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/dt_object.h"
  56 #include "../include/lustre_req_layout.h"
  57 #include "../include/lustre_fld.h"
  58 #include "../include/lustre_mdc.h"
  59 #include "fld_internal.h"
  60
  61 /* TODO: these 3 functions are copies of flow-control code from mdc_lib.c
  62  * It should be common thing. The same about mdc RPC lock */
  63 static int fld_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
  64 {
  65         int rc;
  66
  67         client_obd_list_lock(&cli->cl_loi_list_lock);
  68         rc = list_empty(&mcw->mcw_entry);
  69         client_obd_list_unlock(&cli->cl_loi_list_lock);
  70         return rc;
  71 };
  72
  73 static void fld_enter_request(struct client_obd *cli)
  74 {
  75         struct mdc_cache_waiter mcw;
  76         struct l_wait_info lwi = { 0 };
  77
  78         client_obd_list_lock(&cli->cl_loi_list_lock);
  79         if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
  80                 list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
  81                 init_waitqueue_head(&mcw.mcw_waitq);
  82                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  83                 l_wait_event(mcw.mcw_waitq, fld_req_avail(cli, &mcw), &lwi);
  84         } else {
  85                 cli->cl_r_in_flight++;
  86                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  87         }
  88 }
  89
  90 static void fld_exit_request(struct client_obd *cli)
  91 {
  92         struct list_head *l, *tmp;
  93         struct mdc_cache_waiter *mcw;
  94
  95         client_obd_list_lock(&cli->cl_loi_list_lock);
  96         cli->cl_r_in_flight--;
  97         list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
  98
  99                 if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
 100                         /* No free request slots anymore */
 101                         break;
 102                 }
 103
 104                 mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
 105                 list_del_init(&mcw->mcw_entry);
 106                 cli->cl_r_in_flight++;
 107                 wake_up(&mcw->mcw_waitq);
 108         }
 109         client_obd_list_unlock(&cli->cl_loi_list_lock);
 110 }
 111
 112 static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
 113 {
 114         LASSERT(fld->lcf_count > 0);
 115         return do_div(seq, fld->lcf_count);
 116 }
 117
 118 static struct lu_fld_target *
 119 fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
 120 {
 121         struct lu_fld_target *target;
 122         int hash;
 123
 124         /* Because almost all of special sequence located in MDT0,
 125          * it should go to index 0 directly, instead of calculating
 126          * hash again, and also if other MDTs is not being connected,
 127          * the fld lookup requests(for seq on MDT0) should not be
 128          * blocked because of other MDTs */
 129         if (fid_seq_is_norm(seq))
 130                 hash = fld_rrb_hash(fld, seq);
 131         else
 132                 hash = 0;
 133
 134 again:
 135         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 136                 if (target->ft_idx == hash)
 137                         return target;
 138         }
 139
 140         if (hash != 0) {
 141                 /* It is possible the remote target(MDT) are not connected to
 142                  * with client yet, so we will refer this to MDT0, which should
 143                  * be connected during mount */
 144                 hash = 0;
 145                 goto again;
 146         }
 147
 148         CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
 149                 fld->lcf_name, hash, seq, fld->lcf_count);
 150
 151         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 152                 const char *srv_name = target->ft_srv != NULL  ?
 153                         target->ft_srv->lsf_name : "<null>";
 154                 const char *exp_name = target->ft_exp != NULL ?
 155                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 156                         "<null>";
 157
 158                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
 159                        target->ft_exp, exp_name, target->ft_srv,
 160                        srv_name, target->ft_idx);
 161         }
 162
 163         /*
 164          * If target is not found, there is logical error anyway, so here is
 165          * LBUG() to catch this situation.
