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  *
  31  * lustre/fld/fld_request.c
  32  *
  33  * FLD (Fids Location Database)
  34  *
  35  * Author: Yury Umanets <umka@clusterfs.com>
  36  */
  37
  38 #define DEBUG_SUBSYSTEM S_FLD
  39
  40 #include <libcfs/libcfs.h>
  41 #include <linux/module.h>
  42 #include <linux/math64.h>
  43
  44 #include <obd.h>
  45 #include <obd_class.h>
  46 #include <obd_support.h>
  47 #include <lprocfs_status.h>
  48 #include <lustre_req_layout.h>
  49 #include <lustre_fld.h>
  50 #include <lustre_mdc.h>
  51 #include "fld_internal.h"
  52
  53 static int fld_rrb_hash(struct lu_client_fld *fld, u64 seq)
  54 {
  55         LASSERT(fld->lcf_count > 0);
  56         return do_div(seq, fld->lcf_count);
  57 }
  58
  59 static struct lu_fld_target *
  60 fld_rrb_scan(struct lu_client_fld *fld, u64 seq)
  61 {
  62         struct lu_fld_target *target;
  63         int hash;
  64
  65         ENTRY;
  66
  67         /*
  68          * Because almost all of special sequence located in MDT0,
  69          * it should go to index 0 directly, instead of calculating
  70          * hash again, and also if other MDTs is not being connected,
  71          * the fld lookup requests(for seq on MDT0) should not be
  72          * blocked because of other MDTs
  73          */
  74         if (fid_seq_is_norm(seq))
  75                 hash = fld_rrb_hash(fld, seq);
  76         else
  77                 hash = 0;
  78
  79 again:
  80         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
  81                 if (target->ft_idx == hash)
  82                         RETURN(target);
  83         }
  84
  85         if (hash != 0) {
  86                 /*
  87                  * It is possible the remote target(MDT) are not connected to
  88                  * with client yet, so we will refer this to MDT0, which should
  89                  * be connected during mount
  90                  */
  91                 hash = 0;
  92                 goto again;
  93         }
  94
  95         CERROR("%s: Can't find target by hash %d (seq %#llx). Targets (%d):\n",
  96                fld->lcf_name, hash, seq, fld->lcf_count);
  97
  98         list_for_each_entry(target, &fld->lcf_targets, ft_chain) {
  99                 const char *srv_name = target->ft_srv != NULL  ?
 100                         target->ft_srv->lsf_name : "<null>";
 101                 const char *exp_name = target->ft_exp != NULL ?
 102                         (char *)target->ft_exp->exp_obd->obd_uuid.uuid :
 103                         "<null>";
 104
 105                 CERROR("  exp: 0x%p (%s), srv: 0x%p (%s), idx: %llu\n",
 106                        target->ft_exp, exp_name, target->ft_srv,
 107                        srv_name, target->ft_idx);
 108         }
 109
 110         /*
 111          * If target is not found, there is logical error anyway, so here is
 112          * LBUG() to catch this situation.
 113          */
 114         LBUG();
 115         RETURN(NULL);
 116 }
 117
 118 struct lu_fld_hash fld_hash[] = {
 119         {
 120                 .fh_name = "RRB",
 121                 .fh_hash_func = fld_rrb_hash,
 122                 .fh_scan_func = fld_rrb_scan
 123         },
 124         {
 125                 NULL,
 126         }
 127 };
 128
 129 static struct lu_fld_target *
 130 fld_client_get_target(struct lu_client_fld *fld, u64 seq)
 131 {
 132         struct lu_fld_target *target;
 133
 134         ENTRY;
 135
 136         LASSERT(fld->lcf_hash != NULL);
 137
 138         spin_lock(&fld->lcf_lock);
 139         target = fld->lcf_hash->fh_scan_func(fld, seq);
 140         spin_unlock(&fld->lcf_lock);
 141
 142         if (target) {
 143                 CDEBUG(D_INFO, "%s: Found target (idx %llu) by seq %#llx\n",
 144                        fld->lcf_name, target->ft_idx, seq);
 145         }
 146
 147         RETURN(target);
 148 }
 149
 150 /*
 151  * Add export to FLD. This is usually done by CMM and LMV as they are main users
 152  * of FLD module.
