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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.gnu.org/licenses/gpl-2.0.html
19  *
20  * GPL HEADER END
21  */
22 /*
23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
24  * Use is subject to license terms.
25  *
26  * Copyright (c) 2010, 2015, Intel Corporation.
27  */
28 /*
29  * This file is part of Lustre, http://www.lustre.org/
30  * Lustre is a trademark of Sun Microsystems, Inc.
31  */
32 
33 /** \defgroup LDLM Lustre Distributed Lock Manager
34  *
35  * Lustre DLM is based on VAX DLM.
36  * Its two main roles are:
37  *   - To provide locking assuring consistency of data on all Lustre nodes.
38  *   - To allow clients to cache state protected by a lock by holding the
39  *     lock until a conflicting lock is requested or it is expired by the LRU.
40  *
41  * @{
42  */
43 
44 #ifndef _LUSTRE_DLM_H__
45 #define _LUSTRE_DLM_H__
46 
47 #include <lustre_lib.h>
48 #include <lustre_net.h>
49 #include <lustre_import.h>
50 #include <lustre_handles.h>
51 #include <interval_tree.h>	/* for interval_node{}, ldlm_extent */
52 #include <lu_ref.h>
53 
54 #include "lustre_dlm_flags.h"
55 
56 struct obd_ops;
57 struct obd_device;
58 
59 #define OBD_LDLM_DEVICENAME  "ldlm"
60 
61 #define LDLM_DEFAULT_LRU_SIZE (100 * num_online_cpus())
62 #define LDLM_DEFAULT_MAX_ALIVE (cfs_time_seconds(3900)) /* 65 min */
63 #define LDLM_DEFAULT_PARALLEL_AST_LIMIT 1024
64 
65 /**
66  * LDLM non-error return states
67  */
68 enum ldlm_error {
69 	ELDLM_OK = 0,
70 	ELDLM_LOCK_MATCHED = 1,
71 
72 	ELDLM_LOCK_CHANGED = 300,
73 	ELDLM_LOCK_ABORTED = 301,
74 	ELDLM_LOCK_REPLACED = 302,
75 	ELDLM_NO_LOCK_DATA = 303,
76 	ELDLM_LOCK_WOULDBLOCK = 304,
77 
78 	ELDLM_NAMESPACE_EXISTS = 400,
79 	ELDLM_BAD_NAMESPACE    = 401
80 };
81 
82 /**
83  * LDLM namespace type.
84  * The "client" type is actually an indication that this is a narrow local view
85  * into complete namespace on the server. Such namespaces cannot make any
86  * decisions about lack of conflicts or do any autonomous lock granting without
87  * first speaking to a server.
88  */
89 enum ldlm_side {
90 	LDLM_NAMESPACE_SERVER = 1 << 0,
91 	LDLM_NAMESPACE_CLIENT = 1 << 1
92 };
93 
94 /**
95  * The blocking callback is overloaded to perform two functions.  These flags
96  * indicate which operation should be performed.
97  */
98 #define LDLM_CB_BLOCKING    1
99 #define LDLM_CB_CANCELING   2
100 
101 /**
102  * \name Lock Compatibility Matrix.
103  *
104  * A lock has both a type (extent, flock, inode bits, or plain) and a mode.
105  * Lock types are described in their respective implementation files:
106  * ldlm_{extent,flock,inodebits,plain}.c.
107  *
108  * There are six lock modes along with a compatibility matrix to indicate if
109  * two locks are compatible.
110  *
111  * - EX: Exclusive mode. Before a new file is created, MDS requests EX lock
112  *   on the parent.
113  * - PW: Protective Write (normal write) mode. When a client requests a write
114  *   lock from an OST, a lock with PW mode will be issued.
115  * - PR: Protective Read (normal read) mode. When a client requests a read from
116  *   an OST, a lock with PR mode will be issued. Also, if the client opens a
117  *   file for execution, it is granted a lock with PR mode.
118  * - CW: Concurrent Write mode. The type of lock that the MDS grants if a client
119  *   requests a write lock during a file open operation.
120  * - CR Concurrent Read mode. When a client performs a path lookup, MDS grants
121  *   an inodebit lock with the CR mode on the intermediate path component.
122  * - NL Null mode.
123  *
124  * <PRE>
125  *       NL  CR  CW  PR  PW  EX
126  *  NL    1   1   1   1   1   1
127  *  CR    1   1   1   1   1   0
128  *  CW    1   1   1   0   0   0
129  *  PR    1   1   0   1   0   0
130  *  PW    1   1   0   0   0   0
131  *  EX    1   0   0   0   0   0
132  * </PRE>
133  */
134 /** @{ */
135 #define LCK_COMPAT_EX  LCK_NL
136 #define LCK_COMPAT_PW  (LCK_COMPAT_EX | LCK_CR)
137 #define LCK_COMPAT_PR  (LCK_COMPAT_PW | LCK_PR)
138 #define LCK_COMPAT_CW  (LCK_COMPAT_PW | LCK_CW)
139 #define LCK_COMPAT_CR  (LCK_COMPAT_CW | LCK_PR | LCK_PW)
140 #define LCK_COMPAT_NL  (LCK_COMPAT_CR | LCK_EX | LCK_GROUP)
141 #define LCK_COMPAT_GROUP  (LCK_GROUP | LCK_NL)
142 #define LCK_COMPAT_COS (LCK_COS)
143 /** @} Lock Compatibility Matrix */
144 
145 extern enum ldlm_mode lck_compat_array[];
146 
lockmode_verify(enum ldlm_mode mode)147 static inline void lockmode_verify(enum ldlm_mode mode)
148 {
149 	LASSERT(mode > LCK_MINMODE && mode < LCK_MAXMODE);
150 }
151 
lockmode_compat(enum ldlm_mode exist_mode,enum ldlm_mode new_mode)152 static inline int lockmode_compat(enum ldlm_mode exist_mode,
153 				  enum ldlm_mode new_mode)
154 {
155 	return (lck_compat_array[exist_mode] & new_mode);
156 }
157 
158 /*
159  *
160  * cluster name spaces
161  *
162  */
163 
164 #define DLM_OST_NAMESPACE 1
165 #define DLM_MDS_NAMESPACE 2
166 
167 /* XXX
168    - do we just separate this by security domains and use a prefix for
169      multiple namespaces in the same domain?
170    -
171 */
172 
173 /**
174  * Locking rules for LDLM:
175  *
176  * lr_lock
177  *
178  * lr_lock
179  *     waiting_locks_spinlock
180  *
181  * lr_lock
182  *     led_lock
183  *
184  * lr_lock
185  *     ns_lock
186  *
187  * lr_lvb_mutex
188  *     lr_lock
189  *
190  */
191 
192 struct ldlm_pool;
193 struct ldlm_lock;
194 struct ldlm_resource;
195 struct ldlm_namespace;
196 
197 /**
198  * Operations on LDLM pools.
199  * LDLM pool is a pool of locks in the namespace without any implicitly
200  * specified limits.
201  * Locks in the pool are organized in LRU.
