Whamcloud - gitweb
c1f8c9674867891efa299545b7aad0ece428ffc5
[fs/lustre-release.git] / lustre / lov / lov_qos.c
1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
2  * vim:expandtab:shiftwidth=8:tabstop=8:
3  *
4  * GPL HEADER START
5  *
6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
7  *
8  * This program is free software; you can redistribute it and/or modify
9  * it under the terms of the GNU General Public License version 2 only,
10  * as published by the Free Software Foundation.
11  *
12  * This program is distributed in the hope that it will be useful, but
13  * WITHOUT ANY WARRANTY; without even the implied warranty of
14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
15  * General Public License version 2 for more details (a copy is included
16  * in the LICENSE file that accompanied this code).
17  *
18  * You should have received a copy of the GNU General Public License
19  * version 2 along with this program; If not, see
20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
21  *
22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
23  * CA 95054 USA or visit www.sun.com if you need additional information or
24  * have any questions.
25  *
26  * GPL HEADER END
27  */
28 /*
29  * Copyright (c) 2005, 2010, Oracle and/or its affiliates. All rights reserved.
30  * Use is subject to license terms.
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 #ifndef EXPORT_SYMTAB
38 # define EXPORT_SYMTAB
39 #endif
40 #define DEBUG_SUBSYSTEM S_LOV
41
42 #ifdef __KERNEL__
43 #include <libcfs/libcfs.h>
44 #else
45 #include <liblustre.h>
46 #endif
47
48 #include <obd_class.h>
49 #include <obd_lov.h>
50 #include <lustre/lustre_idl.h>
51 #include "lov_internal.h"
52
53 /* #define QOS_DEBUG 1 */
54 #define D_QOS D_OTHER
55
56 #define TGT_BAVAIL(i) (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bavail *\
57                        lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bsize)
58
59
60 int qos_add_tgt(struct obd_device *obd, __u32 index)
61 {
62         struct lov_obd *lov = &obd->u.lov;
63         struct lov_qos_oss *oss, *temposs;
64         struct obd_export *exp = lov->lov_tgts[index]->ltd_exp;
65         int rc = 0, found = 0;
66         ENTRY;
67
68         /* We only need this QOS struct on MDT, not clients - but we may not
69          * have registered the LOV's observer yet, so there's no way to know */
70         if (!exp || !exp->exp_connection) {
71                 CERROR("Missing connection\n");
72                 RETURN(-ENOTCONN);
73         }
74
75         cfs_down_write(&lov->lov_qos.lq_rw_sem);
76         cfs_mutex_down(&lov->lov_lock);
77         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
78                 if (obd_uuid_equals(&oss->lqo_uuid,
79                                     &exp->exp_connection->c_remote_uuid)) {
80                         found++;
81                         break;
82                 }
83         }
84
85         if (!found) {
86                 OBD_ALLOC_PTR(oss);
87                 if (!oss)
88                         GOTO(out, rc = -ENOMEM);
89                 memcpy(&oss->lqo_uuid,
90                        &exp->exp_connection->c_remote_uuid,
91                        sizeof(oss->lqo_uuid));
92         } else {
93                 /* Assume we have to move this one */
94                 cfs_list_del(&oss->lqo_oss_list);
95         }
96
97         oss->lqo_ost_count++;
98         lov->lov_tgts[index]->ltd_qos.ltq_oss = oss;
99
100         /* Add sorted by # of OSTs.  Find the first entry that we're
101            bigger than... */
102         cfs_list_for_each_entry(temposs, &lov->lov_qos.lq_oss_list,
103                                 lqo_oss_list) {
104                 if (oss->lqo_ost_count > temposs->lqo_ost_count)
105                         break;
106         }
107         /* ...and add before it.  If we're the first or smallest, temposs
108            points to the list head, and we add to the end. */
109         cfs_list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
110
111         lov->lov_qos.lq_dirty = 1;
112         lov->lov_qos.lq_rr.lqr_dirty = 1;
113
114         CDEBUG(D_QOS, "add tgt %s to OSS %s (%d OSTs)\n",
115                obd_uuid2str(&lov->lov_tgts[index]->ltd_uuid),
116                obd_uuid2str(&oss->lqo_uuid),
117                oss->lqo_ost_count);
118
119 out:
120         cfs_mutex_up(&lov->lov_lock);
121         cfs_up_write(&lov->lov_qos.lq_rw_sem);
122         RETURN(rc);
123 }
124
125 int qos_del_tgt(struct obd_device *obd, struct lov_tgt_desc *tgt)
126 {
127         struct lov_obd *lov = &obd->u.lov;
128         struct lov_qos_oss *oss;
129         int rc = 0;
130         ENTRY;
131
132         cfs_down_write(&lov->lov_qos.lq_rw_sem);
133
134         oss = tgt->ltd_qos.ltq_oss;
135         if (!oss)
136                 GOTO(out, rc = -ENOENT);
137
138         oss->lqo_ost_count--;
139         if (oss->lqo_ost_count == 0) {
140                 CDEBUG(D_QOS, "removing OSS %s\n",
141                        obd_uuid2str(&oss->lqo_uuid));
142                 cfs_list_del(&oss->lqo_oss_list);
143                 OBD_FREE_PTR(oss);
144         }
145
146         lov->lov_qos.lq_dirty = 1;
147         lov->lov_qos.lq_rr.lqr_dirty = 1;
148 out:
149         cfs_up_write(&lov->lov_qos.lq_rw_sem);
150         RETURN(rc);
151 }
152
153 /* Recalculate per-object penalties for OSSs and OSTs,
154    depends on size of each ost in an oss */
155 static int qos_calc_ppo(struct obd_device *obd)
156 {
157         struct lov_obd *lov = &obd->u.lov;
158         struct lov_qos_oss *oss;
159         __u64 ba_max, ba_min, temp;
160         __u32 num_active;
161         int rc, i, prio_wide;
162         time_t now, age;
163         ENTRY;
164
165         if (!lov->lov_qos.lq_dirty)
166                 GOTO(out, rc = 0);
167
168         num_active = lov->desc.ld_active_tgt_count - 1;
169         if (num_active < 1)
170                 GOTO(out, rc = -EAGAIN);
171
172         /* find bavail on each OSS */
173         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
174                 oss->lqo_bavail = 0;
175         }
176         lov->lov_qos.lq_active_oss_count = 0;
177
178         /* How badly user wants to select osts "widely" (not recently chosen
179            and not on recent oss's).  As opposed to "freely" (free space
180            avail.) 0-256. */
181         prio_wide = 256 - lov->lov_qos.lq_prio_free;
182
183         ba_min = (__u64)(-1);
184         ba_max = 0;
185         now = cfs_time_current_sec();
186         /* Calculate OST penalty per object */
187         /* (lov ref taken in alloc_qos) */
188         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
189                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
190                         continue;
191                 temp = TGT_BAVAIL(i);
192                 if (!temp)
193                         continue;
