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 "../../include/linux/libcfs/libcfs.h"
49 # include <linux/module.h>
52 #include "../../include/linux/libcfs/libcfs_hash.h"
53 #include "../include/obd_class.h"
54 #include "../include/obd_support.h"
55 #include "../include/lustre_disk.h"
56 #include "../include/lustre_fid.h"
57 #include "../include/lu_object.h"
58 #include "../include/lu_ref.h"
59 #include <linux/list.h>
61 static void lu_object_free(const struct lu_env
*env
, struct lu_object
*o
);
62 static __u32
ls_stats_read(struct lprocfs_stats
*stats
, int idx
);
65 * Decrease reference counter on object. If last reference is freed, return
66 * object to the cache, unless lu_object_is_dying(o) holds. In the latter
67 * case, free object immediately.
69 void lu_object_put(const struct lu_env
*env
, struct lu_object
*o
)
71 struct lu_site_bkt_data
*bkt
;
72 struct lu_object_header
*top
;
74 struct lu_object
*orig
;
75 struct cfs_hash_bd bd
;
76 const struct lu_fid
*fid
;
79 site
= o
->lo_dev
->ld_site
;
83 * till we have full fids-on-OST implemented anonymous objects
84 * are possible in OSP. such an object isn't listed in the site
85 * so we should not remove it from the site.
87 fid
= lu_object_fid(o
);
88 if (fid_is_zero(fid
)) {
89 LASSERT(top
->loh_hash
.next
== NULL
90 && top
->loh_hash
.pprev
== NULL
);
91 LASSERT(list_empty(&top
->loh_lru
));
92 if (!atomic_dec_and_test(&top
->loh_ref
))
94 list_for_each_entry_reverse(o
, &top
->loh_layers
, lo_linkage
) {
95 if (o
->lo_ops
->loo_object_release
!= NULL
)
96 o
->lo_ops
->loo_object_release(env
, o
);
98 lu_object_free(env
, orig
);
102 cfs_hash_bd_get(site
->ls_obj_hash
, &top
->loh_fid
, &bd
);
103 bkt
= cfs_hash_bd_extra_get(site
->ls_obj_hash
, &bd
);
105 if (!cfs_hash_bd_dec_and_lock(site
->ls_obj_hash
, &bd
, &top
->loh_ref
)) {
106 if (lu_object_is_dying(top
)) {
109 * somebody may be waiting for this, currently only
110 * used for cl_object, see cl_object_put_last().
112 wake_up_all(&bkt
->lsb_marche_funebre
);
118 * When last reference is released, iterate over object
119 * layers, and notify them that object is no longer busy.
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
);
126 if (!lu_object_is_dying(top
)) {
127 LASSERT(list_empty(&top
->loh_lru
));
128 list_add_tail(&top
->loh_lru
, &bkt
->lsb_lru
);
130 lprocfs_counter_incr(site
->ls_stats
, LU_SS_LRU_LEN
);
131 CDEBUG(D_INODE
, "Add %p to site lru. hash: %p, bkt: %p, lru_len: %ld\n",
132 o
, site
->ls_obj_hash
, bkt
, bkt
->lsb_lru_len
);
133 cfs_hash_bd_unlock(site
->ls_obj_hash
, &bd
, 1);
138 * If object is dying (will not be cached), removed it
139 * from hash table and LRU.
141 * This is done with hash table and LRU lists locked. As the only
142 * way to acquire first reference to previously unreferenced
143 * object is through hash-table lookup (lu_object_find()),
144 * or LRU scanning (lu_site_purge()), that are done under hash-table
145 * and LRU lock, no race with concurrent object lookup is possible
146 * and we can safely destroy object below.
148 if (!test_and_set_bit(LU_OBJECT_UNHASHED
, &top
->loh_flags
))
149 cfs_hash_bd_del_locked(site
->ls_obj_hash
, &bd
, &top
->loh_hash
);
150 cfs_hash_bd_unlock(site
->ls_obj_hash
, &bd
, 1);
152 * Object was already removed from hash and lru above, can
155 lu_object_free(env
, orig
);
157 EXPORT_SYMBOL(lu_object_put
);
160 * Kill the object and take it out of LRU cache.
161 * Currently used by client code for layout change.
163 void lu_object_unhash(const struct lu_env
*env
, struct lu_object
*o
)
165 struct lu_object_header
*top
;
168 set_bit(LU_OBJECT_HEARD_BANSHEE
, &top
->loh_flags
);
169 if (!test_and_set_bit(LU_OBJECT_UNHASHED
, &top
->loh_flags
)) {
170 struct lu_site
*site
= o
->lo_dev
->ld_site
;
171 struct cfs_hash
*obj_hash
= site
->ls_obj_hash
;
172 struct cfs_hash_bd bd
;
174 cfs_hash_bd_get_and_lock(obj_hash
, &top
->loh_fid
, &bd
, 1);
175 if (!list_empty(&top
->loh_lru
)) {
176 struct lu_site_bkt_data
*bkt
;
178 list_del_init(&top
->loh_lru
);
179 bkt
= cfs_hash_bd_extra_get(obj_hash
, &bd
);
181 lprocfs_counter_decr(site
->ls_stats
, LU_SS_LRU_LEN
);
183 cfs_hash_bd_del_locked(obj_hash
, &bd
, &top
->loh_hash
);
184 cfs_hash_bd_unlock(obj_hash
, &bd
, 1);
187 EXPORT_SYMBOL(lu_object_unhash
);
190 * Allocate new object.
192 * This follows object creation protocol, described in the comment within
193 * struct lu_device_operations definition.
195 static struct lu_object
*lu_object_alloc(const struct lu_env
*env
,
196 struct lu_device
*dev
,
197 const struct lu_fid
*f
,
198 const struct lu_object_conf
*conf
)
200 struct lu_object
*scan
;
201 struct lu_object
*top
;
202 struct list_head
*layers
;
203 unsigned int init_mask
= 0;
204 unsigned int init_flag
;
209 * Create top-level object slice. This will also create
212 top
= dev
->ld_ops
->ldo_object_alloc(env
, NULL
, dev
);
214 return ERR_PTR(-ENOMEM
);
218 * This is the only place where object fid is assigned. It's constant
221 top
->lo_header
->loh_fid
= *f
;
222 layers
= &top
->lo_header
->loh_layers
;
226 * Call ->loo_object_init() repeatedly, until no more new
227 * object slices are created.
231 list_for_each_entry(scan
, layers
, lo_linkage
) {
232 if (init_mask
& init_flag
)
235 scan
->lo_header
= top
->lo_header
;
236 result
= scan
->lo_ops
->loo_object_init(env
, scan
, conf
);
238 lu_object_free(env
, top
);
239 return ERR_PTR(result
);
241 init_mask
|= init_flag
;
247 list_for_each_entry_reverse(scan
, layers
, lo_linkage
) {
248 if (scan
->lo_ops
->loo_object_start
!= NULL
) {
249 result
= scan
->lo_ops
->loo_object_start(env
, scan
);
251 lu_object_free(env
, top
);
252 return ERR_PTR(result
);
257 lprocfs_counter_incr(dev
->ld_site
->ls_stats
, LU_SS_CREATED
);
264 static void lu_object_free(const struct lu_env
*env
, struct lu_object
*o
)
266 struct lu_site_bkt_data
*bkt
;
267 struct lu_site
*site
;
268 struct lu_object
*scan
;
269 struct list_head
*layers
;
270 struct list_head splice
;
272 site
= o
->lo_dev
->ld_site
;
273 layers
= &o
->lo_header
->loh_layers
;
274 bkt
= lu_site_bkt_from_fid(site
, &o
->lo_header
->loh_fid
);
276 * First call ->loo_object_delete() method to release all resources.
