[ceph.git] / ceph / src / mds / Migrator.h

// -*- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t -*- 
// vim: ts=8 sw=2 smarttab
/*
 * Ceph - scalable distributed file system
 *
 * Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
 *
 * This is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License version 2.1, as published by the Free Software 
 * Foundation.  See file COPYING.
 * 
 * Handles the import and export of  mds authorities and actual cache data.
 * See src/doc/exports.txt for a description.
 */

#ifndef CEPH_MDS_MIGRATOR_H
#define CEPH_MDS_MIGRATOR_H

#include "include/types.h"

#include <map>
#include <list>
#include <set>
using std::map;
using std::list;
using std::set;


class MDSRank;
class CDir;
class CInode;
class CDentry;

class MExportDirDiscover;
class MExportDirDiscoverAck;
class MExportDirCancel;
class MExportDirPrep;
class MExportDirPrepAck;
class MExportDir;
class MExportDirAck;
class MExportDirNotify;
class MExportDirNotifyAck;
class MExportDirFinish;

class MExportCaps;
class MExportCapsAck;
class MGatherCaps;

class EImportStart;

class Migrator {
public:
  // export stages.  used to clean up intelligently if there's a failure.
  const static int EXPORT_CANCELLED	= 0;  // cancelled
  const static int EXPORT_CANCELLING	= 1;  // waiting for cancel notifyacks
  const static int EXPORT_LOCKING	= 2;  // acquiring locks
  const static int EXPORT_DISCOVERING	= 3;  // dest is disovering export dir
  const static int EXPORT_FREEZING	= 4;  // we're freezing the dir tree
  const static int EXPORT_PREPPING	= 5;  // sending dest spanning tree to export bounds
  const static int EXPORT_WARNING	= 6;  // warning bystanders of dir_auth_pending
  const static int EXPORT_EXPORTING	= 7;  // sent actual export, waiting for ack
  const static int EXPORT_LOGGINGFINISH	= 8;  // logging EExportFinish
  const static int EXPORT_NOTIFYING	= 9;  // waiting for notifyacks
  static const char *get_export_statename(int s) {
    switch (s) {
    case EXPORT_CANCELLING: return "cancelling";
    case EXPORT_LOCKING: return "locking";
    case EXPORT_DISCOVERING: return "discovering";
    case EXPORT_FREEZING: return "freezing";
    case EXPORT_PREPPING: return "prepping";
    case EXPORT_WARNING: return "warning";
    case EXPORT_EXPORTING: return "exporting";
    case EXPORT_LOGGINGFINISH: return "loggingfinish";
    case EXPORT_NOTIFYING: return "notifying";
    default: ceph_abort(); return 0;
    }
  }

  // -- imports --
  const static int IMPORT_DISCOVERING   = 1; // waiting for prep
  const static int IMPORT_DISCOVERED    = 2; // waiting for prep
  const static int IMPORT_PREPPING      = 3; // opening dirs on bounds
  const static int IMPORT_PREPPED       = 4; // opened bounds, waiting for import
  const static int IMPORT_LOGGINGSTART  = 5; // got import, logging EImportStart
  const static int IMPORT_ACKING        = 6; // logged EImportStart, sent ack, waiting for finish
  const static int IMPORT_FINISHING     = 7; // sent cap imports, waiting for finish
  const static int IMPORT_ABORTING      = 8; // notifying bystanders of an abort before unfreezing
  static const char *get_import_statename(int s) {
    switch (s) {
    case IMPORT_DISCOVERING: return "discovering";
    case IMPORT_DISCOVERED: return "discovered";
    case IMPORT_PREPPING: return "prepping";
    case IMPORT_PREPPED: return "prepped";
    case IMPORT_LOGGINGSTART: return "loggingstart";
    case IMPORT_ACKING: return "acking";
    case IMPORT_FINISHING: return "finishing";
    case IMPORT_ABORTING: return "aborting";
    default: ceph_abort(); return 0;
    }
  }