194                 ba_min = min(temp, ba_min);
195                 ba_max = max(temp, ba_max);
196
197                 /* Count the number of usable OSS's */
198                 if (lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail == 0)
199                         lov->lov_qos.lq_active_oss_count++;
200                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail += temp;
201
202                 /* per-OST penalty is prio * TGT_bavail / (num_ost - 1) / 2 */
203                 temp >>= 1;
204                 do_div(temp, num_active);
205                 lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj =
206                         (temp * prio_wide) >> 8;
207
208                 age = (now - lov->lov_tgts[i]->ltd_qos.ltq_used) >> 3;
209                 if (lov->lov_qos.lq_reset || age > 32 * lov->desc.ld_qos_maxage)
210                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
211                 else if (age > lov->desc.ld_qos_maxage)
212                         /* Decay the penalty by half for every 8x the update
213                          * interval that the device has been idle.  That gives
214                          * lots of time for the statfs information to be
215                          * updated (which the penalty is only a proxy for),
216                          * and avoids penalizing OSS/OSTs under light load. */
217                         lov->lov_tgts[i]->ltd_qos.ltq_penalty >>=
218                                 (age / lov->desc.ld_qos_maxage);
219         }
220
221         num_active = lov->lov_qos.lq_active_oss_count - 1;
222         if (num_active < 1) {
223                 /* If there's only 1 OSS, we can't penalize it, so instead
224                    we have to double the OST penalty */
225                 num_active = 1;
226                 for (i = 0; i < lov->desc.ld_tgt_count; i++) {
227                         if (lov->lov_tgts[i] == NULL)
228                                 continue;
229                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj <<= 1;
230                 }
231         }
232
233         /* Per-OSS penalty is prio * oss_avail / oss_osts / (num_oss - 1) / 2 */
234         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
235                 temp = oss->lqo_bavail >> 1;
236                 do_div(temp, oss->lqo_ost_count * num_active);
237                 oss->lqo_penalty_per_obj = (temp * prio_wide) >> 8;
238
239                 age = (now - oss->lqo_used) >> 3;
240                 if (lov->lov_qos.lq_reset || age > 32 * lov->desc.ld_qos_maxage)
241                         oss->lqo_penalty = 0;
242                 else if (age > lov->desc.ld_qos_maxage)
243                         /* Decay the penalty by half for every 8x the update
244                          * interval that the device has been idle.  That gives
245                          * lots of time for the statfs information to be
246                          * updated (which the penalty is only a proxy for),
247                          * and avoids penalizing OSS/OSTs under light load. */
248                         oss->lqo_penalty >>= (age / lov->desc.ld_qos_maxage);
249         }
250
251         lov->lov_qos.lq_dirty = 0;
252         lov->lov_qos.lq_reset = 0;
253
254         /* If each ost has almost same free space,
255          * do rr allocation for better creation performance */
256         lov->lov_qos.lq_same_space = 0;
257         if ((ba_max * (256 - lov->lov_qos.lq_threshold_rr)) >> 8 < ba_min) {
258                 lov->lov_qos.lq_same_space = 1;
259                 /* Reset weights for the next time we enter qos mode */
260                 lov->lov_qos.lq_reset = 1;
261         }
262         rc = 0;
263
264 out:
265         if (!rc && lov->lov_qos.lq_same_space)
266                 RETURN(-EAGAIN);
267         RETURN(rc);
268 }
269
270 static int qos_calc_weight(struct lov_obd *lov, int i)
271 {
272         __u64 temp, temp2;
273
274         /* Final ost weight = TGT_BAVAIL - ost_penalty - oss_penalty */
275         temp = TGT_BAVAIL(i);
276         temp2 = lov->lov_tgts[i]->ltd_qos.ltq_penalty +
277                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty;
278         if (temp < temp2)
279                 lov->lov_tgts[i]->ltd_qos.ltq_weight = 0;
280         else
281                 lov->lov_tgts[i]->ltd_qos.ltq_weight = temp - temp2;
282         return 0;
283 }
284
285 /* We just used this index for a stripe; adjust everyone's weights */
286 static int qos_used(struct lov_obd *lov, struct ost_pool *osts,
287                     __u32 index, __u64 *total_wt)
288 {
289         struct lov_qos_oss *oss;
290         int j;
291         ENTRY;
292
293         /* Don't allocate from this stripe anymore, until the next alloc_qos */
294         lov->lov_tgts[index]->ltd_qos.ltq_usable = 0;
295
296         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
297
298         /* Decay old penalty by half (we're adding max penalty, and don't
299            want it to run away.) */
300         lov->lov_tgts[index]->ltd_qos.ltq_penalty >>= 1;
301         oss->lqo_penalty >>= 1;
302
303         /* mark the OSS and OST as recently used */
304         lov->lov_tgts[index]->ltd_qos.ltq_used =
305                 oss->lqo_used = cfs_time_current_sec();
306
307         /* Set max penalties for this OST and OSS */
308         lov->lov_tgts[index]->ltd_qos.ltq_penalty +=
309                 lov->lov_tgts[index]->ltd_qos.ltq_penalty_per_obj *
310                 lov->desc.ld_active_tgt_count;
311         oss->lqo_penalty += oss->lqo_penalty_per_obj *
312                 lov->lov_qos.lq_active_oss_count;
313
314         /* Decrease all OSS penalties */
315         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
316                 if (oss->lqo_penalty < oss->lqo_penalty_per_obj)
317                         oss->lqo_penalty = 0;
318                 else
319                         oss->lqo_penalty -= oss->lqo_penalty_per_obj;
320         }
321
322         *total_wt = 0;
323         /* Decrease all OST penalties */
324         for (j = 0; j < osts->op_count; j++) {
325                 int i;
326
327                 i = osts->op_array[j];
328                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
329                         continue;
330                 if (lov->lov_tgts[i]->ltd_qos.ltq_penalty <
331                     lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj)
332                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
333                 else
334                         lov->lov_tgts[i]->ltd_qos.ltq_penalty -=
335                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj;
336
337                 qos_calc_weight(lov, i);
338
339                 /* Recalc the total weight of usable osts */
340                 if (lov->lov_tgts[i]->ltd_qos.ltq_usable)
