lustre/target/tgt_lastrcvd.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) 2009, 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 Unified Target
  32  * These are common function to work with last_received file
  33  *
  34  * Author: Mikhail Pershin <mike.pershin@intel.com>
  35  */
  36 #include <obd.h>
  37 #include <obd_class.h>
  38 #include <lustre_fid.h>
  39
  40 #include "tgt_internal.h"
  41
  42 /** version recovery epoch */
  43 #define LR_EPOCH_BITS   32
  44
  45 /* Allocate a bitmap for a chunk of reply data slots */
  46 static int tgt_bitmap_chunk_alloc(struct lu_target *lut, int chunk)
  47 {
  48         unsigned long *bm;
  49
  50         OBD_ALLOC_LARGE(bm, BITS_TO_LONGS(LUT_REPLY_SLOTS_PER_CHUNK) *
  51                         sizeof(long));
  52         if (bm == NULL)
  53                 return -ENOMEM;
  54
  55         spin_lock(&lut->lut_client_bitmap_lock);
  56
  57         if (lut->lut_reply_bitmap[chunk] != NULL) {
  58                 /* someone else already allocated the bitmap for this chunk */
  59                 spin_unlock(&lut->lut_client_bitmap_lock);
  60                 OBD_FREE_LARGE(bm, BITS_TO_LONGS(LUT_REPLY_SLOTS_PER_CHUNK) *
  61                          sizeof(long));
  62                 return 0;
  63         }
  64
  65         lut->lut_reply_bitmap[chunk] = bm;
  66
  67         spin_unlock(&lut->lut_client_bitmap_lock);
  68
  69         return 0;
  70 }
  71
  72 /* Look for an available reply data slot in the bitmap
  73  * of the target @lut
  74  * Allocate bitmap chunk when first used
  75  * XXX algo could be improved if this routine limits performance
  76  */
  77 static int tgt_find_free_reply_slot(struct lu_target *lut)
  78 {
  79         unsigned long *bmp;
  80         int chunk = 0;
  81         int rc;
  82         int b;
  83
  84         for (chunk = 0; chunk < LUT_REPLY_SLOTS_MAX_CHUNKS; chunk++) {
  85                 /* allocate the bitmap chunk if necessary */
  86                 if (unlikely(lut->lut_reply_bitmap[chunk] == NULL)) {
  87                         rc = tgt_bitmap_chunk_alloc(lut, chunk);
  88                         if (rc != 0)
  89                                 return rc;
  90                 }
  91                 bmp = lut->lut_reply_bitmap[chunk];
  92
  93                 /* look for an available slot in this chunk */
  94                 do {
  95                         b = find_first_zero_bit(bmp, LUT_REPLY_SLOTS_PER_CHUNK);
  96                         if (b >= LUT_REPLY_SLOTS_PER_CHUNK)
  97                                 break;
  98
  99                         /* found one */
 100                         if (test_and_set_bit(b, bmp) == 0)
 101                                 return chunk * LUT_REPLY_SLOTS_PER_CHUNK + b;
 102                 } while (true);
 103         }
 104
 105         return -ENOSPC;
 106 }
 107
 108 /* Mark the reply data slot @idx 'used' in the corresponding bitmap chunk
 109  * of the target @lut
 110  * Allocate the bitmap chunk if necessary
 111  */
 112 static int tgt_set_reply_slot(struct lu_target *lut, int idx)
 113 {
 114         int chunk;
 115         int b;
 116         int rc;
 117
 118         chunk = idx / LUT_REPLY_SLOTS_PER_CHUNK;
 119         b = idx % LUT_REPLY_SLOTS_PER_CHUNK;
 120
 121         LASSERT(chunk < LUT_REPLY_SLOTS_MAX_CHUNKS);
 122         LASSERT(b < LUT_REPLY_SLOTS_PER_CHUNK);
 123
 124         /* allocate the bitmap chunk if necessary */
 125         if (unlikely(lut->lut_reply_bitmap[chunk] == NULL)) {
 126                 rc = tgt_bitmap_chunk_alloc(lut, chunk);
 127                 if (rc != 0)
 128                         return rc;
 129         }
 130
 131         /* mark the slot 'used' in this chunk */
 132         if (test_and_set_bit(b, lut->lut_reply_bitmap[chunk]) != 0) {
 133                 CERROR("%s: slot %d already set in bitmap\n",
 134                        tgt_name(lut), idx);
 135                 return -EALREADY;
 136         }
 137
 138         return 0;
 139 }
 140
 141
 142 /* Mark the reply data slot @idx 'unused' in the corresponding bitmap chunk
 143  * of the target @lut
 144  */
 145 static int tgt_clear_reply_slot(struct lu_target *lut, int idx)
 146 {
 147         int chunk;
 148         int b;
 149
 150         if (lut->lut_obd->obd_stopping)
 151                 /*
 152                  * in case of failover keep the bit set in order to
 153                  * avoid overwriting slots in reply_data which might
 154                  * be required by resent rpcs
 155                  */
 156                 return 0;
 157         chunk = idx / LUT_REPLY_SLOTS_PER_CHUNK;
 158         b = idx % LUT_REPLY_SLOTS_PER_CHUNK;
 159
 160         LASSERT(chunk < LUT_REPLY_SLOTS_MAX_CHUNKS);
 161         LASSERT(b < LUT_REPLY_SLOTS_PER_CHUNK);
 162
 163         if (lut->lut_reply_bitmap[chunk] == NULL) {
 164                 CERROR("%s: slot %d not allocated\n",
 165                        tgt_name(lut), idx);
 166                 return -ENOENT;
 167         }
 168
 169         if (test_and_clear_bit(b, lut->lut_reply_bitmap[chunk]) == 0) {
 170                 CERROR("%s: slot %d already clear in bitmap\n",
 171                        tgt_name(lut), idx);
 172                 return -EALREADY;
 173         }
 174
 175         return 0;
 176 }
 177
 178
 179 /* Read header of reply_data file of target @tgt into structure @lrh */
 180 static int tgt_reply_header_read(const struct lu_env *env,
 181                                  struct lu_target *tgt,
 182                                  struct lsd_reply_header *lrh)
 183 {
 184         int                      rc;
 185         struct lsd_reply_header  buf;
 186         struct tgt_thread_info  *tti = tgt_th_info(env);
 187
 188         tti->tti_off = 0;
 189         tti->tti_buf.lb_buf = &buf;
 190         tti->tti_buf.lb_len = sizeof(buf);
 191
 192         rc = dt_record_read(env, tgt->lut_reply_data, &tti->tti_buf,
 193                             &tti->tti_off);
 194         if (rc != 0)
 195                 return rc;
 196
 197         lrh->lrh_magic = le32_to_cpu(buf.lrh_magic);
 198         lrh->lrh_header_size = le32_to_cpu(buf.lrh_header_size);
 199         lrh->lrh_reply_size = le32_to_cpu(buf.lrh_reply_size);
 200
 201         CDEBUG(D_HA, "%s: read %s header. magic=0x%08x "
 202                "header_size=%d reply_size=%d\n",
 203                 tgt->lut_obd->obd_name, REPLY_DATA,
 204                 lrh->lrh_magic, lrh->lrh_header_size, lrh->lrh_reply_size);
 205
 206         return 0;
 207 }
 208
 209 /* Write header into replay_data file of target @tgt from structure @lrh */
 210 static int tgt_reply_header_write(const struct lu_env *env,
 211                                   struct lu_target *tgt,
 212                                   struct lsd_reply_header *lrh)
 213 {
 214         int                      rc;
 215         struct lsd_reply_header  buf;
 216         struct tgt_thread_info  *tti = tgt_th_info(env);
 217         struct thandle          *th;
 218         struct dt_object        *dto;
 219
 220         CDEBUG(D_HA, "%s: write %s header. magic=0x%08x "
 221                "header_size=%d reply_size=%d\n",
 222                 tgt->lut_obd->obd_name, REPLY_DATA,
 223                 lrh->lrh_magic, lrh->lrh_header_size, lrh->lrh_reply_size);
 224
 225         if (tgt->lut_bottom->dd_rdonly)
 226                 RETURN(0);
 227
 228         buf.lrh_magic = cpu_to_le32(lrh->lrh_magic);
 229         buf.lrh_header_size = cpu_to_le32(lrh->lrh_header_size);
 230         buf.lrh_reply_size = cpu_to_le32(lrh->lrh_reply_size);
 231
 232         th = dt_trans_create(env, tgt->lut_bottom);
 233         if (IS_ERR(th))
 234                 return PTR_ERR(th);
 235         th->th_sync = 1;
 236
 237         tti->tti_off = 0;
 238         tti->tti_buf.lb_buf = &buf;
 239         tti->tti_buf.lb_len = sizeof(buf);
 240
 241         rc = dt_declare_record_write(env, tgt->lut_reply_data,
 242                                      &tti->tti_buf, tti->tti_off, th);
 243         if (rc)
 244                 GOTO(out, rc);
 245
 246         rc = dt_trans_start(env, tgt->lut_bottom, th);
 247         if (rc)
 248                 GOTO(out, rc);
 249
 250         dto = dt_object_locate(tgt->lut_reply_data, th->th_dev);
 251         rc = dt_record_write(env, dto, &tti->tti_buf, &tti->tti_off, th);
 252 out:
 253         dt_trans_stop(env, tgt->lut_bottom, th);
 254         return rc;
 255 }
 256
 257 /* Write the reply data @lrd into reply_data file of target @tgt
 258  * at offset @off
 259  */
 260 static int tgt_reply_data_write(const struct lu_env *env, struct lu_target *tgt,
 261                                 struct lsd_reply_data *lrd, loff_t off,
 262                                 struct thandle *th)
 263 {
 264         struct tgt_thread_info  *tti = tgt_th_info(env);
 265         struct dt_object        *dto;
 266         struct lsd_reply_data   *buf = &tti->tti_lrd;
 267
 268         lrd->lrd_result = ptlrpc_status_hton(lrd->lrd_result);
 269
 270         buf->lrd_transno         = cpu_to_le64(lrd->lrd_transno);
 271         buf->lrd_xid             = cpu_to_le64(lrd->lrd_xid);
 272         buf->lrd_data            = cpu_to_le64(lrd->lrd_data);
 273         buf->lrd_result          = cpu_to_le32(lrd->lrd_result);
 274         buf->lrd_client_gen      = cpu_to_le32(lrd->lrd_client_gen);
 275
 276         lrd->lrd_result = ptlrpc_status_ntoh(lrd->lrd_result);
 277
 278         tti->tti_off = off;
 279         tti->tti_buf.lb_buf = buf;
 280         tti->tti_buf.lb_len = sizeof(*buf);
 281
 282         dto = dt_object_locate(tgt->lut_reply_data, th->th_dev);
 283         return dt_record_write(env, dto, &tti->tti_buf, &tti->tti_off, th);
 284 }
 285
 286 /* Read the reply data from reply_data file of target @tgt at offset @off
 287  * into structure @lrd
 288  */
 289 static int tgt_reply_data_read(const struct lu_env *env, struct lu_target *tgt,
 290                                struct lsd_reply_data *lrd, loff_t off)
 291 {
 292         int                      rc;
 293         struct tgt_thread_info  *tti = tgt_th_info(env);
 294         struct lsd_reply_data   *buf = &tti->tti_lrd;
 295
 296         tti->tti_off = off;
 297         tti->tti_buf.lb_buf = buf;
 298         tti->tti_buf.lb_len = sizeof(*buf);
 299
 300         rc = dt_record_read(env, tgt->lut_reply_data, &tti->tti_buf,
 301                             &tti->tti_off);
 302         if (rc != 0)
 303                 return rc;
 304
 305         lrd->lrd_transno         = le64_to_cpu(buf->lrd_transno);
 306         lrd->lrd_xid             = le64_to_cpu(buf->lrd_xid);
 307         lrd->lrd_data            = le64_to_cpu(buf->lrd_data);
 308         lrd->lrd_result          = le32_to_cpu(buf->lrd_result);
 309         lrd->lrd_client_gen      = le32_to_cpu(buf->lrd_client_gen);
 310
 311         return 0;
 312 }
 313
 314
 315 /* Free the in-memory reply data structure @trd and release
 316  * the corresponding slot in the reply_data file of target @lut
 317  * Called with ted_lcd_lock held
 318  */
 319 static void tgt_free_reply_data(struct lu_target *lut,
 320                                 struct tg_export_data *ted,
 321                                 struct tg_reply_data *trd)
 322 {
 323         CDEBUG(D_TRACE, "%s: free reply data %p: xid %llu, transno %llu, "
 324                "client gen %u, slot idx %d\n",
 325                lut == NULL ? "" : tgt_name(lut), trd, trd->trd_reply.lrd_xid,
 326                trd->trd_reply.lrd_transno, trd->trd_reply.lrd_client_gen,
 327                trd->trd_index);
 328
 329         LASSERT(mutex_is_locked(&ted->ted_lcd_lock));
 330
 331         list_del(&trd->trd_list);
 332         ted->ted_reply_cnt--;
 333         if (lut != NULL && trd->trd_index != TRD_INDEX_MEMORY)
 334                 tgt_clear_reply_slot(lut, trd->trd_index);
 335         OBD_FREE_PTR(trd);
 336 }
 337
 338 /* Release the reply data @trd from target @lut
 339  * The reply data with the highest transno for this export
 340  * is retained to ensure correctness of target recovery
 341  * Called with ted_lcd_lock held
 342  */
 343 static void tgt_release_reply_data(struct lu_target *lut,
 344                                    struct tg_export_data *ted,
 345                                    struct tg_reply_data *trd)
 346 {
 347         CDEBUG(D_TRACE, "%s: release reply data %p: xid %llu, transno %llu, "
 348                "client gen %u, slot idx %d\n",
 349                lut == NULL ? "" : tgt_name(lut), trd, trd->trd_reply.lrd_xid,
 350                trd->trd_reply.lrd_transno, trd->trd_reply.lrd_client_gen,
 351                trd->trd_index);
 352
 353         LASSERT(mutex_is_locked(&ted->ted_lcd_lock));
 354
 355         /* Do not free the reply data corresponding to the
 356          * highest transno of this export.
