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  2008 Sun Microsystems, Inc. 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 "lov_internal.h"
  51
  52 /* #define QOS_DEBUG 1 */
  53 #define D_QOS D_OTHER
  54
  55 #define TGT_BAVAIL(i) (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bavail *\
  56                        lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bsize)
  57 #define TGT_FFREE(i)  (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_ffree)
  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         down_write(&lov->lov_qos.lq_rw_sem);
  76         mutex_down(&lov->lov_lock);
  77         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                 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         list_for_each_entry(temposs, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 103                 if (oss->lqo_ost_count > temposs->lqo_ost_count)
 104                         break;
 105         }
 106         /* ...and add before it.  If we're the first or smallest, temposs
 107            points to the list head, and we add to the end. */
 108         list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
 109
 110         lov->lov_qos.lq_dirty = 1;
 111         lov->lov_qos.lq_rr.lqr_dirty = 1;
 112
 113         CDEBUG(D_QOS, "add tgt %s to OSS %s (%d OSTs)\n",
 114                obd_uuid2str(&lov->lov_tgts[index]->ltd_uuid),
 115                obd_uuid2str(&oss->lqo_uuid),
 116                oss->lqo_ost_count);
 117
 118 out:
 119         mutex_up(&lov->lov_lock);
 120         up_write(&lov->lov_qos.lq_rw_sem);
 121         RETURN(rc);
 122 }
 123
 124 int qos_del_tgt(struct obd_device *obd, __u32 index)
 125 {
 126         struct lov_obd *lov = &obd->u.lov;
 127         struct lov_qos_oss *oss;
 128         int rc = 0;
 129         ENTRY;
 130
 131         if (!lov->lov_tgts[index])
 132                 RETURN(0);
 133
 134         down_write(&lov->lov_qos.lq_rw_sem);
 135
 136         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
 137         if (!oss)
 138                 GOTO(out, rc = -ENOENT);
 139
 140         oss->lqo_ost_count--;
 141         if (oss->lqo_ost_count == 0) {
 142                 CDEBUG(D_QOS, "removing OSS %s\n",
 143                        obd_uuid2str(&oss->lqo_uuid));
 144                 list_del(&oss->lqo_oss_list);
 145                 OBD_FREE_PTR(oss);
 146         }
 147
 148         lov->lov_qos.lq_dirty = 1;
 149         lov->lov_qos.lq_rr.lqr_dirty = 1;
 150 out:
 151         up_write(&lov->lov_qos.lq_rw_sem);
 152         RETURN(rc);
 153 }
 154
 155 /* Recalculate per-object penalties for OSSs and OSTs,
 156    depends on size of each ost in an oss */
 157 static int qos_calc_ppo(struct obd_device *obd)
 158 {
 159         struct lov_obd *lov = &obd->u.lov;
 160         struct lov_qos_oss *oss;
 161         __u64 ba_max, ba_min, temp;
 162         __u32 num_active;
 163         int rc, i, prio_wide;
 164         ENTRY;
 165
 166         if (!lov->lov_qos.lq_dirty)
 167                 GOTO(out, rc = 0);
 168
 169         num_active = lov->desc.ld_active_tgt_count - 1;
 170         if (num_active < 1)
 171                 GOTO(out, rc = -EAGAIN);
 172
 173         /* find bavail on each OSS */
 174         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 175                 oss->lqo_bavail = 0;
 176         }
 177         lov->lov_qos.lq_active_oss_count = 0;
 178
 179         /* How badly user wants to select osts "widely" (not recently chosen
 180            and not on recent oss's).  As opposed to "freely" (free space
 181            avail.) 0-256. */
 182         prio_wide = 256 - lov->lov_qos.lq_prio_free;
 183
 184         ba_min = (__u64)(-1);
 185         ba_max = 0;
 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                 if (lov->lov_qos.lq_reset == 0)
 209                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
 210         }
 211
 212         num_active = lov->lov_qos.lq_active_oss_count - 1;
 213         if (num_active < 1) {
 214                 /* If there's only 1 OSS, we can't penalize it, so instead
 215                    we have to double the OST penalty */
 216                 num_active = 1;
 217                 for (i = 0; i < lov->desc.ld_tgt_count; i++) {
 218                         if (lov->lov_tgts[i] == NULL)
 219                                 continue;
 220                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj <<= 1;
 221                 }
 222         }
 223
 224         /* Per-OSS penalty is prio * oss_avail / oss_osts / (num_oss - 1) / 2 */
 225         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 226                 temp = oss->lqo_bavail >> 1;
 227                 do_div(temp, oss->lqo_ost_count * num_active);
 228                 oss->lqo_penalty_per_obj = (temp * prio_wide) >> 8;
 229                 if (lov->lov_qos.lq_reset == 0)
 230                         oss->lqo_penalty = 0;
 231         }
 232
 233         lov->lov_qos.lq_dirty = 0;
 234         lov->lov_qos.lq_reset = 0;
 235
 236         /* If each ost has almost same free space,