278 list_for_each_entry_reverse(scan
, layers
, lo_linkage
) {
279 if (scan
->lo_ops
->loo_object_delete
!= NULL
)
280 scan
->lo_ops
->loo_object_delete(env
, scan
);
284 * Then, splice object layers into stand-alone list, and call
285 * ->loo_object_free() on all layers to free memory. Splice is
286 * necessary, because lu_object_header is freed together with the
289 INIT_LIST_HEAD(&splice
);
290 list_splice_init(layers
, &splice
);
291 while (!list_empty(&splice
)) {
293 * Free layers in bottom-to-top order, so that object header
294 * lives as long as possible and ->loo_object_free() methods
295 * can look at its contents.
297 o
= container_of0(splice
.prev
, struct lu_object
, lo_linkage
);
298 list_del_init(&o
->lo_linkage
);
299 LASSERT(o
->lo_ops
->loo_object_free
!= NULL
);
300 o
->lo_ops
->loo_object_free(env
, o
);
303 if (waitqueue_active(&bkt
->lsb_marche_funebre
))
304 wake_up_all(&bkt
->lsb_marche_funebre
);
308 * Free \a nr objects from the cold end of the site LRU list.
310 int lu_site_purge(const struct lu_env
*env
, struct lu_site
*s
, int nr
)
312 struct lu_object_header
*h
;
313 struct lu_object_header
*temp
;
314 struct lu_site_bkt_data
*bkt
;
315 struct cfs_hash_bd bd
;
316 struct cfs_hash_bd bd2
;
317 struct list_head dispose
;
324 if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU
))
327 INIT_LIST_HEAD(&dispose
);
329 * Under LRU list lock, scan LRU list and move unreferenced objects to
330 * the dispose list, removing them from LRU and hash table.
332 start
= s
->ls_purge_start
;
333 bnr
= (nr
== ~0) ? -1 : nr
/ CFS_HASH_NBKT(s
->ls_obj_hash
) + 1;
336 cfs_hash_for_each_bucket(s
->ls_obj_hash
, &bd
, i
) {
340 cfs_hash_bd_lock(s
->ls_obj_hash
, &bd
, 1);
341 bkt
= cfs_hash_bd_extra_get(s
->ls_obj_hash
, &bd
);
343 list_for_each_entry_safe(h
, temp
, &bkt
->lsb_lru
, loh_lru
) {
344 LASSERT(atomic_read(&h
->loh_ref
) == 0);
346 cfs_hash_bd_get(s
->ls_obj_hash
, &h
->loh_fid
, &bd2
);
347 LASSERT(bd
.bd_bucket
== bd2
.bd_bucket
);
349 cfs_hash_bd_del_locked(s
->ls_obj_hash
,
351 list_move(&h
->loh_lru
, &dispose
);
353 lprocfs_counter_decr(s
->ls_stats
, LU_SS_LRU_LEN
);
357 if (nr
!= ~0 && --nr
== 0)
360 if (count
> 0 && --count
== 0)
364 cfs_hash_bd_unlock(s
->ls_obj_hash
, &bd
, 1);
367 * Free everything on the dispose list. This is safe against
368 * races due to the reasons described in lu_object_put().
370 while (!list_empty(&dispose
)) {
371 h
= container_of0(dispose
.next
,
372 struct lu_object_header
, loh_lru
);
373 list_del_init(&h
->loh_lru
);
374 lu_object_free(env
, lu_object_top(h
));
375 lprocfs_counter_incr(s
->ls_stats
, LU_SS_LRU_PURGED
);
382 if (nr
!= 0 && did_sth
&& start
!= 0) {
383 start
= 0; /* restart from the first bucket */
386 /* race on s->ls_purge_start, but nobody cares */
387 s
->ls_purge_start
= i
% CFS_HASH_NBKT(s
->ls_obj_hash
);
391 EXPORT_SYMBOL(lu_site_purge
);
396 * Code below has to jump through certain loops to output object description
397 * into libcfs_debug_msg-based log. The problem is that lu_object_print()
398 * composes object description from strings that are parts of _lines_ of
399 * output (i.e., strings that are not terminated by newline). This doesn't fit
400 * very well into libcfs_debug_msg() interface that assumes that each message
401 * supplied to it is a self-contained output line.
403 * To work around this, strings are collected in a temporary buffer
404 * (implemented as a value of lu_cdebug_key key), until terminating newline
405 * character is detected.
413 * XXX overflow is not handled correctly.
418 struct lu_cdebug_data
{
422 char lck_area
[LU_CDEBUG_LINE
];
425 /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */
426 LU_KEY_INIT_FINI(lu_global
, struct lu_cdebug_data
);
429 * Key, holding temporary buffer. This key is registered very early by
432 static struct lu_context_key lu_global_key
= {
433 .lct_tags
= LCT_MD_THREAD
| LCT_DT_THREAD
|
434 LCT_MG_THREAD
| LCT_CL_THREAD
| LCT_LOCAL
,
435 .lct_init
= lu_global_key_init
,
436 .lct_fini
= lu_global_key_fini
440 * Printer function emitting messages through libcfs_debug_msg().
442 int lu_cdebug_printer(const struct lu_env
*env
,
443 void *cookie
, const char *format
, ...)
445 struct libcfs_debug_msg_data
*msgdata
= cookie
;
446 struct lu_cdebug_data
*key
;
451 va_start(args
, format
);
453 key
= lu_context_key_get(&env
->le_ctx
, &lu_global_key
);
454 LASSERT(key
!= NULL
);
456 used
= strlen(key
->lck_area
);
457 complete
= format
[strlen(format
) - 1] == '\n';
459 * Append new chunk to the buffer.
461 vsnprintf(key
->lck_area
+ used
,
462 ARRAY_SIZE(key
->lck_area
) - used
, format
, args
);
464 if (cfs_cdebug_show(msgdata
->msg_mask
, msgdata
->msg_subsys
))
465 libcfs_debug_msg(msgdata
, "%s", key
->lck_area
);
466 key
->lck_area
[0] = 0;
471 EXPORT_SYMBOL(lu_cdebug_printer
);
474 * Print object header.
476 void lu_object_header_print(const struct lu_env
*env
, void *cookie
,
477 lu_printer_t printer
,
478 const struct lu_object_header
*hdr
)
480 (*printer
)(env
, cookie
, "header@%p[%#lx, %d, "DFID
"%s%s%s]",
481 hdr
, hdr
->loh_flags
, atomic_read(&hdr
->loh_ref
),
483 hlist_unhashed(&hdr
->loh_hash
) ? "" : " hash",
484 list_empty((struct list_head
*)&hdr
->loh_lru
) ? \
486 hdr
->loh_attr
& LOHA_EXISTS
? " exist":"");
488 EXPORT_SYMBOL(lu_object_header_print
);
491 * Print human readable representation of the \a o to the \a printer.
