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LU-1347 style: removes obsolete EXPORT_SYMTAB macros
[fs/lustre-release.git] / lustre / lov / lov_qos.c
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) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
28  * Use is subject to license terms.
29  *
30  * Copyright (c) 2011, 2012, Whamcloud, Inc.
31  */
32 /*
33  * This file is part of Lustre, http://www.lustre.org/
34  * Lustre is a trademark of Sun Microsystems, Inc.
35  */
36
37 #define DEBUG_SUBSYSTEM S_LOV
38
39 #ifdef __KERNEL__
40 #include <libcfs/libcfs.h>
41 #else
42 #include <liblustre.h>
43 #endif
44
45 #include <obd_class.h>
46 #include <obd_lov.h>
47 #include <lustre/lustre_idl.h>
48 #include "lov_internal.h"
49
50 /* #define QOS_DEBUG 1 */
51 #define D_QOS D_OTHER
52
53 #define TGT_BAVAIL(i) (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bavail *\
54                        lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bsize)
55
56
57 int qos_add_tgt(struct obd_device *obd, __u32 index)
58 {
59         struct lov_obd *lov = &obd->u.lov;
60         struct lov_qos_oss *oss, *temposs;
61         struct obd_export *exp = lov->lov_tgts[index]->ltd_exp;
62         int rc = 0, found = 0;
63         ENTRY;
64
65         /* We only need this QOS struct on MDT, not clients - but we may not
66          * have registered the LOV's observer yet, so there's no way to know */
67         if (!exp || !exp->exp_connection) {
68                 CERROR("Missing connection\n");
69                 RETURN(-ENOTCONN);
70         }
71
72         cfs_down_write(&lov->lov_qos.lq_rw_sem);
73         cfs_mutex_lock(&lov->lov_lock);
74         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
75                 if (obd_uuid_equals(&oss->lqo_uuid,
76                                     &exp->exp_connection->c_remote_uuid)) {
77                         found++;
78                         break;
79                 }
80         }
81
82         if (!found) {
83                 OBD_ALLOC_PTR(oss);
84                 if (!oss)
85                         GOTO(out, rc = -ENOMEM);
86                 memcpy(&oss->lqo_uuid,
87                        &exp->exp_connection->c_remote_uuid,
88                        sizeof(oss->lqo_uuid));
89         } else {
90                 /* Assume we have to move this one */
91                 cfs_list_del(&oss->lqo_oss_list);
92         }
93
94         oss->lqo_ost_count++;
95         lov->lov_tgts[index]->ltd_qos.ltq_oss = oss;
96
97         /* Add sorted by # of OSTs.  Find the first entry that we're
98            bigger than... */
99         cfs_list_for_each_entry(temposs, &lov->lov_qos.lq_oss_list,
100                                 lqo_oss_list) {
101                 if (oss->lqo_ost_count > temposs->lqo_ost_count)
102                         break;
103         }
104         /* ...and add before it.  If we're the first or smallest, temposs
105            points to the list head, and we add to the end. */
106         cfs_list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
107
108         lov->lov_qos.lq_dirty = 1;
109         lov->lov_qos.lq_rr.lqr_dirty = 1;
110
111         CDEBUG(D_QOS, "add tgt %s to OSS %s (%d OSTs)\n",
112                obd_uuid2str(&lov->lov_tgts[index]->ltd_uuid),
113                obd_uuid2str(&oss->lqo_uuid),
114                oss->lqo_ost_count);
115
116 out:
117         cfs_mutex_unlock(&lov->lov_lock);
118         cfs_up_write(&lov->lov_qos.lq_rw_sem);
119         RETURN(rc);
120 }
121
122 int qos_del_tgt(struct obd_device *obd, struct lov_tgt_desc *tgt)
123 {
124         struct lov_obd *lov = &obd->u.lov;
125         struct lov_qos_oss *oss;
126         int rc = 0;
127         ENTRY;
128
129         cfs_down_write(&lov->lov_qos.lq_rw_sem);
130
131         oss = tgt->ltd_qos.ltq_oss;
132         if (!oss)
133                 GOTO(out, rc = -ENOENT);
134
135         oss->lqo_ost_count--;
136         if (oss->lqo_ost_count == 0) {
137                 CDEBUG(D_QOS, "removing OSS %s\n",
138                        obd_uuid2str(&oss->lqo_uuid));
139                 cfs_list_del(&oss->lqo_oss_list);
140                 OBD_FREE_PTR(oss);
141         }
142
143         lov->lov_qos.lq_dirty = 1;
144         lov->lov_qos.lq_rr.lqr_dirty = 1;
145 out:
146         cfs_up_write(&lov->lov_qos.lq_rw_sem);
147         RETURN(rc);
148 }
149
150 /* Recalculate per-object penalties for OSSs and OSTs,
151    depends on size of each ost in an oss */
152 static int qos_calc_ppo(struct obd_device *obd)
153 {
154         struct lov_obd *lov = &obd->u.lov;
155         struct lov_qos_oss *oss;
156         __u64 ba_max, ba_min, temp;
157         __u32 num_active;
158         int rc, i, prio_wide;
159         time_t now, age;
160         ENTRY;
161
162         if (!lov->lov_qos.lq_dirty)
163                 GOTO(out, rc = 0);
164
165         num_active = lov->desc.ld_active_tgt_count - 1;
166         if (num_active < 1)
167                 GOTO(out, rc = -EAGAIN);
168
169         /* find bavail on each OSS */
170         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
171                 oss->lqo_bavail = 0;
172         }
173         lov->lov_qos.lq_active_oss_count = 0;
174
175         /* How badly user wants to select osts "widely" (not recently chosen
176            and not on recent oss's).  As opposed to "freely" (free space
177            avail.) 0-256. */
178         prio_wide = 256 - lov->lov_qos.lq_prio_free;
179
180         ba_min = (__u64)(-1);
181         ba_max = 0;
182         now = cfs_time_current_sec();
183         /* Calculate OST penalty per object */
184         /* (lov ref taken in alloc_qos) */
185         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
186                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
187                         continue;
188                 temp = TGT_BAVAIL(i);
189                 if (!temp)
190                         continue;
191                 ba_min = min(temp, ba_min);
192                 ba_max = max(temp, ba_max);
193
194                 /* Count the number of usable OSS's */
195                 if (lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail == 0)
196                         lov->lov_qos.lq_active_oss_count++;
197                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail += temp;
198
199                 /* per-OST penalty is prio * TGT_bavail / (num_ost - 1) / 2 */
200                 temp >>= 1;
201                 lov_do_div64(temp, num_active);
202                 lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj =
203                         (temp * prio_wide) >> 8;
204
205                 age = (now - lov->lov_tgts[i]->ltd_qos.ltq_used) >> 3;
206                 if (lov->lov_qos.lq_reset || age > 32 * lov->desc.ld_qos_maxage)
207                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
208                 else if (age > lov->desc.ld_qos_maxage)
209                         /* Decay the penalty by half for every 8x the update
210                          * interval that the device has been idle.  That gives
211                          * lots of time for the statfs information to be
