1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2 * vim:expandtab:shiftwidth=8:tabstop=8:
6 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License version 2 only,
10 * as published by the Free Software Foundation.
12 * This program is distributed in the hope that it will be useful, but
13 * WITHOUT ANY WARRANTY; without even the implied warranty of
14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU
15 * General Public License version 2 for more details (a copy is included
16 * in the LICENSE file that accompanied this code).
18 * You should have received a copy of the GNU General Public License
19 * version 2 along with this program; If not, see
20 * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
22 * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23 * CA 95054 USA or visit www.sun.com if you need additional information or
29 * Copyright 2008 Sun Microsystems, Inc. All rights reserved
30 * Use is subject to license terms.
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 # define EXPORT_SYMTAB
50 #include <libcfs/libcfs.h>
53 # include <linux/module.h>
57 #include <libcfs/libcfs_hash.h>
58 #include <obd_class.h>
59 #include <obd_support.h>
60 #include <lustre_disk.h>
61 #include <lustre_fid.h>
62 #include <lu_object.h>
63 #include <libcfs/list.h>
64 /* lu_time_global_{init,fini}() */
67 static void lu_object_free(const struct lu_env *env, struct lu_object *o);
70 * Decrease reference counter on object. If last reference is freed, return
71 * object to the cache, unless lu_object_is_dying(o) holds. In the latter
72 * case, free object immediately.
74 void lu_object_put(const struct lu_env *env, struct lu_object *o)
76 struct lu_object_header *top;
78 struct lu_object *orig;
82 site = o->lo_dev->ld_site;
85 write_lock(&site->ls_guard);
86 if (atomic_dec_and_test(&top->loh_ref)) {
88 * When last reference is released, iterate over object
89 * layers, and notify them that object is no longer busy.
91 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
92 if (o->lo_ops->loo_object_release != NULL)
93 o->lo_ops->loo_object_release(env, o);
96 if (lu_object_is_dying(top)) {
98 * If object is dying (will not be cached), removed it
99 * from hash table and LRU.
101 * This is done with hash table and LRU lists
102 * locked. As the only way to acquire first reference
103 * to previously unreferenced object is through
104 * hash-table lookup (lu_object_find()), or LRU
105 * scanning (lu_site_purge()), that are done under
106 * hash-table and LRU lock, no race with concurrent
107 * object lookup is possible and we can safely destroy
110 hlist_del_init(&top->loh_hash);
111 list_del_init(&top->loh_lru);
116 write_unlock(&site->ls_guard);
119 * Object was already removed from hash and lru above, can
122 lu_object_free(env, orig);
124 EXPORT_SYMBOL(lu_object_put);
127 * Allocate new object.
129 * This follows object creation protocol, described in the comment within
130 * struct lu_device_operations definition.
132 static struct lu_object *lu_object_alloc(const struct lu_env *env,
133 struct lu_device *dev,
134 const struct lu_fid *f,
135 const struct lu_object_conf *conf)
137 struct lu_object *scan;
138 struct lu_object *top;
139 struct list_head *layers;
145 * Create top-level object slice. This will also create
148 top = dev->ld_ops->ldo_object_alloc(env, NULL, dev);
150 RETURN(ERR_PTR(-ENOMEM));
152 * This is the only place where object fid is assigned. It's constant
155 LASSERT(fid_is_igif(f) || fid_ver(f) == 0);
156 top->lo_header->loh_fid = *f;
157 layers = &top->lo_header->loh_layers;
160 * Call ->loo_object_init() repeatedly, until no more new
161 * object slices are created.
164 list_for_each_entry(scan, layers, lo_linkage) {
165 if (scan->lo_flags & LU_OBJECT_ALLOCATED)
168 scan->lo_header = top->lo_header;
169 result = scan->lo_ops->loo_object_init(env, scan, conf);
171 lu_object_free(env, top);
172 RETURN(ERR_PTR(result));
174 scan->lo_flags |= LU_OBJECT_ALLOCATED;
178 list_for_each_entry_reverse(scan, layers, lo_linkage) {
179 if (scan->lo_ops->loo_object_start != NULL) {
180 result = scan->lo_ops->loo_object_start(env, scan);
182 lu_object_free(env, top);
183 RETURN(ERR_PTR(result));
188 dev->ld_site->ls_stats.s_created ++;
195 static void lu_object_free(const struct lu_env *env, struct lu_object *o)
197 struct list_head splice;
198 struct lu_object *scan;
199 struct lu_site *site;
200 struct list_head *layers;
202 site = o->lo_dev->ld_site;
203 layers = &o->lo_header->loh_layers;
205 * First call ->loo_object_delete() method to release all resources.