493 void lu_object_print(const struct lu_env
*env
, void *cookie
,
494 lu_printer_t printer
, const struct lu_object
*o
)
496 static const char ruler
[] = "........................................";
497 struct lu_object_header
*top
;
501 lu_object_header_print(env
, cookie
, printer
, top
);
502 (*printer
)(env
, cookie
, "{\n");
504 list_for_each_entry(o
, &top
->loh_layers
, lo_linkage
) {
506 * print `.' \a depth times followed by type name and address
508 (*printer
)(env
, cookie
, "%*.*s%s@%p", depth
, depth
, ruler
,
509 o
->lo_dev
->ld_type
->ldt_name
, o
);
511 if (o
->lo_ops
->loo_object_print
!= NULL
)
512 (*o
->lo_ops
->loo_object_print
)(env
, cookie
, printer
, o
);
514 (*printer
)(env
, cookie
, "\n");
517 (*printer
)(env
, cookie
, "} header@%p\n", top
);
519 EXPORT_SYMBOL(lu_object_print
);
521 static struct lu_object
*htable_lookup(struct lu_site
*s
,
522 struct cfs_hash_bd
*bd
,
523 const struct lu_fid
*f
,
524 wait_queue_t
*waiter
,
527 struct lu_site_bkt_data
*bkt
;
528 struct lu_object_header
*h
;
529 struct hlist_node
*hnode
;
530 __u64 ver
= cfs_hash_bd_version_get(bd
);
533 return ERR_PTR(-ENOENT
);
536 bkt
= cfs_hash_bd_extra_get(s
->ls_obj_hash
, bd
);
537 /* cfs_hash_bd_peek_locked is a somehow "internal" function
538 * of cfs_hash, it doesn't add refcount on object. */
539 hnode
= cfs_hash_bd_peek_locked(s
->ls_obj_hash
, bd
, (void *)f
);
541 lprocfs_counter_incr(s
->ls_stats
, LU_SS_CACHE_MISS
);
542 return ERR_PTR(-ENOENT
);
545 h
= container_of0(hnode
, struct lu_object_header
, loh_hash
);
546 if (likely(!lu_object_is_dying(h
))) {
547 cfs_hash_get(s
->ls_obj_hash
, hnode
);
548 lprocfs_counter_incr(s
->ls_stats
, LU_SS_CACHE_HIT
);
549 if (!list_empty(&h
->loh_lru
)) {
550 list_del_init(&h
->loh_lru
);
552 lprocfs_counter_decr(s
->ls_stats
, LU_SS_LRU_LEN
);
554 return lu_object_top(h
);
558 * Lookup found an object being destroyed this object cannot be
559 * returned (to assure that references to dying objects are eventually
560 * drained), and moreover, lookup has to wait until object is freed.
563 init_waitqueue_entry(waiter
, current
);
564 add_wait_queue(&bkt
->lsb_marche_funebre
, waiter
);
565 set_current_state(TASK_UNINTERRUPTIBLE
);
566 lprocfs_counter_incr(s
->ls_stats
, LU_SS_CACHE_DEATH_RACE
);
567 return ERR_PTR(-EAGAIN
);
571 * Search cache for an object with the fid \a f. If such object is found,
572 * return it. Otherwise, create new object, insert it into cache and return
573 * it. In any case, additional reference is acquired on the returned object.
575 static struct lu_object
*lu_object_find(const struct lu_env
*env
,
576 struct lu_device
*dev
,
577 const struct lu_fid
*f
,
578 const struct lu_object_conf
*conf
)
580 return lu_object_find_at(env
, dev
->ld_site
->ls_top_dev
, f
, conf
);
583 static struct lu_object
*lu_object_new(const struct lu_env
*env
,
584 struct lu_device
*dev
,
585 const struct lu_fid
*f
,
586 const struct lu_object_conf
*conf
)
590 struct cfs_hash_bd bd
;
592 o
= lu_object_alloc(env
, dev
, f
, conf
);
596 hs
= dev
->ld_site
->ls_obj_hash
;
597 cfs_hash_bd_get_and_lock(hs
, (void *)f
, &bd
, 1);
598 cfs_hash_bd_add_locked(hs
, &bd
, &o
->lo_header
->loh_hash
);
599 cfs_hash_bd_unlock(hs
, &bd
, 1);
604 * Core logic of lu_object_find*() functions.
606 static struct lu_object
*lu_object_find_try(const struct lu_env
*env
,
607 struct lu_device
*dev
,
608 const struct lu_fid
*f
,
609 const struct lu_object_conf
*conf
,
610 wait_queue_t
*waiter
)
613 struct lu_object
*shadow
;
616 struct cfs_hash_bd bd
;
620 * This uses standard index maintenance protocol:
622 * - search index under lock, and return object if found;
623 * - otherwise, unlock index, allocate new object;
624 * - lock index and search again;
625 * - if nothing is found (usual case), insert newly created
627 * - otherwise (race: other thread inserted object), free
628 * object just allocated.
632 * For "LOC_F_NEW" case, we are sure the object is new established.
633 * It is unnecessary to perform lookup-alloc-lookup-insert, instead,
634 * just alloc and insert directly.
636 * If dying object is found during index search, add @waiter to the
637 * site wait-queue and return ERR_PTR(-EAGAIN).
639 if (conf
!= NULL
&& conf
->loc_flags
& LOC_F_NEW
)
640 return lu_object_new(env
, dev
, f
, conf
);
644 cfs_hash_bd_get_and_lock(hs
, (void *)f
, &bd
, 1);
645 o
= htable_lookup(s
, &bd
, f
, waiter
, &version
);
646 cfs_hash_bd_unlock(hs
, &bd
, 1);
647 if (!IS_ERR(o
) || PTR_ERR(o
) != -ENOENT
)
651 * Allocate new object. This may result in rather complicated
652 * operations, including fld queries, inode loading, etc.
654 o
= lu_object_alloc(env
, dev
, f
, conf
);
658 LASSERT(lu_fid_eq(lu_object_fid(o
), f
));
660 cfs_hash_bd_lock(hs
, &bd
, 1);
662 shadow
= htable_lookup(s
, &bd
, f
, waiter
, &version
);
663 if (likely(PTR_ERR(shadow
) == -ENOENT
)) {
664 cfs_hash_bd_add_locked(hs
, &bd
, &o
->lo_header
->loh_hash
);
665 cfs_hash_bd_unlock(hs
, &bd
, 1);
669 lprocfs_counter_incr(s
->ls_stats
, LU_SS_CACHE_RACE
);
670 cfs_hash_bd_unlock(hs
, &bd
, 1);
671 lu_object_free(env
, o
);
676 * Much like lu_object_find(), but top level device of object is specifically
677 * \a dev rather than top level device of the site. This interface allows
678 * objects of different "stacking" to be created within the same site.
680 struct lu_object
*lu_object_find_at(const struct lu_env
*env
,
681 struct lu_device
*dev
,
682 const struct lu_fid
*f
,
683 const struct lu_object_conf
*conf
)
685 struct lu_site_bkt_data
*bkt
;
686 struct lu_object
*obj
;
690 obj
= lu_object_find_try(env
, dev
, f
, conf
, &wait
);
691 if (obj
!= ERR_PTR(-EAGAIN
))
694 * lu_object_find_try() already added waiter into the
698 bkt
= lu_site_bkt_from_fid(dev
->ld_site
, (void *)f
);
699 remove_wait_queue(&bkt
->lsb_marche_funebre
, &wait
);
702 EXPORT_SYMBOL(lu_object_find_at
);
705 * Find object with given fid, and return its slice belonging to given device.
707 struct lu_object
*lu_object_find_slice(const struct lu_env
*env
,
708 struct lu_device
*dev
,
709 const struct lu_fid
*f
,
710 const struct lu_object_conf
*conf
)
712 struct lu_object
*top
;
713 struct lu_object
*obj
;
715 top
= lu_object_find(env
, dev
, f
, conf
);
717 obj
= lu_object_locate(top
->lo_header
, dev
->ld_type
);
719 lu_object_put(env
, top
);
724 EXPORT_SYMBOL(lu_object_find_slice
);
727 * Global list of all device types.
729 static LIST_HEAD(lu_device_types
);
731 int lu_device_type_init(struct lu_device_type
*ldt
)
735 INIT_LIST_HEAD(&ldt
->ldt_linkage
);
736 if (ldt
->ldt_ops
->ldto_init
)
737 result
= ldt
->ldt_ops
->ldto_init(ldt
);
739 list_add(&ldt
->ldt_linkage
, &lu_device_types
);
742 EXPORT_SYMBOL(lu_device_type_init
);
744 void lu_device_type_fini(struct lu_device_type
*ldt
)
746 list_del_init(&ldt
->ldt_linkage
);
747 if (ldt
->ldt_ops
->ldto_fini
)
748 ldt
->ldt_ops
->ldto_fini(ldt
);
750 EXPORT_SYMBOL(lu_device_type_fini
);
752 void lu_types_stop(void)
754 struct lu_device_type
*ldt
;
756 list_for_each_entry(ldt
, &lu_device_types
, ldt_linkage
) {
757 if (ldt
->ldt_device_nr
== 0 && ldt
->ldt_ops
->ldto_stop
)
758 ldt
->ldt_ops
->ldto_stop(ldt
);
761 EXPORT_SYMBOL(lu_types_stop
);
764 * Global list of all sites on this node
766 static LIST_HEAD(lu_sites
);
767 static DEFINE_MUTEX(lu_sites_guard
);
770 * Global environment used by site shrinker.