  // -- cons --
  Migrator(MDSRank *m, MDCache *c) : mds(m), cache(c) {}


protected:
  // export fun
  struct export_state_t {
    int state;
    mds_rank_t peer;
    uint64_t tid;
    set<mds_rank_t> warning_ack_waiting;
    set<mds_rank_t> notify_ack_waiting;
    map<inodeno_t,map<client_t,Capability::Import> > peer_imported;
    MutationRef mut;
    // for freeze tree deadlock detection
    utime_t last_cum_auth_pins_change;
    int last_cum_auth_pins;
    int num_remote_waiters; // number of remote authpin waiters
    export_state_t() : state(0), peer(0), tid(0), mut(),
		       last_cum_auth_pins(0), num_remote_waiters(0) {}
  };

  map<CDir*, export_state_t>  export_state;

  list<pair<dirfrag_t,mds_rank_t> >  export_queue;

  // import fun
  struct import_state_t {
    int state;
    mds_rank_t peer;
    uint64_t tid;
    set<mds_rank_t> bystanders;
    list<dirfrag_t> bound_ls;
    list<ScatterLock*> updated_scatterlocks;
    map<client_t,entity_inst_t> client_map;
    map<CInode*, map<client_t,Capability::Export> > peer_exports;
    MutationRef mut;
    import_state_t() : state(0), peer(0), tid(0), mut() {}
  };

  map<dirfrag_t, import_state_t>  import_state;

  void handle_export_discover_ack(MExportDirDiscoverAck *m);
  void export_frozen(CDir *dir, uint64_t tid);
  void handle_export_prep_ack(MExportDirPrepAck *m);
  void export_sessions_flushed(CDir *dir, uint64_t tid);
  void export_go(CDir *dir);
  void export_go_synced(CDir *dir, uint64_t tid);
  void export_try_cancel(CDir *dir, bool notify_peer=true);
  void export_cancel_finish(CDir *dir);
  void export_reverse(CDir *dir);
  void export_notify_abort(CDir *dir, set<CDir*>& bounds);
  void handle_export_ack(MExportDirAck *m);
  void export_logged_finish(CDir *dir);
  void handle_export_notify_ack(MExportDirNotifyAck *m);
  void export_finish(CDir *dir);

  void handle_gather_caps(MGatherCaps *m);

  friend class C_MDC_ExportFreeze;
  friend class C_MDS_ExportFinishLogged;
  friend class C_M_ExportGo;
  friend class C_M_ExportSessionsFlushed;
  friend class MigratorContext;
  friend class MigratorLogContext;

  // importer
  void handle_export_discover(MExportDirDiscover *m);
  void handle_export_cancel(MExportDirCancel *m);
  void handle_export_prep(MExportDirPrep *m);
  void handle_export_dir(MExportDir *m);

  void import_reverse_discovering(dirfrag_t df);
  void import_reverse_discovered(dirfrag_t df, CInode *diri);
  void import_reverse_prepping(CDir *dir);
  void import_remove_pins(CDir *dir, set<CDir*>& bounds);
  void import_reverse_unfreeze(CDir *dir);
  void import_reverse_final(CDir *dir);
  void import_notify_abort(CDir *dir, set<CDir*>& bounds);
  void import_notify_finish(CDir *dir, set<CDir*>& bounds);
  void import_logged_start(dirfrag_t df, CDir *dir, mds_rank_t from,
			   map<client_t,entity_inst_t> &imported_client_map,
			   map<client_t,uint64_t>& sseqmap);
  void handle_export_finish(MExportDirFinish *m);

  void handle_export_caps(MExportCaps *m);
  void logged_import_caps(CInode *in,
			  mds_rank_t from,
			  map<CInode*, map<client_t,Capability::Export> >& cap_imports,
			  map<client_t,entity_inst_t>& client_map,
			  map<client_t,uint64_t>& sseqmap);


  friend class C_MDS_ImportDirLoggedStart;
  friend class C_MDS_ImportDirLoggedFinish;
  friend class C_M_LoggedImportCaps;

