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, 2012, Intel Corporation.
33 * This file is part of Lustre, http://www.lustre.org/
34 * Lustre is a trademark of Sun Microsystems, Inc.
36 * lustre/obdclass/lu_object.c
39 * These are the only exported functions, they provide some generic
40 * infrastructure for managing object devices
42 * Author: Nikita Danilov <nikita.danilov@sun.com>
45 #define DEBUG_SUBSYSTEM S_CLASS
47 #include "../../include/linux/libcfs/libcfs.h"
49 # include <linux/module.h>
52 #include "../../include/linux/libcfs/libcfs_hash.h"
53 #include "../include/obd_class.h"
54 #include "../include/obd_support.h"
55 #include "../include/lustre_disk.h"
56 #include "../include/lustre_fid.h"
57 #include "../include/lu_object.h"
58 #include "../include/lu_ref.h"
59 #include <linux/list.h>
61 static void lu_object_free(const struct lu_env *env, struct lu_object *o);
64 * Decrease reference counter on object. If last reference is freed, return
65 * object to the cache, unless lu_object_is_dying(o) holds. In the latter
66 * case, free object immediately.
68 void lu_object_put(const struct lu_env *env, struct lu_object *o)
70 struct lu_site_bkt_data *bkt;
71 struct lu_object_header *top;
73 struct lu_object *orig;
74 struct cfs_hash_bd bd;
75 const struct lu_fid *fid;
78 site = o->lo_dev->ld_site;
82 * till we have full fids-on-OST implemented anonymous objects
83 * are possible in OSP. such an object isn't listed in the site
84 * so we should not remove it from the site.
86 fid = lu_object_fid(o);
87 if (fid_is_zero(fid)) {
88 LASSERT(top->loh_hash.next == NULL
89 && top->loh_hash.pprev == NULL);
90 LASSERT(list_empty(&top->loh_lru));
91 if (!atomic_dec_and_test(&top->loh_ref))
93 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
94 if (o->lo_ops->loo_object_release != NULL)
95 o->lo_ops->loo_object_release(env, o);
97 lu_object_free(env, orig);
101 cfs_hash_bd_get(site->ls_obj_hash, &top->loh_fid, &bd);
102 bkt = cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
104 if (!cfs_hash_bd_dec_and_lock(site->ls_obj_hash, &bd, &top->loh_ref)) {
105 if (lu_object_is_dying(top)) {
108 * somebody may be waiting for this, currently only
109 * used for cl_object, see cl_object_put_last().
111 wake_up_all(&bkt->lsb_marche_funebre);
116 LASSERT(bkt->lsb_busy > 0);
119 * When last reference is released, iterate over object
120 * layers, and notify them that object is no longer busy.
122 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
123 if (o->lo_ops->loo_object_release != NULL)
124 o->lo_ops->loo_object_release(env, o);
127 if (!lu_object_is_dying(top)) {
128 LASSERT(list_empty(&top->loh_lru));
129 list_add_tail(&top->loh_lru, &bkt->lsb_lru);
130 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
135 * If object is dying (will not be cached), removed it
136 * from hash table and LRU.
138 * This is done with hash table and LRU lists locked. As the only
139 * way to acquire first reference to previously unreferenced
140 * object is through hash-table lookup (lu_object_find()),
141 * or LRU scanning (lu_site_purge()), that are done under hash-table
142 * and LRU lock, no race with concurrent object lookup is possible
143 * and we can safely destroy object below.
145 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags))
146 cfs_hash_bd_del_locked(site->ls_obj_hash, &bd, &top->loh_hash);
147 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
149 * Object was already removed from hash and lru above, can
152 lu_object_free(env, orig);
154 EXPORT_SYMBOL(lu_object_put);
157 * Put object and don't keep in cache. This is temporary solution for
158 * multi-site objects when its layering is not constant.
160 void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o)
162 set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags);
163 return lu_object_put(env, o);
165 EXPORT_SYMBOL(lu_object_put_nocache);
168 * Kill the object and take it out of LRU cache.
169 * Currently used by client code for layout change.
171 void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
173 struct lu_object_header *top;
176 set_bit(LU_OBJECT_HEARD_BANSHEE, &top->loh_flags);
177 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) {
178 struct cfs_hash *obj_hash = o->lo_dev->ld_site->ls_obj_hash;
179 struct cfs_hash_bd bd;
181 cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1);
182 list_del_init(&top->loh_lru);
183 cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
184 cfs_hash_bd_unlock(obj_hash, &bd, 1);
187 EXPORT_SYMBOL(lu_object_unhash);
190 * Allocate new object.
192 * This follows object creation protocol, described in the comment within
193 * struct lu_device_operations definition.
195 static struct lu_object *lu_object_alloc(const struct lu_env *env,
196 struct lu_device *dev,
197 const struct lu_fid *f,
198 const struct lu_object_conf *conf)
200 struct lu_object *scan;
201 struct lu_object *top;
202 struct list_head *layers;
203 unsigned int init_mask = 0;
204 unsigned int init_flag;
209 * Create top-level object slice. This will also create
212 top = dev->ld_ops->ldo_object_alloc(env, NULL, dev);
214 return ERR_PTR(-ENOMEM);
218 * This is the only place where object fid is assigned. It's constant
221 top->lo_header->loh_fid = *f;
222 layers = &top->lo_header->loh_layers;
226 * Call ->loo_object_init() repeatedly, until no more new
227 * object slices are created.
231 list_for_each_entry(scan, layers, lo_linkage) {
232 if (init_mask & init_flag)
235 scan->lo_header = top->lo_header;
236 result = scan->lo_ops->loo_object_init(env, scan, conf);
238 lu_object_free(env, top);
239 return ERR_PTR(result);
241 init_mask |= init_flag;
247 list_for_each_entry_reverse(scan, layers, lo_linkage) {
248 if (scan->lo_ops->loo_object_start != NULL) {
249 result = scan->lo_ops->loo_object_start(env, scan);
251 lu_object_free(env, top);
252 return ERR_PTR(result);
257 lprocfs_counter_incr(dev->ld_site->ls_stats, LU_SS_CREATED);
264 static void lu_object_free(const struct lu_env *env, struct lu_object *o)
266 struct lu_site_bkt_data *bkt;
267 struct lu_site *site;
268 struct lu_object *scan;
269 struct list_head *layers;
270 struct list_head splice;
272 site = o->lo_dev->ld_site;
273 layers = &o->lo_header->loh_layers;
274 bkt = lu_site_bkt_from_fid(site, &o->lo_header->loh_fid);
276 * First call ->loo_object_delete() method to release all resources.
278 list_for_each_entry_reverse(scan, layers, lo_linkage) {
279 if (scan->lo_ops->loo_object_delete != NULL)
280 scan->lo_ops->loo_object_delete(env, scan);
284 * Then, splice object layers into stand-alone list, and call
285 * ->loo_object_free() on all layers to free memory. Splice is
286 * necessary, because lu_object_header is freed together with the
289 INIT_LIST_HEAD(&splice);
290 list_splice_init(layers, &splice);
291 while (!list_empty(&splice)) {
293 * Free layers in bottom-to-top order, so that object header
294 * lives as long as possible and ->loo_object_free() methods
295 * can look at its contents.
