1/* 2 * GPL HEADER START 3 * 4 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. 5 * 6 * This program is free software; you can redistribute it and/or modify 7 * it under the terms of the GNU General Public License version 2 only, 8 * as published by the Free Software Foundation. 9 * 10 * This program is distributed in the hope that it will be useful, but 11 * WITHOUT ANY WARRANTY; without even the implied warranty of 12 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU 13 * General Public License version 2 for more details (a copy is included 14 * in the LICENSE file that accompanied this code). 15 * 16 * You should have received a copy of the GNU General Public License 17 * version 2 along with this program; If not, see 18 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf 19 * 20 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara, 21 * CA 95054 USA or visit www.sun.com if you need additional information or 22 * have any questions. 23 * 24 * GPL HEADER END 25 */ 26/* 27 * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. 28 * Use is subject to license terms. 29 * 30 * Copyright (c) 2011, 2012, Intel Corporation. 31 */ 32/* 33 * This file is part of Lustre, http://www.lustre.org/ 34 * Lustre is a trademark of Sun Microsystems, Inc. 35 */ 36 37#ifndef __LUSTRE_LU_OBJECT_H 38#define __LUSTRE_LU_OBJECT_H 39 40#include <stdarg.h> 41#include "../../include/linux/libcfs/libcfs.h" 42#include "lustre/lustre_idl.h" 43#include "lu_ref.h" 44 45struct seq_file; 46struct proc_dir_entry; 47struct lustre_cfg; 48struct lprocfs_stats; 49 50/** \defgroup lu lu 51 * lu_* data-types represent server-side entities shared by data and meta-data 52 * stacks. 53 * 54 * Design goals: 55 * 56 * -# support for layering. 57 * 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 63 * reasons: 64 * 65 * - it's envisaged that lu_object will be used much more often than 66 * lu_object_header; 67 * 68 * - we want lower (non-top) layers to be able to initiate operations 69 * on the whole object. 70 * 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 73 * on the lower layer. 74 * 75 * -# fid-based identification. 76 * 77 * Compound object is uniquely identified by its fid. Objects are indexed 78 * by their fids (hash table is used for index). 79 * 80 * -# caching and life-cycle management. 81 * 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. 85 * 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 88 * the LRU. 89 * 90 * -# avoiding recursion. 91 * 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. 96 * @{ 97 */ 98 99struct lu_site; 100struct lu_object; 101struct lu_device; 102struct lu_object_header; 103struct lu_context; 104struct lu_env; 105 106/** 107 * Operations common for data and meta-data devices. 108 */ 109struct lu_device_operations { 110 /** 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. 115 * 116 * Object creation protocol. 117 * 118 * Due to design goal of avoiding recursion, object creation (see 119 * lu_object_alloc()) is somewhat involved: 120 * 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). 125 * 126 * - then lu_object_alloc() sets fid in the header of newly created 127 * object. 128 * 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). 133 * 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. 138 * 139 * \post ergo(!IS_ERR(result), result->lo_dev == d && 140 * result->lo_ops != NULL); 141 */ 142 struct lu_object *(*ldo_object_alloc)(const struct lu_env *env, 143 const struct lu_object_header *h, 144 struct lu_device *d); 145 /** 146 * process config specific for device. 147 */ 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 *, 151 struct lu_device *); 152 153 /** 154 * initialize local objects for device. this method called after layer has 155 * been initialized (after LCFG_SETUP stage) and before it starts serving 156 * user requests. 157 */ 158 159 int (*ldo_prepare)(const struct lu_env *, 160 struct lu_device *parent, 161 struct lu_device *dev); 162 163}; 164 165/** 166 * For lu_object_conf flags 167 */ 168typedef enum { 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, 172} loc_flags_t; 173 174/** 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. 178 */ 179struct lu_object_conf { 180 /** 181 * Some hints for obj find and alloc. 182 */ 183 loc_flags_t loc_flags; 184}; 185 186/** 187 * Type of "printer" function used by lu_object_operations::loo_object_print() 188 * method. 189 * 190 * Printer function is needed to provide some flexibility in (semi-)debugging 191 * output: possible implementations: printk, CDEBUG, sysfs/seq_file 192 */ 193typedef int (*lu_printer_t)(const struct lu_env *env, 194 void *cookie, const char *format, ...) 