drivers/staging/lustre/lustre/lov/lov_object.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) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  24  * Use is subject to license terms.
  25  *
  26  * Copyright (c) 2011, 2015, Intel Corporation.
  27  */
  28 /*
  29  * This file is part of Lustre, http://www.lustre.org/
  30  * Lustre is a trademark of Sun Microsystems, Inc.
  31  *
  32  * Implementation of cl_object for LOV layer.
  33  *
  34  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  35  *   Author: Jinshan Xiong <jinshan.xiong@whamcloud.com>
  36  */
  37
  38 #define DEBUG_SUBSYSTEM S_LOV
  39
  40 #include "lov_cl_internal.h"
  41
  42 /** \addtogroup lov
  43  *  @{
  44  */
  45
  46 /*****************************************************************************
  47  *
  48  * Layout operations.
  49  *
  50  */
  51
  52 struct lov_layout_operations {
  53         int (*llo_init)(const struct lu_env *env, struct lov_device *dev,
  54                         struct lov_object *lov,
  55                         const struct cl_object_conf *conf,
  56                         union lov_layout_state *state);
  57         int (*llo_delete)(const struct lu_env *env, struct lov_object *lov,
  58                           union lov_layout_state *state);
  59         void (*llo_fini)(const struct lu_env *env, struct lov_object *lov,
  60                          union lov_layout_state *state);
  61         void (*llo_install)(const struct lu_env *env, struct lov_object *lov,
  62                             union lov_layout_state *state);
  63         int  (*llo_print)(const struct lu_env *env, void *cookie,
  64                           lu_printer_t p, const struct lu_object *o);
  65         int  (*llo_page_init)(const struct lu_env *env, struct cl_object *obj,
  66                               struct cl_page *page, pgoff_t index);
  67         int  (*llo_lock_init)(const struct lu_env *env,
  68                               struct cl_object *obj, struct cl_lock *lock,
  69                               const struct cl_io *io);
  70         int  (*llo_io_init)(const struct lu_env *env,
  71                             struct cl_object *obj, struct cl_io *io);
  72         int  (*llo_getattr)(const struct lu_env *env, struct cl_object *obj,
  73                             struct cl_attr *attr);
  74 };
  75
  76 static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov);
  77
  78 void lov_lsm_put(struct cl_object *unused, struct lov_stripe_md *lsm)
  79 {
  80         if (lsm)
  81                 lov_free_memmd(&lsm);
  82 }
  83 EXPORT_SYMBOL(lov_lsm_put);
  84
  85 /*****************************************************************************
  86  *
  87  * Lov object layout operations.
  88  *
  89  */
  90
  91 static void lov_install_empty(const struct lu_env *env,
  92                               struct lov_object *lov,
  93                               union  lov_layout_state *state)
  94 {
  95         /*
  96          * File without objects.
  97          */
  98 }
  99
 100 static int lov_init_empty(const struct lu_env *env,
 101                           struct lov_device *dev, struct lov_object *lov,
 102                           const struct cl_object_conf *conf,
 103                           union  lov_layout_state *state)
 104 {
 105         return 0;
 106 }
 107
 108 static void lov_install_raid0(const struct lu_env *env,
 109                               struct lov_object *lov,
 110                               union  lov_layout_state *state)
 111 {
 112 }
 113
 114 static struct cl_object *lov_sub_find(const struct lu_env *env,
 115                                       struct cl_device *dev,
 116                                       const struct lu_fid *fid,
 117                                       const struct cl_object_conf *conf)
 118 {
 119         struct lu_object *o;
 120
 121         o = lu_object_find_at(env, cl2lu_dev(dev), fid, &conf->coc_lu);
 122         LASSERT(ergo(!IS_ERR(o), o->lo_dev->ld_type == &lovsub_device_type));
 123         return lu2cl(o);
 124 }
 125
 126 static int lov_init_sub(const struct lu_env *env, struct lov_object *lov,
 127                         struct cl_object *stripe, struct lov_layout_raid0 *r0,
 128                         int idx)
 129 {
 130         struct cl_object_header *hdr;
 131         struct cl_object_header *subhdr;
 132         struct cl_object_header *parent;
 133         struct lov_oinfo        *oinfo;
 134         int result;
 135
 136         if (OBD_FAIL_CHECK(OBD_FAIL_LOV_INIT)) {
 137                 /* For sanity:test_206.
 138                  * Do not leave the object in cache to avoid accessing
 139                  * freed memory. This is because osc_object is referring to
 140                  * lov_oinfo of lsm_stripe_data which will be freed due to
 141                  * this failure.