297 o = container_of0(splice.prev, struct lu_object, lo_linkage);
298 list_del_init(&o->lo_linkage);
299 LASSERT(o->lo_ops->loo_object_free != NULL);
300 o->lo_ops->loo_object_free(env, o);
303 if (waitqueue_active(&bkt->lsb_marche_funebre))
304 wake_up_all(&bkt->lsb_marche_funebre);
308 * Free \a nr objects from the cold end of the site LRU list.
310 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
312 struct lu_object_header *h;
313 struct lu_object_header *temp;
314 struct lu_site_bkt_data *bkt;
315 struct cfs_hash_bd bd;
316 struct cfs_hash_bd bd2;
317 struct list_head dispose;
324 if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU))
327 INIT_LIST_HEAD(&dispose);
329 * Under LRU list lock, scan LRU list and move unreferenced objects to
330 * the dispose list, removing them from LRU and hash table.
332 start = s->ls_purge_start;
333 bnr = (nr == ~0) ? -1 : nr / CFS_HASH_NBKT(s->ls_obj_hash) + 1;
336 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
340 cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1);
341 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
343 list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) {
344 LASSERT(atomic_read(&h->loh_ref) == 0);
346 cfs_hash_bd_get(s->ls_obj_hash, &h->loh_fid, &bd2);
347 LASSERT(bd.bd_bucket == bd2.bd_bucket);
349 cfs_hash_bd_del_locked(s->ls_obj_hash,
351 list_move(&h->loh_lru, &dispose);
355 if (nr != ~0 && --nr == 0)
358 if (count > 0 && --count == 0)
362 cfs_hash_bd_unlock(s->ls_obj_hash, &bd, 1);
365 * Free everything on the dispose list. This is safe against
366 * races due to the reasons described in lu_object_put().
368 while (!list_empty(&dispose)) {
369 h = container_of0(dispose.next,
370 struct lu_object_header, loh_lru);
371 list_del_init(&h->loh_lru);
372 lu_object_free(env, lu_object_top(h));
373 lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED);
380 if (nr != 0 && did_sth && start != 0) {
381 start = 0; /* restart from the first bucket */
384 /* race on s->ls_purge_start, but nobody cares */
385 s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash);
389 EXPORT_SYMBOL(lu_site_purge);
394 * Code below has to jump through certain loops to output object description
395 * into libcfs_debug_msg-based log. The problem is that lu_object_print()
396 * composes object description from strings that are parts of _lines_ of
397 * output (i.e., strings that are not terminated by newline). This doesn't fit
398 * very well into libcfs_debug_msg() interface that assumes that each message
399 * supplied to it is a self-contained output line.
401 * To work around this, strings are collected in a temporary buffer
402 * (implemented as a value of lu_cdebug_key key), until terminating newline
403 * character is detected.
411 * XXX overflow is not handled correctly.
416 struct lu_cdebug_data {
420 char lck_area[LU_CDEBUG_LINE];
423 /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
424 LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data);
427 * Key, holding temporary buffer. This key is registered very early by
430 struct lu_context_key lu_global_key = {
431 .lct_tags = LCT_MD_THREAD | LCT_DT_THREAD |
432 LCT_MG_THREAD | LCT_CL_THREAD | LCT_LOCAL,
433 .lct_init = lu_global_key_init,
434 .lct_fini = lu_global_key_fini
438 * Printer function emitting messages through libcfs_debug_msg().
440 int lu_cdebug_printer(const struct lu_env *env,
441 void *cookie, const char *format, ...)
443 struct libcfs_debug_msg_data *msgdata = cookie;
444 struct lu_cdebug_data *key;
449 va_start(args, format);
451 key = lu_context_key_get(&env->le_ctx, &lu_global_key);
452 LASSERT(key != NULL);
454 used = strlen(key->lck_area);
455 complete = format[strlen(format) - 1] == '\n';
457 * Append new chunk to the buffer.
459 vsnprintf(key->lck_area + used,
460 ARRAY_SIZE(key->lck_area) - used, format, args);
462 if (cfs_cdebug_show(msgdata->msg_mask, msgdata->msg_subsys))
463 libcfs_debug_msg(msgdata, "%s", key->lck_area);
464 key->lck_area[0] = 0;
469 EXPORT_SYMBOL(lu_cdebug_printer);
472 * Print object header.
474 void lu_object_header_print(const struct lu_env *env, void *cookie,
475 lu_printer_t printer,
476 const struct lu_object_header *hdr)
478 (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
479 hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
481 hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
482 list_empty((struct list_head *)&hdr->loh_lru) ? \
484 hdr->loh_attr & LOHA_EXISTS ? " exist":"");
486 EXPORT_SYMBOL(lu_object_header_print);
489 * Print human readable representation of the \a o to the \a printer.
491 void lu_object_print(const struct lu_env *env, void *cookie,
492 lu_printer_t printer, const struct lu_object *o)
494 static const char ruler[] = "........................................";
495 struct lu_object_header *top;
499 lu_object_header_print(env, cookie, printer, top);
500 (*printer)(env, cookie, "{\n");
502 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
504 * print `.' \a depth times followed by type name and address
506 (*printer)(env, cookie, "%*.*s%s@%p", depth, depth, ruler,
507 o->lo_dev->ld_type->ldt_name, o);
509 if (o->lo_ops->loo_object_print != NULL)
510 (*o->lo_ops->loo_object_print)(env, cookie, printer, o);
512 (*printer)(env, cookie, "\n");
515 (*printer)(env, cookie, "} header@%p\n", top);
517 EXPORT_SYMBOL(lu_object_print);
520 * Check object consistency.
522 int lu_object_invariant(const struct lu_object *o)
524 struct lu_object_header *top;
527 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
528 if (o->lo_ops->loo_object_invariant != NULL &&
529 !o->lo_ops->loo_object_invariant(o))
534 EXPORT_SYMBOL(lu_object_invariant);
536 static struct lu_object *htable_lookup(struct lu_site *s,
537 struct cfs_hash_bd *bd,
538 const struct lu_fid *f,
539 wait_queue_t *waiter,
542 struct lu_site_bkt_data *bkt;
543 struct lu_object_header *h;
544 struct hlist_node *hnode;
545 __u64 ver = cfs_hash_bd_version_get(bd);
548 return ERR_PTR(-ENOENT);
551 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, bd);
552 /* cfs_hash_bd_peek_locked is a somehow "internal" function
553 * of cfs_hash, it doesn't add refcount on object. */
554 hnode = cfs_hash_bd_peek_locked(s->ls_obj_hash, bd, (void *)f);
556 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_MISS);
557 return ERR_PTR(-ENOENT);
560 h = container_of0(hnode, struct lu_object_header, loh_hash);
561 if (likely(!lu_object_is_dying(h))) {
562 cfs_hash_get(s->ls_obj_hash, hnode);
563 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT);
564 list_del_init(&h->loh_lru);
565 return lu_object_top(h);
569 * Lookup found an object being destroyed this object cannot be
570 * returned (to assure that references to dying objects are eventually
571 * drained), and moreover, lookup has to wait until object is freed.
574 init_waitqueue_entry(waiter, current);
575 add_wait_queue(&bkt->lsb_marche_funebre, waiter);
576 set_current_state(TASK_UNINTERRUPTIBLE);
577 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE);
578 return ERR_PTR(-EAGAIN);
582 * Search cache for an object with the fid \a f. If such object is found,
583 * return it. Otherwise, create new object, insert it into cache and return
584 * it. In any case, additional reference is acquired on the returned object.