 357          * This ensures on-disk reply data is kept and
 358          * last committed transno can be restored from disk in case
 359          * of target recovery
 360          */
 361         if (trd->trd_reply.lrd_transno == ted->ted_lcd->lcd_last_transno) {
 362                 /* free previous retained reply */
 363                 if (ted->ted_reply_last != NULL)
 364                         tgt_free_reply_data(lut, ted, ted->ted_reply_last);
 365                 /* retain the reply */
 366                 list_del_init(&trd->trd_list);
 367                 ted->ted_reply_last = trd;
 368         } else {
 369                 tgt_free_reply_data(lut, ted, trd);
 370         }
 371 }
 372
 373 static inline struct lu_buf *tti_buf_lsd(struct tgt_thread_info *tti)
 374 {
 375         tti->tti_buf.lb_buf = &tti->tti_lsd;
 376         tti->tti_buf.lb_len = sizeof(tti->tti_lsd);
 377         return &tti->tti_buf;
 378 }
 379
 380 static inline struct lu_buf *tti_buf_lcd(struct tgt_thread_info *tti)
 381 {
 382         tti->tti_buf.lb_buf = &tti->tti_lcd;
 383         tti->tti_buf.lb_len = sizeof(tti->tti_lcd);
 384         return &tti->tti_buf;
 385 }
 386
 387 static inline bool tgt_is_multimodrpcs_record(struct lu_target *tgt,
 388                                               struct lsd_client_data *lcd)
 389 {
 390         return tgt->lut_lsd.lsd_feature_incompat & OBD_INCOMPAT_MULTI_RPCS &&
 391                 lcd->lcd_generation != 0;
 392 }
 393
 394 /**
 395  * Allocate in-memory data for client slot related to export.
 396  */
 397 int tgt_client_alloc(struct obd_export *exp)
 398 {
 399         ENTRY;
 400         LASSERT(exp != exp->exp_obd->obd_self_export);
 401
 402         spin_lock_init(&exp->exp_target_data.ted_nodemap_lock);
 403         INIT_LIST_HEAD(&exp->exp_target_data.ted_nodemap_member);
 404         spin_lock_init(&exp->exp_target_data.ted_fmd_lock);
 405         INIT_LIST_HEAD(&exp->exp_target_data.ted_fmd_list);
 406
 407         OBD_ALLOC_PTR(exp->exp_target_data.ted_lcd);
 408         if (exp->exp_target_data.ted_lcd == NULL)
 409                 RETURN(-ENOMEM);
 410         /* Mark that slot is not yet valid, 0 doesn't work here */
 411         exp->exp_target_data.ted_lr_idx = -1;
 412         INIT_LIST_HEAD(&exp->exp_target_data.ted_reply_list);
 413         mutex_init(&exp->exp_target_data.ted_lcd_lock);
 414         RETURN(0);
 415 }
 416 EXPORT_SYMBOL(tgt_client_alloc);
 417
 418 /**
 419  * Free in-memory data for client slot related to export.
 420  */
 421 void tgt_client_free(struct obd_export *exp)
 422 {
 423         struct tg_export_data   *ted = &exp->exp_target_data;
 424         struct lu_target        *lut = class_exp2tgt(exp);
 425         struct tg_reply_data    *trd, *tmp;
 426
 427         LASSERT(exp != exp->exp_obd->obd_self_export);
 428
 429         tgt_fmd_cleanup(exp);
 430
 431         /* free reply data */
 432         mutex_lock(&ted->ted_lcd_lock);
 433         list_for_each_entry_safe(trd, tmp, &ted->ted_reply_list, trd_list) {
 434                 tgt_release_reply_data(lut, ted, trd);
 435         }
 436         if (ted->ted_reply_last != NULL) {
 437                 tgt_free_reply_data(lut, ted, ted->ted_reply_last);
 438                 ted->ted_reply_last = NULL;
 439         }
 440         mutex_unlock(&ted->ted_lcd_lock);
 441
 442         if (!hlist_unhashed(&exp->exp_gen_hash))
 443                 cfs_hash_del(exp->exp_obd->obd_gen_hash,
 444                              &ted->ted_lcd->lcd_generation,
 445                              &exp->exp_gen_hash);
 446
 447         OBD_FREE_PTR(ted->ted_lcd);
 448         ted->ted_lcd = NULL;
 449
 450         /* Target may have been freed (see LU-7430)
 451          * Slot may be not yet assigned */
 452         if (((struct obd_device_target *)(&exp->exp_obd->u))->obt_magic !=
 453             OBT_MAGIC ||
 454             ted->ted_lr_idx < 0)
 455                 return;
 456
 457         /* Clear bit when lcd is freed */
 458         LASSERT(lut && lut->lut_client_bitmap);
 459         if (!test_and_clear_bit(ted->ted_lr_idx, lut->lut_client_bitmap)) {
 460                 CERROR("%s: client %u bit already clear in bitmap\n",
 461                        exp->exp_obd->obd_name, ted->ted_lr_idx);
 462                 LBUG();
 463         }
 464 }
 465 EXPORT_SYMBOL(tgt_client_free);
 466
 467 static inline void tgt_check_lcd(const char *obd_name, int index,
 468                                  struct lsd_client_data *lcd)
 469 {
 470         size_t uuid_size = sizeof(lcd->lcd_uuid);
 471
 472         if (strnlen((char*)lcd->lcd_uuid, uuid_size) == uuid_size) {
 473                 lcd->lcd_uuid[uuid_size - 1] = '\0';
 474
 475                 LCONSOLE_ERROR("the client UUID (%s) on %s for exports stored in last_rcvd(index = %d) is bad!\n",
 476                                lcd->lcd_uuid, obd_name, index);
 477         }
 478 }
 479
 480 static int tgt_client_data_read(const struct lu_env *env, struct lu_target *tgt,
 481                                 struct lsd_client_data *lcd,
 482                                 loff_t *off, int index)
 483 {
 484         struct tgt_thread_info  *tti = tgt_th_info(env);
 485         int                      rc;
 486
 487         tti_buf_lcd(tti);
 488         rc = dt_record_read(env, tgt->lut_last_rcvd, &tti->tti_buf, off);
 489         if (rc == 0) {
 490                 tgt_check_lcd(tgt->lut_obd->obd_name, index, &tti->tti_lcd);
 491                 lcd_le_to_cpu(&tti->tti_lcd, lcd);
 492                 lcd->lcd_last_result = ptlrpc_status_ntoh(lcd->lcd_last_result);
 493                 lcd->lcd_last_close_result =
 494                         ptlrpc_status_ntoh(lcd->lcd_last_close_result);
 495         }
 496
 497         CDEBUG(D_INFO, "%s: read lcd @%lld uuid = %s, last_transno = %llu"
 498                ", last_xid = %llu, last_result = %u, last_data = %u, "
 499                "last_close_transno = %llu, last_close_xid = %llu, "
 500                "last_close_result = %u, rc = %d\n", tgt->lut_obd->obd_name,
 501                *off, lcd->lcd_uuid, lcd->lcd_last_transno, lcd->lcd_last_xid,
 502                lcd->lcd_last_result, lcd->lcd_last_data,
 503                lcd->lcd_last_close_transno, lcd->lcd_last_close_xid,
 504                lcd->lcd_last_close_result, rc);
 505         return rc;
 506 }
 507
 508 static int tgt_client_data_write(const struct lu_env *env,
 509                                  struct lu_target *tgt,
 510                                  struct lsd_client_data *lcd,
 511                                  loff_t *off, struct thandle *th)
 512 {
 513         struct tgt_thread_info *tti = tgt_th_info(env);
 514         struct dt_object        *dto;
 515
 516         lcd->lcd_last_result = ptlrpc_status_hton(lcd->lcd_last_result);
 517         lcd->lcd_last_close_result =
 518                 ptlrpc_status_hton(lcd->lcd_last_close_result);
 519         lcd_cpu_to_le(lcd, &tti->tti_lcd);
 520         tti_buf_lcd(tti);
 521
 522         dto = dt_object_locate(tgt->lut_last_rcvd, th->th_dev);
 523         return dt_record_write(env, dto, &tti->tti_buf, off, th);
 524 }
 525
 526 struct tgt_new_client_callback {
 527         struct dt_txn_commit_cb  lncc_cb;
 528         struct obd_export       *lncc_exp;
 529 };
 530
 531 static void tgt_cb_new_client(struct lu_env *env, struct thandle *th,
 532                               struct dt_txn_commit_cb *cb, int err)
 533 {
 534         struct tgt_new_client_callback *ccb;
 535
 536         ccb = container_of(cb, struct tgt_new_client_callback, lncc_cb);
 537
 538         LASSERT(ccb->lncc_exp->exp_obd);
 539
 540         CDEBUG(D_RPCTRACE, "%s: committing for initial connect of %s\n",
 541                ccb->lncc_exp->exp_obd->obd_name,
 542                ccb->lncc_exp->exp_client_uuid.uuid);
 543
 544         spin_lock(&ccb->lncc_exp->exp_lock);
 545
 546         ccb->lncc_exp->exp_need_sync = 0;
 547
 548         spin_unlock(&ccb->lncc_exp->exp_lock);
 549         class_export_cb_put(ccb->lncc_exp);
 550
 551         OBD_FREE_PTR(ccb);
 552 }
 553
 554 int tgt_new_client_cb_add(struct thandle *th, struct obd_export *exp)
 555 {
 556         struct tgt_new_client_callback  *ccb;
 557         struct dt_txn_commit_cb         *dcb;
 558         int                              rc;
 559
 560         OBD_ALLOC_PTR(ccb);
 561         if (ccb == NULL)
 562                 return -ENOMEM;
 563
 564         ccb->lncc_exp = class_export_cb_get(exp);
 565
 566         dcb = &ccb->lncc_cb;
 567         dcb->dcb_func = tgt_cb_new_client;
 568         INIT_LIST_HEAD(&dcb->dcb_linkage);
 569         strlcpy(dcb->dcb_name, "tgt_cb_new_client", sizeof(dcb->dcb_name));
 570
 571         rc = dt_trans_cb_add(th, dcb);
 572         if (rc) {
 573                 class_export_cb_put(exp);
 574                 OBD_FREE_PTR(ccb);
 575         }
 576         return rc;
 577 }
 578
 579 /**
 580  * Update client data in last_rcvd
 581  */
 582 static int tgt_client_data_update(const struct lu_env *env,
 583                                   struct obd_export *exp)
 584 {
 585         struct tg_export_data   *ted = &exp->exp_target_data;
 586         struct lu_target        *tgt = class_exp2tgt(exp);
 587         struct tgt_thread_info  *tti = tgt_th_info(env);
 588         struct thandle          *th;
 589         int                      rc = 0;
 590
 591         ENTRY;
 592
 593         if (unlikely(tgt == NULL)) {
 594                 CDEBUG(D_ERROR, "%s: No target for connected export\n",
 595                           class_exp2obd(exp)->obd_name);
 596                 RETURN(-EINVAL);
 597         }
 598
 599         if (tgt->lut_bottom->dd_rdonly)
 600                 RETURN(0);
 601
 602         th = dt_trans_create(env, tgt->lut_bottom);
 603         if (IS_ERR(th))
 604                 RETURN(PTR_ERR(th));
 605
 606         tti_buf_lcd(tti);
 607         rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
 608                                      &tti->tti_buf,
 609                                      ted->ted_lr_off, th);
 610         if (rc)
 611                 GOTO(out, rc);
 612
 613         rc = dt_trans_start_local(env, tgt->lut_bottom, th);
 614         if (rc)
 615                 GOTO(out, rc);
 616
 617         mutex_lock(&ted->ted_lcd_lock);
 618
 619         /*
 620          * Until this operations will be committed the sync is needed
 621          * for this export. This should be done _after_ starting the
 622          * transaction so that many connecting clients will not bring
 623          * server down with lots of sync writes.