 142                  */
 143                 cl_object_kill(env, stripe);
 144                 cl_object_put(env, stripe);
 145                 return -EIO;
 146         }
 147
 148         hdr    = cl_object_header(lov2cl(lov));
 149         subhdr = cl_object_header(stripe);
 150
 151         oinfo = lov->lo_lsm->lsm_oinfo[idx];
 152         CDEBUG(D_INODE, DFID"@%p[%d] -> "DFID"@%p: ostid: "DOSTID
 153                " idx: %d gen: %d\n",
 154                PFID(&subhdr->coh_lu.loh_fid), subhdr, idx,
 155                PFID(&hdr->coh_lu.loh_fid), hdr, POSTID(&oinfo->loi_oi),
 156                oinfo->loi_ost_idx, oinfo->loi_ost_gen);
 157
 158         /* reuse ->coh_attr_guard to protect coh_parent change */
 159         spin_lock(&subhdr->coh_attr_guard);
 160         parent = subhdr->coh_parent;
 161         if (!parent) {
 162                 subhdr->coh_parent = hdr;
 163                 spin_unlock(&subhdr->coh_attr_guard);
 164                 subhdr->coh_nesting = hdr->coh_nesting + 1;
 165                 lu_object_ref_add(&stripe->co_lu, "lov-parent", lov);
 166                 r0->lo_sub[idx] = cl2lovsub(stripe);
 167                 r0->lo_sub[idx]->lso_super = lov;
 168                 r0->lo_sub[idx]->lso_index = idx;
 169                 result = 0;
 170         } else {
 171                 struct lu_object  *old_obj;
 172                 struct lov_object *old_lov;
 173                 unsigned int mask = D_INODE;
 174
 175                 spin_unlock(&subhdr->coh_attr_guard);
 176                 old_obj = lu_object_locate(&parent->coh_lu, &lov_device_type);
 177                 LASSERT(old_obj);
 178                 old_lov = cl2lov(lu2cl(old_obj));
 179                 if (old_lov->lo_layout_invalid) {
 180                         /* the object's layout has already changed but isn't
 181                          * refreshed
 182                          */
 183                         lu_object_unhash(env, &stripe->co_lu);
 184                         result = -EAGAIN;
 185                 } else {
 186                         mask = D_ERROR;
 187                         result = -EIO;
 188                 }
 189
 190                 LU_OBJECT_DEBUG(mask, env, &stripe->co_lu,
 191                                 "stripe %d is already owned.", idx);
 192                 LU_OBJECT_DEBUG(mask, env, old_obj, "owned.");
 193                 LU_OBJECT_HEADER(mask, env, lov2lu(lov), "try to own.\n");
 194                 cl_object_put(env, stripe);
 195         }
 196         return result;
 197 }
 198
 199 static int lov_page_slice_fixup(struct lov_object *lov,
 200                                 struct cl_object *stripe)
 201 {
 202         struct cl_object_header *hdr = cl_object_header(&lov->lo_cl);
 203         struct cl_object *o;
 204
 205         if (!stripe)
 206                 return hdr->coh_page_bufsize - lov->lo_cl.co_slice_off -
 207                        cfs_size_round(sizeof(struct lov_page));
 208
 209         cl_object_for_each(o, stripe)
 210                 o->co_slice_off += hdr->coh_page_bufsize;
 211
 212         return cl_object_header(stripe)->coh_page_bufsize;
 213 }
 214
 215 static int lov_init_raid0(const struct lu_env *env,
 216                           struct lov_device *dev, struct lov_object *lov,
 217                           const struct cl_object_conf *conf,
 218                           union  lov_layout_state *state)
 219 {
 220         int result;
 221         int i;
 222
 223         struct cl_object        *stripe;
 224         struct lov_thread_info  *lti     = lov_env_info(env);
 225         struct cl_object_conf   *subconf = &lti->lti_stripe_conf;
 226         struct lov_stripe_md    *lsm     = conf->u.coc_md->lsm;
 227         struct lu_fid      *ofid    = &lti->lti_fid;
 228         struct lov_layout_raid0 *r0      = &state->raid0;
 229
 230         if (lsm->lsm_magic != LOV_MAGIC_V1 && lsm->lsm_magic != LOV_MAGIC_V3) {
 231                 dump_lsm(D_ERROR, lsm);
 232                 LASSERTF(0, "magic mismatch, expected %d/%d, actual %d.\n",
 233                          LOV_MAGIC_V1, LOV_MAGIC_V3, lsm->lsm_magic);
 234         }
 235
 236         LASSERT(!lov->lo_lsm);
 237         lov->lo_lsm = lsm_addref(lsm);
 238         lov->lo_layout_invalid = true;
 239         r0->lo_nr  = lsm->lsm_stripe_count;
 240         LASSERT(r0->lo_nr <= lov_targets_nr(dev));
 241
 242         r0->lo_sub = libcfs_kvzalloc(r0->lo_nr * sizeof(r0->lo_sub[0]),
 243                                      GFP_NOFS);
 244         if (r0->lo_sub) {
 245                 int psz = 0;
 246
 247                 result = 0;
 248                 subconf->coc_inode = conf->coc_inode;
 249                 spin_lock_init(&r0->lo_sub_lock);
 250                 /*
 251                  * Create stripe cl_objects.
