drivers/staging/lustre/lustre/include/lustre_fid.h - nest-learning-thermostat/6.0/linux-imx-4.9.88 - Git at Google

 /*
  * 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) 2011, 2015, Intel Corporation.
  */
 /*
  * This file is part of Lustre, http://www.lustre.org/
  * Lustre is a trademark of Sun Microsystems, Inc.
  *
  * lustre/include/lustre_fid.h
  *
  * Author: Yury Umanets <umka@clusterfs.com>
  */

 #ifndef __LUSTRE_FID_H
 #define __LUSTRE_FID_H

 /** \defgroup fid fid
  *
  * @{
  *
  * http://wiki.old.lustre.org/index.php/Architecture_-_Interoperability_fids_zfs
  * describes the FID namespace and interoperability requirements for FIDs.
  * The important parts of that document are included here for reference.
  *
  * FID
  *   File IDentifier generated by client from range allocated by the SEQuence
  *   service and stored in struct lu_fid. The FID is composed of three parts:
  *   SEQuence, ObjectID, and VERsion.  The SEQ component is a filesystem
  *   unique 64-bit integer, and only one client is ever assigned any SEQ value.
  *   The first 0x400 FID_SEQ_NORMAL [2^33, 2^33 + 0x400] values are reserved
  *   for system use.  The OID component is a 32-bit value generated by the
  *   client on a per-SEQ basis to allow creating many unique FIDs without
  *   communication with the server.  The VER component is a 32-bit value that
  *   distinguishes between different FID instantiations, such as snapshots or
  *   separate subtrees within the filesystem.  FIDs with the same VER field
  *   are considered part of the same namespace.
  *
  * OLD filesystems are those upgraded from Lustre 1.x that predate FIDs, and
  *   MDTs use 32-bit ldiskfs internal inode/generation numbers (IGIFs), while
  *   OSTs use 64-bit Lustre object IDs and generation numbers.
  *
  * NEW filesystems are those formatted since the introduction of FIDs.
  *
  * IGIF
  *   Inode and Generation In FID, a surrogate FID used to globally identify
  *   an existing object on OLD formatted MDT file system. This would only be
  *   used on MDT0 in a DNE filesystem, because there cannot be more than one
  *   MDT in an OLD formatted filesystem. Belongs to sequence in [12, 2^32 - 1]
  *   range, where inode number is stored in SEQ, and inode generation is in OID.
  *   NOTE: This assumes no more than 2^32-1 inodes exist in the MDT filesystem,
  *   which is the maximum possible for an ldiskfs backend.  It also assumes
  *   that the reserved ext3/ext4/ldiskfs inode numbers [0-11] are never visible
  *   to clients, which has always been true.
  *
  * IDIF
  *   object ID In FID, a surrogate FID used to globally identify an existing
  *   OST object on OLD formatted OST file system. Belongs to a sequence in
  *   [2^32, 2^33 - 1]. Sequence number is calculated as:
  *
  *      1 << 32 | (ost_index << 16) | ((objid >> 32) & 0xffff)
  *
  *   that is, SEQ consists of 16-bit OST index, and higher 16 bits of object
  *   ID. The generation of unique SEQ values per OST allows the IDIF FIDs to
  *   be identified in the FLD correctly. The OID field is calculated as:
  *
  *      objid & 0xffffffff
  *
  *   that is, it consists of lower 32 bits of object ID.  For objects within
  *   the IDIF range, object ID extraction will be:
  *
  *      o_id = (fid->f_seq & 0x7fff) << 16 | fid->f_oid;
  *      o_seq = 0;  // formerly group number
  *
  *   NOTE: This assumes that no more than 2^48-1 objects have ever been created
  *   on any OST, and that no more than 65535 OSTs are in use.  Both are very
  *   reasonable assumptions, i.e. an IDIF can uniquely map all objects assuming
  *   a maximum creation rate of 1M objects per second for a maximum of 9 years,
  *   or combinations thereof.
  *
  * OST_MDT0
  *   Surrogate FID used to identify an existing object on OLD formatted OST
  *   filesystem. Belongs to the reserved SEQuence 0, and is used prior to
  *   the introduction of FID-on-OST, at which point IDIF will be used to
  *   identify objects as residing on a specific OST.
  *
  * LLOG
  *   For Lustre Log objects the object sequence 1 is used. This is compatible
  *   with both OLD and NEW namespaces, as this SEQ number is in the
  *   ext3/ldiskfs reserved inode range and does not conflict with IGIF
  *   sequence numbers.
  *
  * ECHO
  *   For testing OST IO performance the object sequence 2 is used. This is
  *   compatible with both OLD and NEW namespaces, as this SEQ number is in
  *   the ext3/ldiskfs reserved inode range and does not conflict with IGIF
  *   sequence numbers.
  *
  * OST_MDT1 .. OST_MAX
  *   For testing with multiple MDTs the object sequence 3 through 9 is used,
  *   allowing direct mapping of MDTs 1 through 7 respectively, for a total
  *   of 8 MDTs including OST_MDT0. This matches the legacy CMD project "group"
  *   mappings. However, this SEQ range is only for testing prior to any
  *   production DNE release, as the objects in this range conflict across all
  *   OSTs, as the OST index is not part of the FID.  For production DNE usage,
  *   OST objects created by MDT1+ will use FID_SEQ_NORMAL FIDs.
  *
  * DLM OST objid to IDIF mapping
  *   For compatibility with existing OLD OST network protocol structures, the
  *   FID must map onto the o_id and o_seq in a manner that ensures existing
  *   objects are identified consistently for IO, as well as onto the LDLM
  *   namespace to ensure IDIFs there is only a single resource name for any
  *   object in the DLM.  The OLD OST object DLM resource mapping is:
  *
  *      resource[] = {o_id, o_seq, 0, 0}; // o_seq == 0 for production releases
  *
  *   The NEW OST object DLM resource mapping is the same for both MDT and OST:
  *
  *      resource[] = {SEQ, OID, VER, HASH};
  *
  *  NOTE: for mapping IDIF values to DLM resource names the o_id may be
  *  larger than the 2^33 reserved sequence numbers for IDIF, so it is possible
  *  for the o_id numbers to overlap FID SEQ numbers in the resource. However,
  *  in all production releases the OLD o_seq field is always zero, and all
  *  valid FID OID values are non-zero, so the lock resources will not collide.
  *  Even so, the MDT and OST resources are also in different LDLM namespaces.
  */

 #include "../../include/linux/libcfs/libcfs.h"
 #include "lustre/lustre_idl.h"

 struct lu_env;
 struct lu_site;
 struct lu_context;
 struct obd_device;
 struct obd_export;

