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d7e09d03 PT |
1 | /* |
2 | * GPL HEADER START | |
3 | * | |
4 | * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER. | |
5 | * | |
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. | |
9 | * | |
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). | |
15 | * | |
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 | |
19 | * | |
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 | |
22 | * have any questions. | |
23 | * | |
24 | * GPL HEADER END | |
25 | */ | |
26 | /* | |
27 | * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved. | |
28 | * Use is subject to license terms. | |
29 | * | |
30 | * Copyright (c) 2011, 2012, Intel Corporation. | |
31 | */ | |
32 | /* | |
33 | * This file is part of Lustre, http://www.lustre.org/ | |
34 | * Lustre is a trademark of Sun Microsystems, Inc. | |
35 | * | |
36 | * lustre/obdclass/lu_object.c | |
37 | * | |
38 | * Lustre Object. | |
39 | * These are the only exported functions, they provide some generic | |
40 | * infrastructure for managing object devices | |
41 | * | |
42 | * Author: Nikita Danilov <nikita.danilov@sun.com> | |
43 | */ | |
44 | ||
45 | #define DEBUG_SUBSYSTEM S_CLASS | |
46 | ||
47 | #include <linux/libcfs/libcfs.h> | |
48 | ||
49 | # include <linux/module.h> | |
50 | ||
51 | /* hash_long() */ | |
52 | #include <linux/libcfs/libcfs_hash.h> | |
53 | #include <obd_class.h> | |
54 | #include <obd_support.h> | |
55 | #include <lustre_disk.h> | |
56 | #include <lustre_fid.h> | |
57 | #include <lu_object.h> | |
58 | #include <lu_ref.h> | |
59 | #include <linux/list.h> | |
60 | ||
61 | static void lu_object_free(const struct lu_env *env, struct lu_object *o); | |
62 | ||
63 | /** | |
64 | * Decrease reference counter on object. If last reference is freed, return | |
65 | * object to the cache, unless lu_object_is_dying(o) holds. In the latter | |
66 | * case, free object immediately. | |
67 | */ | |
68 | void lu_object_put(const struct lu_env *env, struct lu_object *o) | |
69 | { | |
70 | struct lu_site_bkt_data *bkt; | |
71 | struct lu_object_header *top; | |
72 | struct lu_site *site; | |
73 | struct lu_object *orig; | |
6ea510c1 | 74 | struct cfs_hash_bd bd; |
d7e09d03 PT |
75 | const struct lu_fid *fid; |
76 | ||
77 | top = o->lo_header; | |
78 | site = o->lo_dev->ld_site; | |
79 | orig = o; | |
80 | ||
81 | /* | |
82 | * till we have full fids-on-OST implemented anonymous objects | |
83 | * are possible in OSP. such an object isn't listed in the site | |
84 | * so we should not remove it from the site. | |
85 | */ | |
86 | fid = lu_object_fid(o); | |
87 | if (fid_is_zero(fid)) { | |
88 | LASSERT(top->loh_hash.next == NULL | |
89 | && top->loh_hash.pprev == NULL); | |
90 | LASSERT(list_empty(&top->loh_lru)); | |
91 | if (!atomic_dec_and_test(&top->loh_ref)) | |
92 | return; | |
93 | list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) { | |
94 | if (o->lo_ops->loo_object_release != NULL) | |
95 | o->lo_ops->loo_object_release(env, o); | |
96 | } | |
97 | lu_object_free(env, orig); | |
98 | return; | |
99 | } | |
100 | ||
101 | cfs_hash_bd_get(site->ls_obj_hash, &top->loh_fid, &bd); | |
102 | bkt = cfs_hash_bd_extra_get(site->ls_obj_hash, &bd); | |
103 | ||
104 | if (!cfs_hash_bd_dec_and_lock(site->ls_obj_hash, &bd, &top->loh_ref)) { | |
105 | if (lu_object_is_dying(top)) { | |
106 | ||
107 | /* | |
108 | * somebody may be waiting for this, currently only | |
109 | * used for cl_object, see cl_object_put_last(). | |
110 | */ | |
111 | wake_up_all(&bkt->lsb_marche_funebre); | |
112 | } | |
113 | return; | |
114 | } | |
115 | ||
116 | LASSERT(bkt->lsb_busy > 0); | |
117 | bkt->lsb_busy--; | |
118 | /* | |
119 | * When last reference is released, iterate over object | |
120 | * layers, and notify them that object is no longer busy. | |
121 | */ | |
122 | list_for_each_entry_reverse(o, &top->loh_layers, lo_linkage) { | |
123 | if (o->lo_ops->loo_object_release != NULL) | |
124 | o->lo_ops->loo_object_release(env, o); | |
125 | } | |
126 | ||
127 | if (!lu_object_is_dying(top)) { | |
128 | LASSERT(list_empty(&top->loh_lru)); | |
129 | list_add_tail(&top->loh_lru, &bkt->lsb_lru); | |
130 | cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1); | |
131 | return; | |
132 | } | |
133 | ||
134 | /* | |
135 | * If object is dying (will not be cached), removed it | |
136 | * from hash table and LRU. | |
137 | * | |
138 | * This is done with hash table and LRU lists locked. As the only | |
139 | * way to acquire first reference to previously unreferenced | |
140 | * object is through hash-table lookup (lu_object_find()), | |
141 | * or LRU scanning (lu_site_purge()), that are done under hash-table | |
142 | * and LRU lock, no race with concurrent object lookup is possible | |
143 | * and we can safely destroy object below. | |
144 | */ | |
145 | if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) | |
146 | cfs_hash_bd_del_locked(site->ls_obj_hash, &bd, &top->loh_hash); | |
147 | cfs_hash_bd_unlock(site->ls_obj_hash, &bd, 1); | |
148 | /* | |
149 | * Object was already removed from hash and lru above, can | |
150 | * kill it. | |
151 | */ | |
152 | lu_object_free(env, orig); | |
153 | } | |
154 | EXPORT_SYMBOL(lu_object_put); | |
155 | ||
156 | /** | |
157 | * Put object and don't keep in cache. This is temporary solution for | |
158 | * multi-site objects when its layering is not constant. | |
159 | */ | |
160 | void lu_object_put_nocache(const struct lu_env *env, struct lu_object *o) | |
161 | { | |
162 | set_bit(LU_OBJECT_HEARD_BANSHEE, &o->lo_header->loh_flags); | |
163 | return lu_object_put(env, o); | |
164 | } | |
165 | EXPORT_SYMBOL(lu_object_put_nocache); | |
166 | ||
167 | /** | |
168 | * Kill the object and take it out of LRU cache. | |
169 | * Currently used by client code for layout change. | |
170 | */ | |
171 | void lu_object_unhash(const struct lu_env *env, struct lu_object *o) | |
172 | { | |
173 | struct lu_object_header *top; | |
174 | ||
175 | top = o->lo_header; | |
176 | set_bit(LU_OBJECT_HEARD_BANSHEE, &top->loh_flags); | |
177 | if (!test_and_set_bit(LU_OBJECT_UNHASHED, &top->loh_flags)) { | |
6da6eabe | 178 | struct cfs_hash *obj_hash = o->lo_dev->ld_site->ls_obj_hash; |
6ea510c1 | 179 | struct cfs_hash_bd bd; |
d7e09d03 PT |
180 | |
181 | cfs_hash_bd_get_and_lock(obj_hash, &top->loh_fid, &bd, 1); | |
182 | list_del_init(&top->loh_lru); | |
183 | cfs_hash_bd_del_locked(obj_hash, &bd, &top->loh_hash); | |
184 | cfs_hash_bd_unlock(obj_hash, &bd, 1); | |
185 | } | |
186 | } | |
187 | EXPORT_SYMBOL(lu_object_unhash); | |
188 | ||
189 | /** | |
190 | * Allocate new object. | |
191 | * | |
192 | * This follows object creation protocol, described in the comment within | |
193 | * struct lu_device_operations definition. | |
194 | */ | |
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) | |
199 | { | |
200 | struct lu_object *scan; | |
201 | struct lu_object *top; | |
202 | struct list_head *layers; | |
7cd875d2 JH |
203 | unsigned int init_mask = 0; |
204 | unsigned int init_flag; | |
d7e09d03 PT |
205 | int clean; |
206 | int result; | |
d7e09d03 PT |
207 | |
208 | /* | |
209 | * Create top-level object slice. This will also create | |
210 | * lu_object_header. | |
211 | */ | |
212 | top = dev->ld_ops->ldo_object_alloc(env, NULL, dev); | |
213 | if (top == NULL) | |
0a3bdb00 | 214 | return ERR_PTR(-ENOMEM); |
d7e09d03 | 215 | if (IS_ERR(top)) |
0a3bdb00 | 216 | return top; |
d7e09d03 PT |
217 | /* |
218 | * This is the only place where object fid is assigned. It's constant | |
219 | * after this point. | |
220 | */ | |
221 | top->lo_header->loh_fid = *f; | |
222 | layers = &top->lo_header->loh_layers; | |
7cd875d2 | 223 | |
d7e09d03 PT |
224 | do { |
225 | /* | |
226 | * Call ->loo_object_init() repeatedly, until no more new | |
227 | * object slices are created. | |
228 | */ | |
229 | clean = 1; | |
7cd875d2 | 230 | init_flag = 1; |
d7e09d03 | 231 | list_for_each_entry(scan, layers, lo_linkage) { |
7cd875d2 JH |
232 | if (init_mask & init_flag) |
233 | goto next; | |
d7e09d03 PT |
234 | clean = 0; |
235 | scan->lo_header = top->lo_header; | |
236 | result = scan->lo_ops->loo_object_init(env, scan, conf); | |
237 | if (result != 0) { | |
238 | lu_object_free(env, top); | |
0a3bdb00 | 239 | return ERR_PTR(result); |
d7e09d03 | 240 | } |
7cd875d2 JH |
241 | init_mask |= init_flag; |
242 | next: | |
243 | init_flag <<= 1; | |
d7e09d03 PT |
244 | } |
245 | } while (!clean); | |
246 | ||
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); | |
250 | if (result != 0) { | |
251 | lu_object_free(env, top); | |
0a3bdb00 | 252 | return ERR_PTR(result); |
d7e09d03 PT |
253 | } |
254 | } | |
255 | } | |
256 | ||
257 | lprocfs_counter_incr(dev->ld_site->ls_stats, LU_SS_CREATED); | |
0a3bdb00 | 258 | return top; |
d7e09d03 PT |
259 | } |
260 | ||
261 | /** | |
262 | * Free an object. | |
263 | */ | |
264 | static void lu_object_free(const struct lu_env *env, struct lu_object *o) | |
265 | { | |
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; | |
271 | ||
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); | |
275 | /* | |
276 | * First call ->loo_object_delete() method to release all resources. | |
277 | */ | |
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); | |
281 | } | |
282 | ||
283 | /* | |
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 | |
287 | * top-level slice. | |
288 | */ | |
289 | INIT_LIST_HEAD(&splice); | |
