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         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 135                 if (target->ft_idx == hash)
 136                         return target;
 137         }
 138
 139         CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
 140                 fld->lcf_name, hash, seq, fld->lcf_count);
 141
 142         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 143                 const char *srv_name = target->ft_srv != NULL  ?
 144                         target->ft_srv->lsf_name : "<null>";
 145                 const char *exp_name = target->ft_exp != NULL ?
 146                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 147                         "<null>";
 148
 149                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
 150                        target->ft_exp, exp_name, target->ft_srv,
 151                        srv_name, target->ft_idx);
 152         }
 153
 154         /*
 155          * If target is not found, there is logical error anyway, so here is
 156          * LBUG() to catch this situation.
 157          */
 158         LBUG();
 159         return NULL;
 160 }
 161
 162 struct lu_fld_hash fld_hash[] = {
 163         {
 164                 .fh_name = "RRB",
 165                 .fh_hash_func = fld_rrb_hash,
 166                 .fh_scan_func = fld_rrb_scan
 167         },
 168         {
 169                 NULL,
 170         }
 171 };
 172
 173 static struct lu_fld_target *
 174 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
 175 {
 176         struct lu_fld_target *target;
 177
 178         LASSERT(fld->lcf_hash != NULL);
 179
 180         spin_lock(&fld->lcf_lock);
 181         target = fld->lcf_hash->fh_scan_func(fld, seq);
 182         spin_unlock(&fld->lcf_lock);
 183
 184         if (target != NULL) {
 185                 CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
 186                        fld->lcf_name, target->ft_idx, seq);
 187         }
 188
 189         return target;
 190 }
 191
 192 /*
 193  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 194  * of FLD module.
 195  */
 196 int fld_client_add_target(struct lu_client_fld *fld,
 197                           struct lu_fld_target *tar)
 198 {
 199         const char *name;
 200         struct lu_fld_target *target, *tmp;
 201
 202         LASSERT(tar != NULL);
 203         name = fld_target_name(tar);
 204         LASSERT(name != NULL);
 205         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 206
 207         if (fld->lcf_flags != LUSTRE_FLD_INIT) {
 208                 CERROR("%s: Attempt to add target %s (idx %llu) on fly - skip it\n",
 209                         fld->lcf_name, name, tar->ft_idx);
 210                 return 0;
 211         } else {
 212                 CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n",
 213                        fld->lcf_name, name, tar->ft_idx);
 214         }
 215
 216         OBD_ALLOC_PTR(target);
 217         if (target == NULL)
 218                 return -ENOMEM;
 219
 220         spin_lock(&fld->lcf_lock);
 221         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 222                 if (tmp->ft_idx == tar->ft_idx) {
 223                         spin_unlock(&fld->lcf_lock);
 224                         OBD_FREE_PTR(target);
 225                         CERROR("Target %s exists in FLD and known as %s:#%llu\n",
 226                                name, fld_target_name(tmp), tmp->ft_idx);
 227                         return -EEXIST;
 228                 }
 229         }
 230
 231         target->ft_exp = tar->ft_exp;
 232         if (target->ft_exp != NULL)
 233                 class_export_get(target->ft_exp);
 234         target->ft_srv = tar->ft_srv;
 235         target->ft_idx = tar->ft_idx;
 236
 237         list_add_tail(&target->ft_chain,
 238                           &fld->lcf_targets);
 239
 240         fld->lcf_count++;
 241         spin_unlock(&fld->lcf_lock);
 242
 243         return 0;
 244 }
 245 EXPORT_SYMBOL(fld_client_add_target);
 246
 247 /* Remove export from FLD */
 248 int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
 249 {
 250         struct lu_fld_target *target, *tmp;
 251
 252         spin_lock(&fld->lcf_lock);
 253         list_for_each_entry_safe(target, tmp,
 254                                      &fld->lcf_targets, ft_chain) {
 255                 if (target->ft_idx == idx) {
