/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License, Version 1.0 only * (the "License"). You may not use this file except in compliance * with the License. * * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE * or http://www.opensolaris.org/os/licensing. * See the License for the specific language governing permissions * and limitations under the License. * * When distributing Covered Code, include this CDDL HEADER in each * file and include the License file at usr/src/OPENSOLARIS.LICENSE. * If applicable, add the following below this CDDL HEADER, with the * fields enclosed by brackets "[]" replaced with your own identifying * information: Portions Copyright [yyyy] [name of copyright owner] * * CDDL HEADER END */ /* Copyright (c) 1984, 1986, 1987, 1988, 1989 AT&T */ /* All Rights Reserved */ /* * Copyright 2005 Sun Microsystems, Inc. All rights reserved. * Use is subject to license terms. */ #pragma ident "%Z%%M% %I% %E% SMI" #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #include #define O_SAMESTR(q) (((q)->q_next) && \ (((q)->q_flag & QREADR) == ((q)->q_next->q_flag & QREADR))) /* * WARNING: * The variables and routines in this file are private, belonging * to the STREAMS subsystem. These should not be used by modules * or drivers. Compatibility will not be guaranteed. */ /* * Id value used to distinguish between different multiplexor links. */ static int32_t lnk_id = 0; #define STREAMS_LOPRI MINCLSYSPRI static pri_t streams_lopri = STREAMS_LOPRI; #define STRSTAT(x) (str_statistics.x.value.ui64++) typedef struct str_stat { kstat_named_t sqenables; kstat_named_t stenables; kstat_named_t syncqservice; kstat_named_t freebs; kstat_named_t qwr_outer; kstat_named_t rservice; kstat_named_t strwaits; kstat_named_t taskqfails; kstat_named_t bufcalls; kstat_named_t qhelps; kstat_named_t qremoved; kstat_named_t sqremoved; kstat_named_t bcwaits; kstat_named_t sqtoomany; } str_stat_t; static str_stat_t str_statistics = { { "sqenables", KSTAT_DATA_UINT64 }, { "stenables", KSTAT_DATA_UINT64 }, { "syncqservice", KSTAT_DATA_UINT64 }, { "freebs", KSTAT_DATA_UINT64 }, { "qwr_outer", KSTAT_DATA_UINT64 }, { "rservice", KSTAT_DATA_UINT64 }, { "strwaits", KSTAT_DATA_UINT64 }, { "taskqfails", KSTAT_DATA_UINT64 }, { "bufcalls", KSTAT_DATA_UINT64 }, { "qhelps", KSTAT_DATA_UINT64 }, { "qremoved", KSTAT_DATA_UINT64 }, { "sqremoved", KSTAT_DATA_UINT64 }, { "bcwaits", KSTAT_DATA_UINT64 }, { "sqtoomany", KSTAT_DATA_UINT64 }, }; static kstat_t *str_kstat; /* * qrunflag was used previously to control background scheduling of queues. It * is not used anymore, but kept here in case some module still wants to access * it via qready() and setqsched macros. */ char qrunflag; /* Unused */ /* * Most of the streams scheduling is done via task queues. Task queues may fail * for non-sleep dispatches, so there are two backup threads servicing failed * requests for queues and syncqs. Both of these threads also service failed * dispatches freebs requests. Queues are put in the list specified by `qhead' * and `qtail' pointers, syncqs use `sqhead' and `sqtail' pointers and freebs * requests are put into `freebs_list' which has no tail pointer. All three * lists are protected by a single `service_queue' lock and use * `services_to_run' condition variable for signaling background threads. Use of * a single lock should not be a problem because it is only used under heavy * loads when task queues start to fail and at that time it may be a good idea * to throttle scheduling requests. * * NOTE: queues and syncqs should be scheduled by two separate threads because * queue servicing may be blocked waiting for a syncq which may be also * scheduled for background execution. This may create a deadlock when only one * thread is used for both. */ static taskq_t *streams_taskq; /* Used for most STREAMS scheduling */ static kmutex_t service_queue; /* protects all of servicing vars */ static kcondvar_t services_to_run; /* wake up background service thread */ static kcondvar_t syncqs_to_run; /* wake up background service thread */ /* * List of queues scheduled for background processing dueue to lack of resources * in the task queues. Protected by service_queue lock; */ static struct queue *qhead; static struct queue *qtail; /* * Same list for syncqs */ static syncq_t *sqhead; static syncq_t *sqtail; static mblk_t *freebs_list; /* list of buffers to free */ /* * Backup threads for servicing queues and syncqs */ kthread_t *streams_qbkgrnd_thread; kthread_t *streams_sqbkgrnd_thread; /* * Bufcalls related variables. */ struct bclist strbcalls; /* list of waiting bufcalls */ kmutex_t strbcall_lock; /* protects bufcall list (strbcalls) */ kcondvar_t strbcall_cv; /* Signaling when a bufcall is added */ kmutex_t bcall_monitor; /* sleep/wakeup style monitor */ kcondvar_t bcall_cv; /* wait 'till executing bufcall completes */ kthread_t *bc_bkgrnd_thread; /* Thread to service bufcall requests */ kmutex_t strresources; /* protects global resources */ kmutex_t muxifier; /* single-threads multiplexor creation */ extern void time_to_wait(clock_t *, clock_t); /* * run_queues is no longer used, but is kept in case some 3-d party * module/driver decides to use it. */ int run_queues = 0; /* * sq_max_size is the depth of the syncq (in number of messages) before * qfill_syncq() starts QFULL'ing destination queues. As its primary * consumer - IP is no longer D_MTPERMOD, but there may be other * modules/drivers depend on this syncq flow control, we prefer to * choose a large number as the default value. For potential * performance gain, this value is tunable in /etc/system. */ int sq_max_size = 10000; /* * the number of ciputctrl structures per syncq and stream we create when * needed. */ int n_ciputctrl; int max_n_ciputctrl = 16; /* * if n_ciputctrl is < min_n_ciputctrl don't even create ciputctrl_cache. */ int min_n_ciputctrl = 2; static struct mux_node *mux_nodes; /* mux info for cycle checking */ /* * Per-driver/module syncqs * ======================== * * For drivers/modules that use PERMOD or outer syncqs we keep a list of * perdm structures, new entries being added (and new syncqs allocated) when * setq() encounters a module/driver with a streamtab that it hasn't seen * before. * The reason for this mechanism is that some modules and drivers share a * common streamtab and it is necessary for those modules and drivers to also * share a common PERMOD syncq. * * perdm_list --> dm_str == streamtab_1 * dm_sq == syncq_1 * dm_ref * dm_next --> dm_str == streamtab_2 * dm_sq == syncq_2 * dm_ref * dm_next --> ... NULL * * The dm_ref field is incremented for each new driver/module that takes * a reference to the perdm structure and hence shares the syncq. * References are held in the fmodsw_impl_t structure for each STREAMS module * or the dev_impl array (indexed by device major number) for each driver. * * perdm_list -> [dm_ref == 1] -> [dm_ref == 2] -> [dm_ref == 1] -> NULL * ^ ^ ^ ^ * | ______________/ | | * | / | | * dev_impl: ...|x|y|... module A module B * * When a module/driver is unloaded the reference count is decremented and, * when it falls to zero, the perdm structure is removed from the list and * the syncq is freed (see rele_dm()). */ perdm_t *perdm_list = NULL; static krwlock_t perdm_rwlock; cdevsw_impl_t *devimpl; extern struct qinit strdata; extern struct qinit stwdata; static void runservice(queue_t *); static void streams_bufcall_service(void); static void streams_qbkgrnd_service(void); static void streams_sqbkgrnd_service(void); static syncq_t *new_syncq(void); static void free_syncq(syncq_t *); static void outer_insert(syncq_t *, syncq_t *); static void outer_remove(syncq_t *, syncq_t *); static void write_now(syncq_t *); static void clr_qfull(queue_t *); static void enable_svc(queue_t *); static void runbufcalls(void); static void sqenable(syncq_t *); static void sqfill_events(syncq_t *, queue_t *, mblk_t *, void (*)()); static void wait_q_syncq(queue_t *); static void backenable_insertedq(queue_t *); static void queue_service(queue_t *); static void stream_service(stdata_t *); static void syncq_service(syncq_t *); static void qwriter_outer_service(syncq_t *); static void mblk_free(mblk_t *); #ifdef DEBUG static int qprocsareon(queue_t *); #endif static void set_nfsrv_ptr(queue_t *, queue_t *, queue_t *, queue_t *); static void reset_nfsrv_ptr(queue_t *, queue_t *); static void sq_run_events(syncq_t *); static int propagate_syncq(queue_t *); static void blocksq(syncq_t *, ushort_t, int); static void unblocksq(syncq_t *, ushort_t, int); static int dropsq(syncq_t *, uint16_t); static void emptysq(syncq_t *); static sqlist_t *sqlist_alloc(struct stdata *, int); static void sqlist_free(sqlist_t *); static sqlist_t *sqlist_build(queue_t *, struct stdata *, boolean_t); static void sqlist_insert(sqlist_t *, syncq_t *); static void sqlist_insertall(sqlist_t *, queue_t *); static void strsetuio(stdata_t *); struct kmem_cache *stream_head_cache; struct kmem_cache *queue_cache; struct kmem_cache *syncq_cache; struct kmem_cache *qband_cache; struct kmem_cache *linkinfo_cache; struct kmem_cache *ciputctrl_cache = NULL; static linkinfo_t *linkinfo_list; /* * Qinit structure and Module_info structures * for passthru read and write queues */ static void pass_wput(queue_t *, mblk_t *); static queue_t *link_addpassthru(stdata_t *); static void link_rempassthru(queue_t *); struct module_info passthru_info = { 0, "passthru", 0, INFPSZ, STRHIGH, STRLOW }; struct qinit passthru_rinit = { (int (*)())putnext, NULL, NULL, NULL, NULL, &passthru_info, NULL }; struct qinit passthru_winit = { (int (*)()) pass_wput, NULL, NULL, NULL, NULL, &passthru_info, NULL }; /* * Special form of assertion: verify that X implies Y i.e. when X is true Y * should also be true. */ #define IMPLY(X, Y) ASSERT(!(X) || (Y)) /* * Logical equivalence. Verify that both X and Y are either TRUE or FALSE. */ #define EQUIV(X, Y) { IMPLY(X, Y); IMPLY(Y, X); } /* * Verify correctness of list head/tail pointers. */ #define LISTCHECK(head, tail, link) { \ EQUIV(head, tail); \ IMPLY(tail != NULL, tail->link == NULL); \ } /* * Enqueue a list element `el' in the end of a list denoted by `head' and `tail' * using a `link' field. */ #define ENQUEUE(el, head, tail, link) { \ ASSERT(el->link == NULL); \ LISTCHECK(head, tail, link); \ if (head == NULL) \ head = el; \ else \ tail->link = el; \ tail = el; \ } /* * Dequeue the first element of the list denoted by `head' and `tail' pointers * using a `link' field and put result into `el'. */ #define DQ(el, head, tail, link) { \ LISTCHECK(head, tail, link); \ el = head; \ if (head != NULL) { \ head = head->link; \ if (head == NULL) \ tail = NULL; \ el->link = NULL; \ } \ } /* * Remove `el' from the list using `chase' and `curr' pointers and return result * in `succeed'. */ #define RMQ(el, head, tail, link, chase, curr, succeed) { \ LISTCHECK(head, tail, link); \ chase = NULL; \ succeed = 0; \ for (curr = head; (curr != el) && (curr != NULL); curr = curr->link) \ chase = curr; \ if (curr != NULL) { \ succeed = 1; \ ASSERT(curr == el); \ if (chase != NULL) \ chase->link = curr->link; \ else \ head = curr->link; \ curr->link = NULL; \ if (curr == tail) \ tail = chase; \ } \ LISTCHECK(head, tail, link); \ } /* Handling of delayed messages on the inner syncq. */ /* * DEBUG versions should use function versions (to simplify tracing) and * non-DEBUG kernels should use macro versions. */ /* * Put a queue on the syncq list of queues. * Assumes SQLOCK held. */ #define SQPUT_Q(sq, qp) \ { \ ASSERT(MUTEX_HELD(SQLOCK(sq))); \ if (!(qp->q_sqflags & Q_SQQUEUED)) { \ /* The queue should not be linked anywhere */ \ ASSERT((qp->q_sqprev == NULL) && (qp->q_sqnext == NULL)); \ /* Head and tail may only be NULL simultaneously */ \ EQUIV(sq->sq_head, sq->sq_tail); \ /* Queue may be only enqueyed on its syncq */ \ ASSERT(sq == qp->q_syncq); \ /* Check the correctness of SQ_MESSAGES flag */ \ EQUIV(sq->sq_head, (sq->sq_flags & SQ_MESSAGES)); \ /* Sanity check first/last elements of the list */ \ IMPLY(sq->sq_head != NULL, sq->sq_head->q_sqprev == NULL);\ IMPLY(sq->sq_tail != NULL, sq->sq_tail->q_sqnext == NULL);\ /* \ * Sanity check of priority field: empty queue should \ * have zero priority \ * and nqueues equal to zero. \ */ \ IMPLY(sq->sq_head == NULL, sq->sq_pri == 0); \ /* Sanity check of sq_nqueues field */ \ EQUIV(sq->sq_head, sq->sq_nqueues); \ if (sq->sq_head == NULL) { \ sq->sq_head = sq->sq_tail = qp; \ sq->sq_flags |= SQ_MESSAGES; \ } else if (qp->q_spri == 0) { \ qp->q_sqprev = sq->sq_tail; \ sq->sq_tail->q_sqnext = qp; \ sq->sq_tail = qp; \ } else { \ /* \ * Put this queue in priority order: higher \ * priority gets closer to the head. \ */ \ queue_t **qpp = &sq->sq_tail; \ queue_t *qnext = NULL; \ \ while (*qpp != NULL && qp->q_spri > (*qpp)->q_spri) { \ qnext = *qpp; \ qpp = &(*qpp)->q_sqprev; \ } \ qp->q_sqnext = qnext; \ qp->q_sqprev = *qpp; \ if (*qpp != NULL) { \ (*qpp)->q_sqnext = qp; \ } else { \ sq->sq_head = qp; \ sq->sq_pri = sq->sq_head->q_spri; \ } \ *qpp = qp; \ } \ qp->q_sqflags |= Q_SQQUEUED; \ qp->q_sqtstamp = lbolt; \ sq->sq_nqueues++; \ } \ } /* * Remove a queue from the syncq list * Assumes SQLOCK held. */ #define SQRM_Q(sq, qp) \ { \ ASSERT(MUTEX_HELD(SQLOCK(sq))); \ ASSERT(qp->q_sqflags & Q_SQQUEUED); \ ASSERT(sq->sq_head != NULL && sq->sq_tail != NULL); \ ASSERT((sq->sq_flags & SQ_MESSAGES) != 0); \ /* Check that the queue is actually in the list */ \ ASSERT(qp->q_sqnext != NULL || sq->sq_tail == qp); \ ASSERT(qp->q_sqprev != NULL || sq->sq_head == qp); \ ASSERT(sq->sq_nqueues != 0); \ if (qp->q_sqprev == NULL) { \ /* First queue on list, make head q_sqnext */ \ sq->sq_head = qp->q_sqnext; \ } else { \ /* Make prev->next == next */ \ qp->q_sqprev->q_sqnext = qp->q_sqnext; \ } \ if (qp->q_sqnext == NULL) { \ /* Last queue on list, make tail sqprev */ \ sq->sq_tail = qp->q_sqprev; \ } else { \ /* Make next->prev == prev */ \ qp->q_sqnext->q_sqprev = qp->q_sqprev; \ } \ /* clear out references on this queue */ \ qp->q_sqprev = qp->q_sqnext = NULL; \ qp->q_sqflags &= ~Q_SQQUEUED; \ /* If there is nothing queued, clear SQ_MESSAGES */ \ if (sq->sq_head != NULL) { \ sq->sq_pri = sq->sq_head->q_spri; \ } else { \ sq->sq_flags &= ~SQ_MESSAGES; \ sq->sq_pri = 0; \ } \ sq->sq_nqueues--; \ ASSERT(sq->sq_head != NULL || sq->sq_evhead != NULL || \ (sq->sq_flags & SQ_QUEUED) == 0); \ } /* Hide the definition from the header file. */ #ifdef SQPUT_MP #undef SQPUT_MP #endif /* * Put a message on the queue syncq. * Assumes QLOCK held. */ #define SQPUT_MP(qp, mp) \ { \ ASSERT(MUTEX_HELD(QLOCK(qp))); \ ASSERT(qp->q_sqhead == NULL || \ (qp->q_sqtail != NULL && \ qp->q_sqtail->b_next == NULL)); \ qp->q_syncqmsgs++; \ ASSERT(qp->q_syncqmsgs != 0); /* Wraparound */ \ if (qp->q_sqhead == NULL) { \ qp->q_sqhead = qp->q_sqtail = mp; \ } else { \ qp->q_sqtail->b_next = mp; \ qp->q_sqtail = mp; \ } \ ASSERT(qp->q_syncqmsgs > 0); \ } #define SQ_PUTCOUNT_SETFAST_LOCKED(sq) { \ ASSERT(MUTEX_HELD(SQLOCK(sq))); \ if ((sq)->sq_ciputctrl != NULL) { \ int i; \ int nlocks = (sq)->sq_nciputctrl; \ ciputctrl_t *cip = (sq)->sq_ciputctrl; \ ASSERT((sq)->sq_type & SQ_CIPUT); \ for (i = 0; i <= nlocks; i++) { \ ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ cip[i].ciputctrl_count |= SQ_FASTPUT; \ } \ } \ } #define SQ_PUTCOUNT_CLRFAST_LOCKED(sq) { \ ASSERT(MUTEX_HELD(SQLOCK(sq))); \ if ((sq)->sq_ciputctrl != NULL) { \ int i; \ int nlocks = (sq)->sq_nciputctrl; \ ciputctrl_t *cip = (sq)->sq_ciputctrl; \ ASSERT((sq)->sq_type & SQ_CIPUT); \ for (i = 0; i <= nlocks; i++) { \ ASSERT(MUTEX_HELD(&cip[i].ciputctrl_lock)); \ cip[i].ciputctrl_count &= ~SQ_FASTPUT; \ } \ } \ } /* * Run service procedures for all queues in the stream head. */ #define STR_SERVICE(stp, q) { \ ASSERT(MUTEX_HELD(&stp->sd_qlock)); \ while (stp->sd_qhead != NULL) { \ DQ(q, stp->sd_qhead, stp->sd_qtail, q_link); \ ASSERT(stp->sd_nqueues > 0); \ stp->sd_nqueues--; \ ASSERT(!(q->q_flag & QINSERVICE)); \ mutex_exit(&stp->sd_qlock); \ queue_service(q); \ mutex_enter(&stp->sd_qlock); \ } \ ASSERT(stp->sd_nqueues == 0); \ ASSERT((stp->sd_qhead == NULL) && (stp->sd_qtail == NULL)); \ } /* * constructor/destructor routines for the stream head cache */ /* ARGSUSED */ static int stream_head_constructor(void *buf, void *cdrarg, int kmflags) { stdata_t *stp = buf; mutex_init(&stp->sd_lock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&stp->sd_reflock, NULL, MUTEX_DEFAULT, NULL); mutex_init(&stp->sd_qlock, NULL, MUTEX_DEFAULT, NULL); cv_init(&stp->sd_monitor, NULL, CV_DEFAULT, NULL); cv_init(&stp->sd_iocmonitor, NULL, CV_DEFAULT, NULL); cv_init(&stp->sd_refmonitor, NULL, CV_DEFAULT, NULL); cv_init(&stp->sd_qcv, NULL, CV_DEFAULT, NULL); cv_init(&stp->sd_zcopy_wait, NULL, CV_DEFAULT, NULL); stp->sd_wrq = NULL; return (0); } /* ARGSUSED */ static void stream_head_destructor(void *buf, void *cdrarg) { stdata_t *stp = buf; mutex_destroy(&stp->sd_lock); mutex_destroy(&stp->sd_reflock); mutex_destroy(&stp->sd_qlock); cv_destroy(&stp->sd_monitor); cv_destroy(&stp->sd_iocmonitor); cv_destroy(&stp->sd_refmonitor); cv_destroy(&stp->sd_qcv); cv_destroy(&stp->sd_zcopy_wait); } /* * constructor/destructor routines for the queue cache */ /* ARGSUSED */ static int queue_constructor(void *buf, void *cdrarg, int kmflags) { queinfo_t *qip = buf; queue_t *qp = &qip->qu_rqueue; queue_t *wqp = &qip->qu_wqueue; syncq_t *sq = &qip->qu_syncq; qp->q_first = NULL; qp->q_link = NULL; qp->q_count = 0; qp->q_mblkcnt = 0; qp->q_sqhead = NULL; qp->q_sqtail = NULL; qp->q_sqnext = NULL; qp->q_sqprev = NULL; qp->q_sqflags = 0; qp->q_rwcnt = 0; qp->q_spri = 0; mutex_init(QLOCK(qp), NULL, MUTEX_DEFAULT, NULL); cv_init(&qp->q_wait, NULL, CV_DEFAULT, NULL); wqp->q_first = NULL; wqp->q_link = NULL; wqp->q_count = 0; wqp->q_mblkcnt = 0; wqp->q_sqhead = NULL; wqp->q_sqtail = NULL; wqp->q_sqnext = NULL; wqp->q_sqprev = NULL; wqp->q_sqflags = 0; wqp->q_rwcnt = 0; wqp->q_spri = 0; mutex_init(QLOCK(wqp), NULL, MUTEX_DEFAULT, NULL); cv_init(&wqp->q_wait, NULL, CV_DEFAULT, NULL); sq->sq_head = NULL; sq->sq_tail = NULL; sq->sq_evhead = NULL; sq->sq_evtail = NULL; sq->sq_callbpend = NULL; sq->sq_outer = NULL; sq->sq_onext = NULL; sq->sq_oprev = NULL; sq->sq_next = NULL; sq->sq_svcflags = 0; sq->sq_servcount = 0; sq->sq_needexcl = 0; sq->sq_nqueues = 0; sq->sq_pri = 0; mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); return (0); } /* ARGSUSED */ static void queue_destructor(void *buf, void *cdrarg) { queinfo_t *qip = buf; queue_t *qp = &qip->qu_rqueue; queue_t *wqp = &qip->qu_wqueue; syncq_t *sq = &qip->qu_syncq; ASSERT(qp->q_sqhead == NULL); ASSERT(wqp->q_sqhead == NULL); ASSERT(qp->q_sqnext == NULL); ASSERT(wqp->q_sqnext == NULL); ASSERT(qp->q_rwcnt == 0); ASSERT(wqp->q_rwcnt == 0); mutex_destroy(&qp->q_lock); cv_destroy(&qp->q_wait); mutex_destroy(&wqp->q_lock); cv_destroy(&wqp->q_wait); mutex_destroy(&sq->sq_lock); cv_destroy(&sq->sq_wait); cv_destroy(&sq->sq_exitwait); } /* * constructor/destructor routines for the syncq cache */ /* ARGSUSED */ static int syncq_constructor(void *buf, void *cdrarg, int kmflags) { syncq_t *sq = buf; bzero(buf, sizeof (syncq_t)); mutex_init(&sq->sq_lock, NULL, MUTEX_DEFAULT, NULL); cv_init(&sq->sq_wait, NULL, CV_DEFAULT, NULL); cv_init(&sq->sq_exitwait, NULL, CV_DEFAULT, NULL); return (0); } /* ARGSUSED */ static void syncq_destructor(void *buf, void *cdrarg) { syncq_t *sq = buf; ASSERT(sq->sq_head == NULL); ASSERT(sq->sq_tail == NULL); ASSERT(sq->sq_evhead == NULL); ASSERT(sq->sq_evtail == NULL); ASSERT(sq->sq_callbpend == NULL); ASSERT(sq->sq_callbflags == 0); ASSERT(sq->sq_outer == NULL); ASSERT(sq->sq_onext == NULL); ASSERT(sq->sq_oprev == NULL); ASSERT(sq->sq_next == NULL); ASSERT(sq->sq_needexcl == 0); ASSERT(sq->sq_svcflags == 0); ASSERT(sq->sq_servcount == 0); ASSERT(sq->sq_nqueues == 0); ASSERT(sq->sq_pri == 0); ASSERT(sq->sq_count == 0); ASSERT(sq->sq_rmqcount == 0); ASSERT(sq->sq_cancelid == 0); ASSERT(sq->sq_ciputctrl == NULL); ASSERT(sq->sq_nciputctrl == 0); ASSERT(sq->sq_type == 0); ASSERT(sq->sq_flags == 0); mutex_destroy(&sq->sq_lock); cv_destroy(&sq->sq_wait); cv_destroy(&sq->sq_exitwait); } /* ARGSUSED */ static int ciputctrl_constructor(void *buf, void *cdrarg, int kmflags) { ciputctrl_t *cip = buf; int i; for (i = 0; i < n_ciputctrl; i++) { cip[i].ciputctrl_count = SQ_FASTPUT; mutex_init(&cip[i].ciputctrl_lock, NULL, MUTEX_DEFAULT, NULL); } return (0); } /* ARGSUSED */ static void ciputctrl_destructor(void *buf, void *cdrarg) { ciputctrl_t *cip = buf; int i; for (i = 0; i < n_ciputctrl; i++) { ASSERT(cip[i].ciputctrl_count & SQ_FASTPUT); mutex_destroy(&cip[i].ciputctrl_lock); } } /* * Init routine run from main at boot time. */ void strinit(void) { int i; int ncpus = ((boot_max_ncpus == -1) ? max_ncpus : boot_max_ncpus); /* * Set up mux_node structures. */ mux_nodes = kmem_zalloc((sizeof (struct mux_node) * devcnt), KM_SLEEP); for (i = 0; i < devcnt; i++) mux_nodes[i].mn_imaj = i; stream_head_cache = kmem_cache_create("stream_head_cache", sizeof (stdata_t), 0, stream_head_constructor, stream_head_destructor, NULL, NULL, NULL, 0); queue_cache = kmem_cache_create("queue_cache", sizeof (queinfo_t), 0, queue_constructor, queue_destructor, NULL, NULL, NULL, 0); syncq_cache = kmem_cache_create("syncq_cache", sizeof (syncq_t), 0, syncq_constructor, syncq_destructor, NULL, NULL, NULL, 0); qband_cache = kmem_cache_create("qband_cache", sizeof (qband_t), 0, NULL, NULL, NULL, NULL, NULL, 0); linkinfo_cache = kmem_cache_create("linkinfo_cache", sizeof (linkinfo_t), 0, NULL, NULL, NULL, NULL, NULL, 0); n_ciputctrl = ncpus; n_ciputctrl = 1 << highbit(n_ciputctrl - 1); ASSERT(n_ciputctrl >= 1); n_ciputctrl = MIN(n_ciputctrl, max_n_ciputctrl); if (n_ciputctrl >= min_n_ciputctrl) { ciputctrl_cache = kmem_cache_create("ciputctrl_cache", sizeof (ciputctrl_t) * n_ciputctrl, sizeof (ciputctrl_t), ciputctrl_constructor, ciputctrl_destructor, NULL, NULL, NULL, 0); } streams_taskq = system_taskq; if (streams_taskq == NULL) panic("strinit: no memory for streams taskq!"); bc_bkgrnd_thread = thread_create(NULL, 0, streams_bufcall_service, NULL, 0, &p0, TS_RUN, streams_lopri); streams_qbkgrnd_thread = thread_create(NULL, 0, streams_qbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); streams_sqbkgrnd_thread = thread_create(NULL, 0, streams_sqbkgrnd_service, NULL, 0, &p0, TS_RUN, streams_lopri); /* * Create STREAMS kstats. */ str_kstat = kstat_create("streams", 0, "strstat", "net", KSTAT_TYPE_NAMED, sizeof (str_statistics) / sizeof (kstat_named_t), KSTAT_FLAG_VIRTUAL); if (str_kstat != NULL) { str_kstat->ks_data = &str_statistics; kstat_install(str_kstat); } /* * TPI support routine initialisation. */ tpi_init(); } void str_sendsig(vnode_t *vp, int event, uchar_t band, int error) { struct stdata *stp; ASSERT(vp->v_stream); stp = vp->v_stream; /* Have to hold sd_lock to prevent siglist from changing */ mutex_enter(&stp->sd_lock); if (stp->sd_sigflags & event) strsendsig(stp->sd_siglist, event, band, error); mutex_exit(&stp->sd_lock); } /* * Send the "sevent" set of signals to a process. * This might send more than one signal if the process is registered * for multiple events. The caller should pass in an sevent that only * includes the events for which the process has registered. */ static void dosendsig(proc_t *proc, int events, int sevent, k_siginfo_t *info, uchar_t band, int error) { ASSERT(MUTEX_HELD(&proc->p_lock)); info->si_band = 0; info->si_errno = 0; if (sevent & S_ERROR) { sevent &= ~S_ERROR; info->si_code = POLL_ERR; info->si_errno = error; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); info->si_errno = 0; } if (sevent & S_HANGUP) { sevent &= ~S_HANGUP; info->si_code = POLL_HUP; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); } if (sevent & S_HIPRI) { sevent &= ~S_HIPRI; info->si_code = POLL_PRI; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); } if (sevent & S_RDBAND) { sevent &= ~S_RDBAND; if (events & S_BANDURG) sigtoproc(proc, NULL, SIGURG); else sigtoproc(proc, NULL, SIGPOLL); } if (sevent & S_WRBAND) { sevent &= ~S_WRBAND; sigtoproc(proc, NULL, SIGPOLL); } if (sevent & S_INPUT) { sevent &= ~S_INPUT; info->si_code = POLL_IN; info->si_band = band; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); info->si_band = 0; } if (sevent & S_OUTPUT) { sevent &= ~S_OUTPUT; info->si_code = POLL_OUT; info->si_band = band; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); info->si_band = 0; } if (sevent & S_MSG) { sevent &= ~S_MSG; info->si_code = POLL_MSG; info->si_band = band; TRACE_2(TR_FAC_STREAMS_FR, TR_STRSENDSIG, "strsendsig:proc %p info %p", proc, info); sigaddq(proc, NULL, info, KM_NOSLEEP); info->si_band = 0; } if (sevent & S_RDNORM) { sevent &= ~S_RDNORM; sigtoproc(proc, NULL, SIGPOLL); } if (sevent != 0) { panic("strsendsig: unknown event(s) %x", sevent); } } /* * Send SIGPOLL/SIGURG signal to all processes and process groups * registered on the given signal list that want a signal for at * least one of the specified events. * * Must be called with exclusive access to siglist (caller holding sd_lock). * * strioctl(I_SETSIG/I_ESETSIG) will only change siglist when holding * sd_lock and the ioctl code maintains a PID_HOLD on the pid structure * while it is in the siglist. * * For performance reasons (MP scalability) the code drops pidlock * when sending signals to a single process. * When sending to a process group the code holds * pidlock to prevent the membership in the process group from changing * while walking the p_pglink list. */ void strsendsig(strsig_t *siglist, int event, uchar_t band, int error) { strsig_t *ssp; k_siginfo_t info; struct pid *pidp; proc_t *proc; info.si_signo = SIGPOLL; info.si_errno = 0; for (ssp = siglist; ssp; ssp = ssp->ss_next) { int sevent; sevent = ssp->ss_events & event; if (sevent == 0) continue; if ((pidp = ssp->ss_pidp) == NULL) { /* pid was released but still on event list */ continue; } if (ssp->ss_pid > 0) { /* * XXX This unfortunately still generates * a signal when a fd is closed but * the proc is active. */ ASSERT(ssp->ss_pid == pidp->pid_id); mutex_enter(&pidlock); proc = prfind_zone(pidp->pid_id, ALL_ZONES); if (proc == NULL) { mutex_exit(&pidlock); continue; } mutex_enter(&proc->p_lock); mutex_exit(&pidlock); dosendsig(proc, ssp->ss_events, sevent, &info, band, error); mutex_exit(&proc->p_lock); } else { /* * Send to process group. Hold pidlock across * calls to dosendsig(). */ pid_t pgrp = -ssp->ss_pid; mutex_enter(&pidlock); proc = pgfind_zone(pgrp, ALL_ZONES); while (proc != NULL) { mutex_enter(&proc->p_lock); dosendsig(proc, ssp->ss_events, sevent, &info, band, error); mutex_exit(&proc->p_lock); proc = proc->p_pglink; } mutex_exit(&pidlock); } } } /* * Attach a stream device or module. * qp is a read queue; the new queue goes in so its next * read ptr is the argument, and the write queue corresponding * to the argument points to this queue. Return 0 on success, * or a non-zero errno on failure. */ int qattach(queue_t *qp, dev_t *devp, int oflag, cred_t *crp, fmodsw_impl_t *fp, boolean_t is_insert) { major_t major; cdevsw_impl_t *dp; struct streamtab *str; queue_t *rq; queue_t *wrq; uint32_t qflag; uint32_t sqtype; perdm_t *dmp; int error; int sflag; rq = allocq(); wrq = _WR(rq); STREAM(rq) = STREAM(wrq) = STREAM(qp); if (fp != NULL) { str = fp->f_str; qflag = fp->f_qflag; sqtype = fp->f_sqtype; dmp = fp->f_dmp; IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); sflag = MODOPEN; /* * stash away a pointer to the module structure so we can * unref it in qdetach. */ rq->q_fp = fp; } else { ASSERT(!is_insert); major = getmajor(*devp); dp = &devimpl[major]; str = dp->d_str; ASSERT(str == STREAMSTAB(major)); qflag = dp->d_qflag; ASSERT(qflag & QISDRV); sqtype = dp->d_sqtype; /* create perdm_t if needed */ if (NEED_DM(dp->d_dmp, qflag)) dp->d_dmp = hold_dm(str, qflag, sqtype); dmp = dp->d_dmp; sflag = 0; } TRACE_2(TR_FAC_STREAMS_FR, TR_QATTACH_FLAGS, "qattach:qflag == %X(%X)", qflag, *devp); /* setq might sleep in allocator - avoid holding locks. */ setq(rq, str->st_rdinit, str->st_wrinit, dmp, qflag, sqtype, B_FALSE); /* * Before calling the module's open routine, set up the q_next * pointer for inserting a module in the middle of a stream. * * Note that we can always set _QINSERTING and set up q_next * pointer for both inserting and pushing a module. Then there * is no need for the is_insert parameter. In insertq(), called * by qprocson(), assume that q_next of the new module always points * to the correct queue and use it for insertion. Everything should * work out fine. But in the first release of _I_INSERT, we * distinguish between inserting and pushing to make sure that * pushing a module follows the same code path as before. */ if (is_insert) { rq->q_flag |= _QINSERTING; rq->q_next = qp; } /* * If there is an outer perimeter get exclusive access during * the open procedure. Bump up the reference count on the queue. */ entersq(rq->q_syncq, SQ_OPENCLOSE); error = (*rq->q_qinfo->qi_qopen)(rq, devp, oflag, sflag, crp); if (error != 0) goto failed; leavesq(rq->q_syncq, SQ_OPENCLOSE); ASSERT(qprocsareon(rq)); return (0); failed: rq->q_flag &= ~_QINSERTING; if (backq(wrq) != NULL && backq(wrq)->q_next == wrq) qprocsoff(rq); leavesq(rq->q_syncq, SQ_OPENCLOSE); rq->q_next = wrq->q_next = NULL; qdetach(rq, 0, 0, crp, B_FALSE); return (error); } /* * Handle second open of stream. For modules, set the * last argument to MODOPEN and do not pass any open flags. * Ignore dummydev since this is not the first open. */ int qreopen(queue_t *qp, dev_t *devp, int flag, cred_t *crp) { int error; dev_t dummydev; queue_t *wqp = _WR(qp); ASSERT(qp->q_flag & QREADR); entersq(qp->q_syncq, SQ_OPENCLOSE); dummydev = *devp; if (error = ((*qp->q_qinfo->qi_qopen)(qp, &dummydev, (wqp->q_next ? 0 : flag), (wqp->q_next ? MODOPEN : 0), crp))) { leavesq(qp->q_syncq, SQ_OPENCLOSE); mutex_enter(&STREAM(qp)->sd_lock); qp->q_stream->sd_flag |= STREOPENFAIL; mutex_exit(&STREAM(qp)->sd_lock); return (error); } leavesq(qp->q_syncq, SQ_OPENCLOSE); /* * successful open should have done qprocson() */ ASSERT(qprocsareon(_RD(qp))); return (0); } /* * Detach a stream module or device. * If clmode == 1 then the module or driver was opened and its * close routine must be called. If clmode == 0, the module * or driver was never opened or the open failed, and so its close * should not be called. */ void qdetach(queue_t *qp, int clmode, int flag, cred_t *crp, boolean_t is_remove) { queue_t *wqp = _WR(qp); ASSERT(STREAM(qp)->sd_flag & (STRCLOSE|STWOPEN|STRPLUMB)); if (STREAM_NEEDSERVICE(STREAM(qp))) stream_runservice(STREAM(qp)); if (clmode) { /* * Make sure that all the messages on the write side syncq are * processed and nothing is left. Since we are closing, no new * messages may appear there. */ wait_q_syncq(wqp); entersq(qp->q_syncq, SQ_OPENCLOSE); if (is_remove) { mutex_enter(QLOCK(qp)); qp->q_flag |= _QREMOVING; mutex_exit(QLOCK(qp)); } (*qp->q_qinfo->qi_qclose)(qp, flag, crp); /* * Check that qprocsoff() was actually called. */ ASSERT((qp->q_flag & QWCLOSE) && (wqp->q_flag & QWCLOSE)); leavesq(qp->q_syncq, SQ_OPENCLOSE); } else { disable_svc(qp); } /* * Allow any threads blocked in entersq to proceed and discover * the QWCLOSE is set. * Note: This assumes that all users of entersq check QWCLOSE. * Currently runservice is the only entersq that can happen * after removeq has finished. * Removeq will have discarded all messages destined to the closing * pair of queues from the syncq. * NOTE: Calling a function inside an assert is unconventional. * However, it does not cause any problem since flush_syncq() does * not change any state except when it returns non-zero i.e. * when the assert will trigger. */ ASSERT(flush_syncq(qp->q_syncq, qp) == 0); ASSERT(flush_syncq(wqp->q_syncq, wqp) == 0); ASSERT((qp->q_flag & QPERMOD) || ((qp->q_syncq->sq_head == NULL) && (wqp->q_syncq->sq_head == NULL))); /* * Flush the queues before q_next is set to NULL. This is needed * in order to backenable any downstream queue before we go away. * Note: we are already removed from the stream so that the * backenabling will not cause any messages to be delivered to our * put procedures. */ flushq(qp, FLUSHALL); flushq(wqp, FLUSHALL); /* * wait for any pending service processing to complete */ wait_svc(qp); /* Tidy up - removeq only does a half-remove from stream */ qp->q_next = wqp->q_next = NULL; ASSERT(!(qp->q_flag & QENAB)); ASSERT(!(wqp->q_flag & QENAB)); /* release any fmodsw_impl_t structure held on behalf of the queue */ ASSERT(qp->q_fp != NULL || qp->q_flag & QISDRV); if (qp->q_fp != NULL) fmodsw_rele(qp->q_fp); /* freeq removes us from the outer perimeter if any */ freeq(qp); } /* Prevent service procedures from being called */ void disable_svc(queue_t *qp) { queue_t *wqp = _WR(qp); ASSERT(qp->q_flag & QREADR); mutex_enter(QLOCK(qp)); qp->q_flag |= QWCLOSE; mutex_exit(QLOCK(qp)); mutex_enter(QLOCK(wqp)); wqp->q_flag |= QWCLOSE; mutex_exit(QLOCK(wqp)); } /* allow service procedures to be called again */ void enable_svc(queue_t *qp) { queue_t *wqp = _WR(qp); ASSERT(qp->q_flag & QREADR); mutex_enter(QLOCK(qp)); qp->q_flag &= ~QWCLOSE; mutex_exit(QLOCK(qp)); mutex_enter(QLOCK(wqp)); wqp->q_flag &= ~QWCLOSE; mutex_exit(QLOCK(wqp)); } /* * Remove queue from qhead/qtail if it is enabled. * Only reset QENAB if the queue was removed from the runlist. * A queue goes through 3 stages: * It is on the service list and QENAB is set. * It is removed from the service list but QENAB is still set. * QENAB gets changed to QINSERVICE. * QINSERVICE is reset (when the service procedure is done) * Thus we can not reset QENAB unless we actually removed it from the service * queue. */ void remove_runlist(queue_t *qp) { if (qp->q_flag & QENAB && qhead != NULL) { queue_t *q_chase; queue_t *q_curr; int removed; mutex_enter(&service_queue); RMQ(qp, qhead, qtail, q_link, q_chase, q_curr, removed); mutex_exit(&service_queue); if (removed) { STRSTAT(qremoved); qp->q_flag &= ~QENAB; } } } /* * wait for any pending service processing to complete. * The removal of queues from the runlist is not atomic with the * clearing of the QENABLED flag and setting the INSERVICE flag. * consequently it is possible for remove_runlist in strclose * to not find the queue on the runlist but for it to be QENABLED * and not yet INSERVICE -> hence wait_svc needs to check QENABLED * as well as INSERVICE. */ void wait_svc(queue_t *qp) { queue_t *wqp = _WR(qp); ASSERT(qp->q_flag & QREADR); /* * Try to remove queues from qhead/qtail list. */ if (qhead != NULL) { remove_runlist(qp); remove_runlist(wqp); } /* * Wait till the syncqs associated with the queue * will dissapear from background processing list. * This only needs to be done for non-PERMOD perimeters since * for PERMOD perimeters the syncq may be shared and will only be freed * when the last module/driver is unloaded. * If for PERMOD perimeters queue was on the syncq list, removeq() * should call propagate_syncq() or drain_syncq() for it. Both of these * function remove the queue from its syncq list, so sqthread will not * try to access the queue. */ if (!(qp->q_flag & QPERMOD)) { syncq_t *rsq = qp->q_syncq; syncq_t *wsq = wqp->q_syncq; /* * Disable rsq and wsq and wait for any background processing of * syncq to complete. */ wait_sq_svc(rsq); if (wsq != rsq) wait_sq_svc(wsq); } mutex_enter(QLOCK(qp)); while (qp->q_flag & (QINSERVICE|QENAB)) cv_wait(&qp->q_wait, QLOCK(qp)); mutex_exit(QLOCK(qp)); mutex_enter(QLOCK(wqp)); while (wqp->q_flag & (QINSERVICE|QENAB)) cv_wait(&wqp->q_wait, QLOCK(wqp)); mutex_exit(QLOCK(wqp)); } /* * Put ioctl data from userland buffer `arg' into the mblk chain `bp'. * `flag' must always contain either K_TO_K or U_TO_K; STR_NOSIG may * also be set, and is passed through to allocb_cred_wait(). * * Returns errno on failure, zero on success. */ int putiocd(mblk_t *bp, char *arg, int flag, cred_t *cr) { mblk_t *tmp; ssize_t count; size_t n; int error = 0; ASSERT((flag & (U_TO_K | K_TO_K)) == U_TO_K || (flag & (U_TO_K | K_TO_K)) == K_TO_K); if (bp->b_datap->db_type == M_IOCTL) { count = ((struct iocblk *)bp->b_rptr)->ioc_count; } else { ASSERT(bp->b_datap->db_type == M_COPYIN); count = ((struct copyreq *)bp->b_rptr)->cq_size; } /* * strdoioctl validates ioc_count, so if this assert fails it * cannot be due to user error. */ ASSERT(count >= 0); while (count > 0) { n = MIN(MAXIOCBSZ, count); if ((tmp = allocb_cred_wait(n, (flag & STR_NOSIG), &error, cr)) == NULL) { return (error); } error = strcopyin(arg, tmp->b_wptr, n, flag & (U_TO_K|K_TO_K)); if (error != 0) { freeb(tmp); return (error); } arg += n; DB_CPID(tmp) = curproc->p_pid; tmp->b_wptr += n; count -= n; bp = (bp->b_cont = tmp); } return (0); } /* * Copy ioctl data to user-land. Return non-zero errno on failure, * 0 for success. */ int getiocd(mblk_t *bp, char *arg, int copymode) { ssize_t count; size_t n; int error; if (bp->b_datap->db_type == M_IOCACK) count = ((struct iocblk *)bp->b_rptr)->ioc_count; else { ASSERT(bp->b_datap->db_type == M_COPYOUT); count = ((struct copyreq *)bp->b_rptr)->cq_size; } ASSERT(count >= 0); for (bp = bp->b_cont; bp && count; count -= n, bp = bp->b_cont, arg += n) { n = MIN(count, bp->b_wptr - bp->b_rptr); error = strcopyout(bp->b_rptr, arg, n, copymode); if (error) return (error); } ASSERT(count == 0); return (0); } /* * Allocate a linkinfo entry given the write queue of the * bottom module of the top stream and the write queue of the * stream head of the bottom stream. */ linkinfo_t * alloclink(queue_t *qup, queue_t *qdown, file_t *fpdown) { linkinfo_t *linkp; linkp = kmem_cache_alloc(linkinfo_cache, KM_SLEEP); linkp->li_lblk.l_qtop = qup; linkp->li_lblk.l_qbot = qdown; linkp->li_fpdown = fpdown; mutex_enter(&strresources); linkp->li_next = linkinfo_list; linkp->li_prev = NULL; if (linkp->li_next) linkp->li_next->li_prev = linkp; linkinfo_list = linkp; linkp->li_lblk.l_index = ++lnk_id; ASSERT(lnk_id != 0); /* this should never wrap in practice */ mutex_exit(&strresources); return (linkp); } /* * Free a linkinfo entry. */ void lbfree(linkinfo_t *linkp) { mutex_enter(&strresources); if (linkp->li_next) linkp->li_next->li_prev = linkp->li_prev; if (linkp->li_prev) linkp->li_prev->li_next = linkp->li_next; else linkinfo_list = linkp->li_next; mutex_exit(&strresources); kmem_cache_free(linkinfo_cache, linkp); } /* * Check for a potential linking cycle. * Return 1 if a link will result in a cycle, * and 0 otherwise. */ int linkcycle(stdata_t *upstp, stdata_t *lostp) { struct mux_node *np; struct mux_edge *ep; int i; major_t lomaj; major_t upmaj; /* * if the lower stream is a pipe/FIFO, return, since link * cycles can not happen on pipes/FIFOs */ if (lostp->sd_vnode->v_type == VFIFO) return (0); for (i = 0; i < devcnt; i++) { np = &mux_nodes[i]; MUX_CLEAR(np); } lomaj = getmajor(lostp->sd_vnode->v_rdev); upmaj = getmajor(upstp->sd_vnode->v_rdev); np = &mux_nodes[lomaj]; for (;;) { if (!MUX_DIDVISIT(np)) { if (np->mn_imaj == upmaj) return (1); if (np->mn_outp == NULL) { MUX_VISIT(np); if (np->mn_originp == NULL) return (0); np = np->mn_originp; continue; } MUX_VISIT(np); np->mn_startp = np->mn_outp; } else { if (np->mn_startp == NULL) { if (np->mn_originp == NULL) return (0); else { np = np->mn_originp; continue; } } /* * If ep->me_nodep is a FIFO (me_nodep == NULL), * ignore the edge and move on. ep->me_nodep gets * set to NULL in mux_addedge() if it is a FIFO. * */ ep = np->mn_startp; np->mn_startp = ep->me_nextp; if (ep->me_nodep == NULL) continue; ep->me_nodep->mn_originp = np; np = ep->me_nodep; } } } /* * Find linkinfo entry corresponding to the parameters. */ linkinfo_t * findlinks(stdata_t *stp, int index, int type) { linkinfo_t *linkp; struct mux_edge *mep; struct mux_node *mnp; queue_t *qup; mutex_enter(&strresources); if ((type & LINKTYPEMASK) == LINKNORMAL) { qup = getendq(stp->sd_wrq); for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { if ((qup == linkp->li_lblk.l_qtop) && (!index || (index == linkp->li_lblk.l_index))) { mutex_exit(&strresources); return (linkp); } } } else { ASSERT((type & LINKTYPEMASK) == LINKPERSIST); mnp = &mux_nodes[getmajor(stp->sd_vnode->v_rdev)]; mep = mnp->mn_outp; while (mep) { if ((index == 0) || (index == mep->me_muxid)) break; mep = mep->me_nextp; } if (!mep) { mutex_exit(&strresources); return (NULL); } for (linkp = linkinfo_list; linkp; linkp = linkp->li_next) { if ((!linkp->li_lblk.l_qtop) && (mep->me_muxid == linkp->li_lblk.l_index)) { mutex_exit(&strresources); return (linkp); } } } mutex_exit(&strresources); return (NULL); } /* * Given a queue ptr, follow the chain of q_next pointers until you reach the * last queue on the chain and return it. */ queue_t * getendq(queue_t *q) { ASSERT(q != NULL); while (_SAMESTR(q)) q = q->q_next; return (q); } /* * wait for the syncq count to drop to zero. * sq could be either outer or inner. */ static void wait_syncq(syncq_t *sq) { uint16_t count; mutex_enter(SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); while (count != 0) { sq->sq_flags |= SQ_WANTWAKEUP; SQ_PUTLOCKS_EXIT(sq); cv_wait(&sq->sq_wait, SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); } /* * Wait while there are any messages for the queue in its syncq. */ static void wait_q_syncq(queue_t *q) { if ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { syncq_t *sq = q->q_syncq; mutex_enter(SQLOCK(sq)); while ((q->q_sqflags & Q_SQQUEUED) || (q->q_syncqmsgs > 0)) { sq->sq_flags |= SQ_WANTWAKEUP; cv_wait(&sq->sq_wait, SQLOCK(sq)); } mutex_exit(SQLOCK(sq)); } } int mlink_file(vnode_t *vp, int cmd, struct file *fpdown, cred_t *crp, int *rvalp, int lhlink) { struct stdata *stp; struct strioctl strioc; struct linkinfo *linkp; struct stdata *stpdown; struct streamtab *str; queue_t *passq; syncq_t *passyncq; queue_t *rq; cdevsw_impl_t *dp; uint32_t qflag; uint32_t sqtype; perdm_t *dmp; int error = 0; stp = vp->v_stream; TRACE_1(TR_FAC_STREAMS_FR, TR_I_LINK, "I_LINK/I_PLINK:stp %p", stp); /* * Test for invalid upper stream */ if (stp->sd_flag & STRHUP) { return (ENXIO); } if (vp->v_type == VFIFO) { return (EINVAL); } if (stp->sd_strtab == NULL) { return (EINVAL); } if (!stp->sd_strtab->st_muxwinit) { return (EINVAL); } if (fpdown == NULL) { return (EBADF); } if (getmajor(stp->sd_vnode->v_rdev) >= devcnt) { return (EINVAL); } mutex_enter(&muxifier); if (stp->sd_flag & STPLEX) { mutex_exit(&muxifier); return (ENXIO); } /* * Test for invalid lower stream. * The check for the v_type != VFIFO and having a major * number not >= devcnt is done to avoid problems with * adding mux_node entry past the end of mux_nodes[]. * For FIFO's we don't add an entry so this isn't a * problem. */ if (((stpdown = fpdown->f_vnode->v_stream) == NULL) || (stpdown == stp) || (stpdown->sd_flag & (STPLEX|STRHUP|STRDERR|STWRERR|IOCWAIT|STRPLUMB)) || ((stpdown->sd_vnode->v_type != VFIFO) && (getmajor(stpdown->sd_vnode->v_rdev) >= devcnt)) || linkcycle(stp, stpdown)) { mutex_exit(&muxifier); return (EINVAL); } TRACE_1(TR_FAC_STREAMS_FR, TR_STPDOWN, "stpdown:%p", stpdown); rq = getendq(stp->sd_wrq); if (cmd == I_PLINK) rq = NULL; linkp = alloclink(rq, stpdown->sd_wrq, fpdown); strioc.ic_cmd = cmd; strioc.ic_timout = INFTIM; strioc.ic_len = sizeof (struct linkblk); strioc.ic_dp = (char *)&linkp->li_lblk; /* * STRPLUMB protects plumbing changes and should be set before * link_addpassthru()/link_rempassthru() are called, so it is set here * and cleared in the end of mlink when passthru queue is removed. * Setting of STRPLUMB prevents reopens of the stream while passthru * queue is in-place (it is not a proper module and doesn't have open * entry point). * * STPLEX prevents any threads from entering the stream from above. It * can't be set before the call to link_addpassthru() because putnext * from below may cause stream head I/O routines to be called and these * routines assert that STPLEX is not set. After link_addpassthru() * nothing may come from below since the pass queue syncq is blocked. * Note also that STPLEX should be cleared before the call to * link_remmpassthru() since when messages start flowing to the stream * head (e.g. because of message propagation from the pass queue) stream * head I/O routines may be called with STPLEX flag set. * * When STPLEX is set, nothing may come into the stream from above and * it is safe to do a setq which will change stream head. So, the * correct sequence of actions is: * * 1) Set STRPLUMB * 2) Call link_addpassthru() * 3) Set STPLEX * 4) Call setq and update the stream state * 5) Clear STPLEX * 6) Call link_rempassthru() * 7) Clear STRPLUMB * * The same sequence applies to munlink() code. */ mutex_enter(&stpdown->sd_lock); stpdown->sd_flag |= STRPLUMB; mutex_exit(&stpdown->sd_lock); /* * Add passthru queue below lower mux. This will block * syncqs of lower muxs read queue during I_LINK/I_UNLINK. */ passq = link_addpassthru(stpdown); mutex_enter(&stpdown->sd_lock); stpdown->sd_flag |= STPLEX; mutex_exit(&stpdown->sd_lock); rq = _RD(stpdown->sd_wrq); /* * There may be messages in the streamhead's syncq due to messages * that arrived before link_addpassthru() was done. To avoid * background processing of the syncq happening simultaneous with * setq processing, we disable the streamhead syncq and wait until * existing background thread finishes working on it. */ wait_sq_svc(rq->q_syncq); passyncq = passq->q_syncq; if (!(passyncq->sq_flags & SQ_BLOCKED)) blocksq(passyncq, SQ_BLOCKED, 0); ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); rq->q_ptr = _WR(rq)->q_ptr = NULL; /* setq might sleep in allocator - avoid holding locks. */ /* Note: we are holding muxifier here. */ str = stp->sd_strtab; dp = &devimpl[getmajor(vp->v_rdev)]; ASSERT(dp->d_str == str); qflag = dp->d_qflag; sqtype = dp->d_sqtype; /* create perdm_t if needed */ if (NEED_DM(dp->d_dmp, qflag)) dp->d_dmp = hold_dm(str, qflag, sqtype); dmp = dp->d_dmp; setq(rq, str->st_muxrinit, str->st_muxwinit, dmp, qflag, sqtype, B_TRUE); /* * XXX Remove any "odd" messages from the queue. * Keep only M_DATA, M_PROTO, M_PCPROTO. */ error = strdoioctl(stp, &strioc, FNATIVE, K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); if (error != 0) { lbfree(linkp); if (!(passyncq->sq_flags & SQ_BLOCKED)) blocksq(passyncq, SQ_BLOCKED, 0); /* * Restore the stream head queue and then remove * the passq. Turn off STPLEX before we turn on * the stream by removing the passq. */ rq->q_ptr = _WR(rq)->q_ptr = stpdown; setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_TRUE); mutex_enter(&stpdown->sd_lock); stpdown->sd_flag &= ~STPLEX; mutex_exit(&stpdown->sd_lock); link_rempassthru(passq); mutex_enter(&stpdown->sd_lock); stpdown->sd_flag &= ~STRPLUMB; /* Wakeup anyone waiting for STRPLUMB to clear. */ cv_broadcast(&stpdown->sd_monitor); mutex_exit(&stpdown->sd_lock); mutex_exit(&muxifier); return (error); } mutex_enter(&fpdown->f_tlock); fpdown->f_count++; mutex_exit(&fpdown->f_tlock); /* * if we've made it here the linkage is all set up so we should also * set up the layered driver linkages */ ASSERT((cmd == I_LINK) || (cmd == I_PLINK)); if (cmd == I_LINK) { ldi_mlink_fp(stp, fpdown, lhlink, LINKNORMAL); } else { ldi_mlink_fp(stp, fpdown, lhlink, LINKPERSIST); } link_rempassthru(passq); mux_addedge(stp, stpdown, linkp->li_lblk.l_index); /* * Mark the upper stream as having dependent links * so that strclose can clean it up. */ if (cmd == I_LINK) { mutex_enter(&stp->sd_lock); stp->sd_flag |= STRHASLINKS; mutex_exit(&stp->sd_lock); } /* * Wake up any other processes that may have been * waiting on the lower stream. These will all * error out. */ mutex_enter(&stpdown->sd_lock); /* The passthru module is removed so we may release STRPLUMB */ stpdown->sd_flag &= ~STRPLUMB; cv_broadcast(&rq->q_wait); cv_broadcast(&_WR(rq)->q_wait); cv_broadcast(&stpdown->sd_monitor); mutex_exit(&stpdown->sd_lock); mutex_exit(&muxifier); *rvalp = linkp->li_lblk.l_index; return (0); } int mlink(vnode_t *vp, int cmd, int arg, cred_t *crp, int *rvalp, int lhlink) { int ret; struct file *fpdown; fpdown = getf(arg); ret = mlink_file(vp, cmd, fpdown, crp, rvalp, lhlink); if (fpdown != NULL) releasef(arg); return (ret); } /* * Unlink a multiplexor link. Stp is the controlling stream for the * link, and linkp points to the link's entry in the linkinfo list. * The muxifier lock must be held on entry and is dropped on exit. * * NOTE : Currently it is assumed that mux would process all the messages * sitting on it's queue before ACKing the UNLINK. It is the responsibility * of the mux to handle all the messages that arrive before UNLINK. * If the mux has to send down messages on its lower stream before * ACKing I_UNLINK, then it *should* know to handle messages even * after the UNLINK is acked (actually it should be able to handle till we * re-block the read side of the pass queue here). If the mux does not * open up the lower stream, any messages that arrive during UNLINK * will be put in the stream head. In the case of lower stream opening * up, some messages might land in the stream head depending on when * the message arrived and when the read side of the pass queue was * re-blocked. */ int munlink(stdata_t *stp, linkinfo_t *linkp, int flag, cred_t *crp, int *rvalp) { struct strioctl strioc; struct stdata *stpdown; queue_t *rq, *wrq; queue_t *passq; syncq_t *passyncq; int error = 0; file_t *fpdown; ASSERT(MUTEX_HELD(&muxifier)); stpdown = linkp->li_fpdown->f_vnode->v_stream; /* * See the comment in mlink() concerning STRPLUMB/STPLEX flags. */ mutex_enter(&stpdown->sd_lock); stpdown->sd_flag |= STRPLUMB; mutex_exit(&stpdown->sd_lock); /* * Add passthru queue below lower mux. This will block * syncqs of lower muxs read queue during I_LINK/I_UNLINK. */ passq = link_addpassthru(stpdown); if ((flag & LINKTYPEMASK) == LINKNORMAL) strioc.ic_cmd = I_UNLINK; else strioc.ic_cmd = I_PUNLINK; strioc.ic_timout = INFTIM; strioc.ic_len = sizeof (struct linkblk); strioc.ic_dp = (char *)&linkp->li_lblk; error = strdoioctl(stp, &strioc, FNATIVE, K_TO_K | STR_NOERROR | STR_NOSIG, crp, rvalp); /* * If there was an error and this is not called via strclose, * return to the user. Otherwise, pretend there was no error * and close the link. */ if (error) { if (flag & LINKCLOSE) { cmn_err(CE_WARN, "KERNEL: munlink: could not perform " "unlink ioctl, closing anyway (%d)\n", error); } else { link_rempassthru(passq); mutex_enter(&stpdown->sd_lock); stpdown->sd_flag &= ~STRPLUMB; cv_broadcast(&stpdown->sd_monitor); mutex_exit(&stpdown->sd_lock); mutex_exit(&muxifier); return (error); } } mux_rmvedge(stp, linkp->li_lblk.l_index); fpdown = linkp->li_fpdown; lbfree(linkp); /* * We go ahead and drop muxifier here--it's a nasty global lock that * can slow others down. It's okay to since attempts to mlink() this * stream will be stopped because STPLEX is still set in the stdata * structure, and munlink() is stopped because mux_rmvedge() and * lbfree() have removed it from mux_nodes[] and linkinfo_list, * respectively. Note that we defer the closef() of fpdown until * after we drop muxifier since strclose() can call munlinkall(). */ mutex_exit(&muxifier); wrq = stpdown->sd_wrq; rq = _RD(wrq); /* * Get rid of outstanding service procedure runs, before we make * it a stream head, since a stream head doesn't have any service * procedure. */ disable_svc(rq); wait_svc(rq); /* * Since we don't disable the syncq for QPERMOD, we wait for whatever * is queued up to be finished. mux should take care that nothing is * send down to this queue. We should do it now as we're going to block * passyncq if it was unblocked. */ if (wrq->q_flag & QPERMOD) { syncq_t *sq = wrq->q_syncq; mutex_enter(SQLOCK(sq)); while (wrq->q_sqflags & Q_SQQUEUED) { sq->sq_flags |= SQ_WANTWAKEUP; cv_wait(&sq->sq_wait, SQLOCK(sq)); } mutex_exit(SQLOCK(sq)); } passyncq = passq->q_syncq; if (!