195 __attribute__ ((format (printf, 3, 4))); 196 197/** 198 * Operations specific for particular lu_object. 199 */ 200struct lu_object_operations { 201 202 /** 203 * Allocate lower-layer parts of the object by calling 204 * lu_device_operations::ldo_object_alloc() of the corresponding 205 * underlying device. 206 * 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. 210 */ 211 int (*loo_object_init)(const struct lu_env *env, 212 struct lu_object *o, 213 const struct lu_object_conf *conf); 214 /** 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. 218 */ 219 int (*loo_object_start)(const struct lu_env *env, 220 struct lu_object *o); 221 /** 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(). 225 */ 226 void (*loo_object_delete)(const struct lu_env *env, 227 struct lu_object *o); 228 /** 229 * Dual to lu_device_operations::ldo_object_alloc(). Called when 230 * object is removed from memory. 231 */ 232 void (*loo_object_free)(const struct lu_env *env, 233 struct lu_object *o); 234 /** 235 * Called when last active reference to the object is released (and 236 * object returns to the cache). This method is optional. 237 */ 238 void (*loo_object_release)(const struct lu_env *env, 239 struct lu_object *o); 240 /** 241 * Optional debugging helper. Print given object. 242 */ 243 int (*loo_object_print)(const struct lu_env *env, void *cookie, 244 lu_printer_t p, const struct lu_object *o); 245 /** 246 * Optional debugging method. Returns true iff method is internally 247 * consistent. 248 */ 249 int (*loo_object_invariant)(const struct lu_object *o); 250}; 251 252/** 253 * Type of lu_device. 254 */ 255struct lu_device_type; 256 257/** 258 * Device: a layer in the server side abstraction stacking. 259 */ 260struct lu_device { 261 /** 262 * reference count. This is incremented, in particular, on each object 263 * created at this layer. 264 * 265 * \todo XXX which means that atomic_t is probably too small. 266 */ 267 atomic_t ld_ref; 268 /** 269 * Pointer to device type. Never modified once set. 270 */ 271 struct lu_device_type *ld_type; 272 /** 273 * Operation vector for this device. 274 */ 275 const struct lu_device_operations *ld_ops; 276 /** 277 * Stack this device belongs to. 278 */ 279 struct lu_site *ld_site; 280 struct proc_dir_entry *ld_proc_entry; 281 282 /** \todo XXX: temporary back pointer into obd. */ 283 struct obd_device *ld_obd; 284 /** 285 * A list of references to this object, for debugging. 286 */ 287 struct lu_ref ld_reference; 288 /** 289 * Link the device to the site. 290 **/ 291 struct list_head ld_linkage; 292}; 293 294struct lu_device_type_operations; 295 296/** 297 * Tag bits for device type. They are used to distinguish certain groups of 298 * device types. 299 */ 300enum lu_device_tag { 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) 307}; 308 309/** 310 * Type of device. 311 */ 312struct lu_device_type { 313 /** 314 * Tag bits. Taken from enum lu_device_tag. Never modified once set. 315 */ 316 __u32 ldt_tags; 317 /** 318 * Name of this class. Unique system-wide. Never modified once set. 319 */ 320 char *ldt_name; 321 /** 322 * Operations for this type. 323 */ 324 const struct lu_device_type_operations *ldt_ops; 325 /** 326 * \todo XXX: temporary pointer to associated obd_type. 327 */ 328 struct obd_type *ldt_obd_type; 329 /** 330 * \todo XXX: temporary: context tags used by obd_*() calls. 331 */ 332 __u32 ldt_ctx_tags; 333 /** 334 * Number of existing device type instances. 335 */ 336 unsigned ldt_device_nr; 337 /** 338 * Linkage into a global list of all device types. 339 * 340 * \see lu_device_types. 341 */ 342 struct list_head ldt_linkage; 343}; 344 345/** 346 * Operations on a device type. 347 */ 348struct lu_device_type_operations { 349 /** 350 * Allocate new device. 351 */ 352 struct lu_device *(*ldto_device_alloc)(const struct lu_env *env, 353 struct lu_device_type *t, 354 struct lustre_cfg *lcfg); 355 /** 356 * Free device. Dual to 357 * lu_device_type_operations::ldto_device_alloc(). Returns pointer to 358 * the next device in the stack. 359 */ 360 struct lu_device *(*ldto_device_free)(const struct lu_env *, 361 struct lu_device *); 362 363 /** 364 * Initialize the devices after allocation 365 */ 366 int (*ldto_device_init)(const struct lu_env *env, 367 struct lu_device *, const char *, 368 struct lu_device *); 369 /** 370 * Finalize device. Dual to 371 * lu_device_type_operations::ldto_device_init(). Returns pointer to 372 * the next device in the stack. 373 */ 374 struct lu_device *(*ldto_device_fini)(const struct lu_env *env, 375 struct lu_device *); 376 /** 377 * Initialize device type. This is called on module load. 378 */ 379 int (*ldto_init)(struct lu_device_type *t); 380 /** 381 * Finalize device type. Dual to 382 * lu_device_type_operations::ldto_init(). Called on module unload. 