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.gnu.org/licenses/gpl-2.0.html
  19  *
  20  * GPL HEADER END
  21  */
  22 /*
  23  * Copyright (c) 2007, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2017, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * lustre/fld/fld_request.c
  33  *
  34  * FLD (Fids Location Database)
  35  *
  36  * Author: Yury Umanets <umka@clusterfs.com>
  37  */
  38
  39 #define DEBUG_SUBSYSTEM S_FLD
  40
  41 #include <libcfs/libcfs.h>
  42 #include <linux/module.h>
  43 #include <linux/math64.h>
  44
  45 #include <obd.h>
  46 #include <obd_class.h>
  47 #include <obd_support.h>
  48 #include <lprocfs_status.h>
  49 #include <lustre_req_layout.h>
  50 #include <lustre_fld.h>
  51 #include <lustre_mdc.h>
  52 #include "fld_internal.h"
  53
  54 static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
  55 {
  56         LASSERT(fld->lcf_count > 0);
  57         return do_div(seq, fld->lcf_count);
  58 }
  59
  60 static struct lu_fld_target *
  61 fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
  62 {
  63         struct lu_fld_target *target;
  64         int hash;
  65
  66         ENTRY;
  67
  68         /*
  69          * Because almost all of special sequence located in MDT0,
  70          * it should go to index 0 directly, instead of calculating
  71          * hash again, and also if other MDTs is not being connected,
  72          * the fld lookup requests(for seq on MDT0) should not be
  73          * blocked because of other MDTs
  74          */
  75         if (fid_seq_is_norm(seq))
  76                 hash = fld_rrb_hash(fld, seq);
  77         else
  78                 hash = 0;
  79
  80 again:
  81         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
  82                 if (target->ft_idx == hash)
  83                         RETURN(target);
  84         }
  85
  86         if (hash != 0) {
  87                 /*
  88                  * It is possible the remote target(MDT) are not connected to
  89                  * with client yet, so we will refer this to MDT0, which should
  90                  * be connected during mount
  91                  */
  92                 hash = 0;
  93                 goto again;
  94         }
  95
  96         CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
  97                fld->lcf_name, hash, seq, fld->lcf_count);
  98
  99         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
 100                 const char *srv_name = target->ft_srv != NULL  ?
 101                         target->ft_srv->lsf_name : "<null>";
 102                 const char *exp_name = target->ft_exp != NULL ?
 103                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 104                         "<null>";
 105
 106                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
 107                        target->ft_exp, exp_name, target->ft_srv,
 108                        srv_name, target->ft_idx);
 109         }
 110
 111         /*
 112          * If target is not found, there is logical error anyway, so here is
 113          * LBUG() to catch this situation.
 114          */
 115         LBUG();
 116         RETURN(NULL);
 117 }
 118
 119 struct lu_fld_hash fld_hash[] = {
 120         {
 121                 .fh_name = "RRB",
 122                 .fh_hash_func = fld_rrb_hash,
 123                 .fh_scan_func = fld_rrb_scan
 124         },
 125         {
 126                 NULL,
 127         }
 128 };
 129
 130 static struct lu_fld_target *
 131 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
 132 {
 133         struct lu_fld_target *target;
 134
 135         ENTRY;
 136
 137         LASSERT(fld->lcf_hash != NULL);
 138
 139         spin_lock(&fld->lcf_lock);
 140         target = fld->lcf_hash->fh_scan_func(fld, seq);
 141         spin_unlock(&fld->lcf_lock);
 142
 143         if (target) {
 144                 CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
 145                        fld->lcf_name, target->ft_idx, seq);
 146         }
 147
 148         RETURN(target);
 149 }
 150
 151 /*
 152  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 153  * of FLD module.