586 struct lu_object *lu_object_find(const struct lu_env *env,
587 struct lu_device *dev, const struct lu_fid *f,
588 const struct lu_object_conf *conf)
590 return lu_object_find_at(env, dev->ld_site->ls_top_dev, f, conf);
592 EXPORT_SYMBOL(lu_object_find);
594 static struct lu_object *lu_object_new(const struct lu_env *env,
595 struct lu_device *dev,
596 const struct lu_fid *f,
597 const struct lu_object_conf *conf)
601 struct cfs_hash_bd bd;
602 struct lu_site_bkt_data *bkt;
604 o = lu_object_alloc(env, dev, f, conf);
605 if (unlikely(IS_ERR(o)))
608 hs = dev->ld_site->ls_obj_hash;
609 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
610 bkt = cfs_hash_bd_extra_get(hs, &bd);
611 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
613 cfs_hash_bd_unlock(hs, &bd, 1);
618 * Core logic of lu_object_find*() functions.
620 static struct lu_object *lu_object_find_try(const struct lu_env *env,
621 struct lu_device *dev,
622 const struct lu_fid *f,
623 const struct lu_object_conf *conf,
624 wait_queue_t *waiter)
627 struct lu_object *shadow;
630 struct cfs_hash_bd bd;
634 * This uses standard index maintenance protocol:
636 * - search index under lock, and return object if found;
637 * - otherwise, unlock index, allocate new object;
638 * - lock index and search again;
639 * - if nothing is found (usual case), insert newly created
641 * - otherwise (race: other thread inserted object), free
642 * object just allocated.
646 * For "LOC_F_NEW" case, we are sure the object is new established.
647 * It is unnecessary to perform lookup-alloc-lookup-insert, instead,
648 * just alloc and insert directly.
650 * If dying object is found during index search, add @waiter to the
651 * site wait-queue and return ERR_PTR(-EAGAIN).
653 if (conf != NULL && conf->loc_flags & LOC_F_NEW)
654 return lu_object_new(env, dev, f, conf);
658 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
659 o = htable_lookup(s, &bd, f, waiter, &version);
660 cfs_hash_bd_unlock(hs, &bd, 1);
661 if (!IS_ERR(o) || PTR_ERR(o) != -ENOENT)
665 * Allocate new object. This may result in rather complicated
666 * operations, including fld queries, inode loading, etc.
668 o = lu_object_alloc(env, dev, f, conf);
669 if (unlikely(IS_ERR(o)))
672 LASSERT(lu_fid_eq(lu_object_fid(o), f));
674 cfs_hash_bd_lock(hs, &bd, 1);
676 shadow = htable_lookup(s, &bd, f, waiter, &version);
677 if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) {
678 struct lu_site_bkt_data *bkt;
680 bkt = cfs_hash_bd_extra_get(hs, &bd);
681 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
683 cfs_hash_bd_unlock(hs, &bd, 1);
687 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_RACE);
688 cfs_hash_bd_unlock(hs, &bd, 1);
689 lu_object_free(env, o);
694 * Much like lu_object_find(), but top level device of object is specifically
695 * \a dev rather than top level device of the site. This interface allows
696 * objects of different "stacking" to be created within the same site.
698 struct lu_object *lu_object_find_at(const struct lu_env *env,
699 struct lu_device *dev,
700 const struct lu_fid *f,
701 const struct lu_object_conf *conf)
703 struct lu_site_bkt_data *bkt;
704 struct lu_object *obj;
708 obj = lu_object_find_try(env, dev, f, conf, &wait);
709 if (obj != ERR_PTR(-EAGAIN))
712 * lu_object_find_try() already added waiter into the
716 bkt = lu_site_bkt_from_fid(dev->ld_site, (void *)f);
717 remove_wait_queue(&bkt->lsb_marche_funebre, &wait);
720 EXPORT_SYMBOL(lu_object_find_at);
723 * Find object with given fid, and return its slice belonging to given device.
725 struct lu_object *lu_object_find_slice(const struct lu_env *env,
726 struct lu_device *dev,
727 const struct lu_fid *f,
728 const struct lu_object_conf *conf)
730 struct lu_object *top;
731 struct lu_object *obj;
733 top = lu_object_find(env, dev, f, conf);
735 obj = lu_object_locate(top->lo_header, dev->ld_type);
737 lu_object_put(env, top);
742 EXPORT_SYMBOL(lu_object_find_slice);
745 * Global list of all device types.
747 static LIST_HEAD(lu_device_types);
749 int lu_device_type_init(struct lu_device_type *ldt)
753 INIT_LIST_HEAD(&ldt->ldt_linkage);
754 if (ldt->ldt_ops->ldto_init)
755 result = ldt->ldt_ops->ldto_init(ldt);
757 list_add(&ldt->ldt_linkage, &lu_device_types);
760 EXPORT_SYMBOL(lu_device_type_init);
762 void lu_device_type_fini(struct lu_device_type *ldt)
764 list_del_init(&ldt->ldt_linkage);
765 if (ldt->ldt_ops->ldto_fini)
766 ldt->ldt_ops->ldto_fini(ldt);
768 EXPORT_SYMBOL(lu_device_type_fini);
770 void lu_types_stop(void)
772 struct lu_device_type *ldt;
774 list_for_each_entry(ldt, &lu_device_types, ldt_linkage) {
775 if (ldt->ldt_device_nr == 0 && ldt->ldt_ops->ldto_stop)
776 ldt->ldt_ops->ldto_stop(ldt);
779 EXPORT_SYMBOL(lu_types_stop);
782 * Global list of all sites on this node
784 static LIST_HEAD(lu_sites);
785 static DEFINE_MUTEX(lu_sites_guard);
788 * Global environment used by site shrinker.
790 static struct lu_env lu_shrink_env;
792 struct lu_site_print_arg {
793 struct lu_env *lsp_env;
795 lu_printer_t lsp_printer;
799 lu_site_obj_print(struct cfs_hash *hs, struct cfs_hash_bd *bd,
800 struct hlist_node *hnode, void *data)
802 struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
803 struct lu_object_header *h;
805 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
806 if (!list_empty(&h->loh_layers)) {
807 const struct lu_object *o;
809 o = lu_object_top(h);
810 lu_object_print(arg->lsp_env, arg->lsp_cookie,
811 arg->lsp_printer, o);
813 lu_object_header_print(arg->lsp_env, arg->lsp_cookie,
814 arg->lsp_printer, h);
820 * Print all objects in \a s.
822 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
823 lu_printer_t printer)
825 struct lu_site_print_arg arg = {
826 .lsp_env = (struct lu_env *)env,
827 .lsp_cookie = cookie,
828 .lsp_printer = printer,
831 cfs_hash_for_each(s->ls_obj_hash, lu_site_obj_print, &arg);
833 EXPORT_SYMBOL(lu_site_print);
836 LU_CACHE_PERCENT_MAX = 50,
837 LU_CACHE_PERCENT_DEFAULT = 20
840 static unsigned int lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
841 module_param(lu_cache_percent, int, 0644);
842 MODULE_PARM_DESC(lu_cache_percent, "Percentage of memory to be used as lu_object cache");
845 * Return desired hash table order.