  // bystander
  void handle_export_notify(MExportDirNotify *m);


public:

  void dispatch(Message*);

  void show_importing();
  void show_exporting();

  int get_num_exporting() const { return export_state.size(); }
  int get_export_queue_size() const { return export_queue.size(); }
  
  // -- status --
  int is_exporting(CDir *dir) const {
    map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
    if (it != export_state.end()) return it->second.state;
    return 0;
  }
  bool is_exporting() const { return !export_state.empty(); }
  int is_importing(dirfrag_t df) const {
    map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
    if (it != import_state.end()) return it->second.state;
    return 0;
  }
  bool is_importing() const { return !import_state.empty(); }

  bool is_ambiguous_import(dirfrag_t df) const {
    map<dirfrag_t, import_state_t>::const_iterator p = import_state.find(df);
    if (p == import_state.end())
      return false;
    if (p->second.state >= IMPORT_LOGGINGSTART &&
	p->second.state < IMPORT_ABORTING)
      return true;
    return false;
  }

  int get_import_state(dirfrag_t df) const {
    map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
    assert(it != import_state.end());
    return it->second.state;
  }
  int get_import_peer(dirfrag_t df) const {
    map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
    assert(it != import_state.end());
    return it->second.peer;
  }

  int get_export_state(CDir *dir) const {
    map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
    assert(it != export_state.end());
    return it->second.state;
  }
  // this returns true if we are export @dir,
  // and are not waiting for @who to be
  // be warned of ambiguous auth.
  // only returns meaningful results during EXPORT_WARNING state.
  bool export_has_warned(CDir *dir, mds_rank_t who) {
    map<CDir*, export_state_t>::iterator it = export_state.find(dir);
    assert(it != export_state.end());
    assert(it->second.state == EXPORT_WARNING);
    return (it->second.warning_ack_waiting.count(who) == 0);
  }

  bool export_has_notified(CDir *dir, mds_rank_t who) const {
    map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
    assert(it != export_state.end());
    assert(it->second.state == EXPORT_NOTIFYING);
    return (it->second.notify_ack_waiting.count(who) == 0);
  }

  void export_freeze_inc_num_waiters(CDir *dir) {
    map<CDir*, export_state_t>::iterator it = export_state.find(dir);
    assert(it != export_state.end());
    it->second.num_remote_waiters++;
  }
  void find_stale_export_freeze();

  // -- misc --
  void handle_mds_failure_or_stop(mds_rank_t who);

  void audit();

  // -- import/export --
  // exporter
  void dispatch_export_dir(MDRequestRef& mdr, int count);
  void export_dir(CDir *dir, mds_rank_t dest);
  void export_empty_import(CDir *dir);

  void export_dir_nicely(CDir *dir, mds_rank_t dest);
  void maybe_do_queued_export();
  void clear_export_queue() {
    export_queue.clear();
  }
  
  void get_export_lock_set(CDir *dir, set<SimpleLock*>& locks);
  void get_export_client_set(CDir *dir, set<client_t> &client_set);
  void get_export_client_set(CInode *in, set<client_t> &client_set);

  void encode_export_inode(CInode *in, bufferlist& bl, 
			   map<client_t,entity_inst_t>& exported_client_map);
  void encode_export_inode_caps(CInode *in, bool auth_cap, bufferlist& bl,
				map<client_t,entity_inst_t>& exported_client_map);
  void finish_export_inode(CInode *in, utime_t now, mds_rank_t target,
			   map<client_t,Capability::Import>& peer_imported,
			   list<MDSInternalContextBase*>& finished);
  void finish_export_inode_caps(CInode *in, mds_rank_t target,
			        map<client_t,Capability::Import>& peer_imported);


  uint64_t encode_export_dir(bufferlist& exportbl,
			CDir *dir,
			map<client_t,entity_inst_t>& exported_client_map,
			utime_t now);
  void finish_export_dir(CDir *dir, utime_t now, mds_rank_t target,
			 map<inodeno_t,map<client_t,Capability::Import> >& peer_imported,
			 list<MDSInternalContextBase*>& finished, int *num_dentries);

