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  * Copyright (C) 2002, 2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of the Lustre file system, http://www.lustre.org
   7  *   Lustre is a trademark of Cluster File Systems, Inc.
   8  *
   9  *   You may have signed or agreed to another license before downloading
  10  *   this software.  If so, you are bound by the terms and conditions
  11  *   of that agreement, and the following does not apply to you.  See the
  12  *   LICENSE file included with this distribution for more information.
  13  *
  14  *   If you did not agree to a different license, then this copy of Lustre
  15  *   is open source software; you can redistribute it and/or modify it
  16  *   under the terms of version 2 of the GNU General Public License as
  17  *   published by the Free Software Foundation.
  18  *
  19  *   In either case, Lustre is distributed in the hope that it will be
  20  *   useful, but WITHOUT ANY WARRANTY; without even the implied warranty
  21  *   of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  22  *   license text for more details.
  23  */
  24
  25 #ifndef EXPORT_SYMTAB
  26 # define EXPORT_SYMTAB
  27 #endif
  28 #define DEBUG_SUBSYSTEM S_LOV
  29
  30 #ifdef __KERNEL__
  31 #include <libcfs/libcfs.h>
  32 #else
  33 #include <liblustre.h>
  34 #endif
  35
  36 #include <obd_class.h>
  37 #include <obd_lov.h>
  38 #include "lov_internal.h"
  39
  40
  41 /* #define QOS_DEBUG 1 */
  42 #define D_QOS D_OTHER
  43
  44 #define TGT_BAVAIL(i)  (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bavail * \
  45                         lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_bsize)
  46 #define TGT_FFREE(i)   (lov->lov_tgts[i]->ltd_exp->exp_obd->obd_osfs.os_ffree)
  47
  48
  49 int qos_add_tgt(struct obd_device *obd, __u32 index)
  50 {
  51         struct lov_obd *lov = &obd->u.lov;
  52         struct lov_qos_oss *oss, *temposs;
  53         struct obd_export *exp = lov->lov_tgts[index]->ltd_exp;
  54         int rc = 0, found = 0;
  55         ENTRY;
  56
  57         /* We only need this QOS struct on MDT, not clients - but we may not
  58            have registered the lov's observer yet, so there's no way to check
  59            here. */
  60
  61         if (!exp || !exp->exp_connection) {
  62                 CERROR("Missing connection\n");
  63                 RETURN(-ENOTCONN);
  64         }
  65
  66         down_write(&lov->lov_qos.lq_rw_sem);
  67         mutex_down(&lov->lov_lock);
  68         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
  69                 if (obd_uuid_equals(&oss->lqo_uuid,
  70                                     &exp->exp_connection->c_remote_uuid)) {
  71                         found++;
  72                         break;
  73                 }
  74         }
  75
  76         if (!found) {
  77                 OBD_ALLOC_PTR(oss);
  78                 if (!oss)
  79                         GOTO(out, rc = -ENOMEM);
  80                 memcpy(&oss->lqo_uuid,
  81                        &exp->exp_connection->c_remote_uuid,
  82                        sizeof(oss->lqo_uuid));
  83         } else {
  84                 /* Assume we have to move this one */
  85                 list_del(&oss->lqo_oss_list);
  86         }
  87
  88         oss->lqo_ost_count++;
  89         lov->lov_tgts[index]->ltd_qos.ltq_oss = oss;
  90
  91         /* Add sorted by # of OSTs.  Find the first entry that we're
  92            bigger than... */
  93         list_for_each_entry(temposs, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
  94                 if (oss->lqo_ost_count > temposs->lqo_ost_count)
  95                         break;
  96         }
  97         /* ...and add before it.  If we're the first or smallest, temposs
  98            points to the list head, and we add to the end. */
  99         list_add_tail(&oss->lqo_oss_list, &temposs->lqo_oss_list);
 100
 101         lov->lov_qos.lq_dirty = 1;
 102         lov->lov_qos.lq_dirty_rr = 1;
 103
 104         CDEBUG(D_QOS, "add tgt %s to OSS %s (%d OSTs)\n",
 105                obd_uuid2str(&lov->lov_tgts[index]->ltd_uuid),
 106                obd_uuid2str(&oss->lqo_uuid),
 107                oss->lqo_ost_count);
 108
 109 out:
 110         mutex_up(&lov->lov_lock);
 111         up_write(&lov->lov_qos.lq_rw_sem);
 112         RETURN(rc);
 113 }
 114
 115 int qos_del_tgt(struct obd_device *obd, __u32 index)
 116 {
 117         struct lov_obd *lov = &obd->u.lov;
 118         struct lov_qos_oss *oss;
 119         int rc = 0;
 120         ENTRY;
 121
 122         down_write(&lov->lov_qos.lq_rw_sem);
