lustre/osc/osc_page.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.sun.com/software/products/lustre/docs/GPLv2.pdf
  19  *
  20  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  21  * CA 95054 USA or visit www.sun.com if you need additional information or
  22  * have any questions.
  23  *
  24  * GPL HEADER END
  25  */
  26 /*
  27  * Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.
  28  * Use is subject to license terms.
  29  *
  30  * Copyright (c) 2011, Whamcloud, Inc.
  31  */
  32 /*
  33  * This file is part of Lustre, http://www.lustre.org/
  34  * Lustre is a trademark of Sun Microsystems, Inc.
  35  *
  36  * Implementation of cl_page for OSC layer.
  37  *
  38  *   Author: Nikita Danilov <nikita.danilov@sun.com>
  39  */
  40
  41 #define DEBUG_SUBSYSTEM S_OSC
  42
  43 #include "osc_cl_internal.h"
  44
  45 /** \addtogroup osc
  46  *  @{
  47  */
  48
  49 /*
  50  * Comment out osc_page_protected because it may sleep inside the
  51  * the client_obd_list_lock.
  52  * client_obd_list_lock -> osc_ap_completion -> osc_completion ->
  53  *   -> osc_page_protected -> osc_page_is_dlocked -> osc_match_base
  54  *   -> ldlm_lock_match -> sptlrpc_import_check_ctx -> sleep.
  55  */
  56 #if 0
  57 static int osc_page_is_dlocked(const struct lu_env *env,
  58                                const struct osc_page *opg,
  59                                enum cl_lock_mode mode, int pending, int unref)
  60 {
  61         struct cl_page         *page;
  62         struct osc_object      *obj;
  63         struct osc_thread_info *info;
  64         struct ldlm_res_id     *resname;
  65         struct lustre_handle   *lockh;
  66         ldlm_policy_data_t     *policy;
  67         ldlm_mode_t             dlmmode;
  68         int                     flags;
  69
  70         cfs_might_sleep();
  71
  72         info = osc_env_info(env);
  73         resname = &info->oti_resname;
  74         policy = &info->oti_policy;
  75         lockh = &info->oti_handle;
  76         page = opg->ops_cl.cpl_page;
  77         obj = cl2osc(opg->ops_cl.cpl_obj);
  78
  79         flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED;
  80         if (pending)
  81                 flags |= LDLM_FL_CBPENDING;
  82
  83         dlmmode = osc_cl_lock2ldlm(mode) | LCK_PW;
  84         osc_lock_build_res(env, obj, resname);
  85         osc_index2policy(policy, page->cp_obj, page->cp_index, page->cp_index);
  86         return osc_match_base(osc_export(obj), resname, LDLM_EXTENT, policy,
  87                               dlmmode, &flags, NULL, lockh, unref);
  88 }
  89
  90 /**
  91  * Checks an invariant that a page in the cache is covered by a lock, as
  92  * needed.
  93  */
  94 static int osc_page_protected(const struct lu_env *env,
  95                               const struct osc_page *opg,
  96                               enum cl_lock_mode mode, int unref)
  97 {
  98         struct cl_object_header *hdr;
  99         struct cl_lock          *scan;
 100         struct cl_page          *page;
 101         struct cl_lock_descr    *descr;
 102         int result;
 103
 104         LINVRNT(!opg->ops_temp);
 105
 106         page = opg->ops_cl.cpl_page;
 107         if (page->cp_owner != NULL &&
 108             cl_io_top(page->cp_owner)->ci_lockreq == CILR_NEVER)
 109                 /*
 110                  * If IO is done without locks (liblustre, or lloop), lock is
 111                  * not required.
 112                  */
 113                 result = 1;
 114         else
 115                 /* otherwise check for a DLM lock */
 116         result = osc_page_is_dlocked(env, opg, mode, 1, unref);
 117         if (result == 0) {
 118                 /* maybe this page is a part of a lockless io? */
 119                 hdr = cl_object_header(opg->ops_cl.cpl_obj);
 120                 descr = &osc_env_info(env)->oti_descr;
 121                 descr->cld_mode = mode;
 122                 descr->cld_start = page->cp_index;
 123                 descr->cld_end   = page->cp_index;
 124                 cfs_spin_lock(&hdr->coh_lock_guard);
 125                 cfs_list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
 126                         /*
 127                          * Lock-less sub-lock has to be either in HELD state
 128                          * (when io is actively going on), or in CACHED state,
 129                          * when top-lock is being unlocked:
 130                          * cl_io_unlock()->cl_unuse()->...->lov_lock_unuse().