847 static int lu_htable_order(void)
849 unsigned long cache_size;
853 * Calculate hash table size, assuming that we want reasonable
854 * performance when 20% of total memory is occupied by cache of
857 * Size of lu_object is (arbitrary) taken as 1K (together with inode).
859 cache_size = totalram_pages;
861 #if BITS_PER_LONG == 32
862 /* limit hashtable size for lowmem systems to low RAM */
863 if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT))
864 cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4;
867 /* clear off unreasonable cache setting. */
868 if (lu_cache_percent == 0 || lu_cache_percent > LU_CACHE_PERCENT_MAX) {
869 CWARN("obdclass: invalid lu_cache_percent: %u, it must be in the range of (0, %u]. Will use default value: %u.\n",
870 lu_cache_percent, LU_CACHE_PERCENT_MAX,
871 LU_CACHE_PERCENT_DEFAULT);
873 lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
875 cache_size = cache_size / 100 * lu_cache_percent *
876 (PAGE_CACHE_SIZE / 1024);
878 for (bits = 1; (1 << bits) < cache_size; ++bits) {
884 static unsigned lu_obj_hop_hash(struct cfs_hash *hs,
885 const void *key, unsigned mask)
887 struct lu_fid *fid = (struct lu_fid *)key;
890 hash = fid_flatten32(fid);
891 hash += (hash >> 4) + (hash << 12); /* mixing oid and seq */
892 hash = hash_long(hash, hs->hs_bkt_bits);
894 /* give me another random factor */
895 hash -= hash_long((unsigned long)hs, fid_oid(fid) % 11 + 3);
897 hash <<= hs->hs_cur_bits - hs->hs_bkt_bits;
898 hash |= (fid_seq(fid) + fid_oid(fid)) & (CFS_HASH_NBKT(hs) - 1);
903 static void *lu_obj_hop_object(struct hlist_node *hnode)
905 return hlist_entry(hnode, struct lu_object_header, loh_hash);
908 static void *lu_obj_hop_key(struct hlist_node *hnode)
910 struct lu_object_header *h;
912 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
916 static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode)
918 struct lu_object_header *h;
920 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
921 return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key);
924 static void lu_obj_hop_get(struct cfs_hash *hs, struct hlist_node *hnode)
926 struct lu_object_header *h;
928 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
929 if (atomic_add_return(1, &h->loh_ref) == 1) {
930 struct lu_site_bkt_data *bkt;
931 struct cfs_hash_bd bd;
933 cfs_hash_bd_get(hs, &h->loh_fid, &bd);
934 bkt = cfs_hash_bd_extra_get(hs, &bd);
939 static void lu_obj_hop_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
941 LBUG(); /* we should never called it */
944 cfs_hash_ops_t lu_site_hash_ops = {
945 .hs_hash = lu_obj_hop_hash,
946 .hs_key = lu_obj_hop_key,
947 .hs_keycmp = lu_obj_hop_keycmp,
948 .hs_object = lu_obj_hop_object,
949 .hs_get = lu_obj_hop_get,
950 .hs_put_locked = lu_obj_hop_put_locked,
953 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d)
955 spin_lock(&s->ls_ld_lock);
956 if (list_empty(&d->ld_linkage))
957 list_add(&d->ld_linkage, &s->ls_ld_linkage);
958 spin_unlock(&s->ls_ld_lock);
960 EXPORT_SYMBOL(lu_dev_add_linkage);
962 void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d)
964 spin_lock(&s->ls_ld_lock);
965 list_del_init(&d->ld_linkage);
966 spin_unlock(&s->ls_ld_lock);
968 EXPORT_SYMBOL(lu_dev_del_linkage);
971 * Initialize site \a s, with \a d as the top level device.
973 #define LU_SITE_BITS_MIN 12
974 #define LU_SITE_BITS_MAX 24
976 * total 256 buckets, we don't want too many buckets because:
977 * - consume too much memory
978 * - avoid unbalanced LRU list
980 #define LU_SITE_BKT_BITS 8
982 int lu_site_init(struct lu_site *s, struct lu_device *top)
984 struct lu_site_bkt_data *bkt;
985 struct cfs_hash_bd bd;
990 memset(s, 0, sizeof(*s));
991 bits = lu_htable_order();
992 snprintf(name, 16, "lu_site_%s", top->ld_type->ldt_name);
993 for (bits = min(max(LU_SITE_BITS_MIN, bits), LU_SITE_BITS_MAX);
994 bits >= LU_SITE_BITS_MIN; bits--) {
995 s->ls_obj_hash = cfs_hash_create(name, bits, bits,
996 bits - LU_SITE_BKT_BITS,
999 CFS_HASH_SPIN_BKTLOCK |
1000 CFS_HASH_NO_ITEMREF |
1002 CFS_HASH_ASSERT_EMPTY);
1003 if (s->ls_obj_hash != NULL)
1007 if (s->ls_obj_hash == NULL) {
1008 CERROR("failed to create lu_site hash with bits: %d\n", bits);
1012 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
1013 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
1014 INIT_LIST_HEAD(&bkt->lsb_lru);
1015 init_waitqueue_head(&bkt->lsb_marche_funebre);
1018 s->ls_stats = lprocfs_alloc_stats(LU_SS_LAST_STAT, 0);
1019 if (s->ls_stats == NULL) {
1020 cfs_hash_putref(s->ls_obj_hash);
1021 s->ls_obj_hash = NULL;
1025 lprocfs_counter_init(s->ls_stats, LU_SS_CREATED,
1026 0, "created", "created");
1027 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_HIT,
1028 0, "cache_hit", "cache_hit");
1029 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_MISS,
1030 0, "cache_miss", "cache_miss");
1031 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_RACE,
1032 0, "cache_race", "cache_race");
1033 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_DEATH_RACE,
1034 0, "cache_death_race", "cache_death_race");
1035 lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
1036 0, "lru_purged", "lru_purged");
1038 INIT_LIST_HEAD(&s->ls_linkage);
1039 s->ls_top_dev = top;
1042 lu_ref_add(&top->ld_reference, "site-top", s);
1044 INIT_LIST_HEAD(&s->ls_ld_linkage);
1045 spin_lock_init(&s->ls_ld_lock);
1047 lu_dev_add_linkage(s, top);
1051 EXPORT_SYMBOL(lu_site_init);
1054 * Finalize \a s and release its resources.
1056 void lu_site_fini(struct lu_site *s)
1058 mutex_lock(&lu_sites_guard);
1059 list_del_init(&s->ls_linkage);
1060 mutex_unlock(&lu_sites_guard);
1062 if (s->ls_obj_hash != NULL) {
1063 cfs_hash_putref(s->ls_obj_hash);
1064 s->ls_obj_hash = NULL;
1067 if (s->ls_top_dev != NULL) {
1068 s->ls_top_dev->ld_site = NULL;
1069 lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s);
1070 lu_device_put(s->ls_top_dev);
1071 s->ls_top_dev = NULL;
1074 if (s->ls_stats != NULL)
1075 lprocfs_free_stats(&s->ls_stats);
1077 EXPORT_SYMBOL(lu_site_fini);
1080 * Called when initialization of stack for this site is completed.
