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Diffstat (limited to 'drivers/staging/lustre/lustre/include/lustre_nrs.h')
| -rw-r--r-- | drivers/staging/lustre/lustre/include/lustre_nrs.h | 718 |
1 files changed, 0 insertions, 718 deletions
diff --git a/drivers/staging/lustre/lustre/include/lustre_nrs.h b/drivers/staging/lustre/lustre/include/lustre_nrs.h deleted file mode 100644 index ffa7317da35b..000000000000 --- a/drivers/staging/lustre/lustre/include/lustre_nrs.h +++ /dev/null @@ -1,718 +0,0 @@ -// SPDX-License-Identifier: GPL-2.0 -/* - * GPL HEADER START - * - * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. - * - * This program is free software; you can redistribute it and/or modify - * it under the terms of the GNU General Public License version 2 only, - * as published by the Free Software Foundation. - * - * This program is distributed in the hope that it will be useful, - * but WITHOUT ANY WARRANTY; without even the implied warranty of - * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the - * GNU General Public License version 2 for more details. - * - * You should have received a copy of the GNU General Public License - * version 2 along with this program; If not, see - * http://www.gnu.org/licenses/gpl-2.0.html - * - * GPL HEADER END - */ -/* - * Copyright (c) 2014, Intel Corporation. - * - * Copyright 2012 Xyratex Technology Limited - */ -/* - * - * Network Request Scheduler (NRS) - * - */ - -#ifndef _LUSTRE_NRS_H -#define _LUSTRE_NRS_H - -/** - * \defgroup nrs Network Request Scheduler - * @{ - */ -struct ptlrpc_nrs_policy; -struct ptlrpc_nrs_resource; -struct ptlrpc_nrs_request; - -/** - * NRS control operations. - * - * These are common for all policies. - */ -enum ptlrpc_nrs_ctl { - /** - * Not a valid opcode. - */ - PTLRPC_NRS_CTL_INVALID, - /** - * Activate the policy. - */ - PTLRPC_NRS_CTL_START, - /** - * Reserved for multiple primary policies, which may be a possibility - * in the future. - */ - PTLRPC_NRS_CTL_STOP, - /** - * Policies can start using opcodes from this value and onwards for - * their own purposes; the assigned value itself is arbitrary. - */ - PTLRPC_NRS_CTL_1ST_POL_SPEC = 0x20, -}; - -/** - * NRS policy operations. - * - * These determine the behaviour of a policy, and are called in response to - * NRS core events. - */ -struct ptlrpc_nrs_pol_ops { - /** - * Called during policy registration; this operation is optional. - * - * \param[in,out] policy The policy being initialized - */ - int (*op_policy_init)(struct ptlrpc_nrs_policy *policy); - /** - * Called during policy unregistration; this operation is optional. - * - * \param[in,out] policy The policy being unregistered/finalized - */ - void (*op_policy_fini)(struct ptlrpc_nrs_policy *policy); - /** - * Called when activating a policy via lprocfs; policies allocate and - * initialize their resources here; this operation is optional. - * - * \param[in,out] policy The policy being started - * - * \see nrs_policy_start_locked() - */ - int (*op_policy_start)(struct ptlrpc_nrs_policy *policy); - /** - * Called when deactivating a policy via lprocfs; policies deallocate - * their resources here; this operation is optional - * - * \param[in,out] policy The policy being stopped - * - * \see nrs_policy_stop0() - */ - void (*op_policy_stop)(struct ptlrpc_nrs_policy *policy); - /** - * Used for policy-specific operations; i.e. not generic ones like - * \e PTLRPC_NRS_CTL_START and \e PTLRPC_NRS_CTL_GET_INFO; analogous - * to an ioctl; this operation is optional. - * - * \param[in,out] policy The policy carrying out operation \a opc - * \param[in] opc The command operation being carried out - * \param[in,out] arg An generic buffer for communication between the - * user and the control operation - * - * \retval -ve error - * \retval 0 success - * - * \see ptlrpc_nrs_policy_control() - */ - int (*op_policy_ctl)(struct ptlrpc_nrs_policy *policy, - enum ptlrpc_nrs_ctl opc, void *arg); - - /** - * Called when obtaining references to the resources of the resource - * hierarchy for a request that has arrived for handling at the PTLRPC - * service. Policies should return -ve for requests they do not wish - * to handle. This operation is mandatory. - * - * \param[in,out] policy The policy we're getting resources for. - * \param[in,out] nrq The request we are getting resources for. - * \param[in] parent The parent resource of the resource being - * requested; set to NULL if none. - * \param[out] resp The resource is to be returned here; the - * fallback policy