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).
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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, 2014, 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 <libcfs/libcfs.h>
48 #include <linux/module.h>
49 #include <libcfs/libcfs_hash.h> /* hash_long() */
50 #include <obd_class.h>
51 #include <obd_support.h>
52 #include <lustre_disk.h>
53 #include <lustre_fid.h>
54 #include <lu_object.h>
56 #include <libcfs/list.h>
59 LU_CACHE_PERCENT_MAX = 50,
60 LU_CACHE_PERCENT_DEFAULT = 20
63 #define LU_CACHE_NR_MAX_ADJUST 128
64 #define LU_CACHE_NR_UNLIMITED -1
65 #define LU_CACHE_NR_DEFAULT LU_CACHE_NR_UNLIMITED
66 #define LU_CACHE_NR_LDISKFS_LIMIT LU_CACHE_NR_UNLIMITED
67 /** This is set to roughly (20 * OSS_NTHRS_MAX) to prevent thrashing */
68 #define LU_CACHE_NR_ZFS_LIMIT 10240
70 #define LU_SITE_BITS_MIN 12
71 #define LU_SITE_BITS_MAX 24
73 * total 256 buckets, we don't want too many buckets because:
74 * - consume too much memory
75 * - avoid unbalanced LRU list
77 #define LU_SITE_BKT_BITS 8
80 static unsigned int lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
81 CFS_MODULE_PARM(lu_cache_percent, "i", int, 0644,
82 "Percentage of memory to be used as lu_object cache");
84 static long lu_cache_nr = LU_CACHE_NR_DEFAULT;
85 CFS_MODULE_PARM(lu_cache_nr, "l", long, 0644,
86 "Maximum number of objects in lu_object cache");
88 static void lu_object_free(const struct lu_env *env, struct lu_object *o);
91 * Decrease reference counter on object. If last reference is freed, return
92 * object to the cache, unless lu_object_is_dying(o) holds. In the latter
93 * case, free object immediately.
95 void lu_object_put(const struct lu_env *env, struct lu_object *o)
97 struct lu_site_bkt_data *bkt;
98 struct lu_object_header *top;
100 struct lu_object *orig;
102 const struct lu_fid *fid;
105 site = o->lo_dev->ld_site;
109 * till we have full fids-on-OST implemented anonymous objects
110 * are possible in OSP. such an object isn't listed in the site
111 * so we should not remove it from the site.
113 fid = lu_object_fid(o);
114 if (fid_is_zero(fid)) {
115 LASSERT(top->loh_hash.next == NULL
116 && top->loh_hash.pprev == NULL);
117 LASSERT(list_empty(&top->loh_lru));
118 if (!atomic_dec_and_test(&top->loh_ref))
120 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
121 if (o->lo_ops->loo_object_release != NULL)
122 o->lo_ops->loo_object_release(env, o);
124 lu_object_free(env, orig);
128 cfs_hash_bd_get(site->ls_obj_hash, &top->loh_fid, &bd);
129 bkt = cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
131 if (!cfs_hash_bd_dec_and_lock(site->ls_obj_hash, &bd, &top->loh_ref)) {
132 if (lu_object_is_dying(top)) {
135 * somebody may be waiting for this, currently only
136 * used for cl_object, see cl_object_put_last().
138 wake_up_all(&bkt->lsb_marche_funebre);
144 * When last reference is released, iterate over object
145 * layers, and notify them that object is no longer busy.
147 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
148 if (o->lo_ops->loo_object_release != NULL)
149 o->lo_ops->loo_object_release(env, o);
152 if (!lu_object_is_dying(top) &&
153 (lu_object_exists(orig) || lu_object_is_cl(orig))) {
154 LASSERT(list_empty(&top->loh_lru));
155 list_add_tail(&top->loh_lru, &bkt->lsb_lru);
157 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
162 * If object is dying (will not be cached) then remove it
163 * from hash table and LRU.
165 * This is done with hash table and LRU lists locked. As the only
166 * way to acquire first reference to previously unreferenced
167 * object is through hash-table lookup (lu_object_find()),
168 * or LRU scanning (lu_site_purge()), that are done under hash-table
169 * and LRU lock, no race with concurrent object lookup is possible
170 * and we can safely destroy object below.
172 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags))
173 cfs_hash_bd_del_locked(site->ls_obj_hash, &bd, &top->loh_hash);
174 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
176 * Object was already removed from hash and lru above, can
179 lu_object_free(env, orig);
181 EXPORT_SYMBOL(lu_object_put);
184 * Put object and don't keep in cache. This is temporary solution for
185 * multi-site objects when its layering is not constant.
187 void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o)
189 set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags);
190 return lu_object_put(env, o);
192 EXPORT_SYMBOL(lu_object_put_nocache);
195 * Kill the object and take it out of LRU cache.
196 * Currently used by client code for layout change.
198 void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
200 struct lu_object_header *top;
203 set_bit(LU_OBJECT_HEARD_BANSHEE, &top->loh_flags);
204 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) {
205 cfs_hash_t *obj_hash = o->lo_dev->ld_site->ls_obj_hash;
208 cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1);
209 if (!list_empty(&top->loh_lru)) {
210 struct lu_site_bkt_data *bkt;
212 list_del_init(&top->loh_lru);
213 bkt = cfs_hash_bd_extra_get(obj_hash, &bd);
216 cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
217 cfs_hash_bd_unlock(obj_hash, &bd, 1);
220 EXPORT_SYMBOL(lu_object_unhash);
223 * Allocate new object.
225 * This follows object creation protocol, described in the comment within
226 * struct lu_device_operations definition.
228 static struct lu_object *lu_object_alloc(const struct lu_env *env,
229 struct lu_device *dev,
230 const struct lu_fid *f,
231 const struct lu_object_conf *conf)
233 struct lu_object *scan;
234 struct lu_object *top;
235 struct list_head *layers;
236 unsigned int init_mask = 0;
237 unsigned int init_flag;
243 * Create top-level object slice. This will also create
246 top = dev->ld_ops->ldo_object_alloc(env, NULL, dev);
248 RETURN(ERR_PTR(-ENOMEM));
252 * This is the only place where object fid is assigned. It's constant
255 top->lo_header->loh_fid = *f;
256 layers = &top->lo_header->loh_layers;
260 * Call ->loo_object_init() repeatedly, until no more new
261 * object slices are created.
265 list_for_each_entry(scan, layers, lo_linkage) {
266 if (init_mask & init_flag)
269 scan->lo_header = top->lo_header;
270 result = scan->lo_ops->loo_object_init(env, scan, conf);
272 lu_object_free(env, top);
273 RETURN(ERR_PTR(result));
275 init_mask |= init_flag;
281 list_for_each_entry_reverse(scan, layers, lo_linkage) {
282 if (scan->lo_ops->loo_object_start != NULL) {
283 result = scan->lo_ops->loo_object_start(env, scan);
285 lu_object_free(env, top);
286 RETURN(ERR_PTR(result));
291 lprocfs_counter_incr(dev->ld_site->ls_stats, LU_SS_CREATED);
298 static void lu_object_free(const struct lu_env *env, struct lu_object *o)
300 struct lu_site_bkt_data *bkt;
301 struct lu_site *site;
302 struct lu_object *scan;
303 struct list_head *layers;
304 struct list_head splice;
306 site = o->lo_dev->ld_site;
307 layers = &o->lo_header->loh_layers;
308 bkt = lu_site_bkt_from_fid(site, &o->lo_header->loh_fid);
310 * First call ->loo_object_delete() method to release all resources.
312 list_for_each_entry_reverse(scan, layers, lo_linkage) {
313 if (scan->lo_ops->loo_object_delete != NULL)
314 scan->lo_ops->loo_object_delete(env, scan);
318 * Then, splice object layers into stand-alone list, and call
319 * ->loo_object_free() on all layers to free memory. Splice is
320 * necessary, because lu_object_header is freed together with the
323 INIT_LIST_HEAD(&splice);
324 list_splice_init(layers, &splice);
325 while (!list_empty(&splice)) {
327 * Free layers in bottom-to-top order, so that object header
328 * lives as long as possible and ->loo_object_free() methods
329 * can look at its contents.