1082 int lu_site_init_finish(struct lu_site *s)
1085 mutex_lock(&lu_sites_guard);
1086 result = lu_context_refill(&lu_shrink_env.le_ctx);
1088 list_add(&s->ls_linkage, &lu_sites);
1089 mutex_unlock(&lu_sites_guard);
1092 EXPORT_SYMBOL(lu_site_init_finish);
1095 * Acquire additional reference on device \a d
1097 void lu_device_get(struct lu_device *d)
1099 atomic_inc(&d->ld_ref);
1101 EXPORT_SYMBOL(lu_device_get);
1104 * Release reference on device \a d.
1106 void lu_device_put(struct lu_device *d)
1108 LASSERT(atomic_read(&d->ld_ref) > 0);
1109 atomic_dec(&d->ld_ref);
1111 EXPORT_SYMBOL(lu_device_put);
1114 * Initialize device \a d of type \a t.
1116 int lu_device_init(struct lu_device *d, struct lu_device_type *t)
1118 if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start != NULL)
1119 t->ldt_ops->ldto_start(t);
1120 memset(d, 0, sizeof(*d));
1121 atomic_set(&d->ld_ref, 0);
1123 lu_ref_init(&d->ld_reference);
1124 INIT_LIST_HEAD(&d->ld_linkage);
1127 EXPORT_SYMBOL(lu_device_init);
1130 * Finalize device \a d.
1132 void lu_device_fini(struct lu_device *d)
1134 struct lu_device_type *t;
1137 if (d->ld_obd != NULL) {
1138 d->ld_obd->obd_lu_dev = NULL;
1142 lu_ref_fini(&d->ld_reference);
1143 LASSERTF(atomic_read(&d->ld_ref) == 0,
1144 "Refcount is %u\n", atomic_read(&d->ld_ref));
1145 LASSERT(t->ldt_device_nr > 0);
1146 if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop != NULL)
1147 t->ldt_ops->ldto_stop(t);
1149 EXPORT_SYMBOL(lu_device_fini);
1152 * Initialize object \a o that is part of compound object \a h and was created
1155 int lu_object_init(struct lu_object *o, struct lu_object_header *h,
1156 struct lu_device *d)
1158 memset(o, 0, sizeof(*o));
1162 lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o);
1163 INIT_LIST_HEAD(&o->lo_linkage);
1167 EXPORT_SYMBOL(lu_object_init);
1170 * Finalize object and release its resources.
1172 void lu_object_fini(struct lu_object *o)
1174 struct lu_device *dev = o->lo_dev;
1176 LASSERT(list_empty(&o->lo_linkage));
1179 lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref,
1185 EXPORT_SYMBOL(lu_object_fini);
1188 * Add object \a o as first layer of compound object \a h
1190 * This is typically called by the ->ldo_object_alloc() method of top-level
1193 void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
1195 list_move(&o->lo_linkage, &h->loh_layers);
1197 EXPORT_SYMBOL(lu_object_add_top);
1200 * Add object \a o as a layer of compound object, going after \a before.
1202 * This is typically called by the ->ldo_object_alloc() method of \a
1205 void lu_object_add(struct lu_object *before, struct lu_object *o)
1207 list_move(&o->lo_linkage, &before->lo_linkage);
1209 EXPORT_SYMBOL(lu_object_add);
1212 * Initialize compound object.
1214 int lu_object_header_init(struct lu_object_header *h)
1216 memset(h, 0, sizeof(*h));
1217 atomic_set(&h->loh_ref, 1);
1218 INIT_HLIST_NODE(&h->loh_hash);
1219 INIT_LIST_HEAD(&h->loh_lru);
1220 INIT_LIST_HEAD(&h->loh_layers);
1221 lu_ref_init(&h->loh_reference);
1224 EXPORT_SYMBOL(lu_object_header_init);
1227 * Finalize compound object.
1229 void lu_object_header_fini(struct lu_object_header *h)
1231 LASSERT(list_empty(&h->loh_layers));
1232 LASSERT(list_empty(&h->loh_lru));
1233 LASSERT(hlist_unhashed(&h->loh_hash));
1234 lu_ref_fini(&h->loh_reference);
1236 EXPORT_SYMBOL(lu_object_header_fini);
1239 * Given a compound object, find its slice, corresponding to the device type
1242 struct lu_object *lu_object_locate(struct lu_object_header *h,
1243 const struct lu_device_type *dtype)
1245 struct lu_object *o;
1247 list_for_each_entry(o, &h->loh_layers, lo_linkage) {
1248 if (o->lo_dev->ld_type == dtype)
1253 EXPORT_SYMBOL(lu_object_locate);
1258 * Finalize and free devices in the device stack.
1260 * Finalize device stack by purging object cache, and calling
1261 * lu_device_type_operations::ldto_device_fini() and
1262 * lu_device_type_operations::ldto_device_free() on all devices in the stack.
1264 void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
1266 struct lu_site *site = top->ld_site;
1267 struct lu_device *scan;
1268 struct lu_device *next;
1270 lu_site_purge(env, site, ~0);
1271 for (scan = top; scan != NULL; scan = next) {
1272 next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan);
1273 lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init);
1274 lu_device_put(scan);
1278 lu_site_purge(env, site, ~0);
1280 for (scan = top; scan != NULL; scan = next) {
1281 const struct lu_device_type *ldt = scan->ld_type;
1282 struct obd_type *type;
1284 next = ldt->ldt_ops->ldto_device_free(env, scan);
1285 type = ldt->ldt_obd_type;
1288 class_put_type(type);
1292 EXPORT_SYMBOL(lu_stack_fini);
1296 * Maximal number of tld slots.
1298 LU_CONTEXT_KEY_NR = 40
1301 static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
1303 static DEFINE_SPINLOCK(lu_keys_guard);
1306 * Global counter incremented whenever key is registered, unregistered,
1307 * revived or quiesced. This is used to void unnecessary calls to
1308 * lu_context_refill(). No locking is provided, as initialization and shutdown
1309 * are supposed to be externally serialized.
1311 static unsigned key_set_version;
1316 int lu_context_key_register(struct lu_context_key *key)
1321 LASSERT(key->lct_init != NULL);
1322 LASSERT(key->lct_fini != NULL);
1323 LASSERT(key->lct_tags != 0);
1326 spin_lock(&lu_keys_guard);
1327 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1328 if (lu_keys[i] == NULL) {
1330 atomic_set(&key->lct_used, 1);
1332 lu_ref_init(&key->lct_reference);
1338 spin_unlock(&lu_keys_guard);
1341 EXPORT_SYMBOL(lu_context_key_register);
1343 static void key_fini(struct lu_context *ctx, int index)
1345 if (ctx->lc_value != NULL && ctx->lc_value[index] != NULL) {
1346 struct lu_context_key *key;
1348 key = lu_keys[index];
1349 LASSERT(key != NULL);
1350 LASSERT(key->lct_fini != NULL);
1351 LASSERT(atomic_read(&key->lct_used) > 1);
1353 key->lct_fini(ctx, key, ctx->lc_value[index]);
1354 lu_ref_del(&key->lct_reference, "ctx", ctx);
1355 atomic_dec(&key->lct_used);
1357 if ((ctx->lc_tags & LCT_NOREF) == 0) {
1358 #ifdef CONFIG_MODULE_UNLOAD
1359 LINVRNT(module_refcount(key->lct_owner) > 0);
1361 module_put(key->lct_owner);
1363 ctx->lc_value[index] = NULL;
1370 void lu_context_key_degister(struct lu_context_key *key)
1372 LASSERT(atomic_read(&key->lct_used) >= 1);
1373 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1375 lu_context_key_quiesce(key);
1378 spin_lock(&lu_keys_guard);
1379 key_fini(&lu_shrink_env.le_ctx, key->lct_index);
1380 if (lu_keys[key->lct_index]) {
1381 lu_keys[key->lct_index] = NULL;
1382 lu_ref_fini(&key->lct_reference);
1384 spin_unlock(&lu_keys_guard);
1386 LASSERTF(atomic_read(&key->lct_used) == 1,
1387 "key has instances: %d\n",
1388 atomic_read(&key->lct_used));
1390 EXPORT_SYMBOL(lu_context_key_degister);
1393 * Register a number of keys. This has to be called after all keys have been
1394 * initialized by a call to LU_CONTEXT_KEY_INIT().
