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1/*
2 * GPL HEADER START
3 *
4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
5 *
6 * This program is free software; you can redistribute it and/or modify
7 * it under the terms of the GNU General Public License version 2 only,
8 * as published by the Free Software Foundation.
9 *
10 * This program is distributed in the hope that it will be useful, but
11 * WITHOUT ANY WARRANTY; without even the implied warranty of
12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
13 * General Public License version 2 for more details (a copy is included
14 * in the LICENSE file that accompanied this code).
15 *
16 * You should have received a copy of the GNU General Public License
17 * version 2 along with this program; If not, see
18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
19 *
20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
21 * CA 95054 USA or visit www.sun.com if you need additional information or
22 * have any questions.
23 *
24 * GPL HEADER END
25 */
26/*
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
29 *
30 * Copyright (c) 2010, 2012, Intel Corporation.
31 */
32/*
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
35 */
36
37/** \defgroup LDLM Lustre Distributed Lock Manager
38 *
39 * Lustre DLM is based on VAX DLM.
40 * Its two main roles are:
41 *   - To provide locking assuring consistency of data on all Lustre nodes.
42 *   - To allow clients to cache state protected by a lock by holding the
43 *     lock until a conflicting lock is requested or it is expired by the LRU.
44 *
45 * @{
46 */
47
48#ifndef _LUSTRE_DLM_H__
49#define _LUSTRE_DLM_H__
50
51#include "lustre_lib.h"
52#include "lustre_net.h"
53#include "lustre_import.h"
54#include "lustre_handles.h"
55#include "interval_tree.h"	/* for interval_node{}, ldlm_extent */
56#include "lu_ref.h"
57
58#include "lustre_dlm_flags.h"
59
60struct obd_ops;
61struct obd_device;
62
63#define OBD_LDLM_DEVICENAME  "ldlm"
64
65#define LDLM_DEFAULT_LRU_SIZE (100 * num_online_cpus())
66#define LDLM_DEFAULT_MAX_ALIVE (cfs_time_seconds(36000))
67#define LDLM_CTIME_AGE_LIMIT (10)
68#define LDLM_DEFAULT_PARALLEL_AST_LIMIT 1024
69
70/**
71 * LDLM non-error return states
72 */
73typedef enum {
74	ELDLM_OK = 0,
75
76	ELDLM_LOCK_CHANGED = 300,
77	ELDLM_LOCK_ABORTED = 301,
78	ELDLM_LOCK_REPLACED = 302,
79	ELDLM_NO_LOCK_DATA = 303,
80	ELDLM_LOCK_WOULDBLOCK = 304,
81
82	ELDLM_NAMESPACE_EXISTS = 400,
83	ELDLM_BAD_NAMESPACE    = 401
84} ldlm_error_t;
85
86/**
87 * LDLM namespace type.
88 * The "client" type is actually an indication that this is a narrow local view
89 * into complete namespace on the server. Such namespaces cannot make any
90 * decisions about lack of conflicts or do any autonomous lock granting without
91 * first speaking to a server.
92 */
93typedef enum {
94	LDLM_NAMESPACE_SERVER = 1 << 0,
95	LDLM_NAMESPACE_CLIENT = 1 << 1
96} ldlm_side_t;
97
98/**
99 * The blocking callback is overloaded to perform two functions.  These flags
100 * indicate which operation should be performed.
101 */
102#define LDLM_CB_BLOCKING    1
103#define LDLM_CB_CANCELING   2
104
105/**
106 * \name Lock Compatibility Matrix.
107 *
108 * A lock has both a type (extent, flock, inode bits, or plain) and a mode.
109 * Lock types are described in their respective implementation files:
110 * ldlm_{extent,flock,inodebits,plain}.c.
111 *
112 * There are six lock modes along with a compatibility matrix to indicate if
113 * two locks are compatible.
114 *
115 * - EX: Exclusive mode. Before a new file is created, MDS requests EX lock
116 *   on the parent.
117 * - PW: Protective Write (normal write) mode. When a client requests a write
118 *   lock from an OST, a lock with PW mode will be issued.
119 * - PR: Protective Read (normal read) mode. When a client requests a read from
120 *   an OST, a lock with PR mode will be issued. Also, if the client opens a
121 *   file for execution, it is granted a lock with PR mode.
122 * - CW: Concurrent Write mode. The type of lock that the MDS grants if a client
123 *   requests a write lock during a file open operation.
124 * - CR Concurrent Read mode. When a client performs a path lookup, MDS grants
125 *   an inodebit lock with the CR mode on the intermediate path component.
126 * - NL Null mode.
127 *
128 * <PRE>
129 *       NL  CR  CW  PR  PW  EX
130 *  NL    1   1   1   1   1   1
131 *  CR    1   1   1   1   1   0
132 *  CW    1   1   1   0   0   0
133 *  PR    1   1   0   1   0   0
134 *  PW    1   1   0   0   0   0
135 *  EX    1   0   0   0   0   0
136 * </PRE>
137 */
138/** @{ */
139#define LCK_COMPAT_EX  LCK_NL
140#define LCK_COMPAT_PW  (LCK_COMPAT_EX | LCK_CR)
141#define LCK_COMPAT_PR  (LCK_COMPAT_PW | LCK_PR)
142#define LCK_COMPAT_CW  (LCK_COMPAT_PW | LCK_CW)
143#define LCK_COMPAT_CR  (LCK_COMPAT_CW | LCK_PR | LCK_PW)
144#define LCK_COMPAT_NL  (LCK_COMPAT_CR | LCK_EX | LCK_GROUP)
145#define LCK_COMPAT_GROUP  (LCK_GROUP | LCK_NL)
146#define LCK_COMPAT_COS (LCK_COS)
147/** @} Lock Compatibility Matrix */
148
149extern ldlm_mode_t lck_compat_array[];
150
151static inline void lockmode_verify(ldlm_mode_t mode)
152{
153       LASSERT(mode > LCK_MINMODE && mode < LCK_MAXMODE);
154}
155
156static inline int lockmode_compat(ldlm_mode_t exist_mode, ldlm_mode_t new_mode)
157{
158       return (lck_compat_array[exist_mode] & new_mode);
159}
160
161/*
162 *
163 * cluster name spaces
164 *
165 */
166
167#define DLM_OST_NAMESPACE 1
168#define DLM_MDS_NAMESPACE 2
169
170/* XXX
171   - do we just separate this by security domains and use a prefix for
172     multiple namespaces in the same domain?
173   -
174*/
175
176/**
177 * Locking rules for LDLM:
178 *
179 * lr_lock
180 *
181 * lr_lock
182 *     waiting_locks_spinlock
183 *
184 * lr_lock
185 *     led_lock
186 *
187 * lr_lock
188 *     ns_lock
189 *
190 * lr_lvb_mutex
191 *     lr_lock
192 *
193 */
194
195struct ldlm_pool;
196struct ldlm_lock;
197struct ldlm_resource;
198struct ldlm_namespace;
199
200/**
201 * Operations on LDLM pools.
202 * LDLM pool is a pool of locks in the namespace without any implicitly
203 * specified limits.
204 * Locks in the pool are organized in LRU.