202  * Local memory pressure or server instructions (e.g. mempressure on server)
203  * can trigger freeing of locks from the pool
204  */
205 struct ldlm_pool_ops {
206 	/** Recalculate pool \a pl usage */
207 	int (*po_recalc)(struct ldlm_pool *pl);
208 	/** Cancel at least \a nr locks from pool \a pl */
209 	int (*po_shrink)(struct ldlm_pool *pl, int nr,
210 			 gfp_t gfp_mask);
211 };
212 
213 /** One second for pools thread check interval. Each pool has own period. */
214 #define LDLM_POOLS_THREAD_PERIOD (1)
215 
216 /** ~6% margin for modest pools. See ldlm_pool.c for details. */
217 #define LDLM_POOLS_MODEST_MARGIN_SHIFT (4)
218 
219 /** Default recalc period for server side pools in sec. */
220 #define LDLM_POOL_SRV_DEF_RECALC_PERIOD (1)
221 
222 /** Default recalc period for client side pools in sec. */
223 #define LDLM_POOL_CLI_DEF_RECALC_PERIOD (10)
224 
225 /**
226  * LDLM pool structure to track granted locks.
227  * For purposes of determining when to release locks on e.g. memory pressure.
228  * This feature is commonly referred to as lru_resize.
229  */
230 struct ldlm_pool {
231 	/** Pool debugfs directory. */
232 	struct dentry		*pl_debugfs_entry;
233 	/** Pool name, must be long enough to hold compound proc entry name. */
234 	char			pl_name[100];
235 	/** Lock for protecting SLV/CLV updates. */
236 	spinlock_t		pl_lock;
237 	/** Number of allowed locks in in pool, both, client and server side. */
238 	atomic_t		pl_limit;
239 	/** Number of granted locks in */
240 	atomic_t		pl_granted;
241 	/** Grant rate per T. */
242 	atomic_t		pl_grant_rate;
243 	/** Cancel rate per T. */
244 	atomic_t		pl_cancel_rate;
245 	/** Server lock volume (SLV). Protected by pl_lock. */
246 	__u64			pl_server_lock_volume;
247 	/** Current biggest client lock volume. Protected by pl_lock. */
248 	__u64			pl_client_lock_volume;
249 	/** Lock volume factor. SLV on client is calculated as following:
250 	 *  server_slv * lock_volume_factor.
251 	 */
252 	atomic_t		pl_lock_volume_factor;
253 	/** Time when last SLV from server was obtained. */
254 	time64_t		pl_recalc_time;
255 	/** Recalculation period for pool. */
256 	time64_t		pl_recalc_period;
257 	/** Recalculation and shrink operations. */
258 	const struct ldlm_pool_ops	*pl_ops;
259 	/** Number of planned locks for next period. */
260 	int			pl_grant_plan;
261 	/** Pool statistics. */
262 	struct lprocfs_stats	*pl_stats;
263 
264 	/* sysfs object */
265 	struct kobject		 pl_kobj;
266 	struct completion	 pl_kobj_unregister;
267 };
268 
269 typedef int (*ldlm_cancel_cbt)(struct ldlm_lock *lock);
270 
271 /**
272  * LVB operations.
273  * LVB is Lock Value Block. This is a special opaque (to LDLM) value that could
274  * be associated with an LDLM lock and transferred from client to server and
275  * back.
276  *
277  * Currently LVBs are used by:
278  *  - OSC-OST code to maintain current object size/times
279  *  - layout lock code to return the layout when the layout lock is granted
280  */
281 struct ldlm_valblock_ops {
282 	int (*lvbo_init)(struct ldlm_resource *res);
283 	int (*lvbo_update)(struct ldlm_resource *res,
284 			   struct ptlrpc_request *r,
285 			   int increase);
286 	int (*lvbo_free)(struct ldlm_resource *res);
287 	/* Return size of lvb data appropriate RPC size can be reserved */
288 	int (*lvbo_size)(struct ldlm_lock *lock);
289 	/* Called to fill in lvb data to RPC buffer @buf */
290 	int (*lvbo_fill)(struct ldlm_lock *lock, void *buf, int buflen);
291 };
292 
293 /**
294  * LDLM pools related, type of lock pool in the namespace.
295  * Greedy means release cached locks aggressively
296  */
297 enum ldlm_appetite {
298 	LDLM_NAMESPACE_GREEDY = 1 << 0,
299 	LDLM_NAMESPACE_MODEST = 1 << 1
300 };
301 
302 struct ldlm_ns_bucket {
303 	/** back pointer to namespace */
304 	struct ldlm_namespace      *nsb_namespace;
305 	/**
306 	 * Estimated lock callback time.  Used by adaptive timeout code to
307 	 * avoid spurious client evictions due to unresponsiveness when in
308 	 * fact the network or overall system load is at fault
309 	 */
310 	struct adaptive_timeout     nsb_at_estimate;
311 };
312 
313 enum {
314 	/** LDLM namespace lock stats */
315 	LDLM_NSS_LOCKS	  = 0,
316 	LDLM_NSS_LAST
317 };
318 
319 enum ldlm_ns_type {
320 	/** invalid type */
321 	LDLM_NS_TYPE_UNKNOWN    = 0,
322 	/** mdc namespace */
323 	LDLM_NS_TYPE_MDC,
324 	/** mds namespace */
325 	LDLM_NS_TYPE_MDT,
326 	/** osc namespace */
327 	LDLM_NS_TYPE_OSC,
328 	/** ost namespace */
329 	LDLM_NS_TYPE_OST,
330 	/** mgc namespace */
331 	LDLM_NS_TYPE_MGC,
332 	/** mgs namespace */
333 	LDLM_NS_TYPE_MGT,
334 };
335 
336 /**
337  * LDLM Namespace.
338  *
339  * Namespace serves to contain locks related to a particular service.
340  * There are two kinds of namespaces:
341  * - Server namespace has knowledge of all locks and is therefore authoritative
342  *   to make decisions like what locks could be granted and what conflicts
343  *   exist during new lock enqueue.
344  * - Client namespace only has limited knowledge about locks in the namespace,
345  *   only seeing locks held by the client.
346  *
347  * Every Lustre service has one server namespace present on the server serving
348  * that service. Every client connected to the service has a client namespace
349  * for it.
350  * Every lock obtained by client in that namespace is actually represented by
351  * two in-memory locks. One on the server and one on the client. The locks are
352  * linked by a special cookie by which one node can tell to the other which lock
353  * it actually means during communications. Such locks are called remote locks.
354  * The locks held by server only without any reference to a client are called
355  * local locks.
356  */
357 struct ldlm_namespace {
358 	/** Backward link to OBD, required for LDLM pool to store new SLV. */
359 	struct obd_device	*ns_obd;
360 
361 	/** Flag indicating if namespace is on client instead of server */
362 	enum ldlm_side		ns_client;
363 
364 	/** Resource hash table for namespace. */
365 	struct cfs_hash		*ns_rs_hash;
366 
367 	/** serialize */
368 	spinlock_t		ns_lock;
369 
370 	/** big refcount (by bucket) */
371 	atomic_t		ns_bref;
372 
373 	/**
374 	 * Namespace connect flags supported by server (may be changed via
375 	 * sysfs, LRU resize may be disabled/enabled).