341                         *total_wt += lov->lov_tgts[i]->ltd_qos.ltq_weight;
342
343 #ifdef QOS_DEBUG
344                 CDEBUG(D_QOS, "recalc tgt %d usable=%d avail="LPU64
345                        " ostppo="LPU64" ostp="LPU64" ossppo="LPU64
346                        " ossp="LPU64" wt="LPU64"\n",
347                        i, lov->lov_tgts[i]->ltd_qos.ltq_usable,
348                        TGT_BAVAIL(i) >> 10,
349                        lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj >> 10,
350                        lov->lov_tgts[i]->ltd_qos.ltq_penalty >> 10,
351                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty_per_obj>>10,
352                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty >> 10,
353                        lov->lov_tgts[i]->ltd_qos.ltq_weight >> 10);
354 #endif
355         }
356
357         RETURN(0);
358 }
359
360 #define LOV_QOS_EMPTY ((__u32)-1)
361 /* compute optimal round-robin order, based on OSTs per OSS */
362 static int qos_calc_rr(struct lov_obd *lov, struct ost_pool *src_pool,
363                        struct lov_qos_rr *lqr)
364 {
365         struct lov_qos_oss *oss;
366         unsigned placed, real_count;
367         int i, rc;
368         ENTRY;
369
370         if (!lqr->lqr_dirty) {
371                 LASSERT(lqr->lqr_pool.op_size);
372                 RETURN(0);
373         }
374
375         /* Do actual allocation. */
376         cfs_down_write(&lov->lov_qos.lq_rw_sem);
377
378         /*
379          * Check again. While we were sleeping on @lq_rw_sem something could
380          * change.
381          */
382         if (!lqr->lqr_dirty) {
383                 LASSERT(lqr->lqr_pool.op_size);
384                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
385                 RETURN(0);
386         }
387
388         real_count = src_pool->op_count;
389
390         /* Zero the pool array */
391         /* alloc_rr is holding a read lock on the pool, so nobody is adding/
392            deleting from the pool. The lq_rw_sem insures that nobody else
393            is reading. */
394         lqr->lqr_pool.op_count = real_count;
395         rc = lov_ost_pool_extend(&lqr->lqr_pool, real_count);
396         if (rc) {
397                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
398                 RETURN(rc);
399         }
400         for (i = 0; i < lqr->lqr_pool.op_count; i++)
401                 lqr->lqr_pool.op_array[i] = LOV_QOS_EMPTY;
402
403         /* Place all the OSTs from 1 OSS at the same time. */
404         placed = 0;
405         cfs_list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
406                 int j = 0;
407                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
408                         if (lov->lov_tgts[src_pool->op_array[i]] &&
409                             (lov->lov_tgts[src_pool->op_array[i]]->ltd_qos.ltq_oss == oss)) {
410                               /* Evenly space these OSTs across arrayspace */
411                               int next = j * lqr->lqr_pool.op_count / oss->lqo_ost_count;
412                               while (lqr->lqr_pool.op_array[next] !=
413                                      LOV_QOS_EMPTY)
414                                         next = (next + 1) % lqr->lqr_pool.op_count;
415                               lqr->lqr_pool.op_array[next] = src_pool->op_array[i];
416                               j++;
417                               placed++;
418                         }
419                 }
420         }
421
422         lqr->lqr_dirty = 0;
423         cfs_up_write(&lov->lov_qos.lq_rw_sem);
424
425         if (placed != real_count) {
426                 /* This should never happen */
427                 LCONSOLE_ERROR_MSG(0x14e, "Failed to place all OSTs in the "
428                                    "round-robin list (%d of %d).\n",
429                                    placed, real_count);
430                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
431                         LCONSOLE(D_WARNING, "rr #%d ost idx=%d\n", i,
432                                  lqr->lqr_pool.op_array[i]);
433                 }
434                 lqr->lqr_dirty = 1;
435                 RETURN(-EAGAIN);
436         }
437
438 #ifdef QOS_DEBUG
439         for (i = 0; i < lqr->lqr_pool.op_count; i++) {
440                 LCONSOLE(D_QOS, "rr #%d ost idx=%d\n", i,
441                          lqr->lqr_pool.op_array[i]);
442         }
443 #endif
444
445         RETURN(0);
446 }
447
448
449 void qos_shrink_lsm(struct lov_request_set *set)
450 {
451         struct lov_stripe_md *lsm = set->set_oi->oi_md, *lsm_new;
452         /* XXX LOV STACKING call into osc for sizes */
453         unsigned oldsize, newsize;
454
455         if (set->set_oti && set->set_cookies && set->set_cookie_sent) {
456                 struct llog_cookie *cookies;
457                 oldsize = lsm->lsm_stripe_count * sizeof(*cookies);
458                 newsize = set->set_count * sizeof(*cookies);
459
460                 cookies = set->set_cookies;
461                 oti_alloc_cookies(set->set_oti, set->set_count);
462                 if (set->set_oti->oti_logcookies) {
463                         memcpy(set->set_oti->oti_logcookies, cookies, newsize);
464                         OBD_FREE_LARGE(cookies, oldsize);
465                         set->set_cookies = set->set_oti->oti_logcookies;
466                 } else {
467                         CWARN("'leaking' %d bytes\n", oldsize - newsize);
468                 }
469         }
470
471         CWARN("using fewer stripes for object "LPU64": old %u new %u\n",
472               lsm->lsm_object_id, lsm->lsm_stripe_count, set->set_count);
473         LASSERT(lsm->lsm_stripe_count >= set->set_count);
474
475         newsize = lov_stripe_md_size(set->set_count);
476         OBD_ALLOC_LARGE(lsm_new, newsize);
477         if (lsm_new != NULL) {
478                 int i;
479                 memcpy(lsm_new, lsm, sizeof(*lsm));
480                 for (i = 0; i < lsm->lsm_stripe_count; i++) {
481                         if (i < set->set_count) {
482                                 lsm_new->lsm_oinfo[i] = lsm->lsm_oinfo[i];
483                                 continue;
484                         }
485                         OBD_SLAB_FREE(lsm->lsm_oinfo[i], lov_oinfo_slab,
486                                       sizeof(struct lov_oinfo));
487                 }
488                 lsm_new->lsm_stripe_count = set->set_count;
489                 OBD_FREE_LARGE(lsm, sizeof(struct lov_stripe_md) +
490                                lsm->lsm_stripe_count*sizeof(struct lov_oinfo*));
491                 set->set_oi->oi_md = lsm_new;
492         } else {
493                 CWARN("'leaking' few bytes\n");
494         }
495 }
496
497 /**
498  * Check whether we can create the object on the OST(refered by ost_idx)
499  * \retval:
500  *          0: create the object.