 166          */
 167         LBUG();
 168         return NULL;
 169 }
 170
 171 struct lu_fld_hash fld_hash[] = {
 172         {
 173                 .fh_name = "RRB",
 174                 .fh_hash_func = fld_rrb_hash,
 175                 .fh_scan_func = fld_rrb_scan
 176         },
 177         {
 178                 NULL,
 179         }
 180 };
 181
 182 static struct lu_fld_target *
 183 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
 184 {
 185         struct lu_fld_target *target;
 186
 187         LASSERT(fld->lcf_hash != NULL);
 188
 189         spin_lock(&fld->lcf_lock);
 190         target = fld->lcf_hash->fh_scan_func(fld, seq);
 191         spin_unlock(&fld->lcf_lock);
 192
 193         if (target != NULL) {
 194                 CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
 195                        fld->lcf_name, target->ft_idx, seq);
 196         }
 197
 198         return target;
 199 }
 200
 201 /*
 202  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 203  * of FLD module.
 204  */
 205 int fld_client_add_target(struct lu_client_fld *fld,
 206                           struct lu_fld_target *tar)
 207 {
 208         const char *name;
 209         struct lu_fld_target *target, *tmp;
 210
 211         LASSERT(tar != NULL);
 212         name = fld_target_name(tar);
 213         LASSERT(name != NULL);
 214         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 215
 216         if (fld->lcf_flags != LUSTRE_FLD_INIT) {
 217                 CERROR("%s: Attempt to add target %s (idx %llu) on fly - skip it\n",
 218                         fld->lcf_name, name, tar->ft_idx);
 219                 return 0;
 220         }
 221         CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n",
 222                         fld->lcf_name, name, tar->ft_idx);
 223
 224         OBD_ALLOC_PTR(target);
 225         if (target == NULL)
 226                 return -ENOMEM;
 227
 228         spin_lock(&fld->lcf_lock);
 229         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 230                 if (tmp->ft_idx == tar->ft_idx) {
 231                         spin_unlock(&fld->lcf_lock);
 232                         OBD_FREE_PTR(target);
 233                         CERROR("Target %s exists in FLD and known as %s:#%llu\n",
 234                                name, fld_target_name(tmp), tmp->ft_idx);
 235                         return -EEXIST;
 236                 }
 237         }
 238
 239         target->ft_exp = tar->ft_exp;
 240         if (target->ft_exp != NULL)
 241                 class_export_get(target->ft_exp);
 242         target->ft_srv = tar->ft_srv;
 243         target->ft_idx = tar->ft_idx;
 244
 245         list_add_tail(&target->ft_chain,
 246                           &fld->lcf_targets);
 247
 248         fld->lcf_count++;
 249         spin_unlock(&fld->lcf_lock);
 250
 251         return 0;
 252 }
 253 EXPORT_SYMBOL(fld_client_add_target);
 254
 255 /* Remove export from FLD */
 256 int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
 257 {
 258         struct lu_fld_target *target, *tmp;
 259
 260         spin_lock(&fld->lcf_lock);
 261         list_for_each_entry_safe(target, tmp,
 262                                      &fld->lcf_targets, ft_chain) {
 263                 if (target->ft_idx == idx) {
 264                         fld->lcf_count--;
 265                         list_del(&target->ft_chain);
 266                         spin_unlock(&fld->lcf_lock);
 267
 268                         if (target->ft_exp != NULL)
 269                                 class_export_put(target->ft_exp);
 270
 271                         OBD_FREE_PTR(target);
 272                         return 0;
 273                 }
 274         }
 275         spin_unlock(&fld->lcf_lock);
 276         return -ENOENT;
 277 }
 278 EXPORT_SYMBOL(fld_client_del_target);
 279
 280 static struct proc_dir_entry *fld_type_proc_dir;
 281
 282 #if defined(CONFIG_PROC_FS)
 283 static int fld_client_proc_init(struct lu_client_fld *fld)
 284 {
 285         int rc;
 286