  void clear_export_proxy_pins(CDir *dir);

  void export_caps(CInode *in);

  void decode_import_inode(CDentry *dn, bufferlist::iterator& blp,
			   mds_rank_t oldauth, LogSegment *ls,
			   map<CInode*, map<client_t,Capability::Export> >& cap_imports,
			   list<ScatterLock*>& updated_scatterlocks);
  void decode_import_inode_caps(CInode *in, bool auth_cap, bufferlist::iterator &blp,
				map<CInode*, map<client_t,Capability::Export> >& cap_imports);
  void finish_import_inode_caps(CInode *in, mds_rank_t from, bool auth_cap,
				map<client_t,Capability::Export> &export_map,
				map<client_t,Capability::Import> &import_map);
  int decode_import_dir(bufferlist::iterator& blp,
			mds_rank_t oldauth,
			CDir *import_root,
			EImportStart *le, 
			LogSegment *ls,
			map<CInode*, map<client_t,Capability::Export> >& cap_imports,
			list<ScatterLock*>& updated_scatterlocks, utime_t now);

  void import_reverse(CDir *dir);

  void import_finish(CDir *dir, bool notify, bool last=true);

private:
  MDSRank *mds;
  MDCache *cache;
};

#endif
Commit	Line	Data
7c673cae FG	1	// -- mode:C++; tab-width:8; c-basic-offset:2; indent-tabs-mode:t --
	2	// vim: ts=8 sw=2 smarttab
	3	/*
	4	* Ceph - scalable distributed file system
	5	*
	6	* Copyright (C) 2004-2006 Sage Weil <sage@newdream.net>
	7	*
	8	* This is free software; you can redistribute it and/or
	9	* modify it under the terms of the GNU Lesser General Public
	10	* License version 2.1, as published by the Free Software
	11	* Foundation. See file COPYING.
	12	*
	13	* Handles the import and export of mds authorities and actual cache data.
	14	* See src/doc/exports.txt for a description.
	15	*/
	16
	17	#ifndef CEPH_MDS_MIGRATOR_H
	18	#define CEPH_MDS_MIGRATOR_H
	19
	20	#include "include/types.h"
	21
	22	#include <map>
	23	#include <list>
	24	#include <set>
	25	using std::map;
	26	using std::list;
	27	using std::set;
	28
	29
	30	class MDSRank;
	31	class CDir;
	32	class CInode;
	33	class CDentry;
	34
	35	class MExportDirDiscover;
	36	class MExportDirDiscoverAck;
	37	class MExportDirCancel;
	38	class MExportDirPrep;
	39	class MExportDirPrepAck;
	40	class MExportDir;
	41	class MExportDirAck;
	42	class MExportDirNotify;
	43	class MExportDirNotifyAck;
	44	class MExportDirFinish;
	45
	46	class MExportCaps;
	47	class MExportCapsAck;
	48	class MGatherCaps;
	49
	50	class EImportStart;
	51
	52	class Migrator {
	53	public:
	54	// export stages. used to clean up intelligently if there's a failure.
	55	const static int EXPORT_CANCELLED = 0; // cancelled
	56	const static int EXPORT_CANCELLING = 1; // waiting for cancel notifyacks
	57	const static int EXPORT_LOCKING = 2; // acquiring locks
	58	const static int EXPORT_DISCOVERING = 3; // dest is disovering export dir
	59	const static int EXPORT_FREEZING = 4; // we're freezing the dir tree
	60	const static int EXPORT_PREPPING = 5; // sending dest spanning tree to export bounds
	61	const static int EXPORT_WARNING = 6; // warning bystanders of dir_auth_pending
	62	const static int EXPORT_EXPORTING = 7; // sent actual export, waiting for ack
	63	const static int EXPORT_LOGGINGFINISH = 8; // logging EExportFinish
	64	const static int EXPORT_NOTIFYING = 9; // waiting for notifyacks
65	static const char *get_export_statename(int s) {
66	switch (s) {
67	case EXPORT_CANCELLING: return "cancelling";
68	case EXPORT_LOCKING: return "locking";
69	case EXPORT_DISCOVERING: return "discovering";
