of the sqhead list and set the flag 3925 * indicating this syncq has been enabled. If it has already been 3926 * enabled, don't do anything. 3927 * This routine assumes that SQLOCK is held. 3928 * NOTE that the lock order is to have the SQLOCK first, 3929 * so if the service_syncq lock is held, we need to release it 3930 * before acquiring the SQLOCK (mostly relevant for the background 3931 * thread, and this seems to be common among the STREAMS global locks). 3932 * Note that the sq_svcflags are protected by the SQLOCK. 3933 */ 3934 void 3935 sqenable(syncq_t *sq) 3936 { 3937 /* 3938 * This is probably not important except for where I believe it 3939 * is being called. At that point, it should be held (and it 3940 * is a pain to release it just for this routine, so don't do 3941 * it). 3942 */ 3943 ASSERT(MUTEX_HELD(SQLOCK(sq))); 3944 3945 IMPLY(sq->sq_servcount == 0, sq->sq_next == NULL); 3946 IMPLY(sq->sq_next != NULL, sq->sq_svcflags & SQ_BGTHREAD); 3947 3948 /* 3949 * Do not put on list if background thread is scheduled or 3950 * syncq is disabled. 3951 */ 3952 if (sq->sq_svcflags & (SQ_DISABLED | SQ_BGTHREAD)) 3953 return; 3954 3955 /* 3956 * Check whether we should enable sq at all. 3957 * Non PERMOD syncqs may be drained by at most one thread. 3958 * PERMOD syncqs may be drained by several threads but we limit the 3959 * total amount to the lesser of 3960 * Number of queues on the squeue and 3961 * Number of CPUs. 3962 */ 3963 if (sq->sq_servcount != 0) { 3964 if (((sq->sq_type & SQ_PERMOD) == 0) || 3965 (sq->sq_servcount >= MIN(sq->sq_nqueues, ncpus_online))) { 3966 STRSTAT(sqtoomany); 3967 return; 3968 } 3969 } 3970 3971 sq->sq_tstamp = ddi_get_lbolt(); 3972 STRSTAT(sqenables); 3973 3974 /* Attempt a taskq dispatch */ 3975 sq->sq_servid = (void *)taskq_dispatch(streams_taskq, 3976 (task_func_t *)syncq_service, sq, TQ_NOSLEEP | TQ_NOQUEUE); 3977 if (sq->sq_servid != NULL) { 3978 sq->sq_servcount++; 3979 return; 3980 } 3981 3982 /* 3983 * This taskq dispatch failed, but a previous one may have succeeded. 3984 * Don't try to schedule on the background thread whilst there is 3985 * outstanding taskq processing. 3986 */ 3987 if (sq->sq_servcount != 0) 3988 return; 3989 3990 /* 3991 * System is low on resources and can't perform a non-sleeping 3992 * dispatch. Schedule the syncq for a background thread and mark the 3993 * syncq to avoid any further taskq dispatch attempts. 3994 */ 3995 mutex_enter(&service_queue); 3996 STRSTAT(taskqfails); 3997 ENQUEUE(sq, sqhead, sqtail, sq_next); 3998 sq->sq_svcflags |= SQ_BGTHREAD; 3999 sq->sq_servcount = 1; 4000 cv_signal(&syncqs_to_run); 4001 mutex_exit(&service_queue); 4002 } 4003 4004 /* 4005 * Note: fifo_close() depends on the mblk_t on the queue being freed 4006 * asynchronously. The asynchronous freeing of messages breaks the 4007 * recursive call chain of fifo_close() while there are I_SENDFD type of 4008 * messages referring to other file pointers on the queue. Then when 4009 * closing pipes it can avoid stack overflow in case of daisy-chained 4010 * pipes, and also avoid deadlock in case of fifonode_t pairs (which 4011 * share the same fifolock_t). 4012 * 4013 * No need to kpreempt_disable to access cpu_seqid. If we migrate and 4014 * the esb queue does not match the new CPU, that is OK. 4015 */ 4016 void 4017 freebs_enqueue(mblk_t *mp, dblk_t *dbp) 4018 { 4019 int qindex = CPU->cpu_seqid >> esbq_log2_cpus_per_q; 4020 esb_queue_t *eqp; 4021 4022 ASSERT(dbp->db_mblk == mp); 4023 ASSERT(qindex < esbq_nelem); 4024 4025 eqp = system_esbq_array; 4026 if (eqp != NULL) { 4027 eqp += qindex; 4028 } else { 4029 mutex_enter(&esbq_lock); 4030 if (kmem_ready && system_esbq_array == NULL) 4031 system_esbq_array = (esb_queue_t *)kmem_zalloc( 4032 esbq_nelem * sizeof (esb_queue_t), KM_NOSLEEP); 4033 mutex_exit(&esbq_lock); 4034 eqp = system_esbq_array; 4035 if (eqp != NULL) 4036 eqp += qindex; 4037 else 4038 eqp = &system_esbq; 4039 } 4040 4041 /* 4042 * Check data sanity. The dblock should have non-empty free function. 4043 * It is better to panic here then later when the dblock is freed 4044 * asynchronously when the context is lost. 4045 */ 4046 if (dbp->db_frtnp->free_func == NULL) { 4047 panic("freebs_enqueue: dblock %p has a NULL free callback", 4048 (void *)dbp); 4049 } 4050 4051 mutex_enter(&eqp->eq_lock); 4052 /* queue the new mblk on the esballoc queue */ 4053 if (eqp->eq_head == NULL) { 4054 eqp->eq_head = eqp->eq_tail = mp; 4055 } else { 4056 eqp->eq_tail->b_next = mp; 4057 eqp->eq_tail = mp; 4058 } 4059 eqp->eq_len++; 4060 4061 /* If we're the first thread to reach the threshold, process */ 4062 if (eqp->eq_len >= esbq_max_qlen && 4063 !(eqp->eq_flags & ESBQ_PROCESSING)) 4064 esballoc_process_queue(eqp); 4065 4066 esballoc_set_timer(eqp, esbq_timeout); 4067 mutex_exit(&eqp->eq_lock); 4068 } 4069 4070 static void 4071 esballoc_process_queue(esb_queue_t *eqp) 4072 { 4073 mblk_t *mp; 4074 4075 ASSERT(MUTEX_HELD(&eqp->eq_lock)); 4076 4077 eqp->eq_flags |= ESBQ_PROCESSING; 4078 4079 do { 4080 /* 4081 * Detach the message chain for processing. 4082 */ 4083 mp = eqp->eq_head; 4084 eqp->eq_tail->b_next = NULL; 4085 eqp->eq_head = eqp->eq_tail = NULL; 4086 eqp->eq_len = 0; 4087 mutex_exit(&eqp->eq_lock); 4088 4089 /* 4090 * Process the message chain. 4091 */ 4092 esballoc_enqueue_mblk(mp); 4093 mutex_enter(&eqp->eq_lock); 4094 } while ((eqp->eq_len >= esbq_max_qlen) && (eqp->eq_len > 0)); 4095 4096 eqp->eq_flags &= ~ESBQ_PROCESSING; 4097 } 4098 4099 /* 4100 * taskq callback routine to free esballoced mblk's 4101 */ 4102 static void 4103 esballoc_mblk_free(mblk_t *mp) 4104 { 4105 mblk_t *nextmp; 4106 4107 for (; mp != NULL; mp = nextmp) { 4108 nextmp = mp->b_next; 4109 mp->b_next = NULL; 4110 mblk_free(mp); 4111 } 4112 } 4113 4114 static void 4115 esballoc_enqueue_mblk(mblk_t *mp) 4116 { 4117 4118 if (taskq_dispatch(system_taskq, (task_func_t *)esballoc_mblk_free, mp, 4119 TQ_NOSLEEP) == NULL) { 4120 mblk_t *first_mp = mp; 4121 /* 4122 * System is low on resources and can't perform a non-sleeping 4123 * dispatch. Schedule for a background thread. 4124 */ 4125 mutex_enter(&service_queue); 4126 STRSTAT(taskqfails); 4127 4128 while (mp->b_next != NULL) 4129 mp = mp->b_next; 4130 4131 mp->b_next = freebs_list; 4132 freebs_list = first_mp; 4133 cv_signal(&services_to_run); 4134 mutex_exit(&service_queue); 4135 } 4136 } 4137 4138 static void 4139 esballoc_timer(void *arg) 4140 { 4141 esb_queue_t *eqp = arg; 4142 4143 mutex_enter(&eqp->eq_lock); 4144 eqp->eq_flags &= ~ESBQ_TIMER; 4145 4146 if (!(eqp->eq_flags & ESBQ_PROCESSING) && 4147 eqp->eq_len > 0) 4148 esballoc_process_queue(eqp); 4149 4150 esballoc_set_timer(eqp, esbq_timeout); 4151 mutex_exit(&eqp->eq_lock); 4152 } 4153 4154 static void 4155 esballoc_set_timer(esb_queue_t *eqp, clock_t eq_timeout) 4156 { 4157 ASSERT(MUTEX_HELD(&eqp->eq_lock)); 4158 4159 if (eqp->eq_len > 0 && !(eqp->eq_flags & ESBQ_TIMER)) { 4160 (void) timeout(esballoc_timer, eqp, eq_timeout); 4161 eqp->eq_flags |= ESBQ_TIMER; 4162 } 4163 } 4164 4165 /* 4166 * Setup esbq array length based upon NCPU scaled by CPUs per 4167 * queue. Use static system_esbq until kmem_ready and we can 4168 * create an array in freebs_enqueue(). 4169 */ 4170 void 4171 esballoc_queue_init(void) 4172 { 4173 esbq_log2_cpus_per_q = highbit(esbq_cpus_per_q - 1); 4174 esbq_cpus_per_q = 1 << esbq_log2_cpus_per_q; 4175 esbq_nelem = howmany(NCPU, esbq_cpus_per_q); 4176 system_esbq.eq_len = 0; 4177 system_esbq.eq_head = system_esbq.eq_tail = NULL; 4178 system_esbq.eq_flags = 0; 4179 } 4180 4181 /* 4182 * Set the QBACK or QB_BACK flag in the given queue for 4183 * the given priority band. 4184 */ 4185 void 4186 setqback(queue_t *q, unsigned char pri) 4187 { 4188 int i; 4189 qband_t *qbp; 4190 qband_t **qbpp; 4191 4192 ASSERT(MUTEX_HELD(QLOCK(q))); 4193 if (pri != 0) { 4194 if (pri > q->q_nband) { 4195 qbpp = &q->q_bandp; 4196 while (*qbpp) 4197 qbpp = &(*qbpp)->qb_next; 4198 while (pri > q->q_nband) { 4199 if ((*qbpp = allocband()) == NULL) { 4200 cmn_err(CE_WARN, 4201 "setqback: can't allocate qband\n"); 4202 return; 4203 } 4204 (*qbpp)->qb_hiwat = q->q_hiwat; 4205 (*qbpp)->qb_lowat = q->q_lowat; 4206 q->q_nband++; 4207 qbpp = &(*qbpp)->qb_next; 4208 } 4209 } 4210 qbp = q->q_bandp; 4211 i = pri; 4212 while (--i) 4213 qbp = qbp->qb_next; 4214 qbp->qb_flag |= QB_BACK; 4215 } else { 4216 q->q_flag |= QBACK; 4217 } 4218 } 4219 4220 int 4221 strcopyin(void *from, void *to, size_t len, int copyflag) 4222 { 4223 if (copyflag & U_TO_K) { 4224 ASSERT((copyflag & K_TO_K) == 0); 4225 if (copyin(from, to, len)) 4226 return (EFAULT); 4227 } else { 4228 ASSERT(copyflag & K_TO_K); 4229 bcopy(from, to, len); 4230 } 4231 return (0); 4232 } 4233 4234 int 4235 strcopyout(void *from, void *to, size_t len, int copyflag) 4236 { 4237 if (copyflag & U_TO_K) { 4238 if (copyout(from, to, len)) 4239 return (EFAULT); 4240 } else { 4241 ASSERT(copyflag & K_TO_K); 4242 bcopy(from, to, len); 4243 } 4244 return (0); 4245 } 4246 4247 /* 4248 * strsignal_nolock() posts a signal to the process(es) at the stream head. 4249 * It assumes that the stream head lock is already held, whereas strsignal() 4250 * acquires the lock first. This routine was created because a few callers 4251 * release the stream head lock before calling only to re-acquire it after 4252 * it returns. 4253 */ 4254 void 4255 strsignal_nolock(stdata_t *stp, int sig, uchar_t band) 4256 { 4257 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4258 switch (sig) { 4259 case SIGPOLL: 4260 if (stp->sd_sigflags & S_MSG) 4261 strsendsig(stp->sd_siglist, S_MSG, band, 0); 4262 break; 4263 default: 4264 if (stp->sd_pgidp) 4265 pgsignal(stp->sd_pgidp, sig); 4266 break; 4267 } 4268 } 4269 4270 void 4271 strsignal(stdata_t *stp, int sig, int32_t band) 4272 { 4273 TRACE_3(TR_FAC_STREAMS_FR, TR_SENDSIG, 4274 "strsignal:%p, %X, %X", stp, sig, band); 4275 4276 mutex_enter(&stp->sd_lock); 4277 switch (sig) { 4278 case SIGPOLL: 4279 if (stp->sd_sigflags & S_MSG) 4280 strsendsig(stp->sd_siglist, S_MSG, (uchar_t)band, 0); 4281 break; 4282 4283 default: 4284 if (stp->sd_pgidp) { 4285 pgsignal(stp->sd_pgidp, sig); 4286 } 4287 break; 4288 } 4289 mutex_exit(&stp->sd_lock); 4290 } 4291 4292 void 4293 strhup(stdata_t *stp) 4294 { 4295 ASSERT(mutex_owned(&stp->sd_lock)); 4296 pollwakeup(&stp->sd_pollist, POLLHUP); 4297 if (stp->sd_sigflags & S_HANGUP) 4298 strsendsig(stp->sd_siglist, S_HANGUP, 0, 0); 4299 } 4300 4301 /* 4302 * Backenable the first queue upstream from `q' with a service procedure. 4303 */ 4304 void 4305 backenable(queue_t *q, uchar_t pri) 4306 { 4307 queue_t *nq; 4308 4309 /* 4310 * Our presence might not prevent other modules in our own 4311 * stream from popping/pushing since the caller of getq might not 4312 * have a claim on the queue (some drivers do a getq on somebody 4313 * else's queue - they know that the queue itself is not going away 4314 * but the framework has to guarantee q_next in that stream). 4315 */ 4316 claimstr(q); 4317 4318 /* Find nearest back queue with service proc */ 4319 for (nq = backq(q); nq && !nq->q_qinfo->qi_srvp; nq = backq(nq)) { 4320 ASSERT(STRMATED(q->q_stream) || STREAM(q) == STREAM(nq)); 4321 } 4322 4323 if (nq) { 4324 kthread_t *freezer; 4325 /* 4326 * backenable can be called either with no locks held 4327 * or with the stream frozen (the latter occurs when a module 4328 * calls rmvq with the stream frozen). If the stream is frozen 4329 * by the caller the caller will hold all qlocks in the stream. 4330 * Note that a frozen stream doesn't freeze a mated stream, 4331 * so we explicitly check for that. 4332 */ 4333 freezer = STREAM(q)->sd_freezer; 4334 if (freezer != curthread || STREAM(q) != STREAM(nq)) { 4335 mutex_enter(QLOCK(nq)); 4336 } 4337 #ifdef DEBUG 4338 else { 4339 ASSERT(frozenstr(q)); 4340 ASSERT(MUTEX_HELD(QLOCK(q))); 4341 ASSERT(MUTEX_HELD(QLOCK(nq))); 4342 } 4343 #endif 4344 setqback(nq, pri); 4345 qenable_locked(nq); 4346 if (freezer != curthread || STREAM(q) != STREAM(nq)) 4347 mutex_exit(QLOCK(nq)); 4348 } 4349 releasestr(q); 4350 } 4351 4352 /* 4353 * Return the appropriate errno when one of flags_to_check is set 4354 * in sd_flags. Uses the exported error routines if they are set. 4355 * Will return 0 if non error is set (or if the exported error routines 4356 * do not return an error). 4357 * 4358 * If there is both a read and write error to check, we prefer the read error. 4359 * Also, give preference to recorded errno's over the error functions. 4360 * The flags that are handled are: 4361 * STPLEX return EINVAL 4362 * STRDERR return sd_rerror (and clear if STRDERRNONPERSIST) 4363 * STWRERR return sd_werror (and clear if STWRERRNONPERSIST) 4364 * STRHUP return sd_werror 4365 * 4366 * If the caller indicates that the operation is a peek, a nonpersistent error 4367 * is not cleared. 4368 */ 4369 int 4370 strgeterr(stdata_t *stp, int32_t flags_to_check, int ispeek) 4371 { 4372 int32_t sd_flag = stp->sd_flag & flags_to_check; 4373 int error = 0; 4374 4375 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4376 ASSERT((flags_to_check & ~(STRDERR|STWRERR|STRHUP|STPLEX)) == 0); 4377 if (sd_flag & STPLEX) 4378 error = EINVAL; 4379 else if (sd_flag & STRDERR) { 4380 error = stp->sd_rerror; 4381 if ((stp->sd_flag & STRDERRNONPERSIST) && !ispeek) { 4382 /* 4383 * Read errors are non-persistent i.e. discarded once 4384 * returned to a non-peeking caller, 4385 */ 4386 stp->sd_rerror = 0; 4387 stp->sd_flag &= ~STRDERR; 4388 } 4389 if (error == 0 && stp->sd_rderrfunc != NULL) { 4390 int clearerr = 0; 4391 4392 error = (*stp->sd_rderrfunc)(stp->sd_vnode, ispeek, 4393 &clearerr); 4394 if (clearerr) { 4395 stp->sd_flag &= ~STRDERR; 4396 stp->sd_rderrfunc = NULL; 4397 } 4398 } 4399 } else if (sd_flag & STWRERR) { 4400 error = stp->sd_werror; 4401 if ((stp->sd_flag & STWRERRNONPERSIST) && !ispeek) { 4402 /* 4403 * Write errors are non-persistent i.e. discarded once 4404 * returned to a non-peeking caller, 4405 */ 4406 stp->sd_werror = 0; 4407 stp->sd_flag &= ~STWRERR; 4408 } 4409 if (error == 0 && stp->sd_wrerrfunc != NULL) { 4410 int clearerr = 0; 4411 4412 error = (*stp->sd_wrerrfunc)(stp->sd_vnode, ispeek, 4413 &clearerr); 4414 if (clearerr) { 4415 stp->sd_flag &= ~STWRERR; 4416 stp->sd_wrerrfunc = NULL; 4417 } 4418 } 4419 } else if (sd_flag & STRHUP) { 4420 /* sd_werror set when STRHUP */ 4421 error = stp->sd_werror; 4422 } 4423 return (error); 4424 } 4425 4426 4427 /* 4428 * Single-thread open/close/push/pop 4429 * for twisted streams also 4430 */ 4431 int 4432 strstartplumb(stdata_t *stp, int flag, int cmd) 4433 { 4434 int waited = 1; 4435 int error = 0; 4436 4437 if (STRMATED(stp)) { 4438 struct stdata *stmatep = stp->sd_mate; 4439 4440 STRLOCKMATES(stp); 4441 while (waited) { 4442 waited = 0; 4443 while (stmatep->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4444 if ((cmd == I_POP) && 4445 (flag & (FNDELAY|FNONBLOCK))) { 4446 STRUNLOCKMATES(stp); 4447 return (EAGAIN); 4448 } 4449 waited = 1; 4450 mutex_exit(&stp->sd_lock); 4451 if (!cv_wait_sig(&stmatep->sd_monitor, 4452 &stmatep->sd_lock)) { 4453 mutex_exit(&stmatep->sd_lock); 4454 return (EINTR); 4455 } 4456 mutex_exit(&stmatep->sd_lock); 4457 STRLOCKMATES(stp); 4458 } 4459 while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4460 if ((cmd == I_POP) && 4461 (flag & (FNDELAY|FNONBLOCK))) { 4462 STRUNLOCKMATES(stp); 4463 return (EAGAIN); 4464 } 4465 waited = 1; 4466 mutex_exit(&stmatep->sd_lock); 4467 if (!cv_wait_sig(&stp->sd_monitor, 4468 &stp->sd_lock)) { 4469 mutex_exit(&stp->sd_lock); 4470 return (EINTR); 4471 } 4472 mutex_exit(&stp->sd_lock); 4473 STRLOCKMATES(stp); 4474 } 4475 if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { 4476 error = strgeterr(stp, 4477 STRDERR|STWRERR|STRHUP|STPLEX, 0); 4478 if (error != 0) { 4479 STRUNLOCKMATES(stp); 4480 return (error); 4481 } 4482 } 4483 } 4484 stp->sd_flag |= STRPLUMB; 4485 STRUNLOCKMATES(stp); 4486 } else { 4487 mutex_enter(&stp->sd_lock); 4488 while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4489 if (((cmd == I_POP) || (cmd == _I_REMOVE)) && 4490 (flag & (FNDELAY|FNONBLOCK))) { 4491 mutex_exit(&stp->sd_lock); 4492 return (EAGAIN); 4493 } 4494 if (!cv_wait_sig(&stp->sd_monitor, &stp->sd_lock)) { 4495 mutex_exit(&stp->sd_lock); 4496 return (EINTR); 4497 } 4498 if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { 4499 error = strgeterr(stp, 4500 STRDERR|STWRERR|STRHUP|STPLEX, 0); 4501 if (error != 0) { 4502 mutex_exit(&stp->sd_lock); 4503 return (error); 4504 } 4505 } 4506 } 4507 stp->sd_flag |= STRPLUMB; 4508 mutex_exit(&stp->sd_lock); 4509 } 4510 return (0); 4511 } 4512 4513 /* 4514 * Complete the plumbing operation associated with stream `stp'. 4515 */ 4516 void 4517 strendplumb(stdata_t *stp) 4518 { 4519 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4520 ASSERT(stp->sd_flag & STRPLUMB); 4521 stp->sd_flag &= ~STRPLUMB; 4522 cv_broadcast(&stp->sd_monitor); 4523 } 4524 4525 /* 4526 * This describes how the STREAMS framework handles synchronization 4527 * during open/push and close/pop. 4528 * The key interfaces for open and close are qprocson and qprocsoff, 4529 * respectively. While the close case in general is harder both open 4530 * have close have significant similarities. 4531 * 4532 * During close the STREAMS framework has to both ensure that there 4533 * are no stale references to the queue pair (and syncq) that 4534 * are being closed and also provide the guarantees that are documented 4535 * in qprocsoff(9F). 4536 * If there are stale references to the queue that is closing it can 4537 * result in kernel memory corruption or kernel panics. 4538 * 4539 * Note that is it up to the module/driver to ensure that it itself 4540 * does not have any stale references to the closing queues once its close 4541 * routine returns. This includes: 4542 * - Cancelling any timeout/bufcall/qtimeout/qbufcall callback routines 4543 * associated with the queues. For timeout and bufcall callbacks the 4544 * module/driver also has to ensure (or wait for) any callbacks that 4545 * are in progress. 4546 * - If the module/driver is using esballoc it has to ensure that any 4547 * esballoc free functions do not refer to a queue that has closed. 4548 * (Note that in general the close routine can not wait for the esballoc'ed 4549 * messages to be freed since that can cause a deadlock.) 4550 * - Cancelling any interrupts that refer to the closing queues and 4551 * also ensuring that there are no interrupts in progress that will 4552 * refer to the closing queues once the close routine returns. 