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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,
173 /* When find a dying object, just return -EAGAIN at once instead of
174 * blocking the thread. */
175 LOC_F_NOWAIT = 0x00000002,
179 * Object configuration, describing particulars of object being created. On
180 * server this is not used, as server objects are full identified by fid. On
181 * client configuration contains struct lustre_md.
183 struct lu_object_conf {
185 * Some hints for obj find and alloc.
187 loc_flags_t loc_flags;
191 * Type of "printer" function used by lu_object_operations::loo_object_print()
194 * Printer function is needed to provide some flexibility in (semi-)debugging
195 * output: possible implementations: printk, CDEBUG, sysfs/seq_file
197 typedef int (*lu_printer_t)(const struct lu_env *env,
198 void *cookie, const char *format, ...)
199 __attribute__ ((format (printf, 3, 4)));
202 * Operations specific for particular lu_object.
204 struct lu_object_operations {
207 * Allocate lower-layer parts of the object by calling
208 * lu_device_operations::ldo_object_alloc() of the corresponding
211 * This method is called once for each object inserted into object
212 * stack. It's responsibility of this method to insert lower-layer
213 * object(s) it create into appropriate places of object stack.
215 int (*loo_object_init)(const struct lu_env *env,
217 const struct lu_object_conf *conf);
219 * Called (in top-to-bottom order) during object allocation after all
220 * layers were allocated and initialized. Can be used to perform
221 * initialization depending on lower layers.
223 int (*loo_object_start)(const struct lu_env *env,
224 struct lu_object *o);
226 * Called before lu_object_operations::loo_object_free() to signal
227 * that object is being destroyed. Dual to
228 * lu_object_operations::loo_object_init().
230 void (*loo_object_delete)(const struct lu_env *env,
231 struct lu_object *o);
233 * Dual to lu_device_operations::ldo_object_alloc(). Called when
234 * object is removed from memory.
236 void (*loo_object_free)(const struct lu_env *env,
237 struct lu_object *o);
239 * Called when last active reference to the object is released (and
240 * object returns to the cache). This method is optional.
242 void (*loo_object_release)(const struct lu_env *env,
243 struct lu_object *o);
245 * Optional debugging helper. Print given object.
247 int (*loo_object_print)(const struct lu_env *env, void *cookie,
248 lu_printer_t p, const struct lu_object *o);
250 * Optional debugging method. Returns true iff method is internally
253 int (*loo_object_invariant)(const struct lu_object *o);
259 struct lu_device_type;
262 * Device: a layer in the server side abstraction stacking.
266 * reference count. This is incremented, in particular, on each object
267 * created at this layer.
269 * \todo XXX which means that atomic_t is probably too small.
273 * Pointer to device type. Never modified once set.
275 struct lu_device_type *ld_type;
277 * Operation vector for this device.
279 const struct lu_device_operations *ld_ops;
281 * Stack this device belongs to.
283 struct lu_site *ld_site;
284 struct proc_dir_entry *ld_proc_entry;
286 /** \todo XXX: temporary back pointer into obd. */
287 struct obd_device *ld_obd;
289 * A list of references to this object, for debugging.
291 struct lu_ref ld_reference;
293 * Link the device to the site.
295 struct list_head ld_linkage;
298 struct lu_device_type_operations;
301 * Tag bits for device type. They are used to distinguish certain groups of
305 /** this is meta-data device */
306 LU_DEVICE_MD = (1 << 0),
307 /** this is data device */
308 LU_DEVICE_DT = (1 << 1),
309 /** data device in the client stack */
310 LU_DEVICE_CL = (1 << 2)
316 struct lu_device_type {
318 * Tag bits. Taken from enum lu_device_tag. Never modified once set.
322 * Name of this class. Unique system-wide. Never modified once set.
326 * Operations for this type.
328 const struct lu_device_type_operations *ldt_ops;
330 * \todo XXX: temporary pointer to associated obd_type.
332 struct obd_type *ldt_obd_type;
334 * \todo XXX: temporary: context tags used by obd_*() calls.