70	case EXPORT_FREEZING: return "freezing";
71	case EXPORT_PREPPING: return "prepping";
72	case EXPORT_WARNING: return "warning";
73	case EXPORT_EXPORTING: return "exporting";
74	case EXPORT_LOGGINGFINISH: return "loggingfinish";
75	case EXPORT_NOTIFYING: return "notifying";
76	default: ceph_abort(); return 0;
77	}
78	}
79
80	// -- imports --
81	const static int IMPORT_DISCOVERING = 1; // waiting for prep
82	const static int IMPORT_DISCOVERED = 2; // waiting for prep
83	const static int IMPORT_PREPPING = 3; // opening dirs on bounds
84	const static int IMPORT_PREPPED = 4; // opened bounds, waiting for import
85	const static int IMPORT_LOGGINGSTART = 5; // got import, logging EImportStart
86	const static int IMPORT_ACKING = 6; // logged EImportStart, sent ack, waiting for finish
87	const static int IMPORT_FINISHING = 7; // sent cap imports, waiting for finish
88	const static int IMPORT_ABORTING = 8; // notifying bystanders of an abort before unfreezing
89	static const char *get_import_statename(int s) {
90	switch (s) {
91	case IMPORT_DISCOVERING: return "discovering";
92	case IMPORT_DISCOVERED: return "discovered";
93	case IMPORT_PREPPING: return "prepping";
94	case IMPORT_PREPPED: return "prepped";
95	case IMPORT_LOGGINGSTART: return "loggingstart";
96	case IMPORT_ACKING: return "acking";
97	case IMPORT_FINISHING: return "finishing";
98	case IMPORT_ABORTING: return "aborting";
99	default: ceph_abort(); return 0;
100	}
101	}
102
103	// -- cons --
104	Migrator(MDSRank m, MDCache c) : mds(m), cache(c) {}
105
106
107
108	protected:
109	// export fun
110	struct export_state_t {
111	int state;
112	mds_rank_t peer;
113	uint64_t tid;
114	set<mds_rank_t> warning_ack_waiting;
115	set<mds_rank_t> notify_ack_waiting;
116	map<inodeno_t,map<client_t,Capability::Import> > peer_imported;
117	MutationRef mut;
118	// for freeze tree deadlock detection
119	utime_t last_cum_auth_pins_change;
120	int last_cum_auth_pins;
121	int num_remote_waiters; // number of remote authpin waiters
122	export_state_t() : state(0), peer(0), tid(0), mut(),
123	last_cum_auth_pins(0), num_remote_waiters(0) {}
124	};
125
126	map<CDir*, export_state_t> export_state;
127
128	list<pair<dirfrag_t,mds_rank_t> > export_queue;
129
130	// import fun
131	struct import_state_t {
132	int state;
133	mds_rank_t peer;
134	uint64_t tid;
135	set<mds_rank_t> bystanders;
136	list<dirfrag_t> bound_ls;
137	list<ScatterLock*> updated_scatterlocks;
138	map<client_t,entity_inst_t> client_map;
139	map<CInode*, map<client_t,Capability::Export> > peer_exports;
140	MutationRef mut;
141	import_state_t() : state(0), peer(0), tid(0), mut() {}
142	};
143
144	map<dirfrag_t, import_state_t> import_state;
145
146	void handle_export_discover_ack(MExportDirDiscoverAck *m);
147	void export_frozen(CDir *dir, uint64_t tid);
148	void handle_export_prep_ack(MExportDirPrepAck *m);
149	void export_sessions_flushed(CDir *dir, uint64_t tid);
150	void export_go(CDir *dir);
151	void export_go_synced(CDir *dir, uint64_t tid);
152	void export_try_cancel(CDir *dir, bool notify_peer=true);
153	void export_cancel_finish(CDir *dir);
154	void export_reverse(CDir *dir);
155	void export_notify_abort(CDir dir, set<CDir>& bounds);
156	void handle_export_ack(MExportDirAck *m);
157	void export_logged_finish(CDir *dir);
158	void handle_export_notify_ack(MExportDirNotifyAck *m);
159	void export_finish(CDir *dir);
160
161	void handle_gather_caps(MGatherCaps *m);
162
