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, 2015, 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);
89 static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx);
92 * Decrease reference counter on object. If last reference is freed, return
93 * object to the cache, unless lu_object_is_dying(o) holds. In the latter
94 * case, free object immediately.
96 void lu_object_put(const struct lu_env *env, struct lu_object *o)
98 struct lu_site_bkt_data *bkt;
99 struct lu_object_header *top;
100 struct lu_site *site;
101 struct lu_object *orig;
102 struct cfs_hash_bd bd;
103 const struct lu_fid *fid;
106 site = o->lo_dev->ld_site;
110 * till we have full fids-on-OST implemented anonymous objects
111 * are possible in OSP. such an object isn't listed in the site
112 * so we should not remove it from the site.
114 fid = lu_object_fid(o);
115 if (fid_is_zero(fid)) {
116 LASSERT(top->loh_hash.next == NULL
117 && top->loh_hash.pprev == NULL);
118 LASSERT(list_empty(&top->loh_lru));
119 if (!atomic_dec_and_test(&top->loh_ref))
121 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
122 if (o->lo_ops->loo_object_release != NULL)
123 o->lo_ops->loo_object_release(env, o);
125 lu_object_free(env, orig);
129 cfs_hash_bd_get(site->ls_obj_hash, &top->loh_fid, &bd);
130 bkt = cfs_hash_bd_extra_get(site->ls_obj_hash, &bd);
132 if (!cfs_hash_bd_dec_and_lock(site->ls_obj_hash, &bd, &top->loh_ref)) {
133 if (lu_object_is_dying(top)) {
136 * somebody may be waiting for this, currently only
137 * used for cl_object, see cl_object_put_last().
139 wake_up_all(&bkt->lsb_marche_funebre);
145 * When last reference is released, iterate over object
146 * layers, and notify them that object is no longer busy.
148 list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) {
149 if (o->lo_ops->loo_object_release != NULL)
150 o->lo_ops->loo_object_release(env, o);
153 if (!lu_object_is_dying(top) &&
154 (lu_object_exists(orig) || lu_object_is_cl(orig))) {
155 LASSERT(list_empty(&top->loh_lru));
156 list_add_tail(&top->loh_lru, &bkt->lsb_lru);
158 lprocfs_counter_incr(site->ls_stats, LU_SS_LRU_LEN);
159 CDEBUG(D_INODE, "Add %p to site lru. hash: %p, bkt: %p, "
161 o, site->ls_obj_hash, bkt, bkt->lsb_lru_len);
162 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
167 * If object is dying (will not be cached) then remove it
168 * from hash table and LRU.
170 * This is done with hash table and LRU lists locked. As the only
171 * way to acquire first reference to previously unreferenced
172 * object is through hash-table lookup (lu_object_find()),
173 * or LRU scanning (lu_site_purge()), that are done under hash-table
174 * and LRU lock, no race with concurrent object lookup is possible
175 * and we can safely destroy object below.
177 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags))
178 cfs_hash_bd_del_locked(site->ls_obj_hash, &bd, &top->loh_hash);
179 cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1);
181 * Object was already removed from hash and lru above, can
184 lu_object_free(env, orig);
186 EXPORT_SYMBOL(lu_object_put);
189 * Put object and don't keep in cache. This is temporary solution for
190 * multi-site objects when its layering is not constant.
192 void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o)
194 set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags);
195 return lu_object_put(env, o);
197 EXPORT_SYMBOL(lu_object_put_nocache);
200 * Kill the object and take it out of LRU cache.
201 * Currently used by client code for layout change.
203 void lu_object_unhash(const struct lu_env *env, struct lu_object *o)
205 struct lu_object_header *top;
208 set_bit(LU_OBJECT_HEARD_BANSHEE, &top->loh_flags);
209 if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) {
210 struct lu_site *site = o->lo_dev->ld_site;
211 struct cfs_hash *obj_hash = site->ls_obj_hash;
212 struct cfs_hash_bd bd;
214 cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1);
215 if (!list_empty(&top->loh_lru)) {
216 struct lu_site_bkt_data *bkt;
218 list_del_init(&top->loh_lru);
219 bkt = cfs_hash_bd_extra_get(obj_hash, &bd);
221 lprocfs_counter_decr(site->ls_stats, LU_SS_LRU_LEN);
223 cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash);
224 cfs_hash_bd_unlock(obj_hash, &bd, 1);
227 EXPORT_SYMBOL(lu_object_unhash);
230 * Allocate new object.
232 * This follows object creation protocol, described in the comment within
233 * struct lu_device_operations definition.
235 static struct lu_object *lu_object_alloc(const struct lu_env *env,
236 struct lu_device *dev,
237 const struct lu_fid *f,
238 const struct lu_object_conf *conf)
240 struct lu_object *scan;
241 struct lu_object *top;
242 struct list_head *layers;
243 unsigned int init_mask = 0;
244 unsigned int init_flag;
250 * Create top-level object slice. This will also create
253 top = dev->ld_ops->ldo_object_alloc(env, NULL, dev);
255 RETURN(ERR_PTR(-ENOMEM));
259 * This is the only place where object fid is assigned. It's constant
262 top->lo_header->loh_fid = *f;
263 layers = &top->lo_header->loh_layers;
267 * Call ->loo_object_init() repeatedly, until no more new
268 * object slices are created.
272 list_for_each_entry(scan, layers, lo_linkage) {
273 if (init_mask & init_flag)
276 scan->lo_header = top->lo_header;
277 result = scan->lo_ops->loo_object_init(env, scan, conf);
279 lu_object_free(env, top);
280 RETURN(ERR_PTR(result));
282 init_mask |= init_flag;
288 list_for_each_entry_reverse(scan, layers, lo_linkage) {
289 if (scan->lo_ops->loo_object_start != NULL) {
290 result = scan->lo_ops->loo_object_start(env, scan);
292 lu_object_free(env, top);
293 RETURN(ERR_PTR(result));
298 lprocfs_counter_incr(dev->ld_site->ls_stats, LU_SS_CREATED);
305 static void lu_object_free(const struct lu_env *env, struct lu_object *o)
307 struct lu_site_bkt_data *bkt;
308 struct lu_site *site;
309 struct lu_object *scan;
310 struct list_head *layers;
311 struct list_head splice;
313 site = o->lo_dev->ld_site;
314 layers = &o->lo_header->loh_layers;
315 bkt = lu_site_bkt_from_fid(site, &o->lo_header->loh_fid);
317 * First call ->loo_object_delete() method to release all resources.
319 list_for_each_entry_reverse(scan, layers, lo_linkage) {
320 if (scan->lo_ops->loo_object_delete != NULL)
321 scan->lo_ops->loo_object_delete(env, scan);
325 * Then, splice object layers into stand-alone list, and call
326 * ->loo_object_free() on all layers to free memory. Splice is
327 * necessary, because lu_object_header is freed together with the
330 INIT_LIST_HEAD(&splice);
331 list_splice_init(layers, &splice);
332 while (!list_empty(&splice)) {
334 * Free layers in bottom-to-top order, so that object header
335 * lives as long as possible and ->loo_object_free() methods
336 * can look at its contents.
338 o = container_of0(splice.prev, struct lu_object, lo_linkage);
339 list_del_init(&o->lo_linkage);
340 LASSERT(o->lo_ops->loo_object_free != NULL);
341 o->lo_ops->loo_object_free(env, o);
344 if (waitqueue_active(&bkt->lsb_marche_funebre))
345 wake_up_all(&bkt->lsb_marche_funebre);
349 * Free \a nr objects from the cold end of the site LRU list.
351 int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr)
353 struct lu_object_header *h;
354 struct lu_object_header *temp;
355 struct lu_site_bkt_data *bkt;
356 struct cfs_hash_bd bd;
357 struct cfs_hash_bd bd2;
358 struct list_head dispose;
365 if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU))
368 INIT_LIST_HEAD(&dispose);
370 * Under LRU list lock, scan LRU list and move unreferenced objects to
371 * the dispose list, removing them from LRU and hash table.
373 start = s->ls_purge_start;
374 bnr = (nr == ~0) ? -1 : nr / (int)CFS_HASH_NBKT(s->ls_obj_hash) + 1;
377 * It doesn't make any sense to make purge threads parallel, that can
378 * only bring troubles to us. See LU-5331.