 123
 124         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
 125         if (!oss)
 126                 GOTO(out, rc = -ENOENT);
 127
 128         oss->lqo_ost_count--;
 129         if (oss->lqo_ost_count == 0) {
 130                 CDEBUG(D_QOS, "removing OSS %s\n",
 131                        obd_uuid2str(&oss->lqo_uuid));
 132                 list_del(&oss->lqo_oss_list);
 133                 OBD_FREE_PTR(oss);
 134         }
 135
 136         lov->lov_qos.lq_dirty = 1;
 137         lov->lov_qos.lq_dirty_rr = 1;
 138 out:
 139         up_write(&lov->lov_qos.lq_rw_sem);
 140         RETURN(rc);
 141 }
 142
 143 /* Recalculate per-object penalties for OSSs and OSTs,
 144    depends on size of each ost in an oss */
 145 static int qos_calc_ppo(struct obd_device *obd)
 146 {
 147         struct lov_obd *lov = &obd->u.lov;
 148         struct lov_qos_oss *oss;
 149         __u64 ba_max, ba_min, temp;
 150         __u32 num_active;
 151         int rc, i, prio_wide;
 152         ENTRY;
 153
 154         if (!lov->lov_qos.lq_dirty)
 155                 GOTO(out, rc = 0);
 156
 157         num_active = lov->desc.ld_active_tgt_count - 1;
 158         if (num_active < 1)
 159                 GOTO(out, rc = -EAGAIN);
 160
 161         /* find bavail on each OSS */
 162         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 163                 oss->lqo_bavail = 0;
 164         }
 165         lov->lov_qos.lq_active_oss_count = 0;
 166
 167         /* How badly user wants to select osts "widely" (not recently chosen
 168            and not on recent oss's).  As opposed to "freely" (free space
 169            avail.) 0-256. */
 170         prio_wide = 256 - lov->lov_qos.lq_prio_free;
 171
 172         ba_min = (__u64)(-1);
 173         ba_max = 0;
 174         /* Calculate OST penalty per object */
 175         /* (lov ref taken in alloc_qos) */
 176         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
 177                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
 178                         continue;
 179                 temp = TGT_BAVAIL(i);
 180                 if (!temp)
 181                         continue;
 182                 ba_min = min(temp, ba_min);
 183                 ba_max = max(temp, ba_max);
 184
 185                 /* Count the number of usable OSS's */
 186                 if (lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail == 0)
 187                         lov->lov_qos.lq_active_oss_count++;
 188                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_bavail += temp;
 189
 190                 /* per-OST penalty is prio * TGT_bavail / (num_ost - 1) / 2 */
 191                 temp >>= 1;
 192                 do_div(temp, num_active);
 193                 lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj =
 194                         (temp * prio_wide) >> 8;
 195
 196                 if (lov->lov_qos.lq_reset == 0)
 197                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
 198         }
 199
 200         num_active = lov->lov_qos.lq_active_oss_count - 1;
 201         if (num_active < 1) {
 202                 /* If there's only 1 OSS, we can't penalize it, so instead
 203                    we have to double the OST penalty */
 204                 num_active = 1;
 205                 for (i = 0; i < lov->desc.ld_tgt_count; i++)
 206                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj <<= 1;
 207         }
 208
 209         /* Per-OSS penalty is prio * oss_avail / oss_osts / (num_oss - 1) / 2 */
 210         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 211                 temp = oss->lqo_bavail >> 1;
 212                 do_div(temp, oss->lqo_ost_count * num_active);
 213                 oss->lqo_penalty_per_obj = (temp * prio_wide) >> 8;
 214                 if (lov->lov_qos.lq_reset == 0)
 215                         oss->lqo_penalty = 0;
 216         }
 217
 218         lov->lov_qos.lq_dirty = 0;
 219         lov->lov_qos.lq_reset = 0;
 220
 221         /* If each ost has almost same free space,
 222          * do rr allocation for better creation performance */
 223         lov->lov_qos.lq_same_space = 0;
 224         temp = ba_max - ba_min;
 225         ba_min = (ba_min * 51) >> 8;     /* 51/256 = .20 */
 226         if (temp < ba_min) {
 227                 /* Difference is less than 20% */
 228                 lov->lov_qos.lq_same_space = 1;
 229                 /* Reset weights for the next time we enter qos mode */
 230                 lov->lov_qos.lq_reset = 0;
 231         }
 232         rc = 0;
 233
 234 out:
