lustre/lmv/lmv_intent.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * Copyright (C) 2002, 2003 Cluster File Systems, Inc.
   5  *
   6  *   This file is part of Lustre, http://www.lustre.org.
   7  *
   8  *   Lustre is free software; you can redistribute it and/or
   9  *   modify it under the terms of version 2 of the GNU General Public
  10  *   License as published by the Free Software Foundation.
  11  *
  12  *   Lustre is distributed in the hope that it will be useful,
  13  *   but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  *   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  *   GNU General Public License for more details.
  16  *
  17  *   You should have received a copy of the GNU General Public License
  18  *   along with Lustre; if not, write to the Free Software
  19  *   Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
  20  */
  21
  22 #ifndef EXPORT_SYMTAB
  23 # define EXPORT_SYMTAB
  24 #endif
  25 #define DEBUG_SUBSYSTEM S_LMV
  26 #ifdef __KERNEL__
  27 #include <linux/slab.h>
  28 #include <linux/module.h>
  29 #include <linux/init.h>
  30 #include <linux/slab.h>
  31 #include <linux/pagemap.h>
  32 #include <asm/div64.h>
  33 #include <linux/seq_file.h>
  34 #else
  35 #include <liblustre.h>
  36 #endif
  37
  38 #include <linux/obd_support.h>
  39 #include <linux/lustre_lib.h>
  40 #include <linux/lustre_net.h>
  41 #include <linux/lustre_idl.h>
  42 #include <linux/lustre_dlm.h>
  43 #include <linux/lustre_mds.h>
  44 #include <linux/obd_class.h>
  45 #include <linux/obd_ost.h>
  46 #include <linux/lprocfs_status.h>
  47 #include <linux/lustre_fsfilt.h>
  48 #include <linux/obd_lmv.h>
  49 #include "lmv_internal.h"
  50
  51
  52 static inline void lmv_drop_intent_lock(struct lookup_intent *it)
  53 {
  54         if (it->d.lustre.it_lock_mode != 0)
  55                 ldlm_lock_decref((void *)&it->d.lustre.it_lock_handle,
  56                                  it->d.lustre.it_lock_mode);
  57 }
  58
  59 int lmv_handle_remote_inode(struct obd_export *exp, struct ll_uctxt *uctxt,
  60                             void *lmm, int lmmsize,
  61                             struct lookup_intent *it, int flags,
  62                             struct ptlrpc_request **reqp,
  63                             ldlm_blocking_callback cb_blocking)
  64 {
  65         struct obd_device *obd = exp->exp_obd;
  66         struct lmv_obd *lmv = &obd->u.lmv;
  67         struct mds_body *body = NULL;
  68         int rc = 0;
  69         ENTRY;
  70
  71         body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
  72         LASSERT(body != NULL);
  73
  74         if (body->valid & OBD_MD_MDS) {
  75                 /* oh, MDS reports that this is remote inode case
  76                  * i.e. we have to ask for real attrs on another MDS */
  77                 struct ptlrpc_request *req;
  78                 struct ll_fid nfid;
  79                 struct lustre_handle plock;
  80                 int pmode;
  81
  82                 if (it->it_op == IT_LOOKUP) {
  83                         /* unfortunately, we have to lie to MDC/MDS to
  84                          * retrieve attributes llite needs */
  85                         it->it_op = IT_GETATTR;
  86                 }
  87
  88                 /* we got LOOKUP lock, but we really need attrs */
  89                 pmode = it->d.lustre.it_lock_mode;
  90                 if (pmode) {
  91                         memcpy(&plock, &it->d.lustre.it_lock_handle,
  92                                         sizeof(plock));
  93                         it->d.lustre.it_lock_mode = 0;
  94                 }
  95
  96                 nfid = body->fid1;
  97                 it->d.lustre.it_disposition &= ~DISP_ENQ_COMPLETE;
  98                 rc = md_intent_lock(lmv->tgts[nfid.mds].ltd_exp, uctxt, &nfid,
  99                                     NULL, 0, lmm, lmmsize, NULL, it, flags,
 100                                     &req, cb_blocking);
 101
 102                 /* llite needs LOOKUP lock to track dentry revocation in
 103                  * order to maintain dcache consistency. thus drop UPDATE
 104                  * lock here and put LOOKUP in request */
 105                 if (rc == 0) {
 106                         lmv_drop_intent_lock(it);
