4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
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.
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).
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
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
27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
28 * Use is subject to license terms.
30 * Copyright (c) 2011, 2013, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
37 #ifndef __LUSTRE_LU_OBJECT_H
38 #define __LUSTRE_LU_OBJECT_H
41 #include <libcfs/libcfs.h>
42 #include <lustre/lustre_idl.h>
46 struct proc_dir_entry;
51 * lu_* data-types represent server-side entities shared by data and meta-data
56 * -# support for layering.
58 * Server side object is split into layers, one per device in the
59 * corresponding device stack. Individual layer is represented by struct
60 * lu_object. Compound layered object --- by struct lu_object_header. Most
61 * interface functions take lu_object as an argument and operate on the
62 * whole compound object. This decision was made due to the following
65 * - it's envisaged that lu_object will be used much more often than
68 * - we want lower (non-top) layers to be able to initiate operations
69 * on the whole object.
71 * Generic code supports layering more complex than simple stacking, e.g.,
72 * it is possible that at some layer object "spawns" multiple sub-objects
75 * -# fid-based identification.
77 * Compound object is uniquely identified by its fid. Objects are indexed
78 * by their fids (hash table is used for index).
80 * -# caching and life-cycle management.
82 * Object's life-time is controlled by reference counting. When reference
83 * count drops to 0, object is returned to cache. Cached objects still
84 * retain their identity (i.e., fid), and can be recovered from cache.
86 * Objects are kept in the global LRU list, and lu_site_purge() function
87 * can be used to reclaim given number of unused objects from the tail of
90 * -# avoiding recursion.
92 * Generic code tries to replace recursion through layers by iterations
93 * where possible. Additionally to the end of reducing stack consumption,
94 * data, when practically possible, are allocated through lu_context_key
95 * interface rather than on stack.
102 struct lu_object_header;
107 * Operations common for data and meta-data devices.
109 struct lu_device_operations {
111 * Allocate object for the given device (without lower-layer
112 * parts). This is called by lu_object_operations::loo_object_init()
113 * from the parent layer, and should setup at least lu_object::lo_dev
114 * and lu_object::lo_ops fields of resulting lu_object.
116 * Object creation protocol.
118 * Due to design goal of avoiding recursion, object creation (see
119 * lu_object_alloc()) is somewhat involved:
121 * - first, lu_device_operations::ldo_object_alloc() method of the
122 * top-level device in the stack is called. It should allocate top
123 * level object (including lu_object_header), but without any
124 * lower-layer sub-object(s).
126 * - then lu_object_alloc() sets fid in the header of newly created
129 * - then lu_object_operations::loo_object_init() is called. It has
130 * to allocate lower-layer object(s). To do this,
131 * lu_object_operations::loo_object_init() calls ldo_object_alloc()
132 * of the lower-layer device(s).
134 * - for all new objects allocated by
135 * lu_object_operations::loo_object_init() (and inserted into object
136 * stack), lu_object_operations::loo_object_init() is called again
137 * repeatedly, until no new objects are created.
139 * \post ergo(!IS_ERR(result), result->lo_dev == d &&
140 * result->lo_ops != NULL);
142 struct lu_object *(*ldo_object_alloc)(const struct lu_env *env,
143 const struct lu_object_header *h,
144 struct lu_device *d);
146 * process config specific for device.
148 int (*ldo_process_config)(const struct lu_env *env,
149 struct lu_device *, struct lustre_cfg *);
150 int (*ldo_recovery_complete)(const struct lu_env *,
154 * initialize local objects for device. this method called after layer has
155 * been initialized (after LCFG_SETUP stage) and before it starts serving
159 int (*ldo_prepare)(const struct lu_env *,
160 struct lu_device *parent,
161 struct lu_device *dev);
166 * For lu_object_conf flags
169 /* This is a new object to be allocated, or the file
170 * corresponding to the object does not exists. */
171 LOC_F_NEW = 0x00000001,
175 * Object configuration, describing particulars of object being created. On
176 * server this is not used, as server objects are full identified by fid. On
177 * client configuration contains struct lustre_md.
179 struct lu_object_conf {
181 * Some hints for obj find and alloc.
