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 static int osc_page_protected(const struct lu_env *env,
  79                               const struct osc_page *opg,
  80                               enum cl_lock_mode mode, int unref)
  81 {
  82         struct cl_object_header *hdr;
  83         struct cl_lock          *scan;
  84         struct cl_page          *page;
  85         struct cl_lock_descr    *descr;
  86         int result;
  87
  88         LINVRNT(!opg->ops_temp);
  89
  90         result = osc_page_is_dlocked(env, opg, mode, 1, unref);
  91         if (result == 0) {
  92                 /* maybe this page is a part of a lockless io? */
  93                 hdr = cl_object_header(opg->ops_cl.cpl_obj);
  94                 page = opg->ops_cl.cpl_page;
  95                 descr = &osc_env_info(env)->oti_descr;
  96                 descr->cld_mode = mode;
  97                 descr->cld_start = page->cp_index;
  98                 descr->cld_end   = page->cp_index;
  99                 spin_lock(&hdr->coh_lock_guard);
 100                 list_for_each_entry(scan, &hdr->coh_locks, cll_linkage) {
 101                         /*
 102                          * Lock-less sub-lock has to be either in HELD state
 103                          * (when io is actively going on), or in CACHED state,
 104                          * when top-lock is being unlocked:
 105                          * cl_io_unlock()->cl_unuse()->...->lov_lock_unuse().
 106                          */
 107                         if ((scan->cll_state == CLS_HELD ||
 108                              scan->cll_state == CLS_CACHED) &&
 109                             cl_lock_ext_match(&scan->cll_descr, descr)) {
 110                                 struct osc_lock *olck;
 111
 112                                 olck = osc_lock_at(scan);
 113                                 result = osc_lock_is_lockless(olck);
 114                                 break;
 115                         }
 116                 }
 117                 spin_unlock(&hdr->coh_lock_guard);
 118         }
 119         return result;
 120 }
 121
 122 /*****************************************************************************
 123  *
 124  * Page operations.
 125  *
 126  */
 127 static void osc_page_fini(const struct lu_env *env,
 128                           struct cl_page_slice *slice)
 129 {
 130         struct osc_page *opg = cl2osc_page(slice);
 131         CDEBUG(D_TRACE, "%p\n", opg);
 132         OBD_SLAB_FREE_PTR(opg, osc_page_kmem);
 133 }
 134
 135 static void osc_page_transfer_get(struct osc_page *opg, const char *label)
 136 {
 137         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 138
 139         LASSERT(!opg->ops_transfer_pinned);
 140         cl_page_get(page);
 141         lu_ref_add_atomic(&page->cp_reference, label, page);
 142         opg->ops_transfer_pinned = 1;
 143 }
 144
 145 static void osc_page_transfer_put(const struct lu_env *env,
 146                                   struct osc_page *opg)
 147 {
 148         struct cl_page *page = cl_page_top(opg->ops_cl.cpl_page);
 149
 150         if (opg->ops_transfer_pinned) {
 151                 lu_ref_del(&page->cp_reference, "transfer", page);
 152                 opg->ops_transfer_pinned = 0;
 153                 cl_page_put(env, page);
 154         }
 155 }
 156
 157 /**
 158  * This is called once for every page when it is submitted for a transfer
 159  * either opportunistic (osc_page_cache_add()), or immediate
 160  * (osc_page_submit()).
 161  */
 162 static void osc_page_transfer_add(const struct lu_env *env,
 163                                   struct osc_page *opg, enum cl_req_type crt)
 164 {
 165         struct osc_object *obj;
 166
 167         obj = cl2osc(opg->ops_cl.cpl_obj);
 168         spin_lock(&obj->oo_seatbelt);
 169         list_add(&opg->ops_inflight, &obj->oo_inflight[crt]);
 170         opg->ops_submitter = cfs_current();
 171         spin_unlock(&obj->oo_seatbelt);
 172 }
 173
 174 static int osc_page_cache_add(const struct lu_env *env,
 175                               const struct cl_page_slice *slice,
 176                               struct cl_io *_)
 177 {
 178         struct osc_page   *opg = cl2osc_page(slice);
 179         struct osc_object *obj = cl2osc(opg->ops_cl.cpl_obj);
 180         struct osc_io     *oio = osc_env_io(env);