 287         fld->lcf_proc_dir = lprocfs_register(fld->lcf_name,
 288                                              fld_type_proc_dir,
 289                                              NULL, NULL);
 290
 291         if (IS_ERR(fld->lcf_proc_dir)) {
 292                 CERROR("%s: LProcFS failed in fld-init\n",
 293                        fld->lcf_name);
 294                 rc = PTR_ERR(fld->lcf_proc_dir);
 295                 return rc;
 296         }
 297
 298         rc = lprocfs_add_vars(fld->lcf_proc_dir,
 299                               fld_client_proc_list, fld);
 300         if (rc) {
 301                 CERROR("%s: Can't init FLD proc, rc %d\n",
 302                        fld->lcf_name, rc);
 303                 goto out_cleanup;
 304         }
 305
 306         return 0;
 307
 308 out_cleanup:
 309         fld_client_proc_fini(fld);
 310         return rc;
 311 }
 312
 313 void fld_client_proc_fini(struct lu_client_fld *fld)
 314 {
 315         if (fld->lcf_proc_dir) {
 316                 if (!IS_ERR(fld->lcf_proc_dir))
 317                         lprocfs_remove(&fld->lcf_proc_dir);
 318                 fld->lcf_proc_dir = NULL;
 319         }
 320 }
 321 #else
 322 static int fld_client_proc_init(struct lu_client_fld *fld)
 323 {
 324         return 0;
 325 }
 326
 327 void fld_client_proc_fini(struct lu_client_fld *fld)
 328 {
 329 }
 330 #endif
 331 EXPORT_SYMBOL(fld_client_proc_fini);
 332
 333 static inline int hash_is_sane(int hash)
 334 {
 335         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 336 }
 337
 338 int fld_client_init(struct lu_client_fld *fld,
 339                     const char *prefix, int hash)
 340 {
 341         int cache_size, cache_threshold;
 342         int rc;
 343
 344         LASSERT(fld != NULL);
 345
 346         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 347                  "cli-%s", prefix);
 348
 349         if (!hash_is_sane(hash)) {
 350                 CERROR("%s: Wrong hash function %#x\n",
 351                        fld->lcf_name, hash);
 352                 return -EINVAL;
 353         }
 354
 355         fld->lcf_count = 0;
 356         spin_lock_init(&fld->lcf_lock);
 357         fld->lcf_hash = &fld_hash[hash];
 358         fld->lcf_flags = LUSTRE_FLD_INIT;
 359         INIT_LIST_HEAD(&fld->lcf_targets);
 360
 361         cache_size = FLD_CLIENT_CACHE_SIZE /
 362                 sizeof(struct fld_cache_entry);
 363
 364         cache_threshold = cache_size *
 365                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 366
 367         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 368                                         cache_size, cache_threshold);
 369         if (IS_ERR(fld->lcf_cache)) {
 370                 rc = PTR_ERR(fld->lcf_cache);
 371                 fld->lcf_cache = NULL;
 372                 goto out;
 373         }
 374
 375         rc = fld_client_proc_init(fld);
 376         if (rc)
 377                 goto out;
 378 out:
 379         if (rc)
 380                 fld_client_fini(fld);
 381         else
 382                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 383                        fld->lcf_name, fld->lcf_hash->fh_name);
 384         return rc;
 385 }
 386 EXPORT_SYMBOL(fld_client_init);
 387
 388 void fld_client_fini(struct lu_client_fld *fld)
 389 {
 390         struct lu_fld_target *target, *tmp;
 391
 392         spin_lock(&fld->lcf_lock);
 393         list_for_each_entry_safe(target, tmp,
 394                                      &fld->lcf_targets, ft_chain) {
 395                 fld->lcf_count--;
 396                 list_del(&target->ft_chain);
 397                 if (target->ft_exp != NULL)
 398                         class_export_put(target->ft_exp);
 399                 OBD_FREE_PTR(target);
 400         }
 401         spin_unlock(&fld->lcf_lock);
 402
 403         if (fld->lcf_cache != NULL) {
 404                 if (!IS_ERR(fld->lcf_cache))
 405                         fld_cache_fini(fld->lcf_cache);
 406                 fld->lcf_cache = NULL;
 407         }