(passyncq->sq_flags & SQ_BLOCKED)) { syncq_t *sq, *outer; /* * Messages could be flowing from underneath. We will * block the read side of the passq. This would be * sufficient for QPAIR and QPERQ muxes to ensure * that no data is flowing up into this queue * and hence no thread active in this instance of * lower mux. But for QPERMOD and QMTOUTPERIM there * could be messages on the inner and outer/inner * syncqs respectively. We will wait for them to drain. * Because passq is blocked messages end up in the syncq * And qfill_syncq could possibly end up setting QFULL * which will access the rq->q_flag. Hence, we have to * acquire the QLOCK in setq. * * XXX Messages can also flow from top into this * queue though the unlink is over (Ex. some instance * in putnext() called from top that has still not * accessed this queue. And also putq(lowerq) ?). * Solution : How about blocking the l_qtop queue ? * Do we really care about such pure D_MP muxes ? */ blocksq(passyncq, SQ_BLOCKED, 0); sq = rq->q_syncq; if ((outer = sq->sq_outer) != NULL) { /* * We have to just wait for the outer sq_count * drop to zero. As this does not prevent new * messages to enter the outer perimeter, this * is subject to starvation. * * NOTE :Because of blocksq above, messages could * be in the inner syncq only because of some * thread holding the outer perimeter exclusively. * Hence it would be sufficient to wait for the * exclusive holder of the outer perimeter to drain * the inner and outer syncqs. But we will not depend * on this feature and hence check the inner syncqs * separately. */ wait_syncq(outer); } /* * There could be messages destined for * this queue. Let the exclusive holder * drain it. */ wait_syncq(sq); ASSERT((rq->q_flag & QPERMOD) || ((rq->q_syncq->sq_head == NULL) && (_WR(rq)->q_syncq->sq_head == NULL))); } /* * We haven't taken care of QPERMOD case yet. QPERMOD is a special * case as we don't disable its syncq or remove it off the syncq * service list. */ if (rq->q_flag & QPERMOD) { syncq_t *sq = rq->q_syncq; mutex_enter(SQLOCK(sq)); while (rq->q_sqflags & Q_SQQUEUED) { sq->sq_flags |= SQ_WANTWAKEUP; cv_wait(&sq->sq_wait, SQLOCK(sq)); } mutex_exit(SQLOCK(sq)); } /* * flush_syncq changes states only when there is some messages to * free. ie when it returns non-zero value to return. */ ASSERT(flush_syncq(rq->q_syncq, rq) == 0); ASSERT(flush_syncq(wrq->q_syncq, wrq) == 0); /* * No body else should know about this queue now. * If the mux did not process the messages before * acking the I_UNLINK, free them now. */ flushq(rq, FLUSHALL); flushq(_WR(rq), FLUSHALL); /* * Convert the mux lower queue into a stream head queue. * Turn off STPLEX before we turn on the stream by removing the passq. */ rq->q_ptr = wrq->q_ptr = stpdown; setq(rq, &strdata, &stwdata, NULL, QMTSAFE, SQ_CI|SQ_CO, B_TRUE); ASSERT((rq->q_flag & QMT_TYPEMASK) == QMTSAFE); ASSERT(rq->q_syncq == SQ(rq) && _WR(rq)->q_syncq == SQ(rq)); enable_svc(rq); /* * Now it is a proper stream, so STPLEX is cleared. But STRPLUMB still * needs to be set to prevent reopen() of the stream - such reopen may * try to call non-existent pass queue open routine and panic. */ mutex_enter(&stpdown->sd_lock); stpdown->sd_flag &= ~STPLEX; mutex_exit(&stpdown->sd_lock); ASSERT(((flag & LINKTYPEMASK) == LINKNORMAL) || ((flag & LINKTYPEMASK) == LINKPERSIST)); /* clean up the layered driver linkages */ if ((flag & LINKTYPEMASK) == LINKNORMAL) { ldi_munlink_fp(stp, fpdown, LINKNORMAL); } else { ldi_munlink_fp(stp, fpdown, LINKPERSIST); } link_rempassthru(passq); /* * Now all plumbing changes are finished and STRPLUMB is no * longer needed. */ mutex_enter(&stpdown->sd_lock); stpdown->sd_flag &= ~STRPLUMB; cv_broadcast(&stpdown->sd_monitor); mutex_exit(&stpdown->sd_lock); (void) closef(fpdown); return (0); } /* * Unlink all multiplexor links for which stp is the controlling stream. * Return 0, or a non-zero errno on failure. */ int munlinkall(stdata_t *stp, int flag, cred_t *crp, int *rvalp) { linkinfo_t *linkp; int error = 0; mutex_enter(&muxifier); while (linkp = findlinks(stp, 0, flag)) { /* * munlink() releases the muxifier lock. */ if (error = munlink(stp, linkp, flag, crp, rvalp)) return (error); mutex_enter(&muxifier); } mutex_exit(&muxifier); return (0); } /* * A multiplexor link has been made. Add an * edge to the directed graph. */ void mux_addedge(stdata_t *upstp, stdata_t *lostp, int muxid) { struct mux_node *np; struct mux_edge *ep; major_t upmaj; major_t lomaj; upmaj = getmajor(upstp->sd_vnode->v_rdev); lomaj = getmajor(lostp->sd_vnode->v_rdev); np = &mux_nodes[upmaj]; if (np->mn_outp) { ep = np->mn_outp; while (ep->me_nextp) ep = ep->me_nextp; ep->me_nextp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); ep = ep->me_nextp; } else { np->mn_outp = kmem_alloc(sizeof (struct mux_edge), KM_SLEEP); ep = np->mn_outp; } ep->me_nextp = NULL; ep->me_muxid = muxid; if (lostp->sd_vnode->v_type == VFIFO) ep->me_nodep = NULL; else ep->me_nodep = &mux_nodes[lomaj]; } /* * A multiplexor link has been removed. Remove the * edge in the directed graph. */ void mux_rmvedge(stdata_t *upstp, int muxid) { struct mux_node *np; struct mux_edge *ep; struct mux_edge *pep = NULL; major_t upmaj; upmaj = getmajor(upstp->sd_vnode->v_rdev); np = &mux_nodes[upmaj]; ASSERT(np->mn_outp != NULL); ep = np->mn_outp; while (ep) { if (ep->me_muxid == muxid) { if (pep) pep->me_nextp = ep->me_nextp; else np->mn_outp = ep->me_nextp; kmem_free(ep, sizeof (struct mux_edge)); return; } pep = ep; ep = ep->me_nextp; } ASSERT(0); /* should not reach here */ } /* * Translate the device flags (from conf.h) to the corresponding * qflag and sq_flag (type) values. */ int devflg_to_qflag(struct streamtab *stp, uint32_t devflag, uint32_t *qflagp, uint32_t *sqtypep) { uint32_t qflag = 0; uint32_t sqtype = 0; if (devflag & _D_OLD) goto bad; /* Inner perimeter presence and scope */ switch (devflag & D_MTINNER_MASK) { case D_MP: qflag |= QMTSAFE; sqtype |= SQ_CI; break; case D_MTPERQ|D_MP: qflag |= QPERQ; break; case D_MTQPAIR|D_MP: qflag |= QPAIR; break; case D_MTPERMOD|D_MP: qflag |= QPERMOD; break; default: goto bad; } /* Outer perimeter */ if (devflag & D_MTOUTPERIM) { switch (devflag & D_MTINNER_MASK) { case D_MP: case D_MTPERQ|D_MP: case D_MTQPAIR|D_MP: break; default: goto bad; } qflag |= QMTOUTPERIM; } /* Inner perimeter modifiers */ if (devflag & D_MTINNER_MOD) { switch (devflag & D_MTINNER_MASK) { case D_MP: goto bad; default: break; } if (devflag & D_MTPUTSHARED) sqtype |= SQ_CIPUT; if (devflag & _D_MTOCSHARED) { /* * The code in putnext assumes that it has the * highest concurrency by not checking sq_count. * Thus _D_MTOCSHARED can only be supported when * D_MTPUTSHARED is set. */ if (!(devflag & D_MTPUTSHARED)) goto bad; sqtype |= SQ_CIOC; } if (devflag & _D_MTCBSHARED) { /* * The code in putnext assumes that it has the * highest concurrency by not checking sq_count. * Thus _D_MTCBSHARED can only be supported when * D_MTPUTSHARED is set. */ if (!(devflag & D_MTPUTSHARED)) goto bad; sqtype |= SQ_CICB; } if (devflag & _D_MTSVCSHARED) { /* * The code in putnext assumes that it has the * highest concurrency by not checking sq_count. * Thus _D_MTSVCSHARED can only be supported when * D_MTPUTSHARED is set. Also _D_MTSVCSHARED is * supported only for QPERMOD. */ if (!(devflag & D_MTPUTSHARED) || !(qflag & QPERMOD)) goto bad; sqtype |= SQ_CISVC; } } /* Default outer perimeter concurrency */ sqtype |= SQ_CO; /* Outer perimeter modifiers */ if (devflag & D_MTOCEXCL) { if (!(devflag & D_MTOUTPERIM)) { /* No outer perimeter */ goto bad; } sqtype &= ~SQ_COOC; } /* Synchronous Streams extended qinit structure */ if (devflag & D_SYNCSTR) qflag |= QSYNCSTR; *qflagp = qflag; *sqtypep = sqtype; return (0); bad: cmn_err(CE_WARN, "stropen: bad MT flags (0x%x) in driver '%s'", (int)(qflag & D_MTSAFETY_MASK), stp->st_rdinit->qi_minfo->mi_idname); return (EINVAL); } /* * Set the interface values for a pair of queues (qinit structure, * packet sizes, water marks). * setq assumes that the caller does not have a claim (entersq or claimq) * on the queue. */ void setq(queue_t *rq, struct qinit *rinit, struct qinit *winit, perdm_t *dmp, uint32_t qflag, uint32_t sqtype, boolean_t lock_needed) { queue_t *wq; syncq_t *sq, *outer; ASSERT(rq->q_flag & QREADR); ASSERT((qflag & QMT_TYPEMASK) != 0); IMPLY((qflag & (QPERMOD | QMTOUTPERIM)), dmp != NULL); wq = _WR(rq); rq->q_qinfo = rinit; rq->q_hiwat = rinit->qi_minfo->mi_hiwat; rq->q_lowat = rinit->qi_minfo->mi_lowat; rq->q_minpsz = rinit->qi_minfo->mi_minpsz; rq->q_maxpsz = rinit->qi_minfo->mi_maxpsz; wq->q_qinfo = winit; wq->q_hiwat = winit->qi_minfo->mi_hiwat; wq->q_lowat = winit->qi_minfo->mi_lowat; wq->q_minpsz = winit->qi_minfo->mi_minpsz; wq->q_maxpsz = winit->qi_minfo->mi_maxpsz; /* Remove old syncqs */ sq = rq->q_syncq; outer = sq->sq_outer; if (outer != NULL) { ASSERT(wq->q_syncq->sq_outer == outer); outer_remove(outer, rq->q_syncq); if (wq->q_syncq != rq->q_syncq) outer_remove(outer, wq->q_syncq); } ASSERT(sq->sq_outer == NULL); ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); if (sq != SQ(rq)) { if (!(rq->q_flag & QPERMOD)) free_syncq(sq); if (wq->q_syncq == rq->q_syncq) wq->q_syncq = NULL; rq->q_syncq = NULL; } if (wq->q_syncq != NULL && wq->q_syncq != sq && wq->q_syncq != SQ(rq)) { free_syncq(wq->q_syncq); wq->q_syncq = NULL; } ASSERT(rq->q_syncq == NULL || (rq->q_syncq->sq_head == NULL && rq->q_syncq->sq_tail == NULL)); ASSERT(wq->q_syncq == NULL || (wq->q_syncq->sq_head == NULL && wq->q_syncq->sq_tail == NULL)); if (!(rq->q_flag & QPERMOD) && rq->q_syncq != NULL && rq->q_syncq->sq_ciputctrl != NULL) { ASSERT(rq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); SUMCHECK_CIPUTCTRL_COUNTS(rq->q_syncq->sq_ciputctrl, rq->q_syncq->sq_nciputctrl, 0); ASSERT(ciputctrl_cache != NULL); kmem_cache_free(ciputctrl_cache, rq->q_syncq->sq_ciputctrl); rq->q_syncq->sq_ciputctrl = NULL; rq->q_syncq->sq_nciputctrl = 0; } if (!(wq->q_flag & QPERMOD) && wq->q_syncq != NULL && wq->q_syncq->sq_ciputctrl != NULL) { ASSERT(wq->q_syncq->sq_nciputctrl == n_ciputctrl - 1); SUMCHECK_CIPUTCTRL_COUNTS(wq->q_syncq->sq_ciputctrl, wq->q_syncq->sq_nciputctrl, 0); ASSERT(ciputctrl_cache != NULL); kmem_cache_free(ciputctrl_cache, wq->q_syncq->sq_ciputctrl); wq->q_syncq->sq_ciputctrl = NULL; wq->q_syncq->sq_nciputctrl = 0; } sq = SQ(rq); ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); ASSERT(sq->sq_outer == NULL); ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); /* * Create syncqs based on qflag and sqtype. Set the SQ_TYPES_IN_FLAGS * bits in sq_flag based on the sqtype. */ ASSERT((sq->sq_flags & ~SQ_TYPES_IN_FLAGS) == 0); rq->q_syncq = wq->q_syncq = sq; sq->sq_type = sqtype; sq->sq_flags = (sqtype & SQ_TYPES_IN_FLAGS); /* * We are making sq_svcflags zero, * resetting SQ_DISABLED in case it was set by * wait_svc() in the munlink path. * */ ASSERT((sq->sq_svcflags & SQ_SERVICE) == 0); sq->sq_svcflags = 0; /* * We need to acquire the lock here for the mlink and munlink case, * where canputnext, backenable, etc can access the q_flag. */ if (lock_needed) { mutex_enter(QLOCK(rq)); rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; mutex_exit(QLOCK(rq)); mutex_enter(QLOCK(wq)); wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; mutex_exit(QLOCK(wq)); } else { rq->q_flag = (rq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; wq->q_flag = (wq->q_flag & ~QMT_TYPEMASK) | QWANTR | qflag; } if (qflag & QPERQ) { /* Allocate a separate syncq for the write side */ sq = new_syncq(); sq->sq_type = rq->q_syncq->sq_type; sq->sq_flags = rq->q_syncq->sq_flags; ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL); wq->q_syncq = sq; } if (qflag & QPERMOD) { sq = dmp->dm_sq; /* * Assert that we do have an inner perimeter syncq and that it * does not have an outer perimeter associated with it. */ ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL); rq->q_syncq = wq->q_syncq = sq; } if (qflag & QMTOUTPERIM) { outer = dmp->dm_sq; ASSERT(outer->sq_outer == NULL); outer_insert(outer, rq->q_syncq); if (wq->q_syncq != rq->q_syncq) outer_insert(outer, wq->q_syncq); } ASSERT((rq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == (rq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); ASSERT((wq->q_syncq->sq_flags & SQ_TYPES_IN_FLAGS) == (wq->q_syncq->sq_type & SQ_TYPES_IN_FLAGS)); ASSERT((rq->q_flag & QMT_TYPEMASK) == (qflag & QMT_TYPEMASK)); /* * Initialize struio() types. */ rq->q_struiot = (rq->q_flag & QSYNCSTR) ? rinit->qi_struiot : STRUIOT_NONE; wq->q_struiot = (wq->q_flag & QSYNCSTR) ? winit->qi_struiot : STRUIOT_NONE; } perdm_t * hold_dm(struct streamtab *str, uint32_t qflag, uint32_t sqtype) { syncq_t *sq; perdm_t **pp; perdm_t *p; perdm_t *dmp; ASSERT(str != NULL); ASSERT(qflag & (QPERMOD | QMTOUTPERIM)); rw_enter(&perdm_rwlock, RW_READER); for (p = perdm_list; p != NULL; p = p->dm_next) { if (p->dm_str == str) { /* found one */ atomic_add_32(&(p->dm_ref), 1); rw_exit(&perdm_rwlock); return (p); } } rw_exit(&perdm_rwlock); sq = new_syncq(); if (qflag & QPERMOD) { sq->sq_type = sqtype | SQ_PERMOD; sq->sq_flags = sqtype & SQ_TYPES_IN_FLAGS; } else { ASSERT(qflag & QMTOUTPERIM); sq->sq_onext = sq->sq_oprev = sq; } dmp = kmem_alloc(sizeof (perdm_t), KM_SLEEP); dmp->dm_sq = sq; dmp->dm_str = str; dmp->dm_ref = 1; dmp->dm_next = NULL; rw_enter(&perdm_rwlock, RW_WRITER); for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) { if (p->dm_str == str) { /* already present */ p->dm_ref++; rw_exit(&perdm_rwlock); free_syncq(sq); kmem_free(dmp, sizeof (perdm_t)); return (p); } } *pp = dmp; rw_exit(&perdm_rwlock); return (dmp); } void rele_dm(perdm_t *dmp) { perdm_t **pp; perdm_t *p; rw_enter(&perdm_rwlock, RW_WRITER); ASSERT(dmp->dm_ref > 0); if (--dmp->dm_ref > 0) { rw_exit(&perdm_rwlock); return; } for (pp = &perdm_list; (p = *pp) != NULL; pp = &(p->dm_next)) if (p == dmp) break; ASSERT(p == dmp); *pp = p->dm_next; rw_exit(&perdm_rwlock); /* * Wait for any background processing that relies on the * syncq to complete before it is freed. */ wait_sq_svc(p->dm_sq); free_syncq(p->dm_sq); kmem_free(p, sizeof (perdm_t)); } /* * Make a protocol message given control and data buffers. * n.b., this can block; be careful of what locks you hold when calling it. * * If sd_maxblk is less than *iosize this routine can fail part way through * (due to an allocation failure). In this case on return *iosize will contain * the amount that was consumed. Otherwise *iosize will not be modified * i.e. it will contain the amount that was consumed. */ int strmakemsg( struct strbuf *mctl, ssize_t *iosize, struct uio *uiop, stdata_t *stp, int32_t flag, mblk_t **mpp) { mblk_t *mpctl = NULL; mblk_t *mpdata = NULL; int error; ASSERT(uiop != NULL); *mpp = NULL; /* Create control part, if any */ if ((mctl != NULL) && (mctl->len >= 0)) { error = strmakectl(mctl, flag, uiop->uio_fmode, &mpctl); if (error) return (error); } /* Create data part, if any */ if (*iosize >= 0) { error = strmakedata(iosize, uiop, stp, flag, &mpdata); if (error) { freemsg(mpctl); return (error); } } if (mpctl != NULL) { if (mpdata != NULL) linkb(mpctl, mpdata); *mpp = mpctl; } else { *mpp = mpdata; } return (0); } /* * Make the control part of a protocol message given a control buffer. * n.b., this can block; be careful of what locks you hold when calling it. */ int strmakectl( struct strbuf *mctl, int32_t flag, int32_t fflag, mblk_t **mpp) { mblk_t *bp = NULL; unsigned char msgtype; int error = 0; *mpp = NULL; /* * Create control part of message, if any. */ if ((mctl != NULL) && (mctl->len >= 0)) { caddr_t base; int ctlcount; int allocsz; if (flag & RS_HIPRI) msgtype = M_PCPROTO; else msgtype = M_PROTO; ctlcount = mctl->len; base = mctl->buf; /* * Give modules a better chance to reuse M_PROTO/M_PCPROTO * blocks by increasing the size to something more usable. */ allocsz = MAX(ctlcount, 64); /* * Range checking has already been done; simply try * to allocate a message block for the ctl part. */ while (!(bp = allocb(allocsz, BPRI_MED))) { if (fflag & (FNDELAY|FNONBLOCK)) return (EAGAIN); if (error = strwaitbuf(allocsz, BPRI_MED)) return (error); } bp->b_datap->db_type = msgtype; if (copyin(base, bp->b_wptr, ctlcount)) { freeb(bp); return (EFAULT); } bp->b_wptr += ctlcount; } *mpp = bp; return (0); } /* * Make a protocol message given data buffers. * n.b., this can block; be careful of what locks you hold when calling it. * * If sd_maxblk is less than *iosize this routine can fail part way through * (due to an allocation failure). In this case on return *iosize will contain * the amount that was consumed. Otherwise *iosize will not be modified * i.e. it will contain the amount that was consumed. */ int strmakedata( ssize_t *iosize, struct uio *uiop, stdata_t *stp, int32_t flag, mblk_t **mpp) { mblk_t *mp = NULL; mblk_t *bp; int wroff = (int)stp->sd_wroff; int error = 0; ssize_t maxblk; ssize_t count = *iosize; cred_t *cr = CRED(); *mpp = NULL; if (count < 0) return (0); maxblk = stp->sd_maxblk; if (maxblk == INFPSZ) maxblk = count; /* * Create data part of message, if any. */ do { ssize_t size; dblk_t *dp; ASSERT(uiop); size = MIN(count, maxblk); while ((bp = allocb_cred(size + wroff, cr)) == NULL) { error = EAGAIN; if ((uiop->uio_fmode & (FNDELAY|FNONBLOCK)) || (error = strwaitbuf(size + wroff, BPRI_MED)) != 0) { if (count == *iosize) { freemsg(mp); return (error); } else { *iosize -= count; *mpp = mp; return (0); } } } dp = bp->b_datap; dp->db_cpid = curproc->p_pid; ASSERT(wroff <= dp->db_lim - bp->b_wptr); bp->b_wptr = bp->b_rptr = bp->b_rptr + wroff; if (flag & STRUIO_POSTPONE) { /* * Setup the stream uio portion of the * dblk for subsequent use by struioget(). */ dp->db_struioflag = STRUIO_SPEC; dp->db_cksumstart = 0; dp->db_cksumstuff = 0; dp->db_cksumend = size; *(long long *)dp->db_struioun.data = 0ll; } else { if (stp->sd_copyflag & STRCOPYCACHED) uiop->uio_extflg |= UIO_COPY_CACHED; if (size != 0) { error = uiomove(bp->b_wptr, size, UIO_WRITE, uiop); if (error != 0) { freeb(bp); freemsg(mp); return (error); } } } bp->b_wptr += size; count -= size; if (mp == NULL) mp = bp; else linkb(mp, bp); } while (count > 0); *mpp = mp; return (0); } /* * Wait for a buffer to become available. Return non-zero errno * if not able to wait, 0 if buffer is probably there. */ int strwaitbuf(size_t size, int pri) { bufcall_id_t id; mutex_enter(&bcall_monitor); if ((id = bufcall(size, pri, (void (*)(void *))cv_broadcast, &ttoproc(curthread)->p_flag_cv)) == 0) { mutex_exit(&bcall_monitor); return (ENOSR); } if (!cv_wait_sig(&(ttoproc(curthread)->p_flag_cv), &bcall_monitor)) { unbufcall(id); mutex_exit(&bcall_monitor); return (EINTR); } unbufcall(id); mutex_exit(&bcall_monitor); return (0); } /* * This function waits for a read or write event to happen on a stream. * fmode can specify FNDELAY and/or FNONBLOCK. * The timeout is in ms with -1 meaning infinite. * The flag values work as follows: * READWAIT Check for read side errors, send M_READ * GETWAIT Check for read side errors, no M_READ * WRITEWAIT Check for write side errors. * NOINTR Do not return error if nonblocking or timeout. * STR_NOERROR Ignore all errors except STPLEX. * STR_NOSIG Ignore/hold signals during the duration of the call. * STR_PEEK Pass through the strgeterr(). */ int strwaitq(stdata_t *stp, int flag, ssize_t count, int fmode, clock_t timout, int *done) { int slpflg, errs; int error; kcondvar_t *sleepon; mblk_t *mp; ssize_t *rd_count; clock_t rval; ASSERT(MUTEX_HELD(&stp->sd_lock)); if ((flag & READWAIT) || (flag & GETWAIT)) { slpflg = RSLEEP; sleepon = &_RD(stp->sd_wrq)->q_wait; errs = STRDERR|STPLEX; } else { slpflg = WSLEEP; sleepon = &stp->sd_wrq->q_wait; errs = STWRERR|STRHUP|STPLEX; } if (flag & STR_NOERROR) errs = STPLEX; if (stp->sd_wakeq & slpflg) { /* * A strwakeq() is pending, no need to sleep. */ stp->sd_wakeq &= ~slpflg; *done = 0; return (0); } if (fmode & (FNDELAY|FNONBLOCK)) { if (!(flag & NOINTR)) error = EAGAIN; else error = 0; *done = 1; return (error); } if (stp->sd_flag & errs) { /* * Check for errors before going to sleep since the * caller might not have checked this while holding * sd_lock. */ error = strgeterr(stp, errs, (flag & STR_PEEK)); if (error != 0) { *done = 1; return (error); } } /* * If any module downstream has requested read notification * by setting SNDMREAD flag using M_SETOPTS, send a message * down stream. */ if ((flag & READWAIT) && (stp->sd_flag & SNDMREAD)) { mutex_exit(&stp->sd_lock); if (!(mp = allocb_wait(sizeof (ssize_t), BPRI_MED, (flag & STR_NOSIG), &error))) { mutex_enter(&stp->sd_lock); *done = 1; return (error); } mp->b_datap->db_type = M_READ; rd_count = (ssize_t *)mp->b_wptr; *rd_count = count; mp->b_wptr += sizeof (ssize_t); /* * Send the number of bytes requested by the * read as the argument to M_READ. */ stream_willservice(stp); putnext(stp->sd_wrq, mp); stream_runservice(stp); mutex_enter(&stp->sd_lock); /* * If any data arrived due to inline processing * of putnext(), don't sleep. */ if (_RD(stp->sd_wrq)->q_first != NULL) { *done = 0; return (0); } } stp->sd_flag |= slpflg; TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAIT2, "strwaitq sleeps (2):%p, %X, %lX, %X, %p", stp, flag, count, fmode, done); rval = str_cv_wait(sleepon, &stp->sd_lock, timout, flag & STR_NOSIG); if (rval > 0) { /* EMPTY */ TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_WAKE2, "strwaitq awakes(2):%X, %X, %X, %X, %X", stp, flag, count, fmode, done); } else if (rval == 0) { TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_INTR2, "strwaitq interrupt #2:%p, %X, %lX, %X, %p", stp, flag, count, fmode, done); stp->sd_flag &= ~slpflg; cv_broadcast(sleepon); if (!(flag & NOINTR)) error = EINTR; else error = 0; *done = 1; return (error); } else { /* timeout */ TRACE_5(TR_FAC_STREAMS_FR, TR_STRWAITQ_TIME, "strwaitq timeout:%p, %X, %lX, %X, %p", stp, flag, count, fmode, done); *done = 1; if (!(flag & NOINTR)) return (ETIME); else return (0); } /* * If the caller implements delayed errors (i.e. queued after data) * we can not check for errors here since data as well as an * error might have arrived at the stream head. We return to * have the caller check the read queue before checking for errors. */ if ((stp->sd_flag & errs) && !(flag & STR_DELAYERR)) { error = strgeterr(stp, errs, (flag & STR_PEEK)); if (error != 0) { *done = 1; return (error); } } *done = 0; return (0); } /* * Perform job control discipline access checks. * Return 0 for success and the errno for failure. */ #define cantsend(p, t, sig) \ (sigismember(&(p)->p_ignore, sig) || signal_is_blocked((t), sig)) int straccess(struct stdata *stp, enum jcaccess mode) { extern kcondvar_t lbolt_cv; /* XXX: should be in a header file */ kthread_t *t = curthread; proc_t *p = ttoproc(t); sess_t *sp; if (stp->sd_sidp == NULL || stp->sd_vnode->v_type == VFIFO) return (0); mutex_enter(&p->p_lock); sp = p->p_sessp; for (;;) { /* * If this is not the calling process's controlling terminal * or if the calling process is already in the foreground * then allow access. */ if (sp->s_dev != stp->sd_vnode->v_rdev || p->p_pgidp == stp->sd_pgidp) { mutex_exit(&p->p_lock); return (0); } /* * Check to see if controlling terminal has been deallocated. */ if (sp->s_vp == NULL) { if (!cantsend(p, t, SIGHUP)) sigtoproc(p, t, SIGHUP); mutex_exit(&p->p_lock); return (EIO); } if (mode == JCGETP) { mutex_exit(&p->p_lock); return (0); } if (mode == JCREAD) { if (p->p_detached || cantsend(p, t, SIGTTIN)) { mutex_exit(&p->p_lock); return (EIO); } mutex_exit(&p->p_lock); pgsignal(p->p_pgidp, SIGTTIN); mutex_enter(&p->p_lock); } else { /* mode == JCWRITE or JCSETP */ if ((mode == JCWRITE && !