207 list_for_each_entry_reverse(scan, layers, lo_linkage) {
208 if (scan->lo_ops->loo_object_delete != NULL)
209 scan->lo_ops->loo_object_delete(env, scan);
213 * Then, splice object layers into stand-alone list, and call
214 * ->loo_object_free() on all layers to free memory. Splice is
215 * necessary, because lu_object_header is freed together with the
218 CFS_INIT_LIST_HEAD(&splice);
219 list_splice_init(layers, &splice);
220 while (!list_empty(&splice)) {
222 * Free layers in bottom-to-top order, so that object header
223 * lives as long as possible and ->loo_object_free() methods
224 * can look at its contents.
226 o = container_of0(splice.prev, struct lu_object, lo_linkage);
227 list_del_init(&o->lo_linkage);
228 LASSERT(o->lo_ops->loo_object_free != NULL);
229 o->lo_ops->loo_object_free(env, o);
231 cfs_waitq_broadcast(&site->ls_marche_funebre);
235 * Free \a nr objects from the cold end of the site LRU list.
237 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
239 struct list_head dispose;
240 struct lu_object_header *h;
241 struct lu_object_header *temp;
243 CFS_INIT_LIST_HEAD(&dispose);
245 * Under LRU list lock, scan LRU list and move unreferenced objects to
246 * the dispose list, removing them from LRU and hash table.
248 write_lock(&s->ls_guard);
249 list_for_each_entry_safe(h, temp, &s->ls_lru, loh_lru) {
251 * Objects are sorted in lru order, and "busy" objects (ones
252 * with h->loh_ref > 0) naturally tend to live near hot end
253 * that we scan last. Unfortunately, sites usually have small
254 * (less then ten) number of busy yet rarely accessed objects
255 * (some global objects, accessed directly through pointers,
256 * bypassing hash table). Currently algorithm scans them over
257 * and over again. Probably we should move busy objects out of
258 * LRU, or we can live with that.
262 if (atomic_read(&h->loh_ref) > 0)
264 hlist_del_init(&h->loh_hash);
265 list_move(&h->loh_lru, &dispose);
268 write_unlock(&s->ls_guard);
270 * Free everything on the dispose list. This is safe against races due
271 * to the reasons described in lu_object_put().
273 while (!list_empty(&dispose)) {
274 h = container_of0(dispose.next,
275 struct lu_object_header, loh_lru);
276 list_del_init(&h->loh_lru);
277 lu_object_free(env, lu_object_top(h));
278 s->ls_stats.s_lru_purged ++;
282 EXPORT_SYMBOL(lu_site_purge);
287 * Code below has to jump through certain loops to output object description
288 * into libcfs_debug_msg-based log. The problem is that lu_object_print()
289 * composes object description from strings that are parts of _lines_ of
290 * output (i.e., strings that are not terminated by newline). This doesn't fit
291 * very well into libcfs_debug_msg() interface that assumes that each message
292 * supplied to it is a self-contained output line.
294 * To work around this, strings are collected in a temporary buffer
295 * (implemented as a value of lu_cdebug_key key), until terminating newline
296 * character is detected.
304 * XXX overflow is not handled correctly.
309 struct lu_cdebug_data {
313 char lck_area[LU_CDEBUG_LINE];
316 /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
317 LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data);
320 * Key, holding temporary buffer. This key is registered very early by
323 struct lu_context_key lu_global_key = {
324 .lct_tags = LCT_MD_THREAD|LCT_DT_THREAD|LCT_CL_THREAD,
325 .lct_init = lu_global_key_init,
326 .lct_fini = lu_global_key_fini
330 * Printer function emitting messages through libcfs_debug_msg().
332 int lu_cdebug_printer(const struct lu_env *env,
333 void *cookie, const char *format, ...)
335 struct lu_cdebug_print_info *info = cookie;
336 struct lu_cdebug_data *key;
341 va_start(args, format);
343 key = lu_context_key_get(&env->le_ctx, &lu_global_key);
344 LASSERT(key != NULL);
346 used = strlen(key->lck_area);
347 complete = format[strlen(format) - 1] == '\n';
349 * Append new chunk to the buffer.
351 vsnprintf(key->lck_area + used,
352 ARRAY_SIZE(key->lck_area) - used, format, args);
354 libcfs_debug_msg(NULL, info->lpi_subsys, info->lpi_mask,
355 (char *)info->lpi_file, info->lpi_fn,
356 info->lpi_line, "%s", key->lck_area);
357 key->lck_area[0] = 0;
362 EXPORT_SYMBOL(lu_cdebug_printer);
365 * Print object header.
367 static void lu_object_header_print(const struct lu_env *env,
368 void *cookie, lu_printer_t printer,
369 const struct lu_object_header *hdr)
371 (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
372 hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
374 hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
375 list_empty(&hdr->loh_lru) ? "" : " lru",
376 hdr->loh_attr & LOHA_EXISTS ? " exist":"");
380 * Print human readable representation of the @o to the @printer.
382 void lu_object_print(const struct lu_env *env, void *cookie,
383 lu_printer_t printer, const struct lu_object *o)
385 static const char ruler[] = "........................................";
386 struct lu_object_header *top;
390 lu_object_header_print(env, cookie, printer, top);
391 (*printer)(env, cookie, "\n");
392 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
393 depth = o->lo_depth + 4;
394 LASSERT(o->lo_ops->loo_object_print != NULL);
396 * print `.' @depth times.