376 	 */
377 	__u64			ns_connect_flags;
378 
379 	/** Client side original connect flags supported by server. */
380 	__u64			ns_orig_connect_flags;
381 
382 	/* namespace debugfs dir entry */
383 	struct dentry		*ns_debugfs_entry;
384 
385 	/**
386 	 * Position in global namespace list linking all namespaces on
387 	 * the node.
388 	 */
389 	struct list_head		ns_list_chain;
390 
391 	/**
392 	 * List of unused locks for this namespace. This list is also called
393 	 * LRU lock list.
394 	 * Unused locks are locks with zero reader/writer reference counts.
395 	 * This list is only used on clients for lock caching purposes.
396 	 * When we want to release some locks voluntarily or if server wants
397 	 * us to release some locks due to e.g. memory pressure, we take locks
398 	 * to release from the head of this list.
399 	 * Locks are linked via l_lru field in \see struct ldlm_lock.
400 	 */
401 	struct list_head		ns_unused_list;
402 	/** Number of locks in the LRU list above */
403 	int			ns_nr_unused;
404 
405 	/**
406 	 * Maximum number of locks permitted in the LRU. If 0, means locks
407 	 * are managed by pools and there is no preset limit, rather it is all
408 	 * controlled by available memory on this client and on server.
409 	 */
410 	unsigned int		ns_max_unused;
411 	/** Maximum allowed age (last used time) for locks in the LRU */
412 	unsigned int		ns_max_age;
413 
414 	/**
415 	 * Used to rate-limit ldlm_namespace_dump calls.
416 	 * \see ldlm_namespace_dump. Increased by 10 seconds every time
417 	 * it is called.
418 	 */
419 	unsigned long		ns_next_dump;
420 
421 	/**
422 	 * LVB operations for this namespace.
423 	 * \see struct ldlm_valblock_ops
424 	 */
425 	struct ldlm_valblock_ops *ns_lvbo;
426 
427 	/**
428 	 * Used by filter code to store pointer to OBD of the service.
429 	 * Should be dropped in favor of \a ns_obd
430 	 */
431 	void			*ns_lvbp;
432 
433 	/**
434 	 * Wait queue used by __ldlm_namespace_free. Gets woken up every time
435 	 * a resource is removed.
436 	 */
437 	wait_queue_head_t		ns_waitq;
438 	/** LDLM pool structure for this namespace */
439 	struct ldlm_pool	ns_pool;
440 	/** Definition of how eagerly unused locks will be released from LRU */
441 	enum ldlm_appetite	ns_appetite;
442 
443 	/** Limit of parallel AST RPC count. */
444 	unsigned		ns_max_parallel_ast;
445 
446 	/**
447 	 * Callback to check if a lock is good to be canceled by ELC or
448 	 * during recovery.
449 	 */
450 	ldlm_cancel_cbt		ns_cancel;
451 
452 	/** LDLM lock stats */
453 	struct lprocfs_stats	*ns_stats;
454 
455 	/**
456 	 * Flag to indicate namespace is being freed. Used to determine if
457 	 * recalculation of LDLM pool statistics should be skipped.
458 	 */
459 	unsigned		ns_stopping:1;
460 
461 	struct kobject		ns_kobj; /* sysfs object */
462 	struct completion	ns_kobj_unregister;
463 };
464 
465 /**
466  * Returns 1 if namespace \a ns supports early lock cancel (ELC).
467  */
ns_connect_cancelset(struct ldlm_namespace * ns)468 static inline int ns_connect_cancelset(struct ldlm_namespace *ns)
469 {
470 	return !!(ns->ns_connect_flags & OBD_CONNECT_CANCELSET);
471 }
472 
473 /**
474  * Returns 1 if this namespace supports lru_resize.
475  */
ns_connect_lru_resize(struct ldlm_namespace * ns)476 static inline int ns_connect_lru_resize(struct ldlm_namespace *ns)
477 {
478 	return !!(ns->ns_connect_flags & OBD_CONNECT_LRU_RESIZE);
479 }
480 
ns_register_cancel(struct ldlm_namespace * ns,ldlm_cancel_cbt arg)481 static inline void ns_register_cancel(struct ldlm_namespace *ns,
482 				      ldlm_cancel_cbt arg)
483 {
484 	ns->ns_cancel = arg;
485 }
486 
487 struct ldlm_lock;
488 
489 /** Type for blocking callback function of a lock. */
490 typedef int (*ldlm_blocking_callback)(struct ldlm_lock *lock,
491 				      struct ldlm_lock_desc *new, void *data,
492 				      int flag);
493 /** Type for completion callback function of a lock. */
494 typedef int (*ldlm_completion_callback)(struct ldlm_lock *lock, __u64 flags,
495 					void *data);
496 /** Type for glimpse callback function of a lock. */
497 typedef int (*ldlm_glimpse_callback)(struct ldlm_lock *lock, void *data);
498 
499 /** Work list for sending GL ASTs to multiple locks. */
500 struct ldlm_glimpse_work {
501 	struct ldlm_lock	*gl_lock; /* lock to glimpse */
502 	struct list_head		 gl_list; /* linkage to other gl work structs */
503 	__u32			 gl_flags;/* see LDLM_GL_WORK_* below */
504 	union ldlm_gl_desc	*gl_desc; /* glimpse descriptor to be packed in
505 					   * glimpse callback request
506 					   */
507 };
508 
509 /** The ldlm_glimpse_work is allocated on the stack and should not be freed. */
510 #define LDLM_GL_WORK_NOFREE 0x1
511 
512 /** Interval node data for each LDLM_EXTENT lock. */
513 struct ldlm_interval {
514 	struct interval_node	li_node;  /* node for tree management */
515 	struct list_head	li_group; /* the locks which have the same
516 					   * policy - group of the policy
517 					   */
518 };
519 
520 #define to_ldlm_interval(n) container_of(n, struct ldlm_interval, li_node)
521 
522 /**
523  * Interval tree for extent locks.
524  * The interval tree must be accessed under the resource lock.
525  * Interval trees are used for granted extent locks to speed up conflicts
526  * lookup. See ldlm/interval_tree.c for more details.