501  *          other value: did not create the object.
502  */
503 static int lov_check_and_create_object(struct lov_obd *lov, int ost_idx,
504                                        struct lov_stripe_md *lsm,
505                                        struct lov_request *req,
506                                        struct obd_trans_info *oti)
507 {
508         int stripe;
509         int rc = -EIO;
510         ENTRY;
511
512         CDEBUG(D_QOS, "Check and create on idx %d \n", ost_idx);
513         if (!lov->lov_tgts[ost_idx] ||
514             !lov->lov_tgts[ost_idx]->ltd_active)
515                 RETURN(rc);
516
517         /* check if objects has been created on this ost */
518         for (stripe = 0; stripe < lsm->lsm_stripe_count; stripe++) {
519                 /* already have object at this stripe */
520                 if (ost_idx == lsm->lsm_oinfo[stripe]->loi_ost_idx)
521                         break;
522         }
523
524         if (stripe >= lsm->lsm_stripe_count) {
525                 req->rq_idx = ost_idx;
526                 rc = obd_create(lov->lov_tgts[ost_idx]->ltd_exp,
527                                 req->rq_oi.oi_oa, &req->rq_oi.oi_md,
528                                 oti);
529         }
530         RETURN(rc);
531 }
532
533 int qos_remedy_create(struct lov_request_set *set, struct lov_request *req)
534 {
535         struct lov_stripe_md *lsm = set->set_oi->oi_md;
536         struct lov_obd *lov = &set->set_exp->exp_obd->u.lov;
537         unsigned ost_idx = 0, ost_count;
538         struct pool_desc *pool;
539         struct ost_pool *osts = NULL;
540         int i, rc = -EIO;
541         ENTRY;
542
543         /* First check whether we can create the objects on the pool */
544         pool = lov_find_pool(lov, lsm->lsm_pool_name);
545         if (pool != NULL) {
546                 cfs_down_read(&pool_tgt_rw_sem(pool));
547                 osts = &(pool->pool_obds);
548                 ost_count = osts->op_count;
549                 for (i = 0; i < ost_count; i++, ost_idx = osts->op_array[i]) {
550                         rc = lov_check_and_create_object(lov, ost_idx, lsm, req,
551                                                          set->set_oti);
552                         if (rc == 0)
553                                 break;
554                 }
555                 cfs_up_read(&pool_tgt_rw_sem(pool));
556                 lov_pool_putref(pool);
557                 RETURN(rc);
558         }
559
560         ost_count = lov->desc.ld_tgt_count;
561         /* Then check whether we can create the objects on other OSTs */
562         ost_idx = (req->rq_idx + lsm->lsm_stripe_count) % ost_count;
563         for (i = 0; i < ost_count; i++, ost_idx = (ost_idx + 1) % ost_count) {
564                 rc = lov_check_and_create_object(lov, ost_idx, lsm, req,
565                                                  set->set_oti);
566
567                 if (rc == 0)
568                         break;
569         }
570
571         RETURN(rc);
572 }
573
574 static int min_stripe_count(int stripe_cnt, int flags)
575 {
576         return (flags & LOV_USES_DEFAULT_STRIPE ?
577                 stripe_cnt - (stripe_cnt / 4) : stripe_cnt);
578 }
579
580 #define LOV_CREATE_RESEED_MULT 30
581 #define LOV_CREATE_RESEED_MIN  2000
582 /* Allocate objects on osts with round-robin algorithm */
583 static int alloc_rr(struct lov_obd *lov, int *idx_arr, int *stripe_cnt,
584                     char *poolname, int flags)
585 {
586         unsigned array_idx;
587         int i, rc, *idx_pos;
588         __u32 ost_idx;
589         int ost_start_idx_temp;
590         int speed = 0;
591         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
592         struct pool_desc *pool;
593         struct ost_pool *osts;
594         struct lov_qos_rr *lqr;
595         ENTRY;
596
597         pool = lov_find_pool(lov, poolname);
598         if (pool == NULL) {
599                 osts = &(lov->lov_packed);
600                 lqr = &(lov->lov_qos.lq_rr);
601         } else {
602                 cfs_down_read(&pool_tgt_rw_sem(pool));
603                 osts = &(pool->pool_obds);
604                 lqr = &(pool->pool_rr);
605         }
606
607         rc = qos_calc_rr(lov, osts, lqr);
608         if (rc)
609                 GOTO(out, rc);
610
611         if (--lqr->lqr_start_count <= 0) {
612                 lqr->lqr_start_idx = cfs_rand() % osts->op_count;
613                 lqr->lqr_start_count =
614                         (LOV_CREATE_RESEED_MIN / max(osts->op_count, 1U) +
615                          LOV_CREATE_RESEED_MULT) * max(osts->op_count, 1U);
616         } else if (stripe_cnt_min >= osts->op_count ||
617                    lqr->lqr_start_idx > osts->op_count) {
618                 /* If we have allocated from all of the OSTs, slowly
619                  * precess the next start if the OST/stripe count isn't
620                  * already doing this for us. */
621                 lqr->lqr_start_idx %= osts->op_count;
622                 if (*stripe_cnt > 1 && (osts->op_count % (*stripe_cnt)) != 1)
623                         ++lqr->lqr_offset_idx;
624         }
625         cfs_down_read(&lov->lov_qos.lq_rw_sem);
626         ost_start_idx_temp = lqr->lqr_start_idx;
627
628 repeat_find:
629         array_idx = (lqr->lqr_start_idx + lqr->lqr_offset_idx) % osts->op_count;
630         idx_pos = idx_arr;
631 #ifdef QOS_DEBUG
632         CDEBUG(D_QOS, "pool '%s' want %d startidx %d startcnt %d offset %d "
633                "active %d count %d arrayidx %d\n", poolname,
634                *stripe_cnt, lqr->lqr_start_idx, lqr->lqr_start_count,
635                lqr->lqr_offset_idx, osts->op_count, osts->op_count, array_idx);
636 #endif
637
638         for (i = 0; i < osts->op_count;
639                     i++, array_idx=(array_idx + 1) % osts->op_count) {
640                 ++lqr->lqr_start_idx;
641                 ost_idx = lqr->lqr_pool.op_array[array_idx];
642 #ifdef QOS_DEBUG
643                 CDEBUG(D_QOS, "#%d strt %d act %d strp %d ary %d idx %d\n",
644                        i, lqr->lqr_start_idx,
645                        ((ost_idx != LOV_QOS_EMPTY) && lov->lov_tgts[ost_idx]) ?