290 | list_splice_init(layers, &splice); | |
291 | while (!list_empty(&splice)) { | |
292 | /* | |
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. | |
296 | */ | |
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); | |
301 | } | |
302 | ||
303 | if (waitqueue_active(&bkt->lsb_marche_funebre)) | |
304 | wake_up_all(&bkt->lsb_marche_funebre); | |
305 | } | |
306 | ||
307 | /** | |
308 | * Free \a nr objects from the cold end of the site LRU list. | |
309 | */ | |
310 | int lu_site_purge(const struct lu_env *env, struct lu_site *s, int nr) | |
311 | { | |
312 | struct lu_object_header *h; | |
313 | struct lu_object_header *temp; | |
314 | struct lu_site_bkt_data *bkt; | |
6ea510c1 LN |
315 | struct cfs_hash_bd bd; |
316 | struct cfs_hash_bd bd2; | |
d7e09d03 PT |
317 | struct list_head dispose; |
318 | int did_sth; | |
319 | int start; | |
320 | int count; | |
321 | int bnr; | |
322 | int i; | |
323 | ||
324 | if (OBD_FAIL_CHECK(OBD_FAIL_OBD_NO_LRU)) | |
0a3bdb00 | 325 | return 0; |
d7e09d03 PT |
326 | |
327 | INIT_LIST_HEAD(&dispose); | |
328 | /* | |
329 | * Under LRU list lock, scan LRU list and move unreferenced objects to | |
330 | * the dispose list, removing them from LRU and hash table. | |
331 | */ | |
332 | start = s->ls_purge_start; | |
333 | bnr = (nr == ~0) ? -1 : nr / CFS_HASH_NBKT(s->ls_obj_hash) + 1; | |
334 | again: | |
335 | did_sth = 0; | |
336 | cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) { | |
337 | if (i < start) | |
338 | continue; | |
339 | count = bnr; | |
340 | cfs_hash_bd_lock(s->ls_obj_hash, &bd, 1); | |
341 | bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd); | |
342 | ||
343 | list_for_each_entry_safe(h, temp, &bkt->lsb_lru, loh_lru) { | |
344 | LASSERT(atomic_read(&h->loh_ref) == 0); | |
345 | ||
346 | cfs_hash_bd_get(s->ls_obj_hash, &h->loh_fid, &bd2); | |
347 | LASSERT(bd.bd_bucket == bd2.bd_bucket); | |
348 | ||
349 | cfs_hash_bd_del_locked(s->ls_obj_hash, | |
350 | &bd2, &h->loh_hash); | |
351 | list_move(&h->loh_lru, &dispose); | |
352 | if (did_sth == 0) | |
353 | did_sth = 1; | |
354 | ||
355 | if (nr != ~0 && --nr == 0) | |
356 | break; | |
357 | ||
358 | if (count > 0 && --count == 0) | |
359 | break; | |
360 | ||
361 | } | |
362 | cfs_hash_bd_unlock(s->ls_obj_hash, &bd, 1); | |
363 | cond_resched(); | |
364 | /* | |
365 | * Free everything on the dispose list. This is safe against | |
366 | * races due to the reasons described in lu_object_put(). | |
367 | */ | |
368 | while (!list_empty(&dispose)) { | |
369 | h = container_of0(dispose.next, | |
370 | struct lu_object_header, loh_lru); | |
371 | list_del_init(&h->loh_lru); | |
372 | lu_object_free(env, lu_object_top(h)); | |
373 | lprocfs_counter_incr(s->ls_stats, LU_SS_LRU_PURGED); | |
374 | } | |
375 | ||
376 | if (nr == 0) | |
377 | break; | |
378 | } | |
379 | ||
380 | if (nr != 0 && did_sth && start != 0) { | |
381 | start = 0; /* restart from the first bucket */ | |
382 | goto again; | |
383 | } | |
384 | /* race on s->ls_purge_start, but nobody cares */ | |
385 | s->ls_purge_start = i % CFS_HASH_NBKT(s->ls_obj_hash); | |
386 | ||
387 | return nr; | |
388 | } | |
389 | EXPORT_SYMBOL(lu_site_purge); | |
390 | ||
391 | /* | |
392 | * Object printing. | |
393 | * | |
394 | * Code below has to jump through certain loops to output object description | |
395 | * into libcfs_debug_msg-based log. The problem is that lu_object_print() | |
396 | * composes object description from strings that are parts of _lines_ of | |
397 | * output (i.e., strings that are not terminated by newline). This doesn't fit | |
398 | * very well into libcfs_debug_msg() interface that assumes that each message | |
399 | * supplied to it is a self-contained output line. | |
400 | * | |
401 | * To work around this, strings are collected in a temporary buffer | |
402 | * (implemented as a value of lu_cdebug_key key), until terminating newline | |
403 | * character is detected. | |
404 | * | |
405 | */ | |
406 | ||
407 | enum { | |
408 | /** | |
409 | * Maximal line size. | |
410 | * | |
411 | * XXX overflow is not handled correctly. | |
412 | */ | |
413 | LU_CDEBUG_LINE = 512 | |
414 | }; | |
415 | ||
416 | struct lu_cdebug_data { | |
417 | /** | |
418 | * Temporary buffer. | |
419 | */ | |
420 | char lck_area[LU_CDEBUG_LINE]; | |
421 | }; | |
422 | ||
423 | /* context key constructor/destructor: lu_global_key_init, lu_global_key_fini */ | |
424 | LU_KEY_INIT_FINI(lu_global, struct lu_cdebug_data); | |
425 | ||
426 | /** | |
427 | * Key, holding temporary buffer. This key is registered very early by | |
428 | * lu_global_init(). | |
429 | */ | |
430 | struct lu_context_key lu_global_key = { | |
431 | .lct_tags = LCT_MD_THREAD | LCT_DT_THREAD | | |
aa4e3c8a | 432 | LCT_MG_THREAD | LCT_CL_THREAD | LCT_LOCAL, |
d7e09d03 PT |
433 | .lct_init = lu_global_key_init, |
434 | .lct_fini = lu_global_key_fini | |
435 | }; | |
436 | ||
437 | /** | |
438 | * Printer function emitting messages through libcfs_debug_msg(). | |
439 | */ | |
440 | int lu_cdebug_printer(const struct lu_env *env, | |
441 | void *cookie, const char *format, ...) | |
442 | { | |
443 | struct libcfs_debug_msg_data *msgdata = cookie; | |
444 | struct lu_cdebug_data *key; | |
445 | int used; | |
446 | int complete; | |
447 | va_list args; | |
448 | ||
449 | va_start(args, format); | |
450 | ||
451 | key = lu_context_key_get(&env->le_ctx, &lu_global_key); | |
452 | LASSERT(key != NULL); | |
453 | ||
454 | used = strlen(key->lck_area); | |
455 | complete = format[strlen(format) - 1] == '\n'; | |
456 | /* | |
457 | * Append new chunk to the buffer. | |
458 | */ | |
459 | vsnprintf(key->lck_area + used, | |
460 | ARRAY_SIZE(key->lck_area) - used, format, args); | |
461 | if (complete) { | |
462 | if (cfs_cdebug_show(msgdata->msg_mask, msgdata->msg_subsys)) | |
463 | libcfs_debug_msg(msgdata, "%s", key->lck_area); | |
464 | key->lck_area[0] = 0; | |
465 | } | |
466 | va_end(args); | |
467 | return 0; | |
468 | } | |
469 | EXPORT_SYMBOL(lu_cdebug_printer); | |
470 | ||
471 | /** | |
472 | * Print object header. | |
473 | */ | |
474 | void lu_object_header_print(const struct lu_env *env, void *cookie, | |
475 | lu_printer_t printer, | |
476 | const struct lu_object_header *hdr) | |
477 | { | |
478 | (*printer)(env, cookie, "header@%p[%#lx, %d, "DFID"%s%s%s]", | |
479 | hdr, hdr->loh_flags, atomic_read(&hdr->loh_ref), | |
480 | PFID(&hdr->loh_fid), | |
481 | hlist_unhashed(&hdr->loh_hash) ? "" : " hash", | |
482 | list_empty((struct list_head *)&hdr->loh_lru) ? \ | |
483 | "" : " lru", | |
484 | hdr->loh_attr & LOHA_EXISTS ? " exist":""); | |
485 | } | |
486 | EXPORT_SYMBOL(lu_object_header_print); | |
487 | ||
488 | /** | |
489 | * Print human readable representation of the \a o to the \a printer. | |
490 | */ | |
491 | void lu_object_print(const struct lu_env *env, void *cookie, | |
492 | lu_printer_t printer, const struct lu_object *o) | |
493 | { | |
494 | static const char ruler[] = "........................................"; | |
495 | struct lu_object_header *top; | |
7cd875d2 | 496 | int depth = 4; |
d7e09d03 PT |
497 | |
498 | top = o->lo_header; | |
499 | lu_object_header_print(env, cookie, printer, top); | |
7cd875d2 | 500 | (*printer)(env, cookie, "{\n"); |
d7e09d03 | 501 | |
7cd875d2 | 502 | list_for_each_entry(o, &top->loh_layers, lo_linkage) { |
d7e09d03 PT |
503 | /* |
504 | * print `.' \a depth times followed by type name and address | |
505 | */ | |
506 | (*printer)(env, cookie, "%*.*s%s@%p", depth, depth, ruler, | |
507 | o->lo_dev->ld_type->ldt_name, o); | |
7cd875d2 | 508 | |
d7e09d03 | 509 | if (o->lo_ops->loo_object_print != NULL) |
7cd875d2 JH |
510 | (*o->lo_ops->loo_object_print)(env, cookie, printer, o); |
511 | ||
d7e09d03 PT |
512 | (*printer)(env, cookie, "\n"); |
513 | } | |
7cd875d2 | 514 | |
d7e09d03 PT |
515 | (*printer)(env, cookie, "} header@%p\n", top); |
516 | } | |
517 | EXPORT_SYMBOL(lu_object_print); | |
518 | ||
519 | /** | |
520 | * Check object consistency. | |
521 | */ | |
522 | int lu_object_invariant(const struct lu_object *o) | |
523 | { | |
524 | struct lu_object_header *top; | |
525 | ||
526 | top = o->lo_header; | |
527 | list_for_each_entry(o, &top->loh_layers, lo_linkage) { | |
528 | if (o->lo_ops->loo_object_invariant != NULL && | |
529 | !o->lo_ops->loo_object_invariant(o)) | |
530 | return 0; | |
531 | } | |
532 | return 1; | |
533 | } | |
534 | EXPORT_SYMBOL(lu_object_invariant); | |
535 | ||
536 | static struct lu_object *htable_lookup(struct lu_site *s, | |
6ea510c1 | 537 | struct cfs_hash_bd *bd, |
d7e09d03 PT |
538 | const struct lu_fid *f, |
539 | wait_queue_t *waiter, | |
540 | __u64 *version) | |
541 | { | |
542 | struct lu_site_bkt_data *bkt; | |
543 | struct lu_object_header *h; | |
544 | struct hlist_node *hnode; | |
545 | __u64 ver = cfs_hash_bd_version_get(bd); | |
546 | ||
547 | if (*version == ver) | |
70b749d4 | 548 | return ERR_PTR(-ENOENT); |
d7e09d03 PT |
549 | |
550 | *version = ver; | |
551 | bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, bd); | |
552 | /* cfs_hash_bd_peek_locked is a somehow "internal" function | |
553 | * of cfs_hash, it doesn't add refcount on object. */ | |
554 | hnode = cfs_hash_bd_peek_locked(s->ls_obj_hash, bd, (void *)f); | |
555 | if (hnode == NULL) { | |
556 | lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_MISS); | |
70b749d4 | 557 | return ERR_PTR(-ENOENT); |
d7e09d03 PT |
558 | } |
559 | ||
560 | h = container_of0(hnode, struct lu_object_header, loh_hash); | |