 107                         memcpy(&it->d.lustre.it_lock_handle, &plock,
 108                                         sizeof(plock));
 109                         it->d.lustre.it_lock_mode = pmode;
 110
 111                 } else if (pmode)
 112                         ldlm_lock_decref(&plock, pmode);
 113
 114                 ptlrpc_req_finished(*reqp);
 115                 *reqp = req;
 116         }
 117         RETURN(rc);
 118 }
 119
 120 int lmv_intent_open(struct obd_export *exp, struct ll_uctxt *uctxt,
 121                     struct ll_fid *pfid, const char *name, int len,
 122                     void *lmm, int lmmsize, struct ll_fid *cfid,
 123                     struct lookup_intent *it, int flags,
 124                     struct ptlrpc_request **reqp,
 125                     ldlm_blocking_callback cb_blocking)
 126 {
 127         struct obd_device *obd = exp->exp_obd;
 128         struct lmv_obd *lmv = &obd->u.lmv;
 129         struct mds_body *body = NULL;
 130         struct ll_fid rpfid = *pfid;
 131         struct lmv_obj *obj;
 132         struct mea *mea;
 133         int rc, mds;
 134         ENTRY;
 135
 136         /* IT_OPEN is intended to open (and create, possible) an object. Parent
 137          * (pfid) may be splitted dir */
 138
 139 repeat:
 140         mds = rpfid.mds;
 141         obj = lmv_grab_obj(obd, &rpfid);
 142         if (obj) {
 143                 /* directory is already splitted, so we have to forward
 144                  * request to the right MDS */
 145                 mds = raw_name2idx(obj->objcount, (char *)name, len);
 146                 CDEBUG(D_OTHER, "forward to MDS #%u\n", mds);
 147                 rpfid = obj->objs[mds].fid;
 148                 lmv_put_obj(obj);
 149         }
 150
 151         rc = md_intent_lock(lmv->tgts[mds].ltd_exp, uctxt, &rpfid, name,
 152                             len, lmm, lmmsize, cfid, it, flags, reqp,
 153                             cb_blocking);
 154         if (rc == -ERESTART) {
 155                 /* directory got splitted. time to update local object
 156                  * and repeat the request with proper MDS */
 157                 LASSERT(fid_equal(pfid, &rpfid));
 158                 rc = lmv_get_mea_and_update_object(exp, &rpfid);
 159                 if (rc == 0) {
 160                         ptlrpc_req_finished(*reqp);
 161                         goto repeat;
 162                 }
 163         }
 164         if (rc != 0)
 165                 RETURN(rc);
 166
 167         /* okay, MDS has returned success. Probably name has been resolved in
 168          * remote inode */
 169         rc = lmv_handle_remote_inode(exp, uctxt, lmm, lmmsize, it,
 170                                      flags, reqp, cb_blocking);
 171         if (rc != 0) {
 172                 LASSERT(rc < 0);
 173                 RETURN(rc);
 174         }
 175
 176         /* caller may use attrs MDS returns on IT_OPEN lock request so, we have
 177          * to update them for splitted dir */
 178         body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 179         LASSERT(body != NULL);
 180
 181         cfid = &body->fid1;
 182         obj = lmv_grab_obj(obd, cfid);
 183         if (!obj && (mea = body_of_splitted_dir(*reqp, 1))) {
 184                 /* wow! this is splitted dir, we'd like to handle it */
 185                 obj = lmv_create_obj(exp, &body->fid1, mea);
 186                 if (IS_ERR(obj))
 187                         RETURN(PTR_ERR(obj));
 188         }
 189
 190         if (obj) {
 191                 /* this is splitted dir and we'd want to get attrs */
 192                 CDEBUG(D_OTHER, "attrs from slaves for %lu/%lu/%lu\n",
 193                        (unsigned long)cfid->mds, (unsigned long)cfid->id,
 194                        (unsigned long)cfid->generation);
 195                 rc = lmv_revalidate_slaves(exp, reqp, cfid,
 196                                            it, 1, cb_blocking);
 197         } else if (S_ISDIR(body->mode)) {
 198                 /*CWARN("hmmm, %lu/%lu/%lu has not lmv obj?!\n",
 199                                 (unsigned long) cfid->mds,
 200                                 (unsigned long) cfid->id,
 201                                 (unsigned long) cfid->generation);*/
 202         }
 203