772 static struct lu_env lu_shrink_env
;
774 struct lu_site_print_arg
{
775 struct lu_env
*lsp_env
;
777 lu_printer_t lsp_printer
;
781 lu_site_obj_print(struct cfs_hash
*hs
, struct cfs_hash_bd
*bd
,
782 struct hlist_node
*hnode
, void *data
)
784 struct lu_site_print_arg
*arg
= (struct lu_site_print_arg
*)data
;
785 struct lu_object_header
*h
;
787 h
= hlist_entry(hnode
, struct lu_object_header
, loh_hash
);
788 if (!list_empty(&h
->loh_layers
)) {
789 const struct lu_object
*o
;
791 o
= lu_object_top(h
);
792 lu_object_print(arg
->lsp_env
, arg
->lsp_cookie
,
793 arg
->lsp_printer
, o
);
795 lu_object_header_print(arg
->lsp_env
, arg
->lsp_cookie
,
796 arg
->lsp_printer
, h
);
802 * Print all objects in \a s.
804 void lu_site_print(const struct lu_env
*env
, struct lu_site
*s
, void *cookie
,
805 lu_printer_t printer
)
807 struct lu_site_print_arg arg
= {
808 .lsp_env
= (struct lu_env
*)env
,
809 .lsp_cookie
= cookie
,
810 .lsp_printer
= printer
,
813 cfs_hash_for_each(s
->ls_obj_hash
, lu_site_obj_print
, &arg
);
815 EXPORT_SYMBOL(lu_site_print
);
818 LU_CACHE_PERCENT_MAX
= 50,
819 LU_CACHE_PERCENT_DEFAULT
= 20
822 static unsigned int lu_cache_percent
= LU_CACHE_PERCENT_DEFAULT
;
823 module_param(lu_cache_percent
, int, 0644);
824 MODULE_PARM_DESC(lu_cache_percent
, "Percentage of memory to be used as lu_object cache");
827 * Return desired hash table order.
829 static int lu_htable_order(void)
831 unsigned long cache_size
;
835 * Calculate hash table size, assuming that we want reasonable
836 * performance when 20% of total memory is occupied by cache of
839 * Size of lu_object is (arbitrary) taken as 1K (together with inode).
841 cache_size
= totalram_pages
;
843 #if BITS_PER_LONG == 32
844 /* limit hashtable size for lowmem systems to low RAM */
845 if (cache_size
> 1 << (30 - PAGE_CACHE_SHIFT
))
846 cache_size
= 1 << (30 - PAGE_CACHE_SHIFT
) * 3 / 4;
849 /* clear off unreasonable cache setting. */
850 if (lu_cache_percent
== 0 || lu_cache_percent
> LU_CACHE_PERCENT_MAX
) {
851 CWARN("obdclass: invalid lu_cache_percent: %u, it must be in the range of (0, %u]. Will use default value: %u.\n",
852 lu_cache_percent
, LU_CACHE_PERCENT_MAX
,
853 LU_CACHE_PERCENT_DEFAULT
);
855 lu_cache_percent
= LU_CACHE_PERCENT_DEFAULT
;
857 cache_size
= cache_size
/ 100 * lu_cache_percent
*
858 (PAGE_CACHE_SIZE
/ 1024);
860 for (bits
= 1; (1 << bits
) < cache_size
; ++bits
) {
866 static unsigned lu_obj_hop_hash(struct cfs_hash
*hs
,
867 const void *key
, unsigned mask
)
869 struct lu_fid
*fid
= (struct lu_fid
*)key
;
872 hash
= fid_flatten32(fid
);
873 hash
+= (hash
>> 4) + (hash
<< 12); /* mixing oid and seq */
874 hash
= hash_long(hash
, hs
->hs_bkt_bits
);
876 /* give me another random factor */
877 hash
-= hash_long((unsigned long)hs
, fid_oid(fid
) % 11 + 3);
879 hash
<<= hs
->hs_cur_bits
- hs
->hs_bkt_bits
;
880 hash
|= (fid_seq(fid
) + fid_oid(fid
)) & (CFS_HASH_NBKT(hs
) - 1);
885 static void *lu_obj_hop_object(struct hlist_node
*hnode
)
887 return hlist_entry(hnode
, struct lu_object_header
, loh_hash
);
890 static void *lu_obj_hop_key(struct hlist_node
*hnode
)
892 struct lu_object_header
*h
;
894 h
= hlist_entry(hnode
, struct lu_object_header
, loh_hash
);
898 static int lu_obj_hop_keycmp(const void *key
, struct hlist_node
*hnode
)
900 struct lu_object_header
*h
;
902 h
= hlist_entry(hnode
, struct lu_object_header
, loh_hash
);
903 return lu_fid_eq(&h
->loh_fid
, (struct lu_fid
*)key
);
906 static void lu_obj_hop_get(struct cfs_hash
*hs
, struct hlist_node
*hnode
)
908 struct lu_object_header
*h
;
910 h
= hlist_entry(hnode
, struct lu_object_header
, loh_hash
);
911 atomic_inc(&h
->loh_ref
);
914 static void lu_obj_hop_put_locked(struct cfs_hash
*hs
, struct hlist_node
*hnode
)
916 LBUG(); /* we should never called it */
919 static struct cfs_hash_ops lu_site_hash_ops
= {
920 .hs_hash
= lu_obj_hop_hash
,
921 .hs_key
= lu_obj_hop_key
,
922 .hs_keycmp
= lu_obj_hop_keycmp
,
923 .hs_object
= lu_obj_hop_object
,
924 .hs_get
= lu_obj_hop_get
,
925 .hs_put_locked
= lu_obj_hop_put_locked
,
928 static void lu_dev_add_linkage(struct lu_site
*s
, struct lu_device
*d
)
930 spin_lock(&s
->ls_ld_lock
);
931 if (list_empty(&d
->ld_linkage
))
932 list_add(&d
->ld_linkage
, &s
->ls_ld_linkage
);
933 spin_unlock(&s
->ls_ld_lock
);
937 * Initialize site \a s, with \a d as the top level device.