4553 * - For multiplexors removing any driver global state that refers to 4554 * the closing queue and also ensuring that there are no threads in 4555 * the multiplexor that has picked up a queue pointer but not yet 4556 * finished using it. 4557 * 4558 * In addition, a driver/module can only reference the q_next pointer 4559 * in its open, close, put, or service procedures or in a 4560 * qtimeout/qbufcall callback procedure executing "on" the correct 4561 * stream. Thus it can not reference the q_next pointer in an interrupt 4562 * routine or a timeout, bufcall or esballoc callback routine. Likewise 4563 * it can not reference q_next of a different queue e.g. in a mux that 4564 * passes messages from one queues put/service procedure to another queue. 4565 * In all the cases when the driver/module can not access the q_next 4566 * field it must use the *next* versions e.g. canputnext instead of 4567 * canput(q->q_next) and putnextctl instead of putctl(q->q_next, ...). 4568 * 4569 * 4570 * Assuming that the driver/module conforms to the above constraints 4571 * the STREAMS framework has to avoid stale references to q_next for all 4572 * the framework internal cases which include (but are not limited to): 4573 * - Threads in canput/canputnext/backenable and elsewhere that are 4574 * walking q_next. 4575 * - Messages on a syncq that have a reference to the queue through b_queue. 4576 * - Messages on an outer perimeter (syncq) that have a reference to the 4577 * queue through b_queue. 4578 * - Threads that use q_nfsrv (e.g. canput) to find a queue. 4579 * Note that only canput and bcanput use q_nfsrv without any locking. 4580 * 4581 * The STREAMS framework providing the qprocsoff(9F) guarantees means that 4582 * after qprocsoff returns, the framework has to ensure that no threads can 4583 * enter the put or service routines for the closing read or write-side queue. 4584 * In addition to preventing "direct" entry into the put procedures 4585 * the framework also has to prevent messages being drained from 4586 * the syncq or the outer perimeter. 4587 * XXX Note that currently qdetach does relies on D_MTOCEXCL as the only 4588 * mechanism to prevent qwriter(PERIM_OUTER) from running after 4589 * qprocsoff has returned. 4590 * Note that if a module/driver uses put(9F) on one of its own queues 4591 * it is up to the module/driver to ensure that the put() doesn't 4592 * get called when the queue is closing. 4593 * 4594 * 4595 * The framework aspects of the above "contract" is implemented by 4596 * qprocsoff, removeq, and strlock: 4597 * - qprocsoff (disable_svc) sets QWCLOSE to prevent runservice from 4598 * entering the service procedures. 4599 * - strlock acquires the sd_lock and sd_reflock to prevent putnext, 4600 * canputnext, backenable etc from dereferencing the q_next that will 4601 * soon change. 4602 * - strlock waits for sd_refcnt to be zero to wait for e.g. any canputnext 4603 * or other q_next walker that uses claimstr/releasestr to finish. 4604 * - optionally for every syncq in the stream strlock acquires all the 4605 * sq_lock's and waits for all sq_counts to drop to a value that indicates 4606 * that no thread executes in the put or service procedures and that no 4607 * thread is draining into the module/driver. This ensures that no 4608 * open, close, put, service, or qtimeout/qbufcall callback procedure is 4609 * currently executing hence no such thread can end up with the old stale 4610 * q_next value and no canput/backenable can have the old stale 4611 * q_nfsrv/q_next. 4612 * - qdetach (wait_svc) makes sure that any scheduled or running threads 4613 * have either finished or observed the QWCLOSE flag and gone away. 4614 */ 4615 4616 4617 /* 4618 * Get all the locks necessary to change q_next. 4619 * 4620 * Wait for sd_refcnt to reach 0 and, if sqlist is present, wait for the 4621 * sq_count of each syncq in the list to drop to sq_rmqcount, indicating that 4622 * the only threads inside the syncq are threads currently calling removeq(). 4623 * Since threads calling removeq() are in the process of removing their queues 4624 * from the stream, we do not need to worry about them accessing a stale q_next 4625 * pointer and thus we do not need to wait for them to exit (in fact, waiting 4626 * for them can cause deadlock). 4627 * 4628 * This routine is subject to starvation since it does not set any flag to 4629 * prevent threads from entering a module in the stream (i.e. sq_count can 4630 * increase on some syncq while it is waiting on some other syncq). 4631 * 4632 * Assumes that only one thread attempts to call strlock for a given 4633 * stream. If this is not the case the two threads would deadlock. 4634 * This assumption is guaranteed since strlock is only called by insertq 4635 * and removeq and streams plumbing changes are single-threaded for 4636 * a given stream using the STWOPEN, STRCLOSE, and STRPLUMB flags. 4637 * 4638 * For pipes, it is not difficult to atomically designate a pair of streams 4639 * to be mated. Once mated atomically by the framework the twisted pair remain 4640 * configured that way until dismantled atomically by the framework. 4641 * When plumbing takes place on a twisted stream it is necessary to ensure that 4642 * this operation is done exclusively on the twisted stream since two such 4643 * operations, each initiated on different ends of the pipe will deadlock 4644 * waiting for each other to complete. 4645 * 4646 * On entry, no locks should be held. 4647 * The locks acquired and held by strlock depends on a few factors. 4648 * - If sqlist is non-NULL all the syncq locks in the sqlist will be acquired 4649 * and held on exit and all sq_count are at an acceptable level. 4650 * - In all cases, sd_lock and sd_reflock are acquired and held on exit with 4651 * sd_refcnt being zero. 4652 */ 4653 4654 static void 4655 strlock(struct stdata *stp, sqlist_t *sqlist) 4656 { 4657 syncql_t *sql, *sql2; 4658 retry: 4659 /* 4660 * Wait for any claimstr to go away. 4661 */ 4662 if (STRMATED(stp)) { 4663 struct stdata *stp1, *stp2; 4664 4665 STRLOCKMATES(stp); 4666 /* 4667 * Note that the selection of locking order is not 4668 * important, just that they are always acquired in 4669 * the same order. To assure this, we choose this 4670 * order based on the value of the pointer, and since 4671 * the pointer will not change for the life of this 4672 * pair, we will always grab the locks in the same 4673 * order (and hence, prevent deadlocks). 4674 */ 4675 if (&(stp->sd_lock) > &((stp->sd_mate)->sd_lock)) { 4676 stp1 = stp; 4677 stp2 = stp->sd_mate; 4678 } else { 4679 stp2 = stp; 4680 stp1 = stp->sd_mate; 4681 } 4682 mutex_enter(&stp1->sd_reflock); 4683 if (stp1->sd_refcnt > 0) { 4684 STRUNLOCKMATES(stp); 4685 cv_wait(&stp1->sd_refmonitor, &stp1->sd_reflock); 4686 mutex_exit(&stp1->sd_reflock); 4687 goto retry; 4688 } 4689 mutex_enter(&stp2->sd_reflock); 4690 if (stp2->sd_refcnt > 0) { 4691 STRUNLOCKMATES(stp); 4692 mutex_exit(&stp1->sd_reflock); 4693 cv_wait(&stp2->sd_refmonitor, &stp2->sd_reflock); 4694 mutex_exit(&stp2->sd_reflock); 4695 goto retry; 4696 } 4697 STREAM_PUTLOCKS_ENTER(stp1); 4698 STREAM_PUTLOCKS_ENTER(stp2); 4699 } else { 4700 mutex_enter(&stp->sd_lock); 4701 mutex_enter(&stp->sd_reflock); 4702 while (stp->sd_refcnt > 0) { 4703 mutex_exit(&stp->sd_lock); 4704 cv_wait(&stp->sd_refmonitor, &stp->sd_reflock); 4705 if (mutex_tryenter(&stp->sd_lock) == 0) { 4706 mutex_exit(&stp->sd_reflock); 4707 mutex_enter(&stp->sd_lock); 4708 mutex_enter(&stp->sd_reflock); 4709 } 4710 } 4711 STREAM_PUTLOCKS_ENTER(stp); 4712 } 4713 4714 if (sqlist == NULL) 4715 return; 4716 4717 for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { 4718 syncq_t *sq = sql->sql_sq; 4719 uint16_t count; 4720 4721 mutex_enter(SQLOCK(sq)); 4722 count = sq->sq_count; 4723 ASSERT(sq->sq_rmqcount <= count); 4724 SQ_PUTLOCKS_ENTER(sq); 4725 SUM_SQ_PUTCOUNTS(sq, count); 4726 if (count == sq->sq_rmqcount) 4727 continue; 4728 4729 /* Failed - drop all locks that we have acquired so far */ 4730 if (STRMATED(stp)) { 4731 STREAM_PUTLOCKS_EXIT(stp); 4732 STREAM_PUTLOCKS_EXIT(stp->sd_mate); 4733 STRUNLOCKMATES(stp); 4734 mutex_exit(&stp->sd_reflock); 4735 mutex_exit(&stp->sd_mate->sd_reflock); 4736 } else { 4737 STREAM_PUTLOCKS_EXIT(stp); 4738 mutex_exit(&stp->sd_lock); 4739 mutex_exit(&stp->sd_reflock); 4740 } 4741 for (sql2 = sqlist->sqlist_head; sql2 != sql; 4742 sql2 = sql2->sql_next) { 4743 SQ_PUTLOCKS_EXIT(sql2->sql_sq); 4744 mutex_exit(SQLOCK(sql2->sql_sq)); 4745 } 4746 4747 /* 4748 * The wait loop below may starve when there are many threads 4749 * claiming the syncq. This is especially a problem with permod 4750 * syncqs (IP). To lessen the impact of the problem we increment 4751 * sq_needexcl and clear fastbits so that putnexts will slow 4752 * down and call sqenable instead of draining right away. 4753 */ 4754 sq->sq_needexcl++; 4755 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 4756 while (count > sq->sq_rmqcount) { 4757 sq->sq_flags |= SQ_WANTWAKEUP; 4758 SQ_PUTLOCKS_EXIT(sq); 4759 cv_wait(&sq->sq_wait, SQLOCK(sq)); 4760 count = sq->sq_count; 4761 SQ_PUTLOCKS_ENTER(sq); 4762 SUM_SQ_PUTCOUNTS(sq, count); 4763 } 4764 sq->sq_needexcl--; 4765 if (sq->sq_needexcl == 0) 4766 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 4767 SQ_PUTLOCKS_EXIT(sq); 4768 ASSERT(count == sq->sq_rmqcount); 4769 mutex_exit(SQLOCK(sq)); 4770 goto retry; 4771 } 4772 } 4773 4774 /* 4775 * Drop all the locks that strlock acquired. 4776 */ 4777 static void 4778 strunlock(struct stdata *stp, sqlist_t *sqlist) 4779 { 4780 syncql_t *sql; 4781 4782 if (STRMATED(stp)) { 4783 STREAM_PUTLOCKS_EXIT(stp); 4784 STREAM_PUTLOCKS_EXIT(stp->sd_mate); 4785 STRUNLOCKMATES(stp); 4786 mutex_exit(&stp->sd_reflock); 4787 mutex_exit(&stp->sd_mate->sd_reflock); 4788 } else { 4789 STREAM_PUTLOCKS_EXIT(stp); 4790 mutex_exit(&stp->sd_lock); 4791 mutex_exit(&stp->sd_reflock); 4792 } 4793 4794 if (sqlist == NULL) 4795 return; 4796 4797 for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { 4798 SQ_PUTLOCKS_EXIT(sql->sql_sq); 4799 mutex_exit(SQLOCK(sql->sql_sq)); 4800 } 4801 } 4802 4803 /* 4804 * When the module has service procedure, we need check if the next 4805 * module which has service procedure is in flow control to trigger 4806 * the backenable. 4807 */ 4808 static void 4809 backenable_insertedq(queue_t *q) 4810 { 4811 qband_t *qbp; 4812 4813 claimstr(q); 4814 if (q->q_qinfo->qi_srvp != NULL && q->q_next != NULL) { 4815 if (q->q_next->q_nfsrv->q_flag & QWANTW) 4816 backenable(q, 0); 4817 4818 qbp = q->q_next->q_nfsrv->q_bandp; 4819 for (; qbp != NULL; qbp = qbp->qb_next) 4820 if ((qbp->qb_flag & QB_WANTW) && qbp->qb_first != NULL) 4821 backenable(q, qbp->qb_first->b_band); 4822 } 4823 releasestr(q); 4824 } 4825 4826 /* 4827 * Given two read queues, insert a new single one after another. 4828 * 4829 * This routine acquires all the necessary locks in order to change 4830 * q_next and related pointer using strlock(). 4831 * It depends on the stream head ensuring that there are no concurrent 4832 * insertq or removeq on the same stream. The stream head ensures this 4833 * using the flags STWOPEN, STRCLOSE, and STRPLUMB. 4834 * 4835 * Note that no syncq locks are held during the q_next change. This is 4836 * applied to all streams since, unlike removeq, there is no problem of stale 4837 * pointers when adding a module to the stream. Thus drivers/modules that do a 4838 * canput(rq->q_next) would never get a closed/freed queue pointer even if we 4839 * applied this optimization to all streams. 4840 */ 4841 void 4842 insertq(struct stdata *stp, queue_t *new) 4843 { 4844 queue_t *after; 4845 queue_t *wafter; 4846 queue_t *wnew = _WR(new); 4847 boolean_t have_fifo = B_FALSE; 4848 4849 if (new->q_flag & _QINSERTING) { 4850 ASSERT(stp->sd_vnode->v_type != VFIFO); 4851 after = new->q_next; 4852 wafter = _WR(new->q_next); 4853 } else { 4854 after = _RD(stp->sd_wrq); 4855 wafter = stp->sd_wrq; 4856 } 4857 4858 TRACE_2(TR_FAC_STREAMS_FR, TR_INSERTQ, 4859 "insertq:%p, %p", after, new); 4860 ASSERT(after->q_flag & QREADR); 4861 ASSERT(new->q_flag & QREADR); 4862 4863 strlock(stp, NULL); 4864 4865 /* Do we have a FIFO? */ 4866 if (wafter->q_next == after) { 4867 have_fifo = B_TRUE; 4868 wnew->q_next = new; 4869 } else { 4870 wnew->q_next = wafter->q_next; 4871 } 4872 new->q_next = after; 4873 4874 set_nfsrv_ptr(new, wnew, after, wafter); 4875 /* 4876 * set_nfsrv_ptr() needs to know if this is an insertion or not, 4877 * so only reset this flag after calling it. 4878 */ 4879 new->q_flag &= ~_QINSERTING; 4880 4881 if (have_fifo) { 4882 wafter->q_next = wnew; 4883 } else { 4884 if (wafter->q_next) 4885 _OTHERQ(wafter->q_next)->q_next = new; 4886 wafter->q_next = wnew; 4887 } 4888 4889 set_qend(new); 4890 /* The QEND flag might have to be updated for the upstream guy */ 4891 set_qend(after); 4892 4893 ASSERT(_SAMESTR(new) == O_SAMESTR(new)); 4894 ASSERT(_SAMESTR(wnew) == O_SAMESTR(wnew)); 4895 ASSERT(_SAMESTR(after) == O_SAMESTR(after)); 4896 ASSERT(_SAMESTR(wafter) == O_SAMESTR(wafter)); 4897 strsetuio(stp); 4898 4899 /* 4900 * If this was a module insertion, bump the push count. 4901 */ 4902 if (!(new->q_flag & QISDRV)) 4903 stp->sd_pushcnt++; 4904 4905 strunlock(stp, NULL); 4906 4907 /* check if the write Q needs backenable */ 4908 backenable_insertedq(wnew); 4909 4910 /* check if the read Q needs backenable */ 4911 backenable_insertedq(new); 4912 } 4913 4914 /* 4915 * Given a read queue, unlink it from any neighbors. 4916 * 4917 * This routine acquires all the necessary locks in order to 4918 * change q_next and related pointers and also guard against 4919 * stale references (e.g. through q_next) to the queue that 4920 * is being removed. It also plays part of the role in ensuring 4921 * that the module's/driver's put procedure doesn't get called 4922 * after qprocsoff returns. 4923 * 4924 * Removeq depends on the stream head ensuring that there are 4925 * no concurrent insertq or removeq on the same stream. The 4926 * stream head ensures this using the flags STWOPEN, STRCLOSE and 4927 * STRPLUMB. 4928 * 4929 * The set of locks needed to remove the queue is different in 4930 * different cases: 4931 * 4932 * Acquire sd_lock, sd_reflock, and all the syncq locks in the stream after 4933 * waiting for the syncq reference count to drop to 0 indicating that no 4934 * non-close threads are present anywhere in the stream. This ensures that any 4935 * module/driver can reference q_next in its open, close, put, or service 4936 * procedures. 4937 * 4938 * The sq_rmqcount counter tracks the number of threads inside removeq(). 4939 * strlock() ensures that there is either no threads executing inside perimeter 4940 * or there is only a thread calling qprocsoff(). 4941 * 4942 * strlock() compares the value of sq_count with the number of threads inside 4943 * removeq() and waits until sq_count is equal to sq_rmqcount. We need to wakeup 4944 * any threads waiting in strlock() when the sq_rmqcount increases. 4945 */ 4946 4947 void 4948 removeq(queue_t *qp) 4949 { 4950 queue_t *wqp = _WR(qp); 4951 struct stdata *stp = STREAM(qp); 4952 sqlist_t *sqlist = NULL; 4953 boolean_t isdriver; 4954 int moved; 4955 syncq_t *sq = qp->q_syncq; 4956 syncq_t *wsq = wqp->q_syncq; 4957 4958 ASSERT(stp); 4959 4960 TRACE_2(TR_FAC_STREAMS_FR, TR_REMOVEQ, 4961 "removeq:%p %p", qp, wqp); 4962 ASSERT(qp->q_flag&QREADR); 4963 4964 /* 4965 * For queues using Synchronous streams, we must wait for all threads in 4966 * rwnext() to drain out before proceeding. 4967 */ 4968 if (qp->q_flag & QSYNCSTR) { 4969 /* First, we need wakeup any threads blocked in rwnext() */ 4970 mutex_enter(SQLOCK(sq)); 4971 if (sq->sq_flags & SQ_WANTWAKEUP) { 4972 sq->sq_flags &= ~SQ_WANTWAKEUP; 4973 cv_broadcast(&sq->sq_wait); 4974 } 4975 mutex_exit(SQLOCK(sq)); 4976 4977 if (wsq != sq) { 4978 mutex_enter(SQLOCK(wsq)); 4979 if (wsq->sq_flags & SQ_WANTWAKEUP) { 4980 wsq->sq_flags &= ~SQ_WANTWAKEUP; 4981 cv_broadcast(&wsq->sq_wait); 4982 } 4983 mutex_exit(SQLOCK(wsq)); 4984 } 4985 4986 mutex_enter(QLOCK(qp)); 4987 while (qp->q_rwcnt > 0) { 4988 qp->q_flag |= QWANTRMQSYNC; 4989 cv_wait(&qp->q_wait, QLOCK(qp)); 4990 } 4991 mutex_exit(QLOCK(qp)); 4992 4993 mutex_enter(QLOCK(wqp)); 4994 while (wqp->q_rwcnt > 0) { 4995 wqp->q_flag |= QWANTRMQSYNC; 4996 cv_wait(&wqp->q_wait, QLOCK(wqp)); 4997 } 4998 mutex_exit(QLOCK(wqp)); 4999 } 5000 5001 mutex_enter(SQLOCK(sq)); 5002 sq->sq_rmqcount++; 5003 if (sq->sq_flags & SQ_WANTWAKEUP) { 5004 sq->sq_flags &= ~SQ_WANTWAKEUP; 5005 cv_broadcast(&sq->sq_wait); 5006 } 5007 mutex_exit(SQLOCK(sq)); 5008 5009 isdriver = (qp->q_flag & QISDRV); 5010 5011 sqlist = sqlist_build(qp, stp, STRMATED(stp)); 5012 strlock(stp, sqlist); 5013 5014 reset_nfsrv_ptr(qp, wqp); 5015 5016 ASSERT(wqp->q_next == NULL || backq(qp)->q_next == qp); 5017 ASSERT(qp->q_next == NULL || backq(wqp)->q_next == wqp); 5018 /* Do we have a FIFO? */ 5019 if (wqp->q_next == qp) { 5020 stp->sd_wrq->q_next = _RD(stp->sd_wrq); 5021 } else { 5022 if (wqp->q_next) 5023 backq(qp)->q_next = qp->q_next; 5024 if (qp->q_next) 5025 backq(wqp)->q_next = wqp->q_next; 5026 } 5027 5028 /* The QEND flag might have to be updated for the upstream guy */ 5029 if (qp->q_next) 5030 set_qend(qp->q_next); 5031 5032 ASSERT(_SAMESTR(stp->sd_wrq) == O_SAMESTR(stp->sd_wrq)); 5033 ASSERT(_SAMESTR(_RD(stp->sd_wrq)) == O_SAMESTR(_RD(stp->sd_wrq))); 5034 5035 /* 5036 * Move any messages destined for the put procedures to the next 5037 * syncq in line. Otherwise free them. 5038 */ 5039 moved = 0; 5040 /* 5041 * Quick check to see whether there are any messages or events. 5042 */ 5043 if (qp->q_syncqmsgs != 0 || (qp->q_syncq->sq_flags & SQ_EVENTS)) 5044 moved += propagate_syncq(qp); 5045 if (wqp->q_syncqmsgs != 0 || 5046 (wqp->q_syncq->sq_flags & SQ_EVENTS)) 5047 moved += propagate_syncq(wqp); 5048 5049 strsetuio(stp); 5050 5051 /* 5052 * If this was a module removal, decrement the push count. 5053 */ 5054 if (!isdriver) 5055 stp->sd_pushcnt--; 5056 5057 strunlock(stp, sqlist); 5058 sqlist_free(sqlist); 5059 5060 /* 5061 * Make sure any messages that were propagated are drained. 5062 * Also clear any QFULL bit caused by messages that were propagated. 