 /* Whole sequences space range and zero range definitions */
 extern const struct lu_seq_range LUSTRE_SEQ_SPACE_RANGE;
 extern const struct lu_seq_range LUSTRE_SEQ_ZERO_RANGE;
 extern const struct lu_fid LUSTRE_BFL_FID;
 extern const struct lu_fid LU_OBF_FID;
 extern const struct lu_fid LU_DOT_LUSTRE_FID;

 enum {
 	/*
 	 * This is how may metadata FIDs may be allocated in one sequence(128k)
 	 */
 	LUSTRE_METADATA_SEQ_MAX_WIDTH = 0x0000000000020000ULL,

 	/*
 	 * This is how many data FIDs could be allocated in one sequence(4B - 1)
 	 */
 	LUSTRE_DATA_SEQ_MAX_WIDTH = 0x00000000FFFFFFFFULL,

 	/*
 	 * How many sequences to allocate to a client at once.
 	 */
 	LUSTRE_SEQ_META_WIDTH = 0x0000000000000001ULL,

 	/*
 	 * seq allocation pool size.
 	 */
 	LUSTRE_SEQ_BATCH_WIDTH = LUSTRE_SEQ_META_WIDTH * 1000,

 	/*
 	 * This is how many sequences may be in one super-sequence allocated to
 	 * MDTs.
 	 */
 	LUSTRE_SEQ_SUPER_WIDTH = ((1ULL << 30ULL) * LUSTRE_SEQ_META_WIDTH)
 };

 enum {
 	/** 2^6 FIDs for OI containers */
 	OSD_OI_FID_OID_BITS     = 6,
 	/** reserve enough FIDs in case we want more in the future */
 	OSD_OI_FID_OID_BITS_MAX = 10,
 };

 /** special OID for local objects */
 enum local_oid {
 	/** \see fld_mod_init */
 	FLD_INDEX_OID		= 3UL,
 	/** \see fid_mod_init */
 	FID_SEQ_CTL_OID		= 4UL,
 	FID_SEQ_SRV_OID		= 5UL,
 	/** \see mdd_mod_init */
 	MDD_ROOT_INDEX_OID	= 6UL, /* deprecated in 2.4 */
 	MDD_ORPHAN_OID		= 7UL, /* deprecated in 2.4 */
 	MDD_LOV_OBJ_OID		= 8UL,
 	MDD_CAPA_KEYS_OID	= 9UL,
 	/** \see mdt_mod_init */
 	LAST_RECV_OID		= 11UL,
 	OSD_FS_ROOT_OID		= 13UL,
 	ACCT_USER_OID		= 15UL,
 	ACCT_GROUP_OID		= 16UL,
 	LFSCK_BOOKMARK_OID	= 17UL,
 	OTABLE_IT_OID		= 18UL,
 	/* These two definitions are obsolete
 	 * OFD_GROUP0_LAST_OID     = 20UL,
 	 * OFD_GROUP4K_LAST_OID    = 20UL+4096,
 	 */
 	OFD_LAST_GROUP_OID	= 4117UL,
 	LLOG_CATALOGS_OID	= 4118UL,
 	MGS_CONFIGS_OID		= 4119UL,
 	OFD_HEALTH_CHECK_OID	= 4120UL,
 	MDD_LOV_OBJ_OSEQ	= 4121UL,
 	LFSCK_NAMESPACE_OID     = 4122UL,
 	REMOTE_PARENT_DIR_OID	= 4123UL,
 	SLAVE_LLOG_CATALOGS_OID	= 4124UL,
 };

 static inline void lu_local_obj_fid(struct lu_fid *fid, __u32 oid)
 {
 	fid->f_seq = FID_SEQ_LOCAL_FILE;
 	fid->f_oid = oid;
 	fid->f_ver = 0;
 }

 static inline void lu_local_name_obj_fid(struct lu_fid *fid, __u32 oid)
 {
 	fid->f_seq = FID_SEQ_LOCAL_NAME;
 	fid->f_oid = oid;
 	fid->f_ver = 0;
 }

 /* For new FS (>= 2.4), the root FID will be changed to
  * [FID_SEQ_ROOT:1:0], for existing FS, (upgraded to 2.4),
  * the root FID will still be IGIF
  */
 static inline int fid_is_root(const struct lu_fid *fid)
 {
 	return unlikely((fid_seq(fid) == FID_SEQ_ROOT &&
 			 fid_oid(fid) == 1));
 }

 static inline int fid_is_dot_lustre(const struct lu_fid *fid)
 {
 	return unlikely(fid_seq(fid) == FID_SEQ_DOT_LUSTRE &&
 			fid_oid(fid) == FID_OID_DOT_LUSTRE);
 }

 static inline int fid_is_obf(const struct lu_fid *fid)
 {
 	return unlikely(fid_seq(fid) == FID_SEQ_DOT_LUSTRE &&
 			fid_oid(fid) == FID_OID_DOT_LUSTRE_OBF);
 }

 static inline int fid_is_otable_it(const struct lu_fid *fid)
 {
 	return unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
 			fid_oid(fid) == OTABLE_IT_OID);
 }

 static inline int fid_is_acct(const struct lu_fid *fid)
 {
 	return fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
 	       (fid_oid(fid) == ACCT_USER_OID ||
 		fid_oid(fid) == ACCT_GROUP_OID);
 }

 static inline int fid_is_quota(const struct lu_fid *fid)
 {
 	return fid_seq(fid) == FID_SEQ_QUOTA ||
 	       fid_seq(fid) == FID_SEQ_QUOTA_GLB;
 }

 static inline int fid_is_namespace_visible(const struct lu_fid *fid)
 {
 	const __u64 seq = fid_seq(fid);

 	/* Here, we cannot distinguish whether the normal FID is for OST
 	 * object or not. It is caller's duty to check more if needed.
 	 */
 	return (!fid_is_last_id(fid) &&
 		(fid_seq_is_norm(seq) || fid_seq_is_igif(seq))) ||
 	       fid_is_root(fid) || fid_is_dot_lustre(fid);
 }

 static inline int fid_seq_in_fldb(__u64 seq)
 {
 	return fid_seq_is_igif(seq) || fid_seq_is_norm(seq) ||
 	       fid_seq_is_root(seq) || fid_seq_is_dot(seq);
 }

 static inline void lu_last_id_fid(struct lu_fid *fid, __u64 seq, __u32 ost_idx)
 {
 	if (fid_seq_is_mdt0(seq)) {
 		fid->f_seq = fid_idif_seq(0, ost_idx);
 	} else {
 		LASSERTF(fid_seq_is_norm(seq) || fid_seq_is_echo(seq) ||
 			 fid_seq_is_idif(seq), "%#llx\n", seq);
 		fid->f_seq = seq;
 	}
 	fid->f_oid = 0;
 	fid->f_ver = 0;
 }