183 loc_flags_t loc_flags;
187 * Type of "printer" function used by lu_object_operations::loo_object_print()
190 * Printer function is needed to provide some flexibility in (semi-)debugging
191 * output: possible implementations: printk, CDEBUG, sysfs/seq_file
193 typedef int (*lu_printer_t)(const struct lu_env *env,
194 void *cookie, const char *format, ...)
195 __attribute__ ((format (printf, 3, 4)));
198 * Operations specific for particular lu_object.
200 struct lu_object_operations {
203 * Allocate lower-layer parts of the object by calling
204 * lu_device_operations::ldo_object_alloc() of the corresponding
207 * This method is called once for each object inserted into object
208 * stack. It's responsibility of this method to insert lower-layer
209 * object(s) it create into appropriate places of object stack.
211 int (*loo_object_init)(const struct lu_env *env,
213 const struct lu_object_conf *conf);
215 * Called (in top-to-bottom order) during object allocation after all
216 * layers were allocated and initialized. Can be used to perform
217 * initialization depending on lower layers.
219 int (*loo_object_start)(const struct lu_env *env,
220 struct lu_object *o);
222 * Called before lu_object_operations::loo_object_free() to signal
223 * that object is being destroyed. Dual to
224 * lu_object_operations::loo_object_init().
226 void (*loo_object_delete)(const struct lu_env *env,
227 struct lu_object *o);
229 * Dual to lu_device_operations::ldo_object_alloc(). Called when
230 * object is removed from memory.
232 void (*loo_object_free)(const struct lu_env *env,
233 struct lu_object *o);
235 * Called when last active reference to the object is released (and
236 * object returns to the cache). This method is optional.
238 void (*loo_object_release)(const struct lu_env *env,
239 struct lu_object *o);
241 * Optional debugging helper. Print given object.
243 int (*loo_object_print)(const struct lu_env *env, void *cookie,
244 lu_printer_t p, const struct lu_object *o);
246 * Optional debugging method. Returns true iff method is internally
249 int (*loo_object_invariant)(const struct lu_object *o);
255 struct lu_device_type;
258 * Device: a layer in the server side abstraction stacking.
262 * reference count. This is incremented, in particular, on each object
263 * created at this layer.
265 * \todo XXX which means that atomic_t is probably too small.
269 * Pointer to device type. Never modified once set.
271 struct lu_device_type *ld_type;
273 * Operation vector for this device.
275 const struct lu_device_operations *ld_ops;
277 * Stack this device belongs to.
279 struct lu_site *ld_site;
280 struct proc_dir_entry *ld_proc_entry;
282 /** \todo XXX: temporary back pointer into obd. */
283 struct obd_device *ld_obd;
285 * A list of references to this object, for debugging.
287 struct lu_ref ld_reference;
289 * Link the device to the site.
291 cfs_list_t ld_linkage;
294 struct lu_device_type_operations;
297 * Tag bits for device type. They are used to distinguish certain groups of
301 /** this is meta-data device */
302 LU_DEVICE_MD = (1 << 0),
303 /** this is data device */
304 LU_DEVICE_DT = (1 << 1),
305 /** data device in the client stack */
306 LU_DEVICE_CL = (1 << 2)
312 struct lu_device_type {
314 * Tag bits. Taken from enum lu_device_tag. Never modified once set.
318 * Name of this class. Unique system-wide. Never modified once set.
322 * Operations for this type.
324 const struct lu_device_type_operations *ldt_ops;
326 * \todo XXX: temporary pointer to associated obd_type.
328 struct obd_type *ldt_obd_type;
330 * \todo XXX: temporary: context tags used by obd_*() calls.
334 * Number of existing device type instances.
336 unsigned ldt_device_nr;
338 * Linkage into a global list of all device types.
340 * \see lu_device_types.
342 cfs_list_t ldt_linkage;
346 * Operations on a device type.
348 struct lu_device_type_operations {
350 * Allocate new device.
352 struct lu_device *(*ldto_device_alloc)(const struct lu_env *env,
353 struct lu_device_type *t,
354 struct lustre_cfg *lcfg);
356 * Free device. Dual to
357 * lu_device_type_operations::ldto_device_alloc(). Returns pointer to
358 * the next device in the stack.
