lustre/quota/qsd_lib.c

   1 /*
   2  * GPL HEADER START
   3  *
   4  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   5  *
   6  * This program is free software; you can redistribute it and/or modify
   7  * it under the terms of the GNU General Public License version 2 only,
   8  * as published by the Free Software Foundation.
   9  *
  10  * This program is distributed in the hope that it will be useful, but
  11  * WITHOUT ANY WARRANTY; without even the implied warranty of
  12  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13  * General Public License version 2 for more details (a copy is included
  14  * in the LICENSE file that accompanied this code).
  15  *
  16  * You should have received a copy of the GNU General Public License
  17  * version 2 along with this program; if not, write to the
  18  * Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  19  * Boston, MA 021110-1307, USA
  20  *
  21  * GPL HEADER END
  22  */
  23 /*
  24  * Copyright (c) 2012 Intel, Inc.
  25  * Use is subject to license terms.
  26  *
  27  * Author: Johann Lombardi <johann.lombardi@intel.com>
  28  * Author: Niu    Yawei    <yawei.niu@intel.com>
  29  */
  30
  31 /*
  32  * Quota Slave Driver (QSD) management.
  33  *
  34  * The quota slave feature is implemented under the form of a library called
  35  * QSD. Each OSD device should create a QSD instance via qsd_init() which will
  36  * be used to manage quota enforcement for this device. This implies:
  37  * - completing the reintegration procedure with the quota master (aka QMT, see
  38  *   qmt_dev.c) to retrieve the latest quota settings and space distribution.
  39  * - managing quota locks in order to be notified of configuration changes.
  40  * - acquiring space from the QMT when quota space for a given user/group is
  41  *   close to exhaustion.
  42  * - allocating quota space to service threads for local request processing.
  43  *
  44  * Once the QSD instance created, the OSD device should invoke qsd_start()
  45  * when recovery is completed. This notifies the QSD that we are about to
  46  * process new requests on which quota should be strictly enforced.
  47  * Then, qsd_op_begin/end can be used to reserve/release/pre-acquire quota space
  48  * for/after each operation until shutdown where the QSD instance should be
  49  * freed via qsd_fini().
  50  */
  51
  52 #ifndef EXPORT_SYMTAB
  53 # define EXPORT_SYMTAB
  54 #endif
  55
  56 #define DEBUG_SUBSYSTEM S_LQUOTA
  57
  58 #include <obd_class.h>
  59 #include "qsd_internal.h"
  60
  61 cfs_mem_cache_t *upd_kmem;
  62
  63 struct lu_kmem_descr qsd_caches[] = {
  64         {
  65                 .ckd_cache = &upd_kmem,
  66                 .ckd_name  = "upd_kmem",
  67                 .ckd_size  = sizeof(struct qsd_upd_rec)
  68         },
  69         {
  70                 .ckd_cache = NULL
  71         }
  72 };
  73
  74 /* define qsd thread key */
  75 LU_KEY_INIT_FINI(qsd, struct qsd_thread_info);
  76 LU_CONTEXT_KEY_DEFINE(qsd, LCT_MD_THREAD | LCT_DT_THREAD | LCT_LOCAL);
  77 LU_KEY_INIT_GENERIC(qsd);
  78
  79 /* some procfs helpers */
  80 static int lprocfs_qsd_rd_state(char *page, char **start, off_t off,
  81                                 int count, int *eof, void *data)
  82 {
  83         struct qsd_instance     *qsd = (struct qsd_instance *)data;
  84         char                     enabled[5];
  85         int                      rc;
  86
  87         LASSERT(qsd != NULL);
  88
  89         memset(enabled, 0, sizeof(enabled));
  90         if (qsd_type_enabled(qsd, USRQUOTA))
  91                 strcat(enabled, "u");
  92         if (qsd_type_enabled(qsd, GRPQUOTA))
  93                 strcat(enabled, "g");
  94         if (strlen(enabled) == 0)
  95                 strcat(enabled, "none");
  96
  97         rc = snprintf(page, count,
  98                       "target name:    %s\n"
  99                       "pool ID:        %d\n"