383 */ 384 void (*ldto_fini)(struct lu_device_type *t); 385 /** 386 * Called when the first device is created. 387 */ 388 void (*ldto_start)(struct lu_device_type *t); 389 /** 390 * Called when number of devices drops to 0. 391 */ 392 void (*ldto_stop)(struct lu_device_type *t); 393}; 394 395static inline int lu_device_is_md(const struct lu_device *d) 396{ 397 return ergo(d != NULL, d->ld_type->ldt_tags & LU_DEVICE_MD); 398} 399 400/** 401 * Common object attributes. 402 */ 403struct lu_attr { 404 /** size in bytes */ 405 __u64 la_size; 406 /** modification time in seconds since Epoch */ 407 s64 la_mtime; 408 /** access time in seconds since Epoch */ 409 s64 la_atime; 410 /** change time in seconds since Epoch */ 411 s64 la_ctime; 412 /** 512-byte blocks allocated to object */ 413 __u64 la_blocks; 414 /** permission bits and file type */ 415 __u32 la_mode; 416 /** owner id */ 417 __u32 la_uid; 418 /** group id */ 419 __u32 la_gid; 420 /** object flags */ 421 __u32 la_flags; 422 /** number of persistent references to this object */ 423 __u32 la_nlink; 424 /** blk bits of the object*/ 425 __u32 la_blkbits; 426 /** blk size of the object*/ 427 __u32 la_blksize; 428 /** real device */ 429 __u32 la_rdev; 430 /** 431 * valid bits 432 * 433 * \see enum la_valid 434 */ 435 __u64 la_valid; 436}; 437 438/** Bit-mask of valid attributes */ 439enum la_valid { 440 LA_ATIME = 1 << 0, 441 LA_MTIME = 1 << 1, 442 LA_CTIME = 1 << 2, 443 LA_SIZE = 1 << 3, 444 LA_MODE = 1 << 4, 445 LA_UID = 1 << 5, 446 LA_GID = 1 << 6, 447 LA_BLOCKS = 1 << 7, 448 LA_TYPE = 1 << 8, 449 LA_FLAGS = 1 << 9, 450 LA_NLINK = 1 << 10, 451 LA_RDEV = 1 << 11, 452 LA_BLKSIZE = 1 << 12, 453 LA_KILL_SUID = 1 << 13, 454 LA_KILL_SGID = 1 << 14, 455}; 456 457/** 458 * Layer in the layered object. 459 */ 460struct lu_object { 461 /** 462 * Header for this object. 463 */ 464 struct lu_object_header *lo_header; 465 /** 466 * Device for this layer. 467 */ 468 struct lu_device *lo_dev; 469 /** 470 * Operations for this object. 471 */ 472 const struct lu_object_operations *lo_ops; 473 /** 474 * Linkage into list of all layers. 475 */ 476 struct list_head lo_linkage; 477 /** 478 * Link to the device, for debugging. 479 */ 480 struct lu_ref_link lo_dev_ref; 481}; 482 483enum lu_object_header_flags { 484 /** 485 * Don't keep this object in cache. Object will be destroyed as soon 486 * as last reference to it is released. This flag cannot be cleared 487 * once set. 488 */ 489 LU_OBJECT_HEARD_BANSHEE = 0, 490 /** 491 * Mark this object has already been taken out of cache. 492 */ 493 LU_OBJECT_UNHASHED = 1 494}; 495 496enum lu_object_header_attr { 497 LOHA_EXISTS = 1 << 0, 498 LOHA_REMOTE = 1 << 1, 499 /** 500 * UNIX file type is stored in S_IFMT bits. 501 */ 502 LOHA_FT_START = 001 << 12, /**< S_IFIFO */ 503 LOHA_FT_END = 017 << 12, /**< S_IFMT */ 504}; 505 506/** 507 * "Compound" object, consisting of multiple layers. 508 * 509 * Compound object with given fid is unique with given lu_site. 510 * 511 * Note, that object does *not* necessary correspond to the real object in the 512 * persistent storage: object is an anchor for locking and method calling, so 513 * it is created for things like not-yet-existing child created by mkdir or 514 * create calls. lu_object_operations::loo_exists() can be used to check 515 * whether object is backed by persistent storage entity. 516 */ 517struct lu_object_header { 518 /** 519 * Fid, uniquely identifying this object. 520 */ 521 struct lu_fid loh_fid; 522 /** 523 * Object flags from enum lu_object_header_flags. Set and checked 524 * atomically. 525 */ 526 unsigned long loh_flags; 527 /** 528 * Object reference count. Protected by lu_site::ls_guard. 529 */ 530 atomic_t loh_ref; 531 /** 532 * Common object attributes, cached for efficiency. From enum 533 * lu_object_header_attr. 534 */ 535 __u32 loh_attr; 536 /** 537 * Linkage into per-site hash table. Protected by lu_site::ls_guard. 538 */ 539 struct hlist_node loh_hash; 540 /** 541 * Linkage into per-site LRU list. Protected by lu_site::ls_guard. 542 */ 543 struct list_head loh_lru; 544 /** 545 * Linkage into list of layers. Never modified once set (except lately 546 * during object destruction). No locking is necessary. 547 */ 548 struct list_head loh_layers; 549 /** 550 * A list of references to this object, for debugging. 551 */ 552 struct lu_ref loh_reference; 553}; 554 555struct fld; 556 557struct lu_site_bkt_data { 558 /** 559 * number of busy object on this bucket 560 */ 561 long lsb_busy; 562 /** 563 * LRU list, updated on each access to object. Protected by 564 * bucket lock of lu_site::ls_obj_hash. 565 * 566 * "Cold" end of LRU is lu_site::ls_lru.next. Accessed object are 567 * moved to the lu_site::ls_lru.prev (this is due to the non-existence 568 * of list_for_each_entry_safe_reverse()). 