 252                  */
 253                 for (i = 0; i < r0->lo_nr && result == 0; ++i) {
 254                         struct cl_device *subdev;
 255                         struct lov_oinfo *oinfo = lsm->lsm_oinfo[i];
 256                         int ost_idx = oinfo->loi_ost_idx;
 257
 258                         if (lov_oinfo_is_dummy(oinfo))
 259                                 continue;
 260
 261                         result = ostid_to_fid(ofid, &oinfo->loi_oi,
 262                                               oinfo->loi_ost_idx);
 263                         if (result != 0)
 264                                 goto out;
 265
 266                         subdev = lovsub2cl_dev(dev->ld_target[ost_idx]);
 267                         subconf->u.coc_oinfo = oinfo;
 268                         LASSERTF(subdev, "not init ost %d\n", ost_idx);
 269                         /* In the function below, .hs_keycmp resolves to
 270                          * lu_obj_hop_keycmp()
 271                          */
 272                         /* coverity[overrun-buffer-val] */
 273                         stripe = lov_sub_find(env, subdev, ofid, subconf);
 274                         if (!IS_ERR(stripe)) {
 275                                 result = lov_init_sub(env, lov, stripe, r0, i);
 276                                 if (result == -EAGAIN) { /* try again */
 277                                         --i;
 278                                         result = 0;
 279                                         continue;
 280                                 }
 281                         } else {
 282                                 result = PTR_ERR(stripe);
 283                         }
 284
 285                         if (result == 0) {
 286                                 int sz = lov_page_slice_fixup(lov, stripe);
 287
 288                                 LASSERT(ergo(psz > 0, psz == sz));
 289                                 psz = sz;
 290                         }
 291                 }
 292                 if (result == 0)
 293                         cl_object_header(&lov->lo_cl)->coh_page_bufsize += psz;
 294         } else {
 295                 result = -ENOMEM;
 296         }
 297 out:
 298         return result;
 299 }
 300
 301 static int lov_init_released(const struct lu_env *env,
 302                              struct lov_device *dev, struct lov_object *lov,
 303                              const struct cl_object_conf *conf,
 304                              union  lov_layout_state *state)
 305 {
 306         struct lov_stripe_md *lsm = conf->u.coc_md->lsm;
 307
 308         LASSERT(lsm);
 309         LASSERT(lsm_is_released(lsm));
 310         LASSERT(!lov->lo_lsm);
 311
 312         lov->lo_lsm = lsm_addref(lsm);
 313         return 0;
 314 }
 315
 316 static int lov_delete_empty(const struct lu_env *env, struct lov_object *lov,
 317                             union lov_layout_state *state)
 318 {
 319         LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
 320
 321         lov_layout_wait(env, lov);
 322         return 0;
 323 }
 324
 325 static void lov_subobject_kill(const struct lu_env *env, struct lov_object *lov,
 326                                struct lovsub_object *los, int idx)
 327 {
 328         struct cl_object        *sub;
 329         struct lov_layout_raid0 *r0;
 330         struct lu_site    *site;
 331         struct lu_site_bkt_data *bkt;
 332         wait_queue_t      *waiter;
 333
 334         r0  = &lov->u.raid0;
 335         LASSERT(r0->lo_sub[idx] == los);
 336
 337         sub  = lovsub2cl(los);
 338         site = sub->co_lu.lo_dev->ld_site;
 339         bkt  = lu_site_bkt_from_fid(site, &sub->co_lu.lo_header->loh_fid);
 340
 341         cl_object_kill(env, sub);
 342         /* release a reference to the sub-object and ... */
 343         lu_object_ref_del(&sub->co_lu, "lov-parent", lov);
 344         cl_object_put(env, sub);
 345
 346         /* ... wait until it is actually destroyed---sub-object clears its
 347          * ->lo_sub[] slot in lovsub_object_fini()
 348          */
 349         if (r0->lo_sub[idx] == los) {
 350                 waiter = &lov_env_info(env)->lti_waiter;
 351                 init_waitqueue_entry(waiter, current);
 352                 add_wait_queue(&bkt->lsb_marche_funebre, waiter);
 353                 set_current_state(TASK_UNINTERRUPTIBLE);
 354                 while (1) {
 355                         /* this wait-queue is signaled at the end of
 356                          * lu_object_free().
 357                          */
 358                         set_current_state(TASK_UNINTERRUPTIBLE);
 359                         spin_lock(&r0->lo_sub_lock);
 360                         if (r0->lo_sub[idx] == los) {
 361                                 spin_unlock(&r0->lo_sub_lock);
 362                                 schedule();
 363                         } else {
 364                                 spin_unlock(&r0->lo_sub_lock);
 365                                 set_current_state(TASK_RUNNING);
 366                                 break;
 367                         }
 368                 }
 369                 remove_wait_queue(&bkt->lsb_marche_funebre, waiter);
 370         }
 371         LASSERT(!r0->lo_sub[idx]);
 372 }
 373
 374 static int lov_delete_raid0(const struct lu_env *env, struct lov_object *lov,
 375                             union lov_layout_state *state)
 376 {
 377         struct lov_layout_raid0 *r0 = &state->raid0;
 378         struct lov_stripe_md    *lsm = lov->lo_lsm;
 379         int i;
 380
 381         dump_lsm(D_INODE, lsm);
 382
 383         lov_layout_wait(env, lov);
 384         if (r0->lo_sub) {
 385                 for (i = 0; i < r0->lo_nr; ++i) {
 386                         struct lovsub_object *los = r0->lo_sub[i];
 387
 388                         if (los) {
 389                                 cl_object_prune(env, &los->lso_cl);
 390                                 /*
 391                                  * If top-level object is to be evicted from
 392                                  * the cache, so are its sub-objects.
