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 * Copyright (c) 2016 by Delphix. All rights reserved. 29 * Copyright 2018 OmniOS Community Edition (OmniOSce) Association. 30 * Copyright 2018 Joyent, Inc. 31 */ 32 33 #include <sys/types.h> 34 #include <sys/sysmacros.h> 35 #include <sys/param.h> 36 #include <sys/errno.h> 37 #include <sys/signal.h> 38 #include <sys/proc.h> 39 #include <sys/conf.h> 40 #include <sys/cred.h> 41 #include <sys/user.h> 42 #include <sys/vnode.h> 43 #include <sys/file.h> 44 #include <sys/session.h> 45 #include <sys/stream.h> 46 #include <sys/strsubr.h> 47 #include <sys/stropts.h> 48 #include <sys/poll.h> 49 #include <sys/systm.h> 50 #include <sys/cpuvar.h> 51 #include <sys/uio.h> 52 #include <sys/cmn_err.h> 53 #include <sys/priocntl.h> 54 #include <sys/procset.h> 55 #include <sys/vmem.h> 56 #include <sys/bitmap.h> 57 #include <sys/kmem.h> 58 #include <sys/siginfo.h> 59 #include <sys/vtrace.h> 60 #include <sys/callb.h> 61 #include <sys/debug.h> 62 #include <sys/modctl.h> 63 #include <sys/vmsystm.h> 64 #include <vm/page.h> 65 #include <sys/atomic.h> 66 #include <sys/suntpi.h> 67 #include <sys/strlog.h> 68 #include <sys/promif.h> 69 #include <sys/project.h> 70 #include <sys/vm.h> 71 #include <sys/taskq.h> 72 #include <sys/sunddi.h> 73 #include <sys/sunldi_impl.h> 74 #include <sys/strsun.h> 75 #include <sys/isa_defs.h> 76 #include <sys/multidata.h> 77 #include <sys/pattr.h> 78 #include <sys/strft.h> 79 #include <sys/fs/snode.h> 80 #include <sys/zone.h> 81 #include <sys/open.h> 82 #include <sys/sunldi.h> 83 #include <sys/sad.h> 84 #include <sys/netstack.h> 85 86 #define O_SAMESTR(q) (((q)->q_next) && \ 87 (((q)->q_flag & QREADR) == ((q)->q_next->q_flag & QREADR))) 88 89 /* 90 * WARNING: 91 * The variables and routines in this file are private, belonging 92 * to the STREAMS subsystem. These should not be used by modules 93 * or drivers. Compatibility will not be guaranteed. 94 */ 95 96 /* 97 * Id value used to distinguish between different multiplexor links. 98 */ 99 static int32_t lnk_id = 0; 100 101 #define STREAMS_LOPRI MINCLSYSPRI 102 static pri_t streams_lopri = STREAMS_LOPRI; 103 104 #define STRSTAT(x) (str_statistics.x.value.ui64++) 105 typedef struct str_stat { 106 kstat_named_t sqenables; 107 kstat_named_t stenables; 108 kstat_named_t syncqservice; 109 kstat_named_t freebs; 110 kstat_named_t qwr_outer; 111 kstat_named_t rservice; 112 kstat_named_t strwaits; 113 kstat_named_t taskqfails; 114 kstat_named_t bufcalls; 115 kstat_named_t qhelps; 116 kstat_named_t qremoved; 117 kstat_named_t sqremoved; 118 kstat_named_t bcwaits; 119 kstat_named_t sqtoomany; 120 } str_stat_t; 121 122 static str_stat_t str_statistics = { 123 { "sqenables", KSTAT_DATA_UINT64 }, 124 { "stenables", KSTAT_DATA_UINT64 }, 125 { "syncqservice", KSTAT_DATA_UINT64 }, 126 { "freebs", KSTAT_DATA_UINT64 }, 127 { "qwr_outer", KSTAT_DATA_UINT64 }, 128 { "rservice", KSTAT_DATA_UINT64 }, 129 { "strwaits", KSTAT_DATA_UINT64 }, 130 { "taskqfails", KSTAT_DATA_UINT64 }, 131 { "bufcalls", KSTAT_DATA_UINT64 }, 132 { "qhelps", KSTAT_DATA_UINT64 }, 133 { "qremoved", KSTAT_DATA_UINT64 }, 134 { "sqremoved", KSTAT_DATA_UINT64 }, 135 { "bcwaits", KSTAT_DATA_UINT64 }, 136 { "sqtoomany", KSTAT_DATA_UINT64 }, 137 }; 138 139 static kstat_t *str_kstat; 140 141 /* 142 * qrunflag was used previously to control background scheduling of queues. It 143 * is not used anymore, but kept here in case some module still wants to access 144 * it via qready() and setqsched macros. 145 */ 146 char qrunflag; /* Unused */ 147 148 /* 149 * Most of the streams scheduling is done via task queues. Task queues may fail 150 * for non-sleep dispatches, so there are two backup threads servicing failed 151 * requests for queues and syncqs. Both of these threads also service failed 152 * dispatches freebs requests. Queues are put in the list specified by `qhead' 153 * and `qtail' pointers, syncqs use `sqhead' and `sqtail' pointers and freebs 154 * requests are put into `freebs_list' which has no tail pointer. All three 155 * lists are protected by a single `service_queue' lock and use 156 * `services_to_run' condition variable for signaling background threads. Use of 157 * a single lock should not be a problem because it is only used under heavy 158 * loads when task queues start to fail and at that time it may be a good idea 159 * to throttle scheduling requests. 160 * 161 * NOTE: queues and syncqs should be scheduled by two separate threads because 162 * queue servicing may be blocked waiting for a syncq which may be also 163 * scheduled for background execution. This may create a deadlock when only one 164 * thread is used for both. 165 */ 166 167 static taskq_t *streams_taskq; /* Used for most STREAMS scheduling */ 168 169 static kmutex_t service_queue; /* protects all of servicing vars */ 170 static kcondvar_t services_to_run; /* wake up background service thread */ 171 static kcondvar_t syncqs_to_run; /* wake up background service thread */ 172 173 /* 174 * List of queues scheduled for background processing due to lack of resources 175 * in the task queues. Protected by service_queue lock; 176 */ 177 static struct queue *qhead; 178 static struct queue *qtail; 179 180 /* 181 * Same list for syncqs 182 */ 183 static syncq_t *sqhead; 184 static syncq_t *sqtail; 185 186 static mblk_t *freebs_list; /* list of buffers to free */ 187 188 /* 189 * Backup threads for servicing queues and syncqs 190 */ 191 kthread_t *streams_qbkgrnd_thread; 192 kthread_t *streams_sqbkgrnd_thread; 193 194 /* 195 * Bufcalls related variables. 196 */ 197 struct bclist strbcalls; /* list of waiting bufcalls */ 198 kmutex_t strbcall_lock; /* protects bufcall list (strbcalls) */ 199 kcondvar_t strbcall_cv; /* Signaling when a bufcall is added */ 200 kmutex_t bcall_monitor; /* sleep/wakeup style monitor */ 201 kcondvar_t bcall_cv; /* wait 'till executing bufcall completes */ 202 kthread_t *bc_bkgrnd_thread; /* Thread to service bufcall requests */ 203 204 kmutex_t strresources; /* protects global resources */ 205 kmutex_t muxifier; /* single-threads multiplexor creation */ 206 207 static void *str_stack_init(netstackid_t stackid, netstack_t *ns); 208 static void str_stack_shutdown(netstackid_t stackid, void *arg); 209 static void str_stack_fini(netstackid_t stackid, void *arg); 210 211 /* 212 * run_queues is no longer used, but is kept in case some 3rd party 213 * module/driver decides to use it. 214 */ 215 int run_queues = 0; 216 217 /* 218 * sq_max_size is the depth of the syncq (in number of messages) before 219 * qfill_syncq() starts QFULL'ing destination queues. As its primary 220 * consumer - IP is no longer D_MTPERMOD, but there may be other 221 * modules/drivers depend on this syncq flow control, we prefer to 222 * choose a large number as the default value. For potential 223 * performance gain, this value is tunable in /etc/system. 224 */ 225 int sq_max_size = 10000; 226 227 /* 228 * The number of ciputctrl structures per syncq and stream we create when 229 * needed. 230 */ 231 int n_ciputctrl; 232 int max_n_ciputctrl = 16; 233 /* 234 * If n_ciputctrl is < min_n_ciputctrl don't even create ciputctrl_cache. 235 */ 236 int min_n_ciputctrl = 2; 237 238 /* 239 * Per-driver/module syncqs 240 * ======================== 241 * 242 * For drivers/modules that use PERMOD or outer syncqs we keep a list of 243 * perdm structures, new entries being added (and new syncqs allocated) when 244 * setq() encounters a module/driver with a streamtab that it hasn't seen 245 * before. 246 * The reason for this mechanism is that some modules and drivers share a 247 * common streamtab and it is necessary for those modules and drivers to also 248 * share a common PERMOD syncq. 249 * 250 * perdm_list --> dm_str == streamtab_1 251 * dm_sq == syncq_1 252 * dm_ref 253 * dm_next --> dm_str == streamtab_2 254 * dm_sq == syncq_2 255 * dm_ref 256 * dm_next --> ... NULL 257 * 258 * The dm_ref field is incremented for each new driver/module that takes 259 * a reference to the perdm structure and hence shares the syncq. 260 * References are held in the fmodsw_impl_t structure for each STREAMS module 261 * or the dev_impl array (indexed by device major number) for each driver. 262 * 263 * perdm_list -> [dm_ref == 1] -> [dm_ref == 2] -> [dm_ref == 1] -> NULL 264 * ^ ^ ^ ^ 265 * | ______________/ | | 266 * | / | | 267 * dev_impl: ...|x|y|... module A module B 268 * 269 * When a module/driver is unloaded the reference count is decremented and, 270 * when it falls to zero, the perdm structure is removed from the list and 271 * the syncq is freed (see rele_dm()). 272 */ 273 perdm_t *perdm_list = NULL; 274 static krwlock_t perdm_rwlock; 275 cdevsw_impl_t *devimpl; 276 277 extern struct qinit strdata; 278 extern struct qinit stwdata; 279 280 static void runservice(queue_t *); 281 static void streams_bufcall_service(void); 282 static void streams_qbkgrnd_service(void); 283 static void streams_sqbkgrnd_service(void); 284 static syncq_t *new_syncq(void); 285 static void free_syncq(syncq_t *); 286 static void outer_insert(syncq_t *, syncq_t *); 287 static void outer_remove(syncq_t *, syncq_t *); 288 static void write_now(syncq_t *); 289 static void clr_qfull(queue_t *); 290 static void runbufcalls(void); 291 static void sqenable(syncq_t *); 292 static void sqfill_events(syncq_t *, queue_t *, mblk_t *, void (*)()); 293 static void wait_q_syncq(queue_t *); 294 static void backenable_insertedq(queue_t *); 295 296 static void queue_service(queue_t *); 297 static void stream_service(stdata_t *); 298 static void syncq_service(syncq_t *); 299 static void qwriter_outer_service(syncq_t *); 300 static void mblk_free(mblk_t *); 301 #ifdef DEBUG 302 static int qprocsareon(queue_t *); 303 #endif 304 305 static void set_nfsrv_ptr(queue_t *, queue_t *, queue_t *, queue_t *); 306 static void reset_nfsrv_ptr(queue_t *, queue_t *); 307 void set_qfull(queue_t *); 308 309 static void sq_run_events(syncq_t *); 310 static int propagate_syncq(queue_t *); 311 312 static void blocksq(syncq_t *, ushort_t, int); 313 static void unblocksq(syncq_t *, ushort_t, int); 314 static int dropsq(syncq_t *, uint16_t); 315 static void emptysq(syncq_t *); 316 static sqlist_t *sqlist_alloc(struct stdata *, int); 317 static void sqlist_free(sqlist_t *); 318 static sqlist_t *sqlist_build(queue_t *, struct stdata *, boolean_t); 319 static void sqlist_insert(sqlist_t *, syncq_t *); 320 static void sqlist_insertall(sqlist_t *, queue_t *); 321 322 static void strsetuio(stdata_t *); 323 324 struct kmem_cache *stream_head_cache; 325 struct kmem_cache *queue_cache; 326 struct kmem_cache *syncq_cache; 327 struct kmem_cache *qband_cache; 328 struct kmem_cache *linkinfo_cache; 329 struct kmem_cache *ciputctrl_cache = NULL; 330 331 static linkinfo_t *linkinfo_list; 332 333 /* Global esballoc throttling queue */ 334 static esb_queue_t system_esbq; 335 336 /* Array of esballoc throttling queues, of length esbq_nelem */ 337 static esb_queue_t *volatile system_esbq_array; 338 static int esbq_nelem; 339 static kmutex_t esbq_lock; 340 static int esbq_log2_cpus_per_q = 0; 341 342 /* Scale the system_esbq length by setting number of CPUs per queue. */ 343 uint_t esbq_cpus_per_q = 1; 344 345 /* 346 * esballoc tunable parameters. 347 */ 348 int esbq_max_qlen = 0x16; /* throttled queue length */ 349 clock_t esbq_timeout = 0x8; /* timeout to process esb queue */ 350 351 /* 352 * Routines to handle esballoc queueing. 353 */ 354 static void esballoc_process_queue(esb_queue_t *); 355 static void esballoc_enqueue_mblk(mblk_t *); 356 static void esballoc_timer(void *); 357 static void esballoc_set_timer(esb_queue_t *, clock_t); 358 static void esballoc_mblk_free(mblk_t *); 359 360 /* 361 * Qinit structure and Module_info structures 362 * for passthru read and write queues 363 */ 364 365 static int pass_rput(queue_t *, mblk_t *); 366 static int pass_wput(queue_t *, mblk_t *); 367 static queue_t *link_addpassthru(stdata_t *); 368 static void link_rempassthru(queue_t *); 369 370 struct module_info passthru_info = { 371 0, 372 "passthru", 373 0, 374 INFPSZ, 375 STRHIGH, 376 STRLOW 377 }; 378 379 struct qinit passthru_rinit = { 380 pass_rput, 381 NULL, 382 NULL, 383 NULL, 384 NULL, 385 &passthru_info, 386 NULL 387 }; 388 389 struct qinit passthru_winit = { 390 pass_wput, 391 NULL, 392 NULL, 393 NULL, 394 NULL, 395 &passthru_info, 396 NULL 397 }; 398 399 /* 400 * Verify correctness of list head/tail pointers. 401 */ 402 #define LISTCHECK(head, tail, link) { \ 403 EQUIV(head, tail); \ 404 IMPLY(tail != NULL, tail->link == NULL); \ 405 } 406 407 /* 408 * Enqueue a list element `el' in the end of a list denoted by `head' and `tail' 409 * using a `link' field. 410 */ 411 #define ENQUEUE(el, head, tail, link) { \ 412 ASSERT(el->link == NULL); \ 413 LISTCHECK(head, tail, link); \ 414 if (head == NULL) \ 415 head = el; \ 416 else \ 417 tail->link = el; \ 418 tail = el; \ 419 } 420 421 /* 422 * Dequeue the first element of the list denoted by `head' and `tail' pointers 423 * using a `link' field and put result into `el'. 424 */ 425 #define DQ(el, head, tail, link) { \ 426 LISTCHECK(head, tail, link); \ 427 el = head; \ 428 if (head != NULL) { \ 429 head = head->link; \ 430 if (head == NULL) \ 431 tail = NULL; \ 432 el->link = NULL; \ 433 } \ 434 } 435 436 /* 437 * Remove `el' from the list using `chase' and `curr' pointers and return result 438 * in `succeed'. 439 */ 440 #define RMQ(el, head, tail, link, chase, curr, succeed) { \ 441 LISTCHECK(head, tail, link); \ 442 chase = NULL; \ 443 succeed = 0; \ 444 for (curr = head; (curr != el) && (curr != NULL); curr = curr->link) \ 445 chase = curr; \ 446 if (curr != NULL) { \ 447 succeed = 1; \ 448 ASSERT(curr == el); \ 449 if (chase != NULL) \ 450 chase->link = curr->link; \ 451 else \ 452 head = curr->link; \ 453 curr->link = NULL; \ 454 if (curr == tail) \ 455 tail = chase; \ 456 } \ 457 LISTCHECK(head, tail, link); \ 458 } 459 460 /* Handling of delayed messages on the inner syncq. */ 461 462 /* 463 * DEBUG versions should use function versions (to simplify tracing) and 464 * non-DEBUG kernels should use macro versions. 465 */ 466 467 /* 468 * Put a queue on the syncq list of queues. 469 * Assumes SQLOCK held. 470 */ 471 #define SQPUT_Q(sq, qp) \ 472 { \ 473 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 474 if (!(qp->q_sqflags & Q_SQQUEUED)) { \ 475 /* The queue should not be linked anywhere */ \ 476 ASSERT((qp->q_sqprev == NULL) && (qp->q_sqnext == NULL)); \ 477 /* Head and tail may only be NULL simultaneously */ \ 478 EQUIV(sq->sq_head, sq->sq_tail); \ 479 /* Queue may be only enqueued on its syncq */ \ 480 ASSERT(sq == qp->q_syncq); \ 481 /* Check the correctness of SQ_MESSAGES flag */ \ 482 EQUIV(sq->sq_head, (sq->sq_flags & SQ_MESSAGES)); \ 483 /* Sanity check first/last elements of the list */ \ 484 IMPLY(sq->sq_head != NULL, sq->sq_head->q_sqprev == NULL);\ 485 IMPLY(sq->sq_tail != NULL, sq->sq_tail->q_sqnext == NULL);\ 486 /* \ 487 * Sanity check of priority field: empty queue should \ 488 * have zero priority \ 489 * and nqueues equal to zero. \ 490 */ \ 491 IMPLY(sq->sq_head == NULL, sq->sq_pri == 0); \ 492 /* Sanity check of sq_nqueues field */ \ 493 EQUIV(sq->sq_head, sq->sq_nqueues); \ 494 if (sq->sq_head == NULL) { \ 495 sq->sq_head = sq->sq_tail = qp; \ 496 sq->sq_flags |= SQ_MESSAGES; \ 497 } else if (qp->q_spri == 0) { \ 498 qp->q_sqprev = sq->sq_tail; \ 499 sq->sq_tail->q_sqnext = qp; \ 500 sq->sq_tail = qp; \ 501 } else { \ 502 /* \ 503 * Put this queue in priority order: higher \ 504 * priority gets closer to the head. \ 505 */ \ 506 queue_t **qpp = &sq->sq_tail; \ 507 queue_t *qnext = NULL; \ 508 \ 509 while (*qpp != NULL && qp->q_spri > (*qpp)->q_spri) { \ 510 qnext = *qpp; \ 511 qpp = &(*qpp)->q_sqprev; \ 512 } \ 513 qp->q_sqnext = qnext; \ 514 qp->q_sqprev = *qpp; \ 515 if (*qpp != NULL) { \ 516 (*qpp)->q_sqnext = qp; \ 517 } else { \ 518 sq->sq_head = qp; \ 519 sq->sq_pri = sq->sq_head->q_spri; \ 520 } \ 521 *qpp = qp; \ 522 } \ 523 qp->q_sqflags |= Q_SQQUEUED; \ 524 qp->q_sqtstamp = ddi_get_lbolt(); \ 525 sq->sq_nqueues++; \ 526 } \ 527 } 528 529 /* 530 * Remove a queue from the syncq list 531 * Assumes SQLOCK held. 532 */ 533 #define SQRM_Q(sq, qp) \ 534 { \ 535 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 536 ASSERT(qp->q_sqflags & Q_SQQUEUED); \ 537 ASSERT(sq->sq_head != NULL && sq->sq_tail != NULL); \ 538 ASSERT((sq->sq_flags & SQ_MESSAGES) != 0); \ 539 /* Check that the queue is actually in the list */ \ 540 ASSERT(qp->q_sqnext != NULL || sq->sq_tail == qp); \ 541 ASSERT(qp->q_sqprev != NULL || sq->sq_head == qp); \ 542 ASSERT(sq->sq_nqueues != 0); \ 543 if (qp->q_sqprev == NULL) { \ 544 /* First queue on list, make head q_sqnext */ \ 545 sq->sq_head = qp->q_sqnext; \ 546 } else { \ 547 /* Make prev->next == next */ \ 548 qp->q_sqprev->q_sqnext = qp->q_sqnext; \ 549 } \ 550 if (qp->q_sqnext == NULL) { \ 551 /* Last queue on list, make tail sqprev */ \ 552 sq->sq_tail = qp->q_sqprev; \ 553 } else { \ 554 /* Make next->prev == prev */ \ 555 qp->q_sqnext->q_sqprev = qp->q_sqprev; \ 556 } \ 557 /* clear out references on this queue */ \ 558 qp->q_sqprev = qp->q_sqnext = NULL; \ 559 qp->q_sqflags &= ~Q_SQQUEUED; \ 560 /* If there is nothing queued, clear SQ_MESSAGES */ \ 561 if (sq->sq_head != NULL) { \ 562 sq->sq_pri = sq->sq_head->q_spri; \ 563 } else { \ 564 sq->sq_flags &= ~SQ_MESSAGES; \ 565 sq->sq_pri = 0; \ 566 } \ 567 sq->sq_nqueues--; \ 568 ASSERT(sq->sq_head != NULL || sq->sq_evhead != NULL || \ 569 (sq->sq_flags & SQ_QUEUED) == 0); \ 570 } 571 572 /* Hide the definition from the header file. */ 573 #ifdef SQPUT_MP 574 #undef SQPUT_MP 575 #endif 576 577 /* 578 * Put a message on the queue syncq. 579 * Assumes QLOCK held. 580 */ 581 #define SQPUT_MP(qp, mp) \ 582 { \ 583 ASSERT(MUTEX_HELD(QLOCK(qp))); \ 584 ASSERT(qp->q_sqhead == NULL || \ 585 (qp->q_sqtail != NULL && \ 586 qp->q_sqtail->b_next == NULL)); \ 587 qp->q_syncqmsgs++; \ 588 ASSERT(qp->q_syncqmsgs != 0); /* Wraparound */ \ 589 if (qp->q_sqhead == NULL) { \ 590 qp->q_sqhead = qp->q_sqtail = mp; \ 591 } else { \ 592 qp->q_sqtail->b_next = mp; \ 593 qp->q_sqtail = mp; \ 594 } \ 595 ASSERT(qp->q_syncqmsgs > 0); \ 596 set_qfull(qp); \ 597 } 598 599 #define SQ_PUTCOUNT_SETFAST_LOCKED(sq) { \ 600 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 601 if ((sq)->sq_ciputctrl != NULL) { \ 602 int i; \ 603 int nlocks = (sq)->sq_nciputctrl; \ 604 ciputctrl_t *cip = (sq)->sq_ciputctrl; \ 605 ASSERT((sq)->sq_type & SQ_CIPUT); \ 606 for (i = 0; i <= nlocks; i++) { \ 607 ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ 608 cip[i].ciputctrl_count |= SQ_FASTPUT; \ 609 } \ 610 } \ 611 } 612 613 614 #define SQ_PUTCOUNT_CLRFAST_LOCKED(sq) { \ 615 ASSERT(MUTEX_HELD(SQLOCK(sq))); \ 616 if ((sq)->sq_ciputctrl != NULL) { \ 617 int i; \ 618 int nlocks = (sq)->sq_nciputctrl; \ 619 ciputctrl_t *cip = (sq)->sq_ciputctrl; \ 620 ASSERT((sq)->sq_type & SQ_CIPUT); \ 621 for (i = 0; i <= nlocks; i++) { \ 622 ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ 623 cip[i].ciputctrl_count &= ~SQ_FASTPUT; \ 624 } \ 625 } \ 626 } 627 628 /* 629 * Run service procedures for all queues in the stream head. 630 */ 631 #define STR_SERVICE(stp, q) { \ 632 ASSERT(MUTEX_HELD(&stp->sd_qlock)); \ 633 while (stp->sd_qhead != NULL) { \ 634 DQ(q, stp->sd_qhead, stp->sd_qtail, q_link); \ 635 ASSERT(stp->sd_nqueues > 0); \ 636 stp->sd_nqueues--; \ 637 ASSERT(!(q->q_flag & QINSERVICE)); \ 638 mutex_exit(&stp->sd_qlock); \ 639 queue_service(q); \ 640 mutex_enter(&stp->sd_qlock); \ 641 } \ 642 ASSERT(stp->sd_nqueues == 0); \ 643 ASSERT((stp->sd_qhead == NULL) && (stp->sd_qtail == NULL)); \ 644 } 645 646 /* 647 * Constructor/destructor routines for the stream head cache 648 */ 649 /* ARGSUSED */ 650 static int 651 stream_head_constructor(void *buf, void *cdrarg, int kmflags) 652 { 653 stdata_t *stp = buf; 654 655 mutex_init(&stp->sd_lock, NULL, MUTEX_DEFAULT, NULL); 656 mutex_init(&stp->sd_reflock, NULL, MUTEX_DEFAULT, NULL); 657 mutex_init(&stp->sd_qlock, NULL, MUTEX_DEFAULT, NULL); 658 cv_init(&stp->sd_monitor, NULL, CV_DEFAULT, NULL); 659 cv_init(&stp->sd_iocmonitor, NULL, CV_DEFAULT, NULL); 660 cv_init(&stp->sd_refmonitor, NULL, CV_DEFAULT, NULL); 661 cv_init(&stp->sd_qcv, NULL, CV_DEFAULT, NULL); 662 cv_init(&stp->sd_zcopy_wait, NULL, CV_DEFAULT, NULL); 663 stp->sd_wrq = NULL; 664 665 return (0); 666 } 667 668 /* ARGSUSED */ 669 static void 670 stream_head_destructor(void *buf, void *cdrarg) 671 { 672 stdata_t *stp = buf; 673 674 mutex_destroy(&stp->sd_lock); 675 mutex_destroy(&stp->sd_reflock); 676 mutex_destroy(&stp->sd_qlock); 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 } 683 684 /* 685 * Constructor/destructor routines for the queue cache 686 */ 687 /* ARGSUSED */ 688 static int 689 queue_constructor(void *buf, void *cdrarg, int kmflags) 690 { 691 queinfo_t *qip = buf; 692 queue_t *qp = &qip->qu_rqueue; 693 queue_t *wqp = &qip->qu_wqueue; 694 syncq_t *sq = &qip->qu_syncq; 695 696 qp->q_first = NULL; 697 qp->q_link = NULL; 698 qp->q_count = 0; 699 qp->q_mblkcnt = 0; 700 qp->q_sqhead = NULL; 701 qp->q_sqtail = NULL; 702 qp->q_sqnext = NULL; 703 qp->q_sqprev = NULL; 704 qp->q_sqflags = 0; 705 qp->q_rwcnt = 0; 706 qp->q_spri = 0; 707 708 mutex_init(QLOCK(qp), NULL, MUTEX_DEFAULT, NULL); 709 cv_init(&qp->q_wait, NULL, CV_DEFAULT, NULL); 710 711 wqp->q_first = NULL; 712 wqp->q_link = NULL; 713 wqp->q_count = 0; 714 wqp->q_mblkcnt = 0; 715 wqp->q_sqhead = NULL; 716 wqp->q_sqtail = NULL; 717 wqp->q_sqnext = NULL; 718 wqp->q_sqprev = NULL; 719 wqp->q_sqflags = 0; 720 wqp->q_rwcnt = 0; 721 wqp->q_spri = 0; 722 723 mutex_init(QLOCK(wqp), NULL, MUTEX_DEFAULT, NULL); 724 cv_init(&wqp->q_wait, NULL, CV_DEFAULT, NULL); 725 726 sq->sq_head = NULL; 727 sq->sq_tail = NULL; 728 sq->sq_evhead = NULL; 729 sq->sq_evtail = NULL; 730 sq->sq_callbpend = NULL; 731 sq->sq_outer = NULL; 732 sq->sq_onext = NULL; 733 sq->sq_oprev = NULL; 734 sq->sq_next = NULL; 735 sq->sq_svcflags = 0; 736 sq->sq_servcount = 0; 737 sq->sq_needexcl = 0; 738 sq->sq_nqueues = 0; 739 sq->sq_pri = 0; 740 741 mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); 742 cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); 743 cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); 744 745 return (0); 746 } 747 748 /* ARGSUSED */ 749 static void 750 queue_destructor(void *buf, void *cdrarg) 751 { 752 queinfo_t *qip = buf; 753 queue_t *qp = &qip->qu_rqueue; 754 queue_t *wqp = &qip->qu_wqueue; 755 syncq_t *sq = &qip->qu_syncq; 756 757 ASSERT(qp->q_sqhead == NULL); 758 ASSERT(wqp->q_sqhead == NULL); 759 ASSERT(qp->q_sqnext == NULL); 760 ASSERT(wqp->q_sqnext == NULL); 761 ASSERT(qp->q_rwcnt == 0); 762 ASSERT(wqp->q_rwcnt == 0); 763 764 mutex_destroy(&qp->q_lock); 765 cv_destroy(&qp->q_wait); 766 767 mutex_destroy(&wqp->q_lock); 768 cv_destroy(&wqp->q_wait); 769 770 mutex_destroy(&sq->sq_lock); 771 cv_destroy(&sq->sq_wait); 772 cv_destroy(&sq->sq_exitwait); 773 } 774 775 /* 776 * Constructor/destructor routines for the syncq cache 777 */ 778 /* ARGSUSED */ 779 static int 780 syncq_constructor(void *buf, void *cdrarg, int kmflags) 781 { 782 syncq_t *sq = buf; 783 784 bzero(buf, sizeof (syncq_t)); 785 786 mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); 787 cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); 788 cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); 789 790 return (0); 791 } 792 793 /* ARGSUSED */ 794 static void 795 syncq_destructor(void *buf, void *cdrarg) 796 { 797 syncq_t *sq = buf; 798 799 ASSERT(sq->sq_head == NULL); 800 ASSERT(sq->sq_tail == NULL); 801 ASSERT(sq->sq_evhead == NULL); 802 ASSERT(sq->sq_evtail == NULL); 803 ASSERT(sq->sq_callbpend == NULL); 804 ASSERT(sq->sq_callbflags == 0); 805 ASSERT(sq->sq_outer == NULL); 806 ASSERT(sq->sq_onext == NULL); 807 ASSERT(sq->sq_oprev == NULL); 808 ASSERT(sq->sq_next == NULL); 809 ASSERT(sq->sq_needexcl == 0); 810 ASSERT(sq->sq_svcflags == 0); 811 ASSERT(sq->sq_servcount == 0); 812 ASSERT(sq->sq_nqueues == 0); 813 ASSERT(sq->sq_pri == 0); 814 ASSERT(sq->sq_count == 0); 815 ASSERT(sq->sq_rmqcount == 0); 816 ASSERT(sq->sq_cancelid == 0); 817 ASSERT(sq->sq_ciputctrl == NULL); 818 ASSERT(sq->sq_nciputctrl == 0); 819 ASSERT(sq->sq_type == 0); 820 ASSERT(sq->sq_flags == 0); 821 822 mutex_destroy(&sq->sq_lock); 823 cv_destroy(&sq->sq_wait); 824 cv_destroy(&sq->sq_exitwait); 825 } 826 827 /* ARGSUSED */ 828 static int 829 ciputctrl_constructor(void *buf, void *cdrarg, int kmflags) 830 { 831 ciputctrl_t *cip = buf; 832 int i; 833 834 for (i = 0; i < n_ciputctrl; i++) { 835 cip[i].ciputctrl_count = SQ_FASTPUT; 836 mutex_init(&cip[i].ciputctrl_lock, NULL, MUTEX_DEFAULT, NULL); 837 } 838 839 return (0); 840 } 841 842 /* ARGSUSED */ 843 static void 844 ciputctrl_destructor(void *buf, void *cdrarg) 845 { 846 ciputctrl_t *cip = buf; 847 int i; 848 849 for (i = 0; i < n_ciputctrl; i++) { 850 ASSERT(cip[i].ciputctrl_count & SQ_FASTPUT); 851 mutex_destroy(&cip[i].ciputctrl_lock); 852 } 853 } 854 855 /* 856 * Init routine run from main at boot time. 857 */ 858 void 859 strinit(void) 860 { 861 int ncpus = ((boot_max_ncpus == -1) ? max_ncpus : boot_max_ncpus); 862 863 stream_head_cache = kmem_cache_create("stream_head_cache", 864 sizeof (stdata_t), 0, 865 stream_head_constructor, stream_head_destructor, NULL, 866 NULL, NULL, 0); 867 868 queue_cache = kmem_cache_create("queue_cache", sizeof (queinfo_t), 0, 869 queue_constructor, queue_destructor, NULL, NULL, NULL, 0); 870 871 syncq_cache = kmem_cache_create("syncq_cache", sizeof (syncq_t), 0, 872 syncq_constructor, syncq_destructor, NULL, NULL, NULL, 0); 873 874 qband_cache = kmem_cache_create("qband_cache", 875 sizeof (qband_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 876 877 linkinfo_cache = kmem_cache_create("linkinfo_cache", 878 sizeof (linkinfo_t), 0, NULL, NULL, NULL, NULL, NULL, 0); 879 880 n_ciputctrl = ncpus; 881 n_ciputctrl = 1 << highbit(n_ciputctrl - 1); 882 ASSERT(n_ciputctrl >= 1); 883 n_ciputctrl = MIN(n_ciputctrl, max_n_ciputctrl); 884 if (n_ciputctrl >= min_n_ciputctrl) { 885 ciputctrl_cache = kmem_cache_create("ciputctrl_cache", 886 sizeof (ciputctrl_t) * n_ciputctrl, 887 sizeof (ciputctrl_t), ciputctrl_constructor, 888 ciputctrl_destructor, NULL, NULL, NULL, 0); 889 } 890 891 streams_taskq = system_taskq; 892 893 if (streams_taskq == NULL) 894 panic("strinit: no memory for streams taskq!"); 895 896 bc_bkgrnd_thread = thread_create(NULL, 0, 897 streams_bufcall_service, NULL, 0, &p0, TS_RUN, streams_lopri); 898 899 streams_qbkgrnd_thread = thread_create(NULL, 0, 900 streams_qbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); 901 902 streams_sqbkgrnd_thread = thread_create(NULL, 0, 903 streams_sqbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); 904 905 /* 906 * Create STREAMS kstats. 907 */ 908 str_kstat = kstat_create("streams", 0, "strstat", 909 "net", KSTAT_TYPE_NAMED, 910 sizeof (str_statistics) / sizeof (kstat_named_t), 911 KSTAT_FLAG_VIRTUAL); 912 913 if (str_kstat != NULL) { 914 str_kstat->ks_data = &str_statistics; 915 kstat_install(str_kstat); 916 } 917 918 /* 919 * TPI support routine initialisation. 920 */ 921 tpi_init(); 922 923 /* 924 * Handle to have autopush and persistent link information per 925 * zone. 926 * Note: uses shutdown hook instead of destroy hook so that the 927 * persistent links can be torn down before the destroy hooks 928 * in the TCP/IP stack are called. 929 */ 930 netstack_register(NS_STR, str_stack_init, str_stack_shutdown, 931 str_stack_fini); 932 } 933 934 void 935 str_sendsig(vnode_t *vp, int event, uchar_t band, int error) 936 { 937 struct stdata *stp; 938 939 ASSERT(vp->v_stream); 940 stp = vp->v_stream; 941 /* Have to hold sd_lock to prevent siglist from changing */ 942 mutex_enter(&stp->sd_lock); 943 if (stp->sd_sigflags & event) 944 strsendsig(stp->sd_siglist, event, band, error); 945 mutex_exit(&stp->sd_lock); 946 } 947 948 /* 949 * Send the "sevent" set of signals to a process. 950 * This might send more than one signal if the process is registered 951 * for multiple events. The caller should pass in an sevent that only 952 * includes the events for which the process has registered. 953 */ 954 static void 955 dosendsig(proc_t *proc, int events, int sevent, k_siginfo_t *info, 956 uchar_t band, int error) 957 { 958 ASSERT(MUTEX_HELD(&proc->p_lock)); 959 960 info->si_band = 0; 961 info->si_errno = 0; 962 963 if (sevent & S_ERROR) { 964 sevent &= ~S_ERROR; 965 info->si_code = POLL_ERR; 966 info->si_errno = error; 967 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 968 "strsendsig:proc %p info %p", proc, info); 969 sigaddq(proc, NULL, info, KM_NOSLEEP); 970 info->si_errno = 0; 971 } 972 if (sevent & S_HANGUP) { 973 sevent &= ~S_HANGUP; 974 info->si_code = POLL_HUP; 975 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 976 "strsendsig:proc %p info %p", proc, info); 977 sigaddq(proc, NULL, info, KM_NOSLEEP); 978 } 979 if (sevent & S_HIPRI) { 980 sevent &= ~S_HIPRI; 981 info->si_code = POLL_PRI; 982 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 983 "strsendsig:proc %p info %p", proc, info); 984 sigaddq(proc, NULL, info, KM_NOSLEEP); 985 } 986 if (sevent & S_RDBAND) { 987 sevent &= ~S_RDBAND; 988 if (events & S_BANDURG) 989 sigtoproc(proc, NULL, SIGURG); 990 else 991 sigtoproc(proc, NULL, SIGPOLL); 992 } 993 if (sevent & S_WRBAND) { 994 sevent &= ~S_WRBAND; 995 sigtoproc(proc, NULL, SIGPOLL); 996 } 997 if (sevent & S_INPUT) { 998 sevent &= ~S_INPUT; 999 info->si_code = POLL_IN; 1000 info->si_band = band; 1001 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1002 "strsendsig:proc %p info %p", proc, info); 1003 sigaddq(proc, NULL, info, KM_NOSLEEP); 1004 info->si_band = 0; 1005 } 1006 if (sevent & S_OUTPUT) { 1007 sevent &= ~S_OUTPUT; 1008 info->si_code = POLL_OUT; 1009 info->si_band = band; 1010 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1011 "strsendsig:proc %p info %p", proc, info); 1012 sigaddq(proc, NULL, info, KM_NOSLEEP); 1013 info->si_band = 0; 1014 } 1015 if (sevent & S_MSG) { 1016 sevent &= ~S_MSG; 1017 info->si_code = POLL_MSG; 1018 info->si_band = band; 1019 TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, 1020 "strsendsig:proc %p info %p", proc, info); 1021 sigaddq(proc, NULL, info, KM_NOSLEEP); 1022 info->si_band = 0; 1023 } 1024 if (sevent & S_RDNORM) { 1025 sevent &= ~S_RDNORM; 1026 sigtoproc(proc, NULL, SIGPOLL); 1027 } 1028 if (sevent != 0) { 1029 panic("strsendsig: unknown event(s) %x", sevent); 1030 } 1031 } 1032 1033 /* 1034 * Send SIGPOLL/SIGURG signal to all processes and process groups 1035 * registered on the given signal list that want a signal for at 1036 * least one of the specified events. 1037 * 1038 * Must be called with exclusive access to siglist (caller holding sd_lock). 1039 * 1040 * strioctl(I_SETSIG/I_ESETSIG) will only change siglist when holding 1041 * sd_lock and the ioctl code maintains a PID_HOLD on the pid structure 1042 * while it is in the siglist. 1043 * 1044 * For performance reasons (MP scalability) the code drops pidlock 1045 * when sending signals to a single process. 1046 * When sending to a process group the code holds 1047 * pidlock to prevent the membership in the process group from changing 1048 * while walking the p_pglink list. 1049 */ 1050 void 1051 strsendsig(strsig_t *siglist, int event, uchar_t band, int error) 1052 { 1053 strsig_t *ssp; 1054 k_siginfo_t info; 1055 struct pid *pidp; 1056 proc_t *proc; 1057 1058 info.si_signo = SIGPOLL; 1059 info.si_errno = 0; 1060 for (ssp = siglist; ssp; ssp = ssp->ss_next) { 1061 int sevent; 1062 1063 sevent = ssp->ss_events & event; 1064 if (sevent == 0) 1065 continue; 1066 1067 if ((pidp = ssp->ss_pidp) == NULL) { 1068 /* pid was released but still on event list */ 1069 continue; 1070 } 1071 1072 1073 if (ssp->ss_pid > 0) { 1074 /* 1075 * XXX This unfortunately still generates 1076 * a signal when a fd is closed but 1077 * the proc is active. 1078 */ 1079 ASSERT(ssp->ss_pid == pidp->pid_id); 1080 1081 mutex_enter(&pidlock); 1082 proc = prfind_zone(pidp->pid_id, ALL_ZONES); 1083 if (proc == NULL) { 1084 mutex_exit(&pidlock); 1085 continue; 1086 } 1087 mutex_enter(&proc->p_lock); 1088 mutex_exit(&pidlock); 1089 dosendsig(proc, ssp->ss_events, sevent, &info, 1090 band, error); 1091 mutex_exit(&proc->p_lock); 1092 } else { 1093 /* 1094 * Send to process group. Hold pidlock across 1095 * calls to dosendsig(). 