 /* seq client type */
 enum lu_cli_type {
 	LUSTRE_SEQ_METADATA = 1,
 	LUSTRE_SEQ_DATA
 };

 enum lu_mgr_type {
 	LUSTRE_SEQ_SERVER,
 	LUSTRE_SEQ_CONTROLLER
 };

 /* Client sequence manager interface. */
 struct lu_client_seq {
 	/* Sequence-controller export. */
 	struct obd_export      *lcs_exp;
 	struct mutex		lcs_mutex;

 	/*
 	 * Range of allowed for allocation sequences. When using lu_client_seq on
 	 * clients, this contains meta-sequence range. And for servers this
 	 * contains super-sequence range.
 	 */
 	struct lu_seq_range	 lcs_space;

 	/* Seq related proc */
 	struct dentry		*lcs_debugfs_entry;

 	/* This holds last allocated fid in last obtained seq */
 	struct lu_fid	   lcs_fid;

 	/* LUSTRE_SEQ_METADATA or LUSTRE_SEQ_DATA */
 	enum lu_cli_type	lcs_type;

 	/*
 	 * Service uuid, passed from MDT + seq name to form unique seq name to
 	 * use it with procfs.
 	 */
 	char		    lcs_name[LUSTRE_MDT_MAXNAMELEN];

 	/*
 	 * Sequence width, that is how many objects may be allocated in one
 	 * sequence. Default value for it is LUSTRE_SEQ_MAX_WIDTH.
 	 */
 	__u64		   lcs_width;

 	/* wait queue for fid allocation and update indicator */
 	wait_queue_head_t	     lcs_waitq;
 	int		     lcs_update;
 };

 /* Client methods */
 void seq_client_flush(struct lu_client_seq *seq);

 int seq_client_alloc_fid(const struct lu_env *env, struct lu_client_seq *seq,
 			 struct lu_fid *fid);
 /* Fids common stuff */
 int fid_is_local(const struct lu_env *env,
 		 struct lu_site *site, const struct lu_fid *fid);

 enum lu_cli_type;
 int client_fid_init(struct obd_device *obd, struct obd_export *exp,
 		    enum lu_cli_type type);
 int client_fid_fini(struct obd_device *obd);

 /* fid locking */

 struct ldlm_namespace;

 /*
  * Build (DLM) resource name from FID.
  *
  * NOTE: until Lustre 1.8.7/2.1.1 the fid_ver() was packed into name[2],
  * but was moved into name[1] along with the OID to avoid consuming the
  * renaming name[2,3] fields that need to be used for the quota identifier.
  */
 static inline void
 fid_build_reg_res_name(const struct lu_fid *fid, struct ldlm_res_id *res)
 {
 	memset(res, 0, sizeof(*res));
 	res->name[LUSTRE_RES_ID_SEQ_OFF] = fid_seq(fid);
 	res->name[LUSTRE_RES_ID_VER_OID_OFF] = fid_ver_oid(fid);
 }

 /*
  * Return true if resource is for object identified by FID.
  */
 static inline bool fid_res_name_eq(const struct lu_fid *fid,
 				   const struct ldlm_res_id *res)
 {
 	return res->name[LUSTRE_RES_ID_SEQ_OFF] == fid_seq(fid) &&
 	       res->name[LUSTRE_RES_ID_VER_OID_OFF] == fid_ver_oid(fid);
 }

 /*
  * Extract FID from LDLM resource. Reverse of fid_build_reg_res_name().
  */
 static inline void
 fid_extract_from_res_name(struct lu_fid *fid, const struct ldlm_res_id *res)
 {
 	fid->f_seq = res->name[LUSTRE_RES_ID_SEQ_OFF];
 	fid->f_oid = (__u32)(res->name[LUSTRE_RES_ID_VER_OID_OFF]);
 	fid->f_ver = (__u32)(res->name[LUSTRE_RES_ID_VER_OID_OFF] >> 32);
 	LASSERT(fid_res_name_eq(fid, res));
 }

 /*
  * Build (DLM) resource identifier from global quota FID and quota ID.
  */
 static inline void
 fid_build_quota_res_name(const struct lu_fid *glb_fid, union lquota_id *qid,
 			 struct ldlm_res_id *res)
 {
 	fid_build_reg_res_name(glb_fid, res);
 	res->name[LUSTRE_RES_ID_QUOTA_SEQ_OFF] = fid_seq(&qid->qid_fid);
 	res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF] = fid_ver_oid(&qid->qid_fid);
 }

 /*
  * Extract global FID and quota ID from resource name
  */
 static inline void fid_extract_from_quota_res(struct lu_fid *glb_fid,
 					      union lquota_id *qid,
 					      const struct ldlm_res_id *res)
 {
 	fid_extract_from_res_name(glb_fid, res);
 	qid->qid_fid.f_seq = res->name[LUSTRE_RES_ID_QUOTA_SEQ_OFF];
 	qid->qid_fid.f_oid = (__u32)res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF];
 	qid->qid_fid.f_ver =
 		(__u32)(res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF] >> 32);
 }

 static inline void
 fid_build_pdo_res_name(const struct lu_fid *fid, unsigned int hash,
 		       struct ldlm_res_id *res)
 {
 	fid_build_reg_res_name(fid, res);
 	res->name[LUSTRE_RES_ID_HSH_OFF] = hash;
 }

 /**
  * Build DLM resource name from object id & seq, which will be removed
  * finally, when we replace ost_id with FID in data stack.
  *
  * Currently, resid from the old client, whose res[0] = object_id,
  * res[1] = object_seq, is just opposite with Metatdata
  * resid, where, res[0] = fid->f_seq, res[1] = fid->f_oid.
  * To unify the resid identification, we will reverse the data
  * resid to keep it same with Metadata resid, i.e.
  *
  * For resid from the old client,
  *    res[0] = objid,  res[1] = 0, still keep the original order,
  *    for compatibility.
  *
  * For new resid
  *    res will be built from normal FID directly, i.e. res[0] = f_seq,
  *    res[1] = f_oid + f_ver.
  */
 static inline void ostid_build_res_name(const struct ost_id *oi,
 					struct ldlm_res_id *name)
 {
 	memset(name, 0, sizeof(*name));
 	if (fid_seq_is_mdt0(ostid_seq(oi))) {
 		name->name[LUSTRE_RES_ID_SEQ_OFF] = ostid_id(oi);
 		name->name[LUSTRE_RES_ID_VER_OID_OFF] = ostid_seq(oi);
 	} else {
 		fid_build_reg_res_name(&oi->oi_fid, name);
 	}
 }