569 */ 570 struct list_head lsb_lru; 571 /** 572 * Wait-queue signaled when an object in this site is ultimately 573 * destroyed (lu_object_free()). It is used by lu_object_find() to 574 * wait before re-trying when object in the process of destruction is 575 * found in the hash table. 576 * 577 * \see htable_lookup(). 578 */ 579 wait_queue_head_t lsb_marche_funebre; 580}; 581 582enum { 583 LU_SS_CREATED = 0, 584 LU_SS_CACHE_HIT, 585 LU_SS_CACHE_MISS, 586 LU_SS_CACHE_RACE, 587 LU_SS_CACHE_DEATH_RACE, 588 LU_SS_LRU_PURGED, 589 LU_SS_LAST_STAT 590}; 591 592/** 593 * lu_site is a "compartment" within which objects are unique, and LRU 594 * discipline is maintained. 595 * 596 * lu_site exists so that multiple layered stacks can co-exist in the same 597 * address space. 598 * 599 * lu_site has the same relation to lu_device as lu_object_header to 600 * lu_object. 601 */ 602struct lu_site { 603 /** 604 * objects hash table 605 */ 606 struct cfs_hash *ls_obj_hash; 607 /** 608 * index of bucket on hash table while purging 609 */ 610 int ls_purge_start; 611 /** 612 * Top-level device for this stack. 613 */ 614 struct lu_device *ls_top_dev; 615 /** 616 * Bottom-level device for this stack 617 */ 618 struct lu_device *ls_bottom_dev; 619 /** 620 * Linkage into global list of sites. 621 */ 622 struct list_head ls_linkage; 623 /** 624 * List for lu device for this site, protected 625 * by ls_ld_lock. 626 **/ 627 struct list_head ls_ld_linkage; 628 spinlock_t ls_ld_lock; 629 630 /** 631 * lu_site stats 632 */ 633 struct lprocfs_stats *ls_stats; 634 /** 635 * XXX: a hack! fld has to find md_site via site, remove when possible 636 */ 637 struct seq_server_site *ld_seq_site; 638}; 639 640static inline struct lu_site_bkt_data * 641lu_site_bkt_from_fid(struct lu_site *site, struct lu_fid *fid) 642{ 643 struct cfs_hash_bd bd; 644 645 cfs_hash_bd_get(site->ls_obj_hash, fid, &bd); 646 return cfs_hash_bd_extra_get(site->ls_obj_hash, &bd); 647} 648 649static inline struct seq_server_site *lu_site2seq(const struct lu_site *s) 650{ 651 return s->ld_seq_site; 652} 653 654/** \name ctors 655 * Constructors/destructors. 656 * @{ 657 */ 658 659int lu_site_init (struct lu_site *s, struct lu_device *d); 660void lu_site_fini (struct lu_site *s); 661int lu_site_init_finish (struct lu_site *s); 662void lu_stack_fini (const struct lu_env *env, struct lu_device *top); 663void lu_device_get (struct lu_device *d); 664void lu_device_put (struct lu_device *d); 665int lu_device_init (struct lu_device *d, struct lu_device_type *t); 666void lu_device_fini (struct lu_device *d); 667int lu_object_header_init(struct lu_object_header *h); 668void lu_object_header_fini(struct lu_object_header *h); 669int lu_object_init (struct lu_object *o, 670 struct lu_object_header *h, struct lu_device *d); 671void lu_object_fini (struct lu_object *o); 672void lu_object_add_top (struct lu_object_header *h, struct lu_object *o); 673void lu_object_add (struct lu_object *before, struct lu_object *o); 674 675void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d); 676void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d); 677 678/** 679 * Helpers to initialize and finalize device types. 680 */ 681 682int lu_device_type_init(struct lu_device_type *ldt); 683void lu_device_type_fini(struct lu_device_type *ldt); 684void lu_types_stop(void); 685 686/** @} ctors */ 687 688/** \name caching 689 * Caching and reference counting. 690 * @{ 691 */ 692 693/** 694 * Acquire additional reference to the given object. This function is used to 695 * attain additional reference. To acquire initial reference use 696 * lu_object_find(). 697 */ 698static inline void lu_object_get(struct lu_object *o) 699{ 700 LASSERT(atomic_read(&o->lo_header->loh_ref) > 0); 701 atomic_inc(&o->lo_header->loh_ref); 702} 703 704/** 705 * Return true of object will not be cached after last reference to it is 706 * released. 707 */ 708static inline int lu_object_is_dying(const struct lu_object_header *h) 709{ 710 return test_bit(LU_OBJECT_HEARD_BANSHEE, &h->loh_flags); 711} 712 713void lu_object_put(const struct lu_env *env, struct lu_object *o); 714void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o); 715void lu_object_unhash(const struct lu_env *env, struct lu_object *o); 716 717int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr); 718 719void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie, 720 lu_printer_t printer); 721struct lu_object *lu_object_find(const struct lu_env *env, 722 struct lu_device *dev, const struct lu_fid *f, 723 const struct lu_object_conf *conf); 724struct lu_object *lu_object_find_at(const struct lu_env *env, 725 struct lu_device *dev, 726 const struct lu_fid *f, 727 const struct lu_object_conf *conf); 728struct lu_object *lu_object_find_slice(const struct lu_env *env, 729 struct lu_device *dev, 730 const struct lu_fid *f, 731 const struct lu_object_conf *conf); 732/** @} caching */ 733 734/** \name helpers 735 * Helpers. 