 204         if (obj)
 205                 lmv_put_obj(obj);
 206
 207         RETURN(rc);
 208 }
 209
 210 int lmv_intent_getattr(struct obd_export *exp, struct ll_uctxt *uctxt,
 211                        struct ll_fid *pfid, const char *name, int len,
 212                        void *lmm, int lmmsize, struct ll_fid *cfid,
 213                        struct lookup_intent *it, int flags,
 214                        struct ptlrpc_request **reqp,
 215                        ldlm_blocking_callback cb_blocking)
 216 {
 217         struct obd_device *obd = exp->exp_obd;
 218         struct lmv_obd *lmv = &obd->u.lmv;
 219         struct mds_body *body = NULL;
 220         struct ll_fid rpfid = *pfid;
 221         struct lmv_obj *obj, *obj2;
 222         struct mea *mea;
 223         int rc = 0, mds;
 224         ENTRY;
 225
 226         if (cfid) {
 227                 /* caller wants to revalidate attrs of obj we have to revalidate
 228                  * slaves if requested object is splitted directory */
 229                 CDEBUG(D_OTHER, "revalidate attrs for %lu/%lu/%lu\n",
 230                        (unsigned long)cfid->mds, (unsigned long)cfid->id,
 231                        (unsigned long)cfid->generation);
 232                 mds = cfid->mds;
 233                 obj = lmv_grab_obj(obd, cfid);
 234                 if (obj) {
 235                         /* in fact, we need not this with current intent_lock(),
 236                          * but it may change some day */
 237                         rpfid = obj->objs[mds].fid;
 238                         lmv_put_obj(obj);
 239                 }
 240                 rc = md_intent_lock(lmv->tgts[mds].ltd_exp, uctxt, &rpfid, name,
 241                                     len, lmm, lmmsize, cfid, it, flags, reqp,
 242                                     cb_blocking);
 243                 if (obj && rc >= 0) {
 244                         /* this is splitted dir. In order to optimize things a
 245                          * bit, we consider obj valid updating missing parts.
 246
 247                          * FIXME: do we need to return any lock here? It would
 248                          * be fine if we don't. this means that nobody should
 249                          * use UPDATE lock to notify about object * removal */
 250                         CDEBUG(D_OTHER,
 251                                "revalidate slaves for %lu/%lu/%lu, rc %d\n",
 252                                (unsigned long)cfid->mds, (unsigned long)cfid->id,
 253                                (unsigned long)cfid->generation, rc);
 254
 255                         rc = lmv_revalidate_slaves(exp, reqp, cfid, it, rc,
 256                                                    cb_blocking);
 257                 }
 258
 259                 RETURN(rc);
 260         }
 261
 262         CDEBUG(D_OTHER, "INTENT getattr for %*s on %lu/%lu/%lu\n",
 263                len, name, (unsigned long)pfid->mds, (unsigned long)pfid->id,
 264                (unsigned long)pfid->generation);
 265
 266         mds = pfid->mds;
 267         obj = lmv_grab_obj(obd, pfid);
 268         if (obj && len) {
 269                 /* directory is already splitted. calculate mds */
 270                 mds = raw_name2idx(obj->objcount, (char *) name, len);
 271                 rpfid = obj->objs[mds].fid;
 272                 lmv_put_obj(obj);
 273
 274                 CDEBUG(D_OTHER, "forward to MDS #%u (slave %lu/%lu/%lu)\n",
 275                        mds, (unsigned long)rpfid.mds, (unsigned long)rpfid.id,
 276                        (unsigned long)rpfid.generation);
 277         }
 278
 279         rc = md_intent_lock(lmv->tgts[mds].ltd_exp, uctxt, &rpfid, name,
 280                             len, lmm, lmmsize, NULL, it, flags, reqp,
 281                             cb_blocking);
 282
 283         if (rc < 0)
 284                 RETURN(rc);
 285
 286         LASSERT(rc == 0);
 287
 288         /* okay, MDS has returned success. probably name has been
 289          * resolved in remote inode */
 290         rc = lmv_handle_remote_inode(exp, uctxt, lmm, lmmsize, it,
 291                                      flags, reqp, cb_blocking);
 292         if (rc < 0)
 293                 RETURN(rc);
 294