212                          * updated (which the penalty is only a proxy for),
213                          * and avoids penalizing OSS/OSTs under light load. */
214                         lov->lov_tgts[i]->ltd_qos.ltq_penalty >>=
215                                 (age / lov->desc.ld_qos_maxage);
216         }
217
218         num_active = lov->lov_qos.lq_active_oss_count - 1;
219         if (num_active < 1) {
220                 /* If there's only 1 OSS, we can't penalize it, so instead
221                    we have to double the OST penalty */
222                 num_active = 1;
223                 for (i = 0; i < lov->desc.ld_tgt_count; i++) {
224                         if (lov->lov_tgts[i] == NULL)
225                                 continue;
226                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj <<= 1;
227                 }
228         }
229
230         /* Per-OSS penalty is prio * oss_avail / oss_osts / (num_oss - 1) / 2 */
231         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
232                 temp = oss->lqo_bavail >> 1;
233                 lov_do_div64(temp, oss->lqo_ost_count * num_active);
234                 oss->lqo_penalty_per_obj = (temp * prio_wide) >> 8;
235
236                 age = (now - oss->lqo_used) >> 3;
237                 if (lov->lov_qos.lq_reset || age > 32 * lov->desc.ld_qos_maxage)
238                         oss->lqo_penalty = 0;
239                 else if (age > lov->desc.ld_qos_maxage)
240                         /* Decay the penalty by half for every 8x the update
241                          * interval that the device has been idle.  That gives
242                          * lots of time for the statfs information to be
243                          * updated (which the penalty is only a proxy for),
244                          * and avoids penalizing OSS/OSTs under light load. */
245                         oss->lqo_penalty >>= (age / lov->desc.ld_qos_maxage);
246         }
247
248         lov->lov_qos.lq_dirty = 0;
249         lov->lov_qos.lq_reset = 0;
250
251         /* If each ost has almost same free space,
252          * do rr allocation for better creation performance */
253         lov->lov_qos.lq_same_space = 0;
254         if ((ba_max * (256 - lov->lov_qos.lq_threshold_rr)) >> 8 < ba_min) {
255                 lov->lov_qos.lq_same_space = 1;
256                 /* Reset weights for the next time we enter qos mode */
257                 lov->lov_qos.lq_reset = 1;
258         }
259         rc = 0;
260
261 out:
262         if (!rc && lov->lov_qos.lq_same_space)
263                 RETURN(-EAGAIN);
264         RETURN(rc);
265 }
266
267 static int qos_calc_weight(struct lov_obd *lov, int i)
268 {
269         __u64 temp, temp2;
270
271         /* Final ost weight = TGT_BAVAIL - ost_penalty - oss_penalty */
272         temp = TGT_BAVAIL(i);
273         temp2 = lov->lov_tgts[i]->ltd_qos.ltq_penalty +
274                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty;
275         if (temp < temp2)
276                 lov->lov_tgts[i]->ltd_qos.ltq_weight = 0;
277         else
278                 lov->lov_tgts[i]->ltd_qos.ltq_weight = temp - temp2;
279         return 0;
280 }
281
282 /* We just used this index for a stripe; adjust everyone's weights */
283 static int qos_used(struct lov_obd *lov, struct ost_pool *osts,
284                     __u32 index, __u64 *total_wt)
285 {
286         struct lov_qos_oss *oss;
287         int j;
288         ENTRY;
289
290         /* Don't allocate from this stripe anymore, until the next alloc_qos */
291         lov->lov_tgts[index]->ltd_qos.ltq_usable = 0;
292
293         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
294
295         /* Decay old penalty by half (we're adding max penalty, and don't
296            want it to run away.) */
297         lov->lov_tgts[index]->ltd_qos.ltq_penalty >>= 1;
298         oss->lqo_penalty >>= 1;
299
300         /* mark the OSS and OST as recently used */
301         lov->lov_tgts[index]->ltd_qos.ltq_used =
302                 oss->lqo_used = cfs_time_current_sec();
303
304         /* Set max penalties for this OST and OSS */
305         lov->lov_tgts[index]->ltd_qos.ltq_penalty +=
306                 lov->lov_tgts[index]->ltd_qos.ltq_penalty_per_obj *
307                 lov->desc.ld_active_tgt_count;
308         oss->lqo_penalty += oss->lqo_penalty_per_obj *
309                 lov->lov_qos.lq_active_oss_count;
310
311         /* Decrease all OSS penalties */
312         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
313                 if (oss->lqo_penalty < oss->lqo_penalty_per_obj)
314                         oss->lqo_penalty = 0;
315                 else
316                         oss->lqo_penalty -= oss->lqo_penalty_per_obj;
317         }
318
319         *total_wt = 0;
320         /* Decrease all OST penalties */
321         for (j = 0; j < osts->op_count; j++) {
322                 int i;
323
324                 i = osts->op_array[j];
325                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
326                         continue;
327                 if (lov->lov_tgts[i]->ltd_qos.ltq_penalty <
328                     lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj)
329                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
330                 else
331                         lov->lov_tgts[i]->ltd_qos.ltq_penalty -=
332                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj;
333
334                 qos_calc_weight(lov, i);
335
336                 /* Recalc the total weight of usable osts */
337                 if (lov->lov_tgts[i]->ltd_qos.ltq_usable)
338                         *total_wt += lov->lov_tgts[i]->ltd_qos.ltq_weight;
339
340 #ifdef QOS_DEBUG
341                 CDEBUG(D_QOS, "recalc tgt %d usable=%d avail="LPU64
342                        " ostppo="LPU64" ostp="LPU64" ossppo="LPU64
343                        " ossp="LPU64" wt="LPU64"\n",
344                        i, lov->lov_tgts[i]->ltd_qos.ltq_usable,
345                        TGT_BAVAIL(i) >> 10,
346                        lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj >> 10,
347                        lov->lov_tgts[i]->ltd_qos.ltq_penalty >> 10,
348                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty_per_obj>>10,
349                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty >> 10,
350                        lov->lov_tgts[i]->ltd_qos.ltq_weight >> 10);
351 #endif
352         }
353
354         RETURN(0);
355 }
356
357 #define LOV_QOS_EMPTY ((__u32)-1)
358 /* compute optimal round-robin order, based on OSTs per OSS */
359 static int qos_calc_rr(struct lov_obd *lov, struct ost_pool *src_pool,
360                        struct lov_qos_rr *lqr)
361 {
362         struct lov_qos_oss *oss;
363         unsigned placed, real_count;
364         int i, rc;
365         ENTRY;
366
367         if (!lqr->lqr_dirty) {
368                 LASSERT(lqr->lqr_pool.op_size);
369                 RETURN(0);
370         }
371
372         /* Do actual allocation. */
373         cfs_down_write(&lov->lov_qos.lq_rw_sem);
374
375         /*
376          * Check again. While we were sleeping on @lq_rw_sem something could
377          * change.
