lustre/osc/osc_page.c

   1 /* -*- mode: c; c-basic-offset: 8; indent-tabs-mode: nil; -*-
   2  * vim:expandtab:shiftwidth=8:tabstop=8:
   3  *
   4  * GPL HEADER START
   5  *
   6  * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
   7  *
   8  * This program is free software; you can redistribute it and/or modify
   9  * it under the terms of the GNU General Public License version 2 only,
  10  * as published by the Free Software Foundation.
  11  *
  12  * This program is distributed in the hope that it will be useful, but
  13  * WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  15  * General Public License version 2 for more details (a copy is included
  16  * in the LICENSE file that accompanied this code).
  17  *
  18  * You should have received a copy of the GNU General Public License
  19  * version 2 along with this program; If not, see
  20  * http://www.sun.com/software/products/lustre/docs/GPLv2.pdf
  21  *
  22  * Please contact Sun Microsystems, Inc., 4150 Network Circle, Santa Clara,
  23  * CA 95054 USA or visit www.sun.com if you need additional information or
  24  * have any questions.
  25  *
  26  * GPL HEADER END
  27  */
  28 /*
  29  * Copyright 2008 Sun Microsystems, Inc.  All rights reserved.
  30  * Use is subject to license terms.
  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 /** \addtogroup osc osc @{ */
  42
  43 #define DEBUG_SUBSYSTEM S_OSC
  44
  45 #include "osc_cl_internal.h"
  46
  47 static int osc_page_is_dlocked(const struct lu_env *env,
  48                                const struct osc_page *opg,
  49                                enum cl_lock_mode mode, int pending, int unref)
  50 {
  51         struct cl_page         *page;
  52         struct osc_object      *obj;
  53         struct osc_thread_info *info;
  54         struct ldlm_res_id     *resname;
  55         struct lustre_handle   *lockh;
  56         ldlm_policy_data_t     *policy;
  57         ldlm_mode_t             dlmmode;
  58         int                     flags;
  59
  60         info = osc_env_info(env);
  61         resname = &info->oti_resname;
  62         policy = &info->oti_policy;
  63         lockh = &info->oti_handle;
  64         page = opg->ops_cl.cpl_page;
  65         obj = cl2osc(opg->ops_cl.cpl_obj);
  66
  67         flags = LDLM_FL_TEST_LOCK | LDLM_FL_BLOCK_GRANTED;
  68         if (pending)
  69                 flags |= LDLM_FL_CBPENDING;
  70
  71         dlmmode = osc_cl_lock2ldlm(mode) | LCK_PW;
  72         osc_lock_build_res(env, obj, resname);
  73         osc_index2policy(policy, page->cp_obj, page->cp_index, page->cp_index);
  74         return osc_match_base(osc_export(obj), resname, LDLM_EXTENT, policy,
  75                               dlmmode, &flags, NULL, lockh, unref);
  76 }
  77
  78 /**
  79  * Checks an invariant that a page in the cache is covered by a lock, as
  80  * needed.
  81  */
  82 static int osc_page_protected(const struct lu_env *env,
  83                               const struct osc_page *opg,
  84                               enum cl_lock_mode mode, int unref)
  85 {
  86         struct cl_object_header *hdr;
  87         struct cl_lock          *scan;
  88         struct cl_page          *page;
  89         struct cl_lock_descr    *descr;
  90         int result;
  91
  92         LINVRNT(!opg->ops_temp);
  93
  94         page = opg->ops_cl.cpl_page;
  95         if (page->cp_owner != NULL &&
  96             cl_io_top(page->cp_owner)->ci_lockreq == CILR_NEVER)
  97                 /*
  98                  * If IO is done without locks (liblustre, or lloop), lock is
  99                  * not required.
 100                  */
 101                 result = 1;
 102         else
 103                 /* otherwise check for a DLM lock */
 104         result = osc_page_is_dlocked(env, opg, mode, 1, unref);
 105         if (result == 0) {
 106                 /* maybe this page is a part of a lockless io? */
 107                 hdr = cl_object_header(opg->ops_cl.cpl_obj);
 108                 descr = &osc_env_info(env)->oti_descr;
 109                 descr->cld_mode = mode;
 110                 descr->cld_start = page->cp_index;
 111                 descr->cld_end   = page->cp_index;
 112                 spin_lock(&hdr->coh_lock_guard);
 113                 list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
 114                         /*
 115                          * Lock-less sub-lock has to be either in HELD state
 116                          * (when io is actively going on), or in CACHED state,
 117                          * when top-lock is being unlocked:
 118                          * cl_io_unlock()->cl_unuse()->...->lov_lock_unuse().