1396 int lu_context_key_register_many(struct lu_context_key *k, ...)
1398 struct lu_context_key *key = k;
1404 result = lu_context_key_register(key);
1407 key = va_arg(args, struct lu_context_key *);
1408 } while (key != NULL);
1414 lu_context_key_degister(k);
1415 k = va_arg(args, struct lu_context_key *);
1422 EXPORT_SYMBOL(lu_context_key_register_many);
1425 * De-register a number of keys. This is a dual to
1426 * lu_context_key_register_many().
1428 void lu_context_key_degister_many(struct lu_context_key *k, ...)
1434 lu_context_key_degister(k);
1435 k = va_arg(args, struct lu_context_key*);
1436 } while (k != NULL);
1439 EXPORT_SYMBOL(lu_context_key_degister_many);
1442 * Revive a number of keys.
1444 void lu_context_key_revive_many(struct lu_context_key *k, ...)
1450 lu_context_key_revive(k);
1451 k = va_arg(args, struct lu_context_key*);
1452 } while (k != NULL);
1455 EXPORT_SYMBOL(lu_context_key_revive_many);
1458 * Quiescent a number of keys.
1460 void lu_context_key_quiesce_many(struct lu_context_key *k, ...)
1466 lu_context_key_quiesce(k);
1467 k = va_arg(args, struct lu_context_key*);
1468 } while (k != NULL);
1471 EXPORT_SYMBOL(lu_context_key_quiesce_many);
1474 * Return value associated with key \a key in context \a ctx.
1476 void *lu_context_key_get(const struct lu_context *ctx,
1477 const struct lu_context_key *key)
1479 LINVRNT(ctx->lc_state == LCS_ENTERED);
1480 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1481 LASSERT(lu_keys[key->lct_index] == key);
1482 return ctx->lc_value[key->lct_index];
1484 EXPORT_SYMBOL(lu_context_key_get);
1487 * List of remembered contexts. XXX document me.
1489 static LIST_HEAD(lu_context_remembered);
1492 * Destroy \a key in all remembered contexts. This is used to destroy key
1493 * values in "shared" contexts (like service threads), when a module owning
1494 * the key is about to be unloaded.
1496 void lu_context_key_quiesce(struct lu_context_key *key)
1498 struct lu_context *ctx;
1500 if (!(key->lct_tags & LCT_QUIESCENT)) {
1502 * XXX layering violation.
1504 key->lct_tags |= LCT_QUIESCENT;
1506 * XXX memory barrier has to go here.
1508 spin_lock(&lu_keys_guard);
1509 list_for_each_entry(ctx, &lu_context_remembered,
1511 key_fini(ctx, key->lct_index);
1512 spin_unlock(&lu_keys_guard);
1516 EXPORT_SYMBOL(lu_context_key_quiesce);
1518 void lu_context_key_revive(struct lu_context_key *key)
1520 key->lct_tags &= ~LCT_QUIESCENT;
1523 EXPORT_SYMBOL(lu_context_key_revive);
1525 static void keys_fini(struct lu_context *ctx)
1529 if (ctx->lc_value == NULL)
1532 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i)
1535 OBD_FREE(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0]));
1536 ctx->lc_value = NULL;
1539 static int keys_fill(struct lu_context *ctx)
1543 LINVRNT(ctx->lc_value != NULL);
1544 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1545 struct lu_context_key *key;
1548 if (ctx->lc_value[i] == NULL && key != NULL &&
1549 (key->lct_tags & ctx->lc_tags) &&
1551 * Don't create values for a LCT_QUIESCENT key, as this
1552 * will pin module owning a key.
1554 !(key->lct_tags & LCT_QUIESCENT)) {
1557 LINVRNT(key->lct_init != NULL);
1558 LINVRNT(key->lct_index == i);
1560 value = key->lct_init(ctx, key);
1561 if (unlikely(IS_ERR(value)))
1562 return PTR_ERR(value);
1564 if (!(ctx->lc_tags & LCT_NOREF))
1565 try_module_get(key->lct_owner);
1566 lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
1567 atomic_inc(&key->lct_used);
1569 * This is the only place in the code, where an
1570 * element of ctx->lc_value[] array is set to non-NULL
1573 ctx->lc_value[i] = value;
1574 if (key->lct_exit != NULL)
1575 ctx->lc_tags |= LCT_HAS_EXIT;
1577 ctx->lc_version = key_set_version;
1582 static int keys_init(struct lu_context *ctx)
1584 OBD_ALLOC(ctx->lc_value,
1585 ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0]));
1586 if (likely(ctx->lc_value != NULL))
1587 return keys_fill(ctx);
1593 * Initialize context data-structure. Create values for all keys.
1595 int lu_context_init(struct lu_context *ctx, __u32 tags)
1599 memset(ctx, 0, sizeof(*ctx));
1600 ctx->lc_state = LCS_INITIALIZED;
1601 ctx->lc_tags = tags;
1602 if (tags & LCT_REMEMBER) {
1603 spin_lock(&lu_keys_guard);
1604 list_add(&ctx->lc_remember, &lu_context_remembered);
1605 spin_unlock(&lu_keys_guard);
1607 INIT_LIST_HEAD(&ctx->lc_remember);
1610 rc = keys_init(ctx);
1612 lu_context_fini(ctx);
1616 EXPORT_SYMBOL(lu_context_init);
1619 * Finalize context data-structure. Destroy key values.
1621 void lu_context_fini(struct lu_context *ctx)
1623 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1624 ctx->lc_state = LCS_FINALIZED;
1626 if ((ctx->lc_tags & LCT_REMEMBER) == 0) {
1627 LASSERT(list_empty(&ctx->lc_remember));
1630 } else { /* could race with key degister */
1631 spin_lock(&lu_keys_guard);
1633 list_del_init(&ctx->lc_remember);
1634 spin_unlock(&lu_keys_guard);
1637 EXPORT_SYMBOL(lu_context_fini);
1640 * Called before entering context.