378          */
379         if (!lqr->lqr_dirty) {
380                 LASSERT(lqr->lqr_pool.op_size);
381                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
382                 RETURN(0);
383         }
384
385         real_count = src_pool->op_count;
386
387         /* Zero the pool array */
388         /* alloc_rr is holding a read lock on the pool, so nobody is adding/
389            deleting from the pool. The lq_rw_sem insures that nobody else
390            is reading. */
391         lqr->lqr_pool.op_count = real_count;
392         rc = lov_ost_pool_extend(&lqr->lqr_pool, real_count);
393         if (rc) {
394                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
395                 RETURN(rc);
396         }
397         for (i = 0; i < lqr->lqr_pool.op_count; i++)
398                 lqr->lqr_pool.op_array[i] = LOV_QOS_EMPTY;
399
400         /* Place all the OSTs from 1 OSS at the same time. */
401         placed = 0;
402         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
403                 int j = 0;
404                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
405                         if (lov->lov_tgts[src_pool->op_array[i]] &&
406                             (lov->lov_tgts[src_pool->op_array[i]]->ltd_qos.ltq_oss == oss)) {
407                               /* Evenly space these OSTs across arrayspace */
408                               int next = j * lqr->lqr_pool.op_count / oss->lqo_ost_count;
409                               while (lqr->lqr_pool.op_array[next] !=
410                                      LOV_QOS_EMPTY)
411                                         next = (next + 1) % lqr->lqr_pool.op_count;
412                               lqr->lqr_pool.op_array[next] = src_pool->op_array[i];
413                               j++;
414                               placed++;
415                         }
416                 }
417         }
418
419         lqr->lqr_dirty = 0;
420         cfs_up_write(&lov->lov_qos.lq_rw_sem);
421
422         if (placed != real_count) {
423                 /* This should never happen */
424                 LCONSOLE_ERROR_MSG(0x14e, "Failed to place all OSTs in the "
425                                    "round-robin list (%d of %d).\n",
426                                    placed, real_count);
427                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
428                         LCONSOLE(D_WARNING, "rr #%d ost idx=%d\n", i,
429                                  lqr->lqr_pool.op_array[i]);
430                 }
431                 lqr->lqr_dirty = 1;
432                 RETURN(-EAGAIN);
433         }
434
435 #ifdef QOS_DEBUG
436         for (i = 0; i < lqr->lqr_pool.op_count; i++) {
437                 LCONSOLE(D_QOS, "rr #%d ost idx=%d\n", i,
438                          lqr->lqr_pool.op_array[i]);
439         }
440 #endif
441
442         RETURN(0);
443 }
444
445
446 void qos_shrink_lsm(struct lov_request_set *set)
447 {
448         struct lov_stripe_md *lsm = set->set_oi->oi_md, *lsm_new;
449         /* XXX LOV STACKING call into osc for sizes */
450         unsigned oldsize, newsize;
451
452         if (set->set_oti && set->set_cookies && set->set_cookie_sent) {
453                 struct llog_cookie *cookies;
454                 oldsize = lsm->lsm_stripe_count * sizeof(*cookies);
455                 newsize = set->set_count * sizeof(*cookies);
456
457                 cookies = set->set_cookies;
458                 oti_alloc_cookies(set->set_oti, set->set_count);
459                 if (set->set_oti->oti_logcookies) {
460                         memcpy(set->set_oti->oti_logcookies, cookies, newsize);
461                         OBD_FREE_LARGE(cookies, oldsize);
462                         set->set_cookies = set->set_oti->oti_logcookies;
463                 } else {
464                         CWARN("'leaking' %d bytes\n", oldsize - newsize);
465                 }
466         }
467
468         CWARN("using fewer stripes for object "LPU64": old %u new %u\n",
469               lsm->lsm_object_id, lsm->lsm_stripe_count, set->set_count);
470         LASSERT(lsm->lsm_stripe_count >= set->set_count);
471
472         newsize = lov_stripe_md_size(set->set_count);
473         OBD_ALLOC_LARGE(lsm_new, newsize);
474         if (lsm_new != NULL) {
475                 int i;
476                 memcpy(lsm_new, lsm, sizeof(*lsm));
477                 for (i = 0; i < lsm->lsm_stripe_count; i++) {
478                         if (i < set->set_count) {
479                                 lsm_new->lsm_oinfo[i] = lsm->lsm_oinfo[i];
480                                 continue;
481                         }
482                         OBD_SLAB_FREE(lsm->lsm_oinfo[i], lov_oinfo_slab,
483                                       sizeof(struct lov_oinfo));
484                 }
485                 lsm_new->lsm_stripe_count = set->set_count;
486                 OBD_FREE_LARGE(lsm, sizeof(struct lov_stripe_md) +
487                                lsm->lsm_stripe_count*sizeof(struct lov_oinfo*));
488                 set->set_oi->oi_md = lsm_new;
489         } else {
490                 CWARN("'leaking' few bytes\n");
491         }
492 }
493
494 /**
495  * Check whether we can create the object on the OST(refered by ost_idx)
496  * \retval:
497  *          0: create the object.