 624          */
 625         rc = tgt_new_client_cb_add(th, exp);
 626         if (rc) {
 627                 /* can't add callback, do sync now */
 628                 th->th_sync = 1;
 629         } else {
 630                 spin_lock(&exp->exp_lock);
 631                 exp->exp_need_sync = 1;
 632                 spin_unlock(&exp->exp_lock);
 633         }
 634
 635         tti->tti_off = ted->ted_lr_off;
 636         rc = tgt_client_data_write(env, tgt, ted->ted_lcd, &tti->tti_off, th);
 637
 638         mutex_unlock(&ted->ted_lcd_lock);
 639
 640         EXIT;
 641 out:
 642         dt_trans_stop(env, tgt->lut_bottom, th);
 643         CDEBUG(D_INFO, "%s: update last_rcvd client data for UUID = %s, "
 644                "last_transno = %llu: rc = %d\n", tgt->lut_obd->obd_name,
 645                tgt->lut_lsd.lsd_uuid, tgt->lut_lsd.lsd_last_transno, rc);
 646
 647         return rc;
 648 }
 649
 650 static int tgt_server_data_read(const struct lu_env *env, struct lu_target *tgt)
 651 {
 652         struct tgt_thread_info  *tti = tgt_th_info(env);
 653         int                      rc;
 654
 655         tti->tti_off = 0;
 656         tti_buf_lsd(tti);
 657         rc = dt_record_read(env, tgt->lut_last_rcvd, &tti->tti_buf,
 658                             &tti->tti_off);
 659         if (rc == 0)
 660                 lsd_le_to_cpu(&tti->tti_lsd, &tgt->lut_lsd);
 661
 662         CDEBUG(D_INFO, "%s: read last_rcvd server data for UUID = %s, "
 663                "last_transno = %llu: rc = %d\n", tgt->lut_obd->obd_name,
 664                tgt->lut_lsd.lsd_uuid, tgt->lut_lsd.lsd_last_transno, rc);
 665         return rc;
 666 }
 667
 668 static int tgt_server_data_write(const struct lu_env *env,
 669                                  struct lu_target *tgt, struct thandle *th)
 670 {
 671         struct tgt_thread_info  *tti = tgt_th_info(env);
 672         struct dt_object        *dto;
 673         int                      rc;
 674
 675         ENTRY;
 676
 677         tti->tti_off = 0;
 678         tti_buf_lsd(tti);
 679         lsd_cpu_to_le(&tgt->lut_lsd, &tti->tti_lsd);
 680
 681         dto = dt_object_locate(tgt->lut_last_rcvd, th->th_dev);
 682         rc = dt_record_write(env, dto, &tti->tti_buf, &tti->tti_off, th);
 683
 684         CDEBUG(D_INFO, "%s: write last_rcvd server data for UUID = %s, "
 685                "last_transno = %llu: rc = %d\n", tgt->lut_obd->obd_name,
 686                tgt->lut_lsd.lsd_uuid, tgt->lut_lsd.lsd_last_transno, rc);
 687
 688         RETURN(rc);
 689 }
 690
 691 /**
 692  * Update server data in last_rcvd
 693  */
 694 int tgt_server_data_update(const struct lu_env *env, struct lu_target *tgt,
 695                            int sync)
 696 {
 697         struct tgt_thread_info  *tti = tgt_th_info(env);
 698         struct thandle          *th;
 699         int                      rc = 0;
 700
 701         ENTRY;
 702
 703         CDEBUG(D_SUPER,
 704                "%s: mount_count is %llu, last_transno is %llu\n",
 705                tgt->lut_lsd.lsd_uuid, obd2obt(tgt->lut_obd)->obt_mount_count,
 706                tgt->lut_last_transno);
 707
 708         /* Always save latest transno to keep it fresh */
 709         spin_lock(&tgt->lut_translock);
 710         tgt->lut_lsd.lsd_last_transno = tgt->lut_last_transno;
 711         spin_unlock(&tgt->lut_translock);
 712
 713         if (tgt->lut_bottom->dd_rdonly)
 714                 RETURN(0);
 715
 716         th = dt_trans_create(env, tgt->lut_bottom);
 717         if (IS_ERR(th))
 718                 RETURN(PTR_ERR(th));
 719
 720         th->th_sync = sync;
 721
 722         tti_buf_lsd(tti);
 723         rc = dt_declare_record_write(env, tgt->lut_last_rcvd,
 724                                      &tti->tti_buf, tti->tti_off, th);
 725         if (rc)
 726                 GOTO(out, rc);
 727
 728         rc = dt_trans_start(env, tgt->lut_bottom, th);
 729         if (rc)
 730                 GOTO(out, rc);
 731
 732         rc = tgt_server_data_write(env, tgt, th);
 733 out:
 734         dt_trans_stop(env, tgt->lut_bottom, th);
 735
 736         CDEBUG(D_INFO, "%s: update last_rcvd server data for UUID = %s, "
 737                "last_transno = %llu: rc = %d\n", tgt->lut_obd->obd_name,
 738                tgt->lut_lsd.lsd_uuid, tgt->lut_lsd.lsd_last_transno, rc);
 739         RETURN(rc);
 740 }
 741 EXPORT_SYMBOL(tgt_server_data_update);
 742
 743 static int tgt_truncate_last_rcvd(const struct lu_env *env,
 744                                   struct lu_target *tgt, loff_t size)
 745 {
 746         struct dt_object *dt = tgt->lut_last_rcvd;
 747         struct thandle   *th;
 748         struct lu_attr    attr;
 749         int               rc;
 750
 751         ENTRY;
 752
 753         if (tgt->lut_bottom->dd_rdonly)
 754                 RETURN(0);
 755
 756         attr.la_size = size;
 757         attr.la_valid = LA_SIZE;
 758
 759         th = dt_trans_create(env, tgt->lut_bottom);
 760         if (IS_ERR(th))
 761                 RETURN(PTR_ERR(th));
 762         rc = dt_declare_punch(env, dt, size, OBD_OBJECT_EOF, th);
 763         if (rc)
 764                 GOTO(cleanup, rc);
 765         rc = dt_declare_attr_set(env, dt, &attr, th);
 766         if (rc)
 767                 GOTO(cleanup, rc);
 768         rc = dt_trans_start_local(env, tgt->lut_bottom, th);
 769         if (rc)
 770                 GOTO(cleanup, rc);
 771
 772         rc = dt_punch(env, dt, size, OBD_OBJECT_EOF, th);
 773         if (rc == 0)
 774                 rc = dt_attr_set(env, dt, &attr, th);
 775
 776 cleanup:
 777         dt_trans_stop(env, tgt->lut_bottom, th);
 778
 779         RETURN(rc);
 780 }
 781
 782 static void tgt_client_epoch_update(const struct lu_env *env,
 783                                     struct obd_export *exp)
 784 {
 785         struct lsd_client_data  *lcd = exp->exp_target_data.ted_lcd;
 786         struct lu_target        *tgt = class_exp2tgt(exp);
 787
 788         LASSERT(tgt && tgt->lut_bottom);
 789         /** VBR: set client last_epoch to current epoch */
 790         if (lcd->lcd_last_epoch >= tgt->lut_lsd.lsd_start_epoch)
 791                 return;
 792         lcd->lcd_last_epoch = tgt->lut_lsd.lsd_start_epoch;
 793         tgt_client_data_update(env, exp);
 794 }
 795
 796 /**
 797  * Update boot epoch when recovery ends
 798  */
 799 void tgt_boot_epoch_update(struct lu_target *tgt)
 800 {
 801         struct lu_env            env;
 802         struct ptlrpc_request   *req;
 803         __u32                    start_epoch;
 804         LIST_HEAD(client_list);
 805         int                      rc;
 806
 807         if (tgt->lut_obd->obd_stopping)
 808                 return;
 809
 810         rc = lu_env_init(&env, LCT_DT_THREAD);
 811         if (rc) {
 812                 CERROR("%s: can't initialize environment: rc = %d\n",
 813                         tgt->lut_obd->obd_name, rc);
 814                 return;
 815         }
 816
 817         spin_lock(&tgt->lut_translock);
 818         start_epoch = (tgt->lut_last_transno >> LR_EPOCH_BITS) + 1;
 819         tgt->lut_last_transno = (__u64)start_epoch << LR_EPOCH_BITS;
 820         tgt->lut_lsd.lsd_start_epoch = start_epoch;
 821         spin_unlock(&tgt->lut_translock);
 822
 823         /**
 824          * The recovery is not yet finished and final queue can still be updated
 825          * with resend requests. Move final list to separate one for processing
 826          */
 827         spin_lock(&tgt->lut_obd->obd_recovery_task_lock);
 828         list_splice_init(&tgt->lut_obd->obd_final_req_queue, &client_list);
 829         spin_unlock(&tgt->lut_obd->obd_recovery_task_lock);
 830
 831         /**
 832          * go through list of exports participated in recovery and
 833          * set new epoch for them
 834          */
 835         list_for_each_entry(req, &client_list, rq_list) {
 836                 LASSERT(!req->rq_export->exp_delayed);
 837                 if (!req->rq_export->exp_vbr_failed)
 838                         tgt_client_epoch_update(&env, req->rq_export);
 839         }
 840         /** return list back at once */
 841         spin_lock(&tgt->lut_obd->obd_recovery_task_lock);
 842         list_splice_init(&client_list, &tgt->lut_obd->obd_final_req_queue);
 843         spin_unlock(&tgt->lut_obd->obd_recovery_task_lock);
 844
 845         /**
 846          * Clear MULTI RPCS incompatibility flag if there is no multi-rpcs
 847          * client in last_rcvd file
 848          */
 849         if (atomic_read(&tgt->lut_num_clients) == 0)
 850                 tgt->lut_lsd.lsd_feature_incompat &= ~OBD_INCOMPAT_MULTI_RPCS;
 851
 852         /** update server epoch */
 853         tgt_server_data_update(&env, tgt, 1);
 854         lu_env_fini(&env);
 855 }
 856
 857 /**
 858  * commit callback, need to update last_committed value
 859  */
 860 struct tgt_last_committed_callback {
 861         struct dt_txn_commit_cb  llcc_cb;
 862         struct lu_target        *llcc_tgt;
 863         struct obd_export       *llcc_exp;
 864         __u64                    llcc_transno;
 865 };
 866
 867 static void tgt_cb_last_committed(struct lu_env *env, struct thandle *th,
 868                                   struct dt_txn_commit_cb *cb, int err)
 869 {
 870         struct tgt_last_committed_callback *ccb;
 871
 872         ccb = container_of(cb, struct tgt_last_committed_callback, llcc_cb);
 873
 874         LASSERT(ccb->llcc_exp);
 875         LASSERT(ccb->llcc_tgt != NULL);
 876         LASSERT(ccb->llcc_exp->exp_obd == ccb->llcc_tgt->lut_obd);
 877
 878         if (th->th_reserved_quota.lqi_space > 0) {
 879                 CDEBUG(D_QUOTA, "free quota %llu %llu\n",
 880                        th->th_reserved_quota.lqi_id.qid_gid,
 881                        th->th_reserved_quota.lqi_space);
 882
 883                 /* env can be NULL for freeing reserved quota */
 884                 th->th_reserved_quota.lqi_space *= -1;
 885                 dt_reserve_or_free_quota(NULL, th->th_dev,
 886                                          &th->th_reserved_quota);
 887         }
 888
 889         /* error hit, don't update last committed to provide chance to
 890          * replay data after fail */
 891         if (err != 0)
 892                 goto out;
 893
 894         /* Fast path w/o spinlock, if exp_last_committed was updated
 895          * with higher transno, no need to take spinlock and check,
 896          * also no need to update obd_last_committed. */
 897         if (ccb->llcc_transno <= ccb->llcc_exp->exp_last_committed)
 898                 goto out;
 899         spin_lock(&ccb->llcc_tgt->lut_translock);
 900         if (ccb->llcc_transno > ccb->llcc_tgt->lut_obd->obd_last_committed)
 901                 ccb->llcc_tgt->lut_obd->obd_last_committed = ccb->llcc_transno;
 902
 903         if (ccb->llcc_transno > ccb->llcc_exp->exp_last_committed) {
 904                 ccb->llcc_exp->exp_last_committed = ccb->llcc_transno;
 905                 spin_unlock(&ccb->llcc_tgt->lut_translock);
 906
 907                 ptlrpc_commit_replies(ccb->llcc_exp);
 908                 tgt_cancel_slc_locks(ccb->llcc_tgt, ccb->llcc_transno);
 909         } else {
 910                 spin_unlock(&ccb->llcc_tgt->lut_translock);
 911         }
 912
 913         CDEBUG(D_HA, "%s: transno %lld is committed\n",
 914                ccb->llcc_tgt->lut_obd->obd_name, ccb->llcc_transno);
 915
 916 out:
 917         class_export_cb_put(ccb->llcc_exp);
 918         OBD_FREE_PTR(ccb);
 919 }
 920
 921 /**
 922  * Add commit callback function, it returns a non-zero value to inform
 923  * caller to use sync transaction if necessary.