 393                                  */
 394                                 lov_subobject_kill(env, lov, los, i);
 395                         }
 396                 }
 397         }
 398         return 0;
 399 }
 400
 401 static void lov_fini_empty(const struct lu_env *env, struct lov_object *lov,
 402                            union lov_layout_state *state)
 403 {
 404         LASSERT(lov->lo_type == LLT_EMPTY || lov->lo_type == LLT_RELEASED);
 405 }
 406
 407 static void lov_fini_raid0(const struct lu_env *env, struct lov_object *lov,
 408                            union lov_layout_state *state)
 409 {
 410         struct lov_layout_raid0 *r0 = &state->raid0;
 411
 412         if (r0->lo_sub) {
 413                 kvfree(r0->lo_sub);
 414                 r0->lo_sub = NULL;
 415         }
 416
 417         dump_lsm(D_INODE, lov->lo_lsm);
 418         lov_free_memmd(&lov->lo_lsm);
 419 }
 420
 421 static void lov_fini_released(const struct lu_env *env, struct lov_object *lov,
 422                               union lov_layout_state *state)
 423 {
 424         dump_lsm(D_INODE, lov->lo_lsm);
 425         lov_free_memmd(&lov->lo_lsm);
 426 }
 427
 428 static int lov_print_empty(const struct lu_env *env, void *cookie,
 429                            lu_printer_t p, const struct lu_object *o)
 430 {
 431         (*p)(env, cookie, "empty %d\n", lu2lov(o)->lo_layout_invalid);
 432         return 0;
 433 }
 434
 435 static int lov_print_raid0(const struct lu_env *env, void *cookie,
 436                            lu_printer_t p, const struct lu_object *o)
 437 {
 438         struct lov_object       *lov = lu2lov(o);
 439         struct lov_layout_raid0 *r0  = lov_r0(lov);
 440         struct lov_stripe_md    *lsm = lov->lo_lsm;
 441         int                      i;
 442
 443         (*p)(env, cookie, "stripes: %d, %s, lsm{%p 0x%08X %d %u %u}:\n",
 444              r0->lo_nr, lov->lo_layout_invalid ? "invalid" : "valid", lsm,
 445              lsm->lsm_magic, atomic_read(&lsm->lsm_refc),
 446              lsm->lsm_stripe_count, lsm->lsm_layout_gen);
 447         for (i = 0; i < r0->lo_nr; ++i) {
 448                 struct lu_object *sub;
 449
 450                 if (r0->lo_sub[i]) {
 451                         sub = lovsub2lu(r0->lo_sub[i]);
 452                         lu_object_print(env, cookie, p, sub);
 453                 } else {
 454                         (*p)(env, cookie, "sub %d absent\n", i);
 455                 }
 456         }
 457         return 0;
 458 }
 459
 460 static int lov_print_released(const struct lu_env *env, void *cookie,
 461                               lu_printer_t p, const struct lu_object *o)
 462 {
 463         struct lov_object       *lov = lu2lov(o);
 464         struct lov_stripe_md    *lsm = lov->lo_lsm;
 465
 466         (*p)(env, cookie,
 467              "released: %s, lsm{%p 0x%08X %d %u %u}:\n",
 468              lov->lo_layout_invalid ? "invalid" : "valid", lsm,
 469              lsm->lsm_magic, atomic_read(&lsm->lsm_refc),
 470              lsm->lsm_stripe_count, lsm->lsm_layout_gen);
 471         return 0;
 472 }
 473
 474 /**
 475  * Implements cl_object_operations::coo_attr_get() method for an object
 476  * without stripes (LLT_EMPTY layout type).
 477  *
 478  * The only attributes this layer is authoritative in this case is
 479  * cl_attr::cat_blocks---it's 0.
 480  */
 481 static int lov_attr_get_empty(const struct lu_env *env, struct cl_object *obj,
 482                               struct cl_attr *attr)
 483 {
 484         attr->cat_blocks = 0;
 485         return 0;
 486 }
 487
 488 static int lov_attr_get_raid0(const struct lu_env *env, struct cl_object *obj,
 489                               struct cl_attr *attr)
 490 {
 491         struct lov_object       *lov = cl2lov(obj);
 492         struct lov_layout_raid0 *r0 = lov_r0(lov);
 493         struct cl_attr          *lov_attr = &r0->lo_attr;
 494         int                      result = 0;
 495
 496         /* this is called w/o holding type guard mutex, so it must be inside
 497          * an on going IO otherwise lsm may be replaced.
 498          * LU-2117: it turns out there exists one exception. For mmaped files,
 499          * the lock of those files may be requested in the other file's IO
 500          * context, and this function is called in ccc_lock_state(), it will
 501          * hit this assertion.
 502          * Anyway, it's still okay to call attr_get w/o type guard as layout
 503          * can't go if locks exist.
 504          */
 505         /* LASSERT(atomic_read(&lsm->lsm_refc) > 1); */
 506
 507         if (!r0->lo_attr_valid) {
 508                 struct lov_stripe_md    *lsm = lov->lo_lsm;
 509                 struct ost_lvb    *lvb = &lov_env_info(env)->lti_lvb;
 510                 __u64               kms = 0;
 511
 512                 memset(lvb, 0, sizeof(*lvb));
 513                 /* XXX: timestamps can be negative by sanity:test_39m,
 514                  * how can it be?
 515                  */
 516                 lvb->lvb_atime = LLONG_MIN;
 517                 lvb->lvb_ctime = LLONG_MIN;
 518                 lvb->lvb_mtime = LLONG_MIN;
 519
 520                 /*
 521                  * XXX that should be replaced with a loop over sub-objects,
 522                  * doing cl_object_attr_get() on them. But for now, let's
 523                  * reuse old lov code.
