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LU-137 obdclass: add dt_object_put() and use it
[fs/lustre-release.git] / 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, 2016, Intel Corporation.
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 #define DEBUG_SUBSYSTEM S_LQUOTA
53
54 #include <obd_class.h>
55 #include "qsd_internal.h"
56
57 struct kmem_cache *upd_kmem;
58
59 struct lu_kmem_descr qsd_caches[] = {
60         {
61                 .ckd_cache = &upd_kmem,
62                 .ckd_name  = "upd_kmem",
63                 .ckd_size  = sizeof(struct qsd_upd_rec)
64         },
65         {
66                 .ckd_cache = NULL
67         }
68 };
69
70 /* define qsd thread key */
71 LU_KEY_INIT_FINI(qsd, struct qsd_thread_info);
72 LU_CONTEXT_KEY_DEFINE(qsd, LCT_MD_THREAD | LCT_DT_THREAD | LCT_LOCAL);
73 LU_KEY_INIT_GENERIC(qsd);
74
75 /* some procfs helpers */
76 static int qsd_state_seq_show(struct seq_file *m, void *data)
77 {
78         struct qsd_instance     *qsd = m->private;
79         char                     enabled[5];
80
81         LASSERT(qsd != NULL);
82
83         memset(enabled, 0, sizeof(enabled));
84         if (qsd_type_enabled(qsd, USRQUOTA))
85                 strcat(enabled, "u");
86         if (qsd_type_enabled(qsd, GRPQUOTA))
87                 strcat(enabled, "g");
88         if (strlen(enabled) == 0)
89                 strcat(enabled, "none");
90
91         seq_printf(m, "target name:    %s\n"
92                    "pool ID:        %d\n"
93                    "type:           %s\n"
94                    "quota enabled:  %s\n"
95                    "conn to master: %s\n",
96                    qsd->qsd_svname, qsd->qsd_pool_id,
97                    qsd->qsd_is_md ? "md" : "dt", enabled,
98                    qsd->qsd_exp_valid ? "setup" : "not setup yet");
99
100         if (qsd->qsd_prepared) {
101                 memset(enabled, 0, sizeof(enabled));
102                 if (qsd->qsd_type_array[USRQUOTA]->qqi_acct_obj != NULL)
103                         strcat(enabled, "u");
104                 if (qsd->qsd_type_array[GRPQUOTA]->qqi_acct_obj != NULL)
105                         strcat(enabled, "g");
106                 if (strlen(enabled) == 0)
107                         strcat(enabled, "none");
108                 seq_printf(m, "space acct:     %s\n"
109                            "user uptodate:  glb[%d],slv[%d],reint[%d]\n"
110                            "group uptodate: glb[%d],slv[%d],reint[%d]\n",
111                            enabled,
112                            qsd->qsd_type_array[USRQUOTA]->qqi_glb_uptodate,
113                            qsd->qsd_type_array[USRQUOTA]->qqi_slv_uptodate,
114                            qsd->qsd_type_array[USRQUOTA]->qqi_reint,
115                            qsd->qsd_type_array[GRPQUOTA]->qqi_glb_uptodate,
116                            qsd->qsd_type_array[GRPQUOTA]->qqi_slv_uptodate,
117                            qsd->qsd_type_array[GRPQUOTA]->qqi_reint);
118         }
119         return 0;
120 }
121 LPROC_SEQ_FOPS_RO(qsd_state);
122
123 static int qsd_enabled_seq_show(struct seq_file *m, void *data)
124 {
125         struct qsd_instance     *qsd = m->private;
126         char                     enabled[5];
127
128         LASSERT(qsd != NULL);
129
130         memset(enabled, 0, sizeof(enabled));
131         if (qsd_type_enabled(qsd, USRQUOTA))
132                 strcat(enabled, "u");
133         if (qsd_type_enabled(qsd, GRPQUOTA))
134                 strcat(enabled, "g");
135         if (strlen(enabled) == 0)
136                 strcat(enabled, "none");
137
138         seq_printf(m, "%s\n", enabled);
139         return 0;
140 }
141 LPROC_SEQ_FOPS_RO(qsd_enabled);
142
143 /* force reintegration procedure to be executed.