939 #define LU_SITE_BITS_MIN 12
940 #define LU_SITE_BITS_MAX 24
942 * total 256 buckets, we don't want too many buckets because:
943 * - consume too much memory
944 * - avoid unbalanced LRU list
946 #define LU_SITE_BKT_BITS 8
948 int lu_site_init(struct lu_site
*s
, struct lu_device
*top
)
950 struct lu_site_bkt_data
*bkt
;
951 struct cfs_hash_bd bd
;
956 memset(s
, 0, sizeof(*s
));
957 bits
= lu_htable_order();
958 snprintf(name
, 16, "lu_site_%s", top
->ld_type
->ldt_name
);
959 for (bits
= min(max(LU_SITE_BITS_MIN
, bits
), LU_SITE_BITS_MAX
);
960 bits
>= LU_SITE_BITS_MIN
; bits
--) {
961 s
->ls_obj_hash
= cfs_hash_create(name
, bits
, bits
,
962 bits
- LU_SITE_BKT_BITS
,
965 CFS_HASH_SPIN_BKTLOCK
|
966 CFS_HASH_NO_ITEMREF
|
968 CFS_HASH_ASSERT_EMPTY
);
969 if (s
->ls_obj_hash
!= NULL
)
973 if (s
->ls_obj_hash
== NULL
) {
974 CERROR("failed to create lu_site hash with bits: %d\n", bits
);
978 cfs_hash_for_each_bucket(s
->ls_obj_hash
, &bd
, i
) {
979 bkt
= cfs_hash_bd_extra_get(s
->ls_obj_hash
, &bd
);
980 INIT_LIST_HEAD(&bkt
->lsb_lru
);
981 init_waitqueue_head(&bkt
->lsb_marche_funebre
);
984 s
->ls_stats
= lprocfs_alloc_stats(LU_SS_LAST_STAT
, 0);
985 if (s
->ls_stats
== NULL
) {
986 cfs_hash_putref(s
->ls_obj_hash
);
987 s
->ls_obj_hash
= NULL
;
991 lprocfs_counter_init(s
->ls_stats
, LU_SS_CREATED
,
992 0, "created", "created");
993 lprocfs_counter_init(s
->ls_stats
, LU_SS_CACHE_HIT
,
994 0, "cache_hit", "cache_hit");
995 lprocfs_counter_init(s
->ls_stats
, LU_SS_CACHE_MISS
,
996 0, "cache_miss", "cache_miss");
997 lprocfs_counter_init(s
->ls_stats
, LU_SS_CACHE_RACE
,
998 0, "cache_race", "cache_race");
999 lprocfs_counter_init(s
->ls_stats
, LU_SS_CACHE_DEATH_RACE
,
1000 0, "cache_death_race", "cache_death_race");
1001 lprocfs_counter_init(s
->ls_stats
, LU_SS_LRU_PURGED
,
1002 0, "lru_purged", "lru_purged");
1004 * Unlike other counters, lru_len can be decremented so
1005 * need lc_sum instead of just lc_count
1007 lprocfs_counter_init(s
->ls_stats
, LU_SS_LRU_LEN
,
1008 LPROCFS_CNTR_AVGMINMAX
, "lru_len", "lru_len");
1010 INIT_LIST_HEAD(&s
->ls_linkage
);
1011 s
->ls_top_dev
= top
;
1014 lu_ref_add(&top
->ld_reference
, "site-top", s
);
1016 INIT_LIST_HEAD(&s
->ls_ld_linkage
);
1017 spin_lock_init(&s
->ls_ld_lock
);
1019 lu_dev_add_linkage(s
, top
);
1023 EXPORT_SYMBOL(lu_site_init
);
1026 * Finalize \a s and release its resources.
1028 void lu_site_fini(struct lu_site
*s
)
1030 mutex_lock(&lu_sites_guard
);
1031 list_del_init(&s
->ls_linkage
);
1032 mutex_unlock(&lu_sites_guard
);
1034 if (s
->ls_obj_hash
!= NULL
) {
1035 cfs_hash_putref(s
->ls_obj_hash
);
1036 s
->ls_obj_hash
= NULL
;
1039 if (s
->ls_top_dev
!= NULL
) {
1040 s
->ls_top_dev
->ld_site
= NULL
;
1041 lu_ref_del(&s
->ls_top_dev
->ld_reference
, "site-top", s
);
1042 lu_device_put(s
->ls_top_dev
);
1043 s
->ls_top_dev
= NULL
;
1046 if (s
->ls_stats
!= NULL
)
1047 lprocfs_free_stats(&s
->ls_stats
);
1049 EXPORT_SYMBOL(lu_site_fini
);
1052 * Called when initialization of stack for this site is completed.
1054 int lu_site_init_finish(struct lu_site
*s
)
1058 mutex_lock(&lu_sites_guard
);
1059 result
= lu_context_refill(&lu_shrink_env
.le_ctx
);
1061 list_add(&s
->ls_linkage
, &lu_sites
);
1062 mutex_unlock(&lu_sites_guard
);
1065 EXPORT_SYMBOL(lu_site_init_finish
);
1068 * Acquire additional reference on device \a d
1070 void lu_device_get(struct lu_device
*d
)
1072 atomic_inc(&d
->ld_ref
);
1074 EXPORT_SYMBOL(lu_device_get
);
1077 * Release reference on device \a d.
1079 void lu_device_put(struct lu_device
*d
)
1081 LASSERT(atomic_read(&d
->ld_ref
) > 0);
1082 atomic_dec(&d
->ld_ref
);
1084 EXPORT_SYMBOL(lu_device_put
);
1087 * Initialize device \a d of type \a t.
1089 int lu_device_init(struct lu_device
*d
, struct lu_device_type
*t
)
1091 if (t
->ldt_device_nr
++ == 0 && t
->ldt_ops
->ldto_start
!= NULL
)
1092 t
->ldt_ops
->ldto_start(t
);
1093 memset(d
, 0, sizeof(*d
));
1094 atomic_set(&d
->ld_ref
, 0);
1096 lu_ref_init(&d
->ld_reference
);
1097 INIT_LIST_HEAD(&d
->ld_linkage
);
1100 EXPORT_SYMBOL(lu_device_init
);
1103 * Finalize device \a d.
1105 void lu_device_fini(struct lu_device
*d
)
1107 struct lu_device_type
*t
;
1110 if (d
->ld_obd
!= NULL
) {
1111 d
->ld_obd
->obd_lu_dev
= NULL
;
1115 lu_ref_fini(&d
->ld_reference
);
1116 LASSERTF(atomic_read(&d
->ld_ref
) == 0,
1117 "Refcount is %u\n", atomic_read(&d
->ld_ref
));
1118 LASSERT(t
->ldt_device_nr
> 0);
1119 if (--t
->ldt_device_nr
== 0 && t
->ldt_ops
->ldto_stop
!= NULL
)
1120 t
->ldt_ops
->ldto_stop(t
);
1122 EXPORT_SYMBOL(lu_device_fini
);
1125 * Initialize object \a o that is part of compound object \a h and was created
1128 int lu_object_init(struct lu_object
*o
, struct lu_object_header
*h
,
1129 struct lu_device
*d
)
1131 memset(o
, 0, sizeof(*o
));
1135 lu_ref_add_at(&d
->ld_reference
, &o
->lo_dev_ref
, "lu_object", o
);
1136 INIT_LIST_HEAD(&o
->lo_linkage
);
1140 EXPORT_SYMBOL(lu_object_init
);
1143 * Finalize object and release its resources.
1145 void lu_object_fini(struct lu_object
*o
)
1147 struct lu_device
*dev
= o
->lo_dev
;
1149 LASSERT(list_empty(&o
->lo_linkage
));
1152 lu_ref_del_at(&dev
->ld_reference
, &o
->lo_dev_ref
,
1158 EXPORT_SYMBOL(lu_object_fini
);
1161 * Add object \a o as first layer of compound object \a h
1163 * This is typically called by the ->ldo_object_alloc() method of top-level
1166 void lu_object_add_top(struct lu_object_header
*h
, struct lu_object
*o
)
1168 list_move(&o
->lo_linkage
, &h
->loh_layers
);
1170 EXPORT_SYMBOL(lu_object_add_top
);
1173 * Add object \a o as a layer of compound object, going after \a before.
1175 * This is typically called by the ->ldo_object_alloc() method of \a
1178 void lu_object_add(struct lu_object
*before
, struct lu_object
*o
)
1180 list_move(&o
->lo_linkage
, &before
->lo_linkage
);
1182 EXPORT_SYMBOL(lu_object_add
);
1185 * Initialize compound object.
1187 int lu_object_header_init(struct lu_object_header
*h
)
1189 memset(h
, 0, sizeof(*h
));
1190 atomic_set(&h
->loh_ref
, 1);
1191 INIT_HLIST_NODE(&h
->loh_hash
);
1192 INIT_LIST_HEAD(&h
->loh_lru
);
1193 INIT_LIST_HEAD(&h
->loh_layers
);
1194 lu_ref_init(&h
->loh_reference
);
1197 EXPORT_SYMBOL(lu_object_header_init
);
1200 * Finalize compound object.