360 struct lu_device *(*ldto_device_free)(const struct lu_env *,
364 * Initialize the devices after allocation
366 int (*ldto_device_init)(const struct lu_env *env,
367 struct lu_device *, const char *,
370 * Finalize device. Dual to
371 * lu_device_type_operations::ldto_device_init(). Returns pointer to
372 * the next device in the stack.
374 struct lu_device *(*ldto_device_fini)(const struct lu_env *env,
377 * Initialize device type. This is called on module load.
379 int (*ldto_init)(struct lu_device_type *t);
381 * Finalize device type. Dual to
382 * lu_device_type_operations::ldto_init(). Called on module unload.
384 void (*ldto_fini)(struct lu_device_type *t);
386 * Called when the first device is created.
388 void (*ldto_start)(struct lu_device_type *t);
390 * Called when number of devices drops to 0.
392 void (*ldto_stop)(struct lu_device_type *t);
395 static inline int lu_device_is_md(const struct lu_device *d)
397 return ergo(d != NULL, d->ld_type->ldt_tags & LU_DEVICE_MD);
401 * Flags for the object layers.
403 enum lu_object_flags {
405 * this flags is set if lu_object_operations::loo_object_init() has
406 * been called for this layer. Used by lu_object_alloc().
408 LU_OBJECT_ALLOCATED = (1 << 0)
412 * Common object attributes.
417 /** modification time in seconds since Epoch */
419 /** access time in seconds since Epoch */
421 /** change time in seconds since Epoch */
423 /** 512-byte blocks allocated to object */
425 /** permission bits and file type */
433 /** number of persistent references to this object */
435 /** blk bits of the object*/
437 /** blk size of the object*/
449 /** Bit-mask of valid attributes */
463 LA_BLKSIZE = 1 << 12,
464 LA_KILL_SUID = 1 << 13,
465 LA_KILL_SGID = 1 << 14,
469 * Layer in the layered object.
473 * Header for this object.
475 struct lu_object_header *lo_header;
477 * Device for this layer.
479 struct lu_device *lo_dev;
481 * Operations for this object.
483 const struct lu_object_operations *lo_ops;
485 * Linkage into list of all layers.
487 cfs_list_t lo_linkage;
489 * Depth. Top level layer depth is 0.
493 * Flags from enum lu_object_flags.
497 * Link to the device, for debugging.
499 struct lu_ref_link *lo_dev_ref;
502 enum lu_object_header_flags {
504 * Don't keep this object in cache. Object will be destroyed as soon
505 * as last reference to it is released. This flag cannot be cleared
508 LU_OBJECT_HEARD_BANSHEE = 0,
510 * Mark this object has already been taken out of cache.
512 LU_OBJECT_UNHASHED = 1
515 enum lu_object_header_attr {
516 LOHA_EXISTS = 1 << 0,
517 LOHA_REMOTE = 1 << 1,
519 * UNIX file type is stored in S_IFMT bits.
521 LOHA_FT_START = 001 << 12, /**< S_IFIFO */
522 LOHA_FT_END = 017 << 12, /**< S_IFMT */
526 * "Compound" object, consisting of multiple layers.
528 * Compound object with given fid is unique with given lu_site.
530 * Note, that object does *not* necessary correspond to the real object in the
531 * persistent storage: object is an anchor for locking and method calling, so
532 * it is created for things like not-yet-existing child created by mkdir or
533 * create calls. lu_object_operations::loo_exists() can be used to check
534 * whether object is backed by persistent storage entity.
536 struct lu_object_header {
538 * Object flags from enum lu_object_header_flags. Set and checked
541 unsigned long loh_flags;
543 * Object reference count. Protected by lu_site::ls_guard.
545 cfs_atomic_t loh_ref;
547 * Fid, uniquely identifying this object.
549 struct lu_fid loh_fid;
551 * Common object attributes, cached for efficiency. From enum
552 * lu_object_header_attr.
556 * Linkage into per-site hash table. Protected by lu_site::ls_guard.
558 cfs_hlist_node_t loh_hash;
560 * Linkage into per-site LRU list. Protected by lu_site::ls_guard.
564 * Linkage into list of layers. Never modified once set (except lately
565 * during object destruction). No locking is necessary.
567 cfs_list_t loh_layers;
569 * A list of references to this object, for debugging.