144  * Used for test/debugging purpose */
145 static ssize_t
146 lprocfs_force_reint_seq_write(struct file *file, const char __user *buffer,
147                                 size_t count, loff_t *off)
148 {
149         struct qsd_instance *qsd = ((struct seq_file *)file->private_data)->private;
150         int                  rc = 0, qtype;
151
152         LASSERT(qsd != NULL);
153
154         write_lock(&qsd->qsd_lock);
155         if (qsd->qsd_stopping) {
156                 /* don't mess up with shutdown procedure, it is already
157                  * complicated enough */
158                 rc = -ESHUTDOWN;
159         } else if (!qsd->qsd_prepared) {
160                 rc = -EAGAIN;
161         } else {
162                 /* mark all indexes as stale */
163                 for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++) {
164                         qsd->qsd_type_array[qtype]->qqi_glb_uptodate = false;
165                         qsd->qsd_type_array[qtype]->qqi_slv_uptodate = false;
166                 }
167         }
168         write_unlock(&qsd->qsd_lock);
169
170         if (rc)
171                 return rc;
172
173         /* kick off reintegration */
174         for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++) {
175                 rc = qsd_start_reint_thread(qsd->qsd_type_array[qtype]);
176                 if (rc)
177                         break;
178         }
179         return rc == 0 ? count : rc;
180 }
181 LPROC_SEQ_FOPS_WO_TYPE(qsd, force_reint);
182
183 static int qsd_timeout_seq_show(struct seq_file *m, void *data)
184 {
185         struct qsd_instance *qsd = m->private;
186         LASSERT(qsd != NULL);
187
188         seq_printf(m, "%d\n", qsd_wait_timeout(qsd));
189         return 0;
190 }
191
192 static ssize_t
193 qsd_timeout_seq_write(struct file *file, const char __user *buffer,
194                         size_t count, loff_t *off)
195 {
196         struct qsd_instance *qsd = ((struct seq_file *)file->private_data)->private;
197         int rc;
198         __s64 timeout;
199         LASSERT(qsd != NULL);
200
201         rc = lprocfs_str_to_s64(buffer, count, &timeout);
202         if (rc)
203                 return rc;
204         if (timeout < 0 || timeout > INT_MAX)
205                 return -EINVAL;
206
207         qsd->qsd_timeout = timeout;
208         return count;
209 }
210 LPROC_SEQ_FOPS(qsd_timeout);
211
212 static struct lprocfs_vars lprocfs_quota_qsd_vars[] = {
213         { .name =       "info",
214           .fops =       &qsd_state_fops         },
215         { .name =       "enabled",
216           .fops =       &qsd_enabled_fops       },
217         { .name =       "force_reint",
218           .fops =       &qsd_force_reint_fops   },
219         { .name =       "timeout",
220           .fops =       &qsd_timeout_fops       },
221         { NULL }
222 };
223
224 /*
225  * Callback function invoked by the OSP layer when the connection to the master
226  * has been set up.
227  *
228  * \param data - is a pointer to the qsd_instance
229  *
230  * \retval - 0 on success, appropriate error on failure
231  */
232 static int qsd_conn_callback(void *data)
233 {
234         struct qsd_instance *qsd = (struct qsd_instance *)data;
235         int                  type;
236         ENTRY;
237
238         /* qsd_exp should now be valid */
239         LASSERT(qsd->qsd_exp);
240
241         qsd->qsd_ns = class_exp2obd(qsd->qsd_exp)->obd_namespace;
242
243         write_lock(&qsd->qsd_lock);
244         /* notify that qsd_exp is now valid */
245         qsd->qsd_exp_valid = true;
246         write_unlock(&qsd->qsd_lock);
247
248         /* Now that the connection to master is setup, we can initiate the
249          * reintegration procedure for quota types which are enabled.
250          * It is worth noting that, if the qsd_instance hasn't been started
251          * already, then we can only complete the first two steps of the
252          * reintegration procedure (i.e. global lock enqueue and slave
253          * index transfer) since the space usage reconciliation (i.e.