(stp->sd_flag & STRTOSTOP)) || cantsend(p, t, SIGTTOU)) { mutex_exit(&p->p_lock); return (0); } if (p->p_detached) { mutex_exit(&p->p_lock); return (EIO); } mutex_exit(&p->p_lock); pgsignal(p->p_pgidp, SIGTTOU); mutex_enter(&p->p_lock); } /* * We call cv_wait_sig_swap() to cause the appropriate * action for the jobcontrol signal to take place. * If the signal is being caught, we will take the * EINTR error return. Otherwise, the default action * of causing the process to stop will take place. * In this case, we rely on the periodic cv_broadcast() on * &lbolt_cv to wake us up to loop around and test again. * We can't get here if the signal is ignored or * if the current thread is blocking the signal. */ if (!cv_wait_sig_swap(&lbolt_cv, &p->p_lock)) { mutex_exit(&p->p_lock); return (EINTR); } } } /* * Return size of message of block type (bp->b_datap->db_type) */ size_t xmsgsize(mblk_t *bp) { unsigned char type; size_t count = 0; type = bp->b_datap->db_type; for (; bp; bp = bp->b_cont) { if (type != bp->b_datap->db_type) break; ASSERT(bp->b_wptr >= bp->b_rptr); count += bp->b_wptr - bp->b_rptr; } return (count); } /* * Allocate a stream head. */ struct stdata * shalloc(queue_t *qp) { stdata_t *stp; stp = kmem_cache_alloc(stream_head_cache, KM_SLEEP); stp->sd_wrq = _WR(qp); stp->sd_strtab = NULL; stp->sd_iocid = 0; stp->sd_mate = NULL; stp->sd_freezer = NULL; stp->sd_refcnt = 0; stp->sd_wakeq = 0; stp->sd_anchor = 0; stp->sd_struiowrq = NULL; stp->sd_struiordq = NULL; stp->sd_struiodnak = 0; stp->sd_struionak = NULL; #ifdef C2_AUDIT stp->sd_t_audit_data = NULL; #endif stp->sd_rput_opt = 0; stp->sd_wput_opt = 0; stp->sd_read_opt = 0; stp->sd_rprotofunc = strrput_proto; stp->sd_rmiscfunc = strrput_misc; stp->sd_rderrfunc = stp->sd_wrerrfunc = NULL; stp->sd_ciputctrl = NULL; stp->sd_nciputctrl = 0; stp->sd_qhead = NULL; stp->sd_qtail = NULL; stp->sd_servid = NULL; stp->sd_nqueues = 0; stp->sd_svcflags = 0; stp->sd_copyflag = 0; return (stp); } /* * Free a stream head. */ void shfree(stdata_t *stp) { ASSERT(MUTEX_NOT_HELD(&stp->sd_lock)); stp->sd_wrq = NULL; mutex_enter(&stp->sd_qlock); while (stp->sd_svcflags & STRS_SCHEDULED) { STRSTAT(strwaits); cv_wait(&stp->sd_qcv, &stp->sd_qlock); } mutex_exit(&stp->sd_qlock); if (stp->sd_ciputctrl != NULL) { ASSERT(stp->sd_nciputctrl == n_ciputctrl - 1); SUMCHECK_CIPUTCTRL_COUNTS(stp->sd_ciputctrl, stp->sd_nciputctrl, 0); ASSERT(ciputctrl_cache != NULL); kmem_cache_free(ciputctrl_cache, stp->sd_ciputctrl); stp->sd_ciputctrl = NULL; stp->sd_nciputctrl = 0; } ASSERT(stp->sd_qhead == NULL); ASSERT(stp->sd_qtail == NULL); ASSERT(stp->sd_nqueues == 0); kmem_cache_free(stream_head_cache, stp); } /* * Allocate a pair of queues and a syncq for the pair */ queue_t * allocq(void) { queinfo_t *qip; queue_t *qp, *wqp; syncq_t *sq; qip = kmem_cache_alloc(queue_cache, KM_SLEEP); qp = &qip->qu_rqueue; wqp = &qip->qu_wqueue; sq = &qip->qu_syncq; qp->q_last = NULL; qp->q_next = NULL; qp->q_ptr = NULL; qp->q_flag = QUSE | QREADR; qp->q_bandp = NULL; qp->q_stream = NULL; qp->q_syncq = sq; qp->q_nband = 0; qp->q_nfsrv = NULL; qp->q_draining = 0; qp->q_syncqmsgs = 0; qp->q_spri = 0; qp->q_qtstamp = 0; qp->q_sqtstamp = 0; qp->q_fp = NULL; wqp->q_last = NULL; wqp->q_next = NULL; wqp->q_ptr = NULL; wqp->q_flag = QUSE; wqp->q_bandp = NULL; wqp->q_stream = NULL; wqp->q_syncq = sq; wqp->q_nband = 0; wqp->q_nfsrv = NULL; wqp->q_draining = 0; wqp->q_syncqmsgs = 0; wqp->q_qtstamp = 0; wqp->q_sqtstamp = 0; wqp->q_spri = 0; sq->sq_count = 0; sq->sq_rmqcount = 0; sq->sq_flags = 0; sq->sq_type = 0; sq->sq_callbflags = 0; sq->sq_cancelid = 0; sq->sq_ciputctrl = NULL; sq->sq_nciputctrl = 0; sq->sq_needexcl = 0; sq->sq_svcflags = 0; return (qp); } /* * Free a pair of queues and the "attached" syncq. * Discard any messages left on the syncq(s), remove the syncq(s) from the * outer perimeter, and free the syncq(s) if they are not the "attached" syncq. */ void freeq(queue_t *qp) { qband_t *qbp, *nqbp; syncq_t *sq, *outer; queue_t *wqp = _WR(qp); ASSERT(qp->q_flag & QREADR); (void) flush_syncq(qp->q_syncq, qp); (void) flush_syncq(wqp->q_syncq, wqp); ASSERT(qp->q_syncqmsgs == 0 && wqp->q_syncqmsgs == 0); outer = qp->q_syncq->sq_outer; if (outer != NULL) { outer_remove(outer, qp->q_syncq); if (wqp->q_syncq != qp->q_syncq) outer_remove(outer, wqp->q_syncq); } /* * Free any syncqs that are outside what allocq returned. */ if (qp->q_syncq != SQ(qp) && !(qp->q_flag & QPERMOD)) free_syncq(qp->q_syncq); if (qp->q_syncq != wqp->q_syncq && wqp->q_syncq != SQ(qp)) free_syncq(wqp->q_syncq); ASSERT((qp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); ASSERT((wqp->q_sqflags & (Q_SQQUEUED | Q_SQDRAINING)) == 0); ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); ASSERT(MUTEX_NOT_HELD(QLOCK(wqp))); sq = SQ(qp); ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); ASSERT(sq->sq_head == NULL && sq->sq_tail == NULL); ASSERT(sq->sq_outer == NULL); ASSERT(sq->sq_onext == NULL && sq->sq_oprev == NULL); ASSERT(sq->sq_callbpend == NULL); ASSERT(sq->sq_needexcl == 0); if (sq->sq_ciputctrl != NULL) { ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, sq->sq_nciputctrl, 0); ASSERT(ciputctrl_cache != NULL); kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); sq->sq_ciputctrl = NULL; sq->sq_nciputctrl = 0; } ASSERT(qp->q_first == NULL && wqp->q_first == NULL); ASSERT(qp->q_count == 0 && wqp->q_count == 0); ASSERT(qp->q_mblkcnt == 0 && wqp->q_mblkcnt == 0); qp->q_flag &= ~QUSE; wqp->q_flag &= ~QUSE; /* NOTE: Uncomment the assert below once bugid 1159635 is fixed. */ /* ASSERT((qp->q_flag & QWANTW) == 0 && (wqp->q_flag & QWANTW) == 0); */ qbp = qp->q_bandp; while (qbp) { nqbp = qbp->qb_next; freeband(qbp); qbp = nqbp; } qbp = wqp->q_bandp; while (qbp) { nqbp = qbp->qb_next; freeband(qbp); qbp = nqbp; } kmem_cache_free(queue_cache, qp); } /* * Allocate a qband structure. */ qband_t * allocband(void) { qband_t *qbp; qbp = kmem_cache_alloc(qband_cache, KM_NOSLEEP); if (qbp == NULL) return (NULL); qbp->qb_next = NULL; qbp->qb_count = 0; qbp->qb_mblkcnt = 0; qbp->qb_first = NULL; qbp->qb_last = NULL; qbp->qb_flag = 0; return (qbp); } /* * Free a qband structure. */ void freeband(qband_t *qbp) { kmem_cache_free(qband_cache, qbp); } /* * Just like putnextctl(9F), except that allocb_wait() is used. * * Consolidation Private, and of course only callable from the stream head or * routines that may block. */ int putnextctl_wait(queue_t *q, int type) { mblk_t *bp; int error; if ((datamsg(type) && (type != M_DELAY)) || (bp = allocb_wait(0, BPRI_HI, 0, &error)) == NULL) return (0); bp->b_datap->db_type = (unsigned char)type; putnext(q, bp); return (1); } /* * run any possible bufcalls. */ void runbufcalls(void) { strbufcall_t *bcp; mutex_enter(&bcall_monitor); mutex_enter(&strbcall_lock); if (strbcalls.bc_head) { size_t count; int nevent; /* * count how many events are on the list * now so we can check to avoid looping * in low memory situations */ nevent = 0; for (bcp = strbcalls.bc_head; bcp; bcp = bcp->bc_next) nevent++; /* * get estimate of available memory from kmem_avail(). * awake all bufcall functions waiting for * memory whose request could be satisfied * by 'count' memory and let 'em fight for it. */ count = kmem_avail(); while ((bcp = strbcalls.bc_head) != NULL && nevent) { STRSTAT(bufcalls); --nevent; if (bcp->bc_size <= count) { bcp->bc_executor = curthread; mutex_exit(&strbcall_lock); (*bcp->bc_func)(bcp->bc_arg); mutex_enter(&strbcall_lock); bcp->bc_executor = NULL; cv_broadcast(&bcall_cv); strbcalls.bc_head = bcp->bc_next; kmem_free(bcp, sizeof (strbufcall_t)); } else { /* * too big, try again later - note * that nevent was decremented above * so we won't retry this one on this * iteration of the loop */ if (bcp->bc_next != NULL) { strbcalls.bc_head = bcp->bc_next; bcp->bc_next = NULL; strbcalls.bc_tail->bc_next = bcp; strbcalls.bc_tail = bcp; } } } if (strbcalls.bc_head == NULL) strbcalls.bc_tail = NULL; } mutex_exit(&strbcall_lock); mutex_exit(&bcall_monitor); } /* * actually run queue's service routine. */ static void runservice(queue_t *q) { qband_t *qbp; ASSERT(q->q_qinfo->qi_srvp); again: entersq(q->q_syncq, SQ_SVC); TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_START, "runservice starts:%p", q); if (!(q->q_flag & QWCLOSE)) (*q->q_qinfo->qi_srvp)(q); TRACE_1(TR_FAC_STREAMS_FR, TR_QRUNSERVICE_END, "runservice ends:(%p)", q); leavesq(q->q_syncq, SQ_SVC); mutex_enter(QLOCK(q)); if (q->q_flag & QENAB) { q->q_flag &= ~QENAB; mutex_exit(QLOCK(q)); goto again; } q->q_flag &= ~QINSERVICE; q->q_flag &= ~QBACK; for (qbp = q->q_bandp; qbp; qbp = qbp->qb_next) qbp->qb_flag &= ~QB_BACK; /* * Wakeup thread waiting for the service procedure * to be run (strclose and qdetach). */ cv_broadcast(&q->q_wait); mutex_exit(QLOCK(q)); } /* * Background processing of bufcalls. */ void streams_bufcall_service(void) { callb_cpr_t cprinfo; CALLB_CPR_INIT(&cprinfo, &strbcall_lock, callb_generic_cpr, "streams_bufcall_service"); mutex_enter(&strbcall_lock); for (;;) { if (strbcalls.bc_head != NULL && kmem_avail() > 0) { mutex_exit(&strbcall_lock); runbufcalls(); mutex_enter(&strbcall_lock); } if (strbcalls.bc_head != NULL) { clock_t wt, tick; STRSTAT(bcwaits); /* Wait for memory to become available */ CALLB_CPR_SAFE_BEGIN(&cprinfo); tick = SEC_TO_TICK(60); time_to_wait(&wt, tick); (void) cv_timedwait(&memavail_cv, &strbcall_lock, wt); CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); } /* Wait for new work to arrive */ if (strbcalls.bc_head == NULL) { CALLB_CPR_SAFE_BEGIN(&cprinfo); cv_wait(&strbcall_cv, &strbcall_lock); CALLB_CPR_SAFE_END(&cprinfo, &strbcall_lock); } } } /* * Background processing of streams background tasks which failed * taskq_dispatch. */ static void streams_qbkgrnd_service(void) { callb_cpr_t cprinfo; queue_t *q; CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, "streams_bkgrnd_service"); mutex_enter(&service_queue); for (;;) { /* * Wait for work to arrive. */ while ((freebs_list == NULL) && (qhead == NULL)) { CALLB_CPR_SAFE_BEGIN(&cprinfo); cv_wait(&services_to_run, &service_queue); CALLB_CPR_SAFE_END(&cprinfo, &service_queue); } /* * Handle all pending freebs requests to free memory. */ while (freebs_list != NULL) { mblk_t *mp = freebs_list; freebs_list = mp->b_next; mutex_exit(&service_queue); mblk_free(mp); mutex_enter(&service_queue); } /* * Run pending queues. */ while (qhead != NULL) { DQ(q, qhead, qtail, q_link); ASSERT(q != NULL); mutex_exit(&service_queue); queue_service(q); mutex_enter(&service_queue); } ASSERT(qhead == NULL && qtail == NULL); } } /* * Background processing of streams background tasks which failed * taskq_dispatch. */ static void streams_sqbkgrnd_service(void) { callb_cpr_t cprinfo; syncq_t *sq; CALLB_CPR_INIT(&cprinfo, &service_queue, callb_generic_cpr, "streams_sqbkgrnd_service"); mutex_enter(&service_queue); for (;;) { /* * Wait for work to arrive. */ while (sqhead == NULL) { CALLB_CPR_SAFE_BEGIN(&cprinfo); cv_wait(&syncqs_to_run, &service_queue); CALLB_CPR_SAFE_END(&cprinfo, &service_queue); } /* * Run pending syncqs. */ while (sqhead != NULL) { DQ(sq, sqhead, sqtail, sq_next); ASSERT(sq != NULL); ASSERT(sq->sq_svcflags & SQ_BGTHREAD); mutex_exit(&service_queue); syncq_service(sq); mutex_enter(&service_queue); } } } /* * Disable the syncq and wait for background syncq processing to complete. * If the syncq is placed on the sqhead/sqtail queue, try to remove it from the * list. */ void wait_sq_svc(syncq_t *sq) { mutex_enter(SQLOCK(sq)); sq->sq_svcflags |= SQ_DISABLED; if (sq->sq_svcflags & SQ_BGTHREAD) { syncq_t *sq_chase; syncq_t *sq_curr; int removed; ASSERT(sq->sq_servcount == 1); mutex_enter(&service_queue); RMQ(sq, sqhead, sqtail, sq_next, sq_chase, sq_curr, removed); mutex_exit(&service_queue); if (removed) { sq->sq_svcflags &= ~SQ_BGTHREAD; sq->sq_servcount = 0; STRSTAT(sqremoved); goto done; } } while (sq->sq_servcount != 0) { sq->sq_flags |= SQ_WANTWAKEUP; cv_wait(&sq->sq_wait, SQLOCK(sq)); } done: mutex_exit(SQLOCK(sq)); } /* * Put a syncq on the list of syncq's to be serviced by the sqthread. * Add the argument to the end of the sqhead list and set the flag * indicating this syncq has been enabled. If it has already been * enabled, don't do anything. * This routine assumes that SQLOCK is held. * NOTE that the lock order is to have the SQLOCK first, * so if the service_syncq lock is held, we need to release it * before aquiring the SQLOCK (mostly relevant for the background * thread, and this seems to be common among the STREAMS global locks). * Note the the sq_svcflags are protected by the SQLOCK. */ void sqenable(syncq_t *sq) { /* * This is probably not important except for where I believe it * is being called. At that point, it should be held (and it * is a pain to release it just for this routine, so don't do * it). */ ASSERT(MUTEX_HELD(SQLOCK(sq))); IMPLY(sq->sq_servcount == 0, sq->sq_next == NULL); IMPLY(sq->sq_next != NULL, sq->sq_svcflags & SQ_BGTHREAD); /* * Do not put on list if background thread is scheduled or * syncq is disabled. */ if (sq->sq_svcflags & (SQ_DISABLED | SQ_BGTHREAD)) return; /* * Check whether we should enable sq at all. * Non PERMOD syncqs may be drained by at most one thread. * PERMOD syncqs may be drained by several threads but we limit the * total amount to the lesser of * Number of queues on the squeue and * Number of CPUs. */ if (sq->sq_servcount != 0) { if (((sq->sq_type & SQ_PERMOD) == 0) || (sq->sq_servcount >= MIN(sq->sq_nqueues, ncpus_online))) { STRSTAT(sqtoomany); return; } } sq->sq_tstamp = lbolt; STRSTAT(sqenables); /* Attempt a taskq dispatch */ sq->sq_servid = (void *)taskq_dispatch(streams_taskq, (task_func_t *)syncq_service, sq, TQ_NOSLEEP | TQ_NOQUEUE); if (sq->sq_servid != NULL) { sq->sq_servcount++; return; } /* * This taskq dispatch failed, but a previous one may have succeeded. * Don't try to schedule on the background thread whilst there is * outstanding taskq processing. */ if (sq->sq_servcount != 0) return; /* * System is low on resources and can't perform a non-sleeping * dispatch. Schedule the syncq for a background thread and mark the * syncq to avoid any further taskq dispatch attempts. */ mutex_enter(&service_queue); STRSTAT(taskqfails); ENQUEUE(sq, sqhead, sqtail, sq_next); sq->sq_svcflags |= SQ_BGTHREAD; sq->sq_servcount = 1; cv_signal(&syncqs_to_run); mutex_exit(&service_queue); } /* * Note: fifo_close() depends on the mblk_t on the queue being freed * asynchronously. The asynchronous freeing of messages breaks the * recursive call chain of fifo_close() while there are I_SENDFD type of * messages refering other file pointers on the queue. Then when * closing pipes it can avoid stack overflow in case of daisy-chained * pipes, and also avoid deadlock in case of fifonode_t pairs (which * share the same fifolock_t). */ /* ARGSUSED */ void freebs_enqueue(mblk_t *mp, dblk_t *dbp) { ASSERT(dbp->db_mblk == mp); /* * Check data sanity. The dblock should have non-empty free function. * It is better to panic here then later when the dblock is freed * asynchronously when the context is lost. */ if (dbp->db_frtnp->free_func == NULL) { panic("freebs_enqueue: dblock %p has a NULL free callback", (void *) dbp); } STRSTAT(freebs); if (taskq_dispatch(streams_taskq, (task_func_t *)mblk_free, mp, TQ_NOSLEEP) == NULL) { /* * System is low on resources and can't perform a non-sleeping * dispatch. Schedule for a background thread. */ mutex_enter(&service_queue); STRSTAT(taskqfails); mp->b_next = freebs_list; freebs_list = mp; cv_signal(&services_to_run); mutex_exit(&service_queue); } } /* * Set the QBACK or QB_BACK flag in the given queue for * the given priority band. */ void setqback(queue_t *q, unsigned char pri) { int i; qband_t *qbp; qband_t **qbpp; ASSERT(MUTEX_HELD(QLOCK(q))); if (pri != 0) { if (pri > q->q_nband) { qbpp = &q->q_bandp; while (*qbpp) qbpp = &(*qbpp)->qb_next; while (pri > q->q_nband) { if ((*qbpp = allocband()) == NULL) { cmn_err(CE_WARN, "setqback: can't allocate qband\n"); return; } (*qbpp)->qb_hiwat = q->q_hiwat; (*qbpp)->qb_lowat = q->q_lowat; q->q_nband++; qbpp = &(*qbpp)->qb_next; } } qbp = q->q_bandp; i = pri; while (--i) qbp = qbp->qb_next; qbp->qb_flag |= QB_BACK; } else { q->q_flag |= QBACK; } } int strcopyin(void *from, void *to, size_t len, int copyflag) { if (copyflag & U_TO_K) { ASSERT((copyflag & K_TO_K) == 0); if (copyin(from, to, len)) return (EFAULT); } else { ASSERT(copyflag & K_TO_K); bcopy(from, to, len); } return (0); } int strcopyout(void *from, void *to, size_t len, int copyflag) { if (copyflag & U_TO_K) { if (copyout(from, to, len)) return (EFAULT); } else { ASSERT(copyflag & K_TO_K); bcopy(from, to, len); } return (0); } /* * strsignal_nolock() posts a signal to the process(es) at the stream head. * It assumes that the stream head lock is already held, whereas strsignal() * acquires the lock first. This routine was created because a few callers * release the stream head lock before calling only to re-acquire it after * it returns. */ void strsignal_nolock(stdata_t *stp, int sig, int32_t band) { ASSERT(MUTEX_HELD(&stp->sd_lock)); switch (sig) { case SIGPOLL: if (stp->sd_sigflags & S_MSG) strsendsig(stp->sd_siglist, S_MSG, (uchar_t)band, 0); break; default: if (stp->sd_pgidp) { pgsignal(stp->sd_pgidp, sig); } break; } } void strsignal(stdata_t *stp, int sig, int32_t band) { TRACE_3(TR_FAC_STREAMS_FR, TR_SENDSIG, "strsignal:%p, %X, %X", stp, sig, band); mutex_enter(&stp->sd_lock); switch (sig) { case SIGPOLL: if (stp->sd_sigflags & S_MSG) strsendsig(stp->sd_siglist, S_MSG, (uchar_t)band, 0); break; default: if (stp->sd_pgidp) { pgsignal(stp->sd_pgidp, sig); } break; } mutex_exit(&stp->sd_lock); } void strhup(stdata_t *stp) { pollwakeup(&stp->sd_pollist, POLLHUP); mutex_enter(&stp->sd_lock); if (stp->sd_sigflags & S_HANGUP) strsendsig(stp->sd_siglist, S_HANGUP, 0, 0); mutex_exit(&stp->sd_lock); } void stralloctty(stdata_t *stp) { proc_t *p = curproc; sess_t *sp = p->p_sessp; mutex_enter(&stp->sd_lock); /* * No need to hold the session lock or do a TTY_HOLD() because * this is the only thread that can be the session leader and not * have a controlling tty. */ if ((stp->sd_flag & (STRHUP|STRDERR|STWRERR|STPLEX|STRISTTY)) == STRISTTY && stp->sd_sidp == NULL && /* not allocated as ctty */ sp->s_sidp == p->p_pidp && /* session leader */ sp->s_flag != SESS_CLOSE && /* session is not closing */ sp->s_vp == NULL) { /* without ctty */ ASSERT(stp->sd_pgidp == NULL); alloctty(p, makectty(stp->sd_vnode)); mutex_enter(&pidlock); stp->sd_sidp = sp->s_sidp; stp->sd_pgidp = sp->s_sidp; PID_HOLD(stp->sd_pgidp); PID_HOLD(stp->sd_sidp); mutex_exit(&pidlock); } mutex_exit(&stp->sd_lock); } void strfreectty(stdata_t *stp) { mutex_enter(&stp->sd_lock); pgsignal(stp->sd_pgidp, SIGHUP); mutex_enter(&pidlock); PID_RELE(stp->sd_pgidp); PID_RELE(stp->sd_sidp); stp->sd_pgidp = NULL; stp->sd_sidp = NULL; mutex_exit(&pidlock); mutex_exit(&stp->sd_lock); if (!(stp->sd_flag & STRHUP)) strhup(stp); } /* * Backenable the first queue upstream from `q' with a service procedure. */ void backenable(queue_t *q, uchar_t pri) { queue_t *nq; /* * our presence might not prevent other modules in our own * stream from popping/pushing since the caller of getq might not * have a claim on the queue (some drivers do a getq on somebody * else's queue - they know that the queue itself is not going away * but the framework has to guarantee q_next in that stream.) */ claimstr(q); /* find nearest back queue with service proc */ for (nq = backq(q); nq && !nq->q_qinfo->qi_srvp; nq = backq(nq)) { ASSERT(STRMATED(q->q_stream) || STREAM(q) == STREAM(nq)); } if (nq) { kthread_t *freezer; /* * backenable can be called either with no locks held * or with the stream frozen (the latter occurs when a module * calls rmvq with the stream frozen.) If the stream is frozen * by the caller the caller will hold all qlocks in the stream. */ freezer = STREAM(q)->sd_freezer; if (freezer != curthread) { mutex_enter(QLOCK(nq)); } #ifdef DEBUG else { ASSERT(frozenstr(q)); ASSERT(MUTEX_HELD(QLOCK(q))); ASSERT(MUTEX_HELD(QLOCK(nq))); } #endif setqback(nq, pri); qenable_locked(nq); if (freezer != curthread) mutex_exit(QLOCK(nq)); } releasestr(q); } /* * Return the appropriate errno when one of flags_to_check is set * in sd_flags. Uses the exported error routines if they are set. * Will return 0 if non error is set (or if the exported error routines * do not return an error). * * If there is both a read and write error to check we prefer the read error. * Also, give preference to recorded errno's over the error functions. * The flags that are handled are: * STPLEX return EINVAL * STRDERR return sd_rerror (and clear if STRDERRNONPERSIST) * STWRERR return sd_werror (and clear if STWRERRNONPERSIST) * STRHUP return sd_werror * * If the caller indicates that the operation is a peek a nonpersistent error * is not cleared. */ int strgeterr(stdata_t *stp, int32_t flags_to_check, int ispeek) { int32_t sd_flag = stp->sd_flag & flags_to_check; int error = 0; ASSERT(MUTEX_HELD(&stp->sd_lock)); ASSERT((flags_to_check & ~(STRDERR|STWRERR|STRHUP|STPLEX)) == 0); if (sd_flag & STPLEX) error = EINVAL; else if (sd_flag & STRDERR) { error = stp->sd_rerror; if ((stp->sd_flag & STRDERRNONPERSIST) && !ispeek) { /* * Read errors are non-persistent i.e. discarded once * returned to a non-peeking caller, */ stp->sd_rerror = 0; stp->sd_flag &= ~STRDERR; } if (error == 0 && stp->sd_rderrfunc != NULL) { int clearerr = 0; error = (*stp->sd_rderrfunc)(stp->sd_vnode, ispeek, &clearerr); if (clearerr) { stp->sd_flag &= ~STRDERR; stp->sd_rderrfunc = NULL; } } } else if (sd_flag & STWRERR) { error = stp->sd_werror; if ((stp->sd_flag & STWRERRNONPERSIST) && !ispeek) { /* * Write errors are non-persistent i.e. discarded once * returned to a non-peeking caller, */ stp->sd_werror = 0; stp->sd_flag &= ~STWRERR; } if (error == 0 && stp->sd_wrerrfunc != NULL) { int clearerr = 0; error = (*stp->sd_wrerrfunc)(stp->sd_vnode, ispeek, &clearerr); if (clearerr) { stp->sd_flag &= ~STWRERR; stp->sd_wrerrfunc = NULL; } } } else if (sd_flag & STRHUP) { /* sd_werror set when STRHUP */ error = stp->sd_werror; } return (error); } /* * single-thread open/close/push/pop * for twisted streams also */ int strstartplumb(stdata_t *stp, int flag, int cmd) { int waited = 1; int error = 0; if (STRMATED(stp)) { struct stdata *stmatep = stp->sd_mate; STRLOCKMATES(stp); while (waited) { waited = 0; while (stmatep->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { if ((cmd == I_POP) && (flag & (FNDELAY|FNONBLOCK))) { STRUNLOCKMATES(stp); return (EAGAIN); } waited = 1; mutex_exit(&stp->sd_lock); if (!cv_wait_sig(&stmatep->sd_monitor, &stmatep->sd_lock)) { mutex_exit(&stmatep->sd_lock); return (EINTR); } mutex_exit(&stmatep->sd_lock); STRLOCKMATES(stp); } while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { if ((cmd == I_POP) && (flag & (FNDELAY|FNONBLOCK))) { STRUNLOCKMATES(stp); return (EAGAIN); } waited = 1; mutex_exit(&stmatep->sd_lock); if (!cv_wait_sig(&stp->sd_monitor, &stp->sd_lock)) { mutex_exit(&stp->sd_lock); return (EINTR); } mutex_exit(&stp->sd_lock); STRLOCKMATES(stp); } if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { error = strgeterr(stp, STRDERR|STWRERR|STRHUP|STPLEX, 0); if (error != 0) { STRUNLOCKMATES(stp); return (error); } } } stp->sd_flag |= STRPLUMB; STRUNLOCKMATES(stp); } else { mutex_enter(&stp->sd_lock); while (stp->sd_flag & (STWOPEN|STRCLOSE|STRPLUMB)) { if (((cmd == I_POP) || (cmd == _I_REMOVE)) && (flag & (FNDELAY|FNONBLOCK))) { mutex_exit(&stp->sd_lock); return (EAGAIN); } if (!cv_wait_sig(&stp->sd_monitor, &stp->sd_lock)) { mutex_exit(&stp->sd_lock); return (EINTR); } if (stp->sd_flag & (STRDERR|STWRERR|STRHUP|STPLEX)) { error = strgeterr(stp, STRDERR|STWRERR|STRHUP|STPLEX, 0); if (error != 0) { mutex_exit(&stp->sd_lock); return (error); } } } stp->sd_flag |= STRPLUMB; mutex_exit(&stp->sd_lock); } return (0); } /* * Complete the plumbing operation associated with stream `stp'. */ void strendplumb(stdata_t *stp) { ASSERT(MUTEX_HELD(&stp->sd_lock)); ASSERT(stp->sd_flag & STRPLUMB); stp->sd_flag &= ~STRPLUMB; cv_broadcast(&stp->sd_monitor); } /* * This describes how the STREAMS framework handles synchronization * during open/push and close/pop. * The key interfaces for open and close are qprocson and qprocsoff, * respectively. While the close case in general is harder both open * have close have significant similarities. * * During close the STREAMS framework has to both ensure that there * are no stale references to the queue pair (and syncq) that * are being closed and also provide the guarantees that are documented * in qprocsoff(9F). * If there are stale references to the queue that is closing it can * result in kernel memory corruption or kernel panics. * * Note that is it up to the module/driver to ensure that it itself * does not have any stale references to the closing queues once its close * routine returns. This includes: * - Cancelling any timeout/bufcall/qtimeout/qbufcall callback routines * associated with the queues. For timeout and bufcall callbacks the * module/driver also has to ensure (or wait for) any callbacks that * are in progress. * - If the module/driver is using esballoc it has to ensure that any * esballoc free functions do not refer to a queue that has closed. * (Note that in general the close routine can not wait for the esballoc'ed * messages to be freed since that can cause a deadlock.) * - Cancelling any interrupts that refer to the closing queues and * also ensuring that there are no interrupts in progress that will * refer to the closing queues once the close routine returns. * - For multiplexors removing any driver global state that refers to * the closing queue and also ensuring that there are no threads in * the multiplexor that has picked up a queue pointer but not yet * finished using it. * * In addition, a driver/module can only reference the q_next pointer * in its open, close, put, or service procedures or in a * qtimeout/qbufcall callback procedure executing "on" the correct * stream. Thus it can not reference the q_next pointer in an interrupt * routine or a timeout, bufcall or esballoc callback routine. Likewise * it can not reference q_next of a different queue e.g. in a mux that * passes messages from one queues put/service procedure to another queue. * In all the cases when the driver/module can not access the q_next * field it must use the *next* versions e.g. canputnext instead of * canput(q->q_next) and putnextctl instead of putctl(q->q_next, ...). * * * Assuming that the driver/module conforms to the above constraints * the STREAMS framework has to avoid stale references to q_next for all * the