 /**
  * Return true if the resource is for the object identified by this id & group.
  */
 static inline int ostid_res_name_eq(const struct ost_id *oi,
 				    const struct ldlm_res_id *name)
 {
 	/* Note: it is just a trick here to save some effort, probably the
 	 * correct way would be turn them into the FID and compare
 	 */
 	if (fid_seq_is_mdt0(ostid_seq(oi))) {
 		return name->name[LUSTRE_RES_ID_SEQ_OFF] == ostid_id(oi) &&
 		       name->name[LUSTRE_RES_ID_VER_OID_OFF] == ostid_seq(oi);
 	} else {
 		return name->name[LUSTRE_RES_ID_SEQ_OFF] == ostid_seq(oi) &&
 		       name->name[LUSTRE_RES_ID_VER_OID_OFF] == ostid_id(oi);
 	}
 }

 /* The same as osc_build_res_name() */
 static inline void ost_fid_build_resid(const struct lu_fid *fid,
 				       struct ldlm_res_id *resname)
 {
 	if (fid_is_mdt0(fid) || fid_is_idif(fid)) {
 		struct ost_id oi;

 		oi.oi.oi_id = 0; /* gcc 4.7.2 complains otherwise */
 		if (fid_to_ostid(fid, &oi) != 0)
 			return;
 		ostid_build_res_name(&oi, resname);
 	} else {
 		fid_build_reg_res_name(fid, resname);
 	}
 }

 static inline void ost_fid_from_resid(struct lu_fid *fid,
 				      const struct ldlm_res_id *name,
 				      int ost_idx)
 {
 	if (fid_seq_is_mdt0(name->name[LUSTRE_RES_ID_VER_OID_OFF])) {
 		/* old resid */
 		struct ost_id oi;

 		ostid_set_seq(&oi, name->name[LUSTRE_RES_ID_VER_OID_OFF]);
 		ostid_set_id(&oi, name->name[LUSTRE_RES_ID_SEQ_OFF]);
 		ostid_to_fid(fid, &oi, ost_idx);
 	} else {
 		/* new resid */
 		fid_extract_from_res_name(fid, name);
 	}
 }

 /**
  * Flatten 128-bit FID values into a 64-bit value for use as an inode number.
  * For non-IGIF FIDs this starts just over 2^32, and continues without
  * conflict until 2^64, at which point we wrap the high 24 bits of the SEQ
  * into the range where there may not be many OID values in use, to minimize
  * the risk of conflict.
  *
  * Suppose LUSTRE_SEQ_MAX_WIDTH less than (1 << 24) which is currently true,
  * the time between re-used inode numbers is very long - 2^40 SEQ numbers,
  * or about 2^40 client mounts, if clients create less than 2^24 files/mount.
  */
 static inline __u64 fid_flatten(const struct lu_fid *fid)
 {
 	__u64 ino;
 	__u64 seq;

 	if (fid_is_igif(fid)) {
 		ino = lu_igif_ino(fid);
 		return ino;
 	}

 	seq = fid_seq(fid);

 	ino = (seq << 24) + ((seq >> 24) & 0xffffff0000ULL) + fid_oid(fid);

 	return ino ? ino : fid_oid(fid);
 }

 static inline __u32 fid_hash(const struct lu_fid *f, int bits)
 {
 	/* all objects with same id and different versions will belong to same
 	 * collisions list.
 	 */
 	return hash_long(fid_flatten(f), bits);
 }

 /**
  * map fid to 32 bit value for ino on 32bit systems.
  */
 static inline __u32 fid_flatten32(const struct lu_fid *fid)
 {
 	__u32 ino;
 	__u64 seq;

 	if (fid_is_igif(fid)) {
 		ino = lu_igif_ino(fid);
 		return ino;
 	}

 	seq = fid_seq(fid) - FID_SEQ_START;

 	/* Map the high bits of the OID into higher bits of the inode number so
 	 * that inodes generated at about the same time have a reduced chance
 	 * of collisions. This will give a period of 2^12 = 1024 unique clients
 	 * (from SEQ) and up to min(LUSTRE_SEQ_MAX_WIDTH, 2^20) = 128k objects
 	 * (from OID), or up to 128M inodes without collisions for new files.
 	 */
 	ino = ((seq & 0x000fffffULL) << 12) + ((seq >> 8) & 0xfffff000) +
 	       (seq >> (64 - (40 - 8)) & 0xffffff00) +
 	       (fid_oid(fid) & 0xff000fff) + ((fid_oid(fid) & 0x00fff000) << 8);

 	return ino ? ino : fid_oid(fid);
 }

 static inline int lu_fid_diff(const struct lu_fid *fid1,
 			      const struct lu_fid *fid2)
 {
 	LASSERTF(fid_seq(fid1) == fid_seq(fid2), "fid1:"DFID", fid2:"DFID"\n",
 		 PFID(fid1), PFID(fid2));

 	if (fid_is_idif(fid1) && fid_is_idif(fid2))
 		return fid_idif_id(fid1->f_seq, fid1->f_oid, fid1->f_ver) -
 		       fid_idif_id(fid2->f_seq, fid2->f_oid, fid2->f_ver);

 	return fid_oid(fid1) - fid_oid(fid2);
 }

 #define LUSTRE_SEQ_SRV_NAME "seq_srv"
 #define LUSTRE_SEQ_CTL_NAME "seq_ctl"

 /* Range common stuff */
 static inline void range_cpu_to_le(struct lu_seq_range *dst, const struct lu_seq_range *src)
 {
 	dst->lsr_start = cpu_to_le64(src->lsr_start);
 	dst->lsr_end = cpu_to_le64(src->lsr_end);
 	dst->lsr_index = cpu_to_le32(src->lsr_index);
 	dst->lsr_flags = cpu_to_le32(src->lsr_flags);
 }

 static inline void range_le_to_cpu(struct lu_seq_range *dst, const struct lu_seq_range *src)
 {
 	dst->lsr_start = le64_to_cpu(src->lsr_start);
 	dst->lsr_end = le64_to_cpu(src->lsr_end);
 	dst->lsr_index = le32_to_cpu(src->lsr_index);
 	dst->lsr_flags = le32_to_cpu(src->lsr_flags);
 }

 static inline void range_cpu_to_be(struct lu_seq_range *dst, const struct lu_seq_range *src)
 {
 	dst->lsr_start = cpu_to_be64(src->lsr_start);
 	dst->lsr_end = cpu_to_be64(src->lsr_end);
 	dst->lsr_index = cpu_to_be32(src->lsr_index);
 	dst->lsr_flags = cpu_to_be32(src->lsr_flags);
 }

 static inline void range_be_to_cpu(struct lu_seq_range *dst, const struct lu_seq_range *src)
 {
 	dst->lsr_start = be64_to_cpu(src->lsr_start);
 	dst->lsr_end = be64_to_cpu(src->lsr_end);
 	dst->lsr_index = be32_to_cpu(src->lsr_index);
 	dst->lsr_flags = be32_to_cpu(src->lsr_flags);
 }