380 mutex_lock(&s->ls_purge_mutex);
382 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
386 cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1);
387 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
389 list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) {
390 LASSERT(atomic_read(&h->loh_ref) == 0);
392 cfs_hash_bd_get(s->ls_obj_hash, &h->loh_fid, &bd2);
393 LASSERT(bd.bd_bucket == bd2.bd_bucket);
395 cfs_hash_bd_del_locked(s->ls_obj_hash,
397 list_move(&h->loh_lru, &dispose);
399 lprocfs_counter_decr(s->ls_stats, LU_SS_LRU_LEN);
403 if (nr != ~0 && --nr == 0)
406 if (count > 0 && --count == 0)
410 cfs_hash_bd_unlock(s->ls_obj_hash, &bd, 1);
413 * Free everything on the dispose list. This is safe against
414 * races due to the reasons described in lu_object_put().
416 while (!list_empty(&dispose)) {
417 h = container_of0(dispose.next,
418 struct lu_object_header, loh_lru);
419 list_del_init(&h->loh_lru);
420 lu_object_free(env, lu_object_top(h));
421 lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED);
427 mutex_unlock(&s->ls_purge_mutex);
429 if (nr != 0 && did_sth && start != 0) {
430 start = 0; /* restart from the first bucket */
433 /* race on s->ls_purge_start, but nobody cares */
434 s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash);
438 EXPORT_SYMBOL(lu_site_purge);
443 * Code below has to jump through certain loops to output object description
444 * into libcfs_debug_msg-based log. The problem is that lu_object_print()
445 * composes object description from strings that are parts of _lines_ of
446 * output (i.e., strings that are not terminated by newline). This doesn't fit
447 * very well into libcfs_debug_msg() interface that assumes that each message
448 * supplied to it is a self-contained output line.
450 * To work around this, strings are collected in a temporary buffer
451 * (implemented as a value of lu_cdebug_key key), until terminating newline
452 * character is detected.
460 * XXX overflow is not handled correctly.
465 struct lu_cdebug_data {
469 char lck_area[LU_CDEBUG_LINE];
472 /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
473 LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data);
476 * Key, holding temporary buffer. This key is registered very early by
479 static struct lu_context_key lu_global_key = {
480 .lct_tags = LCT_MD_THREAD | LCT_DT_THREAD |
481 LCT_MG_THREAD | LCT_CL_THREAD | LCT_LOCAL,
482 .lct_init = lu_global_key_init,
483 .lct_fini = lu_global_key_fini
487 * Printer function emitting messages through libcfs_debug_msg().
489 int lu_cdebug_printer(const struct lu_env *env,
490 void *cookie, const char *format, ...)
492 struct libcfs_debug_msg_data *msgdata = cookie;
493 struct lu_cdebug_data *key;
498 va_start(args, format);
500 key = lu_context_key_get(&env->le_ctx, &lu_global_key);
501 LASSERT(key != NULL);
503 used = strlen(key->lck_area);
504 complete = format[strlen(format) - 1] == '\n';
506 * Append new chunk to the buffer.
508 vsnprintf(key->lck_area + used,
509 ARRAY_SIZE(key->lck_area) - used, format, args);
511 if (cfs_cdebug_show(msgdata->msg_mask, msgdata->msg_subsys))
512 libcfs_debug_msg(msgdata, "%s\n", key->lck_area);
513 key->lck_area[0] = 0;
518 EXPORT_SYMBOL(lu_cdebug_printer);
521 * Print object header.
523 void lu_object_header_print(const struct lu_env *env, void *cookie,
524 lu_printer_t printer,
525 const struct lu_object_header *hdr)
527 (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]",
528 hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref),
530 hlist_unhashed(&hdr->loh_hash) ? "" : " hash",
531 list_empty((struct list_head *)&hdr->loh_lru) ? \
533 hdr->loh_attr & LOHA_EXISTS ? " exist" : "");
535 EXPORT_SYMBOL(lu_object_header_print);
538 * Print human readable representation of the \a o to the \a printer.
540 void lu_object_print(const struct lu_env *env, void *cookie,
541 lu_printer_t printer, const struct lu_object *o)
543 static const char ruler[] = "........................................";
544 struct lu_object_header *top;
548 lu_object_header_print(env, cookie, printer, top);
549 (*printer)(env, cookie, "{\n");
551 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
553 * print `.' \a depth times followed by type name and address
555 (*printer)(env, cookie, "%*.*s%s@%p", depth, depth, ruler,
556 o->lo_dev->ld_type->ldt_name, o);
558 if (o->lo_ops->loo_object_print != NULL)
559 (*o->lo_ops->loo_object_print)(env, cookie, printer, o);
561 (*printer)(env, cookie, "\n");
564 (*printer)(env, cookie, "} header@%p\n", top);
566 EXPORT_SYMBOL(lu_object_print);
569 * Check object consistency.
571 int lu_object_invariant(const struct lu_object *o)
573 struct lu_object_header *top;
576 list_for_each_entry(o, &top->loh_layers, lo_linkage) {
577 if (o->lo_ops->loo_object_invariant != NULL &&
578 !o->lo_ops->loo_object_invariant(o))
584 static struct lu_object *htable_lookup(struct lu_site *s,
585 struct cfs_hash_bd *bd,
586 const struct lu_fid *f,
587 wait_queue_t *waiter,
590 struct lu_site_bkt_data *bkt;
591 struct lu_object_header *h;
592 struct hlist_node *hnode;
593 __u64 ver = cfs_hash_bd_version_get(bd);
596 return ERR_PTR(-ENOENT);
599 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, bd);
600 /* cfs_hash_bd_peek_locked is a somehow "internal" function
601 * of cfs_hash, it doesn't add refcount on object. */
602 hnode = cfs_hash_bd_peek_locked(s->ls_obj_hash, bd, (void *)f);
604 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_MISS);
605 return ERR_PTR(-ENOENT);
608 h = container_of0(hnode, struct lu_object_header, loh_hash);
609 if (likely(!lu_object_is_dying(h))) {
610 cfs_hash_get(s->ls_obj_hash, hnode);
611 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT);
612 if (!list_empty(&h->loh_lru)) {
613 list_del_init(&h->loh_lru);
615 lprocfs_counter_decr(s->ls_stats, LU_SS_LRU_LEN);
617 return lu_object_top(h);
621 * Lookup found an object being destroyed this object cannot be
622 * returned (to assure that references to dying objects are eventually
623 * drained), and moreover, lookup has to wait until object is freed.
626 if (likely(waiter != NULL)) {
627 init_waitqueue_entry(waiter, current);
628 add_wait_queue(&bkt->lsb_marche_funebre, waiter);
629 set_current_state(TASK_UNINTERRUPTIBLE);
630 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE);
633 return ERR_PTR(-EAGAIN);
637 * Search cache for an object with the fid \a f. If such object is found,
638 * return it. Otherwise, create new object, insert it into cache and return
639 * it. In any case, additional reference is acquired on the returned object.
641 struct lu_object *lu_object_find(const struct lu_env *env,
642 struct lu_device *dev, const struct lu_fid *f,
643 const struct lu_object_conf *conf)
645 return lu_object_find_at(env, dev->ld_site->ls_top_dev, f, conf);
647 EXPORT_SYMBOL(lu_object_find);
650 * Limit the lu_object cache to a maximum of lu_cache_nr objects. Because
651 * the calculation for the number of objects to reclaim is not covered by
652 * a lock the maximum number of objects is capped by LU_CACHE_MAX_ADJUST.
653 * This ensures that many concurrent threads will not accidentally purge
656 static void lu_object_limit(const struct lu_env *env,
657 struct lu_device *dev)
661 if (lu_cache_nr == LU_CACHE_NR_UNLIMITED)
664 size = cfs_hash_size_get(dev->ld_site->ls_obj_hash);
665 nr = (__u64)lu_cache_nr;
667 lu_site_purge(env, dev->ld_site,
668 MIN(size - nr, LU_CACHE_NR_MAX_ADJUST));
673 static struct lu_object *lu_object_new(const struct lu_env *env,
674 struct lu_device *dev,
675 const struct lu_fid *f,
676 const struct lu_object_conf *conf)
680 struct cfs_hash_bd bd;
682 o = lu_object_alloc(env, dev, f, conf);
683 if (unlikely(IS_ERR(o)))
686 hs = dev->ld_site->ls_obj_hash;
687 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
688 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
689 cfs_hash_bd_unlock(hs, &bd, 1);
691 lu_object_limit(env, dev);
697 * Core logic of lu_object_find*() functions.