398 (*printer)(env, cookie, "%*.*s", depth, depth, ruler);
399 o->lo_ops->loo_object_print(env, cookie, printer, o);
400 (*printer)(env, cookie, "\n");
403 EXPORT_SYMBOL(lu_object_print);
406 * Check object consistency.
408 int lu_object_invariant(const struct lu_object *o)
410 struct lu_object_header *top;
413 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
414 if (o->lo_ops->loo_object_invariant != NULL &&
415 !o->lo_ops->loo_object_invariant(o))
420 EXPORT_SYMBOL(lu_object_invariant);
422 static struct lu_object *htable_lookup(struct lu_site *s,
423 const struct hlist_head *bucket,
424 const struct lu_fid *f)
426 struct lu_object_header *h;
427 struct hlist_node *scan;
429 hlist_for_each_entry(h, scan, bucket, loh_hash) {
430 s->ls_stats.s_cache_check ++;
431 if (likely(lu_fid_eq(&h->loh_fid, f) &&
432 !lu_object_is_dying(h))) {
433 /* bump reference count... */
434 if (atomic_add_return(1, &h->loh_ref) == 1)
436 /* and move to the head of the LRU */
438 * XXX temporary disable this to measure effects of
439 * read-write locking.
441 /* list_move_tail(&h->loh_lru, &s->ls_lru); */
442 s->ls_stats.s_cache_hit ++;
443 return lu_object_top(h);
446 s->ls_stats.s_cache_miss ++;
450 static __u32 fid_hash(const struct lu_fid *f, int bits)
452 /* all objects with same id and different versions will belong to same
453 * collisions list. */
454 return hash_long(fid_flatten(f), bits);
458 * Search cache for an object with the fid @f. If such object is found, return
459 * it. Otherwise, create new object, insert it into cache and return it. In
460 * any case, additional reference is acquired on the returned object.
462 struct lu_object *lu_object_find(const struct lu_env *env,
463 struct lu_site *s, const struct lu_fid *f)
466 struct lu_object *shadow;
467 struct hlist_head *bucket;
470 * This uses standard index maintenance protocol:
472 * - search index under lock, and return object if found;
473 * - otherwise, unlock index, allocate new object;
474 * - lock index and search again;
475 * - if nothing is found (usual case), insert newly created
477 * - otherwise (race: other thread inserted object), free
478 * object just allocated.
483 bucket = s->ls_hash + fid_hash(f, s->ls_hash_bits);
485 read_lock(&s->ls_guard);
486 o = htable_lookup(s, bucket, f);
487 read_unlock(&s->ls_guard);
493 * Allocate new object. This may result in rather complicated
494 * operations, including fld queries, inode loading, etc.
496 o = lu_object_alloc(env, s, f);
497 if (unlikely(IS_ERR(o)))
500 LASSERT(lu_fid_eq(lu_object_fid(o), f));
502 write_lock(&s->ls_guard);
503 shadow = htable_lookup(s, bucket, f);
504 if (likely(shadow == NULL)) {
505 hlist_add_head(&o->lo_header->loh_hash, bucket);
506 list_add_tail(&o->lo_header->loh_lru, &s->ls_lru);
512 s->ls_stats.s_cache_race ++;
513 write_unlock(&s->ls_guard);
515 lu_object_free(env, o);
518 EXPORT_SYMBOL(lu_object_find);
522 * Global list of all device types.
524 static CFS_LIST_HEAD(lu_device_types);
526 int lu_device_type_init(struct lu_device_type *ldt)
530 CFS_INIT_LIST_HEAD(&ldt->ldt_linkage);
531 result = ldt->ldt_ops->ldto_init(ldt);
533 list_add(&ldt->ldt_linkage, &lu_device_types);
536 EXPORT_SYMBOL(lu_device_type_init);
538 void lu_device_type_fini(struct lu_device_type *ldt)
540 list_del_init(&ldt->ldt_linkage);
541 ldt->ldt_ops->ldto_fini(ldt);
543 EXPORT_SYMBOL(lu_device_type_fini);
545 void lu_types_stop(void)
547 struct lu_device_type *ldt;
549 list_for_each_entry(ldt, &lu_device_types, ldt_linkage) {
550 if (ldt->ldt_device_nr == 0)
551 ldt->ldt_ops->ldto_stop(ldt);
554 EXPORT_SYMBOL(lu_types_stop);
557 * Global list of all sites on this node
559 static CFS_LIST_HEAD(lu_sites);
560 static DECLARE_MUTEX(lu_sites_guard);
563 * Global environment used by site shrinker.
565 static struct lu_env lu_shrink_env;
568 * Print all objects in \a s.