646                        lov->lov_tgts[ost_idx]->ltd_active : 0,
647                        idx_pos - idx_arr, array_idx, ost_idx);
648 #endif
649                 if ((ost_idx == LOV_QOS_EMPTY) || !lov->lov_tgts[ost_idx] ||
650                     !lov->lov_tgts[ost_idx]->ltd_active)
651                         continue;
652
653                 /* Fail Check before osc_precreate() is called
654                    so we can only 'fail' single OSC. */
655                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
656                         continue;
657
658                 /* Drop slow OSCs if we can */
659                 if (obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed)
660                         continue;
661
662                 *idx_pos = ost_idx;
663                 idx_pos++;
664                 /* We have enough stripes */
665                 if (idx_pos - idx_arr == *stripe_cnt)
666                         break;
667         }
668         if ((speed < 2) && (idx_pos - idx_arr < stripe_cnt_min)) {
669                 /* Try again, allowing slower OSCs */
670                 speed++;
671                 lqr->lqr_start_idx = ost_start_idx_temp;
672                 goto repeat_find;
673         }
674
675         cfs_up_read(&lov->lov_qos.lq_rw_sem);
676
677         *stripe_cnt = idx_pos - idx_arr;
678 out:
679         if (pool != NULL) {
680                 cfs_up_read(&pool_tgt_rw_sem(pool));
681                 /* put back ref got by lov_find_pool() */
682                 lov_pool_putref(pool);
683         }
684
685         RETURN(rc);
686 }
687
688 /* alloc objects on osts with specific stripe offset */
689 static int alloc_specific(struct lov_obd *lov, struct lov_stripe_md *lsm,
690                           int *idx_arr)
691 {
692         unsigned ost_idx, array_idx, ost_count;
693         int i, rc, *idx_pos;
694         int speed = 0;
695         struct pool_desc *pool;
696         struct ost_pool *osts;
697         ENTRY;
698
699         pool = lov_find_pool(lov, lsm->lsm_pool_name);
700         if (pool == NULL) {
701                 osts = &(lov->lov_packed);
702         } else {
703                 cfs_down_read(&pool_tgt_rw_sem(pool));
704                 osts = &(pool->pool_obds);
705         }
706
707         ost_count = osts->op_count;
708
709 repeat_find:
710         /* search loi_ost_idx in ost array */
711         array_idx = 0;
712         for (i = 0; i < ost_count; i++) {
713                 if (osts->op_array[i] == lsm->lsm_oinfo[0]->loi_ost_idx) {
714                         array_idx = i;
715                         break;
716                 }
717         }
718         if (i == ost_count) {
719                 CERROR("Start index %d not found in pool '%s'\n",
720                        lsm->lsm_oinfo[0]->loi_ost_idx, lsm->lsm_pool_name);
721                 GOTO(out, rc = -EINVAL);
722         }
723
724         idx_pos = idx_arr;
725         for (i = 0; i < ost_count;
726              i++, array_idx = (array_idx + 1) % ost_count) {
727                 ost_idx = osts->op_array[array_idx];
728
729                 if (!lov->lov_tgts[ost_idx] ||
730                     !lov->lov_tgts[ost_idx]->ltd_active) {
731                         continue;
732                 }
733
734                 /* Fail Check before osc_precreate() is called
735                    so we can only 'fail' single OSC. */
736                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
737                         continue;
738
739                 /* Drop slow OSCs if we can, but not for requested start idx.
740                  *
741                  * This means "if OSC is slow and it is not the requested
742                  * start OST, then it can be skipped, otherwise skip it only
743                  * if it is inactive/recovering/out-of-space." */
744                 if ((obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed) &&
745                     (i != 0 || speed >= 2))
746                         continue;
747
748                 *idx_pos = ost_idx;
749                 idx_pos++;
750                 /* We have enough stripes */
751                 if (idx_pos - idx_arr == lsm->lsm_stripe_count)
752                         GOTO(out, rc = 0);
753         }
754         if (speed < 2) {
755                 /* Try again, allowing slower OSCs */
756                 speed++;
757                 goto repeat_find;
758         }
759
760         /* If we were passed specific striping params, then a failure to
761          * meet those requirements is an error, since we can't reallocate
762          * that memory (it might be part of a larger array or something).
763          *
764          * We can only get here if lsm_stripe_count was originally > 1.