571 struct lu_ref loh_reference;
576 struct lu_site_bkt_data {
578 * number of busy object on this bucket
582 * LRU list, updated on each access to object. Protected by
583 * bucket lock of lu_site::ls_obj_hash.
585 * "Cold" end of LRU is lu_site::ls_lru.next. Accessed object are
586 * moved to the lu_site::ls_lru.prev (this is due to the non-existence
587 * of list_for_each_entry_safe_reverse()).
591 * Wait-queue signaled when an object in this site is ultimately
592 * destroyed (lu_object_free()). It is used by lu_object_find() to
593 * wait before re-trying when object in the process of destruction is
594 * found in the hash table.
596 * \see htable_lookup().
598 cfs_waitq_t lsb_marche_funebre;
606 LU_SS_CACHE_DEATH_RACE,
612 * lu_site is a "compartment" within which objects are unique, and LRU
613 * discipline is maintained.
615 * lu_site exists so that multiple layered stacks can co-exist in the same
618 * lu_site has the same relation to lu_device as lu_object_header to
625 cfs_hash_t *ls_obj_hash;
627 * index of bucket on hash table while purging
631 * Top-level device for this stack.
633 struct lu_device *ls_top_dev;
635 * Bottom-level device for this stack
637 struct lu_device *ls_bottom_dev;
639 * Linkage into global list of sites.
641 cfs_list_t ls_linkage;
643 * List for lu device for this site, protected
646 cfs_list_t ls_ld_linkage;
647 spinlock_t ls_ld_lock;
652 struct lprocfs_stats *ls_stats;
654 * XXX: a hack! fld has to find md_site via site, remove when possible
656 struct seq_server_site *ld_seq_site;
659 static inline struct lu_site_bkt_data *
660 lu_site_bkt_from_fid(struct lu_site *site, struct lu_fid *fid)
664 cfs_hash_bd_get(site->ls_obj_hash, fid, &bd);
665 return cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
669 * Constructors/destructors.
673 int lu_site_init (struct lu_site *s, struct lu_device *d);
674 void lu_site_fini (struct lu_site *s);
675 int lu_site_init_finish (struct lu_site *s);
676 void lu_stack_fini (const struct lu_env *env, struct lu_device *top);
677 void lu_device_get (struct lu_device *d);
678 void lu_device_put (struct lu_device *d);
679 int lu_device_init (struct lu_device *d, struct lu_device_type *t);
680 void lu_device_fini (struct lu_device *d);
681 int lu_object_header_init(struct lu_object_header *h);
682 void lu_object_header_fini(struct lu_object_header *h);
683 int lu_object_init (struct lu_object *o,
684 struct lu_object_header *h, struct lu_device *d);
685 void lu_object_fini (struct lu_object *o);
686 void lu_object_add_top (struct lu_object_header *h, struct lu_object *o);
687 void lu_object_add (struct lu_object *before, struct lu_object *o);
689 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d);
690 void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d);
693 * Helpers to initialize and finalize device types.
696 int lu_device_type_init(struct lu_device_type *ldt);
697 void lu_device_type_fini(struct lu_device_type *ldt);
698 void lu_types_stop(void);
703 * Caching and reference counting.
708 * Acquire additional reference to the given object. This function is used to
709 * attain additional reference. To acquire initial reference use
712 static inline void lu_object_get(struct lu_object *o)
714 LASSERT(cfs_atomic_read(&o->lo_header->loh_ref) > 0);
715 cfs_atomic_inc(&o->lo_header->loh_ref);
719 * Return true of object will not be cached after last reference to it is
722 static inline int lu_object_is_dying(const struct lu_object_header *h)
724 return test_bit(LU_OBJECT_HEARD_BANSHEE, &h->loh_flags);
727 void lu_object_put(const struct lu_env *env, struct lu_object *o);
728 void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o);
729 void lu_object_unhash(const struct lu_env *env, struct lu_object *o);
731 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr);
733 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
734 lu_printer_t printer);
735 struct lu_object *lu_object_find(const struct lu_env *env,
736 struct lu_device *dev, const struct lu_fid *f,
737 const struct lu_object_conf *conf);
738 struct lu_object *lu_object_find_at(const struct lu_env *env,
739 struct lu_device *dev,
740 const struct lu_fid *f,
741 const struct lu_object_conf *conf);
742 struct lu_object *lu_object_find_slice(const struct lu_env *env,
743 struct lu_device *dev,
744 const struct lu_fid *f,
745 const struct lu_object_conf *conf);
754 * First (topmost) sub-object of given compound object
756 static inline struct lu_object *lu_object_top(struct lu_object_header *h)
758 LASSERT(!cfs_list_empty(&h->loh_layers));
759 return container_of0(h->loh_layers.next, struct lu_object, lo_linkage);
763 * Next sub-object in the layering
765 static inline struct lu_object *lu_object_next(const struct lu_object *o)
767 return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage);
771 * Pointer to the fid of this object.