699 static struct lu_object *lu_object_find_try(const struct lu_env *env,
700 struct lu_device *dev,
701 const struct lu_fid *f,
702 const struct lu_object_conf *conf,
703 wait_queue_t *waiter)
706 struct lu_object *shadow;
709 struct cfs_hash_bd bd;
713 * This uses standard index maintenance protocol:
715 * - search index under lock, and return object if found;
716 * - otherwise, unlock index, allocate new object;
717 * - lock index and search again;
718 * - if nothing is found (usual case), insert newly created
720 * - otherwise (race: other thread inserted object), free
721 * object just allocated.
725 * For "LOC_F_NEW" case, we are sure the object is new established.
726 * It is unnecessary to perform lookup-alloc-lookup-insert, instead,
727 * just alloc and insert directly.
729 * If dying object is found during index search, add @waiter to the
730 * site wait-queue and return ERR_PTR(-EAGAIN).
732 if (conf != NULL && conf->loc_flags & LOC_F_NEW)
733 return lu_object_new(env, dev, f, conf);
737 cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1);
738 o = htable_lookup(s, &bd, f, waiter, &version);
739 cfs_hash_bd_unlock(hs, &bd, 1);
740 if (!IS_ERR(o) || PTR_ERR(o) != -ENOENT)
744 * Allocate new object. This may result in rather complicated
745 * operations, including fld queries, inode loading, etc.
747 o = lu_object_alloc(env, dev, f, conf);
748 if (unlikely(IS_ERR(o)))
751 LASSERT(lu_fid_eq(lu_object_fid(o), f));
753 cfs_hash_bd_lock(hs, &bd, 1);
755 shadow = htable_lookup(s, &bd, f, waiter, &version);
756 if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) {
757 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
758 cfs_hash_bd_unlock(hs, &bd, 1);
760 lu_object_limit(env, dev);
765 lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_RACE);
766 cfs_hash_bd_unlock(hs, &bd, 1);
767 lu_object_free(env, o);
772 * Much like lu_object_find(), but top level device of object is specifically
773 * \a dev rather than top level device of the site. This interface allows
774 * objects of different "stacking" to be created within the same site.
776 struct lu_object *lu_object_find_at(const struct lu_env *env,
777 struct lu_device *dev,
778 const struct lu_fid *f,
779 const struct lu_object_conf *conf)
781 struct lu_site_bkt_data *bkt;
782 struct lu_object *obj;
785 if (conf != NULL && conf->loc_flags & LOC_F_NOWAIT)
786 return lu_object_find_try(env, dev, f, conf, NULL);
789 obj = lu_object_find_try(env, dev, f, conf, &wait);
790 if (obj != ERR_PTR(-EAGAIN))
793 * lu_object_find_try() already added waiter into the
797 bkt = lu_site_bkt_from_fid(dev->ld_site, (void *)f);
798 remove_wait_queue(&bkt->lsb_marche_funebre, &wait);
801 EXPORT_SYMBOL(lu_object_find_at);
804 * Find object with given fid, and return its slice belonging to given device.
806 struct lu_object *lu_object_find_slice(const struct lu_env *env,
807 struct lu_device *dev,
808 const struct lu_fid *f,
809 const struct lu_object_conf *conf)
811 struct lu_object *top;
812 struct lu_object *obj;
814 top = lu_object_find(env, dev, f, conf);
818 obj = lu_object_locate(top->lo_header, dev->ld_type);
819 if (unlikely(obj == NULL)) {
820 lu_object_put(env, top);
821 obj = ERR_PTR(-ENOENT);
826 EXPORT_SYMBOL(lu_object_find_slice);
829 * Global list of all device types.
831 static struct list_head lu_device_types;
833 int lu_device_type_init(struct lu_device_type *ldt)
837 atomic_set(&ldt->ldt_device_nr, 0);
838 INIT_LIST_HEAD(&ldt->ldt_linkage);
839 if (ldt->ldt_ops->ldto_init)
840 result = ldt->ldt_ops->ldto_init(ldt);
843 spin_lock(&obd_types_lock);
844 list_add(&ldt->ldt_linkage, &lu_device_types);
845 spin_unlock(&obd_types_lock);
850 EXPORT_SYMBOL(lu_device_type_init);
852 void lu_device_type_fini(struct lu_device_type *ldt)
854 spin_lock(&obd_types_lock);
855 list_del_init(&ldt->ldt_linkage);
856 spin_unlock(&obd_types_lock);
857 if (ldt->ldt_ops->ldto_fini)
858 ldt->ldt_ops->ldto_fini(ldt);
860 EXPORT_SYMBOL(lu_device_type_fini);
863 * Global list of all sites on this node
865 static struct list_head lu_sites;
866 static DEFINE_MUTEX(lu_sites_guard);
869 * Global environment used by site shrinker.
871 static struct lu_env lu_shrink_env;
873 struct lu_site_print_arg {
874 struct lu_env *lsp_env;
876 lu_printer_t lsp_printer;
880 lu_site_obj_print(struct cfs_hash *hs, struct cfs_hash_bd *bd,
881 struct hlist_node *hnode, void *data)
883 struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data;
884 struct lu_object_header *h;
886 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
887 if (!list_empty(&h->loh_layers)) {
888 const struct lu_object *o;
890 o = lu_object_top(h);
891 lu_object_print(arg->lsp_env, arg->lsp_cookie,
892 arg->lsp_printer, o);
894 lu_object_header_print(arg->lsp_env, arg->lsp_cookie,
895 arg->lsp_printer, h);
901 * Print all objects in \a s.
903 void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie,
904 lu_printer_t printer)
906 struct lu_site_print_arg arg = {
907 .lsp_env = (struct lu_env *)env,
908 .lsp_cookie = cookie,
909 .lsp_printer = printer,
912 cfs_hash_for_each(s->ls_obj_hash, lu_site_obj_print, &arg);
914 EXPORT_SYMBOL(lu_site_print);
917 * Return desired hash table order.
919 static unsigned long lu_htable_order(struct lu_device *top)
921 unsigned long cache_size;
925 * For ZFS based OSDs the cache should be disabled by default. This
926 * allows the ZFS ARC maximum flexibility in determining what buffers
927 * to cache. If Lustre has objects or buffer which it wants to ensure
928 * always stay cached it must maintain a hold on them.
930 if (strcmp(top->ld_type->ldt_name, LUSTRE_OSD_ZFS_NAME) == 0) {
931 lu_cache_percent = 1;
932 lu_cache_nr = LU_CACHE_NR_ZFS_LIMIT;
933 return LU_SITE_BITS_MIN;
937 * Calculate hash table size, assuming that we want reasonable
938 * performance when 20% of total memory is occupied by cache of
941 * Size of lu_object is (arbitrary) taken as 1K (together with inode).