 154  */
 155 int fld_client_add_target(struct lu_client_fld *fld,
 156                           struct lu_fld_target *tar)
 157 {
 158         const char *name;
 159         struct lu_fld_target *target, *tmp;
 160
 161         ENTRY;
 162
 163         LASSERT(tar != NULL);
 164         name = fld_target_name(tar);
 165         LASSERT(name != NULL);
 166         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 167
 168         CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n", fld->lcf_name,
 169                name, tar->ft_idx);
 170
 171         OBD_ALLOC_PTR(target);
 172         if (!target)
 173                 RETURN(-ENOMEM);
 174
 175         spin_lock(&fld->lcf_lock);
 176         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 177                 if (tmp->ft_idx == tar->ft_idx) {
 178                         spin_unlock(&fld->lcf_lock);
 179                         OBD_FREE_PTR(target);
 180                         CERROR("Target %s exists in FLD and known as %s:#%llu\n",
 181                                name, fld_target_name(tmp), tmp->ft_idx);
 182                         RETURN(-EEXIST);
 183                 }
 184         }
 185
 186         target->ft_exp = tar->ft_exp;
 187         if (target->ft_exp)
 188                 class_export_get(target->ft_exp);
 189         target->ft_srv = tar->ft_srv;
 190         target->ft_idx = tar->ft_idx;
 191
 192         list_add_tail(&target->ft_chain, &fld->lcf_targets);
 193
 194         fld->lcf_count++;
 195         spin_unlock(&fld->lcf_lock);
 196
 197         RETURN(0);
 198 }
 199 EXPORT_SYMBOL(fld_client_add_target);
 200
 201 /* Remove export from FLD */
 202 int fld_client_del_target(struct lu_client_fld *fld, u64 idx)
 203 {
 204         struct lu_fld_target *target, *tmp;
 205
 206         ENTRY;
 207
 208         spin_lock(&fld->lcf_lock);
 209         list_for_each_entry_safe(target, tmp, &fld->lcf_targets, ft_chain) {
 210                 if (target->ft_idx == idx) {
 211                         fld->lcf_count--;
 212                         list_del(&target->ft_chain);
 213                         spin_unlock(&fld->lcf_lock);
 214
 215                         if (target->ft_exp)
 216                                 class_export_put(target->ft_exp);
 217
 218                         OBD_FREE_PTR(target);
 219                         RETURN(0);
 220                 }
 221         }
 222         spin_unlock(&fld->lcf_lock);
 223         RETURN(-ENOENT);
 224 }
 225
 226 struct dentry *fld_debugfs_dir;
 227
 228 static int fld_client_debugfs_init(struct lu_client_fld *fld)
 229 {
 230         int rc;
 231
 232         ENTRY;
 233         fld->lcf_debugfs_entry = ldebugfs_register(fld->lcf_name,
 234                                                    fld_debugfs_dir,
 235                                                    fld_client_debugfs_list,
 236                                                    fld);
 237         if (IS_ERR_OR_NULL(fld->lcf_debugfs_entry)) {
 238                 CERROR("%s: LdebugFS failed in fld-init\n", fld->lcf_name);
 239                 rc = fld->lcf_debugfs_entry ? PTR_ERR(fld->lcf_debugfs_entry)
 240                                             : -ENOMEM;
 241                 fld->lcf_debugfs_entry = NULL;
 242                 RETURN(rc);
 243         }
 244
 245         return 0;
 246 }
 247
 248 void fld_client_debugfs_fini(struct lu_client_fld *fld)
 249 {
 250         debugfs_remove_recursive(fld->lcf_debugfs_entry);
 251 }
 252 EXPORT_SYMBOL(fld_client_debugfs_fini);
 253
 254 static inline int hash_is_sane(int hash)
 255 {
 256         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 257 }
 258
 259 int fld_client_init(struct lu_client_fld *fld,
 260                     const char *prefix, int hash)
 261 {
 262         int cache_size, cache_threshold;
 263         int rc;
 264
 265         ENTRY;
 266         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 267                  "cli-%s", prefix);
 268
 269         if (!hash_is_sane(hash)) {
 270                 CERROR("%s: Wrong hash function %#x\n",
 271                        fld->lcf_name, hash);
 272                 RETURN(-EINVAL);
 273         }
 274
 275         fld->lcf_count = 0;
 276         spin_lock_init(&fld->lcf_lock);
 277         fld->lcf_hash = &fld_hash[hash];
 278         INIT_LIST_HEAD(&fld->lcf_targets);
 279
 280         cache_size = FLD_CLIENT_CACHE_SIZE /
 281                 sizeof(struct fld_cache_entry);
 282
 283         cache_threshold = cache_size *
 284                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 285
 286         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 287                                         cache_size, cache_threshold);
 288         if (IS_ERR(fld->lcf_cache)) {
 289                 rc = PTR_ERR(fld->lcf_cache);
 290                 fld->lcf_cache = NULL;
 291                 GOTO(out, rc);
 292         }
 293
 294         rc = fld_client_debugfs_init(fld);