338 * Number of existing device type instances.
340 atomic_t ldt_device_nr;
342 * Linkage into a global list of all device types.
344 * \see lu_device_types.
346 struct list_head ldt_linkage;
350 * Operations on a device type.
352 struct lu_device_type_operations {
354 * Allocate new device.
356 struct lu_device *(*ldto_device_alloc)(const struct lu_env *env,
357 struct lu_device_type *t,
358 struct lustre_cfg *lcfg);
360 * Free device. Dual to
361 * lu_device_type_operations::ldto_device_alloc(). Returns pointer to
362 * the next device in the stack.
364 struct lu_device *(*ldto_device_free)(const struct lu_env *,
368 * Initialize the devices after allocation
370 int (*ldto_device_init)(const struct lu_env *env,
371 struct lu_device *, const char *,
374 * Finalize device. Dual to
375 * lu_device_type_operations::ldto_device_init(). Returns pointer to
376 * the next device in the stack.
378 struct lu_device *(*ldto_device_fini)(const struct lu_env *env,
381 * Initialize device type. This is called on module load.
383 int (*ldto_init)(struct lu_device_type *t);
385 * Finalize device type. Dual to
386 * lu_device_type_operations::ldto_init(). Called on module unload.
388 void (*ldto_fini)(struct lu_device_type *t);
390 * Called when the first device is created.
392 void (*ldto_start)(struct lu_device_type *t);
394 * Called when number of devices drops to 0.
396 void (*ldto_stop)(struct lu_device_type *t);
399 static inline int lu_device_is_md(const struct lu_device *d)
401 return ergo(d != NULL, d->ld_type->ldt_tags & LU_DEVICE_MD);
405 * Common object attributes.
410 /** modification time in seconds since Epoch */
412 /** access time in seconds since Epoch */
414 /** change time in seconds since Epoch */
416 /** 512-byte blocks allocated to object */
418 /** permission bits and file type */
426 /** number of persistent references to this object */
428 /** blk bits of the object*/
430 /** blk size of the object*/
442 /** Bit-mask of valid attributes */
456 LA_BLKSIZE = 1 << 12,
457 LA_KILL_SUID = 1 << 13,
458 LA_KILL_SGID = 1 << 14,
462 * Layer in the layered object.
466 * Header for this object.
468 struct lu_object_header *lo_header;
470 * Device for this layer.
472 struct lu_device *lo_dev;
474 * Operations for this object.
476 const struct lu_object_operations *lo_ops;
478 * Linkage into list of all layers.
480 struct list_head lo_linkage;
482 * Link to the device, for debugging.
484 struct lu_ref_link lo_dev_ref;
487 enum lu_object_header_flags {
489 * Don't keep this object in cache. Object will be destroyed as soon
490 * as last reference to it is released. This flag cannot be cleared
493 LU_OBJECT_HEARD_BANSHEE = 0,
495 * Mark this object has already been taken out of cache.
497 LU_OBJECT_UNHASHED = 1,
500 enum lu_object_header_attr {
501 LOHA_EXISTS = 1 << 0,
502 LOHA_REMOTE = 1 << 1,
504 * UNIX file type is stored in S_IFMT bits.
506 LOHA_FT_START = 001 << 12, /**< S_IFIFO */
507 LOHA_FT_END = 017 << 12, /**< S_IFMT */
511 * "Compound" object, consisting of multiple layers.
513 * Compound object with given fid is unique with given lu_site.
515 * Note, that object does *not* necessary correspond to the real object in the
516 * persistent storage: object is an anchor for locking and method calling, so
517 * it is created for things like not-yet-existing child created by mkdir or
518 * create calls. lu_object_operations::loo_exists() can be used to check
519 * whether object is backed by persistent storage entity.
521 struct lu_object_header {
523 * Fid, uniquely identifying this object.
525 struct lu_fid loh_fid;
527 * Object flags from enum lu_object_header_flags. Set and checked
530 unsigned long loh_flags;
532 * Object reference count. Protected by lu_site::ls_guard.
