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

/*
 * 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 (a copy is included
 * in the LICENSE file that accompanied this code).
 *
 * 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) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
 * Use is subject to license terms.
 *
 * Copyright (c) 2010, 2015, Intel Corporation.
 */
/*
 * This file is part of Lustre, http://www.lustre.org/
 * Lustre is a trademark of Sun Microsystems, Inc.
 */
/** \defgroup PtlRPC Portal RPC and networking module.
 *
 * PortalRPC is the layer used by rest of lustre code to achieve network
 * communications: establish connections with corresponding export and import
 * states, listen for a service, send and receive RPCs.
 * PortalRPC also includes base recovery framework: packet resending and
 * replaying, reconnections, pinger.
 *
 * PortalRPC utilizes LNet as its transport layer.
 *
 * @{
 */

#ifndef _LUSTRE_NET_H
#define _LUSTRE_NET_H

/** \defgroup net net
 *
 * @{
 */

#include <linux/uio.h>
#include <linux/libcfs/libcfs.h>
#include <uapi/linux/lnet/nidstr.h>
#include <linux/lnet/api.h>
#include <uapi/linux/lustre/lustre_idl.h>
#include <lustre_errno.h>
#include <lustre_ha.h>
#include <lustre_sec.h>
#include <lustre_import.h>
#include <lprocfs_status.h>
#include <lu_object.h>
#include <lustre_req_layout.h>

#include <obd_support.h>
#include <uapi/linux/lustre/lustre_ver.h>

/* MD flags we _always_ use */
#define PTLRPC_MD_OPTIONS  0

/**
 * log2 max # of bulk operations in one request: 2=4MB/RPC, 5=32MB/RPC, ...
 * In order for the client and server to properly negotiate the maximum
 * possible transfer size, PTLRPC_BULK_OPS_COUNT must be a power-of-two
 * value.  The client is free to limit the actual RPC size for any bulk
 * transfer via cl_max_pages_per_rpc to some non-power-of-two value.
 * NOTE: This is limited to 16 (=64GB RPCs) by IOOBJ_MAX_BRW_BITS.
 */
#define PTLRPC_BULK_OPS_BITS	4
#if PTLRPC_BULK_OPS_BITS > 16
#error "More than 65536 BRW RPCs not allowed by IOOBJ_MAX_BRW_BITS."
#endif
#define PTLRPC_BULK_OPS_COUNT	(1U << PTLRPC_BULK_OPS_BITS)
/**
 * PTLRPC_BULK_OPS_MASK is for the convenience of the client only, and
 * should not be used on the server at all.  Otherwise, it imposes a
 * protocol limitation on the maximum RPC size that can be used by any
 * RPC sent to that server in the future.  Instead, the server should
 * use the negotiated per-client ocd_brw_size to determine the bulk
 * RPC count.
 */
#define PTLRPC_BULK_OPS_MASK	(~((__u64)PTLRPC_BULK_OPS_COUNT - 1))

/**
 * Define maxima for bulk I/O.
 *
 * A single PTLRPC BRW request is sent via up to PTLRPC_BULK_OPS_COUNT
 * of LNET_MTU sized RDMA transfers.  Clients and servers negotiate the
 * currently supported maximum between peers at connect via ocd_brw_size.
 */
#define PTLRPC_MAX_BRW_BITS	(LNET_MTU_BITS + PTLRPC_BULK_OPS_BITS)
#define PTLRPC_MAX_BRW_SIZE	(1 << PTLRPC_MAX_BRW_BITS)
#define PTLRPC_MAX_BRW_PAGES	(PTLRPC_MAX_BRW_SIZE >> PAGE_SHIFT)

#define ONE_MB_BRW_SIZE		(1 << LNET_MTU_BITS)
#define MD_MAX_BRW_SIZE		(1 << LNET_MTU_BITS)
#define MD_MAX_BRW_PAGES	(MD_MAX_BRW_SIZE >> PAGE_SHIFT)
#define DT_MAX_BRW_SIZE		PTLRPC_MAX_BRW_SIZE
#define DT_MAX_BRW_PAGES	(DT_MAX_BRW_SIZE >> PAGE_SHIFT)
#define OFD_MAX_BRW_SIZE	(1 << LNET_MTU_BITS)

/* When PAGE_SIZE is a constant, we can check our arithmetic here with cpp! */
# if ((PTLRPC_MAX_BRW_PAGES & (PTLRPC_MAX_BRW_PAGES - 1)) != 0)
#  error "PTLRPC_MAX_BRW_PAGES isn't a power of two"
# endif
# if (PTLRPC_MAX_BRW_SIZE != (PTLRPC_MAX_BRW_PAGES * PAGE_SIZE))
#  error "PTLRPC_MAX_BRW_SIZE isn't PTLRPC_MAX_BRW_PAGES * PAGE_SIZE"
# endif
# if (PTLRPC_MAX_BRW_SIZE > LNET_MTU * PTLRPC_BULK_OPS_COUNT)
#  error "PTLRPC_MAX_BRW_SIZE too big"
# endif
# if (PTLRPC_MAX_BRW_PAGES > LNET_MAX_IOV * PTLRPC_BULK_OPS_COUNT)
#  error "PTLRPC_MAX_BRW_PAGES too big"
# endif

#define PTLRPC_NTHRS_INIT	2

/**
 * Buffer Constants
 *
 * Constants determine how memory is used to buffer incoming service requests.
 *
 * ?_NBUFS	      # buffers to allocate when growing the pool
 * ?_BUFSIZE	    # bytes in a single request buffer
 * ?_MAXREQSIZE	 # maximum request service will receive
 *
 * When fewer than ?_NBUFS/2 buffers are posted for receive, another chunk
 * of ?_NBUFS is added to the pool.
 *
 * Messages larger than ?_MAXREQSIZE are dropped.  Request buffers are
 * considered full when less than ?_MAXREQSIZE is left in them.
 */
/**
 * Thread Constants
 *
 * Constants determine how threads are created for ptlrpc service.
 *
 * ?_NTHRS_INIT		# threads to create for each service partition on
 *			  initializing. If it's non-affinity service and
 *			  there is only one partition, it's the overall #
 *			  threads for the service while initializing.
 * ?_NTHRS_BASE		# threads should be created at least for each
 *			  ptlrpc partition to keep the service healthy.
 *			  It's the low-water mark of threads upper-limit
 *			  for each partition.
 * ?_THR_FACTOR	 # threads can be added on threads upper-limit for
 *			  each CPU core. This factor is only for reference,
 *			  we might decrease value of factor if number of cores
 *			  per CPT is above a limit.
 * ?_NTHRS_MAX		# overall threads can be created for a service,
 *			  it's a soft limit because if service is running
 *			  on machine with hundreds of cores and tens of
 *			  CPU partitions, we need to guarantee each partition
 *			  has ?_NTHRS_BASE threads, which means total threads
 *			  will be ?_NTHRS_BASE * number_of_cpts which can
 *			  exceed ?_NTHRS_MAX.
 *
 * Examples
 *
 * #define MDS_NTHRS_INIT	2
 * #define MDS_NTHRS_BASE	64
 * #define MDS_NTHRS_FACTOR	8
 * #define MDS_NTHRS_MAX	1024
 *
 * Example 1):
 * ---------------------------------------------------------------------
 * Server(A) has 16 cores, user configured it to 4 partitions so each
 * partition has 4 cores, then actual number of service threads on each
 * partition is:
 *     MDS_NTHRS_BASE(64) + cores(4) * MDS_NTHRS_FACTOR(8) = 96
 *
 * Total number of threads for the service is:
 *     96 * partitions(4) = 384
 *
 * Example 2):
 * ---------------------------------------------------------------------
 * Server(B) has 32 cores, user configured it to 4 partitions so each
 * partition has 8 cores, then actual number of service threads on each
 * partition is:
 *     MDS_NTHRS_BASE(64) + cores(8) * MDS_NTHRS_FACTOR(8) = 128
 *
 * Total number of threads for the service is:
 *     128 * partitions(4) = 512
 *
 * Example 3):
 * ---------------------------------------------------------------------
 * Server(B) has 96 cores, user configured it to 8 partitions so each
 * partition has 12 cores, then actual number of service threads on each
 * partition is:
 *     MDS_NTHRS_BASE(64) + cores(12) * MDS_NTHRS_FACTOR(8) = 160
 *
 * Total number of threads for the service is:
 *     160 * partitions(8) = 1280
 *
 * However, it's above the soft limit MDS_NTHRS_MAX, so we choose this number
 * as upper limit of threads number for each partition:
 *     MDS_NTHRS_MAX(1024) / partitions(8) = 128
 *
 * Example 4):
 * ---------------------------------------------------------------------
 * Server(C) have a thousand of cores and user configured it to 32 partitions
 *     MDS_NTHRS_BASE(64) * 32 = 2048
 *
 * which is already above soft limit MDS_NTHRS_MAX(1024), but we still need
 * to guarantee that each partition has at least MDS_NTHRS_BASE(64) threads
 * to keep service healthy, so total number of threads will just be 2048.
 *
 * NB: we don't suggest to choose server with that many cores because backend
 *     filesystem itself, buffer cache, or underlying network stack might
 *     have some SMP scalability issues at that large scale.
 *
 *     If user already has a fat machine with hundreds or thousands of cores,
 *     there are two choices for configuration:
 *     a) create CPU table from subset of all CPUs and run Lustre on
 *	top of this subset
 *     b) bind service threads on a few partitions, see modparameters of
 *	MDS and OSS for details
*
 * NB: these calculations (and examples below) are simplified to help
 *     understanding, the real implementation is a little more complex,
 *     please see ptlrpc_server_nthreads_check() for details.
 *
 */

 /*
  * LDLM threads constants:
  *
  * Given 8 as factor and 24 as base threads number
  *
  * example 1)
  * On 4-core machine we will have 24 + 8 * 4 = 56 threads.
  *
  * example 2)
  * On 8-core machine with 2 partitions we will have 24 + 4 * 8 = 56
  * threads for each partition and total threads number will be 112.
  *
  * example 3)
  * On 64-core machine with 8 partitions we will need LDLM_NTHRS_BASE(24)
  * threads for each partition to keep service healthy, so total threads
  * number should be 24 * 8 = 192.
  *
  * So with these constants, threads number will be at the similar level
  * of old versions, unless target machine has over a hundred cores
  */
#define LDLM_THR_FACTOR		8
#define LDLM_NTHRS_INIT		PTLRPC_NTHRS_INIT
#define LDLM_NTHRS_BASE		24
#define LDLM_NTHRS_MAX		(num_online_cpus() == 1 ? 64 : 128)

#define LDLM_BL_THREADS   LDLM_NTHRS_AUTO_INIT
#define LDLM_CLIENT_NBUFS 1
#define LDLM_SERVER_NBUFS 64
#define LDLM_BUFSIZE      (8 * 1024)
#define LDLM_MAXREQSIZE   (5 * 1024)
#define LDLM_MAXREPSIZE   (1024)

#define MDS_MAXREQSIZE		(5 * 1024)	/* >= 4736 */

/**
 * FIEMAP request can be 4K+ for now
 */
#define OST_MAXREQSIZE		(16 * 1024)