 295         if (rc)
 296                 GOTO(out, rc);
 297         EXIT;
 298 out:
 299         if (rc)
 300                 fld_client_fini(fld);
 301         else
 302                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 303                        fld->lcf_name, fld->lcf_hash->fh_name);
 304         return rc;
 305 }
 306 EXPORT_SYMBOL(fld_client_init);
 307
 308 void fld_client_fini(struct lu_client_fld *fld)
 309 {
 310         struct lu_fld_target *target, *tmp;
 311
 312         ENTRY;
 313
 314         spin_lock(&fld->lcf_lock);
 315         list_for_each_entry_safe(target, tmp, &fld->lcf_targets, ft_chain) {
 316                 fld->lcf_count--;
 317                 list_del(&target->ft_chain);
 318                 if (target->ft_exp)
 319                         class_export_put(target->ft_exp);
 320                 OBD_FREE_PTR(target);
 321         }
 322         spin_unlock(&fld->lcf_lock);
 323
 324         if (fld->lcf_cache) {
 325                 if (!IS_ERR(fld->lcf_cache))
 326                         fld_cache_fini(fld->lcf_cache);
 327                 fld->lcf_cache = NULL;
 328         }
 329
 330         EXIT;
 331 }
 332 EXPORT_SYMBOL(fld_client_fini);
 333
 334 int fld_client_rpc(struct obd_export *exp,
 335                    struct lu_seq_range *range, u32 fld_op,
 336                    struct ptlrpc_request **reqp)
 337 {
 338         struct ptlrpc_request *req = NULL;
 339         struct lu_seq_range *prange;
 340         u32 *op;
 341         int rc = 0;
 342         struct obd_import *imp;
 343
 344         ENTRY;
 345
 346         LASSERT(exp != NULL);
 347
 348         imp = class_exp2cliimp(exp);
 349         switch (fld_op) {
 350         case FLD_QUERY:
 351                 req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY,
 352                                                 LUSTRE_MDS_VERSION, FLD_QUERY);
 353                 if (!req)
 354                         RETURN(-ENOMEM);
 355
 356                 /*
 357                  * XXX: only needed when talking to old server(< 2.6), it should
 358                  * be removed when < 2.6 server is not supported
 359                  */
 360                 op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 361                 *op = FLD_LOOKUP;
 362
 363                 /*
 364                  * For MDS_MDS seq lookup, it will always use LWP connection,
 365                  * but LWP will be evicted after restart, so cause the error.
 366                  * so we will set no_delay for seq lookup request, once the
 367                  * request fails because of the eviction. always retry here
 368                  */
 369                 if (imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS) {
 370                         req->rq_allow_replay = 1;
 371                         req->rq_no_delay = 1;
 372                 }
 373                 break;
 374         case FLD_READ:
 375                 req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_READ,
 376                                                 LUSTRE_MDS_VERSION, FLD_READ);
 377                 if (!req)
 378                         RETURN(-ENOMEM);
 379
 380                 req_capsule_set_size(&req->rq_pill, &RMF_GENERIC_DATA,
 381                                      RCL_SERVER, PAGE_SIZE);
 382                 break;
 383         default:
 384                 rc = -EINVAL;
 385                 break;
 386         }
 387
 388         if (rc != 0)
 389                 RETURN(rc);
 390
 391         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 392         *prange = *range;
 393         ptlrpc_request_set_replen(req);
 394         req->rq_request_portal = FLD_REQUEST_PORTAL;
 395         req->rq_reply_portal = MDC_REPLY_PORTAL;
 396         ptlrpc_at_set_req_timeout(req);
 397
 398         if (OBD_FAIL_CHECK(OBD_FAIL_FLD_QUERY_REQ && req->rq_no_delay)) {
 399                 /* the same error returned by ptlrpc_import_delay_req */
 400                 rc = -EWOULDBLOCK;
 401                 req->rq_status = rc;
 402         } else {
 403                 obd_get_request_slot(&exp->exp_obd->u.cli);
 404                 rc = ptlrpc_queue_wait(req);
 405                 obd_put_request_slot(&exp->exp_obd->u.cli);
 406         }
 407
 408         if (rc == -ENOENT) {
 409                 /* Don't loop forever on non-existing FID sequences. */
 410                 GOTO(out_req, rc);
 411         }
 412
 413         if (rc != 0) {
 414                 if (imp->imp_state != LUSTRE_IMP_CLOSED &&
 415                     !imp->imp_deactive &&
 416                     imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS &&
 417                     OCD_HAS_FLAG(&imp->imp_connect_data, LIGHTWEIGHT) &&
 418                     rc != -ENOTSUPP) {
 419                         /*
 420                          * Since LWP is not replayable, so notify the caller
 421                          * to retry if needed after a while.