331 o = container_of0(splice.prev, struct lu_object, lo_linkage);
332 list_del_init(&o->lo_linkage);
333 LASSERT(o->lo_ops->loo_object_free != NULL);
334 o->lo_ops->loo_object_free(env, o);
337 if (waitqueue_active(&bkt->lsb_marche_funebre))
338 wake_up_all(&bkt->lsb_marche_funebre);
342 * Free \a nr objects from the cold end of the site LRU list.
344 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
346 struct lu_object_header *h;
347 struct lu_object_header *temp;
348 struct lu_site_bkt_data *bkt;
351 struct list_head dispose;
358 if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU))
361 INIT_LIST_HEAD(&dispose);
363 * Under LRU list lock, scan LRU list and move unreferenced objects to
364 * the dispose list, removing them from LRU and hash table.
366 start = s->ls_purge_start;
367 bnr = (nr == ~0) ? -1 : nr / (int)CFS_HASH_NBKT(s->ls_obj_hash) + 1;
370 * It doesn't make any sense to make purge threads parallel, that can
371 * only bring troubles to us. See LU-5331.
373 mutex_lock(&s->ls_purge_mutex);
375 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
379 cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1);
380 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
382 list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) {
383 LASSERT(atomic_read(&h->loh_ref) == 0);
385 cfs_hash_bd_get(s->ls_obj_hash, &h->loh_fid, &bd2);
386 LASSERT(bd.bd_bucket == bd2.bd_bucket);
388 cfs_hash_bd_del_locked(s->ls_obj_hash,
390 list_move(&h->loh_lru, &dispose);
395 if (nr != ~0 && --nr == 0)
398 if (count > 0 && --count == 0)
402 cfs_hash_bd_unlock(s->ls_obj_hash, &bd, 1);
405 * Free everything on the dispose list. This is safe against
406 * races due to the reasons described in lu_object_put().
408 while (!list_empty(&dispose)) {
409 h = container_of0(dispose.next,
410 struct lu_object_header, loh_lru);
411 list_del_init(&h->loh_lru);
412 lu_object_free(env, lu_object_top(h));
413 lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED);
419 mutex_unlock(&s->ls_purge_mutex);
421 if (nr != 0 && did_sth && start != 0) {
422 start = 0; /* restart from the first bucket */
425 /* race on s->ls_purge_start, but nobody cares */
426 s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash);
430 EXPORT_SYMBOL(lu_site_purge);
435 * Code below has to jump through certain loops to output object description
436 * into libcfs_debug_msg-based log. The problem is that lu_object_print()
437 * composes object description from strings that are parts of _lines_ of
438 * output (i.e., strings that are not terminated by newline). This doesn't fit
439 * very well into libcfs_debug_msg() interface that assumes that each message
440 * supplied to it is a self-contained output line.
442 * To work around this, strings are collected in a temporary buffer
443 * (implemented as a value of lu_cdebug_key key), until terminating newline
444 * character is detected.
452 * XXX overflow is not handled correctly.
457 struct lu_cdebug_data {
461 char lck_area[LU_CDEBUG_LINE];
464 /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
465 LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data);
468 * Key, holding temporary buffer. This key is registered very early by
471 static struct lu_context_key lu_global_key = {
472 .lct_tags = LCT_MD_THREAD | LCT_DT_THREAD |
473 LCT_MG_THREAD | LCT_CL_THREAD | LCT_LOCAL,
474 .lct_init = lu_global_key_init,
475 .lct_fini = lu_global_key_fini
479 * Printer function emitting messages through libcfs_debug_msg().
481 int lu_cdebug_printer(const struct lu_env *env,
482 void *cookie, const char *format, ...)
484 struct libcfs_debug_msg_data *msgdata = cookie;
485 struct lu_cdebug_data *key;
490 va_start(args, format);
492 key = lu_context_key_get(&env->le_ctx, &lu_global_key);
493 LASSERT(key != NULL);
495 used = strlen(key->lck_area);
496 complete = format[strlen(format) - 1] == '\n';
498 * Append new chunk to the buffer.
500 vsnprintf(key->lck_area + used,
501 ARRAY_SIZE(key->lck_area) - used, format, args);
503 if (cfs_cdebug_show(msgdata->msg_mask, msgdata->msg_subsys))
504 libcfs_debug_msg(msgdata, "%s\n", key->lck_area);
505 key->lck_area[0] = 0;
510 EXPORT_SYMBOL(lu_cdebug_printer);
513 * Print object header.
515 void lu_object_header_print(const struct lu_env *env, void *cookie,
516 lu_printer_t printer,
517 const struct lu_object_header *hdr)
519 (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
520 hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
522 hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
523 list_empty((struct list_head *)&hdr->loh_lru) ? \
525 hdr->loh_attr & LOHA_EXISTS ? " exist" : "");
527 EXPORT_SYMBOL(lu_object_header_print);
530 * Print human readable representation of the \a o to the \a printer.
532 void lu_object_print(const struct lu_env *env, void *cookie,
533 lu_printer_t printer, const struct lu_object *o)
535 static const char ruler[] = "........................................";
536 struct lu_object_header *top;
540 lu_object_header_print(env, cookie, printer, top);
541 (*printer)(env, cookie, "{\n");
543 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
545 * print `.' \a depth times followed by type name and address
547 (*printer)(env, cookie, "%*.*s%s@%p", depth, depth, ruler,
548 o->lo_dev->ld_type->ldt_name, o);
550 if (o->lo_ops->loo_object_print != NULL)
551 (*o->lo_ops->loo_object_print)(env, cookie, printer, o);
553 (*printer)(env, cookie, "\n");
556 (*printer)(env, cookie, "} header@%p\n", top);
558 EXPORT_SYMBOL(lu_object_print);
561 * Check object consistency.
563 int lu_object_invariant(const struct lu_object *o)
565 struct lu_object_header *top;
568 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
569 if (o->lo_ops->loo_object_invariant != NULL &&
570 !o->lo_ops->loo_object_invariant(o))
576 static struct lu_object *htable_lookup(struct lu_site *s,
578 const struct lu_fid *f,
579 wait_queue_t *waiter,
582 struct lu_site_bkt_data *bkt;
583 struct lu_object_header *h;
584 struct hlist_node *hnode;
585 __u64 ver = cfs_hash_bd_version_get(bd);
588 return ERR_PTR(-ENOENT);
591 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, bd);
592 /* cfs_hash_bd_peek_locked is a somehow "internal" function
593 * of cfs_hash, it doesn't add refcount on object. */
594 hnode = cfs_hash_bd_peek_locked(s->ls_obj_hash, bd, (void *)f);
596 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_MISS);
597 return ERR_PTR(-ENOENT);
600 h = container_of0(hnode, struct lu_object_header, loh_hash);
601 if (likely(!lu_object_is_dying(h))) {
602 cfs_hash_get(s->ls_obj_hash, hnode);
603 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT);
604 if (!list_empty(&h->loh_lru)) {
605 list_del_init(&h->loh_lru);
608 return lu_object_top(h);
612 * Lookup found an object being destroyed this object cannot be
613 * returned (to assure that references to dying objects are eventually
614 * drained), and moreover, lookup has to wait until object is freed.
617 if (likely(waiter != NULL)) {
618 init_waitqueue_entry_current(waiter);
619 add_wait_queue(&bkt->lsb_marche_funebre, waiter);
620 set_current_state(TASK_UNINTERRUPTIBLE);
621 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE);
624 return ERR_PTR(-EAGAIN);
628 * Search cache for an object with the fid \a f. If such object is found,
629 * return it. Otherwise, create new object, insert it into cache and return
630 * it. In any case, additional reference is acquired on the returned object.