561 | if (likely(!lu_object_is_dying(h))) { | |
562 | cfs_hash_get(s->ls_obj_hash, hnode); | |
563 | lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_HIT); | |
564 | list_del_init(&h->loh_lru); | |
565 | return lu_object_top(h); | |
566 | } | |
567 | ||
568 | /* | |
569 | * Lookup found an object being destroyed this object cannot be | |
570 | * returned (to assure that references to dying objects are eventually | |
571 | * drained), and moreover, lookup has to wait until object is freed. | |
572 | */ | |
573 | ||
9e795d35 | 574 | init_waitqueue_entry(waiter, current); |
d7e09d03 PT |
575 | add_wait_queue(&bkt->lsb_marche_funebre, waiter); |
576 | set_current_state(TASK_UNINTERRUPTIBLE); | |
577 | lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_DEATH_RACE); | |
578 | return ERR_PTR(-EAGAIN); | |
579 | } | |
580 | ||
581 | /** | |
582 | * Search cache for an object with the fid \a f. If such object is found, | |
583 | * return it. Otherwise, create new object, insert it into cache and return | |
584 | * it. In any case, additional reference is acquired on the returned object. | |
585 | */ | |
586 | struct lu_object *lu_object_find(const struct lu_env *env, | |
587 | struct lu_device *dev, const struct lu_fid *f, | |
588 | const struct lu_object_conf *conf) | |
589 | { | |
590 | return lu_object_find_at(env, dev->ld_site->ls_top_dev, f, conf); | |
591 | } | |
592 | EXPORT_SYMBOL(lu_object_find); | |
593 | ||
594 | static struct lu_object *lu_object_new(const struct lu_env *env, | |
595 | struct lu_device *dev, | |
596 | const struct lu_fid *f, | |
597 | const struct lu_object_conf *conf) | |
598 | { | |
599 | struct lu_object *o; | |
6da6eabe | 600 | struct cfs_hash *hs; |
6ea510c1 | 601 | struct cfs_hash_bd bd; |
d7e09d03 PT |
602 | struct lu_site_bkt_data *bkt; |
603 | ||
604 | o = lu_object_alloc(env, dev, f, conf); | |
605 | if (unlikely(IS_ERR(o))) | |
606 | return o; | |
607 | ||
608 | hs = dev->ld_site->ls_obj_hash; | |
609 | cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1); | |
610 | bkt = cfs_hash_bd_extra_get(hs, &bd); | |
611 | cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash); | |
612 | bkt->lsb_busy++; | |
613 | cfs_hash_bd_unlock(hs, &bd, 1); | |
614 | return o; | |
615 | } | |
616 | ||
617 | /** | |
618 | * Core logic of lu_object_find*() functions. | |
619 | */ | |
620 | static struct lu_object *lu_object_find_try(const struct lu_env *env, | |
621 | struct lu_device *dev, | |
622 | const struct lu_fid *f, | |
623 | const struct lu_object_conf *conf, | |
624 | wait_queue_t *waiter) | |
625 | { | |
626 | struct lu_object *o; | |
627 | struct lu_object *shadow; | |
628 | struct lu_site *s; | |
6da6eabe | 629 | struct cfs_hash *hs; |
6ea510c1 | 630 | struct cfs_hash_bd bd; |
d7e09d03 PT |
631 | __u64 version = 0; |
632 | ||
633 | /* | |
634 | * This uses standard index maintenance protocol: | |
635 | * | |
636 | * - search index under lock, and return object if found; | |
637 | * - otherwise, unlock index, allocate new object; | |
638 | * - lock index and search again; | |
639 | * - if nothing is found (usual case), insert newly created | |
640 | * object into index; | |
641 | * - otherwise (race: other thread inserted object), free | |
642 | * object just allocated. | |
643 | * - unlock index; | |
644 | * - return object. | |
645 | * | |
646 | * For "LOC_F_NEW" case, we are sure the object is new established. | |
647 | * It is unnecessary to perform lookup-alloc-lookup-insert, instead, | |
648 | * just alloc and insert directly. | |
649 | * | |
650 | * If dying object is found during index search, add @waiter to the | |
651 | * site wait-queue and return ERR_PTR(-EAGAIN). | |
652 | */ | |
653 | if (conf != NULL && conf->loc_flags & LOC_F_NEW) | |
654 | return lu_object_new(env, dev, f, conf); | |
655 | ||
656 | s = dev->ld_site; | |
657 | hs = s->ls_obj_hash; | |
658 | cfs_hash_bd_get_and_lock(hs, (void *)f, &bd, 1); | |
659 | o = htable_lookup(s, &bd, f, waiter, &version); | |
660 | cfs_hash_bd_unlock(hs, &bd, 1); | |
70b749d4 | 661 | if (!IS_ERR(o) || PTR_ERR(o) != -ENOENT) |
d7e09d03 PT |
662 | return o; |
663 | ||
664 | /* | |
665 | * Allocate new object. This may result in rather complicated | |
666 | * operations, including fld queries, inode loading, etc. | |
667 | */ | |
668 | o = lu_object_alloc(env, dev, f, conf); | |
669 | if (unlikely(IS_ERR(o))) | |
670 | return o; | |
671 | ||
672 | LASSERT(lu_fid_eq(lu_object_fid(o), f)); | |
673 | ||
674 | cfs_hash_bd_lock(hs, &bd, 1); | |
675 | ||
676 | shadow = htable_lookup(s, &bd, f, waiter, &version); | |
70b749d4 | 677 | if (likely(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT)) { |
d7e09d03 PT |
678 | struct lu_site_bkt_data *bkt; |
679 | ||
680 | bkt = cfs_hash_bd_extra_get(hs, &bd); | |
681 | cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash); | |
682 | bkt->lsb_busy++; | |
683 | cfs_hash_bd_unlock(hs, &bd, 1); | |
684 | return o; | |
685 | } | |
686 | ||
687 | lprocfs_counter_incr(s->ls_stats, LU_SS_CACHE_RACE); | |
688 | cfs_hash_bd_unlock(hs, &bd, 1); | |
689 | lu_object_free(env, o); | |
690 | return shadow; | |
691 | } | |
692 | ||
693 | /** | |
694 | * Much like lu_object_find(), but top level device of object is specifically | |
695 | * \a dev rather than top level device of the site. This interface allows | |
696 | * objects of different "stacking" to be created within the same site. | |
697 | */ | |
698 | struct lu_object *lu_object_find_at(const struct lu_env *env, | |
699 | struct lu_device *dev, | |
700 | const struct lu_fid *f, | |
701 | const struct lu_object_conf *conf) | |
702 | { | |
703 | struct lu_site_bkt_data *bkt; | |
704 | struct lu_object *obj; | |
705 | wait_queue_t wait; | |
706 | ||
707 | while (1) { | |
708 | obj = lu_object_find_try(env, dev, f, conf, &wait); | |
709 | if (obj != ERR_PTR(-EAGAIN)) | |
710 | return obj; | |
711 | /* | |
712 | * lu_object_find_try() already added waiter into the | |
713 | * wait queue. | |
714 | */ | |
715 | waitq_wait(&wait, TASK_UNINTERRUPTIBLE); | |
716 | bkt = lu_site_bkt_from_fid(dev->ld_site, (void *)f); | |
717 | remove_wait_queue(&bkt->lsb_marche_funebre, &wait); | |
718 | } | |
719 | } | |
720 | EXPORT_SYMBOL(lu_object_find_at); | |
721 | ||
722 | /** | |
723 | * Find object with given fid, and return its slice belonging to given device. | |
724 | */ | |
725 | struct lu_object *lu_object_find_slice(const struct lu_env *env, | |
726 | struct lu_device *dev, | |
727 | const struct lu_fid *f, | |
728 | const struct lu_object_conf *conf) | |
729 | { | |
730 | struct lu_object *top; | |
731 | struct lu_object *obj; | |
732 | ||
733 | top = lu_object_find(env, dev, f, conf); | |
734 | if (!IS_ERR(top)) { | |
735 | obj = lu_object_locate(top->lo_header, dev->ld_type); | |
736 | if (obj == NULL) | |
737 | lu_object_put(env, top); | |
738 | } else | |
739 | obj = top; | |
740 | return obj; | |
741 | } | |
742 | EXPORT_SYMBOL(lu_object_find_slice); | |
743 | ||
744 | /** | |
745 | * Global list of all device types. | |
746 | */ | |
747 | static LIST_HEAD(lu_device_types); | |
748 | ||
749 | int lu_device_type_init(struct lu_device_type *ldt) | |
750 | { | |
751 | int result = 0; | |
752 | ||
753 | INIT_LIST_HEAD(&ldt->ldt_linkage); | |
754 | if (ldt->ldt_ops->ldto_init) | |
755 | result = ldt->ldt_ops->ldto_init(ldt); | |
756 | if (result == 0) | |
757 | list_add(&ldt->ldt_linkage, &lu_device_types); | |
758 | return result; | |
759 | } | |
760 | EXPORT_SYMBOL(lu_device_type_init); | |
761 | ||
762 | void lu_device_type_fini(struct lu_device_type *ldt) | |
763 | { | |
764 | list_del_init(&ldt->ldt_linkage); | |
765 | if (ldt->ldt_ops->ldto_fini) | |
766 | ldt->ldt_ops->ldto_fini(ldt); | |
767 | } | |
768 | EXPORT_SYMBOL(lu_device_type_fini); | |
769 | ||
770 | void lu_types_stop(void) | |
771 | { | |
772 | struct lu_device_type *ldt; | |
773 | ||
774 | list_for_each_entry(ldt, &lu_device_types, ldt_linkage) { | |
775 | if (ldt->ldt_device_nr == 0 && ldt->ldt_ops->ldto_stop) | |
776 | ldt->ldt_ops->ldto_stop(ldt); | |
777 | } | |
778 | } | |
779 | EXPORT_SYMBOL(lu_types_stop); | |
780 | ||
781 | /** | |
782 | * Global list of all sites on this node | |
783 | */ | |
784 | static LIST_HEAD(lu_sites); | |
785 | static DEFINE_MUTEX(lu_sites_guard); | |
786 | ||
787 | /** | |
788 | * Global environment used by site shrinker. | |
789 | */ | |
790 | static struct lu_env lu_shrink_env; | |
791 | ||
792 | struct lu_site_print_arg { | |
793 | struct lu_env *lsp_env; | |
794 | void *lsp_cookie; | |
795 | lu_printer_t lsp_printer; | |
796 | }; | |
797 | ||
798 | static int | |
6da6eabe | 799 | lu_site_obj_print(struct cfs_hash *hs, struct cfs_hash_bd *bd, |
d7e09d03 PT |
800 | struct hlist_node *hnode, void *data) |
801 | { | |
802 | struct lu_site_print_arg *arg = (struct lu_site_print_arg *)data; | |
803 | struct lu_object_header *h; | |
804 | ||
805 | h = hlist_entry(hnode, struct lu_object_header, loh_hash); | |
806 | if (!list_empty(&h->loh_layers)) { | |
807 | const struct lu_object *o; | |
808 | ||
809 | o = lu_object_top(h); | |
810 | lu_object_print(arg->lsp_env, arg->lsp_cookie, | |
811 | arg->lsp_printer, o); | |
812 | } else { | |
813 | lu_object_header_print(arg->lsp_env, arg->lsp_cookie, | |
814 | arg->lsp_printer, h); | |
815 | } | |
816 | return 0; | |
817 | } | |
818 | ||
819 | /** | |
820 | * Print all objects in \a s. | |
821 | */ | |