570 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
571 lu_printer_t printer)
575 for (i = 0; i < s->ls_hash_size; ++i) {
576 struct lu_object_header *h;
577 struct hlist_node *scan;
579 read_lock(&s->ls_guard);
580 hlist_for_each_entry(h, scan, &s->ls_hash[i], loh_hash) {
582 if (!list_empty(&h->loh_layers)) {
583 const struct lu_object *obj;
585 obj = lu_object_top(h);
586 lu_object_print(env, cookie, printer, obj);
588 lu_object_header_print(env, cookie, printer, h);
590 read_unlock(&s->ls_guard);
593 EXPORT_SYMBOL(lu_site_print);
596 LU_CACHE_PERCENT = 20,
600 * Return desired hash table order.
602 static int lu_htable_order(void)
604 unsigned long cache_size;
608 * Calculate hash table size, assuming that we want reasonable
609 * performance when 20% of total memory is occupied by cache of
612 * Size of lu_object is (arbitrary) taken as 1K (together with inode).
614 cache_size = num_physpages;
616 #if BITS_PER_LONG == 32
617 /* limit hashtable size for lowmem systems to low RAM */
618 if (cache_size > 1 << (30 - CFS_PAGE_SHIFT))
619 cache_size = 1 << (30 - CFS_PAGE_SHIFT) * 3 / 4;
622 cache_size = cache_size / 100 * LU_CACHE_PERCENT *
623 (CFS_PAGE_SIZE / 1024);
625 for (bits = 1; (1 << bits) < cache_size; ++bits) {
631 static struct lock_class_key lu_site_guard_class;
634 * Initialize site \a s, with \a d as the top level device.
636 int lu_site_init(struct lu_site *s, struct lu_device *top)
643 memset(s, 0, sizeof *s);
644 rwlock_init(&s->ls_guard);
645 lockdep_set_class(&s->ls_guard, &lu_site_guard_class);
646 CFS_INIT_LIST_HEAD(&s->ls_lru);
647 CFS_INIT_LIST_HEAD(&s->ls_linkage);
648 cfs_waitq_init(&s->ls_marche_funebre);
652 lu_ref_add(&top->ld_reference, "site-top", s);
654 for (bits = lu_htable_order(), size = 1 << bits;
656 cfs_alloc_large(size * sizeof s->ls_hash[0])) == NULL;
657 --bits, size >>= 1) {
659 * Scale hash table down, until allocation succeeds.
664 s->ls_hash_size = size;
665 s->ls_hash_bits = bits;
666 s->ls_hash_mask = size - 1;
668 for (i = 0; i < size; i++)
669 INIT_HLIST_HEAD(&s->ls_hash[i]);
673 EXPORT_SYMBOL(lu_site_init);
676 * Finalize \a s and release its resources.
678 void lu_site_fini(struct lu_site *s)
680 LASSERT(list_empty(&s->ls_lru));
681 LASSERT(s->ls_total == 0);
683 down(&lu_sites_guard);
684 list_del_init(&s->ls_linkage);
687 if (s->ls_hash != NULL) {
689 for (i = 0; i < s->ls_hash_size; i++)
690 LASSERT(hlist_empty(&s->ls_hash[i]));
691 cfs_free_large(s->ls_hash);
694 if (s->ls_top_dev != NULL) {
695 s->ls_top_dev->ld_site = NULL;
696 lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s);
697 lu_device_put(s->ls_top_dev);
698 s->ls_top_dev = NULL;
701 EXPORT_SYMBOL(lu_site_fini);
704 * Called when initialization of stack for this site is completed.
706 int lu_site_init_finish(struct lu_site *s)
709 down(&lu_sites_guard);
710 result = lu_context_refill(&lu_shrink_env.le_ctx);
712 list_add(&s->ls_linkage, &lu_sites);
716 EXPORT_SYMBOL(lu_site_init_finish);
719 * Acquire additional reference on device \a d
721 void lu_device_get(struct lu_device *d)
723 atomic_inc(&d->ld_ref);
725 EXPORT_SYMBOL(lu_device_get);
728 * Release reference on device \a d.
730 void lu_device_put(struct lu_device *d)
732 LASSERT(atomic_read(&d->ld_ref) > 0);
733 atomic_dec(&d->ld_ref);
735 EXPORT_SYMBOL(lu_device_put);
738 * Initialize device \a d of type \a t.
740 int lu_device_init(struct lu_device *d, struct lu_device_type *t)
742 if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start != NULL)
743 t->ldt_ops->ldto_start(t);
744 memset(d, 0, sizeof *d);
745 atomic_set(&d->ld_ref, 0);
747 lu_ref_init(&d->ld_reference);
750 EXPORT_SYMBOL(lu_device_init);
753 * Finalize device \a d.