205 * Local memory pressure or server instructions (e.g. mempressure on server)
206 * can trigger freeing of locks from the pool
207 */
208struct ldlm_pool_ops {
209	/** Recalculate pool \a pl usage */
210	int (*po_recalc)(struct ldlm_pool *pl);
211	/** Cancel at least \a nr locks from pool \a pl */
212	int (*po_shrink)(struct ldlm_pool *pl, int nr,
213			 gfp_t gfp_mask);
214	int (*po_setup)(struct ldlm_pool *pl, int limit);
215};
216
217/** One second for pools thread check interval. Each pool has own period. */
218#define LDLM_POOLS_THREAD_PERIOD (1)
219
220/** ~6% margin for modest pools. See ldlm_pool.c for details. */
221#define LDLM_POOLS_MODEST_MARGIN_SHIFT (4)
222
223/** Default recalc period for server side pools in sec. */
224#define LDLM_POOL_SRV_DEF_RECALC_PERIOD (1)
225
226/** Default recalc period for client side pools in sec. */
227#define LDLM_POOL_CLI_DEF_RECALC_PERIOD (10)
228
229/**
230 * LDLM pool structure to track granted locks.
231 * For purposes of determining when to release locks on e.g. memory pressure.
232 * This feature is commonly referred to as lru_resize.
233 */
234struct ldlm_pool {
235	/** Pool proc directory. */
236	struct proc_dir_entry	*pl_proc_dir;
237	/** Pool name, must be long enough to hold compound proc entry name. */
238	char			pl_name[100];
239	/** Lock for protecting SLV/CLV updates. */
240	spinlock_t		pl_lock;
241	/** Number of allowed locks in in pool, both, client and server side. */
242	atomic_t		pl_limit;
243	/** Number of granted locks in */
244	atomic_t		pl_granted;
245	/** Grant rate per T. */
246	atomic_t		pl_grant_rate;
247	/** Cancel rate per T. */
248	atomic_t		pl_cancel_rate;
249	/** Server lock volume (SLV). Protected by pl_lock. */
250	__u64			pl_server_lock_volume;
251	/** Current biggest client lock volume. Protected by pl_lock. */
252	__u64			pl_client_lock_volume;
253	/** Lock volume factor. SLV on client is calculated as following:
254	 *  server_slv * lock_volume_factor. */
255	atomic_t		pl_lock_volume_factor;
256	/** Time when last SLV from server was obtained. */
257	time_t			pl_recalc_time;
258	/** Recalculation period for pool. */
259	time_t			pl_recalc_period;
260	/** Recalculation and shrink operations. */
261	const struct ldlm_pool_ops	*pl_ops;
262	/** Number of planned locks for next period. */
263	int			pl_grant_plan;
264	/** Pool statistics. */
265	struct lprocfs_stats	*pl_stats;
266};
267
268typedef int (*ldlm_res_policy)(struct ldlm_namespace *, struct ldlm_lock **,
269			       void *req_cookie, ldlm_mode_t mode, __u64 flags,
270			       void *data);
271
272typedef int (*ldlm_cancel_for_recovery)(struct ldlm_lock *lock);
273
274/**
275 * LVB operations.
276 * LVB is Lock Value Block. This is a special opaque (to LDLM) value that could
277 * be associated with an LDLM lock and transferred from client to server and
278 * back.
279 *
280 * Currently LVBs are used by:
281 *  - OSC-OST code to maintain current object size/times
282 *  - layout lock code to return the layout when the layout lock is granted
283 */
284struct ldlm_valblock_ops {
285	int (*lvbo_init)(struct ldlm_resource *res);
286	int (*lvbo_update)(struct ldlm_resource *res,
287			   struct ptlrpc_request *r,
288			   int increase);
289	int (*lvbo_free)(struct ldlm_resource *res);
290	/* Return size of lvb data appropriate RPC size can be reserved */
291	int (*lvbo_size)(struct ldlm_lock *lock);
292	/* Called to fill in lvb data to RPC buffer @buf */
293	int (*lvbo_fill)(struct ldlm_lock *lock, void *buf, int buflen);
294};
295
296/**
297 * LDLM pools related, type of lock pool in the namespace.
298 * Greedy means release cached locks aggressively
299 */
300typedef enum {
301	LDLM_NAMESPACE_GREEDY = 1 << 0,
302	LDLM_NAMESPACE_MODEST = 1 << 1
303} ldlm_appetite_t;
304
305/**
306 * Default values for the "max_nolock_size", "contention_time" and
307 * "contended_locks" namespace tunables.
308 */
309#define NS_DEFAULT_MAX_NOLOCK_BYTES 0
310#define NS_DEFAULT_CONTENTION_SECONDS 2
311#define NS_DEFAULT_CONTENDED_LOCKS 32
312
313struct ldlm_ns_bucket {
314	/** back pointer to namespace */
315	struct ldlm_namespace      *nsb_namespace;
316	/**
317	 * Estimated lock callback time.  Used by adaptive timeout code to
318	 * avoid spurious client evictions due to unresponsiveness when in
319	 * fact the network or overall system load is at fault
320	 */
321	struct adaptive_timeout     nsb_at_estimate;
322};
323
324enum {
325	/** LDLM namespace lock stats */
326	LDLM_NSS_LOCKS	  = 0,
327	LDLM_NSS_LAST
328};
329
330typedef enum {
331	/** invalid type */
332	LDLM_NS_TYPE_UNKNOWN    = 0,
333	/** mdc namespace */
334	LDLM_NS_TYPE_MDC,
335	/** mds namespace */
336	LDLM_NS_TYPE_MDT,
337	/** osc namespace */
338	LDLM_NS_TYPE_OSC,
339	/** ost namespace */
340	LDLM_NS_TYPE_OST,
341	/** mgc namespace */
342	LDLM_NS_TYPE_MGC,
343	/** mgs namespace */
344	LDLM_NS_TYPE_MGT,
345} ldlm_ns_type_t;
346
347/**
348 * LDLM Namespace.
349 *
350 * Namespace serves to contain locks related to a particular service.
351 * There are two kinds of namespaces:
352 * - Server namespace has knowledge of all locks and is therefore authoritative
353 *   to make decisions like what locks could be granted and what conflicts
354 *   exist during new lock enqueue.
355 * - Client namespace only has limited knowledge about locks in the namespace,
356 *   only seeing locks held by the client.
357 *
358 * Every Lustre service has one server namespace present on the server serving
359 * that service. Every client connected to the service has a client namespace
360 * for it.
361 * Every lock obtained by client in that namespace is actually represented by
362 * two in-memory locks. One on the server and one on the client. The locks are
363 * linked by a special cookie by which one node can tell to the other which lock
364 * it actually means during communications. Such locks are called remote locks.
365 * The locks held by server only without any reference to a client are called
366 * local locks.
367 */
368struct ldlm_namespace {
369	/** Backward link to OBD, required for LDLM pool to store new SLV. */
370	struct obd_device	*ns_obd;
371
372	/** Flag indicating if namespace is on client instead of server */
373	ldlm_side_t		ns_client;
374
375	/** Resource hash table for namespace. */
376	struct cfs_hash		*ns_rs_hash;
377
378	/** serialize */
379	spinlock_t		ns_lock;
380
381	/** big refcount (by bucket) */
382	atomic_t		ns_bref;
383
384	/**
385	 * Namespace connect flags supported by server (may be changed via
386	 * /proc, LRU resize may be disabled/enabled).
387	 */
388	__u64			ns_connect_flags;
389
390	/** Client side original connect flags supported by server. */
391	__u64			ns_orig_connect_flags;
392
393	/* namespace proc dir entry */
394	struct proc_dir_entry	*ns_proc_dir_entry;
395
396	/**
397	 * Position in global namespace list linking all namespaces on
398	 * the node.