 524                  */
 525
 526                 /*
 527                  * XXX take lsm spin-lock to keep lov_merge_lvb_kms()
 528                  * happy. It's not needed, because new code uses
 529                  * ->coh_attr_guard spin-lock to protect consistency of
 530                  * sub-object attributes.
 531                  */
 532                 lov_stripe_lock(lsm);
 533                 result = lov_merge_lvb_kms(lsm, lvb, &kms);
 534                 lov_stripe_unlock(lsm);
 535                 if (result == 0) {
 536                         cl_lvb2attr(lov_attr, lvb);
 537                         lov_attr->cat_kms = kms;
 538                         r0->lo_attr_valid = 1;
 539                 }
 540         }
 541         if (result == 0) { /* merge results */
 542                 attr->cat_blocks = lov_attr->cat_blocks;
 543                 attr->cat_size = lov_attr->cat_size;
 544                 attr->cat_kms = lov_attr->cat_kms;
 545                 if (attr->cat_atime < lov_attr->cat_atime)
 546                         attr->cat_atime = lov_attr->cat_atime;
 547                 if (attr->cat_ctime < lov_attr->cat_ctime)
 548                         attr->cat_ctime = lov_attr->cat_ctime;
 549                 if (attr->cat_mtime < lov_attr->cat_mtime)
 550                         attr->cat_mtime = lov_attr->cat_mtime;
 551         }
 552         return result;
 553 }
 554
 555 static const struct lov_layout_operations lov_dispatch[] = {
 556         [LLT_EMPTY] = {
 557                 .llo_init      = lov_init_empty,
 558                 .llo_delete    = lov_delete_empty,
 559                 .llo_fini      = lov_fini_empty,
 560                 .llo_install   = lov_install_empty,
 561                 .llo_print     = lov_print_empty,
 562                 .llo_page_init = lov_page_init_empty,
 563                 .llo_lock_init = lov_lock_init_empty,
 564                 .llo_io_init   = lov_io_init_empty,
 565                 .llo_getattr   = lov_attr_get_empty
 566         },
 567         [LLT_RAID0] = {
 568                 .llo_init      = lov_init_raid0,
 569                 .llo_delete    = lov_delete_raid0,
 570                 .llo_fini      = lov_fini_raid0,
 571                 .llo_install   = lov_install_raid0,
 572                 .llo_print     = lov_print_raid0,
 573                 .llo_page_init = lov_page_init_raid0,
 574                 .llo_lock_init = lov_lock_init_raid0,
 575                 .llo_io_init   = lov_io_init_raid0,
 576                 .llo_getattr   = lov_attr_get_raid0
 577         },
 578         [LLT_RELEASED] = {
 579                 .llo_init      = lov_init_released,
 580                 .llo_delete    = lov_delete_empty,
 581                 .llo_fini      = lov_fini_released,
 582                 .llo_install   = lov_install_empty,
 583                 .llo_print     = lov_print_released,
 584                 .llo_page_init = lov_page_init_empty,
 585                 .llo_lock_init = lov_lock_init_empty,
 586                 .llo_io_init   = lov_io_init_released,
 587                 .llo_getattr   = lov_attr_get_empty
 588         }
 589 };
 590
 591 /**
 592  * Performs a double-dispatch based on the layout type of an object.
 593  */
 594 #define LOV_2DISPATCH_NOLOCK(obj, op, ...)                            \
 595 ({                                                                    \
 596         struct lov_object                     *__obj = (obj);     \
 597         enum lov_layout_type                __llt;                \
 598                                                                         \
 599         __llt = __obj->lo_type;                                  \
 600         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
 601         lov_dispatch[__llt].op(__VA_ARGS__);                        \
 602 })
 603
 604 /**
 605  * Return lov_layout_type associated with a given lsm
 606  */
 607 static enum lov_layout_type lov_type(struct lov_stripe_md *lsm)
 608 {
 609         if (!lsm)
 610                 return LLT_EMPTY;
 611         if (lsm_is_released(lsm))
 612                 return LLT_RELEASED;
 613         return LLT_RAID0;
 614 }
 615
 616 static inline void lov_conf_freeze(struct lov_object *lov)
 617 {
 618         if (lov->lo_owner != current)
 619                 down_read(&lov->lo_type_guard);
 620 }
 621
 622 static inline void lov_conf_thaw(struct lov_object *lov)
 623 {
 624         if (lov->lo_owner != current)
 625                 up_read(&lov->lo_type_guard);
 626 }
 627
 628 #define LOV_2DISPATCH_MAYLOCK(obj, op, lock, ...)                      \
 629 ({                                                                    \
 630         struct lov_object                     *__obj = (obj);     \
 631         int                                  __lock = !!(lock);      \
 632         typeof(lov_dispatch[0].op(__VA_ARGS__)) __result;              \
 633                                                                         \
 634         if (__lock)                                                  \
 635                 lov_conf_freeze(__obj);                                 \
 636         __result = LOV_2DISPATCH_NOLOCK(obj, op, __VA_ARGS__);    \
 637         if (__lock)                                                  \
 638                 lov_conf_thaw(__obj);                                   \
 639         __result;                                                      \
 640 })
 641
 642 /**
 643  * Performs a locked double-dispatch based on the layout type of an object.