in an NRS head should - * \e always return a non-NULL pointer value. - * \param[in] moving_req When set, signifies that this is an attempt - * to obtain resources for a request being moved - * to the high-priority NRS head by - * ldlm_lock_reorder_req(). - * This implies two things: - * 1. We are under obd_export::exp_rpc_lock and - * so should not sleep. - * 2. We should not perform non-idempotent or can - * skip performing idempotent operations that - * were carried out when resources were first - * taken for the request when it was initialized - * in ptlrpc_nrs_req_initialize(). - * - * \retval 0, +ve The level of the returned resource in the resource - * hierarchy; currently only 0 (for a non-leaf resource) - * and 1 (for a leaf resource) are supported by the - * framework. - * \retval -ve error - * - * \see ptlrpc_nrs_req_initialize() - * \see ptlrpc_nrs_hpreq_add_nolock() - * \see ptlrpc_nrs_req_hp_move() - */ - int (*op_res_get)(struct ptlrpc_nrs_policy *policy, - struct ptlrpc_nrs_request *nrq, - const struct ptlrpc_nrs_resource *parent, - struct ptlrpc_nrs_resource **resp, - bool moving_req); - /** - * Called when releasing references taken for resources in the resource - * hierarchy for the request; this operation is optional. - * - * \param[in,out] policy The policy the resource belongs to - * \param[in] res The resource to be freed - * - * \see ptlrpc_nrs_req_finalize() - * \see ptlrpc_nrs_hpreq_add_nolock() - * \see ptlrpc_nrs_req_hp_move() - */ - void (*op_res_put)(struct ptlrpc_nrs_policy *policy, - const struct ptlrpc_nrs_resource *res); - - /** - * Obtains a request for handling from the policy, and optionally - * removes the request from the policy; this operation is mandatory. - * - * \param[in,out] policy The policy to poll - * \param[in] peek When set, signifies that we just want to - * examine the request, and not handle it, so the - * request is not removed from the policy. - * \param[in] force When set, it will force a policy to return a - * request if it has one queued. - * - * \retval NULL No request available for handling - * \retval valid-pointer The request polled for handling - * - * \see ptlrpc_nrs_req_get_nolock() - */ - struct ptlrpc_nrs_request * - (*op_req_get)(struct ptlrpc_nrs_policy *policy, bool peek, - bool force); - /** - * Called when attempting to add a request to a policy for later - * handling; this operation is mandatory. - * - * \param[in,out] policy The policy on which to enqueue \a nrq - * \param[in,out] nrq The request to enqueue - * - * \retval 0 success - * \retval != 0 error - * - * \see ptlrpc_nrs_req_add_nolock() - */ - int (*op_req_enqueue)(struct ptlrpc_nrs_policy *policy, - struct ptlrpc_nrs_request *nrq); - /** - * Removes a request from the policy's set of pending requests. Normally - * called after a request has been polled successfully from the policy - * for handling; this operation is mandatory. - * - * \param[in,out] policy The policy the request \a nrq belongs to - * \param[in,out] nrq The request to dequeue - * - * \see ptlrpc_nrs_req_del_nolock() - */ - void (*op_req_dequeue)(struct ptlrpc_nrs_policy *policy, - struct ptlrpc_nrs_request *nrq); - /** - * Called after the request being carried out. Could be used for - * job/resource control; this operation is optional. - * - * \param[in,out] policy The policy which is stopping to handle request - * \a nrq - * \param[in,out] nrq The request - * - * \pre assert_spin_locked(&svcpt->scp_req_lock) - * - * \see ptlrpc_nrs_req_stop_nolock() - */ - void (*op_req_stop)(struct ptlrpc_nrs_policy *policy, - struct ptlrpc_nrs_request *nrq); - /** - * Registers the policy's lprocfs interface with a PTLRPC service. - * - * \param[in] svc The service - * - * \retval 0 success - * \retval != 0 error - */ - int (*op_lprocfs_init)(struct ptlrpc_service *svc); - /** - * Unegisters the policy's lprocfs interface with a PTLRPC service. - * - * In cases of failed policy registration in - * \e ptlrpc_nrs_policy_register(), this function may be called for a - * service which has not registered the policy successfully, so - * implementations of this method should make sure their operations are - * safe in such cases. - * - * \param[in] svc The service - */ - void (*op_lprocfs_fini)(struct ptlrpc_service *svc); -}; - -/** - * Policy flags - */ -enum nrs_policy_flags { - /** - * Fallback policy, use this flag only on a single supported policy per - * service. The flag cannot be used on policies that use - * \e PTLRPC_NRS_FL_REG_EXTERN - */ - PTLRPC_NRS_FL_FALLBACK = BIT(0), - /** - * Start policy immediately after registering. - */ - PTLRPC_NRS_FL_REG_START = BIT(1), - /** - * This is a policy registering from a module different to the one NRS - * core ships in (currently ptlrpc). - */ - PTLRPC_NRS_FL_REG_EXTERN = BIT(2), -}; - -/** - * NRS queue type. - * - * Denotes whether an NRS instance is for handling normal or high-priority - * RPCs, or whether an operation pertains to one or both of the NRS instances - * in a service. - */ -enum ptlrpc_nrs_queue_type { - PTLRPC_NRS_QUEUE_REG = BIT(0), - PTLRPC_NRS_QUEUE_HP = BIT(1), - PTLRPC_NRS_QUEUE_BOTH = (PTLRPC_NRS_QUEUE_REG | PTLRPC_NRS_QUEUE_HP) -}; - -/** - * NRS head - * - * A PTLRPC service has at least one NRS head instance for handling normal - * priority RPCs, and may optionally have a second NRS head instance for - * handling high-priority RPCs. Each NRS head maintains a list of available - * policies, of which one and only one policy is acting as the fallback policy, - * and optionally a different policy may be acting as the primary policy. For - * all RPCs handled by this NRS head instance, NRS core will first attempt to - * enqueue the RPC using the primary policy (if any). The fallback policy is - * used in the following cases: - * - when there was no primary policy in the - * ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED state at the time the request - * was initialized. - * - when the primary policy that was at the - * ptlrpc_nrs_pol_state::PTLRPC_NRS_POL_STATE_STARTED state at the time the - * RPC was initialized, denoted it did not wish, or for some other reason was - * not able to handle the request, by returning a non-valid NRS resource - * reference. - * - when the primary policy that was at the - * ptlrpc_nrs_pol_state::PTLRPC_NRS_POL_STATE_STARTED state at the time the - * RPC was initialized, fails later during the request enqueueing stage. - * - * \see nrs_resource_get_safe() - * \see nrs_request_enqueue() - */ -struct ptlrpc_nrs { - spinlock_t nrs_lock; - /** XXX Possibly replace svcpt->scp_req_lock with another lock here. */ - /** - * List of registered policies - */ - struct list_head nrs_policy_list; - /** - * List of policies with queued requests. Policies that have any - * outstanding requests are queued here, and this list is queried - * in a round-robin manner from NRS core when obtaining a request - * for handling. This ensures that requests from policies that at some - * point transition away from the - * ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED state are drained. - */ - struct list_head nrs_policy_queued; - /** - * Service partition for this NRS head - */ - struct ptlrpc_service_part *nrs_svcpt; - /** - * Primary policy, which is the preferred policy for handling RPCs - */ - struct ptlrpc_nrs_policy *nrs_policy_primary; - /** - * Fallback policy, which is the backup policy for handling RPCs - */ - struct ptlrpc_nrs_policy *nrs_policy_fallback; - /** - * This NRS head handles either HP or regular requests - */ - enum ptlrpc_nrs_queue_type nrs_queue_type; - /** - * # queued requests from all policies in this NRS head - */ - unsigned long nrs_req_queued; - /** - * # scheduled requests from all policies in this NRS head - */ - unsigned long nrs_req_started; - /** - * # policies on this NRS - */ - unsigned int nrs_num_pols; - /** - * This NRS head is in progress of starting a policy - */ - unsigned int nrs_policy_starting:1; - /** - * In progress of shutting down the whole NRS head; used during - * unregistration - */ - unsigned int nrs_stopping:1; - /** - * NRS policy is throttling request - */ - unsigned int nrs_throttling:1; -}; - -#define NRS_POL_NAME_MAX 16 -#define NRS_POL_ARG_MAX 16 - -struct ptlrpc_nrs_pol_desc; - -/** - * Service compatibility predicate; this determines whether a policy is adequate - * for handling RPCs of a particular PTLRPC service. - * - * XXX:This should give the same result during policy registration and - * unregistration, and for all partitions of a service; so the result should not - * depend on temporal service or other properties, that may influence the - * result. - */ -typedef bool (*nrs_pol_desc_compat_t)(const struct ptlrpc_service *svc, - const struct ptlrpc_nrs_pol_desc *desc); - -struct ptlrpc_nrs_pol_conf { - /** - * Human-readable policy name - */ - char nc_name[NRS_POL_NAME_MAX]; - /** - * NRS operations for this policy - */ - const struct ptlrpc_nrs_pol_ops *nc_ops; - /** - * Service compatibility predicate - */ - nrs_pol_desc_compat_t nc_compat; - /** - * Set