755 void lu_device_fini(struct lu_device *d)
757 struct lu_device_type *t;
760 if (d->ld_obd != NULL)
762 lprocfs_obd_cleanup(d->ld_obd);
764 lu_ref_fini(&d->ld_reference);
765 LASSERTF(atomic_read(&d->ld_ref) == 0,
766 "Refcount is %u\n", atomic_read(&d->ld_ref));
767 LASSERT(t->ldt_device_nr > 0);
768 if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop != NULL)
769 t->ldt_ops->ldto_stop(t);
771 EXPORT_SYMBOL(lu_device_fini);
774 * Initialize object \a o that is part of compound object \a h and was created
777 int lu_object_init(struct lu_object *o,
778 struct lu_object_header *h, struct lu_device *d)
780 memset(o, 0, sizeof *o);
784 o->lo_dev_ref = lu_ref_add(&d->ld_reference, "lu_object", o);
785 CFS_INIT_LIST_HEAD(&o->lo_linkage);
788 EXPORT_SYMBOL(lu_object_init);
791 * Finalize object and release its resources.
793 void lu_object_fini(struct lu_object *o)
795 struct lu_device *dev = o->lo_dev;
797 LASSERT(list_empty(&o->lo_linkage));
800 lu_ref_del_at(&dev->ld_reference,
801 o->lo_dev_ref , "lu_object", o);
806 EXPORT_SYMBOL(lu_object_fini);
809 * Add object \a o as first layer of compound object \a h
811 * This is typically called by the ->ldo_object_alloc() method of top-level
814 void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
816 list_move(&o->lo_linkage, &h->loh_layers);
818 EXPORT_SYMBOL(lu_object_add_top);
821 * Add object \a o as a layer of compound object, going after \a before.
823 * This is typically called by the ->ldo_object_alloc() method of \a
826 void lu_object_add(struct lu_object *before, struct lu_object *o)
828 list_move(&o->lo_linkage, &before->lo_linkage);
830 EXPORT_SYMBOL(lu_object_add);
833 * Initialize compound object.
835 int lu_object_header_init(struct lu_object_header *h)
837 memset(h, 0, sizeof *h);
838 atomic_set(&h->loh_ref, 1);
839 INIT_HLIST_NODE(&h->loh_hash);
840 CFS_INIT_LIST_HEAD(&h->loh_lru);
841 CFS_INIT_LIST_HEAD(&h->loh_layers);
842 lu_ref_init(&h->loh_reference);
845 EXPORT_SYMBOL(lu_object_header_init);
848 * Finalize compound object.
850 void lu_object_header_fini(struct lu_object_header *h)
852 LASSERT(list_empty(&h->loh_layers));
853 LASSERT(list_empty(&h->loh_lru));
854 LASSERT(hlist_unhashed(&h->loh_hash));
855 lu_ref_fini(&h->loh_reference);
857 EXPORT_SYMBOL(lu_object_header_fini);
860 * Given a compound object, find its slice, corresponding to the device type
863 struct lu_object *lu_object_locate(struct lu_object_header *h,
864 const struct lu_device_type *dtype)
868 list_for_each_entry(o, &h->loh_layers, lo_linkage) {
869 if (o->lo_dev->ld_type == dtype)
874 EXPORT_SYMBOL(lu_object_locate);
879 * Finalize and free devices in the device stack.
881 * Finalize device stack by purging object cache, and calling
882 * lu_device_type_operations::ldto_device_fini() and
883 * lu_device_type_operations::ldto_device_free() on all devices in the stack.
885 void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
887 struct lu_site *site = top->ld_site;
888 struct lu_device *scan;
889 struct lu_device *next;
891 lu_site_purge(env, site, ~0);
892 for (scan = top; scan != NULL; scan = next) {
893 next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan);
894 lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init);
899 lu_site_purge(env, site, ~0);
901 if (!list_empty(&site->ls_lru) || site->ls_total != 0) {
903 * Uh-oh, objects still exist.
905 static DECLARE_LU_CDEBUG_PRINT_INFO(cookie, D_ERROR);
907 lu_site_print(env, site, &cookie, lu_cdebug_printer);
910 for (scan = top; scan != NULL; scan = next) {
911 const struct lu_device_type *ldt = scan->ld_type;
912 struct obd_type *type;
914 next = ldt->ldt_ops->ldto_device_free(env, scan);
915 type = ldt->ldt_obd_type;
918 class_put_type(type);
922 EXPORT_SYMBOL(lu_stack_fini);
926 * Maximal number of tld slots.
928 LU_CONTEXT_KEY_NR = 32
931 static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
933 static spinlock_t lu_keys_guard = SPIN_LOCK_UNLOCKED;
936 * Global counter incremented whenever key is registered, unregistered,
937 * revived or quiesced. This is used to void unnecessary calls to
938 * lu_context_refill(). No locking is provided, as initialization and shutdown
939 * are supposed to be externally serialized.
