staging: lustre: ptlrpc: Move NRS structures out of lustre_net.h (d0365097) · Commits · e / devices / android_kernel_oneplus_sm7250

drivers/staging/lustre/lustre/include/lustre_net.h

+1 −711

Original line number	Diff line number	Diff line
		@@ -515,717 +515,7 @@ struct lu_env;

		struct ldlm_lock;

		/**
		* \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,
		};

		/**
		* ORR policy operations
		*/
		enum nrs_ctl_orr {
		NRS_CTL_ORR_RD_QUANTUM = PTLRPC_NRS_CTL_1ST_POL_SPEC,
		NRS_CTL_ORR_WR_QUANTUM,
		NRS_CTL_ORR_RD_OFF_TYPE,
		NRS_CTL_ORR_WR_OFF_TYPE,
		NRS_CTL_ORR_RD_SUPP_REQ,
		NRS_CTL_ORR_WR_SUPP_REQ,
		};

		/**
		* 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()
		*/
		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()
		*/
		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
		*/
		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 = (1 << 0),
		/**
		* Start policy immediately after registering.
		*/
		PTLRPC_NRS_FL_REG_START = (1 << 1),
		/**
		* This is a policy registering from a module different to the one NRS
		* core ships in (currently ptlrpc).
		*/
		PTLRPC_NRS_FL_REG_EXTERN = (1 << 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 = (1 << 0),
		PTLRPC_NRS_QUEUE_HP = (1 << 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 nrs_num_pols;
		/**
		* This NRS head is in progress of starting a policy
		*/
		unsigned nrs_policy_starting:1;
		/**
		* In progress of shutting down the whole NRS head; used during
		* unregistration
		*/
		unsigned nrs_stopping:1;
		};

		#define NRS_POL_NAME_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 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 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];
		/**
		* 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 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;
		/**
		* 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
		};

		/* \name fifo
		*
		* FIFO policy
		*
		* This policy is a logical wrapper around previous, non-NRS functionality.
		* It dispatches RPCs in the same order as they arrive from the network. This
		* policy is currently used as the fallback policy, and the only enabled policy
		* on all NRS heads of all PTLRPC service partitions.
		* @{
		*/

		/**
		* Private data structure for the FIFO policy
		*/
		struct nrs_fifo_head {
		/**
		* Resource object for policy instance.
		*/
		struct ptlrpc_nrs_resource fh_res;
		/**
		* List of queued requests.
		*/
		struct list_head fh_list;
		/**
		* For debugging purposes.
		*/
		__u64 fh_sequence;
		};

		struct nrs_fifo_req {
		struct list_head fr_list;
		__u64 fr_sequence;
		};

		/** @} fifo */

		/**
		* 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 nr_res_idx;
		unsigned nr_initialized:1;
		unsigned nr_enqueued:1;
		unsigned nr_started:1;
		unsigned 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 */
		#include "lustre_nrs.h"

		/**
		* Basic request prioritization operations structure.

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		/*
		* 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) First-in First-out (FIFO) policy
		*
		*/

		#ifndef _LUSTRE_NRS_FIFO_H
		#define _LUSTRE_NRS_FIFO_H

		/* \name fifo
		*
		* FIFO policy
		*
		* This policy is a logical wrapper around previous, non-NRS functionality.
		* It dispatches RPCs in the same order as they arrive from the network. This
		* policy is currently used as the fallback policy, and the only enabled policy
		* on all NRS heads of all PTLRPC service partitions.
		* @{
		*/

		/**
		* Private data structure for the FIFO policy
		*/
		struct nrs_fifo_head {
		/**
		* Resource object for policy instance.
		*/
		struct ptlrpc_nrs_resource fh_res;
		/**
		* List of queued requests.
		*/
		struct list_head fh_list;
		/**
		* For debugging purposes.
		*/
		__u64 fh_sequence;
		};

		struct nrs_fifo_req {
		struct list_head fr_list;
		__u64 fr_sequence;
		};

		/** @} fifo */
		#endif