943 cache_size = totalram_pages;
945 #if BITS_PER_LONG == 32
946 /* limit hashtable size for lowmem systems to low RAM */
947 if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT))
948 cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4;
951 /* clear off unreasonable cache setting. */
952 if (lu_cache_percent == 0 || lu_cache_percent > LU_CACHE_PERCENT_MAX) {
953 CWARN("obdclass: invalid lu_cache_percent: %u, it must be in"
954 " the range of (0, %u]. Will use default value: %u.\n",
955 lu_cache_percent, LU_CACHE_PERCENT_MAX,
956 LU_CACHE_PERCENT_DEFAULT);
958 lu_cache_percent = LU_CACHE_PERCENT_DEFAULT;
960 cache_size = cache_size / 100 * lu_cache_percent *
961 (PAGE_CACHE_SIZE / 1024);
963 for (bits = 1; (1 << bits) < cache_size; ++bits) {
969 static unsigned lu_obj_hop_hash(struct cfs_hash *hs,
970 const void *key, unsigned mask)
972 struct lu_fid *fid = (struct lu_fid *)key;
975 hash = fid_flatten32(fid);
976 hash += (hash >> 4) + (hash << 12); /* mixing oid and seq */
977 hash = hash_long(hash, hs->hs_bkt_bits);
979 /* give me another random factor */
980 hash -= hash_long((unsigned long)hs, fid_oid(fid) % 11 + 3);
982 hash <<= hs->hs_cur_bits - hs->hs_bkt_bits;
983 hash |= (fid_seq(fid) + fid_oid(fid)) & (CFS_HASH_NBKT(hs) - 1);
988 static void *lu_obj_hop_object(struct hlist_node *hnode)
990 return hlist_entry(hnode, struct lu_object_header, loh_hash);
993 static void *lu_obj_hop_key(struct hlist_node *hnode)
995 struct lu_object_header *h;
997 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
1001 static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode)
1003 struct lu_object_header *h;
1005 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
1006 return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key);
1009 static void lu_obj_hop_get(struct cfs_hash *hs, struct hlist_node *hnode)
1011 struct lu_object_header *h;
1013 h = hlist_entry(hnode, struct lu_object_header, loh_hash);
1014 atomic_inc(&h->loh_ref);
1017 static void lu_obj_hop_put_locked(struct cfs_hash *hs, struct hlist_node *hnode)
1019 LBUG(); /* we should never called it */
1022 static struct cfs_hash_ops lu_site_hash_ops = {
1023 .hs_hash = lu_obj_hop_hash,
1024 .hs_key = lu_obj_hop_key,
1025 .hs_keycmp = lu_obj_hop_keycmp,
1026 .hs_object = lu_obj_hop_object,
1027 .hs_get = lu_obj_hop_get,
1028 .hs_put_locked = lu_obj_hop_put_locked,
1031 void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d)
1033 spin_lock(&s->ls_ld_lock);
1034 if (list_empty(&d->ld_linkage))
1035 list_add(&d->ld_linkage, &s->ls_ld_linkage);
1036 spin_unlock(&s->ls_ld_lock);
1038 EXPORT_SYMBOL(lu_dev_add_linkage);
1040 void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d)
1042 spin_lock(&s->ls_ld_lock);
1043 list_del_init(&d->ld_linkage);
1044 spin_unlock(&s->ls_ld_lock);
1046 EXPORT_SYMBOL(lu_dev_del_linkage);
1049 * Initialize site \a s, with \a d as the top level device.
1051 int lu_site_init(struct lu_site *s, struct lu_device *top)
1053 struct lu_site_bkt_data *bkt;
1054 struct cfs_hash_bd bd;
1060 memset(s, 0, sizeof *s);
1061 mutex_init(&s->ls_purge_mutex);
1062 bits = lu_htable_order(top);
1063 snprintf(name, sizeof(name), "lu_site_%s", top->ld_type->ldt_name);
1064 for (bits = clamp_t(typeof(bits), bits,
1065 LU_SITE_BITS_MIN, LU_SITE_BITS_MAX);
1066 bits >= LU_SITE_BITS_MIN; bits--) {
1067 s->ls_obj_hash = cfs_hash_create(name, bits, bits,
1068 bits - LU_SITE_BKT_BITS,
1071 CFS_HASH_SPIN_BKTLOCK |
1072 CFS_HASH_NO_ITEMREF |
1074 CFS_HASH_ASSERT_EMPTY |
1076 if (s->ls_obj_hash != NULL)
1080 if (s->ls_obj_hash == NULL) {
1081 CERROR("failed to create lu_site hash with bits: %lu\n", bits);
1085 cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) {
1086 bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd);
1087 INIT_LIST_HEAD(&bkt->lsb_lru);
1088 init_waitqueue_head(&bkt->lsb_marche_funebre);
1091 s->ls_stats = lprocfs_alloc_stats(LU_SS_LAST_STAT, 0);
1092 if (s->ls_stats == NULL) {
1093 cfs_hash_putref(s->ls_obj_hash);
1094 s->ls_obj_hash = NULL;
1098 lprocfs_counter_init(s->ls_stats, LU_SS_CREATED,
1099 0, "created", "created");
1100 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_HIT,
1101 0, "cache_hit", "cache_hit");
1102 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_MISS,
1103 0, "cache_miss", "cache_miss");
1104 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_RACE,
1105 0, "cache_race", "cache_race");
1106 lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_DEATH_RACE,
1107 0, "cache_death_race", "cache_death_race");
1108 lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED,
1109 0, "lru_purged", "lru_purged");
1111 * Unlike other counters, lru_len can be decremented so
1112 * need lc_sum instead of just lc_count
1114 lprocfs_counter_init(s->ls_stats, LU_SS_LRU_LEN,
1115 LPROCFS_CNTR_AVGMINMAX, "lru_len", "lru_len");
1117 INIT_LIST_HEAD(&s->ls_linkage);
1118 s->ls_top_dev = top;
1121 lu_ref_add(&top->ld_reference, "site-top", s);
1123 INIT_LIST_HEAD(&s->ls_ld_linkage);
1124 spin_lock_init(&s->ls_ld_lock);
1126 lu_dev_add_linkage(s, top);
1130 EXPORT_SYMBOL(lu_site_init);
1133 * Finalize \a s and release its resources.
1135 void lu_site_fini(struct lu_site *s)
1137 mutex_lock(&lu_sites_guard);
1138 list_del_init(&s->ls_linkage);
1139 mutex_unlock(&lu_sites_guard);
1141 if (s->ls_obj_hash != NULL) {
1142 cfs_hash_putref(s->ls_obj_hash);
1143 s->ls_obj_hash = NULL;
1146 if (s->ls_top_dev != NULL) {
1147 s->ls_top_dev->ld_site = NULL;
1148 lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s);
1149 lu_device_put(s->ls_top_dev);
1150 s->ls_top_dev = NULL;
1153 if (s->ls_stats != NULL)
1154 lprocfs_free_stats(&s->ls_stats);
1156 EXPORT_SYMBOL(lu_site_fini);
1159 * Called when initialization of stack for this site is completed.
1161 int lu_site_init_finish(struct lu_site *s)
1164 mutex_lock(&lu_sites_guard);
1165 result = lu_context_refill(&lu_shrink_env.le_ctx);
1167 list_add(&s->ls_linkage, &lu_sites);
1168 mutex_unlock(&lu_sites_guard);
1171 EXPORT_SYMBOL(lu_site_init_finish);
1174 * Acquire additional reference on device \a d
1176 void lu_device_get(struct lu_device *d)
1178 atomic_inc(&d->ld_ref);
1180 EXPORT_SYMBOL(lu_device_get);
1183 * Release reference on device \a d.
1185 void lu_device_put(struct lu_device *d)
1187 LASSERT(atomic_read(&d->ld_ref) > 0);
1188 atomic_dec(&d->ld_ref);
1190 EXPORT_SYMBOL(lu_device_put);
1193 * Initialize device \a d of type \a t.
1195 int lu_device_init(struct lu_device *d, struct lu_device_type *t)
1197 if (atomic_inc_return(&t->ldt_device_nr) == 1 &&
1198 t->ldt_ops->ldto_start != NULL)
1199 t->ldt_ops->ldto_start(t);
1201 memset(d, 0, sizeof *d);
1203 lu_ref_init(&d->ld_reference);
1204 INIT_LIST_HEAD(&d->ld_linkage);
1208 EXPORT_SYMBOL(lu_device_init);
1211 * Finalize device \a d.
1213 void lu_device_fini(struct lu_device *d)
1215 struct lu_device_type *t = d->ld_type;
1217 if (d->ld_obd != NULL) {
1218 d->ld_obd->obd_lu_dev = NULL;
1222 lu_ref_fini(&d->ld_reference);
1223 LASSERTF(atomic_read(&d->ld_ref) == 0,
1224 "Refcount is %u\n", atomic_read(&d->ld_ref));
1225 LASSERT(atomic_read(&t->ldt_device_nr) > 0);
1227 if (atomic_dec_and_test(&t->ldt_device_nr) &&
1228 t->ldt_ops->ldto_stop != NULL)
1229 t->ldt_ops->ldto_stop(t);
1231 EXPORT_SYMBOL(lu_device_fini);
1234 * Initialize object \a o that is part of compound object \a h and was created
1237 int lu_object_init(struct lu_object *o, struct lu_object_header *h,
1238 struct lu_device *d)
1240 memset(o, 0, sizeof(*o));
1244 lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o);
1245 INIT_LIST_HEAD(&o->lo_linkage);
1249 EXPORT_SYMBOL(lu_object_init);
1252 * Finalize object and release its resources.
