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 *unused)
 211 {
 212         struct osc_page *opg = cl2osc_page(slice);
 213         int result;
 214         ENTRY;
 215
 216         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0));
 217
 218         osc_page_transfer_get(opg, "transfer\0cache");
 219         result = osc_queue_async_io(env, opg);
 220         if (result != 0)
 221                 osc_page_transfer_put(env, opg);
 222         else
 223                 osc_page_transfer_add(env, opg, CRT_WRITE);
 224         RETURN(result);
 225 }
 226
 227 void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj,
 228                       pgoff_t start, pgoff_t end)
 229 {
 230         memset(policy, 0, sizeof *policy);
 231         policy->l_extent.start = cl_offset(obj, start);
 232         policy->l_extent.end   = cl_offset(obj, end + 1) - 1;
 233 }
 234
 235 static int osc_page_addref_lock(const struct lu_env *env,
 236                                 struct osc_page *opg,
 237                                 struct cl_lock *lock)
 238 {
 239         struct osc_lock *olock;
 240         int              rc;
 241
 242         LASSERT(opg->ops_lock == NULL);
 243
 244         olock = osc_lock_at(lock);
 245         if (cfs_atomic_inc_return(&olock->ols_pageref) <= 0) {
 246                 cfs_atomic_dec(&olock->ols_pageref);
 247                 cl_lock_put(env, lock);
 248                 rc = 1;
 249         } else {
 250                 opg->ops_lock = lock;
 251                 rc = 0;
 252         }
 253         return rc;
 254 }
 255
 256 static void osc_page_putref_lock(const struct lu_env *env,
 257                                  struct osc_page *opg)
 258 {
 259         struct cl_lock  *lock = opg->ops_lock;
 260         struct osc_lock *olock;
 261
 262         LASSERT(lock != NULL);
 263         olock = osc_lock_at(lock);
 264
 265         cfs_atomic_dec(&olock->ols_pageref);
 266         opg->ops_lock = NULL;
 267
 268         cl_lock_put(env, lock);
 269 }
 270
 271 static int osc_page_is_under_lock(const struct lu_env *env,
 272                                   const struct cl_page_slice *slice,
 273                                   struct cl_io *unused)
 274 {
 275         struct cl_lock *lock;
 276         int             result;
 277
 278         ENTRY;
 279         lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page,
 280                                NULL, 1, 0);
 281         if (lock != NULL &&
 282             osc_page_addref_lock(env, cl2osc_page(slice), lock) == 0)
 283                 result = -EBUSY;
 284         else
 285                 result = -ENODATA;
 286         RETURN(result);
 287 }
 288
 289 static void osc_page_disown(const struct lu_env *env,
 290                             const struct cl_page_slice *slice,
 291                             struct cl_io *io)
 292 {
 293         struct osc_page *opg = cl2osc_page(slice);
 294
 295         if (unlikely(opg->ops_lock))
 296                 osc_page_putref_lock(env, opg);
 297 }
 298
 299 static void osc_page_completion_read(const struct lu_env *env,
 300                                      const struct cl_page_slice *slice,
 301                                      int ioret)
 302 {
 303         struct osc_page *opg = cl2osc_page(slice);
 304
 305         if (likely(opg->ops_lock))
 306                 osc_page_putref_lock(env, opg);
 307 }
 308
 309 static int osc_page_fail(const struct lu_env *env,
 310                          const struct cl_page_slice *slice,
 311                          struct cl_io *unused)
 312 {
 313         /*
 314          * Cached read?