1096 */ 1097 pid_t pgrp = -ssp->ss_pid; 1098 1099 mutex_enter(&pidlock); 1100 proc = pgfind_zone(pgrp, ALL_ZONES); 1101 while (proc != NULL) { 1102 mutex_enter(&proc->p_lock); 1103 dosendsig(proc, ssp->ss_events, sevent, 1104 &info, band, error); 1105 mutex_exit(&proc->p_lock); 1106 proc = proc->p_pglink; 1107 } 1108 mutex_exit(&pidlock); 1109 } 1110 } 1111 } 1112 1113 /* 1114 * Attach a stream device or module. 1115 * qp is a read queue; the new queue goes in so its next 1116 * read ptr is the argument, and the write queue corresponding 1117 * to the argument points to this queue. Return 0 on success, 1118 * or a non-zero errno on failure. 1119 */ 1120 int 1121 qattach(queue_t *qp, dev_t *devp, int oflag, cred_t *crp, fmodsw_impl_t *fp, 1122 boolean_t is_insert) 1123 { 1124 major_t major; 1125 cdevsw_impl_t *dp; 1126 struct streamtab *str; 1127 queue_t *rq; 1128 queue_t *wrq; 1129 uint32_t qflag; 1130 uint32_t sqtype; 1131 perdm_t *dmp; 1132 int error; 1133 int sflag; 1134 1135 rq = allocq(); 1136 wrq = _WR(rq); 1137 STREAM(rq) = STREAM(wrq) = STREAM(qp); 1138 1139 if (fp != NULL) { 1140 str = fp->f_str; 1141 qflag = fp->f_qflag; 1142 sqtype = fp->f_sqtype; 1143 dmp = fp->f_dmp; 1144 IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); 1145 sflag = MODOPEN; 1146 1147 /* 1148 * stash away a pointer to the module structure so we can 1149 * unref it in qdetach. 1150 */ 1151 rq->q_fp = fp; 1152 } else { 1153 ASSERT(!is_insert); 1154 1155 major = getmajor(*devp); 1156 dp = &devimpl[major]; 1157 1158 str = dp->d_str; 1159 ASSERT(str == STREAMSTAB(major)); 1160 1161 qflag = dp->d_qflag; 1162 ASSERT(qflag & QISDRV); 1163 sqtype = dp->d_sqtype; 1164 1165 /* create perdm_t if needed */ 1166 if (NEED_DM(dp->d_dmp, qflag)) 1167 dp->d_dmp = hold_dm(str, qflag, sqtype); 1168 1169 dmp = dp->d_dmp; 1170 sflag = 0; 1171 } 1172 1173 TRACE_2(TR_FAC_STREAMS_FR, TR_QATTACH_FLAGS, 1174 "qattach:qflag == %X(%X)", qflag, *devp); 1175 1176 /* setq might sleep in allocator - avoid holding locks. */ 1177 setq(rq, str->st_rdinit, str->st_wrinit, dmp, qflag, sqtype, B_FALSE); 1178 1179 /* 1180 * Before calling the module's open routine, set up the q_next 1181 * pointer for inserting a module in the middle of a stream. 1182 * 1183 * Note that we can always set _QINSERTING and set up q_next 1184 * pointer for both inserting and pushing a module. Then there 1185 * is no need for the is_insert parameter. In insertq(), called 1186 * by qprocson(), assume that q_next of the new module always points 1187 * to the correct queue and use it for insertion. Everything should 1188 * work out fine. But in the first release of _I_INSERT, we 1189 * distinguish between inserting and pushing to make sure that 1190 * pushing a module follows the same code path as before. 1191 */ 1192 if (is_insert) { 1193 rq->q_flag |= _QINSERTING; 1194 rq->q_next = qp; 1195 } 1196 1197 /* 1198 * If there is an outer perimeter get exclusive access during 1199 * the open procedure. Bump up the reference count on the queue. 1200 */ 1201 entersq(rq->q_syncq, SQ_OPENCLOSE); 1202 error = (*rq->q_qinfo->qi_qopen)(rq, devp, oflag, sflag, crp); 1203 if (error != 0) 1204 goto failed; 1205 leavesq(rq->q_syncq, SQ_OPENCLOSE); 1206 ASSERT(qprocsareon(rq)); 1207 return (0); 1208 1209 failed: 1210 rq->q_flag &= ~_QINSERTING; 1211 if (backq(wrq) != NULL && backq(wrq)->q_next == wrq) 1212 qprocsoff(rq); 1213 leavesq(rq->q_syncq, SQ_OPENCLOSE); 1214 rq->q_next = wrq->q_next = NULL; 1215 qdetach(rq, 0, 0, crp, B_FALSE); 1216 return (error); 1217 } 1218 1219 /* 1220 * Handle second open of stream. For modules, set the 1221 * last argument to MODOPEN and do not pass any open flags. 1222 * Ignore dummydev since this is not the first open. 1223 */ 1224 int 1225 qreopen(queue_t *qp, dev_t *devp, int flag, cred_t *crp) 1226 { 1227 int error; 1228 dev_t dummydev; 1229 queue_t *wqp = _WR(qp); 1230 1231 ASSERT(qp->q_flag & QREADR); 1232 entersq(qp->q_syncq, SQ_OPENCLOSE); 1233 1234 dummydev = *devp; 1235 if (error = ((*qp->q_qinfo->qi_qopen)(qp, &dummydev, 1236 (wqp->q_next ? 0 : flag), (wqp->q_next ? MODOPEN : 0), crp))) { 1237 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1238 mutex_enter(&STREAM(qp)->sd_lock); 1239 qp->q_stream->sd_flag |= STREOPENFAIL; 1240 mutex_exit(&STREAM(qp)->sd_lock); 1241 return (error); 1242 } 1243 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1244 1245 /* 1246 * successful open should have done qprocson() 1247 */ 1248 ASSERT(qprocsareon(_RD(qp))); 1249 return (0); 1250 } 1251 1252 /* 1253 * Detach a stream module or device. 1254 * If clmode == 1 then the module or driver was opened and its 1255 * close routine must be called. If clmode == 0, the module 1256 * or driver was never opened or the open failed, and so its close 1257 * should not be called. 1258 */ 1259 void 1260 qdetach(queue_t *qp, int clmode, int flag, cred_t *crp, boolean_t is_remove) 1261 { 1262 queue_t *wqp = _WR(qp); 1263 ASSERT(STREAM(qp)->sd_flag & (STRCLOSE|STWOPEN|STRPLUMB)); 1264 1265 if (STREAM_NEEDSERVICE(STREAM(qp))) 1266 stream_runservice(STREAM(qp)); 1267 1268 if (clmode) { 1269 /* 1270 * Make sure that all the messages on the write side syncq are 1271 * processed and nothing is left. Since we are closing, no new 1272 * messages may appear there. 1273 */ 1274 wait_q_syncq(wqp); 1275 1276 entersq(qp->q_syncq, SQ_OPENCLOSE); 1277 if (is_remove) { 1278 mutex_enter(QLOCK(qp)); 1279 qp->q_flag |= _QREMOVING; 1280 mutex_exit(QLOCK(qp)); 1281 } 1282 (*qp->q_qinfo->qi_qclose)(qp, flag, crp); 1283 /* 1284 * Check that qprocsoff() was actually called. 1285 */ 1286 ASSERT((qp->q_flag & QWCLOSE) && (wqp->q_flag & QWCLOSE)); 1287 1288 leavesq(qp->q_syncq, SQ_OPENCLOSE); 1289 } else { 1290 disable_svc(qp); 1291 } 1292 1293 /* 1294 * Allow any threads blocked in entersq to proceed and discover 1295 * the QWCLOSE is set. 1296 * Note: This assumes that all users of entersq check QWCLOSE. 1297 * Currently runservice is the only entersq that can happen 1298 * after removeq has finished. 1299 * Removeq will have discarded all messages destined to the closing 1300 * pair of queues from the syncq. 1301 * NOTE: Calling a function inside an assert is unconventional. 1302 * However, it does not cause any problem since flush_syncq() does 1303 * not change any state except when it returns non-zero i.e. 1304 * when the assert will trigger. 1305 */ 1306 ASSERT(flush_syncq(qp->q_syncq, qp) == 0); 1307 ASSERT(flush_syncq(wqp->q_syncq, wqp) == 0); 1308 ASSERT((qp->q_flag & QPERMOD) || 1309 ((qp->q_syncq->sq_head == NULL) && 1310 (wqp->q_syncq->sq_head == NULL))); 1311 1312 /* release any fmodsw_impl_t structure held on behalf of the queue */ 1313 ASSERT(qp->q_fp != NULL || qp->q_flag & QISDRV); 1314 if (qp->q_fp != NULL) 1315 fmodsw_rele(qp->q_fp); 1316 1317 /* freeq removes us from the outer perimeter if any */ 1318 freeq(qp); 1319 } 1320 1321 /* Prevent service procedures from being called */ 1322 void 1323 disable_svc(queue_t *qp) 1324 { 1325 queue_t *wqp = _WR(qp); 1326 1327 ASSERT(qp->q_flag & QREADR); 1328 mutex_enter(QLOCK(qp)); 1329 qp->q_flag |= QWCLOSE; 1330 mutex_exit(QLOCK(qp)); 1331 mutex_enter(QLOCK(wqp)); 1332 wqp->q_flag |= QWCLOSE; 1333 mutex_exit(QLOCK(wqp)); 1334 } 1335 1336 /* Allow service procedures to be called again */ 1337 void 1338 enable_svc(queue_t *qp) 1339 { 1340 queue_t *wqp = _WR(qp); 1341 1342 ASSERT(qp->q_flag & QREADR); 1343 mutex_enter(QLOCK(qp)); 1344 qp->q_flag &= ~QWCLOSE; 1345 mutex_exit(QLOCK(qp)); 1346 mutex_enter(QLOCK(wqp)); 1347 wqp->q_flag &= ~QWCLOSE; 1348 mutex_exit(QLOCK(wqp)); 1349 } 1350 1351 /* 1352 * Remove queue from qhead/qtail if it is enabled. 1353 * Only reset QENAB if the queue was removed from the runlist. 1354 * A queue goes through 3 stages: 1355 * It is on the service list and QENAB is set. 1356 * It is removed from the service list but QENAB is still set. 1357 * QENAB gets changed to QINSERVICE. 1358 * QINSERVICE is reset (when the service procedure is done) 1359 * Thus we can not reset QENAB unless we actually removed it from the service 1360 * queue. 1361 */ 1362 void 1363 remove_runlist(queue_t *qp) 1364 { 1365 if (qp->q_flag & QENAB && qhead != NULL) { 1366 queue_t *q_chase; 1367 queue_t *q_curr; 1368 int removed; 1369 1370 mutex_enter(&service_queue); 1371 RMQ(qp, qhead, qtail, q_link, q_chase, q_curr, removed); 1372 mutex_exit(&service_queue); 1373 if (removed) { 1374 STRSTAT(qremoved); 1375 qp->q_flag &= ~QENAB; 1376 } 1377 } 1378 } 1379 1380 1381 /* 1382 * Wait for any pending service processing to complete. 1383 * The removal of queues from the runlist is not atomic with the 1384 * clearing of the QENABLED flag and setting the INSERVICE flag. 1385 * consequently it is possible for remove_runlist in strclose 1386 * to not find the queue on the runlist but for it to be QENABLED 1387 * and not yet INSERVICE -> hence wait_svc needs to check QENABLED 1388 * as well as INSERVICE. 1389 */ 1390 void 1391 wait_svc(queue_t *qp) 1392 { 1393 queue_t *wqp = _WR(qp); 1394 1395 ASSERT(qp->q_flag & QREADR); 1396 1397 /* 1398 * Try to remove queues from qhead/qtail list. 1399 */ 1400 if (qhead != NULL) { 1401 remove_runlist(qp); 1402 remove_runlist(wqp); 1403 } 1404 /* 1405 * Wait till the syncqs associated with the queue disappear from the 1406 * background processing list. 1407 * This only needs to be done for non-PERMOD perimeters since 1408 * for PERMOD perimeters the syncq may be shared and will only be freed 1409 * when the last module/driver is unloaded. 1410 * If for PERMOD perimeters queue was on the syncq list, removeq() 1411 * should call propagate_syncq() or drain_syncq() for it. Both of these 1412 * functions remove the queue from its syncq list, so sqthread will not 1413 * try to access the queue. 1414 */ 1415 if (!(qp->q_flag & QPERMOD)) { 1416 syncq_t *rsq = qp->q_syncq; 1417 syncq_t *wsq = wqp->q_syncq; 1418 1419 /* 1420 * Disable rsq and wsq and wait for any background processing of 1421 * syncq to complete. 1422 */ 1423 wait_sq_svc(rsq); 1424 if (wsq != rsq) 1425 wait_sq_svc(wsq); 1426 } 1427 1428 mutex_enter(QLOCK(qp)); 1429 while (qp->q_flag & (QINSERVICE|QENAB)) 1430 cv_wait(&qp->q_wait, QLOCK(qp)); 1431 mutex_exit(QLOCK(qp)); 1432 mutex_enter(QLOCK(wqp)); 1433 while (wqp->q_flag & (QINSERVICE|QENAB)) 1434 cv_wait(&wqp->q_wait, QLOCK(wqp)); 1435 mutex_exit(QLOCK(wqp)); 1436 } 1437 1438 /* 1439 * Put ioctl data from userland buffer `arg' into the mblk chain `bp'. 1440 * `flag' must always contain either K_TO_K or U_TO_K; STR_NOSIG may 1441 * also be set, and is passed through to allocb_cred_wait(). 1442 * 1443 * Returns errno on failure, zero on success. 1444 */ 1445 int 1446 putiocd(mblk_t *bp, char *arg, int flag, cred_t *cr) 1447 { 1448 mblk_t *tmp; 1449 ssize_t count; 1450 int error = 0; 1451 1452 ASSERT((flag & (U_TO_K | K_TO_K)) == U_TO_K || 1453 (flag & (U_TO_K | K_TO_K)) == K_TO_K); 1454 1455 if (bp->b_datap->db_type == M_IOCTL) { 1456 count = ((struct iocblk *)bp->b_rptr)->ioc_count; 1457 } else { 1458 ASSERT(bp->b_datap->db_type == M_COPYIN); 1459 count = ((struct copyreq *)bp->b_rptr)->cq_size; 1460 } 1461 /* 1462 * strdoioctl validates ioc_count, so if this assert fails it 1463 * cannot be due to user error. 1464 */ 1465 ASSERT(count >= 0); 1466 1467 if ((tmp = allocb_cred_wait(count, (flag & STR_NOSIG), &error, cr, 1468 curproc->p_pid)) == NULL) { 1469 return (error); 1470 } 1471 error = strcopyin(arg, tmp->b_wptr, count, flag & (U_TO_K|K_TO_K)); 1472 if (error != 0) { 1473 freeb(tmp); 1474 return (error); 1475 } 1476 DB_CPID(tmp) = curproc->p_pid; 1477 tmp->b_wptr += count; 1478 bp->b_cont = tmp; 1479 1480 return (0); 1481 } 1482 1483 /* 1484 * Copy ioctl data to user-land. Return non-zero errno on failure, 1485 * 0 for success. 1486 */ 1487 int 1488 getiocd(mblk_t *bp, char *arg, int copymode) 1489 { 1490 ssize_t count; 1491 size_t n; 1492 int error; 1493 1494 if (bp->b_datap->db_type == M_IOCACK) 1495 count = ((struct iocblk *)bp->b_rptr)->ioc_count; 1496 else { 1497 ASSERT(bp->b_datap->db_type == M_COPYOUT); 1498 count = ((struct copyreq *)bp->b_rptr)->cq_size; 1499 } 1500 ASSERT(count >= 0); 1501 1502 for (bp = bp->b_cont; bp && count; 1503 count -= n, bp = bp->b_cont, arg += n) { 1504 n = MIN(count, bp->b_wptr - bp->b_rptr); 1505 error = strcopyout(bp->b_rptr, arg, n, copymode); 1506 if (error) 1507 return (error); 1508 } 1509 ASSERT(count == 0); 1510 return (0); 1511 } 1512 1513 /* 1514 * Allocate a linkinfo entry given the write queue of the 1515 * bottom module of the top stream and the write queue of the 1516 * stream head of the bottom stream. 1517 */ 1518 linkinfo_t * 1519 alloclink(queue_t *qup, queue_t *qdown, file_t *fpdown) 1520 { 1521 linkinfo_t *linkp; 1522 1523 linkp = kmem_cache_alloc(linkinfo_cache, KM_SLEEP); 1524 1525 linkp->li_lblk.l_qtop = qup; 1526 linkp->li_lblk.l_qbot = qdown; 1527 linkp->li_fpdown = fpdown; 1528 1529 mutex_enter(&strresources); 1530 linkp->li_next = linkinfo_list; 1531 linkp->li_prev = NULL; 1532 if (linkp->li_next) 1533 linkp->li_next->li_prev = linkp; 1534 linkinfo_list = linkp; 1535 linkp->li_lblk.l_index = ++lnk_id; 1536 ASSERT(lnk_id != 0); /* this should never wrap in practice */ 1537 mutex_exit(&strresources); 1538 1539 return (linkp); 1540 } 1541 1542 /* 1543 * Free a linkinfo entry. 1544 */ 1545 void 1546 lbfree(linkinfo_t *linkp) 1547 { 1548 mutex_enter(&strresources); 1549 if (linkp->li_next) 1550 linkp->li_next->li_prev = linkp->li_prev; 1551 if (linkp->li_prev) 1552 linkp->li_prev->li_next = linkp->li_next; 1553 else 1554 linkinfo_list = linkp->li_next; 1555 mutex_exit(&strresources); 1556 1557 kmem_cache_free(linkinfo_cache, linkp); 1558 } 1559 1560 /* 1561 * Check for a potential linking cycle. 1562 * Return 1 if a link will result in a cycle, 1563 * and 0 otherwise. 1564 */ 1565 int 1566 linkcycle(stdata_t *upstp, stdata_t *lostp, str_stack_t *ss) 1567 { 1568 struct mux_node *np; 1569 struct mux_edge *ep; 1570 int i; 1571 major_t lomaj; 1572 major_t upmaj; 1573 /* 1574 * if the lower stream is a pipe/FIFO, return, since link 1575 * cycles can not happen on pipes/FIFOs 1576 */ 1577 if (lostp->sd_vnode->v_type == VFIFO) 1578 return (0); 1579 1580 for (i = 0; i < ss->ss_devcnt; i++) { 1581 np = &ss->ss_mux_nodes[i]; 1582 MUX_CLEAR(np); 1583 } 1584 lomaj = getmajor(lostp->sd_vnode->v_rdev); 1585 upmaj = getmajor(upstp->sd_vnode->v_rdev); 1586 np = &ss->ss_mux_nodes[lomaj]; 1587 for (;;) { 1588 if (!MUX_DIDVISIT(np)) { 1589 if (np->mn_imaj == upmaj) 1590 return (1); 1591 if (np->mn_outp == NULL) { 1592 MUX_VISIT(np); 1593 if (np->mn_originp == NULL) 1594 return (0); 1595 np = np->mn_originp; 1596 continue; 1597 } 1598 MUX_VISIT(np); 1599 np->mn_startp = np->mn_outp; 1600 } else { 1601 if (np->mn_startp == NULL) { 1602 if (np->mn_originp == NULL) 1603 return (0); 1604 else { 1605 np = np->mn_originp; 1606 continue; 1607 } 1608 } 1609 /* 1610 * If ep->me_nodep is a FIFO (me_nodep == NULL), 1611 * ignore the edge and move on. ep->me_nodep gets 1612 * set to NULL in mux_addedge() if it is a FIFO. 1613 * 1614 */ 1615 ep = np->mn_startp; 1616 np->mn_startp = ep->me_nextp; 1617 if (ep->me_nodep == NULL) 1618 continue; 1619 ep->me_nodep->mn_originp = np; 1620 np = ep->me_nodep; 1621 } 1622 } 1623 } 1624 1625 /* 1626 * Find linkinfo entry corresponding to the parameters. 1627 */ 1628 linkinfo_t * 1629 findlinks(stdata_t *stp, int index, int type, str_stack_t *ss) 1630 { 1631 linkinfo_t *linkp; 1632 struct mux_edge *mep; 1633 struct mux_node *mnp; 1634 queue_t *qup; 1635 1636 mutex_enter(&strresources); 1637 if ((type & LINKTYPEMASK) == LINKNORMAL) { 1638 qup = getendq(stp->sd_wrq); 1639 for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { 1640 if ((qup == linkp->li_lblk.l_qtop) && 1641 (!index || (index == linkp->li_lblk.l_index))) { 1642 mutex_exit(&strresources); 1643 return (linkp); 1644 } 1645 } 1646 } else { 1647 ASSERT((type & LINKTYPEMASK) == LINKPERSIST); 1648 mnp = &ss->ss_mux_nodes[getmajor(stp->sd_vnode->v_rdev)]; 1649 mep = mnp->mn_outp; 1650 while (mep) { 1651 if ((index == 0) || (index == mep->me_muxid)) 1652 break; 1653 mep = mep->me_nextp; 1654 } 1655 if (!mep) { 1656 mutex_exit(&strresources); 1657 return (NULL); 1658 } 1659 for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { 1660 if ((!linkp->li_lblk.l_qtop) && 1661 (mep->me_muxid == linkp->li_lblk.l_index)) { 1662 mutex_exit(&strresources); 1663 return (linkp); 1664 } 1665 } 1666 } 1667 mutex_exit(&strresources); 1668 return (NULL); 1669 } 1670 1671 /* 1672 * Given a queue ptr, follow the chain of q_next pointers until you reach the 1673 * last queue on the chain and return it. 1674 */ 1675 queue_t * 1676 getendq(queue_t *q) 1677 { 1678 ASSERT(q != NULL); 1679 while (_SAMESTR(q)) 1680 q = q->q_next; 1681 return (q); 1682 } 1683 1684 /* 1685 * Wait for the syncq count to drop to zero. 1686 * sq could be either outer or inner. 1687 */ 1688 1689 static void 1690 wait_syncq(syncq_t *sq) 1691 { 1692 uint16_t count; 1693 1694 mutex_enter(SQLOCK(sq)); 1695 count = sq->sq_count; 1696 SQ_PUTLOCKS_ENTER(sq); 1697 SUM_SQ_PUTCOUNTS(sq, count); 1698 while (count != 0) { 1699 sq->sq_flags |= SQ_WANTWAKEUP; 1700 SQ_PUTLOCKS_EXIT(sq); 1701 cv_wait(&sq->sq_wait, SQLOCK(sq)); 1702 count = sq->sq_count; 1703 SQ_PUTLOCKS_ENTER(sq); 1704 SUM_SQ_PUTCOUNTS(sq, count); 1705 } 1706 SQ_PUTLOCKS_EXIT(sq); 1707 mutex_exit(SQLOCK(sq)); 1708 } 1709 1710 /* 1711 * Wait while there are any messages for the queue in its syncq. 1712 */ 1713 static void 1714 wait_q_syncq(queue_t *q) 1715 { 1716 if ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { 1717 syncq_t *sq = q->q_syncq; 1718 1719 mutex_enter(SQLOCK(sq)); 1720 while ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { 1721 sq->sq_flags |= SQ_WANTWAKEUP; 1722 cv_wait(&sq->sq_wait, SQLOCK(sq)); 1723 } 1724 mutex_exit(SQLOCK(sq)); 1725 } 1726 } 1727 1728 1729 int 1730 mlink_file(vnode_t *vp, int cmd, struct file *fpdown, cred_t *crp, int *rvalp, 1731 int lhlink) 1732 { 1733 struct stdata *stp; 1734 struct strioctl strioc; 1735 struct linkinfo *linkp; 1736 struct stdata *stpdown; 1737 struct streamtab *str; 1738 queue_t *passq; 1739 syncq_t *passyncq; 1740 queue_t *rq; 1741 cdevsw_impl_t *dp; 1742 uint32_t qflag; 1743 uint32_t sqtype; 1744 perdm_t *dmp; 1745 int error = 0; 1746 netstack_t *ns; 1747 str_stack_t *ss; 1748 1749 stp = vp->v_stream; 1750 TRACE_1(TR_FAC_STREAMS_FR, 1751 TR_I_LINK, "I_LINK/I_PLINK:stp %p", stp); 1752 /* 1753 * Test for invalid upper stream 1754 */ 1755 if (stp->sd_flag & STRHUP) { 1756 return (ENXIO); 1757 } 1758 if (vp->v_type == VFIFO) { 1759 return (EINVAL); 1760 } 1761 if (stp->sd_strtab == NULL) { 1762 return (EINVAL); 1763 } 1764 if (!stp->sd_strtab->st_muxwinit) { 1765 return (EINVAL); 1766 } 1767 if (fpdown == NULL) { 1768 return (EBADF); 1769 } 1770 ns = netstack_find_by_cred(crp); 1771 ASSERT(ns != NULL); 1772 ss = ns->netstack_str; 1773 ASSERT(ss != NULL); 1774 1775 if (getmajor(stp->sd_vnode->v_rdev) >= ss->ss_devcnt) { 1776 netstack_rele(ss->ss_netstack); 1777 return (EINVAL); 1778 } 1779 mutex_enter(&muxifier); 1780 if (stp->sd_flag & STPLEX) { 1781 mutex_exit(&muxifier); 1782 netstack_rele(ss->ss_netstack); 1783 return (ENXIO); 1784 } 1785 1786 /* 1787 * Test for invalid lower stream. 1788 * The check for the v_type != VFIFO and having a major 1789 * number not >= devcnt is done to avoid problems with 1790 * adding mux_node entry past the end of mux_nodes[]. 1791 * For FIFO's we don't add an entry so this isn't a 1792 * problem. 1793 */ 1794 if (((stpdown = fpdown->f_vnode->v_stream) == NULL) || 1795 (stpdown == stp) || (stpdown->sd_flag & 1796 (STPLEX|STRHUP|STRDERR|STWRERR|IOCWAIT|STRPLUMB)) || 1797 ((stpdown->sd_vnode->v_type != VFIFO) && 1798 (getmajor(stpdown->sd_vnode->v_rdev) >= ss->ss_devcnt)) || 1799 linkcycle(stp, stpdown, ss)) { 1800 mutex_exit(&muxifier); 1801 netstack_rele(ss->ss_netstack); 1802 return (EINVAL); 1803 } 1804 TRACE_1(TR_FAC_STREAMS_FR, 1805 TR_STPDOWN, "stpdown:%p", stpdown); 1806 rq = getendq(stp->sd_wrq); 1807 if (cmd == I_PLINK) 1808 rq = NULL; 1809 1810 linkp = alloclink(rq, stpdown->sd_wrq, fpdown); 1811 1812 strioc.ic_cmd = cmd; 1813 strioc.ic_timout = INFTIM; 1814 strioc.ic_len = sizeof (struct linkblk); 1815 strioc.ic_dp = (char *)&linkp->li_lblk; 1816 1817 /* 1818 * STRPLUMB protects plumbing changes and should be set before 1819 * link_addpassthru()/link_rempassthru() are called, so it is set here 1820 * and cleared in the end of mlink when passthru queue is removed. 1821 * Setting of STRPLUMB prevents reopens of the stream while passthru 1822 * queue is in-place (it is not a proper module and doesn't have open 1823 * entry point). 1824 * 1825 * STPLEX prevents any threads from entering the stream from above. It 1826 * can't be set before the call to link_addpassthru() because putnext 1827 * from below may cause stream head I/O routines to be called and these 1828 * routines assert that STPLEX is not set. After link_addpassthru() 1829 * nothing may come from below since the pass queue syncq is blocked. 1830 * Note also that STPLEX should be cleared before the call to 1831 * link_rempassthru() since when messages start flowing to the stream 1832 * head (e.g. because of message propagation from the pass queue) stream 1833 * head I/O routines may be called with STPLEX flag set. 1834 * 1835 * When STPLEX is set, nothing may come into the stream from above and 1836 * it is safe to do a setq which will change stream head. So, the 1837 * correct sequence of actions is: 1838 * 1839 * 1) Set STRPLUMB 1840 * 2) Call link_addpassthru() 1841 * 3) Set STPLEX 1842 * 4) Call setq and update the stream state 1843 * 5) Clear STPLEX 1844 * 6) Call link_rempassthru() 1845 * 7) Clear STRPLUMB 1846 * 1847 * The same sequence applies to munlink() code. 1848 */ 1849 mutex_enter(&stpdown->sd_lock); 1850 stpdown->sd_flag |= STRPLUMB; 1851 mutex_exit(&stpdown->sd_lock); 1852 /* 1853 * Add passthru queue below lower mux. This will block 1854 * syncqs of lower muxs read queue during I_LINK/I_UNLINK. 1855 */ 1856 passq = link_addpassthru(stpdown); 1857 1858 mutex_enter(&stpdown->sd_lock); 1859 stpdown->sd_flag |= STPLEX; 1860 mutex_exit(&stpdown->sd_lock); 1861 1862 rq = _RD(stpdown->sd_wrq); 1863 /* 1864 * There may be messages in the streamhead's syncq due to messages 1865 * that arrived before link_addpassthru() was done. To avoid 1866 * background processing of the syncq happening simultaneous with 1867 * setq processing, we disable the streamhead syncq and wait until 1868 * existing background thread finishes working on it. 1869 */ 1870 wait_sq_svc(rq->q_syncq); 1871 passyncq = passq->q_syncq; 1872 if (!(passyncq->sq_flags & SQ_BLOCKED)) 1873 blocksq(passyncq, SQ_BLOCKED, 0); 1874 1875 ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); 1876 ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); 1877 rq->q_ptr = _WR(rq)->q_ptr = NULL; 1878 1879 /* setq might sleep in allocator - avoid holding locks. */ 1880 /* Note: we are holding muxifier here. */ 1881 1882 str = stp->sd_strtab; 1883 dp = &devimpl[getmajor(vp->v_rdev)]; 1884 ASSERT(dp->d_str == str); 1885 1886 qflag = dp->d_qflag; 1887 sqtype = dp->d_sqtype; 1888 1889 /* create perdm_t if needed */ 1890 if (NEED_DM(dp->d_dmp, qflag)) 1891 dp->d_dmp = hold_dm(str, qflag, sqtype); 1892 1893 dmp = dp->d_dmp; 1894 1895 setq(rq, str->st_muxrinit, str->st_muxwinit, dmp, qflag, sqtype, 1896 B_TRUE); 1897 1898 /* 1899 * XXX Remove any "odd" messages from the queue. 1900 * Keep only M_DATA, M_PROTO, M_PCPROTO. 1901 */ 1902 error = strdoioctl(stp, &strioc, FNATIVE, 1903 K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); 1904 if (error != 0) { 1905 lbfree(linkp); 1906 1907 if (!(passyncq->sq_flags & SQ_BLOCKED)) 1908 blocksq(passyncq, SQ_BLOCKED, 0); 1909 /* 1910 * Restore the stream head queue and then remove 1911 * the passq. Turn off STPLEX before we turn on 1912 * the stream by removing the passq. 1913 */ 1914 rq->q_ptr = _WR(rq)->q_ptr = stpdown; 1915 setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, 1916 B_TRUE); 1917 1918 mutex_enter(&stpdown->sd_lock); 1919 stpdown->sd_flag &= ~STPLEX; 1920 mutex_exit(&stpdown->sd_lock); 1921 1922 link_rempassthru(passq); 1923 1924 mutex_enter(&stpdown->sd_lock); 1925 stpdown->sd_flag &= ~STRPLUMB; 1926 /* Wakeup anyone waiting for STRPLUMB to clear. */ 1927 cv_broadcast(&stpdown->sd_monitor); 1928 mutex_exit(&stpdown->sd_lock); 1929 1930 mutex_exit(&muxifier); 1931 netstack_rele(ss->ss_netstack); 1932 return (error); 1933 } 1934 mutex_enter(&fpdown->f_tlock); 1935 fpdown->f_count++; 1936 mutex_exit(&fpdown->f_tlock); 1937 1938 /* 1939 * if we've made it here the linkage is all set up so we should also 1940 * set up the layered driver linkages 1941 */ 1942 1943 ASSERT((cmd == I_LINK) || (cmd == I_PLINK)); 1944 if (cmd == I_LINK) { 1945 ldi_mlink_fp(stp, fpdown, lhlink, LINKNORMAL); 1946 } else { 1947 ldi_mlink_fp(stp, fpdown, lhlink, LINKPERSIST); 1948 } 1949 1950 link_rempassthru(passq); 1951 1952 mux_addedge(stp, stpdown, linkp->li_lblk.l_index, ss); 1953 1954 /* 1955 * Mark the upper stream as having dependent links 1956 * so that strclose can clean it up. 1957 */ 1958 if (cmd == I_LINK) { 1959 mutex_enter(&stp->sd_lock); 1960 stp->sd_flag |= STRHASLINKS; 1961 mutex_exit(&stp->sd_lock); 1962 } 1963 /* 1964 * Wake up any other processes that may have been 1965 * waiting on the lower stream. These will all 1966 * error out. 1967 */ 1968 mutex_enter(&stpdown->sd_lock); 1969 /* The passthru module is removed so we may release STRPLUMB */ 1970 stpdown->sd_flag &= ~STRPLUMB; 1971 cv_broadcast(&rq->q_wait); 1972 cv_broadcast(&_WR(rq)->q_wait); 1973 cv_broadcast(&stpdown->sd_monitor); 1974 mutex_exit(&stpdown->sd_lock); 1975 mutex_exit(&muxifier); 1976 *rvalp = linkp->li_lblk.l_index; 1977 netstack_rele(ss->ss_netstack); 1978 return (0); 1979 } 1980 1981 int 1982 mlink(vnode_t *vp, int cmd, int arg, cred_t *crp, int *rvalp, int lhlink) 1983 { 1984 int ret; 1985 struct file *fpdown; 1986 1987 fpdown = getf(arg); 1988 ret = mlink_file(vp, cmd, fpdown, crp, rvalp, lhlink); 1989 if (fpdown != NULL) 1990 releasef(arg); 1991 return (ret); 1992 } 1993 1994 /* 1995 * Unlink a multiplexor link. Stp is the controlling stream for the 1996 * link, and linkp points to the link's entry in the linkinfo list. 1997 * The muxifier lock must be held on entry and is dropped on exit. 1998 * 1999 * NOTE : Currently it is assumed that mux would process all the messages 2000 * sitting on it's queue before ACKing the UNLINK. It is the responsibility 2001 * of the mux to handle all the messages that arrive before UNLINK. 2002 * If the mux has to send down messages on its lower stream before 2003 * ACKing I_UNLINK, then it *should* know to handle messages even 2004 * after the UNLINK is acked (actually it should be able to handle till we 2005 * re-block the read side of the pass queue here). If the mux does not 2006 * open up the lower stream, any messages that arrive during UNLINK 2007 * will be put in the stream head. In the case of lower stream opening 2008 * up, some messages might land in the stream head depending on when 2009 * the message arrived and when the read side of the pass queue was 2010 * re-blocked. 2011 */ 2012 int 2013 munlink(stdata_t *stp, linkinfo_t *linkp, int flag, cred_t *crp, int *rvalp, 2014 str_stack_t *ss) 2015 { 2016 struct strioctl strioc; 2017 struct stdata *stpdown; 2018 queue_t *rq, *wrq; 2019 queue_t *passq; 2020 syncq_t *passyncq; 2021 int error = 0; 2022 file_t *fpdown; 2023 2024 ASSERT(MUTEX_HELD(&muxifier)); 2025 2026 stpdown = linkp->li_fpdown->f_vnode->v_stream; 2027 2028 /* 2029 * See the comment in mlink() concerning STRPLUMB/STPLEX flags. 2030 */ 2031 mutex_enter(&stpdown->sd_lock); 2032 stpdown->sd_flag |= STRPLUMB; 2033 mutex_exit(&stpdown->sd_lock); 2034 2035 /* 2036 * Add passthru queue below lower mux. This will block 2037 * syncqs of lower muxs read queue during I_LINK/I_UNLINK. 2038 */ 2039 passq = link_addpassthru(stpdown); 2040 2041 if ((flag & LINKTYPEMASK) == LINKNORMAL) 2042 strioc.ic_cmd = I_UNLINK; 2043 else 2044 strioc.ic_cmd = I_PUNLINK; 2045 strioc.ic_timout = INFTIM; 2046 strioc.ic_len = sizeof (struct linkblk); 2047 strioc.ic_dp = (char *)&linkp->li_lblk; 2048 2049 error = strdoioctl(stp, &strioc, FNATIVE, 2050 K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); 2051 2052 /* 2053 * If there was an error and this is not called via strclose, 2054 * return to the user. Otherwise, pretend there was no error 2055 * and close the link. 2056 */ 2057 if (error) { 2058 if (flag & LINKCLOSE) { 2059 cmn_err(CE_WARN, "KERNEL: munlink: could not perform " 2060 "unlink ioctl, closing anyway (%d)\n", error); 2061 } else { 2062 link_rempassthru(passq); 2063 mutex_enter(&stpdown->sd_lock); 2064 stpdown->sd_flag &= ~STRPLUMB; 2065 cv_broadcast(&stpdown->sd_monitor); 2066 mutex_exit(&stpdown->sd_lock); 2067 mutex_exit(&muxifier); 2068 return (error); 2069 } 2070 } 2071 2072 mux_rmvedge(stp, linkp->li_lblk.l_index, ss); 2073 fpdown = linkp->li_fpdown; 2074 lbfree(linkp); 2075 2076 /* 2077 * We go ahead and drop muxifier here--it's a nasty global lock that 2078 * can slow others down. It's okay to since attempts to mlink() this 2079 * stream will be stopped because STPLEX is still set in the stdata 2080 * structure, and munlink() is stopped because mux_rmvedge() and 2081 * lbfree() have removed it from mux_nodes[] and linkinfo_list, 2082 * respectively. Note that we defer the closef() of fpdown until 2083 * after we drop muxifier since strclose() can call munlinkall(). 2084 */ 2085 mutex_exit(&muxifier); 2086 2087 wrq = stpdown->sd_wrq; 2088 rq = _RD(wrq); 2089 2090 /* 2091 * Get rid of outstanding service procedure runs, before we make 2092 * it a stream head, since a stream head doesn't have any service 2093 * procedure. 2094 */ 2095 disable_svc(rq); 2096 wait_svc(rq); 2097 2098 /* 2099 * Since we don't disable the syncq for QPERMOD, we wait for whatever 2100 * is queued up to be finished. mux should take care that nothing is 2101 * send down to this queue. We should do it now as we're going to block 2102 * passyncq if it was unblocked. 2103 */ 2104 if (wrq->q_flag & QPERMOD) { 2105 syncq_t *sq = wrq->q_syncq; 2106 2107 mutex_enter(SQLOCK(sq)); 2108 while (wrq->q_sqflags & Q_SQQUEUED) { 2109 sq->sq_flags |= SQ_WANTWAKEUP; 2110 cv_wait(&sq->sq_wait, SQLOCK(sq)); 2111 } 2112 mutex_exit(SQLOCK(sq)); 2113 } 2114 passyncq = passq->q_syncq; 2115 if (!(passyncq->sq_flags & SQ_BLOCKED)) { 2116 2117 syncq_t *sq, *outer; 2118 2119 /* 2120 * Messages could be flowing from underneath. We will 2121 * block the read side of the passq. This would be 2122 * sufficient for QPAIR and QPERQ muxes to ensure 2123 * that no data is flowing up into this queue 2124 * and hence no thread active in this instance of 2125 * lower mux. But for QPERMOD and QMTOUTPERIM there 2126 * could be messages on the inner and outer/inner 2127 * syncqs respectively. We will wait for them to drain. 2128 * Because passq is blocked messages end up in the syncq 2129 * And qfill_syncq could possibly end up setting QFULL 2130 * which will access the rq->q_flag. Hence, we have to 2131 * acquire the QLOCK in setq. 2132 * 2133 * XXX Messages can also flow from top into this 2134 * queue though the unlink is over (Ex. some instance 2135 * in putnext() called from top that has still not 2136 * accessed this queue. And also putq(lowerq) ?). 2137 * Solution : How about blocking the l_qtop queue ? 2138 * Do we really care about such pure D_MP muxes ? 2139 */ 2140 2141 blocksq(passyncq, SQ_BLOCKED, 0); 2142 2143 sq = rq->q_syncq; 2144 if ((outer = sq->sq_outer) != NULL) { 2145 2146 /* 2147 * We have to just wait for the outer sq_count 2148 * drop to zero. As this does not prevent new 2149 * messages to enter the outer perimeter, this 2150 * is subject to starvation. 2151 * 2152 * NOTE :Because of blocksq above, messages could 2153 * be in the inner syncq only because of some 2154 * thread holding the outer perimeter exclusively. 2155 * Hence it would be sufficient to wait for the 2156 * exclusive holder of the outer perimeter to drain 2157 * the inner and outer syncqs. But we will not depend 2158 * on this feature and hence check the inner syncqs 2159 * separately. 