736 * @{ 737 */ 738 739/** 740 * First (topmost) sub-object of given compound object 741 */ 742static inline struct lu_object *lu_object_top(struct lu_object_header *h) 743{ 744 LASSERT(!list_empty(&h->loh_layers)); 745 return container_of0(h->loh_layers.next, struct lu_object, lo_linkage); 746} 747 748/** 749 * Next sub-object in the layering 750 */ 751static inline struct lu_object *lu_object_next(const struct lu_object *o) 752{ 753 return container_of0(o->lo_linkage.next, struct lu_object, lo_linkage); 754} 755 756/** 757 * Pointer to the fid of this object. 758 */ 759static inline const struct lu_fid *lu_object_fid(const struct lu_object *o) 760{ 761 return &o->lo_header->loh_fid; 762} 763 764/** 765 * return device operations vector for this object 766 */ 767static const inline struct lu_device_operations * 768lu_object_ops(const struct lu_object *o) 769{ 770 return o->lo_dev->ld_ops; 771} 772 773/** 774 * Given a compound object, find its slice, corresponding to the device type 775 * \a dtype. 776 */ 777struct lu_object *lu_object_locate(struct lu_object_header *h, 778 const struct lu_device_type *dtype); 779 780/** 781 * Printer function emitting messages through libcfs_debug_msg(). 782 */ 783int lu_cdebug_printer(const struct lu_env *env, 784 void *cookie, const char *format, ...); 785 786/** 787 * Print object description followed by a user-supplied message. 788 */ 789#define LU_OBJECT_DEBUG(mask, env, object, format, ...) \ 790do { \ 791 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \ 792 \ 793 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \ 794 lu_object_print(env, &msgdata, lu_cdebug_printer, object);\ 795 CDEBUG(mask, format , ## __VA_ARGS__); \ 796 } \ 797} while (0) 798 799/** 800 * Print short object description followed by a user-supplied message. 801 */ 802#define LU_OBJECT_HEADER(mask, env, object, format, ...) \ 803do { \ 804 LIBCFS_DEBUG_MSG_DATA_DECL(msgdata, mask, NULL); \ 805 \ 806 if (cfs_cdebug_show(mask, DEBUG_SUBSYSTEM)) { \ 807 lu_object_header_print(env, &msgdata, lu_cdebug_printer,\ 808 (object)->lo_header); \ 809 lu_cdebug_printer(env, &msgdata, "\n"); \ 810 CDEBUG(mask, format , ## __VA_ARGS__); \ 811 } \ 812} while (0) 813 814void lu_object_print (const struct lu_env *env, void *cookie, 815 lu_printer_t printer, const struct lu_object *o); 816void lu_object_header_print(const struct lu_env *env, void *cookie, 817 lu_printer_t printer, 818 const struct lu_object_header *hdr); 819 820/** 821 * Check object consistency. 822 */ 823int lu_object_invariant(const struct lu_object *o); 824 825 826/** 827 * Check whether object exists, no matter on local or remote storage. 828 * Note: LOHA_EXISTS will be set once some one created the object, 829 * and it does not needs to be committed to storage. 830 */ 831#define lu_object_exists(o) ((o)->lo_header->loh_attr & LOHA_EXISTS) 832 833/** 834 * Check whether object on the remote storage. 835 */ 836#define lu_object_remote(o) unlikely((o)->lo_header->loh_attr & LOHA_REMOTE) 837 838static inline int lu_object_assert_exists(const struct lu_object *o) 839{ 840 return lu_object_exists(o); 841} 842 843static inline int lu_object_assert_not_exists(const struct lu_object *o) 844{ 845 return !lu_object_exists(o); 846} 847 848/** 849 * Attr of this object. 850 */ 851static inline __u32 lu_object_attr(const struct lu_object *o) 852{ 853 LASSERT(lu_object_exists(o) != 0); 854 return o->lo_header->loh_attr; 855} 856 857static inline void lu_object_ref_add(struct lu_object *o, 858 const char *scope, 859 const void *source) 860{ 861 lu_ref_add(&o->lo_header->loh_reference, scope, source); 862} 863 864static inline void lu_object_ref_add_at(struct lu_object *o, 865 struct lu_ref_link *link, 866 const char *scope, 867 const void *source) 868{ 869 lu_ref_add_at(&o->lo_header->loh_reference, link, scope, source); 870} 871 872static inline void lu_object_ref_del(struct lu_object *o, 873 const char *scope, const void *source) 874{ 875 lu_ref_del(&o->lo_header->loh_reference, scope, source); 876} 877 878static inline void lu_object_ref_del_at(struct lu_object *o, 879 struct lu_ref_link *link, 880 const char *scope, const void *source) 881{ 882 