 235         if (!rc && lov->lov_qos.lq_same_space)
 236                 RETURN(-EAGAIN);
 237         RETURN(rc);
 238 }
 239
 240 static int qos_calc_weight(struct lov_obd *lov, int i)
 241 {
 242         __u64 temp, temp2;
 243
 244         /* Final ost weight = TGT_BAVAIL - ost_penalty - oss_penalty */
 245         temp = TGT_BAVAIL(i);
 246         temp2 = lov->lov_tgts[i]->ltd_qos.ltq_penalty +
 247                 lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty;
 248         if (temp < temp2)
 249                 lov->lov_tgts[i]->ltd_qos.ltq_weight = 0;
 250         else
 251                 lov->lov_tgts[i]->ltd_qos.ltq_weight = temp - temp2;
 252         return 0;
 253 }
 254
 255 /* We just used this index for a stripe; adjust everyone's weights */
 256 static int qos_used(struct lov_obd *lov, __u32 index, __u64 *total_wt)
 257 {
 258         struct lov_qos_oss *oss;
 259         int i;
 260         ENTRY;
 261
 262         /* Don't allocate from this stripe anymore, until the next alloc_qos */
 263         lov->lov_tgts[index]->ltd_qos.ltq_usable = 0;
 264
 265         oss = lov->lov_tgts[index]->ltd_qos.ltq_oss;
 266
 267         /* Decay old penalty by half (we're adding max penalty, and don't
 268            want it to run away.) */
 269         lov->lov_tgts[index]->ltd_qos.ltq_penalty >>= 1;
 270         oss->lqo_penalty >>= 1;
 271
 272         /* Set max penalties for this OST and OSS */
 273         lov->lov_tgts[index]->ltd_qos.ltq_penalty +=
 274                 lov->lov_tgts[index]->ltd_qos.ltq_penalty_per_obj *
 275                 lov->desc.ld_active_tgt_count;
 276         oss->lqo_penalty += oss->lqo_penalty_per_obj *
 277                 lov->lov_qos.lq_active_oss_count;
 278
 279         /* Decrease all OSS penalties */
 280         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 281                 if (oss->lqo_penalty < oss->lqo_penalty_per_obj)
 282                         oss->lqo_penalty = 0;
 283                 else
 284                         oss->lqo_penalty -= oss->lqo_penalty_per_obj;
 285         }
 286
 287         *total_wt = 0;
 288         /* Decrease all OST penalties */
 289         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
 290                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
 291                         continue;
 292                 if (lov->lov_tgts[i]->ltd_qos.ltq_penalty <
 293                     lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj)
 294                         lov->lov_tgts[i]->ltd_qos.ltq_penalty = 0;
 295                 else
 296                         lov->lov_tgts[i]->ltd_qos.ltq_penalty -=
 297                         lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj;
 298
 299                 qos_calc_weight(lov, i);
 300
 301                 /* Recalc the total weight of usable osts */
 302                 if (lov->lov_tgts[i]->ltd_qos.ltq_usable)
 303                         *total_wt += lov->lov_tgts[i]->ltd_qos.ltq_weight;
 304
 305 #ifdef QOS_DEBUG
 306                 CDEBUG(D_QOS, "recalc tgt %d avail="LPU64
 307                        " ostppo="LPU64" ostp="LPU64" ossppo="LPU64
 308                        " ossp="LPU64" wt="LPU64"\n",
 309                        i, TGT_BAVAIL(i)>>10,
 310                        lov->lov_tgts[i]->ltd_qos.ltq_penalty_per_obj>>10,
 311                        lov->lov_tgts[i]->ltd_qos.ltq_penalty>>10,
 312                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty_per_obj>>10,
 313                        lov->lov_tgts[i]->ltd_qos.ltq_oss->lqo_penalty>>10,
 314                        lov->lov_tgts[i]->ltd_qos.ltq_weight>>10);
 315 #endif
 316         }
 317
 318         RETURN(0);
 319 }
 320
 321 #define LOV_QOS_EMPTY ((__u32)-1)
 322 /* compute optimal round-robin order, based on OSTs per OSS */
 323 static int qos_calc_rr(struct lov_obd *lov)
 324 {
 325         struct lov_qos_oss *oss;
 326         unsigned ost_count, placed;
 327         int i;
 328         ENTRY;
 329
 330         if (!lov->lov_qos.lq_dirty_rr) {
 331                 LASSERT(lov->lov_qos.lq_rr_size);
 332                 RETURN(0);
 333         }
 334
 335         down_write(&lov->lov_qos.lq_rw_sem);
 336         ost_count = lov->desc.ld_tgt_count;
 337
 338         if (lov->lov_qos.lq_rr_size)
 339                 OBD_FREE(lov->lov_qos.lq_rr_array, lov->lov_qos.lq_rr_size);
 340         lov->lov_qos.lq_rr_size = ost_count *
 341                 sizeof(lov->lov_qos.lq_rr_array[0]);
 342         OBD_ALLOC(lov->lov_qos.lq_rr_array, lov->lov_qos.lq_rr_size);
 343         if (!lov->lov_qos.lq_rr_array) {