 295         body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 296         LASSERT(body != NULL);
 297
 298         cfid = &body->fid1;
 299         obj2 = lmv_grab_obj(obd, cfid);
 300
 301         if (!obj2 && (mea = body_of_splitted_dir(*reqp, 1))) {
 302                 /* wow! this is splitted dir, we'd like to handle it. */
 303                 body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 304                 LASSERT(body != NULL);
 305
 306                 obj2 = lmv_create_obj(exp, &body->fid1, mea);
 307                 if (IS_ERR(obj2))
 308                         RETURN(PTR_ERR(obj2));
 309         }
 310
 311         if (obj2) {
 312                 /* this is splitted dir and we'd want to get attrs */
 313                 CDEBUG(D_OTHER, "attrs from slaves for %lu/%lu/%lu, rc %d\n",
 314                        (unsigned long)cfid->mds, (unsigned long)cfid->id,
 315                        (unsigned long)cfid->generation, rc);
 316
 317                 rc = lmv_revalidate_slaves(exp, reqp, cfid, it, 1, cb_blocking);
 318                 lmv_put_obj(obj2);
 319         }
 320         RETURN(rc);
 321 }
 322
 323 void lmv_update_body_from_obj(struct mds_body *body, struct lmv_inode *obj)
 324 {
 325         /* update size */
 326         body->size += obj->size;
 327 /*        body->atime = obj->atime;
 328         body->ctime = obj->ctime;
 329         body->mtime = obj->mtime;
 330         body->nlink = obj->nlink;*/
 331 }
 332
 333 int lmv_lookup_slaves(struct obd_export *exp, struct ptlrpc_request **reqp)
 334 {
 335         struct obd_device *obd = exp->exp_obd;
 336         struct lmv_obd *lmv = &obd->u.lmv;
 337         struct mds_body *body = NULL;
 338         struct lustre_handle *lockh;
 339         struct ldlm_lock *lock;
 340         struct mds_body *body2;
 341         struct ll_uctxt uctxt;
 342         struct lmv_obj *obj;
 343         int i, rc = 0;
 344         ENTRY;
 345
 346         LASSERT(reqp);
 347         LASSERT(*reqp);
 348
 349         /* master is locked. we'd like to take locks on slaves and update
 350          * attributes to be returned from the slaves it's important that lookup
 351          * is called in two cases:
 352
 353          *  - for first time (dcache has no such a resolving yet).
 354          *  - ->d_revalidate() returned false.
 355
 356          * last case possible only if all the objs (master and all slaves aren't
 357          * valid */
 358
 359         body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 360         LASSERT(body != NULL);
 361
 362         obj = lmv_grab_obj(obd, &body->fid1);
 363         LASSERT(obj != NULL);
 364
 365         CDEBUG(D_OTHER, "lookup slaves for %lu/%lu/%lu\n",
 366                (unsigned long)body->fid1.mds,
 367                (unsigned long)body->fid1.id,
 368                (unsigned long)body->fid1.generation);
 369
 370         uctxt.gid1 = 0;
 371         uctxt.gid2 = 0;
 372
 373         lmv_lock_obj(obj);
 374
 375         for (i = 0; i < obj->objcount; i++) {
 376                 struct ll_fid fid = obj->objs[i].fid;
 377                 struct ptlrpc_request *req = NULL;
 378                 struct lookup_intent it;
 379
 380                 if (fid_equal(&fid, &obj->fid))
 381                         /* skip master obj */
 382                         continue;
 383
 384                 CDEBUG(D_OTHER, "lookup slave %lu/%lu/%lu\n",
 385                        (unsigned long)fid.mds, (unsigned long)fid.id,
 386                        (unsigned long)fid.generation);
 387
 388                 /* is obj valid? */
 389                 memset(&it, 0, sizeof(it));
 390                 it.it_op = IT_GETATTR;
 391                 rc = md_intent_lock(lmv->tgts[fid.mds].ltd_exp, &uctxt, &fid,
 392                                     NULL, 0, NULL, 0, &fid, &it, 0, &req,
 393                                     lmv_dirobj_blocking_ast);
 394
 395                 lockh = (struct lustre_handle *)&it.d.lustre.it_lock_handle;
 396                 if (rc > 0) {
 397                         /* nice, this slave is valid */
 398                         LASSERT(req == NULL);
 399                         CDEBUG(D_OTHER, "cached\n");
 400                         goto release_lock;
 401                 }
 402
 403                 if (rc < 0)
 404                         /* error during revalidation */