/* Macro to hide a typecast. */
#define ptlrpc_req_async_args(req) ((void *)&req->rq_async_args)

struct ptlrpc_replay_async_args {
	int		praa_old_state;
	int		praa_old_status;
};

/**
 * Structure to single define portal connection.
 */
struct ptlrpc_connection {
	/** linkage for connections hash table */
	struct hlist_node	c_hash;
	/** Our own lnet nid for this connection */
	lnet_nid_t	      c_self;
	/** Remote side nid for this connection */
	struct lnet_process_id	c_peer;
	/** UUID of the other side */
	struct obd_uuid	 c_remote_uuid;
	/** reference counter for this connection */
	atomic_t	    c_refcount;
};

/** Client definition for PortalRPC */
struct ptlrpc_client {
	/** What lnet portal does this client send messages to by default */
	__u32		   cli_request_portal;
	/** What portal do we expect replies on */
	__u32		   cli_reply_portal;
	/** Name of the client */
	char		   *cli_name;
};

/** state flags of requests */
/* XXX only ones left are those used by the bulk descs as well! */
#define PTL_RPC_FL_INTR      (1 << 0)  /* reply wait was interrupted by user */
#define PTL_RPC_FL_TIMEOUT   (1 << 7)  /* request timed out waiting for reply */

#define REQ_MAX_ACK_LOCKS 8

union ptlrpc_async_args {
	/**
	 * Scratchpad for passing args to completion interpreter. Users
	 * cast to the struct of their choosing, and BUILD_BUG_ON oversized
	 * arguments.  For _tons_ of context, kmalloc a struct and store
	 * a pointer to it here.  The pointer_arg ensures this struct is at
	 * least big enough for that.
	 */
	void      *pointer_arg[11];
	__u64      space[7];
};

struct ptlrpc_request_set;
typedef int (*set_interpreter_func)(struct ptlrpc_request_set *, void *, int);
typedef int (*set_producer_func)(struct ptlrpc_request_set *, void *);

/**
 * Definition of request set structure.
 * Request set is a list of requests (not necessary to the same target) that
 * once populated with RPCs could be sent in parallel.
 * There are two kinds of request sets. General purpose and with dedicated
 * serving thread. Example of the latter is ptlrpcd set.
 * For general purpose sets once request set started sending it is impossible
 * to add new requests to such set.
 * Provides a way to call "completion callbacks" when all requests in the set
 * returned.
 */
struct ptlrpc_request_set {
	atomic_t	  set_refcount;
	/** number of in queue requests */
	atomic_t	  set_new_count;
	/** number of uncompleted requests */
	atomic_t	  set_remaining;
	/** wait queue to wait on for request events */
	wait_queue_head_t	   set_waitq;
	wait_queue_head_t	  *set_wakeup_ptr;
	/** List of requests in the set */
	struct list_head	    set_requests;
	/**
	 * List of completion callbacks to be called when the set is completed
	 * This is only used if \a set_interpret is NULL.
	 * Links struct ptlrpc_set_cbdata.
	 */
	struct list_head	    set_cblist;
	/** Completion callback, if only one. */
	set_interpreter_func  set_interpret;
	/** opaq argument passed to completion \a set_interpret callback. */
	void		 *set_arg;
	/**
	 * Lock for \a set_new_requests manipulations
	 * locked so that any old caller can communicate requests to
	 * the set holder who can then fold them into the lock-free set
	 */
	spinlock_t		set_new_req_lock;
	/** List of new yet unsent requests. Only used with ptlrpcd now. */
	struct list_head	    set_new_requests;

	/** rq_status of requests that have been freed already */
	int		   set_rc;
	/** Additional fields used by the flow control extension */
	/** Maximum number of RPCs in flight */
	int		   set_max_inflight;
	/** Callback function used to generate RPCs */
	set_producer_func     set_producer;
	/** opaq argument passed to the producer callback */
	void		 *set_producer_arg;
};

/**
 * Description of a single ptrlrpc_set callback
 */
struct ptlrpc_set_cbdata {
	/** List linkage item */
	struct list_head	      psc_item;
	/** Pointer to interpreting function */
	set_interpreter_func    psc_interpret;
	/** Opaq argument to pass to the callback */
	void		   *psc_data;
};

struct ptlrpc_bulk_desc;
struct ptlrpc_service_part;
struct ptlrpc_service;

/**
 * ptlrpc callback & work item stuff
 */
struct ptlrpc_cb_id {
	void   (*cbid_fn)(struct lnet_event *ev); /* specific callback fn */
	void    *cbid_arg;		      /* additional arg */
};

/** Maximum number of locks to fit into reply state */
#define RS_MAX_LOCKS 8
#define RS_DEBUG     0

/**
 * Structure to define reply state on the server
 * Reply state holds various reply message information. Also for "difficult"
 * replies (rep-ack case) we store the state after sending reply and wait
 * for the client to acknowledge the reception. In these cases locks could be
 * added to the state for replay/failover consistency guarantees.
 */
struct ptlrpc_reply_state {
	/** Callback description */
	struct ptlrpc_cb_id    rs_cb_id;
	/** Linkage for list of all reply states in a system */
	struct list_head	     rs_list;
	/** Linkage for list of all reply states on same export */
	struct list_head	     rs_exp_list;
	/** Linkage for list of all reply states for same obd */
	struct list_head	     rs_obd_list;
#if RS_DEBUG
	struct list_head	     rs_debug_list;
#endif
	/** A spinlock to protect the reply state flags */
	spinlock_t		rs_lock;
	/** Reply state flags */
	unsigned long	  rs_difficult:1; /* ACK/commit stuff */
	unsigned long	  rs_no_ack:1;    /* no ACK, even for
					   * difficult requests
					   */
	unsigned long	  rs_scheduled:1;     /* being handled? */
	unsigned long	  rs_scheduled_ever:1;/* any schedule attempts? */
	unsigned long	  rs_handled:1;  /* been handled yet? */
	unsigned long	  rs_on_net:1;   /* reply_out_callback pending? */
	unsigned long	  rs_prealloc:1; /* rs from prealloc list */
	unsigned long	  rs_committed:1;/* the transaction was committed
					  * and the rs was dispatched
					  */
	atomic_t		rs_refcount;	/* number of users */
	/** Number of locks awaiting client ACK */
	int			rs_nlocks;

	/** Size of the state */
	int		    rs_size;
	/** opcode */
	__u32		  rs_opc;
	/** Transaction number */
	__u64		  rs_transno;
	/** xid */
	__u64		  rs_xid;
	struct obd_export     *rs_export;
	struct ptlrpc_service_part *rs_svcpt;
	/** Lnet metadata handle for the reply */
	struct lnet_handle_md		rs_md_h;

	/** Context for the service thread */
	struct ptlrpc_svc_ctx *rs_svc_ctx;
	/** Reply buffer (actually sent to the client), encoded if needed */
	struct lustre_msg     *rs_repbuf;       /* wrapper */
	/** Size of the reply buffer */
	int		    rs_repbuf_len;   /* wrapper buf length */
	/** Size of the reply message */
	int		    rs_repdata_len;  /* wrapper msg length */
	/**
	 * Actual reply message. Its content is encrypted (if needed) to
	 * produce reply buffer for actual sending. In simple case
	 * of no network encryption we just set \a rs_repbuf to \a rs_msg
	 */
	struct lustre_msg     *rs_msg;	  /* reply message */

	/** Handles of locks awaiting client reply ACK */
	struct lustre_handle   rs_locks[RS_MAX_LOCKS];
	/** Lock modes of locks in \a rs_locks */
	enum ldlm_mode	    rs_modes[RS_MAX_LOCKS];
};

struct ptlrpc_thread;

/** RPC stages */
enum rq_phase {
	RQ_PHASE_NEW	    = 0xebc0de00,
	RQ_PHASE_RPC	    = 0xebc0de01,
	RQ_PHASE_BULK	   = 0xebc0de02,
	RQ_PHASE_INTERPRET      = 0xebc0de03,
	RQ_PHASE_COMPLETE       = 0xebc0de04,
	RQ_PHASE_UNREG_RPC	= 0xebc0de05,
	RQ_PHASE_UNREG_BULK	= 0xebc0de06,
	RQ_PHASE_UNDEFINED	= 0xebc0de07
};

/** Type of request interpreter call-back */
typedef int (*ptlrpc_interpterer_t)(const struct lu_env *env,
				    struct ptlrpc_request *req,
				    void *arg, int rc);

/**
 * Definition of request pool structure.
 * The pool is used to store empty preallocated requests for the case
 * when we would actually need to send something without performing
 * any allocations (to avoid e.g. OOM).
 */
struct ptlrpc_request_pool {
	/** Locks the list */
	spinlock_t prp_lock;
	/** list of ptlrpc_request structs */
	struct list_head prp_req_list;
	/** Maximum message size that would fit into a request from this pool */
	int prp_rq_size;
	/** Function to allocate more requests for this pool */
	int (*prp_populate)(struct ptlrpc_request_pool *, int);
};

struct lu_context;
struct lu_env;

struct ldlm_lock;

#include <lustre_nrs.h>

/**
 * Basic request prioritization operations structure.
 * The whole idea is centered around locks and RPCs that might affect locks.
 * When a lock is contended we try to give priority to RPCs that might lead
 * to fastest release of that lock.
 * Currently only implemented for OSTs only in a way that makes all
 * IO and truncate RPCs that are coming from a locked region where a lock is
 * contended a priority over other requests.
 */
struct ptlrpc_hpreq_ops {
	/**
	 * Check if the lock handle of the given lock is the same as
	 * taken from the request.
	 */
	int  (*hpreq_lock_match)(struct ptlrpc_request *, struct ldlm_lock *);
	/**
	 * Check if the request is a high priority one.
	 */
	int  (*hpreq_check)(struct ptlrpc_request *);
	/**
	 * Called after the request has been handled.
	 */
	void (*hpreq_fini)(struct ptlrpc_request *);
};

struct ptlrpc_cli_req {
	/** For bulk requests on client only: bulk descriptor */
	struct ptlrpc_bulk_desc		*cr_bulk;
	/** optional time limit for send attempts */
	long				 cr_delay_limit;
	/** time request was first queued */
	time_t				 cr_queued_time;
	/** request sent timeval */
	struct timespec64		 cr_sent_tv;
	/** time for request really sent out */
	time64_t			 cr_sent_out;
	/** when req reply unlink must finish. */
	time64_t			 cr_reply_deadline;
	/** when req bulk unlink must finish. */
	time64_t			 cr_bulk_deadline;
	/** when req unlink must finish. */
	time64_t			 cr_req_deadline;
	/** Portal to which this request would be sent */
	short				 cr_req_ptl;
	/** Portal where to wait for reply and where reply would be sent */
	short				 cr_rep_ptl;
	/** request resending number */
	unsigned int			 cr_resend_nr;
	/** What was import generation when this request was sent */
	int				 cr_imp_gen;
	enum lustre_imp_state		 cr_send_state;
	/** Per-request waitq introduced by bug 21938 for recovery waiting */
	wait_queue_head_t		 cr_set_waitq;
	/** Link item for request set lists */
	struct list_head		 cr_set_chain;
	/** link to waited ctx */
	struct list_head		 cr_ctx_chain;

