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 <obd.h>
  50 #include <obd_class.h>
  51 #include <lustre_ver.h>
  52 #include <obd_support.h>
  53 #include <lprocfs_status.h>
  54
  55 #include <dt_object.h>
  56 #include <md_object.h>
  57 #include <lustre_req_layout.h>
  58 #include <lustre_fld.h>
  59 #include <lustre_mdc.h>
  60 #include "fld_internal.h"
  61
  62 /* TODO: these 3 functions are copies of flow-control code from mdc_lib.c
  63  * It should be common thing. The same about mdc RPC lock */
  64 static int fld_req_avail(struct client_obd *cli, struct mdc_cache_waiter *mcw)
  65 {
  66         int rc;
  67
  68         client_obd_list_lock(&cli->cl_loi_list_lock);
  69         rc = list_empty(&mcw->mcw_entry);
  70         client_obd_list_unlock(&cli->cl_loi_list_lock);
  71         return rc;
  72 };
  73
  74 static void fld_enter_request(struct client_obd *cli)
  75 {
  76         struct mdc_cache_waiter mcw;
  77         struct l_wait_info lwi = { 0 };
  78
  79         client_obd_list_lock(&cli->cl_loi_list_lock);
  80         if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
  81                 list_add_tail(&mcw.mcw_entry, &cli->cl_cache_waiters);
  82                 init_waitqueue_head(&mcw.mcw_waitq);
  83                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  84                 l_wait_event(mcw.mcw_waitq, fld_req_avail(cli, &mcw), &lwi);
  85         } else {
  86                 cli->cl_r_in_flight++;
  87                 client_obd_list_unlock(&cli->cl_loi_list_lock);
  88         }
  89 }
  90
  91 static void fld_exit_request(struct client_obd *cli)
  92 {
  93         struct list_head *l, *tmp;
  94         struct mdc_cache_waiter *mcw;
  95
  96         client_obd_list_lock(&cli->cl_loi_list_lock);
  97         cli->cl_r_in_flight--;
  98         list_for_each_safe(l, tmp, &cli->cl_cache_waiters) {
  99
 100                 if (cli->cl_r_in_flight >= cli->cl_max_rpcs_in_flight) {
 101                         /* No free request slots anymore */
 102                         break;
 103                 }
 104
 105                 mcw = list_entry(l, struct mdc_cache_waiter, mcw_entry);
 106                 list_del_init(&mcw->mcw_entry);
 107                 cli->cl_r_in_flight++;
 108                 wake_up(&mcw->mcw_waitq);
 109         }
 110         client_obd_list_unlock(&cli->cl_loi_list_lock);
 111 }
 112
 113 static int fld_rrb_hash(struct lu_client_fld *fld,
 114                         seqno_t seq)
 115 {
 116         LASSERT(fld->lcf_count > 0);
 117         return do_div(seq, fld->lcf_count);
 118 }
 119
 120 static struct lu_fld_target *
 121 fld_rrb_scan(struct lu_client_fld *fld, seqno_t seq)
 122 {
 123         struct lu_fld_target *target;
 124         int hash;
 125
 126         /* Because almost all of special sequence located in MDT0,
 127          * it should go to index 0 directly, instead of calculating
 128          * hash again, and also if other MDTs is not being connected,
 129          * the fld lookup requests(for seq on MDT0) should not be
 130          * blocked because of other MDTs */
 131         if (fid_seq_is_norm(seq))
 132                 hash = fld_rrb_hash(fld, seq);
 133         else
 134                 hash = 0;
 135
 136         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 137                 if (target->ft_idx == hash)
 138                         return target;
 139         }
 140
 141         CERROR("%s: Can't find target by hash %d (seq "LPX64"). Targets (%d):\n",
 142                 fld->lcf_name, hash, seq, fld->lcf_count);
 143
 144         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 145                 const char *srv_name = target->ft_srv != NULL  ?
 146                         target->ft_srv->lsf_name : "<null>";
 147                 const char *exp_name = target->ft_exp != NULL ?
 148                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 149                         "<null>";
 150
 151                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: "LPU64"\n",
 152                        target->ft_exp, exp_name, target->ft_srv,
 153                        srv_name, target->ft_idx);
 154         }
 155
 156         /*
 157          * If target is not found, there is logical error anyway, so here is
 158          * LBUG() to catch this situation.
 159          */
 160         LBUG();
 161         return NULL;
 162 }
 163
 164 struct lu_fld_hash fld_hash[] = {
 165         {
 166                 .fh_name = "RRB",
 167                 .fh_hash_func = fld_rrb_hash,
 168                 .fh_scan_func = fld_rrb_scan
 169         },
 170         {
 171                 0,
 172         }
 173 };
 174
 175 static struct lu_fld_target *
 176 fld_client_get_target(struct lu_client_fld *fld, seqno_t seq)
 177 {
 178         struct lu_fld_target *target;
 179
 180         LASSERT(fld->lcf_hash != NULL);
 181
 182         spin_lock(&fld->lcf_lock);
 183         target = fld->lcf_hash->fh_scan_func(fld, seq);
 184         spin_unlock(&fld->lcf_lock);
 185
 186         if (target != NULL) {
 187                 CDEBUG(D_INFO, "%s: Found target (idx "LPU64
 188                        ") by seq "LPX64"\n", fld->lcf_name,
 189                        target->ft_idx, seq);
 190         }
 191
 192         return target;
 193 }
 194
 195 /*
 196  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 197  * of FLD module.