 181         int result;
 182         int brw_flags;
 183
 184         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 0));
 185         ENTRY;
 186
 187         /* Set the OBD_BRW_SRVLOCK before the page is queued. */
 188         brw_flags = oio->oi_lockless ? OBD_BRW_SRVLOCK : 0;
 189
 190         osc_page_transfer_get(opg, "transfer\0cache");
 191         result = osc_queue_async_io(env, osc_export(obj), NULL, obj->oo_oinfo,
 192                                     &opg->ops_oap, OBD_BRW_WRITE,
 193                                     0, 0, brw_flags, 0);
 194         if (result != 0)
 195                 osc_page_transfer_put(env, opg);
 196         else
 197                 osc_page_transfer_add(env, opg, CRT_WRITE);
 198         RETURN(result);
 199 }
 200
 201 void osc_index2policy(ldlm_policy_data_t *policy, const struct cl_object *obj,
 202                       pgoff_t start, pgoff_t end)
 203 {
 204         memset(policy, 0, sizeof *policy);
 205         policy->l_extent.start = cl_offset(obj, start);
 206         policy->l_extent.end   = cl_offset(obj, end + 1) - 1;
 207 }
 208
 209 static int osc_page_is_under_lock(const struct lu_env *env,
 210                                   const struct cl_page_slice *slice,
 211                                   struct cl_io *_)
 212 {
 213         struct cl_lock *lock;
 214         int             result;
 215
 216         ENTRY;
 217         lock = cl_lock_at_page(env, slice->cpl_obj, slice->cpl_page,
 218                                NULL, 1, 0);
 219         if (lock != NULL) {
 220                 cl_lock_put(env, lock);
 221                 result = -EBUSY;
 222         } else
 223                 result = -ENODATA;
 224         RETURN(result);
 225 }
 226
 227 static int osc_page_fail(const struct lu_env *env,
 228                          const struct cl_page_slice *slice, struct cl_io *_)
 229 {
 230         /*
 231          * Cached read?
 232          */
 233         LBUG();
 234         return 0;
 235 }
 236
 237
 238 static const char *osc_list(struct list_head *head)
 239 {
 240         return list_empty(head) ? "-" : "+";
 241 }
 242
 243 static int osc_page_print(const struct lu_env *env,
 244                           const struct cl_page_slice *slice,
 245                           void *cookie, lu_printer_t printer)
 246 {
 247         struct osc_page       *opg = cl2osc_page(slice);
 248         struct osc_async_page *oap = &opg->ops_oap;
 249
 250         return (*printer)(env, cookie, LUSTRE_OSC_NAME"-page@%p: "
 251                           "%#x %d %u %s %s %s %llu %u %#x %p %p %p %p %p\n",
 252                           opg, oap->oap_magic, oap->oap_cmd,
 253                           oap->oap_interrupted,
 254                           osc_list(&oap->oap_pending_item),
 255                           osc_list(&oap->oap_urgent_item),
 256                           osc_list(&oap->oap_rpc_item),
 257                           oap->oap_obj_off, oap->oap_page_off,
 258                           oap->oap_async_flags, oap->oap_request,
 259                           oap->oap_cli, oap->oap_loi, oap->oap_caller_ops,
 260                           oap->oap_caller_data);
 261 }
 262
 263 static void osc_page_delete(const struct lu_env *env,
 264                             const struct cl_page_slice *slice)
 265 {
 266         struct osc_page       *opg = cl2osc_page(slice);
 267         struct osc_object     *obj = cl2osc(opg->ops_cl.cpl_obj);
 268         struct osc_async_page *oap = &opg->ops_oap;
 269         int rc;
 270
 271         LINVRNT(opg->ops_temp || osc_page_protected(env, opg, CLM_READ, 1));
 272
 273         ENTRY;
 274         CDEBUG(D_TRACE, "%p\n", opg);
 275         osc_page_transfer_put(env, opg);
 276         rc = osc_teardown_async_page(osc_export(obj), NULL, obj->oo_oinfo, oap);
 277         LASSERTF(rc == 0, "%i\n", rc);
 278         spin_lock(&obj->oo_seatbelt);
 279         list_del_init(&opg->ops_inflight);
 280         spin_unlock(&obj->oo_seatbelt);
 281         EXIT;
 282 }
 283
 284 void osc_page_clip(const struct lu_env *env, const struct cl_page_slice *slice,
 285                    int from, int to)
 286 {
 287         struct osc_page       *opg = cl2osc_page(slice);
 288         struct osc_async_page *oap = &opg->ops_oap;
 289
 290         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 291