 315          */
 316         LBUG();
 317         return 0;
 318 }
 319
 320
 321 static const char *osc_list(cfs_list_t *head)
 322 {
 323         return cfs_list_empty(head) ? "-" : "+";
 324 }
 325
 326 static inline cfs_time_t osc_submit_duration(struct osc_page *opg)
 327 {
 328         if (opg->ops_submit_time == 0)
 329                 return 0;
 330
 331         return (cfs_time_current() - opg->ops_submit_time);
 332 }
 333
 334 static int osc_page_print(const struct lu_env *env,
 335                           const struct cl_page_slice *slice,
 336                           void *cookie, lu_printer_t printer)
 337 {
 338         struct osc_page       *opg = cl2osc_page(slice);
 339         struct osc_async_page *oap = &opg->ops_oap;
 340         struct osc_object     *obj = cl2osc(slice->cpl_obj);
 341         struct client_obd     *cli = &osc_export(obj)->exp_obd->u.cli;
 342
 343         return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: "
 344                           "1< %#x %d %u %s %s %s > "
 345                           "2< "LPU64" %u %u %#x %#x | %p %p %p > "
 346                           "3< %s %p %d %lu %d > "
 347                           "4< %d %d %d %lu %s | %s %s %s %s > "
 348                           "5< %s %s %s %s | %d %s %s | %d %s %s>\n",
 349                           opg,
 350                           /* 1 */
 351                           oap->oap_magic, oap->oap_cmd,
 352                           oap->oap_interrupted,
 353                           osc_list(&oap->oap_pending_item),
 354                           osc_list(&oap->oap_urgent_item),
 355                           osc_list(&oap->oap_rpc_item),
 356                           /* 2 */
 357                           oap->oap_obj_off, oap->oap_page_off, oap->oap_count,
 358                           oap->oap_async_flags, oap->oap_brw_flags,
 359                           oap->oap_request, oap->oap_cli, obj,
 360                           /* 3 */
 361                           osc_list(&opg->ops_inflight),
 362                           opg->ops_submitter, opg->ops_transfer_pinned,
 363                           osc_submit_duration(opg), opg->ops_srvlock,
 364                           /* 4 */
 365                           cli->cl_r_in_flight, cli->cl_w_in_flight,
 366                           cli->cl_max_rpcs_in_flight,
 367                           cli->cl_avail_grant,
 368                           osc_list(&cli->cl_cache_waiters),
 369                           osc_list(&cli->cl_loi_ready_list),
 370                           osc_list(&cli->cl_loi_hp_ready_list),
 371                           osc_list(&cli->cl_loi_write_list),
 372                           osc_list(&cli->cl_loi_read_list),
 373                           /* 5 */
 374                           osc_list(&obj->oo_ready_item),
 375                           osc_list(&obj->oo_hp_ready_item),
 376                           osc_list(&obj->oo_write_item),
 377                           osc_list(&obj->oo_read_item),
 378                           obj->oo_read_pages.oop_num_pending,
 379                           osc_list(&obj->oo_read_pages.oop_pending),
 380                           osc_list(&obj->oo_read_pages.oop_urgent),
 381                           obj->oo_write_pages.oop_num_pending,
 382                           osc_list(&obj->oo_write_pages.oop_pending),
 383                           osc_list(&obj->oo_write_pages.oop_urgent));
 384 }
 385
 386 static void osc_page_delete(const struct lu_env *env,
 387                             const struct cl_page_slice *slice)
 388 {
 389         struct osc_page   *opg = cl2osc_page(slice);
 390         struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
 391         int rc;
 392
 393         LINVRNT(opg->ops_temp || osc_page_protected(env, opg, CLM_READ, 1));
 394
 395         ENTRY;
 396         CDEBUG(D_TRACE, "%p\n", opg);
 397         osc_page_transfer_put(env, opg);
 398         rc = osc_teardown_async_page(obj, opg);
 399         if (rc) {
 400                 CL_PAGE_DEBUG(D_ERROR, env, cl_page_top(slice->cpl_page),
 401                               "Trying to teardown failed: %d\n", rc);
 402                 LASSERT(0);
 403         }
 404         cfs_spin_lock(&obj->oo_seatbelt);
 405         cfs_list_del_init(&opg->ops_inflight);
 406         cfs_spin_unlock(&obj->oo_seatbelt);
 407         EXIT;
 408 }
 409
 410 void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice,