lu_ref_del_at(&o->lo_header->loh_reference, link, scope, source); 883} 884 885/** input params, should be filled out by mdt */ 886struct lu_rdpg { 887 /** hash */ 888 __u64 rp_hash; 889 /** count in bytes */ 890 unsigned int rp_count; 891 /** number of pages */ 892 unsigned int rp_npages; 893 /** requested attr */ 894 __u32 rp_attrs; 895 /** pointers to pages */ 896 struct page **rp_pages; 897}; 898 899enum lu_xattr_flags { 900 LU_XATTR_REPLACE = (1 << 0), 901 LU_XATTR_CREATE = (1 << 1) 902}; 903 904/** @} helpers */ 905 906/** \name lu_context 907 * @{ */ 908 909/** For lu_context health-checks */ 910enum lu_context_state { 911 LCS_INITIALIZED = 1, 912 LCS_ENTERED, 913 LCS_LEFT, 914 LCS_FINALIZED 915}; 916 917/** 918 * lu_context. Execution context for lu_object methods. Currently associated 919 * with thread. 920 * 921 * All lu_object methods, except device and device type methods (called during 922 * system initialization and shutdown) are executed "within" some 923 * lu_context. This means, that pointer to some "current" lu_context is passed 924 * as an argument to all methods. 925 * 926 * All service ptlrpc threads create lu_context as part of their 927 * initialization. It is possible to create "stand-alone" context for other 928 * execution environments (like system calls). 929 * 930 * lu_object methods mainly use lu_context through lu_context_key interface 931 * that allows each layer to associate arbitrary pieces of data with each 932 * context (see pthread_key_create(3) for similar interface). 933 * 934 * On a client, lu_context is bound to a thread, see cl_env_get(). 935 * 936 * \see lu_context_key 937 */ 938struct lu_context { 939 /** 940 * lu_context is used on the client side too. Yet we don't want to 941 * allocate values of server-side keys for the client contexts and 942 * vice versa. 943 * 944 * To achieve this, set of tags in introduced. Contexts and keys are 945 * marked with tags. Key value are created only for context whose set 946 * of tags has non-empty intersection with one for key. Tags are taken 947 * from enum lu_context_tag. 948 */ 949 __u32 lc_tags; 950 enum lu_context_state lc_state; 951 /** 952 * Pointer to the home service thread. NULL for other execution 953 * contexts. 954 */ 955 struct ptlrpc_thread *lc_thread; 956 /** 957 * Pointer to an array with key values. Internal implementation 958 * detail. 959 */ 960 void **lc_value; 961 /** 962 * Linkage into a list of all remembered contexts. Only 963 * `non-transient' contexts, i.e., ones created for service threads 964 * are placed here. 965 */ 966 struct list_head lc_remember; 967 /** 968 * Version counter used to skip calls to lu_context_refill() when no 969 * keys were registered. 970 */ 971 unsigned lc_version; 972 /** 973 * Debugging cookie. 974 */ 975 unsigned lc_cookie; 976}; 977 978/** 979 * lu_context_key interface. Similar to pthread_key. 980 */ 981 982enum lu_context_tag { 983 /** 984 * Thread on md server 985 */ 986 LCT_MD_THREAD = 1 << 0, 987 /** 988 * Thread on dt server 989 */ 990 LCT_DT_THREAD = 1 << 1, 991 /** 992 * Context for transaction handle 993 */ 994 LCT_TX_HANDLE = 1 << 2, 995 /** 996 * Thread on client 997 */ 998 LCT_CL_THREAD = 1 << 3, 999 /** 1000 * A per-request session on a server, and a per-system-call session on 1001 * a client. 1002 */ 1003 LCT_SESSION = 1 << 4, 1004 /** 1005 * A per-request data on OSP device 1006 */ 1007 LCT_OSP_THREAD = 1 << 5, 1008 /** 1009 * MGS device thread 1010 */ 1011 LCT_MG_THREAD = 1 << 6, 1012 /** 1013 * Context for local operations 1014 */ 1015 LCT_LOCAL = 1 << 7, 1016 /** 1017 * Set when at least one of keys, having values in this context has 1018 * non-NULL lu_context_key::lct_exit() method. This is used to 1019 * optimize lu_context_exit() call. 1020 */ 1021 LCT_HAS_EXIT = 1 << 28, 1022 /** 1023 * Don't add references for modules creating key values in that context. 1024 * This is only for contexts used internally by lu_object framework. 1025 */ 1026 LCT_NOREF = 1 << 29, 1027 /** 1028 * Key is being prepared for retiring, don't create new values for it. 1029 */ 1030 LCT_QUIESCENT = 1 << 30, 1031 /** 1032 * Context should be remembered. 1033 */ 1034 LCT_REMEMBER = 1 << 31, 1035 /** 1036 * Contexts usable in cache shrinker thread. 1037 */ 1038 LCT_SHRINKER = LCT_MD_THREAD|LCT_DT_THREAD|LCT_CL_THREAD|LCT_NOREF 1039}; 1040 1041/** 1042 * Key. Represents per-context value slot. 1043 * 1044 * Keys are usually registered when module owning the key is initialized, and 1045 * de-registered when module is unloaded. Once key is registered, all new 1046 * contexts with matching tags, will get key value. "Old" contexts, already 1047 * initialized at the time of key registration, can be forced to get key value 1048 * by calling lu_context_refill(). 