 119                          */
 120                         if ((scan->cll_state == CLS_HELD ||
 121                              scan->cll_state == CLS_CACHED) &&
 122                             cl_lock_ext_match(&scan->cll_descr, descr)) {
 123                                 struct osc_lock *olck;
 124
 125                                 olck = osc_lock_at(scan);
 126                                 result = osc_lock_is_lockless(olck);
 127                                 break;
 128                         }
 129                 }
 130                 spin_unlock(&hdr->coh_lock_guard);
 131         }
 132         return result;
 133 }
 134
 135 /*****************************************************************************
 136  *
 137  * Page operations.
 138  *
 139  */
 140 static void osc_page_fini(const struct lu_env *env,
 141                           struct cl_page_slice *slice)
 142 {
 143         struct osc_page *opg = cl2osc_page(slice);
 144         CDEBUG(D_TRACE, "%p\n", opg);
 145         OBD_SLAB_FREE_PTR(opg, osc_page_kmem);
 146 }
 147
 148 static void osc_page_transfer_get(struct osc_page *opg, const char *label)
 149 {
 150         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 151
 152         LASSERT(!opg->ops_transfer_pinned);
 153         cl_page_get(page);
 154         lu_ref_add_atomic(&page->cp_reference, label, page);
 155         opg->ops_transfer_pinned = 1;
 156 }
 157
 158 static void osc_page_transfer_put(const struct lu_env *env,
 159                                   struct osc_page *opg)
 160 {
 161         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 162
 163         if (opg->ops_transfer_pinned) {
 164                 lu_ref_del(&page->cp_reference, "transfer", page);
 165                 opg->ops_transfer_pinned = 0;
 166                 cl_page_put(env, page);
 167         }
 168 }
 169
 170 /**
 171  * This is called once for every page when it is submitted for a transfer
 172  * either opportunistic (osc_page_cache_add()), or immediate
 173  * (osc_page_submit()).
 174  */
 175 static void osc_page_transfer_add(const struct lu_env *env,
 176                                   struct osc_page *opg, enum cl_req_type crt)
 177 {
 178         struct osc_object *obj;
 179
 180         LINVRNT(cl_page_is_vmlocked(env, opg->ops_cl.cpl_page));
 181
 182         obj = cl2osc(opg->ops_cl.cpl_obj);
 183         spin_lock(&obj->oo_seatbelt);
 184         list_add(&opg->ops_inflight, &obj->oo_inflight[crt]);
 185         opg->ops_submitter = cfs_current();
 186         spin_unlock(&obj->oo_seatbelt);
 187 }
 188
 189 static int osc_page_cache_add(const struct lu_env *env,
 190                               const struct cl_page_slice *slice,
 191                               struct cl_io *unused)
 192 {
 193         struct osc_page   *opg = cl2osc_page(slice);
 194         struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
 195         struct osc_io     *oio = osc_env_io(env);
 196         int result;
 197         int brw_flags;
 198         int noquota = 0;
 199
 200         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0));
 201         ENTRY;
 202
 203         /* Set the OBD_BRW_SRVLOCK before the page is queued. */
 204         brw_flags = osc_io_srvlock(oio) ? OBD_BRW_SRVLOCK : 0;
 205         if (!client_is_remote(osc_export(obj)) &&
 206             cfs_capable(CFS_CAP_SYS_RESOURCE)) {
 207                 brw_flags |= OBD_BRW_NOQUOTA;
 208                 noquota = OBD_BRW_NOQUOTA;
 209         }
 210
 211         osc_page_transfer_get(opg, "transfer\0cache");
 212         result = osc_queue_async_io(env, osc_export(obj), NULL, obj->oo_oinfo,
 213                                     &opg->ops_oap, OBD_BRW_WRITE | noquota,
 214                                     0, 0, brw_flags, 0);
 215         if (result != 0)
 216                 osc_page_transfer_put(env, opg);
 217         else
 218                 osc_page_transfer_add(env, opg, CRT_WRITE);
 219         RETURN(result);
 220 }
 221
 222 void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj,
 223                       pgoff_t start, pgoff_t end)
 224 {
 225         memset(policy, 0, sizeof *policy);
 226         policy->l_extent.start = cl_offset(obj, start);
 227         policy->l_extent.end   = cl_offset(obj, end + 1) - 1;
 228 }
 229
 230 static int osc_page_is_under_lock(const struct lu_env *env,
 231                                   const struct cl_page_slice *slice,
 232                                   struct cl_io *unused)
 233 {
 234         struct cl_lock *lock;
 235         int             result;
 236
 237         ENTRY;
 238         lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page,
 239                                NULL, 1, 0);
 240         if (lock != NULL) {
 241                 cl_lock_put(env, lock);
 242                 result = -EBUSY;
 243         } else
 244                 result = -ENODATA;
 245         RETURN(result);
 246 }
 247
 248 static int osc_page_fail(const struct lu_env *env,
 249                          const struct cl_page_slice *slice,
 250                          struct cl_io *unused)
 251 {
 252         /*
 253          * Cached read?