 131                          */
 132                         if ((scan->cll_state == CLS_HELD ||
 133                              scan->cll_state == CLS_CACHED) &&
 134                             cl_lock_ext_match(&scan->cll_descr, descr)) {
 135                                 struct osc_lock *olck;
 136
 137                                 olck = osc_lock_at(scan);
 138                                 result = osc_lock_is_lockless(olck);
 139                                 break;
 140                         }
 141                 }
 142                 cfs_spin_unlock(&hdr->coh_lock_guard);
 143         }
 144         return result;
 145 }
 146 #else
 147 static int osc_page_protected(const struct lu_env *env,
 148                               const struct osc_page *opg,
 149                               enum cl_lock_mode mode, int unref)
 150 {
 151         return 1;
 152 }
 153 #endif
 154
 155 /*****************************************************************************
 156  *
 157  * Page operations.
 158  *
 159  */
 160 static void osc_page_fini(const struct lu_env *env,
 161                           struct cl_page_slice *slice)
 162 {
 163         struct osc_page *opg = cl2osc_page(slice);
 164         CDEBUG(D_TRACE, "%p\n", opg);
 165         LASSERT(opg->ops_lock == NULL);
 166         OBD_SLAB_FREE_PTR(opg, osc_page_kmem);
 167 }
 168
 169 static void osc_page_transfer_get(struct osc_page *opg, const char *label)
 170 {
 171         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 172
 173         LASSERT(!opg->ops_transfer_pinned);
 174         cl_page_get(page);
 175         lu_ref_add_atomic(&page->cp_reference, label, page);
 176         opg->ops_transfer_pinned = 1;
 177 }
 178
 179 static void osc_page_transfer_put(const struct lu_env *env,
 180                                   struct osc_page *opg)
 181 {
 182         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 183
 184         if (opg->ops_transfer_pinned) {
 185                 lu_ref_del(&page->cp_reference, "transfer", page);
 186                 opg->ops_transfer_pinned = 0;
 187                 cl_page_put(env, page);
 188         }
 189 }
 190
 191 /**
 192  * This is called once for every page when it is submitted for a transfer
 193  * either opportunistic (osc_page_cache_add()), or immediate
 194  * (osc_page_submit()).
 195  */
 196 static void osc_page_transfer_add(const struct lu_env *env,
 197                                   struct osc_page *opg, enum cl_req_type crt)
 198 {
 199         struct osc_object *obj;
 200
 201         obj = cl2osc(opg->ops_cl.cpl_obj);
 202         cfs_spin_lock(&obj->oo_seatbelt);
 203         cfs_list_add(&opg->ops_inflight, &obj->oo_inflight[crt]);
 204         opg->ops_submitter = cfs_current();
 205         cfs_spin_unlock(&obj->oo_seatbelt);
 206 }
 207
 208 static int osc_page_cache_add(const struct lu_env *env,
 209                               const struct cl_page_slice *slice,
 210                               struct cl_io *io)
 211 {
 212         struct osc_io   *oio = osc_env_io(env);
 213         struct osc_page *opg = cl2osc_page(slice);
 214         int result;
 215         ENTRY;
 216
 217         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0));
 218
 219         osc_page_transfer_get(opg, "transfer\0cache");
 220         result = osc_queue_async_io(env, io, opg);
 221         if (result != 0)
 222                 osc_page_transfer_put(env, opg);
 223         else
 224                 osc_page_transfer_add(env, opg, CRT_WRITE);
 225
 226         /* for sync write, kernel will wait for this page to be flushed before
 227          * osc_io_end() is called, so release it earlier.