632 struct lu_object *lu_object_find(const struct lu_env *env,
633 struct lu_device *dev, const struct lu_fid *f,
634 const struct lu_object_conf *conf)
636 return lu_object_find_at(env, dev->ld_site->ls_top_dev, f, conf);
638 EXPORT_SYMBOL(lu_object_find);
641 * Limit the lu_object cache to a maximum of lu_cache_nr objects. Because
642 * the calculation for the number of objects to reclaim is not covered by
643 * a lock the maximum number of objects is capped by LU_CACHE_MAX_ADJUST.
644 * This ensures that many concurrent threads will not accidentally purge
647 static void lu_object_limit(const struct lu_env *env,
648 struct lu_device *dev)
652 if (lu_cache_nr == LU_CACHE_NR_UNLIMITED)
655 size = cfs_hash_size_get(dev->ld_site->ls_obj_hash);
656 nr = (__u64)lu_cache_nr;
658 lu_site_purge(env, dev->ld_site,
659 MIN(size - nr, LU_CACHE_NR_MAX_ADJUST));
664 static struct lu_object *lu_object_new(const struct lu_env *env,
665 struct lu_device *dev,
666 const struct lu_fid *f,
667 const struct lu_object_conf *conf)
673 o = lu_object_alloc(env, dev, f, conf);
674 if (unlikely(IS_ERR(o)))
677 hs = dev->ld_site->ls_obj_hash;
678 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
679 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
680 cfs_hash_bd_unlock(hs, &bd, 1);
682 lu_object_limit(env, dev);
688 * Core logic of lu_object_find*() functions.
690 static struct lu_object *lu_object_find_try(const struct lu_env *env,
691 struct lu_device *dev,
692 const struct lu_fid *f,
693 const struct lu_object_conf *conf,
694 wait_queue_t *waiter)
697 struct lu_object *shadow;
704 * This uses standard index maintenance protocol:
706 * - search index under lock, and return object if found;
707 * - otherwise, unlock index, allocate new object;
708 * - lock index and search again;
709 * - if nothing is found (usual case), insert newly created
711 * - otherwise (race: other thread inserted object), free
712 * object just allocated.
716 * For "LOC_F_NEW" case, we are sure the object is new established.
717 * It is unnecessary to perform lookup-alloc-lookup-insert, instead,
718 * just alloc and insert directly.
720 * If dying object is found during index search, add @waiter to the
721 * site wait-queue and return ERR_PTR(-EAGAIN).
723 if (conf != NULL && conf->loc_flags & LOC_F_NEW)
724 return lu_object_new(env, dev, f, conf);
728 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
729 o = htable_lookup(s, &bd, f, waiter, &version);
730 cfs_hash_bd_unlock(hs, &bd, 1);
731 if (!IS_ERR(o) || PTR_ERR(o) != -ENOENT)
735 * Allocate new object. This may result in rather complicated
736 * operations, including fld queries, inode loading, etc.
738 o = lu_object_alloc(env, dev, f, conf);
739 if (unlikely(IS_ERR(o)))
742 LASSERT(lu_fid_eq(lu_object_fid(o), f));
744 cfs_hash_bd_lock(hs, &bd, 1);
746 shadow = htable_lookup(s, &bd, f, waiter, &version);
747 if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) {
748 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
749 cfs_hash_bd_unlock(hs, &bd, 1);
751 lu_object_limit(env, dev);
756 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_RACE);
757 cfs_hash_bd_unlock(hs, &bd, 1);
758 lu_object_free(env, o);
763 * Much like lu_object_find(), but top level device of object is specifically
764 * \a dev rather than top level device of the site. This interface allows
765 * objects of different "stacking" to be created within the same site.
767 struct lu_object *lu_object_find_at(const struct lu_env *env,
768 struct lu_device *dev,
769 const struct lu_fid *f,
770 const struct lu_object_conf *conf)
772 struct lu_site_bkt_data *bkt;
773 struct lu_object *obj;
776 if (conf != NULL && conf->loc_flags & LOC_F_NOWAIT)
777 return lu_object_find_try(env, dev, f, conf, NULL);
780 obj = lu_object_find_try(env, dev, f, conf, &wait);
781 if (obj != ERR_PTR(-EAGAIN))
784 * lu_object_find_try() already added waiter into the
787 waitq_wait(&wait, TASK_UNINTERRUPTIBLE);
788 bkt = lu_site_bkt_from_fid(dev->ld_site, (void *)f);
789 remove_wait_queue(&bkt->lsb_marche_funebre, &wait);
792 EXPORT_SYMBOL(lu_object_find_at);
795 * Find object with given fid, and return its slice belonging to given device.
797 struct lu_object *lu_object_find_slice(const struct lu_env *env,
798 struct lu_device *dev,
799 const struct lu_fid *f,
800 const struct lu_object_conf *conf)
802 struct lu_object *top;
803 struct lu_object *obj;
805 top = lu_object_find(env, dev, f, conf);
809 obj = lu_object_locate(top->lo_header, dev->ld_type);
810 if (unlikely(obj == NULL)) {
811 lu_object_put(env, top);
812 obj = ERR_PTR(-ENOENT);
817 EXPORT_SYMBOL(lu_object_find_slice);
820 * Global list of all device types.
822 static struct list_head lu_device_types;
824 int lu_device_type_init(struct lu_device_type *ldt)
828 atomic_set(&ldt->ldt_device_nr, 0);
829 INIT_LIST_HEAD(&ldt->ldt_linkage);
830 if (ldt->ldt_ops->ldto_init)
831 result = ldt->ldt_ops->ldto_init(ldt);
834 spin_lock(&obd_types_lock);
835 list_add(&ldt->ldt_linkage, &lu_device_types);
836 spin_unlock(&obd_types_lock);
841 EXPORT_SYMBOL(lu_device_type_init);
843 void lu_device_type_fini(struct lu_device_type *ldt)
845 spin_lock(&obd_types_lock);
846 list_del_init(&ldt->ldt_linkage);
847 spin_unlock(&obd_types_lock);
848 if (ldt->ldt_ops->ldto_fini)
849 ldt->ldt_ops->ldto_fini(ldt);
851 EXPORT_SYMBOL(lu_device_type_fini);
854 * Global list of all sites on this node
856 static struct list_head lu_sites;
857 static DEFINE_MUTEX(lu_sites_guard);
860 * Global environment used by site shrinker.
862 static struct lu_env lu_shrink_env;
864 struct lu_site_print_arg {
865 struct lu_env *lsp_env;
867 lu_printer_t lsp_printer;
871 lu_site_obj_print(cfs_hash_t *hs, cfs_hash_bd_t *bd,
872 struct hlist_node *hnode, void *data)
874 struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
875 struct lu_object_header *h;
877 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
878 if (!list_empty(&h->loh_layers)) {
879 const struct lu_object *o;
881 o = lu_object_top(h);
882 lu_object_print(arg->lsp_env, arg->lsp_cookie,
883 arg->lsp_printer, o);
885 lu_object_header_print(arg->lsp_env, arg->lsp_cookie,
886 arg->lsp_printer, h);
892 * Print all objects in \a s.
894 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
895 lu_printer_t printer)
897 struct lu_site_print_arg arg = {
898 .lsp_env = (struct lu_env *)env,
899 .lsp_cookie = cookie,
900 .lsp_printer = printer,
903 cfs_hash_for_each(s->ls_obj_hash, lu_site_obj_print, &arg);
905 EXPORT_SYMBOL(lu_site_print);
908 * Return desired hash table order.
910 static unsigned long lu_htable_order(struct lu_device *top)
912 unsigned long cache_size;
916 * For ZFS based OSDs the cache should be disabled by default. This
917 * allows the ZFS ARC maximum flexibility in determining what buffers
918 * to cache. If Lustre has objects or buffer which it wants to ensure
919 * always stay cached it must maintain a hold on them.
921 if (strcmp(top->ld_type->ldt_name, LUSTRE_OSD_ZFS_NAME) == 0) {
922 lu_cache_percent = 1;
923 lu_cache_nr = LU_CACHE_NR_ZFS_LIMIT;
924 return LU_SITE_BITS_MIN;
928 * Calculate hash table size, assuming that we want reasonable
929 * performance when 20% of total memory is occupied by cache of
932 * Size of lu_object is (arbitrary) taken as 1K (together with inode).