 100                       "type:           %s\n"
 101                       "quota enabled:  %s\n"
 102                       "conn to master: %s\n",
 103                       qsd->qsd_svname, qsd->qsd_pool_id,
 104                       qsd->qsd_is_md ? "md" : "dt", enabled,
 105                       qsd->qsd_exp_valid ? "setup" : "not setup yet");
 106
 107         if (qsd->qsd_prepared)
 108                 rc +=  snprintf(page + rc, count - rc,
 109                                 "user uptodate:  glb[%d],slv[%d],reint[%d]\n"
 110                                 "group uptodate: glb[%d],slv[%d],reint[%d]\n",
 111                                 qsd->qsd_type_array[USRQUOTA]->qqi_glb_uptodate,
 112                                 qsd->qsd_type_array[USRQUOTA]->qqi_slv_uptodate,
 113                                 qsd->qsd_type_array[USRQUOTA]->qqi_reint,
 114                                 qsd->qsd_type_array[GRPQUOTA]->qqi_glb_uptodate,
 115                                 qsd->qsd_type_array[GRPQUOTA]->qqi_slv_uptodate,
 116                                 qsd->qsd_type_array[GRPQUOTA]->qqi_reint);
 117         return rc;
 118 }
 119
 120 static int lprocfs_qsd_rd_enabled(char *page, char **start, off_t off,
 121                                   int count, int *eof, void *data)
 122 {
 123         struct qsd_instance     *qsd = (struct qsd_instance *)data;
 124         char                     enabled[5];
 125         LASSERT(qsd != NULL);
 126
 127         memset(enabled, 0, sizeof(enabled));
 128         if (qsd_type_enabled(qsd, USRQUOTA))
 129                 strcat(enabled, "u");
 130         if (qsd_type_enabled(qsd, GRPQUOTA))
 131                 strcat(enabled, "g");
 132         if (strlen(enabled) == 0)
 133                 strcat(enabled, "none");
 134
 135         return snprintf(page, count, "%s\n", enabled);
 136 }
 137
 138 static struct lprocfs_vars lprocfs_quota_qsd_vars[] = {
 139         { "info", lprocfs_qsd_rd_state, 0, 0},
 140         { "enabled", lprocfs_qsd_rd_enabled, 0, 0},
 141         { NULL }
 142 };
 143
 144 /*
 145  * Callback function invoked by the OSP layer when the connection to the master
 146  * has been set up.
 147  *
 148  * \param data - is a pointer to the qsd_instance
 149  *
 150  * \retval - 0 on success, appropriate error on failure
 151  */
 152 static int qsd_conn_callback(void *data)
 153 {
 154         struct qsd_instance *qsd = (struct qsd_instance *)data;
 155         int                  type;
 156         ENTRY;
 157
 158         /* qsd_exp should now be valid */
 159         LASSERT(qsd->qsd_exp);
 160
 161         /* grab reference on namespace */
 162         ldlm_namespace_get(class_exp2obd(qsd->qsd_exp)->obd_namespace);
 163         qsd->qsd_ns = class_exp2obd(qsd->qsd_exp)->obd_namespace;
 164
 165         cfs_write_lock(&qsd->qsd_lock);
 166         /* notify that qsd_exp is now valid */
 167         qsd->qsd_exp_valid = true;
 168         cfs_write_unlock(&qsd->qsd_lock);
 169
 170         /* Now that the connection to master is setup, we can initiate the
 171          * reintegration procedure for quota types which are enabled.
 172          * It is worth noting that, if the qsd_instance hasn't been started
 173          * already, then we can only complete the first two steps of the
 174          * reintegration procedure (i.e. global lock enqueue and slave
 175          * index transfer) since the space usage reconciliation (i.e.
 176          * step 3) will have to wait for qsd_start() to be called */
 177         for (type = USRQUOTA; type < MAXQUOTAS; type++) {
 178                 struct qsd_qtype_info *qqi = qsd->qsd_type_array[type];
 179                 cfs_waitq_signal(&qqi->qqi_reint_thread.t_ctl_waitq);
 180         }
 181
 182         RETURN(0);
 183 }
 184
 185 /*
 186  * Release qsd_qtype_info structure which contains data associated with a
 187  * given quota type. This releases the accounting objects.