 228          * for mkwrite(), it's known there is no further pages. */
 229         if (cl_io_is_sync_write(io) || cl_io_is_mkwrite(io)) {
 230                 if (oio->oi_active != NULL) {
 231                         osc_extent_release(env, oio->oi_active);
 232                         oio->oi_active = NULL;
 233                 }
 234         }
 235
 236         RETURN(result);
 237 }
 238
 239 void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj,
 240                       pgoff_t start, pgoff_t end)
 241 {
 242         memset(policy, 0, sizeof *policy);
 243         policy->l_extent.start = cl_offset(obj, start);
 244         policy->l_extent.end   = cl_offset(obj, end + 1) - 1;
 245 }
 246
 247 static int osc_page_addref_lock(const struct lu_env *env,
 248                                 struct osc_page *opg,
 249                                 struct cl_lock *lock)
 250 {
 251         struct osc_lock *olock;
 252         int              rc;
 253
 254         LASSERT(opg->ops_lock == NULL);
 255
 256         olock = osc_lock_at(lock);
 257         if (cfs_atomic_inc_return(&olock->ols_pageref) <= 0) {
 258                 cfs_atomic_dec(&olock->ols_pageref);
 259                 cl_lock_put(env, lock);
 260                 rc = 1;
 261         } else {
 262                 opg->ops_lock = lock;
 263                 rc = 0;
 264         }
 265         return rc;
 266 }
 267
 268 static void osc_page_putref_lock(const struct lu_env *env,
 269                                  struct osc_page *opg)
 270 {
 271         struct cl_lock  *lock = opg->ops_lock;
 272         struct osc_lock *olock;
 273
 274         LASSERT(lock != NULL);
 275         olock = osc_lock_at(lock);
 276
 277         cfs_atomic_dec(&olock->ols_pageref);
 278         opg->ops_lock = NULL;
 279
 280         cl_lock_put(env, lock);
 281 }
 282
 283 static int osc_page_is_under_lock(const struct lu_env *env,
 284                                   const struct cl_page_slice *slice,
 285                                   struct cl_io *unused)
 286 {
 287         struct cl_lock *lock;
 288         int             result;
 289
 290         ENTRY;
 291         lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page,
 292                                NULL, 1, 0);
 293         if (lock != NULL &&
 294             osc_page_addref_lock(env, cl2osc_page(slice), lock) == 0)
 295                 result = -EBUSY;
 296         else
 297                 result = -ENODATA;
 298         RETURN(result);
 299 }
 300
 301 static void osc_page_disown(const struct lu_env *env,
 302                             const struct cl_page_slice *slice,
 303                             struct cl_io *io)
 304 {
 305         struct osc_page *opg = cl2osc_page(slice);
 306
 307         if (unlikely(opg->ops_lock))
 308                 osc_page_putref_lock(env, opg);
 309 }
 310
 311 static void osc_page_completion_read(const struct lu_env *env,
 312                                      const struct cl_page_slice *slice,
 313                                      int ioret)
 314 {
 315         struct osc_page *opg = cl2osc_page(slice);
 316
 317         if (likely(opg->ops_lock))
 318                 osc_page_putref_lock(env, opg);
 319 }
 320
 321 static int osc_page_fail(const struct lu_env *env,
 322                          const struct cl_page_slice *slice,
 323                          struct cl_io *unused)
 324 {
 325         /*
 326          * Cached read?