498  *          other value: did not create the object.
499  */
500 static int lov_check_and_create_object(struct lov_obd *lov, int ost_idx,
501                                        struct lov_stripe_md *lsm,
502                                        struct lov_request *req,
503                                        struct obd_trans_info *oti)
504 {
505         __u16 stripe;
506         int rc = -EIO;
507         ENTRY;
508
509         CDEBUG(D_QOS, "Check and create on idx %d \n", ost_idx);
510         if (!lov->lov_tgts[ost_idx] ||
511             !lov->lov_tgts[ost_idx]->ltd_active)
512                 RETURN(rc);
513
514         /* check if objects has been created on this ost */
515         for (stripe = 0; stripe < lsm->lsm_stripe_count; stripe++) {
516                 /* already have object at this stripe */
517                 if (ost_idx == lsm->lsm_oinfo[stripe]->loi_ost_idx)
518                         break;
519         }
520
521         if (stripe >= lsm->lsm_stripe_count) {
522                 req->rq_idx = ost_idx;
523                 rc = obd_create(NULL, lov->lov_tgts[ost_idx]->ltd_exp,
524                                 req->rq_oi.oi_oa, &req->rq_oi.oi_md,
525                                 oti);
526         }
527         RETURN(rc);
528 }
529
530 int qos_remedy_create(struct lov_request_set *set, struct lov_request *req)
531 {
532         struct lov_stripe_md *lsm = set->set_oi->oi_md;
533         struct lov_obd *lov = &set->set_exp->exp_obd->u.lov;
534         unsigned ost_idx = 0, ost_count;
535         struct pool_desc *pool;
536         struct ost_pool *osts = NULL;
537         int i, rc = -EIO;
538         ENTRY;
539
540         /* First check whether we can create the objects on the pool */
541         pool = lov_find_pool(lov, lsm->lsm_pool_name);
542         if (pool != NULL) {
543                 cfs_down_read(&pool_tgt_rw_sem(pool));
544                 osts = &(pool->pool_obds);
545                 ost_count = osts->op_count;
546                 for (i = 0; i < ost_count; i++, ost_idx = osts->op_array[i]) {
547                         rc = lov_check_and_create_object(lov, ost_idx, lsm, req,
548                                                          set->set_oti);
549                         if (rc == 0)
550                                 break;
551                 }
552                 cfs_up_read(&pool_tgt_rw_sem(pool));
553                 lov_pool_putref(pool);
554                 RETURN(rc);
555         }
556
557         ost_count = lov->desc.ld_tgt_count;
558         /* Then check whether we can create the objects on other OSTs */
559         ost_idx = (req->rq_idx + lsm->lsm_stripe_count) % ost_count;
560         for (i = 0; i < ost_count; i++, ost_idx = (ost_idx + 1) % ost_count) {
561                 rc = lov_check_and_create_object(lov, ost_idx, lsm, req,
562                                                  set->set_oti);
563
564                 if (rc == 0)
565                         break;
566         }
567
568         RETURN(rc);
569 }
570
571 static int min_stripe_count(int stripe_cnt, int flags)
572 {
573         return (flags & LOV_USES_DEFAULT_STRIPE ?
574                 stripe_cnt - (stripe_cnt / 4) : stripe_cnt);
575 }
576
577 #define LOV_CREATE_RESEED_MULT 30
578 #define LOV_CREATE_RESEED_MIN  2000
579 /* Allocate objects on osts with round-robin algorithm */
580 static int alloc_rr(struct lov_obd *lov, int *idx_arr, int *stripe_cnt,
581                     char *poolname, int flags)
582 {
583         unsigned array_idx;
584         int i, rc, *idx_pos;
585         __u32 ost_idx;
586         int ost_start_idx_temp;
587         int speed = 0;
588         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
589         struct pool_desc *pool;
590         struct ost_pool *osts;
591         struct lov_qos_rr *lqr;
592         ENTRY;
593
594         pool = lov_find_pool(lov, poolname);
595         if (pool == NULL) {
596                 osts = &(lov->lov_packed);
597                 lqr = &(lov->lov_qos.lq_rr);
598         } else {
599                 cfs_down_read(&pool_tgt_rw_sem(pool));
600                 osts = &(pool->pool_obds);
601                 lqr = &(pool->pool_rr);
602         }
603
604         rc = qos_calc_rr(lov, osts, lqr);
605         if (rc)
606                 GOTO(out, rc);
607
608         if (--lqr->lqr_start_count <= 0) {
609                 lqr->lqr_start_idx = cfs_rand() % osts->op_count;
610                 lqr->lqr_start_count =
611                         (LOV_CREATE_RESEED_MIN / max(osts->op_count, 1U) +
612                          LOV_CREATE_RESEED_MULT) * max(osts->op_count, 1U);
613         } else if (stripe_cnt_min >= osts->op_count ||
614                    lqr->lqr_start_idx > osts->op_count) {
615                 /* If we have allocated from all of the OSTs, slowly
616                  * precess the next start if the OST/stripe count isn't
617                  * already doing this for us. */
618                 lqr->lqr_start_idx %= osts->op_count;
619                 if (*stripe_cnt > 1 && (osts->op_count % (*stripe_cnt)) != 1)
620                         ++lqr->lqr_offset_idx;
621         }
622         cfs_down_read(&lov->lov_qos.lq_rw_sem);
623         ost_start_idx_temp = lqr->lqr_start_idx;
624
625 repeat_find:
626         array_idx = (lqr->lqr_start_idx + lqr->lqr_offset_idx) % osts->op_count;
627         idx_pos = idx_arr;
628 #ifdef QOS_DEBUG
629         CDEBUG(D_QOS, "pool '%s' want %d startidx %d startcnt %d offset %d "
630                "active %d count %d arrayidx %d\n", poolname,
631                *stripe_cnt, lqr->lqr_start_idx, lqr->lqr_start_count,
632                lqr->lqr_offset_idx, osts->op_count, osts->op_count, array_idx);
633 #endif
634
635         for (i = 0; i < osts->op_count;
636                     i++, array_idx=(array_idx + 1) % osts->op_count) {
637                 ++lqr->lqr_start_idx;
638                 ost_idx = lqr->lqr_pool.op_array[array_idx];
639 #ifdef QOS_DEBUG
640                 CDEBUG(D_QOS, "#%d strt %d act %d strp %d ary %d idx %d\n",
641                        i, lqr->lqr_start_idx,
642                        ((ost_idx != LOV_QOS_EMPTY) && lov->lov_tgts[ost_idx]) ?