5063 */ 5064 5065 if (qp->q_next != NULL) { 5066 clr_qfull(qp); 5067 /* 5068 * For the driver calling qprocsoff, propagate_syncq 5069 * frees all the messages instead of putting it in 5070 * the stream head 5071 */ 5072 if (!isdriver && (moved > 0)) 5073 emptysq(qp->q_next->q_syncq); 5074 } 5075 if (wqp->q_next != NULL) { 5076 clr_qfull(wqp); 5077 /* 5078 * We come here for any pop of a module except for the 5079 * case of driver being removed. We don't call emptysq 5080 * if we did not move any messages. This will avoid holding 5081 * PERMOD syncq locks in emptysq 5082 */ 5083 if (moved > 0) 5084 emptysq(wqp->q_next->q_syncq); 5085 } 5086 5087 mutex_enter(SQLOCK(sq)); 5088 sq->sq_rmqcount--; 5089 mutex_exit(SQLOCK(sq)); 5090 } 5091 5092 /* 5093 * Prevent further entry by setting a flag (like SQ_FROZEN, SQ_BLOCKED or 5094 * SQ_WRITER) on a syncq. 5095 * If maxcnt is not -1 it assumes that caller has "maxcnt" claim(s) on the 5096 * sync queue and waits until sq_count reaches maxcnt. 5097 * 5098 * If maxcnt is -1 there's no need to grab sq_putlocks since the caller 5099 * does not care about putnext threads that are in the middle of calling put 5100 * entry points. 5101 * 5102 * This routine is used for both inner and outer syncqs. 5103 */ 5104 static void 5105 blocksq(syncq_t *sq, ushort_t flag, int maxcnt) 5106 { 5107 uint16_t count = 0; 5108 5109 mutex_enter(SQLOCK(sq)); 5110 /* 5111 * Wait for SQ_FROZEN/SQ_BLOCKED to be reset. 5112 * SQ_FROZEN will be set if there is a frozen stream that has a 5113 * queue which also refers to this "shared" syncq. 5114 * SQ_BLOCKED will be set if there is "off" queue which also 5115 * refers to this "shared" syncq. 5116 */ 5117 if (maxcnt != -1) { 5118 count = sq->sq_count; 5119 SQ_PUTLOCKS_ENTER(sq); 5120 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 5121 SUM_SQ_PUTCOUNTS(sq, count); 5122 } 5123 sq->sq_needexcl++; 5124 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 5125 5126 while ((sq->sq_flags & flag) || 5127 (maxcnt != -1 && count > (unsigned)maxcnt)) { 5128 sq->sq_flags |= SQ_WANTWAKEUP; 5129 if (maxcnt != -1) { 5130 SQ_PUTLOCKS_EXIT(sq); 5131 } 5132 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5133 if (maxcnt != -1) { 5134 count = sq->sq_count; 5135 SQ_PUTLOCKS_ENTER(sq); 5136 SUM_SQ_PUTCOUNTS(sq, count); 5137 } 5138 } 5139 sq->sq_needexcl--; 5140 sq->sq_flags |= flag; 5141 ASSERT(maxcnt == -1 || count == maxcnt); 5142 if (maxcnt != -1) { 5143 if (sq->sq_needexcl == 0) { 5144 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 5145 } 5146 SQ_PUTLOCKS_EXIT(sq); 5147 } else if (sq->sq_needexcl == 0) { 5148 SQ_PUTCOUNT_SETFAST(sq); 5149 } 5150 5151 mutex_exit(SQLOCK(sq)); 5152 } 5153 5154 /* 5155 * Reset a flag that was set with blocksq. 5156 * 5157 * Can not use this routine to reset SQ_WRITER. 5158 * 5159 * If "isouter" is set then the syncq is assumed to be an outer perimeter 5160 * and drain_syncq is not called. Instead we rely on the qwriter_outer thread 5161 * to handle the queued qwriter operations. 5162 * 5163 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5164 * sq_putlocks are used. 5165 */ 5166 static void 5167 unblocksq(syncq_t *sq, uint16_t resetflag, int isouter) 5168 { 5169 uint16_t flags; 5170 5171 mutex_enter(SQLOCK(sq)); 5172 ASSERT(resetflag != SQ_WRITER); 5173 ASSERT(sq->sq_flags & resetflag); 5174 flags = sq->sq_flags & ~resetflag; 5175 sq->sq_flags = flags; 5176 if (flags & (SQ_QUEUED | SQ_WANTWAKEUP)) { 5177 if (flags & SQ_WANTWAKEUP) { 5178 flags &= ~SQ_WANTWAKEUP; 5179 cv_broadcast(&sq->sq_wait); 5180 } 5181 sq->sq_flags = flags; 5182 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5183 if (!isouter) { 5184 /* drain_syncq drops SQLOCK */ 5185 drain_syncq(sq); 5186 return; 5187 } 5188 } 5189 } 5190 mutex_exit(SQLOCK(sq)); 5191 } 5192 5193 /* 5194 * Reset a flag that was set with blocksq. 5195 * Does not drain the syncq. Use emptysq() for that. 5196 * Returns 1 if SQ_QUEUED is set. Otherwise 0. 5197 * 5198 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5199 * sq_putlocks are used. 5200 */ 5201 static int 5202 dropsq(syncq_t *sq, uint16_t resetflag) 5203 { 5204 uint16_t flags; 5205 5206 mutex_enter(SQLOCK(sq)); 5207 ASSERT(sq->sq_flags & resetflag); 5208 flags = sq->sq_flags & ~resetflag; 5209 if (flags & SQ_WANTWAKEUP) { 5210 flags &= ~SQ_WANTWAKEUP; 5211 cv_broadcast(&sq->sq_wait); 5212 } 5213 sq->sq_flags = flags; 5214 mutex_exit(SQLOCK(sq)); 5215 if (flags & SQ_QUEUED) 5216 return (1); 5217 return (0); 5218 } 5219 5220 /* 5221 * Empty all the messages on a syncq. 5222 * 5223 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5224 * sq_putlocks are used. 5225 */ 5226 static void 5227 emptysq(syncq_t *sq) 5228 { 5229 uint16_t flags; 5230 5231 mutex_enter(SQLOCK(sq)); 5232 flags = sq->sq_flags; 5233 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5234 /* 5235 * To prevent potential recursive invocation of drain_syncq we 5236 * do not call drain_syncq if count is non-zero. 5237 */ 5238 if (sq->sq_count == 0) { 5239 /* drain_syncq() drops SQLOCK */ 5240 drain_syncq(sq); 5241 return; 5242 } else 5243 sqenable(sq); 5244 } 5245 mutex_exit(SQLOCK(sq)); 5246 } 5247 5248 /* 5249 * Ordered insert while removing duplicates. 5250 */ 5251 static void 5252 sqlist_insert(sqlist_t *sqlist, syncq_t *sqp) 5253 { 5254 syncql_t *sqlp, **prev_sqlpp, *new_sqlp; 5255 5256 prev_sqlpp = &sqlist->sqlist_head; 5257 while ((sqlp = *prev_sqlpp) != NULL) { 5258 if (sqlp->sql_sq >= sqp) { 5259 if (sqlp->sql_sq == sqp) /* duplicate */ 5260 return; 5261 break; 5262 } 5263 prev_sqlpp = &sqlp->sql_next; 5264 } 5265 new_sqlp = &sqlist->sqlist_array[sqlist->sqlist_index++]; 5266 ASSERT((char *)new_sqlp < (char *)sqlist + sqlist->sqlist_size); 5267 new_sqlp->sql_next = sqlp; 5268 new_sqlp->sql_sq = sqp; 5269 *prev_sqlpp = new_sqlp; 5270 } 5271 5272 /* 5273 * Walk the write side queues until we hit either the driver 5274 * or a twist in the stream (_SAMESTR will return false in both 5275 * these cases) then turn around and walk the read side queues 5276 * back up to the stream head. 5277 */ 5278 static void 5279 sqlist_insertall(sqlist_t *sqlist, queue_t *q) 5280 { 5281 while (q != NULL) { 5282 sqlist_insert(sqlist, q->q_syncq); 5283 5284 if (_SAMESTR(q)) 5285 q = q->q_next; 5286 else if (!(q->q_flag & QREADR)) 5287 q = _RD(q); 5288 else 5289 q = NULL; 5290 } 5291 } 5292 5293 /* 5294 * Allocate and build a list of all syncqs in a stream and the syncq(s) 5295 * associated with the "q" parameter. The resulting list is sorted in a 5296 * canonical order and is free of duplicates. 5297 * Assumes the passed queue is a _RD(q). 5298 */ 5299 static sqlist_t * 5300 sqlist_build(queue_t *q, struct stdata *stp, boolean_t do_twist) 5301 { 5302 sqlist_t *sqlist = sqlist_alloc(stp, KM_SLEEP); 5303 5304 /* 5305 * start with the current queue/qpair 5306 */ 5307 ASSERT(q->q_flag & QREADR); 5308 5309 sqlist_insert(sqlist, q->q_syncq); 5310 sqlist_insert(sqlist, _WR(q)->q_syncq); 5311 5312 sqlist_insertall(sqlist, stp->sd_wrq); 5313 if (do_twist) 5314 sqlist_insertall(sqlist, stp->sd_mate->sd_wrq); 5315 5316 return (sqlist); 5317 } 5318 5319 static sqlist_t * 5320 sqlist_alloc(struct stdata *stp, int kmflag) 5321 { 5322 size_t sqlist_size; 5323 sqlist_t *sqlist; 5324 5325 /* 5326 * Allocate 2 syncql_t's for each pushed module. Note that 5327 * the sqlist_t structure already has 4 syncql_t's built in: 5328 * 2 for the stream head, and 2 for the driver/other stream head. 5329 */ 5330 sqlist_size = 2 * sizeof (syncql_t) * stp->sd_pushcnt + 5331 sizeof (sqlist_t); 5332 if (STRMATED(stp)) 5333 sqlist_size += 2 * sizeof (syncql_t) * stp->sd_mate->sd_pushcnt; 5334 sqlist = kmem_alloc(sqlist_size, kmflag); 5335 5336 sqlist->sqlist_head = NULL; 5337 sqlist->sqlist_size = sqlist_size; 5338 sqlist->sqlist_index = 0; 5339 5340 return (sqlist); 5341 } 5342 5343 /* 5344 * Free the list created by sqlist_alloc() 5345 */ 5346 static void 5347 sqlist_free(sqlist_t *sqlist) 5348 { 5349 kmem_free(sqlist, sqlist->sqlist_size); 5350 } 5351 5352 /* 5353 * Prevent any new entries into any syncq in this stream. 5354 * Used by freezestr. 5355 */ 5356 void 5357 strblock(queue_t *q) 5358 { 5359 struct stdata *stp; 5360 syncql_t *sql; 5361 sqlist_t *sqlist; 5362 5363 q = _RD(q); 5364 5365 stp = STREAM(q); 5366 ASSERT(stp != NULL); 5367 5368 /* 5369 * Get a sorted list with all the duplicates removed containing 5370 * all the syncqs referenced by this stream. 5371 */ 5372 sqlist = sqlist_build(q, stp, B_FALSE); 5373 for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) 5374 blocksq(sql->sql_sq, SQ_FROZEN, -1); 5375 sqlist_free(sqlist); 5376 } 5377 5378 /* 5379 * Release the block on new entries into this stream 5380 */ 5381 void 5382 strunblock(queue_t *q) 5383 { 5384 struct stdata *stp; 5385 syncql_t *sql; 5386 sqlist_t *sqlist; 5387 int drain_needed; 5388 5389 q = _RD(q); 5390 5391 /* 5392 * Get a sorted list with all the duplicates removed containing 5393 * all the syncqs referenced by this stream. 5394 * Have to drop the SQ_FROZEN flag on all the syncqs before 5395 * starting to drain them; otherwise the draining might 5396 * cause a freezestr in some module on the stream (which 5397 * would deadlock). 5398 */ 5399 stp = STREAM(q); 5400 ASSERT(stp != NULL); 5401 sqlist = sqlist_build(q, stp, B_FALSE); 5402 drain_needed = 0; 5403 for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) 5404 drain_needed += dropsq(sql->sql_sq, SQ_FROZEN); 5405 if (drain_needed) { 5406 for (sql = sqlist->sqlist_head; sql != NULL; 5407 sql = sql->sql_next) 5408 emptysq(sql->sql_sq); 5409 } 5410 sqlist_free(sqlist); 5411 } 5412 5413 #ifdef DEBUG 5414 static int 5415 qprocsareon(queue_t *rq) 5416 { 5417 if (rq->q_next == NULL) 5418 return (0); 5419 return (_WR(rq->q_next)->q_next == _WR(rq)); 5420 } 5421 5422 int 5423 qclaimed(queue_t *q) 5424 { 5425 uint_t count; 5426 5427 count = q->q_syncq->sq_count; 5428 SUM_SQ_PUTCOUNTS(q->q_syncq, count); 5429 return (count != 0); 5430 } 5431 5432 /* 5433 * Check if anyone has frozen this stream with freezestr 5434 */ 5435 int 5436 frozenstr(queue_t *q) 5437 { 5438 return ((q->q_syncq->sq_flags & SQ_FROZEN) != 0); 5439 } 5440 #endif /* DEBUG */ 5441 5442 /* 5443 * Enter a queue. 5444 * Obsoleted interface. Should not be used. 5445 */ 5446 void 5447 enterq(queue_t *q) 5448 { 5449 entersq(q->q_syncq, SQ_CALLBACK); 5450 } 5451 5452 void 5453 leaveq(queue_t *q) 5454 { 5455 leavesq(q->q_syncq, SQ_CALLBACK); 5456 } 5457 5458 /* 5459 * Enter a perimeter. c_inner and c_outer specifies which concurrency bits 5460 * to check. 5461 * Wait if SQ_QUEUED is set to preserve ordering between messages and qwriter 5462 * calls and the running of open, close and service procedures. 5463 * 5464 * If c_inner bit is set no need to grab sq_putlocks since we don't care 5465 * if other threads have entered or are entering put entry point. 5466 * 5467 * If c_inner bit is set it might have been possible to use 5468 * sq_putlocks/sq_putcounts instead of SQLOCK/sq_count (e.g. to optimize 5469 * open/close path for IP) but since the count may need to be decremented in 5470 * qwait() we wouldn't know which counter to decrement. Currently counter is 5471 * selected by current cpu_seqid and current CPU can change at any moment. XXX 5472 * in the future we might use curthread id bits to select the counter and this 5473 * would stay constant across routine calls. 5474 */ 5475 void 5476 entersq(syncq_t *sq, int entrypoint) 5477 { 5478 uint16_t count = 0; 5479 uint16_t flags; 5480 uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; 5481 uint16_t type; 5482 uint_t c_inner = entrypoint & SQ_CI; 5483 uint_t c_outer = entrypoint & SQ_CO; 5484 5485 /* 5486 * Increment ref count to keep closes out of this queue. 5487 */ 5488 ASSERT(sq); 5489 ASSERT(c_inner && c_outer); 5490 mutex_enter(SQLOCK(sq)); 5491 flags = sq->sq_flags; 5492 type = sq->sq_type; 5493 if (!(type & c_inner)) { 5494 /* Make sure all putcounts now use slowlock. */ 5495 count = sq->sq_count; 5496 SQ_PUTLOCKS_ENTER(sq); 5497 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 5498 SUM_SQ_PUTCOUNTS(sq, count); 5499 sq->sq_needexcl++; 5500 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 5501 waitflags |= SQ_MESSAGES; 5502 } 5503 /* 5504 * Wait until we can enter the inner perimeter. 5505 * If we want exclusive access we wait until sq_count is 0. 5506 * We have to do this before entering the outer perimeter in order 5507 * to preserve put/close message ordering. 5508 */ 5509 while ((flags & waitflags) || (!(type & c_inner) && count != 0)) { 5510 sq->sq_flags = flags | SQ_WANTWAKEUP; 5511 if (!(type & c_inner)) { 5512 SQ_PUTLOCKS_EXIT(sq); 5513 } 5514 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5515 if (!(type & c_inner)) { 5516 count = sq->sq_count; 5517 SQ_PUTLOCKS_ENTER(sq); 5518 SUM_SQ_PUTCOUNTS(sq, count); 5519 } 5520 flags = sq->sq_flags; 5521 } 5522 5523 if (!(type & c_inner)) { 5524 ASSERT(sq->sq_needexcl > 0); 5525 sq->sq_needexcl--; 5526 if (sq->sq_needexcl == 0) { 5527 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 5528 } 5529 } 5530 5531 /* Check if we need to enter the outer perimeter */ 5532 if (!(type & c_outer)) { 5533 /* 5534 * We have to enter the outer perimeter exclusively before 5535 * we can increment sq_count to avoid deadlock. This implies 5536 * that we have to re-check sq_flags and sq_count. 5537 * 5538 * is it possible to have c_inner set when c_outer is not set? 5539 */ 5540 if (!(type & c_inner)) { 5541 SQ_PUTLOCKS_EXIT(sq); 5542 } 5543 mutex_exit(SQLOCK(sq)); 5544 outer_enter(sq->sq_outer, SQ_GOAWAY); 5545 mutex_enter(SQLOCK(sq)); 5546 flags = sq->sq_flags; 5547 /* 5548 * there should be no need to recheck sq_putcounts 5549 * because outer_enter() has already waited for them to clear 5550 * after setting SQ_WRITER. 5551 */ 5552 count = sq->sq_count; 5553 #ifdef DEBUG 5554 /* 5555 * SUMCHECK_SQ_PUTCOUNTS should return the sum instead 5556 * of doing an ASSERT internally. Others should do 5557 * something like 5558 * ASSERT(SUMCHECK_SQ_PUTCOUNTS(sq) == 0); 5559 * without the need to #ifdef DEBUG it. 5560 */ 5561 SUMCHECK_SQ_PUTCOUNTS(sq, 0); 5562 #endif 5563 while ((flags & (SQ_EXCL|SQ_BLOCKED|SQ_FROZEN)) || 5564 (!(type & c_inner) && count != 0)) { 5565 sq->sq_flags = flags | SQ_WANTWAKEUP; 5566 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5567 count = sq->sq_count; 5568 flags = sq->sq_flags; 5569 } 5570 } 5571 5572 sq->sq_count++; 5573 ASSERT(sq->sq_count != 0); /* Wraparound */ 5574 if (!(type & c_inner)) { 5575 /* Exclusive entry */ 5576 ASSERT(sq->sq_count == 1); 5577 sq->sq_flags |= SQ_EXCL; 5578 if (type & c_outer) { 5579 SQ_PUTLOCKS_EXIT(sq); 5580 } 5581 } 5582 mutex_exit(SQLOCK(sq)); 5583 } 5584 5585 /* 5586 * Leave a syncq. Announce to framework that closes may proceed. 5587 * c_inner and c_outer specify which concurrency bits to check. 5588 * 5589 * Must never be called from driver or module put entry point. 5590 * 5591 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5592 * sq_putlocks are used. 5593 */ 5594 void 5595 leavesq(syncq_t *sq, int entrypoint) 5596 { 5597 uint16_t flags; 5598 uint16_t type; 5599 uint_t c_outer = entrypoint & SQ_CO; 5600 #ifdef DEBUG 5601 uint_t c_inner = entrypoint & SQ_CI; 5602 #endif 5603 5604 /* 5605 * Decrement ref count, drain the syncq if possible, and wake up 5606 * any waiting close. 5607 */ 5608 ASSERT(sq); 5609 ASSERT(c_inner && c_outer); 5610 mutex_enter(SQLOCK(sq)); 5611 flags = sq->sq_flags; 5612 type = sq->sq_type; 5613 if (flags & (SQ_QUEUED|SQ_WANTWAKEUP|SQ_WANTEXWAKEUP)) { 5614 5615 if (flags & SQ_WANTWAKEUP) { 5616 flags &= ~SQ_WANTWAKEUP; 5617 cv_broadcast(&sq->sq_wait); 5618 } 5619 if (flags & SQ_WANTEXWAKEUP) { 5620 flags &= ~SQ_WANTEXWAKEUP; 5621 cv_broadcast(&sq->sq_exitwait); 5622 } 5623 5624 if ((flags & SQ_QUEUED) && !(flags & SQ_STAYAWAY)) { 5625 /* 5626 * The syncq needs to be drained. "Exit" the syncq 5627 * before calling drain_syncq. 5628 */ 5629 ASSERT(sq->sq_count != 0); 5630 sq->sq_count--; 5631 ASSERT((flags & SQ_EXCL) || (type & c_inner)); 5632 sq->sq_flags = flags & ~SQ_EXCL; 5633 drain_syncq(sq); 5634 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 5635 /* Check if we need to exit the outer perimeter */ 5636 /* XXX will this ever be true? */ 5637 if (!(type & c_outer)) 5638 outer_exit(sq->sq_outer); 5639 return; 5640 } 5641 } 5642 ASSERT(sq->sq_count != 0); 5643 sq->sq_count--; 5644 ASSERT((flags & SQ_EXCL) || (type & c_inner)); 5645 sq->sq_flags = flags & ~SQ_EXCL; 5646 mutex_exit(SQLOCK(sq)); 5647 5648 /* Check if we need to exit the outer perimeter */ 5649 if (!(sq->sq_type & c_outer)) 5650 outer_exit(sq->sq_outer); 5651 } 5652 5653 /* 5654 * Prevent q_next from changing in this stream by incrementing sq_count. 5655 * 5656 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5657 * sq_putlocks are used. 5658 */ 5659 void 5660 claimq(queue_t *qp) 5661 { 5662 syncq_t *sq = qp->q_syncq; 5663 5664 mutex_enter(SQLOCK(sq)); 5665 sq->sq_count++; 5666 ASSERT(sq->sq_count != 0); /* Wraparound */ 5667 mutex_exit(SQLOCK(sq)); 5668 } 5669 5670 /* 5671 * Undo claimq. 5672 * 5673 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5674 * sq_putlocks are used. 5675 */ 5676 void 5677 releaseq(queue_t *qp) 5678 { 5679 syncq_t *sq = qp->q_syncq; 5680 uint16_t flags; 5681 5682 mutex_enter(SQLOCK(sq)); 5683 ASSERT(sq->sq_count > 0); 5684 sq->sq_count--; 5685 5686 flags = sq->sq_flags; 5687 if (flags & (SQ_WANTWAKEUP|SQ_QUEUED)) { 5688 if (flags & SQ_WANTWAKEUP) { 5689 flags &= ~SQ_WANTWAKEUP; 5690 cv_broadcast(&sq->sq_wait); 5691 } 5692 sq->sq_flags = flags; 5693 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5694 /* 5695 * To prevent potential recursive invocation of 5696 * drain_syncq we do not call drain_syncq if count is 5697 * non-zero. 5698 */ 5699 if (sq->sq_count == 0) { 5700 drain_syncq(sq); 5701 return; 5702 } else 5703 sqenable(sq); 5704 } 5705 } 5706 mutex_exit(SQLOCK(sq)); 5707 } 5708 5709 /* 5710 * Prevent q_next from changing in this stream by incrementing sd_refcnt. 5711 */ 5712 void 5713 claimstr(queue_t *qp) 5714 { 5715 struct stdata *stp = STREAM(qp); 5716 5717 mutex_enter(&stp->sd_reflock); 5718 stp->sd_refcnt++; 5719 ASSERT(stp->sd_refcnt != 0); /* Wraparound */ 5720 mutex_exit(&stp->sd_reflock); 5721 } 5722 5723 /* 5724 * Undo claimstr. 