934 cache_size = totalram_pages;
936 #if BITS_PER_LONG == 32
937 /* limit hashtable size for lowmem systems to low RAM */
938 if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT))
939 cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4;
942 /* clear off unreasonable cache setting. */
943 if (lu_cache_percent == 0 || lu_cache_percent > LU_CACHE_PERCENT_MAX) {
944 CWARN("obdclass: invalid lu_cache_percent: %u, it must be in"
945 " the range of (0, %u]. Will use default value: %u.\n",
946 lu_cache_percent, LU_CACHE_PERCENT_MAX,
947 LU_CACHE_PERCENT_DEFAULT);
949 lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
951 cache_size = cache_size / 100 * lu_cache_percent *
952 (PAGE_CACHE_SIZE / 1024);
954 for (bits = 1; (1 << bits) < cache_size; ++bits) {
960 static unsigned lu_obj_hop_hash(cfs_hash_t *hs,
961 const void *key, unsigned mask)
963 struct lu_fid *fid = (struct lu_fid *)key;
966 hash = fid_flatten32(fid);
967 hash += (hash >> 4) + (hash << 12); /* mixing oid and seq */
968 hash = hash_long(hash, hs->hs_bkt_bits);
970 /* give me another random factor */
971 hash -= hash_long((unsigned long)hs, fid_oid(fid) % 11 + 3);
973 hash <<= hs->hs_cur_bits - hs->hs_bkt_bits;
974 hash |= (fid_seq(fid) + fid_oid(fid)) & (CFS_HASH_NBKT(hs) - 1);
979 static void *lu_obj_hop_object(struct hlist_node *hnode)
981 return hlist_entry(hnode, struct lu_object_header, loh_hash);
984 static void *lu_obj_hop_key(struct hlist_node *hnode)
986 struct lu_object_header *h;
988 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
992 static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode)
994 struct lu_object_header *h;
996 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
997 return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key);
1000 static void lu_obj_hop_get(cfs_hash_t *hs, struct hlist_node *hnode)
1002 struct lu_object_header *h;
1004 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
1005 atomic_inc(&h->loh_ref);
1008 static void lu_obj_hop_put_locked(cfs_hash_t *hs, struct hlist_node *hnode)
1010 LBUG(); /* we should never called it */
1013 static cfs_hash_ops_t lu_site_hash_ops = {
1014 .hs_hash = lu_obj_hop_hash,
1015 .hs_key = lu_obj_hop_key,
1016 .hs_keycmp = lu_obj_hop_keycmp,
1017 .hs_object = lu_obj_hop_object,
1018 .hs_get = lu_obj_hop_get,
1019 .hs_put_locked = lu_obj_hop_put_locked,
1022 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d)
1024 spin_lock(&s->ls_ld_lock);
1025 if (list_empty(&d->ld_linkage))
1026 list_add(&d->ld_linkage, &s->ls_ld_linkage);
1027 spin_unlock(&s->ls_ld_lock);
1029 EXPORT_SYMBOL(lu_dev_add_linkage);
1031 void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d)
1033 spin_lock(&s->ls_ld_lock);
1034 list_del_init(&d->ld_linkage);
1035 spin_unlock(&s->ls_ld_lock);
1037 EXPORT_SYMBOL(lu_dev_del_linkage);
1040 * Initialize site \a s, with \a d as the top level device.
1042 int lu_site_init(struct lu_site *s, struct lu_device *top)
1044 struct lu_site_bkt_data *bkt;
1051 memset(s, 0, sizeof *s);
1052 mutex_init(&s->ls_purge_mutex);
1053 bits = lu_htable_order(top);
1054 snprintf(name, sizeof(name), "lu_site_%s", top->ld_type->ldt_name);
1055 for (bits = clamp_t(typeof(bits), bits,
1056 LU_SITE_BITS_MIN, LU_SITE_BITS_MAX);
1057 bits >= LU_SITE_BITS_MIN; bits--) {
1058 s->ls_obj_hash = cfs_hash_create(name, bits, bits,
1059 bits - LU_SITE_BKT_BITS,
1062 CFS_HASH_SPIN_BKTLOCK |
1063 CFS_HASH_NO_ITEMREF |
1065 CFS_HASH_ASSERT_EMPTY |
1067 if (s->ls_obj_hash != NULL)
1071 if (s->ls_obj_hash == NULL) {
1072 CERROR("failed to create lu_site hash with bits: %lu\n", bits);
1076 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
1077 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
1078 INIT_LIST_HEAD(&bkt->lsb_lru);
1079 init_waitqueue_head(&bkt->lsb_marche_funebre);
1082 s->ls_stats = lprocfs_alloc_stats(LU_SS_LAST_STAT, 0);
1083 if (s->ls_stats == NULL) {
1084 cfs_hash_putref(s->ls_obj_hash);
1085 s->ls_obj_hash = NULL;
1089 lprocfs_counter_init(s->ls_stats, LU_SS_CREATED,
1090 0, "created", "created");
1091 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_HIT,
1092 0, "cache_hit", "cache_hit");
1093 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_MISS,
1094 0, "cache_miss", "cache_miss");
1095 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_RACE,
1096 0, "cache_race", "cache_race");
1097 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_DEATH_RACE,
1098 0, "cache_death_race", "cache_death_race");
1099 lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
1100 0, "lru_purged", "lru_purged");
1102 INIT_LIST_HEAD(&s->ls_linkage);
1103 s->ls_top_dev = top;
1106 lu_ref_add(&top->ld_reference, "site-top", s);
1108 INIT_LIST_HEAD(&s->ls_ld_linkage);
1109 spin_lock_init(&s->ls_ld_lock);
1111 lu_dev_add_linkage(s, top);
1115 EXPORT_SYMBOL(lu_site_init);
1118 * Finalize \a s and release its resources.
1120 void lu_site_fini(struct lu_site *s)
1122 mutex_lock(&lu_sites_guard);
1123 list_del_init(&s->ls_linkage);
1124 mutex_unlock(&lu_sites_guard);
1126 if (s->ls_obj_hash != NULL) {
1127 cfs_hash_putref(s->ls_obj_hash);
1128 s->ls_obj_hash = NULL;
1131 if (s->ls_top_dev != NULL) {
1132 s->ls_top_dev->ld_site = NULL;
1133 lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s);
1134 lu_device_put(s->ls_top_dev);
1135 s->ls_top_dev = NULL;
1138 if (s->ls_stats != NULL)
1139 lprocfs_free_stats(&s->ls_stats);
1141 EXPORT_SYMBOL(lu_site_fini);
1144 * Called when initialization of stack for this site is completed.
1146 int lu_site_init_finish(struct lu_site *s)
1149 mutex_lock(&lu_sites_guard);
1150 result = lu_context_refill(&lu_shrink_env.le_ctx);
1152 list_add(&s->ls_linkage, &lu_sites);
1153 mutex_unlock(&lu_sites_guard);
1156 EXPORT_SYMBOL(lu_site_init_finish);
1159 * Acquire additional reference on device \a d
1161 void lu_device_get(struct lu_device *d)
1163 atomic_inc(&d->ld_ref);
1165 EXPORT_SYMBOL(lu_device_get);
1168 * Release reference on device \a d.
1170 void lu_device_put(struct lu_device *d)
1172 LASSERT(atomic_read(&d->ld_ref) > 0);
1173 atomic_dec(&d->ld_ref);
1175 EXPORT_SYMBOL(lu_device_put);
1178 * Initialize device \a d of type \a t.
1180 int lu_device_init(struct lu_device *d, struct lu_device_type *t)
1182 if (atomic_inc_return(&t->ldt_device_nr) == 1 &&
1183 t->ldt_ops->ldto_start != NULL)
1184 t->ldt_ops->ldto_start(t);
1186 memset(d, 0, sizeof *d);
1188 lu_ref_init(&d->ld_reference);
1189 INIT_LIST_HEAD(&d->ld_linkage);
1193 EXPORT_SYMBOL(lu_device_init);
1196 * Finalize device \a d.