 237          * do rr allocation for better creation performance */
 238         lov->lov_qos.lq_same_space = 0;
 239         temp = ba_max - ba_min;
 240         ba_min = (ba_min * 51) >> 8;     /* 51/256 = .20 */
 241         if (temp < ba_min) {
 242                 /* Difference is less than 20% */
 243                 lov->lov_qos.lq_same_space = 1;
 244                 /* Reset weights for the next time we enter qos mode */
 245                 lov->lov_qos.lq_reset = 0;
 246         }
 247         rc = 0;
 248
 249 out:
 250         if (!rc && lov->lov_qos.lq_same_space)
 251                 RETURN(-EAGAIN);
 252         RETURN(rc);
 253 }
 254
 255 static int qos_calc_weight(struct lov_obd *lov, int i)
 256 {
 257         __u64 temp, temp2;
 258
 259         /* Final ost weight = TGT_BAVAIL - ost_penalty - oss_penalty */
 260         temp = TGT_BAVAIL(i);
 261         temp2 = lov->lov_tgts[i]->ltd_qos.ltq_penalty +
 262                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty;
 263         if (temp < temp2)
 264                 lov->lov_tgts[i]->ltd_qos.ltq_weight = 0;
 265         else
 266                 lov->lov_tgts[i]->ltd_qos.ltq_weight = temp - temp2;
 267         return 0;
 268 }
 269
 270 /* We just used this index for a stripe; adjust everyone's weights */
 271 static int qos_used(struct lov_obd *lov, struct ost_pool *osts,
 272                     __u32 index, __u64 *total_wt)
 273 {
 274         struct lov_qos_oss *oss;
 275         int j;
 276         ENTRY;
 277
 278         /* Don't allocate from this stripe anymore, until the next alloc_qos */
 279         lov->lov_tgts[index]->ltd_qos.ltq_usable = 0;
 280
 281         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
 282
 283         /* Decay old penalty by half (we're adding max penalty, and don't
 284            want it to run away.) */
 285         lov->lov_tgts[index]->ltd_qos.ltq_penalty >>= 1;
 286         oss->lqo_penalty >>= 1;
 287
 288         /* Set max penalties for this OST and OSS */
 289         lov->lov_tgts[index]->ltd_qos.ltq_penalty +=
 290                 lov->lov_tgts[index]->ltd_qos.ltq_penalty_per_obj *
 291                 lov->desc.ld_active_tgt_count;
 292         oss->lqo_penalty += oss->lqo_penalty_per_obj *
 293                 lov->lov_qos.lq_active_oss_count;
 294
 295         /* Decrease all OSS penalties */
 296         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 297                 if (oss->lqo_penalty < oss->lqo_penalty_per_obj)
 298                         oss->lqo_penalty = 0;
 299                 else
 300                         oss->lqo_penalty -= oss->lqo_penalty_per_obj;
 301         }
 302
 303         *total_wt = 0;
 304         /* Decrease all OST penalties */
 305         for (j = 0; j < osts->op_count; j++) {
 306                 int i;
 307
 308                 i = osts->op_array[j];
 309                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
 310                         continue;
 311                 if (lov->lov_tgts[i]->ltd_qos.ltq_penalty <
 312                     lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj)
 313                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
 314                 else
 315                         lov->lov_tgts[i]->ltd_qos.ltq_penalty -=
 316                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj;
 317
 318                 qos_calc_weight(lov, i);
 319
 320                 /* Recalc the total weight of usable osts */
 321                 if (lov->lov_tgts[i]->ltd_qos.ltq_usable)
 322                         *total_wt += lov->lov_tgts[i]->ltd_qos.ltq_weight;
 323
 324 #ifdef QOS_DEBUG
 325                 CDEBUG(D_QOS, "recalc tgt %d usable=%d avail="LPU64
 326                        " ostppo="LPU64" ostp="LPU64" ossppo="LPU64
 327                        " ossp="LPU64" wt="LPU64"\n",
 328                        i, lov->lov_tgts[i]->ltd_qos.ltq_usable,
 329                        TGT_BAVAIL(i) >> 10,
 330                        lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj >> 10,
 331                        lov->lov_tgts[i]->ltd_qos.ltq_penalty >> 10,
 332                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty_per_obj>>10,
 333                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty >> 10,
 334                        lov->lov_tgts[i]->ltd_qos.ltq_weight >> 10);
 335 #endif
 336         }
 337
 338         RETURN(0);
 339 }
 340
 341 #define LOV_QOS_EMPTY ((__u32)-1)
 342 /* compute optimal round-robin order, based on OSTs per OSS */
 343 static int qos_calc_rr(struct lov_obd *lov, struct ost_pool *src_pool,
 344                        struct lov_qos_rr *lqr)
 345 {
 346         struct lov_qos_oss *oss;
 347         unsigned placed, real_count;
 348         int i, rc;
 349         ENTRY;
 350
 351         if (!lqr->lqr_dirty) {
 352                 LASSERT(lqr->lqr_pool.op_size);
 353                 RETURN(0);
 354         }
 355
 356         /* Do actual allocation. */
 357         down_write(&lov->lov_qos.lq_rw_sem);
 358
 359         /*
 360          * Check again. While we were sleeping on @lq_rw_sem something could
 361          * change.
