kernel/drivers/staging/lustre/lustre/fld/fld_request.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, see
  18  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, 2013, Intel Corporation.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * lustre/fld/fld_request.c
  37  *
  38  * FLD (Fids Location Database)
  39  *
  40  * Author: Yury Umanets <umka@clusterfs.com>
  41  */
  42
  43 #define DEBUG_SUBSYSTEM S_FLD
  44
  45 #include "../../include/linux/libcfs/libcfs.h"
  46 #include <linux/module.h>
  47 #include <asm/div64.h>
  48
  49 #include "../include/obd.h"
  50 #include "../include/obd_class.h"
  51 #include "../include/lustre_ver.h"
  52 #include "../include/obd_support.h"
  53 #include "../include/lprocfs_status.h"
  54
  55 #include "../include/lustre_req_layout.h"
  56 #include "../include/lustre_fld.h"
  57 #include "../include/lustre_mdc.h"
  58 #include "fld_internal.h"
  59
  60 /* TODO: these 3 functions are copies of flow-control code from mdc_lib.c
  61  * It should be common thing. The same about mdc RPC lock */
  62 static int fld_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
  63 {
  64         int rc;
  65
  66         client_obd_list_lock(&cli->cl_loi_list_lock);
  67         rc = list_empty(&mcw->mcw_entry);
  68         client_obd_list_unlock(&cli->cl_loi_list_lock);
  69         return rc;
  70 };
  71
  72 static void fld_enter_request(struct client_obd *cli)
  73 {
  74         struct mdc_cache_waiter mcw;
  75         struct l_wait_info lwi = { 0 };
  76
  77         client_obd_list_lock(&cli->cl_loi_list_lock);
  78         if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
  79                 list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
  80                 init_waitqueue_head(&mcw.mcw_waitq);
  81                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  82                 l_wait_event(mcw.mcw_waitq, fld_req_avail(cli, &mcw), &lwi);
  83         } else {
  84                 cli->cl_r_in_flight++;
  85                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  86         }
  87 }
  88
  89 static void fld_exit_request(struct client_obd *cli)
  90 {
  91         struct list_head *l, *tmp;
  92         struct mdc_cache_waiter *mcw;
  93
  94         client_obd_list_lock(&cli->cl_loi_list_lock);
  95         cli->cl_r_in_flight--;
  96         list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
  97
  98                 if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
  99                         /* No free request slots anymore */
 100                         break;
 101                 }
 102
 103                 mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
 104                 list_del_init(&mcw->mcw_entry);
 105                 cli->cl_r_in_flight++;
 106                 wake_up(&mcw->mcw_waitq);
 107         }
 108         client_obd_list_unlock(&cli->cl_loi_list_lock);
 109 }
 110
 111 static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
 112 {
 113         LASSERT(fld->lcf_count > 0);
 114         return do_div(seq, fld->lcf_count);
 115 }
 116
 117 static struct lu_fld_target *
 118 fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
 119 {
 120         struct lu_fld_target *target;
 121         int hash;
 122
 123         /* Because almost all of special sequence located in MDT0,
 124          * it should go to index 0 directly, instead of calculating
 125          * hash again, and also if other MDTs is not being connected,
 126          * the fld lookup requests(for seq on MDT0) should not be
 127          * blocked because of other MDTs */
 128         if (fid_seq_is_norm(seq))
 129                 hash = fld_rrb_hash(fld, seq);
 130         else
 131                 hash = 0;
 132
 133 again:
 134         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 135                 if (target->ft_idx == hash)
 136                         return target;
 137         }
 138
 139         if (hash != 0) {
 140                 /* It is possible the remote target(MDT) are not connected to
 141                  * with client yet, so we will refer this to MDT0, which should
 142                  * be connected during mount */
 143                 hash = 0;
 144                 goto again;
 145         }
 146
 147         CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
 148                 fld->lcf_name, hash, seq, fld->lcf_count);
 149
 150         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 151                 const char *srv_name = target->ft_srv != NULL  ?