 344                 lov->lov_qos.lq_rr_size = 0;
 345                 up_write(&lov->lov_qos.lq_rw_sem);
 346                 RETURN(-ENOMEM);
 347         }
 348
 349         for (i = 0; i < ost_count; i++)
 350                 lov->lov_qos.lq_rr_array[i] = LOV_QOS_EMPTY;
 351
 352         /* Place all the OSTs from 1 OSS at the same time. */
 353         placed = 0;
 354         list_for_each_entry(oss, &lov->lov_qos.lq_oss_list, lqo_oss_list) {
 355                 int j = 0;
 356                 for (i = 0; i < ost_count; i++) {
 357                       if (lov->lov_tgts[i]->ltd_qos.ltq_oss == oss) {
 358                               /* Evenly space these OSTs across arrayspace */
 359                               int next = j * ost_count / oss->lqo_ost_count;
 360                               while (lov->lov_qos.lq_rr_array[next] !=
 361                                      LOV_QOS_EMPTY)
 362                                       next = (next + 1) % ost_count;
 363                               lov->lov_qos.lq_rr_array[next] = i;
 364                               j++;
 365                               placed++;
 366                       }
 367                 }
 368                 LASSERT(j == oss->lqo_ost_count);
 369         }
 370
 371         lov->lov_qos.lq_dirty_rr = 0;
 372         up_write(&lov->lov_qos.lq_rw_sem);
 373
 374         if (placed != ost_count) {
 375                 /* This should never happen */
 376                 LCONSOLE_ERROR("Failed to place all OSTs in the round-robin "
 377                                "list (%d of %d).\n", placed, ost_count);
 378                 for (i = 0; i < ost_count; i++) {
 379                         LCONSOLE(D_WARNING, "rr #%d ost idx=%d\n", i,
 380                                  lov->lov_qos.lq_rr_array[i]);
 381                 }
 382                 lov->lov_qos.lq_dirty_rr = 1;
 383                 RETURN(-EAGAIN);
 384         }
 385
 386 #ifdef QOS_DEBUG
 387         for (i = 0; i < ost_count; i++) {
 388                 LCONSOLE(D_QOS, "rr #%d ost idx=%d\n", i,
 389                          lov->lov_qos.lq_rr_array[i]);
 390         }
 391 #endif
 392
 393         RETURN(0);
 394 }
 395
 396
 397 void qos_shrink_lsm(struct lov_request_set *set)
 398 {
 399         struct lov_stripe_md *lsm = set->set_oi->oi_md, *lsm_new;
 400         /* XXX LOV STACKING call into osc for sizes */
 401         unsigned oldsize, newsize;
 402
 403         if (set->set_oti && set->set_cookies && set->set_cookie_sent) {
 404                 struct llog_cookie *cookies;
 405                 oldsize = lsm->lsm_stripe_count * sizeof(*cookies);
 406                 newsize = set->set_count * sizeof(*cookies);
 407
 408                 cookies = set->set_cookies;
 409                 oti_alloc_cookies(set->set_oti, set->set_count);
 410                 if (set->set_oti->oti_logcookies) {
 411                         memcpy(set->set_oti->oti_logcookies, cookies, newsize);
 412                         OBD_FREE(cookies, oldsize);
 413                         set->set_cookies = set->set_oti->oti_logcookies;
 414                 } else {
 415                         CWARN("'leaking' %d bytes\n", oldsize - newsize);
 416                 }
 417         }
 418
 419         CWARN("using fewer stripes for object "LPX64": old %u new %u\n",
 420               lsm->lsm_object_id, lsm->lsm_stripe_count, set->set_count);
 421
 422         oldsize = lov_stripe_md_size(lsm->lsm_stripe_count);
 423         newsize = lov_stripe_md_size(set->set_count);
 424         OBD_ALLOC(lsm_new, newsize);
 425         if (lsm_new != NULL) {
 426                 memcpy(lsm_new, lsm, newsize);
 427                 lsm_new->lsm_stripe_count = set->set_count;
 428                 OBD_FREE(lsm, oldsize);
 429                 set->set_oi->oi_md = lsm_new;
 430         } else {
 431                 CWARN("'leaking' %d bytes\n", oldsize - newsize);
 432         }
 433 }
 434
 435 int qos_remedy_create(struct lov_request_set *set, struct lov_request *req)
 436 {
 437         struct lov_stripe_md *lsm = set->set_oi->oi_md;
 438         struct lov_obd *lov = &set->set_exp->exp_obd->u.lov;
 439         unsigned ost_idx, ost_count = lov->desc.ld_tgt_count;
 440         int stripe, i, rc = -EIO;
 441         ENTRY;
 442
 443         ost_idx = (req->rq_idx + lsm->lsm_stripe_count) % ost_count;
 444         for (i = 0; i < ost_count; i++, ost_idx = (ost_idx + 1) % ost_count) {
 445                 if (!lov->lov_tgts[ost_idx] ||
 446                     !lov->lov_tgts[ost_idx]->ltd_active)
 447                         continue;
 448                 /* check if objects has been created on this ost */