527  */
528 struct ldlm_interval_tree {
529 	/** Tree size. */
530 	int			lit_size;
531 	enum ldlm_mode		lit_mode;  /* lock mode */
532 	struct interval_node	*lit_root; /* actual ldlm_interval */
533 };
534 
535 /** Whether to track references to exports by LDLM locks. */
536 #define LUSTRE_TRACKS_LOCK_EXP_REFS (0)
537 
538 /** Cancel flags. */
539 enum ldlm_cancel_flags {
540 	LCF_ASYNC      = 0x1, /* Cancel locks asynchronously. */
541 	LCF_LOCAL      = 0x2, /* Cancel locks locally, not notifing server */
542 	LCF_BL_AST     = 0x4, /* Cancel locks marked as LDLM_FL_BL_AST
543 			       * in the same RPC
544 			       */
545 };
546 
547 struct ldlm_flock {
548 	__u64 start;
549 	__u64 end;
550 	__u64 owner;
551 	__u64 blocking_owner;
552 	struct obd_export *blocking_export;
553 	__u32 pid;
554 };
555 
556 union ldlm_policy_data {
557 	struct ldlm_extent l_extent;
558 	struct ldlm_flock l_flock;
559 	struct ldlm_inodebits l_inodebits;
560 };
561 
562 void ldlm_convert_policy_to_local(struct obd_export *exp, enum ldlm_type type,
563 				  const union ldlm_wire_policy_data *wpolicy,
564 				  union ldlm_policy_data *lpolicy);
565 
566 enum lvb_type {
567 	LVB_T_NONE	= 0,
568 	LVB_T_OST	= 1,
569 	LVB_T_LQUOTA	= 2,
570 	LVB_T_LAYOUT	= 3,
571 };
572 
573 /**
574  * LDLM_GID_ANY is used to match any group id in ldlm_lock_match().
575  */
576 #define LDLM_GID_ANY	((__u64)-1)
577 
578 /**
579  * LDLM lock structure
580  *
581  * Represents a single LDLM lock and its state in memory. Each lock is
582  * associated with a single ldlm_resource, the object which is being
583  * locked. There may be multiple ldlm_locks on a single resource,
584  * depending on the lock type and whether the locks are conflicting or
585  * not.
586  */
587 struct ldlm_lock {
588 	/**
589 	 * Local lock handle.
590 	 * When remote side wants to tell us about a lock, they address
591 	 * it by this opaque handle.  The handle does not hold a
592 	 * reference on the ldlm_lock, so it can be safely passed to
593 	 * other threads or nodes. When the lock needs to be accessed
594 	 * from the handle, it is looked up again in the lock table, and
595 	 * may no longer exist.
596 	 *
597 	 * Must be first in the structure.
598 	 */
599 	struct portals_handle	l_handle;
600 	/**
601 	 * Lock reference count.
602 	 * This is how many users have pointers to actual structure, so that
603 	 * we do not accidentally free lock structure that is in use.
604 	 */
605 	atomic_t		l_refc;
606 	/**
607 	 * Internal spinlock protects l_resource.  We should hold this lock
608 	 * first before taking res_lock.
609 	 */
610 	spinlock_t		l_lock;
611 	/**
612 	 * Pointer to actual resource this lock is in.
613 	 * ldlm_lock_change_resource() can change this.
614 	 */
615 	struct ldlm_resource	*l_resource;
616 	/**
617 	 * List item for client side LRU list.
618 	 * Protected by ns_lock in struct ldlm_namespace.
619 	 */
620 	struct list_head		l_lru;
621 	/**
622 	 * Linkage to resource's lock queues according to current lock state.
623 	 * (could be granted, waiting or converting)
624 	 * Protected by lr_lock in struct ldlm_resource.
625 	 */
626 	struct list_head		l_res_link;
627 	/**
628 	 * Tree node for ldlm_extent.
629 	 */
630 	struct ldlm_interval	*l_tree_node;
631 	/**
632 	 * Per export hash of locks.
633 	 * Protected by per-bucket exp->exp_lock_hash locks.
634 	 */
635 	struct hlist_node	l_exp_hash;
636 	/**
637 	 * Per export hash of flock locks.
638 	 * Protected by per-bucket exp->exp_flock_hash locks.
639 	 */
640 	struct hlist_node	l_exp_flock_hash;
641 	/**
642 	 * Requested mode.
643 	 * Protected by lr_lock.
644 	 */
645 	enum ldlm_mode		l_req_mode;
646 	/**
647 	 * Granted mode, also protected by lr_lock.
648 	 */
649 	enum ldlm_mode		l_granted_mode;
650 	/** Lock completion handler pointer. Called when lock is granted. */
651 	ldlm_completion_callback l_completion_ast;
652 	/**
653 	 * Lock blocking AST handler pointer.
654 	 * It plays two roles:
655 	 * - as a notification of an attempt to queue a conflicting lock (once)
656 	 * - as a notification when the lock is being cancelled.
657 	 *
658 	 * As such it's typically called twice: once for the initial conflict
659 	 * and then once more when the last user went away and the lock is
660 	 * cancelled (could happen recursively).
661 	 */
662 	ldlm_blocking_callback	l_blocking_ast;
663 	/**
664 	 * Lock glimpse handler.
665 	 * Glimpse handler is used to obtain LVB updates from a client by
666 	 * server
667 	 */
668 	ldlm_glimpse_callback	l_glimpse_ast;
669 
670 	/**
671 	 * Lock export.
672 	 * This is a pointer to actual client export for locks that were granted
673 	 * to clients. Used server-side.
674 	 */
675 	struct obd_export	*l_export;
676 	/**
677 	 * Lock connection export.
678 	 * Pointer to server export on a client.
679 	 */
680 	struct obd_export	*l_conn_export;
681 
682 	/**
683 	 * Remote lock handle.
684 	 * If the lock is remote, this is the handle of the other side lock
685 	 * (l_handle)
686 	 */
687 	struct lustre_handle	l_remote_handle;
688 
689 	/**
690 	 * Representation of private data specific for a lock type.
691 	 * Examples are: extent range for extent lock or bitmask for ibits locks
692 	 */
693 	union ldlm_policy_data	l_policy_data;
694 
695 	/**
696 	 * Lock state flags. Protected by lr_lock.
697 	 * \see lustre_dlm_flags.h where the bits are defined.
698 	 */
699 	__u64			l_flags;
700 
701 	/**
702 	 * Lock r/w usage counters.
703 	 * Protected by lr_lock.
704 	 */
705 	__u32			l_readers;
706 	__u32			l_writers;
707 	/**
708 	 * If the lock is granted, a process sleeps on this waitq to learn when
709 	 * it's no longer in use.  If the lock is not granted, a process sleeps
710 	 * on this waitq to learn when it becomes granted.
711 	 */
712 	wait_queue_head_t		l_waitq;
713 
714 	/**
715 	 * Seconds. It will be updated if there is any activity related to
716 	 * the lock, e.g. enqueue the lock or send blocking AST.
717 	 */
718 	time64_t		l_last_activity;
719 
720 	/**
721 	 * Time last used by e.g. being matched by lock match.
722 	 * Jiffies. Should be converted to time if needed.
723 	 */
724 	unsigned long		l_last_used;
725 
726 	/** Originally requested extent for the extent lock. */
727 	struct ldlm_extent	l_req_extent;
728 
729 	/*
730 	 * Client-side-only members.
731 	 */
732 
733 	enum lvb_type	      l_lvb_type;
734 
735 	/**
736 	 * Temporary storage for a LVB received during an enqueue operation.
737 	 */
738 	__u32			l_lvb_len;
739 	void			*l_lvb_data;
740 
741 	/** Private storage for lock user. Opaque to LDLM. */
742 	void			*l_ast_data;
743 
744 	/*
745 	 * Server-side-only members.
746 	 */
747 
748 	/**
749 	 * Connection cookie for the client originating the operation.
750 	 * Used by Commit on Share (COS) code. Currently only used for
751 	 * inodebits locks on MDS.