941 static unsigned key_set_version = 0;
946 int lu_context_key_register(struct lu_context_key *key)
951 LASSERT(key->lct_init != NULL);
952 LASSERT(key->lct_fini != NULL);
953 LASSERT(key->lct_tags != 0);
954 LASSERT(key->lct_owner != NULL);
957 spin_lock(&lu_keys_guard);
958 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
959 if (lu_keys[i] == NULL) {
961 atomic_set(&key->lct_used, 1);
963 lu_ref_init(&key->lct_reference);
969 spin_unlock(&lu_keys_guard);
972 EXPORT_SYMBOL(lu_context_key_register);
974 static void key_fini(struct lu_context *ctx, int index)
976 if (ctx->lc_value[index] != NULL) {
977 struct lu_context_key *key;
979 key = lu_keys[index];
980 LASSERT(key != NULL);
981 LASSERT(key->lct_fini != NULL);
982 LASSERT(atomic_read(&key->lct_used) > 1);
984 key->lct_fini(ctx, key, ctx->lc_value[index]);
985 lu_ref_del(&key->lct_reference, "ctx", ctx);
986 atomic_dec(&key->lct_used);
987 LASSERT(key->lct_owner != NULL);
988 if (!(ctx->lc_tags & LCT_NOREF)) {
989 LASSERT(module_refcount(key->lct_owner) > 0);
990 module_put(key->lct_owner);
992 ctx->lc_value[index] = NULL;
999 void lu_context_key_degister(struct lu_context_key *key)
1001 LASSERT(atomic_read(&key->lct_used) >= 1);
1002 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1005 key_fini(&lu_shrink_env.le_ctx, key->lct_index);
1007 if (atomic_read(&key->lct_used) > 1)
1008 CERROR("key has instances.\n");
1009 spin_lock(&lu_keys_guard);
1010 lu_keys[key->lct_index] = NULL;
1011 spin_unlock(&lu_keys_guard);
1013 EXPORT_SYMBOL(lu_context_key_degister);
1016 * Register a number of keys. This has to be called after all keys have been
1017 * initialized by a call to LU_CONTEXT_KEY_INIT().
1019 int lu_context_key_register_many(struct lu_context_key *k, ...)
1021 struct lu_context_key *key = k;
1027 result = lu_context_key_register(key);
1030 key = va_arg(args, struct lu_context_key *);
1031 } while (key != NULL);
1037 lu_context_key_degister(k);
1038 k = va_arg(args, struct lu_context_key *);
1045 EXPORT_SYMBOL(lu_context_key_register_many);
1048 * De-register a number of keys. This is a dual to
1049 * lu_context_key_register_many().
1051 void lu_context_key_degister_many(struct lu_context_key *k, ...)
1057 lu_context_key_degister(k);
1058 k = va_arg(args, struct lu_context_key*);
1059 } while (k != NULL);
1062 EXPORT_SYMBOL(lu_context_key_degister_many);
1065 * Revive a number of keys.
1067 void lu_context_key_revive_many(struct lu_context_key *k, ...)
1073 lu_context_key_revive(k);
1074 k = va_arg(args, struct lu_context_key*);
1075 } while (k != NULL);
1078 EXPORT_SYMBOL(lu_context_key_revive_many);
1081 * Quiescent a number of keys.
1083 void lu_context_key_quiesce_many(struct lu_context_key *k, ...)
1089 lu_context_key_quiesce(k);
1090 k = va_arg(args, struct lu_context_key*);
1091 } while (k != NULL);
1094 EXPORT_SYMBOL(lu_context_key_quiesce_many);
1097 * Return value associated with key \a key in context \a ctx.
1099 void *lu_context_key_get(const struct lu_context *ctx,
1100 const struct lu_context_key *key)
1102 LINVRNT(ctx->lc_state == LCS_ENTERED);
1103 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1104 return ctx->lc_value[key->lct_index];
1106 EXPORT_SYMBOL(lu_context_key_get);
1109 * List of remembered contexts. XXX document me.
1111 static CFS_LIST_HEAD(lu_context_remembered);
1114 * Destroy \a key in all remembered contexts. This is used to destroy key
1115 * values in "shared" contexts (like service threads), when a module owning
1116 * the key is about to be unloaded.
1118 void lu_context_key_quiesce(struct lu_context_key *key)
1120 struct lu_context *ctx;
1122 if (!(key->lct_tags & LCT_QUIESCENT)) {
1123 key->lct_tags |= LCT_QUIESCENT;
1125 * XXX memory barrier has to go here.
1127 spin_lock(&lu_keys_guard);
1128 list_for_each_entry(ctx, &lu_context_remembered, lc_remember)
1129 key_fini(ctx, key->lct_index);
1130 spin_unlock(&lu_keys_guard);
1134 EXPORT_SYMBOL(lu_context_key_quiesce);
1136 void lu_context_key_revive(struct lu_context_key *key)
1138 key->lct_tags &= ~LCT_QUIESCENT;
1141 EXPORT_SYMBOL(lu_context_key_revive);
1143 static void keys_fini(struct lu_context *ctx)
1147 if (ctx->lc_value != NULL) {
1148 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i)
1150 OBD_FREE(ctx->lc_value,
1151 ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1152 ctx->lc_value = NULL;
1156 static int keys_fill(struct lu_context *ctx)
1160 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1161 struct lu_context_key *key;
1164 if (ctx->lc_value[i] == NULL && key != NULL &&
1165 (key->lct_tags & ctx->lc_tags) &&
1167 * Don't create values for a LCT_QUIESCENT key, as this
1168 * will pin module owning a key.