2160 */ 2161 wait_syncq(outer); 2162 } 2163 2164 2165 /* 2166 * There could be messages destined for 2167 * this queue. Let the exclusive holder 2168 * drain it. 2169 */ 2170 2171 wait_syncq(sq); 2172 ASSERT((rq->q_flag & QPERMOD) || 2173 ((rq->q_syncq->sq_head == NULL) && 2174 (_WR(rq)->q_syncq->sq_head == NULL))); 2175 } 2176 2177 /* 2178 * We haven't taken care of QPERMOD case yet. QPERMOD is a special 2179 * case as we don't disable its syncq or remove it off the syncq 2180 * service list. 2181 */ 2182 if (rq->q_flag & QPERMOD) { 2183 syncq_t *sq = rq->q_syncq; 2184 2185 mutex_enter(SQLOCK(sq)); 2186 while (rq->q_sqflags & Q_SQQUEUED) { 2187 sq->sq_flags |= SQ_WANTWAKEUP; 2188 cv_wait(&sq->sq_wait, SQLOCK(sq)); 2189 } 2190 mutex_exit(SQLOCK(sq)); 2191 } 2192 2193 /* 2194 * flush_syncq changes states only when there are some messages to 2195 * free, i.e. when it returns non-zero value to return. 2196 */ 2197 ASSERT(flush_syncq(rq->q_syncq, rq) == 0); 2198 ASSERT(flush_syncq(wrq->q_syncq, wrq) == 0); 2199 2200 /* 2201 * Nobody else should know about this queue now. 2202 * If the mux did not process the messages before 2203 * acking the I_UNLINK, free them now. 2204 */ 2205 2206 flushq(rq, FLUSHALL); 2207 flushq(_WR(rq), FLUSHALL); 2208 2209 /* 2210 * Convert the mux lower queue into a stream head queue. 2211 * Turn off STPLEX before we turn on the stream by removing the passq. 2212 */ 2213 rq->q_ptr = wrq->q_ptr = stpdown; 2214 setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_TRUE); 2215 2216 ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); 2217 ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); 2218 2219 enable_svc(rq); 2220 2221 /* 2222 * Now it is a proper stream, so STPLEX is cleared. But STRPLUMB still 2223 * needs to be set to prevent reopen() of the stream - such reopen may 2224 * try to call non-existent pass queue open routine and panic. 2225 */ 2226 mutex_enter(&stpdown->sd_lock); 2227 stpdown->sd_flag &= ~STPLEX; 2228 mutex_exit(&stpdown->sd_lock); 2229 2230 ASSERT(((flag & LINKTYPEMASK) == LINKNORMAL) || 2231 ((flag & LINKTYPEMASK) == LINKPERSIST)); 2232 2233 /* clean up the layered driver linkages */ 2234 if ((flag & LINKTYPEMASK) == LINKNORMAL) { 2235 ldi_munlink_fp(stp, fpdown, LINKNORMAL); 2236 } else { 2237 ldi_munlink_fp(stp, fpdown, LINKPERSIST); 2238 } 2239 2240 link_rempassthru(passq); 2241 2242 /* 2243 * Now all plumbing changes are finished and STRPLUMB is no 2244 * longer needed. 2245 */ 2246 mutex_enter(&stpdown->sd_lock); 2247 stpdown->sd_flag &= ~STRPLUMB; 2248 cv_broadcast(&stpdown->sd_monitor); 2249 mutex_exit(&stpdown->sd_lock); 2250 2251 (void) closef(fpdown); 2252 return (0); 2253 } 2254 2255 /* 2256 * Unlink all multiplexor links for which stp is the controlling stream. 2257 * Return 0, or a non-zero errno on failure. 2258 */ 2259 int 2260 munlinkall(stdata_t *stp, int flag, cred_t *crp, int *rvalp, str_stack_t *ss) 2261 { 2262 linkinfo_t *linkp; 2263 int error = 0; 2264 2265 mutex_enter(&muxifier); 2266 while (linkp = findlinks(stp, 0, flag, ss)) { 2267 /* 2268 * munlink() releases the muxifier lock. 2269 */ 2270 if (error = munlink(stp, linkp, flag, crp, rvalp, ss)) 2271 return (error); 2272 mutex_enter(&muxifier); 2273 } 2274 mutex_exit(&muxifier); 2275 return (0); 2276 } 2277 2278 /* 2279 * A multiplexor link has been made. Add an 2280 * edge to the directed graph. 2281 */ 2282 void 2283 mux_addedge(stdata_t *upstp, stdata_t *lostp, int muxid, str_stack_t *ss) 2284 { 2285 struct mux_node *np; 2286 struct mux_edge *ep; 2287 major_t upmaj; 2288 major_t lomaj; 2289 2290 upmaj = getmajor(upstp->sd_vnode->v_rdev); 2291 lomaj = getmajor(lostp->sd_vnode->v_rdev); 2292 np = &ss->ss_mux_nodes[upmaj]; 2293 if (np->mn_outp) { 2294 ep = np->mn_outp; 2295 while (ep->me_nextp) 2296 ep = ep->me_nextp; 2297 ep->me_nextp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); 2298 ep = ep->me_nextp; 2299 } else { 2300 np->mn_outp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); 2301 ep = np->mn_outp; 2302 } 2303 ep->me_nextp = NULL; 2304 ep->me_muxid = muxid; 2305 /* 2306 * Save the dev_t for the purposes of str_stack_shutdown. 2307 * str_stack_shutdown assumes that the device allows reopen, since 2308 * this dev_t is the one after any cloning by xx_open(). 2309 * Would prefer finding the dev_t from before any cloning, 2310 * but specfs doesn't retain that. 2311 */ 2312 ep->me_dev = upstp->sd_vnode->v_rdev; 2313 if (lostp->sd_vnode->v_type == VFIFO) 2314 ep->me_nodep = NULL; 2315 else 2316 ep->me_nodep = &ss->ss_mux_nodes[lomaj]; 2317 } 2318 2319 /* 2320 * A multiplexor link has been removed. Remove the 2321 * edge in the directed graph. 2322 */ 2323 void 2324 mux_rmvedge(stdata_t *upstp, int muxid, str_stack_t *ss) 2325 { 2326 struct mux_node *np; 2327 struct mux_edge *ep; 2328 struct mux_edge *pep = NULL; 2329 major_t upmaj; 2330 2331 upmaj = getmajor(upstp->sd_vnode->v_rdev); 2332 np = &ss->ss_mux_nodes[upmaj]; 2333 ASSERT(np->mn_outp != NULL); 2334 ep = np->mn_outp; 2335 while (ep) { 2336 if (ep->me_muxid == muxid) { 2337 if (pep) 2338 pep->me_nextp = ep->me_nextp; 2339 else 2340 np->mn_outp = ep->me_nextp; 2341 kmem_free(ep, sizeof (struct mux_edge)); 2342 return; 2343 } 2344 pep = ep; 2345 ep = ep->me_nextp; 2346 } 2347 ASSERT(0); /* should not reach here */ 2348 } 2349 2350 /* 2351 * Translate the device flags (from conf.h) to the corresponding 2352 * qflag and sq_flag (type) values. 2353 */ 2354 int 2355 devflg_to_qflag(struct streamtab *stp, uint32_t devflag, uint32_t *qflagp, 2356 uint32_t *sqtypep) 2357 { 2358 uint32_t qflag = 0; 2359 uint32_t sqtype = 0; 2360 2361 if (devflag & _D_OLD) 2362 goto bad; 2363 2364 /* Inner perimeter presence and scope */ 2365 switch (devflag & D_MTINNER_MASK) { 2366 case D_MP: 2367 qflag |= QMTSAFE; 2368 sqtype |= SQ_CI; 2369 break; 2370 case D_MTPERQ|D_MP: 2371 qflag |= QPERQ; 2372 break; 2373 case D_MTQPAIR|D_MP: 2374 qflag |= QPAIR; 2375 break; 2376 case D_MTPERMOD|D_MP: 2377 qflag |= QPERMOD; 2378 break; 2379 default: 2380 goto bad; 2381 } 2382 2383 /* Outer perimeter */ 2384 if (devflag & D_MTOUTPERIM) { 2385 switch (devflag & D_MTINNER_MASK) { 2386 case D_MP: 2387 case D_MTPERQ|D_MP: 2388 case D_MTQPAIR|D_MP: 2389 break; 2390 default: 2391 goto bad; 2392 } 2393 qflag |= QMTOUTPERIM; 2394 } 2395 2396 /* Inner perimeter modifiers */ 2397 if (devflag & D_MTINNER_MOD) { 2398 switch (devflag & D_MTINNER_MASK) { 2399 case D_MP: 2400 goto bad; 2401 default: 2402 break; 2403 } 2404 if (devflag & D_MTPUTSHARED) 2405 sqtype |= SQ_CIPUT; 2406 if (devflag & _D_MTOCSHARED) { 2407 /* 2408 * The code in putnext assumes that it has the 2409 * highest concurrency by not checking sq_count. 2410 * Thus _D_MTOCSHARED can only be supported when 2411 * D_MTPUTSHARED is set. 2412 */ 2413 if (!(devflag & D_MTPUTSHARED)) 2414 goto bad; 2415 sqtype |= SQ_CIOC; 2416 } 2417 if (devflag & _D_MTCBSHARED) { 2418 /* 2419 * The code in putnext assumes that it has the 2420 * highest concurrency by not checking sq_count. 2421 * Thus _D_MTCBSHARED can only be supported when 2422 * D_MTPUTSHARED is set. 2423 */ 2424 if (!(devflag & D_MTPUTSHARED)) 2425 goto bad; 2426 sqtype |= SQ_CICB; 2427 } 2428 if (devflag & _D_MTSVCSHARED) { 2429 /* 2430 * The code in putnext assumes that it has the 2431 * highest concurrency by not checking sq_count. 2432 * Thus _D_MTSVCSHARED can only be supported when 2433 * D_MTPUTSHARED is set. Also _D_MTSVCSHARED is 2434 * supported only for QPERMOD. 2435 */ 2436 if (!(devflag & D_MTPUTSHARED) || !(qflag & QPERMOD)) 2437 goto bad; 2438 sqtype |= SQ_CISVC; 2439 } 2440 } 2441 2442 /* Default outer perimeter concurrency */ 2443 sqtype |= SQ_CO; 2444 2445 /* Outer perimeter modifiers */ 2446 if (devflag & D_MTOCEXCL) { 2447 if (!(devflag & D_MTOUTPERIM)) { 2448 /* No outer perimeter */ 2449 goto bad; 2450 } 2451 sqtype &= ~SQ_COOC; 2452 } 2453 2454 /* Synchronous Streams extended qinit structure */ 2455 if (devflag & D_SYNCSTR) 2456 qflag |= QSYNCSTR; 2457 2458 /* 2459 * Private flag used by a transport module to indicate 2460 * to sockfs that it supports direct-access mode without 2461 * having to go through STREAMS. 2462 */ 2463 if (devflag & _D_DIRECT) { 2464 /* Reject unless the module is fully-MT (no perimeter) */ 2465 if ((qflag & QMT_TYPEMASK) != QMTSAFE) 2466 goto bad; 2467 qflag |= _QDIRECT; 2468 } 2469 2470 /* 2471 * Private flag used to indicate that a streams module should only 2472 * be pushed once. The TTY streams modules have this flag since if 2473 * libc believes itself to be an xpg4 process then it will 2474 * automatically and unconditionally push them when a PTS device is 2475 * opened. If an application is not aware of this then without this 2476 * flag we would end up with duplicate modules. 2477 */ 2478 if (devflag & _D_SINGLE_INSTANCE) 2479 qflag |= _QSINGLE_INSTANCE; 2480 2481 *qflagp = qflag; 2482 *sqtypep = sqtype; 2483 return (0); 2484 2485 bad: 2486 cmn_err(CE_WARN, 2487 "stropen: bad MT flags (0x%x) in driver '%s'", 2488 (int)(qflag & D_MTSAFETY_MASK), 2489 stp->st_rdinit->qi_minfo->mi_idname); 2490 2491 return (EINVAL); 2492 } 2493 2494 /* 2495 * Set the interface values for a pair of queues (qinit structure, 2496 * packet sizes, water marks). 2497 * setq assumes that the caller does not have a claim (entersq or claimq) 2498 * on the queue. 2499 */ 2500 void 2501 setq(queue_t *rq, struct qinit *rinit, struct qinit *winit, 2502 perdm_t *dmp, uint32_t qflag, uint32_t sqtype, boolean_t lock_needed) 2503 { 2504 queue_t *wq; 2505 syncq_t *sq, *outer; 2506 2507 ASSERT(rq->q_flag & QREADR); 2508 ASSERT((qflag & QMT_TYPEMASK) != 0); 2509 IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); 2510 2511 wq = _WR(rq); 2512 rq->q_qinfo = rinit; 2513 rq->q_hiwat = rinit->qi_minfo->mi_hiwat; 2514 rq->q_lowat = rinit->qi_minfo->mi_lowat; 2515 rq->q_minpsz = rinit->qi_minfo->mi_minpsz; 2516 rq->q_maxpsz = rinit->qi_minfo->mi_maxpsz; 2517 wq->q_qinfo = winit; 2518 wq->q_hiwat = winit->qi_minfo->mi_hiwat; 2519 wq->q_lowat = winit->qi_minfo->mi_lowat; 2520 wq->q_minpsz = winit->qi_minfo->mi_minpsz; 2521 wq->q_maxpsz = winit->qi_minfo->mi_maxpsz; 2522 2523 /* Remove old syncqs */ 2524 sq = rq->q_syncq; 2525 outer = sq->sq_outer; 2526 if (outer != NULL) { 2527 ASSERT(wq->q_syncq->sq_outer == outer); 2528 outer_remove(outer, rq->q_syncq); 2529 if (wq->q_syncq != rq->q_syncq) 2530 outer_remove(outer, wq->q_syncq); 2531 } 2532 ASSERT(sq->sq_outer == NULL); 2533 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 2534 2535 if (sq != SQ(rq)) { 2536 if (!(rq->q_flag & QPERMOD)) 2537 free_syncq(sq); 2538 if (wq->q_syncq == rq->q_syncq) 2539 wq->q_syncq = NULL; 2540 rq->q_syncq = NULL; 2541 } 2542 if (wq->q_syncq != NULL && wq->q_syncq != sq && 2543 wq->q_syncq != SQ(rq)) { 2544 free_syncq(wq->q_syncq); 2545 wq->q_syncq = NULL; 2546 } 2547 ASSERT(rq->q_syncq == NULL || (rq->q_syncq->sq_head == NULL && 2548 rq->q_syncq->sq_tail == NULL)); 2549 ASSERT(wq->q_syncq == NULL || (wq->q_syncq->sq_head == NULL && 2550 wq->q_syncq->sq_tail == NULL)); 2551 2552 if (!(rq->q_flag & QPERMOD) && 2553 rq->q_syncq != NULL && rq->q_syncq->sq_ciputctrl != NULL) { 2554 ASSERT(rq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); 2555 SUMCHECK_CIPUTCTRL_COUNTS(rq->q_syncq->sq_ciputctrl, 2556 rq->q_syncq->sq_nciputctrl, 0); 2557 ASSERT(ciputctrl_cache != NULL); 2558 kmem_cache_free(ciputctrl_cache, rq->q_syncq->sq_ciputctrl); 2559 rq->q_syncq->sq_ciputctrl = NULL; 2560 rq->q_syncq->sq_nciputctrl = 0; 2561 } 2562 2563 if (!(wq->q_flag & QPERMOD) && 2564 wq->q_syncq != NULL && wq->q_syncq->sq_ciputctrl != NULL) { 2565 ASSERT(wq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); 2566 SUMCHECK_CIPUTCTRL_COUNTS(wq->q_syncq->sq_ciputctrl, 2567 wq->q_syncq->sq_nciputctrl, 0); 2568 ASSERT(ciputctrl_cache != NULL); 2569 kmem_cache_free(ciputctrl_cache, wq->q_syncq->sq_ciputctrl); 2570 wq->q_syncq->sq_ciputctrl = NULL; 2571 wq->q_syncq->sq_nciputctrl = 0; 2572 } 2573 2574 sq = SQ(rq); 2575 ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); 2576 ASSERT(sq->sq_outer == NULL); 2577 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 2578 2579 /* 2580 * Create syncqs based on qflag and sqtype. Set the SQ_TYPES_IN_FLAGS 2581 * bits in sq_flag based on the sqtype. 2582 */ 2583 ASSERT((sq->sq_flags & ~SQ_TYPES_IN_FLAGS) == 0); 2584 2585 rq->q_syncq = wq->q_syncq = sq; 2586 sq->sq_type = sqtype; 2587 sq->sq_flags = (sqtype & SQ_TYPES_IN_FLAGS); 2588 2589 /* 2590 * We are making sq_svcflags zero, 2591 * resetting SQ_DISABLED in case it was set by 2592 * wait_svc() in the munlink path. 2593 * 2594 */ 2595 ASSERT((sq->sq_svcflags & SQ_SERVICE) == 0); 2596 sq->sq_svcflags = 0; 2597 2598 /* 2599 * We need to acquire the lock here for the mlink and munlink case, 2600 * where canputnext, backenable, etc can access the q_flag. 2601 */ 2602 if (lock_needed) { 2603 mutex_enter(QLOCK(rq)); 2604 rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2605 mutex_exit(QLOCK(rq)); 2606 mutex_enter(QLOCK(wq)); 2607 wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2608 mutex_exit(QLOCK(wq)); 2609 } else { 2610 rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2611 wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; 2612 } 2613 2614 if (qflag & QPERQ) { 2615 /* Allocate a separate syncq for the write side */ 2616 sq = new_syncq(); 2617 sq->sq_type = rq->q_syncq->sq_type; 2618 sq->sq_flags = rq->q_syncq->sq_flags; 2619 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 2620 sq->sq_oprev == NULL); 2621 wq->q_syncq = sq; 2622 } 2623 if (qflag & QPERMOD) { 2624 sq = dmp->dm_sq; 2625 2626 /* 2627 * Assert that we do have an inner perimeter syncq and that it 2628 * does not have an outer perimeter associated with it. 2629 */ 2630 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 2631 sq->sq_oprev == NULL); 2632 rq->q_syncq = wq->q_syncq = sq; 2633 } 2634 if (qflag & QMTOUTPERIM) { 2635 outer = dmp->dm_sq; 2636 2637 ASSERT(outer->sq_outer == NULL); 2638 outer_insert(outer, rq->q_syncq); 2639 if (wq->q_syncq != rq->q_syncq) 2640 outer_insert(outer, wq->q_syncq); 2641 } 2642 ASSERT((rq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == 2643 (rq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); 2644 ASSERT((wq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == 2645 (wq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); 2646 ASSERT((rq->q_flag & QMT_TYPEMASK) == (qflag & QMT_TYPEMASK)); 2647 2648 /* 2649 * Initialize struio() types. 2650 */ 2651 rq->q_struiot = 2652 (rq->q_flag & QSYNCSTR) ? rinit->qi_struiot : STRUIOT_NONE; 2653 wq->q_struiot = 2654 (wq->q_flag & QSYNCSTR) ? winit->qi_struiot : STRUIOT_NONE; 2655 } 2656 2657 perdm_t * 2658 hold_dm(struct streamtab *str, uint32_t qflag, uint32_t sqtype) 2659 { 2660 syncq_t *sq; 2661 perdm_t **pp; 2662 perdm_t *p; 2663 perdm_t *dmp; 2664 2665 ASSERT(str != NULL); 2666 ASSERT(qflag & (QPERMOD | QMTOUTPERIM)); 2667 2668 rw_enter(&perdm_rwlock, RW_READER); 2669 for (p = perdm_list; p != NULL; p = p->dm_next) { 2670 if (p->dm_str == str) { /* found one */ 2671 atomic_inc_32(&(p->dm_ref)); 2672 rw_exit(&perdm_rwlock); 2673 return (p); 2674 } 2675 } 2676 rw_exit(&perdm_rwlock); 2677 2678 sq = new_syncq(); 2679 if (qflag & QPERMOD) { 2680 sq->sq_type = sqtype | SQ_PERMOD; 2681 sq->sq_flags = sqtype & SQ_TYPES_IN_FLAGS; 2682 } else { 2683 ASSERT(qflag & QMTOUTPERIM); 2684 sq->sq_onext = sq->sq_oprev = sq; 2685 } 2686 2687 dmp = kmem_alloc(sizeof (perdm_t), KM_SLEEP); 2688 dmp->dm_sq = sq; 2689 dmp->dm_str = str; 2690 dmp->dm_ref = 1; 2691 dmp->dm_next = NULL; 2692 2693 rw_enter(&perdm_rwlock, RW_WRITER); 2694 for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) { 2695 if (p->dm_str == str) { /* already present */ 2696 p->dm_ref++; 2697 rw_exit(&perdm_rwlock); 2698 free_syncq(sq); 2699 kmem_free(dmp, sizeof (perdm_t)); 2700 return (p); 2701 } 2702 } 2703 2704 *pp = dmp; 2705 rw_exit(&perdm_rwlock); 2706 return (dmp); 2707 } 2708 2709 void 2710 rele_dm(perdm_t *dmp) 2711 { 2712 perdm_t **pp; 2713 perdm_t *p; 2714 2715 rw_enter(&perdm_rwlock, RW_WRITER); 2716 ASSERT(dmp->dm_ref > 0); 2717 2718 if (--dmp->dm_ref > 0) { 2719 rw_exit(&perdm_rwlock); 2720 return; 2721 } 2722 2723 for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) 2724 if (p == dmp) 2725 break; 2726 ASSERT(p == dmp); 2727 *pp = p->dm_next; 2728 rw_exit(&perdm_rwlock); 2729 2730 /* 2731 * Wait for any background processing that relies on the 2732 * syncq to complete before it is freed. 2733 */ 2734 wait_sq_svc(p->dm_sq); 2735 free_syncq(p->dm_sq); 2736 kmem_free(p, sizeof (perdm_t)); 2737 } 2738 2739 /* 2740 * Make a protocol message given control and data buffers. 2741 * n.b., this can block; be careful of what locks you hold when calling it. 2742 * 2743 * If sd_maxblk is less than *iosize this routine can fail part way through 2744 * (due to an allocation failure). In this case on return *iosize will contain 2745 * the amount that was consumed. Otherwise *iosize will not be modified 2746 * i.e. it will contain the amount that was consumed. 2747 */ 2748 int 2749 strmakemsg( 2750 struct strbuf *mctl, 2751 ssize_t *iosize, 2752 struct uio *uiop, 2753 stdata_t *stp, 2754 int32_t flag, 2755 mblk_t **mpp) 2756 { 2757 mblk_t *mpctl = NULL; 2758 mblk_t *mpdata = NULL; 2759 int error; 2760 2761 ASSERT(uiop != NULL); 2762 2763 *mpp = NULL; 2764 /* Create control part, if any */ 2765 if ((mctl != NULL) && (mctl->len >= 0)) { 2766 error = strmakectl(mctl, flag, uiop->uio_fmode, &mpctl); 2767 if (error) 2768 return (error); 2769 } 2770 /* Create data part, if any */ 2771 if (*iosize >= 0) { 2772 error = strmakedata(iosize, uiop, stp, flag, &mpdata); 2773 if (error) { 2774 freemsg(mpctl); 2775 return (error); 2776 } 2777 } 2778 if (mpctl != NULL) { 2779 if (mpdata != NULL) 2780 linkb(mpctl, mpdata); 2781 *mpp = mpctl; 2782 } else { 2783 *mpp = mpdata; 2784 } 2785 return (0); 2786 } 2787 2788 /* 2789 * Make the control part of a protocol message given a control buffer. 2790 * n.b., this can block; be careful of what locks you hold when calling it. 2791 */ 2792 int 2793 strmakectl( 2794 struct strbuf *mctl, 2795 int32_t flag, 2796 int32_t fflag, 2797 mblk_t **mpp) 2798 { 2799 mblk_t *bp = NULL; 2800 unsigned char msgtype; 2801 int error = 0; 2802 cred_t *cr = CRED(); 2803 2804 /* We do not support interrupt threads using the stream head to send */ 2805 ASSERT(cr != NULL); 2806 2807 *mpp = NULL; 2808 /* 2809 * Create control part of message, if any. 2810 */ 2811 if ((mctl != NULL) && (mctl->len >= 0)) { 2812 caddr_t base; 2813 int ctlcount; 2814 int allocsz; 2815 2816 if (flag & RS_HIPRI) 2817 msgtype = M_PCPROTO; 2818 else 2819 msgtype = M_PROTO; 2820 2821 ctlcount = mctl->len; 2822 base = mctl->buf; 2823 2824 /* 2825 * Give modules a better chance to reuse M_PROTO/M_PCPROTO 2826 * blocks by increasing the size to something more usable. 2827 */ 2828 allocsz = MAX(ctlcount, 64); 2829 2830 /* 2831 * Range checking has already been done; simply try 2832 * to allocate a message block for the ctl part. 2833 */ 2834 while ((bp = allocb_cred(allocsz, cr, 2835 curproc->p_pid)) == NULL) { 2836 if (fflag & (FNDELAY|FNONBLOCK)) 2837 return (EAGAIN); 2838 if (error = strwaitbuf(allocsz, BPRI_MED)) 2839 return (error); 2840 } 2841 2842 bp->b_datap->db_type = msgtype; 2843 if (copyin(base, bp->b_wptr, ctlcount)) { 2844 freeb(bp); 2845 return (EFAULT); 2846 } 2847 bp->b_wptr += ctlcount; 2848 } 2849 *mpp = bp; 2850 return (0); 2851 } 2852 2853 /* 2854 * Make a protocol message given data buffers. 2855 * n.b., this can block; be careful of what locks you hold when calling it. 2856 * 2857 * If sd_maxblk is less than *iosize this routine can fail part way through 2858 * (due to an allocation failure). In this case on return *iosize will contain 2859 * the amount that was consumed. Otherwise *iosize will not be modified 2860 * i.e. it will contain the amount that was consumed. 2861 */ 2862 int 2863 strmakedata( 2864 ssize_t *iosize, 2865 struct uio *uiop, 2866 stdata_t *stp, 2867 int32_t flag, 2868 mblk_t **mpp) 2869 { 2870 mblk_t *mp = NULL; 2871 mblk_t *bp; 2872 int wroff = (int)stp->sd_wroff; 2873 int tail_len = (int)stp->sd_tail; 2874 int extra = wroff + tail_len; 2875 int error = 0; 2876 ssize_t maxblk; 2877 ssize_t count = *iosize; 2878 cred_t *cr; 2879 2880 *mpp = NULL; 2881 if (count < 0) 2882 return (0); 2883 2884 /* We do not support interrupt threads using the stream head to send */ 2885 cr = CRED(); 2886 ASSERT(cr != NULL); 2887 2888 maxblk = stp->sd_maxblk; 2889 if (maxblk == INFPSZ) 2890 maxblk = count; 2891 2892 /* 2893 * Create data part of message, if any. 2894 */ 2895 do { 2896 ssize_t size; 2897 dblk_t *dp; 2898 2899 ASSERT(uiop); 2900 2901 size = MIN(count, maxblk); 2902 2903 while ((bp = allocb_cred(size + extra, cr, 2904 curproc->p_pid)) == NULL) { 2905 error = EAGAIN; 2906 if ((uiop->uio_fmode & (FNDELAY|FNONBLOCK)) || 2907 (error = strwaitbuf(size + extra, BPRI_MED)) != 0) { 2908 if (count == *iosize) { 2909 freemsg(mp); 2910 return (error); 2911 } else { 2912 *iosize -= count; 2913 *mpp = mp; 2914 return (0); 2915 } 2916 } 2917 } 2918 dp = bp->b_datap; 2919 dp->db_cpid = curproc->p_pid; 2920 ASSERT(wroff <= dp->db_lim - bp->b_wptr); 2921 bp->b_wptr = bp->b_rptr = bp->b_rptr + wroff; 2922 2923 if (flag & STRUIO_POSTPONE) { 2924 /* 2925 * Setup the stream uio portion of the 2926 * dblk for subsequent use by struioget(). 2927 */ 2928 dp->db_struioflag = STRUIO_SPEC; 2929 dp->db_cksumstart = 0; 2930 dp->db_cksumstuff = 0; 2931 dp->db_cksumend = size; 2932 *(long long *)dp->db_struioun.data = 0ll; 2933 bp->b_wptr += size; 2934 } else { 2935 if (stp->sd_copyflag & STRCOPYCACHED) 2936 uiop->uio_extflg |= UIO_COPY_CACHED; 2937 2938 if (size != 0) { 2939 error = uiomove(bp->b_wptr, size, UIO_WRITE, 2940 uiop); 2941 if (error != 0) { 2942 freeb(bp); 2943 freemsg(mp); 2944 return (error); 2945 } 2946 } 2947 bp->b_wptr += size; 2948 2949 if (stp->sd_wputdatafunc != NULL) { 2950 mblk_t *newbp; 2951 2952 newbp = (stp->sd_wputdatafunc)(stp->sd_vnode, 2953 bp, NULL, NULL, NULL, NULL); 2954 if (newbp == NULL) { 2955 freeb(bp); 2956 freemsg(mp); 2957 return (ECOMM); 2958 } 2959 bp = newbp; 2960 } 2961 } 2962 2963 count -= size; 2964 2965 if (mp == NULL) 2966 mp = bp; 2967 else 2968 linkb(mp, bp); 2969 } while (count > 0); 2970 2971 *mpp = mp; 2972 return (0); 2973 } 2974 2975 /* 2976 * Wait for a buffer to become available. Return non-zero errno 2977 * if not able to wait, 0 if buffer is probably there. 2978 */ 2979 int 2980 strwaitbuf(size_t size, int pri) 2981 { 2982 bufcall_id_t id; 2983 2984 mutex_enter(&bcall_monitor); 2985 if ((id = bufcall(size, pri, (void (*)(void *))cv_broadcast, 2986 &ttoproc(curthread)->p_flag_cv)) == 0) { 2987 mutex_exit(&bcall_monitor); 2988 return (ENOSR); 2989 } 2990 if (!cv_wait_sig(&(ttoproc(curthread)->p_flag_cv), &bcall_monitor)) { 2991 unbufcall(id); 2992 mutex_exit(&bcall_monitor); 2993 return (EINTR); 2994 } 2995 unbufcall(id); 2996 mutex_exit(&bcall_monitor); 2997 return (0); 2998 } 2999 3000 /* 3001 * This function waits for a read or write event to happen on a stream. 3002 * fmode can specify FNDELAY and/or FNONBLOCK. 3003 * The timeout is in ms with -1 meaning infinite. 3004 * The flag values work as follows: 3005 * READWAIT Check for read side errors, send M_READ 3006 * GETWAIT Check for read side errors, no M_READ 3007 * WRITEWAIT Check for write side errors. 3008 * NOINTR Do not return error if nonblocking or timeout. 3009 * STR_NOERROR Ignore all errors except STPLEX. 3010 * STR_NOSIG Ignore/hold signals during the duration of the call. 3011 * STR_PEEK Pass through the strgeterr(). 3012 */ 3013 int 3014 strwaitq(stdata_t *stp, int flag, ssize_t count, int fmode, clock_t timout, 3015 int *done) 3016 { 3017 int slpflg, errs; 3018 int error; 3019 kcondvar_t *sleepon; 3020 mblk_t *mp; 3021 ssize_t *rd_count; 3022 clock_t rval; 3023 3024 ASSERT(MUTEX_HELD(&stp->sd_lock)); 3025 if ((flag & READWAIT) || (flag & GETWAIT)) { 3026 slpflg = RSLEEP; 3027 sleepon = &_RD(stp->sd_wrq)->q_wait; 3028 errs = STRDERR|STPLEX; 3029 } else { 3030 slpflg = WSLEEP; 3031 sleepon = &stp->sd_wrq->q_wait; 3032 errs = STWRERR|STRHUP|STPLEX; 3033 } 3034 if (flag & STR_NOERROR) 3035 errs = STPLEX; 3036 3037 if (stp->sd_wakeq & slpflg) { 3038 /* 3039 * A strwakeq() is pending, no need to sleep. 3040 */ 3041 stp->sd_wakeq &= ~slpflg; 3042 *done = 0; 3043 return (0); 3044 } 3045 3046 if (stp->sd_flag & errs) { 3047 /* 3048 * Check for errors before going to sleep since the 3049 * caller might not have checked this while holding 3050 * sd_lock. 3051 */ 3052 error = strgeterr(stp, errs, (flag & STR_PEEK)); 3053 if (error != 0) { 3054 *done = 1; 3055 return (error); 3056 } 3057 } 3058 3059 /* 3060 * If any module downstream has requested read notification 3061 * by setting SNDMREAD flag using M_SETOPTS, send a message 3062 * down stream. 3063 */ 3064 if ((flag & READWAIT) && (stp->sd_flag & SNDMREAD)) { 3065 mutex_exit(&stp->sd_lock); 3066 if (!(mp = allocb_wait(sizeof (ssize_t), BPRI_MED, 3067 (flag & STR_NOSIG), &error))) { 3068 mutex_enter(&stp->sd_lock); 3069 *done = 1; 3070 return (error); 3071 } 3072 mp->b_datap->db_type = M_READ; 3073 rd_count = (ssize_t *)mp->b_wptr; 3074 *rd_count = count; 3075 mp->b_wptr += sizeof (ssize_t); 3076 /* 3077 * Send the number of bytes requested by the 3078 * read as the argument to M_READ. 3079 */ 3080 stream_willservice(stp); 3081 putnext(stp->sd_wrq, mp); 3082 stream_runservice(stp); 3083 mutex_enter(&stp->sd_lock); 3084 3085 /* 3086 * If any data arrived due to inline processing 3087 * of putnext(), don't sleep. 3088 */ 3089 if (_RD(stp->sd_wrq)->q_first != NULL) { 3090 *done = 0; 3091 return (0); 3092 } 3093 } 3094 3095 if (fmode & (FNDELAY|FNONBLOCK)) { 3096 if (!(flag & NOINTR)) 3097 error = EAGAIN; 3098 else 3099 error = 0; 3100 *done = 1; 3101 return (error); 3102 } 3103 3104 stp->sd_flag |= slpflg; 3105 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAIT2, 3106 "strwaitq sleeps (2):%p, %X, %lX, %X, %p", 3107 stp, flag, count, fmode, done); 3108 3109 rval = str_cv_wait(sleepon, &stp->sd_lock, timout, flag & STR_NOSIG); 3110 if (rval > 0) { 3111 /* EMPTY */ 3112 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAKE2, 3113 "strwaitq awakes(2):%X, %X, %X, %X, %X", 3114 stp, flag, count, fmode, done); 3115 } else if (rval == 0) { 3116 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_INTR2, 3117 "strwaitq interrupt #2:%p, %X, %lX, %X, %p", 3118 stp, flag, count, fmode, done); 3119 stp->sd_flag &= ~slpflg; 3120 cv_broadcast(sleepon); 3121 if (!(flag & NOINTR)) 3122 error = EINTR; 3123 else 3124 error = 0; 3125 *done = 1; 3126 return (error); 3127 } else { 3128 /* timeout */ 3129 TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_TIME, 3130 "strwaitq timeout:%p, %X, %lX, %X, %p", 3131 stp, flag, count, fmode, done); 3132 *done = 1; 3133 if (!(flag & NOINTR)) 3134 return (ETIME); 3135 else 3136 return (0); 3137 } 3138 /* 3139 * If the caller implements delayed errors (i.e. queued after data) 3140 * we can not check for errors here since data as well as an 3141 * error might have arrived at the stream head. We return to 3142 * have the caller check the read queue before checking for errors. 3143 */ 3144 if ((stp->sd_flag & errs) && !(flag & STR_DELAYERR)) { 3145 error = strgeterr(stp, errs, (flag & STR_PEEK)); 3146 if (error != 0) { 3147 *done = 1; 3148 return (error); 3149 } 3150 } 3151 *done = 0; 3152 return (0); 3153 } 3154 3155 /* 3156 * Perform job control discipline access checks. 3157 * Return 0 for success and the errno for failure. 3158 */ 3159 3160 #define cantsend(p, t, sig) \ 3161 (sigismember(&(p)->p_ignore, sig) || signal_is_blocked((t), sig)) 3162 3163 int 3164 straccess(struct stdata *stp, enum jcaccess mode) 3165 { 3166 extern kcondvar_t lbolt_cv; /* XXX: should be in a header file */ 3167 kthread_t *t = curthread; 3168 proc_t *p = ttoproc(t); 3169 sess_t *sp; 3170 3171 ASSERT(mutex_owned(&stp->sd_lock)); 3172 3173 if (stp->sd_sidp == NULL || stp->sd_vnode->v_type == VFIFO) 3174 return (0); 3175 3176 mutex_enter(&p->p_lock); /* protects p_pgidp */ 3177 3178 for (;;) { 3179 mutex_enter(&p->p_splock); /* protects p->p_sessp */ 3180 sp = p->p_sessp; 3181 mutex_enter(&sp->s_lock); /* protects sp->* */ 3182 3183 /* 3184 * If this is not the calling process's controlling terminal 3185 * or if the calling process is already in the foreground 3186 * then allow access. 3187 */ 3188 if (sp->s_dev != stp->sd_vnode->v_rdev || 3189 p->p_pgidp == stp->sd_pgidp) { 3190 mutex_exit(&sp->s_lock); 3191 mutex_exit(&p->p_splock); 3192 mutex_exit(&p->p_lock); 3193 return (0); 3194 } 3195 3196 /* 3197 * Check to see if controlling terminal has been deallocated. 3198 */ 3199 if (sp->s_vp == NULL) { 3200 if (!cantsend(p, t, SIGHUP)) 3201 sigtoproc(p, t, SIGHUP); 3202 mutex_exit(&sp->s_lock); 3203 mutex_exit(&p->p_splock); 3204 mutex_exit(&p->p_lock); 3205 return (EIO); 3206 } 3207 3208 mutex_exit(&sp->s_lock); 3209 mutex_exit(&p->p_splock); 3210 3211 if (mode == JCGETP) { 3212 mutex_exit(&p->p_lock); 3213 return (0); 3214 } 3215 3216 if (mode == JCREAD) { 3217 if (p->p_detached || cantsend(p, t, SIGTTIN)) { 3218 mutex_exit(&p->p_lock); 3219 return (EIO); 3220 } 3221 mutex_exit(&p->p_lock); 3222 mutex_exit(&stp->sd_lock); 3223 pgsignal(p->p_pgidp, SIGTTIN); 3224 mutex_enter(&stp->sd_lock); 3225 mutex_enter(&p->p_lock); 3226 } else { /* mode == JCWRITE or JCSETP */ 3227 if ((mode == JCWRITE && !(stp->sd_flag & STRTOSTOP)) || 3228 cantsend(p, t, SIGTTOU)) { 3229 mutex_exit(&p->p_lock); 3230 return (0); 3231 } 3232 if (p->p_detached) { 3233 mutex_exit(&p->p_lock); 3234 return (EIO); 3235 } 3236 mutex_exit(&p->p_lock); 3237 mutex_exit(&stp->sd_lock); 3238 pgsignal(p->p_pgidp, SIGTTOU); 3239 mutex_enter(&stp->sd_lock); 3240 mutex_enter(&p->p_lock); 3241 } 3242 3243 /* 3244 * We call cv_wait_sig_swap() to cause the appropriate 3245 * action for the jobcontrol signal to take place. 3246 * If the signal is being caught, we will take the 3247 * EINTR error return. Otherwise, the default action 3248 * of causing the process to stop will take place. 3249 * In this case, we rely on the periodic cv_broadcast() on 3250 * &lbolt_cv to wake us up to loop around and test again. 3251 * We can't get here if the signal is ignored or 3252 * if the current thread is blocking the signal. 