 /** @} fid */

 #endif /* __LUSTRE_FID_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) 2011, 2015, Intel Corporation.
	*/
	/*
	* This file is part of Lustre, http://www.lustre.org/
	* Lustre is a trademark of Sun Microsystems, Inc.
	*
	* lustre/include/lustre_fid.h
	*
	* Author: Yury Umanets <umka@clusterfs.com>
	*/

	#ifndef __LUSTRE_FID_H
	#define __LUSTRE_FID_H

	/** \defgroup fid fid
	*
	* @{
	*
	* http://wiki.old.lustre.org/index.php/Architecture_-_Interoperability_fids_zfs
	* describes the FID namespace and interoperability requirements for FIDs.
	* The important parts of that document are included here for reference.
	*
	* FID
	* File IDentifier generated by client from range allocated by the SEQuence
	* service and stored in struct lu_fid. The FID is composed of three parts:
	* SEQuence, ObjectID, and VERsion. The SEQ component is a filesystem
	* unique 64-bit integer, and only one client is ever assigned any SEQ value.
	* The first 0x400 FID_SEQ_NORMAL [2^33, 2^33 + 0x400] values are reserved
	* for system use. The OID component is a 32-bit value generated by the
	* client on a per-SEQ basis to allow creating many unique FIDs without
	* communication with the server. The VER component is a 32-bit value that
	* distinguishes between different FID instantiations, such as snapshots or
	* separate subtrees within the filesystem. FIDs with the same VER field
	* are considered part of the same namespace.
	*
	* OLD filesystems are those upgraded from Lustre 1.x that predate FIDs, and
	* MDTs use 32-bit ldiskfs internal inode/generation numbers (IGIFs), while
	* OSTs use 64-bit Lustre object IDs and generation numbers.
	*
	* NEW filesystems are those formatted since the introduction of FIDs.
	*
	* IGIF
	* Inode and Generation In FID, a surrogate FID used to globally identify
	* an existing object on OLD formatted MDT file system. This would only be
	* used on MDT0 in a DNE filesystem, because there cannot be more than one
	* MDT in an OLD formatted filesystem. Belongs to sequence in [12, 2^32 - 1]
	* range, where inode number is stored in SEQ, and inode generation is in OID.
	* NOTE: This assumes no more than 2^32-1 inodes exist in the MDT filesystem,
	* which is the maximum possible for an ldiskfs backend. It also assumes
	* that the reserved ext3/ext4/ldiskfs inode numbers [0-11] are never visible
	* to clients, which has always been true.
	*
	* IDIF
	* object ID In FID, a surrogate FID used to globally identify an existing
	* OST object on OLD formatted OST file system. Belongs to a sequence in
	* [2^32, 2^33 - 1]. Sequence number is calculated as:
	*
	* 1 << 32 \| (ost_index << 16) \| ((objid >> 32) & 0xffff)
	*
	* that is, SEQ consists of 16-bit OST index, and higher 16 bits of object
	* ID. The generation of unique SEQ values per OST allows the IDIF FIDs to
	* be identified in the FLD correctly. The OID field is calculated as:
	*
	* objid & 0xffffffff
	*
	* that is, it consists of lower 32 bits of object ID. For objects within
	* the IDIF range, object ID extraction will be:
	*
	* o_id = (fid->f_seq & 0x7fff) << 16 \| fid->f_oid;
	* o_seq = 0; // formerly group number
	*
	* NOTE: This assumes that no more than 2^48-1 objects have ever been created
	* on any OST, and that no more than 65535 OSTs are in use. Both are very
	* reasonable assumptions, i.e. an IDIF can uniquely map all objects assuming
	* a maximum creation rate of 1M objects per second for a maximum of 9 years,
	* or combinations thereof.
	*
	* OST_MDT0
	* Surrogate FID used to identify an existing object on OLD formatted OST
	* filesystem. Belongs to the reserved SEQuence 0, and is used prior to
	* the introduction of FID-on-OST, at which point IDIF will be used to
	* identify objects as residing on a specific OST.
	*
	* LLOG
	* For Lustre Log objects the object sequence 1 is used. This is compatible
	* with both OLD and NEW namespaces, as this SEQ number is in the
	* ext3/ldiskfs reserved inode range and does not conflict with IGIF
	* sequence numbers.
	*
	* ECHO
	* For testing OST IO performance the object sequence 2 is used. This is
	* compatible with both OLD and NEW namespaces, as this SEQ number is in
	* the ext3/ldiskfs reserved inode range and does not conflict with IGIF
	* sequence numbers.
	*
	* OST_MDT1 .. OST_MAX
	* For testing with multiple MDTs the object sequence 3 through 9 is used,
	* allowing direct mapping of MDTs 1 through 7 respectively, for a total
	* of 8 MDTs including OST_MDT0. This matches the legacy CMD project "group"
	* mappings. However, this SEQ range is only for testing prior to any
	* production DNE release, as the objects in this range conflict across all
	* OSTs, as the OST index is not part of the FID. For production DNE usage,
	* OST objects created by MDT1+ will use FID_SEQ_NORMAL FIDs.
	*
	* DLM OST objid to IDIF mapping
	* For compatibility with existing OLD OST network protocol structures, the
	* FID must map onto the o_id and o_seq in a manner that ensures existing
	* objects are identified consistently for IO, as well as onto the LDLM
	* namespace to ensure IDIFs there is only a single resource name for any
	* object in the DLM. The OLD OST object DLM resource mapping is:
	*
	* resource[] = {o_id, o_seq, 0, 0}; // o_seq == 0 for production releases
	*
	* The NEW OST object DLM resource mapping is the same for both MDT and OST:
	*
	* resource[] = {SEQ, OID, VER, HASH};
	*
	* NOTE: for mapping IDIF values to DLM resource names the o_id may be
	* larger than the 2^33 reserved sequence numbers for IDIF, so it is possible
	* for the o_id numbers to overlap FID SEQ numbers in the resource. However,
	* in all production releases the OLD o_seq field is always zero, and all
	* valid FID OID values are non-zero, so the lock resources will not collide.
	* Even so, the MDT and OST resources are also in different LDLM namespaces.
	*/