536 * Common object attributes, cached for efficiency. From enum
537 * lu_object_header_attr.
541 * Linkage into per-site hash table. Protected by lu_site::ls_guard.
543 struct hlist_node loh_hash;
545 * Linkage into per-site LRU list. Protected by lu_site::ls_guard.
547 struct list_head loh_lru;
549 * Linkage into list of layers. Never modified once set (except lately
550 * during object destruction). No locking is necessary.
552 struct list_head loh_layers;
554 * A list of references to this object, for debugging.
556 struct lu_ref loh_reference;
561 struct lu_site_bkt_data {
563 * number of busy object on this bucket
567 * LRU list, updated on each access to object. Protected by
568 * bucket lock of lu_site::ls_obj_hash.
570 * "Cold" end of LRU is lu_site::ls_lru.next. Accessed object are
571 * moved to the lu_site::ls_lru.prev (this is due to the non-existence
572 * of list_for_each_entry_safe_reverse()).
574 struct list_head lsb_lru;
576 * Wait-queue signaled when an object in this site is ultimately
577 * destroyed (lu_object_free()). It is used by lu_object_find() to
578 * wait before re-trying when object in the process of destruction is
579 * found in the hash table.
581 * \see htable_lookup().
583 wait_queue_head_t lsb_marche_funebre;
591 LU_SS_CACHE_DEATH_RACE,
597 * lu_site is a "compartment" within which objects are unique, and LRU
598 * discipline is maintained.
600 * lu_site exists so that multiple layered stacks can co-exist in the same
603 * lu_site has the same relation to lu_device as lu_object_header to
610 cfs_hash_t *ls_obj_hash;
612 * index of bucket on hash table while purging
616 * Top-level device for this stack.
618 struct lu_device *ls_top_dev;
620 * Bottom-level device for this stack
622 struct lu_device *ls_bottom_dev;
624 * Linkage into global list of sites.
626 struct list_head ls_linkage;
628 * List for lu device for this site, protected
631 struct list_head ls_ld_linkage;
632 spinlock_t ls_ld_lock;
634 * Lock to serialize site purge.
636 struct mutex ls_purge_mutex;
640 struct lprocfs_stats *ls_stats;
642 * XXX: a hack! fld has to find md_site via site, remove when possible
644 struct seq_server_site *ld_seq_site;
647 static inline struct lu_site_bkt_data *
648 lu_site_bkt_from_fid(struct lu_site *site, struct lu_fid *fid)
652 cfs_hash_bd_get(site->ls_obj_hash, fid, &bd);
653 return cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
656 static inline struct seq_server_site *lu_site2seq(const struct lu_site *s)
658 return s->ld_seq_site;
662 * Constructors/destructors.
666 int lu_site_init (struct lu_site *s, struct lu_device *d);
667 void lu_site_fini (struct lu_site *s);
668 int lu_site_init_finish (struct lu_site *s);
669 void lu_stack_fini (const struct lu_env *env, struct lu_device *top);
670 void lu_device_get (struct lu_device *d);
671 void lu_device_put (struct lu_device *d);
672 int lu_device_init (struct lu_device *d, struct lu_device_type *t);
673 void lu_device_fini (struct lu_device *d);
674 int lu_object_header_init(struct lu_object_header *h);
675 void lu_object_header_fini(struct lu_object_header *h);
676 int lu_object_init (struct lu_object *o,
677 struct lu_object_header *h, struct lu_device *d);
678 void lu_object_fini (struct lu_object *o);
679 void lu_object_add_top (struct lu_object_header *h, struct lu_object *o);
680 void lu_object_add (struct lu_object *before, struct lu_object *o);
682 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d);
683 void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d);
686 * Helpers to initialize and finalize device types.
689 int lu_device_type_init(struct lu_device_type *ldt);
690 void lu_device_type_fini(struct lu_device_type *ldt);
695 * Caching and reference counting.