5725 */ 5726 void 5727 releasestr(queue_t *qp) 5728 { 5729 struct stdata *stp = STREAM(qp); 5730 5731 mutex_enter(&stp->sd_reflock); 5732 ASSERT(stp->sd_refcnt != 0); 5733 if (--stp->sd_refcnt == 0) 5734 cv_broadcast(&stp->sd_refmonitor); 5735 mutex_exit(&stp->sd_reflock); 5736 } 5737 5738 static syncq_t * 5739 new_syncq(void) 5740 { 5741 return (kmem_cache_alloc(syncq_cache, KM_SLEEP)); 5742 } 5743 5744 static void 5745 free_syncq(syncq_t *sq) 5746 { 5747 ASSERT(sq->sq_head == NULL); 5748 ASSERT(sq->sq_outer == NULL); 5749 ASSERT(sq->sq_callbpend == NULL); 5750 ASSERT((sq->sq_onext == NULL && sq->sq_oprev == NULL) || 5751 (sq->sq_onext == sq && sq->sq_oprev == sq)); 5752 5753 if (sq->sq_ciputctrl != NULL) { 5754 ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); 5755 SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, 5756 sq->sq_nciputctrl, 0); 5757 ASSERT(ciputctrl_cache != NULL); 5758 kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); 5759 } 5760 5761 sq->sq_tail = NULL; 5762 sq->sq_evhead = NULL; 5763 sq->sq_evtail = NULL; 5764 sq->sq_ciputctrl = NULL; 5765 sq->sq_nciputctrl = 0; 5766 sq->sq_count = 0; 5767 sq->sq_rmqcount = 0; 5768 sq->sq_callbflags = 0; 5769 sq->sq_cancelid = 0; 5770 sq->sq_next = NULL; 5771 sq->sq_needexcl = 0; 5772 sq->sq_svcflags = 0; 5773 sq->sq_nqueues = 0; 5774 sq->sq_pri = 0; 5775 sq->sq_onext = NULL; 5776 sq->sq_oprev = NULL; 5777 sq->sq_flags = 0; 5778 sq->sq_type = 0; 5779 sq->sq_servcount = 0; 5780 5781 kmem_cache_free(syncq_cache, sq); 5782 } 5783 5784 /* Outer perimeter code */ 5785 5786 /* 5787 * The outer syncq uses the fields and flags in the syncq slightly 5788 * differently from the inner syncqs. 5789 * sq_count Incremented when there are pending or running 5790 * writers at the outer perimeter to prevent the set of 5791 * inner syncqs that belong to the outer perimeter from 5792 * changing. 5793 * sq_head/tail List of deferred qwriter(OUTER) operations. 5794 * 5795 * SQ_BLOCKED Set to prevent traversing of sq_next,sq_prev while 5796 * inner syncqs are added to or removed from the 5797 * outer perimeter. 5798 * SQ_QUEUED sq_head/tail has messages or events queued. 5799 * 5800 * SQ_WRITER A thread is currently traversing all the inner syncqs 5801 * setting the SQ_WRITER flag. 5802 */ 5803 5804 /* 5805 * Get write access at the outer perimeter. 5806 * Note that read access is done by entersq, putnext, and put by simply 5807 * incrementing sq_count in the inner syncq. 5808 * 5809 * Waits until "flags" is no longer set in the outer to prevent multiple 5810 * threads from having write access at the same time. SQ_WRITER has to be part 5811 * of "flags". 5812 * 5813 * Increases sq_count on the outer syncq to keep away outer_insert/remove 5814 * until the outer_exit is finished. 5815 * 5816 * outer_enter is vulnerable to starvation since it does not prevent new 5817 * threads from entering the inner syncqs while it is waiting for sq_count to 5818 * go to zero. 5819 */ 5820 void 5821 outer_enter(syncq_t *outer, uint16_t flags) 5822 { 5823 syncq_t *sq; 5824 int wait_needed; 5825 uint16_t count; 5826 5827 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5828 outer->sq_oprev != NULL); 5829 ASSERT(flags & SQ_WRITER); 5830 5831 retry: 5832 mutex_enter(SQLOCK(outer)); 5833 while (outer->sq_flags & flags) { 5834 outer->sq_flags |= SQ_WANTWAKEUP; 5835 cv_wait(&outer->sq_wait, SQLOCK(outer)); 5836 } 5837 5838 ASSERT(!(outer->sq_flags & SQ_WRITER)); 5839 outer->sq_flags |= SQ_WRITER; 5840 outer->sq_count++; 5841 ASSERT(outer->sq_count != 0); /* wraparound */ 5842 wait_needed = 0; 5843 /* 5844 * Set SQ_WRITER on all the inner syncqs while holding 5845 * the SQLOCK on the outer syncq. This ensures that the changing 5846 * of SQ_WRITER is atomic under the outer SQLOCK. 5847 */ 5848 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 5849 mutex_enter(SQLOCK(sq)); 5850 count = sq->sq_count; 5851 SQ_PUTLOCKS_ENTER(sq); 5852 sq->sq_flags |= SQ_WRITER; 5853 SUM_SQ_PUTCOUNTS(sq, count); 5854 if (count != 0) 5855 wait_needed = 1; 5856 SQ_PUTLOCKS_EXIT(sq); 5857 mutex_exit(SQLOCK(sq)); 5858 } 5859 mutex_exit(SQLOCK(outer)); 5860 5861 /* 5862 * Get everybody out of the syncqs sequentially. 5863 * Note that we don't actually need to acquire the PUTLOCKS, since 5864 * we have already cleared the fastbit, and set QWRITER. By 5865 * definition, the count can not increase since putnext will 5866 * take the slowlock path (and the purpose of acquiring the 5867 * putlocks was to make sure it didn't increase while we were 5868 * waiting). 5869 * 5870 * Note that we still acquire the PUTLOCKS to be safe. 5871 */ 5872 if (wait_needed) { 5873 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 5874 mutex_enter(SQLOCK(sq)); 5875 count = sq->sq_count; 5876 SQ_PUTLOCKS_ENTER(sq); 5877 SUM_SQ_PUTCOUNTS(sq, count); 5878 while (count != 0) { 5879 sq->sq_flags |= SQ_WANTWAKEUP; 5880 SQ_PUTLOCKS_EXIT(sq); 5881 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5882 count = sq->sq_count; 5883 SQ_PUTLOCKS_ENTER(sq); 5884 SUM_SQ_PUTCOUNTS(sq, count); 5885 } 5886 SQ_PUTLOCKS_EXIT(sq); 5887 mutex_exit(SQLOCK(sq)); 5888 } 5889 /* 5890 * Verify that none of the flags got set while we 5891 * were waiting for the sq_counts to drop. 5892 * If this happens we exit and retry entering the 5893 * outer perimeter. 5894 */ 5895 mutex_enter(SQLOCK(outer)); 5896 if (outer->sq_flags & (flags & ~SQ_WRITER)) { 5897 mutex_exit(SQLOCK(outer)); 5898 outer_exit(outer); 5899 goto retry; 5900 } 5901 mutex_exit(SQLOCK(outer)); 5902 } 5903 } 5904 5905 /* 5906 * Drop the write access at the outer perimeter. 5907 * Read access is dropped implicitly (by putnext, put, and leavesq) by 5908 * decrementing sq_count. 5909 */ 5910 void 5911 outer_exit(syncq_t *outer) 5912 { 5913 syncq_t *sq; 5914 int drain_needed; 5915 uint16_t flags; 5916 5917 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5918 outer->sq_oprev != NULL); 5919 ASSERT(MUTEX_NOT_HELD(SQLOCK(outer))); 5920 5921 /* 5922 * Atomically (from the perspective of threads calling become_writer) 5923 * drop the write access at the outer perimeter by holding 5924 * SQLOCK(outer) across all the dropsq calls and the resetting of 5925 * SQ_WRITER. 5926 * This defines a locking order between the outer perimeter 5927 * SQLOCK and the inner perimeter SQLOCKs. 5928 */ 5929 mutex_enter(SQLOCK(outer)); 5930 flags = outer->sq_flags; 5931 ASSERT(outer->sq_flags & SQ_WRITER); 5932 if (flags & SQ_QUEUED) { 5933 write_now(outer); 5934 flags = outer->sq_flags; 5935 } 5936 5937 /* 5938 * sq_onext is stable since sq_count has not yet been decreased. 5939 * Reset the SQ_WRITER flags in all syncqs. 5940 * After dropping SQ_WRITER on the outer syncq we empty all the 5941 * inner syncqs. 5942 */ 5943 drain_needed = 0; 5944 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) 5945 drain_needed += dropsq(sq, SQ_WRITER); 5946 ASSERT(!(outer->sq_flags & SQ_QUEUED)); 5947 flags &= ~SQ_WRITER; 5948 if (drain_needed) { 5949 outer->sq_flags = flags; 5950 mutex_exit(SQLOCK(outer)); 5951 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) 5952 emptysq(sq); 5953 mutex_enter(SQLOCK(outer)); 5954 flags = outer->sq_flags; 5955 } 5956 if (flags & SQ_WANTWAKEUP) { 5957 flags &= ~SQ_WANTWAKEUP; 5958 cv_broadcast(&outer->sq_wait); 5959 } 5960 outer->sq_flags = flags; 5961 ASSERT(outer->sq_count > 0); 5962 outer->sq_count--; 5963 mutex_exit(SQLOCK(outer)); 5964 } 5965 5966 /* 5967 * Add another syncq to an outer perimeter. 5968 * Block out all other access to the outer perimeter while it is being 5969 * changed using blocksq. 5970 * Assumes that the caller has *not* done an outer_enter. 5971 * 5972 * Vulnerable to starvation in blocksq. 5973 */ 5974 static void 5975 outer_insert(syncq_t *outer, syncq_t *sq) 5976 { 5977 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5978 outer->sq_oprev != NULL); 5979 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 5980 sq->sq_oprev == NULL); /* Can't be in an outer perimeter */ 5981 5982 /* Get exclusive access to the outer perimeter list */ 5983 blocksq(outer, SQ_BLOCKED, 0); 5984 ASSERT(outer->sq_flags & SQ_BLOCKED); 5985 ASSERT(!(outer->sq_flags & SQ_WRITER)); 5986 5987 mutex_enter(SQLOCK(sq)); 5988 sq->sq_outer = outer; 5989 outer->sq_onext->sq_oprev = sq; 5990 sq->sq_onext = outer->sq_onext; 5991 outer->sq_onext = sq; 5992 sq->sq_oprev = outer; 5993 mutex_exit(SQLOCK(sq)); 5994 unblocksq(outer, SQ_BLOCKED, 1); 5995 } 5996 5997 /* 5998 * Remove a syncq from an outer perimeter. 5999 * Block out all other access to the outer perimeter while it is being 6000 * changed using blocksq. 6001 * Assumes that the caller has *not* done an outer_enter. 6002 * 6003 * Vulnerable to starvation in blocksq. 6004 */ 6005 static void 6006 outer_remove(syncq_t *outer, syncq_t *sq) 6007 { 6008 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 6009 outer->sq_oprev != NULL); 6010 ASSERT(sq->sq_outer == outer); 6011 6012 /* Get exclusive access to the outer perimeter list */ 6013 blocksq(outer, SQ_BLOCKED, 0); 6014 ASSERT(outer->sq_flags & SQ_BLOCKED); 6015 ASSERT(!(outer->sq_flags & SQ_WRITER)); 6016 6017 mutex_enter(SQLOCK(sq)); 6018 sq->sq_outer = NULL; 6019 sq->sq_onext->sq_oprev = sq->sq_oprev; 6020 sq->sq_oprev->sq_onext = sq->sq_onext; 6021 sq->sq_oprev = sq->sq_onext = NULL; 6022 mutex_exit(SQLOCK(sq)); 6023 unblocksq(outer, SQ_BLOCKED, 1); 6024 } 6025 6026 /* 6027 * Queue a deferred qwriter(OUTER) callback for this outer perimeter. 6028 * If this is the first callback for this outer perimeter then add 6029 * this outer perimeter to the list of outer perimeters that 6030 * the qwriter_outer_thread will process. 6031 * 6032 * Increments sq_count in the outer syncq to prevent the membership 6033 * of the outer perimeter (in terms of inner syncqs) to change while 6034 * the callback is pending. 6035 */ 6036 static void 6037 queue_writer(syncq_t *outer, void (*func)(), queue_t *q, mblk_t *mp) 6038 { 6039 ASSERT(MUTEX_HELD(SQLOCK(outer))); 6040 6041 mp->b_prev = (mblk_t *)func; 6042 mp->b_queue = q; 6043 mp->b_next = NULL; 6044 outer->sq_count++; /* Decremented when dequeued */ 6045 ASSERT(outer->sq_count != 0); /* Wraparound */ 6046 if (outer->sq_evhead == NULL) { 6047 /* First message. */ 6048 outer->sq_evhead = outer->sq_evtail = mp; 6049 outer->sq_flags |= SQ_EVENTS; 6050 mutex_exit(SQLOCK(outer)); 6051 STRSTAT(qwr_outer); 6052 (void) taskq_dispatch(streams_taskq, 6053 (task_func_t *)qwriter_outer_service, outer, TQ_SLEEP); 6054 } else { 6055 ASSERT(outer->sq_flags & SQ_EVENTS); 6056 outer->sq_evtail->b_next = mp; 6057 outer->sq_evtail = mp; 6058 mutex_exit(SQLOCK(outer)); 6059 } 6060 } 6061 6062 /* 6063 * Try and upgrade to write access at the outer perimeter. If this can 6064 * not be done without blocking then queue the callback to be done 6065 * by the qwriter_outer_thread. 6066 * 6067 * This routine can only be called from put or service procedures plus 6068 * asynchronous callback routines that have properly entered the queue (with 6069 * entersq). Thus qwriter(OUTER) assumes the caller has one claim on the syncq 6070 * associated with q. 6071 */ 6072 void 6073 qwriter_outer(queue_t *q, mblk_t *mp, void (*func)()) 6074 { 6075 syncq_t *osq, *sq, *outer; 6076 int failed; 6077 uint16_t flags; 6078 6079 osq = q->q_syncq; 6080 outer = osq->sq_outer; 6081 if (outer == NULL) 6082 panic("qwriter(PERIM_OUTER): no outer perimeter"); 6083 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 6084 outer->sq_oprev != NULL); 6085 6086 mutex_enter(SQLOCK(outer)); 6087 flags = outer->sq_flags; 6088 /* 6089 * If some thread is traversing sq_next, or if we are blocked by 6090 * outer_insert or outer_remove, or if the we already have queued 6091 * callbacks, then queue this callback for later processing. 6092 * 6093 * Also queue the qwriter for an interrupt thread in order 6094 * to reduce the time spent running at high IPL. 6095 * to identify there are events. 6096 */ 6097 if ((flags & SQ_GOAWAY) || (curthread->t_pri >= kpreemptpri)) { 6098 /* 6099 * Queue the become_writer request. 6100 * The queueing is atomic under SQLOCK(outer) in order 6101 * to synchronize with outer_exit. 6102 * queue_writer will drop the outer SQLOCK 6103 */ 6104 if (flags & SQ_BLOCKED) { 6105 /* Must set SQ_WRITER on inner perimeter */ 6106 mutex_enter(SQLOCK(osq)); 6107 osq->sq_flags |= SQ_WRITER; 6108 mutex_exit(SQLOCK(osq)); 6109 } else { 6110 if (!(flags & SQ_WRITER)) { 6111 /* 6112 * The outer could have been SQ_BLOCKED thus 6113 * SQ_WRITER might not be set on the inner. 6114 */ 6115 mutex_enter(SQLOCK(osq)); 6116 osq->sq_flags |= SQ_WRITER; 6117 mutex_exit(SQLOCK(osq)); 6118 } 6119 ASSERT(osq->sq_flags & SQ_WRITER); 6120 } 6121 queue_writer(outer, func, q, mp); 6122 return; 6123 } 6124 /* 6125 * We are half-way to exclusive access to the outer perimeter. 6126 * Prevent any outer_enter, qwriter(OUTER), or outer_insert/remove 6127 * while the inner syncqs are traversed. 6128 */ 6129 outer->sq_count++; 6130 ASSERT(outer->sq_count != 0); /* wraparound */ 6131 flags |= SQ_WRITER; 6132 /* 6133 * Check if we can run the function immediately. Mark all 6134 * syncqs with the writer flag to prevent new entries into 6135 * put and service procedures. 6136 * 6137 * Set SQ_WRITER on all the inner syncqs while holding 6138 * the SQLOCK on the outer syncq. This ensures that the changing 6139 * of SQ_WRITER is atomic under the outer SQLOCK. 6140 */ 6141 failed = 0; 6142 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 6143 uint16_t count; 6144 uint_t maxcnt = (sq == osq) ? 1 : 0; 6145 6146 mutex_enter(SQLOCK(sq)); 6147 count = sq->sq_count; 6148 SQ_PUTLOCKS_ENTER(sq); 6149 SUM_SQ_PUTCOUNTS(sq, count); 6150 if (sq->sq_count > maxcnt) 6151 failed = 1; 6152 sq->sq_flags |= SQ_WRITER; 6153 SQ_PUTLOCKS_EXIT(sq); 6154 mutex_exit(SQLOCK(sq)); 6155 } 6156 if (failed) { 6157 /* 6158 * Some other thread has a read claim on the outer perimeter. 6159 * Queue the callback for deferred processing. 6160 * 6161 * queue_writer will set SQ_QUEUED before we drop SQ_WRITER 6162 * so that other qwriter(OUTER) calls will queue their 6163 * callbacks as well. queue_writer increments sq_count so we 6164 * decrement to compensate for the our increment. 6165 * 6166 * Dropping SQ_WRITER enables the writer thread to work 6167 * on this outer perimeter. 6168 */ 6169 outer->sq_flags = flags; 6170 queue_writer(outer, func, q, mp); 6171 /* queue_writer dropper the lock */ 6172 mutex_enter(SQLOCK(outer)); 6173 ASSERT(outer->sq_count > 0); 6174 outer->sq_count--; 6175 ASSERT(outer->sq_flags & SQ_WRITER); 6176 flags = outer->sq_flags; 6177 flags &= ~SQ_WRITER; 6178 if (flags & SQ_WANTWAKEUP) { 6179 flags &= ~SQ_WANTWAKEUP; 6180 cv_broadcast(&outer->sq_wait); 6181 } 6182 outer->sq_flags = flags; 6183 mutex_exit(SQLOCK(outer)); 6184 return; 6185 } else { 6186 outer->sq_flags = flags; 6187 mutex_exit(SQLOCK(outer)); 6188 } 6189 6190 /* Can run it immediately */ 6191 (*func)(q, mp); 6192 6193 outer_exit(outer); 6194 } 6195 6196 /* 6197 * Dequeue all writer callbacks from the outer perimeter and run them. 6198 */ 6199 static void 6200 write_now(syncq_t *outer) 6201 { 6202 mblk_t *mp; 6203 queue_t *q; 6204 void (*func)(); 6205 6206 ASSERT(MUTEX_HELD(SQLOCK(outer))); 6207 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 6208 outer->sq_oprev != NULL); 6209 while ((mp = outer->sq_evhead) != NULL) { 6210 /* 6211 * queues cannot be placed on the queuelist on the outer 6212 * perimeter. 6213 */ 6214 ASSERT(!(outer->sq_flags & SQ_MESSAGES)); 6215 ASSERT((outer->sq_flags & SQ_EVENTS)); 6216 6217 outer->sq_evhead = mp->b_next; 6218 if (outer->sq_evhead == NULL) { 6219 outer->sq_evtail = NULL; 6220 outer->sq_flags &= ~SQ_EVENTS; 6221 } 6222 ASSERT(outer->sq_count != 0); 6223 outer->sq_count--; /* Incremented when enqueued. */ 6224 mutex_exit(SQLOCK(outer)); 6225 /* 6226 * Drop the message if the queue is closing. 6227 * Make sure that the queue is "claimed" when the callback 6228 * is run in order to satisfy various ASSERTs. 6229 */ 6230 q = mp->b_queue; 6231 func = (void (*)())mp->b_prev; 6232 ASSERT(func != NULL); 6233 mp->b_next = mp->b_prev = NULL; 6234 if (q->q_flag & QWCLOSE) { 6235 freemsg(mp); 6236 } else { 6237 claimq(q); 6238 (*func)(q, mp); 6239 releaseq(q); 6240 } 6241 mutex_enter(SQLOCK(outer)); 6242 } 6243 ASSERT(MUTEX_HELD(SQLOCK(outer))); 6244 } 6245 6246 /* 6247 * The list of messages on the inner syncq is effectively hashed 6248 * by destination queue. These destination queues are doubly 6249 * linked lists (hopefully) in priority order. Messages are then 6250 * put on the queue referenced by the q_sqhead/q_sqtail elements. 6251 * Additional messages are linked together by the b_next/b_prev 6252 * elements in the mblk, with (similar to putq()) the first message 6253 * having a NULL b_prev and the last message having a NULL b_next. 6254 * 6255 * Events, such as qwriter callbacks, are put onto a list in FIFO 6256 * order referenced by sq_evhead, and sq_evtail. This is a singly 6257 * linked list, and messages here MUST be processed in the order queued. 6258 */ 6259 6260 /* 6261 * Run the events on the syncq event list (sq_evhead). 6262 * Assumes there is only one claim on the syncq, it is 6263 * already exclusive (SQ_EXCL set), and the SQLOCK held. 6264 * Messages here are processed in order, with the SQ_EXCL bit 6265 * held all the way through till the last message is processed. 6266 */ 6267 void 6268 sq_run_events(syncq_t *sq) 6269 { 6270 mblk_t *bp; 6271 queue_t *qp; 6272 uint16_t flags = sq->sq_flags; 6273 void (*func)(); 6274 6275 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6276 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6277 sq->sq_oprev == NULL) || 6278 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6279 sq->sq_oprev != NULL)); 6280 6281 ASSERT(flags & SQ_EXCL); 6282 ASSERT(sq->sq_count == 1); 6283 6284 /* 6285 * We need to process all of the events on this list. It 6286 * is possible that new events will be added while we are 6287 * away processing a callback, so on every loop, we start 6288 * back at the beginning of the list. 6289 */ 6290 /* 6291 * We have to reaccess sq_evhead since there is a 6292 * possibility of a new entry while we were running 6293 * the callback. 6294 */ 6295 for (bp = sq->sq_evhead; bp != NULL; bp = sq->sq_evhead) { 6296 ASSERT(bp->b_queue->q_syncq == sq); 6297 ASSERT(sq->sq_flags & SQ_EVENTS); 6298 6299 qp = bp->b_queue; 6300 func = (void (*)())bp->b_prev; 6301 ASSERT(func != NULL); 6302 6303 /* 6304 * Messages from the event queue must be taken off in 6305 * FIFO order. 6306 */ 6307 ASSERT(sq->sq_evhead == bp); 6308 sq->sq_evhead = bp->b_next; 6309 6310 if (bp->b_next == NULL) { 6311 /* Deleting last */ 6312 ASSERT(sq->sq_evtail == bp); 6313 sq->sq_evtail = NULL; 6314 sq->sq_flags &= ~SQ_EVENTS; 6315 } 6316 bp->b_prev = bp->b_next = NULL; 6317 ASSERT(bp->b_datap->db_ref != 0); 6318 6319 mutex_exit(SQLOCK(sq)); 6320 6321 (*func)(qp, bp); 6322 6323 mutex_enter(SQLOCK(sq)); 6324 /* 6325 * re-read the flags, since they could have changed. 