	#include "../../include/linux/libcfs/libcfs.h"
	#include "lustre/lustre_idl.h"

	struct lu_env;
	struct lu_site;
	struct lu_context;
	struct obd_device;
	struct obd_export;

	/* Whole sequences space range and zero range definitions */
	extern const struct lu_seq_range LUSTRE_SEQ_SPACE_RANGE;
	extern const struct lu_seq_range LUSTRE_SEQ_ZERO_RANGE;
	extern const struct lu_fid LUSTRE_BFL_FID;
	extern const struct lu_fid LU_OBF_FID;
	extern const struct lu_fid LU_DOT_LUSTRE_FID;

	enum {
	/*
	* This is how may metadata FIDs may be allocated in one sequence(128k)
	*/
	LUSTRE_METADATA_SEQ_MAX_WIDTH = 0x0000000000020000ULL,

	/*
	* This is how many data FIDs could be allocated in one sequence(4B - 1)
	*/
	LUSTRE_DATA_SEQ_MAX_WIDTH = 0x00000000FFFFFFFFULL,

	/*
	* How many sequences to allocate to a client at once.
	*/
	LUSTRE_SEQ_META_WIDTH = 0x0000000000000001ULL,

	/*
	* seq allocation pool size.
	*/
	LUSTRE_SEQ_BATCH_WIDTH = LUSTRE_SEQ_META_WIDTH * 1000,

	/*
	* This is how many sequences may be in one super-sequence allocated to
	* MDTs.
	*/
	LUSTRE_SEQ_SUPER_WIDTH = ((1ULL << 30ULL) * LUSTRE_SEQ_META_WIDTH)
	};

	enum {
	/** 2^6 FIDs for OI containers */
	OSD_OI_FID_OID_BITS = 6,
	/** reserve enough FIDs in case we want more in the future */
	OSD_OI_FID_OID_BITS_MAX = 10,
	};

	/** special OID for local objects */
	enum local_oid {
	/** \see fld_mod_init */
	FLD_INDEX_OID = 3UL,
	/** \see fid_mod_init */
	FID_SEQ_CTL_OID = 4UL,
	FID_SEQ_SRV_OID = 5UL,
	/** \see mdd_mod_init */
	MDD_ROOT_INDEX_OID = 6UL, /* deprecated in 2.4 */
	MDD_ORPHAN_OID = 7UL, /* deprecated in 2.4 */
	MDD_LOV_OBJ_OID = 8UL,
	MDD_CAPA_KEYS_OID = 9UL,
	/** \see mdt_mod_init */
	LAST_RECV_OID = 11UL,
	OSD_FS_ROOT_OID = 13UL,
	ACCT_USER_OID = 15UL,
	ACCT_GROUP_OID = 16UL,
	LFSCK_BOOKMARK_OID = 17UL,
	OTABLE_IT_OID = 18UL,
	/* These two definitions are obsolete
	* OFD_GROUP0_LAST_OID = 20UL,
	* OFD_GROUP4K_LAST_OID = 20UL+4096,
	*/
	OFD_LAST_GROUP_OID = 4117UL,
	LLOG_CATALOGS_OID = 4118UL,
	MGS_CONFIGS_OID = 4119UL,
	OFD_HEALTH_CHECK_OID = 4120UL,
	MDD_LOV_OBJ_OSEQ = 4121UL,
	LFSCK_NAMESPACE_OID = 4122UL,
	REMOTE_PARENT_DIR_OID = 4123UL,
	SLAVE_LLOG_CATALOGS_OID = 4124UL,
	};

	static inline void lu_local_obj_fid(struct lu_fid *fid, __u32 oid)
	{
	fid->f_seq = FID_SEQ_LOCAL_FILE;
	fid->f_oid = oid;
	fid->f_ver = 0;
	}

	static inline void lu_local_name_obj_fid(struct lu_fid *fid, __u32 oid)
	{
	fid->f_seq = FID_SEQ_LOCAL_NAME;
	fid->f_oid = oid;
	fid->f_ver = 0;
	}

	/* For new FS (>= 2.4), the root FID will be changed to
	* [FID_SEQ_ROOT:1:0], for existing FS, (upgraded to 2.4),
	* the root FID will still be IGIF
	*/
	static inline int fid_is_root(const struct lu_fid *fid)
	{
	return unlikely((fid_seq(fid) == FID_SEQ_ROOT &&
	fid_oid(fid) == 1));
	}

	static inline int fid_is_dot_lustre(const struct lu_fid *fid)
	{
	return unlikely(fid_seq(fid) == FID_SEQ_DOT_LUSTRE &&
	fid_oid(fid) == FID_OID_DOT_LUSTRE);
	}

	static inline int fid_is_obf(const struct lu_fid *fid)
	{
	return unlikely(fid_seq(fid) == FID_SEQ_DOT_LUSTRE &&
	fid_oid(fid) == FID_OID_DOT_LUSTRE_OBF);
	}

	static inline int fid_is_otable_it(const struct lu_fid *fid)
	{
	return unlikely(fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
	fid_oid(fid) == OTABLE_IT_OID);
	}

	static inline int fid_is_acct(const struct lu_fid *fid)
	{
	return fid_seq(fid) == FID_SEQ_LOCAL_FILE &&
	(fid_oid(fid) == ACCT_USER_OID \|\|
	fid_oid(fid) == ACCT_GROUP_OID);
	}

	static inline int fid_is_quota(const struct lu_fid *fid)
	{
	return fid_seq(fid) == FID_SEQ_QUOTA \|\|
	fid_seq(fid) == FID_SEQ_QUOTA_GLB;
	}

	static inline int fid_is_namespace_visible(const struct lu_fid *fid)
	{
	const __u64 seq = fid_seq(fid);

	/* Here, we cannot distinguish whether the normal FID is for OST
	* object or not. It is caller's duty to check more if needed.
	*/
	return (!fid_is_last_id(fid) &&
	(fid_seq_is_norm(seq) \|\| fid_seq_is_igif(seq))) \|\|
	fid_is_root(fid) \|\| fid_is_dot_lustre(fid);
	}

	static inline int fid_seq_in_fldb(__u64 seq)
	{
	return fid_seq_is_igif(seq) \|\| fid_seq_is_norm(seq) \|\|
	fid_seq_is_root(seq) \|\| fid_seq_is_dot(seq);
	}

	static inline void lu_last_id_fid(struct lu_fid *fid, __u64 seq, __u32 ost_idx)
	{
	if (fid_seq_is_mdt0(seq)) {
	fid->f_seq = fid_idif_seq(0, ost_idx);
	} else {
	LASSERTF(fid_seq_is_norm(seq) \|\| fid_seq_is_echo(seq) \|\|
	fid_seq_is_idif(seq), "%#llx\n", seq);
	fid->f_seq = seq;
	}
	fid->f_oid = 0;
	fid->f_ver = 0;
	}