 362          */
 363         if (!lqr->lqr_dirty) {
 364                 LASSERT(lqr->lqr_pool.op_size);
 365                 up_write(&lov->lov_qos.lq_rw_sem);
 366                 RETURN(0);
 367         }
 368
 369         if (lqr->lqr_pool.op_size)
 370                 lov_ost_pool_free(&lqr->lqr_pool);
 371         rc = lov_ost_pool_init(&lqr->lqr_pool, src_pool->op_count);
 372         if (rc) {
 373                 up_write(&lov->lov_qos.lq_rw_sem);
 374                 RETURN(rc);
 375         }
 376
 377         for (i = 0; i < src_pool->op_count; i++)
 378                 lqr->lqr_pool.op_array[i] = LOV_QOS_EMPTY;
 379         lqr->lqr_pool.op_count = src_pool->op_count;
 380
 381         /* Place all the OSTs from 1 OSS at the same time. */
 382         real_count = lqr->lqr_pool.op_count;
 383         placed = 0;
 384         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 385                 int j = 0;
 386                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
 387                         if (lov->lov_tgts[src_pool->op_array[i]] &&
 388                             (lov->lov_tgts[src_pool->op_array[i]]->ltd_qos.ltq_oss == oss)) {
 389                               /* Evenly space these OSTs across arrayspace */
 390                               int next = j * lqr->lqr_pool.op_count / oss->lqo_ost_count;
 391                               while (lqr->lqr_pool.op_array[next] !=
 392                                      LOV_QOS_EMPTY)
 393                                         next = (next + 1) % lqr->lqr_pool.op_count;
 394                               lqr->lqr_pool.op_array[next] = src_pool->op_array[i];
 395                               j++;
 396                               placed++;
 397                         }
 398                 }
 399         }
 400
 401         lqr->lqr_dirty = 0;
 402         up_write(&lov->lov_qos.lq_rw_sem);
 403
 404         if (placed != real_count) {
 405                 /* This should never happen */
 406                 LCONSOLE_ERROR_MSG(0x14e, "Failed to place all OSTs in the "
 407                                    "round-robin list (%d of %d).\n",
 408                                    placed, real_count);
 409                 for (i = 0; i < lqr->lqr_pool.op_count; i++) {
 410                         LCONSOLE(D_WARNING, "rr #%d ost idx=%d\n", i,
 411                                  lqr->lqr_pool.op_array[i]);
 412                 }
 413                 lqr->lqr_dirty = 1;
 414                 RETURN(-EAGAIN);
 415         }
 416
 417 #ifdef QOS_DEBUG
 418         for (i = 0; i < lqr->lqr_pool.op_count; i++) {
 419                 LCONSOLE(D_QOS, "rr #%d ost idx=%d\n", i,
 420                          lqr->lqr_pool.op_array[i]);
 421         }
 422 #endif
 423
 424         RETURN(0);
 425 }
 426
 427
 428 void qos_shrink_lsm(struct lov_request_set *set)
 429 {
 430         struct lov_stripe_md *lsm = set->set_oi->oi_md, *lsm_new;
 431         /* XXX LOV STACKING call into osc for sizes */
 432         unsigned oldsize, newsize;
 433
 434         if (set->set_oti && set->set_cookies && set->set_cookie_sent) {
 435                 struct llog_cookie *cookies;
 436                 oldsize = lsm->lsm_stripe_count * sizeof(*cookies);
 437                 newsize = set->set_count * sizeof(*cookies);
 438
 439                 cookies = set->set_cookies;
 440                 oti_alloc_cookies(set->set_oti, set->set_count);
 441                 if (set->set_oti->oti_logcookies) {
 442                         memcpy(set->set_oti->oti_logcookies, cookies, newsize);
 443                         OBD_FREE(cookies, oldsize);
 444                         set->set_cookies = set->set_oti->oti_logcookies;
 445                 } else {
 446                         CWARN("'leaking' %d bytes\n", oldsize - newsize);
 447                 }
 448         }
 449
 450         CWARN("using fewer stripes for object "LPU64": old %u new %u\n",
 451               lsm->lsm_object_id, lsm->lsm_stripe_count, set->set_count);
 452         LASSERT(lsm->lsm_stripe_count >= set->set_count);
 453
 454         newsize = lov_stripe_md_size(set->set_count);
 455         OBD_ALLOC(lsm_new, newsize);
 456         if (lsm_new != NULL) {
 457                 int i;
 458                 memcpy(lsm_new, lsm, sizeof(*lsm));
 459                 for (i = 0; i < lsm->lsm_stripe_count; i++) {
 460                         if (i < set->set_count) {
 461                                 lsm_new->lsm_oinfo[i] = lsm->lsm_oinfo[i];
 462                                 continue;
 463                         }
 464                         OBD_SLAB_FREE(lsm->lsm_oinfo[i], lov_oinfo_slab,
 465                                       sizeof(struct lov_oinfo));
 466                 }
 467                 lsm_new->lsm_stripe_count = set->set_count;
 468                 OBD_FREE(lsm, sizeof(struct lov_stripe_md) +
 469                          lsm->lsm_stripe_count * sizeof(struct lov_oinfo *));
 470                 set->set_oi->oi_md = lsm_new;
