/* * CDDL HEADER START * * The contents of this file are subject to the terms of the * Common Development and Distribution License (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 2008 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 #undef ct_lock /* needed because clnt.h defines ct_lock as a macro */ /* * Device Contracts * ----------------- * This file contains the core code for the device contracts framework. * A device contract is an agreement or a contract between a process and * the kernel regarding the state of the device. A device contract may be * created when a relationship is formed between a device and a process * i.e. at open(2) time, or it may be created at some point after the device * has been opened. A device contract once formed may be broken by either party. * A device contract can be broken by the process by an explicit abandon of the * contract or by an implicit abandon when the process exits. A device contract * can be broken by the kernel either asynchronously (without negotiation) or * synchronously (with negotiation). Exactly which happens depends on the device * state transition. The following state diagram shows the transitions between * device states. Only device state transitions currently supported by device * contracts is shown. * * <-- A --> * /-----------------> DEGRADED * | | * | | * | | S * | | | * | | v * v S --> v * ONLINE ------------> OFFLINE * * * In the figure above, the arrows indicate the direction of transition. The * letter S refers to transitions which are inherently synchronous i.e. * require negotiation and the letter A indicates transitions which are * asynchronous i.e. are done without contract negotiations. A good example * of a synchronous transition is the ONLINE -> OFFLINE transition. This * transition cannot happen as long as there are consumers which have the * device open. Thus some form of negotiation needs to happen between the * consumers and the kernel to ensure that consumers either close devices * or disallow the move to OFFLINE. Certain other transitions such as * ONLINE --> DEGRADED for example, are inherently asynchronous i.e. * non-negotiable. A device that suffers a fault that degrades its * capabilities will become degraded irrespective of what consumers it has, * so a negotiation in this case is pointless. * * The following device states are currently defined for device contracts: * * CT_DEV_EV_ONLINE * The device is online and functioning normally * CT_DEV_EV_DEGRADED * The device is online but is functioning in a degraded capacity * CT_DEV_EV_OFFLINE * The device is offline and is no longer configured * * A typical consumer of device contracts starts out with a contract * template and adds terms to that template. These include the * "acceptable set" (A-set) term, which is a bitset of device states which * are guaranteed by the contract. If the device moves out of a state in * the A-set, the contract is broken. The breaking of the contract can * be asynchronous in which case a critical contract event is sent to the * contract holder but no negotiations take place. If the breaking of the * contract is synchronous, negotations are opened between the affected * consumer and the kernel. The kernel does this by sending a critical * event to the consumer with the CTE_NEG flag set indicating that this * is a negotiation event. The consumer can accept this change by sending * a ACK message to the kernel. Alternatively, if it has the necessary * privileges, it can send a NACK message to the kernel which will block * the device state change. To NACK a negotiable event, a process must * have the {PRIV_SYS_DEVICES} privilege asserted in its effective set. * * Other terms include the "minor path" term, specified explicitly if the * contract is not being created at open(2) time or specified implicitly * if the contract is being created at open time via an activated template. * * A contract event is sent on any state change to which the contract * owner has subscribed via the informative or critical event sets. Only * critical events are guaranteed to be delivered. Since all device state * changes are controlled by the kernel and cannot be arbitrarily generated * by a non-privileged user, the {PRIV_CONTRACT_EVENT} privilege does not * need to be asserted in a process's effective set to designate an event as * critical. To ensure privacy, a process must either have the same effective * userid as the contract holder or have the {PRIV_CONTRACT_OBSERVER} privilege * asserted in its effective set in order to observe device contract events * off the device contract type specific endpoint. * * Yet another term available with device contracts is the "non-negotiable" * term. This term is used to pre-specify a NACK to any contract negotiation. * This term is ignored for asynchronous state changes. For example, a * provcess may have the A-set {ONLINE|DEGRADED} and make the contract * non-negotiable. In this case, the device contract framework assumes a * NACK for any transition to OFFLINE and blocks the offline. If the A-set * is {ONLINE} and the non-negotiable term is set, transitions to OFFLINE * are NACKed but transitions to DEGRADE succeed. * * The OFFLINE negotiation (if OFFLINE state is not in the A-set for a contract) * happens just before the I/O framework attempts to offline a device * (i.e. detach a device and set the offline flag so that it cannot be * reattached). A device contract holder is expected to either NACK the offline * (if privileged) or release the device and allow the offline to proceed. * * The DEGRADE contract event (if DEGRADE is not in the A-set for a contract) * is generated just before the I/O framework transitions the device state * to "degraded" (i.e. DEVI_DEVICE_DEGRADED in I/O framework terminology). * * The contract holder is expected to ACK or NACK a negotiation event * within a certain period of time. If the ACK/NACK is not received * within the timeout period, the device contract framework will behave * as if the contract does not exist and will proceed with the event. * * Unlike a process contract a device contract does not need to exist * once it is abandoned, since it does not define a fault boundary. It * merely represents an agreement between a process and the kernel * regarding the state of the device. Once the process has abandoned * the contract (either implicitly via a process exit or explicitly) * the kernel has no reason to retain the contract. As a result * device contracts are neither inheritable nor need to exist in an * orphan state. * * A device unlike a process may exist in multiple contracts and has * a "life" outside a device contract. A device unlike a process * may exist without an associated contract. Unlike a process contract * a device contract may be formed after a binding relationship is * formed between a process and a device. * * IMPLEMENTATION NOTES * ==================== * DATA STRUCTURES * ---------------- * The heart of the device contracts implementation is the device contract * private cont_device_t (or ctd for short) data structure. It encapsulates * the generic contract_t data structure and has a number of private * fields. * These include: * cond_minor: The minor device that is the subject of the contract * cond_aset: The bitset of states which are guaranteed by the * contract * cond_noneg: If set, indicates that the result of negotiation has * been predefined to be a NACK * In addition, there are other device identifiers such the devinfo node, * dev_t and spec_type of the minor node. There are also a few fields that * are used during negotiation to maintain state. See * uts/common/sys/contract/device_impl.h * for details. * The ctd structure represents the device private part of a contract of * type "device" * * Another data structure used by device contracts