254          * step 3) will have to wait for qsd_start() to be called */
255         for (type = USRQUOTA; type < LL_MAXQUOTAS; type++) {
256                 struct qsd_qtype_info *qqi = qsd->qsd_type_array[type];
257                 wake_up(&qqi->qqi_reint_thread.t_ctl_waitq);
258         }
259
260         RETURN(0);
261 }
262
263 /*
264  * Release qsd_qtype_info structure which contains data associated with a
265  * given quota type. This releases the accounting objects.
266  * It's called on OSD cleanup when the qsd instance is released.
267  *
268  * \param env - is the environment passed by the caller
269  * \param qsd - is the qsd instance managing the qsd_qtype_info structure
270  *              to be released
271  * \param qtype - is the quota type to be shutdown
272  */
273 static void qsd_qtype_fini(const struct lu_env *env, struct qsd_instance *qsd,
274                            int qtype)
275 {
276         struct qsd_qtype_info   *qqi;
277         int repeat = 0;
278         ENTRY;
279
280         if (qsd->qsd_type_array[qtype] == NULL)
281                 RETURN_EXIT;
282         qqi = qsd->qsd_type_array[qtype];
283         qsd->qsd_type_array[qtype] = NULL;
284
285         /* all deferred work lists should be empty */
286         LASSERT(list_empty(&qqi->qqi_deferred_glb));
287         LASSERT(list_empty(&qqi->qqi_deferred_slv));
288
289         /* shutdown lquota site */
290         if (qqi->qqi_site != NULL && !IS_ERR(qqi->qqi_site)) {
291                 lquota_site_free(env, qqi->qqi_site);
292                 qqi->qqi_site = NULL;
293         }
294
295         /* The qqi may still be holding by global locks which are being
296          * canceled asynchronously (LU-4365), see the following steps:
297          *
298          * - On server umount, we try to clear all quota locks first by
299          *   disconnecting LWP (which will invalidate import and cleanup
300          *   all locks on it), however, if quota reint process is holding
301          *   the global lock for reintegration at that time, global lock
302          *   will fail to be cleared on LWP disconnection.
303          *
304          * - Umount process goes on and stops reint process, the global
305          *   lock will be dropped on reint process exit, however, the lock
306          *   cancel in done in asynchronous way, so the
307          *   qsd_glb_blocking_ast() might haven't been called yet when we
308          *   get here.
309          */
310         while (atomic_read(&qqi->qqi_ref) > 1) {
311                 CDEBUG(D_QUOTA, "qqi reference count %u, repeat: %d\n",
312                        atomic_read(&qqi->qqi_ref), repeat);
313                 repeat++;
314                 set_current_state(TASK_INTERRUPTIBLE);
315                 schedule_timeout(cfs_time_seconds(1));
316         }
317
318         /* by now, all qqi users should have gone away */
319         LASSERT(atomic_read(&qqi->qqi_ref) == 1);
320         lu_ref_fini(&qqi->qqi_reference);
321
322         /* release accounting object */
323         if (qqi->qqi_acct_obj != NULL && !IS_ERR(qqi->qqi_acct_obj)) {
324                 dt_object_put(env, qqi->qqi_acct_obj);
325                 qqi->qqi_acct_obj = NULL;
326         }
327
328         /* release slv index */
329         if (qqi->qqi_slv_obj != NULL && !IS_ERR(qqi->qqi_slv_obj)) {
330                 dt_object_put(env, qqi->qqi_slv_obj);
331                 qqi->qqi_slv_obj = NULL;
332                 qqi->qqi_slv_ver = 0;
333         }
334
335         /* release global index */
336         if (qqi->qqi_glb_obj != NULL && !IS_ERR(qqi->qqi_glb_obj)) {
337                 dt_object_put(env, qqi->qqi_glb_obj);
338                 qqi->qqi_glb_obj = NULL;
339                 qqi->qqi_glb_ver = 0;
340         }
341
342         OBD_FREE_PTR(qqi);
343         EXIT;
344 }
345
346 /*
347  * Allocate and initialize a qsd_qtype_info structure for quota type \qtype.
348  * This opens the accounting object and initializes the proc file.
349  * It's called on OSD start when the qsd_prepare() is invoked on the qsd
350  * instance.