773 static inline const struct lu_fid *lu_object_fid(const struct lu_object *o)
775 return &o->lo_header->loh_fid;
779 * return device operations vector for this object
781 static const inline struct lu_device_operations *
782 lu_object_ops(const struct lu_object *o)
784 return o->lo_dev->ld_ops;
788 * Given a compound object, find its slice, corresponding to the device type
791 struct lu_object *lu_object_locate(struct lu_object_header *h,
792 const struct lu_device_type *dtype);
795 * Printer function emitting messages through libcfs_debug_msg().
797 int lu_cdebug_printer(const struct lu_env *env,
798 void *cookie, const char *format, ...);
801 * Print object description followed by a user-supplied message.
803 #define LU_OBJECT_DEBUG(mask, env, object, format, ...) \
805 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \
807 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \
808 lu_object_print(env, &msgdata, lu_cdebug_printer, object);\
809 CDEBUG(mask, format , ## __VA_ARGS__); \
814 * Print short object description followed by a user-supplied message.
816 #define LU_OBJECT_HEADER(mask, env, object, format, ...) \
818 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \
820 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \
821 lu_object_header_print(env, &msgdata, lu_cdebug_printer,\
822 (object)->lo_header); \
823 lu_cdebug_printer(env, &msgdata, "\n"); \
824 CDEBUG(mask, format , ## __VA_ARGS__); \
828 void lu_object_print (const struct lu_env *env, void *cookie,
829 lu_printer_t printer, const struct lu_object *o);
830 void lu_object_header_print(const struct lu_env *env, void *cookie,
831 lu_printer_t printer,
832 const struct lu_object_header *hdr);
835 * Check object consistency.
837 int lu_object_invariant(const struct lu_object *o);
841 * Check whether object exists, no matter on local or remote storage.
842 * Note: LOHA_EXISTS will be set once some one created the object,
843 * and it does not needs to be committed to storage.
845 #define lu_object_exists(o) ((o)->lo_header->loh_attr & LOHA_EXISTS)
848 * Check whether object on the remote storage.
850 #define lu_object_remote(o) unlikely((o)->lo_header->loh_attr & LOHA_REMOTE)
852 static inline int lu_object_assert_exists(const struct lu_object *o)
854 return lu_object_exists(o);
857 static inline int lu_object_assert_not_exists(const struct lu_object *o)
859 return !lu_object_exists(o);
863 * Attr of this object.
865 static inline __u32 lu_object_attr(const struct lu_object *o)
867 LASSERT(lu_object_exists(o) != 0);
868 return o->lo_header->loh_attr;
871 static inline struct lu_ref_link *lu_object_ref_add(struct lu_object *o,
875 return lu_ref_add(&o->lo_header->loh_reference, scope, source);
878 static inline void lu_object_ref_del(struct lu_object *o,
879 const char *scope, const void *source)
881 lu_ref_del(&o->lo_header->loh_reference, scope, source);
884 static inline void lu_object_ref_del_at(struct lu_object *o,
885 struct lu_ref_link *link,
886 const char *scope, const void *source)
888 lu_ref_del_at(&o->lo_header->loh_reference, link, scope, source);
891 /** input params, should be filled out by mdt */
895 /** count in bytes */
896 unsigned int rp_count;
897 /** number of pages */
898 unsigned int rp_npages;
899 /** requested attr */
901 /** pointers to pages */
902 struct page **rp_pages;
905 enum lu_xattr_flags {
906 LU_XATTR_REPLACE = (1 << 0),
907 LU_XATTR_CREATE = (1 << 1)
915 /** For lu_context health-checks */
916 enum lu_context_state {
924 * lu_context. Execution context for lu_object methods. Currently associated
927 * All lu_object methods, except device and device type methods (called during
928 * system initialization and shutdown) are executed "within" some
929 * lu_context. This means, that pointer to some "current" lu_context is passed
930 * as an argument to all methods.