643                        lov->lov_tgts[ost_idx]->ltd_active : 0,
644                        idx_pos - idx_arr, array_idx, ost_idx);
645 #endif
646                 if ((ost_idx == LOV_QOS_EMPTY) || !lov->lov_tgts[ost_idx] ||
647                     !lov->lov_tgts[ost_idx]->ltd_active)
648                         continue;
649
650                 /* Fail Check before osc_precreate() is called
651                    so we can only 'fail' single OSC. */
652                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
653                         continue;
654
655                 /* Drop slow OSCs if we can */
656                 if (obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed)
657                         continue;
658
659                 *idx_pos = ost_idx;
660                 idx_pos++;
661                 /* We have enough stripes */
662                 if (idx_pos - idx_arr == *stripe_cnt)
663                         break;
664         }
665         if ((speed < 2) && (idx_pos - idx_arr < stripe_cnt_min)) {
666                 /* Try again, allowing slower OSCs */
667                 speed++;
668                 lqr->lqr_start_idx = ost_start_idx_temp;
669                 goto repeat_find;
670         }
671
672         cfs_up_read(&lov->lov_qos.lq_rw_sem);
673
674         *stripe_cnt = idx_pos - idx_arr;
675 out:
676         if (pool != NULL) {
677                 cfs_up_read(&pool_tgt_rw_sem(pool));
678                 /* put back ref got by lov_find_pool() */
679                 lov_pool_putref(pool);
680         }
681
682         RETURN(rc);
683 }
684
685 /* alloc objects on osts with specific stripe offset */
686 static int alloc_specific(struct lov_obd *lov, struct lov_stripe_md *lsm,
687                           int *idx_arr)
688 {
689         unsigned ost_idx, array_idx, ost_count;
690         int i, rc, *idx_pos;
691         int speed = 0;
692         struct pool_desc *pool;
693         struct ost_pool *osts;
694         ENTRY;
695
696         pool = lov_find_pool(lov, lsm->lsm_pool_name);
697         if (pool == NULL) {
698                 osts = &(lov->lov_packed);
699         } else {
700                 cfs_down_read(&pool_tgt_rw_sem(pool));
701                 osts = &(pool->pool_obds);
702         }
703
704         ost_count = osts->op_count;
705
706 repeat_find:
707         /* search loi_ost_idx in ost array */
708         array_idx = 0;
709         for (i = 0; i < ost_count; i++) {
710                 if (osts->op_array[i] == lsm->lsm_oinfo[0]->loi_ost_idx) {
711                         array_idx = i;
712                         break;
713                 }
714         }
715         if (i == ost_count) {
716                 CERROR("Start index %d not found in pool '%s'\n",
717                        lsm->lsm_oinfo[0]->loi_ost_idx, lsm->lsm_pool_name);
718                 GOTO(out, rc = -EINVAL);
719         }
720
721         idx_pos = idx_arr;
722         for (i = 0; i < ost_count;
723              i++, array_idx = (array_idx + 1) % ost_count) {
724                 ost_idx = osts->op_array[array_idx];
725
726                 if (!lov->lov_tgts[ost_idx] ||
727                     !lov->lov_tgts[ost_idx]->ltd_active) {
728                         continue;
729                 }
730
731                 /* Fail Check before osc_precreate() is called
732                    so we can only 'fail' single OSC. */
733                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
734                         continue;
735
736                 /* Drop slow OSCs if we can, but not for requested start idx.
737                  *
738                  * This means "if OSC is slow and it is not the requested
739                  * start OST, then it can be skipped, otherwise skip it only
740                  * if it is inactive/recovering/out-of-space." */
741                 if ((obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed) &&
742                     (i != 0 || speed >= 2))
743                         continue;
744
745                 *idx_pos = ost_idx;
746                 idx_pos++;
747                 /* We have enough stripes */
748                 if (idx_pos - idx_arr == lsm->lsm_stripe_count)
749                         GOTO(out, rc = 0);
750         }
751         if (speed < 2) {
752                 /* Try again, allowing slower OSCs */
753                 speed++;
754                 goto repeat_find;
755         }
756
757         /* If we were passed specific striping params, then a failure to
758          * meet those requirements is an error, since we can't reallocate
759          * that memory (it might be part of a larger array or something).
760          *
761          * We can only get here if lsm_stripe_count was originally > 1.
762          */
763         CERROR("can't lstripe objid "LPX64": have %d want %u\n",
764                lsm->lsm_object_id, (int)(idx_pos - idx_arr),
765                lsm->lsm_stripe_count);
766         rc = -EFBIG;
767 out:
768         if (pool != NULL) {
769                 cfs_up_read(&pool_tgt_rw_sem(pool));
770                 /* put back ref got by lov_find_pool() */
771                 lov_pool_putref(pool);
772         }
773
774         RETURN(rc);
775 }
776
777 /* Alloc objects on osts with optimization based on:
778    - free space
779    - network resources (shared OSS's)
780 */
781 static int alloc_qos(struct obd_export *exp, int *idx_arr, int *stripe_cnt,
782                      char *poolname, int flags)
783 {
784         struct lov_obd *lov = &exp->exp_obd->u.lov;
785         __u64 total_weight = 0;
786         int nfound, good_osts, i, rc = 0;
787         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
788         struct pool_desc *pool;
789         struct ost_pool *osts;
790         ENTRY;
791
792         if (stripe_cnt_min < 1)
793                 RETURN(-EINVAL);
794
795         pool = lov_find_pool(lov, poolname);
796         if (pool == NULL) {
797                 osts = &(lov->lov_packed);
798         } else {
799                 cfs_down_read(&pool_tgt_rw_sem(pool));
800                 osts = &(pool->pool_obds);
801         }
802
803         obd_getref(exp->exp_obd);
804
805         /* wait for fresh statfs info if needed, the rpcs are sent in
806          * lov_create() */
807         qos_statfs_update(exp->exp_obd,
808                           cfs_time_shift_64(-2 * lov->desc.ld_qos_maxage), 1);
809
810         /* Detect -EAGAIN early, before expensive lock is taken. */
811         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
812                 GOTO(out_nolock, rc = -EAGAIN);
813
814         /* Do actual allocation, use write lock here. */
815         cfs_down_write(&lov->lov_qos.lq_rw_sem);
816
817         /*
818          * Check again, while we were sleeping on @lq_rw_sem things could
819          * change.