351  *
352  * \param env  - the environment passed by the caller
353  * \param qsd  - is the qsd instance which will be in charge of the new
354  *               qsd_qtype_info instance.
355  * \param qtype - is quota type to set up
356  *
357  * \retval - 0 on success and qsd->qsd_type_array[qtype] is allocated,
358  *           appropriate error on failure
359  */
360 static int qsd_qtype_init(const struct lu_env *env, struct qsd_instance *qsd,
361                           int qtype)
362 {
363         struct qsd_qtype_info   *qqi;
364         int                      rc;
365         struct obd_uuid          uuid;
366         ENTRY;
367
368         LASSERT(qsd->qsd_type_array[qtype] == NULL);
369
370         /* allocate structure for this quota type */
371         OBD_ALLOC_PTR(qqi);
372         if (qqi == NULL)
373                 RETURN(-ENOMEM);
374         qsd->qsd_type_array[qtype] = qqi;
375         atomic_set(&qqi->qqi_ref, 1); /* referenced from qsd */
376
377         /* set backpointer and other parameters */
378         qqi->qqi_qsd   = qsd;
379         qqi->qqi_qtype = qtype;
380         lu_ref_init(&qqi->qqi_reference);
381         lquota_generate_fid(&qqi->qqi_fid, qsd->qsd_pool_id, QSD_RES_TYPE(qsd),
382                             qtype);
383         qqi->qqi_glb_uptodate = false;
384         qqi->qqi_slv_uptodate = false;
385         qqi->qqi_reint        = false;
386         init_waitqueue_head(&qqi->qqi_reint_thread.t_ctl_waitq);
387         thread_set_flags(&qqi->qqi_reint_thread, SVC_STOPPED);
388         INIT_LIST_HEAD(&qqi->qqi_deferred_glb);
389         INIT_LIST_HEAD(&qqi->qqi_deferred_slv);
390
391         /* open accounting object */
392         LASSERT(qqi->qqi_acct_obj == NULL);
393         qqi->qqi_acct_obj = acct_obj_lookup(env, qsd->qsd_dev, qtype);
394         if (IS_ERR(qqi->qqi_acct_obj)) {
395                 CDEBUG(D_QUOTA, "%s: no %s space accounting support rc:%ld\n",
396                        qsd->qsd_svname, QTYPE_NAME(qtype),
397                        PTR_ERR(qqi->qqi_acct_obj));
398                 qqi->qqi_acct_obj = NULL;
399                 qsd->qsd_acct_failed = true;
400         }
401
402         /* open global index copy */
403         LASSERT(qqi->qqi_glb_obj == NULL);
404         qqi->qqi_glb_obj = lquota_disk_glb_find_create(env, qsd->qsd_dev,
405                                                        qsd->qsd_root,
406                                                        &qqi->qqi_fid, true);
407         if (IS_ERR(qqi->qqi_glb_obj)) {
408                 CERROR("%s: can't open global index copy "DFID" %ld\n",
409                        qsd->qsd_svname, PFID(&qqi->qqi_fid),
410                        PTR_ERR(qqi->qqi_glb_obj));
411                 GOTO(out, rc = PTR_ERR(qqi->qqi_glb_obj));
412         }
413         qqi->qqi_glb_ver = dt_version_get(env, qqi->qqi_glb_obj);
414
415         /* open slave index copy */
416         LASSERT(qqi->qqi_slv_obj == NULL);
417         obd_str2uuid(&uuid, qsd->qsd_svname);
418         qqi->qqi_slv_obj = lquota_disk_slv_find_create(env, qsd->qsd_dev,
419                                                        qsd->qsd_root,
420                                                        &qqi->qqi_fid, &uuid,
421                                                        true);
422         if (IS_ERR(qqi->qqi_slv_obj)) {
423                 CERROR("%s: can't open slave index copy "DFID" %ld\n",
424                        qsd->qsd_svname, PFID(&qqi->qqi_fid),
425                        PTR_ERR(qqi->qqi_slv_obj));
426                 GOTO(out, rc = PTR_ERR(qqi->qqi_slv_obj));
427         }
428         qqi->qqi_slv_ver = dt_version_get(env, qqi->qqi_slv_obj);
429
430         /* allocate site */
431         qqi->qqi_site = lquota_site_alloc(env, qqi, false, qtype, &qsd_lqe_ops);
432         if (IS_ERR(qqi->qqi_site)) {
433                 CERROR("%s: can't allocate site "DFID" %ld\n", qsd->qsd_svname,
434                        PFID(&qqi->qqi_fid), PTR_ERR(qqi->qqi_site));
435                 GOTO(out, rc = PTR_ERR(qqi->qqi_site));
436         }
437
438         /* register proc entry for accounting & global index copy objects */