700 * Acquire additional reference to the given object. This function is used to
701 * attain additional reference. To acquire initial reference use
704 static inline void lu_object_get(struct lu_object *o)
706 LASSERT(atomic_read(&o->lo_header->loh_ref) > 0);
707 atomic_inc(&o->lo_header->loh_ref);
711 * Return true of object will not be cached after last reference to it is
714 static inline int lu_object_is_dying(const struct lu_object_header *h)
716 return test_bit(LU_OBJECT_HEARD_BANSHEE, &h->loh_flags);
719 void lu_object_put(const struct lu_env *env, struct lu_object *o);
720 void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o);
721 void lu_object_unhash(const struct lu_env *env, struct lu_object *o);
723 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr);
725 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
726 lu_printer_t printer);
727 struct lu_object *lu_object_find(const struct lu_env *env,
728 struct lu_device *dev, const struct lu_fid *f,
729 const struct lu_object_conf *conf);
730 struct lu_object *lu_object_find_at(const struct lu_env *env,
731 struct lu_device *dev,
732 const struct lu_fid *f,
733 const struct lu_object_conf *conf);
734 void lu_object_purge(const struct lu_env *env, struct lu_device *dev,
735 const struct lu_fid *f);
736 struct lu_object *lu_object_find_slice(const struct lu_env *env,
737 struct lu_device *dev,
738 const struct lu_fid *f,
739 const struct lu_object_conf *conf);
748 * First (topmost) sub-object of given compound object
750 static inline struct lu_object *lu_object_top(struct lu_object_header *h)
752 LASSERT(!list_empty(&h->loh_layers));
753 return container_of0(h->loh_layers.next, struct lu_object, lo_linkage);
757 * Next sub-object in the layering
759 static inline struct lu_object *lu_object_next(const struct lu_object *o)
761 return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage);
765 * Pointer to the fid of this object.
767 static inline const struct lu_fid *lu_object_fid(const struct lu_object *o)
769 return &o->lo_header->loh_fid;
773 * return device operations vector for this object
775 static const inline struct lu_device_operations *
776 lu_object_ops(const struct lu_object *o)
778 return o->lo_dev->ld_ops;
782 * Given a compound object, find its slice, corresponding to the device type
785 struct lu_object *lu_object_locate(struct lu_object_header *h,
786 const struct lu_device_type *dtype);
789 * Printer function emitting messages through libcfs_debug_msg().
791 int lu_cdebug_printer(const struct lu_env *env,
792 void *cookie, const char *format, ...);
795 * Print object description followed by a user-supplied message.
797 #define LU_OBJECT_DEBUG(mask, env, object, format, ...) \
799 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \
800 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \
801 lu_object_print(env, &msgdata, lu_cdebug_printer, object);\
802 CDEBUG(mask, format , ## __VA_ARGS__); \
807 * Print short object description followed by a user-supplied message.
809 #define LU_OBJECT_HEADER(mask, env, object, format, ...) \
811 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \
812 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \
813 lu_object_header_print(env, &msgdata, lu_cdebug_printer,\
814 (object)->lo_header); \
815 lu_cdebug_printer(env, &msgdata, "\n"); \
816 CDEBUG(mask, format , ## __VA_ARGS__); \
820 void lu_object_print (const struct lu_env *env, void *cookie,
821 lu_printer_t printer, const struct lu_object *o);
822 void lu_object_header_print(const struct lu_env *env, void *cookie,
823 lu_printer_t printer,
824 const struct lu_object_header *hdr);
827 * Check object consistency.
829 int lu_object_invariant(const struct lu_object *o);
833 * Check whether object exists, no matter on local or remote storage.
834 * Note: LOHA_EXISTS will be set once some one created the object,
835 * and it does not needs to be committed to storage.
837 #define lu_object_exists(o) ((o)->lo_header->loh_attr & LOHA_EXISTS)
840 * Check whether object on the remote storage.
842 #define lu_object_remote(o) unlikely((o)->lo_header->loh_attr & LOHA_REMOTE)
844 static inline int lu_object_assert_exists(const struct lu_object *o)
846 return lu_object_exists(o);
849 static inline int lu_object_assert_not_exists(const struct lu_object *o)
851 return !lu_object_exists(o);
855 * Attr of this object.