	/** client's half ctx */
	struct ptlrpc_cli_ctx		*cr_cli_ctx;
	/** Link back to the request set */
	struct ptlrpc_request_set	*cr_set;
	/** outgoing request MD handle */
	struct lnet_handle_md		 cr_req_md_h;
	/** request-out callback parameter */
	struct ptlrpc_cb_id		 cr_req_cbid;
	/** incoming reply MD handle */
	struct lnet_handle_md		 cr_reply_md_h;
	wait_queue_head_t		 cr_reply_waitq;
	/** reply callback parameter */
	struct ptlrpc_cb_id		 cr_reply_cbid;
	/** Async completion handler, called when reply is received */
	ptlrpc_interpterer_t		 cr_reply_interp;
	/** Async completion context */
	union ptlrpc_async_args		 cr_async_args;
	/** Opaq data for replay and commit callbacks. */
	void				*cr_cb_data;
	/** Link to the imp->imp_unreplied_list */
	struct list_head		 cr_unreplied_list;
	/**
	 * Commit callback, called when request is committed and about to be
	 * freed.
	 */
	void (*cr_commit_cb)(struct ptlrpc_request *);
	/** Replay callback, called after request is replayed at recovery */
	void (*cr_replay_cb)(struct ptlrpc_request *);
};

/** client request member alias */
/* NB: these alias should NOT be used by any new code, instead they should
 * be removed step by step to avoid potential abuse
 */
#define rq_bulk			rq_cli.cr_bulk
#define rq_delay_limit		rq_cli.cr_delay_limit
#define rq_queued_time		rq_cli.cr_queued_time
#define rq_sent_tv		rq_cli.cr_sent_tv
#define rq_real_sent		rq_cli.cr_sent_out
#define rq_reply_deadline	rq_cli.cr_reply_deadline
#define rq_bulk_deadline	rq_cli.cr_bulk_deadline
#define rq_req_deadline		rq_cli.cr_req_deadline
#define rq_nr_resend		rq_cli.cr_resend_nr
#define rq_request_portal	rq_cli.cr_req_ptl
#define rq_reply_portal		rq_cli.cr_rep_ptl
#define rq_import_generation	rq_cli.cr_imp_gen
#define rq_send_state		rq_cli.cr_send_state
#define rq_set_chain		rq_cli.cr_set_chain
#define rq_ctx_chain		rq_cli.cr_ctx_chain
#define rq_set			rq_cli.cr_set
#define rq_set_waitq		rq_cli.cr_set_waitq
#define rq_cli_ctx		rq_cli.cr_cli_ctx
#define rq_req_md_h		rq_cli.cr_req_md_h
#define rq_req_cbid		rq_cli.cr_req_cbid
#define rq_reply_md_h		rq_cli.cr_reply_md_h
#define rq_reply_waitq		rq_cli.cr_reply_waitq
#define rq_reply_cbid		rq_cli.cr_reply_cbid
#define rq_interpret_reply	rq_cli.cr_reply_interp
#define rq_async_args		rq_cli.cr_async_args
#define rq_cb_data		rq_cli.cr_cb_data
#define rq_unreplied_list	rq_cli.cr_unreplied_list
#define rq_commit_cb		rq_cli.cr_commit_cb
#define rq_replay_cb		rq_cli.cr_replay_cb

struct ptlrpc_srv_req {
	/** initial thread servicing this request */
	struct ptlrpc_thread		*sr_svc_thread;
	/**
	 * Server side list of incoming unserved requests sorted by arrival
	 * time.  Traversed from time to time to notice about to expire
	 * requests and sent back "early replies" to clients to let them
	 * know server is alive and well, just very busy to service their
	 * requests in time
	 */
	struct list_head		sr_timed_list;
	/** server-side per-export list */
	struct list_head		sr_exp_list;
	/** server-side history, used for debuging purposes. */
	struct list_head		sr_hist_list;
	/** history sequence # */
	__u64				sr_hist_seq;
	/** the index of service's srv_at_array into which request is linked */
	time64_t			sr_at_index;
	/** authed uid */
	uid_t				sr_auth_uid;
	/** authed uid mapped to */
	uid_t				sr_auth_mapped_uid;
	/** RPC is generated from what part of Lustre */
	enum lustre_sec_part		sr_sp_from;
	/** request session context */
	struct lu_context		sr_ses;
	/** \addtogroup  nrs
	 * @{
	 */
	/** stub for NRS request */
	struct ptlrpc_nrs_request	sr_nrq;
	/** @} nrs */
	/** request arrival time */
	struct timespec64		sr_arrival_time;
	/** server's half ctx */
	struct ptlrpc_svc_ctx		*sr_svc_ctx;
	/** (server side), pointed directly into req buffer */
	struct ptlrpc_user_desc		*sr_user_desc;
	/** separated reply state */
	struct ptlrpc_reply_state	*sr_reply_state;
	/** server-side hp handlers */
	struct ptlrpc_hpreq_ops		*sr_ops;
	/** incoming request buffer */
	struct ptlrpc_request_buffer_desc *sr_rqbd;
};

/** server request member alias */
/* NB: these alias should NOT be used by any new code, instead they should
 * be removed step by step to avoid potential abuse
 */
#define rq_svc_thread		rq_srv.sr_svc_thread
#define rq_timed_list		rq_srv.sr_timed_list
#define rq_exp_list		rq_srv.sr_exp_list
#define rq_history_list		rq_srv.sr_hist_list
#define rq_history_seq		rq_srv.sr_hist_seq
#define rq_at_index		rq_srv.sr_at_index
#define rq_auth_uid		rq_srv.sr_auth_uid
#define rq_auth_mapped_uid	rq_srv.sr_auth_mapped_uid
#define rq_sp_from		rq_srv.sr_sp_from
#define rq_session		rq_srv.sr_ses
#define rq_nrq			rq_srv.sr_nrq
#define rq_arrival_time		rq_srv.sr_arrival_time
#define rq_reply_state		rq_srv.sr_reply_state
#define rq_svc_ctx		rq_srv.sr_svc_ctx
#define rq_user_desc		rq_srv.sr_user_desc
#define rq_ops			rq_srv.sr_ops
#define rq_rqbd			rq_srv.sr_rqbd

/**
 * Represents remote procedure call.
 *
 * This is a staple structure used by everybody wanting to send a request
 * in Lustre.
 */
struct ptlrpc_request {
	/* Request type: one of PTL_RPC_MSG_* */
	int				 rq_type;
	/** Result of request processing */
	int				 rq_status;
	/**
	 * Linkage item through which this request is included into
	 * sending/delayed lists on client and into rqbd list on server
	 */
	struct list_head		 rq_list;
	/** Lock to protect request flags and some other important bits, like
	 * rq_list
	 */
	spinlock_t rq_lock;
	/** client-side flags are serialized by rq_lock @{ */
	unsigned int rq_intr:1, rq_replied:1, rq_err:1,
		rq_timedout:1, rq_resend:1, rq_restart:1,
		/**
		 * when ->rq_replay is set, request is kept by the client even
		 * after server commits corresponding transaction. This is
		 * used for operations that require sequence of multiple
		 * requests to be replayed. The only example currently is file
		 * open/close. When last request in such a sequence is
		 * committed, ->rq_replay is cleared on all requests in the
		 * sequence.
		 */
		rq_replay:1,
		rq_no_resend:1, rq_waiting:1, rq_receiving_reply:1,
		rq_no_delay:1, rq_net_err:1, rq_wait_ctx:1,
		rq_early:1,
		rq_req_unlinked:1,	/* unlinked request buffer from lnet */
		rq_reply_unlinked:1,	/* unlinked reply buffer from lnet */
		rq_memalloc:1,      /* req originated from "kswapd" */
		rq_committed:1,
		rq_reply_truncated:1,
		/** whether the "rq_set" is a valid one */
		rq_invalid_rqset:1,
		rq_generation_set:1,
		/** do not resend request on -EINPROGRESS */
		rq_no_retry_einprogress:1,
		/* allow the req to be sent if the import is in recovery
		 * status
		 */
		rq_allow_replay:1,
		/* bulk request, sent to server, but uncommitted */
		rq_unstable:1;
	/** @} */

	/** server-side flags @{ */
	unsigned int
		rq_hp:1,		/**< high priority RPC */
		rq_at_linked:1,		/**< link into service's srv_at_array */
		rq_packed_final:1;	/**< packed final reply */
	/** @} */

	/** one of RQ_PHASE_* */
	enum rq_phase			rq_phase;
	/** one of RQ_PHASE_* to be used next */
	enum rq_phase			rq_next_phase;
	/**
	 * client-side refcount for SENT race, server-side refcount
	 * for multiple replies
	 */
	atomic_t			rq_refcount;
	/**
	 * client-side:
	 * !rq_truncate : # reply bytes actually received,
	 *  rq_truncate : required repbuf_len for resend
	 */
	int rq_nob_received;
	/** Request length */
	int rq_reqlen;
	/** Reply length */
	int rq_replen;
	/** Pool if request is from preallocated list */
	struct ptlrpc_request_pool     *rq_pool;
	/** Request message - what client sent */
	struct lustre_msg *rq_reqmsg;
	/** Reply message - server response */
	struct lustre_msg *rq_repmsg;
	/** Transaction number */
	__u64 rq_transno;
	/** xid */
	__u64 rq_xid;
	/** bulk match bits */
	u64				rq_mbits;
	/**
	 * List item to for replay list. Not yet committed requests get linked
	 * there.
	 * Also see \a rq_replay comment above.
	 * It's also link chain on obd_export::exp_req_replay_queue
	 */
	struct list_head rq_replay_list;
	/** non-shared members for client & server request*/
	union {
		struct ptlrpc_cli_req    rq_cli;
		struct ptlrpc_srv_req    rq_srv;
	};
	/**
	 * security and encryption data
	 * @{
	 */
	/** description of flavors for client & server */
	struct sptlrpc_flavor		rq_flvr;

	/* client/server security flags */
	unsigned int
				 rq_ctx_init:1,      /* context initiation */
				 rq_ctx_fini:1,      /* context destroy */
				 rq_bulk_read:1,     /* request bulk read */
				 rq_bulk_write:1,    /* request bulk write */
				 /* server authentication flags */
				 rq_auth_gss:1,      /* authenticated by gss */
				 rq_auth_usr_root:1, /* authed as root */
				 rq_auth_usr_mdt:1,  /* authed as mdt */
				 rq_auth_usr_ost:1,  /* authed as ost */
				 /* security tfm flags */
				 rq_pack_udesc:1,
				 rq_pack_bulk:1,
				 /* doesn't expect reply FIXME */
				 rq_no_reply:1,
				 rq_pill_init:1, /* pill initialized */
				 rq_srv_req:1; /* server request */

	/** various buffer pointers */
	struct lustre_msg       *rq_reqbuf;	/**< req wrapper */
	char			*rq_repbuf;	/**< rep buffer */
	struct lustre_msg       *rq_repdata;	/**< rep wrapper msg */
	/** only in priv mode */
	struct lustre_msg       *rq_clrbuf;
	int		      rq_reqbuf_len;  /* req wrapper buf len */
	int		      rq_reqdata_len; /* req wrapper msg len */
	int		      rq_repbuf_len;  /* rep buffer len */
	int		      rq_repdata_len; /* rep wrapper msg len */
	int		      rq_clrbuf_len;  /* only in priv mode */
	int		      rq_clrdata_len; /* only in priv mode */