 292         opg->ops_from = from;
 293         opg->ops_to   = to;
 294         oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 295 }
 296
 297 static int osc_page_cancel(const struct lu_env *env,
 298                            const struct cl_page_slice *slice)
 299 {
 300         struct osc_page *opg       = cl2osc_page(slice);
 301         struct osc_async_page *oap = &opg->ops_oap;
 302         int rc = 0;
 303
 304         LINVRNT(osc_page_protected(env, opg, CLM_READ, 0));
 305
 306         client_obd_list_lock(&oap->oap_cli->cl_loi_list_lock);
 307         /* Check if the transferring against this page
 308          * is completed, or not even queued. */
 309         if (opg->ops_transfer_pinned)
 310                 /* FIXME: may not be interrupted.. */
 311                 rc = osc_oap_interrupted(env, oap);
 312         LASSERT(ergo(rc == 0, opg->ops_transfer_pinned == 0));
 313         client_obd_list_unlock(&oap->oap_cli->cl_loi_list_lock);
 314         return rc;
 315 }
 316
 317 static const struct cl_page_operations osc_page_ops = {
 318         .cpo_fini          = osc_page_fini,
 319         .cpo_print         = osc_page_print,
 320         .cpo_delete        = osc_page_delete,
 321         .cpo_is_under_lock = osc_page_is_under_lock,
 322         .io = {
 323                 [CRT_READ] = {
 324                         .cpo_cache_add = osc_page_fail
 325                 },
 326                 [CRT_WRITE] = {
 327                         .cpo_cache_add = osc_page_cache_add
 328                 }
 329         },
 330         .cpo_clip           = osc_page_clip,
 331         .cpo_cancel         = osc_page_cancel
 332 };
 333
 334 static int osc_make_ready(const struct lu_env *env, void *data, int cmd)
 335 {
 336         struct osc_page *opg  = data;
 337         struct cl_page  *page = cl_page_top(opg->ops_cl.cpl_page);
 338         int result;
 339
 340         LASSERT(cmd == OBD_BRW_WRITE); /* no cached reads */
 341         LINVRNT(osc_page_protected(env, opg, CLM_WRITE, 1));
 342
 343         ENTRY;
 344         result = cl_page_make_ready(env, page, CRT_WRITE);
 345         RETURN(result);
 346 }
 347
 348 static int osc_refresh_count(const struct lu_env *env, void *data, int cmd)
 349 {
 350         struct cl_page   *page;
 351         struct osc_page  *osc = data;
 352         struct cl_object *obj;
 353         struct cl_attr   *attr = &osc_env_info(env)->oti_attr;
 354
 355         int result;
 356         loff_t kms;
 357
 358         LINVRNT(osc_page_protected(env, osc, CLM_READ, 1));
 359
 360         /* readpage queues with _COUNT_STABLE, shouldn't get here. */
 361         LASSERT(!(cmd & OBD_BRW_READ));
 362         LASSERT(osc != NULL);
 363         page = osc->ops_cl.cpl_page;
 364         obj = osc->ops_cl.cpl_obj;
 365
 366         cl_object_attr_lock(obj);
 367         result = cl_object_attr_get(env, obj, attr);
 368         cl_object_attr_unlock(obj);
 369         if (result < 0)
 370                 return result;
 371         kms = attr->cat_kms;
 372         if (cl_offset(obj, page->cp_index) >= kms)
 373                 /* catch race with truncate */
 374                 return 0;
 375         else if (cl_offset(obj, page->cp_index + 1) > kms)
 376                 /* catch sub-page write at end of file */
 377                 return kms % CFS_PAGE_SIZE;
 378         else
 379                 return CFS_PAGE_SIZE;
 380 }
 381
 382 static int osc_completion(const struct lu_env *env,
 383                           void *data, int cmd, struct obdo *oa, int rc)
 384 {
 385         struct osc_page       *opg  = data;
 386         struct osc_async_page *oap  = &opg->ops_oap;
 387         struct cl_page        *page = cl_page_top(opg->ops_cl.cpl_page);
 388         struct osc_object     *obj  = cl2osc(opg->ops_cl.cpl_obj);
 389         enum cl_req_type crt;
 390
 391         LINVRNT(osc_page_protected(env, opg, CLM_READ, 1));
 392
 393         ENTRY;
 394
 395         cmd &= ~OBD_BRW_NOQUOTA;
 396         LASSERT(equi(page->cp_state == CPS_PAGEIN,  cmd == OBD_BRW_READ));
 397         LASSERT(equi(page->cp_state == CPS_PAGEOUT, cmd == OBD_BRW_WRITE));
 398         LASSERT(opg->ops_transfer_pinned);
 399
 400         /*
 401          * page->cp_req can be NULL if io submission failed before
 402          * cl_req was allocated.