857 static inline __u32 lu_object_attr(const struct lu_object *o)
859 LASSERT(lu_object_exists(o) != 0);
860 return o->lo_header->loh_attr;
863 static inline void lu_object_ref_add(struct lu_object *o,
867 lu_ref_add(&o->lo_header->loh_reference, scope, source);
870 static inline void lu_object_ref_add_at(struct lu_object *o,
871 struct lu_ref_link *link,
875 lu_ref_add_at(&o->lo_header->loh_reference, link, 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 struct list_head 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 * session for server thread
1025 LCT_SERVER_SESSION = 1 << 8,
1027 * Set when at least one of keys, having values in this context has
1028 * non-NULL lu_context_key::lct_exit() method. This is used to
1029 * optimize lu_context_exit() call.
1031 LCT_HAS_EXIT = 1 << 28,
1033 * Don't add references for modules creating key values in that context.
1034 * This is only for contexts used internally by lu_object framework.
1036 LCT_NOREF = 1 << 29,
1038 * Key is being prepared for retiring, don't create new values for it.
1040 LCT_QUIESCENT = 1 << 30,
1042 * Context should be remembered.
1044 LCT_REMEMBER = 1 << 31,
1046 * Contexts usable in cache shrinker thread.
1048 LCT_SHRINKER = LCT_MD_THREAD|LCT_DT_THREAD|LCT_CL_THREAD|LCT_NOREF
1052 * Key. Represents per-context value slot.
1054 * Keys are usually registered when module owning the key is initialized, and
1055 * de-registered when module is unloaded. Once key is registered, all new
1056 * contexts with matching tags, will get key value. "Old" contexts, already
1057 * initialized at the time of key registration, can be forced to get key value
1058 * by calling lu_context_refill().
1060 * Every key value is counted in lu_context_key::lct_used and acquires a
1061 * reference on an owning module. This means, that all key values have to be
1062 * destroyed before module can be unloaded. This is usually achieved by
1063 * stopping threads started by the module, that created contexts in their
1064 * entry functions. Situation is complicated by the threads shared by multiple
1065 * modules, like ptlrpcd daemon on a client. To work around this problem,
1066 * contexts, created in such threads, are `remembered' (see
1067 * LCT_REMEMBER)---i.e., added into a global list. When module is preparing
1068 * for unloading it does the following:
1070 * - marks its keys as `quiescent' (lu_context_tag::LCT_QUIESCENT)
1071 * preventing new key values from being allocated in the new contexts,
1074 * - scans a list of remembered contexts, destroying values of module
1075 * keys, thus releasing references to the module.
1077 * This is done by lu_context_key_quiesce(). If module is re-activated
1078 * before key has been de-registered, lu_context_key_revive() call clears
1079 * `quiescent' marker.
1081 * lu_context code doesn't provide any internal synchronization for these
1082 * activities---it's assumed that startup (including threads start-up) and
1083 * shutdown are serialized by some external means.
1087 struct lu_context_key {
1089 * Set of tags for which values of this key are to be instantiated.
1093 * Value constructor. This is called when new value is created for a
1094 * context. Returns pointer to new value of error pointer.
1096 void *(*lct_init)(const struct lu_context *ctx,
1097 struct lu_context_key *key);
1099 * Value destructor. Called when context with previously allocated
1100 * value of this slot is destroyed. \a data is a value that was returned
1101 * by a matching call to lu_context_key::lct_init().
1103 void (*lct_fini)(const struct lu_context *ctx,
1104 struct lu_context_key *key, void *data);
1106 * Optional method called on lu_context_exit() for all allocated
1107 * keys. Can be used by debugging code checking that locks are
1110 void (*lct_exit)(const struct lu_context *ctx,
1111 struct lu_context_key *key, void *data);
1113 * Internal implementation detail: index within lu_context::lc_value[]
1114 * reserved for this key.
1118 * Internal implementation detail: number of values created for this
1123 * Internal implementation detail: module for this key.
1125 struct module *lct_owner;
1127 * References to this key. For debugging.