 254          */
 255         LBUG();
 256         return 0;
 257 }
 258
 259
 260 static const char *osc_list(struct list_head *head)
 261 {
 262         return list_empty(head) ? "-" : "+";
 263 }
 264
 265 static int osc_page_print(const struct lu_env *env,
 266                           const struct cl_page_slice *slice,
 267                           void *cookie, lu_printer_t printer)
 268 {
 269         struct osc_page       *opg = cl2osc_page(slice);
 270         struct osc_async_page *oap = &opg->ops_oap;
 271
 272         return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: "
 273                           "< %#x %d %u %s %s %s >"
 274                           "< %llu %u %#x %#x %p %p %p %p %p >"
 275                           "< %s %p %d >\n",
 276                           opg,
 277                           /* 1 */
 278                           oap->oap_magic, oap->oap_cmd,
 279                           oap->oap_interrupted,
 280                           osc_list(&oap->oap_pending_item),
 281                           osc_list(&oap->oap_urgent_item),
 282                           osc_list(&oap->oap_rpc_item),
 283                           /* 2 */
 284                           oap->oap_obj_off, oap->oap_page_off,
 285                           oap->oap_async_flags, oap->oap_brw_flags,
 286                           oap->oap_request,
 287                           oap->oap_cli, oap->oap_loi, oap->oap_caller_ops,
 288                           oap->oap_caller_data,
 289                           /* 3 */
 290                           osc_list(&opg->ops_inflight),
 291                           opg->ops_submitter, opg->ops_transfer_pinned);
 292 }
 293
 294 static void osc_page_delete(const struct lu_env *env,
 295                             const struct cl_page_slice *slice)
 296 {
 297         struct osc_page       *opg = cl2osc_page(slice);
 298         struct osc_object     *obj = cl2osc(opg->ops_cl.cpl_obj);
 299         struct osc_async_page *oap = &opg->ops_oap;
 300         int rc;
 301
 302         LINVRNT(opg->ops_temp || osc_page_protected(env, opg, CLM_READ, 1));
 303
 304         ENTRY;
 305         CDEBUG(D_TRACE, "%p\n", opg);
 306         osc_page_transfer_put(env, opg);
 307         rc = osc_teardown_async_page(osc_export(obj), NULL, obj->oo_oinfo, oap);
 308         if (rc) {
 309                 CL_PAGE_DEBUG(D_ERROR, env, cl_page_top(slice->cpl_page),
 310                               "Trying to teardown failed: %d\n", rc);
 311                 LASSERT(0);
 312         }
 313         spin_lock(&obj->oo_seatbelt);
 314         list_del_init(&opg->ops_inflight);
 315         spin_unlock(&obj->oo_seatbelt);
 316         EXIT;
 317 }
 318
 319 void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice,
 320                    int from, int to)
 321 {
 322         struct osc_page       *opg = cl2osc_page(slice);
 323         struct osc_async_page *oap = &opg->ops_oap;
 324
 325         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 326
 327         opg->ops_from = from;
 328         opg->ops_to   = to;
 329         oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 330 }
 331
 332 static int osc_page_cancel(const struct lu_env *env,
 333                            const struct cl_page_slice *slice)
 334 {
 335         struct osc_page *opg       = cl2osc_page(slice);
 336         struct osc_async_page *oap = &opg->ops_oap;
 337         int rc = 0;
 338
 339         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 340
 341         client_obd_list_lock(&oap->oap_cli->cl_loi_list_lock);
 342         /* Check if the transferring against this page
 343          * is completed, or not even queued. */
 344         if (opg->ops_transfer_pinned)
 345                 /* FIXME: may not be interrupted.. */
 346                 rc = osc_oap_interrupted(env, oap);
 347         LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0));
 348         client_obd_list_unlock(&oap->oap_cli->cl_loi_list_lock);
 349         return rc;
 350 }
 351
 352 static const struct cl_page_operations osc_page_ops = {
 353         .cpo_fini          = osc_page_fini,
 354         .cpo_print         = osc_page_print,
 355         .cpo_delete        = osc_page_delete,
 356         .cpo_is_under_lock = osc_page_is_under_lock,
 357         .io = {
 358                 [CRT_READ] = {
 359                         .cpo_cache_add = osc_page_fail
 360                 },
 361                 [CRT_WRITE] = {