 471         } else {
 472                 CWARN("'leaking' few bytes\n");
 473         }
 474 }
 475
 476 int qos_remedy_create(struct lov_request_set *set, struct lov_request *req)
 477 {
 478         struct lov_stripe_md *lsm = set->set_oi->oi_md;
 479         struct lov_obd *lov = &set->set_exp->exp_obd->u.lov;
 480         unsigned ost_idx, ost_count = lov->desc.ld_tgt_count;
 481         int stripe, i, rc = -EIO;
 482         ENTRY;
 483
 484         ost_idx = (req->rq_idx + lsm->lsm_stripe_count) % ost_count;
 485         for (i = 0; i < ost_count; i++, ost_idx = (ost_idx + 1) % ost_count) {
 486                 if (!lov->lov_tgts[ost_idx] ||
 487                     !lov->lov_tgts[ost_idx]->ltd_active)
 488                         continue;
 489                 /* check if objects has been created on this ost */
 490                 for (stripe = 0; stripe < lsm->lsm_stripe_count; stripe++) {
 491                         if (stripe == req->rq_stripe)
 492                                 continue;
 493                         if (ost_idx == lsm->lsm_oinfo[stripe]->loi_ost_idx)
 494                                 break;
 495                 }
 496
 497                 if (stripe >= lsm->lsm_stripe_count) {
 498                         req->rq_idx = ost_idx;
 499                         rc = obd_create(lov->lov_tgts[ost_idx]->ltd_exp,
 500                                         req->rq_oi.oi_oa, &req->rq_oi.oi_md,
 501                                         set->set_oti);
 502                         if (!rc)
 503                                 break;
 504                 }
 505         }
 506         RETURN(rc);
 507 }
 508
 509 static int min_stripe_count(int stripe_cnt, int flags)
 510 {
 511         return (flags & LOV_USES_DEFAULT_STRIPE ?
 512                 stripe_cnt - (stripe_cnt / 4) : stripe_cnt);
 513 }
 514
 515 #define LOV_CREATE_RESEED_MULT 4
 516 #define LOV_CREATE_RESEED_MIN  1000
 517 /* Allocate objects on osts with round-robin algorithm */
 518 static int alloc_rr(struct lov_obd *lov, int *idx_arr, int *stripe_cnt,
 519                     char *poolname, int flags)
 520 {
 521         unsigned array_idx;
 522         int i, *idx_pos;
 523         __u32 ost_idx;
 524         int ost_start_idx_temp;
 525         int speed = 0;
 526         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
 527         struct pool_desc *pool;
 528         struct ost_pool *osts;
 529         struct lov_qos_rr *lqr;
 530         ENTRY;
 531
 532         pool = lov_find_pool(lov, poolname);
 533         if (pool == NULL) {
 534                 osts = &(lov->lov_packed);
 535                 lqr = &(lov->lov_qos.lq_rr);
 536         } else {
 537                 read_lock(&pool_tgt_rwlock(pool));
 538                 osts = &(pool->pool_obds);
 539                 lqr = &(pool->pool_rr);
 540         }
 541
 542         i = qos_calc_rr(lov, osts, lqr);
 543         if (i) {
 544                 if (pool != NULL)
 545                         read_unlock(&pool_tgt_rwlock(pool));
 546                 RETURN(i);
 547         }
 548
 549         if (--lqr->lqr_start_count <= 0) {
 550                 lqr->lqr_start_idx = ll_rand() % osts->op_count;
 551                 lqr->lqr_start_count =
 552                         (LOV_CREATE_RESEED_MIN / max(osts->op_count, 1U) +
 553                          LOV_CREATE_RESEED_MULT) * max(osts->op_count, 1U);
 554         } else if (stripe_cnt_min >= osts->op_count ||
 555                    lqr->lqr_start_idx > osts->op_count) {
 556                 /* If we have allocated from all of the OSTs, slowly
 557                  * precess the next start if the OST/stripe count isn't
 558                  * already doing this for us. */
 559                 lqr->lqr_start_idx %= osts->op_count;
 560                 if (*stripe_cnt > 1 && (osts->op_count % (*stripe_cnt)) != 1)
 561                         ++lqr->lqr_offset_idx;
 562         }
 563         down_read(&lov->lov_qos.lq_rw_sem);
 564         ost_start_idx_temp = lqr->lqr_start_idx;
 565
 566 repeat_find:
 567         array_idx = (lqr->lqr_start_idx + lqr->lqr_offset_idx) % osts->op_count;
 568         idx_pos = idx_arr;
 569 #ifdef QOS_DEBUG
 570         CDEBUG(D_QOS, "pool '%s' want %d startidx %d startcnt %d offset %d "
 571                "active %d count %d arrayidx %d\n", poolname,
 572                *stripe_cnt, lqr->lqr_start_idx, lqr->lqr_start_count,
 573                lqr->lqr_offset_idx, osts->op_count, osts->op_count, array_idx);
 574 #endif
 575
 576         for (i = 0; i < osts->op_count;
 577                     i++, array_idx=(array_idx + 1) % osts->op_count) {
 578                 ++lqr->lqr_start_idx;
 579                 ost_idx = lqr->lqr_pool.op_array[array_idx];
 580 #ifdef QOS_DEBUG
 581                 CDEBUG(D_QOS, "#%d strt %d act %d strp %d ary %d idx %d\n",
 582                        i, lqr->lqr_start_idx,
 583                        ((ost_idx != LOV_QOS_EMPTY) && lov->lov_tgts[ost_idx]) ?