is ctmpl_device. It is * the device contracts private part of the contract template structure. It * encapsulates the generic template structure "ct_template_t" and includes * the following device contract specific fields * ctd_aset: The bitset of states that should be guaranteed by a * contract * ctd_noneg: If set, indicates that contract should NACK a * negotiation * ctd_minor: The devfs_path (without the /devices prefix) of the * minor node that is the subject of the contract. * * ALGORITHMS * --------- * There are three sets of routines in this file * Template related routines * ------------------------- * These routines provide support for template related operations initated * via the generic template operations. These include routines that dup * a template, free it, and set various terms in the template * (such as the minor node path, the acceptable state set (or A-set) * and the non-negotiable term) as well as a routine to query the * device specific portion of the template for the abovementioned terms. * There is also a routine to create (ctmpl_device_create) that is used to * create a contract from a template. This routine calls (after initial * setup) the common function used to create a device contract * (contract_device_create). * * core device contract implementation * ---------------------------------- * These routines support the generic contract framework to provide * functionality that allows contracts to be created, managed and * destroyed. The contract_device_create() routine is a routine used * to create a contract from a template (either via an explicit create * operation on a template or implicitly via an open with an * activated template.). The contract_device_free() routine assists * in freeing the device contract specific parts. There are routines * used to abandon (contract_device_abandon) a device contract as well * as a routine to destroy (which despite its name does not destroy, * it only moves a contract to a dead state) a contract. * There is also a routine to return status information about a * contract - the level of detail depends on what is requested by the * user. A value of CTD_FIXED only returns fixed length fields such * as the A-set, state of device and value of the "noneg" term. If * CTD_ALL is specified, the minor node path is returned as well. * * In addition there are interfaces (contract_device_ack/nack) which * are used to support negotiation between userland processes and * device contracts. These interfaces record the acknowledgement * or lack thereof for negotiation events and help determine if the * negotiated event should occur. * * "backend routines" * ----------------- * The backend routines form the interface between the I/O framework * and the device contract subsystem. These routines, allow the I/O * framework to call into the device contract subsystem to notify it of * impending changes to a device state as well as to inform of the * final disposition of such attempted state changes. Routines in this * class include contract_device_offline() that indicates an attempt to * offline a device, contract_device_degrade() that indicates that * a device is moving to the degraded state and contract_device_negend() * that is used by the I/O framework to inform the contracts subsystem of * the final disposition of an attempted operation. * * SUMMARY * ------- * A contract starts its life as a template. A process allocates a device * contract template and sets various terms: * The A-set * The device minor node * Critical and informative events * The noneg i.e. no negotition term * Setting of these terms in the template is done via the * ctmpl_device_set() entry point in this file. A process can query a * template to determine the terms already set in the template - this is * facilitated by the ctmpl_device_get() routine. * * Once all the appropriate terms are set, the contract is instantiated via * one of two methods * - via an explicit create operation - this is facilitated by the * ctmpl_device_create() entry point * - synchronously with the open(2) system call - this is achieved via the * contract_device_open() routine. * The core work for both these above functions is done by * contract_device_create() * * A contract once created can be queried for its status. Support for * status info is provided by both the common contracts framework and by * the "device" contract type. If the level of detail requested is * CTD_COMMON, only the common contract framework data is used. Higher * levels of detail result in calls to contract_device_status() to supply * device contract type specific status information. * * A contract once created may be abandoned either explicitly or implictly. * In either case, the contract_device_abandon() function is invoked. This * function merely calls contract_destroy() which moves the contract to * the DEAD state. The device contract portion of destroy processing is * provided by contract_device_destroy() which merely disassociates the * contract from its device devinfo node. A contract in the DEAD state is * not freed. It hanbgs around until all references to the contract are * gone. When that happens, the contract is finally deallocated. The * device contract specific portion of the free is done by * contract_device_free() which finally frees the device contract specific * data structure (cont_device_t). * * When a device undergoes a state change, the I/O framework calls the * corresponding device contract entry point. For example, when a device * is about to go OFFLINE, the routine contract_device_offline() is * invoked. Similarly if a device moves to DEGRADED state, the routine * contract_device_degrade() function is called. These functions call the * core routine contract_device_publish(). This function determines via * the function is_sync_neg() whether an event is a synchronous (i.e. * negotiable) event or not. In the former case contract_device_publish() * publishes a CTE_NEG event and then waits in wait_for_acks() for ACKs * and/or NACKs from contract holders. In the latter case, it simply * publishes the event and does not wait. In the negotiation case, ACKs or * NACKs from userland consumers results in contract_device_ack_nack() * being called where the result of the negotiation is recorded in the * contract data structure. Once all outstanding contract owners have * responded, the device contract code in wait_for_acks() determines the * final result of the negotiation. A single NACK overrides all other ACKs * If there is no NACK, then a single ACK will result in an overall ACK * result. If there are no ACKs or NACKs, then the result CT_NONE is * returned back to the I/O framework. Once the event is permitted or * blocked, the I/O framework proceeds or aborts the state change. The * I/O framework then calls contract_device_negend() with a result code * indicating final disposition of the event. This call releases the * barrier and other state associated with the previous negotiation, * which permits the next event (if any) to come into the device contract * framework. * * Finally, a device that has outstanding contracts may be removed from * the system which results in its devinfo node being freed. The devinfo * free routine in the I/O framework, calls into the device contract * function - contract_device_remove_dip(). This routine, disassociates * the dip from all contracts associated with the contract being freed, * allowing the devinfo node to be freed. * * LOCKING * --------- * There are four sets of data that need to be protected by locks * * i) device contract specific portion of the contract template - This data * is protected by the template lock ctmpl_lock. * * ii) device contract specific portion of the contract - This data is * protected by the contract lock ct_lock * * iii) The linked list of