 362                         .cpo_cache_add = osc_page_cache_add
 363                 }
 364         },
 365         .cpo_clip           = osc_page_clip,
 366         .cpo_cancel         = osc_page_cancel
 367 };
 368
 369 static int osc_make_ready(const struct lu_env *env, void *data, int cmd)
 370 {
 371         struct osc_page *opg  = data;
 372         struct cl_page  *page = cl_page_top(opg->ops_cl.cpl_page);
 373         int result;
 374
 375         LASSERT(cmd == OBD_BRW_WRITE); /* no cached reads */
 376         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 1));
 377
 378         ENTRY;
 379         result = cl_page_make_ready(env, page, CRT_WRITE);
 380         RETURN(result);
 381 }
 382
 383 static int osc_refresh_count(const struct lu_env *env, void *data, int cmd)
 384 {
 385         struct cl_page   *page;
 386         struct osc_page  *osc = data;
 387         struct cl_object *obj;
 388         struct cl_attr   *attr = &osc_env_info(env)->oti_attr;
 389
 390         int result;
 391         loff_t kms;
 392
 393         LINVRNT(osc_page_protected(env, osc, CLM_READ, 1));
 394
 395         /* readpage queues with _COUNT_STABLE, shouldn't get here. */
 396         LASSERT(!(cmd & OBD_BRW_READ));
 397         LASSERT(osc != NULL);
 398         page = osc->ops_cl.cpl_page;
 399         obj = osc->ops_cl.cpl_obj;
 400
 401         cl_object_attr_lock(obj);
 402         result = cl_object_attr_get(env, obj, attr);
 403         cl_object_attr_unlock(obj);
 404         if (result < 0)
 405                 return result;
 406         kms = attr->cat_kms;
 407         if (cl_offset(obj, page->cp_index) >= kms)
 408                 /* catch race with truncate */
 409                 return 0;
 410         else if (cl_offset(obj, page->cp_index + 1) > kms)
 411                 /* catch sub-page write at end of file */
 412                 return kms % CFS_PAGE_SIZE;
 413         else
 414                 return CFS_PAGE_SIZE;
 415 }
 416
 417 static int osc_completion(const struct lu_env *env,
 418                           void *data, int cmd, struct obdo *oa, int rc)
 419 {
 420         struct osc_page       *opg  = data;
 421         struct osc_async_page *oap  = &opg->ops_oap;
 422         struct cl_page        *page = cl_page_top(opg->ops_cl.cpl_page);
 423         struct osc_object     *obj  = cl2osc(opg->ops_cl.cpl_obj);
 424         enum cl_req_type crt;
 425
 426         LINVRNT(osc_page_protected(env, opg, CLM_READ, 1));
 427         LINVRNT(cl_page_is_vmlocked(env, page));
 428
 429         ENTRY;
 430
 431         cmd &= ~OBD_BRW_NOQUOTA;
 432         LASSERT(equi(page->cp_state == CPS_PAGEIN,  cmd == OBD_BRW_READ));
 433         LASSERT(equi(page->cp_state == CPS_PAGEOUT, cmd == OBD_BRW_WRITE));
 434         LASSERT(opg->ops_transfer_pinned);
 435
 436         /*
 437          * page->cp_req can be NULL if io submission failed before
 438          * cl_req was allocated.
 439          */
 440         if (page->cp_req != NULL)
 441                 cl_req_page_done(env, page);
 442         LASSERT(page->cp_req == NULL);
 443
 444         /* As the transfer for this page is being done, clear the flags */
 445         oap->oap_async_flags = 0;
 446
 447         crt = cmd == OBD_BRW_READ ? CRT_READ : CRT_WRITE;
 448         /* Clear opg->ops_transfer_pinned before VM lock is released. */
 449         opg->ops_transfer_pinned = 0;
 450
 451         spin_lock(&obj->oo_seatbelt);
 452         LASSERT(opg->ops_submitter != NULL);
 453         LASSERT(!list_empty(&opg->ops_inflight));
 454         list_del_init(&opg->ops_inflight);
 455         spin_unlock(&obj->oo_seatbelt);
 456
 457         cl_page_completion(env, page, crt, rc);
 458
 459         /* statistic */
 460         if (rc == 0 && oap->oap_brw_flags & OBD_BRW_SRVLOCK) {
 461                 struct lu_device *ld    = opg->ops_cl.cpl_obj->co_lu.lo_dev;
 462                 struct osc_stats *stats = &lu2osc_dev(ld)->od_stats;
 463                 int bytes = opg->ops_to - opg->ops_from;
 464
 465                 if (crt == CRT_READ)
 466                         stats->os_lockless_reads += bytes;
 467                 else
 468                         stats->os_lockless_writes += bytes;
 469         }
 470
 471         /*
 472          * This has to be the last operation with the page, as locks are
 473          * released in cl_page_completion() and nothing except for the
 474          * reference counter protects page from concurrent reclaim.