 188  * It's called on OSD cleanup when the qsd instance is released.
 189  *
 190  * \param env - is the environment passed by the caller
 191  * \param qsd - is the qsd instance managing the qsd_qtype_info structure
 192  *              to be released
 193  * \param qtype - is the quota type to be shutdown
 194  */
 195 static void qsd_qtype_fini(const struct lu_env *env, struct qsd_instance *qsd,
 196                            int qtype)
 197 {
 198         struct qsd_qtype_info   *qqi;
 199         ENTRY;
 200
 201         if (qsd->qsd_type_array[qtype] == NULL)
 202                 RETURN_EXIT;
 203         qqi = qsd->qsd_type_array[qtype];
 204         qsd->qsd_type_array[qtype] = NULL;
 205
 206         /* all deferred work lists should be empty */
 207         LASSERT(cfs_list_empty(&qqi->qqi_deferred_glb));
 208         LASSERT(cfs_list_empty(&qqi->qqi_deferred_slv));
 209
 210         /* shutdown lquota site */
 211         if (qqi->qqi_site != NULL && !IS_ERR(qqi->qqi_site)) {
 212                 lquota_site_free(env, qqi->qqi_site);
 213                 qqi->qqi_site = NULL;
 214         }
 215
 216         /* by now, all qqi users should have gone away */
 217         LASSERT(cfs_atomic_read(&qqi->qqi_ref) == 1);
 218         lu_ref_fini(&qqi->qqi_reference);
 219
 220         /* release accounting object */
 221         if (qqi->qqi_acct_obj != NULL && !IS_ERR(qqi->qqi_acct_obj)) {
 222                 lu_object_put(env, &qqi->qqi_acct_obj->do_lu);
 223                 qqi->qqi_acct_obj = NULL;
 224         }
 225
 226         /* release slv index */
 227         if (qqi->qqi_slv_obj != NULL && !IS_ERR(qqi->qqi_slv_obj)) {
 228                 lu_object_put(env, &qqi->qqi_slv_obj->do_lu);
 229                 qqi->qqi_slv_obj = NULL;
 230                 qqi->qqi_slv_ver = 0;
 231         }
 232
 233         /* release global index */
 234         if (qqi->qqi_glb_obj != NULL && !IS_ERR(qqi->qqi_glb_obj)) {
 235                 lu_object_put(env, &qqi->qqi_glb_obj->do_lu);
 236                 qqi->qqi_glb_obj = NULL;
 237                 qqi->qqi_glb_ver = 0;
 238         }
 239
 240         OBD_FREE_PTR(qqi);
 241         EXIT;
 242 }
 243
 244 /*
 245  * Allocate and initialize a qsd_qtype_info structure for quota type \qtype.
 246  * This opens the accounting object and initializes the proc file.
 247  * It's called on OSD start when the qsd_prepare() is invoked on the qsd
 248  * instance.
 249  *
 250  * \param env  - the environment passed by the caller
 251  * \param qsd  - is the qsd instance which will be in charge of the new
 252  *               qsd_qtype_info instance.