399	 */
400	struct list_head		ns_list_chain;
401
402	/**
403	 * List of unused locks for this namespace. This list is also called
404	 * LRU lock list.
405	 * Unused locks are locks with zero reader/writer reference counts.
406	 * This list is only used on clients for lock caching purposes.
407	 * When we want to release some locks voluntarily or if server wants
408	 * us to release some locks due to e.g. memory pressure, we take locks
409	 * to release from the head of this list.
410	 * Locks are linked via l_lru field in \see struct ldlm_lock.
411	 */
412	struct list_head		ns_unused_list;
413	/** Number of locks in the LRU list above */
414	int			ns_nr_unused;
415
416	/**
417	 * Maximum number of locks permitted in the LRU. If 0, means locks
418	 * are managed by pools and there is no preset limit, rather it is all
419	 * controlled by available memory on this client and on server.
420	 */
421	unsigned int		ns_max_unused;
422	/** Maximum allowed age (last used time) for locks in the LRU */
423	unsigned int		ns_max_age;
424	/**
425	 * Server only: number of times we evicted clients due to lack of reply
426	 * to ASTs.
427	 */
428	unsigned int		ns_timeouts;
429	/**
430	 * Number of seconds since the file change time after which the
431	 * MDT will return an UPDATE lock along with a LOOKUP lock.
432	 * This allows the client to start caching negative dentries
433	 * for a directory and may save an RPC for a later stat.
434	 */
435	unsigned int		ns_ctime_age_limit;
436
437	/**
438	 * Used to rate-limit ldlm_namespace_dump calls.
439	 * \see ldlm_namespace_dump. Increased by 10 seconds every time
440	 * it is called.
441	 */
442	unsigned long		ns_next_dump;
443
444	/** "policy" function that does actual lock conflict determination */
445	ldlm_res_policy		ns_policy;
446
447	/**
448	 * LVB operations for this namespace.
449	 * \see struct ldlm_valblock_ops
450	 */
451	struct ldlm_valblock_ops *ns_lvbo;
452
453	/**
454	 * Used by filter code to store pointer to OBD of the service.
455	 * Should be dropped in favor of \a ns_obd
456	 */
457	void			*ns_lvbp;
458
459	/**
460	 * Wait queue used by __ldlm_namespace_free. Gets woken up every time
461	 * a resource is removed.
462	 */
463	wait_queue_head_t		ns_waitq;
464	/** LDLM pool structure for this namespace */
465	struct ldlm_pool	ns_pool;
466	/** Definition of how eagerly unused locks will be released from LRU */
467	ldlm_appetite_t		ns_appetite;
468
469	/**
470	 * If more than \a ns_contended_locks are found, the resource is
471	 * considered to be contended. Lock enqueues might specify that no
472	 * contended locks should be granted
473	 */
474	unsigned		ns_contended_locks;
475
476	/**
477	 * The resources in this namespace remember contended state during
478	 * \a ns_contention_time, in seconds.
479	 */
480	unsigned		ns_contention_time;
481
482	/**
483	 * Limit size of contended extent locks, in bytes.
484	 * If extended lock is requested for more then this many bytes and
485	 * caller instructs us not to grant contended locks, we would disregard
486	 * such a request.
487	 */
488	unsigned		ns_max_nolock_size;
489
490	/** Limit of parallel AST RPC count. */
491	unsigned		ns_max_parallel_ast;
492
493	/** Callback to cancel locks before replaying it during recovery. */
494	ldlm_cancel_for_recovery ns_cancel_for_recovery;
495
496	/** LDLM lock stats */
497	struct lprocfs_stats	*ns_stats;
498
499	/**
500	 * Flag to indicate namespace is being freed. Used to determine if
501	 * recalculation of LDLM pool statistics should be skipped.
502	 */
503	unsigned		ns_stopping:1;
504};
505
506/**
507 * Returns 1 if namespace \a ns is a client namespace.
508 */
509static inline int ns_is_client(struct ldlm_namespace *ns)
510{
511	LASSERT(ns != NULL);
512	LASSERT(!(ns->ns_client & ~(LDLM_NAMESPACE_CLIENT |
513				    LDLM_NAMESPACE_SERVER)));
514	LASSERT(ns->ns_client == LDLM_NAMESPACE_CLIENT ||
515		ns->ns_client == LDLM_NAMESPACE_SERVER);
516	return ns->ns_client == LDLM_NAMESPACE_CLIENT;
517}
518
519/**
520 * Returns 1 if namespace \a ns is a server namespace.
521 */
522static inline int ns_is_server(struct ldlm_namespace *ns)
523{
524	LASSERT(ns != NULL);
525	LASSERT(!(ns->ns_client & ~(LDLM_NAMESPACE_CLIENT |
526				    LDLM_NAMESPACE_SERVER)));
527	LASSERT(ns->ns_client == LDLM_NAMESPACE_CLIENT ||
528		ns->ns_client == LDLM_NAMESPACE_SERVER);
529	return ns->ns_client == LDLM_NAMESPACE_SERVER;
530}
531
532/**
533 * Returns 1 if namespace \a ns supports early lock cancel (ELC).
534 */
535static inline int ns_connect_cancelset(struct ldlm_namespace *ns)
536{
537	LASSERT(ns != NULL);
538	return !!(ns->ns_connect_flags & OBD_CONNECT_CANCELSET);
539}
540
541/**
542 * Returns 1 if this namespace supports lru_resize.
543 */
544static inline int ns_connect_lru_resize(struct ldlm_namespace *ns)
545{
546	LASSERT(ns != NULL);
547	return !!(ns->ns_connect_flags & OBD_CONNECT_LRU_RESIZE);
548}
549
550static inline void ns_register_cancel(struct ldlm_namespace *ns,
551				      ldlm_cancel_for_recovery arg)
552{
553	LASSERT(ns != NULL);
554	ns->ns_cancel_for_recovery = arg;
555}
556
557struct ldlm_lock;
558
559/** Type for blocking callback function of a lock. */
560typedef int (*ldlm_blocking_callback)(struct ldlm_lock *lock,
561				      struct ldlm_lock_desc *new, void *data,
562				      int flag);
563/** Type for completion callback function of a lock. */
564typedef int (*ldlm_completion_callback)(struct ldlm_lock *lock, __u64 flags,
565					void *data);
566/** Type for glimpse callback function of a lock. */
567typedef int (*ldlm_glimpse_callback)(struct ldlm_lock *lock, void *data);
568
569/** Work list for sending GL ASTs to multiple locks. */
570struct ldlm_glimpse_work {
571	struct ldlm_lock	*gl_lock; /* lock to glimpse */
572	struct list_head		 gl_list; /* linkage to other gl work structs */
573	__u32			 gl_flags;/* see LDLM_GL_WORK_* below */
574	union ldlm_gl_desc	*gl_desc; /* glimpse descriptor to be packed in
575					   * glimpse callback request */
576};
577
578/** The ldlm_glimpse_work is allocated on the stack and should not be freed. */
579#define LDLM_GL_WORK_NOFREE 0x1
580
581/** Interval node data for each LDLM_EXTENT lock. */
582struct ldlm_interval {
583	struct interval_node	li_node;  /* node for tree management */
584	struct list_head		li_group; /* the locks which have the same
585					   * policy - group of the policy */
586};
587#define to_ldlm_interval(n) container_of(n, struct ldlm_interval, li_node)
588
589/**
590 * Interval tree for extent locks.
591 * The interval tree must be accessed under the resource lock.
592 * Interval trees are used for granted extent locks to speed up conflicts
593 * lookup. See ldlm/interval_tree.c for more details.