822 | void lu_site_print(const struct lu_env *env, struct lu_site *s, void *cookie, | |
823 | lu_printer_t printer) | |
824 | { | |
825 | struct lu_site_print_arg arg = { | |
826 | .lsp_env = (struct lu_env *)env, | |
827 | .lsp_cookie = cookie, | |
828 | .lsp_printer = printer, | |
829 | }; | |
830 | ||
831 | cfs_hash_for_each(s->ls_obj_hash, lu_site_obj_print, &arg); | |
832 | } | |
833 | EXPORT_SYMBOL(lu_site_print); | |
834 | ||
835 | enum { | |
836 | LU_CACHE_PERCENT_MAX = 50, | |
837 | LU_CACHE_PERCENT_DEFAULT = 20 | |
838 | }; | |
839 | ||
840 | static unsigned int lu_cache_percent = LU_CACHE_PERCENT_DEFAULT; | |
8cc7b4b9 PT |
841 | module_param(lu_cache_percent, int, 0644); |
842 | MODULE_PARM_DESC(lu_cache_percent, "Percentage of memory to be used as lu_object cache"); | |
d7e09d03 PT |
843 | |
844 | /** | |
845 | * Return desired hash table order. | |
846 | */ | |
847 | static int lu_htable_order(void) | |
848 | { | |
849 | unsigned long cache_size; | |
850 | int bits; | |
851 | ||
852 | /* | |
853 | * Calculate hash table size, assuming that we want reasonable | |
854 | * performance when 20% of total memory is occupied by cache of | |
855 | * lu_objects. | |
856 | * | |
857 | * Size of lu_object is (arbitrary) taken as 1K (together with inode). | |
858 | */ | |
4f6cc9ab | 859 | cache_size = totalram_pages; |
d7e09d03 PT |
860 | |
861 | #if BITS_PER_LONG == 32 | |
862 | /* limit hashtable size for lowmem systems to low RAM */ | |
863 | if (cache_size > 1 << (30 - PAGE_CACHE_SHIFT)) | |
864 | cache_size = 1 << (30 - PAGE_CACHE_SHIFT) * 3 / 4; | |
865 | #endif | |
866 | ||
867 | /* clear off unreasonable cache setting. */ | |
868 | if (lu_cache_percent == 0 || lu_cache_percent > LU_CACHE_PERCENT_MAX) { | |
869 | CWARN("obdclass: invalid lu_cache_percent: %u, it must be in" | |
870 | " the range of (0, %u]. Will use default value: %u.\n", | |
871 | lu_cache_percent, LU_CACHE_PERCENT_MAX, | |
872 | LU_CACHE_PERCENT_DEFAULT); | |
873 | ||
874 | lu_cache_percent = LU_CACHE_PERCENT_DEFAULT; | |
875 | } | |
876 | cache_size = cache_size / 100 * lu_cache_percent * | |
877 | (PAGE_CACHE_SIZE / 1024); | |
878 | ||
879 | for (bits = 1; (1 << bits) < cache_size; ++bits) { | |
880 | ; | |
881 | } | |
882 | return bits; | |
883 | } | |
884 | ||
6da6eabe | 885 | static unsigned lu_obj_hop_hash(struct cfs_hash *hs, |
d7e09d03 PT |
886 | const void *key, unsigned mask) |
887 | { | |
888 | struct lu_fid *fid = (struct lu_fid *)key; | |
889 | __u32 hash; | |
890 | ||
891 | hash = fid_flatten32(fid); | |
892 | hash += (hash >> 4) + (hash << 12); /* mixing oid and seq */ | |
72c0824a | 893 | hash = hash_long(hash, hs->hs_bkt_bits); |
d7e09d03 PT |
894 | |
895 | /* give me another random factor */ | |
72c0824a | 896 | hash -= hash_long((unsigned long)hs, fid_oid(fid) % 11 + 3); |
d7e09d03 PT |
897 | |
898 | hash <<= hs->hs_cur_bits - hs->hs_bkt_bits; | |
899 | hash |= (fid_seq(fid) + fid_oid(fid)) & (CFS_HASH_NBKT(hs) - 1); | |
900 | ||
901 | return hash & mask; | |
902 | } | |
903 | ||
904 | static void *lu_obj_hop_object(struct hlist_node *hnode) | |
905 | { | |
906 | return hlist_entry(hnode, struct lu_object_header, loh_hash); | |
907 | } | |
908 | ||
909 | static void *lu_obj_hop_key(struct hlist_node *hnode) | |
910 | { | |
911 | struct lu_object_header *h; | |
912 | ||
913 | h = hlist_entry(hnode, struct lu_object_header, loh_hash); | |
914 | return &h->loh_fid; | |
915 | } | |
916 | ||
917 | static int lu_obj_hop_keycmp(const void *key, struct hlist_node *hnode) | |
918 | { | |
919 | struct lu_object_header *h; | |
920 | ||
921 | h = hlist_entry(hnode, struct lu_object_header, loh_hash); | |
922 | return lu_fid_eq(&h->loh_fid, (struct lu_fid *)key); | |
923 | } | |
924 | ||
6da6eabe | 925 | static void lu_obj_hop_get(struct cfs_hash *hs, struct hlist_node *hnode) |
d7e09d03 PT |
926 | { |
927 | struct lu_object_header *h; | |
928 | ||
929 | h = hlist_entry(hnode, struct lu_object_header, loh_hash); | |
930 | if (atomic_add_return(1, &h->loh_ref) == 1) { | |
931 | struct lu_site_bkt_data *bkt; | |
6ea510c1 | 932 | struct cfs_hash_bd bd; |
d7e09d03 PT |
933 | |
934 | cfs_hash_bd_get(hs, &h->loh_fid, &bd); | |
935 | bkt = cfs_hash_bd_extra_get(hs, &bd); | |
936 | bkt->lsb_busy++; | |
937 | } | |
938 | } | |
939 | ||
6da6eabe | 940 | static void lu_obj_hop_put_locked(struct cfs_hash *hs, struct hlist_node *hnode) |
d7e09d03 PT |
941 | { |
942 | LBUG(); /* we should never called it */ | |
943 | } | |
944 | ||
945 | cfs_hash_ops_t lu_site_hash_ops = { | |
946 | .hs_hash = lu_obj_hop_hash, | |
947 | .hs_key = lu_obj_hop_key, | |
948 | .hs_keycmp = lu_obj_hop_keycmp, | |
949 | .hs_object = lu_obj_hop_object, | |
950 | .hs_get = lu_obj_hop_get, | |
951 | .hs_put_locked = lu_obj_hop_put_locked, | |
952 | }; | |
953 | ||
954 | void lu_dev_add_linkage(struct lu_site *s, struct lu_device *d) | |
955 | { | |
956 | spin_lock(&s->ls_ld_lock); | |
957 | if (list_empty(&d->ld_linkage)) | |
958 | list_add(&d->ld_linkage, &s->ls_ld_linkage); | |
959 | spin_unlock(&s->ls_ld_lock); | |
960 | } | |
961 | EXPORT_SYMBOL(lu_dev_add_linkage); | |
962 | ||
963 | void lu_dev_del_linkage(struct lu_site *s, struct lu_device *d) | |
964 | { | |
965 | spin_lock(&s->ls_ld_lock); | |
966 | list_del_init(&d->ld_linkage); | |
967 | spin_unlock(&s->ls_ld_lock); | |
968 | } | |
969 | EXPORT_SYMBOL(lu_dev_del_linkage); | |
970 | ||
971 | /** | |
972 | * Initialize site \a s, with \a d as the top level device. | |
973 | */ | |
974 | #define LU_SITE_BITS_MIN 12 | |
975 | #define LU_SITE_BITS_MAX 24 | |
976 | /** | |
977 | * total 256 buckets, we don't want too many buckets because: | |
978 | * - consume too much memory | |
979 | * - avoid unbalanced LRU list | |
980 | */ | |
981 | #define LU_SITE_BKT_BITS 8 | |
982 | ||
983 | int lu_site_init(struct lu_site *s, struct lu_device *top) | |
984 | { | |
985 | struct lu_site_bkt_data *bkt; | |
6ea510c1 | 986 | struct cfs_hash_bd bd; |
d7e09d03 PT |
987 | char name[16]; |
988 | int bits; | |
989 | int i; | |
d7e09d03 | 990 | |
ec83e611 | 991 | memset(s, 0, sizeof(*s)); |
d7e09d03 PT |
992 | bits = lu_htable_order(); |
993 | snprintf(name, 16, "lu_site_%s", top->ld_type->ldt_name); | |
994 | for (bits = min(max(LU_SITE_BITS_MIN, bits), LU_SITE_BITS_MAX); | |
995 | bits >= LU_SITE_BITS_MIN; bits--) { | |
996 | s->ls_obj_hash = cfs_hash_create(name, bits, bits, | |
997 | bits - LU_SITE_BKT_BITS, | |
998 | sizeof(*bkt), 0, 0, | |
999 | &lu_site_hash_ops, | |
1000 | CFS_HASH_SPIN_BKTLOCK | | |
1001 | CFS_HASH_NO_ITEMREF | | |
1002 | CFS_HASH_DEPTH | | |
1003 | CFS_HASH_ASSERT_EMPTY); | |
1004 | if (s->ls_obj_hash != NULL) | |
1005 | break; | |
1006 | } | |
1007 | ||
1008 | if (s->ls_obj_hash == NULL) { | |
1009 | CERROR("failed to create lu_site hash with bits: %d\n", bits); | |
1010 | return -ENOMEM; | |
1011 | } | |
1012 | ||
1013 | cfs_hash_for_each_bucket(s->ls_obj_hash, &bd, i) { | |
1014 | bkt = cfs_hash_bd_extra_get(s->ls_obj_hash, &bd); | |
1015 | INIT_LIST_HEAD(&bkt->lsb_lru); | |
1016 | init_waitqueue_head(&bkt->lsb_marche_funebre); | |
1017 | } | |
1018 | ||
1019 | s->ls_stats = lprocfs_alloc_stats(LU_SS_LAST_STAT, 0); | |
1020 | if (s->ls_stats == NULL) { | |
1021 | cfs_hash_putref(s->ls_obj_hash); | |
1022 | s->ls_obj_hash = NULL; | |
1023 | return -ENOMEM; | |
1024 | } | |
1025 | ||
1026 | lprocfs_counter_init(s->ls_stats, LU_SS_CREATED, | |
1027 | 0, "created", "created"); | |
1028 | lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_HIT, | |
1029 | 0, "cache_hit", "cache_hit"); | |
1030 | lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_MISS, | |
1031 | 0, "cache_miss", "cache_miss"); | |
1032 | lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_RACE, | |
1033 | 0, "cache_race", "cache_race"); | |
1034 | lprocfs_counter_init(s->ls_stats, LU_SS_CACHE_DEATH_RACE, | |
1035 | 0, "cache_death_race", "cache_death_race"); | |
1036 | lprocfs_counter_init(s->ls_stats, LU_SS_LRU_PURGED, | |
1037 | 0, "lru_purged", "lru_purged"); | |
1038 | ||
1039 | INIT_LIST_HEAD(&s->ls_linkage); | |
1040 | s->ls_top_dev = top; | |
1041 | top->ld_site = s; | |
1042 | lu_device_get(top); | |
1043 | lu_ref_add(&top->ld_reference, "site-top", s); | |
1044 | ||
1045 | INIT_LIST_HEAD(&s->ls_ld_linkage); | |
1046 | spin_lock_init(&s->ls_ld_lock); | |
1047 | ||
1048 | lu_dev_add_linkage(s, top); | |
1049 | ||
0a3bdb00 | 1050 | return 0; |
d7e09d03 PT |
1051 | } |
1052 | EXPORT_SYMBOL(lu_site_init); | |
1053 | ||
1054 | /** | |
1055 | * Finalize \a s and release its resources. | |
1056 | */ | |
1057 | void lu_site_fini(struct lu_site *s) | |
1058 | { | |
1059 | mutex_lock(&lu_sites_guard); | |
1060 | list_del_init(&s->ls_linkage); | |
1061 | mutex_unlock(&lu_sites_guard); | |
1062 | ||
1063 | if (s->ls_obj_hash != NULL) { | |
1064 | cfs_hash_putref(s->ls_obj_hash); | |
1065 | s->ls_obj_hash = NULL; | |
1066 | } | |
1067 | ||
1068 | if (s->ls_top_dev != NULL) { | |
1069 | s->ls_top_dev->ld_site = NULL; | |
1070 | lu_ref_del(&s->ls_top_dev->ld_reference, "site-top", s); | |
1071 | lu_device_put(s->ls_top_dev); | |
1072 | s->ls_top_dev = NULL; | |
1073 | } | |
1074 | ||
1075 | if (s->ls_stats != NULL) | |
1076 | lprocfs_free_stats(&s->ls_stats); | |
1077 | } | |
1078 | EXPORT_SYMBOL(lu_site_fini); | |
1079 | ||
1080 | /** | |
1081 | * Called when initialization of stack for this site is completed. | |
1082 | */ | |
1083 | int lu_site_init_finish(struct lu_site *s) | |
1084 | { | |
1085 | int result; | |
1086 | mutex_lock(&lu_sites_guard); | |