 253  * \param qtype - is quota type to set up
 254  *
 255  * \retval - 0 on success and qsd->qsd_type_array[qtype] is allocated,
 256  *           appropriate error on failure
 257  */
 258 static int qsd_qtype_init(const struct lu_env *env, struct qsd_instance *qsd,
 259                           int qtype)
 260 {
 261         struct qsd_qtype_info   *qqi;
 262         int                      rc;
 263         struct obd_uuid          uuid;
 264         ENTRY;
 265
 266         LASSERT(qsd->qsd_type_array[qtype] == NULL);
 267
 268         /* allocate structure for this quota type */
 269         OBD_ALLOC_PTR(qqi);
 270         if (qqi == NULL)
 271                 RETURN(-ENOMEM);
 272         qsd->qsd_type_array[qtype] = qqi;
 273         cfs_atomic_set(&qqi->qqi_ref, 1); /* referenced from qsd */
 274
 275         /* set backpointer and other parameters */
 276         qqi->qqi_qsd   = qsd;
 277         qqi->qqi_qtype = qtype;
 278         lu_ref_init(&qqi->qqi_reference);
 279         lquota_generate_fid(&qqi->qqi_fid, qsd->qsd_pool_id, QSD_RES_TYPE(qsd),
 280                             qtype);
 281         qqi->qqi_glb_uptodate = false;
 282         qqi->qqi_slv_uptodate = false;
 283         qqi->qqi_reint        = false;
 284         cfs_waitq_init(&qqi->qqi_reint_thread.t_ctl_waitq);
 285         thread_set_flags(&qqi->qqi_reint_thread, SVC_STOPPED);
 286         CFS_INIT_LIST_HEAD(&qqi->qqi_deferred_glb);
 287         CFS_INIT_LIST_HEAD(&qqi->qqi_deferred_slv);
 288         memset(&qqi->qqi_lockh, 0, sizeof(qqi->qqi_lockh));
 289
 290         /* open accounting object */
 291         LASSERT(qqi->qqi_acct_obj == NULL);
 292         qqi->qqi_acct_obj = acct_obj_lookup(env, qsd->qsd_dev, qtype);
 293         if (qqi->qqi_acct_obj == NULL) {
 294                 LCONSOLE_ERROR("%s: No %s space accounting support. Please use "
 295                                "tunefs.lustre --quota option to enable quota "
 296                                "accounting.\n",
 297                                qsd->qsd_svname, QTYPE_NAME(qtype));
 298                 GOTO(out, rc = -ENOENT);
 299         }
 300
 301         /* open global index copy */
 302         LASSERT(qqi->qqi_glb_obj == NULL);
 303         qqi->qqi_glb_obj = lquota_disk_glb_find_create(env, qsd->qsd_dev,
 304                                                        qsd->qsd_root,
 305                                                        &qqi->qqi_fid, true);
 306         if (IS_ERR(qqi->qqi_glb_obj)) {
 307                 CERROR("%s: can't open global index copy "DFID" %ld\n",
 308                        qsd->qsd_svname, PFID(&qqi->qqi_fid),
 309                        PTR_ERR(qqi->qqi_glb_obj));
 310                 GOTO(out, rc = PTR_ERR(qqi->qqi_glb_obj));
 311         }
 312         qqi->qqi_glb_ver = dt_version_get(env, qqi->qqi_glb_obj);
 313
 314         /* open slave index copy */
 315         LASSERT(qqi->qqi_slv_obj == NULL);
 316         obd_str2uuid(&uuid, qsd->qsd_svname);
 317         qqi->qqi_slv_obj = lquota_disk_slv_find_create(env, qsd->qsd_dev,
 318                                                        qsd->qsd_root,
 319                                                        &qqi->qqi_fid, &uuid,
 320                                                        true);
 321         if (IS_ERR(qqi->qqi_slv_obj)) {
 322                 CERROR("%s: can't open slave index copy "DFID" %ld\n",
 323                        qsd->qsd_svname, PFID(&qqi->qqi_fid),
 324                        PTR_ERR(qqi->qqi_slv_obj));
 325                 GOTO(out, rc = PTR_ERR(qqi->qqi_slv_obj));
 326         }
 327         qqi->qqi_slv_ver = dt_version_get(env, qqi->qqi_slv_obj);
 328
 329         /* allocate site */
 330         qqi->qqi_site = lquota_site_alloc(env, qqi, false, qtype, &qsd_lqe_ops);
 331         if (IS_ERR(qqi->qqi_site)) {
 332                 CERROR("%s: can't allocate site "DFID" %ld\n", qsd->qsd_svname,
 333                        PFID(&qqi->qqi_fid), PTR_ERR(qqi->qqi_site));
 334                 GOTO(out, rc = PTR_ERR(qqi->qqi_site));
 335         }
 336
 337         /* register proc entry for accounting object */
 338         rc = lprocfs_seq_create(qsd->qsd_proc,
 339                                 qtype == USRQUOTA ? "acct_user" : "acct_group",
 340                                 0444, &lprocfs_quota_seq_fops,
 341                                 qqi->qqi_acct_obj);
 342         if (rc) {
 343                 CERROR("%s: can't add procfs entry for accounting file %d\n",
 344                        qsd->qsd_svname, rc);
 345                 GOTO(out, rc);
 346         }
 347         EXIT;
 348 out:
 349         if (rc)
 350                 qsd_qtype_fini(env, qsd, qtype);
 351         return rc;
 352 }
 353
 354 /*
 355  * Release a qsd_instance. Companion of qsd_init(). This releases all data
 356  * structures associated with the quota slave (on-disk objects, lquota entry
 357  * tables, ...).