1254 void lu_object_fini(struct lu_object *o)
1256 struct lu_device *dev = o->lo_dev;
1258 LASSERT(list_empty(&o->lo_linkage));
1261 lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref,
1267 EXPORT_SYMBOL(lu_object_fini);
1270 * Add object \a o as first layer of compound object \a h
1272 * This is typically called by the ->ldo_object_alloc() method of top-level
1275 void lu_object_add_top(struct lu_object_header *h, struct lu_object *o)
1277 list_move(&o->lo_linkage, &h->loh_layers);
1279 EXPORT_SYMBOL(lu_object_add_top);
1282 * Add object \a o as a layer of compound object, going after \a before.
1284 * This is typically called by the ->ldo_object_alloc() method of \a
1287 void lu_object_add(struct lu_object *before, struct lu_object *o)
1289 list_move(&o->lo_linkage, &before->lo_linkage);
1291 EXPORT_SYMBOL(lu_object_add);
1294 * Initialize compound object.
1296 int lu_object_header_init(struct lu_object_header *h)
1298 memset(h, 0, sizeof *h);
1299 atomic_set(&h->loh_ref, 1);
1300 INIT_HLIST_NODE(&h->loh_hash);
1301 INIT_LIST_HEAD(&h->loh_lru);
1302 INIT_LIST_HEAD(&h->loh_layers);
1303 lu_ref_init(&h->loh_reference);
1306 EXPORT_SYMBOL(lu_object_header_init);
1309 * Finalize compound object.
1311 void lu_object_header_fini(struct lu_object_header *h)
1313 LASSERT(list_empty(&h->loh_layers));
1314 LASSERT(list_empty(&h->loh_lru));
1315 LASSERT(hlist_unhashed(&h->loh_hash));
1316 lu_ref_fini(&h->loh_reference);
1318 EXPORT_SYMBOL(lu_object_header_fini);
1321 * Given a compound object, find its slice, corresponding to the device type
1324 struct lu_object *lu_object_locate(struct lu_object_header *h,
1325 const struct lu_device_type *dtype)
1327 struct lu_object *o;
1329 list_for_each_entry(o, &h->loh_layers, lo_linkage) {
1330 if (o->lo_dev->ld_type == dtype)
1335 EXPORT_SYMBOL(lu_object_locate);
1338 * Finalize and free devices in the device stack.
1340 * Finalize device stack by purging object cache, and calling
1341 * lu_device_type_operations::ldto_device_fini() and
1342 * lu_device_type_operations::ldto_device_free() on all devices in the stack.
1344 void lu_stack_fini(const struct lu_env *env, struct lu_device *top)
1346 struct lu_site *site = top->ld_site;
1347 struct lu_device *scan;
1348 struct lu_device *next;
1350 lu_site_purge(env, site, ~0);
1351 for (scan = top; scan != NULL; scan = next) {
1352 next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan);
1353 lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init);
1354 lu_device_put(scan);
1358 lu_site_purge(env, site, ~0);
1360 for (scan = top; scan != NULL; scan = next) {
1361 const struct lu_device_type *ldt = scan->ld_type;
1362 struct obd_type *type;
1364 next = ldt->ldt_ops->ldto_device_free(env, scan);
1365 type = ldt->ldt_obd_type;
1368 class_put_type(type);
1375 * Maximal number of tld slots.
1377 LU_CONTEXT_KEY_NR = 40
1380 static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, };
1382 DEFINE_RWLOCK(lu_keys_guard);
1383 static atomic_t lu_key_initing_cnt = ATOMIC_INIT(0);
1386 * Global counter incremented whenever key is registered, unregistered,
1387 * revived or quiesced. This is used to void unnecessary calls to
1388 * lu_context_refill(). No locking is provided, as initialization and shutdown
1389 * are supposed to be externally serialized.
1391 static unsigned key_set_version = 0;
1396 int lu_context_key_register(struct lu_context_key *key)
1401 LASSERT(key->lct_init != NULL);
1402 LASSERT(key->lct_fini != NULL);
1403 LASSERT(key->lct_tags != 0);
1404 LASSERT(key->lct_owner != NULL);
1407 write_lock(&lu_keys_guard);
1408 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1409 if (lu_keys[i] == NULL) {
1411 atomic_set(&key->lct_used, 1);
1413 lu_ref_init(&key->lct_reference);
1419 write_unlock(&lu_keys_guard);
1422 EXPORT_SYMBOL(lu_context_key_register);
1424 static void key_fini(struct lu_context *ctx, int index)
1426 if (ctx->lc_value != NULL && ctx->lc_value[index] != NULL) {
1427 struct lu_context_key *key;
1429 key = lu_keys[index];
1430 LASSERT(key != NULL);
1431 LASSERT(key->lct_fini != NULL);
1432 LASSERT(atomic_read(&key->lct_used) > 1);
1434 key->lct_fini(ctx, key, ctx->lc_value[index]);
1435 lu_ref_del(&key->lct_reference, "ctx", ctx);
1436 atomic_dec(&key->lct_used);
1438 LASSERT(key->lct_owner != NULL);
1439 if ((ctx->lc_tags & LCT_NOREF) == 0) {
1440 LINVRNT(module_refcount(key->lct_owner) > 0);
1441 module_put(key->lct_owner);
1443 ctx->lc_value[index] = NULL;
1450 void lu_context_key_degister(struct lu_context_key *key)
1452 LASSERT(atomic_read(&key->lct_used) >= 1);
1453 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1455 lu_context_key_quiesce(key);
1458 write_lock(&lu_keys_guard);
1459 key_fini(&lu_shrink_env.le_ctx, key->lct_index);
1462 * Wait until all transient contexts referencing this key have
1463 * run lu_context_key::lct_fini() method.
1465 while (atomic_read(&key->lct_used) > 1) {
1466 write_unlock(&lu_keys_guard);
1467 CDEBUG(D_INFO, "lu_context_key_degister: \"%s\" %p, %d\n",
1468 key->lct_owner ? key->lct_owner->name : "", key,
1469 atomic_read(&key->lct_used));
1471 write_lock(&lu_keys_guard);
1473 if (lu_keys[key->lct_index]) {
1474 lu_keys[key->lct_index] = NULL;
1475 lu_ref_fini(&key->lct_reference);
1477 write_unlock(&lu_keys_guard);
1479 LASSERTF(atomic_read(&key->lct_used) == 1,
1480 "key has instances: %d\n",
1481 atomic_read(&key->lct_used));
1483 EXPORT_SYMBOL(lu_context_key_degister);
1486 * Register a number of keys. This has to be called after all keys have been
1487 * initialized by a call to LU_CONTEXT_KEY_INIT().
1489 int lu_context_key_register_many(struct lu_context_key *k, ...)
1491 struct lu_context_key *key = k;
1497 result = lu_context_key_register(key);
1500 key = va_arg(args, struct lu_context_key *);
1501 } while (key != NULL);
1507 lu_context_key_degister(k);
1508 k = va_arg(args, struct lu_context_key *);
1515 EXPORT_SYMBOL(lu_context_key_register_many);
1518 * De-register a number of keys. This is a dual to
1519 * lu_context_key_register_many().
1521 void lu_context_key_degister_many(struct lu_context_key *k, ...)
1527 lu_context_key_degister(k);
1528 k = va_arg(args, struct lu_context_key*);
1529 } while (k != NULL);
1532 EXPORT_SYMBOL(lu_context_key_degister_many);
1535 * Revive a number of keys.
1537 void lu_context_key_revive_many(struct lu_context_key *k, ...)
1543 lu_context_key_revive(k);
1544 k = va_arg(args, struct lu_context_key*);
1545 } while (k != NULL);
1548 EXPORT_SYMBOL(lu_context_key_revive_many);
1551 * Quiescent a number of keys.
1553 void lu_context_key_quiesce_many(struct lu_context_key *k, ...)