6326 */ 6327 flags = sq->sq_flags; 6328 ASSERT(flags & SQ_EXCL); 6329 } 6330 ASSERT(sq->sq_evhead == NULL && sq->sq_evtail == NULL); 6331 ASSERT(!(sq->sq_flags & SQ_EVENTS)); 6332 6333 if (flags & SQ_WANTWAKEUP) { 6334 flags &= ~SQ_WANTWAKEUP; 6335 cv_broadcast(&sq->sq_wait); 6336 } 6337 if (flags & SQ_WANTEXWAKEUP) { 6338 flags &= ~SQ_WANTEXWAKEUP; 6339 cv_broadcast(&sq->sq_exitwait); 6340 } 6341 sq->sq_flags = flags; 6342 } 6343 6344 /* 6345 * Put messages on the event list. 6346 * If we can go exclusive now, do so and process the event list, otherwise 6347 * let the last claim service this list (or wake the sqthread). 6348 * This procedure assumes SQLOCK is held. To run the event list, it 6349 * must be called with no claims. 6350 */ 6351 static void 6352 sqfill_events(syncq_t *sq, queue_t *q, mblk_t *mp, void (*func)()) 6353 { 6354 uint16_t count; 6355 6356 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6357 ASSERT(func != NULL); 6358 6359 /* 6360 * This is a callback. Add it to the list of callbacks 6361 * and see about upgrading. 6362 */ 6363 mp->b_prev = (mblk_t *)func; 6364 mp->b_queue = q; 6365 mp->b_next = NULL; 6366 if (sq->sq_evhead == NULL) { 6367 sq->sq_evhead = sq->sq_evtail = mp; 6368 sq->sq_flags |= SQ_EVENTS; 6369 } else { 6370 ASSERT(sq->sq_evtail != NULL); 6371 ASSERT(sq->sq_evtail->b_next == NULL); 6372 ASSERT(sq->sq_flags & SQ_EVENTS); 6373 sq->sq_evtail->b_next = mp; 6374 sq->sq_evtail = mp; 6375 } 6376 /* 6377 * We have set SQ_EVENTS, so threads will have to 6378 * unwind out of the perimeter, and new entries will 6379 * not grab a putlock. But we still need to know 6380 * how many threads have already made a claim to the 6381 * syncq, so grab the putlocks, and sum the counts. 6382 * If there are no claims on the syncq, we can upgrade 6383 * to exclusive, and run the event list. 6384 * NOTE: We hold the SQLOCK, so we can just grab the 6385 * putlocks. 6386 */ 6387 count = sq->sq_count; 6388 SQ_PUTLOCKS_ENTER(sq); 6389 SUM_SQ_PUTCOUNTS(sq, count); 6390 /* 6391 * We have no claim, so we need to check if there 6392 * are no others, then we can upgrade. 6393 */ 6394 /* 6395 * There are currently no claims on 6396 * the syncq by this thread (at least on this entry). The thread who has 6397 * the claim should drain syncq. 6398 */ 6399 if (count > 0) { 6400 /* 6401 * Can't upgrade - other threads inside. 6402 */ 6403 SQ_PUTLOCKS_EXIT(sq); 6404 mutex_exit(SQLOCK(sq)); 6405 return; 6406 } 6407 /* 6408 * Need to set SQ_EXCL and make a claim on the syncq. 6409 */ 6410 ASSERT((sq->sq_flags & SQ_EXCL) == 0); 6411 sq->sq_flags |= SQ_EXCL; 6412 ASSERT(sq->sq_count == 0); 6413 sq->sq_count++; 6414 SQ_PUTLOCKS_EXIT(sq); 6415 6416 /* Process the events list */ 6417 sq_run_events(sq); 6418 6419 /* 6420 * Release our claim... 6421 */ 6422 sq->sq_count--; 6423 6424 /* 6425 * And release SQ_EXCL. 6426 * We don't need to acquire the putlocks to release 6427 * SQ_EXCL, since we are exclusive, and hold the SQLOCK. 6428 */ 6429 sq->sq_flags &= ~SQ_EXCL; 6430 6431 /* 6432 * sq_run_events should have released SQ_EXCL 6433 */ 6434 ASSERT(!(sq->sq_flags & SQ_EXCL)); 6435 6436 /* 6437 * If anything happened while we were running the 6438 * events (or was there before), we need to process 6439 * them now. We shouldn't be exclusive sine we 6440 * released the perimeter above (plus, we asserted 6441 * for it). 6442 */ 6443 if (!(sq->sq_flags & SQ_STAYAWAY) && (sq->sq_flags & SQ_QUEUED)) 6444 drain_syncq(sq); 6445 else 6446 mutex_exit(SQLOCK(sq)); 6447 } 6448 6449 /* 6450 * Perform delayed processing. The caller has to make sure that it is safe 6451 * to enter the syncq (e.g. by checking that none of the SQ_STAYAWAY bits are 6452 * set). 6453 * 6454 * Assume that the caller has NO claims on the syncq. However, a claim 6455 * on the syncq does not indicate that a thread is draining the syncq. 6456 * There may be more claims on the syncq than there are threads draining 6457 * (i.e. #_threads_draining <= sq_count) 6458 * 6459 * drain_syncq has to terminate when one of the SQ_STAYAWAY bits gets set 6460 * in order to preserve qwriter(OUTER) ordering constraints. 6461 * 6462 * sq_putcount only needs to be checked when dispatching the queued 6463 * writer call for CIPUT sync queue, but this is handled in sq_run_events. 6464 */ 6465 void 6466 drain_syncq(syncq_t *sq) 6467 { 6468 queue_t *qp; 6469 uint16_t count; 6470 uint16_t type = sq->sq_type; 6471 uint16_t flags = sq->sq_flags; 6472 boolean_t bg_service = sq->sq_svcflags & SQ_SERVICE; 6473 6474 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, 6475 "drain_syncq start:%p", sq); 6476 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6477 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6478 sq->sq_oprev == NULL) || 6479 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6480 sq->sq_oprev != NULL)); 6481 6482 /* 6483 * Drop SQ_SERVICE flag. 6484 */ 6485 if (bg_service) 6486 sq->sq_svcflags &= ~SQ_SERVICE; 6487 6488 /* 6489 * If SQ_EXCL is set, someone else is processing this syncq - let him 6490 * finish the job. 6491 */ 6492 if (flags & SQ_EXCL) { 6493 if (bg_service) { 6494 ASSERT(sq->sq_servcount != 0); 6495 sq->sq_servcount--; 6496 } 6497 mutex_exit(SQLOCK(sq)); 6498 return; 6499 } 6500 6501 /* 6502 * This routine can be called by a background thread if 6503 * it was scheduled by a hi-priority thread. SO, if there are 6504 * NOT messages queued, return (remember, we have the SQLOCK, 6505 * and it cannot change until we release it). Wakeup any waiters also. 6506 */ 6507 if (!(flags & SQ_QUEUED)) { 6508 if (flags & SQ_WANTWAKEUP) { 6509 flags &= ~SQ_WANTWAKEUP; 6510 cv_broadcast(&sq->sq_wait); 6511 } 6512 if (flags & SQ_WANTEXWAKEUP) { 6513 flags &= ~SQ_WANTEXWAKEUP; 6514 cv_broadcast(&sq->sq_exitwait); 6515 } 6516 sq->sq_flags = flags; 6517 if (bg_service) { 6518 ASSERT(sq->sq_servcount != 0); 6519 sq->sq_servcount--; 6520 } 6521 mutex_exit(SQLOCK(sq)); 6522 return; 6523 } 6524 6525 /* 6526 * If this is not a concurrent put perimeter, we need to 6527 * become exclusive to drain. Also, if not CIPUT, we would 6528 * not have acquired a putlock, so we don't need to check 6529 * the putcounts. If not entering with a claim, we test 6530 * for sq_count == 0. 6531 */ 6532 type = sq->sq_type; 6533 if (!(type & SQ_CIPUT)) { 6534 if (sq->sq_count > 1) { 6535 if (bg_service) { 6536 ASSERT(sq->sq_servcount != 0); 6537 sq->sq_servcount--; 6538 } 6539 mutex_exit(SQLOCK(sq)); 6540 return; 6541 } 6542 sq->sq_flags |= SQ_EXCL; 6543 } 6544 6545 /* 6546 * This is where we make a claim to the syncq. 6547 * This can either be done by incrementing a putlock, or 6548 * the sq_count. But since we already have the SQLOCK 6549 * here, we just bump the sq_count. 6550 * 6551 * Note that after we make a claim, we need to let the code 6552 * fall through to the end of this routine to clean itself 6553 * up. A return in the while loop will put the syncq in a 6554 * very bad state. 6555 */ 6556 sq->sq_count++; 6557 ASSERT(sq->sq_count != 0); /* wraparound */ 6558 6559 while ((flags = sq->sq_flags) & SQ_QUEUED) { 6560 /* 6561 * If we are told to stayaway or went exclusive, 6562 * we are done. 6563 */ 6564 if (flags & (SQ_STAYAWAY)) { 6565 break; 6566 } 6567 6568 /* 6569 * If there are events to run, do so. 6570 * We have one claim to the syncq, so if there are 6571 * more than one, other threads are running. 6572 */ 6573 if (sq->sq_evhead != NULL) { 6574 ASSERT(sq->sq_flags & SQ_EVENTS); 6575 6576 count = sq->sq_count; 6577 SQ_PUTLOCKS_ENTER(sq); 6578 SUM_SQ_PUTCOUNTS(sq, count); 6579 if (count > 1) { 6580 SQ_PUTLOCKS_EXIT(sq); 6581 /* Can't upgrade - other threads inside */ 6582 break; 6583 } 6584 ASSERT((flags & SQ_EXCL) == 0); 6585 sq->sq_flags = flags | SQ_EXCL; 6586 SQ_PUTLOCKS_EXIT(sq); 6587 /* 6588 * we have the only claim, run the events, 6589 * sq_run_events will clear the SQ_EXCL flag. 6590 */ 6591 sq_run_events(sq); 6592 6593 /* 6594 * If this is a CIPUT perimeter, we need 6595 * to drop the SQ_EXCL flag so we can properly 6596 * continue draining the syncq. 6597 */ 6598 if (type & SQ_CIPUT) { 6599 ASSERT(sq->sq_flags & SQ_EXCL); 6600 sq->sq_flags &= ~SQ_EXCL; 6601 } 6602 6603 /* 6604 * And go back to the beginning just in case 6605 * anything changed while we were away. 6606 */ 6607 ASSERT((sq->sq_flags & SQ_EXCL) || (type & SQ_CIPUT)); 6608 continue; 6609 } 6610 6611 ASSERT(sq->sq_evhead == NULL); 6612 ASSERT(!(sq->sq_flags & SQ_EVENTS)); 6613 6614 /* 6615 * Find the queue that is not draining. 6616 * 6617 * q_draining is protected by QLOCK which we do not hold. 6618 * But if it was set, then a thread was draining, and if it gets 6619 * cleared, then it was because the thread has successfully 6620 * drained the syncq, or a GOAWAY state occurred. For the GOAWAY 6621 * state to happen, a thread needs the SQLOCK which we hold, and 6622 * if there was such a flag, we would have already seen it. 6623 */ 6624 6625 for (qp = sq->sq_head; 6626 qp != NULL && (qp->q_draining || 6627 (qp->q_sqflags & Q_SQDRAINING)); 6628 qp = qp->q_sqnext) 6629 ; 6630 6631 if (qp == NULL) 6632 break; 6633 6634 /* 6635 * We have a queue to work on, and we hold the 6636 * SQLOCK and one claim, call qdrain_syncq. 6637 * This means we need to release the SQLOCK and 6638 * acquire the QLOCK (OK since we have a claim). 6639 * Note that qdrain_syncq will actually dequeue 6640 * this queue from the sq_head list when it is 6641 * convinced all the work is done and release 6642 * the QLOCK before returning. 6643 */ 6644 qp->q_sqflags |= Q_SQDRAINING; 6645 mutex_exit(SQLOCK(sq)); 6646 mutex_enter(QLOCK(qp)); 6647 qdrain_syncq(sq, qp); 6648 mutex_enter(SQLOCK(sq)); 6649 6650 /* The queue is drained */ 6651 ASSERT(qp->q_sqflags & Q_SQDRAINING); 6652 qp->q_sqflags &= ~Q_SQDRAINING; 6653 /* 6654 * NOTE: After this point qp should not be used since it may be 6655 * closed. 6656 */ 6657 } 6658 6659 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6660 flags = sq->sq_flags; 6661 6662 /* 6663 * sq->sq_head cannot change because we hold the 6664 * sqlock. However, a thread CAN decide that it is no longer 6665 * going to drain that queue. However, this should be due to 6666 * a GOAWAY state, and we should see that here. 6667 * 6668 * This loop is not very efficient. One solution may be adding a second 6669 * pointer to the "draining" queue, but it is difficult to do when 6670 * queues are inserted in the middle due to priority ordering. Another 6671 * possibility is to yank the queue out of the sq list and put it onto 6672 * the "draining list" and then put it back if it can't be drained. 6673 */ 6674 6675 ASSERT((sq->sq_head == NULL) || (flags & SQ_GOAWAY) || 6676 (type & SQ_CI) || sq->sq_head->q_draining); 6677 6678 /* Drop SQ_EXCL for non-CIPUT perimeters */ 6679 if (!(type & SQ_CIPUT)) 6680 flags &= ~SQ_EXCL; 6681 ASSERT((flags & SQ_EXCL) == 0); 6682 6683 /* Wake up any waiters. */ 6684 if (flags & SQ_WANTWAKEUP) { 6685 flags &= ~SQ_WANTWAKEUP; 6686 cv_broadcast(&sq->sq_wait); 6687 } 6688 if (flags & SQ_WANTEXWAKEUP) { 6689 flags &= ~SQ_WANTEXWAKEUP; 6690 cv_broadcast(&sq->sq_exitwait); 6691 } 6692 sq->sq_flags = flags; 6693 6694 ASSERT(sq->sq_count != 0); 6695 /* Release our claim. */ 6696 sq->sq_count--; 6697 6698 if (bg_service) { 6699 ASSERT(sq->sq_servcount != 0); 6700 sq->sq_servcount--; 6701 } 6702 6703 mutex_exit(SQLOCK(sq)); 6704 6705 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, 6706 "drain_syncq end:%p", sq); 6707 } 6708 6709 6710 /* 6711 * 6712 * qdrain_syncq can be called (currently) from only one of two places: 6713 * drain_syncq 6714 * putnext (or some variation of it). 6715 * and eventually 6716 * qwait(_sig) 6717 * 6718 * If called from drain_syncq, we found it in the list of queues needing 6719 * service, so there is work to be done (or it wouldn't be in the list). 6720 * 6721 * If called from some putnext variation, it was because the 6722 * perimeter is open, but messages are blocking a putnext and 6723 * there is not a thread working on it. Now a thread could start 6724 * working on it while we are getting ready to do so ourself, but 6725 * the thread would set the q_draining flag, and we can spin out. 6726 * 6727 * As for qwait(_sig), I think I shall let it continue to call 6728 * drain_syncq directly (after all, it will get here eventually). 6729 * 6730 * qdrain_syncq has to terminate when: 6731 * - one of the SQ_STAYAWAY bits gets set to preserve qwriter(OUTER) ordering 6732 * - SQ_EVENTS gets set to preserve qwriter(INNER) ordering 6733 * 6734 * ASSUMES: 6735 * One claim 6736 * QLOCK held 6737 * SQLOCK not held 6738 * Will release QLOCK before returning 6739 */ 6740 void 6741 qdrain_syncq(syncq_t *sq, queue_t *q) 6742 { 6743 mblk_t *bp; 6744 #ifdef DEBUG 6745 uint16_t count; 6746 #endif 6747 6748 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, 6749 "drain_syncq start:%p", sq); 6750 ASSERT(q->q_syncq == sq); 6751 ASSERT(MUTEX_HELD(QLOCK(q))); 6752 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6753 /* 6754 * For non-CIPUT perimeters, we should be called with the exclusive bit 6755 * set already. For CIPUT perimeters, we will be doing a concurrent 6756 * drain, so it better not be set. 6757 */ 6758 ASSERT((sq->sq_flags & (SQ_EXCL|SQ_CIPUT))); 6759 ASSERT(!((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL))); 6760 ASSERT((sq->sq_type & SQ_CIPUT) || (sq->sq_flags & SQ_EXCL)); 6761 /* 6762 * All outer pointers are set, or none of them are 6763 */ 6764 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6765 sq->sq_oprev == NULL) || 6766 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6767 sq->sq_oprev != NULL)); 6768 #ifdef DEBUG 6769 count = sq->sq_count; 6770 /* 6771 * This is OK without the putlocks, because we have one 6772 * claim either from the sq_count, or a putcount. We could 6773 * get an erroneous value from other counts, but ours won't 6774 * change, so one way or another, we will have at least a 6775 * value of one. 6776 */ 6777 SUM_SQ_PUTCOUNTS(sq, count); 6778 ASSERT(count >= 1); 6779 #endif /* DEBUG */ 6780 6781 /* 6782 * The first thing to do is find out if a thread is already draining 6783 * this queue. If so, we are done, just return. 6784 */ 6785 if (q->q_draining) { 6786 mutex_exit(QLOCK(q)); 6787 return; 6788 } 6789 6790 /* 6791 * If the perimeter is exclusive, there is nothing we can do right now, 6792 * go away. Note that there is nothing to prevent this case from 6793 * changing right after this check, but the spin-out will catch it. 6794 */ 6795 6796 /* Tell other threads that we are draining this queue */ 6797 q->q_draining = 1; /* Protected by QLOCK */ 6798 6799 /* 6800 * If there is nothing to do, clear QFULL as necessary. This caters for 6801 * the case where an empty queue was enqueued onto the syncq. 6802 */ 6803 if (q->q_sqhead == NULL) { 6804 ASSERT(q->q_syncqmsgs == 0); 6805 mutex_exit(QLOCK(q)); 6806 clr_qfull(q); 6807 mutex_enter(QLOCK(q)); 6808 } 6809 6810 /* 6811 * Note that q_sqhead must be re-checked here in case another message 6812 * was enqueued whilst QLOCK was dropped during the call to clr_qfull. 6813 */ 6814 for (bp = q->q_sqhead; bp != NULL; bp = q->q_sqhead) { 6815 /* 6816 * Because we can enter this routine just because a putnext is 6817 * blocked, we need to spin out if the perimeter wants to go 6818 * exclusive as well as just blocked. We need to spin out also 6819 * if events are queued on the syncq. 6820 * Don't check for SQ_EXCL, because non-CIPUT perimeters would 6821 * set it, and it can't become exclusive while we hold a claim. 6822 */ 6823 if (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS)) { 6824 break; 6825 } 6826 6827 #ifdef DEBUG 6828 /* 6829 * Since we are in qdrain_syncq, we already know the queue, 6830 * but for sanity, we want to check this against the qp that 6831 * was passed in by bp->b_queue. 6832 */ 6833 6834 ASSERT(bp->b_queue == q); 6835 ASSERT(bp->b_queue->q_syncq == sq); 6836 bp->b_queue = NULL; 6837 6838 /* 6839 * We would have the following check in the DEBUG code: 6840 * 6841 * if (bp->b_prev != NULL) { 6842 * ASSERT(bp->b_prev == (void (*)())q->q_qinfo->qi_putp); 6843 * } 6844 * 6845 * This can't be done, however, since IP modifies qinfo 6846 * structure at run-time (switching between IPv4 qinfo and IPv6 6847 * qinfo), invalidating the check. 6848 * So the assignment to func is left here, but the ASSERT itself 6849 * is removed until the whole issue is resolved. 6850 */ 6851 #endif 6852 ASSERT(q->q_sqhead == bp); 6853 q->q_sqhead = bp->b_next; 6854 bp->b_prev = bp->b_next = NULL; 6855 ASSERT(q->q_syncqmsgs > 0); 6856 mutex_exit(QLOCK(q)); 6857 6858 ASSERT(bp->b_datap->db_ref != 0); 6859 6860 (void) (*q->q_qinfo->qi_putp)(q, bp); 6861 6862 mutex_enter(QLOCK(q)); 6863 6864 /* 6865 * q_syncqmsgs should only be decremented after executing the 6866 * put procedure to avoid message re-ordering. This is due to an 6867 * optimisation in putnext() which can call the put procedure 6868 * directly if it sees q_syncqmsgs == 0 (despite Q_SQQUEUED 6869 * being set). 6870 * 6871 * We also need to clear QFULL in the next service procedure 6872 * queue if this is the last message destined for that queue. 6873 * 6874 * It would make better sense to have some sort of tunable for 6875 * the low water mark, but these semantics are not yet defined. 6876 * So, alas, we use a constant. 6877 */ 6878 if (--q->q_syncqmsgs == 0) { 6879 mutex_exit(QLOCK(q)); 6880 clr_qfull(q); 6881 mutex_enter(QLOCK(q)); 6882 } 6883 6884 /* 6885 * Always clear SQ_EXCL when CIPUT in order to handle 6886 * qwriter(INNER). The putp() can call qwriter and get exclusive 6887 * access IFF this is the only claim. So, we need to test for 6888 * this possibility, acquire the mutex and clear the bit. 6889 */ 6890 if ((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL)) { 6891 mutex_enter(SQLOCK(sq)); 6892 sq->sq_flags &= ~SQ_EXCL; 6893 mutex_exit(SQLOCK(sq)); 6894 } 6895 } 6896 6897 /* 6898 * We should either have no messages on this queue, or we were told to 6899 * goaway by a waiter (which we will wake up at the end of this 6900 * function). 6901 */ 6902 ASSERT((q->q_sqhead == NULL) || 6903 (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS))); 6904 6905 ASSERT(MUTEX_HELD(QLOCK(q))); 6906 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6907 6908 /* Remove the q from the syncq list if all the messages are drained. */ 6909 if (q->q_sqhead == NULL) { 6910 ASSERT(q->q_syncqmsgs == 0); 6911 mutex_enter(SQLOCK(sq)); 6912 if (q->q_sqflags & Q_SQQUEUED) 6913 SQRM_Q(sq, q); 6914 mutex_exit(SQLOCK(sq)); 6915 /* 6916 * Since the queue is removed from the list, reset its priority. 