 358  * This function should be called when the OSD is shutting down.
 359  *
 360  * \param env - is the environment passed by the caller
 361  * \param qsd - is the qsd instance to shutdown
 362  */
 363 void qsd_fini(const struct lu_env *env, struct qsd_instance *qsd)
 364 {
 365         int     qtype;
 366         ENTRY;
 367
 368         CDEBUG(D_QUOTA, "%s: initiating QSD shutdown\n", qsd->qsd_svname);
 369         cfs_write_lock(&qsd->qsd_lock);
 370         qsd->qsd_stopping = true;
 371         cfs_write_unlock(&qsd->qsd_lock);
 372
 373         /* remove from the list of fsinfo */
 374         if (!cfs_list_empty(&qsd->qsd_link)) {
 375                 LASSERT(qsd->qsd_fsinfo != NULL);
 376                 cfs_down(&qsd->qsd_fsinfo->qfs_sem);
 377                 cfs_list_del_init(&qsd->qsd_link);
 378                 cfs_up(&qsd->qsd_fsinfo->qfs_sem);
 379         }
 380
 381         /* remove qsd proc entry */
 382         if (qsd->qsd_proc != NULL) {
 383                 lprocfs_remove(&qsd->qsd_proc);
 384                 qsd->qsd_proc = NULL;
 385         }
 386
 387         /* stop the writeback thread */
 388         qsd_stop_upd_thread(qsd);
 389
 390         /* shutdown the reintegration threads */
 391         for (qtype = USRQUOTA; qtype < MAXQUOTAS; qtype++) {
 392                 if (qsd->qsd_type_array[qtype] == NULL)
 393                         continue;
 394                 qsd_stop_reint_thread(qsd->qsd_type_array[qtype]);
 395         }
 396
 397         /* release reference on namespace */
 398         if (qsd->qsd_ns != NULL) {
 399                 ldlm_namespace_put(qsd->qsd_ns);
 400                 qsd->qsd_ns = NULL;
 401         }
 402
 403         /* free per-quota type data */
 404         for (qtype = USRQUOTA; qtype < MAXQUOTAS; qtype++)
 405                 qsd_qtype_fini(env, qsd, qtype);
 406
 407         /* deregister connection to the quota master */
 408         qsd->qsd_exp_valid = false;
 409         lustre_deregister_osp_item(&qsd->qsd_exp);
 410
 411         /* release per-filesystem information */
 412         if (qsd->qsd_fsinfo != NULL)
 413                 qsd_put_fsinfo(qsd->qsd_fsinfo);
 414
 415         /* release quota root directory */
 416         if (qsd->qsd_root != NULL) {
 417                 lu_object_put(env, &qsd->qsd_root->do_lu);
 418                 qsd->qsd_root = NULL;
 419         }
 420
 421         /* release reference on dt_device */
 422         if (qsd->qsd_dev != NULL) {
 423                 lu_ref_del(&qsd->qsd_dev->dd_lu_dev.ld_reference, "qsd", qsd);
 424                 lu_device_put(&qsd->qsd_dev->dd_lu_dev);
 425                 qsd->qsd_dev = NULL;
 426         }
 427
 428         CDEBUG(D_QUOTA, "%s: QSD shutdown completed\n", qsd->qsd_svname);
 429         OBD_FREE_PTR(qsd);
 430         EXIT;
 431 }
 432 EXPORT_SYMBOL(qsd_fini);
 433
 434 /*
 435  * Create a new qsd_instance to be associated with backend osd device
 436  * identified by \dev.