1087 | result = lu_context_refill(&lu_shrink_env.le_ctx); | |
1088 | if (result == 0) | |
1089 | list_add(&s->ls_linkage, &lu_sites); | |
1090 | mutex_unlock(&lu_sites_guard); | |
1091 | return result; | |
1092 | } | |
1093 | EXPORT_SYMBOL(lu_site_init_finish); | |
1094 | ||
1095 | /** | |
1096 | * Acquire additional reference on device \a d | |
1097 | */ | |
1098 | void lu_device_get(struct lu_device *d) | |
1099 | { | |
1100 | atomic_inc(&d->ld_ref); | |
1101 | } | |
1102 | EXPORT_SYMBOL(lu_device_get); | |
1103 | ||
1104 | /** | |
1105 | * Release reference on device \a d. | |
1106 | */ | |
1107 | void lu_device_put(struct lu_device *d) | |
1108 | { | |
1109 | LASSERT(atomic_read(&d->ld_ref) > 0); | |
1110 | atomic_dec(&d->ld_ref); | |
1111 | } | |
1112 | EXPORT_SYMBOL(lu_device_put); | |
1113 | ||
1114 | /** | |
1115 | * Initialize device \a d of type \a t. | |
1116 | */ | |
1117 | int lu_device_init(struct lu_device *d, struct lu_device_type *t) | |
1118 | { | |
1119 | if (t->ldt_device_nr++ == 0 && t->ldt_ops->ldto_start != NULL) | |
1120 | t->ldt_ops->ldto_start(t); | |
ec83e611 | 1121 | memset(d, 0, sizeof(*d)); |
d7e09d03 PT |
1122 | atomic_set(&d->ld_ref, 0); |
1123 | d->ld_type = t; | |
1124 | lu_ref_init(&d->ld_reference); | |
1125 | INIT_LIST_HEAD(&d->ld_linkage); | |
1126 | return 0; | |
1127 | } | |
1128 | EXPORT_SYMBOL(lu_device_init); | |
1129 | ||
1130 | /** | |
1131 | * Finalize device \a d. | |
1132 | */ | |
1133 | void lu_device_fini(struct lu_device *d) | |
1134 | { | |
1135 | struct lu_device_type *t; | |
1136 | ||
1137 | t = d->ld_type; | |
1138 | if (d->ld_obd != NULL) { | |
1139 | d->ld_obd->obd_lu_dev = NULL; | |
1140 | d->ld_obd = NULL; | |
1141 | } | |
1142 | ||
1143 | lu_ref_fini(&d->ld_reference); | |
1144 | LASSERTF(atomic_read(&d->ld_ref) == 0, | |
1145 | "Refcount is %u\n", atomic_read(&d->ld_ref)); | |
1146 | LASSERT(t->ldt_device_nr > 0); | |
1147 | if (--t->ldt_device_nr == 0 && t->ldt_ops->ldto_stop != NULL) | |
1148 | t->ldt_ops->ldto_stop(t); | |
1149 | } | |
1150 | EXPORT_SYMBOL(lu_device_fini); | |
1151 | ||
1152 | /** | |
1153 | * Initialize object \a o that is part of compound object \a h and was created | |
1154 | * by device \a d. | |
1155 | */ | |
631abc6e JH |
1156 | int lu_object_init(struct lu_object *o, struct lu_object_header *h, |
1157 | struct lu_device *d) | |
d7e09d03 | 1158 | { |
631abc6e | 1159 | memset(o, 0, sizeof(*o)); |
d7e09d03 | 1160 | o->lo_header = h; |
631abc6e | 1161 | o->lo_dev = d; |
d7e09d03 | 1162 | lu_device_get(d); |
631abc6e | 1163 | lu_ref_add_at(&d->ld_reference, &o->lo_dev_ref, "lu_object", o); |
d7e09d03 | 1164 | INIT_LIST_HEAD(&o->lo_linkage); |
631abc6e | 1165 | |
d7e09d03 PT |
1166 | return 0; |
1167 | } | |
1168 | EXPORT_SYMBOL(lu_object_init); | |
1169 | ||
1170 | /** | |
1171 | * Finalize object and release its resources. | |
1172 | */ | |
1173 | void lu_object_fini(struct lu_object *o) | |
1174 | { | |
1175 | struct lu_device *dev = o->lo_dev; | |
1176 | ||
1177 | LASSERT(list_empty(&o->lo_linkage)); | |
1178 | ||
1179 | if (dev != NULL) { | |
631abc6e JH |
1180 | lu_ref_del_at(&dev->ld_reference, &o->lo_dev_ref, |
1181 | "lu_object", o); | |
d7e09d03 PT |
1182 | lu_device_put(dev); |
1183 | o->lo_dev = NULL; | |
1184 | } | |
1185 | } | |
1186 | EXPORT_SYMBOL(lu_object_fini); | |
1187 | ||
1188 | /** | |
1189 | * Add object \a o as first layer of compound object \a h | |
1190 | * | |
1191 | * This is typically called by the ->ldo_object_alloc() method of top-level | |
1192 | * device. | |
1193 | */ | |
1194 | void lu_object_add_top(struct lu_object_header *h, struct lu_object *o) | |
1195 | { | |
1196 | list_move(&o->lo_linkage, &h->loh_layers); | |
1197 | } | |
1198 | EXPORT_SYMBOL(lu_object_add_top); | |
1199 | ||
1200 | /** | |
1201 | * Add object \a o as a layer of compound object, going after \a before. | |
1202 | * | |
1203 | * This is typically called by the ->ldo_object_alloc() method of \a | |
1204 | * before->lo_dev. | |
1205 | */ | |
1206 | void lu_object_add(struct lu_object *before, struct lu_object *o) | |
1207 | { | |
1208 | list_move(&o->lo_linkage, &before->lo_linkage); | |
1209 | } | |
1210 | EXPORT_SYMBOL(lu_object_add); | |
1211 | ||
1212 | /** | |
1213 | * Initialize compound object. | |
1214 | */ | |
1215 | int lu_object_header_init(struct lu_object_header *h) | |
1216 | { | |
ec83e611 | 1217 | memset(h, 0, sizeof(*h)); |
d7e09d03 PT |
1218 | atomic_set(&h->loh_ref, 1); |
1219 | INIT_HLIST_NODE(&h->loh_hash); | |
1220 | INIT_LIST_HEAD(&h->loh_lru); | |
1221 | INIT_LIST_HEAD(&h->loh_layers); | |
1222 | lu_ref_init(&h->loh_reference); | |
1223 | return 0; | |
1224 | } | |
1225 | EXPORT_SYMBOL(lu_object_header_init); | |
1226 | ||
1227 | /** | |
1228 | * Finalize compound object. | |
1229 | */ | |
1230 | void lu_object_header_fini(struct lu_object_header *h) | |
1231 | { | |
1232 | LASSERT(list_empty(&h->loh_layers)); | |
1233 | LASSERT(list_empty(&h->loh_lru)); | |
1234 | LASSERT(hlist_unhashed(&h->loh_hash)); | |
1235 | lu_ref_fini(&h->loh_reference); | |
1236 | } | |
1237 | EXPORT_SYMBOL(lu_object_header_fini); | |
1238 | ||
1239 | /** | |
1240 | * Given a compound object, find its slice, corresponding to the device type | |
1241 | * \a dtype. | |
1242 | */ | |
1243 | struct lu_object *lu_object_locate(struct lu_object_header *h, | |
1244 | const struct lu_device_type *dtype) | |
1245 | { | |
1246 | struct lu_object *o; | |
1247 | ||
1248 | list_for_each_entry(o, &h->loh_layers, lo_linkage) { | |
1249 | if (o->lo_dev->ld_type == dtype) | |
1250 | return o; | |
1251 | } | |
1252 | return NULL; | |
1253 | } | |
1254 | EXPORT_SYMBOL(lu_object_locate); | |
1255 | ||
1256 | ||
1257 | ||
1258 | /** | |
1259 | * Finalize and free devices in the device stack. | |
1260 | * | |
1261 | * Finalize device stack by purging object cache, and calling | |
1262 | * lu_device_type_operations::ldto_device_fini() and | |
1263 | * lu_device_type_operations::ldto_device_free() on all devices in the stack. | |
1264 | */ | |
1265 | void lu_stack_fini(const struct lu_env *env, struct lu_device *top) | |
1266 | { | |
1267 | struct lu_site *site = top->ld_site; | |
1268 | struct lu_device *scan; | |
1269 | struct lu_device *next; | |
1270 | ||
1271 | lu_site_purge(env, site, ~0); | |
1272 | for (scan = top; scan != NULL; scan = next) { | |
1273 | next = scan->ld_type->ldt_ops->ldto_device_fini(env, scan); | |
1274 | lu_ref_del(&scan->ld_reference, "lu-stack", &lu_site_init); | |
1275 | lu_device_put(scan); | |
1276 | } | |
1277 | ||
1278 | /* purge again. */ | |
1279 | lu_site_purge(env, site, ~0); | |
1280 | ||
1281 | for (scan = top; scan != NULL; scan = next) { | |
1282 | const struct lu_device_type *ldt = scan->ld_type; | |
1283 | struct obd_type *type; | |
1284 | ||
1285 | next = ldt->ldt_ops->ldto_device_free(env, scan); | |
1286 | type = ldt->ldt_obd_type; | |
1287 | if (type != NULL) { | |
1288 | type->typ_refcnt--; | |
1289 | class_put_type(type); | |
1290 | } | |
1291 | } | |
1292 | } | |
1293 | EXPORT_SYMBOL(lu_stack_fini); | |
1294 | ||
1295 | enum { | |
1296 | /** | |
1297 | * Maximal number of tld slots. | |
1298 | */ | |
1299 | LU_CONTEXT_KEY_NR = 40 | |
1300 | }; | |
1301 | ||
1302 | static struct lu_context_key *lu_keys[LU_CONTEXT_KEY_NR] = { NULL, }; | |
1303 | ||
1304 | static DEFINE_SPINLOCK(lu_keys_guard); | |
1305 | ||
1306 | /** | |
1307 | * Global counter incremented whenever key is registered, unregistered, | |
1308 | * revived or quiesced. This is used to void unnecessary calls to | |
1309 | * lu_context_refill(). No locking is provided, as initialization and shutdown | |
1310 | * are supposed to be externally serialized. | |
1311 | */ | |
1312 | static unsigned key_set_version = 0; | |
1313 | ||
1314 | /** | |
1315 | * Register new key. | |
1316 | */ | |
1317 | int lu_context_key_register(struct lu_context_key *key) | |
1318 | { | |
1319 | int result; | |
1320 | int i; | |
1321 | ||
1322 | LASSERT(key->lct_init != NULL); | |
1323 | LASSERT(key->lct_fini != NULL); | |
1324 | LASSERT(key->lct_tags != 0); | |
d7e09d03 PT |
1325 | |
1326 | result = -ENFILE; | |
1327 | spin_lock(&lu_keys_guard); | |
1328 | for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { | |
1329 | if (lu_keys[i] == NULL) { | |
1330 | key->lct_index = i; | |
1331 | atomic_set(&key->lct_used, 1); | |
1332 | lu_keys[i] = key; | |
1333 | lu_ref_init(&key->lct_reference); | |
1334 | result = 0; | |
1335 | ++key_set_version; | |
1336 | break; | |
1337 | } | |
1338 | } | |
1339 | spin_unlock(&lu_keys_guard); | |
1340 | return result; | |
1341 | } | |
1342 | EXPORT_SYMBOL(lu_context_key_register); | |
1343 | ||
1344 | static void key_fini(struct lu_context *ctx, int index) | |
1345 | { | |
1346 | if (ctx->lc_value != NULL && ctx->lc_value[index] != NULL) { | |
1347 | struct lu_context_key *key; | |
1348 | ||
1349 | key = lu_keys[index]; | |
1350 | LASSERT(key != NULL); | |
1351 | LASSERT(key->lct_fini != NULL); | |
1352 | LASSERT(atomic_read(&key->lct_used) > 1); | |
1353 | ||
1354 | key->lct_fini(ctx, key, ctx->lc_value[index]); | |
1355 | lu_ref_del(&key->lct_reference, "ctx", ctx); | |
1356 | atomic_dec(&key->lct_used); | |
1357 | ||
d7e09d03 | 1358 | if ((ctx->lc_tags & LCT_NOREF) == 0) { |
4a1a01ea | 1359 | #ifdef CONFIG_MODULE_UNLOAD |
d7e09d03 | 1360 | LINVRNT(module_refcount(key->lct_owner) > 0); |
4a1a01ea | 1361 | #endif |
d7e09d03 PT |
1362 | module_put(key->lct_owner); |
1363 | } | |