 584                        lov->lov_tgts[ost_idx]->ltd_active : 0,
 585                        idx_pos - idx_arr, array_idx, ost_idx);
 586 #endif
 587                 if ((ost_idx == LOV_QOS_EMPTY) || !lov->lov_tgts[ost_idx] ||
 588                     !lov->lov_tgts[ost_idx]->ltd_active)
 589                         continue;
 590
 591                 /* Fail Check before osc_precreate() is called
 592                    so we can only 'fail' single OSC. */
 593                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
 594                         continue;
 595
 596                 /* Drop slow OSCs if we can */
 597                 if (obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed)
 598                         continue;
 599
 600                 *idx_pos = ost_idx;
 601                 idx_pos++;
 602                 /* We have enough stripes */
 603                 if (idx_pos - idx_arr == *stripe_cnt)
 604                         break;
 605         }
 606         if ((speed < 2) && (idx_pos - idx_arr < stripe_cnt_min)) {
 607                 /* Try again, allowing slower OSCs */
 608                 speed++;
 609                 lqr->lqr_start_idx = ost_start_idx_temp;
 610                 goto repeat_find;
 611         }
 612
 613         if (pool != NULL)
 614                 read_unlock(&pool_tgt_rwlock(pool));
 615
 616         up_read(&lov->lov_qos.lq_rw_sem);
 617
 618         *stripe_cnt = idx_pos - idx_arr;
 619         RETURN(0);
 620 }
 621
 622 /* alloc objects on osts with specific stripe offset */
 623 static int alloc_specific(struct lov_obd *lov, struct lov_stripe_md *lsm,
 624                           int *idx_arr)
 625 {
 626         unsigned ost_idx, array_idx, ost_count;
 627         int i, *idx_pos;
 628         int speed = 0;
 629         struct pool_desc *pool = NULL;
 630         struct ost_pool *osts;
 631         ENTRY;
 632
 633         pool = lov_find_pool(lov, lsm->lsm_pool_name);
 634         if (pool == NULL) {
 635                 osts = &(lov->lov_packed);
 636         } else {
 637                 read_lock(&pool_tgt_rwlock(pool));
 638                 osts = &(pool->pool_obds);
 639         }
 640
 641         ost_count = osts->op_count;
 642
 643 repeat_find:
 644         /* search loi_ost_idx in ost array */
 645         array_idx = 0;
 646         for (i = 0; i < ost_count; i++) {
 647                 if (osts->op_array[i] == lsm->lsm_oinfo[0]->loi_ost_idx) {
 648                         array_idx = i;
 649                         break;
 650                 }
 651         }
 652         if (i == ost_count) {
 653                 if (pool != NULL)
 654                         read_unlock(&pool_tgt_rwlock(pool));
 655                 CERROR("Start index %d not found in pool '%s'\n",
 656                        lsm->lsm_oinfo[0]->loi_ost_idx, lsm->lsm_pool_name);
 657                 RETURN(-EINVAL);
 658         }
 659
 660         idx_pos = idx_arr;
 661         for (i = 0; i < ost_count;
 662              i++, array_idx = (array_idx + 1) % ost_count) {
 663                 ost_idx = osts->op_array[array_idx];
 664
 665                 if (!lov->lov_tgts[ost_idx] ||
 666                     !lov->lov_tgts[ost_idx]->ltd_active) {
 667                         continue;
 668                 }
 669
 670                 /* Fail Check before osc_precreate() is called
 671                    so we can only 'fail' single OSC. */
 672                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && ost_idx == 0)
 673                         continue;
 674
 675                 /* Drop slow OSCs if we can, but not for requested start idx */
 676                 if ((obd_precreate(lov->lov_tgts[ost_idx]->ltd_exp) > speed) &&
 677                     (i != 0 || speed < 2))
 678                         continue;
 679
 680                 *idx_pos = ost_idx;
 681                 idx_pos++;
 682                 /* We have enough stripes */
 683                 if (idx_pos - idx_arr == lsm->lsm_stripe_count) {
 684                         if (pool != NULL)
 685                                 read_unlock(&pool_tgt_rwlock(pool));
 686                         RETURN(0);
 687                 }
 688         }
 689         if (speed < 2) {
 690                 /* Try again, allowing slower OSCs */
 691                 speed++;
 692                 goto repeat_find;
 693         }
 694
 695         /* If we were passed specific striping params, then a failure to
 696          * meet those requirements is an error, since we can't reallocate
 697          * that memory (it might be part of a larger array or something).
 698          *
 699          * We can only get here if lsm_stripe_count was originally > 1.