1129 struct lu_ref lct_reference;
1132 #define LU_KEY_INIT(mod, type) \
1133 static void* mod##_key_init(const struct lu_context *ctx, \
1134 struct lu_context_key *key) \
1138 CLASSERT(PAGE_CACHE_SIZE >= sizeof (*value)); \
1140 OBD_ALLOC_PTR(value); \
1141 if (value == NULL) \
1142 value = ERR_PTR(-ENOMEM); \
1146 struct __##mod##__dummy_init {;} /* semicolon catcher */
1148 #define LU_KEY_FINI(mod, type) \
1149 static void mod##_key_fini(const struct lu_context *ctx, \
1150 struct lu_context_key *key, void* data) \
1152 type *info = data; \
1154 OBD_FREE_PTR(info); \
1156 struct __##mod##__dummy_fini {;} /* semicolon catcher */
1158 #define LU_KEY_INIT_FINI(mod, type) \
1159 LU_KEY_INIT(mod,type); \
1160 LU_KEY_FINI(mod,type)
1162 #define LU_CONTEXT_KEY_DEFINE(mod, tags) \
1163 struct lu_context_key mod##_thread_key = { \
1165 .lct_init = mod##_key_init, \
1166 .lct_fini = mod##_key_fini \
1169 #define LU_CONTEXT_KEY_INIT(key) \
1171 (key)->lct_owner = THIS_MODULE; \
1174 int lu_context_key_register(struct lu_context_key *key);
1175 void lu_context_key_degister(struct lu_context_key *key);
1176 void *lu_context_key_get (const struct lu_context *ctx,
1177 const struct lu_context_key *key);
1178 void lu_context_key_quiesce (struct lu_context_key *key);
1179 void lu_context_key_revive (struct lu_context_key *key);
1183 * LU_KEY_INIT_GENERIC() has to be a macro to correctly determine an
1187 #define LU_KEY_INIT_GENERIC(mod) \
1188 static void mod##_key_init_generic(struct lu_context_key *k, ...) \
1190 struct lu_context_key *key = k; \
1193 va_start(args, k); \
1195 LU_CONTEXT_KEY_INIT(key); \
1196 key = va_arg(args, struct lu_context_key *); \
1197 } while (key != NULL); \
1201 #define LU_TYPE_INIT(mod, ...) \
1202 LU_KEY_INIT_GENERIC(mod) \
1203 static int mod##_type_init(struct lu_device_type *t) \
1205 mod##_key_init_generic(__VA_ARGS__, NULL); \
1206 return lu_context_key_register_many(__VA_ARGS__, NULL); \
1208 struct __##mod##_dummy_type_init {;}
1210 #define LU_TYPE_FINI(mod, ...) \
1211 static void mod##_type_fini(struct lu_device_type *t) \
1213 lu_context_key_degister_many(__VA_ARGS__, NULL); \
1215 struct __##mod##_dummy_type_fini {;}
1217 #define LU_TYPE_START(mod, ...) \
1218 static void mod##_type_start(struct lu_device_type *t) \
1220 lu_context_key_revive_many(__VA_ARGS__, NULL); \
1222 struct __##mod##_dummy_type_start {;}
1224 #define LU_TYPE_STOP(mod, ...) \
1225 static void mod##_type_stop(struct lu_device_type *t) \
1227 lu_context_key_quiesce_many(__VA_ARGS__, NULL); \
1229 struct __##mod##_dummy_type_stop {;}
1233 #define LU_TYPE_INIT_FINI(mod, ...) \
1234 LU_TYPE_INIT(mod, __VA_ARGS__); \
1235 LU_TYPE_FINI(mod, __VA_ARGS__); \
1236 LU_TYPE_START(mod, __VA_ARGS__); \
1237 LU_TYPE_STOP(mod, __VA_ARGS__)
1239 int lu_context_init (struct lu_context *ctx, __u32 tags);
1240 void lu_context_fini (struct lu_context *ctx);
1241 void lu_context_enter (struct lu_context *ctx);
1242 void lu_context_exit (struct lu_context *ctx);
1243 int lu_context_refill(struct lu_context *ctx);
1246 * Helper functions to operate on multiple keys. These are used by the default
1247 * device type operations, defined by LU_TYPE_INIT_FINI().