 405                         GOTO(cleanup, rc);
 406
 407                 /* rc == 0, this means we have no such a lock and can't think
 408                  * obj is still valid. lookup it again */
 409                 LASSERT(req == NULL);
 410                 req = NULL;
 411
 412                 memset(&it, 0, sizeof(it));
 413                 it.it_op = IT_GETATTR;
 414                 rc = md_intent_lock(lmv->tgts[fid.mds].ltd_exp, &uctxt, &fid,
 415                                     NULL, 0, NULL, 0, NULL, &it, 0, &req,
 416                                     lmv_dirobj_blocking_ast);
 417
 418                 lockh = (struct lustre_handle *) &it.d.lustre.it_lock_handle;
 419                 LASSERT(rc <= 0);
 420
 421                 if (rc < 0)
 422                         /* error during lookup */
 423                         GOTO(cleanup, rc);
 424
 425                 lock = ldlm_handle2lock(lockh);
 426                 LASSERT(lock);
 427
 428                 lock->l_ast_data = lmv_get_obj(obj);
 429
 430                 body2 = lustre_msg_buf(req->rq_repmsg, 1, sizeof(*body2));
 431                 LASSERT(body2);
 432
 433                 obj->objs[i].size = body2->size;
 434
 435                 CDEBUG(D_OTHER, "fresh: %lu\n",
 436                        (unsigned long)obj->objs[i].size);
 437
 438                 LDLM_LOCK_PUT(lock);
 439
 440                 if (req)
 441                         ptlrpc_req_finished(req);
 442 release_lock:
 443                 lmv_update_body_from_obj(body, obj->objs + i);
 444
 445                 if (it.d.lustre.it_lock_mode)
 446                         ldlm_lock_decref(lockh, it.d.lustre.it_lock_mode);
 447         }
 448 cleanup:
 449         lmv_unlock_obj(obj);
 450         lmv_put_obj(obj);
 451         RETURN(rc);
 452 }
 453
 454 int lmv_intent_lookup(struct obd_export *exp, struct ll_uctxt *uctxt,
 455                       struct ll_fid *pfid, const char *name, int len,
 456                       void *lmm, int lmmsize, struct ll_fid *cfid,
 457                       struct lookup_intent *it, int flags,
 458                       struct ptlrpc_request **reqp,
 459                       ldlm_blocking_callback cb_blocking)
 460 {
 461         struct obd_device *obd = exp->exp_obd;
 462         struct lmv_obd *lmv = &obd->u.lmv;
 463         struct mds_body *body = NULL;
 464         struct ll_fid rpfid = *pfid;
 465         struct lmv_obj *obj;
 466         struct mea *mea;
 467         int rc, mds;
 468         ENTRY;
 469
 470         /* IT_LOOKUP is intended to produce name -> fid resolving (let's call
 471          * this lookup below) or to confirm requested resolving is still valid
 472          * (let's call this revalidation) cfid != NULL specifies revalidation */
 473
 474         if (cfid) {
 475                 /* this is revalidation: we have to check is LOOKUP lock still
 476                  * valid for given fid. very important part is that we have to
 477                  * choose right mds because namespace is per mds */
 478                 rpfid = *pfid;
 479                 obj = lmv_grab_obj(obd, pfid);
 480                 if (obj) {
 481                         mds = raw_name2idx(obj->objcount, (char *) name, len);
 482                         rpfid = obj->objs[mds].fid;
 483                         lmv_put_obj(obj);
 484                 }
 485                 mds = rpfid.mds;
 486
 487                 CDEBUG(D_OTHER, "revalidate lookup for %lu/%lu/%lu to %d MDS\n",
 488                        (unsigned long)cfid->mds, (unsigned long)cfid->id,
 489                        (unsigned long)cfid->generation, mds);
 490
 491                 rc = md_intent_lock(lmv->tgts[mds].ltd_exp, uctxt, pfid, name,
 492                                     len, lmm, lmmsize, cfid, it, flags,
 493                                     reqp, cb_blocking);
 494                 RETURN(rc);
 495         }
 496
 497         mds = pfid->mds;
 498 repeat:
 499         /* this is lookup. during lookup we have to update all the attributes,
 500          * because returned values will be put in struct inode */
 501
 502         obj = lmv_grab_obj(obd, pfid);
 503         if (obj) {
 504                 if (len) {
 505                         /* directory is already splitted. calculate mds */