 411                    int from, int to)
 412 {
 413         struct osc_page       *opg = cl2osc_page(slice);
 414         struct osc_async_page *oap = &opg->ops_oap;
 415
 416         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 417
 418         opg->ops_from = from;
 419         opg->ops_to   = to;
 420         cfs_spin_lock(&oap->oap_lock);
 421         oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 422         cfs_spin_unlock(&oap->oap_lock);
 423 }
 424
 425 static int osc_page_cancel(const struct lu_env *env,
 426                            const struct cl_page_slice *slice)
 427 {
 428         struct osc_page *opg       = cl2osc_page(slice);
 429         struct osc_async_page *oap = &opg->ops_oap;
 430         int rc = 0;
 431
 432         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 433
 434         client_obd_list_lock(&oap->oap_cli->cl_loi_list_lock);
 435         /* Check if the transferring against this page
 436          * is completed, or not even queued. */
 437         if (opg->ops_transfer_pinned)
 438                 /* FIXME: may not be interrupted.. */
 439                 rc = osc_cancel_async_page(env, opg);
 440         LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0));
 441         client_obd_list_unlock(&oap->oap_cli->cl_loi_list_lock);
 442         return rc;
 443 }
 444
 445 static const struct cl_page_operations osc_page_ops = {
 446         .cpo_fini          = osc_page_fini,
 447         .cpo_print         = osc_page_print,
 448         .cpo_delete        = osc_page_delete,
 449         .cpo_is_under_lock = osc_page_is_under_lock,
 450         .cpo_disown        = osc_page_disown,
 451         .io = {
 452                 [CRT_READ] = {
 453                         .cpo_cache_add  = osc_page_fail,
 454                         .cpo_completion = osc_page_completion_read
 455                 },
 456                 [CRT_WRITE] = {
 457                         .cpo_cache_add  = osc_page_cache_add
 458                 }
 459         },
 460         .cpo_clip           = osc_page_clip,
 461         .cpo_cancel         = osc_page_cancel
 462 };
 463
 464 struct cl_page *osc_page_init(const struct lu_env *env,
 465                               struct cl_object *obj,
 466                               struct cl_page *page, cfs_page_t *vmpage)
 467 {
 468         struct osc_object *osc = cl2osc(obj);
 469         struct osc_page   *opg;
 470         int result;
 471
 472         OBD_SLAB_ALLOC_PTR_GFP(opg, osc_page_kmem, CFS_ALLOC_IO);
 473         if (opg != NULL) {
 474                 opg->ops_from = 0;
 475                 opg->ops_to   = CFS_PAGE_SIZE;
 476
 477                 result = osc_prep_async_page(osc, opg, vmpage,
 478                                              cl_offset(obj, page->cp_index));
 479                 if (result == 0) {
 480                         struct osc_io *oio = osc_env_io(env);
 481                         opg->ops_srvlock = osc_io_srvlock(oio);
 482                         cl_page_slice_add(page, &opg->ops_cl, obj,
 483                                           &osc_page_ops);
 484                 }
 485                 /*
 486                  * Cannot assert osc_page_protected() here as read-ahead
 487                  * creates temporary pages outside of a lock.
 488                  */
 489 #ifdef INVARIANT_CHECK
 490                 opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1);
 491 #endif
 492                 CFS_INIT_LIST_HEAD(&opg->ops_inflight);
 493         } else
 494                 result = -ENOMEM;
 495         return ERR_PTR(result);
 496 }
 497
 498 /**
 499  * Helper function called by osc_io_submit() for every page in an immediate
 500  * transfer (i.e., transferred synchronously).
 501  */
 502 void osc_io_submit_page(const struct lu_env *env,
 503                         struct osc_io *oio, struct osc_page *opg,
 504                         enum cl_req_type crt)
 505 {
 506         LINVRNT(osc_page_protected(env, opg,
 507                                    crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1));
 508
 509         osc_queue_sync_page(env, opg,
 510                             crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ,
 511                             osc_io_srvlock(oio) ? OBD_BRW_SRVLOCK : 0);
 512
 513         osc_page_transfer_get(opg, "transfer\0imm");
 514         osc_page_transfer_add(env, opg, crt);
 515 }
 516
 517 /** @} osc */