 327          */
 328         LBUG();
 329         return 0;
 330 }
 331
 332
 333 static const char *osc_list(cfs_list_t *head)
 334 {
 335         return cfs_list_empty(head) ? "-" : "+";
 336 }
 337
 338 static inline cfs_time_t osc_submit_duration(struct osc_page *opg)
 339 {
 340         if (opg->ops_submit_time == 0)
 341                 return 0;
 342
 343         return (cfs_time_current() - opg->ops_submit_time);
 344 }
 345
 346 static int osc_page_print(const struct lu_env *env,
 347                           const struct cl_page_slice *slice,
 348                           void *cookie, lu_printer_t printer)
 349 {
 350         struct osc_page       *opg = cl2osc_page(slice);
 351         struct osc_async_page *oap = &opg->ops_oap;
 352         struct osc_object     *obj = cl2osc(slice->cpl_obj);
 353         struct client_obd     *cli = &osc_export(obj)->exp_obd->u.cli;
 354
 355         return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: "
 356                           "1< %#x %d %u %s %s > "
 357                           "2< "LPU64" %u %u %#x %#x | %p %p %p > "
 358                           "3< %s %p %d %lu %d > "
 359                           "4< %d %d %d %lu %s | %s %s %s %s > "
 360                           "5< %s %s %s %s | %d %s | %d %s %s>\n",
 361                           opg,
 362                           /* 1 */
 363                           oap->oap_magic, oap->oap_cmd,
 364                           oap->oap_interrupted,
 365                           osc_list(&oap->oap_pending_item),
 366                           osc_list(&oap->oap_rpc_item),
 367                           /* 2 */
 368                           oap->oap_obj_off, oap->oap_page_off, oap->oap_count,
 369                           oap->oap_async_flags, oap->oap_brw_flags,
 370                           oap->oap_request, oap->oap_cli, obj,
 371                           /* 3 */
 372                           osc_list(&opg->ops_inflight),
 373                           opg->ops_submitter, opg->ops_transfer_pinned,
 374                           osc_submit_duration(opg), opg->ops_srvlock,
 375                           /* 4 */
 376                           cli->cl_r_in_flight, cli->cl_w_in_flight,
 377                           cli->cl_max_rpcs_in_flight,
 378                           cli->cl_avail_grant,
 379                           osc_list(&cli->cl_cache_waiters),
 380                           osc_list(&cli->cl_loi_ready_list),
 381                           osc_list(&cli->cl_loi_hp_ready_list),
 382                           osc_list(&cli->cl_loi_write_list),
 383                           osc_list(&cli->cl_loi_read_list),
 384                           /* 5 */
 385                           osc_list(&obj->oo_ready_item),
 386                           osc_list(&obj->oo_hp_ready_item),
 387                           osc_list(&obj->oo_write_item),
 388                           osc_list(&obj->oo_read_item),
 389                           cfs_atomic_read(&obj->oo_nr_reads),
 390                           osc_list(&obj->oo_reading_exts),
 391                           cfs_atomic_read(&obj->oo_nr_writes),
 392                           osc_list(&obj->oo_hp_exts),
 393                           osc_list(&obj->oo_urgent_exts));
 394 }
 395
 396 static void osc_page_delete(const struct lu_env *env,
 397                             const struct cl_page_slice *slice)
 398 {
 399         struct osc_page   *opg = cl2osc_page(slice);
 400         struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
 401         int rc;
 402
 403         LINVRNT(opg->ops_temp || osc_page_protected(env, opg, CLM_READ, 1));
 404
 405         ENTRY;
 406         CDEBUG(D_TRACE, "%p\n", opg);
 407         osc_page_transfer_put(env, opg);
 408         rc = osc_teardown_async_page(env, obj, opg);
 409         if (rc) {
 410                 CL_PAGE_DEBUG(D_ERROR, env, cl_page_top(slice->cpl_page),
 411                               "Trying to teardown failed: %d\n", rc);
 412                 LASSERT(0);
 413         }
 414         cfs_spin_lock(&obj->oo_seatbelt);
 415         cfs_list_del_init(&opg->ops_inflight);
 416         cfs_spin_unlock(&obj->oo_seatbelt);
 417         EXIT;
 418 }
 419
 420 void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice,
 421                    int from, int to)
 422 {
 423         struct osc_page       *opg = cl2osc_page(slice);
 424         struct osc_async_page *oap = &opg->ops_oap;
 425
 426         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 427
 428         opg->ops_from = from;
 429         opg->ops_to   = to;
 430         cfs_spin_lock(&oap->oap_lock);
 431         oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 432         cfs_spin_unlock(&oap->oap_lock);
 433 }
 434
 435 static int osc_page_cancel(const struct lu_env *env,