6917 */ 6918 q->q_spri = 0; 6919 } 6920 6921 /* 6922 * Remember, the q_draining flag is used to let another thread know 6923 * that there is a thread currently draining the messages for a queue. 6924 * Since we are now done with this queue (even if there may be messages 6925 * still there), we need to clear this flag so some thread will work on 6926 * it if needed. 6927 */ 6928 ASSERT(q->q_draining); 6929 q->q_draining = 0; 6930 6931 /* Called with a claim, so OK to drop all locks. */ 6932 mutex_exit(QLOCK(q)); 6933 6934 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, 6935 "drain_syncq end:%p", sq); 6936 } 6937 /* END OF QDRAIN_SYNCQ */ 6938 6939 6940 /* 6941 * This is the mate to qdrain_syncq, except that it is putting the message onto 6942 * the queue instead of draining. Since the message is destined for the queue 6943 * that is selected, there is no need to identify the function because the 6944 * message is intended for the put routine for the queue. For debug kernels, 6945 * this routine will do it anyway just in case. 6946 * 6947 * After the message is enqueued on the syncq, it calls putnext_tail() 6948 * which will schedule a background thread to actually process the message. 6949 * 6950 * Assumes that there is a claim on the syncq (sq->sq_count > 0) and 6951 * SQLOCK(sq) and QLOCK(q) are not held. 6952 */ 6953 void 6954 qfill_syncq(syncq_t *sq, queue_t *q, mblk_t *mp) 6955 { 6956 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6957 ASSERT(MUTEX_NOT_HELD(QLOCK(q))); 6958 ASSERT(sq->sq_count > 0); 6959 ASSERT(q->q_syncq == sq); 6960 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6961 sq->sq_oprev == NULL) || 6962 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6963 sq->sq_oprev != NULL)); 6964 6965 mutex_enter(QLOCK(q)); 6966 6967 #ifdef DEBUG 6968 /* 6969 * This is used for debug in the qfill_syncq/qdrain_syncq case 6970 * to trace the queue that the message is intended for. Note 6971 * that the original use was to identify the queue and function 6972 * to call on the drain. In the new syncq, we have the context 6973 * of the queue that we are draining, so call it's putproc and 6974 * don't rely on the saved values. But for debug this is still 6975 * useful information. 6976 */ 6977 mp->b_prev = (mblk_t *)q->q_qinfo->qi_putp; 6978 mp->b_queue = q; 6979 mp->b_next = NULL; 6980 #endif 6981 ASSERT(q->q_syncq == sq); 6982 /* 6983 * Enqueue the message on the list. 6984 * SQPUT_MP() accesses q_syncqmsgs. We are already holding QLOCK to 6985 * protect it. So it's ok to acquire SQLOCK after SQPUT_MP(). 6986 */ 6987 SQPUT_MP(q, mp); 6988 mutex_enter(SQLOCK(sq)); 6989 6990 /* 6991 * And queue on syncq for scheduling, if not already queued. 6992 * Note that we need the SQLOCK for this, and for testing flags 6993 * at the end to see if we will drain. So grab it now, and 6994 * release it before we call qdrain_syncq or return. 6995 */ 6996 if (!(q->q_sqflags & Q_SQQUEUED)) { 6997 q->q_spri = curthread->t_pri; 6998 SQPUT_Q(sq, q); 6999 } 7000 #ifdef DEBUG 7001 else { 7002 /* 7003 * All of these conditions MUST be true! 7004 */ 7005 ASSERT(sq->sq_tail != NULL); 7006 if (sq->sq_tail == sq->sq_head) { 7007 ASSERT((q->q_sqprev == NULL) && 7008 (q->q_sqnext == NULL)); 7009 } else { 7010 ASSERT((q->q_sqprev != NULL) || 7011 (q->q_sqnext != NULL)); 7012 } 7013 ASSERT(sq->sq_flags & SQ_QUEUED); 7014 ASSERT(q->q_syncqmsgs != 0); 7015 ASSERT(q->q_sqflags & Q_SQQUEUED); 7016 } 7017 #endif 7018 mutex_exit(QLOCK(q)); 7019 /* 7020 * SQLOCK is still held, so sq_count can be safely decremented. 7021 */ 7022 sq->sq_count--; 7023 7024 putnext_tail(sq, q, 0); 7025 /* Should not reference sq or q after this point. */ 7026 } 7027 7028 /* End of qfill_syncq */ 7029 7030 /* 7031 * Remove all messages from a syncq (if qp is NULL) or remove all messages 7032 * that would be put into qp by drain_syncq. 7033 * Used when deleting the syncq (qp == NULL) or when detaching 7034 * a queue (qp != NULL). 7035 * Return non-zero if one or more messages were freed. 7036 * 7037 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 7038 * sq_putlocks are used. 7039 * 7040 * NOTE: This function assumes that it is called from the close() context and 7041 * that all the queues in the syncq are going away. For this reason it doesn't 7042 * acquire QLOCK for modifying q_sqhead/q_sqtail fields. This assumption is 7043 * currently valid, but it is useful to rethink this function to behave properly 7044 * in other cases. 7045 */ 7046 int 7047 flush_syncq(syncq_t *sq, queue_t *qp) 7048 { 7049 mblk_t *bp, *mp_head, *mp_next, *mp_prev; 7050 queue_t *q; 7051 int ret = 0; 7052 7053 mutex_enter(SQLOCK(sq)); 7054 7055 /* 7056 * Before we leave, we need to make sure there are no 7057 * events listed for this queue. All events for this queue 7058 * will just be freed. 7059 */ 7060 if (qp != NULL && sq->sq_evhead != NULL) { 7061 ASSERT(sq->sq_flags & SQ_EVENTS); 7062 7063 mp_prev = NULL; 7064 for (bp = sq->sq_evhead; bp != NULL; bp = mp_next) { 7065 mp_next = bp->b_next; 7066 if (bp->b_queue == qp) { 7067 /* Delete this message */ 7068 if (mp_prev != NULL) { 7069 mp_prev->b_next = mp_next; 7070 /* 7071 * Update sq_evtail if the last element 7072 * is removed. 7073 */ 7074 if (bp == sq->sq_evtail) { 7075 ASSERT(mp_next == NULL); 7076 sq->sq_evtail = mp_prev; 7077 } 7078 } else 7079 sq->sq_evhead = mp_next; 7080 if (sq->sq_evhead == NULL) 7081 sq->sq_flags &= ~SQ_EVENTS; 7082 bp->b_prev = bp->b_next = NULL; 7083 freemsg(bp); 7084 ret++; 7085 } else { 7086 mp_prev = bp; 7087 } 7088 } 7089 } 7090 7091 /* 7092 * Walk sq_head and: 7093 * - match qp if qp is set, remove it's messages 7094 * - all if qp is not set 7095 */ 7096 q = sq->sq_head; 7097 while (q != NULL) { 7098 ASSERT(q->q_syncq == sq); 7099 if ((qp == NULL) || (qp == q)) { 7100 /* 7101 * Yank the messages as a list off the queue 7102 */ 7103 mp_head = q->q_sqhead; 7104 /* 7105 * We do not have QLOCK(q) here (which is safe due to 7106 * assumptions mentioned above). To obtain the lock we 7107 * need to release SQLOCK which may allow lots of things 7108 * to change upon us. This place requires more analysis. 7109 */ 7110 q->q_sqhead = q->q_sqtail = NULL; 7111 ASSERT(mp_head->b_queue && 7112 mp_head->b_queue->q_syncq == sq); 7113 7114 /* 7115 * Free each of the messages. 7116 */ 7117 for (bp = mp_head; bp != NULL; bp = mp_next) { 7118 mp_next = bp->b_next; 7119 bp->b_prev = bp->b_next = NULL; 7120 freemsg(bp); 7121 ret++; 7122 } 7123 /* 7124 * Now remove the queue from the syncq. 7125 */ 7126 ASSERT(q->q_sqflags & Q_SQQUEUED); 7127 SQRM_Q(sq, q); 7128 q->q_spri = 0; 7129 q->q_syncqmsgs = 0; 7130 7131 /* 7132 * If qp was specified, we are done with it and are 7133 * going to drop SQLOCK(sq) and return. We wakeup syncq 7134 * waiters while we still have the SQLOCK. 7135 */ 7136 if ((qp != NULL) && (sq->sq_flags & SQ_WANTWAKEUP)) { 7137 sq->sq_flags &= ~SQ_WANTWAKEUP; 7138 cv_broadcast(&sq->sq_wait); 7139 } 7140 /* Drop SQLOCK across clr_qfull */ 7141 mutex_exit(SQLOCK(sq)); 7142 7143 /* 7144 * We avoid doing the test that drain_syncq does and 7145 * unconditionally clear qfull for every flushed 7146 * message. Since flush_syncq is only called during 7147 * close this should not be a problem. 7148 */ 7149 clr_qfull(q); 7150 if (qp != NULL) { 7151 return (ret); 7152 } else { 7153 mutex_enter(SQLOCK(sq)); 7154 /* 7155 * The head was removed by SQRM_Q above. 7156 * reread the new head and flush it. 7157 */ 7158 q = sq->sq_head; 7159 } 7160 } else { 7161 q = q->q_sqnext; 7162 } 7163 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7164 } 7165 7166 if (sq->sq_flags & SQ_WANTWAKEUP) { 7167 sq->sq_flags &= ~SQ_WANTWAKEUP; 7168 cv_broadcast(&sq->sq_wait); 7169 } 7170 7171 mutex_exit(SQLOCK(sq)); 7172 return (ret); 7173 } 7174 7175 /* 7176 * Propagate all messages from a syncq to the next syncq that are associated 7177 * with the specified queue. If the queue is attached to a driver or if the 7178 * messages have been added due to a qwriter(PERIM_INNER), free the messages. 7179 * 7180 * Assumes that the stream is strlock()'ed. We don't come here if there 7181 * are no messages to propagate. 7182 * 7183 * NOTE : If the queue is attached to a driver, all the messages are freed 7184 * as there is no point in propagating the messages from the driver syncq 7185 * to the closing stream head which will in turn get freed later. 7186 */ 7187 static int 7188 propagate_syncq(queue_t *qp) 7189 { 7190 mblk_t *bp, *head, *tail, *prev, *next; 7191 syncq_t *sq; 7192 queue_t *nqp; 7193 syncq_t *nsq; 7194 boolean_t isdriver; 7195 int moved = 0; 7196 uint16_t flags; 7197 pri_t priority = curthread->t_pri; 7198 #ifdef DEBUG 7199 void (*func)(); 7200 #endif 7201 7202 sq = qp->q_syncq; 7203 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7204 /* debug macro */ 7205 SQ_PUTLOCKS_HELD(sq); 7206 /* 7207 * As entersq() does not increment the sq_count for 7208 * the write side, check sq_count for non-QPERQ 7209 * perimeters alone. 7210 */ 7211 ASSERT((qp->q_flag & QPERQ) || (sq->sq_count >= 1)); 7212 7213 /* 7214 * propagate_syncq() can be called because of either messages on the 7215 * queue syncq or because on events on the queue syncq. Do actual 7216 * message propagations if there are any messages. 7217 */ 7218 if (qp->q_syncqmsgs) { 7219 isdriver = (qp->q_flag & QISDRV); 7220 7221 if (!isdriver) { 7222 nqp = qp->q_next; 7223 nsq = nqp->q_syncq; 7224 ASSERT(MUTEX_HELD(SQLOCK(nsq))); 7225 /* debug macro */ 7226 SQ_PUTLOCKS_HELD(nsq); 7227 #ifdef DEBUG 7228 func = (void (*)())nqp->q_qinfo->qi_putp; 7229 #endif 7230 } 7231 7232 SQRM_Q(sq, qp); 7233 priority = MAX(qp->q_spri, priority); 7234 qp->q_spri = 0; 7235 head = qp->q_sqhead; 7236 tail = qp->q_sqtail; 7237 qp->q_sqhead = qp->q_sqtail = NULL; 7238 qp->q_syncqmsgs = 0; 7239 7240 /* 7241 * Walk the list of messages, and free them if this is a driver, 7242 * otherwise reset the b_prev and b_queue value to the new putp. 7243 * Afterward, we will just add the head to the end of the next 7244 * syncq, and point the tail to the end of this one. 7245 */ 7246 7247 for (bp = head; bp != NULL; bp = next) { 7248 next = bp->b_next; 7249 if (isdriver) { 7250 bp->b_prev = bp->b_next = NULL; 7251 freemsg(bp); 7252 continue; 7253 } 7254 /* Change the q values for this message */ 7255 bp->b_queue = nqp; 7256 #ifdef DEBUG 7257 bp->b_prev = (mblk_t *)func; 7258 #endif 7259 moved++; 7260 } 7261 /* 7262 * Attach list of messages to the end of the new queue (if there 7263 * is a list of messages). 7264 */ 7265 7266 if (!isdriver && head != NULL) { 7267 ASSERT(tail != NULL); 7268 if (nqp->q_sqhead == NULL) { 7269 nqp->q_sqhead = head; 7270 } else { 7271 ASSERT(nqp->q_sqtail != NULL); 7272 nqp->q_sqtail->b_next = head; 7273 } 7274 nqp->q_sqtail = tail; 7275 /* 7276 * When messages are moved from high priority queue to 7277 * another queue, the destination queue priority is 7278 * upgraded. 7279 */ 7280 7281 if (priority > nqp->q_spri) 7282 nqp->q_spri = priority; 7283 7284 SQPUT_Q(nsq, nqp); 7285 7286 nqp->q_syncqmsgs += moved; 7287 ASSERT(nqp->q_syncqmsgs != 0); 7288 } 7289 } 7290 7291 /* 7292 * Before we leave, we need to make sure there are no 7293 * events listed for this queue. All events for this queue 7294 * will just be freed. 7295 */ 7296 if (sq->sq_evhead != NULL) { 7297 ASSERT(sq->sq_flags & SQ_EVENTS); 7298 prev = NULL; 7299 for (bp = sq->sq_evhead; bp != NULL; bp = next) { 7300 next = bp->b_next; 7301 if (bp->b_queue == qp) { 7302 /* Delete this message */ 7303 if (prev != NULL) { 7304 prev->b_next = next; 7305 /* 7306 * Update sq_evtail if the last element 7307 * is removed. 7308 */ 7309 if (bp == sq->sq_evtail) { 7310 ASSERT(next == NULL); 7311 sq->sq_evtail = prev; 7312 } 7313 } else 7314 sq->sq_evhead = next; 7315 if (sq->sq_evhead == NULL) 7316 sq->sq_flags &= ~SQ_EVENTS; 7317 bp->b_prev = bp->b_next = NULL; 7318 freemsg(bp); 7319 } else { 7320 prev = bp; 7321 } 7322 } 7323 } 7324 7325 flags = sq->sq_flags; 7326 7327 /* Wake up any waiter before leaving. */ 7328 if (flags & SQ_WANTWAKEUP) { 7329 flags &= ~SQ_WANTWAKEUP; 7330 cv_broadcast(&sq->sq_wait); 7331 } 7332 sq->sq_flags = flags; 7333 7334 return (moved); 7335 } 7336 7337 /* 7338 * Try and upgrade to exclusive access at the inner perimeter. If this can 7339 * not be done without blocking then request will be queued on the syncq 7340 * and drain_syncq will run it later. 7341 * 7342 * This routine can only be called from put or service procedures plus 7343 * asynchronous callback routines that have properly entered the queue (with 7344 * entersq). Thus qwriter_inner assumes the caller has one claim on the syncq 7345 * associated with q. 7346 */ 7347 void 7348 qwriter_inner(queue_t *q, mblk_t *mp, void (*func)()) 7349 { 7350 syncq_t *sq = q->q_syncq; 7351 uint16_t count; 7352 7353 mutex_enter(SQLOCK(sq)); 7354 count = sq->sq_count; 7355 SQ_PUTLOCKS_ENTER(sq); 7356 SUM_SQ_PUTCOUNTS(sq, count); 7357 ASSERT(count >= 1); 7358 ASSERT(sq->sq_type & (SQ_CIPUT|SQ_CISVC)); 7359 7360 if (count == 1) { 7361 /* 7362 * Can upgrade. This case also handles nested qwriter calls 7363 * (when the qwriter callback function calls qwriter). In that 7364 * case SQ_EXCL is already set. 7365 */ 7366 sq->sq_flags |= SQ_EXCL; 7367 SQ_PUTLOCKS_EXIT(sq); 7368 mutex_exit(SQLOCK(sq)); 7369 (*func)(q, mp); 7370 /* 7371 * Assumes that leavesq, putnext, and drain_syncq will reset 7372 * SQ_EXCL for SQ_CIPUT/SQ_CISVC queues. We leave SQ_EXCL on 7373 * until putnext, leavesq, or drain_syncq drops it. 7374 * That way we handle nested qwriter(INNER) without dropping 7375 * SQ_EXCL until the outermost qwriter callback routine is 7376 * done. 7377 */ 7378 return; 7379 } 7380 SQ_PUTLOCKS_EXIT(sq); 7381 sqfill_events(sq, q, mp, func); 7382 } 7383 7384 /* 7385 * Synchronous callback support functions 7386 */ 7387 7388 /* 7389 * Allocate a callback parameter structure. 7390 * Assumes that caller initializes the flags and the id. 7391 * Acquires SQLOCK(sq) if non-NULL is returned. 7392 */ 7393 callbparams_t * 7394 callbparams_alloc(syncq_t *sq, void (*func)(void *), void *arg, int kmflags) 7395 { 7396 callbparams_t *cbp; 7397 size_t size = sizeof (callbparams_t); 7398 7399 cbp = kmem_alloc(size, kmflags & ~KM_PANIC); 7400 7401 /* 7402 * Only try tryhard allocation if the caller is ready to panic. 7403 * Otherwise just fail. 7404 */ 7405 if (cbp == NULL) { 7406 if (kmflags & KM_PANIC) 7407 cbp = kmem_alloc_tryhard(sizeof (callbparams_t), 7408 &size, kmflags); 7409 else 7410 return (NULL); 7411 } 7412 7413 ASSERT(size >= sizeof (callbparams_t)); 7414 cbp->cbp_size = size; 7415 cbp->cbp_sq = sq; 7416 cbp->cbp_func = func; 7417 cbp->cbp_arg = arg; 7418 mutex_enter(SQLOCK(sq)); 7419 cbp->cbp_next = sq->sq_callbpend; 7420 sq->sq_callbpend = cbp; 7421 return (cbp); 7422 } 7423 7424 void 7425 callbparams_free(syncq_t *sq, callbparams_t *cbp) 7426 { 7427 callbparams_t **pp, *p; 7428 7429 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7430 7431 for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { 7432 if (p == cbp) { 7433 *pp = p->cbp_next; 7434 kmem_free(p, p->cbp_size); 7435 return; 7436 } 7437 } 7438 (void) (STRLOG(0, 0, 0, SL_CONSOLE, 7439 "callbparams_free: not found\n")); 7440 } 7441 7442 void 7443 callbparams_free_id(syncq_t *sq, callbparams_id_t id, int32_t flag) 7444 { 7445 callbparams_t **pp, *p; 7446 7447 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7448 7449 for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { 7450 if (p->cbp_id == id && p->cbp_flags == flag) { 7451 *pp = p->cbp_next; 7452 kmem_free(p, p->cbp_size); 7453 return; 7454 } 7455 } 7456 (void) (STRLOG(0, 0, 0, SL_CONSOLE, 7457 "callbparams_free_id: not found\n")); 7458 } 7459 7460 /* 7461 * Callback wrapper function used by once-only callbacks that can be 7462 * cancelled (qtimeout and qbufcall) 7463 * Contains inline version of entersq(sq, SQ_CALLBACK) that can be 7464 * cancelled by the qun* functions. 7465 */ 7466 void 7467 qcallbwrapper(void *arg) 7468 { 7469 callbparams_t *cbp = arg; 7470 syncq_t *sq; 7471 uint16_t count = 0; 7472 uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; 7473 uint16_t type; 7474 7475 sq = cbp->cbp_sq; 7476 mutex_enter(SQLOCK(sq)); 7477 type = sq->sq_type; 7478 if (!(type & SQ_CICB)) { 7479 count = sq->sq_count; 7480 SQ_PUTLOCKS_ENTER(sq); 7481 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 7482 SUM_SQ_PUTCOUNTS(sq, count); 7483 sq->sq_needexcl++; 7484 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 7485 waitflags |= SQ_MESSAGES; 7486 } 7487 /* Can not handle exclusive entry at outer perimeter */ 7488 ASSERT(type & SQ_COCB); 7489 7490 while ((sq->sq_flags & waitflags) || (!(type & SQ_CICB) &&count != 0)) { 7491 if ((sq->sq_callbflags & cbp->cbp_flags) && 7492 (sq->sq_cancelid == cbp->cbp_id)) { 7493 /* timeout has been cancelled */ 7494 sq->sq_callbflags |= SQ_CALLB_BYPASSED; 7495 callbparams_free(sq, cbp); 7496 if (!(type & SQ_CICB)) { 7497 ASSERT(sq->sq_needexcl > 0); 7498 sq->sq_needexcl--; 7499 if (sq->sq_needexcl == 0) { 7500 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 7501 } 7502 SQ_PUTLOCKS_EXIT(sq); 7503 } 7504 mutex_exit(SQLOCK(sq)); 7505 return; 7506 } 7507 sq->sq_flags |= SQ_WANTWAKEUP; 7508 if (!(type & SQ_CICB)) { 7509 SQ_PUTLOCKS_EXIT(sq); 7510 } 7511 cv_wait(&sq->sq_wait, SQLOCK(sq)); 7512 if (!(type & SQ_CICB)) { 7513 count = sq->sq_count; 7514 SQ_PUTLOCKS_ENTER(sq); 7515 SUM_SQ_PUTCOUNTS(sq, count); 7516 } 7517 } 7518 7519 sq->sq_count++; 7520 ASSERT(sq->sq_count != 0); /* Wraparound */ 7521 if (!(type & SQ_CICB)) { 7522 ASSERT(count == 0); 7523 sq->sq_flags |= SQ_EXCL; 7524 ASSERT(sq->sq_needexcl > 0); 7525 sq->sq_needexcl--; 7526 if (sq->sq_needexcl == 0) { 7527 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 7528 } 7529 SQ_PUTLOCKS_EXIT(sq); 7530 } 7531 7532 mutex_exit(SQLOCK(sq)); 7533 7534 cbp->cbp_func(cbp->cbp_arg); 7535 7536 /* 7537 * We drop the lock only for leavesq to re-acquire it. 7538 * Possible optimization is inline of leavesq. 7539 */ 7540 mutex_enter(SQLOCK(sq)); 7541 callbparams_free(sq, cbp); 7542 mutex_exit(SQLOCK(sq)); 7543 leavesq(sq, SQ_CALLBACK); 7544 } 7545 7546 /* 7547 * No need to grab sq_putlocks here. See comment in strsubr.h that 7548 * explains when sq_putlocks are used. 7549 * 7550 * sq_count (or one of the sq_putcounts) has already been 7551 * decremented by the caller, and if SQ_QUEUED, we need to call 7552 * drain_syncq (the global syncq drain). 