1049 * 1050 * Every key value is counted in lu_context_key::lct_used and acquires a 1051 * reference on an owning module. This means, that all key values have to be 1052 * destroyed before module can be unloaded. This is usually achieved by 1053 * stopping threads started by the module, that created contexts in their 1054 * entry functions. Situation is complicated by the threads shared by multiple 1055 * modules, like ptlrpcd daemon on a client. To work around this problem, 1056 * contexts, created in such threads, are `remembered' (see 1057 * LCT_REMEMBER)---i.e., added into a global list. When module is preparing 1058 * for unloading it does the following: 1059 * 1060 * - marks its keys as `quiescent' (lu_context_tag::LCT_QUIESCENT) 1061 * preventing new key values from being allocated in the new contexts, 1062 * and 1063 * 1064 * - scans a list of remembered contexts, destroying values of module 1065 * keys, thus releasing references to the module. 1066 * 1067 * This is done by lu_context_key_quiesce(). If module is re-activated 1068 * before key has been de-registered, lu_context_key_revive() call clears 1069 * `quiescent' marker. 1070 * 1071 * lu_context code doesn't provide any internal synchronization for these 1072 * activities---it's assumed that startup (including threads start-up) and 1073 * shutdown are serialized by some external means. 1074 * 1075 * \see lu_context 1076 */ 1077struct lu_context_key { 1078 /** 1079 * Set of tags for which values of this key are to be instantiated. 1080 */ 1081 __u32 lct_tags; 1082 /** 1083 * Value constructor. This is called when new value is created for a 1084 * context. Returns pointer to new value of error pointer. 1085 */ 1086 void *(*lct_init)(const struct lu_context *ctx, 1087 struct lu_context_key *key); 1088 /** 1089 * Value destructor. Called when context with previously allocated 1090 * value of this slot is destroyed. \a data is a value that was returned 1091 * by a matching call to lu_context_key::lct_init(). 1092 */ 1093 void (*lct_fini)(const struct lu_context *ctx, 1094 struct lu_context_key *key, void *data); 1095 /** 1096 * Optional method called on lu_context_exit() for all allocated 1097 * keys. Can be used by debugging code checking that locks are 1098 * released, etc. 1099 */ 1100 void (*lct_exit)(const struct lu_context *ctx, 1101 struct lu_context_key *key, void *data); 1102 /** 1103 * Internal implementation detail: index within lu_context::lc_value[] 1104 * reserved for this key. 1105 */ 1106 int lct_index; 1107 /** 1108 * Internal implementation detail: number of values created for this 1109 * key. 1110 */ 1111 atomic_t lct_used; 1112 /** 1113 * Internal implementation detail: module for this key. 1114 */ 1115 struct module *lct_owner; 1116 /** 1117 * References to this key. For debugging. 1118 */ 1119 struct lu_ref lct_reference; 1120}; 1121 1122#define LU_KEY_INIT(mod, type) \ 1123 static void* mod##_key_init(const struct lu_context *ctx, \ 1124 struct lu_context_key *key) \ 1125 { \ 1126 type *value; \ 1127 \ 1128 CLASSERT(PAGE_CACHE_SIZE >= sizeof (*value)); \ 1129 \ 1130 OBD_ALLOC_PTR(value); \ 1131 if (value == NULL) \ 1132 value = ERR_PTR(-ENOMEM); \ 1133 \ 1134 return value; \ 1135 } \ 1136 struct __##mod##__dummy_init {;} /* semicolon catcher */ 1137 1138#define LU_KEY_FINI(mod, type) \ 1139 static void mod##_key_fini(const struct lu_context *ctx, \ 1140 struct lu_context_key *key, void* data) \ 1141 { \ 1142 type *info = data; \ 1143 \ 1144 OBD_FREE_PTR(info); \ 1145 } \ 1146 struct __##mod##__dummy_fini {;} /* semicolon catcher */ 1147 1148#define LU_KEY_INIT_FINI(mod, type) \ 1149 LU_KEY_INIT(mod, type); \ 1150 LU_KEY_FINI(mod, type) 1151 1152#define LU_CONTEXT_KEY_DEFINE(mod, tags) \ 1153 struct lu_context_key mod##_thread_key = { \ 1154 .lct_tags = tags, \ 1155 .lct_init = mod##_key_init, \ 1156 .lct_fini = mod##_key_fini \ 1157 } 1158 1159#define LU_CONTEXT_KEY_INIT(key) \ 1160do { \ 1161 (key)->lct_owner = THIS_MODULE; \ 1162} while (0) 1163 1164int lu_context_key_register(struct lu_context_key *key); 1165void lu_context_key_degister(struct lu_context_key *key); 1166void *lu_context_key_get (const struct lu_context *ctx, 1167 const struct lu_context_key *key); 1168void lu_context_key_quiesce (struct lu_context_key *key); 1169void lu_context_key_revive (struct lu_context_key *key); 1170 1171 1172/* 1173 * LU_KEY_INIT_GENERIC() has to be a macro to correctly determine an 1174 * owning module. 