 506                         mds = raw_name2idx(obj->objcount, (char *)name, len);
 507                         rpfid = obj->objs[mds].fid;
 508                 }
 509                 lmv_put_obj(obj);
 510         }
 511
 512         rc = md_intent_lock(lmv->tgts[mds].ltd_exp, uctxt, &rpfid, name,
 513                             len, lmm, lmmsize, NULL, it, flags, reqp,
 514                             cb_blocking);
 515         if (rc > 0) {
 516                 /* very interesting. it seems object is still valid but for some
 517                  * reason llite calls lookup, not revalidate */
 518                 CWARN("lookup for %lu/%lu/%lu and data should be uptodate\n",
 519                       (unsigned long)rpfid.mds, (unsigned long)rpfid.id,
 520                       (unsigned long)rpfid.generation);
 521                 LASSERT(*reqp == NULL);
 522                 RETURN(rc);
 523         }
 524
 525         if (rc == 0 && *reqp == NULL) {
 526                 /* once again, we're asked for lookup, not revalidate */
 527                 CWARN("lookup for %lu/%lu/%lu and data should be uptodate\n",
 528                        (unsigned long)rpfid.mds, (unsigned long)rpfid.id,
 529                        (unsigned long)rpfid.generation);
 530                 RETURN(rc);
 531         }
 532
 533         if (rc == -ERESTART) {
 534                 /* directory got splitted since last update. this shouldn't be
 535                  * becasue splitting causes lock revocation, so revalidate had
 536                  * to fail and lookup on dir had to return mea */
 537                 CWARN("we haven't knew about directory splitting!\n");
 538                 LASSERT(obj == NULL);
 539
 540                 obj = lmv_create_obj(exp, &rpfid, NULL);
 541                 if (IS_ERR(obj))
 542                         RETURN(PTR_ERR(obj));
 543                 lmv_put_obj(obj);
 544                 goto repeat;
 545         }
 546
 547         if (rc < 0)
 548                 RETURN(rc);
 549
 550         /* okay, MDS has returned success. probably name has been resolved in
 551          * remote inode */
 552         rc = lmv_handle_remote_inode(exp, uctxt, lmm, lmmsize, it, flags,
 553                                      reqp, cb_blocking);
 554
 555         if (rc == 0 && (mea = body_of_splitted_dir(*reqp, 1))) {
 556                 /* wow! this is splitted dir, we'd like to handle it */
 557                 body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 558                 LASSERT(body != NULL);
 559
 560                 obj = lmv_grab_obj(obd, &body->fid1);
 561                 if (!obj) {
 562                         obj = lmv_create_obj(exp, &body->fid1, mea);
 563                         if (IS_ERR(obj))
 564                                 RETURN(PTR_ERR(obj));
 565                 }
 566                 lmv_put_obj(obj);
 567         }
 568
 569         RETURN(rc);
 570 }
 571
 572 int lmv_intent_lock(struct obd_export *exp, struct ll_uctxt *uctxt,
 573                     struct ll_fid *pfid, const char *name, int len,
 574                     void *lmm, int lmmsize, struct ll_fid *cfid,
 575                     struct lookup_intent *it, int flags,
 576                     struct ptlrpc_request **reqp,
 577                     ldlm_blocking_callback cb_blocking)
 578 {
 579         struct obd_device *obd = exp->exp_obd;
 580         int rc = 0;
 581         ENTRY;
 582
 583         LASSERT(it);
 584         LASSERT(pfid);
 585
 586         CDEBUG(D_OTHER, "INTENT LOCK '%s' for '%*s' on %lu/%lu -> %u\n",
 587                         LL_IT2STR(it), len, name, (unsigned long) pfid->id,
 588                         (unsigned long) pfid->generation, pfid->mds);
 589
 590         rc = lmv_check_connect(obd);
 591         if (rc)
 592                 RETURN(rc);
 593
 594         if (it->it_op == IT_LOOKUP)
 595                 rc = lmv_intent_lookup(exp, uctxt, pfid, name, len, lmm,
 596                                        lmmsize, cfid, it, flags, reqp,
 597                                        cb_blocking);
 598         else if (it->it_op & IT_OPEN)
 599                 rc = lmv_intent_open(exp, uctxt, pfid, name, len, lmm,
 600                                      lmmsize, cfid, it, flags, reqp,