framework internal cases which include (but are not limited to): * - Threads in canput/canputnext/backenable and elsewhere that are * walking q_next. * - Messages on a syncq that have a reference to the queue through b_queue. * - Messages on an outer perimeter (syncq) that have a reference to the * queue through b_queue. * - Threads that use q_nfsrv (e.g. canput) to find a queue. * Note that only canput and bcanput use q_nfsrv without any locking. * * The STREAMS framework providing the qprocsoff(9F) guarantees means that * after qprocsoff returns, the framework has to ensure that no threads can * enter the put or service routines for the closing read or write-side queue. * In addition to preventing "direct" entry into the put procedures * the framework also has to prevent messages being drained from * the syncq or the outer perimeter. * XXX Note that currently qdetach does relies on D_MTOCEXCL as the only * mechanism to prevent qwriter(PERIM_OUTER) from running after * qprocsoff has returned. * Note that if a module/driver uses put(9F) on one of its own queues * it is up to the module/driver to ensure that the put() doesn't * get called when the queue is closing. * * * The framework aspects of the above "contract" is implemented by * qprocsoff, removeq, and strlock: * - qprocsoff (disable_svc) sets QWCLOSE to prevent runservice from * entering the service procedures. * - strlock acquires the sd_lock and sd_reflock to prevent putnext, * canputnext, backenable etc from dereferencing the q_next that will * soon change. * - strlock waits for sd_refcnt to be zero to wait for e.g. any canputnext * or other q_next walker that uses claimstr/releasestr to finish. * - optionally for every syncq in the stream strlock acquires all the * sq_lock's and waits for all sq_counts to drop to a value that indicates * that no thread executes in the put or service procedures and that no * thread is draining into the module/driver. This ensures that no * open, close, put, service, or qtimeout/qbufcall callback procedure is * currently executing hence no such thread can end up with the old stale * q_next value and no canput/backenable can have the old stale * q_nfsrv/q_next. * - qdetach (wait_svc) makes sure that any scheduled or running threads * have either finished or observed the QWCLOSE flag and gone away. */ /* * Get all the locks necessary to change q_next. * * Wait for sd_refcnt to reach 0 and, if sqlist is present, wait for the * sq_count of each syncq in the list to drop to sq_rmqcount, indicating that * the only threads inside the sqncq are threads currently calling removeq(). * Since threads calling removeq() are in the process of removing their queues * from the stream, we do not need to worry about them accessing a stale q_next * pointer and thus we do not need to wait for them to exit (in fact, waiting * for them can cause deadlock). * * This routine is subject to starvation since it does not set any flag to * prevent threads from entering a module in the stream(i.e. sq_count can * increase on some syncq while it is waiting on some other syncq.) * * Assumes that only one thread attempts to call strlock for a given * stream. If this is not the case the two threads would deadlock. * This assumption is guaranteed since strlock is only called by insertq * and removeq and streams plumbing changes are single-threaded for * a given stream using the STWOPEN, STRCLOSE, and STRPLUMB flags. * * For pipes, it is not difficult to atomically designate a pair of streams * to be mated. Once mated atomically by the framework the twisted pair remain * configured that way until dismantled atomically by the framework. * When plumbing takes place on a twisted stream it is necessary to ensure that * this operation is done exclusively on the twisted stream since two such * operations, each initiated on different ends of the pipe will deadlock * waiting for each other to complete. * * On entry, no locks should be held. * The locks acquired and held by strlock depends on a few factors. * - If sqlist is non-NULL all the syncq locks in the sqlist will be acquired * and held on exit and all sq_count are at an acceptable level. * - In all cases, sd_lock and sd_reflock are acquired and held on exit with * sd_refcnt being zero. */ static void strlock(struct stdata *stp, sqlist_t *sqlist) { syncql_t *sql, *sql2; retry: /* * Wait for any claimstr to go away. */ if (STRMATED(stp)) { struct stdata *stp1, *stp2; STRLOCKMATES(stp); /* * Note that the selection of locking order is not * important, just that they are always aquired in * the same order. To assure this, we choose this * order based on the value of the pointer, and since * the pointer will not change for the life of this * pair, we will always grab the locks in the same * order (and hence, prevent deadlocks). */ if (&(stp->sd_lock) > &((stp->sd_mate)->sd_lock)) { stp1 = stp; stp2 = stp->sd_mate; } else { stp2 = stp; stp1 = stp->sd_mate; } mutex_enter(&stp1->sd_reflock); if (stp1->sd_refcnt > 0) { STRUNLOCKMATES(stp); cv_wait(&stp1->sd_refmonitor, &stp1->sd_reflock); mutex_exit(&stp1->sd_reflock); goto retry; } mutex_enter(&stp2->sd_reflock); if (stp2->sd_refcnt > 0) { STRUNLOCKMATES(stp); mutex_exit(&stp1->sd_reflock); cv_wait(&stp2->sd_refmonitor, &stp2->sd_reflock); mutex_exit(&stp2->sd_reflock); goto retry; } STREAM_PUTLOCKS_ENTER(stp1); STREAM_PUTLOCKS_ENTER(stp2); } else { mutex_enter(&stp->sd_lock); mutex_enter(&stp->sd_reflock); while (stp->sd_refcnt > 0) { mutex_exit(&stp->sd_lock); cv_wait(&stp->sd_refmonitor, &stp->sd_reflock); if (mutex_tryenter(&stp->sd_lock) == 0) { mutex_exit(&stp->sd_reflock); mutex_enter(&stp->sd_lock); mutex_enter(&stp->sd_reflock); } } STREAM_PUTLOCKS_ENTER(stp); } if (sqlist == NULL) return; for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { syncq_t *sq = sql->sql_sq; uint16_t count; mutex_enter(SQLOCK(sq)); count = sq->sq_count; ASSERT(sq->sq_rmqcount <= count); SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); if (count == sq->sq_rmqcount) continue; /* Failed - drop all locks that we have acquired so far */ if (STRMATED(stp)) { STREAM_PUTLOCKS_EXIT(stp); STREAM_PUTLOCKS_EXIT(stp->sd_mate); STRUNLOCKMATES(stp); mutex_exit(&stp->sd_reflock); mutex_exit(&stp->sd_mate->sd_reflock); } else { STREAM_PUTLOCKS_EXIT(stp); mutex_exit(&stp->sd_lock); mutex_exit(&stp->sd_reflock); } for (sql2 = sqlist->sqlist_head; sql2 != sql; sql2 = sql2->sql_next) { SQ_PUTLOCKS_EXIT(sql2->sql_sq); mutex_exit(SQLOCK(sql2->sql_sq)); } /* * The wait loop below may starve when there are many threads * claiming the syncq. This is especially a problem with permod * syncqs (IP). To lessen the impact of the problem we increment * sq_needexcl and clear fastbits so that putnexts will slow * down and call sqenable instead of draining right away. */ sq->sq_needexcl++; SQ_PUTCOUNT_CLRFAST_LOCKED(sq); while (count > sq->sq_rmqcount) { sq->sq_flags |= SQ_WANTWAKEUP; SQ_PUTLOCKS_EXIT(sq); cv_wait(&sq->sq_wait, SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } sq->sq_needexcl--; if (sq->sq_needexcl == 0) SQ_PUTCOUNT_SETFAST_LOCKED(sq); SQ_PUTLOCKS_EXIT(sq); ASSERT(count == sq->sq_rmqcount); mutex_exit(SQLOCK(sq)); goto retry; } } /* * Drop all the locks that strlock acquired. */ static void strunlock(struct stdata *stp, sqlist_t *sqlist) { syncql_t *sql; if (STRMATED(stp)) { STREAM_PUTLOCKS_EXIT(stp); STREAM_PUTLOCKS_EXIT(stp->sd_mate); STRUNLOCKMATES(stp); mutex_exit(&stp->sd_reflock); mutex_exit(&stp->sd_mate->sd_reflock); } else { STREAM_PUTLOCKS_EXIT(stp); mutex_exit(&stp->sd_lock); mutex_exit(&stp->sd_reflock); } if (sqlist == NULL) return; for (sql = sqlist->sqlist_head; sql; sql = sql->sql_next) { SQ_PUTLOCKS_EXIT(sql->sql_sq); mutex_exit(SQLOCK(sql->sql_sq)); } } /* * When the module has service procedure, we need check if the next * module which has service procedure is in flow control to trigger * the backenable. */ static void backenable_insertedq(queue_t *q) { qband_t *qbp; claimstr(q); if (q->q_qinfo->qi_srvp != NULL && q->q_next != NULL) { if (q->q_next->q_nfsrv->q_flag & QWANTW) backenable(q, 0); qbp = q->q_next->q_nfsrv->q_bandp; for (; qbp != NULL; qbp = qbp->qb_next) if ((qbp->qb_flag & QB_WANTW) && qbp->qb_first != NULL) backenable(q, qbp->qb_first->b_band); } releasestr(q); } /* * Given two read queues, insert a new single one after another. * * This routine acquires all the necessary locks in order to change * q_next and related pointer using strlock(). * It depends on the stream head ensuring that there are no concurrent * insertq or removeq on the same stream. The stream head ensures this * using the flags STWOPEN, STRCLOSE, and STRPLUMB. * * Note that no syncq locks are held during the q_next change. This is * applied to all streams since, unlike removeq, there is no problem of stale * pointers when adding a module to the stream. Thus drivers/modules that do a * canput(rq->q_next) would never get a closed/freed queue pointer even if we * applied this optimization to all streams. */ void insertq(struct stdata *stp, queue_t *new) { queue_t *after; queue_t *wafter; queue_t *wnew = _WR(new); boolean_t have_fifo = B_FALSE; if (new->q_flag & _QINSERTING) { ASSERT(stp->sd_vnode->v_type != VFIFO); after = new->q_next; wafter = _WR(new->q_next); } else { after = _RD(stp->sd_wrq); wafter = stp->sd_wrq; } TRACE_2(TR_FAC_STREAMS_FR, TR_INSERTQ, "insertq:%p, %p", after, new); ASSERT(after->q_flag & QREADR); ASSERT(new->q_flag & QREADR); strlock(stp, NULL); /* Do we have a FIFO? */ if (wafter->q_next == after) { have_fifo = B_TRUE; wnew->q_next = new; } else { wnew->q_next = wafter->q_next; } new->q_next = after; set_nfsrv_ptr(new, wnew, after, wafter); /* * set_nfsrv_ptr() needs to know if this is an insertion or not, * so only reset this flag after calling it. */ new->q_flag &= ~_QINSERTING; if (have_fifo) { wafter->q_next = wnew; } else { if (wafter->q_next) _OTHERQ(wafter->q_next)->q_next = new; wafter->q_next = wnew; } set_qend(new); /* The QEND flag might have to be updated for the upstream guy */ set_qend(after); ASSERT(_SAMESTR(new) == O_SAMESTR(new)); ASSERT(_SAMESTR(wnew) == O_SAMESTR(wnew)); ASSERT(_SAMESTR(after) == O_SAMESTR(after)); ASSERT(_SAMESTR(wafter) == O_SAMESTR(wafter)); strsetuio(stp); /* * If this was a module insertion, bump the push count. */ if (!(new->q_flag & QISDRV)) stp->sd_pushcnt++; strunlock(stp, NULL); /* check if the write Q needs backenable */ backenable_insertedq(wnew); /* check if the read Q needs backenable */ backenable_insertedq(new); } /* * Given a read queue, unlink it from any neighbors. * * This routine acquires all the necessary locks in order to * change q_next and related pointers and also guard against * stale references (e.g. through q_next) to the queue that * is being removed. It also plays part of the role in ensuring * that the module's/driver's put procedure doesn't get called * after qprocsoff returns. * * Removeq depends on the stream head ensuring that there are * no concurrent insertq or removeq on the same stream. The * stream head ensures this using the flags STWOPEN, STRCLOSE and * STRPLUMB. * * The set of locks needed to remove the queue is different in * different cases: * * Acquire sd_lock, sd_reflock, and all the syncq locks in the stream after * waiting for the syncq reference count to drop to 0 indicating that no * non-close threads are present anywhere in the stream. This ensures that any * module/driver can reference q_next in its open, close, put, or service * procedures. * * The sq_rmqcount counter tracks the number of threads inside removeq(). * strlock() ensures that there is either no threads executing inside perimeter * or there is only a thread calling qprocsoff(). * * strlock() compares the value of sq_count with the number of threads inside * removeq() and waits until sq_count is equal to sq_rmqcount. We need to wakeup * any threads waiting in strlock() when the sq_rmqcount increases. */ void removeq(queue_t *qp) { queue_t *wqp = _WR(qp); struct stdata *stp = STREAM(qp); sqlist_t *sqlist = NULL; boolean_t isdriver; int moved; syncq_t *sq = qp->q_syncq; syncq_t *wsq = wqp->q_syncq; ASSERT(stp); TRACE_2(TR_FAC_STREAMS_FR, TR_REMOVEQ, "removeq:%p %p", qp, wqp); ASSERT(qp->q_flag&QREADR); /* * For queues using Synchronous streams, we must wait for all threads in * rwnext() to drain out before proceeding. */ if (qp->q_flag & QSYNCSTR) { /* First, we need wakeup any threads blocked in rwnext() */ mutex_enter(SQLOCK(sq)); if (sq->sq_flags & SQ_WANTWAKEUP) { sq->sq_flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } mutex_exit(SQLOCK(sq)); if (wsq != sq) { mutex_enter(SQLOCK(wsq)); if (wsq->sq_flags & SQ_WANTWAKEUP) { wsq->sq_flags &= ~SQ_WANTWAKEUP; cv_broadcast(&wsq->sq_wait); } mutex_exit(SQLOCK(wsq)); } mutex_enter(QLOCK(qp)); while (qp->q_rwcnt > 0) { qp->q_flag |= QWANTRMQSYNC; cv_wait(&qp->q_wait, QLOCK(qp)); } mutex_exit(QLOCK(qp)); mutex_enter(QLOCK(wqp)); while (wqp->q_rwcnt > 0) { wqp->q_flag |= QWANTRMQSYNC; cv_wait(&wqp->q_wait, QLOCK(wqp)); } mutex_exit(QLOCK(wqp)); } mutex_enter(SQLOCK(sq)); sq->sq_rmqcount++; if (sq->sq_flags & SQ_WANTWAKEUP) { sq->sq_flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } mutex_exit(SQLOCK(sq)); isdriver = (qp->q_flag & QISDRV); sqlist = sqlist_build(qp, stp, STRMATED(stp)); strlock(stp, sqlist); reset_nfsrv_ptr(qp, wqp); ASSERT(wqp->q_next == NULL || backq(qp)->q_next == qp); ASSERT(qp->q_next == NULL || backq(wqp)->q_next == wqp); /* Do we have a FIFO? */ if (wqp->q_next == qp) { stp->sd_wrq->q_next = _RD(stp->sd_wrq); } else { if (wqp->q_next) backq(qp)->q_next = qp->q_next; if (qp->q_next) backq(wqp)->q_next = wqp->q_next; } /* The QEND flag might have to be updated for the upstream guy */ if (qp->q_next) set_qend(qp->q_next); ASSERT(_SAMESTR(stp->sd_wrq) == O_SAMESTR(stp->sd_wrq)); ASSERT(_SAMESTR(_RD(stp->sd_wrq)) == O_SAMESTR(_RD(stp->sd_wrq))); /* * Move any messages destined for the put procedures to the next * syncq in line. Otherwise free them. */ moved = 0; /* * Quick check to see whether there are any messages or events. */ if (qp->q_syncqmsgs != 0 || (qp->q_syncq->sq_flags & SQ_EVENTS)) moved += propagate_syncq(qp); if (wqp->q_syncqmsgs != 0 || (wqp->q_syncq->sq_flags & SQ_EVENTS)) moved += propagate_syncq(wqp); strsetuio(stp); /* * If this was a module removal, decrement the push count. */ if (!isdriver) stp->sd_pushcnt--; strunlock(stp, sqlist); sqlist_free(sqlist); /* * Make sure any messages that were propagated are drained. * Also clear any QFULL bit caused by messages that were propagated. */ if (qp->q_next != NULL) { clr_qfull(qp); /* * For the driver calling qprocsoff, propagate_syncq * frees all the messages instead of putting it in * the stream head */ if (!isdriver && (moved > 0)) emptysq(qp->q_next->q_syncq); } if (wqp->q_next != NULL) { clr_qfull(wqp); /* * We come here for any pop of a module except for the * case of driver being removed. We don't call emptysq * if we did not move any messages. This will avoid holding * PERMOD syncq locks in emptysq */ if (moved > 0) emptysq(wqp->q_next->q_syncq); } mutex_enter(SQLOCK(sq)); sq->sq_rmqcount--; mutex_exit(SQLOCK(sq)); } /* * Prevent further entry by setting a flag (like SQ_FROZEN, SQ_BLOCKED or * SQ_WRITER) on a syncq. * If maxcnt is not -1 it assumes that caller has "maxcnt" claim(s) on the * sync queue and waits until sq_count reaches maxcnt. * * if maxcnt is -1 there's no need to grab sq_putlocks since the caller * does not care about putnext threads that are in the middle of calling put * entry points. * * This routine is used for both inner and outer syncqs. */ static void blocksq(syncq_t *sq, ushort_t flag, int maxcnt) { uint16_t count = 0; mutex_enter(SQLOCK(sq)); /* * Wait for SQ_FROZEN/SQ_BLOCKED to be reset. * SQ_FROZEN will be set if there is a frozen stream that has a * queue which also refers to this "shared" syncq. * SQ_BLOCKED will be set if there is "off" queue which also * refers to this "shared" syncq. */ if (maxcnt != -1) { count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SQ_PUTCOUNT_CLRFAST_LOCKED(sq); SUM_SQ_PUTCOUNTS(sq, count); } sq->sq_needexcl++; ASSERT(sq->sq_needexcl != 0); /* wraparound */ while ((sq->sq_flags & flag) || (maxcnt != -1 && count > (unsigned)maxcnt)) { sq->sq_flags |= SQ_WANTWAKEUP; if (maxcnt != -1) { SQ_PUTLOCKS_EXIT(sq); } cv_wait(&sq->sq_wait, SQLOCK(sq)); if (maxcnt != -1) { count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } } sq->sq_needexcl--; sq->sq_flags |= flag; ASSERT(maxcnt == -1 || count == maxcnt); if (maxcnt != -1) { if (sq->sq_needexcl == 0) { SQ_PUTCOUNT_SETFAST_LOCKED(sq); } SQ_PUTLOCKS_EXIT(sq); } else if (sq->sq_needexcl == 0) { SQ_PUTCOUNT_SETFAST(sq); } mutex_exit(SQLOCK(sq)); } /* * Reset a flag that was set with blocksq. * * Can not use this routine to reset SQ_WRITER. * * If "isouter" is set then the syncq is assumed to be an outer perimeter * and drain_syncq is not called. Instead we rely on the qwriter_outer thread * to handle the queued qwriter operations. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ static void unblocksq(syncq_t *sq, uint16_t resetflag, int isouter) { uint16_t flags; mutex_enter(SQLOCK(sq)); ASSERT(resetflag != SQ_WRITER); ASSERT(sq->sq_flags & resetflag); flags = sq->sq_flags & ~resetflag; sq->sq_flags = flags; if (flags & (SQ_QUEUED | SQ_WANTWAKEUP)) { if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } sq->sq_flags = flags; if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { if (!isouter) { /* drain_syncq drops SQLOCK */ drain_syncq(sq); return; } } } mutex_exit(SQLOCK(sq)); } /* * Reset a flag that was set with blocksq. * Does not drain the syncq. Use emptysq() for that. * Returns 1 if SQ_QUEUED is set. Otherwise 0. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ static int dropsq(syncq_t *sq, uint16_t resetflag) { uint16_t flags; mutex_enter(SQLOCK(sq)); ASSERT(sq->sq_flags & resetflag); flags = sq->sq_flags & ~resetflag; if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } sq->sq_flags = flags; mutex_exit(SQLOCK(sq)); if (flags & SQ_QUEUED) return (1); return (0); } /* * Empty all the messages on a syncq. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ static void emptysq(syncq_t *sq) { uint16_t flags; mutex_enter(SQLOCK(sq)); flags = sq->sq_flags; if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { /* * To prevent potential recursive invocation of drain_syncq we * do not call drain_syncq if count is non-zero. */ if (sq->sq_count == 0) { /* drain_syncq() drops SQLOCK */ drain_syncq(sq); return; } else sqenable(sq); } mutex_exit(SQLOCK(sq)); } /* * Ordered insert while removing duplicates. */ static void sqlist_insert(sqlist_t *sqlist, syncq_t *sqp) { syncql_t *sqlp, **prev_sqlpp, *new_sqlp; prev_sqlpp = &sqlist->sqlist_head; while ((sqlp = *prev_sqlpp) != NULL) { if (sqlp->sql_sq >= sqp) { if (sqlp->sql_sq == sqp) /* duplicate */ return; break; } prev_sqlpp = &sqlp->sql_next; } new_sqlp = &sqlist->sqlist_array[sqlist->sqlist_index++]; ASSERT((char *)new_sqlp < (char *)sqlist + sqlist->sqlist_size); new_sqlp->sql_next = sqlp; new_sqlp->sql_sq = sqp; *prev_sqlpp = new_sqlp; } /* * Walk the write side queues until we hit either the driver * or a twist in the stream (_SAMESTR will return false in both * these cases) then turn around and walk the read side queues * back up to the stream head. */ static void sqlist_insertall(sqlist_t *sqlist, queue_t *q) { while (q != NULL) { sqlist_insert(sqlist, q->q_syncq); if (_SAMESTR(q)) q = q->q_next; else if (!(q->q_flag & QREADR)) q = _RD(q); else q = NULL; } } /* * Allocate and build a list of all syncqs in a stream and the syncq(s) * associated with the "q" parameter. The resulting list is sorted in a * canonical order and is free of duplicates. * Assumes the passed queue is a _RD(q). */ static sqlist_t * sqlist_build(queue_t *q, struct stdata *stp, boolean_t do_twist) { sqlist_t *sqlist = sqlist_alloc(stp, KM_SLEEP); /* * start with the current queue/qpair */ ASSERT(q->q_flag & QREADR); sqlist_insert(sqlist, q->q_syncq); sqlist_insert(sqlist, _WR(q)->q_syncq); sqlist_insertall(sqlist, stp->sd_wrq); if (do_twist) sqlist_insertall(sqlist, stp->sd_mate->sd_wrq); return (sqlist); } static sqlist_t * sqlist_alloc(struct stdata *stp, int kmflag) { size_t sqlist_size; sqlist_t *sqlist; /* * Allocate 2 syncql_t's for each pushed module. Note that * the sqlist_t structure already has 4 syncql_t's built in: * 2 for the stream head, and 2 for the driver/other stream head. */ sqlist_size = 2 * sizeof (syncql_t) * stp->sd_pushcnt + sizeof (sqlist_t); if (STRMATED(stp)) sqlist_size += 2 * sizeof (syncql_t) * stp->sd_mate->sd_pushcnt; sqlist = kmem_alloc(sqlist_size, kmflag); sqlist->sqlist_head = NULL; sqlist->sqlist_size = sqlist_size; sqlist->sqlist_index = 0; return (sqlist); } /* * Free the list created by sqlist_alloc() */ static void sqlist_free(sqlist_t *sqlist) { kmem_free(sqlist, sqlist->sqlist_size); } /* * Prevent any new entries into any syncq in this stream. * Used by freezestr. */ void strblock(queue_t *q) { struct stdata *stp; syncql_t *sql; sqlist_t *sqlist; q = _RD(q); stp = STREAM(q); ASSERT(stp != NULL); /* * Get a sorted list with all the duplicates removed containing * all the syncqs referenced by this stream. */ sqlist = sqlist_build(q, stp, B_FALSE); for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) blocksq(sql->sql_sq, SQ_FROZEN, -1); sqlist_free(sqlist); } /* * Release the block on new entries into this stream */ void strunblock(queue_t *q) { struct stdata *stp; syncql_t *sql; sqlist_t *sqlist; int drain_needed; q = _RD(q); /* * Get a sorted list with all the duplicates removed containing * all the syncqs referenced by this stream. * Have to drop the SQ_FROZEN flag on all the syncqs before * starting to drain them; otherwise the draining might * cause a freezestr in some module on the stream (which * would deadlock.) */ stp = STREAM(q); ASSERT(stp != NULL); sqlist = sqlist_build(q, stp, B_FALSE); drain_needed = 0; for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) drain_needed += dropsq(sql->sql_sq, SQ_FROZEN); if (drain_needed) { for (sql = sqlist->sqlist_head; sql != NULL; sql = sql->sql_next) emptysq(sql->sql_sq); } sqlist_free(sqlist); } #ifdef DEBUG static int qprocsareon(queue_t *rq) { if (rq->q_next == NULL) return (0); return (_WR(rq->q_next)->q_next == _WR(rq)); } int qclaimed(queue_t *q) { uint_t count; count = q->q_syncq->sq_count; SUM_SQ_PUTCOUNTS(q->q_syncq, count); return (count != 0); } /* * Check if anyone has frozen this stream with freezestr */ int frozenstr(queue_t *q) { return ((q->q_syncq->sq_flags & SQ_FROZEN) != 0); } #endif /* DEBUG */ /* * Enter a queue. * Obsoleted interface. Should not be used. */ void enterq(queue_t *q) { entersq(q->q_syncq, SQ_CALLBACK); } void leaveq(queue_t *q) { leavesq(q->q_syncq, SQ_CALLBACK); } /* * Enter a perimeter. c_inner and c_outer specifies which concurrency bits * to check. * Wait if SQ_QUEUED is set to preserve ordering between messages and qwriter * calls and the running of open, close and service procedures. * * if c_inner bit is set no need to grab sq_putlocks since we don't care * if other threads have entered or are entering put entry point. * * if c_inner bit is set it might have been posible to use * sq_putlocks/sq_putcounts instead of SQLOCK/sq_count (e.g. to optimize * open/close path for IP) but since the count may need to be decremented in * qwait() we wouldn't know which counter to decrement. Currently counter is * selected by current cpu_seqid and current CPU can change at any moment. XXX * in the future we might use curthread id bits to select the counter and this * would stay constant across routine calls. */ void entersq(syncq_t *sq, int entrypoint) { uint16_t count = 0; uint16_t flags; uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; uint16_t type; uint_t c_inner = entrypoint & SQ_CI; uint_t c_outer = entrypoint & SQ_CO; /* * Increment ref count to keep closes out of this queue. */ ASSERT(sq); ASSERT(c_inner && c_outer); mutex_enter(SQLOCK(sq)); flags = sq->sq_flags; type = sq->sq_type; if (!(type & c_inner)) { /* Make sure all putcounts now use slowlock. */ count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SQ_PUTCOUNT_CLRFAST_LOCKED(sq); SUM_SQ_PUTCOUNTS(sq, count); sq->sq_needexcl++; ASSERT(sq->sq_needexcl != 0); /* wraparound */ waitflags |= SQ_MESSAGES; } /* * Wait until we can enter the inner perimeter. * If we want exclusive access we wait until sq_count is 0. * We have to do this before entering the outer perimeter in order * to preserve put/close message ordering. */ while ((flags & waitflags) || (!(type & c_inner) && count != 0)) { sq->sq_flags = flags | SQ_WANTWAKEUP; if (!(type & c_inner)) { SQ_PUTLOCKS_EXIT(sq); } cv_wait(&sq->sq_wait, SQLOCK(sq)); if (!(type & c_inner)) { count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } flags = sq->sq_flags; } if (!(type & c_inner)) { ASSERT(sq->sq_needexcl > 0); sq->sq_needexcl--; if (sq->sq_needexcl == 0) { SQ_PUTCOUNT_SETFAST_LOCKED(sq); } } /* Check if we need to enter the outer perimeter */ if (!(type & c_outer)) { /* * We have to enter the outer perimeter exclusively before * we can increment sq_count to avoid deadlock. This implies * that we have to re-check sq_flags and sq_count. * * is it possible to have c_inner set when c_outer is not set? */ if (!