932 * All service ptlrpc threads create lu_context as part of their
933 * initialization. It is possible to create "stand-alone" context for other
934 * execution environments (like system calls).
936 * lu_object methods mainly use lu_context through lu_context_key interface
937 * that allows each layer to associate arbitrary pieces of data with each
938 * context (see pthread_key_create(3) for similar interface).
940 * On a client, lu_context is bound to a thread, see cl_env_get().
942 * \see lu_context_key
946 * lu_context is used on the client side too. Yet we don't want to
947 * allocate values of server-side keys for the client contexts and
950 * To achieve this, set of tags in introduced. Contexts and keys are
951 * marked with tags. Key value are created only for context whose set
952 * of tags has non-empty intersection with one for key. Tags are taken
953 * from enum lu_context_tag.
956 enum lu_context_state lc_state;
958 * Pointer to the home service thread. NULL for other execution
961 struct ptlrpc_thread *lc_thread;
963 * Pointer to an array with key values. Internal implementation
968 * Linkage into a list of all remembered contexts. Only
969 * `non-transient' contexts, i.e., ones created for service threads
972 cfs_list_t lc_remember;
974 * Version counter used to skip calls to lu_context_refill() when no
975 * keys were registered.
985 * lu_context_key interface. Similar to pthread_key.
988 enum lu_context_tag {
990 * Thread on md server
992 LCT_MD_THREAD = 1 << 0,
994 * Thread on dt server
996 LCT_DT_THREAD = 1 << 1,
998 * Context for transaction handle
1000 LCT_TX_HANDLE = 1 << 2,
1004 LCT_CL_THREAD = 1 << 3,
1006 * A per-request session on a server, and a per-system-call session on
1009 LCT_SESSION = 1 << 4,
1011 * A per-request data on OSP device
1013 LCT_OSP_THREAD = 1 << 5,
1017 LCT_MG_THREAD = 1 << 6,
1019 * Context for local operations
1023 * Set when at least one of keys, having values in this context has
1024 * non-NULL lu_context_key::lct_exit() method. This is used to
1025 * optimize lu_context_exit() call.
1027 LCT_HAS_EXIT = 1 << 28,
1029 * Don't add references for modules creating key values in that context.
1030 * This is only for contexts used internally by lu_object framework.
1032 LCT_NOREF = 1 << 29,
1034 * Key is being prepared for retiring, don't create new values for it.
1036 LCT_QUIESCENT = 1 << 30,
1038 * Context should be remembered.
1040 LCT_REMEMBER = 1 << 31,
1042 * Contexts usable in cache shrinker thread.
1044 LCT_SHRINKER = LCT_MD_THREAD|LCT_DT_THREAD|LCT_CL_THREAD|LCT_NOREF
1048 * Key. Represents per-context value slot.
1050 * Keys are usually registered when module owning the key is initialized, and
1051 * de-registered when module is unloaded. Once key is registered, all new
1052 * contexts with matching tags, will get key value. "Old" contexts, already
1053 * initialized at the time of key registration, can be forced to get key value
1054 * by calling lu_context_refill().
1056 * Every key value is counted in lu_context_key::lct_used and acquires a
1057 * reference on an owning module. This means, that all key values have to be
1058 * destroyed before module can be unloaded. This is usually achieved by
1059 * stopping threads started by the module, that created contexts in their
1060 * entry functions. Situation is complicated by the threads shared by multiple
1061 * modules, like ptlrpcd daemon on a client. To work around this problem,
1062 * contexts, created in such threads, are `remembered' (see
1063 * LCT_REMEMBER)---i.e., added into a global list. When module is preparing
1064 * for unloading it does the following:
1066 * - marks its keys as `quiescent' (lu_context_tag::LCT_QUIESCENT)
1067 * preventing new key values from being allocated in the new contexts,
1070 * - scans a list of remembered contexts, destroying values of module
1071 * keys, thus releasing references to the module.