	/** early replies go to offset 0, regular replies go after that */
	unsigned int	     rq_reply_off;

	/** @} */

	/** Fields that help to see if request and reply were swabbed or not */
	__u32 rq_req_swab_mask;
	__u32 rq_rep_swab_mask;

	/** how many early replies (for stats) */
	int rq_early_count;

	/** Server-side, export on which request was received */
	struct obd_export		*rq_export;
	/** import where request is being sent */
	struct obd_import		*rq_import;
	/** our LNet NID */
	lnet_nid_t	   rq_self;
	/** Peer description (the other side) */
	struct lnet_process_id	rq_peer;
	/**
	 * service time estimate (secs)
	 * If the request is not served by this time, it is marked as timed out.
	 */
	int			rq_timeout;
	/**
	 * when request/reply sent (secs), or time when request should be sent
	 */
	time64_t rq_sent;
	/** when request must finish. */
	time64_t		  rq_deadline;
	/** request format description */
	struct req_capsule	  rq_pill;
};

/**
 * Call completion handler for rpc if any, return it's status or original
 * rc if there was no handler defined for this request.
 */
static inline int ptlrpc_req_interpret(const struct lu_env *env,
				       struct ptlrpc_request *req, int rc)
{
	if (req->rq_interpret_reply) {
		req->rq_status = req->rq_interpret_reply(env, req,
							 &req->rq_async_args,
							 rc);
		return req->rq_status;
	}
	return rc;
}

/*
 * Can the request be moved from the regular NRS head to the high-priority NRS
 * head (of the same PTLRPC service partition), if any?
 *
 * For a reliable result, this should be checked under svcpt->scp_req lock.
 */
static inline bool ptlrpc_nrs_req_can_move(struct ptlrpc_request *req)
{
	struct ptlrpc_nrs_request *nrq = &req->rq_nrq;

	/**
	 * LU-898: Check ptlrpc_nrs_request::nr_enqueued to make sure the
	 * request has been enqueued first, and ptlrpc_nrs_request::nr_started
	 * to make sure it has not been scheduled yet (analogous to previous
	 * (non-NRS) checking of !list_empty(&ptlrpc_request::rq_list).
	 */
	return nrq->nr_enqueued && !nrq->nr_started && !req->rq_hp;
}

/** @} nrs */

/**
 * Returns 1 if request buffer at offset \a index was already swabbed
 */
static inline int lustre_req_swabbed(struct ptlrpc_request *req, size_t index)
{
	LASSERT(index < sizeof(req->rq_req_swab_mask) * 8);
	return req->rq_req_swab_mask & (1 << index);
}

/**
 * Returns 1 if request reply buffer at offset \a index was already swabbed
 */
static inline int lustre_rep_swabbed(struct ptlrpc_request *req, size_t index)
{
	LASSERT(index < sizeof(req->rq_rep_swab_mask) * 8);
	return req->rq_rep_swab_mask & (1 << index);
}

/**
 * Returns 1 if request needs to be swabbed into local cpu byteorder
 */
static inline int ptlrpc_req_need_swab(struct ptlrpc_request *req)
{
	return lustre_req_swabbed(req, MSG_PTLRPC_HEADER_OFF);
}

/**
 * Returns 1 if request reply needs to be swabbed into local cpu byteorder
 */
static inline int ptlrpc_rep_need_swab(struct ptlrpc_request *req)
{
	return lustre_rep_swabbed(req, MSG_PTLRPC_HEADER_OFF);
}

/**
 * Mark request buffer at offset \a index that it was already swabbed
 */
static inline void lustre_set_req_swabbed(struct ptlrpc_request *req,
					  size_t index)
{
	LASSERT(index < sizeof(req->rq_req_swab_mask) * 8);
	LASSERT((req->rq_req_swab_mask & (1 << index)) == 0);
	req->rq_req_swab_mask |= 1 << index;
}

/**
 * Mark request reply buffer at offset \a index that it was already swabbed
 */
static inline void lustre_set_rep_swabbed(struct ptlrpc_request *req,
					  size_t index)
{
	LASSERT(index < sizeof(req->rq_rep_swab_mask) * 8);
	LASSERT((req->rq_rep_swab_mask & (1 << index)) == 0);
	req->rq_rep_swab_mask |= 1 << index;
}

/**
 * Convert numerical request phase value \a phase into text string description
 */
static inline const char *
ptlrpc_phase2str(enum rq_phase phase)
{
	switch (phase) {
	case RQ_PHASE_NEW:
		return "New";
	case RQ_PHASE_RPC:
		return "Rpc";
	case RQ_PHASE_BULK:
		return "Bulk";
	case RQ_PHASE_INTERPRET:
		return "Interpret";
	case RQ_PHASE_COMPLETE:
		return "Complete";
	case RQ_PHASE_UNREG_RPC:
		return "UnregRPC";
	case RQ_PHASE_UNREG_BULK:
		return "UnregBULK";
	default:
		return "?Phase?";
	}
}

/**
 * Convert numerical request phase of the request \a req into text stringi
 * description
 */
static inline const char *
ptlrpc_rqphase2str(struct ptlrpc_request *req)
{
	return ptlrpc_phase2str(req->rq_phase);
}

/**
 * Debugging functions and helpers to print request structure into debug log
 * @{
 */
/* Spare the preprocessor, spoil the bugs. */
#define FLAG(field, str) (field ? str : "")

/** Convert bit flags into a string */
#define DEBUG_REQ_FLAGS(req)						    \
	ptlrpc_rqphase2str(req),						\
	FLAG(req->rq_intr, "I"), FLAG(req->rq_replied, "R"),		    \
	FLAG(req->rq_err, "E"),	FLAG(req->rq_net_err, "e"),		    \
	FLAG(req->rq_timedout, "X") /* eXpired */, FLAG(req->rq_resend, "S"),   \
	FLAG(req->rq_restart, "T"), FLAG(req->rq_replay, "P"),		  \
	FLAG(req->rq_no_resend, "N"),					   \
	FLAG(req->rq_waiting, "W"),					     \
	FLAG(req->rq_wait_ctx, "C"), FLAG(req->rq_hp, "H"),		     \
	FLAG(req->rq_committed, "M")

#define REQ_FLAGS_FMT "%s:%s%s%s%s%s%s%s%s%s%s%s%s%s"

void _debug_req(struct ptlrpc_request *req,
		struct libcfs_debug_msg_data *data, const char *fmt, ...)
	__printf(3, 4);

/**
 * Helper that decides if we need to print request according to current debug
 * level settings
 */
#define debug_req(msgdata, mask, cdls, req, fmt, a...)			\
do {									  \
	CFS_CHECK_STACK(msgdata, mask, cdls);				 \
									      \
	if (((mask) & D_CANTMASK) != 0 ||				     \
	    ((libcfs_debug & (mask)) != 0 &&				  \
	     (libcfs_subsystem_debug & DEBUG_SUBSYSTEM) != 0))		\
		_debug_req((req), msgdata, fmt, ##a);			 \
} while (0)

/**
 * This is the debug print function you need to use to print request structure
 * content into lustre debug log.
 * for most callers (level is a constant) this is resolved at compile time
 */
#define DEBUG_REQ(level, req, fmt, args...)				   \
do {									  \
	if ((level) & (D_ERROR | D_WARNING)) {				\
		static struct cfs_debug_limit_state cdls;			  \
		LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, level, &cdls);	    \
		debug_req(&msgdata, level, &cdls, req, "@@@ "fmt" ", ## args);\
	} else {							      \
		LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, level, NULL);	     \
		debug_req(&msgdata, level, NULL, req, "@@@ "fmt" ", ## args); \
	}								     \
} while (0)
/** @} */

/**
 * Structure that defines a single page of a bulk transfer
 */
struct ptlrpc_bulk_page {
	/** Linkage to list of pages in a bulk */
	struct list_head       bp_link;
	/**
	 * Number of bytes in a page to transfer starting from \a bp_pageoffset
	 */
	int	      bp_buflen;
	/** offset within a page */
	int	      bp_pageoffset;
	/** The page itself */
	struct page     *bp_page;
};

enum ptlrpc_bulk_op_type {
	PTLRPC_BULK_OP_ACTIVE	= 0x00000001,
	PTLRPC_BULK_OP_PASSIVE	= 0x00000002,
	PTLRPC_BULK_OP_PUT	= 0x00000004,
	PTLRPC_BULK_OP_GET	= 0x00000008,
	PTLRPC_BULK_BUF_KVEC	= 0x00000010,
	PTLRPC_BULK_BUF_KIOV	= 0x00000020,
	PTLRPC_BULK_GET_SOURCE	= PTLRPC_BULK_OP_PASSIVE | PTLRPC_BULK_OP_GET,
	PTLRPC_BULK_PUT_SINK	= PTLRPC_BULK_OP_PASSIVE | PTLRPC_BULK_OP_PUT,
	PTLRPC_BULK_GET_SINK	= PTLRPC_BULK_OP_ACTIVE | PTLRPC_BULK_OP_GET,
	PTLRPC_BULK_PUT_SOURCE	= PTLRPC_BULK_OP_ACTIVE | PTLRPC_BULK_OP_PUT,
};

static inline bool ptlrpc_is_bulk_op_get(enum ptlrpc_bulk_op_type type)
{
	return (type & PTLRPC_BULK_OP_GET) == PTLRPC_BULK_OP_GET;
}

static inline bool ptlrpc_is_bulk_get_source(enum ptlrpc_bulk_op_type type)
{
	return (type & PTLRPC_BULK_GET_SOURCE) == PTLRPC_BULK_GET_SOURCE;
}

static inline bool ptlrpc_is_bulk_put_sink(enum ptlrpc_bulk_op_type type)
{
	return (type & PTLRPC_BULK_PUT_SINK) == PTLRPC_BULK_PUT_SINK;
}

static inline bool ptlrpc_is_bulk_get_sink(enum ptlrpc_bulk_op_type type)
{
	return (type & PTLRPC_BULK_GET_SINK) == PTLRPC_BULK_GET_SINK;
}

static inline bool ptlrpc_is_bulk_put_source(enum ptlrpc_bulk_op_type type)
{
	return (type & PTLRPC_BULK_PUT_SOURCE) == PTLRPC_BULK_PUT_SOURCE;
}

static inline bool ptlrpc_is_bulk_desc_kvec(enum ptlrpc_bulk_op_type type)
{
	return ((type & PTLRPC_BULK_BUF_KVEC) | (type & PTLRPC_BULK_BUF_KIOV))
		== PTLRPC_BULK_BUF_KVEC;
}

static inline bool ptlrpc_is_bulk_desc_kiov(enum ptlrpc_bulk_op_type type)
{
	return ((type & PTLRPC_BULK_BUF_KVEC) | (type & PTLRPC_BULK_BUF_KIOV))
		== PTLRPC_BULK_BUF_KIOV;
}

static inline bool ptlrpc_is_bulk_op_active(enum ptlrpc_bulk_op_type type)
{
	return ((type & PTLRPC_BULK_OP_ACTIVE) |
		(type & PTLRPC_BULK_OP_PASSIVE)) == PTLRPC_BULK_OP_ACTIVE;
}

static inline bool ptlrpc_is_bulk_op_passive(enum ptlrpc_bulk_op_type type)
{
	return ((type & PTLRPC_BULK_OP_ACTIVE) |
		(type & PTLRPC_BULK_OP_PASSIVE)) == PTLRPC_BULK_OP_PASSIVE;
}

struct ptlrpc_bulk_frag_ops {
	/**
	 * Add a page \a page to the bulk descriptor \a desc
	 * Data to transfer in the page starts at offset \a pageoffset and
	 * amount of data to transfer from the page is \a len
	 */
	void (*add_kiov_frag)(struct ptlrpc_bulk_desc *desc,
			      struct page *page, int pageoffset, int len);