1198 void lu_device_fini(struct lu_device *d)
1200 struct lu_device_type *t = d->ld_type;
1202 if (d->ld_obd != NULL) {
1203 d->ld_obd->obd_lu_dev = NULL;
1207 lu_ref_fini(&d->ld_reference);
1208 LASSERTF(atomic_read(&d->ld_ref) == 0,
1209 "Refcount is %u\n", atomic_read(&d->ld_ref));
1210 LASSERT(atomic_read(&t->ldt_device_nr) > 0);
1212 if (atomic_dec_and_test(&t->ldt_device_nr) &&
1213 t->ldt_ops->ldto_stop != NULL)
1214 t->ldt_ops->ldto_stop(t);
1216 EXPORT_SYMBOL(lu_device_fini);
1219 * Initialize object \a o that is part of compound object \a h and was created
1222 int lu_object_init(struct lu_object *o, struct lu_object_header *h,
1223 struct lu_device *d)
1225 memset(o, 0, sizeof(*o));
1229 lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o);
1230 INIT_LIST_HEAD(&o->lo_linkage);
1234 EXPORT_SYMBOL(lu_object_init);
1237 * Finalize object and release its resources.
1239 void lu_object_fini(struct lu_object *o)
1241 struct lu_device *dev = o->lo_dev;
1243 LASSERT(list_empty(&o->lo_linkage));
1246 lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref,
1252 EXPORT_SYMBOL(lu_object_fini);
1255 * Add object \a o as first layer of compound object \a h
1257 * This is typically called by the ->ldo_object_alloc() method of top-level
1260 void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
1262 list_move(&o->lo_linkage, &h->loh_layers);
1264 EXPORT_SYMBOL(lu_object_add_top);
1267 * Add object \a o as a layer of compound object, going after \a before.
1269 * This is typically called by the ->ldo_object_alloc() method of \a
1272 void lu_object_add(struct lu_object *before, struct lu_object *o)
1274 list_move(&o->lo_linkage, &before->lo_linkage);
1276 EXPORT_SYMBOL(lu_object_add);
1279 * Initialize compound object.
1281 int lu_object_header_init(struct lu_object_header *h)
1283 memset(h, 0, sizeof *h);
1284 atomic_set(&h->loh_ref, 1);
1285 INIT_HLIST_NODE(&h->loh_hash);
1286 INIT_LIST_HEAD(&h->loh_lru);
1287 INIT_LIST_HEAD(&h->loh_layers);
1288 lu_ref_init(&h->loh_reference);
1291 EXPORT_SYMBOL(lu_object_header_init);
1294 * Finalize compound object.
1296 void lu_object_header_fini(struct lu_object_header *h)
1298 LASSERT(list_empty(&h->loh_layers));
1299 LASSERT(list_empty(&h->loh_lru));
1300 LASSERT(hlist_unhashed(&h->loh_hash));
1301 lu_ref_fini(&h->loh_reference);
1303 EXPORT_SYMBOL(lu_object_header_fini);
1306 * Given a compound object, find its slice, corresponding to the device type
1309 struct lu_object *lu_object_locate(struct lu_object_header *h,
1310 const struct lu_device_type *dtype)
1312 struct lu_object *o;
1314 list_for_each_entry(o, &h->loh_layers, lo_linkage) {
1315 if (o->lo_dev->ld_type == dtype)
1320 EXPORT_SYMBOL(lu_object_locate);
1323 * Finalize and free devices in the device stack.
1325 * Finalize device stack by purging object cache, and calling
1326 * lu_device_type_operations::ldto_device_fini() and
1327 * lu_device_type_operations::ldto_device_free() on all devices in the stack.
1329 void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
1331 struct lu_site *site = top->ld_site;
1332 struct lu_device *scan;
1333 struct lu_device *next;
1335 lu_site_purge(env, site, ~0);
1336 for (scan = top; scan != NULL; scan = next) {
1337 next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan);
1338 lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init);
1339 lu_device_put(scan);
1343 lu_site_purge(env, site, ~0);
1345 for (scan = top; scan != NULL; scan = next) {
1346 const struct lu_device_type *ldt = scan->ld_type;
1347 struct obd_type *type;
1349 next = ldt->ldt_ops->ldto_device_free(env, scan);
1350 type = ldt->ldt_obd_type;
1353 class_put_type(type);
1360 * Maximal number of tld slots.
1362 LU_CONTEXT_KEY_NR = 40
1365 static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
1367 static DEFINE_SPINLOCK(lu_keys_guard);
1368 static atomic_t lu_key_initing_cnt = ATOMIC_INIT(0);
1371 * Global counter incremented whenever key is registered, unregistered,
1372 * revived or quiesced. This is used to void unnecessary calls to
1373 * lu_context_refill(). No locking is provided, as initialization and shutdown
1374 * are supposed to be externally serialized.
1376 static unsigned key_set_version = 0;
1381 int lu_context_key_register(struct lu_context_key *key)
1386 LASSERT(key->lct_init != NULL);
1387 LASSERT(key->lct_fini != NULL);
1388 LASSERT(key->lct_tags != 0);
1389 LASSERT(key->lct_owner != NULL);
1392 spin_lock(&lu_keys_guard);
1393 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1394 if (lu_keys[i] == NULL) {
1396 atomic_set(&key->lct_used, 1);
1398 lu_ref_init(&key->lct_reference);
1404 spin_unlock(&lu_keys_guard);
1407 EXPORT_SYMBOL(lu_context_key_register);
1409 static void key_fini(struct lu_context *ctx, int index)
1411 if (ctx->lc_value != NULL && ctx->lc_value[index] != NULL) {
1412 struct lu_context_key *key;
1414 key = lu_keys[index];
1415 LASSERT(key != NULL);
1416 LASSERT(key->lct_fini != NULL);
1417 LASSERT(atomic_read(&key->lct_used) > 1);
1419 key->lct_fini(ctx, key, ctx->lc_value[index]);
1420 lu_ref_del(&key->lct_reference, "ctx", ctx);
1421 atomic_dec(&key->lct_used);
1423 LASSERT(key->lct_owner != NULL);
1424 if ((ctx->lc_tags & LCT_NOREF) == 0) {
1425 LINVRNT(module_refcount(key->lct_owner) > 0);
1426 module_put(key->lct_owner);
1428 ctx->lc_value[index] = NULL;
1435 void lu_context_key_degister(struct lu_context_key *key)
1437 LASSERT(atomic_read(&key->lct_used) >= 1);
1438 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1440 lu_context_key_quiesce(key);
1443 spin_lock(&lu_keys_guard);
1444 key_fini(&lu_shrink_env.le_ctx, key->lct_index);
1447 * Wait until all transient contexts referencing this key have
1448 * run lu_context_key::lct_fini() method.
1450 while (atomic_read(&key->lct_used) > 1) {
1451 spin_unlock(&lu_keys_guard);
1452 CDEBUG(D_INFO, "lu_context_key_degister: \"%s\" %p, %d\n",
1453 key->lct_owner ? key->lct_owner->name : "", key,
1454 atomic_read(&key->lct_used));
1456 spin_lock(&lu_keys_guard);
1458 if (lu_keys[key->lct_index]) {
1459 lu_keys[key->lct_index] = NULL;
1460 lu_ref_fini(&key->lct_reference);
1462 spin_unlock(&lu_keys_guard);
1464 LASSERTF(atomic_read(&key->lct_used) == 1,
1465 "key has instances: %d\n",
1466 atomic_read(&key->lct_used));
1468 EXPORT_SYMBOL(lu_context_key_degister);
1471 * Register a number of keys. This has to be called after all keys have been
1472 * initialized by a call to LU_CONTEXT_KEY_INIT().
1474 int lu_context_key_register_many(struct lu_context_key *k, ...)
1476 struct lu_context_key *key = k;
1482 result = lu_context_key_register(key);
1485 key = va_arg(args, struct lu_context_key *);
1486 } while (key != NULL);
1492 lu_context_key_degister(k);
1493 k = va_arg(args, struct lu_context_key *);
1500 EXPORT_SYMBOL(lu_context_key_register_many);
1503 * De-register a number of keys. This is a dual to
1504 * lu_context_key_register_many().