594 */
595struct ldlm_interval_tree {
596	/** Tree size. */
597	int			lit_size;
598	ldlm_mode_t		lit_mode;  /* lock mode */
599	struct interval_node	*lit_root; /* actual ldlm_interval */
600};
601
602/** Whether to track references to exports by LDLM locks. */
603#define LUSTRE_TRACKS_LOCK_EXP_REFS (0)
604
605/** Cancel flags. */
606typedef enum {
607	LCF_ASYNC      = 0x1, /* Cancel locks asynchronously. */
608	LCF_LOCAL      = 0x2, /* Cancel locks locally, not notifing server */
609	LCF_BL_AST     = 0x4, /* Cancel locks marked as LDLM_FL_BL_AST
610			       * in the same RPC */
611} ldlm_cancel_flags_t;
612
613struct ldlm_flock {
614	__u64 start;
615	__u64 end;
616	__u64 owner;
617	__u64 blocking_owner;
618	struct obd_export *blocking_export;
619	/* Protected by the hash lock */
620	__u32 blocking_refs;
621	__u32 pid;
622};
623
624typedef union {
625	struct ldlm_extent l_extent;
626	struct ldlm_flock l_flock;
627	struct ldlm_inodebits l_inodebits;
628} ldlm_policy_data_t;
629
630void ldlm_convert_policy_to_wire(ldlm_type_t type,
631				 const ldlm_policy_data_t *lpolicy,
632				 ldlm_wire_policy_data_t *wpolicy);
633void ldlm_convert_policy_to_local(struct obd_export *exp, ldlm_type_t type,
634				  const ldlm_wire_policy_data_t *wpolicy,
635				  ldlm_policy_data_t *lpolicy);
636
637enum lvb_type {
638	LVB_T_NONE	= 0,
639	LVB_T_OST	= 1,
640	LVB_T_LQUOTA	= 2,
641	LVB_T_LAYOUT	= 3,
642};
643
644/**
645 * LDLM lock structure
646 *
647 * Represents a single LDLM lock and its state in memory. Each lock is
648 * associated with a single ldlm_resource, the object which is being
649 * locked. There may be multiple ldlm_locks on a single resource,
650 * depending on the lock type and whether the locks are conflicting or
651 * not.
652 */
653struct ldlm_lock {
654	/**
655	 * Local lock handle.
656	 * When remote side wants to tell us about a lock, they address
657	 * it by this opaque handle.  The handle does not hold a
658	 * reference on the ldlm_lock, so it can be safely passed to
659	 * other threads or nodes. When the lock needs to be accessed
660	 * from the handle, it is looked up again in the lock table, and
661	 * may no longer exist.
662	 *
663	 * Must be first in the structure.
664	 */
665	struct portals_handle	l_handle;
666	/**
667	 * Lock reference count.
668	 * This is how many users have pointers to actual structure, so that
669	 * we do not accidentally free lock structure that is in use.
670	 */
671	atomic_t		l_refc;
672	/**
673	 * Internal spinlock protects l_resource.  We should hold this lock
674	 * first before taking res_lock.
675	 */
676	spinlock_t		l_lock;
677	/**
678	 * Pointer to actual resource this lock is in.
679	 * ldlm_lock_change_resource() can change this.
680	 */
681	struct ldlm_resource	*l_resource;
682	/**
683	 * List item for client side LRU list.
684	 * Protected by ns_lock in struct ldlm_namespace.
685	 */
686	struct list_head		l_lru;
687	/**
688	 * Linkage to resource's lock queues according to current lock state.
689	 * (could be granted, waiting or converting)
690	 * Protected by lr_lock in struct ldlm_resource.
691	 */
692	struct list_head		l_res_link;
693	/**
694	 * Tree node for ldlm_extent.
695	 */
696	struct ldlm_interval	*l_tree_node;
697	/**
698	 * Per export hash of locks.
699	 * Protected by per-bucket exp->exp_lock_hash locks.
700	 */
701	struct hlist_node	l_exp_hash;
702	/**
703	 * Per export hash of flock locks.
704	 * Protected by per-bucket exp->exp_flock_hash locks.
705	 */
706	struct hlist_node	l_exp_flock_hash;
707	/**
708	 * Requested mode.
709	 * Protected by lr_lock.
710	 */
711	ldlm_mode_t		l_req_mode;
712	/**
713	 * Granted mode, also protected by lr_lock.
714	 */
715	ldlm_mode_t		l_granted_mode;
716	/** Lock completion handler pointer. Called when lock is granted. */
717	ldlm_completion_callback l_completion_ast;
718	/**
719	 * Lock blocking AST handler pointer.
720	 * It plays two roles:
721	 * - as a notification of an attempt to queue a conflicting lock (once)
722	 * - as a notification when the lock is being cancelled.
723	 *
724	 * As such it's typically called twice: once for the initial conflict
725	 * and then once more when the last user went away and the lock is
726	 * cancelled (could happen recursively).
727	 */
728	ldlm_blocking_callback	l_blocking_ast;
729	/**
730	 * Lock glimpse handler.
731	 * Glimpse handler is used to obtain LVB updates from a client by
732	 * server
733	 */
734	ldlm_glimpse_callback	l_glimpse_ast;
735
736	/**
737	 * Lock export.
738	 * This is a pointer to actual client export for locks that were granted
739	 * to clients. Used server-side.
740	 */
741	struct obd_export	*l_export;
742	/**
743	 * Lock connection export.
744	 * Pointer to server export on a client.
745	 */
746	struct obd_export	*l_conn_export;
747
748	/**
749	 * Remote lock handle.
750	 * If the lock is remote, this is the handle of the other side lock
751	 * (l_handle)
752	 */
753	struct lustre_handle	l_remote_handle;
754
755	/**
756	 * Representation of private data specific for a lock type.
757	 * Examples are: extent range for extent lock or bitmask for ibits locks
758	 */
759	ldlm_policy_data_t	l_policy_data;
760
761	/**
762	 * Lock state flags. Protected by lr_lock.
763	 * \see lustre_dlm_flags.h where the bits are defined.
764	 */
765	__u64			l_flags;
766
767	/**
768	 * Lock r/w usage counters.
769	 * Protected by lr_lock.
770	 */
771	__u32			l_readers;
772	__u32			l_writers;
773	/**
774	 * If the lock is granted, a process sleeps on this waitq to learn when
775	 * it's no longer in use.  If the lock is not granted, a process sleeps
776	 * on this waitq to learn when it becomes granted.
777	 */
778	wait_queue_head_t		l_waitq;
779
780	/**
781	 * Seconds. It will be updated if there is any activity related to
782	 * the lock, e.g. enqueue the lock or send blocking AST.
783	 */
784	unsigned long		l_last_activity;
785
786	/**
787	 * Time last used by e.g. being matched by lock match.
788	 * Jiffies. Should be converted to time if needed.
789	 */
790	unsigned long		l_last_used;
791
792	/** Originally requested extent for the extent lock. */
793	struct ldlm_extent	l_req_extent;
794
795	/*
796	 * Client-side-only members.
797	 */
798
799	enum lvb_type	      l_lvb_type;
800
801	/**
802	 * Temporary storage for a LVB received during an enqueue operation.
803	 */
804	__u32			l_lvb_len;
805	void			*l_lvb_data;
806
807	/** Private storage for lock user. Opaque to LDLM. */
808	void			*l_ast_data;
809
810	/*
811	 * Server-side-only members.
812	 */
813
814	/**
815	 * Connection cookie for the client originating the operation.