 644  */
 645 #define LOV_2DISPATCH(obj, op, ...)                  \
 646         LOV_2DISPATCH_MAYLOCK(obj, op, 1, __VA_ARGS__)
 647
 648 #define LOV_2DISPATCH_VOID(obj, op, ...)                                \
 649 do {                                                                \
 650         struct lov_object                     *__obj = (obj);     \
 651         enum lov_layout_type                __llt;                \
 652                                                                         \
 653         lov_conf_freeze(__obj);                                         \
 654         __llt = __obj->lo_type;                                  \
 655         LASSERT(0 <= __llt && __llt < ARRAY_SIZE(lov_dispatch));        \
 656         lov_dispatch[__llt].op(__VA_ARGS__);                        \
 657         lov_conf_thaw(__obj);                                           \
 658 } while (0)
 659
 660 static void lov_conf_lock(struct lov_object *lov)
 661 {
 662         LASSERT(lov->lo_owner != current);
 663         down_write(&lov->lo_type_guard);
 664         LASSERT(!lov->lo_owner);
 665         lov->lo_owner = current;
 666 }
 667
 668 static void lov_conf_unlock(struct lov_object *lov)
 669 {
 670         lov->lo_owner = NULL;
 671         up_write(&lov->lo_type_guard);
 672 }
 673
 674 static int lov_layout_wait(const struct lu_env *env, struct lov_object *lov)
 675 {
 676         struct l_wait_info lwi = { 0 };
 677
 678         while (atomic_read(&lov->lo_active_ios) > 0) {
 679                 CDEBUG(D_INODE, "file:" DFID " wait for active IO, now: %d.\n",
 680                        PFID(lu_object_fid(lov2lu(lov))),
 681                        atomic_read(&lov->lo_active_ios));
 682
 683                 l_wait_event(lov->lo_waitq,
 684                              atomic_read(&lov->lo_active_ios) == 0, &lwi);
 685         }
 686         return 0;
 687 }
 688
 689 static int lov_layout_change(const struct lu_env *unused,
 690                              struct lov_object *lov,
 691                              const struct cl_object_conf *conf)
 692 {
 693         int result;
 694         enum lov_layout_type llt = LLT_EMPTY;
 695         union lov_layout_state *state = &lov->u;
 696         const struct lov_layout_operations *old_ops;
 697         const struct lov_layout_operations *new_ops;
 698
 699         void *cookie;
 700         struct lu_env *env;
 701         int refcheck;
 702
 703         LASSERT(0 <= lov->lo_type && lov->lo_type < ARRAY_SIZE(lov_dispatch));
 704
 705         if (conf->u.coc_md)
 706                 llt = lov_type(conf->u.coc_md->lsm);
 707         LASSERT(0 <= llt && llt < ARRAY_SIZE(lov_dispatch));
 708
 709         cookie = cl_env_reenter();
 710         env = cl_env_get(&refcheck);
 711         if (IS_ERR(env)) {
 712                 cl_env_reexit(cookie);
 713                 return PTR_ERR(env);
 714         }
 715
 716         CDEBUG(D_INODE, DFID" from %s to %s\n",
 717                PFID(lu_object_fid(lov2lu(lov))),
 718                llt2str(lov->lo_type), llt2str(llt));
 719
 720         old_ops = &lov_dispatch[lov->lo_type];
 721         new_ops = &lov_dispatch[llt];
 722
 723         result = cl_object_prune(env, &lov->lo_cl);
 724         if (result != 0)
 725                 goto out;
 726
 727         result = old_ops->llo_delete(env, lov, &lov->u);
 728         if (result == 0) {
 729                 old_ops->llo_fini(env, lov, &lov->u);
 730
 731                 LASSERT(atomic_read(&lov->lo_active_ios) == 0);
 732
 733                 lov->lo_type = LLT_EMPTY;
 734                 /* page bufsize fixup */
 735                 cl_object_header(&lov->lo_cl)->coh_page_bufsize -=
 736                         lov_page_slice_fixup(lov, NULL);
 737
 738                 result = new_ops->llo_init(env,
 739                                         lu2lov_dev(lov->lo_cl.co_lu.lo_dev),
 740                                         lov, conf, state);
 741                 if (result == 0) {
 742                         new_ops->llo_install(env, lov, state);
 743                         lov->lo_type = llt;
 744                 } else {
 745                         new_ops->llo_delete(env, lov, state);
 746                         new_ops->llo_fini(env, lov, state);
 747                         /* this file becomes an EMPTY file. */
 748                 }
 749         }
 750
 751 out:
 752         cl_env_put(env, &refcheck);
 753         cl_env_reexit(cookie);
 754         return result;
 755 }
 756
 757 /*****************************************************************************
 758  *
 759  * Lov object operations.