	/*
	 * Add a \a fragment to the bulk descriptor \a desc.
	 * Data to transfer in the fragment is pointed to by \a frag
	 * The size of the fragment is \a len
	 */
	int (*add_iov_frag)(struct ptlrpc_bulk_desc *desc, void *frag, int len);

	/**
	 * Uninitialize and free bulk descriptor \a desc.
	 * Works on bulk descriptors both from server and client side.
	 */
	void (*release_frags)(struct ptlrpc_bulk_desc *desc);
};

extern const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_pin_ops;
extern const struct ptlrpc_bulk_frag_ops ptlrpc_bulk_kiov_nopin_ops;

/**
 * Definition of bulk descriptor.
 * Bulks are special "Two phase" RPCs where initial request message
 * is sent first and it is followed bt a transfer (o receiving) of a large
 * amount of data to be settled into pages referenced from the bulk descriptors.
 * Bulks transfers (the actual data following the small requests) are done
 * on separate LNet portals.
 * In lustre we use bulk transfers for READ and WRITE transfers from/to OSTs.
 *  Another user is readpage for MDT.
 */
struct ptlrpc_bulk_desc {
	/** completed with failure */
	unsigned long bd_failure:1;
	/** client side */
	unsigned long bd_registered:1;
	/** For serialization with callback */
	spinlock_t bd_lock;
	/** Import generation when request for this bulk was sent */
	int bd_import_generation;
	/** {put,get}{source,sink}{kvec,kiov} */
	enum ptlrpc_bulk_op_type bd_type;
	/** LNet portal for this bulk */
	__u32 bd_portal;
	/** Server side - export this bulk created for */
	struct obd_export *bd_export;
	/** Client side - import this bulk was sent on */
	struct obd_import *bd_import;
	/** Back pointer to the request */
	struct ptlrpc_request *bd_req;
	struct ptlrpc_bulk_frag_ops *bd_frag_ops;
	wait_queue_head_t	    bd_waitq;	/* server side only WQ */
	int		    bd_iov_count;    /* # entries in bd_iov */
	int		    bd_max_iov;      /* allocated size of bd_iov */
	int		    bd_nob;	  /* # bytes covered */
	int		    bd_nob_transferred; /* # bytes GOT/PUT */

	u64			bd_last_mbits;

	struct ptlrpc_cb_id    bd_cbid;	 /* network callback info */
	lnet_nid_t	     bd_sender;       /* stash event::sender */
	int			bd_md_count;	/* # valid entries in bd_mds */
	int			bd_md_max_brw;	/* max entries in bd_mds */
	/** array of associated MDs */
	struct lnet_handle_md	bd_mds[PTLRPC_BULK_OPS_COUNT];

	union {
		struct {
			/*
			 * encrypt iov, size is either 0 or bd_iov_count.
			 */
			struct bio_vec *bd_enc_vec;
			struct bio_vec *bd_vec;	/* Array of bio_vecs */
		} bd_kiov;

		struct {
			struct kvec *bd_enc_kvec;
			struct kvec *bd_kvec;	/* Array of kvecs */
		} bd_kvec;
	} bd_u;
};

#define GET_KIOV(desc)			((desc)->bd_u.bd_kiov.bd_vec)
#define BD_GET_KIOV(desc, i)		((desc)->bd_u.bd_kiov.bd_vec[i])
#define GET_ENC_KIOV(desc)		((desc)->bd_u.bd_kiov.bd_enc_vec)
#define BD_GET_ENC_KIOV(desc, i)	((desc)->bd_u.bd_kiov.bd_enc_vec[i])
#define GET_KVEC(desc)			((desc)->bd_u.bd_kvec.bd_kvec)
#define BD_GET_KVEC(desc, i)		((desc)->bd_u.bd_kvec.bd_kvec[i])
#define GET_ENC_KVEC(desc)		((desc)->bd_u.bd_kvec.bd_enc_kvec)
#define BD_GET_ENC_KVEC(desc, i)	((desc)->bd_u.bd_kvec.bd_enc_kvec[i])

enum {
	SVC_STOPPED     = 1 << 0,
	SVC_STOPPING    = 1 << 1,
	SVC_STARTING    = 1 << 2,
	SVC_RUNNING     = 1 << 3,
	SVC_EVENT       = 1 << 4,
	SVC_SIGNAL      = 1 << 5,
};

#define PTLRPC_THR_NAME_LEN		32
/**
 * Definition of server service thread structure
 */
struct ptlrpc_thread {
	/**
	 * List of active threads in svc->srv_threads
	 */
	struct list_head t_link;
	/**
	 * thread-private data (preallocated memory)
	 */
	void *t_data;
	__u32 t_flags;
	/**
	 * service thread index, from ptlrpc_start_threads
	 */
	unsigned int t_id;
	/**
	 * service thread pid
	 */
	pid_t t_pid;
	/**
	 * put watchdog in the structure per thread b=14840
	 *
	 * Lustre watchdog is removed for client in the hope
	 * of a generic watchdog can be merged in kernel.
	 * When that happens, we should add below back.
	 *
	 * struct lc_watchdog *t_watchdog;
	 */
	/**
	 * the svc this thread belonged to b=18582
	 */
	struct ptlrpc_service_part	*t_svcpt;
	wait_queue_head_t			t_ctl_waitq;
	struct lu_env			*t_env;
	char				t_name[PTLRPC_THR_NAME_LEN];
};

static inline int thread_is_init(struct ptlrpc_thread *thread)
{
	return thread->t_flags == 0;
}

static inline int thread_is_stopped(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_STOPPED);
}

static inline int thread_is_stopping(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_STOPPING);
}

static inline int thread_is_starting(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_STARTING);
}

static inline int thread_is_running(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_RUNNING);
}

static inline int thread_is_event(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_EVENT);
}

static inline int thread_is_signal(struct ptlrpc_thread *thread)
{
	return !!(thread->t_flags & SVC_SIGNAL);
}

static inline void thread_clear_flags(struct ptlrpc_thread *thread, __u32 flags)
{
	thread->t_flags &= ~flags;
}

static inline void thread_set_flags(struct ptlrpc_thread *thread, __u32 flags)
{
	thread->t_flags = flags;
}

static inline void thread_add_flags(struct ptlrpc_thread *thread, __u32 flags)
{
	thread->t_flags |= flags;
}

static inline int thread_test_and_clear_flags(struct ptlrpc_thread *thread,
					      __u32 flags)
{
	if (thread->t_flags & flags) {
		thread->t_flags &= ~flags;
		return 1;
	}
	return 0;
}

/**
 * Request buffer descriptor structure.
 * This is a structure that contains one posted request buffer for service.
 * Once data land into a buffer, event callback creates actual request and
 * notifies wakes one of the service threads to process new incoming request.
 * More than one request can fit into the buffer.
 */
struct ptlrpc_request_buffer_desc {
	/** Link item for rqbds on a service */
	struct list_head	     rqbd_list;
	/** History of requests for this buffer */
	struct list_head	     rqbd_reqs;
	/** Back pointer to service for which this buffer is registered */
	struct ptlrpc_service_part *rqbd_svcpt;
	/** LNet descriptor */
	struct lnet_handle_md		rqbd_md_h;
	int		    rqbd_refcount;
	/** The buffer itself */
	char		  *rqbd_buffer;
	struct ptlrpc_cb_id    rqbd_cbid;
	/**
	 * This "embedded" request structure is only used for the
	 * last request to fit into the buffer
	 */
	struct ptlrpc_request  rqbd_req;
};

typedef int  (*svc_handler_t)(struct ptlrpc_request *req);

struct ptlrpc_service_ops {
	/**
	 * if non-NULL called during thread creation (ptlrpc_start_thread())
	 * to initialize service specific per-thread state.
	 */
	int		(*so_thr_init)(struct ptlrpc_thread *thr);
	/**
	 * if non-NULL called during thread shutdown (ptlrpc_main()) to
	 * destruct state created by ->srv_init().
	 */
	void		(*so_thr_done)(struct ptlrpc_thread *thr);
	/**
	 * Handler function for incoming requests for this service
	 */
	int		(*so_req_handler)(struct ptlrpc_request *req);
	/**
	 * function to determine priority of the request, it's called
	 * on every new request
	 */
	int		(*so_hpreq_handler)(struct ptlrpc_request *);
	/**
	 * service-specific print fn
	 */
	void		(*so_req_printer)(void *, struct ptlrpc_request *);
};

#ifndef __cfs_cacheline_aligned
/* NB: put it here for reducing patche dependence */
# define __cfs_cacheline_aligned
#endif

/**
 * How many high priority requests to serve before serving one normal
 * priority request
 */
#define PTLRPC_SVC_HP_RATIO 10

/**
 * Definition of PortalRPC service.
 * The service is listening on a particular portal (like tcp port)
 * and perform actions for a specific server like IO service for OST
 * or general metadata service for MDS.
 */
struct ptlrpc_service {
	/** serialize sysfs operations */
	spinlock_t			srv_lock;
	/** most often accessed fields */
	/** chain thru all services */
	struct list_head		      srv_list;
	/** service operations table */
	struct ptlrpc_service_ops	srv_ops;
	/** only statically allocated strings here; we don't clean them */
	char			   *srv_name;
	/** only statically allocated strings here; we don't clean them */
	char			   *srv_thread_name;
	/** service thread list */
	struct list_head		      srv_threads;
	/** threads # should be created for each partition on initializing */
	int				srv_nthrs_cpt_init;
	/** limit of threads number for each partition */
	int				srv_nthrs_cpt_limit;
	/** Root of debugfs dir tree for this service */
	struct dentry		   *srv_debugfs_entry;
	/** Pointer to statistic data for this service */
	struct lprocfs_stats	   *srv_stats;
	/** # hp per lp reqs to handle */
	int			     srv_hpreq_ratio;
	/** biggest request to receive */
	int			     srv_max_req_size;
	/** biggest reply to send */
	int			     srv_max_reply_size;
	/** size of individual buffers */
	int			     srv_buf_size;
	/** # buffers to allocate in 1 group */
	int			     srv_nbuf_per_group;
	/** Local portal on which to receive requests */
	__u32			   srv_req_portal;
	/** Portal on the client to send replies to */
	__u32			   srv_rep_portal;
	/**
	 * Tags for lu_context associated with this thread, see struct
	 * lu_context.
	 */
	__u32			   srv_ctx_tags;
	/** soft watchdog timeout multiplier */
	int			     srv_watchdog_factor;
	/** under unregister_service */
	unsigned			srv_is_stopping:1;