 256                         fld->lcf_count--;
 257                         list_del(&target->ft_chain);
 258                         spin_unlock(&fld->lcf_lock);
 259
 260                         if (target->ft_exp != NULL)
 261                                 class_export_put(target->ft_exp);
 262
 263                         OBD_FREE_PTR(target);
 264                         return 0;
 265                 }
 266         }
 267         spin_unlock(&fld->lcf_lock);
 268         return -ENOENT;
 269 }
 270 EXPORT_SYMBOL(fld_client_del_target);
 271
 272 struct proc_dir_entry *fld_type_proc_dir = NULL;
 273
 274 #if defined (CONFIG_PROC_FS)
 275 static int fld_client_proc_init(struct lu_client_fld *fld)
 276 {
 277         int rc;
 278
 279         fld->lcf_proc_dir = lprocfs_register(fld->lcf_name,
 280                                              fld_type_proc_dir,
 281                                              NULL, NULL);
 282
 283         if (IS_ERR(fld->lcf_proc_dir)) {
 284                 CERROR("%s: LProcFS failed in fld-init\n",
 285                        fld->lcf_name);
 286                 rc = PTR_ERR(fld->lcf_proc_dir);
 287                 return rc;
 288         }
 289
 290         rc = lprocfs_add_vars(fld->lcf_proc_dir,
 291                               fld_client_proc_list, fld);
 292         if (rc) {
 293                 CERROR("%s: Can't init FLD proc, rc %d\n",
 294                        fld->lcf_name, rc);
 295                 goto out_cleanup;
 296         }
 297
 298         return 0;
 299
 300 out_cleanup:
 301         fld_client_proc_fini(fld);
 302         return rc;
 303 }
 304
 305 void fld_client_proc_fini(struct lu_client_fld *fld)
 306 {
 307         if (fld->lcf_proc_dir) {
 308                 if (!IS_ERR(fld->lcf_proc_dir))
 309                         lprocfs_remove(&fld->lcf_proc_dir);
 310                 fld->lcf_proc_dir = NULL;
 311         }
 312 }
 313 #else
 314 static int fld_client_proc_init(struct lu_client_fld *fld)
 315 {
 316         return 0;
 317 }
 318
 319 void fld_client_proc_fini(struct lu_client_fld *fld)
 320 {
 321         return;
 322 }
 323 #endif
 324 EXPORT_SYMBOL(fld_client_proc_fini);
 325
 326 static inline int hash_is_sane(int hash)
 327 {
 328         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 329 }
 330
 331 int fld_client_init(struct lu_client_fld *fld,
 332                     const char *prefix, int hash)
 333 {
 334         int cache_size, cache_threshold;
 335         int rc;
 336
 337         LASSERT(fld != NULL);
 338
 339         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 340                  "cli-%s", prefix);
 341
 342         if (!hash_is_sane(hash)) {
 343                 CERROR("%s: Wrong hash function %#x\n",
 344                        fld->lcf_name, hash);
 345                 return -EINVAL;
 346         }
 347
 348         fld->lcf_count = 0;
 349         spin_lock_init(&fld->lcf_lock);
 350         fld->lcf_hash = &fld_hash[hash];
 351         fld->lcf_flags = LUSTRE_FLD_INIT;
 352         INIT_LIST_HEAD(&fld->lcf_targets);
 353
 354         cache_size = FLD_CLIENT_CACHE_SIZE /
 355                 sizeof(struct fld_cache_entry);
 356
 357         cache_threshold = cache_size *
 358                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 359
 360         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 361                                         cache_size, cache_threshold);
 362         if (IS_ERR(fld->lcf_cache)) {
 363                 rc = PTR_ERR(fld->lcf_cache);
 364                 fld->lcf_cache = NULL;
 365                 goto out;
 366         }
 367
 368         rc = fld_client_proc_init(fld);
 369         if (rc)
 370                 goto out;
 371 out:
 372         if (rc)
 373                 fld_client_fini(fld);
 374         else
 375                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 376                        fld->lcf_name, fld->lcf_hash->fh_name);
 377         return rc;
 378 }
 379 EXPORT_SYMBOL(fld_client_init);
 380
 381 void fld_client_fini(struct lu_client_fld *fld)
 382 {
 383         struct lu_fld_target *target, *tmp;
 384
 385         spin_lock(&fld->lcf_lock);
 386         list_for_each_entry_safe(target, tmp,
 387                                      &fld->lcf_targets, ft_chain) {
 388                 fld->lcf_count--;
 389                 list_del(&target->ft_chain);
 390                 if (target->ft_exp != NULL)