1364 | ctx->lc_value[index] = NULL; | |
1365 | } | |
1366 | } | |
1367 | ||
1368 | /** | |
1369 | * Deregister key. | |
1370 | */ | |
1371 | void lu_context_key_degister(struct lu_context_key *key) | |
1372 | { | |
1373 | LASSERT(atomic_read(&key->lct_used) >= 1); | |
1374 | LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys)); | |
1375 | ||
1376 | lu_context_key_quiesce(key); | |
1377 | ||
1378 | ++key_set_version; | |
1379 | spin_lock(&lu_keys_guard); | |
1380 | key_fini(&lu_shrink_env.le_ctx, key->lct_index); | |
1381 | if (lu_keys[key->lct_index]) { | |
1382 | lu_keys[key->lct_index] = NULL; | |
1383 | lu_ref_fini(&key->lct_reference); | |
1384 | } | |
1385 | spin_unlock(&lu_keys_guard); | |
1386 | ||
1387 | LASSERTF(atomic_read(&key->lct_used) == 1, | |
1388 | "key has instances: %d\n", | |
1389 | atomic_read(&key->lct_used)); | |
1390 | } | |
1391 | EXPORT_SYMBOL(lu_context_key_degister); | |
1392 | ||
1393 | /** | |
1394 | * Register a number of keys. This has to be called after all keys have been | |
1395 | * initialized by a call to LU_CONTEXT_KEY_INIT(). | |
1396 | */ | |
1397 | int lu_context_key_register_many(struct lu_context_key *k, ...) | |
1398 | { | |
1399 | struct lu_context_key *key = k; | |
1400 | va_list args; | |
1401 | int result; | |
1402 | ||
1403 | va_start(args, k); | |
1404 | do { | |
1405 | result = lu_context_key_register(key); | |
1406 | if (result) | |
1407 | break; | |
1408 | key = va_arg(args, struct lu_context_key *); | |
1409 | } while (key != NULL); | |
1410 | va_end(args); | |
1411 | ||
1412 | if (result != 0) { | |
1413 | va_start(args, k); | |
1414 | while (k != key) { | |
1415 | lu_context_key_degister(k); | |
1416 | k = va_arg(args, struct lu_context_key *); | |
1417 | } | |
1418 | va_end(args); | |
1419 | } | |
1420 | ||
1421 | return result; | |
1422 | } | |
1423 | EXPORT_SYMBOL(lu_context_key_register_many); | |
1424 | ||
1425 | /** | |
1426 | * De-register a number of keys. This is a dual to | |
1427 | * lu_context_key_register_many(). | |
1428 | */ | |
1429 | void lu_context_key_degister_many(struct lu_context_key *k, ...) | |
1430 | { | |
1431 | va_list args; | |
1432 | ||
1433 | va_start(args, k); | |
1434 | do { | |
1435 | lu_context_key_degister(k); | |
1436 | k = va_arg(args, struct lu_context_key*); | |
1437 | } while (k != NULL); | |
1438 | va_end(args); | |
1439 | } | |
1440 | EXPORT_SYMBOL(lu_context_key_degister_many); | |
1441 | ||
1442 | /** | |
1443 | * Revive a number of keys. | |
1444 | */ | |
1445 | void lu_context_key_revive_many(struct lu_context_key *k, ...) | |
1446 | { | |
1447 | va_list args; | |
1448 | ||
1449 | va_start(args, k); | |
1450 | do { | |
1451 | lu_context_key_revive(k); | |
1452 | k = va_arg(args, struct lu_context_key*); | |
1453 | } while (k != NULL); | |
1454 | va_end(args); | |
1455 | } | |
1456 | EXPORT_SYMBOL(lu_context_key_revive_many); | |
1457 | ||
1458 | /** | |
1459 | * Quiescent a number of keys. | |
1460 | */ | |
1461 | void lu_context_key_quiesce_many(struct lu_context_key *k, ...) | |
1462 | { | |
1463 | va_list args; | |
1464 | ||
1465 | va_start(args, k); | |
1466 | do { | |
1467 | lu_context_key_quiesce(k); | |
1468 | k = va_arg(args, struct lu_context_key*); | |
1469 | } while (k != NULL); | |
1470 | va_end(args); | |
1471 | } | |
1472 | EXPORT_SYMBOL(lu_context_key_quiesce_many); | |
1473 | ||
1474 | /** | |
1475 | * Return value associated with key \a key in context \a ctx. | |
1476 | */ | |
1477 | void *lu_context_key_get(const struct lu_context *ctx, | |
1478 | const struct lu_context_key *key) | |
1479 | { | |
1480 | LINVRNT(ctx->lc_state == LCS_ENTERED); | |
1481 | LINVRNT(0 <= key->lct_index && key->lct_index < ARRAY_SIZE(lu_keys)); | |
1482 | LASSERT(lu_keys[key->lct_index] == key); | |
1483 | return ctx->lc_value[key->lct_index]; | |
1484 | } | |
1485 | EXPORT_SYMBOL(lu_context_key_get); | |
1486 | ||
1487 | /** | |
1488 | * List of remembered contexts. XXX document me. | |
1489 | */ | |
1490 | static LIST_HEAD(lu_context_remembered); | |
1491 | ||
1492 | /** | |
1493 | * Destroy \a key in all remembered contexts. This is used to destroy key | |
1494 | * values in "shared" contexts (like service threads), when a module owning | |
1495 | * the key is about to be unloaded. | |
1496 | */ | |
1497 | void lu_context_key_quiesce(struct lu_context_key *key) | |
1498 | { | |
1499 | struct lu_context *ctx; | |
1500 | ||
1501 | if (!(key->lct_tags & LCT_QUIESCENT)) { | |
1502 | /* | |
1503 | * XXX layering violation. | |
1504 | */ | |
1505 | key->lct_tags |= LCT_QUIESCENT; | |
1506 | /* | |
1507 | * XXX memory barrier has to go here. | |
1508 | */ | |
1509 | spin_lock(&lu_keys_guard); | |
1510 | list_for_each_entry(ctx, &lu_context_remembered, | |
1511 | lc_remember) | |
1512 | key_fini(ctx, key->lct_index); | |
1513 | spin_unlock(&lu_keys_guard); | |
1514 | ++key_set_version; | |
1515 | } | |
1516 | } | |
1517 | EXPORT_SYMBOL(lu_context_key_quiesce); | |
1518 | ||
1519 | void lu_context_key_revive(struct lu_context_key *key) | |
1520 | { | |
1521 | key->lct_tags &= ~LCT_QUIESCENT; | |
1522 | ++key_set_version; | |
1523 | } | |
1524 | EXPORT_SYMBOL(lu_context_key_revive); | |
1525 | ||
1526 | static void keys_fini(struct lu_context *ctx) | |
1527 | { | |
1528 | int i; | |
1529 | ||
1530 | if (ctx->lc_value == NULL) | |
1531 | return; | |
1532 | ||
1533 | for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) | |
1534 | key_fini(ctx, i); | |
1535 | ||
ec83e611 | 1536 | OBD_FREE(ctx->lc_value, ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0])); |
d7e09d03 PT |
1537 | ctx->lc_value = NULL; |
1538 | } | |
1539 | ||
1540 | static int keys_fill(struct lu_context *ctx) | |
1541 | { | |
1542 | int i; | |
1543 | ||
1544 | LINVRNT(ctx->lc_value != NULL); | |
1545 | for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { | |
1546 | struct lu_context_key *key; | |
1547 | ||
1548 | key = lu_keys[i]; | |
1549 | if (ctx->lc_value[i] == NULL && key != NULL && | |
1550 | (key->lct_tags & ctx->lc_tags) && | |
1551 | /* | |
1552 | * Don't create values for a LCT_QUIESCENT key, as this | |
1553 | * will pin module owning a key. | |
1554 | */ | |
1555 | !(key->lct_tags & LCT_QUIESCENT)) { | |
1556 | void *value; | |
1557 | ||
1558 | LINVRNT(key->lct_init != NULL); | |
1559 | LINVRNT(key->lct_index == i); | |
1560 | ||
1561 | value = key->lct_init(ctx, key); | |
1562 | if (unlikely(IS_ERR(value))) | |
1563 | return PTR_ERR(value); | |
1564 | ||
d7e09d03 PT |
1565 | if (!(ctx->lc_tags & LCT_NOREF)) |
1566 | try_module_get(key->lct_owner); | |
1567 | lu_ref_add_atomic(&key->lct_reference, "ctx", ctx); | |
1568 | atomic_inc(&key->lct_used); | |
1569 | /* | |
1570 | * This is the only place in the code, where an | |
1571 | * element of ctx->lc_value[] array is set to non-NULL | |
1572 | * value. | |
1573 | */ | |
1574 | ctx->lc_value[i] = value; | |
1575 | if (key->lct_exit != NULL) | |
1576 | ctx->lc_tags |= LCT_HAS_EXIT; | |
1577 | } | |
1578 | ctx->lc_version = key_set_version; | |
1579 | } | |
1580 | return 0; | |
1581 | } | |
1582 | ||
1583 | static int keys_init(struct lu_context *ctx) | |
1584 | { | |
ec83e611 JP |
1585 | OBD_ALLOC(ctx->lc_value, |
1586 | ARRAY_SIZE(lu_keys) * sizeof(ctx->lc_value[0])); | |
d7e09d03 PT |
1587 | if (likely(ctx->lc_value != NULL)) |
1588 | return keys_fill(ctx); | |
1589 | ||
1590 | return -ENOMEM; | |
1591 | } | |
1592 | ||
1593 | /** | |
1594 | * Initialize context data-structure. Create values for all keys. | |
1595 | */ | |
1596 | int lu_context_init(struct lu_context *ctx, __u32 tags) | |
1597 | { | |
1598 | int rc; | |
1599 | ||
ec83e611 | 1600 | memset(ctx, 0, sizeof(*ctx)); |
d7e09d03 PT |
1601 | ctx->lc_state = LCS_INITIALIZED; |
1602 | ctx->lc_tags = tags; | |
1603 | if (tags & LCT_REMEMBER) { | |
1604 | spin_lock(&lu_keys_guard); | |
1605 | list_add(&ctx->lc_remember, &lu_context_remembered); | |
1606 | spin_unlock(&lu_keys_guard); | |
1607 | } else { | |
1608 | INIT_LIST_HEAD(&ctx->lc_remember); | |
1609 | } | |
1610 | ||
1611 | rc = keys_init(ctx); | |
1612 | if (rc != 0) | |
1613 | lu_context_fini(ctx); | |
1614 | ||
1615 | return rc; | |
1616 | } | |
1617 | EXPORT_SYMBOL(lu_context_init); | |
1618 | ||
1619 | /** | |
1620 | * Finalize context data-structure. Destroy key values. | |
1621 | */ | |
1622 | void lu_context_fini(struct lu_context *ctx) | |
1623 | { | |
1624 | LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT); | |
1625 | ctx->lc_state = LCS_FINALIZED; | |
1626 | ||
1627 | if ((ctx->lc_tags & LCT_REMEMBER) == 0) { | |
1628 | LASSERT(list_empty(&ctx->lc_remember)); | |
1629 | keys_fini(ctx); | |
1630 | ||
1631 | } else { /* could race with key degister */ | |
1632 | spin_lock(&lu_keys_guard); | |
1633 | keys_fini(ctx); | |
1634 | list_del_init(&ctx->lc_remember); | |
1635 | spin_unlock(&lu_keys_guard); | |
1636 | } | |
1637 | } | |
1638 | EXPORT_SYMBOL(lu_context_fini); | |
1639 | ||
1640 | /** | |
1641 | * Called before entering context. | |
1642 | */ | |
1643 | void lu_context_enter(struct lu_context *ctx) | |
1644 | { | |
1645 | LINVRNT(ctx->lc_state == LCS_INITIALIZED || ctx->lc_state == LCS_LEFT); | |
1646 | ctx->lc_state = LCS_ENTERED; | |
1647 | } | |
1648 | EXPORT_SYMBOL(lu_context_enter); | |
1649 | ||
1650 | /** | |
1651 | * Called after exiting from \a ctx | |
1652 | */ | |
1653 | void lu_context_exit(struct lu_context *ctx) | |
1654 | { | |
1655 | int i; | |
1656 | ||
1657 | LINVRNT(ctx->lc_state == LCS_ENTERED); | |