 436                            const struct cl_page_slice *slice)
 437 {
 438         struct osc_page *opg = cl2osc_page(slice);
 439         int rc = 0;
 440
 441         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 442
 443         /* Check if the transferring against this page
 444          * is completed, or not even queued. */
 445         if (opg->ops_transfer_pinned)
 446                 /* FIXME: may not be interrupted.. */
 447                 rc = osc_cancel_async_page(env, opg);
 448         LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0));
 449         return rc;
 450 }
 451
 452 static int osc_page_flush(const struct lu_env *env,
 453                           const struct cl_page_slice *slice,
 454                           struct cl_io *io)
 455 {
 456         struct osc_page *opg = cl2osc_page(slice);
 457         int rc = 0;
 458         ENTRY;
 459         rc = osc_flush_async_page(env, io, opg);
 460         RETURN(rc);
 461 }
 462
 463 static const struct cl_page_operations osc_page_ops = {
 464         .cpo_fini          = osc_page_fini,
 465         .cpo_print         = osc_page_print,
 466         .cpo_delete        = osc_page_delete,
 467         .cpo_is_under_lock = osc_page_is_under_lock,
 468         .cpo_disown        = osc_page_disown,
 469         .io = {
 470                 [CRT_READ] = {
 471                         .cpo_cache_add  = osc_page_fail,
 472                         .cpo_completion = osc_page_completion_read
 473                 },
 474                 [CRT_WRITE] = {
 475                         .cpo_cache_add  = osc_page_cache_add
 476                 }
 477         },
 478         .cpo_clip           = osc_page_clip,
 479         .cpo_cancel         = osc_page_cancel,
 480         .cpo_flush          = osc_page_flush
 481 };
 482
 483 struct cl_page *osc_page_init(const struct lu_env *env,
 484                               struct cl_object *obj,
 485                               struct cl_page *page, cfs_page_t *vmpage)
 486 {
 487         struct osc_object *osc = cl2osc(obj);
 488         struct osc_page   *opg;
 489         int result;
 490
 491         OBD_SLAB_ALLOC_PTR_GFP(opg, osc_page_kmem, CFS_ALLOC_IO);
 492         if (opg != NULL) {
 493                 opg->ops_from = 0;
 494                 opg->ops_to   = CFS_PAGE_SIZE;
 495
 496                 result = osc_prep_async_page(osc, opg, vmpage,
 497                                              cl_offset(obj, page->cp_index));
 498                 if (result == 0) {
 499                         struct osc_io *oio = osc_env_io(env);
 500                         opg->ops_srvlock = osc_io_srvlock(oio);
 501                         cl_page_slice_add(page, &opg->ops_cl, obj,
 502                                           &osc_page_ops);
 503                 }
 504                 /*
 505                  * Cannot assert osc_page_protected() here as read-ahead
 506                  * creates temporary pages outside of a lock.
 507                  */
 508 #ifdef INVARIANT_CHECK
 509                 opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1);
 510 #endif
 511                 CFS_INIT_LIST_HEAD(&opg->ops_inflight);
 512         } else
 513                 result = -ENOMEM;
 514         return ERR_PTR(result);
 515 }
 516
 517 /**
 518  * Helper function called by osc_io_submit() for every page in an immediate
 519  * transfer (i.e., transferred synchronously).
 520  */
 521 void osc_page_submit(const struct lu_env *env, struct osc_page *opg,
 522                      enum cl_req_type crt, int brw_flags)
 523 {
 524         struct osc_async_page *oap = &opg->ops_oap;
 525         struct osc_object     *obj = oap->oap_obj;
 526
 527         LINVRNT(osc_page_protected(env, opg,
 528                                    crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1));
 529
 530         LASSERTF(oap->oap_magic == OAP_MAGIC, "Bad oap magic: oap %p, "
 531                  "magic 0x%x\n", oap, oap->oap_magic);
 532         LASSERT(oap->oap_async_flags & ASYNC_READY);
 533         LASSERT(oap->oap_async_flags & ASYNC_COUNT_STABLE);
 534
 535         oap->oap_cmd       = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ;
 536         oap->oap_page_off  = opg->ops_from;
 537         oap->oap_count     = opg->ops_to - opg->ops_from;
 538         oap->oap_brw_flags = OBD_BRW_SYNC | brw_flags;
 539
 540         if (!client_is_remote(osc_export(obj)) &&
 541                         cfs_capable(CFS_CAP_SYS_RESOURCE)) {
 542                 oap->oap_brw_flags |= OBD_BRW_NOQUOTA;
 543                 oap->oap_cmd |= OBD_BRW_NOQUOTA;
 544         }
 545
 546         opg->ops_submit_time = cfs_time_current();
 547         osc_page_transfer_get(opg, "transfer\0imm");
 548         osc_page_transfer_add(env, opg, crt);
 549 }
 550
 551 /** @} osc */