	/* seq client type */
	enum lu_cli_type {
	LUSTRE_SEQ_METADATA = 1,
	LUSTRE_SEQ_DATA
	};

	enum lu_mgr_type {
	LUSTRE_SEQ_SERVER,
	LUSTRE_SEQ_CONTROLLER
	};

	/* Client sequence manager interface. */
	struct lu_client_seq {
	/* Sequence-controller export. */
	struct obd_export *lcs_exp;
	struct mutex lcs_mutex;

	/*
	* Range of allowed for allocation sequences. When using lu_client_seq on
	* clients, this contains meta-sequence range. And for servers this
	* contains super-sequence range.
	*/
	struct lu_seq_range lcs_space;

	/* Seq related proc */
	struct dentry *lcs_debugfs_entry;

	/* This holds last allocated fid in last obtained seq */
	struct lu_fid lcs_fid;

	/* LUSTRE_SEQ_METADATA or LUSTRE_SEQ_DATA */
	enum lu_cli_type lcs_type;

	/*
	* Service uuid, passed from MDT + seq name to form unique seq name to
	* use it with procfs.
	*/
	char lcs_name[LUSTRE_MDT_MAXNAMELEN];

	/*
	* Sequence width, that is how many objects may be allocated in one
	* sequence. Default value for it is LUSTRE_SEQ_MAX_WIDTH.
	*/
	__u64 lcs_width;

	/* wait queue for fid allocation and update indicator */
	wait_queue_head_t lcs_waitq;
	int lcs_update;
	};

	/* Client methods */
	void seq_client_flush(struct lu_client_seq *seq);

	int seq_client_alloc_fid(const struct lu_env env, struct lu_client_seq seq,
	struct lu_fid *fid);
	/* Fids common stuff */
	int fid_is_local(const struct lu_env *env,
	struct lu_site site, const struct lu_fid fid);

	enum lu_cli_type;
	int client_fid_init(struct obd_device obd, struct obd_export exp,
	enum lu_cli_type type);
	int client_fid_fini(struct obd_device *obd);

	/* fid locking */

	struct ldlm_namespace;

	/*
	* Build (DLM) resource name from FID.
	*
	* NOTE: until Lustre 1.8.7/2.1.1 the fid_ver() was packed into name[2],
	* but was moved into name[1] along with the OID to avoid consuming the
	* renaming name[2,3] fields that need to be used for the quota identifier.
	*/
	static inline void
	fid_build_reg_res_name(const struct lu_fid fid, struct ldlm_res_id res)
	{
	memset(res, 0, sizeof(*res));
	res->name[LUSTRE_RES_ID_SEQ_OFF] = fid_seq(fid);
	res->name[LUSTRE_RES_ID_VER_OID_OFF] = fid_ver_oid(fid);
	}

	/*
	* Return true if resource is for object identified by FID.
	*/
	static inline bool fid_res_name_eq(const struct lu_fid *fid,
	const struct ldlm_res_id *res)
	{
	return res->name[LUSTRE_RES_ID_SEQ_OFF] == fid_seq(fid) &&
	res->name[LUSTRE_RES_ID_VER_OID_OFF] == fid_ver_oid(fid);
	}

	/*
	* Extract FID from LDLM resource. Reverse of fid_build_reg_res_name().
	*/
	static inline void
	fid_extract_from_res_name(struct lu_fid fid, const struct ldlm_res_id res)
	{
	fid->f_seq = res->name[LUSTRE_RES_ID_SEQ_OFF];
	fid->f_oid = (__u32)(res->name[LUSTRE_RES_ID_VER_OID_OFF]);
	fid->f_ver = (__u32)(res->name[LUSTRE_RES_ID_VER_OID_OFF] >> 32);
	LASSERT(fid_res_name_eq(fid, res));
	}

	/*
	* Build (DLM) resource identifier from global quota FID and quota ID.
	*/
	static inline void
	fid_build_quota_res_name(const struct lu_fid glb_fid, union lquota_id qid,
	struct ldlm_res_id *res)
	{
	fid_build_reg_res_name(glb_fid, res);
	res->name[LUSTRE_RES_ID_QUOTA_SEQ_OFF] = fid_seq(&qid->qid_fid);
	res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF] = fid_ver_oid(&qid->qid_fid);
	}

	/*
	* Extract global FID and quota ID from resource name
	*/
	static inline void fid_extract_from_quota_res(struct lu_fid *glb_fid,
	union lquota_id *qid,
	const struct ldlm_res_id *res)
	{
	fid_extract_from_res_name(glb_fid, res);
	qid->qid_fid.f_seq = res->name[LUSTRE_RES_ID_QUOTA_SEQ_OFF];
	qid->qid_fid.f_oid = (__u32)res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF];
	qid->qid_fid.f_ver =
	(__u32)(res->name[LUSTRE_RES_ID_QUOTA_VER_OID_OFF] >> 32);
	}

	static inline void
	fid_build_pdo_res_name(const struct lu_fid *fid, unsigned int hash,
	struct ldlm_res_id *res)
	{
	fid_build_reg_res_name(fid, res);
	res->name[LUSTRE_RES_ID_HSH_OFF] = hash;
	}

	/**
	* Build DLM resource name from object id & seq, which will be removed
	* finally, when we replace ost_id with FID in data stack.
	*
	* Currently, resid from the old client, whose res[0] = object_id,
	* res[1] = object_seq, is just opposite with Metatdata
	* resid, where, res[0] = fid->f_seq, res[1] = fid->f_oid.
	* To unify the resid identification, we will reverse the data
	* resid to keep it same with Metadata resid, i.e.
	*
	* For resid from the old client,
	* res[0] = objid, res[1] = 0, still keep the original order,
	* for compatibility.
	*
	* For new resid
	* res will be built from normal FID directly, i.e. res[0] = f_seq,
	* res[1] = f_oid + f_ver.
	*/
	static inline void ostid_build_res_name(const struct ost_id *oi,
	struct ldlm_res_id *name)
	{
	memset(name, 0, sizeof(*name));
	if (fid_seq_is_mdt0(ostid_seq(oi))) {
	name->name[LUSTRE_RES_ID_SEQ_OFF] = ostid_id(oi);
	name->name[LUSTRE_RES_ID_VER_OID_OFF] = ostid_seq(oi);
	} else {
	fid_build_reg_res_name(&oi->oi_fid, name);
	}
	}