(type & c_inner)) { SQ_PUTLOCKS_EXIT(sq); } mutex_exit(SQLOCK(sq)); outer_enter(sq->sq_outer, SQ_GOAWAY); mutex_enter(SQLOCK(sq)); flags = sq->sq_flags; /* * there should be no need to recheck sq_putcounts * because outer_enter() has already waited for them to clear * after setting SQ_WRITER. */ count = sq->sq_count; #ifdef DEBUG /* * SUMCHECK_SQ_PUTCOUNTS should return the sum instead * of doing an ASSERT internally. Others should do * something like * ASSERT(SUMCHECK_SQ_PUTCOUNTS(sq) == 0); * without the need to #ifdef DEBUG it. */ SUMCHECK_SQ_PUTCOUNTS(sq, 0); #endif while ((flags & (SQ_EXCL|SQ_BLOCKED|SQ_FROZEN)) || (!(type & c_inner) && count != 0)) { sq->sq_flags = flags | SQ_WANTWAKEUP; cv_wait(&sq->sq_wait, SQLOCK(sq)); count = sq->sq_count; flags = sq->sq_flags; } } sq->sq_count++; ASSERT(sq->sq_count != 0); /* Wraparound */ if (!(type & c_inner)) { /* Exclusive entry */ ASSERT(sq->sq_count == 1); sq->sq_flags |= SQ_EXCL; if (type & c_outer) { SQ_PUTLOCKS_EXIT(sq); } } mutex_exit(SQLOCK(sq)); } /* * leave a syncq. announce to framework that closes may proceed. * c_inner and c_outer specifies which concurrency bits * to check. * * must never be called from driver or module put entry point. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ void leavesq(syncq_t *sq, int entrypoint) { uint16_t flags; uint16_t type; uint_t c_outer = entrypoint & SQ_CO; #ifdef DEBUG uint_t c_inner = entrypoint & SQ_CI; #endif /* * decrement ref count, drain the syncq if possible, and wake up * any waiting close. */ ASSERT(sq); ASSERT(c_inner && c_outer); mutex_enter(SQLOCK(sq)); flags = sq->sq_flags; type = sq->sq_type; if (flags & (SQ_QUEUED|SQ_WANTWAKEUP|SQ_WANTEXWAKEUP)) { if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } if (flags & SQ_WANTEXWAKEUP) { flags &= ~SQ_WANTEXWAKEUP; cv_broadcast(&sq->sq_exitwait); } if ((flags & SQ_QUEUED) && !(flags & SQ_STAYAWAY)) { /* * The syncq needs to be drained. "Exit" the syncq * before calling drain_syncq. */ ASSERT(sq->sq_count != 0); sq->sq_count--; ASSERT((flags & SQ_EXCL) || (type & c_inner)); sq->sq_flags = flags & ~SQ_EXCL; drain_syncq(sq); ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); /* Check if we need to exit the outer perimeter */ /* XXX will this ever be true? */ if (!(type & c_outer)) outer_exit(sq->sq_outer); return; } } ASSERT(sq->sq_count != 0); sq->sq_count--; ASSERT((flags & SQ_EXCL) || (type & c_inner)); sq->sq_flags = flags & ~SQ_EXCL; mutex_exit(SQLOCK(sq)); /* Check if we need to exit the outer perimeter */ if (!(sq->sq_type & c_outer)) outer_exit(sq->sq_outer); } /* * Prevent q_next from changing in this stream by incrementing sq_count. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ void claimq(queue_t *qp) { syncq_t *sq = qp->q_syncq; mutex_enter(SQLOCK(sq)); sq->sq_count++; ASSERT(sq->sq_count != 0); /* Wraparound */ mutex_exit(SQLOCK(sq)); } /* * Undo claimq. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. */ void releaseq(queue_t *qp) { syncq_t *sq = qp->q_syncq; uint16_t flags; mutex_enter(SQLOCK(sq)); ASSERT(sq->sq_count > 0); sq->sq_count--; flags = sq->sq_flags; if (flags & (SQ_WANTWAKEUP|SQ_QUEUED)) { if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } sq->sq_flags = flags; if ((flags & SQ_QUEUED) && !(flags & (SQ_STAYAWAY|SQ_EXCL))) { /* * To prevent potential recursive invocation of * drain_syncq we do not call drain_syncq if count is * non-zero. */ if (sq->sq_count == 0) { drain_syncq(sq); return; } else sqenable(sq); } } mutex_exit(SQLOCK(sq)); } /* * Prevent q_next from changing in this stream by incrementing sd_refcnt. */ void claimstr(queue_t *qp) { struct stdata *stp = STREAM(qp); mutex_enter(&stp->sd_reflock); stp->sd_refcnt++; ASSERT(stp->sd_refcnt != 0); /* Wraparound */ mutex_exit(&stp->sd_reflock); } /* * Undo claimstr. */ void releasestr(queue_t *qp) { struct stdata *stp = STREAM(qp); mutex_enter(&stp->sd_reflock); ASSERT(stp->sd_refcnt != 0); if (--stp->sd_refcnt == 0) cv_broadcast(&stp->sd_refmonitor); mutex_exit(&stp->sd_reflock); } static syncq_t * new_syncq(void) { return (kmem_cache_alloc(syncq_cache, KM_SLEEP)); } static void free_syncq(syncq_t *sq) { ASSERT(sq->sq_head == NULL); ASSERT(sq->sq_outer == NULL); ASSERT(sq->sq_callbpend == NULL); ASSERT((sq->sq_onext == NULL && sq->sq_oprev == NULL) || (sq->sq_onext == sq && sq->sq_oprev == sq)); if (sq->sq_ciputctrl != NULL) { ASSERT(sq->sq_nciputctrl == n_ciputctrl - 1); SUMCHECK_CIPUTCTRL_COUNTS(sq->sq_ciputctrl, sq->sq_nciputctrl, 0); ASSERT(ciputctrl_cache != NULL); kmem_cache_free(ciputctrl_cache, sq->sq_ciputctrl); } sq->sq_tail = NULL; sq->sq_evhead = NULL; sq->sq_evtail = NULL; sq->sq_ciputctrl = NULL; sq->sq_nciputctrl = 0; sq->sq_count = 0; sq->sq_rmqcount = 0; sq->sq_callbflags = 0; sq->sq_cancelid = 0; sq->sq_next = NULL; sq->sq_needexcl = 0; sq->sq_svcflags = 0; sq->sq_nqueues = 0; sq->sq_pri = 0; sq->sq_onext = NULL; sq->sq_oprev = NULL; sq->sq_flags = 0; sq->sq_type = 0; sq->sq_servcount = 0; kmem_cache_free(syncq_cache, sq); } /* Outer perimeter code */ /* * The outer syncq uses the fields and flags in the syncq slightly * differently from the inner syncqs. * sq_count Incremented when there are pending or running * writers at the outer perimeter to prevent the set of * inner syncqs that belong to the outer perimeter from * changing. * sq_head/tail List of deferred qwriter(OUTER) operations. * * SQ_BLOCKED Set to prevent traversing of sq_next,sq_prev while * inner syncqs are added to or removed from the * outer perimeter. * SQ_QUEUED sq_head/tail has messages or eventsqueued. * * SQ_WRITER A thread is currently traversing all the inner syncqs * setting the SQ_WRITER flag. */ /* * Get write access at the outer perimeter. * Note that read access is done by entersq, putnext, and put by simply * incrementing sq_count in the inner syncq. * * Waits until "flags" is no longer set in the outer to prevent multiple * threads from having write access at the same time. SQ_WRITER has to be part * of "flags". * * Increases sq_count on the outer syncq to keep away outer_insert/remove * until the outer_exit is finished. * * outer_enter is vulnerable to starvation since it does not prevent new * threads from entering the inner syncqs while it is waiting for sq_count to * go to zero. */ void outer_enter(syncq_t *outer, uint16_t flags) { syncq_t *sq; int wait_needed; uint16_t count; ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); ASSERT(flags & SQ_WRITER); retry: mutex_enter(SQLOCK(outer)); while (outer->sq_flags & flags) { outer->sq_flags |= SQ_WANTWAKEUP; cv_wait(&outer->sq_wait, SQLOCK(outer)); } ASSERT(!(outer->sq_flags & SQ_WRITER)); outer->sq_flags |= SQ_WRITER; outer->sq_count++; ASSERT(outer->sq_count != 0); /* wraparound */ wait_needed = 0; /* * Set SQ_WRITER on all the inner syncqs while holding * the SQLOCK on the outer syncq. This ensures that the changing * of SQ_WRITER is atomic under the outer SQLOCK. */ for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { mutex_enter(SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); sq->sq_flags |= SQ_WRITER; SUM_SQ_PUTCOUNTS(sq, count); if (count != 0) wait_needed = 1; SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); } mutex_exit(SQLOCK(outer)); /* * Get everybody out of the syncqs sequentially. * Note that we don't actually need to aqiure the PUTLOCKS, since * we have already cleared the fastbit, and set QWRITER. By * definition, the count can not increase since putnext will * take the slowlock path (and the purpose of aquiring the * putlocks was to make sure it didn't increase while we were * waiting). * * Note that we still aquire the PUTLOCKS to be safe. */ if (wait_needed) { for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { mutex_enter(SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); while (count != 0) { sq->sq_flags |= SQ_WANTWAKEUP; SQ_PUTLOCKS_EXIT(sq); cv_wait(&sq->sq_wait, SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); } /* * Verify that none of the flags got set while we * were waiting for the sq_counts to drop. * If this happens we exit and retry entering the * outer perimeter. */ mutex_enter(SQLOCK(outer)); if (outer->sq_flags & (flags & ~SQ_WRITER)) { mutex_exit(SQLOCK(outer)); outer_exit(outer); goto retry; } mutex_exit(SQLOCK(outer)); } } /* * Drop the write access at the outer perimeter. * Read access is dropped implicitly (by putnext, put, and leavesq) by * decrementing sq_count. */ void outer_exit(syncq_t *outer) { syncq_t *sq; int drain_needed; uint16_t flags; ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); ASSERT(MUTEX_NOT_HELD(SQLOCK(outer))); /* * Atomically (from the perspective of threads calling become_writer) * drop the write access at the outer perimeter by holding * SQLOCK(outer) across all the dropsq calls and the resetting of * SQ_WRITER. * This defines a locking order between the outer perimeter * SQLOCK and the inner perimeter SQLOCKs. */ mutex_enter(SQLOCK(outer)); flags = outer->sq_flags; ASSERT(outer->sq_flags & SQ_WRITER); if (flags & SQ_QUEUED) { write_now(outer); flags = outer->sq_flags; } /* * sq_onext is stable since sq_count has not yet been decreased. * Reset the SQ_WRITER flags in all syncqs. * After dropping SQ_WRITER on the outer syncq we empty all the * inner syncqs. */ drain_needed = 0; for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) drain_needed += dropsq(sq, SQ_WRITER); ASSERT(!(outer->sq_flags & SQ_QUEUED)); flags &= ~SQ_WRITER; if (drain_needed) { outer->sq_flags = flags; mutex_exit(SQLOCK(outer)); for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) emptysq(sq); mutex_enter(SQLOCK(outer)); flags = outer->sq_flags; } if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&outer->sq_wait); } outer->sq_flags = flags; ASSERT(outer->sq_count > 0); outer->sq_count--; mutex_exit(SQLOCK(outer)); } /* * Add another syncq to an outer perimeter. * Block out all other access to the outer perimeter while it is being * changed using blocksq. * Assumes that the caller has *not* done an outer_enter. * * Vulnerable to starvation in blocksq. */ static void outer_insert(syncq_t *outer, syncq_t *sq) { ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); ASSERT(sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL); /* Can't be in an outer perimeter */ /* Get exclusive access to the outer perimeter list */ blocksq(outer, SQ_BLOCKED, 0); ASSERT(outer->sq_flags & SQ_BLOCKED); ASSERT(!(outer->sq_flags & SQ_WRITER)); mutex_enter(SQLOCK(sq)); sq->sq_outer = outer; outer->sq_onext->sq_oprev = sq; sq->sq_onext = outer->sq_onext; outer->sq_onext = sq; sq->sq_oprev = outer; mutex_exit(SQLOCK(sq)); unblocksq(outer, SQ_BLOCKED, 1); } /* * Remove a syncq from an outer perimeter. * Block out all other access to the outer perimeter while it is being * changed using blocksq. * Assumes that the caller has *not* done an outer_enter. * * Vulnerable to starvation in blocksq. */ static void outer_remove(syncq_t *outer, syncq_t *sq) { ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); ASSERT(sq->sq_outer == outer); /* Get exclusive access to the outer perimeter list */ blocksq(outer, SQ_BLOCKED, 0); ASSERT(outer->sq_flags & SQ_BLOCKED); ASSERT(!(outer->sq_flags & SQ_WRITER)); mutex_enter(SQLOCK(sq)); sq->sq_outer = NULL; sq->sq_onext->sq_oprev = sq->sq_oprev; sq->sq_oprev->sq_onext = sq->sq_onext; sq->sq_oprev = sq->sq_onext = NULL; mutex_exit(SQLOCK(sq)); unblocksq(outer, SQ_BLOCKED, 1); } /* * Queue a deferred qwriter(OUTER) callback for this outer perimeter. * If this is the first callback for this outer perimeter then add * this outer perimeter to the list of outer perimeters that * the qwriter_outer_thread will process. * * Increments sq_count in the outer syncq to prevent the membership * of the outer perimeter (in terms of inner syncqs) to change while * the callback is pending. */ static void queue_writer(syncq_t *outer, void (*func)(), queue_t *q, mblk_t *mp) { ASSERT(MUTEX_HELD(SQLOCK(outer))); mp->b_prev = (mblk_t *)func; mp->b_queue = q; mp->b_next = NULL; outer->sq_count++; /* Decremented when dequeued */ ASSERT(outer->sq_count != 0); /* Wraparound */ if (outer->sq_evhead == NULL) { /* First message. */ outer->sq_evhead = outer->sq_evtail = mp; outer->sq_flags |= SQ_EVENTS; mutex_exit(SQLOCK(outer)); STRSTAT(qwr_outer); (void) taskq_dispatch(streams_taskq, (task_func_t *)qwriter_outer_service, outer, TQ_SLEEP); } else { ASSERT(outer->sq_flags & SQ_EVENTS); outer->sq_evtail->b_next = mp; outer->sq_evtail = mp; mutex_exit(SQLOCK(outer)); } } /* * Try and upgrade to write access at the outer perimeter. If this can * not be done without blocking then queue the callback to be done * by the qwriter_outer_thread. * * This routine can only be called from put or service procedures plus * asynchronous callback routines that have properly entered to * queue (with entersq.) Thus qwriter(OUTER) assumes the caller has one claim * on the syncq associated with q. */ void qwriter_outer(queue_t *q, mblk_t *mp, void (*func)()) { syncq_t *osq, *sq, *outer; int failed; uint16_t flags; osq = q->q_syncq; outer = osq->sq_outer; if (outer == NULL) panic("qwriter(PERIM_OUTER): no outer perimeter"); ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); mutex_enter(SQLOCK(outer)); flags = outer->sq_flags; /* * If some thread is traversing sq_next, or if we are blocked by * outer_insert or outer_remove, or if the we already have queued * callbacks, then queue this callback for later processing. * * Also queue the qwriter for an interrupt thread in order * to reduce the time spent running at high IPL. * to identify there are events. */ if ((flags & SQ_GOAWAY) || (curthread->t_pri >= kpreemptpri)) { /* * Queue the become_writer request. * The queueing is atomic under SQLOCK(outer) in order * to synchronize with outer_exit. * queue_writer will drop the outer SQLOCK */ if (flags & SQ_BLOCKED) { /* Must set SQ_WRITER on inner perimeter */ mutex_enter(SQLOCK(osq)); osq->sq_flags |= SQ_WRITER; mutex_exit(SQLOCK(osq)); } else { if (!(flags & SQ_WRITER)) { /* * The outer could have been SQ_BLOCKED thus * SQ_WRITER might not be set on the inner. */ mutex_enter(SQLOCK(osq)); osq->sq_flags |= SQ_WRITER; mutex_exit(SQLOCK(osq)); } ASSERT(osq->sq_flags & SQ_WRITER); } queue_writer(outer, func, q, mp); return; } /* * We are half-way to exclusive access to the outer perimeter. * Prevent any outer_enter, qwriter(OUTER), or outer_insert/remove * while the inner syncqs are traversed. */ outer->sq_count++; ASSERT(outer->sq_count != 0); /* wraparound */ flags |= SQ_WRITER; /* * Check if we can run the function immediately. Mark all * syncqs with the writer flag to prevent new entries into * put and service procedures. * * Set SQ_WRITER on all the inner syncqs while holding * the SQLOCK on the outer syncq. This ensures that the changing * of SQ_WRITER is atomic under the outer SQLOCK. */ failed = 0; for (sq = outer->sq_onext; sq != outer; sq = sq->sq_onext) { uint16_t count; uint_t maxcnt = (sq == osq) ? 1 : 0; mutex_enter(SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); if (sq->sq_count > maxcnt) failed = 1; sq->sq_flags |= SQ_WRITER; SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); } if (failed) { /* * Some other thread has a read claim on the outer perimeter. * Queue the callback for deferred processing. * * queue_writer will set SQ_QUEUED before we drop SQ_WRITER * so that other qwriter(OUTER) calls will queue their * callbacks as well. queue_writer increments sq_count so we * decrement to compensate for the our increment. * * Dropping SQ_WRITER enables the writer thread to work * on this outer perimeter. */ outer->sq_flags = flags; queue_writer(outer, func, q, mp); /* queue_writer dropper the lock */ mutex_enter(SQLOCK(outer)); ASSERT(outer->sq_count > 0); outer->sq_count--; ASSERT(outer->sq_flags & SQ_WRITER); flags = outer->sq_flags; flags &= ~SQ_WRITER; if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&outer->sq_wait); } outer->sq_flags = flags; mutex_exit(SQLOCK(outer)); return; } else { outer->sq_flags = flags; mutex_exit(SQLOCK(outer)); } /* Can run it immediately */ (*func)(q, mp); outer_exit(outer); } /* * Dequeue all writer callbacks from the outer perimeter and run them. */ static void write_now(syncq_t *outer) { mblk_t *mp; queue_t *q; void (*func)(); ASSERT(MUTEX_HELD(SQLOCK(outer))); ASSERT(outer->sq_outer == NULL && outer->sq_onext != NULL && outer->sq_oprev != NULL); while ((mp = outer->sq_evhead) != NULL) { /* * queues cannot be placed on the queuelist on the outer * perimiter. */ ASSERT(!(outer->sq_flags & SQ_MESSAGES)); ASSERT((outer->sq_flags & SQ_EVENTS)); outer->sq_evhead = mp->b_next; if (outer->sq_evhead == NULL) { outer->sq_evtail = NULL; outer->sq_flags &= ~SQ_EVENTS; } ASSERT(outer->sq_count != 0); outer->sq_count--; /* Incremented when enqueued. */ mutex_exit(SQLOCK(outer)); /* * Drop the message if the queue is closing. * Make sure that the queue is "claimed" when the callback * is run in order to satisfy various ASSERTs. */ q = mp->b_queue; func = (void (*)())mp->b_prev; ASSERT(func != NULL); mp->b_next = mp->b_prev = NULL; if (q->q_flag & QWCLOSE) { freemsg(mp); } else { claimq(q); (*func)(q, mp); releaseq(q); } mutex_enter(SQLOCK(outer)); } ASSERT(MUTEX_HELD(SQLOCK(outer))); } /* * The list of messages on the inner syncq is effectively hashed * by destination queue. These destination queues are doubly * linked lists (hopefully) in priority order. Messages are then * put on the queue referenced by the q_sqhead/q_sqtail elements. * Additional messages are linked together by the b_next/b_prev * elements in the mblk, with (similar to putq()) the first message * having a NULL b_prev and the last message having a NULL b_next. * * Events, such as qwriter callbacks, are put onto a list in FIFO * order referenced by sq_evhead, and sq_evtail. This is a singly * linked list, and messages here MUST be processed in the order queued. */ /* * Run the events on the syncq event list (sq_evhead). * Assumes there is only one claim on the syncq, it is * already exclusive (SQ_EXCL set), and the SQLOCK held. * Messages here are processed in order, with the SQ_EXCL bit * held all the way through till the last message is processed. */ void sq_run_events(syncq_t *sq) { mblk_t *bp; queue_t *qp; uint16_t flags = sq->sq_flags; void (*func)(); ASSERT(MUTEX_HELD(SQLOCK(sq))); ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL) || (sq->sq_outer != NULL && sq->sq_onext != NULL && sq->sq_oprev != NULL)); ASSERT(flags & SQ_EXCL); ASSERT(sq->sq_count == 1); /* * We need to process all of the events on this list. It * is possible that new events will be added while we are * away processing a callback, so on every loop, we start * back at the beginning of the list. */ /* * We have to reaccess sq_evhead since there is a * possibility of a new entry while we were running * the callback. */ for (bp = sq->sq_evhead; bp != NULL; bp = sq->sq_evhead) { ASSERT(bp->b_queue->q_syncq == sq); ASSERT(sq->sq_flags & SQ_EVENTS); qp = bp->b_queue; func = (void (*)())bp->b_prev; ASSERT(func != NULL); /* * Messages from the event queue must be taken off in * FIFO order. */ ASSERT(sq->sq_evhead == bp); sq->sq_evhead = bp->b_next; if (bp->b_next == NULL) { /* Deleting last */ ASSERT(sq->sq_evtail == bp); sq->sq_evtail = NULL; sq->sq_flags &= ~SQ_EVENTS; } bp->b_prev = bp->b_next = NULL; ASSERT(bp->b_datap->db_ref != 0); mutex_exit(SQLOCK(sq)); (*func)(qp, bp); mutex_enter(SQLOCK(sq)); /* * re-read the flags, since they could have changed. */ flags = sq->sq_flags; ASSERT(flags & SQ_EXCL); } ASSERT(sq->sq_evhead == NULL && sq->sq_evtail == NULL); ASSERT(!(sq->sq_flags & SQ_EVENTS)); if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } if (flags & SQ_WANTEXWAKEUP) { flags &= ~SQ_WANTEXWAKEUP; cv_broadcast(&sq->sq_exitwait); } sq->sq_flags = flags; } /* * Put messages on the event list. * If we can go exclusive now, do so and process the event list, otherwise * let the last claim service this list (or wake the sqthread). * This procedure assumes SQLOCK is held. To run the event list, it * must be called with no claims. */ static void sqfill_events(syncq_t *sq, queue_t *q, mblk_t *mp, void (*func)()) { uint16_t count; ASSERT(MUTEX_HELD(SQLOCK(sq))); ASSERT(func != NULL); /* * This is a callback. Add it to the list of callbacks * and see about upgrading. */ mp->b_prev = (mblk_t *)func; mp->b_queue = q; mp->b_next = NULL; if (sq->sq_evhead == NULL) { sq->sq_evhead = sq->sq_evtail = mp; sq->sq_flags |= SQ_EVENTS; } else { ASSERT(sq->sq_evtail != NULL); ASSERT(sq->sq_evtail->b_next == NULL); ASSERT(sq->sq_flags & SQ_EVENTS); sq->sq_evtail->b_next = mp; sq->sq_evtail = mp; } /* * We have set SQ_EVENTS, so threads will have to * unwind out of the perimiter, and new entries will * not grab a putlock. But we still need to know * how many threads have already made a claim to the * syncq, so grab the putlocks, and sum the counts. * If there are no claims on the syncq, we can upgrade * to exclusive, and run the event list. * NOTE: We hold the SQLOCK, so we can just grab the * putlocks. */ count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); /* * We have no claim, so we need to check if there * are no others, then we can upgrade. */ /* * There are currently no claims on * the syncq by this thread (at least on this entry). The thread who has * the claim should drain syncq. */ if (count > 0) { /* * Can't upgrade - other threads inside. */ SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); return; } /* * Need to set SQ_EXCL and make a claim on the syncq. */ ASSERT((sq->sq_flags & SQ_EXCL) == 0); sq->sq_flags |= SQ_EXCL; ASSERT(sq->sq_count == 0); sq->sq_count++; SQ_PUTLOCKS_EXIT(sq); /* Process the events list */ sq_run_events(sq); /* * Release our claim... */ sq->sq_count--; /* * And release SQ_EXCL. * We don't need to acquire the putlocks to release * SQ_EXCL, since we are exclusive, and hold the SQLOCK. */ sq->sq_flags &= ~SQ_EXCL; /* * sq_run_events should have released SQ_EXCL */ ASSERT(!(sq->sq_flags & SQ_EXCL)); /* * If anything happened while we were running the * events (or was there before), we need to process * them now. We shouldn't be exclusive sine we * released the perimiter above (plus, we asserted * for it). */ if (!(sq->sq_flags & SQ_STAYAWAY) && (sq->sq_flags & SQ_QUEUED)) drain_syncq(sq); else mutex_exit(SQLOCK(sq)); } /* * Perform delayed processing. The caller has to make sure that it is safe * to enter the syncq (e.g. by checking that none of the SQ_STAYAWAY bits are * set.) * * Assume that the caller has NO claims on the syncq. However, a claim * on the syncq does not indicate that a thread is draining the syncq. * There may be more claims on the syncq than there are threads draining * (i.e. #_threads_draining <= sq_count) * * drain_syncq has to terminate when one of the SQ_STAYAWAY bits gets set * in order to preserve qwriter(OUTER) ordering constraints. * * sq_putcount only needs to be checked when dispatching the queued * writer call for CIPUT sync queue, but this is handled in sq_run_events. */ void drain_syncq(syncq_t *sq) { queue_t *qp; uint16_t count; uint16_t type = sq->sq_type; uint16_t flags = sq->sq_flags; boolean_t bg_service = sq->sq_svcflags & SQ_SERVICE; TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, "drain_syncq start:%p", sq); ASSERT(MUTEX_HELD(SQLOCK(sq))); ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL) || (sq->sq_outer != NULL && sq->sq_onext != NULL && sq->sq_oprev != NULL)); /* * Drop SQ_SERVICE flag. */ if (bg_service) sq->sq_svcflags &= ~SQ_SERVICE; /* * If SQ_EXCL is set, someone else is processing this syncq - let him * finish the job. */ if (flags & SQ_EXCL) { if (bg_service) { ASSERT(sq->sq_servcount != 0); sq->sq_servcount--; } mutex_exit(SQLOCK(sq)); return; } /* * This routine can be called by a background thread if * it was scheduled by a hi-priority thread. SO, if there are * NOT messages queued, return (remember, we have the SQLOCK, * and it cannot change until we release it). Wakeup any waiters also. */ if (!(flags & SQ_QUEUED)) { if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } if (flags & SQ_WANTEXWAKEUP) { flags &= ~SQ_WANTEXWAKEUP; cv_broadcast(&sq->sq_exitwait); } sq->sq_flags = flags; if (bg_service) { ASSERT(sq->sq_servcount != 0); sq->sq_servcount--; } mutex_exit(SQLOCK(sq)); return; } /* * If this is not a concurrent put perimiter, we need to * become exclusive to drain. Also, if not CIPUT, we would * not have acquired a putlock, so we don't need to check * the putcounts. If not entering with a claim, we test * for sq_count == 0. */ type = sq->sq_type; if (!(type & SQ_CIPUT)) { if (sq->sq_count > 1) { if (bg_service) { ASSERT(sq->sq_servcount != 0); sq->sq_servcount--; } mutex_exit(SQLOCK(sq)); return; } sq->sq_flags |= SQ_EXCL; } /* * This is where we make a claim to the syncq. * This can either be done by incrementing a putlock, or * the sq_count. But since we already have the SQLOCK * here, we just bump the sq_count. * * Note that after we make a claim, we need to let the code * fall through to the end of this routine to clean itself * up. A return in the while loop will put the syncq in a * very bad state. */ sq->sq_count++; ASSERT(sq->sq_count != 0); /* wraparound */ while ((flags = sq->sq_flags) & SQ_QUEUED) { /* * If we are told to stayaway or went exclusive, * we are done. */ if (flags & (SQ_STAYAWAY)) { break; } /* * If there are events to run, do so. * We have one claim to the syncq, so if there are * more than one, other threads are running. */ if (sq->sq_evhead != NULL) { ASSERT(sq->sq_flags & SQ_EVENTS); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); if (count > 1) { SQ_PUTLOCKS_EXIT(sq); /* Can't upgrade - other threads inside */ break; } ASSERT((flags & SQ_EXCL) == 0); sq->sq_flags = flags | SQ_EXCL; SQ_PUTLOCKS_EXIT(sq); /* * we have the only claim, run the events, * sq_run_events will clear the SQ_EXCL flag. */ sq_run_events(sq); /* * If this is a CIPUT perimiter, we need * to drop the SQ_EXCL flag so we can properly * continue draining the syncq. */ if (type & SQ_CIPUT) { ASSERT(sq->sq_flags & SQ_EXCL); sq->sq_flags &= ~SQ_EXCL; } /* * And go back to the beginning just in case * anything changed while we were away. */ ASSERT((sq->sq_flags & SQ_EXCL) || (type & SQ_CIPUT)); continue; } ASSERT(sq->sq_evhead == NULL); ASSERT(!