 700          */
 701         CERROR("can't lstripe objid "LPX64": have %d want %u\n",
 702                lsm->lsm_object_id, (int)(idx_pos - idx_arr),
 703                lsm->lsm_stripe_count);
 704
 705         if (pool != NULL)
 706                 read_unlock(&pool_tgt_rwlock(pool));
 707
 708         RETURN(-EFBIG);
 709 }
 710
 711 /* Alloc objects on osts with optimization based on:
 712    - free space
 713    - network resources (shared OSS's)
 714 */
 715 static int alloc_qos(struct obd_export *exp, int *idx_arr, int *stripe_cnt,
 716                      char *poolname, int flags)
 717 {
 718         struct lov_obd *lov = &exp->exp_obd->u.lov;
 719         static time_t last_warn = 0;
 720         time_t now = cfs_time_current_sec();
 721         __u64 total_bavail, total_weight = 0;
 722         int nfound, good_osts, i, warn = 0, rc = 0;
 723         int stripe_cnt_min = min_stripe_count(*stripe_cnt, flags);
 724         struct pool_desc *pool;
 725         struct ost_pool *osts;
 726         struct lov_qos_rr *lqr;
 727         ENTRY;
 728
 729         if (stripe_cnt_min < 1)
 730                 GOTO(out_nolock, rc = -EINVAL);
 731
 732         pool = lov_find_pool(lov, poolname);
 733         if (pool == NULL) {
 734                 osts = &(lov->lov_packed);
 735                 lqr = &(lov->lov_qos.lq_rr);
 736         } else {
 737                 read_lock(&pool_tgt_rwlock(pool));
 738                 osts = &(pool->pool_obds);
 739                 lqr = &(pool->pool_rr);
 740         }
 741
 742         lov_getref(exp->exp_obd);
 743
 744         /* Detect -EAGAIN early, before expensive lock is taken. */
 745         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
 746                 GOTO(out_nolock, rc = -EAGAIN);
 747
 748         /* Do actual allocation, use write lock here. */
 749         down_write(&lov->lov_qos.lq_rw_sem);
 750
 751         /*
 752          * Check again, while we were sleeping on @lq_rw_sem things could
 753          * change.
 754          */
 755         if (!lov->lov_qos.lq_dirty && lov->lov_qos.lq_same_space)
 756                 GOTO(out, rc = -EAGAIN);
 757
 758         if (lov->desc.ld_active_tgt_count < 2)
 759                 GOTO(out, rc = -EAGAIN);
 760
 761         rc = qos_calc_ppo(exp->exp_obd);
 762         if (rc)
 763                 GOTO(out, rc);
 764
 765         total_bavail = 0;
 766         good_osts = 0;
 767         /* Warn users about zero available space/inode every 30 min */
 768         if (cfs_time_sub(now, last_warn) > 60 * 30)
 769                 warn = 1;
 770         /* Find all the OSTs that are valid stripe candidates */
 771         for (i = 0; i < osts->op_count; i++) {
 772                 __u64 bavail;
 773
 774                 if (!lov->lov_tgts[osts->op_array[i]] ||
 775                     !lov->lov_tgts[osts->op_array[i]]->ltd_active)
 776                         continue;
 777                 bavail = TGT_BAVAIL(osts->op_array[i]);
 778                 if (!bavail) {
 779                         if (warn) {
 780                                 CDEBUG(D_QOS, "no free space on %s\n",
 781                                      obd_uuid2str(&lov->lov_tgts[osts->op_array[i]]->ltd_uuid));
 782                                 last_warn = now;
 783                         }
 784                         continue;
 785                 }
 786                 if (!TGT_FFREE(osts->op_array[i])) {
 787                         if (warn) {
 788                                 CDEBUG(D_QOS, "no free inodes on %s\n",
 789                                      obd_uuid2str(&lov->lov_tgts[osts->op_array[i]]->ltd_uuid));
 790                                 last_warn = now;
 791                         }
 792                         continue;
 793                 }
 794
 795                 /* Fail Check before osc_precreate() is called
 796                    so we can only 'fail' single OSC. */
 797                 if (OBD_FAIL_CHECK(OBD_FAIL_MDS_OSC_PRECREATE) && osts->op_array[i] == 0)
 798                         continue;
 799
 800                 if (obd_precreate(lov->lov_tgts[osts->op_array[i]]->ltd_exp) > 2)
 801                         continue;
 802
 803                 lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable = 1;
 804                 qos_calc_weight(lov, osts->op_array[i]);
 805                 total_bavail += bavail;
 806                 total_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
 807
 808                 good_osts++;
 809         }
 810
 811 #ifdef QOS_DEBUG
 812         CDEBUG(D_QOS, "found %d good osts\n", good_osts);
 813 #endif
 814
 815         if (good_osts < stripe_cnt_min)
 816                 GOTO(out, rc = -EAGAIN);
 817
 818         if (!total_bavail)
 819                 GOTO(out, rc = -ENOSPC);
 820
 821         /* We have enough osts */
 822         if (good_osts < *stripe_cnt)
 823                 *stripe_cnt = good_osts;
 824
 825         if (!*stripe_cnt)
 826                 GOTO(out, rc = -EAGAIN);
 827
 828         /* Find enough OSTs with weighted random allocation. */
 829         nfound = 0;
 830         while (nfound < *stripe_cnt) {
 831                 __u64 rand, cur_weight;
 832
 833                 cur_weight = 0;
 834                 rc = -ENODEV;
 835
 836                 if (total_weight) {
 837 #if BITS_PER_LONG == 32
 838                         rand = ll_rand() % (unsigned)total_weight;
 839                         /* If total_weight > 32-bit, first generate the high
 840                          * 32 bits of the random number, then add in the low
 841                          * 32 bits (truncated to the upper limit, if needed) */
 842                         if (total_weight > 0xffffffffULL)
 843                                 rand = (__u64)(ll_rand() %
 844                                           (unsigned)(total_weight >> 32)) << 32;
 845                         else
 846                                 rand = 0;
 847
 848                         if (rand == (total_weight & 0xffffffff00000000ULL))
 849                                 rand |= ll_rand() % (unsigned)total_weight;
 850                         else
 851                                 rand |= ll_rand();
 852
 853 #else
 854                         rand = ((__u64)ll_rand() << 32 | ll_rand()) %
 855                                 total_weight;
 856 #endif
 857                 } else {
 858                         rand = 0;
 859                 }
 860
 861                 /* On average, this will hit larger-weighted osts more often.