1506 void lu_context_key_degister_many(struct lu_context_key *k, ...)
1512 lu_context_key_degister(k);
1513 k = va_arg(args, struct lu_context_key*);
1514 } while (k != NULL);
1517 EXPORT_SYMBOL(lu_context_key_degister_many);
1520 * Revive a number of keys.
1522 void lu_context_key_revive_many(struct lu_context_key *k, ...)
1528 lu_context_key_revive(k);
1529 k = va_arg(args, struct lu_context_key*);
1530 } while (k != NULL);
1533 EXPORT_SYMBOL(lu_context_key_revive_many);
1536 * Quiescent a number of keys.
1538 void lu_context_key_quiesce_many(struct lu_context_key *k, ...)
1544 lu_context_key_quiesce(k);
1545 k = va_arg(args, struct lu_context_key*);
1546 } while (k != NULL);
1549 EXPORT_SYMBOL(lu_context_key_quiesce_many);
1552 * Return value associated with key \a key in context \a ctx.
1554 void *lu_context_key_get(const struct lu_context *ctx,
1555 const struct lu_context_key *key)
1557 LINVRNT(ctx->lc_state == LCS_ENTERED);
1558 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1559 LASSERT(lu_keys[key->lct_index] == key);
1560 return ctx->lc_value[key->lct_index];
1562 EXPORT_SYMBOL(lu_context_key_get);
1565 * List of remembered contexts. XXX document me.
1567 static struct list_head lu_context_remembered;
1570 * Destroy \a key in all remembered contexts. This is used to destroy key
1571 * values in "shared" contexts (like service threads), when a module owning
1572 * the key is about to be unloaded.
1574 void lu_context_key_quiesce(struct lu_context_key *key)
1576 struct lu_context *ctx;
1577 extern unsigned cl_env_cache_purge(unsigned nr);
1579 if (!(key->lct_tags & LCT_QUIESCENT)) {
1581 * XXX layering violation.
1583 cl_env_cache_purge(~0);
1585 * XXX memory barrier has to go here.
1587 spin_lock(&lu_keys_guard);
1588 key->lct_tags |= LCT_QUIESCENT;
1591 * Wait until all lu_context_key::lct_init() methods
1594 while (atomic_read(&lu_key_initing_cnt) > 0) {
1595 spin_unlock(&lu_keys_guard);
1596 CDEBUG(D_INFO, "lu_context_key_quiesce: \"%s\""
1598 key->lct_owner ? key->lct_owner->name : "",
1599 key, atomic_read(&key->lct_used),
1600 atomic_read(&lu_key_initing_cnt));
1602 spin_lock(&lu_keys_guard);
1605 list_for_each_entry(ctx, &lu_context_remembered,
1607 key_fini(ctx, key->lct_index);
1608 spin_unlock(&lu_keys_guard);
1613 void lu_context_key_revive(struct lu_context_key *key)
1615 key->lct_tags &= ~LCT_QUIESCENT;
1619 static void keys_fini(struct lu_context *ctx)
1623 if (ctx->lc_value == NULL)
1626 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i)
1629 OBD_FREE(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1630 ctx->lc_value = NULL;
1633 static int keys_fill(struct lu_context *ctx)
1638 * A serialisation with lu_context_key_quiesce() is needed, but some
1639 * "key->lct_init()" are calling kernel memory allocation routine and
1640 * can't be called while holding a spin_lock.
1641 * "lu_keys_guard" is held while incrementing "lu_key_initing_cnt"
1642 * to ensure the start of the serialisation.
1643 * An atomic_t variable is still used, in order not to reacquire the
1644 * lock when decrementing the counter.
1646 spin_lock(&lu_keys_guard);
1647 atomic_inc(&lu_key_initing_cnt);
1648 spin_unlock(&lu_keys_guard);
1650 LINVRNT(ctx->lc_value != NULL);
1651 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1652 struct lu_context_key *key;
1655 if (ctx->lc_value[i] == NULL && key != NULL &&
1656 (key->lct_tags & ctx->lc_tags) &&
1658 * Don't create values for a LCT_QUIESCENT key, as this
1659 * will pin module owning a key.
1661 !(key->lct_tags & LCT_QUIESCENT)) {
1664 LINVRNT(key->lct_init != NULL);
1665 LINVRNT(key->lct_index == i);
1667 LASSERT(key->lct_owner != NULL);
1668 if (!(ctx->lc_tags & LCT_NOREF) &&
1669 try_module_get(key->lct_owner) == 0) {
1670 /* module is unloading, skip this key */
1674 value = key->lct_init(ctx, key);
1675 if (unlikely(IS_ERR(value))) {
1676 atomic_dec(&lu_key_initing_cnt);
1677 return PTR_ERR(value);
1680 lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
1681 atomic_inc(&key->lct_used);
1683 * This is the only place in the code, where an
1684 * element of ctx->lc_value[] array is set to non-NULL
1687 ctx->lc_value[i] = value;
1688 if (key->lct_exit != NULL)
1689 ctx->lc_tags |= LCT_HAS_EXIT;
1691 ctx->lc_version = key_set_version;
1693 atomic_dec(&lu_key_initing_cnt);
1697 static int keys_init(struct lu_context *ctx)
1699 OBD_ALLOC(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1700 if (likely(ctx->lc_value != NULL))
1701 return keys_fill(ctx);
1707 * Initialize context data-structure. Create values for all keys.
1709 int lu_context_init(struct lu_context *ctx, __u32 tags)
1713 memset(ctx, 0, sizeof *ctx);
1714 ctx->lc_state = LCS_INITIALIZED;
1715 ctx->lc_tags = tags;
1716 if (tags & LCT_REMEMBER) {
1717 spin_lock(&lu_keys_guard);
1718 list_add(&ctx->lc_remember, &lu_context_remembered);
1719 spin_unlock(&lu_keys_guard);
1721 INIT_LIST_HEAD(&ctx->lc_remember);
1724 rc = keys_init(ctx);
1726 lu_context_fini(ctx);
1730 EXPORT_SYMBOL(lu_context_init);
1733 * Finalize context data-structure. Destroy key values.
1735 void lu_context_fini(struct lu_context *ctx)
1737 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1738 ctx->lc_state = LCS_FINALIZED;
1740 if ((ctx->lc_tags & LCT_REMEMBER) == 0) {
1741 LASSERT(list_empty(&ctx->lc_remember));
1744 } else { /* could race with key degister */
1745 spin_lock(&lu_keys_guard);
1747 list_del_init(&ctx->lc_remember);
1748 spin_unlock(&lu_keys_guard);
1751 EXPORT_SYMBOL(lu_context_fini);
1754 * Called before entering context.
1756 void lu_context_enter(struct lu_context *ctx)
1758 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1759 ctx->lc_state = LCS_ENTERED;
1761 EXPORT_SYMBOL(lu_context_enter);
1764 * Called after exiting from \a ctx
1766 void lu_context_exit(struct lu_context *ctx)
1770 LINVRNT(ctx->lc_state == LCS_ENTERED);
1771 ctx->lc_state = LCS_LEFT;
1772 if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
1773 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1774 /* could race with key quiescency */
1775 if (ctx->lc_tags & LCT_REMEMBER)
1776 spin_lock(&lu_keys_guard);
1777 if (ctx->lc_value[i] != NULL) {
1778 struct lu_context_key *key;
1781 LASSERT(key != NULL);
1782 if (key->lct_exit != NULL)
1784 key, ctx->lc_value[i]);
1786 if (ctx->lc_tags & LCT_REMEMBER)
1787 spin_unlock(&lu_keys_guard);
1791 EXPORT_SYMBOL(lu_context_exit);
1794 * Allocate for context all missing keys that were registered after context
1795 * creation. key_set_version is only changed in rare cases when modules
1796 * are loaded and removed.