1250 int lu_context_key_register_many(struct lu_context_key *k, ...);
1251 void lu_context_key_degister_many(struct lu_context_key *k, ...);
1252 void lu_context_key_revive_many (struct lu_context_key *k, ...);
1253 void lu_context_key_quiesce_many (struct lu_context_key *k, ...);
1256 * update/clear ctx/ses tags.
1258 void lu_context_tags_update(__u32 tags);
1259 void lu_context_tags_clear(__u32 tags);
1260 void lu_session_tags_update(__u32 tags);
1261 void lu_session_tags_clear(__u32 tags);
1268 * "Local" context, used to store data instead of stack.
1270 struct lu_context le_ctx;
1272 * "Session" context for per-request data.
1274 struct lu_context *le_ses;
1277 int lu_env_init (struct lu_env *env, __u32 tags);
1278 void lu_env_fini (struct lu_env *env);
1279 int lu_env_refill(struct lu_env *env);
1280 int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags, __u32 stags);
1282 /** @} lu_context */
1285 * Output site statistical counters into a buffer. Suitable for
1286 * ll_rd_*()-style functions.
1288 int lu_site_stats_seq_print(const struct lu_site *s, struct seq_file *m);
1289 int lu_site_stats_print(const struct lu_site *s, char *page, int count);
1292 * Common name structure to be passed around for various name related methods.
1295 const char *ln_name;
1300 * Validate names (path components)
1302 * To be valid \a name must be non-empty, '\0' terminated of length \a
1303 * name_len, and not contain '/'. The maximum length of a name (before
1304 * say -ENAMETOOLONG will be returned) is really controlled by llite
1305 * and the server. We only check for something insane coming from bad
1306 * integer handling here.
1308 static inline bool lu_name_is_valid_2(const char *name, size_t name_len)
1310 return name != NULL &&
1312 name_len < INT_MAX &&
1313 name[name_len] == '\0' &&
1314 strlen(name) == name_len &&
1315 memchr(name, '/', name_len) == NULL;
1318 static inline bool lu_name_is_valid(const struct lu_name *ln)
1320 return lu_name_is_valid_2(ln->ln_name, ln->ln_namelen);
1323 #define DNAME "%.*s"
1325 (lu_name_is_valid(ln) ? (ln)->ln_namelen : 0), \
1326 (lu_name_is_valid(ln) ? (ln)->ln_name : "")
1329 * Common buffer structure to be passed around for various xattr_{s,g}et()
1337 #define DLUBUF "(%p %zu)"
1338 #define PLUBUF(buf) (buf)->lb_buf, (buf)->lb_len
1340 * One-time initializers, called at obdclass module initialization, not
1345 * Initialization of global lu_* data.
1347 int lu_global_init(void);
1350 * Dual to lu_global_init().
1352 void lu_global_fini(void);
1354 struct lu_kmem_descr {
1355 struct kmem_cache **ckd_cache;
1356 const char *ckd_name;
1357 const size_t ckd_size;
1360 int lu_kmem_init(struct lu_kmem_descr *caches);
1361 void lu_kmem_fini(struct lu_kmem_descr *caches);
1363 void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
1364 const struct lu_fid *fid);
1365 struct lu_object *lu_object_anon(const struct lu_env *env,
1366 struct lu_device *dev,
1367 const struct lu_object_conf *conf);
1370 extern struct lu_buf LU_BUF_NULL;
1372 void lu_buf_free(struct lu_buf *buf);
1373 void lu_buf_alloc(struct lu_buf *buf, size_t size);
1374 void lu_buf_realloc(struct lu_buf *buf, size_t size);
1376 int lu_buf_check_and_grow(struct lu_buf *buf, size_t len);
1377 struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, size_t len);
1380 #endif /* __LUSTRE_LU_OBJECT_H */