 924  */
 925 static int tgt_last_commit_cb_add(struct thandle *th, struct lu_target *tgt,
 926                                   struct obd_export *exp, __u64 transno)
 927 {
 928         struct tgt_last_committed_callback      *ccb;
 929         struct dt_txn_commit_cb                 *dcb;
 930         int                                      rc;
 931
 932         OBD_ALLOC_PTR(ccb);
 933         if (ccb == NULL)
 934                 return -ENOMEM;
 935
 936         ccb->llcc_tgt = tgt;
 937         ccb->llcc_exp = class_export_cb_get(exp);
 938         ccb->llcc_transno = transno;
 939
 940         dcb = &ccb->llcc_cb;
 941         dcb->dcb_func = tgt_cb_last_committed;
 942         INIT_LIST_HEAD(&dcb->dcb_linkage);
 943         strlcpy(dcb->dcb_name, "tgt_cb_last_committed", sizeof(dcb->dcb_name));
 944
 945         rc = dt_trans_cb_add(th, dcb);
 946         if (rc) {
 947                 class_export_cb_put(exp);
 948                 OBD_FREE_PTR(ccb);
 949         }
 950
 951         if (exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 952                 /* report failure to force synchronous operation */
 953                 return -EPERM;
 954
 955         /* if exp_need_sync is set, return non-zero value to force
 956          * a sync transaction. */
 957         return rc ? rc : exp->exp_need_sync;
 958 }
 959
 960 static int tgt_is_local_client(const struct lu_env *env,
 961                                       struct obd_export *exp)
 962 {
 963         struct lu_target        *tgt = class_exp2tgt(exp);
 964         struct tgt_session_info *tsi = tgt_ses_info(env);
 965         struct ptlrpc_request   *req = tgt_ses_req(tsi);
 966
 967         if (exp_connect_flags(exp) & OBD_CONNECT_MDS ||
 968             exp_connect_flags(exp) & OBD_CONNECT_MDS_MDS)
 969                 return 0;
 970         if (tgt->lut_local_recovery)
 971                 return 0;
 972         if (!req)
 973                 return 0;
 974         if (!LNetIsPeerLocal(&req->rq_peer.nid))
 975                 return 0;
 976
 977         return 1;
 978 }
 979
 980 /**
 981  * Add new client to the last_rcvd upon new connection.
 982  *
 983  * We use a bitmap to locate a free space in the last_rcvd file and initialize
 984  * tg_export_data.
 985  */
 986 int tgt_client_new(const struct lu_env *env, struct obd_export *exp)
 987 {
 988         struct tg_export_data   *ted = &exp->exp_target_data;
 989         struct lu_target        *tgt = class_exp2tgt(exp);
 990         int                      rc = 0, idx;
 991
 992         ENTRY;
 993
 994         LASSERT(tgt && tgt->lut_client_bitmap != NULL);
 995         if (!strcmp(ted->ted_lcd->lcd_uuid, tgt->lut_obd->obd_uuid.uuid))
 996                 RETURN(0);
 997
 998         if (exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
 999                 RETURN(0);
1000
1001         if (tgt_is_local_client(env, exp)) {
1002                 LCONSOLE_WARN("%s: local client %s w/o recovery\n",
1003                               exp->exp_obd->obd_name, ted->ted_lcd->lcd_uuid);
1004                 exp->exp_no_recovery = 1;
1005                 RETURN(0);
1006         }
1007
1008         /* the bitmap operations can handle cl_idx > sizeof(long) * 8, so
1009          * there's no need for extra complication here
1010          */
1011         idx = find_first_zero_bit(tgt->lut_client_bitmap, LR_MAX_CLIENTS);
1012 repeat:
1013         if (idx >= LR_MAX_CLIENTS ||
1014             OBD_FAIL_CHECK(OBD_FAIL_MDS_CLIENT_ADD)) {
1015                 CERROR("%s: no room for %u clients - fix LR_MAX_CLIENTS\n",
1016                        tgt->lut_obd->obd_name,  idx);
1017                 RETURN(-EOVERFLOW);
1018         }
1019         if (test_and_set_bit(idx, tgt->lut_client_bitmap)) {
1020                 idx = find_next_zero_bit(tgt->lut_client_bitmap,
1021                                              LR_MAX_CLIENTS, idx);
1022                 goto repeat;
1023         }
1024
1025         ted->ted_lr_idx = idx;
1026         ted->ted_lr_off = tgt->lut_lsd.lsd_client_start +
1027                           idx * tgt->lut_lsd.lsd_client_size;
1028
1029         LASSERTF(ted->ted_lr_off > 0, "ted_lr_off = %llu\n", ted->ted_lr_off);
1030
1031         if (tgt_is_multimodrpcs_client(exp)) {
1032                 /* Set MULTI RPCS incompatibility flag to prevent previous
1033                  * Lustre versions to mount a target with reply_data file */
1034                 if (!(tgt->lut_lsd.lsd_feature_incompat &
1035                       OBD_INCOMPAT_MULTI_RPCS)) {
1036                         tgt->lut_lsd.lsd_feature_incompat |=
1037                                                         OBD_INCOMPAT_MULTI_RPCS;
1038                         rc = tgt_server_data_update(env, tgt, 1);
1039                         if (rc < 0) {
1040                                 CERROR("%s: unable to set MULTI RPCS "
1041                                        "incompatibility flag\n",
1042                                        exp->exp_obd->obd_name);
1043                                 RETURN(rc);
1044                         }
1045                 }
1046
1047                 /* assign client slot generation */
1048                 ted->ted_lcd->lcd_generation =
1049                                 atomic_inc_return(&tgt->lut_client_generation);
1050         } else {
1051                 ted->ted_lcd->lcd_generation = 0;
1052         }
1053
1054         CDEBUG(D_INFO, "%s: new client at index %d (%llu) with UUID '%s' "
1055                "generation %d\n",
1056                tgt->lut_obd->obd_name, ted->ted_lr_idx, ted->ted_lr_off,
1057                ted->ted_lcd->lcd_uuid, ted->ted_lcd->lcd_generation);
1058
1059         if (OBD_FAIL_CHECK(OBD_FAIL_TGT_CLIENT_ADD))
1060                 RETURN(-ENOSPC);
1061
1062         rc = tgt_client_data_update(env, exp);
1063         if (rc) {
1064                 CERROR("%s: Failed to write client lcd at idx %d, rc %d\n",
1065                        tgt->lut_obd->obd_name, idx, rc);
1066                 RETURN(rc);
1067         }
1068
1069         if (tgt_is_multimodrpcs_client(exp))
1070                 atomic_inc(&tgt->lut_num_clients);
1071
1072         RETURN(0);
1073 }
1074 EXPORT_SYMBOL(tgt_client_new);
1075
1076 /* Add an existing client to the MDS in-memory state based on
1077  * a client that was previously found in the last_rcvd file and
1078  * already has an assigned slot (idx >= 0).
1079  *
1080  * It should not be possible to fail adding an existing client - otherwise
1081  * mdt_init_server_data() callsite needs to be fixed.
1082  */
1083 int tgt_client_add(const struct lu_env *env,  struct obd_export *exp, int idx)
1084 {
1085         struct tg_export_data   *ted = &exp->exp_target_data;
1086         struct lu_target        *tgt = class_exp2tgt(exp);
1087
1088         ENTRY;
1089
1090         LASSERT(tgt && tgt->lut_client_bitmap != NULL);
1091         LASSERTF(idx >= 0, "%d\n", idx);
1092
1093         if (!strcmp(ted->ted_lcd->lcd_uuid, tgt->lut_obd->obd_uuid.uuid) ||
1094             exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT)
1095                 RETURN(0);
1096
1097         if (test_and_set_bit(idx, tgt->lut_client_bitmap)) {
1098                 CERROR("%s: client %d: bit already set in bitmap!!\n",
1099                        tgt->lut_obd->obd_name,  idx);
1100                 LBUG();
1101         }
1102
1103         CDEBUG(D_INFO, "%s: client at idx %d with UUID '%s' added, "
1104                "generation %d\n",
1105                tgt->lut_obd->obd_name, idx, ted->ted_lcd->lcd_uuid,
1106                ted->ted_lcd->lcd_generation);
1107
1108         ted->ted_lr_idx = idx;
1109         ted->ted_lr_off = tgt->lut_lsd.lsd_client_start +
1110                           idx * tgt->lut_lsd.lsd_client_size;
1111
1112         mutex_init(&ted->ted_lcd_lock);
1113
1114         LASSERTF(ted->ted_lr_off > 0, "ted_lr_off = %llu\n", ted->ted_lr_off);
1115
1116         RETURN(0);
1117 }
1118
1119 int tgt_client_del(const struct lu_env *env, struct obd_export *exp)
1120 {
1121         struct tg_export_data   *ted = &exp->exp_target_data;
1122         struct lu_target        *tgt = class_exp2tgt(exp);
1123         int                      rc;
1124
1125         ENTRY;
1126
1127         LASSERT(ted->ted_lcd);
1128
1129         if (unlikely(tgt == NULL)) {
1130                 CDEBUG(D_ERROR, "%s: No target for connected export\n",
1131                        class_exp2obd(exp)->obd_name);
1132                 RETURN(-EINVAL);
1133         }
1134
1135         /* XXX if lcd_uuid were a real obd_uuid, I could use obd_uuid_equals */
1136         if (!strcmp((char *)ted->ted_lcd->lcd_uuid,
1137                     (char *)tgt->lut_obd->obd_uuid.uuid) ||
1138             exp_connect_flags(exp) & OBD_CONNECT_LIGHTWEIGHT ||
1139             exp->exp_no_recovery)
1140                 RETURN(0);
1141
1142         /* Slot may be not yet assigned, use case is race between Client
1143          * reconnect and forced eviction */
1144         if (ted->ted_lr_idx < 0) {
1145                 CWARN("%s: client with UUID '%s' not in bitmap\n",
1146                       tgt->lut_obd->obd_name, ted->ted_lcd->lcd_uuid);
1147                 RETURN(0);
1148         }
1149
1150         CDEBUG(D_INFO, "%s: del client at idx %u, off %lld, UUID '%s'\n",
1151                tgt->lut_obd->obd_name, ted->ted_lr_idx, ted->ted_lr_off,
1152                ted->ted_lcd->lcd_uuid);
1153
1154         /* Clear the bit _after_ zeroing out the client so we don't
1155            race with filter_client_add and zero out new clients.*/
1156         if (!test_bit(ted->ted_lr_idx, tgt->lut_client_bitmap)) {
1157                 CERROR("%s: client %u: bit already clear in bitmap!!\n",
1158                        tgt->lut_obd->obd_name, ted->ted_lr_idx);
1159                 LBUG();
1160         }
1161
1162         /* Do not erase record for recoverable client. */
1163         if (exp->exp_flags & OBD_OPT_FAILOVER)
1164                 RETURN(0);
1165
1166         if (OBD_FAIL_CHECK(OBD_FAIL_TGT_CLIENT_DEL))
1167                 RETURN(0);
1168
1169         /* Make sure the server's last_transno is up to date.