1202 void lu_object_header_fini(struct lu_object_header
*h
)
1204 LASSERT(list_empty(&h
->loh_layers
));
1205 LASSERT(list_empty(&h
->loh_lru
));
1206 LASSERT(hlist_unhashed(&h
->loh_hash
));
1207 lu_ref_fini(&h
->loh_reference
);
1209 EXPORT_SYMBOL(lu_object_header_fini
);
1212 * Given a compound object, find its slice, corresponding to the device type
1215 struct lu_object
*lu_object_locate(struct lu_object_header
*h
,
1216 const struct lu_device_type
*dtype
)
1218 struct lu_object
*o
;
1220 list_for_each_entry(o
, &h
->loh_layers
, lo_linkage
) {
1221 if (o
->lo_dev
->ld_type
== dtype
)
1226 EXPORT_SYMBOL(lu_object_locate
);
1229 * Finalize and free devices in the device stack.
1231 * Finalize device stack by purging object cache, and calling
1232 * lu_device_type_operations::ldto_device_fini() and
1233 * lu_device_type_operations::ldto_device_free() on all devices in the stack.
1235 void lu_stack_fini(const struct lu_env
*env
, struct lu_device
*top
)
1237 struct lu_site
*site
= top
->ld_site
;
1238 struct lu_device
*scan
;
1239 struct lu_device
*next
;
1241 lu_site_purge(env
, site
, ~0);
1242 for (scan
= top
; scan
!= NULL
; scan
= next
) {
1243 next
= scan
->ld_type
->ldt_ops
->ldto_device_fini(env
, scan
);
1244 lu_ref_del(&scan
->ld_reference
, "lu-stack", &lu_site_init
);
1245 lu_device_put(scan
);
1249 lu_site_purge(env
, site
, ~0);
1251 for (scan
= top
; scan
!= NULL
; scan
= next
) {
1252 const struct lu_device_type
*ldt
= scan
->ld_type
;
1253 struct obd_type
*type
;
1255 next
= ldt
->ldt_ops
->ldto_device_free(env
, scan
);
1256 type
= ldt
->ldt_obd_type
;
1259 class_put_type(type
);
1263 EXPORT_SYMBOL(lu_stack_fini
);
1267 * Maximal number of tld slots.
1269 LU_CONTEXT_KEY_NR
= 40
1272 static struct lu_context_key
*lu_keys
[LU_CONTEXT_KEY_NR
] = { NULL
, };
1274 static DEFINE_SPINLOCK(lu_keys_guard
);
1277 * Global counter incremented whenever key is registered, unregistered,
1278 * revived or quiesced. This is used to void unnecessary calls to
1279 * lu_context_refill(). No locking is provided, as initialization and shutdown
1280 * are supposed to be externally serialized.
1282 static unsigned key_set_version
;
1287 int lu_context_key_register(struct lu_context_key
*key
)
1292 LASSERT(key
->lct_init
!= NULL
);
1293 LASSERT(key
->lct_fini
!= NULL
);
1294 LASSERT(key
->lct_tags
!= 0);
1297 spin_lock(&lu_keys_guard
);
1298 for (i
= 0; i
< ARRAY_SIZE(lu_keys
); ++i
) {
1299 if (lu_keys
[i
] == NULL
) {
1301 atomic_set(&key
->lct_used
, 1);
1303 lu_ref_init(&key
->lct_reference
);
1309 spin_unlock(&lu_keys_guard
);
1312 EXPORT_SYMBOL(lu_context_key_register
);
1314 static void key_fini(struct lu_context
*ctx
, int index
)
1316 if (ctx
->lc_value
!= NULL
&& ctx
->lc_value
[index
] != NULL
) {
1317 struct lu_context_key
*key
;
1319 key
= lu_keys
[index
];
1320 LASSERT(key
!= NULL
);
1321 LASSERT(key
->lct_fini
!= NULL
);
1322 LASSERT(atomic_read(&key
->lct_used
) > 1);
1324 key
->lct_fini(ctx
, key
, ctx
->lc_value
[index
]);
1325 lu_ref_del(&key
->lct_reference
, "ctx", ctx
);
1326 atomic_dec(&key
->lct_used
);
1328 if ((ctx
->lc_tags
& LCT_NOREF
) == 0) {
1329 #ifdef CONFIG_MODULE_UNLOAD
1330 LINVRNT(module_refcount(key
->lct_owner
) > 0);
1332 module_put(key
->lct_owner
);
1334 ctx
->lc_value
[index
] = NULL
;
1341 void lu_context_key_degister(struct lu_context_key
*key
)
1343 LASSERT(atomic_read(&key
->lct_used
) >= 1);
1344 LINVRNT(0 <= key
->lct_index
&& key
->lct_index
< ARRAY_SIZE(lu_keys
));
1346 lu_context_key_quiesce(key
);
1349 spin_lock(&lu_keys_guard
);
1350 key_fini(&lu_shrink_env
.le_ctx
, key
->lct_index
);
1351 if (lu_keys
[key
->lct_index
]) {
1352 lu_keys
[key
->lct_index
] = NULL
;
1353 lu_ref_fini(&key
->lct_reference
);
1355 spin_unlock(&lu_keys_guard
);
1357 LASSERTF(atomic_read(&key
->lct_used
) == 1,
1358 "key has instances: %d\n",
1359 atomic_read(&key
->lct_used
));
1361 EXPORT_SYMBOL(lu_context_key_degister
);
1364 * Register a number of keys. This has to be called after all keys have been
1365 * initialized by a call to LU_CONTEXT_KEY_INIT().
1367 int lu_context_key_register_many(struct lu_context_key
*k
, ...)
1369 struct lu_context_key
*key
= k
;
1375 result
= lu_context_key_register(key
);
1378 key
= va_arg(args
, struct lu_context_key
*);
1379 } while (key
!= NULL
);
1385 lu_context_key_degister(k
);
1386 k
= va_arg(args
, struct lu_context_key
*);
1393 EXPORT_SYMBOL(lu_context_key_register_many
);
1396 * De-register a number of keys. This is a dual to
1397 * lu_context_key_register_many().
1399 void lu_context_key_degister_many(struct lu_context_key
*k
, ...)
1405 lu_context_key_degister(k
);
1406 k
= va_arg(args
, struct lu_context_key
*);
1407 } while (k
!= NULL
);
1410 EXPORT_SYMBOL(lu_context_key_degister_many
);
1413 * Revive a number of keys.
1415 void lu_context_key_revive_many(struct lu_context_key
*k
, ...)
1421 lu_context_key_revive(k
);
1422 k
= va_arg(args
, struct lu_context_key
*);
1423 } while (k
!= NULL
);
1426 EXPORT_SYMBOL(lu_context_key_revive_many
);
1429 * Quiescent a number of keys.
1431 void lu_context_key_quiesce_many(struct lu_context_key
*k
, ...)
1437 lu_context_key_quiesce(k
);
1438 k
= va_arg(args
, struct lu_context_key
*);
1439 } while (k
!= NULL
);
1442 EXPORT_SYMBOL(lu_context_key_quiesce_many
);
1445 * Return value associated with key \a key in context \a ctx.
1447 void *lu_context_key_get(const struct lu_context
*ctx
,
1448 const struct lu_context_key
*key
)
1450 LINVRNT(ctx
->lc_state
== LCS_ENTERED
);
1451 LINVRNT(0 <= key
->lct_index
&& key
->lct_index
< ARRAY_SIZE(lu_keys
));
1452 LASSERT(lu_keys
[key
->lct_index
] == key
);
1453 return ctx
->lc_value
[key
->lct_index
];
1455 EXPORT_SYMBOL(lu_context_key_get
);
1458 * List of remembered contexts. XXX document me.
1460 static LIST_HEAD(lu_context_remembered
);
1463 * Destroy \a key in all remembered contexts. This is used to destroy key
1464 * values in "shared" contexts (like service threads), when a module owning
1465 * the key is about to be unloaded.
1467 void lu_context_key_quiesce(struct lu_context_key
*key
)
1469 struct lu_context
*ctx
;
1471 if (!(key
->lct_tags
& LCT_QUIESCENT
)) {
1473 * XXX layering violation.