 152                         target->ft_srv->lsf_name : "<null>";
 153                 const char *exp_name = target->ft_exp != NULL ?
 154                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 155                         "<null>";
 156
 157                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
 158                        target->ft_exp, exp_name, target->ft_srv,
 159                        srv_name, target->ft_idx);
 160         }
 161
 162         /*
 163          * If target is not found, there is logical error anyway, so here is
 164          * LBUG() to catch this situation.
 165          */
 166         LBUG();
 167         return NULL;
 168 }
 169
 170 struct lu_fld_hash fld_hash[] = {
 171         {
 172                 .fh_name = "RRB",
 173                 .fh_hash_func = fld_rrb_hash,
 174                 .fh_scan_func = fld_rrb_scan
 175         },
 176         {
 177                 NULL,
 178         }
 179 };
 180
 181 static struct lu_fld_target *
 182 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
 183 {
 184         struct lu_fld_target *target;
 185
 186         LASSERT(fld->lcf_hash != NULL);
 187
 188         spin_lock(&fld->lcf_lock);
 189         target = fld->lcf_hash->fh_scan_func(fld, seq);
 190         spin_unlock(&fld->lcf_lock);
 191
 192         if (target != NULL) {
 193                 CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
 194                        fld->lcf_name, target->ft_idx, seq);
 195         }
 196
 197         return target;
 198 }
 199
 200 /*
 201  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 202  * of FLD module.
 203  */
 204 int fld_client_add_target(struct lu_client_fld *fld,
 205                           struct lu_fld_target *tar)
 206 {
 207         const char *name;
 208         struct lu_fld_target *target, *tmp;
 209
 210         LASSERT(tar != NULL);
 211         name = fld_target_name(tar);
 212         LASSERT(name != NULL);
 213         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 214
 215         if (fld->lcf_flags != LUSTRE_FLD_INIT) {
 216                 CERROR("%s: Attempt to add target %s (idx %llu) on fly - skip it\n",
 217                         fld->lcf_name, name, tar->ft_idx);
 218                 return 0;
 219         }
 220         CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n",
 221                         fld->lcf_name, name, tar->ft_idx);
 222
 223         target = kzalloc(sizeof(*target), GFP_NOFS);
 224         if (!target)
 225                 return -ENOMEM;
 226
 227         spin_lock(&fld->lcf_lock);
 228         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 229                 if (tmp->ft_idx == tar->ft_idx) {
 230                         spin_unlock(&fld->lcf_lock);
 231                         kfree(target);
 232                         CERROR("Target %s exists in FLD and known as %s:#%llu\n",
 233                                name, fld_target_name(tmp), tmp->ft_idx);
 234                         return -EEXIST;
 235                 }
 236         }
 237
 238         target->ft_exp = tar->ft_exp;
 239         if (target->ft_exp != NULL)
 240                 class_export_get(target->ft_exp);
 241         target->ft_srv = tar->ft_srv;
 242         target->ft_idx = tar->ft_idx;
 243
 244         list_add_tail(&target->ft_chain,
 245                           &fld->lcf_targets);
 246
 247         fld->lcf_count++;
 248         spin_unlock(&fld->lcf_lock);
 249
 250         return 0;
 251 }
 252 EXPORT_SYMBOL(fld_client_add_target);
 253
 254 /* Remove export from FLD */
 255 int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
 256 {
 257         struct lu_fld_target *target, *tmp;
 258
 259         spin_lock(&fld->lcf_lock);
 260         list_for_each_entry_safe(target, tmp,
 261                                      &fld->lcf_targets, ft_chain) {
 262                 if (target->ft_idx == idx) {
 263                         fld->lcf_count--;
 264                         list_del(&target->ft_chain);
 265                         spin_unlock(&fld->lcf_lock);
 266
 267                         if (target->ft_exp != NULL)