752 	 */
753 	__u64			l_client_cookie;
754 
755 	/**
756 	 * List item for locks waiting for cancellation from clients.
757 	 * The lists this could be linked into are:
758 	 * waiting_locks_list (protected by waiting_locks_spinlock),
759 	 * then if the lock timed out, it is moved to
760 	 * expired_lock_thread.elt_expired_locks for further processing.
761 	 * Protected by elt_lock.
762 	 */
763 	struct list_head		l_pending_chain;
764 
765 	/**
766 	 * Set when lock is sent a blocking AST. Time in seconds when timeout
767 	 * is reached and client holding this lock could be evicted.
768 	 * This timeout could be further extended by e.g. certain IO activity
769 	 * under this lock.
770 	 * \see ost_rw_prolong_locks
771 	 */
772 	unsigned long		l_callback_timeout;
773 
774 	/** Local PID of process which created this lock. */
775 	__u32			l_pid;
776 
777 	/**
778 	 * Number of times blocking AST was sent for this lock.
779 	 * This is for debugging. Valid values are 0 and 1, if there is an
780 	 * attempt to send blocking AST more than once, an assertion would be
781 	 * hit. \see ldlm_work_bl_ast_lock
782 	 */
783 	int			l_bl_ast_run;
784 	/** List item ldlm_add_ast_work_item() for case of blocking ASTs. */
785 	struct list_head		l_bl_ast;
786 	/** List item ldlm_add_ast_work_item() for case of completion ASTs. */
787 	struct list_head		l_cp_ast;
788 	/** For ldlm_add_ast_work_item() for "revoke" AST used in COS. */
789 	struct list_head		l_rk_ast;
790 
791 	/**
792 	 * Pointer to a conflicting lock that caused blocking AST to be sent
793 	 * for this lock
794 	 */
795 	struct ldlm_lock	*l_blocking_lock;
796 
797 	/**
798 	 * Protected by lr_lock, linkages to "skip lists".
799 	 * For more explanations of skip lists see ldlm/ldlm_inodebits.c
800 	 */
801 	struct list_head		l_sl_mode;
802 	struct list_head		l_sl_policy;
803 
804 	/** Reference tracking structure to debug leaked locks. */
805 	struct lu_ref		l_reference;
806 #if LUSTRE_TRACKS_LOCK_EXP_REFS
807 	/* Debugging stuff for bug 20498, for tracking export references. */
808 	/** number of export references taken */
809 	int			l_exp_refs_nr;
810 	/** link all locks referencing one export */
811 	struct list_head		l_exp_refs_link;
812 	/** referenced export object */
813 	struct obd_export	*l_exp_refs_target;
814 #endif
815 };
816 
817 /**
818  * LDLM resource description.
819  * Basically, resource is a representation for a single object.
820  * Object has a name which is currently 4 64-bit integers. LDLM user is
821  * responsible for creation of a mapping between objects it wants to be
822  * protected and resource names.
823  *
824  * A resource can only hold locks of a single lock type, though there may be
825  * multiple ldlm_locks on a single resource, depending on the lock type and
826  * whether the locks are conflicting or not.
827  */
828 struct ldlm_resource {
829 	struct ldlm_ns_bucket	*lr_ns_bucket;
830 
831 	/**
832 	 * List item for list in namespace hash.
833 	 * protected by ns_lock
834 	 */
835 	struct hlist_node	lr_hash;
836 
837 	/** Spinlock to protect locks under this resource. */
838 	spinlock_t		lr_lock;
839 
840 	/**
841 	 * protected by lr_lock
842 	 * @{
843 	 */
844 	/** List of locks in granted state */
845 	struct list_head		lr_granted;
846 	/**
847 	 * List of locks that could not be granted due to conflicts and
848 	 * that are waiting for conflicts to go away
849 	 */
850 	struct list_head		lr_waiting;
851 	/** @} */
852 
853 	/** Type of locks this resource can hold. Only one type per resource. */
854 	enum ldlm_type		lr_type; /* LDLM_{PLAIN,EXTENT,FLOCK,IBITS} */
855 
856 	/** Resource name */
857 	struct ldlm_res_id	lr_name;
858 	/** Reference count for this resource */
859 	atomic_t		lr_refcount;
860 
861 	/**
862 	 * Interval trees (only for extent locks) for all modes of this resource
863 	 */
864 	struct ldlm_interval_tree lr_itree[LCK_MODE_NUM];
865 
866 	/**
867 	 * Server-side-only lock value block elements.
868 	 * To serialize lvbo_init.
869 	 */
870 	struct mutex		lr_lvb_mutex;
871 	int			lr_lvb_len;
872 
873 	/** When the resource was considered as contended. */
874 	unsigned long		lr_contention_time;
875 	/** List of references to this resource. For debugging. */
876 	struct lu_ref		lr_reference;
877 
878 	struct inode		*lr_lvb_inode;
879 };
880 
ldlm_has_layout(struct ldlm_lock * lock)881 static inline bool ldlm_has_layout(struct ldlm_lock *lock)
882 {
883 	return lock->l_resource->lr_type == LDLM_IBITS &&
884 		lock->l_policy_data.l_inodebits.bits & MDS_INODELOCK_LAYOUT;
885 }
886 
887 static inline char *
ldlm_ns_name(struct ldlm_namespace * ns)888 ldlm_ns_name(struct ldlm_namespace *ns)
889 {
890 	return ns->ns_rs_hash->hs_name;
891 }
892 
893 static inline struct ldlm_namespace *
ldlm_res_to_ns(struct ldlm_resource * res)894 ldlm_res_to_ns(struct ldlm_resource *res)
895 {
896 	return res->lr_ns_bucket->nsb_namespace;
897 }
898 
899 static inline struct ldlm_namespace *
ldlm_lock_to_ns(struct ldlm_lock * lock)900 ldlm_lock_to_ns(struct ldlm_lock *lock)
901 {
902 	return ldlm_res_to_ns(lock->l_resource);
903 }
904 
905 static inline char *
ldlm_lock_to_ns_name(struct ldlm_lock * lock)906 ldlm_lock_to_ns_name(struct ldlm_lock *lock)
907 {
908 	return ldlm_ns_name(ldlm_lock_to_ns(lock));
909 }
910 
911 static inline struct adaptive_timeout *
ldlm_lock_to_ns_at(struct ldlm_lock * lock)912 ldlm_lock_to_ns_at(struct ldlm_lock *lock)
913 {
914 	return &lock->l_resource->lr_ns_bucket->nsb_at_estimate;
915 }
916 
ldlm_lvbo_init(struct ldlm_resource * res)917 static inline int ldlm_lvbo_init(struct ldlm_resource *res)
918 {
919 	struct ldlm_namespace *ns = ldlm_res_to_ns(res);
920 
921 	if (ns->ns_lvbo && ns->ns_lvbo->lvbo_init)
922 		return ns->ns_lvbo->lvbo_init(res);
923 
924 	return 0;
925 }
926 
ldlm_lvbo_size(struct ldlm_lock * lock)927 static inline int ldlm_lvbo_size(struct ldlm_lock *lock)
928 {
929 	struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
930 
931 	if (ns->ns_lvbo && ns->ns_lvbo->lvbo_size)
932 		return ns->ns_lvbo->lvbo_size(lock);
933 
934 	return 0;
935 }
936 
ldlm_lvbo_fill(struct ldlm_lock * lock,void * buf,int len)937 static inline int ldlm_lvbo_fill(struct ldlm_lock *lock, void *buf, int len)
938 {
939 	struct ldlm_namespace *ns = ldlm_lock_to_ns(lock);
940 
941 	if (ns->ns_lvbo)
942 		return ns->ns_lvbo->lvbo_fill(lock, buf, len);
943 
944 	return 0;
945 }
946 
947 struct ldlm_ast_work {
948 	struct ldlm_lock      *w_lock;
949 	int		    w_blocking;
950 	struct ldlm_lock_desc  w_desc;
951 	struct list_head	     w_list;
952 	int		    w_flags;
953 	void		  *w_data;
954 	int		    w_datalen;
955 };
956 
957 /**
958  * Common ldlm_enqueue parameters
959  */
960 struct ldlm_enqueue_info {
961 	enum ldlm_type	ei_type;  /** Type of the lock being enqueued. */
962 	enum ldlm_mode	ei_mode;  /** Mode of the lock being enqueued. */
963 	void *ei_cb_bl;  /** blocking lock callback */
964 	void *ei_cb_cp;  /** lock completion callback */
965 	void *ei_cb_gl;  /** lock glimpse callback */
966 	void *ei_cbdata; /** Data to be passed into callbacks. */
967 	unsigned int ei_enq_slave:1; /* whether enqueue slave stripes */
968 };
969 
970 extern struct obd_ops ldlm_obd_ops;
971 
972 extern char *ldlm_lockname[];
973 const char *ldlm_it2str(enum ldlm_intent_flags it);
974 
975 /**
976  * Just a fancy CDEBUG call with log level preset to LDLM_DEBUG.