1170          * This should be done before zeroing client slot so last_transno will
1171          * be in server data or in client data in case of failure */
1172         rc = tgt_server_data_update(env, tgt, 0);
1173         if (rc != 0) {
1174                 CERROR("%s: failed to update server data, skip client %s "
1175                        "zeroing, rc %d\n", tgt->lut_obd->obd_name,
1176                        ted->ted_lcd->lcd_uuid, rc);
1177                 RETURN(rc);
1178         }
1179
1180         /* Race between an eviction and a disconnection ?*/
1181         mutex_lock(&ted->ted_lcd_lock);
1182         if (ted->ted_lcd->lcd_uuid[0] == '\0') {
1183                 mutex_unlock(&ted->ted_lcd_lock);
1184                 RETURN(rc);
1185         }
1186
1187         memset(ted->ted_lcd->lcd_uuid, 0, sizeof ted->ted_lcd->lcd_uuid);
1188         mutex_unlock(&ted->ted_lcd_lock);
1189
1190         rc = tgt_client_data_update(env, exp);
1191
1192         if (!rc && tgt_is_multimodrpcs_record(tgt, ted->ted_lcd))
1193                 atomic_dec(&tgt->lut_num_clients);
1194
1195         CDEBUG(rc == 0 ? D_INFO : D_ERROR,
1196                "%s: zeroing out client %s at idx %u (%llu), rc %d\n",
1197                tgt->lut_obd->obd_name, ted->ted_lcd->lcd_uuid,
1198                ted->ted_lr_idx, ted->ted_lr_off, rc);
1199         RETURN(rc);
1200 }
1201 EXPORT_SYMBOL(tgt_client_del);
1202
1203 static void tgt_clean_by_tag(struct obd_export *exp, __u64 xid, __u16 tag)
1204 {
1205         struct tg_export_data   *ted = &exp->exp_target_data;
1206         struct lu_target        *lut = class_exp2tgt(exp);
1207         struct tg_reply_data    *trd, *tmp;
1208
1209         if (tag == 0)
1210                 return;
1211
1212         list_for_each_entry_safe(trd, tmp, &ted->ted_reply_list, trd_list) {
1213                 if (trd->trd_tag != tag)
1214                         continue;
1215
1216                 LASSERT(ergo(tgt_is_increasing_xid_client(exp),
1217                              trd->trd_reply.lrd_xid <= xid));
1218
1219                 ted->ted_release_tag++;
1220                 tgt_release_reply_data(lut, ted, trd);
1221         }
1222 }
1223
1224 static int tgt_add_reply_data(const struct lu_env *env, struct lu_target *tgt,
1225                        struct tg_export_data *ted, struct tg_reply_data *trd,
1226                        struct ptlrpc_request *req,
1227                        struct thandle *th, bool update_lrd_file)
1228 {
1229         struct lsd_reply_data   *lrd;
1230         int     i;
1231         int     rc;
1232
1233         lrd = &trd->trd_reply;
1234         /* update export last transno */
1235         mutex_lock(&ted->ted_lcd_lock);
1236         if (lrd->lrd_transno > ted->ted_lcd->lcd_last_transno)
1237                 ted->ted_lcd->lcd_last_transno = lrd->lrd_transno;
1238         mutex_unlock(&ted->ted_lcd_lock);
1239
1240         if (tgt != NULL) {
1241                 /* find a empty slot */
1242                 i = tgt_find_free_reply_slot(tgt);
1243                 if (unlikely(i < 0)) {
1244                         CERROR("%s: couldn't find a slot for reply data: "
1245                                "rc = %d\n", tgt_name(tgt), i);
1246                         RETURN(i);
1247                 }
1248                 trd->trd_index = i;
1249
1250                 if (update_lrd_file) {
1251                         loff_t  off;
1252
1253                         /* write reply data to disk */
1254                         off = sizeof(struct lsd_reply_header) + sizeof(*lrd) * i;
1255                         rc = tgt_reply_data_write(env, tgt, lrd, off, th);
1256                         if (unlikely(rc != 0)) {
1257                                 CERROR("%s: can't update %s file: rc = %d\n",
1258                                        tgt_name(tgt), REPLY_DATA, rc);
1259                                 GOTO(free_slot, rc);
1260                         }
1261                 }
1262         } else {
1263                 trd->trd_index = TRD_INDEX_MEMORY;
1264         }
1265
1266         /* add reply data to target export's reply list */
1267         mutex_lock(&ted->ted_lcd_lock);
1268         if (req != NULL) {
1269                 int exclude = tgt_is_increasing_xid_client(req->rq_export) ?
1270                               MSG_REPLAY : MSG_REPLAY|MSG_RESENT;
1271
1272                 if (req->rq_obsolete) {
1273                         CDEBUG(D_INFO,
1274                                "drop reply data update for obsolete req xid=%llu,"
1275                                "transno=%llu, tag=%hu\n", req->rq_xid,
1276                                lrd->lrd_transno, trd->trd_tag);
1277                         mutex_unlock(&ted->ted_lcd_lock);
1278                         GOTO(free_slot, rc = -EBADR);
1279                 }
1280
1281                 if (!(lustre_msg_get_flags(req->rq_reqmsg) & exclude))
1282                         tgt_clean_by_tag(req->rq_export, req->rq_xid,
1283                                          trd->trd_tag);
1284         }
1285         list_add(&trd->trd_list, &ted->ted_reply_list);
1286         ted->ted_reply_cnt++;
1287         if (ted->ted_reply_cnt > ted->ted_reply_max)
1288                 ted->ted_reply_max = ted->ted_reply_cnt;
1289         mutex_unlock(&ted->ted_lcd_lock);
1290
1291         CDEBUG(D_TRACE, "add reply %p: xid %llu, transno %llu, "
1292                "tag %hu, client gen %u, slot idx %d\n",
1293                trd, lrd->lrd_xid, lrd->lrd_transno,
1294                trd->trd_tag, lrd->lrd_client_gen, trd->trd_index);
1295
1296         RETURN(0);
1297
1298 free_slot:
1299         if (tgt != NULL)
1300                 tgt_clear_reply_slot(tgt, trd->trd_index);
1301         return rc;
1302 }
1303
1304 int tgt_mk_reply_data(const struct lu_env *env,
1305                       struct lu_target *tgt,
1306                       struct tg_export_data *ted,
1307                       struct ptlrpc_request *req,
1308                       __u64 opdata,
1309                       struct thandle *th,
1310                       bool write_update,
1311                       __u64 transno)
1312 {
1313         struct tg_reply_data    *trd;
1314         struct lsd_reply_data   *lrd;
1315         __u64                   *pre_versions = NULL;
1316         int                     rc;
1317         struct tgt_session_info *tsi = NULL;
1318
1319         OBD_ALLOC_PTR(trd);
1320         if (unlikely(trd == NULL))
1321                 RETURN(-ENOMEM);
1322
1323         if (env != NULL)
1324                 tsi = tgt_ses_info(env);
1325
1326         /* fill reply data information */
1327         lrd = &trd->trd_reply;
1328         lrd->lrd_transno = transno;
1329         if (req != NULL) {
1330                 lrd->lrd_xid = req->rq_xid;
1331                 trd->trd_tag = lustre_msg_get_tag(req->rq_reqmsg);
1332                 lrd->lrd_client_gen = ted->ted_lcd->lcd_generation;
1333                 if (write_update) {
1334                         pre_versions = lustre_msg_get_versions(req->rq_repmsg);
1335                         lrd->lrd_result = th->th_result;
1336                 }
1337         } else {
1338                 LASSERT(env != NULL);
1339                 LASSERT(tsi->tsi_xid != 0);
1340
1341                 lrd->lrd_xid = tsi->tsi_xid;
1342                 lrd->lrd_result = tsi->tsi_result;
1343                 lrd->lrd_client_gen = tsi->tsi_client_gen;
1344         }
1345
1346         lrd->lrd_data = opdata;
1347         if (pre_versions) {
1348                 trd->trd_pre_versions[0] = pre_versions[0];
1349                 trd->trd_pre_versions[1] = pre_versions[1];
1350                 trd->trd_pre_versions[2] = pre_versions[2];
1351                 trd->trd_pre_versions[3] = pre_versions[3];
1352         }
1353
1354         if (tsi && tsi->tsi_open_obj)
1355                 trd->trd_object = *lu_object_fid(&tsi->tsi_open_obj->do_lu);
1356
1357         rc = tgt_add_reply_data(env, tgt, ted, trd, req,
1358                                 th, write_update);
1359         if (rc < 0) {
1360                 OBD_FREE_PTR(trd);
1361                 if (rc == -EBADR)
1362                         rc = 0;
1363         }
1364         return rc;
1365
1366 }
1367 EXPORT_SYMBOL(tgt_mk_reply_data);
1368
1369 /*
1370  * last_rcvd & last_committed update callbacks
1371  */
1372 static int tgt_last_rcvd_update(const struct lu_env *env, struct lu_target *tgt,
1373                                 struct dt_object *obj, __u64 opdata,
1374                                 struct thandle *th, struct ptlrpc_request *req)
1375 {
1376         struct tgt_thread_info  *tti = tgt_th_info(env);
1377         struct tgt_session_info *tsi = tgt_ses_info(env);
1378         struct obd_export *exp = tsi->tsi_exp;
1379         struct tg_export_data *ted;
1380         __u64 *transno_p;
1381         bool nolcd = false;
1382         int rc = 0;
1383
1384         ENTRY;
1385
1386
1387         LASSERT(exp != NULL);
1388         ted = &exp->exp_target_data;
1389
1390         /* Some clients don't support recovery, and they don't have last_rcvd
1391          * client data:
1392          * 1. lightweight clients.
1393          * 2. local clients on MDS which doesn't enable "localrecov".
1394          * 3. OFD connect may cause transaction before export has last_rcvd
1395          *    slot.
1396          */
1397         if (ted->ted_lr_idx < 0)
1398                 nolcd = true;
1399
1400         if (req != NULL)
1401                 tti->tti_transno = lustre_msg_get_transno(req->rq_reqmsg);
1402         else
1403                 /* From update replay, tti_transno should be set already */
1404                 LASSERT(tti->tti_transno != 0);
1405
1406         spin_lock(&tgt->lut_translock);
1407         if (th->th_result != 0) {
1408                 if (tti->tti_transno != 0) {
1409                         CERROR("%s: replay transno %llu failed: rc = %d\n",
1410                                tgt_name(tgt), tti->tti_transno, th->th_result);
1411                 }
1412         } else if (tti->tti_transno == 0) {
1413                 tti->tti_transno = ++tgt->lut_last_transno;
1414         } else {
1415                 /* should be replay */
1416                 if (tti->tti_transno > tgt->lut_last_transno)
1417                         tgt->lut_last_transno = tti->tti_transno;
1418         }
1419         spin_unlock(&tgt->lut_translock);
1420
1421         /** VBR: set new versions */
1422         if (th->th_result == 0 && obj != NULL) {
1423                 struct dt_object *dto = dt_object_locate(obj, th->th_dev);
1424                 dt_version_set(env, dto, tti->tti_transno, th);
1425         }
1426
1427         /* filling reply data */
1428         CDEBUG(D_INODE, "transno = %llu, last_committed = %llu\n",
1429                tti->tti_transno, tgt->lut_obd->obd_last_committed);
1430
1431         if (req != NULL) {
1432                 req->rq_transno = tti->tti_transno;
1433                 lustre_msg_set_transno(req->rq_repmsg, tti->tti_transno);
1434         }
1435
1436         /* if can't add callback, do sync write */
1437         th->th_sync |= !!tgt_last_commit_cb_add(th, tgt, exp, tti->tti_transno);
1438
1439         if (nolcd) {
1440                 /* store transno in the last_rcvd header */
1441                 spin_lock(&tgt->lut_translock);
1442                 if (tti->tti_transno > tgt->lut_lsd.lsd_last_transno) {
1443                         tgt->lut_lsd.lsd_last_transno = tti->tti_transno;
1444                         spin_unlock(&tgt->lut_translock);
1445                         /* Although current connection doesn't have slot
1446                          * in the last_rcvd, we still want to maintain
1447                          * the in-memory lsd_client_data structure in order to
1448                          * properly handle reply reconstruction. */
1449                         rc = tgt_server_data_write(env, tgt, th);
1450                 } else {
1451                         spin_unlock(&tgt->lut_translock);
1452                 }
1453         } else if (ted->ted_lr_off == 0) {
1454                 CERROR("%s: client idx %d has offset %lld\n",
1455                        tgt_name(tgt), ted->ted_lr_idx, ted->ted_lr_off);
1456                 RETURN(-EINVAL);
1457         }
1458
1459         /* Target that supports multiple reply data */
1460         if (tgt_is_multimodrpcs_client(exp)) {
1461                 return tgt_mk_reply_data(env, tgt, ted, req, opdata, th,
1462                                          !!(req != NULL), tti->tti_transno);
1463         }
1464
1465         /* Enough for update replay, let's return */
1466         if (req == NULL)
1467                 RETURN(rc);
1468
1469         mutex_lock(&ted->ted_lcd_lock);
1470         LASSERT(ergo(tti->tti_transno == 0, th->th_result != 0));
1471         if (lustre_msg_get_opc(req->rq_reqmsg) == MDS_CLOSE) {
1472                 transno_p = &ted->ted_lcd->lcd_last_close_transno;
1473                 ted->ted_lcd->lcd_last_close_xid = req->rq_xid;
1474                 ted->ted_lcd->lcd_last_close_result = th->th_result;
1475         } else {
1476                 /* VBR: save versions in last_rcvd for reconstruct. */
1477                 __u64 *pre_versions = lustre_msg_get_versions(req->rq_repmsg);
1478
1479                 if (pre_versions) {
1480                         ted->ted_lcd->lcd_pre_versions[0] = pre_versions[0];
1481                         ted->ted_lcd->lcd_pre_versions[1] = pre_versions[1];
1482                         ted->ted_lcd->lcd_pre_versions[2] = pre_versions[2];
1483                         ted->ted_lcd->lcd_pre_versions[3] = pre_versions[3];
1484                 }
1485                 transno_p = &ted->ted_lcd->lcd_last_transno;
1486                 ted->ted_lcd->lcd_last_xid = req->rq_xid;
1487                 ted->ted_lcd->lcd_last_result = th->th_result;
1488                 /* XXX: lcd_last_data is __u32 but intent_dispostion is __u64,
1489                  * see struct ldlm_reply->lock_policy_res1; */
1490                 ted->ted_lcd->lcd_last_data = opdata;
1491         }
1492
1493         /* Update transno in slot only if non-zero number, i.e. no errors */
1494         if (likely(tti->tti_transno != 0)) {
1495                 /* Don't overwrite bigger transaction number with lower one.