 153  */
 154 int fld_client_add_target(struct lu_client_fld *fld,
 155                           struct lu_fld_target *tar)
 156 {
 157         const char *name;
 158         struct lu_fld_target *target, *tmp;
 159
 160         ENTRY;
 161
 162         LASSERT(tar != NULL);
 163         name = fld_target_name(tar);
 164         LASSERT(name != NULL);
 165         LASSERT(tar->ft_srv != NULL || tar->ft_exp != NULL);
 166
 167         CDEBUG(D_INFO, "%s: Adding target %s (idx %llu)\n", fld->lcf_name,
 168                name, tar->ft_idx);
 169
 170         OBD_ALLOC_PTR(target);
 171         if (!target)
 172                 RETURN(-ENOMEM);
 173
 174         spin_lock(&fld->lcf_lock);
 175         list_for_each_entry(tmp, &fld->lcf_targets, ft_chain) {
 176                 if (tmp->ft_idx == tar->ft_idx) {
 177                         spin_unlock(&fld->lcf_lock);
 178                         OBD_FREE_PTR(target);
 179                         CERROR("Target %s exists in FLD and known as %s:#%llu\n",
 180                                name, fld_target_name(tmp), tmp->ft_idx);
 181                         RETURN(-EEXIST);
 182                 }
 183         }
 184
 185         target->ft_exp = tar->ft_exp;
 186         if (target->ft_exp)
 187                 class_export_get(target->ft_exp);
 188         target->ft_srv = tar->ft_srv;
 189         target->ft_idx = tar->ft_idx;
 190
 191         list_add_tail(&target->ft_chain, &fld->lcf_targets);
 192
 193         fld->lcf_count++;
 194         spin_unlock(&fld->lcf_lock);
 195
 196         RETURN(0);
 197 }
 198 EXPORT_SYMBOL(fld_client_add_target);
 199
 200 /* Remove export from FLD */
 201 int fld_client_del_target(struct lu_client_fld *fld, u64 idx)
 202 {
 203         struct lu_fld_target *target, *tmp;
 204
 205         ENTRY;
 206
 207         spin_lock(&fld->lcf_lock);
 208         list_for_each_entry_safe(target, tmp, &fld->lcf_targets, ft_chain) {
 209                 if (target->ft_idx == idx) {
 210                         fld->lcf_count--;
 211                         list_del(&target->ft_chain);
 212                         spin_unlock(&fld->lcf_lock);
 213
 214                         if (target->ft_exp)
 215                                 class_export_put(target->ft_exp);
 216
 217                         OBD_FREE_PTR(target);
 218                         RETURN(0);
 219                 }
 220         }
 221         spin_unlock(&fld->lcf_lock);
 222         RETURN(-ENOENT);
 223 }
 224
 225 struct dentry *fld_debugfs_dir;
 226
 227 static void fld_client_debugfs_init(struct lu_client_fld *fld)
 228 {
 229         ENTRY;
 230         fld->lcf_debugfs_entry = debugfs_create_dir(fld->lcf_name,
 231                                                    fld_debugfs_dir);
 232         ldebugfs_add_vars(fld->lcf_debugfs_entry,
 233                           fld_client_debugfs_list,
 234                           fld);
 235 }
 236
 237 void fld_client_debugfs_fini(struct lu_client_fld *fld)
 238 {
 239         debugfs_remove_recursive(fld->lcf_debugfs_entry);
 240 }
 241 EXPORT_SYMBOL(fld_client_debugfs_fini);
 242
 243 static inline int hash_is_sane(int hash)
 244 {
 245         return (hash >= 0 && hash < ARRAY_SIZE(fld_hash));
 246 }
 247
 248 int fld_client_init(struct lu_client_fld *fld,
 249                     const char *prefix, int hash)
 250 {
 251         int cache_size, cache_threshold;
 252         int rc = 0;
 253
 254         ENTRY;
 255         snprintf(fld->lcf_name, sizeof(fld->lcf_name),
 256                  "cli-%s", prefix);
 257
 258         if (!hash_is_sane(hash)) {
 259                 CERROR("%s: Wrong hash function %#x\n",
 260                        fld->lcf_name, hash);
 261                 RETURN(-EINVAL);
 262         }
 263
 264         fld->lcf_count = 0;
 265         spin_lock_init(&fld->lcf_lock);
 266         fld->lcf_hash = &fld_hash[hash];
 267         INIT_LIST_HEAD(&fld->lcf_targets);
 268
 269         cache_size = FLD_CLIENT_CACHE_SIZE /
 270                 sizeof(struct fld_cache_entry);
 271
 272         cache_threshold = cache_size *
 273                 FLD_CLIENT_CACHE_THRESHOLD / 100;
 274
 275         fld->lcf_cache = fld_cache_init(fld->lcf_name,
 276                                         cache_size, cache_threshold);
 277         if (IS_ERR(fld->lcf_cache)) {
 278                 rc = PTR_ERR(fld->lcf_cache);
 279                 fld->lcf_cache = NULL;
 280                 GOTO(out, rc);
 281         }
 282
 283         fld_client_debugfs_init(fld);
 284         EXIT;
 285 out:
 286         if (rc)
 287                 fld_client_fini(fld);
 288         else
 289                 CDEBUG(D_INFO, "%s: Using \"%s\" hash\n",