 601                                      cb_blocking);
 602         else if (it->it_op == IT_GETATTR || it->it_op == IT_CHDIR)
 603                 rc = lmv_intent_getattr(exp, uctxt, pfid, name, len, lmm,
 604                                         lmmsize, cfid, it, flags, reqp,
 605                                         cb_blocking);
 606         else
 607                 LBUG();
 608         RETURN(rc);
 609 }
 610
 611 int lmv_revalidate_slaves(struct obd_export *exp, struct ptlrpc_request **reqp,
 612                           struct ll_fid *mfid, struct lookup_intent *oit,
 613                           int master_valid, ldlm_blocking_callback cb_blocking)
 614 {
 615         struct obd_device *obd = exp->exp_obd;
 616         struct ptlrpc_request *mreq = *reqp;
 617         struct lmv_obd *lmv = &obd->u.lmv;
 618         struct lustre_handle master_lockh;
 619         struct ldlm_lock *lock;
 620         unsigned long size = 0;
 621         struct mds_body *body;
 622         struct ll_uctxt uctxt;
 623         struct lmv_obj *obj;
 624         int master_lock_mode;
 625         int i, rc = 0;
 626         ENTRY;
 627
 628         /* we have to loop over the subobjects, check validity and update them
 629          * from MDSs if needed. it's very useful that we need not to update all
 630          * the fields. say, common fields (that are equal on all the subojects
 631          * need not to be update, another fields (i_size, for example) are
 632          * cached all the time */
 633         obj = lmv_grab_obj(obd, mfid);
 634         LASSERT(obj != NULL);
 635
 636         uctxt.gid1 = 0;
 637         uctxt.gid2 = 0;
 638         master_lock_mode = 0;
 639
 640         lmv_lock_obj(obj);
 641
 642         for (i = 0; i < obj->objcount; i++) {
 643                 struct ll_fid fid = obj->objs[i].fid;
 644                 struct lustre_handle *lockh = NULL;
 645                 struct ptlrpc_request *req = NULL;
 646                 ldlm_blocking_callback cb;
 647                 struct lookup_intent it;
 648                 int master = 0;
 649
 650                 CDEBUG(D_OTHER, "revalidate subobj %lu/%lu/%lu\n",
 651                        (unsigned long)fid.mds, (unsigned long)fid.id,
 652                        (unsigned long) fid.generation);
 653
 654                 memset(&it, 0, sizeof(it));
 655                 it.it_op = IT_GETATTR;
 656                 cb = lmv_dirobj_blocking_ast;
 657
 658                 if (fid_equal(&fid, &obj->fid)) {
 659                         if (master_valid) {
 660                                 /* lmv_intent_getattr() already checked
 661                                  * validness and took the lock */
 662                                 if (mreq) {
 663                                         /* it even got the reply refresh attrs
 664                                          * from that reply */
 665                                         body = lustre_msg_buf(mreq->rq_repmsg,
 666                                                               1, sizeof(*body));
 667                                         LASSERT(body != NULL);
 668                                         goto update;
 669                                 }
 670                                 /* take already cached attrs into account */
 671                                 CDEBUG(D_OTHER,
 672                                        "master is locked and cached\n");
 673                                 goto release_lock;
 674                         }
 675                         master = 1;
 676                         cb = cb_blocking;
 677                 }
 678
 679                 /* is obj valid? */
 680                 rc = md_intent_lock(lmv->tgts[fid.mds].ltd_exp, &uctxt, &fid,
 681                                     NULL, 0, NULL, 0, &fid, &it, 0, &req, cb);
 682                 lockh = (struct lustre_handle *) &it.d.lustre.it_lock_handle;
 683                 if (rc > 0) {
 684                         /* nice, this slave is valid */
 685                         LASSERT(req == NULL);
 686                         CDEBUG(D_OTHER, "cached\n");
 687                         goto release_lock;
 688                 }
 689
 690                 if (rc < 0)
 691                         /* error during revalidation */