 437  *
 438  * \param env    - the environment passed by the caller
 439  * \param svname - is the service name of the OSD device creating this instance
 440  * \param dev    - is the dt_device where to store quota index files
 441  * \param osd_proc - is the procfs parent directory where to create procfs file
 442  *                   related to this new qsd instance
 443  *
 444  * \retval - pointer to new qsd_instance associated with dev \dev on success,
 445  *           appropriate error on failure
 446  */
 447 struct qsd_instance *qsd_init(const struct lu_env *env, char *svname,
 448                               struct dt_device *dev,
 449                               cfs_proc_dir_entry_t *osd_proc)
 450 {
 451         struct qsd_thread_info  *qti = qsd_info(env);
 452         struct qsd_instance     *qsd;
 453         int                      rc, type, idx;
 454         ENTRY;
 455
 456         /* only configure qsd for MDT & OST */
 457         type = server_name2index(svname, &idx, NULL);
 458         if (type != LDD_F_SV_TYPE_MDT && type != LDD_F_SV_TYPE_OST)
 459                 RETURN(NULL);
 460
 461         /* allocate qsd instance */
 462         OBD_ALLOC_PTR(qsd);
 463         if (qsd == NULL)
 464                 RETURN(ERR_PTR(-ENOMEM));
 465
 466         /* generic initializations */
 467         cfs_rwlock_init(&qsd->qsd_lock);
 468         CFS_INIT_LIST_HEAD(&qsd->qsd_link);
 469         thread_set_flags(&qsd->qsd_upd_thread, SVC_STOPPED);
 470         cfs_waitq_init(&qsd->qsd_upd_thread.t_ctl_waitq);
 471         CFS_INIT_LIST_HEAD(&qsd->qsd_upd_list);
 472         cfs_spin_lock_init(&qsd->qsd_adjust_lock);
 473         CFS_INIT_LIST_HEAD(&qsd->qsd_adjust_list);
 474         qsd->qsd_prepared = false;
 475         qsd->qsd_started = false;
 476
 477         /* copy service name */
 478         strncpy(qsd->qsd_svname, svname, MAX_OBD_NAME);
 479
 480         /* grab reference on osd device */
 481         lu_device_get(&dev->dd_lu_dev);
 482         lu_ref_add(&dev->dd_lu_dev.ld_reference, "qsd", qsd);
 483         qsd->qsd_dev = dev;
 484
 485         /* we only support pool ID 0 (default data or metadata pool) for the
 486          * time being. A different pool ID could be assigned to this target via
 487          * the configuration log in the future */
 488         qsd->qsd_pool_id  = 0;
 489
 490         /* get fsname from svname */
 491         rc = server_name2fsname(svname, qti->qti_buf, NULL);
 492         if (rc) {
 493                 CERROR("%s: fail to extract filesystem name\n", svname);
 494                 GOTO(out, rc);
 495         }
 496
 497         /* look up quota setting for the filesystem the target belongs to */
 498         qsd->qsd_fsinfo = qsd_get_fsinfo(qti->qti_buf, 1);
 499         if (qsd->qsd_fsinfo == NULL) {
 500                 CERROR("%s: failed to locate filesystem information\n", svname);
 501                 GOTO(out, rc = -EINVAL);
 502         }
 503
 504         /* add in the list of lquota_fsinfo */
 505         cfs_down(&qsd->qsd_fsinfo->qfs_sem);
 506         list_add_tail(&qsd->qsd_link, &qsd->qsd_fsinfo->qfs_qsd_list);
 507         cfs_up(&qsd->qsd_fsinfo->qfs_sem);
 508
 509         /* register procfs directory */
 510         qsd->qsd_proc = lprocfs_register(QSD_DIR, osd_proc,
 511                                          lprocfs_quota_qsd_vars, qsd);
 512         if (IS_ERR(qsd->qsd_proc)) {
 513                 rc = PTR_ERR(qsd->qsd_proc);
 514                 qsd->qsd_proc = NULL;
 515                 CERROR("%s: fail to create quota slave proc entry (%d)\n",
 516                        svname, rc);
 517                 GOTO(out, rc);
 518         }
 519         EXIT;
 520 out:
 521         if (rc) {
 522                 qsd_fini(env, qsd);
 523                 return ERR_PTR(rc);
 524         }
 525         RETURN(qsd);
 526 }
 527 EXPORT_SYMBOL(qsd_init);
 528
 529 /*
 530  * Initialize on-disk structures in order to manage quota enforcement for
 531  * the target associated with the qsd instance \qsd and starts the reintegration
 532  * procedure for each quota type as soon as possible.