 290                        fld->lcf_name, fld->lcf_hash->fh_name);
 291         return rc;
 292 }
 293 EXPORT_SYMBOL(fld_client_init);
 294
 295 void fld_client_fini(struct lu_client_fld *fld)
 296 {
 297         struct lu_fld_target *target, *tmp;
 298
 299         ENTRY;
 300
 301         spin_lock(&fld->lcf_lock);
 302         list_for_each_entry_safe(target, tmp, &fld->lcf_targets, ft_chain) {
 303                 fld->lcf_count--;
 304                 list_del(&target->ft_chain);
 305                 if (target->ft_exp)
 306                         class_export_put(target->ft_exp);
 307                 OBD_FREE_PTR(target);
 308         }
 309         spin_unlock(&fld->lcf_lock);
 310
 311         if (fld->lcf_cache) {
 312                 if (!IS_ERR(fld->lcf_cache))
 313                         fld_cache_fini(fld->lcf_cache);
 314                 fld->lcf_cache = NULL;
 315         }
 316
 317         EXIT;
 318 }
 319 EXPORT_SYMBOL(fld_client_fini);
 320
 321 int fld_client_rpc(struct obd_export *exp,
 322                    struct lu_seq_range *range, u32 fld_op,
 323                    struct ptlrpc_request **reqp)
 324 {
 325         struct ptlrpc_request *req = NULL;
 326         struct lu_seq_range *prange;
 327         u32 *op;
 328         int rc = 0;
 329         struct obd_import *imp;
 330
 331         ENTRY;
 332
 333         LASSERT(exp != NULL);
 334
 335         imp = class_exp2cliimp(exp);
 336         switch (fld_op) {
 337         case FLD_QUERY:
 338                 req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_QUERY,
 339                                                 LUSTRE_MDS_VERSION, FLD_QUERY);
 340                 if (!req)
 341                         RETURN(-ENOMEM);
 342
 343                 /*
 344                  * XXX: only needed when talking to old server(< 2.6), it should
 345                  * be removed when < 2.6 server is not supported
 346                  */
 347                 op = req_capsule_client_get(&req->rq_pill, &RMF_FLD_OPC);
 348                 *op = FLD_LOOKUP;
 349
 350                 /*
 351                  * For MDS_MDS seq lookup, it will always use LWP connection,
 352                  * but LWP will be evicted after restart, so cause the error.
 353                  * so we will set no_delay for seq lookup request, once the
 354                  * request fails because of the eviction. always retry here
 355                  */
 356                 if (imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS) {
 357                         req->rq_allow_replay = 1;
 358                         req->rq_no_delay = 1;
 359                 }
 360                 break;
 361         case FLD_READ:
 362                 req = ptlrpc_request_alloc_pack(imp, &RQF_FLD_READ,
 363                                                 LUSTRE_MDS_VERSION, FLD_READ);
 364                 if (!req)
 365                         RETURN(-ENOMEM);
 366
 367                 req_capsule_set_size(&req->rq_pill, &RMF_GENERIC_DATA,
 368                                      RCL_SERVER, PAGE_SIZE);
 369                 break;
 370         default:
 371                 rc = -EINVAL;
 372                 break;
 373         }
 374
 375         if (rc != 0)
 376                 RETURN(rc);
 377
 378         prange = req_capsule_client_get(&req->rq_pill, &RMF_FLD_MDFLD);
 379         *prange = *range;
 380         ptlrpc_request_set_replen(req);
 381         req->rq_request_portal = FLD_REQUEST_PORTAL;
 382         req->rq_reply_portal = MDC_REPLY_PORTAL;
 383         ptlrpc_at_set_req_timeout(req);
 384
 385         if (OBD_FAIL_CHECK(OBD_FAIL_FLD_QUERY_REQ && req->rq_no_delay)) {
 386                 /* the same error returned by ptlrpc_import_delay_req */
 387                 rc = -EAGAIN;
 388                 req->rq_status = rc;
 389         } else {
 390                 obd_get_request_slot(&exp->exp_obd->u.cli);
 391                 rc = ptlrpc_queue_wait(req);
 392                 obd_put_request_slot(&exp->exp_obd->u.cli);
 393         }
 394
 395         if (rc == -ENOENT) {
 396                 /* Don't loop forever on non-existing FID sequences. */
 397                 GOTO(out_req, rc);
 398         }
 399
 400         if (rc != 0) {
 401                 if (imp->imp_state != LUSTRE_IMP_CLOSED &&
 402                     !imp->imp_deactive &&
 403                     imp->imp_connect_flags_orig & OBD_CONNECT_MDS_MDS &&
 404                     OCD_HAS_FLAG(&imp->imp_connect_data, LIGHTWEIGHT) &&
 405                     rc != -ENOTSUPP) {
 406                         /*
 407                          * Since LWP is not replayable, so notify the caller
 408                          * to retry if needed after a while.