1170 !(key->lct_tags & LCT_QUIESCENT)) {
1173 LINVRNT(key->lct_init != NULL);
1174 LINVRNT(key->lct_index == i);
1176 value = key->lct_init(ctx, key);
1177 if (unlikely(IS_ERR(value)))
1178 return PTR_ERR(value);
1179 LASSERT(key->lct_owner != NULL);
1180 if (!(ctx->lc_tags & LCT_NOREF))
1181 try_module_get(key->lct_owner);
1182 lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
1183 atomic_inc(&key->lct_used);
1185 * This is the only place in the code, where an
1186 * element of ctx->lc_value[] array is set to non-NULL
1189 ctx->lc_value[i] = value;
1190 if (key->lct_exit != NULL)
1191 ctx->lc_tags |= LCT_HAS_EXIT;
1193 ctx->lc_version = key_set_version;
1198 static int keys_init(struct lu_context *ctx)
1202 OBD_ALLOC(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1203 if (likely(ctx->lc_value != NULL))
1204 result = keys_fill(ctx);
1214 * Initialize context data-structure. Create values for all keys.
1216 int lu_context_init(struct lu_context *ctx, __u32 tags)
1218 memset(ctx, 0, sizeof *ctx);
1219 ctx->lc_state = LCS_INITIALIZED;
1220 ctx->lc_tags = tags;
1221 if (tags & LCT_REMEMBER) {
1222 spin_lock(&lu_keys_guard);
1223 list_add(&ctx->lc_remember, &lu_context_remembered);
1224 spin_unlock(&lu_keys_guard);
1226 CFS_INIT_LIST_HEAD(&ctx->lc_remember);
1227 return keys_init(ctx);
1229 EXPORT_SYMBOL(lu_context_init);
1232 * Finalize context data-structure. Destroy key values.
1234 void lu_context_fini(struct lu_context *ctx)
1236 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1237 ctx->lc_state = LCS_FINALIZED;
1239 spin_lock(&lu_keys_guard);
1240 list_del_init(&ctx->lc_remember);
1241 spin_unlock(&lu_keys_guard);
1243 EXPORT_SYMBOL(lu_context_fini);
1246 * Called before entering context.
1248 void lu_context_enter(struct lu_context *ctx)
1250 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1251 ctx->lc_state = LCS_ENTERED;
1253 EXPORT_SYMBOL(lu_context_enter);
1256 * Called after exiting from \a ctx
1258 void lu_context_exit(struct lu_context *ctx)
1262 LINVRNT(ctx->lc_state == LCS_ENTERED);
1263 ctx->lc_state = LCS_LEFT;
1264 if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
1265 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1266 if (ctx->lc_value[i] != NULL) {
1267 struct lu_context_key *key;
1270 LASSERT(key != NULL);
1271 if (key->lct_exit != NULL)
1273 key, ctx->lc_value[i]);
1278 EXPORT_SYMBOL(lu_context_exit);
1281 * Allocate for context all missing keys that were registered after context
1284 int lu_context_refill(struct lu_context *ctx)
1286 LINVRNT(ctx->lc_value != NULL);
1287 return ctx->lc_version == key_set_version ? 0 : keys_fill(ctx);
1289 EXPORT_SYMBOL(lu_context_refill);
1291 static int lu_env_setup(struct lu_env *env, struct lu_context *ses,
1292 __u32 tags, int noref)
1296 LINVRNT(ergo(!noref, !(tags & LCT_NOREF)));
1299 result = lu_context_init(&env->le_ctx, tags);
1300 if (likely(result == 0))
1301 lu_context_enter(&env->le_ctx);
1305 static int lu_env_init_noref(struct lu_env *env, struct lu_context *ses,
1308 return lu_env_setup(env, ses, tags, 1);
1311 int lu_env_init(struct lu_env *env, struct lu_context *ses, __u32 tags)
1313 return lu_env_setup(env, ses, tags, 0);
1315 EXPORT_SYMBOL(lu_env_init);
1317 void lu_env_fini(struct lu_env *env)
1319 lu_context_exit(&env->le_ctx);
1320 lu_context_fini(&env->le_ctx);
1323 EXPORT_SYMBOL(lu_env_fini);
1325 int lu_env_refill(struct lu_env *env)
1329 result = lu_context_refill(&env->le_ctx);
1330 if (result == 0 && env->le_ses != NULL)
1331 result = lu_context_refill(env->le_ses);
1334 EXPORT_SYMBOL(lu_env_refill);
1336 static struct shrinker *lu_site_shrinker = NULL;
1339 static int lu_cache_shrink(int nr, unsigned int gfp_mask)
1342 struct lu_site *tmp;
1345 CFS_LIST_HEAD(splice);
1347 if (nr != 0 && !(gfp_mask & __GFP_FS))
1350 down(&lu_sites_guard);
1351 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1353 remain = lu_site_purge(&lu_shrink_env, s, remain);
1355 * Move just shrunk site to the tail of site list to
1356 * assure shrinking fairness.