3253 */ 3254 mutex_exit(&stp->sd_lock); 3255 if (!cv_wait_sig_swap(&lbolt_cv, &p->p_lock)) { 3256 mutex_exit(&p->p_lock); 3257 mutex_enter(&stp->sd_lock); 3258 return (EINTR); 3259 } 3260 mutex_exit(&p->p_lock); 3261 mutex_enter(&stp->sd_lock); 3262 mutex_enter(&p->p_lock); 3263 } 3264 } 3265 3266 /* 3267 * Return size of message of block type (bp->b_datap->db_type) 3268 */ 3269 size_t 3270 xmsgsize(mblk_t *bp) 3271 { 3272 unsigned char type; 3273 size_t count = 0; 3274 3275 type = bp->b_datap->db_type; 3276 3277 for (; bp; bp = bp->b_cont) { 3278 if (type != bp->b_datap->db_type) 3279 break; 3280 ASSERT(bp->b_wptr >= bp->b_rptr); 3281 count += bp->b_wptr - bp->b_rptr; 3282 } 3283 return (count); 3284 } 3285 3286 /* 3287 * Allocate a stream head. 3288 */ 3289 struct stdata * 3290 shalloc(queue_t *qp) 3291 { 3292 stdata_t *stp; 3293 3294 stp = kmem_cache_alloc(stream_head_cache, KM_SLEEP); 3295 3296 stp->sd_wrq = _WR(qp); 3297 stp->sd_strtab = NULL; 3298 stp->sd_iocid = 0; 3299 stp->sd_mate = NULL; 3300 stp->sd_freezer = NULL; 3301 stp->sd_refcnt = 0; 3302 stp->sd_wakeq = 0; 3303 stp->sd_anchor = 0; 3304 stp->sd_struiowrq = NULL; 3305 stp->sd_struiordq = NULL; 3306 stp->sd_struiodnak = 0; 3307 stp->sd_struionak = NULL; 3308 stp->sd_t_audit_data = NULL; 3309 stp->sd_rput_opt = 0; 3310 stp->sd_wput_opt = 0; 3311 stp->sd_read_opt = 0; 3312 stp->sd_rprotofunc = strrput_proto; 3313 stp->sd_rmiscfunc = strrput_misc; 3314 stp->sd_rderrfunc = stp->sd_wrerrfunc = NULL; 3315 stp->sd_rputdatafunc = stp->sd_wputdatafunc = NULL; 3316 stp->sd_ciputctrl = NULL; 3317 stp->sd_nciputctrl = 0; 3318 stp->sd_qhead = NULL; 3319 stp->sd_qtail = NULL; 3320 stp->sd_servid = NULL; 3321 stp->sd_nqueues = 0; 3322 stp->sd_svcflags = 0; 3323 stp->sd_copyflag = 0; 3324 3325 return (stp); 3326 } 3327 3328 /* 3329 * Free a stream head. 3330 */ 3331 void 3332 shfree(stdata_t *stp) 3333 { 3334 ASSERT(MUTEX_NOT_HELD(&stp->sd_lock)); 3335 3336 stp->sd_wrq = NULL; 3337 3338 mutex_enter(&stp->sd_qlock); 3339 while (stp->sd_svcflags & STRS_SCHEDULED) { 3340 STRSTAT(strwaits); 3341 cv_wait(&stp->sd_qcv, &stp->sd_qlock); 3342 } 3343 mutex_exit(&stp->sd_qlock); 3344 3345 if (stp->sd_ciputctrl != NULL) { 3346 ASSERT(stp->sd_nciputctrl == n_ciputctrl - 1); 3347 SUMCHECK_CIPUTCTRL_COUNTS(stp->sd_ciputctrl, 3348 stp->sd_nciputctrl, 0); 3349 ASSERT(ciputctrl_cache != NULL); 3350 kmem_cache_free(ciputctrl_cache, stp->sd_ciputctrl); 3351 stp->sd_ciputctrl = NULL; 3352 stp->sd_nciputctrl = 0; 3353 } 3354 ASSERT(stp->sd_qhead == NULL); 3355 ASSERT(stp->sd_qtail == NULL); 3356 ASSERT(stp->sd_nqueues == 0); 3357 kmem_cache_free(stream_head_cache, stp); 3358 } 3359 3360 /* 3361 * Allocate a pair of queues and a syncq for the pair 3362 */ 3363 queue_t * 3364 allocq(void) 3365 { 3366 queinfo_t *qip; 3367 queue_t *qp, *wqp; 3368 syncq_t *sq; 3369 3370 qip = kmem_cache_alloc(queue_cache, KM_SLEEP); 3371 3372 qp = &qip->qu_rqueue; 3373 wqp = &qip->qu_wqueue; 3374 sq = &qip->qu_syncq; 3375 3376 qp->q_last = NULL; 3377 qp->q_next = NULL; 3378 qp->q_ptr = NULL; 3379 qp->q_flag = QUSE | QREADR; 3380 qp->q_bandp = NULL; 3381 qp->q_stream = NULL; 3382 qp->q_syncq = sq; 3383 qp->q_nband = 0; 3384 qp->q_nfsrv = NULL; 3385 qp->q_draining = 0; 3386 qp->q_syncqmsgs = 0; 3387 qp->q_spri = 0; 3388 qp->q_qtstamp = 0; 3389 qp->q_sqtstamp = 0; 3390 qp->q_fp = NULL; 3391 3392 wqp->q_last = NULL; 3393 wqp->q_next = NULL; 3394 wqp->q_ptr = NULL; 3395 wqp->q_flag = QUSE; 3396 wqp->q_bandp = NULL; 3397 wqp->q_stream = NULL; 3398 wqp->q_syncq = sq; 3399 wqp->q_nband = 0; 3400 wqp->q_nfsrv = NULL; 3401 wqp->q_draining = 0; 3402 wqp->q_syncqmsgs = 0; 3403 wqp->q_qtstamp = 0; 3404 wqp->q_sqtstamp = 0; 3405 wqp->q_spri = 0; 3406 3407 sq->sq_count = 0; 3408 sq->sq_rmqcount = 0; 3409 sq->sq_flags = 0; 3410 sq->sq_type = 0; 3411 sq->sq_callbflags = 0; 3412 sq->sq_cancelid = 0; 3413 sq->sq_ciputctrl = NULL; 3414 sq->sq_nciputctrl = 0; 3415 sq->sq_needexcl = 0; 3416 sq->sq_svcflags = 0; 3417 3418 return (qp); 3419 } 3420 3421 /* 3422 * Free a pair of queues and the "attached" syncq. 3423 * Discard any messages left on the syncq(s), remove the syncq(s) from the 3424 * outer perimeter, and free the syncq(s) if they are not the "attached" syncq. 3425 */ 3426 void 3427 freeq(queue_t *qp) 3428 { 3429 qband_t *qbp, *nqbp; 3430 syncq_t *sq, *outer; 3431 queue_t *wqp = _WR(qp); 3432 3433 ASSERT(qp->q_flag & QREADR); 3434 3435 /* 3436 * If a previously dispatched taskq job is scheduled to run 3437 * sync_service() or a service routine is scheduled for the 3438 * queues about to be freed, wait here until all service is 3439 * done on the queue and all associated queues and syncqs. 3440 */ 3441 wait_svc(qp); 3442 3443 (void) flush_syncq(qp->q_syncq, qp); 3444 (void) flush_syncq(wqp->q_syncq, wqp); 3445 ASSERT(qp->q_syncqmsgs == 0 && wqp->q_syncqmsgs == 0); 3446 3447 /* 3448 * Flush the queues before q_next is set to NULL This is needed 3449 * in order to backenable any downstream queue before we go away. 3450 * Note: we are already removed from the stream so that the 3451 * backenabling will not cause any messages to be delivered to our 3452 * put procedures. 3453 */ 3454 flushq(qp, FLUSHALL); 3455 flushq(wqp, FLUSHALL); 3456 3457 /* Tidy up - removeq only does a half-remove from stream */ 3458 qp->q_next = wqp->q_next = NULL; 3459 ASSERT(!(qp->q_flag & QENAB)); 3460 ASSERT(!(wqp->q_flag & QENAB)); 3461 3462 outer = qp->q_syncq->sq_outer; 3463 if (outer != NULL) { 3464 outer_remove(outer, qp->q_syncq); 3465 if (wqp->q_syncq != qp->q_syncq) 3466 outer_remove(outer, wqp->q_syncq); 3467 } 3468 /* 3469 * Free any syncqs that are outside what allocq returned. 3470 */ 3471 if (qp->q_syncq != SQ(qp) && !(qp->q_flag & QPERMOD)) 3472 free_syncq(qp->q_syncq); 3473 if (qp->q_syncq != wqp->q_syncq && wqp->q_syncq != SQ(qp)) 3474 free_syncq(wqp->q_syncq); 3475 3476 ASSERT((qp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); 3477 ASSERT((wqp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); 3478 ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); 3479 ASSERT(MUTEX_NOT_HELD(QLOCK(wqp))); 3480 sq = SQ(qp); 3481 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 3482 ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); 3483 ASSERT(sq->sq_outer == NULL); 3484 ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); 3485 ASSERT(sq->sq_callbpend == NULL); 3486 ASSERT(sq->sq_needexcl == 0); 3487 3488 if (sq->sq_ciputctrl != NULL) { 3489 ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); 3490 SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, 3491 sq->sq_nciputctrl, 0); 3492 ASSERT(ciputctrl_cache != NULL); 3493 kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); 3494 sq->sq_ciputctrl = NULL; 3495 sq->sq_nciputctrl = 0; 3496 } 3497 3498 ASSERT(qp->q_first == NULL && wqp->q_first == NULL); 3499 ASSERT(qp->q_count == 0 && wqp->q_count == 0); 3500 ASSERT(qp->q_mblkcnt == 0 && wqp->q_mblkcnt == 0); 3501 3502 qp->q_flag &= ~QUSE; 3503 wqp->q_flag &= ~QUSE; 3504 3505 /* NOTE: Uncomment the assert below once bugid 1159635 is fixed. */ 3506 /* ASSERT((qp->q_flag & QWANTW) == 0 && (wqp->q_flag & QWANTW) == 0); */ 3507 3508 qbp = qp->q_bandp; 3509 while (qbp) { 3510 nqbp = qbp->qb_next; 3511 freeband(qbp); 3512 qbp = nqbp; 3513 } 3514 qbp = wqp->q_bandp; 3515 while (qbp) { 3516 nqbp = qbp->qb_next; 3517 freeband(qbp); 3518 qbp = nqbp; 3519 } 3520 kmem_cache_free(queue_cache, qp); 3521 } 3522 3523 /* 3524 * Allocate a qband structure. 3525 */ 3526 qband_t * 3527 allocband(void) 3528 { 3529 qband_t *qbp; 3530 3531 qbp = kmem_cache_alloc(qband_cache, KM_NOSLEEP); 3532 if (qbp == NULL) 3533 return (NULL); 3534 3535 qbp->qb_next = NULL; 3536 qbp->qb_count = 0; 3537 qbp->qb_mblkcnt = 0; 3538 qbp->qb_first = NULL; 3539 qbp->qb_last = NULL; 3540 qbp->qb_flag = 0; 3541 3542 return (qbp); 3543 } 3544 3545 /* 3546 * Free a qband structure. 3547 */ 3548 void 3549 freeband(qband_t *qbp) 3550 { 3551 kmem_cache_free(qband_cache, qbp); 3552 } 3553 3554 /* 3555 * Just like putnextctl(9F), except that allocb_wait() is used. 3556 * 3557 * Consolidation Private, and of course only callable from the stream head or 3558 * routines that may block. 3559 */ 3560 int 3561 putnextctl_wait(queue_t *q, int type) 3562 { 3563 mblk_t *bp; 3564 int error; 3565 3566 if ((datamsg(type) && (type != M_DELAY)) || 3567 (bp = allocb_wait(0, BPRI_HI, 0, &error)) == NULL) 3568 return (0); 3569 3570 bp->b_datap->db_type = (unsigned char)type; 3571 putnext(q, bp); 3572 return (1); 3573 } 3574 3575 /* 3576 * Run any possible bufcalls. 3577 */ 3578 void 3579 runbufcalls(void) 3580 { 3581 strbufcall_t *bcp; 3582 3583 mutex_enter(&bcall_monitor); 3584 mutex_enter(&strbcall_lock); 3585 3586 if (strbcalls.bc_head) { 3587 size_t count; 3588 int nevent; 3589 3590 /* 3591 * count how many events are on the list 3592 * now so we can check to avoid looping 3593 * in low memory situations 3594 */ 3595 nevent = 0; 3596 for (bcp = strbcalls.bc_head; bcp; bcp = bcp->bc_next) 3597 nevent++; 3598 3599 /* 3600 * get estimate of available memory from kmem_avail(). 3601 * awake all bufcall functions waiting for 3602 * memory whose request could be satisfied 3603 * by 'count' memory and let 'em fight for it. 3604 */ 3605 count = kmem_avail(); 3606 while ((bcp = strbcalls.bc_head) != NULL && nevent) { 3607 STRSTAT(bufcalls); 3608 --nevent; 3609 if (bcp->bc_size <= count) { 3610 bcp->bc_executor = curthread; 3611 mutex_exit(&strbcall_lock); 3612 (*bcp->bc_func)(bcp->bc_arg); 3613 mutex_enter(&strbcall_lock); 3614 bcp->bc_executor = NULL; 3615 cv_broadcast(&bcall_cv); 3616 strbcalls.bc_head = bcp->bc_next; 3617 kmem_free(bcp, sizeof (strbufcall_t)); 3618 } else { 3619 /* 3620 * too big, try again later - note 3621 * that nevent was decremented above 3622 * so we won't retry this one on this 3623 * iteration of the loop 3624 */ 3625 if (bcp->bc_next != NULL) { 3626 strbcalls.bc_head = bcp->bc_next; 3627 bcp->bc_next = NULL; 3628 strbcalls.bc_tail->bc_next = bcp; 3629 strbcalls.bc_tail = bcp; 3630 } 3631 } 3632 } 3633 if (strbcalls.bc_head == NULL) 3634 strbcalls.bc_tail = NULL; 3635 } 3636 3637 mutex_exit(&strbcall_lock); 3638 mutex_exit(&bcall_monitor); 3639 } 3640 3641 3642 /* 3643 * Actually run queue's service routine. 3644 */ 3645 static void 3646 runservice(queue_t *q) 3647 { 3648 qband_t *qbp; 3649 3650 ASSERT(q->q_qinfo->qi_srvp); 3651 again: 3652 entersq(q->q_syncq, SQ_SVC); 3653 TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_START, 3654 "runservice starts:%p", q); 3655 3656 if (!(q->q_flag & QWCLOSE)) 3657 (*q->q_qinfo->qi_srvp)(q); 3658 3659 TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_END, 3660 "runservice ends:(%p)", q); 3661 3662 leavesq(q->q_syncq, SQ_SVC); 3663 3664 mutex_enter(QLOCK(q)); 3665 if (q->q_flag & QENAB) { 3666 q->q_flag &= ~QENAB; 3667 mutex_exit(QLOCK(q)); 3668 goto again; 3669 } 3670 q->q_flag &= ~QINSERVICE; 3671 q->q_flag &= ~QBACK; 3672 for (qbp = q->q_bandp; qbp; qbp = qbp->qb_next) 3673 qbp->qb_flag &= ~QB_BACK; 3674 /* 3675 * Wakeup thread waiting for the service procedure 3676 * to be run (strclose and qdetach). 3677 */ 3678 cv_broadcast(&q->q_wait); 3679 3680 mutex_exit(QLOCK(q)); 3681 } 3682 3683 /* 3684 * Background processing of bufcalls. 3685 */ 3686 void 3687 streams_bufcall_service(void) 3688 { 3689 callb_cpr_t cprinfo; 3690 3691 CALLB_CPR_INIT(&cprinfo, &strbcall_lock, callb_generic_cpr, 3692 "streams_bufcall_service"); 3693 3694 mutex_enter(&strbcall_lock); 3695 3696 for (;;) { 3697 if (strbcalls.bc_head != NULL && kmem_avail() > 0) { 3698 mutex_exit(&strbcall_lock); 3699 runbufcalls(); 3700 mutex_enter(&strbcall_lock); 3701 } 3702 if (strbcalls.bc_head != NULL) { 3703 STRSTAT(bcwaits); 3704 /* Wait for memory to become available */ 3705 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3706 (void) cv_reltimedwait(&memavail_cv, &strbcall_lock, 3707 SEC_TO_TICK(60), TR_CLOCK_TICK); 3708 CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); 3709 } 3710 3711 /* Wait for new work to arrive */ 3712 if (strbcalls.bc_head == NULL) { 3713 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3714 cv_wait(&strbcall_cv, &strbcall_lock); 3715 CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); 3716 } 3717 } 3718 } 3719 3720 /* 3721 * Background processing of streams background tasks which failed 3722 * taskq_dispatch. 3723 */ 3724 static void 3725 streams_qbkgrnd_service(void) 3726 { 3727 callb_cpr_t cprinfo; 3728 queue_t *q; 3729 3730 CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, 3731 "streams_bkgrnd_service"); 3732 3733 mutex_enter(&service_queue); 3734 3735 for (;;) { 3736 /* 3737 * Wait for work to arrive. 3738 */ 3739 while ((freebs_list == NULL) && (qhead == NULL)) { 3740 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3741 cv_wait(&services_to_run, &service_queue); 3742 CALLB_CPR_SAFE_END(&cprinfo, &service_queue); 3743 } 3744 /* 3745 * Handle all pending freebs requests to free memory. 3746 */ 3747 while (freebs_list != NULL) { 3748 mblk_t *mp = freebs_list; 3749 freebs_list = mp->b_next; 3750 mutex_exit(&service_queue); 3751 mblk_free(mp); 3752 mutex_enter(&service_queue); 3753 } 3754 /* 3755 * Run pending queues. 3756 */ 3757 while (qhead != NULL) { 3758 DQ(q, qhead, qtail, q_link); 3759 ASSERT(q != NULL); 3760 mutex_exit(&service_queue); 3761 queue_service(q); 3762 mutex_enter(&service_queue); 3763 } 3764 ASSERT(qhead == NULL && qtail == NULL); 3765 } 3766 } 3767 3768 /* 3769 * Background processing of streams background tasks which failed 3770 * taskq_dispatch. 3771 */ 3772 static void 3773 streams_sqbkgrnd_service(void) 3774 { 3775 callb_cpr_t cprinfo; 3776 syncq_t *sq; 3777 3778 CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, 3779 "streams_sqbkgrnd_service"); 3780 3781 mutex_enter(&service_queue); 3782 3783 for (;;) { 3784 /* 3785 * Wait for work to arrive. 3786 */ 3787 while (sqhead == NULL) { 3788 CALLB_CPR_SAFE_BEGIN(&cprinfo); 3789 cv_wait(&syncqs_to_run, &service_queue); 3790 CALLB_CPR_SAFE_END(&cprinfo, &service_queue); 3791 } 3792 3793 /* 3794 * Run pending syncqs. 3795 */ 3796 while (sqhead != NULL) { 3797 DQ(sq, sqhead, sqtail, sq_next); 3798 ASSERT(sq != NULL); 3799 ASSERT(sq->sq_svcflags & SQ_BGTHREAD); 3800 mutex_exit(&service_queue); 3801 syncq_service(sq); 3802 mutex_enter(&service_queue); 3803 } 3804 } 3805 } 3806 3807 /* 3808 * Disable the syncq and wait for background syncq processing to complete. 3809 * If the syncq is placed on the sqhead/sqtail queue, try to remove it from the 3810 * list. 3811 */ 3812 void 3813 wait_sq_svc(syncq_t *sq) 3814 { 3815 mutex_enter(SQLOCK(sq)); 3816 sq->sq_svcflags |= SQ_DISABLED; 3817 if (sq->sq_svcflags & SQ_BGTHREAD) { 3818 syncq_t *sq_chase; 3819 syncq_t *sq_curr; 3820 int removed; 3821 3822 ASSERT(sq->sq_servcount == 1); 3823 mutex_enter(&service_queue); 3824 RMQ(sq, sqhead, sqtail, sq_next, sq_chase, sq_curr, removed); 3825 mutex_exit(&service_queue); 3826 if (removed) { 3827 sq->sq_svcflags &= ~SQ_BGTHREAD; 3828 sq->sq_servcount = 0; 3829 STRSTAT(sqremoved); 3830 goto done; 3831 } 3832 } 3833 while (sq->sq_servcount != 0) { 3834 sq->sq_flags |= SQ_WANTWAKEUP; 3835 cv_wait(&sq->sq_wait, SQLOCK(sq)); 3836 } 3837 done: 3838 mutex_exit(SQLOCK(sq)); 3839 } 3840 3841 /* 3842 * Put a syncq on the list of syncq's to be serviced by the sqthread. 3843 * Add the argument to the end of the sqhead list and set the flag 3844 * indicating this syncq has been enabled. If it has already been 3845 * enabled, don't do anything. 3846 * This routine assumes that SQLOCK is held. 3847 * NOTE that the lock order is to have the SQLOCK first, 3848 * so if the service_syncq lock is held, we need to release it 3849 * before acquiring the SQLOCK (mostly relevant for the background 3850 * thread, and this seems to be common among the STREAMS global locks). 3851 * Note that the sq_svcflags are protected by the SQLOCK. 3852 */ 3853 void 3854 sqenable(syncq_t *sq) 3855 { 3856 /* 3857 * This is probably not important except for where I believe it 3858 * is being called. At that point, it should be held (and it 3859 * is a pain to release it just for this routine, so don't do 3860 * it). 3861 */ 3862 ASSERT(MUTEX_HELD(SQLOCK(sq))); 3863 3864 IMPLY(sq->sq_servcount == 0, sq->sq_next == NULL); 3865 IMPLY(sq->sq_next != NULL, sq->sq_svcflags & SQ_BGTHREAD); 3866 3867 /* 3868 * Do not put on list if background thread is scheduled or 3869 * syncq is disabled. 3870 */ 3871 if (sq->sq_svcflags & (SQ_DISABLED | SQ_BGTHREAD)) 3872 return; 3873 3874 /* 3875 * Check whether we should enable sq at all. 3876 * Non PERMOD syncqs may be drained by at most one thread. 3877 * PERMOD syncqs may be drained by several threads but we limit the 3878 * total amount to the lesser of 3879 * Number of queues on the squeue and 3880 * Number of CPUs. 3881 */ 3882 if (sq->sq_servcount != 0) { 3883 if (((sq->sq_type & SQ_PERMOD) == 0) || 3884 (sq->sq_servcount >= MIN(sq->sq_nqueues, ncpus_online))) { 3885 STRSTAT(sqtoomany); 3886 return; 3887 } 3888 } 3889 3890 sq->sq_tstamp = ddi_get_lbolt(); 3891 STRSTAT(sqenables); 3892 3893 /* Attempt a taskq dispatch */ 3894 sq->sq_servid = (void *)taskq_dispatch(streams_taskq, 3895 (task_func_t *)syncq_service, sq, TQ_NOSLEEP | TQ_NOQUEUE); 3896 if (sq->sq_servid != NULL) { 3897 sq->sq_servcount++; 3898 return; 3899 } 3900 3901 /* 3902 * This taskq dispatch failed, but a previous one may have succeeded. 3903 * Don't try to schedule on the background thread whilst there is 3904 * outstanding taskq processing. 3905 */ 3906 if (sq->sq_servcount != 0) 3907 return; 3908 3909 /* 3910 * System is low on resources and can't perform a non-sleeping 3911 * dispatch. Schedule the syncq for a background thread and mark the 3912 * syncq to avoid any further taskq dispatch attempts. 3913 */ 3914 mutex_enter(&service_queue); 3915 STRSTAT(taskqfails); 3916 ENQUEUE(sq, sqhead, sqtail, sq_next); 3917 sq->sq_svcflags |= SQ_BGTHREAD; 3918 sq->sq_servcount = 1; 3919 cv_signal(&syncqs_to_run); 3920 mutex_exit(&service_queue); 3921 } 3922 3923 /* 3924 * Note: fifo_close() depends on the mblk_t on the queue being freed 3925 * asynchronously. The asynchronous freeing of messages breaks the 3926 * recursive call chain of fifo_close() while there are I_SENDFD type of 3927 * messages referring to other file pointers on the queue. Then when 3928 * closing pipes it can avoid stack overflow in case of daisy-chained 3929 * pipes, and also avoid deadlock in case of fifonode_t pairs (which 3930 * share the same fifolock_t). 3931 * 3932 * No need to kpreempt_disable to access cpu_seqid. If we migrate and 3933 * the esb queue does not match the new CPU, that is OK. 3934 */ 3935 void 3936 freebs_enqueue(mblk_t *mp, dblk_t *dbp) 3937 { 3938 int qindex = CPU->cpu_seqid >> esbq_log2_cpus_per_q; 3939 esb_queue_t *eqp; 3940 3941 ASSERT(dbp->db_mblk == mp); 3942 ASSERT(qindex < esbq_nelem); 3943 3944 eqp = system_esbq_array; 3945 if (eqp != NULL) { 3946 eqp += qindex; 3947 } else { 3948 mutex_enter(&esbq_lock); 3949 if (kmem_ready && system_esbq_array == NULL) 3950 system_esbq_array = (esb_queue_t *)kmem_zalloc( 3951 esbq_nelem * sizeof (esb_queue_t), KM_NOSLEEP); 3952 mutex_exit(&esbq_lock); 3953 eqp = system_esbq_array; 3954 if (eqp != NULL) 3955 eqp += qindex; 3956 else 3957 eqp = &system_esbq; 3958 } 3959 3960 /* 3961 * Check data sanity. The dblock should have non-empty free function. 3962 * It is better to panic here then later when the dblock is freed 3963 * asynchronously when the context is lost. 3964 */ 3965 if (dbp->db_frtnp->free_func == NULL) { 3966 panic("freebs_enqueue: dblock %p has a NULL free callback", 3967 (void *)dbp); 3968 } 3969 3970 mutex_enter(&eqp->eq_lock); 3971 /* queue the new mblk on the esballoc queue */ 3972 if (eqp->eq_head == NULL) { 3973 eqp->eq_head = eqp->eq_tail = mp; 3974 } else { 3975 eqp->eq_tail->b_next = mp; 3976 eqp->eq_tail = mp; 3977 } 3978 eqp->eq_len++; 3979 3980 /* If we're the first thread to reach the threshold, process */ 3981 if (eqp->eq_len >= esbq_max_qlen && 3982 !(eqp->eq_flags & ESBQ_PROCESSING)) 3983 esballoc_process_queue(eqp); 3984 3985 esballoc_set_timer(eqp, esbq_timeout); 3986 mutex_exit(&eqp->eq_lock); 3987 } 3988 3989 static void 3990 esballoc_process_queue(esb_queue_t *eqp) 3991 { 3992 mblk_t *mp; 3993 3994 ASSERT(MUTEX_HELD(&eqp->eq_lock)); 3995 3996 eqp->eq_flags |= ESBQ_PROCESSING; 3997 3998 do { 3999 /* 4000 * Detach the message chain for processing. 4001 */ 4002 mp = eqp->eq_head; 4003 eqp->eq_tail->b_next = NULL; 4004 eqp->eq_head = eqp->eq_tail = NULL; 4005 eqp->eq_len = 0; 4006 mutex_exit(&eqp->eq_lock); 4007 4008 /* 4009 * Process the message chain. 4010 */ 4011 esballoc_enqueue_mblk(mp); 4012 mutex_enter(&eqp->eq_lock); 4013 } while ((eqp->eq_len >= esbq_max_qlen) && (eqp->eq_len > 0)); 4014 4015 eqp->eq_flags &= ~ESBQ_PROCESSING; 4016 } 4017 4018 /* 4019 * taskq callback routine to free esballoced mblk's 4020 */ 4021 static void 4022 esballoc_mblk_free(mblk_t *mp) 4023 { 4024 mblk_t *nextmp; 4025 4026 for (; mp != NULL; mp = nextmp) { 4027 nextmp = mp->b_next; 4028 mp->b_next = NULL; 4029 mblk_free(mp); 4030 } 4031 } 4032 4033 static void 4034 esballoc_enqueue_mblk(mblk_t *mp) 4035 { 4036 4037 if (taskq_dispatch(system_taskq, (task_func_t *)esballoc_mblk_free, mp, 4038 TQ_NOSLEEP) == TASKQID_INVALID) { 4039 mblk_t *first_mp = mp; 4040 /* 4041 * System is low on resources and can't perform a non-sleeping 4042 * dispatch. Schedule for a background thread. 4043 */ 4044 mutex_enter(&service_queue); 4045 STRSTAT(taskqfails); 4046 4047 while (mp->b_next != NULL) 4048 mp = mp->b_next; 4049 4050 mp->b_next = freebs_list; 4051 freebs_list = first_mp; 4052 cv_signal(&services_to_run); 4053 mutex_exit(&service_queue); 4054 } 4055 } 4056 4057 static void 4058 esballoc_timer(void *arg) 4059 { 4060 esb_queue_t *eqp = arg; 4061 4062 mutex_enter(&eqp->eq_lock); 4063 eqp->eq_flags &= ~ESBQ_TIMER; 4064 4065 if (!(eqp->eq_flags & ESBQ_PROCESSING) && 4066 eqp->eq_len > 0) 4067 esballoc_process_queue(eqp); 4068 4069 esballoc_set_timer(eqp, esbq_timeout); 4070 mutex_exit(&eqp->eq_lock); 4071 } 4072 4073 static void 4074 esballoc_set_timer(esb_queue_t *eqp, clock_t eq_timeout) 4075 { 4076 ASSERT(MUTEX_HELD(&eqp->eq_lock)); 4077 4078 if (eqp->eq_len > 0 && !(eqp->eq_flags & ESBQ_TIMER)) { 4079 (void) timeout(esballoc_timer, eqp, eq_timeout); 4080 eqp->eq_flags |= ESBQ_TIMER; 4081 } 4082 } 4083 4084 /* 4085 * Setup esbq array length based upon NCPU scaled by CPUs per 4086 * queue. Use static system_esbq until kmem_ready and we can 4087 * create an array in freebs_enqueue(). 4088 */ 4089 void 4090 esballoc_queue_init(void) 4091 { 4092 esbq_log2_cpus_per_q = highbit(esbq_cpus_per_q - 1); 4093 esbq_cpus_per_q = 1 << esbq_log2_cpus_per_q; 4094 esbq_nelem = howmany(NCPU, esbq_cpus_per_q); 4095 system_esbq.eq_len = 0; 4096 system_esbq.eq_head = system_esbq.eq_tail = NULL; 4097 system_esbq.eq_flags = 0; 4098 } 4099 4100 /* 4101 * Set the QBACK or QB_BACK flag in the given queue for 4102 * the given priority band. 4103 */ 4104 void 4105 setqback(queue_t *q, unsigned char pri) 4106 { 4107 int i; 4108 qband_t *qbp; 4109 qband_t **qbpp; 4110 4111 ASSERT(MUTEX_HELD(QLOCK(q))); 4112 if (pri != 0) { 4113 if (pri > q->q_nband) { 4114 qbpp = &q->q_bandp; 4115 while (*qbpp) 4116 qbpp = &(*qbpp)->qb_next; 4117 while (pri > q->q_nband) { 4118 if ((*qbpp = allocband()) == NULL) { 4119 cmn_err(CE_WARN, 4120 "setqback: can't allocate qband\n"); 4121 return; 4122 } 4123 (*qbpp)->qb_hiwat = q->q_hiwat; 4124 (*qbpp)->qb_lowat = q->q_lowat; 4125 q->q_nband++; 4126 qbpp = &(*qbpp)->qb_next; 4127 } 4128 } 4129 qbp = q->q_bandp; 4130 i = pri; 4131 while (--i) 4132 qbp = qbp->qb_next; 4133 qbp->qb_flag |= QB_BACK; 4134 } else { 4135 q->q_flag |= QBACK; 4136 } 4137 } 4138 4139 int 4140 strcopyin(void *from, void *to, size_t len, int copyflag) 4141 { 4142 if (copyflag & U_TO_K) { 4143 ASSERT((copyflag & K_TO_K) == 0); 4144 if (copyin(from, to, len)) 4145 return (EFAULT); 4146 } else { 4147 ASSERT(copyflag & K_TO_K); 4148 bcopy(from, to, len); 4149 } 4150 return (0); 4151 } 4152 4153 int 4154 strcopyout(void *from, void *to, size_t len, int copyflag) 4155 { 4156 if (copyflag & U_TO_K) { 4157 if (copyout(from, to, len)) 4158 return (EFAULT); 4159 } else { 4160 ASSERT(copyflag & K_TO_K); 4161 bcopy(from, to, len); 4162 } 4163 return (0); 4164 } 4165 4166 /* 4167 * strsignal_nolock() posts a signal to the process(es) at the stream head. 4168 * It assumes that the stream head lock is already held, whereas strsignal() 4169 * acquires the lock first. This routine was created because a few callers 4170 * release the stream head lock before calling only to re-acquire it after 4171 * it returns. 4172 */ 4173 void 4174 strsignal_nolock(stdata_t *stp, int sig, uchar_t band) 4175 { 4176 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4177 switch (sig) { 4178 case SIGPOLL: 4179 if (stp->sd_sigflags & S_MSG) 4180 strsendsig(stp->sd_siglist, S_MSG, band, 0); 4181 break; 4182 default: 4183 if (stp->sd_pgidp) 4184 pgsignal(stp->sd_pgidp, sig); 4185 break; 4186 } 4187 } 4188 4189 void 4190 strsignal(stdata_t *stp, int sig, int32_t band) 4191 { 4192 TRACE_3(TR_FAC_STREAMS_FR, TR_SENDSIG, 4193 "strsignal:%p, %X, %X", stp, sig, band); 4194 4195 mutex_enter(&stp->sd_lock); 4196 switch (sig) { 4197 case SIGPOLL: 4198 if (stp->sd_sigflags & S_MSG) 4199 strsendsig(stp->sd_siglist, S_MSG, (uchar_t)band, 0); 4200 break; 4201 4202 default: 4203 if (stp->sd_pgidp) { 4204 pgsignal(stp->sd_pgidp, sig); 4205 } 4206 break; 4207 } 4208 mutex_exit(&stp->sd_lock); 4209 } 4210 4211 void 4212 strhup(stdata_t *stp) 4213 { 4214 ASSERT(mutex_owned(&stp->sd_lock)); 4215 pollwakeup(&stp->sd_pollist, POLLHUP); 4216 if (stp->sd_sigflags & S_HANGUP) 4217 strsendsig(stp->sd_siglist, S_HANGUP, 0, 0); 4218 } 4219 4220 /* 4221 * Backenable the first queue upstream from `q' with a service procedure. 4222 */ 4223 void 4224 backenable(queue_t *q, uchar_t pri) 4225 { 4226 queue_t *nq; 4227 4228 /* 4229 * Our presence might not prevent other modules in our own 4230 * stream from popping/pushing since the caller of getq might not 4231 * have a claim on the queue (some drivers do a getq on somebody 4232 * else's queue - they know that the queue itself is not going away 4233 * but the framework has to guarantee q_next in that stream). 4234 */ 4235 claimstr(q); 4236 4237 /* Find nearest back queue with service proc */ 4238 for (nq = backq(q); nq && !nq->q_qinfo->qi_srvp; nq = backq(nq)) { 4239 ASSERT(STRMATED(q->q_stream) || STREAM(q) == STREAM(nq)); 4240 } 4241 4242 if (nq) { 4243 kthread_t *freezer; 4244 /* 4245 * backenable can be called either with no locks held 4246 * or with the stream frozen (the latter occurs when a module 4247 * calls rmvq with the stream frozen). If the stream is frozen 4248 * by the caller the caller will hold all qlocks in the stream. 4249 * Note that a frozen stream doesn't freeze a mated stream, 4250 * so we explicitly check for that. 4251 */ 4252 freezer = STREAM(q)->sd_freezer; 4253 if (freezer != curthread || STREAM(q) != STREAM(nq)) { 4254 mutex_enter(QLOCK(nq)); 4255 } 4256 #ifdef DEBUG 4257 else { 4258 ASSERT(frozenstr(q)); 4259 ASSERT(MUTEX_HELD(QLOCK(q))); 4260 ASSERT(MUTEX_HELD(QLOCK(nq))); 4261 } 4262 #endif 4263 setqback(nq, pri); 4264 qenable_locked(nq); 4265 if (freezer != curthread || STREAM(q) != STREAM(nq)) 4266 mutex_exit(QLOCK(nq)); 4267 } 4268 releasestr(q); 4269 } 4270 4271 /* 4272 * Return the appropriate errno when one of flags_to_check is set 4273 * in sd_flags. Uses the exported error routines if they are set. 4274 * Will return 0 if non error is set (or if the exported error routines 4275 * do not return an error). 4276 * 4277 * If there is both a read and write error to check, we prefer the read error. 4278 * Also, give preference to recorded errno's over the error functions. 4279 * The flags that are handled are: 4280 * STPLEX return EINVAL 4281 * STRDERR return sd_rerror (and clear if STRDERRNONPERSIST) 4282 * STWRERR return sd_werror (and clear if STWRERRNONPERSIST) 4283 * STRHUP return sd_werror 4284 * 4285 * If the caller indicates that the operation is a peek, a nonpersistent error 4286 * is not cleared. 4287 */ 4288 int 4289 strgeterr(stdata_t *stp, int32_t flags_to_check, int ispeek) 4290 { 4291 int32_t sd_flag = stp->sd_flag & flags_to_check; 4292 int error = 0; 4293 4294 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4295 ASSERT((flags_to_check & ~(STRDERR|STWRERR|STRHUP|STPLEX)) == 0); 4296 if (sd_flag & STPLEX) 4297 error = EINVAL; 4298 else if (sd_flag & STRDERR) { 4299 error = stp->sd_rerror; 4300 if ((stp->sd_flag & STRDERRNONPERSIST) && !ispeek) { 4301 /* 4302 * Read errors are non-persistent i.e. discarded once 4303 * returned to a non-peeking caller, 4304 */ 4305 stp->sd_rerror = 0; 4306 stp->sd_flag &= ~STRDERR; 4307 } 4308 if (error == 0 && stp->sd_rderrfunc != NULL) { 4309 int clearerr = 0; 4310 4311 error = (*stp->sd_rderrfunc)(stp->sd_vnode, ispeek, 4312 &clearerr); 4313 if (clearerr) { 4314 stp->sd_flag &= ~STRDERR; 4315 stp->sd_rderrfunc = NULL; 4316 } 4317 } 4318 } else if (sd_flag & STWRERR) { 4319 error = stp->sd_werror; 4320 if ((stp->sd_flag & STWRERRNONPERSIST) && !ispeek) { 4321 /* 4322 * Write errors are non-persistent i.e. discarded once 4323 * returned to a non-peeking caller, 4324 */ 4325 stp->sd_werror = 0; 4326 stp->sd_flag &= ~STWRERR; 4327 } 4328 if (error == 0 && stp->sd_wrerrfunc != NULL) { 4329 int clearerr = 0; 4330 4331 error = (*stp->sd_wrerrfunc)(stp->sd_vnode, ispeek, 4332 &clearerr); 4333 if (clearerr) { 4334 stp->sd_flag &= ~STWRERR; 4335 stp->sd_wrerrfunc = NULL; 4336 } 4337 } 4338 } else if (sd_flag & STRHUP) { 4339 /* sd_werror set when STRHUP */ 4340 error = stp->sd_werror; 4341 } 4342 return (error); 4343 } 4344 4345 4346 /* 4347 * Single-thread open/close/push/pop 4348 * for twisted streams also 4349 */ 4350 int 4351 strstartplumb(stdata_t *stp, int flag, int cmd) 4352 { 4353 int waited = 1; 4354 int error = 0; 4355 4356 if (STRMATED(stp)) { 4357 struct stdata *stmatep = stp->sd_mate; 4358 4359 STRLOCKMATES(stp); 4360 while (waited) { 4361 waited = 0; 4362 while (stmatep->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4363 if ((cmd == I_POP) && 4364 (flag & (FNDELAY|FNONBLOCK))) { 4365 STRUNLOCKMATES(stp); 4366 return (EAGAIN); 4367 } 4368 waited = 1; 4369 mutex_exit(&stp->sd_lock); 4370 if (!cv_wait_sig(&stmatep->sd_monitor, 4371 &stmatep->sd_lock)) { 4372 mutex_exit(&stmatep->sd_lock); 4373 return (EINTR); 4374 } 4375 mutex_exit(&stmatep->sd_lock); 4376 STRLOCKMATES(stp); 4377 } 4378 while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4379 if ((cmd == I_POP) && 4380 (flag & (FNDELAY|FNONBLOCK))) { 4381 STRUNLOCKMATES(stp); 4382 return (EAGAIN); 4383 } 4384 waited = 1; 4385 mutex_exit(&stmatep->sd_lock); 4386 if (!cv_wait_sig(&stp->sd_monitor, 4387 &stp->sd_lock)) { 4388 mutex_exit(&stp->sd_lock); 4389 return (EINTR); 4390 } 4391 mutex_exit(&stp->sd_lock); 4392 STRLOCKMATES(stp); 4393 } 4394 if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { 4395 error = strgeterr(stp, 4396 STRDERR|STWRERR|STRHUP|STPLEX, 0); 4397 if (error != 0) { 4398 STRUNLOCKMATES(stp); 4399 return (error); 4400 } 4401 } 4402 } 4403 stp->sd_flag |= STRPLUMB; 4404 STRUNLOCKMATES(stp); 4405 } else { 4406 mutex_enter(&stp->sd_lock); 4407 while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { 4408 if (((cmd == I_POP) || (cmd == _I_REMOVE)) && 4409 (flag & (FNDELAY|FNONBLOCK))) { 4410 mutex_exit(&stp->sd_lock); 4411 return (EAGAIN); 4412 } 4413 if (!cv_wait_sig(&stp->sd_monitor, &stp->sd_lock)) { 4414 mutex_exit(&stp->sd_lock); 4415 return (EINTR); 4416 } 4417 if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { 4418 error = strgeterr(stp, 4419 STRDERR|STWRERR|STRHUP|STPLEX, 0); 4420 if (error != 0) { 4421 mutex_exit(&stp->sd_lock); 4422 return (error); 4423 } 4424 } 4425 } 4426 stp->sd_flag |= STRPLUMB; 4427 mutex_exit(&stp->sd_lock); 4428 } 4429 return (0); 4430 } 4431 4432 /* 4433 * Complete the plumbing operation associated with stream `stp'. 4434 */ 4435 void 4436 strendplumb(stdata_t *stp) 4437 { 4438 ASSERT(MUTEX_HELD(&stp->sd_lock)); 4439 ASSERT(stp->sd_flag & STRPLUMB); 4440 stp->sd_flag &= ~STRPLUMB; 4441 cv_broadcast(&stp->sd_monitor); 4442 } 4443 4444 /* 4445 * This describes how the STREAMS framework handles synchronization 4446 * during open/push and close/pop. 4447 * The key interfaces for open and close are qprocson and qprocsoff, 4448 * respectively. While the close case in general is harder both open 4449 * have close have significant similarities. 4450 * 4451 * During close the STREAMS framework has to both ensure that there 4452 * are no stale references to the queue pair (and syncq) that 4453 * are being closed and also provide the guarantees that are documented 4454 * in qprocsoff(9F). 4455 * If there are stale references to the queue that is closing it can 4456 * result in kernel memory corruption or kernel panics. 4457 * 4458 * Note that is it up to the module/driver to ensure that it itself 4459 * does not have any stale references to the closing queues once its close 4460 * routine returns. This includes: 4461 * - Cancelling any timeout/bufcall/qtimeout/qbufcall callback routines 4462 * associated with the queues. For timeout and bufcall callbacks the 4463 * module/driver also has to ensure (or wait for) any callbacks that 4464 * are in progress. 4465 * - If the module/driver is using esballoc it has to ensure that any 4466 * esballoc free functions do not refer to a queue that has closed. 4467 * (Note that in general the close routine can not wait for the esballoc'ed 4468 * messages to be freed since that can cause a deadlock.) 4469 * - Cancelling any interrupts that refer to the closing queues and 4470 * also ensuring that there are no interrupts in progress that will 4471 * refer to the closing queues once the close routine returns. 4472 * - For multiplexors removing any driver global state that refers to 4473 * the closing queue and also ensuring that there are no threads in 4474 * the multiplexor that has picked up a queue pointer but not yet 4475 * finished using it. 4476 * 4477 * In addition, a driver/module can only reference the q_next pointer 4478 * in its open, close, put, or service procedures or in a 4479 * qtimeout/qbufcall callback procedure executing "on" the correct 4480 * stream. Thus it can not reference the q_next pointer in an interrupt 4481 * routine or a timeout, bufcall or esballoc callback routine. Likewise 4482 * it can not reference q_next of a different queue e.g. in a mux that 4483 * passes messages from one queues put/service procedure to another queue. 