	/** max # request buffers in history per partition */
	int				srv_hist_nrqbds_cpt_max;
	/** number of CPTs this service bound on */
	int				srv_ncpts;
	/** CPTs array this service bound on */
	__u32				*srv_cpts;
	/** 2^srv_cptab_bits >= cfs_cpt_numbert(srv_cptable) */
	int				srv_cpt_bits;
	/** CPT table this service is running over */
	struct cfs_cpt_table		*srv_cptable;

	/* sysfs object */
	struct kobject			 srv_kobj;
	struct completion		 srv_kobj_unregister;
	/**
	 * partition data for ptlrpc service
	 */
	struct ptlrpc_service_part	*srv_parts[0];
};

/**
 * Definition of PortalRPC service partition data.
 * Although a service only has one instance of it right now, but we
 * will have multiple instances very soon (instance per CPT).
 *
 * it has four locks:
 * \a scp_lock
 *    serialize operations on rqbd and requests waiting for preprocess
 * \a scp_req_lock
 *    serialize operations active requests sent to this portal
 * \a scp_at_lock
 *    serialize adaptive timeout stuff
 * \a scp_rep_lock
 *    serialize operations on RS list (reply states)
 *
 * We don't have any use-case to take two or more locks at the same time
 * for now, so there is no lock order issue.
 */
struct ptlrpc_service_part {
	/** back reference to owner */
	struct ptlrpc_service		*scp_service __cfs_cacheline_aligned;
	/* CPT id, reserved */
	int				scp_cpt;
	/** always increasing number */
	int				scp_thr_nextid;
	/** # of starting threads */
	int				scp_nthrs_starting;
	/** # of stopping threads, reserved for shrinking threads */
	int				scp_nthrs_stopping;
	/** # running threads */
	int				scp_nthrs_running;
	/** service threads list */
	struct list_head			scp_threads;

	/**
	 * serialize the following fields, used for protecting
	 * rqbd list and incoming requests waiting for preprocess,
	 * threads starting & stopping are also protected by this lock.
	 */
	spinlock_t scp_lock __cfs_cacheline_aligned;
	/** total # req buffer descs allocated */
	int				scp_nrqbds_total;
	/** # posted request buffers for receiving */
	int				scp_nrqbds_posted;
	/** in progress of allocating rqbd */
	int				scp_rqbd_allocating;
	/** # incoming reqs */
	int				scp_nreqs_incoming;
	/** request buffers to be reposted */
	struct list_head			scp_rqbd_idle;
	/** req buffers receiving */
	struct list_head			scp_rqbd_posted;
	/** incoming reqs */
	struct list_head			scp_req_incoming;
	/** timeout before re-posting reqs, in tick */
	long			scp_rqbd_timeout;
	/**
	 * all threads sleep on this. This wait-queue is signalled when new
	 * incoming request arrives and when difficult reply has to be handled.
	 */
	wait_queue_head_t			scp_waitq;

	/** request history */
	struct list_head			scp_hist_reqs;
	/** request buffer history */
	struct list_head			scp_hist_rqbds;
	/** # request buffers in history */
	int				scp_hist_nrqbds;
	/** sequence number for request */
	__u64				scp_hist_seq;
	/** highest seq culled from history */
	__u64				scp_hist_seq_culled;

	/**
	 * serialize the following fields, used for processing requests
	 * sent to this portal
	 */
	spinlock_t			scp_req_lock __cfs_cacheline_aligned;
	/** # reqs in either of the NRS heads below */
	/** # reqs being served */
	int				scp_nreqs_active;
	/** # HPreqs being served */
	int				scp_nhreqs_active;
	/** # hp requests handled */
	int				scp_hreq_count;

	/** NRS head for regular requests */
	struct ptlrpc_nrs		scp_nrs_reg;
	/** NRS head for HP requests; this is only valid for services that can
	 *  handle HP requests
	 */
	struct ptlrpc_nrs	       *scp_nrs_hp;

	/** AT stuff */
	/** @{ */
	/**
	 * serialize the following fields, used for changes on
	 * adaptive timeout
	 */
	spinlock_t			scp_at_lock __cfs_cacheline_aligned;
	/** estimated rpc service time */
	struct adaptive_timeout		scp_at_estimate;
	/** reqs waiting for replies */
	struct ptlrpc_at_array		scp_at_array;
	/** early reply timer */
	struct timer_list		scp_at_timer;
	/** debug */
	unsigned long			scp_at_checktime;
	/** check early replies */
	unsigned			scp_at_check;
	/** @} */

	/**
	 * serialize the following fields, used for processing
	 * replies for this portal
	 */
	spinlock_t			scp_rep_lock __cfs_cacheline_aligned;
	/** all the active replies */
	struct list_head			scp_rep_active;
	/** List of free reply_states */
	struct list_head			scp_rep_idle;
	/** waitq to run, when adding stuff to srv_free_rs_list */
	wait_queue_head_t			scp_rep_waitq;
	/** # 'difficult' replies */
	atomic_t			scp_nreps_difficult;
};

#define ptlrpc_service_for_each_part(part, i, svc)			\
	for (i = 0;							\
	     i < (svc)->srv_ncpts &&					\
	     (svc)->srv_parts &&					\
	     ((part) = (svc)->srv_parts[i]); i++)

/**
 * Declaration of ptlrpcd control structure
 */
struct ptlrpcd_ctl {
	/**
	 * Ptlrpc thread control flags (LIOD_START, LIOD_STOP, LIOD_FORCE)
	 */
	unsigned long			pc_flags;
	/**
	 * Thread lock protecting structure fields.
	 */
	spinlock_t			pc_lock;
	/**
	 * Start completion.
	 */
	struct completion		pc_starting;
	/**
	 * Stop completion.
	 */
	struct completion		pc_finishing;
	/**
	 * Thread requests set.
	 */
	struct ptlrpc_request_set  *pc_set;
	/**
	 * Thread name used in kthread_run()
	 */
	char			pc_name[16];
	/**
	 * CPT the thread is bound on.
	 */
	int				pc_cpt;
	/**
	 * Index of ptlrpcd thread in the array.
	 */
	int				pc_index;
	/**
	 * Pointer to the array of partners' ptlrpcd_ctl structure.
	 */
	struct ptlrpcd_ctl	**pc_partners;
	/**
	 * Number of the ptlrpcd's partners.
	 */
	int				pc_npartners;
	/**
	 * Record the partner index to be processed next.
	 */
	int			 pc_cursor;
	/**
	 * Error code if the thread failed to fully start.
	 */
	int				pc_error;
};

/* Bits for pc_flags */
enum ptlrpcd_ctl_flags {
	/**
	 * Ptlrpc thread start flag.
	 */
	LIOD_START       = 1 << 0,
	/**
	 * Ptlrpc thread stop flag.
	 */
	LIOD_STOP	= 1 << 1,
	/**
	 * Ptlrpc thread force flag (only stop force so far).
	 * This will cause aborting any inflight rpcs handled
	 * by thread if LIOD_STOP is specified.
	 */
	LIOD_FORCE       = 1 << 2,
	/**
	 * This is a recovery ptlrpc thread.
	 */
	LIOD_RECOVERY    = 1 << 3,
};

/**
 * \addtogroup nrs
 * @{
 *
 * Service compatibility function; the policy is compatible with all services.
 *
 * \param[in] svc  The service the policy is attempting to register with.
 * \param[in] desc The policy descriptor
 *
 * \retval true The policy is compatible with the service
 *
 * \see ptlrpc_nrs_pol_desc::pd_compat()
 */
static inline bool nrs_policy_compat_all(const struct ptlrpc_service *svc,
					 const struct ptlrpc_nrs_pol_desc *desc)
{
	return true;
}

/**
 * Service compatibility function; the policy is compatible with only a specific
 * service which is identified by its human-readable name at
 * ptlrpc_service::srv_name.
 *
 * \param[in] svc  The service the policy is attempting to register with.
 * \param[in] desc The policy descriptor
 *
 * \retval false The policy is not compatible with the service
 * \retval true	 The policy is compatible with the service
 *
 * \see ptlrpc_nrs_pol_desc::pd_compat()
 */
static inline bool nrs_policy_compat_one(const struct ptlrpc_service *svc,
					 const struct ptlrpc_nrs_pol_desc *desc)
{
	return strcmp(svc->srv_name, desc->pd_compat_svc_name) == 0;
}

/** @} nrs */

/* ptlrpc/events.c */
extern struct lnet_handle_eq ptlrpc_eq_h;
int ptlrpc_uuid_to_peer(struct obd_uuid *uuid,
			struct lnet_process_id *peer, lnet_nid_t *self);
/**
 * These callbacks are invoked by LNet when something happened to
 * underlying buffer
 * @{
 */
void request_out_callback(struct lnet_event *ev);
void reply_in_callback(struct lnet_event *ev);
void client_bulk_callback(struct lnet_event *ev);
void request_in_callback(struct lnet_event *ev);
void reply_out_callback(struct lnet_event *ev);
/** @} */

/* ptlrpc/connection.c */
struct ptlrpc_connection *ptlrpc_connection_get(struct lnet_process_id peer,
						lnet_nid_t self,
						struct obd_uuid *uuid);
int ptlrpc_connection_put(struct ptlrpc_connection *c);
struct ptlrpc_connection *ptlrpc_connection_addref(struct ptlrpc_connection *);
int ptlrpc_connection_init(void);
void ptlrpc_connection_fini(void);

/* ptlrpc/niobuf.c */
/**
 * Actual interfacing with LNet to put/get/register/unregister stuff
 * @{
 */

int ptlrpc_unregister_bulk(struct ptlrpc_request *req, int async);

static inline int ptlrpc_client_bulk_active(struct ptlrpc_request *req)
{
	struct ptlrpc_bulk_desc *desc;
	int		      rc;

	desc = req->rq_bulk;

	if (req->rq_bulk_deadline > ktime_get_real_seconds())
		return 1;

	if (!desc)
		return 0;

	spin_lock(&desc->bd_lock);
	rc = desc->bd_md_count;
	spin_unlock(&desc->bd_lock);
	return rc;
}

#define PTLRPC_REPLY_MAYBE_DIFFICULT 0x01
#define PTLRPC_REPLY_EARLY	   0x02
int ptlrpc_send_reply(struct ptlrpc_request *req, int flags);
int ptlrpc_reply(struct ptlrpc_request *req);
int ptlrpc_send_error(struct ptlrpc_request *req, int difficult);
int ptlrpc_error(struct ptlrpc_request *req);
int ptlrpc_at_get_net_latency(struct ptlrpc_request *req);
int ptl_send_rpc(struct ptlrpc_request *request, int noreply);
int ptlrpc_register_rqbd(struct ptlrpc_request_buffer_desc *rqbd);
/** @} */