1642 void lu_context_enter(struct lu_context *ctx)
1644 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1645 ctx->lc_state = LCS_ENTERED;
1647 EXPORT_SYMBOL(lu_context_enter);
1650 * Called after exiting from \a ctx
1652 void lu_context_exit(struct lu_context *ctx)
1656 LINVRNT(ctx->lc_state == LCS_ENTERED);
1657 ctx->lc_state = LCS_LEFT;
1658 if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
1659 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1660 if (ctx->lc_value[i] != NULL) {
1661 struct lu_context_key *key;
1664 LASSERT(key != NULL);
1665 if (key->lct_exit != NULL)
1667 key, ctx->lc_value[i]);
1672 EXPORT_SYMBOL(lu_context_exit);
1675 * Allocate for context all missing keys that were registered after context
1676 * creation. key_set_version is only changed in rare cases when modules
1677 * are loaded and removed.
1679 int lu_context_refill(struct lu_context *ctx)
1681 return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);
1683 EXPORT_SYMBOL(lu_context_refill);
1686 * lu_ctx_tags/lu_ses_tags will be updated if there are new types of
1687 * obd being added. Currently, this is only used on client side, specifically
1688 * for echo device client, for other stack (like ptlrpc threads), context are
1689 * predefined when the lu_device type are registered, during the module probe
1692 __u32 lu_context_tags_default = 0;
1693 __u32 lu_session_tags_default = 0;
1695 void lu_context_tags_update(__u32 tags)
1697 spin_lock(&lu_keys_guard);
1698 lu_context_tags_default |= tags;
1700 spin_unlock(&lu_keys_guard);
1702 EXPORT_SYMBOL(lu_context_tags_update);
1704 void lu_context_tags_clear(__u32 tags)
1706 spin_lock(&lu_keys_guard);
1707 lu_context_tags_default &= ~tags;
1709 spin_unlock(&lu_keys_guard);
1711 EXPORT_SYMBOL(lu_context_tags_clear);
1713 void lu_session_tags_update(__u32 tags)
1715 spin_lock(&lu_keys_guard);
1716 lu_session_tags_default |= tags;
1718 spin_unlock(&lu_keys_guard);
1720 EXPORT_SYMBOL(lu_session_tags_update);
1722 void lu_session_tags_clear(__u32 tags)
1724 spin_lock(&lu_keys_guard);
1725 lu_session_tags_default &= ~tags;
1727 spin_unlock(&lu_keys_guard);
1729 EXPORT_SYMBOL(lu_session_tags_clear);
1731 int lu_env_init(struct lu_env *env, __u32 tags)
1736 result = lu_context_init(&env->le_ctx, tags);
1737 if (likely(result == 0))
1738 lu_context_enter(&env->le_ctx);
1741 EXPORT_SYMBOL(lu_env_init);
1743 void lu_env_fini(struct lu_env *env)
1745 lu_context_exit(&env->le_ctx);
1746 lu_context_fini(&env->le_ctx);
1749 EXPORT_SYMBOL(lu_env_fini);
1751 int lu_env_refill(struct lu_env *env)
1755 result = lu_context_refill(&env->le_ctx);
1756 if (result == 0 && env->le_ses != NULL)
1757 result = lu_context_refill(env->le_ses);
1760 EXPORT_SYMBOL(lu_env_refill);
1763 * Currently, this API will only be used by echo client.
1764 * Because echo client and normal lustre client will share
1765 * same cl_env cache. So echo client needs to refresh
1766 * the env context after it get one from the cache, especially
1767 * when normal client and echo client co-exist in the same client.
1769 int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags,
1772 if ((env->le_ctx.lc_tags & ctags) != ctags) {
1773 env->le_ctx.lc_version = 0;
1774 env->le_ctx.lc_tags |= ctags;
1777 if (env->le_ses && (env->le_ses->lc_tags & stags) != stags) {
1778 env->le_ses->lc_version = 0;
1779 env->le_ses->lc_tags |= stags;
1782 return lu_env_refill(env);
1784 EXPORT_SYMBOL(lu_env_refill_by_tags);
1787 typedef struct lu_site_stats{
1788 unsigned lss_populated;
1789 unsigned lss_max_search;
1794 static void lu_site_stats_get(struct cfs_hash *hs,
1795 lu_site_stats_t *stats, int populated)
1797 struct cfs_hash_bd bd;
1800 cfs_hash_for_each_bucket(hs, &bd, i) {
1801 struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd);
1802 struct hlist_head *hhead;
1804 cfs_hash_bd_lock(hs, &bd, 1);
1805 stats->lss_busy += bkt->lsb_busy;
1806 stats->lss_total += cfs_hash_bd_count_get(&bd);
1807 stats->lss_max_search = max((int)stats->lss_max_search,
1808 cfs_hash_bd_depmax_get(&bd));
1810 cfs_hash_bd_unlock(hs, &bd, 1);
1814 cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
1815 if (!hlist_empty(hhead))
1816 stats->lss_populated++;
1818 cfs_hash_bd_unlock(hs, &bd, 1);
1824 * There exists a potential lock inversion deadlock scenario when using
1825 * Lustre on top of ZFS. This occurs between one of ZFS's
1826 * buf_hash_table.ht_lock's, and Lustre's lu_sites_guard lock. Essentially,
1827 * thread A will take the lu_sites_guard lock and sleep on the ht_lock,
1828 * while thread B will take the ht_lock and sleep on the lu_sites_guard
1829 * lock. Obviously neither thread will wake and drop their respective hold
1832 * To prevent this from happening we must ensure the lu_sites_guard lock is
1833 * not taken while down this code path. ZFS reliably does not set the
1834 * __GFP_FS bit in its code paths, so this can be used to determine if it
1835 * is safe to take the lu_sites_guard lock.
1837 * Ideally we should accurately return the remaining number of cached
1838 * objects without taking the lu_sites_guard lock, but this is not
1839 * possible in the current implementation.
1841 static unsigned long lu_cache_shrink_count(struct shrinker *sk,
1842 struct shrink_control *sc)
1844 lu_site_stats_t stats;
1846 struct lu_site *tmp;
1847 unsigned long cached = 0;
1849 if (!(sc->gfp_mask & __GFP_FS))
1852 mutex_lock(&lu_sites_guard);
1853 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1854 memset(&stats, 0, sizeof(stats));
1855 lu_site_stats_get(s->ls_obj_hash, &stats, 0);
1856 cached += stats.lss_total - stats.lss_busy;
1858 mutex_unlock(&lu_sites_guard);
1860 cached = (cached / 100) * sysctl_vfs_cache_pressure;
1861 CDEBUG(D_INODE, "%ld objects cached\n", cached);
1865 static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
1866 struct shrink_control *sc)
1869 struct lu_site *tmp;
1870 unsigned long remain = sc->nr_to_scan, freed = 0;
1873 if (!(sc->gfp_mask & __GFP_FS))
1874 /* We must not take the lu_sites_guard lock when
1875 * __GFP_FS is *not* set because of the deadlock
1876 * possibility detailed above. Additionally,
1877 * since we cannot determine the number of
1878 * objects in the cache without taking this
1879 * lock, we're in a particularly tough spot. As
1880 * a result, we'll just lie and say our cache is
1881 * empty. This _should_ be ok, as we can't
1882 * reclaim objects when __GFP_FS is *not* set
1887 mutex_lock(&lu_sites_guard);
1888 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1889 freed = lu_site_purge(&lu_shrink_env, s, remain);
1892 * Move just shrunk site to the tail of site list to
1893 * assure shrinking fairness.