1496                  * That is not sign of problem in all cases, but in any case
1497                  * this value should be monotonically increased only. */
1498                 if (*transno_p > tti->tti_transno) {
1499                         if (!tgt->lut_no_reconstruct) {
1500                                 CERROR("%s: trying to overwrite bigger transno:"
1501                                        "on-disk: %llu, new: %llu replay: "
1502                                        "%d. See LU-617.\n", tgt_name(tgt),
1503                                        *transno_p, tti->tti_transno,
1504                                        req_is_replay(req));
1505                                 if (req_is_replay(req)) {
1506                                         spin_lock(&req->rq_export->exp_lock);
1507                                         req->rq_export->exp_vbr_failed = 1;
1508                                         spin_unlock(&req->rq_export->exp_lock);
1509                                 }
1510                                 mutex_unlock(&ted->ted_lcd_lock);
1511                                 RETURN(req_is_replay(req) ? -EOVERFLOW : 0);
1512                         }
1513                 } else {
1514                         *transno_p = tti->tti_transno;
1515                 }
1516         }
1517
1518         if (!nolcd) {
1519                 tti->tti_off = ted->ted_lr_off;
1520                 if (CFS_FAIL_CHECK(OBD_FAIL_TGT_RCVD_EIO))
1521                         rc = -EIO;
1522                 else
1523                         rc = tgt_client_data_write(env, tgt, ted->ted_lcd,
1524                                                    &tti->tti_off, th);
1525                 if (rc < 0) {
1526                         mutex_unlock(&ted->ted_lcd_lock);
1527                         RETURN(rc);
1528                 }
1529         }
1530         mutex_unlock(&ted->ted_lcd_lock);
1531         RETURN(rc);
1532 }
1533
1534 /*
1535  * last_rcvd update for echo client simulation.
1536  * It updates last_rcvd client slot and version of object in
1537  * simple way but with all locks to simulate all drawbacks
1538  */
1539 static int tgt_last_rcvd_update_echo(const struct lu_env *env,
1540                                      struct lu_target *tgt,
1541                                      struct dt_object *obj,
1542                                      struct thandle *th,
1543                                      struct obd_export *exp)
1544 {
1545         struct tgt_thread_info  *tti = tgt_th_info(env);
1546         struct tg_export_data   *ted = &exp->exp_target_data;
1547         int                      rc = 0;
1548
1549         ENTRY;
1550
1551         tti->tti_transno = 0;
1552
1553         spin_lock(&tgt->lut_translock);
1554         if (th->th_result == 0)
1555                 tti->tti_transno = ++tgt->lut_last_transno;
1556         spin_unlock(&tgt->lut_translock);
1557
1558         /** VBR: set new versions */
1559         if (th->th_result == 0 && obj != NULL)
1560                 dt_version_set(env, obj, tti->tti_transno, th);
1561
1562         /* if can't add callback, do sync write */
1563         th->th_sync |= !!tgt_last_commit_cb_add(th, tgt, exp,
1564                                                 tti->tti_transno);
1565
1566         LASSERT(ted->ted_lr_off > 0);
1567
1568         mutex_lock(&ted->ted_lcd_lock);
1569         LASSERT(ergo(tti->tti_transno == 0, th->th_result != 0));
1570         ted->ted_lcd->lcd_last_transno = tti->tti_transno;
1571         ted->ted_lcd->lcd_last_result = th->th_result;
1572
1573         tti->tti_off = ted->ted_lr_off;
1574         rc = tgt_client_data_write(env, tgt, ted->ted_lcd, &tti->tti_off, th);
1575         mutex_unlock(&ted->ted_lcd_lock);
1576         RETURN(rc);
1577 }
1578
1579 static int tgt_clients_data_init(const struct lu_env *env,
1580                                  struct lu_target *tgt,
1581                                  unsigned long last_size)
1582 {
1583         struct obd_device       *obd = tgt->lut_obd;
1584         struct lr_server_data   *lsd = &tgt->lut_lsd;
1585         struct lsd_client_data  *lcd = NULL;
1586         struct tg_export_data   *ted;
1587         int                      cl_idx;
1588         int                      rc = 0;
1589         loff_t                   off = lsd->lsd_client_start;
1590         __u32                    generation = 0;
1591         struct cfs_hash         *hash = NULL;
1592
1593         ENTRY;
1594
1595         if (tgt->lut_bottom->dd_rdonly)
1596                 RETURN(0);
1597
1598         BUILD_BUG_ON(offsetof(struct lsd_client_data, lcd_padding) +
1599                      sizeof(lcd->lcd_padding) != LR_CLIENT_SIZE);
1600
1601         OBD_ALLOC_PTR(lcd);
1602         if (lcd == NULL)
1603                 RETURN(-ENOMEM);
1604
1605         hash = cfs_hash_getref(tgt->lut_obd->obd_gen_hash);
1606         if (hash == NULL)
1607                 GOTO(err_out, rc = -ENODEV);
1608
1609         for (cl_idx = 0; off < last_size; cl_idx++) {
1610                 struct obd_export       *exp;
1611                 __u64                    last_transno;
1612
1613                 /* Don't assume off is incremented properly by
1614                  * read_record(), in case sizeof(*lcd)
1615                  * isn't the same as fsd->lsd_client_size.  */
1616                 off = lsd->lsd_client_start + cl_idx * lsd->lsd_client_size;
1617                 rc = tgt_client_data_read(env, tgt, lcd, &off, cl_idx);
1618                 if (rc) {
1619                         CERROR("%s: error reading last_rcvd %s idx %d off "
1620                                "%llu: rc = %d\n", tgt_name(tgt), LAST_RCVD,
1621                                cl_idx, off, rc);
1622                         rc = 0;
1623                         break; /* read error shouldn't cause startup to fail */
1624                 }
1625
1626                 if (lcd->lcd_uuid[0] == '\0') {
1627                         CDEBUG(D_INFO, "skipping zeroed client at offset %d\n",
1628                                cl_idx);
1629                         continue;
1630                 }
1631
1632                 last_transno = lcd_last_transno(lcd);
1633
1634                 /* These exports are cleaned up by disconnect, so they
1635                  * need to be set up like real exports as connect does.
1636                  */
1637                 CDEBUG(D_HA, "RCVRNG CLIENT uuid: %s idx: %d lr: %llu"
1638                        " srv lr: %llu lx: %llu gen %u\n", lcd->lcd_uuid,
1639                        cl_idx, last_transno, lsd->lsd_last_transno,
1640                        lcd_last_xid(lcd), lcd->lcd_generation);
1641
1642                 exp = class_new_export(obd, (struct obd_uuid *)lcd->lcd_uuid);
1643                 if (IS_ERR(exp)) {
1644                         if (PTR_ERR(exp) == -EALREADY) {
1645                                 /* export already exists, zero out this one */
1646                                 CERROR("%s: Duplicate export %s!\n",
1647                                        tgt_name(tgt), lcd->lcd_uuid);
1648                                 continue;
1649                         }
1650                         GOTO(err_out, rc = PTR_ERR(exp));
1651                 }
1652
1653                 ted = &exp->exp_target_data;
1654                 *ted->ted_lcd = *lcd;
1655
1656                 rc = tgt_client_add(env, exp, cl_idx);
1657                 LASSERTF(rc == 0, "rc = %d\n", rc); /* can't fail existing */
1658                 /* VBR: set export last committed version */
1659                 exp->exp_last_committed = last_transno;
1660                 spin_lock(&exp->exp_lock);
1661                 exp->exp_connecting = 0;
1662                 exp->exp_in_recovery = 0;
1663                 spin_unlock(&exp->exp_lock);
1664                 atomic_inc(&obd->obd_max_recoverable_clients);
1665
1666                 if (tgt_is_multimodrpcs_record(tgt, lcd)) {
1667                         atomic_inc(&tgt->lut_num_clients);
1668
1669                         /* compute the highest valid client generation */
1670                         generation = max(generation, lcd->lcd_generation);
1671                         /* fill client_generation <-> export hash table */
1672                         rc = cfs_hash_add_unique(hash, &lcd->lcd_generation,
1673                                                  &exp->exp_gen_hash);
1674                         if (rc != 0) {
1675                                 CERROR("%s: duplicate export for client "
1676                                        "generation %u\n",
1677                                        tgt_name(tgt), lcd->lcd_generation);
1678                                 class_export_put(exp);
1679                                 GOTO(err_out, rc);
1680                         }
1681                 }
1682
1683                 class_export_put(exp);
1684
1685                 rc = rev_import_init(exp);
1686                 if (rc != 0) {
1687                         class_unlink_export(exp);
1688                         GOTO(err_out, rc);
1689                 }
1690
1691                 /* Need to check last_rcvd even for duplicated exports. */
1692                 CDEBUG(D_OTHER, "client at idx %d has last_transno = %llu\n",
1693                        cl_idx, last_transno);
1694
1695                 spin_lock(&tgt->lut_translock);
1696                 tgt->lut_last_transno = max(last_transno,
1697                                             tgt->lut_last_transno);
1698                 spin_unlock(&tgt->lut_translock);
1699         }
1700
1701         /* record highest valid client generation */
1702         atomic_set(&tgt->lut_client_generation, generation);
1703
1704 err_out:
1705         if (hash != NULL)
1706                 cfs_hash_putref(hash);
1707         OBD_FREE_PTR(lcd);
1708         RETURN(rc);
1709 }
1710
1711 struct server_compat_data {
1712         __u32 rocompat;
1713         __u32 incompat;
1714         __u32 rocinit;
1715         __u32 incinit;
1716 };
1717
1718 static struct server_compat_data tgt_scd[] = {
1719         [LDD_F_SV_TYPE_MDT] = {
1720                 .rocompat = OBD_ROCOMPAT_LOVOBJID,
1721                 .incompat = OBD_INCOMPAT_MDT | OBD_INCOMPAT_COMMON_LR |
1722                             OBD_INCOMPAT_FID | OBD_INCOMPAT_IAM_DIR |
1723                             OBD_INCOMPAT_LMM_VER | OBD_INCOMPAT_MULTI_OI |
1724                             OBD_INCOMPAT_MULTI_RPCS,
1725                 .rocinit = OBD_ROCOMPAT_LOVOBJID,
1726                 .incinit = OBD_INCOMPAT_MDT | OBD_INCOMPAT_COMMON_LR |
1727                            OBD_INCOMPAT_MULTI_OI,
1728         },
1729         [LDD_F_SV_TYPE_OST] = {
1730                 .rocompat = OBD_ROCOMPAT_IDX_IN_IDIF,
1731                 .incompat = OBD_INCOMPAT_OST | OBD_INCOMPAT_COMMON_LR |
1732                             OBD_INCOMPAT_FID,
1733                 .rocinit = OBD_ROCOMPAT_IDX_IN_IDIF,
1734                 .incinit = OBD_INCOMPAT_OST | OBD_INCOMPAT_COMMON_LR,
1735         }
1736 };
1737
1738 int tgt_server_data_init(const struct lu_env *env, struct lu_target *tgt)
1739 {
1740         struct tgt_thread_info          *tti = tgt_th_info(env);
1741         struct lr_server_data           *lsd = &tgt->lut_lsd;
1742         unsigned long                    last_rcvd_size;
1743         __u32                            index;
1744         int                              rc, type;
1745
1746         rc = dt_attr_get(env, tgt->lut_last_rcvd, &tti->tti_attr);
1747         if (rc)
1748                 RETURN(rc);
1749
1750         last_rcvd_size = (unsigned long)tti->tti_attr.la_size;
1751
1752         /* ensure padding in the struct is the correct size */
1753         BUILD_BUG_ON(offsetof(struct lr_server_data, lsd_padding) +
1754                      sizeof(lsd->lsd_padding) != LR_SERVER_SIZE);
1755
1756         rc = server_name2index(tgt_name(tgt), &index, NULL);
1757         if (rc < 0) {
1758                 CERROR("%s: Can not get index from name: rc = %d\n",
1759                        tgt_name(tgt), rc);