 198  */
 199 int fld_client_add_target(struct lu_client_fld *fld,
 200                           struct lu_fld_target *tar)
 201 {
 202         const char *name;
 203         struct lu_fld_target *target, *tmp;
 204
 205         LASSERT(tar != NULL);
 206         name = fld_target_name(tar);
 207         LASSERT(name != NULL);
 208         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 209
 210         if (fld->lcf_flags != LUSTRE_FLD_INIT) {
 211                 CERROR("%s: Attempt to add target %s (idx "LPU64") on fly - skip it\n",
 212                         fld->lcf_name, name, tar->ft_idx);
 213                 return 0;
 214         } else {
 215                 CDEBUG(D_INFO, "%s: Adding target %s (idx "
 216                        LPU64")\n", fld->lcf_name, name, tar->ft_idx);
 217         }
 218
 219         OBD_ALLOC_PTR(target);
 220         if (target == NULL)
 221                 return -ENOMEM;
 222
 223         spin_lock(&fld->lcf_lock);
 224         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 225                 if (tmp->ft_idx == tar->ft_idx) {
 226                         spin_unlock(&fld->lcf_lock);
 227                         OBD_FREE_PTR(target);
 228                         CERROR("Target %s exists in FLD and known as %s:#"LPU64"\n",
 229                                name, fld_target_name(tmp), tmp->ft_idx);
 230                         return -EEXIST;
 231                 }
 232         }
 233
 234         target->ft_exp = tar->ft_exp;
 235         if (target->ft_exp != NULL)
 236                 class_export_get(target->ft_exp);
 237         target->ft_srv = tar->ft_srv;
 238         target->ft_idx = tar->ft_idx;
 239
 240         list_add_tail(&target->ft_chain,
 241                           &fld->lcf_targets);
 242
 243         fld->lcf_count++;
 244         spin_unlock(&fld->lcf_lock);
 245
 246         return 0;
 247 }
 248 EXPORT_SYMBOL(fld_client_add_target);
 249
 250 /* Remove export from FLD */
 251 int fld_client_del_target(struct lu_client_fld *fld, __u64 idx)
 252 {
 253         struct lu_fld_target *target, *tmp;
 254
 255         spin_lock(&fld->lcf_lock);
 256         list_for_each_entry_safe(target, tmp,
 257                                      &fld->lcf_targets, ft_chain) {
 258                 if (target->ft_idx == idx) {
 259                         fld->lcf_count--;
 260                         list_del(&target->ft_chain);
 261                         spin_unlock(&fld->lcf_lock);
 262
 263                         if (target->ft_exp != NULL)
 264                                 class_export_put(target->ft_exp);
 265
 266                         OBD_FREE_PTR(target);
 267                         return 0;
 268                 }
 269         }
 270         spin_unlock(&fld->lcf_lock);
 271         return -ENOENT;
 272 }
 273 EXPORT_SYMBOL(fld_client_del_target);
 274
 275 struct proc_dir_entry *fld_type_proc_dir = NULL;
 276
 277 #ifdef LPROCFS
 278 static int fld_client_proc_init(struct lu_client_fld *fld)
 279 {
 280         int rc;
 281
 282         fld->lcf_proc_dir = lprocfs_register(fld->lcf_name,
 283                                              fld_type_proc_dir,
 284                                              NULL, NULL);
 285
 286         if (IS_ERR(fld->lcf_proc_dir)) {
 287                 CERROR("%s: LProcFS failed in fld-init\n",
 288                        fld->lcf_name);
 289                 rc = PTR_ERR(fld->lcf_proc_dir);
 290                 return rc;
 291         }
 292
 293         rc = lprocfs_add_vars(fld->lcf_proc_dir,
 294                               fld_client_proc_list, fld);
 295         if (rc) {
 296                 CERROR("%s: Can't init FLD proc, rc %d\n",
 297                        fld->lcf_name, rc);
 298                 GOTO(out_cleanup, rc);
 299         }
 300
 301         return 0;
 302
 303 out_cleanup:
 304         fld_client_proc_fini(fld);
 305         return rc;
 306 }
 307
 308 void fld_client_proc_fini(struct lu_client_fld *fld)
 309 {
 310         if (fld->lcf_proc_dir) {
 311                 if (!IS_ERR(fld->lcf_proc_dir))
 312                         lprocfs_remove(&fld->lcf_proc_dir);
 313                 fld->lcf_proc_dir = NULL;
 314         }
 315 }
 316 #else
 317 static int fld_client_proc_init(struct lu_client_fld *fld)
 318 {
 319         return 0;
 320 }
 321
 322 void fld_client_proc_fini(struct lu_client_fld *fld)
 323 {
 324         return;
 325 }
 326 #endif
 327 EXPORT_SYMBOL(fld_client_proc_fini);
 328
 329 static inline int hash_is_sane(int hash)
 330 {
 331         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 332 }