 533  * The last step of the reintegration will be completed once qsd_start() is
 534  * called, at which points the space reconciliation with the master will be
 535  * executed.
 536  * This function must be called when the server stack is fully configured,
 537  * typically when ->ldo_prepare is called across the stack.
 538  *
 539  * \param env - the environment passed by the caller
 540  * \param qsd - is qsd_instance to prepare
 541  *
 542  * \retval - 0 on success, appropriate error on failure
 543  */
 544 int qsd_prepare(const struct lu_env *env, struct qsd_instance *qsd)
 545 {
 546         struct qsd_thread_info  *qti = qsd_info(env);
 547         int                      qtype, rc = 0;
 548         ENTRY;
 549
 550         LASSERT(qsd != NULL);
 551
 552         cfs_read_lock(&qsd->qsd_lock);
 553         if (qsd->qsd_prepared) {
 554                 CERROR("%s: qsd instance already prepared\n", qsd->qsd_svname);
 555                 rc = -EALREADY;
 556         }
 557         cfs_read_unlock(&qsd->qsd_lock);
 558         if (rc)
 559                 RETURN(rc);
 560
 561         /* Record whether this qsd instance is managing quota enforcement for a
 562          * MDT (i.e. inode quota) or OST (block quota) */
 563         if (lu_device_is_md(qsd->qsd_dev->dd_lu_dev.ld_site->ls_top_dev)) {
 564                 qsd->qsd_is_md = true;
 565                 qsd->qsd_sync_threshold = LQUOTA_LEAST_QUNIT(LQUOTA_RES_MD);
 566         } else {
 567                 qsd->qsd_sync_threshold = LQUOTA_LEAST_QUNIT(LQUOTA_RES_DT);
 568         }
 569
 570         /* look-up on-disk directory for the quota slave */
 571         qsd->qsd_root = lquota_disk_dir_find_create(env, qsd->qsd_dev, NULL,
 572                                                     QSD_DIR);
 573         if (IS_ERR(qsd->qsd_root)) {
 574                 rc = PTR_ERR(qsd->qsd_root);
 575                 qsd->qsd_root = NULL;
 576                 CERROR("%s: failed to create quota slave root dir (%d)\n",
 577                        qsd->qsd_svname, rc);
 578                 RETURN(rc);
 579         }
 580
 581         /* initialize per-quota type data */
 582         for (qtype = USRQUOTA; qtype < MAXQUOTAS; qtype++) {
 583                 rc = qsd_qtype_init(env, qsd, qtype);
 584                 if (rc)
 585                         RETURN(rc);
 586         }
 587
 588         /* pools successfully setup, mark the qsd as prepared */
 589         cfs_write_lock(&qsd->qsd_lock);
 590         qsd->qsd_prepared = true;
 591         cfs_write_unlock(&qsd->qsd_lock);
 592
 593         /* start reintegration thread for each type, if required */
 594         for (qtype = USRQUOTA; qtype < MAXQUOTAS; qtype++) {
 595                 struct qsd_qtype_info   *qqi = qsd->qsd_type_array[qtype];
 596
 597                 rc = qsd_start_reint_thread(qqi);
 598                 if (rc) {
 599                         CERROR("%s: failed to start reint thread for type %s "
 600                                "(%d)\n", qsd->qsd_svname, QTYPE_NAME(qtype),
 601                                rc);
 602                         RETURN(rc);
 603                 }
 604         }
 605
 606         /* start writeback thread */
 607         rc = qsd_start_upd_thread(qsd);
 608         if (rc) {
 609                 CERROR("%s: failed to start writeback thread (%d)\n",
 610                        qsd->qsd_svname, rc);
 611                 RETURN(rc);