977  * For the cases where we do not have actual lock to print along
978  * with a debugging message that is ldlm-related
979  */
980 #define LDLM_DEBUG_NOLOCK(format, a...)			\
981 	CDEBUG(D_DLMTRACE, "### " format "\n", ##a)
982 
983 /**
984  * Support function for lock information printing into debug logs.
985  * \see LDLM_DEBUG
986  */
987 #define ldlm_lock_debug(msgdata, mask, cdls, lock, fmt, a...) do {      \
988 	CFS_CHECK_STACK(msgdata, mask, cdls);			   \
989 									\
990 	if (((mask) & D_CANTMASK) != 0 ||			       \
991 	    ((libcfs_debug & (mask)) != 0 &&			    \
992 	     (libcfs_subsystem_debug & DEBUG_SUBSYSTEM) != 0))	  \
993 		_ldlm_lock_debug(lock, msgdata, fmt, ##a);	      \
994 } while (0)
995 
996 void _ldlm_lock_debug(struct ldlm_lock *lock,
997 		      struct libcfs_debug_msg_data *data,
998 		      const char *fmt, ...)
999 	__printf(3, 4);
1000 
1001 /**
1002  * Rate-limited version of lock printing function.
1003  */
1004 #define LDLM_DEBUG_LIMIT(mask, lock, fmt, a...) do {			 \
1005 	static struct cfs_debug_limit_state _ldlm_cdls;			   \
1006 	LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, &_ldlm_cdls);	      \
1007 	ldlm_lock_debug(&msgdata, mask, &_ldlm_cdls, lock, "### " fmt, ##a);\
1008 } while (0)
1009 
1010 #define LDLM_ERROR(lock, fmt, a...) LDLM_DEBUG_LIMIT(D_ERROR, lock, fmt, ## a)
1011 #define LDLM_WARN(lock, fmt, a...)  LDLM_DEBUG_LIMIT(D_WARNING, lock, fmt, ## a)
1012 
1013 /** Non-rate-limited lock printing function for debugging purposes. */
1014 #define LDLM_DEBUG(lock, fmt, a...)   do {				  \
1015 	if (likely(lock)) {						    \
1016 		LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, D_DLMTRACE, NULL);      \
1017 		ldlm_lock_debug(&msgdata, D_DLMTRACE, NULL, lock,	    \
1018 				"### " fmt, ##a);			    \
1019 	} else {							    \
1020 		LDLM_DEBUG_NOLOCK("no dlm lock: " fmt, ##a);		    \
1021 	}								    \
1022 } while (0)
1023 
1024 typedef int (*ldlm_processing_policy)(struct ldlm_lock *lock, __u64 *flags,
1025 				      int first_enq, enum ldlm_error *err,
1026 				      struct list_head *work_list);
1027 
1028 /**
1029  * Return values for lock iterators.
1030  * Also used during deciding of lock grants and cancellations.
1031  */
1032 #define LDLM_ITER_CONTINUE 1 /* keep iterating */
1033 #define LDLM_ITER_STOP     2 /* stop iterating */
1034 
1035 typedef int (*ldlm_iterator_t)(struct ldlm_lock *, void *);
1036 typedef int (*ldlm_res_iterator_t)(struct ldlm_resource *, void *);
1037 
1038 /** \defgroup ldlm_iterator Lock iterators
1039  *
1040  * LDLM provides for a way to iterate through every lock on a resource or
1041  * namespace or every resource in a namespace.
1042  * @{
1043  */
1044 int ldlm_resource_iterate(struct ldlm_namespace *, const struct ldlm_res_id *,
1045 			  ldlm_iterator_t iter, void *data);
1046 /** @} ldlm_iterator */
1047 
1048 int ldlm_replay_locks(struct obd_import *imp);
1049 
1050 /* ldlm_flock.c */
1051 int ldlm_flock_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data);
1052 
1053 /* ldlm_extent.c */
1054 __u64 ldlm_extent_shift_kms(struct ldlm_lock *lock, __u64 old_kms);
1055 
1056 struct ldlm_callback_suite {
1057 	ldlm_completion_callback lcs_completion;
1058 	ldlm_blocking_callback   lcs_blocking;
1059 	ldlm_glimpse_callback    lcs_glimpse;
1060 };
1061 
1062 /* ldlm_lockd.c */
1063 int ldlm_get_ref(void);
1064 void ldlm_put_ref(void);
1065 struct ldlm_lock *ldlm_request_lock(struct ptlrpc_request *req);
1066 
1067 /* ldlm_lock.c */
1068 void ldlm_lock2handle(const struct ldlm_lock *lock,
1069 		      struct lustre_handle *lockh);
1070 struct ldlm_lock *__ldlm_handle2lock(const struct lustre_handle *, __u64 flags);
1071 void ldlm_cancel_callback(struct ldlm_lock *);
1072 int ldlm_lock_remove_from_lru(struct ldlm_lock *);
1073 int ldlm_lock_set_data(const struct lustre_handle *lockh, void *data);
1074 
1075 /**
1076  * Obtain a lock reference by its handle.