1475 key
->lct_tags
|= LCT_QUIESCENT
;
1477 * XXX memory barrier has to go here.
1479 spin_lock(&lu_keys_guard
);
1480 list_for_each_entry(ctx
, &lu_context_remembered
,
1482 key_fini(ctx
, key
->lct_index
);
1483 spin_unlock(&lu_keys_guard
);
1487 EXPORT_SYMBOL(lu_context_key_quiesce
);
1489 void lu_context_key_revive(struct lu_context_key
*key
)
1491 key
->lct_tags
&= ~LCT_QUIESCENT
;
1494 EXPORT_SYMBOL(lu_context_key_revive
);
1496 static void keys_fini(struct lu_context
*ctx
)
1500 if (ctx
->lc_value
== NULL
)
1503 for (i
= 0; i
< ARRAY_SIZE(lu_keys
); ++i
)
1506 kfree(ctx
->lc_value
);
1507 ctx
->lc_value
= NULL
;
1510 static int keys_fill(struct lu_context
*ctx
)
1514 LINVRNT(ctx
->lc_value
!= NULL
);
1515 for (i
= 0; i
< ARRAY_SIZE(lu_keys
); ++i
) {
1516 struct lu_context_key
*key
;
1519 if (ctx
->lc_value
[i
] == NULL
&& key
!= NULL
&&
1520 (key
->lct_tags
& ctx
->lc_tags
) &&
1522 * Don't create values for a LCT_QUIESCENT key, as this
1523 * will pin module owning a key.
1525 !(key
->lct_tags
& LCT_QUIESCENT
)) {
1528 LINVRNT(key
->lct_init
!= NULL
);
1529 LINVRNT(key
->lct_index
== i
);
1531 value
= key
->lct_init(ctx
, key
);
1533 return PTR_ERR(value
);
1535 if (!(ctx
->lc_tags
& LCT_NOREF
))
1536 try_module_get(key
->lct_owner
);
1537 lu_ref_add_atomic(&key
->lct_reference
, "ctx", ctx
);
1538 atomic_inc(&key
->lct_used
);
1540 * This is the only place in the code, where an
1541 * element of ctx->lc_value[] array is set to non-NULL
1544 ctx
->lc_value
[i
] = value
;
1545 if (key
->lct_exit
!= NULL
)
1546 ctx
->lc_tags
|= LCT_HAS_EXIT
;
1548 ctx
->lc_version
= key_set_version
;
1553 static int keys_init(struct lu_context
*ctx
)
1555 ctx
->lc_value
= kcalloc(ARRAY_SIZE(lu_keys
), sizeof(ctx
->lc_value
[0]),
1557 if (likely(ctx
->lc_value
!= NULL
))
1558 return keys_fill(ctx
);
1564 * Initialize context data-structure. Create values for all keys.
1566 int lu_context_init(struct lu_context
*ctx
, __u32 tags
)
1570 memset(ctx
, 0, sizeof(*ctx
));
1571 ctx
->lc_state
= LCS_INITIALIZED
;
1572 ctx
->lc_tags
= tags
;
1573 if (tags
& LCT_REMEMBER
) {
1574 spin_lock(&lu_keys_guard
);
1575 list_add(&ctx
->lc_remember
, &lu_context_remembered
);
1576 spin_unlock(&lu_keys_guard
);
1578 INIT_LIST_HEAD(&ctx
->lc_remember
);
1581 rc
= keys_init(ctx
);
1583 lu_context_fini(ctx
);
1587 EXPORT_SYMBOL(lu_context_init
);
1590 * Finalize context data-structure. Destroy key values.
1592 void lu_context_fini(struct lu_context
*ctx
)
1594 LINVRNT(ctx
->lc_state
== LCS_INITIALIZED
|| ctx
->lc_state
== LCS_LEFT
);
1595 ctx
->lc_state
= LCS_FINALIZED
;
1597 if ((ctx
->lc_tags
& LCT_REMEMBER
) == 0) {
1598 LASSERT(list_empty(&ctx
->lc_remember
));
1601 } else { /* could race with key degister */
1602 spin_lock(&lu_keys_guard
);
1604 list_del_init(&ctx
->lc_remember
);
1605 spin_unlock(&lu_keys_guard
);
1608 EXPORT_SYMBOL(lu_context_fini
);
1611 * Called before entering context.
1613 void lu_context_enter(struct lu_context
*ctx
)
1615 LINVRNT(ctx
->lc_state
== LCS_INITIALIZED
|| ctx
->lc_state
== LCS_LEFT
);
1616 ctx
->lc_state
= LCS_ENTERED
;
1618 EXPORT_SYMBOL(lu_context_enter
);
1621 * Called after exiting from \a ctx
1623 void lu_context_exit(struct lu_context
*ctx
)
1627 LINVRNT(ctx
->lc_state
== LCS_ENTERED
);
1628 ctx
->lc_state
= LCS_LEFT
;
1629 if (ctx
->lc_tags
& LCT_HAS_EXIT
&& ctx
->lc_value
!= NULL
) {
1630 for (i
= 0; i
< ARRAY_SIZE(lu_keys
); ++i
) {
1631 if (ctx
->lc_value
[i
] != NULL
) {
1632 struct lu_context_key
*key
;
1635 LASSERT(key
!= NULL
);
1636 if (key
->lct_exit
!= NULL
)
1638 key
, ctx
->lc_value
[i
]);
1643 EXPORT_SYMBOL(lu_context_exit
);
1646 * Allocate for context all missing keys that were registered after context
1647 * creation. key_set_version is only changed in rare cases when modules
1648 * are loaded and removed.
1650 int lu_context_refill(struct lu_context
*ctx
)
1652 return likely(ctx
->lc_version
== key_set_version
) ? 0 : keys_fill(ctx
);
1654 EXPORT_SYMBOL(lu_context_refill
);
1657 * lu_ctx_tags/lu_ses_tags will be updated if there are new types of
1658 * obd being added. Currently, this is only used on client side, specifically
1659 * for echo device client, for other stack (like ptlrpc threads), context are
1660 * predefined when the lu_device type are registered, during the module probe
1663 __u32 lu_context_tags_default
;
1664 __u32 lu_session_tags_default
;
1666 int lu_env_init(struct lu_env
*env
, __u32 tags
)
1671 result
= lu_context_init(&env
->le_ctx
, tags
);
1672 if (likely(result
== 0))
1673 lu_context_enter(&env
->le_ctx
);
1676 EXPORT_SYMBOL(lu_env_init
);
1678 void lu_env_fini(struct lu_env
*env
)
1680 lu_context_exit(&env
->le_ctx
);
1681 lu_context_fini(&env
->le_ctx
);
1684 EXPORT_SYMBOL(lu_env_fini
);
1686 int lu_env_refill(struct lu_env
*env
)
1690 result
= lu_context_refill(&env
->le_ctx
);
1691 if (result
== 0 && env
->le_ses
!= NULL
)
1692 result
= lu_context_refill(env
->le_ses
);
1695 EXPORT_SYMBOL(lu_env_refill
);
1697 struct lu_site_stats
{
1698 unsigned lss_populated
;
1699 unsigned lss_max_search
;
1704 static void lu_site_stats_get(struct cfs_hash
*hs
,
1705 struct lu_site_stats
*stats
, int populated
)
1707 struct cfs_hash_bd bd
;
1710 cfs_hash_for_each_bucket(hs
, &bd
, i
) {
1711 struct lu_site_bkt_data
*bkt
= cfs_hash_bd_extra_get(hs
, &bd
);
1712 struct hlist_head
*hhead
;
1714 cfs_hash_bd_lock(hs
, &bd
, 1);
1716 cfs_hash_bd_count_get(&bd
) - bkt
->lsb_lru_len
;
1717 stats
->lss_total
+= cfs_hash_bd_count_get(&bd
);
1718 stats
->lss_max_search
= max((int)stats
->lss_max_search
,
1719 cfs_hash_bd_depmax_get(&bd
));
1721 cfs_hash_bd_unlock(hs
, &bd
, 1);
1725 cfs_hash_bd_for_each_hlist(hs
, &bd
, hhead
) {
1726 if (!hlist_empty(hhead
))
1727 stats
->lss_populated
++;
1729 cfs_hash_bd_unlock(hs
, &bd
, 1);
1734 * lu_cache_shrink_count returns the number of cached objects that are
1735 * candidates to be freed by shrink_slab(). A counter, which tracks
1736 * the number of items in the site's lru, is maintained in the per cpu
1737 * stats of each site. The counter is incremented when an object is added
1738 * to a site's lru and decremented when one is removed. The number of
1739 * free-able objects is the sum of all per cpu counters for all sites.