 333
 334 int fld_client_init(struct lu_client_fld *fld,
 335                     const char *prefix, int hash)
 336 {
 337         int cache_size, cache_threshold;
 338         int rc;
 339
 340         LASSERT(fld != NULL);
 341
 342         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 343                  "cli-%s", prefix);
 344
 345         if (!hash_is_sane(hash)) {
 346                 CERROR("%s: Wrong hash function %#x\n",
 347                        fld->lcf_name, hash);
 348                 return -EINVAL;
 349         }
 350
 351         fld->lcf_count = 0;
 352         spin_lock_init(&fld->lcf_lock);
 353         fld->lcf_hash = &fld_hash[hash];
 354         fld->lcf_flags = LUSTRE_FLD_INIT;
 355         INIT_LIST_HEAD(&fld->lcf_targets);
 356
 357         cache_size = FLD_CLIENT_CACHE_SIZE /
 358                 sizeof(struct fld_cache_entry);
 359
 360         cache_threshold = cache_size *
 361                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 362
 363         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 364                                         cache_size, cache_threshold);
 365         if (IS_ERR(fld->lcf_cache)) {
 366                 rc = PTR_ERR(fld->lcf_cache);
 367                 fld->lcf_cache = NULL;
 368                 GOTO(out, rc);
 369         }
 370
 371         rc = fld_client_proc_init(fld);
 372         if (rc)
 373                 GOTO(out, rc);
 374 out:
 375         if (rc)
 376                 fld_client_fini(fld);
 377         else
 378                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 379                        fld->lcf_name, fld->lcf_hash->fh_name);
 380         return rc;
 381 }
 382 EXPORT_SYMBOL(fld_client_init);
 383
 384 void fld_client_fini(struct lu_client_fld *fld)
 385 {
 386         struct lu_fld_target *target, *tmp;
 387
 388         spin_lock(&fld->lcf_lock);
 389         list_for_each_entry_safe(target, tmp,
 390                                      &fld->lcf_targets, ft_chain) {
 391                 fld->lcf_count--;
 392                 list_del(&target->ft_chain);
 393                 if (target->ft_exp != NULL)
 394                         class_export_put(target->ft_exp);
 395                 OBD_FREE_PTR(target);
 396         }
 397         spin_unlock(&fld->lcf_lock);
 398
 399         if (fld->lcf_cache != NULL) {
 400                 if (!IS_ERR(fld->lcf_cache))
 401                         fld_cache_fini(fld->lcf_cache);
 402                 fld->lcf_cache = NULL;
 403         }
 404 }
 405 EXPORT_SYMBOL(fld_client_fini);
 406
 407 int fld_client_rpc(struct obd_export *exp,
 408                    struct lu_seq_range *range, __u32 fld_op)
 409 {
 410         struct ptlrpc_request *req;
 411         struct lu_seq_range   *prange;
 412         __u32            *op;
 413         int                 rc;
 414         struct obd_import     *imp;
 415
 416         LASSERT(exp != NULL);
 417
 418         imp = class_exp2cliimp(exp);
 419         req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY, LUSTRE_MDS_VERSION,
 420                                         FLD_QUERY);
 421         if (req == NULL)
 422                 return -ENOMEM;
 423
 424         op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 425         *op = fld_op;
 426
 427         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 428         *prange = *range;
 429
 430         ptlrpc_request_set_replen(req);
 431         req->rq_request_portal = FLD_REQUEST_PORTAL;
 432         ptlrpc_at_set_req_timeout(req);
 433
 434         if (fld_op == FLD_LOOKUP &&
 435             imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS)
 436                 req->rq_allow_replay = 1;
 437
 438         if (fld_op != FLD_LOOKUP)
 439                 mdc_get_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 440         fld_enter_request(&exp->exp_obd->u.cli);
 441         rc = ptlrpc_queue_wait(req);
 442         fld_exit_request(&exp->exp_obd->u.cli);
 443         if (fld_op != FLD_LOOKUP)
 444                 mdc_put_rpc_lock(exp->exp_obd->u.cli.cl_rpc_lock, NULL);
 445         if (rc)
 446                 GOTO(out_req, rc);
 447
 448         prange = req_capsule_server_get(&req->rq_pill, &RMF_FLD_MDFLD);
 449         if (prange == NULL)
 450                 GOTO(out_req, rc = -EFAULT);
 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, seqno_t seq, mdsno_t *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: "LPX64") on target %s (idx "LPU64")\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)