 268                                 class_export_put(target->ft_exp);
 269
 270                         kfree(target);
 271                         return 0;
 272                 }
 273         }
 274         spin_unlock(&fld->lcf_lock);
 275         return -ENOENT;
 276 }
 277 EXPORT_SYMBOL(fld_client_del_target);
 278
 279 static struct dentry *fld_debugfs_dir;
 280
 281 static int fld_client_debugfs_init(struct lu_client_fld *fld)
 282 {
 283         int rc;
 284
 285         fld->lcf_debugfs_entry = ldebugfs_register(fld->lcf_name,
 286                                                    fld_debugfs_dir,
 287                                                    NULL, NULL);
 288
 289         if (IS_ERR_OR_NULL(fld->lcf_debugfs_entry)) {
 290                 CERROR("%s: LdebugFS failed in fld-init\n", fld->lcf_name);
 291                 rc = fld->lcf_debugfs_entry ? PTR_ERR(fld->lcf_debugfs_entry)
 292                                             : -ENOMEM;
 293                 fld->lcf_debugfs_entry = NULL;
 294                 return rc;
 295         }
 296
 297         rc = ldebugfs_add_vars(fld->lcf_debugfs_entry,
 298                                fld_client_debugfs_list, fld);
 299         if (rc) {
 300                 CERROR("%s: Can't init FLD debufs, rc %d\n", fld->lcf_name, rc);
 301                 goto out_cleanup;
 302         }
 303
 304         return 0;
 305
 306 out_cleanup:
 307         fld_client_debugfs_fini(fld);
 308         return rc;
 309 }
 310
 311 void fld_client_debugfs_fini(struct lu_client_fld *fld)
 312 {
 313         if (!IS_ERR_OR_NULL(fld->lcf_debugfs_entry))
 314                 ldebugfs_remove(&fld->lcf_debugfs_entry);
 315 }
 316 EXPORT_SYMBOL(fld_client_debugfs_fini);
 317
 318 static inline int hash_is_sane(int hash)
 319 {
 320         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 321 }
 322
 323 int fld_client_init(struct lu_client_fld *fld,
 324                     const char *prefix, int hash)
 325 {
 326         int cache_size, cache_threshold;
 327         int rc;
 328
 329         LASSERT(fld != NULL);
 330
 331         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 332                  "cli-%s", prefix);
 333
 334         if (!hash_is_sane(hash)) {
 335                 CERROR("%s: Wrong hash function %#x\n",
 336                        fld->lcf_name, hash);
 337                 return -EINVAL;
 338         }
 339
 340         fld->lcf_count = 0;
 341         spin_lock_init(&fld->lcf_lock);
 342         fld->lcf_hash = &fld_hash[hash];
 343         fld->lcf_flags = LUSTRE_FLD_INIT;
 344         INIT_LIST_HEAD(&fld->lcf_targets);
 345
 346         cache_size = FLD_CLIENT_CACHE_SIZE /
 347                 sizeof(struct fld_cache_entry);
 348
 349         cache_threshold = cache_size *
 350                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 351
 352         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 353                                         cache_size, cache_threshold);
 354         if (IS_ERR(fld->lcf_cache)) {
 355                 rc = PTR_ERR(fld->lcf_cache);
 356                 fld->lcf_cache = NULL;
 357                 goto out;
 358         }
 359
 360         rc = fld_client_debugfs_init(fld);
 361         if (rc)
 362                 goto out;
 363 out:
 364         if (rc)
 365                 fld_client_fini(fld);
 366         else
 367                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 368                        fld->lcf_name, fld->lcf_hash->fh_name);
 369         return rc;
 370 }
 371 EXPORT_SYMBOL(fld_client_init);
 372
 373 void fld_client_fini(struct lu_client_fld *fld)
 374 {
 375         struct lu_fld_target *target, *tmp;
 376
 377         spin_lock(&fld->lcf_lock);
 378         list_for_each_entry_safe(target, tmp,
 379                                      &fld->lcf_targets, ft_chain) {
 380                 fld->lcf_count--;
 381                 list_del(&target->ft_chain);
 382                 if (target->ft_exp != NULL)
 383                         class_export_put(target->ft_exp);
 384                 kfree(target);
 385         }
 386         spin_unlock(&fld->lcf_lock);
 387