 760  *
 761  */
 762 int lov_object_init(const struct lu_env *env, struct lu_object *obj,
 763                     const struct lu_object_conf *conf)
 764 {
 765         struct lov_device           *dev   = lu2lov_dev(obj->lo_dev);
 766         struct lov_object           *lov   = lu2lov(obj);
 767         const struct cl_object_conf  *cconf = lu2cl_conf(conf);
 768         union  lov_layout_state      *set   = &lov->u;
 769         const struct lov_layout_operations *ops;
 770         int result;
 771
 772         init_rwsem(&lov->lo_type_guard);
 773         atomic_set(&lov->lo_active_ios, 0);
 774         init_waitqueue_head(&lov->lo_waitq);
 775
 776         cl_object_page_init(lu2cl(obj), sizeof(struct lov_page));
 777
 778         /* no locking is necessary, as object is being created */
 779         lov->lo_type = lov_type(cconf->u.coc_md->lsm);
 780         ops = &lov_dispatch[lov->lo_type];
 781         result = ops->llo_init(env, dev, lov, cconf, set);
 782         if (result == 0)
 783                 ops->llo_install(env, lov, set);
 784         return result;
 785 }
 786
 787 static int lov_conf_set(const struct lu_env *env, struct cl_object *obj,
 788                         const struct cl_object_conf *conf)
 789 {
 790         struct lov_stripe_md    *lsm = NULL;
 791         struct lov_object       *lov = cl2lov(obj);
 792         int                      result = 0;
 793
 794         lov_conf_lock(lov);
 795         if (conf->coc_opc == OBJECT_CONF_INVALIDATE) {
 796                 lov->lo_layout_invalid = true;
 797                 result = 0;
 798                 goto out;
 799         }
 800
 801         if (conf->coc_opc == OBJECT_CONF_WAIT) {
 802                 if (lov->lo_layout_invalid &&
 803                     atomic_read(&lov->lo_active_ios) > 0) {
 804                         lov_conf_unlock(lov);
 805                         result = lov_layout_wait(env, lov);
 806                         lov_conf_lock(lov);
 807                 }
 808                 goto out;
 809         }
 810
 811         LASSERT(conf->coc_opc == OBJECT_CONF_SET);
 812
 813         if (conf->u.coc_md)
 814                 lsm = conf->u.coc_md->lsm;
 815         if ((!lsm && !lov->lo_lsm) ||
 816             ((lsm && lov->lo_lsm) &&
 817              (lov->lo_lsm->lsm_layout_gen == lsm->lsm_layout_gen) &&
 818              (lov->lo_lsm->lsm_pattern == lsm->lsm_pattern))) {
 819                 /* same version of layout */
 820                 lov->lo_layout_invalid = false;
 821                 result = 0;
 822                 goto out;
 823         }
 824
 825         /* will change layout - check if there still exists active IO. */
 826         if (atomic_read(&lov->lo_active_ios) > 0) {
 827                 lov->lo_layout_invalid = true;
 828                 result = -EBUSY;
 829                 goto out;
 830         }
 831
 832         result = lov_layout_change(env, lov, conf);
 833         lov->lo_layout_invalid = result != 0;
 834
 835 out:
 836         lov_conf_unlock(lov);
 837         CDEBUG(D_INODE, DFID" lo_layout_invalid=%d\n",
 838                PFID(lu_object_fid(lov2lu(lov))), lov->lo_layout_invalid);
 839         return result;
 840 }
 841
 842 static void lov_object_delete(const struct lu_env *env, struct lu_object *obj)
 843 {
 844         struct lov_object *lov = lu2lov(obj);
 845
 846         LOV_2DISPATCH_VOID(lov, llo_delete, env, lov, &lov->u);
 847 }
 848
 849 static void lov_object_free(const struct lu_env *env, struct lu_object *obj)
 850 {
 851         struct lov_object *lov = lu2lov(obj);
 852
 853         LOV_2DISPATCH_VOID(lov, llo_fini, env, lov, &lov->u);
 854         lu_object_fini(obj);
 855         kmem_cache_free(lov_object_kmem, lov);
 856 }
 857
 858 static int lov_object_print(const struct lu_env *env, void *cookie,
 859                             lu_printer_t p, const struct lu_object *o)
 860 {
 861         return LOV_2DISPATCH_NOLOCK(lu2lov(o), llo_print, env, cookie, p, o);
 862 }
 863
 864 int lov_page_init(const struct lu_env *env, struct cl_object *obj,
 865                   struct cl_page *page, pgoff_t index)
 866 {
 867         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_page_init, env, obj, page,
 868                                     index);
 869 }
 870
 871 /**
 872  * Implements cl_object_operations::clo_io_init() method for lov
 873  * layer. Dispatches to the appropriate layout io initialization method.
 874  */
 875 int lov_io_init(const struct lu_env *env, struct cl_object *obj,
 876                 struct cl_io *io)
 877 {
 878         CL_IO_SLICE_CLEAN(lov_env_io(env), lis_cl);
 879         return LOV_2DISPATCH_MAYLOCK(cl2lov(obj), llo_io_init,
 880                                      !io->ci_ignore_layout, env, obj, io);
 881 }
 882
 883 /**
 884  * An implementation of cl_object_operations::clo_attr_get() method for lov
 885  * layer. For raid0 layout this collects and merges attributes of all
 886  * sub-objects.
 887  */
 888 static int lov_attr_get(const struct lu_env *env, struct cl_object *obj,
 889                         struct cl_attr *attr)
 890 {
 891         /* do not take lock, as this function is called under a
 892          * spin-lock. Layout is protected from changing by ongoing IO.
 893          */
 894         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_getattr, env, obj, attr);
 895 }
 896
 897 static int lov_attr_update(const struct lu_env *env, struct cl_object *obj,
 898                            const struct cl_attr *attr, unsigned int valid)
 899 {
 900         /*
 901          * No dispatch is required here, as no layout implements this.