820          */
821         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
822                 GOTO(out, rc = -EAGAIN);
823
824         if (lov->desc.ld_active_tgt_count < 2)
825                 GOTO(out, rc = -EAGAIN);
826
827         rc = qos_calc_ppo(exp->exp_obd);
828         if (rc)
829                 GOTO(out, rc);
830
831         good_osts = 0;
832         /* Find all the OSTs that are valid stripe candidates */
833         for (i = 0; i < osts->op_count; i++) {
834                 if (!lov->lov_tgts[osts->op_array[i]] ||
835                     !lov->lov_tgts[osts->op_array[i]]->ltd_active)
836                         continue;
837
838                 /* Fail Check before osc_precreate() is called
839                    so we can only 'fail' single OSC. */
840                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && osts->op_array[i] == 0)
841                         continue;
842
843                 if (obd_precreate(lov->lov_tgts[osts->op_array[i]]->ltd_exp) > 2)
844                         continue;
845
846                 lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable = 1;
847                 qos_calc_weight(lov, osts->op_array[i]);
848                 total_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
849
850                 good_osts++;
851         }
852
853 #ifdef QOS_DEBUG
854         CDEBUG(D_QOS, "found %d good osts\n", good_osts);
855 #endif
856
857         if (good_osts < stripe_cnt_min)
858                 GOTO(out, rc = -EAGAIN);
859
860         /* We have enough osts */
861         if (good_osts < *stripe_cnt)
862                 *stripe_cnt = good_osts;
863
864         if (!*stripe_cnt)
865                 GOTO(out, rc = -EAGAIN);
866
867         /* Find enough OSTs with weighted random allocation. */
868         nfound = 0;
869         while (nfound < *stripe_cnt) {
870                 __u64 rand, cur_weight;
871
872                 cur_weight = 0;
873                 rc = -ENODEV;
874
875                 if (total_weight) {
876 #if BITS_PER_LONG == 32
877                         rand = cfs_rand() % (unsigned)total_weight;
878                         /* If total_weight > 32-bit, first generate the high
879                          * 32 bits of the random number, then add in the low
880                          * 32 bits (truncated to the upper limit, if needed) */
881                         if (total_weight > 0xffffffffULL)
882                                 rand = (__u64)(cfs_rand() %
883                                           (unsigned)(total_weight >> 32)) << 32;
884                         else
885                                 rand = 0;
886
887                         if (rand == (total_weight & 0xffffffff00000000ULL))
888                                 rand |= cfs_rand() % (unsigned)total_weight;
889                         else
890                                 rand |= cfs_rand();
891
892 #else
893                         rand = ((__u64)cfs_rand() << 32 | cfs_rand()) %
894                                 total_weight;
895 #endif
896                 } else {
897                         rand = 0;
898                 }
899
900                 /* On average, this will hit larger-weighted osts more often.
901                    0-weight osts will always get used last (only when rand=0).*/
902                 for (i = 0; i < osts->op_count; i++) {
903                         if (!lov->lov_tgts[osts->op_array[i]] ||
904                             !lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable)
905                                 continue;
906
907                         cur_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
908 #ifdef QOS_DEBUG
909                         CDEBUG(D_QOS, "stripe_cnt=%d nfound=%d cur_weight="LPU64
910                                       " rand="LPU64" total_weight="LPU64"\n",
911                                *stripe_cnt, nfound, cur_weight, rand, total_weight);
912 #endif
913                         if (cur_weight >= rand) {
914 #ifdef QOS_DEBUG
915                                 CDEBUG(D_QOS, "assigned stripe=%d to idx=%d\n",
916                                        nfound, osts->op_array[i]);
917 #endif
918                                 idx_arr[nfound++] = osts->op_array[i];
919                                 qos_used(lov, osts, osts->op_array[i], &total_weight);
920                                 rc = 0;
921                                 break;
922                         }
923                 }
924                 /* should never satisfy below condition */
925                 if (rc) {
926                         CERROR("Didn't find any OSTs?\n");
927                         break;
928                 }
929         }
930         LASSERT(nfound == *stripe_cnt);
931
932 out:
933         cfs_up_write(&lov->lov_qos.lq_rw_sem);
934
935 out_nolock:
936         if (pool != NULL) {
937                 cfs_up_read(&pool_tgt_rw_sem(pool));
938                 /* put back ref got by lov_find_pool() */
939                 lov_pool_putref(pool);
940         }
941
942         if (rc == -EAGAIN)
943                 rc = alloc_rr(lov, idx_arr, stripe_cnt, poolname, flags);
944
945         obd_putref(exp->exp_obd);
946         RETURN(rc);
947 }
948
949 /* return new alloced stripe count on success */
950 static int alloc_idx_array(struct obd_export *exp, struct lov_stripe_md *lsm,
951                            int newea, int **idx_arr, int *arr_cnt, int flags)
952 {
953         struct lov_obd *lov = &exp->exp_obd->u.lov;
954         int stripe_cnt = lsm->lsm_stripe_count;
955         int i, rc = 0;
956         int *tmp_arr = NULL;
957         ENTRY;
958