	/**
	* Return true if the resource is for the object identified by this id & group.
	*/
	static inline int ostid_res_name_eq(const struct ost_id *oi,
	const struct ldlm_res_id *name)
	{
	/* Note: it is just a trick here to save some effort, probably the
	* correct way would be turn them into the FID and compare
	*/
	if (fid_seq_is_mdt0(ostid_seq(oi))) {
	return name->name[LUSTRE_RES_ID_SEQ_OFF] == ostid_id(oi) &&
	name->name[LUSTRE_RES_ID_VER_OID_OFF] == ostid_seq(oi);
	} else {
	return name->name[LUSTRE_RES_ID_SEQ_OFF] == ostid_seq(oi) &&
	name->name[LUSTRE_RES_ID_VER_OID_OFF] == ostid_id(oi);
	}
	}

	/* The same as osc_build_res_name() */
	static inline void ost_fid_build_resid(const struct lu_fid *fid,
	struct ldlm_res_id *resname)
	{
	if (fid_is_mdt0(fid) \|\| fid_is_idif(fid)) {
	struct ost_id oi;

	oi.oi.oi_id = 0; /* gcc 4.7.2 complains otherwise */
	if (fid_to_ostid(fid, &oi) != 0)
	return;
	ostid_build_res_name(&oi, resname);
	} else {
	fid_build_reg_res_name(fid, resname);
	}
	}

	static inline void ost_fid_from_resid(struct lu_fid *fid,
	const struct ldlm_res_id *name,
	int ost_idx)
	{
	if (fid_seq_is_mdt0(name->name[LUSTRE_RES_ID_VER_OID_OFF])) {
	/* old resid */
	struct ost_id oi;

	ostid_set_seq(&oi, name->name[LUSTRE_RES_ID_VER_OID_OFF]);
	ostid_set_id(&oi, name->name[LUSTRE_RES_ID_SEQ_OFF]);
	ostid_to_fid(fid, &oi, ost_idx);
	} else {
	/* new resid */
	fid_extract_from_res_name(fid, name);
	}
	}

	/**
	* Flatten 128-bit FID values into a 64-bit value for use as an inode number.
	* For non-IGIF FIDs this starts just over 2^32, and continues without
	* conflict until 2^64, at which point we wrap the high 24 bits of the SEQ
	* into the range where there may not be many OID values in use, to minimize
	* the risk of conflict.
	*
	* Suppose LUSTRE_SEQ_MAX_WIDTH less than (1 << 24) which is currently true,
	* the time between re-used inode numbers is very long - 2^40 SEQ numbers,
	* or about 2^40 client mounts, if clients create less than 2^24 files/mount.
	*/
	static inline __u64 fid_flatten(const struct lu_fid *fid)
	{
	__u64 ino;
	__u64 seq;

	if (fid_is_igif(fid)) {
	ino = lu_igif_ino(fid);
	return ino;
	}

	seq = fid_seq(fid);

	ino = (seq << 24) + ((seq >> 24) & 0xffffff0000ULL) + fid_oid(fid);

	return ino ? ino : fid_oid(fid);
	}

	static inline __u32 fid_hash(const struct lu_fid *f, int bits)
	{
	/* all objects with same id and different versions will belong to same
	* collisions list.
	*/
	return hash_long(fid_flatten(f), bits);
	}

	/**
	* map fid to 32 bit value for ino on 32bit systems.
	*/
	static inline __u32 fid_flatten32(const struct lu_fid *fid)
	{
	__u32 ino;
	__u64 seq;

	if (fid_is_igif(fid)) {
	ino = lu_igif_ino(fid);
	return ino;
	}

	seq = fid_seq(fid) - FID_SEQ_START;

	/* Map the high bits of the OID into higher bits of the inode number so
	* that inodes generated at about the same time have a reduced chance
	* of collisions. This will give a period of 2^12 = 1024 unique clients
	* (from SEQ) and up to min(LUSTRE_SEQ_MAX_WIDTH, 2^20) = 128k objects
	* (from OID), or up to 128M inodes without collisions for new files.
	*/
	ino = ((seq & 0x000fffffULL) << 12) + ((seq >> 8) & 0xfffff000) +
	(seq >> (64 - (40 - 8)) & 0xffffff00) +
	(fid_oid(fid) & 0xff000fff) + ((fid_oid(fid) & 0x00fff000) << 8);

	return ino ? ino : fid_oid(fid);
	}

	static inline int lu_fid_diff(const struct lu_fid *fid1,
	const struct lu_fid *fid2)
	{
	LASSERTF(fid_seq(fid1) == fid_seq(fid2), "fid1:"DFID", fid2:"DFID"\n",
	PFID(fid1), PFID(fid2));

	if (fid_is_idif(fid1) && fid_is_idif(fid2))
	return fid_idif_id(fid1->f_seq, fid1->f_oid, fid1->f_ver) -
	fid_idif_id(fid2->f_seq, fid2->f_oid, fid2->f_ver);

	return fid_oid(fid1) - fid_oid(fid2);
	}

	#define LUSTRE_SEQ_SRV_NAME "seq_srv"
	#define LUSTRE_SEQ_CTL_NAME "seq_ctl"

	/* Range common stuff */
	static inline void range_cpu_to_le(struct lu_seq_range dst, const struct lu_seq_range src)
	{
	dst->lsr_start = cpu_to_le64(src->lsr_start);
	dst->lsr_end = cpu_to_le64(src->lsr_end);
	dst->lsr_index = cpu_to_le32(src->lsr_index);
	dst->lsr_flags = cpu_to_le32(src->lsr_flags);
	}

	static inline void range_le_to_cpu(struct lu_seq_range dst, const struct lu_seq_range src)
	{
	dst->lsr_start = le64_to_cpu(src->lsr_start);
	dst->lsr_end = le64_to_cpu(src->lsr_end);
	dst->lsr_index = le32_to_cpu(src->lsr_index);
	dst->lsr_flags = le32_to_cpu(src->lsr_flags);
	}

	static inline void range_cpu_to_be(struct lu_seq_range dst, const struct lu_seq_range src)
	{
	dst->lsr_start = cpu_to_be64(src->lsr_start);
	dst->lsr_end = cpu_to_be64(src->lsr_end);
	dst->lsr_index = cpu_to_be32(src->lsr_index);
	dst->lsr_flags = cpu_to_be32(src->lsr_flags);
	}

	static inline void range_be_to_cpu(struct lu_seq_range dst, const struct lu_seq_range src)
	{
	dst->lsr_start = be64_to_cpu(src->lsr_start);
	dst->lsr_end = be64_to_cpu(src->lsr_end);
	dst->lsr_index = be32_to_cpu(src->lsr_index);
	dst->lsr_flags = be32_to_cpu(src->lsr_flags);
	}

	/** @} fid */

	#endif /* __LUSTRE_FID_H */