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