 449                 for (stripe = 0; stripe < lsm->lsm_stripe_count; stripe++) {
 450                         if (stripe == req->rq_stripe)
 451                                 continue;
 452                         if (ost_idx == lsm->lsm_oinfo[stripe].loi_ost_idx)
 453                                 break;
 454                 }
 455
 456                 if (stripe >= lsm->lsm_stripe_count) {
 457                         req->rq_idx = ost_idx;
 458                         rc = obd_create(lov->lov_tgts[ost_idx]->ltd_exp,
 459                                         req->rq_oi.oi_oa, &req->rq_oi.oi_md,
 460                                         set->set_oti);
 461                         if (!rc)
 462                                 break;
 463                 }
 464         }
 465         RETURN(rc);
 466 }
 467
 468 #define LOV_CREATE_RESEED_MULT 4
 469 #define LOV_CREATE_RESEED_MIN  1000
 470 /* Allocate objects on osts with round-robin algorithm */
 471 static int alloc_rr(struct lov_obd *lov, int *idx_arr, int *stripe_cnt)
 472 {
 473         unsigned array_idx, ost_count = lov->desc.ld_tgt_count;
 474         unsigned ost_active_count = lov->desc.ld_active_tgt_count;
 475         int i, *idx_pos = idx_arr;
 476         __u32 ost_idx;
 477         ENTRY;
 478
 479         i = qos_calc_rr(lov);
 480         if (i)
 481                 RETURN(i);
 482
 483         if (--lov->lov_start_count <= 0) {
 484                 lov->lov_start_idx = ll_rand() % ost_count;
 485                 lov->lov_start_count =
 486                         (LOV_CREATE_RESEED_MIN / max(ost_active_count, 1U) +
 487                          LOV_CREATE_RESEED_MULT) * max(ost_active_count, 1U);
 488         } else if (*stripe_cnt >= ost_active_count ||
 489                    lov->lov_start_idx > ost_count) {
 490                 /* If we have allocated from all of the OSTs, slowly
 491                    precess the next start */
 492                 lov->lov_start_idx %= ost_count;
 493                 ++lov->lov_offset_idx;
 494         }
 495         array_idx = (lov->lov_start_idx + lov->lov_offset_idx) % ost_count;
 496 #ifdef QOS_DEBUG
 497         CDEBUG(D_QOS, "want %d startidx %d startcnt %d offset %d arrayidx %d\n",
 498                *stripe_cnt, lov->lov_start_idx, lov->lov_start_count,
 499                lov->lov_offset_idx, array_idx);
 500 #endif
 501
 502         down_read(&lov->lov_qos.lq_rw_sem);
 503         for (i = 0; i < ost_count; i++, array_idx=(array_idx + 1) % ost_count) {
 504                 ++lov->lov_start_idx;
 505                 ost_idx = lov->lov_qos.lq_rr_array[array_idx];
 506 #ifdef QOS_DEBUG
 507                 CDEBUG(D_QOS, "#%d strt %d act %d strp %d ary %d idx %d\n",
 508                        i, lov->lov_start_idx,
 509                        lov->lov_tgts[ost_idx] ?
 510                        lov->lov_tgts[ost_idx]->ltd_active : 0,
 511                        idx_pos - idx_arr, array_idx, ost_idx);
 512 #endif
 513                 if (!lov->lov_tgts[ost_idx] ||
 514                     !lov->lov_tgts[ost_idx]->ltd_active)
 515                         continue;
 516                 *idx_pos = ost_idx;
 517                 idx_pos++;
 518                 /* We have enough stripes */
 519                 if (idx_pos - idx_arr == *stripe_cnt)
 520                         break;
 521         }
 522         up_read(&lov->lov_qos.lq_rw_sem);
 523
 524         *stripe_cnt = idx_pos - idx_arr;
 525         RETURN(0);
 526 }
 527
 528 /* alloc objects on osts with specific stripe offset */
 529 static int alloc_specific(struct lov_obd *lov, struct lov_stripe_md *lsm,
 530                           int *idx_arr)
 531 {
 532         unsigned ost_idx, ost_count = lov->desc.ld_tgt_count;
 533         int i, *idx_pos = idx_arr;
 534         ENTRY;
 535
 536         ost_idx = lsm->lsm_oinfo[0].loi_ost_idx;
 537         for (i = 0; i < ost_count; i++, ost_idx = (ost_idx + 1) % ost_count) {
 538                 if (!lov->lov_tgts[ost_idx] ||
 539                     !lov->lov_tgts[ost_idx]->ltd_active) {
 540                         continue;
 541                 }
 542                 *idx_pos = ost_idx;
 543                 idx_pos++;
 544                 /* got enough ost */
 545                 if (idx_pos - idx_arr == lsm->lsm_stripe_count)
 546                         RETURN(0);
 547         }
 548         /* If we were passed specific striping params, then a failure to
 549          * meet those requirements is an error, since we can't reallocate
 550          * that memory (it might be part of a larger array or something).