 408 }
 409 EXPORT_SYMBOL(fld_client_fini);
 410
 411 int fld_client_rpc(struct obd_export *exp,
 412                    struct lu_seq_range *range, __u32 fld_op)
 413 {
 414         struct ptlrpc_request *req;
 415         struct lu_seq_range   *prange;
 416         __u32            *op;
 417         int                 rc;
 418         struct obd_import     *imp;
 419
 420         LASSERT(exp != NULL);
 421
 422         imp = class_exp2cliimp(exp);
 423         req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
 424                                         FLD_QUERY);
 425         if (req == NULL)
 426                 return -ENOMEM;
 427
 428         op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 429         *op = fld_op;
 430
 431         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 432         *prange = *range;
 433
 434         ptlrpc_request_set_replen(req);
 435         req->rq_request_portal = FLD_REQUEST_PORTAL;
 436         req->rq_reply_portal = MDC_REPLY_PORTAL;
 437         ptlrpc_at_set_req_timeout(req);
 438
 439         if (fld_op == FLD_LOOKUP &&
 440             imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
 441                 req->rq_allow_replay = 1;
 442
 443         if (fld_op != FLD_LOOKUP)
 444                 mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 445         fld_enter_request(&exp->exp_obd->u.cli);
 446         rc = ptlrpc_queue_wait(req);
 447         fld_exit_request(&exp->exp_obd->u.cli);
 448         if (fld_op != FLD_LOOKUP)
 449                 mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 450         if (rc)
 451                 goto out_req;
 452
 453         prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
 454         if (prange == NULL) {
 455                 rc = -EFAULT;
 456                 goto out_req;
 457         }
 458         *range = *prange;
 459 out_req:
 460         ptlrpc_req_finished(req);
 461         return rc;
 462 }
 463
 464 int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
 465                       __u32 flags, const struct lu_env *env)
 466 {
 467         struct lu_seq_range res = { 0 };
 468         struct lu_fld_target *target;
 469         int rc;
 470
 471         fld->lcf_flags |= LUSTRE_FLD_RUN;
 472
 473         rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
 474         if (rc == 0) {
 475                 *mds = res.lsr_index;
 476                 return 0;
 477         }
 478
 479         /* Can not find it in the cache */
 480         target = fld_client_get_target(fld, seq);
 481         LASSERT(target != NULL);
 482
 483         CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
 484                         fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
 485
 486         res.lsr_start = seq;
 487         fld_range_set_type(&res, flags);
 488         rc = fld_client_rpc(target->ft_exp, &res, FLD_LOOKUP);
 489
 490         if (rc == 0) {
 491                 *mds = res.lsr_index;
 492
 493                 fld_cache_insert(fld->lcf_cache, &res);
 494         }
 495         return rc;
 496 }
 497 EXPORT_SYMBOL(fld_client_lookup);
 498
 499 void fld_client_flush(struct lu_client_fld *fld)
 500 {
 501         fld_cache_flush(fld->lcf_cache);
 502 }
 503 EXPORT_SYMBOL(fld_client_flush);
 504
 505 static int __init fld_mod_init(void)
 506 {
 507         fld_type_proc_dir = lprocfs_register(LUSTRE_FLD_NAME,
 508                                              proc_lustre_root,
 509                                              NULL, NULL);
 510         return PTR_ERR_OR_ZERO(fld_type_proc_dir);
 511 }
 512
 513 static void __exit fld_mod_exit(void)
 514 {
 515         if (fld_type_proc_dir != NULL && !IS_ERR(fld_type_proc_dir)) {
 516                 lprocfs_remove(&fld_type_proc_dir);
 517                 fld_type_proc_dir = NULL;
 518         }
 519 }
 520
 521 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 522 MODULE_DESCRIPTION("Lustre FLD");
 523 MODULE_LICENSE("GPL");
 524
 525 module_init(fld_mod_init)
 526 module_exit(fld_mod_exit)