1077  */
ldlm_handle2lock(const struct lustre_handle * h)1078 static inline struct ldlm_lock *ldlm_handle2lock(const struct lustre_handle *h)
1079 {
1080 	return __ldlm_handle2lock(h, 0);
1081 }
1082 
1083 #define LDLM_LOCK_REF_DEL(lock) \
1084 	lu_ref_del(&lock->l_reference, "handle", current)
1085 
1086 static inline struct ldlm_lock *
ldlm_handle2lock_long(const struct lustre_handle * h,__u64 flags)1087 ldlm_handle2lock_long(const struct lustre_handle *h, __u64 flags)
1088 {
1089 	struct ldlm_lock *lock;
1090 
1091 	lock = __ldlm_handle2lock(h, flags);
1092 	if (lock)
1093 		LDLM_LOCK_REF_DEL(lock);
1094 	return lock;
1095 }
1096 
1097 /**
1098  * Update Lock Value Block Operations (LVBO) on a resource taking into account
1099  * data from request \a r
1100  */
ldlm_res_lvbo_update(struct ldlm_resource * res,struct ptlrpc_request * r,int increase)1101 static inline int ldlm_res_lvbo_update(struct ldlm_resource *res,
1102 				       struct ptlrpc_request *r, int increase)
1103 {
1104 	if (ldlm_res_to_ns(res)->ns_lvbo &&
1105 	    ldlm_res_to_ns(res)->ns_lvbo->lvbo_update) {
1106 		return ldlm_res_to_ns(res)->ns_lvbo->lvbo_update(res, r,
1107 								 increase);
1108 	}
1109 	return 0;
1110 }
1111 
1112 int ldlm_error2errno(enum ldlm_error error);
1113 
1114 #if LUSTRE_TRACKS_LOCK_EXP_REFS
1115 void ldlm_dump_export_locks(struct obd_export *exp);
1116 #endif
1117 
1118 /**
1119  * Release a temporary lock reference obtained by ldlm_handle2lock() or
1120  * __ldlm_handle2lock().
1121  */
1122 #define LDLM_LOCK_PUT(lock)		     \
1123 do {					    \
1124 	LDLM_LOCK_REF_DEL(lock);		\
1125 	/*LDLM_DEBUG((lock), "put");*/	  \
1126 	ldlm_lock_put(lock);		    \
1127 } while (0)
1128 
1129 /**
1130  * Release a lock reference obtained by some other means (see
1131  * LDLM_LOCK_PUT()).
1132  */
1133 #define LDLM_LOCK_RELEASE(lock)		 \
1134 do {					    \
1135 	/*LDLM_DEBUG((lock), "put");*/	  \
1136 	ldlm_lock_put(lock);		    \
1137 } while (0)
1138 
1139 #define LDLM_LOCK_GET(lock)		     \
1140 ({					      \
1141 	ldlm_lock_get(lock);		    \
1142 	/*LDLM_DEBUG((lock), "get");*/	  \
1143 	lock;				   \
1144 })
1145 
1146 #define ldlm_lock_list_put(head, member, count)		     \
1147 ({								  \
1148 	struct ldlm_lock *_lock, *_next;			    \
1149 	int c = count;					      \
1150 	list_for_each_entry_safe(_lock, _next, head, member) {  \
1151 		if (c-- == 0)				       \
1152 			break;				      \
1153 		list_del_init(&_lock->member);		  \
1154 		LDLM_LOCK_RELEASE(_lock);			   \
1155 	}							   \
1156 	LASSERT(c <= 0);					    \
1157 })
1158 
1159 struct ldlm_lock *ldlm_lock_get(struct ldlm_lock *lock);
1160 void ldlm_lock_put(struct ldlm_lock *lock);
1161 void ldlm_lock2desc(struct ldlm_lock *lock, struct ldlm_lock_desc *desc);
1162 void ldlm_lock_addref(const struct lustre_handle *lockh, enum ldlm_mode mode);
1163 int  ldlm_lock_addref_try(const struct lustre_handle *lockh,
1164 			  enum ldlm_mode mode);
1165 void ldlm_lock_decref(const struct lustre_handle *lockh, enum ldlm_mode mode);
1166 void ldlm_lock_decref_and_cancel(const struct lustre_handle *lockh,
1167 				 enum ldlm_mode mode);
1168 void ldlm_lock_fail_match_locked(struct ldlm_lock *lock);
1169 void ldlm_lock_allow_match(struct ldlm_lock *lock);
1170 void ldlm_lock_allow_match_locked(struct ldlm_lock *lock);
1171 enum ldlm_mode ldlm_lock_match(struct ldlm_namespace *ns, __u64 flags,
1172 			       const struct ldlm_res_id *,
1173 			       enum ldlm_type type, union ldlm_policy_data *,
1174 			       enum ldlm_mode mode, struct lustre_handle *,
1175 			       int unref);
1176 enum ldlm_mode ldlm_revalidate_lock_handle(const struct lustre_handle *lockh,
1177 					   __u64 *bits);
1178 void ldlm_lock_cancel(struct ldlm_lock *lock);
1179 void ldlm_lock_dump_handle(int level, const struct lustre_handle *);
1180 void ldlm_unlink_lock_skiplist(struct ldlm_lock *req);
1181 
1182 /* resource.c */
1183 struct ldlm_namespace *
1184 ldlm_namespace_new(struct obd_device *obd, char *name,
1185 		   enum ldlm_side client, enum ldlm_appetite apt,
1186 		   enum ldlm_ns_type ns_type);
1187 int ldlm_namespace_cleanup(struct ldlm_namespace *ns, __u64 flags);
1188 void ldlm_namespace_free_prior(struct ldlm_namespace *ns,
1189 			       struct obd_import *imp,
1190 			       int force);
1191 void ldlm_namespace_free_post(struct ldlm_namespace *ns);
1192 void ldlm_namespace_get(struct ldlm_namespace *ns);
1193 void ldlm_namespace_put(struct ldlm_namespace *ns);
1194 int ldlm_debugfs_setup(void);
1195 void ldlm_debugfs_cleanup(void);
1196 
1197 /* resource.c - internal */
1198 struct ldlm_resource *ldlm_resource_get(struct ldlm_namespace *ns,
1199 					struct ldlm_resource *parent,
1200 					const struct ldlm_res_id *,
1201 					enum ldlm_type type, int create);
1202 int ldlm_resource_putref(struct ldlm_resource *res);
1203 void ldlm_resource_add_lock(struct ldlm_resource *res,
1204 			    struct list_head *head,
1205 			    struct ldlm_lock *lock);
1206 void ldlm_resource_unlink_lock(struct ldlm_lock *lock);
1207 void ldlm_res2desc(struct ldlm_resource *res, struct ldlm_resource_desc *desc);
1208 void ldlm_dump_all_namespaces(enum ldlm_side client, int level);
1209 void ldlm_namespace_dump(int level, struct ldlm_namespace *);
1210 void ldlm_resource_dump(int level, struct ldlm_resource *);
1211 int ldlm_lock_change_resource(struct ldlm_namespace *, struct ldlm_lock *,
1212 			      const struct ldlm_res_id *);
1213 
1214 #define LDLM_RESOURCE_ADDREF(res) do {				  \
1215 	lu_ref_add_atomic(&(res)->lr_reference, __func__, current);  \
1216 } while (0)
1217 
1218 #define LDLM_RESOURCE_DELREF(res) do {				  \
1219 	lu_ref_del(&(res)->lr_reference, __func__, current);	  \
1220 } while (0)
1221 
1222 /* ldlm_request.c */
1223 /** \defgroup ldlm_local_ast Default AST handlers for local locks
1224  * These AST handlers are typically used for server-side local locks and are
1225  * also used by client-side lock handlers to perform minimum level base
1226  * processing.