 403          */
 404         if (page->cp_req != NULL)
 405                 cl_req_page_done(env, page);
 406         LASSERT(page->cp_req == NULL);
 407
 408         /* As the transfer for this page is being done, clear the flags */
 409         oap->oap_async_flags = 0;
 410
 411         crt = cmd == OBD_BRW_READ ? CRT_READ : CRT_WRITE;
 412         /* Clear opg->ops_transfer_pinned before VM lock is released. */
 413         opg->ops_transfer_pinned = 0;
 414
 415         spin_lock(&obj->oo_seatbelt);
 416         LASSERT(opg->ops_submitter != NULL);
 417         LASSERT(!list_empty(&opg->ops_inflight));
 418         list_del_init(&opg->ops_inflight);
 419         spin_unlock(&obj->oo_seatbelt);
 420
 421         cl_page_completion(env, page, crt, rc);
 422
 423         /* statistic */
 424         if (rc == 0 && oap->oap_brw_flags & OBD_BRW_SRVLOCK) {
 425                 struct lu_device *ld    = opg->ops_cl.cpl_obj->co_lu.lo_dev;
 426                 struct osc_stats *stats = &lu2osc_dev(ld)->od_stats;
 427                 int bytes = opg->ops_to - opg->ops_from;
 428
 429                 if (crt == CRT_READ)
 430                         stats->os_lockless_reads += bytes;
 431                 else
 432                         stats->os_lockless_writes += bytes;
 433         }
 434
 435         /*
 436          * This has to be the last operation with the page, as locks are
 437          * released in cl_page_completion() and nothing except for the
 438          * reference counter protects page from concurrent reclaim.
 439          */
 440         lu_ref_del(&page->cp_reference, "transfer", page);
 441         /*
 442          * As page->cp_obj is pinned by a reference from page->cp_req, it is
 443          * safe to call cl_page_put() without risking object destruction in a
 444          * non-blocking context.
 445          */
 446         cl_page_put(env, page);
 447         RETURN(0);
 448 }
 449
 450 const static struct obd_async_page_ops osc_async_page_ops = {
 451         .ap_make_ready    = osc_make_ready,
 452         .ap_refresh_count = osc_refresh_count,
 453         .ap_completion    = osc_completion
 454 };
 455
 456 struct cl_page *osc_page_init(const struct lu_env *env,
 457                               struct cl_object *obj,
 458                               struct cl_page *page, cfs_page_t *vmpage)
 459 {
 460         struct osc_object *osc = cl2osc(obj);
 461         struct osc_page   *opg;
 462         int result;
 463
 464         OBD_SLAB_ALLOC_PTR(opg, osc_page_kmem);
 465         if (opg != NULL) {
 466                 void *oap = &opg->ops_oap;
 467
 468                 opg->ops_from = 0;
 469                 opg->ops_to   = CFS_PAGE_SIZE;
 470                 opg->ops_ignore_quota = !!cfs_capable(CFS_CAP_SYS_RESOURCE);
 471
 472                 result = osc_prep_async_page(osc_export(osc),
 473                                              NULL, osc->oo_oinfo, vmpage,
 474                                              cl_offset(obj, page->cp_index),
 475                                              &osc_async_page_ops,
 476                                              opg, (void **)&oap, 1, NULL);
 477                 if (result == 0)
 478                         cl_page_slice_add(page, &opg->ops_cl, obj,
 479                                           &osc_page_ops);
 480                 /*
 481                  * Cannot assert osc_page_protected() here as read-ahead
 482                  * creates temporary pages outside of a lock.
 483                  */
 484 #ifdef INVARIANT_CHECK
 485                 opg->ops_temp = !osc_page_protected(env, opg, CLM_READ, 1);
 486 #endif
 487                 CFS_INIT_LIST_HEAD(&opg->ops_inflight);
 488         } else
 489                 result = -ENOMEM;
 490         return ERR_PTR(result);
 491 }
 492
 493 void osc_io_submit_page(const struct lu_env *env,
 494                         struct osc_io *oio, struct osc_page *opg,
 495                         enum cl_req_type crt)
 496 {
 497         struct osc_async_page *oap = &opg->ops_oap;
 498         struct client_obd     *cli = oap->oap_cli;
 499
 500         LINVRNT(osc_page_protected(env, opg,
 501                                    crt == CRT_WRITE ? CLM_WRITE : CLM_READ, 1));
 502
 503         oap->oap_cmd = crt == CRT_WRITE ? OBD_BRW_WRITE : OBD_BRW_READ;
 504         if (opg->ops_ignore_quota)
 505                 oap->oap_cmd |= OBD_BRW_NOQUOTA;
 506
 507         oap->oap_async_flags |= OSC_FLAGS;
 508         if (oap->oap_cmd & OBD_BRW_READ)
 509                 oap->oap_async_flags |= ASYNC_COUNT_STABLE;
 510         else if (!(oap->oap_brw_page.flag & OBD_BRW_FROM_GRANT))
 511                 osc_enter_cache_try(env, cli, oap->oap_loi, oap, 1);
 512
 513         oap->oap_page_off   = opg->ops_from;
 514         oap->oap_count      = opg->ops_to - opg->ops_from;
 515         oap->oap_brw_flags |= oio->oi_lockless ? OBD_BRW_SRVLOCK : 0;
 516
 517         osc_oap_to_pending(oap);
 518         osc_page_transfer_get(opg, "transfer\0imm");
 519         osc_page_transfer_add(env, opg, crt);
 520 }
 521
 522 /** @} osc */