 391                         class_export_put(target->ft_exp);
 392                 OBD_FREE_PTR(target);
 393         }
 394         spin_unlock(&fld->lcf_lock);
 395
 396         if (fld->lcf_cache != NULL) {
 397                 if (!IS_ERR(fld->lcf_cache))
 398                         fld_cache_fini(fld->lcf_cache);
 399                 fld->lcf_cache = NULL;
 400         }
 401 }
 402 EXPORT_SYMBOL(fld_client_fini);
 403
 404 int fld_client_rpc(struct obd_export *exp,
 405                    struct lu_seq_range *range, __u32 fld_op)
 406 {
 407         struct ptlrpc_request *req;
 408         struct lu_seq_range   *prange;
 409         __u32            *op;
 410         int                 rc;
 411         struct obd_import     *imp;
 412
 413         LASSERT(exp != NULL);
 414
 415         imp = class_exp2cliimp(exp);
 416         req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
 417                                         FLD_QUERY);
 418         if (req == NULL)
 419                 return -ENOMEM;
 420
 421         op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 422         *op = fld_op;
 423
 424         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 425         *prange = *range;
 426
 427         ptlrpc_request_set_replen(req);
 428         req->rq_request_portal = FLD_REQUEST_PORTAL;
 429         req->rq_reply_portal = MDC_REPLY_PORTAL;
 430         ptlrpc_at_set_req_timeout(req);
 431
 432         if (fld_op == FLD_LOOKUP &&
 433             imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
 434                 req->rq_allow_replay = 1;
 435
 436         if (fld_op != FLD_LOOKUP)
 437                 mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 438         fld_enter_request(&exp->exp_obd->u.cli);
 439         rc = ptlrpc_queue_wait(req);
 440         fld_exit_request(&exp->exp_obd->u.cli);
 441         if (fld_op != FLD_LOOKUP)
 442                 mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 443         if (rc)
 444                 goto out_req;
 445
 446         prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
 447         if (prange == NULL) {
 448                 rc = -EFAULT;
 449                 goto out_req;
 450         }
 451         *range = *prange;
 452 out_req:
 453         ptlrpc_req_finished(req);
 454         return rc;
 455 }
 456
 457 int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
 458                       __u32 flags, const struct lu_env *env)
 459 {
 460         struct lu_seq_range res = { 0 };
 461         struct lu_fld_target *target;
 462         int rc;
 463
 464         fld->lcf_flags |= LUSTRE_FLD_RUN;
 465
 466         rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
 467         if (rc == 0) {
 468                 *mds = res.lsr_index;
 469                 return 0;
 470         }
 471
 472         /* Can not find it in the cache */
 473         target = fld_client_get_target(fld, seq);
 474         LASSERT(target != NULL);
 475
 476         CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
 477                         fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
 478
 479         res.lsr_start = seq;
 480         fld_range_set_type(&res, flags);
 481         rc = fld_client_rpc(target->ft_exp, &res, FLD_LOOKUP);
 482
 483         if (rc == 0) {
 484                 *mds = res.lsr_index;
 485
 486                 fld_cache_insert(fld->lcf_cache, &res);
 487         }
 488         return rc;
 489 }
 490 EXPORT_SYMBOL(fld_client_lookup);
 491
 492 void fld_client_flush(struct lu_client_fld *fld)
 493 {
 494         fld_cache_flush(fld->lcf_cache);
 495 }
 496 EXPORT_SYMBOL(fld_client_flush);
 497
 498 static int __init fld_mod_init(void)
 499 {
 500         fld_type_proc_dir = lprocfs_register(LUSTRE_FLD_NAME,
 501                                              proc_lustre_root,
 502                                              NULL, NULL);
 503         return PTR_ERR_OR_ZERO(fld_type_proc_dir);
 504 }
 505
 506 static void __exit fld_mod_exit(void)
 507 {
 508         if (fld_type_proc_dir != NULL && !IS_ERR(fld_type_proc_dir)) {
 509                 lprocfs_remove(&fld_type_proc_dir);
 510                 fld_type_proc_dir = NULL;
 511         }
 512 }
 513
 514 MODULE_AUTHOR("Sun Microsystems, Inc. <http://www.lustre.org/>");
 515 MODULE_DESCRIPTION("Lustre FLD");
 516 MODULE_LICENSE("GPL");
 517
 518 module_init(fld_mod_init)
 519 module_exit(fld_mod_exit)