959         *arr_cnt = stripe_cnt;
960         OBD_ALLOC(tmp_arr, *arr_cnt * sizeof(int));
961         if (tmp_arr == NULL)
962                 RETURN(-ENOMEM);
963         for (i = 0; i < *arr_cnt; i++)
964                 tmp_arr[i] = -1;
965
966         if (newea ||
967             lsm->lsm_oinfo[0]->loi_ost_idx >= lov->desc.ld_tgt_count)
968                 rc = alloc_qos(exp, tmp_arr, &stripe_cnt,
969                                lsm->lsm_pool_name, flags);
970         else
971                 rc = alloc_specific(lov, lsm, tmp_arr);
972
973         if (rc)
974                 GOTO(out_arr, rc);
975
976         *idx_arr = tmp_arr;
977         RETURN(stripe_cnt);
978 out_arr:
979         OBD_FREE(tmp_arr, *arr_cnt * sizeof(int));
980         *arr_cnt = 0;
981         RETURN(rc);
982 }
983
984 static void free_idx_array(int *idx_arr, int arr_cnt)
985 {
986         if (arr_cnt)
987                 OBD_FREE(idx_arr, arr_cnt * sizeof(int));
988 }
989
990 int qos_prep_create(struct obd_export *exp, struct lov_request_set *set)
991 {
992         struct lov_obd *lov = &exp->exp_obd->u.lov;
993         struct lov_stripe_md *lsm;
994         struct obdo *src_oa = set->set_oi->oi_oa;
995         struct obd_trans_info *oti = set->set_oti;
996         int i, stripes, rc = 0, newea = 0;
997         int flag = LOV_USES_ASSIGNED_STRIPE;
998         int *idx_arr = NULL, idx_cnt = 0;
999         ENTRY;
1000
1001         LASSERT(src_oa->o_valid & OBD_MD_FLID);
1002         LASSERT(src_oa->o_valid & OBD_MD_FLGROUP);
1003
1004         if (set->set_oi->oi_md == NULL) {
1005                 __u16 stripes_def = lov_get_stripecnt(lov, LOV_MAGIC, 0);
1006
1007                 /* If the MDS file was truncated up to some size, stripe over
1008                  * enough OSTs to allow the file to be created at that size.
1009                  * This may mean we use more than the default # of stripes. */
1010                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
1011                         obd_size min_bavail = LUSTRE_STRIPE_MAXBYTES;
1012
1013                         /* Find a small number of stripes we can use
1014                            (up to # of active osts). */
1015                         stripes = 1;
1016                         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
1017                                 if (!lov->lov_tgts[i] ||
1018                                     !lov->lov_tgts[i]->ltd_active)
1019                                         continue;
1020                                 min_bavail = min(min_bavail, TGT_BAVAIL(i));
1021                                 if (min_bavail * stripes > src_oa->o_size)
1022                                         break;
1023                                 stripes++;
1024                         }
1025
1026                         if (stripes < stripes_def)
1027                                 stripes = stripes_def;
1028                 } else {
1029                         flag = LOV_USES_DEFAULT_STRIPE;
1030                         stripes = stripes_def;
1031                 }
1032
1033                 rc = lov_alloc_memmd(&set->set_oi->oi_md, stripes,
1034                                      lov->desc.ld_pattern ?
1035                                      lov->desc.ld_pattern : LOV_PATTERN_RAID0,
1036                                      LOV_MAGIC);
1037                 if (rc < 0)
1038                         GOTO(out_err, rc);
1039                 newea = 1;
1040                 rc = 0;
1041         }
1042
1043         lsm = set->set_oi->oi_md;
1044         lsm->lsm_object_id = src_oa->o_id;
1045         lsm->lsm_object_seq = src_oa->o_seq;
1046         lsm->lsm_layout_gen = 0; /* actual generation set in mdd_lov_create() */
1047
1048         if (!lsm->lsm_stripe_size)
1049                 lsm->lsm_stripe_size = lov->desc.ld_default_stripe_size;
1050         if (!lsm->lsm_pattern) {
1051                 LASSERT(lov->desc.ld_pattern);
1052                 lsm->lsm_pattern = lov->desc.ld_pattern;
1053         }
1054
1055         stripes = alloc_idx_array(exp, lsm, newea, &idx_arr, &idx_cnt, flag);
1056         if (stripes <= 0)
1057                 GOTO(out_err, rc = stripes ? stripes : -EIO);
1058         LASSERTF(stripes <= lsm->lsm_stripe_count,"requested %d allocated %d\n",
1059                  lsm->lsm_stripe_count, stripes);
1060
1061         for (i = 0; i < stripes; i++) {
1062                 struct lov_request *req;
1063                 int ost_idx = idx_arr[i];
1064                 LASSERT(ost_idx >= 0);
1065
1066                 OBD_ALLOC(req, sizeof(*req));
1067                 if (req == NULL)
1068                         GOTO(out_err, rc = -ENOMEM);
1069                 lov_set_add_req(req, set);
1070
1071                 req->rq_buflen = sizeof(*req->rq_oi.oi_md);
1072                 OBD_ALLOC_LARGE(req->rq_oi.oi_md, req->rq_buflen);
1073                 if (req->rq_oi.oi_md == NULL)
1074                         GOTO(out_err, rc = -ENOMEM);
1075
1076                 OBDO_ALLOC(req->rq_oi.oi_oa);
1077                 if (req->rq_oi.oi_oa == NULL)
1078                         GOTO(out_err, rc = -ENOMEM);
1079
1080                 req->rq_idx = ost_idx;
1081                 req->rq_stripe = i;
1082                 /* create data objects with "parent" OA */
1083                 memcpy(req->rq_oi.oi_oa, src_oa, sizeof(*req->rq_oi.oi_oa));
1084                 req->rq_oi.oi_cb_up = cb_create_update;
1085
1086                 /* XXX When we start creating objects on demand, we need to
1087                  *     make sure that we always create the object on the
1088                  *     stripe which holds the existing file size.