 422                          */
 423                         rc = -EAGAIN;
 424                 }
 425                 GOTO(out_req, rc);
 426         }
 427
 428         if (fld_op == FLD_QUERY) {
 429                 prange = req_capsule_server_get(&req->rq_pill,
 430                                                 &RMF_FLD_MDFLD);
 431                 if (!prange)
 432                         GOTO(out_req, rc = -EFAULT);
 433                 *range = *prange;
 434         }
 435
 436         EXIT;
 437 out_req:
 438         if (rc != 0 || !reqp) {
 439                 ptlrpc_req_finished(req);
 440                 req = NULL;
 441         }
 442
 443         if (reqp)
 444                 *reqp = req;
 445
 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         struct lu_fld_target *origin;
 455         int rc;
 456
 457         ENTRY;
 458
 459         rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
 460         if (rc == 0) {
 461                 *mds = res.lsr_index;
 462                 RETURN(0);
 463         }
 464
 465         /* Can not find it in the cache */
 466         target = fld_client_get_target(fld, seq);
 467         LASSERT(target != NULL);
 468         origin = target;
 469 again:
 470         CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
 471                fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
 472
 473         res.lsr_start = seq;
 474         fld_range_set_type(&res, flags);
 475
 476 #ifdef HAVE_SERVER_SUPPORT
 477         if (target->ft_srv) {
 478                 LASSERT(env != NULL);
 479                 rc = fld_server_lookup(env, target->ft_srv, seq, &res);
 480         } else
 481 #endif /* HAVE_SERVER_SUPPORT */
 482         {
 483                 rc = fld_client_rpc(target->ft_exp, &res, FLD_QUERY, NULL);
 484         }
 485
 486         if (rc == -ESHUTDOWN) {
 487                 /*
 488                  * If fld lookup failed because the target has been shutdown,
 489                  * then try next target in the list, until trying all targets
 490                  * or fld lookup succeeds
 491                  */
 492                 spin_lock(&fld->lcf_lock);
 493                 /*
 494                  * If the next entry in the list is the head of the list,
 495                  * move to the next entry after the head and retrieve
 496                  * the target. Else retreive the next target entry.
 497                  */
 498                 if (target->ft_chain.next == &fld->lcf_targets)
 499                         target = list_entry(target->ft_chain.next->next,
 500                                             struct lu_fld_target, ft_chain);
 501                 else
 502                         target = list_entry(target->ft_chain.next,
 503                                                  struct lu_fld_target,
 504                                                  ft_chain);
 505                 spin_unlock(&fld->lcf_lock);
 506                 if (target != origin)
 507                         goto again;
 508         }
 509         if (rc == 0) {
 510                 *mds = res.lsr_index;
 511                 fld_cache_insert(fld->lcf_cache, &res);
 512         }
 513
 514         RETURN(rc);
 515 }
 516 EXPORT_SYMBOL(fld_client_lookup);
 517
 518 void fld_client_flush(struct lu_client_fld *fld)
 519 {
 520         fld_cache_flush(fld->lcf_cache);
 521 }
 522
 523 static int __init fld_init(void)
 524 {
 525         struct dentry *de;
 526 #ifdef HAVE_SERVER_SUPPORT
 527         int rc;
 528
 529         rc = fld_server_mod_init();
 530         if (rc)
 531                 return rc;
 532 #endif /* HAVE_SERVER_SUPPORT */
 533
 534         de = ldebugfs_register(LUSTRE_FLD_NAME,
 535                                debugfs_lustre_root,
 536                                NULL, NULL);
 537         if (!IS_ERR(de))
 538                 fld_debugfs_dir = de;
 539         return PTR_ERR_OR_ZERO(de);
 540 }
 541
 542 static void __exit fld_exit(void)
 543 {
 544 #ifdef HAVE_SERVER_SUPPORT
 545         fld_server_mod_exit();
 546 #endif /* HAVE_SERVER_SUPPORT */
 547
 548         debugfs_remove_recursive(fld_debugfs_dir);
 549 }
 550
 551 MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
 552 MODULE_DESCRIPTION("Lustre FID Location Database");
 553 MODULE_VERSION(LUSTRE_VERSION_STRING);
 554 MODULE_LICENSE("GPL");
 555
 556 module_init(fld_init);
 557 module_exit(fld_exit);