 902          */
 903         return 0;
 904 }
 905
 906 int lov_lock_init(const struct lu_env *env, struct cl_object *obj,
 907                   struct cl_lock *lock, const struct cl_io *io)
 908 {
 909         /* No need to lock because we've taken one refcount of layout.  */
 910         return LOV_2DISPATCH_NOLOCK(cl2lov(obj), llo_lock_init, env, obj, lock,
 911                                     io);
 912 }
 913
 914 static int lov_object_getstripe(const struct lu_env *env, struct cl_object *obj,
 915                                 struct lov_user_md __user *lum)
 916 {
 917         struct lov_object *lov = cl2lov(obj);
 918         struct lov_stripe_md *lsm;
 919         int rc = 0;
 920
 921         lsm = lov_lsm_addref(lov);
 922         if (!lsm)
 923                 return -ENODATA;
 924
 925         rc = lov_getstripe(cl2lov(obj), lsm, lum);
 926         lov_lsm_put(obj, lsm);
 927         return rc;
 928 }
 929
 930 static const struct cl_object_operations lov_ops = {
 931         .coo_page_init = lov_page_init,
 932         .coo_lock_init = lov_lock_init,
 933         .coo_io_init   = lov_io_init,
 934         .coo_attr_get  = lov_attr_get,
 935         .coo_attr_update = lov_attr_update,
 936         .coo_conf_set  = lov_conf_set,
 937         .coo_getstripe = lov_object_getstripe
 938 };
 939
 940 static const struct lu_object_operations lov_lu_obj_ops = {
 941         .loo_object_init      = lov_object_init,
 942         .loo_object_delete    = lov_object_delete,
 943         .loo_object_release   = NULL,
 944         .loo_object_free      = lov_object_free,
 945         .loo_object_print     = lov_object_print,
 946         .loo_object_invariant = NULL
 947 };
 948
 949 struct lu_object *lov_object_alloc(const struct lu_env *env,
 950                                    const struct lu_object_header *unused,
 951                                    struct lu_device *dev)
 952 {
 953         struct lov_object *lov;
 954         struct lu_object  *obj;
 955
 956         lov = kmem_cache_zalloc(lov_object_kmem, GFP_NOFS);
 957         if (lov) {
 958                 obj = lov2lu(lov);
 959                 lu_object_init(obj, NULL, dev);
 960                 lov->lo_cl.co_ops = &lov_ops;
 961                 lov->lo_type = -1; /* invalid, to catch uninitialized type */
 962                 /*
 963                  * object io operation vector (cl_object::co_iop) is installed
 964                  * later in lov_object_init(), as different vectors are used
 965                  * for object with different layouts.
 966                  */
 967                 obj->lo_ops = &lov_lu_obj_ops;
 968         } else {
 969                 obj = NULL;
 970         }
 971         return obj;
 972 }
 973
 974 struct lov_stripe_md *lov_lsm_addref(struct lov_object *lov)
 975 {
 976         struct lov_stripe_md *lsm = NULL;
 977
 978         lov_conf_freeze(lov);
 979         if (lov->lo_lsm) {
 980                 lsm = lsm_addref(lov->lo_lsm);
 981                 CDEBUG(D_INODE, "lsm %p addref %d/%d by %p.\n",
 982                        lsm, atomic_read(&lsm->lsm_refc),
 983                        lov->lo_layout_invalid, current);
 984         }
 985         lov_conf_thaw(lov);
 986         return lsm;
 987 }
 988
 989 struct lov_stripe_md *lov_lsm_get(struct cl_object *clobj)
 990 {
 991         struct lu_object *luobj;
 992         struct lov_stripe_md *lsm = NULL;
 993
 994         if (!clobj)
 995                 return NULL;
 996
 997         luobj = lu_object_locate(&cl_object_header(clobj)->coh_lu,
 998                                  &lov_device_type);
 999         if (luobj)
1000                 lsm = lov_lsm_addref(lu2lov(luobj));
1001         return lsm;
1002 }
1003 EXPORT_SYMBOL(lov_lsm_get);
1004
1005 int lov_read_and_clear_async_rc(struct cl_object *clob)
1006 {
1007         struct lu_object *luobj;
1008         int rc = 0;
1009
1010         luobj = lu_object_locate(&cl_object_header(clob)->coh_lu,
1011                                  &lov_device_type);
1012         if (luobj) {
1013                 struct lov_object *lov = lu2lov(luobj);
1014
1015                 lov_conf_freeze(lov);
1016                 switch (lov->lo_type) {
1017                 case LLT_RAID0: {
1018                         struct lov_stripe_md *lsm;
1019                         int i;
1020
1021                         lsm = lov->lo_lsm;
1022                         for (i = 0; i < lsm->lsm_stripe_count; i++) {
1023                                 struct lov_oinfo *loi = lsm->lsm_oinfo[i];
1024
1025                                 if (lov_oinfo_is_dummy(loi))
1026                                         continue;
1027
1028                                 if (loi->loi_ar.ar_rc && !rc)
1029                                         rc = loi->loi_ar.ar_rc;
1030                                 loi->loi_ar.ar_rc = 0;
1031                         }
1032                 }
1033                 case LLT_RELEASED:
1034                 case LLT_EMPTY:
1035                         break;
1036                 default:
1037                         LBUG();
1038                 }
1039                 lov_conf_thaw(lov);
1040         }
1041         return rc;
1042 }
1043 EXPORT_SYMBOL(lov_read_and_clear_async_rc);
1044
1045 /** @} lov */