1658 | ctx->lc_state = LCS_LEFT; | |
1659 | if (ctx->lc_tags & LCT_HAS_EXIT && ctx->lc_value != NULL) { | |
1660 | for (i = 0; i < ARRAY_SIZE(lu_keys); ++i) { | |
1661 | if (ctx->lc_value[i] != NULL) { | |
1662 | struct lu_context_key *key; | |
1663 | ||
1664 | key = lu_keys[i]; | |
1665 | LASSERT(key != NULL); | |
1666 | if (key->lct_exit != NULL) | |
1667 | key->lct_exit(ctx, | |
1668 | key, ctx->lc_value[i]); | |
1669 | } | |
1670 | } | |
1671 | } | |
1672 | } | |
1673 | EXPORT_SYMBOL(lu_context_exit); | |
1674 | ||
1675 | /** | |
1676 | * Allocate for context all missing keys that were registered after context | |
1677 | * creation. key_set_version is only changed in rare cases when modules | |
1678 | * are loaded and removed. | |
1679 | */ | |
1680 | int lu_context_refill(struct lu_context *ctx) | |
1681 | { | |
1682 | return likely(ctx->lc_version == key_set_version) ? 0 : keys_fill(ctx); | |
1683 | } | |
1684 | EXPORT_SYMBOL(lu_context_refill); | |
1685 | ||
1686 | /** | |
1687 | * lu_ctx_tags/lu_ses_tags will be updated if there are new types of | |
1688 | * obd being added. Currently, this is only used on client side, specifically | |
1689 | * for echo device client, for other stack (like ptlrpc threads), context are | |
1690 | * predefined when the lu_device type are registered, during the module probe | |
1691 | * phase. | |
1692 | */ | |
1693 | __u32 lu_context_tags_default = 0; | |
1694 | __u32 lu_session_tags_default = 0; | |
1695 | ||
1696 | void lu_context_tags_update(__u32 tags) | |
1697 | { | |
1698 | spin_lock(&lu_keys_guard); | |
1699 | lu_context_tags_default |= tags; | |
1700 | key_set_version++; | |
1701 | spin_unlock(&lu_keys_guard); | |
1702 | } | |
1703 | EXPORT_SYMBOL(lu_context_tags_update); | |
1704 | ||
1705 | void lu_context_tags_clear(__u32 tags) | |
1706 | { | |
1707 | spin_lock(&lu_keys_guard); | |
1708 | lu_context_tags_default &= ~tags; | |
1709 | key_set_version++; | |
1710 | spin_unlock(&lu_keys_guard); | |
1711 | } | |
1712 | EXPORT_SYMBOL(lu_context_tags_clear); | |
1713 | ||
1714 | void lu_session_tags_update(__u32 tags) | |
1715 | { | |
1716 | spin_lock(&lu_keys_guard); | |
1717 | lu_session_tags_default |= tags; | |
1718 | key_set_version++; | |
1719 | spin_unlock(&lu_keys_guard); | |
1720 | } | |
1721 | EXPORT_SYMBOL(lu_session_tags_update); | |
1722 | ||
1723 | void lu_session_tags_clear(__u32 tags) | |
1724 | { | |
1725 | spin_lock(&lu_keys_guard); | |
1726 | lu_session_tags_default &= ~tags; | |
1727 | key_set_version++; | |
1728 | spin_unlock(&lu_keys_guard); | |
1729 | } | |
1730 | EXPORT_SYMBOL(lu_session_tags_clear); | |
1731 | ||
1732 | int lu_env_init(struct lu_env *env, __u32 tags) | |
1733 | { | |
1734 | int result; | |
1735 | ||
1736 | env->le_ses = NULL; | |
1737 | result = lu_context_init(&env->le_ctx, tags); | |
1738 | if (likely(result == 0)) | |
1739 | lu_context_enter(&env->le_ctx); | |
1740 | return result; | |
1741 | } | |
1742 | EXPORT_SYMBOL(lu_env_init); | |
1743 | ||
1744 | void lu_env_fini(struct lu_env *env) | |
1745 | { | |
1746 | lu_context_exit(&env->le_ctx); | |
1747 | lu_context_fini(&env->le_ctx); | |
1748 | env->le_ses = NULL; | |
1749 | } | |
1750 | EXPORT_SYMBOL(lu_env_fini); | |
1751 | ||
1752 | int lu_env_refill(struct lu_env *env) | |
1753 | { | |
1754 | int result; | |
1755 | ||
1756 | result = lu_context_refill(&env->le_ctx); | |
1757 | if (result == 0 && env->le_ses != NULL) | |
1758 | result = lu_context_refill(env->le_ses); | |
1759 | return result; | |
1760 | } | |
1761 | EXPORT_SYMBOL(lu_env_refill); | |
1762 | ||
1763 | /** | |
1764 | * Currently, this API will only be used by echo client. | |
1765 | * Because echo client and normal lustre client will share | |
1766 | * same cl_env cache. So echo client needs to refresh | |
1767 | * the env context after it get one from the cache, especially | |
1768 | * when normal client and echo client co-exist in the same client. | |
1769 | */ | |
1770 | int lu_env_refill_by_tags(struct lu_env *env, __u32 ctags, | |
1771 | __u32 stags) | |
1772 | { | |
1773 | int result; | |
1774 | ||
1775 | if ((env->le_ctx.lc_tags & ctags) != ctags) { | |
1776 | env->le_ctx.lc_version = 0; | |
1777 | env->le_ctx.lc_tags |= ctags; | |
1778 | } | |
1779 | ||
1780 | if (env->le_ses && (env->le_ses->lc_tags & stags) != stags) { | |
1781 | env->le_ses->lc_version = 0; | |
1782 | env->le_ses->lc_tags |= stags; | |
1783 | } | |
1784 | ||
1785 | result = lu_env_refill(env); | |
1786 | ||
1787 | return result; | |
1788 | } | |
1789 | EXPORT_SYMBOL(lu_env_refill_by_tags); | |
1790 | ||
d7e09d03 PT |
1791 | |
1792 | typedef struct lu_site_stats{ | |
1793 | unsigned lss_populated; | |
1794 | unsigned lss_max_search; | |
1795 | unsigned lss_total; | |
1796 | unsigned lss_busy; | |
1797 | } lu_site_stats_t; | |
1798 | ||
6da6eabe | 1799 | static void lu_site_stats_get(struct cfs_hash *hs, |
d7e09d03 PT |
1800 | lu_site_stats_t *stats, int populated) |
1801 | { | |
6ea510c1 | 1802 | struct cfs_hash_bd bd; |
d7e09d03 PT |
1803 | int i; |
1804 | ||
1805 | cfs_hash_for_each_bucket(hs, &bd, i) { | |
1806 | struct lu_site_bkt_data *bkt = cfs_hash_bd_extra_get(hs, &bd); | |
1807 | struct hlist_head *hhead; | |
1808 | ||
1809 | cfs_hash_bd_lock(hs, &bd, 1); | |
1810 | stats->lss_busy += bkt->lsb_busy; | |
1811 | stats->lss_total += cfs_hash_bd_count_get(&bd); | |
1812 | stats->lss_max_search = max((int)stats->lss_max_search, | |
1813 | cfs_hash_bd_depmax_get(&bd)); | |
1814 | if (!populated) { | |
1815 | cfs_hash_bd_unlock(hs, &bd, 1); | |
1816 | continue; | |
1817 | } | |
1818 | ||
1819 | cfs_hash_bd_for_each_hlist(hs, &bd, hhead) { | |
1820 | if (!hlist_empty(hhead)) | |
1821 | stats->lss_populated++; | |
1822 | } | |
1823 | cfs_hash_bd_unlock(hs, &bd, 1); | |
1824 | } | |
1825 | } | |
1826 | ||
1827 | ||
1828 | /* | |
1829 | * There exists a potential lock inversion deadlock scenario when using | |
1830 | * Lustre on top of ZFS. This occurs between one of ZFS's | |
1831 | * buf_hash_table.ht_lock's, and Lustre's lu_sites_guard lock. Essentially, | |
1832 | * thread A will take the lu_sites_guard lock and sleep on the ht_lock, | |
1833 | * while thread B will take the ht_lock and sleep on the lu_sites_guard | |
1834 | * lock. Obviously neither thread will wake and drop their respective hold | |
1835 | * on their lock. | |
1836 | * | |
1837 | * To prevent this from happening we must ensure the lu_sites_guard lock is | |
1838 | * not taken while down this code path. ZFS reliably does not set the | |
1839 | * __GFP_FS bit in its code paths, so this can be used to determine if it | |
1840 | * is safe to take the lu_sites_guard lock. | |
1841 | * | |
1842 | * Ideally we should accurately return the remaining number of cached | |
1843 | * objects without taking the lu_sites_guard lock, but this is not | |
1844 | * possible in the current implementation. | |
1845 | */ | |
fe92a055 PT |
1846 | static unsigned long lu_cache_shrink_count(struct shrinker *sk, |
1847 | struct shrink_control *sc) | |
d7e09d03 PT |
1848 | { |
1849 | lu_site_stats_t stats; | |
1850 | struct lu_site *s; | |
1851 | struct lu_site *tmp; | |
fe92a055 | 1852 | unsigned long cached = 0; |
d7e09d03 | 1853 | |
fe92a055 PT |
1854 | if (!(sc->gfp_mask & __GFP_FS)) |
1855 | return 0; | |
d7e09d03 PT |
1856 | |
1857 | mutex_lock(&lu_sites_guard); | |
1858 | list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) { | |
d7e09d03 PT |
1859 | memset(&stats, 0, sizeof(stats)); |
1860 | lu_site_stats_get(s->ls_obj_hash, &stats, 0); | |
1861 | cached += stats.lss_total - stats.lss_busy; | |
d7e09d03 | 1862 | } |
d7e09d03 PT |
1863 | mutex_unlock(&lu_sites_guard); |
1864 | ||
1865 | cached = (cached / 100) * sysctl_vfs_cache_pressure; | |
fe92a055 | 1866 | CDEBUG(D_INODE, "%ld objects cached\n", cached); |
d7e09d03 PT |
1867 | return cached; |
1868 | } | |
1869 | ||
fe92a055 PT |
1870 | static unsigned long lu_cache_shrink_scan(struct shrinker *sk, |
1871 | struct shrink_control *sc) | |
1872 | { | |
1873 | struct lu_site *s; | |
1874 | struct lu_site *tmp; | |
1875 | unsigned long remain = sc->nr_to_scan, freed = 0; | |
1876 | LIST_HEAD(splice); | |
1877 | ||
1878 | if (!(sc->gfp_mask & __GFP_FS)) | |
1879 | /* We must not take the lu_sites_guard lock when | |
1880 | * __GFP_FS is *not* set because of the deadlock | |
1881 | * possibility detailed above. Additionally, | |
1882 | * since we cannot determine the number of | |
1883 | * objects in the cache without taking this | |
1884 | * lock, we're in a particularly tough spot. As | |
1885 | * a result, we'll just lie and say our cache is | |
1886 | * empty. This _should_ be ok, as we can't | |
1887 | * reclaim objects when __GFP_FS is *not* set | |
1888 | * anyways. | |
1889 | */ | |
1890 | return SHRINK_STOP; | |
1891 | ||
1892 | mutex_lock(&lu_sites_guard); | |
1893 | list_for_each_entry_safe(s, tmp, &lu_sites, ls_linkage) { | |
1894 | freed = lu_site_purge(&lu_shrink_env, s, remain); | |
1895 | remain -= freed; | |
1896 | /* | |
1897 | * Move just shrunk site to the tail of site list to | |
1898 | * assure shrinking fairness. | |
1899 | */ | |
1900 | list_move_tail(&s->ls_linkage, &splice); | |
1901 | } | |
1902 | list_splice(&splice, lu_sites.prev); | |
1903 | mutex_unlock(&lu_sites_guard); | |
1904 | ||
1905 | return sc->nr_to_scan - remain; | |
1906 | } | |
1907 | ||
d7e09d03 PT |
1908 | /* |
1909 | * Debugging stuff. | |
1910 | */ | |
1911 | ||
1912 | /** | |
1913 | * Environment to be used in debugger, contains all tags. | |