4484 * In all the cases when the driver/module can not access the q_next 4485 * field it must use the *next* versions e.g. canputnext instead of 4486 * canput(q->q_next) and putnextctl instead of putctl(q->q_next, ...). 4487 * 4488 * 4489 * Assuming that the driver/module conforms to the above constraints 4490 * the STREAMS framework has to avoid stale references to q_next for all 4491 * the framework internal cases which include (but are not limited to): 4492 * - Threads in canput/canputnext/backenable and elsewhere that are 4493 * walking q_next. 4494 * - Messages on a syncq that have a reference to the queue through b_queue. 4495 * - Messages on an outer perimeter (syncq) that have a reference to the 4496 * queue through b_queue. 4497 * - Threads that use q_nfsrv (e.g. canput) to find a queue. 4498 * Note that only canput and bcanput use q_nfsrv without any locking. 4499 * 4500 * The STREAMS framework providing the qprocsoff(9F) guarantees means that 4501 * after qprocsoff returns, the framework has to ensure that no threads can 4502 * enter the put or service routines for the closing read or write-side queue. 4503 * In addition to preventing "direct" entry into the put procedures 4504 * the framework also has to prevent messages being drained from 4505 * the syncq or the outer perimeter. 4506 * XXX Note that currently qdetach does relies on D_MTOCEXCL as the only 4507 * mechanism to prevent qwriter(PERIM_OUTER) from running after 4508 * qprocsoff has returned. 4509 * Note that if a module/driver uses put(9F) on one of its own queues 4510 * it is up to the module/driver to ensure that the put() doesn't 4511 * get called when the queue is closing. 4512 * 4513 * 4514 * The framework aspects of the above "contract" is implemented by 4515 * qprocsoff, removeq, and strlock: 4516 * - qprocsoff (disable_svc) sets QWCLOSE to prevent runservice from 4517 * entering the service procedures. 4518 * - strlock acquires the sd_lock and sd_reflock to prevent putnext, 4519 * canputnext, backenable etc from dereferencing the q_next that will 4520 * soon change. 4521 * - strlock waits for sd_refcnt to be zero to wait for e.g. any canputnext 4522 * or other q_next walker that uses claimstr/releasestr to finish. 4523 * - optionally for every syncq in the stream strlock acquires all the 4524 * sq_lock's and waits for all sq_counts to drop to a value that indicates 4525 * that no thread executes in the put or service procedures and that no 4526 * thread is draining into the module/driver. This ensures that no 4527 * open, close, put, service, or qtimeout/qbufcall callback procedure is 4528 * currently executing hence no such thread can end up with the old stale 4529 * q_next value and no canput/backenable can have the old stale 4530 * q_nfsrv/q_next. 4531 * - qdetach (wait_svc) makes sure that any scheduled or running threads 4532 * have either finished or observed the QWCLOSE flag and gone away. 4533 */ 4534 4535 4536 /* 4537 * Get all the locks necessary to change q_next. 4538 * 4539 * Wait for sd_refcnt to reach 0 and, if sqlist is present, wait for the 4540 * sq_count of each syncq in the list to drop to sq_rmqcount, indicating that 4541 * the only threads inside the syncq are threads currently calling removeq(). 4542 * Since threads calling removeq() are in the process of removing their queues 4543 * from the stream, we do not need to worry about them accessing a stale q_next 4544 * pointer and thus we do not need to wait for them to exit (in fact, waiting 4545 * for them can cause deadlock). 4546 * 4547 * This routine is subject to starvation since it does not set any flag to 4548 * prevent threads from entering a module in the stream (i.e. sq_count can 4549 * increase on some syncq while it is waiting on some other syncq). 4550 * 4551 * Assumes that only one thread attempts to call strlock for a given 4552 * stream. If this is not the case the two threads would deadlock. 4553 * This assumption is guaranteed since strlock is only called by insertq 4554 * and removeq and streams plumbing changes are single-threaded for 4555 * a given stream using the STWOPEN, STRCLOSE, and STRPLUMB flags. 4556 * 4557 * For pipes, it is not difficult to atomically designate a pair of streams 4558 * to be mated. Once mated atomically by the framework the twisted pair remain 4559 * configured that way until dismantled atomically by the framework. 4560 * When plumbing takes place on a twisted stream it is necessary to ensure that 4561 * this operation is done exclusively on the twisted stream since two such 4562 * operations, each initiated on different ends of the pipe will deadlock 4563 * waiting for each other to complete. 4564 * 4565 * On entry, no locks should be held. 4566 * The locks acquired and held by strlock depends on a few factors. 4567 * - If sqlist is non-NULL all the syncq locks in the sqlist will be acquired 4568 * and held on exit and all sq_count are at an acceptable level. 4569 * - In all cases, sd_lock and sd_reflock are acquired and held on exit with 4570 * sd_refcnt being zero. 4571 */ 4572 4573 static void 4574 strlock(struct stdata *stp, sqlist_t *sqlist) 4575 { 4576 syncql_t *sql, *sql2; 4577 retry: 4578 /* 4579 * Wait for any claimstr to go away. 4580 */ 4581 if (STRMATED(stp)) { 4582 struct stdata *stp1, *stp2; 4583 4584 STRLOCKMATES(stp); 4585 /* 4586 * Note that the selection of locking order is not 4587 * important, just that they are always acquired in 4588 * the same order. To assure this, we choose this 4589 * order based on the value of the pointer, and since 4590 * the pointer will not change for the life of this 4591 * pair, we will always grab the locks in the same 4592 * order (and hence, prevent deadlocks). 4593 */ 4594 if (&(stp->sd_lock) > &((stp->sd_mate)->sd_lock)) { 4595 stp1 = stp; 4596 stp2 = stp->sd_mate; 4597 } else { 4598 stp2 = stp; 4599 stp1 = stp->sd_mate; 4600 } 4601 mutex_enter(&stp1->sd_reflock); 4602 if (stp1->sd_refcnt > 0) { 4603 STRUNLOCKMATES(stp); 4604 cv_wait(&stp1->sd_refmonitor, &stp1->sd_reflock); 4605 mutex_exit(&stp1->sd_reflock); 4606 goto retry; 4607 } 4608 mutex_enter(&stp2->sd_reflock); 4609 if (stp2->sd_refcnt > 0) { 4610 STRUNLOCKMATES(stp); 4611 mutex_exit(&stp1->sd_reflock); 4612 cv_wait(&stp2->sd_refmonitor, &stp2->sd_reflock); 4613 mutex_exit(&stp2->sd_reflock); 4614 goto retry; 4615 } 4616 STREAM_PUTLOCKS_ENTER(stp1); 4617 STREAM_PUTLOCKS_ENTER(stp2); 4618 } else { 4619 mutex_enter(&stp->sd_lock); 4620 mutex_enter(&stp->sd_reflock); 4621 while (stp->sd_refcnt > 0) { 4622 mutex_exit(&stp->sd_lock); 4623 cv_wait(&stp->sd_refmonitor, &stp->sd_reflock); 4624 if (mutex_tryenter(&stp->sd_lock) == 0) { 4625 mutex_exit(&stp->sd_reflock); 4626 mutex_enter(&stp->sd_lock); 4627 mutex_enter(&stp->sd_reflock); 4628 } 4629 } 4630 STREAM_PUTLOCKS_ENTER(stp); 4631 } 4632 4633 if (sqlist == NULL) 4634 return; 4635 4636 for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { 4637 syncq_t *sq = sql->sql_sq; 4638 uint16_t count; 4639 4640 mutex_enter(SQLOCK(sq)); 4641 count = sq->sq_count; 4642 ASSERT(sq->sq_rmqcount <= count); 4643 SQ_PUTLOCKS_ENTER(sq); 4644 SUM_SQ_PUTCOUNTS(sq, count); 4645 if (count == sq->sq_rmqcount) 4646 continue; 4647 4648 /* Failed - drop all locks that we have acquired so far */ 4649 if (STRMATED(stp)) { 4650 STREAM_PUTLOCKS_EXIT(stp); 4651 STREAM_PUTLOCKS_EXIT(stp->sd_mate); 4652 STRUNLOCKMATES(stp); 4653 mutex_exit(&stp->sd_reflock); 4654 mutex_exit(&stp->sd_mate->sd_reflock); 4655 } else { 4656 STREAM_PUTLOCKS_EXIT(stp); 4657 mutex_exit(&stp->sd_lock); 4658 mutex_exit(&stp->sd_reflock); 4659 } 4660 for (sql2 = sqlist->sqlist_head; sql2 != sql; 4661 sql2 = sql2->sql_next) { 4662 SQ_PUTLOCKS_EXIT(sql2->sql_sq); 4663 mutex_exit(SQLOCK(sql2->sql_sq)); 4664 } 4665 4666 /* 4667 * The wait loop below may starve when there are many threads 4668 * claiming the syncq. This is especially a problem with permod 4669 * syncqs (IP). To lessen the impact of the problem we increment 4670 * sq_needexcl and clear fastbits so that putnexts will slow 4671 * down and call sqenable instead of draining right away. 4672 */ 4673 sq->sq_needexcl++; 4674 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 4675 while (count > sq->sq_rmqcount) { 4676 sq->sq_flags |= SQ_WANTWAKEUP; 4677 SQ_PUTLOCKS_EXIT(sq); 4678 cv_wait(&sq->sq_wait, SQLOCK(sq)); 4679 count = sq->sq_count; 4680 SQ_PUTLOCKS_ENTER(sq); 4681 SUM_SQ_PUTCOUNTS(sq, count); 4682 } 4683 sq->sq_needexcl--; 4684 if (sq->sq_needexcl == 0) 4685 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 4686 SQ_PUTLOCKS_EXIT(sq); 4687 ASSERT(count == sq->sq_rmqcount); 4688 mutex_exit(SQLOCK(sq)); 4689 goto retry; 4690 } 4691 } 4692 4693 /* 4694 * Drop all the locks that strlock acquired. 4695 */ 4696 static void 4697 strunlock(struct stdata *stp, sqlist_t *sqlist) 4698 { 4699 syncql_t *sql; 4700 4701 if (STRMATED(stp)) { 4702 STREAM_PUTLOCKS_EXIT(stp); 4703 STREAM_PUTLOCKS_EXIT(stp->sd_mate); 4704 STRUNLOCKMATES(stp); 4705 mutex_exit(&stp->sd_reflock); 4706 mutex_exit(&stp->sd_mate->sd_reflock); 4707 } else { 4708 STREAM_PUTLOCKS_EXIT(stp); 4709 mutex_exit(&stp->sd_lock); 4710 mutex_exit(&stp->sd_reflock); 4711 } 4712 4713 if (sqlist == NULL) 4714 return; 4715 4716 for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { 4717 SQ_PUTLOCKS_EXIT(sql->sql_sq); 4718 mutex_exit(SQLOCK(sql->sql_sq)); 4719 } 4720 } 4721 4722 /* 4723 * When the module has service procedure, we need check if the next 4724 * module which has service procedure is in flow control to trigger 4725 * the backenable. 4726 */ 4727 static void 4728 backenable_insertedq(queue_t *q) 4729 { 4730 qband_t *qbp; 4731 4732 claimstr(q); 4733 if (q->q_qinfo->qi_srvp != NULL && q->q_next != NULL) { 4734 if (q->q_next->q_nfsrv->q_flag & QWANTW) 4735 backenable(q, 0); 4736 4737 qbp = q->q_next->q_nfsrv->q_bandp; 4738 for (; qbp != NULL; qbp = qbp->qb_next) 4739 if ((qbp->qb_flag & QB_WANTW) && qbp->qb_first != NULL) 4740 backenable(q, qbp->qb_first->b_band); 4741 } 4742 releasestr(q); 4743 } 4744 4745 /* 4746 * Given two read queues, insert a new single one after another. 4747 * 4748 * This routine acquires all the necessary locks in order to change 4749 * q_next and related pointer using strlock(). 4750 * It depends on the stream head ensuring that there are no concurrent 4751 * insertq or removeq on the same stream. The stream head ensures this 4752 * using the flags STWOPEN, STRCLOSE, and STRPLUMB. 4753 * 4754 * Note that no syncq locks are held during the q_next change. This is 4755 * applied to all streams since, unlike removeq, there is no problem of stale 4756 * pointers when adding a module to the stream. Thus drivers/modules that do a 4757 * canput(rq->q_next) would never get a closed/freed queue pointer even if we 4758 * applied this optimization to all streams. 4759 */ 4760 void 4761 insertq(struct stdata *stp, queue_t *new) 4762 { 4763 queue_t *after; 4764 queue_t *wafter; 4765 queue_t *wnew = _WR(new); 4766 boolean_t have_fifo = B_FALSE; 4767 4768 if (new->q_flag & _QINSERTING) { 4769 ASSERT(stp->sd_vnode->v_type != VFIFO); 4770 after = new->q_next; 4771 wafter = _WR(new->q_next); 4772 } else { 4773 after = _RD(stp->sd_wrq); 4774 wafter = stp->sd_wrq; 4775 } 4776 4777 TRACE_2(TR_FAC_STREAMS_FR, TR_INSERTQ, 4778 "insertq:%p, %p", after, new); 4779 ASSERT(after->q_flag & QREADR); 4780 ASSERT(new->q_flag & QREADR); 4781 4782 strlock(stp, NULL); 4783 4784 /* Do we have a FIFO? */ 4785 if (wafter->q_next == after) { 4786 have_fifo = B_TRUE; 4787 wnew->q_next = new; 4788 } else { 4789 wnew->q_next = wafter->q_next; 4790 } 4791 new->q_next = after; 4792 4793 set_nfsrv_ptr(new, wnew, after, wafter); 4794 /* 4795 * set_nfsrv_ptr() needs to know if this is an insertion or not, 4796 * so only reset this flag after calling it. 4797 */ 4798 new->q_flag &= ~_QINSERTING; 4799 4800 if (have_fifo) { 4801 wafter->q_next = wnew; 4802 } else { 4803 if (wafter->q_next) 4804 _OTHERQ(wafter->q_next)->q_next = new; 4805 wafter->q_next = wnew; 4806 } 4807 4808 set_qend(new); 4809 /* The QEND flag might have to be updated for the upstream guy */ 4810 set_qend(after); 4811 4812 ASSERT(_SAMESTR(new) == O_SAMESTR(new)); 4813 ASSERT(_SAMESTR(wnew) == O_SAMESTR(wnew)); 4814 ASSERT(_SAMESTR(after) == O_SAMESTR(after)); 4815 ASSERT(_SAMESTR(wafter) == O_SAMESTR(wafter)); 4816 strsetuio(stp); 4817 4818 /* 4819 * If this was a module insertion, bump the push count. 4820 */ 4821 if (!(new->q_flag & QISDRV)) 4822 stp->sd_pushcnt++; 4823 4824 strunlock(stp, NULL); 4825 4826 /* check if the write Q needs backenable */ 4827 backenable_insertedq(wnew); 4828 4829 /* check if the read Q needs backenable */ 4830 backenable_insertedq(new); 4831 } 4832 4833 /* 4834 * Given a read queue, unlink it from any neighbors. 4835 * 4836 * This routine acquires all the necessary locks in order to 4837 * change q_next and related pointers and also guard against 4838 * stale references (e.g. through q_next) to the queue that 4839 * is being removed. It also plays part of the role in ensuring 4840 * that the module's/driver's put procedure doesn't get called 4841 * after qprocsoff returns. 4842 * 4843 * Removeq depends on the stream head ensuring that there are 4844 * no concurrent insertq or removeq on the same stream. The 4845 * stream head ensures this using the flags STWOPEN, STRCLOSE and 4846 * STRPLUMB. 4847 * 4848 * The set of locks needed to remove the queue is different in 4849 * different cases: 4850 * 4851 * Acquire sd_lock, sd_reflock, and all the syncq locks in the stream after 4852 * waiting for the syncq reference count to drop to 0 indicating that no 4853 * non-close threads are present anywhere in the stream. This ensures that any 4854 * module/driver can reference q_next in its open, close, put, or service 4855 * procedures. 4856 * 4857 * The sq_rmqcount counter tracks the number of threads inside removeq(). 4858 * strlock() ensures that there is either no threads executing inside perimeter 4859 * or there is only a thread calling qprocsoff(). 4860 * 4861 * strlock() compares the value of sq_count with the number of threads inside 4862 * removeq() and waits until sq_count is equal to sq_rmqcount. We need to wakeup 4863 * any threads waiting in strlock() when the sq_rmqcount increases. 4864 */ 4865 4866 void 4867 removeq(queue_t *qp) 4868 { 4869 queue_t *wqp = _WR(qp); 4870 struct stdata *stp = STREAM(qp); 4871 sqlist_t *sqlist = NULL; 4872 boolean_t isdriver; 4873 int moved; 4874 syncq_t *sq = qp->q_syncq; 4875 syncq_t *wsq = wqp->q_syncq; 4876 4877 ASSERT(stp); 4878 4879 TRACE_2(TR_FAC_STREAMS_FR, TR_REMOVEQ, 4880 "removeq:%p %p", qp, wqp); 4881 ASSERT(qp->q_flag&QREADR); 4882 4883 /* 4884 * For queues using Synchronous streams, we must wait for all threads in 4885 * rwnext() to drain out before proceeding. 4886 */ 4887 if (qp->q_flag & QSYNCSTR) { 4888 /* First, we need wakeup any threads blocked in rwnext() */ 4889 mutex_enter(SQLOCK(sq)); 4890 if (sq->sq_flags & SQ_WANTWAKEUP) { 4891 sq->sq_flags &= ~SQ_WANTWAKEUP; 4892 cv_broadcast(&sq->sq_wait); 4893 } 4894 mutex_exit(SQLOCK(sq)); 4895 4896 if (wsq != sq) { 4897 mutex_enter(SQLOCK(wsq)); 4898 if (wsq->sq_flags & SQ_WANTWAKEUP) { 4899 wsq->sq_flags &= ~SQ_WANTWAKEUP; 4900 cv_broadcast(&wsq->sq_wait); 4901 } 4902 mutex_exit(SQLOCK(wsq)); 4903 } 4904 4905 mutex_enter(QLOCK(qp)); 4906 while (qp->q_rwcnt > 0) { 4907 qp->q_flag |= QWANTRMQSYNC; 4908 cv_wait(&qp->q_wait, QLOCK(qp)); 4909 } 4910 mutex_exit(QLOCK(qp)); 4911 4912 mutex_enter(QLOCK(wqp)); 4913 while (wqp->q_rwcnt > 0) { 4914 wqp->q_flag |= QWANTRMQSYNC; 4915 cv_wait(&wqp->q_wait, QLOCK(wqp)); 4916 } 4917 mutex_exit(QLOCK(wqp)); 4918 } 4919 4920 mutex_enter(SQLOCK(sq)); 4921 sq->sq_rmqcount++; 4922 if (sq->sq_flags & SQ_WANTWAKEUP) { 4923 sq->sq_flags &= ~SQ_WANTWAKEUP; 4924 cv_broadcast(&sq->sq_wait); 4925 } 4926 mutex_exit(SQLOCK(sq)); 4927 4928 isdriver = (qp->q_flag & QISDRV); 4929 4930 sqlist = sqlist_build(qp, stp, STRMATED(stp)); 4931 strlock(stp, sqlist); 4932 4933 reset_nfsrv_ptr(qp, wqp); 4934 4935 ASSERT(wqp->q_next == NULL || backq(qp)->q_next == qp); 4936 ASSERT(qp->q_next == NULL || backq(wqp)->q_next == wqp); 4937 /* Do we have a FIFO? */ 4938 if (wqp->q_next == qp) { 4939 stp->sd_wrq->q_next = _RD(stp->sd_wrq); 4940 } else { 4941 if (wqp->q_next) 4942 backq(qp)->q_next = qp->q_next; 4943 if (qp->q_next) 4944 backq(wqp)->q_next = wqp->q_next; 4945 } 4946 4947 /* The QEND flag might have to be updated for the upstream guy */ 4948 if (qp->q_next) 4949 set_qend(qp->q_next); 4950 4951 ASSERT(_SAMESTR(stp->sd_wrq) == O_SAMESTR(stp->sd_wrq)); 4952 ASSERT(_SAMESTR(_RD(stp->sd_wrq)) == O_SAMESTR(_RD(stp->sd_wrq))); 4953 4954 /* 4955 * Move any messages destined for the put procedures to the next 4956 * syncq in line. Otherwise free them. 4957 */ 4958 moved = 0; 4959 /* 4960 * Quick check to see whether there are any messages or events. 4961 */ 4962 if (qp->q_syncqmsgs != 0 || (qp->q_syncq->sq_flags & SQ_EVENTS)) 4963 moved += propagate_syncq(qp); 4964 if (wqp->q_syncqmsgs != 0 || 4965 (wqp->q_syncq->sq_flags & SQ_EVENTS)) 4966 moved += propagate_syncq(wqp); 4967 4968 strsetuio(stp); 4969 4970 /* 4971 * If this was a module removal, decrement the push count. 4972 */ 4973 if (!isdriver) 4974 stp->sd_pushcnt--; 4975 4976 strunlock(stp, sqlist); 4977 sqlist_free(sqlist); 4978 4979 /* 4980 * Make sure any messages that were propagated are drained. 4981 * Also clear any QFULL bit caused by messages that were propagated. 4982 */ 4983 4984 if (qp->q_next != NULL) { 4985 clr_qfull(qp); 4986 /* 4987 * For the driver calling qprocsoff, propagate_syncq 4988 * frees all the messages instead of putting it in 4989 * the stream head 4990 */ 4991 if (!isdriver && (moved > 0)) 4992 emptysq(qp->q_next->q_syncq); 4993 } 4994 if (wqp->q_next != NULL) { 4995 clr_qfull(wqp); 4996 /* 4997 * We come here for any pop of a module except for the 4998 * case of driver being removed. We don't call emptysq 4999 * if we did not move any messages. This will avoid holding 5000 * PERMOD syncq locks in emptysq 5001 */ 5002 if (moved > 0) 5003 emptysq(wqp->q_next->q_syncq); 5004 } 5005 5006 mutex_enter(SQLOCK(sq)); 5007 sq->sq_rmqcount--; 5008 mutex_exit(SQLOCK(sq)); 5009 } 5010 5011 /* 5012 * Prevent further entry by setting a flag (like SQ_FROZEN, SQ_BLOCKED or 5013 * SQ_WRITER) on a syncq. 5014 * If maxcnt is not -1 it assumes that caller has "maxcnt" claim(s) on the 5015 * sync queue and waits until sq_count reaches maxcnt. 5016 * 5017 * If maxcnt is -1 there's no need to grab sq_putlocks since the caller 5018 * does not care about putnext threads that are in the middle of calling put 5019 * entry points. 5020 * 5021 * This routine is used for both inner and outer syncqs. 5022 */ 5023 static void 5024 blocksq(syncq_t *sq, ushort_t flag, int maxcnt) 5025 { 5026 uint16_t count = 0; 5027 5028 mutex_enter(SQLOCK(sq)); 5029 /* 5030 * Wait for SQ_FROZEN/SQ_BLOCKED to be reset. 5031 * SQ_FROZEN will be set if there is a frozen stream that has a 5032 * queue which also refers to this "shared" syncq. 5033 * SQ_BLOCKED will be set if there is "off" queue which also 5034 * refers to this "shared" syncq. 5035 */ 5036 if (maxcnt != -1) { 5037 count = sq->sq_count; 5038 SQ_PUTLOCKS_ENTER(sq); 5039 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 5040 SUM_SQ_PUTCOUNTS(sq, count); 5041 } 5042 sq->sq_needexcl++; 5043 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 5044 5045 while ((sq->sq_flags & flag) || 5046 (maxcnt != -1 && count > (unsigned)maxcnt)) { 5047 sq->sq_flags |= SQ_WANTWAKEUP; 5048 if (maxcnt != -1) { 5049 SQ_PUTLOCKS_EXIT(sq); 5050 } 5051 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5052 if (maxcnt != -1) { 5053 count = sq->sq_count; 5054 SQ_PUTLOCKS_ENTER(sq); 5055 SUM_SQ_PUTCOUNTS(sq, count); 5056 } 5057 } 5058 sq->sq_needexcl--; 5059 sq->sq_flags |= flag; 5060 ASSERT(maxcnt == -1 || count == maxcnt); 5061 if (maxcnt != -1) { 5062 if (sq->sq_needexcl == 0) { 5063 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 5064 } 5065 SQ_PUTLOCKS_EXIT(sq); 5066 } else if (sq->sq_needexcl == 0) { 5067 SQ_PUTCOUNT_SETFAST(sq); 5068 } 5069 5070 mutex_exit(SQLOCK(sq)); 5071 } 5072 5073 /* 5074 * Reset a flag that was set with blocksq. 5075 * 5076 * Can not use this routine to reset SQ_WRITER. 5077 * 5078 * If "isouter" is set then the syncq is assumed to be an outer perimeter 5079 * and drain_syncq is not called. Instead we rely on the qwriter_outer thread 5080 * to handle the queued qwriter operations. 5081 * 5082 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5083 * sq_putlocks are used. 5084 */ 5085 static void 5086 unblocksq(syncq_t *sq, uint16_t resetflag, int isouter) 5087 { 5088 uint16_t flags; 5089 5090 mutex_enter(SQLOCK(sq)); 5091 ASSERT(resetflag != SQ_WRITER); 5092 ASSERT(sq->sq_flags & resetflag); 5093 flags = sq->sq_flags & ~resetflag; 5094 sq->sq_flags = flags; 5095 if (flags & (SQ_QUEUED | SQ_WANTWAKEUP)) { 5096 if (flags & SQ_WANTWAKEUP) { 5097 flags &= ~SQ_WANTWAKEUP; 5098 cv_broadcast(&sq->sq_wait); 5099 } 5100 sq->sq_flags = flags; 5101 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5102 if (!isouter) { 5103 /* drain_syncq drops SQLOCK */ 5104 drain_syncq(sq); 5105 return; 5106 } 5107 } 5108 } 5109 mutex_exit(SQLOCK(sq)); 5110 } 5111 5112 /* 5113 * Reset a flag that was set with blocksq. 5114 * Does not drain the syncq. Use emptysq() for that. 5115 * Returns 1 if SQ_QUEUED is set. Otherwise 0. 5116 * 5117 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5118 * sq_putlocks are used. 5119 */ 5120 static int 5121 dropsq(syncq_t *sq, uint16_t resetflag) 5122 { 5123 uint16_t flags; 5124 5125 mutex_enter(SQLOCK(sq)); 5126 ASSERT(sq->sq_flags & resetflag); 5127 flags = sq->sq_flags & ~resetflag; 5128 if (flags & SQ_WANTWAKEUP) { 5129 flags &= ~SQ_WANTWAKEUP; 5130 cv_broadcast(&sq->sq_wait); 5131 } 5132 sq->sq_flags = flags; 5133 mutex_exit(SQLOCK(sq)); 5134 if (flags & SQ_QUEUED) 5135 return (1); 5136 return (0); 5137 } 5138 5139 /* 5140 * Empty all the messages on a syncq. 5141 * 5142 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5143 * sq_putlocks are used. 5144 */ 5145 static void 5146 emptysq(syncq_t *sq) 5147 { 5148 uint16_t flags; 5149 5150 mutex_enter(SQLOCK(sq)); 5151 flags = sq->sq_flags; 5152 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5153 /* 5154 * To prevent potential recursive invocation of drain_syncq we 5155 * do not call drain_syncq if count is non-zero. 5156 */ 5157 if (sq->sq_count == 0) { 5158 /* drain_syncq() drops SQLOCK */ 5159 drain_syncq(sq); 5160 return; 5161 } else 5162 sqenable(sq); 5163 } 5164 mutex_exit(SQLOCK(sq)); 5165 } 5166 5167 /* 5168 * Ordered insert while removing duplicates. 5169 */ 5170 static void 5171 sqlist_insert(sqlist_t *sqlist, syncq_t *sqp) 5172 { 5173 syncql_t *sqlp, **prev_sqlpp, *new_sqlp; 5174 5175 prev_sqlpp = &sqlist->sqlist_head; 5176 while ((sqlp = *prev_sqlpp) != NULL) { 5177 if (sqlp->sql_sq >= sqp) { 5178 if (sqlp->sql_sq == sqp) /* duplicate */ 5179 return; 5180 break; 5181 } 5182 prev_sqlpp = &sqlp->sql_next; 5183 } 5184 new_sqlp = &sqlist->sqlist_array[sqlist->sqlist_index++]; 5185 ASSERT((char *)new_sqlp < (char *)sqlist + sqlist->sqlist_size); 5186 new_sqlp->sql_next = sqlp; 5187 new_sqlp->sql_sq = sqp; 5188 *prev_sqlpp = new_sqlp; 5189 } 5190 5191 /* 5192 * Walk the write side queues until we hit either the driver 5193 * or a twist in the stream (_SAMESTR will return false in both 5194 * these cases) then turn around and walk the read side queues 5195 * back up to the stream head. 5196 */ 5197 static void 5198 sqlist_insertall(sqlist_t *sqlist, queue_t *q) 5199 { 5200 while (q != NULL) { 5201 sqlist_insert(sqlist, q->q_syncq); 5202 5203 if (_SAMESTR(q)) 5204 q = q->q_next; 5205 else if (!(q->q_flag & QREADR)) 5206 q = _RD(q); 5207 else 5208 q = NULL; 5209 } 5210 } 5211 5212 /* 5213 * Allocate and build a list of all syncqs in a stream and the syncq(s) 5214 * associated with the "q" parameter. The resulting list is sorted in a 5215 * canonical order and is free of duplicates. 5216 * Assumes the passed queue is a _RD(q). 5217 */ 5218 static sqlist_t * 5219 sqlist_build(queue_t *q, struct stdata *stp, boolean_t do_twist) 5220 { 5221 sqlist_t *sqlist = sqlist_alloc(stp, KM_SLEEP); 5222 5223 /* 5224 * start with the current queue/qpair 5225 */ 5226 ASSERT(q->q_flag & QREADR); 5227 5228 sqlist_insert(sqlist, q->q_syncq); 5229 sqlist_insert(sqlist, _WR(q)->q_syncq); 5230 5231 sqlist_insertall(sqlist, stp->sd_wrq); 5232 if (do_twist) 5233 sqlist_insertall(sqlist, stp->sd_mate->sd_wrq); 5234 5235 return (sqlist); 5236 } 5237 5238 static sqlist_t * 5239 sqlist_alloc(struct stdata *stp, int kmflag) 5240 { 5241 size_t sqlist_size; 5242 sqlist_t *sqlist; 5243 5244 /* 5245 * Allocate 2 syncql_t's for each pushed module. Note that 5246 * the sqlist_t structure already has 4 syncql_t's built in: 5247 * 2 for the stream head, and 2 for the driver/other stream head. 5248 */ 5249 sqlist_size = 2 * sizeof (syncql_t) * stp->sd_pushcnt + 5250 sizeof (sqlist_t); 5251 if (STRMATED(stp)) 5252 sqlist_size += 2 * sizeof (syncql_t) * stp->sd_mate->sd_pushcnt; 5253 sqlist = kmem_alloc(sqlist_size, kmflag); 5254 5255 sqlist->sqlist_head = NULL; 5256 sqlist->sqlist_size = sqlist_size; 5257 sqlist->sqlist_index = 0; 5258 5259 return (sqlist); 5260 } 5261 5262 /* 5263 * Free the list created by sqlist_alloc() 5264 */ 5265 static void 5266 sqlist_free(sqlist_t *sqlist) 5267 { 5268 kmem_free(sqlist, sqlist->sqlist_size); 5269 } 5270 5271 /* 5272 * Prevent any new entries into any syncq in this stream. 5273 * Used by freezestr. 5274 */ 5275 void 5276 strblock(queue_t *q) 5277 { 5278 struct stdata *stp; 5279 syncql_t *sql; 5280 sqlist_t *sqlist; 5281 5282 q = _RD(q); 5283 5284 stp = STREAM(q); 5285 ASSERT(stp != NULL); 5286 5287 /* 5288 * Get a sorted list with all the duplicates removed containing 5289 * all the syncqs referenced by this stream. 5290 */ 5291 sqlist = sqlist_build(q, stp, B_FALSE); 5292 for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) 5293 blocksq(sql->sql_sq, SQ_FROZEN, -1); 5294 sqlist_free(sqlist); 5295 } 5296 5297 /* 5298 * Release the block on new entries into this stream 5299 */ 5300 void 5301 strunblock(queue_t *q) 5302 { 5303 struct stdata *stp; 5304 syncql_t *sql; 5305 sqlist_t *sqlist; 5306 int drain_needed; 5307 5308 q = _RD(q); 5309 5310 /* 5311 * Get a sorted list with all the duplicates removed containing 5312 * all the syncqs referenced by this stream. 5313 * Have to drop the SQ_FROZEN flag on all the syncqs before 5314 * starting to drain them; otherwise the draining might 5315 * cause a freezestr in some module on the stream (which 5316 * would deadlock). 5317 */ 5318 stp = STREAM(q); 5319 ASSERT(stp != NULL); 5320 sqlist = sqlist_build(q, stp, B_FALSE); 5321 drain_needed = 0; 5322 for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) 5323 drain_needed += dropsq(sql->sql_sq, SQ_FROZEN); 5324 if (drain_needed) { 5325 for (sql = sqlist->sqlist_head; sql != NULL; 5326 sql = sql->sql_next) 5327 emptysq(sql->sql_sq); 5328 } 5329 sqlist_free(sqlist); 5330 } 5331 5332 #ifdef DEBUG 5333 static int 5334 qprocsareon(queue_t *rq) 5335 { 5336 if (rq->q_next == NULL) 5337 return (0); 5338 return (_WR(rq->q_next)->q_next == _WR(rq)); 5339 } 5340 5341 int 5342 qclaimed(queue_t *q) 5343 { 5344 uint_t count; 5345 5346 count = q->q_syncq->sq_count; 5347 SUM_SQ_PUTCOUNTS(q->q_syncq, count); 5348 return (count != 0); 5349 } 5350 5351 /* 5352 * Check if anyone has frozen this stream with freezestr 5353 */ 5354 int 5355 frozenstr(queue_t *q) 5356 { 5357 return ((q->q_syncq->sq_flags & SQ_FROZEN) != 0); 5358 } 5359 #endif /* DEBUG */ 5360 5361 /* 5362 * Enter a queue. 5363 * Obsoleted interface. Should not be used. 5364 */ 5365 void 5366 enterq(queue_t *q) 5367 { 5368 entersq(q->q_syncq, SQ_CALLBACK); 5369 } 5370 5371 void 5372 leaveq(queue_t *q) 5373 { 5374 leavesq(q->q_syncq, SQ_CALLBACK); 5375 } 5376 5377 /* 5378 * Enter a perimeter. c_inner and c_outer specifies which concurrency bits 5379 * to check. 5380 * Wait if SQ_QUEUED is set to preserve ordering between messages and qwriter 5381 * calls and the running of open, close and service procedures. 5382 * 5383 * If c_inner bit is set no need to grab sq_putlocks since we don't care 5384 * if other threads have entered or are entering put entry point. 5385 * 5386 * If c_inner bit is set it might have been possible to use 5387 * sq_putlocks/sq_putcounts instead of SQLOCK/sq_count (e.g. to optimize 5388 * open/close path for IP) but since the count may need to be decremented in 5389 * qwait() we wouldn't know which counter to decrement. Currently counter is 5390 * selected by current cpu_seqid and current CPU can change at any moment. XXX 5391 * in the future we might use curthread id bits to select the counter and this 5392 * would stay constant across routine calls. 5393 */ 5394 void 5395 entersq(syncq_t *sq, int entrypoint) 5396 { 5397 uint16_t count = 0; 5398 uint16_t flags; 5399 uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; 5400 uint16_t type; 5401 uint_t c_inner = entrypoint & SQ_CI; 5402 uint_t c_outer = entrypoint & SQ_CO; 5403 5404 /* 5405 * Increment ref count to keep closes out of this queue. 5406 */ 5407 ASSERT(sq); 5408 ASSERT(c_inner && c_outer); 5409 mutex_enter(SQLOCK(sq)); 5410 flags = sq->sq_flags; 5411 type = sq->sq_type; 5412 if (!(type & c_inner)) { 5413 /* Make sure all putcounts now use slowlock. */ 5414 count = sq->sq_count; 5415 SQ_PUTLOCKS_ENTER(sq); 5416 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 5417 SUM_SQ_PUTCOUNTS(sq, count); 5418 sq->sq_needexcl++; 5419 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 5420 waitflags |= SQ_MESSAGES; 5421 } 5422 /* 5423 * Wait until we can enter the inner perimeter. 5424 * If we want exclusive access we wait until sq_count is 0. 5425 * We have to do this before entering the outer perimeter in order 5426 * to preserve put/close message ordering. 5427 */ 5428 while ((flags & waitflags) || (!(type & c_inner) && count != 0)) { 5429 sq->sq_flags = flags | SQ_WANTWAKEUP; 5430 if (!(type & c_inner)) { 5431 SQ_PUTLOCKS_EXIT(sq); 5432 } 5433 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5434 if (!(type & c_inner)) { 5435 count = sq->sq_count; 5436 SQ_PUTLOCKS_ENTER(sq); 5437 SUM_SQ_PUTCOUNTS(sq, count); 5438 } 5439 flags = sq->sq_flags; 5440 } 5441 5442 if (!(type & c_inner)) { 5443 ASSERT(sq->sq_needexcl > 0); 5444 sq->sq_needexcl--; 5445 if (sq->sq_needexcl == 0) { 5446 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 5447 } 5448 } 5449 5450 /* Check if we need to enter the outer perimeter */ 5451 if (!(type & c_outer)) { 5452 /* 5453 * We have to enter the outer perimeter exclusively before 5454 * we can increment sq_count to avoid deadlock. This implies 5455 * that we have to re-check sq_flags and sq_count. 5456 * 5457 * is it possible to have c_inner set when c_outer is not set? 5458 */ 5459 if (!(type & c_inner)) { 5460 SQ_PUTLOCKS_EXIT(sq); 5461 } 5462 mutex_exit(SQLOCK(sq)); 5463 outer_enter(sq->sq_outer, SQ_GOAWAY); 5464 mutex_enter(SQLOCK(sq)); 5465 flags = sq->sq_flags; 5466 /* 5467 * there should be no need to recheck sq_putcounts 5468 * because outer_enter() has already waited for them to clear 5469 * after setting SQ_WRITER. 5470 */ 5471 count = sq->sq_count; 5472 #ifdef DEBUG 5473 /* 5474 * SUMCHECK_SQ_PUTCOUNTS should return the sum instead 5475 * of doing an ASSERT internally. Others should do 5476 * something like 5477 * ASSERT(SUMCHECK_SQ_PUTCOUNTS(sq) == 0); 5478 * without the need to #ifdef DEBUG it. 5479 */ 5480 SUMCHECK_SQ_PUTCOUNTS(sq, 0); 5481 #endif 5482 while ((flags & (SQ_EXCL|SQ_BLOCKED|SQ_FROZEN)) || 5483 (!(type & c_inner) && count != 0)) { 5484 sq->sq_flags = flags | SQ_WANTWAKEUP; 5485 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5486 count = sq->sq_count; 5487 flags = sq->sq_flags; 5488 } 5489 } 5490 5491 sq->sq_count++; 5492 ASSERT(sq->sq_count != 0); /* Wraparound */ 5493 if (!