contracts hanging off a devinfo node - This * list is protected by the per-devinfo node lock devi_ct_lock * * iv) Finally there is a barrier, controlled by devi_ct_lock, devi_ct_cv * and devi_ct_count that controls state changes to a dip * * The template lock is independent in that none of the other locks in this * file may be taken while holding the template lock (and vice versa). * * The remaining three locks have the following lock order * * devi_ct_lock -> ct_count barrier -> ct_lock * */ static cont_device_t *contract_device_create(ctmpl_device_t *dtmpl, dev_t dev, int spec_type, proc_t *owner, int *errorp); /* barrier routines */ static void ct_barrier_acquire(dev_info_t *dip); static void ct_barrier_release(dev_info_t *dip); static int ct_barrier_held(dev_info_t *dip); static int ct_barrier_empty(dev_info_t *dip); static void ct_barrier_wait_for_release(dev_info_t *dip); static int ct_barrier_wait_for_empty(dev_info_t *dip, int secs); static void ct_barrier_decr(dev_info_t *dip); static void ct_barrier_incr(dev_info_t *dip); ct_type_t *device_type; /* * Macro predicates for determining when events should be sent and how. */ #define EVSENDP(ctd, flag) \ ((ctd->cond_contract.ct_ev_info | ctd->cond_contract.ct_ev_crit) & flag) #define EVINFOP(ctd, flag) \ ((ctd->cond_contract.ct_ev_crit & flag) == 0) /* * State transition table showing which transitions are synchronous and which * are not. */ struct ct_dev_negtable { uint_t st_old; uint_t st_new; uint_t st_neg; } ct_dev_negtable[] = { {CT_DEV_EV_ONLINE, CT_DEV_EV_OFFLINE, 1}, {CT_DEV_EV_ONLINE, CT_DEV_EV_DEGRADED, 0}, {CT_DEV_EV_DEGRADED, CT_DEV_EV_ONLINE, 0}, {CT_DEV_EV_DEGRADED, CT_DEV_EV_OFFLINE, 1}, {0} }; /* * Device contract template implementation */ /* * ctmpl_device_dup * * The device contract template dup entry point. * This simply copies all the fields (generic as well as device contract * specific) fields of the original. */ static struct ct_template * ctmpl_device_dup(struct ct_template *template) { ctmpl_device_t *new; ctmpl_device_t *old = template->ctmpl_data; char *buf; char *minor; new = kmem_zalloc(sizeof (ctmpl_device_t), KM_SLEEP); buf = kmem_alloc(MAXPATHLEN, KM_SLEEP); /* * copy generic fields. * ctmpl_copy returns with old template lock held */ ctmpl_copy(&new->ctd_ctmpl, template); new->ctd_ctmpl.ctmpl_data = new; new->ctd_aset = old->ctd_aset; new->ctd_minor = NULL; new->ctd_noneg = old->ctd_noneg; if (old->ctd_minor) { ASSERT(strlen(old->ctd_minor) + 1 <= MAXPATHLEN); bcopy(old->ctd_minor, buf, strlen(old->ctd_minor) + 1); } else { kmem_free(buf, MAXPATHLEN); buf = NULL; } mutex_exit(&template->ctmpl_lock); if (buf) { minor = i_ddi_strdup(buf, KM_SLEEP); kmem_free(buf, MAXPATHLEN); buf = NULL; } else { minor = NULL; } mutex_enter(&template->ctmpl_lock); if (minor) { new->ctd_minor = minor; } ASSERT(buf == NULL); return (&new->ctd_ctmpl); } /* * ctmpl_device_free * * The device contract template free entry point. Just * frees the template. */ static void ctmpl_device_free(struct ct_template *template) { ctmpl_device_t *dtmpl = template->ctmpl_data; if (dtmpl->ctd_minor) kmem_free(dtmpl->ctd_minor, strlen(dtmpl->ctd_minor) + 1); kmem_free(dtmpl, sizeof (ctmpl_device_t)); } /* * SAFE_EV is the set of events which a non-privileged process is * allowed to make critical. An unprivileged device contract owner has * no control over when a device changes state, so all device events * can be in the critical set. * * EXCESS tells us if "value", a critical event set, requires * additional privilege. For device contracts EXCESS currently * evaluates to 0. */ #define SAFE_EV (CT_DEV_ALLEVENT) #define EXCESS(value) ((value) & ~SAFE_EV) /* * ctmpl_device_set * * The device contract template set entry point. Sets various terms in the * template. The non-negotiable term can only be set if the process has * the {PRIV_SYS_DEVICES} privilege asserted in its effective set. */ static int ctmpl_device_set(struct ct_template *tmpl, ct_param_t *param, const cred_t *cr) { ctmpl_device_t *dtmpl = tmpl->ctmpl_data; int error; dev_info_t *dip; int spec_type; uint64_t param_value; char *str_value; ASSERT(MUTEX_HELD(&tmpl->ctmpl_lock)); if (param->ctpm_id == CTDP_MINOR) { str_value = (char *)param->ctpm_value; str_value[param->ctpm_size - 1] = '\0'; } else { param_value = *(uint64_t *)param->ctpm_value; } switch (param->ctpm_id) { case CTDP_ACCEPT: if (param_value & ~CT_DEV_ALLEVENT) return (EINVAL); if (param_value == 0) return (EINVAL); if (param_value == CT_DEV_ALLEVENT) return (EINVAL); dtmpl->ctd_aset = param_value; break; case CTDP_NONEG: if (param_value != CTDP_NONEG_SET && param_value != CTDP_NONEG_CLEAR) return (EINVAL); /* * only privileged processes can designate a contract * non-negotiatble. */ if (param_value == CTDP_NONEG_SET && (error = secpolicy_sys_devices(cr)) != 0) { return (error); } dtmpl->ctd_noneg = param_value; break; case CTDP_MINOR: if (*str_value != '/' || strncmp(str_value, "/devices/", strlen("/devices/")) == 0 || strstr(str_value, "../devices/") != NULL || strchr(str_value, ':') == NULL) { return (EINVAL); } spec_type = 0; dip = NULL; if (resolve_pathname(str_value, &dip, NULL, &spec_type) != 0) { return (ERANGE); } ddi_release_devi(dip); if (spec_type != S_IFCHR && spec_type != S_IFBLK) { return (EINVAL); } if (dtmpl->ctd_minor != NULL) { kmem_free(dtmpl->ctd_minor, strlen(dtmpl->ctd_minor) + 1); } dtmpl->ctd_minor = i_ddi_strdup(str_value, KM_SLEEP); break; case CTP_EV_CRITICAL: /* * Currently for device contracts, any event * may be added to the critical set. We retain the * following code however for future enhancements. */ if (EXCESS(param_value) && (error = secpolicy_contract_event(cr)) != 0) return (error); tmpl->ctmpl_ev_crit = param_value; break; default: return (EINVAL); } return (0); } /* * ctmpl_device_get * * The device contract template get entry point. Simply fetches and * returns the value of the requested term. */ static int ctmpl_device_get(struct ct_template *template, ct_param_t *param) { ctmpl_device_t *dtmpl = template->ctmpl_data; uint64_t *param_value = param->ctpm_value; ASSERT(MUTEX_HELD(&template->ctmpl_lock)); switch (param->ctpm_id) { case CTDP_ACCEPT: *param_value = dtmpl->ctd_aset; break; case CTDP_NONEG: *param_value = dtmpl->ctd_noneg; break; case CTDP_MINOR: if (dtmpl->ctd_minor) { param->ctpm_size = strlcpy((char *)param->ctpm_value, dtmpl->ctd_minor, param->ctpm_size); param->ctpm_size++; } else { return (ENOENT); } break; default: return (EINVAL); } return (0); } /* * Device contract type specific portion of creating a contract using * a specified template */ /*ARGSUSED*/ int ctmpl_device_create(ct_template_t *template, ctid_t *ctidp) { ctmpl_device_t *dtmpl; char *buf; dev_t dev; int spec_type; int error; cont_device_t *ctd; if (ctidp == NULL) return (EINVAL); buf = kmem_alloc(MAXPATHLEN, KM_SLEEP); dtmpl = template->ctmpl_data; mutex_enter(&template->ctmpl_lock); if (dtmpl->ctd_minor == NULL) { /* incomplete template */ mutex_exit(&template->ctmpl_lock); kmem_free(buf, MAXPATHLEN); return (EINVAL); } else { ASSERT(strlen(dtmpl->ctd_minor) < MAXPATHLEN); bcopy(dtmpl->ctd_minor, buf, strlen(dtmpl->ctd_minor) + 1); } mutex_exit(&template->ctmpl_lock); spec_type = 0; dev = NODEV; if (resolve_pathname(buf, NULL, &dev, &spec_type) != 0 || dev == NODEV || dev == DDI_DEV_T_ANY || dev == DDI_DEV_T_NONE || (spec_type != S_IFCHR && spec_type != S_IFBLK)) { CT_DEBUG((CE_WARN, "tmpl_create: failed to find device: %s", buf)); kmem_free(buf, MAXPATHLEN); return (ERANGE); } kmem_free(buf, MAXPATHLEN); ctd = contract_device_create(template->ctmpl_data, dev, spec_type, curproc, &error); if (ctd == NULL) { CT_DEBUG((CE_WARN, "Failed to create device contract for " "process (%d) with device (devt = %lu, spec_type = %s)", curproc->p_pid, dev, spec_type == S_IFCHR ? "S_IFCHR" : "S_IFBLK")); return (error); } mutex_enter(&ctd->cond_contract.ct_lock); *ctidp = ctd->cond_contract.ct_id; mutex_exit(&ctd->cond_contract.ct_lock); return (0); } /* * Device contract specific template entry points */ static ctmplops_t ctmpl_device_ops = { ctmpl_device_dup, /* ctop_dup */ ctmpl_device_free, /* ctop_free */ ctmpl_device_set, /* ctop_set */ ctmpl_device_get, /* ctop_get */ ctmpl_device_create, /* ctop_create */ CT_DEV_ALLEVENT /* all device events bitmask */ }; /* * Device contract implementation */ /* * contract_device_default * * The device contract default template entry point. Creates a * device contract template with a default A-set and no "noneg" , * with informative degrade events and critical offline events. * There is no default minor path. */ static ct_template_t * contract_device_default(void) { ctmpl_device_t *new; new = kmem_zalloc(sizeof (ctmpl_device_t), KM_SLEEP); ctmpl_init(&new->ctd_ctmpl, &ctmpl_device_ops, device_type, new); new->ctd_aset = CT_DEV_EV_ONLINE | CT_DEV_EV_DEGRADED; new->ctd_noneg = 0; new->ctd_ctmpl.ctmpl_ev_info = CT_DEV_EV_DEGRADED; new->ctd_ctmpl.ctmpl_ev_crit = CT_DEV_EV_OFFLINE; return (&new->ctd_ctmpl); } /* * contract_device_free * * Destroys the device contract specific portion of a contract and * frees the contract. */ static void contract_device_free(contract_t *ct) { cont_device_t *ctd = ct->ct_data; ASSERT(ctd->cond_minor); ASSERT(strlen(ctd->cond_minor) < MAXPATHLEN); kmem_free(ctd->cond_minor, strlen(ctd->cond_minor) + 1); ASSERT(ctd->cond_devt != DDI_DEV_T_ANY && ctd->cond_devt != DDI_DEV_T_NONE && ctd->cond_devt != NODEV); ASSERT(ctd->cond_spec == S_IFBLK || ctd->cond_spec == S_IFCHR); ASSERT(!(ctd->cond_aset & ~CT_DEV_ALLEVENT)); ASSERT(ctd->cond_noneg == 0 || ctd->cond_noneg == 1); ASSERT(!(ctd->cond_currev_type & ~CT_DEV_ALLEVENT)); ASSERT(!(ctd->cond_currev_ack & ~(CT_ACK | CT_NACK))); ASSERT((ctd->cond_currev_id > 0) ^ (ctd->cond_currev_type == 0)); ASSERT((ctd->cond_currev_id > 0) || (ctd->cond_currev_ack == 0)); ASSERT(!list_link_active(&ctd->cond_next)); kmem_free(ctd, sizeof (cont_device_t)); } /* * contract_device_abandon * * The device contract abandon entry point. */ static void contract_device_abandon(contract_t *ct) { ASSERT(MUTEX_HELD(&ct->ct_lock)); /* * device contracts cannot be inherited or orphaned. * Move the contract to the DEAD_STATE. It will be freed * once all references to it are gone. */ contract_destroy(ct); } /* * contract_device_destroy * * The device contract destroy entry point. * Called from contract_destroy() to do any type specific destroy. Note * that destroy is a misnomer - this does not free the contract, it only * moves it to the dead state. A contract is actually freed via * contract_rele() -> contract_dtor(), contop_free() */ static void contract_device_destroy(contract_t *ct) { cont_device_t *ctd = ct->ct_data; dev_info_t *dip = ctd->cond_dip; ASSERT(MUTEX_HELD(&ct->ct_lock)); if (dip == NULL) { /* * The dip has been removed, this is a dangling contract * Check that dip linkages are NULL */ ASSERT(!list_link_active(&ctd->cond_next)); CT_DEBUG((CE_NOTE, "contract_device_destroy: contract has no " "devinfo node. contract ctid : %d", ct->ct_id)); return; } /* * Need to have lock order: devi_ct_lock -> ct_count barrier -> ct_lock */ mutex_exit(&ct->ct_lock); /* * Waiting for the barrier to be released is strictly speaking not * necessary. But it simplifies the implementation of * contract_device_publish() by establishing the invariant that * device contracts cannot go away during negotiation. */ mutex_enter(&(DEVI(dip)->devi_ct_lock)); ct_barrier_wait_for_release(dip); mutex_enter(&ct->ct_lock); list_remove(&(DEVI(dip)->devi_ct), ctd); ctd->cond_dip = NULL; /* no longer linked to dip */ contract_rele(ct); /* remove hold for dip linkage */ mutex_exit(&ct->ct_lock); mutex_exit(&(DEVI(dip)->devi_ct_lock)); mutex_enter(&ct->ct_lock); } /* * contract_device_status * * The device contract status entry point. Called when level of "detail" * is either CTD_FIXED or CTD_ALL * */ static void contract_device_status(contract_t *ct, zone_t *zone, int detail, nvlist_t *nvl, void *status, model_t model) { cont_device_t *ctd = ct->ct_data; ASSERT(detail == CTD_FIXED || detail == CTD_ALL); mutex_enter(&ct->ct_lock); contract_status_common(ct, zone, status, model); /* * There's no need to hold the contract lock while accessing static * data like aset or noneg. But since we need the lock to access other * data like state, we hold it anyway. */ VERIFY(nvlist_add_uint32(nvl, CTDS_STATE, ctd->cond_state) == 0); VERIFY(nvlist_add_uint32(nvl, CTDS_ASET, ctd->cond_aset) == 0); VERIFY(nvlist_add_uint32(nvl, CTDS_NONEG, ctd->cond_noneg) == 0); if (detail == CTD_FIXED) { mutex_exit(&ct->ct_lock); return; } ASSERT(ctd->cond_minor); VERIFY(nvlist_add_string(nvl, CTDS_MINOR, ctd->cond_minor) == 0); mutex_exit(&ct->ct_lock); } /* * Converts a result integer into the corresponding string. Used for printing * messages */ static char * result_str(uint_t result) { switch (result) { case CT_ACK: return ("CT_ACK"); case CT_NACK: return ("CT_NACK"); case CT_NONE: return ("CT_NONE"); default: return ("UNKNOWN"); } } /* * Converts a device state integer constant into the corresponding string. * Used to print messages. */ static char * state_str(uint_t state) { switch (state) { case CT_DEV_EV_ONLINE: return ("ONLINE"); case CT_DEV_EV_DEGRADED: return ("DEGRADED"); case CT_DEV_EV_OFFLINE: return ("OFFLINE"); default: return ("UNKNOWN"); } } /* * Routine that determines if a particular CT_DEV_EV_? event corresponds to a * synchronous state change or not. */ static int is_sync_neg(uint_t old, uint_t new) { int i; ASSERT(old & CT_DEV_ALLEVENT); ASSERT(new & CT_DEV_ALLEVENT); if (old == new) { CT_DEBUG((CE_WARN, "is_sync_neg: transition to same state: %s", state_str(new))); return (-2); } for (i = 0; ct_dev_negtable[i].st_new != 0; i++) { if (old == ct_dev_negtable[i].st_old && new == ct_dev_negtable[i].st_new) { return (ct_dev_negtable[i].st_neg); } } CT_DEBUG((CE_WARN, "is_sync_neg: Unsupported state transition: " "old = %s -> new = %s", state_str(old), state_str(new))); return (-1); } /* * Used to cleanup cached dv_nodes so that when a device is released by * a contract holder, its devinfo node can be successfully detached. */ static int contract_device_dvclean(dev_info_t *dip) { char *devnm; dev_info_t *pdip; int error; ASSERT(dip); /* pdip can be NULL if we have contracts against the root dip */ pdip = ddi_get_parent(dip); if (pdip && DEVI_BUSY_OWNED(pdip) || !pdip && DEVI_BUSY_OWNED(dip)) { char *path; path = kmem_alloc(MAXPATHLEN, KM_SLEEP); (void) ddi_pathname(dip, path); CT_DEBUG((CE_WARN, "ct_dv_clean: Parent node is busy owned, " "device=%s", path)); kmem_free(path, MAXPATHLEN); return (EDEADLOCK); } if (pdip) { devnm = kmem_alloc(MAXNAMELEN + 1, KM_SLEEP); (void) ddi_deviname(dip, devnm); error = devfs_clean(pdip, devnm + 1, DV_CLEAN_FORCE); kmem_free(devnm, MAXNAMELEN + 1); } else { error = devfs_clean(dip, NULL, DV_CLEAN_FORCE); } return (error); } /* * Endpoint of a ct_ctl_ack() or ct_ctl_nack() call from userland. * Results in the ACK or NACK being recorded on the dip for one particular * contract. The device contracts framework evaluates the ACK/NACKs for all * contracts against a device to determine if a particular device state change * should be allowed. */ static int contract_device_ack_nack(contract_t *ct, uint_t evtype, uint64_t evid, uint_t cmd) { cont_device_t *ctd = ct->ct_data; dev_info_t *dip; ctid_t ctid; int error; ctid = ct->ct_id; CT_DEBUG((CE_NOTE, "ack_nack: entered: ctid %d", ctid)); mutex_enter(&ct->ct_lock); CT_DEBUG((CE_NOTE, "ack_nack: contract lock acquired: %d", ctid)); dip = ctd->cond_dip; ASSERT(ctd->cond_minor); ASSERT(strlen(ctd->cond_minor) < MAXPATHLEN); /* * Negotiation only if new state is not in A-set */ ASSERT(!