 862                    0-weight osts will always get used last (only when rand=0).*/
 863                 for (i = 0; i < osts->op_count; i++) {
 864                         if (!lov->lov_tgts[osts->op_array[i]] ||
 865                             !lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_usable)
 866                                 continue;
 867
 868                         cur_weight += lov->lov_tgts[osts->op_array[i]]->ltd_qos.ltq_weight;
 869 #ifdef QOS_DEBUG
 870                         CDEBUG(D_QOS, "stripe_cnt=%d nfound=%d cur_weight="LPU64
 871                                       " rand="LPU64" total_weight="LPU64"\n",
 872                                *stripe_cnt, nfound, cur_weight, rand, total_weight);
 873 #endif
 874                         if (cur_weight >= rand) {
 875 #ifdef QOS_DEBUG
 876                                 CDEBUG(D_QOS, "assigned stripe=%d to idx=%d\n",
 877                                        nfound, osts->op_array[i]);
 878 #endif
 879                                 idx_arr[nfound++] = osts->op_array[i];
 880                                 qos_used(lov, osts, osts->op_array[i], &total_weight);
 881                                 rc = 0;
 882                                 break;
 883                         }
 884                 }
 885                 /* should never satisfy below condition */
 886                 if (rc) {
 887                         CERROR("Didn't find any OSTs?\n");
 888                         break;
 889                 }
 890         }
 891         LASSERT(nfound == *stripe_cnt);
 892
 893 out:
 894         if (pool != NULL)
 895                 read_unlock(&pool_tgt_rwlock(pool));
 896
 897         up_write(&lov->lov_qos.lq_rw_sem);
 898
 899 out_nolock:
 900         if (rc == -EAGAIN)
 901                 rc = alloc_rr(lov, idx_arr, stripe_cnt, poolname, flags);
 902
 903         lov_putref(exp->exp_obd);
 904         RETURN(rc);
 905 }
 906
 907 /* return new alloced stripe count on success */
 908 static int alloc_idx_array(struct obd_export *exp, struct lov_stripe_md *lsm,
 909                            int newea, int **idx_arr, int *arr_cnt, int flags)
 910 {
 911         struct lov_obd *lov = &exp->exp_obd->u.lov;
 912         int stripe_cnt = lsm->lsm_stripe_count;
 913         int i, rc = 0;
 914         int *tmp_arr = NULL;
 915         ENTRY;
 916
 917         *arr_cnt = stripe_cnt;
 918         OBD_ALLOC(tmp_arr, *arr_cnt * sizeof(int));
 919         if (tmp_arr == NULL)
 920                 RETURN(-ENOMEM);
 921         for (i = 0; i < *arr_cnt; i++)
 922                 tmp_arr[i] = -1;
 923
 924         if (newea ||
 925             lsm->lsm_oinfo[0]->loi_ost_idx >= lov->desc.ld_tgt_count)
 926                 rc = alloc_qos(exp, tmp_arr, &stripe_cnt,
 927                                lsm->lsm_pool_name, flags);
 928         else
 929                 rc = alloc_specific(lov, lsm, tmp_arr);
 930
 931         if (rc)
 932                 GOTO(out_arr, rc);
 933
 934         *idx_arr = tmp_arr;
 935         RETURN(stripe_cnt);
 936 out_arr:
 937         OBD_FREE(tmp_arr, *arr_cnt * sizeof(int));
 938         *arr_cnt = 0;
 939         RETURN(rc);
 940 }
 941
 942 static void free_idx_array(int *idx_arr, int arr_cnt)
 943 {
 944         if (arr_cnt)
 945                 OBD_FREE(idx_arr, arr_cnt * sizeof(int));
 946 }
 947
 948 int qos_prep_create(struct obd_export *exp, struct lov_request_set *set)
 949 {
 950         struct lov_obd *lov = &exp->exp_obd->u.lov;
 951         struct lov_stripe_md *lsm;
 952         struct obdo *src_oa = set->set_oi->oi_oa;
 953         struct obd_trans_info *oti = set->set_oti;
 954         int i, stripes, rc = 0, newea = 0;
 955         int flag = LOV_USES_ASSIGNED_STRIPE;
 956         int *idx_arr = NULL, idx_cnt = 0;
 957         ENTRY;
 958
 959         LASSERT(src_oa->o_valid & OBD_MD_FLID);
 960         LASSERT(src_oa->o_valid & OBD_MD_FLGROUP);
 961
 962         if (set->set_oi->oi_md == NULL) {
 963                 int stripes_def = lov_get_stripecnt(lov, 0);
 964
 965                 /* If the MDS file was truncated up to some size, stripe over
 966                  * enough OSTs to allow the file to be created at that size.