1798 int lu_context_refill(struct lu_context *ctx)
1800 return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);
1804 * lu_ctx_tags/lu_ses_tags will be updated if there are new types of
1805 * obd being added. Currently, this is only used on client side, specifically
1806 * for echo device client, for other stack (like ptlrpc threads), context are
1807 * predefined when the lu_device type are registered, during the module probe
1810 __u32 lu_context_tags_default = 0;
1811 __u32 lu_session_tags_default = 0;
1813 void lu_context_tags_update(__u32 tags)
1815 spin_lock(&lu_keys_guard);
1816 lu_context_tags_default |= tags;
1818 spin_unlock(&lu_keys_guard);
1820 EXPORT_SYMBOL(lu_context_tags_update);
1822 void lu_context_tags_clear(__u32 tags)
1824 spin_lock(&lu_keys_guard);
1825 lu_context_tags_default &= ~tags;
1827 spin_unlock(&lu_keys_guard);
1829 EXPORT_SYMBOL(lu_context_tags_clear);
1831 void lu_session_tags_update(__u32 tags)
1833 spin_lock(&lu_keys_guard);
1834 lu_session_tags_default |= tags;
1836 spin_unlock(&lu_keys_guard);
1838 EXPORT_SYMBOL(lu_session_tags_update);
1840 void lu_session_tags_clear(__u32 tags)
1842 spin_lock(&lu_keys_guard);
1843 lu_session_tags_default &= ~tags;
1845 spin_unlock(&lu_keys_guard);
1847 EXPORT_SYMBOL(lu_session_tags_clear);
1849 int lu_env_init(struct lu_env *env, __u32 tags)
1854 result = lu_context_init(&env->le_ctx, tags);
1855 if (likely(result == 0))
1856 lu_context_enter(&env->le_ctx);
1859 EXPORT_SYMBOL(lu_env_init);
1861 void lu_env_fini(struct lu_env *env)
1863 lu_context_exit(&env->le_ctx);
1864 lu_context_fini(&env->le_ctx);
1867 EXPORT_SYMBOL(lu_env_fini);
1869 int lu_env_refill(struct lu_env *env)
1873 result = lu_context_refill(&env->le_ctx);
1874 if (result == 0 && env->le_ses != NULL)
1875 result = lu_context_refill(env->le_ses);
1878 EXPORT_SYMBOL(lu_env_refill);
1881 * Currently, this API will only be used by echo client.
1882 * Because echo client and normal lustre client will share
1883 * same cl_env cache. So echo client needs to refresh
1884 * the env context after it get one from the cache, especially
1885 * when normal client and echo client co-exist in the same client.
1887 int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags,
1892 if ((env->le_ctx.lc_tags & ctags) != ctags) {
1893 env->le_ctx.lc_version = 0;
1894 env->le_ctx.lc_tags |= ctags;
1897 if (env->le_ses && (env->le_ses->lc_tags & stags) != stags) {
1898 env->le_ses->lc_version = 0;
1899 env->le_ses->lc_tags |= stags;
1902 result = lu_env_refill(env);
1906 EXPORT_SYMBOL(lu_env_refill_by_tags);
1908 static struct shrinker *lu_site_shrinker;
1910 typedef struct lu_site_stats{
1911 unsigned lss_populated;
1912 unsigned lss_max_search;
1917 static void lu_site_stats_get(cfs_hash_t *hs,
1918 lu_site_stats_t *stats, int populated)
1923 cfs_hash_for_each_bucket(hs, &bd, i) {
1924 struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd);
1925 struct hlist_head *hhead;
1927 cfs_hash_bd_lock(hs, &bd, 1);
1929 cfs_hash_bd_count_get(&bd) - bkt->lsb_lru_len;
1930 stats->lss_total += cfs_hash_bd_count_get(&bd);
1931 stats->lss_max_search = max((int)stats->lss_max_search,
1932 cfs_hash_bd_depmax_get(&bd));
1934 cfs_hash_bd_unlock(hs, &bd, 1);
1938 cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
1939 if (!hlist_empty(hhead))
1940 stats->lss_populated++;
1942 cfs_hash_bd_unlock(hs, &bd, 1);
1947 static unsigned long lu_cache_shrink_count(struct shrinker *sk,
1948 struct shrink_control *sc)
1950 lu_site_stats_t stats;
1952 struct lu_site *tmp;
1953 unsigned long cached = 0;
1955 if (!(sc->gfp_mask & __GFP_FS))
1958 mutex_lock(&lu_sites_guard);
1959 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1960 memset(&stats, 0, sizeof(stats));
1961 lu_site_stats_get(s->ls_obj_hash, &stats, 0);
1962 cached += stats.lss_total - stats.lss_busy;
1964 mutex_unlock(&lu_sites_guard);
1966 cached = (cached / 100) * sysctl_vfs_cache_pressure;
1967 CDEBUG(D_INODE, "%ld objects cached\n", cached);
1971 static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
1972 struct shrink_control *sc)
1975 struct lu_site *tmp;
1976 unsigned long remain = sc->nr_to_scan;
1979 if (!(sc->gfp_mask & __GFP_FS))
1980 /* We must not take the lu_sites_guard lock when
1981 * __GFP_FS is *not* set because of the deadlock
1982 * possibility detailed above. Additionally,
1983 * since we cannot determine the number of
1984 * objects in the cache without taking this
1985 * lock, we're in a particularly tough spot. As
1986 * a result, we'll just lie and say our cache is
1987 * empty. This _should_ be ok, as we can't
1988 * reclaim objects when __GFP_FS is *not* set
1993 mutex_lock(&lu_sites_guard);
1994 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1995 remain = lu_site_purge(&lu_shrink_env, s, remain);
1997 * Move just shrunk site to the tail of site list to
1998 * assure shrinking fairness.
2000 list_move_tail(&s->ls_linkage, &splice);
2002 list_splice(&splice, lu_sites.prev);
2003 mutex_unlock(&lu_sites_guard);
2005 return sc->nr_to_scan - remain;
2008 #ifndef HAVE_SHRINKER_COUNT
2010 * There exists a potential lock inversion deadlock scenario when using
2011 * Lustre on top of ZFS. This occurs between one of ZFS's
2012 * buf_hash_table.ht_lock's, and Lustre's lu_sites_guard lock. Essentially,
2013 * thread A will take the lu_sites_guard lock and sleep on the ht_lock,
2014 * while thread B will take the ht_lock and sleep on the lu_sites_guard
2015 * lock. Obviously neither thread will wake and drop their respective hold
2018 * To prevent this from happening we must ensure the lu_sites_guard lock is
2019 * not taken while down this code path. ZFS reliably does not set the
2020 * __GFP_FS bit in its code paths, so this can be used to determine if it
2021 * is safe to take the lu_sites_guard lock.
2023 * Ideally we should accurately return the remaining number of cached
2024 * objects without taking the lu_sites_guard lock, but this is not
2025 * possible in the current implementation.
2027 static int lu_cache_shrink(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask))
2030 struct shrink_control scv = {
2031 .nr_to_scan = shrink_param(sc, nr_to_scan),
2032 .gfp_mask = shrink_param(sc, gfp_mask)
2034 #if !defined(HAVE_SHRINKER_WANT_SHRINK_PTR) && !defined(HAVE_SHRINK_CONTROL)
2035 struct shrinker* shrinker = NULL;
2039 CDEBUG(D_INODE, "Shrink %lu objects\n", scv.nr_to_scan);
2041 lu_cache_shrink_scan(shrinker, &scv);
2043 cached = lu_cache_shrink_count(shrinker, &scv);
2044 if (scv.nr_to_scan == 0)
2045 CDEBUG(D_INODE, "%d objects cached\n", cached);
2049 #endif /* HAVE_SHRINKER_COUNT */
2057 * Environment to be used in debugger, contains all tags.
2059 static struct lu_env lu_debugging_env;
2062 * Debugging printer function using printk().
2064 int lu_printk_printer(const struct lu_env *env,
2065 void *unused, const char *format, ...)