1760                 RETURN(rc);
1761         }
1762         /* server_name2index() returns type */
1763         type = rc;
1764         if (type != LDD_F_SV_TYPE_MDT && type != LDD_F_SV_TYPE_OST) {
1765                 CERROR("%s: unknown target type %x\n", tgt_name(tgt), type);
1766                 RETURN(-EINVAL);
1767         }
1768
1769         /* last_rcvd on OST doesn't provide reconstruct support because there
1770          * may be up to 8 in-flight write requests per single slot in
1771          * last_rcvd client data
1772          */
1773         tgt->lut_no_reconstruct = (type == LDD_F_SV_TYPE_OST);
1774
1775         if (last_rcvd_size == 0) {
1776                 LCONSOLE_WARN("%s: new disk, initializing\n", tgt_name(tgt));
1777
1778                 memcpy(lsd->lsd_uuid, tgt->lut_obd->obd_uuid.uuid,
1779                        sizeof(lsd->lsd_uuid));
1780                 lsd->lsd_last_transno = 0;
1781                 lsd->lsd_mount_count = 0;
1782                 lsd->lsd_server_size = LR_SERVER_SIZE;
1783                 lsd->lsd_client_start = LR_CLIENT_START;
1784                 lsd->lsd_client_size = LR_CLIENT_SIZE;
1785                 lsd->lsd_subdir_count = OBJ_SUBDIR_COUNT;
1786                 lsd->lsd_osd_index = index;
1787                 lsd->lsd_feature_rocompat = tgt_scd[type].rocinit;
1788                 lsd->lsd_feature_incompat = tgt_scd[type].incinit;
1789         } else {
1790                 rc = tgt_server_data_read(env, tgt);
1791                 if (rc) {
1792                         CERROR("%s: error reading LAST_RCVD: rc= %d\n",
1793                                tgt_name(tgt), rc);
1794                         RETURN(rc);
1795                 }
1796                 if (strcmp(lsd->lsd_uuid, tgt->lut_obd->obd_uuid.uuid)) {
1797                         if (tgt->lut_bottom->dd_rdonly) {
1798                                 /* Such difference may be caused by mounting
1799                                  * up snapshot with new fsname under rd_only
1800                                  * mode. But even if it was NOT, it will not
1801                                  * damage the system because of "rd_only". */
1802                                 memcpy(lsd->lsd_uuid,
1803                                        tgt->lut_obd->obd_uuid.uuid,
1804                                        sizeof(lsd->lsd_uuid));
1805                         } else {
1806                                 LCONSOLE_ERROR_MSG(0x157, "Trying to start "
1807                                                    "OBD %s using the wrong "
1808                                                    "disk %s. Were the /dev/ "
1809                                                    "assignments rearranged?\n",
1810                                                    tgt->lut_obd->obd_uuid.uuid,
1811                                                    lsd->lsd_uuid);
1812                                 RETURN(-EINVAL);
1813                         }
1814                 }
1815
1816                 if (lsd->lsd_osd_index != index) {
1817                         LCONSOLE_ERROR_MSG(0x157,
1818                                            "%s: index %d in last rcvd is different with the index %d in config log, It might be disk corruption!\n",
1819                                            tgt_name(tgt),
1820                                            lsd->lsd_osd_index, index);
1821                         RETURN(-EINVAL);
1822                 }
1823         }
1824
1825         if (lsd->lsd_feature_incompat & ~tgt_scd[type].incompat) {
1826                 CERROR("%s: unsupported incompat filesystem feature(s) %x\n",
1827                        tgt_name(tgt),
1828                        lsd->lsd_feature_incompat & ~tgt_scd[type].incompat);
1829                 RETURN(-EINVAL);
1830         }
1831
1832         if (type == LDD_F_SV_TYPE_MDT)
1833                 lsd->lsd_feature_incompat |= OBD_INCOMPAT_FID;
1834
1835         if (lsd->lsd_feature_rocompat & ~tgt_scd[type].rocompat) {
1836                 CERROR("%s: unsupported read-only filesystem feature(s) %x\n",
1837                        tgt_name(tgt),
1838                        lsd->lsd_feature_rocompat & ~tgt_scd[type].rocompat);
1839                 RETURN(-EINVAL);
1840         }
1841         /** Interop: evict all clients at first boot with 1.8 last_rcvd */
1842         if (type == LDD_F_SV_TYPE_MDT &&
1843             !(lsd->lsd_feature_compat & OBD_COMPAT_20)) {
1844                 if (last_rcvd_size > lsd->lsd_client_start) {
1845                         LCONSOLE_WARN("%s: mounting at first time on 1.8 FS, "
1846                                       "remove all clients for interop needs\n",
1847                                       tgt_name(tgt));
1848                         rc = tgt_truncate_last_rcvd(env, tgt,
1849                                                     lsd->lsd_client_start);
1850                         if (rc)
1851                                 RETURN(rc);
1852                         last_rcvd_size = lsd->lsd_client_start;
1853                 }
1854                 /** set 2.0 flag to upgrade/downgrade between 1.8 and 2.0 */
1855                 lsd->lsd_feature_compat |= OBD_COMPAT_20;
1856         }
1857
1858         spin_lock(&tgt->lut_translock);
1859         tgt->lut_last_transno = lsd->lsd_last_transno;
1860         spin_unlock(&tgt->lut_translock);
1861
1862         lsd->lsd_mount_count++;
1863
1864         CDEBUG(D_INODE, "=======,=BEGIN DUMPING LAST_RCVD========\n");
1865         CDEBUG(D_INODE, "%s: server last_transno: %llu\n",
1866                tgt_name(tgt), tgt->lut_last_transno);
1867         CDEBUG(D_INODE, "%s: server mount_count: %llu\n",
1868                tgt_name(tgt), lsd->lsd_mount_count);
1869         CDEBUG(D_INODE, "%s: server data size: %u\n",
1870                tgt_name(tgt), lsd->lsd_server_size);
1871         CDEBUG(D_INODE, "%s: per-client data start: %u\n",
1872                tgt_name(tgt), lsd->lsd_client_start);
1873         CDEBUG(D_INODE, "%s: per-client data size: %u\n",
1874                tgt_name(tgt), lsd->lsd_client_size);
1875         CDEBUG(D_INODE, "%s: last_rcvd size: %lu\n",
1876                tgt_name(tgt), last_rcvd_size);
1877         CDEBUG(D_INODE, "%s: server subdir_count: %u\n",
1878                tgt_name(tgt), lsd->lsd_subdir_count);
1879         CDEBUG(D_INODE, "%s: last_rcvd clients: %lu\n", tgt_name(tgt),
1880                last_rcvd_size <= lsd->lsd_client_start ? 0 :
1881                (last_rcvd_size - lsd->lsd_client_start) /
1882                 lsd->lsd_client_size);
1883         CDEBUG(D_INODE, "========END DUMPING LAST_RCVD========\n");
1884
1885         if (lsd->lsd_server_size == 0 || lsd->lsd_client_start == 0 ||
1886             lsd->lsd_client_size == 0) {
1887                 CERROR("%s: bad last_rcvd contents!\n", tgt_name(tgt));
1888                 RETURN(-EINVAL);
1889         }
1890
1891         if (!tgt->lut_obd->obd_replayable)
1892                 CWARN("%s: recovery support OFF\n", tgt_name(tgt));
1893
1894         rc = tgt_clients_data_init(env, tgt, last_rcvd_size);
1895         if (rc < 0)
1896                 GOTO(err_client, rc);
1897
1898         spin_lock(&tgt->lut_translock);
1899         /* obd_last_committed is used for compatibility
1900          * with other lustre recovery code */
1901         tgt->lut_obd->obd_last_committed = tgt->lut_last_transno;
1902         spin_unlock(&tgt->lut_translock);
1903
1904         obd2obt(tgt->lut_obd)->obt_mount_count = lsd->lsd_mount_count;
1905         obd2obt(tgt->lut_obd)->obt_instance = (__u32)lsd->lsd_mount_count;
1906
1907         /* save it, so mount count and last_transno is current */
1908         rc = tgt_server_data_update(env, tgt, 0);
1909         if (rc < 0)
1910                 GOTO(err_client, rc);
1911
1912         RETURN(0);
1913
1914 err_client:
1915         class_disconnect_exports(tgt->lut_obd);
1916         return rc;
1917 }
1918
1919 /* add credits for last_rcvd update */
1920 int tgt_txn_start_cb(const struct lu_env *env, struct thandle *th,
1921                      void *cookie)
1922 {
1923         struct lu_target        *tgt = cookie;
1924         struct tgt_session_info *tsi;
1925         struct tgt_thread_info  *tti = tgt_th_info(env);
1926         struct dt_object        *dto;
1927         int                      rc;
1928
1929         /* For readonly case, the caller should have got failure
1930          * when start the transaction. If the logic comes here,
1931          * there must be something wrong. */
1932         if (unlikely(tgt->lut_bottom->dd_rdonly)) {
1933                 dump_stack();
1934                 LBUG();
1935         }
1936
1937         /* if there is no session, then this transaction is not result of
1938          * request processing but some local operation */
1939         if (env->le_ses == NULL)
1940                 return 0;
1941
1942         LASSERT(tgt->lut_last_rcvd);
1943         tsi = tgt_ses_info(env);
1944         /* OFD may start transaction without export assigned */
1945         if (tsi->tsi_exp == NULL)
1946                 return 0;
1947
1948         if (tgt_is_multimodrpcs_client(tsi->tsi_exp)) {
1949                 /*
1950                  * Use maximum possible file offset for declaration to ensure
1951                  * ZFS will reserve enough credits for a write anywhere in this
1952                  * file, since we don't know where in the file the write will be
1953                  * because a replay slot has not been assigned.  This should be
1954                  * replaced by dmu_tx_hold_append() when available.
1955                  */
1956                 tti->tti_buf.lb_buf = NULL;
1957                 tti->tti_buf.lb_len = sizeof(struct lsd_reply_data);
1958                 dto = dt_object_locate(tgt->lut_reply_data, th->th_dev);
1959                 rc = dt_declare_record_write(env, dto, &tti->tti_buf, -1, th);
1960                 if (rc)
1961                         return rc;
1962         } else {
1963                 dto = dt_object_locate(tgt->lut_last_rcvd, th->th_dev);
1964                 tti_buf_lcd(tti);
1965                 tti->tti_off = tsi->tsi_exp->exp_target_data.ted_lr_off;
1966                 rc = dt_declare_record_write(env, dto, &tti->tti_buf,
1967                                              tti->tti_off, th);
1968                 if (rc)
1969                         return rc;
1970         }
1971
1972         if (tsi->tsi_vbr_obj != NULL &&
1973             !lu_object_remote(&tsi->tsi_vbr_obj->do_lu)) {
1974                 dto = dt_object_locate(tsi->tsi_vbr_obj, th->th_dev);
1975                 rc = dt_declare_version_set(env, dto, th);
1976         }
1977
1978         return rc;
1979 }
1980
1981 /* Update last_rcvd records with latests transaction data */
1982 int tgt_txn_stop_cb(const struct lu_env *env, struct thandle *th,
1983                     void *cookie)
1984 {
1985         struct lu_target        *tgt = cookie;
1986         struct tgt_session_info *tsi;
1987         struct tgt_thread_info  *tti = tgt_th_info(env);
1988         struct dt_object        *obj = NULL;
1989         int                      rc;
1990         bool                     echo_client;
1991
1992         if (env->le_ses == NULL)
1993                 return 0;
1994
1995         tsi = tgt_ses_info(env);
1996         /* OFD may start transaction without export assigned */
1997         if (tsi->tsi_exp == NULL)
1998                 return 0;
1999
2000         echo_client = (tgt_ses_req(tsi) == NULL && tsi->tsi_xid == 0);
2001
2002         if (tsi->tsi_has_trans && !echo_client) {
2003                 if (!tsi->tsi_mult_trans) {
2004                         CDEBUG(D_HA, "More than one transaction %llu\n",
2005                                tti->tti_transno);
2006                         /**
2007                          * if RPC handler sees unexpected multiple last_rcvd
2008                          * updates with transno, then it is better to return
2009                          * the latest transaction number to the client.