 967                  * This may mean we use more than the default # of stripes. */
 968                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
 969                         obd_size min_bavail = LUSTRE_STRIPE_MAXBYTES;
 970
 971                         /* Find a small number of stripes we can use
 972                            (up to # of active osts). */
 973                         stripes = 1;
 974                         lov_getref(exp->exp_obd);
 975                         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
 976                                 if (!lov->lov_tgts[i] ||
 977                                     !lov->lov_tgts[i]->ltd_active)
 978                                         continue;
 979                                 min_bavail = min(min_bavail, TGT_BAVAIL(i));
 980                                 if (min_bavail * stripes > src_oa->o_size)
 981                                         break;
 982                                 stripes++;
 983                         }
 984                         lov_putref(exp->exp_obd);
 985
 986                         if (stripes < stripes_def)
 987                                 stripes = stripes_def;
 988                 } else {
 989                          flag = LOV_USES_DEFAULT_STRIPE;
 990                          stripes = stripes_def;
 991                 }
 992
 993                 rc = lov_alloc_memmd(&set->set_oi->oi_md, stripes,
 994                                      lov->desc.ld_pattern ?
 995                                      lov->desc.ld_pattern : LOV_PATTERN_RAID0,
 996                                      LOV_MAGIC);
 997                 if (rc < 0)
 998                         GOTO(out_err, rc);
 999                 newea = 1;
1000                 rc = 0;
1001         }
1002
1003         lsm = set->set_oi->oi_md;
1004         lsm->lsm_object_id = src_oa->o_id;
1005         lsm->lsm_object_gr = src_oa->o_gr;
1006
1007         if (!lsm->lsm_stripe_size)
1008                 lsm->lsm_stripe_size = lov->desc.ld_default_stripe_size;
1009         if (!lsm->lsm_pattern) {
1010                 LASSERT(lov->desc.ld_pattern);
1011                 lsm->lsm_pattern = lov->desc.ld_pattern;
1012         }
1013
1014         stripes = alloc_idx_array(exp, lsm, newea, &idx_arr, &idx_cnt, flag);
1015         if (stripes <= 0)
1016                 GOTO(out_err, rc = stripes ? stripes : -EIO);
1017         LASSERTF(stripes <= lsm->lsm_stripe_count,"requested %d allocated %d\n",
1018                  lsm->lsm_stripe_count, stripes);
1019
1020         for (i = 0; i < stripes; i++) {
1021                 struct lov_request *req;
1022                 int ost_idx = idx_arr[i];
1023                 LASSERT(ost_idx >= 0);
1024
1025                 OBD_ALLOC(req, sizeof(*req));
1026                 if (req == NULL)
1027                         GOTO(out_err, rc = -ENOMEM);
1028                 lov_set_add_req(req, set);
1029
1030                 req->rq_buflen = sizeof(*req->rq_oi.oi_md);
1031                 OBD_ALLOC(req->rq_oi.oi_md, req->rq_buflen);
1032                 if (req->rq_oi.oi_md == NULL)
1033                         GOTO(out_err, rc = -ENOMEM);
1034
1035                 OBDO_ALLOC(req->rq_oi.oi_oa);
1036                 if (req->rq_oi.oi_oa == NULL)
1037                         GOTO(out_err, rc = -ENOMEM);
1038
1039                 req->rq_idx = ost_idx;
1040                 req->rq_stripe = i;
1041                 /* create data objects with "parent" OA */
1042                 memcpy(req->rq_oi.oi_oa, src_oa, sizeof(*req->rq_oi.oi_oa));
1043
1044                 /* XXX When we start creating objects on demand, we need to
1045                  *     make sure that we always create the object on the
1046                  *     stripe which holds the existing file size.
1047                  */
1048                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
1049                         req->rq_oi.oi_oa->o_size =
1050                                 lov_size_to_stripe(lsm, src_oa->o_size, i);
1051
1052                         CDEBUG(D_INODE, "stripe %d has size "LPU64"/"LPU64"\n",
1053                                i, req->rq_oi.oi_oa->o_size, src_oa->o_size);
1054                 }
1055         }
1056         LASSERT(set->set_count == stripes);
1057
1058         if (stripes < lsm->lsm_stripe_count)
1059                 qos_shrink_lsm(set);
1060
1061         if (oti && (src_oa->o_valid & OBD_MD_FLCOOKIE)) {
1062                 oti_alloc_cookies(oti, set->set_count);
1063                 if (!oti->oti_logcookies)
1064                         GOTO(out_err, rc = -ENOMEM);
1065                 set->set_cookies = oti->oti_logcookies;
1066         }
1067 out_err:
1068         if (newea && rc)
1069                 obd_free_memmd(exp, &set->set_oi->oi_md);
1070         if (idx_arr)
1071                 free_idx_array(idx_arr, idx_cnt);
1072         EXIT;
1073         return rc;
1074 }
1075
1076 void qos_update(struct lov_obd *lov)
1077 {
1078         ENTRY;
1079         lov->lov_qos.lq_dirty = 1;
1080 }