1559 lu_context_key_quiesce(k);
1560 k = va_arg(args, struct lu_context_key*);
1561 } while (k != NULL);
1564 EXPORT_SYMBOL(lu_context_key_quiesce_many);
1567 * Return value associated with key \a key in context \a ctx.
1569 void *lu_context_key_get(const struct lu_context *ctx,
1570 const struct lu_context_key *key)
1572 LINVRNT(ctx->lc_state == LCS_ENTERED);
1573 LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys));
1574 LASSERT(lu_keys[key->lct_index] == key);
1575 return ctx->lc_value[key->lct_index];
1577 EXPORT_SYMBOL(lu_context_key_get);
1580 * List of remembered contexts. XXX document me.
1582 static struct list_head lu_context_remembered;
1585 * Destroy \a key in all remembered contexts. This is used to destroy key
1586 * values in "shared" contexts (like service threads), when a module owning
1587 * the key is about to be unloaded.
1589 void lu_context_key_quiesce(struct lu_context_key *key)
1591 struct lu_context *ctx;
1592 extern unsigned cl_env_cache_purge(unsigned nr);
1594 if (!(key->lct_tags & LCT_QUIESCENT)) {
1596 * XXX layering violation.
1598 cl_env_cache_purge(~0);
1600 * XXX memory barrier has to go here.
1602 write_lock(&lu_keys_guard);
1603 key->lct_tags |= LCT_QUIESCENT;
1606 * Wait until all lu_context_key::lct_init() methods
1609 while (atomic_read(&lu_key_initing_cnt) > 0) {
1610 write_unlock(&lu_keys_guard);
1611 CDEBUG(D_INFO, "lu_context_key_quiesce: \"%s\""
1613 key->lct_owner ? key->lct_owner->name : "",
1614 key, atomic_read(&key->lct_used),
1615 atomic_read(&lu_key_initing_cnt));
1617 write_lock(&lu_keys_guard);
1620 list_for_each_entry(ctx, &lu_context_remembered,
1622 key_fini(ctx, key->lct_index);
1623 write_unlock(&lu_keys_guard);
1628 void lu_context_key_revive(struct lu_context_key *key)
1630 key->lct_tags &= ~LCT_QUIESCENT;
1634 static void keys_fini(struct lu_context *ctx)
1638 if (ctx->lc_value == NULL)
1641 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i)
1644 OBD_FREE(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1645 ctx->lc_value = NULL;
1648 static int keys_fill(struct lu_context *ctx)
1653 * A serialisation with lu_context_key_quiesce() is needed, but some
1654 * "key->lct_init()" are calling kernel memory allocation routine and
1655 * can't be called while holding a spin_lock.
1656 * "lu_keys_guard" is held while incrementing "lu_key_initing_cnt"
1657 * to ensure the start of the serialisation.
1658 * An atomic_t variable is still used, in order not to reacquire the
1659 * lock when decrementing the counter.
1661 read_lock(&lu_keys_guard);
1662 atomic_inc(&lu_key_initing_cnt);
1663 read_unlock(&lu_keys_guard);
1665 LINVRNT(ctx->lc_value != NULL);
1666 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1667 struct lu_context_key *key;
1670 if (ctx->lc_value[i] == NULL && key != NULL &&
1671 (key->lct_tags & ctx->lc_tags) &&
1673 * Don't create values for a LCT_QUIESCENT key, as this
1674 * will pin module owning a key.
1676 !(key->lct_tags & LCT_QUIESCENT)) {
1679 LINVRNT(key->lct_init != NULL);
1680 LINVRNT(key->lct_index == i);
1682 LASSERT(key->lct_owner != NULL);
1683 if (!(ctx->lc_tags & LCT_NOREF) &&
1684 try_module_get(key->lct_owner) == 0) {
1685 /* module is unloading, skip this key */
1689 value = key->lct_init(ctx, key);
1690 if (unlikely(IS_ERR(value))) {
1691 atomic_dec(&lu_key_initing_cnt);
1692 return PTR_ERR(value);
1695 lu_ref_add_atomic(&key->lct_reference, "ctx", ctx);
1696 atomic_inc(&key->lct_used);
1698 * This is the only place in the code, where an
1699 * element of ctx->lc_value[] array is set to non-NULL
1702 ctx->lc_value[i] = value;
1703 if (key->lct_exit != NULL)
1704 ctx->lc_tags |= LCT_HAS_EXIT;
1706 ctx->lc_version = key_set_version;
1708 atomic_dec(&lu_key_initing_cnt);
1712 static int keys_init(struct lu_context *ctx)
1714 OBD_ALLOC(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof ctx->lc_value[0]);
1715 if (likely(ctx->lc_value != NULL))
1716 return keys_fill(ctx);
1722 * Initialize context data-structure. Create values for all keys.
1724 int lu_context_init(struct lu_context *ctx, __u32 tags)
1728 memset(ctx, 0, sizeof *ctx);
1729 ctx->lc_state = LCS_INITIALIZED;
1730 ctx->lc_tags = tags;
1731 if (tags & LCT_REMEMBER) {
1732 write_lock(&lu_keys_guard);
1733 list_add(&ctx->lc_remember, &lu_context_remembered);
1734 write_unlock(&lu_keys_guard);
1736 INIT_LIST_HEAD(&ctx->lc_remember);
1739 rc = keys_init(ctx);
1741 lu_context_fini(ctx);
1745 EXPORT_SYMBOL(lu_context_init);
1748 * Finalize context data-structure. Destroy key values.
1750 void lu_context_fini(struct lu_context *ctx)
1752 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1753 ctx->lc_state = LCS_FINALIZED;
1755 if ((ctx->lc_tags & LCT_REMEMBER) == 0) {
1756 LASSERT(list_empty(&ctx->lc_remember));
1759 } else { /* could race with key degister */
1760 write_lock(&lu_keys_guard);
1762 list_del_init(&ctx->lc_remember);
1763 write_unlock(&lu_keys_guard);
1766 EXPORT_SYMBOL(lu_context_fini);
1769 * Called before entering context.
1771 void lu_context_enter(struct lu_context *ctx)
1773 LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT);
1774 ctx->lc_state = LCS_ENTERED;
1776 EXPORT_SYMBOL(lu_context_enter);
1779 * Called after exiting from \a ctx
1781 void lu_context_exit(struct lu_context *ctx)
1785 LINVRNT(ctx->lc_state == LCS_ENTERED);
1786 ctx->lc_state = LCS_LEFT;
1787 if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) {
1788 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
1789 /* could race with key quiescency */
1790 if (ctx->lc_tags & LCT_REMEMBER)
1791 read_lock(&lu_keys_guard);
1792 if (ctx->lc_value[i] != NULL) {
1793 struct lu_context_key *key;
1796 LASSERT(key != NULL);
1797 if (key->lct_exit != NULL)
1799 key, ctx->lc_value[i]);
1801 if (ctx->lc_tags & LCT_REMEMBER)
1802 read_unlock(&lu_keys_guard);
1806 EXPORT_SYMBOL(lu_context_exit);
1809 * Allocate for context all missing keys that were registered after context
1810 * creation. key_set_version is only changed in rare cases when modules
1811 * are loaded and removed.