816	 * Used by Commit on Share (COS) code. Currently only used for
817	 * inodebits locks on MDS.
818	 */
819	__u64			l_client_cookie;
820
821	/**
822	 * List item for locks waiting for cancellation from clients.
823	 * The lists this could be linked into are:
824	 * waiting_locks_list (protected by waiting_locks_spinlock),
825	 * then if the lock timed out, it is moved to
826	 * expired_lock_thread.elt_expired_locks for further processing.
827	 * Protected by elt_lock.
828	 */
829	struct list_head		l_pending_chain;
830
831	/**
832	 * Set when lock is sent a blocking AST. Time in seconds when timeout
833	 * is reached and client holding this lock could be evicted.
834	 * This timeout could be further extended by e.g. certain IO activity
835	 * under this lock.
836	 * \see ost_rw_prolong_locks
837	 */
838	unsigned long		l_callback_timeout;
839
840	/** Local PID of process which created this lock. */
841	__u32			l_pid;
842
843	/**
844	 * Number of times blocking AST was sent for this lock.
845	 * This is for debugging. Valid values are 0 and 1, if there is an
846	 * attempt to send blocking AST more than once, an assertion would be
847	 * hit. \see ldlm_work_bl_ast_lock
848	 */
849	int			l_bl_ast_run;
850	/** List item ldlm_add_ast_work_item() for case of blocking ASTs. */
851	struct list_head		l_bl_ast;
852	/** List item ldlm_add_ast_work_item() for case of completion ASTs. */
853	struct list_head		l_cp_ast;
854	/** For ldlm_add_ast_work_item() for "revoke" AST used in COS. */
855	struct list_head		l_rk_ast;
856
857	/**
858	 * Pointer to a conflicting lock that caused blocking AST to be sent
859	 * for this lock
860	 */
861	struct ldlm_lock	*l_blocking_lock;
862
863	/**
864	 * Protected by lr_lock, linkages to "skip lists".
865	 * For more explanations of skip lists see ldlm/ldlm_inodebits.c
866	 */
867	struct list_head		l_sl_mode;
868	struct list_head		l_sl_policy;
869
870	/** Reference tracking structure to debug leaked locks. */
871	struct lu_ref		l_reference;
872#if LUSTRE_TRACKS_LOCK_EXP_REFS
873	/* Debugging stuff for bug 20498, for tracking export references. */
874	/** number of export references taken */
875	int			l_exp_refs_nr;
876	/** link all locks referencing one export */
877	struct list_head		l_exp_refs_link;
878	/** referenced export object */
879	struct obd_export	*l_exp_refs_target;
880#endif
881	/**
882	 * export blocking dlm lock list, protected by
883	 * l_export->exp_bl_list_lock.
884	 * Lock order of waiting_lists_spinlock, exp_bl_list_lock and res lock
885	 * is: res lock -> exp_bl_list_lock -> wanting_lists_spinlock.
886	 */
887	struct list_head		l_exp_list;
888};
889
890/**
891 * LDLM resource description.
892 * Basically, resource is a representation for a single object.
893 * Object has a name which is currently 4 64-bit integers. LDLM user is
894 * responsible for creation of a mapping between objects it wants to be
895 * protected and resource names.
896 *
897 * A resource can only hold locks of a single lock type, though there may be
898 * multiple ldlm_locks on a single resource, depending on the lock type and
899 * whether the locks are conflicting or not.
900 */
901struct ldlm_resource {
902	struct ldlm_ns_bucket	*lr_ns_bucket;
903
904	/**
905	 * List item for list in namespace hash.
906	 * protected by ns_lock
907	 */
908	struct hlist_node	lr_hash;
909
910	/** Spinlock to protect locks under this resource. */
911	spinlock_t		lr_lock;
912
913	/**
914	 * protected by lr_lock
915	 * @{ */
916	/** List of locks in granted state */
917	struct list_head		lr_granted;
918	/** List of locks waiting to change their granted mode (converted) */
919	struct list_head		lr_converting;
920	/**
921	 * List of locks that could not be granted due to conflicts and
922	 * that are waiting for conflicts to go away */
923	struct list_head		lr_waiting;
924	/** @} */
925
926	/* XXX No longer needed? Remove ASAP */
927	ldlm_mode_t		lr_most_restr;
928
929	/** Type of locks this resource can hold. Only one type per resource. */
930	ldlm_type_t		lr_type; /* LDLM_{PLAIN,EXTENT,FLOCK,IBITS} */
931
932	/** Resource name */
933	struct ldlm_res_id	lr_name;
934	/** Reference count for this resource */
935	atomic_t		lr_refcount;
936
937	/**
938	 * Interval trees (only for extent locks) for all modes of this resource
939	 */
940	struct ldlm_interval_tree lr_itree[LCK_MODE_NUM];
941
942	/**
943	 * Server-side-only lock value block elements.
944	 * To serialize lvbo_init.
945	 */
946	struct mutex		lr_lvb_mutex;
947	int			lr_lvb_len;
948	/** protected by lr_lock */
949	void			*lr_lvb_data;
950
951	/** When the resource was considered as contended. */
952	unsigned long		lr_contention_time;
953	/** List of references to this resource. For debugging. */
954	struct lu_ref		lr_reference;
955
956	struct inode		*lr_lvb_inode;
957};
958
959static inline bool ldlm_has_layout(struct ldlm_lock *lock)
960{
961	return lock->l_resource->lr_type == LDLM_IBITS &&
962		lock->l_policy_data.l_inodebits.bits & MDS_INODELOCK_LAYOUT;
963}
964
965static inline char *
966ldlm_ns_name(struct ldlm_namespace *ns)
967{
968	return ns->ns_rs_hash->hs_name;
969}
970
971static inline struct ldlm_namespace *
972ldlm_res_to_ns(struct ldlm_resource *res)
973{
974	return res->lr_ns_bucket->nsb_namespace;
975}
976
977static inline struct ldlm_namespace *
978ldlm_lock_to_ns(struct ldlm_lock *lock)
979{
980	return ldlm_res_to_ns(lock->l_resource);
981}
982
983static inline char *
984ldlm_lock_to_ns_name(struct ldlm_lock *lock)
985{
986	return ldlm_ns_name(ldlm_lock_to_ns(lock));
987}
988
989static inline struct adaptive_timeout *
990ldlm_lock_to_ns_at(struct ldlm_lock *lock)
991{
992	return &lock->l_resource->lr_ns_bucket->nsb_at_estimate;
993}
994
995static inline int ldlm_lvbo_init(struct ldlm_resource *res)
996{
997	struct ldlm_namespace *ns = ldlm_res_to_ns(res);
998
999	if (ns->ns_lvbo != NULL && ns->ns_lvbo->lvbo_init != NULL)
1000		return ns->ns_lvbo->lvbo_init(res);
1001
1002	return 0;
1003}
1004
1005static inline int ldlm_lvbo_size(struct ldlm_lock *lock)
1006{
1007	struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
1008
1009	if (ns->ns_lvbo != NULL && ns->ns_lvbo->lvbo_size != NULL)
1010		return ns->ns_lvbo->lvbo_size(lock);
1011
1012	return 0;
1013}
1014
1015static inline int ldlm_lvbo_fill(struct ldlm_lock *lock, void *buf, int len)
1016{
1017	struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
1018
1019	if (ns->ns_lvbo != NULL) {
1020		LASSERT(ns->ns_lvbo->lvbo_fill != NULL);
1021		return ns->ns_lvbo->lvbo_fill(lock, buf, len);
1022	}
1023	return 0;
1024}
1025
1026struct ldlm_ast_work {
1027	struct ldlm_lock      *w_lock;
1028	int		    w_blocking;
1029	struct ldlm_lock_desc  w_desc;
1030	struct list_head	     w_list;
1031	int		    w_flags;
1032	void		  *w_data;
1033	int		    w_datalen;
1034};
1035
1036/**
1037 * Common ldlm_enqueue parameters
1038 */
1039struct ldlm_enqueue_info {
1040	__u32 ei_type;   /** Type of the lock being enqueued. */
1041	__u32 ei_mode;   /** Mode of the lock being enqueued. */
1042	void *ei_cb_bl;  /** blocking lock callback */
1043	void *ei_cb_cp;  /** lock completion callback */
1044	void *ei_cb_gl;  /** lock glimpse callback */
1045	void *ei_cbdata; /** Data to be passed into callbacks. */
1046};
1047
1048extern struct obd_ops ldlm_obd_ops;
1049
1050extern char *ldlm_lockname[];
1051extern char *ldlm_typename[];
1052extern char *ldlm_it2str(int it);
1053
1054/**
1055 * Just a fancy CDEBUG call with log level preset to LDLM_DEBUG.