1358 list_move_tail(&s->ls_linkage, &splice);
1360 read_lock(&s->ls_guard);
1361 cached += s->ls_total - s->ls_busy;
1362 read_unlock(&s->ls_guard);
1366 list_splice(&splice, lu_sites.prev);
1367 up(&lu_sites_guard);
1371 #else /* !__KERNEL__ */
1372 static int lu_cache_shrink(int nr, unsigned int gfp_mask)
1376 #endif /* __KERNEL__ */
1378 int lu_ref_global_init(void);
1379 void lu_ref_global_fini(void);
1382 * Initialization of global lu_* data.
1384 int lu_global_init(void)
1388 CDEBUG(D_CONSOLE, "Lustre LU module (%p).\n", &lu_keys);
1390 LU_CONTEXT_KEY_INIT(&lu_global_key);
1391 result = lu_context_key_register(&lu_global_key);
1395 * At this level, we don't know what tags are needed, so allocate them
1396 * conservatively. This should not be too bad, because this
1397 * environment is global.
1399 down(&lu_sites_guard);
1400 result = lu_env_init_noref(&lu_shrink_env, NULL, LCT_SHRINKER);
1401 up(&lu_sites_guard);
1405 result = lu_ref_global_init();
1409 * seeks estimation: 3 seeks to read a record from oi, one to read
1410 * inode, one for ea. Unfortunately setting this high value results in
1411 * lu_object/inode cache consuming all the memory.
1413 lu_site_shrinker = set_shrinker(DEFAULT_SEEKS, lu_cache_shrink);
1414 if (lu_site_shrinker == NULL)
1417 result = lu_time_global_init();
1422 * Dual to lu_global_init().
1424 void lu_global_fini(void)
1426 lu_time_global_fini();
1427 if (lu_site_shrinker != NULL) {
1428 remove_shrinker(lu_site_shrinker);
1429 lu_site_shrinker = NULL;
1432 lu_context_key_degister(&lu_global_key);
1435 * Tear shrinker environment down _after_ de-registering
1436 * lu_global_key, because the latter has a value in the former.
1438 down(&lu_sites_guard);
1439 lu_env_fini(&lu_shrink_env);
1440 up(&lu_sites_guard);
1442 lu_ref_global_fini();
1445 struct lu_buf LU_BUF_NULL = {
1449 EXPORT_SYMBOL(LU_BUF_NULL);
1452 * XXX: Functions below logically belong to fid module, but they are used by
1453 * dt_store_open(). Put them here until better place is found.
1456 void fid_pack(struct lu_fid_pack *pack, const struct lu_fid *fid,
1457 struct lu_fid *befider)
1467 * Two cases: compact 6 bytes representation for a common case, and
1468 * full 17 byte representation for "unusual" fid.
1472 * Check that usual case is really usual.
1474 CLASSERT(LUSTRE_SEQ_MAX_WIDTH < 0xffffull);
1476 if (fid_is_igif(fid) ||
1477 seq > 0xffffffull || oid > 0xffff || fid_ver(fid) != 0) {
1478 fid_cpu_to_be(befider, fid);
1479 recsize = sizeof *befider;
1481 unsigned char *small_befider;
1483 small_befider = (char *)befider;
1485 small_befider[0] = seq >> 16;
1486 small_befider[1] = seq >> 8;
1487 small_befider[2] = seq;
1489 small_befider[3] = oid >> 8;
1490 small_befider[4] = oid;
1494 memcpy(pack->fp_area, befider, recsize);
1495 pack->fp_len = recsize + 1;
1497 EXPORT_SYMBOL(fid_pack);
1499 int fid_unpack(const struct lu_fid_pack *pack, struct lu_fid *fid)
1504 switch (pack->fp_len) {
1505 case sizeof *fid + 1:
1506 memcpy(fid, pack->fp_area, sizeof *fid);
1507 fid_be_to_cpu(fid, fid);
1510 const unsigned char *area;
1512 area = pack->fp_area;
1513 fid->f_seq = (area[0] << 16) | (area[1] << 8) | area[2];
1514 fid->f_oid = (area[3] << 8) | area[4];
1519 CERROR("Unexpected packed fid size: %d\n", pack->fp_len);
1524 EXPORT_SYMBOL(fid_unpack);
1526 const char *lu_time_names[LU_TIME_NR] = {
1527 [LU_TIME_FIND_LOOKUP] = "find_lookup",
1528 [LU_TIME_FIND_ALLOC] = "find_alloc",
1529 [LU_TIME_FIND_INSERT] = "find_insert"
1531 EXPORT_SYMBOL(lu_time_names);