 551          *
 552          * We can only get here if lsm_stripe_count was originally > 1.
 553          */
 554         CERROR("can't lstripe objid "LPX64": have "LPSZ" want %u\n",
 555                lsm->lsm_object_id, idx_pos - idx_arr, lsm->lsm_stripe_count);
 556         RETURN(-EFBIG);
 557 }
 558
 559 /* Alloc objects on osts with optimization based on:
 560    - free space
 561    - network resources (shared OSS's)
 562 */
 563 static int alloc_qos(struct obd_export *exp, int *idx_arr, int *stripe_cnt)
 564 {
 565         struct lov_obd *lov = &exp->exp_obd->u.lov;
 566         static time_t last_warn = 0;
 567         time_t now = cfs_time_current_sec();
 568         __u64 total_bavail, total_weight = 0;
 569         __u32 ost_count;
 570         int nfound, good_osts, i, warn = 0, rc = 0;
 571         ENTRY;
 572
 573         lov_getref(exp->exp_obd);
 574         down_write(&lov->lov_qos.lq_rw_sem);
 575
 576         ost_count = lov->desc.ld_tgt_count;
 577
 578         if (lov->desc.ld_active_tgt_count < 2)
 579                 GOTO(out, rc = -EAGAIN);
 580
 581         rc = qos_calc_ppo(exp->exp_obd);
 582         if (rc)
 583                 GOTO(out, rc);
 584
 585         total_bavail = 0;
 586         good_osts = 0;
 587         /* Warn users about zero available space/inode every 30 min */
 588         if (cfs_time_sub(now, last_warn) > 60 * 30)
 589                 warn = 1;
 590         /* Find all the OSTs that are valid stripe candidates */
 591         for (i = 0; i < ost_count; i++) {
 592                 __u64 bavail;
 593
 594                 if (!lov->lov_tgts[i] || !lov->lov_tgts[i]->ltd_active)
 595                         continue;
 596                 bavail = TGT_BAVAIL(i);
 597                 if (!bavail) {
 598                         if (warn) {
 599                                 CDEBUG(D_QOS, "no free space on %s\n",
 600                                      obd_uuid2str(&lov->lov_tgts[i]->ltd_uuid));
 601                                 last_warn = now;
 602                         }
 603                         continue;
 604                 }
 605                 if (!TGT_FFREE(i)) {
 606                         if (warn) {
 607                                 CDEBUG(D_QOS, "no free inodes on %s\n",
 608                                      obd_uuid2str(&lov->lov_tgts[i]->ltd_uuid));
 609                                 last_warn = now;
 610                         }
 611                         continue;
 612                 }
 613
 614                 lov->lov_tgts[i]->ltd_qos.ltq_usable = 1;
 615                 qos_calc_weight(lov, i);
 616                 total_bavail += bavail;
 617                 total_weight += lov->lov_tgts[i]->ltd_qos.ltq_weight;
 618
 619                 good_osts++;
 620         }
 621
 622         if (!total_bavail)
 623                 GOTO(out, rc = -ENOSPC);
 624
 625         /* if we don't have enough good OSTs, we reduce the stripe count. */
 626         if (good_osts < *stripe_cnt)
 627                 *stripe_cnt = good_osts;
 628
 629         if (!*stripe_cnt)
 630                 GOTO(out, rc = -EAGAIN);
 631
 632         /* Find enough OSTs with weighted random allocation. */
 633         nfound = 0;
 634         while (nfound < *stripe_cnt) {
 635                 __u64 rand, cur_weight;
 636
 637                 cur_weight = 0;
 638                 rc = -ENODEV;
 639
 640                 if (total_weight) {
 641 #if BITS_PER_LONG == 32
 642                         rand = ll_rand() % (unsigned)total_weight;
 643                         /* If total_weight > 32-bit, first generate the high
 644                          * 32 bits of the random number, then add in the low
 645                          * 32 bits (truncated to the upper limit, if needed) */
 646                         if (total_weight > 0xffffffffULL)
 647                                 rand = (__u64)(ll_rand() %
 648                                           (unsigned)(total_weight >> 32)) << 32;
 649                         else
 650                                 rand = 0;
 651
 652                         if (rand == (total_weight & 0xffffffff00000000ULL))
 653                                 rand |= ll_rand() % (unsigned)total_weight;
 654                         else
 655                                 rand |= ll_rand();
 656
 657 #else
 658                         rand = ((__u64)ll_rand() << 32 | ll_rand()) %
 659                                 total_weight;
 660 #endif
 661                 } else {
 662                         rand = 0;
 663                 }
 664
 665                 /* On average, this will hit larger-weighted osts more often.