1895 list_move_tail(&s->ls_linkage, &splice);
1897 list_splice(&splice, lu_sites.prev);
1898 mutex_unlock(&lu_sites_guard);
1900 return sc->nr_to_scan - remain;
1908 * Environment to be used in debugger, contains all tags.
1910 struct lu_env lu_debugging_env;
1913 * Debugging printer function using printk().
1915 int lu_printk_printer(const struct lu_env *env,
1916 void *unused, const char *format, ...)
1920 va_start(args, format);
1921 vprintk(format, args);
1926 static struct shrinker lu_site_shrinker = {
1927 .count_objects = lu_cache_shrink_count,
1928 .scan_objects = lu_cache_shrink_scan,
1929 .seeks = DEFAULT_SEEKS,
1933 * Initialization of global lu_* data.
1935 int lu_global_init(void)
1939 CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys);
1941 result = lu_ref_global_init();
1945 LU_CONTEXT_KEY_INIT(&lu_global_key);
1946 result = lu_context_key_register(&lu_global_key);
1951 * At this level, we don't know what tags are needed, so allocate them
1952 * conservatively. This should not be too bad, because this
1953 * environment is global.
1955 mutex_lock(&lu_sites_guard);
1956 result = lu_env_init(&lu_shrink_env, LCT_SHRINKER);
1957 mutex_unlock(&lu_sites_guard);
1962 * seeks estimation: 3 seeks to read a record from oi, one to read
1963 * inode, one for ea. Unfortunately setting this high value results in
1964 * lu_object/inode cache consuming all the memory.
1966 register_shrinker(&lu_site_shrinker);
1972 * Dual to lu_global_init().
1974 void lu_global_fini(void)
1976 unregister_shrinker(&lu_site_shrinker);
1977 lu_context_key_degister(&lu_global_key);
1980 * Tear shrinker environment down _after_ de-registering
1981 * lu_global_key, because the latter has a value in the former.
1983 mutex_lock(&lu_sites_guard);
1984 lu_env_fini(&lu_shrink_env);
1985 mutex_unlock(&lu_sites_guard);
1987 lu_ref_global_fini();
1990 static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
1992 #if defined (CONFIG_PROC_FS)
1993 struct lprocfs_counter ret;
1995 lprocfs_stats_collect(stats, idx, &ret);
1996 return (__u32)ret.lc_count;
2003 * Output site statistical counters into a buffer. Suitable for
2004 * lprocfs_rd_*()-style functions.
2006 int lu_site_stats_print(const struct lu_site *s, struct seq_file *m)
2008 lu_site_stats_t stats;
2010 memset(&stats, 0, sizeof(stats));
2011 lu_site_stats_get(s->ls_obj_hash, &stats, 1);
2013 seq_printf(m, "%d/%d %d/%d %d %d %d %d %d %d %d\n",
2016 stats.lss_populated,
2017 CFS_HASH_NHLIST(s->ls_obj_hash),
2018 stats.lss_max_search,
2019 ls_stats_read(s->ls_stats, LU_SS_CREATED),
2020 ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
2021 ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
2022 ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
2023 ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
2024 ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
2027 EXPORT_SYMBOL(lu_site_stats_print);
2030 * Helper function to initialize a number of kmem slab caches at once.
2032 int lu_kmem_init(struct lu_kmem_descr *caches)
2035 struct lu_kmem_descr *iter = caches;
2037 for (result = 0; iter->ckd_cache != NULL; ++iter) {
2038 *iter->ckd_cache = kmem_cache_create(iter->ckd_name,
2041 if (*iter->ckd_cache == NULL) {
2043 /* free all previously allocated caches */
2044 lu_kmem_fini(caches);
2050 EXPORT_SYMBOL(lu_kmem_init);
2053 * Helper function to finalize a number of kmem slab cached at once. Dual to
2056 void lu_kmem_fini(struct lu_kmem_descr *caches)
2058 for (; caches->ckd_cache != NULL; ++caches) {
2059 if (*caches->ckd_cache != NULL) {
2060 kmem_cache_destroy(*caches->ckd_cache);
2061 *caches->ckd_cache = NULL;
2065 EXPORT_SYMBOL(lu_kmem_fini);
2068 * Temporary solution to be able to assign fid in ->do_create()
2069 * till we have fully-functional OST fids
2071 void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
2072 const struct lu_fid *fid)
2074 struct lu_site *s = o->lo_dev->ld_site;
2075 struct lu_fid *old = &o->lo_header->loh_fid;
2076 struct lu_site_bkt_data *bkt;
2077 struct lu_object *shadow;
2078 wait_queue_t waiter;
2079 struct cfs_hash *hs;
2080 struct cfs_hash_bd bd;
2083 LASSERT(fid_is_zero(old));
2085 hs = s->ls_obj_hash;
2086 cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1);
2087 shadow = htable_lookup(s, &bd, fid, &waiter, &version);
2088 /* supposed to be unique */
2089 LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
2091 bkt = cfs_hash_bd_extra_get(hs, &bd);
2092 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
2094 cfs_hash_bd_unlock(hs, &bd, 1);
2096 EXPORT_SYMBOL(lu_object_assign_fid);
2099 * allocates object with 0 (non-assigned) fid
2100 * XXX: temporary solution to be able to assign fid in ->do_create()
2101 * till we have fully-functional OST fids
2103 struct lu_object *lu_object_anon(const struct lu_env *env,
2104 struct lu_device *dev,
2105 const struct lu_object_conf *conf)
2108 struct lu_object *o;
2111 o = lu_object_alloc(env, dev, &fid, conf);
2115 EXPORT_SYMBOL(lu_object_anon);
2117 struct lu_buf LU_BUF_NULL = {
2121 EXPORT_SYMBOL(LU_BUF_NULL);
2123 void lu_buf_free(struct lu_buf *buf)
2127 LASSERT(buf->lb_len > 0);
2128 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
2133 EXPORT_SYMBOL(lu_buf_free);
2135 void lu_buf_alloc(struct lu_buf *buf, int size)
2138 LASSERT(buf->lb_buf == NULL);
2139 LASSERT(buf->lb_len == 0);
2140 OBD_ALLOC_LARGE(buf->lb_buf, size);
2141 if (likely(buf->lb_buf))
2144 EXPORT_SYMBOL(lu_buf_alloc);
2146 void lu_buf_realloc(struct lu_buf *buf, int size)
2149 lu_buf_alloc(buf, size);
2151 EXPORT_SYMBOL(lu_buf_realloc);
2153 struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len)
2155 if (buf->lb_buf == NULL && buf->lb_len == 0)
2156 lu_buf_alloc(buf, len);
2158 if ((len > buf->lb_len) && (buf->lb_buf != NULL))
2159 lu_buf_realloc(buf, len);
2163 EXPORT_SYMBOL(lu_buf_check_and_alloc);
2166 * Increase the size of the \a buf.
2167 * preserves old data in buffer
2168 * old buffer remains unchanged on error
2169 * \retval 0 or -ENOMEM
2171 int lu_buf_check_and_grow(struct lu_buf *buf, int len)
2175 if (len <= buf->lb_len)
2178 OBD_ALLOC_LARGE(ptr, len);
2182 /* Free the old buf */
2183 if (buf->lb_buf != NULL) {
2184 memcpy(ptr, buf->lb_buf, buf->lb_len);
2185 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
2192 EXPORT_SYMBOL(lu_buf_check_and_grow);