(sq->sq_flags & SQ_EVENTS)); /* * Find the queue that is not draining. * * q_draining is protected by QLOCK which we do not hold. * But if it was set, then a thread was draining, and if it gets * cleared, then it was because the thread has successfully * drained the syncq, or a GOAWAY state occured. For the GOAWAY * state to happen, a thread needs the SQLOCK which we hold, and * if there was such a flag, we whould have already seen it. */ for (qp = sq->sq_head; qp != NULL && (qp->q_draining || (qp->q_sqflags & Q_SQDRAINING)); qp = qp->q_sqnext) ; if (qp == NULL) break; /* * We have a queue to work on, and we hold the * SQLOCK and one claim, call qdrain_syncq. * This means we need to release the SQLOCK and * aquire the QLOCK (OK since we have a claim). * Note that qdrain_syncq will actually dequeue * this queue from the sq_head list when it is * convinced all the work is done and release * the QLOCK before returning. */ qp->q_sqflags |= Q_SQDRAINING; mutex_exit(SQLOCK(sq)); mutex_enter(QLOCK(qp)); qdrain_syncq(sq, qp); mutex_enter(SQLOCK(sq)); /* The queue is drained */ ASSERT(qp->q_sqflags & Q_SQDRAINING); qp->q_sqflags &= ~Q_SQDRAINING; /* * NOTE: After this point qp should not be used since it may be * closed. */ } ASSERT(MUTEX_HELD(SQLOCK(sq))); flags = sq->sq_flags; /* * sq->sq_head cannot change because we hold the * sqlock. However, a thread CAN decide that it is no longer * going to drain that queue. However, this should be due to * a GOAWAY state, and we should see that here. * * This loop is not very efficient. One solution may be adding a second * pointer to the "draining" queue, but it is difficult to do when * queues are inserted in the middle due to priority ordering. Another * possibility is to yank the queue out of the sq list and put it onto * the "draining list" and then put it back if it can't be drained. */ ASSERT((sq->sq_head == NULL) || (flags & SQ_GOAWAY) || (type & SQ_CI) || sq->sq_head->q_draining); /* Drop SQ_EXCL for non-CIPUT perimiters */ if (!(type & SQ_CIPUT)) flags &= ~SQ_EXCL; ASSERT((flags & SQ_EXCL) == 0); /* Wake up any waiters. */ if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } if (flags & SQ_WANTEXWAKEUP) { flags &= ~SQ_WANTEXWAKEUP; cv_broadcast(&sq->sq_exitwait); } sq->sq_flags = flags; ASSERT(sq->sq_count != 0); /* Release our claim. */ sq->sq_count--; if (bg_service) { ASSERT(sq->sq_servcount != 0); sq->sq_servcount--; } mutex_exit(SQLOCK(sq)); TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, "drain_syncq end:%p", sq); } /* * * qdrain_syncq can be called (currently) from only one of two places: * drain_syncq * putnext (or some variation of it). * and eventually * qwait(_sig) * * If called from drain_syncq, we found it in the list * of queue's needing service, so there is work to be done (or it * wouldn't be on the list). * * If called from some putnext variation, it was because the * perimiter is open, but messages are blocking a putnext and * there is not a thread working on it. Now a thread could start * working on it while we are getting ready to do so ourself, but * the thread would set the q_draining flag, and we can spin out. * * As for qwait(_sig), I think I shall let it continue to call * drain_syncq directly (after all, it will get here eventually). * * qdrain_syncq has to terminate when: * - one of the SQ_STAYAWAY bits gets set to preserve qwriter(OUTER) ordering * - SQ_EVENTS gets set to preserve qwriter(INNER) ordering * * ASSUMES: * One claim * QLOCK held * SQLOCK not held * Will release QLOCK before returning */ void qdrain_syncq(syncq_t *sq, queue_t *q) { mblk_t *bp; boolean_t do_clr; #ifdef DEBUG uint16_t count; #endif TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_START, "drain_syncq start:%p", sq); ASSERT(q->q_syncq == sq); ASSERT(MUTEX_HELD(QLOCK(q))); ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); /* * For non-CIPUT perimiters, we should be called with the * exclusive bit set already. For non-CIPUT perimiters we * will be doing a concurrent drain, so it better not be set. */ ASSERT((sq->sq_flags & (SQ_EXCL|SQ_CIPUT))); ASSERT(!((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL))); ASSERT((sq->sq_type & SQ_CIPUT) || (sq->sq_flags & SQ_EXCL)); /* * All outer pointers are set, or none of them are */ ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL) || (sq->sq_outer != NULL && sq->sq_onext != NULL && sq->sq_oprev != NULL)); #ifdef DEBUG count = sq->sq_count; /* * This is OK without the putlocks, because we have one * claim either from the sq_count, or a putcount. We could * get an erroneous value from other counts, but ours won't * change, so one way or another, we will have at least a * value of one. */ SUM_SQ_PUTCOUNTS(sq, count); ASSERT(count >= 1); #endif /* DEBUG */ /* * The first thing to do here, is find out if a thread is already * draining this queue or the queue is closing. If so, we are done, * just return. Also, if there are no messages, we are done as well. * Note that we check the q_sqhead since there is s window of * opportunity for us to enter here because Q_SQQUEUED was set, but is * not anymore. */ if (q->q_draining || (q->q_sqhead == NULL)) { mutex_exit(QLOCK(q)); return; } /* * If the perimiter is exclusive, there is nothing we can * do right now, go away. * Note that there is nothing to prevent this case from changing * right after this check, but the spin-out will catch it. */ /* Tell other threads that we are draining this queue */ q->q_draining = 1; /* Protected by QLOCK */ for (bp = q->q_sqhead; bp != NULL; bp = q->q_sqhead) { /* * Because we can enter this routine just because * a putnext is blocked, we need to spin out if * the perimiter wants to go exclusive as well * as just blocked. We need to spin out also if * events are queued on the syncq. * Don't check for SQ_EXCL, because non-CIPUT * perimiters would set it, and it can't become * exclusive while we hold a claim. */ if (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS)) { break; } #ifdef DEBUG /* * Since we are in qdrain_syncq, we already know the queue, * but for sanity, we want to check this against the qp that * was passed in by bp->b_queue. */ ASSERT(bp->b_queue == q); ASSERT(bp->b_queue->q_syncq == sq); bp->b_queue = NULL; /* * We would have the following check in the DEBUG code: * * if (bp->b_prev != NULL) { * ASSERT(bp->b_prev == (void (*)())q->q_qinfo->qi_putp); * } * * This can't be done, however, since IP modifies qinfo * structure at run-time (switching between IPv4 qinfo and IPv6 * qinfo), invalidating the check. * So the assignment to func is left here, but the ASSERT itself * is removed until the whole issue is resolved. */ #endif ASSERT(q->q_sqhead == bp); q->q_sqhead = bp->b_next; bp->b_prev = bp->b_next = NULL; ASSERT(q->q_syncqmsgs > 0); mutex_exit(QLOCK(q)); ASSERT(bp->b_datap->db_ref != 0); (void) (*q->q_qinfo->qi_putp)(q, bp); mutex_enter(QLOCK(q)); /* * We should decrement q_syncqmsgs only after executing the * put procedure to avoid a possible race with putnext(). * In putnext() though it sees Q_SQQUEUED is set, there is * an optimization which allows putnext to call the put * procedure directly if (q_syncqmsgs == 0) and thus * a message reodering could otherwise occur. */ q->q_syncqmsgs--; /* * Clear QFULL in the next service procedure queue if * this is the last message destined to that queue. * * It would make better sense to have some sort of * tunable for the low water mark, but these symantics * are not yet defined. So, alas, we use a constant. */ do_clr = (q->q_syncqmsgs == 0); mutex_exit(QLOCK(q)); if (do_clr) clr_qfull(q); mutex_enter(QLOCK(q)); /* * Always clear SQ_EXCL when CIPUT in order to handle * qwriter(INNER). */ /* * The putp() can call qwriter and get exclusive access * IFF this is the only claim. So, we need to test for * this possibility so we can aquire the mutex and clear * the bit. */ if ((sq->sq_type & SQ_CIPUT) && (sq->sq_flags & SQ_EXCL)) { mutex_enter(SQLOCK(sq)); sq->sq_flags &= ~SQ_EXCL; mutex_exit(SQLOCK(sq)); } } /* * We should either have no queues on the syncq, or we were * told to goaway by a waiter (which we will wake up at the * end of this function). */ ASSERT((q->q_sqhead == NULL) || (sq->sq_flags & (SQ_STAYAWAY | SQ_EVENTS))); ASSERT(MUTEX_HELD(QLOCK(q))); ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); /* * Remove the q from the syncq list if all the messages are * drained. */ if (q->q_sqhead == NULL) { mutex_enter(SQLOCK(sq)); if (q->q_sqflags & Q_SQQUEUED) SQRM_Q(sq, q); mutex_exit(SQLOCK(sq)); /* * Since the queue is removed from the list, reset its priority. */ q->q_spri = 0; } /* * Remember, the q_draining flag is used to let another * thread know that there is a thread currently draining * the messages for a queue. Since we are now done with * this queue (even if there may be messages still there), * we need to clear this flag so some thread will work * on it if needed. */ ASSERT(q->q_draining); q->q_draining = 0; /* called with a claim, so OK to drop all locks. */ mutex_exit(QLOCK(q)); TRACE_1(TR_FAC_STREAMS_FR, TR_DRAIN_SYNCQ_END, "drain_syncq end:%p", sq); } /* END OF QDRAIN_SYNCQ */ /* * This is the mate to qdrain_syncq, except that it is putting the * message onto the the queue instead draining. Since the * message is destined for the queue that is selected, there is * no need to identify the function because the message is * intended for the put routine for the queue. But this * routine will do it anyway just in case (but only for debug kernels). * * After the message is enqueued on the syncq, it calls putnext_tail() * which will schedule a background thread to actually process the message. * * Assumes that there is a claim on the syncq (sq->sq_count > 0) and * SQLOCK(sq) and QLOCK(q) are not held. */ void qfill_syncq(syncq_t *sq, queue_t *q, mblk_t *mp) { queue_t *fq = NULL; ASSERT(MUTEX_NOT_HELD(SQLOCK(sq))); ASSERT(MUTEX_NOT_HELD(QLOCK(q))); ASSERT(sq->sq_count > 0); ASSERT(q->q_syncq == sq); ASSERT((sq->sq_outer == NULL && sq->sq_onext == NULL && sq->sq_oprev == NULL) || (sq->sq_outer != NULL && sq->sq_onext != NULL && sq->sq_oprev != NULL)); mutex_enter(QLOCK(q)); /* * Set QFULL in next service procedure queue (that cares) if not * already set and if there are already more messages on the syncq * than sq_max_size. If sq_max_size is 0, no flow control will be * asserted on any syncq. * * The fq here is the next queue with a service procedure. * This is where we would fail canputnext, so this is where we * need to set QFULL. * * LOCKING HIERARCHY: In the case when fq != q we need to * a) Take QLOCK(fq) to set QFULL flag and * b) Take sd_reflock in the case of the hot stream to update * sd_refcnt. * We already have QLOCK at this point. To avoid cross-locks with * freezestr() which grabs all QLOCKs and with strlock() which grabs * both SQLOCK and sd_reflock, we need to drop respective locks first. */ if ((sq_max_size != 0) && (!(q->q_nfsrv->q_flag & QFULL)) && (q->q_syncqmsgs > sq_max_size)) { if ((fq = q->q_nfsrv) == q) { fq->q_flag |= QFULL; } else { mutex_exit(QLOCK(q)); mutex_enter(QLOCK(fq)); fq->q_flag |= QFULL; mutex_exit(QLOCK(fq)); mutex_enter(QLOCK(q)); } } #ifdef DEBUG /* * This is used for debug in the qfill_syncq/qdrain_syncq case * to trace the queue that the message is intended for. Note * that the original use was to identify the queue and function * to call on the drain. In the new syncq, we have the context * of the queue that we are draining, so call it's putproc and * don't rely on the saved values. But for debug this is still * usefull information. */ mp->b_prev = (mblk_t *)q->q_qinfo->qi_putp; mp->b_queue = q; mp->b_next = NULL; #endif ASSERT(q->q_syncq == sq); /* * Enqueue the message on the list. * SQPUT_MP() accesses q_syncqmsgs. We are already holding QLOCK to * protect it. So its ok to acquire SQLOCK after SQPUT_MP(). */ SQPUT_MP(q, mp); mutex_enter(SQLOCK(sq)); /* * And queue on syncq for scheduling, if not already queued. * Note that we need the SQLOCK for this, and for testing flags * at the end to see if we will drain. So grab it now, and * release it before we call qdrain_syncq or return. */ if (!(q->q_sqflags & Q_SQQUEUED)) { q->q_spri = curthread->t_pri; SQPUT_Q(sq, q); } #ifdef DEBUG else { /* * All of these conditions MUST be true! */ ASSERT(sq->sq_tail != NULL); if (sq->sq_tail == sq->sq_head) { ASSERT((q->q_sqprev == NULL) && (q->q_sqnext == NULL)); } else { ASSERT((q->q_sqprev != NULL) || (q->q_sqnext != NULL)); } ASSERT(sq->sq_flags & SQ_QUEUED); ASSERT(q->q_syncqmsgs != 0); ASSERT(q->q_sqflags & Q_SQQUEUED); } #endif mutex_exit(QLOCK(q)); /* * SQLOCK is still held, so sq_count can be safely decremented. */ sq->sq_count--; putnext_tail(sq, q, 0); /* Should not reference sq or q after this point. */ } /* End of qfill_syncq */ /* * Remove all messages from a syncq (if qp is NULL) or remove all messages * that would be put into qp by drain_syncq. * Used when deleting the syncq (qp == NULL) or when detaching * a queue (qp != NULL). * Return non-zero if one or more messages were freed. * * no need to grab sq_putlocks here. See comment in strsubr.h that explains when * sq_putlocks are used. * * NOTE: This function assumes that it is called from the close() context and * that all the queues in the syncq are going aay. For this reason it doesn't * acquire QLOCK for modifying q_sqhead/q_sqtail fields. This assumption is * currently valid, but it is useful to rethink this function to behave properly * in other cases. */ int flush_syncq(syncq_t *sq, queue_t *qp) { mblk_t *bp, *mp_head, *mp_next, *mp_prev; queue_t *q; int ret = 0; mutex_enter(SQLOCK(sq)); /* * Before we leave, we need to make sure there are no * events listed for this queue. All events for this queue * will just be freed. */ if (qp != NULL && sq->sq_evhead != NULL) { ASSERT(sq->sq_flags & SQ_EVENTS); mp_prev = NULL; for (bp = sq->sq_evhead; bp != NULL; bp = mp_next) { mp_next = bp->b_next; if (bp->b_queue == qp) { /* Delete this message */ if (mp_prev != NULL) { mp_prev->b_next = mp_next; /* * Update sq_evtail if the last element * is removed. */ if (bp == sq->sq_evtail) { ASSERT(mp_next == NULL); sq->sq_evtail = mp_prev; } } else sq->sq_evhead = mp_next; if (sq->sq_evhead == NULL) sq->sq_flags &= ~SQ_EVENTS; bp->b_prev = bp->b_next = NULL; freemsg(bp); ret++; } else { mp_prev = bp; } } } /* * Walk sq_head and: * - match qp if qp is set, remove it's messages * - all if qp is not set */ q = sq->sq_head; while (q != NULL) { ASSERT(q->q_syncq == sq); if ((qp == NULL) || (qp == q)) { /* * Yank the messages as a list off the queue */ mp_head = q->q_sqhead; /* * We do not have QLOCK(q) here (which is safe due to * assumptions mentioned above). To obtain the lock we * need to release SQLOCK which may allow lots of things * to change upon us. This place requires more analysis. */ q->q_sqhead = q->q_sqtail = NULL; ASSERT(mp_head->b_queue && mp_head->b_queue->q_syncq == sq); /* * Free each of the messages. */ for (bp = mp_head; bp != NULL; bp = mp_next) { mp_next = bp->b_next; bp->b_prev = bp->b_next = NULL; freemsg(bp); ret++; } /* * Now remove the queue from the syncq. */ ASSERT(q->q_sqflags & Q_SQQUEUED); SQRM_Q(sq, q); q->q_spri = 0; q->q_syncqmsgs = 0; /* * If qp was specified, we are done with it and are * going to drop SQLOCK(sq) and return. We wakeup syncq * waiters while we still have the SQLOCK. */ if ((qp != NULL) && (sq->sq_flags & SQ_WANTWAKEUP)) { sq->sq_flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } /* Drop SQLOCK across clr_qfull */ mutex_exit(SQLOCK(sq)); /* * We avoid doing the test that drain_syncq does and * unconditionally clear qfull for every flushed * message. Since flush_syncq is only called during * close this should not be a problem. */ clr_qfull(q); if (qp != NULL) { return (ret); } else { mutex_enter(SQLOCK(sq)); /* * The head was removed by SQRM_Q above. * reread the new head and flush it. */ q = sq->sq_head; } } else { q = q->q_sqnext; } ASSERT(MUTEX_HELD(SQLOCK(sq))); } if (sq->sq_flags & SQ_WANTWAKEUP) { sq->sq_flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } mutex_exit(SQLOCK(sq)); return (ret); } /* * Propagate all messages from a syncq to the next syncq that are associated * with the specified queue. If the queue is attached to a driver or if the * messages have been added due to a qwriter(PERIM_INNER), free the messages. * * Assumes that the stream is strlock()'ed. We don't come here if there * are no messages to propagate. * * NOTE : If the queue is attached to a driver, all the messages are freed * as there is no point in propagating the messages from the driver syncq * to the closing stream head which will in turn get freed later. */ static int propagate_syncq(queue_t *qp) { mblk_t *bp, *head, *tail, *prev, *next; syncq_t *sq; queue_t *nqp; syncq_t *nsq; boolean_t isdriver; int moved = 0; uint16_t flags; pri_t priority = curthread->t_pri; #ifdef DEBUG void (*func)(); #endif sq = qp->q_syncq; ASSERT(MUTEX_HELD(SQLOCK(sq))); /* debug macro */ SQ_PUTLOCKS_HELD(sq); /* * As entersq() does not increment the sq_count for * the write side, check sq_count for non-QPERQ * perimeters alone. */ ASSERT((qp->q_flag & QPERQ) || (sq->sq_count >= 1)); /* * propagate_syncq() can be called because of either messages on the * queue syncq or because on events on the queue syncq. Do actual * message propagations if there are any messages. */ if (qp->q_syncqmsgs) { isdriver = (qp->q_flag & QISDRV); if (!isdriver) { nqp = qp->q_next; nsq = nqp->q_syncq; ASSERT(MUTEX_HELD(SQLOCK(nsq))); /* debug macro */ SQ_PUTLOCKS_HELD(nsq); #ifdef DEBUG func = (void (*)())nqp->q_qinfo->qi_putp; #endif } SQRM_Q(sq, qp); priority = MAX(qp->q_spri, priority); qp->q_spri = 0; head = qp->q_sqhead; tail = qp->q_sqtail; qp->q_sqhead = qp->q_sqtail = NULL; qp->q_syncqmsgs = 0; /* * Walk the list of messages, and free them if this is a driver, * otherwise reset the b_prev and b_queue value to the new putp. * Afterward, we will just add the head to the end of the next * syncq, and point the tail to the end of this one. */ for (bp = head; bp != NULL; bp = next) { next = bp->b_next; if (isdriver) { bp->b_prev = bp->b_next = NULL; freemsg(bp); continue; } /* Change the q values for this message */ bp->b_queue = nqp; #ifdef DEBUG bp->b_prev = (mblk_t *)func; #endif moved++; } /* * Attach list of messages to the end of the new queue (if there * is a list of messages). */ if (!isdriver && head != NULL) { ASSERT(tail != NULL); if (nqp->q_sqhead == NULL) { nqp->q_sqhead = head; } else { ASSERT(nqp->q_sqtail != NULL); nqp->q_sqtail->b_next = head; } nqp->q_sqtail = tail; /* * When messages are moved from high priority queue to * another queue, the destination queue priority is * upgraded. */ if (priority > nqp->q_spri) nqp->q_spri = priority; SQPUT_Q(nsq, nqp); nqp->q_syncqmsgs += moved; ASSERT(nqp->q_syncqmsgs != 0); } } /* * Before we leave, we need to make sure there are no * events listed for this queue. All events for this queue * will just be freed. */ if (sq->sq_evhead != NULL) { ASSERT(sq->sq_flags & SQ_EVENTS); prev = NULL; for (bp = sq->sq_evhead; bp != NULL; bp = next) { next = bp->b_next; if (bp->b_queue == qp) { /* Delete this message */ if (prev != NULL) { prev->b_next = next; /* * Update sq_evtail if the last element * is removed. */ if (bp == sq->sq_evtail) { ASSERT(next == NULL); sq->sq_evtail = prev; } } else sq->sq_evhead = next; if (sq->sq_evhead == NULL) sq->sq_flags &= ~SQ_EVENTS; bp->b_prev = bp->b_next = NULL; freemsg(bp); } else { prev = bp; } } } flags = sq->sq_flags; /* Wake up any waiter before leaving. */ if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } sq->sq_flags = flags; return (moved); } /* * Try and upgrade to exclusive access at the inner perimeter. If this can * not be done without blocking then request will be queued on the syncq * and drain_syncq will run it later. * * This routine can only be called from put or service procedures plus * asynchronous callback routines that have properly entered to * queue (with entersq.) Thus qwriter_inner assumes the caller has one claim * on the syncq associated with q. */ void qwriter_inner(queue_t *q, mblk_t *mp, void (*func)()) { syncq_t *sq = q->q_syncq; uint16_t count; mutex_enter(SQLOCK(sq)); count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); ASSERT(count >= 1); ASSERT(sq->sq_type & (SQ_CIPUT|SQ_CISVC)); if (count == 1) { /* * Can upgrade. This case also handles nested qwriter calls * (when the qwriter callback function calls qwriter). In that * case SQ_EXCL is already set. */ sq->sq_flags |= SQ_EXCL; SQ_PUTLOCKS_EXIT(sq); mutex_exit(SQLOCK(sq)); (*func)(q, mp); /* * Assumes that leavesq, putnext, and drain_syncq will reset * SQ_EXCL for SQ_CIPUT/SQ_CISVC queues. We leave SQ_EXCL on * until putnext, leavesq, or drain_syncq drops it. * That way we handle nested qwriter(INNER) without dropping * SQ_EXCL until the outermost qwriter callback routine is * done. */ return; } SQ_PUTLOCKS_EXIT(sq); sqfill_events(sq, q, mp, func); } /* * Synchronous callback support functions */ /* * Allocate a callback parameter structure. * Assumes that caller initializes the flags and the id. * Acquires SQLOCK(sq) if non-NULL is returned. */ callbparams_t * callbparams_alloc(syncq_t *sq, void (*func)(void *), void *arg, int kmflags) { callbparams_t *cbp; size_t size = sizeof (callbparams_t); cbp = kmem_alloc(size, kmflags & ~KM_PANIC); /* * Only try tryhard allocation if the caller is ready to panic. * Otherwise just fail. */ if (cbp == NULL) { if (kmflags & KM_PANIC) cbp = kmem_alloc_tryhard(sizeof (callbparams_t), &size, kmflags); else return (NULL); } ASSERT(size >= sizeof (callbparams_t)); cbp->cbp_size = size; cbp->cbp_sq = sq; cbp->cbp_func = func; cbp->cbp_arg = arg; mutex_enter(SQLOCK(sq)); cbp->cbp_next = sq->sq_callbpend; sq->sq_callbpend = cbp; return (cbp); } void callbparams_free(syncq_t *sq, callbparams_t *cbp) { callbparams_t **pp, *p; ASSERT(MUTEX_HELD(SQLOCK(sq))); for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { if (p == cbp) { *pp = p->cbp_next; kmem_free(p, p->cbp_size); return; } } (void) (STRLOG(0, 0, 0, SL_CONSOLE, "callbparams_free: not found\n")); } void callbparams_free_id(syncq_t *sq, callbparams_id_t id, int32_t flag) { callbparams_t **pp, *p; ASSERT(MUTEX_HELD(SQLOCK(sq))); for (pp = &sq->sq_callbpend; (p = *pp) != NULL; pp = &p->cbp_next) { if (p->cbp_id == id && p->cbp_flags == flag) { *pp = p->cbp_next; kmem_free(p, p->cbp_size); return; } } (void) (STRLOG(0, 0, 0, SL_CONSOLE, "callbparams_free_id: not found\n")); } /* * Callback wrapper function used by once-only callbacks that can be * cancelled (qtimeout and qbufcall) * Contains inline version of entersq(sq, SQ_CALLBACK) that can be * cancelled by the qun* functions. */ void qcallbwrapper(void *arg) { callbparams_t *cbp = arg; syncq_t *sq; uint16_t count = 0; uint16_t waitflags = SQ_STAYAWAY | SQ_EVENTS | SQ_EXCL; uint16_t type; sq = cbp->cbp_sq; mutex_enter(SQLOCK(sq)); type = sq->sq_type; if (!(type & SQ_CICB)) { count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SQ_PUTCOUNT_CLRFAST_LOCKED(sq); SUM_SQ_PUTCOUNTS(sq, count); sq->sq_needexcl++; ASSERT(sq->sq_needexcl != 0); /* wraparound */ waitflags |= SQ_MESSAGES; } /* Can not handle exlusive entry at outer perimeter */ ASSERT(type & SQ_COCB); while ((sq->sq_flags & waitflags) || (!(type & SQ_CICB) &&count != 0)) { if ((sq->sq_callbflags & cbp->cbp_flags) && (sq->sq_cancelid == cbp->cbp_id)) { /* timeout has been cancelled */ sq->sq_callbflags |= SQ_CALLB_BYPASSED; callbparams_free(sq, cbp); if (!(type & SQ_CICB)) { ASSERT(sq->sq_needexcl > 0); sq->sq_needexcl--; if (sq->sq_needexcl == 0) { SQ_PUTCOUNT_SETFAST_LOCKED(sq); } SQ_PUTLOCKS_EXIT(sq); } mutex_exit(SQLOCK(sq)); return; } sq->sq_flags |= SQ_WANTWAKEUP; if (!(type & SQ_CICB)) { SQ_PUTLOCKS_EXIT(sq); } cv_wait(&sq->sq_wait, SQLOCK(sq)); if (!(type & SQ_CICB)) { count = sq->sq_count; SQ_PUTLOCKS_ENTER(sq); SUM_SQ_PUTCOUNTS(sq, count); } } sq->sq_count++; ASSERT(sq->sq_count != 0); /* Wraparound */ if (!