7553 * If putnext_tail is called with the SQ_EXCL bit set, we are in 7554 * one of two states, non-CIPUT perimeter, and we need to clear 7555 * it, or we went exclusive in the put procedure. In any case, 7556 * we want to clear the bit now, and it is probably easier to do 7557 * this at the beginning of this function (remember, we hold 7558 * the SQLOCK). Lastly, if there are other messages queued 7559 * on the syncq (and not for our destination), enable the syncq 7560 * for background work. 7561 */ 7562 7563 /* ARGSUSED */ 7564 void 7565 putnext_tail(syncq_t *sq, queue_t *qp, uint32_t passflags) 7566 { 7567 uint16_t flags = sq->sq_flags; 7568 7569 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7570 ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); 7571 7572 /* Clear SQ_EXCL if set in passflags */ 7573 if (passflags & SQ_EXCL) { 7574 flags &= ~SQ_EXCL; 7575 } 7576 if (flags & SQ_WANTWAKEUP) { 7577 flags &= ~SQ_WANTWAKEUP; 7578 cv_broadcast(&sq->sq_wait); 7579 } 7580 if (flags & SQ_WANTEXWAKEUP) { 7581 flags &= ~SQ_WANTEXWAKEUP; 7582 cv_broadcast(&sq->sq_exitwait); 7583 } 7584 sq->sq_flags = flags; 7585 7586 /* 7587 * We have cleared SQ_EXCL if we were asked to, and started 7588 * the wakeup process for waiters. If there are no writers 7589 * then we need to drain the syncq if we were told to, or 7590 * enable the background thread to do it. 7591 */ 7592 if (!(flags & (SQ_STAYAWAY|SQ_EXCL))) { 7593 if ((passflags & SQ_QUEUED) || 7594 (sq->sq_svcflags & SQ_DISABLED)) { 7595 /* drain_syncq will take care of events in the list */ 7596 drain_syncq(sq); 7597 return; 7598 } else if (flags & SQ_QUEUED) { 7599 sqenable(sq); 7600 } 7601 } 7602 /* Drop the SQLOCK on exit */ 7603 mutex_exit(SQLOCK(sq)); 7604 TRACE_3(TR_FAC_STREAMS_FR, TR_PUTNEXT_END, 7605 "putnext_end:(%p, %p, %p) done", NULL, qp, sq); 7606 } 7607 7608 void 7609 set_qend(queue_t *q) 7610 { 7611 mutex_enter(QLOCK(q)); 7612 if (!O_SAMESTR(q)) 7613 q->q_flag |= QEND; 7614 else 7615 q->q_flag &= ~QEND; 7616 mutex_exit(QLOCK(q)); 7617 q = _OTHERQ(q); 7618 mutex_enter(QLOCK(q)); 7619 if (!O_SAMESTR(q)) 7620 q->q_flag |= QEND; 7621 else 7622 q->q_flag &= ~QEND; 7623 mutex_exit(QLOCK(q)); 7624 } 7625 7626 /* 7627 * Set QFULL in next service procedure queue (that cares) if not already 7628 * set and if there are already more messages on the syncq than 7629 * sq_max_size. If sq_max_size is 0, no flow control will be asserted on 7630 * any syncq. 7631 * 7632 * The fq here is the next queue with a service procedure. This is where 7633 * we would fail canputnext, so this is where we need to set QFULL. 7634 * In the case when fq != q we need to take QLOCK(fq) to set QFULL flag. 7635 * 7636 * We already have QLOCK at this point. To avoid cross-locks with 7637 * freezestr() which grabs all QLOCKs and with strlock() which grabs both 7638 * SQLOCK and sd_reflock, we need to drop respective locks first. 7639 */ 7640 void 7641 set_qfull(queue_t *q) 7642 { 7643 queue_t *fq = NULL; 7644 7645 ASSERT(MUTEX_HELD(QLOCK(q))); 7646 if ((sq_max_size != 0) && (!(q->q_nfsrv->q_flag & QFULL)) && 7647 (q->q_syncqmsgs > sq_max_size)) { 7648 if ((fq = q->q_nfsrv) == q) { 7649 fq->q_flag |= QFULL; 7650 } else { 7651 mutex_exit(QLOCK(q)); 7652 mutex_enter(QLOCK(fq)); 7653 fq->q_flag |= QFULL; 7654 mutex_exit(QLOCK(fq)); 7655 mutex_enter(QLOCK(q)); 7656 } 7657 } 7658 } 7659 7660 void 7661 clr_qfull(queue_t *q) 7662 { 7663 queue_t *oq = q; 7664 7665 q = q->q_nfsrv; 7666 /* Fast check if there is any work to do before getting the lock. */ 7667 if ((q->q_flag & (QFULL|QWANTW)) == 0) { 7668 return; 7669 } 7670 7671 /* 7672 * Do not reset QFULL (and backenable) if the q_count is the reason 7673 * for QFULL being set. 7674 */ 7675 mutex_enter(QLOCK(q)); 7676 /* 7677 * If queue is empty i.e q_mblkcnt is zero, queue can not be full. 7678 * Hence clear the QFULL. 7679 * If both q_count and q_mblkcnt are less than the hiwat mark, 7680 * clear the QFULL. 7681 */ 7682 if (q->q_mblkcnt == 0 || ((q->q_count < q->q_hiwat) && 7683 (q->q_mblkcnt < q->q_hiwat))) { 7684 q->q_flag &= ~QFULL; 7685 /* 7686 * A little more confusing, how about this way: 7687 * if someone wants to write, 7688 * AND 7689 * both counts are less than the lowat mark 7690 * OR 7691 * the lowat mark is zero 7692 * THEN 7693 * backenable 7694 */ 7695 if ((q->q_flag & QWANTW) && 7696 (((q->q_count < q->q_lowat) && 7697 (q->q_mblkcnt < q->q_lowat)) || q->q_lowat == 0)) { 7698 q->q_flag &= ~QWANTW; 7699 mutex_exit(QLOCK(q)); 7700 backenable(oq, 0); 7701 } else 7702 mutex_exit(QLOCK(q)); 7703 } else 7704 mutex_exit(QLOCK(q)); 7705 } 7706 7707 /* 7708 * Set the forward service procedure pointer. 7709 * 7710 * Called at insert-time to cache a queue's next forward service procedure in 7711 * q_nfsrv; used by canput() and canputnext(). If the queue to be inserted 7712 * has a service procedure then q_nfsrv points to itself. If the queue to be 7713 * inserted does not have a service procedure, then q_nfsrv points to the next 7714 * queue forward that has a service procedure. If the queue is at the logical 7715 * end of the stream (driver for write side, stream head for the read side) 7716 * and does not have a service procedure, then q_nfsrv also points to itself. 7717 */ 7718 void 7719 set_nfsrv_ptr( 7720 queue_t *rnew, /* read queue pointer to new module */ 7721 queue_t *wnew, /* write queue pointer to new module */ 7722 queue_t *prev_rq, /* read queue pointer to the module above */ 7723 queue_t *prev_wq) /* write queue pointer to the module above */ 7724 { 7725 queue_t *qp; 7726 7727 if (prev_wq->q_next == NULL) { 7728 /* 7729 * Insert the driver, initialize the driver and stream head. 7730 * In this case, prev_rq/prev_wq should be the stream head. 7731 * _I_INSERT does not allow inserting a driver. Make sure 7732 * that it is not an insertion. 7733 */ 7734 ASSERT(!(rnew->q_flag & _QINSERTING)); 7735 wnew->q_nfsrv = wnew; 7736 if (rnew->q_qinfo->qi_srvp) 7737 rnew->q_nfsrv = rnew; 7738 else 7739 rnew->q_nfsrv = prev_rq; 7740 prev_rq->q_nfsrv = prev_rq; 7741 prev_wq->q_nfsrv = prev_wq; 7742 } else { 7743 /* 7744 * set up read side q_nfsrv pointer. This MUST be done 7745 * before setting the write side, because the setting of 7746 * the write side for a fifo may depend on it. 7747 * 7748 * Suppose we have a fifo that only has pipemod pushed. 7749 * pipemod has no read or write service procedures, so 7750 * nfsrv for both pipemod queues points to prev_rq (the 7751 * stream read head). Now push bufmod (which has only a 7752 * read service procedure). Doing the write side first, 7753 * wnew->q_nfsrv is set to pipemod's writeq nfsrv, which 7754 * is WRONG; the next queue forward from wnew with a 7755 * service procedure will be rnew, not the stream read head. 7756 * Since the downstream queue (which in the case of a fifo 7757 * is the read queue rnew) can affect upstream queues, it 7758 * needs to be done first. Setting up the read side first 7759 * sets nfsrv for both pipemod queues to rnew and then 7760 * when the write side is set up, wnew-q_nfsrv will also 7761 * point to rnew. 7762 */ 7763 if (rnew->q_qinfo->qi_srvp) { 7764 /* 7765 * use _OTHERQ() because, if this is a pipe, next 7766 * module may have been pushed from other end and 7767 * q_next could be a read queue. 7768 */ 7769 qp = _OTHERQ(prev_wq->q_next); 7770 while (qp && qp->q_nfsrv != qp) { 7771 qp->q_nfsrv = rnew; 7772 qp = backq(qp); 7773 } 7774 rnew->q_nfsrv = rnew; 7775 } else 7776 rnew->q_nfsrv = prev_rq->q_nfsrv; 7777 7778 /* set up write side q_nfsrv pointer */ 7779 if (wnew->q_qinfo->qi_srvp) { 7780 wnew->q_nfsrv = wnew; 7781 7782 /* 7783 * For insertion, need to update nfsrv of the modules 7784 * above which do not have a service routine. 7785 */ 7786 if (rnew->q_flag & _QINSERTING) { 7787 for (qp = prev_wq; 7788 qp != NULL && qp->q_nfsrv != qp; 7789 qp = backq(qp)) { 7790 qp->q_nfsrv = wnew->q_nfsrv; 7791 } 7792 } 7793 } else { 7794 if (prev_wq->q_next == prev_rq) 7795 /* 7796 * Since prev_wq/prev_rq are the middle of a 7797 * fifo, wnew/rnew will also be the middle of 7798 * a fifo and wnew's nfsrv is same as rnew's. 7799 */ 7800 wnew->q_nfsrv = rnew->q_nfsrv; 7801 else 7802 wnew->q_nfsrv = prev_wq->q_next->q_nfsrv; 7803 } 7804 } 7805 } 7806 7807 /* 7808 * Reset the forward service procedure pointer; called at remove-time. 7809 */ 7810 void 7811 reset_nfsrv_ptr(queue_t *rqp, queue_t *wqp) 7812 { 7813 queue_t *tmp_qp; 7814 7815 /* Reset the write side q_nfsrv pointer for _I_REMOVE */ 7816 if ((rqp->q_flag & _QREMOVING) && (wqp->q_qinfo->qi_srvp != NULL)) { 7817 for (tmp_qp = backq(wqp); 7818 tmp_qp != NULL && tmp_qp->q_nfsrv == wqp; 7819 tmp_qp = backq(tmp_qp)) { 7820 tmp_qp->q_nfsrv = wqp->q_nfsrv; 7821 } 7822 } 7823 7824 /* reset the read side q_nfsrv pointer */ 7825 if (rqp->q_qinfo->qi_srvp) { 7826 if (wqp->q_next) { /* non-driver case */ 7827 tmp_qp = _OTHERQ(wqp->q_next); 7828 while (tmp_qp && tmp_qp->q_nfsrv == rqp) { 7829 /* Note that rqp->q_next cannot be NULL */ 7830 ASSERT(rqp->q_next != NULL); 7831 tmp_qp->q_nfsrv = rqp->q_next->q_nfsrv; 7832 tmp_qp = backq(tmp_qp); 7833 } 7834 } 7835 } 7836 } 7837 7838 /* 7839 * This routine should be called after all stream geometry changes to update 7840 * the stream head cached struio() rd/wr queue pointers. Note must be called 7841 * with the streamlock()ed. 7842 * 7843 * Note: only enables Synchronous STREAMS for a side of a Stream which has 7844 * an explicit synchronous barrier module queue. That is, a queue that 7845 * has specified a struio() type. 7846 */ 7847 static void 7848 strsetuio(stdata_t *stp) 7849 { 7850 queue_t *wrq; 7851 7852 if (stp->sd_flag & STPLEX) { 7853 /* 7854 * Not streamhead, but a mux, so no Synchronous STREAMS. 7855 */ 7856 stp->sd_struiowrq = NULL; 7857 stp->sd_struiordq = NULL; 7858 return; 7859 } 7860 /* 7861 * Scan the write queue(s) while synchronous 7862 * until we find a qinfo uio type specified. 7863 */ 7864 wrq = stp->sd_wrq->q_next; 7865 while (wrq) { 7866 if (wrq->q_struiot == STRUIOT_NONE) { 7867 wrq = 0; 7868 break; 7869 } 7870 if (wrq->q_struiot != STRUIOT_DONTCARE) 7871 break; 7872 if (! _SAMESTR(wrq)) { 7873 wrq = 0; 7874 break; 7875 } 7876 wrq = wrq->q_next; 7877 } 7878 stp->sd_struiowrq = wrq; 7879 /* 7880 * Scan the read queue(s) while synchronous 7881 * until we find a qinfo uio type specified. 7882 */ 7883 wrq = stp->sd_wrq->q_next; 7884 while (wrq) { 7885 if (_RD(wrq)->q_struiot == STRUIOT_NONE) { 7886 wrq = 0; 7887 break; 7888 } 7889 if (_RD(wrq)->q_struiot != STRUIOT_DONTCARE) 7890 break; 7891 if (! _SAMESTR(wrq)) { 7892 wrq = 0; 7893 break; 7894 } 7895 wrq = wrq->q_next; 7896 } 7897 stp->sd_struiordq = wrq ? _RD(wrq) : 0; 7898 } 7899 7900 /* 7901 * pass_wput, unblocks the passthru queues, so that 7902 * messages can arrive at muxs lower read queue, before 7903 * I_LINK/I_UNLINK is acked/nacked. 7904 */ 7905 static void 7906 pass_wput(queue_t *q, mblk_t *mp) 7907 { 7908 syncq_t *sq; 7909 7910 sq = _RD(q)->q_syncq; 7911 if (sq->sq_flags & SQ_BLOCKED) 7912 unblocksq(sq, SQ_BLOCKED, 0); 7913 putnext(q, mp); 7914 } 7915 7916 /* 7917 * Set up queues for the link/unlink. 7918 * Create a new queue and block it and then insert it 7919 * below the stream head on the lower stream. 7920 * This prevents any messages from arriving during the setq 7921 * as well as while the mux is processing the LINK/I_UNLINK. 7922 * The blocked passq is unblocked once the LINK/I_UNLINK has 7923 * been acked or nacked or if a message is generated and sent 7924 * down muxs write put procedure. 7925 * See pass_wput(). 7926 * 7927 * After the new queue is inserted, all messages coming from below are 7928 * blocked. The call to strlock will ensure that all activity in the stream head 7929 * read queue syncq is stopped (sq_count drops to zero). 7930 */ 7931 static queue_t * 7932 link_addpassthru(stdata_t *stpdown) 7933 { 7934 queue_t *passq; 7935 sqlist_t sqlist; 7936 7937 passq = allocq(); 7938 STREAM(passq) = STREAM(_WR(passq)) = stpdown; 7939 /* setq might sleep in allocator - avoid holding locks. */ 7940 setq(passq, &passthru_rinit, &passthru_winit, NULL, QPERQ, 7941 SQ_CI|SQ_CO, B_FALSE); 7942 claimq(passq); 7943 blocksq(passq->q_syncq, SQ_BLOCKED, 1); 7944 insertq(STREAM(passq), passq); 7945 7946 /* 7947 * Use strlock() to wait for the stream head sq_count to drop to zero 7948 * since we are going to change q_ptr in the stream head. Note that 7949 * insertq() doesn't wait for any syncq counts to drop to zero. 7950 */ 7951 sqlist.sqlist_head = NULL; 7952 sqlist.sqlist_index = 0; 7953 sqlist.sqlist_size = sizeof (sqlist_t); 7954 sqlist_insert(&sqlist, _RD(stpdown->sd_wrq)->q_syncq); 7955 strlock(stpdown, &sqlist); 7956 strunlock(stpdown, &sqlist); 7957 7958 releaseq(passq); 7959 return (passq); 7960 } 7961 7962 /* 7963 * Let messages flow up into the mux by removing 7964 * the passq. 7965 */ 7966 static void 7967 link_rempassthru(queue_t *passq) 7968 { 7969 claimq(passq); 7970 removeq(passq); 7971 releaseq(passq); 7972 freeq(passq); 7973 } 7974 7975 /* 7976 * Wait for the condition variable pointed to by `cvp' to be signaled, 7977 * or for `tim' milliseconds to elapse, whichever comes first. If `tim' 7978 * is negative, then there is no time limit. If `nosigs' is non-zero, 7979 * then the wait will be non-interruptible. 7980 * 7981 * Returns >0 if signaled, 0 if interrupted, or -1 upon timeout. 7982 */ 7983 clock_t 7984 str_cv_wait(kcondvar_t *cvp, kmutex_t *mp, clock_t tim, int nosigs) 7985 { 7986 clock_t ret; 7987 7988 if (tim < 0) { 7989 if (nosigs) { 7990 cv_wait(cvp, mp); 7991 ret = 1; 7992 } else { 7993 ret = cv_wait_sig(cvp, mp); 7994 } 7995 } else if (tim > 0) { 7996 /* 7997 * convert milliseconds to clock ticks 7998 */ 7999 if (nosigs) { 8000 ret = cv_reltimedwait(cvp, mp, 8001 MSEC_TO_TICK_ROUNDUP(tim), TR_CLOCK_TICK); 8002 } else { 8003 ret = cv_reltimedwait_sig(cvp, mp, 8004 MSEC_TO_TICK_ROUNDUP(tim), TR_CLOCK_TICK); 8005 } 8006 } else { 8007 ret = -1; 8008 } 8009 return (ret); 8010 } 8011 8012 /* 8013 * Wait until the stream head can determine if it is at the mark but 8014 * don't wait forever to prevent a race condition between the "mark" state 8015 * in the stream head and any mark state in the caller/user of this routine. 8016 * 8017 * This is used by sockets and for a socket it would be incorrect 8018 * to return a failure for SIOCATMARK when there is no data in the receive 8019 * queue and the marked urgent data is traveling up the stream. 8020 * 8021 * This routine waits until the mark is known by waiting for one of these 8022 * three events: 8023 * The stream head read queue becoming non-empty (including an EOF). 8024 * The STRATMARK flag being set (due to a MSGMARKNEXT message). 8025 * The STRNOTATMARK flag being set (which indicates that the transport 8026 * has sent a MSGNOTMARKNEXT message to indicate that it is not at 8027 * the mark). 8028 * 8029 * The routine returns 1 if the stream is at the mark; 0 if it can 8030 * be determined that the stream is not at the mark. 8031 * If the wait times out and it can't determine 8032 * whether or not the stream might be at the mark the routine will return -1. 8033 * 8034 * Note: This routine should only be used when a mark is pending i.e., 8035 * in the socket case the SIGURG has been posted. 8036 * Note2: This can not wakeup just because synchronous streams indicate 8037 * that data is available since it is not possible to use the synchronous 8038 * streams interfaces to determine the b_flag value for the data queued below 8039 * the stream head. 8040 */ 8041 int 8042 strwaitmark(vnode_t *vp) 8043 { 8044 struct stdata *stp = vp->v_stream; 8045 queue_t *rq = _RD(stp->sd_wrq); 8046 int mark; 8047 8048 mutex_enter(&stp->sd_lock); 8049 while (rq->q_first == NULL && 8050 !(stp->sd_flag & (STRATMARK|STRNOTATMARK|STREOF))) { 8051 stp->sd_flag |= RSLEEP; 8052 8053 /* Wait for 100 milliseconds for any state change. */ 8054 if (str_cv_wait(&rq->q_wait, &stp->sd_lock, 100, 1) == -1) { 8055 mutex_exit(&stp->sd_lock); 8056 return (-1); 8057 } 8058 } 8059 if (stp->sd_flag & STRATMARK) 8060 mark = 1; 8061 else if (rq->q_first != NULL && (rq->q_first->b_flag & MSGMARK)) 8062 mark = 1; 8063 else 8064 mark = 0; 8065 8066 mutex_exit(&stp->sd_lock); 8067 return (mark); 8068 } 8069 8070 /* 8071 * Set a read side error. If persist is set change the socket error 8072 * to persistent. If errfunc is set install the function as the exported 8073 * error handler. 8074 */ 8075 void 8076 strsetrerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) 8077 { 8078 struct stdata *stp = vp->v_stream; 8079 8080 mutex_enter(&stp->sd_lock); 8081 stp->sd_rerror = error; 8082 if (error == 0 && errfunc == NULL) 8083 stp->sd_flag &= ~STRDERR; 8084 else 8085 stp->sd_flag |= STRDERR; 8086 if (persist) { 8087 stp->sd_flag &= ~STRDERRNONPERSIST; 8088 } else { 8089 stp->sd_flag |= STRDERRNONPERSIST; 8090 } 8091 stp->sd_rderrfunc = errfunc; 8092 if (error != 0 || errfunc != NULL) { 8093 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ 8094 cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ 8095 cv_broadcast(&stp->sd_monitor); /* ioctllers */ 8096 8097 mutex_exit(&stp->sd_lock); 8098 pollwakeup(&stp->sd_pollist, POLLERR); 8099 mutex_enter(&stp->sd_lock); 8100 8101 if (stp->sd_sigflags & S_ERROR) 8102 strsendsig(stp->sd_siglist, S_ERROR, 0, error); 8103 } 8104 mutex_exit(&stp->sd_lock); 8105 } 8106 8107 /* 8108 * Set a write side error. If persist is set change the socket error 8109 * to persistent. 