2010                          * In that case replay may fail if part of operation
2011                          * was committed and can't be re-applied easily. But
2012                          * that is better than report the first transno, in
2013                          * which case partially committed operation would be
2014                          * considered as finished so never replayed causing
2015                          * data loss.
2016                          */
2017                 }
2018                 /* we need new transno to be assigned */
2019                 tti->tti_transno = 0;
2020         }
2021
2022         if (!th->th_result)
2023                 tsi->tsi_has_trans++;
2024
2025         if (tsi->tsi_vbr_obj != NULL &&
2026             !lu_object_remote(&tsi->tsi_vbr_obj->do_lu)) {
2027                 obj = tsi->tsi_vbr_obj;
2028         }
2029
2030         if (unlikely(echo_client)) /* echo client special case */
2031                 rc = tgt_last_rcvd_update_echo(env, tgt, obj, th,
2032                                                tsi->tsi_exp);
2033         else
2034                 rc = tgt_last_rcvd_update(env, tgt, obj, tsi->tsi_opdata, th,
2035                                           tgt_ses_req(tsi));
2036         return rc;
2037 }
2038
2039 int tgt_reply_data_init(const struct lu_env *env, struct lu_target *tgt)
2040 {
2041         struct tgt_thread_info  *tti = tgt_th_info(env);
2042         struct lsd_reply_data   *lrd = &tti->tti_lrd;
2043         unsigned long            reply_data_size;
2044         int                      rc;
2045         struct lsd_reply_header *lrh = NULL;
2046         struct tg_reply_data    *trd = NULL;
2047         int                      idx;
2048         loff_t                   off;
2049         struct cfs_hash         *hash = NULL;
2050         struct obd_export       *exp;
2051         struct tg_export_data   *ted;
2052         int                      reply_data_recovered = 0;
2053
2054         rc = dt_attr_get(env, tgt->lut_reply_data, &tti->tti_attr);
2055         if (rc)
2056                 GOTO(out, rc);
2057         reply_data_size = (unsigned long)tti->tti_attr.la_size;
2058
2059         OBD_ALLOC_PTR(lrh);
2060         if (lrh == NULL)
2061                 GOTO(out, rc = -ENOMEM);
2062
2063         if (reply_data_size == 0) {
2064                 CDEBUG(D_INFO, "%s: new reply_data file, initializing\n",
2065                        tgt_name(tgt));
2066                 lrh->lrh_magic = LRH_MAGIC;
2067                 lrh->lrh_header_size = sizeof(struct lsd_reply_header);
2068                 lrh->lrh_reply_size = sizeof(struct lsd_reply_data);
2069                 rc = tgt_reply_header_write(env, tgt, lrh);
2070                 if (rc) {
2071                         CERROR("%s: error writing %s: rc = %d\n",
2072                                tgt_name(tgt), REPLY_DATA, rc);
2073                         GOTO(out, rc);
2074                 }
2075         } else {
2076                 rc = tgt_reply_header_read(env, tgt, lrh);
2077                 if (rc) {
2078                         CERROR("%s: error reading %s: rc = %d\n",
2079                                tgt_name(tgt), REPLY_DATA, rc);
2080                         GOTO(out, rc);
2081                 }
2082                 if (lrh->lrh_magic != LRH_MAGIC ||
2083                     lrh->lrh_header_size != sizeof(struct lsd_reply_header) ||
2084                     lrh->lrh_reply_size != sizeof(struct lsd_reply_data)) {
2085                         CERROR("%s: invalid header in %s\n",
2086                                tgt_name(tgt), REPLY_DATA);
2087                         GOTO(out, rc = -EINVAL);
2088                 }
2089
2090                 hash = cfs_hash_getref(tgt->lut_obd->obd_gen_hash);
2091                 if (hash == NULL)
2092                         GOTO(out, rc = -ENODEV);
2093
2094                 OBD_ALLOC_PTR(trd);
2095                 if (trd == NULL)
2096                         GOTO(out, rc = -ENOMEM);
2097
2098                 /* Load reply_data from disk */
2099                 for (idx = 0, off = sizeof(struct lsd_reply_header);
2100                      off < reply_data_size;
2101                      idx++, off += sizeof(struct lsd_reply_data)) {
2102                         rc = tgt_reply_data_read(env, tgt, lrd, off);
2103                         if (rc) {
2104                                 CERROR("%s: error reading %s: rc = %d\n",
2105                                        tgt_name(tgt), REPLY_DATA, rc);
2106                                 GOTO(out, rc);
2107                         }
2108
2109                         exp = cfs_hash_lookup(hash, &lrd->lrd_client_gen);
2110                         if (exp == NULL) {
2111                                 /* old reply data from a disconnected client */
2112                                 continue;
2113                         }
2114                         ted = &exp->exp_target_data;
2115                         mutex_lock(&ted->ted_lcd_lock);
2116
2117                         /* create in-memory reply_data and link it to
2118                          * target export's reply list */
2119                         rc = tgt_set_reply_slot(tgt, idx);
2120                         if (rc != 0) {
2121                                 mutex_unlock(&ted->ted_lcd_lock);
2122                                 GOTO(out, rc);
2123                         }
2124                         trd->trd_reply = *lrd;
2125                         trd->trd_pre_versions[0] = 0;
2126                         trd->trd_pre_versions[1] = 0;
2127                         trd->trd_pre_versions[2] = 0;
2128                         trd->trd_pre_versions[3] = 0;
2129                         trd->trd_index = idx;
2130                         trd->trd_tag = 0;
2131                         fid_zero(&trd->trd_object);
2132                         list_add(&trd->trd_list, &ted->ted_reply_list);
2133                         ted->ted_reply_cnt++;
2134                         if (ted->ted_reply_cnt > ted->ted_reply_max)
2135                                 ted->ted_reply_max = ted->ted_reply_cnt;
2136
2137                         CDEBUG(D_HA, "%s: restore reply %p: xid %llu, "
2138                                "transno %llu, client gen %u, slot idx %d\n",
2139                                tgt_name(tgt), trd, lrd->lrd_xid,
2140                                lrd->lrd_transno, lrd->lrd_client_gen,
2141                                trd->trd_index);
2142
2143                         /* update export last committed transation */
2144                         exp->exp_last_committed = max(exp->exp_last_committed,
2145                                                       lrd->lrd_transno);
2146                         /* Update lcd_last_transno as well for check in
2147                          * tgt_release_reply_data() or the latest client
2148                          * transno can be lost.
2149                          */
2150                         ted->ted_lcd->lcd_last_transno =
2151                                 max(ted->ted_lcd->lcd_last_transno,
2152                                     exp->exp_last_committed);
2153
2154                         mutex_unlock(&ted->ted_lcd_lock);
2155                         class_export_put(exp);
2156
2157                         /* update target last committed transaction */
2158                         spin_lock(&tgt->lut_translock);
2159                         tgt->lut_last_transno = max(tgt->lut_last_transno,
2160                                                     lrd->lrd_transno);
2161                         spin_unlock(&tgt->lut_translock);
2162
2163                         reply_data_recovered++;
2164
2165                         OBD_ALLOC_PTR(trd);
2166                         if (trd == NULL)
2167                                 GOTO(out, rc = -ENOMEM);
2168                 }
2169                 CDEBUG(D_INFO, "%s: %d reply data have been recovered\n",
2170                        tgt_name(tgt), reply_data_recovered);
2171         }
2172
2173         spin_lock(&tgt->lut_translock);
2174         /* obd_last_committed is used for compatibility
2175          * with other lustre recovery code */
2176         tgt->lut_obd->obd_last_committed = tgt->lut_last_transno;
2177         spin_unlock(&tgt->lut_translock);
2178
2179         rc = 0;
2180
2181 out:
2182         if (hash != NULL)
2183                 cfs_hash_putref(hash);
2184         if (trd != NULL)
2185                 OBD_FREE_PTR(trd);
2186         if (lrh != NULL)
2187                 OBD_FREE_PTR(lrh);
2188         return rc;
2189 }
2190
2191 static int tgt_check_lookup_req(struct ptlrpc_request *req, int lookup,
2192                                 struct tg_reply_data *trd)
2193 {
2194         struct tg_export_data *ted = &req->rq_export->exp_target_data;
2195         struct lu_target *lut = class_exp2tgt(req->rq_export);
2196         __u16 tag = lustre_msg_get_tag(req->rq_reqmsg);
2197         int rc = 0;
2198         struct tg_reply_data *reply;
2199         bool check_increasing;
2200
2201         if (tag == 0)
2202                 return 0;
2203
2204         check_increasing = tgt_is_increasing_xid_client(req->rq_export) &&
2205                            !(lustre_msg_get_flags(req->rq_reqmsg) & MSG_REPLAY);
2206         if (!lookup && !check_increasing)
2207                 return 0;
2208
2209         list_for_each_entry(reply, &ted->ted_reply_list, trd_list) {
2210                 if (lookup && reply->trd_reply.lrd_xid == req->rq_xid) {
2211                         rc = 1;
2212                         if (trd != NULL)
2213                                 *trd = *reply;
2214                         break;
2215                 } else if (check_increasing && reply->trd_tag == tag &&
2216                            reply->trd_reply.lrd_xid > req->rq_xid) {
2217                         rc = -EPROTO;
2218                         CERROR("%s: busy tag=%u req_xid=%llu, trd=%p: xid=%llu transno=%llu client_gen=%u slot_idx=%d: rc = %d\n",
2219                                tgt_name(lut), tag, req->rq_xid, trd,
2220                                reply->trd_reply.lrd_xid,
2221                                reply->trd_reply.lrd_transno,
2222                                reply->trd_reply.lrd_client_gen,
2223                                reply->trd_index, rc);
2224                         break;
2225                 }
2226         }
2227
2228         return rc;
2229 }
2230
2231 /* Look for a reply data matching specified request @req
2232  * A copy is returned in @trd if the pointer is not NULL
2233  */
2234 int tgt_lookup_reply(struct ptlrpc_request *req, struct tg_reply_data *trd)
2235 {
2236         struct tg_export_data *ted = &req->rq_export->exp_target_data;
2237         int found = 0;
2238         bool not_replay = !(lustre_msg_get_flags(req->rq_reqmsg) & MSG_REPLAY);
2239
2240         mutex_lock(&ted->ted_lcd_lock);
2241         if (not_replay && req->rq_xid <= req->rq_export->exp_last_xid) {
2242                 /* A check for the last_xid is needed here in case there is
2243                  * no reply data is left in the list. It may happen if another
2244                  * RPC on another slot increased the last_xid between our
2245                  * process_req_last_xid & tgt_lookup_reply calls */
2246                 found = -EPROTO;
2247         } else {
2248                 found = tgt_check_lookup_req(req, 1, trd);
2249         }
2250         mutex_unlock(&ted->ted_lcd_lock);
2251
2252         CDEBUG(D_TRACE, "%s: lookup reply xid %llu, found %d last_xid %llu\n",
2253                tgt_name(class_exp2tgt(req->rq_export)), req->rq_xid, found,
2254                req->rq_export->exp_last_xid);
2255
2256         return found;
2257 }
2258 EXPORT_SYMBOL(tgt_lookup_reply);
2259
2260 int tgt_handle_received_xid(struct obd_export *exp, __u64 rcvd_xid)
2261 {
2262         struct tg_export_data   *ted = &exp->exp_target_data;
2263         struct lu_target        *lut = class_exp2tgt(exp);
2264         struct tg_reply_data    *trd, *tmp;
2265
2266
2267         list_for_each_entry_safe(trd, tmp, &ted->ted_reply_list, trd_list) {
2268                 if (trd->trd_reply.lrd_xid > rcvd_xid)
2269                         continue;
2270                 ted->ted_release_xid++;
2271                 tgt_release_reply_data(lut, ted, trd);
2272         }
2273
2274         return 0;
2275 }
2276
2277 int tgt_handle_tag(struct ptlrpc_request *req)
2278 {
2279         return tgt_check_lookup_req(req, 0, NULL);
2280 }
2281