1175 */ 1176 1177#define LU_KEY_INIT_GENERIC(mod) \ 1178 static void mod##_key_init_generic(struct lu_context_key *k, ...) \ 1179 { \ 1180 struct lu_context_key *key = k; \ 1181 va_list args; \ 1182 \ 1183 va_start(args, k); \ 1184 do { \ 1185 LU_CONTEXT_KEY_INIT(key); \ 1186 key = va_arg(args, struct lu_context_key *); \ 1187 } while (key != NULL); \ 1188 va_end(args); \ 1189 } 1190 1191#define LU_TYPE_INIT(mod, ...) \ 1192 LU_KEY_INIT_GENERIC(mod) \ 1193 static int mod##_type_init(struct lu_device_type *t) \ 1194 { \ 1195 mod##_key_init_generic(__VA_ARGS__, NULL); \ 1196 return lu_context_key_register_many(__VA_ARGS__, NULL); \ 1197 } \ 1198 struct __##mod##_dummy_type_init {;} 1199 1200#define LU_TYPE_FINI(mod, ...) \ 1201 static void mod##_type_fini(struct lu_device_type *t) \ 1202 { \ 1203 lu_context_key_degister_many(__VA_ARGS__, NULL); \ 1204 } \ 1205 struct __##mod##_dummy_type_fini {;} 1206 1207#define LU_TYPE_START(mod, ...) \ 1208 static void mod##_type_start(struct lu_device_type *t) \ 1209 { \ 1210 lu_context_key_revive_many(__VA_ARGS__, NULL); \ 1211 } \ 1212 struct __##mod##_dummy_type_start {;} 1213 1214#define LU_TYPE_STOP(mod, ...) \ 1215 static void mod##_type_stop(struct lu_device_type *t) \ 1216 { \ 1217 lu_context_key_quiesce_many(__VA_ARGS__, NULL); \ 1218 } \ 1219 struct __##mod##_dummy_type_stop {;} 1220 1221 1222 1223#define LU_TYPE_INIT_FINI(mod, ...) \ 1224 LU_TYPE_INIT(mod, __VA_ARGS__); \ 1225 LU_TYPE_FINI(mod, __VA_ARGS__); \ 1226 LU_TYPE_START(mod, __VA_ARGS__); \ 1227 LU_TYPE_STOP(mod, __VA_ARGS__) 1228 1229int lu_context_init (struct lu_context *ctx, __u32 tags); 1230void lu_context_fini (struct lu_context *ctx); 1231void lu_context_enter (struct lu_context *ctx); 1232void lu_context_exit (struct lu_context *ctx); 1233int lu_context_refill(struct lu_context *ctx); 1234 1235/* 1236 * Helper functions to operate on multiple keys. These are used by the default 1237 * device type operations, defined by LU_TYPE_INIT_FINI(). 1238 */ 1239 1240int lu_context_key_register_many(struct lu_context_key *k, ...); 1241void lu_context_key_degister_many(struct lu_context_key *k, ...); 1242void lu_context_key_revive_many (struct lu_context_key *k, ...); 1243void lu_context_key_quiesce_many (struct lu_context_key *k, ...); 1244 1245/* 1246 * update/clear ctx/ses tags. 1247 */ 1248void lu_context_tags_update(__u32 tags); 1249void lu_context_tags_clear(__u32 tags); 1250void lu_session_tags_update(__u32 tags); 1251void lu_session_tags_clear(__u32 tags); 1252 1253/** 1254 * Environment. 1255 */ 1256struct lu_env { 1257 /** 1258 * "Local" context, used to store data instead of stack. 1259 */ 1260 struct lu_context le_ctx; 1261 /** 1262 * "Session" context for per-request data. 1263 */ 1264 struct lu_context *le_ses; 1265}; 1266 1267int lu_env_init (struct lu_env *env, __u32 tags); 1268void lu_env_fini (struct lu_env *env); 1269int lu_env_refill(struct lu_env *env); 1270int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags, __u32 stags); 1271 1272/** @} lu_context */ 1273 1274/** 1275 * Output site statistical counters into a buffer. Suitable for 1276 * ll_rd_*()-style functions. 1277 */ 1278int lu_site_stats_print(const struct lu_site *s, struct seq_file *m); 1279 1280/** 1281 * Common name structure to be passed around for various name related methods. 1282 */ 1283struct lu_name { 1284 const char *ln_name; 1285 int ln_namelen; 1286}; 1287 1288/** 1289 * Common buffer structure to be passed around for various xattr_{s,g}et() 1290 * methods. 1291 */ 1292struct lu_buf { 1293 void *lb_buf; 1294 ssize_t lb_len; 1295}; 1296 1297#define DLUBUF "(%p %zu)" 1298#define PLUBUF(buf) (buf)->lb_buf, (buf)->lb_len 1299/** 1300 * One-time initializers, called at obdclass module initialization, not 1301 * exported. 1302 */ 1303 1304/** 1305 * Initialization of global lu_* data. 1306 */ 1307int lu_global_init(void); 1308 1309/** 1310 * Dual to lu_global_init(). 1311 */ 1312void lu_global_fini(void); 1313 1314struct lu_kmem_descr { 1315 struct kmem_cache **ckd_cache; 1316 const char *ckd_name; 1317 const size_t ckd_size; 1318}; 1319 1320int lu_kmem_init(struct lu_kmem_descr *caches); 1321void lu_kmem_fini(struct lu_kmem_descr *caches); 1322 1323void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o, 1324 const struct lu_fid *fid); 1325struct lu_object *lu_object_anon(const struct lu_env *env, 1326 struct lu_device *dev, 1327 const struct lu_object_conf *conf); 1328 1329/** null buffer */ 1330extern struct lu_buf LU_BUF_NULL; 1331 1332void lu_buf_free(struct lu_buf *buf); 1333void lu_buf_alloc(struct lu_buf *buf, int size); 1334void lu_buf_realloc(struct lu_buf *buf, int size); 1335 1336int lu_buf_check_and_grow(struct lu_buf *buf, int len); 1337struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len); 1338 1339/** @} lu */ 1340#endif /* __LUSTRE_LU_OBJECT_H */ 1341