1073 * This is done by lu_context_key_quiesce(). If module is re-activated
1074 * before key has been de-registered, lu_context_key_revive() call clears
1075 * `quiescent' marker.
1077 * lu_context code doesn't provide any internal synchronization for these
1078 * activities---it's assumed that startup (including threads start-up) and
1079 * shutdown are serialized by some external means.
1083 struct lu_context_key {
1085 * Set of tags for which values of this key are to be instantiated.
1089 * Value constructor. This is called when new value is created for a
1090 * context. Returns pointer to new value of error pointer.
1092 void *(*lct_init)(const struct lu_context *ctx,
1093 struct lu_context_key *key);
1095 * Value destructor. Called when context with previously allocated
1096 * value of this slot is destroyed. \a data is a value that was returned
1097 * by a matching call to lu_context_key::lct_init().
1099 void (*lct_fini)(const struct lu_context *ctx,
1100 struct lu_context_key *key, void *data);
1102 * Optional method called on lu_context_exit() for all allocated
1103 * keys. Can be used by debugging code checking that locks are
1106 void (*lct_exit)(const struct lu_context *ctx,
1107 struct lu_context_key *key, void *data);
1109 * Internal implementation detail: index within lu_context::lc_value[]
1110 * reserved for this key.
1114 * Internal implementation detail: number of values created for this
1117 cfs_atomic_t lct_used;
1119 * Internal implementation detail: module for this key.
1121 cfs_module_t *lct_owner;
1123 * References to this key. For debugging.
1125 struct lu_ref lct_reference;
1128 #define LU_KEY_INIT(mod, type) \
1129 static void* mod##_key_init(const struct lu_context *ctx, \
1130 struct lu_context_key *key) \
1134 CLASSERT(CFS_PAGE_SIZE >= sizeof (*value)); \
1136 OBD_ALLOC_PTR(value); \
1137 if (value == NULL) \
1138 value = ERR_PTR(-ENOMEM); \
1142 struct __##mod##__dummy_init {;} /* semicolon catcher */
1144 #define LU_KEY_FINI(mod, type) \
1145 static void mod##_key_fini(const struct lu_context *ctx, \
1146 struct lu_context_key *key, void* data) \
1148 type *info = data; \
1150 OBD_FREE_PTR(info); \
1152 struct __##mod##__dummy_fini {;} /* semicolon catcher */
1154 #define LU_KEY_INIT_FINI(mod, type) \
1155 LU_KEY_INIT(mod,type); \
1156 LU_KEY_FINI(mod,type)
1158 #define LU_CONTEXT_KEY_DEFINE(mod, tags) \
1159 struct lu_context_key mod##_thread_key = { \
1161 .lct_init = mod##_key_init, \
1162 .lct_fini = mod##_key_fini \
1165 #define LU_CONTEXT_KEY_INIT(key) \
1167 (key)->lct_owner = THIS_MODULE; \
1170 int lu_context_key_register(struct lu_context_key *key);
1171 void lu_context_key_degister(struct lu_context_key *key);
1172 void *lu_context_key_get (const struct lu_context *ctx,
1173 const struct lu_context_key *key);
1174 void lu_context_key_quiesce (struct lu_context_key *key);
1175 void lu_context_key_revive (struct lu_context_key *key);
1179 * LU_KEY_INIT_GENERIC() has to be a macro to correctly determine an
1183 #define LU_KEY_INIT_GENERIC(mod) \
1184 static void mod##_key_init_generic(struct lu_context_key *k, ...) \
1186 struct lu_context_key *key = k; \
1189 va_start(args, k); \
1191 LU_CONTEXT_KEY_INIT(key); \
1192 key = va_arg(args, struct lu_context_key *); \
1193 } while (key != NULL); \
1197 #define LU_TYPE_INIT(mod, ...) \
1198 LU_KEY_INIT_GENERIC(mod) \
1199 static int mod##_type_init(struct lu_device_type *t) \
1201 mod##_key_init_generic(__VA_ARGS__, NULL); \
1202 return lu_context_key_register_many(__VA_ARGS__, NULL); \
1204 struct __##mod##_dummy_type_init {;}