1056 * For the cases where we do not have actual lock to print along
1057 * with a debugging message that is ldlm-related
1058 */
1059#define LDLM_DEBUG_NOLOCK(format, a...)			\
1060	CDEBUG(D_DLMTRACE, "### " format "\n" , ##a)
1061
1062/**
1063 * Support function for lock information printing into debug logs.
1064 * \see LDLM_DEBUG
1065 */
1066#define ldlm_lock_debug(msgdata, mask, cdls, lock, fmt, a...) do {      \
1067	CFS_CHECK_STACK(msgdata, mask, cdls);			   \
1068									\
1069	if (((mask) & D_CANTMASK) != 0 ||			       \
1070	    ((libcfs_debug & (mask)) != 0 &&			    \
1071	     (libcfs_subsystem_debug & DEBUG_SUBSYSTEM) != 0))	  \
1072		_ldlm_lock_debug(lock, msgdata, fmt, ##a);	      \
1073} while (0)
1074
1075void _ldlm_lock_debug(struct ldlm_lock *lock,
1076		      struct libcfs_debug_msg_data *data,
1077		      const char *fmt, ...)
1078	__attribute__ ((format (printf, 3, 4)));
1079
1080/**
1081 * Rate-limited version of lock printing function.
1082 */
1083#define LDLM_DEBUG_LIMIT(mask, lock, fmt, a...) do {			 \
1084	static struct cfs_debug_limit_state _ldlm_cdls;			   \
1085	LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, &_ldlm_cdls);	      \
1086	ldlm_lock_debug(&msgdata, mask, &_ldlm_cdls, lock, "### " fmt , ##a);\
1087} while (0)
1088
1089#define LDLM_ERROR(lock, fmt, a...) LDLM_DEBUG_LIMIT(D_ERROR, lock, fmt, ## a)
1090#define LDLM_WARN(lock, fmt, a...)  LDLM_DEBUG_LIMIT(D_WARNING, lock, fmt, ## a)
1091
1092/** Non-rate-limited lock printing function for debugging purposes. */
1093#define LDLM_DEBUG(lock, fmt, a...)   do {				  \
1094	if (likely(lock != NULL)) {					    \
1095		LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_DLMTRACE, NULL);      \
1096		ldlm_lock_debug(&msgdata, D_DLMTRACE, NULL, lock,	    \
1097				"### " fmt , ##a);			    \
1098	} else {							    \
1099		LDLM_DEBUG_NOLOCK("no dlm lock: " fmt, ##a);		    \
1100	}								    \
1101} while (0)
1102
1103typedef int (*ldlm_processing_policy)(struct ldlm_lock *lock, __u64 *flags,
1104				      int first_enq, ldlm_error_t *err,
1105				      struct list_head *work_list);
1106
1107/**
1108 * Return values for lock iterators.
1109 * Also used during deciding of lock grants and cancellations.
1110 */
1111#define LDLM_ITER_CONTINUE 1 /* keep iterating */
1112#define LDLM_ITER_STOP     2 /* stop iterating */
1113
1114typedef int (*ldlm_iterator_t)(struct ldlm_lock *, void *);
1115typedef int (*ldlm_res_iterator_t)(struct ldlm_resource *, void *);
1116
1117/** \defgroup ldlm_iterator Lock iterators
1118 *
1119 * LDLM provides for a way to iterate through every lock on a resource or
1120 * namespace or every resource in a namespace.
1121 * @{ */
1122int ldlm_resource_foreach(struct ldlm_resource *res, ldlm_iterator_t iter,
1123			  void *closure);
1124void ldlm_namespace_foreach(struct ldlm_namespace *ns, ldlm_iterator_t iter,
1125			    void *closure);
1126int ldlm_resource_iterate(struct ldlm_namespace *, const struct ldlm_res_id *,
1127			  ldlm_iterator_t iter, void *data);
1128/** @} ldlm_iterator */
1129
1130int ldlm_replay_locks(struct obd_import *imp);
1131
1132/* ldlm_flock.c */
1133int ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data);
1134
1135/* ldlm_extent.c */
1136__u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms);
1137
1138struct ldlm_callback_suite {
1139	ldlm_completion_callback lcs_completion;
1140	ldlm_blocking_callback   lcs_blocking;
1141	ldlm_glimpse_callback    lcs_glimpse;
1142};
1143
1144/* ldlm_lockd.c */
1145int ldlm_del_waiting_lock(struct ldlm_lock *lock);
1146int ldlm_refresh_waiting_lock(struct ldlm_lock *lock, int timeout);
1147int ldlm_get_ref(void);
1148void ldlm_put_ref(void);
1149int ldlm_init_export(struct obd_export *exp);
1150void ldlm_destroy_export(struct obd_export *exp);
1151struct ldlm_lock *ldlm_request_lock(struct ptlrpc_request *req);
1152
1153/* ldlm_lock.c */
1154void ldlm_register_intent(struct ldlm_namespace *ns, ldlm_res_policy arg);
1155void ldlm_lock2handle(const struct ldlm_lock *lock,
1156		      struct lustre_handle *lockh);
1157struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *, __u64 flags);
1158void ldlm_cancel_callback(struct ldlm_lock *);
1159int ldlm_lock_remove_from_lru(struct ldlm_lock *);
1160int ldlm_lock_set_data(struct lustre_handle *, void *);
1161
1162/**
1163 * Obtain a lock reference by its handle.