439         rc = lprocfs_seq_create(qsd->qsd_proc,
440                                 qtype == USRQUOTA ? "acct_user" : "acct_group",
441                                 0444, &lprocfs_quota_seq_fops,
442                                 qqi->qqi_acct_obj);
443         if (rc) {
444                 CERROR("%s: can't add procfs entry for accounting file %d\n",
445                        qsd->qsd_svname, rc);
446                 GOTO(out, rc);
447         }
448
449         rc = lprocfs_seq_create(qsd->qsd_proc,
450                                 qtype == USRQUOTA ? "limit_user" : "limit_group",
451                                 0444, &lprocfs_quota_seq_fops,
452                                 qqi->qqi_glb_obj);
453         if (rc) {
454                 CERROR("%s: can't add procfs entry for global index copy %d\n",
455                        qsd->qsd_svname, rc);
456                 GOTO(out, rc);
457         }
458         EXIT;
459 out:
460         if (rc)
461                 qsd_qtype_fini(env, qsd, qtype);
462         return rc;
463 }
464
465 /*
466  * Release a qsd_instance. Companion of qsd_init(). This releases all data
467  * structures associated with the quota slave (on-disk objects, lquota entry
468  * tables, ...).
469  * This function should be called when the OSD is shutting down.
470  *
471  * \param env - is the environment passed by the caller
472  * \param qsd - is the qsd instance to shutdown
473  */
474 void qsd_fini(const struct lu_env *env, struct qsd_instance *qsd)
475 {
476         int     qtype;
477         ENTRY;
478
479         if (unlikely(qsd == NULL))
480                 RETURN_EXIT;
481
482         CDEBUG(D_QUOTA, "%s: initiating QSD shutdown\n", qsd->qsd_svname);
483         write_lock(&qsd->qsd_lock);
484         qsd->qsd_stopping = true;
485         write_unlock(&qsd->qsd_lock);
486
487         /* remove qsd proc entry */
488         if (qsd->qsd_proc != NULL) {
489                 lprocfs_remove(&qsd->qsd_proc);
490                 qsd->qsd_proc = NULL;
491         }
492
493         /* stop the writeback thread */
494         qsd_stop_upd_thread(qsd);
495
496         /* shutdown the reintegration threads */
497         for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++) {
498                 if (qsd->qsd_type_array[qtype] == NULL)
499                         continue;
500                 qsd_stop_reint_thread(qsd->qsd_type_array[qtype]);
501         }
502
503         if (qsd->qsd_ns != NULL) {
504                 qsd->qsd_ns = NULL;
505         }
506
507         /* free per-quota type data */
508         for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++)
509                 qsd_qtype_fini(env, qsd, qtype);
510
511         if (qsd->qsd_exp) {
512                 /* deregister connection to the quota master */
513                 qsd->qsd_exp_valid = false;
514                 lustre_deregister_lwp_item(&qsd->qsd_exp);
515         }
516
517         /* release per-filesystem information */
518         if (qsd->qsd_fsinfo != NULL) {
519                 mutex_lock(&qsd->qsd_fsinfo->qfs_mutex);
520                 /* remove from the list of fsinfo */
521                 list_del_init(&qsd->qsd_link);
522                 mutex_unlock(&qsd->qsd_fsinfo->qfs_mutex);
523                 qsd_put_fsinfo(qsd->qsd_fsinfo);
524                 qsd->qsd_fsinfo = NULL;
525         }
526
527         /* release quota root directory */
528         if (qsd->qsd_root != NULL) {
529                 dt_object_put(env, qsd->qsd_root);
530                 qsd->qsd_root = NULL;
531         }
532
533         /* release reference on dt_device */
534         if (qsd->qsd_dev != NULL) {
535                 lu_ref_del(&qsd->qsd_dev->dd_lu_dev.ld_reference, "qsd", qsd);
536                 lu_device_put(&qsd->qsd_dev->dd_lu_dev);
537                 qsd->qsd_dev = NULL;
538         }
539
540         CDEBUG(D_QUOTA, "%s: QSD shutdown completed\n", qsd->qsd_svname);
541         OBD_FREE_PTR(qsd);
542         EXIT;
543 }
544 EXPORT_SYMBOL(qsd_fini);
545
546 /*
547  * Create a new qsd_instance to be associated with backend osd device
548  * identified by \dev.