/* ptlrpc/client.c */
/**
 * Client-side portals API. Everything to send requests, receive replies,
 * request queues, request management, etc.
 * @{
 */
void ptlrpc_request_committed(struct ptlrpc_request *req, int force);

void ptlrpc_init_client(int req_portal, int rep_portal, char *name,
			struct ptlrpc_client *);
struct ptlrpc_connection *ptlrpc_uuid_to_connection(struct obd_uuid *uuid);

int ptlrpc_queue_wait(struct ptlrpc_request *req);
int ptlrpc_replay_req(struct ptlrpc_request *req);
void ptlrpc_abort_inflight(struct obd_import *imp);
void ptlrpc_abort_set(struct ptlrpc_request_set *set);

struct ptlrpc_request_set *ptlrpc_prep_set(void);
struct ptlrpc_request_set *ptlrpc_prep_fcset(int max, set_producer_func func,
					     void *arg);
int ptlrpc_check_set(const struct lu_env *env, struct ptlrpc_request_set *set);
int ptlrpc_set_wait(struct ptlrpc_request_set *);
void ptlrpc_mark_interrupted(struct ptlrpc_request *req);
void ptlrpc_set_destroy(struct ptlrpc_request_set *);
void ptlrpc_set_add_req(struct ptlrpc_request_set *, struct ptlrpc_request *);

void ptlrpc_free_rq_pool(struct ptlrpc_request_pool *pool);
int ptlrpc_add_rqs_to_pool(struct ptlrpc_request_pool *pool, int num_rq);

struct ptlrpc_request_pool *
ptlrpc_init_rq_pool(int, int,
		    int (*populate_pool)(struct ptlrpc_request_pool *, int));

void ptlrpc_at_set_req_timeout(struct ptlrpc_request *req);
struct ptlrpc_request *ptlrpc_request_alloc(struct obd_import *imp,
					    const struct req_format *format);
struct ptlrpc_request *ptlrpc_request_alloc_pool(struct obd_import *imp,
						 struct ptlrpc_request_pool *,
						 const struct req_format *);
void ptlrpc_request_free(struct ptlrpc_request *request);
int ptlrpc_request_pack(struct ptlrpc_request *request,
			__u32 version, int opcode);
struct ptlrpc_request *ptlrpc_request_alloc_pack(struct obd_import *,
						 const struct req_format *,
						 __u32, int);
int ptlrpc_request_bufs_pack(struct ptlrpc_request *request,
			     __u32 version, int opcode, char **bufs,
			     struct ptlrpc_cli_ctx *ctx);
void ptlrpc_req_finished(struct ptlrpc_request *request);
struct ptlrpc_request *ptlrpc_request_addref(struct ptlrpc_request *req);
struct ptlrpc_bulk_desc *ptlrpc_prep_bulk_imp(struct ptlrpc_request *req,
					      unsigned int nfrags,
					      unsigned int max_brw,
					      unsigned int type,
					      unsigned int portal,
					      const struct ptlrpc_bulk_frag_ops *ops);

int ptlrpc_prep_bulk_frag(struct ptlrpc_bulk_desc *desc,
			  void *frag, int len);
void __ptlrpc_prep_bulk_page(struct ptlrpc_bulk_desc *desc,
			     struct page *page, int pageoffset, int len,
			     int pin);
static inline void ptlrpc_prep_bulk_page_pin(struct ptlrpc_bulk_desc *desc,
					     struct page *page, int pageoffset,
					     int len)
{
	__ptlrpc_prep_bulk_page(desc, page, pageoffset, len, 1);
}

static inline void ptlrpc_prep_bulk_page_nopin(struct ptlrpc_bulk_desc *desc,
					       struct page *page, int pageoffset,
					       int len)
{
	__ptlrpc_prep_bulk_page(desc, page, pageoffset, len, 0);
}

void ptlrpc_free_bulk(struct ptlrpc_bulk_desc *bulk);

static inline void ptlrpc_release_bulk_page_pin(struct ptlrpc_bulk_desc *desc)
{
	int i;

	for (i = 0; i < desc->bd_iov_count ; i++)
		put_page(BD_GET_KIOV(desc, i).bv_page);
}

void ptlrpc_retain_replayable_request(struct ptlrpc_request *req,
				      struct obd_import *imp);
__u64 ptlrpc_next_xid(void);
__u64 ptlrpc_sample_next_xid(void);
__u64 ptlrpc_req_xid(struct ptlrpc_request *request);

/* Set of routines to run a function in ptlrpcd context */
void *ptlrpcd_alloc_work(struct obd_import *imp,
			 int (*cb)(const struct lu_env *, void *), void *data);
void ptlrpcd_destroy_work(void *handler);
int ptlrpcd_queue_work(void *handler);

/** @} */
struct ptlrpc_service_buf_conf {
	/* nbufs is buffers # to allocate when growing the pool */
	unsigned int			bc_nbufs;
	/* buffer size to post */
	unsigned int			bc_buf_size;
	/* portal to listed for requests on */
	unsigned int			bc_req_portal;
	/* portal of where to send replies to */
	unsigned int			bc_rep_portal;
	/* maximum request size to be accepted for this service */
	unsigned int			bc_req_max_size;
	/* maximum reply size this service can ever send */
	unsigned int			bc_rep_max_size;
};

struct ptlrpc_service_thr_conf {
	/* threadname should be 8 characters or less - 6 will be added on */
	char				*tc_thr_name;
	/* threads increasing factor for each CPU */
	unsigned int			tc_thr_factor;
	/* service threads # to start on each partition while initializing */
	unsigned int			tc_nthrs_init;
	/*
	 * low water of threads # upper-limit on each partition while running,
	 * service availability may be impacted if threads number is lower
	 * than this value. It can be ZERO if the service doesn't require
	 * CPU affinity or there is only one partition.
	 */
	unsigned int			tc_nthrs_base;
	/* "soft" limit for total threads number */
	unsigned int			tc_nthrs_max;
	/* user specified threads number, it will be validated due to
	 * other members of this structure.
	 */
	unsigned int			tc_nthrs_user;
	/* set NUMA node affinity for service threads */
	unsigned int			tc_cpu_affinity;
	/* Tags for lu_context associated with service thread */
	__u32				tc_ctx_tags;
};

struct ptlrpc_service_cpt_conf {
	struct cfs_cpt_table		*cc_cptable;
	/* string pattern to describe CPTs for a service */
	char				*cc_pattern;
};

struct ptlrpc_service_conf {
	/* service name */
	char				*psc_name;
	/* soft watchdog timeout multiplifier to print stuck service traces */
	unsigned int			psc_watchdog_factor;
	/* buffer information */
	struct ptlrpc_service_buf_conf	psc_buf;
	/* thread information */
	struct ptlrpc_service_thr_conf	psc_thr;
	/* CPU partition information */
	struct ptlrpc_service_cpt_conf	psc_cpt;
	/* function table */
	struct ptlrpc_service_ops	psc_ops;
};

/* ptlrpc/service.c */
/**
 * Server-side services API. Register/unregister service, request state
 * management, service thread management
 *
 * @{
 */
void ptlrpc_dispatch_difficult_reply(struct ptlrpc_reply_state *rs);
void ptlrpc_schedule_difficult_reply(struct ptlrpc_reply_state *rs);
struct ptlrpc_service *ptlrpc_register_service(struct ptlrpc_service_conf *conf,
					       struct kset *parent,
					       struct dentry *debugfs_entry);

int ptlrpc_start_threads(struct ptlrpc_service *svc);
int ptlrpc_unregister_service(struct ptlrpc_service *service);

int ptlrpc_hr_init(void);
void ptlrpc_hr_fini(void);

/** @} */

/* ptlrpc/import.c */
/**
 * Import API
 * @{
 */
int ptlrpc_connect_import(struct obd_import *imp);
int ptlrpc_init_import(struct obd_import *imp);
int ptlrpc_disconnect_import(struct obd_import *imp, int noclose);
int ptlrpc_import_recovery_state_machine(struct obd_import *imp);

/* ptlrpc/pack_generic.c */
int ptlrpc_reconnect_import(struct obd_import *imp);
/** @} */

/**
 * ptlrpc msg buffer and swab interface
 *
 * @{
 */
int ptlrpc_buf_need_swab(struct ptlrpc_request *req, const int inout,
			 u32 index);
void ptlrpc_buf_set_swabbed(struct ptlrpc_request *req, const int inout,
			    u32 index);
int ptlrpc_unpack_rep_msg(struct ptlrpc_request *req, int len);
int ptlrpc_unpack_req_msg(struct ptlrpc_request *req, int len);

void lustre_init_msg_v2(struct lustre_msg_v2 *msg, int count, __u32 *lens,
			char **bufs);
int lustre_pack_request(struct ptlrpc_request *, __u32 magic, int count,
			__u32 *lens, char **bufs);
int lustre_pack_reply(struct ptlrpc_request *, int count, __u32 *lens,
		      char **bufs);
int lustre_pack_reply_v2(struct ptlrpc_request *req, int count,
			 __u32 *lens, char **bufs, int flags);
#define LPRFL_EARLY_REPLY 1
int lustre_pack_reply_flags(struct ptlrpc_request *, int count, __u32 *lens,
			    char **bufs, int flags);
int lustre_shrink_msg(struct lustre_msg *msg, int segment,
		      unsigned int newlen, int move_data);
void lustre_free_reply_state(struct ptlrpc_reply_state *rs);
int __lustre_unpack_msg(struct lustre_msg *m, int len);
u32 lustre_msg_hdr_size(__u32 magic, u32 count);
u32 lustre_msg_size(__u32 magic, int count, __u32 *lengths);
u32 lustre_msg_size_v2(int count, __u32 *lengths);
u32 lustre_packed_msg_size(struct lustre_msg *msg);
u32 lustre_msg_early_size(void);
void *lustre_msg_buf_v2(struct lustre_msg_v2 *m, u32 n, u32 min_size);
void *lustre_msg_buf(struct lustre_msg *m, u32 n, u32 minlen);
u32 lustre_msg_buflen(struct lustre_msg *m, u32 n);
u32 lustre_msg_bufcount(struct lustre_msg *m);
char *lustre_msg_string(struct lustre_msg *m, u32 n, u32 max_len);
__u32 lustre_msghdr_get_flags(struct lustre_msg *msg);
void lustre_msghdr_set_flags(struct lustre_msg *msg, __u32 flags);
__u32 lustre_msg_get_flags(struct lustre_msg *msg);
void lustre_msg_add_flags(struct lustre_msg *msg, u32 flags);
void lustre_msg_set_flags(struct lustre_msg *msg, u32 flags);
void lustre_msg_clear_flags(struct lustre_msg *msg, u32 flags);
__u32 lustre_msg_get_op_flags(struct lustre_msg *msg);
void lustre_msg_add_op_flags(struct lustre_msg *msg, u32 flags);
struct lustre_handle *lustre_msg_get_handle(struct lustre_msg *msg);
__u32 lustre_msg_get_type(struct lustre_msg *msg);
void lustre_msg_add_version(struct lustre_msg *msg, u32 version);
__u32 lustre_msg_get_opc(struct lustre_msg *msg);
__u16 lustre_msg_get_tag(struct lustre_msg *msg);
__u64 lustre_msg_get_last_committed(struct lustre_msg *msg);
__u64 *lustre_msg_get_versions(struct lustre_msg *msg);
__u64 lustre_msg_get_transno(struct lustre_msg *msg);
__u64 lustre_msg_get_slv(struct lustre_msg *msg);
__u32 lustre_msg_get_limit(struct lustre_msg *msg);
void lustre_msg_set_slv(struct lustre_msg *msg, __u64 slv);
void lustre_msg_set_limit(struct lustre_msg *msg, __u64 limit);
int lustre_msg_get_status(struct lustre_msg *msg);
__u32 lustre_msg_get_conn_cnt(struct lustre_msg *msg);
__u32 lustre_msg_get_magic(struct lustre_msg *msg);
__u32 lustre_msg_get_timeout(struct lustre_msg *msg);
__u32 lustre_msg_get_service_time(struct lustre_msg *msg);
__u32 lustre_msg_get_cksum(struct lustre_msg *msg);
__u32 lustre_msg_calc_cksum(struct lustre_msg *msg);
void lustre_msg_set_handle(struct lustre_msg *msg,
			   struct lustre_handle *handle);
void lustre_msg_set_type(struct lustre_msg *msg, __u32 type);
void lustre_msg_set_opc(struct lustre_msg *msg, __u32 opc);
void lustre_msg_set_last_xid(struct lustre_msg *msg, u64 last_xid);
void lustre_msg_set_tag(struct lustre_msg *msg, __u16 tag);
void lustre_msg_set_versions(struct lustre_msg *msg, __u64 *versions);
void lustre_msg_set_transno(struct lustre_msg *msg, __u64 transno);
void lustre_msg_set_status(struct lustre_msg *msg, __u32 status);
void lustre_msg_set_conn_cnt(struct lustre_msg *msg, __u32 conn_cnt);
void ptlrpc_request_set_replen(struct ptlrpc_request *req);
void lustre_msg_set_timeout(struct lustre_msg *msg, __u32 timeout);
void lustre_msg_set_service_time(struct lustre_msg *msg, __u32 service_time);
void lustre_msg_set_jobid(struct lustre_msg *msg, char *jobid);
void lustre_msg_set_cksum(struct lustre_msg *msg, __u32 cksum);
void lustre_msg_set_mbits(struct lustre_msg *msg, u64 mbits);