1914 | */ | |
1915 | struct lu_env lu_debugging_env; | |
1916 | ||
1917 | /** | |
1918 | * Debugging printer function using printk(). | |
1919 | */ | |
1920 | int lu_printk_printer(const struct lu_env *env, | |
1921 | void *unused, const char *format, ...) | |
1922 | { | |
1923 | va_list args; | |
1924 | ||
1925 | va_start(args, format); | |
1926 | vprintk(format, args); | |
1927 | va_end(args); | |
1928 | return 0; | |
1929 | } | |
1930 | ||
fe92a055 PT |
1931 | static struct shrinker lu_site_shrinker = { |
1932 | .count_objects = lu_cache_shrink_count, | |
1933 | .scan_objects = lu_cache_shrink_scan, | |
1934 | .seeks = DEFAULT_SEEKS, | |
1935 | }; | |
1936 | ||
d7e09d03 PT |
1937 | /** |
1938 | * Initialization of global lu_* data. | |
1939 | */ | |
1940 | int lu_global_init(void) | |
1941 | { | |
1942 | int result; | |
1943 | ||
1944 | CDEBUG(D_INFO, "Lustre LU module (%p).\n", &lu_keys); | |
1945 | ||
1946 | result = lu_ref_global_init(); | |
1947 | if (result != 0) | |
1948 | return result; | |
1949 | ||
1950 | LU_CONTEXT_KEY_INIT(&lu_global_key); | |
1951 | result = lu_context_key_register(&lu_global_key); | |
1952 | if (result != 0) | |
1953 | return result; | |
1954 | ||
1955 | /* | |
1956 | * At this level, we don't know what tags are needed, so allocate them | |
1957 | * conservatively. This should not be too bad, because this | |
1958 | * environment is global. | |
1959 | */ | |
1960 | mutex_lock(&lu_sites_guard); | |
1961 | result = lu_env_init(&lu_shrink_env, LCT_SHRINKER); | |
1962 | mutex_unlock(&lu_sites_guard); | |
1963 | if (result != 0) | |
1964 | return result; | |
1965 | ||
1966 | /* | |
1967 | * seeks estimation: 3 seeks to read a record from oi, one to read | |
1968 | * inode, one for ea. Unfortunately setting this high value results in | |
1969 | * lu_object/inode cache consuming all the memory. | |
1970 | */ | |
fe92a055 | 1971 | register_shrinker(&lu_site_shrinker); |
d7e09d03 PT |
1972 | |
1973 | return result; | |
1974 | } | |
1975 | ||
1976 | /** | |
1977 | * Dual to lu_global_init(). | |
1978 | */ | |
1979 | void lu_global_fini(void) | |
1980 | { | |
fe92a055 | 1981 | unregister_shrinker(&lu_site_shrinker); |
d7e09d03 PT |
1982 | lu_context_key_degister(&lu_global_key); |
1983 | ||
1984 | /* | |
1985 | * Tear shrinker environment down _after_ de-registering | |
1986 | * lu_global_key, because the latter has a value in the former. | |
1987 | */ | |
1988 | mutex_lock(&lu_sites_guard); | |
1989 | lu_env_fini(&lu_shrink_env); | |
1990 | mutex_unlock(&lu_sites_guard); | |
1991 | ||
1992 | lu_ref_global_fini(); | |
1993 | } | |
1994 | ||
1995 | static __u32 ls_stats_read(struct lprocfs_stats *stats, int idx) | |
1996 | { | |
1997 | #ifdef LPROCFS | |
1998 | struct lprocfs_counter ret; | |
1999 | ||
2000 | lprocfs_stats_collect(stats, idx, &ret); | |
2001 | return (__u32)ret.lc_count; | |
2002 | #else | |
2003 | return 0; | |
2004 | #endif | |
2005 | } | |
2006 | ||
2007 | /** | |
2008 | * Output site statistical counters into a buffer. Suitable for | |
2009 | * lprocfs_rd_*()-style functions. | |
2010 | */ | |
73bb1da6 | 2011 | int lu_site_stats_print(const struct lu_site *s, struct seq_file *m) |
d7e09d03 PT |
2012 | { |
2013 | lu_site_stats_t stats; | |
2014 | ||
2015 | memset(&stats, 0, sizeof(stats)); | |
2016 | lu_site_stats_get(s->ls_obj_hash, &stats, 1); | |
2017 | ||
73bb1da6 | 2018 | return seq_printf(m, "%d/%d %d/%d %d %d %d %d %d %d %d\n", |
d7e09d03 PT |
2019 | stats.lss_busy, |
2020 | stats.lss_total, | |
2021 | stats.lss_populated, | |
2022 | CFS_HASH_NHLIST(s->ls_obj_hash), | |
2023 | stats.lss_max_search, | |
2024 | ls_stats_read(s->ls_stats, LU_SS_CREATED), | |
2025 | ls_stats_read(s->ls_stats, LU_SS_CACHE_HIT), | |
2026 | ls_stats_read(s->ls_stats, LU_SS_CACHE_MISS), | |
2027 | ls_stats_read(s->ls_stats, LU_SS_CACHE_RACE), | |
2028 | ls_stats_read(s->ls_stats, LU_SS_CACHE_DEATH_RACE), | |
2029 | ls_stats_read(s->ls_stats, LU_SS_LRU_PURGED)); | |
2030 | } | |
2031 | EXPORT_SYMBOL(lu_site_stats_print); | |
2032 | ||
2033 | /** | |
2034 | * Helper function to initialize a number of kmem slab caches at once. | |
2035 | */ | |
2036 | int lu_kmem_init(struct lu_kmem_descr *caches) | |
2037 | { | |
2038 | int result; | |
2039 | struct lu_kmem_descr *iter = caches; | |
2040 | ||
2041 | for (result = 0; iter->ckd_cache != NULL; ++iter) { | |
2042 | *iter->ckd_cache = kmem_cache_create(iter->ckd_name, | |
2043 | iter->ckd_size, | |
2044 | 0, 0, NULL); | |
2045 | if (*iter->ckd_cache == NULL) { | |
2046 | result = -ENOMEM; | |
2047 | /* free all previously allocated caches */ | |
2048 | lu_kmem_fini(caches); | |
2049 | break; | |
2050 | } | |
2051 | } | |
2052 | return result; | |
2053 | } | |
2054 | EXPORT_SYMBOL(lu_kmem_init); | |
2055 | ||
2056 | /** | |
2057 | * Helper function to finalize a number of kmem slab cached at once. Dual to | |
2058 | * lu_kmem_init(). | |
2059 | */ | |
2060 | void lu_kmem_fini(struct lu_kmem_descr *caches) | |
2061 | { | |
2062 | for (; caches->ckd_cache != NULL; ++caches) { | |
2063 | if (*caches->ckd_cache != NULL) { | |
2064 | kmem_cache_destroy(*caches->ckd_cache); | |
2065 | *caches->ckd_cache = NULL; | |
2066 | } | |
2067 | } | |
2068 | } | |
2069 | EXPORT_SYMBOL(lu_kmem_fini); | |
2070 | ||
2071 | /** | |
2072 | * Temporary solution to be able to assign fid in ->do_create() | |
2073 | * till we have fully-functional OST fids | |
2074 | */ | |
2075 | void lu_object_assign_fid(const struct lu_env *env, struct lu_object *o, | |
2076 | const struct lu_fid *fid) | |
2077 | { | |
2078 | struct lu_site *s = o->lo_dev->ld_site; | |
2079 | struct lu_fid *old = &o->lo_header->loh_fid; | |
2080 | struct lu_site_bkt_data *bkt; | |
2081 | struct lu_object *shadow; | |
2082 | wait_queue_t waiter; | |
6da6eabe | 2083 | struct cfs_hash *hs; |
6ea510c1 | 2084 | struct cfs_hash_bd bd; |
d7e09d03 PT |
2085 | __u64 version = 0; |
2086 | ||
2087 | LASSERT(fid_is_zero(old)); | |
2088 | ||
2089 | hs = s->ls_obj_hash; | |
2090 | cfs_hash_bd_get_and_lock(hs, (void *)fid, &bd, 1); | |
2091 | shadow = htable_lookup(s, &bd, fid, &waiter, &version); | |
2092 | /* supposed to be unique */ | |
70b749d4 | 2093 | LASSERT(IS_ERR(shadow) && PTR_ERR(shadow) == -ENOENT); |
d7e09d03 PT |
2094 | *old = *fid; |
2095 | bkt = cfs_hash_bd_extra_get(hs, &bd); | |
2096 | cfs_hash_bd_add_locked(hs, &bd, &o->lo_header->loh_hash); | |
2097 | bkt->lsb_busy++; | |
2098 | cfs_hash_bd_unlock(hs, &bd, 1); | |
2099 | } | |
2100 | EXPORT_SYMBOL(lu_object_assign_fid); | |
2101 | ||
2102 | /** | |
52cf6acf | 2103 | * allocates object with 0 (non-assigned) fid |
d7e09d03 PT |
2104 | * XXX: temporary solution to be able to assign fid in ->do_create() |
2105 | * till we have fully-functional OST fids | |
2106 | */ | |
2107 | struct lu_object *lu_object_anon(const struct lu_env *env, | |
2108 | struct lu_device *dev, | |
2109 | const struct lu_object_conf *conf) | |
2110 | { | |
2111 | struct lu_fid fid; | |
2112 | struct lu_object *o; | |
2113 | ||
2114 | fid_zero(&fid); | |
2115 | o = lu_object_alloc(env, dev, &fid, conf); | |
2116 | ||
2117 | return o; | |
2118 | } | |
2119 | EXPORT_SYMBOL(lu_object_anon); | |
2120 | ||
2121 | struct lu_buf LU_BUF_NULL = { | |
2122 | .lb_buf = NULL, | |
2123 | .lb_len = 0 | |
2124 | }; | |
2125 | EXPORT_SYMBOL(LU_BUF_NULL); | |
2126 | ||
2127 | void lu_buf_free(struct lu_buf *buf) | |
2128 | { | |
2129 | LASSERT(buf); | |
2130 | if (buf->lb_buf) { | |
2131 | LASSERT(buf->lb_len > 0); | |
2132 | OBD_FREE_LARGE(buf->lb_buf, buf->lb_len); | |
2133 | buf->lb_buf = NULL; | |
2134 | buf->lb_len = 0; | |
2135 | } | |
2136 | } | |
2137 | EXPORT_SYMBOL(lu_buf_free); | |
2138 | ||
2139 | void lu_buf_alloc(struct lu_buf *buf, int size) | |
2140 | { | |
2141 | LASSERT(buf); | |
2142 | LASSERT(buf->lb_buf == NULL); | |
2143 | LASSERT(buf->lb_len == 0); | |
2144 | OBD_ALLOC_LARGE(buf->lb_buf, size); | |
2145 | if (likely(buf->lb_buf)) | |
2146 | buf->lb_len = size; | |
2147 | } | |
2148 | EXPORT_SYMBOL(lu_buf_alloc); | |
2149 | ||
2150 | void lu_buf_realloc(struct lu_buf *buf, int size) | |
2151 | { | |
2152 | lu_buf_free(buf); | |
2153 | lu_buf_alloc(buf, size); | |
2154 | } | |
2155 | EXPORT_SYMBOL(lu_buf_realloc); | |
2156 | ||
2157 | struct lu_buf *lu_buf_check_and_alloc(struct lu_buf *buf, int len) | |
2158 | { | |
2159 | if (buf->lb_buf == NULL && buf->lb_len == 0) | |
2160 | lu_buf_alloc(buf, len); | |
2161 | ||
2162 | if ((len > buf->lb_len) && (buf->lb_buf != NULL)) | |
2163 | lu_buf_realloc(buf, len); | |
2164 | ||
2165 | return buf; | |
2166 | } | |
2167 | EXPORT_SYMBOL(lu_buf_check_and_alloc); | |
2168 | ||
2169 | /** | |
2170 | * Increase the size of the \a buf. | |
2171 | * preserves old data in buffer | |
2172 | * old buffer remains unchanged on error | |
2173 | * \retval 0 or -ENOMEM | |
2174 | */ | |
2175 | int lu_buf_check_and_grow(struct lu_buf *buf, int len) | |
2176 | { | |
2177 | char *ptr; | |
2178 | ||
2179 | if (len <= buf->lb_len) | |
2180 | return 0; | |
2181 | ||
2182 | OBD_ALLOC_LARGE(ptr, len); | |
2183 | if (ptr == NULL) | |
2184 | return -ENOMEM; | |
2185 | ||
2186 | /* Free the old buf */ | |
2187 | if (buf->lb_buf != NULL) { | |
2188 | memcpy(ptr, buf->lb_buf, buf->lb_len); | |
2189 | OBD_FREE_LARGE(buf->lb_buf, buf->lb_len); | |
2190 | } | |
2191 | ||
2192 | buf->lb_buf = ptr; | |
2193 | buf->lb_len = len; | |
2194 | return 0; | |
2195 | } | |
2196 | EXPORT_SYMBOL(lu_buf_check_and_grow); |