(ctd->cond_aset & evtype)); /* * Negotiation only if transition is synchronous */ ASSERT(is_sync_neg(ctd->cond_state, evtype)); /* * We shouldn't be negotiating if the "noneg" flag is set */ ASSERT(!ctd->cond_noneg); if (dip) ndi_hold_devi(dip); mutex_exit(&ct->ct_lock); /* * dv_clean only if !NACK and offline state change */ if (cmd != CT_NACK && evtype == CT_DEV_EV_OFFLINE && dip) { CT_DEBUG((CE_NOTE, "ack_nack: dv_clean: %d", ctid)); error = contract_device_dvclean(dip); if (error != 0) { CT_DEBUG((CE_NOTE, "ack_nack: dv_clean: failed: %d", ctid)); ddi_release_devi(dip); } } mutex_enter(&ct->ct_lock); if (dip) ddi_release_devi(dip); if (dip == NULL) { if (ctd->cond_currev_id != evid) { CT_DEBUG((CE_WARN, "%sACK for non-current event " "(type=%s, id=%llu) on removed device", cmd == CT_NACK ? "N" : "", state_str(evtype), (unsigned long long)evid)); CT_DEBUG((CE_NOTE, "ack_nack: error: ESRCH, ctid: %d", ctid)); } else { ASSERT(ctd->cond_currev_type == evtype); CT_DEBUG((CE_WARN, "contract_ack: no such device: " "ctid: %d", ctid)); } error = (ct->ct_state == CTS_DEAD) ? ESRCH : ((cmd == CT_NACK) ? ETIMEDOUT : 0); mutex_exit(&ct->ct_lock); return (error); } /* * Must follow lock order: devi_ct_lock -> ct_count barrier - >ct_lock */ mutex_exit(&ct->ct_lock); mutex_enter(&DEVI(dip)->devi_ct_lock); mutex_enter(&ct->ct_lock); if (ctd->cond_currev_id != evid) { char *buf; mutex_exit(&ct->ct_lock); mutex_exit(&DEVI(dip)->devi_ct_lock); ndi_hold_devi(dip); buf = kmem_alloc(MAXPATHLEN, KM_SLEEP); (void) ddi_pathname(dip, buf); ddi_release_devi(dip); CT_DEBUG((CE_WARN, "%sACK for non-current event" "(type=%s, id=%llu) on device %s", cmd == CT_NACK ? "N" : "", state_str(evtype), (unsigned long long)evid, buf)); kmem_free(buf, MAXPATHLEN); CT_DEBUG((CE_NOTE, "ack_nack: error: %d, ctid: %d", cmd == CT_NACK ? ETIMEDOUT : 0, ctid)); return (cmd == CT_ACK ? 0 : ETIMEDOUT); } ASSERT(ctd->cond_currev_type == evtype); ASSERT(cmd == CT_ACK || cmd == CT_NACK); CT_DEBUG((CE_NOTE, "ack_nack: setting %sACK for ctid: %d", cmd == CT_NACK ? "N" : "", ctid)); ctd->cond_currev_ack = cmd; mutex_exit(&ct->ct_lock); ct_barrier_decr(dip); mutex_exit(&DEVI(dip)->devi_ct_lock); CT_DEBUG((CE_NOTE, "ack_nack: normal exit: ctid: %d", ctid)); return (0); } /* * Invoked when a userland contract holder approves (i.e. ACKs) a state change */ static int contract_device_ack(contract_t *ct, uint_t evtype, uint64_t evid) { return (contract_device_ack_nack(ct, evtype, evid, CT_ACK)); } /* * Invoked when a userland contract holder blocks (i.e. NACKs) a state change */ static int contract_device_nack(contract_t *ct, uint_t evtype, uint64_t evid) { return (contract_device_ack_nack(ct, evtype, evid, CT_NACK)); } /* * Creates a new contract synchronously with the breaking of an existing * contract. Currently not supported. */ /*ARGSUSED*/ static int contract_device_newct(contract_t *ct) { return (ENOTSUP); } /* * Core device contract implementation entry points */ static contops_t contract_device_ops = { contract_device_free, /* contop_free */ contract_device_abandon, /* contop_abandon */ contract_device_destroy, /* contop_destroy */ contract_device_status, /* contop_status */ contract_device_ack, /* contop_ack */ contract_device_nack, /* contop_nack */ contract_qack_notsup, /* contop_qack */ contract_device_newct /* contop_newct */ }; /* * contract_device_init * * Initializes the device contract type. */ void contract_device_init(void) { device_type = contract_type_init(CTT_DEVICE, "device", &contract_device_ops, contract_device_default); } /* * contract_device_create * * create a device contract given template "tmpl" and the "owner" process. * May fail and return NULL if project.max-contracts would have been exceeded. * * Common device contract creation routine called for both open-time and * non-open time device contract creation */ static cont_device_t * contract_device_create(ctmpl_device_t *dtmpl, dev_t dev, int spec_type, proc_t *owner, int *errorp) { cont_device_t *ctd; char *minor; char *path; dev_info_t *dip; ASSERT(dtmpl != NULL); ASSERT(dev != NODEV && dev != DDI_DEV_T_ANY && dev != DDI_DEV_T_NONE); ASSERT(spec_type == S_IFCHR || spec_type == S_IFBLK); ASSERT(errorp); *errorp = 0; path = kmem_alloc(MAXPATHLEN, KM_SLEEP); mutex_enter(&dtmpl->ctd_ctmpl.ctmpl_lock); ASSERT(strlen(dtmpl->ctd_minor) < MAXPATHLEN); bcopy(dtmpl->ctd_minor, path, strlen(dtmpl->ctd_minor) + 1); mutex_exit(&dtmpl->ctd_ctmpl.ctmpl_lock); dip = e_ddi_hold_devi_by_path(path, 0); if (dip == NULL) { cmn_err(CE_WARN, "contract_create: Cannot find devinfo node " "for device path (%s)", path); kmem_free(path, MAXPATHLEN); *errorp = ERANGE; return (NULL); } /* * Lock out any parallel contract negotiations */ mutex_enter(&(DEVI(dip)->devi_ct_lock)); ct_barrier_acquire(dip); mutex_exit(&(DEVI(dip)->devi_ct_lock)); minor = i_ddi_strdup(path, KM_SLEEP); kmem_free(path, MAXPATHLEN); (void) contract_type_pbundle(device_type, owner); ctd = kmem_zalloc(sizeof (cont_device_t), KM_SLEEP); /* * Only we hold a refernce to this contract. Safe to access * the fields without a ct_lock */ ctd->cond_minor = minor; /* * It is safe to set the dip pointer in the contract * as the contract will always be destroyed before the dip * is released */ ctd->cond_dip = dip; ctd->cond_devt = dev; ctd->cond_spec = spec_type; /* * Since we are able to lookup the device, it is either * online or degraded */ ctd->cond_state = DEVI_IS_DEVICE_DEGRADED(dip) ? CT_DEV_EV_DEGRADED : CT_DEV_EV_ONLINE; mutex_enter(&dtmpl->ctd_ctmpl.ctmpl_lock); ctd->cond_aset = dtmpl->ctd_aset; ctd->cond_noneg = dtmpl->ctd_noneg; /* * contract_ctor() initailizes the common portion of a contract * contract_dtor() destroys the common portion of a contract */ if (contract_ctor(&ctd->cond_contract, device_type, &dtmpl->ctd_ctmpl, ctd, 0, owner, B_TRUE)) { mutex_exit(&dtmpl->ctd_ctmpl.ctmpl_lock); /* * contract_device_free() destroys the type specific * portion of a contract and frees the contract. * The "minor" path and "cred" is a part of the type specific * portion of the contract and will be freed by * contract_device_free() */ contract_device_free(&ctd->cond_contract); /* release barrier */ mutex_enter(&(DEVI(dip)->devi_ct_lock)); ct_barrier_release(dip); mutex_exit(&(DEVI(dip)->devi_ct_lock)); ddi_release_devi(dip); *errorp = EAGAIN; return (NULL); } mutex_exit(&dtmpl->ctd_ctmpl.ctmpl_lock); mutex_enter(&ctd->cond_contract.ct_lock); ctd->cond_contract.ct_ntime.ctm_total = CT_DEV_ACKTIME; ctd->cond_contract.ct_qtime.ctm_total = CT_DEV_ACKTIME; ctd->cond_contract.ct_ntime.ctm_start = -1; ctd->cond_contract.ct_qtime.ctm_start = -1; mutex_exit(&ctd->cond_contract.ct_lock); /* * Insert device contract into list hanging off the dip * Bump up the ref-count on the contract to reflect this */ contract_hold(&ctd->cond_contract); mutex_enter(&(DEVI(dip)->devi_ct_lock)); list_insert_tail(&(DEVI(dip)->devi_ct), ctd); /* release barrier */ ct_barrier_release(dip); mutex_exit(&(DEVI(dip)->devi_ct_lock)); ddi_release_devi(dip); return (ctd); } /* * Called when a device is successfully opened to create an open-time contract * i.e. synchronously with a device open. */ int contract_device_open(dev_t dev, int spec_type, contract_t **ctpp) { ctmpl_device_t *dtmpl; ct_template_t *tmpl; cont_device_t *ctd; char *path; klwp_t *lwp; int error; if (ctpp) *ctpp = NULL; /* * Check if we are in user-context i.e. if we have an lwp */ lwp = ttolwp(curthread); if (lwp == NULL) { CT_DEBUG((CE_NOTE, "contract_open: Not user-context")); return (0); } tmpl = ctmpl_dup(lwp->lwp_ct_active[device_type->ct_type_index]); if (tmpl == NULL) { return (0); } dtmpl = tmpl->ctmpl_data; /* * If the user set a minor path in the template before an open, * ignore it. We use the minor path of the actual minor opened. */ mutex_enter(&tmpl->ctmpl_lock); if (dtmpl->ctd_minor != NULL) { CT_DEBUG((CE_NOTE, "contract_device_open(): Process %d: " "ignoring device minor path in active template: %s", curproc->p_pid, dtmpl->ctd_minor)); /* * This is a copy of the actual activated template. * Safe to make changes such as freeing the minor * path in the template. */ kmem_free(dtmpl->ctd_minor, strlen(dtmpl->ctd_minor) + 1); dtmpl->ctd_minor = NULL; } mutex_exit(&tmpl->ctmpl_lock); path = kmem_alloc(MAXPATHLEN, KM_SLEEP); if (ddi_dev_pathname(dev, spec_type, path) != DDI_SUCCESS) { CT_DEBUG((CE_NOTE, "contract_device_open(): Failed to derive " "minor path from dev_t,spec {%lu, %d} for process (%d)", dev, spec_type, curproc->p_pid)); ctmpl_free(tmpl); kmem_free(path, MAXPATHLEN); return (1); } mutex_enter(&tmpl->ctmpl_lock); ASSERT(dtmpl->ctd_minor == NULL); dtmpl->ctd_minor = path; mutex_exit(&tmpl->ctmpl_lock); ctd = contract_device_create(dtmpl, dev, spec_type, curproc, &error); mutex_enter(&tmpl->ctmpl_lock); ASSERT(dtmpl->ctd_minor); dtmpl->ctd_minor = NULL; mutex_exit(&tmpl->ctmpl_lock); ctmpl_free(tmpl); kmem_free(path, MAXPATHLEN); if (ctd == NULL) { cmn_err(CE_NOTE, "contract_device_open(): Failed to " "create device contract for process (%d) holding " "device (devt = %lu, spec_type = %d)", curproc->p_pid, dev, spec_type); return (1); } if (ctpp) { mutex_enter(&ctd->cond_contract.ct_lock); *ctpp = &ctd->cond_contract; mutex_exit(&ctd->cond_contract.ct_lock); } return (0); } /* * Called during contract negotiation by the device contract framework to wait * for ACKs or NACKs from contract holders. If all responses are not received * before a specified timeout, this routine times out. */ static uint_t wait_for_acks(dev_info_t *dip, dev_t dev, int spec_type, uint_t evtype) { cont_device_t *ctd; int timed_out = 0; int result = CT_NONE; int ack; char *f = "wait_for_acks"; ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); ASSERT(dip); ASSERT(evtype & CT_DEV_ALLEVENT); ASSERT(dev != NODEV && dev != DDI_DEV_T_NONE); ASSERT((dev == DDI_DEV_T_ANY && spec_type == 0) || (spec_type == S_IFBLK || spec_type == S_IFCHR)); CT_DEBUG((CE_NOTE, "%s: entered: dip: %p", f, (void *)dip)); if (ct_barrier_wait_for_empty(dip, CT_DEV_ACKTIME) == -1) { /* * some contract owner(s) didn't respond in time */ CT_DEBUG((CE_NOTE, "%s: timed out: %p", f, (void *)dip)); timed_out = 1; } ack = 0; for (ctd = list_head(&(DEVI(dip)->devi_ct)); ctd != NULL; ctd = list_next(&(DEVI(dip)->devi_ct), ctd)) { mutex_enter(&ctd->cond_contract.ct_lock); ASSERT(ctd->cond_dip == dip); if (dev != DDI_DEV_T_ANY && dev != ctd->cond_devt) { mutex_exit(&ctd->cond_contract.ct_lock); continue; } if (dev != DDI_DEV_T_ANY && spec_type != ctd->cond_spec) { mutex_exit(&ctd->cond_contract.ct_lock); continue; } /* skip if non-negotiable contract */ if (ctd->cond_noneg) { mutex_exit(&ctd->cond_contract.ct_lock); continue; } ASSERT(ctd->cond_currev_type == evtype); if (ctd->cond_currev_ack == CT_NACK) { CT_DEBUG((CE_NOTE, "%s: found a NACK,result = NACK: %p", f, (void *)dip)); mutex_exit(&ctd->cond_contract.ct_lock); return (CT_NACK); } else if (ctd->cond_currev_ack == CT_ACK) { ack = 1; CT_DEBUG((CE_NOTE, "%s: found a ACK: %p", f, (void *)dip)); } mutex_exit(&ctd->cond_contract.ct_lock); } if (ack) { result = CT_ACK; CT_DEBUG((CE_NOTE, "%s: result = ACK, dip=%p", f, (void *)dip)); } else if (timed_out) { result = CT_NONE; CT_DEBUG((CE_NOTE, "%s: result = NONE (timed-out), dip=%p", f, (void *)dip)); } else { CT_DEBUG((CE_NOTE, "%s: result = NONE, dip=%p", f, (void *)dip)); } return (result); } /* * Determines the current state of a device (i.e a devinfo node */ static int get_state(dev_info_t *dip) { if (DEVI_IS_DEVICE_OFFLINE(dip) || DEVI_IS_DEVICE_DOWN(dip)) return (CT_DEV_EV_OFFLINE); else if (DEVI_IS_DEVICE_DEGRADED(dip)) return (CT_DEV_EV_DEGRADED); else return (CT_DEV_EV_ONLINE); } /* * Sets the current state of a device in a device contract */ static void set_cond_state(dev_info_t *dip) { uint_t state = get_state(dip); cont_device_t *ctd; /* verify that barrier is held */ ASSERT(ct_barrier_held(dip)); for (ctd = list_head(&(DEVI(dip)->devi_ct)); ctd != NULL; ctd = list_next(&(DEVI(dip)->devi_ct), ctd)) { mutex_enter(&ctd->cond_contract.ct_lock); ASSERT(ctd->cond_dip == dip); ctd->cond_state = state; mutex_exit(&ctd->cond_contract.ct_lock); } } /* * Core routine called by event-specific routines when an event occurs. * Determines if an event should be be published, and if it is to be * published, whether a negotiation should take place. Also implements * NEGEND events which publish the final disposition of an event after * negotiations are complete. * * When an event occurs on a minor node, this routine walks the list of * contracts hanging off a devinfo node and for each contract on the affected * dip, evaluates the following cases * * a. an event that is synchronous, breaks the contract and NONEG not set * - bumps up the outstanding negotiation counts on the dip * - marks the dip as undergoing negotiation (devi_ct_neg) * - event of type CTE_NEG is published * b. an event that is synchronous, breaks the contract and NONEG is set * - sets the final result to CT_NACK, event is blocked * - does not publish an event * c. event is asynchronous and breaks the contract * - publishes a critical event irrespect of whether the NONEG * flag is set, since the contract will be broken and contract * owner needs to be informed. * d. No contract breakage but the owner has subscribed to the event * - publishes the event irrespective of the NONEG event as the * owner has explicitly subscribed to the event. * e. NEGEND event * - publishes a critical event. Should only be doing this if * if NONEG is not set. * f. all other events * - Since a contract is not broken and this event has not been * subscribed to, this event does not need to be published for * for this contract. * * Once an event is published, what happens next depends on the type of * event: * * a. NEGEND event * - cleanup all state associated with the preceding negotiation * and return CT_ACK to the caller of contract_device_publish() * b. NACKed event * - One or more contracts had the NONEG term, so the event was * blocked. Return CT_NACK to the caller. * c. Negotiated event * - Call wait_for_acks() to wait for responses from contract * holders. The end result is either CT_ACK (event is permitted), * CT_NACK (event is blocked) or CT_NONE (no contract owner) * responded. This result is returned back to the caller. * d. All other events * - If the event was asynchronous (i.e. not negotiated) or * a contract was not broken return CT_ACK to the caller. */ static uint_t contract_device_publish(dev_info_t *dip, dev_t dev, int spec_type, uint_t evtype, nvlist_t *tnvl) { cont_device_t *ctd; uint_t result = CT_NONE; uint64_t evid = 0; uint64_t nevid = 0; char *path = NULL; int negend; int match; int sync = 0; contract_t *ct; ct_kevent_t *event; nvlist_t *nvl; int broken = 0; ASSERT(dip); ASSERT(dev != NODEV && dev != DDI_DEV_T_NONE); ASSERT((dev == DDI_DEV_T_ANY && spec_type == 0) || (spec_type == S_IFBLK || spec_type == S_IFCHR)); ASSERT(evtype == 0 || (evtype & CT_DEV_ALLEVENT)); /* Is this a synchronous state change ? */ if (evtype != CT_EV_NEGEND) { sync = is_sync_neg(get_state(dip), evtype); /* NOP if unsupported transition */ if (sync == -2 || sync == -1) { DEVI(dip)->devi_flags |= DEVI_CT_NOP; result = (sync == -2) ? CT_ACK : CT_NONE; goto out; } CT_DEBUG((CE_NOTE, "publish: is%s sync state change", sync ? "" : " not")); } else if (DEVI(dip)->devi_flags & DEVI_CT_NOP) { DEVI(dip)->devi_flags &= ~DEVI_CT_NOP; result = CT_ACK; goto out; } path = kmem_alloc(MAXPATHLEN, KM_SLEEP); (void) ddi_pathname(dip, path); mutex_enter(&(DEVI(dip)->devi_ct_lock)); /* * Negotiation end - set the state of the device in the contract */ if (evtype == CT_EV_NEGEND) { CT_DEBUG((CE_NOTE, "publish: negend: setting cond state")); set_cond_state(dip); } /* * If this device didn't go through negotiation, don't publish * a NEGEND event - simply release the barrier to allow other * device events in. */ negend = 0; if (evtype == CT_EV_NEGEND && !DEVI(dip)->devi_ct_neg) { CT_DEBUG((CE_NOTE, "publish: no negend reqd. release barrier")); ct_barrier_release(dip); mutex_exit(&(DEVI(dip)->devi_ct_lock)); result = CT_ACK; goto out; } else if (evtype == CT_EV_NEGEND) { /* * There are negotiated contract breakages that * need a NEGEND event */ ASSERT(ct_barrier_held(dip)); negend = 1; CT_DEBUG((CE_NOTE, "publish: setting negend flag")); } else { /* * This is a new event, not a NEGEND event. Wait for previous * contract events to complete. */ ct_barrier_acquire(dip); } match = 0; for (ctd = list_head(&(DEVI(dip)->devi_ct)); ctd != NULL; ctd = list_next(&(DEVI(dip)->devi_ct), ctd)) { ctid_t ctid; size_t len = strlen(path); mutex_enter(&ctd->cond_contract.ct_lock); ASSERT(ctd->cond_dip == dip); ASSERT(ctd->cond_minor); ASSERT(strncmp(ctd->cond_minor, path, len) == 0 && ctd->cond_minor[len] == ':'); if (dev != DDI_DEV_T_ANY && dev != ctd->cond_devt) { mutex_exit(&ctd->cond_contract.ct_lock); continue; } if (dev != DDI_DEV_T_ANY && spec_type != ctd->cond_spec) { mutex_exit(&ctd->cond_contract.ct_lock); continue; } /* We have a matching contract */ match = 1; ctid = ctd->cond_contract.ct_id; CT_DEBUG((CE_NOTE, "publish: found matching contract: %d", ctid)); /* * There are 4 possible cases * 1. A contract is broken (dev not in acceptable state) and * the state change is synchronous - start negotiation * by sending a CTE_NEG critical event. * 2. A contract is broken and the state change is * asynchronous - just send a critical event and * break the contract. * 3. Contract is not broken, but consumer has subscribed * to the event as a critical or informative event * - just send the appropriate event * 4. contract waiting for negend event - just send the critical * NEGEND event. */ broken = 0; if (!negend && !(evtype & ctd->cond_aset)) { broken = 1; CT_DEBUG((CE_NOTE, "publish: Contract broken: %d", ctid)); } /* * Don't send event if * - contract is not broken AND * - contract holder has not subscribed to this event AND * - contract not waiting for a NEGEND event */ if (!broken && !EVSENDP(ctd, evtype) && !ctd->cond_neg) { CT_DEBUG((CE_NOTE, "contract_device_publish(): " "contract (%d): no publish reqd: event %d", ctd->cond_contract.ct_id, evtype)); mutex_exit(&ctd->cond_contract.ct_lock); continue; } /* * Note: need to kmem_zalloc() the event so mutexes are * initialized automatically */ ct = &ctd->cond_contract; event = kmem_zalloc(sizeof (ct_kevent_t), KM_SLEEP); event->cte_type = evtype; if (broken && sync) { CT_DEBUG((CE_NOTE, "publish: broken + sync: " "ctid: %d", ctid)); ASSERT(!negend); ASSERT(ctd->cond_currev_id == 0); ASSERT(ctd->cond_currev_type == 0); ASSERT(ctd->cond_currev_ack == 0); ASSERT(ctd->cond_neg == 0); if (ctd->cond_noneg) { /* Nothing to publish. Event has been blocked */ CT_DEBUG((CE_NOTE, "publish: sync and noneg:" "not publishing blocked ev: ctid: %d", ctid)); result = CT_NACK; kmem_free(event, sizeof (ct_kevent_t)); mutex_exit(&ctd->cond_contract.ct_lock); continue; } event->cte_flags = CTE_NEG; /* critical neg. event */ ctd->cond_currev_type = event->cte_type; ct_barrier_incr(dip); DEVI(dip)->devi_ct_neg = 1; /* waiting for negend */ ctd->cond_neg = 1; } else if (broken && !sync) { CT_DEBUG((CE_NOTE, "publish: broken + async: ctid: %d", ctid)); ASSERT(!negend); ASSERT(ctd->cond_currev_id == 0); ASSERT(ctd->cond_currev_type == 0); ASSERT(ctd->cond_currev_ack == 0); ASSERT(ctd->cond_neg == 0); event->cte_flags = 0; /* critical event */ } else if (EVSENDP(ctd, event->cte_type)) { CT_DEBUG((CE_NOTE, "publish: event suscrib: ctid: %d", ctid)); ASSERT(!negend); ASSERT(ctd->cond_currev_id == 0); ASSERT(ctd->cond_currev_type == 0); ASSERT(ctd->cond_currev_ack == 0); ASSERT(ctd->cond_neg == 0); event->cte_flags = EVINFOP(ctd, event->cte_type) ? CTE_INFO : 0; } else if (ctd->cond_neg) { CT_DEBUG((CE_NOTE, "publish: NEGEND: ctid: %d", ctid)); ASSERT(negend); ASSERT(ctd->cond_noneg == 0); nevid = ctd->cond_contract.ct_nevent ? ctd->cond_contract.ct_nevent->cte_id : 0; ASSERT(ctd->cond_currev_id == nevid); event->cte_flags = 0; /* NEGEND is always critical */ ctd->cond_currev_id = 0; ctd->cond_currev_type = 0; ctd->cond_currev_ack = 0; ctd->cond_neg = 0; } else { CT_DEBUG((CE_NOTE, "publish: not publishing event for " "ctid: %d, evtype: %d", ctd->cond_contract.ct_id, event->cte_type)); ASSERT(!negend); ASSERT(ctd->cond_currev_id == 0); ASSERT(ctd->cond_currev_type == 0); ASSERT(ctd->cond_currev_ack == 0); ASSERT(ctd->cond_neg == 0); kmem_free(event, sizeof (ct_kevent_t)); mutex_exit(&ctd->cond_contract.ct_lock); continue; } nvl = NULL; if (tnvl) { VERIFY(nvlist_dup(tnvl, &nvl, 0) == 0); if (negend) { int32_t newct = 0; ASSERT(ctd->cond_noneg == 0); VERIFY(nvlist_add_uint64(nvl, CTS_NEVID, nevid) == 0); VERIFY(nvlist_lookup_int32(nvl, CTS_NEWCT, &newct) == 0); VERIFY(nvlist_add_int32(nvl, CTS_NEWCT, newct == 1 ? 0 : ctd->cond_contract.ct_id) == 0); CT_DEBUG((CE_NOTE, "publish: negend: ctid: %d " "CTS_NEVID: %llu, CTS_NEWCT: %s", ctid, (unsigned long long)nevid, newct ? "success" : "failure")); } } if (ctd->cond_neg) { ASSERT(ctd->cond_contract.ct_ntime.ctm_start == -1); ASSERT(ctd->cond_contract.ct_qtime.ctm_start == -1); ctd->cond_contract.ct_ntime.ctm_start = ddi_get_lbolt(); ctd->cond_contract.ct_qtime.ctm_start = ctd->cond_contract.ct_ntime.ctm_start; } /* * by holding the dip's devi_ct_lock we ensure that * all ACK/NACKs are held up until we have finished * publishing to all contracts. */ mutex_exit(&ctd->cond_contract.ct_lock); evid = cte_publish_all(ct, event, nvl, NULL); mutex_enter(&ctd->cond_contract.ct_lock); if (ctd->cond_neg) { ASSERT(!negend); ASSERT(broken); ASSERT(sync); ASSERT(!ctd->cond_noneg); CT_DEBUG((CE_NOTE, "publish: sync break, setting evid" ": %d", ctid)); ctd->cond_currev_id = evid; } else if (negend) { ctd->cond_contract.ct_ntime.ctm_start = -1; ctd->cond_contract.ct_qtime.ctm_start = -1; } mutex_exit(&ctd->cond_contract.ct_lock); } /* * If "negend" set counter back to initial state (-1) so that * other events can be published. Also clear the negotiation flag * on dip. * * 0 .. n are used for counting. * -1 indicates counter is available for use. */ if (negend) { /* * devi_ct_count not necessarily 0. We may have * timed out in which case, count will be non-zero. */ ct_barrier_release(dip); DEVI(dip)->devi_ct_neg = 0; CT_DEBUG((CE_NOTE, "publish: negend: reset dip state: dip=%p", (void *)dip)); } else if (DEVI(dip)->devi_ct_neg) { ASSERT(match); ASSERT(!ct_barrier_empty(dip)); CT_DEBUG((CE_NOTE, "publish: sync count=%d, dip=%p", DEVI(dip)->devi_ct_count, (void *)dip)); } else { /* * for non-negotiated events or subscribed events or no * matching contracts */ ASSERT(ct_barrier_empty(dip)); ASSERT(DEVI(dip)->devi_ct_neg == 0); CT_DEBUG((CE_NOTE, "publish: async/non-nego/subscrib/no-match: " "dip=%p", (void *)dip)); /* * only this function when called from contract_device_negend() * can reset the counter to READY state i.e. -1. This function * is so called for every event whether a NEGEND event is needed * or not, but the negend event is only published if the event * whose end they signal is a negotiated event for the contract. */ } if (!match) { /* No matching contracts */ CT_DEBUG((CE_NOTE, "publish: No matching contract")); result = CT_NONE; } else if (result == CT_NACK) { /* a non-negotiable contract exists and this is a neg. event */ CT_DEBUG((CE_NOTE, "publish: found 1 or more NONEG contract")); (void) wait_for_acks(dip, dev, spec_type, evtype); } else if (DEVI(dip)->devi_ct_neg) { /* one or more contracts going through negotations */ CT_DEBUG((CE_NOTE, "publish: sync contract: waiting")); result = wait_for_acks(dip, dev, spec_type, evtype); } else { /* no negotiated contracts or no broken contracts or NEGEND */ CT_DEBUG((CE_NOTE, "publish: async/no-break/negend")); result = CT_ACK; } /* * Release the lock only now so that the only point where we * drop the lock is in wait_for_acks(). This is so that we don't * miss cv_signal/cv_broadcast from contract holders */ CT_DEBUG((CE_NOTE, "publish: dropping devi_ct_lock")); mutex_exit(&(DEVI(dip)->devi_ct_lock)); out: if (tnvl) nvlist_free(tnvl); if (path) kmem_free(path, MAXPATHLEN); CT_DEBUG((CE_NOTE, "publish: result = %s", result_str(result))); return (result); } /* * contract_device_offline * * Event publishing routine called by I/O framework when a device is offlined. */ ct_ack_t contract_device_offline(dev_info_t *dip, dev_t dev, int spec_type) { nvlist_t *nvl; uint_t result; uint_t evtype; VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0); evtype = CT_DEV_EV_OFFLINE; result = contract_device_publish(dip, dev, spec_type, evtype, nvl); /* * If a contract offline is NACKED, the framework expects us to call * NEGEND ourselves, since we know the final result */ if (result == CT_NACK) { contract_device_negend(dip, dev, spec_type, CT_EV_FAILURE); } return (result); } /* * contract_device_degrade * * Event publishing routine called by I/O framework when a device * moves to degrade state. */ /*ARGSUSED*/ void contract_device_degrade(dev_info_t *dip, dev_t dev, int spec_type) { nvlist_t *nvl; uint_t evtype; VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0); evtype = CT_DEV_EV_DEGRADED; (void) contract_device_publish(dip, dev, spec_type, evtype, nvl); } /* * contract_device_undegrade * * Event publishing routine called by I/O framework when a device * moves from degraded state to online state. */ /*ARGSUSED*/ void contract_device_undegrade(dev_info_t *dip, dev_t dev, int spec_type) { nvlist_t *nvl; uint_t evtype; VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0); evtype = CT_DEV_EV_ONLINE; (void) contract_device_publish(dip, dev, spec_type, evtype, nvl); } /* * For all contracts which have undergone a negotiation (because the device * moved out of the acceptable state for that contract and the state * change is synchronous i.e. requires negotiation) this routine publishes * a CT_EV_NEGEND event with the final disposition of the event. * * This event is always a critical event. */ void contract_device_negend(dev_info_t *dip, dev_t dev, int spec_type, int result) { nvlist_t *nvl; uint_t evtype; ASSERT(result == CT_EV_SUCCESS || result == CT_EV_FAILURE); CT_DEBUG((CE_NOTE, "contract_device_negend(): entered: result: %d, " "dip: %p", result, (void *)dip)); VERIFY(nvlist_alloc(&nvl, NV_UNIQUE_NAME, KM_SLEEP) == 0); VERIFY(nvlist_add_int32(nvl, CTS_NEWCT, result == CT_EV_SUCCESS ? 1 : 0) == 0); evtype = CT_EV_NEGEND; (void) contract_device_publish(dip, dev, spec_type, evtype, nvl); CT_DEBUG((CE_NOTE, "contract_device_negend(): exit dip: %p", (void *)dip)); } /* * Wrapper routine called by other subsystems (such as LDI) to start * negotiations when a synchronous device state change occurs. * Returns CT_ACK or CT_NACK. */ ct_ack_t contract_device_negotiate(dev_info_t *dip, dev_t dev, int spec_type, uint_t evtype) { int result; ASSERT(dip); ASSERT(dev != NODEV); ASSERT(dev != DDI_DEV_T_ANY); ASSERT(dev != DDI_DEV_T_NONE); ASSERT(spec_type == S_IFBLK || spec_type == S_IFCHR); switch (evtype) { case CT_DEV_EV_OFFLINE: result = contract_device_offline(dip, dev, spec_type); break; default: cmn_err(CE_PANIC, "contract_device_negotiate(): Negotiation " "not supported: event (%d) for dev_t (%lu) and spec (%d), " "dip (%p)", evtype, dev, spec_type, (void *)dip); result = CT_NACK; break; } return (result); } /* * A wrapper routine called by other subsystems (such as the LDI) to * finalize event processing for a state change event. For synchronous * state changes, this publishes NEGEND events. For asynchronous i.e. * non-negotiable events this publishes the event. */ void contract_device_finalize(dev_info_t *dip, dev_t dev, int spec_type, uint_t evtype, int ct_result) { ASSERT(dip); ASSERT(dev != NODEV); ASSERT(dev != DDI_DEV_T_ANY); ASSERT(dev != DDI_DEV_T_NONE); ASSERT(spec_type == S_IFBLK || spec_type == S_IFCHR); switch (evtype) { case CT_DEV_EV_OFFLINE: contract_device_negend(dip, dev, spec_type, ct_result); break; case CT_DEV_EV_DEGRADED: contract_device_degrade(dip, dev, spec_type); contract_device_negend(dip, dev, spec_type, ct_result); break; case CT_DEV_EV_ONLINE: contract_device_undegrade(dip, dev, spec_type); contract_device_negend(dip, dev, spec_type, ct_result); break; default: cmn_err(CE_PANIC, "contract_device_finalize(): Unsupported " "event (%d) for dev_t (%lu) and spec (%d), dip (%p)", evtype, dev, spec_type, (void *)dip); break; } } /* * Called by I/O framework when a devinfo node is freed to remove the * association between a devinfo node and its contracts. */ void contract_device_remove_dip(dev_info_t *dip) { cont_device_t *ctd; cont_device_t *next; contract_t *ct; mutex_enter(&(DEVI(dip)->devi_ct_lock)); ct_barrier_wait_for_release(dip); for (ctd = list_head(&(DEVI(dip)->devi_ct)); ctd != NULL; ctd = next) { next = list_next(&(DEVI(dip)->devi_ct), ctd); list_remove(&(DEVI(dip)->devi_ct), ctd); ct = &ctd->cond_contract; /* * Unlink the dip associated with this contract */ mutex_enter(&ct->ct_lock); ASSERT(ctd->cond_dip == dip); ctd->cond_dip = NULL; /* no longer linked to dip */ contract_rele(ct); /* remove hold for dip linkage */ CT_DEBUG((CE_NOTE, "ct: remove_dip: removed dip from contract: " "ctid: %d", ct->ct_id)); mutex_exit(&ct->ct_lock); } ASSERT(list_is_empty(&(DEVI(dip)->devi_ct))); mutex_exit(&(DEVI(dip)->devi_ct_lock)); } /* * Barrier related routines */ static void ct_barrier_acquire(dev_info_t *dip) { ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); CT_DEBUG((CE_NOTE, "ct_barrier_acquire: waiting for barrier")); while (DEVI(dip)->devi_ct_count != -1) cv_wait(&(DEVI(dip)->devi_ct_cv), &(DEVI(dip)->devi_ct_lock)); DEVI(dip)->devi_ct_count = 0; CT_DEBUG((CE_NOTE, "ct_barrier_acquire: thread owns barrier")); } static void ct_barrier_release(dev_info_t *dip) { ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); ASSERT(DEVI(dip)->devi_ct_count != -1); DEVI(dip)->devi_ct_count = -1; cv_broadcast(&(DEVI(dip)->devi_ct_cv)); CT_DEBUG((CE_NOTE, "ct_barrier_release: Released barrier")); } static int ct_barrier_held(dev_info_t *dip) { ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); return (DEVI(dip)->devi_ct_count != -1); } static int ct_barrier_empty(dev_info_t *dip) { ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); ASSERT(DEVI(dip)->devi_ct_count != -1); return (DEVI(dip)->devi_ct_count == 0); } static void ct_barrier_wait_for_release(dev_info_t *dip) { ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); while (DEVI(dip)->devi_ct_count != -1) cv_wait(&(DEVI(dip)->devi_ct_cv), &(DEVI(dip)->devi_ct_lock)); } static void ct_barrier_decr(dev_info_t *dip) { CT_DEBUG((CE_NOTE, "barrier_decr: ct_count before decr: %d", DEVI(dip)->devi_ct_count)); ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); ASSERT(DEVI(dip)->devi_ct_count > 0); DEVI(dip)->devi_ct_count--; if (DEVI(dip)->devi_ct_count == 0) { cv_broadcast(&DEVI(dip)->devi_ct_cv); CT_DEBUG((CE_NOTE, "barrier_decr: cv_broadcast")); } } static void ct_barrier_incr(dev_info_t *dip) { ASSERT(ct_barrier_held(dip)); DEVI(dip)->devi_ct_count++; } static int ct_barrier_wait_for_empty(dev_info_t *dip, int secs) { clock_t abstime; ASSERT(MUTEX_HELD(&(DEVI(dip)->devi_ct_lock))); abstime = ddi_get_lbolt() + drv_usectohz(secs*1000000); while (DEVI(dip)->devi_ct_count) { if (cv_timedwait(&(DEVI(dip)->devi_ct_cv), &(DEVI(dip)->devi_ct_lock), abstime) == -1) { return (-1); } } return (0); }