1164 */
1165static inline struct ldlm_lock *ldlm_handle2lock(const struct lustre_handle *h)
1166{
1167	return __ldlm_handle2lock(h, 0);
1168}
1169
1170#define LDLM_LOCK_REF_DEL(lock) \
1171	lu_ref_del(&lock->l_reference, "handle", current)
1172
1173static inline struct ldlm_lock *
1174ldlm_handle2lock_long(const struct lustre_handle *h, __u64 flags)
1175{
1176	struct ldlm_lock *lock;
1177
1178	lock = __ldlm_handle2lock(h, flags);
1179	if (lock != NULL)
1180		LDLM_LOCK_REF_DEL(lock);
1181	return lock;
1182}
1183
1184/**
1185 * Update Lock Value Block Operations (LVBO) on a resource taking into account
1186 * data from request \a r
1187 */
1188static inline int ldlm_res_lvbo_update(struct ldlm_resource *res,
1189				       struct ptlrpc_request *r, int increase)
1190{
1191	if (ldlm_res_to_ns(res)->ns_lvbo &&
1192	    ldlm_res_to_ns(res)->ns_lvbo->lvbo_update) {
1193		return ldlm_res_to_ns(res)->ns_lvbo->lvbo_update(res, r,
1194								 increase);
1195	}
1196	return 0;
1197}
1198
1199int ldlm_error2errno(ldlm_error_t error);
1200ldlm_error_t ldlm_errno2error(int err_no); /* don't call it `errno': this
1201					    * confuses user-space. */
1202#if LUSTRE_TRACKS_LOCK_EXP_REFS
1203void ldlm_dump_export_locks(struct obd_export *exp);
1204#endif
1205
1206/**
1207 * Release a temporary lock reference obtained by ldlm_handle2lock() or
1208 * __ldlm_handle2lock().
1209 */
1210#define LDLM_LOCK_PUT(lock)		     \
1211do {					    \
1212	LDLM_LOCK_REF_DEL(lock);		\
1213	/*LDLM_DEBUG((lock), "put");*/	  \
1214	ldlm_lock_put(lock);		    \
1215} while (0)
1216
1217/**
1218 * Release a lock reference obtained by some other means (see
1219 * LDLM_LOCK_PUT()).
1220 */
1221#define LDLM_LOCK_RELEASE(lock)		 \
1222do {					    \
1223	/*LDLM_DEBUG((lock), "put");*/	  \
1224	ldlm_lock_put(lock);		    \
1225} while (0)
1226
1227#define LDLM_LOCK_GET(lock)		     \
1228({					      \
1229	ldlm_lock_get(lock);		    \
1230	/*LDLM_DEBUG((lock), "get");*/	  \
1231	lock;				   \
1232})
1233
1234#define ldlm_lock_list_put(head, member, count)		     \
1235({								  \
1236	struct ldlm_lock *_lock, *_next;			    \
1237	int c = count;					      \
1238	list_for_each_entry_safe(_lock, _next, head, member) {  \
1239		if (c-- == 0)				       \
1240			break;				      \
1241		list_del_init(&_lock->member);		  \
1242		LDLM_LOCK_RELEASE(_lock);			   \
1243	}							   \
1244	LASSERT(c <= 0);					    \
1245})
1246
1247struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
1248void ldlm_lock_put(struct ldlm_lock *lock);
1249void ldlm_lock_destroy(struct ldlm_lock *lock);
1250void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc);
1251void ldlm_lock_addref(struct lustre_handle *lockh, __u32 mode);
1252int  ldlm_lock_addref_try(struct lustre_handle *lockh, __u32 mode);
1253void ldlm_lock_decref(struct lustre_handle *lockh, __u32 mode);
1254void ldlm_lock_decref_and_cancel(struct lustre_handle *lockh, __u32 mode);
1255void ldlm_lock_fail_match_locked(struct ldlm_lock *lock);
1256void ldlm_lock_fail_match(struct ldlm_lock *lock);
1257void ldlm_lock_allow_match(struct ldlm_lock *lock);
1258void ldlm_lock_allow_match_locked(struct ldlm_lock *lock);
1259ldlm_mode_t ldlm_lock_match(struct ldlm_namespace *ns, __u64 flags,
1260			    const struct ldlm_res_id *, ldlm_type_t type,
1261			    ldlm_policy_data_t *, ldlm_mode_t mode,
1262			    struct lustre_handle *, int unref);
1263ldlm_mode_t ldlm_revalidate_lock_handle(struct lustre_handle *lockh,
1264					__u64 *bits);
1265struct ldlm_resource *ldlm_lock_convert(struct ldlm_lock *lock, int new_mode,
1266					__u32 *flags);
1267void ldlm_lock_downgrade(struct ldlm_lock *lock, int new_mode);
1268void ldlm_lock_cancel(struct ldlm_lock *lock);
1269void ldlm_reprocess_all(struct ldlm_resource *res);
1270void ldlm_reprocess_all_ns(struct ldlm_namespace *ns);
1271void ldlm_lock_dump_handle(int level, struct lustre_handle *);
1272void ldlm_unlink_lock_skiplist(struct ldlm_lock *req);
1273
1274/* resource.c */
1275struct ldlm_namespace *
1276ldlm_namespace_new(struct obd_device *obd, char *name,
1277		   ldlm_side_t client, ldlm_appetite_t apt,
1278		   ldlm_ns_type_t ns_type);
1279int ldlm_namespace_cleanup(struct ldlm_namespace *ns, __u64 flags);
1280void ldlm_namespace_free(struct ldlm_namespace *ns,
1281			 struct obd_import *imp, int force);
1282void ldlm_namespace_register(struct ldlm_namespace *ns, ldlm_side_t client);
1283void ldlm_namespace_unregister(struct ldlm_namespace *ns, ldlm_side_t client);
1284void ldlm_namespace_get(struct ldlm_namespace *ns);
1285void ldlm_namespace_put(struct ldlm_namespace *ns);
1286#if defined (CONFIG_PROC_FS)
1287int ldlm_proc_setup(void);
1288void ldlm_proc_cleanup(void);
1289#else
1290static inline int ldlm_proc_setup(void) { return 0; }
1291static inline void ldlm_proc_cleanup(void) {}
1292#endif
1293
1294/* resource.c - internal */
1295struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
1296					struct ldlm_resource *parent,
1297					const struct ldlm_res_id *,
1298					ldlm_type_t type, int create);
1299struct ldlm_resource *ldlm_resource_getref(struct ldlm_resource *res);
1300int ldlm_resource_putref(struct ldlm_resource *res);
1301void ldlm_resource_add_lock(struct ldlm_resource *res,
1302			    struct list_head *head,
1303			    struct ldlm_lock *lock);
1304void ldlm_resource_unlink_lock(struct ldlm_lock *lock);
1305void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc);
1306void ldlm_dump_all_namespaces(ldlm_side_t client, int level);
1307void ldlm_namespace_dump(int level, struct ldlm_namespace *);
1308void ldlm_resource_dump(int level, struct ldlm_resource *);
1309int ldlm_lock_change_resource(struct ldlm_namespace *, struct ldlm_lock *,
1310			      const struct ldlm_res_id *);
1311
1312#define LDLM_RESOURCE_ADDREF(res) do {				  \
1313	lu_ref_add_atomic(&(res)->lr_reference, __func__, current);  \
1314} while (0)
1315
1316#define LDLM_RESOURCE_DELREF(res) do {				  \
1317	lu_ref_del(&(res)->lr_reference, __func__, current);	  \
1318} while (0)
1319
1320/* ldlm_request.c */
1321int ldlm_expired_completion_wait(void *data);
1322/** \defgroup ldlm_local_ast Default AST handlers for local locks
1323 * These AST handlers are typically used for server-side local locks and are
1324 * also used by client-side lock handlers to perform minimum level base
1325 * processing.
1326 * @{ */
1327int ldlm_blocking_ast_nocheck(struct ldlm_lock *lock);
1328int ldlm_blocking_ast(struct ldlm_lock *lock, struct ldlm_lock_desc *desc,
1329		      void *data, int flag);
1330int ldlm_glimpse_ast(struct ldlm_lock *lock, void *reqp);
1331int ldlm_completion_ast_async(struct ldlm_lock *lock, __u64 flags, void *data);
1332int ldlm_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data);
1333/** @} ldlm_local_ast */
1334
1335/** \defgroup ldlm_cli_api API to operate on locks from actual LDLM users.