 666                    0-weight osts will always get used last (only when rand=0).*/
 667                 for (i = 0; i < ost_count; i++) {
 668                         if (!lov->lov_tgts[i]->ltd_qos.ltq_usable)
 669                                 continue;
 670                         cur_weight += lov->lov_tgts[i]->ltd_qos.ltq_weight;
 671                         if (cur_weight >= rand) {
 672 #ifdef QOS_DEBUG
 673                                 CDEBUG(D_QOS, "assigned stripe=%d to idx=%d\n",
 674                                        nfound, i);
 675 #endif
 676                                 idx_arr[nfound++] = i;
 677                                 qos_used(lov, i, &total_weight);
 678                                 rc = 0;
 679                                 break;
 680                         }
 681                 }
 682                 /* should never satisfy below condition */
 683                 if (rc) {
 684                         CERROR("Didn't find any OSTs?\n");
 685                         break;
 686                 }
 687         }
 688         LASSERT(nfound == *stripe_cnt);
 689
 690 out:
 691         up_write(&lov->lov_qos.lq_rw_sem);
 692
 693         if (rc == -EAGAIN)
 694                 rc = alloc_rr(lov, idx_arr, stripe_cnt);
 695
 696         lov_putref(exp->exp_obd);
 697         RETURN(rc);
 698 }
 699
 700 /* return new alloced stripe count on success */
 701 static int alloc_idx_array(struct obd_export *exp, struct lov_stripe_md *lsm,
 702                            int newea, int **idx_arr, int *arr_cnt)
 703 {
 704         struct lov_obd *lov = &exp->exp_obd->u.lov;
 705         int stripe_cnt = lsm->lsm_stripe_count;
 706         int i, rc = 0;
 707         int *tmp_arr = NULL;
 708         ENTRY;
 709
 710         *arr_cnt = stripe_cnt;
 711         OBD_ALLOC(tmp_arr, *arr_cnt * sizeof(int));
 712         if (tmp_arr == NULL)
 713                 RETURN(-ENOMEM);
 714         for (i = 0; i < *arr_cnt; i++)
 715                 tmp_arr[i] = -1;
 716
 717         if (newea ||
 718             lsm->lsm_oinfo[0].loi_ost_idx >= lov->desc.ld_tgt_count)
 719                 rc = alloc_qos(exp, tmp_arr, &stripe_cnt);
 720         else
 721                 rc = alloc_specific(lov, lsm, tmp_arr);
 722
 723         if (rc)
 724                 GOTO(out_arr, rc);
 725
 726         *idx_arr = tmp_arr;
 727         RETURN(stripe_cnt);
 728 out_arr:
 729         OBD_FREE(tmp_arr, *arr_cnt * sizeof(int));
 730         *arr_cnt = 0;
 731         RETURN(rc);
 732 }
 733
 734 static void free_idx_array(int *idx_arr, int arr_cnt)
 735 {
 736         if (arr_cnt)
 737                 OBD_FREE(idx_arr, arr_cnt * sizeof(int));
 738 }
 739
 740 int qos_prep_create(struct obd_export *exp, struct lov_request_set *set)
 741 {
 742         struct lov_obd *lov = &exp->exp_obd->u.lov;
 743         struct lov_stripe_md *lsm;
 744         struct obdo *src_oa = set->set_oi->oi_oa;
 745         struct obd_trans_info *oti = set->set_oti;
 746         int i, stripes, rc = 0, newea = 0;
 747         int *idx_arr, idx_cnt = 0;
 748         ENTRY;
 749
 750         LASSERT(src_oa->o_valid & OBD_MD_FLID);
 751
 752         if (set->set_oi->oi_md == NULL) {
 753                 int stripe_cnt = lov_get_stripecnt(lov, 0);
 754
 755                 /* If the MDS file was truncated up to some size, stripe over
 756                  * enough OSTs to allow the file to be created at that size.