549  *
550  * \param env    - the environment passed by the caller
551  * \param svname - is the service name of the OSD device creating this instance
552  * \param dev    - is the dt_device where to store quota index files
553  * \param osd_proc - is the procfs parent directory where to create procfs file
554  *                   related to this new qsd instance
555  *
556  * \retval - pointer to new qsd_instance associated with dev \dev on success,
557  *           appropriate error on failure
558  */
559 struct qsd_instance *qsd_init(const struct lu_env *env, char *svname,
560                               struct dt_device *dev,
561                               struct proc_dir_entry *osd_proc)
562 {
563         struct qsd_thread_info  *qti = qsd_info(env);
564         struct qsd_instance     *qsd;
565         int                      rc, type, idx;
566         ENTRY;
567
568         /* only configure qsd for MDT & OST */
569         type = server_name2index(svname, &idx, NULL);
570         if (type != LDD_F_SV_TYPE_MDT && type != LDD_F_SV_TYPE_OST)
571                 RETURN(NULL);
572
573         /* allocate qsd instance */
574         OBD_ALLOC_PTR(qsd);
575         if (qsd == NULL)
576                 RETURN(ERR_PTR(-ENOMEM));
577
578         /* generic initializations */
579         rwlock_init(&qsd->qsd_lock);
580         INIT_LIST_HEAD(&qsd->qsd_link);
581         thread_set_flags(&qsd->qsd_upd_thread, SVC_STOPPED);
582         init_waitqueue_head(&qsd->qsd_upd_thread.t_ctl_waitq);
583         INIT_LIST_HEAD(&qsd->qsd_upd_list);
584         spin_lock_init(&qsd->qsd_adjust_lock);
585         INIT_LIST_HEAD(&qsd->qsd_adjust_list);
586         qsd->qsd_prepared = false;
587         qsd->qsd_started = false;
588
589         /* copy service name */
590         if (strlcpy(qsd->qsd_svname, svname, sizeof(qsd->qsd_svname))
591             >= sizeof(qsd->qsd_svname))
592                 GOTO(out, rc = -E2BIG);
593
594         /* grab reference on osd device */
595         lu_device_get(&dev->dd_lu_dev);
596         lu_ref_add(&dev->dd_lu_dev.ld_reference, "qsd", qsd);
597         qsd->qsd_dev = dev;
598
599         /* we only support pool ID 0 (default data or metadata pool) for the
600          * time being. A different pool ID could be assigned to this target via
601          * the configuration log in the future */
602         qsd->qsd_pool_id  = 0;
603
604         /* get fsname from svname */
605         rc = server_name2fsname(svname, qti->qti_buf, NULL);
606         if (rc) {
607                 CERROR("%s: fail to extract filesystem name\n", svname);
608                 GOTO(out, rc);
609         }
610
611         /* look up quota setting for the filesystem the target belongs to */
612         qsd->qsd_fsinfo = qsd_get_fsinfo(qti->qti_buf, 1);
613         if (qsd->qsd_fsinfo == NULL) {
614                 CERROR("%s: failed to locate filesystem information\n", svname);
615                 GOTO(out, rc = -EINVAL);
616         }
617
618         /* add in the list of lquota_fsinfo */
619         mutex_lock(&qsd->qsd_fsinfo->qfs_mutex);
620         list_add_tail(&qsd->qsd_link, &qsd->qsd_fsinfo->qfs_qsd_list);
621         mutex_unlock(&qsd->qsd_fsinfo->qfs_mutex);
622
623         /* register procfs directory */
624         qsd->qsd_proc = lprocfs_register(QSD_DIR, osd_proc,
625                                          lprocfs_quota_qsd_vars, qsd);
626         if (IS_ERR(qsd->qsd_proc)) {
627                 rc = PTR_ERR(qsd->qsd_proc);
628                 qsd->qsd_proc = NULL;
629                 CERROR("%s: fail to create quota slave proc entry (%d)\n",
630                        svname, rc);
631                 GOTO(out, rc);
632         }
633         EXIT;
634 out:
635         if (rc) {
636                 qsd_fini(env, qsd);
637                 return ERR_PTR(rc);
638         }
639         RETURN(qsd);
640 }
641 EXPORT_SYMBOL(qsd_init);
642
643 /*
644  * Initialize on-disk structures in order to manage quota enforcement for
645  * the target associated with the qsd instance \qsd and starts the reintegration
646  * procedure for each quota type as soon as possible.