1206 #define LU_TYPE_FINI(mod, ...) \
1207 static void mod##_type_fini(struct lu_device_type *t) \
1209 lu_context_key_degister_many(__VA_ARGS__, NULL); \
1211 struct __##mod##_dummy_type_fini {;}
1213 #define LU_TYPE_START(mod, ...) \
1214 static void mod##_type_start(struct lu_device_type *t) \
1216 lu_context_key_revive_many(__VA_ARGS__, NULL); \
1218 struct __##mod##_dummy_type_start {;}
1220 #define LU_TYPE_STOP(mod, ...) \
1221 static void mod##_type_stop(struct lu_device_type *t) \
1223 lu_context_key_quiesce_many(__VA_ARGS__, NULL); \
1225 struct __##mod##_dummy_type_stop {;}
1229 #define LU_TYPE_INIT_FINI(mod, ...) \
1230 LU_TYPE_INIT(mod, __VA_ARGS__); \
1231 LU_TYPE_FINI(mod, __VA_ARGS__); \
1232 LU_TYPE_START(mod, __VA_ARGS__); \
1233 LU_TYPE_STOP(mod, __VA_ARGS__)
1235 int lu_context_init (struct lu_context *ctx, __u32 tags);
1236 void lu_context_fini (struct lu_context *ctx);
1237 void lu_context_enter (struct lu_context *ctx);
1238 void lu_context_exit (struct lu_context *ctx);
1239 int lu_context_refill(struct lu_context *ctx);
1242 * Helper functions to operate on multiple keys. These are used by the default
1243 * device type operations, defined by LU_TYPE_INIT_FINI().
1246 int lu_context_key_register_many(struct lu_context_key *k, ...);
1247 void lu_context_key_degister_many(struct lu_context_key *k, ...);
1248 void lu_context_key_revive_many (struct lu_context_key *k, ...);
1249 void lu_context_key_quiesce_many (struct lu_context_key *k, ...);
1252 * update/clear ctx/ses tags.
1254 void lu_context_tags_update(__u32 tags);
1255 void lu_context_tags_clear(__u32 tags);
1256 void lu_session_tags_update(__u32 tags);
1257 void lu_session_tags_clear(__u32 tags);
1264 * "Local" context, used to store data instead of stack.
1266 struct lu_context le_ctx;
1268 * "Session" context for per-request data.
1270 struct lu_context *le_ses;
1273 int lu_env_init (struct lu_env *env, __u32 tags);
1274 void lu_env_fini (struct lu_env *env);
1275 int lu_env_refill(struct lu_env *env);
1276 int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags, __u32 stags);
1278 /** @} lu_context */
1281 * Output site statistical counters into a buffer. Suitable for
1282 * ll_rd_*()-style functions.
1284 int lu_site_stats_print(const struct lu_site *s, char *page, int count);
1287 * Common name structure to be passed around for various name related methods.
1290 const char *ln_name;
1295 * Common buffer structure to be passed around for various xattr_{s,g}et()
1303 #define DLUBUF "(%p %zu)"
1304 #define PLUBUF(buf) (buf)->lb_buf, (buf)->lb_len
1306 * One-time initializers, called at obdclass module initialization, not
1311 * Initialization of global lu_* data.
1313 int lu_global_init(void);
1316 * Dual to lu_global_init().
1318 void lu_global_fini(void);
1320 struct lu_kmem_descr {
1321 cfs_mem_cache_t **ckd_cache;
1322 const char *ckd_name;
1323 const size_t ckd_size;
1326 int lu_kmem_init(struct lu_kmem_descr *caches);
1327 void lu_kmem_fini(struct lu_kmem_descr *caches);
1329 void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
1330 const struct lu_fid *fid);
1331 struct lu_object *lu_object_anon(const struct lu_env *env,
1332 struct lu_device *dev,
1333 const struct lu_object_conf *conf);
1336 extern struct lu_buf LU_BUF_NULL;
1338 void lu_buf_free(struct lu_buf *buf);
1339 void lu_buf_alloc(struct lu_buf *buf, int size);
1340 void lu_buf_realloc(struct lu_buf *buf, int size);
1342 int lu_buf_check_and_grow(struct lu_buf *buf, int len);
1343 struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len);
1346 #endif /* __LUSTRE_LU_OBJECT_H */