 409                          */
 410                         rc = -EAGAIN;
 411                 }
 412                 GOTO(out_req, rc);
 413         }
 414
 415         if (fld_op == FLD_QUERY) {
 416                 prange = req_capsule_server_get(&req->rq_pill,
 417                                                 &RMF_FLD_MDFLD);
 418                 if (!prange)
 419                         GOTO(out_req, rc = -EFAULT);
 420                 *range = *prange;
 421         }
 422
 423         EXIT;
 424 out_req:
 425         if (rc != 0 || !reqp) {
 426                 ptlrpc_req_finished(req);
 427                 req = NULL;
 428         }
 429
 430         if (reqp)
 431                 *reqp = req;
 432
 433         return rc;
 434 }
 435
 436 int fld_client_lookup(struct lu_client_fld *fld, u64 seq, u32 *mds,
 437                       u32 flags, const struct lu_env *env)
 438 {
 439         struct lu_seq_range res = { 0 };
 440         struct lu_fld_target *target;
 441         struct lu_fld_target *origin;
 442         int rc;
 443
 444         ENTRY;
 445
 446         rc = fld_cache_lookup(fld->lcf_cache, seq, &res);
 447         if (rc == 0) {
 448                 *mds = res.lsr_index;
 449                 RETURN(0);
 450         }
 451
 452         /* Can not find it in the cache */
 453         target = fld_client_get_target(fld, seq);
 454         LASSERT(target != NULL);
 455         origin = target;
 456 again:
 457         CDEBUG(D_INFO, "%s: Lookup fld entry (seq: %#llx) on target %s (idx %llu)\n",
 458                fld->lcf_name, seq, fld_target_name(target), target->ft_idx);
 459
 460         res.lsr_start = seq;
 461         fld_range_set_type(&res, flags);
 462
 463 #ifdef HAVE_SERVER_SUPPORT
 464         if (target->ft_srv) {
 465                 LASSERT(env != NULL);
 466                 rc = fld_server_lookup(env, target->ft_srv, seq, &res);
 467         } else
 468 #endif /* HAVE_SERVER_SUPPORT */
 469         {
 470                 rc = fld_client_rpc(target->ft_exp, &res, FLD_QUERY, NULL);
 471         }
 472
 473         if (rc == -ESHUTDOWN) {
 474                 /*
 475                  * If fld lookup failed because the target has been shutdown,
 476                  * then try next target in the list, until trying all targets
 477                  * or fld lookup succeeds
 478                  */
 479                 spin_lock(&fld->lcf_lock);
 480                 /*
 481                  * If the next entry in the list is the head of the list,
 482                  * move to the next entry after the head and retrieve
 483                  * the target. Else retreive the next target entry.
 484                  */
 485                 if (target->ft_chain.next == &fld->lcf_targets)
 486                         target = list_entry(target->ft_chain.next->next,
 487                                             struct lu_fld_target, ft_chain);
 488                 else
 489                         target = list_entry(target->ft_chain.next,
 490                                                  struct lu_fld_target,
 491                                                  ft_chain);
 492                 spin_unlock(&fld->lcf_lock);
 493                 if (target != origin)
 494                         goto again;
 495         }
 496         if (rc == 0) {
 497                 *mds = res.lsr_index;
 498                 fld_cache_insert(fld->lcf_cache, &res);
 499         }
 500
 501         RETURN(rc);
 502 }
 503 EXPORT_SYMBOL(fld_client_lookup);
 504
 505 void fld_client_flush(struct lu_client_fld *fld)
 506 {
 507         fld_cache_flush(fld->lcf_cache);
 508 }
 509
 510 static int __init fld_init(void)
 511 {
 512 #ifdef HAVE_SERVER_SUPPORT
 513         int rc;
 514
 515         rc = fld_server_mod_init();
 516         if (rc)
 517                 return rc;
 518 #endif /* HAVE_SERVER_SUPPORT */
 519
 520         fld_debugfs_dir = debugfs_create_dir(LUSTRE_FLD_NAME,
 521                                              debugfs_lustre_root);
 522         return PTR_ERR_OR_ZERO(fld_debugfs_dir);
 523 }
 524
 525 static void __exit fld_exit(void)
 526 {
 527 #ifdef HAVE_SERVER_SUPPORT
 528         fld_server_mod_exit();
 529 #endif /* HAVE_SERVER_SUPPORT */
 530
 531         debugfs_remove_recursive(fld_debugfs_dir);
 532 }
 533
 534 MODULE_AUTHOR("OpenSFS, Inc. <http://www.lustre.org/>");
 535 MODULE_DESCRIPTION("Lustre FID Location Database");
 536 MODULE_VERSION(LUSTRE_VERSION_STRING);
 537 MODULE_LICENSE("GPL");
 538
 539 module_init(fld_init);
 540 module_exit(fld_exit);