 475          */
 476         lu_ref_del(&page->cp_reference, "transfer", page);
 477         /*
 478          * As page->cp_obj is pinned by a reference from page->cp_req, it is
 479          * safe to call cl_page_put() without risking object destruction in a
 480          * non-blocking context.
 481          */
 482         cl_page_put(env, page);
 483         RETURN(0);
 484 }
 485
 486 const static struct obd_async_page_ops osc_async_page_ops = {
 487         .ap_make_ready    = osc_make_ready,
 488         .ap_refresh_count = osc_refresh_count,
 489         .ap_completion    = osc_completion
 490 };
 491
 492 struct cl_page *osc_page_init(const struct lu_env *env,
 493                               struct cl_object *obj,
 494                               struct cl_page *page, cfs_page_t *vmpage)
 495 {
 496         struct osc_object *osc = cl2osc(obj);
 497         struct osc_page   *opg;
 498         int result;
 499
 500         OBD_SLAB_ALLOC_PTR_GFP(opg, osc_page_kmem, CFS_ALLOC_IO);
 501         if (opg != NULL) {
 502                 void *oap = &opg->ops_oap;
 503
 504                 opg->ops_from = 0;
 505                 opg->ops_to   = CFS_PAGE_SIZE;
 506
 507                 result = osc_prep_async_page(osc_export(osc),
 508                                              NULL, osc->oo_oinfo, vmpage,
 509                                              cl_offset(obj, page->cp_index),
 510                                              &osc_async_page_ops,
 511                                              opg, (void **)&oap, 1, NULL);
 512                 if (result == 0)
 513                         cl_page_slice_add(page, &opg->ops_cl, obj,
 514                                           &osc_page_ops);
 515                 /*
 516                  * Cannot assert osc_page_protected() here as read-ahead
 517                  * creates temporary pages outside of a lock.
 518                  */
 519 #ifdef INVARIANT_CHECK
 520                 opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1);
 521 #endif
 522                 CFS_INIT_LIST_HEAD(&opg->ops_inflight);
 523         } else
 524                 result = -ENOMEM;
 525         return ERR_PTR(result);
 526 }
 527
 528 /**
 529  * Helper function called by osc_io_submit() for every page in an immediate
 530  * transfer (i.e., transferred synchronously).
 531  */
 532 void osc_io_submit_page(const struct lu_env *env,
 533                         struct osc_io *oio, struct osc_page *opg,
 534                         enum cl_req_type crt)
 535 {
 536         struct osc_async_page *oap = &opg->ops_oap;
 537         struct client_obd     *cli = oap->oap_cli;
 538
 539         LINVRNT(osc_page_protected(env, opg,
 540                                    crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1));
 541
 542         oap->oap_page_off   = opg->ops_from;
 543         oap->oap_count      = opg->ops_to - opg->ops_from;
 544         /* Give a hint to OST that requests are coming from kswapd - bug19529 */
 545         if (libcfs_memory_pressure_get())
 546                 oap->oap_brw_flags |= OBD_BRW_MEMALLOC;
 547         oap->oap_brw_flags |= OBD_BRW_SYNC;
 548         if (osc_io_srvlock(oio))
 549                 oap->oap_brw_flags |= OBD_BRW_SRVLOCK;
 550
 551         oap->oap_cmd = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ;
 552         if (!client_is_remote(osc_export(cl2osc(opg->ops_cl.cpl_obj))) &&
 553             cfs_capable(CFS_CAP_SYS_RESOURCE)) {
 554                 oap->oap_brw_flags |= OBD_BRW_NOQUOTA;
 555                 oap->oap_cmd |= OBD_BRW_NOQUOTA;
 556         }
 557
 558         oap->oap_async_flags |= OSC_FLAGS;
 559         if (oap->oap_cmd & OBD_BRW_READ)
 560                 oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 561         else if (!(oap->oap_brw_page.flag & OBD_BRW_FROM_GRANT))
 562                 osc_enter_cache_try(env, cli, oap->oap_loi, oap, 1);
 563
 564         osc_oap_to_pending(oap);
 565         osc_page_transfer_get(opg, "transfer\0imm");
 566         osc_page_transfer_add(env, opg, crt);
 567 }
 568
 569 /** @} osc */