765          */
766         CERROR("can't lstripe objid "LPX64": have %d want %u\n",
767                lsm->lsm_object_id, (int)(idx_pos - idx_arr),
768                lsm->lsm_stripe_count);
769         rc = -EFBIG;
770 out:
771         if (pool != NULL) {
772                 cfs_up_read(&pool_tgt_rw_sem(pool));
773                 /* put back ref got by lov_find_pool() */
774                 lov_pool_putref(pool);
775         }
776
777         RETURN(rc);
778 }
779
780 /* Alloc objects on osts with optimization based on:
781    - free space
782    - network resources (shared OSS's)
783 */
784 static int alloc_qos(struct obd_export *exp, int *idx_arr, int *stripe_cnt,
785                      char *poolname, int flags)
786 {
787         struct lov_obd *lov = &exp->exp_obd->u.lov;
788         __u64 total_weight = 0;
789         int nfound, good_osts, i, rc = 0;
790         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
791         struct pool_desc *pool;
792         struct ost_pool *osts;
793         struct lov_qos_rr *lqr;
794         ENTRY;
795
796         if (stripe_cnt_min < 1)
797                 RETURN(-EINVAL);
798
799         pool = lov_find_pool(lov, poolname);
800         if (pool == NULL) {
801                 osts = &(lov->lov_packed);
802                 lqr = &(lov->lov_qos.lq_rr);
803         } else {
804                 cfs_down_read(&pool_tgt_rw_sem(pool));
805                 osts = &(pool->pool_obds);
806                 lqr = &(pool->pool_rr);
807         }
808
809         obd_getref(exp->exp_obd);
810
811         /* wait for fresh statfs info if needed, the rpcs are sent in
812          * lov_create() */
813         qos_statfs_update(exp->exp_obd,
814                           cfs_time_shift_64(-2 * lov->desc.ld_qos_maxage), 1);
815
816         /* Detect -EAGAIN early, before expensive lock is taken. */
817         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
818                 GOTO(out_nolock, rc = -EAGAIN);
819
820         /* Do actual allocation, use write lock here. */
821         cfs_down_write(&lov->lov_qos.lq_rw_sem);
822
823         /*
824          * Check again, while we were sleeping on @lq_rw_sem things could
825          * change.
826          */
827         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
828                 GOTO(out, rc = -EAGAIN);
829
830         if (lov->desc.ld_active_tgt_count < 2)
831                 GOTO(out, rc = -EAGAIN);
832
833         rc = qos_calc_ppo(exp->exp_obd);
834         if (rc)
835                 GOTO(out, rc);
836
837         good_osts = 0;
838         /* Find all the OSTs that are valid stripe candidates */
839         for (i = 0; i < osts->op_count; i++) {
840                 if (!lov->lov_tgts[osts->op_array[i]] ||
841                     !lov->lov_tgts[osts->op_array[i]]->ltd_active)
842                         continue;
843
844                 /* Fail Check before osc_precreate() is called
845                    so we can only 'fail' single OSC. */
846                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && osts->op_array[i] == 0)
847                         continue;
848
849                 if (obd_precreate(lov->lov_tgts[osts->op_array[i]]->ltd_exp) > 2)
850                         continue;
851
852                 lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable = 1;
853                 qos_calc_weight(lov, osts->op_array[i]);
854                 total_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
855
856                 good_osts++;
857         }
858
859 #ifdef QOS_DEBUG
860         CDEBUG(D_QOS, "found %d good osts\n", good_osts);
861 #endif
862
863         if (good_osts < stripe_cnt_min)
864                 GOTO(out, rc = -EAGAIN);
865
866         /* We have enough osts */
867         if (good_osts < *stripe_cnt)
868                 *stripe_cnt = good_osts;
869
870         if (!*stripe_cnt)
871                 GOTO(out, rc = -EAGAIN);
872
873         /* Find enough OSTs with weighted random allocation. */
874         nfound = 0;
875         while (nfound < *stripe_cnt) {
876                 __u64 rand, cur_weight;
877
878                 cur_weight = 0;
879                 rc = -ENODEV;
880
881                 if (total_weight) {
882 #if BITS_PER_LONG == 32
883                         rand = cfs_rand() % (unsigned)total_weight;
884                         /* If total_weight > 32-bit, first generate the high
885                          * 32 bits of the random number, then add in the low
886                          * 32 bits (truncated to the upper limit, if needed) */
887                         if (total_weight > 0xffffffffULL)
888                                 rand = (__u64)(cfs_rand() %
889                                           (unsigned)(total_weight >> 32)) << 32;
890                         else
891                                 rand = 0;
892
893                         if (rand == (total_weight & 0xffffffff00000000ULL))
894                                 rand |= cfs_rand() % (unsigned)total_weight;
895                         else
896                                 rand |= cfs_rand();
897
898 #else
899                         rand = ((__u64)cfs_rand() << 32 | cfs_rand()) %
900                                 total_weight;
901 #endif
902                 } else {
903                         rand = 0;
904                 }
905
906                 /* On average, this will hit larger-weighted osts more often.
907                    0-weight osts will always get used last (only when rand=0).*/
908                 for (i = 0; i < osts->op_count; i++) {
909                         if (!lov->lov_tgts[osts->op_array[i]] ||
910                             !lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable)
911                                 continue;
912
913                         cur_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
914 #ifdef QOS_DEBUG
915                         CDEBUG(D_QOS, "stripe_cnt=%d nfound=%d cur_weight="LPU64
916                                       " rand="LPU64" total_weight="LPU64"\n",
917                                *stripe_cnt, nfound, cur_weight, rand, total_weight);
918 #endif
919                         if (cur_weight >= rand) {
920 #ifdef QOS_DEBUG
921                                 CDEBUG(D_QOS, "assigned stripe=%d to idx=%d\n",
922                                        nfound, osts->op_array[i]);
923 #endif
924                                 idx_arr[nfound++] = osts->op_array[i];
925                                 qos_used(lov, osts, osts->op_array[i], &total_weight);
926                                 rc = 0;
927                                 break;
928                         }
929                 }