1089                  */
1090                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
1091                         req->rq_oi.oi_oa->o_size =
1092                                 lov_size_to_stripe(lsm, src_oa->o_size, i);
1093
1094                         CDEBUG(D_INODE, "stripe %d has size "LPU64"/"LPU64"\n",
1095                                i, req->rq_oi.oi_oa->o_size, src_oa->o_size);
1096                 }
1097         }
1098         LASSERT(set->set_count == stripes);
1099
1100         if (stripes < lsm->lsm_stripe_count)
1101                 qos_shrink_lsm(set);
1102         if (OBD_FAIL_CHECK(OBD_FAIL_MDS_LOV_PREP_CREATE)) {
1103                 qos_shrink_lsm(set);
1104                 rc = -EIO;
1105         }
1106
1107         if (oti && (src_oa->o_valid & OBD_MD_FLCOOKIE)) {
1108                 oti_alloc_cookies(oti, set->set_count);
1109                 if (!oti->oti_logcookies)
1110                         GOTO(out_err, rc = -ENOMEM);
1111                 set->set_cookies = oti->oti_logcookies;
1112         }
1113 out_err:
1114         if (newea && rc)
1115                 obd_free_memmd(exp, &set->set_oi->oi_md);
1116         if (idx_arr)
1117                 free_idx_array(idx_arr, idx_cnt);
1118         EXIT;
1119         return rc;
1120 }
1121
1122 void qos_update(struct lov_obd *lov)
1123 {
1124         ENTRY;
1125         lov->lov_qos.lq_dirty = 1;
1126 }
1127
1128 void qos_statfs_done(struct lov_obd *lov)
1129 {
1130         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1131         if (lov->lov_qos.lq_statfs_in_progress) {
1132                 lov->lov_qos.lq_statfs_in_progress = 0;
1133                 /* wake up any threads waiting for the statfs rpcs to complete*/
1134                 cfs_waitq_signal(&lov->lov_qos.lq_statfs_waitq);
1135         }
1136         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1137 }
1138
1139 static int qos_statfs_ready(struct obd_device *obd, __u64 max_age)
1140 {
1141         struct lov_obd         *lov = &obd->u.lov;
1142         int rc;
1143         ENTRY;
1144         cfs_down_read(&lov->lov_qos.lq_rw_sem);
1145         rc = lov->lov_qos.lq_statfs_in_progress == 0 ||
1146              cfs_time_beforeq_64(max_age, obd->obd_osfs_age);
1147         cfs_up_read(&lov->lov_qos.lq_rw_sem);
1148         RETURN(rc);
1149 }
1150
1151 /*
1152  * Update statfs data if the current osfs age is older than max_age.
1153  * If wait is not set, it means that we are called from lov_create()
1154  * and we should just issue the rpcs without waiting for them to complete.
1155  * If wait is set, we are called from alloc_qos() and we just have
1156  * to wait for the request set to complete.
1157  */
1158 void qos_statfs_update(struct obd_device *obd, __u64 max_age, int wait)
1159 {
1160         struct lov_obd         *lov = &obd->u.lov;
1161         struct obd_info        *oinfo;
1162         int                     rc = 0;
1163         struct ptlrpc_request_set *set = NULL;
1164         ENTRY;
1165
1166         if (cfs_time_beforeq_64(max_age, obd->obd_osfs_age))
1167                 /* statfs data are quite recent, don't need to refresh it */
1168                 RETURN_EXIT;
1169
1170         if (!wait && lov->lov_qos.lq_statfs_in_progress)
1171                 /* statfs already in progress */
1172                 RETURN_EXIT;
1173
1174         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1175         if (lov->lov_qos.lq_statfs_in_progress) {
1176                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
1177                 GOTO(out, rc = 0);
1178         }
1179         /* no statfs in flight, send rpcs */
1180         lov->lov_qos.lq_statfs_in_progress = 1;
1181         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1182
1183         if (wait)
1184                 CDEBUG(D_QOS, "%s: did not manage to get fresh statfs data "
1185                        "in a timely manner (osfs age "LPU64", max age "LPU64")"
1186                        ", sending new statfs rpcs\n",
1187                        obd_uuid2str(&lov->desc.ld_uuid), obd->obd_osfs_age,
1188                        max_age);
1189
1190         /* need to send statfs rpcs */
1191         CDEBUG(D_QOS, "sending new statfs requests\n");
1192         memset(lov->lov_qos.lq_statfs_data, 0,
1193                sizeof(*lov->lov_qos.lq_statfs_data));
1194         oinfo = &lov->lov_qos.lq_statfs_data->lsd_oi;
1195         oinfo->oi_osfs = &lov->lov_qos.lq_statfs_data->lsd_statfs;
1196         oinfo->oi_flags = OBD_STATFS_NODELAY;
1197         set = ptlrpc_prep_set();
1198         if (!set)
1199                 GOTO(out_failed, rc = -ENOMEM);
1200
1201         rc = obd_statfs_async(obd->obd_self_export, oinfo, max_age, set);
1202         if (rc || cfs_list_empty(&set->set_requests)) {
1203                 if (rc)
1204                         CWARN("statfs failed with %d\n", rc);
1205                 GOTO(out_failed, rc);
1206         }
1207         /* send requests via ptlrpcd */
1208         oinfo->oi_flags |= OBD_STATFS_PTLRPCD;
1209         ptlrpcd_add_rqset(set);
1210         GOTO(out, rc);
1211
1212 out_failed:
1213         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1214         lov->lov_qos.lq_statfs_in_progress = 0;
1215         /* wake up any threads waiting for the statfs rpcs to complete */
1216         cfs_waitq_signal(&lov->lov_qos.lq_statfs_waitq);
1217         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1218         wait = 0;
1219 out:
1220         if (set)
1221                 ptlrpc_set_destroy(set);
1222         if (wait) {
1223                 struct l_wait_info lwi = { 0 };
1224                 CDEBUG(D_QOS, "waiting for statfs requests to complete\n");
1225                 l_wait_event(lov->lov_qos.lq_statfs_waitq,
1226                              qos_statfs_ready(obd, max_age), &lwi);
1227                 if (cfs_time_before_64(obd->obd_osfs_age, max_age))
1228                         CDEBUG(D_QOS, "%s: still no fresh statfs data after "
1229                                       "waiting (osfs age "LPU64", max age "
1230                                       LPU64")\n",
1231                                       obd_uuid2str(&lov->desc.ld_uuid),
1232                                       obd->obd_osfs_age, max_age);
1233         }
1234 }