1336 * These are typically used by client and server (*_local versions)
1337 * to obtain and release locks.
1338 * @{ */
1339int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
1340		     struct ldlm_enqueue_info *einfo,
1341		     const struct ldlm_res_id *res_id,
1342		     ldlm_policy_data_t const *policy, __u64 *flags,
1343		     void *lvb, __u32 lvb_len, enum lvb_type lvb_type,
1344		     struct lustre_handle *lockh, int async);
1345int ldlm_prep_enqueue_req(struct obd_export *exp,
1346			  struct ptlrpc_request *req,
1347			  struct list_head *cancels,
1348			  int count);
1349int ldlm_prep_elc_req(struct obd_export *exp,
1350		      struct ptlrpc_request *req,
1351		      int version, int opc, int canceloff,
1352		      struct list_head *cancels, int count);
1353
1354struct ptlrpc_request *ldlm_enqueue_pack(struct obd_export *exp, int lvb_len);
1355int ldlm_handle_enqueue0(struct ldlm_namespace *ns, struct ptlrpc_request *req,
1356			 const struct ldlm_request *dlm_req,
1357			 const struct ldlm_callback_suite *cbs);
1358int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
1359			  ldlm_type_t type, __u8 with_policy, ldlm_mode_t mode,
1360			  __u64 *flags, void *lvb, __u32 lvb_len,
1361			  struct lustre_handle *lockh, int rc);
1362int ldlm_cli_enqueue_local(struct ldlm_namespace *ns,
1363			   const struct ldlm_res_id *res_id,
1364			   ldlm_type_t type, ldlm_policy_data_t *policy,
1365			   ldlm_mode_t mode, __u64 *flags,
1366			   ldlm_blocking_callback blocking,
1367			   ldlm_completion_callback completion,
1368			   ldlm_glimpse_callback glimpse,
1369			   void *data, __u32 lvb_len, enum lvb_type lvb_type,
1370			   const __u64 *client_cookie,
1371			   struct lustre_handle *lockh);
1372int ldlm_server_ast(struct lustre_handle *lockh, struct ldlm_lock_desc *new,
1373		    void *data, __u32 data_len);
1374int ldlm_cli_convert(struct lustre_handle *, int new_mode, __u32 *flags);
1375int ldlm_cli_update_pool(struct ptlrpc_request *req);
1376int ldlm_cli_cancel(struct lustre_handle *lockh,
1377		    ldlm_cancel_flags_t cancel_flags);
1378int ldlm_cli_cancel_unused(struct ldlm_namespace *, const struct ldlm_res_id *,
1379			   ldlm_cancel_flags_t flags, void *opaque);
1380int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
1381				    const struct ldlm_res_id *res_id,
1382				    ldlm_policy_data_t *policy,
1383				    ldlm_mode_t mode,
1384				    ldlm_cancel_flags_t flags,
1385				    void *opaque);
1386int ldlm_cli_cancel_req(struct obd_export *exp, struct list_head *head,
1387			int count, ldlm_cancel_flags_t flags);
1388int ldlm_cancel_resource_local(struct ldlm_resource *res,
1389			       struct list_head *cancels,
1390			       ldlm_policy_data_t *policy,
1391			       ldlm_mode_t mode, __u64 lock_flags,
1392			       ldlm_cancel_flags_t cancel_flags, void *opaque);
1393int ldlm_cli_cancel_list_local(struct list_head *cancels, int count,
1394			       ldlm_cancel_flags_t flags);
1395int ldlm_cli_cancel_list(struct list_head *head, int count,
1396			 struct ptlrpc_request *req, ldlm_cancel_flags_t flags);
1397/** @} ldlm_cli_api */
1398
1399/* mds/handler.c */
1400/* This has to be here because recursive inclusion sucks. */
1401int intent_disposition(struct ldlm_reply *rep, int flag);
1402void intent_set_disposition(struct ldlm_reply *rep, int flag);
1403
1404
1405/* ioctls for trying requests */
1406#define IOC_LDLM_TYPE		   'f'
1407#define IOC_LDLM_MIN_NR		 40
1408
1409#define IOC_LDLM_TEST		   _IOWR('f', 40, long)
1410#define IOC_LDLM_DUMP		   _IOWR('f', 41, long)
1411#define IOC_LDLM_REGRESS_START	  _IOWR('f', 42, long)
1412#define IOC_LDLM_REGRESS_STOP	   _IOWR('f', 43, long)
1413#define IOC_LDLM_MAX_NR		 43
1414
1415/**
1416 * "Modes" of acquiring lock_res, necessary to tell lockdep that taking more
1417 * than one lock_res is dead-lock safe.
1418 */
1419enum lock_res_type {
1420	LRT_NORMAL,
1421	LRT_NEW
1422};
1423
1424/** Lock resource. */
1425static inline void lock_res(struct ldlm_resource *res)
1426{
1427	spin_lock(&res->lr_lock);
1428}
1429
1430/** Lock resource with a way to instruct lockdep code about nestedness-safe. */
1431static inline void lock_res_nested(struct ldlm_resource *res,
1432				   enum lock_res_type mode)
1433{
1434	spin_lock_nested(&res->lr_lock, mode);
1435}
1436
1437/** Unlock resource. */
1438static inline void unlock_res(struct ldlm_resource *res)
1439{
1440	spin_unlock(&res->lr_lock);
1441}
1442
1443/** Check if resource is already locked, assert if not. */
1444static inline void check_res_locked(struct ldlm_resource *res)
1445{
1446	assert_spin_locked(&res->lr_lock);
1447}
1448
1449struct ldlm_resource * lock_res_and_lock(struct ldlm_lock *lock);
1450void unlock_res_and_lock(struct ldlm_lock *lock);
1451
1452/* ldlm_pool.c */
1453/** \defgroup ldlm_pools Various LDLM pool related functions
1454 * There are not used outside of ldlm.
1455 * @{
1456 */
1457int ldlm_pools_recalc(ldlm_side_t client);
1458int ldlm_pools_init(void);
1459void ldlm_pools_fini(void);
1460
1461int ldlm_pool_init(struct ldlm_pool *pl, struct ldlm_namespace *ns,
1462		   int idx, ldlm_side_t client);
1463int ldlm_pool_shrink(struct ldlm_pool *pl, int nr,
1464		     gfp_t gfp_mask);
1465void ldlm_pool_fini(struct ldlm_pool *pl);
1466int ldlm_pool_setup(struct ldlm_pool *pl, int limit);
1467int ldlm_pool_recalc(struct ldlm_pool *pl);
1468__u32 ldlm_pool_get_lvf(struct ldlm_pool *pl);
1469__u64 ldlm_pool_get_slv(struct ldlm_pool *pl);
1470__u64 ldlm_pool_get_clv(struct ldlm_pool *pl);
1471__u32 ldlm_pool_get_limit(struct ldlm_pool *pl);
1472void ldlm_pool_set_slv(struct ldlm_pool *pl, __u64 slv);
1473void ldlm_pool_set_clv(struct ldlm_pool *pl, __u64 clv);
1474void ldlm_pool_set_limit(struct ldlm_pool *pl, __u32 limit);
1475void ldlm_pool_add(struct ldlm_pool *pl, struct ldlm_lock *lock);
1476void ldlm_pool_del(struct ldlm_pool *pl, struct ldlm_lock *lock);
1477/** @} */
1478
1479#endif
1480/** @} LDLM */
1481