 692                         GOTO(cleanup, rc);
 693
 694                 /* rc == 0, this means we have no such a lock and can't think
 695                  * obj is still valid. lookup it again */
 696                 LASSERT(req == NULL);
 697                 req = NULL;
 698
 699                 memset(&it, 0, sizeof(it));
 700                 it.it_op = IT_GETATTR;
 701                 rc = md_intent_lock(lmv->tgts[fid.mds].ltd_exp, &uctxt, &fid,
 702                                     NULL, 0, NULL, 0, NULL, &it, 0, &req, cb);
 703                 lockh = (struct lustre_handle *) &it.d.lustre.it_lock_handle;
 704                 LASSERT(rc <= 0);
 705
 706                 if (rc < 0)
 707                         /* error during lookup */
 708                         GOTO(cleanup, rc);
 709
 710                 if (master) {
 711                         LASSERT(master_valid == 0);
 712                         /* save lock on master to be returned to the caller */
 713                         CDEBUG(D_OTHER, "no lock on master yet\n");
 714                         memcpy(&master_lockh, lockh, sizeof(master_lockh));
 715                         master_lock_mode = it.d.lustre.it_lock_mode;
 716                         it.d.lustre.it_lock_mode = 0;
 717                 } else {
 718                         /* this is slave. we want to control it */
 719                         lock = ldlm_handle2lock(lockh);
 720                         LASSERT(lock);
 721                         lock->l_ast_data = lmv_get_obj(obj);
 722                         LDLM_LOCK_PUT(lock);
 723                 }
 724
 725                 if (*reqp == NULL) {
 726                         /* this is first reply, we'll use it to return
 727                          * updated data back to the caller */
 728                         LASSERT(req);
 729                         ptlrpc_request_addref(req);
 730                         *reqp = req;
 731
 732                 }
 733
 734                 body = lustre_msg_buf(req->rq_repmsg, 1, sizeof(*body));
 735                 LASSERT(body);
 736
 737 update:
 738                 obj->objs[i].size = body->size;
 739
 740                 CDEBUG(D_OTHER, "fresh: %lu\n",
 741                        (unsigned long)obj->objs[i].size);
 742
 743                 if (req)
 744                         ptlrpc_req_finished(req);
 745 release_lock:
 746                 size += obj->objs[i].size;
 747
 748                 if (it.d.lustre.it_lock_mode)
 749                         ldlm_lock_decref(lockh, it.d.lustre.it_lock_mode);
 750         }
 751
 752         if (*reqp) {
 753                 /* some attrs got refreshed, we have reply and it's time to put
 754                  * fresh attrs to it */
 755                 CDEBUG(D_OTHER, "return refreshed attrs: size = %lu\n",
 756                        (unsigned long)size);
 757
 758                 body = lustre_msg_buf((*reqp)->rq_repmsg, 1, sizeof(*body));
 759                 LASSERT(body);
 760
 761                 /* FIXME: what about other attributes? */
 762                 body->size = size;
 763
 764                 if (mreq == NULL) {
 765                         /* very important to maintain lli->mds the same because
 766                          * of revalidation. mreq == NULL means that caller has
 767                          * no reply and the only attr we can return is size */
 768                         body->valid = OBD_MD_FLSIZE;
 769                         body->mds = obj->fid.mds;
 770                 }
 771                 if (master_valid == 0) {
 772                         memcpy(&oit->d.lustre.it_lock_handle,
 773                                &master_lockh, sizeof(master_lockh));
 774                         oit->d.lustre.it_lock_mode = master_lock_mode;
 775                 }
 776                 rc = 0;
 777         } else {
 778                 /* it seems all the attrs are fresh and we did no request */
 779                 CDEBUG(D_OTHER, "all the attrs were fresh\n");
 780                 if (master_valid == 0)
 781                         oit->d.lustre.it_lock_mode = master_lock_mode;
 782                 rc = 1;
 783         }
 784 cleanup:
 785         lmv_unlock_obj(obj);
 786         lmv_put_obj(obj);
 787         RETURN(rc);
 788 }