163	friend class C_MDC_ExportFreeze;
164	friend class C_MDS_ExportFinishLogged;
165	friend class C_M_ExportGo;
166	friend class C_M_ExportSessionsFlushed;
167	friend class MigratorContext;
168	friend class MigratorLogContext;
169
170	// importer
171	void handle_export_discover(MExportDirDiscover *m);
172	void handle_export_cancel(MExportDirCancel *m);
173	void handle_export_prep(MExportDirPrep *m);
174	void handle_export_dir(MExportDir *m);
175
176	void import_reverse_discovering(dirfrag_t df);
177	void import_reverse_discovered(dirfrag_t df, CInode *diri);
178	void import_reverse_prepping(CDir *dir);
179	void import_remove_pins(CDir dir, set<CDir>& bounds);
180	void import_reverse_unfreeze(CDir *dir);
181	void import_reverse_final(CDir *dir);
182	void import_notify_abort(CDir dir, set<CDir>& bounds);
183	void import_notify_finish(CDir dir, set<CDir>& bounds);
184	void import_logged_start(dirfrag_t df, CDir *dir, mds_rank_t from,
185	map<client_t,entity_inst_t> &imported_client_map,
186	map<client_t,uint64_t>& sseqmap);
187	void handle_export_finish(MExportDirFinish *m);
188
189	void handle_export_caps(MExportCaps *m);
190	void logged_import_caps(CInode *in,
191	mds_rank_t from,
192	map<CInode*, map<client_t,Capability::Export> >& cap_imports,
193	map<client_t,entity_inst_t>& client_map,
194	map<client_t,uint64_t>& sseqmap);
195
196
197	friend class C_MDS_ImportDirLoggedStart;
198	friend class C_MDS_ImportDirLoggedFinish;
199	friend class C_M_LoggedImportCaps;
200
201	// bystander
202	void handle_export_notify(MExportDirNotify *m);
203
204
205	public:
206
207	void dispatch(Message*);
208
209	void show_importing();
210	void show_exporting();
211
212	int get_num_exporting() const { return export_state.size(); }
213	int get_export_queue_size() const { return export_queue.size(); }
214
215	// -- status --
216	int is_exporting(CDir *dir) const {
217	map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
218	if (it != export_state.end()) return it->second.state;
219	return 0;
220	}
221	bool is_exporting() const { return !export_state.empty(); }
222	int is_importing(dirfrag_t df) const {
223	map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
224	if (it != import_state.end()) return it->second.state;
225	return 0;
226	}
227	bool is_importing() const { return !import_state.empty(); }
228
229	bool is_ambiguous_import(dirfrag_t df) const {
230	map<dirfrag_t, import_state_t>::const_iterator p = import_state.find(df);
231	if (p == import_state.end())
232	return false;
233	if (p->second.state >= IMPORT_LOGGINGSTART &&
234	p->second.state < IMPORT_ABORTING)
235	return true;
236	return false;
237	}
238
239	int get_import_state(dirfrag_t df) const {
240	map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
241	assert(it != import_state.end());
242	return it->second.state;
243	}
244	int get_import_peer(dirfrag_t df) const {
245	map<dirfrag_t, import_state_t>::const_iterator it = import_state.find(df);
246	assert(it != import_state.end());
247	return it->second.peer;
248	}
249
250	int get_export_state(CDir *dir) const {
251	map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
252	assert(it != export_state.end());
253	return it->second.state;
254	}
255	// this returns true if we are export @dir,
256	// and are not waiting for @who to be
257	// be warned of ambiguous auth.
258	// only returns meaningful results during EXPORT_WARNING state.
259	bool export_has_warned(CDir *dir, mds_rank_t who) {