static inline void
lustre_shrink_reply(struct ptlrpc_request *req, int segment,
		    unsigned int newlen, int move_data)
{
	LASSERT(req->rq_reply_state);
	LASSERT(req->rq_repmsg);
	req->rq_replen = lustre_shrink_msg(req->rq_repmsg, segment,
					   newlen, move_data);
}

#ifdef CONFIG_LUSTRE_TRANSLATE_ERRNOS

static inline int ptlrpc_status_hton(int h)
{
	/*
	 * Positive errnos must be network errnos, such as LUSTRE_EDEADLK,
	 * ELDLM_LOCK_ABORTED, etc.
	 */
	if (h < 0)
		return -lustre_errno_hton(-h);
	else
		return h;
}

static inline int ptlrpc_status_ntoh(int n)
{
	/*
	 * See the comment in ptlrpc_status_hton().
	 */
	if (n < 0)
		return -lustre_errno_ntoh(-n);
	else
		return n;
}

#else

#define ptlrpc_status_hton(h) (h)
#define ptlrpc_status_ntoh(n) (n)

#endif
/** @} */

/** Change request phase of \a req to \a new_phase */
static inline void
ptlrpc_rqphase_move(struct ptlrpc_request *req, enum rq_phase new_phase)
{
	if (req->rq_phase == new_phase)
		return;

	if (new_phase == RQ_PHASE_UNREG_RPC ||
	    new_phase == RQ_PHASE_UNREG_BULK) {
		/* No embedded unregistering phases */
		if (req->rq_phase == RQ_PHASE_UNREG_RPC ||
		    req->rq_phase == RQ_PHASE_UNREG_BULK)
			return;

		req->rq_next_phase = req->rq_phase;
		if (req->rq_import)
			atomic_inc(&req->rq_import->imp_unregistering);
	}

	if (req->rq_phase == RQ_PHASE_UNREG_RPC ||
	    req->rq_phase == RQ_PHASE_UNREG_BULK) {
		if (req->rq_import)
			atomic_dec(&req->rq_import->imp_unregistering);
	}

	DEBUG_REQ(D_INFO, req, "move req \"%s\" -> \"%s\"",
		  ptlrpc_rqphase2str(req), ptlrpc_phase2str(new_phase));

	req->rq_phase = new_phase;
}

/**
 * Returns true if request \a req got early reply and hard deadline is not met
 */
static inline int
ptlrpc_client_early(struct ptlrpc_request *req)
{
	return req->rq_early;
}

/**
 * Returns true if we got real reply from server for this request
 */
static inline int
ptlrpc_client_replied(struct ptlrpc_request *req)
{
	if (req->rq_reply_deadline > ktime_get_real_seconds())
		return 0;
	return req->rq_replied;
}

/** Returns true if request \a req is in process of receiving server reply */
static inline int
ptlrpc_client_recv(struct ptlrpc_request *req)
{
	if (req->rq_reply_deadline > ktime_get_real_seconds())
		return 1;
	return req->rq_receiving_reply;
}

static inline int
ptlrpc_client_recv_or_unlink(struct ptlrpc_request *req)
{
	int rc;

	spin_lock(&req->rq_lock);
	if (req->rq_reply_deadline > ktime_get_real_seconds()) {
		spin_unlock(&req->rq_lock);
		return 1;
	}
	if (req->rq_req_deadline > ktime_get_real_seconds()) {
		spin_unlock(&req->rq_lock);
		return 1;
	}
	rc = !req->rq_req_unlinked || !req->rq_reply_unlinked ||
	     req->rq_receiving_reply;
	spin_unlock(&req->rq_lock);
	return rc;
}

static inline void
ptlrpc_client_wake_req(struct ptlrpc_request *req)
{
	if (!req->rq_set)
		wake_up(&req->rq_reply_waitq);
	else
		wake_up(&req->rq_set->set_waitq);
}

static inline void
ptlrpc_rs_addref(struct ptlrpc_reply_state *rs)
{
	LASSERT(atomic_read(&rs->rs_refcount) > 0);
	atomic_inc(&rs->rs_refcount);
}

static inline void
ptlrpc_rs_decref(struct ptlrpc_reply_state *rs)
{
	LASSERT(atomic_read(&rs->rs_refcount) > 0);
	if (atomic_dec_and_test(&rs->rs_refcount))
		lustre_free_reply_state(rs);
}

/* Should only be called once per req */
static inline void ptlrpc_req_drop_rs(struct ptlrpc_request *req)
{
	if (!req->rq_reply_state)
		return; /* shouldn't occur */
	ptlrpc_rs_decref(req->rq_reply_state);
	req->rq_reply_state = NULL;
	req->rq_repmsg = NULL;
}

static inline __u32 lustre_request_magic(struct ptlrpc_request *req)
{
	return lustre_msg_get_magic(req->rq_reqmsg);
}

static inline int ptlrpc_req_get_repsize(struct ptlrpc_request *req)
{
	switch (req->rq_reqmsg->lm_magic) {
	case LUSTRE_MSG_MAGIC_V2:
		return req->rq_reqmsg->lm_repsize;
	default:
		LASSERTF(0, "incorrect message magic: %08x\n",
			 req->rq_reqmsg->lm_magic);
		return -EFAULT;
	}
}

static inline int ptlrpc_send_limit_expired(struct ptlrpc_request *req)
{
	if (req->rq_delay_limit != 0 &&
	    time_before(cfs_time_add(req->rq_queued_time,
				     cfs_time_seconds(req->rq_delay_limit)),
			cfs_time_current())) {
		return 1;
	}
	return 0;
}

static inline int ptlrpc_no_resend(struct ptlrpc_request *req)
{
	if (!req->rq_no_resend && ptlrpc_send_limit_expired(req)) {
		spin_lock(&req->rq_lock);
		req->rq_no_resend = 1;
		spin_unlock(&req->rq_lock);
	}
	return req->rq_no_resend;
}

static inline int
ptlrpc_server_get_timeout(struct ptlrpc_service_part *svcpt)
{
	int at = AT_OFF ? 0 : at_get(&svcpt->scp_at_estimate);

	return svcpt->scp_service->srv_watchdog_factor *
	       max_t(int, at, obd_timeout);
}

static inline struct ptlrpc_service *
ptlrpc_req2svc(struct ptlrpc_request *req)
{
	return req->rq_rqbd->rqbd_svcpt->scp_service;
}

/* ldlm/ldlm_lib.c */
/**
 * Target client logic
 * @{
 */
int client_obd_setup(struct obd_device *obddev, struct lustre_cfg *lcfg);
int client_obd_cleanup(struct obd_device *obddev);
int client_connect_import(const struct lu_env *env,
			  struct obd_export **exp, struct obd_device *obd,
			  struct obd_uuid *cluuid, struct obd_connect_data *,
			  void *localdata);
int client_disconnect_export(struct obd_export *exp);
int client_import_add_conn(struct obd_import *imp, struct obd_uuid *uuid,
			   int priority);
int client_import_del_conn(struct obd_import *imp, struct obd_uuid *uuid);
int client_import_find_conn(struct obd_import *imp, lnet_nid_t peer,
			    struct obd_uuid *uuid);
int import_set_conn_priority(struct obd_import *imp, struct obd_uuid *uuid);
void client_destroy_import(struct obd_import *imp);
/** @} */

/* ptlrpc/pinger.c */
/**
 * Pinger API (client side only)
 * @{
 */
enum timeout_event {
	TIMEOUT_GRANT = 1
};

struct timeout_item;
typedef int (*timeout_cb_t)(struct timeout_item *, void *);
int ptlrpc_pinger_add_import(struct obd_import *imp);
int ptlrpc_pinger_del_import(struct obd_import *imp);
int ptlrpc_add_timeout_client(int time, enum timeout_event event,
			      timeout_cb_t cb, void *data,
			      struct list_head *obd_list);
int ptlrpc_del_timeout_client(struct list_head *obd_list,
			      enum timeout_event event);
struct ptlrpc_request *ptlrpc_prep_ping(struct obd_import *imp);
int ptlrpc_obd_ping(struct obd_device *obd);
void ptlrpc_pinger_ir_up(void);
void ptlrpc_pinger_ir_down(void);
/** @} */
int ptlrpc_pinger_suppress_pings(void);

/* ptlrpc/ptlrpcd.c */
void ptlrpcd_stop(struct ptlrpcd_ctl *pc, int force);
void ptlrpcd_free(struct ptlrpcd_ctl *pc);
void ptlrpcd_wake(struct ptlrpc_request *req);
void ptlrpcd_add_req(struct ptlrpc_request *req);
int ptlrpcd_addref(void);
void ptlrpcd_decref(void);

/* ptlrpc/lproc_ptlrpc.c */
/**
 * procfs output related functions
 * @{
 */
const char *ll_opcode2str(__u32 opcode);
void ptlrpc_lprocfs_register_obd(struct obd_device *obd);
void ptlrpc_lprocfs_unregister_obd(struct obd_device *obd);
void ptlrpc_lprocfs_brw(struct ptlrpc_request *req, int bytes);
/** @} */

/* ptlrpc/llog_client.c */
extern struct llog_operations llog_client_ops;
/** @} net */

#endif
/** @} PtlRPC */