(type & c_inner)) { 5494 /* Exclusive entry */ 5495 ASSERT(sq->sq_count == 1); 5496 sq->sq_flags |= SQ_EXCL; 5497 if (type & c_outer) { 5498 SQ_PUTLOCKS_EXIT(sq); 5499 } 5500 } 5501 mutex_exit(SQLOCK(sq)); 5502 } 5503 5504 /* 5505 * Leave a syncq. Announce to framework that closes may proceed. 5506 * c_inner and c_outer specify which concurrency bits to check. 5507 * 5508 * Must never be called from driver or module put entry point. 5509 * 5510 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5511 * sq_putlocks are used. 5512 */ 5513 void 5514 leavesq(syncq_t *sq, int entrypoint) 5515 { 5516 uint16_t flags; 5517 uint16_t type; 5518 uint_t c_outer = entrypoint & SQ_CO; 5519 #ifdef DEBUG 5520 uint_t c_inner = entrypoint & SQ_CI; 5521 #endif 5522 5523 /* 5524 * Decrement ref count, drain the syncq if possible, and wake up 5525 * any waiting close. 5526 */ 5527 ASSERT(sq); 5528 ASSERT(c_inner && c_outer); 5529 mutex_enter(SQLOCK(sq)); 5530 flags = sq->sq_flags; 5531 type = sq->sq_type; 5532 if (flags & (SQ_QUEUED|SQ_WANTWAKEUP|SQ_WANTEXWAKEUP)) { 5533 5534 if (flags & SQ_WANTWAKEUP) { 5535 flags &= ~SQ_WANTWAKEUP; 5536 cv_broadcast(&sq->sq_wait); 5537 } 5538 if (flags & SQ_WANTEXWAKEUP) { 5539 flags &= ~SQ_WANTEXWAKEUP; 5540 cv_broadcast(&sq->sq_exitwait); 5541 } 5542 5543 if ((flags & SQ_QUEUED) && !(flags & SQ_STAYAWAY)) { 5544 /* 5545 * The syncq needs to be drained. "Exit" the syncq 5546 * before calling drain_syncq. 5547 */ 5548 ASSERT(sq->sq_count != 0); 5549 sq->sq_count--; 5550 ASSERT((flags & SQ_EXCL) || (type & c_inner)); 5551 sq->sq_flags = flags & ~SQ_EXCL; 5552 drain_syncq(sq); 5553 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 5554 /* Check if we need to exit the outer perimeter */ 5555 /* XXX will this ever be true? */ 5556 if (!(type & c_outer)) 5557 outer_exit(sq->sq_outer); 5558 return; 5559 } 5560 } 5561 ASSERT(sq->sq_count != 0); 5562 sq->sq_count--; 5563 ASSERT((flags & SQ_EXCL) || (type & c_inner)); 5564 sq->sq_flags = flags & ~SQ_EXCL; 5565 mutex_exit(SQLOCK(sq)); 5566 5567 /* Check if we need to exit the outer perimeter */ 5568 if (!(sq->sq_type & c_outer)) 5569 outer_exit(sq->sq_outer); 5570 } 5571 5572 /* 5573 * Prevent q_next from changing in this stream by incrementing sq_count. 5574 * 5575 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5576 * sq_putlocks are used. 5577 */ 5578 void 5579 claimq(queue_t *qp) 5580 { 5581 syncq_t *sq = qp->q_syncq; 5582 5583 mutex_enter(SQLOCK(sq)); 5584 sq->sq_count++; 5585 ASSERT(sq->sq_count != 0); /* Wraparound */ 5586 mutex_exit(SQLOCK(sq)); 5587 } 5588 5589 /* 5590 * Undo claimq. 5591 * 5592 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 5593 * sq_putlocks are used. 5594 */ 5595 void 5596 releaseq(queue_t *qp) 5597 { 5598 syncq_t *sq = qp->q_syncq; 5599 uint16_t flags; 5600 5601 mutex_enter(SQLOCK(sq)); 5602 ASSERT(sq->sq_count > 0); 5603 sq->sq_count--; 5604 5605 flags = sq->sq_flags; 5606 if (flags & (SQ_WANTWAKEUP|SQ_QUEUED)) { 5607 if (flags & SQ_WANTWAKEUP) { 5608 flags &= ~SQ_WANTWAKEUP; 5609 cv_broadcast(&sq->sq_wait); 5610 } 5611 sq->sq_flags = flags; 5612 if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { 5613 /* 5614 * To prevent potential recursive invocation of 5615 * drain_syncq we do not call drain_syncq if count is 5616 * non-zero. 5617 */ 5618 if (sq->sq_count == 0) { 5619 drain_syncq(sq); 5620 return; 5621 } else 5622 sqenable(sq); 5623 } 5624 } 5625 mutex_exit(SQLOCK(sq)); 5626 } 5627 5628 /* 5629 * Prevent q_next from changing in this stream by incrementing sd_refcnt. 5630 */ 5631 void 5632 claimstr(queue_t *qp) 5633 { 5634 struct stdata *stp = STREAM(qp); 5635 5636 mutex_enter(&stp->sd_reflock); 5637 stp->sd_refcnt++; 5638 ASSERT(stp->sd_refcnt != 0); /* Wraparound */ 5639 mutex_exit(&stp->sd_reflock); 5640 } 5641 5642 /* 5643 * Undo claimstr. 5644 */ 5645 void 5646 releasestr(queue_t *qp) 5647 { 5648 struct stdata *stp = STREAM(qp); 5649 5650 mutex_enter(&stp->sd_reflock); 5651 ASSERT(stp->sd_refcnt != 0); 5652 if (--stp->sd_refcnt == 0) 5653 cv_broadcast(&stp->sd_refmonitor); 5654 mutex_exit(&stp->sd_reflock); 5655 } 5656 5657 static syncq_t * 5658 new_syncq(void) 5659 { 5660 return (kmem_cache_alloc(syncq_cache, KM_SLEEP)); 5661 } 5662 5663 static void 5664 free_syncq(syncq_t *sq) 5665 { 5666 ASSERT(sq->sq_head == NULL); 5667 ASSERT(sq->sq_outer == NULL); 5668 ASSERT(sq->sq_callbpend == NULL); 5669 ASSERT((sq->sq_onext == NULL && sq->sq_oprev == NULL) || 5670 (sq->sq_onext == sq && sq->sq_oprev == sq)); 5671 5672 if (sq->sq_ciputctrl != NULL) { 5673 ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); 5674 SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, 5675 sq->sq_nciputctrl, 0); 5676 ASSERT(ciputctrl_cache != NULL); 5677 kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); 5678 } 5679 5680 sq->sq_tail = NULL; 5681 sq->sq_evhead = NULL; 5682 sq->sq_evtail = NULL; 5683 sq->sq_ciputctrl = NULL; 5684 sq->sq_nciputctrl = 0; 5685 sq->sq_count = 0; 5686 sq->sq_rmqcount = 0; 5687 sq->sq_callbflags = 0; 5688 sq->sq_cancelid = 0; 5689 sq->sq_next = NULL; 5690 sq->sq_needexcl = 0; 5691 sq->sq_svcflags = 0; 5692 sq->sq_nqueues = 0; 5693 sq->sq_pri = 0; 5694 sq->sq_onext = NULL; 5695 sq->sq_oprev = NULL; 5696 sq->sq_flags = 0; 5697 sq->sq_type = 0; 5698 sq->sq_servcount = 0; 5699 5700 kmem_cache_free(syncq_cache, sq); 5701 } 5702 5703 /* Outer perimeter code */ 5704 5705 /* 5706 * The outer syncq uses the fields and flags in the syncq slightly 5707 * differently from the inner syncqs. 5708 * sq_count Incremented when there are pending or running 5709 * writers at the outer perimeter to prevent the set of 5710 * inner syncqs that belong to the outer perimeter from 5711 * changing. 5712 * sq_head/tail List of deferred qwriter(OUTER) operations. 5713 * 5714 * SQ_BLOCKED Set to prevent traversing of sq_next,sq_prev while 5715 * inner syncqs are added to or removed from the 5716 * outer perimeter. 5717 * SQ_QUEUED sq_head/tail has messages or events queued. 5718 * 5719 * SQ_WRITER A thread is currently traversing all the inner syncqs 5720 * setting the SQ_WRITER flag. 5721 */ 5722 5723 /* 5724 * Get write access at the outer perimeter. 5725 * Note that read access is done by entersq, putnext, and put by simply 5726 * incrementing sq_count in the inner syncq. 5727 * 5728 * Waits until "flags" is no longer set in the outer to prevent multiple 5729 * threads from having write access at the same time. SQ_WRITER has to be part 5730 * of "flags". 5731 * 5732 * Increases sq_count on the outer syncq to keep away outer_insert/remove 5733 * until the outer_exit is finished. 5734 * 5735 * outer_enter is vulnerable to starvation since it does not prevent new 5736 * threads from entering the inner syncqs while it is waiting for sq_count to 5737 * go to zero. 5738 */ 5739 void 5740 outer_enter(syncq_t *outer, uint16_t flags) 5741 { 5742 syncq_t *sq; 5743 int wait_needed; 5744 uint16_t count; 5745 5746 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5747 outer->sq_oprev != NULL); 5748 ASSERT(flags & SQ_WRITER); 5749 5750 retry: 5751 mutex_enter(SQLOCK(outer)); 5752 while (outer->sq_flags & flags) { 5753 outer->sq_flags |= SQ_WANTWAKEUP; 5754 cv_wait(&outer->sq_wait, SQLOCK(outer)); 5755 } 5756 5757 ASSERT(!(outer->sq_flags & SQ_WRITER)); 5758 outer->sq_flags |= SQ_WRITER; 5759 outer->sq_count++; 5760 ASSERT(outer->sq_count != 0); /* wraparound */ 5761 wait_needed = 0; 5762 /* 5763 * Set SQ_WRITER on all the inner syncqs while holding 5764 * the SQLOCK on the outer syncq. This ensures that the changing 5765 * of SQ_WRITER is atomic under the outer SQLOCK. 5766 */ 5767 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 5768 mutex_enter(SQLOCK(sq)); 5769 count = sq->sq_count; 5770 SQ_PUTLOCKS_ENTER(sq); 5771 sq->sq_flags |= SQ_WRITER; 5772 SUM_SQ_PUTCOUNTS(sq, count); 5773 if (count != 0) 5774 wait_needed = 1; 5775 SQ_PUTLOCKS_EXIT(sq); 5776 mutex_exit(SQLOCK(sq)); 5777 } 5778 mutex_exit(SQLOCK(outer)); 5779 5780 /* 5781 * Get everybody out of the syncqs sequentially. 5782 * Note that we don't actually need to acquire the PUTLOCKS, since 5783 * we have already cleared the fastbit, and set QWRITER. By 5784 * definition, the count can not increase since putnext will 5785 * take the slowlock path (and the purpose of acquiring the 5786 * putlocks was to make sure it didn't increase while we were 5787 * waiting). 5788 * 5789 * Note that we still acquire the PUTLOCKS to be safe. 5790 */ 5791 if (wait_needed) { 5792 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 5793 mutex_enter(SQLOCK(sq)); 5794 count = sq->sq_count; 5795 SQ_PUTLOCKS_ENTER(sq); 5796 SUM_SQ_PUTCOUNTS(sq, count); 5797 while (count != 0) { 5798 sq->sq_flags |= SQ_WANTWAKEUP; 5799 SQ_PUTLOCKS_EXIT(sq); 5800 cv_wait(&sq->sq_wait, SQLOCK(sq)); 5801 count = sq->sq_count; 5802 SQ_PUTLOCKS_ENTER(sq); 5803 SUM_SQ_PUTCOUNTS(sq, count); 5804 } 5805 SQ_PUTLOCKS_EXIT(sq); 5806 mutex_exit(SQLOCK(sq)); 5807 } 5808 /* 5809 * Verify that none of the flags got set while we 5810 * were waiting for the sq_counts to drop. 5811 * If this happens we exit and retry entering the 5812 * outer perimeter. 5813 */ 5814 mutex_enter(SQLOCK(outer)); 5815 if (outer->sq_flags & (flags & ~SQ_WRITER)) { 5816 mutex_exit(SQLOCK(outer)); 5817 outer_exit(outer); 5818 goto retry; 5819 } 5820 mutex_exit(SQLOCK(outer)); 5821 } 5822 } 5823 5824 /* 5825 * Drop the write access at the outer perimeter. 5826 * Read access is dropped implicitly (by putnext, put, and leavesq) by 5827 * decrementing sq_count. 5828 */ 5829 void 5830 outer_exit(syncq_t *outer) 5831 { 5832 syncq_t *sq; 5833 int drain_needed; 5834 uint16_t flags; 5835 5836 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5837 outer->sq_oprev != NULL); 5838 ASSERT(MUTEX_NOT_HELD(SQLOCK(outer))); 5839 5840 /* 5841 * Atomically (from the perspective of threads calling become_writer) 5842 * drop the write access at the outer perimeter by holding 5843 * SQLOCK(outer) across all the dropsq calls and the resetting of 5844 * SQ_WRITER. 5845 * This defines a locking order between the outer perimeter 5846 * SQLOCK and the inner perimeter SQLOCKs. 5847 */ 5848 mutex_enter(SQLOCK(outer)); 5849 flags = outer->sq_flags; 5850 ASSERT(outer->sq_flags & SQ_WRITER); 5851 if (flags & SQ_QUEUED) { 5852 write_now(outer); 5853 flags = outer->sq_flags; 5854 } 5855 5856 /* 5857 * sq_onext is stable since sq_count has not yet been decreased. 5858 * Reset the SQ_WRITER flags in all syncqs. 5859 * After dropping SQ_WRITER on the outer syncq we empty all the 5860 * inner syncqs. 5861 */ 5862 drain_needed = 0; 5863 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) 5864 drain_needed += dropsq(sq, SQ_WRITER); 5865 ASSERT(!(outer->sq_flags & SQ_QUEUED)); 5866 flags &= ~SQ_WRITER; 5867 if (drain_needed) { 5868 outer->sq_flags = flags; 5869 mutex_exit(SQLOCK(outer)); 5870 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) 5871 emptysq(sq); 5872 mutex_enter(SQLOCK(outer)); 5873 flags = outer->sq_flags; 5874 } 5875 if (flags & SQ_WANTWAKEUP) { 5876 flags &= ~SQ_WANTWAKEUP; 5877 cv_broadcast(&outer->sq_wait); 5878 } 5879 outer->sq_flags = flags; 5880 ASSERT(outer->sq_count > 0); 5881 outer->sq_count--; 5882 mutex_exit(SQLOCK(outer)); 5883 } 5884 5885 /* 5886 * Add another syncq to an outer perimeter. 5887 * Block out all other access to the outer perimeter while it is being 5888 * changed using blocksq. 5889 * Assumes that the caller has *not* done an outer_enter. 5890 * 5891 * Vulnerable to starvation in blocksq. 5892 */ 5893 static void 5894 outer_insert(syncq_t *outer, syncq_t *sq) 5895 { 5896 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5897 outer->sq_oprev != NULL); 5898 ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && 5899 sq->sq_oprev == NULL); /* Can't be in an outer perimeter */ 5900 5901 /* Get exclusive access to the outer perimeter list */ 5902 blocksq(outer, SQ_BLOCKED, 0); 5903 ASSERT(outer->sq_flags & SQ_BLOCKED); 5904 ASSERT(!(outer->sq_flags & SQ_WRITER)); 5905 5906 mutex_enter(SQLOCK(sq)); 5907 sq->sq_outer = outer; 5908 outer->sq_onext->sq_oprev = sq; 5909 sq->sq_onext = outer->sq_onext; 5910 outer->sq_onext = sq; 5911 sq->sq_oprev = outer; 5912 mutex_exit(SQLOCK(sq)); 5913 unblocksq(outer, SQ_BLOCKED, 1); 5914 } 5915 5916 /* 5917 * Remove a syncq from an outer perimeter. 5918 * Block out all other access to the outer perimeter while it is being 5919 * changed using blocksq. 5920 * Assumes that the caller has *not* done an outer_enter. 5921 * 5922 * Vulnerable to starvation in blocksq. 5923 */ 5924 static void 5925 outer_remove(syncq_t *outer, syncq_t *sq) 5926 { 5927 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 5928 outer->sq_oprev != NULL); 5929 ASSERT(sq->sq_outer == outer); 5930 5931 /* Get exclusive access to the outer perimeter list */ 5932 blocksq(outer, SQ_BLOCKED, 0); 5933 ASSERT(outer->sq_flags & SQ_BLOCKED); 5934 ASSERT(!(outer->sq_flags & SQ_WRITER)); 5935 5936 mutex_enter(SQLOCK(sq)); 5937 sq->sq_outer = NULL; 5938 sq->sq_onext->sq_oprev = sq->sq_oprev; 5939 sq->sq_oprev->sq_onext = sq->sq_onext; 5940 sq->sq_oprev = sq->sq_onext = NULL; 5941 mutex_exit(SQLOCK(sq)); 5942 unblocksq(outer, SQ_BLOCKED, 1); 5943 } 5944 5945 /* 5946 * Queue a deferred qwriter(OUTER) callback for this outer perimeter. 5947 * If this is the first callback for this outer perimeter then add 5948 * this outer perimeter to the list of outer perimeters that 5949 * the qwriter_outer_thread will process. 5950 * 5951 * Increments sq_count in the outer syncq to prevent the membership 5952 * of the outer perimeter (in terms of inner syncqs) to change while 5953 * the callback is pending. 5954 */ 5955 static void 5956 queue_writer(syncq_t *outer, void (*func)(), queue_t *q, mblk_t *mp) 5957 { 5958 ASSERT(MUTEX_HELD(SQLOCK(outer))); 5959 5960 mp->b_prev = (mblk_t *)func; 5961 mp->b_queue = q; 5962 mp->b_next = NULL; 5963 outer->sq_count++; /* Decremented when dequeued */ 5964 ASSERT(outer->sq_count != 0); /* Wraparound */ 5965 if (outer->sq_evhead == NULL) { 5966 /* First message. */ 5967 outer->sq_evhead = outer->sq_evtail = mp; 5968 outer->sq_flags |= SQ_EVENTS; 5969 mutex_exit(SQLOCK(outer)); 5970 STRSTAT(qwr_outer); 5971 (void) taskq_dispatch(streams_taskq, 5972 (task_func_t *)qwriter_outer_service, outer, TQ_SLEEP); 5973 } else { 5974 ASSERT(outer->sq_flags & SQ_EVENTS); 5975 outer->sq_evtail->b_next = mp; 5976 outer->sq_evtail = mp; 5977 mutex_exit(SQLOCK(outer)); 5978 } 5979 } 5980 5981 /* 5982 * Try and upgrade to write access at the outer perimeter. If this can 5983 * not be done without blocking then queue the callback to be done 5984 * by the qwriter_outer_thread. 5985 * 5986 * This routine can only be called from put or service procedures plus 5987 * asynchronous callback routines that have properly entered the queue (with 5988 * entersq). Thus qwriter(OUTER) assumes the caller has one claim on the syncq 5989 * associated with q. 5990 */ 5991 void 5992 qwriter_outer(queue_t *q, mblk_t *mp, void (*func)()) 5993 { 5994 syncq_t *osq, *sq, *outer; 5995 int failed; 5996 uint16_t flags; 5997 5998 osq = q->q_syncq; 5999 outer = osq->sq_outer; 6000 if (outer == NULL) 6001 panic("qwriter(PERIM_OUTER): no outer perimeter"); 6002 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 6003 outer->sq_oprev != NULL); 6004 6005 mutex_enter(SQLOCK(outer)); 6006 flags = outer->sq_flags; 6007 /* 6008 * If some thread is traversing sq_next, or if we are blocked by 6009 * outer_insert or outer_remove, or if the we already have queued 6010 * callbacks, then queue this callback for later processing. 6011 * 6012 * Also queue the qwriter for an interrupt thread in order 6013 * to reduce the time spent running at high IPL. 6014 * to identify there are events. 6015 */ 6016 if ((flags & SQ_GOAWAY) || (curthread->t_pri >= kpreemptpri)) { 6017 /* 6018 * Queue the become_writer request. 6019 * The queueing is atomic under SQLOCK(outer) in order 6020 * to synchronize with outer_exit. 6021 * queue_writer will drop the outer SQLOCK 6022 */ 6023 if (flags & SQ_BLOCKED) { 6024 /* Must set SQ_WRITER on inner perimeter */ 6025 mutex_enter(SQLOCK(osq)); 6026 osq->sq_flags |= SQ_WRITER; 6027 mutex_exit(SQLOCK(osq)); 6028 } else { 6029 if (!(flags & SQ_WRITER)) { 6030 /* 6031 * The outer could have been SQ_BLOCKED thus 6032 * SQ_WRITER might not be set on the inner. 6033 */ 6034 mutex_enter(SQLOCK(osq)); 6035 osq->sq_flags |= SQ_WRITER; 6036 mutex_exit(SQLOCK(osq)); 6037 } 6038 ASSERT(osq->sq_flags & SQ_WRITER); 6039 } 6040 queue_writer(outer, func, q, mp); 6041 return; 6042 } 6043 /* 6044 * We are half-way to exclusive access to the outer perimeter. 6045 * Prevent any outer_enter, qwriter(OUTER), or outer_insert/remove 6046 * while the inner syncqs are traversed. 6047 */ 6048 outer->sq_count++; 6049 ASSERT(outer->sq_count != 0); /* wraparound */ 6050 flags |= SQ_WRITER; 6051 /* 6052 * Check if we can run the function immediately. Mark all 6053 * syncqs with the writer flag to prevent new entries into 6054 * put and service procedures. 6055 * 6056 * Set SQ_WRITER on all the inner syncqs while holding 6057 * the SQLOCK on the outer syncq. This ensures that the changing 6058 * of SQ_WRITER is atomic under the outer SQLOCK. 6059 */ 6060 failed = 0; 6061 for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { 6062 uint16_t count; 6063 uint_t maxcnt = (sq == osq) ? 1 : 0; 6064 6065 mutex_enter(SQLOCK(sq)); 6066 count = sq->sq_count; 6067 SQ_PUTLOCKS_ENTER(sq); 6068 SUM_SQ_PUTCOUNTS(sq, count); 6069 if (sq->sq_count > maxcnt) 6070 failed = 1; 6071 sq->sq_flags |= SQ_WRITER; 6072 SQ_PUTLOCKS_EXIT(sq); 6073 mutex_exit(SQLOCK(sq)); 6074 } 6075 if (failed) { 6076 /* 6077 * Some other thread has a read claim on the outer perimeter. 6078 * Queue the callback for deferred processing. 6079 * 6080 * queue_writer will set SQ_QUEUED before we drop SQ_WRITER 6081 * so that other qwriter(OUTER) calls will queue their 6082 * callbacks as well. queue_writer increments sq_count so we 6083 * decrement to compensate for the our increment. 6084 * 6085 * Dropping SQ_WRITER enables the writer thread to work 6086 * on this outer perimeter. 6087 */ 6088 outer->sq_flags = flags; 6089 queue_writer(outer, func, q, mp); 6090 /* queue_writer dropper the lock */ 6091 mutex_enter(SQLOCK(outer)); 6092 ASSERT(outer->sq_count > 0); 6093 outer->sq_count--; 6094 ASSERT(outer->sq_flags & SQ_WRITER); 6095 flags = outer->sq_flags; 6096 flags &= ~SQ_WRITER; 6097 if (flags & SQ_WANTWAKEUP) { 6098 flags &= ~SQ_WANTWAKEUP; 6099 cv_broadcast(&outer->sq_wait); 6100 } 6101 outer->sq_flags = flags; 6102 mutex_exit(SQLOCK(outer)); 6103 return; 6104 } else { 6105 outer->sq_flags = flags; 6106 mutex_exit(SQLOCK(outer)); 6107 } 6108 6109 /* Can run it immediately */ 6110 (*func)(q, mp); 6111 6112 outer_exit(outer); 6113 } 6114 6115 /* 6116 * Dequeue all writer callbacks from the outer perimeter and run them. 6117 */ 6118 static void 6119 write_now(syncq_t *outer) 6120 { 6121 mblk_t *mp; 6122 queue_t *q; 6123 void (*func)(); 6124 6125 ASSERT(MUTEX_HELD(SQLOCK(outer))); 6126 ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && 6127 outer->sq_oprev != NULL); 6128 while ((mp = outer->sq_evhead) != NULL) { 6129 /* 6130 * queues cannot be placed on the queuelist on the outer 6131 * perimeter. 6132 */ 6133 ASSERT(!(outer->sq_flags & SQ_MESSAGES)); 6134 ASSERT((outer->sq_flags & SQ_EVENTS)); 6135 6136 outer->sq_evhead = mp->b_next; 6137 if (outer->sq_evhead == NULL) { 6138 outer->sq_evtail = NULL; 6139 outer->sq_flags &= ~SQ_EVENTS; 6140 } 6141 ASSERT(outer->sq_count != 0); 6142 outer->sq_count--; /* Incremented when enqueued. */ 6143 mutex_exit(SQLOCK(outer)); 6144 /* 6145 * Drop the message if the queue is closing. 6146 * Make sure that the queue is "claimed" when the callback 6147 * is run in order to satisfy various ASSERTs. 6148 */ 6149 q = mp->b_queue; 6150 func = (void (*)())mp->b_prev; 6151 ASSERT(func != NULL); 6152 mp->b_next = mp->b_prev = NULL; 6153 if (q->q_flag & QWCLOSE) { 6154 freemsg(mp); 6155 } else { 6156 claimq(q); 6157 (*func)(q, mp); 6158 releaseq(q); 6159 } 6160 mutex_enter(SQLOCK(outer)); 6161 } 6162 ASSERT(MUTEX_HELD(SQLOCK(outer))); 6163 } 6164 6165 /* 6166 * The list of messages on the inner syncq is effectively hashed 6167 * by destination queue. These destination queues are doubly 6168 * linked lists (hopefully) in priority order. Messages are then 6169 * put on the queue referenced by the q_sqhead/q_sqtail elements. 6170 * Additional messages are linked together by the b_next/b_prev 6171 * elements in the mblk, with (similar to putq()) the first message 6172 * having a NULL b_prev and the last message having a NULL b_next. 6173 * 6174 * Events, such as qwriter callbacks, are put onto a list in FIFO 6175 * order referenced by sq_evhead, and sq_evtail. This is a singly 6176 * linked list, and messages here MUST be processed in the order queued. 6177 */ 6178 6179 /* 6180 * Run the events on the syncq event list (sq_evhead). 6181 * Assumes there is only one claim on the syncq, it is 6182 * already exclusive (SQ_EXCL set), and the SQLOCK held. 6183 * Messages here are processed in order, with the SQ_EXCL bit 6184 * held all the way through till the last message is processed. 6185 */ 6186 void 6187 sq_run_events(syncq_t *sq) 6188 { 6189 mblk_t *bp; 6190 queue_t *qp; 6191 uint16_t flags = sq->sq_flags; 6192 void (*func)(); 6193 6194 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6195 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6196 sq->sq_oprev == NULL) || 6197 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6198 sq->sq_oprev != NULL)); 6199 6200 ASSERT(flags & SQ_EXCL); 6201 ASSERT(sq->sq_count == 1); 6202 6203 /* 6204 * We need to process all of the events on this list. It 6205 * is possible that new events will be added while we are 6206 * away processing a callback, so on every loop, we start 6207 * back at the beginning of the list. 6208 */ 6209 /* 6210 * We have to reaccess sq_evhead since there is a 6211 * possibility of a new entry while we were running 6212 * the callback. 6213 */ 6214 for (bp = sq->sq_evhead; bp != NULL; bp = sq->sq_evhead) { 6215 ASSERT(bp->b_queue->q_syncq == sq); 6216 ASSERT(sq->sq_flags & SQ_EVENTS); 6217 6218 qp = bp->b_queue; 6219 func = (void (*)())bp->b_prev; 6220 ASSERT(func != NULL); 6221 6222 /* 6223 * Messages from the event queue must be taken off in 6224 * FIFO order. 6225 */ 6226 ASSERT(sq->sq_evhead == bp); 6227 sq->sq_evhead = bp->b_next; 6228 6229 if (bp->b_next == NULL) { 6230 /* Deleting last */ 6231 ASSERT(sq->sq_evtail == bp); 6232 sq->sq_evtail = NULL; 6233 sq->sq_flags &= ~SQ_EVENTS; 6234 } 6235 bp->b_prev = bp->b_next = NULL; 6236 ASSERT(bp->b_datap->db_ref != 0); 6237 6238 mutex_exit(SQLOCK(sq)); 6239 6240 (*func)(qp, bp); 6241 6242 mutex_enter(SQLOCK(sq)); 6243 /* 6244 * re-read the flags, since they could have changed. 6245 */ 6246 flags = sq->sq_flags; 6247 ASSERT(flags & SQ_EXCL); 6248 } 6249 ASSERT(sq->sq_evhead == NULL && sq->sq_evtail == NULL); 6250 ASSERT(!(sq->sq_flags & SQ_EVENTS)); 6251 6252 if (flags & SQ_WANTWAKEUP) { 6253 flags &= ~SQ_WANTWAKEUP; 6254 cv_broadcast(&sq->sq_wait); 6255 } 6256 if (flags & SQ_WANTEXWAKEUP) { 6257 flags &= ~SQ_WANTEXWAKEUP; 6258 cv_broadcast(&sq->sq_exitwait); 6259 } 6260 sq->sq_flags = flags; 6261 } 6262 6263 /* 6264 * Put messages on the event list. 6265 * If we can go exclusive now, do so and process the event list, otherwise 6266 * let the last claim service this list (or wake the sqthread). 6267 * This procedure assumes SQLOCK is held. To run the event list, it 6268 * must be called with no claims. 6269 */ 6270 static void 6271 sqfill_events(syncq_t *sq, queue_t *q, mblk_t *mp, void (*func)()) 6272 { 6273 uint16_t count; 6274 6275 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6276 ASSERT(func != NULL); 6277 6278 /* 6279 * This is a callback. Add it to the list of callbacks 6280 * and see about upgrading. 6281 */ 6282 mp->b_prev = (mblk_t *)func; 6283 mp->b_queue = q; 6284 mp->b_next = NULL; 6285 if (sq->sq_evhead == NULL) { 6286 sq->sq_evhead = sq->sq_evtail = mp; 6287 sq->sq_flags |= SQ_EVENTS; 6288 } else { 6289 ASSERT(sq->sq_evtail != NULL); 6290 ASSERT(sq->sq_evtail->b_next == NULL); 6291 ASSERT(sq->sq_flags & SQ_EVENTS); 6292 sq->sq_evtail->b_next = mp; 6293 sq->sq_evtail = mp; 6294 } 6295 /* 6296 * We have set SQ_EVENTS, so threads will have to 6297 * unwind out of the perimeter, and new entries will 6298 * not grab a putlock. But we still need to know 6299 * how many threads have already made a claim to the 6300 * syncq, so grab the putlocks, and sum the counts. 6301 * If there are no claims on the syncq, we can upgrade 6302 * to exclusive, and run the event list. 6303 * NOTE: We hold the SQLOCK, so we can just grab the 6304 * putlocks. 6305 */ 6306 count = sq->sq_count; 6307 SQ_PUTLOCKS_ENTER(sq); 6308 SUM_SQ_PUTCOUNTS(sq, count); 6309 /* 6310 * We have no claim, so we need to check if there 6311 * are no others, then we can upgrade. 6312 */ 6313 /* 6314 * There are currently no claims on 6315 * the syncq by this thread (at least on this entry). The thread who has 6316 * the claim should drain syncq. 6317 */ 6318 if (count > 0) { 6319 /* 6320 * Can't upgrade - other threads inside. 6321 */ 6322 SQ_PUTLOCKS_EXIT(sq); 6323 mutex_exit(SQLOCK(sq)); 6324 return; 6325 } 6326 /* 6327 * Need to set SQ_EXCL and make a claim on the syncq. 6328 */ 6329 ASSERT((sq->sq_flags & SQ_EXCL) == 0); 6330 sq->sq_flags |= SQ_EXCL; 6331 ASSERT(sq->sq_count == 0); 6332 sq->sq_count++; 6333 SQ_PUTLOCKS_EXIT(sq); 6334 6335 /* Process the events list */ 6336 sq_run_events(sq); 6337 6338 /* 6339 * Release our claim... 6340 */ 6341 sq->sq_count--; 6342 6343 /* 6344 * And release SQ_EXCL. 6345 * We don't need to acquire the putlocks to release 6346 * SQ_EXCL, since we are exclusive, and hold the SQLOCK. 6347 */ 6348 sq->sq_flags &= ~SQ_EXCL; 6349 6350 /* 6351 * sq_run_events should have released SQ_EXCL 6352 */ 6353 ASSERT(!(sq->sq_flags & SQ_EXCL)); 6354 6355 /* 6356 * If anything happened while we were running the 6357 * events (or was there before), we need to process 6358 * them now. We shouldn't be exclusive sine we 6359 * released the perimeter above (plus, we asserted 6360 * for it). 6361 */ 6362 if (!(sq->sq_flags & SQ_STAYAWAY) && (sq->sq_flags & SQ_QUEUED)) 6363 drain_syncq(sq); 6364 else 6365 mutex_exit(SQLOCK(sq)); 6366 } 6367 6368 /* 6369 * Perform delayed processing. The caller has to make sure that it is safe 6370 * to enter the syncq (e.g. by checking that none of the SQ_STAYAWAY bits are 6371 * set). 6372 * 6373 * Assume that the caller has NO claims on the syncq. However, a claim 6374 * on the syncq does not indicate that a thread is draining the syncq. 6375 * There may be more claims on the syncq than there are threads draining 6376 * (i.e. #_threads_draining <= sq_count) 6377 * 6378 * drain_syncq has to terminate when one of the SQ_STAYAWAY bits gets set 6379 * in order to preserve qwriter(OUTER) ordering constraints. 6380 * 6381 * sq_putcount only needs to be checked when dispatching the queued 6382 * writer call for CIPUT sync queue, but this is handled in sq_run_events. 6383 */ 6384 void 6385 drain_syncq(syncq_t *sq) 6386 { 6387 queue_t *qp; 6388 uint16_t count; 6389 uint16_t type = sq->sq_type; 6390 uint16_t flags = sq->sq_flags; 6391 boolean_t bg_service = sq->sq_svcflags & SQ_SERVICE; 6392 6393 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, 6394 "drain_syncq start:%p", sq); 6395 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6396 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6397 sq->sq_oprev == NULL) || 6398 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6399 sq->sq_oprev != NULL)); 6400 6401 /* 6402 * Drop SQ_SERVICE flag. 6403 */ 6404 if (bg_service) 6405 sq->sq_svcflags &= ~SQ_SERVICE; 6406 6407 /* 6408 * If SQ_EXCL is set, someone else is processing this syncq - let them 6409 * finish the job. 6410 */ 6411 if (flags & SQ_EXCL) { 6412 if (bg_service) { 6413 ASSERT(sq->sq_servcount != 0); 6414 sq->sq_servcount--; 6415 } 6416 mutex_exit(SQLOCK(sq)); 6417 return; 6418 } 6419 6420 /* 6421 * This routine can be called by a background thread if 6422 * it was scheduled by a hi-priority thread. SO, if there are 6423 * NOT messages queued, return (remember, we have the SQLOCK, 6424 * and it cannot change until we release it). Wakeup any waiters also. 6425 */ 6426 if (!(flags & SQ_QUEUED)) { 6427 if (flags & SQ_WANTWAKEUP) { 6428 flags &= ~SQ_WANTWAKEUP; 6429 cv_broadcast(&sq->sq_wait); 6430 } 6431 if (flags & SQ_WANTEXWAKEUP) { 6432 flags &= ~SQ_WANTEXWAKEUP; 6433 cv_broadcast(&sq->sq_exitwait); 6434 } 6435 sq->sq_flags = flags; 6436 if (bg_service) { 6437 ASSERT(sq->sq_servcount != 0); 6438 sq->sq_servcount--; 6439 } 6440 mutex_exit(SQLOCK(sq)); 6441 return; 6442 } 6443 6444 /* 6445 * If this is not a concurrent put perimeter, we need to 6446 * become exclusive to drain. Also, if not CIPUT, we would 6447 * not have acquired a putlock, so we don't need to check 6448 * the putcounts. If not entering with a claim, we test 6449 * for sq_count == 0. 6450 */ 6451 type = sq->sq_type; 6452 if (!(type & SQ_CIPUT)) { 6453 if (sq->sq_count > 1) { 6454 if (bg_service) { 6455 ASSERT(sq->sq_servcount != 0); 6456 sq->sq_servcount--; 6457 } 6458 mutex_exit(SQLOCK(sq)); 6459 return; 6460 } 6461 sq->sq_flags |= SQ_EXCL; 6462 } 6463 6464 /* 6465 * This is where we make a claim to the syncq. 6466 * This can either be done by incrementing a putlock, or 6467 * the sq_count. But since we already have the SQLOCK 6468 * here, we just bump the sq_count. 6469 * 6470 * Note that after we make a claim, we need to let the code 6471 * fall through to the end of this routine to clean itself 6472 * up. A return in the while loop will put the syncq in a 6473 * very bad state. 6474 */ 6475 sq->sq_count++; 6476 ASSERT(sq->sq_count != 0); /* wraparound */ 6477 6478 while ((flags = sq->sq_flags) & SQ_QUEUED) { 6479 /* 6480 * If we are told to stayaway or went exclusive, 6481 * we are done. 6482 */ 6483 if (flags & (SQ_STAYAWAY)) { 6484 break; 6485 } 6486 6487 /* 6488 * If there are events to run, do so. 6489 * We have one claim to the syncq, so if there are 6490 * more than one, other threads are running. 6491 */ 6492 if (sq->sq_evhead != NULL) { 6493 ASSERT(sq->sq_flags & SQ_EVENTS); 6494 6495 count = sq->sq_count; 6496 SQ_PUTLOCKS_ENTER(sq); 6497 SUM_SQ_PUTCOUNTS(sq, count); 6498 if (count > 1) { 6499 SQ_PUTLOCKS_EXIT(sq); 6500 /* Can't upgrade - other threads inside */ 6501 break; 6502 } 6503 ASSERT((flags & SQ_EXCL) == 0); 6504 sq->sq_flags = flags | SQ_EXCL; 6505 SQ_PUTLOCKS_EXIT(sq); 6506 /* 6507 * we have the only claim, run the events, 6508 * sq_run_events will clear the SQ_EXCL flag. 6509 */ 6510 sq_run_events(sq); 6511 6512 /* 6513 * If this is a CIPUT perimeter, we need 6514 * to drop the SQ_EXCL flag so we can properly 6515 * continue draining the syncq. 6516 */ 6517 if (type & SQ_CIPUT) { 6518 ASSERT(sq->sq_flags & SQ_EXCL); 6519 sq->sq_flags &= ~SQ_EXCL; 6520 } 6521 6522 /* 6523 * And go back to the beginning just in case 6524 * anything changed while we were away. 6525 */ 6526 ASSERT((sq->sq_flags & SQ_EXCL) || (type & SQ_CIPUT)); 6527 continue; 6528 } 6529 6530 ASSERT(sq->sq_evhead == NULL); 6531 ASSERT(!(sq->sq_flags & SQ_EVENTS)); 6532 6533 /* 6534 * Find the queue that is not draining. 6535 * 6536 * q_draining is protected by QLOCK which we do not hold. 6537 * But if it was set, then a thread was draining, and if it gets 6538 * cleared, then it was because the thread has successfully 6539 * drained the syncq, or a GOAWAY state occurred. For the GOAWAY 6540 * state to happen, a thread needs the SQLOCK which we hold, and 6541 * if there was such a flag, we would have already seen it. 6542 */ 6543 6544 for (qp = sq->sq_head; 6545 qp != NULL && (qp->q_draining || 6546 (qp->q_sqflags & Q_SQDRAINING)); 6547 qp = qp->q_sqnext) 6548 ; 6549 6550 if (qp == NULL) 6551 break; 6552 6553 /* 6554 * We have a queue to work on, and we hold the 6555 * SQLOCK and one claim, call qdrain_syncq. 6556 * This means we need to release the SQLOCK and 6557 * acquire the QLOCK (OK since we have a claim). 6558 * Note that qdrain_syncq will actually dequeue 6559 * this queue from the sq_head list when it is 6560 * convinced all the work is done and release 6561 * the QLOCK before returning. 