260	map<CDir*, export_state_t>::iterator it = export_state.find(dir);
261	assert(it != export_state.end());
262	assert(it->second.state == EXPORT_WARNING);
263	return (it->second.warning_ack_waiting.count(who) == 0);
264	}
265
266	bool export_has_notified(CDir *dir, mds_rank_t who) const {
267	map<CDir*, export_state_t>::const_iterator it = export_state.find(dir);
268	assert(it != export_state.end());
269	assert(it->second.state == EXPORT_NOTIFYING);
270	return (it->second.notify_ack_waiting.count(who) == 0);
271	}
272
273	void export_freeze_inc_num_waiters(CDir *dir) {
274	map<CDir*, export_state_t>::iterator it = export_state.find(dir);
275	assert(it != export_state.end());
276	it->second.num_remote_waiters++;
277	}
278	void find_stale_export_freeze();
279
280	// -- misc --
281	void handle_mds_failure_or_stop(mds_rank_t who);
282
283	void audit();
284
285	// -- import/export --
286	// exporter
287	void dispatch_export_dir(MDRequestRef& mdr, int count);
288	void export_dir(CDir *dir, mds_rank_t dest);
289	void export_empty_import(CDir *dir);
290
291	void export_dir_nicely(CDir *dir, mds_rank_t dest);
292	void maybe_do_queued_export();
293	void clear_export_queue() {
294	export_queue.clear();
295	}
296
297	void get_export_lock_set(CDir dir, set<SimpleLock>& locks);
298	void get_export_client_set(CDir *dir, set<client_t> &client_set);
299	void get_export_client_set(CInode *in, set<client_t> &client_set);
300
301	void encode_export_inode(CInode *in, bufferlist& bl,
302	map<client_t,entity_inst_t>& exported_client_map);
303	void encode_export_inode_caps(CInode *in, bool auth_cap, bufferlist& bl,
304	map<client_t,entity_inst_t>& exported_client_map);
305	void finish_export_inode(CInode *in, utime_t now, mds_rank_t target,
306	map<client_t,Capability::Import>& peer_imported,
307	list<MDSInternalContextBase*>& finished);
308	void finish_export_inode_caps(CInode *in, mds_rank_t target,
309	map<client_t,Capability::Import>& peer_imported);
310
311
312	uint64_t encode_export_dir(bufferlist& exportbl,
313	CDir *dir,
314	map<client_t,entity_inst_t>& exported_client_map,
315	utime_t now);
316	void finish_export_dir(CDir *dir, utime_t now, mds_rank_t target,
317	map<inodeno_t,map<client_t,Capability::Import> >& peer_imported,
318	list<MDSInternalContextBase>& finished, int num_dentries);
319
320	void clear_export_proxy_pins(CDir *dir);
321
322	void export_caps(CInode *in);
323
324	void decode_import_inode(CDentry *dn, bufferlist::iterator& blp,
325	mds_rank_t oldauth, LogSegment *ls,
326	map<CInode*, map<client_t,Capability::Export> >& cap_imports,
327	list<ScatterLock*>& updated_scatterlocks);
328	void decode_import_inode_caps(CInode *in, bool auth_cap, bufferlist::iterator &blp,
329	map<CInode*, map<client_t,Capability::Export> >& cap_imports);
330	void finish_import_inode_caps(CInode *in, mds_rank_t from, bool auth_cap,
331	map<client_t,Capability::Export> &export_map,
332	map<client_t,Capability::Import> &import_map);
333	int decode_import_dir(bufferlist::iterator& blp,
334	mds_rank_t oldauth,
335	CDir *import_root,
336	EImportStart *le,
337	LogSegment *ls,
338	map<CInode*, map<client_t,Capability::Export> >& cap_imports,
339	list<ScatterLock*>& updated_scatterlocks, utime_t now);
340
341	void import_reverse(CDir *dir);
342
343	void import_finish(CDir *dir, bool notify, bool last=true);
344
345	private:
346	MDSRank *mds;
347	MDCache *cache;
348	};
349
350	#endif