 757                  * This may mean we use more than the default # of stripes. */
 758                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
 759                         obd_size min_bavail = LUSTRE_STRIPE_MAXBYTES;
 760
 761                         /* Find a small number of stripes we can use
 762                            (up to # of active osts). */
 763                         stripes = 1;
 764                         lov_getref(exp->exp_obd);
 765                         for (i = 0; i < lov->desc.ld_tgt_count; i++) {
 766                                 if (!lov->lov_tgts[i] ||
 767                                     !lov->lov_tgts[i]->ltd_active)
 768                                         continue;
 769                                 min_bavail = min(min_bavail, TGT_BAVAIL(i));
 770                                 if (min_bavail * stripes > src_oa->o_size)
 771                                         break;
 772                                 stripes++;
 773                         }
 774                         lov_putref(exp->exp_obd);
 775
 776                         if (stripes < stripe_cnt)
 777                                 stripes = stripe_cnt;
 778                 } else {
 779                         stripes = stripe_cnt;
 780                 }
 781
 782                 rc = lov_alloc_memmd(&set->set_oi->oi_md, stripes,
 783                                      lov->desc.ld_pattern ?
 784                                      lov->desc.ld_pattern : LOV_PATTERN_RAID0,
 785                                      LOV_MAGIC);
 786                 if (rc < 0)
 787                         GOTO(out_err, rc);
 788                 rc = 0;
 789                 newea = 1;
 790         }
 791
 792         lsm = set->set_oi->oi_md;
 793         lsm->lsm_object_id = src_oa->o_id;
 794         if (!lsm->lsm_stripe_size)
 795                 lsm->lsm_stripe_size = lov->desc.ld_default_stripe_size;
 796         if (!lsm->lsm_pattern) {
 797                 LASSERT(lov->desc.ld_pattern);
 798                 lsm->lsm_pattern = lov->desc.ld_pattern;
 799         }
 800
 801         stripes = alloc_idx_array(exp, lsm, newea, &idx_arr, &idx_cnt);
 802         LASSERT(stripes <= lsm->lsm_stripe_count);
 803         if (stripes <= 0)
 804                 GOTO(out_err, rc = stripes ? stripes : -EIO);
 805
 806         for (i = 0; i < stripes; i++) {
 807                 struct lov_request *req;
 808                 int ost_idx = idx_arr[i];
 809                 LASSERT(ost_idx >= 0);
 810
 811                 OBD_ALLOC(req, sizeof(*req));
 812                 if (req == NULL)
 813                         GOTO(out_err, rc = -ENOMEM);
 814                 lov_set_add_req(req, set);
 815
 816                 req->rq_buflen = sizeof(*req->rq_oi.oi_md);
 817                 OBD_ALLOC(req->rq_oi.oi_md, req->rq_buflen);
 818                 if (req->rq_oi.oi_md == NULL)
 819                         GOTO(out_err, rc = -ENOMEM);
 820
 821                 req->rq_oi.oi_oa = obdo_alloc();
 822                 if (req->rq_oi.oi_oa == NULL)
 823                         GOTO(out_err, rc = -ENOMEM);
 824
 825                 req->rq_idx = ost_idx;
 826                 req->rq_stripe = i;
 827                 /* create data objects with "parent" OA */
 828                 memcpy(req->rq_oi.oi_oa, src_oa, sizeof(*req->rq_oi.oi_oa));
 829
 830                 /* XXX When we start creating objects on demand, we need to
 831                  *     make sure that we always create the object on the
 832                  *     stripe which holds the existing file size.
 833                  */
 834                 if (src_oa->o_valid & OBD_MD_FLSIZE) {
 835                         req->rq_oi.oi_oa->o_size =
 836                                 lov_size_to_stripe(lsm, src_oa->o_size, i);
 837
 838                         CDEBUG(D_INODE, "stripe %d has size "LPU64"/"LPU64"\n",
 839                                i, req->rq_oi.oi_oa->o_size, src_oa->o_size);
 840                 }
 841
 842         }
 843         LASSERT(set->set_count == stripes);
 844
 845         if (stripes < lsm->lsm_stripe_count)
 846                 qos_shrink_lsm(set);
 847
 848         if (oti && (src_oa->o_valid & OBD_MD_FLCOOKIE)) {
 849                 oti_alloc_cookies(oti, set->set_count);
 850                 if (!oti->oti_logcookies)
 851                         GOTO(out_err, rc = -ENOMEM);
 852                 set->set_cookies = oti->oti_logcookies;
 853         }
 854 out_err:
 855         if (newea && rc)
 856                 obd_free_memmd(exp, &set->set_oi->oi_md);
 857         free_idx_array(idx_arr, idx_cnt);
 858         EXIT;
 859         return rc;
 860 }
 861
 862 void qos_update(struct lov_obd *lov)
 863 {
 864         ENTRY;
 865         lov->lov_qos.lq_dirty = 1;
 866 }
 867