6562 */ 6563 qp->q_sqflags |= Q_SQDRAINING; 6564 mutex_exit(SQLOCK(sq)); 6565 mutex_enter(QLOCK(qp)); 6566 qdrain_syncq(sq, qp); 6567 mutex_enter(SQLOCK(sq)); 6568 6569 /* The queue is drained */ 6570 ASSERT(qp->q_sqflags & Q_SQDRAINING); 6571 qp->q_sqflags &= ~Q_SQDRAINING; 6572 /* 6573 * NOTE: After this point qp should not be used since it may be 6574 * closed. 6575 */ 6576 } 6577 6578 ASSERT(MUTEX_HELD(SQLOCK(sq))); 6579 flags = sq->sq_flags; 6580 6581 /* 6582 * sq->sq_head cannot change because we hold the 6583 * sqlock. However, a thread CAN decide that it is no longer 6584 * going to drain that queue. However, this should be due to 6585 * a GOAWAY state, and we should see that here. 6586 * 6587 * This loop is not very efficient. One solution may be adding a second 6588 * pointer to the "draining" queue, but it is difficult to do when 6589 * queues are inserted in the middle due to priority ordering. Another 6590 * possibility is to yank the queue out of the sq list and put it onto 6591 * the "draining list" and then put it back if it can't be drained. 6592 */ 6593 6594 ASSERT((sq->sq_head == NULL) || (flags & SQ_GOAWAY) || 6595 (type & SQ_CI) || sq->sq_head->q_draining); 6596 6597 /* Drop SQ_EXCL for non-CIPUT perimeters */ 6598 if (!(type & SQ_CIPUT)) 6599 flags &= ~SQ_EXCL; 6600 ASSERT((flags & SQ_EXCL) == 0); 6601 6602 /* Wake up any waiters. */ 6603 if (flags & SQ_WANTWAKEUP) { 6604 flags &= ~SQ_WANTWAKEUP; 6605 cv_broadcast(&sq->sq_wait); 6606 } 6607 if (flags & SQ_WANTEXWAKEUP) { 6608 flags &= ~SQ_WANTEXWAKEUP; 6609 cv_broadcast(&sq->sq_exitwait); 6610 } 6611 sq->sq_flags = flags; 6612 6613 ASSERT(sq->sq_count != 0); 6614 /* Release our claim. */ 6615 sq->sq_count--; 6616 6617 if (bg_service) { 6618 ASSERT(sq->sq_servcount != 0); 6619 sq->sq_servcount--; 6620 } 6621 6622 mutex_exit(SQLOCK(sq)); 6623 6624 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, 6625 "drain_syncq end:%p", sq); 6626 } 6627 6628 6629 /* 6630 * 6631 * qdrain_syncq can be called (currently) from only one of two places: 6632 * drain_syncq 6633 * putnext (or some variation of it). 6634 * and eventually 6635 * qwait(_sig) 6636 * 6637 * If called from drain_syncq, we found it in the list of queues needing 6638 * service, so there is work to be done (or it wouldn't be in the list). 6639 * 6640 * If called from some putnext variation, it was because the 6641 * perimeter is open, but messages are blocking a putnext and 6642 * there is not a thread working on it. Now a thread could start 6643 * working on it while we are getting ready to do so ourself, but 6644 * the thread would set the q_draining flag, and we can spin out. 6645 * 6646 * As for qwait(_sig), I think I shall let it continue to call 6647 * drain_syncq directly (after all, it will get here eventually). 6648 * 6649 * qdrain_syncq has to terminate when: 6650 * - one of the SQ_STAYAWAY bits gets set to preserve qwriter(OUTER) ordering 6651 * - SQ_EVENTS gets set to preserve qwriter(INNER) ordering 6652 * 6653 * ASSUMES: 6654 * One claim 6655 * QLOCK held 6656 * SQLOCK not held 6657 * Will release QLOCK before returning 6658 */ 6659 void 6660 qdrain_syncq(syncq_t *sq, queue_t *q) 6661 { 6662 mblk_t *bp; 6663 #ifdef DEBUG 6664 uint16_t count; 6665 #endif 6666 6667 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, 6668 "drain_syncq start:%p", sq); 6669 ASSERT(q->q_syncq == sq); 6670 ASSERT(MUTEX_HELD(QLOCK(q))); 6671 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6672 /* 6673 * For non-CIPUT perimeters, we should be called with the exclusive bit 6674 * set already. For CIPUT perimeters, we will be doing a concurrent 6675 * drain, so it better not be set. 6676 */ 6677 ASSERT((sq->sq_flags & (SQ_EXCL|SQ_CIPUT))); 6678 ASSERT(!((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL))); 6679 ASSERT((sq->sq_type & SQ_CIPUT) || (sq->sq_flags & SQ_EXCL)); 6680 /* 6681 * All outer pointers are set, or none of them are 6682 */ 6683 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6684 sq->sq_oprev == NULL) || 6685 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6686 sq->sq_oprev != NULL)); 6687 #ifdef DEBUG 6688 count = sq->sq_count; 6689 /* 6690 * This is OK without the putlocks, because we have one 6691 * claim either from the sq_count, or a putcount. We could 6692 * get an erroneous value from other counts, but ours won't 6693 * change, so one way or another, we will have at least a 6694 * value of one. 6695 */ 6696 SUM_SQ_PUTCOUNTS(sq, count); 6697 ASSERT(count >= 1); 6698 #endif /* DEBUG */ 6699 6700 /* 6701 * The first thing to do is find out if a thread is already draining 6702 * this queue. If so, we are done, just return. 6703 */ 6704 if (q->q_draining) { 6705 mutex_exit(QLOCK(q)); 6706 return; 6707 } 6708 6709 /* 6710 * If the perimeter is exclusive, there is nothing we can do right now, 6711 * go away. Note that there is nothing to prevent this case from 6712 * changing right after this check, but the spin-out will catch it. 6713 */ 6714 6715 /* Tell other threads that we are draining this queue */ 6716 q->q_draining = 1; /* Protected by QLOCK */ 6717 6718 /* 6719 * If there is nothing to do, clear QFULL as necessary. This caters for 6720 * the case where an empty queue was enqueued onto the syncq. 6721 */ 6722 if (q->q_sqhead == NULL) { 6723 ASSERT(q->q_syncqmsgs == 0); 6724 mutex_exit(QLOCK(q)); 6725 clr_qfull(q); 6726 mutex_enter(QLOCK(q)); 6727 } 6728 6729 /* 6730 * Note that q_sqhead must be re-checked here in case another message 6731 * was enqueued whilst QLOCK was dropped during the call to clr_qfull. 6732 */ 6733 for (bp = q->q_sqhead; bp != NULL; bp = q->q_sqhead) { 6734 /* 6735 * Because we can enter this routine just because a putnext is 6736 * blocked, we need to spin out if the perimeter wants to go 6737 * exclusive as well as just blocked. We need to spin out also 6738 * if events are queued on the syncq. 6739 * Don't check for SQ_EXCL, because non-CIPUT perimeters would 6740 * set it, and it can't become exclusive while we hold a claim. 6741 */ 6742 if (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS)) { 6743 break; 6744 } 6745 6746 #ifdef DEBUG 6747 /* 6748 * Since we are in qdrain_syncq, we already know the queue, 6749 * but for sanity, we want to check this against the qp that 6750 * was passed in by bp->b_queue. 6751 */ 6752 6753 ASSERT(bp->b_queue == q); 6754 ASSERT(bp->b_queue->q_syncq == sq); 6755 bp->b_queue = NULL; 6756 6757 /* 6758 * We would have the following check in the DEBUG code: 6759 * 6760 * if (bp->b_prev != NULL) { 6761 * ASSERT(bp->b_prev == (void (*)())q->q_qinfo->qi_putp); 6762 * } 6763 * 6764 * This can't be done, however, since IP modifies qinfo 6765 * structure at run-time (switching between IPv4 qinfo and IPv6 6766 * qinfo), invalidating the check. 6767 * So the assignment to func is left here, but the ASSERT itself 6768 * is removed until the whole issue is resolved. 6769 */ 6770 #endif 6771 ASSERT(q->q_sqhead == bp); 6772 q->q_sqhead = bp->b_next; 6773 bp->b_prev = bp->b_next = NULL; 6774 ASSERT(q->q_syncqmsgs > 0); 6775 mutex_exit(QLOCK(q)); 6776 6777 ASSERT(bp->b_datap->db_ref != 0); 6778 6779 (void) (*q->q_qinfo->qi_putp)(q, bp); 6780 6781 mutex_enter(QLOCK(q)); 6782 6783 /* 6784 * q_syncqmsgs should only be decremented after executing the 6785 * put procedure to avoid message re-ordering. This is due to an 6786 * optimisation in putnext() which can call the put procedure 6787 * directly if it sees q_syncqmsgs == 0 (despite Q_SQQUEUED 6788 * being set). 6789 * 6790 * We also need to clear QFULL in the next service procedure 6791 * queue if this is the last message destined for that queue. 6792 * 6793 * It would make better sense to have some sort of tunable for 6794 * the low water mark, but these semantics are not yet defined. 6795 * So, alas, we use a constant. 6796 */ 6797 if (--q->q_syncqmsgs == 0) { 6798 mutex_exit(QLOCK(q)); 6799 clr_qfull(q); 6800 mutex_enter(QLOCK(q)); 6801 } 6802 6803 /* 6804 * Always clear SQ_EXCL when CIPUT in order to handle 6805 * qwriter(INNER). The putp() can call qwriter and get exclusive 6806 * access IFF this is the only claim. So, we need to test for 6807 * this possibility, acquire the mutex and clear the bit. 6808 */ 6809 if ((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL)) { 6810 mutex_enter(SQLOCK(sq)); 6811 sq->sq_flags &= ~SQ_EXCL; 6812 mutex_exit(SQLOCK(sq)); 6813 } 6814 } 6815 6816 /* 6817 * We should either have no messages on this queue, or we were told to 6818 * goaway by a waiter (which we will wake up at the end of this 6819 * function). 6820 */ 6821 ASSERT((q->q_sqhead == NULL) || 6822 (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS))); 6823 6824 ASSERT(MUTEX_HELD(QLOCK(q))); 6825 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6826 6827 /* Remove the q from the syncq list if all the messages are drained. */ 6828 if (q->q_sqhead == NULL) { 6829 ASSERT(q->q_syncqmsgs == 0); 6830 mutex_enter(SQLOCK(sq)); 6831 if (q->q_sqflags & Q_SQQUEUED) 6832 SQRM_Q(sq, q); 6833 mutex_exit(SQLOCK(sq)); 6834 /* 6835 * Since the queue is removed from the list, reset its priority. 6836 */ 6837 q->q_spri = 0; 6838 } 6839 6840 /* 6841 * Remember, the q_draining flag is used to let another thread know 6842 * that there is a thread currently draining the messages for a queue. 6843 * Since we are now done with this queue (even if there may be messages 6844 * still there), we need to clear this flag so some thread will work on 6845 * it if needed. 6846 */ 6847 ASSERT(q->q_draining); 6848 q->q_draining = 0; 6849 6850 /* Called with a claim, so OK to drop all locks. */ 6851 mutex_exit(QLOCK(q)); 6852 6853 TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, 6854 "drain_syncq end:%p", sq); 6855 } 6856 /* END OF QDRAIN_SYNCQ */ 6857 6858 6859 /* 6860 * This is the mate to qdrain_syncq, except that it is putting the message onto 6861 * the queue instead of draining. Since the message is destined for the queue 6862 * that is selected, there is no need to identify the function because the 6863 * message is intended for the put routine for the queue. For debug kernels, 6864 * this routine will do it anyway just in case. 6865 * 6866 * After the message is enqueued on the syncq, it calls putnext_tail() 6867 * which will schedule a background thread to actually process the message. 6868 * 6869 * Assumes that there is a claim on the syncq (sq->sq_count > 0) and 6870 * SQLOCK(sq) and QLOCK(q) are not held. 6871 */ 6872 void 6873 qfill_syncq(syncq_t *sq, queue_t *q, mblk_t *mp) 6874 { 6875 ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); 6876 ASSERT(MUTEX_NOT_HELD(QLOCK(q))); 6877 ASSERT(sq->sq_count > 0); 6878 ASSERT(q->q_syncq == sq); 6879 ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && 6880 sq->sq_oprev == NULL) || 6881 (sq->sq_outer != NULL && sq->sq_onext != NULL && 6882 sq->sq_oprev != NULL)); 6883 6884 mutex_enter(QLOCK(q)); 6885 6886 #ifdef DEBUG 6887 /* 6888 * This is used for debug in the qfill_syncq/qdrain_syncq case 6889 * to trace the queue that the message is intended for. Note 6890 * that the original use was to identify the queue and function 6891 * to call on the drain. In the new syncq, we have the context 6892 * of the queue that we are draining, so call it's putproc and 6893 * don't rely on the saved values. But for debug this is still 6894 * useful information. 6895 */ 6896 mp->b_prev = (mblk_t *)q->q_qinfo->qi_putp; 6897 mp->b_queue = q; 6898 mp->b_next = NULL; 6899 #endif 6900 ASSERT(q->q_syncq == sq); 6901 /* 6902 * Enqueue the message on the list. 6903 * SQPUT_MP() accesses q_syncqmsgs. We are already holding QLOCK to 6904 * protect it. So it's ok to acquire SQLOCK after SQPUT_MP(). 6905 */ 6906 SQPUT_MP(q, mp); 6907 mutex_enter(SQLOCK(sq)); 6908 6909 /* 6910 * And queue on syncq for scheduling, if not already queued. 6911 * Note that we need the SQLOCK for this, and for testing flags 6912 * at the end to see if we will drain. So grab it now, and 6913 * release it before we call qdrain_syncq or return. 6914 */ 6915 if (!(q->q_sqflags & Q_SQQUEUED)) { 6916 q->q_spri = curthread->t_pri; 6917 SQPUT_Q(sq, q); 6918 } 6919 #ifdef DEBUG 6920 else { 6921 /* 6922 * All of these conditions MUST be true! 6923 */ 6924 ASSERT(sq->sq_tail != NULL); 6925 if (sq->sq_tail == sq->sq_head) { 6926 ASSERT((q->q_sqprev == NULL) && 6927 (q->q_sqnext == NULL)); 6928 } else { 6929 ASSERT((q->q_sqprev != NULL) || 6930 (q->q_sqnext != NULL)); 6931 } 6932 ASSERT(sq->sq_flags & SQ_QUEUED); 6933 ASSERT(q->q_syncqmsgs != 0); 6934 ASSERT(q->q_sqflags & Q_SQQUEUED); 6935 } 6936 #endif 6937 mutex_exit(QLOCK(q)); 6938 /* 6939 * SQLOCK is still held, so sq_count can be safely decremented. 6940 */ 6941 sq->sq_count--; 6942 6943 putnext_tail(sq, q, 0); 6944 /* Should not reference sq or q after this point. */ 6945 } 6946 6947 /* End of qfill_syncq */ 6948 6949 /* 6950 * Remove all messages from a syncq (if qp is NULL) or remove all messages 6951 * that would be put into qp by drain_syncq. 6952 * Used when deleting the syncq (qp == NULL) or when detaching 6953 * a queue (qp != NULL). 6954 * Return non-zero if one or more messages were freed. 6955 * 6956 * No need to grab sq_putlocks here. See comment in strsubr.h that explains when 6957 * sq_putlocks are used. 6958 * 6959 * NOTE: This function assumes that it is called from the close() context and 6960 * that all the queues in the syncq are going away. For this reason it doesn't 6961 * acquire QLOCK for modifying q_sqhead/q_sqtail fields. This assumption is 6962 * currently valid, but it is useful to rethink this function to behave properly 6963 * in other cases. 6964 */ 6965 int 6966 flush_syncq(syncq_t *sq, queue_t *qp) 6967 { 6968 mblk_t *bp, *mp_head, *mp_next, *mp_prev; 6969 queue_t *q; 6970 int ret = 0; 6971 6972 mutex_enter(SQLOCK(sq)); 6973 6974 /* 6975 * Before we leave, we need to make sure there are no 6976 * events listed for this queue. All events for this queue 6977 * will just be freed. 6978 */ 6979 if (qp != NULL && sq->sq_evhead != NULL) { 6980 ASSERT(sq->sq_flags & SQ_EVENTS); 6981 6982 mp_prev = NULL; 6983 for (bp = sq->sq_evhead; bp != NULL; bp = mp_next) { 6984 mp_next = bp->b_next; 6985 if (bp->b_queue == qp) { 6986 /* Delete this message */ 6987 if (mp_prev != NULL) { 6988 mp_prev->b_next = mp_next; 6989 /* 6990 * Update sq_evtail if the last element 6991 * is removed. 6992 */ 6993 if (bp == sq->sq_evtail) { 6994 ASSERT(mp_next == NULL); 6995 sq->sq_evtail = mp_prev; 6996 } 6997 } else 6998 sq->sq_evhead = mp_next; 6999 if (sq->sq_evhead == NULL) 7000 sq->sq_flags &= ~SQ_EVENTS; 7001 bp->b_prev = bp->b_next = NULL; 7002 freemsg(bp); 7003 ret++; 7004 } else { 7005 mp_prev = bp; 7006 } 7007 } 7008 } 7009 7010 /* 7011 * Walk sq_head and: 7012 * - match qp if qp is set, remove it's messages 7013 * - all if qp is not set 7014 */ 7015 q = sq->sq_head; 7016 while (q != NULL) { 7017 ASSERT(q->q_syncq == sq); 7018 if ((qp == NULL) || (qp == q)) { 7019 /* 7020 * Yank the messages as a list off the queue 7021 */ 7022 mp_head = q->q_sqhead; 7023 /* 7024 * We do not have QLOCK(q) here (which is safe due to 7025 * assumptions mentioned above). To obtain the lock we 7026 * need to release SQLOCK which may allow lots of things 7027 * to change upon us. This place requires more analysis. 7028 */ 7029 q->q_sqhead = q->q_sqtail = NULL; 7030 ASSERT(mp_head->b_queue && 7031 mp_head->b_queue->q_syncq == sq); 7032 7033 /* 7034 * Free each of the messages. 7035 */ 7036 for (bp = mp_head; bp != NULL; bp = mp_next) { 7037 mp_next = bp->b_next; 7038 bp->b_prev = bp->b_next = NULL; 7039 freemsg(bp); 7040 ret++; 7041 } 7042 /* 7043 * Now remove the queue from the syncq. 7044 */ 7045 ASSERT(q->q_sqflags & Q_SQQUEUED); 7046 SQRM_Q(sq, q); 7047 q->q_spri = 0; 7048 q->q_syncqmsgs = 0; 7049 7050 /* 7051 * If qp was specified, we are done with it and are 7052 * going to drop SQLOCK(sq) and return. We wakeup syncq 7053 * waiters while we still have the SQLOCK. 7054 */ 7055 if ((qp != NULL) && (sq->sq_flags & SQ_WANTWAKEUP)) { 7056 sq->sq_flags &= ~SQ_WANTWAKEUP; 7057 cv_broadcast(&sq->sq_wait); 7058 } 7059 /* Drop SQLOCK across clr_qfull */ 7060 mutex_exit(SQLOCK(sq)); 7061 7062 /* 7063 * We avoid doing the test that drain_syncq does and 7064 * unconditionally clear qfull for every flushed 7065 * message. Since flush_syncq is only called during 7066 * close this should not be a problem. 7067 */ 7068 clr_qfull(q); 7069 if (qp != NULL) { 7070 return (ret); 7071 } else { 7072 mutex_enter(SQLOCK(sq)); 7073 /* 7074 * The head was removed by SQRM_Q above. 7075 * reread the new head and flush it. 7076 */ 7077 q = sq->sq_head; 7078 } 7079 } else { 7080 q = q->q_sqnext; 7081 } 7082 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7083 } 7084 7085 if (sq->sq_flags & SQ_WANTWAKEUP) { 7086 sq->sq_flags &= ~SQ_WANTWAKEUP; 7087 cv_broadcast(&sq->sq_wait); 7088 } 7089 7090 mutex_exit(SQLOCK(sq)); 7091 return (ret); 7092 } 7093 7094 /* 7095 * Propagate all messages from a syncq to the next syncq that are associated 7096 * with the specified queue. If the queue is attached to a driver or if the 7097 * messages have been added due to a qwriter(PERIM_INNER), free the messages. 7098 * 7099 * Assumes that the stream is strlock()'ed. We don't come here if there 7100 * are no messages to propagate. 7101 * 7102 * NOTE : If the queue is attached to a driver, all the messages are freed 7103 * as there is no point in propagating the messages from the driver syncq 7104 * to the closing stream head which will in turn get freed later. 7105 */ 7106 static int 7107 propagate_syncq(queue_t *qp) 7108 { 7109 mblk_t *bp, *head, *tail, *prev, *next; 7110 syncq_t *sq; 7111 queue_t *nqp; 7112 syncq_t *nsq; 7113 boolean_t isdriver; 7114 int moved = 0; 7115 uint16_t flags; 7116 pri_t priority = curthread->t_pri; 7117 #ifdef DEBUG 7118 void (*func)(); 7119 #endif 7120 7121 sq = qp->q_syncq; 7122 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7123 /* debug macro */ 7124 SQ_PUTLOCKS_HELD(sq); 7125 /* 7126 * As entersq() does not increment the sq_count for 7127 * the write side, check sq_count for non-QPERQ 7128 * perimeters alone. 7129 */ 7130 ASSERT((qp->q_flag & QPERQ) || (sq->sq_count >= 1)); 7131 7132 /* 7133 * propagate_syncq() can be called because of either messages on the 7134 * queue syncq or because on events on the queue syncq. Do actual 7135 * message propagations if there are any messages. 7136 */ 7137 if (qp->q_syncqmsgs) { 7138 isdriver = (qp->q_flag & QISDRV); 7139 7140 if (!isdriver) { 7141 nqp = qp->q_next; 7142 nsq = nqp->q_syncq; 7143 ASSERT(MUTEX_HELD(SQLOCK(nsq))); 7144 /* debug macro */ 7145 SQ_PUTLOCKS_HELD(nsq); 7146 #ifdef DEBUG 7147 func = (void (*)())(uintptr_t)nqp->q_qinfo->qi_putp; 7148 #endif 7149 } 7150 7151 SQRM_Q(sq, qp); 7152 priority = MAX(qp->q_spri, priority); 7153 qp->q_spri = 0; 7154 head = qp->q_sqhead; 7155 tail = qp->q_sqtail; 7156 qp->q_sqhead = qp->q_sqtail = NULL; 7157 qp->q_syncqmsgs = 0; 7158 7159 /* 7160 * Walk the list of messages, and free them if this is a driver, 7161 * otherwise reset the b_prev and b_queue value to the new putp. 7162 * Afterward, we will just add the head to the end of the next 7163 * syncq, and point the tail to the end of this one. 7164 */ 7165 7166 for (bp = head; bp != NULL; bp = next) { 7167 next = bp->b_next; 7168 if (isdriver) { 7169 bp->b_prev = bp->b_next = NULL; 7170 freemsg(bp); 7171 continue; 7172 } 7173 /* Change the q values for this message */ 7174 bp->b_queue = nqp; 7175 #ifdef DEBUG 7176 bp->b_prev = (mblk_t *)func; 7177 #endif 7178 moved++; 7179 } 7180 /* 7181 * Attach list of messages to the end of the new queue (if there 7182 * is a list of messages). 7183 */ 7184 7185 if (!isdriver && head != NULL) { 7186 ASSERT(tail != NULL); 7187 if (nqp->q_sqhead == NULL) { 7188 nqp->q_sqhead = head; 7189 } else { 7190 ASSERT(nqp->q_sqtail != NULL); 7191 nqp->q_sqtail->b_next = head; 7192 } 7193 nqp->q_sqtail = tail; 7194 /* 7195 * When messages are moved from high priority queue to 7196 * another queue, the destination queue priority is 7197 * upgraded. 7198 */ 7199 7200 if (priority > nqp->q_spri) 7201 nqp->q_spri = priority; 7202 7203 SQPUT_Q(nsq, nqp); 7204 7205 nqp->q_syncqmsgs += moved; 7206 ASSERT(nqp->q_syncqmsgs != 0); 7207 } 7208 } 7209 7210 /* 7211 * Before we leave, we need to make sure there are no 7212 * events listed for this queue. All events for this queue 7213 * will just be freed. 7214 */ 7215 if (sq->sq_evhead != NULL) { 7216 ASSERT(sq->sq_flags & SQ_EVENTS); 7217 prev = NULL; 7218 for (bp = sq->sq_evhead; bp != NULL; bp = next) { 7219 next = bp->b_next; 7220 if (bp->b_queue == qp) { 7221 /* Delete this message */ 7222 if (prev != NULL) { 7223 prev->b_next = next; 7224 /* 7225 * Update sq_evtail if the last element 7226 * is removed. 7227 */ 7228 if (bp == sq->sq_evtail) { 7229 ASSERT(next == NULL); 7230 sq->sq_evtail = prev; 7231 } 7232 } else 7233 sq->sq_evhead = next; 7234 if (sq->sq_evhead == NULL) 7235 sq->sq_flags &= ~SQ_EVENTS; 7236 bp->b_prev = bp->b_next = NULL; 7237 freemsg(bp); 7238 } else { 7239 prev = bp; 7240 } 7241 } 7242 } 7243 7244 flags = sq->sq_flags; 7245 7246 /* Wake up any waiter before leaving. */ 7247 if (flags & SQ_WANTWAKEUP) { 7248 flags &= ~SQ_WANTWAKEUP; 7249 cv_broadcast(&sq->sq_wait); 7250 } 7251 sq->sq_flags = flags; 7252 7253 return (moved); 7254 } 7255 7256 /* 7257 * Try and upgrade to exclusive access at the inner perimeter. If this can 7258 * not be done without blocking then request will be queued on the syncq 7259 * and drain_syncq will run it later. 7260 * 7261 * This routine can only be called from put or service procedures plus 7262 * asynchronous callback routines that have properly entered the queue (with 7263 * entersq). Thus qwriter_inner assumes the caller has one claim on the syncq 7264 * associated with q. 7265 */ 7266 void 7267 qwriter_inner(queue_t *q, mblk_t *mp, void (*func)()) 7268 { 7269 syncq_t *sq = q->q_syncq; 7270 uint16_t count; 7271 7272 mutex_enter(SQLOCK(sq)); 7273 count = sq->sq_count; 7274 SQ_PUTLOCKS_ENTER(sq); 7275 SUM_SQ_PUTCOUNTS(sq, count); 7276 ASSERT(count >= 1); 7277 ASSERT(sq->sq_type & (SQ_CIPUT|SQ_CISVC)); 7278 7279 if (count == 1) { 7280 /* 7281 * Can upgrade. This case also handles nested qwriter calls 7282 * (when the qwriter callback function calls qwriter). In that 7283 * case SQ_EXCL is already set. 7284 */ 7285 sq->sq_flags |= SQ_EXCL; 7286 SQ_PUTLOCKS_EXIT(sq); 7287 mutex_exit(SQLOCK(sq)); 7288 (*func)(q, mp); 7289 /* 7290 * Assumes that leavesq, putnext, and drain_syncq will reset 7291 * SQ_EXCL for SQ_CIPUT/SQ_CISVC queues. We leave SQ_EXCL on 7292 * until putnext, leavesq, or drain_syncq drops it. 7293 * That way we handle nested qwriter(INNER) without dropping 7294 * SQ_EXCL until the outermost qwriter callback routine is 7295 * done. 7296 */ 7297 return; 7298 } 7299 SQ_PUTLOCKS_EXIT(sq); 7300 sqfill_events(sq, q, mp, func); 7301 } 7302 7303 /* 7304 * Synchronous callback support functions 7305 */ 7306 7307 /* 7308 * Allocate a callback parameter structure. 7309 * Assumes that caller initializes the flags and the id. 7310 * Acquires SQLOCK(sq) if non-NULL is returned. 7311 */ 7312 callbparams_t * 7313 callbparams_alloc(syncq_t *sq, void (*func)(void *), void *arg, int kmflags) 7314 { 7315 callbparams_t *cbp; 7316 size_t size = sizeof (callbparams_t); 7317 7318 cbp = kmem_alloc(size, kmflags & ~KM_PANIC); 7319 7320 /* 7321 * Only try tryhard allocation if the caller is ready to panic. 7322 * Otherwise just fail. 7323 */ 7324 if (cbp == NULL) { 7325 if (kmflags & KM_PANIC) 7326 cbp = kmem_alloc_tryhard(sizeof (callbparams_t), 7327 &size, kmflags); 7328 else 7329 return (NULL); 7330 } 7331 7332 ASSERT(size >= sizeof (callbparams_t)); 7333 cbp->cbp_size = size; 7334 cbp->cbp_sq = sq; 7335 cbp->cbp_func = func; 7336 cbp->cbp_arg = arg; 7337 mutex_enter(SQLOCK(sq)); 7338 cbp->cbp_next = sq->sq_callbpend; 7339 sq->sq_callbpend = cbp; 7340 return (cbp); 7341 } 7342 7343 void 7344 callbparams_free(syncq_t *sq, callbparams_t *cbp) 7345 { 7346 callbparams_t **pp, *p; 7347 7348 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7349 7350 for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { 7351 if (p == cbp) { 7352 *pp = p->cbp_next; 7353 kmem_free(p, p->cbp_size); 7354 return; 7355 } 7356 } 7357 (void) (STRLOG(0, 0, 0, SL_CONSOLE, 7358 "callbparams_free: not found\n")); 7359 } 7360 7361 void 7362 callbparams_free_id(syncq_t *sq, callbparams_id_t id, int32_t flag) 7363 { 7364 callbparams_t **pp, *p; 7365 7366 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7367 7368 for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { 7369 if (p->cbp_id == id && p->cbp_flags == flag) { 7370 *pp = p->cbp_next; 7371 kmem_free(p, p->cbp_size); 7372 return; 7373 } 7374 } 7375 (void) (STRLOG(0, 0, 0, SL_CONSOLE, 7376 "callbparams_free_id: not found\n")); 7377 } 7378 7379 /* 7380 * Callback wrapper function used by once-only callbacks that can be 7381 * cancelled (qtimeout and qbufcall) 7382 * Contains inline version of entersq(sq, SQ_CALLBACK) that can be 7383 * cancelled by the qun* functions. 7384 */ 7385 void 7386 qcallbwrapper(void *arg) 7387 { 7388 callbparams_t *cbp = arg; 7389 syncq_t *sq; 7390 uint16_t count = 0; 7391 uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; 7392 uint16_t type; 7393 7394 sq = cbp->cbp_sq; 7395 mutex_enter(SQLOCK(sq)); 7396 type = sq->sq_type; 7397 if (!(type & SQ_CICB)) { 7398 count = sq->sq_count; 7399 SQ_PUTLOCKS_ENTER(sq); 7400 SQ_PUTCOUNT_CLRFAST_LOCKED(sq); 7401 SUM_SQ_PUTCOUNTS(sq, count); 7402 sq->sq_needexcl++; 7403 ASSERT(sq->sq_needexcl != 0); /* wraparound */ 7404 waitflags |= SQ_MESSAGES; 7405 } 7406 /* Can not handle exclusive entry at outer perimeter */ 7407 ASSERT(type & SQ_COCB); 7408 7409 while ((sq->sq_flags & waitflags) || (!(type & SQ_CICB) &&count != 0)) { 7410 if ((sq->sq_callbflags & cbp->cbp_flags) && 7411 (sq->sq_cancelid == cbp->cbp_id)) { 7412 /* timeout has been cancelled */ 7413 sq->sq_callbflags |= SQ_CALLB_BYPASSED; 7414 callbparams_free(sq, cbp); 7415 if (!(type & SQ_CICB)) { 7416 ASSERT(sq->sq_needexcl > 0); 7417 sq->sq_needexcl--; 7418 if (sq->sq_needexcl == 0) { 7419 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 7420 } 7421 SQ_PUTLOCKS_EXIT(sq); 7422 } 7423 mutex_exit(SQLOCK(sq)); 7424 return; 7425 } 7426 sq->sq_flags |= SQ_WANTWAKEUP; 7427 if (!(type & SQ_CICB)) { 7428 SQ_PUTLOCKS_EXIT(sq); 7429 } 7430 cv_wait(&sq->sq_wait, SQLOCK(sq)); 7431 if (!(type & SQ_CICB)) { 7432 count = sq->sq_count; 7433 SQ_PUTLOCKS_ENTER(sq); 7434 SUM_SQ_PUTCOUNTS(sq, count); 7435 } 7436 } 7437 7438 sq->sq_count++; 7439 ASSERT(sq->sq_count != 0); /* Wraparound */ 7440 if (!(type & SQ_CICB)) { 7441 ASSERT(count == 0); 7442 sq->sq_flags |= SQ_EXCL; 7443 ASSERT(sq->sq_needexcl > 0); 7444 sq->sq_needexcl--; 7445 if (sq->sq_needexcl == 0) { 7446 SQ_PUTCOUNT_SETFAST_LOCKED(sq); 7447 } 7448 SQ_PUTLOCKS_EXIT(sq); 7449 } 7450 7451 mutex_exit(SQLOCK(sq)); 7452 7453 cbp->cbp_func(cbp->cbp_arg); 7454 7455 /* 7456 * We drop the lock only for leavesq to re-acquire it. 7457 * Possible optimization is inline of leavesq. 7458 */ 7459 mutex_enter(SQLOCK(sq)); 7460 callbparams_free(sq, cbp); 7461 mutex_exit(SQLOCK(sq)); 7462 leavesq(sq, SQ_CALLBACK); 7463 } 7464 7465 /* 7466 * No need to grab sq_putlocks here. See comment in strsubr.h that 7467 * explains when sq_putlocks are used. 7468 * 7469 * sq_count (or one of the sq_putcounts) has already been 7470 * decremented by the caller, and if SQ_QUEUED, we need to call 7471 * drain_syncq (the global syncq drain). 7472 * If putnext_tail is called with the SQ_EXCL bit set, we are in 7473 * one of two states, non-CIPUT perimeter, and we need to clear 7474 * it, or we went exclusive in the put procedure. In any case, 7475 * we want to clear the bit now, and it is probably easier to do 7476 * this at the beginning of this function (remember, we hold 7477 * the SQLOCK). Lastly, if there are other messages queued 7478 * on the syncq (and not for our destination), enable the syncq 7479 * for background work. 7480 */ 7481 7482 /* ARGSUSED */ 7483 void 7484 putnext_tail(syncq_t *sq, queue_t *qp, uint32_t passflags) 7485 { 7486 uint16_t flags = sq->sq_flags; 7487 7488 ASSERT(MUTEX_HELD(SQLOCK(sq))); 7489 ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); 7490 7491 /* Clear SQ_EXCL if set in passflags */ 7492 if (passflags & SQ_EXCL) { 7493 flags &= ~SQ_EXCL; 7494 } 7495 if (flags & SQ_WANTWAKEUP) { 7496 flags &= ~SQ_WANTWAKEUP; 7497 cv_broadcast(&sq->sq_wait); 7498 } 7499 if (flags & SQ_WANTEXWAKEUP) { 7500 flags &= ~SQ_WANTEXWAKEUP; 7501 cv_broadcast(&sq->sq_exitwait); 7502 } 7503 sq->sq_flags = flags; 7504 7505 /* 7506 * We have cleared SQ_EXCL if we were asked to, and started 7507 * the wakeup process for waiters. If there are no writers 7508 * then we need to drain the syncq if we were told to, or 7509 * enable the background thread to do it. 7510 */ 7511 if (!(flags & (SQ_STAYAWAY|SQ_EXCL))) { 7512 if ((passflags & SQ_QUEUED) || 7513 (sq->sq_svcflags & SQ_DISABLED)) { 7514 /* drain_syncq will take care of events in the list */ 7515 drain_syncq(sq); 7516 return; 7517 } else if (flags & SQ_QUEUED) { 7518 sqenable(sq); 7519 } 7520 } 7521 /* Drop the SQLOCK on exit */ 7522 mutex_exit(SQLOCK(sq)); 7523 TRACE_3(TR_FAC_STREAMS_FR, TR_PUTNEXT_END, 7524 "putnext_end:(%p, %p, %p) done", NULL, qp, sq); 7525 } 7526 7527 void 7528 set_qend(queue_t *q) 7529 { 7530 mutex_enter(QLOCK(q)); 7531 if (!O_SAMESTR(q)) 7532 q->q_flag |= QEND; 7533 else 7534 q->q_flag &= ~QEND; 7535 mutex_exit(QLOCK(q)); 7536 q = _OTHERQ(q); 7537 mutex_enter(QLOCK(q)); 7538 if (!O_SAMESTR(q)) 7539 q->q_flag |= QEND; 7540 else 7541 q->q_flag &= ~QEND; 7542 mutex_exit(QLOCK(q)); 7543 } 7544 7545 /* 7546 * Set QFULL in next service procedure queue (that cares) if not already 7547 * set and if there are already more messages on the syncq than 7548 * sq_max_size. If sq_max_size is 0, no flow control will be asserted on 7549 * any syncq. 7550 * 7551 * The fq here is the next queue with a service procedure. This is where 7552 * we would fail canputnext, so this is where we need to set QFULL. 7553 * In the case when fq != q we need to take QLOCK(fq) to set QFULL flag. 7554 * 7555 * We already have QLOCK at this point. To avoid cross-locks with 7556 * freezestr() which grabs all QLOCKs and with strlock() which grabs both 7557 * SQLOCK and sd_reflock, we need to drop respective locks first. 7558 */ 7559 void 7560 set_qfull(queue_t *q) 7561 { 7562 queue_t *fq = NULL; 7563 7564 ASSERT(MUTEX_HELD(QLOCK(q))); 7565 if ((sq_max_size != 0) && (!(q->q_nfsrv->q_flag & QFULL)) && 7566 (q->q_syncqmsgs > sq_max_size)) { 7567 if ((fq = q->q_nfsrv) == q) { 7568 fq->q_flag |= QFULL; 7569 } else { 7570 mutex_exit(QLOCK(q)); 7571 mutex_enter(QLOCK(fq)); 7572 fq->q_flag |= QFULL; 7573 mutex_exit(QLOCK(fq)); 7574 mutex_enter(QLOCK(q)); 7575 } 7576 } 7577 } 7578 7579 void 7580 clr_qfull(queue_t *q) 7581 { 7582 queue_t *oq = q; 7583 7584 q = q->q_nfsrv; 7585 /* Fast check if there is any work to do before getting the lock. */ 7586 if ((q->q_flag & (QFULL|QWANTW)) == 0) { 7587 return; 7588 } 7589 7590 /* 7591 * Do not reset QFULL (and backenable) if the q_count is the reason 7592 * for QFULL being set. 7593 */ 7594 mutex_enter(QLOCK(q)); 7595 /* 7596 * If queue is empty i.e q_mblkcnt is zero, queue can not be full. 7597 * Hence clear the QFULL. 7598 * If both q_count and q_mblkcnt are less than the hiwat mark, 7599 * clear the QFULL. 7600 */ 7601 if (q->q_mblkcnt == 0 || ((q->q_count < q->q_hiwat) && 7602 (q->q_mblkcnt < q->q_hiwat))) { 7603 q->q_flag &= ~QFULL; 7604 /* 7605 * A little more confusing, how about this way: 7606 * if someone wants to write, 7607 * AND 7608 * both counts are less than the lowat mark 7609 * OR 7610 * the lowat mark is zero 7611 * THEN 7612 * backenable 7613 */ 7614 if ((q->q_flag & QWANTW) && 7615 (((q->q_count < q->q_lowat) && 7616 (q->q_mblkcnt < q->q_lowat)) || q->q_lowat == 0)) { 7617 q->q_flag &= ~QWANTW; 7618 mutex_exit(QLOCK(q)); 7619 backenable(oq, 0); 7620 } else 7621 mutex_exit(QLOCK(q)); 7622 } else 7623 mutex_exit(QLOCK(q)); 7624 } 7625 7626 /* 7627 * Set the forward service procedure pointer. 