647  * The last step of the reintegration will be completed once qsd_start() is
648  * called, at which points the space reconciliation with the master will be
649  * executed.
650  * This function must be called when the server stack is fully configured,
651  * typically when ->ldo_prepare is called across the stack.
652  *
653  * \param env - the environment passed by the caller
654  * \param qsd - is qsd_instance to prepare
655  *
656  * \retval - 0 on success, appropriate error on failure
657  */
658 int qsd_prepare(const struct lu_env *env, struct qsd_instance *qsd)
659 {
660         struct qsd_thread_info  *qti = qsd_info(env);
661         int                      qtype, rc = 0;
662         ENTRY;
663
664         if (unlikely(qsd == NULL))
665                 RETURN(0);
666
667         read_lock(&qsd->qsd_lock);
668         if (qsd->qsd_prepared) {
669                 CERROR("%s: qsd instance already prepared\n", qsd->qsd_svname);
670                 rc = -EALREADY;
671         }
672         read_unlock(&qsd->qsd_lock);
673         if (rc)
674                 RETURN(rc);
675
676         /* Record whether this qsd instance is managing quota enforcement for a
677          * MDT (i.e. inode quota) or OST (block quota) */
678         if (lu_device_is_md(qsd->qsd_dev->dd_lu_dev.ld_site->ls_top_dev)) {
679                 qsd->qsd_is_md = true;
680                 qsd->qsd_sync_threshold = LQUOTA_LEAST_QUNIT(LQUOTA_RES_MD);
681         } else {
682                 qsd->qsd_sync_threshold = LQUOTA_LEAST_QUNIT(LQUOTA_RES_DT);
683         }
684
685         /* look-up on-disk directory for the quota slave */
686         qsd->qsd_root = lquota_disk_dir_find_create(env, qsd->qsd_dev, NULL,
687                                                     QSD_DIR);
688         if (IS_ERR(qsd->qsd_root)) {
689                 rc = PTR_ERR(qsd->qsd_root);
690                 qsd->qsd_root = NULL;
691                 CERROR("%s: failed to create quota slave root dir (%d)\n",
692                        qsd->qsd_svname, rc);
693                 RETURN(rc);
694         }
695
696         /* initialize per-quota type data */
697         for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++) {
698                 rc = qsd_qtype_init(env, qsd, qtype);
699                 if (rc)
700                         RETURN(rc);
701         }
702
703         /* pools successfully setup, mark the qsd as prepared */
704         write_lock(&qsd->qsd_lock);
705         qsd->qsd_prepared = true;
706         write_unlock(&qsd->qsd_lock);
707
708         if (qsd->qsd_dev->dd_rdonly)
709                 RETURN(0);
710
711         /* start reintegration thread for each type, if required */
712         for (qtype = USRQUOTA; qtype < LL_MAXQUOTAS; qtype++) {
713                 struct qsd_qtype_info   *qqi = qsd->qsd_type_array[qtype];
714
715                 if (qsd_type_enabled(qsd, qtype) && qsd->qsd_acct_failed) {
716                         LCONSOLE_ERROR("%s: can't enable quota enforcement "
717                                        "since space accounting isn't functional"
718                                        ". Please run tunefs.lustre --quota on "
719                                        "an unmounted filesystem if not done "
720                                        "already\n", qsd->qsd_svname);
721                         break;
722                 }
723
724                 rc = qsd_start_reint_thread(qqi);
725                 if (rc) {
726                         CERROR("%s: failed to start reint thread for type %s "
727                                "(%d)\n", qsd->qsd_svname, QTYPE_NAME(qtype),
728                                rc);
729                         RETURN(rc);
730                 }