1227  * @{
1228  */
1229 int ldlm_completion_ast_async(struct ldlm_lock *lock, __u64 flags, void *data);
1230 int ldlm_completion_ast(struct ldlm_lock *lock, __u64 flags, void *data);
1231 /** @} ldlm_local_ast */
1232 
1233 /** \defgroup ldlm_cli_api API to operate on locks from actual LDLM users.
1234  * These are typically used by client and server (*_local versions)
1235  * to obtain and release locks.
1236  * @{
1237  */
1238 int ldlm_cli_enqueue(struct obd_export *exp, struct ptlrpc_request **reqp,
1239 		     struct ldlm_enqueue_info *einfo,
1240 		     const struct ldlm_res_id *res_id,
1241 		     union ldlm_policy_data const *policy, __u64 *flags,
1242 		     void *lvb, __u32 lvb_len, enum lvb_type lvb_type,
1243 		     struct lustre_handle *lockh, int async);
1244 int ldlm_prep_enqueue_req(struct obd_export *exp,
1245 			  struct ptlrpc_request *req,
1246 			  struct list_head *cancels,
1247 			  int count);
1248 int ldlm_prep_elc_req(struct obd_export *exp,
1249 		      struct ptlrpc_request *req,
1250 		      int version, int opc, int canceloff,
1251 		      struct list_head *cancels, int count);
1252 
1253 int ldlm_cli_enqueue_fini(struct obd_export *exp, struct ptlrpc_request *req,
1254 			  enum ldlm_type type, __u8 with_policy,
1255 			  enum ldlm_mode mode,
1256 			  __u64 *flags, void *lvb, __u32 lvb_len,
1257 			  const struct lustre_handle *lockh, int rc);
1258 int ldlm_cli_update_pool(struct ptlrpc_request *req);
1259 int ldlm_cli_cancel(const struct lustre_handle *lockh,
1260 		    enum ldlm_cancel_flags cancel_flags);
1261 int ldlm_cli_cancel_unused(struct ldlm_namespace *, const struct ldlm_res_id *,
1262 			   enum ldlm_cancel_flags flags, void *opaque);
1263 int ldlm_cli_cancel_unused_resource(struct ldlm_namespace *ns,
1264 				    const struct ldlm_res_id *res_id,
1265 				    union ldlm_policy_data *policy,
1266 				    enum ldlm_mode mode,
1267 				    enum ldlm_cancel_flags flags,
1268 				    void *opaque);
1269 int ldlm_cancel_resource_local(struct ldlm_resource *res,
1270 			       struct list_head *cancels,
1271 			       union ldlm_policy_data *policy,
1272 			       enum ldlm_mode mode, __u64 lock_flags,
1273 			       enum ldlm_cancel_flags cancel_flags,
1274 			       void *opaque);
1275 int ldlm_cli_cancel_list_local(struct list_head *cancels, int count,
1276 			       enum ldlm_cancel_flags flags);
1277 int ldlm_cli_cancel_list(struct list_head *head, int count,
1278 			 struct ptlrpc_request *req,
1279 			 enum ldlm_cancel_flags flags);
1280 /** @} ldlm_cli_api */
1281 
1282 /* mds/handler.c */
1283 /* This has to be here because recursive inclusion sucks. */
1284 int intent_disposition(struct ldlm_reply *rep, int flag);
1285 void intent_set_disposition(struct ldlm_reply *rep, int flag);
1286 
1287 /**
1288  * "Modes" of acquiring lock_res, necessary to tell lockdep that taking more
1289  * than one lock_res is dead-lock safe.
1290  */
1291 enum lock_res_type {
1292 	LRT_NORMAL,
1293 	LRT_NEW
1294 };
1295 
1296 /** Lock resource. */
lock_res(struct ldlm_resource * res)1297 static inline void lock_res(struct ldlm_resource *res)
1298 {
1299 	spin_lock(&res->lr_lock);
1300 }
1301 
1302 /** Lock resource with a way to instruct lockdep code about nestedness-safe. */
lock_res_nested(struct ldlm_resource * res,enum lock_res_type mode)1303 static inline void lock_res_nested(struct ldlm_resource *res,
1304 				   enum lock_res_type mode)
1305 {
1306 	spin_lock_nested(&res->lr_lock, mode);
1307 }
1308 
1309 /** Unlock resource. */
unlock_res(struct ldlm_resource * res)1310 static inline void unlock_res(struct ldlm_resource *res)
1311 {
1312 	spin_unlock(&res->lr_lock);
1313 }
1314 
1315 /** Check if resource is already locked, assert if not. */
check_res_locked(struct ldlm_resource * res)1316 static inline void check_res_locked(struct ldlm_resource *res)
1317 {
1318 	assert_spin_locked(&res->lr_lock);
1319 }
1320 
1321 struct ldlm_resource *lock_res_and_lock(struct ldlm_lock *lock);
1322 void unlock_res_and_lock(struct ldlm_lock *lock);
1323 
1324 /* ldlm_pool.c */
1325 /** \defgroup ldlm_pools Various LDLM pool related functions
1326  * There are not used outside of ldlm.
1327  * @{
1328  */
1329 int ldlm_pools_init(void);
1330 void ldlm_pools_fini(void);
1331 
1332 int ldlm_pool_init(struct ldlm_pool *pl, struct ldlm_namespace *ns,
1333 		   int idx, enum ldlm_side client);
1334 void ldlm_pool_fini(struct ldlm_pool *pl);
1335 void ldlm_pool_add(struct ldlm_pool *pl, struct ldlm_lock *lock);
1336 void ldlm_pool_del(struct ldlm_pool *pl, struct ldlm_lock *lock);
1337 /** @} */
1338 
ldlm_extent_overlap(const struct ldlm_extent * ex1,const struct ldlm_extent * ex2)1339 static inline int ldlm_extent_overlap(const struct ldlm_extent *ex1,
1340 				      const struct ldlm_extent *ex2)
1341 {
1342 	return ex1->start <= ex2->end && ex2->start <= ex1->end;
1343 }
1344 
1345 /* check if @ex1 contains @ex2 */
ldlm_extent_contain(const struct ldlm_extent * ex1,const struct ldlm_extent * ex2)1346 static inline int ldlm_extent_contain(const struct ldlm_extent *ex1,
1347 				      const struct ldlm_extent *ex2)
1348 {
1349 	return ex1->start <= ex2->start && ex1->end >= ex2->end;
1350 }
1351 
1352 #endif
1353 /** @} LDLM */
1354