7628 * 7629 * Called at insert-time to cache a queue's next forward service procedure in 7630 * q_nfsrv; used by canput() and canputnext(). If the queue to be inserted 7631 * has a service procedure then q_nfsrv points to itself. If the queue to be 7632 * inserted does not have a service procedure, then q_nfsrv points to the next 7633 * queue forward that has a service procedure. If the queue is at the logical 7634 * end of the stream (driver for write side, stream head for the read side) 7635 * and does not have a service procedure, then q_nfsrv also points to itself. 7636 */ 7637 void 7638 set_nfsrv_ptr( 7639 queue_t *rnew, /* read queue pointer to new module */ 7640 queue_t *wnew, /* write queue pointer to new module */ 7641 queue_t *prev_rq, /* read queue pointer to the module above */ 7642 queue_t *prev_wq) /* write queue pointer to the module above */ 7643 { 7644 queue_t *qp; 7645 7646 if (prev_wq->q_next == NULL) { 7647 /* 7648 * Insert the driver, initialize the driver and stream head. 7649 * In this case, prev_rq/prev_wq should be the stream head. 7650 * _I_INSERT does not allow inserting a driver. Make sure 7651 * that it is not an insertion. 7652 */ 7653 ASSERT(!(rnew->q_flag & _QINSERTING)); 7654 wnew->q_nfsrv = wnew; 7655 if (rnew->q_qinfo->qi_srvp) 7656 rnew->q_nfsrv = rnew; 7657 else 7658 rnew->q_nfsrv = prev_rq; 7659 prev_rq->q_nfsrv = prev_rq; 7660 prev_wq->q_nfsrv = prev_wq; 7661 } else { 7662 /* 7663 * set up read side q_nfsrv pointer. This MUST be done 7664 * before setting the write side, because the setting of 7665 * the write side for a fifo may depend on it. 7666 * 7667 * Suppose we have a fifo that only has pipemod pushed. 7668 * pipemod has no read or write service procedures, so 7669 * nfsrv for both pipemod queues points to prev_rq (the 7670 * stream read head). Now push bufmod (which has only a 7671 * read service procedure). Doing the write side first, 7672 * wnew->q_nfsrv is set to pipemod's writeq nfsrv, which 7673 * is WRONG; the next queue forward from wnew with a 7674 * service procedure will be rnew, not the stream read head. 7675 * Since the downstream queue (which in the case of a fifo 7676 * is the read queue rnew) can affect upstream queues, it 7677 * needs to be done first. Setting up the read side first 7678 * sets nfsrv for both pipemod queues to rnew and then 7679 * when the write side is set up, wnew-q_nfsrv will also 7680 * point to rnew. 7681 */ 7682 if (rnew->q_qinfo->qi_srvp) { 7683 /* 7684 * use _OTHERQ() because, if this is a pipe, next 7685 * module may have been pushed from other end and 7686 * q_next could be a read queue. 7687 */ 7688 qp = _OTHERQ(prev_wq->q_next); 7689 while (qp && qp->q_nfsrv != qp) { 7690 qp->q_nfsrv = rnew; 7691 qp = backq(qp); 7692 } 7693 rnew->q_nfsrv = rnew; 7694 } else 7695 rnew->q_nfsrv = prev_rq->q_nfsrv; 7696 7697 /* set up write side q_nfsrv pointer */ 7698 if (wnew->q_qinfo->qi_srvp) { 7699 wnew->q_nfsrv = wnew; 7700 7701 /* 7702 * For insertion, need to update nfsrv of the modules 7703 * above which do not have a service routine. 7704 */ 7705 if (rnew->q_flag & _QINSERTING) { 7706 for (qp = prev_wq; 7707 qp != NULL && qp->q_nfsrv != qp; 7708 qp = backq(qp)) { 7709 qp->q_nfsrv = wnew->q_nfsrv; 7710 } 7711 } 7712 } else { 7713 if (prev_wq->q_next == prev_rq) 7714 /* 7715 * Since prev_wq/prev_rq are the middle of a 7716 * fifo, wnew/rnew will also be the middle of 7717 * a fifo and wnew's nfsrv is same as rnew's. 7718 */ 7719 wnew->q_nfsrv = rnew->q_nfsrv; 7720 else 7721 wnew->q_nfsrv = prev_wq->q_next->q_nfsrv; 7722 } 7723 } 7724 } 7725 7726 /* 7727 * Reset the forward service procedure pointer; called at remove-time. 7728 */ 7729 void 7730 reset_nfsrv_ptr(queue_t *rqp, queue_t *wqp) 7731 { 7732 queue_t *tmp_qp; 7733 7734 /* Reset the write side q_nfsrv pointer for _I_REMOVE */ 7735 if ((rqp->q_flag & _QREMOVING) && (wqp->q_qinfo->qi_srvp != NULL)) { 7736 for (tmp_qp = backq(wqp); 7737 tmp_qp != NULL && tmp_qp->q_nfsrv == wqp; 7738 tmp_qp = backq(tmp_qp)) { 7739 tmp_qp->q_nfsrv = wqp->q_nfsrv; 7740 } 7741 } 7742 7743 /* reset the read side q_nfsrv pointer */ 7744 if (rqp->q_qinfo->qi_srvp) { 7745 if (wqp->q_next) { /* non-driver case */ 7746 tmp_qp = _OTHERQ(wqp->q_next); 7747 while (tmp_qp && tmp_qp->q_nfsrv == rqp) { 7748 /* Note that rqp->q_next cannot be NULL */ 7749 ASSERT(rqp->q_next != NULL); 7750 tmp_qp->q_nfsrv = rqp->q_next->q_nfsrv; 7751 tmp_qp = backq(tmp_qp); 7752 } 7753 } 7754 } 7755 } 7756 7757 /* 7758 * This routine should be called after all stream geometry changes to update 7759 * the stream head cached struio() rd/wr queue pointers. Note must be called 7760 * with the streamlock()ed. 7761 * 7762 * Note: only enables Synchronous STREAMS for a side of a Stream which has 7763 * an explicit synchronous barrier module queue. That is, a queue that 7764 * has specified a struio() type. 7765 */ 7766 static void 7767 strsetuio(stdata_t *stp) 7768 { 7769 queue_t *wrq; 7770 7771 if (stp->sd_flag & STPLEX) { 7772 /* 7773 * Not streamhead, but a mux, so no Synchronous STREAMS. 7774 */ 7775 stp->sd_struiowrq = NULL; 7776 stp->sd_struiordq = NULL; 7777 return; 7778 } 7779 /* 7780 * Scan the write queue(s) while synchronous 7781 * until we find a qinfo uio type specified. 7782 */ 7783 wrq = stp->sd_wrq->q_next; 7784 while (wrq) { 7785 if (wrq->q_struiot == STRUIOT_NONE) { 7786 wrq = 0; 7787 break; 7788 } 7789 if (wrq->q_struiot != STRUIOT_DONTCARE) 7790 break; 7791 if (! _SAMESTR(wrq)) { 7792 wrq = 0; 7793 break; 7794 } 7795 wrq = wrq->q_next; 7796 } 7797 stp->sd_struiowrq = wrq; 7798 /* 7799 * Scan the read queue(s) while synchronous 7800 * until we find a qinfo uio type specified. 7801 */ 7802 wrq = stp->sd_wrq->q_next; 7803 while (wrq) { 7804 if (_RD(wrq)->q_struiot == STRUIOT_NONE) { 7805 wrq = 0; 7806 break; 7807 } 7808 if (_RD(wrq)->q_struiot != STRUIOT_DONTCARE) 7809 break; 7810 if (! _SAMESTR(wrq)) { 7811 wrq = 0; 7812 break; 7813 } 7814 wrq = wrq->q_next; 7815 } 7816 stp->sd_struiordq = wrq ? _RD(wrq) : 0; 7817 } 7818 7819 static int 7820 pass_rput(queue_t *q, mblk_t *mp) 7821 { 7822 putnext(q, mp); 7823 return (0); 7824 } 7825 7826 /* 7827 * pass_wput, unblocks the passthru queues, so that 7828 * messages can arrive at muxs lower read queue, before 7829 * I_LINK/I_UNLINK is acked/nacked. 7830 */ 7831 static int 7832 pass_wput(queue_t *q, mblk_t *mp) 7833 { 7834 syncq_t *sq; 7835 7836 sq = _RD(q)->q_syncq; 7837 if (sq->sq_flags & SQ_BLOCKED) 7838 unblocksq(sq, SQ_BLOCKED, 0); 7839 putnext(q, mp); 7840 return (0); 7841 } 7842 7843 /* 7844 * Set up queues for the link/unlink. 7845 * Create a new queue and block it and then insert it 7846 * below the stream head on the lower stream. 7847 * This prevents any messages from arriving during the setq 7848 * as well as while the mux is processing the LINK/I_UNLINK. 7849 * The blocked passq is unblocked once the LINK/I_UNLINK has 7850 * been acked or nacked or if a message is generated and sent 7851 * down muxs write put procedure. 7852 * See pass_wput(). 7853 * 7854 * After the new queue is inserted, all messages coming from below are 7855 * blocked. The call to strlock will ensure that all activity in the stream head 7856 * read queue syncq is stopped (sq_count drops to zero). 7857 */ 7858 static queue_t * 7859 link_addpassthru(stdata_t *stpdown) 7860 { 7861 queue_t *passq; 7862 sqlist_t sqlist; 7863 7864 passq = allocq(); 7865 STREAM(passq) = STREAM(_WR(passq)) = stpdown; 7866 /* setq might sleep in allocator - avoid holding locks. */ 7867 setq(passq, &passthru_rinit, &passthru_winit, NULL, QPERQ, 7868 SQ_CI|SQ_CO, B_FALSE); 7869 claimq(passq); 7870 blocksq(passq->q_syncq, SQ_BLOCKED, 1); 7871 insertq(STREAM(passq), passq); 7872 7873 /* 7874 * Use strlock() to wait for the stream head sq_count to drop to zero 7875 * since we are going to change q_ptr in the stream head. Note that 7876 * insertq() doesn't wait for any syncq counts to drop to zero. 7877 */ 7878 sqlist.sqlist_head = NULL; 7879 sqlist.sqlist_index = 0; 7880 sqlist.sqlist_size = sizeof (sqlist_t); 7881 sqlist_insert(&sqlist, _RD(stpdown->sd_wrq)->q_syncq); 7882 strlock(stpdown, &sqlist); 7883 strunlock(stpdown, &sqlist); 7884 7885 releaseq(passq); 7886 return (passq); 7887 } 7888 7889 /* 7890 * Let messages flow up into the mux by removing 7891 * the passq. 7892 */ 7893 static void 7894 link_rempassthru(queue_t *passq) 7895 { 7896 claimq(passq); 7897 removeq(passq); 7898 releaseq(passq); 7899 freeq(passq); 7900 } 7901 7902 /* 7903 * Wait for the condition variable pointed to by `cvp' to be signaled, 7904 * or for `tim' milliseconds to elapse, whichever comes first. If `tim' 7905 * is negative, then there is no time limit. If `nosigs' is non-zero, 7906 * then the wait will be non-interruptible. 7907 * 7908 * Returns >0 if signaled, 0 if interrupted, or -1 upon timeout. 7909 */ 7910 clock_t 7911 str_cv_wait(kcondvar_t *cvp, kmutex_t *mp, clock_t tim, int nosigs) 7912 { 7913 clock_t ret; 7914 7915 if (tim < 0) { 7916 if (nosigs) { 7917 cv_wait(cvp, mp); 7918 ret = 1; 7919 } else { 7920 ret = cv_wait_sig(cvp, mp); 7921 } 7922 } else if (tim > 0) { 7923 /* 7924 * convert milliseconds to clock ticks 7925 */ 7926 if (nosigs) { 7927 ret = cv_reltimedwait(cvp, mp, 7928 MSEC_TO_TICK_ROUNDUP(tim), TR_CLOCK_TICK); 7929 } else { 7930 ret = cv_reltimedwait_sig(cvp, mp, 7931 MSEC_TO_TICK_ROUNDUP(tim), TR_CLOCK_TICK); 7932 } 7933 } else { 7934 ret = -1; 7935 } 7936 return (ret); 7937 } 7938 7939 /* 7940 * Wait until the stream head can determine if it is at the mark but 7941 * don't wait forever to prevent a race condition between the "mark" state 7942 * in the stream head and any mark state in the caller/user of this routine. 7943 * 7944 * This is used by sockets and for a socket it would be incorrect 7945 * to return a failure for SIOCATMARK when there is no data in the receive 7946 * queue and the marked urgent data is traveling up the stream. 7947 * 7948 * This routine waits until the mark is known by waiting for one of these 7949 * three events: 7950 * The stream head read queue becoming non-empty (including an EOF). 7951 * The STRATMARK flag being set (due to a MSGMARKNEXT message). 7952 * The STRNOTATMARK flag being set (which indicates that the transport 7953 * has sent a MSGNOTMARKNEXT message to indicate that it is not at 7954 * the mark). 7955 * 7956 * The routine returns 1 if the stream is at the mark; 0 if it can 7957 * be determined that the stream is not at the mark. 7958 * If the wait times out and it can't determine 7959 * whether or not the stream might be at the mark the routine will return -1. 7960 * 7961 * Note: This routine should only be used when a mark is pending i.e., 7962 * in the socket case the SIGURG has been posted. 7963 * Note2: This can not wakeup just because synchronous streams indicate 7964 * that data is available since it is not possible to use the synchronous 7965 * streams interfaces to determine the b_flag value for the data queued below 7966 * the stream head. 7967 */ 7968 int 7969 strwaitmark(vnode_t *vp) 7970 { 7971 struct stdata *stp = vp->v_stream; 7972 queue_t *rq = _RD(stp->sd_wrq); 7973 int mark; 7974 7975 mutex_enter(&stp->sd_lock); 7976 while (rq->q_first == NULL && 7977 !(stp->sd_flag & (STRATMARK|STRNOTATMARK|STREOF))) { 7978 stp->sd_flag |= RSLEEP; 7979 7980 /* Wait for 100 milliseconds for any state change. */ 7981 if (str_cv_wait(&rq->q_wait, &stp->sd_lock, 100, 1) == -1) { 7982 mutex_exit(&stp->sd_lock); 7983 return (-1); 7984 } 7985 } 7986 if (stp->sd_flag & STRATMARK) 7987 mark = 1; 7988 else if (rq->q_first != NULL && (rq->q_first->b_flag & MSGMARK)) 7989 mark = 1; 7990 else 7991 mark = 0; 7992 7993 mutex_exit(&stp->sd_lock); 7994 return (mark); 7995 } 7996 7997 /* 7998 * Set a read side error. If persist is set change the socket error 7999 * to persistent. If errfunc is set install the function as the exported 8000 * error handler. 8001 */ 8002 void 8003 strsetrerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) 8004 { 8005 struct stdata *stp = vp->v_stream; 8006 8007 mutex_enter(&stp->sd_lock); 8008 stp->sd_rerror = error; 8009 if (error == 0 && errfunc == NULL) 8010 stp->sd_flag &= ~STRDERR; 8011 else 8012 stp->sd_flag |= STRDERR; 8013 if (persist) { 8014 stp->sd_flag &= ~STRDERRNONPERSIST; 8015 } else { 8016 stp->sd_flag |= STRDERRNONPERSIST; 8017 } 8018 stp->sd_rderrfunc = errfunc; 8019 if (error != 0 || errfunc != NULL) { 8020 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ 8021 cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ 8022 cv_broadcast(&stp->sd_monitor); /* ioctllers */ 8023 8024 mutex_exit(&stp->sd_lock); 8025 pollwakeup(&stp->sd_pollist, POLLERR); 8026 mutex_enter(&stp->sd_lock); 8027 8028 if (stp->sd_sigflags & S_ERROR) 8029 strsendsig(stp->sd_siglist, S_ERROR, 0, error); 8030 } 8031 mutex_exit(&stp->sd_lock); 8032 } 8033 8034 /* 8035 * Set a write side error. If persist is set change the socket error 8036 * to persistent. 8037 */ 8038 void 8039 strsetwerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) 8040 { 8041 struct stdata *stp = vp->v_stream; 8042 8043 mutex_enter(&stp->sd_lock); 8044 stp->sd_werror = error; 8045 if (error == 0 && errfunc == NULL) 8046 stp->sd_flag &= ~STWRERR; 8047 else 8048 stp->sd_flag |= STWRERR; 8049 if (persist) { 8050 stp->sd_flag &= ~STWRERRNONPERSIST; 8051 } else { 8052 stp->sd_flag |= STWRERRNONPERSIST; 8053 } 8054 stp->sd_wrerrfunc = errfunc; 8055 if (error != 0 || errfunc != NULL) { 8056 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ 8057 cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ 8058 cv_broadcast(&stp->sd_monitor); /* ioctllers */ 8059 8060 mutex_exit(&stp->sd_lock); 8061 pollwakeup(&stp->sd_pollist, POLLERR); 8062 mutex_enter(&stp->sd_lock); 8063 8064 if (stp->sd_sigflags & S_ERROR) 8065 strsendsig(stp->sd_siglist, S_ERROR, 0, error); 8066 } 8067 mutex_exit(&stp->sd_lock); 8068 } 8069 8070 /* 8071 * Make the stream return 0 (EOF) when all data has been read. 8072 * No effect on write side. 8073 */ 8074 void 8075 strseteof(vnode_t *vp, int eof) 8076 { 8077 struct stdata *stp = vp->v_stream; 8078 8079 mutex_enter(&stp->sd_lock); 8080 if (!eof) { 8081 stp->sd_flag &= ~STREOF; 8082 mutex_exit(&stp->sd_lock); 8083 return; 8084 } 8085 stp->sd_flag |= STREOF; 8086 if (stp->sd_flag & RSLEEP) { 8087 stp->sd_flag &= ~RSLEEP; 8088 cv_broadcast(&_RD(stp->sd_wrq)->q_wait); 8089 } 8090 8091 mutex_exit(&stp->sd_lock); 8092 pollwakeup(&stp->sd_pollist, POLLIN|POLLRDNORM); 8093 mutex_enter(&stp->sd_lock); 8094 8095 if (stp->sd_sigflags & (S_INPUT|S_RDNORM)) 8096 strsendsig(stp->sd_siglist, S_INPUT|S_RDNORM, 0, 0); 8097 mutex_exit(&stp->sd_lock); 8098 } 8099 8100 void 8101 strflushrq(vnode_t *vp, int flag) 8102 { 8103 struct stdata *stp = vp->v_stream; 8104 8105 mutex_enter(&stp->sd_lock); 8106 flushq(_RD(stp->sd_wrq), flag); 8107 mutex_exit(&stp->sd_lock); 8108 } 8109 8110 void 8111 strsetrputhooks(vnode_t *vp, uint_t flags, 8112 msgfunc_t protofunc, msgfunc_t miscfunc) 8113 { 8114 struct stdata *stp = vp->v_stream; 8115 8116 mutex_enter(&stp->sd_lock); 8117 8118 if (protofunc == NULL) 8119 stp->sd_rprotofunc = strrput_proto; 8120 else 8121 stp->sd_rprotofunc = protofunc; 8122 8123 if (miscfunc == NULL) 8124 stp->sd_rmiscfunc = strrput_misc; 8125 else 8126 stp->sd_rmiscfunc = miscfunc; 8127 8128 if (flags & SH_CONSOL_DATA) 8129 stp->sd_rput_opt |= SR_CONSOL_DATA; 8130 else 8131 stp->sd_rput_opt &= ~SR_CONSOL_DATA; 8132 8133 if (flags & SH_SIGALLDATA) 8134 stp->sd_rput_opt |= SR_SIGALLDATA; 8135 else 8136 stp->sd_rput_opt &= ~SR_SIGALLDATA; 8137 8138 if (flags & SH_IGN_ZEROLEN) 8139 stp->sd_rput_opt |= SR_IGN_ZEROLEN; 8140 else 8141 stp->sd_rput_opt &= ~SR_IGN_ZEROLEN; 8142 8143 mutex_exit(&stp->sd_lock); 8144 } 8145 8146 void 8147 strsetwputhooks(vnode_t *vp, uint_t flags, clock_t closetime) 8148 { 8149 struct stdata *stp = vp->v_stream; 8150 8151 mutex_enter(&stp->sd_lock); 8152 stp->sd_closetime = closetime; 8153 8154 if (flags & SH_SIGPIPE) 8155 stp->sd_wput_opt |= SW_SIGPIPE; 8156 else 8157 stp->sd_wput_opt &= ~SW_SIGPIPE; 8158 if (flags & SH_RECHECK_ERR) 8159 stp->sd_wput_opt |= SW_RECHECK_ERR; 8160 else 8161 stp->sd_wput_opt &= ~SW_RECHECK_ERR; 8162 8163 mutex_exit(&stp->sd_lock); 8164 } 8165 8166 void 8167 strsetrwputdatahooks(vnode_t *vp, msgfunc_t rdatafunc, msgfunc_t wdatafunc) 8168 { 8169 struct stdata *stp = vp->v_stream; 8170 8171 mutex_enter(&stp->sd_lock); 8172 8173 stp->sd_rputdatafunc = rdatafunc; 8174 stp->sd_wputdatafunc = wdatafunc; 8175 8176 mutex_exit(&stp->sd_lock); 8177 } 8178 8179 /* Used within framework when the queue is already locked */ 8180 void 8181 qenable_locked(queue_t *q) 8182 { 8183 stdata_t *stp = STREAM(q); 8184 8185 ASSERT(MUTEX_HELD(QLOCK(q))); 8186 8187 if (!q->q_qinfo->qi_srvp) 8188 return; 8189 8190 /* 8191 * Do not place on run queue if already enabled or closing. 8192 */ 8193 if (q->q_flag & (QWCLOSE|QENAB)) 8194 return; 8195 8196 /* 8197 * mark queue enabled and place on run list if it is not already being 8198 * serviced. If it is serviced, the runservice() function will detect 8199 * that QENAB is set and call service procedure before clearing 8200 * QINSERVICE flag. 8201 */ 8202 q->q_flag |= QENAB; 8203 if (q->q_flag & QINSERVICE) 8204 return; 8205 8206 /* Record the time of qenable */ 8207 q->q_qtstamp = ddi_get_lbolt(); 8208 8209 /* 8210 * Put the queue in the stp list and schedule it for background 8211 * processing if it is not already scheduled or if stream head does not 8212 * intent to process it in the foreground later by setting 8213 * STRS_WILLSERVICE flag. 8214 */ 8215 mutex_enter(&stp->sd_qlock); 8216 /* 8217 * If there are already something on the list, stp flags should show 8218 * intention to drain it. 8219 */ 8220 IMPLY(STREAM_NEEDSERVICE(stp), 8221 (stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))); 8222 8223 ENQUEUE(q, stp->sd_qhead, stp->sd_qtail, q_link); 8224 stp->sd_nqueues++; 8225 8226 /* 8227 * If no one will drain this stream we are the first producer and 8228 * need to schedule it for background thread. 8229 */ 8230 if (!(stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))) { 8231 /* 8232 * No one will service this stream later, so we have to 8233 * schedule it now. 8234 */ 8235 STRSTAT(stenables); 8236 stp->sd_svcflags |= STRS_SCHEDULED; 8237 stp->sd_servid = (void *)taskq_dispatch(streams_taskq, 8238 (task_func_t *)stream_service, stp, TQ_NOSLEEP|TQ_NOQUEUE); 8239 8240 if (stp->sd_servid == NULL) { 8241 /* 8242 * Task queue failed so fail over to the backup 8243 * servicing thread. 8244 */ 8245 STRSTAT(taskqfails); 8246 /* 8247 * It is safe to clear STRS_SCHEDULED flag because it 8248 * was set by this thread above. 8249 */ 8250 stp->sd_svcflags &= ~STRS_SCHEDULED; 8251 8252 /* 8253 * Failover scheduling is protected by service_queue 8254 * lock. 8255 */ 8256 mutex_enter(&service_queue); 8257 ASSERT((stp->sd_qhead == q) && (stp->sd_qtail == q)); 8258 ASSERT(q->q_link == NULL); 8259 /* 8260 * Append the queue to qhead/qtail list. 8261 */ 8262 if (qhead == NULL) 8263 qhead = q; 8264 else 8265 qtail->q_link = q; 8266 qtail = q; 8267 /* 8268 * Clear stp queue list. 8269 */ 8270 stp->sd_qhead = stp->sd_qtail = NULL; 8271 stp->sd_nqueues = 0; 8272 /* 8273 * Wakeup background queue processing thread. 8274 */ 8275 cv_signal(&services_to_run); 8276 mutex_exit(&service_queue); 8277 } 8278 } 8279 mutex_exit(&stp->sd_qlock); 8280 } 8281 8282 static void 8283 queue_service(queue_t *q) 8284 { 8285 /* 8286 * The queue in the list should have 8287 * QENAB flag set and should not have 8288 * QINSERVICE flag set. QINSERVICE is 8289 * set when the queue is dequeued and 8290 * qenable_locked doesn't enqueue a 8291 * queue with QINSERVICE set. 8292 */ 8293 8294 ASSERT(!(q->q_flag & QINSERVICE)); 8295 ASSERT((q->q_flag & QENAB)); 8296 mutex_enter(QLOCK(q)); 8297 q->q_flag &= ~QENAB; 8298 q->q_flag |= QINSERVICE; 8299 mutex_exit(QLOCK(q)); 8300 runservice(q); 8301 } 8302 8303 static void 8304 syncq_service(syncq_t *sq) 8305 { 8306 STRSTAT(syncqservice); 8307 mutex_enter(SQLOCK(sq)); 8308 ASSERT(!(sq->sq_svcflags & SQ_SERVICE)); 8309 ASSERT(sq->sq_servcount != 0); 8310 ASSERT(sq->sq_next == NULL); 8311 8312 /* if we came here from the background thread, clear the flag */ 8313 if (sq->sq_svcflags & SQ_BGTHREAD) 8314 sq->sq_svcflags &= ~SQ_BGTHREAD; 8315 8316 /* let drain_syncq know that it's being called in the background */ 8317 sq->sq_svcflags |= SQ_SERVICE; 8318 drain_syncq(sq); 8319 } 8320 8321 static void 8322 qwriter_outer_service(syncq_t *outer) 8323 { 8324 /* 8325 * Note that SQ_WRITER is used on the outer perimeter 8326 * to signal that a qwriter(OUTER) is either investigating 8327 * running or that it is actually running a function. 8328 */ 8329 outer_enter(outer, SQ_BLOCKED|SQ_WRITER); 8330 8331 /* 8332 * All inner syncq are empty and have SQ_WRITER set 8333 * to block entering the outer perimeter. 8334 * 8335 * We do not need to explicitly call write_now since 8336 * outer_exit does it for us. 8337 */ 8338 outer_exit(outer); 8339 } 8340 8341 static void 8342 mblk_free(mblk_t *mp) 8343 { 8344 dblk_t *dbp = mp->b_datap; 8345 frtn_t *frp = dbp->db_frtnp; 8346 8347 mp->b_next = NULL; 8348 if (dbp->db_fthdr != NULL) 8349 str_ftfree(dbp); 8350 8351 ASSERT(dbp->db_fthdr == NULL); 8352 frp->free_func(frp->free_arg); 8353 ASSERT(dbp->db_mblk == mp); 8354 8355 if (dbp->db_credp != NULL) { 8356 crfree(dbp->db_credp); 8357 dbp->db_credp = NULL; 8358 } 8359 dbp->db_cpid = -1; 8360 dbp->db_struioflag = 0; 8361 dbp->db_struioun.cksum.flags = 0; 8362 8363 kmem_cache_free(dbp->db_cache, dbp); 8364 } 8365 8366 /* 8367 * Background processing of the stream queue list. 8368 */ 8369 static void 8370 stream_service(stdata_t *stp) 8371 { 8372 queue_t *q; 8373 8374 mutex_enter(&stp->sd_qlock); 8375 8376 STR_SERVICE(stp, q); 8377 8378 stp->sd_svcflags &= ~STRS_SCHEDULED; 8379 stp->sd_servid = NULL; 8380 cv_signal(&stp->sd_qcv); 8381 mutex_exit(&stp->sd_qlock); 8382 } 8383 8384 /* 8385 * Foreground processing of the stream queue list. 8386 */ 8387 void 8388 stream_runservice(stdata_t *stp) 8389 { 8390 queue_t *q; 8391 8392 mutex_enter(&stp->sd_qlock); 8393 STRSTAT(rservice); 8394 /* 8395 * We are going to drain this stream queue list, so qenable_locked will 8396 * not schedule it until we finish. 8397 */ 8398 stp->sd_svcflags |= STRS_WILLSERVICE; 8399 8400 STR_SERVICE(stp, q); 8401 8402 stp->sd_svcflags &= ~STRS_WILLSERVICE; 8403 mutex_exit(&stp->sd_qlock); 8404 /* 8405 * Help backup background thread to drain the qhead/qtail list. 8406 */ 8407 while (qhead != NULL) { 8408 STRSTAT(qhelps); 8409 mutex_enter(&service_queue); 8410 DQ(q, qhead, qtail, q_link); 8411 mutex_exit(&service_queue); 8412 if (q != NULL) 8413 queue_service(q); 8414 } 8415 } 8416 8417 void 8418 stream_willservice(stdata_t *stp) 8419 { 8420 mutex_enter(&stp->sd_qlock); 8421 stp->sd_svcflags |= STRS_WILLSERVICE; 8422 mutex_exit(&stp->sd_qlock); 8423 } 8424 8425 /* 8426 * Replace the cred currently in the mblk with a different one. 8427 * Also update db_cpid. 8428 */ 8429 void 8430 mblk_setcred(mblk_t *mp, cred_t *cr, pid_t cpid) 8431 { 8432 dblk_t *dbp = mp->b_datap; 8433 cred_t *ocr = dbp->db_credp; 8434 8435 ASSERT(cr != NULL); 8436 8437 if (cr != ocr) { 8438 crhold(dbp->db_credp = cr); 8439 if (ocr != NULL) 8440 crfree(ocr); 8441 } 8442 /* Don't overwrite with NOPID */ 8443 if (cpid != NOPID) 8444 dbp->db_cpid = cpid; 8445 } 8446 8447 /* 8448 * If the src message has a cred, then replace the cred currently in the mblk 8449 * with it. 8450 * Also update db_cpid. 8451 */ 8452 void 8453 mblk_copycred(mblk_t *mp, const mblk_t *src) 8454 { 8455 dblk_t *dbp = mp->b_datap; 8456 cred_t *cr, *ocr; 8457 pid_t cpid; 8458 8459 cr = msg_getcred(src, &cpid); 8460 if (cr == NULL) 8461 return; 8462 8463 ocr = dbp->db_credp; 8464 if (cr != ocr) { 8465 crhold(dbp->db_credp = cr); 8466 if (ocr != NULL) 8467 crfree(ocr); 8468 } 8469 /* Don't overwrite with NOPID */ 8470 if (cpid != NOPID) 8471 dbp->db_cpid = cpid; 8472 } 8473 8474 8475 /* 8476 * Now that NIC drivers are expected to deal only with M_DATA mblks, the 8477 * hcksum_assoc and hcksum_retrieve functions are deprecated in favor of their 8478 * respective mac_hcksum_set and mac_hcksum_get counterparts. 8479 */ 8480 int 8481 hcksum_assoc(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, 8482 uint32_t start, uint32_t stuff, uint32_t end, uint32_t value, 8483 uint32_t flags, int km_flags) 8484 { 8485 int rc = 0; 8486 8487 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8488 if (mp->b_datap->db_type == M_DATA) { 8489 /* Associate values for M_DATA type */ 8490 DB_CKSUMSTART(mp) = (intptr_t)start; 8491 DB_CKSUMSTUFF(mp) = (intptr_t)stuff; 8492 DB_CKSUMEND(mp) = (intptr_t)end; 8493 DB_CKSUMFLAGS(mp) = flags; 8494 DB_CKSUM16(mp) = (uint16_t)value; 8495 8496 } else { 8497 pattrinfo_t pa_info; 8498 8499 ASSERT(mmd != NULL); 8500 8501 pa_info.type = PATTR_HCKSUM; 8502 pa_info.len = sizeof (pattr_hcksum_t); 8503 8504 if (mmd_addpattr(mmd, pd, &pa_info, B_TRUE, km_flags) != NULL) { 8505 pattr_hcksum_t *hck = (pattr_hcksum_t *)pa_info.buf; 8506 8507 hck->hcksum_start_offset = start; 8508 hck->hcksum_stuff_offset = stuff; 8509 hck->hcksum_end_offset = end; 8510 hck->hcksum_cksum_val.inet_cksum = (uint16_t)value; 8511 hck->hcksum_flags = flags; 8512 } else { 8513 rc = -1; 8514 } 8515 } 8516 return (rc); 8517 } 8518 8519 void 8520 hcksum_retrieve(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, 8521 uint32_t *start, uint32_t *stuff, uint32_t *end, 8522 uint32_t *value, uint32_t *flags) 8523 { 8524 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8525 if (mp->b_datap->db_type == M_DATA) { 8526 if (flags != NULL) { 8527 *flags = DB_CKSUMFLAGS(mp) & HCK_FLAGS; 8528 if ((*flags & (HCK_PARTIALCKSUM | 8529 HCK_FULLCKSUM)) != 0) { 8530 if (value != NULL) 8531 *value = (uint32_t)DB_CKSUM16(mp); 8532 if ((*flags & HCK_PARTIALCKSUM) != 0) { 8533 if (start != NULL) 8534 *start = 8535 (uint32_t)DB_CKSUMSTART(mp); 8536 if (stuff != NULL) 8537 *stuff = 8538 (uint32_t)DB_CKSUMSTUFF(mp); 8539 if (end != NULL) 8540 *end = 8541 (uint32_t)DB_CKSUMEND(mp); 8542 } 8543 } 8544 } 8545 } else { 8546 pattrinfo_t hck_attr = {PATTR_HCKSUM}; 8547 8548 ASSERT(mmd != NULL); 8549 8550 /* get hardware checksum attribute */ 8551 if (mmd_getpattr(mmd, pd, &hck_attr) != NULL) { 8552 pattr_hcksum_t *hck = (pattr_hcksum_t *)hck_attr.buf; 8553 8554 ASSERT(hck_attr.len >= sizeof (pattr_hcksum_t)); 8555 if (flags != NULL) 8556 *flags = hck->hcksum_flags; 8557 if (start != NULL) 8558 *start = hck->hcksum_start_offset; 8559 if (stuff != NULL) 8560 *stuff = hck->hcksum_stuff_offset; 8561 if (end != NULL) 8562 *end = hck->hcksum_end_offset; 8563 if (value != NULL) 8564 *value = (uint32_t) 8565 hck->hcksum_cksum_val.inet_cksum; 8566 } 8567 } 8568 } 8569 8570 void 8571 lso_info_set(mblk_t *mp, uint32_t mss, uint32_t flags) 8572 { 8573 ASSERT(DB_TYPE(mp) == M_DATA); 8574 ASSERT((flags & ~HW_LSO_FLAGS) == 0); 8575 8576 /* Set the flags */ 8577 DB_LSOFLAGS(mp) |= flags; 8578 DB_LSOMSS(mp) = mss; 8579 } 8580 8581 void 8582 lso_info_cleanup(mblk_t *mp) 8583 { 8584 ASSERT(DB_TYPE(mp) == M_DATA); 8585 8586 /* Clear the flags */ 8587 DB_LSOFLAGS(mp) &= ~HW_LSO_FLAGS; 8588 DB_LSOMSS(mp) = 0; 8589 } 8590 8591 /* 8592 * Checksum buffer *bp for len bytes with psum partial checksum, 8593 * or 0 if none, and return the 16 bit partial checksum. 8594 */ 8595 unsigned 8596 bcksum(uchar_t *bp, int len, unsigned int psum) 8597 { 8598 int odd = len & 1; 8599 extern unsigned int ip_ocsum(); 8600 8601 if (((intptr_t)bp & 1) == 0 && !odd) { 8602 /* 8603 * Bp is 16 bit aligned and len is multiple of 16 bit word. 8604 */ 8605 return (ip_ocsum((ushort_t *)bp, len >> 1, psum)); 8606 } 8607 if (((intptr_t)bp & 1) != 0) { 8608 /* 8609 * Bp isn't 16 bit aligned. 8610 */ 8611 unsigned int tsum; 8612 8613 #ifdef _LITTLE_ENDIAN 8614 psum += *bp; 8615 #else 8616 psum += *bp << 8; 8617 #endif 8618 len--; 8619 bp++; 8620 tsum = ip_ocsum((ushort_t *)bp, len >> 1, 0); 8621 psum += (tsum << 8) & 0xffff | (tsum >> 8); 8622 if (len & 1) { 8623 bp += len - 1; 8624 #ifdef _LITTLE_ENDIAN 8625 psum += *bp << 8; 8626 #else 8627 psum += *bp; 8628 #endif 8629 } 8630 } else { 8631 /* 8632 * Bp is 16 bit aligned. 8633 */ 8634 psum = ip_ocsum((ushort_t *)bp, len >> 1, psum); 8635 if (odd) { 8636 bp += len - 1; 8637 #ifdef _LITTLE_ENDIAN 8638 psum += *bp; 8639 #else 8640 psum += *bp << 8; 8641 #endif 8642 } 8643 } 8644 /* 8645 * Normalize psum to 16 bits before returning the new partial 8646 * checksum. The max psum value before normalization is 0x3FDFE. 8647 */ 8648 return ((psum >> 16) + (psum & 0xFFFF)); 8649 } 8650 8651 boolean_t 8652 is_vmloaned_mblk(mblk_t *mp, multidata_t *mmd, pdesc_t *pd) 8653 { 8654 boolean_t rc; 8655 8656 ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); 8657 if (DB_TYPE(mp) == M_DATA) { 8658 rc = (((mp)->b_datap->db_struioflag & STRUIO_ZC) != 0); 8659 } else { 8660 pattrinfo_t zcopy_attr = {PATTR_ZCOPY}; 8661 8662 ASSERT(mmd != NULL); 8663 rc = (mmd_getpattr(mmd, pd, &zcopy_attr) != NULL); 8664 } 8665 return (rc); 8666 } 8667 8668 void 8669 freemsgchain(mblk_t *mp) 8670 { 8671 mblk_t *next; 8672 8673 while (mp != NULL) { 8674 next = mp->b_next; 8675 mp->b_next = NULL; 8676 8677 freemsg(mp); 8678 mp = next; 8679 } 8680 } 8681 8682 mblk_t * 8683 copymsgchain(mblk_t *mp) 8684 { 8685 mblk_t *nmp = NULL; 8686 mblk_t **nmpp = &nmp; 8687 8688 for (; mp != NULL; mp = mp->b_next) { 8689 if ((*nmpp = copymsg(mp)) == NULL) { 8690 freemsgchain(nmp); 8691 return (NULL); 8692 } 8693 8694 nmpp = &((*nmpp)->b_next); 8695 } 8696 8697 return (nmp); 8698 } 8699 8700 /* NOTE: Do not add code after this point. */ 8701 #undef QLOCK 8702 8703 /* 8704 * Replacement for QLOCK macro for those that can't use it. 8705 */ 8706 kmutex_t * 8707 QLOCK(queue_t *q) 8708 { 8709 return (&(q)->q_lock); 8710 } 8711 8712 /* 8713 * Dummy runqueues/queuerun functions functions for backwards compatibility. 8714 */ 8715 #undef runqueues 8716 void 8717 runqueues(void) 8718 { 8719 } 8720 8721 #undef queuerun 8722 void 8723 queuerun(void) 8724 { 8725 } 8726 8727 /* 8728 * Initialize the STR stack instance, which tracks autopush and persistent 8729 * links. 8730 */ 8731 /* ARGSUSED */ 8732 static void * 8733 str_stack_init(netstackid_t stackid, netstack_t *ns) 8734 { 8735 str_stack_t *ss; 8736 int i; 8737 8738 ss = (str_stack_t *)kmem_zalloc(sizeof (*ss), KM_SLEEP); 8739 ss->ss_netstack = ns; 8740 8741 /* 8742 * set up autopush 8743 */ 8744 sad_initspace(ss); 8745 8746 /* 8747 * set up mux_node structures. 8748 */ 8749 ss->ss_devcnt = devcnt; /* In case it should change before free */ 8750 ss->ss_mux_nodes = kmem_zalloc((sizeof (struct mux_node) * 8751 ss->ss_devcnt), KM_SLEEP); 8752 for (i = 0; i < ss->ss_devcnt; i++) 8753 ss->ss_mux_nodes[i].mn_imaj = i; 8754 return (ss); 8755 } 8756 8757 /* 8758 * Note: run at zone shutdown and not destroy so that the PLINKs are 8759 * gone by the time other cleanup happens from the destroy callbacks. 8760 */ 8761 static void 8762 str_stack_shutdown(netstackid_t stackid, void *arg) 8763 { 8764 str_stack_t *ss = (str_stack_t *)arg; 8765 int i; 8766 cred_t *cr; 8767 8768 cr = zone_get_kcred(netstackid_to_zoneid(stackid)); 8769 ASSERT(cr != NULL); 8770 8771 /* Undo all the I_PLINKs for this zone */ 8772 for (i = 0; i < ss->ss_devcnt; i++) { 8773 struct mux_edge *ep; 8774 ldi_handle_t lh; 8775 ldi_ident_t li; 8776 int ret; 8777 int rval; 8778 dev_t rdev; 8779 8780 ep = ss->ss_mux_nodes[i].mn_outp; 8781 if (ep == NULL) 8782 continue; 8783 ret = ldi_ident_from_major((major_t)i, &li); 8784 if (ret != 0) { 8785 continue; 8786 } 8787 rdev = ep->me_dev; 8788 ret = ldi_open_by_dev(&rdev, OTYP_CHR, FREAD|FWRITE, 8789 cr, &lh, li); 8790 if (ret != 0) { 8791 ldi_ident_release(li); 8792 continue; 8793 } 8794 8795 ret = ldi_ioctl(lh, I_PUNLINK, (intptr_t)MUXID_ALL, FKIOCTL, 8796 cr, &rval); 8797 if (ret) { 8798 (void) ldi_close(lh, FREAD|FWRITE, cr); 8799 ldi_ident_release(li); 8800 continue; 8801 } 8802 (void) ldi_close(lh, FREAD|FWRITE, cr); 8803 8804 /* Close layered handles */ 8805 ldi_ident_release(li); 8806 } 8807 crfree(cr); 8808 8809 sad_freespace(ss); 8810 8811 kmem_free(ss->ss_mux_nodes, sizeof (struct mux_node) * ss->ss_devcnt); 8812 ss->ss_mux_nodes = NULL; 8813 } 8814 8815 /* 8816 * Free the structure; str_stack_shutdown did the other cleanup work. 8817 */ 8818 /* ARGSUSED */ 8819 static void 8820 str_stack_fini(netstackid_t stackid, void *arg) 8821 { 8822 str_stack_t *ss = (str_stack_t *)arg; 8823 8824 kmem_free(ss, sizeof (*ss)); 8825 } 8826