(type & SQ_CICB)) { ASSERT(count == 0); sq->sq_flags |= SQ_EXCL; ASSERT(sq->sq_needexcl > 0); sq->sq_needexcl--; if (sq->sq_needexcl == 0) { SQ_PUTCOUNT_SETFAST_LOCKED(sq); } SQ_PUTLOCKS_EXIT(sq); } mutex_exit(SQLOCK(sq)); cbp->cbp_func(cbp->cbp_arg); /* * We drop the lock only for leavesq to re-acquire it. * Possible optimization is inline of leavesq. */ mutex_enter(SQLOCK(sq)); callbparams_free(sq, cbp); mutex_exit(SQLOCK(sq)); leavesq(sq, SQ_CALLBACK); } /* * no need to grab sq_putlocks here. See comment in strsubr.h that * explains when sq_putlocks are used. * * sq_count (or one of the sq_putcounts) has already been * decremented by the caller, and if SQ_QUEUED, we need to call * drain_syncq (the global syncq drain). * If putnext_tail is called with the SQ_EXCL bit set, we are in * one of two states, non-CIPUT perimiter, and we need to clear * it, or we went exclusive in the put procedure. In any case, * we want to clear the bit now, and it is probably easier to do * this at the beginning of this function (remember, we hold * the SQLOCK). Lastly, if there are other messages queued * on the syncq (and not for our destination), enable the syncq * for background work. */ /* ARGSUSED */ void putnext_tail(syncq_t *sq, queue_t *qp, uint32_t passflags) { uint16_t flags = sq->sq_flags; ASSERT(MUTEX_HELD(SQLOCK(sq))); ASSERT(MUTEX_NOT_HELD(QLOCK(qp))); /* Clear SQ_EXCL if set in passflags */ if (passflags & SQ_EXCL) { flags &= ~SQ_EXCL; } if (flags & SQ_WANTWAKEUP) { flags &= ~SQ_WANTWAKEUP; cv_broadcast(&sq->sq_wait); } if (flags & SQ_WANTEXWAKEUP) { flags &= ~SQ_WANTEXWAKEUP; cv_broadcast(&sq->sq_exitwait); } sq->sq_flags = flags; /* * We have cleared SQ_EXCL if we were asked to, and started * the wakeup process for waiters. If there are no writers * then we need to drain the syncq if we were told to, or * enable the background thread to do it. */ if (!(flags & (SQ_STAYAWAY|SQ_EXCL))) { if ((passflags & SQ_QUEUED) || (sq->sq_svcflags & SQ_DISABLED)) { /* drain_syncq will take care of events in the list */ drain_syncq(sq); return; } else if (flags & SQ_QUEUED) { sqenable(sq); } } /* Drop the SQLOCK on exit */ mutex_exit(SQLOCK(sq)); TRACE_3(TR_FAC_STREAMS_FR, TR_PUTNEXT_END, "putnext_end:(%p, %p, %p) done", NULL, qp, sq); } void set_qend(queue_t *q) { mutex_enter(QLOCK(q)); if (!O_SAMESTR(q)) q->q_flag |= QEND; else q->q_flag &= ~QEND; mutex_exit(QLOCK(q)); q = _OTHERQ(q); mutex_enter(QLOCK(q)); if (!O_SAMESTR(q)) q->q_flag |= QEND; else q->q_flag &= ~QEND; mutex_exit(QLOCK(q)); } void clr_qfull(queue_t *q) { queue_t *oq = q; q = q->q_nfsrv; /* Fast check if there is any work to do before getting the lock. */ if ((q->q_flag & (QFULL|QWANTW)) == 0) { return; } /* * Do not reset QFULL (and backenable) if the q_count is the reason * for QFULL being set. */ mutex_enter(QLOCK(q)); /* * If both q_count and q_mblkcnt are less than the hiwat mark */ if ((q->q_count < q->q_hiwat) && (q->q_mblkcnt < q->q_hiwat)) { q->q_flag &= ~QFULL; /* * A little more confusing, how about this way: * if someone wants to write, * AND * both counts are less than the lowat mark * OR * the lowat mark is zero * THEN * backenable */ if ((q->q_flag & QWANTW) && (((q->q_count < q->q_lowat) && (q->q_mblkcnt < q->q_lowat)) || q->q_lowat == 0)) { q->q_flag &= ~QWANTW; mutex_exit(QLOCK(q)); backenable(oq, 0); } else mutex_exit(QLOCK(q)); } else mutex_exit(QLOCK(q)); } /* * Set the forward service procedure pointer. * * Called at insert-time to cache a queue's next forward service procedure in * q_nfsrv; used by canput() and canputnext(). If the queue to be inserted * has a service procedure then q_nfsrv points to itself. If the queue to be * inserted does not have a service procedure, then q_nfsrv points to the next * queue forward that has a service procedure. If the queue is at the logical * end of the stream (driver for write side, stream head for the read side) * and does not have a service procedure, then q_nfsrv also points to itself. */ void set_nfsrv_ptr( queue_t *rnew, /* read queue pointer to new module */ queue_t *wnew, /* write queue pointer to new module */ queue_t *prev_rq, /* read queue pointer to the module above */ queue_t *prev_wq) /* write queue pointer to the module above */ { queue_t *qp; if (prev_wq->q_next == NULL) { /* * Insert the driver, initialize the driver and stream head. * In this case, prev_rq/prev_wq should be the stream head. * _I_INSERT does not allow inserting a driver. Make sure * that it is not an insertion. */ ASSERT(!(rnew->q_flag & _QINSERTING)); wnew->q_nfsrv = wnew; if (rnew->q_qinfo->qi_srvp) rnew->q_nfsrv = rnew; else rnew->q_nfsrv = prev_rq; prev_rq->q_nfsrv = prev_rq; prev_wq->q_nfsrv = prev_wq; } else { /* * set up read side q_nfsrv pointer. This MUST be done * before setting the write side, because the setting of * the write side for a fifo may depend on it. * * Suppose we have a fifo that only has pipemod pushed. * pipemod has no read or write service procedures, so * nfsrv for both pipemod queues points to prev_rq (the * stream read head). Now push bufmod (which has only a * read service procedure). Doing the write side first, * wnew->q_nfsrv is set to pipemod's writeq nfsrv, which * is WRONG; the next queue forward from wnew with a * service procedure will be rnew, not the stream read head. * Since the downstream queue (which in the case of a fifo * is the read queue rnew) can affect upstream queues, it * needs to be done first. Setting up the read side first * sets nfsrv for both pipemod queues to rnew and then * when the write side is set up, wnew-q_nfsrv will also * point to rnew. */ if (rnew->q_qinfo->qi_srvp) { /* * use _OTHERQ() because, if this is a pipe, next * module may have been pushed from other end and * q_next could be a read queue. */ qp = _OTHERQ(prev_wq->q_next); while (qp && qp->q_nfsrv != qp) { qp->q_nfsrv = rnew; qp = backq(qp); } rnew->q_nfsrv = rnew; } else rnew->q_nfsrv = prev_rq->q_nfsrv; /* set up write side q_nfsrv pointer */ if (wnew->q_qinfo->qi_srvp) { wnew->q_nfsrv = wnew; /* * For insertion, need to update nfsrv of the modules * above which do not have a service routine. */ if (rnew->q_flag & _QINSERTING) { for (qp = prev_wq; qp != NULL && qp->q_nfsrv != qp; qp = backq(qp)) { qp->q_nfsrv = wnew->q_nfsrv; } } } else { if (prev_wq->q_next == prev_rq) /* * Since prev_wq/prev_rq are the middle of a * fifo, wnew/rnew will also be the middle of * a fifo and wnew's nfsrv is same as rnew's. */ wnew->q_nfsrv = rnew->q_nfsrv; else wnew->q_nfsrv = prev_wq->q_next->q_nfsrv; } } } /* * Reset the forward service procedure pointer; called at remove-time. */ void reset_nfsrv_ptr(queue_t *rqp, queue_t *wqp) { queue_t *tmp_qp; /* Reset the write side q_nfsrv pointer for _I_REMOVE */ if ((rqp->q_flag & _QREMOVING) && (wqp->q_qinfo->qi_srvp != NULL)) { for (tmp_qp = backq(wqp); tmp_qp != NULL && tmp_qp->q_nfsrv == wqp; tmp_qp = backq(tmp_qp)) { tmp_qp->q_nfsrv = wqp->q_nfsrv; } } /* reset the read side q_nfsrv pointer */ if (rqp->q_qinfo->qi_srvp) { if (wqp->q_next) { /* non-driver case */ tmp_qp = _OTHERQ(wqp->q_next); while (tmp_qp && tmp_qp->q_nfsrv == rqp) { /* Note that rqp->q_next cannot be NULL */ ASSERT(rqp->q_next != NULL); tmp_qp->q_nfsrv = rqp->q_next->q_nfsrv; tmp_qp = backq(tmp_qp); } } } } /* * This routine should be called after all stream geometry changes to update * the stream head cached struio() rd/wr queue pointers. Note must be called * with the streamlock()ed. * * Note: only enables Synchronous STREAMS for a side of a Stream which has * an explicit synchronous barrier module queue. That is, a queue that * has specified a struio() type. */ static void strsetuio(stdata_t *stp) { queue_t *wrq; if (stp->sd_flag & STPLEX) { /* * Not stremahead, but a mux, so no Synchronous STREAMS. */ stp->sd_struiowrq = NULL; stp->sd_struiordq = NULL; return; } /* * Scan the write queue(s) while synchronous * until we find a qinfo uio type specified. */ wrq = stp->sd_wrq->q_next; while (wrq) { if (wrq->q_struiot == STRUIOT_NONE) { wrq = 0; break; } if (wrq->q_struiot != STRUIOT_DONTCARE) break; if (! _SAMESTR(wrq)) { wrq = 0; break; } wrq = wrq->q_next; } stp->sd_struiowrq = wrq; /* * Scan the read queue(s) while synchronous * until we find a qinfo uio type specified. */ wrq = stp->sd_wrq->q_next; while (wrq) { if (_RD(wrq)->q_struiot == STRUIOT_NONE) { wrq = 0; break; } if (_RD(wrq)->q_struiot != STRUIOT_DONTCARE) break; if (! _SAMESTR(wrq)) { wrq = 0; break; } wrq = wrq->q_next; } stp->sd_struiordq = wrq ? _RD(wrq) : 0; } /* * pass_wput, unblocks the passthru queues, so that * messages can arrive at muxs lower read queue, before * I_LINK/I_UNLINK is acked/nacked. */ static void pass_wput(queue_t *q, mblk_t *mp) { syncq_t *sq; sq = _RD(q)->q_syncq; if (sq->sq_flags & SQ_BLOCKED) unblocksq(sq, SQ_BLOCKED, 0); putnext(q, mp); } /* * Set up queues for the link/unlink. * Create a new queue and block it and then insert it * below the stream head on the lower stream. * This prevents any messages from arriving during the setq * as well as while the mux is processing the LINK/I_UNLINK. * The blocked passq is unblocked once the LINK/I_UNLINK has * been acked or nacked or if a message is generated and sent * down muxs write put procedure. * see pass_wput(). * * After the new queue is inserted, all messages coming from below are * blocked. The call to strlock will ensure that all activity in the stream head * read queue syncq is stopped (sq_count drops to zero). */ static queue_t * link_addpassthru(stdata_t *stpdown) { queue_t *passq; sqlist_t sqlist; passq = allocq(); STREAM(passq) = STREAM(_WR(passq)) = stpdown; /* setq might sleep in allocator - avoid holding locks. */ setq(passq, &passthru_rinit, &passthru_winit, NULL, QPERQ, SQ_CI|SQ_CO, B_FALSE); claimq(passq); blocksq(passq->q_syncq, SQ_BLOCKED, 1); insertq(STREAM(passq), passq); /* * Use strlock() to wait for the stream head sq_count to drop to zero * since we are going to change q_ptr in the stream head. Note that * insertq() doesn't wait for any syncq counts to drop to zero. */ sqlist.sqlist_head = NULL; sqlist.sqlist_index = 0; sqlist.sqlist_size = sizeof (sqlist_t); sqlist_insert(&sqlist, _RD(stpdown->sd_wrq)->q_syncq); strlock(stpdown, &sqlist); strunlock(stpdown, &sqlist); releaseq(passq); return (passq); } /* * Let messages flow up into the mux by removing * the passq. */ static void link_rempassthru(queue_t *passq) { claimq(passq); removeq(passq); releaseq(passq); freeq(passq); } /* * Wait for the condition variable pointed to by `cvp' to be signaled, * or for `tim' milliseconds to elapse, whichever comes first. If `tim' * is negative, then there is no time limit. If `nosigs' is non-zero, * then the wait will be non-interruptible. * * Returns >0 if signaled, 0 if interrupted, or -1 upon timeout. */ clock_t str_cv_wait(kcondvar_t *cvp, kmutex_t *mp, clock_t tim, int nosigs) { clock_t ret, now, tick; if (tim < 0) { if (nosigs) { cv_wait(cvp, mp); ret = 1; } else { ret = cv_wait_sig(cvp, mp); } } else if (tim > 0) { /* * convert milliseconds to clock ticks */ tick = MSEC_TO_TICK_ROUNDUP(tim); time_to_wait(&now, tick); if (nosigs) { ret = cv_timedwait(cvp, mp, now); } else { ret = cv_timedwait_sig(cvp, mp, now); } } else { ret = -1; } return (ret); } /* * Wait until the stream head can determine if it is at the mark but * don't wait forever to prevent a race condition between the "mark" state * in the stream head and any mark state in the caller/user of this routine. * * This is used by sockets and for a socket it would be incorrect * to return a failure for SIOCATMARK when there is no data in the receive * queue and the marked urgent data is traveling up the stream. * * This routine waits until the mark is known by waiting for one of these * three events: * The stream head read queue becoming non-empty (including an EOF) * The STRATMARK flag being set. (Due to a MSGMARKNEXT message.) * The STRNOTATMARK flag being set (which indicates that the transport * has sent a MSGNOTMARKNEXT message to indicate that it is not at * the mark). * * The routine returns 1 if the stream is at the mark; 0 if it can * be determined that the stream is not at the mark. * If the wait times out and it can't determine * whether or not the stream might be at the mark the routine will return -1. * * Note: This routine should only be used when a mark is pending i.e., * in the socket case the SIGURG has been posted. * Note2: This can not wakeup just because synchronous streams indicate * that data is available since it is not possible to use the synchronous * streams interfaces to determine the b_flag value for the data queued below * the stream head. */ int strwaitmark(vnode_t *vp) { struct stdata *stp = vp->v_stream; queue_t *rq = _RD(stp->sd_wrq); int mark; mutex_enter(&stp->sd_lock); while (rq->q_first == NULL && !(stp->sd_flag & (STRATMARK|STRNOTATMARK|STREOF))) { stp->sd_flag |= RSLEEP; /* Wait for 100 milliseconds for any state change. */ if (str_cv_wait(&rq->q_wait, &stp->sd_lock, 100, 1) == -1) { mutex_exit(&stp->sd_lock); return (-1); } } if (stp->sd_flag & STRATMARK) mark = 1; else if (rq->q_first != NULL && (rq->q_first->b_flag & MSGMARK)) mark = 1; else mark = 0; mutex_exit(&stp->sd_lock); return (mark); } /* * Set a read side error. If persist is set change the socket error * to persistent. If errfunc is set install the function as the exported * error handler. */ void strsetrerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); stp->sd_rerror = error; if (error == 0 && errfunc == NULL) stp->sd_flag &= ~STRDERR; else stp->sd_flag |= STRDERR; if (persist) { stp->sd_flag &= ~STRDERRNONPERSIST; } else { stp->sd_flag |= STRDERRNONPERSIST; } stp->sd_rderrfunc = errfunc; if (error != 0 || errfunc != NULL) { cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ cv_broadcast(&stp->sd_monitor); /* ioctllers */ mutex_exit(&stp->sd_lock); pollwakeup(&stp->sd_pollist, POLLERR); mutex_enter(&stp->sd_lock); if (stp->sd_sigflags & S_ERROR) strsendsig(stp->sd_siglist, S_ERROR, 0, error); } mutex_exit(&stp->sd_lock); } /* * Set a write side error. If persist is set change the socket error * to persistent. */ void strsetwerror(vnode_t *vp, int error, int persist, errfunc_t errfunc) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); stp->sd_werror = error; if (error == 0 && errfunc == NULL) stp->sd_flag &= ~STWRERR; else stp->sd_flag |= STWRERR; if (persist) { stp->sd_flag &= ~STWRERRNONPERSIST; } else { stp->sd_flag |= STWRERRNONPERSIST; } stp->sd_wrerrfunc = errfunc; if (error != 0 || errfunc != NULL) { cv_broadcast(&_RD(stp->sd_wrq)->q_wait); /* readers */ cv_broadcast(&stp->sd_wrq->q_wait); /* writers */ cv_broadcast(&stp->sd_monitor); /* ioctllers */ mutex_exit(&stp->sd_lock); pollwakeup(&stp->sd_pollist, POLLERR); mutex_enter(&stp->sd_lock); if (stp->sd_sigflags & S_ERROR) strsendsig(stp->sd_siglist, S_ERROR, 0, error); } mutex_exit(&stp->sd_lock); } /* * Make the stream return 0 (EOF) when all data has been read. * No effect on write side. */ void strseteof(vnode_t *vp, int eof) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); if (!eof) { stp->sd_flag &= ~STREOF; mutex_exit(&stp->sd_lock); return; } stp->sd_flag |= STREOF; if (stp->sd_flag & RSLEEP) { stp->sd_flag &= ~RSLEEP; cv_broadcast(&_RD(stp->sd_wrq)->q_wait); } mutex_exit(&stp->sd_lock); pollwakeup(&stp->sd_pollist, POLLIN|POLLRDNORM); mutex_enter(&stp->sd_lock); if (stp->sd_sigflags & (S_INPUT|S_RDNORM)) strsendsig(stp->sd_siglist, S_INPUT|S_RDNORM, 0, 0); mutex_exit(&stp->sd_lock); } void strflushrq(vnode_t *vp, int flag) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); flushq(_RD(stp->sd_wrq), flag); mutex_exit(&stp->sd_lock); } void strsetrputhooks(vnode_t *vp, uint_t flags, msgfunc_t protofunc, msgfunc_t miscfunc) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); if (protofunc == NULL) stp->sd_rprotofunc = strrput_proto; else stp->sd_rprotofunc = protofunc; if (miscfunc == NULL) stp->sd_rmiscfunc = strrput_misc; else stp->sd_rmiscfunc = miscfunc; if (flags & SH_CONSOL_DATA) stp->sd_rput_opt |= SR_CONSOL_DATA; else stp->sd_rput_opt &= ~SR_CONSOL_DATA; if (flags & SH_SIGALLDATA) stp->sd_rput_opt |= SR_SIGALLDATA; else stp->sd_rput_opt &= ~SR_SIGALLDATA; if (flags & SH_IGN_ZEROLEN) stp->sd_rput_opt |= SR_IGN_ZEROLEN; else stp->sd_rput_opt &= ~SR_IGN_ZEROLEN; mutex_exit(&stp->sd_lock); } void strsetwputhooks(vnode_t *vp, uint_t flags, clock_t closetime) { struct stdata *stp = vp->v_stream; mutex_enter(&stp->sd_lock); stp->sd_closetime = closetime; if (flags & SH_SIGPIPE) stp->sd_wput_opt |= SW_SIGPIPE; else stp->sd_wput_opt &= ~SW_SIGPIPE; if (flags & SH_RECHECK_ERR) stp->sd_wput_opt |= SW_RECHECK_ERR; else stp->sd_wput_opt &= ~SW_RECHECK_ERR; mutex_exit(&stp->sd_lock); } /* Used within framework when the queue is already locked */ void qenable_locked(queue_t *q) { stdata_t *stp = STREAM(q); ASSERT(MUTEX_HELD(QLOCK(q))); if (!q->q_qinfo->qi_srvp) return; /* * Do not place on run queue if already enabled or closing. */ if (q->q_flag & (QWCLOSE|QENAB)) return; /* * mark queue enabled and place on run list if it is not already being * serviced. If it is serviced, the runservice() function will detect * that QENAB is set and call service procedure before clearing * QINSERVICE flag. */ q->q_flag |= QENAB; if (q->q_flag & QINSERVICE) return; /* Record the time of qenable */ q->q_qtstamp = lbolt; /* * Put the queue in the stp list and schedule it for background * processing if it is not already scheduled or if stream head does not * intent to process it in the foreground later by setting * STRS_WILLSERVICE flag. */ mutex_enter(&stp->sd_qlock); /* * If there are already something on the list, stp flags should show * intention to drain it. */ IMPLY(STREAM_NEEDSERVICE(stp), (stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))); ENQUEUE(q, stp->sd_qhead, stp->sd_qtail, q_link); stp->sd_nqueues++; /* * If no one will drain this stream we are the first producer and * need to schedule it for background thread. */ if (!(stp->sd_svcflags & (STRS_WILLSERVICE | STRS_SCHEDULED))) { /* * No one will service this stream later, so we have to * schedule it now. */ STRSTAT(stenables); stp->sd_svcflags |= STRS_SCHEDULED; stp->sd_servid = (void *)taskq_dispatch(streams_taskq, (task_func_t *)stream_service, stp, TQ_NOSLEEP|TQ_NOQUEUE); if (stp->sd_servid == NULL) { /* * Task queue failed so fail over to the backup * servicing thread. */ STRSTAT(taskqfails); /* * It is safe to clear STRS_SCHEDULED flag because it * was set by this thread above. */ stp->sd_svcflags &= ~STRS_SCHEDULED; /* * Failover scheduling is protected by service_queue * lock. */ mutex_enter(&service_queue); ASSERT((stp->sd_qhead == q) && (stp->sd_qtail == q)); ASSERT(q->q_link == NULL); /* * Append the queue to qhead/qtail list. */ if (qhead == NULL) qhead = q; else qtail->q_link = q; qtail = q; /* * Clear stp queue list. */ stp->sd_qhead = stp->sd_qtail = NULL; stp->sd_nqueues = 0; /* * Wakeup background queue processing thread. */ cv_signal(&services_to_run); mutex_exit(&service_queue); } } mutex_exit(&stp->sd_qlock); } static void queue_service(queue_t *q) { /* * The queue in the list should have * QENAB flag set and should not have * QINSERVICE flag set. QINSERVICE is * set when the queue is dequeued and * qenable_locked doesn't enqueue a * queue with QINSERVICE set. */ ASSERT(!(q->q_flag & QINSERVICE)); ASSERT((q->q_flag & QENAB)); mutex_enter(QLOCK(q)); q->q_flag &= ~QENAB; q->q_flag |= QINSERVICE; mutex_exit(QLOCK(q)); runservice(q); } static void syncq_service(syncq_t *sq) { STRSTAT(syncqservice); mutex_enter(SQLOCK(sq)); ASSERT(!(sq->sq_svcflags & SQ_SERVICE)); ASSERT(sq->sq_servcount != 0); ASSERT(sq->sq_next == NULL); /* if we came here from the background thread, clear the flag */ if (sq->sq_svcflags & SQ_BGTHREAD) sq->sq_svcflags &= ~SQ_BGTHREAD; /* let drain_syncq know that it's being called in the background */ sq->sq_svcflags |= SQ_SERVICE; drain_syncq(sq); } static void qwriter_outer_service(syncq_t *outer) { /* * Note that SQ_WRITER is used on the outer perimeter * to signal that a qwriter(OUTER) is either investigating * running or that it is actually running a function. */ outer_enter(outer, SQ_BLOCKED|SQ_WRITER); /* * All inner syncq are empty and have SQ_WRITER set * to block entering the outer perimeter. * * We do not need to explicitly call write_now since * outer_exit does it for us. */ outer_exit(outer); } static void mblk_free(mblk_t *mp) { dblk_t *dbp = mp->b_datap; frtn_t *frp = dbp->db_frtnp; mp->b_next = NULL; if (dbp->db_fthdr != NULL) str_ftfree(dbp); ASSERT(dbp->db_fthdr == NULL); frp->free_func(frp->free_arg); ASSERT(dbp->db_mblk == mp); if (dbp->db_credp != NULL) { crfree(dbp->db_credp); dbp->db_credp = NULL; } dbp->db_cpid = -1; dbp->db_struioflag = 0; dbp->db_struioun.cksum.flags = 0; kmem_cache_free(dbp->db_cache, dbp); } /* * Background processing of the stream queue list. */ static void stream_service(stdata_t *stp) { queue_t *q; mutex_enter(&stp->sd_qlock); STR_SERVICE(stp, q); stp->sd_svcflags &= ~STRS_SCHEDULED; stp->sd_servid = NULL; cv_signal(&stp->sd_qcv); mutex_exit(&stp->sd_qlock); } /* * Foreground processing of the stream queue list. */ void stream_runservice(stdata_t *stp) { queue_t *q; mutex_enter(&stp->sd_qlock); STRSTAT(rservice); /* * We are going to drain this stream queue list, so qenable_locked will * not schedule it until we finish. */ stp->sd_svcflags |= STRS_WILLSERVICE; STR_SERVICE(stp, q); stp->sd_svcflags &= ~STRS_WILLSERVICE; mutex_exit(&stp->sd_qlock); /* * Help backup background thread to drain the qhead/qtail list. */ while (qhead != NULL) { STRSTAT(qhelps); mutex_enter(&service_queue); DQ(q, qhead, qtail, q_link); mutex_exit(&service_queue); if (q != NULL) queue_service(q); } } void stream_willservice(stdata_t *stp) { mutex_enter(&stp->sd_qlock); stp->sd_svcflags |= STRS_WILLSERVICE; mutex_exit(&stp->sd_qlock); } /* * Replace the cred currently in the mblk with a different one. */ void mblk_setcred(mblk_t *mp, cred_t *cr) { cred_t *ocr = DB_CRED(mp); ASSERT(cr != NULL); if (cr != ocr) { crhold(mp->b_datap->db_credp = cr); if (ocr != NULL) crfree(ocr); } } int hcksum_assoc(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, uint32_t start, uint32_t stuff, uint32_t end, uint32_t value, uint32_t flags, int km_flags) { int rc = 0; ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); if (mp->b_datap->db_type == M_DATA) { /* Associate values for M_DATA type */ mp->b_datap->db_cksumstart = (intptr_t)start; mp->b_datap->db_cksumstuff = (intptr_t)stuff; mp->b_datap->db_cksumend = (intptr_t)end; mp->b_datap->db_struioun.cksum.flags = flags; mp->b_datap->db_cksum16 = (uint16_t)value; } else { pattrinfo_t pa_info; ASSERT(mmd != NULL); pa_info.type = PATTR_HCKSUM; pa_info.len = sizeof (pattr_hcksum_t); if (mmd_addpattr(mmd, pd, &pa_info, B_TRUE, km_flags) != NULL) { pattr_hcksum_t *hck = (pattr_hcksum_t *)pa_info.buf; hck->hcksum_start_offset = start; hck->hcksum_stuff_offset = stuff; hck->hcksum_end_offset = end; hck->hcksum_cksum_val.inet_cksum = (uint16_t)value; hck->hcksum_flags = flags; } } return (rc); } void hcksum_retrieve(mblk_t *mp, multidata_t *mmd, pdesc_t *pd, uint32_t *start, uint32_t *stuff, uint32_t *end, uint32_t *value, uint32_t *flags) { ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); if (mp->b_datap->db_type == M_DATA) { if (flags != NULL) { *flags = mp->b_datap->db_struioun.cksum.flags; if (*flags & HCK_PARTIALCKSUM) { if (start != NULL) *start = (uint32_t) mp->b_datap->db_cksumstart; if (stuff != NULL) *stuff = (uint32_t) mp->b_datap->db_cksumstuff; if (end != NULL) *end = (uint32_t)mp->b_datap->db_cksumend; if (value != NULL) *value = (uint32_t)mp->b_datap->db_cksum16; } } } else { pattrinfo_t hck_attr = {PATTR_HCKSUM}; ASSERT(mmd != NULL); /* get hardware checksum attribute */ if (mmd_getpattr(mmd, pd, &hck_attr) != NULL) { pattr_hcksum_t *hck = (pattr_hcksum_t *)hck_attr.buf; ASSERT(hck_attr.len >= sizeof (pattr_hcksum_t)); if (flags != NULL) *flags = hck->hcksum_flags; if (start != NULL) *start = hck->hcksum_start_offset; if (stuff != NULL) *stuff = hck->hcksum_stuff_offset; if (end != NULL) *end = hck->hcksum_end_offset; if (value != NULL) *value = (uint32_t) hck->hcksum_cksum_val.inet_cksum; } } } /* * Checksum buffer *bp for len bytes with psum partial checksum, * or 0 if none, and return the 16 bit partial checksum. */ unsigned bcksum(uchar_t *bp, int len, unsigned int psum) { int odd = len & 1; extern unsigned int ip_ocsum(); if (((intptr_t)bp & 1) == 0 && !odd) { /* * Bp is 16 bit aligned and len is multiple of 16 bit word. */ return (ip_ocsum((ushort_t *)bp, len >> 1, psum)); } if (((intptr_t)bp & 1) != 0) { /* * Bp isn't 16 bit aligned. */ unsigned int tsum; #ifdef _LITTLE_ENDIAN psum += *bp; #else psum += *bp << 8; #endif len--; bp++; tsum = ip_ocsum((ushort_t *)bp, len >> 1, 0); psum += (tsum << 8) & 0xffff | (tsum >> 8); if (len & 1) { bp += len - 1; #ifdef _LITTLE_ENDIAN psum += *bp << 8; #else psum += *bp; #endif } } else { /* * Bp is 16 bit aligned. */ psum = ip_ocsum((ushort_t *)bp, len >> 1, psum); if (odd) { bp += len - 1; #ifdef _LITTLE_ENDIAN psum += *bp; #else psum += *bp << 8; #endif } } /* * Normalize psum to 16 bits before returning the new partial * checksum. The max psum value before normalization is 0x3FDFE. */ return ((psum >> 16) + (psum & 0xFFFF)); } boolean_t is_vmloaned_mblk(mblk_t *mp, multidata_t *mmd, pdesc_t *pd) { boolean_t rc; ASSERT(DB_TYPE(mp) == M_DATA || DB_TYPE(mp) == M_MULTIDATA); if (DB_TYPE(mp) == M_DATA) { rc = (((mp)->b_datap->db_struioflag & STRUIO_ZC) != 0); } else { pattrinfo_t zcopy_attr = {PATTR_ZCOPY}; ASSERT(mmd != NULL); rc = (mmd_getpattr(mmd, pd, &zcopy_attr) != NULL); } return (rc); } void freemsgchain(mblk_t *mp) { mblk_t *next; while (mp != NULL) { next = mp->b_next; mp->b_next = NULL; freemsg(mp); mp = next; } } mblk_t * copymsgchain(mblk_t *mp) { mblk_t *nmp = NULL; mblk_t **nmpp = &nmp; for (; mp != NULL; mp = mp->b_next) { if ((*nmpp = copymsg(mp)) == NULL) { freemsgchain(nmp); return (NULL); } nmpp = &((*nmpp)->b_next); } return (nmp); } /* NOTE: Do not add code after this point. */ #undef QLOCK /* * replacement for QLOCK macro for those that can't use it. */ kmutex_t * QLOCK(queue_t *q) { return (&(q)->q_lock); } /* * Dummy runqueues/queuerun functions functions for backwards compatibility. */ #undef runqueues void runqueues(void) { } #undef queuerun void queuerun(void) { }