1813 int lu_context_refill(struct lu_context *ctx)
1815 return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx);
1819 * lu_ctx_tags/lu_ses_tags will be updated if there are new types of
1820 * obd being added. Currently, this is only used on client side, specifically
1821 * for echo device client, for other stack (like ptlrpc threads), context are
1822 * predefined when the lu_device type are registered, during the module probe
1825 __u32 lu_context_tags_default = 0;
1826 __u32 lu_session_tags_default = 0;
1828 void lu_context_tags_update(__u32 tags)
1830 write_lock(&lu_keys_guard);
1831 lu_context_tags_default |= tags;
1833 write_unlock(&lu_keys_guard);
1835 EXPORT_SYMBOL(lu_context_tags_update);
1837 void lu_context_tags_clear(__u32 tags)
1839 write_lock(&lu_keys_guard);
1840 lu_context_tags_default &= ~tags;
1842 write_unlock(&lu_keys_guard);
1844 EXPORT_SYMBOL(lu_context_tags_clear);
1846 void lu_session_tags_update(__u32 tags)
1848 write_lock(&lu_keys_guard);
1849 lu_session_tags_default |= tags;
1851 write_unlock(&lu_keys_guard);
1853 EXPORT_SYMBOL(lu_session_tags_update);
1855 void lu_session_tags_clear(__u32 tags)
1857 write_lock(&lu_keys_guard);
1858 lu_session_tags_default &= ~tags;
1860 write_unlock(&lu_keys_guard);
1862 EXPORT_SYMBOL(lu_session_tags_clear);
1864 int lu_env_init(struct lu_env *env, __u32 tags)
1869 result = lu_context_init(&env->le_ctx, tags);
1870 if (likely(result == 0))
1871 lu_context_enter(&env->le_ctx);
1874 EXPORT_SYMBOL(lu_env_init);
1876 void lu_env_fini(struct lu_env *env)
1878 lu_context_exit(&env->le_ctx);
1879 lu_context_fini(&env->le_ctx);
1882 EXPORT_SYMBOL(lu_env_fini);
1884 int lu_env_refill(struct lu_env *env)
1888 result = lu_context_refill(&env->le_ctx);
1889 if (result == 0 && env->le_ses != NULL)
1890 result = lu_context_refill(env->le_ses);
1893 EXPORT_SYMBOL(lu_env_refill);
1896 * Currently, this API will only be used by echo client.
1897 * Because echo client and normal lustre client will share
1898 * same cl_env cache. So echo client needs to refresh
1899 * the env context after it get one from the cache, especially
1900 * when normal client and echo client co-exist in the same client.
1902 int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags,
1907 if ((env->le_ctx.lc_tags & ctags) != ctags) {
1908 env->le_ctx.lc_version = 0;
1909 env->le_ctx.lc_tags |= ctags;
1912 if (env->le_ses && (env->le_ses->lc_tags & stags) != stags) {
1913 env->le_ses->lc_version = 0;
1914 env->le_ses->lc_tags |= stags;
1917 result = lu_env_refill(env);
1921 EXPORT_SYMBOL(lu_env_refill_by_tags);
1923 static struct shrinker *lu_site_shrinker;
1925 typedef struct lu_site_stats{
1926 unsigned lss_populated;
1927 unsigned lss_max_search;
1932 static void lu_site_stats_get(struct cfs_hash *hs,
1933 lu_site_stats_t *stats, int populated)
1935 struct cfs_hash_bd bd;
1938 cfs_hash_for_each_bucket(hs, &bd, i) {
1939 struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd);
1940 struct hlist_head *hhead;
1942 cfs_hash_bd_lock(hs, &bd, 1);
1944 cfs_hash_bd_count_get(&bd) - bkt->lsb_lru_len;
1945 stats->lss_total += cfs_hash_bd_count_get(&bd);
1946 stats->lss_max_search = max((int)stats->lss_max_search,
1947 cfs_hash_bd_depmax_get(&bd));
1949 cfs_hash_bd_unlock(hs, &bd, 1);
1953 cfs_hash_bd_for_each_hlist(hs, &bd, hhead) {
1954 if (!hlist_empty(hhead))
1955 stats->lss_populated++;
1957 cfs_hash_bd_unlock(hs, &bd, 1);
1963 * lu_cache_shrink_count returns the number of cached objects that are
1964 * candidates to be freed by shrink_slab(). A counter, which tracks
1965 * the number of items in the site's lru, is maintained in the per cpu
1966 * stats of each site. The counter is incremented when an object is added
1967 * to a site's lru and decremented when one is removed. The number of
1968 * free-able objects is the sum of all per cpu counters for all sites.
1970 * Using a per cpu counter is a compromise solution to concurrent access:
1971 * lu_object_put() can update the counter without locking the site and
1972 * lu_cache_shrink_count can sum the counters without locking each
1973 * ls_obj_hash bucket.
1975 static unsigned long lu_cache_shrink_count(struct shrinker *sk,
1976 struct shrink_control *sc)
1979 struct lu_site *tmp;
1980 unsigned long cached = 0;
1982 if (!(sc->gfp_mask & __GFP_FS))
1985 mutex_lock(&lu_sites_guard);
1986 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
1987 cached += ls_stats_read(s->ls_stats, LU_SS_LRU_LEN);
1989 mutex_unlock(&lu_sites_guard);
1991 cached = (cached / 100) * sysctl_vfs_cache_pressure;
1992 CDEBUG(D_INODE, "%ld objects cached, cache pressure %d\n",
1993 cached, sysctl_vfs_cache_pressure);
1998 static unsigned long lu_cache_shrink_scan(struct shrinker *sk,
1999 struct shrink_control *sc)
2002 struct lu_site *tmp;
2003 unsigned long remain = sc->nr_to_scan;
2006 if (!(sc->gfp_mask & __GFP_FS))
2007 /* We must not take the lu_sites_guard lock when
2008 * __GFP_FS is *not* set because of the deadlock
2009 * possibility detailed above. Additionally,
2010 * since we cannot determine the number of
2011 * objects in the cache without taking this
2012 * lock, we're in a particularly tough spot. As
2013 * a result, we'll just lie and say our cache is
2014 * empty. This _should_ be ok, as we can't
2015 * reclaim objects when __GFP_FS is *not* set
2020 mutex_lock(&lu_sites_guard);
2021 list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) {
2022 remain = lu_site_purge(&lu_shrink_env, s, remain);
2024 * Move just shrunk site to the tail of site list to
2025 * assure shrinking fairness.
2027 list_move_tail(&s->ls_linkage, &splice);
2029 list_splice(&splice, lu_sites.prev);
2030 mutex_unlock(&lu_sites_guard);
2032 return sc->nr_to_scan - remain;
2035 #ifndef HAVE_SHRINKER_COUNT
2037 * There exists a potential lock inversion deadlock scenario when using
2038 * Lustre on top of ZFS. This occurs between one of ZFS's
2039 * buf_hash_table.ht_lock's, and Lustre's lu_sites_guard lock. Essentially,
2040 * thread A will take the lu_sites_guard lock and sleep on the ht_lock,
2041 * while thread B will take the ht_lock and sleep on the lu_sites_guard
2042 * lock. Obviously neither thread will wake and drop their respective hold
2045 * To prevent this from happening we must ensure the lu_sites_guard lock is
2046 * not taken while down this code path. ZFS reliably does not set the
2047 * __GFP_FS bit in its code paths, so this can be used to determine if it
2048 * is safe to take the lu_sites_guard lock.
2050 * Ideally we should accurately return the remaining number of cached
2051 * objects without taking the lu_sites_guard lock, but this is not
2052 * possible in the current implementation.
2054 static int lu_cache_shrink(SHRINKER_ARGS(sc, nr_to_scan, gfp_mask))
2057 struct shrink_control scv = {
2058 .nr_to_scan = shrink_param(sc, nr_to_scan),
2059 .gfp_mask = shrink_param(sc, gfp_mask)
2061 #if !defined(HAVE_SHRINKER_WANT_SHRINK_PTR) && !defined(HAVE_SHRINK_CONTROL)
2062 struct shrinker* shrinker = NULL;
2066 CDEBUG(D_INODE, "Shrink %lu objects\n", scv.nr_to_scan);
2068 if (scv.nr_to_scan != 0)
2069 lu_cache_shrink_scan(shrinker, &scv);
2071 cached = lu_cache_shrink_count(shrinker, &scv);
2075 #endif /* HAVE_SHRINKER_COUNT */
2083 * Environment to be used in debugger, contains all tags.
2085 static struct lu_env lu_debugging_env;
2088 * Debugging printer function using printk().
2090 int lu_printk_printer(const struct lu_env *env,
2091 void *unused, const char *format, ...)
2095 va_start(args, format);
2096 vprintk(format, args);
2101 int lu_debugging_setup(void)
2103 return lu_env_init(&lu_debugging_env, ~0);
2106 void lu_context_keys_dump(void)
2110 for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) {
2111 struct lu_context_key *key;
2115 CERROR("[%d]: %p %x (%p,%p,%p) %d %d \"%s\"@%p\n",
2116 i, key, key->lct_tags,
2117 key->lct_init, key->lct_fini, key->lct_exit,
2118 key->lct_index, atomic_read(&key->lct_used),
2119 key->lct_owner ? key->lct_owner->name : "",
2121 lu_ref_print(&key->lct_reference);
2127 * Initialization of global lu_* data.