2069 va_start(args, format);
2070 vprintk(format, args);
2075 int lu_debugging_setup(void)
2077 return lu_env_init(&lu_debugging_env, ~0);
2080 void lu_context_keys_dump(void)
2084 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
2085 struct lu_context_key *key;
2089 CERROR("[%d]: %p %x (%p,%p,%p) %d %d \"%s\"@%p\n",
2090 i, key, key->lct_tags,
2091 key->lct_init, key->lct_fini, key->lct_exit,
2092 key->lct_index, atomic_read(&key->lct_used),
2093 key->lct_owner ? key->lct_owner->name : "",
2095 lu_ref_print(&key->lct_reference);
2101 * Initialization of global lu_* data.
2103 int lu_global_init(void)
2106 DEF_SHRINKER_VAR(shvar, lu_cache_shrink,
2107 lu_cache_shrink_count, lu_cache_shrink_scan);
2109 CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys);
2111 INIT_LIST_HEAD(&lu_device_types);
2112 INIT_LIST_HEAD(&lu_context_remembered);
2113 INIT_LIST_HEAD(&lu_sites);
2115 result = lu_ref_global_init();
2119 LU_CONTEXT_KEY_INIT(&lu_global_key);
2120 result = lu_context_key_register(&lu_global_key);
2125 * At this level, we don't know what tags are needed, so allocate them
2126 * conservatively. This should not be too bad, because this
2127 * environment is global.
2129 mutex_lock(&lu_sites_guard);
2130 result = lu_env_init(&lu_shrink_env, LCT_SHRINKER);
2131 mutex_unlock(&lu_sites_guard);
2136 * seeks estimation: 3 seeks to read a record from oi, one to read
2137 * inode, one for ea. Unfortunately setting this high value results in
2138 * lu_object/inode cache consuming all the memory.
2140 lu_site_shrinker = set_shrinker(DEFAULT_SEEKS, &shvar);
2141 if (lu_site_shrinker == NULL)
2148 * Dual to lu_global_init().
2150 void lu_global_fini(void)
2152 if (lu_site_shrinker != NULL) {
2153 remove_shrinker(lu_site_shrinker);
2154 lu_site_shrinker = NULL;
2157 lu_context_key_degister(&lu_global_key);
2160 * Tear shrinker environment down _after_ de-registering
2161 * lu_global_key, because the latter has a value in the former.
2163 mutex_lock(&lu_sites_guard);
2164 lu_env_fini(&lu_shrink_env);
2165 mutex_unlock(&lu_sites_guard);
2167 lu_ref_global_fini();
2170 static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
2172 #ifdef CONFIG_PROC_FS
2173 struct lprocfs_counter ret;
2175 lprocfs_stats_collect(stats, idx, &ret);
2176 return (__u32)ret.lc_count;
2183 * Output site statistical counters into a buffer. Suitable for
2184 * lprocfs_rd_*()-style functions.
2186 int lu_site_stats_seq_print(const struct lu_site *s, struct seq_file *m)
2188 lu_site_stats_t stats;
2190 memset(&stats, 0, sizeof(stats));
2191 lu_site_stats_get(s->ls_obj_hash, &stats, 1);
2193 return seq_printf(m, "%d/%d %d/%d %d %d %d %d %d %d %d\n",
2196 stats.lss_populated,
2197 CFS_HASH_NHLIST(s->ls_obj_hash),
2198 stats.lss_max_search,
2199 ls_stats_read(s->ls_stats, LU_SS_CREATED),
2200 ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
2201 ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
2202 ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
2203 ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
2204 ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
2206 EXPORT_SYMBOL(lu_site_stats_seq_print);
2208 int lu_site_stats_print(const struct lu_site *s, char *page, int count)
2210 lu_site_stats_t stats;
2212 memset(&stats, 0, sizeof(stats));
2213 lu_site_stats_get(s->ls_obj_hash, &stats, 1);
2215 return snprintf(page, count, "%d/%d %d/%d %d %d %d %d %d %d %d\n",
2218 stats.lss_populated,
2219 CFS_HASH_NHLIST(s->ls_obj_hash),
2220 stats.lss_max_search,
2221 ls_stats_read(s->ls_stats, LU_SS_CREATED),
2222 ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
2223 ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
2224 ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
2225 ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
2226 ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED));
2230 * Helper function to initialize a number of kmem slab caches at once.
2232 int lu_kmem_init(struct lu_kmem_descr *caches)
2235 struct lu_kmem_descr *iter = caches;
2237 for (result = 0; iter->ckd_cache != NULL; ++iter) {
2238 *iter->ckd_cache = kmem_cache_create(iter->ckd_name,
2241 if (*iter->ckd_cache == NULL) {
2243 /* free all previously allocated caches */
2244 lu_kmem_fini(caches);
2250 EXPORT_SYMBOL(lu_kmem_init);
2253 * Helper function to finalize a number of kmem slab cached at once. Dual to
2256 void lu_kmem_fini(struct lu_kmem_descr *caches)
2258 for (; caches->ckd_cache != NULL; ++caches) {
2259 if (*caches->ckd_cache != NULL) {
2260 kmem_cache_destroy(*caches->ckd_cache);
2261 *caches->ckd_cache = NULL;
2265 EXPORT_SYMBOL(lu_kmem_fini);
2268 * Temporary solution to be able to assign fid in ->do_create()
2269 * till we have fully-functional OST fids
2271 void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
2272 const struct lu_fid *fid)
2274 struct lu_site *s = o->lo_dev->ld_site;
2275 struct lu_fid *old = &o->lo_header->loh_fid;
2276 struct lu_object *shadow;
2277 wait_queue_t waiter;
2282 LASSERT(fid_is_zero(old));
2284 hs = s->ls_obj_hash;
2285 cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1);
2286 shadow = htable_lookup(s, &bd, fid, &waiter, &version);
2287 /* supposed to be unique */
2288 LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
2290 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
2291 cfs_hash_bd_unlock(hs, &bd, 1);
2293 EXPORT_SYMBOL(lu_object_assign_fid);
2296 * allocates object with 0 (non-assiged) fid
2297 * XXX: temporary solution to be able to assign fid in ->do_create()
2298 * till we have fully-functional OST fids
2300 struct lu_object *lu_object_anon(const struct lu_env *env,
2301 struct lu_device *dev,
2302 const struct lu_object_conf *conf)
2305 struct lu_object *o;
2308 o = lu_object_alloc(env, dev, &fid, conf);
2312 EXPORT_SYMBOL(lu_object_anon);
2314 struct lu_buf LU_BUF_NULL = {
2318 EXPORT_SYMBOL(LU_BUF_NULL);
2320 void lu_buf_free(struct lu_buf *buf)
2324 LASSERT(buf->lb_len > 0);
2325 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
2330 EXPORT_SYMBOL(lu_buf_free);
2332 void lu_buf_alloc(struct lu_buf *buf, size_t size)
2335 LASSERT(buf->lb_buf == NULL);
2336 LASSERT(buf->lb_len == 0);
2337 OBD_ALLOC_LARGE(buf->lb_buf, size);
2338 if (likely(buf->lb_buf))
2341 EXPORT_SYMBOL(lu_buf_alloc);
2343 void lu_buf_realloc(struct lu_buf *buf, size_t size)
2346 lu_buf_alloc(buf, size);
2348 EXPORT_SYMBOL(lu_buf_realloc);
2350 struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, size_t len)
2352 if (buf->lb_buf == NULL && buf->lb_len == 0)
2353 lu_buf_alloc(buf, len);
2355 if ((len > buf->lb_len) && (buf->lb_buf != NULL))
2356 lu_buf_realloc(buf, len);
2360 EXPORT_SYMBOL(lu_buf_check_and_alloc);
2363 * Increase the size of the \a buf.
2364 * preserves old data in buffer
2365 * old buffer remains unchanged on error
2366 * \retval 0 or -ENOMEM
2368 int lu_buf_check_and_grow(struct lu_buf *buf, size_t len)
2372 if (len <= buf->lb_len)
2375 OBD_ALLOC_LARGE(ptr, len);
2379 /* Free the old buf */
2380 if (buf->lb_buf != NULL) {
2381 memcpy(ptr, buf->lb_buf, buf->lb_len);
2382 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);