 388         if (fld->lcf_cache != NULL) {
 389                 if (!IS_ERR(fld->lcf_cache))
 390                         fld_cache_fini(fld->lcf_cache);
 391                 fld->lcf_cache = NULL;
 392         }
 393 }
 394 EXPORT_SYMBOL(fld_client_fini);
 395
 396 int fld_client_rpc(struct obd_export *exp,
 397                    struct lu_seq_range *range, __u32 fld_op)
 398 {
 399         struct ptlrpc_request *req;
 400         struct lu_seq_range   *prange;
 401         __u32            *op;
 402         int                 rc;
 403         struct obd_import     *imp;
 404
 405         LASSERT(exp != NULL);
 406
 407         imp = class_exp2cliimp(exp);
 408         req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
 409                                         FLD_QUERY);
 410         if (req == NULL)
 411                 return -ENOMEM;
 412
 413         op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 414         *op = fld_op;
 415
 416         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 417         *prange = *range;
 418
 419         ptlrpc_request_set_replen(req);
 420         req->rq_request_portal = FLD_REQUEST_PORTAL;
 421         req->rq_reply_portal = MDC_REPLY_PORTAL;
 422         ptlrpc_at_set_req_timeout(req);
 423
 424         if (fld_op == FLD_LOOKUP &&
 425             imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
 426                 req->rq_allow_replay = 1;
 427
 428         if (fld_op != FLD_LOOKUP)
 429                 mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 430         fld_enter_request(&exp->exp_obd->u.cli);
 431         rc = ptlrpc_queue_wait(req);
 432         fld_exit_request(&exp->exp_obd->u.cli);
 433         if (fld_op != FLD_LOOKUP)
 434                 mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 435         if (rc)
 436                 goto out_req;
 437
 438         prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
 439         if (prange == NULL) {
 440                 rc = -EFAULT;
 441                 goto out_req;
 442         }
 443         *range = *prange;
 444 out_req:
 445         ptlrpc_req_finished(req);
 446         return rc;
 447 }
 448
 449 int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
 450                       __u32 flags, const struct lu_env *env)
 451 {
 452         struct lu_seq_range res = { 0 };
 453         struct lu_fld_target *target;
 454         int rc;
 455
 456         fld->lcf_flags |= LUSTRE_FLD_RUN;
 457
 458         rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
 459         if (rc == 0) {
 460                 *mds = res.lsr_index;
 461                 return 0;
 462         }
 463
 464         /* Can not find it in the cache */
 465         target = fld_client_get_target(fld, seq);
 466         LASSERT(target != NULL);
 467
 468         CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
 469                         fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
 470
 471         res.lsr_start = seq;
 472         fld_range_set_type(&res, flags);
 473         rc = fld_client_rpc(target->ft_exp, &res, FLD_LOOKUP);
 474
 475         if (rc == 0) {
 476                 *mds = res.lsr_index;
 477
 478                 fld_cache_insert(fld->lcf_cache, &res);
 479         }
 480         return rc;
 481 }
 482 EXPORT_SYMBOL(fld_client_lookup);
 483
 484 void fld_client_flush(struct lu_client_fld *fld)
 485 {
 486         fld_cache_flush(fld->lcf_cache);
 487 }
 488 EXPORT_SYMBOL(fld_client_flush);
 489
 490 static int __init fld_mod_init(void)
 491 {
 492         fld_debugfs_dir = ldebugfs_register(LUSTRE_FLD_NAME,
 493                                             debugfs_lustre_root,
 494                                             NULL, NULL);
 495         return PTR_ERR_OR_ZERO(fld_debugfs_dir);
 496 }
 497
 498 static void __exit fld_mod_exit(void)
 499 {
 500         if (!IS_ERR_OR_NULL(fld_debugfs_dir))
 501                 ldebugfs_remove(&fld_debugfs_dir);
 502 }
 503
 504 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 505 MODULE_DESCRIPTION("Lustre FLD");
 506 MODULE_LICENSE("GPL");
 507
 508 module_init(fld_mod_init)
 509 module_exit(fld_mod_exit)