8110 */ 8111 void 8112 strsetwerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) 8113 { 8114 struct stdata *stp = vp->v_stream; 8115 8116 mutex_enter(&stp->sd_lock); 8117 stp->sd_werror = error; 8118 if (error == 0 && errfunc == NULL) 8119 stp->sd_flag &= ~STWRERR; 8120 else 8121 stp->sd_flag |= STWRERR; 8122 if (persist) { 8123 stp->sd_flag &= ~STWRERRNONPERSIST; 8124 } else { 8125 stp->sd_flag |= STWRERRNONPERSIST; 8126 } 8127 stp->sd_wrerrfunc = errfunc; 8128 if (error != 0 || errfunc != NULL) { 8129 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ 8130 cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ 8131 cv_broadcast(&stp->sd_monitor); /* ioctllers */ 8132 8133 mutex_exit(&stp->sd_lock); 8134 pollwakeup(&stp->sd_pollist, POLLERR); 8135 mutex_enter(&stp->sd_lock); 8136 8137 if (stp->sd_sigflags & S_ERROR) 8138 strsendsig(stp->sd_siglist, S_ERROR, 0, error); 8139 } 8140 mutex_exit(&stp->sd_lock); 8141 } 8142 8143 /* 8144 * Make the stream return 0 (EOF) when all data has been read. 8145 * No effect on write side. 8146 */ 8147 void 8148 strseteof(vnode_t *vp, int eof) 8149 { 8150 struct stdata *stp = vp->v_stream; 8151 8152 mutex_enter(&stp->sd_lock); 8153 if (!eof) { 8154 stp->sd_flag &= ~STREOF; 8155 mutex_exit(&stp->sd_lock); 8156 return; 8157 } 8158 stp->sd_flag |= STREOF; 8159 if (stp->sd_flag & RSLEEP) { 8160 stp->sd_flag &= ~RSLEEP; 8161 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); 8162 } 8163 8164 mutex_exit(&stp->sd_lock); 8165 pollwakeup(&stp->sd_pollist, POLLIN|POLLRDNORM); 8166 mutex_enter(&stp->sd_lock); 8167 8168 if (stp->sd_sigflags & (S_INPUT|S_RDNORM)) 8169 strsendsig(stp->sd_siglist, S_INPUT|S_RDNORM, 0, 0); 8170 mutex_exit(&stp->sd_lock); 8171 } 8172 8173 void 8174 strflushrq(vnode_t *vp, int flag) 8175 { 8176 struct stdata *stp = vp->v_stream; 8177 8178 mutex_enter(&stp->sd_lock); 8179 flushq(_RD(stp->sd_wrq), flag); 8180 mutex_exit(&stp->sd_lock); 8181 } 8182 8183 void 8184 strsetrputhooks(vnode_t *vp, uint_t flags, 8185 msgfunc_t protofunc, msgfunc_t miscfunc) 8186 { 8187 struct stdata *stp = vp->v_stream; 8188 8189 mutex_enter(&stp->sd_lock); 8190 8191 if (protofunc == NULL) 8192 stp->sd_rprotofunc = strrput_proto; 8193 else 8194 stp->sd_rprotofunc = protofunc; 8195 8196 if (miscfunc == NULL) 8197 stp->sd_rmiscfunc = strrput_misc; 8198 else 8199 stp->sd_rmiscfunc = miscfunc; 8200 8201 if (flags & SH_CONSOL_DATA) 8202 stp->sd_rput_opt |= SR_CONSOL_DATA; 8203 else 8204 stp->sd_rput_opt &= ~SR_CONSOL_DATA; 8205 8206 if (flags & SH_SIGALLDATA) 8207 stp->sd_rput_opt |= SR_SIGALLDATA; 8208 else 8209 stp->sd_rput_opt &= ~SR_SIGALLDATA; 8210 8211 if (flags & SH_IGN_ZEROLEN) 8212 stp->sd_rput_opt |= SR_IGN_ZEROLEN; 8213 else 8214 stp->sd_rput_opt &= ~SR_IGN_ZEROLEN; 8215 8216 mutex_exit(&stp->sd_lock); 8217 } 8218 8219 void 8220 strsetwputhooks(vnode_t *vp, uint_t flags, clock_t closetime) 8221 { 8222 struct stdata *stp = vp->v_stream; 8223 8224 mutex_enter(&stp->sd_lock); 8225 stp->sd_closetime = closetime; 8226 8227 if (flags & SH_SIGPIPE) 8228 stp->sd_wput_opt |= SW_SIGPIPE; 8229 else 8230 stp->sd_wput_opt &= ~SW_SIGPIPE; 8231 if (flags & SH_RECHECK_ERR) 8232 stp->sd_wput_opt |= SW_RECHECK_ERR; 8233 else 8234 stp->sd_wput_opt &= ~SW_RECHECK_ERR; 8235 8236 mutex_exit(&stp->sd_lock); 8237 } 8238 8239 void 8240 strsetrwputdatahooks(vnode_t *vp, msgfunc_t rdatafunc, msgfunc_t wdatafunc) 8241 { 8242 struct stdata *stp = vp->v_stream; 8243 8244 mutex_enter(&stp->sd_lock); 8245 8246 stp->sd_rputdatafunc = rdatafunc; 8247 stp->sd_wputdatafunc = wdatafunc; 8248 8249 mutex_exit(&stp->sd_lock); 8250 } 8251 8252 /* Used within framework when the queue is already locked */ 8253 void 8254 qenable_locked(queue_t *q) 8255 { 8256 stdata_t *stp = STREAM(q); 8257 8258 ASSERT(MUTEX_HELD(QLOCK(q))); 8259 8260 if (!q->q_qinfo->qi_srvp) 8261 return; 8262 8263 /* 8264 * Do not place on run queue if already enabled or closing. 8265 */ 8266 if (q->q_flag & (QWCLOSE|QENAB)) 8267 return; 8268 8269 /* 8270 * mark queue enabled and place on run list if it is not already being 8271 * serviced. If it is serviced, the runservice() function will detect 8272 * that QENAB is set and call service procedure before clearing 8273 * QINSERVICE flag. 8274 */ 8275 q->q_flag |= QENAB; 8276 if (q->q_flag & QINSERVICE) 8277 return; 8278 8279 /* Record the time of qenable */ 8280 q->q_qtstamp = ddi_get_lbolt(); 8281 8282 /* 8283 * Put the queue in the stp list and schedule it for background 8284 * processing if it is not already scheduled or if stream head does not 8285 * intent to process it in the foreground later by setting 8286 * STRS_WILLSERVICE flag. 8287 */ 8288 mutex_enter(&stp->sd_qlock); 8289 /* 8290 * If there are already something on the list, stp flags should show 8291 * intention to drain it. 8292 */ 8293 IMPLY(STREAM_NEEDSERVICE(stp), 8294 (stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))); 8295 8296 ENQUEUE(q, stp->sd_qhead, stp->sd_qtail, q_link); 8297 stp->sd_nqueues++; 8298 8299 /* 8300 * If no one will drain this stream we are the first producer and 8301 * need to schedule it for background thread. 8302 */ 8303 if (!(stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))) { 8304 /* 8305 * No one will service this stream later, so we have to 8306 * schedule it now. 8307 */ 8308 STRSTAT(stenables); 8309 stp->sd_svcflags |= STRS_SCHEDULED; 8310 stp->sd_servid = (void *)taskq_dispatch(streams_taskq, 8311 (task_func_t *)stream_service, stp, TQ_NOSLEEP|TQ_NOQUEUE); 8312 8313 if (stp->sd_servid == NULL) { 8314 /* 8315 * Task queue failed so fail over to the backup 8316 * servicing thread. 8317 */ 8318 STRSTAT(taskqfails); 8319 /* 8320 * It is safe to clear STRS_SCHEDULED flag because it 8321 * was set by this thread above. 8322 */ 8323 stp->sd_svcflags &= ~STRS_SCHEDULED; 8324 8325 /* 8326 * Failover scheduling is protected by service_queue 8327 * lock. 8328 */ 8329 mutex_enter(&service_queue); 8330 ASSERT((stp->sd_qhead == q) && (stp->sd_qtail == q)); 8331 ASSERT(q->q_link == NULL); 8332 /* 8333 * Append the queue to qhead/qtail list. 8334 */ 8335 if (qhead == NULL) 8336 qhead = q; 8337 else 8338 qtail->q_link = q; 8339 qtail = q; 8340 /* 8341 * Clear stp queue list. 8342 */ 8343 stp->sd_qhead = stp->sd_qtail = NULL; 8344 stp->sd_nqueues = 0; 8345 /* 8346 * Wakeup background queue processing thread. 8347 */ 8348 cv_signal(&services_to_run); 8349 mutex_exit(&service_queue); 8350 } 8351 } 8352 mutex_exit(&stp->sd_qlock); 8353 } 8354 8355 static void 8356 queue_service(queue_t *q) 8357 { 8358 /* 8359 * The queue in the list should have 8360 * QENAB flag set and should not have 8361 * QINSERVICE flag set. QINSERVICE is 8362 * set when the queue is dequeued and 8363 * qenable_locked doesn't enqueue a 8364 * queue with QINSERVICE set. 8365 */ 8366 8367 ASSERT(!(q->q_flag & QINSERVICE)); 8368 ASSERT((q->q_flag & QENAB)); 8369 mutex_enter(QLOCK(q)); 8370 q->q_flag &= ~QENAB; 8371 q->q_flag |= QINSERVICE; 8372 mutex_exit(QLOCK(q)); 8373 runservice(q); 8374 } 8375 8376 static void 8377 syncq_service(syncq_t *sq) 8378 { 8379 STRSTAT(syncqservice); 8380 mutex_enter(SQLOCK(sq)); 8381 ASSERT(!(sq->sq_svcflags & SQ_SERVICE)); 8382 ASSERT(sq->sq_servcount != 0); 8383 ASSERT(sq->sq_next == NULL); 8384 8385 /* if we came here from the background thread, clear the flag */ 8386 if (sq->sq_svcflags & SQ_BGTHREAD) 8387 sq->sq_svcflags &= ~SQ_BGTHREAD; 8388 8389 /* let drain_syncq know that it's being called in the background */ 8390 sq->sq_svcflags |= SQ_SERVICE; 8391 drain_syncq(sq); 8392 } 8393 8394 static void 8395 qwriter_outer_service(syncq_t *outer) 8396 { 8397 /* 8398 * Note that SQ_WRITER is used on the outer perimeter 8399 * to signal that a qwriter(OUTER) is either investigating 8400 * running or that it is actually running a function. 8401 */ 8402 outer_enter(outer, SQ_BLOCKED|SQ_WRITER); 8403 8404 /* 8405 * All inner syncq are empty and have SQ_WRITER set 8406 * to block entering the outer perimeter. 8407 * 8408 * We do not need to explicitly call write_now since 8409 * outer_exit does it for us. 8410 */ 8411 outer_exit(outer); 8412 } 8413 8414 static void 8415 mblk_free(mblk_t *mp) 8416 { 8417 dblk_t *dbp = mp->b_datap; 8418 frtn_t *frp = dbp->db_frtnp; 8419 8420 mp->b_next = NULL; 8421 if (dbp->db_fthdr != NULL) 8422 str_ftfree(dbp); 8423 8424 ASSERT(dbp->db_fthdr == NULL); 8425 frp->free_func(frp->free_arg); 8426 ASSERT(dbp->db_mblk == mp); 8427 8428 if (dbp->db_credp != NULL) { 8429 crfree(dbp->db_credp); 8430 dbp->db_credp = NULL; 8431 } 8432 dbp->db_cpid = -1; 8433 dbp->db_struioflag = 0; 8434 dbp->db_struioun.cksum.flags = 0; 8435 8436 kmem_cache_free(dbp->db_cache, dbp); 8437 } 8438 8439 /* 8440 * Background processing of the stream queue list. 8441 */ 8442 static void 8443 stream_service(stdata_t *stp) 8444 { 8445 queue_t *q; 8446 8447 mutex_enter(&stp->sd_qlock); 8448 8449 STR_SERVICE(stp, q); 8450 8451 stp->sd_svcflags &= ~STRS_SCHEDULED; 8452 stp->sd_servid = NULL; 8453 cv_signal(&stp->sd_qcv); 8454 mutex_exit(&stp->sd_qlock); 8455 } 8456 8457 /* 8458 * Foreground processing of the stream queue list. 8459 */ 8460 void 8461 stream_runservice(stdata_t *stp) 8462 { 8463 queue_t *q; 8464 8465 mutex_enter(&stp->sd_qlock); 8466 STRSTAT(rservice); 8467 /* 8468 * We are going to drain this stream queue list, so qenable_locked will 8469 * not schedule it until we finish. 8470 */ 8471 stp->sd_svcflags |= STRS_WILLSERVICE; 8472 8473 STR_SERVICE(stp, q); 8474 8475 stp->sd_svcflags &= ~STRS_WILLSERVICE; 8476 mutex_exit(&stp->sd_qlock); 8477 /* 8478 * Help backup background thread to drain the qhead/qtail list. 8479 */ 8480 while (qhead != NULL) { 8481 STRSTAT(qhelps); 8482 mutex_enter(&service_queue); 8483 DQ(q, qhead, qtail, q_link); 8484 mutex_exit(&service_queue); 8485 if (q != NULL) 8486 queue_service(q); 8487 } 8488 } 8489 8490 void 8491 stream_willservice(stdata_t *stp) 8492 { 8493 mutex_enter(&stp->sd_qlock); 8494 stp->sd_svcflags |= STRS_WILLSERVICE; 8495 mutex_exit(&stp->sd_qlock); 8496 } 8497 8498 /* 8499 * Replace the cred currently in the mblk with a different one. 8500 * Also update db_cpid. 8501 */ 8502 void 8503 mblk_setcred(mblk_t *mp, cred_t *cr, pid_t cpid) 8504 { 8505 dblk_t *dbp = mp->b_datap; 8506 cred_t *ocr = dbp->db_credp; 8507 8508 ASSERT(cr != NULL); 8509 8510 if (cr != ocr) { 8511 crhold(dbp->db_credp = cr); 8512 if (ocr != NULL) 8513 crfree(ocr); 8514 } 8515 /* Don't overwrite with NOPID */ 8516 if (cpid != NOPID) 8517 dbp->db_cpid = cpid; 8518 } 8519 8520 /* 8521 * If the src message has a cred, then replace the cred currently in the mblk 8522 * with it. 8523 * Also update db_cpid. 8524 */ 8525 void 8526 mblk_copycred(mblk_t *mp, const mblk_t *src) 8527 { 8528 dblk_t *dbp = mp->b_datap; 8529 cred_t *cr, *ocr; 8530 pid_t cpid; 8531 8532 cr = msg_getcred(src, &cpid); 8533 if (cr == NULL) 8534 return; 8535 8536 ocr = dbp->db_credp; 8537 if (cr != ocr) { 8538 crhold(dbp->db_credp = cr); 8539 if (ocr != NULL) 8540 crfree(ocr); 8541 } 8542 /* Don't overwrite with NOPID */ 8543 if (cpid != NOPID) 8544 dbp->db_cpid = cpid; 8545 } 8546 8547 int 8548 hcksum_assoc(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, 8549 uint32_t start, uint32_t stuff, uint32_t end, uint32_t value, 8550 uint32_t flags, int km_flags) 8551 { 8552 int rc = 0; 8553 8554 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8555 if (mp->b_datap->db_type == M_DATA) { 8556 /* Associate values for M_DATA type */ 8557 DB_CKSUMSTART(mp) = (intptr_t)start; 8558 DB_CKSUMSTUFF(mp) = (intptr_t)stuff; 8559 DB_CKSUMEND(mp) = (intptr_t)end; 8560 DB_CKSUMFLAGS(mp) = flags; 8561 DB_CKSUM16(mp) = (uint16_t)value; 8562 8563 } else { 8564 pattrinfo_t pa_info; 8565 8566 ASSERT(mmd != NULL); 8567 8568 pa_info.type = PATTR_HCKSUM; 8569 pa_info.len = sizeof (pattr_hcksum_t); 8570 8571 if (mmd_addpattr(mmd, pd, &pa_info, B_TRUE, km_flags) != NULL) { 8572 pattr_hcksum_t *hck = (pattr_hcksum_t *)pa_info.buf; 8573 8574 hck->hcksum_start_offset = start; 8575 hck->hcksum_stuff_offset = stuff; 8576 hck->hcksum_end_offset = end; 8577 hck->hcksum_cksum_val.inet_cksum = (uint16_t)value; 8578 hck->hcksum_flags = flags; 8579 } else { 8580 rc = -1; 8581 } 8582 } 8583 return (rc); 8584 } 8585 8586 void 8587 hcksum_retrieve(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, 8588 uint32_t *start, uint32_t *stuff, uint32_t *end, 8589 uint32_t *value, uint32_t *flags) 8590 { 8591 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8592 if (mp->b_datap->db_type == M_DATA) { 8593 if (flags != NULL) { 8594 *flags = DB_CKSUMFLAGS(mp) & HCK_FLAGS; 8595 if ((*flags & (HCK_PARTIALCKSUM | 8596 HCK_FULLCKSUM)) != 0) { 8597 if (value != NULL) 8598 *value = (uint32_t)DB_CKSUM16(mp); 8599 if ((*flags & HCK_PARTIALCKSUM) != 0) { 8600 if (start != NULL) 8601 *start = 8602 (uint32_t)DB_CKSUMSTART(mp); 8603 if (stuff != NULL) 8604 *stuff = 8605 (uint32_t)DB_CKSUMSTUFF(mp); 8606 if (end != NULL) 8607 *end = 8608 (uint32_t)DB_CKSUMEND(mp); 8609 } 8610 } 8611 } 8612 } else { 8613 pattrinfo_t hck_attr = {PATTR_HCKSUM}; 8614 8615 ASSERT(mmd != NULL); 8616 8617 /* get hardware checksum attribute */ 8618 if (mmd_getpattr(mmd, pd, &hck_attr) != NULL) { 8619 pattr_hcksum_t *hck = (pattr_hcksum_t *)hck_attr.buf; 8620 8621 ASSERT(hck_attr.len >= sizeof (pattr_hcksum_t)); 8622 if (flags != NULL) 8623 *flags = hck->hcksum_flags; 8624 if (start != NULL) 8625 *start = hck->hcksum_start_offset; 8626 if (stuff != NULL) 8627 *stuff = hck->hcksum_stuff_offset; 8628 if (end != NULL) 8629 *end = hck->hcksum_end_offset; 8630 if (value != NULL) 8631 *value = (uint32_t) 8632 hck->hcksum_cksum_val.inet_cksum; 8633 } 8634 } 8635 } 8636 8637 void 8638 lso_info_set(mblk_t *mp, uint32_t mss, uint32_t flags) 8639 { 8640 ASSERT(DB_TYPE(mp) == M_DATA); 8641 ASSERT((flags & ~HW_LSO_FLAGS) == 0); 8642 8643 /* Set the flags */ 8644 DB_LSOFLAGS(mp) |= flags; 8645 DB_LSOMSS(mp) = mss; 8646 } 8647 8648 void 8649 lso_info_cleanup(mblk_t *mp) 8650 { 8651 ASSERT(DB_TYPE(mp) == M_DATA); 8652 8653 /* Clear the flags */ 8654 DB_LSOFLAGS(mp) &= ~HW_LSO_FLAGS; 8655 DB_LSOMSS(mp) = 0; 8656 } 8657 8658 /* 8659 * Checksum buffer *bp for len bytes with psum partial checksum, 8660 * or 0 if none, and return the 16 bit partial checksum. 8661 */ 8662 unsigned 8663 bcksum(uchar_t *bp, int len, unsigned int psum) 8664 { 8665 int odd = len & 1; 8666 extern unsigned int ip_ocsum(); 8667 8668 if (((intptr_t)bp & 1) == 0 && !odd) { 8669 /* 8670 * Bp is 16 bit aligned and len is multiple of 16 bit word. 8671 */ 8672 return (ip_ocsum((ushort_t *)bp, len >> 1, psum)); 8673 } 8674 if (((intptr_t)bp & 1) != 0) { 8675 /* 8676 * Bp isn't 16 bit aligned. 8677 */ 8678 unsigned int tsum; 8679 8680 #ifdef _LITTLE_ENDIAN 8681 psum += *bp; 8682 #else 8683 psum += *bp << 8; 8684 #endif 8685 len--; 8686 bp++; 8687 tsum = ip_ocsum((ushort_t *)bp, len >> 1, 0); 8688 psum += (tsum << 8) & 0xffff | (tsum >> 8); 8689 if (len & 1) { 8690 bp += len - 1; 8691 #ifdef _LITTLE_ENDIAN 8692 psum += *bp << 8; 8693 #else 8694 psum += *bp; 8695 #endif 8696 } 8697 } else { 8698 /* 8699 * Bp is 16 bit aligned. 8700 */ 8701 psum = ip_ocsum((ushort_t *)bp, len >> 1, psum); 8702 if (odd) { 8703 bp += len - 1; 8704 #ifdef _LITTLE_ENDIAN 8705 psum += *bp; 8706 #else 8707 psum += *bp << 8; 8708 #endif 8709 } 8710 } 8711 /* 8712 * Normalize psum to 16 bits before returning the new partial 8713 * checksum. The max psum value before normalization is 0x3FDFE. 8714 */ 8715 return ((psum >> 16) + (psum & 0xFFFF)); 8716 } 8717 8718 boolean_t 8719 is_vmloaned_mblk(mblk_t *mp, multidata_t *mmd, pdesc_t *pd) 8720 { 8721 boolean_t rc; 8722 8723 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8724 if (DB_TYPE(mp) == M_DATA) { 8725 rc = (((mp)->b_datap->db_struioflag & STRUIO_ZC) != 0); 8726 } else { 8727 pattrinfo_t zcopy_attr = {PATTR_ZCOPY}; 8728 8729 ASSERT(mmd != NULL); 8730 rc = (mmd_getpattr(mmd, pd, &zcopy_attr) != NULL); 8731 } 8732 return (rc); 8733 } 8734 8735 void 8736 freemsgchain(mblk_t *mp) 8737 { 8738 mblk_t *next; 8739 8740 while (mp != NULL) { 8741 next = mp->b_next; 8742 mp->b_next = NULL; 8743 8744 freemsg(mp); 8745 mp = next; 8746 } 8747 } 8748 8749 mblk_t * 8750 copymsgchain(mblk_t *mp) 8751 { 8752 mblk_t *nmp = NULL; 8753 mblk_t **nmpp = &nmp; 8754 8755 for (; mp != NULL; mp = mp->b_next) { 8756 if ((*nmpp = copymsg(mp)) == NULL) { 8757 freemsgchain(nmp); 8758 return (NULL); 8759 } 8760 8761 nmpp = &((*nmpp)->b_next); 8762 } 8763 8764 return (nmp); 8765 } 8766 8767 /* NOTE: Do not add code after this point. */ 8768 #undef QLOCK 8769 8770 /* 8771 * Replacement for QLOCK macro for those that can't use it. 8772 */ 8773 kmutex_t * 8774 QLOCK(queue_t *q) 8775 { 8776 return (&(q)->q_lock); 8777 } 8778 8779 /* 8780 * Dummy runqueues/queuerun functions functions for backwards compatibility. 8781 */ 8782 #undef runqueues 8783 void 8784 runqueues(void) 8785 { 8786 } 8787 8788 #undef queuerun 8789 void 8790 queuerun(void) 8791 { 8792 } 8793 8794 /* 8795 * Initialize the STR stack instance, which tracks autopush and persistent 8796 * links. 8797 */ 8798 /* ARGSUSED */ 8799 static void * 8800 str_stack_init(netstackid_t stackid, netstack_t *ns) 8801 { 8802 str_stack_t *ss; 8803 int i; 8804 8805 ss = (str_stack_t *)kmem_zalloc(sizeof (*ss), KM_SLEEP); 8806 ss->ss_netstack = ns; 8807 8808 /* 8809 * set up autopush 8810 */ 8811 sad_initspace(ss); 8812 8813 /* 8814 * set up mux_node structures. 8815 */ 8816 ss->ss_devcnt = devcnt; /* In case it should change before free */ 8817 ss->ss_mux_nodes = kmem_zalloc((sizeof (struct mux_node) * 8818 ss->ss_devcnt), KM_SLEEP); 8819 for (i = 0; i < ss->ss_devcnt; i++) 8820 ss->ss_mux_nodes[i].mn_imaj = i; 8821 return (ss); 8822 } 8823 8824 /* 8825 * Note: run at zone shutdown and not destroy so that the PLINKs are 8826 * gone by the time other cleanup happens from the destroy callbacks. 8827 */ 8828 static void 8829 str_stack_shutdown(netstackid_t stackid, void *arg) 8830 { 8831 str_stack_t *ss = (str_stack_t *)arg; 8832 int i; 8833 cred_t *cr; 8834 8835 cr = zone_get_kcred(netstackid_to_zoneid(stackid)); 8836 ASSERT(cr != NULL); 8837 8838 /* Undo all the I_PLINKs for this zone */ 8839 for (i = 0; i < ss->ss_devcnt; i++) { 8840 struct mux_edge *ep; 8841 ldi_handle_t lh; 8842 ldi_ident_t li; 8843 int ret; 8844 int rval; 8845 dev_t rdev; 8846 8847 ep = ss->ss_mux_nodes[i].mn_outp; 8848 if (ep == NULL) 8849 continue; 8850 ret = ldi_ident_from_major((major_t)i, &li); 8851 if (ret != 0) { 8852 continue; 8853 } 8854 rdev = ep->me_dev; 8855 ret = ldi_open_by_dev(&rdev, OTYP_CHR, FREAD|FWRITE, 8856 cr, &lh, li); 8857 if (ret != 0) { 8858 ldi_ident_release(li); 8859 continue; 8860 } 8861 8862 ret = ldi_ioctl(lh, I_PUNLINK, (intptr_t)MUXID_ALL, FKIOCTL, 8863 cr, &rval); 8864 if (ret) { 8865 (void) ldi_close(lh, FREAD|FWRITE, cr); 8866 ldi_ident_release(li); 8867 continue; 8868 } 8869 (void) ldi_close(lh, FREAD|FWRITE, cr); 8870 8871 /* Close layered handles */ 8872 ldi_ident_release(li); 8873 } 8874 crfree(cr); 8875 8876 sad_freespace(ss); 8877 8878 kmem_free(ss->ss_mux_nodes, sizeof (struct mux_node) * ss->ss_devcnt); 8879 ss->ss_mux_nodes = NULL; 8880 } 8881 8882 /* 8883 * Free the structure; str_stack_shutdown did the other cleanup work. 8884 */ 8885 /* ARGSUSED */ 8886 static void 8887 str_stack_fini(netstackid_t stackid, void *arg) 8888 { 8889 str_stack_t *ss = (str_stack_t *)arg; 8890 8891 kmem_free(ss, sizeof (*ss)); 8892 }