 612         }
 613
 614         /* generate osp name */
 615         rc = tgt_name2ospname((char *)qsd->qsd_svname, qti->qti_buf);
 616         if (rc) {
 617                 CERROR("%s: failed to generate ospname (%d)\n",
 618                        qsd->qsd_svname, rc);
 619                 RETURN(rc);
 620         }
 621
 622         /* the connection callback will start the reintegration
 623          * procedure if quota is enabled */
 624         rc = lustre_register_osp_item(qti->qti_buf, &qsd->qsd_exp,
 625                                       qsd_conn_callback, (void *)qsd);
 626         if (rc) {
 627                 CERROR("%s: fail to get connection to master (%d)\n",
 628                        qsd->qsd_svname, rc);
 629                 RETURN(rc);
 630         }
 631
 632         RETURN(0);
 633 }
 634 EXPORT_SYMBOL(qsd_prepare);
 635
 636 /*
 637  * Start a qsd instance. This will complete the last step of the reintegration
 638  * procedure as soon as possible (provided that the master is reachable).
 639  * This should be called when recovery has been completed and quota should now
 640  * be enforced on every operations.
 641  *
 642  * \param env - the environment passed by the caller
 643  * \param qsd - is the qsd instance associated with the osd device to start
 644  */
 645 int qsd_start(const struct lu_env *env, struct qsd_instance *qsd)
 646 {
 647         int     type, rc = 0;
 648         ENTRY;
 649
 650         cfs_write_lock(&qsd->qsd_lock);
 651         if (!qsd->qsd_prepared) {
 652                 CERROR("%s: can't start qsd instance since it was properly "
 653                        "initialized\n", qsd->qsd_svname);
 654                 rc = -EFAULT;
 655         } else if (qsd->qsd_started) {
 656                 CERROR("%s: qsd instance already started\n", qsd->qsd_svname);
 657                 rc = -EALREADY;
 658         } else {
 659                 /* notify that the qsd_instance is now started */
 660                 qsd->qsd_started = true;
 661         }
 662         cfs_write_unlock(&qsd->qsd_lock);
 663
 664         if (rc)
 665                 RETURN(rc);
 666
 667         /* Trigger the 3rd step of reintegration: If usage > granted, acquire
 668          * up to usage; If usage < granted, release down to usage.  */
 669         for (type = USRQUOTA; type < MAXQUOTAS; type++) {
 670                 struct qsd_qtype_info   *qqi = qsd->qsd_type_array[type];
 671                 cfs_waitq_signal(&qqi->qqi_reint_thread.t_ctl_waitq);
 672         }
 673
 674         RETURN(rc);
 675 }
 676 EXPORT_SYMBOL(qsd_start);
 677
 678 void lustre_register_quota_process_config(int (*qpc)(struct lustre_cfg *lcfg));
 679
 680 /*
 681  * Global initialization performed at module load time
 682  */
 683 int qsd_glb_init(void)
 684 {
 685         int     rc;
 686
 687         rc = lu_kmem_init(qsd_caches);
 688         if (rc)
 689                 return rc;
 690
 691         qsd_key_init_generic(&qsd_thread_key, NULL);
 692         lu_context_key_register(&qsd_thread_key);
 693         lustre_register_quota_process_config(qsd_process_config);
 694
 695         return 0;
 696 }
 697
 698 /*
 699  * Companion of qsd_glb_init() called at module unload time
 700  */
 701 void qsd_glb_fini(void)
 702 {
 703         lustre_register_quota_process_config(NULL);
 704         lu_kmem_fini(qsd_caches);
 705         lu_context_key_degister(&qsd_thread_key);
 706 }