930                 /* should never satisfy below condition */
931                 if (rc) {
932                         CERROR("Didn't find any OSTs?\n");
933                         break;
934                 }
935         }
936         LASSERT(nfound == *stripe_cnt);
937
938 out:
939         cfs_up_write(&lov->lov_qos.lq_rw_sem);
940
941 out_nolock:
942         if (pool != NULL) {
943                 cfs_up_read(&pool_tgt_rw_sem(pool));
944                 /* put back ref got by lov_find_pool() */
945                 lov_pool_putref(pool);
946         }
947
948         if (rc == -EAGAIN)
949                 rc = alloc_rr(lov, idx_arr, stripe_cnt, poolname, flags);
950
951         obd_putref(exp->exp_obd);
952         RETURN(rc);
953 }
954
955 /* return new alloced stripe count on success */
956 static int alloc_idx_array(struct obd_export *exp, struct lov_stripe_md *lsm,
957                            int newea, int **idx_arr, int *arr_cnt, int flags)
958 {
959         struct lov_obd *lov = &exp->exp_obd->u.lov;
960         int stripe_cnt = lsm->lsm_stripe_count;
961         int i, rc = 0;
962         int *tmp_arr = NULL;
963         ENTRY;
964
965         *arr_cnt = stripe_cnt;
966         OBD_ALLOC(tmp_arr, *arr_cnt * sizeof(int));
967         if (tmp_arr == NULL)
968                 RETURN(-ENOMEM);
969         for (i = 0; i < *arr_cnt; i++)
970                 tmp_arr[i] = -1;
971
972         if (newea ||
973             lsm->lsm_oinfo[0]->loi_ost_idx >= lov->desc.ld_tgt_count)
974                 rc = alloc_qos(exp, tmp_arr, &stripe_cnt,
975                                lsm->lsm_pool_name, flags);
976         else
977                 rc = alloc_specific(lov, lsm, tmp_arr);
978
979         if (rc)
980                 GOTO(out_arr, rc);
981
982         *idx_arr = tmp_arr;
983         RETURN(stripe_cnt);
984 out_arr:
985         OBD_FREE(tmp_arr, *arr_cnt * sizeof(int));
986         *arr_cnt = 0;
987         RETURN(rc);
988 }
989
990 static void free_idx_array(int *idx_arr, int arr_cnt)
991 {
992         if (arr_cnt)
993                 OBD_FREE(idx_arr, arr_cnt * sizeof(int));
994 }
995
996 int qos_prep_create(struct obd_export *exp, struct lov_request_set *set)
997 {
998         struct lov_obd *lov = &exp->exp_obd->u.lov;
999         struct lov_stripe_md *lsm;
1000         struct obdo *src_oa = set->set_oi->oi_oa;
1001         struct obd_trans_info *oti = set->set_oti;
1002         int i, stripes, rc = 0, newea = 0;
1003         int flag = LOV_USES_ASSIGNED_STRIPE;
1004         int *idx_arr = NULL, idx_cnt = 0;
1005         ENTRY;
1006
1007         LASSERT(src_oa->o_valid & OBD_MD_FLID);
1008         LASSERT(src_oa->o_valid & OBD_MD_FLGROUP);
1009
1010         if (set->set_oi->oi_md == NULL) {
1011                 int stripes_def = lov_get_stripecnt(lov, 0);
1012
1013                 /* If the MDS file was truncated up to some size, stripe over
1014                  * enough OSTs to allow the file to be created at that size.
1015                  * This may mean we use more than the default # of stripes. */
1016                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
1017                         obd_size min_bavail = LUSTRE_STRIPE_MAXBYTES;
1018
1019                         /* Find a small number of stripes we can use
1020                            (up to # of active osts). */
1021                         stripes = 1;
1022                         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
1023                                 if (!lov->lov_tgts[i] ||
1024                                     !lov->lov_tgts[i]->ltd_active)
1025                                         continue;
1026                                 min_bavail = min(min_bavail, TGT_BAVAIL(i));
1027                                 if (min_bavail * stripes > src_oa->o_size)
1028                                         break;
1029                                 stripes++;
1030                         }
1031
1032                         if (stripes < stripes_def)
1033                                 stripes = stripes_def;
1034                 } else {
1035                          flag = LOV_USES_DEFAULT_STRIPE;
1036                          stripes = stripes_def;
1037                 }
1038
1039                 rc = lov_alloc_memmd(&set->set_oi->oi_md, stripes,
1040                                      lov->desc.ld_pattern ?
1041                                      lov->desc.ld_pattern : LOV_PATTERN_RAID0,
1042                                      LOV_MAGIC);
1043                 if (rc < 0)
1044                         GOTO(out_err, rc);
1045                 newea = 1;
1046                 rc = 0;
1047         }
1048
1049         lsm = set->set_oi->oi_md;
1050         lsm->lsm_object_id = src_oa->o_id;
1051         lsm->lsm_object_seq = src_oa->o_seq;
1052
1053         if (!lsm->lsm_stripe_size)
1054                 lsm->lsm_stripe_size = lov->desc.ld_default_stripe_size;
1055         if (!lsm->lsm_pattern) {
1056                 LASSERT(lov->desc.ld_pattern);
1057                 lsm->lsm_pattern = lov->desc.ld_pattern;
1058         }
1059
1060         stripes = alloc_idx_array(exp, lsm, newea, &idx_arr, &idx_cnt, flag);
1061         if (stripes <= 0)
1062                 GOTO(out_err, rc = stripes ? stripes : -EIO);
1063         LASSERTF(stripes <= lsm->lsm_stripe_count,"requested %d allocated %d\n",
1064                  lsm->lsm_stripe_count, stripes);
1065
1066         for (i = 0; i < stripes; i++) {
1067                 struct lov_request *req;
1068                 int ost_idx = idx_arr[i];
1069                 LASSERT(ost_idx >= 0);
1070
1071                 OBD_ALLOC(req, sizeof(*req));
1072                 if (req == NULL)
1073                         GOTO(out_err, rc = -ENOMEM);
1074                 lov_set_add_req(req, set);
1075
1076                 req->rq_buflen = sizeof(*req->rq_oi.oi_md);
1077                 OBD_ALLOC_LARGE(req->rq_oi.oi_md, req->rq_buflen);
1078                 if (req->rq_oi.oi_md == NULL)
1079                         GOTO(out_err, rc = -ENOMEM);
1080
1081                 OBDO_ALLOC(req->rq_oi.oi_oa);
1082                 if (req->rq_oi.oi_oa == NULL)
1083                         GOTO(out_err, rc = -ENOMEM);
1084
1085                 req->rq_idx = ost_idx;
1086                 req->rq_stripe = i;
1087                 /* create data objects with "parent" OA */
1088                 memcpy(req->rq_oi.oi_oa, src_oa, sizeof(*req->rq_oi.oi_oa));
1089                 req->rq_oi.oi_cb_up = cb_create_update;
1090
1091                 /* XXX When we start creating objects on demand, we need to
1092                  *     make sure that we always create the object on the
1093                  *     stripe which holds the existing file size.