1741 * Using a per cpu counter is a compromise solution to concurrent access:
1742 * lu_object_put() can update the counter without locking the site and
1743 * lu_cache_shrink_count can sum the counters without locking each
1744 * ls_obj_hash bucket.
1746 static unsigned long lu_cache_shrink_count(struct shrinker
*sk
,
1747 struct shrink_control
*sc
)
1750 struct lu_site
*tmp
;
1751 unsigned long cached
= 0;
1753 if (!(sc
->gfp_mask
& __GFP_FS
))
1756 mutex_lock(&lu_sites_guard
);
1757 list_for_each_entry_safe(s
, tmp
, &lu_sites
, ls_linkage
) {
1758 cached
+= ls_stats_read(s
->ls_stats
, LU_SS_LRU_LEN
);
1760 mutex_unlock(&lu_sites_guard
);
1762 cached
= (cached
/ 100) * sysctl_vfs_cache_pressure
;
1763 CDEBUG(D_INODE
, "%ld objects cached, cache pressure %d\n",
1764 cached
, sysctl_vfs_cache_pressure
);
1769 static unsigned long lu_cache_shrink_scan(struct shrinker
*sk
,
1770 struct shrink_control
*sc
)
1773 struct lu_site
*tmp
;
1774 unsigned long remain
= sc
->nr_to_scan
, freed
= 0;
1777 if (!(sc
->gfp_mask
& __GFP_FS
))
1778 /* We must not take the lu_sites_guard lock when
1779 * __GFP_FS is *not* set because of the deadlock
1780 * possibility detailed above. Additionally,
1781 * since we cannot determine the number of
1782 * objects in the cache without taking this
1783 * lock, we're in a particularly tough spot. As
1784 * a result, we'll just lie and say our cache is
1785 * empty. This _should_ be ok, as we can't
1786 * reclaim objects when __GFP_FS is *not* set
1791 mutex_lock(&lu_sites_guard
);
1792 list_for_each_entry_safe(s
, tmp
, &lu_sites
, ls_linkage
) {
1793 freed
= lu_site_purge(&lu_shrink_env
, s
, remain
);
1796 * Move just shrunk site to the tail of site list to
1797 * assure shrinking fairness.
1799 list_move_tail(&s
->ls_linkage
, &splice
);
1801 list_splice(&splice
, lu_sites
.prev
);
1802 mutex_unlock(&lu_sites_guard
);
1804 return sc
->nr_to_scan
- remain
;
1808 * Debugging printer function using printk().
1810 static struct shrinker lu_site_shrinker
= {
1811 .count_objects
= lu_cache_shrink_count
,
1812 .scan_objects
= lu_cache_shrink_scan
,
1813 .seeks
= DEFAULT_SEEKS
,
1817 * Initialization of global lu_* data.
1819 int lu_global_init(void)
1823 CDEBUG(D_INFO
, "Lustre LU module (%p).\n", &lu_keys
);
1825 result
= lu_ref_global_init();
1829 LU_CONTEXT_KEY_INIT(&lu_global_key
);
1830 result
= lu_context_key_register(&lu_global_key
);
1835 * At this level, we don't know what tags are needed, so allocate them
1836 * conservatively. This should not be too bad, because this
1837 * environment is global.
1839 mutex_lock(&lu_sites_guard
);
1840 result
= lu_env_init(&lu_shrink_env
, LCT_SHRINKER
);
1841 mutex_unlock(&lu_sites_guard
);
1846 * seeks estimation: 3 seeks to read a record from oi, one to read
1847 * inode, one for ea. Unfortunately setting this high value results in
1848 * lu_object/inode cache consuming all the memory.
1850 register_shrinker(&lu_site_shrinker
);
1856 * Dual to lu_global_init().
1858 void lu_global_fini(void)
1860 unregister_shrinker(&lu_site_shrinker
);
1861 lu_context_key_degister(&lu_global_key
);
1864 * Tear shrinker environment down _after_ de-registering
1865 * lu_global_key, because the latter has a value in the former.
1867 mutex_lock(&lu_sites_guard
);
1868 lu_env_fini(&lu_shrink_env
);
1869 mutex_unlock(&lu_sites_guard
);
1871 lu_ref_global_fini();
1874 static __u32
ls_stats_read(struct lprocfs_stats
*stats
, int idx
)
1876 struct lprocfs_counter ret
;
1878 lprocfs_stats_collect(stats
, idx
, &ret
);
1879 if (idx
== LU_SS_LRU_LEN
)
1881 * protect against counter on cpu A being decremented
1882 * before counter is incremented on cpu B; unlikely
1884 return (__u32
)((ret
.lc_sum
> 0) ? ret
.lc_sum
: 0);
1886 return (__u32
)ret
.lc_count
;
1890 * Output site statistical counters into a buffer. Suitable for
1891 * lprocfs_rd_*()-style functions.
1893 int lu_site_stats_print(const struct lu_site
*s
, struct seq_file
*m
)
1895 struct lu_site_stats stats
;
1897 memset(&stats
, 0, sizeof(stats
));
1898 lu_site_stats_get(s
->ls_obj_hash
, &stats
, 1);
1900 seq_printf(m
, "%d/%d %d/%d %d %d %d %d %d %d %d %d\n",
1903 stats
.lss_populated
,
1904 CFS_HASH_NHLIST(s
->ls_obj_hash
),
1905 stats
.lss_max_search
,
1906 ls_stats_read(s
->ls_stats
, LU_SS_CREATED
),
1907 ls_stats_read(s
->ls_stats
, LU_SS_CACHE_HIT
),
1908 ls_stats_read(s
->ls_stats
, LU_SS_CACHE_MISS
),
1909 ls_stats_read(s
->ls_stats
, LU_SS_CACHE_RACE
),
1910 ls_stats_read(s
->ls_stats
, LU_SS_CACHE_DEATH_RACE
),
1911 ls_stats_read(s
->ls_stats
, LU_SS_LRU_PURGED
),
1912 ls_stats_read(s
->ls_stats
, LU_SS_LRU_LEN
));
1915 EXPORT_SYMBOL(lu_site_stats_print
);
1918 * Helper function to initialize a number of kmem slab caches at once.
1920 int lu_kmem_init(struct lu_kmem_descr
*caches
)
1923 struct lu_kmem_descr
*iter
= caches
;
1925 for (result
= 0; iter
->ckd_cache
!= NULL
; ++iter
) {
1926 *iter
->ckd_cache
= kmem_cache_create(iter
->ckd_name
,
1929 if (*iter
->ckd_cache
== NULL
) {
1931 /* free all previously allocated caches */
1932 lu_kmem_fini(caches
);
1938 EXPORT_SYMBOL(lu_kmem_init
);
1941 * Helper function to finalize a number of kmem slab cached at once. Dual to
1944 void lu_kmem_fini(struct lu_kmem_descr
*caches
)
1946 for (; caches
->ckd_cache
!= NULL
; ++caches
) {
1947 kmem_cache_destroy(*caches
->ckd_cache
);
1948 *caches
->ckd_cache
= NULL
;
1951 EXPORT_SYMBOL(lu_kmem_fini
);