for policies that support a single ptlrpc service, i.e. ones that - * have \a pd_compat set to nrs_policy_compat_one(). The variable value - * depicts the name of the single service that such policies are - * compatible with. - */ - const char *nc_compat_svc_name; - /** - * Owner module for this policy descriptor; policies registering from a - * different module to the one the NRS framework is held within - * (currently ptlrpc), should set this field to THIS_MODULE. - */ - struct module *nc_owner; - /** - * Policy registration flags; a bitmask of \e nrs_policy_flags - */ - unsigned int nc_flags; -}; - -/** - * NRS policy registering descriptor - * - * Is used to hold a description of a policy that can be passed to NRS core in - * order to register the policy with NRS heads in different PTLRPC services. - */ -struct ptlrpc_nrs_pol_desc { - /** - * Human-readable policy name - */ - char pd_name[NRS_POL_NAME_MAX]; - /** - * Link into nrs_core::nrs_policies - */ - struct list_head pd_list; - /** - * NRS operations for this policy - */ - const struct ptlrpc_nrs_pol_ops *pd_ops; - /** - * Service compatibility predicate - */ - nrs_pol_desc_compat_t pd_compat; - /** - * Set for policies that are compatible with only one PTLRPC service. - * - * \see ptlrpc_nrs_pol_conf::nc_compat_svc_name - */ - const char *pd_compat_svc_name; - /** - * Owner module for this policy descriptor. - * - * We need to hold a reference to the module whenever we might make use - * of any of the module's contents, i.e. - * - If one or more instances of the policy are at a state where they - * might be handling a request, i.e. - * ptlrpc_nrs_pol_state::NRS_POL_STATE_STARTED or - * ptlrpc_nrs_pol_state::NRS_POL_STATE_STOPPING as we will have to - * call into the policy's ptlrpc_nrs_pol_ops() handlers. A reference - * is taken on the module when - * \e ptlrpc_nrs_pol_desc::pd_refs becomes 1, and released when it - * becomes 0, so that we hold only one reference to the module maximum - * at any time. - * - * We do not need to hold a reference to the module, even though we - * might use code and data from the module, in the following cases: - * - During external policy registration, because this should happen in - * the module's init() function, in which case the module is safe from - * removal because a reference is being held on the module by the - * kernel, and iirc kmod (and I guess module-init-tools also) will - * serialize any racing processes properly anyway. - * - During external policy unregistration, because this should happen - * in a module's exit() function, and any attempts to start a policy - * instance would need to take a reference on the module, and this is - * not possible once we have reached the point where the exit() - * handler is called. - * - During service registration and unregistration, as service setup - * and cleanup, and policy registration, unregistration and policy - * instance starting, are serialized by \e nrs_core::nrs_mutex, so - * as long as users adhere to the convention of registering policies - * in init() and unregistering them in module exit() functions, there - * should not be a race between these operations. - * - During any policy-specific lprocfs operations, because a reference - * is held by the kernel on a proc entry that has been entered by a - * syscall, so as long as proc entries are removed during - * unregistration time, then unregistration and lprocfs operations - * will be properly serialized. - */ - struct module *pd_owner; - /** - * Bitmask of \e nrs_policy_flags - */ - unsigned int pd_flags; - /** - * # of references on this descriptor - */ - atomic_t pd_refs; -}; - -/** - * NRS policy state - * - * Policies transition from one state to the other during their lifetime - */ -enum ptlrpc_nrs_pol_state { - /** - * Not a valid policy state. - */ - NRS_POL_STATE_INVALID, - /** - * Policies are at this state either at the start of their life, or - * transition here when the user selects a different policy to act - * as the primary one. - */ - NRS_POL_STATE_STOPPED, - /** - * Policy is progress of stopping - */ - NRS_POL_STATE_STOPPING, - /** - * Policy is in progress of starting - */ - NRS_POL_STATE_STARTING, - /** - * A policy is in this state in two cases: - * - it is the fallback policy, which is always in this state. - * - it has been activated by the user; i.e. it is the primary policy, - */ - NRS_POL_STATE_STARTED, -}; - -/** - * NRS policy information - * - * Used for obtaining information for the status of a policy via lprocfs - */ -struct ptlrpc_nrs_pol_info { - /** - * Policy name - */ - char pi_name[NRS_POL_NAME_MAX]; - /** - * Policy argument - */ - char pi_arg[NRS_POL_ARG_MAX]; - /** - * Current policy state - */ - enum ptlrpc_nrs_pol_state pi_state; - /** - * # RPCs enqueued for later dispatching by the policy - */ - long pi_req_queued; - /** - * # RPCs started for dispatch by the policy - */ - long pi_req_started; - /** - * Is this a fallback policy? - */ - unsigned pi_fallback:1; -}; - -/** - * NRS policy - * - * There is one instance of this for each policy in each NRS head of each - * PTLRPC service partition. - */ -struct ptlrpc_nrs_policy { - /** - * Linkage into the NRS head's list of policies, - * ptlrpc_nrs:nrs_policy_list - */ - struct list_head pol_list; - /** - * Linkage into the NRS head's list of policies with enqueued - * requests ptlrpc_nrs:nrs_policy_queued - */ - struct list_head pol_list_queued; - /** - * Current state of this policy - */ - enum ptlrpc_nrs_pol_state pol_state; - /** - * Bitmask of nrs_policy_flags - */ - unsigned int pol_flags; - /** - * # RPCs enqueued for later dispatching by the policy - */ - long pol_req_queued; - /** - * # RPCs started for dispatch by the policy - */ - long pol_req_started; - /** - * Usage Reference count taken on the policy instance - */ - long pol_ref; - /** - * Human-readable policy argument - */ - char pol_arg[NRS_POL_ARG_MAX]; - /** - * The NRS head this policy has been created at - */ - struct ptlrpc_nrs *pol_nrs; - /** - * Private policy data; varies by policy type - */ - void *pol_private; - /** - * Policy descriptor for this policy instance. - */ - struct ptlrpc_nrs_pol_desc *pol_desc; -}; - -/** - * NRS resource - * - * Resources are embedded into two types of NRS entities: - * - Inside NRS policies, in the policy's private data in - * ptlrpc_nrs_policy::pol_private - * - In objects that act as prime-level scheduling entities in different NRS - * policies; e.g. on a policy that performs round robin or similar order - * scheduling across client NIDs, there would be one NRS resource per unique - * client NID. On a policy which performs round robin scheduling across - * backend filesystem objects, there would be one resource associated with - * each of the backend filesystem objects partaking in the scheduling - * performed by the policy. - * - * NRS resources share a parent-child relationship, in which resources embedded - * in policy instances are the parent entities, with all scheduling entities - * a policy schedules across being the children, thus forming a simple resource - * hierarchy. This hierarchy may be extended with one or more levels in the - * future if the ability to have more than one primary policy is added. - * - * Upon request initialization, references to the then active NRS policies are - * taken and used to later handle the dispatching of the request with one of - * these policies. - * - * \see nrs_resource_get_safe() - * \see ptlrpc_nrs_req_add() - */ -struct ptlrpc_nrs_resource { - /** - * This NRS resource's parent; is NULL for resources embedded in NRS - * policy instances; i.e. those are top-level ones. - */ - struct ptlrpc_nrs_resource *res_parent; - /** - * The policy associated with this resource. - */ - struct ptlrpc_nrs_policy *res_policy; -}; - -enum { - NRS_RES_FALLBACK, - NRS_RES_PRIMARY, - NRS_RES_MAX -}; - -#include <lustre_nrs_fifo.h> - -/** - * NRS request - * - * Instances of this object exist embedded within ptlrpc_request; the main - * purpose of this object is to hold references to the request's resources - * for the lifetime of the request, and to hold properties that policies use - * use for determining the request's scheduling priority. - **/ -struct ptlrpc_nrs_request { - /** - * The request's resource hierarchy. - */ - struct ptlrpc_nrs_resource *nr_res_ptrs[NRS_RES_MAX]; - /** - * Index into ptlrpc_nrs_request::nr_res_ptrs of the resource of the - * policy that was used to enqueue the request. - * - * \see nrs_request_enqueue() - */ - unsigned int nr_res_idx; - unsigned int nr_initialized:1; - unsigned int nr_enqueued:1; - unsigned int nr_started:1; - unsigned int nr_finalized:1; - - /** - * Policy-specific fields, used for determining a request's scheduling - * priority, and other supporting functionality. - */ - union { - /** - * Fields for the FIFO policy - */ - struct nrs_fifo_req fifo; - } nr_u; - /** - * Externally-registering policies may want to use this to allocate - * their own request properties. - */ - void *ext; -}; - -/** @} nrs */ -#endif |