2129 int lu_global_init(void)
2132 DEF_SHRINKER_VAR(shvar, lu_cache_shrink,
2133 lu_cache_shrink_count, lu_cache_shrink_scan);
2135 CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys);
2137 INIT_LIST_HEAD(&lu_device_types);
2138 INIT_LIST_HEAD(&lu_context_remembered);
2139 INIT_LIST_HEAD(&lu_sites);
2141 result = lu_ref_global_init();
2145 LU_CONTEXT_KEY_INIT(&lu_global_key);
2146 result = lu_context_key_register(&lu_global_key);
2151 * At this level, we don't know what tags are needed, so allocate them
2152 * conservatively. This should not be too bad, because this
2153 * environment is global.
2155 mutex_lock(&lu_sites_guard);
2156 result = lu_env_init(&lu_shrink_env, LCT_SHRINKER);
2157 mutex_unlock(&lu_sites_guard);
2162 * seeks estimation: 3 seeks to read a record from oi, one to read
2163 * inode, one for ea. Unfortunately setting this high value results in
2164 * lu_object/inode cache consuming all the memory.
2166 lu_site_shrinker = set_shrinker(DEFAULT_SEEKS, &shvar);
2167 if (lu_site_shrinker == NULL)
2174 * Dual to lu_global_init().
2176 void lu_global_fini(void)
2178 if (lu_site_shrinker != NULL) {
2179 remove_shrinker(lu_site_shrinker);
2180 lu_site_shrinker = NULL;
2183 lu_context_key_degister(&lu_global_key);
2186 * Tear shrinker environment down _after_ de-registering
2187 * lu_global_key, because the latter has a value in the former.
2189 mutex_lock(&lu_sites_guard);
2190 lu_env_fini(&lu_shrink_env);
2191 mutex_unlock(&lu_sites_guard);
2193 lu_ref_global_fini();
2196 static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx)
2198 #ifdef CONFIG_PROC_FS
2199 struct lprocfs_counter ret;
2201 lprocfs_stats_collect(stats, idx, &ret);
2202 if (idx == LU_SS_LRU_LEN)
2204 * protect against counter on cpu A being decremented
2205 * before counter is incremented on cpu B; unlikely
2207 return (__u32)((ret.lc_sum > 0) ? ret.lc_sum : 0);
2209 return (__u32)ret.lc_count;
2216 * Output site statistical counters into a buffer. Suitable for
2217 * lprocfs_rd_*()-style functions.
2219 int lu_site_stats_seq_print(const struct lu_site *s, struct seq_file *m)
2221 lu_site_stats_t stats;
2223 memset(&stats, 0, sizeof(stats));
2224 lu_site_stats_get(s->ls_obj_hash, &stats, 1);
2226 return seq_printf(m, "%d/%d %d/%d %d %d %d %d %d %d %d %d\n",
2229 stats.lss_populated,
2230 CFS_HASH_NHLIST(s->ls_obj_hash),
2231 stats.lss_max_search,
2232 ls_stats_read(s->ls_stats, LU_SS_CREATED),
2233 ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
2234 ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
2235 ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
2236 ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
2237 ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED),
2238 ls_stats_read(s->ls_stats, LU_SS_LRU_LEN));
2240 EXPORT_SYMBOL(lu_site_stats_seq_print);
2242 int lu_site_stats_print(const struct lu_site *s, char *page, int count)
2244 lu_site_stats_t stats;
2246 memset(&stats, 0, sizeof(stats));
2247 lu_site_stats_get(s->ls_obj_hash, &stats, 1);
2249 return snprintf(page, count, "%d/%d %d/%d %d %d %d %d %d %d %d %d\n",
2252 stats.lss_populated,
2253 CFS_HASH_NHLIST(s->ls_obj_hash),
2254 stats.lss_max_search,
2255 ls_stats_read(s->ls_stats, LU_SS_CREATED),
2256 ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT),
2257 ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS),
2258 ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE),
2259 ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE),
2260 ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED),
2261 ls_stats_read(s->ls_stats, LU_SS_LRU_LEN));
2265 * Helper function to initialize a number of kmem slab caches at once.
2267 int lu_kmem_init(struct lu_kmem_descr *caches)
2270 struct lu_kmem_descr *iter = caches;
2272 for (result = 0; iter->ckd_cache != NULL; ++iter) {
2273 *iter->ckd_cache = kmem_cache_create(iter->ckd_name,
2276 if (*iter->ckd_cache == NULL) {
2278 /* free all previously allocated caches */
2279 lu_kmem_fini(caches);
2285 EXPORT_SYMBOL(lu_kmem_init);
2288 * Helper function to finalize a number of kmem slab cached at once. Dual to
2291 void lu_kmem_fini(struct lu_kmem_descr *caches)
2293 for (; caches->ckd_cache != NULL; ++caches) {
2294 if (*caches->ckd_cache != NULL) {
2295 kmem_cache_destroy(*caches->ckd_cache);
2296 *caches->ckd_cache = NULL;
2300 EXPORT_SYMBOL(lu_kmem_fini);
2303 * Temporary solution to be able to assign fid in ->do_create()
2304 * till we have fully-functional OST fids
2306 void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o,
2307 const struct lu_fid *fid)
2309 struct lu_site *s = o->lo_dev->ld_site;
2310 struct lu_fid *old = &o->lo_header->loh_fid;
2311 struct lu_object *shadow;
2312 wait_queue_t waiter;
2313 struct cfs_hash *hs;
2314 struct cfs_hash_bd bd;
2317 LASSERT(fid_is_zero(old));
2319 hs = s->ls_obj_hash;
2320 cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1);
2321 shadow = htable_lookup(s, &bd, fid, &waiter, &version);
2322 /* supposed to be unique */
2323 LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT);
2325 cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash);
2326 cfs_hash_bd_unlock(hs, &bd, 1);
2328 EXPORT_SYMBOL(lu_object_assign_fid);
2331 * allocates object with 0 (non-assiged) fid
2332 * XXX: temporary solution to be able to assign fid in ->do_create()
2333 * till we have fully-functional OST fids
2335 struct lu_object *lu_object_anon(const struct lu_env *env,
2336 struct lu_device *dev,
2337 const struct lu_object_conf *conf)
2340 struct lu_object *o;
2343 o = lu_object_alloc(env, dev, &fid, conf);
2347 EXPORT_SYMBOL(lu_object_anon);
2349 struct lu_buf LU_BUF_NULL = {
2353 EXPORT_SYMBOL(LU_BUF_NULL);
2355 void lu_buf_free(struct lu_buf *buf)
2359 LASSERT(buf->lb_len > 0);
2360 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);
2365 EXPORT_SYMBOL(lu_buf_free);
2367 void lu_buf_alloc(struct lu_buf *buf, size_t size)
2370 LASSERT(buf->lb_buf == NULL);
2371 LASSERT(buf->lb_len == 0);
2372 OBD_ALLOC_LARGE(buf->lb_buf, size);
2373 if (likely(buf->lb_buf))
2376 EXPORT_SYMBOL(lu_buf_alloc);
2378 void lu_buf_realloc(struct lu_buf *buf, size_t size)
2381 lu_buf_alloc(buf, size);
2383 EXPORT_SYMBOL(lu_buf_realloc);
2385 struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, size_t len)
2387 if (buf->lb_buf == NULL && buf->lb_len == 0)
2388 lu_buf_alloc(buf, len);
2390 if ((len > buf->lb_len) && (buf->lb_buf != NULL))
2391 lu_buf_realloc(buf, len);
2395 EXPORT_SYMBOL(lu_buf_check_and_alloc);
2398 * Increase the size of the \a buf.
2399 * preserves old data in buffer
2400 * old buffer remains unchanged on error
2401 * \retval 0 or -ENOMEM
2403 int lu_buf_check_and_grow(struct lu_buf *buf, size_t len)
2407 if (len <= buf->lb_len)
2410 OBD_ALLOC_LARGE(ptr, len);
2414 /* Free the old buf */
2415 if (buf->lb_buf != NULL) {
2416 memcpy(ptr, buf->lb_buf, buf->lb_len);
2417 OBD_FREE_LARGE(buf->lb_buf, buf->lb_len);