1094                  */
1095                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
1096                         req->rq_oi.oi_oa->o_size =
1097                                 lov_size_to_stripe(lsm, src_oa->o_size, i);
1098
1099                         CDEBUG(D_INODE, "stripe %d has size "LPU64"/"LPU64"\n",
1100                                i, req->rq_oi.oi_oa->o_size, src_oa->o_size);
1101                 }
1102         }
1103         LASSERT(set->set_count == stripes);
1104
1105         if (stripes < lsm->lsm_stripe_count)
1106                 qos_shrink_lsm(set);
1107         if (OBD_FAIL_CHECK(OBD_FAIL_MDS_LOV_PREP_CREATE)) {
1108                 qos_shrink_lsm(set);
1109                 rc = -EIO;
1110         }
1111
1112         if (oti && (src_oa->o_valid & OBD_MD_FLCOOKIE)) {
1113                 oti_alloc_cookies(oti, set->set_count);
1114                 if (!oti->oti_logcookies)
1115                         GOTO(out_err, rc = -ENOMEM);
1116                 set->set_cookies = oti->oti_logcookies;
1117         }
1118 out_err:
1119         if (newea && rc)
1120                 obd_free_memmd(exp, &set->set_oi->oi_md);
1121         if (idx_arr)
1122                 free_idx_array(idx_arr, idx_cnt);
1123         EXIT;
1124         return rc;
1125 }
1126
1127 void qos_update(struct lov_obd *lov)
1128 {
1129         ENTRY;
1130         lov->lov_qos.lq_dirty = 1;
1131 }
1132
1133 void qos_statfs_done(struct lov_obd *lov)
1134 {
1135         LASSERT(lov->lov_qos.lq_statfs_in_progress);
1136         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1137         lov->lov_qos.lq_statfs_in_progress = 0;
1138         /* wake up any threads waiting for the statfs rpcs to complete */
1139         cfs_waitq_signal(&lov->lov_qos.lq_statfs_waitq);
1140         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1141 }
1142
1143 static int qos_statfs_ready(struct obd_device *obd, __u64 max_age)
1144 {
1145         struct lov_obd         *lov = &obd->u.lov;
1146         int rc;
1147         ENTRY;
1148         cfs_down_read(&lov->lov_qos.lq_rw_sem);
1149         rc = lov->lov_qos.lq_statfs_in_progress == 0 ||
1150              cfs_time_beforeq_64(max_age, obd->obd_osfs_age);
1151         cfs_up_read(&lov->lov_qos.lq_rw_sem);
1152         RETURN(rc);
1153 }
1154
1155 /*
1156  * Update statfs data if the current osfs age is older than max_age.
1157  * If wait is not set, it means that we are called from lov_create()
1158  * and we should just issue the rpcs without waiting for them to complete.
1159  * If wait is set, we are called from alloc_qos() and we just have
1160  * to wait for the request set to complete.
1161  */
1162 void qos_statfs_update(struct obd_device *obd, __u64 max_age, int wait)
1163 {
1164         struct lov_obd         *lov = &obd->u.lov;
1165         struct obd_info        *oinfo;
1166         int                     rc = 0;
1167         struct ptlrpc_request_set *set = NULL;
1168         ENTRY;
1169
1170         if (cfs_time_beforeq_64(max_age, obd->obd_osfs_age))
1171                 /* statfs data are quite recent, don't need to refresh it */
1172                 RETURN_EXIT;
1173
1174         if (!wait && lov->lov_qos.lq_statfs_in_progress)
1175                 /* statfs already in progress */
1176                 RETURN_EXIT;
1177
1178         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1179         if (lov->lov_qos.lq_statfs_in_progress) {
1180                 cfs_up_write(&lov->lov_qos.lq_rw_sem);
1181                 GOTO(out, rc = 0);
1182         }
1183         /* no statfs in flight, send rpcs */
1184         lov->lov_qos.lq_statfs_in_progress = 1;
1185         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1186
1187         if (wait)
1188                 CDEBUG(D_QOS, "%s: did not manage to get fresh statfs data "
1189                        "in a timely manner (osfs age "LPU64", max age "LPU64")"
1190                        ", sending new statfs rpcs\n",
1191                        obd_uuid2str(&lov->desc.ld_uuid), obd->obd_osfs_age,
1192                        max_age);
1193
1194         /* need to send statfs rpcs */
1195         CDEBUG(D_QOS, "sending new statfs requests\n");
1196         memset(lov->lov_qos.lq_statfs_data, 0,
1197                sizeof(*lov->lov_qos.lq_statfs_data));
1198         oinfo = &lov->lov_qos.lq_statfs_data->lsd_oi;
1199         oinfo->oi_osfs = &lov->lov_qos.lq_statfs_data->lsd_statfs;
1200         oinfo->oi_flags = OBD_STATFS_NODELAY;
1201         set = ptlrpc_prep_set();
1202         if (!set)
1203                 GOTO(out_failed, rc = -ENOMEM);
1204
1205         rc = obd_statfs_async(obd, oinfo, max_age, set);
1206         if (rc || cfs_list_empty(&set->set_requests)) {
1207                 if (rc)
1208                         CWARN("statfs failed with %d\n", rc);
1209                 GOTO(out_failed, rc);
1210         }
1211         /* send requests via ptlrpcd */
1212         oinfo->oi_flags |= OBD_STATFS_PTLRPCD;
1213         ptlrpcd_add_rqset(set);
1214         GOTO(out, rc);
1215
1216 out_failed:
1217         cfs_down_write(&lov->lov_qos.lq_rw_sem);
1218         lov->lov_qos.lq_statfs_in_progress = 0;
1219         /* wake up any threads waiting for the statfs rpcs to complete */
1220         cfs_waitq_signal(&lov->lov_qos.lq_statfs_waitq);
1221         cfs_up_write(&lov->lov_qos.lq_rw_sem);
1222         wait = 0;
1223 out:
1224         if (set)
1225                 ptlrpc_set_destroy(set);
1226         if (wait) {
1227                 struct l_wait_info lwi = { 0 };
1228                 CDEBUG(D_QOS, "waiting for statfs requests to complete\n");
1229                 l_wait_event(lov->lov_qos.lq_statfs_waitq,
1230                              qos_statfs_ready(obd, max_age), &lwi);
1231                 if (cfs_time_before_64(obd->obd_osfs_age, max_age))
1232                         CDEBUG(D_QOS, "%s: still no fresh statfs data after "
1233                                       "waiting (osfs age "LPU64", max age "
1234                                       LPU64")\n",
1235                                       obd_uuid2str(&lov->desc.ld_uuid),
1236                                       obd->obd_osfs_age, max_age);
1237         }
1238 }