731         }
732
733         /* start writeback thread */
734         rc = qsd_start_upd_thread(qsd);
735         if (rc) {
736                 CERROR("%s: failed to start writeback thread (%d)\n",
737                        qsd->qsd_svname, rc);
738                 RETURN(rc);
739         }
740
741         /* generate osp name */
742         rc = tgt_name2lwp_name(qsd->qsd_svname, qti->qti_buf,
743                                MTI_NAME_MAXLEN, 0);
744         if (rc) {
745                 CERROR("%s: failed to generate ospname (%d)\n",
746                        qsd->qsd_svname, rc);
747                 RETURN(rc);
748         }
749
750         /* the connection callback will start the reintegration
751          * procedure if quota is enabled */
752         rc = lustre_register_lwp_item(qti->qti_buf, &qsd->qsd_exp,
753                                       qsd_conn_callback, (void *)qsd);
754         if (rc) {
755                 CERROR("%s: fail to get connection to master (%d)\n",
756                        qsd->qsd_svname, rc);
757                 RETURN(rc);
758         }
759
760         RETURN(0);
761 }
762 EXPORT_SYMBOL(qsd_prepare);
763
764 /*
765  * Start a qsd instance. This will complete the last step of the reintegration
766  * procedure as soon as possible (provided that the master is reachable).
767  * This should be called when recovery has been completed and quota should now
768  * be enforced on every operations.
769  *
770  * \param env - the environment passed by the caller
771  * \param qsd - is the qsd instance associated with the osd device to start
772  */
773 int qsd_start(const struct lu_env *env, struct qsd_instance *qsd)
774 {
775         int     type, rc = 0;
776         ENTRY;
777
778         if (unlikely(qsd == NULL))
779                 RETURN(0);
780
781         write_lock(&qsd->qsd_lock);
782         if (!qsd->qsd_prepared) {
783                 CERROR("%s: can't start qsd instance since it wasn't properly "
784                        "initialized\n", qsd->qsd_svname);
785                 rc = -EFAULT;
786         } else if (qsd->qsd_started) {
787                 CERROR("%s: qsd instance already started\n", qsd->qsd_svname);
788                 rc = -EALREADY;
789         } else {
790                 /* notify that the qsd_instance is now started */
791                 qsd->qsd_started = true;
792         }
793         write_unlock(&qsd->qsd_lock);
794
795         if (rc)
796                 RETURN(rc);
797
798         /* Trigger the 3rd step of reintegration: If usage > granted, acquire
799          * up to usage; If usage < granted, release down to usage.  */
800         for (type = USRQUOTA; type < LL_MAXQUOTAS; type++) {
801                 struct qsd_qtype_info   *qqi = qsd->qsd_type_array[type];
802                 wake_up(&qqi->qqi_reint_thread.t_ctl_waitq);
803         }
804
805         RETURN(rc);
806 }
807 EXPORT_SYMBOL(qsd_start);
808
809 void lustre_register_quota_process_config(int (*qpc)(struct lustre_cfg *lcfg));
810
811 /*
812  * Global initialization performed at module load time
813  */
814 int qsd_glb_init(void)
815 {
816         int     rc;
817
818         rc = lu_kmem_init(qsd_caches);
819         if (rc)
820                 return rc;
821
822         qsd_key_init_generic(&qsd_thread_key, NULL);
823         lu_context_key_register(&qsd_thread_key);
824         lustre_register_quota_process_config(qsd_process_config);
825
826         return 0;
827 }
828
829 /*
830  * Companion of qsd_glb_init() called at module unload time
831  */
832 void qsd_glb_fini(void)
833 {
834         lustre_register_quota_process_config(NULL);
835         lu_kmem_fini(qsd_caches);
836         lu_context_key_degister(&qsd_thread_key);
837 }